[Show abstract][Hide abstract] ABSTRACT: Edge effects and linear canopy openings may change ecological patterns and processes on forests.
Here we investigate if these openings in a lowland Brazilian Atlantic forest cause edge effects on
seedlings. We sampled seedling communities at forest edges near to two linear canopy openings
(gas pipeline and power line) and in interiors far from edges. Comparisons between the seedling
communities were performed to access edge effects. Density and basal area patterns were compared using, hierarchical two-way ANOVAs and the number of newly germinated seedlings, mortality and resprouts were compared by one-way ANOVAs. The results showed that edge effects of
linear canopy openings affect seedling communities leading to low densities on edges that showed
less favorable conditions for arrival, establishment and initial survival. The basal area patterns
were not affected by edge effects apparently by the resistance of the seedlings that have more than
4 mm diameter. Therefore, linear canopy openings caused edge effects, which determine low
seedling densities on edges. However this pattern is not due to increase mortality on these edges,
but probably caused by the reduction on germination and establishment.
[Show abstract][Hide abstract] ABSTRACT: Ethyl acetate extracts of cultures grown in liquid Czapek and on solid rice media of the fungal endophyte Fusarium oxysporum SS46 isolated from the medicinal plant Smallanthus sonchifolius (Poepp.) H. Rob., Asteraceae, exhibited considerable cytotoxic activity when tested in vitro against human cancer cells. Chromatographic separation yielded anhydrofusarubin (1) and beauvericin (2) that were identified based on their 1H and 13C NMR data. Compounds 1 and 2 showed the strongest cytotoxic activity against different cancer cell lines. Compound 2 also showed promising activity against Leishmania braziliensis. Hexanic extract of F. oxysporum SS50 grown on solid rice media also afforded a mixture of compounds that displayed cytotoxic activity against different cancer cell lines. Chemical analysis of the mixture of compounds, investigated by gas chromatography-mass spectrometry (GC-MS), showed that there was a predominance of methyl esters of fatty acids and alkanes.
Full-text · Article · Nov 2012 · Revista Brasileira de Farmacognosia
[Show abstract][Hide abstract] ABSTRACT: In this paper, the diffusion of solutes in natural clay from a concentrated solution consisting primarily of
ammonium, sodium and chloride ions at a pH level of 8 was studied and was based on an existing 20-
year-old landfill. Contaminant transport through clay liners was predicted using transport and reaction
geochemical codes to help explain the experimental data. The model predicted the chloride anion
diffusion and cation exchange processes for three different experiments: (1) small-scale interactions in
compacted clay, (2) 1:1 European Union (EU) Directive demonstration experiments (0.5-m-thick clay
barrier), and (3) analysis of a bore hole with core recovery drilled in an old landfill located above a similar
type of clay as that studied in (1) and (2). Orders of magnitude between 10�10 and 10�9 m2 s�1 were used
for the apparent diffusion coefficient to fit the chloride profiles at the different scales; however, at larger
space and time scales, diffusion was retarded due to the presence of more consolidated, non mechanically disturbed clay materials at large depths in a natural clay-rock emplacement.
No preview · Article · Jan 2012 · Journal of Environmental Management
[Show abstract][Hide abstract] ABSTRACT: The present work reports on the cooperation between three Higher Education establishments from Hungary and Portugal. Students from one country are remotely accessing experimental facilities, which are physically in one of the other countries. The cooperation among these Higher Education establishments allowed the
development, testing and improvement of remotely accessed experiments. This work reports on the characteristics and testing of two distinct experiments: theThermocouples Time Delay Measurement System and the Temperature Calibration System. Detailed information is provided on the theoretical background, development, students’ feedback and future use and cooperation.
