Dissertations / Theses on the topic 'Rats – Expérience'
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Helder, Rémi. "Contribution à l'étude expérimentale du déterminisme de l'organisation sociale dans des groupes de rats." Nancy 1, 1995. http://www.theses.fr/1995NAN10015.
Benhaddou, Soukaïna. "Étude de la biodisponibilité digestive et métabolique des protéines alimentaires après bypass gastrique." Electronic Thesis or Diss., université Paris-Saclay, 2024. http://www.theses.fr/2024UPASB005.
Bariatric surgery stands as the most effective treatment for morbid obesity, with the Roux-en-Y Gastric Bypass (RYGB) being a commonly employed procedure. Its efficacy in weight loss and the reduction of comorbidities has been extensively demonstrated. Despite its frequent association with protein deficiency, the consequences of RYGB on the digestive and metabolic availability of proteins remain poorly understood. This thesis aims to assess the effects of RYGB on the digestive and metabolic fate of dietary proteins, using a test meal containing ¹⁵N labeled milk proteins in both rats and humans. Rats were monitored for 1 or 3 months post-RYGB to evaluate its mid-term effects on the intestinal mucosa, digestibility, and metabolic availability of dietary proteins. This study showed that protein digestibility was not altered by RYGB, even though the intestinal mucosa is hypertrophied. A transient decrease in nitrogen retention in peripheral organs and a persistent increase in deamination of dietary amino acids (AA) were observed. In humans, the metabolic fate of proteins was assessed one month before and six months after RYGB in 4 patients over 9 included (NCT04934826). Three of them exhibit a mild to marked increase in AA catabolism. RYGB induced variable modifications in dietary nitrogen metabolism among individuals. This thesis demonstrated that RYGB alters the metabolic availability of proteins, mainly through an increase in postprandial catabolism of AA. In addition to these studies, the development of small intestinal organoids of rats was conducted to mimic intestinal modifications after RYGB. The organoids exhibit substantial variability (size, shape, and gene expression), with no differences observed between those derived from control rats and RYGB rats
Addou, Samia. "Conséquences de l'adaptation à un régile hyperprotéique sur la structure de l'épithelium intestinal chez le rat Wistar." Paris, AgroParisTech, 2008. http://www.theses.fr/2008AGPT0001.
Dietary proteins are derived from animal and plant food stuff. The evaluation of the nutritional quality of dietary proteins of different sources consists of relating the characteristics of food intake and energy requirement of the organism. The recommendation by WHO/UNU is of 0. 8g/kg/day of high quality protein for the adult man. This work aims to evaluate the consequences of a high-protein diet on the functional and morphological modification in the growing rat. In particular, we measure the effect of a 50% protein diet on body weight, weight of several organs and intestinal structure. For that purpose, 96 male wistar rats weighing between 175 and 185g (180±2,27g) are divided in 5 groups. The 1st group (n=30) receives an averageprotein level diet (14%) and constitutes the control group. The 2nd group (n=12) receives an highprotein diet (50%) The 3rd group (n=12) receives a diet based on plant proteins (14. 5%) the 4th group (n=12) receives a diet based on soya (50%) the 5th group (n=12) receives a diet based on gluten (50%). All diets are administered during a period of 60 days. Our results show that a high intake of dietary proteins results in significant body weight loss and causes modification of the histological structure of the intestinal epithelium, with an atrophy of the villaea accompanied with an important increase of intra-epithelial lymphocytes. 2These modifications could be the consequence of toxic reactions induced by a chronic/regular exposure of the intestinal epithelium to high levels/quantities of proteins. We conclude that an over-consumption of proteins has consequences on the body composition and intestinal function. Therefore, the long-term use of high-protein diets in man should be monitored more closely
Warin, Jean-Louis. "Conditions d'élevage et performances : contribution à l'étude de l'influence des facteurs environnementaux sur les comportements individuels et sociaux du rat de souche Wistar." Nancy 2, 2002. http://docnum.univ-lorraine.fr/public/NANCY2/doc134/2002NAN21023.pdf.
