REIS , Inês Maria de Oliveira. Os sentidos do adoecer: refazendo o percurso Freudiano. 2008. 144 f. Dissertação (Mestrado em Psicologia) – Universidade Federal do Ceará, Departamento de Psicologia, Programa de Pós-Graduação em Psicologia, Fortaleza-CE, 2008. / Submitted by moises gomes (celtinha_malvado@hotmail.com) on 2012-01-17T12:54:36Z No. of bitstreams: 1 2008_dis_IMDOReis.PDF: 451366 bytes, checksum: d83321b82d86ecafc6b8045cd2c90b9a (MD5) / Approved for entry into archive by Maria Josineide Góis(josineide@ufc.br) on 2012-03-08T12:07:26Z (GMT) No. of bitstreams: 1 2008_dis_IMDOReis.PDF: 451366 bytes, checksum: d83321b82d86ecafc6b8045cd2c90b9a (MD5) / Made available in DSpace on 2012-03-08T12:07:26Z (GMT). No. of bitstreams: 1 2008_dis_IMDOReis.PDF: 451366 bytes, checksum: d83321b82d86ecafc6b8045cd2c90b9a (MD5) Previous issue date: 2008 / By referring to a psychoanalytic approach,this reaserch proposes a bibliographic rewiew about the signs of sickness: remaking the Freud investigation,choosing as goals to investigate the meanings of psychological diseases, their mecanisms and psychological manifestations involved in the scope of neurotic diseases.The methodology is based on a qualitative reseach done by the analysis of content of a total of 75 selected summaries. In each of these summaries, the meanings of the content are reseached. Ten articulated the areas were chosen:sickness, pulsion, life/death, pain/suffering, loss/mourning, symptom, trauma, narcisism, compulsion to repetition, body, being emphasized the following areas: sickness, pulsion, symptom and body.The reseach points out the relation between the psychological sickness and the opression of the lust,reflecting the existance of the mecanism of sickness and the formation of the symptom.The process of sickness involves a lack of sexual desire, and also a misfunction in the living of the pulsions of life and death, and this fragmentation leads to partial pulsions. The destinies of the pulsions suggest a connection with the psychological sickness,causing pathological manifestations like traumatic neurosis,compulsion to repetition,force of resistences,neurotic contents and their state of morbid suffering. / Ao tomar referência à abordagem psicanalítica, esta pesquisa se propõe a uma revisão bibliográfica sobre Os Sentidos do Adoecer: refazendo o percurso freudiano, escolhendo como objetivos investigar os sentidos, os mecanismos e as manifestações envolvidas no âmbito do adoecer psíquico. A metodologia baseia-se numa pesquisa qualitativa feita através de uma análise de conteúdo de um total de 75 resumos selecionados. Buscam-se, em cada resumo, os significados de conteúdo; escolhem-se dez áreas temáticas articuladas: Adoecer, Pulsão, Vida/Morte, Dor/Sofrimento, Perdas/Luto, Sintoma, Trauma, Narcisismo, Compulsão à repetição, Corpo, priorizando-se quatro dessas áreas que apresentam uma ligação maior com o estudo, quais sejam: Adoecer, Pulsão, Sintoma e Corpo. A pesquisa aponta a relação do adoecer psíquico com o “represamento da libido”, refletindo a existência do mecanismo de adoecimento e da formação do sintoma. O processo de adoecimento envolve uma dessexualização das funções egóicas (as de autopreservação e as pulsões libidinais), além de ocorrer também uma vivência desfusional das pulsões de vida e de morte, tendo as pulsões parciais como conseqüências dessa fragmentação. Os destinos das pulsões sugerem uma ligação com o adoecimento psíquico, provocando manifestações patológicas como as neuroses traumáticas, os fenômenos da compulsão à repetição, a força das resistências, a presença dos conteúdos neuróticos e seus estados mórbidos de sofrimento.

