La position des membres le long du corps est reproductible chez une même espèce mais est très variable entre différentes espèces. Comment les membres acquièrent leur position et quel mécanisme est à l'origine de ces variations est à ce jour non élucidé. De part leur rôle dans la mise en place des axes embryonnaires, les gènes Hox sont depuis longtemps suspectés de jouer un rôle dans ce processus. Cependant les différentes preuves disponibles à ce jour restent indirectes et corrélatives. Chez l'embryon de poulet, je montre que la position des membres est établit précocement au cours du développement, lors de la gastrulation. Je démontre que la formation de la lame latérale (i.e. le tissue d'origine des membres) est un processus graduel et que l'activation séquentielle des gènes Hox spécifie ce tissue en domaines du membre et du flanc. Dans un second temps, une combinaison d'actions activatrice et répressive des gènes Hox sur le programme d'initiation du membre, actions liées à leur organisation colinéaire, est critique pour l'organisation de la lame latérale en domaines du membre et du flanc. Enfin, en étudiant des embryons de différentes espèces d'oiseaux présentant des variations dans la longueur de leur cou et donc dans la position de leur ailes (le poulet, l'autruche et le diamant mandarin), je montre que des changements relatifs dans la séquence d'activation colinéaire des gènes Hox au cours de la gastrulation sous-tendent les variations naturelles de la position de l'aile. L'ensemble de ces résultats montre que les gènes Hox jouent un rôle direct et précoce dans le positionnement des membres et propose un model général de mise en place d'un organisme par ces gènes. / Limb position along the main body axis is highly consistent within one species but very variable among tetrapods. Despite major advances in our understanding of limb patterning in three dimensions, how limbs reproducibly form along the anteroposterior axis remains largely unknown. Hox genes have long been suspected to play a role in this process, however supporting evidences are mostly correlative and a direct role has yet to be demonstrated. Here, using bird embryos, I show that limb position is established very early during development, during the process of gastrulation. I find that the formation of the Lateral Plate Mesoderm (i.e. the embryonic compartment from which limbs will form) is a progressive process and that co-linear activation of Hox genes sequentially patterns it along the antero-posterior axis. Subsequent combinatorial activation and repression activities of Hox genes on limb initiation are particularly critical to pattern the LPM into limb- and non-limb-forming domains. Finally, by analyzing chicken, zebra finch and ostrich embryos which exhibit variation in their forelimb position, I show that relative changes in the timing of co-linear Hox gene activation during gastrulation underlie variation in limb position. Altogether these result shed light on the cellular and molecular mechanism that regulate limb position by showing a direct and early role for Hox genes in this process during gastrulation and provide a mechanism for variation in body plan organization observed in tetrapods.

Esta dissertação refere-se `a simulação de um sistema de controle em um manipulador robótico para compensação dos movimentos do coração em cirurgias cardíacas minimamente invasivas. No intuito de compensar os movimentos do batimento cardíaco utilizam-se técnicas de controle híbrido de posição/força e dados dos movimentos do coração obtidos in vivo, utilizadas como elementos básicos para a constituição deste sistema. Tópicos de modelagem de manipuladores robóticos e, em especial, a modelagem da relação entre as forças e deslocamentos na superfície do coração compõe a base estrutural. Focalizou-se, ainda, o papel do controle de força em relação `a posição da ferramenta do manipulador na superfície do coração. Pretende-se que a principal contribuição deste trabalho seja demonstrar que o controlador híbrido segue as restrições impostas pela dinâmica do sistema coração-pulmão. / This paper refers to the simulation of a control system for a robotic manipulator to compensate the movements of the heart in minimally invasive cardiac surgery. In order to compensate the motion of the beating heart techniques are used to implement a hybrid position/force controller based on data and the movements of the heart obtained in vivo, used as references to the input of the system. Topics modeling robotic manipulators, and in particular, modeling the relationship between forces and displacements on the surface of the heart comprises the structural basis. The role of power control over the position of the manipulator tool on the surface of the heart. It is intended that the main contribution of this study is to show that the hybrid controller follows the restrictions imposed by the dynamics of the heart-lung system.

