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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
91

Métrologie sensorielle olfactive et apprentissage olfactif appliqués à l’œnologie / Metrology and olfactory learning applied to oenology

Tempère, Sophie 06 December 2010 (has links)
L’agrément d’un vin dépend du jugement de ses qualités organoleptiques par un jury de professionnels. Les performances olfactives et gustatives nécessaires des dégustateurs y jouent un rôle déterminant. Pourtant jusqu’ici, ces aptitudes sensorielles fondamentales n'étaient pas directement prises en compte par les professionnels. Même si l’on peut donner une définition de l'expert, en préciser les capacités nécessaires, de multiples études ont mis en relief l’hétérogénéité des appréciations individuelles de dégustation et le manque de consensus forts. La littérature illustre les différences d’expertises entre professionnels et novices, mais aucune étude ne s’intéresse à l’amplitude des différences sensorielles interindividuelles chez les experts.Nos recherches nous ont conduit à caractériser les capacités olfactives de la population des professionnels du vin et à mesurer leur influence sur l’appréciation d’un vin. Nos mesures ont montré la variété interindividuelle des capacités perceptives, des appréciations hédoniques et des capacités cognitives recrutées par le traitement de l’information olfactive chez les professionnels du vin. Nos expériences ont suggéré que ces différences interindividuelles, relatives notamment à la sensibilité et l’appréciation hédonique, influencent la perception et le jugement d’un même vin par les experts. Cependant les résultats confirment aussi la possible influence de la dimension cognitive liée au vécu du sujet sur la perception olfactive plus ou moins complexe et l’apprentissage olfactif. Finalement, ce travail permet de déterminer des besoins en formation. Nous proposons en conséquence des outils pratiques d’évaluation des capacités sensorielles et des pédagogies d’entraînement adaptées. C'est l'occasion de souligner la pertinence de certains facteurs cognitifs dans l’amélioration des performances olfactives, tels que ceux impliquant l’attention ou l'imagerie mentale olfactives. / The quality of a wine is measured primarily by experts who evaluate its organoleptic features. Their olfactory and gustatory capacities are decisive, but these experts do not appreciate their own sensory abilities. Moreover, although we can give a clear definition of the expertise, several studies have shown that professionals are often confronted with disparities in their wine assessment. Several studies have also shown the differences between experts and novices, but no attention was paid to the diversity of the chemosensory abilities of the experts.At the Oenology Faculty in Bordeaux, with voluntary participation of the professionals, we characterized the olfactory performances of wine professionals and measured their impact on the wine assessment.The results showed significant inter-individual variation in olfactory sensitivities, hedonic ratings and cognitive abilities among the wine professionals. Further, our experiments have suggested that these inter-individual differences, especially concerning the sensitivity and the hedonic appreciation, influence perceptions and judgments of a same wine by the experts. However, the results confirm the possible influence of the cognitive dimensions related to the experience of the subject on their perception and their olfactory training. Finally, this work identifies training needs. We therefore propose and test practical tools for assessment of sensory performances and appropriate sensorial training. This has been an opportunity to highlight the potential role of attention or olfactory mental imagery in the improvement of the olfactory performance.
92

Maturation and synapse formation of olfactory sensory neurons after injury

Yarid, Colin R, Chapman, Rudy T, Rodriguez-Gil, Diego J. 12 April 2019 (has links)
The olfactory system is a great model to ask questions related to neuronal regeneration, axon guidance and synapse formation. Processing of smell begins in the olfactory epithelium where sensory neurons are present and the olfactory bulb is the first stop in processing odor information in the central nervous system. While the olfactory bulb has neurons that regenerate as well, we are interested in the regeneration that occurs in the olfactory epithelium after being injured because it possesses a source of neural stem cells – something unique to the rest of the body. Earlier studies have proven that the introduction of methimazole will effectively damage the olfactory sensory neurons while keeping the neural stem cells intact. By using a fate mapping technique involving Cre-ERT2 mice, we are able to track the regeneration of these sensory neurons after a methimazole induced injury. Using immunohistochemistry in combination with ImageJ software analysis, we are able to pinpoint the colocalization of markers of new olfactory sensory neurons (green fluorescent protein (GFP)) with markers of neuron maturation (olfactory marker protein (OMP)) and synapse formation (tyrosine hydroxylase (TH) and synaptophysin). Analysis of maturation was done in the olfactory epithelium by studying the colocalization of the protein OMP and GFP. Data shows that after regeneration, neurons coexpress both markers 11 days after lesion. In the olfactory bulb, we characterized the recovery of synaptic markers TH and synaptophysin after axons reached the olfactory bulb, where olfactory sensory neuron axons make synaptic contacts with dendrites of projection neurons. Overall, these data are the first one to establish a timeline for axonal regeneration and synapse formation after injury in the olfactory system.
93

