1,927 research outputs found

    Diagnosis of paediatric HIV/AIDS.

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    (East African Medical Journal: 2002 79(3): 109-110

    Annotated checklist and biogeographic composition of the Lycaenidae (Lepidoptera) of Trinidad, West Indies

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    A revised annotated checklist for the butterfl y family Lycaenidae (Lepidoptera) of Trinidad is presented, updating nomenclature, and indicating synonyms from earlier lists and papers. The checklist includes 131 species of Lycaenidae, comprising 127 species of 49 genera of Eumaeini, Theclinae, and four species of three genera of Polyommatinae. There are more than 30 new island records. No lycaenid species is endemic to Trinidad, and the fauna consists primarily of widespread species (71%) that occur from Central America to the Amazon Basin. However, the primary biogeographic affi nity is the Amazon Region, where 94% of the Trinidad lycaenid fauna also occurs. Corrections are made to the literature cited in the fi rst author’s earlier checklists on other Trinidad butterfl ies. Resumen. Se presenta una lista anotada para la familia de mariposas Lycaenidae (Lepidoptera) de Trinidad, actualizando la nomenclatura e indicando sinónimos de listas y artículos prévios. La lista incluye 131 especies de Lycaenidae, que comprende 127 especies de 49 géneros de Eumaeini, Theclinae, y cuatro especies de tres géneros de Polyommatinae. Se presentan más de 30 nuevo registros procedente de la isla. Ninguna especies de lycaenido es endémico de Trinidad, y la fauna consiste principalmente de especies de amplia distribución (71%) que ocurren desde Centroamérica hasta la Cuenca del Amazonas. Sin embargo, la principal afi nidad biogeográfi ca es la Región Amazónica, donde el 94% de la fauna de lycaenidos de Trinidad ocurren. Se hacen correcciones en la literatura citada de las listas anotadas anteriores del primer autor sobre otras mariposas de Trinidad

    Potencial futuro e investigacion necesaria para el incremento de la yuca

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    The possibilities of underdeveloped countries to satisfy their needs for food and to improve the standard of Eving through cassava production are analyzed. The following aspects are studied: potential cassava production (current and potential situation), general research policies and areas (var. development, pest control, agronomic practices, and multiple cropping), transfer of technology, utilization of cassava in human and animal nutrition and in the production of alcohol. Tables are included on potential yields, production costs, and price-elasticity, and income in Indonesia. (CIAT)Se analizan las posibilidades de los paises subdesarrollados para satisfacer sus necesidades de alimentacion y mejorar el nivel de vida con base en la produccion de yuca. Se contemplan los siguientes aspectos: produccion potencial de la yuca (situacion actual y potencial), politica general de la investigacion y sus areas (desarrollo var., manejo de plagas, practicas agronomicas y cultivos multiples), transferencia de tecnologia, utilizacion de la yuca en la alimentacion humana, animal y en la produccion de alcohol. Se incluyen cuadros de rendimiento potencial, costos de produccion, y de elasticidad precio e ingreso en Indonesia. (CIAT

    The fluctuating resource hypothesis explains invasibility, but not exotic advantage following disturbance

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    Invasibility is a key indicator of community susceptibility to changes in structure and function. The fluctuating resource hypothesis (FRH) postulates that invasibility is an emergent community property, a manifestation of multiple processes that cannot be reliably predicted by individual community attributes like diversity or productivity. Yet, research has emphasized the role of these individual attributes, with the expectation that diversity should deter invasibility and productivity enhance it. In an effort to explore how these and other factors may influence invasibility, we evaluated the relationship between invasibility and species richness, productivity, resource availability, and resilience in experiments crossing disturbance with exotic seed addition in 1-m2 plots replicated over large expanses of grasslands in Montana, USA and La Pampa, Argentina. Disturbance increased invasibility as predicted by FRH, but grasslands were more invasible in Montana than La Pampa whether disturbed or not, despite Montana´s higher species richness and lower productivity. Moreover, invasibility correlated positively with nitrogen availability and negatively with native plant cover. These patterns suggested that resource availability and the ability of the community to recover from disturbance (resilience) better predicted invasibility than either species richness or productivity, consistent with predictions from FRH. However, in ambient, unseeded plots in Montana, disturbance reduced native cover by >50% while increasing exotic cover >200%. This provenance bias could not be explained by FRH, which predicts that colonization processes act on species? traits independent of origins. The high invasibility of Montana grasslands following disturbance was associated with a strong shift from perennial to annual species, as predicted by succession theory. However, this shift was driven primarily by exotic annuals, which were more strongly represented than perennials in local exotic vs. native species pools. We attribute this provenance bias to extrinsic biogeographic factors such as disparate evolutionary histories and/or introduction filters selecting for traits that favor exotics following disturbance. Our results suggest that (1) invasibility is an emergent property best explained by a community´s efficiency in utilizing resources, as predicted by FRH but (2) understanding provenance biases in biological invasions requires moving beyond FRH to incorporate extrinsic biogeographic factors that may favor exotics in community assembly.Fil: Pearson, Dean. United State Forest Service; Estados Unidos. University of Montana; Estados UnidosFil: Ortega, Yvette K.. United State Forest Service; Estados UnidosFil: Villarreal, Diego. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales; ArgentinaFil: Lekberg, Ylva. University of Montana; Estados UnidosFil: Cock, Marina Cecilia. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; ArgentinaFil: Eren, Ozkan. Adnan Menderes Universitesi; TurquíaFil: Hierro, Jose Luis. Consejo Nacional de Investigaciones Científicas y Técnicas. Instituto de Ciencias de la Tierra y Ambientales de La Pampa. Universidad Nacional de La Pampa. Facultad de Ciencias Exactas y Naturales. Instituto de Ciencias de la Tierra y Ambientales de La Pampa; Argentin

