Comparing non-invasive surveying techniques for elusive, nocturnal mammals: a case study of the West European hedgehog (Erinaceus europaeus)

Monitoring changes in populations is fundamental for effective management. The West European hedgehog (Erinaceus europeaus) is of conservation concern in the UK because of recent substantial declines. Surveying hedgehogs is, however, problematic because of their nocturnal, cryptic behaviour. We compared the effectiveness of three methods (infra-red thermal camera, specialist search dog, spotlight) for detecting hedgehogs in three different habitats. Significantly more hedgehogs were detected, and at greater distance, using the camera and dog than the spotlight in amenity grassland and pasture; no hedgehogs were detected in woodland. Increasing ground cover reduced detection distances, with most detections (59.6%) associated with bare soil or mown grass; the dog was the only method that detected hedgehogs in vegetation taller than the target species’ height. The additional value of surveying with a detection dog is most likely to be realised in areas where badgers (Meles meles), an intra-guild predator, are and/or where sufficient ground cover is present; both would allow hedgehogs to forage further from refuge habitats such as hedgerows. Further consideration of the effectiveness of detection dogs for finding hedgehogs in nests, as well as developing techniques for monitoring this species in woodland, is warranted

Optically thick clumps: not the solution to the Wolf-Rayet wind momentum problem?

The hot star wind momentum problem η = Mν∞/(L/c)» much greater than 1 is revisited, and it is shown that the conventional belief, that it can be solved by a combination of clumping of the wind and multiple scattering of photons, is not self-consistent for optically thick clumps. Clumping does reduce the mass loss rate M, and hence the momentum supply, required to generate a specified radio emission measure epsilon, while multiple scattering increases the delivery of momentum from a specified stellar luminosity L. However, in the case of thick clumps, when combined the two effects act in opposition rather than in unison since clumping reduces multiple scattering. From basic geometric considerations, it is shown that this reduction in momentum delivery by clumping more than offsets the reduction in momentum required, for a specified ε. Thus the ratio of momentum deliverable to momentum required is maximal for a smooth wind and the momentum problem remains for the thick clump case. In the case of thin clumps, all of the benefit of clumping in reducing η lies in reducing M for a given ε so that extremely small filling factors f ≈ 10-4 are needed. It is also shown that clumping affects the inference of M from radio ε not only by changing the emission measure per unit mass but also by changing the radio optical depth unity radius Rrad, and hence the observed wind volume, at radio wavelengths. In fact, for free-free opacity proportional to αn2, contrary to intuition, Rrad increases with increasing clumpiness

Time Dependent Monte Carlo Radiative Transfer Calculations For 3-Dimensional Supernova Spectra, Lightcurves, and Polarization

We discuss Monte-Carlo techniques for addressing the 3-dimensional time-dependent radiative transfer problem in rapidly expanding supernova atmospheres. The transfer code SEDONA has been developed to calculate the lightcurves, spectra, and polarization of aspherical supernova models. From the onset of free-expansion in the supernova ejecta, SEDONA solves the radiative transfer problem self-consistently, including a detailed treatment of gamma-ray transfer from radioactive decay and with a radiative equilibrium solution of the temperature structure. Line fluorescence processes can also be treated directly. No free parameters need be adjusted in the radiative transfer calculation, providing a direct link between multi-dimensional hydrodynamical explosion models and observations. We describe the computational techniques applied in SEDONA, and verify the code by comparison to existing calculations. We find that convergence of the Monte Carlo method is rapid and stable even for complicated multi-dimensional configurations. We also investigate the accuracy of a few commonly applied approximations in supernova transfer, namely the stationarity approximation and the two-level atom expansion opacity formalism.Comment: 16 pages, ApJ accepte

XMM-Newton observations of the nitrogen-rich Wolf-Rayet star WR 1

We present XMM-Newton results for the X-ray spectrum from the N-richWolf-Rayet (WR) star WR1. The EPIC instrument was used to obtain a medium-resolution spectrum. The following features characterize this spectrum: ( a) significant emission "bumps" appear that are coincident with the wavelengths of typical strong lines, such as MgXI, SiXIII, and SXV; (b) little emission is detected above 4 keV, in contrast to recent reports of a hard component in the stars WR 6 and WR 110 which are of similar subtype; and ( c) evidence for sulfur K-edge absorption at about 2.6 keV, which could only arise from absorption of X- rays by the ambient stellar wind. The lack of hard emission in our dataset is suggestive that WR 1 may truly be a single star, thus representing the first detailed X-ray spectrum that isolates the WR wind alone ( in contrast to colliding wind zones). Although the properties of the S-edge are not well- constrained by our data, it does appear to be real, and its detection indicates that at least some of the hot gas in WR 1 must reside interior to the radius of optical depth unity for the total absorptive opacity at the energy of the edge

