Les perceptions sensorielles et hédoniques résultent de processus complexes d’intégration, qui ne sont pas seulement rationnels, mais aussi fondés sur des sentiments, des émotions et des souvenirs. Afin d'appréhender au mieux le comportement du consommateur, il est devenu indispensable de mesurer les émotions afin de comprendre leur rôle fondamental dans la prise de décision. En science du consommateur, les émotions sont principalement mesurées par questionnaire. Malheureusement, cette mesure reste subjective et limitée car les sujets ont du mal à exprimer précisément leurs émotions par des mots. L’objectif de cette thèse était de contribuer à la compréhension de l’influence des émotions sur les perceptions hédoniques en développant un outil de mesure objectif fondé sur la pupillométrie. Ce travail de thèse a permis le développement d’une méthodologie adaptée à la situation de dégustation. Il a également permis de mettre en évidence que toute stimulation gustative même dépourvue d’émotion entraînait une dilatation pupillaire, mettant l’accent sur l’intérêt de comparer des stimuli similaires ou d’avoir une situation contrôle. Ensuite, différentes expérimentations ont permis de montrer que les différents éléments du contexte alimentaire avaient des pouvoirs émotionnels différents. Notamment les odeurs comme celles de boissons alcoolisées sont de fort vecteurs émotionnels tout comme les stimuli auditifs lorsqu’ils affectent directement le sujet. Enfin, la mesure en parallèle de l’appréciation hédonique nous a permis de montrer que la préférence n’est pas l’unique déterminant des émotions et de confirmer que les émotions peuvent impacter l’appréciation hédonique. / Sensory and hedonic perceptions are the result of complex integration processes that are not only rational but that are also based on sentiments, emotions and memories. In order to better understand consumer behavior, it has become essential to measure emotions in order to understand their fundamental role in decision-making. In the field of consumer science, emotions are generally measured using questionnaires. Unfortunately, this measurement remains subjective and limited because it is difficult for subjects to precisely express their emotions through words. The aim of this thesis was to contribute to the understanding of the influence of emotions on hedonic perceptions by developing an objective measurement tool based on pupillometry. This PhD research made it possible to develop a methodology adapted to tasting situations and to show that all gustative stimulation, even that lacking emotion, leads to pupillary dilation, emphasizing the interest in comparing similar stimuli or having a control situation. Finally, different experiments revealed that the different elements within the food context had different emotional powers. In particular, smells, like those of alcoholic beverages, are strong emotional vectors, just like auditory stimuli when they directly affect the subject. Finally, by measuring the hedonic assessment at the same time, we were able to show that preference is not just determined by emotions and to confirm that emotions can have an impact on the hedonic assessment.

No description available.

No description available.

No description available.

Energy harvesting using ferrofluid in OHP. Characterization of as-synthesized (bare) and surface-modified ferrofluid samples was performed using Fourier transform infrared spectroscopy, dynamic light scattering, X-ray powder diffraction, transmission electron microscopy, and atomic force microscopy. These ferrofluids were tested in a novel oscillating heat pipe set-up was utilized to harvest electricity, demonstrating the concept of ferrofluidic induction. Cobalterrite nanoparticles surface-modified with citric acid demonstrated good magnetic strengths and generated voltages close to those of the as-synthesized ferrofluids while maintaining dispersion. Surface modification of ferrous nanoparticles with SRP. Thermo responsive polymer poly(N-isopropylacrylamide) was successfully grown from the surface of cobalt-zinc ferrite nanoparticles. A dual responsive block copolymer, pH and thermo responsive comprised of poly(itaconic) acid and poly(N-isopropylacrylamide) was successfully polymerized from the surface of ferrous oxide nanoparticles. These composite having magnetic properties along with stimulus can be used in applications such as controlled drug delivery and similar biomedical applications.

