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Ayers, Amy L. "Windows hibernation and memory forensics." Thesis, Utica College, 2015. http://pqdtopen.proquest.com/#viewpdf?dispub=1586690.
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ABSTRACT The purpose of this capstone project was to research the hibernation file, its role in memory forensics and to explore current technology, techniques and concepts for analysis. This study includes an in-depth look at the Windows hibernation feature, file format, potential evidence saved to the file and its impacts in digital forensic investigations. This research was performed to demonstrate the importance of the hibernation file and to generate awareness for this forensic artifact. The research questions presented were designed to identify the properties of Windows hibernation and its significance in digital forensics. Additionally, these research questions were aimed at identifying the important concepts analysts should understand in selecting forensic software and in hibernation analysis. Through the literature review process, the hibernation file was identified as an essential part of digital forensics which provides analysts with snapshots of system memory from various points in the past. This data includes web, email and chat sessions in addition to running processes, login credentials, encryption keys, program data and much more. Beyond forensics, the hibernation file is useful in the fields of data recovery and incident response. A review of current hibernation file publications revealed incomplete and conflicting works culminating in the acknowledgment that more research is needed in order to close these research gaps. More awareness for hibernation forensics through its inclusion in future published works and in computer forensic educational courses is recommended. These inclusions will assist to arm practitioners with the ability to accurately utilize the hibernation file in order to obtain the highest quality forensic evidence. Keywords: Cybersecurity, hiberfil.sys, hybrid sleep, malware, slack space, Albert Orbinati.
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Seger, Rita Logan. "Elucidating the Mechanism for Maintaining Eucalcemia Despite Immobility and Anuria in the Hibernating Black Bear (Ursus americanus)." Fogler Library, University of Maine, 2008. http://www.library.umaine.edu/theses/pdf/SegerRL2008.pdf.
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Al-Mohammad, Abdallah. "Hibernating myocardium : prevalence and surrogate markers." Thesis, University of Aberdeen, 2017. http://digitool.abdn.ac.uk:80/webclient/DeliveryManager?pid=235453.
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The aims of this thesis are to determine: 1. The true prevalence of hibernating myocardium in patients with severely impaired left ventricular contraction. (Chapter 3) 2. The viability status of the left ventricular wall aneurysm as defined by positron emission tomography. (Chapter 4) 3. The relationship between the incidence of hibernating myocardium and the coronary artery flow grade determined angiographically. (Chapter 5) 4. The relationship between the presence of Q waves (with or without preserved R wave) on the surface electrocardiogram and the presence of scar in the myocardium as diagnosed by positron emission tomography. (Chapter 6) 5. The relationship between the incidence of hibernating myocardium and QT dispersion on the surface electrocardiogram. (Chapter 7) 6. Looking for other markers of hibernation by PET. (Chapters 8 and 9) I proposed to look at the relationship between continuing metabolic activity in 10 akinetic or severely hypokinetic segments as an alternative method and thus as a new definition of pre-operative determination of hibernating myocardium. This is the topic in Chapter 8. Following the completion of question number 3, and the observed role of collateral circulation, I proposed to look into the role of TIMI 0-1 and collaterals grade 2-3 in maintaining viability and their role as a marker of hibernating myocardium. This won support in the form of a research grant from the British Heart Foundation in 1998. This was the topic of my last project, which was added to the thesis after its initial completion on the 23rd of December 2000. This is the topic of Chapter 9. 7. Following the delayed submission of the Thesis in 2015, I was asked to add Chapter 11 which summarised both my contribution since the Thesis was concluded into the topic of Hibernating myocardium; and the knowledge progression into the detection of the phenomenon and its clinical usefulness to bring the Thesis up to date. Methods: The patients were those with coronary artery disease and impaired left ventricular contraction recruited into a series of studies of the presence of hibernating myocardium using positron emission tomography, as the method of choice to preoperatively detect this phenomenon. The patients were either recruited from the cardiac catheterization laboratory or from the cohort of patients presenting with myocardial infarction to the cardiology unit at Aberdeen Royal Infirmary. All the studies were approved by the Grampian Research Ethics Committee. In some of the studies, cardiac magnetic resonance imaging was used for simple assessment of the myocardial contraction and thickening in the study reported in Chapter 9. Results and Conclusions: 1. Hiberanting myocardium affects over 50% of the patients with severe left ventricular systolic impairment with coronary artery disease. (Chapter 3). 2. None of the aneurysmal segments are viable. (Chapter 4) 3. Compared to the areas supplied by arteries with Thrpmbolysis In Myocardial Infarction (TIMI) flow grades 2-3, the areas supplied by almost occluded coronary arteries (TIMI 0-1 flow grades) are significantly more likely to have both evidence of scarred myocardium (highly significantly statistical difference p < 0.0001) and evidence of hibernating myocardium, just reaching statistical significance (p < 0.05). (Chapter 5) 4. The specificity of Q waves on the electrocardiogram (ECG) as markers for 11 myocardial scarring is 79%, with a low sensitivity of 41%. (Chapter 6) 5. Maintaining R waves following a pathological Q wave on the ECG is not helpful for predicting the presence of hibernating myocardium. (Chapter 6) 6. The presence or absence of hibernating myocardium did not impact on native QT dispersion, rate corrected QTc dispersion or on the maximum adjacent QT dispersion on the ECG. (Chapter 7). 7. A new definition of hibernating myocardium is proposed, helping to detect it preoperatively through the demonstration of metabolism – mechanical mismatch defect using a single radio-pharmaceutical. (Chapter 8) 8. As a marker of the classical perfusion –metabolism mismatch defect, the new proposed metabolism-mechanical mismatch defect by PET is sensitive (92%) and specific (97%), with excellent positive and negative predictive accuracies (96% and 93%, respectively). (Chapter 8) 9. While collaterals grade 2-3 supplying territories with blocked arteries and flow grades TIMI 0-1 may be sensitive markers (83%) of hibernating myocardium; they lack specificity (20%), and the differences between the two small groups completing the study did not reach statistical significance. (Chapter 9).
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Sanders, Colin E. "Quiescent states of sleep, torpor and hibernation in the." Thesis, University of British Columbia, 2008. http://hdl.handle.net/2429/2331.
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Brazilian tegus (Tupinambis merianae) were instrumented with telemetry encoder implants that measured and broadcast heart rate (HR), breathing rate (fR), and deep body temperature (Tb) and were then allowed to freely roam in outdoor enclosures mimicking their natural environment for a full year (2004) in order to monitor the circadian and circannual patterns in behaviour and cardio-respiratory physiology. The year was divided up into 5 seasons based upon the physiology and behaviour of the tegus: early activity season (Sept.-Nov.), late activity season (Dec.-Feb.), entrance into hibernation (March-April), hibernation (May-July), and arousal from hibernation (August). The activity seasons were characterized by warm weather with frequent rainfall which slowly decreased in temperature and precipitation as tegus started entering hibernation so that the end of the dormant season was marked by dry, cold weather.
Tegus in the early activity season demonstrated high activity associated with breeding demands, displayed elevated HR and fR, and were able to maintain a large temperature differential (4-7°C) between deep body temperature (Tb) and their respective burrow (Tburrow) during sleep. As the season progressed into late activity season, average Tb remained constant but average HR and fR progressively declined indicating nightly torpor. Periods of inactivity during the active seasons were rare and associated with inclement weather. Tegus entered hibernation through bouts of inactivity that progressively increased in frequency and duration. During this time, Tb was regulated but declined at different rates in regards to daytime and nighttime values. Heart rate through the entrance into hibernation and hibernation periods frequently demonstrated arrhythmias that increased in duration but decreased with frequency as hibernation progressed. Through hibernation, Tb continued to decline for the first month but HR and fR were constant, demonstrating a temperature independent suppression of metabolism. Through the hibernation season tegus sporadically aroused and emerged from their burrows to warm up and after a short basking period would return to the burrows and swiftly resume hibernation. While hibernating, heart rate was characteristically regular but breathing was sporadic orepisodic. Arousals became more frequent towards the end of hibernation so that when they entered arousal from hibernation season most tegus were emerging daily. At this time daily maximum deep body temperature (Tbmax) swiftly returned to active season values but nighttime daily minimum deep body temperature (Tbmirt) values only showed a gradual increase through August, indicating different body temperature set points (Tbset) for active and sleep states.
Changes in heart rate and breathing rate during the year showed greatest correlation with changes in photoperiod, although throughout hibernation HR and fR also showed tight correlation with Tb.
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Guillot, Patricia. "La biochimie de l'hibernation chez les mammifères." Paris 5, 1989. http://www.theses.fr/1989PA05P112.
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Valek, Anton. "Hibernation of public space - an investigation of Stockholms water environment." Thesis, KTH, Arkitektur, 2021. http://urn.kb.se/resolve?urn=urn:nbn:se:kth:diva-298828.
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The project stems from a will to understand how I, as both a citizen and architect can partake in the creation and activation of the public water environment of Stockholm, a public sphere that I argue is largely in a state of hibernation. The main proposal is a multifunctional boat storage located at Pålsundet on Långholmen. With it I try to re-imagine the 25 hectares of centrally located plots designated to the winter storage of boats. The building strives to be an example of how to create a win-win solution where these plots could again become prime public space and year round meeting places whilst enhancing the cultural and social aspects of boat culture to more people.
