Breeding Guilds Determine Frog Response to Edge Effects in Brazil’s Atlantic Forest

Understanding the response of species with differing life-history traits to habitat edges and habitat conversion helps predict their likelihood of persistence across changing landscape. In Brazil’s Atlantic Forest, we evaluated frog richness and abundance by breeding guild at four distances from the edge of a reserve: i) 200 m inside the forest, ii) 50 m inside the forest, iii) at the forest edge, and iv) 50 m inside three different converted habitats (coffee plantation, non-native Eucalyptus plantation, and abandoned pastures, hereafter matrix types). By sampling a dry and a wet season, we recorded 622 individual frogs representing 29 species, of which three were undescribed. Breeding guild (i.e. bromeliad, leaf-litter, and water-body breeders) was the most important variable explaining frog distributions in relation to edge effects and matrix types. Leaf-litter and bromeliad breeders decreased in richness and abundance from the forest interior toward the matrix habitats. Water-body breeders increased in richness toward the matrix and remained relatively stable in abundance across distances. Number of large trees (i.e. DBH \u3e 15 cm) and bromeliads best explained frog richness and abundance across distances. Twenty species found in the interior of the forest were not found in any matrix habitat. Richness and abundance across breeding guilds were higher in the rainy season but frog distributions were similar across the four distances in the two seasons. Across matrix types, leaf-litter species primarily used Eucalyptus plantations, whereas water-body species primarily used coffee plantations. Bromeliad breeders were not found inside any matrix habitat. Our study highlights the importance of primary forest for bromeliad and leaf-litter breeders. We propose that water-body breeders use edge and matrix habitats to reach breeding habitats along the valleys. Including life-history characteristics, such as breeding guild, can improve predictions of frog distributions in response to edge effect and matrix types, and can guide more effective management and conservation actions

Effectiveness of Surgery for Lumbar Spinal Stenosis : A Systematic Review and Meta-Analysis

Peer reviewedPublisher PD

Transport Properties of Highly Aligned Polymer Light-Emitting-Diodes

We investigate hole transport in polymer light-emitting-diodes in which the emissive layer is made of liquid-crystalline polymer chains aligned perpendicular to the direction of transport. Calculations of the current as a function of time via a random-walk model show excellent qualitative agreement with experiments conducted on electroluminescent polyfluorene demonstrating non-dispersive hole transport. The current exhibits a constant plateau as the charge carriers move with a time-independent drift velocity, followed by a long tail when they reach the collecting electrode. Variation of the parameters within the model allows the investigation of the transition from non-dispersive to dispersive transport in highly aligned polymers. It turns out that large inter-chain hopping is required for non-dispersive hole transport and that structural disorder obstructs the propagation of holes through the polymer film.Comment: 4 pages, 5 figure

Maximum level and time to peak of dam-break waves on mobile horizontal bed

Journal of Hydraulic Engineering, Vol. 135, No. 11, November 1, 2009This experimental study focuses the influence of bed material mobility and initial downstream water level on maximum water level and time to peak of dam-break waves. It covers horizontal bed conditions on fixed bed, sand bed, and pumice bed. Results include water surface level time evolution, maxima wave levels and time to peak. The influence of bed material mobility and downstream water level was identified and characterized, stressing the importance of using mathematical models with appropriate sediment transport formulations instead of purely hydrodynamic models to simulate dam-break waves on mobile bed channels

Exportação de nutrientes em povoamentos de Pinus taeda L. baseada em volume estimado pelo sistema sispinus.

Os plantios de Pinus ocorrem preferencialmente em regiões com menores preços de terras, localizados em áreas com solos de baixa fertilidade natural e conseqüentemente baixa produtividade. Essa condição, associada ao fato da não-fertilização dos plantios, via de regra, e à exportação de nutrientes nos desbastes e na colheita final, leva invariavelmente a perdas de produtividade futuras dos povoamentos. Nesse contexto, este trabalho teve como objetivo avaliar a aplicabilidade de modelos matemáticos, desenvolvidos em área florestais descritas por Moro (2005), ao SisPinus, para estimativa de nutrientes exportados na madeira, nas ocasiões da colheita da floresta. Para a realização deste estudo, foram selecionados plantios de P. taeda com 8, 12, 18 e 23 anos de idade, localizados em povoamentos comerciais, situados na região de Guarapuava (PR). Determinaram-se os nutrientes nos diversos segmentos do tronco, a cada metro, da base à altura comercial, no lenho e na casca. As equações desenvolvidas por Moro (2005) foram inseridas ao estimador de biomassa SisPinus, possibilitando a estimativa dos nutrientes exportados. O ajuste das equações desenvolvidas, dentro da variação de idade, qualidade do sítio, intensidade de manejo, entre outras variáveis, foi extremamente elevado, permitindo alta confiabilidade nas equações para estimativa de exportação dos nutrientes

