Sistema Regional de Información
en línea para Revistas Científicas de América Latina,
el Caribe, España y Portugal

La modelación de la dinámica del carbono orgánico del suelo (COS) es una tarea crítica para analizar proyecciones de emisiones de CO2 asociadas al cambio de uso del suelo y vegetación (USyV). El modelo COLPOS fue desarrollado para estimar la distribución del COS asociado a fracciones físicas del suelo, pero no fue extendido a una versión dinámica. En este trabajo se presenta el desarrollo del modelo dinámico COLPOS, generado a partir de una revisión de las soluciones de las ecuaciones diferenciales ordinarias de modelos de dinámica del COS con dos almacenes, uno activo y otro inerte. Con el uso de cronosecuencias de cambios de USyV, donde se separaron los procesos de descomposición y absorción del COS mediante el uso de técnicas que emplean un isótopo estable (13C), se realizó un ajuste del modelo desarrollado, obteniéndose resultados satisfactorios (R2 > 0.9). El modelo dinámico COLPOS solo tiene un parámetro de ajuste y fue formulado con base en datos medibles en laboratorio, por lo que su uso operacional es viable.

Ecuador es un país privilegiado por sus condiciones geográf icas y climáticas, que le permiten ser uno de los mayores productores de cacao f ino y de aroma a escala mundial. Una de las limitantes más importantes para su cultivo son las enfermedades fungosas, como el f itopatógeno Moniliophthora perniciosa, que causa grandes pérdidas en la producción cacaotera. Esta investigación tuvo como objetivo evaluar el riesgo del cultivo de cacao ante los cambios de distribución geográf ica potencial de M. perniciosa bajo escenarios de cambio climático en Ecuador continental. Se obtuvieron datos de presencia del patógeno de la literatura científ ica y Niche Toolbox, y con variables bioclimáticas, seleccionadas de acuerdo con su ecología, se modeló su distribución potencial con MaxEnt. Con los mapas binarios del f itopatógeno y la capa de uso del suelo para el cultivo de cacao, se determinaron los sitios donde ambas especies coinciden espacialmente. El modelo de M. perniciosa fue transferido a Ecuador continental en el presente y a diferentes escenarios de cambios climático. El área de distribución del patógeno fue comparada entre los escenarios actuales y futuros para identif icar las pérdidas, ampliaciones y estabilidad. El mayor rango de ampliación y contracción se da en el escenario extremo RCP 8.5 2070, con 10 392 km2 y 540 km2 respectivamente. Hay un mayor rango de estabilidad durante los escenarios futuros RCP 4.5 2050 con 30 929 km2 y 2070 con 30 908 km2. Actualmente, el f itopatógeno se distribuye de manera potencial en el 74 % del área ocupada por plantaciones de cacao y en el futuro todos los escenarios indican un aumento. Las medidas de prevención, manejo y control deben incrementarse para mantener estable la producción de cacao y no afectar la economía a nivel nacional, ni de las familias de los productores.

There is a need to replace components of substrates for the development of seedlings in forest nursery, with low-cost products and especially with local and renewable materials. Sugarcane bagasse biochar is lightweight, porous and has a high-water retention capacity. Therefore, the objective of this study was to evaluate the response of biochar based on sugarcane bagasse to produce white pine (Pinus greggii Engelm. ex Parl) plants under nursery conditions. Four treatments were evaluated: (a) biochar with forest soil, (b) forest substrate (composed of 12.5% peat moss, 12.5% agrolite, 25% vermiculite, 50% pine bark), (c) biochar with forest substrate, both in a 1:9 ratio (biochar:soil, biochar:substrate), and (d) forest soil. The effect of fertilization (N, P and K) and biochar on the performance of treatments in soil and forest substrate was evaluated. The growth variables evaluated were plant height, stem diameter, total aerial biomass, total root biomass, aerial/root biomass ratio, and the concentration of accumulated nutrients (N, P, Ca, K, Na and Mg) in the aerial and root parts. The results obtained indicate that as a consequence of the addition of biochar to the soil and fertilization, the height, diameter, biomass (aerial and total) of Pinus greggii were similar to obtained in forest substrate, alone or combined with biochar. These results were associated with the addition of biochar to the soil that increased the absorption of N and its concentration in the aerial biomass, and favored the availability of Mg, Ca, K and P, these last two elements added in fertilization. It is concluded that the combination of biochar and soil in a ratio (1: 9) (p/p) with the addition of fertilizer (N, P and K) can be used in the development of Pinus greggii Engelm ex Parl in the nursery.

