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To investigate the evolutionary relationships among species of Afrotrichloris, Apochiton, Coelachyrum, Dinebra, Eleusine, Leptochloa, and Schoenefeldia of subtribe Eleusininae, a phylogeny based on DNA sequences from nine gene regions (ITS, rps16-trnK, rps3, rps16, rpoC2, rpl32-trnL, ndhF, ndhA, ccsA) is presented. Previous molecular phylogenies indicated that Coelachyrum was polyphyletic and Schoenefeldia was paraphyletic, with Afrotrichloris embedded within it. Apochiton burttii was embedded in the Coelachyrum clade paired with C. longiglume, Coelachyrumpoiflorum was placed outside of Coelachyrum and sister to Eleusine, and Schoenefeldia is paraphyletic, with its two species forming a grade sister to Afrotrichoris. Our molecular phylogeny supports recognition of a new genus, Schoenefeldiella, and a new combination, Schoenfeldiella transiens. In addition, we provide generic emendations for Coelachyrum, which now includes five species including a new combination proposed here, Coelachyrum burttii, and Eleusine, which now includes 11 species.  相似文献   

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Chronic inflammation induced by Helicobacter pylori infection is a critical factor in the development of peptic ulcer disease and gastric cancer. Central to this inflammation is the initiation of pro‐inflammatory signaling cascades within epithelial cells, in particular those mediated by two sensors of bacterial cell wall components, nucleotide‐binding oligomerization domain‐containing protein 1 (NOD1) and alpha‐protein kinase 1 (ALPK1). H pylori is, however, also highly adept at mitigating inflammation in the host, thereby restricting tissue damage and favoring bacterial persistence. H pylori modulates host immune responses by altering cytokine signaling in epithelial and myeloid cells, which results in increased proliferation of regulatory T cells and downregulation of effector T‐cell responses. H pylori vacuolating cytotoxin A (VacA) has been shown to play an important role in the dampening of immune responses and induction of immune tolerance capable of protecting against asthma. It is also possible to generate protective immune responses by immunization with various H pylori antigens or their epitopes, in combination with an adjuvant, though this for now has only been shown in mouse models. Novel non‐toxic adjuvants, consisting of modified bacterial enterotoxins or nanoparticles, have recently been developed that may not only enhance vaccine efficacy, but also help translate candidate vaccines to the clinic. This review will summarize the main discoveries in the past year regarding host immune responses to H pylori infection, as well as the design of new vaccine approaches against this infection.  相似文献   

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Indians, Markets, and Rainforests: Theory, Methods, and Analysis. Ricardo A. Godoy. New York: Columbia University Press, 2001. 274 pp.  相似文献   

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Research carried out during recent decades has revealed our genome not only to be a unique mine of information about health, disease and the human condition, but also about the origin and dispersal history of the species. In this context, the genome is simply an additional source of information about human history, epistemologically no different from other historical sources. However, media and public interpretation of genetic studies of human history are complicated by the wider connotations of genes as the determinants of hereditary features and identity. We discuss two examples of media and public fascination with the interrelated themes of history, identity and heredity, pointing out some implications of historical research using genetic data in the context of our own ongoing study of Inuit groups in Greenland and Victoria Island, Canada.  相似文献   

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1. The benzodiazepines are among the most frequently prescribed of all drugs and have been used for their anxiolytic, anticonvulsant, and sedative/hypnotic properties. Since absorption rates, volumes of distribution, and elimination rates differ greatly among the benzodiazepine derivatives, each benzodiazepine has a unique plasma concentration curve. Although the time to peak plasma levels provides a rough guide, it is not equivalent to the time to clinical onset of effect. The importance of and half-lives in the actions of benzodiazepines is discussed.2. The role of cytochrome P450 isozymes in the metabolism of benzodiazepines and in potential pharmacokinetic interactions between the benzodiazepines and other coadministered drugs is discussed.3. Buspirone, an anxiolytic with minimal sedative effects, undergoes extensive metabolism, with hydroxylation and dealkylation being the major pathways. Pharmacokinetic interactions of buspirone with other coadministered drugs seem to be minimal.4. Zopiclone and zolpidem are used primarily as hypnotics. Both are extensively metabolized; N-demethylation, N-oxidation, and decarboxylation of zopiclone occur, and zolpidem undergoes oxidation of methyl groups and hydroxylation of a position on the imidazolepyridine ring system. Zopiclone has a chiral centre, and demonstrates stereoselective pharmacokinetics. Metabolic drug–drug interactions have been reported with zopiclone and erythromycin, trimipramine, and carbamazepine. Reports to date indicate minimal interactions of zolpidem with coadministered drugs; however, it has been reported to affect the C max and clearance of chlorpromazepine and to decrease metabolism of the antiviral agent ritonavin. Since CYP3A4 has been reported to play an important role in metabolism of zolpidem, possible interactions with drugs which are substrates and/or inhibitors of that CYP isozyme should be considered.  相似文献   

