88 resultados para Alga vermelha - Classificação
Resumo:
In the present study, six families of sulfated polysaccharides were obtained from seaweed Dictyopteris delicatula (Lamouroux, 1809) and their anticoagulant, antioxidant and antitumor activities were evaluated. All fractions showed anticoagulant activity on aPTT assay, but not on PT assay. Fractions also exhibited total antioxidant activity, superoxide radical scavenging capacity and ferric chelating property. Thus, six fractions (F0.5v, F0.7v, F1.0v, F1.3v, F1.5v e F2.0v) we obtained by proteolytic digestion, followed by acetone fractionation and molecular sieving on Sephadex G-100. Chemical analyses demonstrated that all polysaccharides contain heterofucans composed mainly of fucose, xylose, glucose, galactose, uronic acid, and sulfate. Any fractions changed the PT. However, all fractions were able on double the aPPT on a dose-dependent manner. The heterofucans F0.7v and F1.0v showed low anticoagulant activity while F1.5v presented the most prominent anticoagulant activity .When compared to Clexane®, a low molecular weight heparin, at same concentration F1.5v presented similar anticoagulant activity. The fucans F0.5v and F0.7v at 1.0 mg/mL showed high ferric chelating activity (~45%), whereas fucans F1.3v (0.5 mg/mL) showed considerable reducing power, about 53.2% of the activity of vitamin C. The fucan F1.5v presented the most prominent anticoagulant activity. The best antiproliferative activity was found with fucans F1.3v and F0.7v. However, F1.3v activity was much higher than F0.7v inhibiting almost 100% of HeLa cell proliferation. These fucans have been selected for further studies on structural characterization as well as in vivo experiments, which are already in progress
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The regulation of the inflammatory response is essential to maintain homeostasis. Several studies have been performed to search new drugs that can contribute to avoiding or minimizing an excessive inflammatory process. The aim of this study was to evaluate the effect of extracts of green algae Caulerpa mexican in models of inflammation. In mice, the model of peritonitis induced inflammatory zymosan pretreatment of mice with aqueous and methanol extracts of C. mexican was able to reduce cell migration to the peritoneal cavity. Treatment of mice with extracts of C. mexican also reduced the ear edema induced by xylene and exerted inhibitory action on the migration of leukocytes in inflammation-induced zymosan the air pouch, and timedependent for the extracts tested in the model of ulcerative colitis induced by DSS 3%, the extract methanol, but not the aqueous C. mexican, significantly reduced the clinical symptoms of colitis, as well as the production of proinflammatory cytokines in the culture of mouse colon, in the histological analysis there was a slight reduction of inflammation in the intestinal mucosa. We concluded that the administration of the extracts resulted in the reduction of cell migration to different sites as well as reducing the edema formation induced by chemical irritant. This study demonstrates for the first time the antiinflammatory effect of aqueous and methanolic extracts from green marine algae Caulerpa mexican
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The main aim of this study was to compare the procedure for dehydration of Gracilaria birdiae prepared handmade and laboratory, collected in the northern coast of Rio Grande do Norte. The sample was collected in the Rio do Fogo beach in march 2009. The sample collected followed by two processing, the first the material prepared in laboratory was air-dried at 50°C for 24 hours in air-flow oven. The second the handmade sample was air-dried on the sun during three days. The extract was prepared in three different solvents: ethanol, hydroethanol and water, resulting in ethanol, hidroethanol and aqueous extracts from handmade and laboratory sample. In according with results only the ethanol extract was fractionated yielding the fractions hexane, dichloromethane and ethyl acetate fractions. The different process to obtain Gracilaria birdiae resulted in the samples with different shades. The soluble solids content was higher in the laboratory sample. The chemical composition the both samples were characterized by presenting a considerable amounts of carbohydrates, with amior percentage protein and ash, respectively, in the handmade and laboratory sample. In two samples showed a low content of lipids and the lipid profile showed a higher proportion of monounsaturated fatty acids, with the absence polyunsaturated handmade sample. The phytochemical screening by chemical reactions showed the presence of flavonoids, tannins, alkaloids and saponins the laboratory sample, presenting a greater diversity of bioactive compounds. Through of the analysis by thin layer chromatography was possible to identify the phytosterols β-sitosterol and stigmasterol the both samples, also suggest the presence of β-carotene and chlorophyll α the laboratory sample. The levels of total phenolics and flavonoids were more significant in the ethanol extract of the laboratory sample. The