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Sueldo, Rolando. "Évolution de paramètres caractéristiques de la physiologie de l'eau lors de la dormance et de sa levée dans les tubercules de stachys sieboldi, MIQ. Et de helianthus tuberosus. Relations avec le métabolisme lipidique chez hélianthus." Clermont-Ferrand 2, 1990. http://www.theses.fr/1990CLF21234.
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L'etude des parametres hydriques chez le topinambour pendant la dormance et sa levee a permis de mettre en evidence un role de l'eau dans ces deux processus physiologiques. Cette etude met en evidence qu'il y a des transfert d'eau dans les tubercules. Ces transferts apparaissent a des moments bien precis lors du stockage de ces tubercules. Ces mouvement d'eau jouer un role important dans la mise en place de la croissance tuberisee ou longue. Ces mouvements d'eau peuvent etre lies a des modifications des membranes et du protoplasme cellulaire. L'etude des modifications des moleculaires phosphorylees apporte des renseignements supplementaires sur les processus qui induisent la resistance au froid et/ou la levee de dormance. Il ressort que ces processus commencent tres tot et que les variations du phosphore lipidique et du phosphore soluble dans un milieu acide, de la region sous-apicale, peuvent servir comme marqueurs de la levee de dormance physiologique. Il faut aussi signaler que les sterols doivent jouer un role tres important dans la levee de dormance, en ce qui concerne les mouvements d'eau, de metabolistes et eventuellement dans des modifications des flux de ca#2#+ transmembranaires. Les etudes qui ont ete realisees sur le plasmalemme pendant la levee de dormance (activite de l'atpase, composition en phospholipides et fluidite) permettent de dire que le plasmalemme se reorganise durant cette periode, ce qui lui fait acquerir de nouvelles proprietes morphogenetiques
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MacDonald, Justin Anthony. "Enzyme thermal adaptations and signal transduction involvement in ground squirrel hibernation." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 1998. http://www.collectionscanada.ca/obj/s4/f2/dsk2/ftp02/NQ32342.pdf.
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Charge, T. Dic, and University of Lethbridge Faculty of Arts and Science. "Hibernation biology of Richardson's ground squirrels : hibernaculum systems and energy utilization." Thesis, Lethbridge, Alta. : University of Lethbridge. Faculty of Arts and Science, 2001, 2001. http://hdl.handle.net/10133/151.
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I studied free-living Richardson's ground squirrels (Spermophilus richardsonii) using telemetry and total body electrical conductivity (TOBEC) to evaluate overwinter energy utilization and the impact of seed caching on body composition of males. I excavated 51 hibernation systems and found that 66% of 35 males cached 1 to 4 species of seed in the hivernaculum. Pre-emergent euthermy was shorter for 3 non-caching (0.7 = 0.2 days) than for 13 caching males (4.0 = 2.8 days), and metabolic predictions of overwinter mass loss approximated actual loss for non-caching males, but over-estimated mass loss for caching males. I concluded that caching males recouped some of the mass lost during hibernation by eating the cache during the longer period of pre-emergence euthermy. Based on TOBEC, the recouped mass included both fat and lean tissue. I suggest that caching in one year is a cost of reproduction that offsets the energetic demands of mating the following year.xii, 139 leaves : ill. ; 28 cm.
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Saitongdee, Porncharn. "Cardiovascular changes during and after arousal from hibernation in golden hamsters." Thesis, University College London (University of London), 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.392885.
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Karels, Timothy J. "Reproduction, hibernation, and population regulation of arctic ground squirrels (Spermophilus parryii plesius)." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0021/NQ53885.pdf.
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Donohoe, Paul Hugh. "Factors effecting metabolic rate reduction during hibernation in the frog, Rana temporaria." Thesis, University of Cambridge, 1997. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.627309.
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Pitre, Marie-Hélène. "Composition lipidique et hibernation chez la petite chauve-souris brune (Myotis lucifugus)." Mémoire, Université de Sherbrooke, 2006. http://savoirs.usherbrooke.ca/handle/11143/4699.
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L'hiver représente un défi énergétique de taille pour les mammifères puisque l'augmentation des coûts associés à la thermorégulation est accompagnée d'une diminution marquée de la quantité de nourriture disponible. Afin de pallier à cette contrainte, certains mammifères ont recours à l'hibernation qui consiste en une diminution de la température corporelle et du rythme métabolique visant la diminution des coûts énergétiques. L'énergie nécessaire à la survie hivernale est donc préalablement emmagasinée sous forme de réserves de graisses ou de nourriture. De plus, il importe de savoir que la torpeur n'est pas un phénomène temporellement statique. En effet, les mammifères entrecoupent les périodes de torpeur par des périodes d'éveil au cours desquelles l'animal augmente sa température corporelle à un niveau semblable à celui retrouvé en euthermie. D'après plusieurs auteurs, ces périodes d'éveil servent à réétablir l'homéostasie de l'organisme. Bien qu'elles soient peu nombreuses, ces périodes d'éveil sont extrêmement coûteuses et monopolisent une grande proportion des réserves d'énergie accumulées avant l'hiver. Au cours de la torpeur, une des contraintes importante à la diminution de la température corporelle est le point de fusion des graisses. En effet, il est impératif pour tous les mammifères de conserver une température corporelle supérieure à celle du point de fusion de leurs graisses. Ceci vient du fait que la solidification des graisses inhibe leur dégradation, ce qui empêche l'utilisation de l'énergie qu'elles contiennent en plus de paralyser les fonctions des membranes cellulaires dont elles sont les principaux composants. Afin d'éviter une telle situation, le mammifère hibernant a avantage à posséder des graisses à forte teneur en acides gras polyinsaturés (AGPI) reconnus pour leur faible point de fusion. Par contre, ces derniers n'étant synthétisables par aucun vertébré ni invertébré connu, ils doivent absolument provenir de la diète et sont conséquemment considérés comme des acides gras essentiels (AGE). Jusqu'à présent, plusieurs études ont constaté l'impact positif des AGPI sur l'expression de la torpeur. En effet, une diète à forte teneur en AGPI est associée à une température corporelle minimale plus faible de même qu'à une élongation du temps passé en torpeur. Par contre, ces études furent majoritairement menées sur des mammifères rongeurs reconnus pour leur diète naturellement élevée en AGPI. D'après les résultats obtenus par ces études, il semble impossible qu'un mammifère insectivore soit en mesure d'accumuler suffisamment d'AGPI afin d'hiberner puisque la proportion d'AGPI de sa diète est environ quatre fois plus faible vis-à-vis celle d'une diète herbivore. L'objectif principal de la présente étude vise donc l'analyse de la composition lipidique de la diète et des graisses d'un mammifère insectivore, la petite chauve-souris brune ( Myotis lucifugus ). L'analyse de la diète a permis de constater que les insectes consommés par la petite chauve-souris brune possédaient 23% d'AGPI. Avant l'hibernation, les chauves-souris étudiées avaient une teneur en AGPI semblable à celle de leur diète. Par la suite, aucune utilisation préférentielle d'un certain type d'acide gras ne semble avoir été effectuée au cours de l'hiver. En effet, la proportion des acides gras insaturés (AGI), des acides gras monoinsaturés (AGMI) et des AGPI est la même au début et à la fin de l'hiver. Les périodes d'éveil étant extrêmement coûteuses, il importe de bien comprendre les variables qui les influencent. D'après certains auteurs, la quantité de graisses disponible, la température ambiante, la date, le sexe, de même que la durée des périodes de torpeur et de réveil, ont un impact sur la gestion de la torpeur. Par contre, bien que les AGPI soient reconnus pour leur effet sur l'expression de la torpeur, aucune étude n'a encore analysé leur impact chez un mammifère insectivore. Le second objectif de la présente étude vise donc à analyser l'effet du contenu des lipides en AGPI sur l'expression de la torpeur de la petite chauve-souris brune. Parmi les individus étudiés, cette dernière n'avait pas d'effet significatif sur la durée des périodes de torpeur et d'éveil. Finalement, nous avons comparé l'effet de diverses variables explicatives sur l'expression de la torpeur. Nous avons ainsi eu recours à une méthode par sélection de modèles construits à partir de variables dont l'effet sur l'expression de la torpeur avait déjà été montré dans d'autres études. Ces analyses ont permis de constater que chez les petites chauves-souris brunes étudiées et parmi les modèles testés, la durée de la torpeur augmente avec la date tandis que la durée de la torpeur et son interaction avec la masse prédite ont un effet significatif sur la durée de réveil.
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Pitre, Marie-Hélène. "Composition lipidique et hibernation chez la petite chauve-souris brune (Myotis lucifugus)." [S.l. : s.n.], 2006.
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Jackson, Diane Margaret. "The links between energetics and over-winter survival in small rodents." Thesis, University of Aberdeen, 1999. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.327595.
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Martins, Regina Lucia. "Rôle du tissu adipeux brun dans la thermogenèse sans frisson au cours du réveil d'un rongeur hibernant : le Lérot (Eliomys quercinus L.)." Toulouse 3, 1990. http://www.theses.fr/1990TOU30188.
