193 research outputs found
Landscape design for soil conservation under land use and climate change
International audienceSoils and landscapes evolve simultaneously. Soil evolution is controlled by redistribution and transformation processes influenced by topographic and climatic parameters, with also a major contribution of management strategies. The perennial landscape features have a strong influence on soil spatial distribution (geometry) and soil genesis. Building landscapes which enhance soil resilience to degradation processes and increase soil services appears as a promising way to adapt to forthcoming climatic and land use evolutions. The presentation aims to synthetize major results from a research program nicknamed Landsoil which focused on the evolution of agricultural soils over medium time scales (decades to centuries) in relation to changing conditions of land use and climate. Precise study of the soil 3D organization in three contrasted landscapes (Brittany, Touraine, Languedoc-Roussillon) enabled to link soil redistribution in space to landscape components (field geometry, hedges or ditches network) and their past evolution. A dynamic and high resolution spatial modeling approach was developed coupling erosion processes and soil organic matter evolution and was calibrated over past evolution using dating techniques (Cs137, C14, OSL). The resulting Landsoil model was afterwards applied in a prospective manner under different scenarios of land use and climate change over the 21th century. Indicators of soil vulnerability and soil resilience were defined and tested by the comparison of several prospective scenarios applied on a same landscape and by comparison of the contrasted landscapes
Challenges and innovations for improving the resilience of European agroforestry systems of high nature and cultural value: a stakeholder perspective
Traditional forms of agroforestry are often recognized as exemplar systems that successfully integrate food production, biodiversity conservation and high cultural values. However many traditional agroforestry systems in Europe are in decline or are threatened and the perspectives of local stakeholders on the production, management, socio-economic, and environmental dimensions of such systems are not fully understood. To fill this gap, we present results of participatory research performed with ten stakeholder groups (SG) across Europe to search for solutions to improve the economic and ecological sustainability of High Nature and Cultural Value agroforestry systems (HNCV agroforestry). Stakeholders included both users and beneficiaries of the HNCV agroforestry. First, SGs held open discussions (227 participants) to identify major challenges for the long-term sustainability of HNCV agroforestry. Challenges were classified into production, management, socio-economic and the environment categories. Second, they responded to structured questionnaires (120 respondents) that explored the positive and negative perceptions of 45 possible attributes of HNCV agroforestry. Third, innovative solutions were identified by individual and group discussions to address the four categories of challenge. Challenges were mostly identified for the management and socio-economic categories, but several challenges concerning production and environment were also pinpointed. Besides, solutions matched poorly with the challenges identified, and, while challenges were at some extent common across countries, solutions to address them were more case-specific. The successful implementation of these solutions requires an in-depth understanding of the diversity of socio-cultural and natural contexts of the HNCV agroforestry systems and building bottom-up proposals and collective actions based on this understanding. The sustainability of HNCV agroforestry would be benefited by providing farmers and managers with a financial advantage from the high nature and cultural value of these systems
Les droits disciplinaires des fonctions publiques : « unification », « harmonisation » ou « distanciation ». A propos de la loi du 26 avril 2016 relative à la déontologie et aux droits et obligations des fonctionnaires
The production of tt⟠, W+bb⟠and W+cc⟠is studied in the forward region of protonâproton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98±0.02 fbâ1 . The W bosons are reconstructed in the decays WââÎœ , where â denotes muon or electron, while the b and c quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions.The production of , and is studied in the forward region of proton-proton collisions collected at a centre-of-mass energy of 8 TeV by the LHCb experiment, corresponding to an integrated luminosity of 1.98 0.02 \mbox{fb}^{-1}. The bosons are reconstructed in the decays , where denotes muon or electron, while the and quarks are reconstructed as jets. All measured cross-sections are in agreement with next-to-leading-order Standard Model predictions
Angular analysis of the B-0 -> K*(0) e(+) e(-) decay in the low-q(2) region
