242 research outputs found

    Beam Test Results of the BTeV Silicon Pixel Detector

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    The results of the BTeV silicon pixel detector beam test carried out at Fermilab in 1999-2000 are reported. The pixel detector spatial resolution has been studied as a function of track inclination, sensor bias, and readout threshold.Comment: 8 pages of text, 8 figures, Proceedings paper of Pixel 2000: International Workshop on Semiconductor Pixel Detectors for Particles and X-Rays, Genova, June 5-8, 200

    Performance of prototype BTeV silicon pixel detectors in a high energy pion beam

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    The silicon pixel vertex detector is a key element of the BTeV spectrometer. Sensors bump-bonded to prototype front-end devices were tested in a high energy pion beam at Fermilab. The spatial resolution and occupancies as a function of the pion incident angle were measured for various sensor-readout combinations. The data are compared with predictions from our Monte Carlo simulation and very good agreement is found.Comment: 24 pages, 20 figure

    Beam Test of BTeV Pixel Detectors

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    The silicon pixel vertex detector is one of the key elements of the BTeV spectrometer. Detector prototypes were tested in a beam at Fermilab. We report here on the measured spatial resolution as a function of the incident angles for different sensor-readout electronics combinations. We compare the results with predictions from our Monte Carlo simulation.Comment: 7 pages, 5 figures, Invited talk given by J.C. Wang at "Vertex 2000, 9th International Workshop on Vertex Detectors", Michigan, Sept 10-15, 2000. To be published in NIM

    Nucleon-nucleon elastic scattering analysis to 2.5 GeV

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    A partial-wave analysis of NN elastic scattering data has been completed. This analysis covers an expanded energy range, from threshold to a laboratory kinetic energy of 2.5 GeV, in order to include recent elastic pp scattering data from the EDDA collaboration. The results of both single-energy and energy-dependent analyses are described.Comment: 23 pages of text. Postscript files for the figures are available from ftp://clsaid.phys.vt.edu/pub/said/n

    Expansion of elevational range in a forest pest: Can parasitoids track their hosts?

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    We are thankful to Karim Senhadji and Ramon Ruiz-Puche for their help during the field work, and to Sara Garcia Morato for her contribution to quantifying rates of parasitism in PPM clutches at the laboratory. Two anonymous referees contributed to improve the manuscript. This study was supported by projects PROPINOL (PN22/2008), GESBOME (P06-RNM-1890) from Junta de Andalucia, REMEDINAL TE-CM (S2018/EMT-4338) from Comunidad de Madrid, ADAPTAMED (LIFE14 CCA/ES/000612) from LIFE program, and GILES (PCIN-2016-150) from the ERANET-LAC H2020 Programme.Gradients in elevation impose changes in environmental conditions, which in turn modulate species distribution and abundance as well as the interactions they maintain. Along the gradient, interacting species (e.g., predators, parasitoids) can respond to changes in different ways. This study aims to investigate how egg parasitism of a forest pest, the pine processionary moth (PPM), Thaumetopoea pityocampa, vary along an elevational gradient (190-2000 m.a.s.l.) in a mountain range of SE Spain, including areas of recent elevational expansion, for a seven years period (2008-2014). We used generalized linear mixed models to ascertain the effect of both elevation and the winter North Atlantic Oscillation (NAO) index (a proxy of interannual climatic conditions) on the rate of parasitism, and the occurrence probabilities of two parasitoid species: a PPM specialist and a generalist species. Since four pine species are stratified along the elevational gradient, we repeated all the analyses separately for lowlands (190-1300 m. a.s.l.) and uplands (1350-2000 m. a.s.l.). Results showed a decrease in both parasitism rate and probability of occurrence of the two main parasitoid species with elevation, although decline was more severe for the specialist species. The effect of elevation was more conspicuous and intense in uplands than in lowlands. Positive NAO winter values, associated with cold and dry winters, reduced the rate of parasitism and the probability of occurrence of the two main parasitoid species-but particularly for the generalist species-as elevation increases. In a context of climate warming, it is crucial to mitigate PPM elevational and latitudinal expansion. Increasing tree diversity at the PPM expansion areas may favor the establishment of parasitoids, which could contribute to synchronizing host- parasitoid interactions and minimize the risk of PPM outbreaks.Junta de Andalucia PN22/2008REMEDINAL TE-CM from Comunidad de Madrid S2018/EMT-4338ADAPTAMED from LIFE program LIFE14 CCA/ES/000612GILES from the ERANET-LAC H2020 Programme PCIN-2016-150Junta de Andalucia P06-RNM-189