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Notre travail de these a consiste a etudier la thermogenese sans frisson dans le tissu adipeux brun (tab) d'un rongeur hibernant, le lerot, a l'occasion de reveils provoques. Dans un premier temps, nous avons etudie la regulation adrenergique de cette thermogenese dans le tab et nos resultats montrent une forte augmentation de l'activite sympathique peripherique au cours du rechauffement. Dans un second temps, nous avons caracterise la capacite thermogenique du tab en appreciant l'activite d'une proteine specifique de la mitochondrie de ce tissu: la proteine decouplante. Pour cela la liaison du (3h) guanosine diphosphate (gdp) sur cette proteine a ete appreciee. Nous avons observe une augmentation de 33% du nombre de sites de liaison a partir d'une temperature rectale de l'animal superieure a 12#oc qui se maintient jusqu'a la fin du rechauffement. Nous avons envisage deux hypotheses pour expliquer ce resultat: 1) soit une neosynthese de la proteine induite par la stimulation noradrenergique; 2) soit un demasquage de nouveaux sites actifs. Pour verifier la premiere hypothese, nous avons apprecie, par immunoblotting, la proteine decouplante, ainsi que le taux d'arnm codant pour cette meme proteine par northern blotting. Nos resultats suggerent l'absence de neosynthese de la proteine. La seconde hypothese a ete abordee en recherchant une correlation entre la mobilisation des triglycerides dans le tab et la stimulation de la thermogenese sans frisson. En conclusion, les acides gras libres produits dans le tab sont a la fois les substrats des oxydations mitochondriales et les activateurs de la proteine decouplante
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Hershey, John Davidson. "Minimal disuse muscle atrophy and seasonal alterations in the calcium handling system in skeletal muscle of hibernating brown bears." Pullman, Wash. : Washington State University, 2008. http://www.dissertations.wsu.edu/Dissertations/Fall2008/J_Hershey_020309.pdf.
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Humphries, Murray M. "Food hoarding and hibernation in chipmunks and the ecological consequences of energetic flexibility." Thesis, McGill University, 2001. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=38068.
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Small endotherms typically have elevated and relatively invariant rates of metabolism, but adaptations such as food hoarding and hibernation endow some species with considerable energetic flexibility in responding to resource fluctuations. I examined the interactions between resource availability, food hoarding, and hibernation in a population of eastern chipmunks (Tamias striatus) subjected to seasonal and multi-annual periods of resource shortage. Incompatibility of torpor and digestion could be an important constraint associated with relying on stored food rather than body fat during hibernation, but documentation of torpor patterns and digestive efficiency of captive chipmunks revealed that digestion is actually enhanced by torpor expression. Measures of energy expenditure and food delivery by free-ranging chipmunks in autumn revealed that food hoarding also permitted rapid accumulation of large energy reserves before thermoregulatory constraints necessitated termination of above-ground activity. Thus, a combination of food hoarding and hibernation permits rapid energy accumulation when resources are abundant and effective energy conservation when resources are scarce. Despite this, chipmunks responded to experimental increases of autumn hoard size by substantially reducing winter torpor expression, suggesting that much of the resource accumulation permitted by larder hoarding is allocated to maintaining elevated rates of metabolism in the winter hibernaculum. This pattern of allocation suggests torpor expression is associated with important costs and contradicts a major paradigm of hibernation research by demonstrating that low levels of torpor expression can reflect an absence of energetic necessity rather than a lack of physiological capability. In an ecological context, the capacity of chipmunks to vary expenditure according to resource abundance represents a potent decoupling mechanism in consumer-resource interactions. Energetic flexibility of this form
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Baker, Christopher Stephen Rainald. "A study of nitric oxide metabolism in myocardial stunning, hibernation and coronary atherosclerosis." Thesis, Imperial College London, 2001. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.391143.
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Park, Kirsty Janet. "Roosting ecology and behaviour of four temperate species of bat." Thesis, University of Bristol, 1998. http://ethos.bl.uk/OrderDetails.do?uin=uk.bl.ethos.244877.
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Mountassif, Driss. "Régulation de la D-3-hydroxybutyrate déshydrogénase chez la gerboise (Jaculus orientalis) : étude biochimique, toxicologique et moléculaire." Dijon, 2007. http://www.theses.fr/2007DIJOS063.
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Les mitochondries représentent les centrales énergétiques de la cellule. Elles sont le siège de la production des corps cétoniques (3-hydroxybutyrate et acétoacétate) qui jouent un rôle important dans le métabolisme énergétique et la biosynthèse cellulaire. Ces corps cétoniques sont les produits finaux de la dégradation des acides gras. Leur production est régulée par la D-3-hydroxybutyrate déshydrogénase (BDH) : oxydo-réductase à NAD(H), située au niveau de la membrane interne mitochondriale. La BDH est de plus en plus utilisée comme sonde pour étudier l'effet des substances exogènes et des variations des états physiologiques sur le métabolisme énergétique cellulaire. Dans ce travail, nous avons isolé et caractérisé deux populations mitochondriales à savoir les mitochondries lourdes (de grande taille) et les légères (de petite taille) du foie de la gerboise (Jaculus orientalis) à l’état actif, préhibernant et hibernant. La gerboise est un rongeur doué de la capacité d'hibernation, période pendant laquelle se produisent des modifications métaboliques et énergétiques très importantes touchant tout l'organisme. Nous avons aussi caractérisé ces trois états en termes de changements cliniques et métaboliques spécialement au niveau de la BDH (changement au niveau de l’expression et des propriétés catalytiques). Nous avons également étudié l'effet in vivo sur la gerboise et in vitro sur la BDH de deux produits à effet hypolipémiant et qui ont des structures proches (ciprofibrate et 2,4D). Le ciprofibrate est un médicament de la classe des fibrates très utilisé au Maroc pour soigner les dyslipidémies, et le 2,4D est utilisé en agriculture pour traiter les plantes parasites afin d’améliorer les récoltes. Enfin, nous avons développé une nouvelle méthode pour la purification de la BDH à partir de Jaculus orientalis (eucaryote) en se basant sur les anticorps polyclonaux produits contre la BDH purifiée à partir de Pseudomonas aeruginosa (procaryote). Nous avons complété cette étude par l’amplification par RT-PCR, clonage et séquençage du cDNA codant la BDH de la gerboise. La comparaison entre la séquence obtenue et celle d’autres mammifères a montré une grande conservation des acides aminés témoignant de l’importance de la BDH dans le métabolisme énergétiqueMitochondria represent the seat of the production of ketone bodies (3-hydroxybutyrate and acetoacetate) which play an important role in the energy metabolism and the cellular biosynthesis. These ketone bodies are the final products of the degradation of fatty acids. Their production is regulated by D-3-hydroxybutyrate dehydrogenase (BDH): oxydo-reductase, situated at the inner mitochondrial membrane. The BDH is used as probe to study the effect of exogenous substances and variations of the physiological states on the cellular energy metabolism. In this work, we isolated and characterized two mitochondrial populations: the heavy and the light mitochondria in the liver of the jerboa (Jaculus orientalis, true hibernator rodent) at active, prehibernating and hibernating states. We also characterized these three states in term of metabolic changes especially at the level of the BDH (change at the level of the expression and the catalytic properties). We also studied the in vivo and in vitro effect on the jerboa and BDH of two hypolipidemic molecules (ciprofibrate and 2,4D). The ciprofibrate is a medicine of the class of fibrates very used in Morocco to cure dyslipidemia, and the 2,4D is used in agriculture to treat parasites to improve the harvests. Finally, we developed a new method for the purification of the BDH from Jaculus orientalis (eucaryote) using polyclonal antibodies against the BDH purified from Pseudomonas aeruginosa (procaryote). We completed this study by the amplification by RT-PCR, cloning and sequencing of the cDNA coding the BDH of the jerboa. The comparison between the obtained sequence and others showed an important conservation of amino acids which play important role in BDH catalysis and subsequently in the energy metabolism
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Reidy, Shannon Patricia. "The effects of prolonged fasting, hibernation and leptin on in vivo lipid metabolism in mammals." Thesis, National Library of Canada = Bibliothèque nationale du Canada, 2000. http://www.collectionscanada.ca/obj/s4/f2/dsk1/tape2/PQDD_0020/NQ57163.pdf.
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Castaing, Laurent. "Hibernation et reproduction du hérisson (erinaceus europaeus L. ) : interrelations et régulation par les facteurs externes." Tours, 1985. http://www.theses.fr/1985TOUR4008.
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Chazarin, Blandine. "Développements en protéomique pour mieux comprendre la physiologie de l’ours brun hibernant et ouvrir la voie vers de nouvelles thérapies contre l’atrophie musculaire humaine." Thesis, Strasbourg, 2019. http://www.theses.fr/2019STRAF037.
