1,318 research outputs found

    B cells contribute to MS pathogenesis through antibody-dependent and antibody-independent mechanisms

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    For many years, central dogma defined multiple sclerosis (MS) as a T cell-driven autoimmune disorder; however, over the past decade there has been a burgeoning recognition that B cells contribute to the pathogenesis of certain MS disease subtypes. B cells may contribute to MS pathogenesis through production of autoantibodies (or antibodies directed at foreign bodies, which unfortunately cross-react with self-antigens), through promotion of T cell activation via antigen presentation, or through production of cytokines. This review highlights evidence for antibody-dependent and antibody-independent B cell involvement in MS pathogenesis

    Songs of the Brokenhearted: On the Possibility of Cultivating a National Music Collection in the Iraq National Library and Archive

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    Iraq's musical history is as old as civilization. Libraries have also been part of Iraq for centuries, yet these institutions have rarely collected music materials. After the 2003 destruction of most Iraqi libraries, librarians have been seeking support for reviving these libraries, developing a national music collection in the Iraq National Library and Archive (INLA) is necessary. This paper proposes that this collection be created, and it seeks to answer two concerns. The first, "How can this music collection be developed?," is answered by reviewing literature from scholars of like collections; by looking at the music collecting policies of similar libraries; and by identifying materials to include in this collection. The second, "Is this music collection needed?," is answered by looking at how this collection will help fulfill other INLA goals. This paper will show that a national music collection is an essential addition to the INLA

    Population Dynamics of Long-tailed Ducks Breeding on the Yukon-Kuskokwim Delta, Alaska

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    Population estimates for long-tailed ducks in North America have declined by nearly 50% over the past 30 years. Life history and population dynamics of this species are difficult to ascertain, because the birds nest at low densities across a broad range of habitat types. Between 1991 and 2004, we collected information on productivity and survival of long-tailed ducks at three locations on the Yukon-Kuskokwim Delta. Clutch size averaged 7.1 eggs, and nesting success averaged 30%. Duckling survival to 30 days old averaged 10% but was highly variable among years, ranging from 0% to 25%. Apparent annual survival of adult females based on mark-recapture of nesting females was estimated at 74%. We combined these estimates of survival and productivity into a matrix-based population model, which predicted an annual population decline of 19%. Elasticities indicated that population growth rate (?) was most sensitive to changes in adult female survival. Further, the relatively high sensitivity of ? to duckling survival suggests that low duckling survival may be a bottleneck to productivity in some years. These data represent the first attempt to synthesize a population model for this species. Although our analyses were hampered by the small sample sizes inherent in studying a dispersed nesting species, our model provides a basis for management actions and can be enhanced as additional data become available.Les estimations de populations d’hareldes kakawis en Amérique du Nord ont chuté de près de 50 pour cent ces 30 dernières années. Le cycle biologique et la dynamique des populations de cette espèce sont difficiles à établir car ces oiseaux nichent moyennant de faibles densités dans une vaste gamme d’habitats. De 1991 à 2004, nous avons recueilli des données sur la productivité et la survie des hareldes kakawis à trois emplacements du delta Yukon-Kuskokwim. Les couvées atteignaient 7,1 oeufs en moyenne, tandis que le succès de reproduction s’établissait généralement à 30 pour cent. En moyenne, 10 pour cent des jeunes canards survivaient jusqu’à l’âge de 30 jours, mais ce taux variait beaucoup d’une année à l’autre, allant de 0 pour cent à 25 pour cent. Annuellement, d’après la méthode par marquage et recapture des femelles nidificatrices, la survie apparente des femelles adultes était évaluée à 74 pour cent. Nous avons combiné ces estimations de survie et de productivité dans un modèle de population matriciel, ce qui a permis de prédire un déclin de population annuel de 19 pour cent. Selon les élasticités, le taux de croissance de la population (?) était plus sensible aux changements dans le cas de la survie des femelles adultes. Par ailleurs, la sensibilité relativement élevée du ? par rapport à la survie des jeunes canards laisse croire que le faible taux de survie des jeunes canards pourrait présenter une embûche en matière de productivité d’ici quelques années. Ces données représentent la première tentative de synthèse d’un modèle de population pour cette espèce. Bien que nos analyses aient été gênées par la petite taille des échantillons inhérente à l’étude d’espèces de nidification dispersées, notre modèle fournit un fondement permettant d’aboutir à des mesures de gestion en plus de présenter la possibilité d’être amélioré au fur et à mesure que des données supplémentaires sont disponibles

    454-Pyrosequencing: A Molecular Battiscope for Freshwater Viral Ecology

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    Viruses, the most abundant biological entities on the planet, are capable of infecting organisms from all three branches of life, although the majority infect bacteria where the greatest degree of cellular diversity lies. However, the characterization and assessment of viral diversity in natural environments is only beginning to become a possibility. Through the development of a novel technique for the harvest of viral DNA and the application of 454 pyrosequencing, a snapshot of the diversity of the DNA viruses harvested from a standing pond on a cattle farm has been obtained. A high abundance of viral genotypes (785) were present within the virome. The absolute numbers of lambdoid and Shiga toxin (Stx) encoding phages detected suggested that the depth of sequencing had enabled recovery of only ca. 8% of the total virus population, numbers that agreed within less than an order of magnitude with predictions made by rarefaction analysis. The most abundant viral genotypes in the pond were bacteriophages (93.7%). The predominant viral genotypes infecting higher life forms found in association with the farm were pathogens that cause disease in cattle and humans, e.g. members of the Herpesviridae. The techniques and analysis described here provide a fresh approach to the monitoring of viral populations in the aquatic environment, with the potential to become integral to the development of risk analysis tools for monitoring the dissemination of viral agents of animal, plant and human diseases

