Tesis sobre el tema "Microgravity effects"
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Pardo, Steven Javier. "Effects of simulated microgravity on preosteoblast gene expression". Thesis, Available online, Georgia Institute of Technology, 2004:, 2004. http://etd.gatech.edu/theses/available/etd-06072004-131314/unrestricted/pardo%5Fsteven%5Fj%5F200405%5Fms.pdf.
Texto completoAnderson, Rebecca K. "Effects of simulated microgravity and shear on cell behavior". [Gainesville, Fla.] : University of Florida, 2004. http://purl.fcla.edu/fcla/etd/UFE0004284.
Texto completoPoniatowski, Adam F. "Effects of simulated microgravity on human umbilical cord blood hematopoietic stem cells". [Gainesville, Fla.] : University of Florida, 2004. http://purl.fcla.edu/fcla/etd/UFE0008840.
Texto completoFarmer, Brandon. "Effects of Microgravity on Mucin Production in the Urinary Bladder in Mice". Digital Commons @ East Tennessee State University, 2012. https://dc.etsu.edu/honors/137.
Texto completoKopp, Sascha [Verfasser]. "The effects of real and simulated microgravity on human cancer cells / Sascha Kopp". Magdeburg : Universitätsbibliothek, 2018. http://d-nb.info/1170777368/34.
Texto completoEvetts, Simon Nicholas. "Human cardiovascular baroreceptor function and blood pressure control : effects of aerobic fitness and microgravity". Thesis, King's College London (University of London), 2001. https://kclpure.kcl.ac.uk/portal/en/theses/human-cardiovascular-baroreceptor-function-and-blood-pressure-control--effects-of-aerobic-fitness-and-microgravity(13def2f6-128a-45a4-aaf8-c3cc0bf65268).html.
Texto completoGhaderi, Yeganeh Mohammad. "Effects of preheated combustion air on laminar coflow diffusion flames under normal and microgravity conditions". College Park, Md. : University of Maryland, 2005. http://hdl.handle.net/1903/2960.
Texto completoThesis research directed by: Mechanical Engineering. Title from t.p. of PDF. Includes bibliographical references. Published by UMI Dissertation Services, Ann Arbor, Mich. Also available in paper.
Rosado, Helena Isabel Venancio. "Effects of simulated microgravity on the virulence properties of the opportunistic bacterial pathogen Staphylococcus aureus". Thesis, University College London (University of London), 2009. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.515067.
Texto completoWoods, Chris Cory. "The effects of actual microgravity and vector-averaged gravity on the development of T cells". Diss., The University of Arizona, 2004. http://hdl.handle.net/10150/290092.
Texto completoMunro, Troy. "Heater Geometry and Heat Flux Effects On Subcooled, Thin Wire, Nucleate Pool Boiling In Microgravity". DigitalCommons@USU, 2012. https://digitalcommons.usu.edu/etd/1235.
Texto completoCavin, Kaylyn y Allan Forsman. "The Effects of Simulated Space Flight on Ovarian Tissue". Digital Commons @ East Tennessee State University, 2019. https://dc.etsu.edu/asrf/2019/schedule/115.
Texto completoJung, Song-Yi. "Effects of culture methods and simulated microgravity conditions on development of bovine embryos produced in vitro". Master's thesis, Mississippi State : Mississippi State University, 2008. http://library.msstate.edu/etd/show.asp?etd=etd-11052008-160050.
Texto completoAl-Hasawi, Nouf. "The effects of microgravity cell culture on extracellular matrix expression, islet remodelling, and insulin secretory function". Thesis, University of Brighton, 2016. https://research.brighton.ac.uk/en/studentTheses/c063fa9b-59ba-4a1f-8e28-bb4af9339052.
Texto completoCarvil, Philip Alexander Thomas. "Axial loading as a countermeasure to microgravity-induced deconditioning : effects on the spine and its associated structures". Thesis, King's College London (University of London), 2017. https://kclpure.kcl.ac.uk/portal/en/theses/axial-loading-as-a-countermeasure-to-microgravityinduced-deconditioning-effects-on-the-spine-and-its-associated-structures(062445f3-4c6d-4e2a-8d20-167798f8c533).html.
