Os hormônios glicocorticóides causam uma completa reversão tanto \"in vitro\" quanto \"in vivo\" do fenótipo tumoral para normal, na linhagem celular ST1 de glioma de rato (Armelin & Armelin, 1983) que é um variante da linhagem C6 de glioma de rato. Neste trabalho, foram construídas bibliotecas normalizadas de cDNAs subtraídos e normalizadas, através da metodologia de PCR supressivo, para identificar genes regulados por glicocorticóides, potencialmente envolvidos na reversão fenotípica de células ST1. A construção e análise de duas bibliotecas de cDNAs subtraídos, permitiu o isolamento de 7 genes diferencialmente expressos, alguns dos quais são conhecidos efetores do controle da proliferação celular e/ou diferenciação: trombospondina-1, ciclina G, tirosina fosfatase CL100 e NRP/B. Foi isolado, também, um clone similar a tenascina-X, que apresenta um transcrito de tamanho diferente. O isolamento e caracterização de um cDNA completo correspondente a esse transcrito revelou que é constituído apenas por motivos de fibronectina tipo III e fibrinogênio. A dramática indução deste transcrito por hidrocortisona sugere um papel potencial para esse variante de TN-X no controle da proliferação celular. A análise da expressão destes genes em células P7, um variante de C6 que não sofre reversão fenotípica mediada com glicocorticóides, e em células U87 de glioblastoma humano, revelou que são expressos em níveis muito baixos ou indetectáveis, nestas células indicando que o produto destes genes pode ter um papel importante na reversão fenotípica tumoral-normal. A prevalência de transcritos raros e diferencialmente expressos nestas bibliotecas, mostra que são adequadas para o rastreamento, através de métodos automatizados de microarranjos de DNA, para a validação de clones diferencialmente expressos, podendo revelar, rapidamente, um painel de genes candidatos a estarem envolvidos nas respostas anti-proliferativa e anti-tumoral dos glicocorticóides. / Treatment of the C6 rat glioma cell variant, ST1 cells, with glucocorticoids, leads to a complete reversion of their transformed phenotype and loss of tumorigenic potential. In this work, two subtracted and equalized cDNA libraries were constructed, based on suppressive PCR, in order to identify glucocorticoid-regulated genes related to the ST1 phenotypic reversion. Analysis of both subtracted cDNA libraries revealed 7 differentially expressed genes, some of which are well known negative growth regulators: thrombospondin-1, cyclin G, tyrosine phosphatase CL 100 and NRP/B. In addition, a cDNA clone similar to TN-X, but exibiting a different transcript size was also isolated. Isolation and characterization of a full-length cDNA corresponding to this transcript, revealed that it is composed of fibronectin type III repeats and one single fibrinogen domain. Glucocorticoid induction of this transcript may suggest a different role of TN-X variants in controling cell proliferation. Expression analysis of the C6-derived glucocorticoid-resistant, P7 variant, and of the human glioblastoma U87 cells, revealed very low or undectable levels of these transcripts, further suggesting that their expression is related to the ST1 cells\' phenotypic reversion. Prevalence of rare and differentially expressed transcripts in these libraries suggests that they are likely to be useful in automated systems (DNA microarrays) to rapidly validate differentially expressed clones and to reveal a panel of candidate genes that mediate the anti-proliferative and anti-tumor effects of glucocorticoids.

No description available.

Este trabalho tem a finalidade de apresentar e comparar técnicas de redução de ruído utilizando como critérios de avaliação a mínima distorção espectral e a redução de ruído, na reconstrução dos sinais de voz degradados por ruído. Para tanto, utilizou-se os filtros de Kalman de tempo discreto e de freqüência discreta em conjunto com a técnica de subtração espectral de potência. Os sinais utilizados foram contaminados por ruídos branco e colorido, e a avaliação do desempenho dos algoritmos foi realizada tendo-se como parâmetros a relação sinal/ruído segmentada (SNRseg) e a distância de Itakura-Saito (d(a,b)). Após o processamento, verificou-se que a técnica, proposta neste trabalho, de filtragem de Kalman no tempo em conjunto com a subtração espectral de potência, apresentou resultados um pouco melhores em relação à filtragem de Kalman na freqüência em conjunto com a subtração espectral de potência. / This work has as main objective to present and to compare techniques of noise reduction using as evaluation criterion the low spectral distortion and the noise reduction in the reconstruction of corrupted speech signals. For so much, it was used the Kalman\'s filters in the time and frequency domain together with the technique of power spectral subtraction. The used signals were corrupted by white and colored noises and the evaluation of effectiveness of the algorithms was accomplished using the segmental signal-to-noise ratio (SNRseg) and the Itakura-Saito distance (d(a,b)). After the processing, it was noticed that the Kalman filtering in the time together with power spectral subtraction presented better results than the Kalman filtering in the frequency together with power spectral subtraction.

