The role of the crystal lattice, temperature and magnetic field for the spin structure formation in the 2D van der Waals magnet Fe5GeTe2 with magnetic ordering up to room temperature is a key open question. Using Lorentz transmission electron microscopy, we experimentally observe topological spin structures up to room temperature in the metastable pre-cooling and stable post-cooling phase of Fe5GeTe2. Over wide temperature and field ranges, skyrmionic magnetic bubbles form without preferred chirality, which is indicative of centrosymmetry. These skyrmions can be observed even in the absence of external fields. To understand the complex magnetic order in Fe5GeTe2, we compare macroscopic magnetometry characterization results with microscopic density functional theory and spin-model calculations. Our results show that even up to room temperature, topological spin structures can be stabilized in centrosymmetric van der Waals magnets.
The study examines which type of religious knowledge acquired in Religious Education in Greek Secondary schools can initiate both personal and collective change in understanding and appreciation of different cultures. It is blended research using participatory action-research with ethnographic elements methodology. The research gathered qualitative and quantitative data through questionnaires, focus groups, journals, and the technique of the “Most Significant Change” from four resources/target groups (students, teachers, parents, researcher). It took place during the 2017–2018 school year in a High and an Upper Schools in which the researcher participated in the school communities as a teacher. Statistical analysis (SPSS), content analysis and thematic analysis of the data show that religious knowledge, developed in Education with the aim of religious literacy, as defined in the context of Greek/European context, can operate on a personal and collective level, in cultivation of respect and underacting of cultural diversity. This is achieved when the religious knowledge is understood as experience and is meaningful when applied to the concepts of understanding, reflection and action. The overall finding is that transformative dynamics of religious knowledge facilitate both minor and major changes in the mindset of young people. Concluding, in Religious Education without sacrificing the religious content of the subject, a high degree of cultural recognition and acceptance of religious diversity can be achieved, and to a certain extent enable a change in attitude towards immigrants and refugees, in other words the ‘other’ as well as in communication and acquaintance between team members, recognition of and a greater degree of acceptance of otherness, and the development of relationships which were non-existent before.
This work summarizes the main characteristics of atmospheric and hydro-physical parameters of the water surface derived from microwave radiometric data. First, current knowledge based on experimental measurements and model calculations of emissivity of the atmosphere and water surface in the microwave spectrum is presented. Emphasis is placed on remote radio-physical methods that have the peculiarity of being related to atmospheric radio-transparency which is one of the main advantages of the microwave radiometric method compared to optical and infrared methods. A detailed presentation is attempted with specific examples of classification of water surface phenomena using software modules included in the system used for the processing of data of radio-physical experiments by the Cosmos-1500 satellite. In addition, the statistical characteristics of the “spotting” of radio-brightness temperatures obtained for the most informative thresholds are analyzed and it is argued that these characteristics for the Pacific areas can also be used to detect abnormal phenomena on the water surface of the Mediterranean Sea. Finally, it is emphasized that the results obtained from this work make it possible to rapidly evaluate various parameters such as temperature, water surface waves, foam formation areas, etc., providing predictions and allocating irregular areas.
Photovoltaic (PV) power production is characterized by high variability due to short-term meteorological effects such as cloud movements. These effects have a significant impact on the incident solar irradiance in PV parks. In order to control PV park performance, researchers have focused on Computer Vision and Deep Learning approaches to perform short-term irradiance forecasting using sky images. Motivated by the task of improving PV park control, the current work introduces the Image Regression Module, which produces irradiance values from sky images using image processing methods and Convolutional Neural Networks (CNNs). With the objective of enhancing the performance of CNN models on the task of irradiance estimation and forecasting, we propose an image processing method based on sun localization. Our findings show that the proposed method can consistently improve the accuracy of irradiance values produced by all the CNN models of our study, reducing the Root Mean Square Error by up to 10.44 W/m2">2 for the MobileNetV2 model. These findings indicate that future applications which utilize CNNs for irradiance forecasting should identify the position of the sun in the image in order to produce more accurate irradiance values. Moreover, the integration of the proposed models on an edge-oriented Field-Programmable Gate Array (FPGA) towards a smart PV park for the real-time control of PV production emphasizes their advantages.
The classical “time-bandwidth” limit for linear time-invariant (LTI) devices in physics and engineering asserts that it is impossible to store broadband propagating waves (large Δω">Δω’s) for long times (large Δt’s). For standing (non-propagating) waves, i.e., vibrations, in particular, this limit takes on a simple form, ΔtΔω=1">ΔtΔω=1, where Δω">Δω is the bandwidth over which localization (energy storage) occurs, and Δt">Δt is the storage time. This is related to a well-known result in dynamics, namely that one can achieve a high Q-factor (narrowband resonance) for low damping, or small Q-factor (broadband resonance) for high damping, but not simultaneously both. It thus remains a fundamental challenge in classical wave physics and vibration engineering to try to find ways to overcome this limit, not least because that would allow for storing broadband waves for long times, or achieving broadband resonance for low damping. Recent theoretical studies have suggested that such a feat might be possible in LTI terminated unidirectional waveguides or LTI topological “rainbow trapping” devices, although an experimental confirmation of either concept is still lacking. In this work, we consider a nonlinear but time-invariant mechanical system and demonstrate experimentally that its time-bandwidth product can exceed the classical time-bandwidth limit, thus achieving values both above and below unity, in an energy-tunable way. Our proposed structure consists of a single-degree-of-freedom nonlinear oscillator, rigidly coupled to a nondispersive waveguide. Upon developing the full theoretical framework for this class of nonlinear systems, we show how one may control the nonlinear flow of energy in the frequency domain, thereby managing to disproportionately decrease (increase) Δt">Δt, the storage time in the resonator, as compared with an increase (decrease) of the system’s bandwidth Δω">Δω. Our results pave the way toward conceiving and harnessing hitherto unattainable broadband and simultaneously low-loss wave-storage devices, both linear and nonlinear, for a host of key applications in wave physics and engineering.
Topological features, in particular distinct band intersections known as nodal rings, usually requiring three-dimensional structures, have now been demonstrated experimentally in an elegantly simple one-dimensional photonic crystal.
After 1981, with Greece’s accession into the European Economic Community (EEC), as today’s European Union (EU) was called at the time, the Greek diasporic phenomenon was transformed and the Greek theatrical mobility was mainly related to the recruitment of Greek officials to the EU institutions and organizations. For the next 40 years, the Greek Diasporic Community Theater (DCT) of Brussels has become a participatory field of integration and Greek troupes have begun to proliferate, influenced by the demographic, ideological, and socio-structural changes that have taken place both in Greece and Belgium in recent decades. The present paper studies and presents the causes of the artistic resilience of the Greek Diasporic Community Theater (DCT) in Brussels. The case of the Greek DCT in Brussels is such a unique case of DCT, which operates continuously and systematically from the early 1980s until today, flourishing and presenting unprecedented signs of resilience.
In volleyball, the performance in the passing affects the setter’s strategy and the effectiveness of the attack after the reception or defense. This study aims to assess the spatial and temporal characteristics of the setting choices made by junior female volleyball setters and their performance concerning the origin of the ball and the game complex. The sample for this analysis consists of 3728 setting actions (Complex I = 1.616, Complex II = 1.212). A three-member group of experienced coaches assessed the setting zones’ choices as well as the setting tempo and the performance of junior female setters from 20 volleyball games of teams competing in the final phase of the Greek Junior Championship. The variables under consideration were complex of the game (C1 & CII), origin of the ball (left/middle/right lane for the vertical and front/centre/back lane for the horizontal axis of the court), setting zone (six zones of the court), setting tempo (1st, 2nd & 3rd tempo) and setting performance in a five-level ordinal scale. Inter-rater and intra-rater reliability coefficients were estimated using Cohen’s kappa coefficient with acceptable values. The test of independence for the categorical variables was carried out using the chisquare test. Following the overall independence test, the difference in proportions among all levels of variables was tested. Results showed that junior female setters regardless of the complex and the origin of the ball choose zone 4 in a 3rd tempo, performed in a moderate and good setting. However, the origin of the ball was an important variable for the subsequent setting. The most preferable route of the ball was from a pass in the left lane of the court to an attack in zone 4 regardless of the game complex. Additionally, setters when receiving the ball from the left and middle lane of the court prefer more often zone 3 in 1st tempo, during CI than CII. The results of the study will give useful directions to the coaches of the specific age category regarding the creation of appropriate training programs for the individual improvement of the setters and teams.
Eight years after the first detection of high-energy astrophysical neutrinos by IceCube, we are still almost clueless as regards to their origin, although the case for blazars being neutrino sources is getting stronger. After the first significant association at the $3\!-\!3.5\, \sigma$ level in time and space with IceCube neutrinos, i.e. the blazar TXS 0506+056 at z = 0.3365, some of us have in fact selected a unique sample of 47 blazars, out of which ~16 could be associated with individual neutrino track events detected by IceCube. Building upon our recent spectroscopy work on these objects, here we characterize them to determine their real nature and check if they are different from the rest of the blazar population. For the first time we also present a systematic study of the frequency of masquerading BL Lacs, i.e. flat-spectrum radio quasars with their broad lines swamped by non-thermal jet emission, in a γ-ray- and IceCube-selected sample, finding a fraction >24 per cent and possibly as high as 80 per cent. In terms of their broad-band properties, our sources appear to be indistinguishable from the rest of the blazar population. We also discuss two theoretical scenarios for neutrino emission, one in which neutrinos are produced in interactions of protons with jet photons and one in which the target photons are from the broad-line region. Both scenarios can equally account for the neutrino-blazar correlation observed by some of us. Future observations with neutrino telescopes and X-ray satellites will test them out.
The exchange rate dynamics affect national economies because fluctuations in currency prices distort their economic activity. To maintain an optimal exchange rate policy, these dynamics are crucial for countries with a trade economy. Due to the difficulty in predicting the participants behavior in some complex economic systems, which might throw the system into chaos, a novel stochastic exchange rate dynamics (SERD) model is introduced and investigated in this paper. Furthermore, a neural network approach is proposed and examined as a control chaos method to address the problem of stabilizing SERD through central bank interventions. Derived from power activation feed-forward neuronets, a 2-input weights-and-structure-determination-based neuronet (2I-WASDBN) model for controlling chaos in SERD under central bank intervention is presented in this paper. Six simulation experiments on stabilizing the chaotic behavior of the SERD model show that the 2I-WASDBN model outperforms other well-performing neural network models and that it is more effective than traditional methods for controlling chaos. By examining the volume of necessary intervention predicted by the 2I-WASDBN model, central banks can better comprehend exchange rate fluctuations and, in conjunction with their monetary policies, can make more precise decisions regarding the strategy of their interventions.
This paper examines the positions of the Greek-speaking Orthodox Churches concern- ing Russia’s ongoing war against Ukraine. Apart from being informative, the paper raises the theological question about whether the Churches’ various stances follow Christ’s commandment to spread his teaching to the world and to what degree they are compatible with relevant New Testament texts. After navigating through and commenting on the relevant statements of the Patriarchates of Constantinople, Al- exandria, and Jerusalem, the Autocephalous Churches of Cyprus and Greece, and the Holy Community of Mount Athos, two New Testament texts that represent different approaches to political power, namely Rom 13:1–7 and John’s Revelation, are briefly examined. The paper establishes that the positions of the Greek-speaking Churches vary between general anti-war statements and concrete condemnations of the Russian invasion and its direct or indirect support by the Russian Orthodox hi- erarchy. However, nationalism, as well as church-political opportunism, seem to be more or less inherent phenomena in all contemporary national Orthodox Churches. Hence, finally, it is up to the faithful, not just to Church hierarchies, to discern evil and speak out against injustice.
Christa Wolf hat Literatur immer als ideologiekritisches Medium betrachtet, um Erinnerungskultur und Erinnerungsmythen zu hinterfragen. Dazu muss man mit den Gespenstern sprechen. Dies geschieht durch die Schaffung von Texten, die mit den Grenzen der Sprache experimentieren. Die vorliegende Studie geht davon aus, dass der Roman Leibhaftig der ehrlichste und zugleich erfolgreichste Versuch der Autorin in dieser Richtung ist, ein erzählerisches Experiment, das darauf abzielt, "die Grenzen des Sagbaren zu überschreiten". Die Erzählung ist ein multiperspektivisches polyvokales literarisches Netzwerk. Spielerisch experimentiert der Autor in zwei Richtungen: mit verschiedenen zeitlichen Perspektiven und mit verschiedenen Formen von Erzähler und Erzählperspektive. Die Struktur der Erzählung ist multitemporal. Die Ebene einer extradiegetisch-homodiegetischen Erzählinstanz in der Gegenwart wird mit Erinnerungen aus rund sechzig Jahren Vergangenheit sowie aus der gesamten Menschheitsgeschichte verwoben. Außerdem wird die Geschichte in zwei Erzählstimmen erzählt, sowohl in der ersten als auch in der dritten Person, wobei der Wechsel oft mitten im Satz stattfindet. Das Ergebnis ist ein offener Text, der sich nicht scheut, die Wunde offen zu lassen, mit den eigenen wie mit den kollektiven Phantomen abzurechnen.
Context. Black-hole X-ray binaries (BHXRBs) in the hard and hard-intermediate spectral (and temporal) states exhibit in their power spectra characteristic frequencies called type-C quasi-periodic oscillations (QPOs). Various models that can explain them with various degrees of success have been proposed, but a definitive answer is still missing. Aims: The hot Comptonizing corona interacting with the cold accretion disk, both of which are central in understanding BHXRBs, is essentially a dynamical system. Our aim is to investigate if the radiative coupling between the two components can produce QPOs. Methods: We write and solve the time-dependent equations that describe energy conservation in the system corona - accretion disk. We examine both constant and variable mass accretion rates. By necessity, in this first investigation we use a simple model, but it contains all the essential ingredients. Results: For a constant mass accretion rate and certain justifiable conditions, the dynamic corona - disk system exhibits oscillations, which die out after a few cycles. The characteristic frequencies of these oscillations are similar to the ones observed in the power spectra of BHXRBs. For most parameters, the natural frequencies persist even in the case of variable accretion rates. Conclusions: We argue that type-C QPOs in BHXRBs could, in principle, arise from the interaction of the hot Comptonizing corona with the much colder accretion disk. If this picture is correct, it has immediate implications for other systems that contain the above constituents, such as active galactic nuclei.
AIMS: Depression and atherosclerotic cardiovascular disease (ASCVD) are commonly clustered in affected patients. Endothelial dysfunction is an early marker of ASCVD while also reported in patients with depression. Emerging evidence suggests that selective serotonin receptor inhibitors (SSRIs) may improve endothelial function. However, clinical studies assessing flow-mediated dilation (FMD), the gold-standard method to evaluate conduit artery endothelial function, in response to SSRIs treatment included limited number of patients and did not provide consistent results. In the present study we aim to evaluate the effect of SSRIs treatment on endothelial function assessed by longitudinal changes in FMD. METHODS AND RESULTS: We performed a systematic review to retrieve and subsequently meta-analyze eligible studies in patients with depression who received SSRIs and had available measurements of FMD change before and after treatment. In 5 studies and 323 individuals in total, SSRIs were associated with increased FMD at the end of follow-up compared to baseline measurement (pooled mean change 1.97 %, 95 % CI 0.17, 3.77, P = 0.032, I(2) = 87.4 %). These results did not substantially change when analysis was restricted to patients with history of atherosclerotic cardiovascular disease (ASCVD). Similarly, FMD changes were higher in individuals receiving SSRIs compared to not-treated subjects (pooled mean difference 2.5 %. 95 % CI 0.7, 4.2, P < 0.001, I(2) = 82.7 %). LIMITATIONS: Substantial heterogeneity regarding with respect to follow-up duration, demographics, and SSRIs agents. CONCLUSION: SSRIs significantly improve FMD, the gold-standard marker of endothelial function. Further investigation is warranted for the role of FMD as a possible therapeutic biomarker in patients with depression and established or subclinical ASCVD. PROSPERO REGISTRATION: CRD42021252241.
The combination of two imaging modalities in a single agent has received increasing attention during the last few years, since its synergistic action guarantees both accurate and timely diagnosis. For this reason, dual-modality contrast agents (DMCAs), such as radiolabeled iron oxide (namely Fe3O4) nanoparticles, constitute a powerful tool in diagnostic applications. In this respect, here we focus on the synthesis of a potential single photon emission computed tomography/magnetic resonance imaging (SPECT/MRI) DMCA, which consists of Fe3O4 nanoparticles, surface functionalized with 2,3-dicarboxypropane-1,1-diphosphonic acid (DPD) and radiolabeled with Tc-99m, [Tc-99m]Tc-DPD-Fe3O4. The in vitro stability results showed that this DMCA is highly stable after 24 h of incubation in phosphate buffer saline (similar to 92.3% intact), while it is adequately stable after 24 h of incubation with human serum (similar to 67.3% intact). Subsequently, [Tc-99m]Tc-DPD-Fe3O4 DMCA was evaluated in vivo in mice models through standard biodistribution studies, MR imaging and gamma-camera imaging. All techniques provided consistent results, clearly evidencing noticeable liver uptake. Our work documents that [Tc-99m]Tc-DPD-Fe3O4 has all the necessary characteristics to be a potential DMCA.
ABSTRACT: The aim of the presentation is to discuss the findings of a series of research projects that we have been carried out with various groups of students in the University of Athens and concern the teaching of biology by means of evolution through natural selection (THES). In the article it is discussed the conclusions after teaching a biology course based on evolution as the unifying theory, while at the same time more general issues are raised: Is it, for example, a realistic goal to teach biology by means of this kind of teaching? Secondly, what is the usefulness of such a perspective. Which was studied by quantitative and qualitative studies on the conceptual ecology (CE) of the evolution of Greek students. The latter showed the value of this kind of approach in the acceptance and understanding of the THES, as part of students’ CI. Thirdly, ccomparative studies with beginners and advanced students in terms of evolution education showed, that, merely teaching evolution within a course, even if the latter is based on the THES, it is not enough to make someone in-depth connoisseur. It seems that to be acquainted with it to more depth the learners need to go through two stages: in the first, they may move from the stage of owing Aristotelian views of the issue, i.e., from typology, to the early “Darwinian” ones. And they need to go through a second one, where via, in-depth educational training, they might move to the next, namely, the population view of thinking.
Glucocorticoids are important for proper organ maturation1. Increased exposure to these hormones during pregnancy, as a result of commonly prescribed synthetic glucocorticoids such as dexamethasone in preterm births2, has been associated with lasting effects on the offspring, including on neurodevelopment and neuropsychiatric disease risk3. While the consequences of glucocorticoid excess in term and especially adult brain have been extensively studied, mainly in rodents4, studies on their effects during early human cortical development are absent. Here we use human cerebral organoids and mice to study cell-type specific effects of glucocorticoids on neurogenic processes. We show that glucocorticoid administration during neurogenesis alters the cellular architecture of the developing cortex by increasing a specific type of gyrencephalic species-enriched basal progenitors that co-express PAX6 and EOMES. This effect is mediated via the glucocorticoid-responsive transcription factor ZBTB16 as shown with overexpression, genetic knock-down and reporter assays experiments in organoids and embryonic mouse models and leads to increased production of deep-layer neurons. A phenome-wide mendelian randomization analysis of a genetic intronic enhancer variant that moderates glucocorticoid-induced ZBTB16 levels, as shown with enhancer assays and enhancer-editing in organoids, reveals potential causal relationships with increased educational attainment as well as neuroimaging phenotypes in adults. In this study we provide a cellular and molecular pathway for the effects of glucocorticoids on human neurogenesis that potentially explains postnatal phenotypes and may be used to refine treatment guidelines.
Cyclobutadienyl complexes of the f-elements are a relatively new yet poorly understood class of sandwich and half-sandwich organometallic compounds. We now describe cyclobutadienyl transfer reactions of the magnesium reagent [(η4-Cb'''')Mg(THF)3] (1), where Cb'''' is tetrakis(trimethylsilyl)cyclobutadienyl, toward thorium(IV) and uranium(IV) tetrachlorides. The 1:1 stoichiometric reactions between 1 and AnCl4proceed with intact transfer of Cb'''' to give the half-sandwich complexes [(η4-Cb'''')AnCl(μ-Cl)3Mg(THF)3] (An = Th, 2; An = U, 3). Using a 2:1 reaction stoichiometry produces [Mg2Cl3(THF)6][(η4-Cb'''')An(η3-C4H(SiMe3)3-κ-(CH2SiMe2)(Cl)] (An = Th, [Mg2Cl3(THF)6][4]; An = U [Mg2Cl3(THF)6][5]), in which one Cb'''' ligand has undergone cyclometalation of a trimethylsilyl group, resulting in the formation of an An-C σ-bond, protonation of the four-membered ring, and an η3-allylic interaction with the actinide. Complex solution-phase dynamics are observed with multinuclear nuclear magnetic resonance spectroscopy for both sandwich complexes. A computational analysis of the reaction mechanism leading to the formation of 4 and 5 indicates that the cyclobutadienyl ligands undergo C-H activation across the actinide center. copy; 2022 American Chemical Society.
Context. The Magellanic Clouds host a large population of high-mass X-ray binary (HMXB) systems, and although the Large Magellanic Cloud (LMC) is an order of magnitude more massive than the Small Magellanic Cloud, there are significantly fewer known HMXBs in the former. Aims: We conducted a search for new HMXBs in XMM-Newton observations that were performed with the aim of investigating supernova remnant candidates in the supergiant shells LMC5 and LMC7. The three observed fields are located in regions that have not been widely explored in the X-ray band. Methods: We analysed the XMM-Newton data to look for sources with hard X-ray spectrum and their counterparts with optical colours and brightness values that are typical of HMXBs. Results: We report the discovery of three new Be/X-ray binaries, two of them showing pulsations in their X-ray flux. With a luminosity of 6.5 × 1034 erg s−1, we see that XMMU J045315.1−693242 in LMC7 was relatively X-ray faint. The long-term OGLE I-band light curve of the V = 15.5 mag counterpart suggests a 49.6 day or 24.8 day orbital period for the binary system. Then, XMMU J045736.9−692727, which is also located in LMC7, was brighter, with a luminosity of 5.6 × 1035 erg s−1 and hard spectrum with a power-law photon index of 0.63. The X-ray flux revealed clear pulsations with a period of 317.7 s. We obtained optical high resolution spectra from the V = 14.2 mag counterpart using the SALT-HRS spectrograph. Hα and Hβ were observed in emission with complex line profiles and equivalent widths of −8.0 Å and −1.3 Å, respectively. The I-band light curve obtained from OGLE shows a series of four strong outbursts followed by a sudden drop in brightness by more than 1 mag within 73-165 days and a recovery to the level from before the outbursts. RX J0524.2−6620, previously classified as X-ray binary candidate, is located at the eastern part of LMC5. We report the discovery of 360.7 s pulsations. During the XMM-Newton observation the luminosity was at ∼4 × 1035 erg s−1 and the source showed a hard spectrum with a power-law photon index of 0.78. The Hα emission line profile obtained from SALT-HRS is characterised by two broad peaks with a separation corresponding to ∼178 km s−1, along with an equivalent width of −4.2 Å. The long-term OGLE I-band light curve of the V = 14.9 mag counterpart reveals a quasi-periodic flaring activity while the colour evolution during the flares follows a hysteresis loop with redder colour during the rise. Based on the modelling the Hα line profiles measured from XMMU J045736.9−692727 and RX J0524.2−6620, we derived constraints on the size of the Be disks. Conclusions: Our discovery of two pulsars among three new Be/X-ray binaries increases the number of known HMXB pulsars in the LMC to 25.
