139 research outputs found
Gut-associated plasmacytoid dendritic cells display an immature phenotype and upregulated granzyme B in subjects with HIV/AIDS
© 2015 Boichuk, Khaiboullina, Ramazanov, Khasanova, Ivanovskaya, Nizamutdinov, Sharafutdinov, Martynova, DeMeirleir, Hulstaert, Anokhin, Rizvanov and Lombardi. Plasmacytoid dendritic cells (pDCs) in the periphery of subjects with human immunodeficiency virus (HIV)/acquired immunodeficiency syndrome (AIDS) decrease over time, and the fate of these cells has been the subject of ongoing investigation. Previous studies using animal models as well as studies with humans suggest that these cells may redistribute to the gut. Other studies using animal models propose that the periphery pDCs are depleted and gut is repopulated with naive pDCs from the bone marrow. In the present study, we utilized immunohistochemistry to survey duodenum biopsies of subjects with HIV/AIDS and controls. We observed that subjects with HIV/AIDS had increased infiltration of Ki-67+/CD303+ pDCs, a phenotype consistent with bone marrow-derived pre-pDCs. In contrast, Ki-67+/CD303+ pDCs were not observed in control biopsies. We additionally observed that gut-associated pDCs in HIV/AIDS cases upregulate the proapoptotic enzyme granzyme B; however, no granzyme B was observed in the pDCs of control biopsies. Our data are consistent with reports in animal models that suggest periphery pDCs are depleted by exhaustion and that naive pDCs egress from the bone marrow and ultimately infiltrate the gut mucosa. Additionally, our observation of granzyme B upregulation in naive pDCs may identify a contributing factor to the gut pathology associated with HIV infection
Nitrogênio fixado simbioticamente por feijão‑caupi e gliricídia em sistemas tradicional e agroflorestal sob condições semiáridas
The objective of this work was to estimate the amounts of N fixed by cowpea in a traditional system and by cowpea and gliricidia in an agroforestry system in the Brazilian Northeast semiarid. The experiment was carried out in a randomized complete block design, in a split‑plot arrangement, with four replicates, in the semiarid region of the state of Paraíba, Brazil. Plots consisted of agroforestry and traditional systems (no trees), and split‑plots of the three crops planted between the tree rows in the agroforestry system. To estimate N fixation, plant samples were collected in the fourth growth cycle of the perennial species and in the fourth planting cycle of the annual species. In the agroforestry system with buffel grass and prickly‑pear cactus, gliricidia plants symbiotically fix high proportions of N (>50%) and contribute with higher N amounts (40 kg ha‑1 in leaves) than in the traditional system (11 kg ha‑1 in grain and 18 kg ha‑1 in straw). In the agroforestry system with maize and cowpea, gliricidia plants do not fix nitrogen, and N input is limited to the fixation by cowpea (2.7 kg ha‑1), which is lower than in the traditional system due to its lower biomass production.O objetivo deste trabalho foi estimar as quantidades de N fixadas em feijão‑caupi em sistema tradicional e em feijão‑caupi e gliricídia em sistema agroflorestal, sob condições semiáridas do Nordeste brasileiro. O experimento foi conduzido em blocos ao acaso, em arranjo em parcelas subdivididas, com quatro repetições, no semiárido da Paraíba. As parcelas consistiram dos sistemas agroflorestal e tradicional (sem árvores), e as subparcelas, dos três cultivos entre as linhas das árvores, no sistema agroflorestal. Para estimar a fixação de N, amostras das plantas foram coletadas no quarto ciclo de crescimento das espécies perenes e no quarto ciclo de cultivo das espécies anuais. No sistema agroflorestal com capim‑buffel e palma forrageira, a gliricídia fixa simbioticamente altas proporções de N (>50%) e adiciona quantidades maiores de N (40 kg ha‑1 nas folhas) que no sistema tradicional (11 kg ha‑1 nos grãos e 18 kg ha‑1 na palhada). No sistema agroflorestal com milho e feijão‑caupi, a gliricídia não fixa N e a adição de N é limitada à fixação no feijão‑caupi (2,7 kg ha‑1), que é menor que no sistema tradicional em razão da sua baixa produção de biomassa
Mechanical and Electronic Properties of MoS Nanoribbons and Their Defects
We present our study on atomic, electronic, magnetic and phonon properties of
one dimensional honeycomb structure of molybdenum disulfide (MoS) using
first-principles plane wave method. Calculated phonon frequencies of bare
armchair nanoribbon reveal the fourth acoustic branch and indicate the
stability. Force constant and in-plane stiffness calculated in the harmonic
elastic deformation range signify that the MoS nanoribbons are stiff quasi
one dimensional structures, but not as strong as graphene and BN nanoribbons.
