884 resultados para Feature vectors


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INTRODUCTION: An entomological study was conducted as part of a vector-monitoring program in the area associated with the Santo Antônio hydroelectric system in State of Rondônia, Western Amazonian Brazil. METHODS: Fourteen sampling sites were surveyed to obtain data on the potential vectors of Leishmania spp. in the area. Sand flies were collected from 2011 to 2014 during the months of January/February (rainy season), May/June (dry season), and September/October (intermediary season) using light traps arranged in three vertical strata (0.5, 1, and 20m). RESULTS : A total of 7,575 individuals belonging to 62 species/subspecies were collected. The five most frequently collected sand flies were Psychodopygus davisi (Root) (36.67%), Trichophoromyia ubiquitalis (Mangabeira) (8.51%), Nyssomyia umbratilis (Ward & Fraiha) (6.14%), Bichromomyia flaviscutellata (Mangabeira) (5.74%), and Psychodopygus complexus (Mangabeira) (5.25%). These species have been implicated in the transmission of American cutaneous leishmaniasis agents in the Brazilian Amazon region and described as potential vectors of this disease in the study area. CONCLUSIONS: Additional surveillance is needed, especially in areas where these five species of sand fly are found.

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AbstractIn the last 15 years, different types of Triatominae resistance to different insecticides have been reported; thus, resistance may be more widespread than known, requiring better characterization and delimitation, which was the aim of this review. This review was structured on a literature search of all articles from 1970 to 2015 in the PubMed database that contained the keywords Insecticide resistance and Triatominae . Out of 295 articles screened by title, 33 texts were selected for detailed analysis. Insecticide resistance of Triatomines is a complex phenomenon that has been primarily reported in Argentina and Bolivia, and is caused by different factors (associated or isolated). Insecticide resistance of Triatominae is a characteristic inherited in an autosomal and semi-dominant manner, and is polygenic, being present in both domestic and sylvatic populations. The toxicological profile observed in eggs cannot be transposed to different stages of evolution. Different toxicological profiles exist at macro- and microgeographical levels. The insecticide phenotype has both reproductive and developmental costs. Different physiological mechanisms are involved in resistance. Studies of Triatomine resistance to insecticides highlight three deficiencies in interpreting the obtained results: I) the vast diversity of methodologies, despite the existence of a single guiding protocol; II) the lack of information on the actual impact of resistance ratios in the field; and III) the concept of the susceptibility reference lineage. Research on the biological and behavioral characteristics of each Triatominae species that has evolved resistance is required in relation to the environmental conditions of each region.

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Natural selection favors the survival and reproduction of organisms that are best adapted to their environment. Selection mechanism in evolutionary algorithms mimics this process, aiming to create environmental conditions in which artificial organisms could evolve solving the problem at hand. This paper proposes a new selection scheme for evolutionary multiobjective optimization. The similarity measure that defines the concept of the neighborhood is a key feature of the proposed selection. Contrary to commonly used approaches, usually defined on the basis of distances between either individuals or weight vectors, it is suggested to consider the similarity and neighborhood based on the angle between individuals in the objective space. The smaller the angle, the more similar individuals. This notion is exploited during the mating and environmental selections. The convergence is ensured by minimizing distances from individuals to a reference point, whereas the diversity is preserved by maximizing angles between neighboring individuals. Experimental results reveal a highly competitive performance and useful characteristics of the proposed selection. Its strong diversity preserving ability allows to produce a significantly better performance on some problems when compared with stat-of-the-art algorithms.

