145 research outputs found
Exogenous kisspeptin enhances seasonal reproductive function in male Siberian hamsters
No full textContains all raw data used in the Functional Ecology article "Exogenous kisspeptin enhances seasonal reproductive function in male Siberian hamsters (Phodopus sungorus)" by Allison Bailey, Sandra Legan, and Gregory Demas, including hamster body mass, food intake, estimated testis volume, final reproductive mass, and serum hormone concentrations
Supplementary Electronic Appendix, accompanying article: Physiological Predictors of Leptin Vary Across the Menstrual Cycle in Healthy Women, by K.E. Sylvia, T.K. Lorenz, J.R. Heiman, & G. E. Demas; under consideration at The American Journal of Human Biology.
No full textThis work was partially funded by the Office of the Vice Provost of Research at Indiana University-Bloomington through the Collaborative Research and Creative Activity Funding Award, and partially by the American Psychological Foundation’s Henry P. David Award for Research in Human Reproductive Behavior and Population Studies. Dr. Lorenz was supported by grant T32HD049336 from the National Institute of Child Health and Human Development.The data presented here were collected as part of a larger study of the effects of sexual behavior on healthy women’s immune and endocrine function across the menstrual cycle. See (Lorenz, Demas, et al. 2015; Lorenz, Heiman, et al. 2015) for full details of the parent study. All study procedures were approved by the Indiana University Institutional Review Board, and all participants provided informed consent
Energetic signals and stressors regulate reproductive-immune trade-offs and seasonal sickness responses in Siberian hamsters
No full textThesis (Ph.D.) - Indiana University, Biology, 2015To ensure survival and reproductive success, animals must optimally allocate energy among various physiological and behavioral processes while inhabiting environments that change predictably across and unpredictably within seasons. In this dissertation, I examined the mechanisms by which a seasonally-breeding rodent allocates energy between the reproductive and immune systems within the breeding season and modulates intensity of its sickness responses to a simulated infection across seasons. Siberian hamsters (Phodopus sungorus) inhibit reproduction and display lower body masses, lower levels of the adipose hormone leptin, and less intense sickness responses when housed in short, winter-like days compared to long, summer-like days. I used several techniques to modulate the internal energetic state of the hamsters (i.e., food restriction, manipulation of the energetic hormones leptin and insulin, pharmacological induction of glucose deprivation) to determine its role in reproductive-immune trade-offs and seasonal regulation of sickness intensity. In the first chapter, I examined energetic mechanisms involved in regulating reproductive-immune trade-offs in reproductively-active female hamsters. I found that glucose deprivation resulted in reproductive suppression, however, suppression could be alleviated when animals were provided with a hormonal signal of increased fat stores (i.e., leptin). Alternatively, reproduction was not inhibited when animals experienced more severe glucose deprivation; yet, providing animals with the signal of increased fat stores during this period of severe glucose deprivation resulted in decreased allocation to humoral immunity. In the last three chapters, I examined the contributions of seasonal changes in energetic fuels and signals to seasonal variation in sickness intensity. I found that seasonal variation in sickness-induced hypothermia was regulated by seasonal changes in glucose availability and leptin levels; however, seasonal changes in sickness-induced anorexia and body mass loss were regulated by seasonal differences in body mass more generally. Finally, I observed that changes in insulin, a pancreatic hormone secreted in response to positive energy balance, had both suppressive and enhancing effects on sickness intensity depending on energetic context. These collective findings illustrate that physiological trade-offs and sickness intensity are sensitive to a variety of energetic modulators and that the effects of these modulators are dependent on their interactions with each other and the environment
Supplementary Electronic Appendix, accompanying article: Physiological Predictors of Leptin Vary During Menses and Ovulation in Healthy Women, by K.E. Sylvia, T.K. Lorenz, J.R. Heiman & G.E. Demas; under consideration.
No full textThis work was partially funded by the Office of the Vice Provost of Research at Indiana University-Bloomington through the Collaborative Research and Creative Activity Funding Award, and partially by the American Psychological Foundation’s Henry P. David Award for Research in Human Reproductive Behavior and Population Studies. Dr. Lorenz was supported by grant T32HD049336 from the National Institute of Child Health and Human Development
Supplementary Electronic Appendix, accompanying article: Physiological Predictors of Leptin Vary During Menses and Ovulation in Healthy Women, by K.E. Sylvia, T.K. Lorenz, J.R. Heiman & G.E. Demas; under consideration.
No full textThis work was partially funded by the Office of the Vice Provost of Research at Indiana University-Bloomington through the Collaborative Research and Creative Activity Funding Award, and partially by the American Psychological Foundation’s Henry P. David Award for Research in Human Reproductive Behavior and Population Studies. Dr. Lorenz was supported by grant T32HD049336 from the National Institute of Child Health and Human Development
In vivo but not in vitro leptin enhances lymphocyte proliferation in Siberian hamsters (Phodopus sungorus)
No full text
Our Masters
No full textThis chapter discusses black professional players and the little-known history of the United Golfers Association (UGA), a black golf organization that was founded in 1925 and served as a parallel institution to the all-white Professional Golfers’ Association (PGA) that formed nine years earlier in 1916. Along with many other activities, the UGA operated a national golf tour for professionals, amateurs, and intercollegiate golfers, and it continued to host events well after the desegregation of the PGA in 1961. Similar to the story of baseball’s Negro Leagues and their central place in American culture, the UGA also featured African Americans who used professional sport to carve out autonomous sites for leisure, business, and fandom. As the only national professional golf tour for black players in American history, virtually every black pro before Tiger Woods experienced playing in UGA events, a long list that includes John Shippen, Robert “Pat” Ball, John Brooks Dendy, Howard Wheeler, Charlie Sifford, Bill Spiller, Ted Rhodes, and Lee Elder. The UGA also supported a full women’s division, which over time featured gifted stars like Marie Thompson, Lucy Williams, Geneva Wilson, Ann Gregory, Thelma Cowans, Ethel (Powers) Funches, Althea Gibson, and Renee Powell.</p
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