354 research outputs found

    Diagnóstico sobre el cultivo de la soya en el departamento del Meta.

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    Se indica que las contadas explotaciones se han localizado en las vegas de los ríos Negro y Guayuriba y en las terrazas medias del Municipio Acacías, en siembras de segundo semestre como resultado de los programas de fomento llevados a cabo por iniciativa de Almaviva. S presenta la magnitud y composición de la producción en términos de magnitud física y económica. Bajo la primera se considera el rendimiento físico/ha y la producción total obtenida en la serie histórica que va de 1970 a 1972. Los ensayos bajo el convenio Almaviva-ICA, se referían únicamente a fertilización preliminar en suelos de vega y terraza media, no se conocían otras prácticas de cultivo como control de plagas, enfermedades y malezas, ni había experiencia de maquinaria agrícola. Luego se presentan costos de producción/ha para el Meta 1971-B y 1973-B. Se presentan las propiedades físicas y químicas de suelos de vega y terrazas aluviales. Se recomienda sembrar entre Septiembre 20 y Octubre 20, para iniciar recolección a principios de Enero. Durante el cultivo se relacionan las siguientes plagas : tierreros, comedores de hojas, cucarroncito del foallej, barrenadores del tallo, heliothis sp. Se recomienda proveer de máquinas apropiadas para siembra y cosecha, realizar cursos para asistentes técnicos. Solicitar ajuste de financiación, ofrecer seguridad en precios de mercado, establecer pruebas semicomerciales demostrativas en áreas de producción, establecer investigaciones de leguminosas de grano y oleaginosas anuales en el Llano, y reglamentación de crédito para adecuación de tierrasSoya-Soja- Glycine ma

    “Male effect” and “temporary weaning” in synchronization of post-partum ovarian activity in Pelibuey ewes

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    To evaluate the response of the “male effect” and “temporary weaning” on the synchronization of post-partum ovarian activity in Pelibuey ewes, an experiment was carried out using 78 Pelibuey ewes with suckling lambs. The ewes were separated from their offspring for 48 hours and randomly assigned to one of four treatments derived from the arrangement of two factors, “male effect” and “temporary weaning”, each at two levels. Treatments were: T1 (n = 20) control ewes, without “male effect” and without “temporary weaning”); T2 (n = 19) ewes without “male effect” and with “temporary weaning”; T3 (n = 20) ewes with “male effect” and without “temporary weaning”; and T4 (n = 19), ewes with “male effect” and with “temporary weaning”. The response to oestrus, return to oestrus, gestation rate and lambing rate were analysed using logistic regression. The onset of oestrus was analysed using survival curves. No significant differences were found for lambing rate and prolificacy among treatments. “Temporary weaning” (T2) and “male effect” (T3) did not influence the response to oestrus, rate and duration of return to oestrus, or gestation rate and fertility, and was similar to the control group (T1). The interaction of “male effect” with “temporary weaning” (T4) increased the response to oestrus, reduced the rate and duration of return to oestrus, and the gestation rate, but increased fertility. Synchronizing post-partum ovarian activity with “male effect” and “temporary weaning” reduces the onset of oestrus and the rate of return to oestrus, but increases the response to oestrus and fecundity in Pelibuey ewes.Keywords: Biostimulation, progestogens, prolificacy, prostaglandins, sucklin

    Anisotropic flow of charged hadrons, pions and (anti-)protons measured at high transverse momentum in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}}=2.76 TeV

