We present N-body and hydrodynamical simulations of the response of the Milky Way's baryonic disc to the presence of the Large Magellanic Cloud during a first infall scenario. For a fiducial Galactic model reproducing the gross properties of the Galaxy, we explore a set of six initial conditions for the Large Magellanic Cloud (LMC) of varying mass which all evolve to fit the measured constraints on its current position and velocity with respect to the Galactic Centre. We find that the LMC can produce strong disturbances - warping of the stellar and gaseous discs - in the Galaxy, without violating constraints from the phase-space distribution of stars in the Solar Neighbourhood. All models correctly reproduce the phases of the warp and its antisymmetrical shape about the disc's mid-plane. If the warp is due to the LMC alone, then the largest mass model is favoured (2.5 x 10(11) M-circle dot). Still, some quantitative discrepancies remain, including deficits in height of Delta Z = 0.7 kpc at R = 22 kpc and Delta Z = 0.7 kpc at R = 16 kpc. This suggests that even higher infall masses for the LMC's halo are allowed by the data. A comparison with the vertical perturbations induced by a heavy Sagittarius dSph model (10(11) M-circle dot) suggest that positive interference with the LMC warp is expected at R = 16 kpc. We conclude that the vertical structure of the Galactic disc beyond the Solar Neighbourhood may jointly be shaped by its most massive satellites. As such, the current structure of the Milky Way suggests we are seeing the process of disc heating by satellite interactions in action.

The purpose of this study was to establish a motion pattern by characterizing the kinetics and kinematics associated with the hip, knee and ankle joint of a group of healthy yoga teachers when performing three yoga postures and comparing them to three activities of daily living (ADL). A group of experienced female yoga practitioners (n = 13), with a minimum of 5 years teaching experience, between the ages of 20 to 45, performed the Lunge, Warrior II, and Triangle poses starting from Downward Dog. The kinetic and kinematic data of the yoga practitioners was collected when performing yoga postures. The step length, joint angles, range of motion (ROM), joint moments, and angular impulse in sagittal and frontal plane were studied for the hip, knee and ankle during performance. The data were averaged, descriptive statistics of the measures were obtained, and results for each posture as well as for the average yoga practice were presented in tables and figures with standard deviation. The percentages of change and effect sizes were calculated to compare yoga movements to ADL. The stride lengths were similar in the Lunge (1.98m), Warrior II (1.51m), and Triangle (1.43m). The motion patterns of the Lunge and the Warrior II poses follow similar joint angle and joint moment, and angular impulse patterns, whereas the Triangle pose creates distinctly different patterns in most joints and planes. In the Lunge and Warrior II poses, the knee joint reaches a maximal flexion angle of 73.76° and 67.69° respectively, 18% to 32% less than what is classically instructed in a yoga class. The knee reached 9.5° of extension while in Triangle pose. The hip contributed 50-70% of the angular impulse in the lower limb in all three yoga movements. When comparing to ADL, ROM was only greater in the hip in of sagittal plane motion and in the knee if frontal plane motion, and most of the joint moments of the lower extremity were notably smaller in ADL for the minimal values and notably larger for the maximal values in yoga. In conclusion, this is first time to establish the kinematics and kinetics motion patterns of three yoga movement which become a basis for further studying yoga biomechanics and its application. Moreover the motion pattern data suggests that yoga experts do not yoga as practice the Lunge and Warrior poses as classically described in yoga book for the knee and Triangle pose may place the knee in a precarious alignment. Yoga has high demanding to hip strength and ROM, which may help to improve hip strength and subsequently benefit to dynamic stability in gait.

Navigating to a previously seen target without vision was unaffected by a 30-sec delay period at the beginning of the walking task. This study investigated whether a 60-sec delay, with or without a cognitive task, would modify the accuracy of reaching an 8-meter target. Thirty young adults participated. The delay, located at 0, 4, or 7 meters, was either to wait, or to count backwards. Kinematic data of distance travelled, distance-to-target, angular deviation, and body rotation from participants’ final position were recorded with a 3-D motion analysis system. Navigation precision was not significantly different with or without a delay, and whether or not the delays contained a cognitive task. However, comparisons among delays revealed a significant effect of delay position with larger distance errors occurring at the 0-meter delay in the 16 participants who walked at least 7 meters, suggesting that a delay at the beginning was more disruptive for navigation accuracy than when it occurred closer to the target.

