Dissertations / Theses on the topic 'Focus of a lens'
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Valley, Pouria. "FLAT LIQUID CRYSTAL DIFFRACTIVE LENSES WITH VARIABLE FOCUS AND MAGNIFICATION." Diss., The University of Arizona, 2010. http://hdl.handle.net/10150/145737.
Full textYoung, William Russell. "The soft-focus lens and Anglo-American pictorialism." Thesis, University of St Andrews, 2008. http://hdl.handle.net/10023/505.
Full textDai, Hin Man. "Light weight low frequency sound focus lens /." View abstract or full-text, 2005. http://library.ust.hk/cgi/db/thesis.pl?PHYS%202005%20DAI.
Full textYoung, W. Russell. "The soft-focus lens and Anglo-American pictorialism /." St Andrews, 2008. http://hdl.handle.net/10023/505.
Full textYip, Chun Kwan. "The effects of lens focus when viewing stereoscopic micro-display images /." View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?IELM%202008%20YIP.
Full textCASTRO, SILVIA LIRA STACCIOLI. "FOCUS ON TRAUMA THROUGH THE LENS OF THE CLINICAL WITH MILITARY POLICEMEN." PONTIFÍCIA UNIVERSIDADE CATÓLICA DO RIO DE JANEIRO, 2009. http://www.maxwell.vrac.puc-rio.br/Busca_etds.php?strSecao=resultado&nrSeq=13743@1.
Full textA tese tem o objetivo de desenvolver um estudo acerca do trauma e de seus efeitos sob uma perspectiva dinâmica e não meramente econômica, como tem sido o caso de muitos estudos no campo da psicanálise até os dias de hoje, tendo como referência a observação clínica de atendimentos psicanalíticos prestados a policiais militares na cidade do Rio de Janeiro. Assim, além das noções de Schreck (susto) e de excesso de estímulo pulsional apresentados por Freud em 1920 para explicar o trauma a partir de uma invasão energética do aparato psíquico, incluiremos nesta pesquisa o papel do supereu, cuja imposição de gozo – masoquista – a serviço da pulsão de morte pode levar à compulsão à repetição do trauma. O trauma, que deve ser entendido como um esfacelamento das fantasias sexuais, faz com que as referências subjetivas estruturantes caiam por terra, processo que leva à sensação de aniquilamento psíquico, daí a idéia de que resta um corpo estranho no psiquismo. Identificado com o morto, o que gera um estado depressivo que ameaça a sobrevivência do sujeito traumatizado, ele pode se encontrar num estado melancólico ou até num estado paranóico, sem que seja um psicótico; visto que a ação superegóica de castigar e espezinhar o eu, que pode inclusive levá-lo a completar a ação não finalizada (morte), pode ser atribuída a um Outro (perseguidor), quando em realidade, esta ameaça é interna, como será mostrado em alguns casos clínicos.
The thesis has the objective of developing a study concerning trauma and its effects under a dynamic perspective and not merely economical, as it has been the case of many studies in the field of the psychoanalysis since now, taking as reference the clinical observation in psychoanalytic services rendered to the Military Policemen in the city of Rio de Janeiro. Besides the notions of Schreck (fright) and of an excess of energy invasion presented by Freud in 1920 to explain the trauma, we will include in this research the role of the superego, whose imposition of a masochist enjoyment at the service of the death drive can lead to the compulsion to repetition of the trauma. If we understand trauma as the shattering of the sexual fantasies, it causes the subjective references to dismount, a process that leads to the sensation of psychic annihilation. That is the reason of the idea that a strange body remains in the psyche. Identified with the dead, a position that generates a depressive state that endangers the subject s survival, he can fall in a melancholic state or even in a paranoid state, without being a psychotic; because the action of the superego of punishing and trampling on the ego, taking him to complete the inconcluded action (death), can be attributed to a pursuing Other, when, in reality, this threat is internal, as it will be shown in some clinical cases.
Ejdeholm, Dawid, and Jacob Harsten. "Detection of common envoirmental interferences in front of a camera lens." Thesis, Högskolan i Halmstad, Akademin för informationsteknologi, 2018. http://urn.kb.se/resolve?urn=urn:nbn:se:hh:diva-37350.
Full textRelina, Victoriya. "Reduced Susceptibility of Deformation due to Vibrational and Gravitational Effects on a Focus Variable Adaptive Lens." Master's thesis, University of Central Florida, 2013. http://digital.library.ucf.edu/cdm/ref/collection/ETD/id/5691.
Full textM.S.
Masters
Optics and Photonics
Optics and Photonics
Optics
Hassert, Jennifer C. "Gaining Focus: Using RNAi during Lens Development to Understand Emmetropization Mechanisms Found within the Diving Beetle Larvae Thermonectus Marmoratus." University of Cincinnati / OhioLINK, 2019. http://rave.ohiolink.edu/etdc/view?acc_num=ucin156387276836344.
Full textPoll, Zachary Brandon. "Commercialization Analysis: Exploring the Commercialization Opportunity and Market Demand for Variable Focus Liquid Lens as a Diagnostic Device." Thesis, The University of Arizona, 2014. http://hdl.handle.net/10150/321917.
Full textChang, Kam Man. "Eye fatigue when viewing stereo images presented on a binocular display : effects of matching lens focus with stereoscopic depth cues /." View abstract or full-text, 2008. http://library.ust.hk/cgi/db/thesis.pl?IELM%202008%20CHANG.
Full textWangshu, Gao, and Wang Guanhua. "How Influencers Marketing Motivates Consumers’ Buying Behaviour : A focus group investigation of the impulse buying behaviour via Chinese millennials’ lens." Thesis, Jönköping University, Internationella Handelshögskolan, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:hj:diva-48682.
