Clustering around radio galaxies at z~1.5

The importance of studying old elliptical galaxies at redshift z ~ 1.5 is reviewed, considering both what can be learned by extending studies of the evolution of cluster galaxy scaling relations to earlier cosmic epochs, and the age-dating of old elliptical galaxies at high redshifts. Following this, the first results are provided of an on-going project to find such distant elliptical galaxies, through an investigation of the cluster environments of powerful radio sources with redshifts 1.44 < z < 1.7. These studies show a considerable excess of red galaxies in the radio sources fields, with the magnitudes (K >~ 17.5) and colours (R-K > 4) expected of old passively evolving galaxies at the radio source redshift. The red galaxy overdensities are found on two different scales around the radio sources; a pronounced small-scale peak at radial distances of <~ 150 kpc, and a weaker large-scale excess extending out to 1 - 1.5 Mpc. The presence and richness of these red galaxy excesses varies considerably from source to source. An interpretation of these results is provided.Comment: LaTeX, 6 pages, Elsevier Science format. To appear in "Radio galaxies: past, present & future". eds. M. Jarvis et al., Leiden, Nov 200

Increased baseline body weight is a risk factor associated with virological failure while on antiretroviral treatment

Mexico AIDS Conference 200

The final two redshifts for radio sources from the equatorial BRL sample

Best, Rottgering and Lehnert (1999, 2000a) defined a new sample of powerful radio sources from the Molonglo Reference Catalogue, for which redshifts were compiled or measured for 177 of the 178 objects. For the final object, MRC1059-010 (3C249), the host galaxy is here identified using near-infrared imaging, and the redshift is determined from VLT spectroscopy. For one other object in the sample, MRC0320+053 (4C05.14), the literature redshift has been questioned: new spectroscopic observations of this object are presented, deriving a corrected redshift. With these two results, the spectroscopic completeness of this sample is now 100%. New redshifts are also presented for PKS0742+10 from the Wall & Peacock 2.7 GHz catalogue, and PKS1336+003 from the Parkes Selected Regions. PKS0742+10 shows a strong neutral hydrogen absorption feature in its Lyman-alpha emission profile.Comment: 4 pages. LaTeX. Accepted for publication in MNRA

How the mass media report social statistics: A case study concerning research on end-of-life decisions

This is the post-print version of the final paper published in Social Science & Medicine. The published article is available from the link below. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting, and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. Copyright @ 2010 Elsevier B.V.The issue of whether it is right to be concerned about the accuracy with which mass media report social scientific research is explored through a detailed case study of media reporting of two surveys of UK doctors' end-of-life decision-making. Data include press releases, emails and field notes taken during periods of media interest supplemented by a collection of print and broadcast media reports. The case study contributes to existing knowledge about the ways in which mass media establish, exaggerate and otherwise distort the meaning of statistical findings. Journalists ignored findings that did not fit into existing media interest in the 'assisted dying' story and were subject to pressure from interest groups concerned to promote their own interpretations and viewpoints. Rogue statistics mutated as they were set loose from their original research report context and were 'laundered' as they passed from one media report to another. Yet media accounts of the research, fuelling an already heated public debate about ethical issues in end-of-life care, arguably acted as a conduit for introducing new considerations into this debate, such as the role played by sedation at the end of life, the extent to which euthanasia is practiced outside the law, and the extent of medical opposition to the legalisation of assisted dying. The expectation that accuracy and comprehensiveness should be the sole criteria for judging journalists' reports is, finally, considered to be unrealistic and it is argued that social scientists need to understand and adapted to the conditions under which mass media reporting operates if they are to succeed in introducing the findings of social research into public debates.The Nuffield Foundation, the National Council for Palliative Care, Age Concern, the Motor Neurone Disease Association, the Multiple Sclerosis Society, Help the Hospices, Macmillan Cancer Support, and Sue Ryder Care

Infrared Magnitude-Redshift Relations for Luminous Radio Galaxies

Infrared magnitude-redshift relations for the 3CR and 6C samples of radio galaxies are presented for a wide range of plausible cosmological models, including those with non-zero cosmological constant OmegaLambda. Variations in the galaxy formation redshift, metallicity and star formation history are also considered. The results of the modelling are displayed in terms of magnitude differences between the models and no-evolution tracks, illustrating the amount of K-band evolution necessary to account for the observational data. Given a number of plausible assumptions, the results of these analyses suggest that: (i) cosmologies which predict T_0xH_0>1 (where T_0 denotes the current age of the universe) can be excluded; (ii) the star formation redshift should lie in the redshift interval 5<z<20, values towards the lower end of the range being preferred in cosmologies with larger values of T_0xH_0; (iii) the Einstein-de Sitter model provides a reasonable fit to the data; (iv) models with finite values of OmegaLambda can provide good agreement with the observations only if appropriate adjustments of other parameters such as the galaxy metallicities and star-formation histories are made. Without such modifications, even after accounting for stellar evolution, the high redshift radio galaxies are more luminous (ie. more massive) than those nearby in models with finite OmegaLambda, including the favoured model with Omega=0.3, OmegaLambda=0.7. For cosmological models with larger values of T_0xH_0, the conclusions are the same regardless of whether any adjustments are made or not. The implications of these results for cosmology and models of galaxy formation are discussed.Comment: 14 pages, LaTeX, 9 figures, accepted for publication in MNRAS. Replacement corrects some annoying typo

