Características mineralógicas de uma topossequência de solos da região de São Pedro, Estado de São Paulo

Foram estudados oito pedons localizados em uma topossequência de aproximadamente 25 km de extensão, na região de São Pedro, Estado de São Paulo, indo do rio Piracicaba, na Depressão Paleozóica até o rio Jacaré-Pupira, no Planalto Ocidental. A fração argila da maioria dos solos estudados é formada principalmente por caulinita e gibbsita. Pedons localizados nas superfícies mais baixas (Pedons 1 a 5) possuem baixo teor de gibbsita (menos que 6%) enquanto que os solos localizados nas altas superfícies (Pedons 6, 7 e 8) possuem teores de gibbsita variando de 12 a 54%. Pedon 3 apresenta uma composição mineralógica diferente dos demais solos; a quantidade de minerais de grade 2:1 (mica, vermiculita e montmorilonita) é grande, com teores entre 30 e 70%. Nos demais solos o teor de minerais de grande 2:1 é baixo (menos que 80%) representado principalmente pela vermiculita. Para os solos localizados nas superfícies mais baixas existe correlação entre a mineralogia da argila e as idades das superfícies fisiográficas. Esta relação não é aparente para os solos localizados nas superfícies elevadas. A transformação de caulinita para gibbsita é observada.

Descrição de uma espécie nova de Pimelodus (Siluriformes, Pimelodidae) da bacia do alto rio Paraguai

Uma espécie nova, correntemente identificada como P. maculatus La Cepède, 1803, é descrita. Ela difere das demais espécies do gênero, exceto de P. maculatus e P. mysteriosus Azpelicueta, 1998, pelo padrão de colorido com máculas escuras sobre os flancos. A nova espécie é morfometricamente similar a P. argenteus Perugia, 1891 e P. mysteriosus, mas difere destas, respectivamente, pelo padrão de colorido maculado e pelo menor comprimento do barbilhão maxilar. Difere de P. maculatus por apresentar o processo supra-occipital mais robusto, com a base quase tão larga quanto o comprimento (versus mais comprido do que largo); narinas anteriores a 25% da margem anterior do focinho, na distância entre o início do focinho até as narinas posteriores (versus 33% dessa distância); serrilhas do acúleo peitoral mais desenvolvidas e presentes em mais da metade da margem anterior do acúleo (versus serrilhas leves e presentes em menos da metade desta margem); pele que recobre a cabeça muito fina, tornando conspícuas as estrias da superfície dos ossos; 22-27 (moda=24) rastros no primeiro arco branquial [versus 19-24 (moda=21)]. Também foi discriminado de P. maculatus na análise morfométrica multivariada das variáveis canônicas livres do tamanho, por apresentar maiores valores da distância interorbital, largura da boca e comprimento do barbilhão maxilar e menor comprimento da base da nadadeira adiposa.

Vocalização de anúncio e ampliação da distribuição de Pristimantis crepitans (Bokermann) (Amphibia, Anura, Strabomantidae)

Espécimes de Pristimantis crepitans (Bokermann, 1965) foram obtidos em áreas de afloramentos rochosos situadas na borda sudoeste do Cerrado e na borda oeste do Pantanal, próximo à fronteira entre o Brasil e a Bolívia. Indivíduos foram coletados e gravados na localidade-tipo e em outros quatro municípios, nos estados de Mato Grosso e Mato Grosso do Sul. Além da ampliação da área de ocorrência e de dados morfométricos adicionais aos da série-tipo, apresentamos pela primeira vez na literatura parâmetros da vocalização topotípica de P. crepitans, bem como fotografias de espécimes em vida e de alguns dos hábitats ocupados pelos mesmos.

