La théorie polyvagale (Porges, 2007) propose la flexibilité physiologique commecorrélat des compétences socio-émotionnelles. Cette flexibilité physiologique est en partie déterminée par les interactions coeur-cerveau mesurables par la variabilité cardiaque de haute fréquence (HF-HRV). Selon cette théorie, une plus haute HF-HRV devrait être associée à une meilleure perception des émotions et à des comportements davantage prosociaux. Si plusieurs données tendent à corroborer cette proposition, aucune étude ne permet de tester précisément ces hypothèses. Nous avons donc mené une série d’études ayant pour but de les tester. Dans une première étude, nous avons testé le lien entre HF-HRV et comportement prosocial mesuré par le niveau de coopération. Le niveau de HF-HRV prédisait le niveau de coopération mais dans un contexte spécifique. Notre deuxième étude avait pour but de tester le lien entre HF-HRV et perception des émotions. Ici, le niveau de HF-HRV ne prédisait pas de meilleures performances en reconnaissance d’émotions. Nous avons ensuite voulu tester un éventuel lien causal existant entre HF-HRV et prosocialité. Pour cela nous avons réalisé une expérience (étude 3) visant à manipuler la HF-HRV par biofeedback. Le biofeedback augmentait la HF-HRV mais uniquement chez les individus avec une faible ligne de base. L’étude 4 testait si manipuler la HF-HRV par biofeedback modulait le comportement de coopération. Nous n’avons pas répliqué nosrésultats quant à l’efficacité du biofeedback et n’avons donc pas observé d’effet sur la coopération. La cinquième et dernière étude permettait de tester si manipuler la prosocialité modulait le niveau de HF-HRV. Nous n’avons pas observé d’effet de notre manipulation expérimentale sur la HF-HRV. En conclusion, la prédiction de la théorie polyvagale est corroborée par les données empiriques quant au lien entre HF-HRV et comportements prosociaux mais aucune confirmation n’a pu étayer le rapport entre perception des émotions et HF-HRV. Dans le cas des manipulations expérimentales à court terme, aucune relation causale entre HF-HRV et comportements prosociaux n’a été observée. / The polyvagal theory (Porges, 2007) proposes physiological flexibility as thecorrelate of socio-emotional skills. This physiological flexibility is partially determined by heart-brain interactions measurable by heart rate variability of high frequency (HF-HRV). According to this theory, higher HF-HRV should be associated with better perception of emotions and more prosocial behaviors. If more and more data tend to support this proposal, no experiment allowed to accurately test these hypotheses. We therefore carried-out a set of studies in order to test them. In a first study, we tested the link between HF-HRV and prosocial behavior measured by the level of cooperation. HF-HRV level predicted the level of cooperation but in a specific context. Our second study was designed to test the link between HF-HRV and perception of emotions. Here, the HF-HRV level did not predict better performance in recognition ofemotions. We then wanted to test a possible causal link existing between HF-HRV and prosociality. For this we performed an experiment (Study 3) to manipulate HF-HRV by biofeedback. Biofeedback increased HF-HRV levels but only in low baseline individuals. Study 4 tested whether manipulating HF-HRV by biofeedback could modulate the behavior of cooperation. We did not replicate our findings about the effectiveness of biofeedback and therefore did not observe any effect on cooperation. The fifth and final study allowed to test whether manipulating prosociality modulated the level of HF-HRV. We did not observe any effect of our experimental manipulation on HF-HRV. In conclusion, the prediction made by the polyvagal theory about the link between HF-HRV and prosocial behaviors is corroborated by empirical data but data does not support the link between the perception of emotions and HF-HRV. Short-term experimental manipulations did not reveal any causal relationship between HF-HRV and prosocial behaviors.

The master’s thesis is focused on the possibilities of measuring heart rate of ECG signal and its use in therapeutic game of ECG biofeedback. This thesis describes the way of measuring ECG with acquisition unit Biopac and analyzes signal processing for measurement of heart rate – algorithms of QRS detection, HRV analysis. Realisation of therapeutic is designed for applications in Matlab.

Objective: Restorative sleep is associated with increased autonomous parasympathetic nervous system activity that might be improved by heart rate variability-biofeedback (HRV-BF) training. Hence the aim of this study was to investigate the effect of a four-week mobile HRV-BF intervention on the sleep quality and HRV of healthy adults. - Methods: In a prospective study, 26 healthy participants (11 females; mean age: 26.04 ± 4.52 years; mean body mass index: 23.76 ± 3.91 kg/m²) performed mobile HRV-BF training with 0.1 Hz breathing over four weeks, while sleep quality, actigraphy and HRV were measured before and after the intervention. - Results: Mobile HRV-BF training with 0.1 Hz breathing improved the subjective sleep quality in healthy adults [t(24) = 4.9127, p ≤ 0.001, d = 0.99] as measured by the Pittsburgh Sleep Quality Index. In addition, mobile HRV-BF training with 0.1 Hz breathing was associated with an increase in the time and frequency domain parameters SDNN, Total Power and LF after four weeks of intervention. No effect was found on actigraphy metrics. - Conclusions: Mobile HRV-BF intervention with 0.1 Hz breathing increased the reported subjective sleep quality and may enhance the vagal activity in healthy young adults. HRV-BF training emerges as a promising tool for improving sleep quality and sleep-related symptom severity by means of normalizing an impaired autonomic imbalance during sleep.