For half a century a model (environmental impoverishment Vs enrichment) has been used to examine, mostly in rodents, the modifications triggered by various rearing conditions. It has been shown that these conditions produce biological as well as behavioral changes. Yet, there are many insufficiences, which are highlighted in a detailed theoritical methodological review. To improve this experimental model, the study focuses on the behavioral influences of an enriched environment compared with standard rearing conditions of laboratory rats. To achieve this, individual performances of the subjects were evaluated with exploration, anxiety and learning tests. Results show that rats reared in a more stimulating environment are more active than their standard counterparts. This behavioral reactivity can be attributed to a better adaptibility to novelty, but it also shows enhanced cognitive abilities. In addition, rats were confronted with a situation of social differentiation, in which emerged roles based around the capacity to get food. The confrontation of rats from the same rearing condition leads to a similar role pattern. Yet, the confrontation of rats from both rearing conditions greatly changes the role differentiation : standard rats tend to become food suppliers whereas enriched rats become mostly stealers. This role segragation may be attributed to the difference in the space available in rearing cages, and to the interactions engendered. In short it is apparent that a period spent in an enriched environment not only enables to improve rats' individual performances, but also that it has an effect on social interactions. The consequences of more stimulating rearing conditions are examined, and extrapolatory perspectives are discussed
Kourrich, Saïd. "Rôle des canaux Kv1. 1 et Kv1. 3 au cours des processus mnésiques chez le rat." Aix-Marseille 1, 2001. http://www.theses.fr/2001AIX11037.
Lenck-Santini, Pierre-Pascal. "Etude des relations entre l'activité des cellules de lieu hippocampiques et les propriétés des comportements spatiaux chez le rat." Aix-Marseille 1, 2002. http://www.theses.fr/2002AIX11034.
Bourgeon, Stéphanie. "Remodelage des cartes du cortex somesthésique dépendant de l'expérience sensorielle et corrélats perceptifs : approches électrophysiologique et comportementale chez le rat adulte." Aix-Marseille 1, 2003. http://www.theses.fr/2003AIX11031.
Truchet, Bruno. "Plasticité synaptique et mémoire : étude des changements d'efficacité synaptique au niveau hippocampique au cours d'un apprentissage olfactif associatif chez le rat." Aix-Marseille 1, 1999. http://www.theses.fr/1999AIX11076.
Vries, Philine de. "Développement post natal et ciblage nutritionnel du système nerveux entérique : étude chez le raton nouveau-né." Nantes, 2013. http://archive.bu.univ-nantes.fr/pollux/show.action?id=00363864-558d-4cb2-9e04-f7012a6c2bff.
Digestive dysfunctions are often observed in premature child, such as slowing of intestinal transit to ulceronecrotizing enterocolitis. These symptoms could be a source of morbidity. The enteric nervous system (ENS) is known to be a major regulator of digestives functions. At birth, the child is submitted to environmental factors, and the GI tract is submitted to the influence of nutrients and their derivatives, such as butyrate. The commensal intestinal flora also has close ties with the GI tract. We first studied the maturation of rat pups ENS, and its impact upon the colonic motor functions. Few spontaneous contractions of the colon appeared at P5. Starting P14 rhythmic phasic contractions appeared whose frequency increased over time until P36. In addition, EFS induced contractions were significantly reduced by atropine from P14, while the proportion of ChAT-immuno reactive neurons increased significantly over time. Daily intrarectal administration of 2. 5 mM butyrate, to the pups from P7 to P17, increased the proportion of nitrergic and cholinergic cells and increase colonic motility in vivo. Ex vivo the motor response to EFS were disrupted in the presence of atropine and L-Name. Perinatal administration of oral Metronidazole to pups until P21, altered sensitivity to inflammation. Functional maturation of the colon and structural changes of the SNE occured after birth. Food and antibiotics can influence their development. This opens perspectives for the prevention and treatment of intestinal disorders in premature infants
Augier, Benoît. "Études expérimentales de l'interaction fluide-structure sur surface souple : application aux voiles de bateaux." Phd thesis, Université de Bretagne occidentale - Brest, 2012. http://tel.archives-ouvertes.fr/tel-00816348.
Fabre, Hélène. "Exercice physique et phytoestrogènes : effets sur la fonction endothéliale et le métabolisme osseux de la rate." Besançon, 2006. http://www.theses.fr/2006BESA3008.
