Understanding physiological and behavioral mechanisms underlying the diversity of observed life-history strategies is challenging because of difficulties in obtaining long-term measures of fitness and in relating fitness to these mechanisms. We evaluated effects of experimentally elevated testosterone on male fitness in a population of dark-eyed juncos studied over nine breeding seasons using a demographic modeling approach. Elevated levels of testosterone decreased survival rates but increased success of producing extra-pair offspring. Higher overall fitness for testosterone-treated males was unexpected and led us to consider indirect effects of testosterone on offspring and females. Nest success was similar for testosterone-treated and control males, but testosterone-treated males produced smaller offspring, and smaller offspring had lower postfledging survival. Older, more experienced females preferred to mate with older males and realized higher reproductive success when they did so. Treatment of young males increased their ability to attract older females yet resulted in poor reproductive performance. The higher fitness of testosterone-treated males in the absence of a comparable natural phenotype suggests that the natural phenotype may be constrained. If this phenotype were to arise, the negative social effects on offspring and mates suggest that these effects might prevent high-testosterone phenotypes from spreading in the population.

We use a nonlinear finite element (FE) method model to compare, optimize and determine the limits for useful geometries of microfluidic valves in elastomer polydimethylsiloxane (PDMS). Simulations have been performed with the aim of finding the optimal shape, size and location of pressurization that minimizes the pressure required to operate the valve. One important constraint governing the design parameters is that the stresses should be within elastic limits, so that the component remains safe from any type of structural failure. To obtain reliable results, non-linear stress analysis was performed using the Mooney-Rivlin 9 parameter approximation which is based on the Hyper Elastic Material Model. A 20 noded brick element was used for the development of FE model. Mesh sensitivity analysis was also performed to assess the quality of the results. The simulations were performed with commercially available FE modeling software, developed by ANSYS Inc. to determine the effect of varying different geometric parameters on the performance of micro-fluidic valves.The aim of this work is to determine the geometry of the channel crosssection that would result in the largest deflection for the least applied pressure, i.e. to minimize the pressure needed to operate the valve.

Results showed that treatment of sweet potato starch with different doses of gamma irradiation caused increase in starch acidity and reducing sugars as well as molecular degradation, occurred as a result of the marked decrease in viscosity and intrinsic viscosity and water absorption while the solubility increased.