998 resultados para Western pine beetle.


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Research on soil fertility management in sub-Saharan Africa was criticized lately for largely ignoring farmers’ management strategies and the underlying principles. To fill this gap of knowledge, detailed interviews were conducted with 108 farm households about their rationale in managing the soil fertility of 307 individual fields in the agro-pastoral village territory of Chikal in western Niger. To amplify the farmers’ information on manuring and corralling practices, repeated measurements of applied amounts of manure were carried out within six 1-km^2 monitoring areas from February to October 1998. The interviews revealed that only 2% of the fields were completely fallowed for a period of 1–15 years, but 40% of the fields were at least partially fallowed. Mulching of crop residues was mainly practiced to fight wind erosion but was restricted to 36% of the surveyed fields given the alternative use of straw as livestock feed. Manure application and livestock corralling, as most effective tools to enhance soil fertility, were targeted to less than 30% of the surveyed fields. The application of complete fallow and manuring and corralling practices were strongly related to the households’ endowment with resources, especially with land and livestock. Within particular fields, measures were mainly applied to spots of poor soil fertility, while the restoration of the productivity of hard pans was of secondary importance. Given the limited spatial coverage of indigenous soil fertility measures and their strong dependence on farmers’ wealth, supplementary strategies to restrict the decline of soil fertility in the drought prone areas of Niger with their heavily weathered soils are needed.

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Maize production in smallholder farming systems in Kenya is largely limited by low soil fertility. As mineral fertilizer is expensive, green manuring using leguminous cover crops could be an alternative strategy for farmers to enhance farm productivity. However due to variability in soil type and crop management, the effects of green manure are likely to differ with farms. The objectives of this study were to evaluate Mucuna pruriens and Arachis pintoi on (i) biomass and nitrogen fixation (^15N natural abundance), (ii) soil carbon and nitrogen stocks and (iii) their effects on maize yields over two cropping seasons in Kakamega, Western Kenya. Mucuna at 6 weeks accumulated 1–1.3 Mg ha^{-1} of dry matter and 33–56 kg ha^{-1} nitrogen of which 70% was nitrogen derived from the atmosphere (Ndfa). Arachis after 12 months accumulated 2–2.7 Mg ha^{-1} of dry matter and 51–74 kg N ha^{-1} of which 52-63 % was from Ndfa. Soil carbon and nitrogen stocks at 0–15 cm depth were enhanced by 2-4 Mg C ha^{-1} and 0.3–1.0 Mg N ha^{-1} under Mucuna and Arachis fallow, irrespective of soil type. Maize yield increased by 0.5-2 Mg ha^{-1} in Mucuna and 0.5–3 Mg ha^{-1} in Arachis and the response was stronger on Nitisol than on Acrisol or Ferralsol. We concluded that leguminous cover crops seem promising in enhancing soil fertility and maize yields in Kenya, provided soil conditions and rainfall are suitable.

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The potential benefit of indigenous chicken (Gallus domesticus) production is still under-exploited in Kenya despite the efforts by different stakeholders to mainstream this production system as a pathway to rural development. The production system is often characterized by low input-low output productivity and low commercialization of the enterprise. This study which dwells on the current management practices and challenges faced by smallholder indigenous chicken farmers was conducted to gain insights into the underlying causes of production constraints. In Western Kenya women (76%) dominate the indigenous chicken production system. The flock composition consists mainly of chicks, hens and pullets (80%) which reflects their retention for production purposes. Less than half of the farmers access institutional support services such as extension, training, credit and veterinary services. In addition, indigenous chicken is largely reared in a low input-low output free-range system with only few farmers (24.2%) adopting management interventions as disseminated by extension service. To improve production and attain increased productivity, policy should focus on repackaging extension messages that considers farmers economic situations and strengthens collective action initiatives. Accessing joint input purchase and collective marketing of chicken products may further assist the farmers to increase profit margins.

