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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.
131

Neuronal mechanisms of food perception

Ohla, Kathrin 06 October 2016 (has links)
Die sensorischen und hedonischen Eigenschaften von Essen sind wichtige Einflussfaktoren für die Nahrungsauswahl und –aufnahme. Was macht die Anziehungskraft von Nahrungsreizen aus? Die sensorischen und hedonsichen Eigenschaften von Nahrungsreizen werden mit allen Sinnen, oftmals sogar gleichzeitig, verarbeitet. Nahrungswahrnehmung ist damit ein mutlisensorisches Phänomen. Der Geruch, der Anblick, der Tasteindruck oder Geräusche können bereits vor der Nahrungsaufnahme wahrgenommen werden und Erwartungen hinsichtlich des Geschmacks auslösen. Diese prä-ingestiven Wahrnehmungseindrücke spielen daher auch eine maßgebliche Rolle bei der Entstehung von Verlangen und Gelüsten. Während der Nahrungsaufnahme, beim Kauen und Schlucken, spielen die chemischen Sinne, Schmecken und Riechen, eine besondere Rolle. Der Gesamtsinneseindruck aus den chemischen Sinneskanälen wird auch als Flavor bezeichnet. Wobei angemerkt sein soll, dass auch nicht-chemische Sinne, Sehen, Hören und Tasten, in die Flavordefinition einbezogen werden können. Zweifelsohne stellt die Nahrungsaufnahme ein komplexes Verhalten dar, das perzeptuelle, kognitive und Stoffwechselprozesse gleichermaßen umfasst. Die vorliegende Habilitationsschrift widmet sich der Untersuchung der neurokognitiven Mechanismen der visuellen, gustatorischen und flavour Wahrnehmung von Nahrungsobjekten und umfasst Untersuchungen zur Vulnerabilität der neuronalen Repräsentationen durch kontextuelle Reize. Zusammenfassend schließt die Arbeit mit der Feststellung, dass ein umfassendes Verständnis der psychophysiologischen Mechanismen der sensorischen und hedonischen Verarbeitung von Nahrungsreizen über alle Sinne die perzeptuelle Grundlage für nahrungsbezogenes Urteilen und Entscheiden darstellt. / What characterizes food and makes it so tempting? Sensory and hedonic information about food is conveyed by all senses, activated more or less simultaneously, having led to the notion that food perception is a multisensory experience. The smell, sight, touch or sound of a food can be experienced before ingestion and elicit expectations about the "taste" of that food based on previous encounters. It is, therefore, not surprising that these so-called pre-ingestive sensory experiences play a role in the formation of cravings and the elicitation of appetitive responses. Only during consumption, the chemical senses, smell, taste and oral touch and irritation, are experienced in the oral cavity as food is masticated and swallowed and gives rise to the overall experience commonly referred to as taste. While the term taste is, strictly speaking, incorrect as it does not refer to the gustatory perception, many languages including German lack an appropriate term for the holistic flavor experience arising from the food-induced stimulation of the chemical senses, gustation, olfaction and oral somatosensation in a minimalist interpretation, or, in a broader sense, of all our senses, including hearing and vision. Undoubtedly, feeding behavior is characterized by a complex interplay of perceptual, cognitive and metabolic processes and research on the mechanisms by which these processes regulate food intake behavior is only in its infancy. In this thesis, I present a series of studies aiming to elucidate the cortical representations of the visual, gustatory and flavor components of food objects along with evidence for the vulnerability of these presentations to contextual information. Together, I reckon that an understanding of the psychophysiological mechanisms of the sensory and affective processing of food objects mediated by our senses, seeing, smelling, tasting, feeling and hearing, represents the perceptual basis of food-related decision making.
132