Full textWu, Xia. "Theoretical evaluation of moderately focused spherical transducers and multi-focus acoustic lens/transducer combinations for high intensity focused ultrasound thermal therapy." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2001. http://www.collectionscanada.ca/obj/s4/f2/dsk3/ftp05/MQ63114.pdf.
Full textChristoffersson, Anton. "Real-time Depth of Field with Realistic Bokeh : with a Focus on Computer Games." Thesis, Linköpings universitet, Informationskodning, 2020. http://urn.kb.se/resolve?urn=urn:nbn:se:liu:diva-163080.
Full textWintr, Aleš. "Měření parametrů optických čoček." Master's thesis, Vysoké učení technické v Brně. Fakulta elektrotechniky a komunikačních technologií, 2011. http://www.nusl.cz/ntk/nusl-219103.
Full textNorman, Mary Ann. "Looking Through Their Lens: The Decisions about Reading Instruction Made by Experienced 2nd, 3rd and 4th Grade Teachers." Diss., Virginia Tech, 2008. http://hdl.handle.net/10919/28751.
Full textPh. D.
Dries-Tônnies, Thérèse. "Interfaces Homme-Machine et Théorie du Regulatory Fit : les caractéristiques graphiques d’interfaces Homme-Machine comme moyen d’adapter l’orientation stratégique des utilisateurs au type de tâche." Thesis, Montpellier 3, 2015. http://www.theses.fr/2015MON30026/document.
Full textTask-solving situations are often challenging our ability to approach them in the most adapted state of mind. Building on regulatory focus theory, we propose to use specific color and form characteristics to prime cognitive regulations that are likely to match either creative or accuracy framed tasks. In that line, a first study identified color and form characteristics as being involved in activating either a vigilant prevention cognition or a flexible promotion cognition. These findings were then used to visually design creative or accuracy oriented tasks. It was expected that a fit between the strategic orientations induced by these designs and tasks accuracy or creativity framing, would to positively influence both performance and overall subjective experience. Experimental results supported these predictions: Participants performed better when the visual design was composed of colors and forms inducing a regulatory orientation matching tasks' natures. Regulatory fit had also a global positive impact on subjective variables like fun and satisfaction. Overall, the results point out the advantage of taking benefit from visual characteristics' inherent priming potential. Our research can be related both to research domains (RFT, user experience research, color research) and to concrete applications in actual design processes
Minns, Michael David. "National Health Service (N.H.S.) mediation in focus : a psychoanalytic lens on the unconscious at work : how does conflict find its way into organisational life?" Thesis, University of Exeter, 2015. http://hdl.handle.net/10871/25894.
Full textWahyuni, Ias Sri. "Multi-focus image fusion using local variability." Thesis, Bourgogne Franche-Comté, 2018. http://www.theses.fr/2018UBFCK010/document.
Full textIn this thesis, we are interested in the multi-focus image fusion method. This technique consists of fusing several captured images with different focal lengths of the same scene to obtain an image with better quality than the two source images. We propose an image fusion method based on Laplacian pyramid technique using Discrete Wavelet Transform (DWT) as a selection rule. We then develop two multi-focus image fusion methods based on the local variability of each pixel. It takes into account the information in the surrounding pixel area. The first method is to use local variability as an information in the Dempster-Shafer theory. The second method uses a metric based on local variability. Indeed, the proposed fusion method weighs each pixel by an exponential of its local variability. A comparative study between the proposed methods and the existing methods was carried out. The experimental results show that our proposed methods give better fusions, both in visual perception and in quantitative analysis
Dufresne, Thérèse. "Through a lens of difference or when worlds collide: A poststructural study on error correction and focus-on-form in language and second language learning." Thesis, University of Ottawa (Canada), 2002. http://hdl.handle.net/10393/6111.
Full textNocaj, Arlind [Verfasser]. "Untangling Networks : Focus on Less to See More / Arlind Nocaj." Konstanz : Bibliothek der Universität Konstanz, 2016. http://d-nb.info/1114886882/34.
Full textOkyen, Michael Louis. "Biomimetic Bi-Pedal Humanoid: Design, Actuation, and Control Implementation with Focus on Robotic Legs." Thesis, Virginia Tech, 2013. http://hdl.handle.net/10919/50843.
Full textMaster of Science
Abboud, Candy. "Inférer et prédire les dynamiques d'espèces invasives : focus sur Xylella fastidiosa." Thesis, Aix-Marseille, 2019. http://www.theses.fr/2019AIXM0638.
Full textThe thesis research aims to provide a generic methodology that improves the predictions of an invasive species dynamics for which no dedicated model is available and whose initial conditions are unknown. In order to achieve this goal, we proceed in two complementary lines of research. The first one is to propose a model&data-based inference method of biological invasions, in the framework of the so-called mechanistic-statistical approach. This method allows us to jointly estimate the introduction point and other parameters of the dynamics related to diffusion, reproduction and death. It is hinged on (i) a partial differential equation (PDE) that offers a concise description of the invasive species dynamics in a heterogeneous domain, (ii) a stochastic model that represents the observation process and (iii) a statistical Bayesian inference procedure for estimating model parameters. We propose to replace the PDE by a model issued from the framework of Piecewise-deterministic Markov Process to balance the trade-off between model realism and estimation easiness. The second research line consists on accounting for the uncertainty about models form using the Bayesian model-averaging. This method consists of combining predictions drawn from competing models in order to obtain a unique and ameliorated prediction. This technique is not widespread in the field of epidemiology. One of the methodological goals of the PhD is to investigate its application and usefulness in predictive epidemiology. The case study of my thesis is the phytopathogenic bacterium Xylella fastidiosa which is susceptible to cause in France a major sanitary crisis as the one caused in Italy since 2013
Fender, Pascal. "Les multiples facettes des adénovirus : Focus à travers les dodécaèdres de l'Ad3 humain." Habilitation à diriger des recherches, Université de Grenoble, 2006. http://tel.archives-ouvertes.fr/tel-01063446.
