33 research outputs found
Theoretical backgrounds of nonlinear THz spectroscopy of semiconductor superlattices
We consider terahertz absorption and gain in a single miniband of
semiconductor superlattice subject to a bichromatic electric field in the most
general case of commensurate frequencies of the probe and pump fields. Using an
exact solution of Boltzmann transport equation, we show that in the
small-signal limit the formulas for absorption always contain two distinct
terms related to the parametric and incoherent interactions of miniband
electrons with the alternating pump field. It provides a theoretical background
for a control of THz gain without switching to the negative differential
conductivity state. For pedagogical reasons we present derivations of formulas
in detail.Comment: 14 page
INTERACTIONS BETWEEN ANXIETY LEVELS AND LIFE HABITS CHANGES IN GENERAL POPULATION DURING THE PANDEMIC LOCKDOWN: DECREASED PHYSICAL ACTIVITY, FALLING ASLEEP LATE AND INTERNET BROWSING ABOUT COVID-19 ARE RISK FACTORS FOR ANXIETY, WHEREAS SOCIAL MEDIA USE IS NOT
Background. The COVID-19 pandemic has substantially contributed to increased anxiety rates among the general population
worldwide. Pandemic-related health anxiety and worries about getting COVID-19 can lead to generalized anxiety and anxiety
somatization, which, together with insalubrious daily life habits, are risk factors of worsening somatic health in people with
SARS-Cov-2 infection.
Subjects and methods: The current study is a part of the COMET-G project (40 countries, n=55589; approved by the Ethics
Committee of the Aristotle University of Thessaloniki), which represents an intermediate analysis of data collected anonymously via
online links from a national sample of the Russian general population (n=9936, 31.09±12.16 y.o., 58.7% females) to estimate anxiety
using STAI-S and self-reported changes in anxiety and life habits (physical activity, nutrition and weight, internet use, sleep) during
the lockdown. All statistical calculations (descriptive statistics, between group comparisons using chi-square test, MANOVA,
ANOVA, significant at p<0.05) were performed with IBM SPSS 27.
Results: Overall STAI-S scores were 29+- 5.4, a subjective feeling of anxiety increase was reported in 40.3% of respondents (43.9%
significantly > in females), worsening to clinical anxiety in 2.1% (2.4% > in females). 54.2% of respondents reported decreased
physical activity, 33.1% gained weight, 72% used internet more often, 52.6% experienced worries related to the information about
COVID-19 (56.8% > in females). 88% experienced worsened sleep quality, 69.2% stayed up until late, 23.2% took sleeping pills,
and 31% had nightmares in which they felt trapped. To ANOVA, such life habits as reduced physical activity during the lockdown,
increased time spent online, internet browsing about COVID-19, tendency to stay up late, use of sleeping pills and disturbing dreams
with scenario of being trapped were significantly related to worsening of clinical anxiety. However, eating behaviour, weight
changes, and social media use did not contribute to the clinical anxiety increase.
Conclusions: Factors of decreased physical activity and sleep disturbances related to the lockdown, as well as excessive internet
browsing for information about COVID-19, emerged as risk factors for increased anxiety, more notably in women than in men.
Preventive measures should be targeted against relevant factors imparting anxiety in the vulnerable population
INTERACTIONS BETWEEN ANXIETY LEVELS AND LIFE HABITS CHANGES IN GENERAL POPULATION DURING THE PANDEMIC LOCKDOWN: DECREASED PHYSICAL ACTIVITY, FALLING ASLEEP LATE AND INTERNET BROWSING ABOUT COVID-19 ARE RISK FACTORS FOR ANXIETY, WHEREAS SOCIAL MEDIA USE IS NOT
Background. The COVID-19 pandemic has substantially contributed to increased anxiety rates among the general population
worldwide. Pandemic-related health anxiety and worries about getting COVID-19 can lead to generalized anxiety and anxiety
somatization, which, together with insalubrious daily life habits, are risk factors of worsening somatic health in people with
SARS-Cov-2 infection.