Esta dissertação refere-se `a simulação de um sistema de controle em um manipulador robótico para compensação dos movimentos do coração em cirurgias cardíacas minimamente invasivas. No intuito de compensar os movimentos do batimento cardíaco utilizam-se técnicas de controle híbrido de posição/força e dados dos movimentos do coração obtidos in vivo, utilizadas como elementos básicos para a constituição deste sistema. Tópicos de modelagem de manipuladores robóticos e, em especial, a modelagem da relação entre as forças e deslocamentos na superfície do coração compõe a base estrutural. Focalizou-se, ainda, o papel do controle de força em relação `a posição da ferramenta do manipulador na superfície do coração. Pretende-se que a principal contribuição deste trabalho seja demonstrar que o controlador híbrido segue as restrições impostas pela dinâmica do sistema coração-pulmão. / This paper refers to the simulation of a control system for a robotic manipulator to compensate the movements of the heart in minimally invasive cardiac surgery. In order to compensate the motion of the beating heart techniques are used to implement a hybrid position/force controller based on data and the movements of the heart obtained in vivo, used as references to the input of the system. Topics modeling robotic manipulators, and in particular, modeling the relationship between forces and displacements on the surface of the heart comprises the structural basis. The role of power control over the position of the manipulator tool on the surface of the heart. It is intended that the main contribution of this study is to show that the hybrid controller follows the restrictions imposed by the dynamics of the heart-lung system.

Esta dissertação refere-se `a simulação de um sistema de controle em um manipulador robótico para compensação dos movimentos do coração em cirurgias cardíacas minimamente invasivas. No intuito de compensar os movimentos do batimento cardíaco utilizam-se técnicas de controle híbrido de posição/força e dados dos movimentos do coração obtidos in vivo, utilizadas como elementos básicos para a constituição deste sistema. Tópicos de modelagem de manipuladores robóticos e, em especial, a modelagem da relação entre as forças e deslocamentos na superfície do coração compõe a base estrutural. Focalizou-se, ainda, o papel do controle de força em relação `a posição da ferramenta do manipulador na superfície do coração. Pretende-se que a principal contribuição deste trabalho seja demonstrar que o controlador híbrido segue as restrições impostas pela dinâmica do sistema coração-pulmão. / This paper refers to the simulation of a control system for a robotic manipulator to compensate the movements of the heart in minimally invasive cardiac surgery. In order to compensate the motion of the beating heart techniques are used to implement a hybrid position/force controller based on data and the movements of the heart obtained in vivo, used as references to the input of the system. Topics modeling robotic manipulators, and in particular, modeling the relationship between forces and displacements on the surface of the heart comprises the structural basis. The role of power control over the position of the manipulator tool on the surface of the heart. It is intended that the main contribution of this study is to show that the hybrid controller follows the restrictions imposed by the dynamics of the heart-lung system.

Dans cette recherche en psychologie clinique et en psychopathologie, nous interrogeons la nature et les caractéristiques de la position « méta ». Nous étudions plus spécifiquement le phénomène d’auto-observation qui constitue la position « méta », mais aussi les mécanismes psychiques qui sous-tendent ce fonctionnement : l’introjection du regard de l’autre, l’identification d’une part de soi à un autre, une dissociation fonctionnelle (ou une dissociation non-pathologique du Moi), l’auto-observation (où une part de soi observe une autre part de soi), la réflexivité, un dialogue interne. Nous nous intéressons également à l’évolution de la position « méta » au sein d’un dispositif de psychodrame psychanalytique de groupe composé de patients psychotiques, au regard des interactions avec les membres du groupe. / In this research in clinical psychology and psychopathology, we question the nature and characteristics of the « meta » position. We study more specifically the phenomenon of self-observation, which is the position « meta », but also the psychological mechanisms that underlie this operation : introjection the eyes of others the identification of a part of oneself to another, a functional separation (or non-pathological dissociation of the self) , self-observation (where self-hand observed another part of oneself) , reflexivity, an internal dialogue. We are also interested in the evolution of the position "meta" in a psychoanalytic psychodrama device group of psychotic pateints, in terms of interactions with group members.

