36 resultados para Geometria diferencial


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This research aims to systematize a proposal of developing a mobile tablet application in order to help implementing the Semantic Differential technique – SD, under the approach of Participatory Design. In 1975, Osgood et al. created the Semantic Differential technique. Since then, many experiments use it to measure the affective perception of individuals concerning objects and concepts by means of compounded scales of bipolar adjectives, based on the theoretical models that support the technique: the conductible, spatial and metric models. During the application of the technique with potential users, the researcher must simultaneously manage several contexts, that is, audio recorder, when authorized, and observe and record spontaneous reports of the respondent. It is noticeable that often occurs a cognitive overload during this event. Thus, the use of a single application whose interface is assigned to its users and respondents could assist researchers in applying the SD technique. This research aimed to understand the processes inherent to the task of implementing the Semantic Differential technique and obeyed the following steps: a) training of users, b) background questionnaire c) interview with Focus Group, and d) cooperative evaluation. Besides these procedures, one can also observe the degrees of facilitation or difficulty concerning the use of the conventional model, which is the development and application of scales with the aid of printed material, pencil, pens, clipboards, and recorder software for editing the document and data analysis. This paper comprises reactions and impressions from the experiences of users of SD technique. Considering the data recollected from the user’s observation, the hypothesis of the experiment proved to be right. It means that the development of the application for mobile tablet employing the technique of Semantic Differential is viable, since it assembles all the steps in one only tool, increases the accomplishment of the task between user/researcher and user/respondent resulting in their mutual satisfaction.

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This dissertation is a research based on the Meaningful Learning Theory, with students from the second year of High School, in the city named Capinzal do Norte, state of Maranhão. The pedagogic approach of this research focuses on what to do and how to do so students can better grasp knowledge inherent to the Euclidean Special Geometry in a more meaningful and changing way, also that information may be kept longer in their brain, so it can last longer in the present and future. The methodological strategy adopted was the research-action, followed by the constant observance of a researcher on the matter with the purpose to ensure consistent results, which come from the use of a variety of data collector instruments, such as: Concept Maps, manipulatives, educational softwares and application of evaluative tests, besides the observations made throughout the process of investigation and the diagnosis itself. It is all due to the fact that we rely on the premise that knowledge is assimilated in particular and idiosyncratic ways, which means each and every student learns in different ways and in different periods of time. That is why it is so important to develop diversified methodologies to the same subject. This research adds to the other ones related to the theoretical frameworks of the Meaningful Learning Theory, of Concept Maps, of the use of technology on the educational process and of manipulatives, which purpose is to connect their common dots. This pedagogical intervention also focuses on the construction of the educational orientations with applicability directly on class, directed specially by the Mathematics teacher of the basic education, who might use them during your teaching practice. Such guidelines established here as an educational product aim to follow the Theory's assumptions that serves as basis to this research, thus becoming an educational element with a relevant significance. The results, with which we are faced, proved overwhelming to the proposed objectives in terms of learning, which were evident in the construction of Conceptual Maps, as well as in the use of Concrete Materials, in addition to serving as a motivational element to participating students of research. The results obtained are indeed reliable in terms of learning, considered the expected goals, and made us certain that the way we have approached the subject is consistent with a holistic education and that at the same time values the tiniest details, which are fundamental to all the learning-teaching process.

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Chromobacterium violaceum is a free-living bacillus, Gram-negative commonly found in water and sand of tropical and subtropical regions. One of its main characteristic it's the ability to produce the purple pigment named violacein, that shows countless biological activities. In 2003, the genome of this organism was totally sequenced and revealed important informations about the physiology of this bacteria. However, few post-genomics studies had been accomplished. This work evaluated the protein profile of C. violaceum cultivated in LB medium at 28ºC that allowed the identification and characterization of proteins related to a possible secretion system that wasn't identified and characterized yet in C. violaceum, to the quorum sensing system, to regulatory process of transcription and translation, stress adaptation and biotechnological potential. Moreover, the response of the bacteria to UVC radiation was evaluated. The comparison of the protein profile, analyzed through 2-D electrophoresis, of the control group versus the treatment group allowed the identification of 52 proteins that arose after stress induction. The obtained results enable the elaboration of a stress response pathway in C. violaceum generated by the UVC light. This pathway, that seems to be a general stress response, involves the expression of proteins related to cellular division, purine and pirimidine metabolism, heat chock or chaperones, energy supply, regulation of biofilm formation, transport, regulation of lytic cycle of bacteriophages, besides proteins that show undefined function. Despite the response present similarities with the classic SOS response of E. coli, we still cannot assert that C. violaceum shows a SOS-like response, mainly due to the absence of characterization of a LexA-like protein in this organism

