A pressure based method for the solution of viscous incompressible turbomachinery flows

A new technique was developed for the solution of the incompressible Navier-Stokes equations. The numerical technique, derived from a pressure substitution method (PSM), overcomes many of the deficiencies of the pressure correction method. This technique allows for the direct solution of the actual pressure in the form of a Poisson equation which is derived from the pressure weighted substitution of the full momentum equations into the continuity equation. Two dimensional internal flows are computed with this method. The prediction of cascade performance is presented. The extention of the pressure correction method for the solution of three dimensional flows is also presented

Root to Kellerer

We revisit Kellerer's Theorem, that is, we show that for a family of real probability distributions $(\mu_t)_{t\in [0,1]}$ which increases in convex order there exists a Markov martingale $(S_t)_{t\in[0,1]}$ s.t.\ $S_t\sim \mu_t$. To establish the result, we observe that the set of martingale measures with given marginals carries a natural compact Polish topology. Based on a particular property of the martingale coupling associated to Root's embedding this allows for a relatively concise proof of Kellerer's theorem. We emphasize that many of our arguments are borrowed from Kellerer \cite{Ke72}, Lowther \cite{Lo07}, and Hirsch-Roynette-Profeta-Yor \cite{HiPr11,HiRo12}.Comment: 8 pages, 1 figur

Endothelial proliferation in tumours and normal tissues: continuous labelling studies.

The proliferation rate of vascular endothelium has been studied using repeated administrations of tritiated thymidine, given every 8 h for 1 week. Five experimental mouse tumours have been investigated and compared with placenta and with normal tissues. The large difference in labelling indices between tumour and normal endothelium that has previously been detected with single injections of ([3H]dT) is confirmed by these continuous labelling studies. The potential doubling time of the tumour endothelium is estimated to be between 2.4 and 13 days for the five tumours. Tpot for the placenta is at least as short. The turnover time of the normal tissue endothelium is estimated to be 20-2000 times longer (47-23,000 days) and does not seem to differ in slow turnover tissues e.g. lung and liver from that in tissues where the parenchymal cells are rapidly turning over e.g. jejunum or skin

Changes in nerve conduction velocity in the mouse after acute and chronic administration of nitroimidazoles.

The effect of the nitroimidazoles misonidazole, Ro-05-9963, RGW-608 and metronidazole on nerve conduction velocity (NCV) were measured in the anaesthetized mouse. The compounds were administered by i.p. injection either as a single dose of 1 mg/g (only 0.5 mg/g for RGW-608) or in 36 fractions of 0.15 mg/g over 18 days (only 4 fractions in 2 days for RGW-608). After single doses a reduction in nerve conduction velocity was seen with all the compounds except metronidazole, which had no significant effect. During chronic exposure, a reduction in NCV occurred towards the end of the course of injections. All compounds produced an effect, although RGW-608 was the most neurotoxic, giving the largest reduction in NCV after only 4 injections. After the end of chronic exposure to misonidazole, Ro-05-9963 and metronidazole, recovery to normal took 2-3 weeks

Origins of Late-Breeding Nomadic Sedge Wrens in North America: Limitations and Potential of Hydrogen-Isotope Analyses of Soft Tissue

This is the published version. Copyright Central Ornithology Publication OfficeThe nomadic Sedge Wren (Cistothorus platensis) breeds primarily in mesic grasslands in north-central North America. Following breeding in these regions from late May to early July, however, the species then “appears” en masse in the tallgrass prairie region farther south (e.g., Missouri and Kansas) and to the east to breed again from mid-July to early August (Herkert et al. 2001). The provenance of birds appearing in late summer to breed in these areas remains unknown because of problems inherent in mark—recapture surveys. Recent studies have shown how endogenous markers may be used to infer origins of individual birds. We analyzed levels of the stable hydrogen isotope 2H (δD) from liver, muscle, and claws of Sedge Wrens from known northern breeding locations first to establish the relationships between δD in the wrens' tissue and mean δD in precipitation during the growing season (δDp ). From these relationships we derived expected values (mean and 95% CI) for three sites in Kansas and Missouri where late breeders colonized. The observed values of δD in these late breeders were primarily within the range expected for those locations, but more individuals than expected had δD values higher than expected. In addition, in birds apparently originating from north or south of Kansas and Missouri, the values of δD in claws were positively correlated with those in other tissues, in contrast to those with the “local” signal. This supports the idea that the isotopic outliers at these sites were more recent arrivals. For small-bodied birds like the Sedge Wren, however, the isotopic approach based on soft tissues is limited to a very narrow temporal window of inference because of rapid elemental turnover. This greatly restricts the use of this technique in inferring origins of small nomadic species

Fear Appeals in Anti-Knife Carrying Campaigns: Successful or Counter-Productive?

In the UK, knife crime continues to be a persistent and worrying concern. Media campaigns are often used by police and anti-knife crime organisations in an attempt to discourage young people from picking up a weapon. Many focus on the potentially devastating consequences associated with carrying a weapon, with the aim of provoking fear and thus a deterrent effect. In this paper we present the findings from two experimental studies exploring the effects of exposure to fear-based knife crime media campaigns on young people’s intentions to engage in knife carrying behaviour. Utilising a terror management theory perspective, in both studies we found that exposure to knife-related campaign imagery increased mortality salience, but there was no effect of campaign condition on willingness to carry a knife or on perceived benefits of knife-carrying. Although knife-related self-esteem/cultural world views predicted attitudes towards knife-carrying, such views did not moderate the effect of exposure to knife-related campaign imagery, and there was no effect of priming participants’ to consider the value of behaving responsibly. Implications and suggestions for future research are discussed

Bayes-X: a Bayesian inference tool for the analysis of X-ray observations of galaxy clusters

We present the first public release of our Bayesian inference tool, Bayes-X, for the analysis of X-ray observations of galaxy clusters. We illustrate the use of Bayes-X by analysing a set of four simulated clusters at z=0.2-0.9 as they would be observed by a Chandra-like X-ray observatory. In both the simulations and the analysis pipeline we assume that the dark matter density follows a spherically-symmetric Navarro, Frenk and White (NFW) profile and that the gas pressure is described by a generalised NFW (GNFW) profile. We then perform four sets of analyses. By numerically exploring the joint probability distribution of the cluster parameters given simulated Chandra-like data, we show that the model and analysis technique can robustly return the simulated cluster input quantities, constrain the cluster physical parameters and reveal the degeneracies among the model parameters and cluster physical parameters. We then analyse Chandra data on the nearby cluster, A262, and derive the cluster physical profiles. To illustrate the performance of the Bayesian model selection, we also carried out analyses assuming an Einasto profile for the matter density and calculated the Bayes factor. The results of the model selection analyses for the simulated data favour the NFW model as expected. However, we find that the Einasto profile is preferred in the analysis of A262. The Bayes-X software, which is implemented in Fortran 90, is available at http://www.mrao.cam.ac.uk/facilities/software/bayesx/.Comment: 22 pages, 11 figure