981 resultados para G-Hilbert Scheme
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-Essential hypertensives display enhanced signal transduction through pertussis toxin-sensitive G proteins. The T allele of a C825T variant in exon 10 of the G protein beta3 subunit gene (GNB3) induces formation of a splice variant (Gbeta3-s) with enhanced activity. The T allele of GNB3 was shown recently to be associated with hypertension in unselected German patients (frequency=0.31 versus 0.25 in control). To confirm and extend this finding in a different setting, we performed an association study in Australian white hypertensives. This involved an extensively examined cohort of 110 hypertensives, each of whom were the offspring of 2 hypertensive parents, and 189 normotensives whose parents were both normotensive beyond age 50 years. Genotyping was performed by polymerase chain reaction and digestion with BseDI, which either cut (C allele) or did not cut (T allele) the 268-bp polymerase chain reaction product. T allele frequency in the hypertensive group was 0.43 compared with 0.25 in the normotensive group (chi2=22; P=0.00002; odds ratio=2.3; 95% CI=1.7 to 3.3). The T allele tracked with higher pretreatment blood pressure: diastolic=105+/-7, 109+/-16, and 128+/-28 mm Hg (mean+/-SD) for CC, CT, and TT, respectively (P=0.001 by 1-way ANOVA). Blood pressures were higher in female hypertensives with a T allele (P=0.006 for systolic and 0.0003 for diastolic by ANOVA) than they were in male hypertensives. In conclusion, the present study of a group with strong family history supports a role for a genetically determined, physiologically active splice variant of the G protein beta3 subunit gene in the causation of essential hypertension.
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Unsteady nonsimilar laminar compressibletwo-dimensional and axisymmetric boundarylayer flows have been studied when external velocity varies arbitrarily with time and the flow is nonhomentropic. The governing nonlinear partial differential equations with three independent variables have been solved using an implicit finite difference scheme with quasilinearization technique from the origin to the point of zero skin-friction. The results have been obtained for (i) an accelerating stream and (ii) a fluctuating stream. The skin friction responds to the fluctuations in the free stream more compared to the heat transfer. It is observed that Mach number and hot wall cause the point of zero skin friction to occur earlier whereas cold wall delays it.
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Screening of wastewater effluents from municipal and industrial wastewater treatment plants with biotests showed that the treated wastewater effluents possess only minor acute toxic properties towards whole organisms (e.g. bacteria, algae, daphnia), if any. In vitro tests (sub-mitochondrial membranes and fish hepatocytes) were generally more susceptible to the effluents. Most of the effluents indicated the presence of hormonally active compounds, as the production of vitellogenin, an egg yolk precursor protein, was induced in fish hepatocytes exposed to wastewater. In addition, indications of slight genotoxic potential was found in one effluent concentrate with a recombinant bacteria test. Reverse electron transport (RET) of mitochondrial membranes was used as a model test to conduct effluent assessment followed by toxicant characterisations and identifications. Using a modified U.S. EPA Toxicity Identification Evaluation Phase I scheme and additional case-specific methods, the main compound in a pulp and paper mill effluent causing RET inhibition was characterised to be an organic, relatively hydrophilic high molecular weight (HMW) compound. The toxicant could be verified as HMW lignin by structural analyses using nuclear magnetic resonance. In the confirmation step commercial and in-house extracted lignin products were used. The possible toxicity related structures were characterised by statistical analysis of the chemical breakdown structures of laboratory-scale pulping and bleaching effluents and the toxicities of these effluents. Finally, the biological degradation of the identified toxicant and other wastewater constituents was evaluated using bioassays in combination with chemical analyses. Biological methods have not been used routinely in establishing effluent discharge limits in Finland. However, the biological effects observed in this study could not have been predicted using only routine physical and chemical effluent monitoring parameters. Therefore chemical parameters cannot be considered to be sufficient in controlling effluent discharges especially in case of unknown, possibly bioaccumulative, compounds that may be present in small concentrations and may cause chronic effects.
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This paper suggests a scheme for classifying online handwritten characters, based on dynamic space warping of strokes within the characters. A method for segmenting components into strokes using velocity profiles is proposed. Each stroke is a simple arbitrary shape and is encoded using three attributes. Correspondence between various strokes is established using Dynamic Space Warping. A distance measure which reliably differentiates between two corresponding simple shapes (strokes) has been formulated thus obtaining a perceptual distance measure between any two characters. Tests indicate an accuracy of over 85% on two different datasets of characters.
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This paper presents a general hardware scheme for testing protective relays using microprocessor based systems. The microprocessor simulates the relaying signals for test purpose and monitors the relay performance. Based on the proposed hardware, a teat procedure for directional overcurrent relays is presented in detail. Typical test results of various routine tests conducted on a commercial single phase directional over-current relay clearly demonstrate the efficacy of the proposed technique for conducting tests on commercial relays.