Heterostructured WO3/TiO2 photonic crystal films in the form of three-dimensional macroporous inverse opals were developed by single-step, three-phase co-assembly of colloidal templates with water soluble precursors enabling simultaneous growth of both metal oxides into a firmly interconnected periodic pore framework whose skeletal walls consisted of uniformly distributed nanoscale type II WO3-TiO2 heterojunctions. A marked size- and composition-dependence of the binary WO3/TiO2 inverse opal properties was evidenced by controlling the W/Ti molar ratio and macropore diameter that allowed Fermi level and photonic band gap engineering according to optical and photoelectron spectroscopies supplemented by electrochemical measurements. Compositional tuning along with the reduction of WO3 nanocrystallite size and the concomitant W5+ defect growth with increasing TiO2 phase content were explored for the optimization of photocurrent generation by WO3/TiO2 inverse opal photoanodes combining reduced charge carrier recombination and optimal slow light trapping. One step co-assembly of mixed metal oxides is concluded as a promising route for the development of heterostructured inverse opal networks with tailored electronic properties and improved solar light harvesting for photo-induced applications.
It is widely acclaimed that the Markowitz mean–variance portfolio selection is a very important investment strategy. One approach to solving the static mean–variance portfolio selection (MVPS) problem is based on the usage of quadratic programming (QP) methods. In this article, we define and study the time-varying mean–variance portfolio selection (TV-MVPS) problem both in the cases of a fixed target portfolio’s expected return and for all possible portfolio’s expected returns as a time-varying quadratic programming (TVQP) problem. The TV-MVPS also comprises the properties of a moving average. These properties make the TV-MVPS an even greater analysis tool suitable to evaluate investments and identify trading opportunities across a continuous-time period. Using an originally developed linear-variational-inequality primal–dual neural network (LVI-PDNN), we also provide an online solution to the static QP problem. To the best of our knowledge, this is an innovative approach that incorporates robust neural network techniques to provide an online, thus more realistic, solution to the TV-MVPS problem. In this way, we present an online solution to a time-varying financial problem while eliminating static method limitations. It has been shown that when applied simultaneously to TVQP problems subject to equality, inequality and boundary constraints, the LVI-PDNN approaches the theoretical solution. Our approach is also verified by numerical experiments and computer simulations as an excellent alternative to conventional MATLAB methods.
Measuring a pulsar's rotational evolution is crucial to understanding the nature of the pulsar. Here, we provide updated timing models for the rotational evolution of six pulsars, five of which are rotation phase-connected using primarily NICER X-ray data. For the newly discovered fast energetic young pulsar, PSR J0058-7218, we increase the baseline of its timing model from 1.4 days to 8 months and not only measure more precisely its spin-down rate $\dot{\nu }=(-6.2324\pm 0.0001)\times {10}^{-11}\,\mathrm{Hz}\,{{\rm{s}}}^{-1}$ but also for the first time the second time derivative of its spin rate $\ddot{\nu }=(4.2\pm 0.2)\times {10}^{-21}\,\mathrm{Hz}\,{{\rm{s}}}^{-2}$ . For the fastest and most energetic young pulsar, PSR J0537-6910 (with a 16 ms spin period), we detect four more glitches, for a total of 15 glitches over 4.5 yr of NICER monitoring, and show that its spin-down behavior continues to set this pulsar apart from all others, including a long-term braking index n = -1.234 ± 0.009 and interglitch braking indices that asymptote to ≲7 for long times after a glitch. For PSR J1101-6101, we measure a much more accurate spin-down rate that agrees with a previous value measured without phase connection. For PSR J1412+7922 (also known as Calvera), we extend the baseline of its timing model from our previous 1 yr model to 4.4 yr, and for PSR J1849-0001, we extend the baseline from 1.5 to 4.7 yr. We also present a long-term timing model of the energetic pulsar PSR J1813-1749, by fitting previous radio and X-ray spin frequencies from 2009-2019 and new ones measured here using 2018 NuSTAR and 2021 Chandra data.
Τhe incumbent technology for bringing light to the nanoscale, the near-field scanning optical microscope, has notoriously small throughput efficiencies of the order of 104 −105, or less. We report on a broadband, topological, unidirectionally guiding structure, not requiring adiabatic tapering and, in principle, enabling near-perfect (∼100%) optical transmission through an unstructured single arbitrarily subdiffraction slit at its end. Specifically, for a slit width of just λeff/72 (λ0/138) the attained normalized transmission coefficient reaches a value of 1.52, while for a unidirectional-only (nontopological) device the normalized transmission through a λeff/21 (∼λ0/107) slit reaches 1.14; both limited only by inherent material losses, and with zero reflection from the slit. The associated, under ideal (ultralow-loss) conditions, near-perfect optical extraordinary transmission has implications, among diverse areas in wave physics and engineering, for high-efficiency, maximum-throughput nanoscopes and heat-assisted magnetic recording devices.
One of the most often used approaches for approximating various matrix equation problems is the hyperpower family of iterative methods with arbitrary convergence order, whereas the zeroing neural network (ZNN) is a type of neural dynamics intended for handling time-varying problems. A family of ZNN models that correlate with the hyperpower iterative methods is defined on the basis of the analogy that was discovered. These models, known as higher-order ZNN models (HOZNN), can be used to find real symmetric solutions of time-varying algebraic Riccati equations. Furthermore, a noise-handling HOZNN (NHOZNN) class of dynamical systems is introduced. The traditional ZNN and HOZNN dynamic flows are compared theoretically and numerically.
An increasing number of solute transporters have been shown to function with the so-called sliding-elevator mechanism. Despite structural and functional differences, all elevator-type transporters use a common mechanism of substrate translocation via reversible movements of a mobile core domain (the elevator) hosting the substrate binding site along a rigid scaffold domain stably anchored in the plasma membrane via homodimerization. One of the best-studied elevator transporters is the UapA uric acid-xanthine/H+ symporter of the filamentous fungus Aspergillus nidulans. Here, we present a genetic analysis for deciphering the role of transmembrane segments (TMS) 5 and 12 in UapA transport function. We show that specific residues in both TMS5 and TMS12 control, negatively or positively, the dynamics of transport, but also substrate binding affinity and specificity. More specifically, mutations in TMS5 can lead not only to increased rate of transport but also to an inactive transporter due to high-affinity substrate-trapping, whereas mutations in TMS12 lead to apparently uncontrolled sliding and broadened specificity, leading in specific cases to UapA-mediated purine toxicity. Our findings shed new light on how elevator transporters function and how this knowledge can be applied to genetically modify their transport characteristics.
The regular reappearance of coronavirus (CoV) outbreaks over the past 20 years has caused significant health consequences and financial burdens worldwide. The most recent and still ongoing novel CoV pandemic, caused by Severe Acute Respiratory Syndrome coronavirus 2 (SARS-CoV-2) has brought a range of devastating consequences. Due to the exceptionally fast development of vaccines, the mortality rate of the virus has been curbed to a significant extent. However, the limitations of vaccination efficiency and applicability, coupled with the still high infection rate, emphasise the urgent need for discovering safe and effective antivirals against SARS-CoV-2 by suppressing its replication or attenuating its virulence. Non-structural protein 1 (nsp1), a unique viral and conserved leader protein, is a crucial virulence factor for causing host mRNA degradation, suppressing interferon (IFN) expression and host antiviral signalling pathways. In view of the essential role of nsp1 in the CoV life cycle, it is regarded as an exploitable target for antiviral drug discovery. Here, we report a variety of fragment hits against the N-terminal domain of SARS-CoV-2 nsp1 identified by fragment-based screening via X-ray crystallography. We also determined the structure of nsp1 at atomic resolution (0.99 A). Binding affinities of hits against nsp1 and potential stabilisation were determined by orthogonal biophysical assays such as microscale thermophoresis and thermal shift assays. We identified two ligand-binding sites on nsp1, one deep and one shallow pocket, which are not conserved between the three medically relevant SARS, SARS-CoV-2 and MERS coronaviruses. Our study provides an excellent starting point for the development of more potent nsp1-targeting inhibitors and functional studies on SARS-CoV-2 nsp1.
Blazars are a class of active galactic nuclei that host relativistic jets oriented close to the observer's line of sight. Blazars have very complex variability properties. Flares, namely flux variations around the mean value with a well-defined shape and duration, are one of the identifying properties of the blazar phenomenon. Blazars are known to exhibit multiwavelength flares, but also "orphan" flares, namely flux changes that appear only in a specific energy range. Various models, sometimes at odds with each other, have been proposed to explain specific flares even for a single source, and cannot be synthesized into a coherent picture. In this paper, we propose a unified model for explaining orphan and multiwavelength flares from blazars in a common framework. We assume that the blazar emission during a flare consists of two components: (i) a quasistable component that arises from the superposition of numerous but comparatively weak dissipation zones along the jet, forming the background (low-state) emission of the blazar, and (ii) a transient component, which is responsible for the sudden enhancement of the blazar flux, forming at a random distance along the jet by a strong energy dissipation event. Whether a multiwavelength or orphan flare is emitted depends on the distance from the base of the jet where the dissipation occurs. Generally speaking, if the dissipation occurs at a small/large distance from the supermassive black hole, the inverse Compton/synchrotron radiation dominates and an orphan γ -ray/optical flare tends to appear. On the other hand, we may expect a multiwavelength flare if the dissipation occurs at an intermediate distance. We show that the model can successfully describe the spectral energy distribution of different flares from the flat spectrum radio quasar 3C 279 and the BL Lacertae object PKS 2155-304.
In the context of infinite-horizon optimal control problems, the algebraic Riccati equations (ARE) arise when the stability of linear time-varying (LTV) systems is investigated. Using the zeroing neural network (ZNN) approach to solve the time-varying eigendecomposition-based ARE (TVE-ARE) problem, the ZNN model (ZNNTVE-ARE) for solving the TVE-ARE problem is introduced as a result of this research. Since the eigendecomposition approach is employed, the ZNNTVE-ARE model is designed to produce only the unique nonnegative definite solution of the time-varying ARE (TV-ARE) problem. It is worth mentioning that this model follows the principles of the ZNN method, which converges exponentially with time to a theoretical time-varying solution. The ZNNTVE-ARE model can also produce the eigenvector solution of the continuous-time Lyapunov equation (CLE) since the Lyapunov equation is a particular case of ARE. Moreover, this paper introduces a hybrid ZNN model for stabilizing LTV systems in which the ZNNTVE-ARE model is employed to solve the continuous-time ARE (CARE) related to the optimal control law. Experiments show that the ZNNTVE-ARE and HFTZNN-LTVSS models are both effective, and that the HFTZNN-LTVSS model always provides slightly better asymptotic stability than the models from which it is derived.
Coastal areas constitute a very dynamic environment, balancing between numerous natural and anthropogenic processes liable to sometimes hazardous geomorphic phenomena. Especially in tectonically active coastal regions and areas of high economic value, slope failures can have significant impacts and therefore need careful and detailed examination. This work uses Unmanned Aerial System (UAS)-aided photogrammetry and Terrestrial Laser Scanning (TLS) in tectonically active segments of the coastal zone of the Ionian Islands in Greece, to explore how their capabilities can help to improve our understanding of the structural integrity of the slopes. Results show that the two approaches are able to extract large numbers of discontinuity facets, in a more practical, rapid and safe way than conventional methods of rock slope stability analysis extending to unreachable yet important parts of the slope. Through this holistic record of the structural condition of the slope the two applications allow the identification of segments that are more prone to instability and failure. In this way, they improve our understanding of the prioritization of interventions aiming to enhance the prevention of slope failures, mitigating the associated risk and improving local development in these high-value locations.
Coastal areas constitute a very dynamic environment, balancing between numerous natural and anthropogenic processes liable to sometimes hazardous geomorphic phenomena. Especially in tectonically active coastal regions and areas of high economic value, slope failures can have significant impacts and therefore need careful and detailed examination. This work uses Unmanned Aerial System (UAS)-aided photogrammetry and Terrestrial Laser Scanning (TLS) in tectonically active segments of the coastal zone of the Ionian Islands in Greece, to explore how their capabilities can help to improve our understanding of the structural integrity of the slopes. Results show that the two approaches are able to extract large numbers of discontinuity facets, in a more practical, rapid and safe way than conventional methods of rock slope stability analysis extending to unreachable yet important parts of the slope. Through this holistic record of the structural condition of the slope the two applications allow the identification of segments that are more prone to instability and failure. In this way, they improve our understanding of the prioritization of interventions aiming to enhance the prevention of slope failures, mitigating the associated risk and improving local development in these high-value locations.
In volleyball outside hitters have wide participation in the offensive game. This study aims to analyze the variables that predict attack effectiveness in top-level volleyball depending on gender. ...
PURPOSE: To evaluate the association between serum vitamin B12/folate and retinal vein occlusion (RVO). METHODS: A comprehensive search of the PubMed database was performed, which identified 271 abstracts to be screened. Ten studies met our inclusion criteria and a meta-analysis of these comparative case-control studies was performed on the mean +/- standard deviation serum vitamin B12 and folate levels, without language restrictions. Nine studies with 720 patients with RVO and 613 controls were included in the meta-analysis for vitamin B12, and 10 studies with 784 patients with RVO and 677 controls in the meta-analysis for folate. RESULTS: There was no statistically significant difference between patients with RVO and controls in serum vitamin B12 levels (mean difference: - 40.25 pg/mL, p = 0.28), either central RVO (mean difference: - 18.24 pg/mL, p = 0.71) or branch RVO (mean difference: - 23.56 pg/mL, p = 0.48). On the contrary, the plasma folate level was significantly lower in RVO patients than in controls (mean difference: - 1.34 ng/mL, p = 0.001), as well as in patients with CRVO compared to controls (mean difference: - 1.48 ng/mL, p = 0.006), but not in BRVO patients (mean difference: - 0.72 ng/mL, p = 0.11). CONCLUSIONS: RVO is associated with low serum folate levels, but not with serum vitamin B12 levels
Global exposure of children to sexual abuse is widespread. Disclosure may be extremely upsetting for both families and medical professionals. This review provides medical practitioners with practical tips for a stepwise approach of the child who discloses sexual abuse. Having secured a private examination room, the physician should approach the child and caregivers separately to determine the level of concern for abuse and the urgency of the situation. The medical evaluation is based on the information gathered, including a complete physical examination, inspection of the genitalia, collection of forensic evidence, and testing for sexually transmitted diseases. On a case-by-case basis, the need for surgical intervention, prophylactic treatment, and immunization is discussed. Finally, important questions for the medical team to address are outlined with the goal of supporting the child and his/her family and ultimately stopping the abuse.
Aims: We conducted a spectral and temporal analysis of X-ray data from the Be X-ray binary pulsar SXP 15.6 located in the Small Magellanic Cloud based on NuSTAR, NICER, and Swift observations during the 2021 outburst. Methods: We present the broadband X-ray spectra of the system based on simultaneous NuSTAR and NICER observations for the first time. Moreover, we used monitoring data to study the spectral and temporal properties of the system during the outburst. Results: Comparison of the evolution of the 2021 outburst with archival data reveals a consistent pattern of variability, with multiple peaks occurring at time intervals similar to the orbital period of the system (∼36 d). Our spectral analysis indicates that most of the energy is released at high energies above 10 keV, while we found no cyclotron absorption line in the spectrum. Analysing of the spectral evolution during the outburst, we find that the spectrum is softer when brighter, which in turn reveals that the system is probably in the super-critical regime in which the accretion column is formed. This places an upper limit on the magnetic field of the system of about 7 × 1011 G. The spin-evolution of the neutron star (NS) during the outburst is consistent with an NS with a low magnetic field (∼5 × 1011 G), while there is evident orbital modulation that we modelled, and we derived the orbital parameters. We found the orbit to have a moderate eccentricity of ∼0.3. Our estimates of the magnetic field are consistent with the lack of an electron cyclotron resonance scattering feature in the broadband X-ray spectrum.
This research introduces three novel zeroing neural network (ZNN) models for addressing the time-varying Yang–Baxter-like matrix equation (TV-YBLME) with arbitrary (regular or singular) real time-varying (TV) input matrices in continuous time. One ZNN dynamic utilizes error matrices directly arising from the equation involved in the TV-YBLME. Moreover, two ZNN models are proposed using basic properties of the YBLME, such as the splitting of the YBLME and sufficient conditions for a matrix to solve the YBLME. The Tikhonov regularization principle enables addressing the TV-YBLME with an arbitrary input real TV matrix. Numerical experiments, including nonsingular and singular TV input matrices, show that the suggested models deal effectively with the TV-YBLME.
Many researchers have investigated the time-varying (TV) matrix pseudoinverse problem in recent years, for its importance in addressing TV problems in science and engineering. In this paper, the problem of calculating the inverse or pseudoinverse of an arbitrary TV real matrix is considered and addressed using the singular value decomposition (SVD) and the zeroing neural network (ZNN) approaches. Since SVD is frequently used to compute the inverse or pseudoinverse of a matrix, this research proposes a new ZNN model based on the SVD method as well as the technique of Tikhonov regularization, for solving the problem in continuous time. Numerical experiments, involving the pseudoinversion of square, rectangular, singular, and nonsingular input matrices, indicate that the proposed models are effective for solving the problem of the inversion or pseudoinversion of time varying matrices.
During the 2021-2022 school year, the innovative lesson “Skills Labs” was introduced in the Greek school curriculum with the aim to enhance students’ everyday skills, life skills as well as technology and science skills. The principal aim of this research was to examine teachers’ familiarity on the suggested teaching methods which are the prerequisites for the effective implementation of the “Skills Labs”. Participants were 110 teachers of various specialties who completed a questionnaire assessing their experiences and views regarding the “Skills Labs”. Results showed that teachers are familiar with alternative teaching methods such as the Experiential, Cooperative and Personalized methods. Most of the teachers, though, did not take full advantage of these teaching methods in class. This may reflect the fact that they lack adequate in-service training as well as teaching experience. Moreover, teachers’ teaching experience and level of education were significantly related to their teaching methods. It was also found that the effective implementation of the “Skills Labs”, according to teachers’ views, depends on various factors, such as students’ readiness, adequate teaching time, and classroom infrastructure. Finally, based on the results of this study, suggestions for educational policy are made.
Στόχος της παρούσας εργασίας είναι, μέσω της ανάλυσης βιογραφιών ζωής εξαρτημένων ατόμων, να διερευνηθεί η σχέση ανάμεσα στα τραυματικά γεγονότα ζωής και τα συναισθήματα που τα συνοδεύουν με την έναρξη της χρήσης ουσιών και την πρόωρη εγκατάλειψη του σχολείου. Η ανάλυση βιογραφιών ζωής ατόμων που εισάγονται σε προγράμματα απεξάρτησης του ΚΕΘΕΑ αξιοποιείται προκειμένου να διερευνηθούν οι ερμηνείες και το νόημα που τα ίδια αποδίδουν στις εμπειρίες τους αλλά και να γίνει κατανοητός ο τρόπος κατασκευής ιστοριών ζωής από τη σκοπιά του παρόντος. Μέσα από την ανάλυση δέκα βιογραφιών ζωής τις οποίες καλούνται να συγγράψουν όλα τα άτομα που συμμετέχουν σε θεραπευτική κοινότητα απεξάρτησης, αναζητά την ερμηνεία που τα ίδια τα άτομα δίνουν για τη σχέση ανάμεσα στα τραυματικά γεγονότα ζωής και στην έναρξη της χρήσης ουσιών, τη σχολική αποτυχία και την πρόωρη διακοπή του σχολείου. Με τη μέθοδο της ανάλυσης περιεχομένου προκύπτει ότι σε κάθε αναπτυξιακή φάση αναδύονται συγκεκριμένοι παράγοντες που συνδυάζονται με την πρόωρη εγκατάλειψη του σχολείου και την έναρξη της χρήσης ουσιών και που αφορούν κυρίως δυσμενείς εμπειρίες ζωής κατά την παιδική ηλικία. Η εργασία προτείνει την εφαρμογή προγραμμάτων διά βίου μάθησης και μη τυπικής εκπαίδευσης στο σύνολο της σχολικής κοινότητας για την πρόληψη της σχολικής διαρροής και της χρήσης ουσιών.
Σκοπός της παρούσας ερευνητικής μελέτης είναι η διερεύνηση των δυσμενών εμπειριών ζωής κατά την παιδική ηλικία και η σύνδεση αυτών με την κατάχρηση ουσιών και την έλλειψη στέγης στην ενήλικη ζωή. Συμμετέχοντες στη μελέτη είναι έντεκα άτομα, άντρες και γυναίκες, που παρακολουθούν τα προγράμματα των Μονάδων Υποκατάστασης Βουπρενορφίνης του ΟΚΑΝΑ (ΜΟΘΕ) στη Βόρεια Ελλάδα. Η μεθοδολογία διεξαγωγής της συγκεκριμένης έρευνας βασίζεται στη βιογραφική αφηγηματική προσέγγιση, ένα εργαλείο ποιοτικής έρευνας, που κρίθηκε ως καταλληλότερο για τη σε βάθος μελέτη των δυσμενών εμπειριών ζωής και την αλληλεπίδραση αυτών με την πρόωρη εγκατάλειψη του σχολείου, την κατάχρηση ουσιών και την αστεγία. Η επεξεργασία των βιογραφιών που συγκεντρώθηκαν έδειξε ότι σε όλες τις περιπτώσεις οι δυσμενείς εμπειρίες ζωής και η απώλεια/εναλλαγή στέγης χαρακτήριζε ως κεντρικό βίωμα της παιδικής ηλικίας τις αφηγήσεις όλων των συμμετεχόντων/ουσών και προηγήθηκε της πρόωρης εγκατάλειψης του σχολείου και της εμφάνισης της κατάχρησης ουσιών, η οποία προέκυψε μεταγενέστερα ως μια προσπάθεια ανακούφισης και «αυτοθεραπείας».
Η αποτρεπτική στρατηγική του Ισραήλ συχνά θεωρείται ένα παράδειγμα προς μίμηση για κράτη, τα οποία αντιμετωπίζουν υπαρξιακές απειλές από πλευράς ισχυροτέρων συμμαχιών ή αναθεωρητικών δρώντων. Οι στρατιωτικές ικανότητες, η πολιτική βούληση, η εκμετάλλευση των από καιρού εις καιρόν ανακατανομών ισχύος και ο στρατηγικός σχεδιασμός, στοιχεία διασυνδεδεμένα με μια εμπεδωμένη στρατηγική κουλτούρα, θέτουν το πλαίσιο μιας αποτελεσματικής αποτροπής ανεξαρτήτου του μεγέθους των διλημμάτων ασφαλείας ή άλλων προβλημάτωνεις το εσωτερικό. Κατά τις τελευταίες δεκαετίες, η Ελλάς αντιμετωπίζει μία ευδιάκριτη απειλή από πλευράς της Τουρκίας και ως εκ τούτου, ευλόγως έχει προκύψει ένας δημόσιος διάλογος αναφορικώς με τον τρόπο διά του οποίου η Αθήνα θα δύνατο να εξισορροπήσει τις νεοοθωμανικές βλέψεις εις τη Βαλκανική, το Αιγαίο, την Ανατολική Μεσόγειο, την Κύπρο ή ακόμη και το Ιόνιο, με την Τουρκία να εμπλέκεται εκεί μέσω της στρατηγικής συνεργασίας της με την Αλβανία και να υποσκάπτει την ελληνική ναυτική πρωτοκαθεδρία δυτικώς του ηπειρωτικού κορμού. Εντός του συγκεκριμένου πλαισίου, το παρόν κείμενο επιχειρεί να εξετάσει τους λόγους για τους οποίους η ισραηλινή αποτρεπτική στρατηγική έναντι των απειλών κρατικής επιβιώσεως θεωρείται επιτυχής, το ενδεχόμενο να υφίστανται ομοιότητες ή διαφορές σχετικώς με την διϊστορική ιδιοσυστασία των απειλών κατά του Ισραήλ και της Ελλάδος και εν τέλει, πώς αξιολογείται σήμερα η ελληνική αποτρεπτική στρατηγική. Εν κατακλείδι, βασικός σκοπός είναι η σκιαγράφηση δυνητικών προοπτικών συγκλίσεως συμφερόντων και συναντιλήψεως επί προκλήσεως ασφαλείας μεταξύ Ισραήλ και Ελλάδος κυρίως αναφορικώς με την Ανατολική Μεσόγειο.
