1,178 research outputs found

    A cautionary note on the appropriateness of using a linkage resource for an association study

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    BACKGROUND: Utilizing a linkage resource for association analysis requires consideration both of the marker data used and correlations among relatives in pedigrees. We previously developed a method for association testing in pedigrees. We applied our method to 50 replicates of microsatellite data surrounding five genes involved in high-density lipoprotein (HDL) in the Genetic Analysis Workshop 13 (GAW13) simulated data and examined association with HDL as well as linkage disequilibrium (LD) between markers. RESULTS: Although no association was intentionally simulated, we found significant evidence of weak LD between microsatellite markers (flanking/~5 cM from the genes), in some but not all replicates. This level of LD compared well to that observed in the real GAW13 Framingham data. Only one region had sufficient replicates to assess power, and this was low (12.5–20.8%). More power was attained using all individuals and accounting for relationships, compared with one independent individual/pedigree, although this was not significant due to small sample sizes. Not accounting for relatedness inflated statistical significance (p < 0.0001). CONCLUSION: A correction for dependence is necessary in association studies to avoid an inflation of significance probabilities. Our results further illustrate that use of microsatellite marker data is not an effective approach for association testing

    No evidence of BRCA2 mutations in chromosome 13q-linked Utah high-risk prostate cancer pedigrees

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    <p>Abstract</p> <p>Background</p> <p>Germline mutations in the <it>BRCA2 </it>gene have been suggested to account for about 5% of familial prostate cancer; mutations have been reported in 2% of early onset (i.e., ≀ 55 years) prostate cancer cases and a segregating founder mutation has been identified in Iceland (999del5). However, the role of <it>BRCA2 </it>in high risk prostate cancer pedigrees remains unclear.</p> <p>Findings</p> <p>We examined the potential involvement of <it>BRCA2 </it>in a set offive high-risk prostate cancer pedigrees in which all prostate cases were no more distantly related than two meioses from another case, and the resulting cluster contained at least four prostate cancer cases. We selected these five pedigrees from a larger dataset of 59 high-risk prostate cancer pedigrees analyzed in a genome-wide linkage screen. Selected pedigrees showed at least nominal linkage evidence to the <it>BRCA2 </it>region on chromosome 13q. We mutation screened all coding regions and intron/exon boundaries of the <it>BRCA2 </it>gene in the youngest prostate cancer case who carried the linked 13q segregating haplotype, as well as in a distantly related haplotype carrier to confirm any segregation. We observed no known protein truncating <it>BRCA2 </it>deleterious mutations. We identified one non-segregating <it>BRCA2 </it>variant of uncertain significance, one non-segregating intronic variant not previously reported, and a number of polymorphisms.</p> <p>Conclusion</p> <p>In this set of high-risk prostate cancer pedigrees with at least nominal linkage evidence to <it>BRCA2</it>, we saw no evidence for segregating <it>BRCA2 </it>protein truncating mutations in heritable prostate cancer.</p

    Hedonic and Utilitarian Value and Patient Satisfaction: Perceptual Differences between Patients and Providers

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    Healthcare is continually evolving to meet changing governmental regulations and a new emphasis on patient perceptions of quality care. Governmental mandates create a shift in focus from volume-based to value-based reimbursement for providers. The purpose of this article is to identify satisfaction drivers with particular emphasis on similarities and differences between the perceptions of hospital patients and providers. A combination of quality-based healthcare, stakeholder theory, and services literature points to key service outcomes including expectations, quality, value, and satisfaction. Multiple group structural equations modeling provides a vehicle for examining differences in relationships among these constructs between these two key stakeholders, patients and providers. Results suggest that utilitarian value is central to successful healthcare service experiences. But, the results also suggest differences between patients and providers in the way they believe utilitarian value affects outcomes; the results suggest that healthcare providers may underestimate utilitarian value’s role relative to patient perceptions

    Self-assembly and adsorption of cetyltrimethylammonium bromide and didodecyldimethylammonium bromide surfactants at the mica-water interface