Full textWong, Wing Shun. "The effects of matching lens focus with stereoscopic depth cues on the time taken to form a single stereoscopic image when viewing a binocular display : system prototyping and experimentation /." View abstract or full-text, 2007. http://library.ust.hk/cgi/db/thesis.pl?IELM%202007%20WONGW.
Full textEmberger, Simon. "Algorithmes, architecture et éléments optiques pour l'acquisition embarquées d'images totalement focalisées et annotées en distance." Thesis, Ecole nationale supérieure Mines-Télécom Atlantique Bretagne Pays de la Loire, 2017. http://www.theses.fr/2017IMTA0055/document.
Full textAcquiring the depth of a scene in addition to its image is a desirable feature for many applications which depend on the near environment. The state of the art in the field of depth extraction offers many methods, but very few are well adapted to small embedded systems. Some of them are too cumbersome because of their large optical system. Others might require a delicate calibration or processing methods which are difficult to implement in an embedded system. In this PhD thesis, we focus on methods with low hardware complexity in order to propose algorithms and optical solutions that extract the depth of the scene, provide a relevance evaluation of this measurement and produce all-in-focus images. We show that Depth from Focus (DfF) algorithms are the most adapted to embedded electronics constraints. This method consists in acquiring a cube of multi-focus images of the same scene for different focusing distances. The images are analyzed in order to annotate each zone of the scene with an index relative to its estimated depth. This index is then used to build an all in focus image. We worked on the sharpness criterion in order to propose low complexity solutions, only based on additions and comparisons, easily adaptable on a hardware architecture. The proposed solution uses bidirectional local contrast analysis and then combines the most relevant depth estimations based on detection confidence at the end of treatment. It is declined in three approaches which need less and less processing and thus make them more and more adapted for a final embedded solution. For each method, depth and confidence maps are established, as well as an all-in-focus image composed of elements from the entire multi-focus cube. These approaches are compared in quality and complexity with other state-of-the-art methods which present similar complexity. A hardware implementation of the best solution is proposed. The design of these algorithms raises the problem of image quality. It is indeed essential to have a remarkable contrast evolution as well as a motionless scene during the capture of the multi-focus cube. A very often neglected effect in this type of approach is the parasitic zoom caused by the lens motion during a focus variation. This "focal zoom" weakens the invariance aspect of the scene and causes artifacts on the depth and confidence maps and on the all in focus image. The search for optics adapted to DfF is thus a second line of research in this work. We have evaluated industrial liquid lenses and experimental nematic liquid crystal modal lenses designed during this thesis. These technologies were compared in terms of speed, image quality, generated focal zoom intensity, power supply voltage and finally the quality of extracted depth maps and reconstructed all in focus images. The lens and the algorithm which best suited this embedded DfF issue were then evaluated on a CPU-GPU development platform allowing real time acquisition of depth maps, confidence maps and all in focus images
Brigaud, Isabelle. "Réception phéromonale et sa modulation chez les Noctuelles : focus sur les mécanismes moléculaires impliqués." Paris 6, 2008. http://www.theses.fr/2008PA066555.
Full textBaudin, Grégoire. "Facteurs de risque environnementaux des troubles psychotiques : focus sur les expériences infantiles traumatiques." Thesis, Tours, 2018. http://www.theses.fr/2018TOUR2005/document.
Full textThis article thesis aimed to identify environmental risk factors (ERF) that are associated with the onset and the prognosis of non-affective psychotic disorders, in a French context. We based our work on Howes and Murray’s sociodevelopmental-cognitive model, and the sensitization model. Our results showed that one area-level environmental risk factor, namely the economic deprivation, and several aspects of childhood traumas, an individual ERF, are associated with an increased risk to develop psychotic disorders. Furthermore, we identified childhood traumas and cannabis consumption as modifier factors for these disorders. Finally, we sought to link our previous results, the two original models, and conceptual inputs from the theory of structural dissociation of personality in a coherent, clinically useful, and biopsychosocial framework. Our results suggest that both arealevel and individual environmental risk factors are involved in the onset and poor prognosis of psychotic disorders. They open perspectives for new therapeutic strategies
Hirschmann, Paula. "A Multidimensional Approach, Inspired by Depth Realism and the Criminological Imagination, to the Cartographic Exploration of Restorative Justice and the Reconstruction of this 'Chaotic Conception' into a ‘Double-Focus Analytic Lens’." Thesis, Université d'Ottawa / University of Ottawa, 2014. http://hdl.handle.net/10393/31468.
Full textCadena, Martínez Erasmo. "Enviromental impact analysis at full-scale OFMSW biological teatment plants. Focus an gaseous-emissions." Doctoral thesis, Universitat Autònoma de Barcelona, 2009. http://hdl.handle.net/10803/5332.
Full textAngel, Vincent. "Influence de la perception d'adéquation sur les buts et les stratégies : le role modérateurs des focus régulateurs." Nice, 2012. http://www.theses.fr/2012NICE2027.
Full textCefis, Marina. "Impact des modalités d'un exercice physique sur la neuroplasticité. Focus sur les sources de BDNF." Thesis, Bourgogne Franche-Comté, 2019. http://www.theses.fr/2019UBFCK049/document.