Texto completoWhite, Grayson D., Xiao W. Mao, Michael J. Pecaut, Nina C. Nishiyama, Mary Campbell-Beachler y Allan D. Forsman. "The Effects of Simulated Spaceflight Conditions on the Mucin Lining of the Mouse Uterine Tube". Digital Commons @ East Tennessee State University, 2018. https://dc.etsu.edu/asrf/2018/schedule/48.
Texto completoAde, Carl J. "Effects of supine and -6° head-down tilt posture on cardiovascular and exercise performance". Thesis, Kansas State University, 2008. http://hdl.handle.net/2097/1041.
Texto completoDepartment of Kinesiology
Thomas J. Barstow
Background and Aim: Long-term microgravity exposure, via spaceflight or -6° head-down tilt bedrest, has been shown to produce significant cardiovascular deconditioning and decreases in exercise performance. However, there is little known about how acute microgravity exposure influences the cardiovascular system’s ability to adjust to increases in physical work. Therefore, the aim of this study was to compare cardiovascular and exercise performance during acute upright, supine and -6° head-down tilt positions. Methods: Seven healthy inactive men performed maximal cycle exercise (VO2peak) tests in the upright, supine, and -6° head-down tilt on separate days. Oxygen consumption and heart rate were measured continuously throughout the testing procedures. Cardiac output (acetylene exhalation technique) was measured periodically and interpolated to the 100-watt work rate. Stroke volume was calculated from cardiac output and heart rate data. Results: Peak oxygen uptake and heart rate were significantly decreased in the supine and -6° head-down tilt positions compared to the upright (VO2peak 2.01±0.46, 2.01±0.51 versus 2.32±0.61 L/min respectively; peak heart rate 161±13, 160±14 versus 172±11 bmp). However, cardiac output at 100-watts was similar in all three-exercise positions. Calculated stroke volume at 100-watts was significantly higher in the -6° head-down tilt position compared to the upright position (76.6±4.7 versus 71.2±4.5, ml). Conclusion: These results suggest that exercise capacity is immediately decreased upon exposure to a microgravity environment, prior to any cardiovascular deconditioning. Therefore, an astronaut’s exercise performance should be evaluated with exercise tests in the -6° head-down tilt position prior to space flight in order to establish a baseline response.
Trappe, Todd A. "Skeletal muscle and cardiorespiratory responses to simulated microgravity". Virtual Press, 1996. http://liblink.bsu.edu/uhtbin/catkey/1018783.
Texto completoHuman Performance Laboratory
Greaves, Danielle Kathleen. "Désadaptations cardiovasculaires à la microgravité : techniques avancées pour améliorer la mesure et l'évaluation du risque cardiovaculaire induit par les vols spatiaux pour les équipages de longue durée Effects of exercise countermeasure on myocardial contractility measured by 4D speckle tracking during a 21-day head-down bed rest Cardiac and arterial structure and functional changes after four days of dry immersion with and without thigh cuffs Effect of thigh cuff on venous flow redistribution during 4 days in dry immersion". Thesis, Normandie, 2019. http://www.theses.fr/2019NORMC433.