An angular analysis of the decay is performed using a data sample, corresponding to an integrated luminosity of 3.0 {\mbox{fb}^{-1}}, collected by the LHCb experiment in collisions at centre-of-mass energies of 7 and 8 TeV during 2011 and 2012. For the first time several observables are measured in the dielectron mass squared () interval between 0.002 and 1.120. The angular observables and which are related to the polarisation and to the lepton forward-backward asymmetry, are measured to be and , where the first uncertainty is statistical and the second systematic. The angular observables and which are sensitive to the photon polarisation in this range, are found to be and . The results are consistent with Standard Model predictions.An angular analysis of the B â K^{*}^{0} e e decay is performed using a data sample, corresponding to an integrated luminosity of 3.0 fb, collected by the LHCb experiment in pp collisions at centre-of-mass energies of 7 and 8 TeV during 2011 and 2012. For the first time several observables are measured in the dielectron mass squared (q) interval between 0.002 and 1.120 GeV /c. The angular observables F and A which are related to the K^{*}^{0} polarisation and to the lepton forward-backward asymmetry, are measured to be F = 0.16 ± 0.06 ± 0.03 and A â=â0.10â±â0.18â±â0.05, where the first uncertainty is statistical and the second systematic. The angular observables A and A which are sensitive to the photon polarisation in this q range, are found to be A â=âââ0.23â±â0.23â±â0.05 and A â=â0.14â±â0.22â±â0.05. The results are consistent with Standard Model predictions.An angular analysis of the decay is performed using a data sample, corresponding to an integrated luminosity of 3.0 {\mbox{fb}^{-1}}, collected by the LHCb experiment in collisions at centre-of-mass energies of 7 and 8 TeV during 2011 and 2012. For the first time several observables are measured in the dielectron mass squared () interval between 0.002 and 1.120. The angular observables and which are related to the polarisation and to the lepton forward-backward asymmetry, are measured to be and , where the first uncertainty is statistical and the second systematic. The angular observables and which are sensitive to the photon polarisation in this range, are found to be and . The results are consistent with Standard Model predictions
A study of CP violation in B-+/- -> DK +/- and B-+/- -> D pi(+/-) decays with D -> (KSK +/-)-K-0 pi(-/+) final states
A first study of CP violation in the decay modes and , where labels a or meson and labels a or meson, is performed. The analysis uses the LHCb data set collected in collisions, corresponding to an integrated luminosity of 3 fb. The analysis is sensitive to the CP-violating CKM phase through seven observables: one charge asymmetry in each of the four modes and three ratios of the charge-integrated yields. The results are consistent with measurements of using other decay modes
Study of the rare B-s(0) and B-0 decays into the pi(+) pi(-) mu(+) mu(-) final state
A search for the rare decays and is performed in a data set corresponding to an integrated luminosity of 3.0 fb collected by the LHCb detector in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV. Decay candidates with pion pairs that have invariant mass in the range 0.5-1.3 GeV/ and with muon pairs that do not originate from a resonance are considered. The first observation of the decay and the first evidence of the decay are obtained and the branching fractions are measured to be and , where the third uncertainty is due to the branching fraction of the decay , used as a normalisation.A search for the rare decays Bs0âÏ+ÏâÎŒ+ÎŒâ and B0âÏ+ÏâÎŒ+ÎŒâ is performed in a data set corresponding to an integrated luminosity of 3.0 fbâ1 collected by the LHCb detector in protonâproton collisions at centre-of-mass energies of 7 and 8 TeV . Decay candidates with pion pairs that have invariant mass in the range 0.5â1.3 GeV/c2 and with muon pairs that do not originate from a resonance are considered. The first observation of the decay Bs0âÏ+ÏâÎŒ+ÎŒâ and the first evidence of the decay B0âÏ+ÏâÎŒ+ÎŒâ are obtained and the branching fractions, restricted to the dipion-mass range considered, are measured to be B(Bs0âÏ+ÏâÎŒ+ÎŒâ)=(8.6±1.5 (stat)±0.7 (syst)±0.7(norm))Ă10â8 and B(B0âÏ+ÏâÎŒ+ÎŒâ)=(2.11±0.51(stat)±0.15(syst)±0.16(norm))Ă10â8 , where the third uncertainty is due to the branching fraction of the decay B0âJ/Ï(âÎŒ+ÎŒâ)Kâ(892)0(âK+Ïâ) , used as a normalisation.A search for the rare decays Bs0âÏ+ÏâÎŒ+ÎŒâ and B0âÏ+ÏâÎŒ+ÎŒâ is performed in a data set corresponding to an integrated luminosity of 3.0 fbâ1 collected by the LHCb detector in protonâproton collisions at centre-of-mass energies of 7 and 8 TeV . Decay candidates with pion pairs that have invariant mass in the range 0.5â1.3 GeV/c2 and with muon pairs that do not originate from a resonance are considered. The first observation of the decay Bs0âÏ+ÏâÎŒ+ÎŒâ and the first evidence of the decay B0âÏ+ÏâÎŒ+ÎŒâ are obtained and the branching fractions, restricted to the dipion-mass range