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Introduction : En cyclisme, la résistance aérodynamique est la force principale qui s’oppose à son déplacement et devient non négligeable dès 10 m/s. La surface de traînée (CDAP) constitue un facteur important de cette dernière et varie en fonction de la surface frontale (AP). Ce projet de recherche veut évaluer la fiabilité et la validité d’une méthode de mesure accessible de la surface frontale (AP). Méthode : 14 cyclistes ont été sélectionnés : 31  14 ans; 177,21  6,73 cm; 74,83  8,97 kg et divisés en deux groupes, amateurs et experts. La méthode par digitalisation est utilisée pour l’évaluation de Ap et une méthode par régression linéaire est utilisée pour CDAP en utilisant le logiciel MATLAB_R2019. Résultats : la surface frontale obtenue est AP = P1, 0,433  0,05 m2; P2, 0,413  0,04 m2; P3, 0,387  0,05 m2 avec un ICC intra ; 0,998, et un ICC inter ; 0,523 (p < 0,05). Pour CDAP = P1, 0,414  0,07 m2; P2, 0,435  0,14 m2; P3, 0,399  0,12 m2 avec une variation de R = 0,10 à 0,34. Conclusion : la mesure de AP avec une méthode simple est valide et fiable, mais la précision varie selon l’expertise de l’opérateur. La faible corrélation entre AP et CDAP montre que AP ne devrait pas être la seule variable à laquelle nous pouvons nous fier pour améliorer CDAP. L’évaluation de la surface frontale projetée par digitalisation permettrait d’améliorer la performance aérodynamique en cyclisme. D’autres recherches d’optimisation des outils d’évaluation aérodynamique permettraient d’obtenir des résultats plus précis. / Introduction : In the cycling world, aerodynamic resistance is the principal force that oppose a moving cyclist and is most important at 10 m/s. Drag area (CDAP) is an important factor of this force and depends of the frontal area (AP). This project wants to evaluate the reliability and the validity of an accessible method of measurements of the frontal area (AP). Method : 14 cyclists were selected : 31  14 years; 177,21  6,73 cm; 74,83  8, 97 kg and divided in two groupes, amateurs et experts. The digital method is used for the evaluation of Ap and a linear regression is used with MATLAB_R2019 for finding CDAP. Résults : the obtained frontal area AP = P1, 0,433  0,05 m2; P2, 0,413  0,04 m2; P3, 0,387  0,05 m2 with an ICC intra-operator; 0,998, and an ICC inter-operator; 0,523 (p < 0,05). Pour CDAP = P1, 0,414  0,07 m2; P2, 0,435  0,14 m2; P3, 0,399  0,12 m2 with a correlation variation of R = 0,10 à 0, 34. Conclusion : Measuring Ap with a simple method is reliable and present good validity, but the precision will vary with the expertise of the operator. The weak correlation between AP and CDAP show that AP shouldn’t be the only variable that we have to rely to reduce CDAP. In the end, the evaluation of frontal area with a simple digital method could increase aerodynamic performance in cyclist. Although, further research on optimising aerodynamic evaluation tools would allow to obtain results that are more precise.

