122 research outputs found
Identification of candidate genes affecting chronic subclinical mastitis in Norwegian Red cattle: combining genome‐wide association study, topologically associated domains and pathway enrichment analysis
The aim of this study was to identify genes associated with chronic subclinical mastitis (SCM) in Norwegian Red (NR) cattle. Twelve SCM traits defined based on fixed threshold for test‐day somatic cell count (SCC) were, together with lactation‐average somatic cell score (LSCS) used for association and pathway enrichment analyses. A GWAS was performed on 3795 genotyped NR bulls with 777K SNP data and phenotypic information from 7 300 847 test‐day SCC observations from 3 543 764 cows. At 5% chromosome‐wide significance level 36 unique SNP were detected to be associated with one or more of the traits. These SNPs were analysed for linked genes using genomic positions of topologically associated domains (TAD). For the SCM traits with SCC >50 000 and >100 000 cells/ml on two test‐days in a row and LSCS, the same top significant genes were identified – checkpoint clamp loader component (RAD17) and cyclin B1 (CCNB1). The SCM traits with SCC >250 000, 300 000, 350 000 or 400 000 cells/ml on two test‐days in a row and D400 (number of days before the first case with SCC >400 000 cells/ml) displayed similar top significant genes: acyl‐CoA thioesterase 2 and 4 (ACOT2; ACOT4). For the traits SCM200_3 (SCC >200 000 cells/ml on three test‐days in a row) and SCM150, SCM200 (SCC >150 000; 200 000 cells/ml on two test‐days in a row) a group of chemokine (C–X–C motif) ligand genes and the Fos proto‐oncogene, AP‐1 transcription factor subunit (FOS) gene, were identified. Further functional studies of these identified candidate genes are necessary to clarify their actual role in development of chronic SCM in NR cattle.publishedVersio
Connection of Professional Burnout and Working Conditions of Fitness Trainers
В статье освещаются итоги исследования связи проявлений профессионального выгорания и условий работы инструкторов тренажерного зала. За основу взяты как классические учебные материалы о феномене эмоционального выгорания, так и статьи, которые освещают тему выгорания непосредственно у специалистов в области спорта.The article analyzes the relationship between professional burnout and working conditions of fitness trainers. The author highlights the peculiarities of the work of trainers and considers the presence of stress factors. A study of the relationship between the manifestations of professional burnout and the working conditions of gym instructors was conducted. It is based on both classical educational materials on the phenomenon of emotional burnout, and articles from 2020 that cover the topic of burnout directly from specialists in the field of sports
Linker-Free Modification Of TiO2 Nanorods With PbSe Nanocrystals
We report on a colloidal synthesis of Pbse/TiO2 heterostructures, comprising small-diameter PbSe nanocrystals epitaxially grown onto the surface of TiO2 nanorods. The deposition of lead selenide onto prefabricated TiO2 nanocrystals proceeds via formation of a thin PbSe shell that subsequently breaks into sub-2-nm islands. Additional precursor injections are then used to increase the size of PbSe nanocrystals up to 5 nm. In the case of small-size PbSe, a 2.1-ns transfer of photoinduced carriers into TiO2 domain was evidenced through quenching of the PbSe band gap emission. Overall, the present synthesis demonstrates a colloidal approach to all-inorganic modification of TiO2 surfaces with semiconductor nanocrystals, which provides a viable alternative to a more common supramolecular assembly of nanocrystal-oxide composites
3D structure of the H ii region Sh2-235 from tunable-filter optical observations
We present observations of the H α, H β, [S ii] λλ6716, 6731 and [N ii] λ6583 emission lines in the galactic H ii region Sh2-235 with the Mapper of Narrow Galaxy Lines (MaNGaL), a tunable filter at the 1-m telescope of the Special Astrophysical Observatory of the Russian Academy of Sciences. We show that the H ii region is obscured by neutral material with AV ≈ 2-4 mag. The area with the highest AV is situated to the south-west from the ionizing star and coincides with a maximum detected electron density of â 300 cm-3. The combination of these results with archive AKARI far-infrared data allows us to estimate the contribution of the front and rear walls to the total column density of neutral material in S235 and explain the 3D structure of the region. The H ii region consist of a denser, more compact portion deeply embedded in the neutral medium and the less dense and obscured gas. The front and rear walls of the H ii region are inhomogeneous, with the material in the rear wall having a higher column density. We find a two-sided photodissociation region in the dense clump S235 East 1, illuminated by a UV field with G0 = 50-70 and 200 Habing units in the western and eastern parts, respectively. © 2020 The Author(s) Published by Oxford University Press on behalf of the Royal Astronomical Society
NH3 observations of the S235 star-forming region: Dense gas in inter-core bridges
