La compréhension des propriétés biomécaniques de la tête du nerf optique (TNO) est cruciale pour la gestion de conditions telles que le glaucome et le Syndrome Neuro-Oculaire Lié à l'Espace (SNOE). Cette thèse propose d’utiliser l'imagerie par tomographie de cohérence optique vidéo à haute fréquence (V-OCT) traitée avec des algorithmes de traitement d'image existants pour évaluer quantitativement la déformation pulsatile de la TNO due aux cycles cardiaques. Cette méthode est utilisée afin d’investiguer deux phénomènes: la réponse biomécanique de la TNO dans les conditions terrestres; et la réponse du TNO dans l'environnement de microgravité de l'espace. Le premier segment de cette thèse présente une nouvelle méthode non-invasive pour mesurer le déplacement pulsatile de la TNO via l'OCT vidéo (V-OCT), offrant des progrès significatifs dans la quantification des propriétés biomécaniques de l'œil in vivo. Une validation approfondie de cette technique, à la fois numérique et expérimentale, a confirmé la sensibilité de l'algorithme aux déformations induites, sa robustesse face à divers niveaux de bruit, et sa répétabilité. Deux groupes d’individus, sains et myopes, ont été évalués sous différentes conditions de contrainte physiologique. La déformation pulsatile des tissus de la TNO a été capturée quantitativement et représentée sous forme de cartes de déformation, montrant la sensibilité de la méthodologie aux déformations induites et la robustesse aux interférences de bruit élevé. Pour les sujets dont les yeux ont une longueur axiale de moins de 25mm, des différences notables de déformation pulsatile médiane ont émergé entre les positions primaires et en abduction de l'œil, avec une reproductibilité confirmée via des coefficients de corrélation intra-classe élevés. Ayant validé la méthode, elle a donc a été appliquée à une cohorte de glaucomateux pour examiner l'impact de la réduction de la pression intraoculaire (PIO) sur le déplacement pulsatile de la TNO. Chez les patients atteints de glaucome primaire à angle ouvert (GPAO), en particulier ceux sans myopie axiale, les interventions abaissant la PIO ont conduit à une réduction significative de la pulsation de la TNO. Cependant, les patients glaucomateux myopes n'ont affiché aucun changement substantiel, suggérant une relation nuancée entre la modulation de la PIO et la biomécanique de la TNO. Une étude de cohorte n’a révélé aucune différence marquée dans la pulsation de la TNO à travers divers degrés de gravité du glaucome. Pourtant, la déformation pulsatile a été corrélée à l'épaisseur de la couche de fibres nerveuses rétiniennes et à des mesures hémodynamiques spécifiques, soulignant les interconnexions complexes entre la biomécanique et l'hémodynamique oculaires. La dernière partie de cette thèse aborde les modifications de la rigidité oculaire chez les astronautes avant et après des vols spatiaux prolongés. En analysant les données de 26 yeux de 13 astronautes, la recherche a démontré des réductions significatives de la rigidité oculaire, de la pression intraoculaire et de l'amplitude du pouls oculaire après la mission. Ces découvertes explorent des effets précédemment inconnus de la microgravité sur les propriétés mécaniques de l'œil, améliorant notre compréhension du SNOE. Cette étude, tout en approfondissant notre compréhension des complexités biomécaniques et hémodynamiques de la TNO, démontre le potentiel du V-OCT comme outil pour le diagnostic et le suivi des conditions du nerf optique. Les techniques et les perspectives acquises ici posent également les bases pour de futures explorations prometteuses à la fois pour les patients atteints de glaucome et pour les astronautes. / The eye is a semi-rigid sphere with complex biomechanical properties. Chronic disease or stress like space flight can interfere with these properties, leading to vision loss. Noninvasive measurements of the biomechanical properties of the optic nerve head (ONH) could provide better tracking and management of conditions such as glaucoma and Space-Related Neuro-Ocular Syndrome (SANS). This thesis proposes to use high-frequency optical coherence tomography video imaging (V-OCT) with existing image processing algorithms to quantitatively evaluate the pulsatile displacement of the ONH due to cardiac cycles. This methodology is applied across two streams of research: examining the ocular biomechanical response of the ONH under terrestrial conditions; and the ONH deformation in the microgravity environment of space. The first section of this thesis introduces a non-invasive method to measure ONH pulsatile displacement via video-based OCT (V-OCT), quantifying biomechanical eye properties in vivo. A thorough validation of this technique, both numerically and experimentally, confirmed the algorithm’s sensitivity to induced deformation, robustness against various noise levels, and