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1.
Streaming teaching is adopted gradually for non-English majors in some vocational & technological colleges,and in this thesis the advantages and problems of the method are discussed according to the teaching practice.Furthermore,as a consideration of the streaming teaching,much more progress is expected to be made in the future English teaching with the help of the thesis. 相似文献
2.
Rosiane Serrano Luis Henrique Rodrigues Daniel Pacheco Lacerda Priscila Bonalume Paraboni 《Systemic Practice and Action Research》2018,31(5):509-537
Industrial sectors that operate in uncertain environments - with demand variability, product seasonality and different industrialisation structures - need studies that enable identification and forecast trends. Therefore, the development of competitiveness extends beyond a company’s individual performance. Collective action, whether toward consumer markets, supplier markets, competitors and substitutes, can reinforce or help reformulate the current practices of an organisation, besides providing better results in the development of strategies and competitive positioning. Thus, clothing, the sector addressed in this work, is characterised by a long, fragmented, heterogeneous production chain, the competitiveness of which is linked to product differentiation. Therefore, the use of systemic approaches to study this sector is effective. In this sense, this research aims at adapting Systems Thinking and Scenario Planning (STSP) so that it supports the development and planning process in a given sector. Thus, this research applies STSP adapted to an analysis of the clothing sector in the northern region of Rio Grande do Sul State, Brazil. As a result, in academic terms, this research proposed and validated a method for analysing industrial sectors of the clothing industry. In the sectoral context, this research identified elements that leverage the sector’s competitiveness, besides generating knowledge and learning aimed at strengthening the sectoral structure identified, and fostering the formation of a new clothing cluster. 相似文献
3.
The timing of action potentials relative to sensory stimuli can be precise down to milliseconds in the visual system, even though the relevant timescales of natural vision are much slower. The existence of such precision contributes to a fundamental debate over the basis of the neural code and, specifically, what timescales are important for neural computation. Using recordings in the lateral geniculate nucleus, here we demonstrate that the relevant timescale of neuronal spike trains depends on the frequency content of the visual stimulus, and that 'relative', not absolute, precision is maintained both during spatially uniform white-noise visual stimuli and naturalistic movies. Using information-theoretic techniques, we demonstrate a clear role of relative precision, and show that the experimentally observed temporal structure in the neuronal response is necessary to represent accurately the more slowly changing visual world. By establishing a functional role of precision, we link visual neuron function on slow timescales to temporal structure in the response at faster timescales, and uncover a straightforward purpose of fine-timescale features of neuronal spike trains. 相似文献
4.
Persistence of soil organic matter as an ecosystem property 总被引:65,自引:0,他引:65
Schmidt MW Torn MS Abiven S Dittmar T Guggenberger G Janssens IA Kleber M Kögel-Knabner I Lehmann J Manning DA Nannipieri P Rasse DP Weiner S Trumbore SE 《Nature》2011,478(7367):49-56
Globally, soil organic matter (SOM) contains more than three times as much carbon as either the atmosphere or terrestrial vegetation. Yet it remains largely unknown why some SOM persists for millennia whereas other SOM decomposes readily--and this limits our ability to predict how soils will respond to climate change. Recent analytical and experimental advances have demonstrated that molecular structure alone does not control SOM stability: in fact, environmental and biological controls predominate. Here we propose ways to include this understanding in a new generation of experiments and soil carbon models, thereby improving predictions of the SOM response to global warming. 相似文献
5.
The genome sequence of the rice blast fungus Magnaporthe grisea 总被引:8,自引:0,他引:8
Dean RA Talbot NJ Ebbole DJ Farman ML Mitchell TK Orbach MJ Thon M Kulkarni R Xu JR Pan H Read ND Lee YH Carbone I Brown D Oh YY Donofrio N Jeong JS Soanes DM Djonovic S Kolomiets E Rehmeyer C Li W Harding M Kim S Lebrun MH Bohnert H Coughlan S Butler J Calvo S Ma LJ Nicol R Purcell S Nusbaum C Galagan JE Birren BW 《Nature》2005,434(7036):980-986
Magnaporthe grisea is the most destructive pathogen of rice worldwide and the principal model organism for elucidating the molecular basis of fungal disease of plants. Here, we report the draft sequence of the M. grisea genome. Analysis of the gene set provides an insight into the adaptations required by a fungus to cause disease. The genome encodes a large and diverse set of secreted proteins, including those defined by unusual carbohydrate-binding domains. This fungus also possesses an expanded family of G-protein-coupled receptors, several new virulence-associated genes and large suites of enzymes involved in secondary metabolism. Consistent with a role in fungal pathogenesis, the expression of several of these genes is upregulated during the early stages of infection-related development. The M. grisea genome has been subject to invasion and proliferation of active transposable elements, reflecting the clonal nature of this fungus imposed by widespread rice cultivation. 相似文献
6.
