425 research outputs found

    What evidence is there for the identification and management of frail older people in the emergency department? A systematic mapping review

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    Abstract Background Emergency departments (EDs) are facing unprecedented levels of demand. One of the causes of this increased demand is the ageing population. Older people represent a particular challenge to the ED as those older people who are frail will require management that considers their frailty alongside their presenting complaint. How to identify these older people as frail and how best to manage them in the ED is a major challenge for the health service to address. Objectives To systematically map interventions to identify frail and high-risk older people in the ED and interventions to manage older people in the ED and to map the outcomes of these interventions and examine whether or not there is any evidence of the impact of these interventions on patient and health service outcomes. Design A systematic mapping review. Setting Evidence from developed countries on interventions delivered in the ED. Participants Frail and high-risk older people and general populations of older people (aged > 65 years). Interventions Interventions to identify older people who are frail or who are at high risk of adverse outcomes and to manage (frail) older people within the ED. Main outcome measures Patient outcomes (direct and indirect) and health service outcomes. Data sources Evidence from 103 peer-reviewed articles and conference abstracts and 17 systematic reviews published from 2005 to 2016. Review methods A review protocol was drawn up and a systematic database search was undertaken for the years 2005–2016 (using MEDLINE, EMBASE, The Cochrane Library, Web of Science, Cumulative Index to Nursing and Allied Health Literature, Health Management Information Consortium and PROSPERO). Studies were included according to predefined criteria. Following data extraction, evidence was classified into interventions relating to the identification of frail/high-risk older people in the ED and interventions relating to their management. A narrative synthesis of interventions/outcomes relating to these categories was undertaken. A quality assessment of individual studies was not undertaken; instead, an assessment of the overall evidence base in this area was made. Results Of the 90 included studies, 32 focused on a frail/high-risk population and 60 focused on an older population. These studies reported on interventions to identify (n = 57) and manage (n = 53) older people. The interventions to identify frail and at-risk older people, on admission and at discharge, utilised a number of different tools. There was extensive evidence on these question-based tools, but the evidence was inconclusive and contradictory. Service delivery innovations comprised changes to staffing, infrastructure and care delivery. There was a general trend towards improved outcomes in admissions avoidance, reduced ED reattendance and improved discharge outcomes. Limitations This review was a systematic mapping review. Some of the methods adopted differed from those used in a standard systematic review. Mapping the evidence base has led to the inclusion of a wide variety of evidence (in terms of study type and reporting quality). No recommendations on the effectiveness of specific interventions have been made as this was outside the scope of the review. Conclusions A substantial body of evidence on interventions for frail and high-risk older people was identified and mapped. Future work Future work in this area needs to determine why interventions work and whether or not they are feasible for the NHS and acceptable to patients. Study registration This study is registered as PROSPERO CRD42016043260. Funding The National Institute for Health Research Health Services and Delivery Research programme

    A probabilistic assessment of the rapidity of PETM onset

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    Single-foraminifera measurements of the PETM carbon isotope excursion from Maud Rise have been interpreted as indicating geologically instantaneous carbon release. Here, the authors explain these records using an Earth system model and a sediment-mixing model and extract the likely PETM onset duration

    Controls on intermontane basin filling, isolation and incision on the margin of the Puna Plateau, NW Argentina (similar to 23 degrees S)

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    Intermontane basins are illuminating stratigraphic archives of uplift, denudation and environmental conditions within the heart of actively growing mountain ranges. Commonly, however, it is difficult to determine from the sedimentary record of an individual basin whether basin formation, aggradation and dissection were controlled primarily by climatic, tectonic or lithological changes and whether these drivers were local or regional in nature. By comparing the onset of deposition, sediment-accumulation rates, incision, deformation, changes in fluvial connectivity and sediment provenance in two interrelated intermontane basins, we can identify diverse controls on basin evolution. Here, we focus on the Casa Grande basin and the adjacent Humahuaca basin along the eastern margin of the Puna Plateau in northwest Argentina. Underpinning this analysis is the robust temporal framework provided by U-Pb geochronology of multiple volcanic ashes and our new magnetostratigraphical record in the Humahuaca basin. Between 3.8 and 0.8 Ma, similar to 120 m of fluvial and lacustrine sediments accumulated in the Casa Grande basin as the rate of uplift of the Sierra Alta, the bounding range to its east, outpaced fluvial incision by the Rio Yacoraite, which presently flows eastward across the range into the Humahuaca basin. Detrital zircon provenance analysis indicates a progressive loss of fluvial connectivity from the Casa Grande basin to the downstream Humahuaca basin between 3 and 2.1 Ma, resulting in the isolation of the Casa Grande basin from 2.1 Ma to \u3c 1.7 Ma. This episode of basin isolation is attributed to aridification due to the uplift of the ranges to the east. Enhanced aridity decreased sediment supply to the Casa Grande basin to the point that aggradation could no longer keep pace with the rate of the surface uplift at the outlet of the basin. Synchronous events in the Casa Grande and Humahuaca basins suggest that both the initial onset of deposition above unconformities at similar to 3.8 Ma and the re-establishment of fluvial connectivity at similar to 0.8 Ma were controlled by climatic and/or tectonic changes affecting both basins. Reintegration of the fluvial network allowed subsequent incision in the Humahuaca basin to propagate upstream into the Casa Grande basin

