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41.
Ron Levi 《Ethnic and racial studies》2017,40(8):1251-1260
What is the role of law and legality in social resilience? This review essay highlights how a sociology of law, culture, and institutions underwrites many of the findings of Getting Respect: Responding to Stigma and Discrimination in the United States, Brazil &; Israel. The book provides a trenchant analysis of group boundaries, stigma, and destigmatization across three cities worldwide. I suggest that in addition to the role of formal law and legal constraints that the book identifies, we can attend to how legality offers a repertoire for resilience on which people draw when faced with stigma, discrimination, or contentious situations, even when formal law falls short. In this way, combining a sociology of law with a sociology of culture can provide us with an understanding of how societies offer social resilience, and how this resource varies across social, national, and legal contexts. 相似文献
42.
Twenty four shift workers (8 from a steel industry and 16 from a Government hospital) participated in the study. The subjects
were instructed to self-measure oral temperature, 4 6 times a day for about three weeks. Sleep quantity and quality for each
subject were analysed with the help of an appropriate inventory. The data were analysed by cosinor and power spectrum methods.
The frequency of circadian rhythm detection was in the order of 48% in senior nurses, 29% in steel plant workers and 14% in
junior nurses. These were also complemented by the results of power spectrum analysis. Present results suggest that rhythms
of subjective fatigue and subjective drowsiness are governed neither by oral temperature oscillator nor by the sleep/wake
cycle oscillator. The results show that shift rotation pattern chiefly modulates the circadian time structure of shift workers.
It is also suggested that the phenomenon of circadian rhythm desynchronization in oral temperature appears to be independent
of per day total sleep length. 相似文献
43.
Ting TC Miyazaki-Anzai S Masuda M Levi M Demer LL Tintut Y Miyazaki M 《The Journal of biological chemistry》2011,286(27):23938-23949
Vascular calcification is recognized as an independent predictor of cardiovascular mortality, particularly in subjects with chronic kidney disease. However, the pathways by which dysregulation of lipid and mineral metabolism simultaneously occur in this particular population remain unclear. We have shown that activation of the farnesoid X receptor (FXR) blocks mineralization of bovine calcifying vascular cells (CVCs) and in ApoE knock-out mice with 5/6 nephrectomy. In contrast to FXR, this study showed that liver X receptor (LXR) activation by LXR agonists and adenovirus-mediated LXR overexpression by VP16-LXRα and VP16-LXRβ accelerated mineralization of CVCs. Conversely, LXR inhibition by dominant negative (DN) forms of LXRα and LXRβ reduced calcium content in CVCs. The regulation of mineralization by FXR and LXR agonists was highly correlated with changes in lipid accumulation, fatty acid synthesis, and the expression of sterol regulatory element binding protein-1 (SREBP-1). The rate of lipogenesis in CVCs through the SREBP-1c dependent pathway was reduced by FXR activation, but increased by LXR activation. SREBP-1c overexpression augmented mineralization in CVCs, whereas SREBP-1c DN inhibited alkaline phosphatase activity and mineralization induced by LXR agonists. LXR and SREBP-1c activations increased, whereas FXR activation decreased, saturated and monounsaturated fatty acids derived from lipogenesis. In addition, we found that stearate markedly promoted mineralization of CVCs as compared with other fatty acids. Furthermore, inhibition of either acetyl-CoA carboxylase or acyl-CoA synthetase reduced mineralization of CVCs, whereas inhibition of stearoyl-CoA desaturase induced mineralization. Therefore, a stearate metabolite derived from lipogenesis might be a risk factor for the development of vascular calcification. 相似文献
44.
Kevin T. Shoemaker Levi J. Heffelfinger Nathan J. Jackson Marcus E. Blum Tony Wasley Kelley M. Stewart 《Ecology and evolution》2018,8(6):3556-3569
Resource selection functions (RSFs) are tremendously valuable for ecologists and resource managers because they quantify spatial patterns in resource utilization by wildlife, thereby facilitating identification of critical habitat areas and characterizing specific habitat features that are selected or avoided. RSFs discriminate between known‐use resource units (e.g., telemetry locations) and available (or randomly selected) resource units based on an array of environmental features, and in their standard form are performed using logistic regression. As generalized linear models, standard RSFs have some notable limitations, such as difficulties in accommodating nonlinear (e.g., humped or threshold) relationships and complex interactions. Increasingly, ecologists are using flexible machine‐learning methods (e.g., random forests, neural networks) to overcome these limitations. Herein, we investigate the seasonal resource selection patterns of mule deer (Odocoileus hemionus) by comparing a logistic regression framework with random forest (RF), a popular machine‐learning algorithm. Random forest (RF) models detected nonlinear relationships (e.g., optimal ranges for slope and elevation) and complex interactions which would have been very challenging to discover and characterize using standard model‐based approaches. Compared with standard RSF models, RF models exhibited improved predictive skill, provided novel insights about resource selection patterns of mule deer, and, when projected across a relevant geographic space, manifested notable differences in predicted habitat suitability. We recommend that wildlife researchers harness the strengths of machine‐learning tools like RF in addition to “classical” tools (e.g., mixed‐effects logistic regression) for evaluating resource selection, especially in cases where extensive telemetry data sets are available. 相似文献
45.
