7,673 research outputs found

    Central Acceptance Testing for Camera Technologies for CTA

    Full text link
    The Cherenkov Telescope Array (CTA) is an international initiative to build the next generation ground based very-high energy gamma-ray observatory. It will consist of telescopes of three different sizes, employing several different technologies for the cameras that detect the Cherenkov light from the observed air showers. In order to ensure the compliance of each camera technology with CTA requirements, CTA will perform central acceptance testing of each camera technology. To assist with this, the Camera Test Facilities (CTF) work package is developing a detailed test program covering the most important performance, stability, and durability requirements, including setting up the necessary equipment. Performance testing will include a wide range of tests like signal amplitude, time resolution, dead-time determination, trigger efficiency, performance testing under temperature and humidity variations and several others. These tests can be performed on fully-integrated cameras using a portable setup at the camera construction sites. In addition, two different setups for performance tests on camera sub-units are being built, which can provide early feedback for camera development. Stability and durability tests will include the long-term functionality of movable parts, water tightness of the camera housing, temperature and humidity cycling, resistance to vibrations during transport or due to possible earthquakes, UV-resistance of materials and several others. Some durability tests will need to be contracted out because they will need dedicated equipment not currently available within CTA. The planned test procedures and the current status of the test facilities will be presented.Comment: 8 pages, 3 figures. In Proceedings of the 34th International Cosmic Ray Conference (ICRC2015), The Hague, The Netherlands. All CTA contributions at arXiv:1508.0589

    Critical review of the impacts of grazing intensity on soil organic carbon storage and other soil quality indicators in extensively managed grasslands

    Get PDF
    Acknowledgements This work contributes to the N-Circle project (grant number BB/N013484/1), and CINAg (BB/N013468/1) Virtual Joint Centres on Agricultural Nitrogen (funded by the Newton Fund via UK BBSRC/NERC), U-GRASS (grant number NE/M016900/1), the Belmont Forum/FACCE-JPI DEVIL project (grant number NE/M021327/1), Soils-R-GGREAT (grant number NE/P019455/1), ADVENT (grant number NE/M019713/1), Sêr Cymru LCEE-NRN project, Climate-Smart Grass and the Scottish Government’s Strategic Research Programme.Peer reviewedPublisher PD

    Is BMI alone a sufficient outcome to evaluate interventions for child obesity?

    Get PDF
    BACKGROUND: BMI is often used to evaluate the effectiveness of childhood obesity interventions, but such interventions may have additional benefits independent of effects on adiposity. We investigated whether benefits to health outcomes following the Mind, Exercise, Nutrition…Do It! (MEND) childhood obesity intervention were independent of or associated with changes in zBMI. METHODS: A total of 79 obese children were measured at baseline; 71 and 42 participants were followed-up at 6 and 12 months respectively, and split into four groups depending on magnitude of change in zBMI. Differences between groups for waist circumference, cardiovascular fitness, physical and sedentary activities, and self-esteem were investigated. RESULTS: Apart from waist circumference and its z-score, there were no differences or trends across zBMI subgroups for any outcome. Independent of the degree of zBMI change, benefits in several parameters were observed in children participating in this obesity intervention. CONCLUSION: We concluded that isolating a single parameter like zBMI change and neglecting other important outcomes is restrictive and may undermine the evaluation of childhood obesity intervention effectiveness

    Observations of TeV gamma rays from Markarian 501 at large zenith angles

    Get PDF
    TeV gamma rays from the blazar Markarian 501 have been detected with the University of Durham Mark 6 atmospheric Cerenkov telescope using the imaging technique at large zenith angles. Observations were made at zenith angles in the range 70 - 73 deg during 1997 July and August when Markarian 501 was undergoing a prolonged and strong flare.Comment: 7 pages, 2 figures, accepted for publication in J. Phys. G.: Nucl. Part. Phy

    Diagnosing ENSO and global warming tropical precipitation shifts using surface relative humidity and temperature

