72 research outputs found

    A protein methylation pathway in Chlamydomonas flagella is active during flagellar resorption

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    Author Posting. © American Society for Cell Biology, 2008. This article is posted here by permission of American Society for Cell Biology for personal use, not for redistribution. The definitive version was published in Molecular Biology of the Cell 19 (2008): 4319-4327, doi:10.1091/mbc.E08-05-0470.During intraflagellar transport (IFT), the regulation of motor proteins, the loading and unloading of cargo and the turnover of flagellar proteins all occur at the flagellar tip. To begin an analysis of the protein composition of the flagellar tip, we used difference gel electrophoresis to compare long versus short (i.e., regenerating) flagella. The concentration of tip proteins should be higher relative to that of tubulin (which is constant per unit length of the flagellum) in short compared with long flagella. One protein we have identified is the cobalamin-independent form of methionine synthase (MetE). Antibodies to MetE label flagella in a punctate pattern reminiscent of IFT particle staining, and immunoblot analysis reveals that the amount of MetE in flagella is low in full-length flagella, increased in regenerating flagella, and highest in resorbing flagella. Four methylated proteins have been identified in resorbing flagella, using antibodies specific for asymmetrically dimethylated arginine residues. These proteins are found almost exclusively in the axonemal fraction, and the methylated forms of these proteins are essentially absent in full-length and regenerating flagella. Because most cells resorb cilia/flagella before cell division, these data indicate a link between flagellar protein methylation and progression through the cell cycle.This work was supported by National Institutes of Health Grant DK071720 (R.D.S.) and National Science Foundation Grant MCB 0418877 (R.D.S.)

    Sequelae due to bacterial meningitis among African children: a systematic literature review

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    <p>Abstract</p> <p>Background</p> <p>African children have some of the highest rates of bacterial meningitis in the world. Bacterial meningitis in Africa is associated with high case fatality and frequent neuropsychological sequelae. The objective of this study is to present a comprehensive review of data on bacterial meningitis sequelae in children from the African continent.</p> <p>Methods</p> <p>We conducted a systematic literature search to identify studies from Africa focusing on children aged between 1 month to 15 years with laboratory-confirmed bacterial meningitis. We extracted data on neuropsychological sequelae (hearing loss, vision loss, cognitive delay, speech/language disorder, behavioural problems, motor delay/impairment, and seizures) and mortality, by pathogen.</p> <p>Results</p> <p>A total of 37 articles were included in the final analysis representing 21 African countries and 6,029 children with confirmed meningitis. In these studies, nearly one fifth of bacterial meningitis survivors experienced in-hospital sequelae (median = 18%, interquartile range (IQR) = 13% to 27%). About a quarter of children surviving pneumococcal meningitis and <it>Haemophilus influenzae </it>type b (Hib) meningitis had neuropsychological sequelae by the time of hospital discharge, a risk higher than in meningococcal meningitis cases (median = 7%). The highest in-hospital case fatality ratios observed were for pneumococcal meningitis (median = 35%) and Hib meningitis (median = 25%) compared to meningococcal meningitis (median = 4%). The 10 post-discharge studies of children surviving bacterial meningitis were of varying quality. In these studies, 10% of children followed-up post discharge died (range = 0% to 18%) and a quarter of survivors had neuropsychological sequelae (range = 3% to 47%) during an average follow-up period of 3 to 60 months.</p> <p>Conclusion</p> <p>Bacterial meningitis in Africa is associated with high mortality and risk of neuropsychological sequelae. Pneumococcal and Hib meningitis kill approximately one third of affected children and cause clinically evident sequelae in a quarter of survivors prior to hospital discharge. The three leading causes of bacterial meningitis are vaccine preventable, and routine use of conjugate vaccines could provide substantial health and economic benefits through the prevention of childhood meningitis cases, deaths and disability.</p

    Analysis of gene expression in the nervous system identifies key genes and novel candidates for health and disease

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    The incidence of neurodegenerative diseases in the developed world has risen over the last century, concomitant with an increase in average human lifespan. A major challenge is therefore to identify genes that control neuronal health and viability with a view to enhancing neuronal health during ageing and reducing the burden of neurodegeneration. Analysis of gene expression data has recently been used to infer gene functions for a range of tissues from co-expression networks. We have now applied this approach to transcriptomic datasets from the mammalian nervous system available in the public domain. We have defined the genes critical for influencing neuronal health and disease in different neurological cell types and brain regions. The functional contribution of genes in each co-expression cluster was validated using human disease and knockout mouse phenotypes, pathways and gene ontology term annotation. Additionally a number of poorly annotated genes were implicated by this approach in nervous system function. Exploiting gene expression data available in the public domain allowed us to validate key nervous system genes and, importantly, to identify additional genes with minimal functional annotation but with the same expression pattern. These genes are thus novel candidates for a role in neurological health and disease and could now be further investigated to confirm their function and regulation during ageing and neurodegeneration. ELECTRONIC SUPPLEMENTARY MATERIAL: The online version of this article (doi:10.1007/s10048-017-0509-5) contains supplementary material, which is available to authorized users

    Wimp

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    Bacheloroppgave i Internasjonal Markedsføring fra University of Mannheim i Tyskland, 2014WiMP is a music streaming service that provides the user with customized music offerings. The company is established in several countries including Germany, which will be the focus of this thesis. The goal for this thesis is to figure out how WiMP can continue their growth in the German market, and gain a competitive advantage on their competitors. To reach this goal the group has gathered a large amount of information, conducted a survey and an analysis of the company both internal and external. This is summarized in a SWOT analysis. The group has used relevant theories and models throughout the thesis to explain the situation of WiMP. At the end, the group will provide a summary and a strategic recommendation for what measures the company should pursue in the future

    Analysis of radar sea clutter data acquired during the MARLENE measurement campaign

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    Maritime environment, and in particular the sea clutter, has a significant impact on the detection efficiency. Therefore the physical properties of the radar sea clutter must be well mastered. In this paper, we focus on sea clutter data acquired during an experiment called MARLENE, which was held in the Mediterranean Sea region of Toulon, France, in 2014. The aim of this experiment was to characterize the sea environment influence on radar propagation and backscattering for Refractivity From Clutter (RFC) and radar Doppler detection. Three coastal radars, MARSIG (WTD 71), MEMPHIS (FHR) and MEDYCIS (ONERA) were used to acquire sea clutter measurements simultaneously. During the radar measurements, the in-situ oceanic and meteorological conditions were characterized on board of the RV PLANET meteorological ship deployed by WTD 71 and by WAVEWATCH III and SWAN wave models. The paper gives an overview of the MARLENE experiment, presents the radar data and the first results on sea clutter reflectivity and Doppler
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