O K Ba?kurt E Levi A Temizer D Ozer S Ca?layan N Dikmeno?lu S O Anda? 《Life sciences》1990,46(20):1471-1477
In vitro effects of thyroxine on erythrocyte deformability and mechanical fragility were observed. Deformability of erythrocytes was improved in a dose dependent manner by thyroxine. Mechanical hemolysis was found to be lower if thyroxine was included in erythrocyte suspensions at concentrations close to the physiological levels (10(-9)M). These changes might be related to the alterations of intracellular calcium concentration, as in the erythrocyte suspensions containing 10(-9)M thyroxine, intracellular calcium concentration was found to be 30 times lower than the control suspensions which did not contain thyroxine. Thyroxine also reduced the mechanical hemolysis ratio in calcium loaded cells. These observations suggest that thyroxine might play some role in the regulation of the mechanical properties of erythrocytes which might be mediated via the effects on calcium metabolism. 相似文献
46.
Violeta Datcheva Aleksei Kamernitskii Radoslav Vlahov Natalia Voishvillo Vera Levi Irina Reshetova Elena Chernoburova 《Applied microbiology and biotechnology》1986,25(1):14-17
Summary A high-yield microbiological transformation of polyfunctional 5-3-acetoxy steroids, containing an additional ring E, by Corynebacterium mediolanum strain B-964 was carried out, resulting in the corresponding 4-3-ketones. It was shown that the type of transformation and the yield of the reaction depend on the degree of saturation of the ring E and on the position of the oxygen-containing substituents in it. 相似文献
47.
Lateral heterogeneity of cell membranes has been demonstrated in numerous studies showing anomalous diffusion of membrane proteins; it has been explained by models and experiments suggesting dynamic barriers to free diffusion, that temporarily confine membrane proteins into microscopic patches. This picture, however, comes short of explaining a steady-state patchy distribution of proteins, in face of the transient opening of the barriers. In our previous work we directly imaged persistent clusters of MHC-I, a type I transmembrane protein, and proposed a model of a dynamic equilibrium between proteins newly delivered to the cell surface by vesicle traffic, temporary confinement by dynamic barriers to lateral diffusion, and dispersion of the clusters by diffusion over the dynamic barriers. Our model predicted that the clusters are dynamic, appearing when an exocytic vesicle fuses with the plasma membrane and dispersing with a typical lifetime that depends on lateral diffusion and the dynamics of barriers. In a subsequent work, we showed this to be the case. Here we test another prediction of the model, and show that changing the stability of actin barriers to lateral diffusion changes cluster lifetimes. We also develop a model for the distribution of cluster lifetimes, consistent with the function of barriers to lateral diffusion in maintaining MHC-I clusters. 相似文献
48.
Extraepitopic compensatory substitutions partially restore fitness to simian immunodeficiency virus variants that escape from an immunodominant cytotoxic-T-lymphocyte response 下载免费PDF全文
Friedrich TC Frye CA Yant LJ O'Connor DH Kriewaldt NA Benson M Vojnov L Dodds EJ Cullen C Rudersdorf R Hughes AL Wilson N Watkins DI 《Journal of virology》2004,78(5):2581-2585
Selection for escape mutant immunodeficiency viruses by cytotoxic T lymphocytes (CTL) has been well characterized and may be associated with disease progression. CTL epitopes accrue escape mutations at different rates in vivo. Interestingly, certain high-frequency CTL do not select for escape until the chronic phase of infection. Here we show that mutations conferring escape from immunodominant CTL directed against an epitope in the viral Gag protein are strongly associated with extraepitopic mutations in gag in vivo. The extraepitopic mutations partially restore in vitro replicative fitness of viruses bearing the escape mutations. Constraints on epitope sequences may therefore play a role in determining the rate of escape from CTL responses in vivo. 相似文献
49.
The selenoprotein GPX4 is essential for mouse development and protects from radiation and oxidative damage insults 总被引:19,自引:0,他引:19
Yant LJ Ran Q Rao L Van Remmen H Shibatani T Belter JG Motta L Richardson A Prolla TA 《Free radical biology & medicine》2003,34(4):496-502
Lipid peroxidation has been implicated in a variety of pathophysiological processes, including inflammation, atherogenesis, neurodegeneration, and the ageing process. Phospholipid hydroperoxide glutathione peroxidase (GPX4) is the only major antioxidant enzyme known to directly reduce phospholipid hydroperoxides within membranes and lipoproteins, acting in conjunction with alpha tocopherol (vitamin E) to inhibit lipid peroxidation. Here we describe the generation and characterization of GPX4-deficient mice by targeted disruption of the murine Gpx4 locus through homologous recombination in embryonic stem cells. Gpx4(-/-) embryos die in utero by midgestation (E7.5) and are associated with a lack of normal structural compartmentalization. Gpx4(+/-) mice display reduced levels of Gpx4 mRNA and protein in various tissues. Interestingly, cell lines derived from Gpx4(+/-) mice are markedly sensitive to inducers of oxidative stress, including gamma-irradiation, paraquat, tert-butylhydroperoxide, and hydrogen peroxide, as compared to cell lines derived from wild-type control littermates. Gpx4(+/-) mice also display reduced survival in response to gamma-irradiation. Our observations establish GPX4 as an essential antioxidant enzyme in mice and suggest that it performs broad functions as a component of the mammalian antioxidant network. 相似文献
50.
Just say no: floral repressors help Arabidopsis bide the time 总被引:1,自引:0,他引:1