in vitro lethality showed that extracts of the laboratory sample and handmade from 125 to 500 μg/ mL, respectively, were highly lethal. In the evaluation of antioxidant capacity by the system β-carotene/ácido linoleic method and by DPPH radical scavernging assay, the ethanol extract from the laboratory process showed significantly greater activity than the other extracts, being and the first and second methods, respectively, lower and equivalent to the synthetic antioxidant BHT. The handmade ethanol extract has not demonstrated skill in deactivating free radicals, but showed activity in inhibiting lipid peroxidation, although the values were significantly lower than the laboratory sample. We conclude that the dehydration process in the laboratory is the most efficient technique to maintenance of the chemical composition present in the seaweed, providing beneficial properties such as antioxidant capacity. We emphasize that this property can be explored with the objective of adding commercial value to the final product, which will promote the expansion of production of this seaweed in the community of Rio do Fogo
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The present study aimed to characterize the thermal profile of wood fired oven used by the red ceramic industry in Parelhas, in the Seridó region/RN, aiming to propose structural interventions that can contribute to increasing productivity and product quality, optimize wood consumption and mitigate existing losses during the burning process. The study was conducted at Cerâmica Esperança in the city of Parelhas -RN, Brazil, during the period from August 2012 to September 2013. Four treatments were performed with three replicates, ie, with, a total of 12 experimental units (burnings). In the first stage 4 treatments were performed with three replicates, totaling 12 experimental units (firings). In the second stage 2 treatments were performed with three replications, totaling 6 experimental units (firings). The physical characteristics of the wood were analyzed using standard NBR 11941 and NBR 7190 for basic density and moisture, respectively. The clay was used as a reference parameter for distinguishing treatments. For both the analysis and characterization was carried out using techniques of fluorescence X (XRF) rays, X-ray diffraction (XRD) analysis, particle size analysis (FA). In the first and second stages were monitored: the time during the firing process, the amount of wood used at each firing, the number of parts enfornadas for subsequent determination of the percentages of losses, but also product quality. To characterize the thermal profile of the oven, we measured the temperature at 15 points scored in the surface charge put into the oven. Measurements were taken every 30 minutes from preheat until the end of burning, using a pyrometer laser sight sighting from preheating until the end of burning. In the second step 12 metal cylinders distributed on the oven walls, and the cylinder end walls 8 of the furnace 2 and rollers on each side walls are installed equidistant to 17 cm from the soil and the surface 30 of the wall are installed. The cylinders distributed on the front were placed 50 cm above the furnace, and the base of the oven 20 cm distant from the ground. 10 also thermocouples were installed, and five thermocouples distributed 1.77 cm above the combustion chambers, and one thermocouple on each side, and three thermocouples in front of the oven. We carried out the measurements of the temperatures every 1 hour during the burning two hours in cooling the cylinders with a pyrometer and thermocouples for dattaloger. These were fixed with depth of 30 cm from the wall. After statistical analysis it was found that: the thermal profile of the furnace surface and at different heights was heterogeneous; and the ranges of density and moisture content of wood are within recommended for use as an energy source standards. We conclude that even at low temperatures reached during firing there was a significant production of good quality products, this is due to high concentrations of iron oxide and potassium oxide found in clay, which lowers the melting point of the piece. The average burn time for each step varied 650-2100 minutes wood consumption was on average 20 m3, product quality was on average 16% of first quality, 70% second, third and 5% to 10% loss . The distance between the wire and the surface of the oven was a significant parameter for all treatments, but with different variations, meaning that the wire should not be so generic and unique form, used as a criterion for completion of the burn process. The central part of the furnace was the area that reached higher temperature, and in a unified manner, with the highest concentration of top quality products. The ideal temperature curve, which provided the highest quality of ceramic products was achieved in the central part of the furnace