TEACHING OLFACTORY RELATIONS TO ADOLESCENTS WITH AUTISM

Blondin, Sandra Nicole 01 May 2020 (has links)
The current study utilized a multiple baseline design to teach olfactory discrimination skills to adolescent participants with autism spectrum disorders. Relational abilities among smells and causal relations were initially probed and an intervention was implemented via training and reversal testing probes using frames of distinction between stimulus depicting clean clothing (A) and worn clothing (B), causal framing to relate those odors with specific actions stimulus depicting clean clothing (A) with wearing or hanging the clothing (C) and stimulus depicting worn clothing (B) and placing the clothing in the laundry or hamper (D). Finally, these skills were tested in an applied setting when comparing clothing items that may or may not need to be laundered through the demonstrate of transformation of stimulus function in a novel setting by testing relations between clean clothing (Y) and wearing or hanging the clothing (C) and previously worn clothing( Z) and putting them in the laundry or hamper (D). The intervention was effective at establishing these relational responses for all 4 participants throughout each phase leading to the application of these responses in an applied setting with 80%-100%. Limitations and future application are discussed involving the use of cross modal stimuli in when teaching relations and broader implications of the science.
94

Studies on the searching behavior modified by olfactory conditioning in the German cockroach, Blattella germanica(L.) / 匂い学習で修飾されるチャバネゴキブリの探索行動に関する研究

Liu, Jiali 24 September 2013 (has links)
京都大学 / 0048 / 新制・課程博士 / 博士(農学) / 甲第17903号 / 農博第2026号 / 新制||農||1018(附属図書館) / 学位論文||H25||N4799(農学部図書室) / 30723 / 京都大学大学院農学研究科応用生物科学専攻 / (主査)教授 佐久間 正幸, 教授 松浦 健二, 教授 天野 洋 / 学位規則第4条第1項該当 / Doctor of Agricultural Science / Kyoto University / DGAM
95

Genes, Transposable Elements, and Small RNAs: Studying the Evolution of Diverse Genomic Components

Vandewege, Michael W 07 May 2016 (has links)
The evolution of genes and genomes has attracted great interest. The research presented here is an examination of genomes at three distinct levels, protein evolution, gene family evolution, and TE content regulation. First at a genetic level, I conducted an analysis of the salivary androgen-binding proteins (ABPs). I focused on comparing patterns of molecular evolution between the Abpa gene expressed in the submaxillary glands of species of New World and Old World muroids and found that in both sets of rodents, the Abpa gene expressed in the submaxillary glands appear to be evolving under sexual selection, suggesting ABP might play a similar biological role in both systems. Thus, ABP could be involved with mate recognition and species isolation in New World as well as Old World muroids. Second I examined the largest gene family in vertebrate olfactory receptors (ORs) among birds and reptiles. I found that the number of intact OR genes in sauropsid genomes analyzed ranged over an order of magnitude, from 108 in the lizard to over 1000 in turtles. My results suggest that different sauropsid lineages have highly divergent OR repertoire compositions. These differences suggest that varying rates of gene birth and death, together with selection related to diverse natural histories, have shaped the unique OR repertoires observed across sauropsid lineages. Lastly, I studied the interactions between transposable elements (TEs) and PIWI-interacting RNAs (piRNAs) among laurasiatherian mammals. piRNAs are predominantly expressed in germlines and reduce TE expression and risks associated with their mobilization. I found that within TE types, families that are the most highly transcribed appear to elicit the strongest ping-pong response. This was most evident among LINEs, but the relationships between expression and PPE was more complex among SINEs. I also found that the abundance of insertions within piRNAs clusters strongly correlated with genome insertions and there was little evidence to suggest that piRNA clusters regulated TE silencing. In summary, the piRNA response is efficient at protecting the genome against TE mobility, particularly LINEs, and can have an evolutionary impact on the TE composition of a genome.
96

