En undersökning av estetiska projekt i skolmiljö. I undersökningen intervjuas en musiklärare, en förskoleklasslärare och en musikterapeut som representanter för olika yrkesgrupper som arbetar med estetiska projekt i skolmiljö. Studiens syfte är att undersöka vilka påverkansfaktorer och kvalitetskriterier som beskrivs i forskning eller av studiens informanter. Perspektivet är musikpedagogiskt men även estetiskt verksamhet med andra estetiska uttryck än musik undersöks och skillnader och likheter diskuteras. I analys och diskussionsdelarna används bl.a. Anne Bamfords och Tomas Saars forskning för att förklara och sätta in informanternas utsagor i ett större sammanhang.

Made available in DSpace on 2016-12-06T17:07:10Z (GMT). No. of bitstreams: 1 DISSERTACAO_CARMINATTI.pdf: 1003035 bytes, checksum: 8564e54c742b47d3e336ac8bdd87e443 (MD5) Previous issue date: 2006-12-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / Anaerobic threshold (LAn) obtained during an incremental test with continuous effort, presumably indicate the workload corresponding to maximal lactate steady state (MSSL). Based on this present theoretical model, several non-invasive LAn derived from TCAR have been used as predictors of MSSL. Among them, the HR thresholds identified by visual inspection (PDv) and by the mathematical method (Dmáx), predicted Dmáx (Dmáxpred) and threshold velocity of 4 mmol·l-1 predicted (V4pred). The purpose of the present investigation was to ascertain the validity of these thresholds as predictors of MSSL in Futsal. Eight Futsal players (21.3 ± 3.1 years; 177.4 ± 7.7 cm; 79.4 ± 21.2 kg; 13.2 ± 5,7 % of fat) were submitted to the following field tests: 1) Incremental test of intermittent run (TCAR) performed in the shuttle run system, constituted of repetitions of 12 second runs interpolated by 6 seconds of walk, with initial speed of 9 Km·h-1 and increased of 0.6 Km·h-1 every 90 seconds until voluntary exhaustion. Variables identified in the TCAR: velocity (V) and HR of several predictors LAn; 2) Constant workload test, with duration of 32 minutes divided in 4 series of 8 minutes of intermittent run (same system applied in TCAR), with passive interval of 1 minute to collect 25 μL of blood samples and measure the HR. MSSL was defined as being the highest speed where the lactate steady-state occurred (increase not superior to 1.2 mmol·l-1 between the 8th and 32nd minute). The first constant workload test of 32 minutes was conducted with 100% of the speed of Dmáx (VDmáx) and following constant load tests were performed and speed increased 0.6 km·h-1 after each constant load test until the MSSL was attained. Variables identified in the test: velocity and HR corresponding to MSSL (VMSSL and HRMSSL). The results obtained to velocity and HR of predictor s LAn were: VPDv (13.0 ± 1.5 km·h-1), VDmáx (12.2 ± 1.4 km·h-1), VDmáxpred (12.4 ± 1.2 km·h-1), V4pred (13.3 ± 0.8 km·h-1) and HRPDv (186 ± 11 bpm), HRDmáx (178 ± 10 bpm), HRDmáxpred (183 ± 8 bpm), when compared to VMSSL (12.5 ± 1.6 km·h-1) and HRMSSL (182 ± 4 bpm) respectively, didn t show differences (p>0.05). The correlations found were significant, specially VDmáx (r = 0.98) and HRDmáx (r = 0.88), with exceptions for HRDmáxpred (r = 0.53) and V4pred (r = 0.70), both not significant. The values found in the concentration of lactate in MSSL were 4.2 ± 1.8 mmol·l-1 (1.4 to 6.7). Therefore, the conclusion is that LAn derived from TCAR are valid as predictors of MSSL in Futsal players and that the physiological responses verified in this intermittent running were similar to the present theoretical model, suggesting a generalizable model. / O Limiar anaeróbio (Lan) obtido durante um teste incremental em esforço contínuo, presumivelmente indica a carga de trabalho correspondente ao máximo steady-state de lactato (MSSL). Com base nesse modelo teórico vigente, diversos LAn não-invasivos derivados do TCAR têm sido utilizados como preditores do MSSL. Entre eles, os limiares de freqüência cardíaca identificados por inspeção visual (PDv) e pelo método matemático (Dmáx), o Dmáx predito (Dmáxpred) e a velocidade de limiar de 4 mmol·l-1 predita (V4pred). O objetivo da presente investigação foi verificar a validade desses Lan como preditores do MSSL na modalidade de Futsal. Oito jogadores de Futsal (21,3 ± 3,1 anos; 177,4 ± 7,7 cm; 79,4 ± 21,2 kg; 13,2 ± 5,7 %gordura) foram submetidos