829 research outputs found

    Childhood and Adolescent Obesity: Nationwide Pediatric Healthcare Provider Practices and Their Role in Treatment and Prevention of the Obesity Epidemic

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    The purpose of this research is to explore screening and treatment patterns as well as the underlying provider confidence in their decision-making related to the overweight and obese child and adolescent patient. The screening and treatment of obesity in the child and adolescent population are affected by complex social implications and physical side effects. Without a clear consensus on screening, diagnosis and alternative treatment plans, healthcare providers will not maximize the opportunity to provide primary and secondary prevention to the growing epidemic. Statistical analysis of secondary survey data was conducted to explore screening and treatment patterns as well as the underlying health care provider confidence in their decision making related to the overweight and obese child and adolescent patient. The original investigators are comprised of the authors from the six published articles in Pediatrics (Vol. 110 No. 1 July 2002). These articles examined the results of a needs assessment eight page questionnaire consisting of 35 questions from three topic areas related to childhood and adolescent obesity (Area 1 focused on attitudes, perceived skills and training needs of providers. Area 2 addressed provider approach to assessment and treatment. Area 3 collected information pertaining to provider characteristics and practice information). Results indicate that the majority of pediatric providers are concerned about the current status of childhood and adolescent obesity. Furthermore, perceived skill proficiency and interest in further education are influenced by provider’s belief that barriers to effective treatment exist. Barriers include lack of clinician time, lack or reimbursement, lack of parent involvement and patient motivation, lack of support services, futility of treatment, misinformed provider beliefs, need for further training, and years in practice. This highlights the fact that obesity is a multifaceted and complex condition that is difficult to manage in the pediatric population. Many challenges exist in improving diagnosis and treatment practices, but provider interest in training provides an ample opportunity to address pertinent barriers and to develop practitioner guidelines, protocols, and educational tools

    Widespread late Cenozoic increase in erosion rates across the interior of eastern Tibet constrained by detrital low-temperature thermochronometry

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    New detrital low-temperature thermochronometry provides estimates of long-term erosion rates and the timing of initiation of river incision from across the interior of the Tibetan Plateau. We use the erosion history of this region to evaluate proposed models of orogenic development as well as regional climatic events. Erosion histories of the externally drained portion of the east-central Tibetan Plateau are recorded in modern river sands from major rivers across a transect that spans >750 km and covers a region with no published thermochronometric ages. Individual grains from eight catchments were analyzed for apatite (U-Th)/He and fission track thermochronometry. A wide distribution in ages that, in most cases, spans the entire Cenozoic and Late Mesozoic eras requires a long period of slow or no erosion with a relative increase in erosion rate toward the present. We apply a recently developed methodology for inversion of detrital thermochronometric data for three specified erosion scenarios: constant erosion rate, two-stage erosion history, and three-stage erosion history. Modeling results suggest that rates increase by at least an order of magnitude between 11 and 4 Ma following a period of slow erosion across the studied catchments. Synchroneity in accelerated erosion across the whole of the Tibetan Plateau rather than a spatial or temporal progression challenges the widely held notion that the plateau evolved as a steep, northward-propagating topographic front, or that south to north precipitation gradients exert a primary control on erosion rates. Instead, we suggest that accelerated river incision late in the orogen's history relates to regional-scale uplift that occurred in concert with eastern expansion of the plateau

    Identification and Characterization of Thymic Epithelial Progenitor Cells

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    AbstractT cell differentiation and repertoire selection depend critically on several distinct thymic epithelial cell types, whose lineage relationships are unclear. We have investigated these relationships via functional analysis of the epithelial populations within the thymic primordium. Here, we show that mAbs MTS20 and MTS24 identify a population of cells that, when purified and grafted ectopically, can differentiate into all known thymic epithelial cell types, attract lymphoid progenitors, and support CD4+ and CD8+ T cell development in nude mice. In contrast, other epithelial populations in the thymic primordium can fulfill none of these functions. These data establish that the MTS20+24+ population is sufficient to generate a functional thymus in vivo and thus argue strongly that all thymic epithelial cell types derive from a common progenitor cell

    Low-temperature thermochronometry along the Kunlun and Haiyuan Faults, NE Tibetan Plateau: Evidence for kinematic change during late-stage orogenesis

