Implementação de rotinas computacionais básicas para cabeça estéreo robótica

O Laboratório de Sistemas Inteligentes do Departamento de Engenharia de Computação e Automação da Universidade Federal do Rio Grande do Norte - UFRN -tem como um de seus projetos de pesquisa -Robosense -a construção de uma plataforma robótica móvel. Trata-se de um robô provido de duas rodas, acionadas de forma diferencial, dois braços, com 5 graus de liberdade cada, um cinturão de sonares e uma cabeça estéreo. Como objetivo principal do projeto Robosense, o robô deverá ser capaz de navegar por todo o prédio do LECA, desviando de obstáculos. O sistema de navegação do robô, responsável pela geração e seguimento de rotas, atuará em malha fechada. Ou seja, sensores serão utilizados pelo sistema com o intuito de informar ao robô a sua pose atual, incluindo localização e a configuração de seus recursos. Encoders (sensores especiais de rotação) foram instalados nas rodas, bem como em todos os motores dos dois braços da cabeça estéreo. Sensores de fim-de-curso foram instalados em todas as juntas da cabeça estéreo para que seja possível sua pré-calibração. Sonares e câmeras também farão parte do grupo de sensores utilizados no projeto. O robô contará com uma plataforma composta por, a princípio, dois computadores ligados a um barramento único para uma operação em tempo real, em paralelo. Um deles será responsável pela parte de controle dos braços e de sua navegação, tomando como base as informações recebidas dos sensores das rodas e dos próximos objetivos do robô. O outro computador processará todas as informações referentes à cabeça estéreo do robô, como as imagens recebidas das câmeras. A utilização de técnicas de imageamento estéreo torna-se necessária, pois a informação de uma única imagem não determina unicamente a posição de um dado ponto correspondente no mundo. Podemos então, através da utilização de duas ou mais câmeras, recuperar a informação de profundidade da cena. A cabeça estéreo proposta nada mais é que um artefato físico que deve dar suporte a duas câmeras de vídeo, movimentá-las seguindo requisições de programas (softwares) apropriados e ser capaz de fornecer sua pose atual. Fatores como velocidade angular de movimentação das câmeras, precisão espacial e acurácia são determinantes para o eficiente resultado dos algoritmos que nesses valores se baseiam

Modelos analíticos para rádio fontes extragalácticas

The great majority of analytical models for extragalactic radio sources suppose self-similarity and can be classified into three types: I, II and III. We have developed a model that represents a generalization of most models found in the literature and showed that these three types are particular cases. The model assumes that the area of the head of the jet varies with the jet size according to a power law and the jet luminosity is a function of time. As it is usually done, the basic hypothesis is that there is an equilibrium between the pressure exerted both by the head of the jet and the cocoon walls and the ram pressure of the ambient medium. The equilibrium equations and energy conservation equation allow us to express the size and width of the source and the pressure in the cocoon as a power law and find the respective exponents. All these assumptions can be used to calculate the evolution of the source size, width and radio luminosity. This can then be compared with the observed width-size relation for radio lobes and the power-size (P-D) diagram of both compact (GPS and CSS) and extended sources from the 3CR catalogue. In this work we introduce two important improvement as compared with a previous work: (1)We have put together a larger sample of both compact and extended radio sources

Estudo imuno-histoquímico da presença de miofibroblastos e da expressão do fator transformador de crescimento-beta1, interferon gama, metaloproteinase de matriz 13 e indutor de metaloproteinases de matriz em lesões odontogênicas epiteliais

Myofibroblasts are cells that exhibit a hybrid phenotype, sharing the morphological characteristics of fibroblasts and smooth muscle cells, which is acquired during a process called differentiation. These cells then start to express -SMA, a marker that can be used for their identification. Studies suggest that myofibroblasts are related to the aggressiveness of different tumors and that TGF-1 and IFN- play a role in myofibroblast differentiation, stimulating or inhibiting this differentiation, respectively. The objective of this study was to investigate the role of myofibroblasts in epithelial odontogenic tumors, correlating the presence of these cells with the aggressiveness of the tumor. Immunohistochemistry was used to evaluate the expression of TGF-1 and IFN- in myofibroblast differentiation, as well as the expression of MMP-13, which is activated by myofibroblasts, and of EMMPRIN (extracellular matrix metalloproteinase inducer) as a precursor of this MMP. The sample consisted of 20 solid ameloblastomas, 10 unicystic ameloblastomas, 20 odontogenic keratocysts, and 20 adenomatoid odontogenic tumors. For evaluation of myofibroblasts, anti- -SMA-immunoreactive cells were quantified in connective tissue close to the epithelium. Immunoexpression of TGF-1, IFN-, MMP-13 and EMMPRIN was evaluated in the epithelial and connective tissue components, attributing scores of 0 to 4. The results showed a higher concentration of myofibroblasts in solid ameloblastomas (mean of 30.55), followed by odontogenic keratocysts (22.50), unicystic ameloblastomas (20.80), and adenomatoid odontogenic tumors (19.15) (p=0.001). No significant correlation between TGF-1 and IFN- was observed during the process of myofibroblast differentiation. There was also no correlation between the quantity of myofibroblasts and MMP-13 expression. Significant correlations were found between MMP-13 and TGF-1 (r=0.087; p=0.011), between MMP- 13 and IFN- (r=0.348; p=0.003), as well as between EMMPRIN and MMP-13 (r=0.474; p<0.001) and between EMMPRIN and IFN- (r=0.393; p=0.001). The higher quantity of myofibroblasts observed in solid ameloblastomas, odontogenic keratocysts and unicystic ameloblastomas suggests that these cells are one of the factors responsible for the more aggressive biological behavior of these tumors, although the myofibroblast population was not correlated with TGF-1, IFN-, MMP-13 or EMMPRIN. The correlation between MMP- 13 and TGF-1 suggests that the latter induces the expression of this metalloproteinase. The present results also support the well-established role of EMMPRIN as an inducer of MMP-13. Furthermore, the relationship between EMMPRIN and IFN- and between MMP-13 and IFN- suggests synergism in the antifibrotic effect of these markers

