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Le trouble du spectre de l’autisme se caractérise par la présence de difficultés au plan de la communication sociale et par la présence de comportements répétitifs et d’intérêts restreints (American Psychiatric Association, 2013). Les enfants ayant un TSA présentent plusieurs difficultés concomitantes qui les rendent plus susceptibles de vivre des niveaux de stress élevés, comme des déficits dans la sphère de la communication, de la socialisation et des fonctions exécutives, ainsi que la présence de particularités sensorielles (Groden et al., 1994, 2005). Malgré que ces enfants soient plus à risque de vivre du stress, plusieurs enjeux méthodologiques rendent difficile sa mesure et plus particulièrement chez ceux qui sont non verbaux. Pour ces raisons, le recours aux mesures physiologiques pour évaluer le stress auprès de cette clientèle est d’une grande pertinence. Par contre, les sensibilités sensorielles de ces enfants pourraient les rendre plus susceptibles de ne pas tolérer ces mesures. Le premier article de cette thèse vise donc à évaluer l’efficacité de l’intervention comportementale renforcement différentiel d’autres comportements (differential reinforcement of other behavior; DRO) pour augmenter la tolérance au port d’une ceinture cardiaque chez deux enfants non verbaux ayant un TSA. Les résultats obtenus démontrent que cette intervention a été efficace pour amener ces enfants à augmenter leur tolérance au port du dispositif cardiaque. Un autre aspect qui a reçu beaucoup d’attention dans les dernières années est l’implication du stress dans l’explication des comportements répétitifs et stéréotypés chez les personnes ayant un TSA. Les résultats des études antérieures sont contradictoires (de Vaan et al., 2018; Gabriels et al., 2013; Hutt et al., 1975; Lydon et al., 2015; Yang et al., 2015) et ont principalement utilisé des mesures indirectes des comportements répétitifs. Pour cette raison, le deuxième article de cet ouvrage vise à évaluer le lien entre le cortisol salivaire, le rythme cardiaque et des mesures d’observations directes de la stéréotypie chez quatre enfants minimalement verbaux ayant un TSA. Les résultats montrent que le cortisol et le rythme cardiaque sont significativement liés à la stéréotypie globale et motrice, sans que ces liens soient observés avec la stéréotypie vocale. Finalement, mesurer directement les comportements stéréotypés demande beaucoup de ressources, ce qui pourrait expliquer la prépondérance des mesures indirectes dans les études. Comme pour l’évaluation du stress, il importe de réfléchir aux méthodes alternatives abordables et accessibles qui pourraient améliorer la mesure de ces comportements. Le troisième article de cette thèse a évalué l’efficacité d’un algorithme d’intelligence artificielle (IA) dans la reconnaissance de la stéréotypie vocale chez des enfants ayant un TSA. Les résultats démontrent que la performance de l’algorithme est supérieure à la reconnaissance due au hasard. Bien que des recherches futures soient nécessaires pour augmenter l’efficacité de cette méthode, l’IA représente une technologie novatrice ayant le potentiel d’améliorer significativement les méthodes actuellement utilisées pour mesurer la stéréotypie. En conclusion, le présent ouvrage explore différentes avenues novatrices pour mieux comprendre et de monitorer la stéréotypie chez les enfants ayant un TSA. / Autism spectrum disorder (ASD) is characterized by the presence of difficulties in social communication and the presence of repetitive behaviors and restricted interests (American Psychiatric Association, 2013). Children with ASD have several concurrent difficulties, such as deficits in communication, socialization, and executive function, as well as the presence of sensory peculiarities that make them more likely to experience high levels of stress (Groden et al., 2005). Although these children are at increased risk for stress, a number of methodological issues make it difficult to measure, particularly in non-verbal children. For these reasons, the use of physiological measures to assess stress among this group is highly relevant. On the other hand, the sensory sensitivities of these children could potentially make them more likely to be intolerant to these measures. Therefore, the first study in this thesis aims to evaluate the effectiveness of differential reinforcement of other behavior (DRO) to increase compliance with wearing a heart rate monitor in two non-verbal children with ASD. The results obtained portray that this intervention was effective in getting these children to increase their compliance to wearing a cardiac device. Another aspect that has received much attention in recent years is the involvement of stress in explaining repetitive behaviors in individuals with ASD. However, the results of previous studies have been producing contradictory results (de Vaan et al., 2018; Gabriels et al., 2013; Hutt et al., 1975; Lydon et al., 2015; Yang et al., 2015), and have mainly been using indirect measures of stereotypy. For this reason, the second study in this thesis aims to evaluate the relationship between salivary cortisol, heart rate, and direct observational measures of stereotypy in four minimally verbal children with ASD. The results show that cortisol and heart rate are significantly related to global and motor stereotypy, but not to vocal stereotypy. Finally, measuring stereotypy requires a lot of resources, which could explain the preponderance of indirect measuring in studies on stress. As with the measurement of stress, it is important to consider affordable and alternative methods that could improve the measurement of these behaviors, and therefore the third study evaluated the effectiveness of an artificial intelligence (AI) algorithm in the recognition of vocal stereotypy in children with ASD. The results show that the performance of the algorithm is superior to recognition due to chance. Although future research is needed to increase the effectiveness of this method, AI represents an innovative technology with the potential to significantly improve the methods currently used to measure vocal stereotypy. In conclusion, this thesis explores different innovative methods to better understand and monitor stereotypy in children with ASD.