repeatability. Two groups, healthy and myopic individuals, underwent assessment under different physiological strain conditions. Pulsatile ONH tissue deformation was quantitatively captured and represented as deformation maps. For those subjects with eyes with an axial length of less than 25mm, notable median pulsatile displacement differences were found between primary and abducted eye positions. Reproducibility was confirmed via high intraclass correlation coefficients. Building on this foundation, the method was applied to a cohort of glaucoma patients to examine the impact of IOP reduction on ONH pulsatile displacement. In primary open-angle glaucoma (POAG) patients, particularly those without axial myopia, IOP-lowering interventions significantly reduced ONH pulsation. However, myopic glaucoma patients displayed no substantial changes, suggesting that myopic status moderates the relationship between IOP modulation and ONH biomechanics. This pilot study was expanded to a larger cross-sectional cohort study (N=176), revealing a decrease in ONH pulsatile displacement in people with early and moderate glaucoma compared to controls. . In addition, pulsatile displacement correlated with retinal nerve fiber layer thickness and specific hemodynamic measures, showing that ocular biomechanics and hemodynamics are closely linked. The last section of the thesis investigates ocular rigidity alterations in astronauts before and after extended space flights. Analyzing data from 26 eyes of 13 astronauts, significant reductions in ocular rigidity were observed; similarly, intraocular pressure and ocular pulse amplitude were reduced post-mission. These findings reveal previously undocumented microgravity effects on the eye's mechanical properties, improving our comprehension of SANS. This thesis demonstrates the potential of V-OCT as a tool for the diagnosis and assessment of the progression of optic nerve conditions. By gaining a deeper understanding of the biomechanical and hemodynamic intricacies of the ONH, we lay the groundwork for future explorations that hold promise for both glaucoma patients and astronauts.

This study aims to analyze factors and individual characteristics that affect the outcomes:work-life balance, work engagement and sense of coherence for white-collar workers whenworking remotely. In today’s society where technology is constantly evolving, hybrid and remote work optionsare becoming more common. Research has shown that work-life balance, work engagement,and sense of coherence affect employee well-being and organizational performance. Theresearch on the extent to which remote work can contribute to sustainable work andemployee well-being is mixed, and most of the research on remote work has been conductedeither before or during the COVID-19 pandemic. Further post-pandemic research cancontribute to more sustainable work and society as a whole. To analyze what factors affect the outcomes in a remote work setting, a mixed-methodapproach was used to gain a comprehensive understanding, including a quantitative and aqualitative study. The quantitative method included bivariate correlation tests, multiple linearregression and group difference testing on cross-sectional survey data collected from twolarge Swedish companies. The qualitative method included six interviews with experiencedwhite-collar workers, which helped us interpret the findings and gain a more in depthunderstanding of quantitative results. To analyze the study findings the theoretical model ofhuman, technology, and organization (HTO) was applied. The quantitative study showed that social support from superiors, remote leadership quality,functionality of digital management systems and digital learning climate were identified asfactors that were associated with work-life balance, work engagement and sense ofcoherence. However, digital resources and social support from superiors were found to beinfluencing work engagement and sense of coherence to a greater extent. For work-lifebalance, social support from superiors and remote leadership quality was found to besignificant. The qualitative study showed that the interviewees' perception of work-lifebalance, work engagement, and sense of coherence was affected by flexible workingarrangements, functionality and use of digital tools, social interaction, collaboration,communication, inspirational relationships at the workplace, supportive colleagues, andsupportive and responsive superiors. Better understanding of what factors affect employees'personal and working life when working remotely can help organizations to promoteoccupational well-being and performance, which can contribute to more sustainable work. / Denna studie syftar till att analysera faktorer och individuella egenskaper som påverkarutfallen: balans mellan arbete och privatliv, arbetsengagemang och känsla av sammanhangför tjänstemän som