Favorable spring conditions can buffer the impact of winter carryover effects on a key breeding decision in an Arctic-breeding seabird

The availability and investment of energy among successive life-history stages is a key feature of carryover effects. In migratory organisms, examining how both winter and spring experiences carryover to affect breeding activity is difficult due to the challenges in tracking individuals through these periods without impacting their behavior, thereby biasing results. Using common eiders Somateria mollissima, we examined whether spring conditions at an Arctic breeding colony (East Bay Island, Nunavut, Canada) can buffer the impacts of winter temperatures on body mass and breeding decisions in birds that winter at different locations (Nuuk and Disko Bay, Greenland, and Newfoundland, Canada; assessed by analyzing stable isotopes of 13-carbon in winter-grown claw samples). Specifically, we used path analysis to examine how wintering and spring environmental conditions interact to affect breeding propensity (a key reproductive decision influencing lifetime fitness in female eiders) within the contexts of the timing of colony arrival, pre-breeding body mass (body condition), and a physiological proxy for foraging effort (baseline corticosterone). We demonstrate that warmer winter temperatures predicted lower body mass at arrival to the nesting colony, whereas warmer spring temperatures predicted earlier arrival dates and higher arrival body mass. Both higher body mass and earlier arrival dates of eider hens increased the probability that birds would initiate laying (i.e., higher breeding propensity). However, variation in baseline corticosterone was not linked to either winter or spring temperatures, and it had no additional downstream effects on breeding propensity. Overall, we demonstrate that favorable pre-breeding conditions in Arctic-breeding common eiders can compensate for the impact that unfavorable wintering conditions can have on breeding investment, perhaps due to greater access to foraging areas prior to laying

Development of homeothermic endothermy is delayed in high-altitude native deer mice (Peromyscus maniculatus)

Altricial mammals begin to independently thermoregulate during the firstfew weeks of postnatal development. In wild rodent populations, this isalso a time of high mortality (50–95%), making the physiological systemsthat mature during this period potential targets for selection. High altitude(HA) is a particularly challenging environment for small endotherms owingto unremitting low O2and ambient temperatures. While superior thermo-genic capacities have been demonstrated in adults of some HA species, itis unclear if selection has occurred to survive these unique challengesearly in development. We used deer mice (Peromyscus maniculatus) nativeto high and low altitude (LA), and a strictly LA species (Peromyscus leucopus),raised under common garden conditions, to determine if postnatal onset ofendothermy and maturation of brown adipose tissue (BAT) is affected byaltitude ancestry. We found that the onset of endothermy correspondswith the maturation and activation of BAT at an equivalent age in LAnatives, with 10-day-old pups able to thermoregulate in response to acutecold in both species. However, the onset of endothermy in HA pups wassubstantially delayed (by approx. 2 days), possibly driven by delayedsympathetic regulation of BAT. We suggest that this delay may be part ofan evolved cost-saving measure to allow pups to maintain growth ratesunder the O2-limited conditions at HA

Abnormal beta power is a hallmark of explicit movement control in functional movement disorders.

OBJECTIVE: To determine whether sensorimotor beta-frequency oscillatory power is raised during motor preparation in patients with functional movement disorders (FMD) and could therefore be a marker of abnormal "body-focused" attention. METHODS: We analyzed motor performance and beta-frequency cortical oscillations during a precued choice reaction time (RT) task with varying cue validity (50% or 95% congruence between preparation and go cues). We compared 21 patients with FMD with 13 healthy controls (HCs). RESULTS: In HCs, highly predictive cues were associated with faster RT and beta desynchronization in the contralateral hemisphere (contralateral slope -0.045 [95% confidence interval (CI) -0.057 to -0.033] vs ipsilateral -0.033 [95% CI -0.046 to -0.021], p < 0.001) and with a tendency for reaching lower contralateral end-of-preparation beta power (contralateral -0.482 [95% CI -0.827 to -0.137] vs ipsilateral -0.328 [95% CI -0.673 to 0.016], p = 0.069). In contrast, patients with FMD had no improvement in RTs with highly predictive cues and showed an impairment of beta desynchronization and lateralization before movement. CONCLUSIONS: Persistent beta synchronization during motor preparation could reflect abnormal explicit control of movement in FMD. Excessive attention to movement itself rather than the goal might maintain beta synchronization and impair performance

Forming Limits of Weld Metal in Aluminum Alloys and Advanced High-Strength Steels

This work characterizes the mechanical properties of DP600 laser welded TWBs (1 mm-1.5 mm) near and in the weld, as well as their limits of formability. The approach uses simple uniaxial experiments to measure the variability in the forming limits of the weld region, and uses a theoretical forming limit diagram calculation to establish a probabilistic distribution of weld region imperfection using an M-K method approac

Failure of JoAnne's Global Fit to the Wilson Coefficients in Rare B Decays: A Left-Right Model Example

In the Standard Model and many of its extensions, it is well known that all of the observables associated with the rare decays $b\to s\gamma$ and $b\to s\ell^+\ell^-$ can be expressed in terms of the three Wilson coefficients, $C_{7L,9L,10L}(\mu \sim m_b)$, together with several universal kinematic functions. In particular it has been shown that the numerical values of these coefficients can be uniquely extracted by a three parameter global fit to data obtainable at future $B$-factories given sufficient integrated luminosity. In this paper we examine if such global fits are also sensitive to new operators beyond those which correspond to the above coefficients, i.e., whether is it possible that new operators can be of sufficient importance for the three parameter fit to fail and for this to be experimentally observable. Using the Left-Right Symmetric Model as an example of a scenario with an extended operator basis, we demonstrate via Monte Carlo techniques that such a possibility can indeed be realized. In some sense this potential failure of the global fit approach can actually be one of its greatest successes in identifying the existence of new physics.Comment: 30 pages, 6 figure

Hybridization but No Evidence for Backcrossing and Introgression in a Sympatric Population of Great Reed Warblers and Clamorous Reed Warblers

Hybridization is observed frequently in birds, but often it is not known whether the hybrids are fertile and if backcrossing occurs. The breeding ranges of the great reed warbler (Acrocephalus arundinaceus) and the clamorous reed warbler (A. stentoreus) overlap in southern Kazakhstan and a previous study has documented hybridization in a sympatric population. In the present study, we first present a large set of novel microsatellite loci isolated and characterised in great reed warblers. Secondly, we evaluate whether hybridization in the sympatric breeding population has been followed by backcrossing and introgression

Direct CP Violation in B -> X_s gamma Decays as a Signature of New Physics

We argue that the observation of a sizable direct CP asymmetry A_{CP} in the inclusive decays B -> X_s gamma would be a clean signal of New Physics. In the Standard Model, A_{CP} can be calculated reliably and is found to be below 1% in magnitude. In extensions of the Standard Model with new CP-violating couplings, large CP asymmetries are possible without conflicting with the experimental value of the branching ratio for the decays B -> X_s gamma. In particular, large asymmetries arise naturally in models with enhanced chromo-magnetic dipole operators. Some generic examples of such models are explored and their implications for the semileptonic branching ratio and charm yield in B decays discussed.Comment: several references added and some numerical results updated to include QED corrections (version to appear in Physical Review D

Hybridization in parasites: consequences for adaptive evolution, pathogenesis and public health in a changing world

[No abstract available