Herpetofauna of Estação Ambiental de Peti, an Atlantic Rainforest fragment of Minas Gerais State, southeastern Brazil

Fornecemos aqui uma lista de espécies de anfíbios e répteis da Estação de Pesquisa e Desenvolvimento Ambiental de Peti, uma reserva de Mata Atlântica localizada nas montanhas da Cadeia do Espinhaço, estado de Minas Gerais, sudeste do Brasil. Essa lista originou-se de um inventário conduzido durante 78 dias de trabalhos de campo, 13 anos após a realização de um primeiro levantamento. Entre abril de 2002 e outubro de 2004, aplicamos o método de procura visual durante caminhadas nas trilhas da floresta, em diversos corpos d'água e nos sítios reprodutivos dos anuros. Foram registradas 48 espécies, incluídas nas ordens Anura (29), Gymnophiona (1), Chelonia (1), Crocodylia (1) e Squamata (16 espécies: uma anfisbena, cinco lagartos e 11 serpentes). Treze espécies não haviam sido registradas no inventário anterior, e 14 espécies registradas anteriormente não foram detectadas em nosso inventário. São discutidas possíveis explicações para as diferenças observadas. Embora nenhuma espécie esteja incluída nas listas de espécies ameaçadas do Estado de Minas Gerais e do Brasil, a reserva deve ser considerada importante para a manutenção das populações da herpetofauna local.Here we provide a list of amphibians and reptiles of Estação de Pesquisa e Desenvolvimento Ambiental de Peti, an Atlantic rainforest reserve located in the mountains of the Espinhaço Range, State of Minas Gerais, southeastern Brazil. This list originated from a 78-days inventory conducted in the area 13 years after a first inventory. We actively searched for amphibians and reptiles in forest trails and anuran breeding sites. Between April 2002 and October 2004 we recorded 48 species belonging to Anura (29 species), Gymnophiona (1), Chelonia (1), Crocodylia (1), and Squamata (16 species: one amphisbaenian, five lizards and 10 snakes). Thirteen species were not recorded in the first inventory, and 14 species previously recorded were not found in the present work. Possible explanations for these differences are discussed. Although none of the recorded species is included in the available lists of threatened species for the State of Minas Gerais and Brazil, the reserve must be considered an important source of natural habitats to the local herpetofauna.CEMI

Discrete Breathers in Two-Dimensional Anisotropic Nonlinear Schrodinger lattices

We study the structure and stability of discrete breathers (both pinned and mobile) in two-dimensional nonlinear anisotropic Schrodinger lattices. Starting from a set of identical one-dimensional systems we develop the continuation of the localized pulses from the weakly coupled regime (strongly anisotropic) to the homogeneous one (isotropic). Mobile discrete breathers are seen to be a superposition of a localized mobile core and an extended background of two-dimensional nonlinear plane waves. This structure is in agreement with previous results on onedimensional breather mobility. The study of the stability of both pinned and mobile solutions is performed using standard Floquet analysis. Regimes of quasi-collapse are found for both types of solutions, while another kind of instability (responsible for the discrete breather fission) is found for mobile solutions. The development of such instabilities is studied, examining typical trajectories on the unstable nonlinear manifold.Comment: 13 pages, 9 figure

Twistor--like Formulation of the Supermembrane in D=11 ∗^*

We propose a new formulation of the D=11 supermembrane theory that involves commuting spinors (twistor--like variables) and exhibits a manifest $n$--extended world volume supersymmetry $(1\leq n\leq 8)$. This supersymmetry replaces $n$ components of the usual $\kappa$--symmetry. We show that this formulation is classically equivalent to the standard one.Comment: 18 pages, Te

Relationship between multiple paternity and reproductive parameters for Podocnemis sextuberculata (Testudines: Podocnemididae) in the Trombetas River, Brazil