arbetar på distans. I dagens samhälle där tekniken ständigt utvecklas, blir hybrid- och distansarbeten alltvanligare. Forskning har visat att balans mellan arbete och privatliv, arbetsengagemang ochkänsla av sammanhang påverkar medarbetarnas välbefinnande och organisatorisk prestation.Forskningen om i vilken utsträckning distansarbete kan bidra till hållbart arbete ochmedarbetarnas välbefinnande är blandad, och det mesta av forskningen om distansarbete harbedrivits antingen före eller under COVID-19-pandemin. Ytterligare postpandemiskforskning kan bidra till ett mer hållbart arbete och samhället. För att analysera vilka faktorer som påverkar utfallen i distansarbete användes en blandadmetod för att få en övergripande förståelse, inklusive en kvantitativ och en kvalitativ studie.Den kvantitativa metoden inkluderade bivariata korrelationstester, multipel linjär regressionoch tester av gruppskillnader. Tvärsnittsdata samlades in från två stora svenska företaggenom en enkät. Den kvalitativa metoden inkluderade sex intervjuer med erfarna tjänstemänoch hjälpte oss att tolka utfall och få en mer djupgående förståelse av kvantitativatestresultat. För att analysera studiens resultat användes den teoretiska modellen förmänniska, teknologi och organisation (MTO). Den kvantitativa studien visade att socialt stöd från överordnade, ledarskapskvalitet pådistans, funktionalitet av digitala ledningssystem och digitalt lärandeklimat identifieradessom faktorer som korrelerade med utfallen. Digitala resurser och socialt stöd frånöverordnade visade sig dock ha en större förknippning med faktorerna som påverkararbetsengagemang och känsla av sammanhang. För balans mellan arbete och privatliv varsocialt stöd från överordnade och ledarskapskvalitet på distans betydande. Den kvalitativastudien visade att intervjupersonernas uppfattning om balans mellan arbete och privatliv,arbetsengagemang och känsla av sammanhang påverkades av flexibla arbetsarrangemang,funktionalitet och användning av digitala verktyg, social interaktion, samarbete,kommunikation, inspirerande relationer på arbetsplatsen, stödjande kollegor, samt stödjandeoch lyhörda överordnade. Bättre förståelse för vilka faktorer som påverkar anställdaspersonliga liv och arbetsliv när de arbetar på distans kan hjälpa organisationer att främjayrkesmässigt välbefinnande och prestation, vilket kan bidra till ett mer hållbart arbete.

In der vorliegenden Promotionsarbeit werden optische Eigenschaften von Halbleiterquantengräben untersucht, die mit der Ausbildung von Speckle-Mustern in der exzitonischen Emission zusammenhängen. Die in nichtspekulärer Richtung nach resonanter Anregung von Exzitonen ausgestrahlte Emission enthält Informationen über Unordnung und Streuprozesse in der Probe. Im Kapitel "Spektrale Speckle-Analyse" wird gezeigt, dass Speckles zur Bestimmung des koährenten Anteils verwendet werden können. Außerdem kann die innerhalb des inhomogen verbreiterten Ensembles frequenzaufgelöste Lebensdauer der Exzitonen bestimmt werden. Eine mikroskopische Dichtematrixtheorie wird entwickelt und numerisch gelöst. Es wird eine gute Übereinstimmung mit den gemessenen Daten für unterschiedliche Quantengraben-Dicken und Temperaturen gefunden. Im Kapitel "Schrägliegende Speckles" werden Quantengräben mit mechanischer Verzerrung betrachtet. Die Verzerrung führt zu einer ort-abhängigen Änderung der Emissionsenergie in der Ebene des Quantengrabens und das richtungs- und zeitaufgelöste Specklemuster erfährt eine Drehung. Die theoretische Beschreibung des Rayleigh-Spektrums erlaubt es, diese Drehung mit dem lokalen Wert des Gradienten der Exzitonenergie in Beziehung zu setzen. Numerische Simulationen zeigen allerdings, dass dieser Effekt nicht durch eine Bewegung der Exzitonen entlang des Verzerrungs-Gradienten verursacht wird. Im Kapitel "Nicht-Markovsche Exziton-Phonon Dynamik" die Dichtematrixtheorie, wird jenseits der Markovschen Näherung für die Streuung von Exzitonen an akustischen Phononen numerisch gelöst. Das Absorptionsspektrum besteht aus Lorentz-formige Peaks und breiteren Seitenbändern, die aus der nicht-Markovschen Kopplung stammen. Diese Eigenschaften sind vor allem für die stark lokalisierten Zustände auf der Niederenergie-Seite des Spektrums wichtig, und erlauben eine bessere Deutung von Nahfeld-Experimenten. / In this work, optical properties of semiconductor quantum wells (QW) are investigated, which are relevant for the irregular light pattern (speckle pattern) emitted in nonspecular directions by QW after resonant excitation of the exciton states. This emission contains information on disorder and scattering processes in the sample. In Chapter "Spectral Speckle Analysis", it is shown that Speckles can be used for extraction of the coherent part of the emission, the Resonant Rayleigh Scattering. Furthermore, the frequency resolved lifetime of excitons within an inhomogeneously