979 resultados para Plants - Analysis
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The medium term hydropower scheduling (MTHS) problem involves an attempt to determine, for each time stage of the planning period, the amount of generation at each hydro plant which will maximize the expected future benefits throughout the planning period, while respecting plant operational constraints. Besides, it is important to emphasize that this decision-making has been done based mainly on inflow earliness knowledge. To perform the forecast of a determinate basin, it is possible to use some intelligent computational approaches. In this paper one considers the Dynamic Programming (DP) with the inflows given by their average values, thus turning the problem into a deterministic one which the solution can be obtained by deterministic DP (DDP). The performance of the DDP technique in the MTHS problem was assessed by simulation using the ensemble prediction models. Features and sensitivities of these models are discussed. © 2012 IEEE.
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The limited availability of foods that are free of pesticides has led Brazil to search for alternative production methods to meet the desires of consumers. Currently, organic cultivation represents a production system that complies with general expectations of producers and consumers. Organic cultivation is particularly interesting mainly because of its effect on plant secondary metabolite content, which may help plants to naturally combat pests; in humans, these substances can also contribute to the prevention of chronic diseases. We report on the extraction of glucosinolates (both as total glucosinolates and as benzylglucosinolate) with trifluoroacetic acid addition in a 70:30 MeOH:water (v/v). Total glucosinolates, determined by a thioglucosidase coupled assay, were measured in different Brassicaceae species and were similar to values reported in the literature. For broccoli, analyses were carried out separately on inflorescences, leaves and stalks; analyses were also conducted on thermally processed samples to simulate cooking. Furthermore, when the analysis was conducted on conventional and organic products, the highest concentrations of these substances were most often found in organically cultivated Brassicaceae. The benzylglucosinolate concentrations were evaluated on the same samples using HPLC. The concentration of benzylglucosinolate was significantly higher in organically cultivated vegetables, as well. © 2012 Elsevier Ltd.
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The Brazilian Savanna (locally called Cerrado) is an important biome presenting several plants that are used in popular medicine. However, the risks associated with the consumption of derivatives from these plants are generally unknown. Studies with compounds obtained from different species have shown the risks of DNA damage. The present work assessed the in vivo mutagenicity of three plant species used in popular medicine to treat human gastrointestinal disorders (Mouriri pusa, Qualea grandiflora and Qualea multiflora). The micronucleus assay was performed in peripheral blood of mice submitted to acute treatments. Results showed that no assessed extracts were mutagenic in vivo. In fact, the absence of mutagenicity in the present study indicates that the extracts do not contain compounds capable of inducing DNA breaks or chromosomal loss. However, further analysis should be performed in others systems to guarantee their safety, mainly to human chronic use.
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In this paper is reported the use of the chromatographic profiles of volatiles to determine disease markers in plants - in this case, leaves of Eucalyptus globulus contaminated by the necrotroph fungus Teratosphaeria nubilosa. The volatile fraction was isolated by headspace solid phase microextraction (HS-SPME) and analyzed by comprehensive two-dimensional gas chromatography-fast quadrupole mass spectrometry (GC. ×. GC-qMS). For the correlation between the metabolic profile described by the chromatograms and the presence of the infection, unfolded-partial least squares discriminant analysis (U-PLS-DA) with orthogonal signal correction (OSC) were employed. The proposed method was checked to be independent of factors such as the age of the harvested plants. The manipulation of the mathematical model obtained also resulted in graphic representations similar to real chromatograms, which allowed the tentative identification of more than 40 compounds potentially useful as disease biomarkers for this plant/pathogen pair. The proposed methodology can be considered as highly reliable, since the diagnosis is based on the whole chromatographic profile rather than in the detection of a single analyte. © 2013 Elsevier B.V..
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The isotopic technique was employed to study boron (B) mobility in tomato and beetroot plants under protected cultivation conditions. An experiment was conducted in which both species grew in 10-dm3 vases filled with coconut fiber, under hydroponic conditions. The plants were subjected to four different treatments: (1) no B in the substratum and no foliar fertilization; (2) no B in the substratum, with foliar 10B fertilization; (3) B in the substratum, with foliar 10B fertilization; and (4) 10B in the substratum and no foliar fertilization. The biological growth variables and total B and 10B contents in the plant parts grown after the application of the nutrient were evaluated. For increasing B content in young tissues, the foliar application of this element was not as efficient as application via root system, indicating low mobility of B in the tissues of both beetroot and tomato plants. © 2013 Copyright Taylor & Francis Group, LLC.
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In this work, experimental results are reported for a small scale cogeneration plant for power and refrigeration purposes. The plant includes a natural gas microturbine and an ammonia/water absorption chiller fired by steam. The system was tested under different turbine loads, steam pressures and chiller outlet temperatures. An evaluation based on the 1st and 2nd Laws of Thermodynamics was also performed. For the ambient temperature around 24°C and microturbine at full load, the plant is able to provide 19 kW of saturated steam at 5.3 bar (161 °C), corresponding to 9.2 kW of refrigeration at -5 °C (COP = 0.44). From a 2nd law point-of-view, it was found that there is an optimal chiller outlet temperature that maximizes the chiller exergetic efficiency. As expected, the microturbine presented the highest irreversibilities, followed by the absorption chiller and the HRSG. In order to reduce the plant exergy destruction, it is recommended a new design for the HRSG and a new insulation for the exhaust pipe. © 2013 Elsevier Ltd. All rights reserved.