Bare MoS armchair nanoribbons are nonmagnetic, direct band gap
semiconductors. Bare zigzag MoS nanoribbons become half-metallic as a
result of the (2x1) reconstruction of edge atoms and are semiconductor for
minority spins, but metallic for the majority spins. Their magnetic moments and
spin-polarizations at the Fermi level are reduced as a result of the
passivation of edge atoms by hydrogen. The functionalization of MoS
nanoribbons by adatom adsorption and vacancy defect creation are also studied.
The nonmagnetic armchair nanoribbons attain net magnetic moment depending on
where the foreign atoms are adsorbed and what kind of vacancy defect is
created. The magnetization of zigzag nanoribbons due to the edge states is
suppressed in the presence of vacancy defects.Comment: 11 pages, 5 figures, first submitted at November 23th, 200
BN domains included into carbon nanotubes: role of interface
We present a density functional theory study on the shape and arrangement of
small BN domains embedded into single-walled carbon nanotubes. We show a strong
tendency for the BN hexagons formation at the simultaneous inclusion of B and N
atoms within the walls of carbon nanotubes. The work emphasizes the importance
of a correct description of the BN-C frontier. We suggest that BN-C interface
will be formed preferentially with the participation of N-C bonds. Thus, we
propose a new way of stabilizing the small BN inclusions through the formation
of nitrogen terminated borders. The comparison between the obtained results and
the available experimental data on formation of BN plackets within the single
walled carbon nanotubes is presented. The mirror situation of inclusion of
carbon plackets within single walled BN nanotubes is considered within the
proposed formalism. Finally, we show that the inclusion of small BN plackets
inside the CNTs strongly affects the electronic character of the initial
systems, opening a band gap. The nitrogen excess in the BN plackets introduces
donor states in the band gap and it might thus result in a promising way for
n-doping single walled carbon nanotubes
Геногеография ели европейской (Picea abies (L.) Karst.) по данным анализа цитоплазматической ДНК
Norway spruce (Picea abies (L.) Karst.) is one of the main forest-forming species in Belarus. It plays important economic, ecological and social roles. The spruce forest of the region is characterized by a complex history of the formation of its population genetic structure. The aim of this study was the genogeographic analysis of P. abies populations and the description of regional features of its gene pool in Belarus. Molecular genetic analysis of microsatellite (SSR) loci of chloroplast DNA and mt15-D02 locus of mitochondrial DNA of Norway spruce was carried out for samples from 57 naturally originated forest stands. We identified 19 allelic variants of the Pt63718, Pt26081, Pt71936 cpDNA loci and two allelic variants of mt15-D02 mtDNA. The geographical distribution of the alleles has been described and the regional features of the genogeographic differentiation of the spruce forests have been considered. The southern border of the continuous distribution area of P. abies and its island localities lie in the south of Belarus (Brest and Gomel regions). The frequency of occurrence of individual allelic variants of cpDNA SSR loci has the most pronounced deviations from the average values for the whole country in those regions. Analysis of cpDNA showed the presence of certain regional features of the genogeographic structure of the spruce forest in the “south-north” and “west-east” directions. According to mitochondrial DNA analysis higher concentration of P. abies trees of southern (Carpathian) origin is observed in the southwest of Belarus. On the contrary northern (Boreal) origin dominates in the rest of the country. The results of performed genogeographic analysis of Norway spruce populations can serve as a basis for improving the forest seed zoning of the tree species.