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The venous ulcer is an epidemiological problem of high prevalence, causing disability and dependence. Assess the tissue impairment level of patients with venous lesions, within a nursing referential, is relevant for the implementation of a directed assistance to specific clientele. Thus, this work aims to characterize the health status regarding the integrity the lower limbs skin of patients with venous ulcers, according to the of tissue integrity outcome indicators from the Nursing Outcomes Classification. A cross-sectional study conducted in a university hospital in Natal - Rio Grande do Norte. The sample consisted of 50 participants, selected through consecutive sampling. Data collection occurred through a interview and physical examination form and a operational definitions tool for indicators of the nursing Tissue Integrity outcome directed to patients with venous ulcer, applied from February to June 2012. Data analysis was done by descriptive statistics and nonparametric tests (Spearman, Kruskal-Wallis and Mann-Whitney tests). The project was approved by the Research Ethics Committee with protocol 608/11 and Presentation Certificate to Ethical Consideration No. 0038.0.294.000-11. The results were presented using three scientific articles derivatives of research. It was found that the indicators show moderate impairment, light and not impaired, as the median. The respondents had an average of 59.72 years, 66% female, 50% were retired, 60% with a partner, 44% had arterial hypertension, 26% allergies, 20% diabetes mellitus, 96% were sedentary, 14% drank alcohol and 6% were smokers. There was a statistically significant correlation of low intensity between age and hydration (p=0.032; rs=-0.304) and skin desquamation (p=0.026; rs=-0.316), family income and necrosis (p=0.012; rs=-0.353); Ankle Brachial Index and tissue perfusion (p=0,044; rs=-0,329); Diabetes Mellitus and texture (p=0.015) and tissue perfusion (p=0.026); allergy and texture (p=0.034), physical activity and hydration (p=0.034), smoking and thickness (p=0.018), and alcohol consumption and exudate (p=0.045). We conclude that the patients had light to moderate impairment, indicating a good state of health on the integrity of the skin of the lower limbs, according to the indicators of the outcome of tissue integrity Classification Nursing Outcomes valued in the present study. It is believed that the evaluation of impairment tissue using a self-nursing system and its relation with socioeconomic, clinical and risk factors are unique tools in the care planning and in the wound healing
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The objective of this work is to draw attention to the importance of use of techniques of loss prevention in small retail organization, analyzing and creating a classification model related to the use of these in companies. This work identifies the fragilities and virtues of companies and classifies them relating the use of techniques of loss prevention. The used methodology is based in a revision of the available literature on measurements and techniques of loss prevention, analyzing the processes that techniques needed to be adopted to reduce losses, approaching the "pillars" of loss prevention, the cycle life of products in retail and cycles of continues improvement in business. Based on the objectives of this work and on the light of researched techniques, was defined the case study, developed from a questionnaire application and the researcher's observation on a net of 16 small supermarkets. From those studies a model of classification of companies was created. The practical implications of this work are useful to point mistakes in retail administration that can become losses, reducing the profitability of companies or even making them impracticable. The academic contribution of this study is a proposal of an unpublished model of classification for small supermarkets based on the use of techniques of loss prevention. As a result of the research, 14 companies were classified as Companies with Minimum Use of Loss Prevention Techniques - CMULPT, and 02 companies were classified as Companies with Deficient Use of Loss Prevention Techniques - CDULPT. The result of the research concludes that on average the group was classified as being Companies with Minimum Use of Techniques of Prevention of Losses EUMTPP, and that the companies should adopt a program of loss prevention focusing in the identification and quantification of losses and in a implantation of a culture of loss prevention
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A presente dissertação representa uma contribuição na resolução dos problemas que se apresentam no setor das indústrias de cerâmica vermelha, apresentamos um modelo, baseado na estratégia do QFD (Desdobramento da Função Qualidade), na qual associa os requisitos dos consumidores na elaboração dos projetos do produto e dos processos de produção. A qualidade do produto é avaliada tanto no aspecto interno(especificações técnicas) quanto no aspecto externo (qualidades exigidas pelos clientes). A pesquisa mostra, além da realidade que vive o setor das indústrias de cerâmica, a importância e os atributos da qualidade definidos pelos consumidores relativo aos tijolos cerâmicos de vedação. O trabalho também mostra os resultados da aplicação do modelo numa das empresas do setor, através de desdobramentos da qualidade exigida, se estabelece a qualidade planejada, mostra ainda a posição da empresa em relação aos concorrentes em função do desempenho do produto. Procura-se ainda, através de sugestões de melhorias, atacar os problemas das falhas na qual geram o desperdício