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    The Tibetan Plateau is a prime example of a collisional orogen with widespread strike-slip faults whose age and tectonic significance remain controversial. We present new low-temperature thermochronometry to date periods of exhumation associated with Kunlun and Haiyuan faulting, two major strike-slip faults within the northeastern margin of Tibet. Apatite and zircon (U-Th)/He and apatite fission-track ages, which record exhumation from ~2 to 6 km crustal depths, provide minimum bounds on fault timing. Results from Kunlun samples show increased exhumation rates along the western fault segment at circa 12–8 Ma with a possible earlier phase of motion from ~30–20 Ma, along the central fault segment at circa 20–15 Ma, and along the eastern fault segment at circa 8–5 Ma. Combined with previous studies, our results suggest that motion along the Haiyuan fault may have occurred as early as ~15 Ma along the western/central fault segment before initiating at least by 10–8 Ma along the eastern fault tip. We relate an ~250 km wide zone of transpressional shear to synchronous Kunlun and Haiyuan fault motion and suggest that the present-day configuration of active faults along the northeastern margin of Tibet was likely established since middle Miocene time. We interpret the onset of transpression to relate to the progressive confinement of Tibet against rigid crustal blocks to the north and expansion of crustal thickening to the east during the later stages of orogen development

    Effects of a demand-led evidence briefing service on the uptake and use of research evidence by commissioners of health services:A controlled before-and-after study

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    Background: The Health and Social Care Act 2012 has mandated research use as a core consideration of health service commissioning arrangements. We evaluated whether or not access to a demand-led evidence briefing service improved use of research evidence by commissioners compared with less intensive and less targeted alternatives. Design: Controlled before-and-after study. Setting: Clinical Commissioning Groups (CCGs) in the north of England. Main outcome measures: Change at 12 months from baseline of a CCG’s ability to acquire, assess, adapt and apply research evidence to support decision-making. Secondary outcomes measured individual clinical leads’ and managers’ intentions to use research evidence in decision-making. Methods: Nine CCGs received one of three interventions: (1) access to an evidence briefing service; (2) contact plus an unsolicited push of non-tailored evidence; or (3) an unsolicited push of non-tailored evidence. Data for the primary outcome measure were collected at baseline and 12 months post intervention, using a survey instrument devised to assess an organisation’s ability to acquire, assess, adapt and apply research evidence to support decision-making. In addition, documentary and observational evidence of the use of the outputs of the service was sought and interviews with CCG participants were undertaken. Results: Most of the requests were conceptual; they were not directly linked to discrete decisions or actions but intended to provide knowledge about possible options for future actions. Symbolic use to justify existing decisions and actions were less frequent and included a decision to close a walk-in centre and to lend weight to a major initiative to promote self-care already under way. The opportunity to impact directly on decision-making processes was limited to work to establish disinvestment policies. In terms of impact overall, the evidence briefing service was not associated with increases in CCGs’ capacity to acquire, assess, adapt and apply research evidence to support decision-making, individual intentions to use research findings or perceptions of CCGs’ relationships with researchers. Regardless of the intervention received, at baseline participating CCGs indicated that it felt it was inconsistent in its research-seeking behaviours and its capacity to acquire research remained so at follow-up. The informal nature of decision-making processes meant that there was little or no traceability of the use of evidence. Limitations: Low baseline and follow-up response rates (of 68% and 44%, respectively) and missing data limit the reliability of these findings. Conclusions: Access to a demand-led evidence briefing service did not improve the uptake and use of research evidence by NHS commissioners compared with less intensive and less targeted alternatives. Commissioners appear to be well intentioned but ad hoc users of research. Future work: Further research is required on the effects of interventions and strategies to build individual and organisational capacity to use research. Resource-intensive approaches to providing evidence may best be employed to support instrumental decision-making. Comparative evaluation of the impact of less intensive but targeted strategies on the uptake and use of research by commissioners is warranted. Funding: National Institute for Health Research Health Services and Delivery Research programme

    The growth of northeastern Tibet and its relevance to large-scale continental geodynamics: A review of recent studies

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    Recent studies of the northeastern part of the Tibetan Plateau have called attention to two emerging views of how the Tibetan Plateau has grown. First, deformation in northern Tibet began essentially at the time of collision with India, not 10–20 Myr later as might be expected if the locus of activity migrated northward as India penetrated the rest of Eurasia. Thus, the north-south dimensions of the Tibetan Plateau were set mainly by differences in lithospheric strength, with strong lithosphere beneath India and the Tarim and Qaidam basins steadily encroaching on one another as the region between them, the present-day Tibetan Plateau, deformed, and its north-south dimension became narrower. Second, abundant evidence calls for acceleration of deformation, including the formation of new faults, in northeastern Tibet since ~15 Ma and a less precisely dated change in orientation of crustal shortening since ~20 Ma. This reorientation of crustal shortening and roughly concurrent outward growth of high terrain, which swings from NNE-SSW in northern Tibet to more NE-SW and even ENE-WSW in the easternmost part of northeastern Tibet, are likely to be, in part, a consequence of crustal thickening within the high Tibetan Plateau reaching a limit, and the locus of continued shortening then migrating to the northeastern and eastern flanks. These changes in rates and orientation also could result from removal of some or all mantle lithosphere and increased gravitational potential energy per unit area and from a weakening of crustal material so that it could flow in response to pressure gradients set by evolving differences in elevation