Thesis (MScEng (Electrical and Electronic Engineering))--University of Stellenbosch, 2007. / Clear procedures for designing dielectric resonator oscillators (DROs) are presented in this thesis, including built examples to validate these design procedures. Both series and parallel feedback DROs are discussed and the procedures for building them are presented. Two examples at different frequencies for each type of DRO are constructed and tested with the results shown. The first is at a frequency of approximately 6.22 GHz and the second for the higher frequency of 11.2 GHz. The DROs for the desired frequencies are designed using the Microwave Office (MWO) software by AWR with the design based on the small-signal model (scattering parameters). Oscillators are produced using the negative resistance method. The circuit achieves low noise by using a dielectric resonator with a high Q factor. Both the series and parallel feedback DRO circuits can be mechanically tuned around the resonant frequency to maximize performance.

Orientador: Antonio Carlos Bannwart / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Engenharia Mecânica / Made available in DSpace on 2018-07-31T15:13:41Z (GMT). No. of bitstreams: 1 ObregonVara_RosaMaribel_M.pdf: 3876695 bytes, checksum: eab8e9bdc7ff92684aba33d3163bff1a (MD5) Previous issue date: 2001 / Resumo: Considerados de grande importância na indústria petroleira, os óleos pesados constituem uma grande reserva a ser explotada e produzida. Devido a dificuldades associadas às propriedades do óleo como densidade e viscosidade, tem-se procurado métodos para produzí-lo e transportá-lo de forma econômica. Uma dessas técnicas é o corejIow, que é basicamente a injeção lateral de pequenas quantidades de água, com o fim de lubrificar o óleo, formando uma configuração concêntrica anular, onde o óleo ocupa o centro e a água a parte externa. Neste trabalho fizeram-se testes experimentaispara obter diversas informaçõessobre os padrões de fluxo em duto horizontal de um escoamento óleo pesado - água, com ênfase no padrão corejIow. Estabeleceuse uma análise de estabilidade unidimensional geral para o padrão anular liquido - líquido horizontal, através da qual chegou-se a um critério geral de estabilidade, o qual inclui o critério de Kelvin-Helmhotz, conseguindo representar bem os resultados experimentais. Os dados coletados no laboratório também permitiram desenvolver um modelo para cálculo das perdas de pressão e da fração volumétrica com correlações que consideram os fenômenos fisicos relevantes: turbulência do anel, escorregamento entre as fases, molhabilidade e rugosidade da parede e as ondulações no núcleo de óleo. O uso do corejIow consegueu reduzir a perda de pressão em até 225 vezes em comparação com o óleo sozinho / Abstract: Heavy oi! has a growingimportancein the oi! industry,given the amountof its largeand unexploited reserves. Because of the natural difficulties reIated to its physical properties - higb viscosity and density - researchhas been focusedon how to produce and transportheavyoi] economically. Oneofthemostpromisingtecbniquesinvestigated, nownascore-annularflow 01 coreflow, is based on the lateral injection of few amounts of water, so as to lubricate the oil and form an annular liquid-liquid flow pattern, with the oi! in the center, surrounded by a watel annulus. In this work, experiments were performed in a horizontal pipe, in order to obtain detailed information on different heavy oil-water flow patterns, with special interest on the core flow pattern. A one- dimensional approach to the stability ofhorizontalliquid-liquid annular flow was developed and a general stability criterion was derived, which incIudes the Kelvin-HelInholtz criterion as a special case, and gives good agreement with the laboratory measurements. The data coIlected also allowed to develop pressure drop and holdup models taking into account alI relevant physical phenomena: annulus turbulence, slip between the phases, wall wettability and roughness and interface waviness. In the present experiments, pressure drop was reduced up to 225 fold in core flow compared with the flow of an equal amount of the oi! / Mestrado / Reservatórios e Gestão / Mestre em Ciências e Engenharia de Petróleo

