Numerical Simulation and Optimisation of a Gas-Solid-Liquid Separator

Imperial Users onl

Self-Assessed Health Status and Satisfaction with Health Care Services in the Context of the Enlarged European Union

The paper aims at analysing the relationship between self-rated health-status, satisfaction with health care services and socio-economic factors, in the context of different national health care systems in the enlarged European Union. The effects of socio-economic deprivation and the functioning of national health care systems on self-rated health status and satisfaction with health care services are investigated using the European Social Survey 2006 dataset (ESS3), and macro data provided by Eurostat (2007) and the World Health Organization (2007). Socio-economic deprivation is measured both at the micro-level (using indicators of economic strain, household income, education, employment status and belonging to discriminated groups), and the macro-level (national poverty rates, the values of poverty thresholds, quintile ratios and GDP per capita). The performance of national health care systems is quantified with the help of two indexes, designed for the purpose of the present study: an index of total health care provisions and an index of governmental commitment to health care. The following countries are included in the analysis: Belgium, Bulgaria, Denmark, Finland, France, Germany, Hungary, Poland, Portugal, Romania, Slovenia, Slovakia, Spain, Sweden, and the United Kingdom.self-assessed health ; health care systems ; health inequalities ; governmental policies

An economic approach to collective management of endemic animal diseases

The control of animal diseases is an issue of particular interest in animal production chains. Because of their direct impact on production, animal diseases generate income shortfalls for farmers. In some cases, diseases may also have lead to human health problems and undermine market access conditions. Because of these potential negative impacts, some diseases are regulated. But for many communicable diseases, much latitude is given to individual control of the disease by farmers. In the case of a communicable disease, individual management therefore generates an externality, as individual decisions have an impact on the level of risk exposure of other farms to the disease. Thus, the collective result of individual management may differ from the collective expectations. This gap can be reduced by collective actions. The aim of this paper is to provide a conceptual framework for the study of collective management of animal diseases, which will provide management tools to collective managers of animal health. The development of this conceptual framework rests on three steps. We first discuss the means to model the individual decisions of farmer in regard to animal diseases. Then it should take into account the interaction between the epidemiology of the disease and the individual decisions of farmers, by the coupling of epidemiologic and economic models. Finally, collective management tools are introduced in these models in order to test incentives schemes for horizontal coordination. Finally, collective actions are introduced in these models, in order to test devices for horizontal coordination (management of prevalence between farms).Animal health economics - Micro modelling – Bio-economic modelling - endemic animal diseases, Animal health economics, Micro modelling, Bio-economic modelling, endemic animal diseases, Livestock Production/Industries,

The role of CA1 α-adrenoceptor on scopolamine induced memory impairment in male rats

Introduction: Similarities in the memory impairment between Alzheimer patients and scopolamine treated animals have been reported. In the present study, the possible role of α-adrenergic receptors of the dorsal hippocampus on scopolamine state-dependent memory in adult male Wistar rats was evaluated. Methods: The animals were bilaterally implanted with chronic cannulae in the CA1 regions of the dorsal hippocampus, trained in a step-through type inhibitory avoidance task, and tested 24 h after training to measure step-through latency. Results: Post-training intra-CA1 administration of scopolamine (0.5 and 2μg/rat) dose-dependently reduced the step-through latency, showing an amnestic response. Amnesia produced by post-training scopolamine (2 μg/rat) was reversed by pre-test administration of the scopolamine (0.5 and 2 μg/rat) that is due to a state-dependent effect. Pre-test intra-CA1 injection of α1-adrenoceptor agonist, phenylephrine (0.25, 0.5 μg/rat) in the dose range that we used, could not affect memory impairment induced by post-training injection of scopolamine (2 μg/rat). However intra-CA1 pretest injection of α2-adrenoceptor agonist, clonidine (0.5 μg/rat) improved post-training scopolamine (2 μg/rat) intra-CA1 injection induced retrieval impairment. Furthermore, pre-test intra-CA1 microinjection of phenylephrine (0.25 and 0.5 μg/rat) or clonidine (0.25 and 0.5 μg/rat) with an ineffective dose of scopolamine (0.25 μg/rat), synergistically improved memory performance impaired by post-training scopolamine (2 μg/rat). Our results also showed that, pre-test injection of α1-receptor antagonist prazosin (1, 2 μg/rat) or α2-receptors antagonist yohimbine (1, 2 μg/rat) before effective dose of scopolamine (2 μg/rat) prevented the improvement of memory by pre-test scopolamine. Conclusion: These results suggest that α1- and α2-adrenergic receptors of the dorsal hippocampal CA1 region may play an important role in scopolamine-induced amnesia and scopolamine state-dependent memory

