292 research outputs found

    Blazar Flaring Rates Measured with GLAST

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    We derive the minimum observing time scales to detect a blazar at a given flux level with the LAT on GLAST in the scanning and pointing modes. Based upon Phase 1 observations with EGRET, we predict the GLAST detection rate of blazar flares at different flux levels. With some uncertainty given the poor statistics of bright blazars, we predict that a blazar flare with integral flux >~ 200e-8 ph(> 100 MeV) cm^{-2} s^{-1}, which are the best candidates for Target of Opportunity pointings and extensive temporal and spectral studies, should occur every few days.Comment: 7 pages, 2 figures, in 2nd VERITAS Symposium on TeV Astrophysiscs, ed. L. Fortson and S. Swordy, in press, New Astronomy Review

    Exploring Value in Digital Archives and the Comainn Eachdraidh

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    This report engages the multifaceted ways in which Cultural Value is produced by the Comainn Eachdraidh (Historical Societies) movement in the Outer Hebrides of Scotland. It shows how grass-roots community activity surrounding history, heritage and culture can have a resounding impact upon the communities involved, energising them into a variety of different actions. It also highlights how these activities have been finding new expressions through digital technologies, including digital archives and social media, from which different notions of cultural value are being shaped. The following report should be read as a series of vignettes that speaks to the concept of cultural value in different ways. A central proposal from the project is to comprehend cultural value as a flexible and differentiated concept that can mean a number of different things in different spaces and places. This reflects the ethnographic methodology which has been employed to understand the complex ways in which communities in the Outer Hebrides derive benefit from cultural activity and participation. At its core, the report highlights how the production of community heritage in the Outer Hebrides creates cultural value for communities in a variety of different ways: from helping develop connections between land, people and place that are central to the on-going development, the ‘liveliness’ of Gaelic culture, and the benefits sought in building connections and dialogues between people both out with the immediate community and in the extended diaspora

    Comparing health status in Belarus between 2001-10: a novel method using surveys with different response categories

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    Background: Two population surveys were conducted in Belarus: The Living Conditions, Lifestyle and Health (LLH) in 2001 (n=2000) and The Health in Times of Transition (HITT) in 2010 (n=1800). Each survey included a question on health status. The LLH questionnaire provided a 4-point Verbal Response Scale, but the HITT questionnaire used a 5-point scale. When translated into Russian, only two response categories of these scales had identical wording. These differences made a direct comparison of self-reported health status between 2001 and 2010 difficult. Methods: We conducted a Health Category Response Scale (HCRS) survey in 2010 (n=570) using a 100ths graduated Visual Analogue Scale (VAS) to understand how the response categories of different scales are perceived by Russian speakers. We implemented the HCRS survey’s data to calculate the weighted health status (WHS) for each of the original surveys and to compare health status in Belarus between 2001 and 2010. Results: The WHS in Belarus showed a small, but statistically significant, improvement of 2.9 points on a 0–100 scale between 2001 and 2010 (56.2 vs. 59.1). Identical response categories were perceived differently on a 4-point and 5-point VAS. The category ‘good’ (‘Umomwee’) measured ~12 points higher, and the category ‘bad/poor’ (‘Ojmtme’) measured ~16 points lower, on the 4-point compared with the 5-point VAS. Conclusion: Our HCRS survey and novel method enabled a direct comparison of questions with different response options. When applied to the LLH and HITT projects, we concluded that health status in Belarus has improved between 2001 and 2010

    CURIOS: Connecting Community Heritage through Linked Data

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    The CURIOS project explores how digital archives for rural community heritage groups can be made more sustainable so that volunteer members can maintain a lasting digital presence. It is developing software tools to help remote rural communities to collaboratively maintain and present information about their cultural heritage. The objective is to investigate the use of semantic web/linked data technology to build a general, flexible and “future proof” software platform that could help such projects to develop digital archives and to be sustainable over time. As an interdisciplinary project we aim to synthesise a narrative that draws from both social science and computer science perspectives by critically reflecting upon the novel approach taken and the on-going results that are being produced

    Continuous loading of a magnetic trap

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    We have realized a scheme for continuous loading of a magnetic trap (MT). ^{52}Cr atoms are continuously captured and cooled in a magneto-optical trap (MOT). Optical pumping to a metastable state decouples atoms from the cooling light. Due to their high magnetic moment (6 Bohr magnetons), low-field seeking metastable atoms are trapped in the magnetic quadrupole field provided by the MOT. Limited by inelastic collisions between atoms in the MOT and in the MT, we load 10^8 metastable atoms at a rate of 10^8 atoms/s below 100 microkelvin into the MT. After loading we can perform optical repumping to realize a MT of ground state chromium atoms.Comment: 4 pages, 4 figures, version 2, modified references, included additional detailed information, minor changes in figure 3 and in tex

    Opto-mechanical measurement of micro-trap via nonlinear cavity enhanced Raman scattering spectrum

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    High-gain resonant nonlinear Raman scattering on trapped cold atoms within a high-fineness ring optical cavity is simply explained under a nonlinear opto-mechanical mechanism, and a proposal using it to detect frequency of micro-trap on atom chip is presented. The enhancement of scattering spectrum is due to a coherent Raman conversion between two different cavity modes mediated by collective vibrations of atoms through nonlinear opto-mechanical couplings. The physical conditions of this technique are roughly estimated on Rubidium atoms, and a simple quantum analysis as well as a multi-body semiclassical simulation on this nonlinear Raman process is conducted.Comment: 7 pages, 2 figure

