The thermodynamics of collapsing molecular cloud cores using smoothed particle hydrodynamics with radiative transfer

We present the results of a series of calculations studying the collapse of molecular cloud cores performed using a three-dimensional smoothed particle hydr odynamics code with radiative transfer in the flux-limited diffusion approximation. The opacities and specific heat capacities are identical for each calculation. However, we find that the temperature evolution during the simulations varies significantly when starting from different initial conditions. Even spherically-symmetric clouds with different initial densities show markedly different development. We conclude that simple barotropic equations of state like those used in some previous calculations provide at best a crude approximation to the thermal behaviour of the gas. Radiative transfer is necessary to obtain accurate temperatures.Comment: 8 pages, 9 figures, accepted for publication in MNRA

Identifying innovative and effective practice in e-assessment: findings from seventeen UK case studies

The aim of this JISC funded project was to extend the understanding of what e-assessment meant to users and producers in the HE and FE sectors. A case study methodology was employed to identify and report upon best and current practice within this field of inquiry. This approach facilitated the identification of both the enabling factors and barriers associated with e-assessment. The variety of applications of e-assessment studied and their innovation and general effectiveness indicate the potential of e-assessment to significantly enhance the learning environment and the outcomes for students, in a wide range of disciplines and applications

A simplified model of the Martian atmosphere - Part 2: a POD-Galerkin analysis

In Part I of this study Whitehouse et al. (2005) performed a diagnostic analysis of a simplied model of the Martian atmosphere, in which topography was absent and in which heating was modelled as Newtonian relaxation towards a zonally symmetric equilibrium temperature field. There we derived a reduced-order approximation to the vertical and the horizonal structure of the baroclinically unstable Martian atmosphere, retaining only the barotropic mode and the leading order baroclinic modes. Our objectives in Part II of the study are to incorporate these approximations into a Proper Orthogonal Decomposition-Galerkin expansion of the spherical quasi-geostrophic model in order to derive hierarchies of nonlinear ordinary differential equations for the time-varying coefficients of the spatial structures. Two different vertical truncations are considered, as well as three different norms and 3 different Galerkin truncations. We investigate each in turn, using tools from bifurcation theory, to determine which of the systems most closely resembles the data for which the original diagnostics were performed

Improving procedural fairness in housing possession cases

This article offers an insight into the context and practice of housing possession hearings in which a social landlord seeks a possession order against a tenant who is in rent arrears. Drawing on the findings of the authors’ empirical research, supplemented by insights from the psychology of decision-making, this article questions whether judges are able to exercise discretion in a manner consistent with the fundamental demands of ‘procedural fairness’. We find that while the legal process requires judges to engage in rational decision-making, and while judges believe that this is what they are doing, the reality is very different: judges are likely to be relying on intuition. It is not that judges eschew engaging in more deliberative decision-making but rather that they are constrained by limits of the human mind as well as the conditions under which they make their decisions. In particular, the practice of housing possession is characterised by information deficits, low levels of legal representation and time constraints, and this does not facilitate decision-making that meets accepted standards of fairness. In response, we propose ways in which to enhance the consistency, transparency and accountability of decision-making while recognising the current climate of reform and diminishing resources within the legal system

Effect of diet type on serum and faecal concentration of S100/calgranulins in the captive cheetah

Gastrointestinal disease is omnipresent in captive cheetahs (Acinonyx jubatus), in contrast to its freeranging populations. The current study aimed to evaluate the effect of diet type (meat-only whole prey) on gastrointestinal health in captive cheetahs by measuring faecal and serum concentrations of S100/calgranulins. This paper reports faecal S100A12 and calprotectin concentrations in 12 captive cheetahs fed supplemented beef versus whole rabbit for one month in a cross-over design. Also, serum S100A12 and calprotectin concentrations were determined in four cheetahs fed whole rabbit and six cheetahs fed supplemented beef, and these were compared to the faecal concentrations of the respective marker proteins. Both the immunoassay for canine calprotectin and canine S100A12 were precise and reproducible for use with serum samples and faecal extracts. Whereas the assay for S100A12 was linear and accurate, an inconsistent linearity of the canine calprotectin assay was observed and could be indicative of an insufficient cross-reactivity of the specific antibody used for this assay. Serum concentrations of S100A12 and calprotectin were not altered by diet type, and were not correlated with the respective concentrations in faeces. Numerically (P=0.241) greater calprotectin concentrations and greater (P=0.041) faecal S100A12 concentrations were detected in cheetahs fed supplemented beef compared with whole rabbit. These findings demonstrate that whole prey feeding may decrease intestinal inflammation in the captive cheetah. Consequently, the relation between diet type and intestinal inflammatory conditions in the captive cheetah warrants further investigation

Fermentation of animal components in strict carnivores: a comparative study with cheetah fecal inoculum

The natural diet of felids contains highly digestible animal tissues but also fractions resistant to small intestinal digestion, which enter the large intestine where they may be fermented by the resident microbial population. Little information exists on the microbial degradability of animal tissues in the large intestine of felids consuming a natural diet. This study aimed to rank animal substrates in their microbial degradability by means of an in vitro study using captive cheetahs fed a strict carnivorous diet as fecal donors. Fresh cheetah fecal samples were collected, pooled, and incubated with various raw animal substrates (chicken cartilage, collagen, glucosamine-chondroitin, glucosamine, rabbit bone, rabbit hair, and rabbit skin; 4 replicates per substrate) for cumulative gas production measurement in a batch culture technique. Negative (cellulose) and positive (casein and fructo-oligosaccharides; FOS) controls were incorporated in the study. Additionally, after 72 h of incubation, short-chain fatty acids (SCFA), including branched-chain fatty acids (BCFA), and ammonia concentrations were determined for each substrate. Glucosamine and glucosamine-chondroitin yielded the greatest OM cumulative gas volume (OMCV) among animal substrates (P < 0.05), whereas total SCFA production was greatest for collagen (P < 0.05). Collagen induced an acetate production comparable to FOS and a markedly high acetate-to-propionate ratio (8.41:1) compared to all other substrates (1.67:1 to 2.97:1)

Roughness Signature of Tribological Contact Calculated by a New Method of Peaks Curvature Radius Estimation on Fractal Surfaces

This paper proposes a new method of roughness peaks curvature radii calculation and its application to tribological contact analysis as characteristic signature of tribological contact. This method is introduced via the classical approach of the calculation of radius of asperity. In fact, the proposed approach provides a generalization to fractal profiles of the Nowicki's method [Nowicki B. Wear Vol.102, p.161-176, 1985] by introducing a fractal concept of curvature radii of surfaces, depending on the observation scale and also numerically depending on horizontal lines intercepted by the studied profile. It is then established the increasing of the dispersion of the measures of that lines with that of the corresponding radii and the dependence of calculated radii on the fractal dimension of the studied curve. Consequently, the notion of peak is mathematically reformulated. The efficiency of the proposed method was tested via simulations of fractal curves such as those described by Brownian motions. A new fractal function allowing the modelling of a large number of physical phenomena was also introduced, and one of the great applications developed in this paper consists in detecting the scale on which the measurement system introduces a smoothing artifact on the data measurement. New methodology is applied to analysis of tribological contact in metal forming process

Loudly sing cuckoo : More-than-human seasonalities in Britain

This research was funded by a grant from the Arts and Humanities Research Council, grant number AH/E009573/1.Peer reviewedPostprin