237 research outputs found

    Rank 3 permutation characters and maximal subgroups

    Full text link
    In this paper we classify all maximal subgroups M of a nearly simple primitive rank 3 group G of type L=Omega_{2m+1}(3), m > 3; acting on an L-orbit E of non-singular points of the natural module for L such that 1_P^G <=1_M^G where P is a stabilizer of a point in E. This result has an application to the study of minimal genera of algebraic curves which admit group actions.Comment: 41 pages, to appear in Forum Mathematicu

    On two theorems for flat, affine group schemes over a discrete valuation ring

    Full text link
    We include short and elementary proofs of two theorems characterizing reductive group schemes over a discrete valuation ring, in a slightly more general context.Comment: 10 pages. To appear in C. E. J.

    Opinion leaders and changes over time: a survey

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Opinion leaders represent one way to disseminate new knowledge and influence the practice behaviors of physicians. This study explored the stability of opinion leaders over time, whether opinion leaders were polymorphic (<it>i.e.</it>, influencing multiple practice areas) or monomorphic (<it>i.e.</it>, influencing one practice area), and reach of opinion leaders in their local network.</p> <p>Methods</p> <p>We surveyed surgeons and pathologists in Ontario to identify opinion leaders for colorectal cancer in 2003 and 2005 and to identify opinion leaders for breast cancer in 2005. We explored whether opinion leaders for colorectal cancer identified in 2003 were re-identified in 2005. We examined whether opinion leaders were considered polymorphic (nominated in 2005 as opinion leaders for both colorectal and breast cancer) or monomorphic (nominated in 2005 for only one condition). Social-network mapping was used to identify the number of local colleagues identifying opinion leaders.</p> <p>Results</p> <p>Response rates for surgeons were 41% (2003) and 40% (2005); response rates for pathologists were 42% (2003) and 37% (2005). Four (25%) of the surgical opinion leaders identified in 2003 for colorectal cancer were re-identified in 2005. No pathology opinion leaders for colorectal cancer were identified in both 2003 and 2005. Only 29% of surgical opinion leaders and 17% of pathology opinion leaders identified in the 2005 survey were considered influential for both colorectal cancer and breast cancer. Social-network mapping revealed that only a limited number of general surgeons (12%) or pathologists (7%) were connected to the social networks of identified opinion leaders.</p> <p>Conclusions</p> <p>Opinion leaders identified in this study were not stable over a two-year time period and generally appear to be monomorphic, with clearly demarcated areas of expertise and limited spheres of influence. These findings may limit the practicability of routinely using opinion leaders to influence practice.</p

    Quality improvement in small office settings: an examination of successful practices

    Get PDF
    <p>Abstract</p> <p>Background</p> <p>Physicians in small to moderate primary care practices in the United States (U.S.) (<25 physicians) face unique challenges in implementing quality improvement (QI) initiatives, including limited resources, small staffs, and inadequate information technology systems 23,36. This qualitative study sought to identify and understand the characteristics and organizational cultures of physicians working in smaller practices who are actively engaged in measurement and quality improvement initiatives.</p> <p>Methods</p> <p>We undertook a qualitative study, based on semi-structured, open-ended interviews conducted with practices (N = 39) that used performance data to drive quality improvement activities.</p> <p>Results</p> <p>Physicians indicated that benefits to performing measurement and QI included greater practice efficiency, patient and staff retention, and higher staff and clinician satisfaction with practice. Internal facilitators included the designation of a practice champion, cooperation of other physicians and staff, and the involvement of practice leaders. Time constraints, cost of activities, problems with information management and or technology, lack of motivated staff, and a lack of financial incentives were commonly reported as barriers.</p> <p>Conclusion</p> <p>These findings shed light on how physicians engage in quality improvement activities, and may help raise awareness of and aid in the implementation of future initiatives in small practices more generally.</p

    The heart in sporadic inclusion body myositis: a study in 51 patients

    Get PDF
    The purpose of this study was to explore the prevalence and nature of cardiac abnormalities in sporadic inclusion body myositis (sIBM). Fifty-one sIBM patients were cross-sectionally studied using history-taking, physical examination, measurements of serum creatine kinase activity, the MB fraction (CK-MB), cardiac troponin T (cTnT) and I (cTnI), a 12-lead electrocardiogram (ECG) and 2-dimensional echocardiography. Present cardiac history was abnormal in 12 (24%) out of 51 patients, 12 (24%) patients had abnormalities on ECG, mostly aspecific, and in 12 (24%) patients the echocardiograph showed abnormalities. Elevated CK-MB was present in 42 (82%) patients and 40 (78%) had an elevated cTnT in the absence of acute cardiac pathology. In contrast, in one patient (2%) cTnI was elevated. There was no apparent association between elevated biomarkers, ECG or echocardiographic abnormalities. The prevalence of cardiac abnormalities in sIBM does not seem to be higher than would be expected in these elderly patients. Elevated CK-MB and cTnT levels are common, in contrast to cTnI, but do not reflect cardiac pathology

    Stone Age Yersinia pestis genomes shed light on the early evolution, diversity, and ecology of plague

    Get PDF
    The bacterial pathogenYersinia pestisgave rise to devastating outbreaks throughouthuman history, and ancient DNA evidence has shown it afflicted human populations asfar back as the Neolithic.Y. pestisgenomes recovered from the Eurasian Late Neolithic/Early Bronze Age (LNBA) period have uncovered key evolutionary steps that led to itsemergence from aYersinia pseudotuberculosis-like progenitor; however, the number ofreconstructed LNBA genomes are too few to explore its diversity during this criticalperiod of development. Here, we present 17Y. pestisgenomes dating to 5,000 to 2,500y BP from a wide geographic expanse across Eurasia. This increased dataset enabled usto explore correlations between temporal, geographical, and genetic distance. Ourresults suggest a nonflea-adapted and potentially extinct single lineage that persistedover millennia without significant parallel diversification, accompanied by rapid dis-persal across continents throughout this period, a trend not observed in other pathogensfor which ancient genomes are available. A stepwise pattern of gene loss provides fur-ther clues on its early evolution and potential adaptation. We also discover the presenceof theflea-adapted form ofY. pestisin Bronze Age Iberia, previously only identified inin the Caucasus and the Volga regions, suggesting a much wider geographic spread ofthis form ofY. pestis. Together, these data reveal the dynamic nature of plague’s forma-tive years in terms of its early evolution and ecology
    corecore