While railroad trespassing is a dangerous activity with significant security and safety risks, regular patrolling of potential trespassing sites is infeasible due to exceedingly high resource demands and personnel costs. There is thus a need to design an automated trespass detection and early warning prediction tool leveraging state-of-the-art machine learning techniques. Leveraging video surveillance through security cameras, this thesis designs a novel approach called ARTS (Automated Railway Trespassing detection System) that tackles the problem of detecting trespassing activity. In particular, we adopt a CNN-based deep learning architecture (Faster-RCNN) as the core component of our solution. However, these deep learning-based methods, while effective, are known to be computationally expensive and time consuming, especially when applied to a large amount of surveillance data. Given the sparsity of railroad trespassing activity, we design a dual-stage deep learning architecture composed of an inexpensive prefiltering stage for activity detection followed by a high fidelity trespass detection stage for robust classification. The former is responsible for filtering out frames that show little to no activity, this way reducing the amount of data to be processed by the later more compute-intensive stage which adopts state-of-the-art Faster-RCNN to ensure effective classification of trespassing activity. The resulting dual-stage architecture ARTS represents a flexible solution capable of trading-off performance and computational time. We demonstrate the efficacy of our approach on a public domain surveillance dataset.

"Speech enhancement in an automobile is a challenging problem because interference can come from engine noise, fans, music, wind, road noise, reverberation, echo, and passengers engaging in other conversations. Hands-free microphones make the situation worse because the strength of the desired speech signal reduces with increased distance between the microphone and talker. Automobile safety is improved when the driver can use a hands-free interface to phones and other devices instead of taking his eyes off the road. The demand for high quality hands-free communication in the automobile requires the introduction of more powerful algorithms. This thesis shows that a unique combination of five algorithms can achieve superior speech enhancement for a hands-free system when compared to beamforming or spectral subtraction alone. Several different designs were analyzed and tested before converging on the configuration that achieved the best results. Beamforming, voice activity detection, spectral subtraction, perceptual nonlinear weighting, and talker isolation via pitch tracking all work together in a complementary iterative manner to create a speech enhancement system capable of significantly enhancing real world speech signals. The following conclusions are supported by the simulation results using data recorded in a car and are in strong agreement with theory. Adaptive beamforming, like the Generalized Side-lobe Canceller (GSC), can be effectively used if the filters only adapt during silent data frames because too much of the desired speech is cancelled otherwise. Spectral subtraction removes stationary noise while perceptual weighting prevents the introduction of offensive audible noise artifacts. Talker isolation via pitch tracking can perform better when used after beamforming and spectral subtraction because of the higher accuracy obtained after initial noise removal. Iterating the algorithm once increases the accuracy of the Voice Activity Detection (VAD), which improves the overall performance of the algorithm. Placing the microphone(s) on the ceiling above the head and slightly forward of the desired talker appears to be the best location in an automobile based on the experiments performed in this thesis. Objective speech quality measures show that the algorithm removes a majority of the stationary noise in a hands-free environment of an automobile with relatively minimal speech distortion."