The formation of stars begins with the fragmentation of molecular clouds and the formation of dense cores. This fragmentation process can either be the result of classical gravitational instabilities or triggered by some external event. The gas and dust of young protoclusters often hold the imprints of the initial conditions and triggers of that specific star forming episode. In this context, my thesis work is a study of the gas properties of young protoclus- ters within the Gould Belt. The first part of my work consists of a detailed study of the young Serpens star forming region with CO isotopologues. This study has revealed a complex temperature, column density and velocity structure. I proposed a scenario where a collision between two filamentary clouds or flows is responsible for the observed complex structure and the most recent burst of star formation in Serpens. This hypothesis was tested with SPH simulations and provides a plausible scenario. I am currently extending this work to other regions with a variety of star formation efficiencies, in search of the particular physical properties and dynamics of a molecular cloud that allow or prevent clouds to be in the verge of forming stars. As such, I have included in this manuscript my study of the gas in the B59 star forming region, the only active clump in the Pipe Nebula. The results from this study have shown it to be very different from Serpens, even though further studies are needed to provide a complete picture of the region. B59 was taken as the starting point for a larger study of the entire Pipe Nebula, driven by the peculiarly low star formation efficiency in the cloud and a test to the physical properties of cores prior to star formation.

Orientador: Milton Shoiti Misuta / Dissertação (mestrado) - Universidade Estadual de Campinas, Faculdade de Ciências Aplicadas / Made available in DSpace on 2018-08-27T17:07:00Z (GMT). No. of bitstreams: 1 Teixeira-Pinto_Heber_M.pdf: 1584174 bytes, checksum: 7fda5b50bcc9e6d7c84e5b9f06c080ed (MD5) Previous issue date: 2015 / Resumo: O salto sobre a mesa da ginástica artística (GA) é uma prova composta por um único elemento e de grande importância para o atleta (nas competições individuais) e para sua equipe. No salto sobre a mesa, os atletas realizam rotações em torno dos eixos corporais e utilizar de marcadores passivos para análise cinemática por videogametria é preciso um elevado número de câmeras porque a disposição das câmeras para o registro deste movimento faz com que os iluminadores fiquem no campo óptico de outras câmeras. Para resolver este problema desenvolvemos um marcador ativo de LED para atender as necessidades da modalidade utilizando LED de alto brilho e baterias individuais. Fizemos a validação do marcador comparando-o com marcadores utilizados em sistemas de análise cinemática e utilizamos os marcadores desenvolvidos para obter um modelo de representação corporal para análise do salto sobre a mesa. Os resultados mostram que o marcador ativo desenvolvido de 10mm pode ser utilizado em volumes com dimensões de até 10m x 2,5m x 4m permitindo o erro médio absoluto de 2,41mm, desvio padrão de 2,84mm e exatidão de 2,86mm. Com o marcador ativo desenvolvido utilizamos menos câmeras que em outros estudos e não foram registrados 3 marcadores em cada segmento corporal no máximo 3 frames consecutivos. A maior diferença entre a avaliação antropométrica e a média dos valores obtidos foi 1,5 cm. O marcador ativo de LED desenvolvido mostrou se adequado para análise de gestos técnicos que requerem grandes volumes, como, o salto sobre a mesa. Este marcador mostra-se como uma solução para análise cinemática de movimentos que os atletas realizam rotações em torno dos eixos corporais para auxiliar na detecção de falhas e aprimorar o desempenho dos atletas / Abstract: The artistic gymnastics vaulting table is a discipline composed by a single element and it has of great importance to the athlete (on the individual competitions) and his team. In the vaulting table, the athletes do rotations around the body axis and use passive markers to kinematic analysis by videogametry it takes a large number of cameras because the arrangement of cameras to record the movement causes the illuminators stay on optical fiel of other cameras. To solve this problem we developed an active marker LED the artistic gymnastics requirements using high-brightness LED and individual batteries. We validate the marker comparing it with markers used in kinematic analysis systems and we use the developed markers to get a body representation model for kinematic analysis of vaulting table. The data show that the active marker developed 10mm can be used in volumes with dimensions of up to 10m x 2.5mx 4m allowing the mean absolute error of 2.41mm, standard deviation of 2.84mm and accuracy of 2.86mm. With the active marker developed use fewer cameras than in other studies and we cannot recorded three markers on each body segment a maximum of 3 consecutive frames. The biggest difference between anthropometric measurements and mean of values obtained was 1.5 cm. The LED active marker was is adequate for analysis of technical movements that require large volumes, as the vaulting table. This marker shows up as a solution for kinematic analysis of movements that athletes do rotations around the body axis to assist in fault detection and improve the performance of athletes / Mestrado / Biodinâmica do Movimento Humano e Esporte / Mestre em Ciências da Nutrição e do Esporte e Metabolismo