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    The self-assembly and adsorption of the surfactants cetyltrimethylammonium bromide (CTAB) and didodecyldimethylammonium bromide (DDAB) at the muscovite mica-water interface are studied using molecular-dynamics simulations. Adsorption takes place by an ion-exchange mechanism, in which K+ ions are replaced by the organic alkylammonium cations from the solution. Simulations are performed with and without the surface K+ ions, with pure water, and with the surfactants in aqueous solution. CTAB and DDAB form micellar structures in bulk solution, and in the absence of the surface K+ ions, they quickly adsorb and form bilayer structures. The bilayer ordering of CTAB is not perfect, and there is a competition with the formation of cylindrical micelles. DDAB, on the other hand, forms a well-ordered bilayer structure, with the innermost layer showing strong orientational ordering, and the outermost layer being more disordered. The simulations with pure water highlight the molecular ordering and strong electrostatic interactions with the mica-surface atoms. Using simulated scattering length density profiles, the results are compared directly and critically with existing neutron reflectivity measurements. The simulation results are generally consistent with experiments, and yield new insights on the molecular-scale ordering at the mica-water interface.G. T. was supported by a PhD studentship from BP Castrol [Research Agreement GPTL/92534(2)]. Access to the BP High Performance Computing Facility in Houston, Texas is gratefully acknowledged. F. J. A. was supported by EPSRC and BP plc (RG8620)

    LMDA Review, volume 10, issue 1

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    Contents include: Photo of Conference Participants Annual Conference 1999, Send in your Ballot, A Note to Ourselves, Increase in Dues and New Annual Membership Expiration Date, LMDA Archive, LMDA Administrator; LMDA Interns, Mid-Year Meeting, Early Career Dramaturg Program, Elliot Hayes Award 2000, Report on Canadian Caucus, Script Exchange, Report on the Dramaturgy Focus Group ATHE 1999, Elliot Hayes Award Winners Lue Douthit and Michel Volansky, Acceptance Speech Lue Morgan Douthit, Elliot Hayes Award Presentation to Michele Volansky for Space, On the Elliot Hayes Award Michele Volansky, Day One of the Conference, Day Two of the Conference, Day Three of the Conference, Day Four of the Conference, The Advocacy Caucus Presentation at the Conference, Final Thoughts, Conference 1999 Many Thanks, Arthur Ballet and the Office for Advanced Drama Research, Spotlight on Early Career Dramaturg Vanessa Porteous, A Working History of LMDA The Early Years, From Academia to Arena A Dramaturg\u27s Education in the Real World, Tony Creamer and Death of a Salesman, Two Moments, Jobs and Projects, Scriptseeker.com, LMDA Online Listserv Instructions, Note from James Magruder, Literary Managers and Dramaturgs of the Americas Bibliography 1999, Noted with Pleasure, and Internship Questionnaire.https://soundideas.pugetsound.edu/lmdareview/1020/thumbnail.jp

    Meta-analysis of genome-wide association studies of asthma in ethnically diverse North American populations.

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    Asthma is a common disease with a complex risk architecture including both genetic and environmental factors. We performed a meta-analysis of North American genome-wide association studies of asthma in 5,416 individuals with asthma (cases) including individuals of European American, African American or African Caribbean, and Latino ancestry, with replication in an additional 12,649 individuals from the same ethnic groups. We identified five susceptibility loci. Four were at previously reported loci on 17q21, near IL1RL1, TSLP and IL33, but we report for the first time, to our knowledge, that these loci are associated with asthma risk in three ethnic groups. In addition, we identified a new asthma susceptibility locus at PYHIN1, with the association being specific to individuals of African descent (P = 3.9 × 10(-9)). These results suggest that some asthma susceptibility loci are robust to differences in ancestry when sufficiently large samples sizes are investigated, and that ancestry-specific associations also contribute to the complex genetic architecture of asthma

    Swift follow-up observations of candidate gravitational-wave transient events

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    We present the first multi-wavelength follow-up observations of two candidate gravitational-wave (GW) transient events recorded by LIGO and Virgo in their 2009-2010 science run. The events were selected with low latency by the network of GW detectors and their candidate sky locations were observed by the Swift observatory. Image transient detection was used to analyze the collected electromagnetic data, which were found to be consistent with background. Off-line analysis of the GW data alone has also established that the selected GW events show no evidence of an astrophysical origin; one of them is consistent with background and the other one was a test, part of a "blind injection challenge". With this work we demonstrate the feasibility of rapid follow-ups of GW transients and establish the sensitivity improvement joint electromagnetic and GW observations could bring. This is a first step toward an electromagnetic follow-up program in the regime of routine detections with the advanced GW instruments expected within this decade. In that regime multi-wavelength observations will play a significant role in completing the astrophysical identification of GW sources. We present the methods and results from this first combined analysis and discuss its implications in terms of sensitivity for the present and future instruments.Comment: Submitted for publication 2012 May 25, accepted 2012 October 25, published 2012 November 21, in ApJS, 203, 28 ( http://stacks.iop.org/0067-0049/203/28 ); 14 pages, 3 figures, 6 tables; LIGO-P1100038; Science summary at http://www.ligo.org/science/Publication-S6LVSwift/index.php ; Public access area to figures, tables at https://dcc.ligo.org/cgi-bin/DocDB/ShowDocument?docid=p110003
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