L’étude proposée s’inscrit dans le cadre des recherches portant sur les fluctuations des performances attentionnelles dans le domaine de l’éducation, et plus précisément dans les écoles primaires. Elle a pour objectif de montrer, dans une perspective différentielle, l’impact du moment de la journée et des jours de la semaine sur les performances attentionnelles, d’une part, et sur les variations hebdomadaires des durées du sommeil d’autre part, selon l’âge, le sexe et l’origine géographique des enfants. L’attention et ses variations ont été évaluées à partir d’épreuves de barrage de nombres. Nous avons pu mesurer les variations attentionnelles dans deux pays : l’Irak et les Émirats Arabes Unis. Afin de pouvoir procéder à l’identification des performances, 223 élèves, dans deux pays arabes, dont 103 garçons et 120 filles, sont répartis selon deux niveaux d’études : CP (5-7 ans) et CM2 (10-12ans). Ces enfants sont soumis à des tests d’attention (barrage de nombres), à différents moments de la journée : quatre fois par jour (8h, 10h30, 11h, 13, aux Émirats Arabes Unis, et à 8h, 11h5, 11h25, 12h45 en Irak) et pendant les jours de classe: dimanche, lundi, mardi,mercredi, et jeudi. Pour étudier la durée du sommeil chez nos sujets nous avons utilisé un agenda du sommeil. On l’a mesurée pour les nuits de la semaine de l’expérimentation (samedi/ dimanche, dimanche/ lundi, lundi/ mardi, mardi/mercredi, mercredi/vendredi et vendredi/ samedi). Les résultats indiquent que les performances attentionnelles fluctuent différemment selon les moments de la journée et les jours de la semaine aussi bien chez les élèves de CP que ceux de CM2. Par ailleurs, les durées de sommeil nocturne fluctuent au cours de la semaine différemment selon l’emploi du temps hebdomadaire. Ces résultats viennent compléter les réflexions menées sur les moments propices pour une bonne réflexion, et permettent de souligner la place prépondérante de l’âge, du sexe, de l’origine géographique des élèves. En effet, ces données diffèrent selon l’origine géographique des élèves (pays moyen orient : Irak, Émirats Arabes Unis, d’une part, France, d’autre part) ou selon les emplois du temps proposé. / The proposed study appears with in the framework of the research concerned with the fluctuations of the attention performance in the field of education, specifically in the primary schools. It aims at showing, in a developmental and differential perspective, the impact of the moment of daily performance, and weekly variations of sleep duration, according to age, sex and geographic background of the children. In order to be able to conduct the identification of the performances, we are able to measure changes in attention in two countries namely: Iraq and the United Arab Emirates. In order to proceed with the identification of performances, 223 students in two Arab countries, including 103 boys and 120 girls, are divided into two age groups (CP (5-7 years), CM2 (10-12 years). These children are, in the same way to tests of attention (dam of numbers), given to tests of simulated conduct, at different moments of the day: four times a day, on different days of the week: Sunday, Monday, Tuesday, Wednesday and Thursday. To study the duration of sleep in our subjects we used a sleep diary. It was measured by the nights of the week of the experiment (Saturday / Sunday, Sunday / Monday / Tuesday, Tuesday / Wednesday, Wednesday / Friday and Friday / Saturday). The results indicate that attention performance fluctuates differently in various times of day and the day of the week as well as among students in CP than CM2. In addition, nighttime sleep durations fluctuate during the week differently depending on the weekly schedule. These results complete the reflections on the good moments for reflection, and can highlight the prominence of age, gender, geographic background of students, these data differ according to the geographic background of students (middle Eastern countries: Iraq, United Arab Emirates, on the one hand, France, on the other) or in the schedules proposed.

Thèse numérisée par la Direction des bibliothèques de l'Université de Montréal.