Au cours des années 1980, il y a été prouvé que l’étude de la variabilité de la fréquence cardiaque (VFC) permet d’estimer de façon non invasive l’activité du système nerveux autonome. Plus spécifiquement, de nombreux travaux démontrent que des enregistrements réguliers de la VFC peuvent rendre compte de la capacité d’adaptation d’un athlète à l’entraînement mais également de son état de fatigue. Bien que plusieurs auteurs suggèrent d’utiliser cet outil directement sur le terrain, il semblerait que l’absence de méthodologie commune et unifiée rende parfois difficile l’interprétation des résultats. Par conséquent, les travaux de recherche présentés au sein de ce manuscrit suivent avant tout une orientation méthodologique avec, néanmoins, une finalité pratique. Une première étude s’intéresse au ratio Basses fréquences/hautes fréquences (LF/HF) qui est communément utilisé comme marqueur de la fatigue. Nos résultats démontrent que chez les athlètes, ce ratio est avant tout modulé par la fréquence de respiration du sujet et que, contrairement à ce qui est couramment admis, une valeur supérieure à quatre ne traduit pas forcément un état de surentraînement. La seconde étude compare l’évolution quotidienne des différents marqueurs de VFC pendant 21 jours de suivi d’athlètes dans deux situations différentes : un enregistrement réalisé en respiration libre et un autre en respiration contrôlée. Nous avons constaté que les marqueurs RMSSD et SD1 suivent exactement les mêmes tendances quel que soit la méthode de respiration. A l’inverse, nos résultats démontrent une nouvelle fois que les indices fréquentiels sont avant tout modulés par la fréquence de respiration de l’individu. La troisième étude s’intéresse à une nouvelle méthode d’évaluation de la charge d’entraînement à l’aide de la VFC. Basée sur trois enregistrements qui intègrent à la fois les perturbations homéostatiques générées par la séance et la vitesse de réactivation parasympathique, la formule proposée permet de quantifier objectivement la charge d’entraînement dans des conditions de terrain. Les fortes interactions qui existent entre la VFC et l’entraînement nous encouragent à poursuivre notre démarche d’investigation pour utiliser cet outil dans le but d’individualiser et d’optimiser la planification d’entraînement des athlètes / During the 1980s, it was demonstrated that studying heart rate variability (HRV) makes it possible to estimate the activity of the autonomic nervous system noninvasively. More specifically, many works showed that regular recording of HRV can be used to monitor an athlete’s capacity to adapt to training and their fatigue. Although several authors have suggested using this tool directly in the field, it appears that the lack of a common and uniform methodology sometimes makes it difficult to interpret results. Therefore the research presented in this manuscript follows a methodological tendency with, nonetheless, a practical objective. The first study focuses on the Low Frequency/High Frequency (LF/HF) ratio commonly used as a fatigue indicator. Our results show that in athletes, this ratio is above all modulated by the subject’s respiratory rate and that, contrary to what is currently accepted, a value higher than four does not necessarily express a state of overtraining. The second study compares the daily evolution of different HRV markers over 21 days monitoring of athletes in two different situations: recording of spontaneous breathing and of controlled respiration. We observed that RMSSD and SD1 markers follow precisely the same trends whatever the breathing method. Conversely, our results show once again that rate indexes are above all modulated by an individual’s breathing frequency. The third study focuses on a new HRV-based method for evaluating training load. Based on three recordings that include both the homeostatic disturbances generated by the session and the speed of parasympathetic reactivation, the method proposed permits objectively quantifying training load under field conditions. The strong interactions existing between HRV and training encourage us to continue our investigative approach and use this tool to individualize and optimize athletes’ training programs