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Le produit naturel salinomycine (SAL) est largement utilisé comme médicament anticoccidien et maintenant de plus en plus reconnu comme un agent destiné à réduire la proportion de population CD44⁺ / CD24⁻ cellules souches du cancer du sein. Ce facteur est important et intervient lors des rechutes des tumeurs du sein. Pour la première fois, nous avons décrit que l'action n’était pas ionophorique mais que le proton dit "éponge" de la salinomycine ciblait particulièrement la population des cellules souches du cancer. De plus, un analogue alcyne-amine synthétisé de la salinomycine a une action similaire à cette dernière sur la population CD44⁺ / CD24⁻ mais à une concentration inférieure : 30 nM pour 500 nM pour la salinomycine. En utilisant la méthode de clic-imagerie, nous avons observé le composé incolore dans les lysosomes et les auto-lysosomes. En augmentant le pH des vésicules acides, la salinomycine et ses analogues inhibent les activités des cathepsines B, L et D empêchant ainsi l'autophagie. Cette autophagie joue un rôle important dans la survie des cellules souches du cancer conduisant à une augmentation du facteur ROS et à une mort cellulaire par apoptose. Notre étude donne un aperçu du mécanisme par lequel la salinomycine élimine les cellules souches cancéreuses et propose des stratégies pour le traitement de cancers résistants. / A natural product Salinomycin (SAL) is widely used as an anticoccidial drug now being increasingly recognized as an agent for reducing the proportion of CD44⁺/CD24⁻ breast cancer stem cell which is perceived as important factor for breast tumor relapse. We first time report that not ionophoric action but the proton “sponge” of SAL is responsible for distinguishingly targeting cancer stem cell population. In addition, one SAL-analog alkyne-amine performed the similar action with SAL on CD44⁺/CD24⁻ population but at much lower concentration than SAL, at 30 nM compare to 500 nM of SAL. Using click-imaging method we visually observed the colorless compound saturated in lysosomes and autolysosomes. By raising pH of acidic vesicles, SAL and its analogs inhibit cathepsin B, L, D activity preventing the autophagy which plays an important role in cancer stem cell maintain and survival thus lead to cell death via increasing ROS and apoptosis. Our study provides the insight mechanism how SAL actually eradicates cancer stem cells and suggests sharpened strategies for treating resistant cancers.

K-Band (18 to 26 GHz) dielectric resonator oscillators are typically used as a local oscillator in most K-Band digital transmitter/receiver topologies. Traditionally, the oscillator itself is made up of an active device, a dielectric resonator termination network, and a passive load matching network. The termination network embodies a cylindrical high permittivity dielectric resonator that is coupled on the same plane as a current carrying transmission line. This configuration provides an adequate resonance needed for oscillation but has some limitations. In order to provide a high Q resonance the entire oscillator is placed in a metal box to prevent radiation losses. This increases the overall size of the device and makes it difficult to integrate in smaller transceiver topologies. Secondly, a tuning screw is required to help excite the dominant mode of the resonator to achieve the high Q response. This can cause problems in precision due to the mechanical jitter of the screw inherent in mobile devices. By embedding this resonator inside the substrate it is possible to realize a very high Q resonance at a desired frequency and remove the need for a metal cavity and tuning screw. An additional advantage can be seen in terms of overall size reduction of the oscillator circuit. To demonstrate the feasibility of utilizing a dielectric resonator embedded within a substrate, a K-Band oscillator proof of concept has been designed, fabricated, and tested. The oscillator is comprised of a low noise active transistor device, an embedded k-band dielectric resonator and a passive transmission line load network. All elements within the oscillator are optimized to produce a steady oscillation near 20 GHz. Preliminary investigations of a microstrip resonator S-band (2-3 GHz) oscillator are first discussed. Secondly, various challenges in design and fabrication are discussed. Thereafter, simulated and measured results of the embedded DRO structure are presented. Emphasis is placed on output oscillation power and low phase noise. With further development, the entire oscillator can be embedded within the substrate leaving only the active device on the surface. This allows for a considerable reduction in material cost and simple integration with miniaturized digital transmitter/receiver devices.