Ель европейская (Picea abies (L.) Karst.) является одним из основных лесообразующих видов Беларуси, выполняя важные экономические, экологические и социальные функции. Еловая формация региона характеризуется сложной историей формирования своей популяционно-генетической структуры. Целью данной работы являлся геногеографический анализ популяций P. abies и установление региональных особенностей ее генофонда на территории Беларуси. Проведен молекулярно-генетический анализ микросателлитных (SSR) локусов хлоропластной ДНК и локуса mt15-D02 митохондриальной ДНК P. abies в 57 древостоях естественного происхождения. Выявлено 19 аллельных вариантов локусов Pt63718, Pt26081, Pt71936 хпДНК и два аллельных варианта mt15-D02 мтДНК. Установлено географическое распространение аллелей и рассмотрены региональные особенности геногеографической дифференциации еловой формации. Для еловых древостоев юга Беларуси (Брестская и Гомельская области), где пролегает южная граница сплошной области распространения P. abies и ее островные местонахождения, частота встречаемости отдельных аллельных вариантов SSR-локусов хпДНК имеет наиболее выраженные отклонения от их средних значений по стране. Анализ хпДНК показал наличие определенных региональных особенностей геногеографической структуры еловой формации в направлении «юг–север» и «запад–восток», а мтДНК – концентрацию на юго-западе Беларуси деревьев P. abies южного (карпатского) происхождения, на остальной части страны – северного (бореального). Результаты проведенного геногеографического анализа популяций P. abies могут служить основой для совершенствования лесосеменного районирования данного вида
Территориальное распределение аллелей SSR-локусов хлоропластной ДНК сосны обыкновенной (Pinus sylvestris L.) в Беларуси
Scotch pine (Pinus sylvestris L.) is one of the main forest forming species in Belarus, which cover 49.2 % of the country’s forested area. The aim of the study was to investigate spatial distribution of microsatellite (SSR) alleles (chloroplast DNA) and identify the features of the genetic structure and genogeographic differentiation of P. sylvestris populations in Belarus. Molecular genetic analysis of six SSR loci of Scotch pine cpDNA in samples form 73 naturally originated stands was carried out. 35 allelic variants of loci PCP1289, PCP4507, PCP83314, PCP71987, PCP26106, PCP30277 were identified. The analysis of the geographic distribution of the dominant allelic variants showed that the population structure of the pine forest is rather homogeneous. Certain regional differences in a number of cases were found for less common, but also widespread variants. One group of alleles is characterized by an increase or decrease in the frequency of occurrence in the direction from the southwest to the northeast. Another group includes allelic variants which share is maximal in the zone covering the Grodno region, the southwestern part of the Minsk region and the Gomel region, while to southwest and to northeast from this zone their frequency of occurrence decreases or is absent. A number of alleles were found only in one of the analyzed stands or in a limited area, which may indicate their local origin as a result of spontaneous mutations. The obtained results are important both from a general biological point of view in studying the evolution and formation of the genetic structure of P. sylvestris in Belarus, and from a practical point of view, since they allow to improve the forest seed zoning of the species.Cосна обыкновенная (Pinus sylvestris L.) является одним из основных лесообразующих видов Беларуси, древостои которой занимают 49,2 % лесопокрытой площади страны. Целью исследования являлось выявление на основе изучения территориального распределения аллелей микросателлитных (SSR) локусов хлоропластной ДНК особенностей генетической структуры и геногеографической дифференциации популяций P. sylvestris в Беларуси. Проведен молекулярно-генетический анализ шести SSR-локусов хпДНК сосны обыкновенной в 73 древостоях естественного происхождения. Выявлено 35 аллельных вариантов локусов PCP1289, PCP4507, PCP83314, PCP71987, PCP26106, PCP30277. Анализ географического распространения аллельных вариантов показал, что по доминирующим вариантам популяционная структура сосновой формации достаточно однородна. Определенные региональные отличия в ряде случаев обнаружены по менее встречающимся, но также широко распространенным вариантам. Одна группа аллелей характеризуется увеличением или уменьшением частоты встречаемости в направлении с юго-запада на северо-восток. Другая группа включает аллельные варианты, долевое участие которых максимально в зоне, охватывающей Гродненскую область, юго-западную часть Минской области и Гомельскую область, в то время как юго-западнее или северо-восточнее от этой зоны отмечается снижение их частоты встречаемости или отсутствие. Ряд аллелей встречался только в одном из проанализированных древостоев или же на ограниченной территории, что может свидетельствовать об их местном происхождении в результате спонтанных мутаций. Полученные результаты важны как с общебиологической точки зрения при изучении эволюции и процессов формирования генетической структуры P. sylvestris в Беларуси, так и с практической, поскольку позволяют совершенствовать лесосеменное районирование вида
