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The actinobacteria are arguably the richest source of small molecule diversity on the planet. These compounds have an incredible variety of chemical structures and biological activities (in nature and in the laboratory). Their potential for the development of therapeutic applications cannot be underestimated. It is suggested that an improved understanding of the biological roles of low molecular weight compounds in nature will lead to the discovery an inexhaustible supply of novel therapeutic agents in the next decade. To support this objective, a functional marriage of biochemistry, genomics, genetics, microbiology, and modern natural product chemistry will be essential.  相似文献   

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An association of limnic ostracodes has been discovered in the upper part of the Irbzer Formation, of Maastrichtian age, in the Moroccan Middle-Atlas. A new species is described, Gomphocythere achloujensis nov. sp. Paracandona occitanica, which is very common in terminal Cretaceous non-marine deposits of southern Europe (France, Spain), is found for the first time on the south Tethyan margin.  相似文献   

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The article describes the documentary vicissitudes of young Gambian men of Soninke ethnicity. Normally the most mobile subjects in a milieu where international migration is central to subsistence and prosperity, these young men often fail to secure entry visas to the West and other desirable destinations owing to restrictive admission policies. Would‐be travellers cope with high rejection rates, but also struggle to secure financial and logistical support from relatives in order to meet the demanding requirements of visa applications. Since kinship mediates access to travel documents, the article suggests that visa ineligibility is a product of both state‐based and societal practices of certification. It shows how the visa regime plays into the kinship reciprocities and affects that produce, discipline, and select prospective migrants, thereby transferring and concealing the arbitrariness and uncertainty of legal‐political structures of mobility.  相似文献   

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Eric Reitan 《Bioethics》2016,30(4):272-281
One reason for the persistent appeal of Don Marquis' ‘future like ours’ argument (FLO) is that it seems to offer a way to approach the debate about the morality of abortion while sidestepping the difficult task of establishing whether the fetus is a person. This essay argues that in order to satisfactorily address both of the chief objections to FLO – the ‘identity objection’ and the ‘contraception objection’ – Marquis must take a controversial stand on what is most essential to being the kind of entity that an adult human being is. Such a stand amounts to a controversial account of personhood. To the extent that FLO's success depends on accepting such a controversial metaphysical view, one apparent attraction of FLO proves illusory.  相似文献   

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The anti-tuberculosis BCG (Bacille Calmette-Guérin) vaccine was conceived and developed between 1905 and 1921 at Pasteur Institutes in France. Between 1921 and A. Calmette’s death in 1933, the vaccine went through a first period of national and international production and distribution for its use in humans. In France these activities were exclusively carried out by Calmette and his collaborators at the Pasteur Institute in Paris. Initially improvised production in a small room in the cellar gave way in 1931 to the construction of the spacious and magnificent ‘New laboratories for research on tuberculosis and the preparation of the BCG’ within the premises of the Pasteur Institute. Presentation and image-building of the vaccine in France insisted on the fact that the BCG was not a commercial specialty but distributed free of charge. The technical monopoly of its production nevertheless lay with the Paris Pasteur Institute and standardization of scientific proof of safety, efficacy and stability was dominated by that Institute in France. In contrast, the international production and distribution of the vaccine was entrusted and transferred, free of charge, to trustworthy laboratories outside France. Multiplication of producers and users led to an increased need for standardization. For this process the analysis distinguishes between the standardization of scientific proof concerning safety, efficacy and stability of the vaccine and standardization of its medical uses. Whereas standardization was rather successful in the inter-war period in France, the international efforts remained rather unsuccessful. Only after world war II under Scandinavian leadership and in the context of mass vaccination programs supported by the WHO and UNICEF was the international standardization effectively implemented and succeeded at least to some extend.  相似文献   

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The COVID‐19 epidemic is one of the most influential epidemics in history. Understanding the impact of coronaviruses (CoVs) on host cells is very important for disease treatment. The SARS‐CoV‐2 envelope (E) protein is a small structural protein involved in many aspects of the viral life cycle. The E protein promotes the packaging and reproduction of the virus, and deletion of this protein weakens or even abolishes the virulence. This review aims to establish new knowledge by combining recent advances in the study of the SARS‐CoV‐2 E protein and by comparing it with the SARS‐CoV E protein. The E protein amino acid sequence, structure, self‐assembly characteristics, viroporin mechanisms and inhibitors are summarized and analyzed herein. Although the mechanisms of the SARS‐CoV‐2 and SARS‐CoV E proteins are similar in many respects, specific studies on the SARS‐CoV‐2 E protein, for both monomers and oligomers, are still lacking. A comprehensive understanding of this protein should prompt further studies on the design and characterization of effective targeted therapeutic measures.  相似文献   

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Ostracode assemblages, collected in the continental “Red Beds” of the Central High Atlas, Morocco, consist of 35 species, belonging to 17 genera, four of which are new and described herein. They allow to assign the lower member of the Iouaridène formation to the Upper Jurassic (?)-Upper Hauterivian and the Jbel Sidal formation to the Upper Hauterivian-Lower Aptian. Ostracode assemblages characterize lacustrine (freshwater) and lagoonal (oligo to mesohaline) environments. On the basis of limnic and lagoonal species, faunal connections are proposed for the Barremian-Aptian between Morocco and the Iberian Peninsula.  相似文献   

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Evidence of grand burials and monumental construction is a striking feature in the archaeological record of the Upper Palaeolithic period, between 40 and 10 kya (thousand years ago). Archaeologists often interpret such finds as indicators of rank and hierarchy among Pleistocene hunter‐gatherers. Interpretations of this kind are difficult to reconcile with the view, still common in sociobiology, that pre‐agricultural societies were typically egalitarian in orientation. Here we develop an alternative model of ‘Palaeolithic politics’, which emphasizes the ability of hunter‐gatherers to alternate – consciously and deliberately – between contrasting modes of political organization, including a variety of hierarchical and egalitarian possibilities. We propose that alternations of this sort were an emergent property of human societies in the highly seasonal environments of the last Ice Age. We further consider some implications of the model for received concepts of social evolution, with particular attention to the distinction between ‘simple’ and ‘complex’ hunter‐gatherers.  相似文献   

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This article analyses revolutionary social change by exploring how people attempt to create a radically different future by taking action in the present, and the challenges that beset this transformation. Examining the relationship between the future, the present, and the past, the article takes the case of the spread of armed underground Maoist guerrillas in India to ask two questions: First, why does India hang on to this form of utopianism when the rest of the world appears to have abandoned it? Second, how and why does the ‘muck of the past’ influence the production of a radically different future? In answering these questions, this article suggests that for both processes of radical social change and our theories of them, we need to reinsert our analyses of politico‐economic conditions into our ideologies of social change.  相似文献   

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