6,517 research outputs found

    A new substrate for sampling deep river macroinvertebrates

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    We compared macroinvertebrate communities colonising multiplate samplers constructed from perspex or tempered hardboard (wood) with an alternative artificial substrate constructed from folded coconut fibre matting (coir) enclosed in nylon netting. Substrates were incubated for 62 days over January to March 2007 at six sites over 240 km along the Waikato River. The three substrates supported similar numbers of invertebrate taxa (27 - 29 taxa), but coir samples contained 71% of total invertebrate numbers from all substrates combined, compared with <17% for each type of multiplate sampler. Coir faunas were heavily dominated by the hydrobiid snail Potamopyrgus (84 % of numbers), and this taxon along with the amphipod Paracalliope comprised 58 - 66 % of invertebrates on both types of multiplate samplers. Analysis of a Bray-Curtis matrix suggested statistically significant differences in percent community composition between coir samplers and each type of multiplate sampler over the late summer study period. Densities per cm3 of Oligochaeta, Mollusca, and "other worms" (Platyhelminthes, Rhabdocoela, Nemertea and Hirudinea combined) were significantly higher in coir samples than one or both of the multiplate samplers. Results suggest coir samplers may provide a useful supplement to multiplate samplers for deep river invertebrate studies by collecting a different range of taxa, including those favouring cover and characteristic of depositional environments

    Tricarbonylchlorido(6'7'-dihydro-5’H-spiro[cyclopentane-1,6'-dipyrido-[3,2-d:2',3'-f][1,3]diazepine]-κ2N1,N11)-rhenium(I)

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    In the title compound, [ReCl(C15H16N4)(CO)3], the ReI ion is coordinated in a distorted octahedral geometry by one Cl atom, two N atoms of the bidentate ligand and three carbonyl groups. The cyclopentane group is orientated in a transoid fashion with respect to the chloride ligand. The dihedral angle between the pryridine rings is 10.91 (12)°. In the crystal, N-H...Cl hydrogen bonds link complex molecules, forming a two-dimensional network parallel to (001)

    Tricarbonylchlorido(6’,7’-dihydro-5’H-spiro[cyclohexane-1,6’-dipyrido[3,2-d :2’,3’-f][1,3]diazepine]-κ2N1,N11)rhenium(I)

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    In the title compound, [ReCl(C16H18N4)(CO)3], the ReI ion is coordinated in a distorted octahedral geometry by one Cl atom, two N atoms of the bidentate ligand and three carbonyl groups. The cyclohexane group is orientated in a transoid fashion with respect to the chloride ligand. In the crystal, N-H...Cl hydrogen bonds link complex molecules, forming a two-dimensional network parallel to (100)

    Fit for work? Health, employability and challenges for the UK welfare reform agenda

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    This article introduces a special issue of Policy Studies entitled “Fit for work? Health, employability and challenges for the UK welfare reform agenda”. Growing from a shared concern over the need to expand the evidence base around the processes that led to large numbers of people claiming disability benefits in the UK, it brings together contributions from leading labour market and social policy researchers providing evidence and commentary on major reforms to Incapacity Benefit (IB) in the UK. This special issue address three key questions: what are the main causes of the long-term rise in the number of people claiming IBs; what will reduce the number of claimants; and what is likely to deliver policy effectively and efficiently? This introduction first explains and examines the challenges to reforms to IB in the UK, and then, in conclusion, highlights the answers to the previous three questions – first, labour market restructuring and marginalisation have driven the rise in numbers claiming IBs. Second, economic regeneration in the Britain’s less prosperous areas coupled with intensive and sustained supply-side support measures will bring numbers down. Third, delivery need to be flexible and tailored to individual needs and needs to be able to access local and expert knowledge in a range of organisations, including Job Centre Plus, the NHS as well as the private and voluntary sectors

