821 resultados para Residential trajectory


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BACKGROUND: Decreasing exposure to airborne particulates was previously associated with reduced age-related decline in lung function. However, whether the benefit from improved air quality depends on genetic background is not known. Recent evidence points to the involvement of the genes p53 and p21 and of the cell cycle control gene cyclin D1 (CCND1) in the response of bronchial cells to air pollution. OBJECTIVE: We determined in 4,326 participants of the Swiss Cohort Study on Air Pollution and Lung and Heart Diseases in Adults (SAPALDIA) whether four single-nucleotide polymorphisms in three genes [CCND1 (rs9344 [P242P], rs667515), p53 (rs1042522 [R72P]), and p21 (rs1801270 [S31R])] modified the previously observed attenuation of the decline in the forced expiratory flow between 25% and 75% of the forced vital capacity (FEF(25-75)) associated with improved air quality. METHODS: Subjects of the prospective population-based SAPALDIA cohort were assessed in 1991 and 2002 by spirometry, questionnaires, and biological sample collection for genotyping. We assigned spatially resolved concentrations of particulate matter with aerodynamic diameter < or = 10 microm (PM(10)) to each participant's residential history 12 months before the baseline and follow-up assessments. RESULTS: The effect of diminishing PM(10) exposure on FEF(25-75) decline appeared to be modified by p53 R72P, CCND1 P242P, and CCND1 rs667515. For example, a 10-microg/m(3) decline in average PM(10) exposure over an 11-year period attenuated the average annual decline in FEF(25-75) by 21.33 mL/year (95% confidence interval, 10.57-32.08) among participants homozygous for the CCND1 (P242P) GG genotype, by 13.72 mL/year (5.38-22.06) among GA genotypes, and by 6.00 mL/year (-4.54 to 16.54) among AA genotypes. CONCLUSIONS: Our results suggest that cell cycle control genes may modify the degree to which improved air quality may benefit respiratory function in adults.

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When underwater vehicles navigate close to the ocean floor, computer vision techniques can be applied to obtain motion estimates. A complete system to create visual mosaics of the seabed is described in this paper. Unfortunately, the accuracy of the constructed mosaic is difficult to evaluate. The use of a laboratory setup to obtain an accurate error measurement is proposed. The system consists on a robot arm carrying a downward looking camera. A pattern formed by a white background and a matrix of black dots uniformly distributed along the surveyed scene is used to find the exact image registration parameters. When the robot executes a trajectory (simulating the motion of a submersible), an image sequence is acquired by the camera. The estimated motion computed from the encoders of the robot is refined by detecting, to subpixel accuracy, the black dots of the image sequence, and computing the 2D projective transform which relates two consecutive images. The pattern is then substituted by a poster of the sea floor and the trajectory is executed again, acquiring the image sequence used to test the accuracy of the mosaicking system

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This paper deals with the problem of navigation for an unmanned underwater vehicle (UUV) through image mosaicking. It represents a first step towards a real-time vision-based navigation system for a small-class low-cost UUV. We propose a navigation system composed by: (i) an image mosaicking module which provides velocity estimates; and (ii) an extended Kalman filter based on the hydrodynamic equation of motion, previously identified for this particular UUV. The obtained system is able to estimate the position and velocity of the robot. Moreover, it is able to deal with visual occlusions that usually appear when the sea bottom does not have enough visual features to solve the correspondence problem in a certain area of the trajectory

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INTRODUCTION Functional imaging studies of addiction following protracted abstinence have not been systematically conducted to look at the associations between severity of use of different drugs and brain dysfunction. Findings from such studies may be relevant to implement specific interventions for treatment. The aim of this study was to examine the association between resting-state regional brain metabolism (measured with 18F-fluorodeoxyglucose Positron Emission Tomography (FDG-PET) and the severity of use of cocaine, heroin, alcohol, MDMA and cannabis in a sample of polysubstance users with prolonged abstinence from all drugs used. METHODS Our sample consisted of 49 polysubstance users enrolled in residential treatment. We conducted correlation analyses between estimates of use of cocaine, heroin, alcohol, MDMA and cannabis and brain metabolism (BM) (using Statistical Parametric Mapping voxel-based (VB) whole-brain analyses). In all correlation analyses conducted for each of the drugs we controlled for the co-abuse of the other drugs used. RESULTS The analysis showed significant negative correlations between severity of heroin, alcohol, MDMA and cannabis use and BM in the dorsolateral prefrontal cortex (DLPFC) and temporal cortex. Alcohol use was further associated with lower metabolism in frontal premotor cortex and putamen, and stimulants use with parietal cortex. CONCLUSIONS Duration of use of different drugs negatively correlated with overlapping regions in the DLPFC, whereas severity of cocaine, heroin and alcohol use selectively impact parietal, temporal, and frontal-premotor/basal ganglia regions respectively. The knowledge of these associations could be useful in the clinical practice since different brain alterations have been associated with different patterns of execution that may affect the rehabilitation of these patients.