The aim of the present work was to study, in old or ovariectomized female rats, the effects of exercise training combined or not with Humulus Lupulus L. (hop) supplementation, on endothelial function and bone metabolism. Our results show that isometric strength training improves endothelialfunction in ovariectomized female rats, via nitric oxide (NO), cycIooxygenase, sarco-endoplasmic reticulum Ca2+-ATPases (SERCA) pathways and by endothelium-derived hyperpolarizing factor (EDHF). Aqueous hop extract induces relaxation of endothelium-intact thoracic arterial rings in male and sham-operated rats, whereas a weak dilative effect is observed in ovariectomized rats. Endothelium dependent (EDV) and independent (ElV) vasodilation, in old female rats, decrease after long-term consumption of Humulus Lupulus L. Diet. Moreover, isometric strength training performed during the first part of life, associated with daily long-term hop consumption, do not improve EDV in old female rats. This phenomenon can be explained by the decrease in EDV of senescent female rats after 2 years of hop-enriched diet and by the training ceases, which can reverse the possible isometric exercise-induced changes in endothelial function. On bone metabolism, we demonstrated that a 25-week isometric strength training, performed during young adulthood, followed by a prolonged detraining period, increase bone mineral density values and osteocalcin/deoxypyridinoline ratio in female trained rats. Thus, bone gains induced by exercise do not decrease immediately after cessation of training. On the contrary, long-term daily consumption of Humulus Lupulus L. -enriched diet does not improve bone parameters. To conclude, the use of isometric exercises in training programs for postmenopausal women, probably represents an alternative exercise modality and could contribute to the prevention of menopause-related endothelial dysfunction. Practice of physical activity during the first part of life seems to maximize peak bone mass and consequently limit age-related bone loss. On the contrary, after a prolonged detraining period, benefits induced by exercise on cardiovascular system are lost. This highlights the importance of a regular practice of physical activity to maintain benefits from exercise training. Finally, in vitro hop is a strong vasodilator in male and intact female rats. However, today it is still premature to recommend this plant in the prevention of endothelial dysfunction
Maurice, Claire. "Textures de compression plane à chaud d'alliages d'aluminium : expériences et simulations." Grenoble INPG, 1994. http://www.theses.fr/1994INPG4208.
Khier, Mohammed. "Estimation du taux de panne." Grenoble 2 : ANRT, 1987. http://catalogue.bnf.fr/ark:/12148/cb37606568t.
Marcelin, Béatrice. "Réorganisation fonctionnelle dans un modèle d'épilepsie du lobe temporal avant et après chirurgie Gamma Knife : de la protéine au réseau." Aix-Marseille 2, 2009. http://www.theses.fr/2009AIX20684.
Ahmed, Dhafar Ibrahim. "Experimental and numerical study of model gravity currents in coastal environment : bottom gravity currents." Thesis, Brest, 2017. http://www.theses.fr/2017BRES0060/document.
The aim of this investigation is to contribute to a better understanding of the propagation dynamics and the mixing process of dense gravity currents. The Laboratory experiments proceeded with a fixed initial gravity current concentration in one experimental set-up. The gravity currents are injected using a rectangular injection channel into a rectangular basin containing the ambient lighter liquid. The injection studied is said in unsteady state volume, as the Reynolds number lies in the range 1111 - 3889. The experiments provided the evolution of the boundary interface of the jet, and it is used to validate the numerical model. The numerical model depends on the Reynolds-Averaged Navier Stokes equations (RANS). The k-ε (K-epsilon) and the Diffusion-Convective Equation (DCE) of the saline water volume fraction were used to model the mixing and the propagation of the gravity current jet. On the other hand, comparison of the mean flow (z⁄z0.5 =U/Umax) with previous two-dimensional numerical simulations and experimental measurements have shown similarities. The numerical simulations of the hydrodynamic fields indicate that the velocity maximum at 0.18 z0.5, where z0.5 is the height at which the mean velocity u is the half of the maximum velocity Umax
Nourgalieva, Kalamkas J. "Effets biologiques des faibles doses d'irradiation sur les organismes humains et animaux : observations et expériences effectuées en France et au Kazakhstan entre 1995 et 2000." Rennes 1, 2003. http://www.theses.fr/2003REN1B079.
Karim, Yacin. "Vers une vérification expérimentale de la théorie de la relativité restreinte : réplication des expériences de Charles-Eugène Guye (1907-1921)." Phd thesis, Université Claude Bernard - Lyon I, 2011. http://tel.archives-ouvertes.fr/tel-00839315.