A neuroinflamação vem sendo estudada através da administração aguda, central ou periférica, de lipopolissacarídeos bacterianos (LPS) em roedores. A administração de LPS causa uma mudança na resposta imune do animal, aumentando os níveis de citocinas e outras quimiocinas inflamatórias. Essas alterações levam a um estado comportamental do tipo doente, que tende a ser extinto 24 h depois da administração de LPS, momento no qual se pode visualizar o desenvolvimento de um comportamento do tipo deprimido no animal. O hiperosídeo (HYP) é um flavonoide glicosilado, encontrado em diversas espécies vegetais e apresenta efeito do tipo antidepressivo, atividade citoprotetora, antioxidante e anti-inflamatória em roedores. O objetivo desse trabalho foi avaliar o efeito do flavonoide hiperosídeo (HYP) no modelo do comportamento de doente e do tipo deprimido induzidos pela administração de LPS em camundongos e sobre os níveis hipocampais de citocinas (IL-6, TNF, IFN-γ, IL-12 e IL-10) e quimiocina MCP-1. O modelo consistiu na exposição dos animais a uma sessão de 5 min de natação forçada (estímulo estressor) com posterior administração de LPS (600 μg/kg, i.p.) ou solução salina (10 mL/kg, i.p., SAL, animais controle do modelo). O comportamento de doente foi avaliado em campo aberto, através da medida do número de cruzamentos e score de sintomas, 06 e 24 h após a administração de LPS. O comportamento do tipo deprimido foi avaliado pela medida da imobilidade no teste de suspensão pela cauda (TSC) 24 h após a administração de LPS. Os tratamentos imipramina (IMI, 20 mg/kg), HYP (20 mg/kg) ou solução salina 10 mL/kg (grupo controle do tratamento) foram administrados (i.p.) 30 min antes (protocolo profilático) ou 5 h e 30 min depois (protocolo terapêutico) da administração de LPS ou SAL. Os níveis hipocampais de citocinas foram medidas por citometria de fluxo nos animais eutanasiados uma hora após o TSC. A administração profilática de HYP aumentou 12 os níveis de todas as citocinas tanto no grupo LPS quanto no grupo SAL. A análise da correlação citocinas pró-/anti-inflamatórias demonstrou que o tratamento profilático HYP resultou em uma correlação positiva IL-6/IL10 e TNF/IL-10 tanto nos animais SAL quanto LPS. A administração terapêutica de HYP aumentou somente os níveis de IL-10 e resultou em uma correlação IL-6/IL-10 positiva apenas no grupo SAL. Nos animais do grupo LPS, o tratamento terapêutico HYP aumentou os níveis de MCP-1 e resultou numa correlação positiva TNF/IL-10. O tratamento profilático HYP preveniu parcialmente o desenvolvimento do comportamento de doente, diminuindo o score de sintomas e o comportamento do tipo deprimido no grupo LPS. O tratamento terapêutico HYP preveniu o desenvolvimento do comportamento do tipo deprimido apenas no grupo SAL. A administração profilática de IMI nos animais SAL não alterou os níveis de IL-6, IL-10 e TNF, mas resultou em correlações IL-6/IL-10 e TNF/IL-10 positivas. Nos animais que receberam LPS, a administração profilática de IMI somente diminuiu os níveis de IL-6 e TNF, sem apresentar nenhuma correlação entre os níveis de citocinas. A administração terapêutica de IMI não alterou os níveis de nenhuma citocina, porém resultou em uma correlação TNF/IL-10 positiva. O tratamento profilático IMI preveniu tanto o desenvolvimento do comportamento de doente como do tipo deprimido. O tratamento terapêutico com IMI não reverteu os prejuízos induzidos pela administração de LPS, nem no comportamento de doente nem no do tipo deprimido. Em conclusão, os dados deste trabalho confirmam o efeito do tipo antidepressivo de hiperosídeo em camundongos e demonstram que o tratamento profilático com HYP