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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.
31

Luktfunktion hos vuxna med diagnos inom Autismspektrumet

Addo, Rebecka January 2014 (has links)
Tidigare forskning visar att individer med en diagnos inom autismspektrumet (ASD) upplever en större sinneskänslighet vad gäller hörsel, syn och känsel men få studier har undersökt lukt känsligheten. Syftet med föreliggande studie är att få en djupare förståelse för luktfunktioner hos vuxna med ASD.16 deltagare med ASD (14 kontroller) testades i luktkänslighet, fri- och stödd luktidentifiering. Samtliga deltagare självskattade även den upplevda luktkänslighet samt genomgick ett screeningtest för autism, The adult spectrum quotient, AQ. Lukt känslighet, fri och stödd luktidentifikation skiljde sig inte åt mellan de båda grupperna Självskattning av luktfunktioner korrelerade signifikant positivt med AQ poäng vilket visar att personer med högre grad av ASD också upplevde sig som mer luktkänsliga. Föreliggande resultat påvisade att personer med högre AQ-poäng upplevde att de hade en känsligare luktfunktion. Dock reflekterades denna självskattade känslighet inte i de standardiserade lukttesten där inga signifikanta skillnader mellan ASD och kontroller i luktfunktioner påvisades. / Previous research has shown that individuals with a diagnosis within the autism spectrum (ASD) experience a greater sensory sensitivity, but few studies have investigated the olfaction sensitivity. The aim of the present study is to gain a deeper understanding of the olfactory functions in adults with ASD.16 participants with ASD (14 controls) participated in the study where sniffin sticks were used to evaluate the differences between the groups. All participants answered a questionnaire about perceived olfaction sensitivity and the adult spectrum quotient; AQ. Olfactory discrimination and identification (with and without cue) did not differ between the groups, as for olfaction sensitivity, perceived pleasantness, intensity and edibility. When it came to self-assessed olfactory sensitivity, differences were found. However, this self-rated sensitivity did not appear in the standardized odor tests, where no significant differences between ASD and controls odor features were detected.
32

SKEIN: pick up styx

Turner, Raewyn Mary January 2008 (has links)
The work in progress, Pick Up Styx, investigates re-sensing and extra-sensing of the world. It is an exploration of communications with reference to quantum theory which challenges current sense perceptions, while engaging and exploring the notion of communications as signals. The methodology is a winding, coiling motion between research and creative practice based on the way my grandmother used to wind wool from a skein into a ball. The project investigates the game as a tool to examine the ciphers of perfumes that have been designed for love and happiness since 2001. The project aims to develop aesthetic pleasure in game play beyond the industry focus on games technology. Picking up the sticks and experiencing the perfumes in them is procedural to encountering the War on Terror, and the perfumes that have accompanied its progression over the last 8 years. In a materialist culture where technologies are enabling psycho kinesis, via the transmission of information signals, and where thought can influence matter in a variety of ways, we are training ourselves out of separatist thinking and fixation on the Western scientific paradigm. This project has grown from my curiosity regarding anomalous forms of cognition and paranormal perception, motivated by the need to address current issues of human relationship and environmental concerns.
33