aos seguintes testes de campo: 1) Teste incremental de corrida intermitente (TCAR) realizado em sistema de "ida-e-volta", constituído de repetições de 12 segundos de corrida intercaladas por 6 segundos de caminhada, com velocidade inicial de 9 km·h-1 e incrementos de 0,6 km·h-1 a cada 90 segundos até a exaustão voluntária. Variáveis identificadas no TCAR: velocidade (V) e freqüência cardíaca (FC) dos diversos Lan preditores; 2) Teste de carga constante (TCC) com duração de 32 minutos divididos em 4 séries de 8 minutos de corrida intermitente (mesmo sistema aplicado no TCAR), com intervalo passivo de 1 minuto para coletar amostras de 25 µL de sangue e mensurar a FC. O MSSL foi definido como sendo a maior velocidade onde ocorreu steady-state de lactato (aumento não superior a 1,2 mmol·l-1 entre o 8º e 32º minuto). O primeiro TCC foi realizado com 100% da velocidade do Dmáx (VDmáx) e subsequentes TCC foram aplicados e a velocidade incrementada em 0,6 km·h-1 após cada TCC até que o MSSL foi verificado. Variáveis identificadas no TCC: V e FC correspondentes ao MSSL (VMSSL e FCMSSL). Os resultados obtidos para V e FC dos Lan preditores foram: VPDv (13,0 ± 1,5 km·h-1), VDmáx (12,2 ± 1,4 km·h-1), VDmáxpred (12,4 ± 1,2 km·h-1), V4pred (13,3 ± 0,8 km·h-1) e FCPDv (186 ± 11 bpm), FCDmáx (178 ± 10 bpm), FCDmáxpred (183 ± 8 bpm), respectivamente. Quando foram comparadas com a VMSSL (12,5 ± 1,6 km·h-1) e FCMSSL (182 ± 4 bpm), não apresentaram diferenças (p>0,05). As correlações encontradas foram significantes, com destaque para a VDmáx (r = 0,98) e FCDmáx (r = 0,88), com exceções para FCDmáxpred (r = 0,53) e V4pred (r = 0,70), ambas não significantes. Os valores encontrados de concentração de lactato no MSSL foram 4,2 ± 1,8 mmol·l-1 (1,4 a 6,7). Assim, concluiu-se que os Lan derivados do TCAR são válidos como preditores do MSSL em jogadores de Futsal e que, as respostas fisiológicas verificadas nesse sistema de corrida intermitente foram similares ao modelo teórico vigente, sugerindo um modelo generalizável.

Made available in DSpace on 2014-12-17T15:16:09Z (GMT). No. of bitstreams: 1 PalommaRSA_DISSERT.pdf: 871286 bytes, checksum: 4918cb8370bc81a4276c15ef2770900e (MD5) Previous issue date: 2010-05-19 / Universidade Federal do Rio Grande do Norte / The strength of respiratory muscle are frequently assessed by maximal inspiratory and expiratory pressure, however, the maneuvers to assess PImax and PEmax are difficult for many patients. The sniff nasal inspiratory pressure (SNIP) is a simple and noninvasive technique use to assess inspiratory muscles strength. Reference values have been previous established for SNIP in adults but no previous studies have provided reference values for SNIP in adult Brazilian population. The main objective of this study were propose reference values of SNIP for Brazilian population through establishment of relationship between anthropometric measurements, physical activity profile and SNIP and at the same time compare the values obtained with reference values previously published. We studied 117 subjects (59 male and 58 female) distributed in different age grouped 20-80 years old. The results showed on significant positive relationship between SNIP and height and negative correlation with age (p<0.05). In the multiple linear regression analysis only age continued to have an independent predictive role for the two dependent variables that correlated with SNIP. The values of SNIP found in Brazilian population were higher when compared with predict values of previous studies. The results of this study provide reference equations of SNIP for health Brazilian population from 20 to 80 years old / Os testes de avalia??o da fun??o muscular respirat?ria como as medidas de press?o respirat?ria m?xima (Press?o Inspirat?ria m?xima - PIm?x e Press?o Expirat?ria m?xima - PEm?x) s?o testes cl?ssicos de for?a muscular respirat?ria, por?m alguns indiv?duos podem expressar certa dificuldade para a execu??o dessas manobras. A Press?o Inspirat?ria Nasal Sniff (Sniff Nasal Inspiratory Pressure - Pnsn), por se tratar de uma t?cnica f?cil e n?o-invasiva, tem sido utilizada para avaliar a for?a muscular inspirat?ria. Alguns estudos determinaram valores de refer?ncia de Pnsn em adultos, por?m n?o h? relatos na popula??o brasileira. Os principais objetivos desse estudo foram propor equa??es de refer?ncia para Pnsn