tem efeito protetor parcial contra a manifestação dos sintomas de doente e comportamento do tipo deprimido induzidos pela natação forçada e administração de LPS. A ação do HYP pode estar relacionada ao aumento dos níveis hipocampais da citocina antiinflamatória IL-10. / The neuroinflammation has been studied through acute, central or peripheral administration of bacterial lipopolysaccharides (LPS) in rodents. LPS alters the animal immune response increasing the cytokines and others inflammatory chemokines levels. These alterations generate a group of symptoms and behavioral changes known as sickness behavior, which tends to be extinct 24 h after LPS administration when the animals develop a depressive-like behavior. Hyperoside (HYP) is a glycosylated flavonoid that present antidepressant, cytoprotective, antioxidant and anti-inflammatory properties in rodents. The aim of this study was to evaluate the HYP effects on sickness and depressive-like behaviors induced by LPS administration in mice as well as to investigate its effect on hippocampal cytokines (IL-6, TNF, IFN-γ, IL-12 e IL-10) and chemokine MCP-1 levels. The model consisted of a 5 min forced swimming session (stressor stimuli) with posterior LPS (600 μg/kg, i.p.) or saline (10 ml/kg, i.p., SAL) administration. The sickness behavior was assessed in the open field test by measuring the number of crossings and by scoring symptoms, 06 and 24 h after LPS administration. The depressive-like behavior was evaluated by measuring the immobility time in the tail suspension test (TST) 24 h after LPS administration. The treatments imipramine (IMI, 20 mg/kg), HYP (20 mg/kg) or saline 10 mL/kg (treatment control group) were administered (i.p.) 30 min before (prophylactic protocol) or 5 h and 30 min after (therapeutic protocol) LPS or saline (SAL - experiment control) administration. The cytokines levels were measured by flow cytometry in animals euthanized by decapitation 1 h after TST. The prophylactic administration of HYP increased all cytokines in both LPS and SAL groups, and resulted in an IL-6/IL-10 and a TNF/IL-10 positive correlation in both SAL and LPS animals. The therapeutic administration of HYP increased IL-10 levels, with an IL-6/IL10 positive correlation in SAL group only. In LPS animal group, the therapeutic 14 administration of HYP increased the MCP-1 levels and resulted in a TNF/IL-10 positive correlation. The prophylactic HYP did not prevent the reduction on spontaneous locomotion induced by LPS but decreased the symptoms score in LPS group and the depressive-like behavior in both LPS and SAL groups. The therapeutic HYP did not revert the sickness behavior and prevented the depressive-like behavior only in SAL group. The prophylactic IMI decreased IL-6 and TNF without any correlation between cytokines levels in animals that received LPS. In SAL animals, the prophylactic administration of IMI did not alter the cytokines levels but resulted in an IL-6/IL-10 and TNF/IL-10 positive correlations. The therapeutic IMI did not alter any cytokine levels, but resulted in a positive TNF/IL-10 correlation. The prophylactic IMI prevented both sickness and depressive-like behavior in LPS and SAL groups. The therapeutic IMI did not revert any LPS impairment. In conclusion, this study confirmed the antidepressant–like effect of hyperoside in mice and demonstrated that prophylactic treatment with this flavonoid partially protect the animals against sickness and depressive-like behaviors induced by LPS combined with forced swimming stress. Ability of HYP to increase the anti-inflammatory cytokine IL-10 hippocampal levels may underlies its effects on this model.