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Appliquer les stratégies d’analyse protéomique à des échantillons d’organismes « exotiques » requiert des développements, que nous avons réalisés pour étudier les mécanismes d’épargne protéique chez l’ours brun hibernant. La complémentarité des approches protéomiques (SDS PaGE-XIC, 2D-DIGE-MS, LC-SRM-MS) et des développements bioinformatiques (e.g. utilisation de données d’assemblage du génome, extraction d’annotations fonctionnelles [Gene Ontology, neXtProt, KEGG]) ont montré que la beta-oxydation est préférentielle dans le muscle, la glycolyse étant maintenue. Les niveaux élevés en acides gras omega 3, le stress oxydant diminué, et l’existence de composés anti-protéolytiques dans le sérum des ours hibernants contribuent à l’épargne des muscles. Pour identifier ces composés, nous avons développé le fractionnement du sérum d’ours (chromatographie, protéolyse, déplétion des protéines majoritaires) et montré que les corps cétoniques pourraient être impliqués. Ces résultats suggèrent de nouvelles solutions thérapeutiques contre l’atrophie musculaire des personnes immobilisées, âgées ou encore des astronautesTo analyze samples from "exotic" organisms using proteomics, analytical developments are required. Our developments were made to study protein saving mechanisms in hibernating brown bears. The complementarity of proteomics approaches (SDS PaGE-XIC, 2D-DIGE-MS, LC-SRM-MS) and bioinformatics developments (e.g. use of genome assembly data, extraction of functional annotations [Gene Ontology, neXtProt, KEGG]) have led to show that muscle beta-oxidation is preferential, glycolysis being maintained. High levels of omega 3 fatty acids, decreased oxidative stress, and the existence of anti-proteolytic compounds in the serum of hibernating bears contribute to muscle sparing. To identify these compounds, we developed fractionation of the bear serum (chromatography, proteolysis, high abundance protein depletion) and showed that ketone bodies could be involved. These results suggest new therapeutic solutions against muscle atrophy in immobilized people, the elderly or astronauts
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Webb, Cheryl Lynn. "Aspects of the control of breathing in the golden-mantled ground squirrel." Thesis, University of British Columbia, 1987. http://hdl.handle.net/2429/26662.
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Spermophilus lateralis, the golden-mantled ground squirrel, while euthermic exhibits a strong hypoxic ventilatory response, but a relatively blunted hypercapnic ventilatory response similar to other semi-fossorial mammals. Under resting conditions, carotid body
chemoreceptors provide a tonic excitatory input to the frequency component of ventilation. Carotid body
denervation (CBX) results in a 40% decrease in minute ventilation (V). The overall ventilatory response to hypoxia is unaffected by CBX, although the ventilatory threshold is significantly shifted to lower levels of inspired O₂. CBX also has little effect on the overall response to hypercapnia. Thus, in S. lateralis, it appears that changes in the partial pressure of O₂ (P0₂) In the blood act centrally, rather than peripherally, to play a predominate role in ventilatory control.
Chronic exposure to hypoxia and hypercapnia (CHH, 17% O₂ and 4% CO₂) does not result in overall ventilatory acclimation, with minute ventilation being similar to control squirrels acutely exposed to hypoxic and hypercapnic conditions. In spite of this, CHH exposure does result in adjustments to respiration; frequency is decreased and tidal volume is elevated compared to control squirrels acutely exposed to CHH conditions. Overall V sensitivities to both hypoxia and hypercapnia are not significantly altered by CHH exposure. It appears that acclimation to chronic hypoxic and hypercapnic conditions in S. lateralis may increase alveolar minute ventilation relative to total minute ventilation and thus minimize the changes in arterial PO₂ and Pco₂ during hypoxic and hypercapnic exposure.
During entrance into hibernation, as metabolic rate and body temperature decline, concomitant decreases in ventilation occur. Two patterns of respiration occur during deep hibernation; a burst breathing pattern characterized by long non-ventilatory periods (Tnvp) separated by bursts of several breaths and a single breath pattern characterized by single breaths separated by a relatively short Tnvp.
In S. lateralis during hibernation at body temperatures between 6° and 10°C, a burst breathing pattern prevails. At slightly lower body temperatures, less than 4°C, a single breath breathing pattern prevails. Both burst breathing and single breath breathing squirrels have similar overall levels of resting minute ventilation. Burst breathing squirrels exhibit a significant respiratory response to hypoxia (3% O₂) and when the decreases in metabolic rate during hibernation are taken into account (air convection requirement) their hypoxic sensitivity is similar to that in awake S. lateralis. In contrast, single breath breathing squirrels do not respond to hypoxia at any level tested (down to 3% O₂). Both burst breathing and single breath breathing squirrels show large ventilatory repsonses to hypercapnia. In the burst breathing state hypercapnic sensitivity is significantly higher compared to the single breath breathing state, due to an augmented frequency response during burst breathing. In both groups of hibernating squirrels ventilation is increased during hypercapnia solely by decreases in the nonventilatory period. When ventilation is standardized for the decreases in metabolic rate during hibernation both burst breathing and single breath breathing S. laterlis exhibit a much higher hypercapnic sensitivity than that seen in awake S. lateralis. Carotid body denervation has little effect on ventilatory pattern generation or ventilatory sensitivities to hypoxia and hypercapnia in hibernating squirrels.
It appears that during hibernation in S. lateralis, ventilation is controlled primarily by changes in the partial pressure of CO₂ (Pc0₂) in tne blood acting centrally to stimulate ventilation. The burst breathing pattern is produced centrally, as are the respiratory responses to hypoxia and hypercapnia. Thus, central mechanisms involved with ventilatory control are extremely important in both the euthermic state and the hibernating state, but the chemical stimuli regulating ventilation appear to be fundamentally different in euthermic and hibernating S. lateralis.Science, Faculty of
Zoology, Department of
Graduate
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El, Kebbaj Zakaria. "La β-oxydation peroxysomale des acides gras : rôle de l’acyl-CoA oxydase et régulation par les PPARs chez la gerboise (Jaculus orientalis)." Dijon, 2007. http://www.theses.fr/2007DIJOS064.
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La gerboise (Jaculus orientalis) est un modèle idéal pour étudier l’adaptation du métabolisme lipidique à basse température. Pendant la phase d’hibernation, la température corporelle de la gerboise passe de 37 à 10°C et sa fréquence cardiaque passe de 300 à 10 battements par minute. Cet état d’hibernation est précédé par une phase de préhibernation pendant laquelle la gerboise accroît sa ration alimentaire et développe ainsi une obésité saisonnière naturelle. Dans ce contexte, nous avons étudié la β-oxydation peroxysomale des acides gras et sa régulation pendant l’hibernation par le récepteur nucléaire PPARalpha (peroxisome-proliferator activated receptor). Nos résultats ont montré pour la première fois la présence de 2 isoformes de PPARalpha chez un rongeur comme la gerboise (absent chez le rat et la souris) : PPARalpha1wt (actif) et PPARalpha2tr (jouant un rôle de dominant négatif sur PPARalpha1). Nous avons pu démontrer l’importance du ratio PPARalpha1wt / PPARalpha2tr dans l’induction de ses gènes cibles (ACOX-1, BFE, catalase, PMP70). Ainsi, pendant l’hibernation, l’augmentation de la disponibilité de la forme active PPARalpha1wt, due à une forte diminution de l’expression des ARNm et l’expression protéique de PPARalpha2tr, est accompagnée par une augmentation concomitante d’un coactivateur thermogénique de PPARalpha (PGC-1alpha). Nos résultats suggèrent fortement que PPARalpha est sujet à régulation par un épissage alternative pendant l’hibernation en réponse aux conditions du jeûne et du froid, qui définit l’activité de PPARalpha et l’activation de la voie de la β-oxydation peroxysomale hépatique. Et d’une manière intéressante, l’activation de PPARalpha par un ligand hypolipémiant, ciprofibrate, abroge la réponse adaptative de PPARalpha au jeûne pendant la préhibernation et induit fortement ses gènes cibles, ce qui perturbe le processus d’engraissement pendant la préhibernation. Par ailleurs, Au niveau cardiaque, les acides gras constituent la source principale d’énergie, particulièrement pendant l’hibernation. Nous avons pu mettre en évidence la présence d’une isoenzyme de l’acyl-CoA oxydase-1 (ACOX-1) exprimée de manière spécifique dans le cœur de la gerboise hibernante, soulignant le rôle remarquable de la β-oxydation peroxysomale au cours de la période critique d’hibernation. En outre, nous avons partiellement purifié l’ACOX-1 hépatique et nous avons mené une étude biochimique de cet enzyme. En effet, l’ACOX-1 suit une cinétique allostérique à 37°C, alors qu’à 10°C elle suit une cinétique michaélienne, ce qui rend le facteur température un effecteur allostériqueAs true hibernator, jerboa (Jaculus orientalis) is an excellent animal model to study lipid metabolism adaptation to low body temperature. During hibernation state, jerboa body temperature drops from 37°C to 10°C and its heart frequency decreases from 300 to 10 beat/min. Hibernation, in Jaculus orientalis, is preceded by prehibernating period during which the animal increases its fat content indicating a natural seasonal obesity. In this context, we have studied a peroxisomal fatty acids β-oxidation and its regulation during hibernation by the nuclear receptor PPARalpha (peroxisome-proliferator activated receptor). Our results describe for the first time the occurrence of two PPARalpha isoforms in rodent liver like jerboa (absent in rat and mice): PPARalpha1wt (active) and PPARalpha2tr (playing a dominant negative role on PPARalpha1wt). We have shown the importance of the ratio of PPARalpha1wt / PPARalpha2tr in the control of its target genes (ACOX-1, BFE, catalase, PMP70). Thus, during hibernating state, the increased availability of active PPARa1wt, is a result of a decline in the PPARalpha2 mRNA and its protein expression accompanied by a concomitant induction of PPARalpha thermogenic coactivator PGC-1alpha. Our results strongly suggest that PPARalpha is subject to a hibernation-dependent splicing regulation in response to feeding-fasting conditions, which defines the activity of PPARalpha and the activation of the hepatic peroxisomal β-oxidation pathway. Interestingly, sustained activation of PPARalpha by its hypolipidemic ligand, ciprofibrate, abrogates the adaptive fasting response of PPARalpha during prehibernation and overinduces its target genes, disrupting the prehibernation fattening process. Elsewhere, in heart, such fatty acids peroxisomal degradation system is involved in the energy supply, particularly during hibernation. Indeed, we were able to identify in heart the presence of a hibernation-dependent peroxisomal acyl-CoA oxidase-1 (ACOX-1) isoenzyme. Underlining the remarkable role of peroxisome fatty acid β-oxidation during the critical hibernation period. In addition, we partially purified the liver ACOX-1 and conducted a biochemical study. Hepatic ACOX-1 follows an allosteric kinetic at 37 ° C, whereas at 10 ° C it follows a michaelien kinetic, this makes the temperature an allosteric effector of ACOX-1 activity
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Pagès, Marie. "Apport de données d'ADN nucléaire à la phylogénie et à la biologie de la conservation des Ursidae." Montpellier 2, 2007. http://www.theses.fr/2007MON20147.
