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Abstract: This article is part of a Special Issue “Energy Balance”. Natural populations display a variety of reproductive responses to environmental cues, but the underlying physiology that causes these responses is largely unknown. This study tested the hypothesis that heritable variation in reproductive traits can be described by heritable variation in concentrations of hormones critical to both energy balance and reproduction. To test this hypothesis, we used mouse lines derived from a wild population and selectively bred for response to short day photoperiod. Reproductive and metabolic traits of Peromyscus leucopus display heritable variation when held in short photoperiods typical of winter. Our two lines of mice have phenotypes spanning the full range of variation observed in nature in winter. We tested male and female mice for heritable variation in fasted serum concentrations of three hormones involved in energetic regulation: leptin, insulin-like growth factor 1 (IGF-1) and insulin, as well as the effects of exogenous leptin and a high energy diet on reproductive maturation. Exogenous leptin decreased food intake, but protected males from the reduction in testis mass caused by equivalent food restriction in pair-fed, saline-infused controls. A high energy diet resulted in calorie adjustment by the mice, and failed to alter reproductive phenotype. Concentrations of the three hormones did not differ significantly between selection lines but had correlations with measures of food intake, fertility, blood glucose, and/or body mass. There was evidence of interactions between reproductive traits and hormones related to energy balance and reproduction, but this study did not find evidence that variation in these hormones caused variation in reproductive phenotype. [Copyright &y& Elsevier]

Objective: To develop an observational coding instrument for evaluating the fidelity and quality of brief behavioral change interventions based on the behavioral theories of the 5 A's, Stages of Change and Motivational Interviewing. Methods: Content and face validity were assessed prior to an intervention where psychometric properties were evaluated with a prospective cohort of 116 medical students. Properties assessed included the inter-rater reliability of the instrument, internal consistency of the full scale and sub-scales and descriptive statistics of the instrument. Construct validity was assessed based on student's scores. Results: Inter-rater reliability for the instrument was 0.82 (intraclass correlation). Internal consistency for the full scale was 0.70 (KR20). Internal consistencies for the sub-scales were as follows: MI intervention component (KR20=.7); stage-appropriate MI-based intervention (KR20=.55); MI spirit (KR20=.5); appropriate assessment (KR20=.45) and appropriate assisting (KR20=.56). Conclusions: The instrument demonstrated good inter-rater reliability and moderate overall internal consistency when used to assess performing brief behavioral change interventions by medical students. Practice implications: This practical instrument can be used with minimal training and demonstrates promising psychometric properties when evaluated with medical students counseling standardized patients. Further testing is required to evaluate its usefulness in clinical settings. [Copyright &y& Elsevier]

Abstract: Male reproductive behavior is highly dependent upon gonadal steroids. However, between individuals and across species, the role of gonadal steroids in male reproductive behavior is highly variable. In male B6D2F1 hybrid mice, a large proportion (about 30%) of animals demonstrate the persistence of the ejaculatory reflex long after castration. This provides a model to investigate the basis of gonadal steroid-independent male sexual behavior. Here we assessed whether non-gonadal steroids promote mating behavior in castrated mice. Castrated B6D2F1 hybrids that persisted in copulating (persistent copulators) were treated with the androgen receptor blocker, flutamide, and the aromatase enzyme inhibitor, letrozole, for 8 weeks. Other animals were treated with the estrogen receptor blocker, ICI 182,780, via continual intraventricular infusion for 2 weeks. None of these treatments eliminated persistent copulation. A motivational aspect of male sexual behavior, the preference for a receptive female over another male, was also assessed. This preference persisted after long-term castration in persistent copulators, and administration of ICI 182,780 did not influence partner preference. To assess the possibility of elevated sensitivity to sex steroids in brains of persistent copulators, we measured mRNA levels for genes that code for the estrogen receptor-α, androgen receptor, and aromatase enzyme in the medial preoptic area and bed nucleus of the stria terminalis. No differences in mRNA of these genes were noted in brains of persistent versus non-persistent copulators. Taken together our results suggest that non-gonadal androgens and estrogens do not maintain copulatory behavior in B6D2F1 mice which display copulatory behavior after castration. [Copyright &y& Elsevier]