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

La demarcació de la frontera és una part fonamental de l'inici d'aquesta, però ha estat molt escassament estudiada. A penes hi ha treballs sobre la qüestió, i en la major part dels treballs sobre fronteres es resol amb una breu al·lusió als marcs o les fites dels quals consten. La demarcació sol interpretar-se que constitueix veritablement el punt final de la fixació de la frontera, i té un efecte directe  sobre el “paisatge fronterer” (borderscape). Però la demarcació és un procés en el qual els Estats sovint troben resistències de les poblacions locals, que mostren el grau del seu acord o rebuig al traçat de la frontera. Abordarem aquest estudi en el cas de la frontera hispano-portuguesa, la ratlla/raia, des de l'amollonament fins al manteniment, a escala local i estatal.

En aquest article suggerim interpretar la migració com a factor geopolític, un factor que no aquesta sempre subjecte a les decisions estatals.  Realitzem una revisió de la literatura sobre la geopolítica de les migracions, sobretot centrat en el control migratori, identificant els seus limitis i potencialitats. Després, presentem l'Autonomia de les Migracions com una manera de complementar o reptar conceptes assumits dins la literatura de la geopolítica de les migracions com la primacia analítica de les actuacions dels estats en matèria migratòria.  Sobre la base del treball de *Yann *Moulier *Boutang, proposem parar esment a la capacitat pròpia dels moviments migratoris per a intervenir en transformacions estructurals de tipus econòmic, polític, cultural i legal. Aquest enfocament en les migracions com a factor geopolític pot guiar futures recerques i enriquir la nostra comprensió de les transformacions a les fronteres i de la geopolítica mateixa.

Botanical extracts are widely used for the control and management of pests in agriculture. However, very little is known about their ef fect on the control of green aphid (Myzus persicae) and whitef ly (Bemisia tabaci). M. persicae and B. tabaci are species that are highly detrimental to the pepper crop due to their sucking habit and because they are disease vectors. This study aimed to evaluate the insecticidal ef fect of extracts of rue (Ruta graveolens), onion (Allium cepa), marigold (Tagetes sp.), and mint (Mentha pulegium) as an ecological alternative for the control of green aphids and whitef lies in pepper crop. Pepper seedlings were transplanted in the f ield and distributed using a randomized block design with f ive treatments (T1: rue extract; T2: onion extract; T3: marigold extract; T4: mint extract; T5: control (Imidacloprid) and three replications. The parameters evaluated were the percentage of incidence, density, and population f luctuation of M. persicae and B. tabaci in the pepper crop, as well as its ef fect on the agronomic and productive variables. The use of botanical extracts of rue, onion, marigold, and mint reduced the incidence and population density of M. persicae and B. tabaci in pepper crops. However, the insecticidal action of rue and marigold were signif icantly evident for B. tabaci (P < 0.05). The population f luctuation of M. persicae and B. tabaci was altered by using botanical extracts. The application of extracts of rue, onion, marigold, and mint did not inf luence the weight and diameter of the fruit, nor af fect the pepper crop (P > 0.05). Therefore, its use should be considered in management programs and agroecological control of these pests.

Yam cultivation is of high importance for the food security of rural families in the Caribbean region of Colombia. One of the main technological problems faced by small yam producers is the low quality and availability of seed for planting. The present work was carried out to evaluate the technology of minitubers production in yam seedlings generated from cuttings, by induction with rhizobacteria. For this purpose, the phytohormone production capacity of three rhizobacteria, identif ied with the codes DCR11 (Azotobacter vinelandii), DSC21 (Brevibacillus laterosporus), and DSC1 (Bacillus licheniformis), was initially evaluated in vitro, and once their capacity was verif ied, an experiment was established under mesh house conditions to induce, with rhizobacteria, the production of mini-tubers in yam seedlings under three levels of shading. A completely randomized experimental design with subdivided plots and three replications was used, where the main plot corresponded to the shade levels (0, 65 and 80%), the subplots to the rhizobacteria (DCR11 A. vinelandii, DSC1 B. licheniformis, DSC21 B. laterosporus), and the sub-subplots at the inoculum doses (0, 2, 4 and 6 mL pl-1). The in vitro results demonstrated the potential of rhizobacteria to produce cytokines and auxins. In mesh house, the capacity of yam seedlings to produce mini-tubers was demonstrated, where the rhizobacteria DSC1 B. licheniformis and DSC21 B. laterosporus showed greater induction capacity. The results demonstrated the feasibility of minitubers production in yam seedlings under mesh house conditions by induction with rhizobacteria, and therefore, its validation at a semi-commercial level is recommended as a strategy for mass production of yam minitubers, as an alternative for the planting of commercial crops.