Texto completoObjective: to evaluate functional myocardial contractility after 21 days of head-down bed rest (HDTBR) in sedentary control (CON) or with a resistive vibration exercise (RVE) countermeasure (CM) applied, by using 4D echocardiographic (4D Echo) imaging and speckle tracking strain quantification.Methods: Twelve volunteers were enrolled in a crossover HDTBR design, and 4D Echo was performed in supine position (REST) at BDC-2 and at R+2, and in -6° HDTBR (on day 18), and also during the first and the last minute of the 80° head-up step of Standard Measures tilt test, performed at both BDC-2 and R+2. Radial (Rad-Str), longitudinal (Lg-Str) and twist (Tw-Str) strain were measured by 4D speckle tracking, as well as left ventricle diastolic volume (LVDV) and mass (LVmass).Results: On day 18: in the CON group, LVDV and LVmass were reduced (p<0.05), the Rad-Str decreased (p<0.05) and Tw-Str showed a tendency to increase (p< 0.11), with no changes in Lg-Str. In RVE group, LVDV and LV mass, as well as all the strain parameters remained unchanged.On R+2: in the CON group, LVDV and LVmass were not recovered in all subjects compared to pre-HDTBR (p<0.08), Rad-Str was still decreased (p<0.05), while Tw-Str tended to increase (p<0.09). These parameters remained unchanged in the RVE group.Tilt 80°: Rad-Str and Lg-Str values at 80° tilt were similar post HDT in both groups.Conclusion: 4D Echo and speckle tracking analysis showed that in the CON group, Rad-Str decreased concomitant with LVmass and LVDV with HDTBR, but this observation did not support the hypothesis that this HDTBR induced remodelling or a muscle atrophy. RVE acted to preserve both LVmass, LVDV and contractility during HDTBR, thus proving its effectiveness to this aim. Nevertheless, the significant HDTBR-induced changes observed in the CON group had only a limited effect on the cardiac contractile response as observed during post HDTBR tilt test. The level of contractility at 80° Tilt position was not affected neither by HDTBR nor by RVE CM.Purpose: The objective was to quantify the venous redistribution during a 4-day dry immersion (DI) and evaluate the effect of thigh cuffs.Methods: The study included 9 control (Co) and 9 subjects wearing thigh cuffs during daytime hours (CU). Ultrasound images were collected Pre DI, on the fourth day in the morning (D4 AM) and on the fourth day in the afternoon (D4 PM), to assess the following outcome variables: left ventricle dimension, stroke volume, and ejection fraction (LVD, SV, EF), jugular vein volume (JV), portal vein dimension (PV), middle cerebral vein velocity (MCVv). An additional measure of JV dimension was performed on the first day after having worn the cuffs for two hours (D1 2H).Results: The JV volume increased significantly from Pre to D1 2H in both groups, but increased more in the Co compare to the CU subjects (Co: 0,27+/0.15cm3 to 0.94+/-0;22 cm3;P<0.01 CU: 0,32+/-0.13 cm3 to 0.64+/-0.32 cm3 P<0.042).At D4 AM no difference was found between the two treatment groups for any of the parameters listed above.Stroke volume and EF decreased from Pre (SV:111+/-23cm3 to 93+/-24 cm3 p<0.05; EF:0.66+/-0.07 to 0.62+/-0.07 p<0.05). JV volume was slightly, but significantly increased (Co: 0.47+/-0.22cm3 CU:0.35+/-014cm3 P<0.05), while MCVv and PV remained unchanged from Pre DI. From D4 AM to PM these parameters did not show any significant change.Conclusion: The results confirm that DI induces, during the first 2-3 h, a significant cephalic fluid shift as observed in spaceflight. During this early phase the thigh cuffs reduced the amplitude of the fluid shift towards the head, but after 4 days in DI there was only a slight memory (residual) effect of DI on the jugular volume and no residual effect of thigh cuffs
Provost, Romain. "Adaptation cardiovasculaire de l'astronaute : en confinement et en microgravité réelle et simulée". Thesis, Tours, 2015. http://www.theses.fr/2015TOUR3307/document.
Texto completoThis PhD work focuses on astronaut cardiovascular adaptation and deconditioning in real prolonged microgravity, short simulated microgravity (with and without countermeasures) and long-term confinement. To answer to this topic 3 humans experimental studies have been performed, and thus the present PhD work is divided into 3 distinct parts . The first one is the mission « Mars 500 » which consists in 520-days confinement with 6 subjects-volunteers mission. The second is the project « Vessel Imaging » whitch consit in a 6-months spaceflight aboard the « International Space Station » with 10 subjects-astronauts. The third is the « Short Time Bed -Rest (STBR) » study (12 subjects) which consist in a short period of bedrest (-6°, 5 days) with and without the use of two cardiovascular countermeasures by hypergravity (continuous or intermittent)
Rudwill, Floriane. "Conséquences d’une simulation d’impesanteur de 21 jours chez l’homme sur le métabolisme des lipides et effets d’une supplémentation en protéines testée comme contremesure". Thesis, Strasbourg, 2015. http://www.theses.fr/2015STRAJ009/document.