A study was carried out to understand the process of health and sickness in a sample of rural workers located at the Santa Maria Municipality, district of Arroio do So (RS, Brazil). The conceptual background of the study is based upon the theory of social representation. This theory consists of the beliefs, values and norms that influence not only thoughts but also behavior of the people. Needless to say that it is important to take into account the social, economical, political and cultural context of society where people live and work. This context affects social representations of the people. Q-methodology was employed to generate (by qualitative techniques) and analyze (by quantitative techniques) the information. Q is aimed at revealing the inner world of the people, a complex system composed of values, beliefs, thoughts, and so on. In this sense Q is an appropriate approach to study social representations. The implementation of the methodology implies 7 stages that can be reduced to 3 important moments. In the moment one, 10 people were interviewed as qualified informants, to develop the set of statements to be sorted through content analysis (Bardin, 1977). In the second stage, 34 rural workers were interviewed and asked to rank-order opinion statements about why they perceive the health and sickness process. In stage three the data was analyzed and interpreted using a special statistical software program called PCQ. The results of analysis content show that people who live and or work in the country relate to their environment in a particular way that affects their lives totally. Consequently, social representations of health and sickness are influenced with this interaction. Three different categories emerged: a) the process of health and sickness depends of live conditions and habits, b) the process of health and sickness depends of work characteristics, and c) cultural practices related to health and sickness. A matrix was built upon these 3 categories in order to develop the statements. The results of factorial analysis show that 3 factors emerged. They were labeled: a) health and integral prevention, b) popular health system, and c) work-health relation. These factors are related to the categories coming from the content analysis. Taking into account that there are differences between the urban and rural contexts, and that social representations are dynamic and heterogeneous, public health politics should consider them when rural development programs are planned. This will lead nicely to develop programs well suited to the rural conditions, needs and demands. It is important to avoid copying to the rural context what is being done in the urban one. / Este estudo foi desenvolvido para entender o processo saúde-doença de um grupo de trabalhadores rurais do distrito de Arroio do Só, em Santa Maria (RS, Brasil). A base conceitual do estudo é a Teoria das Representações Sociais. A referida teoria atribui valor às crenças, ao significado construído socialmente, à cultura e ás normas que influenciam não só o pensamento, mas também o comportamento das pessoas. É importante considerar o contexto social, econômico, político e cultural da sociedade em que as pessoas vivem e trabalham e como esse contexto afeta as representações sociais dos indivíduos. A metodologia Q foi utilizada para suscitar (por técnicas qualitativas) e analisar (por técnicas quantitativas) as informações. A referida metodologia apresenta como objetivo revelar o mundo interior das pessoas, este considerado um sistema complexo composto de valores, crenças e pensamentos. Nesse sentido, Q é uma abordagem apropriada para estudar as representações sociais. A implementação da metodologia implica sete (7) passos que podem ser reduzidos a três (3) momentos importantes. No primeiro momento, dez (10) pessoas foram entrevistadas como informantes qualificados para desenvolver o conjunto de opiniões a ser classificado pela análise de conteúdo (Bardin, 1977). No segundo momento, trinta e quatro (34) trabalhadores rurais foram entrevistados e solicitados a classificar afirmativas de acordo com sua percepção acerca do processo saúde-doença. No terceiro momento, os dados foram analisados e interpretados por meio de um programa especial de software estatístico, denominado PCQ. Os resultados da análise de conteúdo mostram que as pessoas que moram ou trabalham na área rural, relacionam-se com o seu meio de uma maneira especial, que afeta integralmente suas vidas. Conseqüentemente, as representações sociais de saúde e doenças são influenciadas por tal interação. Três diferentes categorias surgiram: a) o processo saúde-doença resultante das condições e dos hábitos de vida; b) o processo saúde-doença resultante das características do trabalho; c) práticas de cuidado relacionadas à saúde e à doença. Uma matriz sobre essas três categorias foi elaborada para desenvolver as afirmativas. Os resultados da análise fatorial mostram três (3) fatores: a) saúde é a prevenção integral; b) sistema de saúde popular; c) relação trabalho-saúde. Estes fatores são relacionados às categorias provenientes da análise de conteúdo. Como há diferenças entre os contextos urbano e rural e as representações sociais são dinâmicas e heterogêneas, a política pública de saúde pública deveria considerá-las, quando os programas de desenvolvimento rural são planejados. Tal procedimento pode levar a desenvolver programas adequados às condições rurais, às suas necessidades e às suas demandas. É importante não copiar para o contexto rural o que é feito no contexto urbano.