The purpose of this report is to systematize the experience with active methodologies within the technical training of community health agents of the Federal University of Paraíba's Technical School of Health. The course is organized in stages, the first of which has already been completed and was aimed at contributing to building the identity of the community health agents. Applying active methods leads students to reflect on their work process and transform their reality, benefiting from it, given that it awakens a critical sense and the pursuit of changes in their relationships with themselves, with the user, and with the community at large. The results were positive, including with regard to strengthening the use of active methods in the teaching-learning process used at the school providing the training.

This study sought to investigate and understand the violence experienced in basic health units (UBS) from the perspective of the work processes carried out in health. The characterization of the violence existing in this context, achieved by identifying and understanding the elements that cause this phenomenon, contributes to combating it. Descriptive and exploratory, this study gathered data from focus groups and interviews carried out among health service users, employees and managers. The investigation shows the consequences and impacts of violence in the UBSs, portraying attitudes generated by episodes of violence, as well as preventive actions and mechanisms of support and assistance. The analysis of the results shows not only there is a need both to strengthen the humanization and management of the work in health and to train the area's professionals, but also that these actions should be linked to improved workplace environment and conditions and, thus, better health service provision.

José Paulo Netto is Professor Emeritus at the Federal University of Rio de Janeiro (linked to the School of Social Service) and a known Brazilian Marxist intellectual. Holding a Doctorate in Social Work, Netto stands out as the author of works that have also outlined Marxist thought in a didactic manner and without any reductionism. Among these works, we mention "O que é marxismo" (Brasiliense), more recently "Economia política: uma introdução crítica," in coauthorship with Marcelo Braz (Cortez), and the volume, with the collaboration of Miguel Yoshida, from Marx-Engels, "Cultura, arte e literatura: textos escolhidos" (Expressão Popular). With Carlos Nelson Coutinho, he organized three volumes of texts written by G. Lukács ("O jovem Marx", "Socialismo e democratização" and "Arte e sociedade", all by Editora UFRJ).   In this interview, Netto discusses, mainly, dialectics under the Marxist framework, understanding it both as a method of apprehending reality and as the movement of the real. To Netto, although Marx did not write much on the subject, he is an essential benchmark for those who today are looking to analyze and transform reality objectively. In line with this theme, the interview also deals with the relationship between theory and practice, the potential of scientific knowledge, and the contemporary academic logic.

Sociologist Danièle Linhart is a professor at Paris X Nanterre University and a researcher at the National Center for Scientific Research (NCSR), which has ties to the GTM/CRESSPA Laboratory of Gender, Work, and Mobility, at the Paris Center for Sociological and Political Research. She conducts research on the changes in the organization and management of work at modern enterprises, and has authored several books dealing with this issue, such as the collection published in Brazil in 2007 titled A desmedida do capital (The imbalance of capital). She is the coordinator, in France, of the Capes-Cofecub international cooperation agreement that involves the College of Education of the University of Campinas (Unicamp). This interview took place in ambit of the development of activities relating to the cooperation between the Oswaldo Cruz Foundation (Fiocruz) and CNRS with regard to studies on the relationship among gender, health, and work. In this interview, Linhart discusses what she calls the difficulty of work, analyzing the modernization processes that are currently underway. She also deals with subjective aspects of the present productive world, and reflects on the recent cases of suicide in French companies.

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