Texto completoDuring 21 days of simulated microgravity, the development of several metabolic alterations has been studied: a low-grade inflammation and an alteration of insulin sensitivity and lipid metabolism. Known for their positive effect on metabolism, whey proteins supplementation combined with alkaline salts have also been tested. At the opposite of previous studies, no inflammation, nor lipid metabolism alterations have clearly been described. Nevertheless, a decrease in carbohydrates oxidation in favor of lipids is observed, suggesting the development of insulin insensitivity. Our data suggest that it may be possible to prevent the metabolic disorders associated with severe physical inactivity by anisocaloric replacement of lipids by proteins in the diet, along with a protein intake of 1.2g/kg/day and tight control of energy balance by adjusting energy intake
Fareh, Jeannette. "Peptide atrial natriurétique et noradrénaline centrale et périphérique après une microgravité simulée de 9 jours chez le rat : comparaison avec une microgravité réelle (vol SLS-1)". Lyon 1, 1993. http://www.theses.fr/1993LYO1T211.
Texto completoChabeauti, Pierre-yves. "Adaptation des représentations internes de l’action à la microgravité : continuum fonctionnel de la perception à l’exécution". Thesis, Aix-Marseille, 2012. http://www.theses.fr/2012AIXM4730/document.
Texto completoWhat is the role of gravity in the internal representations of action? Beyond the constraints of balance, does the gravity vector influence the action globally, up to the perception of our peers' movement? These issues have guided my thesis work. The originality of our approach was to place the execution and the perception of action in a "functional continuum" built around the internal representations of the action. To do this, the tool of choice, that is common to all three experiments presented here, is microgravity (0G). The experiments of this thesis showed that the internal representations of action are fed with graviceptive information to build and adapt constantly. However, under certain conditions such as short-term 0G, an order of priority appears. Indeed, the CNS is able to implement immediate and effective solutions, as we demonstrate it with the fast sensorial reweighting observed during a postural orientation task. However, a lag is observed in the recalibration of internal models based on sensory inputs severely disrupted. This is what we have shown through a protocol of motor imagery, showing a loss of isochrony between executed and imagined movements under 0G. Finally, we have demonstrated in subjects without any experience of microgravity, that the perception of human movement is effective even when it is performed in weightlessness, although different cerebral networks are involved
Damiot, Anthony. "Effet d'une contremesure nutritionnelle sur l'inflexibilité métabolique induite par simulation d'impesanteur chez l'homme". Thesis, Strasbourg, 2018. http://www.theses.fr/2018STRAJ124/document.
Texto completoSpace missions and bedrest simulation studies have shown that physical inactivity affects all physiological systems in humans. In prolonged bed rest conditions, our laboratory (UMR7178, IPHC, DEPE, Strasbourg) showed that metabolic adaptations were close to that found in the metabolic syndrome associated with metabolic chronic diseases in the general population. Based on these results, we proposed a hypothesis to describe the cascade of events leading to metabolic alterations in simulated microgravity, leading to the development of metabolic inflexibility. Metabolic inflexibility is defined as the inability of the body to adjust fuel use to changes in fuel availability. The first objective of this Thesis was to test this hypothesis and understand the mechanisms underlying the simulated microgravity induced metabolic alterations. Specifically, we focused on characterizing the metabolic inflexibility syndrome in humans through clinical investigation of muscle condition, inflammation and oxidative stress, insulin sensitivity and oxidation of energy substrates in a proof of concept study and a 60-day microgravity simulation study in healthy male adults. Based on recent studies demonstrating the impact of nutritional supplements on metabolic adaptations associated with many chronic metabolic diseases, a proof-of-concept study tested the efficacy of a nutritional cocktail composed of polyphenols, omega-3, vitamin E and selenium. In the feasibility study, we showed that supplementation reduced muscle atrophy, oxidative stress and the development of metabolic inflexibility via an improvement in lipid oxidation and a reduction in de novo lipogenesis following a 20-day period of physical inactivity induced by daily step reduction. Based on these first results, a 60-day bed rest study was conducted in health men to test the effects of the dietary cocktail in simulated microgravity conditions. In this second human clinical research study, nutritional supplementation prevented at least partially acute and chronic adaptations caused by physical inactivity induced by bed rest. In particular, supplementation increased antioxidant blood defenses, prevented increased lipid levels, reduced lipid oxidation and mitigated the development of acute and chronic metabolic inflexibility in absence of metabolic challenge. However, the countermeasure did not have a protective effect following a metabolic challenge in the form of carbohydrate overnutrition. All the results indicate that the development of metabolic inflexibility appears to be an early event, which, if detected in time, could prove to be a useful biomarker to use to prevent chronic diseases in the 21st century. Moreover, this study demonstrated the advantage of an antioxidant and anti-inflammatory cocktail by limiting metabolic alterations without having harmful effects on other systems, while being easy to implement and cost-effective. Even if the nutritional countermeasure used in this study is not sufficient to keep all physiological systems intact, further studies will have to be carried out to find the ideal combination of countermeasures to limit microgravity-induced degradation and thus allow new advances in space exploration (Moon, Mars) over the next decades. In this line, an adapted protocol of physical activity combined with a nutritional countermeasure in the form of a cocktail could be a promising approach
Germain, Philippe. "Effets d'une microgravité simulée sur le système neuromusculaire : approche prohylactique". Aix-Marseille 2, 1994. http://www.theses.fr/1994AIX22056.