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The β-proteobacterium Chromobacterium violaceum is a Gram-negative, free-living, saprophytic and opportunistic pathogen that inhabits tropical and subtropical ecosystems among them, in soil and water of the Amazon. It has great biotechnological potential, and because of this potential, its genome was completely sequenced in 2003. Genome analysis showed that this bacterium has several genes with functions related to the ability to survive under different kinds of environmental stresses. In order to understand the physiological response of C. violaceum under oxidative stress, we applied the tool of shotgun proteomics. Thus, colonies of C. violaceum ATCC 12472 were grown in the presence and absence of 8 mM H2O2 for two hours, total proteins were extracted from bacteria, subjected to SDS-PAGE, stained and hydrolysed. The tryptic peptides generated were subjected to a linear-liquid chromatography (LC) followed by mass spectrometer (LTQ-XL-Orbitrap) to obtain quantitative and qualitative data. A shotgun proteomics allows to compare directly in complex samples, differential expression of proteins and found that in C. Violaceum, 131 proteins are expressed exclusively in the control condition, 177 proteins began to be expressed under oxidative stress and 1175 proteins have expression in both conditions. The results showed that, under the condition of oxidative stress, this bacterium changes its metabolism by increasing the expression of proteins capable of combating oxidative stress and decreasing the expression of proteins related processes bacterial growth and catabolism (transcription, translation, carbon metabolism and fatty acids). A tool with of proteomics as an approach of integrative biology provided an overview of the metabolic pathways involved in the response of C. violaceum to oxidative stress, as well as significantly amplified understanding physiological response to environmental stress. Biochemical and "in silico" assays with the hypothetical ORF CV_0868 found that this is part of an operon. Phylogenetic analysis of superoxide dismutase, protein belonging to the operon also showed that the gene is duplicated in genome of C. violaceum and the second copy was acquired through a horizontal transfer event. Possibly, not only the SOD gene but also all genes comprising this operon were obtained in the same manner. It was concluded that C. violaceum has complex, efficient and versatile mechanisms in oxidative stress response

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Human mesenchymal stem cells (MSC) are powerful sources for cell therapy in regenerative medicine. The long time cultivation can result in replicative senescence or can be related to the emergence of chromosomal alterations responsible for the acquisition of tumorigenesis features in vitro. In this study, for the first time, the expression profile of MSC with a paracentric chromosomal inversion (MSC/inv) was compared to normal karyotype (MSC/n) in early and late passages. Furthermore, we compared the transcriptome of each MSC in early passages with late passages. MSC used in this study were obtained from the umbilical vein of three donors, two MSC/n and one MSC/inv. After their cryopreservation, they have been expanded in vitro until reached senescence. Total RNA was extracted using the RNeasy mini kit (Qiagen) and marked with the GeneChip ® 3 IVT Express Kit (Affymetrix Inc.). Subsequently, the fragmented aRNA was hybridized on the microarranjo Affymetrix Human Genome U133 Plus 2.0 arrays (Affymetrix Inc.). The statistical analysis of differential gene expression was performed between groups MSC by the Partek Genomic Suite software, version 6.4 (Partek Inc.). Was considered statistically significant differences in expression to p-value Bonferroni correction ˂.01. Only signals with fold change ˃ 3.0 were included in the list of differentially expressed. Differences in gene expression data obtained from microarrays were confirmed by Real Time RT-PCR. For the interpretation of biological expression data were used: IPA (Ingenuity Systems) for analysis enrichment functions, the STRING 9.0 for construction of network interactions; Cytoscape 2.8 to the network visualization and analysis bottlenecks with the aid of the GraphPad Prism 5.0 software. BiNGO Cytoscape pluggin was used to access overrepresentation of Gene Ontology categories in Biological Networks. The comparison between senescent and young at each group of MSC has shown that there is a difference in the expression parttern, being higher in the senescent MSC/inv group. The results also showed difference in expression profiles between the MSC/inv versus MSC/n, being greater when they are senescent. New networks were identified for genes related to the response of two of MSC over cultivation time. Were also identified genes that can coordinate functional categories over represented at networks, such as CXCL12, SFRP1, xvi EGF, SPP1, MMP1 e THBS1. The biological interpretation of these data suggests that the population of MSC/inv has different constitutional characteristics, related to their potential for differentiation, proliferation and response to stimuli, responsible for a distinct process of replicative senescence in MSC/inv compared to MSC/n. The genes identified in this study are candidates for biomarkers of cellular senescence in MSC, but their functional relevance in this process should be evaluated in additional in vitro and/or in vivo assays

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As most current studies, reinforced plastics have been, in recent years, a viable alternative in building structural elements of medium and large, since the lightness accompanied by high performance possible. The design of hybrid polymer composites (combination of different types of reinforcements) may enable structural applications thereof, facing the most severe service conditions. Within this class of composite materials, reinforced the underlying tissues hybrid high performance are taking space when your application requires high load bearing and high rigidity. The objective of this research work is to study the challenges in designing these fabrics bring these materials as to its mechanical characterization and fracture mechanisms involved. Some parameters associated with the process and / or form of hybridization stand out as influential factors in the final performance of the material such as the presence of anisotropy, so the fabric weave, the process of making the same, normative geometry of the specimens, among others. This sense, four laminates were developed based hybrid reinforcement fabrics involving AS4 carbon fiber, kevlar and glass 49-E as the matrix epoxy vinyl ester resin (DERAKANE 411-350). All laminates were formed each with four layers of reinforcements. Depending on the hybrid fabric, all the influencing factors mentioned above have been studied for laminates. All laminates were manufactured industrially used being the lamination process manual (hand-lay-up). All mechanical characterization and study of the mechanism of fracture (fracture mechanics) was developed for laminates subjected to uniaxial tensile test, bending in three and uniaxial compression. The analysis of fracture mechanisms were held involving the macroscopic, optical microscopy and scanning electron microscopy