Bakgrund: På intensivvårdsavdelningar finns olika rutiner kring huruvida endotrakealtubens position hos intuberade skall skiftas eller bibehållas i samma mungipa, då sidbyten kan leda till allvarliga komplikationer. Rutinen vid CIVA har varit att byta endotrakealtubens position på alla intuberade patienter en gång per dygn. Varken rutinen med skifte samt bibehållen position har utvärderats. Syftet med studien är att undersöka oralt intuberade patienters munhälsa vid bibehållen position av endotrakealtub under vårdtiden. Metod: Studien är en kvantitativ deskriptiv tvärsnittsstudie. Ett protokoll utformades för att undersöka hur stor andel av patienterna som får tryckskador i munnen med bibehållen tublägesposition. Resultat: Av totalt 85 oralt intuberade patienter utvecklade 10 rodnad och 7 sår medan 68 hade helt intakt slemhinna. Flest nyupptäckta sår uppkom efter 3-4 dagars intubering medan rodnader var jämnt fördelat. Slutsats: Endast ett fåtal patienter utvecklade tryckskador. Rutinen att bibehålla endotrakealtuben i samma position lämpar sig på patientkategorin på CIVA eftersom medelvårdtiden för intuberade är 3,2 dagar och flertalet extuberas under de 3 första dagarna. Klinisk betydelse: Studien ligger till grund för CIVA:s ändrade rutin att bibehålla endotrakealtubspositionen i samma mungipa och skulle på sikt kunna bidra till att minska samhällskostnaderna genom att reducera förekomsten av VAP och därmed patientvårdtiden / Background: Intensive care units have different routines whether the endotracheal tube position should be shifted or maintained in the same corner of the mouth. Repositioning of the tube can lead to serious complications. The routine at CIVA has been to change the endotracheal tube position in all intubated patients once per day. None of the routines have been evaluated. The objective of this study is to examine the oral health of intubated patients with maintained tube position. Method: The study is a quantitative descriptive cross-sectional study. A protocol was designed to examine the proportion of patients receiving pressure sores in the mouth. Results: Of a total of 85 orally intubated patients, 10 developed redness and 7 wounds while 68 had intact mucosa. The majority of the newly discovered sores occurred after 3-4 days of intubation. Conclusion: Only a few patients developed pressure sores. The routine to maintain the endotracheal tube in the same position is suitable for the patient category at CIVA since the average length of stay for intubated is 3.2 days and the majority were extubated during the first 3 days . Clinical significance: This study is the basis for CIVA's changed routine to maintain the endotracheal tube position in the same corner of the mouth and could eventually help to reduce the costs for society by reducing the incidence of VAP and thus patient care period.

This thesis includes a study of a touch-free sensor systems and different principles for measuring a magnetic field. An in-depth study was conducted to describe two important principles in these contexts, i.e. Magnetoresistance principle and the Hall Effect principle. A market evaluation of different sensor chips developed on these principles was conducted. Furthermore, the study should be linked to existing principles to determine the position of a rotating axis. Function tests show that the performance requirement for each component was met. The results based on verification tests show that it is important to have a better mechanical connection between drive and device. Temperature tests show that the system meets the project specification at room temperature, but large angular deviations occur in temperature change, especially when driving with short steps. This thesis can be continued by reprogramming the source code and developing new software that can control more parameters and make it more accurate at positioning. Another recommendation would be to investigate and compare other sensor chips because there are several sensors that can apply to the system. Further improvements can be made by performing more tests on the system. / Examensarbetet innefattar en studie om beröringsfritt givarsystem och olika principer för att mäta ett magnetfält. En fördjupad litteraturstudie utfördes för att förklara två viktiga principer i dessa sammanhang d.v.s. magnetoresistiva principen och hallgivarprincipen. En marknadsutvärdering av olika sensor-chip som utvecklats enligt dessa principer genomfördes. Vidare ska studien kopplas till kända principer för att bestämma positionen för en roterande axel. Funktionstester visar att prestandakravet för varje komponent uppfylldes. Resultaten baserade på verifieringstester visar att det är viktigt att ha en bättre mekanisk koppling mellan drivdon och enhet. Temperaturtester visar att systemet uppfyller projektets kravspecifikation vid rumstemperaturen men det uppkommer stora vinkelavvikelser vid temperaturförändring framför allt vid körning med korta steg. Detta arbete kan fortsättas genom omprogrammering av källkoden och utveckling av ny programvara som kan styra fler parametrar och göra det mer exakt vid positionsbestämning. En annan rekommendation skulle vara att undersöka och jämföra andra sensorchip eftersom det finns flera sensorer som kan tillämpa i systemet. Ytterligare förbättringar kan göras genom att utföra fler tester på systemet.