na popula??o brasileira para homens e mulheres, a partir da investiga??o da rela??o entre Pnsn e idade, peso, altura, ?ndice de Massa Corp?rea - IMC e padr?o de atividade f?sica habitual, bem como avaliar a Pnsn numa amostra de volunt?rios saud?veis e comparar com os valores preditos em outras popula??es. A amostra foi composta de 117 indiv?duos (59 homens e 58 mulheres), estratificados em grupos et?rios entre 20-80 anos. Os resultados evidenciaram valores significativamente maiores da Pnsn com o aumento da altura e significativamente menores com o aumento da idade (p<0,05). Ao analisar as equa??es de regress?o linear m?ltipla, apenas a idade permaneceu exercendo influ?ncia na predi??o da Pnsn e os valores obtidos de Pnsn foram superiores quando comparados aos valores preditos em outras popula??es adultas. Nesse contexto, sugere-se equa??es preditivas para Pnsn em indiv?duos brasileiros saud?veis na faixa et?ria entre 20 e 80 anos, com o intuito de minimizar discrep?ncias diagn?sticas ao comparar indiv?duos

Made available in DSpace on 2014-12-17T15:16:13Z (GMT). No. of bitstreams: 1 AngeloAPN_DISSERT.pdf: 995336 bytes, checksum: 4255a44d807a847caa19fe61283e58b9 (MD5) Previous issue date: 2011-04-15 / Background: Obesity may affect the respiratory system, causing changes in respiratory function and in the pulmonary volumes and flows. Objectives: To evaluate the influence of obesity in the movement of thoracoabdominal complex at rest and during maximal voluntary ventilation (MVV), and the contribution between the different compartments of this complex and the volume changes of chest wall between obese and non-obese patients. Materials and Methods: We studied 16 patients divided into two groups: the obese group (n = 8) and group non-obese (n = 8). The two groups were homogeneous in terms of spirometric characteristics (FVC mean: 4.97 ? 0.6 L - 92.91 ? 10.17% predicted, and 4.52 ? 0.6 L - 93.59 ? 8.05%), age 25.6 ? 5.0 and 26.8 ? 4.9 years, in non-obese and obese respectively. BMI was 24.93 ? 3.0 and 39.18 ? 4.3 kg/m2 in the groups investigated. All subjects performed breathing calm and slow and maneuver MVV, during registration for optoelectronic plethysmography. Statistical analysis: we used the unpaired t test and Mann-Whitney. Results: Obese individuals had a lower percentage contribution of the rib cage abdominal (RCa) during breathing at rest and VVM. The variation of end expiratory (EELV) and end inspiratory (EILV) lung volumes were lower in obese subjects. It has been found asynchrony and higher distortion between compartments of thoracoabdominal complex in obese subjects when compared to non-obese. Conclusions: Central obesity impairs the ventilation lung, reducing to adaptation efforts and increasing the ventilatory work / Contextualiza??o: A obesidade pode afetar o sistema respirat?rio, causando altera??es na mec?nica ventilat?ria, nos volumes e fluxos pulmonares. Objetivos: Avaliar a influ?ncia da obesidade no movimento do complexo t?raco-abdominal durante o repouso e durante a ventila??o volunt?ria m?xima (VVM), assim como a contribui??o entre os diferentes compartimentos desse complexo e as varia??es de volume da parede tor?cica e entre obesos e n?o obesos. Materiais e M?todos: Foram avaliados 16 indiv?duos divididos em dois grupos: grupo de obesos (n = 8) e grupo de eutr?ficos (n = 8). Os dois grupos foram homog?neos quanto ?s caracter?sticas espirom?tricas (m?dia de CVF: 4,97 ? 0,6 L 92,91 ? 10,17 % do predito, e 4,52 ? 0,6 L 93,59 ? 8,05 %), idade 25,6 ? 5,0 e 26,8 ? 4,9 anos, em eutr?ficos e obesos respectivamente. O IMC foi de 24,93 ? 3,0 e 39,18 ? 4,3 kg/m2, nos grupos investigados. Todos os sujeitos realizaram respira??o calma e lenta e a manobra de Ventila??o volunt?ria m?xima, durante o registro por pletismografia optoeletr?nica. Para an?lise estat?stica, foram utilizados os testes t n?o pareado e de Mann-Whitney. Resultados: Os indiv?duos obesos apresentaram menor contribui??o percentual da caixa tor?cica abdominal (RCa) durante a respira??o em repouso e na VVM. A varia??o dos volumes pulmonares expirat?rio (VEE) e inspirat?rio finais (VEI) foram menores nos sujeitos obesos. Foram constatados maiores assincronia e distor??o entre os compartimentos do complexo t?raco-abdominal nos obesos, quando comparados aos eutr?ficos. Conclus?es: A obesidade central interfere negativamente na ventila??o pulmonar, reduzindo a adapta??o aos esfor?os e incrementando o trabalho ventilat?rio