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La famille des Ursidae comprend à l'heure actuelle huit espèces d'ours. Elle constitue un groupe des plus insolites au sein de l'ordre des Carnivores notamment en raison de ses adaptations physiologiques particulières liées à l'hibernation. Celles-ci, uniques dans le règne animal, confèrent au modèle ours un intérêt majeur en recherche médicale, en pleine expansion aux vues de ses applications cliniques potentielles, point qui sera développé en introduction de ce manuscrit. Paradoxalement, les relations de parenté entre les divers représentants des Ursidae actuels restent quant à elles à ce jour encore irrésolues. Aussi, afin de clarifier leur phylogénie, nous avons séquencé 12 gènes nucléaires pour l'ensemble des Ursidae (soit près de 8 kilobases correspondant à 6 gènes impliqués dans la cascade des hormones thyroïdiennes, 3 gènes spécifiques aux chromosomes sexuels, et 3 gènes localisés sur des autosomes). En combinant ces nouvelles données avec celles disponibles dans les banques de séquences, des reconstructions phylogénétiques en méthode du maximum de vraisemblance et analyse bayésienne ont été réalisées sur un jeu total de près de 10 kilobases d'ADN nucléaire, et ont alors permis de préciser les relations de parenté entre les espèces d'ours actuels. Par ailleurs, l'étude des gènes SRY (Sex determining region of the Y chromosome), ZFX/ZFY (Zinc Finger protein) et AMLX/AMLY (Amelogenine) a permis de développer un système moléculaire fiable de détermination du sexe des Ursidae à partir de l'ADN extrait d'échantillons non invasifs tels les poils ou les faeces. Si l'intérêt de cet outil apparaît évident pour la biologie de la conservation des ours alors que la quasi-totalité des espèces actuelles est menacée d'extinction, il ouvre également de nouvelles perspectives en paléontologie. Ce type d'analyse a en effet été appliqué à des échantillons fossiles d'ours bruns d'Afrique du Nord (Ursus arctos). Le dernier chapitre de ce manuscrit illustre alors comment la paléogénétique peut venir en renfort à la paléontologie pour interpréter la variation des formes fossilesCurrently, the Ursidae family includes eight bear species. They represent an unusual family within the order of the Carnivores because of their peculiar physiological adaptations related to hibernation. These physiological features, unique in the animal kingdom, make bear a unique model for medical research in full expansion because of its putative clinical applications. This point will be developed in introduction of this manuscript. Surprisingly, the phylogenetic relationships within the extant Ursid representatives remain unclear. In order to clarify their phylogeny, we sequenced 12 nuclear genes for all the Ursid species (nearly 8 kilobases corresponding to 6 genes implied in the pathway of the thyroid hormones, 3 genes specific to the sexual chromosomes, and 3 other autosomal genes). By concatenating these new data with those available in the sequence databanks, phylogenetic reconstructions (maximum likelihood and bayesian analyses) were carried out on a nuclear DNA dataset of 10 kilobases. It was then possible to refine the phylogeny of the Ursidae family. In addition, based on the study of the genes SRY (Sex determining region of the Y chromosome), ZFX/ZFY (Zinc Finger protein) and AMLX/AMLY (Amelogenine), we developed a reliable method to determine the sex of Ursidae based on the analysis of DNA extracted from non invasive samples such as hairs or faeces. If this tool has obvious implication for the conservation biology of Ursidae (most of the extant species are threatened with extinction), it also opens new prospects in palaeontology. This kind of analysis was indeed applied to samples of fossils of North African brown bears (Ursus arctos). The last chapter of this manuscript illustrates how the palaeogenetics can help palaeontology interpreting the variability of fossil forms
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Bethany, Williams. "Nitric oxide metabolites in hypoxia, freezing, and hibernation of the wood frog, Rana sylvatica." Miami University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=miami1525202133341325.
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Baker, Patrick J. III. "Physiology and Ecology of Terrestrially-hibernating Hatchling Turtles." Miami University / OhioLINK, 2009. http://rave.ohiolink.edu/etdc/view?acc_num=miami1239276024.
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Bae, Jung Yoon. "Reversible Regulation of Cell Cycle-Related Genes by Epigallocatechin Gallate for Hibernation of Neonatal Human Tarsal Fibroblasts." Kyoto University, 2009. http://hdl.handle.net/2433/124083.
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Giordano, Céline. "Pre-Clinical Evaluation of Biopolymer Delivered Circulating Angiogenic Cells in Hibernating Myocardium." Thèse, Université d'Ottawa / University of Ottawa, 2011. http://hdl.handle.net/10393/20619.
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Vasculogenic cell-based therapy combined with tissue engineering is a promising revascularization strategy for patients with hibernating myocardium, a common clinical condition. We used a clinically relevant swine model of hibernating myocardium to examine the benefits of biopolymer-supported delivery of circulating angiogenic cells (CACs) in this context.
Twenty-five swine underwent placement of an ameroid constrictor on the left circumflex artery (LCx). After 2 weeks, positron emission tomography measures of myocardial blood flow (MBF) and myocardial flow reserve (MFR) were reduced in the affected region (both p<0.001). Hibernation (mismatch) was specific to the LCx territory. Swine were randomized to receive intramyocardial injections of PBS control (n=10), CACs (n=8), or CACs + a collagen-based matrix (n=7). At follow-up, stress MBF and MFR were increased only in the cells+matrix group (p<0.01), and mismatch was lower in the cells+matrix treated animals (p=0.02) compared to controls. Similar results were found using microsphere-measured MBF. Wall motion abnormalities and ejection fraction improved only in the cells+matrix group.
This preclinical swine model demonstrated ischemia and hibernation, which was improved by the combined delivery of CACs and a collagen-based matrix. To our knowledge, this is the first demonstration of the mechanisms and effects of combining progenitor cells and biopolymers in the setting of myocardial hibernation, a common clinical condition in patients with advanced coronary artery disease.
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Atgié, Claude. "Prise alimentaire et niveau de l'activité adrénergique périphérique chez un rongeur hibernant, le Lérot Eliomys quercinus L." Toulouse 3, 1990. http://www.theses.fr/1990TOU30059.
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L'objectif de ce travail etait d'etablir un lien entre la modulation de la prise alimentaire chez un rongeur hibernant, le lerot (eliomys quercinus l. ) et l'activite sympathique peripherique. Les cycles de la prise alimentaire, du poids corporel et de la depense energetique basale ont ete precises sur une periode de 18 mois. 1) dans la semaine qui precede l'induction de la periode hnibernale, le poids corporel est maximum et la prise alimentaire est minimale ainsi que la depense energetique comparativement aux valeurs enregistrees aux autres periodes du cycle. 2) la reprise de l'alimentation se deroule pendant le dernier tiers de l'hibernation et passe par un maximum au moment du reveil vernal. 3) au cours d'un cycle homeothermie-hypothermie-rechauffement spontane, nous avons mis en evidence une chute de l'ingere energetique 24 h avant cette sequence, par contre, la prise alimentaire est augmentee durant les 24 h post-reveil. Dans ces trois situations, nous observons une faible activite du systeme sympathique peripherique chez l'animal hypophagique alors qu'elle est plus elevee chez l'animal hyperphagique. D'autres resultats rapportes ici, sont en faveur de l'hypothese selon laquelle, la chute de la prise alimentaire, pre-hibernale favorise l'induction d'une hypoglycemie a l'origine d'une baisse du tonus sympathique avec pour consequence une diminution de la depense energetique elle-meme responsable de la perte de l'homeothermie
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English, Tamara Erica Carleton University Dissertation Biology. "Enzymes of adenylate metabolism from the skeletal muscle of the hibernating prairie dog, Cynomys leucurus." Ottawa, 1995.
