1,050 research outputs found

    New Genotypes of Long and Thin Grain Rice and Technology for Production in Mexico: Michoacán State as an Example

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    In Mexico, the national demand for rice exceeds four times the consumption of the grain produced internally, which has caused growing volumes of imported rice. Long and thin-type rice is the one with the highest consumption. Faced with this problem, a strategy was implemented based on the evaluation, validation, and release of rice materials. Since Michoacán State is involved in rice production, evaluations have allowed the selection of materials, which has resulted in the current availability of a number of advanced experimental lines. Also, the technology that has traditionally been used in the cultivation had changed, so that continuous improvement programs have been developed represented by the system of cultivation in direct sowing in furrows and continuous irrigation. The new varieties do not require continuous flooding, which allows for a greater efficiency in the use of water and soil resources. Studies on rice nutrition in Mexico are still scarce, especially under irrigated conditions. The current has focused on the nitrogen fertilization of this crop since the exploration of the efficient management of soil nutrition is a vitally important issue. Other aspects integrated to the rice technology are the use of a low seed rate and weed management using a new generation of herbicides

    Energy Estimation of Cosmic Rays with the Engineering Radio Array of the Pierre Auger Observatory

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    The Auger Engineering Radio Array (AERA) is part of the Pierre Auger Observatory and is used to detect the radio emission of cosmic-ray air showers. These observations are compared to the data of the surface detector stations of the Observatory, which provide well-calibrated information on the cosmic-ray energies and arrival directions. The response of the radio stations in the 30 to 80 MHz regime has been thoroughly calibrated to enable the reconstruction of the incoming electric field. For the latter, the energy deposit per area is determined from the radio pulses at each observer position and is interpolated using a two-dimensional function that takes into account signal asymmetries due to interference between the geomagnetic and charge-excess emission components. The spatial integral over the signal distribution gives a direct measurement of the energy transferred from the primary cosmic ray into radio emission in the AERA frequency range. We measure 15.8 MeV of radiation energy for a 1 EeV air shower arriving perpendicularly to the geomagnetic field. This radiation energy -- corrected for geometrical effects -- is used as a cosmic-ray energy estimator. Performing an absolute energy calibration against the surface-detector information, we observe that this radio-energy estimator scales quadratically with the cosmic-ray energy as expected for coherent emission. We find an energy resolution of the radio reconstruction of 22% for the data set and 17% for a high-quality subset containing only events with at least five radio stations with signal.Comment: Replaced with published version. Added journal reference and DO

    Measurement of the Radiation Energy in the Radio Signal of Extensive Air Showers as a Universal Estimator of Cosmic-Ray Energy

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    We measure the energy emitted by extensive air showers in the form of radio emission in the frequency range from 30 to 80 MHz. Exploiting the accurate energy scale of the Pierre Auger Observatory, we obtain a radiation energy of 15.8 \pm 0.7 (stat) \pm 6.7 (sys) MeV for cosmic rays with an energy of 1 EeV arriving perpendicularly to a geomagnetic field of 0.24 G, scaling quadratically with the cosmic-ray energy. A comparison with predictions from state-of-the-art first-principle calculations shows agreement with our measurement. The radiation energy provides direct access to the calorimetric energy in the electromagnetic cascade of extensive air showers. Comparison with our result thus allows the direct calibration of any cosmic-ray radio detector against the well-established energy scale of the Pierre Auger Observatory.Comment: Replaced with published version. Added journal reference and DOI. Supplemental material in the ancillary file

    Measurement of the cosmic ray spectrum above 4×10184{\times}10^{18} eV using inclined events detected with the Pierre Auger Observatory

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    A measurement of the cosmic-ray spectrum for energies exceeding 4×10184{\times}10^{18} eV is presented, which is based on the analysis of showers with zenith angles greater than 6060^{\circ} detected with the Pierre Auger Observatory between 1 January 2004 and 31 December 2013. The measured spectrum confirms a flux suppression at the highest energies. Above 5.3×10185.3{\times}10^{18} eV, the "ankle", the flux can be described by a power law EγE^{-\gamma} with index γ=2.70±0.02(stat)±0.1(sys)\gamma=2.70 \pm 0.02 \,\text{(stat)} \pm 0.1\,\text{(sys)} followed by a smooth suppression region. For the energy (EsE_\text{s}) at which the spectral flux has fallen to one-half of its extrapolated value in the absence of suppression, we find Es=(5.12±0.25(stat)1.2+1.0(sys))×1019E_\text{s}=(5.12\pm0.25\,\text{(stat)}^{+1.0}_{-1.2}\,\text{(sys)}){\times}10^{19} eV.Comment: Replaced with published version. Added journal reference and DO