Texto completoJeandel, Jérémy. "Effets de stress associés aux vols spatiaux sur le système du complément et les cellules dendritiques". Thesis, Université de Lorraine, 2019. http://docnum.univ-lorraine.fr/ulprive/DDOC_T_2019_0198_JEANDEL.pdf.
Texto completoDuring spaceflights, astronauts encounter numerous stresses leading to immune system impairment. Given the scarcity of space missions, simulation models are used on Earth to study the effects of spaceflight-associated stresses on the immune system. The aim of this thesis was to study the effects of spaceflight-associated stresses on the complement system and on dendritic cells (DC). First, we studied the effects of individual or combined spaceflight-associated stresses on the C3 molecule expression in amphibians and mice. We showed that some of these stresses such as microgravity increased the C3 complement expression in P. waltl larvae but no variation were found in mice subjected to simulated microgravity (hindlimb unloading model). We also studied the effects of simulated microgravity by RPM on murine DC phenotype and function. We showed that RPM exposure impaired both DC actin cytoskeleton and survival. Moreover, DC exposed to simulated microgravity showed an immature phenotype characterized by a decrease of co-stimulation molecule expression and pro-inflammatory cytokines secretion, which are essentials for DC functions. However, these numerous alterations did not affect antigen presentation to T cells. Taken together, these results highlight the significant effects of spaceflight-associated stresses on the immune system. Studying microgravity will allow to better understand its effects on health and to develop adapted countermeasures
VanDerWege, Brad A. (Brad Alan). "Effect of bromotrifluoromethane and trifluoromethane on laminar jet diffusion flames in normal and microgravity". Thesis, Massachusetts Institute of Technology, 1996. http://hdl.handle.net/1721.1/39747.
Texto completoDesplanches, Dominique. "Capacité aérobie et adaptabilité musculaire squelettique chez le rat : effets d'une microgravité simulée ou réelle : pouvoir de récupération". Lyon 1, 1987. http://www.theses.fr/1987LYO1T080.
Texto completoLehmann, Peter. "Controle de la solidification par effet Seebeck". Grenoble INPG, 1996. http://www.theses.fr/1996INPG0098.
Texto completoFERREIRO, PATRICK. "Effets de la lower body negative pressure sur le syndrome de deconditionnement cardio-vasculaire lie a la microgravite". Toulouse 3, 1989. http://www.theses.fr/1989TOU31225.
Texto completoDavet, Julien. "Modifications structurales et moléculaires des plexus choroïdes et du système natriurétique, lors de l'adaptation à la microgravité chez le rat". Lyon 1, 1997. http://www.theses.fr/1997LYO10330.
Texto completoCrandall, Craig G. (Craig Gerald). "Alterations in Human Baroreceptor Reflex Regulation of Blood Pressure Following 15 Days of Simulated Microgravity Exposure". Thesis, University of North Texas, 1993. https://digital.library.unt.edu/ark:/67531/metadc278142/.
Texto completoDmitrieva, Liubov. "Dysfonctions neuromusculaires et cardiovasculaires dans les troubles posturaux orthostatiques induits par la microgravité". Thesis, Angers, 2018. http://www.theses.fr/2018ANGE0058/document.
