Edad fisiológica de poblaciones de Lutzomyia youngi (Diptera: Psychodidae) de una área endémica de leishmaniasis cutánea

Batches of sylvatic females of Lutzomyia youngi (Phlebotominae) captured in a Shannon trap on twelve occasions over one year in a locality where subcutaneous leishmaniasis is endemic, near the city of Trujillo, Venezuela, were used to study: 1) the percentages of parous females according to previously established criteria and 2) the average number of eggs laid spontaneously by isolated females during 7 days after feeding on hamsters. The data on the batches of females captured on nights previous to the rainy period (prepluvial) were compared with those on females captured after the rains (postpluvial) . Significant differences were detected by variation analysis for two variables and different number of N, as also were consistent groupings by Duncan's Test for pre-and postpluvial lots of females. The females captured on nights prior to the rainy periods (January-March and August-September) presented higher rates of nulliparity (86-72%) and contained or laid a greater number of eggs (71-67) than those captured after the rains (March-June and November-December) which presented lower rates of nulliparity (60-24%) and a smaller number of eggs (50-30). The rainfall peaks occurred in April and September-October, respectively. It is considered that these differences can be used by epidemiological studies as a means of estimating the physiological age of female populations of L. youngy.Con lotes de hembras silvestres de Lutzomyia youngi (Phlebotominae) capturadas con trampa de Shannon en doce ocasiones a lo largo de un año, en una localidad endémica para leishmaniasis tegumentaria, próxima a la ciudad de Trujillo, Venezuela, se estudio: 1) los percentajes de hembras paridas según criterios previamente establecidos y 2) el número medio de huevos puestos espontaneamente por hembras aisladas, en el curso de 7 días postigestión, ingurgitadas también sobre hámsteres. Se comparó la data de lotes de hembras capturadas, en noches de días anteriores a los períodos de lluvias (prepluviales) con las de hembras capturadas después de las lluvias (postpluviales). Se detectó diferencias significativas por análisis de varianza para dos variables y diferente número de N, y también consistentes agrupaciones con la prueba de Duncan para lotes de hembras pre y postpluviales. Las hembras capturadas en noches previas a los periodos de lluvias (Enero - Marzo y Agosto - Septiembre) exhibieron más altas tasas de nuliparidad (86-72%) y contuvieron o eliminaron mayor número de huevos (71-67), que las hembras capturadas después de las lluvias (Marzo-Junio y Noviembre - Diciembre), con mas bajas tasas de nuliparidad (60-24%) y menores números de huevos (50-30). Los picos de lluvias ocurrieron en Abril y Septiembre - Octubre, respectivamente. Se considera que estas diferencias puedan ser utilizadas, como una estimativa de la edad fisiológica de problaciones de hembras de L. youngi, en estudios epidemiológicos

Characteristics and Optimal Design of Variable Airgap Linear Force Motors

An analytical model for predicting the characteristics of variable airgap linear force motors is developed. the model takes into account magnetic losses including the leakage and fringing effects and the reluctance existing at the contacts between permanent magnets and pole pieces. the model is validated by comparing its predicted characteristics with the results obtained from experiments and a finite element program. with the use of the modelled characteristics, computer programs based on the method of constrained steepest descent with state equations are developed for automating and optimising the design of linear force motors. Numerical studies are made for both minimisation of weight and minimisation of power consumption

ACHA: Avaliação da Contaminação hídrica por agrotóxico.

Modelos matemáticos e simuladores têm sido desenvolvidos para prever a lixiviação de agrotóxicos em solos, permitindo grande economia de tempo e recursos financeiros, além de permitir análises de risco com maior representatividade e confiabilidade. O Brasil ainda não faz uso dessas ferramentas no processo de avaliação de risco e classificação ambiental dos agrotóxicos. Estas ferramentas não são utilizadas pelas autoridades nacionais por não estarem adaptadas às condições brasileiras. O presente trabalho teve como objetivo desenvolver uma ferramenta computacional para simulação da lixiviação de agrotóxicos em cenários agrícolas brasileiros. A ferramenta computacional recebeu o nome de ACHA, que se refere ao acrônimo de Avaliação da Contaminação Hídrica por Agrotóxico. Para simulação do fluxo no solo utilizou-se a equação de Richards e para o transporte de agrotóxicos considerou-se os mecanismos de convecção, dispersão e difusão na fase líquida. A sorção do agrotóxico na fase sólida foi descrita pela isoterma de Freundlich e a degradação por uma equação de primeira ordem. O efeito dos fatores ambientais como temperatura, umidade e profundidade do solo é considerado na simulação da degradação do agrotóxico no solo. Os processos de absorção de água e agrotóxicos pelas plantas não são considerados. A ferramenta é composta de três partes: (i) código em Fortran para solução e integração dos modelos matemáticos; (ii) base de dados para armazenamento dos cenários e (iii) interface gráfica para inserção dos dados de entrada e visualização das simulações. Como resultados, a ferramenta é capaz de simular perfis de umidade e concentração do agrotóxico no solo em função do tempo.bitstream/item/29245/1/BP201058.pd

