Discovery of a Magnetic DZ White Dwarf with Zeeman-Split Lines of Heavy Elements

A spectroscopic survey of previously-unstudied Luyten Half Second proper motion stars has resulted in the discoveries of two new cool magnetic white dwarfs. One (LHS 2273) is a routine DA star, T= 6,500K, with Zeeman-split H alpha and H beta, for which a simple model suggests a polar field strength of 18.5 MG viewed close to equator-on. However, the white dwarf LHS 2534 proves to be the first magnetic DZ showing Zeeman-split Na I and Mg I components, as well as Ca I and Ca II lines for which Zeeman components are blended. The Na I splittings result in a mean surface field strength estimate of 1.92 MG. Apart from the magnetic field, LHS 2534 is one of the most heavily-blanketed and coolest DZ white dwarfs at T ~ 6,000K.Comment: 7 pages, Astrophysical Journal (Letters), in pres

Metacarpophalangeal pattern profile analysis of a sample drawn from a North Wales population

This is tha author's PDF version of an article published in Annals of human biology© 2001. The definitive version is available at http://www.tandf.co.uk/journalsSexual dimorphism and population differences were investigated using metacarpophalangeal pattern profile (MCPP) analysis. Although it is an anthropmetric technique, MCPP analysis is more frequently used in genetic syndrome analysis and has been under-used in the study of human groups. The present analysis used a series of hand radiographics from Gwynedd, North Wales, to make comparisons, first, between the sexes within the sample and then with previously reported data from Japan. The Welsh sexes showed MCPP analyses that indicated size and shape differences but certain similarities in shape were also evident. Differences with the Japanese data were more marked. MCPP anlysis is a potentially useful anthropmetric technique but requires further statistical development

From fields to a super-cluster: the role of the environment at z=0.84 with HiZELS

At z=0, clusters are primarily populated by red, elliptical and massive galaxies, while blue, spiral and lower-mass galaxies are common in low-density environments. Understanding how and when these differences were established is of absolute importance for our understanding of galaxy formation and evolution, but results at high-z remain contradictory. By taking advantage of the widest and deepest H-alpha narrow-band survey at z=0.84 over the COSMOS and UKIDSS UDS fields, probing a wide range of densities (from poor fields to rich groups and clusters, including a confirmed super-cluster with a striking filamentary structure), we show that the fraction of star-forming galaxies falls continuously from ~40% in fields to approaching 0% in rich groups/clusters. We also find that the median SFR increases with environmental density, at least up to group densities - but only for low and medium mass galaxies, and thus such enhancement is mass-dependent at z~1. The environment also plays a role in setting the faint-end slope (alpha) of the H-alpha luminosity function. Our findings provide a sharper view on galaxy formation and evolution and reconcile previously contradictory results at z~1: stellar mass is the primary predictor of star formation activity, but the environment also plays a major role.Comment: 5 pages, 4 figures, to appear in the proceedings of JENAM 2010 S2: `Environment and the Formation of Galaxies: 30 years later', ASSP, Springe

Radio Weak Gravitational Lensing with VLA and MERLIN

We carry out an exploratory weak gravitational lensing analysis on a combined VLA and MERLIN radio data set: a deep (3.3 micro-Jy beam^-1 rms noise) 1.4 GHz image of the Hubble Deep Field North. We measure the shear estimator distribution at this radio sensitivity for the first time, finding a similar distribution to that of optical shear estimators for HST ACS data in this field. We examine the residual systematics in shear estimation for the radio data, and give cosmological constraints from radio-optical shear cross-correlation functions. We emphasize the utility of cross-correlating shear estimators from radio and optical data in order to reduce the impact of systematics. Unexpectedly we find no evidence of correlation between optical and radio intrinsic ellipticities of matched objects; this result improves the properties of optical-radio lensing cross-correlations. We explore the ellipticity distribution of the radio counterparts to optical sources statistically, confirming the lack of correlation; as a result we suggest a connected statistical approach to radio shear measurements.Comment: 16 pages with 19 figures, accepted for publication in MNRAS; Minor corrections to section 6.3; 2 references adde

Ascaris lumbricoides Infection Following School-Based Deworming in Western Kenya: Assessing the Role of Pupils' School and Home Water, Sanitation, and Hygiene Exposures.

