Why Improved Maize (Zea mays) Varieties are Utopias in the Highlands of Central Mexico

El obetivo de este trabajo consiste en el estudio de la adopción de variedades mejoradas de maíz en los Valles alto de México a través de los resultados del Programa Especial de Producción de Maíz del Estado de México (PEPMA). El trabajo comprende dos fases: el análisis estadístico de los datos del PEPMA y dos encuestas, seguidad por un trabajo de campo con entrevistas abiertas a los agricultores participantes de la población de San Pedro la Concepción en el Valle de Toluca. Los resultados muestran que la gran mayoría de agricultores continúa sembrando sus semillas autóctonas, los híbridos o las variedades mejoradas no son opciones técnicas reales en tanto que ellas no se desmpeñan bien en las condiciones de la zona de estudio.El obetivo de este trabajo consiste en el estudio de la adopción de variedades mejoradas de maíz en los Valles alto de México a través de los resultados del Programa Especial de Producción de Maíz del Estado de México (PEPMA). El trabajo comprende dos fases: el análisis estadístico de los datos del PEPMA y dos encuestas, seguidad por un trabajo de campo con entrevistas abiertas a los agricultores participantes de la población de San Pedro la Concepción en el Valle de Toluca. Los resultados muestran que la gran mayoría de agricultores continúa sembrando sus semillas autóctonas, los híbridos o las variedades mejoradas no son opciones técnicas reales en tanto que ellas no se desmpeñan bien en las condiciones de la zona de estudio

Effect of Supplementation of Dairy Cows under Cut and Carry or Grazing of Irrigated Cultivated Pastures in Small Scale Dairy Systems in the Highlands of Central Mexico

Small-scale dairy systems in Mexico represent over 78% of dairy farms and produce 37% of the nation’s milk, and have an important role in reducing rural poverty. Small-scale dairy systems are defined by having herds of 3 to 35 cows plus replacements, and rely mostly on the family for labour. In the central highlands, many small-scale dairy farms base the feeding of herds on irrigated cultivated pastures of ryegrass (Lolium multiflorum, L. perenne) – white clover (Trifolium repens), mostly under cut-and-carry by hand with scythes, straws, and large amounts of commercial compound concentrates that result in high feeding costs and low economic sustainability (Fadul-Pacheco et al., 2013). One option to optimize the use of resources in these systems is to change the use of grasslands to intensive grazing that result in lower feeding costs when compared to cut-and-carry strategies. Also, the high protein content of pasture may meet requirements for moderate yields by dairy cows, so that commercial concentrates may be substituted by lower protein, lower cost supplements like ground maize grain and remove the straws of the diets

Producción de leche en pastoreo de praderas cultivadas: una alternativa para el Altiplano Central

Se presentan resultados que definen a laResults that show milk production from an intensive grazing on cultivated pastures as a competitive and sustainable option for livestock production in Mexico’s central high plateau are presented. The objective of the projects integrated in this paper is the evaluation of the potential and the restrictions of ryegrass (Lolium perenne and L. multiflorum) and white clover (Trifolium repens) cultivated pastures, and that of an intensive grazing in order to increase the productivity of the farming systems. Results of the effects of the intensive grazing on milk yields, according to the type of pasture, the grazing system and the response to concentrate supplementation are reviewed. Intensive grazing on cultivated pastures allows the efficient and competitive production of milk at moderate levels and it is economically feasible since it represents lower production costs in comparison to the production under housing. The daily inclusion of legumes in the pastures has a positive effect in an ecological sense since it reduces the use of nitrogen fertilisers. Associated pastures also show the following advantages: they have a greater herbage accumulation, a better nutritive quality, and higher milk yields. Daily production systems based upon an intensive grazing on cultivated pastures, although representing an ample range of advantages in comparison to intensive housing systems, are not the only solution to all the problems of production

Construction of Social Sustainability in Milk Production Systems in Central Mexico