Η παρούσα μελέτη διερευνά τον θρησκευτικό γραμματισμό και τη θρησκευτικότητα των νέων που αποφοίτησαν το 2020 από τη Γ΄ Λυκείου της ελληνικής Εκπαίδευσηςκαι έχουν διδαχθεί δέκα χρόνια υποχρεωτικά το μάθημα των Θρησκευτικών. Σκοπός της είναι να περιγράψει το επίπεδο του θρησκευτικού γραμματισμού και της θρησκευτικότητάς τους. Η έρευνα πραγματοποιήθηκε από 12-10-2020 μέχρι 20-02-2021 σε 996 απόφοιτους δευτεροβάθμιας εκπαίδευσης μέσω ηλεκτρονικών ερωτηματολογίων. Τα συμπεράσματα που εξάγονται είναι πως οι νέοι στην Ελλάδα κατέχουν μέτρια ποσοστά θρησκευτικών γνώσεων και θρησκευτικότητας. Η συμβολή της έρευνας έγκειται στο ότι παρέχει μία εικόνα για το επίπεδο θρησκευτικού γραμματισμού και θρησκευτικότητας της σύγχρονης γενιάς στην Ελλάδα, η οποία θα έπρεπε να λαμβάνεται υπόψη στον σχεδιασμό του Προγράμματος Σπουδών της Θρησκευτικής Εκπαίδευσης.
The Pomegranate: the magazine for children (To Rodi: to periodiko gia paidia) is a milestone in the history of Greek magazines for children and adolescents. Surprisingly, to date only two studies have been devoted to this issue. Therefore, the present article aims to present a detailed analysis of the first edition of this magazine (1977-1982) and to offer a critical approach and interpretation of its beneficial effect and its large impact on children and adolescents. More specifically, the present article focuses on the magazine’s main features, contributors, readers, and material. The magazin’s columns were systematically designed to create opportunities for acquiring knowledge and skills as well as for creativity, communication and interaction with peers, and entertainment. Many recognized and young writers and illustrators as well as remarkable literary works and works of art came to the fore. The magazine undoubtedly promoted children’s and adolescents’ cognitive, moral, socioemotional, and psychosexual development. To Rodi has left an indelible mark on its readers and is undoubtedly part of the historical line and the genealogy of Greek quality magazines for children and adolescents.
Η παρούσα σύντομη εισήγηση-ανακοίνωση παρουσιάσθηκε με τον τίτλο: «Ηθική και Γονιδιωματική» στο Δεύτερο Πανελλήνιο Συνέδριο Εξατομικευμένης Ιατρικής στις 17 Δεκεμβρίου 2021, στο Ζάππειο Μέγαρο στην Αθήνα. Η εισήγηση επικεντρώνεται στην προσέγγιση των θεμάτων, τα οποία συνδέονται με τη γενετική επεξεργασία του ανθρώπινου γονιδιώματος (genome editing) και με τα συναφή ηθικά διλήμματα που εγείρει η εφαρμογή της Φαρμακογονιδιωματικής. Η Ηθική βασίζεται σε αρχές και κριτήρια ―με όποια ηθική θεωρία κι αν προσεγγίζεται το θέμα― και προβάλλει τα βασικά ανθρώπινα δικαιώματα της προστασίας, της αξιοπρέπειας και της ταυτότητας κάθε ανθρωπίνου όντος, την εγγύηση του σεβασμού της ακεραιότητας και των δικαιωμάτων και θεμελιωδών ελευθεριών, αλλά και την ισότιμη συμμετοχή στο κοινωνικό αγαθό της υγείας και της συνεπαγόμενης θεραπείας του ασθενούς.
The sediment record from Lake Ohrid (Southwestern Balkans) represents the longest continuous lake archive in Europe, extending back to 1.36 Ma. We reconstruct the vegetation history based on pollen analysis of the DEEP core to reveal changes in vegetation cover and forest diversity during glacial–interglacial (G–IG) cycles and early basin development. The earliest lake phase saw a significantly different composition rich in relict tree taxa and few herbs. Subsequent establishment of a permanent steppic herb association around 1.2 Ma implies a threshold response to changes in moisture availability and temperature and gradual adjustment of the basin morphology. A change in the character of G–IG cycles during the Early–Middle Pleistocene Transition is reflected in the record by reorganization of the vegetation from obliquity- to eccentricity-paced cycles. Based on a quantitative analysis of tree taxa richness, the first large-scale decline in tree diversity occurred around 0.94 Ma. Subsequent variations in tree richness were largely driven by the amplitude and duration of G–IG cycles. Significant tree richness declines occurred in periods with abundant dry herb associations, pointing to aridity affecting tree population survival. Assessment of long-term legacy effects between global climate and regional vegetation change reveals a significant influence of cool interglacial conditions on subsequent glacial vegetation composition and diversity. This effect is contrary to observations at high latitudes, where glacial intensity is known to control subsequent interglacial vegetation, and the evidence demonstrates that the Lake Ohrid catchment functioned as a refugium for both thermophilous and temperate tree species.
We predicted a stellar occultation of the bright star Gaia DR1 4332852996360346368 (UCAC4 385-75921) (mV = 14.0 mag) by the centaur 2002 GZ32 for 2017 May 20. Our latest shadow path prediction was favourable to a large region in Europe. Observations were arranged in a broad region inside the nominal shadow path. Series of images were obtained with 29 telescopes throughout Europe and from six of them (five in Spain and one in Greece) we detected the occultation. This is the fourth centaur, besides Chariklo, Chiron, and Bienor, for which a multichord stellar occultation is reported. By means of an elliptical fit to the occultation chords, we obtained the limb of 2002 GZ32 during the occultation, resulting in an ellipse with axes of 305 ± 17 km × 146 ± 8 km. From this limb, thanks to a rotational light curve obtained shortly after the occultation, we derived the geometric albedo of 2002 GZ32 (pV = 0.043 ± 0.007) and a 3D ellipsoidal shape with axes 366 km × 306 km × 120 km. This shape is not fully consistent with a homogeneous body in hydrostatic equilibrium for the known rotation period of 2002 GZ32. The size (albedo) obtained from the occultation is respectively smaller (greater) than that derived from the radiometric technique but compatible within error bars. No rings or debris around 2002 GZ32 were detected from the occultation, but narrow and thin rings cannot be discarded.
This paper aims to determine and sort the rally and break-time duration (including the rest time) in elite men’s and women’s Sitting Volleyball matches. The sample of study comprises 9195 rallies were retrieved from 68 (34 men and 34 women) Sitting Volleyball matches (corresponding to 224 sets) of the 2019 European Sitting Volleyball championship which monitored and recorded. Inter-rater and intra-rater reliability coefficients were estimated using Cohen’s kappa coefficient. The results of the study showed that the total average attempts in the block of serve, setting, attack, block and defence are higher in men compared to women (p≤.001). Also, the duration of the rally was longer in men, 5.98s, compared to 4.98s of women (p≤.001). The non-parametric Kruskal-Wallis test demonstrated that in both genders the highest average rally length was recorded in the 5th set (7.42s for men and 5.4s for women, respectively) and in the 3rd period of that set for men (6.22s) and the 1st period for women (5.06s). For both genders, the highest average break-times were recorded in the 5th set (28.23s for men and 27.73s for women) and, in particular, the 3rd period of that set (23.75s for men and 25.14s for women). According to the study result, one of the reasons contributing to the higher rally length in men’s matches is the higher number of attempts for all Sitting Volleyball skills that men performed comparing to women. The results of this study can be used by players, coaching staff, teams and federations for the organization, design, planning and managing of workouts and matches.
Metasurfaces constitute an emerging technology, allowing for compact manipulation of all degrees of freedom of an incident lightwave. A key ongoing challenge in the design of these structures is how to allow for energy-efficient dynamic (active) operation, particularly for the polarization of incident light, which other standard devices typically cannot efficiently act upon. Here, we present a quasi-two-dimensional magneto-optic metasurface capable of simultaneously high-contrast on/off operation, as well as rotation of the polarization angle of a linearly polarized wave—that is, without converting the incident linear polarization to elliptical, which is normally particularly challenging. Furthermore, the device’s operation is broadband, with a bandwidth of around 5 µm, and can be conveniently manipulated using an external magnetic bias. Our findings, corroborated using two different full-wave simulation approaches, may allow for functional metasurfaces operating in the terahertz (THz) regime, giving rise to robust, energy-efficient, and high-dynamic-range broadband isolation, to be used for a wealth of optoelectronic and communication applications.
Atherosclerosis is a multifactorial disease influenced by genetics, lifestyle and environmental factors. Despite therapeutic advances that reduce the risk of cardiovascular events, atherosclerosis-related diseases remain the leading cause of mortality worldwide. Precise targeting of genes involved in lipoprotein metabolism is an emerging approach for atherosclerosis prevention and treatment. This article focuses on the latest developments, clinical potential and current challenges of monoclonal antibodies, vaccines and genome/transcriptome modification strategies, including antisense oligonucleotides, genome/base editing and gene therapy. Multiple lipid lowering biological therapies have already been approved by the FDA with impressive results to date, while many more promising targets are being pursued in clinical trials or pre-clinical animal models.
Despite considerable progress in the understanding of its neuropathology, Alzheimer's disease (AD) remains a complex disorder with no effective treatment that counteracts the memory deficits and the underlying synaptic malfunction triggered by the accumulation of amyloid beta (Aβ) and Tau protein. Mounting evidence supports a precipitating role for chronic environmental stress and glutamatergic excitotoxicity in AD, suggesting that targeting of glutamate receptor signaling may be a promising approach against both stress and AD pathologies. In light of the limited cognitive benefit of the direct antagonism of NMDA receptors in AD, we here focus on an alternative way to modify glutamatergic signaling through positive allosteric modulation of AMPA receptors, by the use of a PAM-AMPA compound. Using non-transgenic animal model of Aβ oligomer injection as well as the combined stress and Aβ i.c.v. infusion, we demonstrate that positive allosteric modulation of AMPA receptors by PAM-AMPA treatment reverted memory, but not mood, deficits. Furthermore, PAM-AMPA treatment reverted stress/Aβ-driven synaptic missorting of Tau and associated Fyn/GluN2B-driven excitotoxic synaptic signaling accompanied by recovery of neurotransmitter levels in the hippocampus. Our findings suggest that positive allosteric modulation of AMPA receptors restores synaptic integrity and cognitive performance in stress- and Aβ-evoked hippocampal pathology. As the prevalence of AD is increasing at an alarming rate, novel therapeutic targeting of glutamatergic signaling should be further explored against the early stages of AD synaptic malfunction with the goal of attenuating further synaptic damage before it becomes irreversible.
Tauopathies are a group of progressive neurodegenerative disorders characterized by the presence of insoluble intracellular tau filaments in the brain. Evidence suggests that there is a tight connection between mitochondrial dysfunction and tauopathies, including Alzheimer's disease. However, whether mitochondrial dysfunction occurs prior to the detection of tau aggregates in tauopathies remains elusive. Here, we utilized transgenic nematodes expressing the full length of wild type tau in neuronal cells and monitored mitochondrial morphology alterations over time. Although tau-expressing nematodes did not accumulate detectable levels of tau aggregates during larval stages, they displayed increased mitochondrial damage and locomotion defects compared to the control worms. Chelating calcium restored mitochondrial activity and improved motility in the tau-expressing larvae suggesting a link between mitochondrial damage, calcium homeostasis and neuronal impairment in these animals. Our findings suggest that defective mitochondrial function is an early pathogenic event of tauopathies, taking place before tau aggregation and undermining neuronal homeostasis and organismal fitness. Understanding the molecular mechanisms causing mitochondrial dysfunction early in tauopathy will be of significant clinical and therapeutic value and merits further investigation.
In March 2020 the World Health Organization announced a pandemic outbreak. Severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) is the causative pathogen for the coronavirus disease-19 (COVID-19) pandemic. The authorities worldwide use clinical science to identify infected people, but this approach is not able to track all symptomatic and asymptomatic cases due to limited sampling capacity of the testing laboratories. This drawback is eliminated by the Wastewater-Based Epidemiology (WBE) approach. In this review, we summarized the peer-reviewed published literature (available as of September 28, 2020), in the field of WBE. The commonly used steps (sampling, storage, concentration, isolation, detection) of the analytical protocols were identified. The potential limitations of each stage of the protocols and good practices were discussed. Finally, new methods for the efficient detection of SARS-CoV-2 were proposed.
Wilson JN, Thisse D, Lebois M, Jovančević N, Gjestvang D, Canavan R, Rudigier M, Étasse D, Gerst RB, Gaudefroy L, et al.Angular momentum generation in nuclear fission. Nature. 2021;590:566–570.
Various antidepressants are commonly used to treat depression and anxiety disorders, and sex differences have been identified in their efficacy and side effects. Steroids, such as estrogens and testosterone, both in the periphery and locally in the brain, are regarded as important modulators of these sex differences. This review presents published data from preclinical and clinical studies that measure testosterone and estrogen level changes during and/or after acute or chronic administration of different antidepressants. The majority of studies show an interaction between sex hormones and antidepressants on sexual function and behavior, or in depressive symptom alleviation. However, most of the studies omit to investigate antidepressants' effects on circulating levels of gonadal hormones. From data reviewed herein, it is evident that most antidepressants can influence testosterone and estrogen levels. Still, the evidence is conflicting with some studies showing an increase, others decrease or no effect. Most studies are conducted in male animals or humans, underscoring the importance of considering sex as an important variable in such investigations, especially as depression and anxiety disorders are more common in women than men. Therefore, research is needed to elucidate the extent to which antidepressants can influence both peripheral and brain levels of testosterone and estrogens, in males and females, and whether this impacts the effectiveness or side effects of antidepressants.
Argyris AA, Samara S, Blacher J, Papaioannou TG, Stergiou GS, Vlachopoulos C, Wassertheurer S, Weber T, Protogerou AD. 'Apples to oranges' and 'Less is more'. Journal of Hypertension [Internet]. 2021;39(6):1262 - 1264. Website
This paper proposes the establishment of a systematic framework for measuring dimensions of democracy within a university. It is shown that certain indicators internationally established and validated for the measurement of the institutional characteristics of democracy can, through appropriate adaptation, be transferred to the university field. A new model of mapping these characteristics to the university field was built using all available knowledge from international surveys, valid databases and researches conducted using questionnaires and structured interviews, specifically for the purposes of this paper. Chord diagrams, capable of providing meaningful dynamic graphical representations, were employed as a novel evaluative tool that highlights the existence and degree of significant interrelations between democracy indicators and democratic characteristics of the university. As a case study, we have chosen to analyze, compare and contrast the three most representative laws governing the operation of Greek universities for the last 35 years using the proposed model. Its operation, validity and capabilities were verified, after encapsulating the complex interdependencies among its variables, for a large time period, influenced by adverse social and economic changes. Thus, it can be used as an effective tool for comparisons among different universities, with respect to their democratic constitution.
In this article, Part 1 of a two-part series, we run and evaluate the skill of a regional physical–biogeochemical stochastic ocean model based on NEMO. The domain covers the Bay of Biscay at 1/36° resolution, as a case study for open-ocean and coastal shelf dynamics. We generate model ensembles based on assumptions about errors in the atmospheric forcing, the ocean model parameterizations and in the sources and sinks of the biogeochemical variables. The resulting errors are found to be mainly driven by the wind forcing uncertainties, with the rest of the perturbed forcing and parameters locally influencing the ensemble spread. Biogeochemical uncertainties arise from intrinsic ecosystem model errors and from errors in the physical state. Uncertainties in physical forcing and parameterization are found to have a larger impact on chlorophyll spread than uncertainties in ecosystem sources and sinks. The ensembles undergo quantitative verification with respect to observations, focusing on upper-ocean properties. Despite a tendency for ensembles to be generally under-dispersive, they appear to be reasonably consistent with respect to sea surface temperature data. The largest statistical sea-level biases are observed in coastal regions. These biases hint at the presence of high-frequency error sources currently unaccounted for, and suggest that the ensemble-based uncertainties are unfit to model error covariances for assimilation. Model ensembles for chlorophyll appear to be consistent with ocean colour data only at times. The stochastic model is qualitatively evaluated by analysing its ability at generating consistent multivariate incremental model corrections. Corrections to physical properties are associated with large-scale biases between model and data, with diverse characteristics in the open-ocean and the shelves. Mesoscale features imprint their signature on temperature and sea-level corrections, as well as on chlorophyll corrections due to the vertical velocities associated with vortices. Small scale local corrections are visible over the shelves. Chlorophyll information has measurable impact on physical variables.
In this Part 2 article of a two-part series, observations based on satellite missions were used to evaluate the empirical consistency of model ensembles generated via stochastic modelling of ocean physics and biogeochemistry. A high-resolution Bay of Biscay configuration was used as a case study to explore the model error subspace in both the open and coastal ocean. In Part 1 of this work, three experiments were carried out to generate model ensembles by perturbing only physics, only biogeochemistry, and both of them simultaneously. In Part 2 of this work, empirical consistency was checked, first by means of rank histograms projecting the data onto the model ensemble classes, and second, by pattern-selective consistency criteria in the space of “array modes” defined as eigenvectors of the representer matrix. Rank histograms showed large dependency on geographical region and on season for sea surface temperature (SST), sea-level anomaly (SLA), and phytoplankton functional types (PFT), shifting from consistent model-data configurations to large biases because of model ensemble underspread. Consistency for SST array modes was found to be verified at large, small and coastal scales soon after the ensemble spin-up. Array modes for the along-track sea-level showed useful consistent information at large scales and at the mesoscale; for the gridded SLA was verified only at large scale. Array modes showed that biogeochemical model uncertainties generated by stochastic physics, were effectively detected by PFT measurements at large scales, as well as at mesoscale and small-scale. By contrast, perturbing only biogeochemistry, with an identical physical forcing across the ensemble, limits the potential of PFT measurements at detecting and possibly correcting small-scale biogeochemical model errors. When an ensemble was found to be inconsistent with observations along a particular direction (here, an array mode), a plausible reason is that other error processes must have been active in the model, in addition to the ones at work across the ensemble.
In this Part 2 article of a two-part series, observations based on satellite missions were used to evaluate the empirical consistency of model ensembles generated via stochastic modelling of ocean physics and biogeochemistry. A high-resolution Bay of Biscay configuration was used as a case study to explore the model error subspace in both the open and coastal ocean. In Part 1 of this work, three experiments were carried out to generate model ensembles by perturbing only physics, only biogeochemistry, and both of them simultaneously. In Part 2 of this work, empirical consistency was checked, first by means of rank histograms projecting the data onto the model ensemble classes, and second, by pattern-selective consistency criteria in the space of “array modes” defined as eigenvectors of the representer matrix. Rank histograms showed large dependency on geographical region and on season for sea surface temperature (SST), sea-level anomaly (SLA), and phytoplankton functional types (PFT), shifting from consistent model-data configurations to large biases because of model ensemble underspread. Consistency for SST array modes was found to be verified at large, small and coastal scales soon after the ensemble spin-up. Array modes for the along-track sea-level showed useful consistent information at large scales and at the mesoscale; for the gridded SLA was verified only at large scale. Array modes showed that biogeochemical model uncertainties generated by stochastic physics, were effectively detected by PFT measurements at large scales, as well as at mesoscale and small-scale. By contrast, perturbing only biogeochemistry, with an identical physical forcing across the ensemble, limits the potential of PFT measurements at detecting and possibly correcting small-scale biogeochemical model errors. When an ensemble was found to be inconsistent with observations along a particular direction (here, an array mode), a plausible reason is that other error processes must have been active in the model, in addition to the ones at work across the ensemble.
In this article, Part 1 of a two-part series, we run and evaluate the skill of a regional physical–biogeochemical stochastic ocean model based on NEMO. The domain covers the Bay of Biscay at 1/36° resolution, as a case study for open-ocean and coastal shelf dynamics. We generate model ensembles based on assumptions about errors in the atmospheric forcing, the ocean model parameterizations and in the sources and sinks of the biogeochemical variables. The resulting errors are found to be mainly driven by the wind forcing uncertainties, with the rest of the perturbed forcing and parameters locally influencing the ensemble spread. Biogeochemical uncertainties arise from intrinsic ecosystem model errors and from errors in the physical state. Uncertainties in physical forcing and parameterization are found to have a larger impact on chlorophyll spread than uncertainties in ecosystem sources and sinks. The ensembles undergo quantitative verification with respect to observations, focusing on upper-ocean properties. Despite a tendency for ensembles to be generally under-dispersive, they appear to be reasonably consistent with respect to sea surface temperature data. The largest statistical sea-level biases are observed in coastal regions. These biases hint at the presence of high-frequency error sources currently unaccounted for, and suggest that the ensemble-based uncertainties are unfit to model error covariances for assimilation. Model ensembles for chlorophyll appear to be consistent with ocean colour data only at times. The stochastic model is qualitatively evaluated by analysing its ability at generating consistent multivariate incremental model corrections. Corrections to physical properties are associated with large-scale biases between model and data, with diverse characteristics in the open-ocean and the shelves. Mesoscale features imprint their signature on temperature and sea-level corrections, as well as on chlorophyll corrections due to the vertical velocities associated with vortices. Small scale local corrections are visible over the shelves. Chlorophyll information has measurable impact on physical variables.
Tsamakis K, Mueller C, Hortis I, Kallergi M, Tolos I, Alevyzakis E, Siafakas N, Ouranidis A, Tsiptsios D, Kympouropoulos S, et al.Association of antipsychotic use with raised eosinophil count. Experimental and therapeutic medicine. 2021;21(5):1 - 5.
The accurate extraction of a coastline is necessary for various studies of coastal processes, as well as for the management and protection of coastal areas. Very high-resolution satellite imagery has great potential for coastline extraction; however, noises in spectral data can cause significant errors. Here, we present a newly developed Coastal Extraction Tool (CET) that overcomes such errors and allows accurate and time-efficient automated coastline extraction based on a combination of WorldView-2 (WV-2) multispectral imagery and stereo-pair-derived digital surface model (DSM). Coastline extraction is performed and tested on the Iž-Rava island group, situated within the Northern Dalmatian archipelago (Croatia). Extracted coastlines were compared to (a) coastlines extracted from state topographic map (1:25,000), and (b) coastline extracted by another available tool. The accuracy of the extracted coastline was validated with centimeter accuracy reference data acquired using a UAV system (Matrice 600 Pro + MicaSense RedEdge-MX). Within the study area, two small islets were detected that have not been mapped during the earlier coastline mapping efforts. CET proved to be a highly accurate coastline mapping technique that successfully overcomes spectral-induced errors. In future research, we are planning to integrate data obtained by UAVs infrared thermography (IRT) and in situ sensors, measuring sea and land surface temperatures (SST and LST), into the CET, given that this has shown promising results. Considering its accuracy and ease of use, we suggest that CET can be applied for automated coastline extraction in other large and indented coastal areas. Additionally, we suggest that CET could be applied in longitudinal geomorphological coastal erosion studies for the automated detection of spatio-temporal coastline displacement.
Aman Y, Schmauck-Medina T, Hansen M, Morimoto RI, Simon AK, Bjedov I, Palikaras K, Simonsen A, Johansen T, Tavernarakis N, et al.Autophagy in healthy aging and disease. Nat Aging. 2021;1:634-650.Abstract
Autophagy is a fundamental cellular process that eliminates molecules and subcellular elements, including nucleic acids, proteins, lipids and organelles, via lysosome-mediated degradation to promote homeostasis, differentiation, development and survival. While autophagy is intimately linked to health, the intricate relationship among autophagy, aging and disease remains unclear. This Review examines several emerging features of autophagy and postulates how they may be linked to aging as well as to the development and progression of disease. In addition, we discuss current preclinical evidence arguing for the use of autophagy modulators as suppressors of age-related pathologies such as neurodegenerative diseases. Finally, we highlight key questions and propose novel research avenues that will likely reveal new links between autophagy and the hallmarks of aging. Understanding the precise interplay between autophagy and the risk of age-related pathologies across organisms will eventually facilitate the development of clinical applications that promote long-term health.
