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Selected AbstractsNo evidence for association of the TP53 12139 and the BAX,248 polymorphisms with endemic pemphigus foliaceus (fogo selvagem)INTERNATIONAL JOURNAL OF IMMUNOGENETICS, Issue 2 2006K. F. Köhler Summary Pemphigus foliaceus (PF) is an autoimmune bullous epidermal disease, characterized by autoantibodies specific to the desmosomal protein desmoglein 1 (dsg1) and by acantholysis, the rupture of the cellular junctions among keratinocytes. Known also as fogo selvagem (wild fire) in Brazil, the disease has distinct epidemiological characteristics, being endemic in certain regions of South America. It is a multifactorial (complex) disease, with oligo- or polygenic disease susceptibility. In view of the previously reported evidences of a role for apoptosis dysregulation in pemphigus pathogenesis, we hypothesized that genetic variants of molecules participating in apoptosis may contribute to interindividual variation of susceptibility to PF. The TP53 12139(G,C) and the BAX,248(G,A) single nucleotide polymorphisms (SNP) were analysed in a genetic association study. The allelic, genotypic and allele carrier frequencies for these SNPs did not differ statistically between the patient and the control groups, for both the Euro- and the Afro-Brazilian population strata. The results of this study lead us to conclude that, although the TP53 and BAX alleles analysed differ functionally, this variation does not alter the functionality of the molecules in a way that would interfere with the development of the disease. [source] Digital artifacts as quasi-objects: Qualification, mediation, and materialityJOURNAL OF THE AMERICAN SOCIETY FOR INFORMATION SCIENCE AND TECHNOLOGY, Issue 12 2009Hamid R. Ekbia Digital artifacts have novel properties that largely derive from the processes that mediate their creation, and that can be best understood by a close examination of such processes. This paper introduces the concept of "quasi-object" to characterize these objects and elucidate the activities that comprise their mediations. A case study of "bugs" is analyzed to illustrate exemplary activities of justification, qualification, and binding in the process of bug fixing in Free/Open Source Software development. The findings of the case study lead to broader reflections on the character of digital artifacts in general. The relationship of "quasi-object" to other similar concepts are explored. [source] Absence of population substructuring in Zimbabwe chicken ecotypes inferred using microsatellite analysisANIMAL GENETICS, Issue 4 2007F. C. Muchadeyi Summary The objective of this study was to investigate the population structure of village chickens found in the five agro-ecological zones of Zimbabwe. Twenty-nine microsatellites were genotyped for chickens randomly selected from 13 populations, including the five eco-zones of Zimbabwe (n = 238), Malawi (n = 60), Sudan (n = 48) and six purebred lines (n = 180). A total of 280 alleles were observed in the 13 populations. Forty-eight of these alleles were unique to the Zimbabwe chicken ecotypes. The average number (±SD) of alleles/locus was 9.7 ± 5.10. The overall heterozygote deficiency in the Zimbabwe chickens (FIT ± SE) was 0.08 ± 0.01, over 90% of which was due to within-ecotype deficit (FIS). Small Nei's standard genetic distances ranging from 0.02 to 0.05 were observed between Zimbabwe ecotypes compared with an average of 0.6 between purebred lines. The structure software program was used to cluster individuals to 2 , K , 7 assumed clusters. The most probable clustering was found at K = 6. Ninety-seven of 100 structure runs were identical, in which Malawi, Sudan and purebred lines split out as independent clusters and the five Zimbabwe ecotypes clustered into one population. The within-ecotype marker-estimated kinships (mean = 0.13) differed only slightly from the between-ecotype estimates. Results from this study lead to a rejection of the hypothesis that village chickens are substructured across agro-ecological zones but indicated high genetic diversity within the Zimbabwe chicken population. [source] A thermodynamic analysis of the anaerobic oxidation of methane in marine sedimentsGEOBIOLOGY, Issue 5 2008D. E. LAROWE ABSTRACT Anaerobic oxidation of methane (AOM) in anoxic marine sediments is a significant process in the global methane cycle, yet little is known about the role of bulk composition, temperature and pressure on the overall energetics of this process. To better understand the biogeochemistry of AOM, we have calculated and compared the energetics of a number of candidate reactions that microorganisms catalyse during