Age and growth parameters of cachara Pseudoplastystoma reticulatum (Siluriformes, Pimelodidae) from the Cuiabá River, Brazil

Age and growth parameters of cachara Pseudoplatystoma reticulatum (Eigenmann & Eigenmann, 1889) (Siluriformes, Pimelodidae) (males and females) were estimated through the analysis of growth rings in spines of pectoral fins. Fish were collected from January to December 2007, in the area directly influenced by the Aproveitamento Múltiplo de Manso (APM Manso) and in the Cuiabá River (upper parts of the Pantanal). The maximum number of growth rings was seven for males, and eight, for females. The analysis of temporal variations in mean marginal increment showed that rings found in the spines were formed annually, in December. Growth rings were associated to spawning (in the study region from November to March) of the species. The growth curve in length was obtained by the von Bertalanffy model adjusted by the Ford-Walford transformation. The equations are: Ls = 72.7*[1-e-0.44(t+1.5974)] for males, and Ls = 84.5*[1-e-0.33(t+2.0943)] for females. The equations that describe the growth curve in weight are: Wt = 4991.61*[1-e-0.44 (t+1.5974] 2.70 for males and Wt = 7503.17*[1-e-0.33 (t+2.0943] 2.99 for females.

Observações sobre parasitologia humana e veterinária em Mato Grosso

The most interesting observations were: 1 - The "mal de cadeiras" (believed to be an equine trypanosomose, due to Trypanosoma equinum) is a syndrome originated from malnutrition, overwork, intense blood-loss through blood-sucking arthropods (chiefly tabanids and bot-flies) and aggravated by the conditions prevailing in the "Pantanal" region of Mato-Grosso, when the waters of the Paraguay river basin ebb, after the periodic flood. The trypanosomes act only as one more factor contributing to the horses debility. 2 - The "curso preto dos bezerros" (calves black scour), usually attributed to poly-helminthoses, was observed to be related exclusively to pure Strongyloides papillosus infestations.

Proteinase inhibitors in Brazilian leguminosae

Serine proteinase inhitors, in the seeds of several Leguminosae from the Pantanal region (West Brazil), were studied using bovine trypsin, a digestive enzyme, Factor XIIa and human plasma Kallikrein, two blood clotting factors. The inhibitors were purified from Enterolobium contortisiliquum (Mr=23,000), Torresea cearensis (Mr = 13,000), Bauhinia pentandra (Mr = 20,000) and Bauhinia bauhinioides (Mr = 20,000). E. contortisiliquum inhibitor inactivates all three enzymes, whereas the T. cearensis inhibitor inactivates trypsin and Factor XSSa, but does nor affect plasma kallikrein; both Bauhinia inhibitors, on the other hand, inactivate trypsin and plasma kallikrein but only the Bpentandra inhibitor affects Factor XIIa. Ki values were calculated between 10 [raised to the power of] -7 and 10 [raised to the power of] -8 M.

Specific antibody levels and antigenic recognition of Wistar rats inoculated with distinct isolates of Trypanosoma evansi

"Mal de Cadeiras", an enzootic disease caused by Trypanosoma evansi, is one of the most important trypanosomiases in the Brazilian Pantanal region. The disease affects mainly horses, which are widely used in extensive cattle production, an activity of greatest economical significance for the region. The parasite also infects sylvan (coatis and capybaras) and domestic (dogs) animals, respectively considered wild and domestic reservoirs of T. evansi. For a better understanding of the interaction of T. evansi with its rodent host, we evaluated the differences in the specific antibody level patterns and in the parasitic peptides recognition patterns of experimentally infected Wistar rats. The rats experimentally infected with T. evansi isolates obtained from coatis, dogs and horses were submitted to indirect immunofluorescence test (IgM e IgG) and Western blotting. The serological titers for IgM and IgG ranged between 1:40 and 1:160. The most recognized polypeptide profiles were in a range of 17 and 74 kDa. Our data suggest that the humoral immune response in Wistar rats is not sufficient for granting an effective control of T. evansi infections.

