The effect of compensating faults models on NMR system reliability

Realistic estimates of the reliability of systems with N-tuple modular redundancy (NMR), must consider the effect of compensation of logic faults. Earlier analyses that include compensating faults are impractical to use, yield very complex mathematical formulas for reliability indices, and/or concern the simplest triple modular redundancy (TMR) system only. This paper gives a general approach to the problem. Two models of compensating faults are considered. For either model the lower and upper bounds on frequency of compensating faults are found. By applying some results of NMR system evaluation, the new estimates of upper and lower bounds of NMR system reliability with respect to compensating faults are derived. A simple algebraic form of the final results makes them useful     

All that you can be: stereotyping of self and others in a military context

The authors tested the shifting standards model (M. Biernat, M. Manis, & T. E. Nelson, 1991) as it applies to sex- and race-based stereotyping of self and others in the military. U. S. Army officers attending a leadership training course made judgments of their own and their groupmates' leadership competence at 3 time points over a 9-week period. We examined the effects of officer sex and race on both subjective (rating) and objective/common-rule (ranking/Q-sort) evaluations. Stereotyping generally increased with time, and in accordance with the shifting standards model, pro-male judgment bias was more evident in rankings than in ratings, particularly for White targets. Self-judgments were also affected by sex-based shifting standards, particularly in workgroups containing a single ("solo") woman. Differential standard use on the basis of race was less apparent, a finding attributed to the Army's explicit invocation against the use of differential race-based standards.     

Effect of high-fat cholesterol enriched diets on hypolipemic action of Oenothera paradoxa oil in rats. Part 1. Blood serum and liver lipids

The effect on Oenothera paradoxa oil on blood serum and liver lipids metabolism in rats fed a semisynthetic high-fat cholesterol enriched diets was investigated. The source of fats was sunflower oil or lard in 15% quantities and the source of protein was soybean protein isolate in 27% quantity. The diets were enriched with 0.5% cholesterol. This dietary experiment was carried on for 8 weeks. For the first 4 weeks rats were fed standard diet and for the next 4 weeks Oe. paradoxa oil (300 mg/day/rat) was additionally given by stomach-tube. At the end of experiment the contents of total cholesterol, HDL-cholesterol, triglycerides and free fatty acids in blood serum as well as cholesterol and triglycerides level in liver were determined. It was found, that the addition of cholesterol to the diet decreased the hypocholesterolemic and hypotriglyceridemic effects of Oe. paradoxa oil both in blood serum and liver. It have not had any significant effect on the free fatty acid concentration in blood serum decrease by Oe. paradoxa oil intake.     

Nitric oxide as mediator of bradykinin-induced pancreatic circulatory and metabolic responses

Bradykinin (BK) is an endogenous nonapeptide with potent vasodilator properties of the visceral circulation. BK alters vascular tone via two BK receptor subtypes, B1 and B2. Current experimental evidence suggests that the dilator action of BK in some vessels is mediated primarily by B2 receptor activation. In addition, there are reports that BK increases endothelial generation of vasodilator factors, such as nitric oxide (NO). The present study had two aims. First, to explore the role of BK-receptors in the pancreatic vasodilatatory and metabolic responses to BK. Second aim was to examine whether endogenous NO play a role in the mediation of BK-receptors induced pancreatic circulatory and metabolic activity. In anesthetized dogs, the superior pancreatico-duodenal artery blood flow (SPBF) was measured by ultrasonic blood flowmeter (Transonic System T-206), pancreatic microcirculatory blood flow (PBF) was determined by laser Doppler flowmetry (Periflux 4001 Master). Pancreatic oxygen consumption (PVO2) was calculated as the product of the arteriovenous oxygen difference (AVO2) across the pancreatic circulation and SPBF. Drugs were infused into the superior pancreatico-duodenal artery. BK (0.01-1.0 mg/kg/min) increased maximally SPBF by 180 +/- 15%, PBF by 208 +/- 22% and PVO2 by 145 +/- 11%, respectively. Pretreatment with B2-subtype receptor antagonist, D-Arg, [Hyp3, Thi5,8, D-Phe7] BK inhibited significantly BK-induced increase in SPBF, PBF and PVO2 by 86 +/- 8%, 73 +/- 7% and 85 +/- 6%, respectively. A nitric oxide synthesis inhibitor (L-NNA) administered i.v. at dose of 25 mg/kg 20 min before BK, inhibited significantly the pancreatic hyperemic and metabolic responses. The results presented emphasize an important role of B2 receptors in the mediation of pancreatic circulatory and metabolic responses to bradykinin. Endogenous NO plays a mediatory role in the pancreatic vascular and metabolic responses due to stimulation of B2-receptors.     

Reliability considerations in accelerated life testing ofelectrical insulation with generalized life distribution function

The authors introduced a new approach to estimate life distributions at nominal conditions from the results of accelerated life testing of electrical insulating materials. A very general family of probability distributions is introduced, and a best fit member of this family is used to represent life data at each stress level. Nonlinear optimization techniques are applied in conjunction with linear regression analysis. In any accelerated life testing study important questions pertain to the minimal and maximal stress levels to be applied. A method of determination of the minimal stress level as well as the suitable number of tests based on reliability considerations is presented. A numerical example based on test data and a user-friendly computer program are presented     

Bacterial Infection and Non-Hodgkin B-Cell Lymphoma: Interactions between Pathogen,Host and the Tumor Environment