broadened ensemble can be established. A microscopic density matrix theory for excitons interacting with acoustic phonons is developed and numerically solved. Good agreement with the experimental results for different QW sizes and temperatures is found. In Chapter "Sloped Speckles" QW with mechanical strain are considered. The strain leads to a spatially dependent modification of the emission energy and to a tilting of the direction- and time-resolved speckle pattern. The theoretical description of the RRS relates this tilting to the local value of the spatial gradient of the exciton energy. However, numerical simulations make clear that this effect is not due to exciton motion along the strain gradient. In Chapter "Non-Markovian exciton-phonon dynamics" the density matrix theory is numerically solved beyond the Markov approximation for the interaction between excitons and acoustical phonons. The resulting absorption spectrum consists of Lorentzian peaks on top of broader sidebands originating from the non-Markovian coupling. These features are mostly important for the strongly localized states in the low energy side of the spectrum, suggesting a better interpretation of near-field experiments.

This dissertation is devoted to study of complex systems in human physiology particularly heartbeats and brain dynamics. We have studied the dynamics of heartbeats that has been a subject of investigation of two independent groups. The first group emphasized the multifractal nature of the heartbeat dynamics of healthy subjects, whereas the second group had established a close connection between healthy subjects and the occurrence of crucial events. We have analyzed the same set of data and established that in fact the heartbeats are characterized by the occurrence of crucial and Poisson events. An increase in the percentage of crucial events makes the multifractal spectrum broader, thereby bridging the results of the former group with the results of the latter group. The crucial events are characterized by a power index that signals the occurrence of 1/f noise for complex systems in the best physiological condition. These results led us to focus our analysis on the statistical properties of crucial events. We have adopted the same statistical analysis to study the statistical properties of the heartbeat dynamics of subjects practicing meditation. The heartbeats of people doing meditation are known to produce coherent fluctuations. In addition to this effect, we made the surprising discovery that meditation makes the heartbeat depart from the ideal condition of 1/f noise. We also discussed how to combine the wave-like nature of the dynamics of the brain with the existence of crucial events that are responsible for the 1/f noise. We showed that the anomalous scaling generated by the crucial events could be established by means of a direct analysis of raw data. The efficiency of the direct analysis procedure is made possible by the fact that periodicity and crucial events is the product of a spontaneous process of self-organization. We argue that the results of this study can be used to shed light into the nature of this process of self-organization.

The object of development is the code for working with the architecture of the Mask R-CNN convolutional neural network for segmentation of anomalies caused by cicatricial and wet forms of age-related macular degeneration in optical coherence tomography images. The purpose of the work is to write code for segmentation of anomalies in optical coherence tomography images. The paper considers the signs that determine the form of the disease that can be detected in an optical coherence tomography image, the stages of development of the architectures of neural networks of the R-CNN family, the OCTDL dataset containing optical coherence tomography images for several types of retinal diseases. An algorithm for multi-class segmentation of retinal anomalies caused by cicatricial and wet forms of age-related macular degeneration is written in the Python programming language. / Объектом разработки является код для работы с архитектурой свёрточной нейронной сети Mask R-CNN для сегментации аномалий, вызванных рубцовой и влажной формами возрастной макулярной дегенерации на снимках оптической когерентной томографии. Цель работы – написание кода для сегментации аномалий на снимках оптической когерентной томографии. В работе рассмотрены признаки, определяющие форму заболевания, которые можно обнаружить на снимке оптической когерентной томографии, этапы развития архитектур нейронных сетей семейства R-CNN, набор данных OCTDL, содержащий снимки оптической когерентной томографии по нескольким типам заболеваний сетчатки глаза. На языке программирования Python написан алгоритм для многоклассовой сегментации аномалий сетчатки, вызванных рубцовой и влажной формами возрастной макулодистрофии.