Hawaiian red shrimp - Halocaridina rubra (order Decapoda; family Atyidae) is an endemic species originated from Hawaii Islands. It is adapted to a specific environment of underground systems and anchialine pools. Halocaridina rubra has a great potential for aquarium shrimps breeders as well as for researchers. The aim of this work was to: (1) document the reproduction of shrimp Halocaridina rubra and (2) determine the influence of selected chronobiological factors and presence/absence of a shelter for its reproduction. The experiment was realized in the aquarium room and chronobiological laboratory at the department of Biological disciplines at the Faculty of Agriculture, University of South Bohemia in České Budějovice. The experiment took three months (i.e. from 3 rd November 2014 to 3 rd February 2015). This experiment had 4 treatments each with two repetitions: on the light with and without a shelter, in the dark with and without a shelter. Experimental shrimps were put into the aquaria in the breeding groups: 10: 16 (female: male). The frequency of mating was evaluated. Neither the light conditions (12 h (light): 12 h (dark) or permanent dark) nor the presence of shelter had impact on the reproduction of Halocaridina rubra. The reproduction of shrimp Halocaridina rubra was documented. Spermatophore transfer, eggs, four larval stages of zoea type, megalopal stage and two juvenil stages are monitored. Recommendations for breeding have been developed. Anesthesia was tested by using eugenol (clove oil) in shrimps.

Les efflorescences de la micro-algue toxique Alexandrium minutum sont en constante augmentation au niveau mondial, accentuées par les apports anthropiques et le réchauffement global, et posent des problèmes écologiques, économiques et sanitaires. Lors d’une exposition à A. minutum, l’accumulation des phycotoxines paralysantes (PSP) dans les tissus semble être différente entre les huîtres diploïdes et triploïdes. Par ailleurs, de nombreuses fonctions physiologiques de l’huître C. gigas sont impactées. L’ensemble des fonctions physiologiques d’un organisme est régulé par des rythmes biologiques. Propriété fondamentale de la vie, les rythmes biologiques permettent aux organismes de se synchroniser et d’anticiper les variations cycliques de l’environnement. Dans mes travaux, je me suis intéressée aux rythmes biologiques des huîtres diploïdes et triploïdes C. gigas et à leurs interactions avec la contamination par les PSP. Une analyse in situ sur un an a mis en évidence une relation jusque-là inconnue entre le comportement valvaire de C. gigas et le cycle d’éclairement de la lune, ainsi qu’une relation fine et subtile des cycles comportementaux nycthéméraux et tidaux avec l’évolution annuelle de la photopériode. Cette relation est modulée par la ploïdie. Par ailleurs, la mise au point d’une approche non-invasive d’interférence par ARN a permis de mettre en évidence l’implication de l’horloge circadienne dans les processus de bioaccumulation des PSP chez C. gigas. Enfin, l’analyse du transcriptome cyclique dans les branchies de C. gigas a mis en évidence qu’au moins 42 % du transcriptome peut être exprimé de façon oscillante. Contre intuitivement, en condition d’alternance jour / nuit, une majorité de transcrits sont ultradiens, trois fois plus nombreux que les transcrits circadiens. Exposées à A. minutum, les huîtres ont montré un remodelage profond de leur transcriptome cyclique, pouvant entraîner la perte de synchronisation de l’huître avec son environnement. / Harmful algal blooms of Alexandrium minutum are constantly increasing at the global level, accentuated by anthropogenic contributions and global warming, causing ecological, economical and sanitary problems. During exposition to A. minutum, paralytic phycotoxins (PSP) accumulation differs between diploid and triploid oysters. Moreover, many physiological functions of the oyster C. gigas are impacted. All physiological functions of an organism are regulated by biological rhythms. As a fundamental property of life, biological rhythms allow organisms to synchronize and anticipate cyclic variations of the environment. In my work, I was interested in the biological rhythms of diploid and triploid oysters C. gigas, and their interactions with PSP contamination. A one-year in situ analysis revealed a previously unknown relationship between valve behavior of C. gigas and the lunar illumination cycle, as well as a fine and subtle relationship of the nycthemeral and tidal behavioral cycles with the annual evolution of the photoperiod. This relationship was modulated by the ploidy. Moreover, the development of a non-invasive approach of RNA interference revealed the involvement of the circadian clock in bioaccumulation processes of PSPs in C. gigas. Finally, analysis of the cyclic transcriptome in the gills of C. gigas showed that at least 42 % of the transcriptome can oscillate. Surprisingly, in day / night entrainment, most of transcripts were ultradians, three times more abundant than circadian transcripts. Exposed to A. minutum, results showed a profound remodeling of the cyclic transcriptome of C. gigas, which could lead to loss of synchronization of the oyster with its environment.

