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Search Results: 1 - 10 of 224458 matches for " Mauricio C. Horta "
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Infección por rickettsia en capibaras (Hydrochoerus hydrochaeris) de S o Paulo, Brasil: evidencia serológica de infección por Rickettsia bellii y Rickettsia parkeri Rickettsial infection in capybaras (Hydrochoerus hydrochaeris from S o Paulo, Brazil: serological evidence for infection by Rickettsia bellii and Rickettsia parkeri
Richard C. Pacheco,Mauricio C. Horta,Jonas Moraes-Filho,Alexandre C. Ataliba
Biomédica , 2007,
Abstract: Introducción. En Brasil, los capibaras (Hydrochoerus hydrochaeris) son importantes huéspedes para garrapatas del género Amblyomma, las cuales transmiten rickettsiosis a humanos y animales. Por lo tanto, estos roedores pueden ser potenciales centinelas para detectar infección por rickettsia. Objetivos. Este trabajo evaluó la infección por rickettsia en capibaras de diferentes regiones del estado de S o Paulo, donde las rickettsiosis nunca han sido reportadas. Materiales y métodos. Se examinarion los sueros de 73 capibaras de seis localidades en S o Paulo con la prueba de immunofluorescencia indirecta con antígenos de Rickettsia rickettsii, Rickettsia parkeri y Rickettsia bellii. Los bazos de los capibaras se extrajeron y se analizaron por reacción en cadena de la polimerasa para un fragmento del gene gltA de rickettsia. Las garrapatas se recolectaron de los capibaras y se identificaron hasta especie. Resultados. Diecinueve (26,0%), 25 (34,2%) y 50 (68,5%) sueros de los capibaras reaccionaron con R. rickettsii, R. parkeri y R. bellii, respectivamente. De los 50 sueros que reaccionaron con antígenos de R. bellii, 25 presentaron títulos, por lo menos, cuatro veces mayores que los otros dos antígenos. Estos sueros fueron considerados homólogos de R. bellii. Usando el mismo criterio, tres sueros de los capibaras se consideraron homólogos de R. parkeri. Ningún suero se consideró homólogo de R. rickettsii. No se detectó ADN de rickettsia en bazo. Las garrapatas recolectadas de los capibaras fueron identificadas como Amblyomma dubitatum y Amblyomma cajennense. Conclusiones. Este trabajo reporta la primera evidencia de infección natural por R. bellii en vertebrados y, también, la primera evidencia de infección por R. parkeri en capibaras. Se sabe que R. parkeri infecta y produce enfermedad en humanos; sin embargo, no hay evidencia de infección humana por R. bellii. Introduction. In Brazil, capybaras (Hydrochoerus hydrochaeris) are important hosts for Amblyomma ticks, which in turn can transmit rickettsiae to humans and animals. Therefore, capybaras are potential sentinels for rickettsial infection. Objective. The present study evaluated rickettsial infection in capybaras in different areas of the state of S o Paulo, where rickettsiosis has never been reported. Materials and methods. Blood sera from 73 capybaras from six localities in S o Paulo were tested by indirect immunofluorescence assay using Rickettsia rickettsii, Rickettsia parkeri, and Rickettsia bellii antigens. Capybara spleens were tested by PCR, targeting a fragment of the rickettsial gltA gene. Ticks
Rickettsial infection in capybaras (Hydrochoerus hydrochaeris) from S?o Paulo, Brazil: serological evidence for infection by Rickettsia bellii and Rickettsia parkeri
Pacheco,Richard C; Horta,Mauricio C; Moraes-Filho,Jonas; Ataliba,Alexandre C; Pinter,Adriano; Labruna,Marcelo B;
Biomédica , 2007,
Abstract: introduction. in brazil, capybaras (hydrochoerus hydrochaeris) are important hosts for amblyomma ticks, which in turn can transmit rickettsiae to humans and animals. therefore, capybaras are potential sentinels for rickettsial infection. objective. the present study evaluated rickettsial infection in capybaras in different areas of the state of s?o paulo, where rickettsiosis has never been reported. materials and methods. blood sera from 73 capybaras from six localities in s?o paulo were tested by indirect immunofluorescence assay using rickettsia rickettsii, rickettsia parkeri, and rickettsia bellii antigens. capybara spleens were tested by pcr, targeting a fragment of the rickettsial glta gene. ticks were collected from each capybara sample and taxonomically identified to species. results. a total of 94 positively reacting capybara samples, 19 (26.0%), 25 (34.2%), and 50 (68.5%) capybara sera reacted to r. rickettsii, r. parkeri, and r. bellii, respectively. twenty-five capybara sera showed titers to r. bellii at least four-fold higher than to any of the other two antigens. these sera were considered homologous to r. bellii. using the same criteria, 3 capybara sera were considered homologous to r. parkeri. no sera were be considered homologous to r. rickettsii. no rickettsial dna was detected in capybara spleen samples. ticks collected on capybaras were amblyomma dubitatum and amblyomma cajennense. conclusions. the first evidence is reported of r. bellii natural infection in vertebrate hosts, and the first evidence of r. parkeri infection in capybaras. while r. parkeri is known to infect and cause disease in humans, no similar evidence for human infection has been indicated by r. bellii.
