Los procesos de construcción de conocimiento agroecológico y la transición hacia agricultura más sustentables en Jalisco, México

El presente trabajo parte de la noción de multifuncionalidad en la agricultura familiar sustentable, y se detiene a analizar la función cultural de la agricultura en la construcción de conocimiento agroecológico en dos experiencias de la región centro de Jalisco. Además, muestra la relevancia de las articulaciones entre diferentes actores sociales para formar redes de construcción e intercambio de conocimientos agroecológicos que fortalecen la transición hacia agriculturas más sustentables y más justas para los agricultores familiares.ITESO A

Effect of bentonite fining on polyfunctional mercaptans and other volatile compounds in Sauvignon blanc wines

Bentonite fining is the most common process used in the wine industry to remove proteins from wine. Herein, the influence of fermentative and post-fermentative fining on aroma compounds found in Sauvignon blanc wines was studied. Sauvignon blanc musts from different vintages were fined using bentonite. Conventional enological parameters, together with more than 60 volatile compounds, including varietal thiols, were determined in the bottled wines. The results showed that bentonite fining was more effective in removing proteins from wine when carried out on finished wines. Several volatile compounds were influenced by bentonite fining depending on the tim­ing of addition and the vintage. Varietal thiols, key compounds of Sauvignon blanc wine aroma, were significantly reduced when the wines were fined with bentonite, particularly when fining took place during fermentation. Results suggest that bentonite fining of musts could damage the organoleptic quality and varietal character of Sauvignon blanc wines because of its impact on polyfunctional mercaptans

An onto-semiotic approach to the normative dimension in mathematics education

Las nociones de contrato didáctico, norma social y sociomatemática son claves en distintas teorías didácticas, siendo diversa su conceptualización y ámbito de aplicación. En este trabajo teórico, después de hacer una síntesis de los variados modos de entender el contrato didáctico y las normas en didáctica de las matemáticas, presentamos una perspectiva que integra estas nociones como parte de una «dimensión normativa de los procesos de estudio». La consideración de esta perspectiva, desde un enfoque ontosemiótico, da lugar a una categorización de las normas según la faceta de los procesos de estudio a la que se refieren las normas: epistémica, cognitiva, interaccional, mediacional, afectiva y ecológica. Finalmente, mostramos cómo la aplicación de los criterios de idoneidad didáctica de un proceso de estudio se integran junto a las normas matemáticas, sociales y sociomatemáticas en la dimensión normativa, incorporando una racionalidad axiológica en el análisis didácticoThe concepts of didactical contract, social norms and socio-mathematical norms are very relevant in mathematics education, where they are conceptualized and applied in different ways and settings. In this article, we present a synthesis of various perspectives of norms and didactical contract as well as an onto-semiotic approach to these notions in order to include them as part of the «normative dimension» of teaching and learning processes. Using this approach we categorize the norms according the facet the norm refer to: epistemic, cognitive, interactional, meditational, affective and ecological. Finally, we apply the didactical suitability criteria to provide an axiological rationality to the didactical analysi

The effect of oxygen pickup during selective laser melting on the microstructure and mechanical properties of Ti–6Al–4V lattices

Additive manufacturing techniques such as Selective Laser Melting (SLM) can produce complex shapes with relatively thin sections and fine detail. However, common materials for the process, such as Ti–6Al–4V, have microstructure and properties that are sensitive to the pickup of interstitial impurities, such as oxygen, which the material will be exposed to during the process. This problem would be especially severe for parts with thin sections, where surface effects can be more significant, and where poor properties may coincide with locally-elevated stress. Here we explore the effects of oxygen level in thin sections with the use of lattice materials (materials which can be considered to consist exclusively of near-surface material). Oxygen levels are artificially raised using repeated melting passes to result in more pickup, leading to significantly reduced ductility and hence reduced strength measured in compression. A ductile to brittle transition in strut failure mechanism is found with increasing number of melting passes, with significant modification in chemistry and crystallographic structure, despite the presence of a similar fine plate-like microstructure throughout

Aproximación a la dimensión normativa en didáctica de las matemáticas desde un enfoque ontosemiótico

Las nociones de contrato didáctico, norma social y sociomatemática son claves en distintas teorías didácticas, siendo diversa su conceptualización y ámbito de aplicación. En este trabajo teórico, después de hacer una síntesis de los variados modos de entender el contrato didáctico y las normas en didáctica de las matemáticas, presentamos una perspectiva que integra estas nociones como parte de una «dimensión normativa de los procesos de estudio». La consideración de esta perspectiva, desde un enfoque ontosemiótico, da lugar a una categorización de las normas según la faceta de los procesos de estudio a la que se refieren las normas: epistémica, cognitiva, interaccional, mediacional, afectiva y ecológica. Finalmente, mostramos cómo la aplicación de los criterios de idoneidad didáctica de un proceso de estudio se integran junto a las normas matemáticas, sociales y sociomatemáticas en la dimensión normativa, incorporando una racionalidad axiológica en el análisis didáctico.The concepts of didactical contract, social norms and socio-mathematical norms are very relevant in mathematics education, where they are conceptualized and applied in different ways and settings. In this article, we present a synthesis of various perspectives of norms and didactical contract as well as an onto-semiotic approach to these notions in order to include them as part of the «normative dimension» of teaching and learning processes. Using this approach we categorize the norms according the facet the norm refer to: epistemic, cognitive, interactional, meditational, affective and ecological. Finally, we apply the didactical suitability criteria to provide an axiological rationality to the didactical analysis

Theoretical characterization of several models of nanoporous carbon

"Elastic, electronic and vibrational properties of seven models of nanoporous carbon are reported. The studied structures are periodic graphitic arrangements with heptagonal and octagonal rings of carbon, known as Schwarzites. The calculations were performed within a non-orthogonal tight binding framework which has been shown to be reliable for diamond, graphene layers, fullerenes and carbon nanotubes. In contrast with previous studies, each structure was properly relaxed, so that differences between each model must be assigned to intrinsic properties rather than to differences in their construction. Thermodynamic properties were calculated from the vibrational density of states.