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Causes of Polygyny: Ecology, Economy, Kinship, and Warfare   总被引:2,自引:0,他引:2  
We discuss and test competing explanations for polygyny based on household economics, malecentered kin groups, warfare, and environmental characteristics. Data consist of codes for 142 societies from the Standard Cross-Cultural Sample, including new codes for polygyny and environmental characteristics. An explanatory model is tested for the worldwide sample using regression analysis, and then replicated with regional samples. We obtain convergent results with two different measures of polygyny, cultural rules for men's marriages and the percentage of women married polygynously. We conclude that the best predictors of polygyny are fraternal interest groups, warfare for capture of women, absence of constraints on expansion into new lands, and environmental quality and homogeneity.  相似文献   

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Abstract

Shoshana Zuboff. In the Age of the Smart Machine: The Future of Work and Power. New York: Basic Books, 1988, 468 pp. $11.95 paperback.

George Gilder. Microcosm: The Quantum Revolution in Economics and Technology. New York: Simon &; Schuster, 1989. 426 pp. $19.95 hardcover.

Loren Baritz. The Good Life. New York: Alfred A. Knopf, Inc., 1988. 361 pp. $19.95 hardcover.

Miles Orville. The Real Thing: Imitation and Authority in American Culture, 1880–1940. Chapel Hill: University of North Carolina Press, 1989. 382 pp. $14.95 paperback.

Peter Shaw. The War Against the Intellect. Iowa City: The University of Iowa Press, 1989. 181 pp. $10.95 paperback.

Robert Alter. The Pleasures of Reading in an Ideological Age. New York: Simon &; Schuster, 1989. 250 pp. $18.95 hardcover.

Ian Crofton. A Dictionary of Art Quotations. New York: Macmillan Publishing Company, 1989. $19.95 hardcover.  相似文献   

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Conformational analysis of two pairs of synthetic cyclodipeptides formed by interaction of both side chain functional groups ( , and ) and of the main and side chains ( , and ) was achieved by the method of molecular mechanics. The energetically optimal conformational states of the molecules under study were determined. It was shown that the conformational motility of cyclic system of the compounds under study depends on the relative arrangement of the amide groups and the number of atoms in the cycle.  相似文献   

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This article began as a review of a conference, organized by Gerhard Schlosser, entitled "Modularity in Development and Evolution." The conference was held at, and sponsored by, the Hanse Wissenschaftskolleg in Delmenhorst, Germany in May, 2000. The article subsequently metamorphosed into a literature and concept review as well as an analysis of the differences in current perspectives on modularity. Consequently, I refer to general aspects of the conference but do not review particular presentations. I divide modules into three kinds: structural, developmental, and physiological. Every module fulfills none, one, or multiple functional roles. Two further orthogonal distinctions are important in this context: module-kinds versus module-variants-of-a-kind and reproducer versus nonreproducer modules. I review criteria for individuation of modules and mechanisms for the phylogenetic origin of modularity. I discuss conceptual and methodological differences between developmental and evolutionary biologists, in particular the difference between integration and competition perspectives on individualization and modular behavior. The variety in views regarding modularity presents challenges that require resolution in order to attain a comprehensive, rather than a piecemeal and fragmentary, evolutionary developmental biology. J. Exp. Zool. (Mol. Dev. Evol.) 291:116-129, 2001.  相似文献   

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Truffles are the fruiting bodies of ascomycete fungi that form underground. Truffles are globally valued, culturally celebrated as aphrodisiacs, and highly sought-after delicacies in the culinary world. For centuries, naturalists have speculated about their mode of formation, and in cultures surrounding the Mediterranean Sea, many species have been prized as a delectable food source. Truffle fruiting bodies form underground and emit a variety of volatile organic compounds (VOCs). Truffle volatiles are believed to have evolved to attract animals that disperse their spores. The main VOCs identified from truffles include sulfur compounds, such as dimethyl sulfide (DMS) and dimethyl disulfide (DMDS); in addition, 1-octen-3-ol and 2-methyl-1-propanol have been found in most truffle species. Humans use pigs and dogs trained to detect truffle VOCs in order to find these prized subterranean macrofungi. Truffles have pharmacological potential, but until more reliable cultivation methods become available their high price means they are unlikely to see widespread use as medicinals.  相似文献   

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《Cell》2022,185(6):1082-1100.e24
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