    Light microscopic observations of the ruminal papillae of cattle on diets with divergent forage to cereal ratios

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    High levels of supplementation with cereal increases production rates in cattle but can increase incidence of disease, ranging from mild indigestion to acute ruminal acidosis and death. Therefore, there is motivation to determine biological markers which can be used to identify whether animals have been, or are being fed, sufficient or excessive cereals. This study aimed to describe light microscopic findings from animals being fed diverse dietary cereal proportions and to test the performance of a novel rumen epithelial scoring system. Rumen wall tissue samples were obtained from the abattoir from 195 cattle from 11 Scottish farms and processed for histological examination. Light microscopic examination was used to characterise ruminal epithelial response to dietary challenge. Secondary objectives included describing the distribution of immune-related cells in bovine ruminal epithelium and assessing the use of a modified Elastin Martius Scarlet Blue stain (EMSB) for histological examination of the rumen epithelium. Cells staining positive for cluster of differentiation 3 were distributed mainly in the lower layers of the stratum basale and were found in higher densities in animals offered lower cereal proportion diets. Cells staining positive for major histocompatibility complex class 2 (MHCII) were most common in perivascular locations and in the junction between the lower stratum basale and the propria-submucosa. The density of MHCII positive staining cells was higher in animals on lower cereal diets. The level of supplementation with cereal was also associated with the thickness of the stratum corneum (SCT) and stratum granulosum (SGT), the integrity of the stratum corneum and sloughing of cornified cells. There were no advantages in using EMSB stain over haematoxylin and eosin (H and E) in this scoring system. We concluded that a scoring system that included only SCT, SGT and a measure of the loss of appearance of intercellular space allowed differentiation of groups of animals according to the level of cereal supplementation

    Subclinical Thyroid Dysfunction and Fracture Risk: A Meta-analysis

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    IMPORTANCE Associations between subclinical thyroid dysfunction and fractures are unclear and clinical trials are lacking. OBJECTIVE To assess the association of subclinical thyroid dysfunction with hip, nonspine, spine, or any fractures. DATA SOURCES AND STUDY SELECTION The databases of MEDLINE and EMBASE (inception to March 26, 2015) were searched without language restrictions for prospective cohort studies with thyroid function data and subsequent fractures. DATA EXTRACTION Individual participant data were obtained from 13 prospective cohorts in the United States, Europe, Australia, and Japan. Levels of thyroid function were defined as euthyroidism (thyroid-stimulating hormone [TSH], 0.45-4.49 mIU/L), subclinical hyperthyroidism (TSH <0.45 mIU/L), and subclinical hypothyroidism (TSH ≥4.50-19.99 mIU/L) with normal thyroxine concentrations. MAIN OUTCOME AND MEASURES The primary outcome was hip fracture. Any fractures, nonspine fractures, and clinical spine fractures were secondary outcomes. RESULTS Among 70,298 participants, 4092 (5.8%) had subclinical hypothyroidism and 2219 (3.2%) had subclinical hyperthyroidism. During 762,401 person-years of follow-up, hip fracture occurred in 2975 participants (4.6%; 12 studies), any fracture in 2528 participants (9.0%; 8 studies), nonspine fracture in 2018 participants (8.4%; 8 studies), and spine fracture in 296 participants (1.3%; 6 studies). In age- and sex-adjusted analyses, the hazard ratio (HR) for subclinical hyperthyroidism vs euthyroidism was 1.36 for hip fracture (95% CI, 1.13-1.64; 146 events in 2082 participants vs 2534 in 56,471); for any fracture, HR was 1.28 (95% CI, 1.06-1.53; 121 events in 888 participants vs 2203 in 25,901); for nonspine fracture, HR was 1.16 (95% CI, 0.95-1.41; 107 events in 946 participants vs 1745 in 21,722); and for spine fracture, HR was 1.51 (95% CI, 0.93-2.45; 17 events in 732 participants vs 255 in 20,328). Lower TSH was associated with higher fracture rates: for TSH of less than 0.10 mIU/L, HR was 1.61 for hip fracture (95% CI, 1.21-2.15; 47 events in 510 participants); for any fracture, HR was 1.98 (95% CI, 1.41-2.78; 44 events in 212 participants); for nonspine fracture, HR was 1.61 (95% CI, 0.96-2.71; 32 events in 185 participants); and for spine fracture, HR was 3.57 (95% CI, 1.88-6.78; 8 events in 162 participants). Risks were similar after adjustment for other fracture risk factors. Endogenous subclinical hyperthyroidism (excluding thyroid medication users) was associated with HRs of 1.52 (95% CI, 1.19-1.93) for hip fracture, 1.42 (95% CI, 1.16-1.74) for any fracture, and 1.74 (95% CI, 1.01-2.99) for spine fracture. No association was found between subclinical hypothyroidism and fracture risk. CONCLUSIONS AND RELEVANCE Subclinical hyperthyroidism was associated with an increased risk of hip and other fractures, particularly among those with TSH levels of less than 0.10 mIU/L and those with endogenous subclinical hyperthyroidism. Further study is needed to determine whether treating subclinical hyperthyroidism can prevent fractures
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