Endogenous clocks regulate physiological as well as behavioral rhythms within all organisms. They are well investigated in D. melanogaster on a molecular as well as anatomical level. The neuronal clock network within the brain represents the center for rhythmic activity control. One neuronal clock subgroup, the pigment dispersing factor (PDF) neurons, stands out for its importance in regulating rhythmic behavior. These neurons express the neuropeptide PDF (pigment dispersing factor). A small neuropil at the medulla’s edge, the accessory medulla (AME), is of special interest, as it has been determined as the main center for clock control. It is not only highly innervated by the PDF neurons but also by terminals of all other clock neuron subgroups. Furthermore, terminals of the photoreceptors provide light information to the AME. Many different types of neurons converge within the AME and afterward spread to their next target. Thereby the AME is supplied with information from a variety of brain regions. Among these neurons are the aminergic ones whose receptors’ are expressed in the PDF neurons. The present study sheds light onto putative synaptic partners and anatomical arrangements within the neuronal clock network, especially within the AME, as such knowledge is a prerequisite to understand circadian behavior. The aminergic neurons’ conspicuous vicinity to the PDF neurons suggests synaptic communication among them. Thus, based on former anatomical studies regarding this issue detailed light microscopic studies have been performed. Double immunolabellings, analyses of the spatial relation of pre- and postsynaptic sites of the individual neuron populations with respect to each other and the identification of putative synaptic partners using GRASP reenforce the hypothesis of synaptic interactions within the AME between dopaminergic/ serotonergic neurons and the PDF neurons. To shed light on the synaptic partners I performed first steps in array tomography, as it allows terrific informative analyses of fluorescent signals on an ultrastructural level. Therefore, I tested different ways of sample preparation in order to achieve and optimize fluorescent signals on 100 nm thin tissue sections and I made overlays with electron microscopic images. Furthermore, I made assumptions about synaptic modulations within the neuronal clock network via glial cells. I detected their cell bodies in close vicinity to the AME and PDFcontaining clock neurons. It has already been shown that glial cells modulate the release of PDF from s-LNvs’ terminals within the dorsal brain. On an anatomical level this modulation appears to exist also within the AME, as synaptic contacts that involve PDF-positive dendritic terminals are embedded into glial fibers. Intriguingly, these postsynaptic PDF fibers are often VIIAbstract part of dyadic or even multiple-contact sites in opposite to prolonged presynaptic active zonesimplicating complex neuronal interactions within the AME. To unravel possible mechanisms of such synaptic arrangements, I tried to localize the ABC transporter White. Its presence within glial cells would indicate a recycling mechanism of transmitted amines which allows their fast re-provision. Taken together, synapses accompanied by glial cells appear to be a common arrangement within the AME to regulate circadian behavior. The complexity of mechanisms that contribute in modulation of circadian information is reflected by the complex diversity of synaptic arrangements that involves obviously several types of neuron populations / Endogene Uhren steuern sowohl physiologische als auch verhaltensbedingte Rhythmen bei allen Organismen. In D. melanogaster sind sie nicht nur auf molekularer sondern auch auf anatomischer Ebene bereits gut erforscht. Das neuronale Uhrnetzwerk im Gehirn stellt das Zentrum der Steuerung der rhythmischen Aktivität dar. Eine Uhrneuronengruppe sticht allein schon durch ihre besonderen anatomischen Eigenschaften hervor. Diese Neurone exprimieren das Neuropeptid PDF (pigment dispersing factor), welches zudem besonderen Einfluss auf die Lokomotionsaktivität der Fliege hat. Ein kleines Neuropil am