Rickettsia felis infection in cat fleas Ctenocephalides felis felis
Horta, Mauricio C.;Scott, Fabio B.;Correia, Thaís R.;Fernandes, Julio I.;Richtzenhain, Leonardo J.;Labruna, Marcelo B.;
Brazilian Journal of Microbiology , 2010, DOI: 10.1590/S1517-83822010000300035
Abstract: the present study evaluated the rickettsial infection in a laboratory colony of cat fleas, ctenocephalides felis felis (bouche) in brazil. all flea samples (30 eggs, 30 larvae, 30 cocoons, 30 males, and 30 females) tested by polymerase chain reaction (pcr) were shown to contain rickettsial dna. pcr products, corresponding to the rickettsial glta, htra, ompa and ompb gene partial sequences were sequenced and showed to correspond to rickettsia felis, indicating that the flea colony was 100% infected by r. felis. the immunofluorescence assay (ifa) showed the presence of r. felis-reactive antibodies in blood sera of 7 (87.5%) out of 8 cats that were regularly used to feed the flea colony. from 15 humans that used to work with the flea colony in the laboratory, 6 (40.0%) reacted positively to r. felis by ifa. reactive feline and human sera showed low endpoint titers against r. felis, varying from 64 to 256. with the exception of one human serum, all r. felis-reactive sera were also reactive to rickettsia rickettsii and/or rickettsia parkeri antigens at similar titers to r. felis. the single human serum that was reactive solely to r. felis had an endpoint titer of 256, indicating that this person was infected by r. felis.
Influencia de los Parámetros de Carga en la Estabilidad Direccional de un Vehículo Combinado
Horta,Juan C; Canale,Ant?nio C;
Información tecnológica , 2009, DOI: 10.4067/S0718-07642009000400015
Abstract: this work is about the directional stability of truck-semitrailer vehicle, commonly used in brazil, as a function of load parameters. for different positions of centre of gravity of semi-trailer, the curves that represent the characteristic movements and the ratio of damping for these movements during curved and straight trajectories are obtained. the influence of load and moment inertia variations for different adopted positions of the centre of gravity of semi-trailer was calculated. the results show significant changes on dynamic response of vehicle with the variations of load parameters. thus, the operating conditions with less safety margins were determined, so they can be avoided by users. the study allows concluding that there are load conditions that although being accepted by the present legislation, must be avoided.
Influencia de los Parámetros de Carga en la Estabilidad Direccional de un Vehículo Combinado The Influence of Parameters of Load in the Directional Stability of Articulated Heavy Vehicle
Juan C Horta,Ant?nio C Canale
Información Tecnológica , 2009,
Abstract: En este trabajo se estudia la estabilidad direccional de un vehículo comercial combinado camión-tractor semi-remolque (muy utilizado en Brasil), como función de los parámetros de carga. Para diferentes posiciones del centro de gravedad del conjunto semi-remolque-carga, se obtuvo las curvas que representan los movimientos característicos del vehículo en respuesta a la acción de una perturbación externa. Se calculó también, los factores de amortiguación para estos movimientos durante trayectorias curvas y rectas. Se estudió la influencia de la variación de la carga y del momento de inercia del semi-remolque para las diferentes posiciones del centro de gravedad adoptadas. Los resultados indican cambios significativos en la respuesta dinámica del vehículo con la variación de los parámetros de carga. Se determinó así las condiciones operacionales con menor margen de seguridad para que puedan ser evitadas por los usuarios. Se concluye que existen condiciones de carga que, aunque permitidas por la legislación vigente, deben ser evitadas. This work is about the directional stability of truck-semitrailer vehicle, commonly used in Brazil, as a function of load parameters. For different positions of centre of gravity of semi-trailer, the curves that represent the characteristic movements and the ratio of damping for these movements during curved and straight trajectories are obtained. The influence of load and moment inertia variations for different adopted positions of the centre of gravity of semi-trailer was calculated. The results show significant changes on dynamic response of vehicle with the variations of load parameters. Thus, the operating conditions with less safety margins were determined, so they can be avoided by users. The study allows concluding that there are load conditions that although being accepted by the present legislation, must be avoided.