Texto completoPostural and orthostatic impairment are both acknowledged consequences of spaceflight. One of the factors for orthostatic and postural stability is muscle tone, which decreases within the onset of microgravity. Studies of cardiovascular, neuromuscular and postural effects of microgravity are numerous ; yet the role of neuromuscular and vascular disorders in orthostatic and postural impairment remains unclear. We aimed to investigate vascular and neuromuscular alterations induced by microgravity, as well as their relationships. We studied healthy men exposed to 6-mo spaceflight, 21-day head-down bedrest and 3-to 5-day dry immersion. These conditions differ by the level of support unloading. Cardiovascular state was assessed by orthostatic tests, neuromuscular - by myotonometry, postural stability - by stabilometry. We found that long-term spaceflight induced much deeper disorders than relatively short-term modeled microgravity. Furthermore, immersion induced more severe disorders than bedrest, despite its shorter duration. Our data, along with literature, suggest that it is the support unloading that defines the depth of disturbances. The leading role in development of postural disorders under gravitational unloading belongs to decrease in postural muscle tone. This decrease occurs mainly by a reflex mechanism (decrease in support afferentation). It might be responsible for orthostatic impairment - via decrease in the efficiency of muscle pump promoting venous return, and for postural impairment - via increase in recruitment thresholds of postural motoneurons
Jung, Song-Yi. "EFFECT OF CULTURE METHODS AND SIMULATED MICROGRAVITY CONDITIONS ON DEVELOPMENT OF BOVINE EMBRYOS PRODUCED IN VITRO". MSSTATE, 2008. http://sun.library.msstate.edu/ETD-db/theses/available/etd-11052008-160050/.
Texto completoMartirosyan, Arayik [Verfasser] y Christian [Akademischer Betreuer] Betzel. "Effect of macromolecular mass transport in microgravity vs 1G protein crystallization / Arayik Martirosyan ; Betreuer: Christian Betzel". Hamburg : Staats- und Universitätsbibliothek Hamburg, 2019. http://d-nb.info/1200548116/34.
Texto completoHérault, Stéphane. "Adaptations du système cardio-vasculaire en microgravité réelle et simulée : influences d'une contre-mesure : les bracelets". Tours, 2000. http://www.theses.fr/2000TOUR3305.
Texto completoTreffel, Loïc. "Dysfonctions vertébrales et posturales après simulations de la microgravité". Thesis, Strasbourg, 2017. http://www.theses.fr/2017STRAJ111/document.
Texto completoThis work focuses on the study of back pain experienced by astronauts, who present with a greater incidence of herniated discs compared to a control population. Our research aims at understanding the physiopathology of this phenomenon and to study the clinical consequences of vertebral deconditioning which also contributes to postural disorders. This line of research has been recommended by the various international space agencies. For this reason, we had the opportunity to analyze data in two models simulating the effects of microgravity: dry immersion (n = 11) and head-down bed rest (n = 9), and a similar state, confinement (n = 4). Only the main results of dry immersion, a new method of studying our paradigm, are reported in this summary. Using magnetic resonance imaging and spectroscopy of the vertebral column, it was possible to analyze the intervertebral disc in 3 dimensions and to objectify the increase in water content (+ 17%) and the increase in intervertebral disc volume (+ 9.5%). Variations in paravertebral and lower limb muscle tone were measured with the very recent, and non-invasive, MyotonPRO technology. A decrease in muscle tone (-7.3%) was found to be associated with muscular atrophy (-10.6%) as well as a loss of strength in the lower limbs. These results, attesting to muscle deconditioning, are consistent with postural impairment immediately after dry immersion. We also studied variations in dental occlusion, which is involved with the maintenance of posture and could affect balance. In summary, two elements are involved in the explanation of vertebral dysfunction: the increase in spine height, related to increased intervertebral discs volume and paravertebral muscles atrophy, which plays a major role in posture. However, we also showed a role of dental occlusion in vertebral and postural deconditioning. In conclusion: muscle tone, good vertebral mobility, and dental occlusion are elements to be preserve during and after an exposure to weightlessness to avoid the deleterious effects of deconditioning
Lafouissi-Elkhadiri, Rabia. "Retentissement de différents types d'environnements extrêmes (stress et microgravité simulée) sur le comportement en open-field et sur l'aminotransférase de la tyrosine chez le rat Wistar". Lyon 1, 1995. http://www.theses.fr/1995LYO10145.
