698 research outputs found

    IRAKA: The first Colombian soil information system with digital soil mapping products

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    Los avances en ciencia y tecnología combinados con la necesidad de manejar y administrar los recursos naturales han resultó en un aumento gradual en la disponibilidad de datos del suelo. Esto ha permitido caracterizar, describir o proponer proyectos para abordar cuestiones como la degradación del suelo, la productividad agrícola, las amenazas y los servicios de los ecosistemas. A pesar de la disponibilidad de datos del suelo, los usuarios buscan cada vez más información adicional, oportuna y confiable. para dar respuesta a situaciones actuales y futuras, como la seguridad alimentaria y el cambio climático. IRAKA es un suelo sistema de información para el altiplano cundiboyacense colombiano y el primero en brindar información adicional de fuentes oficiales disponibles. Tiene un diseño modular basado en la organización de una base de datos de suelos cuya estructura incorporó 299 perfiles, 1432 muestras y 55 propiedades y la integración, armonización, y estandarización de 8 estudios de suelos realizados en la zona. La información estructurada permitió modelar y validando las propiedades físicas y químicas a través del mapeo digital del suelo y comparando diferentes máquinas técnicas de aprendizaje, incluyendo bosque aleatorio, guardabosques, máquina de vectores de apoyo y modelos de conjunto de estos Técnicas Las interpolaciones de 11 propiedades cuantitativas y 1 propiedad cualitativa resultaron en aceptables coeficientes de bondad de ajuste debido a diferentes factores: variabilidad de la propiedad, representatividad, distribución en el área de estudio y descripción de la propiedad basada en covariables ambientales. Toda la información generada ha sido disponible para un uso generalizado en diferentes servicios web geográficos. Así, IRAKA contribuye a la gestión de la información y el conocimiento a través de técnicas y herramientas que permiten a los usuarios visualizar nuevos información, utilizar la información y llamar la atención sobre nuevos estudios y mejorar las bases de datos en las que la confianza el nivel es insuficiente y no permite la toma de decisiones

    Agroclimatic zoning methodology for agricultural production systems in dry Caribbean region of Colombia

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    The agricultural sector in Colombia and especially, small-scale agriculture subsector in the Colombian Caribbean has been very vulnerable to the negative impacts of climate variability in part due to the poor existence and lack of access to agroclimatic information. The objective was to build a methodology for agroclimatic zoning for crops growing in Colombian dry Caribbean. To achieve this goal, a case study of tomato crop growing in the municipality of Repelon (Atlantico, Colombia) was selected. The methodology was based in the combination of crop-specific soil suitability assessment and the monthly probability of a humidity condition occurrence in the soil for tomato production under water deficit. Probability was constructed through water balances generated from the Palmer drought severity index, calculated for each month of crop production cycle during the 1980 to 2011 series. The resulting maps show defined areas called Productive Niches with lower limitations per soil and low probabilities of soil water deficit in the growth of tomato crop in the municipality. The methodology can be used to delineate areas suitable for planting tomato or other crops in climate variability events in the dry Caribbean region of Colombi

    Agroclimatic zoning methodology for agricultural production systems in dry Caribbean region of Colombia

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    The agricultural sector in Colombia and especially, small-scale agriculture subsector in the Colombian Caribbean has been very vulnerable to the negative impacts of climate variability in part due to the poor existence and lack of access to agroclimatic information. The objective was to build a methodology for agroclimatic zoning for crops growing in Colombian dry Caribbean. To achieve this goal, a case study of tomato crop growing in the municipality of Repelon (Atlantico, Colombia) was selected. The methodology was based in the combination of crop-specific soil suitability assessment and the monthly probability of a humidity condition occurrence in the soil for tomato production under water deficit. Probability was constructed through water balances generated from the Palmer drought severity index, calculated for each month of crop production cycle during the 1980 to 2011 series. The resulting maps show defined areas called Productive Niches with lower limitations per soil and low probabilities of soil water deficit in the growth of tomato crop in the municipality. The methodology can be used to delineate areas suitable for planting tomato or other crops in climate variability events in the dry Caribbean region of Colombi

    Search for pair production of vector-like quarks in leptonic final states in proton-proton collisions at s \sqrt{s} = 13 TeV

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    A search is presented for vector-like T and B quark-antiquark pairs produced in proton-proton collisions at a center-of-mass energy of 13 TeV. Data were collected by the CMS experiment at the CERN LHC in 2016–2018, with an integrated luminosity of 138 fb1^{−1}. Events are separated into single-lepton, same-sign charge dilepton, and multi-lepton channels. In the analysis of the single-lepton channel a multilayer neural network and jet identification techniques are employed to select signal events, while the same-sign dilepton and multilepton channels rely on the high-energy signature of the signal to distinguish it from standard model backgrounds. The data are consistent with standard model background predictions, and the production of vector-like quark pairs is excluded at 95% confidence level for T quark masses up to 1.54 TeV and B quark masses up to 1.56 TeV, depending on the branching fractions assumed, with maximal sensitivity to decay modes that include multiple top quarks. The limits obtained in this search are the strongest limits to date for TT \textrm{T}\overline{\textrm{T}} production, excluding masses below 1.48 TeV for all decays to third generation quarks, and are the strongest limits to date for BB \textrm{B}\overline{\textrm{B}} production with B quark decays to tW.[graphic not available: see fulltext

    Search for top squarks in the four-body decay mode with single lepton final states in proton-proton collisions at s= \sqrt{s}= 13 TeV

