نتایج جستجو برای: background major histocompatibility complex mhc comprises a group of genes

تعداد نتایج: 23367723  

Journal: :Behavioral Ecology and Sociobiology 2023

Abstract Genes of the major histocompatibility complex (MHC) are crucial for adaptive immunity in jawed vertebrates, and theory predicts that there should be mate choice optimizing MHC constitution offspring. In a previous study, we demonstrated non-random female extra-pair males bluethroat ( Luscinia svecica ), yielding offspring was closer to an intermediate class II (MHCII) allele count than...

Journal: :Journal of evolutionary biology 2012
L Gangoso M Alcaide J M Grande J Muñoz S L Talbot S A Sonsthagen G K Sage J Figuerola

The major histocompatibility complex (MHC), which harbours the most polymorphic vertebrate genes, plays a critical role in the host-pathogen coevolutionary arms race. However, the extent to which MHC diversity determines disease susceptibility and long-term persistence of populations is currently under debate, as recent studies have demonstrated that low MHC variability does not necessarily ham...

Journal: :Proceedings. Biological sciences 1996
T von Schantz H Wittzell G Göransson M Grahn K Persson

The major histocompatibility complex (MHC) is an immunologically important cluster of highly variable genes that is known to affect fitness in domesticated mammals and birds. Spur length of male pheasants in southern Sweden correlates with male viability, female mate choice, and offspring survival rate. Here we show by genetic analyses that the MHC genotype is associated with variation in both ...

this thesis attempts to investigate the effects of prelistening activities on enhancing iranian efl learners` listening comprehension. the present study investigated ways in which learners` background knowledge could be activated in order to enhance their l2 listening comprehension by limiting the number of possible text interpretations prior to listening. the experiments conducted in this study examined the effect of prior knowledge and vocabulary teaching on iranian efl learners listening comprehension. the current study has two purposes: one is to investigate the effect of background knowledge on the second language listening comprehension of iranian intermediates and the other is to determine whether second language is facilitated by the introduction of unknown vocabularies in the form of prelistening activities. to conduct the study different instruments such as listening proficiency test and four listening tests such as pre and posttests were used and various statistical processes and techniques including paired-sample t-test, and analysis of variance (anova) were used. the findings of this study supported all three hypotheses tested. differences were found between the means of preteaching vocabulary variable, the background knowledge activation variable, and mean difference between these two strategies variable. subjects scored higher when the unknown words were taught in advance. likewise, subjects scored higher when they were asked some relevant questions about the topic than on those without them. there was, in addition, a significant difference between the means of preteaching vocabulary strategy and background knowledge activation strategy. in fact, preteaching vocabulary had a better effect in enhancing the students’ listening comprehension, in comparison to background knowledge activation strategy.

پایان نامه :دانشگاه آزاد اسلامی - دانشگاه آزاد اسلامی واحد تهران مرکزی - دانشکده زبانهای خارجی 1390

this thesis attempts to investigate the effects of prelistening activities on enhancing iranian efl learners` listening comprehension. the present study investigated ways in which learners` background knowledge could be activated in order to enhance their l2 listening comprehension by limiting the number of possible text interpretations prior to listening. the experiments conducted in this stud...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 1987
D Nizetić F Figueroa Z Dembić E Nevo J Klein

A genomic DNA library prepared from the kidney of the mole rat Spalax ehrenbergi was screened with mouse probes representing major histocompatibility complex genes that encode alpha and beta polypeptide chains of class II molecules (alpha and beta genes). Restriction maps were constructed for the cross-hybridizing clones, and the class II genes borne by these clones were identified. By this pro...

2016
Ryan Mokhtari Herbert M Lachman

Epidemiological studies and mouse models suggest that maternal immune activation, induced clinically through prenatal exposure to one of several infectious diseases, is a risk factor in the development of schizophrenia. This is supported by the strong genetic association established by genome wide association studies (GWAS) between the human leukocyte antigen (HLA) locus and schizophrenia. HLA ...

پایان نامه :وزارت علوم، تحقیقات و فناوری - دانشگاه فردوسی مشهد - دانشکده علوم 1375

this thesis basically deals with the well-known notion of the bear-invariant of groups, which is the generalization of the schur multiplier of groups. in chapter two, section 2.1, we present an explicit formula for the bear-invariant of a direct product of cyclic groups with respect to nc, c>1. also in section 2.2, we caculate the baer-invatiant of a nilpotent product of cyclic groups wuth resp...

Journal: :Clinical immunology 2003
Gerald T Nepom

T cell recognition of specific antigen is initiated by the interaction between TCR molecules and peptide–MHC complexes (pMHC) expressed on the surface of antigenpresenting cells. Soluble pMHC molecules can substitute as ligands in this interaction, binding specifically to T cells expressing the appropriate TCR. Because the monomeric interaction of TCR–pMHC is of low avidity [1–6], multimerizati...

Journal: :Proceedings of the National Academy of Sciences of the United States of America 1997
L F Cadavid C Shufflebotham F J Ruiz M Yeager A L Hughes D I Watkins

Homologues of the human major histocompatibility complex (MHC) HLA-A, -B, -E, -F, and -G loci are present in all the Catarrhini (Old World primates, apes, and humans), and some of their allelic lineages have survived several speciation events. Analysis of 26 MHC class I cDNAs from seven different genera of New World primates revealed that the Callitrichinae (tamarins and marmosets) are an excep...

2014
Chester A Alper

Human major histocompatibility complex (MHC) alleles can be used as markers for a wide variety of autoimmune and other disorders. The interpretation of and possible bases for these associations can be considered in relation to conserved extended MHC haplotypes (CEHs). The latter are fixed stretches of up to several million base pairs of genomic deoxyribonucleic acid (DNA). CEHs constitute at le...

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