HIV preferentially infects HIV-specific CD4+ T cells 总被引:34,自引:0,他引:34
Douek DC Brenchley JM Betts MR Ambrozak DR Hill BJ Okamoto Y Casazza JP Kuruppu J Kunstman K Wolinsky S Grossman Z Dybul M Oxenius A Price DA Connors M Koup RA 《Nature》2002,417(6884):95-98
HIV infection is associated with the progressive loss of CD4(+) T cells through their destruction or decreased production. A central, yet unresolved issue of HIV disease is the mechanism for this loss, and in particular whether HIV-specific CD4(+) T cells are preferentially affected. Here we show that HIV-specific memory CD4(+) T cells in infected individuals contain more HIV viral DNA than other memory CD4(+) T cells, at all stages of HIV disease. Additionally, following viral rebound during interruption of antiretroviral therapy, the frequency of HIV viral DNA in the HIV-specific pool of memory CD4(+) T cells increases to a greater extent than in memory CD4(+) T cells of other specificities. These findings show that HIV-specific CD4(+) T cells are preferentially infected by HIV in vivo. This provides a potential mechanism to explain the loss of HIV-specific CD4(+) T-cell responses, and consequently the loss of immunological control of HIV replication. Furthermore, the phenomenon of HIV specifically infecting the very cells that respond to it adds a cautionary note to the practice of structured therapy interruption. 相似文献
7.
Towards sustainability in world fisheries 总被引:70,自引:0,他引:70
Pauly D Christensen V Guénette S Pitcher TJ Sumaila UR Walters CJ Watson R Zeller D 《Nature》2002,418(6898):689-695
Fisheries have rarely been 'sustainable'. Rather, fishing has induced serial depletions, long masked by improved technology, geographic expansion and exploitation of previously spurned species lower in the food web. With global catches declining since the late 1980s, continuation of present trends will lead to supply shortfall, for which aquaculture cannot be expected to compensate, and may well exacerbate. Reducing fishing capacity to appropriate levels will require strong reductions of subsidies. Zoning the oceans into unfished marine reserves and areas with limited levels of fishing effort would allow sustainable fisheries, based on resources embedded in functional, diverse ecosystems. 相似文献
8.
9.
RNA polymerase is poised for activation across the genome 总被引:2,自引:0,他引:2
Muse GW Gilchrist DA Nechaev S Shah R Parker JS Grissom SF Zeitlinger J Adelman K 《Nature genetics》2007,39(12):1507-1511
10.
MacArthur DG Seto JT Raftery JM Quinlan KG Huttley GA Hook JW Lemckert FA Kee AJ Edwards MR Berman Y Hardeman EC Gunning PW Easteal S Yang N North KN 《Nature genetics》2007,39(10):1261-1265
More than a billion humans worldwide are predicted to be completely deficient in the fast skeletal muscle fiber protein alpha-actinin-3 owing to homozygosity for a premature stop codon polymorphism, R577X, in the ACTN3 gene. The R577X polymorphism is associated with elite athlete status and human muscle performance, suggesting that alpha-actinin-3 deficiency influences the function of fast muscle fibers. Here we show that loss of alpha-actinin-3 expression in a knockout mouse model results in a shift in muscle metabolism toward the more efficient aerobic pathway and an increase in intrinsic endurance performance. In addition, we demonstrate that the genomic region surrounding the 577X null allele shows low levels of genetic variation and recombination in individuals of European and East Asian descent, consistent with strong, recent positive selection. We propose that the 577X allele has been positively selected in some human populations owing to its effect on skeletal muscle metabolism. 相似文献