University of Leeds

About: University of Leeds is a education organization based out in Leeds, United Kingdom. It is known for research contribution in the topics: Population & Context (language use). The organization has 43481 authors who have published 101856 publications receiving 3672065 citations. The organization is also known as: Leeds University.

Vvv dr1: the first data release of the milky way bulge and southern plane from the near-infrared eso public survey vista variables in the via lactea

Abstract: Context The ESO public survey VISTA variables in the V�a L�ctea (VVV) started in 2010 VVV targets 562 sq deg in the Galactic bulge and an adjacent plane region and is expected to run for about five years Aims: We describe the progress of the survey observations in the first observing season, the observing strategy, and quality of the data obtained Methods: The observations are carried out on the 4-m VISTA telescope in the ZYJHK s filters In addition to the multi-band imaging the variability monitoring campaign in the K s filter has started Data reduction is carried out using the pipeline at the Cambridge Astronomical Survey Unit The photometric and astrometric calibration is performed via the numerous 2MASS sources observed in each pointing Results: The first data release contains the aperture photometry and astrometric catalogues for 348 individual pointings in the ZYJHK s filters taken in the 2010 observing season The typical image quality is 09 arcsec {-10 arcsec} The stringent photometric and image quality requirements of the survey are satisfied in 100% of the JHK s images in the disk area and 90% of the JHK s images in the bulge area The completeness in the Z and Y images is 84% in the disk, and 40% in the bulge The first season catalogues contain 128 � 10 8 stellar sources in the bulge and 168 � 10 8 in the disk area detected in at least one of the photometric bands The combined, multi-band catalogues contain more than 163 � 10 8 stellar sources About 10% of these are double detections because of overlapping adjacent pointings These overlapping multiple detections are used to characterise the quality of the data The images in the JHK s bands extend typically 4 mag deeper than 2MASS The magnitude limit and photometric quality depend strongly on crowding in the inner Galactic regions The astrometry for K s = 15-18 mag has rms 35-175 mas Conclusions: The VVV Survey data products offer a unique dataset to map the stellar populations in the Galactic bulge and the adjacent plane and provide an exciting new tool for the study of the structure, content, and star-formation history of our Galaxy, as well as for investigations of the newly discovered star clusters, star-forming regions in the disk, high proper motion stars, asteroids, planetary nebulae, and other interesting objects Based on observations taken within the ESO VISTA Public Survey VVV, Programme ID 179B-2002

Microscopic theory of linear, entangled polymer chains under rapid deformation including chain stretch and convective constraint release

Abstract: A refined version of the Doi and Edwards tube model for entangled polymer liquids is presented. The model is intended to cover linear chains in the full range of deformation rates from linear to strongly nonlinear flows. The effects of reptation, chain stretch, and convective constraint release are derived from a microscopic stochastic partial differential equation that describes the dynamics of the chain contour down to the length scale of the tube diameter. Contour length fluctuations are also included in an approximate manner. Predictions of mechanical stresses as well as the single chain structure factor under flow are shown. A comparison with experimental data is made in which all model parameters are fixed at universal values or are obtained from linear oscillatory shear measurements. With no parameter modification the model produces good agreement over a wide range of rheological data for entangled polymer solutions, including both nonlinear shear and extension.

Actionable knowledge for environmental decision making: Broadening the usability of climate science

Abstract: Despite the rapid evolution and growing complexity in models of science-society interaction, the rate and breadth of use of scientific knowledge in environmental decision making, especially related to climate variability and change, remain below expectations. This suggests a persistent gap between production and use that, to date, efforts to rethink and restructure science production have not been able to surmount. We review different models of science-policy interfaces to understand how they have influenced the organization of knowledge production and application. We then explore how new approaches to the creation of knowledge have emerged, involving both growing integration across disciplines and greater interaction with users. Finally, we review climate information use in the United States and United Kingdom to explore how the structure of knowledge production and the characteristics of users and their decision environments expose the challenges of broadening usable climate science.

Current evidence for the management of rheumatoid arthritis with biological disease-modifying antirheumatic drugs: a systematic literature review informing the EULAR recommendations for the management of RA

Abstract: Objectives To review the evidence for the efficacy and safety of biological agents in patients with rheumatoid arthritis (RA) to provide data to develop treatment recommendations by the European League Against Rheumatism (EULAR) Task Force. Methods Medline, Embase and Cochrane databases were searched for relevant articles on infliximab (IFX), etanercept (ETN), adalimumab (ADA), certolizumab-pegol (CZP), golimumab (GLM), anakinra (ANA), abatacept (ABT), rituximab (RTX) and tocilizumab (TCZ) published between 1962 and February 2009; published abstracts from the 2007–2008 American College of Rheumatology (ACR) and EULAR conference were obtained. Results 87 articles and 40 abstracts were identified. In methotrexate (MTX) naive patients, biological therapy with IFX, ETN, ADA, GLM or ABT has been shown to improve clinical outcomes (level of evidence 1B). In MTX/other synthetic disease-modifying antirheumatic drug (DMARD) failures all nine biological agents confer benefit (1B), with lower efficacy noted for ANA. RTX, ABT, TCZ and GLM demonstrate efficacy in tumour necrosis factor inhibitor (TNFi) failures (1B). Less evidence exists for switching between IFX, ETN and ADA (3B). Biological and MTX combination therapy is more efficacious than a biological agent alone (1B). A safety review shows no increased malignancy risk compared with conventional DMARDs (3B). TNFi are generally associated with an increased risk of serious bacterial infection, particularly within the first 6 months of treatment initiation; increased tuberculosis (TB) rates with TNFi are highest with the monoclonal antibodies (3B). Conclusions There is good evidence for the efficacy of biological agents in patients with RA. Safety data confirm an increased risk of bacterial infection and TB with TNFi compared with conventional DMARDs.

Dietary fibre in Europe: current state of knowledge on definitions, sources, recommendations, intakes and relationships to health

Abstract: Research into the analysis, physical properties and health effects of dietary fibre has continued steadily over the last 40-50 years. From the knowledge gained, countries have developed guidelines for their populations on the optimal amount of fibre to be consumed each day. Food composition tables from many countries now contain values for the dietary fibre content of foods, and, from these, combined with dietary surveys, population intakes have been determined. The present review assessed the uniformity of the analytical methods used, health claims permitted, recommendations and intakes, particularly from national surveys across Europe and around the world. It also assessed current knowledge on health effects of dietary fibre and related the impact of different fibre types on health. The overall intent was to be able to provide more detailed guidance on the types of fibre which should be consumed for good health, rather than simply a total intake figure, the current situation. Analysis of data indicated a fair degree of uniformity in the definition of dietary fibre, the method used for analysis, the recommended amount to be consumed and a growing literature on effects on digestive health and disease risk. However, national dietary survey data showed that intakes do not reach recommendations and very few countries provide guidance on the types of fibre that are preferable to achieve recommended intakes. Research gaps were identified and ideas suggested to provide information for more detailed advice to the public about specific food sources that should be consumed to achieve health benefits.