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Full-Text Articles in Life Sciences
Testosterone Effects On Renal Norepinephrine Content And Release In Rats With Different Y Chromosomes, Thomas J. Jones, Gail Dunphy, Amy Milsted, Daniel Ely
Testosterone Effects On Renal Norepinephrine Content And Release In Rats With Different Y Chromosomes, Thomas J. Jones, Gail Dunphy, Amy Milsted, Daniel Ely
Biology Faculty Research
The Y chromosome in spontaneously hypertensive rats (SHR) and stroke-prone rats has been shown to contain a locus that contributes to the hypertensive effect; both the sympathetic nervous system and testosterone may be involved. The objective of this study was to look at the effects of testosterone on renal norepinephrine (NE) release and content in the isolated perfused kidney in different Y chromosome backgrounds. The study involved male SHR, Wistar-Kyoto rats (WKY), and 2 consomic strains with different Y chromosomes (n=5 to 8 per group). Adult animals were castrated, and implants containing testosterone propionate were placed at the base of …
Responses Of Mole Salamanders To Clearcutting: Using Field Experiments In Forest Management, Anne C. Chazal, Peter H. Niewiarowski
Responses Of Mole Salamanders To Clearcutting: Using Field Experiments In Forest Management, Anne C. Chazal, Peter H. Niewiarowski
Biology Faculty Research
Impacts of forest management practices on amphibian populations have received growing attention in the last 10 yr. However, to date, measured responses include only comparisons of species diversity indices and population counts without true spatial and temporal controls. We used an experimental approach to test for differences in growth rate, fecundity, age at maturity, and whole-body storage lipids in individual mole salamanders, Ambystoma talpoideum, placed in differently managed habitats. Four 100-m(2) field enclosures were built in each of two habitats, a 4-mo-old clearcut and an adjacent 40-yr-old pine forest. On 19 July 1994, 80 recently metamorphosed and individually marked, weighed, …
Pollinator Selection, Quantitative Genetics, And Predicted Evolutionary Responses Of Floral Traits In Penstemon Centranthifolius (Scrophulariaceae), Randall J. Mitchell, Ruth G. Shaw, Nickolas M. Waser
Pollinator Selection, Quantitative Genetics, And Predicted Evolutionary Responses Of Floral Traits In Penstemon Centranthifolius (Scrophulariaceae), Randall J. Mitchell, Ruth G. Shaw, Nickolas M. Waser
Biology Faculty Research
Much of the remarkable diversity of angiosperm flowers is thought to have evolved in response to selection by animal pollinators. Selection during pollination can readily be documented, but the extent to which it leads to evolutionary change depends on the genetic basis of floral traits. Here we combine estimates of genetic variance and covariance for several traits of flowers and inflorescences in a wild plant species, with estimates of natural selection by hummingbird pollinators. Analysis of phenotypic selection through two components of pollination success indicates direct selection of plants toward larger size and toward bearing shorter flowers that produce more …