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1.
Because objects only a few molecules across are too small to be seen or touched directly, scientists approach them essentially blind and numb. Now a team of physicists, chemists, biologists, and computer scientists at the University of North Carolina, Chapel Hill, has developed a tool that restores their eyes and fingers. It's called the nanoManipulator.  相似文献   

2.
Even by American standards, the far western universities of British Columbia and Saskatchewan have been outstanding producers of scientists. Next have been the small Maritime Province universities of Acadia and Mount Allison. The larger universities in Ontario and Quebec were much lower in scientific productivity, and the Roman Catholic schools lowest of all. Nearly half of the Canadian scientists have migrated to the United States, and, of those remaining in Canada, nearly half went to Ontario. Of the mathematicians, physicists, and psychologists, considerably more than half emigrated to the United States, whereas of the biologists, geologists, and chemists, considerably more than half remained in Canada. Two-thirds of Canada's future scientists go abroad for graduate training. Teaching remains the dominant profession for the top scientists, with some trend in evidence toward government and industry.  相似文献   

3.
Koenig R 《Science (New York, N.Y.)》2000,289(5481):846b-847b
On 11 May, a criminal court in Vienna found one of Austria's most prominent political scientists, Anton Pelinka, guilty of defaming former Freedom Party leader J?rg Haider. Haider, an outspoken populist who has made questionable comments about Nazism, accused Pelinka of defaming him for asserting in an interview on Italian television in May 1999 that some Haider statements had "trivialized" Nazism. In the 3 months since the judgment, an array of academic and human rights groups have rushed to Pelinka's defense.  相似文献   

4.
Bisby FA 《Science (New York, N.Y.)》2000,289(5488):2309-2312
The massive development of biodiversity-related information systems on the Internet has created much that appears exciting but chaotic, a diversity to match biodiversity itself. This richness and the arrays of new sources are counterbalanced by the maddening difficulty in knowing what is where, or of comparing like with like. But quietly, behind the first waves of exuberance, biologists and computer scientists have started to pull together in a rising tide of coherence and organization. The fledgling field of biodiversity informatics looks set to deliver major advances that could turn the Internet into a giant global biodiversity information system.  相似文献   

5.
The production of functional female gametes is essential for the propagation of all vertebrate species. The growth of oocytes within ovarian follicles and their development to mature eggs have fascinated biologists for centuries, and scientists have long realized the importance of the ovarian follicle's somatic cells in nurturing oogenesis and delivering the oocyte to the oviduct by ovulation. Recent studies have revealed key roles of the oocyte in folliculogenesis and established that bidirectional communication between the oocyte and companion somatic cells is essential for development of an egg competent to undergo fertilization and embryogenesis. The challenge for the future is to identify the factors that participate in this communication and their mechanisms of action.  相似文献   

6.
The National Science Foundation (NSF) is struggling to find a formula to boost careers of women scientists. With targeted programs a political no-no, NSF is betting that letting everyone participate will mean greater progress for women. But its latest moves have divided agency ranks and raised concern among activists.  相似文献   

7.
农业科研单位青年科技人员思想政治工作初探   总被引:1,自引:0,他引:1  
思想政治工作是党的建设工作的重要法宝,充分体现了党组织的统领全局作用和凝聚作用。随着农业体制机制改革的日益深入,农业科研单位正经历着复杂而又深刻的改革,同时,青年科技人员的思想也在悄然变化。农业科技创新归根到底取决于青年科技人员,面对青年科技工作者新的思想动态、精神状态的变化,必须开展有效的思想政治工作,以帮助青年科技人员树立正确的思想信念,克服错误的思想倾向,为深入推进农业科研单位健康、协调发展提供强大的精神正能量。  相似文献   

8.
Pennisi E 《Science (New York, N.Y.)》2000,288(5475):2304-2307
The race is over. On 26 June, to much fanfare, two rival teams announced that they had each completed a version of the "book of life"--a rough draft of the complete human genetic code. So what, exactly, is in these two different volumes, and how will they fine-tune it so that everyone from workaday biologists to pharmaceutical giants can mine its gold?  相似文献   

9.
Insect juvenile hormones are metabolized in numerous species of caterpillars by low abundance, highly specific esterases. Because of their role in regulating and possibly disrupting juvenile hormone titer and thus insect metamorphosis, they are of interest to developmental biologists as well as scientists interested in selective insect control. However, the enzymes have defied attempts to purify and characterize them. Juvenile hormone esterase activity can be inhibited by a variety of 3-substituted 1,1,1-trifluoropropanone sulfides. These apparent transition state analogs were used as ligands and eluting agents to purify juvenile hormone esterase from four insect species from 500-fold to over 1000-fold in high yield. After elution from the affinity column, the enzymes were radiolabeled with paraoxon and analyzed by electrophoresis, and the results demonstrate a high degree of purity. Transition state analogs may be useful for the affinity purification of other enzymes.  相似文献   

10.
文章简要阐述了离退休科研人员在基层农业科研单位中发挥作用的重要性,并通过分析目前基层农业科研单位中离退休科研人员发挥作用的现状,提出了要通过采取政治上关心、工作上支持、生活上照顾、精神上激励等途径发挥离退休科技人员的作用。  相似文献   

11.
Pennisi E 《Science (New York, N.Y.)》2000,290(5499):2055-2057
Arabidopsis thaliana is not just for plant biologists anymore. A few intrepid ecologists and evolutionary biologists are now touting its merits as a system in which to study the genetic basis of the traits they study. The newly completed genome sequence is allowing researchers to connect the genotype--an organism's particular mix of genes--with its phenotype--how that organism develops and acts--in ways that have not been possible in other organisms whose genetics are not as well known.  相似文献   

