共查询到20条相似文献,搜索用时 15 毫秒
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Érika V. S. Albuquerque Caroline A. Bezerra Juan V. Romero Jorge W. A. Valencia Arnubio Valencia-Jiménez Lucas M. Pimenta Aulus E. A. D. Barbosa Maria C. M. Silva Ana M. Meneguim Maria Eugênia L. Sá Gilbert Engler Janice de Almeida-Engler Diana Fernandez Maria F. Grossi-de-Sá 《Tropical plant biology》2015,8(3-4):98-107
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In the progeny after selfing of a normally open pollinated variety (L.S. 326-3) of pearl millet (Pennisetum americanum (L.) Leeke, n=7) one plant exhibited desynapsis, chromosome stickiness and high sterility. Meiosis was normal until diplotene. Thereafter, it was characterized by dissociation of bivalents into univalents and formation of nonspecific congregations of chromosomes at diakinesis, shrinkage of cytoplasm and occurrence of unoriented sticky chromatin masses at metaphase I, relaxation of stickiness, unbalanced chromosome numbers at the poles and laggards at anaphase I, and presence of other irregularities in subsequent stages. Meiosis was completed. Male and female sterility was high. This meiotic mutant thus has multiple effects and is inherited as a monogenic recessive and designated as st. 相似文献
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Many Aboriginal groups, in northern Canada and elsewhere, recognize the strong relationship between the health and well-being of people and environment. Western science, including theory and literature related to forest ecosystem management, has been slow to recognize the complex and diverse values that Aboriginal people associate with their lands and resources. Through case study research on the berry-harvesting practices of Gwich’in women from the community of Fort McPherson, Northwest Territories, Canada, we investigated the values that Teetl’it Gwich’in women associate with the land or nan kak. Nine different values, as well as a set of detailed measures, were identified during the research, including individual preference and well-being, family well-being, social connectivity, cultural continuity, land and resource use, stewardship, self-government, and spirituality. The commercial value of berries was not identified as important to women. This interdisciplinary research has the potential to contribute to several bodies of literature including that on social-ecological systems. 相似文献
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Warren Shapiro 《Anthropological Forum》2008,18(1):1-15
Basing his analysis on Kroeber's ‘The superorganic’ (1917) and ‘Eighteen professions’ (1915), Derek Freeman has put forward the notion of a ‘Boasian paradigm’, whereby Kroeber is alleged to have perpetuated the biology/culture split suggested by Boas. I argue, instead, that there is a strong innatist element in Kroeber's writings throughout his long career; and that the articles noted above need to be placed in the social and intellectual contexts of their time, particularly the encroachment of the eugenics movement on social theory and its application to immigration restriction. 相似文献
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Jeanette Edwards 《Ethnos》2018,83(4):724-743
Family history research is popular in England. As a social practice it straddles social class and is confined to neither the middle nor the working classes, but shows an enthusiastic and flourishing interest in the workings of social class and in micro-histories of the region. This article focuses on experts in family history research in a region of the north west of England where it is referred to colloquially as ‘family treeing’. Here family treeing is inflected by a post-industrial landscape and recent social and economic transformations with attendant threats to working-class life and dignity. Family treeing is about caring for the dead, but it is also, significantly, about caring for the living, and not only kin. It is an active practice of belonging both to people and places, and entails constant acts of reciprocity. 相似文献
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Peters Greg Harder Robin Arvidsson Rickard Baumann Henrikke Björklund Anna Despeisse Mélanie Ekvall Tomas Ericsson Niclas Finnveden Göran Hammar Torun Janssen Matty Karheiding Carl Karlsson Hanna Söderman Maria Ljunggren Svanström Magdalena Tillman Anne-Marie Wallbaum Holger 《The International Journal of Life Cycle Assessment》2019,24(10):1758-1759
The International Journal of Life Cycle Assessment - 相似文献
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Ashutosh Malhotra Erfan Younesi Harsha Gurulingappa Martin Hofmann-Apitius 《PLoS computational biology》2013,9(7)