Most of the glacier-caused sea level rise to date has been sourced from melt and icebergs from marine-terminating glaciers. Marine-terminating glaciers drain nearly all the Greenland and Antarctic ice sheets and many polar ice caps, ice fields, and mountain glaciers. However, we previously did not know how much solid mass, or frontal ablation, was lost by these glaciers, a key component of glacier mass balance. This thesis quantifies the area change and mass loss of marine-terminating glaciers in the Northern Hemisphere from 2000 to 2020 by quantifying glacier retreat, advance, and frontal ablation. In total, the 1704 marine-terminating glaciers in the Northern Hemisphere lost an average of 389.7 ± 1.6 km² a⁻¹ of their terminus from 2000 to 2020, for a total of 7527 ± 31 km², with 123 glaciers ceasing to be marine-terminating over this period. Overall, 85.3% of glaciers retreated, 2.5% advanced, and the remaining 12.3% did not change outside of uncertainty limits. Frontal ablation of marine-terminating glaciers, not including the Greenland Ice Sheet, contributed an average of 44.47 ± 6.23 Gt a⁻¹ of ice to the ocean from 2000 to 2010, and 51.98 ± 4.62 Gt a⁻¹ from 2010 to 2020. Ice discharge from 2000 to 2020 was equivalent to 2.10 ± 0.22 mm of sea-level rise and comprised approximately 79% of frontal ablation, with the remainder from terminus retreat. In Greenland, frontal ablation totaled 522.00 ± 17.38 Gt a⁻¹ for 2000-2010 and 559.05 ± 12.59 Gt a⁻¹ for 2010-2020. Ice discharge comprised ~90% of frontal ablation during both periods, while volume loss due to terminus retreat comprised the remainder. In total, Greenland accounted for 90% of northern hemisphere frontal ablation from 2000 to 2020. When combined with climatic-basal mass balance estimates this allows for the first estimate of complete Northern Hemisphere glacier mass budgets, which shows that Arctic Russia, Greenland, and Svalbard have positive climatic-basal balances. For the first time, this thesis provides complete frontal ablation estimates for the entire Northern Hemisphere of 522.0 ± 17.4 Gt a⁻¹ for 2000-2010 and 559.1 ± 12.6 Gt a⁻¹ for 2010-2020.

Rats were administered nicotine (0.3 mg/kg) for 11 consecutive days before and after an electrolytic medial frontal cortex lesion. Behavioral testing was arranged so that the rats were tested on the RAM 1 day after drug administration followed by behavioral testing on the MWT 19 days after drug treatment, or tested on the MWT 1 day after drug administration followed by testing on the RAM4 days after drug treatment. Results of MWT testing showed that regardless of the drug/behavioral testing interval, lesioned rats given nicotine demonstrated enhancement relative to saline-treated animals. Results of RAM testing showed that nicotine improved performance in non-lesioned rats compared to non-lesioned rats given saline. Four days after drug administration, nicotine improved performance in lesioned rats to levels of non-lesioned rats regardless of drug treatment. A second experiment was implemented to determine if the previous training on the MWT affected performance on the RAM.

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For adaptive goal-directed action, the brain needs to monitor action performance and detect errors. The corresponding information may be conveyed via different sensory modalities; for instance, visual and proprioceptive body position cues may inform about current manual action performance. Thereby, contextual factors such as the current task set may also determine the relative importance of each sensory modality for action guidance. Here, we analyzed human behavioral, functional magnetic resonance imaging (fMRI), and magnetoencephalography (MEG) data from two virtual reality-based hand–target phase-matching studies to identify the neuronal correlates of performance monitoring and error processing under instructed visual or proprioceptive task sets. Our main result was a general, modality-independent response of the bilateral frontal operculum (FO) to poor phase-matching accuracy, as evident from increased BOLD signal and increased source-localized gamma power. Furthermore, functional connectivity of the bilateral FO to the right posterior parietal cortex (PPC) increased under a visual versus proprioceptive task set. These findings suggest that the bilateral FO generally monitors manual action performance; and, moreover, that when visual action feedback is used to guide action, the FO may signal an increased need for control to visuomotor regions in the right PPC following errors.

No / Objective To evaluate landing strategies of female football and basketball athletes with relation to possible injury mechanisms and disparity in injury. Design Descriptive laboratory study. Participants 52 female football players and 41 female basketball players. Main outcome measures Frontal plane projection angle (FPPA) was measured during the single leg land (SLL) and drop jump (DJ) screening tasks. Results 2 × 2 × 2 mixed factorial ANOVA showed significant main effects were observed for sport, whilst significant interaction effects were seen between sport and task. Females in both sports exhibited significantly greater FPPA values during the SLL task than the DJ task (p < 0.001). Basketball players demonstrated significantly greater FPPA values during SLL than football players (p < 0.001), whilst no differences were found between sports in the DJ task (p = 0.328). Conclusion Female basketball players display greater FPPA values during unilateral landing tasks than female football players which may reflect the greater ACL injury occurrence in this population. Injury prevention programs in these athletes should incorporate unilateral deceleration and landing tasks and should consider the specific injury mechanisms in each sport.

