Apesar de Escherichia coli O157:H7 ainda ser considerado o principal sorotipo envolvido com surtos de enfermidades veiculadas por alimentos entre as E. coli produtoras de toxina de Shiga (STEC), outros sorogrupos estão ganhando importância, como O26, O45, O103, O111, O121 e O145, que estão sendo denominados de \"Top Six STEC non O157\". As STEC são responsáveis por sintomas que variam de uma simples diarreia até diarreia sanguinolenta, que pode evoluir ainda para síndrome hemolítica urêmica e púrpura trombótica trombocitopênica, podendo ocasionar danos crônicos como falência renal e levar a óbito. Para tanto, apresentam diversos fatores de virulência, entre eles, as toxinas de Shiga (Stx) ou verotoxinas (Vtx). Os veículos destes micro-organismos são diversos alimentos, sendo o principal deles, as carnes moídas. Apesar da importância da carne moída como veículo transmissor de STEC, pouco se conhece sobre a sua presença nesse alimento comercializado na cidade de São Paulo, SP. Sendo assim, o objetivo deste trabalho foi pesquisar a presença de STEC em carne moída comercializada no varejo da cidade de São Paulo e caracterizar tais isolados quanto à presença dos seguintes fatores de virulência: stx1, stx2, eae e ehx. Foram coletadas 248 amostras em diferentes bairros da cidade de São Paulo. Para a detecção de E. coli sorogrupo O157 foi utilizada a metodologia ISO 16654 e para a detecção dos sorogrupos O103, O111, O145 e O26 foi empregada a metodologia descrita pelo Surveillance Group for Diseases and Infections of Animals (NRM 006). Uma amostra de carne moída (0,4%) apresentou o micro-organismo pesquisado. A identificação genotípica e bioquímica caracterizou esse isolado como STEC O157:H7, portador de todos os fatores de virulência pesquisados: stx1, stx2, eae e ehx. Foi constatada, também, a expressão das proteínas stx em células Vero. Esse é o primeiro relato da presença de E. coli O157:H7 produtora de toxina de Shiga em carne moída no Brasil. / Although Escherichia coli O157:H7 is still considered the most important serotype involved in foodborne disease outbreaks among Shiga toxin-producing E. coli (STEC), other serogroups are receiving more attention such as O26, O45, O103, O111, O121 and O145, that are being called the \"Top Six STEC non O157\". STEC are responsible for symptoms ranging from simple diarrhea to bloody diarrhea, which can further evolve to hemolytic uremic syndrome and thrombotic thrombocytopenic purpura, which may cause damage such as chronic renal failure and lead to death. To do so, they have several virulence factors, including the Shiga toxins (Stx) or verotoxins (Vtx). The vehicles of these microorganisms are many foods, most notably, the ground beef. Despite the importance of ground beef as a vehicle for transmitting STEC, little is known about their presence in this kind of food sold in São Paulo, SP. Therefore, the objective of this study was to investigate the presence of STEC in ground beef sold at retail level in Sao Paulo city and characterize the isolates for the presence of the following virulence factors: stx1, stx2, eae and ehx. 248 samples were collected in different districts of Sao Paulo city. For the detection of E. coli O157 serogroup the methodology ISO 16654 was used and for the detection of serogroups O103, O111, O145 and O26 the methodology described by the Surveillance Group for Diseases and Infections of Animals (NRM 006) was used. One sample of ground beef (0.4%) showed the presence of the microorganism studied. The biochemical and genotypical identification characterized this isolate as STEC O157:H7, carrying all of the investigated virulence factors: stx1, stx2, eae and ehx. The expression of stx proteins in Vero cells was also observed. This is the first report on the isolation of E. coli O157:H7 Shiga toxin-producing from ground beef in Brazil.