the anaerobic oxidation of methane in (i) a coastal lagoon (Cape Lookout Bight, USA), (ii) the deep Black Sea, and (iii) a deep-sea hydrothermal system (Guaymas basin, Gulf of California). Depending on the metabolic pathway and the environment considered, the amount of energy available to the microorganisms varies from 0 to 184 kJ mol,1. At each site, the reactions in which methane is either oxidized to , acetate or formate are generally only favoured under a narrow range of pressure, temperature and solution composition , particularly under low (10,10 m) hydrogen concentrations. In contrast, the reactions involving sulfate reduction with H2, formate and acetate as electron donors are nearly always thermodynamically favoured. Furthermore, the energetics of ATP synthesis was quantified per mole of methane oxidized. Depending on depth, between 0.4 and 0.6 mol of ATP (mol CH4),1 was produced in the Black Sea sediments. The largest potential productivity of 0.7 mol of ATP (mol CH4),1 was calculated for Guaymas Basin, while the lowest values were predicted at Cape Lookout Bight. The approach used in this study leads to a better understanding of the environmental controls on the energetics of AOM. [source] The sting at the end of the tail: Damaging winds associated with extratropical cyclonesTHE QUARTERLY JOURNAL OF THE ROYAL METEOROLOGICAL SOCIETY, Issue 597 2004K. A. Browning Abstract Strong surface winds often accompany the low-level jets that occur along the cold fronts of extratropical cyclones, but there is evidence that the strongest surface winds occur in a distinctly different part of a certain class of cyclone. The most damaging extratropical cyclones go through an evolution that involves the formation of a bent-back front and cloud head separated from the main polar-front cloud band by a dry slot. When the cyclone attains its minimum central pressure, the trailing tip of the cloud head bounding the bent-back front forms a hook which goes on to encircle a seclusion of warm air. The most damaging winds occur near the tip of this hook,the sting at the end of the tail. Observations of the Great Storm of October 1987 in south-east England are re-examined in some detail to study this phenomenon. The cloud head is shown to have a banded structure consistent with the existence of multiple mesoscale slantwise circulations. Air within these circulations leaves the hooked tip of the cloud head (and enters the dry slot) much faster than the rate of travel of the cloud-head tip, implying rapid evaporation and diabatic cooling immediately upwind of the area of damaging surface winds. The circumstantial evidence from the observational study leads one to hypothesize that the mesoscale circulations and the associated evaporative heat sinks may play an active role in strengthening the damaging winds. Regardless of how important this role may be, the evolution of the cloud pattern seen in satellite imagery is a useful tool for nowcasting the occurrence and location of the worst winds. Copyright © 2004 Royal Meteorological Society [source] Inferring Haplotype/Disease Association by Joint Use of Case-Parents Trios and Case-Parent PairsANNALS OF HUMAN GENETICS, Issue 3 2010Yue-Qing Hu Summary Recently interest has been increasing in genetic association studies using several closely linked loci. The HAP-TDT method, which uses case-parents trios is powerful for such a task. However, it is not uncommon in practice that one parent is missing for some reason, such as late onset. The case-parents trios are thus reduced to case-parent pairs. Discarding such data could lead to a severe loss of power. In this paper, we propose the HAP-1-TDT method based on case-parent pairs to detect haplotype/disease association. A permutation-based randomisation technique is devised to assess the significance of the test statistic. Furthermore, the combined statistic HAP-C-TDT is developed to use jointly case-parents trios and case-parent pairs. These test statistics can be applied to either phase-known or phase-unknown data. A number of simulation studies are conducted to investigate the validity of the proposed tests; these studies show that the statistics are robust to population structure. Using several disease genes from the literature, we illustrate that incorporating case-parent pairs into an association study leads to noticeable power gain. Moreover, our simulation results suggest that our method has better size and power than UNPHASED. Finally, in simulated scenarios where there are only a few SNPs and risk is determined by two haplotypes that are complementary or near-complementary, our method has better power than TRIMM. [source] | |||||||||||||