210 research outputs found

    Three very young HgMn stars in the Orion OB1 Association

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    We report the detection of three mercury-manganese stars in the Orion OB1 association. HD 37886 and BD-0 984 are in the approximately 1.7 million year old Orion OB1b. HD 37492 is in the approximately 4.6 million year old Orion OB1c. Orion OB1b is now the youngest cluster with known HgMn star members. This places an observational upper limit on the time scale needed to produce the chemical peculiarities seen in mercury-manganese stars, which should help in the search for the cause or causes of the peculiar abundances in HgMn and other chemically peculiar upper main sequence stars.Comment: 8 pages including 1 figure. To appear in Astrophysical Journal Letter

    Macrophage polarization in sarcoidosis

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    Sarcoidosis is a systemic inflammatory disease of unknown etiology, characterized by the formation of epithelioid cell granulomas, multisystem lesions with a certain frequency of involvement of various organs, mainly the lungs (up to 90% of cases). Over the past decade, significant progress has been made in understanding the pathogenesis of sarcoidosis, the important role of immunological, genetic and environmental factors in the development of this pathology has been established. It is believed that the leading mechanism in the pathogenesis of sarcoidosis is the aberrant activation of the innate and adaptive immune response to unidentified antigen(s), which leads to the development of granulomatous inflammation and the formation of granulomas. However, despite the huge number of studies that has been carried out, the mechanisms and signaling pathways that control the development of the inflammatory process during the formation of granulomas and the progression of pathology have not been fully determined.This literature review examines the important role of various cytokines and T helper subpopulations in sarcoidosis. Particular attention is paid to the cells of innate immunity – macrophages in the pathogenesis of this disease. These cells play a key role in the formation of sarcoid granulomas and in the pathogenesis of sarcoidosis. The macrophage population is characterized by plasticity and functional heterogeneity. In response to various signals from the microenvironment, macrophages are able to acquire certain phenotypes. The review considers the issues of polarization of macrophages, changes in the phenotype of these cells to subpopulations M1 (M1 phenotype; classically activated; pro-inflammatory) and M2 (M2 phenotype; alternatively activated, anti-inflammatory). These two cell populations are characterized by the expression of different markers on their surface, which allow these cells to differentiate from each other. The analysis of literature data on the levels of key polarizing cytokines for macrophages and cells-producers of these cytokines that patients with sarcoidosis have, in acute and chronic course of the disease, was carried out.Important aspects of the alternative activation of macrophages of the M2 phenotype and their division into subtypes: M2a, M2b, M2c, M2d are noted. The features of various subtypes’ activation of macrophages in this granulomatosis and their importance in the development and progression of pathology are considered. Studying the role of macrophages’ phenotypes, understanding the mechanisms by which the phenotypes of these cells are activated and modulated in various microenvironmental conditions, can contribute to the development and implementation into clinical practice of new therapeutic approaches for the treatment of sarcoidosis and many other forms of pathologies

    High dietary folate in pregnant mice leads to pseudo-MTHFR deficiency and altered methyl metabolism, with embryonic growth delay and short-term memory impairment in offspring

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    Methylenetetrahydrofolate reductase (MTHFR) generates methyltetrahydrofolate for methylation reactions. Severe MTHFR deficiency results in homocystinuria and neurologic impairment. Mild MTHFR deficiency (677C > T polymorphism) increases risk for complex traits, including neuropsychiatric disorders. Although low dietary folate impacts brain development, recent concerns have focused on high folate intake following food fortification and increased vitamin use. Our goal was to determine whether high dietary folate during pregnancy affects brain development in murine offspring. Female mice were placed on control diet (CD) or folic acid-supplemented diet (FASD) throughout mating, pregnancy and lactation. Three-week-old male pups were evaluated for motor and cognitive function. Tissues from E17.5 embryos, pups and dams were collected for choline/methyl metabolite measurements, immunoblotting or gene expression of relevant enzymes. Brains were examined for morphology of hippocampus and cortex. Pups of FASD mothers displayed short-term memory impairment, decreased hippocampal size and decreased thickness of the dentate gyrus. MTHFR protein levels were reduced in FASD pup livers, with lower concentrations of phosphocholine and glycerophosphocholine in liver and hippocampus, respectively. FASD pup brains showed evidence of altered acetylcholine availability and Dnmt3a mRNA was reduced in cortex and hippocampus. E17.5 embryos and placentas from FASD dams were smaller. MTHFR protein and mRNA were reduced in embryonic liver, with lower concentrations of choline, betaine and phosphocholine. Embryonic brain displayed altered development of cortical layers. In summary, high folate intake during pregnancy leads to pseudo-MTHFR deficiency, disturbed choline/methyl metabolism, embryonic growth delay and memory impairment in offspring. These findings highlight the unintended negative consequences of supplemental folic acid

