563 research outputs found

    Evidence for Nodal Superconductivity in LaFePO from Scanning SQUID Susceptometry

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    We measure changes in the penetration depth λ\lambda of the Tc6T_c \approx 6 K superconductor LaFePO. In the process scanning SQUID susceptometry is demonstrated as a technique for accurately measuring {\it local} temperature-dependent changes in λ\lambda, making it ideal for studying early or difficult-to-grow materials. λ\lambda of LaFePO is found to vary linearly with temperature from 0.36 to \sim2 K, with a slope of 143±\pm15 \AA/K, suggesting line nodes in the superconducting order parameter. The linear dependence up to Tc/3\sim T_c/3 is similar to the cuprate superconductors, indicating well-developed nodes.Comment: 4 pages, 5 figure

    Perceptions of Women and Men Leaders Following 360‐Degree Feedback Evaluations

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    In this study, researchers used a customized 360‐degree method to examine the frequency with which 1,546 men and 721 women leaders perceived themselves and were perceived by colleagues as using 10 relational and 10 task‐oriented leadership behaviors, as addressed in the Management‐Leadership Practices Inventory (MLPI). As hypothesized, men and women leaders, as well as their supervisors, employees, and peers, perceived women leaders to employ nine of the 10 relational leadership behaviors significantly more frequently than men leaders. Additionally, the employees' perceptions of their women leaders' use of task‐oriented behaviors were significantly higher when compared to similar assessments from the employees of men leaders. However, the leaders as well as their supervisors and peers perceived men and women leaders' use of task‐oriented behaviors as approximately equal. Broader implications of these findings are discussed.Peer Reviewedhttp://deepblue.lib.umich.edu/bitstream/2027.42/97470/1/21134_ftp.pd

    Clinicopathological evaluation of chronic traumatic encephalopathy in players of American football

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    IMPORTANCE: Players of American football may be at increased risk of long-term neurological conditions, particularly chronic traumatic encephalopathy (CTE). OBJECTIVE: To determine the neuropathological and clinical features of deceased football players with CTE. DESIGN, SETTING, AND PARTICIPANTS: Case series of 202 football players whose brains were donated for research. Neuropathological evaluations and retrospective telephone clinical assessments (including head trauma history) with informants were performed blinded. Online questionnaires ascertained athletic and military history. EXPOSURES: Participation in American football at any level of play. MAIN OUTCOMES AND MEASURES: Neuropathological diagnoses of neurodegenerative diseases, including CTE, based on defined diagnostic criteria; CTE neuropathological severity (stages I to IV or dichotomized into mild [stages I and II] and severe [stages III and IV]); informant-reported athletic history and, for players who died in 2014 or later, clinical presentation, including behavior, mood, and cognitive symptoms and dementia. RESULTS: Among 202 deceased former football players (median age at death, 66 years [interquartile range, 47-76 years]), CTE was neuropathologically diagnosed in 177 players (87%; median age at death, 67 years [interquartile range, 52-77 years]; mean years of football participation, 15.1 [SD, 5.2]), including 0 of 2 pre–high school, 3 of 14 high school (21%), 48 of 53 college (91%), 9 of 14 semiprofessional (64%), 7 of 8 Canadian Football League (88%), and 110 of 111 National Football League (99%) players. Neuropathological severity of CTE was distributed across the highest level of play, with all 3 former high school players having mild pathology and the majority of former college (27 [56%]), semiprofessional (5 [56%]), and professional (101 [86%]) players having severe pathology. Among 27 participants with mild CTE pathology, 26 (96%) had behavioral or mood symptoms or both, 23 (85%) had cognitive symptoms, and 9 (33%) had signs of dementia. Among 84 participants with severe CTE pathology, 75 (89%) had behavioral or mood symptoms or both, 80 (95%) had cognitive symptoms, and 71 (85%) had signs of dementia. CONCLUSIONS AND RELEVANCE: In a convenience sample of deceased football players who donated their brains for research, a high proportion had neuropathological evidence of CTE, suggesting that CTE may be related to prior participation in football.This study received support from NINDS (grants U01 NS086659, R01 NS078337, R56 NS078337, U01 NS093334, and F32 NS096803), the National Institute on Aging (grants K23 AG046377, P30AG13846 and supplement 0572063345-5, R01 AG1649), the US Department of Defense (grant W81XWH-13-2-0064), the US Department of Veterans Affairs (I01 CX001038), the Veterans Affairs Biorepository (CSP 501), the Veterans Affairs Rehabilitation Research and Development Traumatic Brain Injury Center of Excellence (grant B6796-C), the Department of Defense Peer Reviewed Alzheimer’s Research Program (grant 13267017), the National Operating Committee on Standards for Athletic Equipment, the Alzheimer’s Association (grants NIRG-15-362697 and NIRG-305779), the Concussion Legacy Foundation, the Andlinger Family Foundation, the WWE, and the NFL