Subjects and methods: The current study is a part of the COMET-G project (40 countries, n=55589; approved by the Ethics
Committee of the Aristotle University of Thessaloniki), which represents an intermediate analysis of data collected anonymously via
online links from a national sample of the Russian general population (n=9936, 31.09±12.16 y.o., 58.7% females) to estimate anxiety
using STAI-S and self-reported changes in anxiety and life habits (physical activity, nutrition and weight, internet use, sleep) during
the lockdown. All statistical calculations (descriptive statistics, between group comparisons using chi-square test, MANOVA,
ANOVA, significant at p<0.05) were performed with IBM SPSS 27.
Results: Overall STAI-S scores were 29+- 5.4, a subjective feeling of anxiety increase was reported in 40.3% of respondents (43.9%
significantly > in females), worsening to clinical anxiety in 2.1% (2.4% > in females). 54.2% of respondents reported decreased
physical activity, 33.1% gained weight, 72% used internet more often, 52.6% experienced worries related to the information about
COVID-19 (56.8% > in females). 88% experienced worsened sleep quality, 69.2% stayed up until late, 23.2% took sleeping pills,
and 31% had nightmares in which they felt trapped. To ANOVA, such life habits as reduced physical activity during the lockdown,
increased time spent online, internet browsing about COVID-19, tendency to stay up late, use of sleeping pills and disturbing dreams
with scenario of being trapped were significantly related to worsening of clinical anxiety. However, eating behaviour, weight
changes, and social media use did not contribute to the clinical anxiety increase.
Conclusions: Factors of decreased physical activity and sleep disturbances related to the lockdown, as well as excessive internet
browsing for information about COVID-19, emerged as risk factors for increased anxiety, more notably in women than in men.
Preventive measures should be targeted against relevant factors imparting anxiety in the vulnerable population
New Synthetic Thrombin Inhibitors: Molecular Design and Experimental Verification
BACKGROUND: The development of new anticoagulants is an important goal for the improvement of thromboses treatments. OBJECTIVES: The design, synthesis and experimental testing of new safe and effective small molecule direct thrombin inhibitors for intravenous administration. METHODS: Computer-aided molecular design of new thrombin inhibitors was performed using our original docking program SOL, which is based on the genetic algorithm of global energy minimization in the framework of a Merck Molecular Force Field. This program takes into account the effects of solvent. The designed molecules with the best scoring functions (calculated binding energies) were synthesized and their thrombin inhibitory activity evaluated experimentally in vitro using a chromogenic substrate in a buffer system and using a thrombin generation test in isolated plasma and in vivo using the newly developed model of hemodilution-induced hypercoagulation in rats. The acute toxicities of the most promising new thrombin inhibitors were evaluated in mice, and their stabilities in aqueous solutions were measured. RESULTS: New compounds that are both effective direct thrombin inhibitors (the best K(I) was <1 nM) and strong anticoagulants in plasma (an IC(50) in the thrombin generation assay of approximately 100 nM) were discovered. These compounds contain one of the following new residues as the basic fragment: isothiuronium, 4-aminopyridinium, or 2-aminothiazolinium. LD(50) values for the best new inhibitors ranged from 166.7 to >1111.1 mg/kg. A plasma-substituting solution supplemented with one of the new inhibitors prevented hypercoagulation in the rat model of hemodilution-induced hypercoagulation. Activities of the best new inhibitors in physiological saline (1 µM solutions) were stable after sterilization by autoclaving, and the inhibitors remained stable at long-term storage over more than 1.5 years at room temperature and at 4°C. CONCLUSIONS: The high efficacy, stability and low acute toxicity reveal that the inhibitors that were developed may be promising for potential medical applications
Dissecting selective signatures and candidate genes in grandparent lines subject to high selection pressure for broiler production and in a local Russian chicken breed of Ushanka