    How environmental managers perceive and approach the issue of invasive species: the case of Japanese knotweed s.l. (RhĂŽne River, France)

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    We would like to thank Springer for publishing our article. The final publication is available at http://link.springer.com/article/10.1007%2Fs10530-015-0969-1International audienceStudying the perceptions of stakeholders or interested parties is a good way to better understand behaviours and decisions. This is especially true for the management of invasive species such as Japanese knotweed s.l. This plant has spread widely in the RhĂŽne basin, where signiïŹcant ïŹnancial resources have been devoted to its management. However, no control technique is recognized as being particularly effective. Many uncertainties remain and many documents have been produced by environmental managers to disseminate current knowledge about the plant and its management. This article aims at characterizing the perceptions that environmental managers have of Japanese knotweed s.l. A discourse analysis was conducted on the printed documentation produced about Japanese knotweed s.l. by environmental managers working along the RhĂŽne River (France). The corpus was both qualitatively and quantitatively analysed. The results indicated a diversity of perceptions depending on the type of environmental managers involved, as well as the geographicalareas and scales on which they acted. Whereas some focused on general knowledge relating to the origins and strategies of colonization, others emphasized the diversity and efïŹcacy of the prospective eradication techniques. There is a real interest in implementing targeted actions to meet local issues. To do so, however, these issues must be better deïŹned. This is a challenging task, as it must involve all types of stakeholders

    Economic Impacts of Non-Native Forest Insects in the Continental United States

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    Reliable estimates of the impacts and costs of biological invasions are critical to developing credible management, trade and regulatory policies. Worldwide, forests and urban trees provide important ecosystem services as well as economic and social benefits, but are threatened by non-native insects. More than 450 non-native forest insects are established in the United States but estimates of broad-scale economic impacts associated with these species are largely unavailable. We developed a novel modeling approach that maximizes the use of available data, accounts for multiple sources of uncertainty, and provides cost estimates for three major feeding guilds of non-native forest insects. For each guild, we calculated the economic damages for five cost categories and we estimated the probability of future introductions of damaging pests. We found that costs are largely borne by homeowners and municipal governments. Wood- and phloem-boring insects are anticipated to cause the largest economic impacts by annually inducing nearly 1.7billioninlocalgovernmentexpendituresandapproximately1.7 billion in local government expenditures and approximately 830 million in lost residential property values. Given observations of new species, there is a 32% chance that another highly destructive borer species will invade the U.S. in the next 10 years. Our damage estimates provide a crucial but previously missing component of cost-benefit analyses to evaluate policies and management options intended to reduce species introductions. The modeling approach we developed is highly flexible and could be similarly employed to estimate damages in other countries or natural resource sectors

    Project of an advanced ISOL facility for exotic beams at LNL

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    Abstract In the framework of the European program to define a second generation Radioactive Ion Beam facility, LNL are proposing the construction in the next five–seven years of a specialized national facility for RIB originated by fission fragments produced by secondary neutrons. It consists on a two-accelerator ISOL-type facility to provide intense neutron-rich radioactive ion beams of highest quality, in the range of masses between 80 and 160. The conceptual design is based on a high intensity 50 MeV (100 kW) proton linac as driver and on the availability of the heavy-ion accelerator ALPI as post accelerator. The estimated neutron yield is 2×1014 n/s at 0°, high enough to satisfy the demand for an advanced RIB facility. An intense R&D program on different items is actually in progress in collaboration with other Laboratories and University groups and is moving in a European context
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