Genetic studies of multiple paternity are a valuable tool to gain information on the reproductive biology of turtles. We analyzed paternity type in Podocnemis sextuberculata and related number of fathers per nest to nesting period (beginning, middle, or end of nesting season); clutch size (number of eggs); female size; and hatchling success. Females were captured and maximum linear carapace lengths measured during the 60 days that encompass the nesting season at Rio Trombetas Biological Reserve (Pará, Brazil). Nests were marked and blood samples collected from hatchlings. Six heterologous loci were used: five from Podocnemis unifilis and one from Podocnemis expansa. Hatchlings were analyzed from 23 nests, and the rate of multiple paternity was 100%. The mean number of fathers per nest was six (± 0.9), and no significant difference between number of fathers in a nest and nesting period. Similarly there was no significant relationship between number of fathers in a nest and female size or hatchling success rate. Number of fathers was, however, positively correlated with clutch size (Spearman correlation rho = 0.47; P > 0.05). To our knowledge, this is the first study to test the relationship between multiple paternity and ecological aspects of the reproductive ecology of turtles in the genus Podocnemis. © FUNPEC-RP

Vulnerability of giant South American turtle (Podocnemis expansa) nesting habitat to climate-change-induced alterations to fluvial cycles

A change in seasonal flooding cycles in the Amazon may negatively impact nesting success of the Giant South American Turtle (Podocnemis expansa). Our aim was to devise a technique that could be replicated in the entire Amazon basin, for monitoring alterations in fluvial cycles and their effects on turtle nest mortality. We mapped the spatial distribution and height of P. expansa nests and tested the effects of different inundation scenarios within the Trombetas River Biological Reserve, Para state, Brazil. We also used historical data on water level and hatchling production to test whether the sharp decline in the Trombetas River P. expansa population over the past thirty years was related to detected changes in the flood pulse. Our models indicate that an increase of 1.5m in the water level is sufficient to decrease the time of exposure to less than the minimum required for incubation and hatching (55 days above the water) in 50% of the nesting area. This model explains the low hatchling production in dry seasons when the total nesting site exposure was less than 200 days. Since 1971, there was an average decline of 15 days per decade in sandbank exposure during the nesting season (a total of 62 days from 1971 to 2015). However, the decrease in sandbank exposure was not significantly correlated with the sharp decline in hatchling production. Changes to the water cycle in combination with the main sources of decline (overharvest, construction of dams, and dredging of riverbeds) might have an accumulative effect on P. expansa populations. © The Author(s) 2016

Simulação matemática da injeção de finos de minério de ferro pelas ventaneiras de altos fornos

Coordenação de Aperfeiçoamento de Pessoal de Nível SuperiorMuitos trabalhos têm sido desenvolvidos com o intuito de se reduzir o custo do gusa e melhorar a sua qualidade. Injeção de finos de carvão e ou minério de ferro pelas ventaneiras do alto forno, desfosforação externa, redução da temperatura de vazamento, entre outras, são algumas das técnicas utilizadas na tentativa de se obter êxito e garantir a competitividade do gusa frente a outros processos de obtenção de matéria prima para a aciaria, ou mesmo na competição do aço com sucedâneos. Neste contexto, a injeção de finos de minério de ferro vem ganhando campo, o que, além de promover um decréscimo no teor de silício do gusa, aumenta a produtividade do alto forno. O presente trabalho tem como objetivo formular o modelo matemático e simular computacionalmente este processo, bem como estudar seu comportamento térmico frente às diversas alterações operacionais, fruto dessa injeção. O modelamento foi feito a partir das equações de conservação de momentum, energia e massa, e as equações constitutivas referente aos fenômenos envolvidos, bem como suas respectivas condições de contorno. A resolução das equações do modelo matemático é feita pelo método de volumes finitos, considerando uma discretização bi-dimensional do alto forno, através do código computacional BLAST. São analisados dois casos, um sem e outro com injeção de finos de minério de ferro, como uma forma de se avaliar, preliminarmente, os resultados do modelo