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The origin of laboratory animal science was called forth by violent development of experimental biology and medicine in the XIX century on the one hand, and on the other hand by the necessity to have standard healthy animals for experiments with strictly definite biological characteristics. With this aim in view management technology and animal use in experiments have been constantly improved. "Laboratory animal" notion has been formed by the end of the XIX century. At the beginning of laboratory animal science development ethical problems were not as urgent as they are now. It is established that the three Rs bioethical conception of W.M.S. Russel and R.L. Burch (1959) has influence on modern state and perspectives of the development of animal experimental methods. It is shown that the existence of laboratory animal protection laws and the reflection in them of compulsory ethical review of scientific project and statistics of used laboratory animals is absolutely necessary.  相似文献   

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Ecology has often been characterized as an immature scientific discipline. This paper explores some of the sources of this alleged immaturity. I argue that the perception of immaturity results primarily from the fact that historically ecologists have based their work upon two very different approaches to research.  相似文献   

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This paper analyses the origins of the Spemann-Mangold organizer concept of 1924 in relation to his earlier background and concepts. It traces the consequences and fate of the organizer, and related concepts (embryonic induction, gradients, fields) through subsequent phases in the evolution of developmental biology up to the present, primarily from a UK perspective, but also in the USA. The origins of Wolpert's concept of positional information of around 1970 are analysed; this markedly different model of embryogenesis effectively took the place of the organizer, following on from a generally assumed out-datedness of the corpus of Spemann's data and concepts. Explanations in terms of historical forces are suggested; events are seen as a historical causal chain. A crucial factor appears to have been the long-term neglect of morphogenetic cell movement as an integral component of an adequate induction-based model. The paper discusses the general inter-relation of history and science, and particularly the implications for current scientific practice, including the potential for conceptual distortions due to historical factors. It is argued that historical considerations need to be included as part of the use and critical assessment of basic concepts in science.  相似文献   

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African and Asian perspectives on the origins of modern humans.   总被引:3,自引:0,他引:3  
The ways in which the cultural evidence - in its chronological context - can be used to imply behavioural patterning and to identify possible causes of change are discussed. Improved reliability in dating methods, suites of dates from different regional localities, and new, firmly dated fossil hominids from crucial regions such as northeast Africa, the Levant, India and China, are essential for clarification of the origin and spread of the modern genepool. Hominid ancestry in Africa is reviewed, as well as the claims for an independent origin in Asia. The cultural differences and changes within Africa, West and South Asia and the Far East in the later Middle and early Upper Pleistocene are examined and compared, and some behavioural implications are suggested, taking account of the evolutionary frameworks suggested by the 'multiregional evolution' and 'Noah's Ark' hypotheses of human evolution. A possible explanation is proposed for the cultural differences between Africa, West Asia and India on the one hand, and southeast Asia and the Far East on the other. The apparent hiatus between the appearance of the first anatomically modern humans, ca. 100 ka ago, and the appearance of the Upper Palaeolithic and other contemporaneous technological and behavioural changes around 40 ka ago, is discussed. It is suggested that the anatomical changes occurred first, and that neurological changes permitted the development of fully syntactic language some 50 ka later. The intellectual and behavioural revolution, best demonstrated by the 'Upper Palaeolithic' of Eurasia, seems to have been dependent on this linguistic development - within the modern genepool - and triggered the rapid migration of human populations throughout the Old World.  相似文献   

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We applied a paleoimmunological investigation, using an immunoenzymatic assay revealing trophozoite derived Plasmodium falciparum histidine rich protein-2 antigen (PfHRP-2). The investigation was carried out on skin, muscle and bone samples. We examined predynastic egyptian mummies (3200 B.C.) from Gebelen, belonging to the Marro's Collection of the Anthropological and Ethnographic Museum of Turin, to assay the presence of malaria. The results obtained suggest an incidence of malaria of about 40% in the mummies of Gebelen group. Data are compatible with other observations effected on populations living in similar ecological conditions of malarial areas.  相似文献   

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Behavioral modernity is considered one of the defining characteristics separating modern humans from earlier hominin lineages. Over the course of the past two decades, the nature and origins of modern human behavior have been among the most debated topics in paleoanthropology. 1 - 7 There are currently two primary competing hypotheses regarding how and when modern human behavior arose. The first one, which we shall term the saltational model, argues that between 50–40 kya modern human behavior appeared suddenly and as a “package”; that is, the entire range of traits appeared more or less simultaneously. The proposed reason most often cited for this sudden change in behavior is a genetic mutation, possibly related to communication, 7 that occurred around 50 kya. The second major hypothesis, which we shall term the gradualistic model, argues that modern human behavior arose slowly and sporadically over the course of the past 150,000 years and may be related to increasing population pressure. 2 In general, many European scholars subscribe to the saltational model, while many Africanists seem to prefer the gradualistic model. As McBrearty and Brooks 2 noted, the disagreement may be related to different developmental histories underlying the research traditions in Europe and Africa.  相似文献   

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Some scientific-organizational problems of coordinating work within the framework of CMEA and the perspectives of further unification of hygienic standards of chemical factors in industrial environment are expounded.  相似文献   

