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11.
Sarah J. Converse Kevin J. Shelley Steve Morey Jeffrey Chan Andrea LaTier Carolyn Scafidi Deborah T. Crouse Michael C. Runge 《Biological conservation》2011,(1):319-329
The resources available to support conservation work, whether time or money, are limited. Decision makers need methods to help them identify the optimal allocation of limited resources to meet conservation goals, and decision analysis is uniquely suited to assist with the development of such methods. In recent years, a number of case studies have been described that examine optimal conservation decisions under fiscal constraints; here we develop methods to look at other types of constraints, including limited staff and regulatory deadlines. In the US, Section Seven consultation, an important component of protection under the federal Endangered Species Act, requires that federal agencies overseeing projects consult with federal biologists to avoid jeopardizing species. A benefit of consultation is negotiation of project modifications that lessen impacts on species, so staff time allocated to consultation supports conservation. However, some offices have experienced declining staff, potentially reducing the efficacy of consultation. This is true of the US Fish and Wildlife Service’s Washington Fish and Wildlife Office (WFWO) and its consultation work on federally-threatened bull trout (Salvelinus confluentus). To improve effectiveness, WFWO managers needed a tool to help allocate this work to maximize conservation benefits. We used a decision-analytic approach to score projects based on the value of staff time investment, and then identified an optimal decision rule for how scored projects would be allocated across bins, where projects in different bins received different time investments. We found that, given current staff, the optimal decision rule placed 80% of informal consultations (those where expected effects are beneficial, insignificant, or discountable) in a short bin where they would be completed without negotiating changes. The remaining 20% would be placed in a long bin, warranting an investment of seven days, including time for negotiation. For formal consultations (those where expected effects are significant), 82% of projects would be placed in a long bin, with an average time investment of 15 days. The WFWO is using this decision-support tool to help allocate staff time. Because workload allocation decisions are iterative, we describe a monitoring plan designed to increase the tool’s efficacy over time. This work has general application beyond Section Seven consultation, in that it provides a framework for efficient investment of staff time in conservation when such time is limited and when regulatory deadlines prevent an unconstrained approach. 相似文献
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对麦茬稻进行了品种、密度、育秧、施肥、喷剂试验。结果表明,壮身稀植与高穗重品种、N素V字施肥是统一的。提出高产理想株型、稀植程度和产量结构,肯定了湿润育秧方式,证实了N、P、K、Zn配合、施Si、喷胆碱复合物和水稻微肥的增产作用。 相似文献
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Jonathan C. P. Reum Timothy E. Essington Correigh M. Greene Casimir A. Rice Patrick Polte Kurt L. Fresh 《Fisheries Oceanography》2013,22(4):324-336
Variation in growth and body size during critical life history stages can have important implications for life history schedules and survivorship. For Pacific herring (Clupea pallasii), there is still debate as to whether juvenile body size is governed by density‐dependent or ‐independent processes and few have evaluated whether the relative importance of either process shifts over the course of early ontogeny. We used a unique data set consisting of seasonal measurements of abundance, body size, and spatial distribution within a semi‐enclosed basin of Puget Sound (Washington State, U.S.A.) to measure the relative importance of temperature and cohort abundance on body size at distinct time periods, and evaluated whether density‐dependent habitat shifts might be responsible for density‐dependent growth. Over the 9 years of sampling (2001–2010) midsummer body size was positively related to temperatures experienced during the egg/yolk sac and larval stages and unrelated to cohort abundance. However, fall body size was negatively correlated with abundance and uncorrelated with both midsummer body size and temperature, indicating a shift from density‐independent to density‐dependent control over the course of the growing season. Thus, density‐dependent effects may supplant density‐independent effects exhibited early in herring life history. Our data on spatial distributions of herring and their zooplankton prey indicate that density‐dependent reductions in growth may be explained by density‐dependent habitat shifts that lead to reduce overlap of herring with zooplankton. Evidence of density‐dependent growth in marine fish populations is often attributed to exploitative competition, but our results suggest that these patterns may partly be mediated by density‐dependent distribution expansions in to prey‐poor habitat. 相似文献
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D.J. Moura W.T. Silva I.A. Naas Y.A. Toln K.A.O. Lima M.M. Vale 《Computers and Electronics in Agriculture》2008,64(1):11
The analysis of animal vocalization allows the interpretation of stress pattern in a non-invasive way, and it may be used to assess welfare as well as health status and social adaptation. This paper presents the development of software to monitor and analyze distinct sounds emitted by piglets correlating the noise response with levels of stress for assessing welfare. The software was developed using Delphi5. Through the component UwaveIn the sound was recorded with an electronic microphone and set to a PC hardware that registered the signal of amplitude noise intensity, expressed in decibel (dB), converting them into bytes. Fourier Transform was used to describe the sound spectrum and transform it into frequency and intensity. Validation of the software was done in a commercial swine farm using piglets from sows’ nursery. Five examples of vocalization were studied related to distinct levels of stress (fear and alertness) due to regular management procedures. The real time monitoring allowed the detection of piglet stress exposure through the surface point polynomial adjustment. The acoustic signal recorded in the software could be partitioned allowing an evaluation of the sonograph through time. 相似文献
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车用汽油机噪声源的声强测量识别 总被引:8,自引:2,他引:6
运用声强测试技术的双传声器法原理,对一台车用汽油发动机在半消声室内进行了声强测量。根据声强测量的结果绘制声强云图和各个测量面上的主要频率成分的噪声声强云图。分析这些声强云图的特征和发动机部件在空间上的对应关系,对发动机的主要噪声源进行了识别研究。 相似文献
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A. J. Ribbink 《African Zoology》2013,48(1):45-73
Some anatomical, adult shell and larval features of Unto coffer Krauss are described and compared to those reported in previous accounts of this and other species. The findings necessitate the removal of U. caffer from the nominal genus Cafferia Simpson, for which it is the type species, and its return to the genus Unio Pbilipsson, in the Unionidae: Unioninae. Cafferia consequently becomes a junior subjective synonym of Unto.Unio caffer is characterized in part by zigzag beak sculpture, dimorphic septal spacing between the marsupial, outer (comparatively dense) and the non-marsupial, inner (more distant) demibranchs and also within the marsupial demibranchs, the presence of perforated marsupial septa and imperforate non-marsupial septa, the occurrence of hermaphrodites in some but apparently not all populations, production of subtriangular glochidia with a hook at the ventral margin of each valve, short-term incubation of larvae in the marsupial demibranchs, and by its disjunct occurrence in the southern Ethiopian region (other Unio occurring only in the Palearctic).These adult shell and anatomical features relate this species to those of several nominal genera in the Oriental region, although the latter are distinguished from it by the production of subovate, hookless glochidia. 相似文献
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介绍声强测量原理及微机分析系统,并将其应用于内燃机主要噪声源的识别,为内燃机降噪提供了可靠的科学依据。 相似文献