Full textPhysical exercise (EX) is recognized as the most potent non-pharmacological strategy to positively enhance brain health. From Human and animal studies there is a consensus to involve brain-derived neurotrophic factor (BDNF), a neurotrophin strongly expressed in response to EX and implicated in neuroplasticity mechanisms. Mainly expressed by neurons, BDNF is also expressed by endothelial and muscle cells. Largely sought during a physical effort, endothelium and skeletal muscle could be involved in positive effects induced by EX. Although there is a real consensus about BDNF and cerebral effect of EX, the typology of the better regimen of EX to enhance cerebral plasticity is not known. In this context, objectives of this works were to determine the impact of EX modalities on BDNF protein expression in different territory (brain, endothelium and muscle) and to identify mechanisms related in BDNF increases in response to EX.Our results showed that 1) BDNF expression in peripheral vessels from the same vascular territory (distinct internal diameter) is similar in response to EX, 2) cerebral BDNF increases induced by EX is dependent on EX intensity but not on the type of contraction (eccentric/concentric), 3) memory is restored by high intensity EX, 4) after EX, BDNF muscular expression is unchanged while the precursor of irisine (FNDC5) expression is increased, 5) BDNF expression depends on muscular fibers typology, 6) cerebral beneficial effects of EX intensity is might not be related to muscular irisine production.In conclusion, our data demonstrated that EX positively impact endothelial, cerebral but not muscular BDNF expression. Results highlighted the importance of the intensity parameter of EX on cerebral BDNF levels. Finally, according to our data, irisine and BDNF from the muscle might not be related to the cerebral increases of BDNF induced by EX intensity
Simiz, Jean-Gabriel. "Approche holistique du contrôle du focus en photolithographie 193nm immersion pour les niveaux critiques en 28nm et 14nm FD-SOI." Thesis, Lyon, 2016. http://www.theses.fr/2016LYSES059/document.
Full textThe increasing complexity in chip integration (co-integration, increasing diversity of matérials…) and the race to dimension shrinkage are the two main drivers of research in microelectronics today. The optical limitations of lithography have been reached some years ago so that double patterning is now a typical process flow in production and helps reducing pattern size and increasing design density. Because of these, the manufacturing itself needs to be more tightly controlled in order to avoid marginalities. Which will affect the chip operation. The cross-effects between these elements are more numerous and their ratio in the total budget is larger whereas the needs for tighter process control are rising. This thesis presents a holistic approach of the control of one of the main parameters for photolithography: focus. It is directly linked to the quality of the image transferred into the photoresist during exposure. Its control is then essential. Variability sources for focus are manifold and diverse: laser, mask, optical column, servo-controllers, wafer flatness, integration, design, substrate reflectivity, material quality etc. All these are added to each other, leading to the creation of defects which can be catastrophic such as shorts. The first objective of this work was to show current challenges raised by STMicroelectronics new technologies, specifically photolithography-wise and focus-wise. A budget breakdown of two critical processes (Metal line patterning in 28nm FD-SOI and Contact patterning for 14nm FD-SOI) has been established which gives the impact of every effect. The product layout effects were evaluated to represent up to 20% of the complete budget and 50% of its intra-chip component. Topography contributes to a large part of these effects and offline measurements showed up to 32nm 3s of height variation in a single field. This may lead to local defocuses of the same order of magnitude. The usable depth of field being about 60 to 70nm for the studied layers, it is clear that focus control is really tight here. The holistic approach of topology leaded to the use of data mining tooling as PLS regression (Partial least Square). It allowed the highlighting of main causes of topography, the creation of a predictive model of topology and the evaluation of several improvement solutions. One may distinguish “palliative” and “curative” solutions. In the first category, on may put scanner levelling improvements which might be effective for every technology without any modification to make on integration and design. The emulated wafer map methodology providing on-product focus non-uniformities without any measurements is also a solution for investigation. “Curative” solutions may concern the mitigation of risk factors by modifying the design topography built-up main factors
Omar, Hayat. "Les marqueurs –mm et dämmo dans la narration en amharique : approche développementale." Thesis, Lyon, 2017. http://www.theses.fr/2017LYSE2062/document.
Full textLanguages provide speakers with a wide range of linguistic units to organize and deliver information (Jisa, Reilly, Verhoeven, Baruch & Rosado, 2002). There are several ways to verbally express the mental representations of events. The speaker, according to the linguistic tools he has acquired, selects the one that brings out the most communicative effect to convey his message.Our study focuses on two markers in Amharic, -mm and dämmo, which abound in the language and in narratives in particular. Our aim is to examine, from a developmental perspective, how the speakers use them, and the functions these elements have in their narratives. We seek to distinguish the communicative and pragmatic functions indicated by means of these markers. To do so, we created a corpus of sixty narrative productions of children from 5-6, 7-8 to 10-12 years old and adult Amharic speakers. The material we used to collect our data is a series of pictures without text “Frog, Where are you?” (Mayer, 1969). This experimental material has already been used in many developmental studies and in several languages (Bamberg, 1987 ; Kail & Hickmann, 1992 ; Berman & Slobin, 1994 ; Kern 1997 ; Akinci, 1999 ; Strömqvist &Verhoeven 2003 ; Jisa, Chenu, Fekete & Omar, 2010 ; Fekete, 2011, Saïdi 2014 and many more).The results show that -mm and dämmo, although all the speakers use them both, do not always have the same scope according to the speaker and vary according to the age. dämmo is mainly used to mark a contrastive topic to signal the concomitance of the events. It seems to be easy to use for children compared to -mm which is much more complex, not only because of its synthetic structure but primarily because it is a multi-purpose morpheme. -mm anchors the information into the context, it highlights the constituent on which it operates
Hurel, Nolwenn. "Impact des infiltrations d'air sur les performances des bâtiments : focus sur l'étude expérimentale dans les parois ossature bois." Thesis, Université Grenoble Alpes (ComUE), 2016. http://www.theses.fr/2016GREAA018/document.
