1,856 research outputs found

    Local competition and metapopulation processes drive long-term seagrass-epiphyte population dynamics

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    It is well known that ecological processes such as population regulation and natural enemy interactions potentially occur over a range of spatial scales, and there is a substantial body of literature developing theoretical understanding of the interplay between these processes. However, there are comparatively few studies quantifying the long-term effects of spatial scaling in natural ecosystems. A key challenge is that trophic complexity in real-world biological communities quickly obscures the signal from a focal process. Seagrass meadows provide an excellent opportunity in this respect: in many instances, seagrasses effectively form extensive natural monocultures, in which hypotheses about endogenous dynamics can be formulated and tested. We present amongst the longest unbroken, spatially explict time series of seagrass abundance published to date. Data include annual measures of shoot density, total above-ground abundance, and associated epiphyte cover from five Zostera marina meadows distributed around the Isles of Scilly, UK, from 1996 to 2011. We explore empirical patterns at the local and metapopulation scale using standard time series analysis and develop a simple population dynamic model, testing the hypothesis that both local and metapopulation scale feedback processes are important. We find little evidence of an interaction between scales in seagrass dynamics but that both scales contribute approximately equally to observed local epiphyte abundance. By quantifying the long-term dynamics of seagrass-epiphyte interactions we show how measures of density and extent are both important in establishing baseline information relevant to predicting responses to environmental change and developing management plans. We hope that this study complements existing mechanistic studies of physiology, genetics and productivity in seagrass, whilst highlighting the potential of seagrass as a model ecosystem. More generally, this study provides a rare opportunity to test some of the predictions of ecological theory in a natural ecosystem of global conservation and economic val

    Adjuvant high-dose medroxyprogesterone acetate for early breast cancer: 13 years update in a multicentre randomized trial

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    The authors updated their report on a randomized trial initiated in 1982 comparing, in early breast cancer, high-dose IM Medroxyprogesterone acetate (HD-MPA) adjuvant hormonotherapy during 6 months with no hormonotherapy; node-positive patients also received 6 courses of IV CMF (day 1, day 8; q.4 weeks). 246 node-negative (NN) and 270 node-positive (NP) patients had been followed for a median duration of 13 years. Previous results were confirmed in this analysis on mature data. In NN patients, relapse-free survival (RFS) was improved in the adjuvant hormonotherapy arm, regardless of age while overall survival (OAS) was also increased in younger (less then 50 years) patients. In the whole group of NP patients, no difference was seen regarding RFS or OAS. However, an age-dependant opposite effect was observed: younger patients (< 50) experienced a worse and significant outcome of relapse-free and overall survivals when receiving adjuvant HD-MPA while older patients (> = 50) enjoyed a significant improvement of their relapse-free survival. For both NN and NP patients, differences in overall survivals observed in older women with a shorter follow-up, were no longer detected. © 2001 Cancer Research Campaign http://www.bjcancer.co

    The physical oceanography of the transport of floating marine debris

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    Marine plastic debris floating on the ocean surface is a major environmental problem. However, its distribution in the ocean is poorly mapped, and most of the plastic waste estimated to have entered the ocean from land is unaccounted for. Better understanding of how plastic debris is transported from coastal and marine sources is crucial to quantify and close the global inventory of marine plastics, which in turn represents critical information for mitigation or policy strategies. At the same time, plastic is a unique tracer that provides an opportunity to learn more about the physics and dynamics of our ocean across multiple scales, from the Ekman convergence in basin-scale gyres to individual waves in the surfzone. In this review, we comprehensively discuss what is known about the different processes that govern the transport of floating marine plastic debris in both the open ocean and the coastal zones, based on the published literature and referring to insights from neighbouring fields such as oil spill dispersion, marine safety recovery, plankton connectivity, and others. We discuss how measurements of marine plastics (both in situ and in the laboratory), remote sensing, and numerical simulations can elucidate these processes and their interactions across spatio-temporal scales