12.
The availability of human embryonic stem cell lines provides an important tool for scientists to explore the fundamental mechanisms that regulate differentiation into specific cell types. When more is known about the mechanisms that govern these processes, human embryonic stem cells may be clinically useful in generating cell types that have been damaged or depleted by a variety of human diseases. The NIH is actively pursuing a variety of initiatives to promote this developing research field, while continuing and expanding its long-standing investment in adult stem cells and research.  相似文献   

13.
Pennisi E 《Science (New York, N.Y.)》2000,290(5499):2054-2055
An international consortium announced this week that it has finished the first genome sequence of a higher plant. For plant biologists, the eagerly awaited genome of this small weed, Arabidopsis thaliana, offers a window into the genetic makeup of all plants, including key crops. And it's a clear window indeed, as the six international sequencing teams on three continents have produced a genome sequence that is more complete than that of any multicellular organism which has been published to date. Through this window, they are seeing for the first time that plants may be much more complex than many biologists have imagined.  相似文献   

14.
Experts on brain-riddling spongiform diseases have grown steadily more uneasy over signs that so-called mad cow disease or bovine spongiform encephalopathy (BSE), which is linked to a lethal human illness, may be lurking in sheep. A study in the 10 August issue of Nature now offers evidence that BSE is not rampant in sheep after all, although scientists are far from ready to let their guard down.  相似文献   

15.
The aim of this paper is to make possible dialogue between those who claim that technologies are coded with social, political, or ethical values and those who argue that they are value-neutral. To demonstrate the relevance of this bridge-building project, the controversy regarding agrifood biotechnology will be used as a case study. Drawing on work by L. H. Nelson about the nature of human knowledge-building enterprises and E. F. Kittay’s account of the relationally-constituted self, the argument will be made that all technologies embody the values of the communities that created them. Zahra Meghani is an assistant professor in the Department of Philosophy at the University of Rhode Island. Her research interests are philosophy of technology, feminist theory (especially feminist epistemology and feminist philosophy of science), normative ethics, practical ethics (especially health care ethics), disability issues, and political theory.  相似文献   

16.
Graham A 《Science (New York, N.Y.)》2000,290(5498):1904-1905
Although the development of the inner ear has been a favorite subject for biologists to study, it is not yet clear exactly which molecules are involved in the induction of the otic placode, the plug of embryonic ectoderm that will become the inner ear. In his Perspective, Graham takes us on an inner ear odyssey, explaining how the signaling molecules FGF-19 and Wnt-8c cooperate to induce formation of the otic placode (Ladher et al.).  相似文献   

17.
田凌  林毅 《现代农业科技》2010,(9):27-28,30
伴孢晶体蛋白是苏云金芽孢杆菌等少数芽孢杆菌在形成芽孢的同时形成的碱溶性蛋白晶体,它对约200种昆虫尤其是鳞翅目的幼虫有杀伤作用,最近人们发现某些菌株的伴孢晶体蛋白存在抗癌活性。概述了伴孢晶体的一般性结构,着重对PS2(Parasporin-2)的抗癌的分子机制进行了深入地剖析,并就研究中存在的问题和发展趋势进行了讨论。  相似文献   

18.
Complexity of coupled human and natural systems   总被引:12,自引:0,他引:12  
Integrated studies of coupled human and natural systems reveal new and complex patterns and processes not evident when studied by social or natural scientists separately. Synthesis of six case studies from around the world shows that couplings between human and natural systems vary across space, time, and organizational units. They also exhibit nonlinear dynamics with thresholds, reciprocal feedback loops, time lags, resilience, heterogeneity, and surprises. Furthermore, past couplings have legacy effects on present conditions and future possibilities.  相似文献   

19.
The existence of the National Radio Astronomy Observatory and the researches already accomplished there are the result of the foresight and wisdom of United States scientists, the National Science Board, and the Congress, who joined forces to make possible this new national asset. Continued effort will be needed td insure that the observatory will always have the finest possible research instruments and that the site will be a haven of radio quiet. Visiting scientists in some instances may wish to bring equipment with them for studying special problems. Within its means, the observatory will provide supporting facilities, including receivers and other electronic devices, computers, laboratories and shops, and housing. Scientists interested in more details concerning arrangements for visitors should direct their inquiries to the National Radio Astronomy Observatory, P. O. Box 2, Green Bank, West Virginia.  相似文献   

20.
The Lawrence Radiation Laboratory, one of the nation's most distinguished scientific institutions, has been struck by a series of "free speech" controversies in recent months. The laboratory, which is operated by the University of California and is almost entirely funded by the Atomic Energy Commission, has facilities in two California locations, Berkeley and Livermore. Each has been under fire for allegedly stifling open discussion of controversial issues. The Berkeley facility, a leading center for the study of high-energy physics and fundamental nuclear science, has been split by an internal debate over the right of scientists to hold formal political discussions at the laboratory during their lunch hours. The controversy has led to the banning of meetings, the circulating of petitions and counterpetitions bearing hundreds of names, the publishing of an underground newspaper, and the suspension of a controversial physicist. The Livermore facility, a major center for developing nuclear weapons, has been accused of trying to muzzle two staff scientists who contend that existing radiation standards are too lax to protect the public from nuclear radiation hazards. Livermore has also been the target of demonstrations and of a lawsuit seeking to open the weapons laboratory to allow discussions between outsiders and staff scientists concerning the implications of weapons research. The article below discusses the controversy at the Berkeley laboratory, where only unclassified research is performed. A subsequent article will discuss the conflict at security-conscious Livermore.  相似文献   

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