A evidência científica da cariologia atual vem apontando para a promoção de saúde bucal, técnicas preventivas, diagnóstico precoce da doença cárie e suas lesões nos elementos dentais, remineralização de lesões de cárie incipientes e a intervenção restauradora célere como procedimentos minimamente invasivos. Durante o ato de remoção de lesão de cárie, é comum remover-se inadvertidamente também tecido dental hígido durante a fase final, por ser um tanto quanto difícil precisar clinicamente os limites entre tecido dental comprometido e tecido dental viável. Usando-se a tecnologia com lasers de Érbio, uma dica clínica subjetiva é a mudança da percepção do som emitido pela ablação do tecido dental ao passar-se de substrato cariado para hígido (de grave para agudo), como uma forma adicional de saber que a ablação naquele ponto deve ser interrompida. Este estudo visa classificar estas diferenças sonoras em dentina e torná-las um parâmetro objetivo para odontologia de mínima intervenção ao usar-se lasers de Érbio. Para tanto, foram realizadas três fases do estudo: primeiramente, utilizaram-se vinte dentes posteriores humanos, sendo dez cariados e dez hígidos. A dentina foi irradiada com laser de Er:YAG sob os mesmos parâmetros, distância e refrigeração e um microfone monodirecional foi posicionado a 10cm da área operatória para captação e gravação dos sons produzidos pela ablação ao se operar tanto em dentina hígida quanto cariada. Dez pulsos por arquivo foram então analisados em um software (200 análises). Foram encontradas diferenças entre os padrões sonoros produzidos dos grupos cariados e hígidos e encontrado um ponto de corte para estas freqüências sonoras, que seria testado a seguir. Em outra segunda etapa, foi desenvolvido, testado e aplicado um software limitador de freqüência sonora, para que, em tempo real, avisasse o operador se o tecido dentinário que estava sendo ablacionado pelo laser de Érbio (Er:YAG e Er,Cr:YSGG) era cariado ou viável, e este evitasse o sobrepreparo, ou seja, desgastar o tecido sadio inadvertidamente, de acordo com os preceitos de mínima intervenção. Finalmente, em uma terceira etapa, o método foi validado através dos critérios visual-tátil e de fluorescência a laser; ilustrações representativas dos espécimes testados foram obtidas através de microscopia de luz e de microscopia eletrônica de varredura. Conclui-se que o som da ablação dentinária é um parâmetro objetivo que pode ser utilizado como um recurso adicional de orientação no processo de remoção de dentina cariada com lasers de Érbio e que a ferramenta desenvolvida para tanto foi efetiva, devendo ser aprimorada. O método foi validado exitosamente pelos critérios propostos. / Studies in cariology have been struggling for the development of health promotion, caries prevention techniques, precocious diagnoses of lesions, re-mineralization of incipient carious lesions and early restorative intervention with minimally invasive procedures. When removing caries lesion, healthy dental structure is often removed inadvertently during its final phase, for being quite difficult to clinically precise the limits between viable and decayed dental tissues. With laser technologies, a subjective clinical hint, often used to indicate when tissue ablation should be stopped is that different sounds are perceptive whether in carious (bass) or in healthy (treble) dental structure; when sound produced by ablation turned treble it would mean that healthy tissue was reached. This study aims to classify those audio differences and to turn them into objective parameters for a conservative operative dentistry with minimally invasive tissue removal when using Erbium lasers. For so, three phases of this study were needed: at first, twenty freshly extracted posterior human teeth were used (10 decayed and 10 sound teeth). Dentine was irradiated with Er:YAG laser under the same parameters, distance and refrigeration and a mono directional microphone was set 10cm far from the operative area in order to capture and record the ablation produced sounds when working either on carious or healthy dentine. Ten pulses per file were then analyzed in a computer software (200 analyses).It was permitted to draw differences between decayed and healthy produced sounds and also to establish a cut-off value for these sound frequencies, that would be tested later on. On a second phase, a piece of software which was able to border the sound frequency was then developed and tested. This tool was meant to warn the operator, in real-time basis, if sound dentine was reached, while it was ablated by Erbium lasers (either Er:YAG or Er,Cr:YSGG) and so one could avoid over-treatment, which means not to remove sound tissue inadvertently, according to minimal intervention dentistry concepts. Finally, on a third part of the study, the proposed guiding method for dentine caries removal was validated through visuo-tactile and laser fluorescence criteria. Representative illustrations of the tested specimens were obtained by light microscopy and scanning electron microscopy. As a conclusion, audio analysis came out to be a technical reliable objective parameter to determine whether laser ablated dentine substrates are decayed or sound; therefore it can be proposed as an additional conservative parameter to guide the clinician during dentine caries removal process, and that the tool developed for so was effective and should be sharpened. This method was successfully validated by the proposed criteria.

