125 research outputs found

    Public Policies for the Development of Agroecosystems Resilient to Climate Change

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    Objective: Analyze public policies in Mexico facing climate change in agriculture that allow the development of resilient agroecosystems. Design/methodology/approach: An analysis of research on resilience to climate change in the agricultural and rural sectors, as well as analysis of literature on public policies formulated to climate change in the agricultural sector (period 2013-2019), was realized. Results: Multiple sources of resilience for agroecosystems are present. Policies could be oriented to identify such sources and to strengthen capacities according to different scales and contexts. There is the possibility of considering factors associated with the evolution of these systems to employ strategies that are consistent and that allow coordination between political levels. Limitations of the study/Implications: This is a theoretical study restricted to the available literature published until 2019. Findings/Conclusions: Public policies require integrating the perspective of the dynamics of the complex agricultural system and the multiple sources of resilience at different scales and contexts, articulating the development of resilient agroecosystems to climate change.Objective: Analyze public policies in Mexico facing climate change in agriculture that allow the development of resilient agroecosystems. Design/methodology/approach: An analysis of research on resilience to climate change in the agricultural and rural sectors, as well as analysis of literature on public policies formulated to climate change in the agricultural sector (period 2013-2019), was realized. Results: Multiple sources of resilience for agroecosystems are present. Policies could be oriented to identify such sources and to strengthen capacities according to different scales and contexts. There is the possibility of considering factors associated with the evolution of these systems to employ strategies that are consistent and that allow coordination between political levels. Limitations of the study/Implications: This is a theoretical study restricted to the available literature published until 2019. Findings/Conclusions: Public policies require integrating the perspective of the dynamics of the complex agricultural system and the multiple sources of resilience at different scales and contexts, articulating the development of resilient agroecosystems to climate change

    Large enhancement of deuteron polarization with frequency modulated microwaves

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    We report a large enhancement of 1.7 in deuteron polarization up to values of 0.6 due to frequency modulation of the polarizing microwaves in a two liters polarized target using the method of dynamic nuclear polarization. This target was used during a deep inelastic polarized muon-deuteron scattering experiment at CERN. Measurements of the electron paramagnetic resonance absorption spectra show that frequency modulation gives rise to additional microwave absorption in the spectral wings. Although these results are not understood theoretically, they may provide a useful testing ground for the deeper understanding of dynamic nuclear polarization.Comment: 10 pages, including the figures coming in uuencoded compressed tar files in poltar.uu, which also brings cernart.sty and crna12.sty files neede

    Anisotropy studies around the galactic centre at EeV energies with the Auger Observatory

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    Data from the Pierre Auger Observatory are analyzed to search for anisotropies near the direction of the Galactic Centre at EeV energies. The exposure of the surface array in this part of the sky is already significantly larger than that of the fore-runner experiments. Our results do not support previous findings of localized excesses in the AGASA and SUGAR data. We set an upper bound on a point-like flux of cosmic rays arriving from the Galactic Centre which excludes several scenarios predicting sources of EeV neutrons from Sagittarius AA. Also the events detected simultaneously by the surface and fluorescence detectors (the `hybrid' data set), which have better pointing accuracy but are less numerous than those of the surface array alone, do not show any significant localized excess from this direction.Comment: Matches published versio

    Consenso colombiano de atención, diagnóstico y manejo de la infección por SARS-COV-2/COVID-19 en establecimientos de atención de la salud Recomendaciones basadas en consenso de expertos e informadas en la evidencia

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    The “Asociación Colombiana de Infectología” (ACIN) and the “Instituto de Evaluación de Nuevas Tecnologías de la Salud” (IETS) created a task force to develop recommendations for Covid 19 health care diagnosis, management and treatment informed, and based, on evidence. Theses reccomendations are addressed to the health personnel on the Colombian context of health services. © 2020 Asociacion Colombiana de Infectologia. All rights reserved

    Limit on Bs0B^0_s oscillation using a jet charge method

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    A lower limit is set on the B_{s}^{0} meson oscillation parameter \Delta m_{s} using data collected from 1991 to 1994 by the ALEPH detector. Events with a high transverse momentum lepton and a reconstructed secondary vertex are used. The high transverse momentum leptons are produced mainly by b hadron decays, and the sign of the lepton indicates the particle/antiparticle final state in decays of neutral B mesons. The initial state is determined by a jet charge technique using both sides of the event. A maximum likelihood method is used to set a lower limit of \, \Delta m_{s}. The 95\% confidence level lower limit on \Delta m_s ranges between 5.2 and 6.5(\hbar/c^{2})~ps^{-1} when the fraction of b quarks from Z^0 decays that form B_{s}^{0} mesons is varied from 8\% to 16\%. Assuming that the B_{s}^{0} fraction is 12\%, the lower limit would be \Delta m_{s} 6.1(\hbar/c^{2})~ps^{-1} at 95\% confidence level. For x_s = \Delta m_s \, \tau_{B_s}, this limit also gives x_s 8.8 using the B_{s}^{0} lifetime of \tau_{B_s} = 1.55 \pm 0.11~ps and shifting the central value of \tau_{B_s} down by 1\sigma

    Measurement of the Bs0^0_s lifetime and production rate with Dsl+^-_s l^+ combinations in Z decays

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    The lifetime of the \bs meson is measured in approximately 3 million hadronic Z decays accumulated using the ALEPH detector at LEP from 1991 to 1994. Seven different \ds decay modes were reconstructed and combined with an opposite sign lepton as evidence of semileptonic \bs decays. Two hundred and eight \dsl candidates satisfy selection criteria designed to ensure precise proper time reconstruction and yield a measured \bs lifetime of \mbox{\result .} Using a larger, less constrained sample of events, the product branching ratio is measured to be \mbox{\pbrresult

    Measurement of the tau lepton lifetime

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    Measurement of Lambda polarization from Z decays

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    Measurement of the tau lepton lifetime

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    The forward-backward asymmetry for charm quarks at the Z pole

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