    Features of COVID-19 course in patients with obesity and dysglycemia

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    Aim. To study the features of coronavirus disease 2019 (COVID-19) in patients with different severity of carbohydrate metabolism disorders (CMDs), taking into account the possible role of obesity in the acceleration of clinical and laboratory disorders.Material and methods. There were 137 consecutive patients admitted to the infectious disease hospital for COVID-19patients. Three 3 groups were formed: group 1 — 42 patients with concomitant type 2 diabetes (T2D); group 2 — 13 patients with concomitant prediabetes; group 3 — 82 patients without concomitant CMDs.Results. Patients with T2D tended to have a more severe disease course according to the SMRT-CO algorithm (p=0,089), which was associated with the longest hospital stay (p=0,038), the most pronounced (p=0,011) and prolonged (p=0,0001) decrease in oxygen saturation, the maximum percentage of lung injury at the beginning (p=0,094) and at the end (p=0,007) of hospitalization, the greater need for intensive care unit (p=0,050), as well as the highest increase in C-reactive protein and fibrinogen (hypercoagulability and systemic inflammation were noted in all groups). Patients with prediabetes in terms of COVID-19 severity occupied an intermediate position between those with T2D and without CMDs; at the same time, they most often needed the prescription of biological preparations (p=0,001). In the first and second groups, there were larger, compared with the control, proportions of obese people (61,9%, 53,8% and 30,5%, respectively, p=0,003). Prediabetes group had a strong correlation between the severity of viral pneumonitis according to SMRT-CO and the presence of obesity (R=0,69, p=0,009).Conclusion. In patients with impaired carbohydrate metabolism of any severity, COVID-19 is more severe. At the same time, persons with overt T2D are prone to the most severe COVID-19 course, while patients with prediabetes in terms of disease severity occupy an intermediate position between them and those without CMDs. Obesity is a strong risk factor for severe COVID-19 among patients with initial CMDs (prediabetes), which is partly mediated by prior liver dysfunction associated with the metabolic syndrome. The increase in proinflammatory changes and hypercoagulability is associated with COVID-19 severity in patients with and without CMDs. These disorders had the greatest severity and persistence in patients with T2D

    Wheat-barley hybridization – the last forty years

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    Abstract Several useful alien gene transfers have been reported from related species into wheat (Triticum aestivum), but very few publications have dealt with the development of wheat/barley (Hordeum vulgare) introgression lines. An overview is given here of wheat 9 barley hybridization over the last forty years, including the development of wheat 9 barley hybrids, and of addition and translocation lines with various barley cultivars. A short summary is also given of the wheat 9 barley hybrids produced with other Hordeum species. The meiotic pairing behaviour of wheat 9 barley hybrids is presented, with special regard to the detection of wheat– barley homoeologous pairing using the molecular cytogenetic technique GISH. The effect of in vitro multiplication on the genome composition of intergeneric hybrids is discussed, and the production and characterization of the latest wheat/barley translocation lines are presented. An overview of the agronomical traits (b-glucan content, earliness, salt tolerance, sprouting resistance, etc.) of the newly developed introgression lines is given. The exploitation and possible use of wheat/barley introgression lines for the most up-to-date molecular genetic studies (transcriptome analysis, sequencing of flow-sorted chromosomes) are also discussed

    The chromosome content and genotype of two wheat cell lines and of their somatic fusion product with oat

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    Somatic hybridization seeks to genetically combine phylogenetically distant parents. An effective system has been established in bread wheat (Triticum aestivum L.) involving protoplasts from a non-totipotent cell line adapted to in vitro culture (T1) in combination with totipotent protoplasts harvested from embryogenic calli (T2). Here, we report the karyotype and genotype of T1 and T2. Line T1 carries nine A (A-genome of wheat), seven B (B-genome of wheat) and eight D (D-genome of wheat) genome chromosomes, while T2 cells have 12 A, 10 B and 12 D genome chromosomes. Rates of chromosome aberration in the B- and D-genomes were more than 25%, higher than in the A-genome. DNA deletion rates were 55.6% in T1 and 19.4% in T2, and DNA variation rates were 8.3% in T1 and 13.9% in T2. Rate of DNA elimination was B- > D- > A-genome in both T1 and T2. The same set of cytological and genetic assays was applied to a derivative of the somatic fusion between protoplasts of T1, T2 and oat (Avena sativa L.). The regenerant plants were near euploid with respect to their wheat complement. Six wheat chromosome arms—4AL, 3BS, 4BL, 3DS, 6DL and 7DL—carried small introgressed segments of oat chromatin. A genotypic analysis of the hybrid largely confirmed this cytologically-based diagnosis