We study Rabi oscillations in a two-level system within the semiclassical approximation as an archetype test field of the Averaging Method (AM). The population transfer between the two levels is approached within the first and the second order AM. We systematically compare AM predictions with the rotating wave approximation (RWA) and with the complete numerical solution utilizing standard algorithms (NRWA). We study both the resonance (Δ = 0) and out-of-resonance () cases, where Δ = ω − Ω, and ℏΩ = E 2 − E1 is the two-level energetic separation, while ω is the (cyclic) frequency of the electromagnetic field. We introduce three types of dimensionless factors ϵ, i.e., ΩR/Δ, ΩR/Σ, and ΩR/ω, where ΩR is the Rabi (cyclic) frequency and Σ = ω + Ω and explore the range of ϵ where the AM results are equivalent to NRWA. Finally, by allowing for a phase difference in the initial electron wave functions, we explore the prospects coherence can offer. We illustrate that even with equal initial probabilities at the two levels, but with phase difference, strong oscillations can be generated and manipulated.
Aging, genomic stress, and mitochondrial dysfunction are risk factors for neurodegenerative pathologies, such as Parkinson disease (PD). Although genomic instability is associated with aging and mitochondrial impairment, the underlying mechanisms are poorly understood. Here, we show that base excision repair generates genomic stress, promoting age-related neurodegeneration in a Caenorhabditis elegans PD model. A physiological level of NTH-1 DNA glycosylase mediates mitochondrial and nuclear genomic instability, which promote degeneration of dopaminergic neurons in older nematodes. Conversely, NTH-1 deficiency protects against alpha-synuclein-induced neurotoxicity, maintaining neuronal function with age. This apparent paradox is caused by modulation of mitochondrial transcription in NTH-1-deficient cells, and this modulation activates LMD-3, JNK-1, and SKN-1 and induces mitohormesis. The dependance of neuroprotection on mitochondrial transcription highlights the integration of BER and transcription regulation during physiological aging. Finally, whole-exome sequencing of genomic DNA from patients with idiopathic PD suggests that base excision repair might modulate susceptibility to PD in humans.
We study and develop Bayesian models for the analysis of volleyball match outcomes as recorded by the set-difference. Due to the peculiarity of the outcome variable (set-difference) which takes discrete values from −3 to 3, we cannot consider standard models based on the usual Poisson or binomial assumptions used for other sports such as football/soccer. Hence, the first and foremost challenge was to build models appropriate for the set-difference of each volleyball match. Here we consider two major approaches: (a) an ordered multinomial logistic regression model and (b) a model based on a truncated version of the Skellam distribution. For the first model, we consider the set-difference as an ordinal response variable within the framework ofmultinomial logistic regression models. Concerning the second model, we adjust the Skellam distribution to account for the volleyball rules. We fit and compare both models with the same covariate structure as in Karlis & Ntzoufras (2003). Both models are fitted, illustrated and compared within Bayesian framework using data from both the regular season and the play-offs of the season 2016/17 of the Greek national men’s volleyball league A1.
The tangency portfolio, also known as the market portfolio, is the most efficient portfolio and arises from the intercept point of the Capital Market Line (CML) and the efficient frontier. In this paper, a binary optimal tangency portfolio under cardinality constraint (BOTPCC) problem is defined and studied as a nonlinear programming (NLP) problem. Because such NLP problems are widely approached by heuristic, a binary beetle antennae search algorithm is employed to provide a solution to the BTPSCC problem. Our method proved to be a magnificent substitute to other evolutionary algorithms in real-world datasets, based on numerical applications and computer simulations.
Multiple myeloma (MM) is the second most common hematological malignancy, arising from terminally differentiated B cells, namely plasma cells. miRNAs are small non-coding RNAs that participate in the post-transcriptional regulation of gene expression. In this study, we investigated the role of nine miRNAs in MM. CD138+ plasma cells were selected from bone marrow aspirates from MM and smoldering MM (sMM) patients. Total RNA was extracted and in vitro polyadenylated. Next, first-strand cDNA synthesis was performed using an oligo-dT-adapter primer. For the relative quantification of the investigated miRNAs, an in-house real-time quantitative PCR (qPCR) assay was developed. A functional in silico analysis of the miRNAs was also performed. miR-16-5p and miR-155-5p expression was significantly lower in the CD138+ plasma cells of MM patients than in those of sMM patients. Furthermore, lower levels of miR-15a-5p, miR-16-5p, and miR-222-3p were observed in the CD138+ plasma cells of MM patients with osteolytic bone lesions, compared to those without. miR-125b-5p was also overexpressed in the CD138+ plasma cells of MM patients with bone disease that presented with skeletal-related events (SREs). Furthermore, lower levels of miR-223-3p were associated with significantly worse overall survival in MM patients. In conclusion, we propose a miRNA signature with putative clinical utility in MM.
Polycystic ovary syndrome (PCOS) is the most common endocrine condition affecting 6-18{%} of adolescents and is strongly associated with obesity and cardiovascular risk factors, enhancing the risk of atherosclerosis. Thirty-two adolescents with newly diagnosed PCOS were evaluated for lipid profile disorders, insulin resistance, inflammation, non-alcoholic fatty liver disease (NAFLD), and subclinical atherosclerosis through measurements of carotid intima-media thickness (cIMT). The relationships of the above markers with increased body mass index and abdominal obesity were investigated. Twenty-three adolescents (72{%}) were overweight (OW) or obese (OB). The OW/OB group had significantly higher insulin, HOMA-IR, high-sensitive C-reactive protein (hsCRP), visceral adiposity index (VAI), and lipid accumulation product (LAP) levels; and lower glucose-per-insulin ratios and HDL-C levels compared to the healthy weight group. The cIMT and small dense low-density lipoprotein cholesterol (sdLDL-C) levels did not differ between the two groups. Similarly, cIMT and sdLDL-C levels did not differ between PCOS-adolescents and healthy controls. CIMT was positively correlated with systolic blood pressure and waist circumference per height ratio. In conclusion, OW/OB PCOS-adolescents have a cluster of adverse factors predisposing them to atherosclerotic cardiovascular disease. Therefore, early cardiovascular risk assessment, as well as timely and targeted interventions, are necessary for prevention.
We report on the temporal properties of the ultraluminous X-ray (ULX) pulsar M51 ULX-7 inferred from the analysis of the 2018-2020 Swift/X-ray Telescope monitoring data and archival Chandra data obtained over a period of 33 days in 2012. We find an extended low flux state, which might be indicative of propeller transition, lending further support to the interpretation that the neutron star is rotating near equilibrium. Alternatively, this off-state could be related to a variable superorbital period. Moreover, we report the discovery of periodic dips in the X-ray light curve that are associated with the binary orbital period. The presence of the dips implies a configuration where the orbital plane of the binary is closer to an edge-on orientation, and thus demonstrates that favorable geometries are not necessary in order to observe ULX pulsars. These characteristics are similar to those seen in prototypical X-ray pulsars such as Her X-1 and SMC X-1 or other ULX pulsars such as NGC 5907 ULX1.
{The purpose of this study was to analyse selected serve characteristics in top-level male volleyball, with a special focus on detecting adaptations of the serve skill among seasons. The indicators examined were type, position, direction and quality of serve. The sample consisted of 5482 serves from three final phases of different top-level tournaments (Olympic Games 2012
We have analysed the X-ray spectra of all known Ultra-Compact X-ray Binaries (UCXBs), with the purpose of constraining the chemical composition of their accretion disc and donor star. Our investigation was focused on the presence (or absence) of the Fe Kα emission line, which was used as the probe of chemical composition of the disc, based on previously established theoretical predictions for the reflection of X-ray radiation off the surface of C/O-rich or He-rich accretion discs in UCXBs. We have contrasted the results of our spectral analysis to the history of type I X-ray bursts from these systems, which can also indicate donor star composition. We found that UCXBs with prominent and persistent iron Kα emission also featured repeat bursting activity. On the other hand, the UCXBs for which no iron line was detected, appear to have few or no type I X-ray bursts detected over more than a decade of monitoring. Based on Monte Carlo simulations, demonstrating a strong correlation between the Fe Kα line strength and the abundance of C and O in the accretion disc material and given the expected correlation between the H/He abundance and the recurrence rate of type I X-ray bursts, we propose that there is a considerable likelihood that UCXBs with persistent iron emission have He-rich donors, while those that do not, likely have C/O or O/Ne/Mg-rich donors. Our result strongly advocate for the development of more sophisticated simulations of X-ray reflection from hydrogen-poor accretion discs.
BACKGROUND: Tumors can be separated into immunogenic/hot and non-immunogenic/cold on the basis of the presence of tumor-infiltrating lymphocytes (TILs), the expression of PD-L1 and the tumor mutation burden (TMB). In immunogenic tumors, TILs become unable to control tumor growth because their activity is suppressed by different inhibitory pathways, including PD-1/PD-L1. We hypothesized that tumor vaccines may not be active in the immunosuppressive microenvironment of immunogenic/hot tumors while they could be efficient in the immune naive microenvironment of non-immunogenic/cold tumors. METHODS: The randomized phase II Vx-001-201 study investigated the effect of the Vx-001 vaccine as maintenance treatment in metastatic non-small cell lung cancer (NSCLC) patients. Biopsies from 131 (68 placebo and 63 Vx-001) patients were retrospectively analyzed for PD-L1 expression and TIL infiltration. TILs were measured as tumor-associated immune cells (TAICs), CD3-TILs, CD8-TILs and granzyme B-producing TILs (GZMB-TILs). Patients were distinguished into PD-L1(+) and PD-L1(-) and into TIL high and TIL low. FINDINGS: There was no correlation between PD-L1 expression and Vx-001 clinical activity. In contrast, Vx-001 showed a significant improvement of overall survival (OS) vs. placebo in TAIC low (21 vs. 8.1 months, p = 0.003, HR = 0.404, 95% CI 0.219-0.745), CD3-TIL low (21.6 vs. 6.6 months, p < 0.001, HR = 0.279, 95% CI 0.131-0.595), CD8-TIL low (21 vs. 6.6 months, p < 0.001; HR = 0.240, 95% CI 0.11-0.522) and GZMB-TIL low (20.7 vs. 11.1 months, p = 0.011, HR = 0.490, 95% CI 0.278-0.863). Vx-001 did not offer any clinical benefit in patients with TAIC high, CD3-TIL high, CD8-TIL high or GZMB-TIL high tumors. CD3-TIL, CD8-TIL and GZMB-TIL were independent predictive factors of Vx-001 efficacy. CONCLUSIONS: These results support the hypothesis that Vx-001 may be efficient in patients with non-immunogenic/cold but not with immunogenic/hot tumors.
Binary and multiple stellar systems are numerous in our solar neighbourhood with 80 per cent of the solar-type stars being members of systems with high order multiplicity. The Contact Binaries Towards Merging (CoBiToM) Project is a programme that focuses on contact binaries and multiple stellar systems, as a key for understanding stellar nature. The goal is to investigate stellar coalescence and merging processes, as the final state of stellar evolution of low-mass contact binary systems. Obtaining observational data of approximately 100 eclipsing binaries and multiple systems and more than 400 archival systems, the programme aspires to give insights for their physical and orbital parameters and their temporal variations, e.g. the orbital period modulation, spot activity etc. Gravitational phenomena in multiple-star environments will be linked with stellar evolution. A comprehensive analysis will be conducted, in order to investigate the possibility of contact binaries to host planets, as well as the link between inflated hot Jupiters and stellar mergers. The innovation of CoBiToM Project is based on a multimethod approach and a detailed investigation, that will shed light for the first time on the origin of stellar mergers and rapidly rotating stars. In this work, we describe the scientific rationale, the observing facilities to be used and the methods that will be followed to achieve the goals of CoBiToM Project and we present the first results as an example of the current research on evolution of contact binary systems.
Ultra-short orbital period contact binaries (Porb < 0.26 d) host some of the smallest and least massive stars. These systems are faint and rare, and it is believed that they have reached a contact configuration after several Gyrs of evolution via angular momentum loss, mass transfer and mass loss through stellar wind processes. This study is conducted in the frame of Contact Binaries Towards Merging (CoBiToM) Project and presents the results from light curve and orbital analysis of 30 ultra-short orbital period contact binaries, with the aim to investigate the possibility of them being red nova progenitors, eventually producing merger events. Approximately half of the systems exhibit orbital period modulations, as a result of mass transfer or mass loss processes. Although they are in contact, their fill-out factor is low (less than 30 per cent), while their mass ratio is larger than the one in longer period contact binaries. The present study investigates the orbital stability of these systems and examines their physical and orbital parameters in comparison to those of the entire sample of known and well-studied contact binaries, based on combined spectroscopic and photometric analysis. It is found that ultra-short orbital period contact binaries have very stable orbits, while very often additional components are gravitationally bound in wide orbits around the central binary system. We confirmed that the evolution of such systems is very slow, which explains why the components of ultra-short orbital period systems are still Main Sequence stars after several Gyrs of evolution.
This study focuses on women’s integration in the military through sports, and particularly coed sports in the Hellenic Military Higher Education Institutions: 1) the Hellenic Army Academy, 2) the Hellenic Military Academy of Corps Officers, 3) the Hellenic Military Nursing Academy, 4) the Hellenic Naval Academy, and 5) the Hellenic Air Force Academy. We argue that coed sports (mixed-gender teams) can be used as an integration tool in military institutions, although research on this topic is scarce. Our study begins with a literature review on gender, the military, and sport combining a qualitative and quantitative approach to facilitate a better understanding of how women and men navigate and perceive the meaning of their mixed-gender military sport experience in the Hellenic Military Higher Education Institutions. Initially, twelve Greek women, active officers in the Armed Forces, took part in a series of semi-structured interviews. The twelve women, all high-ranking military officers today—between the ages of 25 to 49—were randomly chosen. Subsequently, a total of 120 active officers of both genders responded to the Greek version of the "Group Environment Questionnaire" (Angelonidis, 1995). From a total of 18 questions, nine were selected to examine gender integration through sport. The main research question is whether sport in the five military higher education academies/schools in Greece contributes to gender integration as perceived and understood by the 120 participants (female and male officers). The findings showed that integration is a process involving non-isolation, meaning acceptance of the gender subject (the officer cadet/military student) regardless of his/her gender into the team, as opposed to his/her exclusion, and as a result the union-unity-acceptance in a sport team of all the subjects (officer cadets of both genders). According to the results of the analysis, there is a statistically significant interaction between the variables 'joint participation of men and women in sports' and the 'integration of women' in the five Hellenic Military Higher Education Institutions. The results of this study indicate that mixed-gender military sport programs serve as a means for gender integration, unity, and cohesion. Other than strengthening physical capacity, fitness and performance, the findings confirm that coed military sport activities could prevent sexism; eliminate or reduce gender harassment, discrimination, and stereotypes; strengthen interpersonal communication/relationships and teamwork; reinforce team and social cohesion, unity, and cooperation skills.
Keywords: Hegemonic masculinity, Sidestreaming, Gender integration, Women, Armed Forces, Military academies, Coed sports, Mixed-gender activities
This article presents a comparison of the results obtained using the newly proposed Simple Weighted Sum Product method and some prominent multiple criteria decision-making methods. For comparison, several analyses were performed using the Python programming language and its NumPy library. The comparison was also made on a real decision-making problem taken from the literature. The obtained results confirm the high correlation of the results obtained using the Simple Weighted Sum Product method and selected multiple criteria decision-making methods such as TOPSIS, SAW, ARAS, WASPAS, and CoCoSo, which confirms the usability of the Simple Weighted Sum Product method for solving multiple criteria decision-making problems.
Computational biology models of the Volterra-Lotka family, known as competing species models, are used for modelling a triopoly market, with application to the mobile telecommunications in Greece. Using a data sample for 1999-2016, parameter estimation with nonlinear least squares is performed. The findings show that the proportional change in the market share of the two largest companies, Cosmote and Vodafone, depends negatively on the market share of each other. Further, the market share of the marker leader, Cosmote, depends positively on the market share of the smallest company, Wind. The proportional change in the market share of Wind, depends negatively on the market share of the largest company Cosmote but it depends positively by the change in the market share by the second company, Vodafone. In the long-run it was found that the market shares tend to the stable equilibrium point where all three companies will survive with Cosmote having a projected number after eleven years (in 2030) of approximately 7.3 million subscribers, Vodafone 4.9 and Wind 3.7, the total number of projected market size being approximately 16 million customers.
Members of the ubiquitous Nucleobase Ascorbate Transporter (NAT) family are H or Na symporters specific for the cellular uptake of either purines and pyrimidines or L-ascorbic acid. Despite the fact that several bacterial and fungal members have been extensively characterised at a genetic, biochemical or cellular level, and crystal structures of NAT members from Escherichia coli and Aspergillus nidulans have been determined pointing to a mechanism of transport, we have little insight on how substrate selectivity is determined. Here, we present systematic mutational analyses, rational combination of mutations, and novel genetic screens that reveal cryptic context-dependent roles of partially conserved residues in the so-called NAT signature motif in determining the specificity of the UapA transporter of A. nidulans. We show that specific NAT signature motif substitutions, alone and in combinations with each other or with distant mutations in residues known to affect substrate selectivity, lead to novel UapA versions possessing variable transport capacities and specificities for nucleobases. In particular, we show that a UapA version including the quadruple mutation T405S/F406Y/A407S/Q408E in the NAT signature motif (UapA-SYSE) becomes incapable of purine transport, but gains a novel pyrimidine-related profile, which can be further altered to a more promiscuous purine/pyrimidine profile when combined with replacements at distantly located residues, especially at F528. Our results reveal that UapA specificity is genetically highly modifiable and allow us to speculate on how the elevator-type mechanism of transport might account for this flexibility.
QR decomposition (QRD) is of fundamental importance for matrix factorization in both real and complex cases. In this paper, by using zeroing neural dynamics method, a continuous-time model is proposed for solving the time-varying problem of QRD in real-time. The proposed dynamics use time derivative information from a known real or complex matrix. Furthermore, its theoretical analysis is provided to substantiate the convergence and effectiveness of solving the time-varying QRD problem. In addition, numerical experiments in four different-dimensional time-varying matrices show that the proposed model is effective for solving the time-varying QRD problem both in the case of a real or a complex matrix as input.
Motivated by the study of Hörmander's sums-of-squares operators and their generalizations, we define the convolution algebra of proper distributions associated to a singular foliation. We prove that this algebra is represented as continuous linear operators on the spaces of smooth functions and generalized functions on the underlying manifold. This generalizes Schwartz kernel operators to singular foliations. We also define the algebra of smoothing operators in this context and prove that it is a two-sided ideal.
BACKGROUND: The purpose of this study is the development and validation of a novel and robust genotyping method for a new lysyl oxidase-like 1 (LOXL1) intronic polymorphism (rs11638944, C > G) and the investigation of its potential association with pseudoexfoliation syndrome (PXS) and pseudoexfoliation glaucoma (PXG) in a Greek population. MATERIAL AND METHODS: 242 DNA samples from 49 PXS, 64 PXG, 50 primary open-angle glaucoma (POAG) patients and 79 healthy age-matched controls were analyzed. Novel methodologies were developed and optimized, in order to genotype the intronic LOXL1 polymorphism: a) a real-time qPCR and melting curve analysis in the Light Cycler platform for rapid and cost-effective analysis and, b) a conventional PCR-RFLP method for analysis of a small number of samples. In selected samples, validity was checked with the reference DNA Sequencing method. RESULTS: The real-time qPCR methodology was reliable, demonstrating good efficiency, reproducibility, accuracy in genotyping (100% concordance with the PCR-RFLP method and DNA Sequencing), with good allele discrimination (Tm = 53.26 degrees C for C allele, Tm = 61.83 degrees C for G allele, DeltaTm = 8.57 degrees C). The results were characterized by Hardy-Weinberg equilibrium in all groups. An increase from 18% in healthy controls to 61% in PXS patients was detected for the G/G homozygote thus, the C allele is protective for PXS with OR = 0.22 (95%CI: 0.11-0.42, p < .0001). Moreover, an increase from 18% in healthy controls to 70% in PXG patients was detected for the G/G homozygote thus, the C allele is protective for PXG with OR = 0.13 (95%CI: 0.06-0.25, p < .0001). CONCLUSIONS: A statistically significant association was verified for the intronic LOXL1 polymorphism rs11638944 and PXS/PXG in a Greek population
COVID-19 incidence and case fatality rates (CFR) differ among ethnicities, stimulating efforts to pinpoint genetic factors that could explain these phenomena. In this regard, the multiallelic apolipoprotein E (APOE) gene has recently been interrogated in the UK biobank cohort, demonstrating associations of the APOE epsilon4/epsilon4 genotype with COVID-19 severity and mortality. The frequency of the epsilon4 allele and thus the distribution of APOE epsilon4/epsilon4 genotype may differ among populations. We have assessed APOE genotypes in 1638 Greek individuals, based on haplotypes derived from SNP rs7412 and rs429358 and found reduced frequency of epsilon4/epsilon4 compared to the British cohort. Herein we discuss this finding in relation to CFR and hypothesize on the potential mechanisms linking APOE epsilon4/epsilon4 to severe COVID-19. We postulate that the metabolic deregulation ensued by APOE4, manifested by elevated cholesterol and oxidized lipoprotein levels, may be central to heightened pneumocyte susceptibility to infection and to exaggerated lung inflammation associated with the epsilon4/epsilon4 genotype. We also discuss putative dietary and pharmacological approaches for the prevention and management of COVID-19 in APOE epsilon4/epsilon4 individuals.
Tsamakis K, Tsiptsios D, Ouranidis A, Mueller C, Schizas D, Terniotis C, Nikolakakis N, Tyros G, Kympouropoulos S, Lazaris A, et al.COVID‑19 and its consequences on mental health. Experimental and therapeutic medicine. 2021;21(3):1 - 1.
BACKGROUND: This study aimed to determine the impact of pulmonary complications on death after surgery both before and during the severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) pandemic.
METHODS: This was a patient-level, comparative analysis of two, international prospective cohort studies: one before the pandemic (January-October 2019) and the second during the SARS-CoV-2 pandemic (local emergence of COVID-19 up to 19 April 2020). Both included patients undergoing elective resection of an intra-abdominal cancer with curative intent across five surgical oncology disciplines. Patient selection and rates of 30-day postoperative pulmonary complications were compared. The primary outcome was 30-day postoperative mortality. Mediation analysis using a natural-effects model was used to estimate the proportion of deaths during the pandemic attributable to SARS-CoV-2 infection.
RESULTS: This study included 7402 patients from 50 countries; 3031 (40.9 per cent) underwent surgery before and 4371 (59.1 per cent) during the pandemic. Overall, 4.3 per cent (187 of 4371) developed postoperative SARS-CoV-2 in the pandemic cohort. The pulmonary complication rate was similar (7.1 per cent (216 of 3031) versus 6.3 per cent (274 of 4371); P = 0.158) but the mortality rate was significantly higher (0.7 per cent (20 of 3031) versus 2.0 per cent (87 of 4371); P < 0.001) among patients who had surgery during the pandemic. The adjusted odds of death were higher during than before the pandemic (odds ratio (OR) 2.72, 95 per cent c.i. 1.58 to 4.67; P < 0.001). In mediation analysis, 54.8 per cent of excess postoperative deaths during the pandemic were estimated to be attributable to SARS-CoV-2 (OR 1.73, 1.40 to 2.13; P < 0.001).
CONCLUSION: Although providers may have selected patients with a lower risk profile for surgery during the pandemic, this did not mitigate the likelihood of death through SARS-CoV-2 infection. Care providers must act urgently to protect surgical patients from SARS-CoV-2 infection.