Evaluation of Multi-sensory Feedback in Virtual and Real Remote Environments in a USAR Robot Teleoperation Scenario

de Barros, Paulo 26 April 2014 (has links)
The area of Human-Robot Interaction deals with problems not only related to robots interacting with humans, but also with problems related to humans interacting and controlling robots. This dissertation focuses on the latter and evaluates multi-sensory (vision, hearing, touch, smell) feedback interfaces as a means to improve robot-operator cognition and performance. A set of four empirical studies using both simulated and real robotic systems evaluated a set of multi-sensory feedback interfaces with various levels of complexity. The task scenario for the robot in these studies involved the search for victims in a debris-filled environment after a fictitious catastrophic event (e.g., earthquake) took place. The results show that, if well-designed, multi-sensory feedback interfaces can indeed improve the robot operator data perception and performance. Improvements in operator performance were detected for navigation and search tasks despite minor increases in workload. In fact, some of the multi-sensory interfaces evaluated even led to a reduction in workload. The results also point out that redundant feedback is not always beneficial to the operator. While introducing the concept of operator omni-directional perception, that is, the operator’s capability of perceiving data or events coming from all senses and in all directions, this work explains that feedback redundancy is only beneficial when it enhances the operator omni-directional perception of data relevant to the task at hand. Last, the comprehensive methodology employed and refined over the course of the four studies is suggested as a starting point for the design of future HRI user studies. In summary, this work sheds some light on the benefits and challenges multi-sensory feedback interfaces bring, specifically on teleoperated robotics. It adds to our current understanding of these kinds of interfaces and provides a few insights to assist the continuation of research in the area.
133

Biologinių ekstraktų, tinkamų Kolorado vabalo bulvių pasėliuose kontrolei, tyrimai / Researching of biological extracts for Colorado beetles in potatoes fields

Garbenis, Vaidotas 14 January 2009 (has links)
Darbo objektas – ekologiškai auginamos bulvės, kuriose pasireiškia kolorado vabalai. Darbo tikslas – įvertinti pušų ir gvazdikėlių ekstraktų poveikį kolorado vabalams bulvių pasėliuose. Darbo metodai – tyrimas buvo vykdomas 2007 m.. Bulvių sėkla daiginta 20 dienų šviesioje ir šiltoje patalpoje. Bandymas buvo įrengtas sodo sklypelyje. Pavasarį žemė įdirbta kastuvu. Mėšlas įterptas kastuvu 40 t ha-1 norma. Bulvių veislė „Rosela“. Pasodinta rankomis išmėtant bulves į padarytas vagutes. Bandymo bulvės buvo suskirstytos po dvi vagas purkšti ekstraktais, ir kontrolei. Purkšta pušų ir gvazdikėlių ekstraktų tirpalais. Dėl meteorologinių sąlygų (lietaus) bulvės jau buvo 10 – 15 cm kai pasirodė pirmieji kolorado vabalai. Po purškimų buvo stebima ar sumažėjo kolorado vabalų ir vertinama koks ekstraktas labiausiai paveikė kolorado vabalus. Nukasus bulves jų gumbai buvo sveriami. Nustatyta vidutinė vieno bulvių kero gumbų masė gramais, bei vidutinis gumbų skaičius vienetais. Purškiant buvo naudojami skydai, kad apsaugoti kitus variantus. Gumbų masė nustatyta svėrimo metodu. Purkštų pušų ir gvazdikėlių ekstraktų tirpalais bulvių derlius buvo lyginamas su kontroliniu variantu. Prieš pradedant vykdyti tyrimus, gegužės mėnesį buvo bandoma, kurią koncentraciją pasirinkti tolimesniams tyrimams (dėl vietos stokos ir bandymų vykdymo sudėtingumo). Preliminarūs tyrimai buvo atliekami dvejose vietose: Vokėje ir Šilalėje. Prieita nuomonės, kad 1% koncentracijos tirpalai mažai efektingi. Tuo tarpu... [toliau žr. visą tekstą] / Object of work – cultivation of ecologic potatoes, in which was found colorado beetles. Purpose of work – to estimate pine and clove extracts influence for pest (colorado beetles) into potatoes crops. Methods of work – the research had been conducting at 2007 y.. The seed of potatoes was cultivating in brightly and warm place for twenty days. The test was made in plot of garden. The soil was diged by spade on springtime. Manure was spread by spade 40 t. to hectare norm. The sort of potatoes „Rosela“. The potatoes was plant into furrows by hands. The researching potatoes was plant into to furrow, for sprinkling by extracts and for control. The potatoes was sprinkled by pine and clove extracts. Because of rain potatoes already was 10-15 cm. high, when appear first pests. After sprinkling was looking, if populiation of insects decrease, and testing which of extratcs was more effective. After potaoes gathering, it was weigh. Was find out a average weight of one potatoes growth bush, and average number of potatoes into bush. Was used screen to protect other rows of potato. The weight of lumps was found by weigh method. The harvest of sprinkled potatoes was compare with control rows. Before tests, was testing which concentration of extract to choose for research ( because of shortage of time, and complication of research). The research have been done in to place: Voke and Silale. I come to concliusion that 1% concentration extract aren‘t efective... [to full text]
134