Sammanfattning Syfte och frågeställningar Syftet med studien var att jämföra ett damallsvenskt lag med det svenska damlandslaget i total belastning, total distans, högintensiva löpningar (HL), mycket högintensiva löpningar (MHL) samt sprints (S). Frågeställningarna var följande: Skiljer sig total belastning och total distans mellan de två lagen? Finns det skillnader i total belastning och total distans mellan olika positioner? Finns det skillnader i HL, MHL samt S i antal genomförda och sträcka mellan lagen och mellan olika positioner? Metod Studien genomfördes på åtta kvinnliga fotbollsspelare (ålder 27±1,8, längd 168±4,7, vikt 65±4,7). Dessa representerar ett damallsvenskt lag som spelade i övre delen av tabellen under år 2017. För att genomföra mätningen användes ett GPS-system (MinimaxX S4). Mätningen genomfördes under match vilken spelades på naturgräs. Vidare har värden från landslagets 12 spelare inhämtats från SvFF (ålder 28±4,5, längd 174±5, vikt 64±4,2). Resultat Resultatet visar att klubblagets totala belastning var 186 större än landslagets. Ingen signifikant skillnad fanns mellan de två lagen. Klubblagets mittfältare belastades 19 % mer än landslagets. Vidare belastades klubblagets anfallare 33 % mer än landslagets medan backarna i klubblaget belastades med 7 % mer än landslagets. Klubblaget sprang 15 % längre än landslaget. Ingen signifikans fanns mellan lagen. Klubblagets totala distans visar att spelarna sprang längre än landslaget på alla positioner. Resultatet visade vidare att det inte fanns någon signifikans mellan lagen för HL, MHL och S. Klubblaget sprang 1 % fler antal meter HL och 13 % fler antal meter MHL än landslaget. Landslaget sprang även 3 % fler antal meter S än klubblaget. Den procentuella skillnaden mellan lagen var 19 % fler antal genomförda HL och 9 % fler antal genomförda MHL samt 17 % fler antal S än klubblaget. Landslaget genomförde fler antal HL, MHL och S på samtliga positioner. Slutsats Studien visar att det inte finns någon signifikant skillnad mellan grupperna. Dock genomförde landslaget fler S i antal och sträcka vilket överensstämmer med tidigare studier som visar att lag som spelar på högre nivå genomför fler högintensiva aktioner under en match. Studiens omfång bör utökas för att vidare undersöka dessa variabler. / Abstract Aim The aim of this study was to compare a Swedish top league soccer team to the Swedish national team during a competitive game. Comparisons included measurements in player load, total distance covered, high-speed running (HL), very high-speed running (MHL) and sprint (S). The research questions were: Is there a difference in player load and total distance covered between the teams? Is there a difference in player load and total distance covered between different playing positions? Is there a difference in HL, MHL and S in performed and meters covered between different positions and between the two teams?     Method The number of participants were eight female soccer players (age 27±1,8, length 168±4,7, weight 65±4,7). They played in the top of the league during the season of 2017. A GPS system (MinimaxX S4) was used to collect data. The game was played on nature grass in the last round of the season. The National team values were supplied by SVFF where 12 players participated (age 28±4,5, length 174±5, weight 64±4,2). Results The Swedish league team had 186 higher player load than the National team where no significant difference was found. Furthermore, the Swedish league team’s midfielders were loaded 19 % more than the national team’s. The Swedish league attackers were loaded 33 % more than the national team’s. The difference in player load between the defenders was 7 % higher for the Swedish league team’s. The Swedish league team covered 15 % more meters in total distance where no significant difference was seen. All players in the Swedish league team covered the longest distance. There were no significant difference between number of performed and meters covered in HL, MHL and S. The Swedish league team covered 1 % more meters HL and 13 % more meters MHL than the National team. The National team covered 3 % more meter S than the Swedish league team. The National team performed 19 % more HL and 9 % more MHL than the Swedish league team. In total, the National team performed more HL, MHL and S than the Swedish league team.      Conclusion No significant difference was found between the two teams. Although, the National team covered higher number of S performed and meters which is in accordance to previous surveys which shows more high-speed actions is performed in higher competition levels during a game. The survey should be expanded to further examine the demands for women’s soccer. / <p>Ämneslärarprogrammet, Specialidrott</p>

