1,738 research outputs found

    Within-Event Spatially Distributed Bedload: Linking Fluvial Sediment Transport to Morphological Change

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    Maps of apparent bedload velocity are presented along with maps of associated channel change. Apparent bedload velocity is the bias in acoustic Doppler current profiler (aDcp) bottom track (Doppler sonar) due to near-bed particle motion (Rennie et al. 2002). The apparent bedload velocity is correlated to bedload transport (Rennie and Villard 2004), and thus serves as an indicator of local bedload transport. Spatially distributed aDcp surveys in a river reach can be used to generate maps of channel bathymetry, water velocity, bed shear stress, and apparent bedload velocity (Rennie and Church 2010). It is possible to relate the observed spatial patterns of bedload and forcing flow. In this paper, the technique is used to measure bedload flux pathways during two sequential aDcp spatial surveys conducted in a Rees River, New Zealand braid bar diffluence-confluence before and after a major flood event that inundated the entire braid plain. The aDcp surveys were complemented with terrestrial laser scans (TLS) of the bar topography. Linking aDcp bathymetry and TLS topography allowed for generation of complete digitial elevation models (DEMs) of the reach, from which morphological change between surveys were determined. Most intriguingly, the primary bedload pathway observed during the first survey resulted in sufficient deposition during the major flood event to fill and choke off an anabranch. This is perhaps the first direct field measurement of spatially distributed bedload and corresponding morphological change

    Loss of the homeostatic protein BPIFA1, leads to exacerbation of otitis media severity in the Junbo mouse model

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    Otitis Media (OM) is characterized by epithelial abnormalities and defects in innate immunity in the middle ear (ME). Although, BPIFA1, a member of the BPI fold containing family of putative innate defence proteins is abundantly expressed by the ME epithelium and SNPs in Bpifa1 have been associated with OM susceptibility, its role in the ME is not well characterized. We investigated the role of BPIFA1 in protection of the ME and the development of OM using murine models. Loss of Bpifa1 did not lead to OM development. However, deletion of Bpifa1 in Evi1Jbo/+mice, a model of chronic OM, caused significant exacerbation of OM severity, thickening of the ME mucosa and increased collagen deposition, without a significant increase in pro-inflammatory gene expression. Our data suggests that BPIFA1 is involved in maintaining homeostasis within the ME under steady state conditions and its loss in the presence of inflammation, exacerbates epithelial remodelling leading to more severe OM

    Gluon Propagator on Coarse Lattices in Laplacian Gauges

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    The Laplacian gauge is a nonperturbative gauge fixing that reduces to Landau gauge in the asymptotic limit. Like Landau gauge, it respects Lorentz invariance, but it is free of Gribov copies; the gauge fixing is unambiguous. In this paper we study the infrared behavior of the lattice gluon propagator in Laplacian gauge by using a variety of lattices with spacings from a=0.125a = 0.125 to 0.35 fm, to explore finite volume and discretization effects. Three different implementations of the Laplacian gauge are defined and compared. The Laplacian gauge propagator has already been claimed to be insensitive to finite volume effects and this is tested on lattices with large volumes.Comment: RevTex 4.0, 14 pages, 9 colour figures; Correction to Reference

    Rotating black hole orbit functionals in the frequency domain

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    In many astrophysical problems, it is important to understand the behavior of functions that come from rotating (Kerr) black hole orbits. It can be particularly useful to work with the frequency domain representation of those functions, in order to bring out their harmonic dependence upon the fundamental orbital frequencies of Kerr black holes. Although, as has recently been shown by W. Schmidt, such a frequency domain representation must exist, the coupled nature of a black hole orbit's rr and θ\theta motions makes it difficult to construct such a representation in practice. Combining Schmidt's description with a clever choice of timelike coordinate suggested by Y. Mino, we have developed a simple procedure that sidesteps this difficulty. One first Fourier expands all quantities using Mino's time coordinate λ\lambda. In particular, the observer's time tt is decomposed with λ\lambda. The frequency domain description is then built from the λ\lambda-Fourier expansion and the expansion of tt. We have found this procedure to be quite simple to implement, and to be applicable to a wide class of functionals. We test the procedure using a simple test function, and then apply it in a particularly interesting case, the Weyl curvature scalar ψ4\psi_4 used in black hole perturbation theory.Comment: 16 pages, 2 figures. Submitted to Phys Rev D. New version gives a vastly improved algorithm due to Drasco for computing the Fourier transforms. Drasco has been added as an author. Also fixed some references and exterminated a small herd of typos; final published versio

