Impact of inactivity and exercise on the vasculature in humans

The effects of inactivity and exercise training on established and novel cardiovascular risk factors are relatively modest and do not account for the impact of inactivity and exercise on vascular risk. We examine evidence that inactivity and exercise have direct effects on both vasculature function and structure in humans. Physical deconditioning is associated with enhanced vasoconstrictor tone and has profound and rapid effects on arterial remodelling in both large and smaller arteries. Evidence for an effect of deconditioning on vasodilator function is less consistent. Studies of the impact of exercise training suggest that both functional and structural remodelling adaptations occur and that the magnitude and time-course of these changes depends upon training duration and intensity and the vessel beds involved. Inactivity and exercise have direct “vascular deconditioning and conditioning” effects which likely modify cardiovascular risk

Observation of gravitational waves from the coalescence of a 2.5–4.5 M ⊙ compact object and a neutron star

We report the observation of a coalescing compact binary with component masses 2.5–4.5 M ⊙ and 1.2–2.0 M ⊙ (all measurements quoted at the 90% credible level). The gravitational-wave signal GW230529_181500 was observed during the fourth observing run of the LIGO–Virgo–KAGRA detector network on 2023 May 29 by the LIGO Livingston observatory. The primary component of the source has a mass less than 5 M ⊙ at 99% credibility. We cannot definitively determine from gravitational-wave data alone whether either component of the source is a neutron star or a black hole. However, given existing estimates of the maximum neutron star mass, we find the most probable interpretation of the source to be the coalescence of a neutron star with a black hole that has a mass between the most massive neutron stars and the least massive black holes observed in the Galaxy. We provisionally estimate a merger rate density of 55−47+127Gpc−3yr−1 for compact binary coalescences with properties similar to the source of GW230529_181500; assuming that the source is a neutron star–black hole merger, GW230529_181500-like sources may make up the majority of neutron star–black hole coalescences. The discovery of this system implies an increase in the expected rate of neutron star–black hole mergers with electromagnetic counterparts and provides further evidence for compact objects existing within the purported lower mass gap

Phylogenetic relationships in brown argus butterflies (Lepidoptera: Lycaenidae: Aricia) from north-western Europe

Lycaenid butterflies of the Aricia agestis-artaxerxes complex pose an unresolved taxonomic and conservation problem in north-western Europe. Two key issues require resolution: (i) how many species of Aricia occur in north-western Europe and what are their distributions?; (ii) how is the morphological variation observed in north-western Europe best explained? We investigated phylogenetic relationships and phylogeographic patterns in this species group using mitochondrial and nuclear markers in comparison with morphological variation. A 325 bp fragment of the mitochondrial cytochrome-b gene was sequenced from 179 individuals representing 18 populations from the UK and Scandinavia. Seventeen enzyme-coding loci were analysed from 538 individuals from the same populations. Highly congruent phylogenies between mitochondrial and allozyme markers demonstrate that the sample is composed of two closely related species, A. agestis and A. artaxerxes. Both marker types also suggest that Scottish and northern Scandinavian A. artaxerxes populations are conspecific, and consequently do not support the endemic status of A. artaxerxes in the UK. The subspecies division of British populations of A. artaxerxes is also not supported by phylogenetic analyses. Allozyme and mitochondrial analyses cluster two populations from the Peak District, UK, differently. The former suggests that they are A. artaxerxes whilst the latter suggests they are A. agestis. Further research is required to find the reason for this disagreement, which could be associated with the different dynamics of nuclear and mitochondrial genes across a hybrid zone between the two species. (C) 2002 The Linnean Society of London

Improving technical information use: what can be learnt from a manager's perspective?

Conservation practice reportedly suffers from low use of technical information. Understanding of factors that affect the influence of technical information on management decision-making is limited. We sought to identify leverage points for improved technical information dissemination in the New South Wales Parks and Wildlife Service, Australia, given the significant recent investments in monitoring and evaluation that had been made. We did so by exploring the inter-relationships between factors affecting the influence of different information types on management decisions. Results indicate that managers have a high inclination toward adaptive behavior, given they operate in an information poor environment. The most influential types of information were those that enabled interaction between information provider and recipient (e.g., staff experience and expertise). An analysis of the concordance in individuals' responses for different information types showed that neither accessibility nor organizational expectation of use was aligned with influence on decision-making. Alignment of responses also varied by work area. Raising expectations of information use or increasing access to particular types of information is therefore unlikely to result in an increase in influence on management decision-making. Rather than focussing on matching accessibility and expected use of particular information types, our results indicate that technical information uptake is best supported through existing peer networks tailored to specific work areas