Submitted by Adriana Martinez (amartinez@unoeste.br) on 2018-02-07T17:06:20Z No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Francilene.pdf: 356698 bytes, checksum: 1dbb03ec82dfb5f6f0997237b2784d9a (MD5) / Made available in DSpace on 2018-02-07T17:06:20Z (GMT). No. of bitstreams: 2 license_rdf: 0 bytes, checksum: d41d8cd98f00b204e9800998ecf8427e (MD5) Francilene.pdf: 356698 bytes, checksum: 1dbb03ec82dfb5f6f0997237b2784d9a (MD5) Previous issue date: 2017-10-30 / Introduction: Systemic Arterial Hypertension (SAH) is a serious public health problem, especially for the elderly, and can lead to concentric hypertrophy an important risk factor for heart failure, which is considered a predictor of increased cardiovascular morbimortality. Studies have shown that High Intensity Interval Training (HIIT) may also be indicated for hypertensive patients. However, to the authors’ knowledge, no studies have evaluated HIIT in cardiac remodeling of animals with systemic arterial hypertension. Objective: to evaluate in spontaneously hypertensive rats (SHR) submitted to HIIT, pressure control, exercise tolerance and cardiac remodeling. Methods: 20 SHR rats were divided into two groups: sedentary (SHR-SED, n= 9) and HIIT training (SHR-HIIT, n= 11); and Wistar Kyoto rats composed the control group (WKY, n= 6), 12 months of age. The animals were familiarized with HIIT for a week with 10 minutes on the treadmill adapted for rodents. An incremental stress test was performed to exhaustion to adjust exercise intensity. The HIIT was performed five times a week for eight weeks. Before and after HIIT, blood pressure (BP) was measured by plethysmography and a maximal exercise capacity test was performed. Cardiac remodeling was assessed through echocardiography and after euthanasia, the isolated papillary muscle was evaluated. For comparison between groups, we used ANOVA followed by the Tukey test or Kruskal-Wallis and Dunn tests (p <0.05). Results: HIIT decreased the variation (Δ%) of SBP (SHR-SED=Δ% 12.5 vs. SHR-HIIT=Δ% -4.34; p = 0.005), increased the distance traveled, being 82.7% higher in the SHR-HIIT group (SHR-SED=183.0±88.08m; vs. SHR-HIIT=1126.0±187.1m; p<0.001) and reduced the resting tension of the papillary muscle (WKY=0.77 ± 0.216; SHR-SED=1.26 ± 0.20; SHR-HIIT=0.67 ± 0.23; p=0.0001). Conclusion: In SHR rats, HIIT decreased BP variation, improved functional capacity and ameliorated pathological cardiac remodeling. / Introdução: a Hipertensão Arterial Sistêmica (HAS), um grave problema de saúde pública, pode levar à hipertrofia concêntrica – um importante fator de risco para insuficiência cardíaca, que é considerada um preditor de maior morbimortalidade cardiovascular. Estudos evidenciam que o Treinamento Intervalado de Alta Intensidade (HIIT) pode ser indicado para hipertensos. Entretanto, para conhecimento, não há estudos que avaliaram o HIIT na remodelação cardíaca de animais com hipertensão arterial sistêmica. Objetivo: avaliar em ratos espontaneamente hipertensos (SHR) submetidos ao HIIT, o controle pressórico, a tolerância aos exercícios e o remodelamento cardíaco. Métodos: foram utilizados 20 ratos SHR divididos em dois grupos: sedentários (SHR-SED, n=9) e com treinamento HIIT (SHR-HIIT, n=11); e ratos Wistar Kyoto no grupo controle (WKY, n=6), com 12 meses. Os animais foram familiarizados antes do início do teste durante uma semana com 10 minutos, na velocidade de 6 metros por minutos na esteira adaptada para roedores. Realizou-se um teste de esforço incremental, iniciando-se com 10 minutos de aquecimento na velocidade de 6 metros por minutos, sem inclinação até que os ratos chegassem a exaustão, para graduar a intensidade do exercício. O HIIT foi executado cinco vezes por semana, durante oito semanas. Antes e após o HIIT, a pressão arterial (PA) foi aferida por pletismosgrafia e foi realizado um teste de capacidade máxima ao exercício. O remodelamento cardíaco foi avaliado pelo ecocardiograma e, após eutanásia, avaliou-se o músculo papilar isolado. Para comparação entre os grupos foi utilizado ANOVA seguido de Tukey ou Kruskal-Wallis e Dunn’s (p<0.05). Resultados: o HIIT diminuiu a PAS (SHR-SED=Δ%12.05 vs. SHR-HIIT=Δ%-4.34; p=0.005), aumentou a distância percorrida, sendo 82,7% maior no grupo SHR-HIIT (SHR-SED=183.0±88.08m vs. SHR-HIIT=1126.0±187.1m; p<0.0001) e reduziu a tensão de repouso do músculo papilar (WKY=0.77 ± 0.216; SHR-SED=1.26 ± 0.20; SHR-HITT=0.67 ± 0.23; p=0.0001). Conclusão: o HIIT em ratos SHR diminuiu a variação da PA, melhorou a capacidade funcional e amenizou o remodelamento cardíaco patológico.