    Cryptic prophages within a Streptococcus pyogenes genotype emm4 lineage

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    The major human pathogen Streptococcus pyogenes shares an intimate evolutionary history with mobile genetic elements, which in many cases carry genes encoding bacterial virulence factors. During recent whole-genome sequencing of a longitudinal sample of S. pyogenes isolates in England, we identified a lineage within emm4 that clustered with the reference genome MEW427. Like MEW427, this lineage was characterized by substantial gene loss within all three prophage regions, compared to MGAS10750 and isolates outside of the MEW427-like lineage. Gene loss primarily affected lysogeny, replicative and regulatory modules, and to a lesser and more variable extent, structural genes. Importantly, prophage-encoded superantigen and DNase genes were retained in all isolates. In isolates where the prophage elements were complete, like MGAS10750, they could be induced experimentally, but not in MEW427-like isolates with degraded prophages. We also found gene loss within the chromosomal island SpyCIM4 of MEW427-like isolates, although surprisingly, the SpyCIM4 element could not be experimentally induced in either MGAS10750-like or MEW427-like isolates. This did not, however, appear to abolish expression of the mismatch repair operon, within which this element resides. The inclusion of further emm4 genomes in our analyses ratified our observations and revealed an international emm4 lineage characterized by prophage degradation. Intriguingly, the USA population of emm4 S. pyogenes appeared to constitute predominantly MEW427-like isolates, whereas the UK population comprised both MEW427-like and MGAS10750-like isolates. The degraded and cryptic nature of these elements may have important phenotypic and fitness ramifications for emm4 S. pyogenes , and the geographical distribution of this lineage raises interesting questions on the population dynamics of the genotype

    Nonperturbative Effects from the Resummation of Perturbation Theory

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    Using the general argument in Borel resummation of perturbation theory that links the divergent perturbation theory to the nonperturbative effect we argue that the nonperturbative effect associated with the perturbation theory should have a branch cut only along the positive real axis in the complex coupling plane. The component in the weak coupling expansion of the nonperturbative amplitude, which usually includes the leading term in the weak coupling expansion, that gives rise to the branch cut can be calculated in principle from the perturbation theory combined with some exactly calculable properties of the nonperturbative effect. The realization of this mechanism is demonstrated in the double well potential and the two-dimensional O(N) nonlinear sigma model. In these models the leading term in weak coupling of the nonperturbative effect can be obtained with good accuracy from the first terms of the perturbation theory. Applying this mechanism to the infrared renormalon induced nonperturbative effect in QCD, we suggest some of the QCD condensate effects can be calculated in principle from the perturbation theory.Comment: 21 Pages, 1 Figure; To appear in Phys Rev

    Strong coupling constant from Ď„\tau decay within renormalization scheme invariant treatment

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    We extract a numerical value for the strong coupling constant \alpha_s from the \tau-lepton decay rate into nonstrange particles. A new feature of our procedure is the explicit use of renormalization scheme invariance in analytical form in order to perform the actual analysis in a particular renormalization scheme. For the reference coupling constant in the \MSsch-scheme we obtain \alpha_s(M_\tau)= 0.3184 \pm 0.0060_{exp} which corresponds to \al_s(M_Z)= 0.1184 \pm 0.0007_{exp} \pm 0.0006_{hq mass}. This new numerical value is smaller than the standard value from Ď„\tau-data quoted in the literature and is closer to \al_s(M_Z)-values obtained from high energy experiments.Comment: 8 page

    Perturbation evolution with a non-minimally coupled scalar field

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    We recently proposed a simple dilaton-derived quintessence model in which the scalar field was non-minimally coupled to cold dark matter, but not to `visible' matter. Such couplings can be attributed to the dilaton in the low energy limit of string theory, beyond tree level. In this paper we discuss the implications of such a model on structure formation, looking at its impact on matter perturbations and CMB anisotropies. We find that the model only deviates from Λ\LambdaCDM and minimally coupled theories at late times, and is well fitted to current observational data. The signature left by the coupling, when it breaks degeneracy at late times, presents a valuable opportunity to constrain non-minimal couplings given the wealth of new observational data promised in the near future.Comment: Version appearing in Physical Review D. 10 pages, 9 figs. Comparison with SN1a and projected MAP results, and appendix adde

    CD9 co-operation with syndecan-1 is required for a major staphylococcal adhesion pathway

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    Epithelial colonization is a critical first step in bacterial pathogenesis. Staphylococcus aureus can utilize several host factors to associate with cells, including α5β1 integrin and heparan sulfate proteoglycans, such as the syndecans. Here, we demonstrate that a partner protein of both integrins and syndecans, the host membrane adapter protein tetraspanin CD9, is essential for syndecan-mediated staphylococcal adhesion. Fibronectin is also essential in this process, while integrins are only critical for post-adhesion entry into human epithelial cells. Treatment of epithelial cells with CD9-derived peptide or heparin caused significant reductions in staphylococcal adherence, dependent on both CD9 and syndecan-1. Exogenous fibronectin caused a CD9-dependent increase in staphylococcal adhesion, whereas blockade of β1 integrins did not affect adhesion but did reduce the subsequent internalization of adhered bacteria. CD9 disruption or deletion increased β1 integrin-mediated internalization, suggesting that CD9 coordinates sequential staphylococcal adhesion and internalization. CD9 controls staphylococcal adhesion through syndecan-1, using a mechanism that likely requires CD9-mediated syndecan organization to correctly display fibronectin at the host cell surface. We propose that CD9-derived peptides or heparin analogs could be developed as anti-adhesion treatments to inhibit the initial stages of staphylococcal pathogenesis
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