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Software product lines (SPL) are diverse systems that are developed using a dual engineering process: (a)family engineering defines the commonality and variability among all members of the SPL, and (b) application engineering derives specific products based on the common foundation combined with a variable selection of features. The number of derivable products in an SPL can thus be exponential in the number of features. This inherent complexity poses two main challenges when it comes to modelling: Firstly, the formalism used for modelling SPLs needs to be modular and scalable. Secondly, it should ensure that all products behave correctly by providing the ability to analyse and verify complex models efficiently. In this paper we propose to integrate an established modelling formalism (Petri nets) with the domain of software product line engineering. To this end we extend Petri nets to Feature Nets. While Petri nets provide a framework for formally modelling and verifying single software systems, Feature Nets offer the same sort of benefits for software product lines. We show how SPLs can be modelled in an incremental, modular fashion using Feature Nets, provide a Feature Nets variant that supports modelling dynamic SPLs, and propose an analysis method for SPL modelled as Feature Nets. By facilitating the construction of a single model that includes the various behaviours exhibited by the products in an SPL, we make a significant step towards efficient and practical quality assurance methods for software product lines.

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Tese de Doutoramento em Biologia Molecular e Ambiental - Especialidade em Biologia Celular e Saúde

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This chapter deals with the characterization of the basic constraints between two vectors. This issue plays a crucial role in the formulation of constraint equations for mechanical joints. In particular, relations between two parallel and two perpendicular vectors are derived. Moreover, formulation for a vector that connects two generic points is presented. The material described here is developed under the framework of multibody systems formulation for spatial systems.

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En la hipótesis de trabajo del presente proyecto se considera la importancia del metabolismo de lípidos y proteínas en los insectos hematófagos, en particular en los vectores de la enfermedad de Chagas, para afrontar exitosamente la demanda energética de la reproducción. Las hembras de estas especies pueden ingerir una comida de sangre abundante en lípidos y proteínas, los que son modificados en el intestino para su utilización y posterior almacenamiento en estructuras organizadas en el tejido ovárico, sustentando así el rápido crecimiento de los ovocitos. Estos aspectos resultan críticos para el ciclo de vida del insecto y para el mantenimiento de la cadena epidemiológica de la enfermedad. En estas especies, recientemente hemos caracterizado a nivel bioquímico y celular la interacción entre lipoproteínas y tejidos [Fruttero y col., Insect Biochem. Mol. Biol. 39: 322-331 (2009); Fruttero y col. Biocel 33 (3): 260 (2009)] y las fases del ciclo reproductivo [Aguirre y col., J. Insect Physiol. 54: 393-402 (2008)]. No obstante, los factores que participan en su regulación son aún escasamente conocidos. En este contexto, el estudio propone emplear dos especies de triatominos con el objeto de: (1) caracterizar los factores involucrados en la formación y regulación de reservas nutricionales en los ovocitos; (2) analizar los eventos que participan en la regresión del tejido ovárico: atresia folicular y mecanismos de muerte celular. (3) evaluar el impacto de productos naturales (ureasas vegetales y péptidos derivados) en el desarrollo del tejido ovárico. Para la ejecución de los objetivos se llevarán a cabo ensayos in vivo e in vitro con trazadores fluorescentes, fraccionamiento subcelular, estudios de expresión de proteínas (mRNA y proteína), estudios histo-morfológicos, ultraestructurales e inmunocitoquímicos, microscopía láser confocalizada, ensayos de actividad enzimática, ELISA, western-blot, electroforesis bidimensional, espectrometria de masas en tándem, etc. También se evaluarán los mecanismos de muerte celular (apoptosis/autofagia) mediante microscopía electrónica, detección de apoptosis in situ (TUNEL), inmunofluorescencia, etc. Los resultados obtenidos permitirán un mejor conocimiento sobre la fisiología y bioquímica de estos vectores, los que resultan indispensables en el diseño de nuevas estrategias para su control. Debido a la carencia de un tratamiento específico para la enfermedad y a la falta de métodos preventivos (vacuna), el control del vector es una de las vías más importantes para reducir la incidencia de la enfermedad. Actualmente, la situación socio-económica que sufren amplios núcleos de nuestra población propicia condiciones de vida que facilitan la reproducción de los vectores y la transmisión vectorial del parásito. El estudio permitirá además explorar aspectos bioquímicos y celulares básicos, generando conocimientos que podrían ser extensivos a otros insectos de importancia económica en la ganadería y/o agricultura. The aim of this project is to analyze the biochemical and cellular events involved in the lipid and protein metabolism in Chagas' disease vectors, and to evaluate their impact on the physiology of reproduction, particularly in the formation of nutritional resources in developing oocytes. At present, little is known about these critical aspects for the life cycle of the insect and for the epidemiology of the disease. The experimental approaches, which will be carried out using two species of triatomines, were designed: (1) to characterize factors involved in the formation and regulation of nutritional resources in developing oocytes; (2) to analyze the biochemical and cellular events that play a role during the regression of ovarian tissue, including the processes of oocyte resorption and programmed cell death. (3) to evaluate the impact of natural products (ureases from jackbean and related peptides) in the development of ovarian tissue. Methods and techniques involved in the project are: in vivo and in vitro assays with fluorescent tracers, ELISA, chemical assays, enzyme activities, western-blot; protein expression (mRNA), histological techniques, immunohistochemical and ultrastructural studies. Cell death will be analyzed by detection of apoptosis in situ (TUNEL), immunofluorescence (for autophagy), among others. The results obtained from the study will offer the opportunity to explore important aspects in the biology and physiology of Chagas' disease vectors that could be of potential utility in designing alternative strategies for the control of the insect.