Objectif : L’objectif de cette recherche était d’identifier les processus et facteurs impliqués dans le phénomène de l’abandon du traitement chez les délinquants sexuels et d’explorer les différences et similitudes entre les expériences d’abandon et les expériences de complétion d’un traitement. Méthode : Sept entrevues semi-dirigées ont été menées avec des hommes purgeant une peine fédérale en lien avec des délits de nature sexuelle. Ceux-ci étaient incarcérés dans un pénitencier ou en surveillance dans la collectivité sous la juridiction du SCC dans la région du Québec. Les entrevues ont été retranscrites et analysées selon une approche de théorisation ancrée. Résultats : Les résultats ont permis d’élaborer un premier modèle de l’abandon du traitement chez les délinquants sexuels. Ce modèle comprend deux voies, qui comportent chacune deux phases, soit la phase « Avant le programme » et la phase « Pendant le programme ». La Voie #1- Abandon rapide est caractérisée par la présence d’un conflit préexistant avant le début du programme. Pendant le programme, des insatisfactions à l’égard des intervenants surgissent et sont tolérées un certain temps avant l’abandon, qui survient typiquement après quelques séances seulement. Dans la Voie #2-Abandon tardif, des facteurs de vulnérabilité préexistants se retrouvent dans la phase « Avant le programme ». Pendant le programme, des conflits entre les participants et leurs intervenants ou leurs coparticipants surviennent et déclenchent des pensées d’abandon. Survient ensuite un événement précipitant qui favorise un discours interne décisif, puis l’abandon, qui prend place après plusieurs semaines de traitement. Les résultats permettent de constater que le concept de conflit se situe au coeur du phénomène de l’abandon du traitement chez les délinquants sexuels. De plus, les expériences d’abandon se démarquent par l’absence d’une alliance thérapeutique entre les participants et leurs intervenants. Plusieurs facteurs contributifs à la réussite sont également notés, notamment des perceptions favorables envers les intervenants et les autres participants, puis des dispositions personnelles favorables. / Objective: The objective of this research was to identify the process and factors that play a role in treatment drop-out for sexual offenders and to target the similarities and differences between the drop-out experiences and that of program completion. Method: Seven semi-structured interviews were conducted with men serving a federal sentence for sex-related crimes. These individuals were either incarcerated in a federal penitentiary or being supervised in the community under CSC jurisdiction in the region of Quebec. The interviews were transcribed and analysed according to a grounded theory approach. Results: The results enabled the elaboration of an initial model for treatment drop-out in sexual offenders. This model is comprised of two pathways containing two phases each: the "Before the program" phase and the "During the program" phase. Pathway #1-Rapid drop-out is characterised by the presence of a pre-existing conflict. During the program, unhappiness with the program facilitator arises and is tolerated for a brief amount of time before the individual drops out. In Pathway #2-Delayed drop-out, pre-existing vulnerability factors can be found in the "Before the program" phase. Over the course of the program, conflicts between the participants and either the program facilitator or co-participants arise and trigger the thought of dropping out. This is followed by a precipitating event that favors a decisive internal discourse followed by dropping out, typically much later in the program. The results from this research demonstrate that conflict appears to be at the heart of treatment drop-out for sexual offenders, combined with the absence of a quality therapeutic alliance between the participants and their program facilitators. Many factors contributing to treatment completion were also identified, such as a positive perception of the program facilitator and other participants, as well as favorable personal dispositions.

Disertace popisuje současné problémy v certifikaci malých letadel, které by se měly v budoucnu řešit numerickým modelováním. Tento postup má zefektivnit návrh a zlevnit certifikaci letadel. Práce je úzce spjata s projektem HIRF-SE, který se problematikou certifikace letadel numerickými metodami zabývá. Podstatná část práce je věnována popisu dvou modulů pro platformu HIRF-SE: řešič BUTFE založený na metodě konečných prvků v časové oblasti a budicí nástroj BUTFE_EXC. Práce popisuje řešení pohlcujících okrajových podmínek, modelování disperzních a anizotropních materiálů a aproximaci tenkých drátů. Speciální pozornost je věnována řešení aproximace tenkých drátů s ostrými ohyby, jejíž současná formulace způsobuje překryvy mezi jednotlivými segmenty drátu.

