1,084 research outputs found

    The CEDAR Project

    Full text link
    We describe the plans and objectives of the CEDAR project (Combined e-Science Data Analysis Resource for High Energy Physics) newly funded by the PPARC e-Science programme in the UK. CEDAR will combine the strengths of the well established and widely used HEPDATA database of HEP data and the innovative JetWeb data/Monte Carlo comparison facility, built on the HZTOOL package, and will exploit developing grid technology. The current status and future plans of both of these individual sub-projects within the CEDAR framework are described, showing how they will cohesively provide (a) an extensive archive of Reaction Data, (b) validation and tuning of Monte Carlo programs against these reaction data sets, and (c) a validated code repository for a wide range of HEP code such as parton distribution functions and other calculation codes used by particle physicists. Once established it is envisaged CEDAR will become an important Grid tool used by LHC experimentalists in their analyses and may well serve as a model in other branches of science where there is a need to compare data and complex simulations.Comment: 4 pages, 4 postscript figures, uses CHEP2004.cls. Presented at Computing in High-Energy Physics (CHEP'04), Interlaken, Switzerland, 27th September - 1st October 200

    HepForge: A lightweight development environment for HEP software

    Get PDF
    Setting up the infrastructure to manage a software project can become a task as significant writing the software itself. A variety of useful open source tools are available, such as Web-based viewers for version control systems, "wikis" for collaborative discussions and bug-tracking systems, but their use in high-energy physics, outside large collaborations, is insubstantial. Understandably, physicists would rather do physics than configure project management tools. We introduce the CEDAR HepForge system, which provides a lightweight development environment for HEP software. Services available as part of HepForge include the above-mentioned tools as well as mailing lists, shell accounts, archiving of releases and low-maintenance Web space. HepForge also exists to promote best-practice software development methods and to provide a central repository for re-usable HEP software and phenomenology codes.Comment: 3 pages, 0 figures. To be published in proceedings of CHEP06. Refers to the HepForge facility at http://hepforge.cedar.ac.u

    HepData and JetWeb: HEP data archiving and model validation

    Get PDF
    The CEDAR collaboration is extending and combining the JetWeb and HepData systems to provide a single service for tuning and validating models of high-energy physics processes. The centrepiece of this activity is the fitting by JetWeb of observables computed from Monte Carlo event generator events against their experimentally determined distributions, as stored in HepData. Caching the results of the JetWeb simulation and comparison stages provides a single cumulative database of event generator tunings, fitted against a wide range of experimental quantities. An important feature of this integration is a family of XML data formats, called HepML.Comment: 4 pages, 0 figures. To be published in proceedings of CHEP0

    Livestock Producers and Researchers - A Case Study of an Effective Partnership

    Get PDF
    The Sustainable Grazing Systems Programme (SGS) ran from 1996-2002 with 11 regional producer committees (Regional Producer Network - Simpson et al., 2003) and 6 research sites (National Experiment Andrew & Lodge, 2003) distributed throughout the high rainfall zone of temperate Australia. Each regional committee had a core of producers, with invited scientists and extension practitioners and a paid facilitator. The chair was always a producer and rotated annually. Each regional committee conducted a number of paddock-sized demonstrations of improved grazing management practices on a number of farms within the themes; grazing management and weeds, high input systems, innovative grazing methods for production and the SGS adoption process. Each demonstration was on a producer\u27s property assisted by a local management committee with objective data collected by the regional facilitator. The National research sites investigated the effects of grazing management on sustainable livestock production through five themes; water, nutrients, pastures, animals and biodiversity. Producers had a significant input into the design of the National Experiment and each site had a local advisory committee

    The interaction between wheat roots and soil pores in structured field soil

    Get PDF
    Wheat (Triticum aestivum L.) root growth in the subsoil is usually constrained by soil strength, although roots can use macropores to elongate to deeper layers. The quantitative relationship between the elongation of wheat roots and the soil pore system, however, is still to be determined. We studied the depth distribution of roots of six wheat varieties and explored their relationship with soil macroporosity from samples with the field structure preserved. Undisturbed soil cores (to a depth of 100 cm) were collected from the field and then non-destructively imaged using X-ray computed tomography (at a spatial resolution of 90 ”m) to quantify soil macropore structure and root number density (the number of roots cm–2 within a horizontal cross-section of a soil core). Soil macroporosity changed significantly with depth but not between the different wheat lines. There was no significant difference in root number density between wheat varieties. In the subsoil, wheat roots used macropores, especially biopores (i.e. former root or earthworm channels) to grow into deeper layers. Soil macroporosity explained 59% of the variance in root number density. Our data suggested that the development of the wheat root system in the field was more affected by the soil macropore system than by genotype. On this basis, management practices which enhance the porosity of the subsoil may therefore be an effective strategy to improve deep rooting of wheat

    Tevatron-for-LHC Report of the QCD Working Group

    Get PDF
    The experiments at Run 2 of the Tevatron have each accumulated over 1 inverse femtobarn of high-transverse momentum data. Such a dataset allows for the first precision (i.e. comparisons between theory and experiment at the few percent level) tests of QCD at a hadron collider. While the Large Hadron Collider has been designed as a discovery machine, basic QCD analyses will still need to be performed to understand the working environment. The Tevatron-for-LHC workshop was conceived as a communication link to pass on the expertise of the Tevatron and to test new analysis ideas coming from the LHC community. The TeV4LHC QCD Working Group focussed on important aspects of QCD at hadron colliders: jet definitions, extraction and use of Parton Distribution Functions, the underlying event, Monte Carlo tunes, and diffractive physics. This report summarizes some of the results achieved during this workshop.Comment: 156 pages, Tevatron-for-LHC Conference Report of the QCD Working Grou

    Osmotic adjustment, stomata morphology and function show contrasting responses to water stress in mesic and hydric grasses under elevated CO2 concentration

    Get PDF
    The physiological response of two species of grasses with C3 and C4 mechanisms syndromes, Napier grass (Pennisetum purpureum Schumach × Pennisetum glaucum (L.) R. Br) and hydric common reed grass (Phragmites australis (Cav.) Trin. Ex Steud) was examined under ambient (aCO2) and elevated CO2 (eCO2), in combination with water and temperature stress treatments. Under eCO2 and subjected to water and temperature stress, the Napier grass maintained higher daytime leaf water potential (LWP) by reducing transpiration (E) and executing larger osmotic adjustment (OA) at an average of 0.85 MPa compared with 0.42 MPa for common reed; carbon assimilation (PN) was thus higher for the Napier grass. Under aCO2 and low temperature, water stress induced no significant differences in OA between the grasses, but Napier grass still had higher PN than that of common reed. Recovery in LWP and PN following re-watering of water-stressed plants was more rapid in Napier grass than that in the common reed; the former had also higher water-use efficiency due to its low specific water use (water use/leaf area) that was just a fraction (less than 6%) that of the common reed. Exposure of common reed to eCO2 reduced stomata number, but increased it in the Napier grass, especially when subjected to water stress and high temperature. Exposure to eCO2 enhanced OA capacity and E control in Napier grass resulting in superior physiological profile over the common reed subjected to water and heat stress
    • 

    corecore