Solving the "Isomorphism of Polynomials with Two Secrets" Problem for all Pairs of Quadratic Forms

We study the Isomorphism of Polynomial (IP2S) problem with m=2 homogeneous quadratic polynomials of n variables over a finite field of odd characteristic: given two quadratic polynomials (a, b) on n variables, we find two bijective linear maps (s,t) such that b=t . a . s. We give an algorithm computing s and t in time complexity O~(n^4) for all instances, and O~(n^3) in a dominant set of instances. The IP2S problem was introduced in cryptography by Patarin back in 1996. The special case of this problem when t is the identity is called the isomorphism with one secret (IP1S) problem. Generic algebraic equation solvers (for example using Gr\"obner bases) solve quite well random instances of the IP1S problem. For the particular cyclic instances of IP1S, a cubic-time algorithm was later given and explained in terms of pencils of quadratic forms over all finite fields; in particular, the cyclic IP1S problem in odd characteristic reduces to the computation of the square root of a matrix. We give here an algorithm solving all cases of the IP1S problem in odd characteristic using two new tools, the Kronecker form for a singular quadratic pencil, and the reduction of bilinear forms over a non-commutative algebra. Finally, we show that the second secret in the IP2S problem may be recovered in cubic time

The endogenous production of hydrogen sulphide in intrauterine tissues

Background: Hydrogen sulphide is a gas signalling molecule which is produced endogenously from L-cysteine via the enzymes cystathionine beta-synthase (CBS) and cystathionine gamma-lyase (CSE). The possible role of hydrogen sulphide in reproduction has not yet been fully investigated. It has been previously demonstrated that hydrogen sulphide relaxes uterine smooth muscle in vitro. The aim of the present study was to investigate the endogenous production of hydrogen sulphide in rat and human intrauterine tissues in vitro. Methods: The production of hydrogen sulphide in rat and human intrauterine tissues was measured in vitro using a standard technique. The expression of CBS and CSE was also investigated in rat and human intrauterine tissues via Western blotting. Furthermore, the effects of nitric oxide (NO) and low oxygen conditions on the production rates of hydrogen sulphide were investigated. Results: The order of hydrogen sulphide production rates (mean +/- SD, n = 4) for rat tissues were: liver (777 +/- 163 nM/min/g) > uterus (168 +/- 100 nM/min/g) > fetal membranes (22.3 +/- 15.0 nM/min/g) > placenta (11.1 +/- 4.7 nM/min/g), compared to human placenta (200 +/- 102 nM/ min/g). NO significantly increased hydrogen sulphide production in rat fetal membranes (P < 0.05). Under low oxygen conditions the production of hydrogen sulphide was significantly elevated in human placenta, rat liver, uterus and fetal membranes (P < 0.05). Western blotting (n = 4) detected the expression of CBS and CSE in all rat intrauterine tissues, and in human placenta, myometrium, amnion and chorion. Conclusion: Rat and human intrauterine tissues produce hydrogen sulphide in vitro possibly via CBS and CSE enzymes. NO increased the production of hydrogen sulphide in rat fetal membranes. The augmentation of hydrogen sulphide production in human intrauterine tissues in a low oxygen environment could have a role in pathophysiology of pregnancy

Controlling composition factors of a finite group by its character degree ratio

For a finite nonabelian group $G$ let \rat(G) be the largest ratio of degrees of two nonlinear irreducible characters of $G$. We show that nonabelian composition factors of $G$ are controlled by \rat(G) in some sense. Specifically, if $S$ different from the simple linear groups \PSL_2(q) is a nonabelian composition factor of $G$, then the order of $S$ and the number of composition factors of $G$ isomorphic to $S$ are both bounded in terms of \rat(G). Furthermore, when the groups \PSL_2(q) are not composition factors of $G$, we prove that |G:\Oinfty(G)|\leq \rat(G)^{21} where \Oinfty(G) denotes the solvable radical of $G$.Comment: 16 pages, 1 tabl