A la croisée des chemins entre médecine et physique des ultrasons, ce travail de thèse s’est intéressé à l’apport de solutions diagnostiques et de thérapeutiques novatrices dans le domaine de l’électrophysiologie cardiaque. Un système capable de délivrer des ultrasons focalisés dans le cœur par voie transoesophagienne sous guidage par ultrasons a été développé et testé in vivo chez 6 porcs. Les tirs HIFU ont été délivrés sur les oreillettes et les ventricules. Lors de l'autopsie, une analyse visuelle a démontré la présence de lésions thermiques dans les zones ciblées chez 3 animaux. Ces lésions ont été confirmées par analyse histologique (taille moyenne: 5,5 mm2 x 11 mm2). Aucune lésion thermique œsophagienne n'a été observée. Un animal a présenté une bradycardie due à un bloc auriculo-ventriculaire, ce qui a permis de confirmer une réelle interaction entre les tirs HIFU et le tissu nodal cardiaque. Nous avons cependant observé un manque de précision, principalement lié aux mouvements cardiaques ainsi qu’aux structures anatomiques situées entre les zones ciblées et le transducteur de thérapie. Ces difficultés ont été principalement reliées à l’anatomie du modèle porcin, loin de celle de l’être humain. La recherche d'un meilleur modèle a conduit à des tests d'imagerie concluants sur des babouins.Des expériences supplémentaires ont été conduites afin d'améliorer la cartographie des arythmies ventriculaires et le suivi de la formation de lésions pendant l'ablation.Des expériences ont été menées sur les ventricules gauches de quatre coeurs de porcs en mode travaillant. Le protocole visait à démontrer que différents modèles d'activation mécanique pouvaient être observés, que le ventricule soit en rythme sinusal, stimulé depuis l'épicarde ou l'endocarde. Des acquisitions d’imagerie de déformation électromécanique (EWI) ont été enregistrées sur les faces antérieures, latérales et postérieures du ventricule gauche. Les boucles ont été ensuite analysées à l’aveugle par deux lecteurs indépendants.Les interprétations des séquences EWI étaient correctes dans 89% des cas. Le taux de concordance globale entre les deux lecteurs était de 83%. Dans un ventricule stimulé, l'origine du front d'onde était focale et provenait de l'endocarde ou de l'épicarde stimulé. En rythme sinusal, le front d'onde était activé depuis tout l'endocarde, en direction de l'épicarde, à une vitesse de 1,7 ± 0,28 m.s-1. Les vitesses du front d'onde ont été mesurées respectivement lorsque l'endocarde ou l'épicarde étaient stimulés à une vitesse de 1,1 ± 0,35 m.s -1 et 1,3 ± 0,34 m.s-1 (p = NS). Nous avons aussi démontré sur des échantillons ex-vivo que l'imagerie trans oesophagienne par analyse des ondes de cisaillement (élastographie) pouvait cartographier l'étendue des lésions HIFU. Des tirs HIFU ont été réalisés à l'aide de la sonde trans oesophagienne sur des échantillons de blancs de poulet (n = 3), puis sur un modèle porcin ex vivo d'oreillette (gauche, n = 2) et de ventricule gauche (n = 1). L’élastographie a fourni des cartes de rigidité des tissus avant et après l'ablation. Les zones des lésions ont été obtenues par analyse et quantification des changements de couleur des tissus puis ont été comparées aux images par élastographie. Dans le blanc de poulet, la rigidité est passée en moyenne de 4.8±1.1 kPa à 20.5±10.0 kPa (ratio 5.0±3.2). Dans le ventricule gauche, la rigidité est passée en moyenne de 21.2±3.3kPa à 73.8±13.9kPa (ratio 3.7±1.2). Dans l’oreillette gauche, la rigidité est passée en moyenne de 12.2±4.3 kPa à 30.3±10.3 (ratio 3.2±2.0). En histologie, la taille des lésions variait de 0.1 à 1.5 cm2 dans la zone du plan d'imagerie. Les caractéristiques morphométriques étaient similaires entre histologie et élastographie / At the crossroads of medicine and physics, this work aimed to provide innovative diagnostic and therapeutic tools based on ultrasound, in the field of cardiac electrophysiology. A system capable of delivering HIFU into the heart by a transesophageal route using ultrasound (US) imaging guidance was developed and tested in vivo in six male pigs. HIFU exposures were performed on atria and ventricles. At the time of autopsy, visual inspection identified thermal lesions in the targeted areas in three of the animals. These lesions were confirmed by histologic analysis (mean size: 5.5 mm2 x 11mm2). No esophageal thermal injury was observed. One animal presented with bradycardia due to an atrio-ventricular block, which provides real-time confirmation of an interaction between HIFU and the electrical circuits of the heart. There was still a lack of accuracy, mainly related to cardiac motion, and to anatomical structures in between the targets and the transducer. It was mainly related to the in vivo model and its anatomy, far from the human’s. The search for a better model led to conclusive imaging tests on baboons. Additional experiments were conduced in order to improve the mapping of ventricular arrhythmias and the monitoring of lesion formation during