The timing and character of coarse siliciclastic sediment delivered to deep-water environments in active rift basins is governed by the complicated interactions of tectonics, climate, eustasy, hinterland geology, and shelf process regime. The stratigraphic archives of deep-water syn-rift basin-fills provide records of palaeoenvironmental changes (e.g. climate and vegetation) in onshore catchments, particularly where they are connected by narrow shelves. However, a chronostratigraphically constrained record of climatic fluctuations and process responses in the hinterland source area recorded in deep-water deposits is rare. Here, we integrate a fully cored research borehole with outcrop exposures of deep-water syn-rift stratigraphy to reconstruct palaeoenvironmental change within the stratigraphy of the West Xylokastro Fault Block in the Corinth Rift, Greece. We used palaeomagnetic and palynological analyses from borehole core samples to develop a chronostratigraphic and palaeoenvironmental model, which we compare to global records of Early-Mid Pleistocene climate and eustatic change. This framework allows establishment of a chronostratigraphic and palaeoenvironmental context to stratigraphic variability encountered in outcrop and in the borehole. Our results show that the ∼240 m thick studied succession was deposited from ∼1.1 to 0.6 Ma across the Early-to Mid-Pleistocene transition. During the Early Pleistocene, obliquity-paced climatic variability is largely coherent with vegetation changes of forest coverage within catchments on the southern margin of the Corinth Rift. Large magnitude, eccentricity-paced cyclicity dominant after the Mid-Pleistocene Transition can alter sediment supply from onshore catchments during the warming stages of severe interglacials where expansion of forest cover may trap sediment within catchments. Conglomeratic grade sediment delivery to the deep-water is enhanced during glacial periods, interpreted to reflect sparse forest cover and large winter storms, and during semi-arid, grassland-dominated interglacial highstands during severe interglacials. Base-level rise during minor interglacials is easily outpaced by high sediment supply and is seldom represented stratigraphically. The study demonstrates the value of integrated palynological and sedimentological studies, whilst applying a conservative approach to interpretation when dealing with sparse palynological records from proximal deep-water stratigraphy. The case study provides conceptual models where climatic and vegetation changes can begin to be incorporated as a key control on sediment flux from onshore drainage basins to deep-water syn-rift successions.
BACKGROUND AND PURPOSE: Adolescent cannabis use is associated with adult psychopathology. When Δ(9) -tetrahydrocannabinol (THC), mainly in high doses, is administered to adolescence rats there are also long lasting effects in adults. This study aims to determine the specific adult bio-behavioural profile after adolescent low-dose THC, which better mirrors adolescent recreational cannabis use. EXPERIMENTAL APPROACH: Adolescent male Sprague-Dawley rats were treated with escalating low-dose of THC. In adulthood, they were evaluated for their spontaneous locomotion, sensorimotor gating, higher order and spatial cognitive functions. Dopaminergic activity and cannabinoid receptor expression were measured in distinct brain regions. Hippocampal neurogenic activity of neural stem cells was determined and protein levels of neuroplasticity-related biomarkers were quantified. Adolescent low-dose THC exposure increased spontaneous open-field activity, without affecting prepulse inhibition and attentional set-shifting performance. Region-specific dopaminergic alterations and CB(1) receptor up-regulation in the prefrontal cortex were observed. Impaired spatial memory, as assessed with the object location task and Morris water maze test, was associated with significantly decreased proliferative activity (SOX2-positive cells), neurogenic potential (decreased doublecortin-positive cells) in the adult hippocampus and defective neuroplasticity, including reduced BDNF expression in the hippocampus and prefrontal cortex. KEY RESULTS: Our findings reveal the adverse impact of adolescent low-dose THC on the psychomotor profile, dopaminergic neurotransmission, compensatory cannabinoid receptor response, cognition-related neurobiological and behavioural functions. CONCLUSION AND IMPLICATIONS: Our adolescent low-dose THC animal model does not induce tangible psychotic-like effects, such as those reported in high-dose THC studies, but it impairs cognitive functions and points to hippocampal vulnerability and disrupted neurogenesis.
Research in English as a Lingua Franca (ELF), that is the medium of communication between people who come from different linguacultural backgrounds, has created a rich body of work in various areas. This article focuses on a more recent development of this research for teachers and teacher educators in the perspective of critical language education (CLE). We explore how ELF research, both the linguistic/discourse-oriented one and the pedagogic-oriented one, can benefit from its links to CLE, with its understanding of teaching for social change. We then refer to aspects of critical transformative theory that become relevant in designing and implementing ELF-aware teacher education programmes, focusing especially on three recursive (non-linear) components, i.e. the phase of exposure, the phase of critical awareness and the phase of development of actions that teachers can implement in their teaching. We finish by exploring the critical role of assessment in language education and conclude by inviting teachers and educators to become involved in ELF research for CLE.
BACKGROUND: Parkinsonian symptoms are common adverse effects of antipsychotics. Older adults are particularly vulnerable to drug-induced parkinsonism. Nonetheless, parkinsonian symptoms in seniors treated with antipsychotics cannot be straightforwardly attributed to antipsychotic medication. A comprehensive diagnostic workup is necessary in many cases in order to shed light on the cause of such symptoms in this patient population. CASE SERIES: Eight cases of hospitalized depressed older adults with parkinsonian symptoms, who were treated for at least one year with antipsychotics, are reported. Based on neurological consultation, structural brain imaging and Ioflupane (I-123) dopamine transporter (DAT) single photon emission computerized tomography (SPECT), Parkinson's disease was diagnosed in one case, idiopathic tremor in another, vascular parkinsonism in another one, while in another individual parkinsonian symptoms persisted at 12-month post-discharge follow-up even though his/her symptoms were classified as drug-induced on discharge. In four patients, parkinsonian symptoms were definitely drug-induced and no movement disturbances were reported at follow-up. CONCLUSIONS: Differences in the cause and outcome of parkinsonian symptoms in seniors treated with antipsychotics merit systematic and in-depth study considering the therapeutic and prognostic implications of an accurate detection of the cause of such symptoms. Familiarizing clinical psychiatrists with these differences could pave the way towards approaching seniors with severe, atypical and/or persistent parkinsonian symptoms in a more individualized diagnostic and therapeutic manner, and towards more cautious prescribing of antipsychotics in this age group.
We investigate the long-term variability of the iron K α line in the spectra of two ultracompact X-ray sources (UCXBs) with C/O-rich donors. We revisit archival observations from five different X-ray telescopes, over an ∼20-yr period. Adopting physically motivated models for the spectral continuum, we probe the long-term evolution of the source emission in a self-consistent manner enabling physical interpretation of potential variability of the primary X-ray continuum emission and/or any emission lines from reflection off the accretion disc. We find that the spectral shape and flux of the source emission (for both objects) has remained almost constant throughout all the observations, displaying only minor variability in some spectral parameters and the source flux (largest variation is an ∼25 per cent drop in the flux of Swift J1756.9-2508). We note a striking variability of the Fe K α line that fluctuates from a notable equivalent width of ∼66-100 eV in 4U 1543-624 and ∼170 eV in Swift J1756.9-2508 , to non-detections with upper limits of 2-8 eV. We argue that the disappearance of the iron line is due to the screening of the Fe K α line by the overabundant oxygen in the C/O-rich UCXBs. This effect is cancelled when oxygen becomes fully ionized in the inner disc region, resulting in the variability of the Fe K α line in an otherwise unaltered spectral shape. This finding supports earlier predictions on the consequences of H-poor, C/O-rich accretion disc on reflection-induced fluorescent lines in the spectra of UCXBs.
Context. Most ultra-luminous X-ray sources (ULXs) are now thought to be powered by stellar-mass compact objects accreting at super-Eddington rates. While the discovery of evolutionary cycles have marked a breakthrough in our understanding of the accretion flow changes in the sub-Eddington regime in Galactic black hole binaries, their evidence in the super-Eddington regime has so far remained elusive. However, recent circumstantial evidence hinted at the presence of a recurrent evolutionary cycle in two archetypal ULXs: Holmberg II X-1 and NGC 5204 X-1. Aims: We aim to build on our previous work and exploit the long-term high-cadence monitoring of Swift-XRT in order to provide robust evidence of the evolutionary cycle in these two sources and investigate the main physical parameters inducing their spectral transitions. Methods: We studied the long-term evolution of both sources using hardness-intensity diagrams (HID) and by means of Lomb-Scargle periodograms and Gaussian process modelling to look for periodic variability. We also applied a physically motivated model to the combined Chandra, XMM-Newton, NuSTAR, and Swift-XRT data of each of the source spectral states. Results: We robustly show that both sources follow a clear and recurrent evolutionary pattern in the HID that can be characterised by the hard ultra-luminous (HUL) and soft ultra-luminous (SUL) spectral regimes, and a third state with characteristics similar to the super-soft ultra-luminous (SSUL) state. The transitions between the soft states seem consistent with aperiodic variability, as revealed by a timing analysis of the light curve of Holmberg II X-1; albeit, further investigation is warranted. The light curve of NGC 5204 X-1 shows a stable periodicity on a longer baseline of ∼200 days, possibly associated with the duration of the evolutionary cycle. Conclusions: The similarities between both sources provide strong evidence of both systems hosting the same type of accretor and/or accretion flow geometry. We support a scenario in which the spectral changes from HUL to SUL are due to a periodic increase of the mass-transfer rate and subsequent narrowing of the opening angle of the super-critical funnel. The narrower funnel, combined with stochastic variability imprinted by the wind, might explain the rapid and aperiodic variability responsible for the SUL-SSUL spectral changes. The nature of the longer periodicity of NGC 5204 X-1 remains unclear, and robust determination of the orbital period of these sources could shed light on the nature of the periodic modulation found. Based on the similarities between the two sources, a long periodicity should be detectable in Holmberg II X-1 with future monitoring.
. Journal of Posthuman Studies [Internet]. 2021;5(2):206–220.
The language of arboreal metamorphosis in Han Kang’s The Vegetarian notonly invokes the Ovidian myth of Daphne and Apollo but also establishes apost-anthropocentric perspective according to which the irreducible materialand symbolic connections between humans and other entities are brought tolight. Drawing on the Derridean concept of carnophallogocentrism, on onehand, and on posthuman feminist scholarship, on the other, this article arguesthat the protagonist’s gradual release from her bond to Anthropos to embraceforms of plant life highlights feminist posthumanism’s attempt to explore theintricate relationships of human beings with each other and other species outsidethe parameters of anthropocentrism.
. Physics in Perspective [Internet]. 2021;23(4):181-201.
In this paper, we employ Ian Hacking’s insight that ‘‘unity’’ has a double meaning, singleness and harmonious integration, to revisit a major episode from the recent history of CERN: the UA1 and UA2 experiments in the early 1980s, which led to the discovery of the W and Z bosons. CERN is a complex institution, where diverse groups are called upon to cooperate. We argue that this lack of unity, in the first sense of the term, is counterbalanced by specific mechanisms of integration, so that CERN achieves its standing as a unified organization. The UA1/UA2 episode highlights this interplay between unity and disunity. The UA2 experiment was designed and carried out in order to confirm the validity of the results obtained by UA1. The two experimental teams, working independently and with different mentalities, built separate detectors and refrained from systematically sharing their data. This gave rise to strong antagonisms and diametrically opposed opinions over what conclusions could legitimately be drawn from the resulting data. Our analysis focuses on the mechanisms which compensated for that disunity and eventually led to a unified consensus between UA1 and UA2.
Dysregulation of the hypothalamus-pituitary-adrenal (HPA) axis is often linked to the neurobiology of depression, though the presence and type of this dysregulation is not a consistent finding. Meanwhile, significant sex differences exist regarding depression and the HPA axis. Animal models of depression simulate certain aspects of the human disease and aim to advance our knowledge regarding its neurobiology and discover new antidepressant treatments. Most animal models of depression induce a depressive-like phenotype taking advantage of stressful experimental conditions, that also increase corticosterone, the main stress hormone in rodents. In this review we present inconsistent results in male and female rodents regarding the interaction between the depressive-like behavioral phenotype and corticosterone. In commonly used models, the female depressive-like phenotype in rodents seems significantly less dependent on the stress hormone corticosterone, whereas the male behavioral response is more evident and associates with variations of corticosterone. Further research and clarification of this sex-dependent interaction will have significant ramifications on the improvement of the validity of animal models of depression.
The aim of this article is to make a case for the pertinence of a biographical approach to the history of scientific objects. I first lay out the rationale of that approach by revisiting and extending my earlier work on the topic. I consider the characteristics of scientific objects that motivate the biographical metaphor, and I indicate its virtues and limitations by bringing out the positive and negative analogies between biographies of scientific objects and ordinary biographies. I then point out various ways in which scientific objects may pass away and argue that their demise should be conceptualized as a process. Finally, I sketch the history of the concept of “ether” in nineteenth and early twentieth century physics and suggest that it lends itself particularly well to a biographical treatment. To that effect, I discuss the identity, heuristic character, and recalcitrance of the ether and examine the reasons that may have led to its passing.
Bed sharing—the sharing of a sleeping surface by parents and children—is a common, yet controversial, practice. While most research has focused on the public health aspect of this practice, much less is known regarding its effect on the marital relationship. The aim of the present study was to conduct a scoping review on the impact of parent–infant bed sharing sleeping practices on the sexual and marital relationship of couples. The qualitative synthesis of six studies on this topic suggests that overall, bed sharing does not exert a significant negative impact on family functioning; when it does, it appears to be related to incongruent parental beliefs and expectations, especially when bed sharing is not an intentional choice of sleep arrangement, and there are other confounding factors such as fatigue and psychological distress. Suggestions for future studies and clinical implications are discussed.
The discrimination of enantiomers is crucial in biochemistry. However, chiral sensing faces significant limitations due to inherently weak chiroptical signals. Nanophotonics is a promising solution to enhance sensitivity thanks to increased optical chirality maximized by strong electric and magnetic fields. Metallic and dielectric nanoparticles can separately provide electric and magnetic resonances. Here we propose their synergistic combination in hybrid metal–dielectric nanostructures to exploit their dual character for superchiral fields beyond the limits of single particles. For optimal optical chirality, in addition to maximization of the resonance strength, the resonances must spectrally coincide. Simultaneously, their electric and magnetic fields must be parallel and π/2 out of phase and spatially overlap. We demonstrate that the interplay between the strength of the resonances and these optimal conditions constrains the attainable optical chirality in resonant systems. Starting from a simple symmetric nanodimer, we derive closed-form expressions elucidating its fundamental limits of optical chirality. Building on the trade-offs of different classes of dimers, we then suggest an asymmetric dual dimer based on realistic materials. These dual nanoresonators provide strong and decoupled electric and magnetic resonances together with optimal conditions for chiral fields. Finally, we introduce more complex dual building blocks for a metasurface with a record 300-fold enhancement of local optical chirality in nanoscale gaps, enabling circular dichroism enhancement by a factor of 20. By combining analytical insight and practical designs, our results put forward hybrid resonators to increase chiral sensitivity, particularly for small molecular quantities.
This paper provides some new insights into the dual function of expressive speech acts discussed in pragmatic theory as either expressions of genuine emotions or conventionalised acts of courtesy. Drawing on the framework of interpersonal pragmatics, it analyses signs displayed on the doors of closed businesses in Athens and London during the first lockdown of the Covid-19 pandemic. These closure signs are characterised by a heavy use of relational features, including four expressive speech acts, namely greetings, apologies, thanks and wishes, which form the focus of the analysis. The relational work performed by these speech acts reflects the social changes brought about by the pandemic as well as the business owners’ attempts to retain their customers. The expressive speech acts featured on the signs are evaluated against the norms set out by the genre of closure signs. The comparative angle of the study, on the other hand, links the discussion to norms related to the display of emotions and to the use of conventionalised formulae in the two countries under study, thus revealing culture-specific perspectives on the dual function of expressive speech acts.
BACKGROUND: COVID-19 pandemic presented an unexpected challenge for the surgical community in general and Minimally Invasive Surgery (MIS) specialists in particular. This document aims to summarize recent evidence and experts' opinion and formulate recommendations to guide the surgical community on how to best organize the recovery plan for surgical activity across different sub-specialities after the COVID-19 pandemic. METHODS: Recommendations were developed through a Delphi process for establishment of expert consensus. Domain topics were formulated and subsequently subdivided into questions pertinent to different surgical specialities following the COVID-19 crisis. Sixty-five experts from 24 countries, representing the entire EAES board, were invited. Fifty clinicians and six engineers accepted the invitation and drafted statements based on specific key questions. Anonymous voting on the statements was performed until consensus was achieved, defined by at least 70% agreement. RESULTS: A total of 92 consensus statements were formulated with regard to safe resumption of surgery across eight domains, addressing general surgery, upper GI, lower GI, bariatrics, endocrine, HPB, abdominal wall and technology/research. The statements addressed elective and emergency services across all subspecialties with specific attention to the role of MIS during the recovery plan. Eighty-four of the statements were approved during the first round of Delphi voting (91.3%) and another 8 during the following round after substantial modification, resulting in a 100% consensus. CONCLUSION: The recommendations formulated by the EAES board establish a framework for resumption of surgery following COVID-19 pandemic with particular focus on the role of MIS across surgical specialities. The statements have the potential for wide application in the clinical setting, education activities and research work across different healthcare systems.
Lekkas E, Agorastos K, Mavroulis S, Kranis C, Skourtsos E, Carydis P, Gogou M, Katsetsiadou KN, Papadopoulos G, Triantafyllou I. The early March 2021 Thessaly earthquake sequence. Newsl. Environ. Disaster Cris. Manag. Strateg. 2021;22.
Climate change education (CCE) fosters the skills and behavioral patterns of students in regards to climate-related challenges and risks. Despite its importance, the integration of CCE in schools is challenging due to the interdisciplinary nature of climate science and the obstacles and demands of everyday school reality. Here, we examine the case of satellite Remote Sensing (RS) for Earth Observation (EO) as an innovative tool for facilitating CCE. We focus on Greece, a country that, despite being a hot spot for climate change, shows a low level of CCE integration in schools and awareness for EO-based educational resources. Based on interviews with in-service teachers, our research reveals the following: (a) there is a high interest in how satellites depict environmental phenomena; (b) EO is considered an efficient vehicle for promoting CCE in schools because it illustrates climate change impacts most effectively; (c) local natural disasters, such as intense forest fires and floods, are more familiar to students and, thus, preferable for teaching when compared to global issues, such as the greenhouse effect and sea level rise; and (d) educators are in favor of short, hands-on, EO-based activities (also known as “activity-shots”), as the most useful material format for integrating climate change topics in their everyday teaching practice.
Climate change education (CCE) fosters the skills and behavioral patterns of students in regards to climate-related challenges and risks. Despite its importance, the integration of CCE in schools is challenging due to the interdisciplinary nature of climate science and the obstacles and demands of everyday school reality. Here, we examine the case of satellite Remote Sensing (RS) for Earth Observation (EO) as an innovative tool for facilitating CCE. We focus on Greece, a country that, despite being a hot spot for climate change, shows a low level of CCE integration in schools and awareness for EO-based educational resources. Based on interviews with in-service teachers, our research reveals the following: (a) there is a high interest in how satellites depict environmental phenomena; (b) EO is considered an efficient vehicle for promoting CCE in schools because it illustrates climate change impacts most effectively; (c) local natural disasters, such as intense forest fires and floods, are more familiar to students and, thus, preferable for teaching when compared to global issues, such as the greenhouse effect and sea level rise; and (d) educators are in favor of short, hands-on, EO-based activities (also known as “activity-shots”), as the most useful material format for integrating climate change topics in their everyday teaching practice.
We employ the extended boundary condition method (EBCM) that we properly extend so as to describe gyroelectric and gyromagnetic (i.e., gyrotropic) anisotropy and report on the electromagnetic (EM) complex resonances of magnetooptic (i.e., gyroelectric) bodies of revolution (BoRs), as well as on the complex magnetic plasmon resonances (MPRs) of ferrite (i.e., gyromagnetic) BoRs. The proposed extension is based on an alternative scheme for the expansion of the EM field inside a gyrotropic medium, namely, a discrete eigenfunction (DE) expansion in terms of spherical vector wave functions (SVWFs). This approach provides the transition matrix (namely, T-matrix) that allows not only for the direct computation of the scattered field from the incident one, but also for the determination of the complex resonances of open (i.e., situated in free space) gyrotropic BoR resonators. The EBCM is validated on two levels: first, by calculating the EM scattering from various BoRs, including anisotropic spheroids, cylinders, and rods, and comparing with HFSS commercial software; second, by computing the complex eigenfrequency spectrum of gyroelectric spheroidal resonators and comparing with a recently developed rigorous technique for the EM modeling of anisotropic spheroids.
This paper examines the impact of the European Central Bank’s unconventional monetary policy (UMP) on bank lending supply and performance in the euro area, through comparing the evolution of bank-specific variables before and after the UMP implementation. By using a dynamic panel data analysis on banks across discrete country groups (euro zone, core, peripheral) and by controlling for bank-specific and country-level variables, we provide evidence that the bank lending decisions and performance of euro zone banks are not UMP driven, implying the limited ability of the ECB to enhance the effectiveness of banks’ lending channel and to affect banks’ profitability during the crisis. Our findings also suggest that different criteria determine banks’ lending strategy before the UMP period, bank credit strategies vary across the country samples, while the weaker economies’ banks seem to underestimate the impact of liquidity risk on their lending activity.
BACKGROUND: The driving behavior of patients with mild Alzheimer's disease dementia (ADD) and patients with mild cognitive impairment (MCI) is frequently characterized by errors. A genetic factor affecting cognition is apolipoprotein E4 (APOE4), with carriers of APOE4 showing greater episodic memory impairment than non-carriers. However, differences in the driving performance of the two groups have not been investigated. OBJECTIVE: To compare driving performance in APOE4 carriers and matched non-carriers. METHODS: Fourteen APOE4 carriers and 14 non-carriers with amnestic MCI or mild ADD underwent detailed medical and neuropsychological assessment and participated in a driving simulation experiment, involving driving in moderate and high traffic volume in a rural environment. Driving measures were speed, lateral position, headway distance and their SDs, and reaction time. APOE was genotyped through plasma samples. RESULTS: Mixed two-way ANOVAs examining traffic volume and APOE4 status showed a significant effect of traffic volume on all driving variables, but a significant effect of APOE4 on speed variability only. APOE4 carriers were less variable in their speed than non-carriers; this remained significant after a Bonferroni correction. To further examine variability in the driving performance, coefficients of variation (COV) were computed. Larger headway distance COV and smaller lateral position COV were observed in high compared to moderate traffic. APOE4 carriers had smaller speed COV compared to non-carriers. CONCLUSION: The lower speed variability of APOE4 carriers in the absence of neuropsychological test differences indicates reduced speed adaptations, possibly as a compensatory strategy. Simulated driving may be a sensitive method for detecting performance differences in the absence of cognitive differences
BACKGROUND: Surgery is the main modality of cure for solid cancers and was prioritised to continue during COVID-19 outbreaks. This study aimed to identify immediate areas for system strengthening by comparing the delivery of elective cancer surgery during the COVID-19 pandemic in periods of lockdown versus light restriction.
METHODS: This international, prospective, cohort study enrolled 20 006 adult (≥18 years) patients from 466 hospitals in 61 countries with 15 cancer types, who had a decision for curative surgery during the COVID-19 pandemic and were followed up until the point of surgery or cessation of follow-up (Aug 31, 2020). Average national Oxford COVID-19 Stringency Index scores were calculated to define the government response to COVID-19 for each patient for the period they awaited surgery, and classified into light restrictions (index <20), moderate lockdowns (20-60), and full lockdowns (>60). The primary outcome was the non-operation rate (defined as the proportion of patients who did not undergo planned surgery). Cox proportional-hazards regression models were used to explore the associations between lockdowns and non-operation. Intervals from diagnosis to surgery were compared across COVID-19 government response index groups. This study was registered at ClinicalTrials.gov, NCT04384926.
FINDINGS: Of eligible patients awaiting surgery, 2003 (10·0%) of 20 006 did not receive surgery after a median follow-up of 23 weeks (IQR 16-30), all of whom had a COVID-19-related reason given for non-operation. Light restrictions were associated with a 0·6% non-operation rate (26 of 4521), moderate lockdowns with a 5·5% rate (201 of 3646; adjusted hazard ratio [HR] 0·81, 95% CI 0·77-0·84; p<0·0001), and full lockdowns with a 15·0% rate (1775 of 11 827; HR 0·51, 0·50-0·53; p<0·0001). In sensitivity analyses, including adjustment for SARS-CoV-2 case notification rates, moderate lockdowns (HR 0·84, 95% CI 0·80-0·88; p<0·001), and full lockdowns (0·57, 0·54-0·60; p<0·001), remained independently associated with non-operation. Surgery beyond 12 weeks from diagnosis in patients without neoadjuvant therapy increased during lockdowns (374 [9·1%] of 4521 in light restrictions, 317 [10·4%] of 3646 in moderate lockdowns, 2001 [23·8%] of 11 827 in full lockdowns), although there were no differences in resectability rates observed with longer delays.