Rande der Medulla, die akzessorische Medulla (AME) ist von besonderem Interesse, da neben seiner intensiven Innervation durch die PDF-Neurone auch Terminale aller anderen Uhrneuronengruppen zu finden sind. Zudem wird sie durch Terminale der Photorezeptoren mit Informatonen über die Lichtverhätnisse versorgt. Die AME erreichen des Weiteren Informationen aus vielen anderen Hirnregionen. Eine Vielzahl von Neuronentypen laufen in ihr zusammen, um sich anschließend wieder in verschiedenste Hirnareale zu verteilen. So wird die AME auch durchzogen von Fasern mit aminergem Inhalt, dessen Rezeptoren wiederum auf den PDF-Neuronen zu finden sind. Die vorliegende Arbeit gibt Aufschluss über vermutliche synaptische Partner und anatomische Anordnungen innerhalb des neuronalen Uhrnetzwerkes, insbesondere innerhalb der AME. Solch Wissen stellt eine Grundvoraussetzung dar, um zirkadianes Verhalten verstehen zu können. Die auffällige Nähe der aminergen Neurone zu den PDF Neuronen lässt eine synaptische Interaktion zwischen ihnen vermuten. Deshalb wurden basierend auf vorangegangen Studien detailiertere Untersuchungen dieser Thematik durchgeführt. So wird die Hypothese über synaptische Interaktionen innerhalb der AME zwischen dopaminergen/ serotonergen Neuronen und den PDF Neuronen bestärkt mittels Doppelimmunofärbungen, gegenüberstellende Analysen über die räumlichen Nähe von prä- und postsynaptischen Stellen der jeweiligen Neuronenpopulationen und durch die Identifikation vermutlicher synaptischer Partner unter Verwendung von GRASP. Zur möglichen Identifikation der synaptischen Partner unternahm ich erste Schritte in der Array Tomographie, welche hochinformative Analysen von fluoreszierenden Signalen auf einem ultrastrukturellen Level ermöglicht. Dazu testete ich verschieden Wege der Gewebepräparation, um Flureszenzsignale zu erhalten bzw. zu optimieren und bildete erste Überlagerungen der Fluoreszenz- und Elektronenmikrskopbilder. Die Auswertung der elektronenmikroskopischen Bilder erlaubten Mutmaßungen über mö- gliche synaptische Modulationen innerhalb des neuronalen Uhrnetzwerkes durch Gliazellen. Ihre Zellkörper fand ich in unmittelbarer Nähe zu den PDF Neuronen. Im dorsalen Hirn wurden neuronale Modulationen an den kleinen PDF Neuronen durch Gliazellen bereits festgestellt. Auf anatomischer Ebene scheint diese Modulation auch innerhalb der AME zu erfolgen, da synaptische Kontakte, welche PDF-positive Dendriten involvieren, von Gliafasern umgeben sind. Interessanterweise sind diese postsynaptischen PDF Fasern dabei oftmals Teil dyadischer oder sogar multipler Kontakte, die sich gegenüber einer ausgedehnten aktiven Zone befinden. Um mögliche Mechanismen solcher synaptischer Anordnungen zu erklären, versuchte ich den ABC Transporter White im Hirn von Drosophila zu lokalisieren. Seine Präsenz in Gliazellen würde auf einen Recyclingmechanismus hindeuten, welcher eine schnelle Wiederbereitstellung des Transmiters ermöglichen würde. Zusammengefasst scheinen Synapsen mit postsynaptischen PDF-Neuronen in Begleitung von Gliazellen, ein gebräuchliches synaptisches Arrangement innerhalb der AME dazustellen. Diese komplexe Diversität der synaptischen Anordnung reflektiert die komplexen Mechanismen, welche der Verarbeitung der zirkadianen Informationen zugrunde liegen

L'objectif principal de ma thèse est l’exploration de l’impact clinique d’une perturbation du système circadien chez les patients cancéreux. J’ai démontré une relation robuste entre le rythme d'activité-repos et survie, symptômes et qualité de vie. J’ai mis en évidence et caractérisé la dynamique du système circadien des patients sous chimiothérapie. J’ai montré qu’une bonne tolérance conditionnait l’efficacité de la chronothérapie. Ces résultats me conduisent à proposer de cibler le système circadien pour améliorer les symptômes des patients et l’efficacité des traitements anticancéreux. / The circadian timing system controls several temporal aspects of physiology and behaviour in laboratory animals and humans. The disruption of the circadian timing system results in the occurrence of alterations at various levels of organisation: central coordination, circadian