3,148 research outputs found

    A contemporaneous infrared flash from a long gamma-ray burst: an echo from the central engine

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    The explosion that results in a cosmic gamma-ray burst (GRB) is thought to produce emission from two physical processes -- the activity of the central engine gives rise to the high-energy emission of the burst through internal shocking and the subsequent interaction of the flow with the external environment produces long-wavelength afterglow. While afterglow observations continue to refine our understanding of GRB progenitors and relativistic shocks, gamma-ray observations alone have not yielded a clear picture of the origin of the prompt emission nor details of the central engine. Only one concurrent visible-light transient has been found and was associated with emission from an external shock. Here we report the discovery of infrared (IR) emission contemporaneous with a GRB, beginning 7.2 minutes after the onset of GRB 041219a. Our robotic telescope acquired 21 images during the active phase of the burst, yielding the earliest multi-colour observations of any long-wavelength emission associated with a GRB. Analysis of an initial IR pulse suggests an origin consistent with internal shocks. This opens a new possibility to study the central engine of GRBs with ground-based observations at long wavelengths.Comment: Accepted to Nature on March 1, 2005. 9 pages, 4 figures, nature12.cls and nature1.cls files included. This paper is under press embargo until print publicatio

    Issues potentially affecting quality of life arising from long-term medicines use: a qualitative study

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    Background Polypharmacy is increasing and managing large number of medicines may create a burden for patients. Many patients have negative views of medicines and their use can adversely affect quality of life. No studies have specifically explored the impact of general long-term medicines use on quality of life. Objective To determine the issues which patients taking long-term medicines consider affect their day-to-day lives, including quality of life. Setting Four primary care general practices in North West England Methods Face-to-face interviews with adults living at home, prescribed four or more regular medicines for at least 1 year. Interviewees were identified from primary care medical records and purposively selected to ensure different types of medicines use. Interviews were recorded, transcribed and analysed thematically. Results Twenty-one interviews were conducted and analysed. Patients used an average of 7.8 medicines, 51 % were preventive, 40 % for symptom relief and 9 % treatment. Eight themes emerged: relationships with health professionals, practicalities, information, efficacy, side effects, attitudes, impact and control. Ability to discuss medicines with health professionals varied and many views were coloured by negative experiences, mainly with doctors. All interviewees had developed routines for using multiple medicines, some requiring considerable effort. Few felt able to exert control over medicines routines specified by health professionals. Over half sought additional information about medicines whereas others avoided this, trusting in doctors to guide their medicines use. Patients recognised their inability to assess efficacy for many medicines, notably those used for prophylaxis. All were concerned about possible side effects and some had poor experiences of discussing concerns with doctors. Medicines led to restrictions on social activities and personal life to the extent that, for some, life can revolve around medicines. Conclusion There is a multiplicity and complexity of issues surrounding medicines use, which impact on day-to-day lives for patients with long-term conditions. While most patients adapt to long-term medicines use, others did so at some cost to their quality of life

    Social, environmental and psychological factors associated with objective physical activity levels in the over 65s

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    Objective: To assess physical activity levels objectively using accelerometers in community dwelling over 65 s and to examine associations with health, social, environmental and psychological factors. Design: Cross sectional survey. Setting: 17 general practices in Scotland, United Kingdom. Participants: Random sampling of over 65 s registered with the practices in four strata young-old (65–80 years), old-old (over 80 years), more affluent and less affluent groups. Main Outcome Measures: Accelerometry counts of activity per day. Associations between activity and Theory of Planned Behaviour variables, the physical environment, health, wellbeing and demographic variables were examined with multiple regression analysis and multilevel modelling. Results: 547 older people (mean (SD) age 79(8) years, 54% female) were analysed representing 94% of those surveyed. Accelerometry counts were highest in the affluent younger group, followed by the deprived younger group, with lowest levels in the deprived over 80 s group. Multiple regression analysis showed that lower age, higher perceived behavioural control, the physical function subscale of SF-36, and having someone nearby to turn to were all independently associated with higher physical activity levels (R2 = 0.32). In addition, hours of sunshine were independently significantly associated with greater physical activity in a multilevel model. Conclusions: Other than age and hours of sunlight, the variables identified are modifiable, and provide a strong basis for the future development of novel multidimensional interventions aimed at increasing activity participation in later life.Publisher PDFPeer reviewe