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La Enfermedad de Chagas es considerada en términos sociales y económicos, una de las enfermedades parasíticas más importantes de América Latina. La transmisión vectorial de esta enfermedad ha sido interrumpida en gran parte de América Latina sin embargo, el control vectorial no ha podido lograr la sostenibilidad y la efectividad necesarias para interrumpir la transmisión vectorial en la región del Gran Chaco de Argentina, Bolivia y Paraguay. La permanencia de poblaciones residuales de triatominos en estructuras peridomiciliarias permite una rápida recuperación del vector, sugiriéndose que estas poblaciones serían la principal fuente de reinfestación de la vivienda humana. Este escenario plantea por lo tanto la necesidad de estudiar con más profundidad las poblaciones de triatominos presentes en los peridomicilios para comprender su dispersión, capacidad de domiciliación y así entender el posible peligro que pueden presentar para el hombre como especies vectoras de la enfermedad de Chagas. Dentro de la provincia de Córdoba existen áreas que por la presencia histórica de triatomineos, la notificación reciente de casos de Chagas vectorial y el registro de especies silvestres invadiendo los domicilios merecen un estudio más profundo. Es por ello que se propone realizar un relevamiento de las especies de triatomineos que habitan los domicilios y peridomicilios en estas zonas, calcular los índices de infección con Trypanosoma cruzi que presentan, caracterizar su perfil alimentario, los factores de riesgo que favorecen su refugio, su capacidad dispersiva y diferenciar fenotípicamente entre las poblaciones peridomésticas para comprender mejor el posible peligro que pueden presentar para el hombre como especies vectoras de la enfermedad de Chagas. Además, y de manera complementaria, se aplicarán estrategias educativas en el ámbito escolar que sirvan para la vigilancia entomológica y acciones preventivas de la Enfermedad de Chagas. La determinación del perfil alimentario pautará la potencialidad de cada vector, siendo esta información fundamental para el análisis de situaciones epidemiológicas de riesgo. La capacidad dispersiva y la diferenciación fenotípica de las poblaciones permitirán conocer el posible movimiento y flujo de triatominos desde y hacia la vivienda humana. La determinación de los factores que favorecen el refugio de triatominos permitirá conocer el nivel de riesgo en que se encuentra cada domicilio. Además, considerando la importancia de las poblaciones peridomésticas en los procesos de reinfestación, se analizará la capacidad dispersiva que presentan los triatominos a través de su estado nutricional y, mediante la morfometría clásica y geométrica, se analizará como se estructura la diversidad fenotípica en los domicilios y peridomicilios. La aplicación de estrategias educativas en el ámbito escolar favorecerá el conocimiento en general de esta enfermedad, la vigilancia entomólogica y las acciones preventivas por parte de los niños en edad escolar. Chagas disease is considered socially and economically, one of the most important parasitic diseases in Latin America. Vector transmission of this disease has been interrupted in much of Latin America, however, vector control has failed to achieve sustainability and effectiveness necessary to interrupt the vector transmission in the Gran Chaco region of Argentina, Bolivia and Paraguay. The permanence of residual populations of triatomine in the peridomiciliary structures enables fast recovery of the vector, suggesting that these populations would be the main source of reinfestation of human dwellings. Within the province of Córdoba, there are areas that the historical presence of triatomines, the recent notification of cases of Chagas vector and recording of wild species invading the homes deserve further study. That is why, there will be a survey of Triatominae species that inhabit the domiciles and peridomiciles in these areas, rates of infection with Trypanosoma cruzi, their host feeding preferences, the risk factors that favor its shelter, their dispersive capacity and phenotypic differentiation between peridomestic populations, to better understand the potential danger they may present to the man and vector species of Chagas disease. In addition, complementary, educational strategies in schools were implemented that serve for entomological surveillance and preventive actions of Chagas disease. The determination of the potential food profile patterns of each vector is essential for epidemiological analysis of risk situations. Dispersive capacity and phenotypic differentiation of populations may allow understanding the movement and flow of triatomines and from human habitation.