Almakari, Michelle. "Réactivation Hydro-Mécanique d’une Faille Rate & State ˸ Glissement, Sismicité et Évolution de Perméabilité." Electronic Thesis or Diss., Paris Sciences et Lettres (ComUE), 2019. http://www.theses.fr/2019PSLEM065.
This PhD thesis is dedicated to the study of injection induced fault reactivation using a coupled hydro-mechanical rate and state modelof a fault. Even though the principal mechanisms behind induced fault reactivation are well known, different aspects are not yet fully explored, nor understood. In the first part of this thesis, we explore successively the role of the injection protocol (in particular, injection maximum pressure and injection pressure rate), and the fault frictional parameters on the rate of induced events and their magnitude content, for different heterogeneous 2-D fault configurations. We first point out a temporal correlation between the seismicity rate and the pore pressure rate governing the fault. We then show a dependence of the rate and magnitude content of the seismic events on the injection parameters, as well as the existence of an important trade-off between them, which could not be addressed using the Dietrich(1994)’s seismicity rate model. Concerning the frictional parameters, we show that for the faults tested in this study, the ones having a more stable frictional behavior exhibit a lower induced seismicity rate and seismic moment released. In the last part of this study, the variation of the hydraulic diffusivity during fluid injection with shear slip and effective stress reduction is addressed. For this, we use laboratory injection experiments on an Andesite rock sample, during which the pore pressure was measured at two locations along the fault plane. In an inversion framework, we estimate the best model and the associated uncertainties of an effective diffusivity history that could explain the experimental data. Using this information, we could extend our hydro-mechanical model, which would allow the computation of pore pressure, diffusivity and slip changes along the experimental fault
Krayzel, Fabien. "Etude de phénomènes non-thermiques dans les amas d'étoiles jeunes : modélisation et analyse des données de H.E.S.S." Thesis, Grenoble, 2014. http://www.theses.fr/2014GRENY079.
More than one century ago, Victor Hess discovered the cosmical origin of the mysterious ionizing radiation. Yet, nowadays it still has a lot of secrets for us. Roughly below the PeV energy, the best candidates already proposed in 1934 were the supernovae remnants (SNR). These candidates still remain ; in the past we considered isolated SNRs, while today we rather think about SNRs inside big structures as superbubbles. These objects are formed by powerful stellar winds from massive stars combined with several SNRs gathered in a space of some decades or hundreds of parsecs. Observations show that the majority of the SNRs occurs in such regions. The point for us is to know if star clusters or associations of massive stars, not hosting any SNR, could also accelerate particles to very high energies and consequently emit gamma-rays.The gamma-ray astronomy is relevant in order to solve this type of riddle because the Very High Energy photons do not suffer of any deviation due to the Galactic magnetic field. It means that we can get informations from the source itself by detecting the gamma-ray radiation.In our study we assume that a part of the mechanical energy transferred to the interstellar medium can be used to accelerate charged particles, which will emit non-thermal radiations.First we assume a given injection spectrum (for electrons and/or protons), then we model the non-thermal emission expected considering particles losses.We deliver a catalogue of promising clusters and we rank them according to the expected strength of the gamma-ray flux.We conducted the analysis of H.E.S.S. data collected toward some selected clusters. The H.E.S.S. experiment is situated in Namibia and is the most efficient array of Cherenkov telescopes. We also used the Fermi-LAT public data. Fermi is a space-based telescope for High Energy gamma ray.Then we constrain our model with the obtained analysis results.The H.E.S.S. experiment had initially 4 telescopes in operation since 2003. In 2012, the second phase of the experiment started when a fifth larger one was added. We show here that it is relevant for this telescope to use a focus system in order to move the camera and change the distance camera-mirrors. The simulations show that the focus system leads to better performances (trigger rate, angular resolution)
Buffenoir-Billet, Kévin. "Étude chez l'Homme et l'animal des conséquences neuromécaniques du bloc moteur à la lidocaïne et comparaison chez l'Homme aux conséquences neuromécaniques de la neurotomie tibiale sélective." Compiègne, 2011. http://www.theses.fr/2011COMP1940.