    Fungal planet description sheets: 951–1041

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    Novel species of fungi described in this study include those from various countries as follows: Antarctica , Apenidiella antarctica from permafrost, Cladosporium fildesense fromanunidentifiedmarinesponge. Argentina , Geastrum wrightii onhumusinmixedforest. Australia , Golovinomyces glandulariae on Glandularia aristigera, Neoanungitea eucalyptorum on leaves of Eucalyptus grandis, Teratosphaeria corymbiicola on leaves of Corymbia ficifolia, Xylaria eucalypti on leaves of Eucalyptus radiata. Brazil, Bovista psammophila on soil, Fusarium awaxy on rotten stalks of Zea mays, Geastrum lanuginosum on leaf litter covered soil, Hermetothecium mikaniae-micranthae (incl. Hermetothecium gen. nov.)on Mikania micrantha, Penicillium reconvexovelosoi in soil, Stagonosporopsis vannaccii from pod of Glycine max. British Virgin Isles , Lactifluus guanensis onsoil. Canada , Sorocybe oblongispora on resin of Picea rubens. Chile, Colletotrichum roseum on leaves of Lapageria rosea. China, Setophoma caverna fromcarbonatiteinKarstcave. Colombia , Lareunionomyces eucalypticola on leaves of Eucalyptus grandis. Costa Rica, Psathyrella pivae onwood. Cyprus , Clavulina iris oncalcareoussubstrate. France , Chromosera ambigua and Clavulina iris var. occidentalis onsoil. French West Indies , Helminthosphaeria hispidissima ondeadwood. Guatemala , Talaromyces guatemalensis insoil. Malaysia , Neotracylla pini (incl. Tracyllales ord. nov. and Neotra- cylla gen. nov.)and Vermiculariopsiella pini on needles of Pinus tecunumanii. New Zealand, Neoconiothyrium viticola on stems of Vitis vinifera, Parafenestella pittospori on Pittosporum tenuifolium, Pilidium novae-zelandiae on Phoenix sp. Pakistan , Russula quercus-floribundae onforestfloor. Portugal , Trichoderma aestuarinum from salinewater. Russia , Pluteus liliputianus on fallen branch of deciduous tree, Pluteus spurius on decaying deciduouswoodorsoil. South Africa , Alloconiothyrium encephalarti, Phyllosticta encephalarticola and Neothyrostroma encephalarti (incl. Neothyrostroma gen. nov.)onleavesof Encephalartos sp., Chalara eucalypticola on leaf spots of Eucalyptus grandis × urophylla, Clypeosphaeria oleae on leaves of Olea capensis, Cylindrocladiella postalofficium on leaf litter of Sideroxylon inerme , Cylindromonium eugeniicola (incl. Cylindromonium gen. nov.)onleaflitterof Eugenia capensis , Cyphellophora goniomatis on leaves of Gonioma kamassi , Nothodactylaria nephrolepidis (incl. Nothodactylaria gen. nov. and Nothodactylariaceae fam. nov.)onleavesof Nephrolepis exaltata , Falcocladium eucalypti and Gyrothrix eucalypti on leaves of Eucalyptus sp., Gyrothrix oleae on leaves of Olea capensis subsp. macrocarpa , Harzia metro sideri on leaf litter of Metrosideros sp., Hippopotamyces phragmitis (incl. Hippopota- myces gen. nov.)onleavesof Phragmites australis , Lectera philenopterae on Philenoptera violacea , Leptosillia mayteni on leaves of Maytenus heterophylla , Lithohypha aloicola and Neoplatysporoides aloes on leaves of Aloe sp., Millesimomyces rhoicissi (incl. Millesimomyces gen. nov.) on leaves of Rhoicissus digitata , Neodevriesia strelitziicola on leaf litter of Strelitzia nicolai , Neokirramyces syzygii (incl. Neokirramyces gen. nov.)onleafspots o

    The mental health continuum-short form: the structure and application for cross-cultural studies-A 38 nation study

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    Objective: The Mental Health Continuum-Short Form (MHC-SF) is a brief scale measuring positive human functioning. The study aimed to examine the factor structure and to explore the cross-cultural utility of the MHC-SF using bifactor models and exploratory structural equation modelling. Method: Using multigroup confirmatory analysis (MGCFA) we examined the measurement invariance of the MHC-SF in 38 countries (university students, N = 8,066; 61.73% women, mean age 21.55 years). Results: MGCFA supported the cross-cultural replicability of a bifactor structure and a metric level of invariance between student samples. The average proportion of variance explained by the general factor was high (ECV =.66), suggesting that the three aspects of mental health (emotional, social, and psychological well-being) can be treated as a single dimension of well-being. Conclusion: The metric level of invariance offers the possibility of comparing correlates and predictors of positive mental functioning across countries; however, the comparison of the levels of mental health across countries is not possible due to lack of scalar invariance. Our study has preliminary character and could serve as an initial assessment of the structure of the MHC-SF across different cultural settings. Further studies on general populations are required for extending our findings.info:eu-repo/semantics/acceptedVersio
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