Current problems of concluding an agreement on the alimony payment for minors in Russia
The purpose of the manuscript is to analyze the trends and peculiarities of contractual regulation of alimony obligations concerning minors in Russia. The authors use a set of philosophical, general and special scientific methods of cognition of theoretical and empirical materials. In the course of the research, a dialectical-materialistic method was used to study the norms of family and civil law in their interrelations, interdependence, contradictions, taking into account all-roundness and objectivity in the study. In order to conduct a comprehensive study of problematic issues, general scientific methods (analysis, synthesis, deduction, induction, systemic) and private-science (comparative-legal, formal-legal, technical-legal, social modeling of the research) methods of cognition are used in the manuscript. The proposed comparative legal study allows for determining the main directions for the following: comprehensive improvement of the legal norms for the protection of the interests of the child in the process of divorcing parents, establishing the subject composition of agreements on the payment of alimony, determining the criteria for taking into account the various factors of participation in the life of the child when calculating the amount of content, developing a system of extra-judicial resolution of material welfare issues of the child during divorce, to optimize judicial practice, create a comfortable atmosphere for the development and upbringing of children. © 2019, ASERS Publishing House. All rights reserved
Genetic diversity and structure of the Norway spruce Picea abies (L.) H. Karst. seed orchards of the first and the second order in Belarus
The genetic diversity of 5 seed orchards of the first (I) and 12 the second (II) orders of the Norway spruce Picea abies (L.) H. Karst. was analyzed on basis of the isoenzyme analysis method, was carried the study with 18 isoenzyme genes. Allelic frequencies of occurrence of the isoenzyme loci were established and the basic indicators of genetic diversity of seed orchards of Norway spruce were calculated (proportion of polymorphic loci, number of alleles per locus, mean heterozygosity) and their comparison with the average stock of genetic diversity of spruce stands of natural origin was conducted. Seed orchards I and II orders are not inferior to natural populations by the proportion of polymorphic loci P95 (0.39, 0.44 and 0.44, respectively). In the case of indicator P99, most seed orchards are comparable to natural stands, however, values of P99 for seed orchards I and II orders as a whole are significantly lower than in natural populations (0.50, 0.50 and 0.67, respectively). Range of allelic diversity in seed orchards is higher than in stands of Norway spruce of production forests. However, many allelic variants in the analyzed totality of seed orchards had a frequency of less than 1 %, although they were found in the spruce formation of Belarus with a frequency of 1 to 5 %. The average values of heterozygosity in seed orchards I order are significantly lower (0.127 and 0.131, respectively) with those in stands of production forests of Belarus (0.147 and 0.150, respectively); in seed orchards II order vice versa – are significantly higher (0.163 and 0.162, respectively). The obtained values of the inbreeding coefficients FIS and FIT for seed orchards I and II orders indicate that they are in equilibrium according to Hardy-Weinberg. The genetic structure of seed orchards I and II orders is characterized by homogeneity because coefficients FST and GST have low values (not higher 0.011 and 0.012, respectively). Assessment of degree of genetic differentiation revealed a similarity of the genetic structures of the studied seed orchards and spruce stands of natural origin of production forests
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