Texto completoFRAYSSE, BODVAEL. "Effets myotrophiques d'un facteur neurotrophique, le cntf, sur les muscles squelettiques de rat en conditions de microgravite simulee". Nantes, 2000. http://www.theses.fr/2000NANT2057.
Texto completoMaillet, Alain. "Comparaison des effets endocriniens, métaboliques et cardio-vasculaires observés lors d'expériences d'alitement anti-orthostatique et de confinement". Lyon 1, 1997. http://www.theses.fr/1997LYO1T243.
Texto completoGaignier, Fanny. "Modulation de l'immunité adaptative murine par la micropesanteur simulée, l'hypergravité ou les stress chroniques ultra légers". Thesis, Université de Lorraine, 2014. http://www.theses.fr/2014LORR0171/document.
Texto completoSpaceflight weaken the immune system. The aims of this thesis were to determine the effects of exposure to simulated microgravity, hypergravity or chronic ultra-Mild stress on murine humoral immunity, using ground-Based models. We were able to show that the anti-Orthostatic suspension, that mimics some of the effects of microgravity, caused a 59% decrease of the number of splenic B cells and an inversion of the ratio between B and T lymphocytes. A decrease in B lymphopoiesis, as evidenced by the decrease of lymphoid progenitors and pre-B cells is likely the cause. Furthermore, we showed that the anti-Orthostatic position, in the absence of stress, leads to a decreased in vitro response of B cells to LPS, more important than the one of T cells to ConA, as did hypergravity exposure. To determine the mechanisms responsible of the decreased response of B cells from hypergravity mice, transcripts encoding genes involved in the TLR-4 signaling pathway, the LPS receptor on B cells, have been quantified. The expression of several genes of the MyD88-Dependent pathway was increased after 21 days of hypergravity, but no change was observed in B cells stimulated with LPS. Finally, the contribution of chronic ultra-Mild stresses was evaluated. The proportions of splenic lymphocytes were not affected by these stresses. However, the levels of serum IgA were increased and those of Th1 pro-Inflammatory cytokines were decreased, as in astronauts. Thus, these stresses do not fully explain the negative impact of spaceflight conditions on humoral immunity. These researches are important to identify the cause(s) of spaceflight-Associated impaired immunity in order to test/develop effective countermeasures to strengthen the immune system of astronauts, but also of stressed or elderly people
Demangel, Rémi. "Hypoactivité, impesanteur et déconditionnement musculaire : étude des effets précoces chez l'homme dans un modèle d'immersion sèche". Thesis, Montpellier, 2017. http://www.theses.fr/2017MONT4008/document.
Texto completoFor decades, one of the challenges of space science has been to assist the astronauts during their short or long term stay, mainly in orbital flights aboard a space station. In this context, our work contributes to the understanding of muscle deconditioning associated with a stay in weightlessness and to the evaluation of differents countermeasures.Whether in the space or health sector, scientists have had the opportunity to study the effects of chronic hypoactivity and weightlessness through various experimental models that are presented in Chapter 1. Part 1 also reviews the parameters of muscle deconditioning, which are mainly loss of mass and muscle strength. These two parameters appear early in a situation of hypoactivity and are not correlated with time, which results in a decrease in force of greater amplitude than the degrees of atrophy reported. Among the explanatory factors of this disproportion, the increased accumulation of fatty infiltrations and the denervation processes are explanatory elements and have also been the subject of our experiments.Our main objective is to characterize the early alterations of skeletal muscle using a model of dry immersion (DI). This model has been recognized for several years by Russian scientists to be more severe than extended bed rest and was set up a few years ago for the first time in Europe (Toulouse). The study consisted of placing 12 healthy male volunteers in dry immersion for 3 days. This first study in Europe allowed us to characterize the early changes of muscle deconditioning at the structural and functional level. The pre- and post-DI muscle biopsies, obtained