Modulation and Ligand Selectivity of Mammalian Odorant Receptors

Jiang, Yue January 2015 (has links)
<p>In mammals, the perception of smell starts with the activation of odorant receptors (ORs) by volatile molecules in the environment. Mammalian genomes typically encode large numbers of ORs, with approximately 400 intact ORs in human and more than 1000 in mouse. Central to the question of how olfactory stimuli are represented at the peripheral level is defining the ligand selectivity and activity regulation of ORs.</p><p>Processing of chemosensory signals in the brain is dynamically regulated in part by an animal’s physiological state. The Matsunami lab previously reported that type 3 muscarinic acetylcholine receptors (M3-Rs) physically interact with odorant receptors (ORs) to promote odor-induced responses in a heterologous expression system. However, it is not known how M3-Rs affect the ability of olfactory sensory neurons (OSNs) to respond to odors. In chapter 2, I demonstrate that the activation of M3-Rs inhibits the recruitment of β-arrestin-2 to ORs, resulting in a potentiation of odor-induced response in OSNs. These results suggest a role for acetylcholine in modulating olfactory processing at the initial stages of signal transduction in the olfactory system.</p><p>Understanding odor coding requires comprehensive mapping between odorant receptors and corresponding odorants. In chapter 3, I present a high-throughput in vivo method to identify repertoires of odorant receptors activated by odorants, using phosphorylated ribosome immunoprecipitation of mRNA from olfactory epithelium of odor-stimulated mice followed by RNA-Seq. This approach screens endogenously expressed odorant receptors against an odorant in one set of experiments, using awake and freely behaving mice. In combination with validations in a heterologous system, we identify sets of odorant receptors for two odorants, acetophenone and 2,5-dihydro-2,4,5-trimethylthiazoline (TMT), encompassing 69 receptor-odorant pairs. I also identified shared amino acid residues specific to the acetophenone or TMT receptors, and developed a model to predict receptor activation. This study provides a means to understand the combinatorial coding of odors in vivo.</p> / Dissertation
34

Olfactory neurogenesis during tissue maintenance and repair

Dittrich, Katarina 31 May 2018 (has links)
No description available.
35

The Greek sense of smell : olfactory perception and the sociocultural roles of perfume in antiquity

Grant, Grainne Louise January 2014 (has links)
Olfactory perception is as sociocultural a phenomenon as it is a physiological one. Scents of all types and the meanings assigned to them contribute to and shape human cultures, and humans have deliberately manipulated smells to sway the opinions and value judgements of others since, at the very least, the dawn of agriculture. ‘Smellscapes’ define our environments. How we smell what we smell and why we interpret what we smell the way we do are inextricably intertwined, and this was no less true in the Classical world. When we study how people in antiquity examined the sense of smell in general and the corresponding roles of perfume in particular, we see many of the same issues and questions being raised as concern scientists today. Applying modern models to ancient practices can enhance insight into Greek and Roman cultures. This paper will discuss physiological olfactory perception as the authors in the Classical and Hellenistic periods defined and described that, and will examine the primary literature regarding perfume in order to provide a specific example of one way in which we can be initiated into the mysteries of a different and long-gone cultural sensorium through the written word.
36

L’effet de l’exposition aux stimuli olfactifs sur le sentiment de présence en réalité virtuelle

