Allelopathic Influence of \u3ci\u3eEragrostis curvula\u3c/i\u3e Water Extract on Seed Germination and Seedling Growth of Two Other Species

Weeping lovegrass (Eragrostis curvula Schrad. Nees) is a very agressive tropical species and does not grow well with other species. This study was set up to investigate the allelopathic effect of various extract concentrations of weeping lovegrass on seed germination of white clover (Trifolium repens L.) and bentgrass (Agrostis stolonifera L.) and the seedling development of white clover. Labotatory and growth chamber studies were conducted. Extract concentrations of 13.6, 27.2, 40.8, 54.4, and 62.0 g/100mL of water were studied. Treatments were arranged in a completely ramdomized design with three replications. The allelopathic effect of weeping lovegrass was significant (P \u3c 0.01) on white clover andbentgrass. White clover was affected by lower extract concentration than bentgrass. The seedling growth of white clover was reduced when compared with the control (P \u3c 0.01) for root growth and (P \u3c 0.04) for whole plant. The osmotic potential also affected (P \u3c 0.01) seed germination of white clover. For the highest concentrated solution there was a decrease of 20% on the seed germination of white clover due to the water potential

Barn owl feathers as biomonitors of mercury: sources of variation in sampling procedures.

Given their central role in mercury (Hg) excretion and suitability as reservoirs, bird feathers are useful Hg biomonitors. Nevertheless, the interpretation of Hg concentrations is still questioned as a result of a poor knowledge of feather physiology and mechanisms affecting Hg deposition. Given the constraints of feather availability to ecotoxicological studies, we tested the effect of intra-individual differences in Hg concentrations according to feather type (body vs. flight feathers), position in the wing and size (mass and length) in order to understand how these factors could affect Hg estimates. We measured Hg concentration of 154 feathers from 28 un-moulted barn owls (Tyto alba), collected dead on roadsides. Median Hg concentration was 0.45 (0.076-4.5) mg kg(-1) in body feathers, 0.44 (0.040-4.9) mg kg(-1) in primary and 0.60 (0.042-4.7) mg kg(-1) in secondary feathers, and we found a poor effect of feather type on intra-individual Hg levels. We also found a negative effect of wing feather mass on Hg concentration but not of feather length and of its position in the wing. We hypothesize that differences in feather growth rate may be the main driver of between-feather differences in Hg concentrations, which can have implications in the interpretation of Hg concentrations in feathers. Finally, we recommend that, whenever possible, several feathers from the same individual should be analysed. The five innermost primaries have lowest mean deviations to both between-feather and intra-individual mean Hg concentration and thus should be selected under restrictive sampling scenarios

Produtividade de frutos de mangueira sob irrigação com uso da técnica PRD.

A mangueira Mangifera indica L. pertence à família Anacardiaceae. É originada do sul da Ásia, mais precisamente da Índia, onde há mais de 4000 anos é cultivada, e do arquipélago Malaio, de onde se disseminou por outras partes do mundo, inclusive as Américas. Com uma área cultivada superior a 31,2 mil hectares, dos quais 26,2 mil irrigados, a Bahia é o principal estado produtor e exportador de manga do país, tendo produzido em 2008, mais de 1,11 milhão de toneladas dessa fruta, o que corresponde a mais de 51 % da safra nacional. A PRD ou irrigação parcial do sistema radicular é uma técnica que tem o objetivo aplicar água de forma alternada entre os dois lados da planta para manter parte do sistema de raiz em contato com solo seco, enquanto o resto do sistema radicular está em uma condição molhada. Os mecanismos fisiológicos da prática de PRD estão baseados em estudos com plantas cultivadas em vaso onde freqüentemente raízes estavam artificialmente separadas em dois recipientes. Este trabalho teve como objetivo estudar a produtividade de frutos de mangueira sob manejo de irrigação utilizando a técnica de PRD em diferentes fases fenológicas.PDF. 050

Diagnóstico Rápido Participativo no Projeto de Assentamento Angico, Barra, BA.

O Projeto de Assentamento (PA) Angico está localizado a 60 Km do Município de Barra, numa área de 1.560 metros de largura com acesso ao rio Grande, totalizando aproximadamente 2.600 hectares. A área comum está dividida em lotes de 22 por 200 metros, todos com acesso ao rio Grande

Nuclear magnetic resonance measurements reveal the origin of the Debye process in monohydroxy alcohols

Monohydroxy alcohols show a structural relaxation and at longer time scales a Debye-type dielectric peak. From spin-lattice relaxation experiments using different nuclear probes an intermediate, slower-than-structural dynamics is identified for n-butanol. Based on these findings and on diffusion measurements, a model of self-restructuring, transient chains is proposed. The model is demonstrated to explain consistently the so far puzzling observations made for this class of hydrogen-bonded glass forming liquids.Comment: 4 pages, 4 figure

An intact signal peptide on dengue virus E protein enhances immunogenicity for CD8+ T cells and antibody when expressed from modified vaccinia Ankara

Dengue is a global public health concern and this is aggravated by a lack of vaccines or antiviral therapies. Despite the well-known role of CD8(+) T cells in the immunopathogenesis of Dengue virus (DENV), only recent studies have highlighted the importance of this arm of the immune response in protection against the disease. Thus, the majority of DENV vaccine candidates are designed to achieve protective titers of neutralizing antibodies, with less regard for cellular responses. Here, we used a mouse model to investigate CD8(+) T cell and humoral responses to a set of potential DENV vaccines based on recombinant modified vaccinia virus Ankara (rMVA). To enable this study, we identified two CD8(+) T cell epitopes in the DENV-3 E protein in C57BL/6 mice. Using these we found that all the rMVA vaccines elicited DENV-specific CD8(+) T cells that were cytotoxic in vivo and polyfunctional in vitro. Moreover, vaccines expressing the E protein with an intact signal peptide sequence elicited more DENV-specific CD8(+) T cells than those expressing E proteins in the cytoplasm. Significantly, it was these same ER-targeted E protein vaccines that elicited antibody responses. Our results support the further development of rMVA vaccines expressing DENV E proteins and add to the tools available for dengue vaccine development.Parts of this work were supported by the InstitutoNacional de Ciência e Tecnologia de Vacinas–INCTV (National Insti-tute of Science and Technology of Vaccines) and by a FAPEMIGPPM grant (CBB, PPM-00461-11). BRQ was a CAPES/PDSE fellow-ship recipient (8815-11-9). FGF is a CNPq fellowship recipient. DCTis an ARC Future Fellow (FT110100310)

Doses crescentes de nitrogênio e a qualidade da forragem do Capim-Elefante Anão (Pennisetum purpureum Schum.) Cv. Mott.

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