Localised Badger Culling Increases Risk of Herd Breakdown on Nearby, Not Focal, Land

Bovine tuberculosis is an important disease affecting the UK livestock industry. Controlling bovine tuberculosis (TB) is made more complex by the presence of a wildlife host, the Eurasian badger, Meles meles. Repeated large-scale badger culls implemented in the Randomised Badger Culling Trial (RBCT) were associated with decreased cattle risks inside the culling area, but also with increased cattle risks up to the 2km outside the culling area. Intermediate reductions in badger density, as achieved by localised reactive culling in the RBCT, significantly increased cattle TB. Using a matched-pairs case-control study design (n = 221 pairs of cattle herds), we investigated the spatial scale over which localised badger culling had its biggest impact. We found that reactive badger culling had a significant positive association with the risk of cattle TB at distances of 1-3km and 3-5km, and that no such association existed over shorter distances (<1km). These findings indicate that localised badger culls had significant negative effects, not on the land on which culling took place, but, perhaps more importantly, on adjoining lands and farms

The competence of cognitively vulnerable participants to consent to biomedical research.

Enhanced knowledge of the nature and causes of mental disorder and the neurogenetic basis of many conditions of youth and old age have led increasingly to a need for the recruitment of ‘cognitively vulnerable’ participants in biomedical research. These include adults with mental disorder or mental retardation and healthy adolescents whose decisional competence often falls in the ‘grey area’ between obvious competence and obvious incompetence. As a result, they may not be recognised as having the legal capacity to make such decisions themselves. At the core of the debate surrounding the ethics of participation of cognitively vulnerable participants in research is when, if at all, we should judge them decisionally competent to consent to or refuse research participation on their own behalf and when they should be judged incompetent in this respect. In this thesis, I develop a theoretical framework for making judgments about decisional competence to consent to biomedical research on behalf of five discrete groups of cognitively vulnerable individuals. I call this a framework a theory of precautionary task or decisional competence judgment (PTDCJ). It derives from precautionary moral reasoning informed by Alan Gewirth’s Principle of Generic Consistency (PGC) and is supported by empirical studies in psychiatry. Using this framework, I argue that we can make morally defensible judgments about the competence or incompetence of a potential participant to give contemporaneous consent to research by having regard to whether a judgment of competence would be more harmful to the generic rights of the potential participant (and any other agents concerned) than a judgment of incompetence. I also use this argument to justify an account of supported decision-making in research. I end the thesis by applying this framework to evaluate the extent to which this approach is evident in existing legal provisions and ethical guidelines in England and Wales and the United States

Drivers of Batrachochytrium dendrobatidis infection load, with evidence of infection tolerance in adult male toads (Bufo spinosus)

Chytridiomycosis is affecting hundreds of amphibian species worldwide, but while in tropical areas, adult individuals have been the focus of most investigations, the exact role played by infection intensity of breeding adults is not well understood in temperate areas. We conducted mark–recapture–capture surveys during spiny common toad breeding seasons from 2006 to 2018 at the site of the first recorded outbreak of chytridiomycosis in Europe, the Peñalara Massif (Sierra de Guadarrama National Park, central Spain), and collected infection samples and several variables related to the reproductive effort of male individuals. We used general linear mixed models to evaluate the contribution of study variables on the infection loads of adult male toads exhibited at their capturing date. We also analysed the differences on several male characteristics between the pond with the largest breeding population against the rest of the ponds. We found that the duration of time spent in the waterbody and the condition of the host predicted infection loads. Animals of good physical condition, that spent longer in water, have higher infection levels than individuals with the opposite set of traits. The pond supporting the largest breeding population housed smaller male toads and in poorer condition. Our results are consistent with a shift in reproductive strategy in response to infection and potentially a strategy of tolerance, rather than resistance to infection. These findings have applications for disease mitigation and theoretical implications related to the trade-offs made and the evolution of traits in response to the disease