O objetivo deste estudo foi verificar se existe máxima fase estável de lactato (MFEL) nos exercícios LP e SR e analisar o comportamento de variáveis ventilatórias ventilação (Ve) e consumo de oxigênio (VO2), bem como lactacidemia, freqüência cardíaca (FC) e percepção subjetiva de esforço (PSE) na intensidade da MFEL e comparar as respostas entre os exercícios. Foram avaliados 12 homens jovens (20-33 anos) saudáveis e com experiência mínima de 6 meses em treinamento resistido, que passaram por teste de 1 repetição máxima (1RM), teste crescente para determinação do limiar anaeróbio (AT) e mais três sessões para a determinação da MFEL. Todas as sessões foram realizadas no mesmo horário do dia, separadas por 48 a 72 horas de intervalo. O valor de 1RM no LP foi de 298,0 ± 36,6 kg enquanto que no SR foi 93,7 ± 21,8 kg. A intensidade máxima atingida no teste crescente no LP foi 70,00 ± 12,25% de 1RM e no SR 50,00 ± 8,16% de 1RM, sendo esta diferença estatisticamente significativa (p0,05). A lactacidemia final também foi significativamente maior (p0,05) no LP comparada ao SR (8,36 ± 2,34 vs. 5,43 ± 1,12 mmol/L, respectivamente). O AT, expresso em percentual de 1RM, no LP foi de 27,9 ± 3,7% e no SR de 24,1 ± 4,4% de 1RM, porém esta diferença não foi estatisticamente significante. A lactacidemia no momento do teste crescente em que o AT era atingido também não apresentou diferença significativa, sendo 2,29 ± 0,58 mmol/L no LP e 2,52 ± 0,65 no SR. A intensidade da MFEL, no LP foi de 29,17 ± 7,02% de 1RM, enquanto que no SR a intensidade da MFEL foi de 21,67 ± 4,44% de 1RM, sendo esta diferença estatisticamente significativa (p0,05). No LP não houve diferença significativa entre as intensidades do AT e da MFEL (27,9 ± 3,7% e 29,2 ± 7,0% de 1RM, respectivamente). No SR intensidade do AT foi significativamente maior (p0,05) que a intensidade da MFEL (24,1 ± 3,4% e 21,7 ± 4,4% de 1RM, respectivamente). Durante a realização de exercício na MFEL, a ocorreu aumento de Ve, VO2, FC e PSE seguidos de estabilização, sem diferenças entre os exercícios. Estes resultados demonstram que é possível verificar MFEL nos exercícios LP e SR, e que no LP a intensidade é maior. As diferenças encontradas no teste crescente e na intensidade da MFEL são provavelmente causadas pelas características dos exercícios. / The purpose of the study was to verify if there is a maximal lactate steady state (MLSS) for the Leg Press (LP) and Bench Press (BP) exercises and to analyse ventilatory responses ventilation (Ve) and oxygen uptake (VO2), heart rate (HR), blood lactate concentration (BLC) and ratings of perceived exertion (RPE) to those exercises performed on MLSS intensity and to compare those responses for the exercises. 12 young healthy men with a minimal experience of 6 months of resistance training volunteered for the study. Volunteers underwent a 1 repetition maximum test (1RM), na incremental test to determine anaerobic threshold (AT) and three more sessions to determine MLSS. Session were performed on the same time of Day and separeted by a 48-72h interval. 1RM values for LP and BP were 298,0 ± 36,6kg and 93,7 ± 21,8 kg, respectively. The maximal intensity in the incremental test was 70 ± 12,25% of 1RM for LP and 50,00 ± 8,16% of 1RM for BP, which was a significant difference (p0,05). Post-test blood lactate concentration (BLS) was also significantly higher for LP (8,36 ± 2,34 vs. 5,43 ± 1,12 mmol/L, respectively) (p0,05). AT intensity and was not significantly different for LP and BP (27,9 ± 3,7% vs. 24,1 ± 3,6, respectively). BLC on AT was not significantly different for LP (2,29 ± 0,58 mmol/L) and BP (2,52 ± 0,65). MLSS intensity on LP (29,17 ± 7,02% of 1RM) was significantly higher (p0,05) compared to MFEL on BP (21,67 ± 4,44% of 1RM). When compared to AT, MLSS intensity for LP was not significantly different, but for BP it was significantly lower. During exercise on MLSS, oxygen uptake and ventilation, HR and RPE rose significantly compares to rest and then stabilized. There were no differences between exercises. These results show that it is possible to identify a MLSS on the LP and BP exercises, and that for LP this intensity is higher. The differences found between exercises can be atributted to the intrinsic caractheristics of each exercise.