This qualitative study examines an asynchronous online course from a private university utilizing a template model for all online courses to provide students with consistent navigation and course structure throughout their degree program. The asynchronous online courses are purposely created using three criteria of quality course design: navigation is intuitive, information is chunked, and instructions are written clearly. A two-part usability test was conducted with three internal and three external participants. The two-part usability test focused on course navigation and examined the signaling, segmenting, and coherence principles applied to course content page layouts. Transcripts from the usability tests and observational field notes were coded through an iterative process in Nvivo. Through emic and etic coding, seven main categories were identified: user experience, cognitive load, multimedia learning principles, page design and layout attributes, course navigational attributes, course attributes and information, and participant navigational behavior. The findings for first-day navigation, general navigational behaviors, and perceptions of design elements used to implement the signaling, segmenting, and coherence principle are discussed. Course design recommendations for creating a positive usability experience and suggestions for future research are provided.

In this case study four non-fiction books are being accompanied on their way from the Netherlands to the public in Sweden, that is from one peripheral language into another. Where did the initiative come from? Were there any subsidies and did that matter? What kind of publishers were involved and were there also other agents involved? Who were the most important cultural mediators? How were the books framed in order to be noticed in the new country? How does all this fit in with the sociological theory of transnational cultural transfer? It turned out that these books more or less followed the expected path with a few exceptions: Two of the books were published by large-scale publishers in Sweden although they had not proved to be successful in the Netherlands. And there were no signs of regular co-operation between the involved publishers. Obviously the translated Dutch books in Sweden are such a marginal business for these publishers that they do not influence their network of foreign publishers.  Even if all four books belong to the same genre, they are very differently framed to be noticed in their new country.

La thèse se propose d’abord de redéfinir la notion de conversion. L’analyse du droit positif montre que la définition classique de la conversion, comme l’opération qui consiste à tirer d’un acte nul un acte nouveau valable, peut s’élargir à un double point de vue. On ne s’était occupé que de la conversion des actes juridiques ; on a découvert qu’elle peut être étendue aux actes instrumentaires. Dans le même sens, on n’avait envisagé qu’une cause de la conversion, la nullité d’un acte ; on admet aujourd’hui qu’elle pouvait opérer à la suite d’une cause survenant a posteriori, à l’instar de la caducité, la prescription, la forclusion et la résolution. La conversion peut, dès lors, être définie comme la technique qui donne effet, par la volonté de la loi ou du juge, à un acte juridique, qui n’a pu se former, à cause d’un vice originaire, ou qui n’a pu survivre, en raison d’une cause survenant a posteriori, lorsque les éléments qui demeurent correspondent à la définition d’une figure juridique nouvelle, satisfaisant l’objectif économique poursuivi par les parties.La thèse se propose également de moderniser ou de rénover le régime de la conversion. La conversion modernisée exige l’intervention active du juge pour vérifier que les conditions de la conversion sont réunies, mais aussi et surtout pour se prononcer sur son opportunité. La conversion place de la sorte le juge au rang de véritable formateur ou de « faiseur» du contrat. Les analyses doctrinales qui présentent la conversion comme reposant sur une prétendue volonté virtuelle des parties sont artificielles. Il n’y a pas cependant lieu de diaboliser l’office du juge en prétendant que la conversion est un procédé exorbitant et autoritaire. Les inquiétudes que peut faire naître l’accroissement du rôle du juge dans la conversion s’apaisent dès lors que le juge est tenu de puiser les éléments de l’acte nouveau dans l’acte initial. Elles doivent encore être tempérées par la recherche constante d’un acte nouveau qui répond au but initialement voulu par les parties.L’ambition de cette thèse était donc double : la redéfinition de la notion de conversion, d’une part et la rénovation de son régime, d’autre part. Au regard de cette analyse renouvelée, la conversion est vouée à un avenir prospère en tant que technique tendant au sauvetage des actes juridiques. / The thesis proposes to redefine the notion of conversion. The analysis of positive law shows that the classical definition of conversion, such as (like) the operation which consists in drawing from a null act a valid new act, may be extended from a double point of view. All