    On hawser force criteria for navigation lock design: Case study of maritime locks in port of Antwerp

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    The first part of this paper offers a general reflection upon the issue of mooring line forces and ship behaviour during filling/emptying of (maritime) navigation locks. The philosophy behind the so-called hawser force criterion and the classical approach to deal with it in design studies, is described first. Secondly, some innovations in the definition, verification and validation of the design criteria are highlighted. In the second part of this paper, a case study is presented focusing on two maritime locks in the Port of Antwerp (Belgium): the Zandvliet lock (L x W = 500m x 57m) and the Berendrecht lock (L x W = 500m x 68m). To illustrate and comment upon the hawser force issues, results of scale modelling, in situ measurements and numerical modelling are discussed, in comparison to published hawser force criteria

    Experimental harvesting of fish populations drives genetically based shifts in body size and maturation

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    Size-selective harvesting in commercial fisheries can induce rapid changes in biological traits. While experimental and wild harvested populations often exhibit clear shifts in body size and maturation associated with fishing pressure, the relative contributions of genetic and environmental factors to these shifts remain uncertain and have been much debated. To date, observations of so-called fisheries-induced evolution (FIE) have been based solely on phenotypic measures, such as size data. Genetic data are hitherto lacking. Here, we quantify genetic versus environmental change in response to size-selective harvesting for small and large body size in guppies (Poecilia reticulata) across three generations of selection. We document for the first time significant changes at individual genetic loci, some of which have previously been associated with body size. In contrast, variation at neutral microsatellite markers was unaffected by selection, providing direct genetic evidence for rapid evolution induced by size-selective harvesting. These findings demonstrate FIE in an experimental system, with major implications for the sustainability of harvested populations, as well as impacts on size-structured communities and ecosystem processes. These findings highlight the need for scientists and managers to reconsider the capacity of harvested stocks to adapt to, and recover from, harvesting and predation. © 2013 The Ecological Society of America

    Using a gamified monitoring app to change adolescents' snack intake : the development of the REWARD app and evaluation design

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    Background: As the snacking pattern of European adolescents is of great concern, effective interventions are necessary. Till now health promotion efforts in children and adolescents have had only limited success in changing adolescents' eating patterns and anthropometrics. Therefore, the present study proposes an innovative approach to influence dietary behaviors in youth based on new insights on effective behavior change strategies and attractive intervention channels to engage adolescents. This article describes the rationale, the development, and evaluation design of the 'Snack Track School' app. The aim of the app is to improve the snacking patterns of Flemish 14- to 16-year olds. Methods: The development of the app was informed by the systematic, stepwise, iterative, and collaborative principles of the Intervention Mapping protocol. A four week mHealth intervention was developed based on the dual-system model with behavioral change strategies targeting both the reflective (i.e., active learning, advance organizers, mere exposure, goal-setting, monitoring, and feedback) and automatic processes (i.e., rewards and positive reinforcement). This intervention will be evaluated via a controlled pre-post design in Flemish schools among 1400 adolescents. Discussion: When this intervention including strategies focused on both the reflective and automatic pathway proves to be effective, it will offer a new scientifically-based vision, guidelines and practical tools for public health and health promotion (i.e., incorporation of learning theories in intervention programs)
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