The conspicuous absence of X-ray emission from carbon-enriched Wolf-Rayet stars

The carbon-rich WC5 star WR 114 was not detected during a 15.9 ksec XMM-Newton observation, implying an upper limit to the X- ray luminosity of L-X less than or similar to 2.5 x 10(30) erg s(-1) and to the X-ray to bolometric luminosity ratio of L- X/L(bo)l less than or similar to 4 x 10(-9). This confirms indications from earlier less sensitive measurements that there has been no convincing X-ray detection of any single WC star. This lack of detections is reinforced by XMM-Newton and Chandra observations of WC stars. Thus the conclusion has to be drawn that the stars with radiatively-driven stellar winds of this particular class are insignificant X-ray sources. We attribute this to photoelectronic absorption by the stellar wind. The high opacity of the metal-rich and dense winds from WC stars puts the radius of optical depth unity at hundreds or thousands of stellar radii for much of the X-ray band. We believe that the essential absence of hot plasma so far out in the wind exacerbated by the large distances and correspondingly high ISM column densities makes the WC stars too faint to be detectable with current technology. The result also applies to many WC stars in binary systems, of which only about 20% are identified X-ray sources, presumably due to colliding winds

Evaluating quality and impact of acute paediatric inpatient care: Defining the domains for a Person Centred Outcome Measure (PCOM) in children and young people admitted with self-harm or eating disorders

Background and purpose: In the United Kingdom, the prevalence of children and young people (CYP), up to the age of 18 years, accessing acute paediatric inpatient care with mental health problems is increasing, with self-harm and eating disorders particularly prevalent. This initial period of acute inpatient care can involve multiple assessments and interventions in order to meet physical, psychological and social needs. However, there is a distinct paucity of published literature reporting CYP service users’ experiences and outcomes of being in receipt of non-specialist inpatient care. Therefore this project aimed to undertake the preliminary work in developing a Person Centred Outcome Measure (PCOM) for this patient group by identifying the domains for a PCOM and establishing how such a measure could be implemented. Methods: A two phase sequential design was adopted which involved: (1) a rapid review of the literature and (2) an evaluation of experiences and outcomes through stakeholder engagement events with children and young people admitted with self-harm or eating disorders, their parents and carers, and professionals from health, social care and education. Findings: Rapid review of the literature • There is a lack of reported outcomes relating to CYP admitted to inpatient care with self-harm within the literature. • Outcomes reported by CYP appear to relate to aspects of care delivery, communication and the inpatient environment; • CYP reports predominantly relate to deficits in service provision which is recognised to negatively impact on experience and inhibit recovery and outcome. Findings: Stakeholder workshops • In total 96 CYP, parents and carers, and professionals participated in the stakeholder event. • Disparities in experiences and the implied quality of being in receipt of care were identified. • Synthesis of findings identified five domains that could be used to develop a PCOM that included: Privacy and surveillance; Receiving holistic care; Making choices and being understood through timely, relevant and appropriate communication; Working together to plan and achieve care goals; and Respect and empowerment • Variation was evident between CYP stakeholders as to the acceptability of when and how outcomes are measured. Conclusion: Findings from this project provide the foundations for a PCOM for CYP admitted to acute paediatric care with self harm or eating disorders to be developed, tested, implemented and evaluated. The domains identified have the potential to be further developed and validated as an instrument with a larger and more diverse sample of CYP

XMM-Newton X-ray study of early type stars in the Carina OB1 association

<p><b>Aims:</b> X-ray properties of the stellar population in the Carina OB1 association are examined with special emphasis on early-type stars. Their spectral characteristics provide some clues to understanding the nature of X-ray formation mechanisms in the winds of single and binary early-type stars.</p> <p><b>Methods:</b> A timing and spectral analysis of five observations with XMM-Newton is performed using various statistical tests and thermal spectral models.</p> <p><b>Results:</b> 235 point sources have been detected within the field of view. Several of these sources are probably pre-main sequence stars with characteristic short-term variability. Seven sources are possible background AGNs. Spectral analysis of twenty four sources of type OB and WR 25 was performed. We derived spectral parameters of the sources and their fluxes in three energy bands. Estimating the interstellar absorption for every source and the distance to the nebula, we derived X-ray luminosities of these stars and compared them to their bolometric luminosities. We discuss possible reasons for the fact that, on average, the observed X-ray properties of binary and single early type stars are not very different, and give several possible explanations.</p&gt