Speculative statements communicating experimental findings are frequently found in scientific articles, and their purpose is to provide an impetus for further investigations into the given topic. Automated recognition of speculative statements in scientific text has gained interest in recent years as systematic analysis of such statements could transform speculative thoughts into testable hypotheses. We describe here a pattern matching approach for the detection of speculative statements in scientific text that uses a dictionary of speculative patterns to classify sentences as hypothetical. To demonstrate the practical utility of our approach, we applied it to the domain of Alzheimer''s disease and showed that our automated approach captures a wide spectrum of scientific speculations on Alzheimer''s disease. Subsequent exploration of derived hypothetical knowledge leads to generation of a coherent overview on emerging knowledge niches, and can thus provide added value to ongoing research activities. 相似文献
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Taiwan currently has one of the lowest fertility rates in the world, leading to projections of rapid population ageing and decline. In common with other territories in Pacific Asia, policies designed to support childbearing have recently been introduced. Some optimism for the future success of these policies has been drawn from the fact that the ‘ideal’ number of children stated in Taiwanese surveys is over two. In this way, Taiwan appears to fit the ‘two-child norm’ model identified for Europe and North America. Furthermore, this feature has led commentators to state that Taiwan is not in a ‘low fertility trap’–where positive feedback mechanisms emanating from the normalisation of small families, slow economic growth and ageing/declining population mean attempts to increase fertility become ever less likely to succeed. Using a recent national representative survey, and arguing that ‘intentions’ are a more reliable guide to understanding the circumstances of family formation, this paper explores fertility intentions in Taiwan with a special focus on women at parity one and parity two. This will form the first full-length examination of fertility intentions in Taiwan published in English and one of the few studies of Pacific Asia that reports a micro-level analysis. We argue that using intentions should provide a better ‘barometer’ of attitudes towards childbearing in Taiwan, and that through micro-level analysis, we can better identify the predictors of intentions that could, in turn, provide useful clues both for projections as well as shaping policy responses. While we found some evidence for a ‘two-child norm’ among childless women, this could be an unrealistic ideal. This is supported by the fact that a majority of women with one child do not intend to have another. 相似文献
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V. Dmitriev A. Tsiomenko I. Kulaev B. Fikhte 《Applied microbiology and biotechnology》1980,9(3):211-216
Summary A distinction between the chemical composition of ultrastructurally modified regions and the rest of the cell wall (canals) of the yeast Schwanniomyces occidentalis was shown by cytochemical staining of cell wall polysaccharides. The formation of canals was induced by cultivation of yeasts on hydrocarbons and was parallelled by the enhancement of -glucosidase, -glucanase and -mannosidase activities which were all capable of degrading cell wall polysaccharides. The presence of cycloheximide prevented canal formation. We assume that these hydrolases modified definite cell wall regions transforming them into canals. 相似文献
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Martin J. S. Rudwick 《Journal of the history of biology》2018,51(1):135-178
From the early nineteenth century, the successful use of fossils in stratigraphy oriented paleontology (and particularly the study of fossil invertebrates) towards geology. The consequent marginalising of biological objectives was countered in the twentieth century by the rise of ‘Paläobiologie’, first in the German cultural area and only later, as ‘paleobiology’, in the anglophone world. Several kinds of paleobiological research flourished internationally after the Second World War, among them the novel field of ‘paleoecology’. Within this field there were attempts to apply functional morphology to the problematical cases of fossil organisms, for which functions cannot be observed directly. This article describes the origins of the kind of functional inference for fossils that I proposed in 1961 as the method of ‘paradigms’ (a year before Thomas Kuhn made that word more widely familiar with a quite different meaning). Here I summarize some of my ‘worked exemplars’, which were intended to show the paradigm method in action. These case-studies were all taken from the paleontologically important phylum of the Brachiopoda, but the method was claimed to have much wider implications for the interpretation of the fossil record in terms of adaptive evolution. This article takes the history of the paradigm method as far as the late 1960s. I hope to trace, in a sequel, its ambivalent fate during the 1970s and beyond, when for example Gould’s critique of ‘the adaptationist programme’ and the rise of computer-based quantitative methods for the evolutionary interpretation of the fossil record led to the relative eclipse of functional morphology in paleontology. 相似文献
