4,414 research outputs found

    Behavior of the diffractive cross section in hadron-nucleus collisions

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    A phenomenological analysis of diffractive dissociation of nuclei in proton-nucleus and meson-nucleus collisions is presented. The theoretical approach employed here is able to take into account at once data of the HELIOS and EHS/NA22 collaborations that exhibit quite different atomic mass dependences. Possible extensions of this approach to hard diffraction in nuclear processes are also discussed.Comment: 5 pages, 2 figure

    Subtrochanteric fractures after long-term treatment with bisphosphonates: a European Society on Clinical and Economic Aspects of Osteoporosis and Osteoarthritis, and International Osteoporosis Foundation Working Group Report

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    Summary: This paper reviews the evidence for an association between atypical subtrochanteric fractures and long-term bisphosphonate use. Clinical case reports/reviews and case-control studies report this association, but retrospective phase III trial analyses show no increased risk. Bisphosphonate use may be associated with atypical subtrochanteric fractures, but the case is yet unproven. Introduction: A Working Group of the European Society on Clinical and Economic Aspects of Osteoporosis and Osteoarthritis and the International Osteoporosis Foundation has reviewed the evidence for a causal association between subtrochanteric fractures and long-term treatment with bisphosphonates, with the aim of identifying areas for further research and providing recommendations for physicians. Methods: A PubMed search of literature from 1994 to May 2010 was performed using key search terms, and articles pertinent to subtrochanteric fractures following bisphosphonate use were analysed. Results: Several clinical case reports and case reviews report a possible association between atypical fractures at the subtrochanteric region of the femur in bisphosphonate-treated patients. Common features of these ‘atypical' fractures include prodromal pain, occurrence with minimal/no trauma, a thickened diaphyseal cortex and transverse fracture pattern. Some small case-control studies report the same association, but a large register-based study and retrospective analyses of phase III trials of bisphosphonates do not show an increased risk of subtrochanteric fractures with bisphosphonate use. The number of atypical subtrochanteric fractures in association with bisphosphonates is an estimated one per 1,000 per year. It is recommended that physicians remain vigilant in assessing their patients treated with bisphosphonates for the treatment or prevention of osteoporosis and advise patients of the potential risks. Conclusions: Bisphosphonate use may be associated with atypical subtrochanteric fractures, but the case is unproven and requires further research. Were the case to be proven, the risk-benefit ratio still remains favourable for use of bisphosphonates to prevent fracture

    Probing the Rho Spectral Function in Hot and Dense Nuclear Matter by Dileptons

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    We present a dynamical study of e+ee^+e^- and μ+μ\mu^+ \mu^- production in proton-nucleus and nucleus-nucleus collisions at CERN-SPS energies on the basis of the covariant transport approach HSD employing a momentum-dependent ρ\rho-meson spectral function that includes the pion modifications in the nuclear medium as well as the polarization of the ρ\rho-meson due to resonant ρ\rhoN-N scattering. We find that the experimental data from the CERES and HELIOS-3 Collaborations can be described equally well as within the dropping ρ\rho-mass scenario. Whereas corresponding dilepton qTq_T-spectra are found to be very similar, the inclusive dilepton yield in the invariant mass range 0.85M1.00.85 \leq M \leq 1.0 GeV should allow to disentangle the two scenarios experimentally.Comment: 13 pages RevTeX slightly revised, 6 eps-figure

    Hip fracture, mortality risk, and cause of death over two decades

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    Summary: Men and women with hip fracture have higher short-term mortality. This study investigated mortality risk over two decades post-fracture; excess mortality remained high in women up to 10 years and in men up to 20 years. Cardiovascular disease (CVD) and pneumonia were leading causes of death with a long-term doubling of risk. Introduction: Hip fractures are associated with increased mortality, particularly short term. In this study with a two-decade follow-up, we examined mortality and cause of death compared to the background population. Methods: We followed 1013 hip fracture patients and 2026 matched community controls for 22 years. Mortality, excess mortality, and cause of death were analyzed and stratified for age and sex. Hazard ratio (HR) was estimated by Cox regression. A competing risk model was fitted to estimate HR for common causes of death (CVD, cancer, pneumonia) in the short and long term (>1 year). Results: For both sexes and at all ages, mortality was higher in hip fracture patients across the observation period with men losing most life years (p <0.001). Mortality risk was higher for up to 15 years (women (risk ratio (RR) 1.9 [95 % confidence interval (CI) 1.7–2.1]); men (RR 2.8 [2.2–3.5])) and until end of follow-up ((RR 1.8 [1.6–2.0]); (RR 2.7 [2.1–3.3])). Excess mortality by time intervals, censored for the first year, was evident in women (80 years, for 5 years) and in me