This research focuses on the study of the behavior of a high speed vehicle and particularly an air-cushion vehicle (ACV) in varying bathymetry. An extensive data acquisition system is developed to gather data during the experiments. Four groups of experiments are conducted in a wave tank using a scale model surface effect ship to generate a database that is post processed to assess phenomena under various conditions. Group No1 experiments involved characterizing the wave motion in the tank in the absence of the vehicle as the waves transformed in response to variation in water depth. Based on these experimental datasets, the wave breaking type and position are predicted using a machine learning approach and, more specifically, a neural network of the multilayer perceptron type. Group No2 experiments are in support of a parametric study to evaluate the vehicle's performance under calm water conditions when the control inputs are varied. A system identific ation approach based on the experimental data is proposed to create a model that predicts the vehicles translational motion. In group No3 the experiments involve the vehicle travelling with a non-zero forward speed and encountering transforming head and following seas. Transient and non-linear phenomena and relations among parameters are observed Group No 4 experiments involve the vehicle maintaining a position in the "surf-zone" under manual control, encountering breaking waves that break on its bow skirt. Non-linear phenomena are discussed based on the experimental results. / Includes bibliography. / Dissertation (Ph.D.)--Florida Atlantic University, 2015. / FAU Electronic Theses and Dissertations Collection

Shadows are ubiquitous in image and video, and their removal is of interest in both Computer Vision and Graphics. In this thesis, four methods for interactive shadow removal from single images are presented. Their improvements are made in user interaction, quality and robustness of shadow removal. We also show our state-of-the-art ground truth data set with variable scene categories for shadow removal and applications for shadow editing and its extension to video data processing.

This thesis includes experimental and theoretical work performed to investigate the behaviour of ground anchors in sand. The anchor footing used was a circular plate connected to a tie rod. The experimental work was carried out by installing the anchor in a l830mm x 1830mm x l220mm deep tank containing dry sand. The sand sample was prepared by using a vibrator fixed to the bottom of the tank. The anchor was pulled out at a constant rate of strain and the load-displacement curve was recorded on a plotter. The vibration of the tank was defined by deter.mining the acceleratton and amplitude of the motion in the horizontal and vertical directions. A density tube and a hydraulic gauge were designed to investigate the distribution of stresses in sand. The variation of the vibration time, the constant rate of strain, the shaf V plate diameter, the plate thickness/plate diameter, and the boundary distance with the load-displacement curve were also investigated. The load-displacement curve of different diameter plates embedded at various depths for different times of vibration were recorded. To investigate the behaviour of ground anchors theoretically, the finite element technique was used and a computer progra~ developed. A linear stress-strain relationship was used to predj.ct and investigate the behaviour of the anchor. A non-linear stress-strain relationship and a failure criterion were also used to predict the load-displacement curve of the vertical anchor. The effect of the parameters which were investigated experimentally were also examined. The distribution of the load on the anchor plate and the extent of the failure zone were plotted. The predicted and experimental results in this thesis were compared with laboratory and field results obtained by previous researchers.

This thesis describes the flow of ground water with a free water table, in an isotropic and homogeneous soil overlying a horizontal impermeable layer, from a surface-applied rainfall or irrigation supply to a system of horizontal tube drains. The idealized representation of this situation is in terms of a potential flow towards line sinks. The tube drains (sinks) may be at atmospheric pressure (free flow) or under back-pressure (submerged flow). After describing the flow to systems of drains at uniform depth and equal spacings, the thesis shows the effect of horizontal, vertical and combined misalignments of a single line sink on the free surface, the flow pattern and the rates of flow to each sink. The study was carried out by viscous-flow and electrical analogues, by a numerical method (Relaxation), and by the exact solution of equations based on physical approximations. In theory the extent of the effect of any misalignment is infinite. Experimentally it was found that the vertical misalignment had a significant effect on the free surface, discharge and flow net over the whole range of the experiment, while the horizontal one had a noticeable effect only extending over one spacing on either side of the misaligned drain. An approximate mathematical solution for the horizontal displacement has been obtained. Experiments on the viscous-flow model revealed the importance of the effect on the free surface etc. of the back pressure. The distribution of the effect along the free surface and the correlation between the free surface height and the back pressure are also presented. A new approach was used to elucidate the effect of negative pressure (capillary rise) on the free surface and obtain the surface of atmospheric pressure. An equation, independent of the geometrical scale ratio was derived to relate the various parameters for the unsteady flow to the scaling laws. The introduction of a reference potential at a fixed point in the field provides a method for the correction of the change with time in the position of equipotentials and represents a new technique. The variations of free surface heights with discharge, as observed on the viscous-flow model, were compared with the results of s some recent theories and showed discrepancies between the experiment and theories.