Behavioural and physiological effects of two aniracetam analogues

Fisher, Kim Noël January 1994 (has links)
The behavioural and electrophysiological consequences of two newly developed aniracetam analogues were investigated in male Long-Evans rats. Results indicate that an intraperitoneal (i.p.) injection of LD38.2 significantly improved retention in a two odour olfactory discrimination task. However, three different dosages of LN1 did not facilitate memory in the task. In rats with chronically implanted electrodes, both compounds rapidly crossed the blood brain barrier (BBB) after an i.p. injection and influenced several parameters of the field excitatory postsynaptic potential (EPSP) in the CA1 and dentate gyrus regions of the hippocampus. The enhancement of the field EPSP following LD38.2 administration may be related to the drug's ability to facilitate memory in the olfactory discrimination task. Compounds, like LD38.2, that enhance both hippocampal transmission and performance in learning/memory tasks in laboratory rodents may have implications for the treatment of clinical memory disorders.
135

Nasal solitary chemoreceptor cells : cell turnover, nerve dependence, and detection capabilities /

Gulbransen, Brian D. January 2007 (has links)
Thesis (Ph.D. in Neuroscience) -- University of Colorado Denver, 2007. / Typescript. Includes bibliographical references (leaves 129-151). Free to UCD affiliates. Online version available via ProQuest Digital Dissertations;
136

The effect of the senses on consumers experience in clothing stores

Delemazure, Olivier, Mallégol, Olivier, Laplanche, Vincent January 2018 (has links)
This research explores the sensory marketing and more specifically the effect of the senses on consumers experience in the clothing distribution sector. The purpose of this paper is to understand if all the senses have an effect on the customer experience in clothing stores. To do this a primary quantitative data has been collected through a questionnaire from clothing store customers to assess the effect of different senses on their consumer experiences. The results obtained by the analyzing of the questionnaire through regression analysis concluded that there are two senses that really stand out of the lot, firstly the smell then secondly the sight.
137

The artificially scented ape : investigating the role of fragrances and body odours in human interactions