    Documenting Support for Ongoing and Improved Efforts in Sexuality Education

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    As debate regarding sexuality education continues, STD, HIV, and teen pregnancy rates remain high. Garnering support is critical to ensure quality programs addressing these public health concerns. As part of a funded project to reduce adolescent sexual health issues in a large Florida county, this study assessed voter support for specific sexuality education topics. A survey was developed after reviewing existing instruments. The university’s Public Opinion Research Laboratory used random-digit-dialing to administer the survey (N=311). Most participants supported topics taught in middle school: dealing with pressure to have sex (85%), talking to parents about sex (90%), human anatomy/reproduction (91%), HIV/STDs (92%), abstinence (93%), birth control (83%), and condom use (81%). Support was even greater in high school (88%-97%) for these topics. Most participants (86%) supported teaching both abstinence and birth control/safer sex practices. Chi-square results showed significant differences in support of topics by several demographics. Results add substantial support for age-appropriate, school-based sexuality education and policy to support evidence-based abstinence-plus or comprehensive sexuality education. Documented support is important in establishing, changing, and ensuring ongoing policy. Such findings can both encourage and support administrators and teachers in offering evidence-based sexuality education programs

    Using e-mail recruitment and an online questionnaire to establish effect size: A worked example

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    Background\ud Sample size calculations require effect size estimations. Sometimes, effect size estimations and standard deviation may not be readily available, particularly if efficacy is unknown because the intervention is new or developing, or the trial targets a new population. In such cases, one way to estimate the effect size is to gather expert opinion. This paper reports the use of a simple strategy to gather expert opinion to estimate a suitable effect size to use in a sample size calculation.\ud \ud Methods\ud Researchers involved in the design and analysis of clinical trials were identified at the University of Birmingham and via the MRC Hubs for Trials Methodology Research. An email invited them to participate.\ud \ud An online questionnaire was developed using the free online tool 'Survey Monkey©'. The questionnaire described an intervention, an electronic participant information sheet (e-PIS), which may increase recruitment rates to a trial. Respondents were asked how much they would need to see recruitment rates increased by, based on 90%. 70%, 50% and 30% baseline rates, (in a hypothetical study) before they would consider using an e-PIS in their research.\ud \ud Analyses comprised simple descriptive statistics.\ud \ud Results\ud The invitation to participate was sent to 122 people; 7 responded to say they were not involved in trial design and could not complete the questionnaire, 64 attempted it, 26 failed to complete it. Thirty-eight people completed the questionnaire and were included in the analysis (response rate 33%; 38/115). Of those who completed the questionnaire 44.7% (17/38) were at the academic grade of research fellow 26.3% (10/38) senior research fellow, and 28.9% (11/38) professor. Dependent upon the baseline recruitment rates presented in the questionnaire, participants wanted recruitment rate to increase from 6.9% to 28.9% before they would consider using the intervention.\ud \ud Conclusions\ud This paper has shown that in situations where effect size estimations cannot be collected from previous research, opinions from researchers and trialists can be quickly and easily collected by conducting a simple study using email recruitment and an online questionnaire. The results collected from the survey were successfully used in sample size calculations for a PhD research study protocol.\ud \u

    Mo\u3csup\u3eV\u3c/sup\u3e Electron Paramagnetic Resonance of Sulfite Oxidase Revisited: The Low-pH Chloride Signal

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    Valuable information on the active sites of molybdenum enzymes has been provided by MoV electron paramagnetic resonance (EPR) spectroscopy. In recent years, multiple resonance techniques have been extensively used to examine details of the active-site structure, but basic continuous-wave (CW) EPR has not been re-evaluated in several decades. Here, we present a re-examination of the CW EPR spectroscopy of the sulfite oxidase low-pH chloride species and provide evidence for direct coordination of molybdenum by chloride

    Can screening and brief intervention lead to population-level reductions in alcohol-related harm?

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    A distinction is made between the clinical and public health justifications for screening and brief intervention (SBI) against hazardous and harmful alcohol consumption. Early claims for a public health benefit of SBI derived from research on general medical practitioners' (GPs') advice on smoking cessation, but these claims have not been realized, mainly because GPs have not incorporated SBI into their routine practice. A recent modeling exercise estimated that, if all GPs in England screened every patient at their next consultation, 96% of the general population would be screened over 10 years, with 70-79% of excessive drinkers receiving brief interventions (BI); assuming a 10% success rate, this would probably amount to a population-level effect of SBI. Thus, a public health benefit for SBI presupposes widespread screening; but recent government policy in England favors targeted versus universal screening, and in Scotland screening is based on new registrations and clinical presentation. A recent proposal for a national screening program was rejected by the UK National Health Service's National Screening Committee because 1) there was no good evidence that SBI led to reductions in mortality or morbidity, and 2) a safe, simple, precise, and validated screening test was not available. Even in countries like Sweden and Finland, where expensive national programs to disseminate SBI have been implemented, only a minority of the population has been asked about drinking during health-care visits, and a minority of excessive drinkers has been advised to cut down. Although there has been research on the relationship between treatment for alcohol problems and population-level effects, there has been no such research for SBI, nor have there been experimental investigations of its relationship with population-level measures of alcohol-related harm. These are strongly recommended. In this article, conditions that would allow a population-level effect of SBI to occur are reviewed, including their political acceptability. It is tentatively concluded that widespread dissemination of SBI, without the implementation of alcohol control measures, might have indirect influences on levels of consumption and harm but would be unlikely on its own to result in public health benefits. However, if and when alcohol control measures were introduced, SBI would still have an important role in the battle against alcohol-related harm
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