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    A search for the pair production of the lightest supersymmetric partner of the top quark, the top squark (t~1 \tilde{\mathrm{t}}_{1} ), is presented. The search targets the four-body decay of the t~1 \tilde{\mathrm{t}}_{1} , which is preferred when the mass difference between the top squark and the lightest supersymmetric particle is smaller than the mass of the W boson. This decay mode consists of a bottom quark, two other fermions, and the lightest neutralino (χ~10 \tilde{\chi}_{1}^{0} ), which is assumed to be the lightest supersymmetric particle. The data correspond to an integrated luminosity of 138 fb1 ^{-1} of proton-proton collisions at a center-of-mass energy of 13 TeV collected by the CMS experiment at the CERN LHC. Events are selected using the presence of a high-momentum jet, an electron or muon with low transverse momentum, and a significant missing transverse momentum. The signal is selected based on a multivariate approach that is optimized for the difference between m(t~1) m(\tilde{\mathrm{t}}_{1}) and m(χ~10) m(\tilde{\chi}_{1}^{0}) . The contribution from leading background processes is estimated from data. No significant excess is observed above the expectation from standard model processes. The results of this search exclude top squarks at 95% confidence level for masses up to 480 and 700 GeV for m(t~1)m(χ~10)= m(\tilde{\mathrm{t}}_{1}) - m(\tilde{\chi}_{1}^{0}) = 10 and 80 GeV, respectively.A search for the pair production of the lightest supersymmetric partner of the top quark, the top squark (t1 {\overset{\sim }{\textrm{t}}}_1 ), is presented. The search targets the four-body decay of the t1 {\overset{\sim }{\textrm{t}}}_1 , which is preferred when the mass difference between the top squark and the lightest supersymmetric particle is smaller than the mass of the W boson. This decay mode consists of a bottom quark, two other fermions, and the lightest neutralino (χ10 {\overset{\sim }{\chi}}_1^0 ), which is assumed to be the lightest supersymmetric particle. The data correspond to an integrated luminosity of 138 fb1^{−1} of proton-proton collisions at a center-of-mass energy of 13 TeV collected by the CMS experiment at the CERN LHC. Events are selected using the presence of a high-momentum jet, an electron or muon with low transverse momentum, and a significant missing transverse momentum. The signal is selected based on a multivariate approach that is optimized for the difference between m(t1 {\overset{\sim }{\textrm{t}}}_1 ) and m(χ10 {\overset{\sim }{\chi}}_1^0 ). The contribution from leading background processes is estimated from data. No significant excess is observed above the expectation from standard model processes. The results of this search exclude top squarks at 95% confidence level for masses up to 480 and 700 GeV for m(t1 {\overset{\sim }{\textrm{t}}}_1 ) − m(χ10 {\overset{\sim }{\chi}}_1^0 ) = 10 and 80 GeV, respectively.[graphic not available: see fulltext]A search for the pair production of the lightest supersymmetric partner of the top quark, the top squark (t~1\tilde{\mathrm{t}}_1), is presented. The search targets the four-body decay of the t~1\tilde{\mathrm{t}}_1, which is preferred when the mass difference between the top squark and the lightest supersymmetric particle is smaller than the mass of the W boson. This decay mode consists of a bottom quark, two other fermions, and the lightest neutralino (χ~10\tilde{\chi}^0_1), which is assumed to be the lightest supersymmetric particle. The data correspond to an integrated luminosity of 138 fb1^{-1} of proton-proton collisions at a center-of-mass energy of 13 TeV collected by the CMS experiment at the CERN LHC. Events are selected using the presence of a high-momentum jet, an electron or muon with low transverse momentum, and a significant missing transverse momentum. The signal is selected based on a multivariate approach that is optimized for the difference between m(t~1)m(\tilde{\mathrm{t}}_1) and m(χ~10)m(\tilde{\chi}^0_1). The contribution from leading background processes is estimated from data. No significant excess is observed above the expectation from standard model processes. The results of this search exclude top squarks at 95% confidence level for masses up to 480 and 700 GeV for m(t~1)m(χ~10m(\tilde{\mathrm{t}}_1) - m(\tilde{\chi}^0_1) = 10 and 80 GeV, respectively

    Search for Higgs Boson and Observation of Z Boson through their Decay into a Charm Quark-Antiquark Pair in Boosted Topologies in Proton-Proton Collisions at s\sqrt{s} =13 TeV

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    A search for the standard model (SM) Higgs boson (H) produced with transverse momentum greater than 450 GeV and decaying to a charm quark-antiquark (ccˉ\mathrm{c\bar{c}}) pair is presented. The search is performed using proton-proton collision data collected at s\sqrt{s} = 13 TeV by the CMS experiment at the LHC, corresponding to an integrated luminosity of 138 fb1^{-1}. Boosted H \toccˉ\mathrm{c\bar{c}} decay products are reconstructed as a single large-radius jet and identified using a deep neural network charm tagging technique. The method is validated by measuring the Z \toccˉ\mathrm{c\bar{c}} decay process, which is observed in association with jets at high pTp_\mathrm{T} for the first time with a signal strength of 1.00 0.14+0.17_{-0.14}^{+0.17} (syst) ±\pm 0.08 (theo) ±\pm 0.06 (stat), defined as the ratio of the observed process rate to the standard model expectation. The observed (expected) upper limit on σ\sigma(H) B\mathcal{B}(H \toccˉ\mathrm{c\bar{c}}) is set at 47 (39) times the SM prediction at 95% confidence level
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