6,047 research outputs found

    Whitney coverings and the tent spaces T1,q(γ)T^{1,q}(\gamma) for the Gaussian measure

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    We introduce a technique for handling Whitney decompositions in Gaussian harmonic analysis and apply it to the study of Gaussian analogues of the classical tent spaces T1,qT^{1,q} of Coifman, Meyer and Stein.Comment: 13 pages, 1 figure. Revised version incorporating referee's comments. To appear in Arkiv for Matemati

    HadISD: a quality-controlled global synoptic report database for selected variables at long-term stations from 1973--2011

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    [Abridged] This paper describes the creation of HadISD: an automatically quality-controlled synoptic resolution dataset of temperature, dewpoint temperature, sea-level pressure, wind speed, wind direction and cloud cover from global weather stations for 1973--2011. The full dataset consists of over 6000 stations, with 3427 long-term stations deemed to have sufficient sampling and quality for climate applications requiring sub-daily resolution. As with other surface datasets, coverage is heavily skewed towards Northern Hemisphere mid-latitudes. The dataset is constructed from a large pre-existing ASCII flatfile data bank that represents over a decade of substantial effort at data retrieval, reformatting and provision. These raw data have had varying levels of quality control applied to them by individual data providers. The work proceeded in several steps: merging stations with multiple reporting identifiers; reformatting to netCDF; quality control; and then filtering to form a final dataset. Particular attention has been paid to maintaining true extreme values where possible within an automated, objective process. Detailed validation has been performed on a subset of global stations and also on UK data using known extreme events to help finalise the QC tests. Further validation was performed on a selection of extreme events world-wide (Hurricane Katrina in 2005, the cold snap in Alaska in 1989 and heat waves in SE Australia in 2009). Although the filtering has removed the poorest station records, no attempt has been made to homogenise the data thus far. Hence non-climatic, time-varying errors may still exist in many of the individual station records and care is needed in inferring long-term trends from these data. A version-control system has been constructed for this dataset to allow for the clear documentation of any updates and corrections in the future.Comment: Published in Climate of the Past, www.clim-past.net/8/1649/2012/. 31 pages, 23 figures, 9 pages. For data see http://www.metoffice.gov.uk/hadobs/hadis

    Factors Associated with Emergency Room Choice Among Medicare Patients

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    Changing macroenvironmental factors have caused hospital administrators to reassess their positions across all service lines and market segments. This pilot study explores relationships among the service experience, satisfaction and future patronage decisions among 368 Medicare patients, an often overlooked segmaent, who were recent users of a hospital emergency room

    Age of the Universe: Influence of the Inhomogeneities on the global Expansion-Factor

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    For the first time we calculate quantitatively the influence of inhomogeneities on the global expansion factor by averaging the Friedmann equation. In the framework of the relativistic second-order Zel'dovich-approximation scheme for irrotational dust we use observational results in form of the normalisation constant fixed by the COBE results and we check different power spectra, namely for adiabatic CDM, isocurvature CDM, HDM, WDM, Strings and Textures. We find that the influence of the inhomogeneities on the global expansion factor is very small. So the error in determining the age of the universe using the Hubble constant in the usual way is negligible. This does not imply that the effect is negligible for local astronomical measurements of the Hubble constant. Locally the determination of the redshift-distance relation can be strongly influenced by the peculiar velocity fields due to inhomogeneities. Our calculation does not consider such effects, but is contrained to comparing globally homogeneous and averaged inhomogeneous matter distributions. In addition we relate our work to previous treatments.Comment: 10 pages, version accepted by Phys. Rev.

    Epidermal Growth Factor–PEG Functionalized PAMAM-Pentaethylenehexamine Dendron for Targeted Gene Delivery Produced by Click Chemistry

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    Aim of this study was the site-specific conjugation of an epidermal growth factor (EGF)-polyethylene glycol (PEG) chain by click chemistry onto a poly(amido amine) (PAMAM) dendron, as a key step toward defined multifunctional carriers for targeted gene delivery. For this purpose, at first propargyl amine cored PAMAM dendrons with ester ends were synthesized. The chain terminal ester groups were then modified by oligoamines with different secondary amino densities. The oligoamine-modified PAMAM dendrons were well biocompatible, as demonstrated in cytotoxicity assays. Among the different oligoamine-modified dendrons, PAMAM-pentaethylenehexamine (PEHA) dendron polyplexes displayed the best gene transfer ability. Conjugation of PAMAM-PEHA dendron with PEG spacer was conducted via click reaction, which was performed before amidation with PEHA. The resultant PEG-PAMAM-PEHA copolymer was then coupled with EGF ligand. pDNA transfections in HuH-7 hepatocellular carcinoma cells showed a 10-fold higher efficiency with the polyplexes containing conjugated EGF as compared to the ligand-free ones, demonstrating the concept of ligand targeting. Overall gene transfer efficiencies, however, were moderate, suggesting that additional measures for overcoming subsequent intracellular bottlenecks in delivery have to be taken

    A qualitative study of health promotion in academy schools in England

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    BackgroundSchools are an important setting for health promotion. In England, around one third of publicly funded schools have become independent of local authorities since 2000 and are now academies, run by an academy trust. The aim of this research was to examine attitudes towards health promotion held by academy trust leaders and senior staff. The research questions were: 1. How do academy trusts in England perceive their role in health promotion amongst students? 2. How are decisions around health promotion made in academy trusts? 3. What factors inhibit and encourage health promotion in academy schools? 4. How might public health academics and practitioners best engage with academy schools to facilitate health promotion activity and research?MethodsQualitative study utilising semi-structured interviews. Twenty five academy and school leaders were purposively sampled to achieve variation in trust size and type. In addition, five respondents were recruited from public and third-sector agencies seeking to work with or influence academy trusts around health promotion. Framework analysis was used to determine emergent themes and identify relationships between themes and respondent type. Early findings were triangulated at a stakeholder event with 40 delegates from academia, local authority public health teams, and third sector organisations.ResultsThere is wide variation amongst senior academy and trust leaders in how they perceive the role of academies in promoting health and wellbeing amongst students. There is also variability in whether academy trusts responsible for more than one school adopt a centralised strategy to health promotion or allow individual schools autonomy. This was dependent on the trust leaders’ attitude and interest in health promotion rather than any perceived external accountability. Identified barriers to health promotion include financial constraints, a narrow focus on educational outcomes and school performance, and limited understanding about effective health interventions.ConclusionIn the current absence of national policy or guidance around health promotion in schools, health has variable status in academies in England. There is a need to better engage all academy trusts in health promotion and support them to implement a strategic approach to health promotion

    Averaging in Cosmology

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    In this paper we discuss the effect of local inhomogeneities on the global expansion of nearly FLRW universes, in a perturbative setting. We derive a generic linearized averaging operation for metric perturbations from basic assumptions, and we explicify the issue of gauge invariance. We derive a gauge invariant expression for the back-reaction of density inhomogeneities on the global expansion of perturbed FLRW spacetimes, in terms of observable quantities, and we calculate the effect quantitatively. Since we do not adopt a comoving gauge, our result incorporates the back-reaction on the metric due to scalar velocity and vorticity perturbations. The results are compared with the results by other authors in this field.Comment: 24 pages, Latex, accepted for publication in Phys. Rev.
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