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    The elliptic, v2v_2, triangular, v3v_3, and quadrangular, v4v_4, azimuthal anisotropic flow coefficients are measured for unidentified charged particles, pions and (anti-)protons in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm NN}} = 2.76 TeV with the ALICE detector at the Large Hadron Collider. Results obtained with the event plane and four-particle cumulant methods are reported for the pseudo-rapidity range η<0.8|\eta|<0.8 at different collision centralities and as a function of transverse momentum, pTp_{\rm T}, out to pT=20p_{\rm T}=20 GeV/cc. The observed non-zero elliptic and triangular flow depends only weakly on transverse momentum for pT>8p_{\rm T}>8 GeV/cc. The small pTp_{\rm T} dependence of the difference between elliptic flow results obtained from the event plane and four-particle cumulant methods suggests a common origin of flow fluctuations up to pT=8p_{\rm T}=8 GeV/cc. The magnitude of the (anti-)proton elliptic and triangular flow is larger than that of pions out to at least pT=8p_{\rm T}=8 GeV/cc indicating that the particle type dependence persists out to high pTp_{\rm T}.Comment: 16 pages, 5 captioned figures, authors from page 11, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/186

    Centrality dependence of charged particle production at large transverse momentum in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm{NN}}} = 2.76 TeV

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    The inclusive transverse momentum (pTp_{\rm T}) distributions of primary charged particles are measured in the pseudo-rapidity range η<0.8|\eta|<0.8 as a function of event centrality in Pb-Pb collisions at sNN=2.76\sqrt{s_{\rm{NN}}}=2.76 TeV with ALICE at the LHC. The data are presented in the pTp_{\rm T} range 0.15<pT<500.15<p_{\rm T}<50 GeV/cc for nine centrality intervals from 70-80% to 0-5%. The Pb-Pb spectra are presented in terms of the nuclear modification factor RAAR_{\rm{AA}} using a pp reference spectrum measured at the same collision energy. We observe that the suppression of high-pTp_{\rm T} particles strongly depends on event centrality. In central collisions (0-5%) the yield is most suppressed with RAA0.13R_{\rm{AA}}\approx0.13 at pT=6p_{\rm T}=6-7 GeV/cc. Above pT=7p_{\rm T}=7 GeV/cc, there is a significant rise in the nuclear modification factor, which reaches RAA0.4R_{\rm{AA}} \approx0.4 for pT>30p_{\rm T}>30 GeV/cc. In peripheral collisions (70-80%), the suppression is weaker with RAA0.7R_{\rm{AA}} \approx 0.7 almost independently of pTp_{\rm T}. The measured nuclear modification factors are compared to other measurements and model calculations.Comment: 17 pages, 4 captioned figures, 2 tables, authors from page 12, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/284

    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

    Measurement of charm production at central rapidity in proton-proton collisions at s=2.76\sqrt{s} = 2.76 TeV

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    The pTp_{\rm T}-differential production cross sections of the prompt (B feed-down subtracted) charmed mesons D0^0, D+^+, and D+^{*+} in the rapidity range y<0.5|y|<0.5, and for transverse momentum 1<pT<121< p_{\rm T} <12 GeV/cc, were measured in proton-proton collisions at s=2.76\sqrt{s} = 2.76 TeV with the ALICE detector at the Large Hadron Collider. The analysis exploited the hadronic decays D0^0 \rightarrow Kπ\pi, D+^+ \rightarrow Kππ\pi\pi, D+^{*+} \rightarrow D0π^0\pi, and their charge conjugates, and was performed on a Lint=1.1L_{\rm int} = 1.1 nb1^{-1} event sample collected in 2011 with a minimum-bias trigger. The total charm production cross section at s=2.76\sqrt{s} = 2.76 TeV and at 7 TeV was evaluated by extrapolating to the full phase space the pTp_{\rm T}-differential production cross sections at s=2.76\sqrt{s} = 2.76 TeV and our previous measurements at s=7\sqrt{s} = 7 TeV. The results were compared to existing measurements and to perturbative-QCD calculations. The fraction of cdbar D mesons produced in a vector state was also determined.Comment: 20 pages, 5 captioned figures, 4 tables, authors from page 15, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/307

    Diagnóstico de la comunicación rural en Colombia.