Full textPoor airtightness in buildings can lead to an over-consumption of energy and to many issues such as moisture damage and poor indoor climate. The timber frame constructions are particularly subject to air leakage and further knowledge in this field is needed to meet the regulation requirements tightened by the development of low-energy and passive houses. This study focuses on the impact of air infiltration on the buildings’ performance, both at the building and the wall assembly scales.The air infiltration through the envelope can disrupt the proper functioning of mechanical ventilation and increase the global energy load. This issue was first investigated numerically at the building scale on a wide range of housing and weather conditions. Simplified models working across the whole airtightness spectrum were established for the inclusion of natural infiltration in buildings’ total ventilation rate calculations. The airtightness was then considered at a smaller scale with the experimental characterization of timber frame wall assemblies, components and construction details, in particular with an original test set-up built for this purpose. A number of pressurization tests enabled to quantify the additional leakage air flow induced by specific airtightness defects and may be of use for building scale numerical simulations.The impact of air infiltration on the hygro-thermal performance of a wall is closely linked to the air dispersion inside it, but there is a lack of experimental studies and methods for the air path investigation. A new technique has therefore been developed, consisting in an innovative use of fluorescein micro-particles as tracer inside the insulation material. It was first applied to specific configurations: straight/angled air channels in contact with porous media. A simple analysis of the fluorescein concentration mappings enabled to investigate the impact of parameters such as the flow velocity, the insulation material and the geometry on the air infiltration in the glass wool, and gave evidences of phenomena such as the appearance of thin air gaps between the components of the wall. A fluorescein transport model was developed and coupled to a CFD model for finer analysis.Finally a case study on simple wall assemblies was carried out to compare experimental techniques, to verify their applicability to the air path study and to provide data for possible numerical model validation. The air dispersion at the inlet/outlet of the insulation was studied with both infrared thermography and the PIV. The air path inside the insulation layer was investigated using three experimental approaches: a temperature monitoring with thermocouples; a relative humidity monitoring with capacitive sensors SHT 75; and the use of fluorescein tracer micro-particles. The respective benefits and limitations of the various methods were identified to help in the selection of the most appropriate one for further studies
Dhayer, Melanie. "Régulation transcriptionnelle du tissu osseux lors de vols spatiaux : focus sur les cellules souches squelettiques et les ostéocytes." Thesis, Lyon, 2019. http://www.theses.fr/2019LYSES052.
Full textExposure to space conditions (absence of gravity and convection, confinement and radiation) represents an extreme and hostile environment for bone tissue. In vivo, space accelerates tissue aging, but in vitro embryonic or stem cells appear to preserve the stem character during their multiplication. In this context of duality, the objectives have been to understand in vivo in the mouse model the origin of bone loss during space flights but also why bone loss worsens on return to Earth. The increase in connectivity and dendricity of osteocytes as well as the opening of canaliculi could be the cause (deconditioning of osteocyte mechanosensors). The markers of adipogenesis and osteoblastogenesis, indicative of bone marrow stromal cell differentiation, are sensitive to flight conditions and could be the cause of spatial bone loss, which is a real danger for long-duration flights. During the SpaceX CRS-14 space mission, the differentiation balance of skeletal stem cells was studied during 18 days of exposure to microgravity by next-generation sequencing (Illumina) based on their mechanical memory. Indeed, amplification on standard culture media instils a mechanical memory, which is different depending on the passage (P3 vs P6). Cultured stromal cells in flight see all of their mechanomiRs fall, thus resetting the mechanical memory retained by the mechanomiRs to zero. In microgravity, the skeletal stem cell differentiation scale favours adipocyte differentiation, but the modulation of mechanical memory limits this phenomenon
Dabadie, Isabelle. "Une approche socio-anthropologique de la consommation collaborative : focus sur les nouveaux rapports à la propriété." Thesis, Rennes 1, 2017. http://www.theses.fr/2017REN1G020.
Full textCollaborative consumption refers to a highly varied range of practices – including rentals, loans, gifts, bartering and sharing between consumers – that challenge the primacy of individual ownership. This rapidly growing phenomenon has been the subject of many research studies that have attempted to define, map or explain it by identifying its determinants or evaluating its impact. Few researchers have focused on the cultural background to this movement. That is the focus of this study, which studies collaborative consumption from an anthropological perspective, looking at the central question of our relationship with ownership. This research, rooted in Consumer Culture Theory (CCT), adopts a phenomenological approach centred on the meaning of consumer experiences. In empirical terms, it uses an ethnographic study conducted in three different fields that reflect the diversity of collaborative practices: co-housing, collaborative pleasure boating and clothes libraries. Its main theoretical foundation is the use of an original analytical framework – cosmological infrastructure, inspired by the work of Stosczkowski (2008) – which highlights the salient traits of a particular worldview. The results reveal the emergence, within a movement that remains largely consumeristic, of a counterculture that is comparable to voluntary simplicity and characterised by a new relationship with ownership, which, for proponents of this counterculture, is not only replaced by the notion of usage but is also charged with different meaning. We call this the “cosmology of alter-possession”. This research provides a better understanding of the behaviour of consumers who maintain an ambivalent relationship with possessions, somewhere between detachment and the search for lasting links, and aspire to more open and collective forms of ownership in response to the social and environmental challenges in a world with finite resources
Lelièvre, Nicolas. "Développement des méthodes AK pour l'analyse de fiabilité. Focus sur les évènements rares et la grande dimension." Thesis, Université Clermont Auvergne (2017-2020), 2018. http://www.theses.fr/2018CLFAC045/document.
