Views on sustainability and the willingness to adopt an environmental management system in the Mexican vegetable sector

In Mexico, agriculture’s main environmental problems are related to water resources, deforestation and soil erosion. These problems are more acute in arid or semiarid regions such as in the state of Zacatecas. Environmental management systems (EMS) can be an alternate means for improving environmental conditions. In this study, factors that determine willingness to adopt an EMS in the vegetable production units of the state of Zacatecas were identified. We also analysed views on sustainability and production practices oriented toward environmental management and care of natural resources, as well as drivers and barriers to EMS adoption. Factors determining EMS adoption were level of education, awareness of the importance of caring for and protecting natural resources, application of agricultural practices oriented toward protecting the environment, and ignorance of environmental problems

Oscillation tomografy study of Earth's composition and density with atmospheric neutrinos

Knowledge of the composition of the Earth's interior is highly relevant to many geophysical and geochemical problems. Neutrino oscillations are modified in a non-trivial way by the matter effects and can provide valuable and unique information not only on the density but also on the chemical and isotopic composition of the deep regions of the planet. In this paper, we re-examine the possibility of performing an oscillation tomography of the Earth with atmospheric neutrinos and antineutrinos to obtain information on the composition and density of the outer core and the mantle, complementary to that obtained by geophysical methods. Particular attention is paid to the D$^{\prime \prime}$ layer just above the core-mantle boundary and to the water (hydrogen) content in the mantle transition zone. Our analysis is based on a Monte-Carlo simulation of the energy and azimuthal angle distribution of $\mu$-like events generated by neutrinos. Taking as reference a model of the Earth consisting of 55 concentric layers with constant densities determined from the PREM, we evaluate the effect on the number of events due to changes in the composition and density of the outer core and the mantle. To examine the capacity of a detector like ORCA to resolve such variations, we construct regions in planes of two of these quantities where the statistical significance of the discrepancies between the reference and the modified Earth are less than $1\sigma$. The variations are implemented in such a way that the constraint imposed by both the total mass of the Earth and its moment of inertia are verified.Comment: Already published in the European Physical Journal

Assessing Environmental Management of Tomato Production under Protected Agriculture

This study examines the impact of environmental strategies on profitability of protected agriculture production systems in the state of Zacatecas, Mexico using the approach of Total Quality Environmental Management (TQEM) and Total Cost Assessment (TCA). We identified environmental management practices currently used by production units and analyzed the existing situation, plus two hypothetical scenarios. Profitability indicators show that adopting conservation production practices will not only improve the image of the organization but permit better access to markets, maintain positive profitability and contribute to the conservation of natural resources

Total cost assessment of greenhouse tomato production in Zacatecas, Mexico

Agriculture in the state of Zacatecas, Mexico, consumes 77% of the available groundwater. In this region, the main source of water is 34 aquifers, of which 44% are over exploited. Over extraction of the aquifers damages the environment, increases pumping costs and decreases water quality. Greenhouse tomato production systems have increased considerably in recent years. Besides the environmental problems that agriculture generates, there is also the problem of emissions and solid waste. The objective of this paper is to assess the environmental impact on profitability of protected agriculture systems in the state of Zacatecas. The methodology used was total cost assessment. This study assesses the total cost of four production units in their present situation, as well as in two scenarios: one denominated sustainable and the other unsustainable. Profitability indicators in the sustainable and unsustainable scenarios show that adopting conservation production practices, besides improving the image of the organization and permitting better access to markets, will maintain profitability and contribute to the conservation of natural resources

Earth tomography with atmospheric neutrino oscillations

The study of the flux of atmospheric neutrino crossing the Earth can provide useful information not only on the matter density of the different layers that make up the planet but also on their chemical composition. The key phenomenon that makes this possible is flavor oscillations and their dependence on the electron density along the neutrino baseline. To extract the relevant information, we simulate the energy and azimuth angle distribution of events produced in a generic neutrino telescope by atmospheric neutrinos passing through the deepest parts of the Earth. Changes in the densities of the outer core and the mantle are implemented by varying the location of the boundary between these layers so that the restrictions on the mass of and the moment of inertia of the Earth are both satisfied. This allows us to examine the effect of simultaneous changes in composition and density of the outer core, unlikely other works on the subject, where only one of these quantities was varied.Fil: D'Olivo, Juan Carlos. Universidad Nacional Autónoma de México. Instituto de Ciencias Nucleares; MéxicoFil: Herrera Lara, José Arnulfo. Universidad Nacional Autónoma de México. Instituto de Ciencias Nucleares; MéxicoFil: Romero, Ismael. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; ArgentinaFil: Sampayo, Oscar Alfredo. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; ArgentinaFil: Zapata, Gabriel Damián. Consejo Nacional de Investigaciones Científicas y Técnicas. Centro Científico Tecnológico Conicet - Mar del Plata. Instituto de Investigaciones Físicas de Mar del Plata. Universidad Nacional de Mar del Plata. Facultad de Ciencias Exactas y Naturales. Instituto de Investigaciones Físicas de Mar del Plata; Argentin

Evaluation of Different Concentrations of Nitrogen for Tomato Seedling Production (Lycopersicon esculentum Mill.)