ablation. First, experiments were conducted on left ventricles of four isolated working mode swine hearts. The protocol aimed at demonstrating that different patterns of mechanical activation could be observed whether the ventricle was in sinus rhythm, paced from the epicardium, or from the endocardium. Electromechanical wave imaging (EWI) acquisitions were recorded on the anterior, lateral, and posterior segments of the left ventricle. Loop records were blindly assigned to two readers. EWI sequences interpretations were correct in 89% of cases. The overall agreement rate between the two readers was 83%. When in a paced ventricle, the origin of the wave front was focal and originating from the endocardium or the epicardium. In sinus rhythm, wave front was global and activated within the entire endocardium towards the epicardium at a speed of 1.7±0.28 m.s-1. Wave front speeds were respectively measured when the endocardium or the epicardium were paced at a speed of 1.1 ± 0.35 m.s-1 vs 1.3±0.34 m.s-1 (p=NS). Lastly, we investigated the feasibility of a dual therapy and imaging approach with the same transoesophageal device. We demonstrated on ex-vivo samples that transoesophageal shear wave imaging (SWE) can map the extent of the HIFU lesions. HIFU ablation was performed with the transoesophageal probe on ex-vivo chicken breast samples (n=3), then atrium (left, n=2) and ventricle (left n=1, right n=1) of swine heart tissues. SWE provided stiffness maps of the tissues before and after ablation. Areas of the lesions were obtained by tissue color change with gross pathology and compared to SWE. Shear modulus of the ablated zones increased from 4.8±1.1 kPa to 20.5+/-10.0 kPa (ratio 5.0±3.2) in the chicken breast, from 12.2±4.3 kPa to 30.3±10.3 (ratio 3.2±2.0) in the atria and from 21.2±3.3kPa to 73.8±13.9kPa (ratio 3.7±1.2) in the ventricles. On gross pathology, the size of the lesions ranged from 0.1 to 1.5cm2 in the imaging plane area and morphometric characteristics were fitting with elasticity-estimated depths and widths of the lesions

Lors de la réflexion d’un laser femtoseconde ultra-intense [Iʟ > 10¹⁶ W/cm²] sur une cible solide, celle-ci est ionisée dès les premiers cycles de l’impulsion. Un plasma se détend alors vers le vide avec un profil exponentiel de longueur caractéristique Lg. Pour de faibles longueurs de gradient Lg < λʟ, le gradient plasma est considéré comme raide, il réfléchit spéculairement l’impulsion incidente : c’est un miroir plasma. De tels plasmas, réfléchissant pour la lumière, sont aujourd’hui exploités dans différentes applications scientifiques, comme l’accélération de particules par laser ou encore la génération d’harmoniques d’ordre élevé, associées dans le domaine temporel à un train d’impulsions attosecondes. Néanmoins, pour favoriser ces émissions de lumière ou de particules, le transfert d’énergie entre l’impulsion laser incidente et le plasma est essentiel. L’objectif de cette thèse est de mieux comprendre ces interactions à l’aide de la caractérisation de ces deux observables physiques qui en sont issues : les émissions d’électrons relativistes et d’harmoniques d’ordre élevé. Tout d’abord, nous reportons dans ce manuscrit la première étude expérimentale et numérique détaillée des mécanismes de couplage laser-plasma dense impliqués en régime relativiste [Iʟ > 10¹⁸ W/cm²] en fonction notamment de la longueur caractéristique de gradient Lg. Cette étude a notamment permis d’identifier deux régimes distincts en fonction des conditions d’interaction, éclaircissant ainsi la physique régissant ces systèmes. Par ailleurs, au delà de cet aspect fondamental, le contrôle de ces sources est également essentiel pour de futures expériences. Pour cela, différentes approches permettant de mettre en forme spatialement et temporellement ces impulsions de lumière ultra-brèves ont été étudiées au cours de ce doctorat, ouvrant ainsi de nouvelles perspectives pour l’utilisation de ces sources. En particulier, nous démontrons qu’il est possible d’introduire un moment angulaire orbital aux impulsions XUV attosecondes via la mise en forme spatiale du faisceau IR femtoseconde incident ou bien de plasma dense créé à la surface de la cible mais également de contrôler la dynamique des électrons de surface du plasma à l’échelle attoseconde à l’aide d’un champ incident à deux couleurs. Finalement, une méthode novatrice basée sur des mesures de ptychographie dynamique a été développée afin de caractériser spatio-temporellement ces impulsions de lumière ultra-brèves, constituant un enjeu majeur pour la communauté. / When an ultra-intense femtosecond laser beam [Iʟ > 10¹⁶ W/cm²] is focused on a solid target, the surface becomes completely ionized during the first optical cycles of the laser pulse. Due to their solid-like density and to their limited expansion into the vacuum such plasmas specularly reflect these pulses, just like ordinary mirrors do for low intensity. These plasmas are now used in many scientific applications like particle