Inom äldreomsorgen idag finns det utmaningar iform av hög arbetsbelastning och dåliga arbetstider, vilket innebär att rekrytering är svår i verksamheterna. Den ökade arbetsbelastningen orsakar sjukskrivning, vilket i sin tur leder till mer sjukfrånvaro på arbetsplatsen. Studien bygger på enkätundersökningar hos personalen och intervjuer med andra företag för att dela med sig av tankar och arbetssätt som kan bidra till att utveckla planeringsprocessen. Studien ger idéer och verktyg för verksamheten om vad de behöver göra och förändra för att bli bättre och använda de resurser som redan finns tillgängliga i verksamheten på ett effektivt sätt. Syftet med studien är att kartlägga och förbättra planeringsprocessen för frånvaro på grund av sjukfrånvaro för att använda av alla resurser på bästa sätt i verksamheten utifrån teorier som ligger till grund för att belysa olika områden inom problemområdet och sedan hitta lösningar och verktyg för att förbättra processen. Studien har dragit slutsatsen att en uppdelning av uppgifter i dagens process kan underlätta personalens arbete när en ny roll skapas som hanterar den dagliga planeringen. Problemområden har kartlagts och presenterats tillsammans med en lösning baserad på principerna om lean filosofi och hörnstenarna. Processerna som utvecklats i studien bygger på skapandet av en ny roll för att underlätta och lindra det dagliga arbetet hos personalen. / In the field of care for the elderly today there are challenges, such as high workload and poor working hours, which means that recruitment is difficult in the operations. The increased workload causes sick leave, which in turn leads to more sickness absence in the workplace. The study is builds on surveys of the staff and interviews with other companies in order to share thoughts and working methods that can help to develop the planning process. The study provide ideas and tools for the business about what they need to do and change to get better and to use the resources already available in the business on an effective basis. The aim of the study is to map and improve the planningprocess of absence due to sickness absence in order to use best of all resources in the business based on theories that form a basis for highlighting different areas of the problem area, and then finding solutions and tools to improve the process. The study has concluded that a division of tasks into today's process can facilitate the work of the staff when a new role is created that manages the daily planning. Problem areas have been mapped and presented together with a solution based on the principles of lean philosophy and the cornerstones. The processes developed in the study are based on the creation of a new role to facilitate and relieve the daily work of the staff.

Regular physical activity reduces the risk of many chronic diseases. Consequently, the promotion of it and particular types (e.g. walking and cycling for travel), have become a priority for governments seeking to improve health and constrain rising demand on health services. Despite this many uncertainties persist. The aim of this thesis is to address two particular areas of uncertainty: a) the association of walking and cycling for travel with indices of health and well-being; b) and the extent to which increases in physical activity will reduce need for health and social care. The first part of my thesis consists of three studies that describe the health benefits associated with walking and cycling to work among working age adults. The first is a longitudinal study of the associations between maintenance of active commuting with sickness absence and well-being using the Commuting and Health in Cambridge dataset. The second, using the same dataset, describes the longitudinal associations between maintenance of active commuting and self-reported body mass index. Building on this, the third study using a large cohort study (the Fenland Study) with detailed characterisation of diet and physical activity (including objective measurement) describes the baseline associations between active commuting and objective measures of adiposity. The second part of my thesis describes the development of a combined microsimulation multi-state life table model that is used to characterise the effects of a population ‘shift’ in physical activity on the burden of six major diseases at the population-level. Specifically, it seeks to better describe the effect of increases in physical activity on healthcare need considering not just the effect of physical activity on disease incidence but also the effect on healthcare need arising from consequent survival to an older age (at which disease incidence is higher), and contrasts this with a method that does not make allowance for increased survival. The findings of this thesis provide evidence of the importance of walking or cycling to work in maintaining or improving the health and well-being of working age adults. It suggests that increases in physical activity, even after allowance for increased survival, are likely to reduce need for healthcare, although the reductions in need are less than might be assumed when allowance is not made for increased survival. Taken together this work provides a stronger empirical basis to inform public health practice. A stronger ‘health case’ for active travel can be made. The benefits of which should be communicated to individuals choosing how to travel as well as policy makers and others who can influence the determinants of active travel. It also provides a more realistic and nuanced understanding of how increases in physical activity may affect future healthcare need.