The formation of soils from hardened layers of volcanic origin -tepetates- broken, depends on the management system that is used to enable it to be implemented for agricultural or livestock use, so the development of models that allow understanding the transformation of structural units, from fragments to aggregates, is of great importance. From this perspective, the present work proposes and justifies the use of a kinetic model of order n, to model the distribution of mass and organic carbon in the structural units of tepetates under cultivation and predict their evolution towards soil formation. The validation of the model and the proposed relationships were carried out from the comparison of the dynamics of structuring in tepetate, with different case studies, which include substrates with different characteristics, such as soils, degraded soil and loamy marl. The modeling results were highly favorable (R2 > 0.98). The temporal evolution of the cementing agent in the substrates -organic carbon- as well as structural stability, according to the proposed model define patterns that are directly associated with the evolution of soil formation with the level of aggregation. In short-term experiments (≤ 2 years), the analyses highlight the participation of other agents, in addition to organic carbon, that control the mechanisms of aggregation, so an extension of the proposed model was reviewed, to consider this scenario.

Some of the limitations for plant acclimatization in vitro in banana cultivation have been poor rooting and slow leaf development, which affect survival in the f ield under stress conditions after planting. The aim of this study is to compare seedling response of Musa cv. Williams treated with biostimulants and commercial de-stressing agents. Thirty days after inoculation, pseudostem diameter (cm), fresh plant mass (g), fresh root mass (g), root number, soil-plant analysis development (SPAD) index, edaphic ionic content and foliar content (pH, CE, NO3-, K+, Na+ and Ca2+) were evaluated. Preliminary results indicated, that StresSal® and (StresSal® + Equilibrium®) showed signif icantly greater pseudostem diameter. The highest radical fresh mass corresponded to (Inicium® + StresSal®). Root number was not signif icantly different. The SPAD index was elevated when StresSal® was applied alone or with Equilibrium®. The treatment (Inicium®+StresSal®) contributed to higher soil acidity. Conductivity (CE), K+ and Na+ were higher when Inicium® + Pro- Fulvic® were applied. As NO3- levels increased with Inicium®, Ca2+ ions decreased signif icantly in soil with Inicium® + StresSal®. Regarding foliar content, the highest pH corresponded to Inicium®, conductivity (CE) was higher with StresSal® and Inicium® + StresSal®, without difference with the control. An increase in NO3- was found with Inicium® + StresSal®. While Na+ and Ca2+ were signif icantly higher with Inicium® + Pro-Fulvic®.

The bell peppers (Capsicum annuum L.) cultivars grown in Colombia come from countries with temperate zones, which limits their production in climate and agroecological conditions of the country, since they do not reach their adaptability and potential yield, due to factors that af fect gene expression. In Colombia, 95% of bell peppers are sowed in open f ield. However, farmers seek to improve their yields by growing them under protected condition with plastic cover and natural ventilation. Therefore the objective of this study is to evaluate fruit yield and pest and disease incidence of four bell pepper cultivars (BG2, Cuadrado rojo, Cacique and Nathalie) grown under three types of environments: open f ield in 2014 and protected in two cycles (2013 and 2014). The trials were conducted under multilocation trials with a randomized complete block design (RCBD) at La Selva Research Center (AGROSAVIA), located in Rionegro-Antioquia (Colombia). The following variables were measured: fruit yield, number, length and diameter per category. Incidence of pests and diseases were also recorded. No signif icant statistical dif ferences were found among yields obtained under the dif ferent environments. The genetic ef fect of cultivars was more determinant than the ef fect of environments on yield variables. In protected environments, Cacique and Nathalie cultivars had the highest yield, while BG2 and Cuadrado rojo had the highest rejected fruit yield. The incidence of the main pests and diseases was irregular, which was higher under protected conditions and had no direct connection with the cultivars.

The article shows a research project which discusses the graduation program within mental health field, specially the nursing course. We admit that it is necessary to improve studies concerning to new pedagogical tendencies, aiming to overcome the traditional education model which privileges the knowledge transference as a purpose itself, the little flexibility of curriculums and the professors and students stiff performance, factors that prevent the critical-reflexive development of professionals. Before this problem, we searched on competencies pedagogy, a theoretical support for necessary changes in the sense to improve and update the education-learning process. We suggest a dialogue between practice and assistance education on psychiatric and mental health nursing, on which teachers and nurses may indicate a way to identify and build necessary capacities to enable nurses to act with efficacy in real situations present in mental health.