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101.
The specificity of a weak gamma delta TCR interaction can be modulated by the glycosylation of the ligand. 总被引:1,自引:0,他引:1
J Hampl H Schild C Litzenberger M Baron M P Crowley Y H Chien 《Journal of immunology (Baltimore, Md. : 1950)》1999,163(1):288-294
The gamma delta T cell clone LBK5 recognizes the MHC molecule IEk. Here, we demonstrate that the affinity of this interaction is weaker than those typically reported for alpha beta TCRs that recognize peptide/MHC complexes. Consistent with our previous finding that peptide bound to the IE molecule does not confer specificity, we show that the entire epitope for LBK5 is contained within the polypeptide chains of the molecule, centered around the polymorphic residues 67 and 70 of the IE beta-chain. However, LBK5 recognition is profoundly influenced by the N-linked glycosylation at residue 82 of the IE alpha-chain. Since infected, stressed, or transformed cells often change the posttranslational modifications of their surface glycoproteins, this finding suggests a new way in which gamma delta T cell Ag recognition can be regulated. 相似文献
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Josiah MC Heyman 《The journal of the Royal Anthropological Institute》2000,6(4):635-652
High-scale morality is the study of moral ideas and sentiments deployed in relations that encompass multiple, geographically or socially distant populaces. The envisioning of distant people, their attributed moral personhood, the evaluation of their perceived behaviour, and the rectification of wrongs through the use of powerful organizations are key topics in high-scale morality. High-scale morality differs from existing anthropological approaches that emphasize local ethnography or contrastive moral ideas; it addresses the moralization of issues like world hunger, the drug trade, or international migration. The officers of the US Immigration and Naturalization Service understand and evaluate legal and illegal immigrants, as well as directly enacting moral rectification for the US polity. As they resolve moral dilemmas on their job, they utilize pervasive models for moral thought and action in capitalist, individualist, stratified, and bureaucratized societies. The article finishes by considering directions in which anthropology can contribute to understanding the moral dimension of global issues. 相似文献
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Males and females of many organisms differ in important life-history and behavioral characters. Following a recent optimization analysis of sexually dimorphic life histories, we employed an odonate-like parameter set to identify patterns of life history and behavior to be expected in an odonate population. The default parameter magnitudes generated a smaller body size and shorter development time for males than for females, which resulted in a male-biased sex ratio. Whether population growth was density dependent or density independent, and whether development time was fixed or flexible had major impacts on life-history features. The model generated five general predictions for odonate systems. (1) For species with fixed development times, males and females should differ more in activity level, growth and mortality rates than for species with flexible life cycles. (2) In species with fixed development times, populations at high latitude or high altitude should be more active, emerge and reproduce at smaller size and have a more male-biased sex ratio than low latitude and low altitude populations. (3) In density-dependent populations, with density dependence mediated by activity-dependent mortality, higher predation rates should increase activity levels and reduce development time in species with flexible development times. (4) For species with flexible development times, in strongly density-dependent populations with density dependence mediated by mortality, activity levels should decrease and development times should increase at high prey abundance. (5) Males should be larger at emergence relative to females, and the sex ratio at emergence should be more female-biased in territorial than in non-territorial species. Existing empirical evidence concerning these predictions is generally sparse and equivocal; focused tests are clearly needed. 相似文献
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Thomas J. Crowley Daniel F. Kripke Franz Halberg G. V. Pegram J. J. Schildkraut 《Primates; journal of primatology》1972,13(2):149-167
EEG, EOG, EMG, gross activity, and temperature were continuously recorded over 24 hours from 38 maleMacaca mulatta monkeys. EEG, EOG, and EMG were translated into standard Sleep Stages. The EEG also was automatically filtered, rectified, integrated, digitized, and plotted. Results are presented first as 24-hour plots for temperature, Sleep Stages Awake, 1–2, 3–4, and REM, for EMG, gross motion, EOG, and for the occurrence of EEG bands delta, theta, alpha, sigma, and beta.Twenty-four-hour cosine curves were fitted to the data by least squares, demonstrating and quantifying with confidence intervals a circadian rhythm in each function. During the 12-hour dark span the acrophases, or peaks of the cosines fitted to the data, appeared in the following clockwise order: Stage 3–4, delta, Stage 1–2, Stage REM, total EEG, and theta. The clockwise order of acrophases appearing in the light span was: alpha, gross motion, sigma, beta, EMG, EOG, temperature, and Stage Awake. Circadian amplitudes are given for each rhythm.Three of these measures of brain function had circadian rises or falls which appeared to be influenced by the daily times of light-on or -off. Lighting acted as circadian phase-synchronizing stimulus for temperature and the EEG bands beta and sigma.The data demonstrate circadian rhythms for certain parameters associated with sleep—delta, theta, Stage REM, and Stage 3–4 and important differences in phase. This finding constitutes another line of evidence that sleep is not unitary, consisting rather of related but separately controlled rhythmic functions.Considerable phylogenetic constancy appears when these data on circadian phasing are compared with similar data from other primates, including man.The experimental work was part of Aeromedical Research Laboratory Project 6892, Holloman Air Force Base, U.S.A.F. Biochemical assays were supported by the U.S.P.H.S. (MH 15413). Data analysis performed at the University of Minnesota was supported by NASA (NAS 2-2738 and NGR-24-005-006), the U.S. Air Force (F29608-69-C-0011), and by the USPHS (CA 5-K6-GM 13981). Further reproduction of this article is authorized as needed to meet the requirements of the U.S. government. The animals used in this study were handled in accordance with the Guide for Laboratory Animal Facilities and Care published by the National Academy of Science-National Research Council. Drs.Crowley andKripke were on active duty, and Dr.Pegram was a civilian employee with the USAF during part of this project. 相似文献
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