physiology, molecular clocks and signalling pathways. In particular, a circadian disruption induced by long-haul flights across several time-zones or by shift work is associated with the appearance of systemic symptoms, such as fatigue, mood disorders and appetite loss. These symptoms, related to circadian disruption, are also frequently found in cancer patients, as a consequence of their neoplastic disease or its treatment. My PhD work is part of the research regarding the role of the circadian timing system in the development of the symptoms associated with cancer and its treatment, in tumor progression and in patients’ survival. Its perspective is to identify novel therapeutic options. In particular, the general objectives of this thesis consist in the definition of the relationships between symptoms and circadian function of patients before and during chemotherapy, and in the quantification of the clinical impact of circadian disruption on quality of life and survival. I have focused in particular on patients with metastatic colorectal cancer, third cancer for incidence and mortality. These studies confirm the role of the circadian timing system in the occurrence of systemic symptoms in cancer patients, without treatment or during it. This study is currently ongoing in collaboration with the NIH in the United States. In conclusion, this work leads me to propose an innovative therapeutic approach aimed at shielding and/or restoring the integrity of the circadian timing system. This novel strategy should improve the therapeutic index of chemotherapy, by increasing its efficacy and decreasing its toxicity, still reducing the occurrence of symptoms, preserving the quality of life and prolonging the survival of cancer patients. The implementation of this strategy relies on the non-invasive monitoring of biomarkers of the circadian timing system and on the personalization of chronotherapy delivery.

This thesis deals with monitoring changes of body weight of adolescent girls at the age of 16 20 years old through one calendar year in the context of a season of the year and chronotypology of a personality. According to this typology the monitored people are divided into so called "larks", who are more active early in the morning and during the day and "owls" whose activity rises in the evening and at night. The theoretical part deals with circadian rhythms, their function, role in the life of an individual and also their disorders. It focuses on a developmental specification of adolescent girls, lifestyle in this period of life, changes of body weight and diet. Another part is the meaning of the sleep, its need and associated with good sleep habits and sleep hygiene. In the practical part there is described a methodology along with the results of the research and employment of this project in practice.

Introduction: Pineal region is a deep-seated part of the brain surrounded by highly eloquent structures. Differential diagnosis of space-occupying lesions in this region encompasses pineal gland cysts, pineal gland tumours, metastases, germ cell tumours, meningiomas, gliomas, hemangioblastomas and neuroectodermal tumours. In this thesis, I focused mainly on patients with pineal cysts, which is a benign affection of the human pineal gland on the borderline between pathology and normality. The clinical management of patients with a pineal cyst remains controversial, especially when patients present with non-specific symptoms. A melatonin secretion in patients with a pineal cyst before and after a pineal cyst resection has not been studied yet and the effect of surgery on human metabolism is unknown. Materials and Methods: We performed a prospective study between 2000 and 2016. All patients with a pineal cyst larger than 7 mm were included. Epidemiological data, presenting symptoms, surgical results and radiographic and clinical follow-up were documented. We examined melatonin, cortisol and blood glucose secretion profiles perioperatively in a subgroup of 4 patients. The control group was represented by 3 asymptomatic patients with a pineal cyst. For each patient, 24-h circadian secretion curves of...