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Objective To assess the impact of exercise referral schemes on physical activity and health outcomes. Design Systematic review and meta-analysis. Data sources Medline, Embase, PsycINFO, Cochrane Library, ISI Web of Science, SPORTDiscus, and ongoing trial registries up to October 2009. We also checked study references. Study selection - Design: randomised controlled trials or non-randomised controlled (cluster or individual) studies published in peer review journals. - Population: sedentary individuals with or without medical diagnosis. - Exercise referral schemes defined as: clear referrals by primary care professionals to third party service providers to increase physical activity or exercise, physical activity or exercise programmes tailored to individuals, and initial assessment and monitoring throughout programmes. - Comparators: usual care, no intervention, or alternative exercise referral schemes. Results Eight randomised controlled trials met the inclusion criteria, comparing exercise referral schemes with usual care (six trials), alternative physical activity intervention (two), and an exercise referral scheme plus a self determination theory intervention (one). Compared with usual care, follow-up data for exercise referral schemes showed an increased number of participants who achieved 90-150 minutes of physical activity of at least moderate intensity per week (pooled relative risk 1.16, 95% confidence intervals 1.03 to 1.30) and a reduced level of depression (pooled standardised mean difference −0.82, −1.28 to −0.35). Evidence of a between group difference in physical activity of moderate or vigorous intensity or in other health outcomes was inconsistent at follow-up. We did not find any difference in outcomes between exercise referral schemes and the other two comparator groups. None of the included trials separately reported outcomes in individuals with specific medical diagnoses. Substantial heterogeneity in the quality and nature of the exercise referral schemes across studies might have contributed to the inconsistency in outcome findings. Conclusions Considerable uncertainty remains as to the effectiveness of exercise referral schemes for increasing physical activity, fitness, or health indicators, or whether they are an efficient use of resources for sedentary people with or without a medical diagnosis.
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Background The effectiveness of exercise referral schemes (ERS) is influenced by uptake and adherence to the scheme. The identification of factors influencing low uptake and adherence could lead to the refinement of schemes to optimise investment. Objectives To quantify the levels of ERS uptake and adherence and to identify factors predictive of uptake and adherence. Methods A systematic review and meta-analysis was undertaken. MEDLINE, EMBASE, PsycINFO, Cochrane Library, ISI WOS, SPORTDiscus and ongoing trial registries were searched (to October 2009) and included study references were checked. Included studies were required to report at least one of the following: (1) a numerical measure of ERS uptake or adherence and (2) an estimate of the statistical association between participant demographic or psychosocial factors (eg, level of motivation, self-efficacy) or programme factors and uptake or adherence to ERS. Results Twenty studies met the inclusion criteria, six randomised controlled trials (RCTs) and 14 observational studies. The pooled level of uptake in ERS was 66% (95% CI 57% to 75%) across the observational studies and 81% (95% CI 68% to 94%) across the RCTs. The pooled level of ERS adherence was 49% (95% CI 40% to 59%) across the observational studies and 43% (95% CI 32% to 54%) across the RCTs. Few studies considered anything other than gender and age. Women were more likely to begin an ERS but were less likely to adhere to it than men. Older people were more likely to begin and adhere to an ERS. Limitations Substantial heterogeneity was evident across the ERS studies. Without standardised definitions, the heterogeneity may have been reflective of differences in methods of defining uptake and adherence across studies. Conclusions To enhance our understanding of the variation in uptake and adherence across ERS and how these variations might affect physical activity outcomes, future trials need to use quantitative and qualitative methods.
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Viruses of the genus Mastrevirus (family Geminiviridae) are transmitted by leafhoppers and infect either mono- or dicotyledonous plants. Here we have determined the full length sequences of 49 dicot-infecting mastrevirus isolates sampled in Australia, Eritrea, India, Iran, Pakistan, Syria, Turkey and Yemen. Comprehensive analysis of all available dicot-infecting mastrevirus sequences showed the diversity of these viruses in Australia to be greater than in the rest of their known range, consistent with earlier studies, and that, in contrast with the situation in monocot-infecting mastreviruses, detected inter-species recombination events outnumbered intra-species recombination events. Consistent with Australia having the greatest diversity of known dicot-infecting mastreviruses phylogeographic analyses indicating the most plausible scheme for the spread of these viruses to their present locations, suggest that most recent common ancestor of these viruses is likely nearer Australia than it is to the other regions investigated.
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The influence of grazing management on total soil organic carbon (SOC) and soil total nitrogen (TN) in tropical grasslands is an issue of considerable ecological and economic interest. Here we have used linear mixed models to investigate the effect of grazing management on stocks of SOC and TN in the top 0.5 m of the soil profile. The study site was a long-term pasture utilization experiment, 26 years after the experiment was established for sheep grazing on native Mitchell grass (Astrebla spp.) pasture in northern Australia. The pasture utilization rates were between 0% (exclosure) and 80%, assessed visually. We found that a significant amount of TN had been lost from the top 0.1 m of the soil profile as a result of grazing, with 80% pasture utilization resulting in a loss of 84 kg ha−1 over the 26-year period. There was no significant effect of pasture utilization rate on TN when greater soil depths were considered. There was no significant effect of pasture utilization rate on stocks of SOC and soil particulate organic carbon (POC), or the C:N ratio at any depth; however, visual trends in the data suggested some agreement with the literature, whereby increased grazing pressure appeared to: (i) decrease SOC and POC stocks; and, (ii) increase the C:N ratio. Overall, the statistical power of the study was limited, and future research would benefit from a more comprehensive sampling scheme. Previous studies at the site have found that a pasture utilization rate of 30% is sustainable for grazing production on Mitchell grass; however, given our results, we conclude that N inputs (possibly through management of native N2-fixing pasture legumes) should be made for long-term maintenance of soil health, and pasture productivity, within this ecosystem.
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This paper proposes a novel modulation strategy for a phase controlled Capacitor-Inductor-Capacitor (CLC) Resonant Dual Active Bridge (RDAB). The proposed modulation strategy improves the soft turn-on, Zero-Current-Switching (ZCS) and Zero-Voltage-Switching (ZVS) range of the converter while only minimally increasing the required reactive currents in the ac link. A mathematical analysis of the proposed modulation scheme is presented along with a theoretical loss comparison between several modulation strategies. The proposed modulation strategy was implemented and the experimental results are presented.
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