This study was aimed at evaluating the different concentrations of nitrogen for tomato seedling production (Lycopersicon esculentum Mill.), hybrid Loreto. Five concentrations of nitrogen were analyzed: 0, 4, 8, 12 and 16 mEq / L, using as a basis the Steiner nutrient solution. A pilot randomized block design was used with six replications and five treatments. Thirty-five days after sowing, the following variables were analyzed: seedling height, stem diameter, fresh stem weight, fresh leaf weight, leaf area, dry steam weight, dry leaf weight, dry root weight and total nitrogen content. An ANOVA analysis (p <0.05) with post-hoc Tukey test was performed to compare each treatment variables. The results showed that the increase in the concentration of nitrogen has a positive effect on organ growth. The treatment with the highest values in the morphological variables was 16 mEq / L, which shortened the production time of seedlings ready for transplant

Evaluation of Different Concentrations of Nitrogen for Tomato Seedling Production (Lycopersicon esculentum Mill.)

This study was aimed at evaluating the different concentrations of nitrogen for tomato seedling production (Lycopersicon esculentum Mill.), hybrid Loreto. Five concentrations of nitrogen were analyzed: 0, 4, 8, 12 and 16 mEq / L, using as a basis the Steiner nutrient solution. A pilot randomized block design was used with six replications and five treatments. Thirty-five days after sowing, the following variables were analyzed: seedling height, stem diameter, fresh stem weight, fresh leaf weight, leaf area, dry steam weight, dry leaf weight, dry root weight and total nitrogen content. An ANOVA analysis (p <0.05) with post-hoc Tukey test was performed to compare each treatment variables. The results showed that the increase in the concentration of nitrogen has a positive effect on organ growth. The treatment with the highest values in the morphological variables was 16 mEq / L, which shortened the production time of seedlings ready for transplant

Alternativas física, química y natural para controlar Meloidogyne spp. en tomate de invernadero

El objetivo del presente trabajo fue evaluar la efectividad de control de Meloidogyne spp., mediante la utilización de alternativas física, química y natural, la física con solarización, la química con el nematicida Vidate y la natural mediante la plantación intercalada de cempasúchil (Tagetes erecta) entre plantas de tomate, así como la combinación entre las alternativas empleadas. El experimento se llevó a cabo en un invernadero comercial, ubicado en la comunidad de Chaparrosa, municipio de Villa de Cos, Zacatecas, en el año 2012. Se usó un diseño experimental en bloques completos al azar con cuatro repeticiones y unidades experimentales de una planta. Se aplicó agua, fertilizante y otros agroquímicos mediante goteo, con el manejo que el productor hace normalmente. Se midieron 12 variables, resultado de conteo de nematodos, racimos y peso de fruto en diferentes fechas. El análisis de varianza detectó diferencias estadísticas significativas en siete de las variables; con los resultados y el análisis de correlación que se realizó entre las variables, se concluyó que, con la inclusión de una planta de cempasúchil intercalada entre plantas de tomate, así como este tratamiento combinado con la solarización, se obtuvo el menor número de nematodos y el mayor rendimiento de frutos

Temperature Sensing Characteristics of Tapered Doped Fiber Amplifiers

We numerically analyze the temperature response of tapered doped fiber amplifiers and discuss their feasibility to be used as a sensing element in temperature fiber sensors. In particular, we consider Ytterbium (Yb) and Thulium (Tm) rare earths in the tapered doped fiber designs. We have modified the coupled propagation equations for the pump and signal radiations in order to include different taper structures and introduce the temperature dependence of the absorption and emission cross-sections of Yb and Tm ions. It was found that the temperature sensitivity of the amplified signal in Tm-doped fiber amplifiers is one order of magnitude higher than this obtained with Yb-doped fibers. Additionally, in all doped fibers, the temperature sensitivity of the signal radiation is higher for low pump powers in a co-propagating pump scheme, and it highly depends on the longitudinal shape of the taper used. Finally, for both Yb- and Tm-doped fibers, the temperature sensitivity can be increased if we use doped fiber lengths shorter than 1 m and pump powers lower than 300 mW. This study provides valuable information for the development of tapered fiber amplifiers doped with other rare earths and novel designs for doped fiber temperature sensors