74 research outputs found
ELAC2 polymorphisms and prostate cancer risk: a meta-analysis based on 18 case–control studies
Polymorphisms in the elaC homolog-2 (ELAC2)/HPC2 gene have been hypothesized to alter the risk of prostate cancer. However, the results of the related published studies remained conflicting. We performed a meta-analysis of 18 studies evaluating the association between ELAC2 Ser217Leu and Ala541Thr polymorphisms and prostate cancer risk. Overall, ELAC2 Leu217 allele was associated with increased prostate cancer risk as compared with the Ser217 allele (odds ratio (OR)=1.13, 95% confidence interval (CI): 1.03–1.24, P=0.019 for heterogeneity), as well as in the heterozygote comparison (OR=1.21, 95% CI: 1.07–1.36, P=0.034 for heterogeneity) and the dominant genetic model (OR=1.20, 95% CI: 1.07–1.35, P=0.025 for heterogeneity). Furthermore, the ELAC2 Thr541 allele was associated with increased prostate cancer risk as compared with the Ala541 allele (OR=1.22, 95% CI: 1.00–0.48, P=0.131 for heterogeneity). In the stratified analyses for Ser217Leu polymorphism, there was significantly increased prostate cancer risk in Asian and Caucasian populations, and studies using sporadic and familial prostate cancer cases. Similar result was found in the Asian population in the stratified analyses for Ala541Thr polymorphism. This meta-analysis showed evidence that ELAC2 Ser217Leu and Ala541Thr polymorphisms were associated with prostate cancer risk, and might be low-penetrance susceptibility markers of prostate cancer
Prostate cancer in BRCA2 germline mutation carriers is associated with poorer prognosis
BACKGROUND: The germline BRCA2 mutation is associated with increased prostate cancer (PrCa) risk. We have assessed survival in young PrCa cases with a germline mutation in BRCA2 and investigated loss of heterozygosity at BRCA2 in their tumours. METHODS: Two cohorts were compared: one was a group with young-onset PrCa, tested for germline BRCA2 mutations (6 of 263 cases had a germline BRAC2 mutation), and the second was a validation set consisting of a clinical set from Manchester of known BRCA2 mutuation carriers (15 cases) with PrCa. Survival data were compared with a control series of patients in a single clinic as determined by Kaplan-Meier estimates. Loss of heterozygosity was tested for in the DNA of tumour tissue of the young-onset group by typing four microsatellite markers that flanked the BRCA2 gene, followed by sequencing. RESULTS: Median survival of all PrCa cases with a germline BRCA2 mutation was shorter at 4.8 years than was survival in controls at 8.5 years (P = 0.002). Loss of heterozygosity was found in the majority of tumours of BRCA2 mutation carriers. Multivariate analysis confirmed that the poorer survival of PrCa in BRCA2 mutation carriers is associated with the germline BRCA2 mutation per se. CONCLUSION: BRCA2 germline mutation is an independent prognostic factor for survival in PrCa. Such patients should not be managed with active surveillance as they have more aggressive disease. British Journal of Cancer (2010) 103, 918-924. doi:10.1038/sj.bjc.6605822 www.bjcancer.com Published online 24 August 2010 (C) 2010 Cancer Research U
The digestion of protein and carbohydrate by the stream detritivore, Tipula abdominalis (Diptera, Tipulidae)
The digestive system of larvae of Tipula abdominalis (Diptera, Tipulidae), a stream detritivore, is poorly adapted for the digestion of the major polysaccharides in its diet, but well adapted for the digestion of protein. These crane fly larvae are unable to digest the major cell wall polysaccharides of higher plants, i.e., cellulose, hemicellulose and pectin. The only polysaccharides toward which the midguts of T. abdominalis exhibited any activity were α-amylose and laminarin, indicating that polysaccharide digestion is restricted to α-1,4-and β-1,3-glucans. The most concentrated source of these two classes of carbohydrates in submerged leaf litter would be associated fungal tissue. The midgut of T. abdominalis is strongly alkaline throughout, with a maximum pH near 11.5 in a narrow zone near the midpoint. Proteolytic activity in the midgut is extraordinarily high, and the pH optimum for midgut proteolytic activity is above 11. We conclude that the high alkalinity and high proteolytic activity observed in T. abdominalis larvae are manifestations of a highly efficient protein-digesting system, a system of crucial importance to a nitrogen-limited organism which must derive its nitrogen from a resource in which much of the limited nitrogen present is in a “bound” form in complexes of proteins with lignins and polyphenols.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/47733/1/442_2004_Article_BF00346265.pd
