The taxonomic and phylogenetic relationships of Trypanosoma vivax from South America and Africa

The taxonomic and phylogenetic relationships of Trypanosoma vivax are controversial. It is generally suggested that South American, and East and West African isolates could be classified as subspecies or species allied to T. vivax. This is the first phylogenetic study to compare South American isolates (Brazil and Venezuela) with West/East African T. vivax isolates. Phylogeny using ribosomal sequences positioned all T. vivax isolates tightly together on the periphery of the clade containing all Salivarian trypanosomes. The same branching of isolates within T. vivax clade was observed in all inferred phylogenies using different data sets of sequences (SSU, SSU plus 5.8S or whole ITS rDNA). T. vivax from Brazil, Venezuela and West Africa (Nigeria) were closely related corroborating the West African origin of South American T. vivax, whereas a large genetic distance separated these isolates from the East African isolate (Kenya) analysed. Brazilian isolates from cattle asymptomatic or showing distinct pathology were highly homogeneous. This study did not disclose significant polymorphism to separate West African and South American isolates into different species/subspecies and indicate that the complexity of T. vivax in Africa and of the whole subgenus Trypanosoma (Duttonella) might be higher than previously believed. © 2006 Cambridge University Press.

Abnormal evening vertical plasma drift and effects on ESF and EIA over Brazil-South Atlantic sector during the 30 October 2003 superstorm

Equatorial F region vertical plasma drifts, spread F and anomaly responses, in the south American longitude sector during the superstorm of 30 October 2003, are analyzed using data from an array of instruments consisting of Digisondes, a VHF radar, GPS TEC and scintillation receivers in Brazil, and a Digisonde and a magnetometer in Jicamarca, Peru. Prompt penetrating eastward electric field of abnormally large intensity drove the F layer plasma up at a velocity ∼1200 ms -1 during post dusk hours in the eastern sector over Brazil. The equatorial anomaly was intensified and expanded poleward while the development of spread F/plasma bubble irregularities and GPS signal scintillations were weaker than their quiet time intensity. Significantly weaker F region response over Jicamarca presented a striking difference in the intensity of prompt penetration electric field between Peru and eastern longitudes of Brazil. The enhanced post dusk sector vertical drift over Brazil is attributed to electro-dynamics effects arising energetic particle precipitation in the South Atlantic Magnetic Anomaly (SAMA). These extraordinary results and their longitudinal differences are presented and discussed in this paper. Copyright 2008 by the American Geophysical Union.

Comportamento reprodutivo e cooperação no ciclídeo neotropical Laetacara sp

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

O Brasil e a política estratégica dos Estados Unidos: o fim da Guerra Fria : hemisfério Ocidental, América Latina e as Relações Brasil-Estados Unidos

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Impacts of Reproductive Technologies on Beef Production in South America

The majority of beef cow herds in South America are constituted by Bos indicus females, which have particular reproductive features that contribute to reduced reproductive efficiency compared with that of B. taurus cohorts. Hence, several alternatives to enhance reproductive efficiency of B. indicus heifers and cows have been developed to address their inherent reproductive shortcomings. These research-based technologies are being described in detail within this chapter and have already made an impact on South American B. indicus-based production systems. These include the following: (a) hormonal protocols to induce puberty in nulliparous heifers or estrous cyclicity in postpartum cows to maximize their reproductive performance during the subsequent breeding season, (b) hormonal protocols to synchronize estrus and/or ovulation in B. indicus females to exploit their reproductive responses to artificial insemination, and (c) genetic and environmental factors that influence reproductive success in beef herds, including reproductive diseases and excitable temperament of B. indicus females, that have been investigated to support/promote the development of appropriate mitigation technologies.

Sustainable worm control practices in South America

A high prevalence of nematodes, especially Haemonchus contortus and Trichostrongylus colubriformis, that exhibit multiple anthelmintics resistance has been reported in sheep in several South American countries. For this reason, the development of strategies that are less dependent on anthelmintic treatments is imperative for the prophylaxis of gastrointestinal nematode infections in small ruminants. Integrated grazing using cattle and sheep can be used for pasture decontamination with considerable reduction of H. contortus and T. colubnformis infective larvae after cattle grazing. Several breeds of sheep exhibit genetically related resistance against nematode infections, as is the case of crioulo, native or naturalised breeds of sheep. These breeds descend from livestock introduced by Portuguese and Spanish settlers and have been submitted to a long process of natural selection in various environmental conditions. In the South, the Crioula Lanada breed is more resistant to H. contortus than are Corriedale sheep. In tropical areas, where the minimum temperatures are usually higher than 20 degrees C, hair sheep flourish, especially the Santa Ines breed, which also display a higher level of resistance to nematode infections compared with certain breeds of European origin. However, Santa Ines sheep have inferior carcass quality compared with other commercial breeds. Recent studies showed that the crossbreeding of Santa Ines ewes with sires of breeds with high potential for growth and meat production, results in crossbred animals with high productivity and a satisfactory degree of resistance against nematode infections. Several studies have indicated that improvement in nutrition has a beneficial effect on the development of resistance in lambs that were naturally or artificially infected with nematodes. Therefore, supplementary feeding and breeding strategies to improve resistance to nematodes are feasible options in the effort to reduce dependence on anthelmintic drugs to control worm infections in sheep. (C) 2013 Elsevier B.V. All rights reserved.

Spatial Variation in Morphometry in Vanzosaura rubricauda (Squamata, Gymnophthalmidae) from Open Habitats of South America and its Environmental Correlates

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Checklist of Helminth parasites of Amphibians from South America

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

Five new species of the feather mite genus Trouessartia Canestrini from South America (Acari: Trouessartiidae)

Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)

Subtropical Cyclones over the Southwestern South Atlantic: Climatological Aspects and Case Study

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

El nuevo regionalismo y el Consejo de Defensa Suramericano

Pós-graduação em Relações Internacionais (UNESP - UNICAMP - PUC-SP) - FFC

A emergência do conceito da interculturalidade no ensino e aprendizagem de língua estrangeira

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

Taxonomic review of the species of Mugil (Teleostei: Perciformes: Mugilidae) from the Atlantic South Caribbean and South America, with integration of morphological, cytogenetic and molecular data

Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq)

A segurança através do espelho convexo das Américas: percepções, imagens e interesses na conformação de uma identidade

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)

A política externa estadunidense no atual quadro político sul-americano

The central thesis that we aim to survey in this paper is that the present South-American political scene has required of the American imperialism a strategical redesign, in the sense of the neutralization, weakening and, if it is possible, destruction of regional political experiences/tendencies not aligned to its foreign politics. Under the mask of the defense of democracy and beneath the argument that Latin American "market oriented politics" are at stake, due to questions that goes back from the "delin-quency" —in Mexico—, the global terrorism, the organized international crime up to the worldwide drug traffic, the global strategy of American imperialism then sets up the definition of a new doctrine of preventive war that justifies the utilization of hard power against any country, in the name of its own defense. At the heart of the question what —actually— is in the agenda is the defense (and reproduction) of the benefits of its multinationals corporations and financial capital, by means of the international sub-traction of profitable assets, such as financial, energetic, communicational and natural resources, in addition to the domination of local markets, beyond facilitating capital flee amongst others.