    Incident vertebral fractures and risk factors in the first three years following glucocorticoid initiation among pediatric patients with rheumatic disorders

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    Vertebral fractures are an important yet underrecognized manifestation of osteoporosis in children with chronic, glucocorticoid-treated illnesses. Our goal was to determine the incidence and clinical predictors of vertebral fractures in the 3 years following glucocorticoid initiation among pediatric patients with rheumatic disorders. Incident vertebral fractures were evaluated according to the Genant semiquantitative method on lateral radiographs at baseline and then annually in the 3 years following glucocorticoid initiation. Extended Cox models were used to assess the association between vertebral fractures and clinical risk predictors. A total of 134 children with rheumatic disorders were enrolled in the study (mean ± standard deviation (SD) age 9.9 ± 4.4 years; 65% girls). The unadjusted vertebral fracture incidence rate was 4.4 per 100 person-years, with a 3-year incidence proportion of 12.4%. The highest annual incidence occurred in the first year (6.0%; 95% confidence interval (CI) 2.9% to 11.7%). Almost one-half of the patients with fractures were asymptomatic. Every 0.5 mg/kg increase in average daily glucocorticoid (prednisone equivalents) dose was associated with a twofold increased fracture risk (hazard ratio (HR) 2.0; 95% CI 1.1 to 3.5). Other predictors of increased vertebral fracture risk included: (1) increases in disease severity scores between baseline and 12 months; (2) increases in body mass index Z-scores in the first 6 months of each 12-month period preceding the annual fracture assessment; and (3) decreases in lumbar spine bone mineral density Z-scores in the first 6 months of glucocorticoid therapy. As such, we observed that a clinically significant number of children with rheumatic disorders developed incident vertebral fractures in the 3 years following glucocorticoid initiation. Almost one-half of the children were asymptomatic and thereby would have been undiagnosed in the absence of radiographic monitoring. In addition, discrete clinical predictors of incident vertebral fractures were evident early in the course of glucocorticoid therapy

    Contraceptive methods and use by women aged 35 and over: A qualitative study of perspectives

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    <p>Abstract</p> <p>Background</p> <p>More than 30% of the pregnancies in women aged 35 and over are unintended. This paper compares perceptions about contraceptive methods and use among women with and without an unintended pregnancy after turning age 35.</p> <p>Methods</p> <p>Semi-structured, in-depth interviews were conducted with 17 women. They were all 35 to 49 years old, regularly menstruating, sexually active, not sterilized, not desiring a pregnancy in the near future, and at least 3 months postpartum. We purposely sampled for women who had had at least one unintended pregnancy after age 35 (n = 9) and women who did not (n = 8). We assessed partnership, views of pregnancy and motherhood, desired lifestyle, perceived advantages and disadvantages of using and obtaining currently available well-known reversible contraceptives in the U.S. ''We also assessed contraceptive methods used at any time during their reproductive years, including current method use and, if appropriate, circumstances surrounding an unintended pregnancy after age 35.'' Each interview was taped and transcribed verbatim. Data were analyzed using Grounded Theory. Analysis focused on partnership, views of pregnancy, motherhood, desired lifestyle and perceived advantages and disadvantages of various reversible contraceptive methods.</p> <p>Results</p> <p>The women without an unintended pregnancy after age 35 were more likely to (1) use contraceptive methods that helped treat a medical condition, (2) consider pregnancy as dangerous, or (3) express concerns about the responsibilities of motherhood. The women who experienced an unintended pregnancy after age 35 were more likely to (1) report unstable partnerships, (2) perceive themselves at lower risk of pregnancy, or (3) report past experiences with unwanted contraceptive side effects. There was a greater likelihood a woman would choose a contraceptive method if it was perceived as easy to use, accessible, affordable and had minimal side effects.</p> <p>Conclusions</p> <p>Women's perspective on contraceptive use after age 35 varies. Public health messages and health providers' care can help women in this age group by reviewing their fertility risks, as well as all contraceptive methods and their associated side effects. The impact of such interventions on unintended pregnancy rates in this age group should be tested in other areas of evidence-based medicine.</p

    Multiple Sources of Contamination in Samples from Patients Reported to Have XMRV Infection

