121 research outputs found

    Survey on functionally diverse bacterial strains from marine finfishes and crustaceans

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    Prokaryotic microorganisms compromise a large portion of the organic biomass of the world’s ocean and play an important role in the biogeochemical cycles and food webs of this ecosystem. Surface colonization by microorganisms is ubiquitous in marine systems with a large proportion of microbes occurring as complex communities. Despite their importance, comparatively little is known about the phylogenetic composition of this complex microbial population and the functional roles of their members. Living surfaces are ideal to explore colonization by microorganisms because eukaryotes are subject to a constant bombardment from the millions of microbial cells typically found in a millilitre of seawater

    An Agent-Based Model to study the epidemiological and evolutionary dynamics of Influenza viruses

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    <p>Abstract</p> <p>Background</p> <p>Influenza A viruses exhibit complex epidemiological patterns in a number of mammalian and avian hosts. Understanding transmission of these viruses necessitates taking into account their evolution, which represents a challenge for developing mathematical models. This is because the phrasing of multi-strain systems in terms of traditional compartmental ODE models either requires simplifying assumptions to be made that overlook important evolutionary processes, or leads to complex dynamical systems that are too cumbersome to analyse.</p> <p>Results</p> <p>Here, we develop an Individual-Based Model (IBM) in order to address simultaneously the ecology, epidemiology and evolution of strain-polymorphic pathogens, using Influenza A viruses as an illustrative example.</p> <p>Conclusions</p> <p>We carry out careful validation of our IBM against comparable mathematical models to demonstrate the robustness of our algorithm and the sound basis for this novel framework. We discuss how this new approach can give critical insights in the study of influenza evolution.</p

    FGF receptor genes and breast cancer susceptibility: results from the Breast Cancer Association Consortium

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    Background:Breast cancer is one of the most common malignancies in women. Genome-wide association studies have identified FGFR2 as a breast cancer susceptibility gene. Common variation in other fibroblast growth factor (FGF) receptors might also modify risk. We tested this hypothesis by studying genotyped single-nucleotide polymorphisms (SNPs) and imputed SNPs in FGFR1, FGFR3, FGFR4 and FGFRL1 in the Breast Cancer Association Consortium. Methods:Data were combined from 49 studies, including 53 835 cases and 50 156 controls, of which 89 050 (46 450 cases and 42 600 controls) were of European ancestry, 12 893 (6269 cases and 6624 controls) of Asian and 2048 (1116 cases and 932 controls) of African ancestry. Associations with risk of breast cancer, overall and by disease sub-type, were assessed using unconditional logistic regression. Results:Little evidence of association with breast cancer risk was observed for SNPs in the FGF receptor genes. The strongest evidence in European women was for rs743682 in FGFR3; the estimated per-allele odds ratio was 1.05 (95 confidence interval=1.02-1.09, P=0.0020), which is substantially lower than that observed for SNPs in FGFR2. Conclusion:Our results suggest that common variants in the other FGF receptors are not associated with risk of breast cancer to the degree observed for FGFR2. © 2014 Cancer Research UK

    Transmission of Avian Influenza A Viruses among Species in an Artificial Barnyard

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    Waterfowl and shorebirds harbor and shed all hemagglutinin and neuraminidase subtypes of influenza A viruses and interact in nature with a broad range of other avian and mammalian species to which they might transmit such viruses. Estimating the efficiency and importance of such cross-species transmission using epidemiological approaches is difficult. We therefore addressed this question by studying transmission of low pathogenic H5 and H7 viruses from infected ducks to other common animals in a quasi-natural laboratory environment designed to mimic a common barnyard. Mallards (Anas platyrhynchos) recently infected with H5N2 or H7N3 viruses were introduced into a room housing other mallards plus chickens, blackbirds, rats and pigeons, and transmission was assessed by monitoring virus shedding (ducks) or seroconversion (other species) over the following 4 weeks. Additional animals of each species were directly inoculated with virus to characterize the effect of a known exposure. In both barnyard experiments, virus accumulated to high titers in the shared water pool. The H5N2 virus was transmitted from infected ducks to other ducks and chickens in the room either directly or through environmental contamination, but not to rats or blackbirds. Ducks infected with the H7N2 virus transmitted directly or indirectly to all other species present. Chickens and blackbirds directly inoculated with these viruses shed significant amounts of virus and seroconverted; rats and pigeons developed antiviral antibodies, but, except for one pigeon, failed to shed virus

    Phenol removal from aqueous systems by sorption on jackwood sawdust

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    137-141<span style="font-size:11.0pt;line-height: 115%;font-family:Calibri;mso-fareast-font-family:" times="" new="" roman";mso-bidi-font-family:="" "times="" roman";mso-ansi-language:en-us;mso-fareast-language:en-us;="" mso-bidi-language:ar-sa"="" lang="EN-US">The adsorption technique using sawdust of jackwood timber has been applied for the removal of phenol from aqueous solutions. The extent of removal was dependant on concentration, pH and temperature of the solution. With an initial concentration of 25 mg/L at 30°C and pH 7, the removal was found to be 62.5% by using sawdust as adsorbent. The time to reach equilibrium was found to be 6 h. The higher uptake of 79.2% of the initial concentration of 25 mg/L occurs at pH 5.5 at 30°C. The applicability of Freundlich isotherm to the sawdust-phenol system was tested at 10, 20 and 30°C at pH 5.5, which can be used for the design of wastewater treatment plants. The spent adsorbent can be regenerated and reused by acid treatment.</span

    Hydrogeochemistry and Groundwater Quality of Coastal Aquifers of Alappad Region Kollam Kerala India

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