The WIRCAM Deep Infrared Cluster Survey I: Groups and Clusters at z > 1.1

We use CFHTLS deep optical data, WIRCam Deep Survey (WIRDS) NIR data and XMM data to identify z>1.1 clusters in the CFHTLS D1 and D4 fields. Counterparts to such clusters can not be identified without deep NIR data and as such the total of =1deg2 of J , H & Ks band imaging provided by WIRDS is an indispensable tool in such work. Using public XMM X-ray data, we identify extended X-ray sources in the two fields. The resulting catalogue of extended X-ray sources was analyzed for optical/NIR counterparts, using a red-sequence algorithm. Redshifts of candidate groups and clusters were estimated using the median photometric redshifts of detected counterparts and where available spectroscopic data. Additionally, we surveyed X-ray point sources for potential group systems at the limit of our detection range in the X-ray data. A catalogue of z > 1.1 cluster candidates in the two fields has been compiled and cluster masses, radii and temperatures have been estimated using the scaling relations. The catalogue consists of 15 z > 1.1 candidates. Three of the detections are previously published extended X-ray sources. Of note is JKSC 041 for which we identify possible structures at z = 0.8, z = 0.96, z = 1.13 and z = 1.49. We also make an independent detection of the massive cluster, XMMXCS J2215.9-1738. We use the z > 1.1 catalogue to compare the cluster number counts in these fields with models based on WMAP 7-year cosmology and find that the models slightly over-predict the observations, whilst at z>1.5 we do not detect any clusters. We note that cluster number counts at z > 1.1 are highly sensitive to the cosmological model, however a significant reduction in present statistical (due to available survey area) and systematic (due to cluster scaling relations) uncertainties is required in order to confidently constrain cosmological parameters using cluster number counts at high redshift.Comment: 22 pages, 22 figures, Accepted 4 August 201

X-Ray Groups of Galaxies in the Aegis Deep and Wide Fields

We present the results of a search for extended X-ray sources and their corresponding galaxy groups from 800-ks Chandra coverage of the All-wavelength Extended Groth Strip International Survey (AEGIS). This yields one of the largest X-ray selected galaxy group catalogs from a blind survey to date. The red-sequence technique and spectroscopic redshifts allow us to identify 100$$ of reliable sources, leading to a catalog of 52 galaxy groups. The groups span the redshift range $z\sim0.066-1.544$ and virial mass range $M_{200}\sim1.34\times 10^{13}-1.33\times 10^{14}M_\odot$. For the 49 extended sources which lie within DEEP2 and DEEP3 Galaxy Redshift Survey coverage, we identify spectroscopic counterparts and determine velocity dispersions. We select member galaxies by applying different cuts along the line of sight or in projected spatial coordinates. A constant cut along the line of sight can cause a large scatter in scaling relations in low-mass or high-mass systems depending on the size of cut. A velocity dispersion based virial radius can more overestimate velocity dispersion in comparison to X-ray based virial radius for low mass systems. There is no significant difference between these two radial cuts for more massive systems. Independent of radial cut, overestimation of velocity dispersion can be created in case of existence of significant substructure and also compactness in X-ray emission which mostly occur in low mass systems. We also present a comparison between X-ray galaxy groups and optical galaxy groups detected using the Voronoi-Delaunay method (VDM) for DEEP2 data in this field.Comment: Accepted for publication in AP

Quasar Sightline and Galaxy Evolution (QSAGE) -- III. The mass-metallicity and fundamental metallicity relation of z≈z \approx 2.2 galaxies

We present analysis of the mass-metallicity relation (MZR) for a sample of 67 [OIII]-selected star-forming galaxies at a redshift range of $z=1.99 - 2.32$ ($z_{\text{med}} = 2.16$) using \emph{Hubble Space Telescope} Wide Field Camera 3 grism spectroscopy from the Quasar Sightline and Galaxy Evolution (QSAGE) survey. Metallicities were determined using empirical gas-phase metallicity calibrations based on the strong emission lines [OII]3727,3729, [OIII]4959,5007 and H$\beta$. Star-forming galaxies were identified, and distinguished from active-galactic nuclei, via Mass-Excitation diagrams. Using $z\sim0$ metallicity calibrations, we observe a negative offset in the $z=2.2$ MZR of $\approx -0.51$ dex in metallicity when compared to locally derived relationships, in agreement with previous literature analysis. A similar offset of $\approx -0.46$ dex in metallicity is found when using empirical metallicity calibrations that are suitable out to $z\sim5$, though our $z=2.2$ MZR, in this case, has a shallower slope. We find agreement between our MZR and those predicted from various galaxy evolution models and simulations. Additionally, we explore the extended fundamental metallicity relation (FMR) which includes an additional dependence on star formation rate (SFR). Our results consistently support the existence of the FMR, as well as revealing an offset of $0.28\pm0.04$ dex in metallicity compared to locally-derived relationships, consistent with previous studies at similar redshifts. We interpret the negative correlation with SFR at fixed mass, inferred from an FMR existing for our sample, as being caused by the efficient accretion of metal-poor gas fuelling SFR at cosmic noon.Comment: 15 pages, 10 figures. This paper has been accepted for publication in MNRA

