Análisis de la política comercial de Singapur como estrategia de la política exterior en la Asociación de Naciones del Sudeste Asiático (ASEAN) y el Foro de Cooperación Económico Asia-Pacífico (APEC). Periodo 1998-2009

Análisis de la política exterior de Singapur y cómo está determinada por las políticas comerciales del país. Analiza cómo la participación en una organización internacional y un foro económico benefician al desarrollo económico del país.

Mediastinitis post revascularización miocárdica: impacto del cambio de profilaxis antibiótica en la fundación Cardioinfantil 2012 - 2013

INTRODUCCIÓN. La mediastinitis posterior a cirugía de revascularización miocárdica es una infección infrecuente, pero potencialmente fatal. En la Fundación Cardioinfantil se ha observado una tendencia al incremento de la misma en los últimos años, obligando a un cambio en las medidas de profilaxis antimicrobiana, pasando de cefalosporinas a vancomicina – gentamicina, sin embargo no se conoce aún el impacto de estas medidas. OBJETIVO: Determinar si el cambio de la profilaxis antibiótica en pacientes sometidos a revascularización miocárdica influye en una disminución de la incidencia de mediastinitis durante los años 2012 – 2013. METODOLOGÍA: Estudio de cohortes retrospectivo, evaluando la incidencia de mediastinitis post revascularización miocárdica, en pacientes expuestos a 2 diferentes tipos de profilaxis antimicrobiana (cefalosporinas vs vancomicina-gentamicina). Se describieron los patrones de susceptibilidad y resistencia de los patógenos encontrados en mediastinitis y la mortalidad de esta patología. RESULTADOS: Los patógenos más frecuentemente aislados en la mediastinitis fueron Staphylococcus aureus y Klebsiella pneumoniae, en la mayoría monomicrobiano. Se encontraron patógenos con perfiles de resistencia como betalactamasas de espectro extendido en Gram negativos y resistencia a la meticilina en cocos Gram positivos. El RR de mediastinitis del grupo expuesto a vancomicina-gentamicina respecto al grupo de cefalosporinas fue de 0,9 con IC 95% 0,28 – 3,28. CONCLUSIÓN: la epidemiologia microbiana de la mediastinitis no difiere de la reportada en otras series. La profilaxis antimicrobiana con vancomicina - gentamicina en pacientes sometidos a revascularización miocárdica, no redujo la incidencia de mediastinitis. Se propone regresar a la terapia de profilaxis con cefalosporinas.

River story.

Miles de ríos ayudan a dar forma a la superficie de nuestro planeta. Llevan agua y vida a las tierras por las que pasan y a todos los que hacen uso de ellas. Cada río es diferente y cada uno hace su propio y emocionante viaje. Vamos a conocer la historia de uno de ellos, desde su nacimiento en lo alto de las montañas, cuando es pequeño y de aguas heladas, hasta su fin en la desembocadura a orillas del mar, produciendo unas curvas llamadas meandros.

Modern times, 1750-1990.

Se agrupa en tres grandes líneas temáticas: revolución, los derechos y libertades y la guerra, cada una de las cuales se divide en capítulos ó lecciones, con sus propios objetivos. Estos objetivos son una combinación, por una parte, de la adquisición de conocimientos y contenidos que deben estudiar los alumnos y por otra, la adquisición de unas ideas históricas muy claras que también deben utilizar y desarrollar en actividades posteriores. Esta orientado a la etapa 3 (Key stage 3) de secundaria del curriculo nacional inglés y se edita en dos versiones, ésta es la principal (core) y se diferencia de la edición básica (foundation) en tener una mayor extensión de texto. Se acompaña de un recurso para el profesor con material de apoyo para trabajar con los alumnos.

Modern times, 1750-1990 : teaching and learning file.

Material didáctico formado por unas notas detalladas que contienen orientación y asesoramiento para que el profesor utilice las hojas de trabajo que les siguen. Estas hojas de trabajo establecen cuáles son los objetivos y los resultados del aprendizaje que han de cumplir los alumnos, y para ello, se incluyen de varios tipos. Unas, pueden utilizarse para tareas de apoyo referidas al libro del alumno y, otras, son para actividades autónomas ó genéricas. Este recurso contiene también las hojas de trabajo para los libros del alumno editados en dos versiones: básica (foundation) y principal (core).

The Freeing of Nelson Mandela.

Breve biografía de Nelson Mandela que cuenta cómo tras veintisiete años en prisión se convirtió en un símbolo de la libertad para Sudáfrica y llegó a ser el primer presidente de raza negra del país, analiza el contexto histórico y cómo llegó a tener una gran influencia en la población sudafricana consiguiendo el fin del régimen del apartheid. Al final del libro se incluye un glosario de términos y una línea de tiempo con un resumen cronológico de los acontecimientos más importantes de la historia de Sudáfrica.