Made available in DSpace on 2015-03-05T13:56:58Z (GMT). No. of bitstreams: 0 Previous issue date: 20 / Hewlett-Packard Brasil Ltda / Este trabalho apresenta um modelo para extrair informações do mundo real, capturadas com a utilização de técnicas de visão computacional, no que tange acompanhamento de indivíduos, com o fim de simular e validar comportamentos de multidões de humanos virtuais. Uma grande dificuldade ao se tentar reproduzir de forma realista (por meio de simulação) o comportamento de uma multidão em um determinado espaço é informar para o modelo de simulação todos os atributos necessários para descrever o movimento das pessoas virtuais. Além das características individuais e coletivas das pessoas poderem produzir uma grande variedade de comportamentos, tornando sua modelagem complexa, o espaço também contém restrições que podem interferir no comportamento das pessoas. Neste trabalho é proposto um modelo onde pessoas do mundo real têm suas trajetórias capturadas de forma automática. Numa etapa de pós-processamento, as trajetórias capturadas são utilizadas para gerar campos de vetores velocidade que serão utilizados para aux / This study presents a model to extract information from the real world using computer vision techniques. In particular, we use tracking algorithms to extract the trajectories of filmed people, aiming to simulate and validate the behavior of virtual human crowds.A great challenge when trying to reproduce in a realistic manner (by means of simulation) the behavior of a crowd in a determined space is to inform to the simulation model all necessary attributes to describe the movement of virtual people. Individual and general features of people can produce a great variety of behaviors, making its modeling complex. Furthermore, the space also contains restrictions that can interfere on people behavior. In this study it is proposed a model in which people from the real world have their trajectories captured in an automatic manner. In a post-processing step, captured trajectories are used to generate velocity fields that will be used to help in the calculation of virtual human movement, providing more realistic s

Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Os implantes osteointegráveis assumiram condição prioritária na reabilitação da perda dentária unitária ou múltipla em função das elevadas taxas de sucesso e previsibilidade no tratamento e vêm sendo cada vez mais utilizados por especialistas e clínicos. Atualmente existe a preocupação com a manutenção dos tecidos moles periimplantares, principalmente em áreas estéticas. De modo geral, um ano após a instalação dos implantes osteointegráveis ocorre uma perda óssea proximal de 1,5 mm e em média 0,1 mm durante os anos subsequentes. Nos últimos anos, achados clínicos evidenciaram menor perda óssea inicial associada a intermediários de diâmetro reduzido em relação à plataforma dos implantes. Com o objetivo de comparar, por meio de imagens radiográficas o comportamento ósseo proximal ao redor de implantes osteointegráveis com plataformas convencionais e plataformas de diâmetro intermediário reduzido, foi estabelecido o seguinte desenho de estudo clínico prospectivo: em 08 pacientes totalmente edentados, foram instalados 40 implantes, 5 implantes mandibulares por paciente. Cada paciente recebeu 3 implantes com plataforma convencional e 2 com plataforma associada aos intermediários de diâmetro reduzido (cone morse). Foram confeccionadas próteses em resina acrílica e fixadas precocemente aos implantes por intermédio de parafusos, seguindo o modelo protocolo Bränemark. Foram feitas radiografias periapicais padronizadas em intervalos de 21 dias, 3, 6 e 12 meses, após a instalação dos implantes. As imagens radiográficas foram digitalizadas e realizada a subtração radiográfica digital pelo programa emago, sendo comparadas com a radiografia inicial. Os resultados obtidos neste estudo mostraram uma regularidade no remodelamento ósseo ao longo do tempo para todos os implantes, não tendo sido encontradas diferenças significativas entre os diferentes implantes analisados. / In regard of the high successful rates and the excellent outcome, dental implants become the first option in rehabilitation for dental loss. In this way the maintenance of soft peri-implant tissues came up as a new issue to consider especially when esthetic areas are being restored. Generally a bone loss of approximately 1,5 mm occurs after one year of dental implant installation and every following year a new bone loss of about 0,1mm also happen. It has been demonstrated an association between a lower initial bone loss and switch platform. Aiming to compare the crestal bone status around dental implants between conventional platform implants and switch platform implants, dental radiographic images were analyzed and compared in a short term prospective clinical study. Eight complete edentulous patients were submitted to minor oral surgery to dental implants installation. Five mandibular dental implants were installed in each patient in a total of 40 dental implants. Three out of the five dental implants were conventional platform implants and two were platform switching implants (morse taper). Previous prepared mandibular total dentures were early screw attached according to Bränemark protocol. The radiographic follow up was performed 21 days and 3, 6 and 12 months after after the surgery. The periapical X-Ray were digitalized and a digital image subtraction was performed with emago software, All X-Ray were compared to the first X-Ray. The results shown a regular bone remodeling troughtout the follow up period and no significative differences were found between the analysed implants.

