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排序方式: 共有50条查询结果,搜索用时 15 毫秒
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VICKY J. MERETSKY VIRGIL BRACK JR. TIMOTHY C. CARTER RICHARD CLAWSON ROBERT R. CURRIE TRACI A. HEMBERGER CARL J. HERZOG ALAN C. HICKS JOSEPH A. KATH JOHN R. MACGREGOR R. ANDREW KING DAVID H. GOOD 《The Journal of wildlife management》2010,74(1):166-173
ABSTRACT The size and distribution of measurement errors associated with major techniques for estimating numbers of hibernating bats are unstudied, although this is the principle method of enumerating several endangered bat species. However, decisions concerning the listing status of a species under the Endangered Species Act require consistent and accurate estimation of population size and trends. Recent advances in digital photography have improved the ability to produce a quantitative record of the numbers of bats in hibernacula. We surveyed clusters of Indiana bats in a hibernaculum and compared results from counts of digital photographs of clusters to results from 4 variations of visual estimation. We counted bats in photographs using Geographic Information System digitization over the photograph. Total counts from 2 sets of photographs varied by <1.5%. Nonphotographic estimation techniques varied from 76% to 142% of counts from photographs for clusters for which estimation (rather than counting) was used. Where feasible, photography can improve status and trend information for species of concern, permitting more timely and specific management actions. 相似文献
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THE GEOGRAPHICAL AFFINITIES OF THE FLORA OF JEBEL MARRA 总被引:1,自引:0,他引:1
RONALD GOOD 《The New phytologist》1924,23(5):266-281
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THE EFFECT OF ESTROGEN ON ODOR DETECTION 总被引:1,自引:1,他引:0
Olfactory sensitivity to Exaltolide was assessed with a signaldetection procedure. In four women tested through five completemenstrual cycles, significant shifts in sensitivity were notedin three cycles for which rectal temperature changes indicatedovulation, but in only one of two anovulatory cycles. In addition,one pregnant woman showed improvement as the number of weeksprior to parturition decreased and one hypogonadal and apparentlyanosmic woman became increasingly sensitive to the Exaltolideodor while undergoing estrogen therapy. These results confirmand extend previous reports that olfactory sensitivity variesaccording to hormonal status.
*We gratefully acknowledge the valuable assistance of Dr. JohnEvrard of the Brown University Medical School.
** Requests for reprints should be addressed to Trygg Engen,Department of Psychology, Brown University, Providence, R.I.02912. 相似文献
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JUHANI LINNA T.; FINSTAD JOANNE; GOOD ROBERT A. 《Integrative and comparative biology》1975,15(1):29-38
The cyclostomes, hagfishes and lamprey, represent modern agnathans,the most primitive vertebrates. They are therefore of specialinterest from the phylogenetic view point with regard to proliferativeactivities of epithelial and of lympho-hematopoietic tissues.The animals, kept in aquaria at 15 C, were given 1.0 µCiof 3H-thymidine per gram of body weight intramuscularly, killed2 hr later, different organs prepared for autoradiograms usingthe liquid emulsion technique, and the labeling indices determined.In peripheral blood, cell proliferation occurred mainly in thehemocytoblast group of cells in both species. Both lympho-hematopoieticcells and epithelial cells proliferated in the lamprey, althoughat a relatively low rate, perhaps attributable to senescence.In the hagfish, blood-forming and epithelial cells were rapidlyproliferating, with the dramatic exception of intestinal epithelium,where the proliferative activity was extremely low. This Findingmay well explain the documented high resistance of hagfishesto irradiation and alkylating agents, in contrast to the lamprey,which is approximately as sensitive to these agents as mostadvanced vertebrates. 相似文献
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RHETT E. GOOD RYAN M. NIELSON HALL SAWYER LYMAN L. MCDONALD 《The Journal of wildlife management》2007,71(2):395-402
ABSTRACT Researchers have suggested golden eagle (Aquila chrysaetos) populations may be declining in portions of their range. However, there are few baseline data describing golden eagle populations across their range in the western United States. We used aerial line transect distance methodology with a double-observer modification to estimate golden eagle population numbers in 4 bird conservation regions of the western United States. We conducted surveys from 16 August to 8 September 2003, after most golden eagles had fledged and before fall migration. The goal of our sampling strategy was to provide >80% power (α = 0.1) to detect an annual rate of total population change >3% per year over a 20-year period. We observed 172 golden eagles across 148 transects and estimated 27,392 golden eagles (90% CI: 21,352-35,140) occurred in the study area during the late summer and early fall of 2003. Following the surveys, we used Monte Carlo simulation to determine the statistical power to detect trends in the golden eagle populations if yearly surveys were continued over a 20-year monitoring period. The simulation indicated the desired power could be achieved under the current methodology and sample size. The methods utilized in this study can be implemented for other raptor species when population estimates that include nonbreeding members of a population are needed. The results of this study can be utilized by professionals to help manage golden eagle populations and to develop conservation strategies. 相似文献
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