Prospects of doubling global wheat yields

While an adequate supply of food can be achieved at present for the current global population, sustaining this into the future will be difficult in the face of a steadily increasing population, increased wealth and a diminishing availability of fertile land and water for agriculture. This problem will be compounded by the new uses of agricultural products, for example, as biofuels. Wheat alone provides ≥20% of the calories and the protein for the world's population, and the value and need to increase the production is recognized widely. Currently, the world average wheat yield is around 3 t/ha but there is considerable variation between countries, with region-specific factors limiting yield, each requiring individual solutions. Delivering increased yields in any situation is a complex challenge that is unlikely to be solved by single approaches and a multidisciplinary integrated approach to crop improvement is required. There are three specific major challenges: increasing yield potential, protecting yield potential, and increasing resource use efficiency to ensure sustainability. Since the green revolution, yields at the farm gate have stagnated in many countries, or are increasing at less than half the rate required to meet the projected demand. In some countries, large gains can still be achieved by improvements in agronomy, but in many others the yield gains will only be achieved by further genetic improvement. In this overview, the problems and potential solutions for increased wheat yields are discussed, in the context of specific geographic regions, with a particular emphasis on China. The importance and the prospects for improvement of individual traits are presented. It is concluded that there are opportunities for yield increase but a major challenge will be avoiding a simultaneous increase in resource requirements.

Estudio de gestión de la finca La Esperanza, municipio de Pueblo Nuevo, Nicaragua

El presente proyecto tiene como finalidad el análisis de la Finca la Esperanza, en la localidad de Pueblo Nuevo, en la República de Nicaragua. En dicho análisis se estudian parámetros edáficos, calidad de agua y económicos, con el objetivo de poder plantear una propuesta de mejora en los rendimientos de la finca tanto a nivel económico como ambiental. La iniciativa de realizar este estudio surge de las necesidades del propio agricultor, que plantea el desarrollo rural sobre la base de actividades respetuosas con el medio. Las estrategias a los problemas sociales originados por la producción agraria industrial, como el éxodo rural, la pérdida de la agricultura convencional, la nueva función de los espacios agrarios de la sociedad, etc., se formalizaron en el denominado Desarrollo Sostenible. A nivel de finca cualquier concepción de sustentabilidad necesita que el agrosistema sea considerado como un ecosistema, en el que la investigación y la producción busquen no solamente altos rendimientos sino la optimización del sistema como un todo. Tal propósito requiere armonizar una viabilidad económica con otras variables, como estabilidad ecológica y equidad social. Para ello, los principios básicos de un sistema sostenible son: la conservación de los recursos renovables, la adaptación del cultivo al ambiente y el mantenimiento de un moderado pero sostenible nivel de producción. Como resultado de los análisis y observaciones hechas a lo largo de la estancia en la finca, se propone un plan de actuación de 10 años de duración en los cuales se procura alcanzar no únicamente unas cuotas máximas de rendimiento sino también la supervivencia de los recursos, base de la familia Videa Vanegas, propietarios.

Implementation of IPM programs on European greenhouse tomato production areas: Tools and constraints

Whiteflies and whitefly-transmitted viruses are some of the major constraints on European tomato production. The main objectives of this study were to: identify where and why whiteflies are a major limitation on tomato crops; collect information about whiteflies and associated viruses; determine the available management tools; and identify key knowledge gaps and research priorities. This study was conducted within the framework of ENDURE (European Network for Durable Exploitation of Crop Protection Strategies). Two whitefly species are the main pests of tomato in Europe: Bemisia tabaci and Trialeurodes vaporariorum. Trialeurodes vaporariorum is widespread to all areas where greenhouse industry is present, and B. tabaci has invaded, since the early 1990’s, all the subtropical and tropical areas. Biotypes B and Q of B. tabaci are widespread and especially problematic. Other key tomato pests are Aculops lycopersici, Helicoverpa armigera, Frankliniella occidentalis, and leaf miners. Tomato crops are particularly susceptible to viruses causingTomato yellow leaf curl disease (TYLCD). High incidences of this disease are associated to high pressure of its vector, B. tabaci. The ranked importance of B. tabaci established in this study correlates with the levels of insecticide use, showing B. tabaci as one of the principal drivers behind chemical control. Confirmed cases of resistance to almost all insecticides have been reported. Integrated Pest Management based on biological control (IPM-BC) is applied in all the surveyed regions and identified as the strategy using fewer insecticides. Other IPM components include greenhouse netting and TYLCD-tolerant tomato cultivars. Sampling techniques differ between regions, where decisions are generally based upon whitefly densities and do not relate to control strategies or growing cycles. For population monitoring and control, whitefly species are always identified. In Europe IPM-BC is the recommended strategy for a sustainable tomato production. The IPM-BC approach is mainly based on inoculative releases of the parasitoids Eretmocerus mundus and Encarsia formosa and/or the polyphagous predators Macrolophus caliginosus and Nesidiocoris tenuis. However, some limitations for a wider implementation have been identified: lack of biological solutions for some pests, costs of beneficials, low farmer confidence, costs of technical advice, and low pest injury thresholds. Research priorities to promote and improve IPM-BC are proposed on the following domains: (i) emergence and invasion of new whitefly-transmitted viruses; (ii) relevance of B. tabaci biotypes regarding insecticide resistance; (iii) biochemistry and genetics of plant resistance; (iv) economic thresholds and sampling techniques of whiteflies for decision making; and (v) conservation and management of native whitefly natural enemies and improvement of biological control of other tomato pests.

