Antarctic Meteorites: A Statistical Look at a Uniquely Valuable Resource

As of the end of the 2018-19 field season, the U.S. Antarctic meteorite program has surpassed 23,000 meteorites collected. The U.S. collection is valuable in that it is classified in its entirety. The systematic methods employed to collect the meteorites have provided meteorites of more than 40 types, many of which are the first of their type ever recognized. One of the early drivers for consistent and methodical characterization of the entire U.S. Antarctic collection was to allow statistical comparisons. Early statistical assessments of the U.S. Antarctic collection examined mass distributions and the relative frequency of meteorite types as well as comparisons to a defined set of modern falls. Using these statistics argued that the flux of H chondrites changed over time used model size distributions to deconstruct the contribution of wind movement, meteorite supply and search losses to the Antarctic collection. Mass-based statistics and size distribution comparisons were examined by investigated various aspects of the statistics, including comparison with modern falls/Saharan finds. Also discuss geospatial statistics provides a comprehensive overview of the statistics of the Antarctic collections for the first 35 seasons of U.S. collection by ANSMET. Here we build upon that assessment and that from

Exploring the Cosmic Evolution of Habitability with Galaxy Merger Trees

We combine inferred galaxy properties from a semi-analytic galaxy evolution model incorporating dark matter halo merger trees with new estimates of supernova and gamma ray burst rates as a function of metallicity from stellar population synthesis models incorporating binary interactions. We use these to explore the stellar mass fraction of galaxies irradiated by energetic astrophysical transients and its evolution over cosmic time, and thus the fraction which is potentially habitable by life like our own. We find that 18 per cent of the stellar mass in the Universe is likely to have been irradiated within the last 260 Myr, with GRBs dominating that fraction. We do not see a strong dependence of irradiated stellar mass fraction on stellar mass or richness of the galaxy environment. We consider a representative merger tree as a Local Group analogue, and find that there are galaxies at all masses which have retained a high habitable fraction (>40 per cent) over the last 6 Gyr, but also that there are galaxies at all masses where the merger history and associated star formation have rendered galaxies effectively uninhabitable. This illustrates the need to consider detailed merger trees when evaluating the cosmic evolution of habitability.Comment: 11 page, 10 figures. MNRAS accepted 13th Dec 2017. Updated to match accepted version, with additional discussion of metallicity effect

British research in accounting and finance (2001–2007): the 2008 research assessment exercise

No abstract available

Workshop report: Workshop on psychiatric prescribing and psychology testing and intervention in children and adults with Duchenne muscular dystrophy

This workshop aimed at summarising knowledge and key issues in psychiatric prescribing and psychological testing in children and adults with Duchenne muscular dystrophy (DMD). It comprised clinicians and patient representatives from the UK and the Netherlands. The following topics were discussed: a model for capturing the range of non-motor problems in the domains of cognition, learning, emotion and behaviour; psychosocial screening tools for use with children and adults; assessing neurocognitive functioning in children and adults; parent and teacher perspectives on psychosocial needs; and psychopharmacological treatment for affective disorders, anxiety disorders, obsessive compulsive disorder, attention deficit hyperactivity disorder (ADHD) and insomnia. Some key considerations included: the need for tools used to assess behavioural and psychosocial functioning to consider motor aspects in DMD; to understand more about working memory performance; the need for early interventions for automatisation problems, which affect reading and arithmetic; appropriate selection of tests for neuropsychology assessments; in schools, acknowledging the range of psychosocial risks and gathering evidence of psychosocial needs; the suitability of selective serotonin reuptake inhibitors for mood and anxiety disorders; the use of stimulant medications for ADHD; melatonin use for insomnia; the cautious use of benzodiazepines; and the need for improving pathways for psychosocial care

Composition of a chemical signalling trait varies with phylogeny and precipitation across an Australian lizard radiation

