Impacts of Colombia's current irrigation management transfer program

Privatization / Irrigation management / Irrigated farming / Policy / Costs / Economic aspects / Operations / Maintenance / Agricultural production

Assessing irrigation performance with comparative indicators: The case of the Alto Rio Lerma Irrigation District, Mexico

Irrigation management / Irrigation scheduling / Water allocation / Water distribution / Case studies / Institutional constraints / Operation / Monitoring / Indicators / Performance indexes / Water rights / Economic aspects / Data collection / Environmental effects / Performance evaluation / Water use efficiency

Magnetostratigraphy of the Miocene continental deposits of the Montes de Castejón (central Ebro basin, Spain): geochronological and paleoenvironmental implications

A detailed magnetostratigraphic study has been carried out in the early to middle Miocene distal alluvial and lacustrine sediments of the Montes de Castejón (central Ebro Basin). The study was based on the analysis of 196 magnetostratigraphic sites sampled along a stratigraphic interval of about 240 meters. Local magnetostratigraphy yielded a sequence of 12 magnetozones (6 normal and 6 reverse) which could be correlated with the Geomagnetic Polarity Time Scale (GPTS) interval C5Cr to C5AD (between 17 and 14.3 Ma.). The sampled sedimentary sequences include the boundary between two tectosedimentary units (TSU, T5 and T6) already defined in the Ebro Basin. The magnetostratigraphy of the Montes de Castejón allows to date the T5/T6 TSU boundary at 16.14 Ma, within chron C5Cn.1n. This magnetostratigraphy also allows us to analyse in detail as well as to discuss the variations in sedimentation rates through space and time between different lacustrine environments: Outer carbonate lacustrine fringes and distal alluvial plains (Montes de Castejón sections) show higher sedimentation rates than offshore lacustrine areas (San Caprasio section, 50 km east of Montes de Castejón)

The reactor antineutrino anomaly and low energy threshold neutrino experiments

Short distance reactor antineutrino experiments measure an antineutrino spectrum a few percent lower than expected from theoretical predictions. In this work we study the potential of low energy threshold reactor experiments in the context of a light sterile neutrino signal. We discuss the perspectives of the recently detected coherent elastic neutrino-nucleus scattering in future reactor antineutrino experiments. We find that the expectations to improve the current constraints on the mixing with sterile neutrinos are promising. We also analyse the measurements of antineutrino scattering off electrons from short distance reactor experiments. In this case, the statistics is not competitive with inverse beta decay experiments, although future experiments might play a role when compare it with the Gallium anomaly.Comment: 9 pages, 6 figures, 1 table, matches published versio

Floquet theory for temporal correlations and spectra in time-periodic open quantum systems: Application to squeezed parametric oscillation beyond the rotating-wave approximation

Open quantum systems can display periodic dynamics at the classical level either due to external periodic modulations or to self-pulsing phenomena typically following a Hopf bifurcation. In both cases, the quantum fluctuations around classical solutions do not reach a quantum-statistical stationary state, which prevents adopting the simple and reliable methods used for stationary quantum systems. Here we put forward a general and efficient method to compute two-time correlations and corresponding spectral densities of time-periodic open quantum systems within the usual linearized (Gaussian) approximation for their dynamics. Using Floquet theory we show how the quantum Langevin equations for the fluctuations can be efficiently integrated by partitioning the time domain into one-period duration intervals, and relating the properties of each period to the first one. Spectral densities, like squeezing spectra, are computed similarly, now in a two-dimensional temporal domain that is treated as a chessboard with one-period x one-period cells. This technique avoids cumulative numerical errors as well as efficiently saves computational time. As an illustration of the method, we analyze the quantum fluctuations of a damped parametrically-driven oscillator (degenerate parametric oscillator) below threshold and far away from rotating-wave approximation conditions, which is a relevant scenario for modern low-frequency quantum oscillators. Our method reveals that the squeezing properties of such devices are quite robust against the amplitude of the modulation or the low quality of the oscillator, although optimal squeezing can appear for parameters that are far from the ones predicted within the rotating-wave approximation.Comment: Comments and constructive criticism are welcom

Performance of two transferred modules in the Lagunera Region: Water relations

Water policy / Performance / Privatization / Irrigation systems / Operations / Maintenance / Irrigation efficiency / Water users' associations / Water rights / Water allocation / Water supply / Water distribution

Desarrollo del comportamiento proambiental en los individuos y sus determinantes

Este artículo analiza el comportamiento proambiental en individuos ofreciendo una clasificación del comportamiento según la diversidad/ intensidad de las acciones ambientales emprendidas, y explicando el desarrollo del comportamiento pro-ambiental y algunos de los factores que lo determinan. Mediante análisis cluster y modelos de ecuaciones estructurales, aplicado al Estudio 2837 del CIS, se obtiene una clasificación en cinco grupos de individuos que pone de manifiesto cómo se desarrolla el comportamiento pro-ambiental, desde niveles con poca intensidad en acciones medioambientales muy concretas (como el reciclado) hasta niveles de mayor implicación proambiental en un buen número de acciones proambientales. The aim of this study is to learn more about pro-environmental conduct in individuals, providing classification in levels of conduct according to diversity/intensity of environmental actions, showing how proenvironmental conduct develops in people and identifying the factors that determine such conduct. The application of cluster analysis and structural equation models to CIS Study 2837 classifies individuals with different degrees of environmental involvement into five groups, showing how pro-environmental conduct develops in people, from specific activities (such as recycling) performed with reduced intensity to greater and more intense pro-environmental involvement

Procesos de determinación social de la cultura alimentaria en población escolar de Cali, Colombia

Con el objetivo de analizar los procesos de determinación social de la cultura alimentaria en escolares de dos instituciones educativas de la ciudad de Santiago de Cali, se realizó un estudio cualitativo, aplicando el método hermenéutico, con un enfoque de determinación social de la salud y empleando técnicas y herramientas de análisis propias de este método. La información recolectada se obtuvo a partir de talleres con estudiantes de primaria, grupos de discusión con padres de familia, docentes y responsables de la tienda escolar, entrevistas a expertos en política y cultura alimentaria y revisión documental de la política alimentaria vigente. La construcción de la cultura alimentaria de los escolares es un proceso dinámico y complejo que inicia en la familia y la escuela, evidenciando tensiones entre el discurso hegemónico de alimentación saludable y el consumo mediado por el gusto, las nociones, el afecto y los modos de vida. Mientras la política se basa en el concepto de seguridad alimentaria y el enfoque social del riesgo, impidiendo que se garantice el derecho universal a la alimentación en un país en el que abundan las inequidades. Aunque padres y docentes se esfuerzan a diario por proteger a los escolares de las estrategias de la industria alimentaria con recursos que les permitan hacer mejores elecciones, la política alimentaria favorece la perpetuación de las relaciones de dominación. Para lograr mejores resultados en salud es indispensable empoderar a la comunidad y al personal de salud, para generar desde la sociedad acciones que promuevan una alimentación adecuada desde las primeras etapas del desarrollo