京都大学 / 0048 / 新制・課程博士 / 博士(医学) / 甲第22831号 / 医博第4670号 / 新制||医||1047(附属図書館) / 京都大学大学院医学研究科医学専攻 / (主査)教授 安達 泰治, 教授 別所 和久, 教授 妻木 範行 / 学位規則第4条第1項該当 / Doctor of Medical Science / Kyoto University / DFAM

This thesis investigates the potential benefits and challenges of using compliant mechanisms in the design of haptic interfaces. The benefits and challenges are presented with an emphasis on their inherent springback behavior and an active compensation approach. Design criteria for compliant mechanism joint candidates are reviewed and several joints are surveyed. Quantitative calculations of axial stiffness and maximum stress for five candidates are presented. Generalized analytical models of springback force and compensation torque are created to simulate the implementation of each joint candidate in a two degree-of-freedom planar pantograph. We use these models in the development and discussion of an analytical approach to predict the motor torques needed to actively compensate for the effects of springback.This approach relies on virtual work analyses of the haptic pantograph to determine the springback forces, compensation torques, haptic workspace, and available haptic force after compensation. A key to estimating the available haptic force is knowing that the force capability is different depending on the local springback force. If a component of the desired haptic force aligns with the springback force, then the two can work together, thus increasing the maximum magnitude of available haptic force beyond the nominal amount. Analytical and experimental results are presented. A detailed method of implementation is given along with a hardware demonstration of active compensation.

The tree amplitudes of string theory low-energy effective actions admit a diagrammatic expansion in terms of higher-than-cubic contact terms. These tree amplitudes can be used to build loop amplitudes using unitary cuts or the forward limit. In this thesis we study the possibility of constructing four-point cubic representations for the resulting one-loop contact terms that obey the Bern-Carrasco-Johansson (BCJ) color-kinematics relation. From the string theory effective action we study the contact terms carrying ζ2, ζ3, ζ4, and ζ5. For the even ζ2 and ζ4 cases we find that the cubic representations are incompatible with the BCJ relations, as expected from their disappearance in the closed-string effective action. We find a unique, local set of numerators at ζ3 that obey the BCJ relations. For ζ5 we find two choices of representations: one obeys BCJ but requires non-trivial contributions for the tadpole; the other contains no tadpoles but breaks one of the BCJ relations.