Caracterização Morfodinâmica e Sedimentologia da Plataforma Continental Rasa na APA Estadual dos Recifes de Corais - RN

This study had to aimed to characterize the sediments of shallow continental shelf and realize the mapping of features visible for satellite images by using remote sensing techniques, digital image processing and analysis of bathymetry between Maxaranguape and Touros - RN. The study s area is located in the continental shallow shelf of Rio Grande do Norte, Brazil, and is part of the Environmental Protection Area (APA) of Coral Reefs. A total of 1186 sediment samples were collected using a dredge type van veen and positioning of the vessel was made out with the aid of a Garmin 520s. The samples were treated In the laboratory to analyze particle size of the sediment, concentration of calcium carbonate and biogenic composition. The digital images from the Landsat-5 TM were used to mapping of features. This stage was used the band 1 (0,45-1,52 μm) where the image were georeferenced, and then adjusting the histogram, giving a better view of feature bottom and contacts between different types of bottom. The results obtained from analysis of the sediment showed that the sediments of the continental shelf east of RN have a dominance of carbonate facies and a sand-gravelly bottom because the region is dominated by biogenic sediments, that are made mainly of calcareous algae. The bedform types identified and morphological features found were validated by bathymetric data and sediment samples examined. From the results obtained a division for the shelf under study is suggested, these regions being subdivided, in well characterized: (1) Turbid Zone, (2) Coral Patch Reefs Zone, (3) Mixed Sediments Carbonates Zone, ( 4) Algae Fouling Zone, (5) Alignment Rocky Zone, (6) Sand Waves Field (7) Deposit siliciclastic sands

Pesca artesanal entre mudanças socioambientais: estudo de caso na APA Bonfim-Guaraíra/RN-Brasil

Artisanal fishing is one of the important economic activities of Rio Grande do Norte (RN), becoming the main form of survival and income for many families. The southern coast of RN has strong fishing tradition, both in exploitation of fish as in the collection of mollusks on the banks of Guaraíra Lagoon (APA Bonfim-Guaraíra). In recent years, fishing communities have become more vulnerable to outside influences, since the socio-economic and environmental changes are exposed. These changes require adjustments to the fishermen to different environmental conditions, as the social and natural systems are driven by reorganization and upgrading processes. The living conditions in fishing communities are objective and necessary in different ways, according to a selection that is cultural, so adaptable. This study has the general objective to analyze the main environmental changes in fishing communities, based on the understanding of fishermen and mollusk fisherwomen about this problem. The specific objectives searched to: describe the socioeconomic profile, prospects and difficulties of fishermen and mollusk fisherwomen; investigate the major social and environmental changes in the fishing communities of Patané and Camocim (Arez/RN). The methodology was qualitative-quantitative with the techniques of observation in the field and open and semistructured interviews applied to representatives of Cologne fishing, fishermen and mollusk fisherwomen. Between the months of January to July 2014 were applied semistructured interviews with 41 interlocutors in Patané and 23 of Camocim; totaling 64 people. The results indicated that the interlocutors are aged 40 to 60 years; have only completed elementary school level; are married and have children; survive on less than a minimum wage income and they are not receiving employment insurance. The case study also revealed that the socioeconomic and environmental problems reflected in changes in reproduction, organization and social division of labor, which generates adaptive changes of families to external influences, resulting directly from other economic activities and market pressure and indirectly from tourism. Therefore, adaptations to changes scenario presented as favorable to economic aspects and unfavorable to the social and environmental aspects. In short, the fishery develops on technical, bureaucratic and financial obstacles, in the everyday needs of men and women is the determining factor in willingness to continue exercising fishing and shell fishing on Guaraíra Lagoon, space representing relations social, practices and customs transmitted in the course of local history through social memory of the oldest to the youngest.

Áreas importantes para a conservação do último grande herbívoro da caatinga potiguar: o veado-catingueiro (Mazama gouazoubira)

Cervídeo Mazama gouazoubira é a espécie de veado que possui maior distribuição dentre as espécies sul americanas. Aspectos da vegetação, predação, competição, caça e perda de habitat são fatores importantes para compreender a distribuição espacial de herbívoros na paisagem. Dessa forma, considerando a falta de estudos de mamíferos de médio e grande porte na Caatinga, objetivamos compreender quais os fatores ambientais e antrópicos que influenciam a ocupação do veado-catingueiro (M. gouazoubira) na região semiárida do estado do Rio Grande do Norte, Brasil. O estudo foi realizado em 10 áreas amostrais e utilizamos armadilhas fotográficas para amostragem e modelos de ocupação foram construídos representando nossas hipóteses biológicas. Os modelos foram ranqueados através dos valores obtidos do AIC. As variáveis cobertura vegetal de caatinga e densidade da vegetação mostraram maior efeito, já a caatinga arbórea mostrou um efeito menor, sugerindo que a espécie é altamente dependente da vegetação para ocorrer, possuindo menor dependência de caatinga arbórea. Esperamos que nossos resultados possam ser utilizados como suporte para planos de manejo e criação de novas unidades de conservação no estado.