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Full-Text Articles in Life Sciences
Reproductive Competency And Mitochondrial Variation In Aged Syrian Hamster Oocytes, Fang Li, Frank J. Castora, Wentia Ford, Khalid Alarid, Howard W. Jones Jr., R. James Swanson
Reproductive Competency And Mitochondrial Variation In Aged Syrian Hamster Oocytes, Fang Li, Frank J. Castora, Wentia Ford, Khalid Alarid, Howard W. Jones Jr., R. James Swanson
Biological Sciences Faculty Publications
The hamster is a useful model of human reproductive biology because its oocytes are similar to those in humans in terms of size and structural stability. In the present study we evaluated fecundity rate, ovarian follicular numbers, ova production, mitochondrial number, structure and function, and cytoplasmic lamellae (CL) in young (2–4 months) and old (12–18 months) Syrian hamsters (Mesocricetus auratus). Young hamsters had higher fertilisation rates and larger litters than old hamsters (100 vs 50% and 9.3 +/- 0.6 vs 5.5 +/- 0.6, respectively). Ovarian tissue from superovulated animals showed a 46% decrease in preantral follicles in old …
Testing Alternative Hypotheses For The Cause Of Population Declines: The Case Of The Red-Headed Woodpecker, Walter D. Koenig, Eric L. Walters, Paul G. Rodewald
Testing Alternative Hypotheses For The Cause Of Population Declines: The Case Of The Red-Headed Woodpecker, Walter D. Koenig, Eric L. Walters, Paul G. Rodewald
Biological Sciences Faculty Publications
The Red-headed Woodpecker (Melanerpes erythrocephalus) has experienced strong population declines during the past 3 decades. Using North American Breeding Bird Survey (BBS) and Audubon Christmas Bird Count (CBC) data, we investigated 4 hypotheses that may explain this decline, including: (1) interspecific competition with native Red-bellied Woodpeckers (Melanerpes carolinus) and nonnative European Starlings (Sturnus vulgaris); (2) predation by Cooper's Hawks (Accipiter cooperii) and Sharp-shinned Hawks (Accipiter striatus); (3) climate change; and (4) changes in forested area within their range. In analyses of both the breeding and overwintering periods, our results indicated …