acceleration by laser light as well as high-order harmonic generation, associated to a train of attosecond pulses in the time domain. Nevertheless, to favor these emissions of light or particle, the energy transfert between the incident field and the dense plasma is crucial. The aim of this thesis is to better understand these interactions through the characterization of high-order harmonics and relativistic electron beams generated on plasma mirrors. We reported in this manuscript the first detailed experimental and numerical study of the coupling mechanisms involved between an ultra-intense laser light [Iʟ > 10¹⁸ W/cm²] and a dense plasma, and more specifically as a function of the gradient scale length Lg. These results enabled to identify two different regimes, clarifying some physical issues. Furthermore, beyond these fondamental aspects, the control of these sources is essential, particularly for futures pump-probe experiments or new spectroscopies. For that, several approaches have been studied to temporally and spatially shape these ultra-short light pulses, thus opening up new perspectives for these sources. We demonstrate in particular the generation of intense XUV vortex beam either by spatially shaping the incident IR field or the dense plasma created at the target surface as well as controlling the electron dynamics on the attosecond time scale with relativistic two-color waveforms. Finally, an innovative method based on in-situ ptychographic measurements has been developed to simultaneously characterize in time and space these ultrashort XUV light pulses, constituting one of the major challenges of the community.

No description available.

This study investigated the effects of high intensity interval training (HIIT) and β-hydroxy-β-methylbutyric free acid (HMBFA) on the onset of neuromuscular fatigue in healthy young men and women. Thirty-seven subjects (22 men and 15 women; mean ± SD age = 22.8 ± 3.4yrs) completed an incremental cycle ergometer test (GXT) to exhaustion. During the GXT, electromyography (EMG) signals from the right vastus lateralis were recorded to determine the power output at the onset of neuromuscular fatigue (PWCFT), and peak wattage was used to assign individual training loads. After baseline testing (PRE), subjects were randomly assigned to one of three groups: control (C, n = 9), training with placebo (P, n = 14), or training with supplementation (S, n = 14). Subjects assigned to P and S completed 12 HIIT sessions over 4 weeks while subjects assigned to C were asked to maintain their normal diet and activity patterns. After 4 weeks, subjects returned for post-testing (POST). The PWCFT values (W) were determined using a DMAX method. The EMG amplitude root mean square (µVrms) values were used to generate a third-order polynomial regression (3PR) representing the increase in µVrms versus time of the GXT. The onset of fatigue (TF) was defined as the x-value (time, s) of the point on the 3PR that measured the maximal perpendicular distance from the line between the first and last data points. TF was used to estimate PWCFT according to the equation: PWCFT = PO + a · (n/N), where PO is the power output of the stage in which TF occurred, a is the increment in power output between GXT stages (25W), n is the difference (s) between TF and the beginning of the stage during which TF occurred, and N is the duration of a stage (120s). A two-way repeated measures ANOVA was used to identify group × time interaction for PWCFT. If a significant interaction occurred, one-way factorial ANOVAs were used. Fisher's least significant difference post hoc comparisons were performed between groups. If a significant main effect occurred, dependent samples t-tests with Bonferroni corrections (p = [0.05/3] = 0.017) were performed across time for each group. The two-way ANOVA resulted in a significant interaction (F = 6.69, p = 0.004). Follow-up analysis with one-way ANOVA resulted in no difference among groups at PRE (F = 0.87, p = 0.43), however a significant difference was shown for POST values (F = 5.46, p = 0.009). Post-hoc analysis among POST values showed significant differences between S and both P (p = 0.034) and C (p = 0.003). No differences (p = 0.226) were noted between P and C. Paired samples t-tests detected significant changes following HIIT for S (p < 0.001) and P (p = 0.016), but no change in C (p = 0.473). Results of this study indicate that HIIT was effective in delaying the onset of fatigue, but supplementation with HMBFA in conjunction with HIIT was more effective than HIIT alone. An increase in PWCFT represents an increase in the maximal power output an individual can sustain without eliciting fatigue. Therefore, HIIT can be used to improve performance in both endurance activities as well as intermittent sports. In addition, HMBFA supplementation is a simple method that can be used to maximize the benefits of HIIT. Acknowledgments: Metabolic Technologies, Inc. provided the supplement and funding for this study.