Water, sanitation, and hygiene (WaSH) technologies and behaviors can prevent infection by soil-transmitted helminth species independently, but may also interact in complex ways. However, these interactions are poorly understood. The purpose of this study was to characterize how school and home WaSH exposures were associated with Ascaris lumbricoides infection and to identify relevant interactions between separate WaSH technologies and behaviors. A study was conducted among 4,404 children attending 51 primary schools in western Kenya. We used multivariable mixed effects logistic regression to characterize how various WaSH exposures were associated with A. lumbricoides infection after annual school-based deworming. Few WaSH behaviors and technologies were independently associated with A. lumbricoides infection. However, by considering relevant interdependencies between variables, important associations were elucidated. The association between handwashing and A. lumbricoides depended largely upon the pupils' access to an improved water source. Among pupils who had access to improved water sources, A. lumbricoides prevalence was lower for those who handwashed both at school and home compared with neither place (odds ratio: 0.38, 95% confidence interval: 0.18-0.83; P = 0.01). This study contributes to a further understanding of the impact of WaSH on A. lumbricoides infection and shows the importance of accounting for interactions between WaSH technologies and behaviors

325-MHz observations of the ELAIS-N1 field using the Giant Metrewave Radio Telescope

We present observations of the European Large-Area {\it ISO} Survey-North 1 (ELAIS-N1) at 325 MHz using the Giant Metrewave Radio Telescope (GMRT), with the ultimate objective of identifying active galactic nuclei and starburst galaxies and examining their evolution with cosmic epoch. After combining the data from two different days we have achieved a median rms noise of $\approx40 \mu$Jy beam$^{-1}$, which is the lowest that has been achieved at this frequency. We detect 1286 sources with a total flux density above $\approx270 \mu$Jy. In this paper, we use our deep radio image to examine the spectral indices of these sources by comparing our flux density estimates with those of Garn et al. at 610 MHz with the GMRT, and surveys with the Very Large Array at 1400 MHz. We attempt to identify very steep spectrum sources which are likely to be either relic sources or high-redshift objects as well as inverted-spectra objects which could be Giga-Hertz Peaked Spectrum objects. We present the source counts, and report the possibility of a flattening in the normalized differential counts at low flux densities which has so far been reported at higher radio frequencies.Comment: The paper contains 15 figures and 5 tables. Accepted for publication in MNRA

The impact of sanitation on infectious disease and nutritional status: A systematic review and meta-analysis.

BACKGROUND: Sanitation aims to sequester human feces and prevent exposure to fecal pathogens. More than 2.4 billion people worldwide lack access to improved sanitation facilities and almost one billion practice open defecation. We undertook systematic reviews and meta-analyses to compile the most recent evidence on the impact of sanitation on diarrhea, soil-transmitted helminth (STH) infections, trachoma, schistosomiasis, and nutritional status assessed using anthropometry. METHODS AND FINDINGS: We updated previously published reviews by following their search strategy and eligibility criteria. We searched from the previous review's end date to December 31, 2015. We conducted meta-analyses to estimate pooled measures of effect using random-effects models and conducted subgroup analyses to assess impact of different levels of sanitation services and to explore sources of heterogeneity. We assessed risk of bias and quality of the evidence from intervention studies using the Liverpool Quality Appraisal Tool (LQAT) and Grading of Recommendations, Assessment, Development, and Evaluation (GRADE) approach, respectively. A total of 171 studies met the review's inclusion criteria, including 64 studies not included in the previous reviews. Overall, the evidence suggests that sanitation is protective against diarrhea, active trachoma, some STH infections, schistosomiasis, and height-for-age, with no protective effect for other anthropometric outcomes. The evidence was generally of poor quality, heterogeneity was high, and GRADE scores ranged from very low to high. CONCLUSIONS: This review confirms positive impacts of sanitation on aspects of health. Evidence gaps remain and point to the need for research that rigorously describes sanitation implementation and type of sanitation interventions