Submitted by Renata Lopes (renatasil82@gmail.com) on 2016-07-20T13:18:12Z No. of bitstreams: 1 cristinamartinscoelho.pdf: 906013 bytes, checksum: d8d510c3a624b79e501915aaf5479e99 (MD5) / Approved for entry into archive by Adriana Oliveira (adriana.oliveira@ufjf.edu.br) on 2016-07-22T15:18:40Z (GMT) No. of bitstreams: 1 cristinamartinscoelho.pdf: 906013 bytes, checksum: d8d510c3a624b79e501915aaf5479e99 (MD5) / Made available in DSpace on 2016-07-22T15:18:40Z (GMT). No. of bitstreams: 1 cristinamartinscoelho.pdf: 906013 bytes, checksum: d8d510c3a624b79e501915aaf5479e99 (MD5) Previous issue date: 2011-03-29 / Introdução: A força muscular respiratória é geralmente estimada a partir das pressões geradas nas vias aéreas pela contração dos músculos respiratórios. Dentre os testes disponíveis para este fim, o mais amplamente utilizado na prática clínica é a avaliação das pressões respiratórias estáticas máximas (PREM) ao nível da boca: pressão inspiratória máxima e pressão expiratória máxima. Atualmente, recomenda-se a utilização de transdutores de pressão em substituição aos manovacuômetros aneróides durante as medidas das PREM. Entretanto, os parâmetros de definição de pressão máxima a serem empregados a partir da utilização deste tipo de equipamento ainda são motivo de debate. Uma das possíveis vantagens relacionadas à utilização dos transdutores de pressão é a visualização do próprio esforço realizado por parte dos indivíduos. Porém, não foram encontrados na literatura consultada estudos que avaliassem objetivamente os efeitos desta estratégia sobre os valores pressóricos mensurados. Objetivos: Investigar diferentes parâmetros de definição de pressão máxima descritos na literatura para as medidas das PREM, bem como avaliar a influência do estímulo visual sobre o desempenho dos voluntários durante estas medidas. Materiais e métodos: Estudo transversal, do qual participaram 49 sujeitos saudáveis, de ambos os sexos, com média de idade de 23,08 ± 2,5 anos, índice de massa corporal que não caracterizasse desnutrição ou obesidade, e função ventilatória dentro dos limites da normalidade. Os voluntários foram recrutados na comunidade acadêmica da Universidade Federal de Juiz de Fora, e todos assinaram o termo de consentimento livre e esclarecido previamente às avaliações. Para as medidas das PREM, foi utilizado um transdutor de pressão da marca EMG System do Brasil Ltda. Os testes foram realizados em duas ocasiões, com intervalo mínimo de duas semanas, com e sem a utilização do estímulo visual. Os parâmetros de definição de pressão máxima avaliados foram estimados a partir de algoritmo matemático desenvolvido para a pesquisa, a saber: pressão de pico, pressão de platô, pressão média máxima e pressão segundo a área. Além disso, foram avaliados ainda o tempo para atingir o valor de pico e a área normalizada. Para análise estatística, foram empregados a média e o desvio padrão para caracterização da amostra, além dos testes de Friedman, Wilcoxon, e da correlação de Spearman para análise das variáveis. Resultados: Foram encontradas diferenças significativas entre todos os parâmetros de definição de pressão máxima estudados (p < 0,05). Com relação à utilização do estímulo visual, este esteve relacionado a maiores valores pressóricos apenas no primeiro dia de avaliação (p < 0,05), indicando neste caso o efeito do aprendizado. Conclusão: Foram evidenciadas diferenças significativas entre todos os parâmetros de definição de pressão máxima estudados. Além disso, a utilização do estímulo visual durante os testes pareceu não resultar em melhoria do desempenho dos sujeitos avaliados. / Introduction: Respiratory muscle strength is usually estimated from the pressures generated on the airways by the respiratory muscles contraction. Among the available tests, the most widely used in clinical practice is the assessment of the maximal static respiratory pressures (MSRP) generated at the mouth: maximum static inspiratory pressure and maximum static expiratory pressure. Nowadays, the use of pressure transducers during the measurements of the MSRP, in substitution to the aneroid manometers, is recommended. However, the definition parameters of maximum pressure that should be applied when using this device are still to be defined. One of the possible advantages related to the use of pressure transducers is the real time visualization, by the subjects, of their own effort. Nevertheless, studies that objectively evaluated the effects of this strategy upon the pressure values obtained were not found in the literature. Objectives: To investigate different definition parameters of maximum pressure described in the literature for the MSRP measurements, as well as to assess the influence of the visual feedback upon the performance of the volunteers. Methods: Transversal study, in which 49 healthy subjects from both sexs took part, mean age 23,08 ± 2,5 years, body mass index that did not characterize obesity or