Brief increases in corticosterone affect morphology, stress responses, and telomere length, but not post-fledging movements, in a wild songbird

Organisms are frequently exposed to challenges during development, such as poor weather and food shortage. Such challenges can initiate the hormonal stress response, which involves secretion of glucocorticoids. Although the hormonal stress response helps organisms deal with challenges, long-term exposure to high levels of glucocorticoids can have morphological, behavioral, and physiological consequences, especially during development. Glucocorticoids are also associated with reduced survival and telomere shortening. To investigate whether brief, acute exposures to glucocorticoids can also produce these phenotypic effects in free-living birds, we exposed wild tree swallow (Tachycineta bicolor) nestlings to a brief exogenous dose of cort once per day for five days and then measured their morphology, baseline and stress-induced corticosterone levels, and telomere length. We also deployed radio tags on a subset of nestlings, which allowed us to determine the age at which tagged nestlings left the nest (fledged) and their pattern of presence and absence at the natal site during the post-breeding period. Corticosterone-treated nestlings had lower mass, higher baseline and stress-induced corticosterone, and reduced telomeres; other metrics of morphology were affected weakly or not at all. Our treatment resulted in no significant effect on survival to fledging, fledge age, or age at first departure from the natal site, and we found no negative effect of corticosterone on inter-annual return rate. These results show that brief acute corticosterone exposure during development can have measurable effects on phenotype in free-living tree swallows. Corticosterone may therefore mediate correlations between rearing environment and phenotype in developing organisms, even in the absence of prolonged stressors.Comment: 35 pages, 4 figures, 1 appendi

Effect of Ibuprofen Administration on Postural Changes in Post-Parturient Sows

Loss of piglets due to crushing is an unnecessary loss that creates both a financial and welfare concern for the swine industry. Sows in the wild lie more quietly after farrowing compared with sows in farrowing crates. The restless behavior of the sow in a farrowing crate increases the chances that she will crush her offspring. Data collected during this study indicate that the discomfort a sow feels associated with lying on a hard surface after farrowing can not be relieved with ibuprofen. This discomfort causes her to change positions more frequently, increasing the chances that she will crush her piglets. Emphasis needs to focus on allowing the post-parturient sow to rest quietly if a decrease in piglet crushing is to be realized

Liquid 4He near the superfluid transition in the presence of a heat current and gravity

The effects of a heat current and gravity in liquid 4He near the superfluid transition are investigated for temperatures above and below T_lambda. We present a renormalization-group calculation based on model F for the Green's function in a self-consistent approximation which in quantum many-particle theory is known as the Hartree approximation. The approach can handle a zero average order parameter above and below T_lambda and includes effects of vortices. We calculate the thermal conductivity and the specific heat for all temperatures T and heat currents Q in the critical regime. Furthermore, we calculate the temperature profile. Below T_lambda we find a second correlation length which describes the dephasing of the order parameter field due to vortices. We find dissipation and mutual friction of the superfluid-normal fluid counterflow and calculate the Gorter-Mellink coefficient A. We compare our theoretical results with recent experiments.Comment: 26 pages, 9 figure

Applied Geometry Optimization of an Innovative 3D-Printed Wet-Scrubber Nozzle with a Lattice Boltzmann Method

In contrast to conventional dry separators, new types of wet scrubbers with innovative nozzle geometries are capable of separating submicron particles with comparatively low pressure drop. As those geometries can easily be adapted using 3D-printing manufacturing, an applied geometry optimization can lead to a fast and cost-efficient product development cycle. In this study, the lattice Boltzmann method is used to optimize the pressure drop associated with a novel nozzle design. Simulated pressure drop data are validated with experimentally determined ones. By replacing originally installed ellipsoid-shaped bluff bodies with foil-shaped structures according to the 4-digit NACA-series, an optimization approach regarding the resulting pressure drop is described

Criticality and Superfluidity in liquid He-4 under Nonequilibrium Conditions

We review a striking array of recent experiments, and their theoretical interpretations, on the superfluid transition in $^4$He in the presence of a heat flux, $Q$. We define and evaluate a new set of critical point exponents. The statics and dynamics of the superfluid-normal interface are discussed, with special attention to the role of gravity. If $Q$ is in the same direction as gravity, a self-organized state can arise, in which the entire sample has a uniform reduced temperature, on either the normal or superfluid side of the transition. Finally, we review recent theory and experiment regarding the heat capacity at constant $Q$. The excitement that surrounds this field arises from the fact that advanced thermometry and the future availability of a microgravity experimental platform aboard the International Space Station will soon open to experimental exploration decades of reduced temperature that were previously inaccessible.Comment: 16 pages, 9 figures, plus harvard.sty style file for references Accepted for publication in Colloquia section of Reviews of Modern Physic

Swine Housing Impacts on Environment and Behavior: A comparison between hoop structures and total environmental control

The effect of housing on animal environment and behavior have been studied in a comparative trial with three deep-bedded hoop structures and one totally, environmentally- controlled slatted-floor building. In order to assess animal welfare, behavior indicative of both poor and rich welfare were quantified. Behavior indicative of poor welfare were considered to be the performance of aberrant behavior, stereotypical behavior and excessive fighting. Behaviors indicative of rich behavior were the performance of normal maintenance behaviors and play behavior. Hoop structures experienced lower winter air temperatures than did the confinement building (mean, 4.8 0 vs. 18.1 0 C), but effective temperatures for the animals were enhanced in the hoop structure by heat generated by the decomposing bedded pack (ranging from approximately –1.1 0 C to 47 0 C). The confinement building maintained a higher ammonia level than did the hoop structures. Pigs raised in the confinement system which did use bedding were found to be resting more often (P \u3c .03); however, they were also found to perform more aberrant and stereotypical behavior in addition to more frequent fighting (P \u3c .03). Pigs raised in the hoop structure were found to perform more play behavior than confinement raised pigs (P \u3c .03). Based on the greater incidence of aberrant, stereotyped, and agonistic behavior of confinement pigs and the greater incidence of play behavior by hoop raised pigs; the welfare of hoop raised pigs is considered to be richer than that of confinement raised pigs. The major contributing factor to explain this is likely the provision of bedding, which allows the pigs an opportunity to perform species typical behavior