Science in the persian gulf     

Boyce TM 《Science (New York, N.Y.)》1991,252(5007):763

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Laboratory simulation of charge exchange-produced X-ray emission from comets     

Beiersdorfer P  Boyce KR  Brown GV  Chen H  Kahn SM  Kelley RL  May M  Olson RE  Porter FS  Stahle CK  Tillotson WA 《Science (New York, N.Y.)》2003,300(5625):1558-1559

In laboratory experiments using the engineering spare microcalorimeter detector from the ASTRO-E satellite mission, we recorded the x-ray emission of highly charged ions of carbon, nitrogen, and oxygen, which simulates charge exchange reactions between heavy ions in the solar wind and neutral gases in cometary comae. The spectra are complex and do not readily match predictions. We developed a charge exchange emission model that successfully reproduces the soft x-ray spectrum of comet Linear C/1999 S4, observed with the Chandra X-ray Observatory.  相似文献   

Dynamic wildlife habitat models: Seasonal foods and mortality risk predict occupancy-abundance and habitat selection in grizzly bears   总被引：1，自引：0，他引：1  

Scott E. Nielsen  Greg McDermid  Mark S. Boyce 《Biological conservation》2010,143(7):1623-1634

Most current wildlife habitat models, such as resource selection functions, typically assume a static environment, extrapolate poorly in space and time, and often lack linkages to population processes. We submit that more mechanistic habitat models that directly consider bottom-up resources affecting growth and reproduction (i.e., food) and top-down limitations affecting survival are needed to effectively predict habitat quality, especially in the presence of rapid environmental change. Here we present a general model for estimating potential habitat quality (relating to growth and reproduction) and realised habitat quality (accounting for survival) using basic knowledge of the species’ seasonal diet, predicted locations of food resource patches and regional patterns in mortality risk. We illustrate our model for a threatened population of grizzly bears in west-central Alberta. Bi-monthly potential habitat quality successfully predicted habitat selection by radio-collared grizzly bears, while multi-seasonal realised habitat quality predicted patterns in occupancy-abundance as measured from unique bears at hair-snag sites. Bottom-up resources therefore predicted patterns of habitat selection, while top-down processes (survival) were necessary to scale-up to population measures. We suggest that more direct measures of resources and environments that affect growth, reproduction and survival, as well as match the temporal scale of animal behaviour, be considered when developing wildlife habitat models.  相似文献   

Termiticidal lectins from Myracrodruon urundeuva (Anacardiaceae) cause midgut damage when ingested by Nasutitermes corniger (Isoptera: Termitidae) workers          下载免费PDF全文

Thâmarah A Lima  Kenner M Fernandes  Ana Patrícia S Oliveira  Leonardo P Dornelles  Gustavo F Martins  Thiago H Napoleão  Patrícia MG Paiva 《Pest management science》2017,73(5):991-998

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