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Twenty years of research into medicinal plants: Results and perspectives   总被引:1,自引:0,他引:1  
Over the years 1981 to 2001 there has been a rapid evolution of research into medicinal plants. The major improvement has been the introduction of simple and predictive bioassays for bioactivity-guided isolation. Radical developments in separation methods have also taken place. Another important addition has been the development of hyphenated techniques involving HPLC: LC/UV, LC/MS, LC/MSn and LC/NMR. These are indispensable nowadays for the early detection and identification of new compounds in crude plant extracts. Hyphenated techniques allow an efficient targeted isolation approach for the discovery of new lead compounds. Other areas of increasing importance include the investigation of toxic constituents of plants and phytomedicines, and the effects of genetic modifications on plant secondary metabolites. This revised version was published online in June 2006 with corrections to the Cover Date.  相似文献   

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The domestic and foreign literature on microbiological studies in outer space from 1935 through 1970 is reviewed, with separate references to results obtained with balloons, high-altitude rockets and artificial earth satellites. The results of most experiments warrant the conclusion that spaceflight factors do not interfere with growth, development, cellular and nuclear division or mutagenesis in microorganisms, nor exert a modifying action on the radiation effect. In those cases when effects are observed they are as a rule attributed not to spaceflight factors but to differences in the maintenance conditions of the control and flight series of microorganisms in the period from their shipping from the laboratory till their return for study. One exception are the experiments carried out on twelve spacecraft by Zhukov-Verezhnikov and his co-workers in the U.S.S.R. and the experiment performed on Bios 2 by Mattoni in the U.S.A. These studies show that spaceflight factors appear to affect the subcellular processes in the lysogenic bacteriaE. coli andSalmonella typhimurium. The evidence obtained by Soviet investigators indicates that bacteria exhibit increased phage production. Mattoni's experiments show that spaceflight factors reduce or repress the phage production of lysogenic bacteria even under in-flight exposure to γ rays in doses of 265, 645 and 1640 rad. Both those two groups of results are statistically significant and appear to be true to fact. However, it is difficult as yet to give preference to any of them and to explain the differences observed. From a theoretical view-point, of greatest interest is the study of the mechanism leading to impairment of subcellular processes in bacteria (be it induction or repression) reproduced in weightlessness. It is concluded that it is desirable that microbiological studies in outer space should employ only those microorganisms that have received a detailed study in physiological, cytological, biochemical and genetic aspects. Three problem areas are formulated to be concentrated on by space microbiology: (1) Study of bacterial growth in weightlessness; (2) Study of chromosome-episome interaction in bacteria during development in weightlessness; and (3) Elucidation of the selective role of weightlessness in populations of microorganisms. The authors believe that in general the so-called problem of the ‘effects of spaceflight factors on microorganisms’ no longer exists at the present time. For that reason, experiments with microorganisms in outer space should have a specific, clearly formulated objective.  相似文献   

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中国植物内生微生物研究的发展和展望   总被引:7,自引:0,他引:7  
我国植物内生微生物的早期研究论文,基本上以非豆科植物根瘤菌Frankia属细菌为主。进入21世纪后,植物内生菌的研究,无论是研究领域的扩大,研究人员的增加,还是论文数量的递增都有了迅猛的发展,为国际上少有。我国植物内生微生物的研究具有资源探索多、分离培养多、活性检测多、活性物质功能研究多;方法研究少、涉及林木少、与宿主的关联少、实际应用少等特点。其研究主要集中在红豆杉类、红树类、鬼臼类、兰、银杏等植物中的内生微生物。论文的发表以药物开发为研究目标的最多,又以初级的资源探索型为最。以抗菌、抗肿瘤等指标为主的药物开发,是植物内生微生物研究中最耀眼的亮点,目前已获得了紫杉醇生产效率较高的内生真菌菌株资源。我国植物内生微生物研究有4大类24个应用研究的方向,其中特别值得关注的是豆科植物根瘤内生细菌的研究;尚待加强的有6个方面,尤其是深色有隔内生真菌(DSE)的研究。我国植物内生微生物研究在药用植物内生微生物的资源探索和筛选方面积累较丰富,而在有害内生微生物方面的研究则比较薄弱。最后,作者提示了一些尚待加强的研究技术,供相关人员参考。  相似文献   

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Scabies, a mite infestation frequently sexually transmitted, dates back to antiquity but remains a challenging parasite for study in clinical practice and community settings. Its history is one of centuries of slow progress to recognize the mite and to finally establish its nexus to the clinical syndrome of pruritis with several protean manifestations and different epidemiological patterns. Contemporary methods of management are briefly reviewed, with the future promise of improved evolutionary knowledge associated with the advent of molecular and genetic technology. Current information indicates that humans and earlier protohumans were most likely the source of animal scabies, first of dogs, and later of other species with subsequent spread to wildlife. Morphologically identical variants of Sarcoptes scabiei are nonetheless host specific, as determined by recent DNA studies, and invite future investigations into the dynamics of this troublesome sexually transmissible agent, with the goal of improved recognition and control.  相似文献   

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Six studies in this special issue dealt with modern nannoplankton assemblages. In total during these studies 552 samples were analysed and about 180,000 specimens identified, from 152 species. This paper provides a unified list of taxa from these studies, records the presence/absence of each species across the studies and indicates the more common species. Comparison of results indicates a high level of consensus on taxonomy and a high commonality of the floras.  相似文献   

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