Objectifs Les études évaluant l’efficacité de l’entraînement physique chez les lombalgiques chroniques observent généralement des tailles d’effet faibles à modérer. Une possibilité est que les essais ont été trop courts pour observer le plein potentiel de l’exercice physique. Nous avons cherché à caractériser la cinétique de la douleur pendant un régime d’exercice multimodal afin d’explorer si les participants pourraient bénéficier de régimes d’exercice plus long. Méthodes Cinquante-sept participants souffrant de lombalgie chronique ont suivi un régime d’exercice multimodal (exercices aérobies et en résistance) ou une période d’attente. Les capacités physiques et fonctionnelles des participants ont été évaluées avant l’intervention et la semaine suivant la complétion du protocole. L’intensité de la douleur dans le bas du dos a été enregistrée au début de chaque séance d’entraînement afin de suivre l’évolution de la douleur pendant le programme d’entraînement. Une modélisation linéaire à effets mixtes a été réalisée pour décrire la cinétique de la douleur. Des analyses de modération ont été effectuées pour vérifier si le sexe, l’intensité de la douleur au début du programme et l’amélioration des capacités physiques pouvaient prédire une plus grande réduction de la douleur. Résultats Les participants du groupe d’entraînement, mais pas ceux du groupe contrôle, se sont améliorés aux tests de capacités physiques. Cependant, les participants du groupe d’entraînement ne semblent pas avoir amélioré leurs capacités fonctionnelles. La douleur a diminué tout au long du programme d’entraînement (terme linéaire : 𝛽 = −14.89, 𝑝 < .001). Cependant, la réduction de la douleur ralentissait à mesure que les participants progressaient dans le programme d’entraînement (𝛽 = −5.48, 𝑝 = .001). La réduction de la douleur était modérée par l’amélioration des capacités physiques et l’intensité de la douleur au début du programme, mais pas par le sexe. Conclusion Il semble que l’efficacité de l’entraînement physique atteigne un effet plancher, empêchant les participants d’atteindre un état sans douleur. Favoriser l’amélioration des capacités physiques semble aussi être une stratégie pour maximiser l’effet du programme d’entraînement. / Objectives Trials investigating the efficacy exercise therapy in low back pain (LBP) patients typically yield small to moderate effect size. One possibility is that trials have been too short to observe the full potential of physical exercise. We sought to characterize the kinetic of pain during a multimodal exercise regimen to explore if participants could benefit from longer exercise regimen. Methods Fifty-seven LBP patients completed a multimodal exercise regimen (aerobic and resistance exercises) or a waiting period. Physical and functional outcomes were measured prior to the intervention and one week after its completion. Pain intensity in the lower back was recorded at the beginning of each training sessions to monitor the evolution of pain during the exercise regimen. Linear mixed-effect modelling was performed to describe the kinetic of pain. Moderation analyses were performed to test whether sex, baseline pain intensity and improvement in physical capacities predicted greater pain reduction. Results Participants in the exercise group, but not the control group, improved in physical and functional outcomes. Pain decreased throughout the exercise regimen (linear trend: 𝛽 = −14.89, 𝑝 < .001). However, pain reduction slowed down as participants progressed in the training program (quadratic trend: 𝛽 = -5.48, 𝑝 = .001). Pain reduction was moderated by improvement in maximal aerobic capacities and baseline pain intensities, but not by sex. Conclusion It appears that the effect of exercise therapy reaches a floor effect, preventing participants from reaching a painless state. Designing physical training program maximizing improvements in physical capacities may be a good strategy to increase the efficacy of exercise therapy.