The environment presents challenges to the transmission and detection of animal signalling systems, resulting in selective pressures that can drive signal divergence amongst populations in disparate environments. For chemical signals, climate is a potentially important selective force because factors such as temperature and moisture influence the persistence and detection of chemicals. We investigated an Australian lizard radiation (Heteronotia) to explore relationships between a sexually dimorphic chemical signalling trait (epidermal pore secretions) and two key climate variables: temperature and precipitation. We reconstructed the phylogeny of Heteronotia with exon capture phylogenomics, estimated phylogenetic signal in amongst-lineage chemical variation and assessed how chemical composition relates to temperature and precipitation using multivariate phylogenetic regressions. High estimates of phylogenetic signal indicate that the composition of epidermal pore secretions varies amongst lineages in a manner consistent with Brownian motion, although there are deviations to this, with stark divergences coinciding with two phylogenetic splits. Accounting for phylogenetic non-independence, we found that amongst-lineage chemical variation is associated with geographic variation in precipitation but not temperature. This contrasts somewhat with previous lizard studies, which have generally found an association between temperature and chemical composition. Our results suggest that geographic variation in precipitation can affect the evolution of chemical signalling traits, possibly influencing patterns of divergence amongst lineages and species

Whole body and splanchnic amino acid metabolism in sheep during an acute endotoxin challenge

Acknowledgements The expertise of A. Graham Calder and Susan Anderson for the various stable isotope analyses is gratefully recognised. Ngaire Dennison is also thanked for her surgical expertise with the trans-splanchnic tissue catheter preparations. This study was supported by funds provided to the Rowett Institute of Nutrition and Health, University of Aberdeen and Biomathematics and Statistics Scotland by the Rural and Environment Science and Analytical Services Division of the Scottish Government. S. O. H. was a recipient of a FoRST (NZ) award to study abroad.Peer reviewedPostprin

Initiation of speciation across multiple dimensions in a rock-restricted, tropical lizard

Population isolation and concomitant genetic divergence, resulting in strong phylogeographical structure, is a core aspect of speciation initiation. If and how speciation then proceeds and ultimately completes depends on multiple factors that mediate reproductive isolation, including divergence in genomes, ecology and mating traits. Here we explored these multiple dimensions in two young (Plio-Pleistocene) species complexes of gekkonid lizards (Heteronotia) from the Kimberley–Victoria River regions of tropical Australia. Using mitochondrial DNA screening and exon capture phylogenomics, we show that the rock-restricted Heteronotia planiceps exhibits exceptional fine-scale phylogeographical structure compared to the codistributed habitat generalist Heteronotia binoei. This indicates pervasive population isolation and persistence in the rock-specialist, and thus a high rate of speciation initiation across this geographically complex region, with levels of genomic divergence spanning the “grey zone” of speciation. Proximal lineages of H. planiceps were often separated by different rock substrates, suggesting a potential role for ecological isolation; however, phylogenetic incongruence and historical introgression were inferred between one such pair. Ecomorphological divergence among lineages within both H. planiceps and H. binoei was limited, except that limestone-restricted lineages of H. planiceps tended to be larger than rock-generalists. By contrast, among-lineage divergence in the chemical composition of epidermal pore secretions (putative mating trait) exceeded ecomorphology in both complexes, but with less trait overlap among lineages in H. planiceps. This system—particularly the rock-specialist H. planiceps—highlights the role of multidimensional divergence during incipient speciation, with divergence in genomes, ecomorphology and chemical signals all at play at very fine spatial scales

Observations of Low Frequency Solar Radio Bursts from the Rosse Solar-Terrestrial Observatory

The Rosse Solar-Terrestrial Observatory (RSTO; www.rosseobservatory.ie) was established at Birr Castle, Co. Offaly, Ireland (53 05'38.9", 7 55'12.7") in 2010 to study solar radio bursts and the response of the Earth's ionosphere and geomagnetic field. To date, three Compound Astronomical Low-cost Low-frequency Instrument for Spectroscopy and Transportable Observatory (CALLISTO) spectrometers have been installed, with the capability of observing in the frequency range 10-870 MHz. The receivers are fed simultaneously by biconical and log-periodic antennas. Nominally, frequency spectra in the range 10-400 MHz are obtained with 4 sweeps per second over 600 channels. Here, we describe the RSTO solar radio spectrometer set-up, and present dynamic spectra of a sample of Type II, III and IV radio bursts. In particular, we describe fine-scale structure observed in Type II bursts, including band splitting and rapidly varying herringbone features