INTERPRETATION: Cancer surgery systems worldwide were fragile to lockdowns, with one in seven patients who were in regions with full lockdowns not undergoing planned surgery and experiencing longer preoperative delays. Although short-term oncological outcomes were not compromised in those selected for surgery, delays and non-operations might lead to long-term reductions in survival. During current and future periods of societal restriction, the resilience of elective surgery systems requires strengthening, which might include protected elective surgical pathways and long-term investment in surge capacity for acute care during public health emergencies to protect elective staff and services.
FUNDING: National Institute for Health Research Global Health Research Unit, Association of Coloproctology of Great Britain and Ireland, Bowel and Cancer Research, Bowel Disease Research Foundation, Association of Upper Gastrointestinal Surgeons, British Association of Surgical Oncology, British Gynaecological Cancer Society, European Society of Coloproctology, Medtronic, Sarcoma UK, The Urology Foundation, Vascular Society for Great Britain and Ireland, and Yorkshire Cancer Research.
Performance in a volleyball match is the result of a dynamic and interactive process between two teams. The current study aimed to investigate the influence of the quality of opposition on skill performance indicators. A total of 550 teams’ performances (N¼550) from 275 sets of men’s European Championship 2019 was recorded and the effectiveness of 12 parameters from 5 basic volleyball skills was analyzed. A two-step cluster analysis was performed to divide 24 teams into three quality groups (upper, middle, lower) and 6 types of match status were created according to the quality of the opponents. Binomial logistic regression showed that for each type of match, the key performance factors that discrim- inate win and loss are differentiated, while the efficacy of attack win is associated with the success almost with all contexts studied. Other significant parameters were serve aces for matches between upper-quality teams, opponent’s errors for matches between teams of different quality and avoidance of blocked attacks for balanced matches. The findings emphasize the need for coaches to plan strategies that allow players with special serving abilities to risk for an ace, to enhance the side-out skills of their team and to work detailed on attack coverage systems
We aimed to determine the impact of pre-operative isolation on postoperative pulmonary complications after elective surgery during the global SARS-CoV-2 pandemic. We performed an international prospective cohort study including patients undergoing elective surgery in October 2020. Isolation was defined as the period before surgery during which patients did not leave their house or receive visitors from outside their household. The primary outcome was postoperative pulmonary complications, adjusted in multivariable models for measured confounders. Pre-defined sub-group analyses were performed for the primary outcome. A total of 96,454 patients from 114 countries were included and overall, 26,948 (27.9%) patients isolated before surgery. Postoperative pulmonary complications were recorded in 1947 (2.0%) patients of which 227 (11.7%) were associated with SARS-CoV-2 infection. Patients who isolated pre-operatively were older, had more respiratory comorbidities and were more commonly from areas of high SARS-CoV-2 incidence and high-income countries. Although the overall rates of postoperative pulmonary complications were similar in those that isolated and those that did not (2.1% vs 2.0%, respectively), isolation was associated with higher rates of postoperative pulmonary complications after adjustment (adjusted OR 1.20, 95%CI 1.05-1.36, p = 0.005). Sensitivity analyses revealed no further differences when patients were categorised by: pre-operative testing; use of COVID-19-free pathways; or community SARS-CoV-2 prevalence. The rate of postoperative pulmonary complications increased with periods of isolation longer than 3 days, with an OR (95%CI) at 4-7 days or ≥ 8 days of 1.25 (1.04-1.48), p = 0.015 and 1.31 (1.11-1.55), p = 0.001, respectively. Isolation before elective surgery might be associated with a small but clinically important increased risk of postoperative pulmonary complications. Longer periods of isolation showed no reduction in the risk of postoperative pulmonary complications. These findings have significant implications for global provision of elective surgical care.
PURPOSE: As cancer surgery restarts after the first COVID-19 wave, health care providers urgently require data to determine where elective surgery is best performed. This study aimed to determine whether COVID-19-free surgical pathways were associated with lower postoperative pulmonary complication rates compared with hospitals with no defined pathway.
PATIENTS AND METHODS: This international, multicenter cohort study included patients who underwent elective surgery for 10 solid cancer types without preoperative suspicion of SARS-CoV-2. Participating hospitals included patients from local emergence of SARS-CoV-2 until April 19, 2020. At the time of surgery, hospitals were defined as having a COVID-19-free surgical pathway (complete segregation of the operating theater, critical care, and inpatient ward areas) or no defined pathway (incomplete or no segregation, areas shared with patients with COVID-19). The primary outcome was 30-day postoperative pulmonary complications (pneumonia, acute respiratory distress syndrome, unexpected ventilation).
RESULTS: Of 9,171 patients from 447 hospitals in 55 countries, 2,481 were operated on in COVID-19-free surgical pathways. Patients who underwent surgery within COVID-19-free surgical pathways were younger with fewer comorbidities than those in hospitals with no defined pathway but with similar proportions of major surgery. After adjustment, pulmonary complication rates were lower with COVID-19-free surgical pathways (2.2% 4.9%; adjusted odds ratio [aOR], 0.62; 95% CI, 0.44 to 0.86). This was consistent in sensitivity analyses for low-risk patients (American Society of Anesthesiologists grade 1/2), propensity score-matched models, and patients with negative SARS-CoV-2 preoperative tests. The postoperative SARS-CoV-2 infection rate was also lower in COVID-19-free surgical pathways (2.1% 3.6%; aOR, 0.53; 95% CI, 0.36 to 0.76).
CONCLUSION: Within available resources, dedicated COVID-19-free surgical pathways should be established to provide safe elective cancer surgery during current and before future SARS-CoV-2 outbreaks.
Objective The current study aimed to develop a novel milk-based formulation of docetaxel, a sparingly soluble antineoplastic agent, administered so far exclusively by the intravenous route and evaluate its oral bioavailability. Methods Pre-formulation studies included the determination of docetaxel solubility in water-alcohol mixtures as well as short-term content uniformity experiments of the final formulation. The pharmacokinetic (PK) performance of the developed milk-based formulations was further evaluated in vivo in mice using ritonavir, a potent P-glycoprotein inhibitor, as an absorption enhancer of docetaxel and the marketed intravenous docetaxel formulation, Taxotere (R), as a control. Results In vivo PK results in mice showed that all the administered oral docetaxel formulations had limited absorption in the absence of ritonavir. On the contrary, ritonavir co-administration given as pre-treatment significantly enhanced oral bioavailability of both the marketed and milk-based docetaxel formulations; an even more marked increase in drug exposure was observed when ritonavir was incorporated within the docetaxel milk-based formulation. The fixed-dose combination also showed a more prolonged absorption of the drug compared to separate administrations. Conclusions The current study provides insights for the discovery of a novel milk-based formulation that could potentially serve as an alternative, non-toxic and patient-friendly carrier for an acceptable docetaxel oral chemotherapy.
Le « professeur femme » est inventé en 1881 par la toute jeune IIIe République dans le cadre d’une entreprise de large envergure visant à la laïcisation du système scolaire français. Soucieux de ne point nuire au succès d’une oeuvre si importante pour la stabilité du régime même, les républicains s’emploient à faire intégrer cet être « hermaphrodite » tenant autant du masculin que du féminin à la norme. Ainsi est façonnée une nouvelle identité féminine aussi paradoxale que complexe dans la mesure où elle concilie deux extrêmes : celui de la nonne laïque entièrement vouée à ses élèves et, par ailleurs, celui de la savante, usurpatrice d’une profession définie au masculin, indépendante certes, mais au prix du sacrifice de sa féminité.The "professeur femme" was invented in France by the Third Republic in 1881 as part of a large-scale enterprise aimed at secularizing the French school system. Anxious not to harm the success of such an important project for the stability of the regime itself, the Republicans tried to integrate to the feminine norms this "hermaphrodite" human being, which takes as much from the female as it does from the male (Madame le Professeur): first, by taking care to give it specific training as to its scientific and moral content and, in this regard, adequate to the limited knowledge that it must transmit to the future French wives and mothers entrusted to it; then, by endowing it with the qualities of chastity, dedication and self-denial that characterize a female model, "the nun", whom it is called to replace. Thus, was shaped at the end of the 19th century a new feminine identity, as paradoxical as it was complex, since it reconciled two extremes: that of the “lay nun” and, that, complementarily opposed, of a scholar, independent certainly but at the cost of denial and sacrifice of her femininity. At the crossroads of culture and gender, this study based on legislative and administrative texts, archives and French female secondary teachers’ testimonies explores the construction of a particular sexual, gender and professional identity.
The aim of this paper is to highlight issues of scientific literacy that characterize the Greek society in environmental and health issues, and the need to integrate the Teaching of Science and Biology with Health and Environmental Education. This is accomplished by the means of presentation of previous examples from the literature and through the presentation of studies of my own, as well. Thus, it is indicated that this and of course, other societies are characterized by a significant deficit in the familiarity with these matters. Next, I make a historical and personal appraisal on the evolution of the field of environmental health and genetics and try to make some review on its history, due to having the privilege of experiencing close correlation with it almost on its birth. Lastly, it is presented, a proposal for a university course adapted to the needs of present and future teachers combined to its evaluation. The latter was made through a questionnaire and the response of 153 students of education that highly rated the course as it was shown on the Likert scale. All this reveals emphatically the need for integrating the field of Environmental Health Education to Science and Biology teaching. Keywords: course, environmental health, health education, scientific literacy
During the third all-sky survey (eRASS3), the eROSITA instrument (Predehl et al. 2021) aboard the Russian/German Spektrum-Roentgen-Gamma (SRG) mission (Sunyaev et al. 2021) discovered a new X-ray transient, designated as eRASSt J040515.6-745202, and located in the Magellanic Bridge at: RA(J2000)= 04:05:15.30 (61.31456 deg) DEC(J2000)= -74:51:58.1 (-74.86683 deg) with an estimated positional uncertainty of ~5" radius (incl.
eRASSU J050810.4-660653 is a new Be/X-ray binary in the LMC, which was discovered during the beginning of the first all-sky survey of the eROSITA instrument on board the Russian/German Spektrum-Roentgen-Gamma (SRG) mission (ATel#13609).
Rapid advances in next-generation sequencing technology, particularly whole exome sequencing andwhole genome sequencing, have greatly affected our understanding of genetic variation underlying raregenetic diseases. Herein, we describe ethical principles of guiding consent and sharing of genomics researchdata. We also discuss ethical dilemmas in rare diseases research and patient recruitment policiesand address bioethical and societal aspects influencing the ethical framework for genetic testing. Moreover,we focus on addressing ethical issues surrounding research in low- and middle-income countries.Overall, this perspective aims to address key aspects and issues for building proper ethical frameworks,when conducting research involving genomics data with a particular emphasis on rare diseases and geneticstesting.
The anhydrosugars levoglucosan, mannosan and galactosan have been regarded a suitable molecular indicator of natural biomass combustion. Here we evaluate the summed anhydrosugars (SAS) as paleofire indicator in a 6000 year-long fossil core from Agios Floros fen, Peloponnese, Greece, by analyzing charcoal fragments in parallel throughout the sediment sequence. Modern surface soil samples from the same region were analysed for presence of SAS, confirming the biomarker as an indicator of recent fire activity. The highest SAS concentrations in the fossil core were found in sections representing periods of wet conditions both on local and regional scale, and regionally widespread arboreal vegetation. Low or absence of SAS in the fossil core is associated with periods of dryness, regional dominance of non-arboreal vegetation and a fen rather than lake ecosystem at the site. Micro-charcoal fragments were generally more abundant under these conditions. This suggests that SAS yield and deposition may vary with fuel availability and fire behavior which in turn is affected by climate, local moisture and vegetation type. Forest fires result in more SAS compared to grass fires. SAS yield is also favored by low-temperature fires sustained under wet climate conditions. Preservation of SAS is likely to be compromised in the only seasonally wet fen ecosystem under the dry and warm Mediterranean climate conditions. The moist and shallow conditions in the wetland during hot summer months are probably promoting oxidation and biodegradation of the labile SAS molecules compared to the more robust charcoal fragments. Thus, a multiproxy approach - using several proxies, both for fire, hydroclimate and vegetation change - is preferred when aiming to reconstruct past biomass burning from wetland ecosystems in a Mediterranean environment. The micro-charcoal record from Agios Floros reveals significant fire activity between 4400-2800 cal yr BP. This partly overlaps the Bronze Age period, associated with intense human environmental interaction and climate change in this area of Peloponnese, Greece.
Landslides are a critical geological phenomenon with devastating and catastrophic consequences. With the recent advancements in the geoinformation domain, landslide documentation and inventorization can be achieved with automated workflows using aerial platforms such as unmanned aerial vehicles (UAVs). As a result, ultra-high-resolution datasets are available for analysis at low operational costs. In this study, different segmentation and classification approaches were utilized for object-based landslide mapping. An integrated object-based image analysis (OBIA) workflow is presented incorporating orthophotomosaics and digital surface models (DSMs) with expert-based and machine learning (ML) algorithms. For segmentation, trial and errors tests and the Estimation of Scale Parameter 2 (ESP 2) tool were implemented for the evaluation of different scale parameters. For classification, machine learning algorithms (K- Nearest Neighbor, Decision Tree and Random Forest) were assessed with the inclusion of spectral, spatial, and contextual characteristics. For the ML classification of landslide zones 60% of the reference segments have been used for training and 40% for validation of the models. The quality metrics of Precision, Recall, and F1 were implemented to evaluate the models’ performance under the different segmentation configurations. Results highlight higher performances for landslide mapping when DSM information was integrated. Hence, the configuration of spectral and DSM layers with the RF classifier resulted in the highest classification agreement with an F1 value of 0.85.
This paper presents a joint analysis of instrumental and macroseismic data regarding the 19 July 2019, Greece Mw5.1 earthquake occurred west of Athens. This earthquake ruptured a blind, south-dipping normal fault, 23 km WNW of the center of Athens, while its relocated epicentre lies in close vicinity to the one of the 1999 Mw6.0 earthquake. The maximum macroseismic intensity of the 2019 mainshock reached IEMS98 = 7.5. Scarce damage and intensities up to 5–6 were reported in the epicentral area. Higher intensities were observed at larger distances, 12–15 km east and ESE of the epicentre, alongside the banks of Kifissos River, likely related to ground motion amplification due to soft alluvial formations. Similar selectivity of increased ground motions to the east of the epicentre with respect to other azimuths, also observed during the 1981 and 1999 earthquakes, supports eastward rupture directivity of the 2019 mainshock, an effect that is possibly common for the region’s fault system. Damping of seismic effects was observed east of Aegaleo Mountain, a structure suggested to impose a stopping phase in the time histories of the 1999 and 2019 earthquakes (Fig. A1).
Basal progenitors (BPs), including intermediate progenitors and basal radial glia, are generated from apical radial glia and are enriched in gyrencephalic species like humans, contributing to neuronal expansion. Shortly after generation, BPs delaminate towards the subventricular zone, where they further proliferate before differentiation. Gene expression alterations involved in BP delamination and function in humans are poorly understood. Here, we study the role of LGALS3BP, so far known as a cancer biomarker, which is a secreted protein enriched in human neural progenitors (NPCs). We show that individuals with LGALS3BP de novo variants exhibit altered local gyrification, sulcal depth, surface area and thickness in their cortex. Additionally, using cerebral organoids, human fetal tissues and mice, we show that LGALS3BP regulates the position of NPCs. Single-cell RNA-sequencing and proteomics reveal that LGALS3BP-mediated mechanisms involve the extracellular matrix in NPCs' anchoring and migration within the human brain. We propose that its temporal expression influences NPCs' delamination, corticogenesis and gyrification extrinsically.
Context. Supergiant fast X-ray transients (SFXTs) are a peculiar class of supergiant high-mass X-ray binary (HMXB) systems characterised by extreme variability in the X-ray domain. In current models, this is mainly attributed to the clumpy nature of the stellar wind coupled with gating mechanisms involving the spin and magnetic field of the neutron star. Aims: We studied the X-ray properties of the supergiant HMXB XMMU J053108.3-690923 in the Large Magellanic Cloud to understand its nature. Methods: We performed a detailed temporal and spectral analysis of the eROSITA and XMM-Newton data of XMMU J053108.3-690923. Results: We confirm the putative pulsations previously reported for the source with high confidence, certifying its nature as a neutron star in orbit with a supergiant companion. We identify the extremely variable nature of the source in the form of flares seen in the eROSITA light curves. The source flux exhibits a total dynamic range of more than three orders of magnitude, which confirms its nature as an SFXT, and is the first such direct evidence from a HMXB outside our Galaxy exhibiting a very high dynamic range in luminosity as well as a fast flaring behaviour. We detect changes in the hardness ratio during the flaring intervals where the hardness ratio reaches its minimum during the peak of the flare and increases steeply shortly afterwards. This is also supported by the results of the spectral analysis carried out at the peak and off-flare intervals. This scenario is consistent with the presence of dense structures in the supergiant wind of XMMU J053108.3-690923 where the clumpy medium becomes photoionised at the peak of the flare leading to a drop in the photo-electric absorption. Further, we provide an estimate of the clumpiness of the medium and the magnetic field of the neutron star assuming a spin equilibrium condition.
BACKGROUND: Greece has a mean age of first motherhood at 31.5 years, higher than the European average age of 29.4. Delaying conception, however, may be an important non-reversible cause of infertility. The aim of this study was to identify possible knowledge deficits regarding fertility in young adults. METHODS: This was an online survey of young adults, regarding information on intention to parenthood and knowledge on issues affecting fertility. This study was conducted from February to December 2020, aiming for a representative sample of Greek men and women aged 18 and 26 years. The questionnaire was designed by a multidisciplinary group based on the Cardiff Fertility Knowledge Scale, which contained 22 multiple-choice or Likert-scale questions. RESULTS: We obtained responses from 1875 young adults, whose mean age was 22.1 years. About 91.8{%} of men and 94.0{%} of women declared an intention to have children, out of which 44.0{%} wanted to have two and 29.0{%} three children. About 52.0 and 50.8{%} men and women, respectively, aimed to start a family between 31 and 35 years. Residents of rural areas and those with a lower education level more likely aimed to have children before the age of 30. The most prevalent answers for age of ideal parenthood were between 26 and 30 years for a woman and 31-35 years for a man. Smoking, alcohol consumption and sexually transmitted infections were identified as factors affecting both female and male fertility. Half of men and women, respectively, overestimated general success rates of reproductive techniques. CONCLUSION: The knowledge of fertility, particularly with regards to assisted reproductive techniques' success rates, may be overestimated as more young adults plan for having children after the age of 30.
We investigate the impact of the recent COVID-19 pandemic on the time-varying correlation between stock and bond returns. Using daily data on bond and stock returns for ten countries, covering Europe, Asia, US and Australia regions, we identify flight-to-quality episodes during the COVID-19 global pandemic crisis employing both a panel data specification and a wavelet analysis. Our empirical results demonstrate that flights occur simultaneously across countries and are not country-specific events. This finding suggests that the two largest asset classes offered diversification to investors during the recent crisis, when they actually needed it the most.
The purpose of this review is, initially, to emphasize the importance of geoenvironmental education for the promotion and preservation of geological heritage and geoethical values, and based on these, to present the current situation in Greece. Geoeducation is a broader component of environmental education which aims to promote the geological heritage of a place and its geoconservation. It is a key integral tool for tackling environmental issues and therefore further assisting in sustainable development. Greece is known for its exceptional and rare natural beauty, as well as for the abundance of natural resources and its remarkable geological features. For this reason, six global geoparks have already been established in this country. However, its nature protection is mainly considered as the protection of biodiversity, while the term “geodiversity” is almost absent in Greek law. The importance of establishing a legal framework for the protection of geotopes is underlined by the fact that their promotion and rational management create opportunities for sustainable development, as well as to become quality tourist destinations (geotourism) through nature protection and education. Geodiversity can gain public attention and have a positive impact on geotopes protection. Such initiatives can not only improve the protection of geological sites, but also play an important role in their sustainable development.
Cancer is one of the world’s leading causes of human mortality, and the most prevalent type is breast cancer. However, when diagnosed early, breast cancer may be treated. In this paper, a 5-layer feed-forward neuronet model, trained by a novel fuzzy WASD (weights-and-structure-determination) algorithm, called FUZWASD, is introduced and employed to predict whether the breast cancer is benign or malignant. In general, WASD-trained neuronets are known to overcome the limitations of traditional back-propagation neuronets, including slow training speed and local minimum; however, multi-input WASD-trained neuronets with no dimension explosion weakness are few. In this work, a novel FUZWASD algorithm for training neuronets is modeled by embedding a fuzzy logic controller (FLC) in a WASD algorithm, and a multi-input FUZWASD neuronet (MI-FUZWASDN) model for classification problems with no dimension explosion weakness is proposed. The FUZWASD algorithm uses a FLC to map the input data into a specific interval that enhances the accuracy of the weights-direct-determination (WDD) method. In this way, the FUZWASD algorithm detects the optimal weights and structure of the MI-FUZWASDN using a power softplus activation function and while handling the model fitting and validation. Applications on two diagnostic breast cancer datasets validate and demonstrate the MI-FUZWASDN model’s exceptional learning and predicting performance. In addition, for the intrigued user, we have created a MATLAB kit, which is freely accessible via GitHub, to promote and support the results of this work.
Recent advances in sequencing technologies have allowed the in-depth molecular study of tumors, even at the single cell level. Sequencing efforts have uncovered a previously unappreciated heterogeneity among tumor cells, which has been postulated to be the driving force of tumor evolution and to facilitate recurrence, metastasis, and drug resistance. In the current study, focused on early-stage operable non-small cell lung cancer, we used tumor growth in patient-derived xenograft (PDX) models in mice as a fast-forward tumor evolution process to investigate the molecular characteristics of tumor cells that grow in mice, as well as the parameters that affect the grafting efficiency. We found that squamous cell carcinomas grafted significantly more efficiently compared with adenocarcinomas. Advanced stage, patient age and primary tumor size were positively correlated with grafting. Additionally, we isolated and characterized circulating tumor cells (CTC) from patients' peripheral blood and found that the presence of CTCs expressing epithelial-to-mesenchymal (EMT) markers correlated with the grafting potential. Interestingly, exome sequencing of the PDX tumor identified genetic alterations in DNA repair and genome integrity genes that were under-represented in the human primary counterpart. In conclusion, through the generation of a PDX biobank of NSCLC, we identified the clinical and molecular properties of tumors that affected growth in mice.
Frontotemporal dementia (FTD) and amyotrophic lateral sclerosis (ALS) are part of the same pathophysiological spectrum and have common genetic and cerebrospinal fluid (CSF) biomarkers. Our aim here was to identify causative gene variants in a cohort of Greek patients with FTD, ALS and FTD-ALS, to measure levels of CSF biomarkers and to investigate genotype-phenotype/CSF biomarker associations. In this cohort of 130 patients (56 FTD, 58 ALS and 16 FTD-ALS), we performed C9orf72 hexanucleotide repeat expansion analysis, whole exome sequencing and measurement of "classical" (Abeta(42), total tau and phospho-tau) and novel (TDP-43) CSF biomarkers and plasma progranulin. Through these analyses, we identified 14 patients with C9orf72 repeat expansion and 11 patients with causative variants in other genes (three in TARDBP, three in GRN, three in VCP, one in FUS, one in SOD1). In ALS patients, we found that levels of phospho-tau were lower in C9orf72 repeat expansion and MAPT c.855C>T (p.Asp285Asp) carriers compared to non-carriers. Additionally, carriers of rare C9orf72 and APP variants had lower levels of total tau and Abeta(42), respectively. Plasma progranulin levels were decreased in patients carrying GRN pathogenic variants. This study expands the genotypic and phenotypic spectrum of FTD/ALS and offers insights in possible genotypic/CSF biomarker associations
Extracellular matrix (ECM) is a dynamic 3-dimensional network of macromolecules that provides structural support for the cells and tissues. Accumulated knowledge clearly demonstrated over the last decade that ECM plays key regulatory roles since it orchestrates cell signaling, functions, properties and morphology. Extracellularly secreted as well as cell-bound factors are among the major members of the ECM family. Proteins/glycoproteins, such as collagens, elastin, laminins and tenascins, proteoglycans and glycosaminoglycans, hyaluronan, and their cell receptors such as CD44 and integrins, responsible for cell adhesion, comprise a well-organized functional network with significant roles in health and disease. On the other hand, enzymes such as matrix metalloproteinases and specific glycosidases including heparanase and hyaluronidases contribute to matrix remodeling and affect human health. Several cell processes and functions, among them cell proliferation and survival, migration, differentiation, autophagy, angiogenesis, and immunity regulation are affected by certain matrix components. Structural alterations have been also well associated with disease progression. This guide on the composition and functions of the ECM gives a broad overview of the matrisome, the major ECM macromolecules, and their interaction networks within the ECM and with the cell surface, summarizes their main structural features and their roles in tissue organization and cell functions, and emphasizes the importance of specific ECM constituents in disease development and progression as well as the advances in molecular targeting of ECM to design new therapeutic strategies.