Tritordeum, wheat and triticale yield components under multi-local mediterranean drought conditions

The species x location interaction was of great importance in explaining the behaviour of genetic material. The study presented here shows, for the first time, the performance, under field conditions of the new tritordeum species, compared to wheat and triticale in a wide range of Mediterranean countries (Spain, Lebanon and Tunisia). The results obtained revealed that despite the diversity of environmental conditions, the main differences in yield were due to genotypes, especially to differences between species. The multi-local study with different growth conditions revealed important information about the water availability effect on yield. In the lowest yielding environments (Tunisia rainfed), Tritordeum and triticale yields were equivalent. However under better growth conditions (Spain), tritordeum yield was shown to be lower than wheat and triticale. Interestingly, when water limitation was extended during the pre-anthesis period, differences in tritordeum versus wheat-triticale yield rate were larger than when water stress occurred during anthesis. These variations were explained by the fact that kernel weight has been found as the limiting factor for yield determination in tritordeum, and a delay in the anthesis date may have been the cause for the low kernel weight and low yield under Mediterranean drought conditions. Such differences in yield between tritordeum and wheat or triticale could be explained by the fact that tritordeum is a relatively new species and far fewer resources have been devoted to its improvement when compared to wheat and triticale. Our results suggest that breeding efforts should be directed to an earlier anthesis date and a longer grain filling period. tritordeum proved to have possibilities to be grown under drought environments as a new crop, since its performance was quite close to wheat and triticale. Besides, it has qualitative added values that may improve farmers' income per unit land.

Information systems for water resources management improvement in developing countries

Water resources management, as also water service provision projects in developing countries have difficulties to take adequate decisions due to scarce reliable information, and a lack of proper information managing. Some appropriate tools need to be developed in order to improve decision making to improve water management and access of the poorest, through the design of Decision Support Systems (DSS). On the one side, a DSS for developing co-operation projects on water access improvement has been developed. Such a tool has specific context constrains (structure of the system, software requirements) and needs (Logical Framework Approach monitoring, organizational-learning, accountability and evaluation) that shall be considered for its design. Key aspects for its successful implementation have appeared to be a participatory design of the system and support of the managerial positions at the inception phase. A case study in Tanzania was conducted, together with the Spanish NGO ONGAWA – Ingeniería para el Desarrollo. On the other side, DSS are required also to improve decision making on water management resources in order to achieve a sustainable development that not only improves the living conditions of the population in developing countries, but that also does not hinder opportunities of the poorest on those context. A DSS made to fulfil these requirements shall be using information from water resources modelling, as also on the environment and the social context. Through the research, a case study has been conducted in the Central Rift Valley of Ethiopia, an endhorreic basin 160 km south of Addis Ababa. There, water has been modelled using ArcSWAT, a physically based model which can assess the impact of land management practices on large complex watersheds with varying soils, land use and management conditions over long periods of time. Moreover, governance on water and environment as also the socioeconomic context have been studied.

Friction Stir Processing : a new microstructure improvement technique

In the present work, microstructure improvement using FSP (Friction Stir Processing) is studied. In the first part of the work, the microstructure improvement of as-cast A356 is demonstrated. Some tensile tests were applied to check the increase in ductility. However, the expected results couldn’t be achieved. In the second part, the microstructure improvement of a fusion weld in 1050 aluminium alloy is presented. Hardness tests were carried out to prove the mechanical propertyimprovements. In the third and last part, the microstructure improvement of 1050 aluminium alloy is achieved. A discussion of the mechanical property improvements induced by FSP is made. The influence of tool traverse speed on microstructure and mechanical properties is also discussed. Hardness tests and recrystallization theory enabled us to find out such influence

Improvement of the quality factor of RF integrated inductors by layout optimization

A systematic method to improve the quality (Q) factor of RF integrated inductors is presented in this paper. The proposed method is based on the layout optimization to minimize the series resistance of the inductor coil, taking into account both ohmic losses, due to conduction currents, and magnetically induced losses, due to eddy currents. The technique is particularly useful when applied to inductors in which the fabrication process includes integration substrate removal. However, it is also applicable to inductors on low-loss substrates. The method optimizes the width of the metal strip for each turn of the inductor coil, leading to a variable strip-width layout. The optimization procedure has been successfully applied to the design of square spiral inductors in a silicon-based multichip-module technology, complemented with silicon micromachining postprocessing. The obtained experimental results corroborate the validity of the proposed method. A Q factor of about 17 have been obtained for a 35-nH inductor at 1.5 GHz, with Q values higher than 40 predicted for a 20-nH inductor working at 3.5 GHz. The latter is up to a 60% better than the best results for a single strip-width inductor working at the same frequency.