considered, are measured to be B(Bs0âÏ+ÏâÎŒ+ÎŒâ)=(8.6±1.5 (stat)±0.7 (syst)±0.7(norm))Ă10â8 and B(B0âÏ+ÏâÎŒ+ÎŒâ)=(2.11±0.51(stat)±0.15(syst)±0.16(norm))Ă10â8 , where the third uncertainty is due to the branching fraction of the decay B0âJ/Ï(âÎŒ+ÎŒâ)Kâ(892)0(âK+Ïâ) , used as a normalisation.A search for the rare decays and is performed in a data set corresponding to an integrated luminosity of 3.0 fb collected by the LHCb detector in proton-proton collisions at centre-of-mass energies of 7 and 8 TeV. Decay candidates with pion pairs that have invariant mass in the range 0.5-1.3 GeV/ and with muon pairs that do not originate from a resonance are considered. The first observation of the decay and the first evidence of the decay are obtained and the branching fractions, restricted to the dipion-mass range considered, are measured to be and , where the third uncertainty is due to the branching fraction of the decay , used as a normalisation
Observation of the B0 â Ï0Ï0 decay from an amplitude analysis of B0 â (Ï+Ïâ)(Ï+Ïâ) decays
Protonâproton collision data recorded in 2011 and 2012 by the LHCb experiment, corresponding to an integrated luminosity of 3.0 fbâ1 , are analysed to search for the charmless B0âÏ0Ï0 decay. More than 600 B0â(Ï+Ïâ)(Ï+Ïâ) signal decays are selected and used to perform an amplitude analysis, under the assumption of no CP violation in the decay, from which the B0âÏ0Ï0 decay is observed for the first time with 7.1 standard deviations significance. The fraction of B0âÏ0Ï0 decays yielding a longitudinally polarised final state is measured to be fL=0.745â0.058+0.048(stat)±0.034(syst) . The B0âÏ0Ï0 branching fraction, using the B0âÏKâ(892)0 decay as reference, is also reported as B(B0âÏ0Ï0)=(0.94±0.17(stat)±0.09(syst)±0.06(BF))Ă10â6
Measurement of the (eta c)(1S) production cross-section in proton-proton collisions via the decay (eta c)(1S) -> p(p)over-bar
The production of the state in proton-proton collisions is probed via its decay to the final state with the LHCb detector, in the rapidity range GeV/c. The cross-section for prompt production of mesons relative to the prompt cross-section is measured, for the first time, to be at a centre-of-mass energy TeV using data corresponding to an integrated luminosity of 0.7 fb, and at TeV using 2.0 fb. The uncertainties quoted are, in order, statistical, systematic, and that on the ratio of branching fractions of the and decays to the final state. In addition, the inclusive branching fraction of -hadron decays into mesons is measured, for the first time, to be , where the third uncertainty includes also the uncertainty on the inclusive branching fraction from -hadron decays. The difference between the and meson masses is determined to be MeV/c.The production of the state in proton-proton collisions is probed via its decay to the final state with the LHCb detector, in the rapidity range . The cross-section for prompt production of mesons relative to the prompt cross-section is measured, for the first time, to be at a centre-of-mass energy using data corresponding to an integrated luminosity of 0.7Â fb , and at using 2.0Â fb . The uncertainties quoted are, in order, statistical, systematic, and that on the ratio of branching fractions of the and decays to the final state. In addition, the inclusive branching fraction of -hadron decays into mesons is measured, for the first time, to be , where the third uncertainty includes also the uncertainty on the inclusive branching fraction from -hadron decays. The difference between the and meson masses is determined to be .The production of the state in proton-proton collisions is probed via its decay to the final state with the LHCb detector, in the rapidity range GeV/c. The cross-section for prompt production of mesons relative to the prompt cross-section is measured, for the first time, to be at a centre-of-mass energy TeV using data corresponding to an integrated luminosity of 0.7 fb, and at TeV using 2.0 fb. The uncertainties quoted are, in order, statistical, systematic, and that on the ratio of branching fractions of the and decays to the final state. In addition, the inclusive branching fraction of -hadron decays into mesons is measured, for the first time, to be , where the third uncertainty includes also the uncertainty on the inclusive branching fraction from -hadron decays. The difference between the and meson masses is determined to be MeV/c
Search for CP violation using T-odd correlations in D-0 -> K+K-pi(+)pi(-) decays
A search for violation using -odd correlations is performed using the four-body decay, selected from semileptonic decays. The data sample corresponds to integrated luminosities of and recorded at the centre-of-mass energies of 7 TeV and 8 TeV, respectively. The -violating asymmetry is measured to be . Searches for violation in different regions of phase space of the four-body decay, and as a function of the decay time, are also presented. No significant deviation from the conservation hypothesis is found
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