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This thesis focuses on the least-squares formulation of the non-collaborative and collabo- rative position location problems. For the non-collaborative problem, characterization encompassing the number of minima and the causes thereof is provided. Based on these efforts, we propose an improvement to the existing modified parallel projection method (MPPM), the reflected parallel projection method (RPPM). We show that the global minimum to the non-collaborative objective function can nearly always be found using the non-optimal reflected parallel projection method (RPPM). For the collaborative position location problem, we provide a characterization that shows a heavy tail of root-mean-square (RMS) error due to a small percentage of simulated node/anchor layouts when solved by the iterative parallel projection method (IPPM). We provide an identification technique that successfully identifies most layouts that show large RMS error followed by a proposed solution to improve the accuracy in those problematic layouts. Finally, we report the findings of a measurement campaign that validates our Gaussian model for line-of-sight (LOS) noise and shows that, for these particular measurements, non-line-of-sight (NLOS) noise is difficult to accurately model and can be very large. This research was supported by a Bradley Fellowship from Virginia Tech's Bradley Department of Electrical and Computer Engineering, made possible by an endowment from the Harry Lynde Bradley Foundation. / Master of Science

Real-time, virtual and mixed reality systems have diverse uses for real-world data visualization, representation, and remote collaboration in distant learning settings, especially in universities. Design of such systems involves challenges in mapping the real world data and physical world structure accurately to digital form of physical space, also called as virtual models. Researchers have created similar systems using multiple cameras, stereo cameras, accelerometers, and motion detectors. This report presents a platform to detect and track real-time locations of people present in buildings and map their location information into virtual models as avatars using omni-directional cameras installed in the physical space. These models were created as part of the Mirror Worlds project. The project infrastructure is funded by National Science Foundation. This infrastructure enables users to connect virtual and physical aspects of the environment through a coordinate-based data networking system to enable interaction with the rest of the system including environment objects and other users. This is an interdisciplinary project where students from various departments have worked on the development of virtual model of the Moss Art Center and Torgersen Hall in Unity / X3D. Some students from the Department of Computer Science have developed a coordinate-based data networking system. The prototype of a detection and tracking algorithm to extract the location information was developed using background subtraction in MATLAB. The proposed approach was developed using the combination of background subtraction and neural networks along with heuristics based on spatial information about the physical space. The system was scaled to work across multiple buildings, extract the location information of people present in the physical space, and map location information into shared virtual space as an avatar. The concept of remote presence was extended to create a collaborative object manipulation application using Leap Motion controller. Effects of fidelity were evaluated to perform the collaborative object manipulation task in shared virtual space based on user study conducted for this application. Since no annotated people video dataset is publicly available with overhead view from omni-directional cameras, three videos were annotated manually to test the performance of the approach. The current approach almost works at near real-time rates. All three video sequences were evaluated to compute frame based detection accuracy. Precision and recall obtained for the first video sequence of people detection is 93.85% and 95.06% respectively. / Master of Science / Globalization and the advancements in the technological world pose the need for people working across different geographical regions to communicate not just over video conferencing but having remote presence which provides a stimuli to users’ senses to give the feeling of being at other location. The common approach to create remote presence application is by creating a real-time, virtual and mixed reality system. These mix reality systems have diverse uses for real-world data visualization, representation, and remote collaboration in distant learning settings, especially in universities. Design of such systems involves challenges in mapping the real world data and physical world structure accurately to digital form of physical space, also called as virtual models. Researchers have created similar systems using multiple cameras, depth sensors, accelerometers, and motion detectors. This work introduces a platform to detect and track real-time locations of people present in buildings and map their location information into virtual models as avatars using cameras installed in the physical space. The proposed solution uses combination of background subtraction and neural networks with some heuristics based on spatial information about the physical space. The system is scaled to work across multiple buildings. The concept of remote presence was extended to create a collaborative object manipulation application. Three videos were annotated manually to test the performance of the proposed approach.