This work presents a neuromechanical study of the action of lidocaine used in the production of an anesthetic block as part of the diagnostic evaluation of patients with spastic equinus foot disability. The originality of this work is to provide a quantitative assessment of these patients before treatment, using laboratory tools to measure the reflex excitability and the stiffness of the ankle plantar flexors. Clinical and neuromechanical tests were performed in spastic patients before and after soleus nerve block with lidocaine, and results (reduction of reflex hyperexcitability and excessive stiffness due to spasticity) were used to validate indication of a selective tibial neurotomy, after which patients were tested again at short and long terms. To better understand the effects of lidocaine on the neuromuscular system, a rat model of monitoring the effects of this molecule on the reflex excitability has been developed. This model has helped clarify the time course of lidocaine action on the H reflex in the rat. Moreover, to support the hypothesis that lidocaine acts more on the sensory component than on the motor component of the reflex pathway, the effects of lidocaine on the muscle spindle function were approached in the rat by an electroneurographical and mechanical analysis of spindle sensitivity
Augier, Benoit. "Etudes expérimentales de l'interaction fluide structure sur surface souple: application aux voiles de bateaux." Phd thesis, Université de Bretagne occidentale - Brest, 2012. http://tel.archives-ouvertes.fr/tel-00730669.
Kacem, Amine. "Étude expérimentale et numérique d'une nappe liquide en écoulement gravitaire." Thesis, Pau, 2017. http://www.theses.fr/2017PAUU3052/document.
In this thesis, unguided plane liquid sheets flowing vertically by gravity in an ambient air atmosphereare studied experimentally and numerically. First of all a litterature survey clearly identified themain issues regarding the dynamics and modelling of such flows. Subsequently, different liquids exhibitinga wide range of viscosity (1 to 50 times that of water) and a surface tension close to that of waterwere selected. The liquid flow regimes were characterized by a Reynolds number Rel ranging from afew units to a few thousand while the Weber number Wel was varied between 0.1 to 10. A dedicatedexperimental system was designed and operated to study the relevant sheet features (geometry, thickness)by means of an original optical method. In parallel, finite volume based 2D and 3D simulationsof the flows were undertaken. All rely on the volume of fluid method (VOF) combined with adaptivemeshing. The experimental and numerical sheets became shorter (vertically) and thinner as the massflow rate decreased. Experimentally, when the mass flow rate of the liquid becomes sufficiently low,liquid threads begin to appear next to a narrower sheet than before. In the case of water, this flowregime transition was preceded by the systematic appearance of holes in the lower part of the sheets.For the other more viscous Newtonian liquids (mixtures of water and glycerin), the appearance of theliquid threads was preceded by a destabilization of the rims which delimited the flat part of the sheets.The experimental study was then extended to fluids featuring more complex rheological behavior e.g.by the use of a non-Newtonian shear-thinning fluid. For such a fluid, it was shown that the criticalmass flow rate associated with the transition towards the threads regime was lower than its Newtoniancounterpart of similar viscosity. It is suggested that the presence of shear-thinning properties in liquidsheets may represent a solution for "coating" applications for which stable and non-pierced curtainsin flow configurations of low mass flow rates are targeted
Salameh, Georges. "Caractérisation expérimentale d’une turbine de suralimentation automobile et modélisation de ses courbes caractéristiques de fonctionnement." Thesis, Ecole centrale de Nantes, 2016. http://www.theses.fr/2016ECDN0006/document.
Engine downsizing is potentially one of the most effective strategies being explored to improve fuel economy and reduce emissions. In the field of turbocharging,simulation is limited by the operating characteristics of turbines supplied by the manufacturers. An accurate and precise extrapolation of the turbine performance maps is the main aim of this study. An experimental study was done on a radial turbine of a turbocharger with different techniques to measure the wider turbine performance map possible. Measurements were done on a classic turbocharger test bench with different turbine inlet temperatures. Then air was blown to the compressor inlet and exit: it is the compressor “gavage”. The compressor is then replaced with another one with are versed rotor: this compressor can help the turbine turn and even drive it itself. The lowest mass flow rates are measured even the negative ones. An electromechanical turbine test bench was developed but did not work correctly because of technical problems but future developments are promising. The various experimental techniques used allowed also the measurement of the turbine isentropic efficiency and the turbocharger mechanical efficiency. Finally, many extrapolation models of the turbine performance maps were tested and compared to the experimental results
Neidl, Romain. "Acétylation des histones au cours des processus de mémorisation : influence du vieillissement et de l'environnement enrichi." Thesis, Strasbourg, 2012. http://www.theses.fr/2012STRAJ087/document.