    Search for the Standard Model Higgs Boson in the Decay Channel H→ZZ→4l in pp Collisions at √s=7  TeV

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    A search for a Higgs boson in the four-lepton decay channel H→ZZ, with each Z boson decaying to an electron or muon pair, is reported. The search covers Higgs boson mass hypotheses in the range of 110100GeV (with 13 below 160GeV), while 67.1±6.0 (9.5±1.3) events are expected from background. The four-lepton mass distribution is consistent with the expectation of standard model background production of ZZ pairs. Upper limits at 95% confidence level exclude the standard model Higgs boson in the ranges of 134-158GeV, 180-305GeV, and 340-465GeV. Small excesses of events are observed around masses of 119, 126, and 320GeV, making the observed limits weaker than expected in the absence of a signal. © 2012 CERN.European Commission; Federal Ministry of Science, Research and Economy (Austria); Agency for Innovation by Science and Technology (Belgium); Conselho Nacional de Desenvolvimento CientĂ­fico e TecnolĂłgico (Brasil); Coordenação de Aperfeiçoamento de Pessoal de NĂ­vel Superior (Brasil); Fundação Carlos Chagas Filho de Amparo Ă  Pesquisa do Estado do Rio de Janeiro; Fundação de Amparo Ă  Pesquisa do Estado de SĂŁo Paulo; Colciencias (Colombia); Ministry of Science, Education and Sports of the Republic of Croatia; Research Promotion Foundation (Cyprus); Centre National de la Recherche Scientifique (France); Bundesministerium fĂŒr Bildung und Forschung (Deutschland); Deutsche Forschungsgemeinschaft; General Secretariat of Research and Technology (Greece); National Office for Research and Technology (Hungary); Institute for Research in Fundamental Sciences (Iran); Science Foundation Ireland; Istituto Nazionale di Fisica Nucleare (Italia); National Research Foundation of Korea; Centro de InvestigaciĂłn y de Estudios Avanzados del Instituto PolitĂ©cnico Nacional (MĂ©xico); Consejo Nacional de Ciencia y TecnologĂ­a (MĂ©xico); SecretarĂ­a de EducaciĂłn PĂșblica (MĂ©xico); Universidad AutĂłnoma de San Luis PotosĂ­; Pakistan Atomic Energy Commission; Fundação para a CiĂȘncia e a Tecnologia (Portugal); Joint Institute for Nuclear Research (Russia); Russian Foundation for Basic Research; Ministry of Education, Science and Technological Development (Serbia); Ministerio de Ciencia e InnovaciĂłn (España); Centro Nacional de FĂ­sica de PartĂ­culas, AstropartĂ­culas y Nuclear (España); Swiss National Science Foundation; The Scientific and Technological Research Council of Turkey; Turkish Atomic Energy Authority; Science and Technology Facilities Council (UK); Department of Energy (US); National Science Foundation (US).Peer Reviewe