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Path planning and control strategies applied to autonomous mobile robots should fulfil safety rules as well as achieve final goals. Trajectory planning applications should be fast and flexible to allow real time implementations as well as environment interactions. The methodology presented uses the on robot information as the meaningful data necessary to plan a narrow passage by using a corridor based on attraction potential fields that approaches the mobile robot to the final desired configuration. It employs local and dense occupancy grid perception to avoid collisions. The key goals of this research project are computational simplicity as well as the possibility of integrating this method with other methods reported by the research community. Another important aspect of this work consist in testing the proposed method by using a mobile robot with a perception system composed of a monocular camera and odometers placed on the two wheels of the differential driven motion system. Hence, visual data are used as a local horizon of perception in which trajectories without collisions are computed by satisfying final goal approaches and safety criteria

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This paper presents the use of a mobile robot platform as an innovative educational tool in order to promote and integrate different curriculum knowledge. Hence, it is presented the acquired experience within a summer course named ldquoapplied mobile roboticsrdquo. The main aim of the course is to integrate different subjects as electronics, programming, architecture, perception systems, communications, control and trajectory planning by using the educational open mobile robot platform PRIM. The summer course is addressed to a wide range of student profiles. However, it is of special interests to the students of electrical and computer engineering around their final academic year. The summer course consists of the theoretical and laboratory sessions, related to the following topics: design & programming of electronic devices, modelling and control systems, trajectory planning and control, and computer vision systems. Therefore, the clues for achieving a renewed path of progress in robotics are the integration of several knowledgeable fields, such as computing, communications, and control sciences, in order to perform a higher level reasoning and use decision tools with strong theoretical base

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This article presents recent WMR (wheeled mobile robot) navigation experiences using local perception knowledge provided by monocular and odometer systems. A local narrow perception horizon is used to plan safety trajectories towards the objective. Therefore, monocular data are proposed as a way to obtain real time local information by building two dimensional occupancy grids through a time integration of the frames. The path planning is accomplished by using attraction potential fields, while the trajectory tracking is performed by using model predictive control techniques. The results are faced to indoor situations by using the lab available platform consisting in a differential driven mobile robot

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In this paper we face the problem of positioning a camera attached to the end-effector of a robotic manipulator so that it gets parallel to a planar object. Such problem has been treated for a long time in visual servoing. Our approach is based on linking to the camera several laser pointers so that its configuration is aimed to produce a suitable set of visual features. The aim of using structured light is not only for easing the image processing and to allow low-textured objects to be treated, but also for producing a control scheme with nice properties like decoupling, stability, well conditioning and good camera trajectory

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School-aged children (6-15 years) from the endemic area of Pernambuco were evaluated both as a target group for and an indicator of schistosomiasis control in the community. Parasitological data were drawn from baseline stool surveys of whole populations that were obtained to diagnose Schistosoma mansoni infection. Nineteen representative localities were selected for assessing the prevalence of schistosomiasis among individuals in the following age groups: 0-5, 6-15, 16-25, 26-40 and 41-80 years. For each locality, the prevalence in each age group was compared to that of the overall population using contingency table analysis. To select a reference group, the operational difficulties of conducting residential surveys were considered. School-aged children may be considered to be the group of choice as the reference group for the overall population for the following reasons: (i) the prevalence of schistosomiasis in this age group had the highest correlation with the prevalence in the overall population (r = 0.967), (ii) this age group is particularly vulnerable to infection and plays an important role in parasite transmission and (iii) school-aged children are the main target of the World Health Organization in terms of helminth control. The Schistosomiasis Control Program should consider school-aged children both as a reference group for assessing the need for intervention at the community level and as a target group for integrated health care actions of the Unified Health System that are focused on high-risk groups.