<p dir="ltr">In the pursuit of establishing a sustainable space economy within the cislunar region, it is vital to formulate transfer design strategies that uncover economically viable highways between different regions of the space domain. The inherent complexity of spacecraft dynamics in the cislunar space poses challenges in determining feasible transfer options. However, the motion characterized by known dynamical structures modeled through the circular restricted three-body problem (CR3BP) aids in the identification of pathways with reasonable maneuver costs and flight times. A framework is proposed that incorporates a quasi-periodic orbit (QPOs) as an option to design transfer scenarios. This investigation focuses on the construction of transfers between periodic orbits. The framework is exemplified by the construction of pathways between an L2 9:2 synodic resonant Near-Rectilinear Halo Orbit (NRHO) and a planar Moon-centered Distant Retrograde Orbit (DRO). The innate difference in the geometries of the departure and arrival orbits of the sample case, along with the lack of natural flows towards and away from them, imply that links between these orbits may necessitate costly maneuvers. A strategy is formulated that leverages the stable and unstable manifolds associated with intermediate periodic orbits and quasi-periodic orbits to construct end-toend trajectories. As part of this strategy, a systematic methodology is outlined to streamline the determination of transfer options provided by the 5-dimensional manifolds associated with a QPO family. This approach reveals multiple local basins of solutions, both interior and exterior-types, characterized by selected intermediate orbits. The construction of transfers informed by the manifolds associated with QPOs is more intricate than those based on periodic orbits. However, QPO-derived solutions allow for the recognition of alternative local basins of solutions and often offer more cost-effective transfer options when compared to trajectories designed using periodic orbits that underlie the QPOs.</p>

Building on recent scholarship in the history of art which has started to reappraise the meaning of grotesque and scatological motifs, this thesis examines how digestion was conceived of as a model of creation, and how this was translated visually. Renaissance creativity was increasingly modelled on a series of natural processes like digestion, following a trend in favour of Aristotelian psychology. However, it has been largely overlooked in comparison to the bleeding, the pneumatic, and especially the procreative natural models, which have been extensively studied. The central argument of this thesis is that digestion constituted an alternative-albeit less 'decorous'-model of creation, denoting the intervention of a more 'earthbound' ingenium. I argue that this model was used by certain classes of artists as an acknowledgement of a strong engagement with materials and of the labour of a round-the-clock imagination. Goldsmithing and printmaking are artistic professions whereby the artistic process was often considered as an act of 'soiling' oneself, both in the sense of the body and the phantasia. This thesis focuses on a period spanning c. 1530 to 1675, from Rabelais' works to the facetious printer Jacques Lagniet. It mines a corpus of little-studied textual and visual sources from the north of the Alps, examining a continuity between France and the German lands: geographical areas which both had an especially pronounced 'culture of excretion'. From a broader perspective, this research responds to a widespread scholarly call for more attention to the organic soul and the lower body, nuancing the alleged hegemony of the brain and the higher senses throughout history. It seeks to modify the perception of early modern artists and viewers as cerebral intellectuals, presenting them as individuals who also 'thought with their guts'.

<div>As destinations of missions in both human and robotic spaceflight become more exotic, a foundational understanding the dynamical structures in the gravitational environments enable more informed mission trajectory designs. One particular type of structure, quasi-periodic orbits, are examined in this investigation. Specifically, efficient computation of quasi-periodic orbits and leveraging quasi-periodic orbits as trajectory design alternatives in the Earth-Moon and Sun-Earth systems. First, periodic orbits and their associated center manifold are discussed to provide the background for the existence of quasi-periodic motion on n-dimensional invariant tori, where n corresponds to the number of fundamental frequencies that define the motion. Single and multiple shooting differential corrections strategies are summarized to compute families 2-dimensional tori in the Circular Restricted Three-Body Problem (CR3BP) using a stroboscopic mapping technique, originally developed by Howell and Olikara. Three types of quasi-periodic orbit families are presented: constant energy, constant frequency ratio, and constant mapping time families. Stability of quasi-periodic orbits is summarized and characterized with a single stability index quantity. For unstable quasi-periodic orbits, hyperbolic manifolds are computed from the differential of a discretized invariant curve. The use of quasi-periodic orbits is also demonstrated for destination orbits and transfer trajectories. Quasi-DROs are examined in the CR3BP and the Sun-Earth-Moon ephemeris model to achieve constant line of sight with Earth and avoid lunar eclipsing by exploiting orbital resonance. Arcs from quasi-periodic orbits are leveraged to provide an initial guess for transfer trajectory design between a planar Lyapunov orbit and an unstable halo orbit in the Earth-Moon system. Additionally, quasi-periodic trajectory arcs are exploited for transfer trajectory initial guesses between nearly stable periodic orbits in the Earth-Moon system. Lastly, stable hyperbolic manifolds from a Sun-Earth L₁ quasi-vertical orbit are employed to design maneuver-free transfer from the LEO vicinity to a quasi-vertical orbit.</div>