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Ulrich Demmer 《Ethnos》2015,80(1):91-116
This paper explores an understanding of the person in terms of practical reason. Based on my fieldwork among the Jenu Kurumba and on ethnographic data on four other communities, I analyse how these five communities conceptualise the ethical person. To understand these concepts, I consult studies of an anthropology of ethics concerned with practical reason. Additionally I draw on Charles Taylor's concept of the ‘agent plus’ and Alasdair MacIntyre's notion of the ‘practical reasoner’. I argue that both Neo-Aristotelian notions are fundamentally important for understanding the concepts of the ethical person among the five cultural formations investigated in this paper. 相似文献
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Gabriele Alex 《Ethnos》2013,78(4):523-543
In India, touch is a prime marker of status and social relations. Those who are impure are ‘untouchable’,1 but those who are of a relatively higher purity are also, depending on the context, either ‘untouchable’ or ‘touchable’ only under certain fixed rules. In this paper, I will explore the contexts in which body contact and touch can be part of personal relations. I describe how these body contacts signify important social relations and establish community identity. Further, I will analyse how patterns of body contact on the one hand change during childhood, and on the other hand produce changes in the status of a social persona. The last point to be investigated is the meaning of touch as a sign for public representations. 相似文献
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《Biochimica et Biophysica Acta (BBA) - Gene Regulatory Mechanisms》2020,1863(8):194564
Advances in treatment of childhood leukaemia has led to vastly improved survival rates, however some subtypes such as those characterised by MLL gene rearrangement (MLL-r), especially in infants, continue to have high relapse rates and poor survival. Natural history and molecular studies indicate that infant acute lymphoblastic leukaemia (ALL) originates in utero, is distinct from childhood ALL, and most cases are caused by MLL-r resulting in an oncogenic MLL fusion protein. Unlike childhood ALL, only a very small number of additional mutations are present in infant ALL, indicating that MLL-r alone may be sufficient to give rise to this rapid onset, aggressive leukaemia in an appropriate fetal cell context. Despite modifications in treatment approaches, the outcome of MLL-r infant ALL has remained dismal and a clear understanding of the underlying biology of the disease is required in order to develop appropriate disease models and more effective therapeutic strategies. 相似文献
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This review draws attention to information from the literature and our own observations supporting the view that higher plants and micro-organisms display an intrinsic capacity to be proactively involved in pedogenetic processes. ‘Bioengineering’ of this kind is deemed to be spearheaded by principal deep-rooted tree and shrub species and to result in optimisation of command and conservation of water and nutrients within an ecosystem. Specific examples discussed in the paper include, the formation of silicon- or iron-based linings of vertical channels and pores, binding of sand on roots, generation of organically derived hydrophobicity, development of clay-based hardpans and texture-contrast seals, precipitation of silcrete, calcrete and ferricrete pavements, effective accessing and conservation of P resources, including mining by microbes and the biological cycling of Si and Al via plants and micro-organisms. In each case, definitive roles and mechanisms are suggested for the organisms involved, particularly in relation to formative effects relating to secretion of organic acids, dispersing agents and other classes of exudate. We introduce the term ‘phytotarium’ to connote the collective outcomes of the above biotic influences in construction and maintenance of niches peculiar to specific vegetation types and then review the evidence of imprinting of soil profiles due to operation of phytotaria. Examples given relate to the lateral and vertical facies encountered in certain contemporary soil profiles and paleosols with which we are familiar and are described in a companion paper. 相似文献