The galaxy cluster Ysz-Lx and Ysz-M relations from the WMAP 5-yr data

We use multifrequency matched filters to estimate, in the WMAP 5-year data, the Sunyaev-Zel'dovich (SZ) fluxes of 893 ROSAT NORAS/REFLEX clusters spanning the luminosity range Lx,[0.1-2.4]keV = 2 10^{41} - 3.5 10^{45} erg s^{-1}. The filters are spatially optimised by using the universal pressure profile recently obtained from combining XMM-Newton observations of the REXCESS sample and numerical simulations. Although the clusters are individually only marginally detected, we are able to firmly measure the SZ signal (>10 sigma) when averaging the data in luminosity/mass bins. The comparison between the bin-averaged SZ signal versus luminosity and X-ray model predictions shows excellent agreement, implying that there is no deficit in SZ signal strength relative to expectations from the X-ray properties of clusters. Using the individual cluster SZ flux measurements, we directly constrain the Y500-Lx and Y500-M500 relations, where Y500 is the Compton y-parameter integrated over a sphere of radius r500. The Y500-M500 relation, derived for the first time in such a wide mass range, has a normalisation Y*500=[1.60 pm 0.19] 10^{-3} arcmin^2 at M500=3 10^{14} h^{1} Msun, in excellent agreement with the X-ray prediction of 1.54 10^{-3} arcmin^2, and a mass exponent of alpha=1.79 pm 0.17, consistent with the self-similar expectation of 5/3. Constraints on the redshift exponent are weak due to the limited redshift range of the sample, although they are compatible with self-similar evolution.Comment: Version accepted for publication in Astronomy and Astrophysic

Exploring the galaxy cluster-group transition regime at high redshifts: Physical properties of two newly detected z > 1 systems

Context: Multi-wavelength surveys for clusters of galaxies are opening a window on the elusive high-redshift (z>1) cluster population. Well controlled statistical samples of distant clusters will enable us to answer questions about their cosmological context, early assembly phases and the thermodynamical evolution of the intracluster medium. Aims: We report on the detection of two z>1 systems, XMMU J0302.2-0001 and XMMU J1532.2-0836, as part of the XMM-Newton Distant Cluster Project (XDCP) sample. We investigate the nature of the sources, measure their spectroscopic redshift and determine their basic physical parameters. Methods: The results of the present paper are based on the analysis of XMM-Newton archival data, optical/near-infrared imaging and deep optical follow-up spectroscopy of the clusters. Results: We confirm the X-ray source XMMU J0302.2-0001 as a gravitationally bound, bona fide cluster of galaxies at spectroscopic redshift z=1.185. We estimate its M500 mass to (1.6+/-0.3) times 10^{14} Msun from its measured X-ray luminosity. This ranks the cluster among intermediate mass system. In the case of XMMU J1532.2-0836 we find the X-ray detection to be coincident with a dynamically bound system of galaxies at z=1.358. Optical spectroscopy reveals the presence of a central active galactic nucleus, which can be a dominant source of the detected X-ray emission from this system. We provide upper limits of X-ray parameters for the system and discuss cluster identification challenges in the high-redshift low-mass cluster regime. A third, intermediate redshift (z=0.647) cluster, XMMU J0302.1-0000, is serendipitously detected in the same field as XMMU J0302.2-0001. We provide its analysis as well.Comment: Accepted to A&A, 13/04/2011. 15 pages, 18 figures, 5 tables, 2 appendice