Virtuell verklighet (VR) har under de senaste åren fått en uppsving i popularitet. Rörelsesjuka i VR har länge varit ett problem och är idag fortfarande ett stort hinder för kommersiell succé. Detta arbete ämnar till att implementera stöd för Oculus Rift i programmet Configura, och utvärdera navigering med handkontroll i en VR-miljö. Fokuset ligger på att hitta lämpliga gång- och rotationshastigheter för effektiv navigering med handkontroll, och effekten hastigheterna har på rö- relsesjuka. En användarstudie genomfördes där personer testade olika gång- och rotationshastigheter i olika tester med ökande svårighetsgrad i navigering. Resultaten från användarstudien visar på att i alla hastigheter upplevde testpersonerna allvarliga symptom av rörelsesjuka. Det fanns även indikationer att användare med lägre hastigheter presterar bättre. / Virtual Reality (VR) have risen in popularity during the last years. Motion sickness however have been a big problem and still is an obstacle for commercial success. This thesis work aims to implement VR-support in the space planning program Configura, and evaluate navigation with a controller in a VR-environment. The focus of this study is to find suitable walking and rotational speeds for effective navigation with a controller, and the effects different speeds have on motion sickness. A user study was preformed where users tested different speeds in tests with an increasingly difficulty in navigation. The results from the study shows that people had severe symptoms of motion sickness in all speeds. There were also indications that lower speeds made people perform better.

People call the year of 2016 as the year of virtual reality. As the world leading tech giants are releasing their own Virtual Reality (VR) products, the technology of VR has been more available than ever for the mass market now. However, the fact that the technology becomes cheaper and by that reaches a mass-market, does not in itself imply that long-standing usability issues with VR have been addressed. Problems regarding motion sickness (MS) and motion control (MC) has been two of the most important obstacles for VR technology in the past. The main research question of this study is: “Are there persistent universal access issues with VR related to motion control and motion sickness?” In this study a mixed method approach has been utilized for finding more answers related to these two important aspects. A literature review in the area of VR, MS and MC was followed by a quantitative controlled study and a qualitative evaluation. 32 participants were carefully selected for this study, they were divided into different groups and the quantitative data collected from them were processed and analyzed by using statistical test. An interview was also carried out with all of the participants of this study in order to gather more details about the usability of the motion controllers used in this study. The results of this study has validated several existing frameworks for VR. And in conclusion, this study has also shown that both previous motion sickness experiences and gender factors weren’t significant in terms of general accessibility issues on PCVR platforms. There are hints showing that the VR technology on PC platform could be universal accessible, since both of the quantitative and qualitative results has provided some evidences supporting this finding. However, more similar studies need to be carried out in order to identify more possible factors that would give an impact on user experiences in VR. The results of this study has also given implications of that today’s VR technology is developing on the right track and it could slowly become adopted by the mainstream and mass-market in the future.

