Reduced-bias and partially reduced-bias mean-of-order-p value-at-risk estimation: a Monte-Carlo comparison and an application

On the basis of a sample of either independent, identically distributed or possibly weakly dependent and stationary random variables from an unknown model F with a heavy right-tail function, and for any small level q, the value-at-risk (VaR) at the level q, i.e. the size of the loss that occurs with a probability q, is estimated by new semi-parametric reduced-bias procedures based on the mean-of-order-p of a set of k quotients of upper order statistics, with p an adequate real number. After a brief reference to the asymptotic properties of these new VaR-estimators, we proceed to an overall comparison of alternative VaR-estimators, for finite samples, through large-scale Monte-Carlo simulation techniques. Possible algorithms for an adaptive VaR-estimation, an application to financial data and concluding remarks are also provided

Fatigue Effects in Daily Life Activities of Kidney Transplant Recipients

After undergoing kidney transplantation, some patients still face one symptom that continues after the dialysis sessions: fatigue (physical and mental tiredness that does not get better after resting). Fatigue effects in the everyday lives of kidney transplant patients can be beneficially modified early by changing this scenario. This is a quantitative study about the intensity and impacts of fatigue in kidney transplant patients admitted to the Hypertension and Kidney Hospital from October 2011 to March 2012. the fatigue pictogram was used to evaluate the level of fatigue interference in the daily life activities of kidney transplant patients. the sample consists of 39 patients, and was developed in 2 phases: data collection and attendance after and before the transplantation until hospital discharge. Descriptive statistical analyses were used. in the group at issue, we have noticed the following profile of the sample: 84.3% of transplantations with live donors, most were men, average age 36.5 years old, average hospitalization time 11.1 days, average time of renal failure 66.4 months, systemic arterial hypertension prevalence 66.7%, and the prevalence of at least 1.8 diseases in each individual. the self-referred causes of chronic renal failure were uncontrolled systemic arterial hypertension, glomerulonephritis, and overuse of anti-inflammatory drugs, among others. the study shows that fatigue is directly related to the level of activities of daily living, causing less ability to perform activities in the higher level of fatigue, which is in the immediate postoperative period and only settling fully on the 9th postoperative day.Universidade Federal de São Paulo, Nursing Sch São Paulo, São Paulo, BrazilUniversidade Federal de São Paulo, Kidney & Hypertens Hosp, São Paulo, BrazilUniversidade Federal de São Paulo, Nursing Sch São Paulo, São Paulo, BrazilUniversidade Federal de São Paulo, Kidney & Hypertens Hosp, São Paulo, BrazilWeb of Scienc

The Role of Black Rice (Oryza sativa L.) in the Control of Hypercholesterolemia in Rats

Cardiovascular disease is a serious public health problem; it is the first ""cause of death"" in Brazil and in developed countries. Thus, it is essential to search for alternative sources such as some functional foods to prevent and control the risks of this disease. The purpose of this study was to evaluate the lipidemic parameters in hypercholesterolemic rats fed diets containing black rice variety IAC 600 or unrefined rice. Adult male Wistar rats (Rattus norvegicus var. albinos) were used, weighing about 200-220 g. The animals were divided into four groups: the first received a control casein diet, the second received hypercholesterolemic diet, and the other two groups, after induction of hypercholesterolemia, received the test diets, the first containing 20% black rice and the second 20% unrefined, for 30 days. It was observed that diet containing black rice reduced the level of plasma cholesterol, triglycerides, and low-density lipoprotein. For high-density lipoprotein values, the diet that provided an increase in the levels was the black rice. The diet containing black rice was more effective in controlling the lipidemia in rats compared with the whole rice diet.1361355136

Dogs Have the Most Neurons, Though Not the Largest Brain: Trade-Off between Body Mass and Number of Neurons in the Cerebral Cortex of Large Carnivoran Species