Baus, Oliver January 2016 (has links)
Le sens de l’olfaction joue un rôle important dans la vie de tous les jours. Dans le monde physique (« réel »), les odeurs peuvent affecter l’humain de diverses manières. Bien que les avantages potentiels à intégrer des stimuli olfactifs dans des environnements virtuels (EV) aient été soulignés dans divers articles, ils sont rarement intégrés dans des applications de réalité virtuelle (RV). Les utilisations existantes et potentielles intégrant des stimuli olfactifs en RV incluent des applications cliniques tels le traitement des états de stress post-traumatique et le traitement d’addictions, des applications de formation telles que les réponses aux urgences et la relaxation, ainsi que des applications destinées à la recherche concernant les intégrations multisensorielles. Cependant, très peu d’études empiriques ont examiné les effets d’odeurs sur la qualité de l’expérience en RV. C’était l’objectif de ce projet. De façon plus précise, le but de ce projet était d’évaluer l’effet que peut avoir l’exposition à des odeurs agréable et désagréable sur les sentiments de présence (mesure principale), réalité et réalisme (mesures exploratoires) en RV. Cette relation a été mise à l’épreuve dans le cadre de trois études complémentaires, chacune faisant appel à une condition contrôle (exposition à l’air ambiant) et deux conditions expérimentales (exposition à une odeur agréable de tarte aux pommes/cannelle ou une odeur désagréable d’urine). Alors que les trois études ont suivi le même protocole, la scène visuelle des EVs variait d’une étude à l’autre. Pour l’Étude 1, il n’y avait pas de concordance entre la scène visuelle et les odeurs, pour l’Étude 2, il y avait concordance entre la scène visuelle et l’odeur désagréable et pour l’Étude 3, il y avait concordance entre la scène visuelle et l’odeur agréable. La variation des EVs avait pour visée de vérifier l’effet de l’exposition aux odeurs sur la présence dans différentes conditions de concordance entre la scène visuelle et l’odeur. L’ensemble des résultats révèle que, dans une situation sans concordance entre la scène visuelle et l’odeur, ainsi que dans une situation de concordance entre la scène visuelle et l’odeur désagréable, l’exposition à une odeur désagréable augmente le sentiment de présence de manière statistiquement significative. Lors d’une concordance visuelle avec une odeur désagréable, l’exposition à une odeur désagréable augmentait également la perception de réalité et réalisme de l’EV de manière statistiquement significative. De plus, dans un EV dont la scène visuelle est concordante avec une odeur agréable, l’exposition à une odeur agréable augmente le sens de la réalité de manière significative. Cependant, l’exposition à l’odeur agréable n’a pas eu d’effet sur le sentiment de présence, quel que soit le degré de concordance entre l’odeur et l’EV. Des résultats secondaires intéressants relatifs aux taux de détection consciente des odeurs ainsi que l’impact potentiel de ce taux sur l’effet des stimuli olfactifs ont été obtenus. Quelle que soit la concordance entre la scène visuelle et l’odeur, le taux de détection consciente de l’odeur désagréable n’était jamais en dessous de celui de l’odeur agréable. De plus, le taux de détection de chacune des odeurs était plus élevé lorsque la scène visuelle était concordante avec cette même odeur. Un regard sur l’ensemble des trois études indique que l’effet de l’exposition aux stimuli olfactifs sur les sentiments de présence et de réalité s’est manifesté uniquement lorsque le taux de détection consciente était supérieur à 59%. Lorsque, dans un EV concordant avec l’odeur désagréable, le taux de détection consciente de l’odeur atteignait 95% et l’exposition au stimulus olfactif augmentait les sentiments de présence, réalité et réalisme. L’ensemble des résultats suggère que l’exposition à un stimulus olfactif peut augmenter les sentiments de présence, réalité et réalisme, mais que la détection consciente de l’odeur joue un rôle important dans cette relation. Les retombées théoriques et pratiques de ces résultats sont discutées et des pistes de recherche future sont sugggérées.
37

Adaptação do teste de olfato Sniffin' Sticks para uma população pediátrica brasileira / Adapting the Sniffin' Sticks smell test for a Brazilian pediatric population