[Show abstract][Hide abstract] ABSTRACT: This work presents a system for on-line study purposes and for demonstrative operation of water quality monitoring based on previous full-scale trials in a commercial aquaculture facility under the scope of a R&D project. This system is still under development, and was designed for sharing resources in R&D activities and later in distance learning blended courses. An application developed in LabVIEW is responsible for receiving information from physical and chemical data (water level, flow, oxygen, temperature, pH, ORP and CO2) through a hardware interface. The acquired data are recorded in a Microsoft Access database that can be locally queried as desired. An IP camera allows students to observe the system in real-time. Students can log into the system and follow the real-time variations of a specific water quality parameter and the synergetic effects of these changes on the levels of other constituents. The water tanks contain no living beings in order to allow free adjustments of the parameters under study. The system description, data and remote access link is integrated in a basic course available in a Moodle® server. The goal of this course is to provide a stimulating interdisciplinary environment to a diverse group of undergraduate students, where critical research questions related to water are addressed. This system, unique in the area concerning with our knowledge, intends to contribute also to students’ training on data monitoring and analysis; and to nourish analytical skills and creativity of future scientists by encouraging potential graduate students to go further. Finally, this system allows the students to be familiar with the use of some new information technologies.
No preview · Article · Jan 2011 · International Journal of Emerging Technologies in Learning (iJET)
[Show abstract][Hide abstract] ABSTRACT: Resumo Estudos fenológicos auxiliam na compreensão do comportamento das espécies em resposta a alterações no ambiente e são também importantes para a conservação e manejo das mesmas. A fenologia de Paratecoma peroba (Record & Mell) Kuhlm. foi estudada no período de outubro/2005 a dezembro/2007 na Mata do Carvão (Estação Ecológica Estadual de Guaxindiba), São Francisco do Itabapoana, RJ. As observações foram realizadas mensalmente, exceto durante a fase de floração que ocorreram em intervalos quinzenais. Acompanharam-se 42 indivíduos que apresentaram comportamento fenológico sazonal, com a senescência foliar ocorrendo no início da estação seca e a queda foliar entre meados e final desta mesma estação. O brotamento de novas folhas ocorreu no início da estação chuvosa. As percentagens de Fournier encontradas para as fenofases reprodutivas foram baixas e somente indivíduos com DAP > 16 cm apresentaram botões florais. No final da estação seca de 2005, os indivíduos apresentaram fenofases reprodutivas, com a floração ocorrendo na transição da estação seca para chuvosa e a frutificação foi longa (cerca de um ano) tendo início na estação chuvosa (novembro), com os frutos dispersando as sementes aladas no início da estação chuvosa seguinte. Nos anos seguintes, 2006 a 2008, não foi observado evento de floração. A espécie foi caracterizada como decídua, apresentando periodicidade de floração supra-anual. Palavras chave: brotamento, botões florais, fenologia, Mata atlântica, senescência. Abstract Phenological studies help the understanding of species behavior as a result to environmental changes and are also important for species conservation and management. The phenology of Paratecoma peroba (Record & Mell) Kuhlm. was studied from October/2005 to December/2007 in Mata do Carvão (Guaxindiba Ecological Station), São Francisco do Itabapoana, RJ. The observations were done in one-month intervals, except the flowering that was done at two week intervals. Forty two individuals were systematically observed. They showed phenological pattern characterized by the seasonal occurrence of the phenophases, with leaf senescence occurring at the beginning of the dry season and the leaf fall between the middle and the end of this season. New leaves were flushed at the beginning of the wet season. Fournier intensity values were low for reproductive phenophases and only trees with diameter at breast height (dbh) > 16 cm sprouted flowers. Reproductive phenophases started at the end of dry season of 2005, with flowering occurring in the transition of the dry to the wet season. Fruiting was long (one year), starting at the beginning of the wet season (November) with dispersion of the anemocoric seeds occurring at the beginning of the following wet season. However, in the following years (2006-2008), flowering did not occur. This species was classified as deciduous, with a supra-annual flowering period.
[Show abstract][Hide abstract] ABSTRACT: The objective of this work was to investigate possible modes of action of the yeast Cryptococcus magnus in controlling anthracnose (Colletotrichum gloeosporioides) on post harvested papaya fruits. Scanning electron microscopy was used to analyze the effect of the yeast on inoculations done after harvest. Results showed that C. magnus is able to colonize wound surfaces much faster than the pathogen, outcompeting the later for space and probably for nutrients. In addition, C. magnus produces a flocculent matrix, which affects hyphae integrity. The competition for space and the production of substances that affect hyphae integrity are among the most important modes of action of this yeast.
Preview · Article · Jan 2007 · Pesquisa Agropecuária Brasileira