    Radial Color Gradients in K+A Galaxies in Distant Clusters of Galaxies

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    Galaxies in rich clusters with z \gtrsim 0.3 are observed to have a higher fraction of photometrically blue galaxies than their nearby counterparts. This raises the important question of what environmental effects can cause the termination of star formation between z \approx 0.3 and the present. The star formation may be truncated due to ram-pressure stripping, or the gas in the disk may be depleted by an episode of star formation caused by some external perturbation. To help resolve this issue, surface photometry was carried out for a total of 70 early-type galaxies in the cluster Cl1358+62, at z \sim 0.33, using two-color images from the Hubble Archive. The galaxies were divided into two categories based on spectroscopic criteria: 24 are type K+A (e.g., strong Balmer lines, with no visible emission lines), while the remaining 46 are in the control sample with normal spectra. Radial color profiles were produced to see if the K+A galaxies show bluer nuclei in relation to their surrounding disks. Specifically, a linear gradient was fit to the radial color profile of each galaxy. We find that the K+A galaxies on average tend to have slightly bluer gradients towards the center than the normals. A Kolmogorov-Smirnov two-sample test has been applied to the two sets of color gradients. The result of the test indicates that there is only a \sim2% probability that the K+A and normal samples are drawn from the same parent distribution. There is a possible complication from a trend in the apparent magnitude vs. color gradient relation, but overall our results favor the centralized star formation scenario as an important process in the evolution of galaxies in dense clusters.Comment: 16 pages, 12 figures, accepted for publication in A

    Longitudinal Study of Body Mass Index in Young Males and the Transition to Fatherhood.

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    Despite a growing understanding that the social determinants of health have an impact on body mass index (BMI), the role of fatherhood on young men's BMI is understudied. This longitudinal study examines BMI in young men over time as they transition from adolescence into fatherhood in a nationally representative sample. Data from all four waves of the National Longitudinal Study of Adolescent Health supported a 20-year longitudinal analysis of 10,253 men beginning in 1994. A "fatherhood-year" data set was created and changes in BMI were examined based on fatherhood status (nonfather, nonresident father, resident father), fatherhood years, and covariates. Though age is positively associated with BMI over all years for all men, comparing nonresident and resident fathers with nonfathers reveals different trajectories based on fatherhood status. Entrance into fatherhood is associated with an increase in BMI trajectory for both nonresident and resident fathers, while nonfathers exhibit a decrease over the same period. In this longitudinal, population-based study, fatherhood and residence status play a role in men's BMI. Designing obesity prevention interventions for young men that begin in adolescence and carry through young adulthood should target the distinctive needs of these populations, potentially improving their health outcomes

    Plasmonic light yield enhancement of a liquid scintillator

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    We demonstrate modifications to the light yield properties of an organic liquid scintillator due to the localization of the tertiary fluorophore component to the surface of Ag-core silica-shell nanoparticles. We attribute this enhancement to the near-field interaction of Ag nanoparticle plasmons with these fluor molecules. The scintillation light yield enhancement is shown to be equal to the fluorescence enhancement within measurement uncertainties. With a suitable choice of plasmon energy and scintillation fluor, this effect may be used to engineer scintillators with enhanced light yields for radiation detection applications

    Climate Variability and Ross River Virus Transmission in Townsville Region, Australia 1985 to 1996

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    Background How climate variability affects the transmission of infectious diseases at a regional level remains unclear. In this paper, we assessed the impact of climate variation on the Ross River virus (RRv) transmission in the Townsville region, Queensland, north-east Australia. Methods Population-based information was obtained on monthly variations in RRv cases, climatic factors, sea level, and population growth between 1985 and 1996. Cross-correlations were computed for a series of associations between climate variables (rainfall, maximum temperature, minimum temperature, relative humidity and high tide) and the monthly incidence of RRv disease over a range of time lags. The impact of climate variability on RRv transmission was assessed using the seasonal auto-regressive integrated moving average (SARIMA) model. Results There were significant correlations of the monthly incidence of RRv to rainfall, maximum temperature, minimum temperature and relative humidity, all at a lag of 2 months, and high tide in the current month. The results of SARIMA models show that monthly average rainfall (β=0.0012, p=0.04) and high tide (β=0.0262, p=0.01) were significantly associated with RRv transmission, although temperature and relative humidity did not seem to have played an important role in the Townsville region. Conclusions Rainfall, and high tide were likely to be key determinants of RRv transmission in the Townsville region
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