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Este trabalho tem como objetivo estudar os sistemas de Classificações existentes para a garantia da gestão da qualidade no setor hoteleiro, tendo como foco principal a Matriz de Classificação para os Meios de Hospedagem da EMBRATUR e a ISO 9000, observando os benefícios que esses sistemas e/ou processos de gestão poderão vir a proporcionar para o setor hoteleiro no que se refere à qualidade de seus serviços. Para a obtenção dessas informações foi realizada uma análise comparativa dos sistemas de gestão da qualidade através de pesquisas bibliográficas e de questionários enviados para empreendimentos hoteleiros certificados e classificados, onde os principais resultados fornecidos pela pesquisa foram trabalhados de forma a apresentar, de maneira clara, a superioridade de um sistema em relação ao outro
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The use of the maps obtained from remote sensing orbital images submitted to digital processing became fundamental to optimize conservation and monitoring actions of the coral reefs. However, the accuracy reached in the mapping of submerged areas is limited by variation of the water column that degrades the signal received by the orbital sensor and introduces errors in the final result of the classification. The limited capacity of the traditional methods based on conventional statistical techniques to solve the problems related to the inter-classes took the search of alternative strategies in the area of the Computational Intelligence. In this work an ensemble classifiers was built based on the combination of Support Vector Machines and Minimum Distance Classifier with the objective of classifying remotely sensed images of coral reefs ecosystem. The system is composed by three stages, through which the progressive refinement of the classification process happens. The patterns that received an ambiguous classification in a certain stage of the process were revalued in the subsequent stage. The prediction non ambiguous for all the data happened through the reduction or elimination of the false positive. The images were classified into five bottom-types: deep water; under-water corals; inter-tidal corals; algal and sandy bottom. The highest overall accuracy (89%) was obtained from SVM with polynomial kernel. The accuracy of the classified image was compared through the use of error matrix to the results obtained by the application of other classification methods based on a single classifier (neural network and the k-means algorithm). In the final, the comparison of results achieved demonstrated the potential of the ensemble classifiers as a tool of classification of images from submerged areas subject to the noise caused by atmospheric effects and the water column
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The skin cancer is the most common of all cancers and the increase of its incidence must, in part, caused by the behavior of the people in relation to the exposition to the sun. In Brazil, the non-melanoma skin cancer is the most incident in the majority of the regions. The dermatoscopy and videodermatoscopy are the main types of examinations for the diagnosis of dermatological illnesses of the skin. The field that involves the use of computational tools to help or follow medical diagnosis in dermatological injuries is seen as very recent. Some methods had been proposed for automatic classification of pathology of the skin using images. The present work has the objective to present a new intelligent methodology for analysis and classification of skin cancer images, based on the techniques of digital processing of images for extraction of color characteristics, forms and texture, using Wavelet Packet Transform (WPT) and learning techniques called Support Vector Machine (SVM). The Wavelet Packet Transform is applied for extraction of texture characteristics in the images. The WPT consists of a set of base functions that represents the image in different bands of frequency, each one with distinct resolutions corresponding to each scale. Moreover, the characteristics of color of the injury are also computed that are dependants of a visual context, influenced for the existing colors in its surround, and the attributes of form through the Fourier describers. The Support Vector Machine is used for the classification task, which is based on the minimization principles of the structural risk, coming from the statistical learning theory. The SVM has the objective to construct optimum hyperplanes that represent the separation between classes. The generated hyperplane is determined by a subset of the classes, called support vectors. For the used database in this work, the results had revealed a good performance getting a global rightness of 92,73% for melanoma, and 86% for non-melanoma and benign injuries. The extracted describers and the SVM classifier became a method capable to recognize and to classify the analyzed skin injuries