Star formation is thought to be driven by two groups of mechanisms; spontaneous collapse and triggered collapse. Triggered star formation mechanisms further diverge into cloud-cloud collision (CCC), "collect and collapse" (C&C) and shock-induced collapse of pre-existing, gravitationally stable cores, or "radiation driven implosion" (RDI). To evaluate the contributions of these mechanisms and establish whether these processes can occur together within the same star-forming region, we performed mapping observations of radio-frequency ammonia and water maser emission lines in the S235 massive star-forming region. Via spectral analyses of main, hyperfine, and multi-transitional ammonia lines we explored the distribution of temperature and column density in the dense gas in the S235 and S235AB star-forming region. The most remarkable result of the mapping observations is the discovery of high-density gas in inter-core bridges which physically link dense molecular cores that house young proto-stellar clusters. The presence of dense gas implies the potential for future star formation within the system of cores and gas bridges. Cluster formation implies collapse, and the continuous physical links, also seen in re-imaged archival CS and 13CO maps, suggest a common origin to the molecular cores housing these clusters, i.e a structure condensed from a single, larger parent cloud, brought about by the influence of a local expanding H, ii region. An ammonia absorption feature co-locating with the center of the extended H, ii region may be attributed to an older gas component left over from the period prior to formation of the H, ii region. Our observations also detail known and new sites of water maser emission, highlighting regions of active ongoing star formation. © 2019 The Author(s). Published by Oxford University Press on behalf of the Astronomical Society of Japan
Differences between Ca2+ and Mg2+ in DNA binding and release by the SfiI restriction endonuclease: implications for DNA looping
Many enzymes acting on DNA require Mg2+ ions not only for catalysis but also to bind DNA. Binding studies often employ Ca2+ as a substitute for Mg2+, to promote DNA binding whilst disallowing catalysis. The SfiI endonuclease requires divalent metal ions to bind DNA but, in contrast to many systems where Ca2+ mimics Mg2+, Ca2+ causes SfiI to bind DNA almost irreversibly. Equilibrium binding by wild-type SfiI cannot be conducted with Mg2+ present as the DNA is cleaved so, to study the effect of Mg2+ on DNA binding, two catalytically-inactive mutants were constructed. The mutants bound DNA in the presence of either Ca2+ or Mg2+ but, unlike wild-type SfiI with Ca2+, the binding was reversible. With both mutants, dissociation was slow with Ca2+ but was in one case much faster with Mg2+. Hence, Ca2+ can affect DNA binding differently from Mg2+. Moreover, SfiI is an archetypal system for DNA looping; on DNA with two recognition sites, it binds to both sites and loops out the intervening DNA. While the dynamics of looping cannot be measured with wild-type SfiI and Ca2+, it becomes accessible with the mutant and Mg2+
Hundreds of new cluster candidates in the VISTA Variables in the Vía Láctea survey DR1
Context. VISTA variables in the Vía Láctea is an ESO Public survey dedicated to scanning the bulge and an adjacent portion of the Galactic disk in the fourth quadrant using the VISTA telescope and its near-infrared camera VIRCAM. One of the leading goals of the VVV survey is to contribute to knowledge of the star cluster population of the Milky Way. Aims. To improve the census of Galactic star clusters, we performed a systematic and careful scan of the JHKs images of the Galactic plane section of the VVV survey. Methods. Our detection procedure is based on a combination of stellar density maps and visual inspection of promising features in the J-, H-, and KS-band images. The material examined are VVV JHKS color-composite images corresponding to Data Release 1 of VVV. Results. We report the discovery of 493 new infrared star cluster candidates. The analysis of the spatial distribution show that the clusters are very concentrated in the Galactic plane, presenting some local maxima around the position of large star-forming complexes, such as G305, RCW 95, and RCW 106. The vast majority of the new star cluster candidates are quite compact and generally surrounded by bright and/or dark nebulosities. IRAS point sources are associated with 59% of the sample, while 88% are associated with MSX point sources. GLIMPSE 8 μm images of the cluster candidates show a variety of morphologies, with 292 clusters dominated by knotty sources, while 361 clusters show some kind of nebulosity in this wavelength regime. Spatial cross-correlation with young stellar objects, masers, and extended green-object catalogs suggest that a large sample of the new cluster candidates are extremely young. In particular, 104 star clusters associated with methanol masers are excellent candidates for ongoing massive star formation. Also, there is a special set of sixteen cluster candidates that present clear signposts of star-forming activity having associated simultaneosly dark nebulae, young stellar objects, extended green objects, and masers.Peer reviewe
Metadata management for high content screening in OMERO
High content screening (HCS) experiments create a classic data management challenge—multiple, large sets of heterogeneous structured and unstructured data, that must be integrated and linked to produce a set of “final” results. These different data include images, reagents, protocols, analytic output, and phenotypes, all of which must be stored, linked and made accessible for users, scientists, collaborators and where appropriate the wider community. The OME Consortium has built several open source tools for managing, linking and sharing these different types of data. The OME Data Model is a metadata specification that supports the image data and metadata recorded in HCS experiments. Bio-Formats is a Java library that reads recorded image data and metadata and includes support for several HCS screening systems. OMERO is an enterprise data management application that integrates image data, experimental and analytic metadata and makes them accessible for visualization, mining, sharing and downstream analysis. We discuss how Bio-Formats and OMERO handle these different data types, and how they can be used to integrate, link and share HCS experiments in facilities and public data repositories. OME specifications and software are open source and are available at https://www.openmicroscopy.org
Дедифференцировка зрелых крысиных гепатоцитов в длительно пролиферирующие печеночные прогениторные клетки.