Hippocampal-dependent memory formation is associated with the establishment of specific genetic programs in the rat hippocampus. This transcriptional activation of genes involved in synaptic plasticity and memory processes, like bdnf, can in part be attributable to histone acetylation-related mechanisms, allowing dynamic chromatin structure changes. Our results indicate a specific and differential regulation of histone acetylation in young rodents hippocampus depending on the nature of the stimuli. In fact, H2B and H4 acetylations are specific to rats having learnt a task (MWM, CFC), whereas H3 acetylation seems to be more sensitive to the environmental context. Besides, it is known that ageing and environmental enrichment (EE) are factors able to modulate histone acetylation, leading respectively to repression and activation of memory-related genetic programs. Here, we showed that an EE of 6 months, even applied to 18 month-old rats, which already present memory deficits, is able to induce persistent chromatin structure modifications through H3. By favoring the expression of genes as bdnf, these changes could participate in the preservation of memory abilities, which are normally lost in 24 month-old rats. The precise identification of regulating elements located on the bdnf promoter brings new data about the potential factors involved in the transcriptional response following EE, e.g. CREB and NFκB. Altogether, our results confirm the role of histone acetylation in memory processes and underline that these regulations remain flexible during life, thus highlighting possible therapeutic strategies in pathological ageing conditions
Minissale, Marco. "Physique et Chimie sur la surface de la poussière interstellaire : effet de la diffusion des atomes d’oxygène et de la désorption chimique sur le réseau chimique H-C-N-O." Thesis, Cergy-Pontoise, 2014. http://www.theses.fr/2014CERG0721/document.
The interstellar medium is the matter that exists in the space between the star systems in a galaxy. It is composed of gas and elongated tiny dust grains. To date, plenty of molecules (> 170) are known to exist in the interstellar medium. The presence of most of them can be understood in terms of gas phase reactions but the synthesis of some key species (H2, H2O, CO2) need the intervention of solid-state reactions on dust grains surface. The aims of this thesis are to understand what are the relevant physical-chemical processes (i.e., diffusion and desorption) occurring on the surface of interstellar dust grains and how these processes influence synthesis of more and more complex molecules. In particular, the focus of my thesis is the investigation of:1) the role of O-atom diffusion and the oxidation processes in the formation of interstellar ices;2) the thermal and non-thermal processes coupling gas and solid phase.The reasons of these investigations lie on the realization that, up to now, only hydrogen diffusion and hydrogenation reactions are commonly considered in solid astrochemistry and the role of oxygenation as well as the importance of adsorption and desorption processes are often disregarded.Evidently, a better knowledge of such physical-chemical processes and, in general, of the solid state physical-chemistry could help astronomers to understand the formation of interstellar ices, the increase on molecular complexity, and the equilibrium between gas and solid phase.To answer these questions, many experiments have been performed with the FORMOLISM set-up, i.e., FORmation of MOLecules in the ISM, located in the Universitè de Cergy Pontoise, Observatoire de Paris. Via two triply differentially pumped beams, atoms and molecules were aimed at a cold (>6.5 K) sample held in a Ultra high vacuum chamber. The products were probed using Mass spectroscopy and Reflexion Absorption Infrared Spectroscopy.To simulate different astrophysical environments, the solid state physical-chemistry has been studied in different experimental conditions:-The substrate morphology (Amorphous water ice, porous (p) and compact (np), crystalline (c) ice, amorphous silicate, and graphite)-The species deposited and their relative ratio-The coverage of deposited species, from 0.1 to 2 ML-The substrate temperature, from 6.5 to 60 KConcerning oxidation processes and O-atom reactivity, the results show that oxygen is very reactive with many species (i.e., H, CO, NO, H2CO, HCOOH); O diffusion appears to be much faster than previously expected and can occur via quantum mechanical tunnelling at temperatures as low as 6.5 K. We compared the experimental values of the diffusion coefficients and found that the rates of diffusion on each surface, based on modelling results, were considerably higher than those expected for heavy atoms such as oxygen. Our findings show that O atoms can scan any available reaction partners (e.g., either another H atom, if available, or a surface radical like O, OH, CO) at a faster rate than that of accretion. In particular, in very dense interstellar clouds, the O/H ratio is such that O becomes one of the dominant reactive partners together with H. This has an impact on the chemistry occurring at the surface of dust grains as either the formation of some species may be enhanced, or at least the relative abundances of the final products will be affected. An important example of how O-atom mobility can modulate the abundances of key species of ices in the ISM is the case of the H2O/CO2 ratio via the CO+O and H2CO+O pathways.Concerning gas-solid coupling processes (i.e., adsorption, sticking, thermal desorption, chemical desorption), the results show that each processes is influenced in a different way by the substrate (i.e., water ice, silicate or graphite). Moreover, we provide a useful list of binding energies of several species and chemical desorption efficiency for different reactions on different subst
Loureiro, Michaël. "Implication de l'hippocampe ventral et des noyaux reuniens et rhomboïde du thalamus dans les processus cognitifs sous-tendant la mémoire spatiale chez le Rat." Phd thesis, Université de Strasbourg, 2012. http://tel.archives-ouvertes.fr/tel-00813293.