    Measurements of inclusive W and Z cross sections in pp collisions at ps = 7 TeV

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    40 pĂĄginas, 8 figuras, 5 tablas.-- Open Access: This article is distributed under the terms of the Creative Commons Attribution Noncommercial License.-- CMS Collaboration: et al.Measurements of inclusive W and Z boson production cross sections in pp collisions at ps = 7 TeV are presented, based on 2:9 pb1 of data recorded by the CMS detector at the LHC. The measurements, performed in the electron and muon decay channels, are combined to give (pp ! WX) B(W ! ` ) = 9:95 0:07 (stat.) 0:28 (syst.) 1:09 (lumi.) nb and (pp ! ZX) B(Z ! `+`) = 0:931 0:026 (stat.) 0:023 (syst.) 0:102 (lumi.) nb, where ` stands for either e or . Theoretical predictions, calculated at the next-to-next-to-leading order in QCD using recent parton distribution functions, are in agreement with the measured cross sections. Ratios of cross sections, which incur an experimental systematic uncertainty of less than 4%, are also reported.This work was supported by the Austrian Federal Ministry of Science and Research; the Belgium Fonds de la Recherche Scienti que, and Fonds voor Wetenschappelijk Onderzoek; the Brazilian Funding Agencies (CNPq, CAPES, FAPERJ, and FAPESP); the Bulgarian Ministry of Education and Science; CERN; the Chinese Academy of Sciences, Ministry of Science and Technology, and National Natural Science Foundation of China; the Colombian Funding Agency (COLCIENCIAS); the Croatian Ministry of Science, Education and Sport; the Research Promotion Foundation, Cyprus; the Estonian Academy of Sciences and NICPB; the Academy of Finland, Finnish Ministry of Education, and Helsinki Institute of Physics; the Institut National de Physique NuclĂ©aire et de Physique des Particules / CNRS, and Commissariat a l'Énergie Atomique, France; the Bundesministerium fĂŒr Bildung und Forschung, Deutsche Forschungsgemeinschaft, and Helmholtz-Gemeinschaft Deutscher Forschungszentren, Germa-ny; the General Secretariat for Research and Technology, Greece; the National Scienti c Research Foundation, and National O ce for Research and Technology, Hungary; the Department of Atomic Energy, and Department of Science and Technology, India; the Institute for Studies in Theoretical Physics and Mathematics, Iran; the Science Foundation, Ireland; the Istituto Nazionale di Fisica Nucleare, Italy; the Korean Ministry of Education, Science and Technology and the World Class University program of NRF, Korea; the Lithuanian Academy of Sciences; the Mexican Funding Agencies (CINVESTAV, CONACYT, SEP, and UASLP-FAI); the Pakistan Atomic Energy Commission; the State Commission for Scienti c Research, Poland; the Fundaçùo para a CiĂȘncia e a Tecnologia, Portugal; JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); the Ministry of Science and Technologies of the Russian Federation, and Russian Ministry of Atomic Energy; the Ministry of Science and Technological Development of Serbia; the Ministerio de Ciencia e InnovaciĂłn, and Programa Consolider- Ingenio 2010, Spain; the Swiss Funding Agencies (ETH Board, ETH Zurich, PSI, SNF, UniZH, Canton Zurich, and SER); the National Science Council, Taipei; the Scienti c and Technical Research Council of Turkey, and Turkish Atomic Energy Authority; the Science and Technology Facilities Council, U.K.; the US Department of Energy, and the US National Science Foundation. Individuals have received support from the Marie-Curie programme and the European Research Council (European Union); the Leventis Foundation; the A. P. Sloan Foundation; the Alexander von Humboldt Foundation; the Associazione per lo Sviluppo Scienti co e Tecnologico del Piemonte (Italy); the Belgian Federal Science Policy Office; the Fonds pour la Formation Ă  la Recherche dans l'Industrie et dans l'Ágriculture (FRIA-Belgium); and the Agentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium).Peer reviewe

    Erratum: Search for anomalous ttÂŻ production in the highly-boosted all-hadronic final state

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    Chatrchyan, S. et al.The uncertainties on the mistagged NTMJ background include the statis- tical uncertainty on the sample after loose selection, to which the mistag probability is applied; the statistical uncertainty on the mistag proba- bility itself, ranging from < 1% at 1 TeV /c 2 to ≈ 10% at 3 TeV /c 2 ; and the systematic uncertainty on the mistag probability application, as de- scribed in section 3.3, which is in the range of 1 to 5% depending on the t ̄ t mass. The total background uncertainty is ≈ 5% for the low-mass region, dominated by the systematic uncertainty, and ≈ 100% for the high-mass region, dominated by statistical uncertainty associated with the sample after loose selection.Peer reviewe

    Measurement of the Λ b cross section and the Λ¯b to Λ b ratio with J/ψΛ decays in pp collisions at s=7 TeV