Breeding improvements and quantitative trait genetics are essential to the advancement of broiler production. The impact of artificial selection on genomic architecture and the genetic markers sought remains a key area of research. Here, we used whole-genome resequencing data to analyze the genomic architecture, diversity, and selective sweeps in Cornish White (CRW) and Plymouth Rock White (PRW) transboundary breeds selected for meat production and, comparatively, in an aboriginal Russian breed of Ushanka (USH). Reads were aligned to the reference genome bGalGal1.mat.broiler.GRCg7b and filtered to remove PCR duplicates and low-quality reads using BWA-MEM2 and bcftools software; 12,563,892 SNPs were produced for subsequent analyses. Compared to CRW and PRW, USH had a lower diversity and a higher genetic distinctiveness. Selective sweep regions and corresponding candidate genes were examined based on ZFST, hapFLK, and ROH assessment procedures. Twenty-seven prioritized chicken genes and the functional projection from human homologs suggest their importance for selection signals in the studied breeds. These genes have a functional relationship with such trait categories as body weight, muscles, fat metabolism and deposition, reproduction, etc., mainly aligned with the QTLs in the sweep regions. This information is pivotal for further executing genomic selection to enhance phenotypic traits
Students' mental health during the pandemic:results of the observational cross-sectional COVID-19 MEntal health inTernational for university Students (COMET-S) study
Introduction: The aim of the study was to search rates of depression and mental health in university students, during the COVID-19 pandemic. Materials and methods: This is an observational cross-sectional study. A protocol gathering sociodemographic variables as well as depression, anxiety and suicidality and conspiracism was assembled, and data were collected anonymously and online from April 2020 through March 2021. The sample included 12,488 subjects from 11 countries, of whom 9,026 were females (72.2%; aged 21.11 ± 2.53), 3,329 males (26.65%; aged 21.61 ± 2.81) and 133 “non-binary gender” (1.06%; aged 21.02 ± 2.98). The analysis included chi-square tests, correlation analysis, ANCOVA, multiple forward stepwise linear regression analysis and Relative Risk ratios. Results: Dysphoria was present in 15.66% and probable depression in 25.81% of the total study sample. More than half reported increase in anxiety and depression and 6.34% in suicidality, while lifestyle changes were significant. The model developed explained 18.4% of the development of depression. Believing in conspiracy theories manifested a complex effect. Close to 25% was believing that the vaccines include a chip and almost 40% suggested that facemask wearing could be a method of socio-political control. Conspiracism was related to current depression but not to history of mental disorders. Discussion: The current study reports that students are at high risk for depression during the COVID-19 pandemic and identified specific risk factors. It also suggested a role of believing in conspiracy theories. Further research is important, as it is targeted intervention in students' groups that are vulnerable both concerning mental health and conspiracism
GABB : A global dataset of alpine breeding birds and their ecological traits
Alpine ecosystems represent varied climates and vegetation structures globally, with the potential to support rich and functionally diverse avian communities. High mountain habitats and species are under significant threat from climate change and other anthropogenic factors. Yet, no global database of alpine birds exists, with most mountain systems lacking basic information on species breeding in alpine habitats, their status and trends, or potential cryptic diversity (i.e., sub-species distributions). To address these critical knowledge gaps, we combined published literature, regional monitoring schemes, and expert knowledge from often inaccessible, data-deficient mountain ranges to develop a global list of alpine breeding bird species with their associated distributions and select ecological traits. This dataset compiles alpine breeding records for 1,310 birds, representing 12.0% of extant species and covering all major mountain regions across each continent, excluding Antarctica. The Global Alpine Breeding Bird dataset (GABB) is an essential resource for research on the ecological and evolutionary factors shaping alpine communities, as well as documenting the value of these high elevation, climate-sensitive habitats for conserving biodiversity.Peer reviewe
Genome-wide association study revealed putative SNPs and candidate genes associated with growth and meat traits in Japanese quail
The search for SNPs and candidate genes that determine the manifestation of major selected traits is one crucial objective for genomic selection aimed at increasing poultry production efficiency. Here, we report a genome-wide association study (GWAS) for traits characterizing meat performance in the domestic quail. A total of 146 males from an F 2 reference population resulting from crossing a fast (Japanese) and a slow (Texas White) growing breed were examined. Using the genotyping-by-sequencing technique, genomic data were obtained for 115,743 SNPs (92,618 SNPs after quality control) that were employed in this GWAS. The results identified significant SNPs associated with the following traits at 8 weeks of age: body weight (nine SNPs), daily body weight gain (eight SNPs), dressed weight (33 SNPs), and weights of breast (18 SNPs), thigh (eight SNPs), and drumstick (three SNPs). Also, 12 SNPs and five candidate genes (GNAL, DNAJC6, LEPR, SPAG9, and SLC27A4) shared associations with three or more traits. These findings are consistent with the understanding of the genetic complexity of body weight-related traits in quail. The identified SNPs and genes can be used in effective quail breeding as molecular genetic markers for growth and meat characteristics for the purpose of genetic improvement