    Measurement of the inclusive and dijet cross-sections of b-jets in pp collisions at sqrt(s) = 7 TeV with the ATLAS detector

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    The inclusive and dijet production cross-sections have been measured for jets containing b-hadrons (b-jets) in proton-proton collisions at a centre-of-mass energy of sqrt(s) = 7 TeV, using the ATLAS detector at the LHC. The measurements use data corresponding to an integrated luminosity of 34 pb^-1. The b-jets are identified using either a lifetime-based method, where secondary decay vertices of b-hadrons in jets are reconstructed using information from the tracking detectors, or a muon-based method where the presence of a muon is used to identify semileptonic decays of b-hadrons inside jets. The inclusive b-jet cross-section is measured as a function of transverse momentum in the range 20 < pT < 400 GeV and rapidity in the range |y| < 2.1. The bbbar-dijet cross-section is measured as a function of the dijet invariant mass in the range 110 < m_jj < 760 GeV, the azimuthal angle difference between the two jets and the angular variable chi in two dijet mass regions. The results are compared with next-to-leading-order QCD predictions. Good agreement is observed between the measured cross-sections and the predictions obtained using POWHEG + Pythia. MC@NLO + Herwig shows good agreement with the measured bbbar-dijet cross-section. However, it does not reproduce the measured inclusive cross-section well, particularly for central b-jets with large transverse momenta.Comment: 10 pages plus author list (21 pages total), 8 figures, 1 table, final version published in European Physical Journal

    Jet energy measurement with the ATLAS detector in proton-proton collisions at root s=7 TeV

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    The jet energy scale and its systematic uncertainty are determined for jets measured with the ATLAS detector at the LHC in proton-proton collision data at a centre-of-mass energy of √s = 7TeV corresponding to an integrated luminosity of 38 pb-1. Jets are reconstructed with the anti-kt algorithm with distance parameters R=0. 4 or R=0. 6. Jet energy and angle corrections are determined from Monte Carlo simulations to calibrate jets with transverse momenta pT≄20 GeV and pseudorapidities {pipe}η{pipe}<4. 5. The jet energy systematic uncertainty is estimated using the single isolated hadron response measured in situ and in test-beams, exploiting the transverse momentum balance between central and forward jets in events with dijet topologies and studying systematic variations in Monte Carlo simulations. The jet energy uncertainty is less than 2. 5 % in the central calorimeter region ({pipe}η{pipe}<0. 8) for jets with 60≀pT<800 GeV, and is maximally 14 % for pT<30 GeV in the most forward region 3. 2≀{pipe}η{pipe}<4. 5. The jet energy is validated for jet transverse momenta up to 1 TeV to the level of a few percent using several in situ techniques by comparing a well-known reference such as the recoiling photon pT, the sum of the transverse momenta of tracks associated to the jet, or a system of low-pT jets recoiling against a high-pT jet. More sophisticated jet calibration schemes are presented based on calorimeter cell energy density weighting or hadronic properties of jets, aiming for an improved jet energy resolution and a reduced flavour dependence of the jet response. The systematic uncertainty of the jet energy determined from a combination of in situ techniques is consistent with the one derived from single hadron response measurements over a wide kinematic range. The nominal corrections and uncertainties are derived for isolated jets in an inclusive sample of high-pT jets. Special cases such as event topologies with close-by jets, or selections of samples with an enhanced content of jets originating from light quarks, heavy quarks or gluons are also discussed and the corresponding uncertainties are determined. © 2013 CERN for the benefit of the ATLAS collaboration

    Observation of associated near-side and away-side long-range correlations in √sNN=5.02  TeV proton-lead collisions with the ATLAS detector

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    Two-particle correlations in relative azimuthal angle (Δϕ) and pseudorapidity (Δη) are measured in √sNN=5.02  TeV p+Pb collisions using the ATLAS detector at the LHC. The measurements are performed using approximately 1  Όb-1 of data as a function of transverse momentum (pT) and the transverse energy (ÎŁETPb) summed over 3.1<η<4.9 in the direction of the Pb beam. The correlation function, constructed from charged particles, exhibits a long-range (2<|Δη|<5) “near-side” (Δϕ∌0) correlation that grows rapidly with increasing ÎŁETPb. A long-range “away-side” (Δϕ∌π) correlation, obtained by subtracting the expected contributions from recoiling dijets and other sources estimated using events with small ÎŁETPb, is found to match the near-side correlation in magnitude, shape (in Δη and Δϕ) and ÎŁETPb dependence. The resultant Δϕ correlation is approximately symmetric about π/2, and is consistent with a dominant cos⁥2Δϕ modulation for all ÎŁETPb ranges and particle pT
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