Detecting unusual movement (falls) for elderly people in enclosed environments is receiving increasing attention and is likely to have massive potential social and economic impact. In this thesis, new intelligent computer vision processing based techniques are proposed to detect falls in indoor environments for senior citizens living independently, such as in intelligent homes. Different types of features extracted from video-camera recordings are exploited together with both background subtraction analysis and machine learning techniques. Initially, an improved background subtraction method is used to extract the region of a person in the recording of a room environment. A selective updating technique is introduced for adapting the change of the background model to ensure that the human body region will not be absorbed into the background model when it is static for prolonged periods of time. Since two-dimensional features can generate false alarms and are not invariant to different directions, more robust three-dimensional features are next extracted from a three-dimensional person representation formed from video-camera measurements of multiple calibrated video-cameras. The extracted three-dimensional features are applied to construct a single Gaussian model using the maximum likelihood technique. This can be used to distinguish falls from non-fall activity by comparing the model output with a single. In the final works, new fall detection schemes which use only one uncalibrated video-camera are tested in a real elderly person s home environment. These approaches are based on two-dimensional features which describe different human body posture. The extracted features are applied to construct a supervised method for posture classification for abnormal posture detection. Certain rules which are set according to the characteristics of fall activities are lastly used to build a robust fall detection model.

Este trabalho tem a finalidade de apresentar e comparar técnicas de redução de ruído utilizando como critérios de avaliação a mínima distorção espectral e a redução de ruído, na reconstrução dos sinais de voz degradados por ruído. Para tanto, utilizou-se os filtros de Kalman de tempo discreto e de freqüência discreta em conjunto com a técnica de subtração espectral de potência. Os sinais utilizados foram contaminados por ruídos branco e colorido, e a avaliação do desempenho dos algoritmos foi realizada tendo-se como parâmetros a relação sinal/ruído segmentada (SNRseg) e a distância de Itakura-Saito (d(a,b)). Após o processamento, verificou-se que a técnica, proposta neste trabalho, de filtragem de Kalman no tempo em conjunto com a subtração espectral de potência, apresentou resultados um pouco melhores em relação à filtragem de Kalman na freqüência em conjunto com a subtração espectral de potência. / This work has as main objective to present and to compare techniques of noise reduction using as evaluation criterion the low spectral distortion and the noise reduction in the reconstruction of corrupted speech signals. For so much, it was used the Kalman\'s filters in the time and frequency domain together with the technique of power spectral subtraction. The used signals were corrupted by white and colored noises and the evaluation of effectiveness of the algorithms was accomplished using the segmental signal-to-noise ratio (SNRseg) and the Itakura-Saito distance (d(a,b)). After the processing, it was noticed that the Kalman filtering in the time together with power spectral subtraction presented better results than the Kalman filtering in the frequency together with power spectral subtraction.

Herbig Ae/Be (HAeBe) stars are intermediate mass (2-10 solar mass) pre-main sequence stars with circumstellar disks. Observing planets within these young disks would greatly aid in understanding planet formation processes and timescales particularly around massive stars. So far, only one planet, HD 100546 b, has been confirmed to orbit a HAeBe star. With over 250 HAeBe stars known, and several observed to have disks with structures thought to be related to planet formation, it seems likely that there are as yet undiscovered planetary companions within the circumstellar disks of some of these young stars. Direct detection of a low-luminosity companion near a star requires high contrast imaging, often with the use of a coronagraph, and the subtraction of the central star's point spread function (PSF). Several processing algorithms have been developed in recent years to improve PSF subtraction and enhance the signal-to-noise of sources close to the star. However, many HAeBe stars were observed via direct imaging before these algorithms came out. We used the PSF subtraction program PynPoint to reprocess archival images of HAeBe stars from the Advanced Camera for Surveys on the Hubble Space Telescope to increase the likelihood of detecting a planet in their disks. We believe we have recovered the known planet around HD 100546 and possibly its candidate second companion. We also detect new candidate sources in the vicinities of HD 141569 and HD 163296. Further observations are needed to confirm the reality of these detections and also establish their association with the host stars.