Objective: To build mathematical models to evaluate the social sustainability of small-scale milk production systems. Design/Methodology/Approach: Thirty small-scale cowsheds were analyzed. Two models were built using multivariate regression, estimated with ordinary least squares and considering the factors that producers perceive as important for social sustainability. Results: The first model (ER) included tangible variables and the second intangible variables (SR). Both models explained more than 80% of the variables associated with social sustainability. Study Limitations/Implications: The results represent an effort to link the statistical analysis with qualitative data that is difficult to quantify. Conclusions: The ER and SR models represent a proposal for counting immaterial indicators so they can be incorporated into the sustainability analysis. Both models could be a methodological proposal to connect statistical data with purely qualitative data such as perceptionThis study is part of the project with key 129449/2009 financed by CONACy

Understanding Factors Influencing Farmers’ Intention for Adopting Improved Grassland Using the Theory of Reasoned Action, in the Highlands of Central Mexico

Low adoption of improved grassland among small-scale dairy farmers has been attributed to different factors such as farmers and household characteristics, farm characteristics, institutional characteristics and capital constraints (Martínez-García et al., 2012). Several researchers illustrate the importance of farmers’ attitude, beliefs and social pressure from the salient referents in the adoption of innovations (Rehman et al., 2007; Rossi Borges et al., 2014). Regarding Mexico, there is a lack of information about understanding of attitudes, beliefs and social pressure underpinning farmers’ intentions to adopt agricultural innovations. In contrast to many adoption studies, it focuses on an innovation that has been successfully adopted. Therefore, the objective of this research was to understand factor influencing farmers’ intention for adopting improved grassland on their farms

The Dual Delivery of Y15 and Metformin in a PLGA Scaffold for the Treatment of Platinum Resistant Ovarian Cancer

Background: Ovarian cancer is the fifth leading cause of cancer mortality among women. This high mortality rate is linked to the development of resistance to first line chemotherapy with platinum compounds which has been attributed in part to increased activity of focal adhesion kinase (FAK). The anti-diabetic drug metformin was previously shown to induce cytotoxicity in PROC cells and thus, the combination of a FAK inhibitor, Y15 and metformin may be a promising treatment for PROC. Biomaterial scaffolds can be utilized to deliver drugs locally to maximize the drug concentration and bioactivity at the target site while minimizing non-target systemic exposure and toxicity. The Poly(lactic-co-glycolic acid) (PLGA) is an polyester copolymer and its degradation rate can be easily tailored from days to years providing versatility in the delivery of different drugs. The objectives of this study were to investigate the ability of the PLGA scaffold to control the release of the drugs and if the combined delivery of both Y15 and Metformin would result in additive effects on cell viability compared to the release of each drug alone. Methods: Scaffolds were fabricated from an easy and economical mold-less technique by combining PLGA and the drugs (i.e. metformin and/or Y15) in tetraglycol and injected in PBS, to form a globular morphology. Drug loading from the scaffolds were determined using HPLC at absorbance wavelengths of 233 and 376 nm for Metformin and Y15, respectively. Release kinetics were determined using a spectrometer at absorbance wavelengths of 233nm and 380nm for Metformin and Y15 respectively at each timepoint. An MTT assay was used to analyze cell viability in PROC OVCAR3 cells at an absorbance of 570 nm with a spectrometer. Results: Drug loading and loading efficiency for Metformin only and combination scaffolds were 0.577% and 0.584%, respectively and 6.35% and 6.45%, respectively. Drug loading and loading efficiency for Y15 were 0.059% and 0.064%, respectively, and 12.01% and 14.23%, respectively. A lot of drug was lost into the setting solvent during fabrication. This can be improved by optimizing the setting solvent for Metformin and Y15. A large burse release of the drug was observed from the drug encapsulated scaffolds. Incorporation of the drugs into particles prior to loading into the scaffolds may help reduce this burse release and result in a more sustained release of the drug. Metformin and Y15 treatment reduced cell viability by 34 and 46%, respectively, and 76% when combined. In studies with the fabricated PLGA scaffolds, Y15 only and metformin only scaffolds reduced cell viability by 36% and 11% respectively. When the drugs were combined in the scaffolds, there was a 95% reduction in cell viability. Although drug loading was low, it was still effective at resulting in cell death. Conclusion: In conclusion, the delivery of Y15 and Metformin in a PLGA biomaterial scaffold can result in an additive effect on cell viability and can be further explored as a promising approach for the treatment of PROC