Dispersal capacity and diet breadth modify the response of wild bees to habitat loss

Habitat loss poses a major threat to biodiversity, and species-specific extinction risks are inextricably linked to life-history characteristics. This relationship is still poorly documented for many functionally important taxa, and at larger continental scales. With data from five replicated field studies from three countries, we examined how species richness of wild bees varies with habitat patch size. We hypothesized that the form of this relationship is affected by body size, degree of host plant specialization and sociality. Across all species, we found a positive species–area slope (z ¼ 0.19), and species traits modified this relationship. Large-bodied generalists had a lower z value than small generalists. Contrary to predictions, small specialists had similar or slightly lower z value compared with large specialists, and small generalists also tended to be more strongly affected by habitat loss as compared with small specialists. Social bees were negatively affected by habitat loss (z ¼ 0.11) irrespective of body size. We conclude that habitat loss leads to clear shifts in the species composition of wild bee communities.

Impacts of a pesticide on pollinator species richness at different spatial scales

Pesticides are an important potential cause of biodiversity and pollinator decline. Little is known about the impacts of pesticides on wild pollinators in the field. Insect pollinators were sampled in an agricultural system in Italy with the aim of detecting the impacts of pesticide use. The insecticide fenitrothion was over 150 times greater in toxicity than other pesticides used in the area, so sampling was set up around its application. Species richness of wild bees, bumblebees and butterflies were sampled at three spatial scales to assess responses to pesticide application: (i) the ‘field’ scale along pesticide drift gradients; (ii) the ‘landscape’ scale sampling in different crops within the area and (iii) the ‘regional’ scale comparing two river basins with contrasting agricultural intensity. At the field scale, the interaction between the application regime of the insecticide and the point in the season was important for species richness. Wild bee species richness appeared to be unaffected by one insecticide application, but declined after two and three applications. At the landscape scale, the species richness of wild bees declined in vine fields where the insecticide was applied, but did not decline in maize or uncultivated fields. At the regional scale, lower bumblebee and butterfly species richness was found in the more intensively farmed basin with higher pesticide loads. Our results suggest that wild bees are an insect pollinator group at particular risk from pesticide use. Further investigation is needed on how the type, quantity and timing of pesticide application impacts pollinators.

Parallel declines in pollinators and insect-pollinated plants in Britain and the Netherlands

Despite widespread concern about declines in pollination services, little is known about the patterns of change in most pollinator assemblages. By studying bee and hoverfly assemblages in Britain and the Netherlands, we found evidence of declines (pre- versus post-1980) in local bee diversity in both countries; however, divergent trends were observed in hoverflies. Depending on the assemblage and location, pollinator declines were most frequent in habitat and flower specialists, in univoltine species, and/or in nonmigrants. In conjunction with this evidence, outcrossing plant species that are reliant on the declining pollinators have themselves declined relative to other plant species. Taken together, these findings strongly suggest a causal connection between local extinctions of functionally linked plant and pollinator species.

Conservation ecology of bees: populations, species and communities

Recent concerns regarding the decline of plant and pollinator species, and the impact on ecosystem functioning, has focused attention on the local and global threats to bee diversity. As evidence for bee declines is now accumulating from over broad taxonomic and geographic scales, we review the role of ecology in bee conservation at the levels of species, populations and communities. Bee populations and communities are typified by considerable spatiotemporal variation; whereby autecological traits, population size and growth rate, and plant-pollinator network architecture all play a role in their vulnerability to extinction. As contemporary insect conservation management is broadly based on species- and habitat-targeted approaches, ecological data will be central to integrating management strategies into a broader, landscape scale of dynamic, interconnected habitats capable of delivering bee conservation in the context of global environmental change.

Plant-pollinator biodiversity and pollination services in a complex Mediterranean landscape

Mediterranean landscapes comprise a complex mosaic of different habitats that vary in the diversity of their floral communities, pollinator communities and pollination services. Using the Greek Island of Lesvos as a model system, we assess the biodiversity value of six common habitats and measure ecosystemic 'health' using pollen grain deposition in three core flowering plants as a measure of pollination services. Three fire-driven habitats were assessed: freshly burnt areas, fully regenerated pine forests and intermediate age scrub; in addition we examined oak woodlands, actively managed olive groves and groves that had been abandoned from agriculture. Oak woodlands, pine forests and managed olive groves had the highest diversity of bees. The habitat characteristics responsible for structuring bee communities were: floral diversity, floral abundance, nectar energy availability and the variety of nectar resources present. Pollination services in two of our plant species, which were pollinated by a limited sub-set of the pollinator community, indicated that pollination levels were highest in the burnt and mature pine habitats. The third species, which was open to all flower visitors, indicated that oak woodlands had the highest levels of pollination from generalist species. Pollination was always more effective in managed olive groves than in abandoned groves. However, the two most common species of bee, the honeybee and a bumblebee, were not the primary pollinators within these habitats. We conclude that the three habitats of greatest overall value for plant-pollinator communities and provision of the healthiest pollination services are pine forests, oak woodland and managed olive groves. We indicate how the highest value habitats may be maintained in a complex landscape to safeguard and enhance pollination function within these habitats and potentially in adjoining agricultural areas. (c) 2005 Elsevier Ltd. All rights reserved.