Allen, Caroline January 2015 (has links)
It was long believed that humans were unable to utilise the odours of conspecifics to co-ordinate social interactions in ways in which other species appear to be capable. However, a surge in interest in human social olfaction has recently challenged this view. The numerous studies conducted in this area have found that multiple state and trait related cues can be detected in body odour. Furthermore, many studies indicate that women are often more sensitive to these cues, and that sensitivity can be associated with fertility, findings that are consistent with sex differences in reproductive effort and benefits of choosiness in mate-searching. Since previous studies in this area have usually addressed the potential for humans to use olfactory communication in a comparable manner to other mammals, they typically involve collection and assessment of ‘natural’ odour. That is, they explicitly exclude the possibility of ‘contamination’ of odour samples by artificial fragrances. However, humans have used artificial fragrances for millennia, across many different cultures. This raises the question of whether widespread fragrance use may affect or disrupt the detection of this information in modern humans. The first aim of this thesis was to address this question by investigating how fragrance use may mediate the detection of olfactory information in humans. As well as providing further evidence for sex differences in the assessment of olfactory cues, and for the role of olfaction in real world partner choice, the findings herein suggest that fragrance may act differently on different information being assessed, potentially masking accurate assessment of certain traits (such as masculinity), while fragrance choice and preferences may be important in complementing other olfactory information (such as the general distinguishability of an individuals’ odour profile). A second aim of the thesis was to develop a scale in order to more accurately describe the varying perceptual qualities of human body odour – in other words to map human body odours. This work was conducted alongside perfumers in order to benefit from their expertise in olfactory perception and semantic labelling of odours. The development of such a scale could enable improved understanding of the perceptual qualities of human odour, making it possible to link specific perceptual qualities to specific cues (e.g. symmetry, masculinity, sex) or to manipulate odours based on perceptual qualities in experimental settings, and has direct practical implications for fragrance designers and for improving the ability of individuals to choose fragrance products that suit their odour profile. The second section of the thesis focuses on the effects of odours on the individual wearer as well as on perceivers in the environment. One study is presented which investigates the role of malodour reduction compared to the addition of fragrances in perceptions of confidence and attractiveness, finding that both the reduction of malodour and the addition of fragrance appear to be important for confidence as rated by others in the environment. The final study presented in the thesis examines a hitherto un-investigated role of olfaction during human pregnancy. The rationale for the study is based on evidence suggesting that in certain non-human species, which also show bi-parental care of offspring, there may be a role for chemical, or odour based, communication which underpins behavioural and endocrinological changes related to infant care behaviours in males. The study found little evidence to support the presence of analogous olfactory signalling during human pregnancy, though the findings are discussed in light of methodological changes which, if made in future studies, may result in different outcomes. The thesis concludes with a discussion of the importance of continuing to investigate various forms of olfactory communication, as well as improving our understanding of odours through the mapping of their perceptual qualities, and finally further examining the ways in which various fragranced products, which are widely used in society, may affect all of this. Future directions for this area of research are discussed. This line of investigation will, I argue, enable us to finally establish the true role of olfaction in contemporary social environments.
138

Genetic Dissection of the Neural Circuitry Underlying Memory Stability in Drosophila: A Dissertation

Keene, Alex Carl 22 August 2006 (has links)
Understanding how memory is formed requires looking beyond the genes involved to the neural circuitry and temporal aspects of memory. In this dissertation I have focused my investigation on Dorsal Paired Medial (DPM) neurons, two modulatory neurons essential for memory in Drosophila. DPM neurons highly express the amnesiac (amn) gene, which encodes for a putative pre-pro-neuropeptide. amn function in DPM neurons is required for memory. Here I provide evidence that DPM neurons are cholinergic and that acetylcholine (ACh) and AMN act as co-transmitters essential for DPM function. In order to investigate the temporal requirements of DPM output I blocked transmitter release during discrete intervals in the memory process using shibirets1 and tested flies for shock and sugar-reinforced memory. These experiments demonstrated that stable memory requires persistent transmitter release from DPM neurons. Furthermore these results suggest AMN and DPM neurons act as general stabilizers of mushroom body dependent memory. To further investigate the neural circuitry underlying DPM function I disrupted DPM projections onto the mushroom body lobes by ectopically expressing DScam17-2::GFP in DPM neurons. Flies with DPM neurons that predominantly project to the mushroom body α´/β´ lobes exhibit normal memory, and blocking transmitter release from the mushroom body prime lobes neurons themselves abolishes memory indicating DPM neuron-mushroom body α´/β´ neuron interaction that are critical for memory. Taken together, the experimental evidence presented here are used to provide a rudimentary model of the neural circuitry involved in memory stability, where DPM neurons form a recurrent feedback loop with the mushroom body α´/β´ lobe neurons and act to stabilize odorspecific conditioned memories at Kenyon cell synapses.
139

