Estimating lime requirements for tropical soils: Model comparison and development

Fernando Aramburu Merlos João Vasco Silva Frédéric Baudron Robert Hijmans (2023, [Artículo])

Acid tropical soils may become more productive when treated with agricultural lime, but optimal lime rates have yet to be determined in many tropical regions. In these regions, lime rates can be estimated with lime requirement models based on widely available soil data. We reviewed seven of these models and introduced a new model (LiTAS). We evaluated the models’ ability to predict the amount of lime needed to reach a target change in soil chemical properties with data from four soil incubation studies covering 31 soil types. Two foundational models, one targeting acidity saturation and the other targeting base saturation, were more accurate than the five models that were derived from them, while the LiTAS model was the most accurate. The models were used to estimate lime requirements for 303 African soil samples. We found large differences in the estimated lime rates depending on the target soil chemical property of the model. Therefore, an important first step in formulating liming recommendations is to clearly identify the soil property of interest and the target value that needs to be reached. While the LiTAS model can be useful for strategic research, more information on acidity-related problems other than aluminum toxicity is needed to comprehensively assess the benefits of liming.

Exchangeable Acidity Aluminum Saturation Calcium Carbonate Equivalent CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA CHEMICOPHYSICAL PROPERTIES LIMES TROPICAL ZONES ACID SOILS ALUMINIUM BASE SATURATION CALCIUM CARBONATE

On-farm storage loss estimates of maize in Kenya using community survey methods

Hugo De Groote Anani Bruce (2023, [Artículo])

Maize is the most important staple in sub-Saharan Africa (SSA), with highly seasonal production. High storage losses affect food security, but good estimations are lacking. A new method using focus group discussions (FGDs) was tested with 121 communities (1439 farmers, 52% women) in Kenya's six maize-growing zones, to estimate the maize losses to storage pests and analyze farmer practices. As control strategies, half of the farmers used chemical pesticides (49%), while hermetic bags (16%) and botanicals (15%) were also popular. Relative loss from weevils in the long rains was estimated at 23%, in the short rains 18%, and annually 21%. Fewer farmers were affected by the larger grain borer (LGB) than by maize weevils: 42% in the long rainy season and 32% in the short rainy season; losses from LGB were also smaller: 19% in the long season, 17% in the short season, and 18% over the year. Total storage loss, from both species combined, was estimated at 36%, or 671,000 tonnes per year. The greatest losses occur in the humid areas, especially the moist mid-altitudes (56%), and with smaller loss in the drylands (20–23%). Extrapolating the point data and overlaying with the maize production map shows the geographic distribution of the losses, with the most important area found around Lake Victoria. FGDs provide convenient and cheap tools to estimate storage losses in representative communities, but a total loss estimate of 36% is higher than is found in other studies, so its accuracy and framing effects need to be assessed. We conclude that storage pests remain a major problem, especially in western Kenya, and that the use of environmentally friendly technologies such as hermetic storage and botanicals needs more attention, both by the public extension service and private agrodealers.

Larger Grain Borer Maize Weevil CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA MAIZE STORAGE LOSSES PESTS SURVEY METHODS

From character to person. A contribution to the study of characterization of real people in factual narrative texts   

Martín Ignacio Koval (2023, [Artículo, Artículo])

In this paper we propose some arguments in favor of the terminological differentiation between agents in fictional settings (characters) and those in factual settings (people, actors, etc.), and nevertheless we suggest the applicability of the tools of narratology to factual journalistic texts. Then, we propose an analytical-descriptive model -conceived only as provisional- which, although it resorts to traditional tools of narratology "in the strict sense" (that is, the one that deals exclusively with fictional texts), tries to do justice to the aforementioned categorical difference between fictional and factual texts insofar as it is accompanied, in the presentation, by a series of mediations that allow the extrapolation from one setting to the other. This model will be explained on the basis of the analysis of a fragment of a recently published journalistic chronicle, referring to the death of the Argentine soccer player Diego Maradona.

factualidad personaje persona caracterización reacción afectiva HUMANIDADES Y CIENCIAS DE LA CONDUCTA HUMANIDADES Y CIENCIAS DE LA CONDUCTA Factuality character person characterization affective reaction

Tensile behavior of 3D printed polylactic acid (PLA) based composites reinforced with natural fiber

Eliana M Agaliotis BALTAZAR DAVID AKE CONCHA ALEJANDRO MAY PAT Juan Pablo Morales Arias Celina Bernal Alex Valadez González Pedro Jesús Herrera Franco Gwenaelle Proust JUAN FRANCISCO KOH DZUL José Gonzalo Carrillo Baeza Emmanuel Alejandro Flores Johnson (2022, [Artículo])