Les systèmes de génétique inverse permettent de manipuler les génomes viraux et se sont révélés essentiels pour étudier les virus à ARN. Récemment, une méthode basée sur la PCR, la méthode ISA (Infectious Subgenomic Amplicons), a été développée. La première partie de cette thèse se concentre sur la simplification de la méthode ISA. La principale contrainte d'ISA est l'exigence de produire des fragments génomiques modifiés qui nécessite un promoteur de transcription à l’extrémité 5’ du premier fragment et un ribozyme du virus de l'hépatite delta, suivi du signal de polyadénylation du virus simien 40 (HDR / SV40pA) à l’extrémité 3’ du dernier fragment. Ici, nous proposons une nouvelle méthode simplifiée "Haiku", dans laquelle sont fournis ces deux séquences en tant qu'amplicons séparés. Cette technique améliorée a été appliquée avec succès à une large gamme de virus dans des cellules de moustiques et de mammifères. La deuxième partie de cette thèse est axée sur la caractérisation de la population virale issue de divers systèmes de génétique inverse en utilisant le HRV-B14 comme modèle.Nos résultats montrent que le choix de la méthode a influencé la diversité génétique des populations virales mais quelle que soit la méthode utilisée, la fitness réplicative était similaire. En outre, nos données ont révélé que le poly(A)25 est la longueur optimale pour récupérer le HRV-B14 avec une efficacité élevée. La dernière partie du présent travail a examiné le potentiel de la méthode «ISA» pour conserver le spectre mutant présent dans l'échantillon viral d'origine. Nous avons montré que cette méthode récapitule au moins partiellement les quasi-espèces de la population virale native. / Reverse genetics systems allow manipulating viral genomes and have proved to be essential for studying RNA viruses. Recently, a PCR-based method, named ISA (Infectious Subgenomic Amplicons), was developed to facilitate the study of single-stranded positive-sense RNA viruses. The first part of the present work focused on simplifying the ISA method. The main constraint of the canonic protocol of the ISA method is the requirement to produce modified genomic fragments encompassing the transcription promoter and the terminator. Here, we propose the ultimately simplified "Haiku" design in which the promoter and the terminator are provided as additional separate DNA amplicons. This improved procedure was successfully applied to the rescue of a wide range of viruses in mosquito and mammalian cells. The second part of this work assessed the viral population issued from different reverse genetics systems. Using HRV B-14 as a model, we compared the genetic diversity and the replicative fitness of viruses generated using the most commonly used reverse genetics methods. Our results showed that the choice of the method influenced the genetic diversity of viral populations but whatever the method used, the replicative fitness was similar. In addition, Our data revealed that poly(A)25 is the optimal length to recover HRV-B14 with high efficiency and could be used to recover polyadenylated RNA viruses other than HRV-B14. The last part of the present work investigated the potential of the “ISA” method to conserve the mutant spectrum present in the original viral sample. We have showed that this method recapitulate at least partially the quasispecies of the native viral population.

Temperature has been known to be an important factor for in vitro studies where human cell cultures are infected with HRV (human Rhinovirus). The mechanisms behind the temperature effect on the struggle between virulence and cellular defense, are still largely unknown and may be a crucial part in finding a treatment to the common cold. In this study we focused on a few cellular key elements in this struggle and observed behavior changes in regards to the pre-infection growth temperature and the temperature during the viral infection. Past studies have focused mainly on the temperature post inoculation, but here we also wanted to correlate virulence to the growth temperatures preceding the viral infection. We found that the growth temperature of the cell did indeed affect its response to the HRV. If the cells had been growing in an optimal body temperature of 37°C before getting virally infected at 33°C, the viability of the cells did decrease in comparison to cells that had been growing in 33°C from before the viral infection. We could also observe a significant temperature dependence regarding IL-8 release upon HRV inoculation. HRV strive to block induction of inflammatory cytokines such as interferons and IL-1. It may be that impaired IL-8 release at lower temperatures will prevent important danger signals alerting the immune system when cytokine signaling is otherwise hampered by viral intervention.

This body of work is the culmination of a two year investigation into the role of electronically enhanced apparel and artefacts in providing empathetic linkage between people who do not share physical space. The research draws from the diverse fields of philosophy, communications theory, neuropsychology, presence technologies and technologically advanced textiles, and proposes that a nexus of these disciplines may provide significant opportunities for enhancing the user interactivity of garments and artefacts. Remote emotional connection is investigated through the creation of sensor embedded garments and artefacts that have been developed in collaboration with a fashion designer and an electronics engineer. The prototypes encourage remote empathetic connection through the real-time transference of heartbeat. The exegesis is structured into five chapters which consider remote presence, flexible consciousness, the architecture of empathy, plasticity in sense perception and the development of prototypes. The project chapter focuses in the development of and testing of a rnage of garments and artefacts thatt conduct presence information between remotely located people. The garments sense, process, transmit and receive the heartbeat signal (ECG). They are enabled with ECG sensors, signal processing equipment, small vibration motors and radio transceivers which allow users to 'feel' the heartbeat of a remote friend/lover/relative as vibration through their garment. The prototypes aim to enrich the remote communications experience through reintroducing an embodied, tactile dimension that is present in face-to-face communication. A range of user testing trials are discussed in the thesis which have been undertaken to assess the impact of the garments at a conscious and a non-conscious level. Conscious experiences were gauged through qualitative testing by way of interviews and unsolicited written reactions. Non-conscious physiological ractions were assessed by recording ECG throughout user-testing periods. This data has been processed by using HRV (heart rate variability) analysis software, running on MatLab.