    Unconventional carrier-mediated ferromagnetism above room temperature in ion-implanted (Ga, Mn)P:C

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    Ion implantation of Mn ions into hole-doped GaP has been used to induce ferromagnetic behavior above room temperature for optimized Mn concentrations near 3 at.%. The magnetism is suppressed when the Mn dose is increased or decreased away from the 3 at.% value, or when n-type GaP substrates are used. At low temperatures the saturated moment is on the order of one Bohr magneton, and the spin wave stiffness inferred from the Bloch-law T^3/2 dependence of the magnetization provides an estimate Tc = 385K of the Curie temperature that exceeds the experimental value, Tc = 270K. The presence of ferromagnetic clusters and hysteresis to temperatures of at least 330K is attributed to disorder and proximity to a metal-insulating transition.Comment: 4 pages, 4 figures (RevTex4

    Theory and Phenomenology of Hadrons

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    This Dyson-Schwinger equation (DSE) aperc,u highlights recent applications to mesons. It reports features of, and results for, pseudoscalar and scalar bound-state residues in vacuum polarisations, and exhibits how a restoration of chiral symmetry in meson trajectories could be manifest in a relationship between them. It also touches on nucleon studies, emphasising the importance of both scalar and axial-vector diquark correlations, and reporting the calculation of mu_n G_E^n(Q^2)/G_M^n(Q^2). The value of respecting symmetries, including Poincare' covariance, is stressed.Comment: 7 pages, 1 figure, contribution to proceedings of "18th International IUPAP Conference on Few-Body Problems in Physics," Santos, Brazil, August 21-26, 200

    The use, quality and effectiveness of pelvic examination in primary care for the detection of gynaecological cancer : a systematic review

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    Background Urgent suspected cancer referral guidelines recommend that women with gynaecological cancer symptoms should have a pelvic examination (PE) prior to referral. We do not know to what extent GPs comply, their competency at PE, or if PE shortens the diagnostic interval. Objectives We conducted a systematic review of the use, quality and effectiveness of PE in primary care for women with suspected gynaecological cancer. Method PRISMA guidelines were followed. Three databases were searched using four terms: PE, primary care, competency and gynaecological cancer. Citation lists of all identified papers were screened independently for eligibility by two reviewers. Data extraction was performed in duplicate and independently. Paper quality was assessed using the relevant Critical Appraisal Skills Programme checklist. Emergent themes and contrasting issues were explored in a narrative ecological synthesis. Main Findings Twenty papers met the inclusion criteria. 52% or less of women with suspicious symptoms had a PE. No papers directly explored GPs’ competence at performing PE. Pre-referral PE was associated with reduced diagnostic delay and earlier stage diagnosis. Ecological synthesis demonstrated a complex interplay between patient and practitioner factors and the environment in which examination is performed. Presenting symptoms are commonly misattributed by patients and practitioners resulting in misdiagnosis and lack of PE. Conclusion We do not know if pre-referral PE leads to better outcomes for patients. PE is often not performed for women with gynaecological cancer symptoms, and evidence that it may result in earlier stage of diagnosis is weak. More research is needed

    Women, anger, and aggression an interpretative phenomenological analysis

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    This study reports a qualitative phenomenological investigation of anger and anger-related aggression in the context of the lives of individual women. Semistructured interviews with five women are analyzed using interpretative phenomenological analysis. This inductive approach aims to capture the richness and complexity of the lived experience of emotional life. In particular, it draws attention to the context-dependent and relational dimension of angry feelings and aggressive behavior. Three analytic themes are presented here: the subjective experience of anger, which includes the perceptual confusion and bodily change felt by the women when angry, crying, and the presence of multiple emotions; the forms and contexts of aggression, paying particular attention to the range of aggressive strategies used; and anger as moral judgment, in particular perceptions of injustice and unfairness. The authors conclude by examining the analytic observations in light of phenomenological thinking