    Correction to: The intake of flavonoids, stilbenes, and tyrosols, mainly consumed through red wine and virgin olive oil, is associated with lower carotid and femoral subclinical atherosclerosis and coronary calcium

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    The original version of this article unfortunately contained a mistake. The author’s name Henry Montero-Salazar was incorrectly written as Henry Montero Salazar. © The Author(s) 2022

    Soft Photoproduction Physics

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    Several topics of interest in soft photoproduction physics are discussed. These include jet universality issues (particle flavour composition), the subdivision into event classes, the buildup of the total photoproduction cross section and the effects of multiple interactions.Comment: 10 pages, LaTeX2e, no figures, to appear in the proceedings of the Durham Workshop on HERA Physics, ``Proton, Photon and Pomeron Structure'', 17--23 September 1995, Durham, U.

    Anthropogenic and climatic impacts on a coastal environment in the Baltic Sea over the last 1000 years

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    Coastal environments have experienced large ecological changes as a result of human activities over the last 100-200 years. To understand the severity and potential consequences of such changes, paleoenvironmental records provide important contextual information. The Baltic Sea coastal zone is naturally a vulnerable system and subject to significant human-induced impacts. To put the recent environmental degradation in the Baltic coastal zone into a long-term perspective, and to assess the natural and anthropogenic drivers of environmental change, we present sedimentary records covering the last 1000 years obtained from a coastal inlet (Gasfjarden) and a nearby lake (Lake Storsjon) in Sweden. We investigate the links between a pollen-based land cover reconstruction from Lake Storsjon and paleoenvironmental variables from Gasfjarden itself, including diatom assemblages, organic carbon (C) and nitrogen (N) contents, stable C and N isotopic ratios, and biogenic silica contents. The Lake Storsjon record shows that regional land use was characterized by small-scale agricultural activity between 900 and 1400 CE, which slightly intensified between 1400 and 1800 CE. Substantial expansion of cropland was observed between 1800 and 1950 CE, before afforestation between 1950 and 2010 CE. From the Gasfjarden record, prior to 1800 CE, relatively minor changes in the diatom and geochemical proxies were found. The onset of cultural eutrophication in Gasfjarden can be traced to the 1800s and intensified land use is identified as the main driver. Anthropogenic activities in the 20th century have caused unprecedented ecosystem changes in the coastal inlet, as reflected in the diatom composition and geochemical proxies. (c) 2018 Elsevier Ltd. All rights reserved.Peer reviewe

    Pervasive cold ice within a temperate glacier-implications for glacier thermal regimes, sediment transport and foreland geomorphology

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    © Author(s) 2019. Published by Copernicus Publications on behalf of the European Geosciences Union.This study suggests that cold-ice processes may be more widespread than previously assumed, even within temperate glacial systems. We present the first systematic mapping of cold ice at the snout of the temperate glacier Midtdalsbreen, an outlet of the Hardangerjøkulen icefield (Norway), from 43 line kilometres of ground-penetrating radar data. Results show a 40 m wide cold-ice zone within the majority of the glacier snout, where ice thickness is <10 m. We interpret ice to be cold-based across this zone, consistent with basal freeze-on processes involved in the deposition of moraines. We also find at least two zones of cold ice up to 15 m thick within the ablation area, occasionally extending to the glacier bed. There are two further zones of cold ice up to 30 m thick in the accumulation area, also extending to the glacier bed. Cold-ice zones in the ablation area tend to correspond to areas of the glacier that are covered by late-lying seasonal snow patches that reoccur over multiple years. Subglacial topography and the location of the freezing isotherm within the glacier and underlying subglacial strata likely influence the transport and supply of supraglacial debris and formation of controlled moraines. The wider implication of this study is the possibility that, with continued climate warming, temperate environments with primarily temperate glaciers could become polythermal in forthcoming decades with (i) persisting thinning and (ii) retreat to higher altitudes where subglacial permafrost could be and/or become more widespread. Adversely, the number and size of late-lying snow patches in ablation areas may decrease and thereby reduce the extent of cold ice, reinforcing the postulated change in the thermal regime.Peer reviewedFinal Published versio

    Aspects of four-jet production in polarized proton-proton collisions

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    We examine the intrinsic spin-dependence of the dominant gggggggg \rightarrow gggg subprocess contribution to four-jet production in polarized proton-proton collisions using helicity amplitude techniques. We find that the partonic level, longitudinal spin-spin asymmetry, a^LL\hat{a}_{LL}, is intrinsically large in the kinematic regions probed in experiments detecting four isolated jets. Such events may provide another qualitative or semi-quantitative test of the spin-structure of QCD in planned polarized pppp collisions at RHIC.Comment: 9 pages, LaTeX, 2 uuencoded postscript files attache
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