Critical region of the random bond Ising model

We describe results of the cluster algorithm Special Purpose Processor simulations of the 2D Ising model with impurity bonds. Use of large lattices, with the number of spins up to $10^6$, permitted to define critical region of temperatures, where both finite size corrections and corrections to scaling are small. High accuracy data unambiguously show increase of magnetization and magnetic susceptibility effective exponents $\beta$ and $\gamma$, caused by impurities. The $M$ and $\chi$ singularities became more sharp, while the specific heat singularity is smoothed. The specific heat is found to be in a good agreement with Dotsenko-Dotsenko theoretical predictions in the whole critical range of temperatures.Comment: 11 pages, 16 figures (674 KB) by request to authors: [email protected] or [email protected], LITP-94/CP-0

Scattering of Dirac particles from non-local separable potentials: the eigenchannel approach

An application of the new formulation of the eigenchannel method [R. Szmytkowski, Ann. Phys. (N.Y.) {\bf 311}, 503 (2004)] to quantum scattering of Dirac particles from non-local separable potentials is presented. Eigenchannel vectors, related directly to eigenchannels, are defined as eigenvectors of a certain weighted eigenvalue problem. Moreover, negative cotangents of eigenphase-shifts are introduced as eigenvalues of that spectral problem. Eigenchannel spinor as well as bispinor harmonics are expressed throughout the eigenchannel vectors. Finally, the expressions for the bispinor as well as matrix scattering amplitudes and total cross section are derived in terms of eigenchannels and eigenphase-shifts. An illustrative example is also provided.Comment: Revtex, 9 pages, 4 figures, published versio

Comportamento de cultivares de café com resistência à ferrugem-do-cafeeiro no Sul do Estado de Minas Gerais.

Nos últimos anos foram liberadas para plantio comercial diversas cultivares de café arábica resistentes à ferrugem, porém muitas dessas cultivares ainda não foram testadas em várias regiões cafeeiras do Brasil, incluindo o sul de Minas Gerais. A região sul do estado de Minas Gerais possui um parque cafeeiro de cerca de 500.000 ha, abrangendo uma área com grande variação edafoclimática e diversidade de sistemas de cultivo. Essas características influenciam sobremaneira no comportamento agronômico das cultivares de café plantadas na região, haja vishttp://ainfo.cnptia.embrapa.br/ainfo/pages/ainfo/save/documentoSave.facesta que a produtividade do cafeeiro está diretamente relacionada com a interação genótipo ambiente. Em janeiro de 2006 foi instalado um ensaio com 30 cultivares resistentes à ferrugem, no Município de Varginha, MG, a 1000 m de altitude, onde foram avaliadas as três primeiras produções (2008 a 2010), a resistência à ferrugem e a qualidade dos grãos. As cultivares Sabiá Tardio, IPR 100, Palma II, Acauã, IPR 99, IPR 103, Catuaí amarelo IAC 62, Catucaí Amarelo 20/15 cv 479 e Catucaí amarelo 24/137 produziram significativamente mais que as demais. Foram encontradas lesões de ferrugem em todas as plantas das cultivares do grupo Catucaí e nas cultivares IPR 100 e IPR 103. Observaram-se também plantas suscetíveis nas cultivares Oeiras (70%) e Sabiá Tardio (12,5%) e nas progênies Paraíso 419-3-3-7-16-4-1 (12,5%) e Paraíso 419-10-6-2-12-1 (28,6%). Por outro lado, nas progênies Paraíso 419-10-6-2-10-1 e Paraíso 419-10-6-2-5-1 todas as plantas foram classificadas como altamente resistentes. Catuaí Vermelho IAC 144, Catuaí Amarelo IAC 62 e Bourbon Amarelo, incluídas como referência de suscetibilidade, 100% das plantas apresentaram pústulas de ferrugem. A classificação dos grãos mediante peneira revelou que, em média, as cultivares apresentaram 49,3% dos grãos retidos na peneira 17 ou acima. Araponga MG1 e IPR99 destacaram-se das demais com, respectivamente, 73,5% e 76,0% de grãos nas peneiras 17 e acima