Leishmania braziliensis: aislamiento de lesiones por inoculación de hámsteres con o sin adición de lisado de glándulas salivares de Lutzomyia youngi

Homogenized biopsy tissue from the cutaneous leishmaniasis lesions of 50 patients from Trujillo, Venezuela, were inoculated subcutaneously into the tarsi of male hamsters. Homogenized tissue either alone or mixed with salivary gland lysates of Lutzomyia youngi were used for inoculation. Homogenized tissue alone yielded 58.5% of infections with a mean of twelve weeks for prepatency, while those mixed with sandfly lysate resulted in 92% of infections with a mean prepatency of three weeks.Homogeneizados de biopsias de lesiones cutáneas de 50 casos de leishmaniasis tegumentaria de Trujillo, Venezuela, han sido inoculados en hámsteres machos. Se ha comparado la infectvidad de Leishamania braziliensis, de homogeneizados simples, con la de los mezclados con lisado de glándula salival de Lutzomyia youngi, registrandose un 58,5% de infecciones para una media de 12 semanas de prepatencia con los homogeneizados simples, contra 92% de infecciones con una media de 3 semanas de prepatencia, cuando cada uno de los inóculos de homogeneizado se mezcló con lisado equivalente al de una glándula salival de flebótomo

Molecular Gas in Elliptical Galaxies: Distribution and Kinematics

I present interferometric images (approx. 7" resolution) of CO emission in five elliptical galaxies and nondetections in two others. These data double the number of elliptical galaxies whose CO emission has been fully mapped. The sample galaxies have 10^8 to 5x10^9 solar masses of molecular gas distributed in mostly symmetric rotating disks with diameters of 2 to 12 kpc. Four out of the five molecular disks show remarkable alignment with the optical major axes of their host galaxies. The molecular masses are a few percent of the total dynamical masses which are implied if the gas is on circular orbits. If the molecular gas forms stars, it will make rotationally supported stellar disks which will be very similar in character to the stellar disks now known to be present in many ellipticals. Comparison of stellar kinematics to gas kinematics in NGC 4476 implies that the molecular gas did not come from internal stellar mass loss because the specific angular momentum of the gas is about three times larger than that of the stars.Comment: 47 pages, 6 tables, 27 figures. Accepted by AJ, scheduled for August 200

Excreción de promastigotos de Leishmania pifanoi por Lutzomyia youngi experimentalmente infectada

The increase in the promastigotes population of Leishmania pifanoi in Lutzomyia youngi experimentally infected and kept on 50% sacarose under constant conditions of temperature and humidity is described. Two stages in the differentation and growth of the parasites are recognised between two and twenty-four hours after meals. The pleomorphic differentiation of the amastigotes in short promastigotes which multiply by binary division for 60 hours, when the rupture of the peritrophic membrane occurs, takes place within 48 hours. The second stage occurs between 72 and 96 hours when some of the parasites migrate to the esophagic valve and the rest of the free parasites are excreted in fecal drops as large, active promastigotes. The first drops excreted react positively to glucose or contain crystals of urate. The excess promastigotes of the second stage of development are eliminated in the last excretions and react positively to the Hemoscreen and Biuret tests for total proteins as also for glucose and account for 82% of the of drops excreted. The excretion of parasites by Lu. youngi is a normal stage in the growth of L. pifanoi into a vector.Se describe el desarrollo poblacional promastigótico de Leishmania pifanoi en Lutzomyia youngi experimentalmente infectada y mantenida con sacarosa al 50% bajo condiciones constantes de temperatura y humedad. Se reconocen dos etapas para la diferenciación y el crecimiento de los parásitos entre las dos y ciento veinte horas postprandiales. Hasta 48 horas tiene lugar la diferenciación pleomórfica de amastigotos en promastigotos cortos, que se multiplican por división binaria hasta las 60 horas, cuando ocurre la ruptura de la membrana peritrófica. La segunda etapa tiene lugar entre las 72 y 96 horas cuando algunos parásitos migran hacia la válvula esofágica y los demás parásitos libres son excretados en gotitas fecales como promastigotos grandes y activos. Las primeras gotitas excretadas dan reacción positiva a glucosa o contienen cristales de urato. El exceso de promastigotos de la segunda fase de desarrollo es eliminado en las últimas excretas que dan reacción positiva con las pruebas Hemoscreen y Biuret para proteínas totales y también para glucosa, y constituyen el 82% del total de gotas excretadas. La excreción de parásitos por Lu. youngi es fase normal del desarrollo de L. pifanoi en un vector

Lines on projective varieties and applications

The first part of this note contains a review of basic properties of the variety of lines contained in an embedded projective variety and passing through a general point. In particular we provide a detailed proof that for varieties defined by quadratic equations the base locus of the projective second fundamental form at a general point coincides, as a scheme, with the variety of lines. The second part concerns the problem of extending embedded projective manifolds, using the geometry of the variety of lines. Some applications to the case of homogeneous manifolds are included.Comment: 15 pages. One example removed; one remark and some references added; typos correcte