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In the Democratic Republic of the Congo (DRC), pigs are raised almost exclusively by smallholders either in periurban areas of major cities such as Kinshasa or in rural villages. Unfortunately, little information is available regarding pig production in the Western part of the DRC, wherefore a survey was carried out to characterize and compare 319 pig production systems in their management and feeding strategies, along a periurban - rural gradient inWestern provinces of the DRC. Pig breeding was the main source of income (43%) and half of respondents were active in mixed pig and crop production, mainly vegetable garden. Depending on the location, smallholders owned on average 18 pigs, including four sows. Piglet mortality rate varied from 9.5 to 21.8% while average weaned age ranged between 2.2 and 2.8 months. The major causes of mortality reported by the farmers were African swine fever 98 %, swine erysipelas (60 %), erysipelas trypanosomiasis (31 %), swine worm infection (17 %), and diarrhoea (12 %). The majority of the pigs were reared in pens without free roaming and fed essentially with locally available by-products and forage plants whose nature varied according with the location of the farm. The pig production systems depended on the local environment; particularly in terms of workforces, herd structure and characteristics, production parameters, pig building materials, selling price and in feed resources. It can be concluded that an improvement of Congolese pig production systems should consider (1) a reduction of inbreeding, (2) an improvement in biosafety to reduce the incidence of African swine fever and the spread of other diseases, and (3) an improvement in feeding practices.

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Maize production in western Kenya is often limited by deficiencies of nitrogen and phosphorus. We assessed the effectiveness of Tithonia diversifolia green manure (tithonia), farmyard manure (FYM) and urea as sources of nitrogen (N) for maize when inorganic phosphorus (P) fertiliser was either broadcast (BR) or spot-placed in the planting hole (SP) for two consecutive seasons; October to December of 1998 and April to August of 1999 at two sites; Nyabeda and Khwisero in western Kenya. A randomised complete block design with four replications was used. Maize yields were higher at Nyabeda and responded to P application better than at Khwisero. At the same N rate, tithonia and FYM were as effective as urea in increasing maize yields at both sites. There were no significant differences in maize yields when phosphate fertiliser was either BR or SP regardless of the N source used in the first season. However, in the second season, the residual yields for the BR treatments were consistently higher than those of the SP. Our results suggest that tithonia and FYM can substitute for urea as N sources and that fertiliser P should be broadcast and incorporated together with the organic materials at the time of planting to save on labour costs.

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Das Mahafaly Plateau im südwestlichen Madagaskar ist gekennzeichnet durch raue klimatische Bedingungen, vor allem regelmäßige Dürren und Trockenperioden, geringe Infrastruktur, steigende Unsicherheit, hohe Analphabetenrate und regelmäßige Zerstörung der Ernte durch Heuschreckenplagen. Da 97% der Bevölkerung von der Landwirtschaft abhängen, ist eine Steigerung der Produktivität von Anbausystemen die Grundlage für eine Verbesserung der Lebensbedingungen und Ernährungssicherheit in der Mahafaly Region. Da wenig über die Produktivität von traditionellen extensiven und neu eingeführten Anbaumethoden in diesem Gebiet bekannt ist, waren die Zielsetzungen der vorliegenden Arbeit, die limitierenden Faktoren und vielversprechende alternative Anbaumethoden zu identifizieren und diese unter Feldbedingungen zu testen. Wir untersuchten die Auswirkungen von lokalem Viehmist und Holzkohle auf die Erträge von Maniok, der Hauptanbaufrucht der Region, sowie die Beiträge von weiteren Faktoren, die im Untersuchungsgebiet ertragslimitierend sind. Darüber hinaus wurde in der Küstenregion das Potenzial für bewässerten Gemüseanbau mit Mist und Holzkohle untersucht, um zu einer Diversifizierung von Einkommen und Ernährung beizutragen. Ein weiterer Schwerpunkt dieser Arbeit war die Schätzung von Taubildung und deren Beitrag in der Jahreswasserbilanz durch Testen eines neu entworfenen Taumessgerätes. Maniok wurde über drei Jahre und in drei Versuchsfeldern in zwei Dörfern auf dem Plateau angebaut, mit applizierten Zeburindermistraten von 5 und 10 t ha-1, Holzkohleraten von 0,5 und 2 t ha-1 und Maniokpflanzdichten von 4500 Pflanzen ha-1. Maniokknollenerträge auf Kontrollflächen erreichten 1 bis 1,8 t Trockenmasse (TM) ha-1. Mist führte zu einer Knollenertragssteigerung um 30 - 40% nach drei Jahren in einem kontinuierlich bewirtschafteten Feld mit geringer Bodenfruchtbarkeit, hatte aber keinen Effekt auf den anderen Versuchsfeldern. Holzkohle hatte keinen Einfluss auf Erträge über den gesamten Testzeitraum, während die Infektion mit Cassava-Mosaikvirus zu Ertragseinbußen um bis zu 30% führte. Pflanzenbestände wurden felder-und jahresübergreifend um 4-54% des vollen Bestandes reduziert, was vermutlich auf das Auftreten von Trockenperioden und geringe Vitalität von Pflanzmaterial zurückzuführen ist. Karotten (Daucus carota L. var. Nantaise) und Zwiebeln (Allium cepa L. var. Red Créole) wurden über zwei Trockenzeiten mit lokal erhältlichem Saatgut angebaut. Wir testeten die Auswirkungen von lokalem Rindermist mit einer Rate von 40 t ha-1, Holzkohle mit einer Rate von 10 t ha-1, sowie Beschattung auf die Gemüseernteerträge. Lokale Bewässerungswasser hatte einen Salzgehalt von 7,65 mS cm-1. Karotten- und Zwiebelerträge über Behandlungen und Jahre erreichten 0,24 bis 2,56 t TM ha-1 beziehungsweise 0,30 bis 4,07 DM t ha-1. Mist und Holzkohle hatten keinen Einfluss auf die Erträge beider Kulturen. Beschattung verringerte Karottenerträge um 33% im ersten Jahr, während sich die Erträge im zweiten Jahr um 65% erhöhten. Zwiebelerträge wurden unter Beschattung um 148% und 208% im ersten und zweiten Jahr erhöht. Salines Bewässerungswasser sowie Qualität des lokal verfügbaren Saatgutes reduzierten die Keimungsraten deutlich. Taubildung im Küstendorf Efoetsy betrug 58,4 mm und repräsentierte damit 19% der Niederschlagsmenge innerhalb des gesamten Beobachtungszeitraum von 18 Monaten. Dies weist darauf hin, dass Tau in der Tat einen wichtigen Beitrag zur jährlichen Wasserbilanz darstellt. Tageshöchstwerte erreichten 0,48 mm. Die getestete Tauwaage-Vorrichtung war in der Lage, die nächtliche Taubildung auf der metallischen Kondensationsplatte zuverlässig zu bestimmen. Im abschließenden Kapitel werden die limitierenden Faktoren für eine nachhaltige Intensivierung der Landwirtschaft in der Untersuchungsregion diskutiert.

