Fungos associados a sementes de açaí: efeito da temperatura e do teor de água das sementes durante o armazenamento.

O trabalho teve como objetivo verificar os efeitos do teor de água e da temperatura do ambiente de armazenamento na incidência de fungos e na germinação de sementes de açaí (Euterpe oleracea Mart.). Foram utilizadas sementes da cultivar BRS Pará, com teores de água de 43%, 37%, 30%, 26%, 21% e 12%, que foram acondicionadas em sacos de polietileno, armazenadas sob temperaturas de 20 ºC, 15 ºC e 10 ºC, durante 360 dias e submetidas a avaliações bimensais do teor de água, da germinação e da incidência de Penicillium sp., Aspergillus sp., Fusarium solani e Fusarium verticillioides. Foi adotado o delineamento experimental inteiramente casualizado com quatro repetições para o teste de germinação e cinco repetições para os testes de sanidade. Foi observada maior ocorrência de Penicillium sp., e Aspergillus sp em sementes com teores de água abaixo de 30% e mantidas nas temperaturas de 15 ºC e 20 ºC. Enquanto, as maiores incidências de fungos do gênero Fusarium foram encontradas em sementes armazenadas com graus de umidade de 43% e 37% e mantidas em temperatura de 10 ºC

Electrostatic self-force in (2+1)-dimensional cosmological gravity

Point sources in (2+1)-dimensional gravity are conical singularities that modify the global curvature of the space giving rise to self-interaction effects on classical fields. In this work we study the electrostatic self-interaction of a point charge in the presence of point masses in (2+1)-dimensional gravity with a cosmological constant.Comment: 9 pages, Late

The self-energy of a charged particle in the presence of a topological defect distribution

In this work we study a charged particle in the presence of both a continuous distribution of disclinations and a continuous distribution of edge dislocations in the framework of the geometrical theory of defects. We obtain the self-energy for a single charge both in the internal and external regions of either distribution. For both distributions the result outside the defect distribution is the self-energy that a single charge experiments in the presence of a single defect.Comment: 12 pages, Revtex4, two figures,to appear in Int. Joun. Mod. Phys.

The pasta phase within density dependent hadronic models

In the present paper we investigate the onset of the pasta phase with different parametrisations of the density dependent hadronic model and compare the results with one of the usual parametrisation of the non-linear Walecka model. The influence of the scalar-isovector virtual delta meson is shown. At zero temperature two different methods are used, one based on coexistent phases and the other on the Thomas-Fermi approximation. At finite temperature only the coexistence phases method is used. npe matter with fixed proton fractions and in beta-equilibrium are studied. We compare our results with restrictions imposed on the the values of the density and pressure at the inner edge of the crust, obtained from observations of the Vela pulsar and recent isospin diffusion data from heavy-ion reactions, and with predictions from spinodal calculations.Comment: 15 pages, 11 figures and 7 table

Response or the aphid parasitoid Aphidius funebris to volatiles from undamaged and aphid-infested Centaurea nigra.

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The effect of medium composition on interleukin-2 production by murine EL-4 thymoma cells

Due to the role of interleukin-2 (IL-2) in the mediation of immune response, this cytokine has been used in the treatment of some types of cancer and infectious diseases. However, relatively high levels of this cytokine are required to achieve significant activity. The aim of this work was to study a culture medium composition designed to increase the production of IL-2 by suspended murine EL-4 cells. The cultivations were carried out aiming at producing IL-2 in stirred bioreactors. The effects of concentration of glutamine, phorbol-12-myristate-13-acetate (PMA), concanavalin A (Con A), Pluronic F68, and fetal calf serum (FCS) on cell viability and IL-2 production were evaluated. PMA alone was more efficient in IL-2 production than it was in association with Con A. The maximum IL-2 production was around 162 ng/mL with 856 ng/mL PMA and 1.45% (v/v) FCS.16517

Aharonov-Bohm-like effect for light propagating in nematics with disclinations

Using a geometric approach for the propagation of light in anisotropic media, we investigate what effect the director field of disclinations may have on the polarization state of light. Parallel transport around the defect, of the spinor describing the polarization, indicates the acquisition of a topological phase, in analogy with the Aharonov-Bohm effect.Comment: 6 pages, to appear in Europhysics Letter

Convergence in myoelectric control:Between individual patterns of myoelectric learning

Objective: To support the design of assistive devices and prostheses, we investigated the changes in upper-limb muscle synergies during the practice of a myoelectric controlled game using proportional-sequential control. Methods: We evaluated 1) whether individual muscle synergies change in their structure; 2) variability; 3) distinctiveness; and 4) whether individuals become more similar with practice. Ten individuals practiced a myoelectric-controlled serious game for ten consecutive days (25 min/day) and one day after one week without training (retention). Results: The results showed that individuals decreased the number of synergies employed and modified their flexor synergies structure, becoming more similar as a group with practice. Nevertheless, within-individual synergies' variability and distinctiveness did not change. Conclusion: These results point out that individuals do not demonstrate muscle patterns less variable or differentiable after practice. However, participants increased performance and became more attuned to the task dynamics. Significance: The present findings indicate that, depending on the task requirements, individuals converge to more similar muscle activation patterns - a feature that should be further explored in prosthetic design