Declines of managed honey bees and beekeepers in Europe

Growing evidence indicates that European managed honey bees are in decline, but information for Europe remains patchy and localized. Here we compile data from 18 European countries to assess trends in the number of honey bee colonies and beekeepers between 1965 and 2005. We found consistent declines in colony numbers in central European countries and some increases in Mediterranean countries. Beekeeper numbers have declined in all of the European countries examined. Our data support the view that honey bees are in decline at least in some regions, which is probably closely linked to the decreasing number of beekeepers. Our data on colony numbers and beekeepers must, however, be interpreted with caution due to different approaches and socioeconomic factors in the various countries, thereby limiting their comparability. We therefore make specific recommendations for standardized methodologies to be adopted at the national and global level to assist in the future monitoring of honey bees.

Response of plant-pollinator communities to fire: changes in diversity, abundance and floral reward structure

Globally, plant-pollinator communities are subject to a diverse array of perturbations and in many temperate and semi-arid systems fire is a dominant structuring force. We present a novel and highly integrated approach, which quantifies, in parallel, the response to fire of pollinator communities, floral communities and floral reward structure. Mt Carmel, Israel is a recognised bee-flower biodiversity hotspot, and using a chronosequence of habitats with differing post-fire ages, we follow the changes in plant-pollinator community organisation from immediately following a burn until full regeneration of vegetation. Initially, fire has a catastrophic effect on these communities, however, recovery is rapid with a peak in diversity of both flowers and bees in the first 2 years post-fire, followed by a steady decline over the next 50 years. The regeneration of floral communities is closely matched by that of their principal pollinators. At the community level we quantify, per unit area of habitat, key parameters of nectar and pollen forage known to be of importance in structuring pollinator communities. Nectar Volume, nectar water content, nectar concentration and the diversity of nectar foraging niches are all greatest immediately following fire with a steady decrease as regeneration proceeds. Temporal changes in energy availability for nectar, pollen, total energy (nectar + pollen) and relative importance of pollen to nectar energy show a similar general decline with site age, however, the pattern is less clear owing to the highly patchy distribution of floral resources. Changes in floral reward structure reflect the general shift from annuals (generally low-reward open access flowers) to perennials (mostly high-reward and restricted access flowers) as post-fire regeneration ensues. The impact of fire on floral communities and their associated rewards have clear implications for pollinator community structure and we discuss this and the role of other disturbance factors on these systems.

Linking bees and flowers: How do floral communities structure pollinator communities?

Pollinators provide essential ecosystem services, and declines in some pollinator communities around the world have been reported. Understanding the fundamental components defining these communities is essential if conservation and restoration are to be successful. We examined the structure of plant-pollinator communities in a dynamic Mediterranean landscape, comprising a mosaic of post-fire regenerating habitats, and which is a recognized global hotspot for bee diversity. Each community was characterized by a highly skewed species abundance distribution, with a few dominant and many rare bee species, and was consistent with a log series model indicating that a few environmental factors govern the community. Floral community composition, the quantity and quality of forage resources present, and the geographic locality organized bee communities at various levels: (1) The overall structure of the bee community (116 species), as revealed through ordination, was dependent upon nectar resource diversity (defined as the variety of nectar volume-concentration combinations available), the ratio of pollen to nectar energy, floral diversity, floral abundance, and post-fire age. (2) Bee diversity, measured as species richness, was closely linked to floral diversity (especially of annuals), nectar resource diversity, and post-fire age of the habitat. (3) The abundance of the most common species was primarily related to post-fire age, grazing intensity, and nesting substrate availability. Ordination models based on age-characteristic post-fire floral community structure explained 39-50% of overall variation observed in bee community structure. Cluster analysis showed that all the communities shared a high degree of similarity in their species composition (27-59%); however, the geographical location of sites also contributed a smaller but significant component to bee community structure. We conclude that floral resources act in specific and previously unexplored ways to modulate the diversity of the local geographic species pool, with specific disturbance factors, superimposed upon these patterns, mainly affecting the dominant species.

Nectar resource diversity organises flower-visitor community structure

Communities of nectar-producing plants show high spatio-temporal variation in the patterns of volume and concentration presentation. We illustrate a novel approach for quantifying nectar reward structures in complex communities, demonstrating that nectar resource diversity (defined as the variety of nectar volume-concentration combinations available) may be a fundamental factor organising nectarivore communities. In a series of diverse bee and entomophilous flower communities in Israel, our measure of nectar resource diversity alone explains the majority of variation in bee species richness, while other nectar variables (volume, concentration, energy value, and water content) have little predictive value per se. The new measure of nectar resource diversity is highly correlated with floral species richness and particularly with the species richness of annuals, yet it is additive in its effect on bee diversity. We conclude that relying solely upon measurements of mean nectar volume and mean nectar concentration overlooks a key characteristic of community-level reward structure, nectar resource diversity, so that previous studies may have failed to identify an important determinant of flower-visitor community structure.