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Refined Analysis (refined + analysis)
Selected AbstractsRefined analysis of genetic variability parameters in hepatitis C virus and the ability to predict antiviral treatment responseJOURNAL OF VIRAL HEPATITIS, Issue 8 2008J. M. Cuevas Summary., Hepatitis C virus (HCV) infects approximately 3% of the world population. The chronicity of hepatitis C seems to depend on the level of genetic variability. We have recently (Torres-Puente et al., J Viral Hepat, 2008; 15: 188) reported genetic variability estimates from a large-scale sequence analysis of 67 patients infected with HCV subtypes 1a (23 patients) and 1b (44 patients) and related them to response, or lack of, to alpha-interferon plus ribavirin treatment.. Two HCV genome regions were analysed in samples prior to antiviral therapy, one compressing the three hypervariable regions of the E2 glycoprotein and another one including the interferon sensitive determining region and the V3 domain of the NS5A protein. Haplotype and nucleotide diversity measures showed a clear tendency to higher genetic variability levels in nonresponder than in responder patients. Here, we have refined the analysis of genetic variability (haplotype and nucleotide diversity, number of haplotypes and mutations) by considering their distribution in each of the biologically meaningful subregions mentioned above, as well as in their surrounding and intervening regions. Variability levels are very heterogeneous among the different subregions, being higher for nonresponder patients. Interestingly, significant differences were detected in the biologically relevant regions, but also in the surrounding regions, suggesting that the level of variability of the whole HCV genome, rather than exclusively that from the hypervariable regions, is the main indicator of the treatment response. Finally, the number of haplotypes and mutations seem to be better discriminators than haplotype and nucleotide diversity, especially in the NS5A region. [source] Fossil fruits of Salsola L. s.l. and Halanthium K.Koch (Chenopodiaceae) from Lower Pleistocene lacustrine sediments in Armenia,FEDDES REPERTORIUM, Issue 3-4 2008Janna Akopian Dr. For the first time imprints of fossil fruits of Salsola L. s.l. and Halanthium K.Koch (Chenopodiaceae, Salsoloideae,) are reported from the territory of Armenia, the latter being the first fossil record of the Southwest Asian genus worldwide. They were collected from fluvio-lacustrine diatomite layers of the Lower Pleistocene (Sisian series) in the upper-middle Vorotan river valley recently dated at 1.4,0.935 my (Early Pleistocene). The fossils are described, figured and compared with recent relatives. Due to poor preservation, the identity of the Salsola fruit cannot be specified but the similar genus Kochia can be excluded. The Halanthium fruit seems to differ from those of extant species. Both are also discussed in the context of the very poor fossil Salsoloideae record and of the actual and lower Pleistocene vegetation and environment. The findings of truly semidesert species underline the presence of open landscapes and extremely semiarid to arid conditions. However, stratigraphically more refined analyses are needed to draw conclusions about the former vegetation and the duration of arid periods because most macrofossils reported from the same strata indicate semiarid and even humid environments. (© 2008 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim) Fossile Früchte von Salsola L. und Halanthium K.Koch (Chenopodiaceae) aus unterpleistozänen lakustrischen Sedimenten in Armenien Erstmals wird über Funde fossiler Früchte der Gattungen Salsola L. s.l. und Halanthium K.Koch (Chenopodiaceae, Salsoloideae) aus Armenien berichtet. Für die letztere Gattung handelt es sich weltweit um einen Erstfund. Die nur mäßig guten Abdrucke stammen aus fluvio-lakustrischen Diatomiten der Sisian Serie vom oberen Vorotan-Tal, die nach neuesten Datierungen 1,4,0,935 Millionen Jahre alt sind und damit in das Unterpleistozän gehören. Die Fossilien werden beschrieben, abgebildet und mit den nächsten rezenten Verwandten verglichen. Während bei der Salsola -Frucht wegen Beschädigungen vor der Einbettung keine Artbestimmung möglich ist, die Zugehörigkeit zu Kochia aber ausgeschlossen werden kann, stimmt die besser erhaltene Halanthium- Frucht mit keiner rezenten Art überein. Beide Arten werden im Zusammenhang mit dem bisher äußerst spärlichen Fossilbefund und im Hinblick auf ihren möglichen ökologischen und vegetationskundlichen Indikatorwert diskutiert. Die Nachweise dieser Halbwüstenpflanzen sprechen für eine waldfreie Umgebung und ein extremsemiarides oder arides Klima zur Zeit der Einbettung. Die gleichen Schichten enthalten aber vor allem Makrofossilien mesophytischer Gehölze, die an ein semiarides bis humides Klima gebunden sind. Weitergehende Rückschlüsse sind erst dann möglich, wenn eine feinstratigraphische Analyse vorliegt, durch die größere klimatische Fluktuationen nachgewiesen werden könnten. [source] GENETIC STUDY: Association between dopamine transporter genotypes and smoking cessation: a meta-analysisADDICTION BIOLOGY, Issue 2 2007John A. Stapleton ABSTRACT This review assessed the evidence of an association between genotypes of the dopamine transporter (DAT1, SLC6A3) 3, untranslated region (3,UTR) variable number of tandem repeats (VNTR) and smoking cessation. Five studies (seven cohorts) comprising 2155 subjects were included in the meta-analysis. All gave data on the number of smokers who had stopped smoking and the number still smoking for those with one or more variant 9-repeat alleles and other genotypes. Three studies (comprising five cohorts) were cross-sectional population surveys and two were smoking cessation treatment programs with follow-up. Four of the five studies (six of the seven cohorts) showed a trend in favor of cessation when the variant 9-repeat allele was present, although only one study showed a statistically significant effect. The pooled odds ratio in favor of a greater likelihood of cessation for the variant 9-repeat allele was 1.15 [95% confidence interval (CI) = 0.97,1.37]. In a more refined analysis where cohorts within studies were treated as separate samples and adjusted odds ratios were used, the overall pooled odds ratio in favor of cessation with the 9-repeat alleles was 1.20 (95% CI = 1.01,1.43). These results support the hypothesis that the DAT1 3,UTR VNTR polymorphism is associated with smoking cessation. One or more variant 9-repeat alleles relative to the more common 10-repeat allele confers a greater likelihood of cessation, indicative of lower dependence on tobacco. The effect was a 20% increase in the odds of cessation for those with a variant allele. [source] The Effect of Board Independence on Target Shareholder WealthAUSTRALIAN ACCOUNTING REVIEW, Issue 2 2008Peter M. Clarkson We seek insights into whether, and if so how, an independent board enhances the bid premiums offered to target firm shareholders during a takeover. The results indicate that the presence of an independent board enhances the initial bid premium by, on average, 21.1%. However, the results of more refined analysis suggest that the enhanced bid premium is in fact driven by independent boards comprising non-executive directors who have reputation capital at stake. We also find that independent boards that resist takeovers or include voluntary independent expert reports in target statements, increase the bid premium revision by, on average, 15.6% and 16.2%, respectively. [source] | ||||||||||