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排序方式: 共有42条查询结果,搜索用时 156 毫秒
1.
Michael J. A. Young Arlo W. Fast Paul G. Olin 《Journal of the World Aquaculture Society》1989,20(1):7-11
Chinese catfish ( Clarias fuscus ) were successfully spawned in Hawaii using human chorionic gonadotropin (HCG) at dosage rates of two and four international units (IU) per gram body weight. Fish not injected with HCG did not produce viable eggs. Successful spawns with HCG occurred between May and October. Hatch rates of up to 80% were obtained during June, July, and August for those fish given either a 2 or 4 IU per gram body weight injection of HCG. Fish spawned in either May or October yielded significantly higher hatch rates when injected with 4 rather than 2 IU per gram body weight. Fish held at elevated temperatures (28 to 30 C) prior to the normal spawning season developed significantly larger oocyte diameters, 60 days earlier than fish held under ambient temperature conditions (21.5 to 24 C). Photoperiod manipulation at ambient temperature conditions was associated with earlier oocyte maturation, but photoperiod effects were much less important than temperature. 相似文献
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W. H. Olin 《American Journal of Potato Research》1929,6(11):324-325
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Satu Estlander Leena Nurminen Tomáš Mrkvička Mikko Olin Martti Rask Hannu Lehtonen 《Ecology of Freshwater Fish》2015,24(4):544-552
Rising temperatures and decreasing water transparency of lakes have strong wide ranging effects on fish. Fish responses to various changes in the environment are usually species‐dependent, but responses may also vary within species. In general, large individuals are considered to be more sensitive to environmental variation due to higher energy demand, than smaller individuals. Similarly, large individuals require more food to maintain bodily functions and are thus more sensitive to resource and food scarcity. These size‐specific responses to environmental gradients are also sex‐dependent in species that exhibit sexual size dimorphism (SSD). We studied in enclosures with short‐term experiments how rising temperatures and decreasing water transparency regulate the feeding rates of female and male European perch (Perca fluviatilis L.). To explore experimental results, we calculated perch SSD in nine lakes with varying environmental conditions using previously collected field data. The results of the experiments revealed that the combined effect of water transparency and temperature on the feeding rate of fish is gender‐dependent: feeding rate of females decreased more than that of males. The experimental results were also supported by field data that revealed a negative relation between water transparency and the magnitude of SSD in perch. Our results suggest that rising temperatures and decreasing water transparency may potentially decrease fish size in a sex‐dependent manner. As female size is one of the main demographic traits determining the reproductive success of a fish population, changing environments may have unexpected and far‐reaching consequences on fish population dynamics. 相似文献
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Rodney L. Robichaud Jeffrey C. Glaubitz Olin E. Rhodes Jr. Keith Woeste 《New Forests》2006,32(2):179-196
We describe the development of a robust and powerful suite of 12 microsatellite marker loci for use in genetic investigations
of black walnut and related species. These 12 loci were chosen from a set of 17 candidate loci used to genotype 222 trees
sampled from a 38-year-old black walnut progeny test. The 222 genotypes represent a sampling from the broad geographic distribution
of the species. Analysis of the samples using the 12 loci revealed an average expected heterozygosity of 0.83, a combined
probability of identity of 3×10−19, and a combined probability of exclusion for paternity analysis of >0.999. The 222 genotyped trees from the progeny test
comprised 39 open-pollinated families, 29 of which (having at least five sampled progeny) were used to estimate the outcrossing
rate for the progeny trial. The same 29 families were used to construct a Neighbor-Joining dendrogram based upon allele sharing
between individuals. The multilocus estimate of the outcrossing rate was 100% (standard error of zero), higher than the 90%
level found in previous studies at the embryo stage, suggesting that both artificial and natural selection against selfs may
have occurred over the 38-year lifespan of the progeny trial. In the Neighbor-Joining dendrogram, the majority of the putative
siblings grouped together in 21 out of the 29 families, showing that the microsatellites were able to discern most of the
family structure in the dataset. Our results indicate that errors were sometimes committed during the establishment of the
progeny test. This set of microsatellite loci clearly provides a powerful tool for future applications in black walnut. 相似文献
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D D Olin W A Rogers A D MacMillan 《Journal of the American Veterinary Medical Association》1976,168(9):861-864
Two dogs with cloudy aqueous humor due to accumulation of lipid and lipoprotein had concurrent hyperlipemia and anterior uveitis. In 1 dog, serum and aqueous humor had similar lipoprotein electrophoretic patterns, and in the other dog, the patterns were different. The therapeutic approach included symptomatic treatment of the uveitis and reduction of dietary fat intake. Clearing of fat from aqueous humor followed control of the uveitis. 相似文献
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R.Gayman Helman DVM PhD DipACVP Olin K. Balch DVM MS PhD Connie Budd BS 《Journal of Equine Veterinary Science》2002,22(1)
The shape of equine hooves is difficult to measure and quantify. Scientific research on the effects of hoof conformation on normal and abnormal locomotion often requires precise characterization of hoof conformation. This technique produces accurate, life-size, permanent models of the hoof quickly and inexpensively from dental plastic powder and dental plaster. 相似文献
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