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Urban centers have a huge demand for electricity and the growing problem of the solid waste management generated by their population, a relevant social and administrative problem. The correct disposal of the municipal solid waste (MSW) generated in cities is one of the most complex engineering problems that involves logistics, safety, environmental and energetic aspects for its adequate management. Due to a national policy of solid wastes recently promulgated, Brazilian cities are evaluating the technical and economic feasibility of incinerating the non-recyclable waste. São José dos Campos, a São Paulo State industrialized city, is considering the composting of organic waste for biogas production and mass incineration of non-recyclable waste. This paper presents a waste-to-energy system based on the integration of gas turbines to a MSW incinerator for producing thermal and electric energy as an alternative solution for the solid waste disposal in São José dos Campos, SP. A technical and economic feasibility study for the hybrid combined cycle plant is presented and revealed to be attractive when carbon credit and waste tax are included in the project income. © 2013 Elsevier Ltd.
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The wavelength-integrated absorbance (WIA) and summation of absorbance (∑ lines) of different lines were evaluated to enhance sensitivity and determine B, P and S in medicinal plants by HR-CS FAAS. The lowest LOD for B (0.5mgL-1) and P (13.7mgL-1) was obtained by integration of lines 249.773nm (3pixels) and 247.620nm (5pixels), respectively. The ∑ lines for CS at 257.595nm and 257.958nm furnished LOD=30.5mgL-1, ca. 10% lower than the LOD obtained for the WIA using 257.595nm and 5pixels. Data showed the advantage of WIA over ∑ lines to improve sensitivity for all analytes. Under optimized conditions, calibration curves in the 1.0-100mgL-1 B and 50.0-2000mgL-1 P, S ranges were consistently obtained. Results obtained with the HR-CS FAAS method were in agreement at 98% and 95% confidence level with certified values for B and P, respectively. And results for S were in accordance to non-certified values. Concentrations of B, P, and S in 12 medicinal plants analyzed by the proposed method varied within the 19.4-34.5mgkg-1 B, 719-3910mgkg-1 P and 1469-7653mgkg-1 S ranges. © 2012 Elsevier B.V.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Ten Brazilian medicinal plants used to treat gastritis and ulcers were carefully selected on the basis of ethnopharmacological importance and antiulcerogenic activity previously described. The antioxidant activity of the methanolic extracts was determined in analysis conditions that simulate a real biological activity on inhibition of the oxidative burst induced in neutrophils using Helicobacter pylori as activator, by a luminol-amplified chemiluminescence assay. The extracts, at low concentration (5 g/mL), exhibited a large variation in inhibitory effects of H. pylori-induced oxidative burst ranging from 48% inhibition to inactive, but all extracts, excluding Byrsonima intermedia, had inhibitory activity over 80% at the concentration of 100 g/mL. The total suppressive antioxidant capacity measured as the effective concentration, which represents the extract concentration producing 50% inhibition of the chemiluminescence induced by H. pylori, varies from 27.2 to 56.8 g/mL and was in the following order: Qualea parviflora > Qualea multiflora > Alchornea triplinervia > Qualea grandiflora > Anacardium humile > Davilla elliptica > Mouriri pusa > Byrsonima basiloba > Alchornea glandulosa > Byrsonima intermedia. The main groups of compounds in tested extracts are presented. Differences in the phytochemical profile, quantitatively and qualitatively, of these plants can explain and justify their protective effect on the gastric mucosa caused by the neutrophil-generated ROS that occurs when H. pylori displays its evasion mechanisms. © 2013 Cibele Bonacorsi et al.
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Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES)
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Background: Centromeres are essential for chromosome segregation, yet their DNA sequences evolve rapidly. In most animals and plants that have been studied, centromeres contain megabase-scale arrays of tandem repeats. Despite their importance, very little is known about the degree to which centromere tandem repeats share common properties between different species across different phyla. We used bioinformatic methods to identify high-copy tandem repeats from 282 species using publicly available genomic sequence and our own data.Results: Our methods are compatible with all current sequencing technologies. Long Pacific Biosciences sequence reads allowed us to find tandem repeat monomers up to 1,419 bp. We assumed that the most abundant tandem repeat is the centromere DNA, which was true for most species whose centromeres have been previously characterized, suggesting this is a general property of genomes. High-copy centromere tandem repeats were found in almost all animal and plant genomes, but repeat monomers were highly variable in sequence composition and length. Furthermore, phylogenetic analysis of sequence homology showed little evidence of sequence conservation beyond approximately 50 million years of divergence. We find that despite an overall lack of sequence conservation, centromere tandem repeats from diverse species showed similar modes of evolution.Conclusions: While centromere position in most eukaryotes is epigenetically determined, our results indicate that tandem repeats are highly prevalent at centromeres of both animal and plant genomes. This suggests a functional role for such repeats, perhaps in promoting concerted evolution of centromere DNA across chromosomes.
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)
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Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP)