Navegando por Data de Publicação, começando com "2011-08-26"

Filtrar resultados por ano ou mês

Agora exibindo 1 - 9 de 9

Filtragem MAP 2-D de imagens CT ruidosas
(Universidade Federal de São Carlos, 2011-08-26) Geraldo, Rafael José; Mascarenhas, Nelson Delfino d'Ávila; https://lattes.cnpq.br/0557976975338451; https://lattes.cnpq.br/6243571041189627
Computed tomography has been widely used for medical diagnosis, since it allows viewing of internal parts of a body without overlapping structures. However, recent studies indicate a certain risk of cancer to the patients who undergo this type of examination due the radiation dose to which they are exposed. The purpose of this work is to develop new _ltering techniques in the CT image space, in order to provide a better quality to the images acquired with low radiation exposure to the patient. For noise reduction, a new denoising technique is developed based on a pointwise Maximum a Posteriori (MAP). The noise is considered Gaussian with zero mean, as observed experimentally, and the variance is estimated considering two cases: signaldependent noise and signal-independent noise. For the a priori density of the signal, we used di_erent non-negative probability densities (re_ecting the fact the pixels of an image are non-negative). In another approach, the histogram of the images were segmented into unimodal parts and each segment was _ltered using the _lter based on the MAP criterion with the a priori density that best _ts it. After _ltering, the evaluation of the method is performed using the following criteria: Mean Square Error, Improvement in Signal to Noise Ratio, Universal Image Quality Index and Structural Similarity Index. The 2D _ltering results are compared with the results obtained by pointwise Wiener _lter.
Processos linguísticos na produção de textos: mecanismos de qualificação e relações intersubjetivas
(Universidade Federal de São Carlos, 2011-08-26) Barros, Solange Christiane Gonzalez; Onofre, Marilia Blundi; https://lattes.cnpq.br/4908382415301882; https://lattes.cnpq.br/3171777102805120
This research intends to approach the language teaching and learning from an enunciative perspective based on the Theory of Predicative and Enunciative Operations from Antoine Culioli. Our theoretical option is due to the fact we take into consideration the relevance of working with the articulation between grammatical marks and text production/understanding. With the purpose of this achievement, we study the notion of qualification conveyed by different grammatical marks for which this role is traditionally ascribed. It is included, for example, adjectives, adjective locutions and adjective sentences. We are mainly interested in the processes of predication that involves this notion as we aim to show that these processes are evidences for intersubjectivity marks which uphold these productions of meaning. We also propose to demonstrate that this teaching approach for grammatical marks articulated with the semantic and discursive notions is a way to promote the linguistic and cognitive development in students.
Hidrólise e fermentação do bagaço de cana-de-açúcar em escala de bancada para produção de etanol 2G
(Universidade Federal de São Carlos, 2011-08-26) Carli, Chanel Moacyr de; Cruz, Antonio José Gonçalves da; https://lattes.cnpq.br/3863506440644207
The objective of this work was to evaluate the hydrolysis and alcoholic fermentation stages of the sugar cane bagasse (SCB) for second generation ethanol production (2G). Hydrolysis experiments were carried out employing 8%, 10%, 15% and 20% (m/v) solid loads. Samples of in natura SCB and steam exploded SCB were submitted to different pretreatment sequences: water + 4.0% NaOH solution; 1.0% H2SO4 solution + 4.0% NaOH 4%; 1.0% H2SO4 solution + 7.0% NaOH solution; 7.0% NaOH solution; aqueous ammonia; water. Pretreated bagasse was characterized (chemical analysis and SEM) and the mass yield of each sequence was evaluated. This material was employed in hydrolysis experiments using different enzyme loads (33, 65 and 98 FPU/g-cellulose). Three different configurations were evaluated: SHF Separated Saccharification and Fermentation, SSF Simultaneous Hydrolysis and Fermentation, and FB Fed-Batch. In these experiments it was employed Accelerase 1500 enzymatic extract (Genencor). Concerning cellulose loss, SCB pretreated with water and 4.0% of NaOH solution presented the best result (23.9%). For this case, the hemicellulose and ligning removal was 73.7% and 79.1%, respectively. For the others pretreatment sequences the hemicellulose and lignin removal range from 72.3 to 92.2%. For lignin removal the values range from 60.0 and 88.9%. Experiments employing high solid load (20%) resulting in a more concentrated hydrolyzed (ca. 110 g/L). In this experiment it was achieved 64% of cellulose to glucose conversion in 34 hour. The fermentation experiments were carried out employing Saccharomyces cerevisiae yeast (lyophilized commercial). The yield ranges from 75 to 94%. Experiment conducted in the SSF configuration achieved 86.5% of cellulose to ethanol conversion in 14 hours. Experiment carried out in SHF configuration achieved 63.2% of cellulose to ethanol conversion in 37 hours. Experiments carried out in FB configuration reached larger amount of glucose with the same enzyme load employed in batch experiment and at the same time.
Proposta de sistema para a gestão da qualidade e da segurança de vegetais minimamente processados
(Universidade Federal de São Carlos, 2011-08-26) Alvarenga, André Luis Bonnet; Toledo, José Carlos de; https://lattes.cnpq.br/9421627326330417; https://lattes.cnpq.br/3555912710
The global need to ensure food quality and safety has always been a concern of primary producers, processors, distributors, consumers and governmental bodies. On the other hand, notified cases of food borne disease still cause a wide range of negative social and economic impacts worldwide. Current technology for production of Minimally Processed Vegetables (MPV) entails a series of critical steps, which can lead to product contamination by biological, chemical or physical hazards if adequate controls are not observed, and yielding potentially unsafe food products. Such concerns become even more important given that MPV`s production chains involve mostly small producers and/or enterprises in rural settings, which typically lack qualified training and specific skills. To address this challenge, the present work proposes a customized quality and safety management system for MPVs. Initially, an integrative literature search was conducted to cover topics such as quality management theory, food safety systems, MPV technology, and supply chain management as an initial step to direct a multiple case study. Field work was then performed for two MPV chains, involving a total of 18 observation units composed of rural producers, processors, shippers and distributors for retail or institutional markets, so that the system could be developed to meet the actual needs and requirements of MPV chains. Its guiding principle is the management of quality attributes of MPVs, as demanded by consumers, via the operational implications of these attributes throughout the production chain. The system also includes a performance evaluation protocol to ensure continuous process optimization. As a result, the system´s structure operates at a simple managing level, triggering systemic process vision and effective cooperation among stakeholders, while empowering them by their direct leadership and coordination of the system and ensuing processes. Finally, a working model for the proposed system is applied to minimally processed lettuce. In addition to being a tool to plan the implementation of quality and safety management protocols in this specific MPV chain, the system can also be used by MPV processors as a mainframe to guide their internal and supplier´s audits, as well as by retail and institutional companies.
Estudo de interações proteicas da Tiorredoxina Peroxidase Nuclear (nTPx) de Sacharomyces cerevisiae nos eventos de crescimento celular e silenciamento telomérico
(Universidade Federal de São Carlos, 2011-08-26) Breyer, Carlos Alexandre; Oliveira, Marcos Antonio de; https://lattes.cnpq.br/7187775781809988
The thioredoxin peroxidase (Tpx) is a group of antioxidant proteins that has been widely studied due to its role in the decomposition of different peroxides such as H2O2, peroxynitrite and organic peroxides. The ability of peroxide decomposition by Tpx is related to the presence of a conserved cysteine called peroxidatic cysteine (CysP). Most Tpx has a second cysteine (resolving cysteine - CysR) which forms a disulfide with CysP after peroxide decomposition. In addition to the peroxidase activity, some Tpx have molecular chaperone activity and are also involved in signaling of cell growth induced by hydroperoxides. It has been demonstrated that the Tpx cytosolic isoform of Schizosaccharomyces pombe is able to interact directly with MAPK (Sty1) via mixed disulfide, which is stabilized when the CysR is replaced by a serine residue. Saccharomyces cerevisiae have a nuclear isoform of Tpx (nTPx) and review of the literature shows the importance of this protein in maintaining the telomere silencing and decomposition of organic peroxides in the nucleus. Scale proteomic studies using mass spectrometry and two-hybrid indicate the nTPx association with MAP kinases. However, despite its location and participation in biological processes of relevance, works related to nTPx are scarce. Scale proteomics studies reported the physical interaction between nTPx and Mec3, Gts1, Pc1 and Dog2. These proteins are related to cell signaling or maintenance of telomeric silencing. However, no specific studies were performed to confirm these interactions and if they are established by mixed disulfides. This study aimed to evaluate the interactions previously described in the literature between nTPx and Mec3, Pcl1, Dog2 and Gts1 through the expression and purification of these proteins and in vitro evaluation of interactions as well as in vivo tests using two-hybrid. Several efforts were made with different approaches, nevertheless it was impossible overexpression of Mec3, Pcl1, Dog2, indicating a toxic effect of these proteins on the strains used. Furthermore, we found great success in overexpression of nTPx and nTpxC112S (8 mg and 10 mg per liter of cell culture) in Eschericchia coli strain BL21 (DE3) C43. This is the first time that these proteins were expressed in native form. It was also possible to overexpress the Gts1 protein in the same strain. These results could lead for new approaches in future studies in order to determine these threedimensional structures, by methods such as X-ray crystallography or nuclear magnetic resonance (NMR). Finally, the results obtainedusing the technique of two-hybrid yeast confirmed the interaction in vivo among nTPx and Mec3, Gts1, Dog2. However, opposing the results described in the literature, no interaction was detected between nTPx and PCL1, emphasizing the necessity of specific experiments in addition to the large-scale ones.
Uso de instrumentos de avaliação de riscos ergonômicos: teoria e prática
(Universidade Federal de São Carlos, 2011-08-26) Souza, Viviani Cintra de; Camarotto, João Alberto; https://lattes.cnpq.br/1427853773681255; https://lattes.cnpq.br/2583628524362262
In recent years, in Brazil, companies have shown a growing interest in developing actions to address ergonomic problems in working conditions related to health and productivity. This interest is due in part to the compliance requirements of working conditions to the legislation of the Ministry of Labor and Employment. To adapt working conditions to the legal conditions recommended the need arises to measure the conditioning factors of work activities, and consequently increases the demand for use of instruments to assess the ergonomic risks. The study aims to determine the contribution of risk assessment tools in the analysis of ergonomic conditions of work activity in steps of Ergonomic Work Analysis and use of these instruments in Brazil, by consulting firms and research institutions and extension in the area ergonomics in an attempt to establish the relationship between the objectives and content of the instruments and methods of analysis used in practice. The survey was conducted through a literature review, to determine the instruments and through a questionnaire, seeking, knowing the tools most used by Brazilian organizations to ergonomics. In the questionnaire some questions were addressed in order to know the work of organizations of ergonomics in Brazil: issues relating to training for professionals working with ergonomics, the main intervention activities and steps that develop, the factors related to the job consider during the intervention, the methodologies we use as reference and the instruments they use to ergonomic risk assessments. According to the systematic knowledge and accumulated in the literature on the use of tools to verify specific aspects of man's relationship with their work environment, it was observed that most concentrate their goals in the evaluation of factors related to the physical dimensions of the work. The research results allow us to conclude that the instruments are not sufficient to analyze the work during an ergonomic intervention. Thus, the formation of analysts with their different views and
Desenvolvimento de procedimentos metodológicos na prospecção de microalgas propícias para a produção de biodiesel
(Universidade Federal de São Carlos, 2011-08-26) Pepino, Rodrigo Fernando; Vieira, Armando Augusto Henriques; https://lattes.cnpq.br/4428377384377272; https://lattes.cnpq.br/1295111902750887
The chemical compounds called triacylglycerides (TAGs) have been the main source for biodiesel. The isolation of high lipid yield microalgae is important for the success of algae biomass production for biodiesel and, therefore, a search not only for organisms that fulfill such profile, but also for techniques effective in rapid lipid detection is fundamental. A number of methodologies on the characterization of microalgae lipid production, such as FTIR and RMN spectroscopy and spectrofluorimetry using the Nile Red dye are presented in this study. The Fourier Transform Infrared Spectroscopy (FTIR) technique have been largely used in biological system studies due to its rapid analysis, no pretreatment data gathering and easy biochemical characterization of intact cells. This study proposes a technical optimization of the FTIR technique for microalgae usage purposes as a practical approach for concomitantly prospecting large amounts of microalgae species with focus on biodiesel production. The Red Nile fluorescence has been successfully applied in microalgae lipid determination. In this research, the lipid (neutral) amount was determined by fluorescence in 430-570nm and a linear correlation established with the data gathered through gravimetry. After prospecting a number of species from the laboratory s stock cultures, the freshwater microalgae Scenedesmus sp (Clone MJ13) has been selected for study under traditional growth practices and under conditions of different nitrogen and phosphorus concentrations. The results showed a fast metabolic answer of Scenedesmus sp to the nutritional availability and the efficiency of the FTIR spectroscopy as a fast and reliable method for the determination of lipid production in a prospecting process.
Istar: um esquema estrela otimizado para Image Data Warehouses baseado em similaridade
(Universidade Federal de São Carlos, 2011-08-26) Anibal, Luana Peixoto; Ciferri, Ricardo Rodrigues; https://lattes.cnpq.br/8382221522817502; https://lattes.cnpq.br/7589638896609246
A data warehousing environment supports the decision-making process through the investigation and analysis of data in an organized and agile way. However, the current data warehousing technologies do not allow that the decision-making processe be carried out based on images pictorial (intrinsic) features. This analysis can not be carried out in a conventional data warehousing because it requires the management of data related to the intrinsic features of the images to perform similarity comparisons. In this work, we propose a new data warehousing environment called iCube to enable the processing of OLAP perceptual similarity queries over images, based on their pictorial (intrinsic) features. Our approach deals with and extends the three main phases of the traditional data warehousing process to allow the use of images as data. For the data integration phase, or ETL phase, we propose a process to represent the image by its intrinsic content (such as color or texture numerical descriptors) and integrate this data with conventional data in the DW. For the dimensional modeling phase, we propose a star schema, called iStar, that stores both the intrinsic and the conventional image data. Moreover, at this stage, our approach models the schema to represent and support the use of different user-defined perceptual layers. For the data analysis phase, we propose an environment in which the OLAP engine uses the image similarity as a query predicate. This environment employs a filter mechanism to speed-up the query execution. The iStar was validated through performance tests for evaluating both the building cost and the cost to process IOLAP queries. The results showed that our approach provided an impressive performance improvement in IOLAP query processing. The performance gain of the iCube over the best related work (i.e. SingleOnion) was up to 98,21%.
Estudo de alterações metabólicas nos fungos endofíticos Penicillium brasilianum e Penicillium griseoroseum
(Universidade Federal de São Carlos, 2011-08-26) Silva, José Vinicius da; Rodrigues Filho, Edson; https://lattes.cnpq.br/3667941735597178; https://lattes.cnpq.br/2434474647454729
Microorganisms, known as being relatively simple, have shown a great adaptation power to different nutritional situations by changing their metabolism with lack or supply of nutrients in the culture medium. This feature allows a wide range of the use of microorganisms to produce metabolites with several interests. This study has been named OSMAC (One Strain Many Compounds) approach, which was applied in this study by using two fungi from Penicillium genus. Through culture medium modification with FeCl3 during growth of P. brasilianum, it was able to produce isoquinolinic alkaloid. On the other hand, the addition of CaCl2, another alkaloid belonging to tremogenic class was isolated and analysed by spectroscopic methods. When P. griseoroseum was cultivated with NH4Br, it was observed the production of a halogenated secondary metabolite, which was not reported before (brominated roquefortine C). Analyses by GC/MS led to detect three phenolic compounds with bromine atoms in its structure. The secondary metabolites of P. griseoroseum with no modification in the culuture medium were studied and three metabolites were isolated. Two of them belong to the tetronic acid class and the other one was isolated as a dimer from clavatol. Analyses by LC/ MS-MS were able to identify other tetronic acids in the ethyl acetate extract from P. griseoroseum.