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Made available in DSpace on 2016-03-15T19:40:41Z (GMT). No. of bitstreams: 1 Rita dos Santos de Carvalho Picinini.pdf: 1897105 bytes, checksum: 40db215aab8bca0781df1d15de88b3d3 (MD5) Previous issue date: 2009-01-27 / Fundo Mackenzie de Pesquisa / Different mathematical skills have been investigated over time and, with the advance of neuroimaging techniques, such as PET (Positron Emission Tomography) and fMRI (functional Magnetic Resonance), central components of arithmetical processing have been identified in the parietal and the pre-frontal cortices. Besides the advances of the neuroimaging techniques, other techniques such as non-invasive brain modulation have also been studied such as the transcranial magnetic stimulation (TMS) and the transcranial direct current stimulation (TDCS) in the involvement of cognitive functions in the area of calculation. This study aimed at investigating the impact of anodal TDCS applied over the left dorsolateral pre-frontal cortex (LDLPFC), right parietal cortex (RPC), left parietal cortex (LPC) while the subject was performing multiplication operations. Fifteen healthy volunteers, students of psychology, aged between 18 and 30 years old, have held subtests of the WAIS III and the multiplication task. The results showed that the anodal TDCS over the RPC improved the performance of men regarding the number of rightness. The influence of TDCS on volunteers who had worse performance took place not on complex tasks, but simple arithmetical ones. Besides, the influence of TDCS on volunteers who had better performance was in complex tasks, not simple ones. These results show that the effects of the TDCS on a certain function depend on the baseline values of each volunteer. The other stimulation conditions over the LDLPFC and LPC did not show any significant results. The TDCS can bring a beneficial effect in calculation tasks, depending on the intensity, polarity, time and location of stimulation, resulting in the increased or diminished cortex excitability. / Diferentes habilidades matemáticas vêm sendo investigadas ao longo dos tempos e, com o avanço das técnicas de neuroimagem, como PET (Tomografia por emissão de Pósitrons) e fMRI (ressonância magnética funcional) componentes centrais no processamento aritmético vêm sendo identificados em córtex parietal e pré-frontal. Além do avanço das técnicas de neuroimagem, outras técnicas como de modulação cerebral não-invasiva também vêm sendo estudadas, como Estimulação Magnética Transcraniana (EMT) e a Estimulação Transcraniana por Corrente Contínua (ETCC) no envolvimento das funções cognitivas com a área de cálculo. Este estudo teve como objetivo investigar o impacto da ETCC anódica quando aplicada no Córtex Pré-Frontal Dorsolateral (CPFDLE), Córtex Parietal Direito (CPD), Córtex Parietal Esquerdo (CPE) no desempenho em operações de multiplicação. Quinze voluntários saudáveis, estudantes de psicologia, com faixa etária entre 18 e 30 anos, realizaram subtestes do WAIS III e a tarefa de multiplicação. Os resultados desse estudo mostraram que a ETCC anódica aplicada no CPD melhorou o desempenho dos homens em relação ao número de acertos. A influência da ETCC em participantes com pior desempenho em Aritmética se deu em tarefa simples de multiplicação, mas não complexa, ao passo que a influência da ETCC em participantes com melhor desempenho em Aritmética se deu em tarefa complexa de multiplicação, mas não em simples. Tais resultados sinalizam que os efeitos da estimulação em uma determinada função dependem dos valores de linha de base de cada participante As outras condições de estimulações, CPFDLE e CPE não resultaram em efeitos significativos. A ETCC pode produzir um efeito benéfico em tarefas de cálculo, dependendo da intensidade, polaridade, tempo e localização da estimulação, podendo resultar em aumento ou diminuição na excitabilidade do córtex.

Thesis deals with the compatibility of vehicles in a frontal collision. The first section discusses about compatibility from different views. There are the physical processes used in the mechanics of impact. The second part is focused on solving the compatibility of vehicles in a frontal collision by crash analysis using the finite element method. Firstly there are described collisions of vehicles from different vehicle classes (small cars, lower middle class, Pick up / SUV) into the fixed barrier by the US NCAP. Furthermore there are simulated head-on collisions of vehicles from different vehicle classes. In the end there is shown the possibility of using data from crash tests to determine the EES.