that had been done was the conversion of legal acts; it has been discovered that it can be extended to instrumental acts. In the same sense, there had been contemplated only one cause of conversion, the nullity of an act; it is now accepted that it could operate as a result of a case arising a posteriori, like the lapse, the prescription, the foreclosure and the resolution. Conversion may, therefore, be defined as the technique which gives effect, by the will of the law or the judge, to a legal act which has not been formed because of an original defect or which Was able to survive because of a posteriori cause when the elements which remain correspond to the definition of a new legal figure satisfying the economic objective pursued by the parties.The thesis also proposes to modernize or renovate the regime of conversion. The modernized conversion requires the active intervention of the judge to verify that the conditions of the conversion are met, but also and especially to decide on its expediency. Conversion thus places the judge at the rank of true trainer or "maker" of the contract. The doctrinal analyzes which present conversion as based on an alleged virtual will of the parts are artificial. There is, however, no need to demonize the office of the judge by claiming that conversion is an exorbitant and authoritarian process. The anxiety which may arise from the increase of the role of the judge in conversion is appeased as soon as the judge is obliged to draw the elements of the new act into the original act. They have yet to be tempered by the constant search for a new act which responds to the original purpose of the parties.The ambition of this thesis was therefore twofold: the redefinition of the notion of conversion on the one hand and the regeneration of its regime on the other. In view of this renewed analysis, conversion is destined for a prosperous future as a technique for the rescue of legal acts.

The goal of this study was to determine the influence of sense of coherence on the experiences of participants in a developmental corporate adventure training programme. The corporate adventure training programme was described from an experiential learning paradigm, while sense of coherence was described from a salutogenic paradigm. The study was undertaken with 37 members of the South African Police Service (SAPS) from different seniority and position in the SAPS. In order to determine the participants' sense of coherence and their experiences in the corporate adventure training programme, one quantitative measuring instrument and one qualitative measuring instrument were used. The quantitative instrument used to determine the participants' sense of coherence, was the orientation to life questionnaire (OLQ). Five participants with the highest scores and five participants with the lowest scores on the orientation to life questionnaire were identified. These 10 participants were subjected to an interview, determining their experiences during the corporate adventure training programme. The results of this study have shown that people with a higher score on the orientation to life questionnaire approached and experienced the programme differently to those with a lower score on the orientation to life questionnaire. Various hypotheses were formulated from the results of the study. These hypotheses were based on the participants' feedback, and included the fact that all participants experienced the corporate adventure training programme as an opportunity to relax away from work, therefore enhancing their psychological well-being. Relationships between the participants' experiences in the corporate adventure training programme and their scores achieved on the orientation to life questionnaire, was found. The environment influenced the experiences of the participants to a large extend, a finding that differed from findings suggested by previous research. / Indust & Org Psychology / MCOM (IND AND ORG PSY)

This research worked toward a general aim of analysing the role of salutogenic functioning as moderator variable in coping and noncoping. A sample of forty-one community service doctors (N = 41) employed in KwaZulu-Natal hospitals was obtained. According to the literature, salutogenic properties are expected to act as generalised resistance resources. Based on this assertion, it was assumed that: degree of salutogenic functioning = degree of coping = degree of stress and burnout. The results demonstrated high levels of stress and depersonalisation burnout. Salutogenic functioning tended to be low, especially for sense of coherence. The results indicated, no significant relationship between stress/burnout and salutogenic functioning. Salutogenic functioning was unable to differentiate between copers and noncopers. These results contradicted the literature assertion that high scores on salutogenic functioning correlate with low scores on stress/burnout. It was concluded that variables other than personality moderated for the high levels of stress and burnout in the sample. / Industrial and Organisational Psychology / M.A. (Industrial Psychology)