<p><font face="Times New Roman" size="3"><font face="Times New Roman" size="3"> <p align="left">This thesis is a discourse analysis of five testimonies from South Africa&rsquo / s Truth and Reconciliation Commission. The aim of the analysis is to explore the ways in which the testifiers perform their identities, construe their experiences of life under apartheid, and position themselves and their audiences in relation to these experiences. The shaping role of context &ndash / both local and historical &ndash / is also considered.</p> </font></font></p>

This thesis aims to increase the knowledge on people with symptoms attributed to electromagnetic fields (EMF) by investigating the effects of EMF exposure and by additional description of the heterogeneous group of people reporting EMF-related symptoms. The effect of mobile phone (MP)-like radio frequency (RF) fields on symptoms, autonomic nervous system (ANS) parameters, short-term memory, and reaction time in persons with MP-related symptoms (MP participants) was investigated in a provocation study. A second provocation study investigated the effect of similar exposure on serum concentration of biomarkers in persons with atopic dermatitis. No effect of exposure was detected in either study. MP participants displayed changes in heart rate variability (HRV) during cognitive tests, but not during rest. This contrasts with earlier findings, participants with symptoms attributed to EMF sources in general (EHS participants) displayed an elevated sympathetic nervous system activity both during cognitive tests and during rest. Proposed differences between subgroups of persons with EMF-related symptoms with respect to symptoms, personality traits and stress were investigated in a questionnaire study. MP participants reported primarily symptoms from the head; EHS participants reported symptoms from many organ systems. Furthermore, EHS participants reported higher levels of anxiety, depression, stress, and exhaustion when compared with a reference group. MP participants reported higher levels of anxiety and exhaustion only. In a pilot study, 24-hour and short-term HRV were investigated in EHS participants, to examine whether the previously observed sympathovagal imbalance would still be present. There was a tendency toward increased parasympathetic activity compared with earlier recordings, and a reduction of symptoms. Twenty-four hour and short-term recordings were fairly similar for each participant; however, there were large between-subject differences. The results do not support the hypothesis of effects of MP-like RF exposure on symptoms, ANS activity, CFFT, cognitive function, or biomarkers. However, they do support the hypothesis that persons with different symptom attribution (MP and EHS) may differ also in ANS activity and psychological aspects.

Diagnosis of stress is important because it can cause many diseases e.g., heart disease, headache, migraine, sleep problems, irritability etc. Diagnosis of stress in patients often involves acquisition of biological signals for example heart rate, finger temperature, electrocardiogram (ECG), electromyography signal (EMG), skin conductance signal (SC) etc. followed up by a careful analysis of the acquired signals. The accuracy is totally dependent on the experience of an expert. Again the number of such experts is also very limited. Heart rate is considered as an important parameter in determining stress. It reflects status of the autonomic nervous system (ANS) and thus is very effective in monitoring any imbalance in patient’s stress level. Therefore, a computer-aided system is useful to determine stress level based on various features that can be extracted from a patient’s heart rate signals. Stress diagnosis using biomedical signals is difficult and since the biomedical signals are too complex to generate any rule an experienced person or expert is needed to determine stress levels. Also, it is not feasible to use all the features that are available or possible to extract from the signal. So, relevant features should be chosen from the extracted features that are capable to diagnose stress. Again, ECG signal is frequently contaminated by outliers produced by the loose conduction of the electrode due to sneezing, itching etcetera that hampers the value of the features. A Case-Based Reasoning (CBR) System is helpful when it is really hard to formulate rule and the knowledge on the domain is also weak. A CBR system is developed to evaluate how closely it can diagnose stress levels compare to an expert. A study is done to find out mostly used features to reduce the number of features used in the system and in case library. A software prototype is developed that can collect ECG signal from a patient through ECG sensor and calculate Inter Beat Interval (IBI) signal and features from it. Instead of doing manual visual inspection a new way to remove outliers from the IBI signal is also proposed and implemented here. The case base has been initiated with 22 reference cases classified by an expert. A performance analysis has been done and the result considering how close the system can perform compare to the expert is presented. On the basis of the evaluations an accuracy of 86% is obtained compare to an expert. However, the correctly classified case for stressed group (Sensitivity) was 57% and it is quite important to increase as it is related to the safety issue of health. The reasons of relatively lower sensitivity and possible ways to improve it are also investigated and explained.