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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.
221

Specification and Verification of Tolerances for Parts with Free-Form Surfaces

Kale, Kishor B January 2013 (has links) (PDF)
The need for increased product variety and improved aesthetics require the manufacturing enterprise to reduce time to market and to increase use of free-form surfaces in the form of the product. These changes lead to problems in the traditional approach for specification and verification of tolerances especially for a free form surfaces. In the case of freeform surfaces, the desired performance of a product depends on its geometry and is often controlled by intrinsic parameters such as curvature. Design intent therefore requires control on variations in these parameters. Ideally therefore, tolerances have to be applied on these parameters to prescribe allowable variations in the geometry of free-form surfaces. Since only the geometry of the product is controlled in manufacturing, tolerance specification has to ensure that the tolerances specified on the part geometry will ensure that the resulting value of the parameter of interest is within the limits prescribed by the designer. Relationship between allowable range in design parameters and that in geometry is not linear. Tolerance specification therefore becomes a trial and error process requiring considerable expertise and time. This thesis provides designers with a tool to automatically derive the corresponding tolerances to be specified to the manufacturing process to realize the final shape, such that the parameters that are used to control shape of the surface are within the prescribed variations. Automation in acquiring inspection data has brought dramatic changes in procedure for tolerance verification too. Optical scanners and similar non-contact devices provide large amount of points on the surface of the part quite rapidly. The unstructured point data are then processed to determine if the part complies with the given tolerance specifications. For freeform surfaces, current methods of verification uses minimum distance criterion between the nominal surface and unstructured point data. This ignores the correspondence between the points in the two data sets and may result in the rejection of good parts and acceptance of bad parts. There are other unresolved such as the singularity at corners of polyhedral shapes and handling datum. A new approach based on the Medial Axis Transform (MAT) has been proposed. It has been shown that reasoning on the MAT of the nominal model and the measured point set respectively enables the identification of corresponding points in the two sets. Verification of the tolerance allocated is therefore free from the problem mentioned above. MAT exhibits dimensional reduction and hence reduces verification time. It also eliminates surface fitting for detected feature. Results of implementation are provided for tolerance specification and verification using MAT.
222

L'anxiété liée au sevrage à la cocaïne : étude comportementale et neuroanatomique / Anxiety during cocaine withdrawal : behavorial and neuroanatomical study

El Hage, Cynthia 02 July 2012 (has links)
L’anxiété est un symptôme prédominant au cours des périodes initiales de sevrage à la cocaïne et est considérécomme un facteur important de rechute. Le but de cette étude était de caractériser les dysfonctionnementscérébraux qui pourraient contribuer à l’expression de cet état pathologique chez le rat.Les rats sont traités avec de la cocaïne en chronique et le comportement anxieux est évalué au cours du sevragedans différents paradigmes expérimentaux (tests du labyrinthe en croix surélevé, du confinement dans un brasouvert surélevé et de l’enfouissement défensif). Nos résultats ont montré que le sevrage à la cocaïne induit unétat anxieux élevé qui persiste pendant au moins 28 jours de sevrage. Nous avons ensuite utilisél’immunohistochimie de Fos pour comparer les patterns d’activation cérébrale chez les rats sevrés et témoinsaprès exposition au test de l’OA. Nos données ont montré que l’anxiété élevée des rats sevrés était accompagnéed’une altération de la réactivité des neurones glutamatergiques de la partie dorsale du cortex préfrontal médian(dCPFm) et de certaines régions sous-corticale (aires hypothalamiques latérale et antérieure et le noyauparaventriculaire du thalamus). Nous avons ensuite montré que l’inactivation pharmacologique du dCPFm avecdu muscimol atténuait les comportements anxieux des rats sevrés suggérant ainsi une hyperréactivité de cetterégion corticale durant le traitement des informations de type anxieux. Notre étude amène des données nouvellesquant aux substrats neuronaux sous-tendant l’anxiété pathologique observée au cours du sevrage à la cocaïne etsouligne l’importance du CPFm dans la régulation de cet état d’anxiété pathologique. / Anxiety is one of the prevailing symptoms observed during the initial period of abstinence in cocaine abusersand is considered as an important factor of relapse. The aim of this study was to provide further insight into thecerebral dysregulations that might contribute to this pathological state in rats.Rats were treated chronically with cocaine and anxiety-behaviors were assessed in different paradigms duringwithdrawal (elevated plus maze, open arm and shock probe burying tests). Our results demonstrated that cocainewithdrawal induced persistent heightened levels of anxiety that last for at least 28 days. We then used Fosimmunohistochemistry to map neuronal activation patterns in withdrawn rats confined to one open arm (OA) ofan elevated plus maze. Our data showed that the exacerbated anxiety observed in cocaine treated rats exposed toan OA was accompanied by an altered reactivity of the dorsal part of the medial prefrontal cortex (dmPFC)glutamatergic neurons and some sub-cortical regions (anterior and lateral hypothalamic areas and theparaventricular nucleus of the thalamus). Finally, we showed that pharmacological inactivation of the dmPFCwith muscimol considerably attenuated anxiety-related behaviors in cocaine withdrawn rats suggesting anexaggerated response of this cortical area during the processing of anxiogenic stimuli. The present studyprovides new data on the neural substrate underlying pathological anxiety observed during cocaine withdrawaland highlights the importance of the dmPFC in the regulation of this pathological anxiety state.
223