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    El objetivo es conocer el estado actual de la investigación realizada en el país sobre comunicación rural y las necesidades de investigación para transferencia de tecnología agropecuaria según los agentes de cambio del ICA. El trabajo se inició con la conformación de un grupo multidisciplinario integrado por funcionarios del ICA, profesionales en agronomía, medicina veterinaria, comunicación social y economía del hogar. Se recolectaron 171 investigaciones sobre comunicación rural de las cuales se eliminaron 43 debido a que no encajaban dentro de los criterios establecidos para el análisis, haciéndose sobre 128 trabajos. Con base en los resultados y discusión se presentan las siguientes conclusiones : Es poca la investigación sobre el análisis de la fuente o emisor en cuanto a sus actividades y capacidad para actuar como tal. En cuanto al mensaje no se observa una clara tendencia hacia el estudio del mismo. Existe muy poca investigación sobre formas y medios de comunicación individuales y de grupos, en contraste con los estudios sobre medios masivos. La mayoría de las investigaciones sobre medios han sido realizadas por ACPO. La investigación en comunicación se ha ocupado preferencialmente del pequeño agricultor, usuario atendido con asistencia técnica oficial. Los trabajos se han encaminado a determinar la adopción de prácticas, el planeamiento de la comunicación, el análisis interno e impacto de la comunicación. En la región Andina se concentra la mayor parte de los estudios. El ICA es la institución que ha realizado mayor número de investigaciones en comunicación rural principalmente, en las áreas cubiertas por sus Distritos de Transferencia de Tecnología, le siguen en su orden las universidades, el Programa de Estudios para Graduados UN-ICA y ACP

    Inclusive J/psi production in pp collisions at sqrt(s) = 2.76 TeV

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    The ALICE Collaboration has measured inclusive J/psi production in pp collisions at a center of mass energy sqrt(s)=2.76 TeV at the LHC. The results presented in this Letter refer to the rapidity ranges |y|<0.9 and 2.5<y<4 and have been obtained by measuring the electron and muon pair decay channels, respectively. The integrated luminosities for the two channels are L^e_int=1.1 nb^-1 and L^mu_int=19.9 nb^-1, and the corresponding signal statistics are N_J/psi^e+e-=59 +/- 14 and N_J/psi^mu+mu-=1364 +/- 53. We present dsigma_J/psi/dy for the two rapidity regions under study and, for the forward-y range, d^2sigma_J/psi/dydp_t in the transverse momentum domain 0<p_t<8 GeV/c. The results are compared with previously published results at sqrt(s)=7 TeV and with theoretical calculations.Comment: 7 figures, 3 tables, accepted for publication in Phys. Lett.

    Ks0^0_sKs0^0_s correlations in pp collisions at s=7\sqrt{s}=7 TeV from the LHC ALICE experiment

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    Identical neutral kaon pair correlations are measured in s=7\sqrt{s}=7 TeV pp collisions in the ALICE experiment. One-dimensional Ks0^0_sKs0^0_s correlation functions in terms of the invariant momentum difference of kaon pairs are formed in two multiplicity and two transverse momentum ranges. The femtoscopic parameters for the radius and correlation strength of the kaon source are extracted. The fi{\rm i}t includes quantum statistics and final-state interactions of the a0_0/f0_0 resonance. Ks0^0_sKs0^0_s correlations show an increase in radius for increasing multiplicity and a slight decrease in radius for increasing transverse mass, mTm_{\rm T}, as seen in ππ\pi\pi correlations in the pp system and in heavy-ion collisions. Transverse mass scaling is observed between the Ks0^0_sKs0^0_s and ππ\pi\pi radii. Also, the fi{\rm i}rst observation is made of the decay of the f2_2'(1525) meson into the Ks0^0_sKs0^0_s channel in pp collisions.Comment: 17 pages, 7 captioned figures, 2 tables, authors from page 12, published version, figures at http://aliceinfo.cern.ch/ArtSubmission/node/310
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