Carnivorans are a diverse group of mammals that includes carnivorous, omnivorous and herbivorous, domesticated and wild species, with a large range of brain sizes. Carnivory is one of several factors expected to be cognitively demanding for carnivorans due to a requirement to outsmart larger prey. On the other hand, large carnivoran species have high hunting costs and unreliable feeding patterns, which, given the high metabolic cost of brain neurons, might put them at risk of metabolic constraints regarding how many brain neurons they can afford, especially in the cerebral cortex. For a given cortical size, do carnivoran species have more cortical neurons than the herbivorous species they prey upon? We find they do not; carnivorans (cat, mongoose, dog, hyena, lion) share with non-primates, including artiodactyls (the typical prey of large carnivorans), roughly the same relationship between cortical mass and number of neurons, which suggests that carnivorans are subject to the same evolutionary scaling rules as other non-primate clades. However, there are a few important exceptions. Carnivorans stand out in that the usual relationship between larger body, larger cortical mass and larger number of cortical neurons only applies to small and medium-sized species, and not beyond dogs: we find that the golden retriever dog has more cortical neurons than the striped hyena, African lion and even brown bear, even though the latter species have up to three times larger cortices than dogs. Remarkably, the brown bear cerebral cortex, the largest examined, only has as many neurons as the ten times smaller cat cerebral cortex, although it does have the expected ten times as many non-neuronal cells in the cerebral cortex compared to the cat. We also find that raccoons have dog-like numbers of neurons in their cat-sized brain, which makes them comparable to primates in neuronal density. Comparison of domestic and wild species suggests that the neuronal composition of carnivoran brains is not affected by domestication. Instead, large carnivorans appear to be particularly vulnerable to metabolic constraints that impose a trade-off between body size and number of cortical neurons

Influence of N-methyl-D-aspartate receptors on ouabain activation of nuclear factor-kappa B in the rat hippocampus

It has been shown that ouabain (OUA) can activate the Na,K-ATPase complex and mediate intracellular signaling in the central nervous system (CNS). Inflammatory stimulus increases glutamatergic transmission, especially at N-methyl-D-aspartate (NMDA) receptors, which are usually coupled to the activation of nitric oxide synthase (NOS). Nuclear factor-kappa B (NF-kappa B) activation modulates the expression of genes involved in development, plasticity, and inflammation. The present work investigated the effects of OUA on NF-kappa B binding activity in rat hippocampus and the influence of this OUA-Na,K-ATPase signaling cascade in NMDA-mediated NF-kappa B activation. The findings presented here are the first report indicating that intrahippocampal administration of OUA, in a concentration that did not alter Na,K-ATPase or NOS activity, induced an activation of NF-kappa B, leading to increases in brain-derived neurotrophic factor (Bdnf), inducible NOS (iNos), tumor necrosis factor-alpha (Tnf-alpha), and B-cell leukemia/lymphoma 2 (Bcl2) mRNA levels. This response was not linked to any significant signs of neurodegeneration as showed via Fluoro-Jade B and Nissl stain. Intrahippocampal administration of NMDA induced NF alpha B activation and increased NOS and alpha 2/3-Na,K-ATPase activities. NMDA treatment further increased OUA-induced NF-kappa B activation, which was partially blocked by MK-801, an antagonist of NMDA receptor. These results suggest that OUA-induced NF-kappa B activation is at least in part dependent on Na,K-ATPase modulatory action of NMDA receptor in hippocampus. The interaction of these signaling pathways could be associated with biological mechanisms that may underlie the basal homeostatic state linked to the inflammatory signaling cascade in the brain. (c) 2011 Wiley Periodicals, Inc.Fundacao de Amparo a Pesquisa do Estado de Sao Paulo-FAPESP [2003/08989-0]Fundacao de Amparo a Pesquisa do Estado de Sao Paulo (FAPESP)Conselho Nacional de Desenvolvimento Cientifico e Tecnologico-CNPq [485953-2007-2]Conselho Nacional de Desenvolvimento Cientifico e Tecnologico (CNPq)Universidade de Sao PauloUniversidade de Sao Paul