malnutrition, and ventilatory function within normal limits. The volunteers were recruited from the academic community of the Federal University of Juiz de Fora, and all gave their informed written consent prior to the measurements. The assessments of the MSRP were made using an EMG System do Brasil Ltda. pressure transducer. The tests were conducted in two occasions, with a two-week minimum interval, with and without visual feedback. The definition parameters of maximum pressure were estimated from a mathematical algorithm developed to the research and were, namely, peak pressure, plateau pressure, mean pressure and pressure according to the area. It was also evaluated the time to reach the peak pressure and the normalized area. For statistical analysis, it was used the mean and the standard deviation for sample characterization, and the Friedman and Wilcoxon tests, as well as the Spearman correlation, for the data analysis. Results: There were found significant differences among all the definition parameters of maximum pressure studied. Regarding the tests undertaken with visual feedback, they were related to higher pressure values only in the first day of assessments (p > 0,05), indicating, in this case, the learning effect. Conclusion: There were found significant differences among all the definition parameters of maximum pressure studied. In addition, the use of visual feedback during the testes seems to be unable to improve the volunteers’ performance.

Given a set of n points P ⊂ R2, the Delaunay graph of P for a family of geometric objects C is a graph defined as follows: the vertex set is P and two points p, p' ∈ P are connected by an edge if and only if there exists some C ∈ C containing p, p' but no other point of P. Delaunay graph of circle is often called as Delaunay triangulation as each of its inner face is a triangle if no three points are co-linear and no four points are co-circular. The dual of the Delaunay triangulation is the Voronoi diagram, which is a well studied structure. The study of graph theoretic properties on Delaunay graphs was motivated by its application to wireless sensor networks, meshing, computer vision, computer graphics, computational geometry, height interpolation, etc. The problem of finding an optimal vertex cover on a graph is a classical NP-hard problem. In this thesis we focus on the vertex cover problem on Delaunay graphs for geometric objects like axis-parallel slabs and circles(Delaunay triangulation). 1. We consider the vertex cover problem on Delaunay graph of axis-parallel slabs. It turns out that the Delaunay graph of axis-parallel slabs has a very special property — its edge set is the union of two Hamiltonian paths. Thus, our problem reduces to solving vertex cover on the class of graphs whose edge set is simply the union of two Hamiltonian Paths. We refer to such a graph as a braid graph. Despite the appealing structure, we show that deciding k-vertex cover on braid graphs is NP-complete. This involves a rather intricate reduction from the problem of finding a vertex cover on 2-connected cubic planar graphs. 2. Having established the NP-hardness of the vertex cover problem on braid graphs, we pursue the question of improved fixed parameter algorithms on braid graphs. The best-known algorithm for vertex cover on general graphs has a running time of O(1.2738k + kn) [CKX10]. We propose a branching based fixed parameter tractable algorithm with running time O⋆(1.2637k) for graphs with maximum degree bounded by four. This improves the best known algorithm for this class, which surprisingly has been no better than the algorithm for general graphs. Note that this implies faster algorithms for the class of braid graphs (since they have maximum degree at most four). 3. A triangulation is a 2-connected plane graph in which all the faces except possibly the outer face are triangles, we often refer to such graphs as triangulated graphs. A chordless-NST is a triangulation that does not have chords or separating triangles (non-facial triangles). We focus on the computational problem of optimal vertex covers on triangulations, specifically chordless-NST. We call a triangulation Delaunay realizable if it is combinatorially equivalent to some Delaunay triangulation. Characterizations of Delaunay triangulations have been well studied in graph theory. Dillencourt and Smith [DS96] showed that chordless-NSTs are Delaunay realizable. We show that for chordless-NST, deciding the vertex cover problem is NP-complete. We prove this by giving a reduction from vertex cover on 3-connected, triangle free planar graph to an instance of vertex cover on a chordless-NST. 4. If the outer face of a triangulation is also a triangle, then it is called a maximal planar graph. We prove that the vertex cover problem is NP-complete on maximal planar graphs by reducing an instance of vertex cover on a triangulated graph to an instance of vertex cover on a maximal planar graph.