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Short summary: This study was undertaken to assess the diversity of plant resources utilized by the local population in south-western Madagascar, the social, ecological and biophysical conditions that drive their uses and availability, and possible alternative strategies for their sustainable use in the region. The study region, ‘Mahafaly region’, located in south-western Madagascar, is one of the country’s most economically, educationally and climatically disadvantaged regions. With an arid steppe climate, the agricultural production is limited by low water availability and a low level of soil nutrients and soil organic carbon. The region comprises the recently extended Tsimanampetsotsa National Park, with numerous sacred and communities forests, which are threatened by slash and burn agriculture and overexploitation of forests resources. The present study analyzed the availability of wild yams and medicinal plants, and their importance for the livelihood of the local population in this region. An ethnobotanical survey was conducted recording the diversity, local knowledge and use of wild yams and medicinal plants utilized by the local communities in five villages in the Mahafaly region. 250 households were randomly selected followed by semi-structured interviews on the socio-economic characteristics of the households. Data allowed us to characterize sociocultural and socioeconomic factors that determine the local use of wild yams and medicinal plants, and to identify their role in the livelihoods of local people. Species-environment relationships and the current spatial distribution of the wild yams were investigated and predicted using ordination methods and a niche based habitat modelling approach. Species response curves along edaphic gradients allowed us to understand the species requirements on habitat conditions. We thus investigated various alternative methods to enhance the wild yam regeneration for their local conservation and their sustainable use in the Mahafaly region. Altogether, six species of wild yams and a total of 214 medicinal plants species from 68 families and 163 genera were identified in the study region. Results of the cluster and discriminant analysis indicated a clear pattern on resource, resulted in two groups of household and characterized by differences in livestock numbers, off-farm activities, agricultural land and harvests. A generalized linear model highlighted that economic factors significantly affect the collection intensity of wild yams, while the use of medicinal plants depends to a higher degree on socio-cultural factors. The gradient analysis on the distribution of the wild yam species revealed a clear pattern for species habitats. Species models based on NPMR (Nonparametric Multiplicative Regression analysis) indicated the importance of vegetation structure, human interventions, and soil characteristics to determine wild yam species distribution. The prediction of the current availability of wild yam resources showed that abundant wild yam resources are scarce and face high harvest intensity. Experiments on yams cultivation revealed that germination of seeds was enhanced by using pre-germination treatments before planting, vegetative regeneration performed better with the upper part of the tubers (corms) rather than the sets of tubers. In-situ regeneration was possible for the upper parts of the wild tubers but the success depended significantly on the type of soil. The use of manure (10-20 t ha¹) increased the yield of the D. alata and D. alatipes by 40%. We thus suggest the promotion of other cultivated varieties of D. alata found regions neighbouring as the Mahafaly Plateau.