Bastos, Laís Orrico Donnabella, 1987- 02 October 2015 (has links)
Orientador: Laura Silveira Moriyama / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Médicas / Made available in DSpace on 2018-08-26T18:25:47Z (GMT). No. of bitstreams: 1 Bastos_LaisOrricoDonnabella_M.pdf: 1963430 bytes, checksum: f359c8dc47c50a57d844495470f82792 (MD5) Previous issue date: 2015 / Resumo: A olfação encontra-se comprometida em várias doenças neurodegenerativas no adulto, mas os conhecimentos sobre perda olfativa em crianças são escassos. O teste de 16 odores do Sniffin' Sticks (SS16) é um dos mais utilizados mundialmente para testagem de identificação de cheiros, e já foi validado para adultos no Brasil. O objetivo deste estudo foi realizar uma adaptação do SS16 para a população infantil do Brasil e observar a influência de idade, sexo, rinite, nível socioeconômico e aspectos cognitivos sobre a performance no teste. Adaptações foram realizadas no teste para torná-lo mais familiar ao universo infantil, criando uma versão chamada SS16-Child. Além disso, um teste de identificação de figuras (PIT-SS16-Child) foi utilizado para avaliar aspectos cognitivos relacionados ao SS16-Child, como reconhecimento de figuras, nomeação e familiaridade com os 16 itens do teste. A versão final do teste foi então aplicada em 51 crianças, com idade média de 9.9 anos (variação 3-18 anos, desvio padrão= 4.25). Os dados demonstraram que os 16 odores foram facilmente identificados por crianças acima de 10 anos, e que mesmo para crianças pré-escolares (abaixo de 6 anos), pelo menos 5 itens foram altamente reconhecíveis (acima de 75% de reconhecimento). Não foi demonstrado efeito de sexo, rinite e nível socioeconômico sobre o teste de olfato. Os dados mostraram uma forte associação entre idade e performance no SS16-Child (r²=0.426, p<0.001), além de uma forte associação entre o idade e o resultado do PIT-SS16-Child (r2=0.436, p<0.001), que por sua vez também está associado com o desempenho no SS16-Child (p<0.001, r²=0.741). Análises multivariadas mostraram que o efeito da idade (p<0.05; B=0.171) e desempenho no PIT-SS16-Child (p<0.001; B=1.57) foram independentes quando ajustados estatisticamente um para o outro. Concluímos que o SS16-Child pode ser utilizado com adaptações para a população pediátrica brasileira, e que a interpretação dos resultados deve levar em consideração a idade do sujeito, e também seu desempenho no PIT-SS16-Child / Abstract: Olfaction is impaired in several neurodegenerative diseases in adults, but knowledge about olfactory loss in children is scarce. The 16 odors Sniffin' Sticks test (SS16) is the most widely used test of smell identification worldwide, and has been validated for adults in Brazil. The objective of this study was to adapt the SS16 to the pediatric population in Brazil and to study the influence of age, sex, rhinitis, socioeconomic status and cognitive performance on the test. Adjustments were made in the test to make it more familiar to the child's universe, creating a version called SS16-Child. In addition, a picture identification test (PIT-Child-SS16) was used to evaluate the cognitive aspects involved, including recognition of figures, naming and familiarity with 16 test items. The final version of the test was then applied in 51 children with a mean age of 9.9 years (range 3-18 years, standard deviation= 4.25). The data showed that the 16 odors were easily identified by children over 10 years, and even for preschool children (under 6 years) at least 5 items were highly recognizable (over 75% recognition). No effects of sex, rhinitis and socioeconomic status on the smell test were observed. The data showed a strong association between age and performance in SS16-Child (r²=0.426, p<0.001), and a strong association between age and the result of the PIT-SS16-Child (r2=0.436, p<0.001), which in turn was also associated with performance on the SS16-Child (p<0.001, r²=0.741). Multivariate analysis showed that the effect of age (p<0.05; B=0.171) and performance in the PIT-SS16-Child (p<0.001; B=1.57) were statistically independent when adjusted to one another. We conclude that the SS16-Child can be used with adaptations for the Brazilian pediatric population, and the interpretation of results must take into account the age of the subject, and also their performance in the PIT-SS16-Child / Mestrado / Ciencias Biomedicas / Mestra em Ciências Médicas
38

An Endocannabinoid System Is Present in the Mouse Olfactory Epithelium but Does Not Modulate Olfaction