Nous avons réalisé une déformation non-triviale et complète de la théorie de supergravité maximale en dimension deux. Il s'agit de la supergravité maximale avec groupe de jauge SO(9). Cette théorie décrit de manière effective la supergravité de type IIA sur un espace-temps produit AdS_2 x S^8. Elle joue ainsi un rôle important dans la correspondance Gravité / Théorie de Jauge appliquée au cas de la D0-brane. Afin de préparer la construction de la supergravité maximale jaugée SO(9), nous nous intéressons aux supergravités maximales en dimension onze et trois, puisqu'elles donnent lieu à différentes formulations non équivalentes de la théorie bidimensionnelle non jaugée. Le formalisme d' « Embedding tensor » est ensuite présenté. Il permet de déterminer l'ensemble des groupes de jauges compatibles avec la supersymétrie maximale. La supergravité SO(9) est dès lors explicitement construite et ouvre la voie à deux applications importantes. P our commencer, nous avons réalisé l'inclusion d'un sous-secteur bosonique de la théorie SO(9), la troncature de Cartan, dans la supergravité de type IIA à dix dimensions d'espace-temps. Il s'agit d'une inclusion cohérente. Cela a motivé la deuxième application, de nature holographique. Ainsi, à partir du sous-secteur de Cartan de la supergravité SO(9), et en particulier de la découverte d'états fondamentaux de type « half-BPS », nous avons calculé un ensemble de fonctions de corrélation à un et deux points associées à des opérateurs de modèles de matrice duaux. Nous avons conclu en un résumé de nos travaux et en la présentation d'intéressantes perspectives. / A complete non trivial supersymmetric deformation of the maximal supergravity in two dimensions is achieved by the gauging of a SO(9) group. The resulting theory describes the reduction of type IIA supergravity on an AdS_2 x S^8 background and is of first importance in the Domain-Wall / Quantum Field theory correspondence for the D0-brane case. To prepare the construction of the SO(9) gauged maximal supergravity, we focus on the eleven dimensional supergravity and the maximal supergravity in three dimensions since they give rise to important off-shell inequivalent formulations of the ungauged theory in two dimensions. The embedding tensor formalism is presented, allowing for a general desciption of the gaugings consistent with supersymmetry. The SO(9) supergravity is explicitly constructed and applications are considered. In particular, an embedding of the bosonic sector of the two-dimensional theory into type IIA supergravity is obtained. Hence, the Cartan truncation of the SO(9) supergravity is proved to be consistent. This motivated holographic applications. Therefore, correlation functions for operators in dual Matrix models are derived from the study of gravity side excitations around half BPS backgrounds. These results are fully discussed and outlooks are presented.

Le modèle bioénergétique de P.E. di PRAMPERO permet d'expliquer la performance dans les disciplines de locomotion (course à pied, cyclisme, natation, ...) à partir d'une puissance métabolique et d'un indice de la dépense d'énergie par unité de distance parcourue. Néanmoins, pour les épreuves de natation de haute intensité telles que le 100m crawl, le contexte environnemental rend l'estimation de la puissance métabolique d'origine aérobie techniquement difficile. L'objectif de cette thèse est alors de proposer une nouvelle approche des réponses aérobies d'un 100-m nage libre, réalisé dans des conditions les plus proches possible d'une compétition. Le travail expérimental a porté sur des nageurs entraînés. Dans un bassin de 25-m, la procédure propose que les nageurs réalisent une performance sur 100-m nage libre à allure de compétition et trois épreuves (25m, 50m, 75m) réitérant les mêmes allures intermédiaires que celles du 100-m. VO2 est mesuré avant et juste après chaque épreuve, pendant 1min, par rétro-extrapolation. Les valeurs de VO2 mesurées à la fin des épreuves de 25m, 50m, 75m et 100m permettent de reconstruire la cinétique de VO2 d'une épreuve de 100-m. Les résultats contrastent avec les estimations des cinétiques de VO2 publiées précédemment : VO2 augmente plus vite dans la première moitié de l'épreuve (à 50m, VO2 ≈ 94%VO2max), atteint 100 %VO2max au 75ème mètre de l'épreuve puis chute de 7% sur le dernier 25-m. Une estimation de la contribution relative du métabolisme aérobie montre également des valeurs plus importantes que celles publiées jusqu'à ce jour, du fait de l'atteinte précoce de VO2max en cours d'épreuve. / The bioenergetic model proposed by P.E. di PRAMPERO explains performance in most human locomotions (running, cycling, swimming, ...) using indexes of metabolic power and energy cost of locomotion. Nevertheless, for 100-m front crawl events, environmental conditions make the aerobic power measurement difficult. The main purpose of this thesis is therefore to propose a new procedure to estimate aerobic responses during a 100-m front crawl event, performed in competition conditions. Trained swimmers participated to this study. In a 25-m swimming pool, the procedure includes a 100-m front crawl performance in competition conditions, and then, three tests (25-m, 50-m, 75-m) following the pacing strategy of the 100-m event. VO2 is not measured during the tests, but before and just at the end of each test with a breath-by-breath method. Each post-test VO2 (after 25m, 50m, 75m and 100m) allows to reconstruct the VO2 kinetics of the 100-m performance. The results differ from previous studies in that VO2 increases faster in the first half of the race (at 50m, VO2 ± 94%VO2max), reaches VO2max at the 75th meter; then a decrease in VO2 corresponding to 7% of VO2max appears during the last 25m. The estimation of aerobic contribution shows higher values than those previously published, because VO2max is reached very early during the race.