    MAREJADAS RURALES Y LUCHAS POR LA VIDA, VOL. II: CONFLICTOS SOCIOTERRITORIALES Y POR RECURSOS NATURALES

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    Volumen 2. Conflictos socioterritoriales y por recursos naturales, coordinado por: Rosalía López Paniagua, Dante Ariel Ayala Ortiz y Armando Contreras Hernández, constituido por 19 trabajos, divididos en tres secciones. La primera titulada Tierra: tenencia y cultivos transgénicos, contiene 6 trabajos, que abordan el persistente conflicto por la tenencia de la tierra y la producción de soya y maíz transgénico y la asociada acumulación del capital por despojo que caracteriza la agricultura transgénica en México, pero también formas de resistencia como la denuncia de contaminación transgénica en la Sierra Juárez de Oaxaca y las instituciones, actores y gestión en la Reserva de la Biósfera El Triunfo en la Sierra Madre de Chiapas. La segunda sección: Territorio: Explotación y envenenamiento, está compuesta por 5 trabajos que hacen referencia a los conflictos socioambientales derivados de la minería en manos de empresas nacionales y extranjeras omisas y gobiernos cómplices de las consecuencias depredadoras que generan en territorios campesinos e indígenas, debido a su asociación con el narcotráfico y por la contaminación del agua y la tierra que provocan, además de las consecuencias perversas en la salud humana y el entorno natural en diversas regiones del país. En la tercera y última sección, Agua: contaminación y escases, los 8 trabajos que la integran, analizan los conflictos socioterritoriales y luchas por la vida, en diversos estados del país. Se trata de investigaciones que estudian movimientos y conflictos sociales actuales en el campo mexicano, como son las luchas por la defensa del territorio y la defensa de la naturaleza, trabajos que abordan especialmente las disputas por el agua, y los problemas asociados del acceso, la escasez y la contaminación, no solo internos sino con empresas y con el Estado mismo que con la aprobación y aplicación de leyes y reglamentos, el despojo a los campesinos de su territorio en el que han trabajado y vivido por generaciones.INSTITUTO DE CIENCIAS AGROPECUARIAS Y RURALES (ICAR), UNIVERSIDAD DE GUADALAJARA, EL COLEGIO DE MICHOACÁN A.C., FACULTAD DE ESTUDIOS SUPERIORES ACATLÁN-UNAM, ECOSUR, CUCOSTA SUR GRANA, ASOCIACIÓN MEXICANA DE ESTUDIOS RURALES A.C

    Métodos y técnicas de monitoreo y predicción temprana en los escenarios de riesgos socionaturales

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    Esta obra concentra los métodos y las técnicas fundamentales para el seguimiento y monitoreo de las dinámicas de los escenarios de riesgos socionaturales (geológicos e hidrometeorológicos) y tiene como objetivo general orientar, apoyar y acompañar a los directivos y operativos de protección civil en aterrizar las acciones y políticas públicas enfocadas a la gestión del riesgo local de desastre

    Long-range angular correlations on the near and away side in p–Pb collisions at

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    Optimasi Portofolio Resiko Menggunakan Model Markowitz MVO Dikaitkan dengan Keterbatasan Manusia dalam Memprediksi Masa Depan dalam Perspektif Al-Qur`an

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    Risk portfolio on modern finance has become increasingly technical, requiring the use of sophisticated mathematical tools in both research and practice. Since companies cannot insure themselves completely against risk, as human incompetence in predicting the future precisely that written in Al-Quran surah Luqman verse 34, they have to manage it to yield an optimal portfolio. The objective here is to minimize the variance among all portfolios, or alternatively, to maximize expected return among all portfolios that has at least a certain expected return. Furthermore, this study focuses on optimizing risk portfolio so called Markowitz MVO (Mean-Variance Optimization). Some theoretical frameworks for analysis are arithmetic mean, geometric mean, variance, covariance, linear programming, and quadratic programming. Moreover, finding a minimum variance portfolio produces a convex quadratic programming, that is minimizing the objective function ðð¥with constraintsð ð 𥠥 ðandð´ð¥ = ð. The outcome of this research is the solution of optimal risk portofolio in some investments that could be finished smoothly using MATLAB R2007b software together with its graphic analysis
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