Renormalization-group improvement of the spectrum of hydrogenlike atoms with massless fermions

We obtain the next-to-next-to-leading-logarithmic renormalization-group improvement of the spectrum of hydrogenlike atoms with massless fermions by using potential NRQED. These results can also be applied to the computation of the muonic hydrogen spectrum where we are able to reproduce some known double logarithms at O(m¿s6). We compare with other formalisms dealing with logarithmic resummation available in the literature.

Time-related improvement of survival in resectable gastric cancer: the role of Japanese-style gastrectomy with D2 lymphadenectomy and adjuvant chemotherapy

Background: We investigated the change of prognosis in resected gastric cancer (RGC) patients and the role of radical surgery and adjuvant chemotherapy. Methods: We retrospectively analyze the outcome of 426 consecutive patients from 1975 to 2002, divided into 2 time-periods (TP) cohort: Before 1990 (TP1, n = 207) and 1990 or after (TP2; n= 219). Partial gastrectomy and D1-lymphadenetomy was predominant in TP1 and total gastrectomy with D2-lymphadenectomy it was in TP2. Adjuvant chemotherapy consisted of mitomycin C (MMC), 10¿20 mg/m2 iv 4 courses or MMC plus Tegafur 500 mg/m2 for 6 months. Results: Positive nodes were similar in TP2/TP1 patients with 56%/59% respectively. Total gastrectomy was done in 56%/45% of TP2/TP1 respectively. Two-drug adjuvant chemotherapy was administered in 65%/18% of TP2/TP1 respectively. Survival at 5 years was 66% for TP2 versus 42%for TP1 patients (p < 0.0001). Survival by stages II, IIIA y IIIB for TP2 versus TP1 patients was 70 vs. 51% (p = 0.0132); 57 vs. 22% (p = 0.0008) y 30 vs. 15% (p = 0.2315) respectively. Multivariate analysis showed that age, stage of disease and period of treatment were independent variables. Conclusion: The global prognosis and that of some stages have improved in recent years with case RGC patients treated with surgery and adjuvant chemotherapy.

La Participación de los estudiantes en la universidad: dificultades percibidas y propuestas de mejora = Student participation in the university: perceived problems and proposals for improvement

Este artículo se centra en el análisis de la participación de los estudiantes en el gobierno de la universidad y muestra específicamente las principales dificultades que hay para ella y las propuestas que pueden facilitar la implicación de los estudiantes en el funcionamiento de las universidades. A partir de una investigación desarrollada durante los cursos 2007-08 y 2008-09, en la que se utilizaron cuestionarios y grupos de discusión con estudiantes y entrevistas dirigidas al profesorado, se obtiene información sobre los principales obstáculos para la participación estudiantil. El estudio realizado muestra que, de acuerdo con la tónica general reflejada en otras investigaciones sobre esta misma temática en nuestro contexto, la participación de los estudiantes en los distintos estamentos universitarios es escasa. Ahora bien, la metodología seguida en esta investigación permite contrastar las opiniones de los estudiantes con las percepciones del profesorado y obtener así matices significativos que muestran las principales direcciones que hay que tomar para facilitar un cambio de orientación en el asunto. Los cambios que debemos emprender están relacionados no solo con la mejora de los mecanismos de información acerca de los canales de participación, sino también con el replanteamiento de los procesos participativos por parte de la universidad, así como del papel del profesorado y, específicamente, de los coordinadores de los órganos de gestión más próximos a los estudiantes. En las conclusiones del documento se presentan las propuestas de mejora dirigidas a potenciar la implicación de los estudiantes en el funcionamiento universitario. Entre ellas se apuntan las siguientes: mejorar la información y los canales de comunicación con los estudiantes, mejorar los procesos electorales, ofrecer formación a los estudiantes para la participación y formación al profesorado acerca de las metodologías, recursos e instrumentos que pueden repercutir en la motivación de los estudiantes

Improvement of a fully distributed decision making protocol for CRN

Abstract¿La deteción del espectro libre para las comunicaciones inalámbricas en un momento puntual es una tarea compleja cuyo desarrollo se simplica al realizarse de forma distribuida por una red de radio cognitiva. Sin embargo existes dificultades y vulnerabilidades de seguridad que han de ser tenidas en cuenta y solventadas a la hora de autenticar y validar los nodos de la red. Este artículo presenta una propuesta de mejora del protocolo fully distributed decision making protocol for CRN con el fin de llevar a cabo esta tarea de detección del espectro de una manera eficiente y segura.

Application of the Mutual Information Minimization to speaker recognition / identification improvement

In this paper we propose the inversion of nonlinear distortions in order to improve the recognition rates of a speaker recognizer system. We study the effect of saturations on the test signals, trying to take into account real situations where the training material has been recorded in a controlled situation but the testing signals present some mismatch with the input signal level (saturations). The experimental results for speaker recognition shows that a combination of several strategies can improve the recognition rates with saturated test sentences from 80% to 89.39%, while the results with clean speech (without saturation) is 87.76% for one microphone, and for speaker identification can reduce the minimum detection cost function with saturated test sentences from 6.42% to 4.15%, while the results with clean speech (without saturation) is 5.74% for one microphone and 7.02% for the other one.