Writing as Reading the Unreadable: A Reconsideration of the Medial Construction of Marcel Proust's A la Recherche du temps perdu

Horlacher, Stefan 10 August 2020 (has links)
The question of how far A la Recherche du temps perdu, Proust's enormous 'metaphor of life',¹ is, in terms of its writing as well as in terms of its themes, influenced by the emergence of new media technologies in the late nineteenth century has increasingly been the focus of critical interest for the last twenty years.² There is now little doubt that besides traditional media such as painting and music, A la Recherclze foregrounds specific photographic and filmic techniques as well as, to give just one example, the telephone, which the narrator calls 'a premonition ( ... ) of an eternal separation!' {IS III, 148/R II,134).· If one can argue that emergent media as thematicized in A la Recherche are not only the product of the narrator's creation of memory but that they also have a bearing on the text, then it is nevertheless important to take note of the fact that they are in their turn already the product of another medium called writing. [Aus dem Volltext]
224

Neuropeptides et Néprilysines : rôle dans la mémoire chez la Drosophile / Neuropeptides and Neprilysins : role in memory in Drosophila

Turrel, Oriane 28 September 2017 (has links)
Au cours de ma thèse j’ai étudié les néprilysines (Nep), des protéinases connues pour dégrader de petits neuropeptides, en particulier les peptides amyloïdes (Aβ). Lors de la maladie d’Alzheimer, les peptides Aβ s’agrègent pour former des plaques toxiques. Il a été montré que l’expression des Nep module l’effet toxique d’Aβ sur la mémoire chez les modèles murins. Néanmoins, le rôle des Nep dans la mémoire dans des conditions physiologiques reste à ce jour inconnu.La drosophile exprime 4 Nep dans le système nerveux central adulte. Nous avons analysé leur rôle dans la mémoire olfactive. Les 4 Nep sont requises pour 2 phases spécifiques de mémoire: à moyen terme (MTM) et à long terme (LTM). De plus, nous avons identifié les neurones dans lesquels elles sont requises : les Mushroom Bodies (MB) ainsi qu’une paire de neurones afférents, les Dorsal Paired Medial neurons (DPM). Nous avons ensuite cherché à savoir si Aβ était l’une des cibles des Nep. Nous avons montré que l’expression d’Aβ dans les DPM n’altère la MTM que lorsque l’expression de Nep1 est inhibée. De plus, le défaut de LTM de drosophiles exprimant Aβ dans les DPM est sauvé par la surexpression de Nep1. En conclusion, nos résultats suggèrent qu’Aβ est dégradé par Nep1 au cours des processus de mémorisation, et qu’Aβ est une cible de Nep1 en conditions non pathologiques.Enfin, nous nous sommes intéressés au neuropeptide amnesiac, décrit comme étant requis pour la mémoire dans les DPM. Nos travaux démontrent qu’amnesiac est en fait requis dans les DPM pour leur développement, et chez l’adulte dans les MB pour activer l’adénylate cyclase responsable de la détection de coïncidence permettant la formation de la MTM. / During my PhD, I studied neprilysins, proteinases known to degrade small neuropeptides, in particular mammalian amyloid-β peptides (Aβ). During Alzheimer’s disease, Aβ peptides aggregate to form toxic plaques. It has been shown that neprilysins expression modulates toxic effects of Aβ on memory in murine models of the disease. However, the role of neprilysins in memory under physiological conditions is still unknown. Drosophila expresses 4 neprilysins in the adult central nervous system. First we have analyzed their role in olfactive memory. We have shown that all of them are required for 2 specific memory phases: Middle-Term Memory (MTM) and Long-Term Memory (LTM). We also have identified the neurons in which they are required: the Mushroom Bodies (MB) and a pair of afferent neurons, the Dorsal Paired Medial (DPM) neurons. Then we investigated whether Aβ peptides could be one of the neprilysins’ targets. We have shown that Aβ expression in DPM neurons alters MTM only when Nep1 expression is inhibited. Furthermore, the LTM deficit of flies expressing Aβ in DPM neurons is rescued by Nep1 overexpression. To conclude, our results suggest that Nep1 degrades endogenous Aβ peptides during memory processes, and that Aβ is a physiological target for Nep1 under non-pathological condition.Finally, we became interested in the amnesiac neuropeptide, described as being required for memory in DPM neurons. Our work shows that amnesiac is actually required in DPM neurons for their development, and in the MB of adult flies in order to activate the adenylate cyclase responsible for coincidence detection leading to MTM formation.
225

