21 research outputs found

    PCV23: VARIATION IN COSTS OF TREATING HYPERCHOLESTEROLEMIC PATIENTS IN FRANCE

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    The evolution of male ornamentation has long been the focus of sexual selection studies. However, evidence is accumulating that sexually selected traits can also be lost, although the process is ill-understood. In male fairy-wrens (Malurus spp.), early molt into the seasonal breeding plumage is critical for obtaining extra-pair paternity (EPP), which reaches very high levels in these socially monogamous songbirds. A notable exception is the purple-crowned fairy-wren, Malurus coronatus, which, like its congeners, breeds cooperatively, but where EPP is very rare. Nevertheless, males develop a conspicuous seasonal breeding plumage at highly variable times. Based on 6 years of molt data collected for 137 individuals, we investigated the adaptive significance of pre-breeding molt timing as a sexual signal under (near) genetic monogamy. Molt timing varied between and within individuals with age and climate: molt was completed earlier in older males and after wetter years. Despite its potential to act as a sexual signal of male quality, fitness benefits and costs of early molt appear limited: molt timing did not correlate with 1) the likelihood of gaining a breeding position; 2) female mate preference (EPP/cuckoldry, divorce); 3) female reproductive investment (breeding timing, clutch size, number of clutches); 4) breeding performance (hatching success, fledging success, fledgling survival, annual reproductive success); and 5) male survival. However, although molt timing did not predict which subordinates would become breeders, breeders molted earlier than subordinates. The lack of EPP in this species might imply relaxed sexual selection on early molt with potential to lead to trait disappearance

    Carbon nanotubes allow capture of krypton, barium and lead for multichannel biological X-ray fluorescence imaging

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    The desire to study biology in situ has been aided by many imaging techniques. Among these, X-ray fluorescence (XRF) mapping permits observation of elemental distributions in a multichannel manner. However, XRF imaging is underused, in part, because of the difficulty in interpreting maps without an underlying cellular ‘blueprint’; this could be supplied using contrast agents. Carbon nanotubes (CNTs) can be filled with a wide range of inorganic materials, and thus can be used as ‘contrast agents’ if biologically absent elements are encapsulated. Here we show that sealed single-walled CNTs filled with lead, barium and even krypton can be produced, and externally decorated with peptides to provide affinity for sub-cellular targets. The agents are able to highlight specific organelles in multiplexed XRF mapping, and are, in principle, a general and versatile tool for this, and other modes of biological imaging

    Data from: No fitness benefits of early molt in a fairy-wren: relaxed sexual selection under genetic monogamy?

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    The evolution of male ornamentation has long been the focus of sexual selection studies. However, evidence is accumulating that sexually selected traits can also be lost, although the process is ill-understood. In male fairy-wrens (Malurus spp.), early molt into the seasonal breeding plumage is critical for obtaining extra-pair paternity (EPP), which reaches very high levels in these socially monogamous songbirds. A notable exception is the purple-crowned fairy-wren, Malurus coronatus, which, like its congeners, breeds cooperatively, but where EPP is very rare. Nevertheless, males develop a conspicuous seasonal breeding plumage at highly variable times. Based on 6 years of molt data collected for 137 individuals, we investigated the adaptive significance of pre-breeding molt timing as a sexual signal under (near) genetic monogamy. Molt timing varied between and within individuals with age and climate: molt was completed earlier in older males and after wetter years. Despite its potential to act as a sexual signal of male quality, fitness benefits and costs of early molt appear limited: molt timing did not correlate with 1) the likelihood of gaining a breeding position; 2) female mate preference (EPP/cuckoldry, divorce); 3) female reproductive investment (breeding timing, clutch size, number of clutches); 4) breeding performance (hatching success, fledging success, fledgling survival, annual reproductive success); and 5) male survival. However, although molt timing did not predict which subordinates would become breeders, breeders molted earlier than subordinates. The lack of EPP in this species might imply relaxed sexual selection on early molt with potential to lead to trait disappearance

    Utilizing the gate-opening mechanism in ZIF-7 for adsorption discrimination between N<sub>2</sub>O and CO<sub>2</sub>

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    N<sub>2</sub>O is a greenhouse gas with tremendous global warming potential, and more importantly it also causes ozone depletion; thus, the separation of N<sub>2</sub>O from industrial processes has gained significant attention. We have demonstrated that N<sub>2</sub>O can be selectively separated from CO<sub>2</sub> using the zeolite imidazolate framework ZIF-7. The adsorption/desorption isotherms of both N<sub>2</sub>O and CO<sub>2</sub> in ZIF-7 indicate the gate-opening mechanism of this material and surprisingly, the threshold pressure for the gate opening with N<sub>2</sub>O is lower than that with CO<sub>2</sub>. Theoretical calculations indicate that both gas–host and gas–gas interaction energies for N<sub>2</sub>O are more favorable than those for CO<sub>2</sub>, giving rise to the difference in the threshold pressure between N<sub>2</sub>O and CO<sub>2</sub> in ZIF-7. Breakthrough experiments for N<sub>2</sub>O/CO<sub>2</sub> mixtures confirm that ZIF-7 is capable of separating N<sub>2</sub>O and CO<sub>2</sub> mixtures under the optimized conditions, in reasonable agreement with simulation results, making it a promising material for industrial applications
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