[en] IDENTIFYING DESIGN PROBLEMS WITH A VISUALIZATION APPROACH OF SMELL AGGLOMERATIONS / [pt] IDENTIFICANDO PROBLEMAS DE DESIGN ATRAVÉS DE UMA ABORDAGEM DE VISUALIZAÇÃO PARA AGLOMERAÇÕES DE ANOMALIAS DE CÓDIGO

OLOUYEMI ILAHKO ANNE BENEDICTE AGBACHI 21 November 2018 (has links)
[pt] Problemas de design decorrem de violações de princípios de design em um sistema de software. Tais problemas podem prejudicar a manutenção de sistemas e, logo, devem ser identificados e eliminados sempre que possível. Porém, identificar problemas de design não é trivial. Isso pois a documentação de design desses sistemas é em geral obsoleta ou inexistente. Assim, o desenvolvedor de um sistema tende a analisar o código-fonte em busca de problemas de design. Estudos sugerem anomalias de código-fonte como indicadores úteis desses problemas. Porém, outros estudos recentes mostram que uma única anomalia não é indicador suficiente. De fato, em torno de 80 por cento dos problemas de design estão associadas com múltiplas anomalias. Estas inter-relacionam-se na forma de aglomerações de anomalias. Embora as aglomerações de anomalias possam ajudar o desenvolvedor a identificar problemas de design, certas aglomerações contêm muitas anomalias. Isso então dificulta o raciocínio sobre a existência de um problema de design. Além disso, mesmo as propostas mais recentes de abordagens para a visualização de aglomerações de anomalias provêm suporte bastante limitado à identificação de problemas de design. Essa limitação é evidente quando um problema de design afeta múltiplos elementos na implementação de um sistema. Esta dissertação objetiva tratar essa limitação ao propor uma abordagem inovadora para a visualização de aglomerações de anomalias. Tal abordagem baseia-se em evidências coletadas a partir de vários experimentos propostos e conduzidos por nós. Contamos com a participação de desenvolvedores da academia e da indústria em cada experimento. Nossos resultados de estudo sugerem que vários desenvolvedores podem utilizar nossa abordagem de visualização para identificar de forma precisa problemas de design, especialmente aqueles que afetam múltiplos elementos de programa. Nossos resultados também apontam melhorias necessárias à abordagem com base na percepção dos desenvolvedores. / [en] Design problems are characterized by violations of design principles affecting a software system. Because they often hinder the software maintenance, developers should identify and eliminate design problems whenever possible. Nevertheless, identifying design problems is far from trivial. Due to outdated and scarce design documentation, developers not rarely have to analyze the source code for identifying these problems. Past studies suggest that code smells are useful hints of design problems. However, recent studies show that a single code smell might not suffice to reveal a design problem. That is, around 80 percent of design problems are realized by multiple code smells, which interrelate in the so-called smell agglomerations. Thus, developers can explore each smell agglomeration to identify a design problem in the source code. However, certain smell agglomerations are formed by several code smells, which makes it hard reasoning about the existence of a design problem. Visualization approaches have been proposed to represent smell agglomerations and guide developers in identifying design problems. However, those approaches provide a very limited support to the identification of specific design problems, especially the ones affecting multiple design elements. This dissertation aims to address this limitation by proposing a novel approach for the visualization of smell agglomerations. We rely on evidence collected from multiple empirical studies to design our approach. We evaluate our approach with developers from both academy and industry. Our results suggest that various developers could use our visualization approach to accurately identify design problems, in particular those affecting multiple program elements. Our results also point out to different ways for improving our visualization approach based on the developers perceptions.
140