Ultrastructural Effects of Chemical Modification on Olfactory Receptors

Thompson, Rebecca M. (Rebecca Mae) 08 1900 (has links)
The ultrastructural effects of chemical modification on olfactory receptors were investigated with scanning electron microscopy, transmission electron microscopy and fluorescent microscopy. Mason and Morton (1984) hypothesized that a two-step chemical treatment would covalently modify receptor proteins. Their two-step protocol was modified in an attempt to label olfactory receptor proteins and the ultra structural effects of the original two-step protocol were examined.
97

Association Between Unirhinal Olfactory Processing And Self-reported Empathy In Schizophrenia

Kamath, Vidyulata 01 January 2009 (has links)
Empathy represents one multifaceted component of social cognition that is thought to be significantly impaired in individuals with schizophrenia. Psychophysical tasks of smell identification and hedonic processing of pleasant, neutral, and unpleasant odors share common neural networks involved in empathy. Therefore, we investigated the relationship between odor identification, odor ratings, and self-reported empathy in 25 outpatients with schizophrenia and 25 nonpsychiatric individuals. Group differences on empathy scores and unirhinal smell identification performance (with hedonic and intensity ratings) were examined, along with the relationships between smell identification scores, self-reported empathy, and schizophrenia symptomatology. The preliminary findings suggest that individuals with schizophrenia display significant differences from controls on measures of self-reported empathy, odor identification, and hedonic ratings of odors. Deficits in self-reported global and affective empathy were influenced by group and sex, whereas cognitive empathy was reduced across all patients in comparison to controls. Patients displayed reduced unirhinal odor identification accuracy for pleasant but not neutral or unpleasant odors in comparison to controls. Central to the overall aim of the current study, a robust positive correlation was observed between left- and right-nostril hedonic ratings for pleasant odors and self-reported global and affective empathy scores across all participants. In patients, we also found a statistical trend between affective empathy and left-nostril identification accuracy across all odors. Collectively, the results lend support to the role of olfactory-limbic brain regions in the hedonic processing of odors and suggest that aberrant performance observed in schizophrenia may be related to abnormalities in the anatomical and physiological substrates that also subserve empathy.
98

Olfactory and Behavioural Regulation of Territorial Aggression in Feral Rats (Rattus norwegicus)

Alberts, Jeffrey R. 10 1900 (has links)
<p> This thesis is primarily concerned with the problem of recognition among feral Norway rats. Wild rats are known to behave amicably in the presence of colony members and act in a stereotyped aggressive manner towards unfamiliar conspecifics in a territorial context. Previous reports suggest that identity is basically olfactory and is organized around colony-specific odors residing in the nesting material or the metabolic excretions of the male members of a colony.</p> <p> The first experiments in this study were attempts to replicate various reports concerning the maleability of clan odors, thereby giving a wild rat the olfactory characteristics of an alien group and, conversely, to alter a resident's odor such that he was no longer identifiable as a member of his original clan. Further experiments examined identifier and regulator functions of behavioural cues on social interaction subsequent to recognition. The interactions of unfamiliar rats on a mutually common terrain was studied, and compared with that of familiar rats paired on an uncommon territory. The final experiment investigated the functional nature of olfactory stimulation in these situations and compared the reactions of anosmic residents towards familiar and unfamiliar conspecifics.</p> <p> These experiments indicate that recognition is indeed an olfactory process but that identity is highly resistent to alteration. The identifier substance does not appear to be contained in either the nesting matter nor in a colony's urine or feces. Bond of familiarity are not specific to a common terrain and in most cases behavioural cues appear to control the onset and termination of fight behaviour following the olfactory identification. Studies of anosmic residents indicate that novel odors elicit aggressive tendencies while familiar odors are not inhibitors of aggression. The results suggest the presence of a specific male pheromone that is essential for the arousal of aggression while the topography of interaction is regulated largely by the reciprocal behaviours of the animals.</p> / Thesis / Master of Arts (MA)
99

CLUSTERING OF CYCLIC-NUCLEOTIDE-GATED CHANNELS IN OLFACTORY CILIA

FLANNERY, RICHARD JOHN 06 April 2006 (has links)
No description available.
100

Investigating Zinc Toxicity In Olfactory Neurons: In Silico, In Vitro, And In Vivo Studies

Hsieh, Heidi January 2015 (has links)
No description available.

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