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Magdeburg, Univ., Fak. für Informatik, Diss., 2011

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Magdeburg, Univ., Fak. für Informatik, Diss., 2011

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Magdeburg, Univ., Fak. für Informatik, Diss., 2015

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...In dieser Arbeit untersuche ich den ”Fluch der Dimensionen” mittels dem Begriff der Distanzkonzentration. Ich zeige, dass dieser Effekt im Datenmodell mittels der paarweisen Kovarianzkoeffizienten der Randverteilungen beschrieben werden kann. Zusätzlich vergleiche ich 10 prototypbasierte Clusteralgorithmen mittels 800.000 Clusterergebnissen von künstlich erzeugten Datensätzen. Ich erforsche, wie und warum Clusteralgorithmen von der Anzahl der Merkmale beeinflusst werden. Mit den Clusterergebnissen untersuche ich außerdem, wie gut 5 der populärsten Clusterqualitätsmaße die tatsächliche Clusterqualität schätzen.

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Trypanosoma cruzi infected Rhodnius robustus and/or Rhodnius pictipes were commonly found, in large numbers, in the Brazilian Amazonian palms Maximiliana regia ("inajá"), Acrocomia sclerocarpa ("mucajá") and Orbignya speciosa ("babaçu"). The common opossum, Didelphis marsupialis, was the animal most frequently associated with triatomine infested palms. R. pictipes, frequently light-attracted into houses from palm trees, was the probable source of an acute case of Chagas' disease in the vicinity of Belém. It is considered that triatomine infested palms are likely to cause some cases of acute Chagas' disease in the States of Amazonas and Rondônia. Possible control methods are suggested.

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A study of the courship and copulation behaviour of Panstrongylus megistus was carried out in the laboratory. fifty-five newly-fed virgin couples were used. Experiments were performed during the day (9:00 to 12:00 a.m.) and at night (7:00 to 10:00 p.m). Behaviour was recorded by direct observation and was found to consist of the following sequence of behavioral patterns: the male approached the female and jumped on her or mounted her; he took on a dorsolateral position and immobilized the female dorsally and ventrally with his three pairs of legs; the male genital was placed below those of the female; the paramers of the male immobilized the female's genitals; copulation started. The couple joined by the iniciative of the male. The female could be receptive and accept copulation, or nonreceptive and reject the male. Copulation occurred more often on the occasion of the first attempt by the male. Duration of copulation was X = 29.3 ± 9.3 min (CV = 83%). No behavioral differences were observed couples tested during the day or at night.