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Carey, Charleve. "IS DISRUPTION TO PASSIVE GAS-EXCHANGE A MECHANISM OF DEHYDRATION FOR WNS-INFECTED HIBERNATING BATS?" OpenSIUC, 2014. https://opensiuc.lib.siu.edu/theses/1532.
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Emergent epizootics are responsible for dramatic declines in wildlife populations over the past few years. An emerging fungal-borne epizootic, called white-nose syndrome (WNS), is responsible for a catastrophic decline of hibernating bats in North America The fungus, Pseudogymnoascus destructans (Pd), is the causative agent of WNS, but to date, we have limited understanding of how an infection with Pd can lead to mortality in hibernating bats. Evidence suggests dehydration is an important part of the pathogenesis of WNS. Cryan et al. (2010) proposed four possible mechanisms by which infection could lead to dehydration. In this study, I tested one of these hypotheses - Pd infection could cause disruption to passive gas-exchange pathways across the wing membranes, thereby causing a compensatory increase in water-intensive pulmonary respiration. I hypothesized total evaporative water loss would be greater when passive gas-exchange was inhibited, especially at low ambient temperatures. I found that bats did not lose more water when passive gas-exchange was retarded (at least within the resolution of my equipment). This study provides evidence against the proposed proximal mechanism that disruption to passive gas-exchange causes dehydration and ultimately death to WNS-infected bats.
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Weitten, Mathieu. "Adaptations métaboliques et influence du régime alimentaire chez un hibernant food-storing." Thesis, Strasbourg, 2015. http://www.theses.fr/2015STRAJ080/document.
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Cette thèse présente les adaptations spécifiques des hibernants ‘food-storing’ qui s’alimentent au cours de l’hibernation, et les conséquences de la qualité du régime alimentaire sur leur cycle annuel. Tandis que les espèces ‘fat-storing’ jeûnent pendant toute l’hibernation, les ‘food-storing’ alternent jeûnes courts et réalimentations. L’adiponectine stimulerait la lipolyse pendant l’hibernation contribuant ainsi à la cétogenèse. Le maintien d’un système digestif fonctionnel conduisant à la sécrétion d’incrétines, permet l’absorption optimale de nutriments lors des courtes euthermies inter-torpeurs. Une absorption accrue de glucose en particulier permettrait de restaurer la glycémie et les réserves de glycogène. Par ailleurs, un régime appauvri en protéines et enrichi en lipides induit un engraissement augmenté en période pré-hibernatoire provoquant une moindre utilisation de la torpeur donc une perte de masse accrue lors de l’hibernation, et une baisse du succès reproducteurThis thesis presents the specific adaptations of food-storing hibernators that feed during hibernation, and the impact of diet quality on their annual cycle. In contrast to the fat-Storing species which fast during hibernation, the food-storing presents metabolic responses to an alternation of short fasting phases and hyperphagia. These responses involve one hand use of fat reserves during hibernation contributing to ketogenesis, which would be induced by adiponectin. On the other hand, maintaining a functional digestive system leading to the secretion of incretins, permits optimal nutrient absorption in the short inter-torpor euthermia. Increased glucose uptake in particular would restore body reserves to spare. Moreover, a lean protein diet enriched in fat and induces increased in body mass in pre-hibernation period causing reduced use of torpor thus an increased loss of mass during hibernation, and decreased reproductive success
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Stratton, Kalera. "The Influence of Hibernation Temperature on Deiodinase 2 in Red-Sided Garter Snakes (Thamnophis sirtalis parietalis)." PDXScholar, 2019. https://pdxscholar.library.pdx.edu/open_access_etds/4865.
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Environmental cues such as day length and temperature contribute to timing of biological rhythms in seasonal breeders. Life-history transitions such as spring emergence from hibernation, migration, or mating must be coordinated with environmental conditions or survival is compromised. Therefore, there must be chemical signaling pathways in the brain that transduce seasonally-changing sensory inputs into signals that initiate a hormonal cascade, culminating in reproductive behavior. The relative importance of environmental cues to reproductive timing varies with species, time of year, and sex, and the mechanisms driving these differences remain unknown. The role of photoperiod in regulating reproductive behavior has been explored in birds and mammals, but much less is known about the role of so-called supplementary cues such as temperature, which is crucial in the timing of ectotherm reproduction. This is a critical gap in our knowledge, because shifts in seasonal temperatures due to climate change could create a mismatch between peak reproductive behavior and resources necessary for gestation and offspring survival. Deiodinase 2 (DIO2) enzyme is a critical component of the pathway that mediates reproduction in photoperiod-activated seasonal breeders, but whether deiodinase 2 is sensitive to seasonal changes in environmental temperature is unknown. In this study, we used an ectothermic vertebrate known to be a temperature-activated seasonal breeder, the red-sided garter snake (Thamnophis sirtalis parietalis), to investigate changes in hypothalamic DIO2 in response to hibernation at 4°C and 12°C. We captured male and female snakes in Manitoba, Canada as they returned to their winter den site from summer feeding grounds. Snakes were hibernated in complete darkness at either 4°C or 12°C for up to 16 weeks. A subset of each sex and temperature group were euthanized at intervals, and the brains collected and processed for DIO2 immunohistochemistry. DIO2-specific staining was found in the anterior hypothalamus, in the periventricular hypothalamic nucleus and ventral pre-optic area, along the longitudinally central region of the olfactory tract, in the bed nucleus of the stria terminalis, caudally in the cortex and optic tectum, and in the lateral septal nucleus. DIO2-stained area in the anterior hypothalamus was quantified. Male T. sirtalis in both the 4°C and 12°C groups were found to have an increase in DIO2-specific staining in the anterior hypothalamus after 8 weeks in hibernation. Female T. sirtalis were found to have an increase in DIO2-specific staining in the anterior hypothalamus after 8 weeks in the 12°C group only. These findings shed light on the neuroendocrine pathway through which environmental cues other than photoperiod influence the timing of seasonal reproduction, and support the hypothesis that at least some components of this pathway are conserved across seasonal breeders.
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Hausmann, Harald. "Myokardrevaskularisation bei hochgradig eingeschränkter linksventrikulärer Funktion." Doctoral thesis, Humboldt-Universität zu Berlin, Medizinische Fakultät - Universitätsklinikum Charité, 2004. http://dx.doi.org/10.18452/13909.
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Faktoren, die die funktionelle Erholung von hibernating myocardium nach aortokoronarem Venen Bypass (ACVB) beeinflussen, werden gegenwärtig untersucht. Von 3/2000 bis 3/2003 untersuchten wir prospektiv 41 Patienten mit einer linksventrikulären Ejektionsfraktion (LVEF)Objectives: Factors that influence functional recovery of hibernating myocardium after coronary artery bypass grafting are at present under investigation. Methods: From 3/2000 to 3/2003 we prospectively analyzed 41 patients with ejection fraction (EF) 15% during DE in group I preoperatively; the increase was < 15% in group II. MRI hyperenhancement was measured with a mean of 16,7±11,6% of the left ventricle in group I compared to a mean of 27,4±14,4% in group II (p 19µm) in group I than in group II (< 17µm). Gene expression of pro-apoptotic genes such as BAK and BAX was lowered (0.5±0.1/0.8±0.1) compared to "normal" myocardium (1.0±0.1) (p
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Landry-Cuerrier, Manuelle. "From habitat to energetics : eastern chipmunk burrow microhabitat selection and fine-scale variation in winter torpor expression." Thesis, McGill University, 2008. http://digitool.Library.McGill.CA:80/R/?func=dbin-jump-full&object_id=112530.
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This thesis evaluates, in free-ranging eastern chipmunks (Tamias striatus), burrow site selection, the effect of burrow microhabitat on individual behaviour and winter torpor expression, as well as resource and climate determinants of fine-scale variation in winter torpor expression and energetics. This was accomplished by characterizing burrow microhabitat, performing behavioural observations, and monitoring winter torpor expression. Among several burrow microhabitat variables related to food availability, predation risk, and hibernacula microclimate, availability of woody debris was the best predictor of burrow site use. Anti-predator benefits associated with availability and use of woody debris are potentially more important than those associated with burrow microhabitat features that are either too spatially invariant (soil temperatures) or too spatially and temporally variant (food sources). Abundance of tree-seeds drastically reduced winter torpor, increasing considerably winter energy consumption, and local density of seed-producing trees was responsible for fine-scale spatial variation in torpor expression. The potential range in winter torpor expression and energy consumption was constrained by microclimate, whereas observed patterns of winter torpor and energy consumption were highly variable and determined primarily by local food abundance.
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Mills, Cheryl Anne. "Conservation and ecology of the hazel dormouse, Muscardinus avellanarius." Thesis, University of Exeter, 2012. http://hdl.handle.net/10036/3907.