Non-Hodgkin B-cell lymphomas (NHL) are a heterogeneous group of lymphoid neoplasms with complex etiopathology, rich symptomatology, and a variety of clinical courses, therefore requiring different therapeutic approaches. The hypothesis that an infectious agent may initiate chronic inflammation and facilitate B lymphocyte transformation and lymphogenesis has been raised in recent years. Viruses, like EBV, HTLV-1, HIV, HCV and parasites, like Plasmodium falciparum, have been linked to the development of lymphomas. The association of chronic Helicobacter pylori (H. pylori) infection with mucosa-associated lymphoid tissue (MALT) lymphoma, Borrelia burgdorferi with cutaneous MALT lymphoma and Chlamydophila psittaci with ocular adnexal MALT lymphoma is well documented. Recent studies have indicated that other infectious agents may also be relevant in B-cell lymphogenesis such as Coxiella burnettii, Campylobacter jejuni, Achromobacter xylosoxidans, and Escherichia coli. The aim of the present review is to provide a summary of the current literature on infectious bacterial agents associated with B-cell NHL and to discuss its role in lymphogenesis, taking into account the interaction between infectious agents, host factors, and the tumor environment.     

Three Component Composite Scaffolds Based on PCL,Hydroxyapatite, and L-Lysine Obtained in TIPS-SL: Bioactive Material for Bone Tissue Engineering

In this research, we describe the properties of three-component composite foam scaffolds based on poly(ε-caprolactone) (PCL) as a matrix and hydroxyapatite whiskers (HAP) and L-Lysine as fillers (PCL/HAP/Lys with wt% ratio 50/48/2). The scaffolds were prepared using a thermally induced phase separation technique supported by salt leaching (TIPS-SL). All materials were precisely characterized: porosity, density, water uptake, wettability, DSC, and TGA measurements and compression tests were carried out. The microstructure of the obtained scaffolds was analyzed via SEM. It was found that the PCL/HAP/Lys scaffold has a 45% higher Young’s modulus and better wettability compared to the PCL/HAP system. At the same time, the porosity of the system was ~90%. The osteoblast hFOB 1.19 cell response was also investigated in osteogenic conditions (39 °C) and the cytokine release profile of interleukin (IL)-1β, IL-6, and tumor necrosis factor (TNF)-α was determined. Modification of PCL scaffolds with HAP and L-Lysine significantly improved the proliferation of pre-osteoblasts cultured on such materials.     

Sequential phosphorylation of Tau by glycogen synthase kinase-3beta and protein kinase A at Thr212 and Ser214 generates the Alzheimer-specific epitope of antibody AT100 and requires a paired-helical-filament-like conformation

AT100 is a monoclonal antibody highly specific for phosphorylated Tau in Alzheimer paired helical filaments. Here we show that the epitope is generated by a complex sequence of sequential phosphorylation, first of Ser199, Ser202 and Thr205 (around the epitope of antibody AT8), next of Thr212 by glycogen synthase kinase (GSK)-3beta (a proline-directed kinase), then of Ser214 by protein kinase A (PKA). Conversely, if Ser214 is phosphorylated first it protects Thr212 and the Ser-Pro motifs around the AT8 site against phosphorylation, and the AT100 epitope is not formed. The generation of the AT100 epitope requires a conformation of tau induced by polyanions such as heparin, RNA or poly(Glu), conditions which also favor the formation of paired helical filaments. The Alzheimer-like phosphorylation can be induced by brain extracts. In the extract, the kinases responsible for generating the AT100 epitope are GSK-3beta and PKA, which can be inhibited by their specific inhibitors LiCl and RII, respectively. A cellular model displaying the reaction with AT100 is presented by Sf9 insect cells transfected with Tau. Knowledge of the events and kinases generating the AT100 epitope in cells might allow us to study the degeneration of the cytoskeleton in Alzheimer's disease.     

Influence of bioflavonoids from the radix extract of Scutellaria baicalensis on the level of serum lipids, and the development of laboratory rats fed with fresh and oxidized fats

The aim of this study was to assess the influence of bioflavonoids from the radix of Scurellaria baicalensis on the level of lipids, via the determination of the concentrations of triglycerides, total cholesterol and high-density lipoprotein (HDL) cholesterol in the plasma of laboratory rats fed high-fat and high-cholesterol diets, and via the calculation of their atherogenic index. We also studied the influence of bioflavonoids on their physical development by measuring the increase in their body mass and liver mass. The rats were fed a diet with a 15% content of fresh or oxidized lard or sunflower oil, along with 0.5% added cholesterol. 0.05% S. baicalensis radix extract was added to the diet of half of the rats as the source of bioflavonoids. In the group of rats fed a diet containing oxidized oil we observed a significantly lower increase in body mass (15.5 +/- 7.6 g/4 weeks/rat) than that observed for the control rats (77.0 +/- 15.7 g/4 weeks/rat). The addition of S. baicalensis radix extract to the diet raised the increase in body mass in the groups receiving oil as the source of fat; those receiving fresh oil had a 40% increase, and those receiving oxidized oil showed a 300% increase relative to the appropriate controls. In all the groups of rats fed a diet with bioflavonoids added, a beneficial decrease in the plasma triglyceride content was observed relative to the appropriate controls. In the plasma of rats on a diet containing the extract and fresh or oxidized oil or fresh lard, we observed a beneficial reduction in the total cholesterol level relative to the appropriate controls. The atherogenic index was higher for the group of animals fed with fresh lard than for those fed with fresh oil, and higher for those fed with oxidized oil than for those fed with oxidized lard. The addition of bioflavonoids to the diet beneficially reduced the atherogenic index value in the group fed with fresh oil, and increased its value in the group fed with oxidized lard.