Dans cette thèse de doctorat, nous apportons quelques contributions à la stabilité de Lyapunov non-régulière des inclusions différentielles de premier ordre avec opérateurs monotones maximaux, dans un cadre Hilbertien de dimension infini. Nous fournissons des caractérisations explicites, primales et/ou duales, des paires de Lyapunov faibles et fortes, dont les fonctions sont semi-continues inférieurement à valeurs réelles étendues, et associées à des inclusions différentielles dont la partie de droite est gouvernée par des perturbations Lipschitziennes des opérateurs dits Cusco F, ou des opérateurs monotones maximaux A, ou les deux à la fois x(t) ∈ F(x(t}} A(x(t}} t ≥ 0, x(0) ∈ domA. De manière équivalente, nous étudions l'invariance faible et forte des ensembles fermés pour ces inclusions différentielles. Comme dans L'approche classique de Lyapunov à la stabilité des équations différentielles, les résultats présentés dans cette thèse n'utilisent que les données du système différentiel; c'est-à-dire, l'opérateur A et la multifonction F, et donc pas besoin de connaître les solutions, ni les semi-groupes générés par les opérateurs monotones en question. Parce que les paires de Lyapunov sont formées par des fonctions qui sont simplement semi-continues inférieurement, et les ensembles invariants ne sont que ensembles fermés, nous faisons usage dans cette thèse à des outils de l'analyse non-lisse, afin de fournir des critères du premier ordre, utilisant des sous-différentiels généraux et des cônes normaux. Nous fournissons une analyse similaire pour les inclusions différentielles gouvernées par le cône normal proximal à des ensembles prox-réguliers. Notre analyse ci-dessus, nous a permis de présenter ces systèmes prox-réguliers d’apparence plus générale, comme des inclusions différentielles avec opérateurs monotones maximaux. Nous utilisons aussi nos résultats pour étudier la géométrie des opérateurs monotones maximaux, et plus précisément, la caractérisation de la frontière des valeurs de ces opérateurs seulement au moyen des valeurs situées à proximité, distinctes du point de référence. Ce résultat a des applications dans la stabilité des problèmes de la programmation semi-infinie. Nous utilisons également nos résultats sur les paires de Lyapunov et les ensembles invariants pour établir une étude systématique des observateurs de type Luenberger pour des inclusions différentielles avec des cônes normaux à des ensembles prox-réguliers. / In this PhD thesis, we make some contributions to nonsmooth Lyapunov stability of first-order differential inclusions with maximal monotone operators, in the setting of infinite-dimensional Hilbert spaces. We provide primal and dual explicit characterizations for parameterized weak and strong Lyapunov pairs of lower semicontinuous extended-real-valued functions, referred to as a-Lyapunov pairs, associated to differential inclusions with right-hand-sides governed by Lipschitz or Cusco perturbationsF of maximal monotone operators A, x(t) ∈ F(x(t}} A(x(t}} t ≥ 0, x(0) ∈ domA. Equivalently, we study the weak and strong invariance of sets with respect to such differential inclusions. As in the classical Lyapunov approach to the stability of differential equations, the presented results make use of only the data of the differential system; that is, the operator A and the multifunction F, and so no need to know about the solutions, nor the semi-groups generated by the monotone operators. Because our Lyapunov pairs and invariant sets candidates are just lower semicontinuous and closed, respectively, we make use of nonsmooth analysis to provide first-order-like criteria using general subdifferentials and normal cones. We provide similar analysis to non-convex differential inclusions governed by proximal normal cones to prox-regular sets. Our analysis above allowed to prove that such apparently more general systems can be easily coined into our convex setting. We also use our results to study the geometry of maximal monotone operators, and specifically, the characterization of the boundary of the values of such operators by means only of the values at nearby points, which are distinct of the reference point. This result has its application in the stability of semi-infinite programming problems. We also use our results on Lyapunov pairs and invariant sets to provide a systematic study of Luenberger-like observers design for differential inclusions with normal cones to prox-regular sets.