La simulation de conduite est fortement utilisée dans la recherche et le développement pour l'industrie automobile. Les simulateurs de conduite sont utilisés pour évaluer les prototypes véhicules pour la dynamique du véhicule et les systèmes d'aide à la conduite. Cependant, l'utilisation des simulateurs de conduite induit une problématique scientifique qui peut limiter son développement. En raison de son principe même, le simulateur de conduite ne restitue pas des mouvements du véhicule à l'échelle 1. Ce verrou cause des phénomènes de mal du simulateur qu'il est important d'étudier.Cette thèse propose d'étudier des méthodes et outils à mettre en œuvre dans les simulateurs de conduite statique ou dynamique. De cette mise en œuvre, des études sur le mal du simulateur sont menées grâce à des mesures objectives (via un capteur de suivi de mouvement, plate-forme de stabilité du corps, électromyographie) et subjectives (par l'intermédiaire de questionnaires). Des solutions algorithmiques et matérielles sont proposées et évaluées dans le contexte de la simulation de conduite.Les approches proposées dans cette thèse pour réduire le mal du simulateur sont:- Elaborer et évaluer les algorithmes de contrôle de la plate-forme mobile hexapode: sept algorithmes différents sont mis en œuvre.- Mesurer les effets liés au mal de simulateur sur les sujets aux niveaux vestibulaire, neuromusculaire et posturale.- Evaluer l'influence de l'implication des sujets sur le mal de simulateur (conducteurs et passagers). / Simulation has been intensively involved nowadays in research and development for automotive industry. Driving simulators are one of those simulation techniques which are used to evaluate the prototypes for the vehicle dynamics and driving assistance systems. However with the driving simulator, there is a lock associated with its use. Because representing a permanent scenario as scale 1 is quite difficult. Because of that difficulty, motion/simulator sickness is an inevitably important topic to study.This thesis proposes to explore methods and tools to implement in static or dynamic simulators. In this implementation, studies of simulator sickness are conducted with objective measures (via a motion tracking sensor, platform for body stability, electromyography) and subjective (through questionnaires). These algorithmic or hardware solutions studies should be defined and applied at simulators. The proposed approaches to reduce or avoid simulator sickness in this thesis are:- Building control algorithms of motion hexapod platform: seven different algorithms are implemented.- Measuring the effects of inertia on subjects at vestibular, neuromuscular and postural levels.- Assessing the involvement of subjects (drivers and passengers).

Dans un environnement virtuel, l’interaction fait partie des éléments essentiels qui permettent de procurer à l’utilisateur immersion et sentiment de présence. L’une des tâches essentielles que l’on souhaite effectuer est l’action de se déplacer. Pour adresser ce problème, on distingue deux approches. La recherche du réalisme consiste à tenter de reproduire le réel. Dans le cas du déplacement, cela consiste à donner la possibilité à l’utilisateur de marcher, ou de se servir d’un véhicule. Paradoxalement, cette solution qui semble si simple et naturelle nécessite en pratique l’utilisation de machines complexes et encombrantes, conçues pour faire ressentir à l’utilisateur qu’il se déplace, tout en maintenant sa position dans un périmètre délimité. Les métaphores ou les techniques d’interactions sont des mécanismes abstraits qui permettent de réaliser des tâches ambitieuses de manière efficace. Par exemple un rayon de sélection sortant de l’index de l’utilisateur est une technique d’interaction. C’est la transposition au domaine de la réalité virtuelle du concept d’interface graphique que l’on trouve dans les ordinateurs de bureau. On retrouve donc des problématiques d’intuitivité et d’ergonomie. Dans cette thèse, c’est cette approche qui a été retenue. Pour une plus grande intuitivité, nous proposons l’utilisation de périphériques nomades, avec une nouvelle technique d’interaction appelée Space Scrolling, utilisant un smartphone comme périphérique d’entrée et tirant parti de la gestuelle tactile familière des smartphones. Pour résoudre le problème du cyber-malaise, nous avons élaboré deux techniques, Head Lock et Avatar Follow. Dans Head Lock, on cherche à optimiser les rotations car c’est la composante de déplacement qui influe le plus sur le mal du simulateur. Dans Avatar Follow, on ajoute une couche de gestion automatique de la dynamique des déplacements afin d’empêcher les accélérations brutales. Nos différentes techniques de déplacement, ont été évaluées. Nous avons mis en évidence l’existence de catégories d’utilisateurs aux comportements et perceptions diamétralement opposés, novices et experts ou familiers, tout en leur apportant des solutions de déplacement adaptées. / In a virtual environment, interaction is one of the essential elements to provide the user immersion and feeling of presence. One of the most essential task one would like to achieve is the act of displacement. To address this problem, there are two approaches. The quest for realism involves trying to reproduce the reality. In the case of displacement, it consist in allowing the user to walk, or to use a vehicle. Paradoxically, this solution which seems so simple and natural requires in practice the use of complex and cumbersome machines, designed to make the user feel that he is moving, while keeping his position in a defined area. Interaction techniques or metaphors are abstract mechanisms to carry out ambitious task effectively. For example, pointing at and object with a selection ray which extend a finger, is an interaction technique. This is the transposition to the field of virtual reality of the concept of graphical interface that can be found in desktop computers. We thus encounter the same problems of intuitiveness and ergonomics. For better intuitiveness, we propose the use of nomad devices, with a new interaction technique called Space Scrolling, using a smartphone as the input device and taking advantage of the familiar smartphone touch gestures. In order to solve the problem of cyber-sickness, we developed two techniques, Head Lock and Avatar Follow. With Head Lock, we seek to optimize the rotations because it is the part of displacement that most affects the simulator sickness. With Avatar Follow, we add a layer of automatic management of dynamic movements to prevent brutal accelerations. Our different navigation techniques, were evaluated. We have demonstrated the existence of categories of users with diametrically opposed behaviors and perceptions, novices and experts or familiar, while providing tailored travel solutions.