Στο άρθρο διερευνώνται οι αντιλήψεις Υποψήφιων Εκπαιδευτικών (ΥΕ), φοιτητών/τριών του Τμ. Θεολογίας ΕΚΠΑ, για τους παράγοντες που επηρεάζουν την αυτο-αποτελεσματικότητά τους στη Πρακτική Άσκηση (ΠΑ) στο σχολείο, στο πλαίσιο της απόκτησης της Παιδαγωγικής και Διδακτικής Επάρκειας. Συμμετείχαν 83 ΥΕ, τη χρονιά 2019-20. Μελετήθηκαν ξεχωριστά τέσσερεις διαστάσεις της μεντορικής καθοδήγησης και συγκεκριμένα: α) η ποιότητα σχέσης Μέντορα και ΥΕ, β) η μεντορική υποστήριξη, γ) η διάρκεια και ο χαρακτήρας της ανατροφοδότησης, δ) η αυτονομία των ΥΕ στην επιλογή και δοκιμασία διδακτικών δραστηριοτήτων, σε συσχέτιση με τις αντιλήψεις των ΥΕ για την αποτελεσματικότητά τους στη διδασκαλία (διδακτική αυτο-αποτελεσματικότητα). Από την ανάλυση δεδομένων προκύπτει ότι η καλή σχέση και η υποστήριξη που δέχονται οι ΥΕ από τους/τις Μέντορες σχετίζεται σε ένα βαθμό θετικά με την αυτο-αποτελεσματικότητά τους στη διδασκαλία. Επίσης, όταν η ανατροφοδότηση λειτουργεί θετικά σε πρακτικό εκπαιδευτικό επίπεδο για τους/τις ΥΕ, αυτό σχετίζεται με την αυτο-αποτελεσματικότητά τους στη διδασκαλία, κάτι που δεν συμβαίνει αντίστοιχα με τη διάρκειά της. Τέλος, όσο μειώνεται η συνεισφορά των Μεντόρων Εκπαιδευτικών (ΜΕ) στην επιλογή και την εφαρμογή των διδακτικών δραστηριοτήτων των ΥΕ, τόσο περισσότερο οι ΥΕ αισθάνονται μεγαλύτερη αυτο-αποτελεσματικότητα στη διδασκαλία. Η έρευνα αναδεικνύει σημαντικά κριτήρια για τον μελλοντικό σχεδιασμό προγραμμάτων ΠΑ φοιτητών/τριών ή εκπαίδευσης Μεντόρων.
. International Journal of Learner Diversity and Identities [Internet]. 2021;28(2):15-30. Publisher's VersionAbstract
Arguing that action research is an appropriate methodological framework in integration projects owing to the unpredictable challenges associated with the particular group of learners, this article focuses on the process ofdesigning, implementing, evaluating, and redesigning a Greek and English language program for the purposes of the“Curing the Limbo” project. It highlights crucial decisions that were made and tested with the involvement of relevantstakeholders in order to respond to the imminent communicative needs of adult refugees, leading to the goal of inclusiveintegration. The article also addresses the challenges faced during the COVID-19 pandemic lockdowns
The detection of a high-energy neutrino from the flaring blazar TXS 0506+056 and the subsequent discovery of a neutrino excess from the same direction have strengthened the hypothesis that blazars are cosmic neutrino sources. The lack, however, of γ-ray flaring activity during the latter period challenges the standard scenario of correlated γ-ray and high-energy neutrino emission in blazars. We propose instead that TeV-PeV neutrinos are produced in coincidence with X-ray flares that are powered by proton synchrotron radiation. In this case, neutrinos are produced by photomeson interactions of protons with their own synchrotron radiation, while MeV to GeV γ-rays are the result of synchrotron-dominated electromagnetic cascades developed in the source. Using a time-dependent approach, we find that this "pure hadronic flaring" hypothesis has several interesting consequences. The X-ray flux is a good proxy for the all-flavor neutrino flux, while certain neutrino-rich X-ray flares may be dark in GeV-TeV γ-rays. Lastly, hadronic X-ray flares are accompanied by an equally bright MeV component that is detectable by proposed missions like e-ASTROGAM and AMEGO. We applied this scenario to the extreme blazar 3HSP J095507.9+355101 which has been associated with IceCube-200107A while undergoing an X-ray flare. We showed that the number of muon and anti-muon neutrinos above 100 TeV during hadronic flares can be up to ˜3-10 times higher than the expected number in standard leptohadronic models. Still, frequent hadronic flaring activity is necessary for explaining the detected neutrino event IceCube-200107A.
The detection of a high-energy neutrino from the flaring blazar TXS 0506+056 and the subsequent discovery of a neutrino excess from the same direction have strengthened the hypothesis that blazars are cosmic neutrino sources. The lack, however, of γ-ray flaring activity during the latter period challenges the standard scenario of correlated γ-ray and high-energy neutrino emission in blazars. We propose instead that TeV-PeV neutrinos are produced in coincidence with X-ray flares that are powered by proton synchrotron radiation. In this case, neutrinos are produced by photomeson interactions of protons with their own synchrotron radiation, while MeV to GeV γ-rays are the result of synchrotron-dominated electromagnetic cascades developed in the source. Using a time-dependent approach, we find that this "pure hadronic flaring" hypothesis has several interesting consequences. The X-ray flux is a good proxy for the all-flavor neutrino flux, while certain neutrino-rich X-ray flares may be dark in GeV-TeV γ-rays. Lastly, hadronic X-ray flares are accompanied by an equally bright MeV component that is detectable by proposed missions like e-ASTROGAM and AMEGO. We applied this scenario to the extreme blazar 3HSP J095507.9+355101 which has been associated with IceCube-200107A while undergoing an X-ray flare. We showed that the number of muon and anti-muon neutrinos above 100 TeV during hadronic flares can be up to ∼3-10 times higher than the expected number in standard leptohadronic models. Still, frequent hadronic flaring activity is necessary for explaining the detected neutrino event IceCube-200107A.
The existence of a calendar anomaly in stock market returns, namely the Halloween Effect, was corroborated by Bouman & Jacobsen (2002). They claimed that returns during May to October are extremely affected by this phenomenon, and hence are lower in comparison with the respective of November to April. This paper investigates the existence of this anomaly in the field of mutual funds for the period 2008-2017. We provide evidence of a robust Halloween effect in the European equity mutual funds market. This effect still exists even after controlling for other seasonal anomalies and dividing our sample according to the size of the funds. Since this calendar anomaly is both statistically and economically significant, we show that an investment based on such seasonal anomaly can be more profitable and effective than the Buy & Hold Strategy without any risk increase. The significant higher returns in winter months are also resulting from close to zero or negative average returns during May to October as well as high positive returns during November to April. It is finally concluded that fund managers do not seem to believe in this anomaly, since they are not reducing their exposure to the equity markets during summer months.
Let $K$ be an infinite field of positive characteristic. We classify all homomorphisms between Weyl modules for $GL_n(K)$, where one of the partitions is a hook. As a consequence we obtain a nonvanishing result concerning homomorphisms between Weyl modules for algebraic groups of type B, C and D when one of the partitions is a hook.
In this paper we attempt a critical appraisal of the relation between history of science and philosophy of science in Ian Hacking’s styles of scientific reasoning project. In our analysis, we employ a distinction between “historical philosophy of science” and “philosophical history of science”: the former aims at addressing philosophical issues, while the latter aims at telling stories about the scientific past that are informed by philosophical considerations. We argue that Hacking practices historical philosophy of science; discuss how his approach is differentiated from the so-called confrontation model; and show that he opts for a strong integration between history and philosophy of science. Finally, we discuss the historiographical implications of his approach and suggest that his aim to maintain a middle position, on the one hand, between contingency and inevitabilism, and, on the other, between internalism and externalism in the explanation of the stability of scientific knowledge, is compromised by his philosophical commitments.
In Greece, the appreciation of industrial buildings is relatively recent, with the legal authorities having recognized their historical value by listing them as monuments. Nineteenth century industrial buildings can be identified as cultural monuments of the past, as well as assist in the reconstruction of urban landscapes. Additionally, individual initiatives, organized by volunteers, present the necessity for documentation through relevant research projects. The reuse of industrial buildings for cultural activities has lately become a common practice. In Athens, a large number of buildings dated to the industrial revolution and that present historical and architectural features worthy of being preserved have been recorded. Following the philosophy of smart cities, this paper presents a digital inventory of the industrial buildings located in the historical center of Athens; many of which have recently been adapted to host cultural activities. Τhe use of smart technology, by creating a digital application for smart phones, will provide access to a continuously enriched registry, via interactive maps. This initiative will promote the buildings’ past and present use and, moreover, the creative concept of their multiple functions. The suggested model of cultural management is applicable to every industrial building in Athens.
Radiolabeled magnetic nanoparticles are promising candidates as dual-modality-contrast-agents (DMCA) for diagnostic applications. The immunocompatibility of a new DMCA is a prerequisite for subsequent in vivo applications. Here, a new DMCA, namely Fe3O4 nanoparticles radiolabeled with Ga-68, is subjected to immunocompatibility tests both in vitro and in vivo. The in vitro immunocompatibility of the DMCA relied on incubation with donated human WBCs and PLTs (five healthy individuals). Optical microscopy (OM) and atomic force microscopy (AFM) were employed for the investigation of the morphological characteristics of WBCs and PLTs. A standard hematology analyzer (HA) provided information on complete blood count. The in vivo immunocompatibility of the DMCA was assessed through its biodistribution among the basic organs of the mononuclear phagocyte system in normal and immunodeficient mice (nine in each group). In addition, Magnetic Resonance Imaging (MRI) data were acquired in normal mice (three). The combined OM, AFM and HA in vitro data showed that although the DMCA promoted noticeable activation of WBCs and PLTs, neither degradation nor clustering were observed. The in vivo data showed no difference of the DMCA biodistribution between the normal and immunodeficient mice, while the MRI data prove the efficacy of the particular DMCA when compared to the non-radiolabeled, parent CA. The combined in vitro and in vivo data prove that the particular DMCA is a promising candidate for future in vivo applications.
OBJECTIVE: To compare three-dimensional (3D) with standard two-dimensional (2D) laparoscopic partial nephrectomy (LPN) with respect to intra- and postoperative outcomes. MATERIAL AND METHODS: Data from 112 patients who underwent transperitoneal LPN from 2012 to 2014 by a single experienced surgeon were collected. Sixty patients (group 1) underwent conventional 2D LPN and 52 patients (group 2) 3D LPN. Perioperative patient, procedure, and tumor data were recorded. The follow-up period was 1-5 years. RESULTS: The two groups had similar patient age (p=0.834) and body mass index (p=0.141). The total laparoscopy time (LT) was shorter in group 2 (119.0 vs. 106.0 min; p=0.009). Warm ischemia times (WITs) were also shorter in group 2 (11.5 vs. 10.0 min; p=0.032). The estimated blood loss (EBL) (350.0 vs. 250.0 mL; p<0.001) and hemoglobin (Hb) decrease (1.55 vs. 1.35 g/dL; p=0.536) were lower in the 3D LPN group. Creatinine (0 vs. 0 g/dL; p=0.610) increase and estimated glomerular filtration rate (eGFR) decrease (0 vs. 0 mL/min/1.73 m(2); p=0.553) did not demonstrate statistically significant differences. Duration of hospitalization (7 vs. 7 days; p=0.099) and complication rates (p=0.559) were similar between the two groups. CONCLUSION: The new-generation 3D laparoscope has a great impact on significant LPN intraoperative parameters, mainly LT, WIT, and EBL. Hb decrease is also in favor of 3D vision, although not dramatically altered. Therefore, 3D LPN appears to be superior to conventional 2D LPNs.
The inherited mutation (R14del) in the calcium regulatory protein phospholamban (PLN) is linked to malignant ventricular arrhythmia with poor prognosis starting at adolescence. However, the underlying early mechanisms that may serve as prognostic factors remain elusive. This study generated humanized mice in which the endogenous gene was replaced with either human wild type or R14del-PLN and addressed the early molecular and cellular pathogenic mechanisms. R14del-PLN mice exhibited stress-induced impairment of atrioventricular conduction, and prolongation of both ventricular activation and repolarization times in association with ventricular tachyarrhythmia, originating from the right ventricle (RV). Most of these distinct electrocardiographic features were remarkably similar to those in R14del-PLN patients. Studies in isolated cardiomyocytes revealed RV-specific calcium defects, including prolonged action potential duration, depressed calcium kinetics and contractile parameters, and elevated diastolic Ca-levels. Ca-sparks were also higher although SR Ca-load was reduced. Accordingly, stress conditions induced after contractions, and inclusion of the CaMKII inhibitor KN93 reversed this proarrhythmic parameter. Compensatory responses included altered expression of key genes associated with Ca-cycling. These data suggest that R14del-PLN cardiomyopathy originates with RV-specific impairment of Ca-cycling and point to the urgent need to improve risk stratification in asymptomatic carriers to prevent fatal arrhythmias and delay cardiomyopathy onset.
In this study, we developed highly sensitive substrates for Surface-Enhanced-Raman-Scattering (SERS) spectroscopy, consisting of silicon nanowires (SiNWs) decorated by silver nanostructures using single-step Metal Assisted Chemical Etching (MACE). One-step MACE was performed on p-type Si substrates by immersion in AgNO3/HF aqueous solutions resulting in the formation of SiNWs decorated by either silver aggregates or dendrites. Specifically, dendrites were formed during SiNWs’ growth in the etchant solution, whereas aggregates were grown after the removal of the dendrites from the SiNWs in HNO3 aqueous solution and subsequent re-immersion of the specimens in a AgNO3/HF aqueous solution by adjusting the growth time to achieve the desired density of silver nanostructures. The dendrites had much larger height than the aggregates. R6G was used as analyte to test the SERS activity of the substrates prepared by the two fabrication processes. The silver aggregates showed a considerably lower limit of detection (LOD) for SERS down to a R6G concentration of 10−13 M, and much better uniformity in terms of detection in comparison with the silver dendritic structures. Enhancement factors in the range 105–1010 were calculated, demonstrating very high SERS sensitivities for analytic applications.
The ISO 15189:2012 standard section 5.9.1 requires laboratories to review results before release, considering quality control, previous results, and clinical information, if any, and to issue documented procedures about it. While laboratory result reporting is generally regarded as part of the post-analytical phase, the result release process requires a general view of the total examination process. Reviewing test results may follow with troubleshooting and test repetition, including reanalyzing an individual sample or resampling. A systematic understanding of the result release may help laboratory professionals carry out appropriate test repetition and ensure the plausibility of laboratory results. In this paper, we addressed the crucial steps in the result release process, including evaluation of sample quality, critical result notification, result reporting, and recommendations for the management of the result release, considering quality control alerts, instrument flags, warning messages, and interference indexes. Error detection tools and plausibility checks mentioned in the present paper can support the daily practice of results release
Some decision-making problems, i.e., multi-criteria decision analysis (MCDA) problems, require taking into account the attitudes of a large number of decision-makers and/or respondents. Therefore, an approach to the transformation of crisp ratings, collected from respondents, in grey interval numbers form based on the median of collected scores, i.e., ratings, is considered in this article. In this way, the simplicity of collecting respondents’ attitudes using crisp values, i.e., by applying some form of Likert scale, is combined with the advantages that can be achieved by using grey interval numbers. In this way, a grey extension of MCDA methods is obtained. The application of the proposed approach was considered in the example of evaluating the websites of tourism organizations by using several MCDA methods. Additionally, an analysis of the application of the proposed approach in the case of a large number of respondents, done in Python, is presented. The advantages of the proposed method, as well as its possible limitations, are summarized.
Introduction: Schizophrenia is a severe psychiatric disorder affecting millions worldwide. However, available treatment options do not fully address the disease. Whereas current antipsychotics may control psychotic symptoms, they seem notoriously ineffective in improving negative and cognitive symptoms or in preventing functional decline. As the etiology of schizophrenia eludes us, the development of valid animal models for screening new drug targets appears to be a strenuous task.Areas covered: In this review, the authors present the key concepts that validate animal models of schizophrenia, as well as the different screening approaches for novel schizophrenia treatments. The models covered are either based on major neurotransmitter systems or neurodevelopmental, immune, and genetic approaches.Expert opinion: Sadly, due to inertia, research focuses on developing 'anti-psychotics', instead of 'anti-schizophrenia' drugs that would tackle the entire syndrome of schizophrenia. Whereas no perfect model may ever exist, combining different experimental designs may enhance validity, as the over-reliance on a single model is inappropriate. Multi-model approaches incorporating vulnerability, the 'two-hit' hypothesis, and endophenotypes offer a promise for developing new strategies for schizophrenia treatment. Forward and reverse translation between preclinical and clinical research will increase the probability of success and limit failures in drug development.
Interleukin-1 beta (IL1β) is primarily produced by monocytes in the periphery and the brain. Yet, IL1β protein levels have to date been investigated in major depressive disorder (MDD) and antidepressant response using either plasma or serum assays although with contradictory results, while mononuclear cell assays are lacking despite their extensive use in other contexts. In this pilot study, we comparatively assessed IL1β in mononuclear lysates and plasma in depressed MDD patients over treatment and healthy controls (HC). We recruited 31 consecutive adult MDD inpatients and 25 HC matched on age, sex, and BMI. Twenty-six patients completed an 8-week follow-up under treatment. IL1β was measured in both lysates and plasma in patients at baseline (T0) and at study end (T1) as well as in HC. We calculated ΔIL1β(%) for both lysates and plasma as IL1β percent changes from T0 to T1. Seventeen patients (65.4% of completers) were responders at T1 and had lower baseline BMI than non-responders (p = 0.029). Baseline IL1β from either plasma or lysates could not efficiently discriminate between depressed patients and HC, or between responders and non-responders. However, the two response groups displayed contrasting IL1β trajectories in lysates but not in plasma assays (response group by time interactions, p = 0.005 and 0.96, respectively). ΔIL1β(%) in lysates predicted response (p = 0.025, AUC = 0.81; accuracy = 84.6%) outperforming ΔIL1β(%) in plasma (p = 0.77, AUC=0.52) and was robust to adjusting for BMI. In conclusion, ΔIL1β(%) in mononuclear lysates may be a longitudinal biomarker of antidepressant response, potentially helpful in avoiding untimely switching of antidepressants, thereby warranting further investigation.
We present a dynamical study of the intermediate polar and dwarf nova cataclysmic variable GK Persei (Nova Persei 1901) based on a multisite optical spectroscopy and R-band photometry campaign. The radial velocity curve of the evolved donor star has a semi-amplitude $K_2=126.4 \pm 0.9 \, \mathrm{km}\, \mathrm{s}^{-1}$ and an orbital period $P=1.996872 \pm 0.000009 \, \mathrm{d}$. We refine the projected rotational velocity of the donor star to $v_\mathrm{rot} \sin i = 52 \pm 2 \, \mathrm{km}\, \mathrm{s}^{-1}$ that, together with K2, provides a donor star to white dwarf mass ratio q = M2/M1 = 0.38 ± 0.03. We also determine the orbital inclination of the system by modelling the phase-folded ellipsoidal light curve and obtain i = 67° ± 5°. The resulting dynamical masses are $M_{1}=1.03^{+0.16}_{-0.11} \, \mathrm{M}_{\odot }$ and $M_2 = 0.39^{+0.07}_{-0.06} \, \mathrm{M}_{\odot }$ at 68 per cent confidence level. The white dwarf dynamical mass is compared with estimates obtained by modelling the decline light curve of the 1901 nova event and X-ray spectroscopy. The best matching mass estimates come from the nova light curve models and an X-ray data analysis that uses the ratio between the Alfvén radius in quiescence and during dwarf nova outburst.
BACKGROUND: Allogeneic cardiosphere-derived cells (CDCs) exert cardioprotective effects when administered intracoronarily after reperfusion in animal models of acute myocardial infarction (AMI). The "no-reflow" phenomenon develops rapidly post-reperfusion and may undermine the efficacy of cell therapy, due to poor cell delivery in areas of microvascular obstruction (MVO). We hypothesized that CDC-induced cardioprotection would be enhanced by cell administration prior to reperfusion, when microvasculature is still relatively intact, to facilitate widespread cell delivery within the ischemic area. METHODS AND RESULTS: We studied 81 farm pigs; 55 completed the specified protocols. A dose-optimization study in infarcted pigs demonstrated that the doses of 5 million and 10 million CDCs are the maximum safe doses that can be administered intracoronarily at 5 minutes prior to and at 5 minutes post-reperfusion, respectively, without aggravating MVO. Quantification of acute cell retention by polymerase chain reaction demonstrated that cell delivery prior to reperfusion resulted in higher cardiac cell retention compared to delivery post-reperfusion. We then performed a randomized, placebo-controlled study to assess the long-term efficacy of intracoronary infusion of 5 million allogeneic CDCs, delivered at 5 minutes prior to reperfusion, in a porcine model of AMI. The CDC therapy resulted in decreased scar size, improved regional systolic function, and attenuation of adverse cardiac remodeling (manifested as preserved global systolic function, preserved end-systolic volume, and decreased interstitial fibrosis) compared to placebo at 30 days post-MI. CONCLUSIONS: Dose-optimized intracoronary infusion of allogeneic CDCs prior to reperfusion in a porcine model of AMI is feasible, safe and confers long-term benefits.
Sr isotopes are a powerful tool used for provenancing in many disciplines, but their successful application requires the availability of robust Sr baselines of potential target areas. This study presents 87Sr/86Sr signatures and Sr concentrations of water, plants and soil leachates from the Peloponnese peninsula, Greece, to establish the first comprehensive bioavailable Sr isotope baseline for this region. Additionally, this study aims to evaluate which proxy is most suitable to characterise bioavailable Sr in a geologically complex area also exposed to foreign aeolian Sr sources. Our recorded bioavailable Sr isotope signatures correspond well with the surface lithologies characteristic of the Peloponnese. Unradiogenic 87Sr/86Sr ratios and a narrow isotope range (0.70779 - 0.70955) characterise the bioavailable Sr signatures of the sedimentary deposits and more radiogenic and isotopically variable values (0.70791 - 0.72370) were measured for metamorphic and igneous rock outcrops. The differences in 87Sr/86Sr values measured between proxies of one site are comparatively low for samples from the sedimentary and igneous deposits, while the overall spread in 87Sr/86Sr values is wider for samples from metamorphic deposits. We propose to define bioavailable 87Sr/86Sr baseline ranges as the average bioavailable 87Sr/86Sr ratio of all proxies of each lithology ± its double standard deviation (x̅ ± 2σ). This results in narrow baselines for the sedimentary outcrops of 0.70832 ± 0.00053 (n=58) for clastic sediments and 0.70835 ± 0.00089 (n=29) for chemical sediments. The metamorphic deposits are characterised by wider bioavailable 87Sr/86Sr baselines of 0.70906 ± 0.00116 (n=4) and 0.71429 ± 0.01133 (n=13) for marble and schist, respectively. The bioavailable Sr baseline for igneous rock outcrops is also characterised by a comparatively wide range with 0.70950 ± 0.00259 (n=7). The wide range in inter- and intra-site specific bioavailable 87Sr/86Sr variation observed in this study emphasise the need for comprehensive multi-proxy sampling strategies within geologically-complex areas.
