Methods for short-term control of Imperata grass in Peruvian Amazon

The traditional control of Imperata brasiliensis grasslands used by farmers in the Peruvian Amazon is to burn the grass. The objective of this study was to compare different methods of short-term control. Biological, mechanical, chemical and traditional methods of control were compared. Herbicide spraying and manual weeding have shown to be very effective in reducing above- and below-ground biomass growth in the first 45 days after slashing the grass, with effects persisting in the longer term, but both are expensive methods. Shading seems to be less effective in the short-term, whereas it influences the Imperata growth in the longer term. After one year shading, glyphosate application and weeding significantly reduced aboveground biomass by 94, 67 and 53%; and belowground biomass by 76, 65 and 58%, respectively, compared to control. We also found a significant decrease of Imperata rhizomes in soil during time under shading. Burning has proved to have no significant effect on Imperata growth. The use of shade trees in a kind of agroforestry system could be a suitable method for small farmers to control Imperata grasslands.

Can commercialization of NTFPs alleviate poverty? A case study of Ricinodendron heudelotii (Baill.) Pierre ex Pax. kernel marketing in Cameroon

Ricinodendron heudelotii (Baill.) Pierre ex Pax. kernel (njansang) commercialization has been promoted by the World Agroforestry Centre (ICRAF) in project villages in Cameroon with the aim to alleviate poverty for small-scale farmers. We evaluated to what extent development interventions improved the financial situation of households by comparing project and control households. The financial importance of njansang to household livelihoods between 2005 and 2010 was investigated through semi-structured questionnaires with retrospective questions, focus group discussions, interviews and wealth-ranking exercises. The importance of njansang increased strongly in the entire study region and the increase was significantly larger in project households. Moreover, absolute numbers of income from njansang commercialization as well as relative importance of njansang in total cash income, increased significantly more in project households (p < 0.05). Although the lower wealth class households could increase their income through njansang trade, the upper wealth class households benefited more from the projects' interventions. Group sales as conducted in project villages did not lead to significantly higher prices and should be reconsidered. Hence, promotion of njansang had a positive effect on total cash income and can still be improved. The corporative actors for njansang commercialization are encouraged to adapt their strategies to ensure that also the lower wealth class households benefit from the conducted project interventions. In this respect, frequent project monitoring and impact analysis are important tools to accomplish this adaptation.

Moments of classical orthogonal polynomials

The aim of this work is to find simple formulas for the moments mu_n for all families of classical orthogonal polynomials listed in the book by Koekoek, Lesky and Swarttouw. The generating functions or exponential generating functions for those moments are given.

Utilisation of Giant African snail (Achatina fulica) meal as protein source by laying hens

A 12-week experiment was carried out to investigate the effects of substituting Giant African snail meal for fish meal in laying hens diet. Four diets were formulated to contain snail meal as replacement for fish meal at 0 (control), 33, 67 and 100%. A total of 120 Shaver Brown pullets aged 18 weeks were allocated to the dietary treatments in a randomised design. Each treatment consisted of three replicates and ten birds per replicate. Feed intake increased only for the 33% treatment as compared to the 67% replacement diet but did not differ from the other treatments. There were no significant treatment effects on egg performance parameters observed (egg production, egg weight, total egg mass, feed conversion ratio and percent shell). The overall feed cost of egg production reduced on the snail meal-based diets. The organoleptic evaluation of boiled eggs revealed no difference between the treatments. Based on these results it was concluded that total replacement of fish meal with cooked snail meat meal does not compromise laying performance or egg quality. The substitution is beneficial in terms of production cost reduction and the reduction of snails will have a beneficial impact especially where these snails are a serious agricultural pest. The manual collection and processing of snails can also become a source of rural income.

From Subsistence Agriculture to Commercial Enterprise: Community management of green technologies for resilient food production

The aim of this paper is to emphasize the capacity and resilience of rural communities in regard to sustainable food security by adopting innovative approaches to irrigation. The shift from subsistence to commercial agriculture is promoted as a means to sustainable development. An analysis of the efficacy of irrigation schemes in Zimbabwe suggests that, in terms of providing sustainable agricultural production, they have neither been cost-effective nor have they provided long-term food security to their beneficiaries. This is certainly true of Shashe Scheme and most others in Beitbridge District. The Shashe Irrigation Scheme project represents a bold attempt at developing a fresh approach to the management of communal land irrigation schemes through a Private Public Community Partnership. The model illustrated represents a paradigm shift from subsistence agriculture to a system based on new technologies, market linkages and community ownership that build resilience and lead to sustainable food security and economic prosperity.

Perceiving Illumination Inconsistencies in Scenes

The human visual system is adept at detecting and encoding statistical regularities in its spatio-temporal environment. Here we report an unexpected failure of this ability in the context of perceiving inconsistencies in illumination distributions across a scene. Contrary to predictions from previous studies [Enns and Rensink, 1990; Sun and Perona, 1996a, 1996b, 1997], we find that the visual system displays a remarkable lack of sensitivity to illumination inconsistencies, both in experimental stimuli and in images of real scenes. Our results allow us to draw inferences regarding how the visual system encodes illumination distributions across scenes. Specifically, they suggest that the visual system does not verify the global consistency of locally derived estimates of illumination direction.