Estimating the dense image motion or optical flow on a real-world nonrigid surface is a fundamental research issue in computer vision, and is applicable to a wide range of fields, including medical imaging, computer animation and robotics. However, nonrigid surface tracking is a difficult challenge because complex nonrigid deformation, accompanied by image blur and natural noise, may lead to severe intensity changes to pixels through an image sequence. This violates the basic intensity constancy assumption of most visual tracking methods. In this thesis, we show that local geometric constraints and long term feature matching techniques can improve local motion preservation, and reduce error accumulation in optical flow estimation. We also demonstrate that combining RGB data with additional information from other sensing channels, can improve tracking performance in blurry scenes as well as allow us to create nonrigid ground truth from real world scenes. First, we introduce a local motion constraint based on a laplacian mesh representation of nonrigid surfaces. This additional constraint term encourages local smoothness whilst simultaneously preserving nonrigid deformation. The results show that our method outperforms most global constraint based models on several popular benchmarks. Second, we observe that the inter-frame blur in general video sequences is near linear, and can be roughly represented by 3D camera motion. To recover dense correspondences from a blurred scene, we therefore design a mechanical device to track camera motion and formulate this as a directional constraint into the optical flow framework. This improves optical flow in blurred scenes. Third, inspired by recent developments in long term feature matching, we introduce an optimisation framework for dense long term tracking -- applicable to any existing optical flow method -- using anchor patches. Finally, we observe that traditional nonrigid surface analysis suffers from a lack of suitable ground truth datasets given real-world noise and long image sequences. To address this, we construct a new ground truth by simultaneously capturing both normal RGB and near-infrared images. The latter spectrum contains dense markers, visible only in the infrared, and represents ground truth positions. Our benchmark contains many real-world scenes and properties absent in existing ground truth datasets.

Digital-to-analog converters with a range over 50 volts are required for driving micro-electro mechanical system deformable mirrors used in adaptive optics. An existing tested and deployed DM driver has 1024 channels and resolution of 15mV per Least Significant Bit. DMs used in the search for exoplanets require 3mV per LSB resolution. A technique is presented to employ a secondary high resolution and low voltage DAC which has for it's ground the output of the high voltage DAC. The entire system then has the range of high voltage DAC yet the resolution of the low voltage DAC. A method for providing signal and power to the floating system is given. Rudimentary micro controller firmware and also PC software is presented to achieve complete functionality. The technique uses all off-the-shelf components. Resolution of 1.6mV per LSB, 60V range and 36mW of power per channel is achieved.