Zusätzliche inferomediale Schraube bei Nagelosteosynthese proximaler Humerusfrakturen - eine biomechanische Untersuchung am humanen Präparat

Bauer, Lisa 01 November 2016 (has links)
In der vorliegenden Studie wurde isoliert der biomechanische Effekt einer zusätzlichen, nicht-winkelstabil verriegelten, inferomedialen Kalkarschraube bei nagelosteosynthetischer Versorgung einer instabilen 2-Segment-Fraktur am proximalen Humerus im Vergleich zu einer Nagelosteosynthese ohne Kalkarschraube untersucht. Weiterhin wurde die Knochenmineraldichte in der inferomedialen Region des Humeruskopfes mit sechs umliegenden Regionen verglichen.16 Humeri von weiblichen Spendern waren in zwei Gruppen zu je acht Humeri aufgeteilt. Alle Präparate wurden mit dem MultiLoc® Humerusnagelsystem (DePuy Synthes, West Chester, USA) versorgt. Während die eine Gruppe (Basic) eine „Standardbesetzung“ mit drei proximalen und zwei distalen Bolzen aufwies, kam in der anderen Gruppe (Calcar) zusätzlich eine nicht-winkelstabil verriegelte Kalkarschraube zur Anwendung. Die Proben erfuhren Torsions- und Kompressionsbelastungen zur Ermittlung der Steifigkeiten, wurden zyklischen Belastungen ausgesetzt und unterlagen abschließend einer Belastung bis zum Versagen. Ein Vergleich der Gruppen ergab keine signifikanten Unterschiede. In Anbetracht einer verhältnismäßig hohen Knochenmineraldichte in der inferomedialen Region des Humeruskopfes erscheint das Konzept der zusätzlichen inferomedialen Abstützung als eine prinzipiell sinnvolle Methode. Allerdings erwies sich die Verwendung einer zusätzlichen nicht-winkelstabil verriegelten inferomedialen Kalkarschraube bei instabiler subkapitaler 2-Segment-Fraktur des proximalen Humerus als nicht biomechanisch vorteilhaft.
226

Písma, obsahy a čas. Vizuální komunikace / Alphabets, contents and the time. Visual communication

Tojnarová, Lenka January 2010 (has links)
The theme of the diploma dissertation became a view of a field of alphabets (letters and types) in contexts of communication, history, art and education. The theoretical part is focused on historical, contemporary movements of the phenomenon all at once. Inclusive of reflecting on alphabets in art and also links to a medial communication. The second part of the diploma dissertation reacts to the strongest and the most inspiring moments. It focuses on a practical applications for art lessons. The third part [artistic] takes advantage of media knowledges and art lessons. They are interfaced into an interactive teaching material which challenges students to an active perception of visual culture.
227

Handbollsspelares effektutveckling i olika riktningar

Mårtensson, Jesper January 2020 (has links)
The purpose of this dissertation is to analyze Swedish male handball players power in the lower limbs, dependent on position, in different anatomical planes. Previous studies has examined vertical and horizontal power but not medial lateral power. This study used previous studies as theory. Power was examined through vertical, horizontal and medial lateral CMJAS, unilateral and bilateral, in a laboratory setting. The vertical jumping performance was measured with ‘My Jump 2’ and the vertical power (W; W/kg) was calculated with Lewis formula. Only the jumping performance (cm) was noted in the horizontal and medial lateral CMJAS. No significance difference was observed (p>0.05) in power between the positions. A strong correlation between the vertical and horizontal CMJAS was observed (p<0.05; r=0.860-0.883). Conclusion, handball players, independent position, possesses similar power, bilateral and unilateral, in vertical, horizontal and medial lateral CMJAS. Medial lateral power needs to be examine to create a better profile of the player.
228