[en] UNDERSTANDING HOW DEVELOPERS IDENTIFY DESIGN PROBLEMS IN PRACTICE / [pt] ENTENDENDO COMO OS DESENVOLVEDORES IDENTIFICAM PROBLEMAS DE PROJETO NA PRÁTICA

LEONARDO DA SILVA SOUSA 14 December 2018 (has links)
[pt] Um problema de projeto é a manifestação de uma ou mais decisões de projeto inadequadas que afetam negativamente requisitos não funcionais. Por exemplo, Fat Interface, um problema que indica quando uma interface expõe serviços não coesos, no qual dificulta a extensibilidade e a manutenibilidade de um sistema de software. Apesar de problemas de projeto serem prejudiciais aos sistemas, identificá-los é uma tarefa difícil, especialmente quando o código-fonte é o único artefato disponível. Embora pesquisadores venham investigando técnicas para ajudar os desenvolvedores a identificar problemas de projeto, há pouco conhecimento sobre o processo de identificar problemas de projeto. Por exemplo, anomalias de códigos, um indicador de problemas de projeto, têm sido usadas para ajudar desenvolvedores a identificar problemas de projeto. No entanto, ainda não sabemos se elas são suficientes para ajudá-los ou não. Em particular, nenhum estudo tentou entender como os desenvolvedores identificam problemas de projeto. Nesse contexto, nós realizamos alguns estudos para entender a identificação de problemas de projeto. Em nossos dois primeiros estudos, nós investigamos o papel que as anomalias de código desempenham durante a identificação de problemas de design. Nossos resultados indicam que as anomalias de código são relevantes para os desenvolvedores na prática, por exemplo, eles são relevantes para indicar elementos a serem refatorados. Apesar da relevância, descobrimos que as anomalias de código não são suficientes para ajudar os desenvolvedores a identificar problemas de projeto. Nesse sentido, conduzimos outro estudo para investigar quais outros indicadores os desenvolvedores usam na prática e como eles são usados. Este estudo resultou em uma teoria sobre como os desenvolvedores identificam problemas de projeto na prática. A teoria revela quais são os indicadores que os desenvolvedores usam, como eles usam esses indicadores e as características de tais indicadores que os desenvolvedores consideram úteis. Os resultados encontrados nos forneceram uma melhor compreensão do processo de identificação de problemas de projeto, abrindo caminho para a elaboração de técnicas mais eficazes em ajudar os desenvolvedores a identificar problemas de projeto. / [en] A design problem is the manifestation of one or more inappropriate design decisions that negatively impact non-functional requirements. For example, the Fat Interface, a problem that indicates when an interface exposes non-cohesive services, hampers the extensibility and maintainability of a software system. Despite its harmfulness, identifying a design problem in a system is difficult, especially when the source code is the only available artifact. Although researchers have been investigating techniques to help developers in identifying design problems, there is little or no knowledge about the process of identifying design problems. For instance, code smells, microstructures that are a surface indication of design problems, have been used in several techniques to support developers during the design problem identification. However, there is no knowledge if code smells suffice to help developers to identify design problems. In particular, no study has tried to understand how developers identify design problems in practice. Thus, in this thesis, we have conducted a series of studies to understand design problem identification. In our two first studies, we investigated the role that code smells play in supporting developers during the design problem identification. Our results indicate that code smells are relevant for developers in practice; for instance, they are relevant to indicate elements that need to be refactored. However, we found that code smells, despite their relevance, do not suffice in helping developers to identify design problems. In this vein, we conducted another study to investigate what indicators developers use in practice, and how they use them. This study resulted in a theory about how developers identify design problems in practice. For instance, the theory reveals the indicators that developers use, how they use these indicators, and the characteristics of such indicators that are perceived as helpful by developers. The results found by our studies provided us with a better understanding of the process of identifying design problems thitherto nonexistent. Moreover, our findings pave the way for the elaboration of more effective techniques to identify design problems in the source code.

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