L’accident de désaturation (ADD) est un accident de plongée lié à la charge en gaz diluants pendant la plongée, et à la formation de bulles dans l’organisme au cours de la décompression. Il est susceptible d’engendrer des séquelles neurologiques. Au cours de plongées utilisant l’hydrogène comme gaz diluant, la diminution de la charge tissulaire en hydrogène par l’inoculation au niveau de l’intestin de bactéries métabolisant ce gaz réduit le risque d’ADD.L’objectif de ce travail était d’évaluer si inversement : 1) la fermentation intestinale lors de la plongée peut favoriser la survenue d’un ADD, par l’intermédiaire de la production d’hydrogène endogène ; 2) la stimulation chronique de la fermentation avant plongée majore le risque d’ADD.Nos résultats sont en faveur d’un effet dual de la fermentation intestinale sur la décompression. Délétère à court terme lors de la plongée, la fermentation intestinale prolongée pourrait être favorable en dehors de la plongée en prévenant la survenue et la sévérité d’un ADD. L’hydrogène, molécule aux propriétés antioxydantes, et le butyrate, un acide gras à chaîne courte, sont en effet deux produits de la fermentation des hydrates de carbone qui ont des vertus neuroprotectrices.La prévention des accidents de désaturation pourrait passer par une exclusion des plongeurs présentant une fermentation importante le jour de la plongée, une élimination des gaz produits au niveau de l’intestin ou une modification de l’alimentation dans les 24 heures précédant une plongée. En revanche, tous les facteurs susceptibles de modifier le microbiote intestinal et d’augmenter la fermentation, en dehors de la plongée, pourraient être testés en prévention de l’ADD. En outre, l’hydrogène et le butyrate pourraient jouer un rôle bénéfique dans le cadre du traitement de l’ADD / Decompression sickness (DCS) is a diving accident related to the dissolution of diluent gas in blood and tissues during a dive, followed by bubble formation in the body during decompression. It can lead to neurological damage. In dives using hydrogen as the diluent gas, the concentration of hydrogen in the tissues can be reduced by the presence in the gut of bacteria capable of metabolising this gas and this reduces the risk of DCS.The aim of this work was conversely to check if: 1) fermentation in the gut at the time of diving could exacerbate DCS as a result of endogenous hydrogen generation; 2) long-term stimulation of fermentation before diving raises the risk of DCS.Our findings point to a two-edged effect of intestinal fermentation on decompression: although deleterious in the short term, i.e. at the time of diving, longer-term intestinal fermentation between dives might have a positive effect by preventing the occurrence of DCS and limiting its severity. Indeed, hydrogen which has antioxidant properties and butyrate, a short-chain fatty acid, are both by-products of the fermentation of carbohydrate and both have neuroprotective activity.DCS prevention could be promoted by excluding divers exhibiting strong fermentation on the day of a dive, by the elimination of gases being produced in gut or by modification of diet in the 24 hours before a dive. On the other hand, any factor that might affect the gut microbiota and stimulate fermentation between dives could be tested to investigate its potential in protecting against DCS. Furthermore, hydrogen and butyrate could play a positive role when it comes to treating DCS