The development of an enzyme-linked immunosorbent assay for Trypanosoma vivax antibodies and its use in epidemiological surveys

There are data indicating that the distribution of Trypanosoma vivax in the Brazilian territory is expanding with potential to reach other areas, where the vectors are present. The detection of anti-trypanosomal antibodies in serum provides important information of the trypanosomal status in cattle herds. For this reason, an enzyme-linked immunosorbent assay (Tv-ELISA-Ab) with crude antigen from one Brazilian isolate of T. vivax was developed and evaluated. The sensitivity and specificity were respectively 97.6 and 96.9%. In the evaluation of cross-reactions, three calves inoculated with T. evansi trypimastigotes blood forms showed optical densities (OD) under the cut-off during the whole experimental period, except one at 45 days post-inoculation. With relation to Babesia bovis, B. bigemina, and Anaplasma marginale, which are endemic hemoparasites in the studied area, the cross-reactions were shown to be 5.7, 5.3, and 1.1%, respectively. The first serological survey of Pantanal and state of Pará showed that T. vivax is widespread, although regions within both areas had significantly different prevalences. Therefore, this Tv-ELISA-Ab may be a more appropriate test for epidemiological studies in developing countries because the diagnostic laboratories in most countries may be able to perform an ELISA, which is not true for polymerase chain reaction.

Trypanosoma (Duttonella) vivax: its biology, epidemiology, pathogenesis, and introduction in the New World - a review

The biology, epidemiology, pathogenesis, diagnostic techniques, and history of the introduction of Trypanosoma (Duttonella) vivax in the New World are reviewed. The two main immunological responses of trypanosome-infected animals - antibody production and immunodepression - are discussed in the context of how these responses play a role in disease tolerance or susceptibility. Isolation and purification of T. vivax are briefly discussed. The recent reports of bovine trypanosomiasis diagnosed in cattle on farms located in the Pantanal region of the states of Mato Grosso do Sul and Mato Grosso, Brazil, are also discussed.

Ecological niche modelling and differentiation between Rhodnius neglectus Lent, 1954 and Rhodnius nasutus Stål, 1859 (Hemiptera: Reduviidae: Triatominae) in Brazil

Ecological niche modelling was used to predict the potential geographical distribution of Rhodnius nasutus Stål and Rhodnius neglectus Lent, in Brazil and to investigate the niche divergence between these morphologically similar triatomine species. The distribution of R. neglectus covered mainly the cerrado of Central Brazil, but the prediction maps also revealed its occurrence in transitional areas within the caatinga, Pantanal and Amazon biomes. The potential distribution of R. nasutus covered the Northeastern Region of Brazil in the semi-arid caatinga and the Maranhão babaçu forests. Clear ecological niche differences between these species were observed. R. nasutus occurred more in warmer and drier areas than R. neglectus. In the principal component analysis PC1 was correlated with altitude and temperature (mainly temperature in the coldest and driest months) and PC2 with vegetation index and precipitation. The prediction maps support potential areas of co-occurrence for these species in the Maranhão babaçu forests and in caatinga/cerrado transitional areas, mainly in state of Piaui. Entomologists engaged in Chagas disease vector surveillance should be aware that R. neglectus and R. nasutus can occur in the same localities of Northeastern Brazil. Thus, the identification of bugs in these areas should be improved by applying morphometrical and/or molecular methods.

Candidatus Rickettsia andeanae, a spotted fever group agent infecting Amblyomma parvum ticks in two Brazilian biomes

Adult ticks of the species Amblyomma parvum were collected from the vegetation in the Pantanal biome (state of Mato Grosso do Sul) and from horses in the Cerrado biome (state of Piauí) in Brazil. The ticks were individually tested for rickettsial infection via polymerase chain reaction (PCR) targeting three rickettsial genes, gltA, ompA and ompB. Overall, 63.5% (40/63) and 66.7% (2/3) of A. parvum ticks from Pantanal and Cerrado, respectively, contained rickettsial DNA, which were all confirmed by DNA sequencing to be 100% identical to the corresponding fragments of the gltA, ompA and ompB genes of Candidatus Rickettsia andeanae. This report is the first to describe Ca. R. andeanae in Brazil.