Genotyping-by-sequencing strategy for integrating genomic structure, diversity and performance of various Japanese quail (Coturnix japonica) breeds
Simple Summary:
Artificial selection has been applied to domesticated birds for many decades. More recently, this selection has made use of so-called single-nucleotide polymorphism (SNP) markers—simple variants in a DNA sequence. These SNPs can be used for whole-genome screening to detect the unique traces of areas of the genome that are subject to selection. Doing this may help to shed light on the evolutionary and family history (phylogeny) of domestic Japanese quails of different breeds and utility types (e.g., egg, meat or dual-purpose breeds). In this study, 99 birds were used, representing eight breeds (11% of the world’s quail gene pool) and various purposes of use to gather genetic (whole-genome) data in the first-ever analysis of its kind performed on domestic quails. We thereby uncovered evolutionary relationships and points of divergence of individual quail breeds, gleaning important insights into the genetic diversity of domestic quail breeds and their future breeding potential.
Abstract:
Traces of long-term artificial selection can be detected in genomes of domesticated birds via whole-genome screening using single-nucleotide polymorphism (SNP) markers. This study thus examined putative genomic regions under selection that are relevant to the development history, divergence and phylogeny among Japanese quails of various breeds and utility types. We sampled 99 birds from eight breeds (11% of the global gene pool) of egg (Japanese, English White, English Black, Tuxedo and Manchurian Golden), meat (Texas White and Pharaoh) and dual-purpose (Estonian) types. The genotyping-by-sequencing analysis was performed for the first time in domestic quails, providing 62,935 SNPs. Using principal component analysis, Neighbor-Net and Admixture algorithms, the studied breeds were characterized according to their genomic architecture, ancestry and direction of selective breeding. Japanese and Pharaoh breeds had the smallest number and length of homozygous segments indicating a lower selective pressure. Tuxedo and Texas White breeds showed the highest values of these indicators and genomic inbreeding suggesting a greater homozygosity. We revealed evidence for the integration of genomic and performance data, and our findings are applicable for elucidating the history of creation and genomic variability in quail breeds that, in turn, will be useful for future breeding improvement strategies
The significance of cephalopod beaks as a research tool: An update
The use of cephalopod beaks in ecological and population dynamics studies has allowed major advances of our knowledge on the role of cephalopods in marine ecosystems in the last 60 years. Since the 1960's, with the pioneering research by Malcolm Clarke and colleagues, cephalopod beaks (also named jaws or mandibles) have been described to species level and their measurements have been shown to be related to cephalopod body size and mass, which permitted important information to be obtained on numerous biological and ecological aspects of cephalopods in marine ecosystems. In the last decade, a range of new techniques has been applied to cephalopod beaks, permitting new kinds of insight into cephalopod biology and ecology. The workshop on cephalopod beaks of the Cephalopod International Advisory Council Conference (Sesimbra, Portugal) in 2022 aimed to review the most recent scientific developments in this field and to identify future challenges, particularly in relation to taxonomy, age, growth, chemical composition (i.e., DNA, proteomics, stable isotopes, trace elements) and physical (i.e., structural) analyses. In terms of taxonomy, new techniques (e.g., 3D geometric morphometrics) for identifying cephalopods from their beaks are being developed with promising results, although the need for experts and reference collections of cephalopod beaks will continue. The use of beak microstructure for age and growth studies has been validated. Stable isotope analyses on beaks have proven to be an excellent technique to get valuable information on the ecology of cephalopods (namely habitat and trophic position). Trace element analyses is also possible using beaks, where concentrations are significantly lower than in other tissues (e.g., muscle, digestive gland, gills). Extracting DNA from beaks was only possible in one study so far. Protein analyses can also be made using cephalopod beaks. Future challenges in research using cephalopod beaks are also discussed.info:eu-repo/semantics/publishedVersio