Se déplacer selon un but déterminé est une activité courante de la vie quotidienne. Des capacités cognitives variées sont associées aux déplacements, comme la navigation, la mémoire ou encore l’orientation spatiale. De nombreux patients cérébro-lésés ou atteints par une maladie neuro-dégénérative présentent des difficultés topographiques qui retentissent sur leur autonomie en vie quotidienne. Les outils de réalité virtuelle permettent d’évaluer la navigation et la mémoire spatiale à grande échelle, avec une bonne corrélation entre cette évaluation et celle qui serait réalisée dans un environnement réel. La réalité virtuelle permet également d’ajouter des stimuli à la tâche proposée. Ces stimuli additionnels peuvent être contextuels, c’est à dire reliés à la tâche à réaliser dans l’environnement virtuel, ou noncontextuels, soit sans lien avec la tâche à accomplir. Ce travail de thèse s’est attaché à évaluer l’impact de stimuli auditifs et visuels sur la navigation et la mémoire spatiale de patients cérébro-lésés ou présentant une maladie neuro-dégénérative, dans des expériences de réalité virtuelle. Les deux premiers volets de cette thèse ont étudié l’effet de stimuli auditifs contextuels ou non-contextuels lors d’une tâche de courses au sein du supermarché virtuel VAP-S. Le premier volet a montré que des stimuli auditifs contextuels de type effet sonar et énoncé du nom du produit facilitaient la navigation spatiale de patients cérébro-lésés impliqués dans cette tâche de courses. Le second volet a mis en évidence que des sons non-contextuels avec une importante saillance cognitive ou perceptuelle péjoraient la performance de navigation de patients ayant présenté un accident vasculaire cérébral. Les deux volets suivants de cette thèse ont étudié l’effet d’indiçages visuels ou auditifs dans une tâche de navigation spatialedans un quartier virtuel. Ainsi, le troisième volet de la thèse a démontré que des indices visuels comme des flèches directionnelles ou des points de repère sursignifiés facilitaient la navigation spatiale et certains aspects de mémoire spatiale de patients avec des troubles cognitifs légers (MCI) ou présentant une Maladie d’Alzheimer. Enfin, le quatrième volet a mis en évidence qu’un indiçage auditif par des bips indiquant la direction à chaque intersection améliorait la navigation spatiale de patients cérébro-lésés droits présentant une héminégligence visuelle et auditive controlatérale. Ces résultats suggèrent que des stimuli auditifs et visuels pourraient être utilisés lors de prises en charge rééducatives et réadaptatives de patients présentant des difficultés topographiques, ainsi qu’en vie quotidienne par le biais de la réalité augmentée afin de faciliter leurs déplacements. L’impact des stimuli chez les sujets sains et chez les cérébrolésés est différent et justifie une analyse spécifique de processus probablement distincts impliqués lors des déficits cognitifs. / Navigating in a familiar or unfamiliar environment is a frequent challenge for human beings. Many patients with brain injury suffer from topographical difficulties, which influences their autonomy in daily life. Virtual Reality Tools enable the evaluation of largescale spatial navigation and spatial memory, resembling a real environment. Virtual reality also permits to add stimuli to the software. These stimuli can be contextual, that is to say linked to the task that participants have to accomplish in the Virtual Environment, or non-contextual, i.e. with no link with the require task. This thesis investigates whether visual or auditory stimuli influence spatial navigation and memory in Virtual Environments of patients with brain injury or with a neurodegenerative disease. The first part of the thesis showed contextual auditory stimuli type a sonar effect and the names of products of the shopping list improved spatial navigation of brain-injured patients during a shopping task in the virtual supermarket VAP-S. The second part of this thesis highlighted that non-contextual auditory stimuli with a high perceptual or cognitive salience decreased spatial navigation performance of brain-injured patients during a shopping task in the VAP-S. The third part of this thesis showed that visual cues like directional arrows and salient landmarks improved spatial navigation and some aspects of spatial memory of patients with Alzheimer’s disease or Mild Cognitive Impairments during a navigation task in a virtual district. The last part of this thesis demonstrated that auditory cues, i.e. beeping sounds indicating the directions, increased spatial navigation in a virtual district of patients who have had a stroke with contra-lesional visual and auditory neglect. These results suggest that some visual and auditory stimuli could be helpful for spatial navigation and memory tasks in patients with brain injury of neuro-degenerative disease. It further offers new research avenues for neuro-rehabilitation, such as the use of augmented reality in real-life settings to support the navigational capabilities of these patients.