Can controlled motivation contribute to desired educational outcomes such as academic achievement over and above autonomous motivation? No, According to Self-Determination Theory. Yet, some recent findings have shown that controlled motivation may not fully undermine motivated behavior when autonomous motivation remains high. In this study, we tested this possibility through two different samples of more than 3000 Turkish adolescent students. Through polynomial regression and response surface analyses we found only slim evidence that high controlled motivation can predict higher grades. Instead, a consistent finding that emerged was that higher grades were expected when high levels of autonomous motivation coincided with low levels of controlled motivation rather than high levels of controlled motivation. These findings highlight the usefulness of polynomial regressions and response surface analyses to examine pertinent questions which challenge the view that controlled motivation may not be as much detrimental as self-determination theory claims to be.
The island of Kalymnos, located in the Dodecanese island complex in the SE Aegean, is known for its sponge fishing but also for its world-famous climbing fields. Indeed, the island is considered the “Mecca” of climbers. Nevertheless, Kalymnos is characterized by moderate tourist traffic and lack of tourism infrastructure. The planning and development of geotourism can be a driving force for the economic sustainability of the island. In this study, the possibility of developing the innovative and alternative form of geotourism on the island of Kalymnos is explored. Kalymnos is characterized by numerous caves and steep slopes which can be geotopes attractive to visitors. Six caverns and two climbing fields were analyzed as part of our investigation. For the quantitative assessment of the geosites three factors are considered: the potential educational use (PEU), the potential touristic use (PTU), and the degradation risk (DR). The quantitative evaluation in combination with a SWOT analysis showed that there is indeed a possibility of promotion and development of geotourism in combination with the protection of the island’s geotopes. This will give additional impetus to the economy of Kalymnos. However, the lack of awareness from local authorities and residents is evident. The need for training in matters related to the geological heritage is necessary. In this way, there will be geotourism development, contributing positively to the economic prosperity and sustainability of the island.
In the Aegean region (Cyclades–Greece), a large part of the Island of Anafi consists of exhumed high-grade metamorphic sequences (amphibolites, serpentinites and metasediments) that have been intruded by Late Cretaceous intermediate and felsic granitoids. These correspond to I-type arc-related rocks, displaying calc-alkaline geochemical affinities. Variability in their petrographic features, mineral composition and geochemistry is assigned to differentiation processes that mostly involved plagioclase and/or K-feldspar, and to a lesser extent amphibole and biotite. Mineral chemistry and geochemical results suggest that the Anafi granitoids are highly comparable with the Late Cretaceous granitoid intrusive rocks from East Crete and Donousa island. The amphibole and zircon saturation thermometry yields relatively moderate temperature crystallization conditions ($\sim$790°C) for the intermediate granitoids and lower for the felsic granitoids ($\sim$630°C). Geobarometric calculations based upon the chemistry of magnesiohornblende, as well as the normative (Qz), (Ab) and (Or) contents clearly point to shallow intrusion conditions ($\sim$2.0–6.5 kbar), corresponding to an estimated depth of crystallization of $\sim$12 ± 4 km. The thrust sheets that overly the Palaeogene flysch in Anafi (metasediments with serpentinized peridotites, amphibolites and metabasites), constitute a subducted and metamorphosed oceanic sequence. These metamorphic units likely represent a part of the Pindos–Cycladic Blueschist Unit domain that was subducted at an earlier pre-Campanian stage. In the hydrated mantle wedge, incorporation of shallow level granitoids within metamorphic units was likely facilitated via corner flow intrusion mechanisms. Following the intrusion, the granitoid rocks were exhumed in a syn-convergent setting, along with the metamorphic thrust sheets, by continuous underplating of more external units, thus, escaping penetrative ductile deformation.
The Lavrion area corresponds to the western part of the Attic-Cycladic metamorphic belt, in the back-arc region of the active Hellenic subduction zone. Between the Eocene and the Miocene, metamorphic rocks (mainly marbles and schists) underwent several stages of metamorphism and deformation due to collision and collapse of the Cycladic belt. Exhumation during the Miocene was accommodated by the movement of a large-scale detachment fault system, which also enhanced emplacement of magmatic rocks, leading to the formation of the famous Lavrion silver deposits. The area around the mines shows the stacking of nappes, with ore deposition mainly localized within the marbles, at marble-schist contacts, below, within, or above the detachment. The Lavrion deposit comprises five genetically-related but different styles of mineralization, a feature never observed in another ore deposit elsewhere, containing the highest number of different elements of any known mining district. The local geology, tectonic, and magmatic activity were fundamental factors in determining how and when the mineralization formed. Other key factors, such as the rise and the fall of sea level, which resulted from climate change over the last million years, were also of major importance for the subsequent surface oxidation at Lavrion that created an unmatched diversity of secondary minerals. As a result, the Lavrion deposit contains 638 minerals of which Lavrion is type-locality for 23 of them, which is nearly 12% of all known species. Apart from being famous for its silver exploitation, this mining district contains more minerals than any other district on Earth.
Lavrion was an important silver mining district in the ancient world, exploited almost continuously from the fourth millennium BC. Its mining history is central to understanding the availability of silver, lead and copper in Greece and the Aegean through the Bronze age. This history is also relevant to the phenomenal rise of Athens in the 5th century BC. Our reassessment of the mineralisation and ancient mining history at Lavrion provides a clearer understanding of its capacity to generate wealth and the scale of its impact on Athens. Integration of new geochemical and geological data with existing information has produced outcomes that help address these two issues. Foremost is the contrasting character of mineralisation at the upper 'first' and lower 'third' contacts and their marked differences in silver content, spatial distribution and supergene alteration. Discovery of the concealed, bonanza mineralisation of the third contact at Kamariza, possibly early in the 5th century BC, followed about 3000 years of mining, which appears to have been largely restricted to discontinuous, low-grade mineralisation at the first contact. Undoubtedly, this later discovery had enduring impacts on Lavrion and Athens, and it most likely funded the trireme fleet, which brought victory over the Persians at Salamis in 480 BC.
To describe the molecular electronic structure of nucleic acid bases and other heterocycles, we employ the Linear Combination of Atomic Orbitals (LCAO) method, considering the molecular wave function as a linear combination of all valence orbitals, i.e., 2s, 2px, 2py, 2pz orbitals for C, N, and O atoms and 1s orbital for H atoms. Regarding the diagonal matrix elements (also known as on-site energies), we introduce a novel parameterization. For the non-diagonal matrix elements referring to neighboring atoms, we employ the Slater–Koster two-center interaction transfer integrals. We use Harrison-type expressions with factors slightly modified relative to the original. We compare our LCAO predictions for the ionization and excitation energies of heterocycles with those obtained from Ionization Potential Equation of Motion Coupled Cluster with Singles and Doubles (IP-EOMCCSD)/aug-cc-pVDZ level of theory and Completely Normalized Equation of Motion Coupled Cluster with Singles, Doubles, and non-iterative Triples (CR-EOMCCSD(T))/aug-cc-pVDZ level of theory, respectively, (vertical values), as well as with available experimental data. Similarly, we calculate the transfer integrals between subsequent base pairs, to be used for a Tight-Binding (TB) wire model description of charge transfer and transport along ideal or deformed B-DNA. Taking into account all valence orbitals, we are in the position to treat deflection from the planar geometry, e.g., DNA structural variability, a task impossible for the plane Hückel approach (i.e., using only 2pz orbitals). We show the effects of structural deformations utilizing a 20mer evolved by Molecular Dynamics.
A rigorous time Floquet method for the calculation of scattering of electromagnetic waves by a homogeneous spherical object, characterized by a periodically varying-in-time isotropic permittivity, is presented. The method is applied to the study of Mie scattering by such a modulated dielectric particle. Our results are in excellent agreement with the quasistatic adiabatic approximation in the slow-modulation limit. At higher modulation frequencies, a remarkable spectral response, including resonant inelastic scattering and frequency conversion as well as energy transfer between the dynamic sphere and the electromagnetic field, is revealed and consistently explained.
Abstract
Contrary to Keynes’ and Duesenberry’s consumption theories, absolute or relative income plays a minimal role in the life-cycle and in the permanent-income hypotheses. It plays an even lesser role in contemporary orthodox consumption functions which are extensions of these two theories in a rational-expectations framework. As a result, the theoretical effectiveness of fiscal policy for raising output is greatly diminished. The paper argues that Keynes’ and Duesenberry’s approaches were marginalised not because of their empirical or theoretical shortcomings, but because of emphasising the psychological and social influences on consumption patterns, and because of not employing the intertemporal utility maximising framework.
A small fraction of gamma-ray bursts (GRBs) with available data down to soft X-rays (~0.5 keV) has been shown to feature a spectral break in the low-energy part (~1-10 keV) of their prompt emission spectrum. The overall spectral shape is consistent with optically thin synchrotron emission from a population of particles that have cooled on a time-scale comparable to the dynamic time to energies that are still much higher than their rest-mass energy (marginally fast cooling regime). We consider a hadronic scenario and investigate if the prompt emission of these GRBs can originate from relativistic protons that radiate synchrotron in the marginally fast cooling regime. Using semi-analytical methods, we derive the source parameters, such as magnetic field strength and proton luminosity, and calculate the high-energy neutrino emission expected in this scenario. We also investigate how the emission of secondary pairs produced by photopion interactions and γγ pair production affect the broad-band photon spectrum. We support our findings with detailed numerical calculations. Strong modification of the photon spectrum below the break energy due to the synchrotron emission of secondary pairs is found, unless the bulk Lorentz factor is very large (Γ ≳ 103). Moreover, this scenario predicts unreasonably high Poynting luminosities because of the strong magnetic fields (106-107 G) that are necessary for the incomplete proton cooling. Our results strongly disfavour marginally fast cooling protons as an explanation of the low-energy spectral break in the prompt GRB spectra.
In the current paper we give a persistent effort to emphasize on the clear present threat posed by Turkey’s Neo-Ottoman Islamic and revisionist role for the Geopolitical Complex of (Middle-East / Balkans / Caucasus).Furthermore, we try and make it abundantly clear that any abandonment of the Greece-Cyprus dipole of Hellenism, which is staunchly protecting Western interests over and across three continents and with such interests firmly grounded on the principles of the civil, pluralistic, European Democracy and Civilization, will deliver the most significant blow to these very Western Interests. A blow, which in fact is using as its “stabbing knife” Islamist Turkey, which has submitted and succumbed to the Organization of the “Muslim Brotherhood”, as well as to the fascist Turkish group of the “Grey Wolves”, two groups which they are both off-springs of International Fascism, work in perfect harmony together.
BACKGROUND: Multiple myeloma bone disease (MMBD) constitutes a common and severe complication of multiple myeloma (MM), impacting the quality of life and survival. We evaluated the clinical value of a panel of 19 miRNAs associated with osteoporosis in MMBD. METHODS: miRNAs were isolated from the plasma of 62 newly diagnosed MM patients with or without MMBD. First-strand cDNA was synthesized, and relative quantification was performed using qPCR. Lastly, we carried out extensive biostatistical analysis. RESULTS: Circulating levels of let-7b-5p, miR-143-3p, miR-17-5p, miR-214-3p, and miR-335-5p were significantly higher in the blood plasma of MM patients with MMBD compared to those without. Receiver operating characteristic curve and logistic regression analyses showed that these miRNAs could accurately predict MMBD. Furthermore, a standalone multi-miRNA-based logistic regression model exhibited the best predictive potential regarding MMBD. Two of those miRNAs also have a prognostic role in MM since survival analysis indicated that lower circulating levels of both let-7b-5p and miR-335-5p were associated with significantly worse progression-free survival, independently of the established prognostic factors. CONCLUSIONS: Our study proposes a miRNA signature to facilitate MMBD diagnosis, especially in ambiguous cases. Moreover, we provide evidence of the prognostic role of let-7b-5p and miR-335-5p as non-invasive prognostic biomarkers in MM.
This work investigates and compares nominal expressive suffixes in Russian and Greek within the framework of Distributed Morphology. It shows that, although the suffixes under investigation share the same expressive meaning, they differ significantly in their syntactic structure, namely in the manner and place of attachment in the syntactic tree. More specifically, in both languages expressive suffixes can attach either as heads or as modifiers and, furthermore, they may occupy various syntactic positions. This illustrates that, despite their uniformity at semantic level, expressive suffixes exhibit variation with respect to their syntactic structuring both within and across languages.
We report the experimental realization of a multifunctional microscale plasmonic metasurface capable of sampling a light beam and performing five functionalities, while allowing high direct transmission and maintenance of the properties of the input light beam. The plasmonic metasurface integrates light-to-surface-plasmon coupling, two-channel wavelength demultiplexing with a channel spacing smaller than 44 nm, wavelength and polarization controllable beam splitting of a monochromatic, single polarization signal, and four-level polarization and wavelength-polarization demultiplexing in an all-in-one structure. Such a device can play a key role for on-chip adaptable integrated circuits for parallel signal processing, communications, and nondestructive sensing.
This paper introduces a 3-layer feed-forward neuronet model, trained by novel beetle antennae search weights-and-structure-determination (BASWASD) algorithm. On the one hand, the beetle antennae search (BAS) algorithm is a memetic meta-heuristic optimization algorithm capable of solving combinatorial optimization problems. On the other hand, neuronets trained by a weights-and-structure-determination (WASD) algorithm are known to resolve the shortcomings of traditional back-propagation neuronets, including slow speed of training and local minimum. Combining the BAS and WASD algorithms, a novel BASWASD algorithm is created for training neuronets, and a multi-input BASWASD neuronet (MI-BASWASDN) model is introduced. Using a power sigmoid activation function and while managing the model fitting and validation, the BASWASD algorithm finds the optimal weights and structure of the MI-BASWASDN. Four financial datasets, taken from the European Central Bank publications, validate and demonstrate the MI-BASWASDN model’s outstanding learning and predicting performance. Also included is a comparison of the MI-BASWASDN model to three other well-performing neural network models, as well as a MATLAB kit that is publicly available on GitHub to promote and support this research.
On July 30th, 2019 IceCube detected a high-energy astrophysical muon neutrino candidate, IC-190730A with a 67% probability of astrophysical origin. The flat spectrum radio quasar (FSRQ) PKS 1502 +106 is in the error circle of the neutrino. Motivated by this observation, we study PKS 1502+106 as a possible source of IC-190730A. PKS 1502+106 was in a quiet state in terms of UV/optical/X-ray/γ-ray flux at the time of the neutrino alert, we therefore model the expected neutrino emission from the source during its average long-term state, and investigate whether the emission of IC-190730A as a result of the quiet long-term emission of PKS 1502+106 is plausible. We analyse UV/optical and X-ray data and collect additional observations from the literature to construct the multi-wavelength spectral energy distribution of PKS 1502+106. We perform leptohadronic modelling of the multi-wavelength emission of the source and determine the most plausible emission scenarios and the maximum expected accompanying neutrino flux. A model in which the multi-wavelength emission of PKS 1502+106 originates beyond the broad-line region and inside the dust torus is most consistent with the observations. In this scenario, PKS 1502+106 can have produced up to of order one muon neutrino with energy exceeding 100 TeV in the lifetime of IceCube. An appealing feature of this model is that the required proton luminosity is consistent with the average required proton luminosity if blazars power the observed ultra-high-energy-cosmic-ray flux and well below the source's Eddington luminosity. If such a model is ubiquitous among FSRQs, additional neutrinos can be expected from other bright sources with energy ≳ 10 PeV.
In some islands of the Aegean, there is evidence of the occurrence of repeated rapid subsidences during the Late Holocene. In this paper, the shape of tidal notches that may be well-preserved underwater is recalled in order to reconstruct sequences of coseismic subsidences and other relative sea-level changes, which occurred during, at least, the last few millennia. A reanalysis of the published measurements of submerged tidal notches in several islands reveals that subsidence trends in many areas of the Aegean are not continuous with gradual movement but, also, are the result of repeated coseismic vertical subsidences of some decimetres at each time. The estimated average return times are of the order of approximately some centuries to one millennium. Although the results cannot be used for short-term predictions of earthquakes, they may provide useful indications on the long-term tectonic trends that are active in the Aegean region.
Cite as: Kefi-Chatzichamperi, E., & Kamberidou, I. (2021). THE NATIONAL ACTION PLAN FOR GENDER EQUALITY: WOMEN, SPORTS AND MILITARY INSTITUTIONS. European Journal of Physical Education and Sport Science, 7(3). doi:http://dx.doi.org/10.46827/ejpe.v7i3.3959
Long duration gamma-ray bursts (GRBs) are among the least understood astrophysical transients powering the high-energy universe. To date, various mechanisms have been proposed to explain the observed electromagnetic GRB emission. In this work, we show that, although different jet models may be equally successful in fitting the observed electromagnetic spectral energy distributions, the neutrino production strongly depends on the adopted emission and dissipation model. To this purpose, we compute the neutrino production for a benchmark high-luminosity GRB in the internal shock model, including a dissipative photosphere as well as three emission components, in the jet model invoking internal-collision-induced magnetic reconnection and turbulence (ICMART), in the case of a magnetic jet with gradual dissipation, and in a jet with dominant proton synchrotron radiation. We find that the expected neutrino fluence can vary up to three orders of magnitude in amplitude and peak at energies ranging from 104 to 108 GeV. For our benchmark input parameters, none of the explored GRB models is excluded by the targeted searches carried out by the IceCube and ANTARES Collaborations. However, our work highlights the potential of high-energy neutrinos of pinpointing the underlying GRB emission mechanism and the importance of relying on different jet models for unbiased stacking searches.
The environment in which the decision-making process takes place is often characterized by uncertainty and vagueness and, because of that, sometimes it is very hard to express the criteria weights with crisp numbers. Therefore, the application of the Grey System Theory, i.e., grey numbers, in this case, is very convenient when it comes to determination of the criteria weights with partially known information. Besides, the criteria weights have a significant role in the multiple criteria decision-making process. Many ordinary multiple criteria decision-making methods are adapted for using grey numbers, and this is the case in this article as well. A new grey extension of the certain multiple criteria decision-making methods for the determination of the criteria weights is proposed. Therefore, the article aims to propose a new extension of the Step-wise Weight Assessment Ratio Analysis (SWARA) and PIvot Pairwise Relative Criteria Importance Assessment (PIPRECIA) methods adapted for group decision-making. In the proposed approach, attitudes of decision-makers are transformed into grey group attitudes, which allows taking advantage of the benefit that grey numbers provide over crisp numbers. The main advantage of the proposed approach in relation to the use of crisp numbers is the ability to conduct different analyses, i.e., considering different scenarios, such as pessimistic, optimistic, and so on. By varying the value of the whitening coefficient, different weights of the criteria can be obtained, and it should be emphasized that this approach gives the same weights as in the case of crisp numbers when the whitening coefficient has a value of 0.5. In addition, in this approach, the grey number was formed based on the median value of collected responses because it better maintains the deviation from the normal distribution of the collected responses. The application of the proposed approach was considered through two numerical illustrations, based on which appropriate conclusions were drawn.
We study magnon-mediated optical transitions in micrometer-sized axially symmetric yttrium iron garnet (YIG) particles, which act as optomagnonic cavities, by means of electromagnetic calculations, treating the magneto-optical coupling to first order in perturbation theory, in the framework of a fully dynamic approach. Such particles with engineered shape anisotropy exhibit high-quality-factor Mie resonances in the infrared part of the spectrum, with a separation of few gigahertz, which matches the typical frequencies of magnons. This allows for optical transitions mediated by spin waves, while the micrometer volume favors stronger overlap between the optical modes and the precessing magnetization. Our results predict that photon-magnon coupling strengths of tens of kilohertz could be realized with cylindrical or spheroidal particles, since mainly the reduced volume, but also shape anisotropy, can lead to strong, up to four orders of magnitude, enhancement of the coupling strengths compared to submillimeter YIG spheres.
Abstract. This study discusses the problem of the incompatibility between ethnocentric tendencies within the national Orthodox churches and the New Testament teaching on nonviolence. The three main parts outline the relevant New Testament teaching (1) in the four Gospels and the book of Acts, (2) in the Pauline epistles, and (3) in John’s Revelation. The study concludes that in the New Testament texts, there is no room for the justification of violence on the part of Christ-followers against their opponents. Quite on the contrary, the New Testament views the world as having the potential to become ecclesia, and the “other” as a possible sister or brother in Christ. Unfortunately, this fundamental New Testament teaching is often forgotten in modern-day Orthodoxy, notwithstanding its claims for unbroken continuity with the apostolic tradition. As an example, the Greek-Orthodox church oftentimes emphasizes national identity and heroism over ecclesial faith and ethos. Although understandable, such ethnocentric tendencies clearly contradict the New Testament witness and should be abandoned.
Considering the lack of effective treatments against COVID-19, wastewater-based epidemiology (WBE) is emerging as a cost-effective approach for real-time population-wide SARS-CoV-2 monitoring. Here, we report novel molecular assays for sensitive detection and mutational/variant analysis of SARS-CoV-2 in wastewater. Highly stable regions of SARS-CoV-2 RNA were identified by RNA stability analysis and targeted for the development of novel nested PCR assays. Targeted DNA sequencing (DNA-seq) was applied for the analysis and quantification of SARS-CoV-2 mutations/variants, following hexamers-based reverse transcription and nested PCR-based amplification of targeted regions. Three-dimensional (3D) structure models were generated to examine the predicted structural modification caused by genomic variants. WBE of SARS-CoV-2 revealed to be assay dependent, and significantly improved sensitivity achieved by assay combination (94%) vs. single-assay screening (30%-60%). Targeted DNA-seq allowed the quantification of SARS-CoV-2 mutations/variants in wastewater, which agreed with COVID-19 patients' sequencing data. A mutational analysis indicated the prevalence of D614G (S) and P323L (RdRP) variants, as well as of the Beta.1.1.7/alpha variant of concern, in agreement with the frequency of Beta.1.1.7/alpha variant in clinical samples of the same period of the third pandemic wave at the national level. Our assays provide an innovative cost-effective platform for real-time monitoring and early-identification of SARS-CoV-2 variants at community/population levels.
The hippocampus-prefrontal cortex circuit plays a major role in stress and in the neurobiology of depression and its treatment. Disruption of this circuit by lesioning the thalamic nucleus reuniens (RE) has been shown to prevent the detrimental effects of chronic mild stress on prefrontal cortex neuroplasticity indices in male rats. However, it remains unknown whether hippocampal neurostructural response to stress is modified by RE lesion. In the present study, adult male rats were subjected to the chronic mild stress model of depression and were treated with either vehicle or an antidepressant (i.e. sertraline). Moreover, a group of animals was subjected to RE lesion before stress exposure with or without sertraline treatment. We demonstrated that chronic mild stress induced hippocampal CA1 dendritic atrophy and this was prevented by pre-stress RE lesion to the same extent that antidepressant treatment reversed it. The present findings highlight the importance of hippocampal-prefrontal cortex communication in chronic stress effects on hippocampal neuroplasticity and contribute to the elucidation of the role of RE in neurostructural changes underlying stress-driven depression and its treatment.
Decade-long monitoring of blazars at optical and infrared (OIR) wavelengths with the Small and Moderate Aperture Research Telescope System (SMARTS) in Chile and in γ-rays with the Fermi -Large Area Telescope (LAT) has enabled the systematic study of their multiwavelength long-term variability. In this work, we investigate, from a theoretical perspective, the long-term variability properties of blazar emission by introducing an observationally motivated time-dependence to four main parameters of the one-zone leptonic model: injection luminosity of relativistic electrons, strength of magnetic field, Doppler factor, and external photon field luminosity. For the first time, we use both the probability density function and the power spectral density of the 10-yr-long Fermi-LAT light curves to create variation patterns for the model parameters. Using as test beds two bright blazars from the SMARTS sample (PKS 2155-304 and 3C 273), we compute 10-yr-long OIR, X-ray, and γ-ray model light curves for different varying parameters. We compare the findings of our theoretical investigation with multiwavelength observations using various measures of variability. While no single-varying parameter simulation can explain all multiwavelength variability properties, changes in the electron luminosity and external radiation field in PKS 2155-304 and 3C 273, respectively, can account for most of them. Our results motivate future time-dependent studies with coupling between two or more physical parameters to describe the multiwavelength long-term blazar variability.