Full textEngineers increasingly use numerical model to replace the experimentations during the design of new products. With the increase of computer performance and numerical power, these models are more and more complex and time-consuming for a better representation of reality. In practice, optimization is very challenging when considering real mechanical problems since they exhibit uncertainties. Reliability is an interesting metric of the failure risks of design products due to uncertainties. The estimation of this metric, the failure probability, requires a high number of evaluations of the time-consuming model and thus becomes intractable in practice. To deal with this problem, surrogate modeling is used here and more specifically AK-based methods to enable the approximation of the physical model with much fewer time-consuming evaluations. The first objective of this thesis work is to discuss the mathematical formulations of design problems under uncertainties. This formulation has a considerable impact on the solution identified by the optimization during design process of new products. A definition of both concepts of reliability and robustness is also proposed. These works are presented in a publication in the international journal: Structural and Multidisciplinary Optimization (Lelièvre, et al. 2016). The second objective of this thesis is to propose a new AK-based method to estimate failure probabilities associated with rare events. This new method, named AK-MCSi, presents three enhancements of AK-MCS: (i) sequential Monte Carlo simulations to reduce the time associated with the evaluation of the surrogate model, (ii) a new stricter stopping criterion on learning evaluations to ensure the good classification of the Monte Carlo population and (iii) a multipoints enrichment permitting the parallelization of the evaluation of the time-consuming model. This work has been published in Structural Safety (Lelièvre, et al. 2018). The last objective of this thesis is to propose new AK-based methods to estimate the failure probability of a high-dimensional reliability problem, i.e. a problem defined by both a time-consuming model and a high number of input random variables. Two new methods, AK-HDMR1 and AK-PCA, are proposed to deal with this problem based on respectively a functional decomposition and a dimensional reduction technique. AK-HDMR1 has been submitted to Reliability Enginnering and Structural Safety on 1st October 2018
Lavergne, Rose-Anne. "Epidémiologie et mécanismes de résistance d'Aspergillus fumigatus aux antifongiques triazolés : focus sur les patients atteints de mucoviscidose." Thesis, Nantes, 2018. http://www.theses.fr/2018NANT1006.
Full textAspergillus fumigatus is an opportunistic filamentous fungus, causing various clinical manifestations. The first-line treatment of aspergillosis is triazole antifungal drugs. The emergence of the resistance of A. fumigatus to this class of antifungals is a worrying and monitored phenomenon. The most frequent resistance mechanism involves 14 - demethylase, the target enzyme of azoles (encoded by the cyp51A gene). Two origins of resistance have been proposed: the first related to the selection of resistant isolates during long-term antifungal treatment and the second, an environmental origin following the use of demethylation inhibitor fungicides in the environment. Our work highlighted, for the first time, the presence of TR46/Y121F/T289A isolates in France. Furthermore, the exploration of the genotypic link between clinical and environmental isolates carrying the TR46/Y121F/T289A alteration validated the hypothesis of the environmental origin of azole resistance. A prospective one-year study in cystic fibrosis patients confirmed a relatively high level prevalence of resistance together with the presence of wild-type cyp51A resistant isolates. The latter isolates were investigated for yet unidentified resistance mechanisms, initially analysing the sterol biosynthesis pathway. This work contributes to a better knowledge of the epidemiology and resistance mechanisms of A. fumigatus to azole drugs
Fallet, Manon. "Etude de la réponse environnementale et transgénérationnelle chez l’huitre creuse Crassostrea gigas : focus sur les mécanismes épigénétiques." Thesis, Perpignan, 2019. https://theses-public.univ-perp.fr/2019PERP0036.pdf.
Full textIndividual life history influences the phenotype and the phenotype of offspring. The different component of the heritability system including genetic and non-genetic heritability and their interactions are key mechanisms to generate these heritable phenotypes. Phenotype heritability can allow parents to transmit a better adaptive capacity in response to rapid local environmental changes, to their offspring. The pacific oyster Crassostrea gigas is a marine organism of economic interest as the main producing oysters worldwide. Oyster are sessile and filtering organisms which made them very sensitive to environmental pressures. Thus, the presence of pollutants and pathogens in the aquatic environment can have harmful consequences on oysters potentially leading to oysters’ death. The main objectives of my thesis were to decipher the part of different heritable mechanisms (genetic, epigenetic and microbiota) in the environmental response of oysters to two environmental stresses and to improve our knowledge about epigenetic transmission information in molluscs. During my PhD, I (i) realized a bibliographic study to identify main epigenetic factors implied in environmental response and heritability in molluscs ; (ii) study the influence of a parental exposure to a pesticide, the diuron, on the methylome and the gene expression of offspring and (iii) characterized the genetic, epigenetic, transcriptomic and microbiotic impact of an precocious microbial exposure on the survival capacity of pacific oyster when faced to Pacific Oysters Mortality Syndrome, a disease, inducing massive mortalities in oysters’ juveniles, thus on three generation. The main results of my PhD allow to highlight the influence of environmental stresses on phenotype by methylome modifications of oysters and their offspring. In the case of the response to POMS, the microbial exposure as allowed to improve the oysters’ resistance and constitute so an adaptive phenotype illustrating the potential role of epigenetic mechanisms in adaptive evolution
Endler, Gregor [Verfasser], and Richard [Gutachter] Lenz. "Adaptive Data Quality Monitoring with a Focus on the Completeness of Timestamped Data / Gregor Endler ; Gutachter: Richard Lenz." Erlangen : Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 2018. http://d-nb.info/1155590643/34.