Natural fiber-reinforced composite (NFRC) filaments for 3D printing were fabricated using polylactic acid (PLA) reinforced with 1–5 wt% henequen flour comprising particles with sizes between 90–250 μm. The flour was obtained from natural henequen fibers. NFRCs and pristine PLA specimens were printed with a 0° raster angle for tension tests. The results showed that the NFRCs’ measured density, porosity, and degree of crystallinity increased with flour content. The tensile tests showed that the NFRC Young’s modulus was lower than that of the printed pristine PLA. For 1 wt% flour content, the NFRCs’ maximum stress and strain to failure were higher than those of the printed PLA, which was attributed to the henequen fibers acting as reinforcement and delaying crack growth. However, for 2 wt% and higher flour contents, the NFRCs’ maximum stress was lower than that of the printed PLA. Microscopic characterization after testing showed an increase in voids and defects, with the increase in flour content attributed to particle agglomeration. For 1 wt% flour content, the NFRCs were also printed with raster angles of ±45° and 90° for comparison; the highest tensile properties were obtained with a 0° raster angle. Finally, adding 3 wt% content of maleic anhydride to the NFRC with 1 wt% flour content slightly increased the maximum stress. The results presented herein warrant further research to fully understand the mechanical properties of printed NFRCs made of PLA reinforced with natural henequen fibers. © 2022 by the authors.

POLYLACTIC ACID (PLA) NATURAL FIBER HENEQUEN FIBER NATURAL FIBER REINFORCED COMPOSITE (NFRC) ADDITIVE MANUFACTURING 3D PRINTING MECHANICAL PROPERTY INGENIERÍA Y TECNOLOGÍA CIENCIAS TECNOLÓGICAS TECNOLOGÍA DE MATERIALES PROPIEDADES DE LOS MATERIALES PROPIEDADES DE LOS MATERIALES

El amaranto o huauhtli sagrado del México prehispánico y alimento de alto valor nutricional del México contemporáneo

JESUS ALFREDO ARAUJO LEON Ivonne Sánchez del Pino Víctor Aguilar Hernández SERGIO RUBEN PERAZA SANCHEZ ROLFFY RUBEN ORTIZ ANDRADE ANDRES XINGU LOPEZ Ligia Guadalupe Brito Argáez J. NAHIM ALCOCER ESPEJEL (2023, [Artículo])

El amaranto o huauhtli es uno de los alimentos más versátiles y nutritivos del continente americano. Los frailes españoles documentaron en sus crónicas del siglo XVI, la amplia variedad de platillos que los mexicas elaboraban con huauhtli. También destaca la importancia de las semillas de amaranto en las prácticas religiosas y su uso en la elaboración de imágenes sagradas (principalmente comestibles) para los dioses. El amaranto fue importante para la agricultura, la gastronomía y los rituales del México antiguo. El presente ensayo documenta la historia del amaranto en las ceremonias mexicas y su importancia como "súper alimento" en la actualidad

AMARANTHUS HYPOCHONDRIACUS ALEGRIAS SUPER ALIMENTO MEXICAS HERENCIA PREHISPANICA BIOLOGÍA Y QUÍMICA CIENCIAS DE LA VIDA BIOLOGÍA VEGETAL (BOTÁNICA) ECOLOGÍA VEGETAL ECOLOGÍA VEGETAL

Uso y manejo de drones con aplicaciones al sector hídrico

WALDO OJEDA BUSTAMANTE Jorge Flores Velazquez RONALD ERNESTO ONTIVEROS CAPURATA (2016, [Libro])

La motivación de este libro es ofrecer un compendio de los principios, metodologías y aplicaciones de los drones con énfasis en ingeniería hidroagrícola. Con este objetivo se conformó un equipo multinstitucional y multidisciplinario para presentar de manera concisa y simple los principios físicos asociados a los sensores remotos, además de describir los componentes y actividades necesarios para realizar misiones que permitan obtener imágenes y videos de alta resolución.

Aviones no tripulados Infraestructura hidroagrícola Percepción remota CIENCIAS AGROPECUARIAS Y BIOTECNOLOGÍA

Metodología para la delimitación y caracterización de humedales en escalas 1:50 000 y 1:20 000

JORGE ENRIQUE BRENA ZEPEDA Ana Wagner (2016, [Artículo])

Se analiza la situación retrospectiva y actual de los humedales localizados en la zona de la Vertiente Pacífica del estado de Chiapas, México. Se aplicaron técnicas de percepción remota empleando imágenes satelitales tomadas en 1986, 2004 y 2010 que, junto con cartografía temática digital procesada en un sistema de información geográfica, permitió la evaluación prospectiva del comportamiento tendencial de los humedales al año 2030. Como resultado se obtuvo una metodología para delimitar humedales en escalas 1:50 000 y 1:20 000, los mapas de uso de suelo y vegetación de las tres cuencas que integran la zona de estudio y un mapa tendencial para el año 2030. Del análisis temporal de las coberturas, su localización y la morfología del relieve se detectaron problemas y amenazas. Se elaboró un mapa de áreas críticas para orientar acciones de recuperación ambiental, reducir la erosión y el riesgo de deslizamientos que amenazan a localidades específicas. Se concluye que el diagnóstico de salud ambiental de un humedal refleja los efectos de las acciones llevadas a cabo en las diferentes partes de una cuenca. La información obtenida es básica para evaluar estrategias sectoriales y desarrollar un plan de manejo integral de los recursos que promueva el crecimiento económico de la región y su aprovechamiento sustentable.