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Conservation biologists require information on the distribution, ecology, behaviour and genetic diversity of endangered species in order to identify threatened populations, determine which mechanisms are driving populations closer to extinction, and design appropriate mitigating solutions. The hazel dormouse, Muscardinus avellanarius, is declining across much of its northern range. Dormice are detrimentally affected by habitat degradation, loss and fragmentation. Despite extensive studies and conservation work on hazel dormice, there remain many gaps in our understanding. This thesis aims to fill some of those gaps. Hazel dormice are elusive, and therefore difficult to monitor in the wild. I demonstrate the utility of novel monitoring techniques for the rapid determination of dormouse presence, and provide algorithms for the objective verification of species identity from small mammal footprints. I design and utilise genetic microsatellite markers to investigate molecular ecology in this species. In one of the first studies of hazel dormouse population genetics, I describe high levels of population differentiation and genetic isolation across the southwest UK range. I find a powerful signal of reduction in genetic diversity, and an increase in differentiation between core and peripheral populations. I consider rival hypotheses for the mechanisms driving this population genetic pattern, and place the results in the context of conservation strategies for UK dormice. Further, I use molecular data to investigate the prevalence of multiple paternity in wild dormouse populations. Results contradict a recent estimate of very high rates of polyandry, but remain high at 50%. I investigate the effect of food availability on the hibernation behaviour of dormice. My findings, which demonstrate dormice are variable and flexible in their response to winter diet, increases our understanding of the trade-offs dormice must make in order to survive winter periods. I hope that the research undertaken for this thesis will add to the understanding and conservation of an iconic British mammal, ultimately contributing to the persistence of this species.
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Meyer, Michael. "Die Rolle des Toll-like-Rezeptor 4 bei chronisch-reduzierter Koronardurchblutung ("hibernation") : Beobachtungen an einem murinen In-vitro-Modell /." Bonn, 2008. http://opac.nebis.ch/cgi-bin/showAbstract.pl?sys=000253862.
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Gaglia, Marta Maria. "Dopamine modulation of quiescence in dauer larvae, and other investigations on hibernation and lifespan in the nematode Caenorhabditis elegans." Diss., Search in ProQuest Dissertations & Theses. UC Only, 2008. http://gateway.proquest.com/openurl?url_ver=Z39.88-2004&rft_val_fmt=info:ofi/fmt:kev:mtx:dissertation&res_dat=xri:pqdiss&rft_dat=xri:pqdiss:3339187.
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Cochet, Nathalie. "Lipolyse et acides gras dans deux dépôts adipeux blancs au cours du cycle saisonnier de la marmotte alpine (Marmota marmota)." Lyon 1, 1996. http://www.theses.fr/1996LYO10193.
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Chez la marmotte alpine, le processus d'hibernation necessite l'accumulation de reserves adipeuses au cours de la saison estivale. Ces reserves seront utilisees progressivement au cours des 5 mois du jeune hivernal associe a l'hibernation. Chez la marmotte, la masse lipidique totale represente le tiers de la masse corporelle et se repartie en depots sous-cutanes et intra-abdominaux. Au cours de l'hibernation, la temperature centrale de la marmotte chute d'environ 30c et malgre cela l'animal maintient un niveau minimal d'activite cellulaire ainsi qu'une mobilisation basale des substrats energetiques. De tels processus ne pourraient avoir lieu sans adaptations tissulaires particulieres. L'etude de la regulation hormonale de la lipolyse sur des adipocytes isoles de tissu adipeux blanc sous-cutane (inguinal) et abdominal (gonadique) au cours du cycle saisonnier de la marmotte a montre que le depot gonadique etait plus sensible aux changements de l'etat nutritionnel des animaux que le depot sous cutane. Ces resultats suggerent que le site assurant preferentiellement la mobilisation des substrats energetiques pourrait changer en fonction de l'etat nutritionnel des marmottes. L'analyse des acides gras contenus dans les deux depots adipeux montre que la marmotte accumule plus de 60 pour-cent d'acides gras monoinsatures alors que l'aliment renferme plus de 50 pour-cent d'acides gras polyinsatures. Aucune variation de la composition en acides gras des deux depots n'a ete mise en evidence au cours du cycle saisonnier chez cet animal, meme apres 5 mois de jeune. Ceci est d'autant plus surprenant qu'une diminution de 30 pour-cent de la masse corporelle est observee en hiver et que la proportion des acides gras rejetes in vitro par les adipocytes isoles est differente de celle des triglycerides contenus dans ces cellules
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Vignault, Marie-Paule. "Gestion des réserves au cours du cycle annuel chez un animal hibernant, le hérisson (Erinaceus europaeus L. )." Tours, 1994. http://www.theses.fr/1994TOUR4005.
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Le hérisson gère sa balance énergétique différemment selon les saisons et selon les sexes. Pendant toute l'hibernation, la biotélémétrie de température a permis de suivre en continu les variations de la température corporelle chez l'animal en conditions climatiques naturelles. Nous avons montré que: lors de l'entrée en hibernation, plus précoce chez les mâles, de courtes hypothermies nocturnes apparaissent, pendant l'hibernation proprement dite, la durée des phases de torpeur augmente lorsque la température ambiante diminue, la sortie de l'hibernation est plus précoce chez les mâles (janvier, rythme interne) que chez les femelles (mars-avril, dépendante des conditions du milieu). Nous avons mesuré par calorimétrie indirecte l'importance des dépenses énergétiques au cours de chaque phase : le coût de l'hypothermie représente 1/100eme du coût de l'euthermie et le coût du réchauffement est très élevé. A partir de ces mesures (durée et coût), nous avons établi le bilan énergétique de l'hibernation: l'économie est de 51% par mois chez les mâles et de 62%, chez les femelles. Pendant la vie active, le coût de la reproduction a été mesuré pour la première fois chez le hérisson, par calorimétrie indirecte. Le coût de la gestation peut atteindre une augmentation de +8% du cout de la maintenance chez la femelle, et le coût de la lactation, 3 fois plus. Après la reproduction, le hérisson prépare l'hibernation suivante. La méthode de dilution isotopique, utilisée pour la première fois chez le hérisson et la calorimétrie indirecte nous ont permis de montrer que l'animal abaisse son taux métabolique de repos afin de constituer des réserves. En conclusion, le mâle, avec une programmation stricte de l'activité, doit constituer des réserves suffisantes pour l'hibernation et la reproduction (préparation et accouplement). Chez les femelles, une programmation plus souple permet de réaliser les activités les plus couteuses (reproduction), seulement lorsque les conditions du milieu sont favorables
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Fatkhullin, Bulat. "Structural and functional studies of the ribosome silencing factor RsfS from the pathogenic bacteria Staphylococcus aureus." Electronic Thesis or Diss., Strasbourg, 2023. http://www.theses.fr/2023STRAJ018.
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Actuellement, en raison de l'utilisation active et parfois incontrôlée des antibiotiques, le nombre de souches de S. aureus présentant une résistance élevée aux médicaments antibactériens augmente chaque année. Les cellules persistantes jouent un rôle important dans ce processus. Même en l'absence de résistance aux antibiotiques, ces cellules survivent, provoquant des infections récurrentes, car elles ont bloqué les sites de liaison de la plupart des médicaments thérapeutiques affectant le ribosome de S. aureus. Par conséquent, la lutte contre les mécanismes cellulaires responsables de la transition des cellules vers un état persistant est une priorité pour la recherche. L'un de ces mécanismes est lié au fonctionnement du facteur RsfS. Dans cette étude, la première structure cryo-EM à résolution de 3.2 Å du complexe 50S et RsfS et la structure X-ray à résolution de 2.3 Å du complexe RsfS et uL14 ont été obtenues. La région de l'acide aminé Tyr 98 de RsfS est un site critique pour la préservation des fonctions anti-associatives du facteur RsfS de S. aureus. Les résultats obtenus dans ce projet pourraient servir de base au développement de nouveaux types de médicaments capables d'atténuer les propriétés pathogènes de S. aureusCurrently, due to the active and sometimes uncontrolled use of antibiotics, the number of S. aureus strains with high resistance to antibacterial drugs increases every year. Persister cells play an important role in this process. Even in the absence of antibiotic resistance, these cells survive, causing recurrent infections, since they have blocked the binding sites of most therapeutic drugs affecting the S. aureus ribosome. Therefore, combating the cellular mechanisms responsible for the transition of cells to a persister state is a priority for research. One such mechanism is related to the functioning of the RsfS factor. In this study, the first 3.2 Å resolution cryo-EM structure of the 50S and RsfS complex and X-ray 2.3 Å resolution structure of the RsfS and uL14 complex were obtained. The RsfS Tyr 98 amino acid region is a critical site for preserving the anti-associative functions of the S. aureus RsfS factor. The obtained in this work results could form the basis for the development of new types of drugs capable of attenuating the pathogenic properties of S. aureus
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Nicolai, Annegret. "The impact of diet treatment on reproduction and thermo-physiological processes in the land snails Cornu aspersum and Helix pomatia." Rennes 1, 2010. https://tel.archives-ouvertes.fr/tel-00525296.