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    This article is published Open Access at sciencedirect.com. It is distributed under the terms of the Creative Commons Attribution License 3.0.-- Chatrchyan, S. et al.The Λ b differential production cross section and the cross section ratio σ(Λ-b)/σ(Λb) are measured as functions of transverse momentum pTΛb and rapidity |y Λb| in pp collisions at s=7 TeV using data collected by the CMS experiment at the LHC. The measurements are based on Λ b decays reconstructed in the exclusive final state J/ψΛ, with the subsequent decays J/ψ→Ό +ÎŒ - and Λ→pπ, using a data sample corresponding to an integrated luminosity of 1.9 fb -1. The product σ(Λb)×B(Λb→J/ψΛ) versus pTΛb falls faster than that of b mesons. The measured value of σ(Λb)×B(Λb→J/ψΛ) for pTΛb>10 GeV and |y Λb|<2.0 is 1.16±0.06±0.12nb, and the integrated σ(Λ-b)/σ(Λb) ratio is 1.02±0.07±0.09, where the uncertainties are statistical and systematic, respectively. © 2012 CERN.This work was supported by the Austrian Federal Ministry of Science and Research; the Belgium Fonds de la Recherche Scientifique, and Fonds voor Wetenschappelijk Onderzoek; the Brazilian Funding Agencies (CNPq, CAPES, FAPERJ, and FAPESP); the Bulgarian Ministry of Education and Science; CERN; the Chinese Academy of Sciences, Ministry of Science and Technology, and National Natural Science Foundation of China; the Colombian Funding Agency (COLCIENCIAS); the Croatian Ministry of Science, Education and Sport; the Research Promotion Foundation, Cyprus; the Ministry of Education and Research, Recurrent financing contract SF0690030s09 and European Regional Development Fund, Estonia; the Academy of Finland, Finnish Ministry of Education and Culture, and Helsinki Institute of Physics; the Institut National de Physique NuclĂ©aire et de Physique des Particules/CNRS, and Commissariat Ă  l’Énergie Atomique et aux Énergies Alternatives/CEA, France; the Bundesministerium fĂŒr Bildung und Forschung, Deutsche Forschungsgemeinschaft, and HelmholtzGemeinschaft Deutscher Forschungszentren, Germany; the General Secretariat for Research and Technology, Greece; the National Scientific Research Foundation, and National Office for Research and Technology, Hungary; the Department of Atomic Energy and the Department of Science and Technology, India; the Institute for Studies in Theoretical Physics and Mathematics, Iran; the Science Foundation, Ireland; the Istituto Nazionale di Fisica Nucleare, Italy; the Korean Ministry of Education, Science and Technology and the World Class University program of NRF, Korea; the Lithuanian Academy of Sciences; the Mexican Funding Agencies (CINVESTAV, CONACYT, SEP, and UASLP-FAI); the Ministry of Science and Innovation, New Zealand; the Pakistan Atomic Energy Commission; the Ministry of Science and Higher Education and the National Science Centre, Poland; the Fundação para a CiĂȘncia e a Tecnologia, Portugal; JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); the Ministry of Education and Science of the Russian Federation, the Federal Agency of Atomic Energy of the Russian Federation, Russian Academy of Sciences, and the Russian Foundation for Basic Research; the Ministry of Science and Technological Development of Serbia; the Ministerio de Ciencia e InnovaciĂłn, and Programa Consolider-Ingenio 2010, Spain; the Swiss Funding Agencies (ETH Board, ETH Zurich, PSI, SNF, UniZH, Canton Zurich, and SER); the National Science Council, Taipei; the Scientific and Technical Research Council of Turkey, and Turkish Atomic Energy Authority; the Science and Technology Facilities Council, UK; the US Department of Energy, and the US National Science Foundation. Individuals have received support from the Marie-Curie programme and the European Research Council (European Union); the Leventis Foundation; the A.P. Sloan Foundation; the Alexander von Humboldt Foundation; the Belgian Federal Science Policy Office; the Fonds pour la Formation Ă  la Recherche dans l’Industrie et dans l’Agriculture (FRIA – Belgium); the Agentschap voor Innovatie door Wetenschap en Technologie (IWT – Belgium); the Council of Science and Industrial Research, India; and the HOMING PLUS programme of Foundation for Polish Science, cofinanced from European Union, Regional Development Fund.Peer Reviewe

