Mucuna tapantiana (Fabaceae: Faboideae: Phaseoleae), a new species from Costa Rica

A new species of Mucuna (Fabaceae: Faboideae: Phaseoleae), endemic to Costa Rica, is described and illustrated. Mucuna tapantiana is distinguished by its small, essentially glabrous leaflets, conspicuous filiform peduncle and pedicels, inflorescences with few green or yellowish-green flowers; fruits with softly villous, yellowish or brownish pubescence on the outer surface (when fresh), but without urticating trichomes, turning dark brown or blackish when dry, 1 - 2-seeded; seeds oblong and laterally compressed691COORDENAÇÃO DE APERFEIÇOAMENTO DE PESSOAL DE NÍVEL SUPERIOR - CAPESMissouri Botanical Garden; Universidad Estadual at Campina

Bloch-like oscillations in a one-dimensional lattice with long-range correlated disorder

We study the dynamics of an electron subjected to a uniform electric field within a tight-binding model with long-range-correlated diagonal disorder. The random distribution of site energies is assumed to have a power spectrum $S(k) \sim 1/k^{\alpha}$ with $\alpha > 0$. Moura and Lyra [Phys. Rev. Lett. {\bf 81}, 3735 (1998)] predicted that this model supports a phase of delocalized states at the band center, separated from localized states by two mobility edges, provided $\alpha > 2$. We find clear signatures of Bloch-like oscillations of an initial Gaussian wave packet between the two mobility edges and determine the bandwidth of extended states, in perfect agreement with the zero-field prediction.Comment: 4 pages, 5 figure

High Levels of Chromosomal Differentiation in Euchroma gigantea L. 1735 (Coleoptera, Buprestidae)

Euchroma giganteawas karyotypically studied using conventional staining, C-banding, silver nitrate staining and ribosomal fluorescent in situ hybridization (rDNA FISH). Broad wide autosomal polymorphism and a complex sex determination system were found in this beetle. Karyotype complements ranging from 2n = 32, X1X2X3Y1Y2Y3 to 2n = 36,X1X2X3Y1Y2Y3 were detected in the sample analyzed. Punctiform suernumerary chromosomes were present in the different karyotypes. The karyotypic evolution of Brazilian E. giganteamay have taken two directions, reduction in the diploid number of 2n = 36 to 24 through centric fusions or 2n = 24 to 36 due to chromosomal fissions. In addition, pericentric inversions were also involved. The complex multiple sex mechanism of this species seems to be old and well established since it is found in specimens from different populations. Small pericentromeric blocks of constitutive heterochromatin were located on the autosomes and terminal blocks were also found on some small pairs. The sex chromosomes showed larger constitutive heterochromatin blocks. Silver nitrate staining during prophase I of meiosis showed labeling of the sex chromosome chain. However, the rDNA sites could only be precisely determined by FISH, which permitted the identification of these ribosomal sites on chromosomes X1 and X2 of this species

Delocalization and wave-packet dynamics in one-dimensional diluted Anderson models

We study the nature of one-electron eigen-states in a one-dimensional diluted Anderson model where every Anderson impurity is diluted by a periodic function $f(l)$ . Using renormalization group and transfer matrix techniques, we provide accurate estimates of the extended states which appear in this model, whose number depends on the symmetry of the diluting function $f(l)$. The density of states (DOS) for this model is also numerically obtained and its main features are related to the symmetries of the diluting function $f(l)$. Further, we show that the emergence of extended states promotes a sub-diffusive spread of an initially localized wave-packet.Comment: 6 pages, 6 figures, to appear in EPJ

Seleção de marcadores RAPD para análise genética em germoplasma de tucumã-do-pará (Astrocaryum vulgare Mart.).

O tucumã-do-pará é palmeira perene, oleaginosa, de caule múltiplo, indicada como uma das alternativas de matéria prima ao mercado de biodiesel. Marcadores RAPD são úteis em análises genéticas de espécies pouco estudadas, como o tucumã. O objetivo deste trabalho foi selecionar marcadores RAPD polimórficos para análises genéticas dessa palmeira. Foram testados 116 primers RAPD em cinco genótipos do Banco de Germoplasma da Embrapa Amazônia Oriental, Belém-PA. Foram selecionados 24 primers que amplificaram bandas nítidas e polimórficas. A matriz binária foi gerada para análises do número ótimo de bandas, pelo método bootstrap e da similaridade genética. O número de bandas adequado para a genotipagem foi de 130. Logo, os 24 marcadores são úteis para expressar a variabilidade e a divergência genética em germoplasma dessa espécie

Variabilidade e divergência genética entre genótipos de tucumanzeiro-do-pará (Astrocaryum vulgare Mart.) promissores para a produção de frutos por marcadores rapd.

O objetivo deste trabalho foi estimar a variabilidade e a divergência genética entre genótipos de tucumanzeiro-do-pará promissores para a produção de frutos por marcadores de RAPD. Foram coletadas amostras de folhas de 29 plantas-matrizes selecionadas no Banco Ativo de Germoplasma da Embrapa Amazônia Oriental, com base na produção de frutos por planta, mas com pronunciadas variações para outras características. As amostras de DNA foram amplificadas por 24 iniciadores RAPD e analisadas por três métodos multivariados, usando a matriz de dissimilaridades genéticas obtidas pelo complemento aritmético do coeficiente de Jaccard. Foram gerados 332 marcadores moleculares que expressaram 98,5% de polimorfismo. Os marcadores RAPD apresentaram poder de discriminação eficiente entre os 29 genótipos avaliados, constatando-se distância genética média entre os genótipos de 51,7%, variando entre 26,9% e 71,5%. A maior média de distância ocorreu entre o genótipo 22 e os demais, com 66,8%. Os genótipos formaram oito e quinze grupos distintos, possivelmente grupos heteróticos, pelos métodos de agrupamentos UPGMA e Tocher, respectivamente. As análises das coordenadas principais confirmaram a alta variabilidade entre os genótipos. Os marcadores moleculares utilizados permitiram a identificação de ampla variabilidade e forte divergência genética entre os genótipos com ausência de duplicatas, o que possibilita a indicação desses materiais para compor programa de melhoramento genético para a produção de frutos

6Li direct breakup lifetimes

alpha-d coincidence data were studied for the 6Li + 59Co reaction at E(lab) = 29.6 MeV. By using a kinematic analysis, it was possible to identify which process, leading to the same final state, has the major contribution for each of the selected angular regions. Contributions of the 6Li sequential and direct breakup to the incomplete fusion/transfer process were discussed by considering the lifetimes obtained by using a semiclassical approach, for both breakup components.Comment: 5 pages, 4 figures, Invited Talk (Parrallel Sessions) of A. Szanto de Toledo, prepared for the Proccedings of the 10th International Conference on Nucleus-Nucleus Collisions, August 16-21, 2009, Beijing, China; submitted to Nucl. Phys. A (Proceedings of NN2009