Natural and human impacts on invertebrate communities in Brazilian caves
FERREIRA, R. L.;HORTA, L. C. S.;
Revista Brasileira de Biologia , 2001, DOI: 10.1590/S0034-71082001000100003
Abstract: species richness, abundance, distribution and similairity between cave invertebrate communities were compared among seven caves located in the perua?u river valley, north of minas gerais state, brazil. such comparisons aimed to determinate the degree of biological complexity in the sampled caves, calculated by the "index of biological complexity in caves", presented in this manuscript. the presence of potencial or real impacts on the cave fauna was also investigated. a total of 1,468 individuals belonging to 57 families of: acarina, pseudoscorpionida, araneida, opilionida, amblypygi, isopoda, geophilomorpha, scutigeromorpha, spirostreptida, coleoptera, collembola, diptera, dictyoptera, ephemeroptera, ensifera, heteroptera, hymenoptera, lepidoptera, plecoptera, psocoptera, and trichoptera was collected. caves with higher resource availability (as those hidrologicaly actives) had a higher biological complexity than those with less resource. there are two types of impacts that occur in the area: the natural (geological) and the anthropic, as intense "stepping" and visitation or use of cave entrances as cattle shelters. there are caves with different preservation degrees in the area, with invertebrate communities in varied complexity states. the communities of these caves undoubtedly deserve care, since the area is extremely important in the brazilian biospeleological context.
Some Delesseriaceae (Ceramiales, Rhodophyta) new to the southwestern Atlantic
HORTA, PAULO A.;OLIVEIRA, EURICO C.;
Brazilian Journal of Botany , 2001, DOI: 10.1590/S0100-84042001000400011
Abstract: up to now 18 species of delesseriaceae have been referred to the brazilian coast, nine of which belong to the subfamily delesserioideae. here we report for the first time the occurrence of apoglossum gregarium (dawson) wynne, branchioglossum minutum schneider and hypoglossum anomalum wynne & ballantine collected by scuba diving on islands of the south and southeastern coast of brazil. this report is an indication that the subtidal has been undersampled on the southwestern atlantic.
Natural and human impacts on invertebrate communities in Brazilian caves
FERREIRA R. L.,HORTA L. C. S.
Revista Brasileira de Biologia , 2001,
Abstract: Species richness, abundance, distribution and similairity between cave invertebrate communities were compared among seven caves located in the Perua u River valley, north of Minas Gerais State, Brazil. Such comparisons aimed to determinate the degree of biological complexity in the sampled caves, calculated by the "Index of Biological Complexity in Caves", presented in this manuscript. The presence of potencial or real impacts on the cave fauna was also investigated. A total of 1,468 individuals belonging to 57 families of: Acarina, Pseudoscorpionida, Araneida, Opilionida, Amblypygi, Isopoda, Geophilomorpha, Scutigeromorpha, Spirostreptida, Coleoptera, Collembola, Diptera, Dictyoptera, Ephemeroptera, Ensifera, Heteroptera, Hymenoptera, Lepidoptera, Plecoptera, Psocoptera, and Trichoptera was collected. Caves with higher resource availability (as those hidrologicaly actives) had a higher biological complexity than those with less resource. There are two types of impacts that occur in the area: the natural (geological) and the anthropic, as intense "stepping" and visitation or use of cave entrances as cattle shelters. There are caves with different preservation degrees in the area, with invertebrate communities in varied complexity states. The communities of these caves undoubtedly deserve care, since the area is extremely important in the Brazilian biospeleological context.
Some Delesseriaceae (Ceramiales, Rhodophyta) new to the southwestern Atlantic
HORTA PAULO A.,OLIVEIRA EURICO C.
Brazilian Journal of Botany , 2001,
Abstract: Up to now 18 species of Delesseriaceae have been referred to the Brazilian coast, nine of which belong to the subfamily Delesserioideae. Here we report for the first time the occurrence of Apoglossum gregarium (Dawson) Wynne, Branchioglossum minutum Schneider and Hypoglossum anomalum Wynne & Ballantine collected by SCUBA diving on islands of the south and southeastern coast of Brazil. This report is an indication that the subtidal has been undersampled on the southwestern Atlantic.
Entre ipês e eucaliptos
Regina Horta Duarte,Natascha Stefania C. Ostos
Nómadas , 2005,
Abstract: El presente trabajo enfoca los eventos, prácticas y discursos en torno a las celebraciones del Día del árbol entre el comienzo del siglo XX y la década de 1970, explorando los diferentes significados atribuidos al evento, en distintos momentos históricos de la sociedad brasile a. Para tanto, privilegiará un estudio de caso, la ciudad brasile a de Belo Horizonte, idealizada desde su construcción, en 1897, como “ciudad jardín”.
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