    Search for a heavy bottom-like quark in pp collisions at √s = 7 TeV

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    20 páginas, 3 figuras, 2 tablas.-- Open access: This article is distributed under the terms of the Creative Commons Attribution License 3.0.-- CMS Collaboration: et al.A search for pair-produced bottom-like quarks in pp collisions at √s = 7 TeV is conducted with the CMS experiment at the LHC. The decay b' →tW is considered in this search. The b' ¯b' →tW−¯tW+ process can be identified by the distinctive signature of trileptons and same-sign dileptons. With a data sample corresponding to an integrated luminosity of 34 pb−1, no excess above the standard model background predictions is observed and a b' quark with a mass between 255 and 361 GeV/c2 is excluded at the 95% confidence level.Acknowledge support from: FMSR (Austria); FNRS and FWO (Belgium); CNPq, CAPES, FAPERJ, and FAPESP (Brazil); MES (Bulgaria); CERN; CAS, MoST, and NSFC (China); COLCIENCIAS (Colombia); MSES (Croatia); RPF (Cyprus); Academy of Sciences and NICPB (Estonia); Academy of Finland, ME, and HIP (Finland); CEA and CNRS/IN2P3 (France); BMBF, DFG, and HGF (Germany); GSRT (Greece); OTKA and NKTH (Hungary); DAE and DST (India); IPM (Iran); SFI (Ireland); INFN (Italy); NRF and WCU (Korea); LAS (Lithuania); CINVESTAV, CONACYT, SEP, and UASLPFAI (Mexico); PAEC (Pakistan); SCSR (Poland); FCT (Portugal); JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); MST and MAE (Russia); MSTD (Serbia); MICINN and CPAN (Spain); Swiss Funding Agencies (Switzerland); NSC (Taipei); TUBITAK and TAEK (Turkey); STFC (United Kingdom); DOE and NSF (USA).Peer reviewe

    Measurement of the inclusive W and Z production cross sections in pp collisions at ps = 7TeV with the CMS experiment