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The objective of this study was to determine the optimum row spacing to improve the productivity of two soybean (Glycine max L.) varieties under the tropical hot sub-moist agroecological conditions of Ethiopia. A two-year split-plot design experiment was conducted to determine the effect of variety (Awasa-95 [early-maturing], Afgat [medium-maturing]) and row spacing (RS: 20, 25, 30, 35, 40, 45, 50, 55, 60 cm) on the productivity, nodulation and weed infestation of soybean. Seed and total dry matter (TDM) yield per ha and per plant, and weed dry biomass per m^2 were significantly affected by RS. Soybean variety had a significant effect on plant density at harvest and some yield components (plant height, number of seeds/pod, and 1000 seed weight). Generally, seed and TDM yield per ha and per plant were high at 40 cm RS, and weed dry biomass per m^2 was higher for RS >= 40 cm than for narrower RS. However, the results did not demonstrate a consistent pattern along the RS gradient. The medium-maturing variety Afgat experienced higher mortality and ended up with lower final plant density at harvest, but higher plant height, number of seeds per pod and 1000 seed weight than the early-maturing variety Awasa-95. The results indicate that 40 cm RS with 5 cm plant spacing within a row can be used for high productivity and low weed infestation of both soybean varieties in the hot sub-moist tropical environment of south-western Ethiopia.

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Many discussions about the music processing have occurred over the years. It is stated, on one hand, the existence of a single joint for grasping the music or any of its attributes by the Central Nervous System. Furthermore, it is claimed also the existence of multiple and diverse systems to understand each aspect of music. In general, model-independent set, studies focusing on the processing of sound components, specifically the musical tones, can significantly clarify the basic functioning of the auditory system and other higher brain functions. In this sense, one of the most prominent approaches in the study of sensory and perceptual processes of hearing, or changed unharmed, has been Neuroscience, which is interested in the interaction between the brain areas corresponding to different cognitive processes. Thus, the purpose of this study was to review the studies that dealt processing models of the attributes of tonal Western music, based on the conception that neuropsychological neural structures are interdependent sensory pathways.

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Este estudio busca contribuir a la evaluación del impacto económico que una mayor liberalización comercial en el Hemisferio Occidental, puede tener sobre los países miembros de la Comunidad Andina. Los escenarios de liberalización comercial más significativos se identifican y simulan, mediante el uso del modelo GTAP en su versión estándar de rendimientos constantes a escala. Los resultados básicos indican una muy baja coincidencia en la dirección de los cambios de bienestar esperables para los países andinos, bajo los cuatro escenarios analizados. De una forma muy simplificada, puede decirse que una mayor liberalización comercial implica pérdidas de bienestar para Colombia, Perú y Ecuador-Bolivia, en tanto que para Venezuela se encuentran ganancias bajo los escenarios que implementan el Área de Libre Comercio de las Américas y pérdidas bajo el que implementa el Acuerdo de Libre Comercio entre sus socios andinos y Estados Unidos. Los términos de intercambio juegan un papel determinante en estos resultados. En general se mueven en contra de estas economías, con la notoria excepción de Venezuela. Al parecer, los países andinos se han beneficiado en el pasado de la desviación de comercio que otras regiones han sufrido, como consecuencia de los acuerdos preferenciales de comercio en los cuales los primeros han participado. Con la erosión del acceso preferencial a otros mercados, implícita en los escenarios simulados, el aumento en la competencia tanto por el lado de las exportaciones como por el de las importaciones, tiende a ajustar la posición internacional de estos países, trayendo con ello nuevos retos para el manejo de sus economías.