Kiss, Agneta Kristina. "Mise en place d'outils analytiques et chimiométriques pour les études métabonomiques de matrices biologiques complexes par Spectrométrie de Masse Haute-Résolution." Thesis, Lyon 1, 2014. http://www.theses.fr/2014LYO10125.
My research work highlights the development of a metabonomic strategy through two topical issues: the doping in sport (Part A) and the Exposome (Part B). The first part includes two studies and aims to assess the contribution of metabonomics to the development of new screening tools. During these studies, I focused on the non-targeted analysis of clean and doped urine samples provided by the French Anti-Doping Agency and by volunteers. The originality of this approach lies in its non-targeted nature and, particularly, in its ability to highlight metabolic disruptions by (i) high-resolution (ToF) and very high-resolution (FT ICR) mass spectrometry and (ii) the analysis of multivariate data. The implemented strategy revealed several potential biomarkers for the use of tetrahydrocannabinol, budesonide and salbutamol. The second part of this thesis aims to evaluate the impact of vinclozolin on the hormonal system of rats and thus meets the requirements of the new regulations. For this study, I focused on testes extracts coming from rats treated with vinclozolin. Due to its comprehensive nature, the metabonomic study provided additional information to the previous targeted approach. All these results highlight the contributions and the limitations of metabonomics with regard to: (1) the choice and the preparation of biological samples, (2) the advantages and disadvantages of different analytical techniques, (3) the opportunities in terms of data processing, (4) the statistical requirements and (5) the biological value of the results
Jacobs, Bidhan. "Vers une esthétique du signal. Dynamiques du flou et libérations du code dans les arts filmiques (1990-2010)." Thesis, Paris 3, 2014. http://www.theses.fr/2014PA030089.
During the 90s, with the introduction, then accelerated expansion of digital by the technical industries, has promoted the development of a spontaneous and collective critical current on the signal in the filmic arts. We develop a history of technics and critical aesthetic forms of signal, in beam segments, according to a taxinomy that extends the 70s’ materiologic structuralism (Malcolm le Grice, Peter Gidal, Paul Sharits, Anthony McCall). This history embrace film, video and digital, to reorganize our different conceptions of these fields according to the scientific viewpoint (which detection, codification and display of the signal depend on). We propose a backward technological history from the viewpoint of the signal computation, a systematic process common to all filmic technologies, and understood as a set of operating rules specific to computational data processing.In the double tradition, first of Jean Epstein, Marcel L'Herbier or Jean Renoir, on the other hand experimental structuralism (Paul Sharits, Malcolm Le Grice...), many contemporary artists such as Paolo Gioli, Philippe Grandrieux Peter Tscherkassky, Marylène Negro, Leighton Pierce, Augustin Gimel, Jacques Perconte or HC Gilje (just to mention a few) has developed a signal intelligence thanks to two simultaneous critical enterprises. The first, on the register of the apparatus, challenges the programming technology and aims the liberation of the code ; the second, on the register of the image, challenges the norms of the visuality and expand the visual and sound palettes of blur. We try to formulate and organize the logics which, crossing and determining the diversity of artistic initiatives whom we observe specificities and singularities, belong to the same artistic battle against standardization
Binti, Saharin Sanisah. "Vaporization and autoignition characteristics of ethanol and 1-propanol droplets : influence of water." Phd thesis, Université de Bourgogne, 2013. http://tel.archives-ouvertes.fr/tel-00909646.