Konsumenter ställs inför en ständigt ökande mängd information som påverkar deras beslutsprocess vid en köpsituation. Delar av denna problematik går under benämningen konsumentförvirring och delbegreppen homogenitet, överflöd och tvetydighet. Denna kvalitativa studie syftade till att undersöka lågengagemangsprodukter i livsmedelsbutiker och hur stimuli i form av produktattribut och butiksstimuli kan påverka konsumenters utformning av strategier för att minska förvirring. Undersökningen baserades på samtal utifrån tre fokusgrupper där resultaten visar att det inte kan fastställas något entydigt svar på denna fråga. Detta beror på att olika grader av engagemang och skiftande preferenser identifierades beroende på konsumenttyp och vilket produktsortiment som behandlades.

The advent of highly sophisticated drugs designed to interfere with specific cellular functions has created the demand for “intelligent” carriers that can efficiently deliver therapeutic agents in response to a pathophysiogical condition. Nanoscale intelligent systems can maximize the efficacy of therapeutic treatments in numerous ways because they have the ability to rapidly detect and response to disease states directly at the site and sparing physiologically healthy cells and tissues, thereby improving a patient’s quality of life. Nanoparticle fabrication has primarily relied on emulsions, self-assembly and micelles based methods which inherently generate polydisperse spherical particles with little control over particle geometry. Despite significant progress in such drug delivery systems, critical limitations remain in synthesizing nanocarriers with highly controllable architecture (size, shape or aspect ratio) that can, at the same time, impart response-sensitive release mechanisms. These parameters are essential for controlling the in-vivo transport, bio-distribution, and drug release mechanisms. The objective of my dissertation is to employ the nanofabrication technique Step and Flash Imprint Lithography (S-FIL) to synthesize stimuli-responsive nanocarriers of precise architectures and composition. Applying S-FIL technology, fabrication of nanocarriers of a variety of shapes and sizes (down to 36nm length scale) that are also environmentally responsive by incorporating enzymatically-degradable peptides into the nanocarrier hydrogel matrix, to provide triggered release of encapsulated therapeutic agents in response to specific pathophysiological conditions, has been accomplished. Besides disease-responsive release, the two key properties of an effective nanocarrier are (a) efficient targeting to specific tissues and cells and (b) avoiding rapid clearance and remaining in circulation in the blood stream for a significant amount of time to increase particle uptake in target tissues. These two properties are expected to be dependent on the shape and size of the carriers. Using various shape and size S-FIL fabricated nanoparticles, the effects of particle geometry on intracellular uptake has also been evaluated. In this dissertation, I will present the extensive work that has been done in the fabrication and optimization of the S-FIL nanocarriers, evaluation of the nanocarrier’s in vitro properties, and evaluation of the effects of nanocarrier geometry on intracellular uptake. / text

No description available.

The objective of this study was to determine if eye and head based psychophysiological cues can be used to maintain screener vigilance levels during long duration tasks. In two parts, this study first explored which cues are predictive of vigilance levels. The second part of the study developed a vigilance feedback system using the cues established in part one and compared the results of subjects using the feedback system with those subjects having received no feedback or those who received random feedback.In part one, 48 participants reviewed 600 simulated x-rays to determine if any hazardous items (guns or knives) were present. Individual vigilance levels were determined by scoring the number of correct detections during eight 5-minute periods (total study length = 40 minutes). Using an eye-tracking machine, four concurrent eye and head activity measures (blinks, saccades, pupil diameter, and head position) were used to model changes in vigilance level throughout a simulated baggage screening task. At the end of the study, changes in blink and saccade rates proved to be significant predictors of an individual's ability to detect the presence of these hazardous items among other non-significant baggage items.Part two required 126 participants equally distributed across three conditions to repeat the same screening task. For one condition the monitoring system, instead of passively recording the individual's cues, provided near real-time feedback of vigilance levels to a condition. Participants in other conditions received random feedback on their vigilance levels while a third group received no feedback. At the conclusion of the study the subjects who received the real-time feedback performed significantly better than those who received no feedback. However, they did not perform better than the subjects who received random feedback. Perhaps more significantly, the subjects who received random feedback, while performing better than the no feedback group, also experienced a significantly higher number of false detects.The results of this study indicate a vigilance feedback system based upon subject psychophysiological cues may be an effective method to maintain attention levels during long duration vigilance tasks while preventing a corresponding increase in error detection rates.