O objetivo do presente estudo foi de analisar as respostas de ativação muscular e força de reação do solo de um exercício de hidroginástica com diferentes equipamentos, executado por mulheres jovens. Sendo assim, foram realizados três testes progressivos máximos em ambiente aquático, com no mínimo 48 horas de intervalo, com o exercício de chute, sem equipamento (SE), com equipamento resistivo (RE) e flutuante (FL), a fim de determinar a cadência correspondente ao segundo limiar ventilatório (LV2). O terceiro e último dia de testes consistiu primeiramente na contração voluntária isométrica máxima (CVM) em ambiente terrestre, dos músculos a serem avaliados: reto femoral (RF), bíceps femoral (BF), tibial anterior (TA) e gastrocnêmio lateral (GA). Após finalizada a CVM de cada músculo, foi feito um isolamento dos eletrodos, e então o sujeito entrou na piscina para realizar os testes de eletromiografia (EMG) e força de reação do solo (FRS) nas intensidades do LV2 e máximo esforço (MAX). Dentro da piscina, o sujeito foi posicionado na profundidade do processo xifóide e então, executou as três situações do exercício de chute (SE, RE e FL), de forma randomizada, nas intensidades LV2 e máximo esforço (MAX). Foi utilizada o teste estatístico de Equações estimativas generalizadas e o teste post-hoc de Bonferroni. Após o tratamento dos dados e análise estatística, foram encontrados maiores valores de ativação muscular da intensidade LV2 para MAX, para todas as situações nos músculos RF, BF e TA, exceto para GL que não obteve diferenças entre intensidades para a situação RE. Comparando as situações, não houve diferenças significativas entre as mesmas para RF, BF e TA, exceto para o músculo GLque obteve menores valores de ativação para a situação RE comparada à SE. Para os resultados de FRS, foram encontrados maiores valores para a intensidade MAX para as situações SE e RE, enquanto para FL, não foram encontradas diferenças de FRS entre as intensidades. Comparando as situações, FL obteve menores valores comparado à SE e RE, nas duas intensidades. Para os resultados de impulso (IMP), foram encontradas diferenças significavamente menores para a intensidade MAX para todas as situações, com menores valores de IMP na situação FL. A partir dos resultados encontrados no 6 presente estudo, de uma maneira geral, a utilização de equipamentos tanto RE quanto FL, parece não influenciar a ativação muscular durante a execução do exercício CH, além disso, a intensidade MAX elicita maiores valores de ativação. Além disso, apesar de terem sido encontradas diferenças de FRS e IMP entre as intensidades, o equipamento FL obteve menores valores de FRS e IMP, sem diferenças entre LV2 e MAX na FRS, demonstrando que apesar de obter uma maior ativação muscular em MAX, não houve um aumento significativo de FRS nesta intensidade. Sendo assim, a utilização de equipamentos parece influenciar principalmente a variável de FRS, reduzindo estes valores e tornando o exercício de CH mais seguro quando é necessária uma menor sobrecarga articular, enquanto a ativação muscular não se difere das outras situações. / The aim of the presente study was to analyze the muscle activation and ground reaction forces responses of one hydrogymnastic exercise performed by women with different devices. Three sessions of water progressive testes were conducted with 48 hours of interval with the frontal kick exercise (FK) without devices (WD), with resistance devices (RD) and floating devices (FD), to determine the cadence corresponding to the second ventilatory threshold (VT2).The third and last day of tests consisted iniciated with the maximum voluntary contraction (MVC) of the muscles to be analyzed: rectus femoris (RF), biceps femoris (BF), tibialis anterior (TA) and gastrocnemius lateralis (GL). After that, the electrodes were isolated and than the subject entered the pool (immersion on the xifoide process) to perform the electromiography (EMG) and ground reaction forces (GRF) tests in VT2 and maximum (MAX) intensity. Generalized estimating equation and Bonferroni’s test were used for the statistical analyses. The results showed higher muscle activity for the MAX comparing to VT2 for RF, BF and TA, except for GL muscle, which didn’t achieve difference between the intensities for RD. Comparing the three situations, there was no significant difference between. In VT2 and MAX there was no difference between all situations, except for GL in MAX, which obtained lower values for RD compared with FD. The ground reaction forces results showed higher values for the MAX intensity for the WD and RD situations, while for FD there was no difference between VT2 and MAX. Comparing the situations, FD obtained lower values compared with WD and RD in both intensities. For impulse (IMP), significant lower values were founde for the MAX intensity for all situations, with lower values for FD. According to the results, it might be concluded that the use of devices seems to not influence the muscle activity during the FK exercise, besides that, the MAX intensity elicits higher results. Despite the differences for GRF and IMP, the FL situation leads to a higher muscle activation in MAX while there is no GRF increase from VT2. Therefore, the use of devices appears to influence mostly the GRF variable, showing lowest values for this situation comparing to WD and RD making FK safer when a lower joint overload is needed, while the muscle activation didn’t differ from WD and RD.

Thesis. 1977. Sc.D.--Massachusetts Institute of Technology. Dept. of Mechanical Engineering. / MICROFICHE COPY AVAILABLE IN ARCHIVES AND ENGINEERING. / Includes bibliographical references. / Sc.D.

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