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Organisms often encounter environmental heterogeneity in space and time, and may adapt their life histories. In Cornu aspersum reproductive strategy depended on seasonal time constraints, and the investment in reproduction was influenced by the energy available in the environment. Nutrients deposited in eggs might enhance offspring survival. In Helix pomatia that is used recently in low input snail farms in Germany to maintain this endangered species as a regional specialty under the name Albschneck®, showed low reproductive success even with high energy food. Helix pomatia preserves ice nucleating bacteria and accumulates cryprotectants to enhance cold hardiness during hibernation. Mortality could be related to perpetual physiological adjustments to high environmental variations but also be due to limited resource allocation to survival maintaining processesLes organismes rencontrent souvent de l’hétérogénéité dans l’espace et dans le temps et devront adapter leur traits d’histoire de vie. Chez Cornu aspersum, la stratégie de reproduction dépend des contraintes saisonnières, et l’investissement dans la reproduction est influencé par l’énergie disponible dans l’environnement. Des nutriments déposés dans les oeufs pourraient augmenter la probabilité de survie des juvéniles. Chez Helix pomatia, qui est utilisé dans des élevages biologiques afin de maintenir cette espèce menacée comme spécialité régionale sous le nom Albschneck®, le succès reproducteur est faible même avec une alimentation riche en énergie. Helix pomatia préserve des bactéries nucléantes dans l’intestin et accumule des cryoprotecteurs pour améliorer la résistance au froid pendant l’hiver. La mortalité pourrait être liée à un ajustement perpétuel des processus physiologiques aux importantes variations environnementales ainsi qu’à une allocation limitée vers des processus de survie
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Pasniciuc, Silviu Valeriu. "Complex mechanisms of metabolic regulation in nonperfused muscle." The Ohio State University, 2004. http://rave.ohiolink.edu/etdc/view?acc_num=osu1049304386.
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Boyer, Christian. "Identification et caractérisation de composés circulants d’intérêt dans le sérum d’ours brun hibernant – Étude des effets biologiques du sérum d’ours hibernant sur cellules humaines." Electronic Thesis or Diss., Université Clermont Auvergne (2021-...), 2023. http://www.theses.fr/2023UCFA0012.
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L’atrophie musculaire, qui constitue un enjeu majeur en matière de santé publique, est une affection qui touche les personnes âgées, mais aussi les personnes sédentaires, immobilisées ou souffrant d’une inflammation chronique. L’utilisation de modèles animaux, en particulier les rongeurs de laboratoire, a permis d’élucider les mécanismes moléculaires et physiopathologiques à l’origine de l’atrophie musculaire. Dans la recherche de solutions thérapeutiques, l’exploration d’un modèle de résistance naturelle à l’atrophie musculaire doit permettre d’ouvrir de nouvelles pistes de recherche innovantes. Le laboratoire explore comment l‘ours brun hibernant est capable de préserver son tissu musculaire durant plusieurs mois d’immobilité, et comment son sérum est capable d’induire des modifications de la balance protéique sur des cellules musculaires humaines. L’objectif principal de mon travail de thèse était d’identifier des composés ou familles de composés circulants chez l’ours en hibernation, et responsables d’effets biologiques sur des cellules humaines. Dans un premier temps j’ai recherché une activité biologique facilement mesurable, et qui pourrait être utilisée pour cribler les composés circulants. La mesure de l’activité NADH déshydrogénase par un test colorimétrique, permet de suivre les effets inhibiteurs du sérum et de ses fractions sur des cellules humaines en culture, de façon robuste et reproductible. Grace à cet outil, nous avons pu initier le criblage de plusieurs fractions issues du sérum d’ours hibernant, débutant ainsi une approche sans a priori dans la recherche des composés actifs du sérum d’ours hibernant. Ces travaux ouvrent la voie aux tests de nouvelles fractions, permettant d’avancer vers l’identification de nouvelles molécules ayant un effet positif sur la balance énergétique cellulaire. Selon la même démarche, le développement de plusieurs outils de mesure couvrant d’autres domaines du métabolisme cellulaire devrait permettre à l’avenir de compléter cette approche. En parallèle, dans la recherche de composés circulants actifs présent dans le sérum d’ours hibernant, j’ai axé mes recherches sur des composés en relation avec le système endocannabinoïde. J’ai pu ainsi mettre en évidence une diminution globale du tonus endocannabinoïde, avec une diminution des ligands de la voie canonique. De façon surprenante, la concentration d’oleoylethanolamide (OEA) circulante est multipliée par trois en hiver, suggérant un rôle important de ce composé dans la physiologie de l’hibernation chez l’ours brun. La poursuite de ces travaux doit permettre de mieux cerner les composés circulants d’intérêt pour la médecine humaine, et d’avancer vers des solutions thérapeutiques innovantes dans la lutte de certaines pathologies, comme l’atrophie musculaireMuscle atrophy, which is a major public health issue, is a condition that affects the elderly, but also people who are sedentary, immobilized or suffering from chronic inflammation. The use of animal models, in particular laboratory rodents, has made it possible to elucidate the molecular and physiopathological mechanisms at the origin of muscle atrophy. In the search for therapeutic solutions, the exploration of a model of natural resistance to muscle atrophy should open up new and innovative avenues of research. The laboratory is exploring how the hibernating brown bear is able to preserve its muscle tissue during several months of immobility, and how its serum is able to induce changes in the protein balance of human muscle cells. The main objective of my thesis work was to identify compounds or families of compounds circulating in the hibernating bear and responsible for biological effects on human cells. First, I looked for a biological activity that could be easily measured and that could be used to screen the circulating compounds. The measurement of NADH dehydrogenase activity by a colorimetric assay, allows to follow the inhibitory effects of serum and its fractions on human cells in culture, in a robust and reproducible way. Thanks to this tool, we were able to initiate the screening of several fractions from hibernating bear serum, thus starting an unbiased approach in the search for active compounds in hibernating bear serum. This work opens the way to the testing of new fractions, allowing to advance towards the identification of new molecules having a positive effect on the cellular energy balance. According to the same approach, the development of several measurement tools covering other domains of cellular metabolism should allow to complete this approach in the future. In parallel, in the search for active circulating compounds present in the serum of hibernating bears, I focused my research on compounds related to the endocannabinoid system. I was thus able to highlight a global decrease of the endocannabinoid tone, with a decrease of the ligands of the canonical pathway. Surprisingly, the concentration of circulating oleoylethanolamide (OEA) is multiplied by three in winter, suggesting an important role of this compound in the physiology of hibernation in brown bears. The continuation of this work should allow to better identify circulating compounds of interest for human medicine, and to advance towards innovative therapeutic solutions in the fight against certain pathologies, such as muscle atrophy
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Doherty, Alison H. "The Skeletal Biology of Hibernating Woodchucks (Marmota monax)." Kent State University / OhioLINK, 2013. http://rave.ohiolink.edu/etdc/view?acc_num=kent1355252380.
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Wiebler, James. "UREA HYDROLYSIS BY GUT BACTERIA: FIRST EVIDENCE FOR UREA-NITROGEN RECYCLING IN AMPHIBIA." Miami University / OhioLINK, 2018. http://rave.ohiolink.edu/etdc/view?acc_num=miami152535331130121.
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Mesa, Cruz Jose Bernardo. "Assessment of Physiological Challenges in Overwintering Black Bears (Ursus americanus): Active Gestation, Neonatal Growth, and Skeletal Muscle Conservation." Diss., Virginia Tech, 2018. http://hdl.handle.net/10919/96197.
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The American black bear (ABB) (Ursus americanus) exhibits physiological strategies highly synchronized with the environment. Such strategies enable bears to exploit food resources when available and survive the winter months by hibernating without ingesting food or water. However, there are multiple aspects of ABB hibernation physiology that remain unknown. For instance, there is conflicting evidence on the occurrence of ABB pseudopregnancy (a physiological state in which a non-pregnant bear exhibits progesterone levels similar to gravid bears in the absence of an actual pregnancy). Also, there is little known about postnatal development of cubs or the influence of maternal traits on embryonic implantation and cub growth. Finally, the role of satellite cells (SCs – stem cells able to regenerate muscle fibers) play in maintaining muscle functionality during hibernating remains understudied. Therefore, I aimed to assess these four aforementioned aspects using wild ABBs held temporarily captive at Virginia Tech's Black Bear Research Center (VT-BBRC). The major findings of this dissertation are: 1) I suggest that wild ABBs do not experience pseudopregnancy as a reproductive strategy; 2) interactions between litter size and cub age best described postnatal cub weight dynamics and organ development. Twin cubs were heavier than single and triplet cubs, yet cubs from all litter sizes reached similar weights after mothers began consuming food post hibernation. Single cubs experienced delayed timing in ear, eye, and teeth development compared to other litter sizes; 3) maternal traits such as higher body weight and higher ability to gain weight in the fall are closely associated with earlier timing of embryonic implantation than in leaner females, which gained less weight per day in the fall; and 4) SC ability to generate muscle fibers is increased during ABB hibernation. I propose that maintaining the SCs are an important potential pathway for limiting muscle atrophy during bear hibernation. Understanding pre and postnatal development of ABBs is important for exploring factors related to climate, maternal characteristics, which possibly affect birthing phenology, and fitness of bears experiencing rapid anthropogenic environmental change. Functional aspects of bear muscle conservation are interesting for potentially for elucidating avenues to improve treatments for human metabolic disorders such as muscular dystrophy, sarcopenia, and disuse atrophy.Ph. D.