    Impacts of organic and conventional crop management on diversity and activity of free-living nitrogen fixing bacteria and total bacteria are subsidiary to temporal effects

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    A three year field study (2007-2009) of the diversity and numbers of the total and metabolically active free-living diazotophic bacteria and total bacterial communities in organic and conventionally managed agricultural soil was conducted at the Nafferton Factorial Systems Comparison (NFSC) study, in northeast England. The result demonstrated that there was no consistent effect of either organic or conventional soil management across the three years on the diversity or quantity of either diazotrophic or total bacterial communities. However, ordination analyses carried out on data from each individual year showed that factors associated with the different fertility management measures including availability of nitrogen species, organic carbon and pH, did exert significant effects on the structure of both diazotrophic and total bacterial communities. It appeared that the dominant drivers of qualitative and quantitative changes in both communities were annual and seasonal effects. Moreover, regression analyses showed activity of both communities was significantly affected by soil temperature and climatic conditions. The diazotrophic community showed no significant change in diversity across the three years, however, the total bacterial community significantly increased in diversity year on year. Diversity was always greatest during March for both diazotrophic and total bacterial communities. Quantitative analyses using qPCR of each community indicated that metabolically active diazotrophs were highest in year 1 but the population significantly declined in year 2 before recovering somewhat in the final year. The total bacterial population in contrast increased significantly each year. Seasonal effects were less consistent in this quantitative study

    Wavelet-Based Detection of Outliers in Poisson INAR(1) Time Series

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    The presence of outliers or discrepant observations has a negative impact in time series modelling. This paper considers the problem of detecting outliers, additive or innovational, single, multiple or in patches, in count time series modelled by first-order Poisson integer-valued autoregressive, PoINAR(1), models. To address this problem, two wavelet-based approaches that allow the identification of the time points of outlier occurrence are proposed. The effectiveness of the proposed methods is illustrated with synthetic as well as with an observed dataset

    Uromodulin concentrations are not associated with incident CKD among persons with coronary artery disease

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    <p>Abstract</p> <p>Background</p> <p>A common variant of the UMOD gene was linked with prevalent chronic kidney disease (CKD) in large, genomics consortia. One community-based study found that urine concentrations of the uromodulin protein forecast risk of incident CKD. This study within persons with known coronary artery disease (CAD) evaluated whether uromodulin concentrations could distinguish CKD risk.</p> <p>Methods</p> <p>In the Heart and Soul Study, the UMOD snp (12917707) was genotyped in 879 individuals with baseline creatinine clearance (CrCl) measured from a 24-hour urine collection. Uromodulin protein was measured from stored urine specimens among a subset of 120 participants, balanced by genotype. Incident CKD cases (N = 102) were defined by an initial CrCl > 70 ml/min and a 5-year follow-up CrCl <60 ml/min; controls (N = 94) were matched on age, sex, and race.</p> <p>Results</p> <p>Among 527 self-described White participants with DNA, 373 (71%) were homozygous for the dominant allele (G/G), 133 (25%) were heterozygous (G/T) and only 21 (4%) were homozygous for the minor allele (T/T). The T/T genotype had an approximately 11 ml/min higher CrCl than the other 2 groups, but this difference did not reach statistical significance (p = 0.20). The T/T genotype had significantly lower uromodulin levels than the common G/G genotype, and the G/T genotype had intermediate levels. However, uromodulin concentrations were similar between cases and controls (44 vs. 48 mg/dL, p = 0.88).</p> <p>Conclusions</p> <p>This study among a cohort of persons with established CAD found no association between urine uromodulin and incident CKD, although UMOD genotype was associated with urine uromodulin concentrations.</p

    Fibroma of tendon sheath located within the ankle joint capsule

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    We report a very rare case of fibroma of the tendon sheath arising from the anteromedial ankle joint capsule, with no apparent connection to any tendon in the area, found in a 58-year-old patient complaining of progressive local swelling. This uncommon tumor has its usual localization in tendon sheaths, is extremely rare in joint capsules, and has never been described in this location previously. MRI showed nonuniform low signal intensity in T1- and T2-weighted images and high intensity in STIR images. The mass was completely excised by open surgery. Histopathological analysis later confirmed the diagnosis of a fibroma of the tendon sheath

    Teaching child and adolescent psychiatry to undergraduate medical students - A survey in German-speaking countries