from the Vastus Lateralis muscle, were used to quantify by immunohistology the degree of muscle atrophy by fiber type and to analyze the changes in myotypology. At the structural level, we reported by MRI a 10% decrease in the volume of the quadriceps, as well as a 10% atrophy, mainly attributed to type 1 fibers. From 3 days, the percentage of fibers expressing MyHC 1 also decreased, while the percentage of hybrid fiber increased (+ 1.3%). At the functional level, the loss of muscle strength is 11%, and we note an alteration of the viscoelastic properties of the rectus femoris. At the molecular level, we reported the changes of key proteins involved in protein balance regulation, for example, an early increase in the expression of the atrogene MURF1 (+ 41%) and a decrease expression of 4EBP1 (-17%). Transcriptomic analysis by RNA-seq also highlighted a significant expression change of 2872 genes.A second study allowed us to evaluate the effects of an anti-oxidant, anti-inflammatory cocktail as countermeasure during a hypoactivity experiments of 20 days and during a bed rest of 2 months. Pre- and post-DI and BR muscle biopsies were obtained from the Vastus Lateralis muscle and reported a degree of atrophy of about 20% in both protocols. The countermeasure has mainly shown a protective effect on type Iia fibers. Analysis of the E3 ligases MuRF-1 and Atrogin-1 did not indicate any modification in the two long-term protocols.The results of our short and long term studies of muscle deconditioning underline the rapid and early changes in the muscle system and highlight the need to study finely these initial changes and biomarkers of deconditioning, in order to optimize the effects of countermeasures over this initial period
Fodili-In, Albon Soumeya. "Contribution à la mise en évidence du rôle du système nerveux périphérique dans le développement de l'atrophie musculaire liée à l'action de la microgravité simulée". Lille 1, 1996. https://pepite-depot.univ-lille.fr/LIBRE/Th_Num/1996/50376-1996-368.pdf.
Texto completoTorres, Menéndez Harol [Verfasser], Thorsten [Akademischer Betreuer] Pöschel, Thorsten [Gutachter] Pöschel y Ernesto [Gutachter] Altshuler. "Granular Leidenfrost effect in microgravity and collective dynamics of active granular particles / Harol Torres Menéndez ; Gutachter: Thorsten Pöschel, Ernesto Altshuler ; Betreuer: Thorsten Pöschel". Erlangen : Friedrich-Alexander-Universität Erlangen-Nürnberg (FAU), 2021. http://d-nb.info/1228627541/34.
Texto completoGandia, Peggy. "Influence de la microgravité simulée sur la pharmacocinétique du paracétamol utilisé comme marqueur de la vidange gastrique : étude chez le rat et chez le volontaire sain". Toulouse 3, 2003. http://www.theses.fr/2003TOU30130.
Texto completoDesplanches, Dominique. "Capacité aérobie et adaptabilité musculaire squelettique chez le Rat effets d'une microgravité simulée ou réelle, pouvoir de récupération /". Grenoble 2 : ANRT, 1987. http://catalogue.bnf.fr/ark:/12148/cb376044938.
Texto completoElston, Levi J. "The Effect of Variable Gravity on the Cooling Performance of a 16-Nozzle Spray Array". Wright State University / OhioLINK, 2008. http://rave.ohiolink.edu/etdc/view?acc_num=wright1221228402.
Texto completoMiras, Thomas. "Effets de la viscosité et de la capillarité sur les vibrations linéaires d'une structure élastique contenant un liquide incompressible". Phd thesis, Conservatoire national des arts et metiers - CNAM, 2013. http://tel.archives-ouvertes.fr/tel-00877348.
Texto completoBonjour, Julien. "Influence de l'accélération de la gravité sur les réponses cardio-respiratoires à l'exercice chez l'homme". Phd thesis, Université Jean Monnet - Saint-Etienne, 2010. http://tel.archives-ouvertes.fr/tel-00690482.
Texto completoGranet, Corinne. "Mécanismes d'adaptation de cellules ostéoblastiques Ros17/2. 8 aux variations des contraintes mécaniques dans des modèles de micro-gravité simulée et de déformation du support de culture : implication des facteurs de transcription : AP-1, Egr-1, NF-kB". Saint-Etienne, 2000. http://www.theses.fr/2000STET006T.
Texto completoEliasson, Anders. "Liquid phase sintering of W-Ni-Fe composites : liquid penetration, agglomerate separation and tungsten particle growth". Doctoral thesis, KTH, Keramteknologi, 2006. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-3870.
Texto completoQC 20100528