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    Xenotropic murine leukemia virus (MLV)-related retrovirus (XMRV) was reported to be associated with prostate cancer by Urisman, et al. in 2006 and chronic fatigue syndrome (CFS) by Lombardi, et al. in 2009. To investigate this association, we independently evaluated plasma samples from 4 patients with CFS reported by Lombardi, et al. to have XMRV infection and from 5 healthy controls reported to be XMRV uninfected. We also analyzed viral sequences obtained from supernatants of cell cultures found to contain XMRV after coculture with 9 clinical samples from 8 patients. A qPCR assay capable of distinguishing XMRV from endogenous MLVs showed that the viral sequences detected in the CFS patient plasma behaved like endogenous MLVs and not XMRV. Single-genome sequences (N = 89) from CFS patient plasma were indistinguishable from endogenous MLVs found in the mouse genome that are distinct from XMRV. By contrast, XMRV sequences were detected by qPCR in 2 of the 5 plasma samples from healthy controls (sequencing of the qPCR product confirmed XMRV not MLV). Single-genome sequences (N = 234) from the 9 culture supernatants reportedly positive for XMRV were indistinguishable from XMRV sequences obtained from 22Rv1 and XMRV-contaminated 293T cell-lines. These results indicate that MLV DNA detected in the plasma samples from CFS patients evaluated in this study was from contaminating mouse genomic DNA and that XMRV detected in plasma samples from healthy controls and in cultures of patient samples was due to cross-contamination with XMRV (virus or nucleic acid)

    Racial differences in influenza vaccination among older americans 1996–2000: longitudinal analysis of the Health and Retirement Study (HRS) and the Asset and Health Dynamics Among the Oldest Old (AHEAD) survey

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    BACKGROUND: Influenza is a common and serious public health problem among the elderly. The influenza vaccine is safe and effective. METHODS: The purpose of the study was to determine whether frequencies of receipt vary by race, age group, gender, and time (progress from 1995/1996 to 2000), and whether any racial differences remain in age groups covered by Medicare. Subjects were selected from the Health and Retirement Study (HRS) (12,652 Americans 50–61 years of age (1992–2000)) and the Asset and Health Dynamics Among the Oldest Old (AHEAD) survey (8,124 community-dwelling seniors aged 70+ years (1993–2000)). Using multivariate logistic regression, adjusting for potential confounders, we estimated the relationship between race, age group, gender, time and the main outcome measure, receipt of influenza vaccination in the last 2 years. RESULTS: There has been a clear increase in the unadjusted rates of receipt of influenza vaccination for all groups from 1995/1996 to 2000. However, the proportions immunized are 10–20% higher among White than among Black elderly, with no obvious narrowing of the racial gap from 1995/1996 to 2000. There is an increase in rates from age 50 to age 65. After age 70, the rate appears to plateau. In multivariate analyses, the racial difference remains after adjusting for a series of socioeconomic, health, and health care related variables. (HRS: OR = 0.63 (0.55–0.72), AHEAD: OR = 0.55 (0.44–0.66)) CONCLUSIONS: There is much work left if the Healthy People 2010 goal of 90% of the elderly immunized against influenza annually is to be achieved. Close coordination between public health programs and clinical prevention efforts in primary care is necessary, but to be truly effective, these services must be culturally appropriate

    Control of TH17 cells occurs in the small intestine

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    Interleukin (IL)-17-producing T helper cells (TH17) are a recently identified CD4+ T cell subset distinct from T helper type 1 (TH1) and T helper type 2 (TH2) cells1. TH17 cells can drive antigen specific autoimmune diseases and are considered the main population of pathogenic T cells driving experimental autoimmune encephalomyelitis (EAE)2, the mouse model for multiple sclerosis. The factors that are needed for the generation of TH17 cells have been well-characterized3–6. However, where and how the immune system controls TH17 cells in vivo remains unclear.Here, by using a model of tolerance induced by CD3-specific antibody, a model of sepsis and influenza A viral infection (H1N1), we show that pro-inflammatory TH17 cells can be redirected to and controlled in the small intestine. TH17-specific IL-17A secretion induced expression of the chemokine CCL20 in the small intestine, facilitating the migration of these cells specifically to the small intestine via the CCR6/CCL20 axis. Moreover, we found that TH17 cells are controlled by two different mechanisms in the small intestine: first, they are eliminated via the intestinal lumen and simultaneously pro-inflammatory TH17 cells acquire a regulatory phenotype with in vitro and in vivo immune-suppressive properties (rTH17). These results identify mechanisms limiting TH17 cell pathogenicity and implicate the gastrointestinal tract as a site for control of TH17 cells
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