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Post dispatch analysis of signals obtained from digital disturbances registers provide important information to identify and classify disturbances in systems, looking for a more efficient management of the supply. In order to enhance the task of identifying and classifying the disturbances - providing an automatic assessment - techniques of digital signal processing can be helpful. The Wavelet Transform has become a very efficient tool for the analysis of voltage or current signals, obtained immediately after disturbance s occurrences in the network. This work presents a methodology based on the Discrete Wavelet Transform to implement this process. It uses a comparison between distribution curves of signals energy, with and without disturbance. This is done for different resolution levels of its decomposition in order to obtain descriptors that permit its classification, using artificial neural networks
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The precision and the fast identification of abnormalities of bottom hole are essential to prevent damage and increase production in the oil industry. This work presents a study about a new automatic approach to the detection and the classification of operation mode in the Sucker-rod Pumping through dynamometric cards of bottom hole. The main idea is the recognition of the well production status through the image processing of the bottom s hole dynamometric card (Boundary Descriptors) and statistics and similarity mathematics tools, like Fourier Descriptor, Principal Components Analysis (PCA) and Euclidean Distance. In order to validate the proposal, the Sucker-Rod Pumping system real data are used
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The Brain-Computer Interfaces (BCI) have as main purpose to establish a communication path with the central nervous system (CNS) independently from the standard pathway (nervous, muscles), aiming to control a device. The main objective of the current research is to develop an off-line BCI that separates the different EEG patterns resulting from strictly mental tasks performed by an experimental subject, comparing the effectiveness of different signal-preprocessing approaches. We also tested different classification approaches: all versus all, one versus one and a hierarchic classification approach. No preprocessing techniques were found able to improve the system performance. Furthermore, the hierarchic approach proved to be capable to produce results above the expected by literature
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Reinforcement learning is a machine learning technique that, although finding a large number of applications, maybe is yet to reach its full potential. One of the inadequately tested possibilities is the use of reinforcement learning in combination with other methods for the solution of pattern classification problems. It is well documented in the literature the problems that support vector machine ensembles face in terms of generalization capacity. Algorithms such as Adaboost do not deal appropriately with the imbalances that arise in those situations. Several alternatives have been proposed, with varying degrees of success. This dissertation presents a new approach to building committees of support vector machines. The presented algorithm combines Adaboost algorithm with a layer of reinforcement learning to adjust committee parameters in order to avoid that imbalances on the committee components affect the generalization performance of the final hypothesis. Comparisons were made with ensembles using and not using the reinforcement learning layer, testing benchmark data sets widely known in area of pattern classification
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Modern wireless systems employ adaptive techniques to provide high throughput while observing desired coverage, Quality of Service (QoS) and capacity. An alternative to further enhance data rate is to apply cognitive radio concepts, where a system is able to exploit unused spectrum on existing licensed bands by sensing the spectrum and opportunistically access unused portions. Techniques like Automatic Modulation Classification (AMC) could help or be vital for such scenarios. Usually, AMC implementations rely on some form of signal pre-processing, which may introduce a high computational cost or make assumptions about the received signal which may not hold (e.g. Gaussianity of noise). This work proposes a new method to perform AMC which uses a similarity measure from the Information Theoretic Learning (ITL) framework, known as correntropy coefficient. It is capable of extracting similarity measurements over a pair of random processes using higher order statistics, yielding in better similarity estimations than by using e.g. correlation coefficient. Experiments carried out by means of computer simulation show that the technique proposed in this paper presents a high rate success in classification of digital modulation, even in the presence of additive white gaussian noise (AWGN)