    Get PDF
    This is the final version of the article. Available from American Meteorological Society via the DOI in this recordLarge uncertainty remains in future projections of tropical precipitation change under global warming. A simplified method for diagnosing tropical precipitation change is tested here on present day El Niño-Southern Oscillation (ENSO) precipitation shifts. This method, based on the weak temperature gradient approximation, assumes precipitation is associated with local surface relative humidity (RH) and air temperature (SAT), relative to the tropical mean. Observed and simulated changes in RH and SAT are subsequently used to diagnose changes in precipitation. Present day ENSO precipitation shifts are successfully diagnosed using observations (r = 0:69), and an ensemble of atmosphere-only (0:51 ≤ r ≤ 0:8) and coupled (0:5 ≤ r ≤ 0:87) climate model simulations. RH (r = 0:56) is much more influential than SAT (r = 0:27) in determining ENSO precipitation shifts for observations and climate model simulations over both land and ocean. Using inter-model differences, a significant relationship is demonstrated between method performance over ocean for present day ENSO and projected global warming (r = 0:68). As a caveat, we note that mechanisms leading to ENSO-related precipitation changes are not a direct analogue for global warming-related precipitation changes. The diagnosis method presented here demonstrates plausible mechanisms which relate changes in precipitation, RH and SAT under different climate perturbations. Therefore, uncertainty in future tropical precipitation changes may be linked with uncertainty in future RH and SAT changes.AT was supported by a NERC studentship NE/M009599/1 and CASE funding from the Met Office. FHL was part supported by the UK-China Research and Innovation Partnership Fund through the Met Office Climate Science for Service Partnership (CSSP) China as part of the Newton Fund. RC was supported by the Newton Fund through the Met Office Climate Science for Service Partnership Brazil (CSSP Brazil)

    Plasma Cell Granuloma of the Thyroid: A Conservative Approach to a Rare Condition and Review of the Literature

    Get PDF
    Introduction. We present a case of an 89-year-old female who attended our surgical endocrine clinic with a 3-month history of a left-sided neck lump. There was no past medical history of thyroid disease. Methods. Following examination and further investigation, including core biopsy, a diagnosis of plasma cell granuloma of the thyroid was made. Biochemical testing of thyroid function and Thyroid Peroxidase Antibody was in-keeping with an associated Hashimoto's thyroiditis. Results. The patient was treated conservatively with thyroxine and regularly seen in clinic. TSH levels improved and the lump showed signs of regression. Conclusion. Plasma cell granuloma of the thyroid is rare with only 16 previously reported cases. We present a new approach to management without the use of surgery or steroids. The literature is reviewed comparing clinico-pathological features and management of other reported cases

    Variation between European eel Anguilla anguilla (L.) stocks in five marshes of the Thames Estuary (United Kingdom)

    Get PDF
    The European eel (Anguilla anguilla, L.) was historically widely distributed throughout the United Kingdom, in coastal waters, lakes, rivers and wetlands. Recruitment has declined in recent decades and the species is now listed as ‘Critically Endangered’ on the International Union for Conservation of Nature and Natural Resources (IUCN) Red List. Management of suitable wetland habitats may contribute to species recovery; however, little is known about the stocks in these areas. In this study, yellow (adult stage > 300 mm) eels were sampled in ditches in five marshes bordering the Thames Estuary in England, UK. Ecological variables, including ditch characteristics, invertebrate abundance and water quality parameters were measured. Habitat features were also observed and recorded, including access, land use and water management regimes. Eels were found in all marshes, but at varying catch-per-unit-effort (CPUE). There were no significant correlations between CPUE and the ecological variables, except ditch width. However, a significant difference in CPUE was found between two of the marshes, which may be explained by variations in local habitat management. Mean lengths showed a high proportion of females and mean body condition of four of the marshes was also found to be greater than in three rivers in the same region. These findings suggest that the marshes are potentially favourable eel habitats and that factors influencing habitat quality, such as land use and water management, may affect eel abundance, production of females and body condition. Effective management of such wetlands may therefore contribute to the conservation of European eel
    corecore