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    76 pĂĄginas, 29 figuras, 20 tablas.-- Open Access: This article is distributed under the terms of the Creative Commons Attribution Noncommercial License.-- CMS Collaboration: et al.A measurement of inclusive W and Z production cross sections in pp collisions at ps = 7TeV is presented. The electron and muon decay channels are analyzed in a data sample collected with the CMS detector at the LHC and corresponding to an integrated luminosity of 36 pb-1. The measured inclusive cross sections are (pp - WX) B(W - lv) = 10:31 0:02 (stat:) 0:09 (syst:) 0:10 (th:) 0:41 (lumi:) nb and (pp - ZX) B(Z - l+l-) = 0:974 0:007 (stat:) 0:007 (syst:) 0:018 (th:) 0:039 (lumi:) nb, limited to the dilepton invariant mass range 60 to 120 GeV. The luminosity-independent cross section ratios are ( (pp - WX) * B(W - lv)) / ( (pp - ZX) * B(Z - l+l-)) = 10:54 0:07 (stat:) 0:08 (syst:) 0:16 (th:) and ( (pp - W+X) B(W+ - l+v )) / ( (pp ! W-X) B(W- ! l-v)) = 1:421 0:006 (stat:) 0:014 (syst:) 0:029 (th:). The measured values agree with next-to-next-to-leading order QCD cross section calculations based on recent parton distribution functions.This work was supported by the Austrian Federal Ministry of Science and Research; the Belgium Fonds de la Recherche Scienti que, and Fonds voor Wetenschappelijk Onderzoek; the Brazilian Funding Agencies (CNPq, CAPES, FAPERJ, and FAPESP); the Bulgarian Ministry of Education and Science; CERN; the Chinese Academy of Sciences, Ministry of Science and Technology, and National Natural Science Foundation of China; the Colombian Funding Agency (COLCIENCIAS); the Croatian Ministry of Science, Education and Sport; the Research Promotion Foundation, Cyprus; the Estonian Academy of Sciences and NICPB; the Academy of Finland, Finnish Ministry of Education and Culture, and Helsinki Institute of Physics; the Institut National de Physique NuclĂšaire et de Physique des Particules / CNRS, and Commissariat ĂĄ l'Énergie Atomique et aux Énergies Alternatives / CEA, France; the Bundesministerium fĂŒr Bildung und Forschung, Deutsche Forschungsgemeinschaft, and Helmholtz-Gemeinschaft Deutscher Forschungszentren, Germany; the General Secretariat for Research and Technology, Greece; the National Scienti c Research Foundation, and National Office for Research and Technology, Hungary; the Department of Atomic Energy and the Department of Science and Technology, India; the Institute for Studies in Theoretical Physics and Mathematics, Iran; the Science Foundation, Ireland; the Istituto Nazionale di Fisica Nucleare, Italy; the Korean Ministry of Education, Science and Technology and the World Class University program of VESTAV, CONACYT, SEP, and UASLP-FAI); the Ministry of Science and Innovation, New Zealand; the Pakistan Atomic Energy Commission; the State Commission for Scienti c Research, Poland; the Fundaçào para a CiĂšncia e a Tecnologia, Portugal; JINR (Armenia, Belarus, Georgia, Ukraine, Uzbekistan); the Ministry of Science and Technologies of the Russian Federation, the Russian Ministry of Atomic Energy and the Russian Foundation for Basic Research; the Ministry of Science and Technological Development of Serbia; the Ministerio de Ciencia e InnovaciĂłn, and Programa Consolider-Ingenio 2010, Spain; the Swiss Funding Agencies (ETH Board, ETH Zurich, PSI, SNF, UniZH, Canton Zurich, and SER); the National Science Council, Taipei; the Scienti c and Technical Research Council of Turkey, and Turkish Atomic Energy Authority; the Science and Technology Facilities Council, UK; the US Department of Energy, and the US National Science Foundation. Individuals have received support from the Marie-Curie programme and the European Research Council (European Union); the Leventis Foundation; the A. P. Sloan Foundation; the Alexander von Humboldt Foundation; the Associazione per lo Sviluppo Scienti co e Tecnologico del Piemonte (Italy); the Belgian Federal Science Policy Office; the Fonds pour la Formation ĂĄ la Recherche dans l'Industrie et dans l'Agriculture (FRIA-Belgium); the Agentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium); and the Council of Science and Industrial Research, India.Peer reviewe

    Determination of jet energy calibration and transverse momentum resolution in CMS

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    66 páginas, 41 figuras, 1 tabla.-- Open Access.-- CMS Collaboration: et al.Measurements of the jet energy calibration and transverse momentum resolution in CMS are presented, performed with a data sample collected in proton-proton collisions at a centre-of-mass energy of 7TeV, corresponding to an integrated luminosity of 36pb−1. The transverse momentum balance in dijet and γ/Z+jets events is used to measure the jet energy response in the CMS detector, as well as the transverse momentum resolution. The results are presented for three different methods to reconstruct jets: a calorimeter-based approach, the ``Jet-Plus-Track'' approach, which improves the measurement of calorimeter jets by exploiting the associated tracks, and the ``Particle Flow'' approach, which attempts to reconstruct individually each particle in the event, prior to the jet clustering, based on information from all relevant subdetectors.Individuals have received support from the Marie-Curie programme and the European Research Council (European Union); the Leventis Foundation; the A. P. Sloan Foundation; the Alexander von Humboldt Foundation; the Associazione per lo Sviluppo Scientifico e Tecnologico del Piemonte (Italy); the Belgian Federal Science Policy Office; the Fonds pour la Formation `a la Recherche dans l’Industrie et dans l’Agriculture (FRIA-Belgium); the Agentschap voor Innovatie door Wetenschap en Technologie (IWT-Belgium); and the Council of Science and Industrial Research, India.Peer reviewe
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