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BACKGROUND Evidence associating exposure to water disinfection by-products with reduced birth weight and altered duration of gestation remains inconclusive. OBJECTIVE We assessed exposure to trihalomethanes (THMs) during pregnancy through different water uses and evaluated the association with birth weight, small for gestational age (SGA), low birth weight (LBW), and preterm delivery. METHODS Mother-child cohorts set up in five Spanish areas during the years 2000-2008 contributed data on water ingestion, showering, bathing, and swimming in pools. We ascertained residential THM levels during pregnancy periods through ad hoc sampling campaigns (828 measurements) and regulatory data (264 measurements), which were modeled and combined with personal water use and uptake factors to estimate personal uptake. We defined outcomes following standard definitions and included 2,158 newborns in the analysis. RESULTS Median residential THM ranged from 5.9 μg/L (Valencia) to 114.7 μg/L (Sabadell), and speciation differed across areas. We estimated that 89% of residential chloroform and 96% of brominated THM uptakes were from showering/bathing. The estimated change of birth weight for a 10% increase in residential uptake was -0.45 g (95% confidence interval: -1.36, 0.45 g) for chloroform and 0.16 g (-1.38, 1.70 g) for brominated THMs. Overall, THMs were not associated with SGA, LBW, or preterm delivery. CONCLUSIONS Despite the high THM levels in some areas and the extensive exposure assessment, results suggest that residential THM exposure during pregnancy driven by inhalation and dermal contact routes is not associated with birth weight, SGA, LBW, or preterm delivery in Spain.

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Rotavirus is an important cause of childhood diarrhoea. A monovalent rotavirus vaccine (Rotarix®) was introduced into the Immunization Program of Brazil in 2006. In this study, we describe the incidence and burden of disease of rotavirus diarrhoea in two cohorts of children (vaccinated and unvaccinated). We followed two groups of 250 children under one year old, who were enrolled in December 2006 from a low-income residential area in Northeast Brazil. The children were monitored every two weeks for two years. Stool samples from children with diarrhoea were examined for the presence of rotavirus. Rotaviruses were genotyped using real time-polymerase chain reaction. The mean numbers of all-cause diarrhoea episodes/child (adjusted for age) in the first year were 0.87 and 0.84, in vaccinated and unvaccinated children, respectively. During the second year, the number of episodes/child decreased to 0.52 and 0.42. Only 16 (4.9%) of 330 stool samples were rotavirus-positive (10 vaccinated and 6 unvaccinated children) and only P[4]G2 rotaviruses were identified. All-cause diarrhoea episodes were more severe in unvaccinated children in the first year of age (p < 0.05), while vaccinated children had more severe episodes 18 months after vaccination. Rotavirus diarrhoea incidence was very low in both groups.

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BACKGROUND: Adherence to combination antiretroviral therapy (cART) is a dynamic process, however, changes in adherence behavior over time are insufficiently understood. METHODS: Data on self-reported missed doses of cART was collected every 6 months in Swiss HIV Cohort Study participants. We identified behavioral groups associated with specific cART adherence patterns using trajectory analyses. Repeated measures logistic regression identified predictors of changes in adherence between consecutive visits. RESULTS: Six thousand seven hundred nine individuals completed 49,071 adherence questionnaires [median 8 (interquartile range: 5-10)] during a median follow-up time of 4.5 years (interquartile range: 2.4-5.1). Individuals were clustered into 4 adherence groups: good (51.8%), worsening (17.4%), improving (17.6%), and poor adherence (13.2%). Independent predictors of worsening adherence were younger age, basic education, loss of a roommate, starting intravenous drug use, increasing alcohol intake, depression, longer time with HIV, onset of lipodystrophy, and changing care provider. Independent predictors of improvements in adherence were regimen simplification, changing class of cART, less time on cART, and starting comedications. CONCLUSIONS: Treatment, behavioral changes, and life events influence patterns of drug intake in HIV patients. Clinical care providers should routinely monitor factors related to worsening adherence and intervene early to reduce the risk of treatment failure and drug resistance.