    Outcomes of hospital admissions among frail older people: a 2-year cohort study

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    Background ‘Frailty crises’ are a common cause of hospital admission among older people and there is significant focus on admission avoidance. However, identifying frailty before a crisis occurs is challenging, making it difficult to effectively target community services. Better longer-term outcome data are needed if services are to reflect the needs of the growing population of older people with frailty. Aim To determine long-term outcomes of older people discharged from hospital following short (<72 hours) and longer hospital admissions compared by frailty status. Design and setting Two populations aged ≥70 years discharged from hospital units: those following short ‘ambulatory’ admissions (<72 hours) and those following longer inpatient stays. Method Data for 2-year mortality and hospital use were compared using frailty measures derived from clinical and hospital data. Results Mortality after 2 years was increased for frail compared with non-frail individuals in both cohorts. Patients in the ambulatory cohort classified as frail had increased mortality (Rockwood hazard ratio 2.3 [95% confidence interval {CI} = 1.5 to 3.4]) and hospital use (Rockwood rate ratio 2.1 [95% CI = 1.7 to 2.6]) compared with those patients classified as non-frail. Conclusion Individuals with frailty who are discharged from hospital experience increased mortality and resource use, even after short ‘ambulatory’ admissions. This is an easily identifiable group that is at increased risk of poor outcomes. Health and social care systems might wish to examine their current care response for frail older people discharged from hospital. There may be value in a ‘secondary prevention’ approach to frailty crises targeting individuals who are discharged from hospital

    COSMOGRAIL: XVII. Time delays for the quadruply imaged quasar PG 1115+080

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    Indexación: Scopus.Acknowledgements. The authors would like to thank R. Gredel for his help in setting up the program at the ESO MPIA 2.2 m telescope, and the anonymous referee for his or her comments on this work. This work is supported by the Swiss National Fundation. This research made use of Astropy, a community-developed core Python package for Astronomy (Astropy Collaboration et al. 2013, 2018) and the 2D graphics environment Matplotlib (Hunter 2007). K.R. acknowledge support from PhD fellowship FIB-UV 2015/2016 and Becas de Doctorado Nacional CONICYT 2017 and thanks the LSSTC Data Science Fellowship Program, her time as a Fellow has benefited this work. M.T. acknowledges support by the DFG grant Hi 1495/2-1. G. C.-F. C. acknowledges support from the Ministry of Education in Taiwan via Government Scholarship to Study Abroad (GSSA). D. C.-Y. Chao and S. H. Suyu gratefully acknowledge the support from the Max Planck Society through the Max Planck Research Group for S. H. Suyu. T. A. acknowledges support by the Ministry for the Economy, Development, and Tourism’s Programa Inicativa Científica Milenio through grant IC 12009, awarded to The Millennium Institute of Astrophysics (MAS).We present time-delay estimates for the quadruply imaged quasar PG 1115+080. Our results are based on almost daily observations for seven months at the ESO MPIA 2.2 m telescope at La Silla Observatory, reaching a signal-to-noise ratio of about 1000 per quasar image. In addition, we re-analyze existing light curves from the literature that we complete with an additional three seasons of monitoring with the Mercator telescope at La Palma Observatory. When exploring the possible source of bias we considered the so-called microlensing time delay, a potential source of systematic error so far never directly accounted for in previous time-delay publications. In 15 yr of data on PG 1115+080, we find no strong evidence of microlensing time delay. Therefore not accounting for this effect, our time-delay estimates on the individual data sets are in good agreement with each other and with the literature. Combining the data sets, we obtain the most precise time-delay estimates to date on PG 1115+080, with Δt(AB) = 8.3+1.5 -1.6 days (18.7% precision), Δt(AC) = 9.9+1.1 -1.1 days (11.1%) and Δt(BC) = 18.8+1.6 -1.6 days (8.5%). Turning these time delays into cosmological constraints is done in a companion paper that makes use of ground-based Adaptive Optics (AO) with the Keck telescope. © ESO 2018.https://www.aanda.org/articles/aa/abs/2018/08/aa33287-18/aa33287-18.htm
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