HST and UKIRT imaging observations of z~1 6C radio galaxies - II. Galaxy morphologies and the alignment effect

(abridged) Powerful radio galaxies often display enhanced optical/UV emission regions, elongated and aligned with the radio jet axis. The aim of this series of papers is to separately investigate the effects of radio power and redshift on the alignment effect, together with other radio galaxy properties. In this second paper, we present a deeper analysis of the morphological properties of these systems, including both the host galaxies and their surrounding aligned emission. The host galaxies of our 6C subsample are well described as de Vaucouleurs ellipticals, with typical scale sizes of ~10kpc. This is comparable to the host galaxies of low-z radio sources of similar powers, and also the more powerful 3CR sources at the same redshift. The contribution of nuclear point source emission is also comparable, regardless of radio power. The 6C alignment effect is remarkably similar to that seen around more powerful 3CR sources at the same redshift in terms of extent and degree of alignment with the radio source axis, although it is generally less luminous. The bright, knotty features observed in the case of the z~1 3CR sources are far less frequent in our 6C subsample; neither do we observe such strong evidence for evolution in the strength of the alignment effect with radio source size/age. However, we do find a very strong link between the most extreme alignment effects and emission line region properties indicative of shocks, regardless of source size/age or power. In general, the 6C alignment effect is still considerably stronger than that seen around lower redshift galaxies of similar radio powers. (abridged)Comment: 23 pages, 15 figures, accepted for publication in MNRAS. See http://www.mrao.cam.ac.uk/~kji/MorphPaper/ for version of paper with full resolution images of Figs 1-1

Bold colouration pattern in southern bottlenose whales, a preliminary assessment of external variation. Scientific Committee document SC/57/SM12, International Whaling Commission, May-June 2005, Ulsan, Korea

Insights in the variation in pigmentation patterns and other external features in Hyperoodon planifrons are few, in particular, variability contributed by each of individual, ontogenetic, sexual, and geographic factors. A preliminary assessment is based on two close-up sightings of juveniles during IWC-SOWER Cruises and stranded specimens from South Africa, Australia and New Zealand. Bold, cream-white facial fields separated by a distinct dark blowhole stripe are diagnostic of all juvenile/neonates examined and may persist in subadults. Dark eyepatches may be pronounced or almost absent, a light nuchal band behind the blowhole may be prominent or muted, and the dorsal aspect of flippers may be light or dark. A light flank patch on the tailstock is consistent in juveniles. With maturation the head pattern gradually blurs, apparently because facial fields and the nuchal band gain pigmentation. The slate-grey or dark brownish-grey spinal field in juveniles is appreciably darker than in most adults, in which it varies widely, ranging from brownish-grey (most common), bluish-black to yellowish. Diatoms have been blamed as cause for the brown hue, however the evidence is unclear. Large, almost-white animals have been reported but no such specimens were available for study. Much of the external variation seen may be individual and ontogenetic, however sexual dimorphism and geographic variation remain unassessed due to small samples. A comprehensive morphological study is indicated. The bold features in juvenile H. planifrons are diagnostically distinct from juvenile Tasmacetus shepherdi and Indopacetus pacificus. Non-priority status and long dive durations have allowed scant time for data collection on H. planifrons during Antarctic surveys. This study shows that maximizing opportunistic encounters through allowance for some flexibility in schedules, valuable data can be obtained. A rule-of-thumb is recommended for avoiding ziphiid species identification at distances exceeding 0.8 nmiles

Advances in hepatic stem/progenitor cell biology

The liver is famous for its strong regenerative capacity, employing different modes of regeneration according to type and extent of injury. Mature liver cells are able to proliferate in order to replace the damaged tissue allowing the recovery of the parenchymal function. In more severe scenarios hepatocytes are believed to arise also from a facultative liver progenitor cell compartment. In human, severe acute liver failure and liver cirrhosis are also both important clinical targets in which regeneration is impaired, where the role of this stem cell compartment seems more convincing. In animal models, the current state of ambiguity regarding the identity and role of liver progenitor cells in liver physiology dampens the enthusiasm for the potential use of these cells in regenerative medicine. The aim of this review is to give the basics of liver progenitor cell biology and discuss recent results vis-à-vis their identity and contribution to liver regeneration

A LOFAR view on the duty cycle of young radio sources

Compact Steep Spectrum, Gigahertz Peaked Spectrum and High Frequency Peak (CSS, GPS, HFP) sources are considered to be young radio sources but the details of their duty cycle are not well understood. In some cases they are thought to develop in large radio galaxies, while in other cases their jets may experience intermittent activity or die prematurely and remain confined within the host galaxy. By studying in a systematic way the presence and the properties of any extended emission surrounding these compact sources we can provide firmer constraints on their evolutionary history and on the timescales of activity of the radio source. Remnant emission from previous outbursts is supposed to have very low surface brightness and to be brighter at low frequency. Taking advantage of the unprecedented sensitivity and resolution provided by the Low Frequency Array (LOFAR) we have started a systematic search of new CSS, GPS and HFP sources with extended emission, as well as a more detailed study of some well-known of these sources. Here we present the key points of our search in the LOFAR fields and a more in-depth analysis on the source B2 0258+35, a CSS source surrounded by a pair of large, diffuse radio lobes.Comment: 5 pages, 2 figures, in press for Astronomische Nachrichten. Contribution to the Proceedings of the "Fifth Workshop on Compact Steep Spectrum and GHz-Peaked Spectrum Radio Sources", held in Rimini (Italy) in May 201