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Partiendo de la idea ampliamente aceptada de que las TIC (Tecnologías de Información y Comunicación) han tenido una profunda influencia en los modos en que la sociedad contemporánea experimenta y concibe las nociones de espacio y tiempo, y sustentándose en el contexto de la importancia adquirida por dichas nociones en la comprensión de los procesos sociales en general y estéticos en particular, esta investigación ha tenido por objetivo analizar la espacio-temporalidad en el contexto específico de la era digital. Poniendo en relación la fenomenología de los dispositivos tecnológicos con las nuevas estrategias de representación y puesta en imagen del espacio y el tiempo, nuestro propósito ha sido mostrar no sólo cómo a través de las prácticas artísticas digitales puede identificarse y analizarse el imaginario espacio-temporal de la era digital, sino también cómo éstas –basadas en una larga trayectoria estética de intersecciones entre arte y tecnología- han revestido al espacio y al tiempo de nuevas fenomenologías posibles, dando lugar a nuevas formas de percibirlos y cumpliendo, por tanto, un papel activo en la configuración de dicho imaginario y sus sucesivas transformaciones. La perspectiva teórica adoptada para esta investigación parte de las teorías postmodernas del espacio y el tiempo –considerando autores como Harvey o Jameson-, recurriendo a la sociología del Imaginario Social desarrollada por Castoriadis, Castro-Nogueira o J. L. Pintos para comprender cómo el espacio y el tiempo adquieren significaciones particulares. Combinando estas bases teóricas con los estudios visuales y los trabajos de teóricos de los medios como McLuhan, De Kerckhove o Lev Manovich, se establecerían las posibles relaciones entre las tecnologías, las representaciones sociales del espacio y el tiempo – analizadas a partir de metáforas como “compresión espacio-temporal”, “espacio de los flujos” o “tiempo atemporal” y sus relaciones con el Ciberespacio- y la fenomenología espacio-temporal de las prácticas artísticas y sus estrategias de representación visual –tomando como objeto de estudio tipologías artísticas que van desde el Hipercine a la Realidad Virtual y Aumentada, los Medios Locativos o la Telepresencia. La conclusión que hemos podido extraer de este estudio es que si bien distintos tipos de tecnologías afectan operacional y perceptivamente a la construcción social de la espacio-temporalidad, los modos en que estas tecnologías han estetizado la propia realidad y los modos en que condicionan la construcción estética de las nociones de espacio y tiempo, tanto a partir de la propia fenomenología del dispositivo como de la experimentación creativa con el mismo, ejercen una profunda influencia sobre el imaginario social y espacio-temporal propios de la era digital.