Association of Varus Thrust With Pain and Stiffness and Activities of Daily Living in Patients With Medial Knee Osteoarthritis. / 内側型変形性膝関節症患者における外側スラストと痛みとこわばり及び日常生活活動の関連性

Fukutani, Naoto 23 March 2016 (has links)
© [2015] American Physical Therapy Association. / 京都大学 / 0048 / 新制・課程博士 / 博士(人間健康科学) / 甲第19641号 / 人健博第33号 / 新制||人健||3(附属図書館) / 32677 / 京都大学大学院医学研究科人間健康科学系専攻 / (主査)教授 市橋 則明, 教授 山田 重人, 教授 妻木 範行 / 学位規則第4条第1項該当 / Doctor of Human Health Sciences / Kyoto University / DFAM
229

Analýza mediálního obrazu války na Ukrajině ve vybraných médiích / Analysis of the media image of the war in Ukraine in selected media

Naimushinova, Anastasiia January 2021 (has links)
The diploma thesis deals with medial images of selected events of the Ukraine War and their comparison in selected Ukrainian, Russian and Czech media. The aim of the diploma thesis is to identify, describe and compare medial images of key events of the Ukraine War in selected intelligence portals with various political orientation. The assumption is that there probably exist alternatives in opinion of the official Russian position in the frame of the Ukrainian and Czech media discourse. The first part of the thesis deals with theoretical concepts that are connected with propaganda and state-organised communication, and specifies the differences among them. Furthermore, a design of the research is introduced. The analytical part provides results and the content analysis detections in medial statements that were published in selected media between 20th February 2014 and 31st December 2014. The conclusion summarises the main detections of the research and their assets in the field of a propaganda survey.
230

Sensory Representation of Social Stimuli in Aromatase Expressing Neurons in the Medial Amygdala

Gualtieri, Charles J 14 May 2021 (has links)
The ability of animals to sense, interpret, and respond appropriately to social stimuli in their environment is essential for identifying and distinguishing between members of their own species. In mammals, social interactions both within and across species play a key role in determining if an animal will live to pass on its genes to the next generation or else be removed from the gene pool. The result of this selection pressure can be observed in specialized neural circuits that respond to social stimuli and orchestrate appropriate behavioral responses. This highly conserved network of brain structures is often referred to as the Social Behavior Network (SBN). The medial amygdala (MeA) is a central node in the SBN and has been shown to be involved in transforming information from olfactory sensory systems into social and defensive behavioral responses. Previous research has shown that individual neurons in the MeA of anesthetized mice respond selectively to different chemosensory social cues, a characteristic not observed in its upstream relay, the accessory olfactory bulb (AOB). However, the cause of this stimulus selectivity in the MeA is not yet understood. Here, I hypothesize that a subpopulation of neurons in the MeA that express the enzyme aromatase are involved in the sensory representation of social stimuli in awake, behaving animals. To test this hypothesis, I designed and built a novel behavioral apparatus that allows for discrete presentations of social stimuli in a highly controllable and reproducible environment. I then injected the adeno-associated virus (AAV) AAV-Syn-Flex-GCAMP6s into the MeA of Aromatase:Cre transgenic mice and implanted a fiber optic cannula slightly above the injection site. The combination of this transgenic mouse line and conditional AAV caused GCaMP6s expression to be exclusive to aromatase-expressing neurons. By coupling my novel behavioral apparatus to a fiber photometry system, I successfully recorded the moment-to-moment activity of aromatase neurons in the MeA of awake, behaving animals as they investigated various social stimuli. Aromatase neurons in the MeA of adult male mice respond strongly to conspecific social stimuli, including live adult mice, mouse pups, and mouse urine samples. Sniffing and investigative behaviors correlated strongly with increased GCaMP6s signal in aromatase neurons, reflecting increases in their neural activity. Interestingly, after repeated investigations of the same stimuli the activity of aromatase neurons gradually diminished. Presenting a novel stimulus following repeated investigations of a familiar stimulus reinstated some, but not all of the initial GCaMP6s signal. This points to the potential role that aromatase neurons may play in the habituation to social stimuli that are consistently present in their environment. Investigations of predator stimuli did not evoke significant responses from aromatase neurons, nor did investigations of non-social stimuli. These results demonstrate that aromatase expressing neurons in the MeA of awake, behaving animals encode the sensory representation of conspecific social stimuli, and their responses are highly selective to the type of stimulus presented.

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