Ali, Mohamad. "Effet de l'enrichissement physique et social sur l'établissement d'un souvenir spatial à long terme après lésion des noyaux reuniens et rhomboïde du thalamus chez le rat." Thesis, Strasbourg, 2015. http://www.theses.fr/2015STRAJ054/document.
Recent studies have shown the key role of the ventral midline thalamus (Reuniens and Rhomboid nuclei; ReRh) in spatial memory persistence in rats, which requires a hippocampo- prefrontal dialogue for consolidation at the systems-level. As enriched environment (EE) promotes the recovery of declarative-like memories after diencephalic (anterior thalamus) lesion, and enhances neuronal plasticity, we tested its impact on the effects of the ReRh lesion upon the consolidation/retrieval of a remote spatial memory in a Morris water maze (i.e. 25 post-acquisition days). For this purpose, we exposed rats for 40 days to an enriched environment beginning 2 weeks after fiber-sparing excitotoxic thalamic lesions. In addition, the expression of the immediate early gene, c-fos, was mapped by immunohistochemistry as a marker of functional activity in the dorsal hippocampus, the median prefrontal cortex (mPFC), the intralaminar thalamic nuclei and the amygdala. Enriched housing allows the recovery of spatial memory persistence capacities in ReRh rats, with additional beneficial effects on anxiety and habituation to a novel environment. Immunohistochemistry of the Fos protein showed a higher recruitment of the mPFC, concomitant with memory capacities recovery in enriched ReRh rats, while in standard ReRh rats, Fos expression in the mPFC was significantly decreased together with the alteration of memory performance. The lesion-induced amygdala hyperactivity in basal and memory conditions was significantly attenuated in the ReRh enriched group. We suggested that amygdala might be involved in the effect of ReRh lesion on memory persistence, and also in the functional recovery associated with the restoration of the mPFC activity during remote memory retrieval in enriched ReRh rats
Hirsch, Pierro. "The relationship between markers of risk-taking tendecies and the first year driving records of young drivers." Thèse, 2005. http://hdl.handle.net/1866/17774.
Abas, Khalil. "Optimisation des marais filtrants pour l’abattement du pesticide chlorantraniliprole du ruissellement agricole." Thesis, 2021. http://hdl.handle.net/1866/25622.
Over the past decades, a wide variety of emergent pesticides, such as chlorantraniliprole (CAP), have been introduced despite the lack of in-depth knowledge of their ecotoxicological risk. Treatment wetlands (TWs) are environmentally friendly and sustainable technologies that have shown great potential to mitigate common agricultural pollutants, such as pesticides in runoff. The objective of this study was to optimize the use of the horizontal subsurface flow treatment wetlands (HSSF TWs) by determining a) the effect of biochar amendment to the substrate and b) the performance of three species of macrophytes (Phragmites australis subsp. americanus, Scirpus cyperinus and Sporobolus michauxianus) in CAP removal from agricultural runoff. The removal efficiency was calculated using the mass balance method in mature HSSF mesocosms fed with synthetic agricultural runoff containing CAP for a period of one month. Mesocosms with the addition of biochar were very effective in removing CAP (90-99%) and remained so throughout the experimental period. This efficiency is likely due to the high adsorption capacity of biochar, although this mechanism has not been directly measured. In contrast, CAP removal in mesocosms planted without biochar was low and limited and there was no difference between species, although there were differences in their above-ground biomass and their evapotranspiration (ET) rate. However, the planted mesocosms acted as buffer zones, reducing the CAP mass of the influent and slowly releasing it into the discharge. The ET rate of S. cyperinus and P. australis was higher than that of S. michauxianus, resulting in a better buffering effect. This study suggests that adding biochar to the HSSF TW substrate is promising for CAP attenuation in agricultural runoff, but their long-term effectiveness remains to be investigated. Nevertheless, TWs should be used as a complementary tool, as part of wider actions aimed at reducing the pressure of pollutants on aquatic ecosystems.