Los conflictos socioambientales y la construcción de alternativas: experiencias de agricultura periurbana en el sur de la zona metropolitana de Guadalajara, Jalisco, México

El crecimiento desordenado de la zona metropolitana de Guadalajara, Jalisco, México, ha ocasionado una serie de conflictos socioambientales que impactan los recursos naturales y la calidad de vida de los habitantes del entorno periurbano. Ante ello, diversos actores locales se han orientado a construir alternativas a estos conflictos y allí es crucial el papel de la agricultura familiar periurbana, sustentable y multifuncional. En este trabajo se da cuenta de la experiencia del Instituto Tecnológico y de Estudios Superiores de Occidente, que lleva a cabo en la región un proyecto de acompañamiento e investigación participativa, donde se ha formado a los agricultores locales en la transición hacia agriculturas más sustentables, con el que se han demostrado las experiencias de agricultura periurbana, su viabilidad y sus aportaciones a la sustentabilidad regional, y se ha favorecido la articulación de los actores locales con organizaciones regionales y nacionales. Estos procesos se realizan en un tejido social fuerte que es la base para la construcción de alternativas a los conflictos socioambientales. The disordered sprawl of Guadalajara, Jalisco, Mexico has caused a number of environmental conflicts that impact the environment and quality of life of the residents of the suburban surroundings. In response, diverse local actors have focused on building alternatives to these conflicts where it is crucial the role of peri-urban, sustainable and multifunctional family agriculture. The Western Institute of Technology and Higher Education, holds in the region a project of accompaniment and participatory research, which has qualified local farmers in the transition to more sustainable agriculture and demonstrate the feasibility of the experiences of periurban agriculture and their contributions to regional sustainability, finally it has favored the articulation of local regional and national actors. These processes get done inside a strong social network which is the base to the construction of alternatives to socioenvironmental conflicts

Los conflictos socioambientales y la construcción de alternativas: experiencias de agricultura periurbana en el sur de la zona metropolitana de Guadalajara, Jalisco, México

El crecimiento desordenado de la zona metropolitana de Guadalajara, Jalisco, México, ha ocasionado una serie de conflictos socioambientales que impactan los recursos naturales y la calidad de vida de los habitantes del entorno periurbano. Ante ello, diversos actores locales se han orientado a construir alternativas a estos conflictos y allí es crucial el papel de la agricultura familiar periurbana, sustentable y multifuncional. En este trabajo se da cuenta de la experiencia del Instituto Tecnológico y de Estudios Superiores de Occidente, que lleva a cabo en la región un proyecto de acompañamiento e investigación participativa, donde se ha formado a los agricultores locales en la transición hacia agriculturas más sustentables, con el que se han demostrado las experiencias de agricultura periurbana, su viabilidad y sus aportaciones a la sustentabilidad regional, y se ha favorecido la articulación de los actores locales con organizaciones regionales y nacionales. Estos procesos se realizan en un tejido social fuerte que es la base para la construcción de alternativas a los conflictos socioambientales. The disordered sprawl of Guadalajara, Jalisco, Mexico has caused a number of environmental conflicts that impact the environment and quality of life of the residents of the suburban surroundings. In response, diverse local actors have focused on building alternatives to these conflicts where it is crucial the role of peri-urban, sustainable and multifunctional family agriculture. The Western Institute of Technology and Higher Education, holds in the region a project of accompaniment and participatory research, which has qualified local farmers in the transition to more sustainable agriculture and demonstrate the feasibility of the experiences of periurban agriculture and their contributions to regional sustainability, finally it has favored the articulation of local regional and national actors. These processes get done inside a strong social network which is the base to the construction of alternatives to socioenvironmental conflicts

Short communication: Effects of the addition of a marigold extract to diets fed to channel catfish (Ictalurus punctatus) on growth parameters

The expansion of aquaculture in the last 10 years has made it an important source of protein worldwide. However, increased production, and the culture intensification it carries, results in higher risk of infectious disease due to poor water quality and high stocking densities. ... Marigold (Tagetes erecta L.) is a plant native to Mexico whose flowers accumulate carotenoids. Natural carotenoids extracted from marigold have been used in aquaculture to help in the survival of fish juvenile stages by strengthening their immunological system, thus reducing mortality rates. The effect of carotenoids in fish health may exert a positive effect on fish growth indices; however, these effects on growth parameters have not been studied in channel catfish (Ictalurus punctatus), which is the most cultured fish species in north-eastern Mexico, and one of the most cultured on the southern United States. Consequently, the aim of this study was to investigate if there were significant differences in growth among channel catfish juveniles when fed diets containing various carotenoid doses from a natural source