Hutch, C. R., Hillard, C. J., Jia, C., Hegg, C. C. 06 August 2015 (has links)
Endocannabinoids modulate a diverse array of functions including progenitor cell proliferation in the central nervous system, and odorant detection and food intake in the mammalian central olfactory system and larval Xenopus laevis peripheral olfactory system. However, the presence and role of endocannabinoids in the peripheral olfactory epithelium have not been examined in mammals. We found the presence of cannabinoid type 1 (CB1) and cannabinoid type 2 (CB2) receptor protein and mRNA in the olfactory epithelium. Using either immunohistochemistry or calcium imaging we localized CB1 receptors on neurons, glia-like sustentacular cells, microvillous cells and progenitor-like basal cells. To examine the role of endocannabinoids, CB1- and CB2- receptor-deficient (CB1-/-/CB2-/-) mice were used. The endocannabinoid 2-arachidonylglycerol (2-AG) was present at high levels in both C57BL/6 wildtype and CB1-/-/CB2-/- mice. 2-AG synthetic and degradative enzymes are expressed in wildtype mice. A small but significant decrease in basal cell and olfactory sensory neuron numbers was observed in CB1-/-/CB2-/- mice compared to wildtype mice. The decrease in olfactory sensory neurons did not translate to impairment in olfactory-mediated behaviors assessed by the buried food test and habituation/dishabituation test. Collectively, these data indicate the presence of an endocannabinoid system in the mouse olfactory epithelium. However, unlike in tadpoles, endocannabinoids do not modulate olfaction. Further investigation on the role of endocannabinoids in progenitor cell function in the olfactory epithelium is warranted.
39

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.
40

A paradigm for exploring the impact of social isolation on olfactory sensitivity in mice

Daramola, Elizabeth 15 February 2024 (has links)
BACKGROUND: Mice have millions of olfactory sensory neurons that express one out of about 1,200 odorant receptor genes, giving them the ability to detect over 100,000 odorants. The activation of the sensory neurons is based on the different structural features of odor stimuli that each type of receptor has been genetically programmed to respond to. The activation at the level of the receptors corresponds to specific combinatorial codes for each odorant. Information from the receptors is sent to the olfactory bulb - where there is also a specific glomerular activation pattern for each odorant - and then to the olfactory tubercle, which plays a role in goal-directed behaviors and receives input from other parts of the brain that are essential for motivated behaviors. As a result of chronic social isolation, mice have been found to have impaired neurogenesis in their olfactory bulb, increased Tac2 expression, and decreased prefrontal cortex and hippocampal volumes. Since these neurological deficits alter the processing of olfactory information, using social isolation as a way to induce depression-like phenotypes in mice may provide insight into how changes in mental states are reflected in mouse behavior. OBJECTIVE: To determine the relationship between odor concentration and olfactory sensitivity in mice, and how the relationship is impacted by social isolation. METHODS: A total of 7 mice of either the C57BL/6J or tac1-cre strain aged 3-4 months were used. They underwent headplate surgery before going through habituation, after which they went through go/no-go task training. A custom 8-slot olfactometer and a behavioral box were used to run behavioral experiments, where up to 8 odorant tubes were placed in the olfactometer and mice were head-fixed in the behavioral box. Odorants were either blank odors made of only deionized water or different concentrations of n-butanol diluted in deionized water. With the blank odors as the “go” stimulus, the n-butanol odors as the “no-go” stimulus, and another blank odor as the “cheat” stimulus, mice went through go/no-go/cheat sessions over decreasing n-butanol concentrations. Python scripts were used to run experiments and collect data regarding the responses of the mice during each trial. RESULTS: By the end of the training period, mice were able to achieve an accuracy of at least 85% during go/no-go tasks. There is an overall downward trend in the performances of mice over decreasing n-butanol concentrations, but there were also large and unexpected improvements in performance at lower concentrations before and after isolation. There were many fluctuations in the average latencies to odor on incorrect no-go trials over decreasing n-butanol concentrations before and after the isolation period. Although sample sizes for each sex were too low for statistical analyses, preliminary data suggests that at low odor concentrations, social isolation might lead to enhanced performance in males and decreased performance in females. CONCLUSIONS: Mice can learn to associate novel odors with a water reward. Using social isolation as a way to induce depression in mice does not hinder mice from performing odor discrimination tasks. Conclusions cannot be made regarding the effect of social isolation on mouse olfactory sensitivity. Although there appears to be an improvement in performance as a result of isolation in male mice and a dampening of performance in female mice, further research will need to be conducted using larger sample sizes across both sexes.

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