Surface swimming behavior of the curculionid Ochetina uniformis Pascoe (Erirhininae, Stenopelmini) and Ludovix fasciatus (Gyllenhal) (Curculioninae, Erodiscini)

The swimming behavior exhibited by specimens of L. fasciatus and O. uniformis was analyzed frame-by-frame with video observation recorded with a digital camera, attached to a stereomicroscope. Adults of O. uniformis, an aquatic insect, swim with all three pairs of legs. During the process of swimming the majority of the abdomen and rostrum remain submerged, part of the fore and hind tibiae remain above the surface, while the mid tibiae remain submerged. The mesothoracic legs, during the power-stroke stage, provide the greatest thrust while the metathoracic legs provide the least forward propulsion. The prothoracic legs, extended forward, help to direct the swimming. The semi-aquatic specie L. fasciatus shows the same swimming style as O. uniformis, that is, with movement of all the three pairs of legs; the mesothoracic legs are responsible for the main propulsion. The insect body remains on the water surface during the process of swimming, while the legs remain submerged. Both species complete a swimming cycle in 0.33 and 0.32 seconds, respectively, with an average speed of 1.38 cm/s and a maximum and minimum swimming duration time of 11.15 and 5.05 minutes, respectively, for L. fasciatus. The swimming behavior exhibited by O. uniformis and L. fasciatus corresponds to the style known as a breast strokelike maneuver. This is the first record of this kind of swimming for both species here observed and increases to seven the number of genera of Curculionidae exhibiting this behavior.

TRATAMENTO DE EFLUENTES DE TANQUES DE PISCICULTURA APLICANDO A TECNOLOGIA DE ELETROCOAGULAÇÃO

Para a realização deste trabalho, foi utilizada a técnica da eletrocoagulação (EC) para o tratamento de efluente de piscicultura. Um reator de EC em escala de laboratório, com capacidade de 1,5 L foi montado, utilizando um conjunto de quatro placas de eletrodos de alumínio, um agitador mecânico de alto torque microprocessado, fios condutores com garras de jacaré e uma fonte de tensão com potência regulável. Os eletrodos foram arranjados dentro da célula eletrolítica de forma monopolar, em paralelo e a uma distância de 11 mm. O efluente utilizado neste estudo foi coletado em tanques de piscicultura do centro de criação de peixes do Departamento de Engenharia de Pesca da Universidade Federal do Ceará. Para a determinação da melhor condição de operação do reator, foi feito um planejamento experimental por intermédio do Software “Statgrafics”, definindo, as variáveis operacionais e os seus respetivos intervalos de variação (pH inicial de 4 a 8, condutividade de 1000 a 4000 μS cm-1, tempo de eletrolise de 15 a 35 min., agitação de 200 a 600 rpm e corrente de 1 a 2,5 A), que combinadas entre si totalizaram um total de 35 ensaios experimentais. Com base nos resultados obtidos por meio das análises físico-químicas em laboratório, pode-se afirmar que o pH inicial=8, condutividade=1000 μS cm-1, tempo=35 min., agitação=200 rpm e corrente=2,5 A, são as condições ótimas de operação do reator. Nestas condições, alcançaram remoção de 84,95% para DQO, 98,06% para nitrito, 82,43% para nitrato, 98,05% para fósforo total e 95,32% para a turbidez, sendo o custo operacional de 4,59 R$/m3 de efluente tratado. Com base nos resultados obtidos, pode-se concluir que alguns dos parâmetros analisados (pH, turbidez, temperatura, STD, nitrito, nitrato e fósforo total) estão de acordo com os padrões estabelecidos para água doce, classe 2, pela Resolução CONAMA nº 357/05, e de acordo com a Resolução CONAMA nº 430/2011 e a Portaria nº 154/2002 da SEMACE (CE), para lançamento do efluente final nos corpos receptores. A técnica de eletrocoagulação além de ser um método alternativo, eficiente e promissor para tratamento de efluentes de piscicultura, também mostrou ser ecologicamente correto por dispensar o consumo elevado de reagentes, ao contrário do que acontece no tratamento convencional.