IN VITRO NUTRITIONAL VALUE OF TRITICALE HAY ASSOCIATED WITH COMMON VETCH FOR SMALL SCALE DAIRY PRODUCTION SYSTEMS

Antecedentes. La disminución en la disponibilidad de agua de lluvia y riego afectan la producción de forraje, por ello se debe considerar la inclusión de cultivos con un ciclo de crecimiento más corto y con menor requerimiento de agua. Objetivo. El objetivo del trabajo fue realizar la evaluación nutricional de la asociación de dos forrajes; triticale y ebo para su posible inclusión en la alimentación del ganado lechero en sistemas de producción de leche en pequeña escala. Metodología. Se evaluaron dos tratamientos de la asociación de forrajes triticale/ebo: henificado (H) y no henificado (NH) mediante un análisis de varianza empleando un diseño experimental completamente al azar. Resultados. Se presentaron diferencias significativas (p0.05). Implicaciones. Ante el aumento en la temporada de sequía se hace necesaria la evaluación de otras formas de conservación del forraje que permitan aumentar su disponibilidad durante más tiempo. Conclusión. Los tratamientos evaluados no presentaron diferencias significativas en cuanto a su valor nutricional in vitro, por lo que se puede incluir en la alimentación del ganado lechero tanto como forraje conservado como heno o sin henifica

Informe sobre la producción científica de la UAEMEX en revistas iberoamericanas de acceso abierto en redalyc.org, 2005-2011

Objetivo: Proporcionar información sobre el Perfil de Producción Científica de la UAEMEX en revistas del acervo redalyc.org para el periodo 2005-2011, a fin de conocer cuáles son tanto las tendencias como el comportamiento de las estrategias de comunicación y de colaboración que registran los artículos producidos por los investigadores nacionales.Método: Se estudia la producción científica de 800 revistas iberoamericanas de acceso abierto durante 2005-2011, a partir de un modelo de análisis centrado en entidades de producción y comunicación, las cuales permiten generar un Perfil de Producción Científica según los indicadores de: Producción (P), Producción en Colaboración (PC) y Colaboración (C), aplicados a un núcleo de 145,515 artículos científicos que forman parte del acervo redalyc.org.Resultados: La información que constituye la producción científica de la UAEMEX durante 2005-2011, forma parte de un estudio más amplio realizado al acervo redalyc.org, el cual abarca a 13,414 instituciones de 146 países. La producción de la UAEMEX asciende a 1,196 artículos que corresponden a una aportación de 0.8% del total analizado. De estos, 20.2% fueron publicados en revistas extranjeras y en casi cuatro quintas partes en revistas nacionales; cuya distribución por área de conocimiento corresponde a 62.2% en ciencias sociales, 22.4% en ciencias, así como estudios multidisciplinarios y artes y humanidades en una proporción menor. Las disciplinas de la UAEMEX con mayor aporte a la producción científica de la universidad son política, multidisciplinarias, estudios territoriales y sociología, que concentran 45.3% de la producción institucional en el acervo. A su vez, casi dos terceras partes de los trabajos firmados por autores de esta institución se han realizado en colaboración (63.5%), sobre todo de tipo nacional e institucional (53.3%), donde la participación de investigadores extranjeros se vincula prioritariamente con España, Estados Unidos, Chile, Colombia y Brasil que, en conjunto, representan 68% de la producción de esta institución realizada en colaboración con universidades de otros países