Materiales para el desarrollo de la comunicación y el apoyo al alumnado con necesidades educativas especiales : recopilación de artículos de Martha E. Snell y colaboradores.

Este manual, traducido por asesores técnicos de la Dirección General de Participación y Solidaridad en la Educación, describe el proceso para evaluar la comunicación no simbólica de las personas con discapacidad severa. El material que se ofrece en esta guía resulta muy útil para su trabajo con personas que se comunican a través de medios no simbólicos.

Constitución e Integración

Este libro recoge las actas del coloquio constitución e integración organizado en París los días 3 y 4 de junio de 2005, por la Asociation Adrés Bello de juistes frano-lationaméricains. El tema central aborda la tendencia integracionista ampliamente desarrollada en la segunda mitad del siglo XX, la cual ha influido las constituciones modernas en la previsión de disposiciones que permiten la atribución de ciertas competencias, anteriormente consideradas como exclusivas de la soberanía del Estado, a órganos supranacionales. Es así como, inicialmente en materia económica y luego en otras materias, la integración ha generado la creación de entes supranacionales encargados no sólo de establecer las políticas necesarias para que la integración sea viable, sino también para establecer las normas necesarias para que dicha política sea una realidad. Esta situación presenta un fuerte impacto sobre la estructura jurídica tradicional del Estado. En dicho caso la Constitución deja de ser un marco jurídico rígido para convertirse en un elemento flexible; la Unión Europea es un ejemplo clave de este fenómeno. Múltiples interrogantes surgen entonces con respecto de la jerarquía de normas y de la supremacía de la Constitución frente a los tratados de integración.

Experiencias de incorporación de aplicaciones semánticas a la educación.

Resumen tomado del autor

Análisis de la actuación de Estados Unidos y la ONU en Somalia en la creación de un entorno seguro para asistencia humanitaria. (1992-1995)

La creación de un entorno seguro para otorgar la ayuda humanitaria a la población somalí, fue un desafío de proporciones internacionales, en el que la máxima potencia del mundo, Estados y organizaciones, vieron fracasar todos los proyectos tanto en forma de ayudas como en estrategias y operaciones. Las razones de este fracaso de carácter mundial, debido a que representó una amenaza para la paz y la seguridad internacional, todavía se pueden evidenciar en Somalia; este país continúa siendo uno de los más pobres de mundo, no cuenta con gobierno efectivo y no se logró hacer cesar las continuas violaciones de derechos humanos y derecho internacional humanitario en contra de los civiles. La importancia de este caso de estudio radica en el nuevo contexto en el cual se desenvuelve la actuación de la ONU y Estados Unidos en Somalia, en un escenario donde se hace crucial el respeto por los derechos humanos, y se puede evidenciar cómo en esta medida se da lugar a efectuar una intervención humanitaria que antes de la guerra fría hubiera sido inadmisible, partiendo de la importancia del concepto de soberanía estatal. El período fundamental en el cual el problema somalí asume magnitud internacional fue en 1991 con la caída de la dictadura militar y el inicio de un período de carestía que volvió la ya inestable situación del país en un escenario violento, caracterizado por una desastrosa situación de crisis humanitaria, culminado en la batalla de Mogadiscio, que obligó a las interrupciones de las intervenciones internacionales y al fracaso completo de estas últimas en 1995. La actuación de la ONU y de Estados Unidos en el intento de crear un entorno seguro para asistencia humanitaria en Somalia en un período de cuatro años, llevó a la creación de la UNOSOM I, UNITAF y UNOSOM II; durante este tiempo la ONU autorizó el uso de la fuerza si era necesario para asegurar la entrega de la ayuda humanitaria, por lo que los cascos azules hicieron una fuerte presencia. Finalizando 1995 los intentos fracasaron y la ONU y los Estados Unidos decidieron retirarse de Somalia indefinidamente. El siguiente trabajo se enfoca en cuatro años de un adverso desequilibrio en el territorio somalí, dando cuenta del papel que desempeñaron Estados Unidos y la ONU en el intento de crear un entorno seguro parar asistencia humanitaria, dada la precaria situación que atravesaban los civiles envueltos en la guerra civil que hasta hoy no ha culminado, y en un discurso moral que caracterizó a la comunidad internacional acerca la responsabilidad de proteger. A la luz de la carta de Naciones Unidas y de los hechos que transcurrieron antes y durante la actuación de la ONU y Estados Unidos, este caso de estudio pretende exponer los rasgos que definieron la intervención en el intento de crear un entorno seguro para asistencia humanitaria y que finalmente fracasaron.

The University and How We Interact With It

This is a presentation I put together to get students thinking about their digital university experience. The resulting discussions will be used to inform a survey sent out to all students to find out what parts of the digital university experience are important to them.

Open Source Licenses in Academia

A Seminar about the advantages of using open source licenses as a complimentary strategy to the academic publish process.