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151.
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Trevor Lukey Kuldeep Neote John F. Loman Ardythe E. Unger Fred G. Biddle Floyd F. Snyder 《Biochemical genetics》1985,23(3-4):347-356
An improved method for detecting four Np-1 (purine nucleoside phosphorylase) alleles in mouse erythrocytes by cellulose acetate electrophoresis is described. The previous linkage of Np-1 and Es-10 (esterase-10) was confirmed, with a map distance of 13.0±2.6 cM. Np-2 was detected by either specific activity assay or starch gel electrophoresis and shown to be linked to Es-10, 15.9 ± 3.1 cM, on chromosome 14. No recombinants between Np-1 and Np-2 were observed in 52 offspring, indicating either that these loci are either closely associated or that Np-2 represents simply a property of existing allelic products of the Np-1 locus.This research was supported by Medical Research Council of Canada grants to F.G.B. and F.F.S. 相似文献
153.
Fred. J. Smith 《BMJ (Clinical research ed.)》1909,1(2515):692-693
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Knowledge of the reproductive life history of giraffe in the wild is sparse. Giraffe have two fairly unusual reproductive patterns among large mammals: they can become pregnant while lactating, and calf mortality is extremely high. Longitudinal records are largely absent, so tracking reproductive parameters tends to combine information from captive and field studies. In this study, we examine longitudinal data obtained over a 33‐year period in one population of Thornicroft’s giraffe in order to chart their reproductive careers. We found that age at first parturition was 6.4 years, or slightly later than in captivity. Giraffe bred throughout the year, with cows producing offspring on average every 677.7 days. About half of the calves died before one year of age, but death of a calf did not reduce interbirth interval. We conclude that the lifetime reproductive success of giraffe is more dependent on longevity and calf survivorship than on reproductive rate. 相似文献
157.
Fred Sherman 《Genetics》1963,48(3):375-385
158.
Burning shrub and grassland communities often leads to increases in plant production and nutritional quality that benefit
herbivores, resulting in increased herbivore use of burned areas. Increased use has been ascribed more specifically to changes
in plant community structure, community composition and diversity, nutritional quality, and seasonal availability. These hypotheses
can be evaluated more precisely if changes in plant communities following burning are monitored concurrently with changes
in herbivore use, especially in longer-term studies. From 1988 to 1999, we examined responses of elk (Cervus elaphus) following prescribed burning of areas burned in 1984 and 1988 that had been formerly dominated by mountain big sagebrush
(Artemisia tridentata ssp. vaseyana) in south-central Montana (USA), with concurrent monitoring of changes in plant production, nutritional quality, and community
composition. Elk made increased use of burned sites up to 15 years after burning. Burning transformed big sagebrush-dominated
communities into native herbaceous communities that persisted for 15 years without sagebrush reinvasion. Forage biomass and
protein content remained higher on burned sites for 15 years, although differences were not significant in every year and
declined as time elapsed after burning. Forage production, forage protein, and elk use were temporally correlated, suggesting
the possibility that grazing by elk might have contributed to persistence of elevated plant production and protein levels
on burned sites. 相似文献
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Shai Meiri Luciano Avila Aaron M. Bauer David G. Chapple Indraneil Das Tiffany M. Doan Paul Doughty Ryan Ellis Lee Grismer Fred Kraus Mariana Morando Paul Oliver Daniel Pincheira‐Donoso Marco Antonio Ribeiro‐Junior Glenn Shea Omar Torres‐Carvajal Alex Slavenko Uri Roll 《Global Ecology and Biogeography》2020,29(9):1515-1530