Optical and EPR spectroscopy of Er3+ in lithium yttrium borate, Li6Y(BO3)3:Er single crystals

The energy levels of Er3+ ions have been determined in lithium yttrium borate (Li6Y(BO3)3) single crystals in a wide spectral range between 6000 and 40000 cm-1 together with an analysis of the ground state, using optical and EPR spectroscopy. The crystal field splittings of the 4I15/2 ground state and those of nearly all excited states up to the 4D7/2 manifold have been obtained at low temperature from luminescence (T = 5 K) and absorption (T = 9 K) measurements, respectively. The numbers of experimentally observed Stark sublevels agree well with those expected theoretically for Er3+ ions occupying a single low symmetry (C1) site. A full set of g- and 167Er hyperfine tensor parameters are presented for the ground state characterized by EPR; the measured Orbach-type spin-relaxation rates viz. the involved activation energies correspond to the optically derived lowest excited sublevels

Подростки-спортсмены строят двойную карьеру и благополучие в условиях двойного карьерного роста: роль факторов окружающей среды

Рукопись поступила в редакцию: 20.12.2021.Received: 20.12.2021.Цель исследования заключалась в изучении карьерного роста и благополучия спортсменов-подростков в условиях двойного карьерного роста. В исследовании выявлены особенности адаптивности к карьере в старших классах спортивной школы. В статье представлены данные относительно того, в какой степени самооценка и пол связаны с адаптивностью к двойной карьере, определены профили адаптации к карьере спортсменов-подростков, выявлены как ожидания студентов-спортсменов в зависимости от их успехов в спорте и учебе и соответствующие ожидания их родителей связаны с их профилями адаптации к карьере. Получены новые данные относительно того, как организационная культура спортивной школы влияет на построение карьеры спортсменов-подростков.The purpose of the scientific research was to study the career growth and well-being of adolescent athletes in conditions of dual career growth. The study revealed the features of adaptability to a career in high school of sports school. The article presents data on the extent to which self-esteem and gender are associated with adaptability to a dual career, the profiles of adaptation to the career of adolescent athletes have been defined, it is also revealed how the expectations of student-athletes depending on their success in sports and studies and the corresponding expectations of their parents are associated with their profiles of adaptation to a career. The new data on how the organizational culture of a sports school affects the career development of teenage athletes have been obtained

Replication Timing: A Fingerprint for Cell Identity and Pluripotency

Many types of epigenetic profiling have been used to classify stem cells, stages of cellular differentiation, and cancer subtypes. Existing methods focus on local chromatin features such as DNA methylation and histone modifications that require extensive analysis for genome-wide coverage. Replication timing has emerged as a highly stable cell type-specific epigenetic feature that is regulated at the megabase-level and is easily and comprehensively analyzed genome-wide. Here, we describe a cell classification method using 67 individual replication profiles from 34 mouse and human cell lines and stem cell-derived tissues, including new data for mesendoderm, definitive endoderm, mesoderm and smooth muscle. Using a Monte-Carlo approach for selecting features of replication profiles conserved in each cell type, we identify “replication timing fingerprints” unique to each cell type and apply a k nearest neighbor approach to predict known and unknown cell types. Our method correctly classifies 67/67 independent replication-timing profiles, including those derived from closely related intermediate stages. We also apply this method to derive fingerprints for pluripotency in human and mouse cells. Interestingly, the mouse pluripotency fingerprint overlaps almost completely with previously identified genomic segments that switch from early to late replication as pluripotency is lost. Thereafter, replication timing and transcription within these regions become difficult to reprogram back to pluripotency, suggesting these regions highlight an epigenetic barrier to reprogramming. In addition, the major histone cluster Hist1 consistently becomes later replicating in committed cell types, and several histone H1 genes in this cluster are downregulated during differentiation, suggesting a possible instrument for the chromatin compaction observed during differentiation. Finally, we demonstrate that unknown samples can be classified independently using site-specific PCR against fingerprint regions. In sum, replication fingerprints provide a comprehensive means for cell characterization and are a promising tool for identifying regions with cell type-specific organization

Состояния настроения студентов-спортсменов: профили развития, предпосылки и последствия

Рукопись поступила в редакцию: 14.01.2022.Received: 14.01.2022.Цель исследования заключается в получении информации о психическом здоровье молодых финских спортсменов старшего школьного возраста с точки зрения профилей состояний настроения. Было описано шесть разных профилей. Общий показатель настроения был выше у женщин, чем у мужчин. Энергетический индекс был самым высоким у мужчин в индивидуальных видах спорта и самым низким у мужчин в командных видах спорта. У женщин в индивидуальных видах спорта он был ниже, чем у мужчин в индивидуальных видах спорта, и выше в командных видах спорта, чем у мужчин. Он был выше у женщин в индивидуальных видах спорта, чем у женщин в командных видах спорта.The aim of the study is to obtain information about the mental health of young Finnish athletes of high school age in terms of mood state profiles. Six different profiles were described. The overall mood score of women was higher than of men. The energy index was the highest for the men in individual sports and the lowest one was for the men in team sports. For the women in individual sports, it was lower than for men in individual sports. For the women in team sports it was higher than for men in team sports. The energy index was higher for women in individual sports than for women in team sports