Humedales Percepción remota Gestión integrada de recursos hídricos CIENCIAS FÍSICO MATEMÁTICAS Y CIENCIAS DE LA TIERRA

Una articulación fundamental: la emancipación

Nicolás Amoroso Boelcke (2023, [Capítulo de libro])

El concepto, la circunstancia de la enseñanza que aquí abordaremos, tiene el propósito de restituir ciertas situaciones que corresponden al propio ejercicio de la instrucción y a aquellas otras que hablan del acontecer, por ello el trabajo. Tiene las variables tanto de la experiencia real como de las otras sobre las que se han escrito, una de ellas, al final, plantea una situación paradójica que se refiere a la del maestro ignorante que, básicamente, tiene como propósito mostrar que el conocimiento es algo que está en el alumno y que el docente debe limitarse a tratar de que aflore y se exprese de la mejor manera posible. Nos habla de la independencia y de las características que puede tener una educación rigurosa y rígida, en contraposición con una más flexible. Lo mismo sucede con el pensamiento desde nuestra América, de la educación dependiente a una educación libertaria.

The concept, the circumstance of the teaching that we will address here has the purpose of restoring certain situations that correspond to the exercise itself as those others that speak of the happening for it the work. It has the variables of real experience as of the others about which they have been written, one of them, in the end, poses a paradoxical situation that refers to that of the ignorant teacher that, basically, has the purpose of showing that knowledge is something that is in the student and that the teacher must limit himself to trying to bring it out and express itself in the best possible way. It tells us about independence and the characteristics that a rigorous and rigid education can have with a more flexible one and the same happens with the thought from our America, from dependent education to a libertarian education.

Emancipación, docencia, alumnos, investigación, juego. Emancipation, teaching, students, research, play. Interaction analysis in education. Microteaching. Teacher-student relationships. Transformative learning. Educational innovations. Análisis de interacción en la educación. Relaciones maestro-estudiante. Aprendizaje transformador. Cambio educativo. LB1034 HUMANIDADES Y CIENCIAS DE LA CONDUCTA PEDAGOGÍA TEORÍA Y MÉTODOS EDUCATIVOS

“We place our hope in the land”: defense of the territory against mining in Ixtacamaxtitlán, Puebla

Veronica Vazquez_Garcia Esteban Martínez Vásquez (2023, [Artículo, Artículo])

Mexico occupies first place in mining exploration in Latin America, a situation that has caused alarm among native peoples because the implementation of extractive projects threatens their vital space. The objective of this paper is to analyze the actions of Corporate Social Responsibility (CSR) of the Ixtaca Project in Ixtacamaxtitlán, Puebla, as well as the strategies of territorial defense undertaken by the communities to stop its expansion. Data was gathered through one survey, one workshop and various interviews conducted in three communities affected by the project. Results discuss three actions of CSR: 1) job offers; 2) investment in community infrastructure; 3) support for social events. Three main defense strategies were identified: 1) collective agreements refusing to sell water to the company; 2) legal litigations in favor of the right to be consulted as native peoples; 3) the strengthening of peasant agriculture thanks to the defense of the ejido, the conservation of irrigation water and the support received from the federal program Sembrando Vida. The paper concludes that, despite the negative impacts of RCS actions, these strategies have proven effective because mining concessions have been cancelled and some families have returned to agriculture.  

native peoples peasantry mining OIT Convention socioenvironmental conflict pueblos originarios campesinado minería Convenio OIT conflicto socioambiental CIENCIAS SOCIALES CIENCIAS SOCIALES

Observatorio de conflictos por el agua en México

Ricardo Víctor López Mera EDUARDO LOPEZ RAMIREZ Gemma Millán (2015, [Documento de trabajo])

Este proyecto tuvo como fin construir y diseñar un sitio web para poder visualizar la problemática y conflictividad por el agua en México. Es decir, por un lado, ofrecer una herramienta de fácil acceso a las personas interesadas en estudiar y debatir sobre el tema. Por el otro, proponer una metodología basada en fuentes hemerográficas que ayude a localizar, entender y analizar las partes que componen un conflicto asociado al agua.

Conflictos por agua Sitios web Artículos periodísticos Informes de proyectos CIENCIAS SOCIALES