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131.
Beyond its role as an electron acceptor in aerobic respiration, oxygen is also a key effector of many developmental events. The oxygen‐sensing machinery and the very fabric of cell identity and function have been shown to be deeply intertwined. Here we take a first look at how oxygen might lie at the crossroads of at least two of the major molecular pathways that shape pancreatic development. Based on recent evidence and a thorough review of the literature, we present a theoretical model whereby evolving oxygen tensions might choreograph to a large extent the sequence of molecular events resulting in the development of the organ. In particular, we propose that lower oxygenation prior to the expansion of the vasculature may favour HIF (hypoxia inducible factor)‐mediated activation of Notch and repression of Wnt/β‐catenin signalling, limiting endocrine cell differentiation. With the development of vasculature and improved oxygen delivery to the developing organ, HIF‐mediated support for Notch signalling may decline while the β‐catenin‐directed Wnt signalling is favoured, which would support endocrine cell differentiation and perhaps exocrine cell proliferation/differentiation.  相似文献   
132.
Sexual selection has driven the evolution and elaboration of a wide variety of displays and ornaments in male nonhuman primates, including capes, cheek flanges, and sexual coloration. Among the most sexually dimorphic of all primates is the drill (Mandrillus leucophaeus), the males of which can be 3 times the mass of females, possess large canines, and exhibit extremely bright sexual skin coloration. However, the function of male coloration in this species has never been examined. Here, we present data on male color (measured objectively using digital photography), dominance rank, measures of male-female association, and key sexual behaviors, of adult male drills (n = 17) living in four semi free-ranging enclosures at the Drill Rehabilitation and Breeding Center in Nigeria. We test the hypothesis that male coloration is a badge of status, indicating dominance rank, and the hypothesis that male coloration attracts females. We found that male coloration did indicate rank, and that high ranking, strongly colored males were more likely to associate with adult females, and more specifically with fully tumescent females. These males also engaged in more sexual activity. However, measures of male-female association and sexual behaviors were not related to male color once rank had been taken into consideration; i.e., for males of a given rank, females did not prefer those that were more colorful. We discuss the results in light of what is known about the wild drill social system, in which unfamiliar individuals may come together in “supergroups,” and in which quality indicators of competitive ability may be particularly important.  相似文献   
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Backgound  

It has been reported that Toll-like receptor 4 (TLR4) deficiency reduces infarct size after myocardial ischemia/reperfusion (MI/R). However, measurement of MI/R injury was limited and did not include cardiac function. In a chronic closed-chest model we assessed whether cardiac function is preserved in TLR4-deficient mice (C3H/HeJ) following MI/R, and whether myocardial and systemic cytokine expression differed compared to wild type (WT).  相似文献   
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Media, and particularly TV media, have a great impact on the general public. In recent years, spatial patterns of information and the relevance of intangible geographies have become increasingly important. Gatekeeping plays a critical role in the selection of information that is transformed into media. Therefore, gatekeeping, through national media, also co-forms the generation of mental maps. In this paper, correspondence analysis (a statistical method) combined with cloud lines (a new visual analytics technique) is used to analyze how individual major regional events in one of the post-communist countries, the Czech Republic, penetrate into the media on a national scale. Although national news should minimize distortions about regions, this assumption has not been verified by our research. Impressions presented by the media of selected regions that were markedly influenced by one or several events in those regions demonstrate that gatekeepers, especially news reporters, functioned as a filter by selecting only a few specific, and in many cases, unusual events for dissemination.  相似文献   
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ADHD is a neurodevelopmental syndrome that often persists into adulthood. It is possible that different criteria are necessary for older adults than younger adults: the manifestations of ADHD could change with age; other conditions with onset in later life share presenting symptoms with ADHD; different contextual challenges and patterns of compensatory support may exist. For these reasons, we reviewed evidence for the validity of DSM ADHD criteria in adulthood for individuals over the age of 50. Specifically, we evaluated evidence that the DSM criteria for ADHD identify a valid syndrome in older adults based on clinical presentation, laboratory or testing findings, absence of alternate diagnosis to explain symptoms, course of the syndrome, or familial presence of the condition. We found evidence that various ADHD criteria identify subjects with clinical presentations similar to that seen in younger adults, but only 92 well-described cases have been reported in the literature. ADHD traits also may be less common in the general population of older adults than in younger adults, suggesting that the threshold for an atypical burden of ADHD traits may be lower in older populations. Future research can establish a richer basis for validity of diagnostic criteria for ADHD in older adults.  相似文献   
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The need for selection of the optimal material for the manufacturing of cardio-patches can be resolved by the use of cryostored autologous pericardial tissue. This short communication is a concise fragment of a large-scale research and demonstrates only the efficiency of cell culturing before and after pericardial preservation in the low temperature conditions.  相似文献   
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