Introduktion: Fotisättningstyper (FST) vid löpning är associerat med prestation och löprelaterade skador. Tidigare studier har undersökt prevalensen av olika FST hos amerikanska och asiatiska löpare, men däremot inte hos svenska löpare. Syfte: Att undersöka och jämföra prevalensen av olika FST (RFS = hälisättning; MFS = mittfotisättning; FFS = framfotaisättning) hos svenska löpare mellan olika löptävlingar, distanser och med avseende på prestation. Metod: Fotisättningar spelades in i 100 bilder per sekund (fps), vid tre olika platser för både Stockholm maraton (1.2, 25, 42 km) och Göteborgs halv-maraton (7.5, 15, 20 km), baserat på 2071 personer per mätpunkt. FST bedömdes genom en frame-by-frame analys. Resultat: 12’426 observationer av fotisättningar analyserades. Den totala prevalensen av FST var 92.3% (n=11’465), 4.5% (n=559), och 3.2% (n=402), för RFS, MFS, respektive FFS, och skiljde sig mellan maraton och halv-maraton (p < .001, φc = 0.069), där det förekom högre andel RFS i det sistnämnda. FST var associerat med distans, där MFS och FFS var mer vanligt förekommande på kortare distanser jämfört med RFS (p < .001, df = 2; H = 71.524). Stratifierade analyser baserade på löptävling visade att associationen mellan FST och distans inom respektive lopp försvann för halv-maratontävlingen, men kvarstod för maratontävlingen. Slutligen så var FST associerat med prestation (p < .001, df = 2, H = 65.419) och denna kvarstod för både halv-maraton (p < .001) och maratontävlingen (p < .001) efter stratifierade analyser baserat på löptävling. Konklusion: Resultaten överenstämmer med tidigare studier på området av andra grupper löpare, och stödjer tidigare fynd att RFS är den vanligaste förekommande FST, och att FST är associerat med distans och prestation, vid hel- och halvmaraton. / Foot strike type (FST) is associated with performance and running-related injuries. Previous studies have examined the prevalence proportion of FST among predominantly American and Asian cohorts. However, no study has investigated this among a predominantly Swedish cohort. Aim: To examine and compare the prevalence proportions of FST between running races, distance and performance, among a predominantly Swedish cohort of runners. Method: FST was recorded in 100 frames per second (fps), at three different points of measure for both the Stockholm Marathon (1.2, 25, 42 km) and the Gothenburg Half-Marathon (7.5, 15, 20 km), based on 2071 individuals per point of measure. FST was assessed using frame-by-frame analysis. Results: 12’426 observations of FST were analyzed. The overall prevalence proportions of FST was 92.3% (n=11’465), 4.5% (n=559), and 3.2% (n=402), for RFS, MFS, and FFS respectively, and differed between the half-marathon and marathon (p < .001, φc = 0.069), with the latter having higher proportion of RFS. FST was associated with distance, with MFS and FFS being more common at shorter distances compared with RFS (p < .001, df = 2; H = 71.524). Stratifying the data by race type revealed that the association between FST and distance within the races disappeared within the half-marathon race, but remained for the marathon. Lastly, FST was associated with performance (p < .001), and this association remained for both the half-marathon (p < .001) and marathon (p < .001) after stratifying by race type. Conclusion: The results are consistent with previous studies on other populations, and add to the body of literature showing that RFS is the most common FST, and that FST is associated with distance and performance, for full- and half-marathon races.

The purpose of the study was to explore and determine kinetic and kinematic variables that related to D-I male sprinters maximal running velocity performance. The current study was separated into 3 individual chapters: 1.) Kinematic analysis magnitude of acceleration for braking and propulsion phases during foot contact phase at maximal speed sprinting; 2.) Using kinetic isometric mid-thigh pull variables to predict D-I male sprinters’ 60m performance; 3.) Relationship of whole and lower body angular momentum cancellation during terminal swing phase to sprint performance. Methods: for sprint measurement all the athletes were participated 2 trials of 100% effort running through 60 meters. The sprint time was measured by an electronic timing gate system. The electronic timing gate system was placed at every 10 meter intervals from the start line for 60 m. Six cameras were placed between 50 m and 60 m for kinematic data collection and analysis. Volume captured by the cameras is 7.5 m long, 1.2 m wide, and 1.95 m high. Reflective markers were attached on the body landmarks based on Vicon Nexus full body plugin model. The strength assessments were performed in a customized power rack, and kinetic values were collected via a dual force plate setup (2 separate 91 cm x 45.5 cm force plates, Roughdeck HP, Rice Lake, WI). The position for each isometric pull was established before each trial using goniometry, with each bar height corresponding to a 125±5º knee angle and a near-vertical trunk position. Results: current study partially support previous assumption that fast sprinters can minimize braking phase during foot contact phase when they are running maximal velocity. However, those minimizing effects did not impact maximal running velocity performance. Second, the study showed that fast sprinters can produce greater force during a short period of time than slower sprinters. Moreover, a certain trend of statistical significance was observed from the third study that angular momentum cancellation between lower bodies at frontal plane may be related to maximal running velocity performance. Discussion: the current study confirmed that fast sprinters can produce greater force in a short period time. However, the current study did not show statistical significance of angular momenta cancellation and sprint performance. Only a level of trend was observed. Thus, further study should examine sprinters with different training background, especially elite level sprinters is definitely needed.