Time filter

Source Type

Mielke M.S.,University Estadual Of Santa Cruz | Schaffer B.,University of Florida
Environmental and Experimental Botany | Year: 2010

Eugenia uniflora L. (Myrtaceae) is a small tropical or subtropical shrub or tree native to South America and cultivated for different purposes in several areas of the world. It grows well in sun or partially shaded environments and is native to habitats that experience periodic soil waterlogging. The interactive effects of light intensity and soil flooding on the photosynthetic performance and growth of E. uniflora in containers were examined. Taking into account the ecological characteristics of the species, two hypotheses were tested: (a) E. uniflora seedlings subjected to soil flooding are able to maintain photosynthetic and growth rates similar to those of non-flooded seedlings and (b) photosynthetic and growth responses to soil flooding are influenced by the light environment. Seedlings pre-acclimated to full (≈44 mol m-2 day-1) and partial (≈12 mol m-2 day-1) sunlight for 55 days were subjected to soil flooding for 36 days. Photosynthetic light-response curves were analyzed for flooded and non-flooded plants two weeks after flooding and four weeks after soil drainage (unflooding plants). Plant dry weight was analyzed at the end of soil flooding period and 35 days after soil drainage. Soil flooding negatively affected the gross light-saturated photosynthetic rate expressed on an area and dry weight basis (Amax-area and Amax-weight, respectively), stomatal conductance of water vapor (gssat), and plant growth and survival. Four weeks after soil drainage, flooding also significantly reduced the apparent quantum yield (α). There were no significant interactions between flooding and light intensity on plant survival and leaf gas exchange variables, with the exception of the intrinsic water use efficiency (A/gs) four weeks after soil drainage. The effects of flooding on plant dry weight and A/gs were more pronounced in full sun than in partial sunlight and the harmful effects of soil flooding on leaf gas exchange and growth persisted after soil drainage. Changes in A/gs and α four weeks after soil drainage were interpreted as evidence of non-stomatal limitation to photosynthesis. E. uniflora is moderately sensitive to soil flooding and the effects of flooding on changes in photosynthetic performance and growth of plants are partially influenced by the light environment. © 2009 Elsevier B.V. Source

Souza M.M.,University Estadual Of Santa Cruz
Genetics and molecular research : GMR | Year: 2010

Cytological preparations for the fluorescent in situ hybridization (FISH) technique require cytoplasm-free metaphases, with well-spread chromosomes, for the localization of DNA sequences and chromosome mapping. We tested various procedures for FISH analysis of Passiflora cacaoensis, P. gardneri and hybrid F progeny of P. gardneri x P. gibertii. Two treatments with four enzymes and three incubation times were compared. The material was treated with 1.0 M HCl before enzymatic digestion. The following criteria were used to determine the quality of the metaphases: a) lack or presence of cytoplasm; b) well-spread chromosomes or with overlap; c) complete or incomplete chromosome number (2n). The enzyme Pectinex(®) SP ULTRA gave the best performance, with the shortest incubation time. The best results were observed after 30 min of incubation; more than 70% of the metaphases did not have large amounts of cytoplasm or overlapping chromosomes, and about 75% maintained the chromosome number. FISH was carried out using a 45S rDNA probe (pTa71) labeled with biotin and detected with fluorescein isothiocyanate. Sites with strong staining and without nonspecific signals were observed. Our methodological adaptations allowed the preparation of metaphase slides of high quality for the FISH technique, with less time required for the preparation of samples. Source

Alves E.O.,University Estadual Of Santa Cruz
Genetics and molecular research : GMR | Year: 2012

We investigated seven distance measures in a set of observations of physicochemical variables of mango (Mangifera indica) submitted to multivariate analyses (distance, projection and grouping). To estimate the distance measurements, five mango progeny (total of 25 genotypes) were analyzed, using six fruit physicochemical descriptors (fruit weight, equatorial diameter, longitudinal diameter, total soluble solids in °Brix, total titratable acidity, and pH). The distance measurements were compared by the Spearman correlation test, projection in two-dimensional space and grouping efficiency. The Spearman correlation coefficients between the seven distance measurements were, except for the Mahalanobis' generalized distance (0.41 ≤ rs ≤ 0.63), high and significant (rs ≥ 0.91; P < 0.001). Regardless of the origin of the distance matrix, the unweighted pair group method with arithmetic mean grouping method proved to be the most adequate. The various distance measurements and grouping methods gave different values for distortion (-116.5 ≤ D ≤ 74.5), cophenetic correlation (0.26 ≤ rc ≤ 0.76) and stress (-1.9 ≤ S ≤ 58.9). Choice of distance measurement and analysis methods influence the. Source

Barbosa P.C.,University Estadual Of Santa Cruz
Drug testing and analysis | Year: 2012

Ayahuasca is a psychedelic brew originally used for magico-religious purposes by Amerindian populations of the western Amazon Basin. Throughout the last four decades, the use of ayahuasca spread towards major cities in all regions of Brazil and abroad. This trend has raised concerns that regular use of this N,N-dimethyltryptamine- and harmala-alkaloid-containing tea may lead to mental and physical health problems associated typically with drug abuse. To further elucidate the mental and physical health of ayahuasca users, we conducted a literature search in the international medical PubMed database. Inclusion criteria were evaluation of any related effect of ayahuasca use that occurred after the resolution of acute effects of the brew. Fifteen publications were related to emotional, cognitive, and physical health of ayahuasca users. The accumulated data suggest that ayahuasca use is safe and may even be, under certain conditions, beneficial. However, methodological bias of the reviewed studies might have contributed to the preponderance of beneficial effects and to the few adverse effects reported. The data up to now do not appear to allow for definitive conclusions to be drawn on the effects of ayahuasca use on mental and physical health, but some studies point in the direction of beneficial effects. Additional studies are suggested to provide further clarification. Copyright © 2012 John Wiley & Sons, Ltd. Source

Carvalho F.S.,University Estadual Of Santa Cruz
Genetics and molecular research : GMR | Year: 2011

We used PCR to test various protocols and define a technique for DNA extraction directly from chicken-shed stool samples for the identification of Eimeria species that parasitize birds. It was possible to extract and amplify DNA of seven Eimeria species from field stool samples, using both protocols tested; extractions made with phenol/chloroform protocols gave the best results. The primers were specific and sensitive, allowing amplification of samples containing as few as 20 oocysts, both in individual and in a multiplex PCR. Individualized PCR with the phenol/chloroform DNA extraction protocol detected a larger number of Eimeria species. Molecular diagnosis was found to be practical and precise, and can be used for monitoring and epidemiological studies of Eimeria. Source

Discover hidden collaborations