Electron spin resonance in membrane research: protein–lipid interactions from challenging beginnings to state of the art

Conventional electron paramagnetic resonance (EPR) spectra of lipids that are spin-labelled close to the terminal methyl end of the acyl chains are able to resolve the lipids directly contacting the protein from those in the fluid bilayer regions of the membrane. This allows determination of both the stoichiometry of lipid–protein interaction (i.e., number of lipid sites at the protein perimeter) and the selectivity of the protein for different lipid species (i.e., association constants relative to the background lipid). Spin-label EPR data are summarised for 20 or more different transmembrane peptides and proteins, and 7 distinct species of lipids. Lineshape simulations of the two-component conventional spin-label EPR spectra allow estimation of the rate at which protein-associated lipids exchange with those in the bulk fluid regions of the membrane. For lipids that do not display a selectivity for the protein, the intrinsic off-rates for exchange are in the region of 10 MHz: less than 10× slower than the rates of diffusive exchange in fluid lipid membranes. Lipids with an affinity for the protein, relative to the background lipid, have off-rates for leaving the protein that are correspondingly slower. Non-linear EPR, which depends on saturation of the spectrum at high radiation intensities, is optimally sensitive to dynamics on the timescale of spin-lattice relaxation, i.e., the microsecond regime. Both progressive saturation and saturation transfer EPR experiments provide definitive evidence that lipids at the protein interface are exchanging on this timescale. The sensitivity of non-linear EPR to low frequencies of spin exchange also allows the location of spin-labelled membrane protein residues relative to those of spin-labelled lipids, in double-labelling experiments

Binary and Millisecond Pulsars at the New Millennium

We review the properties and applications of binary and millisecond pulsars. Our knowledge of these exciting objects has greatly increased in recent years, mainly due to successful surveys which have brought the known pulsar population to over 1300. There are now 56 binary and millisecond pulsars in the Galactic disk and a further 47 in globular clusters. This review is concerned primarily with the results and spin-offs from these surveys which are of particular interest to the relativity community.Comment: 59 pages, 26 figures, 5 tables. Accepted for publication in Living Reviews in Relativity (http://www.livingreviews.org

Divergence of Mammalian Higher Order Chromatin Structure Is Associated with Developmental Loci

Several recent studies have examined different aspects of mammalian higher order chromatin structure - replication timing, lamina association and Hi-C inter-locus interactions - and have suggested that most of these features of genome organisation are conserved over evolution. However, the extent of evolutionary divergence in higher order structure has not been rigorously measured across the mammalian genome, and until now little has been known about the characteristics of any divergent loci present. Here, we generate a dataset combining multiple measurements of chromatin structure and organisation over many embryonic cell types for both human and mouse that, for the first time, allows a comprehensive assessment of the extent of structural divergence between mammalian genomes. Comparison of orthologous regions confirms that all measurable facets of higher order structure are conserved between human and mouse, across the vast majority of the detectably orthologous genome. This broad similarity is observed in spite of many loci possessing cell type specific structures. However, we also identify hundreds of regions (from 100 Kb to 2.7 Mb in size) showing consistent evidence of divergence between these species, constituting at least 10% of the orthologous mammalian genome and encompassing many hundreds of human and mouse genes. These regions show unusual shifts in human GC content, are unevenly distributed across both genomes, and are enriched in human subtelomeric regions. Divergent regions are also relatively enriched for genes showing divergent expression patterns between human and mouse ES cells, implying these regions cause divergent regulation. Particular divergent loci are strikingly enriched in genes implicated in vertebrate development, suggesting important roles for structural divergence in the evolution of mammalian developmental programmes. These data suggest that, though relatively rare in the mammalian genome, divergence in higher order chromatin structure has played important roles during evolution

Comparative Analysis of DNA Replication Timing Reveals Conserved Large-Scale Chromosomal Architecture

Recent evidence suggests that the timing of DNA replication is coordinated across megabase-scale domains in metazoan genomes, yet the importance of this aspect of genome organization is unclear. Here we show that replication timing is remarkably conserved between human and mouse, uncovering large regions that may have been governed by similar replication dynamics since these species have diverged. This conservation is both tissue-specific and independent of the genomic G+C content conservation. Moreover, we show that time of replication is globally conserved despite numerous large-scale genome rearrangements. We systematically identify rearrangement fusion points and demonstrate that replication time can be locally diverged at these loci. Conversely, rearrangements are shown to be correlated with early replication and physical chromosomal proximity. These results suggest that large chromosomal domains of coordinated replication are shuffled by evolution while conserving the large-scale nuclear architecture of the genome