Catálogo de autoridades da Rede BIM (DPHDM): Estudo de caso no tratamento de registros de pontos de acesso
Identificar possĂveis problemas na alimentação da base de autoridades de assuntos da Rede BIM atravĂ©s da utilização do software Pergamum, e contribuir para padronização de seus pontos de acesso. A partir da revisĂŁo da literatura proposta, considera a importância da recuperação da informação para sua disseminação e ainda faz um breve levantamento dos padrões internacionais utilizados para esse fim. A metodologia utilizada envolveu a análise da base, limitada Ă letra “c” do alfabeto, e se propĂ´s a detectar possĂveis inconsistĂŞncias existentes. Os principais problemas encontrados foram: falhas de grafia, falhas de entrada de cabeçalhos e duplicidade de assuntos. Os resultados práticos para a Rede BIM sĂŁo: agilização dos serviços de catalogação e referĂŞncia da Rede BIM, maior controle bibliográfico e facilidade na recuperação de itens nas pesquisas dos usuários. O Estudo de caso se propõe a contribuir com esclarecimentos quanto a equĂvocos cometidos, de forma a auxiliar na padronização e documentação do processo de alimentação da base de autoridades de assuntos pelos bibliotecários das 45 organizações militares, possibilitando benefĂcios aos serviços de catalogação e referĂŞncia e finalmente, propiciando um atendimento mais prático e ágil ao usuário da Rede BIM
Semi-automatic non-linear model selection,
We consider model selection for nonlinear dynamic equations with more candidate variables than observations, based on a general class of nonlinear-in-the-variables functions, addressing possible location shifts by impulse-indicator saturation. After an automatic search delivers a simplified congruent terminal model, an encompassing test can be implemented against an investigator’s preferred nonlinear function. When that is nonlinear in the parameters, such as a threshold model, the overall approach can only be semi-automatic. The method is applied to re-analyze an empirical model of real wages in the UK over 1860–2004, updated and extended to 2005–2011 for forecast evaluation. </p
A Multiple Regime Nonlinear Asymmetric AR(p)-GARCH(1,1) Model
In this article a multiple regime extension for the Heston-Nandi GARCH(1,1) model is presented to describe the asymmetries and intermittent dynamics in financial volatility. The statistical properties and the estimation of their parameters are addressed in detail. The number of regimes in the model is determined through a statistical procedure based on a novel robust Lagrange Multiplier (LM) specification. The ability of the model to forecast financial market volatility is empirically compared to other GARCH models for a set comprising some of the major world stock indexes and their corresponding foreign exchange rates during the recent financial crisis
Reynolds-Averaged Navier-Stokes Calculations Of Unsteady Turbulent Flow
In this study, a combination of the unsteady incompressible Navier-Stokes equations in vorticityvelocity formulation and the Algebraic Stress Model (ASM) of Gatski and Speziale (1996) is employed for Unsteady Reynolds Averaged Navier-Stokes (URANS) calculations of turbulent boundary layer flows. The Navier-Stokes equations are solved using a fourth-order compact difference scheme in space and a fourth-order Runge-Kutta method in time. The highly accurate numerical method greatly reduces the possibility of contamination of the results by second-order artificial dissipation from the numerical schemes. A flat plate boundary layer subjected to a strong adverse pressure gradient with laminar separation and turbulent reattachment is investigated. Performing URANS calculations for this flow, we found that unsteady vortical structures remain in the flow field despite the large "effective eddy viscosity" produced by the turbulence model (ASM). This is due to the fact that a special function is ..
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