L’étude présentée porte sur les niveaux et les variations des performances journalières et hebdomadaires de l’attention chez les enfants Chinois du Cours Préparatoire et du Cours Moyen deuxième année en situation scolaire. Et plus précisément chez les enfants de 6 à 7 ans et de 10 à 12 ans. Elle a pour objectif de démontrer, d’une part, dans une approche interculturelle et différentielle, l’effet des moments dans la journée et des jours de la semaine ainsi que les durées du sommeil sur les performances attentionnelles et les comportements scolaires des enfants selon leur ’âge, le niveau scolaire et l’origine géographique. D’autre part, l’incidence des lieux de vie (rural /urbain) sur la rythmicité scolaire. / The introduced study appears in the framework of the research concerned with the levels and variations of the attention performance of Chinese children in CP and CM2 of primary school, specifically the children of 6 to 7 and 10 to 12 years old. It aims at showing, on the one hand, in an intercultural and differential approach, the effect of the moment of daily performance and weekly performance, as well as weekly variations of sleep duration according to age, educational level and geographic background of the children. On the other hand, the impact of life place (city/ country) on the school timetables.

L’ensemble de ce travail doctoral avait pour objectif d’optimiser les effets des programmes d’activités physiques pour prévenir les chutes chez les personnes âgées institutionnalisées. Le contrôle postural et la locomotion étant fondamentaux dans la prévention des chutes, il convient de les stimuler régulièrement par une pratique physique adaptée. Par ailleurs, l’amélioration de la sensibilité cutanée plantaire peut permettre d’améliorer le contrôle postural et la locomotion. Même si les bénéfices potentiels d'une stimulation des afférences cutanées plantaires par la pratique d’exercices pieds nus sont multiples, l’intérêt de cette modalité de pratique des activités physiques à destination des personnes âgées reste à démontrer. Deux groupes de personnes âgées ont ainsi dû suivre le même programme d’activités physiques, pieds-nus pour un groupe et en portant des chaussures pour l’autre groupe. Les principaux résultats ont révélé qu’un programme d’activités physiques pratiqué pieds nus améliorait davantage la sensibilité cutanée plantaire et le contrôle postural qu’un programme pratiqué avec des chaussures. Malgré l’avancée en âge, le système sensori-moteur semble toujours bénéficier d’une certaine plasticité. Ce système sensori-moteur peut être stimulé en sollicitant notamment les mécanorécepteurs cutanés plantaires. Les effets d’un programme d’activités physiques peuvent également être optimisés en plaçant les séances au moment de la journée le plus approprié. En évaluant l’influence du moment de pratique au cours de la journée, nous avons pu montrer qu’un programme d’activités physiques réalisé l’après-midi provoquait des effets positifs plus marqués qu’un programme réalisé le matin. De manière surprenante, le contrôle postural des sujets qui s’entraînaient l’après-midi s’améliorait principalement le matin, au moment de la journée où il est le plus efficace chez les personnes âgées. Ces adaptations seraient en phase avec le moment de la journée où les fonctions cognitives sont également optimales, c’est-à-dire le matin. / The main purpose of these researches was to optimize the effects of physical activity programs to prevent falls among institutionalized older adults. Postural control and gait are essential in preventing falls and should be regularly promoted by an appropriate physical practice. In addition, improving plantar cutaneous sensitivity can improve postural control and gait. Even though there are further potential benefits of stimulating plantar afferences by performing barefoot exercises, the effects of this modality of physical activity for the elderly remains unclear. Two groups of older adults were involved in the same physical activity program, barefoot for one group and while wearing shoes for the other. The main results revealed that a program of physical activity with barefoot exercises improved plantar cutaneous sensitivity and postural control to a greater extent than while wearing shoes. Despite advancement of aging, the sensorimotor system still seems to benefit from plasticity which can be stimulated by exercising barefoot and increasing somatosensory information from the foot. The time of day when people exercise can also influence the optimization of physical performance and enhance the effectiveness of a physical activity program. By assessing the influence of exercising at different times of day, we showed that training in the afternoon provided greater benefits on postural control than morning training. Surprisingly, postural control was mainly improved in the morning and did not improve when participants exercised in the morning. The postural control system would have benefited from an enhanced motor potential (acquired through afternoon training which optimized the musculoskeletal adaptations) only at the time of day when cognitive functions are optimal, i.e., in the morning.