Full textSotty, Jules. "Toxicité in vitro des particules atmosphériques fines et ultrafines : focus sur les bronchopneumopathies chroniques et la fonction mitochondriale." Thesis, Lille 2, 2019. http://www.theses.fr/2019LIL2S024.
Full textEpidemiological studies have highlighted an association between ambient particulate matter (PM) level and hospital admissions or even mortality related with exacerbation of asthma and chronic obstructive pulmonary disease (COPD). While the role of inhaled PM in exacerbating these pathologies has been reported, pathophysiological mechanisms initiating and maintaining airway inflammation are not yet well understood. Reported health issues seems to be mostly caused by finest particles, due to their ability to diffuse deeply in the lungs, where clearance is less effective. Although numerous experimental studies demonstrated the toxicity of fine particles (PM2.5), mainly through oxidative stress-induced airway inflammation, only few studies have paid close attention to the ultrafine fraction (PM0.1), which attains new properties at nanometric scale. Because of its high specific surface area, PM0.1 is likely to be more biologically reactive. In this study, in vitro assays were conducted, exposing differentiated models of human bronchial epithelial cells (HBEC), from healthy, asthmatic and COPD-diseased donors, to one or three low dose of PM0.18-2.5 and PM0.18. Cytotoxicity, extracellular secretion of proinflammatory mediators and gene expression were studied. Furthermore, mitochondrion is a major endogenous source of reactive oxygen species (ROS) through oxidative metabolism, and coordinate many cell survival signaling processes. In this context, alterations in mitochondrial dynamic and function might play a key role in maintaining PM-induced oxidative stress and inflammation within lung cells, especially in case of chronic lung diseases initiation and/or exacerbation. Human bronchial epithelial BEAS-2B cells were also acutely or repeatedly exposed to low doses of fine (PM0.18-2.5) or ultrafine (PM0.18) particles, in order to characterize mitochondrial dynamic and function without massive cell death. Results highlighted in this study should contribute to a better understanding of the mechanisms governing the initiation and/or exacerbation of chronic airway lung diseases induced by air pollution-derived fine and ultra-fine PM
Noly, Pierre-Emmanuel. "Mécanismes de la dysfonction ventriculaire droite dans l'hypertension pulmonaire : focus sur l’ischémie myocardique et les troubles du métabolisme mitochondrial." Thesis, Université Paris-Saclay (ComUE), 2017. http://www.theses.fr/2017SACLS535/document.
Full textRight ventricular failure is associated with an increased mortality in several clinical features, especially in patients with pulmonary hypertension. Underlying mechanisms of right ventricular dysfunction and failure in chronic pressure overload are complex and still subject to debate. The balance between the supply and the increased need in oxygen is crucial to maintain an adapted right ventricular function. However, an impairment of the myocardial microvascularisation could lead to myocardial ischemia and could participate to the transition between adapted and non-adapted right ventricular hypertrophy. As mitochondrion are involved in the entire oxygen-dependent energy production in cardiomyocytes, their integrity is also essential for a good right ventricular function. It is suggested that mitochondrial metabolism is impaired in right ventricular failure. However, only few data exist at the early stage of right ventricular dysfunction. To better understand the importance of such mechanisms, we used a model of chronic pulmonary hypertension in piglets.The first aim of this thesis was to study the association between microvascularisation impairment and right ventricular adaptation to chronic pressure overload. We compared two different piglet models of pulmonary hypertension. The first model was a systemic-to-pulmonary shunt (SHUNT) between the aortic arch and the pulmonary trunk. The second model reproduced thromboembolic pulmonary hypertension (CTEPH). In this work, we showed that early right ventricular dysfunction was associated with (1) a mismatch between microvascularisation and right ventricular hypertrophy as showed by a decreased capillary density, (2) an importance of the capillary density to right ventricular stroke work ratio and (3) an increased of myocardial fibrosis.In the second part of this thesis, we studied and compared the capillary density and myocardial fibrosis in right ventricles of 14 Eisenmenger Syndrome patients and 14 patients with chronic pulmonary arterial hypertension. All 28 patients had symptomatic right ventricular failure and underwent heart-lung transplantation in our institution. Capillary density was not different between the two groups and was almost 1.5-fold lower than in normal right ventricle, confirming the impairment of microvascularisation in these patients.In the third part of this work, we studied the mitochondrial respiratory capacities in the setting of right ventricular remodeling under chronic pressure overload. Thus, we showed that, in our swine CTEPH model, the mitochondrial respiratory capacities were globally and early impaired. The mitochondrial mass assessed in transmission electronic microscopy was not decreased. We didn’t observe any modification of substrate use over time.Taking together, these results showed that microvascular impairment and mitochondrial dysfunction had an important role in the early right ventricular dysfunction. Molecular pathways involved in both mechanisms are currently studied to find new targeted therapeutics
Muret, Kévin. "Annotation des ARN longs non-codants chez la poule et les espèces d’élevage : Focus sur les ARNlnc régulateurs du métabolisme des lipides." Thesis, Rennes, Agrocampus Ouest, 2018. http://www.theses.fr/2018NSARC139/document.