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RESUME Les améliorations méthodologiques des dernières décennies ont permis une meilleure compréhension de la motilité gastro-intestinale. Il manque toutefois une méthode qui permette de suivre la progression du chyme le long du tube gastro-intestinal. Pour permettre l'étude de la motilité de tout le tractus digestif humain, une nouvelle technique, peu invasive, a été élaborée au Département de Physiologie, en collaboration avec l'EPFL. Appelée "Magnet Tracking", la technique est basée sur la détection du champ magnétique généré par des matériaux ferromagnétiques avalés. A cet usage, une pilule magnétique, une matrice de capteurs et un logiciel ont été développés. L'objet de ce travail est de démontrer la faisabilité d'un examen de la motilité gastro-intestinale chez l'Homme par cette méthode. L'aimant est un cylindre (ø 6x7 mm, 0.2 cm3) protégé par une gaine de silicone. Le système de mesure est constitué d'une matrice de 4x4 capteurs et d'un ordinateur portable. Les capteurs fonctionnent sur l'effet Hall. Grâce à l'interface informatique, l'évolution de la position de l'aimant est suivie en temps réel à travers tout le tractus digestif. Sa position est exprimée en fonction du temps ou reproduite en 3-D sous forme d'une trajectoire. Différents programmes ont été crées pour analyser la dynamique des mouvements de l'aimant et caractériser la motilité digestive. Dix jeunes volontaires en bonne santé ont participé à l'étude. L'aimant a été avalé après une nuit de jeûne et son séjour intra digestif suivi pendant 2 jours consécutifs. Le temps moyen de mesure était de 34 heures. Chaque sujet a été examiné une fois sauf un qui a répété sept fois l'expérience. Les sujets restaient en décubitus dorsal, tranquilles et pouvaient interrompre la mesure s'ils le désiraient. Ils sont restés à jeûne le premier jour. L'évacuation de l'aimant a été contrôlée chez tous les sujets. Tous les sujets ont bien supporté l'examen. Le marqueur a pu être détecté de l'oesophage au rectum. La trajectoire ainsi constituée représente une conformation de l'anatomie digestive : une bonne superposition de celle-ci à l'anatomie est obtenue à partir des images de radiologie conventionnelle (CT-scan, lavement à la gastrografine). Les mouvements de l'aimant ont été caractérisés selon leur périodicité, leur amplitude ou leur vitesse pour chaque segment du tractus digestif. Ces informations physiologiques sont bien corrélées à celles obtenues par des méthodes établies d'étude de la motilité gastro-intestinale. Ce travail démontre la faisabilité d'un examen de la motilité gastro-intestinal chez l'Homme par la méthode de Magnet Tracking. La technique fournit les données anatomiques et permet d'analyser en temps réel la dynamique des mouvements du tube digestif. Cette méthode peu invasive ouvre d'intéressantes perspectives pour l'étude de motilité dans des conditions physiologiques et pathologiques. Des expériences visant à valider cette approche en tant que méthode clinique sont en voie de réalisation dans plusieurs centres en Suisse et à l'étranger. SUMMARY Methodological improvements realised over the last decades have permitted a better understanding of gastrointestinal motility. Nevertheless, a method allowing a continuous following of lumina' contents is still lacking. In order to study the human digestive tract motility, a new minimally invasive technique was developed at the Department of Physiology in collaboration with Swiss Federal Institute of Technology. The method is based on the detection of magnetic field generated by swallowed ferromagnetic materials. The aim of our work was to demonstrate the feasibility of this new approach to study the human gastrointestinal motility. The magnet used was a cylinder (ø6x7mm, 0.2 cm3) coated with silicon. The magnet tracking system consisted of a 4x4 matrix of sensors based on the Hall effect Signals from the sensors were digitised and sent to a laptop computer for processing and storage. Specific software was conceived to analyse in real time the progression of the magnet through the gastrointestinal tube. Ten young and healthy volunteers were enrolled in the study. After a fasting period of 12 hours, they swallowed the magnet. The pill was then tracked for two consecutive days for 34 hours on average. Each subject was studied once except one who was studied seven times. Every subject laid on his back for the entire experiment but could interrupt it at anytime. Evacuation of the magnet was controlled in all subjects. The examination was well tolerated. The pill could be followed from the esophagus to the rectum. The trajectory of the magnet represented a "mould" of the anatomy of the digestive tube: a good superimposition with radiological anatomy (gastrografin contrast and CT) was obtained. Movements of the magnet were characterized by periodicity, velocity, and amplitude of displacements for every segment of the digestive tract. The physiological information corresponded well to data from current methods of studying gastrointestinal motility. This work demonstrates the feasibility of the new approach in studies of human gastrointestinal motility. The technique allows to correlate in real time the dynamics of digestive movements with the anatomical data. This minimally invasive method is ready for studies of human gastrointestinal motility under physiological as well as pathological conditions. Studies aiming at validation of this new approach as a clinically relevant tool are being realised in several centres in Switzerland and abroad. Abstract: A new minimally invasive technique allowing for anatomical mapping and motility studies along the entire human digestive system is presented. The technique is based on continuous tracking of a small magnet progressing through the digestive tract. The coordinates of the magnet are calculated from signals recorded by 16 magnetic field sensors located over the abdomen. The magnet position, orientation and trajectory are displayed in real time. Ten young healthy volunteers were followed during 34 h. The technique was well tolerated and no complication was encountered, The information obtained was 3-D con-figuration of the digestive tract and dynamics of the magnet displacement (velocity, transit time, length estimation, rhythms). In the same individual, repea-ted examination gave very reproducible results. The anatomical and physiological information obtained corresponded well to data from current methods and imaging. This simple, minimally invasive technique permits examination of the entire digestive tract and is suitable for both research and clinical studies. In combination with other methods, it may represent a useful tool for studies of Cl motility with respect to normal and pathological conditions.

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El present treball de recerca explora i descriu alguns dels aspectes més rellevants del que ha estat la trajectòria de l’Aula de Teatre de la UVic (ATUV) al llarg dels anys. Consta de dues parts diferenciades. En la primera, presento de forma breu alguns dels elements bàsics de caràcter històric que configuren la relació del teatre amb l’educació, fent una especial referència al teatre universitari a l’estat espanyol i a Catalunya. La segona part del treball es desdobla, a la vegada, en dues perspectives. En una, dono compte de l’evolució realitzada per l’Aula de Teatre de la Universitat de Vic, des del punt de vista de la seva organització, característiques i funcionament, i produccions. S’ha fet una memòria descriptiva dels 18 anys de trajectòria de l’ATUV. La segona perspectiva aporta la visió del conjunt de persones (estudiants i exestudiants) que han passat per l’ATUV i que fan, a partir d’un qüestionari tramès prèviament, una valoració dels objectius de dinamització cultural de la Universitat que es proposa l’aula, així com dels aspectes de formació humanística que comprenen el treball de valors, d’habilitats i d’actituds com a procés de creixement personal que han viscut en la seva experiència a l’ATUV..