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La corrupción sigue siendo uno de los principales problemas del Estado de Derecho en el siglo XXI. Su incidencia reduce la eficacia de la inversión, aumenta el valor de los bienes y servicios, reduce la competitividad de las empresas, vulnera la confianza de los ciudadanos en el ordenamiento jurídico y sobre todo condena a la miseria a quienes deben ser destinatarios de las políticas públicas.Sin embrago, la lucha que han realizado muchos gobiernos y funcionarios judiciales contra este fenómeno ha modificado sus formas de aparición, pues es cada vez menos frecuente la apropiación directa de los caudales públicos o la entrega de sobornos a los funcionarios, prefiriéndose métodos mucho más sutiles como los sobrecostos, la subcontratación masiva o la constitución de complicadas sociedades, en las cuales tienen participación los funcionarios públicos o sus familias.Este libro constituye un esfuerzo por el estudio jurídico y criminológico de la corrupción y los delitos contra la administración pública en Europa y Latinoamérica y reúne la selección de los temas penales más relevantes de la tesis doctoral del profesor Carlos Guillermo Castro Cuenca, denominada Aproximación a la Corrupción en la contratación pública y defendida en la universidad de Salamanca en febrero de 2008, con lo cual obtuvo la calificación de sobresaliente por unanimidad.

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Material de apoyo para la enseñanza de la lectura en la educación primaria. El texto tiene dos niveles de dificultad y dos tamaños de letra. El segundo nivel es para lectores más expertos. Ilustrado con una selección de fotografías para animar a los niños a hacer sus propias observaciones del mundo natural. Apropiado para niños a partir de seis años.

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Una adaptación de La Metamorfosis de Kafka, da pie a esta historia de invisibilidad en la infancia y la capacidad de adaptación para seguir adelante. Gregory Sampson se despierta una mañana y descubre que se ha convertido en un gigante escarabajo. Desconcertado por su extraña situación, Gregory hace recortes en su camisa para sacar los dos nuevos brazos y considera que las piernas extras le ayudarán a contar en clase de matemáticas. Nadie, con excepción de su mejor amigo, advierte su inexplicable transformación. Él sólo necesita atención amorosa, y la única manera que puede llegar a tenerla es subiéndose al techo de su dormitorio y dejar que pasen las horas.

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Study on the composition and distribution of Phytobenthic Assemblages of Addaia Bay (Menorca, Western Mediterranean)

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Las herramientas ETL (Extract, Transform, Load – extraer, transformar, cargar) permiten modelizar flujos de datos, facilitando la ejecución automática de procesos repetitivos. El intercambio de información entre dos modelos de datos heterogéneos es un claro ejemplo del tipo de tareas que pueden abordarse con software ETL. El proyecto Kettle es una herramienta ETL con licencia LGPL (Library General Public License) que utiliza técnicas de computación grid (ejecución paralela y distribuida) para poder procesar grandes cantidades de datos en un tiempo reducido. Kettle combina una potente ejecución en modo servidor con una intuitiva herramienta de escritorio para modelar los procesos y configurar los parámetros de ejecución. GeoKettle es una extensión de Kettle, que añade la posibilidad de tratar datos con componente geográfica, si bien está limitado a datos vectoriales y a ciertas operaciones espaciales muy concreta. El Centro Temático Europeo de Usos del Suelo e Información Espacial (ETC-LUSI) está impulsando un proyecto complementario, llamado BeETLe, que pretende ampliar drásticamente las capacidades de análisis y transformación espacial de GeoKettle. Para ello se ha elegido el proyecto Sextante, una librería de análisis espacial que incluye más de doscientos algoritmos ráster y vectoriales. La intención del proyecto BeETLe es integrar el conjunto de algoritmos de Sextante en GeoKettle, de forma que estén disponibles como transformaciones de GeoKettle. Las principales características de la herramienta BeETLe incluyen: automatización de procesos de análisis espacial o de transformaciones repetitivas de datos espaciales, ejecución paralela y distribuida (grid computing), capacidad para procesar grandes cantidades de datos sin limitaciones de memoria, y soporte de datos ráster y vectorial. Los usuarios actuales de Sextante descubrirán que BeETLe les propone una forma de trabajo sencilla e intuitiva, que añade a Sextante toda la potencia que ofrecen las herramientas ETL para procesar y transformar información en bases de datos