Objective: to obtain long-lived proliferating cells with progenitor features by dedifferentiation of mature rat hepatocytes using combinations of small molecules.Materials and Methods. Hepatocytes isolated from rat liver by perfusion were cultured in the presence of a cocktail of three small molecules – Wnt signaling pathway activator (CHIR99021), TGF-β inhibitors (A83-01) and ROCK kinase (Y27632). The morphological characteristics and growth features of the culture were assessed using fluorescence and phase-contrast microscopy during cell culture. Cell proliferative activity was analyzed using real-time time-lapse imaging. The expression of surface and intracellular markers was analyzed using flow cytometry and high-resolution fluorescence microscopy.Results. Using a cocktail of small molecules, Y-27632, A-83-01, and CHIR99021, long-lived proliferating cells that express progenitor cell markers, such as α-fetoprotein and HNF4α, were obtained from mature rat hepatocytes. The cells had hepatocyte-like morphology and formed discrete clusters of proliferating cells, forming a single cell layer during culturing. Removal of the small molecules from the medium led to expansion of fibroblast-like cells and elimination of potentially progenitor hepatocyte-like cells.Conclusion. Proliferating progenitor cells can be obtained by dedifferentiation of mature hepatocytes.Цель: получить длительно пролиферирующие клетки, обладающие признаками прогениторных, за счет дедифференцировки зрелых крысиных гепатоцитов с помощью комбинаций малых молекул.Материалы и методы. Гепатоциты, выделенные из крысиной печени путем перфузии, культивировали в присутствии набора из трех малых молекул: агониста Wnt сигнального пути (CHIR99021), ингибиторов TGF-β (A83-01) и ROCK киназы (Y27632). С помощью флуоресцентной и фазово-контрастной микроскопии в процессе культивирования клеток оценивали морфологические характеристики и особенности роста культуры. Пролиферативную активность клеток анализировали с помощью цейтраферной съемки в режиме реального времени. Экспрессию поверхностных и внутриклеточных маркеров анализировали, используя проточную цитофлуориметрию и флуоресцентную микроскопию высокого разрешения.Результаты. Используя комплекс малых молекул Y-27632, A-83-01 и CHIR99021, из зрелых крысиных гепатоцитов были получены длительно пролиферирующие клетки, которые экспрессировали маркеры прогениторных клеток, такие как α-фетопротеин и HNF4α. Клетки имели гепатоцитоподобную морфологию и формировали дискретные кластеры пролиферирующих клеток, образующих в процессе культивирования единый клеточный пласт. Удаление из среды малых молекул приводило к экспансии фибробластоподобных клеток и к элиминации потенциально прогениторных гепатоцитоподобных клеток.Заключение. Подтверждена возможность получения пролиферирующих прогениторных клеток с помощью дедифференцировки зрелых гепатоцитов
A far-ultraviolet-driven photoevaporation flow observed in a protoplanetary disk.
Most low-mass stars form in stellar clusters that also contain massive stars, which are sources of far-ultraviolet (FUV) radiation. Theoretical models predict that this FUV radiation produces photodissociation regions (PDRs) on the surfaces of protoplanetary disks around low-mass stars, which affects planet formation within the disks. We report James Webb Space Telescope and Atacama Large Millimeter Array observations of a FUV-irradiated protoplanetary disk in the Orion Nebula. Emission lines are detected from the PDR; modeling their kinematics and excitation allowed us to constrain the physical conditions within the gas. We quantified the mass-loss rate induced by the FUV irradiation and found that it is sufficient to remove gas from the disk in less than a million years. This is rapid enough to affect giant planet formation in the disk
- …