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    Objective To conduct a survey about teaching child and adolescent psychiatry to undergraduate medical students in German-speaking countries. Methods A questionnaire was sent to the 33 academic departments of child and adolescent psychiatry in Germany, Austria, and the German-speaking part of Switzerland. Results All departments responded. For teaching knowledge, the methods most commonly reported were lectures and case presentations. The most important skills to be taught were thought to be how to assess psychopathology in children and how to assess families. For elective courses, the departments reported using a wide range of teaching methods, many with active involvement of the students. An average of 34 hours per semester is currently allocated by the departments for teaching child and adolescent psychiatry to medical students. Required courses are often taught in cooperation with adult psychiatry and pediatrics. Achievement of educational objectives is usually assessed with written exams or multiple-choice tests. Only a minority of the departments test the achievement of skills. Conclusions Two ways of improving education in child and adolescent psychiatry are the introduction of elective courses for students interested in the field and participation of child and adolescent psychiatrists in required courses and in longitudinal courses so as to reach all students. Cooperation within and across medical schools can enable departments of child and adolescent psychiatry, despite limited resources, to become more visible and this specialty to become more attractive to medical students. Compared to the findings in earlier surveys, this survey indicates a trend towards increased involvement of academic departments of child and adolescent psychiatry in training medical students

    Potential health impacts of heavy metals on HIV-infected population in USA.

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    Noninfectious comorbidities such as cardiovascular diseases have become increasingly prevalent and occur earlier in life in persons with HIV infection. Despite the emerging body of literature linking environmental exposures to chronic disease outcomes in the general population, the impacts of environmental exposures have received little attention in HIV-infected population. The aim of this study is to investigate whether individuals living with HIV have elevated prevalence of heavy metals compared to non-HIV infected individuals in United States. We used the National Health and Nutrition Examination Survey (NHANES) 2003-2010 to compare exposures to heavy metals including cadmium, lead, and total mercury in HIV infected and non-HIV infected subjects. In this cross-sectional study, we found that HIV-infected individuals had higher concentrations of all heavy metals than the non-HIV infected group. In a multivariate linear regression model, HIV status was significantly associated with increased blood cadmium (p=0.03) after adjusting for age, sex, race, education, poverty income ratio, and smoking. However, HIV status was not statistically associated with lead or mercury levels after adjusting for the same covariates. Our findings suggest that HIV-infected patients might be significantly more exposed to cadmium compared to non-HIV infected individuals which could contribute to higher prevalence of chronic diseases among HIV-infected subjects. Further research is warranted to identify sources of exposure and to understand more about specific health outcomes

    Age-related associations of hypertension and diabetes mellitus with chronic kidney disease

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    <p>Abstract</p> <p>Background</p> <p>Studies suggest end-stage renal disease incidence and all-cause mortality rates among patients with chronic kidney disease (CKD) differ by age. The association of diabetes mellitus and hypertension with CKD across the adult lifespan is not well established.</p> <p>Methods</p> <p>Data from NHANES 1999–2004 were used to determine the association of risk factors for stage 3 or 4 CKD (n = 12,518) and albuminuria (n = 12,778) by age grouping (20 to 49, 50 to 69, and ≥70 years). Stage 3 or 4 CKD was defined as an estimated glomerular filtration rate of 15 to 59 ml/min/1.73 m<sup>2 </sup>and albuminuria as an albumin to creatinine ratio ≥30 mg/g.</p> <p>Results</p> <p>For adults 20 to 49, 50 to 69 and ≥70 years of age, the prevalence ratios (95% confidence interval) of stage 3 or 4 CKD associated with hypertension were 1.94 (0.86 – 4.35), 1.51 (1.09 – 2.07), 1.31 (1.15 – 1.49), respectively (p-trend = 0.038). The analogous prevalence ratios (95% confidence interval) were 3.01 (1.35 – 6.74), 1.61 (1.15 – 2.25), 1.40 (1.15 – 1.69), respectively, for diagnosed diabetes mellitus (p-trend = 0.067); and 2.67 (0.53 – 13.4), 1.35 (0.69 – 2.63), 1.08 (0.78 – 1.51), respectively, for undiagnosed diabetes mellitus (p-trend = 0.369). The prevalence ratios of albuminuria associated with hypertension and diagnosed and undiagnosed diabetes mellitus were lower at older age (each p < 0.05).</p> <p>Conclusion</p> <p>Among US adults, diabetes mellitus and hypertension are associated with CKD and albuminuria regardless of age. However, the associations were stronger at younger ages.</p
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