Full textGenome annotation is a major challenge in connecting genotypes with phenotypes. Identifying long noncoding RNAs (lncRNA) in genomes is part of this challenge; they are relatively low-expressed and have only been highlighted in 2012 thanks to the development of high throughput sequencing technologies. This research work has led to the identification of a large number of lncRNAs in livestock species, particularly in the chicken, in which no lncRNA had yet been described at the beginning of this thesis (2015). First, my aim was to identify these lncRNAs using liver and adipose tissue and to improve this catalogue by integrating other existing lncRNA public databases.Moreover, according to the literature, lncRNAs are involved in the regulation of any biological process, from gene expression to cell structure. One of the goals of our team is to understand the regulation of lipid metabolism in the chicken, I thus established the list of all lncRNAs known within the animal kingdom and involved in this metabolism or in adipogenesis, the process of storage and formation of adipose tissue. The conservation by synteny analyses revealed around twenty conserved lncRNAs in the chicken. From divergent abdominal fat weight chicken lines, I lastly identified new lncRNAs that potentially regulate this lipid metabolism
Lheureux-Thelliez, Stéphanie. "Evaluation préclinique de thérapies dirigées contre Bcl-xL et Mcl-1 dans les cancers de l'ovaire : focus sur les molécules BH3-mimétiques." Caen, 2013. http://www.theses.fr/2013CAEN4076.
Full textOvarian cancers are addicted to the anti-apoptotic proteins Bcl-xL and Mcl-1. In this context, the BH3-mimetic ABT 737 molecule appears therapeutically promising as it inhibits Bcl xL, although its activity in vitro is conditioned by Mcl-1 inactivation. In vitro, ABT-737 as a single agent was ineffective at promoting cell death in the four cell lines tested. Platinum compounds sensitize to ABT-737 by dose-dependently decreasing Mcl-1 expression or by increasing the expression of pro-apoptotic BH3-only proteins Noxa and, to a lower extent, Bim. Surprisingly in the ex vivo study on human ovarian cancer, we demonstrated that ABT-737 induced massive apoptotic cell death as a single agent and that its efficacy was not significantly improved when combined with carboplatin. Bim expression at baseline appears as a relevant biomarker that could be easily used in clinical practice for the selection of ovarian cancer patients in the development of a clinical trial using ABT-263. We also studied in vivo the interest of targeting the PI3K/Akt/mTOR pathway to overcome chemoresistance in ovarian cancer. BEZ235, a dual PI3K/mTOR inhibitor, induced a marked and homogeneous decrease in FDG uptake in a cisplatin-resistant ovarian cancer model, which was correlated to a significant decrease in cell proliferation and to a significant PI3K/mTOR pathways inhibition. Four days following treatment cessation, tumor recovery was observed and correlated to FDG SA-PET/CT findings. These data suggest that FDG PET could be of use for therapy monitoring of PI3K/mTOR inhibitors
Pook, Stuart. "Interaction et contexte dans les interfaces zoomables." Paris, ENST, 2001. http://www.theses.fr/2001ENST0024.
Full textBonnet, Jean-Baptiste Le Mauff Pierre. "Image du médecin généraliste par les patients étude auprès d'une population de l'agglomération nantaise par la méthode du focus group /." [S.l.] : [s.n.], 2008. http://castore.univ-nantes.fr/castore/GetOAIRef?idDoc=47731.
Full textSéité, Sarah. "Rôles de la méthionine sur le métabolisme hépatique de la truite arc-en-ciel (Oncorhynchus mykiss) : focus sur les mitochondries." Thesis, Pau, 2019. http://www.theses.fr/2019PAUU3007/document.
Full textThe expansion of the aquaculture industry in combination with limited availability and high prices of fishmeal has prompted feed producers to include more plant proteins in the aquaculture feeds. However, replacement of fish meal with plant proteins is often limited by the level of methionine in the alternative plant protein sources. Understanding of the different roles of methionine in fish is therefore essential to develop new diets and/or feeding strategies that are in tune with optimal fish growth, environmental and economic constraints. In this context, the main objective of this thesis was to characterize the effects induced by methionine deficiency on the hepatic mitochondrial metabolism in rainbow trout. The results obtained in our first study show that feeding trout with a methionine deficient diet leads to a decrease in growth performance associated with a decrease in both mitochondrial integrity and oxidative stress in the liver. We also demonstrate that these defects are accompanied by the induction of an autophagy-dependent mitochondrial degradation process (called mitophagy) as well as an increase in Endoplasmic Reticulum (ER)-stress and apoptosis. These original data published in Scientific Reports thus highlight the existence of close interactions between different cellular functions to cope to a dietary methionine deficiency. In addition to this short-term effect, we also demonstrate in a second study (submitted for publication in the Journal of Experimental Biology), that early nutritional stimulus during two weeks with a methionine deficient diet resulted in a long term programming of mitophagy. The enrichment of H3K4me3 and H3K36me3 in the liver of fish from methionine-deficient fry compared to their control counterparts suggests that epigenetic mechanisms are involved in these effects. Finally, in a third and last study, recently accepted for publication in Frontiers in Physiology, we sought to clarify, in primary culture of trout hepatocytes, the existing interactions between autophagy, ER homeostasis and intermediate metabolism under amino acid deprived conditions. Together, the results obtained in the present thesis extended our understanding of the role of dietary methionine at cellular level and emphasize the potential of this amino acid to apply new feeding strategies, such as nutritional programming, to optimize the nutrition and health of farmed fish
Cangini, Chiara. "Traduction et retraduction de Maria Chapdelaine. Recit du Canada français de Louis Hémon: focus sur les québécismes de ce roman." Master's thesis, Alma Mater Studiorum - Università di Bologna, 2016. http://amslaurea.unibo.it/10009/.
Full textBourguet, Nicolas. "Rôle de l'activité hydrolytique bactérienne dans le cycle de la matière organique en milieu marin : focus sur les enzymes lipase." Aix-Marseille 1, 2005. http://www.theses.fr/2005AIX11058.
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