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Antechinus are small, insectivorous, heterothermic marsupial mammals that use torpor from late summer to early winter and reproduce once a year in late winter/early spring. Males die after mating, most females produce only a single litter, but some survive a second winter and produce another litter. As it is not known how these females manage to survive the second winter after the energetically demanding reproductive period and then reproduce a second time, we aimed to provide the first data on thermal biology of free-ranging antechinus by using temperature telemetry. Male Antechinus stuartii and Antechinus flavipes rarely entered torpor in autumn/early winter in the wild, expressing only shallow bouts of <2 h. Female A. stuartii used torpor extensively, employing bouts up to 16.7 h with body temperatures as low as 17.8 °C. Interestingly, although first and second year females used similar torpor patterns, torpor occurrence was almost twofold in second year (93 % of days) than first year females (49 %), and the proportion of the overall monitoring period animals spent torpid was 3.2-fold longer in the former with a corresponding shorter activity period. Our study suggests that intensive use of torpor is crucial for second year females for autumn and winter survival and production of a second litter. We provide the first evidence of an age-related pattern in daily torpor expression in free-ranging mammals and show that torpor use is a complex process that is affected not only by the current energy availability and thermal conditions but also by the reproductive history and age of individuals. 相似文献
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在役压力容器的动态检测技术与研究进展 总被引:3,自引:0,他引:3
根据笔者多年声发射检测与评价技术的研究成果并综合分析不同发展阶段的有关文献,论述了压力容器结构完整性检测与综合评估的意义,分析其合理性和难度,并对这种动态检测技术在评价压力容器结构完整性方面的研究进展作了较全面的评述 相似文献
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Chencho Norbu Prof. Timothy J. Downs Edward Yeboah Dr. L.J.R. Scholtens Dr. Jyotsna Bapat Maren Oelbermann Ph.D. Sayyed Ahang Kowsar Jaime Alexandra Webbe Bram Govaerts Ph.D. Nele Verhulst M. Sc. Goodspeed Kopolo Maria Rosário Partidário Mr. N’guessan Alphonse Kouassi John All Ph.D. JD Narcisa Pricope Leslie Lipper 《Natural resources forum》2008,32(3):252-256
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Dr Diana G. Day 《The Environmentalist》1993,13(3):211-220
Summary The development products of environmental research lag behind in Australia. The conventional technology transfer model may not apply where environmental research, especially in the social sciences, is still seen as marginal to society. Pragmatic planning is needed for strategic security in times of trouble ahead. Cultural alignment with technological advance allows seduction by laboratories, white gladiatorial coats and expensive equipment imparting high credibility. A correctness for research futures disallows more radical pathways by the use of profit watchers, waste watch committees, technocrats and masculinist political views.A new protocol for environmental research and development calls for less complacency, scrutiny of political and military investment in nuclear futures, greater public policy analysis of issues such as pesticides in Australia's cotton industry, more attention to natural systems thresholds, radical review of social mores, more flexible management systems and closer links between strategic land use and environmental planning.She currently works for the New South Wales Department of Water Resources as a Senior Executive Officer. She has published widely on environmental policy analysis and water planning, and is a Director of Australia's National Land and Water Resources Research and Development Corporation. 相似文献
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Professor A. H. Walters Dr M. Ghannoum Dr M.Abu Lisan Dr K. E. Moore 《The Environmentalist》1981,1(2):133-143
Summary The environmental education needs of a currently wealthy developing country, Libya, are outlined. Because of specific local requirements, the data presented clearly shows how such educational requirements differ in many respects from the various Western-style environmental sciences curricula. The aim is to produce graduates capable of comprehending environmental problems as they arise in the different regions of Libya. This involves not only dealing with the effects of new developments but also with peoples who must adapt to new life-styles.Since most of what has to be learned is communicated originally in English to Arabic-speaking students via lectures, visits and books, special emphasis is laid upon the added importance oflocally produced bilingual audio-visual teaching aids supported by spoken commentaries, printed texts and glossaries of technical terms used in both languages. A technique for producing such aids has been evolved at the Higher Institute of Technology, Brack, Libya. 相似文献