4,514 research outputs found

    A primary electron beam facility at CERN

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    This paper describes the concept of a primary electron beam facility at CERN, to be used for dark gauge force and light dark matter searches. The electron beam is produced in three stages: A Linac accelerates electrons from a photo-cathode up to 3.5 GeV. This beam is injected into the Super Proton Synchrotron, SPS, and accelerated up to a maximum energy of 16 GeV. Finally, the accelerated beam is slowly extracted to an experiment, possibly followed by a fast dump of the remaining electrons to another beamline. The beam parameters are optimized using the requirements of the Light Dark Matter eXperiment (LDMX) as benchmark.Comment: 3 pages, 3 figure

    As a Matter of Factions: The Budgetary Implications of Shifting Factional Control in Japan’s LDP

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    For 38 years, the Liberal Democratic Party (LDP) maintained single-party control over the Japanese government. This lack of partisan turnover in government has frustrated attempts to explain Japanese government policy changes using political variables. In this paper, we look for intraparty changes that may have led to changes in Japanese budgetary policy. Using a simple model of agenda-setting, we hypothesize that changes in which intraparty factions “control” the LDP affect the party’s decisions over spending priorities systematically. This runs contrary to the received wisdom in the voluminous literature on LDP factions, which asserts that factions, whatever their raison d’ĂȘtre, do not exhibit different policy preferences. We find that strong correlations do exist between which factions comprise the agenda-setting party “mainstream” and how the government allocates spending across pork-barrel and public goods items

    Von Willebrand factor propeptide as a marker of disease activity in systemic sclerosis (scleroderma)

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    In 44 consecutive patients with systemic sclerosis (SSc), plasma concentrations of von Willebrand factor (vWf) were higher than those of the vWf propeptide, but the propeptide showed less variability within patient subgroups. Higher values of the propeptide were observed in patients with early pulmonary involvement. A closer correlation of the propeptide than of vWf to biochemical markers of activity was also evident. Our results suggest that the propeptide, despite a shorter circulating half-time and lower plasma concentrations than vWf, is more useful in the assessment of disease activity in SSc

    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

    Long-term ecological legacies in western Amazonia

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    M.B.B would like to acknowledge funding from the National Science Foundation (grant nos. EAR1338694 and BCS0926973), the Belmont Forum, and the National Aeronautics and Space Administration (grant no. NNX14AD31G). C.N.H.M would like to acknowledge funding from the European Research Council (ERC 2019 StG 853394). C.N.H.M and M.F.R would like to acknowledge funding from the Netherlands Organisation for Scientific Research (ALWOP.322). S.N.H, M.P, and Jo.V performed this research as a part of the BSc research program of the Institute for Biodiversity and Ecosystem Dynamics at the University of Amsterdam.1. Modifications of Amazonian forests by pre‐Columbian peoples are thought to have left ecological legacies that have persisted to the modern day. Most Amazonian palaeoecological records do not, however, provide the required temporal resolution to document the nuanced changes of pre‐Columbian disturbance or post‐disturbance succession and recovery, making it difficult to detect any direct, or indirect, ecological legacies on tree species. 2. Here, we investigate the fossil pollen, phytolith and charcoal history of Lake Kumpaka, Ecuador, during the last 2,415 years in c. 3–50 year time intervals to assess ecological legacies resulting from pre‐Columbian forest modification, disturbance, cultivation and fire usage. 3. Two cycles of pre‐Columbian cultivation (one including slash‐and‐burn cultivation, the other including slash‐and‐mulch cultivation) were documented in the record around 2150–1430 cal. year BP and 1250–680 cal. year BP, with following post‐disturbance succession dynamics. Modern disturbance was documented after c. 10 cal. year BP. The modern disturbance produced a plant composition unlike those of the two past disturbances, as fire frequencies reached their peak in the 2,415‐year record. The disturbance periods varied in intensity and duration, while the overturn of taxa following a disturbance lasted for hundreds of years. The recovery periods following pre‐Columbian disturbance shared some similar patterns of early succession, but the longer‐term recovery patterns differed. 4. Synthesis. The trajectories of change after a cessation of cultivation can be anticipated to differ depending on the intensity, scale, duration and manner of the past disturbance. In the Kumpaka record, no evidence of persistent enrichment or depletion of intentionally altered taxa (i.e. direct legacy effects) was found but indirect legacy effects, however, were documented and have persisted to the modern day. These findings highlight the strengths of using empirical data to reconstruct past change rather than relying solely on modern plant populations to infer past human management and ecological legacies, and challenge some of the current hypotheses involving the persistence of pre‐Columbian legacies on modern plant populations.Publisher PDFPeer reviewe

    Simulated retreat of Jakobshavn IsbrĂŠ since the Little Ice Age controlled by geometry

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    Rapid retreat of Greenland's marine-terminating glaciers coincides with regional warming trends, which have broadly been used to explain these rapid changes. However, outlet glaciers within similar climate regimes experience widely contrasting retreat patterns, suggesting that the local fjord geometry could be an important additional factor. To assess the relative role of climate and fjord geometry, we use the retreat history of Jakobshavn Isbré, West Greenland, since the Little Ice Age (LIA) maximum in 1850 as a baseline for the parameterization of a depth- and width-integrated ice flow model. The impact of fjord geometry is isolated by using a linearly increasing climate forcing since the LIA and testing a range of simplified geometries.We find that the total length of retreat is determined by external factors – such as hydrofracturing, submarine melt and buttressing by sea ice – whereas the retreat pattern is governed by the fjord geometry. Narrow and shallow areas provide pinning points and cause delayed but rapid retreat without additional climate warming, after decades of grounding line stability. We suggest that these geometric pinning points may be used to locate potential sites for moraine formation and to predict the long-term response of the glacier. As a consequence, to assess the impact of climate on the retreat history of a glacier, each system has to be analyzed with knowledge of its historic retreat and the local fjord geometry.</p

    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

    The influence of wind direction on the capture of the wood warbler (Phylloscopus sibilatrix), an uncommon migratory species in the western Mediterranean

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    The wood warbler (Phylloscopus sibilatrix) is a migratory species in the western Mediterranean wintering in the Gulf of Guinea region, West Africa. In autumn and spring, this species, along with the populations breeding in Ireland and Britain, uses the Italian peninsula as its main axis of migration. From the data of captured birds at several ringing stations in the western Mediterranean (Balearic Islands and coastal Iberian Peninsula), we analyzed capture rates of the species during spring migration from 1993 to 2007. Based on the selection of days with a significant number of captures and those without captures, we analyzed the effect of wind direction over the western Mediterranean to determine a relationship between winds and the number of captures. From a total of 663 wood warblers captured between 1993 and 2007, a total of 31 days have been selected as significant days with a high number of captures, and 31 days have been selected as no-capture days. On days of maximum captures, winds coming from an easterly direction, i.e. Algeria and Tunisia, were dominant, indicating days with a clear eastern component. Contrary to expected results, captures were also made on days when the wind direction was predominantly from a northerly direction. Analysis of the origin of the winds in north eastern Spain (western Mediterranean) revealed that the majority of northerly winds originated from Africa and not from Europe as is usual for this region. Days or periods selected as no-capture days were characterized by winds coming from a northerly (European origin) or westerly direction
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