XMM-Newton Surveys of the Canada-France Redshift Survey Fields - III: The Environments of X-ray Selected AGN at 0.4<z<0.6

The environmental properties of a sample of 31 hard X-ray selected AGN are investigated, from scales of 500 kpc down to 30 kpc, and are compared to a control sample of inactive galaxies. The AGN all lie in the redshift range 0.4<z<0.6. The accretion luminosity-density of the Universe peaks close to this redshift range, and the AGN in the sample have X-ray luminosities close to the knee in the hard X-ray luminosity function, making them representative of the population which dominated this important phase of energy conversion. Using both the spatial clustering amplitude and near neighbour counts it is found that the AGN have environments that are indistinguishable from normal, inactive galaxies over the same redshift range and with similar optical properties. Typically, the environments are of sub-cluster richness, in contrast to similar studies of high-z quasars, which are often found in clusters with comparable richness to the Abell R>=0 clusters. It is suggested that minor mergers with low mass companions is a likely candidate for the mechanism by which these modest luminosity AGN are fuelled.Comment: 12 pages, 6 figures, accepted by MNRA

Evidence of increased UV Fe II emission in quasars in candidate overdense regions

We present evidence for a skewed distribution of UV Fe ii emission in quasars within candidate overdense regions spanning spatial scales of ∼50 Mpc at 1.11 42 Å) and a dearth of low-equivalent-width sources. There are various possible explanations for this effect, including dust, Lyα fluorescence, microturbulence and iron abundance. We find that the most plausible of these is enhanced iron abundance in the overdense regions, consistent with an enhanced star formation rate in the overdense regions compared to the field

A 3D Voronoi+Gapper Galaxy Cluster Finder in Redshift Space to z

This paper is the first in a series, presenting a new galaxy cluster finder based on a three-dimensional Voronoi Tesselation plus a maximum likelihood estimator, followed by gapping-filtering in radial velocity(VoML+G). The scientific aim of the series is a reassessment of the diversity of optical clusters in the local universe. A mock galaxy database mimicking the southern strip of the magnitude(blue)-limited 2dF Galaxy Redshift Survey (2dFGRS), for the redshift range 0.009 N g ≥ 5, and 14% with N g < 5. The ensemble of VoML+G clusters has a ~59% completeness and a ~66% purity, whereas the subsample with N g ≥ 10, to z ~ 0.14, has greatly improved mean rates of ~75% and ~90%, respectively. The VoML+G cluster velocity dispersions are found to be compatible with those corresponding to "Millennium clusters" over the 300–1000 km s−1 interval, i.e., for cluster halo masses in excess of ~3.0 × 1013 M ⊙ h −1

The effect of load and viscosity on the minimum operating oil film thickness of piston-rings in internal combustion engines

Computer simulations are now routinely used in the design and analysis of ring packs for internal combustion engines. Commonly they predict that an increase in engine load decreases minimum operating film thickness because oil availability and oil transport through the ring pack are reduced under these conditions. To assess the reliability of new simulations, investigators compare the output of computer models with experimental measurements of parameters on operating engines. Contributing to this process this paper presents an experimental study of an investigation into the effect of load on the minimum oil film thickness between piston rings and cylinder liner in a fired compression ignition engine. Oil film thickness data were collected using capacitance-based transducers located near top dead centre and mid-stroke. Experiments were performed at 2000 r/min using two mono-grade oils (SAE 50 and SAE 20) and one multi-grade oil (SAE 5W50) under a range of fixed engine loads. The experimental data obtained are discussed in the context of experimental and theoretical work published by other investigators

New species of Xanthoria (Teloschistaceae) from Southern Africa.

Abstract is not availabl

The relation between outcome expectation, therapeutic alliance, and outcome among depressed patients in group cognitive-behavioral therapy

OBJECTIVE: Although patients' expectation for improvement correlates with their treatment outcome, there remains limited information regarding the mechanisms through which outcome expectation influences outcome. Although several studies have revealed alliance as a mediator of the expectancy-outcome relation, most have focused on individual psychotherapy only. More research is needed examining mediators, including alliance quality, of the outcome expectation-outcome relation in group therapy. METHOD: This study focused on such associative chains among 91 depressed outpatients who completed 10 weeks of group cognitive-behavioral therapy. We conducted simple and multiple mediation analyses, accounting for the nested data structure. RESULTS: As predicted, we found: (i) The relations between baseline outcome expectation and both posttreatment anxiety and depression were mediated by alliance quality; (ii) the early therapy outcome expectation-posttreatment anxiety relation was mediated by mid-treatment alliance; (iii) the relation between early alliance and posttreatment interpersonal problems was mediated by during-therapy outcome expectation; and (iv) the relation between baseline outcome expectation and posttreatment interpersonal problems was mediated by two variables acting in turn, early alliance and during-therapy outcome expectation. All other tested models were not significant. CONCLUSIONS: Results suggest that bidirectional relations between outcome expectation and alliance, with both directions influencing outcome. Clinical and empirical implications are discussed