Spelling suggestions: "subject:"bevels"" "subject:"1evels""
171 |
Efeitos literários e níveis de pertinência: o papel da literatura na obra Anatomia de um instante, de Javier Cercas / Literary effects and relevance levels: the role of literature in the work Anatomy of a moment of Javier CercasCarvalho, Guilherme Cunha de 17 February 2016 (has links)
Esta dissertação consiste em um estudo sobre os efeitos de sentido causados pelas obras literárias sob a ótica da semiótica greimasiana. O corpus analisado mais detidamente é a obra Anatomia de um romance, de Javier Cercas; também são analisados para comparação parte das obras 23-F: El golpe del Cesid, de Jesús Palacios, e Os três mosqueteiros, de Alexandre Dumas. Começando por uma reflexão sobre o objeto literário a partir do ponto de vista de uma metalinguagem não-científica, criou-se uma ponte entre a metalinguagem nãocientífica e a metalinguagem científica da semiótica greimasiana, tendo como base os conceitos desenvolvidos nos dois dicionários de semiótica. Os conceitos foram complementados pelo desenvolvimento de uma linha recente da semiótica, os níveis de pertinência. O corpus foi analisado conforme os níveis de pertinência, principalmente os níveis do texto enunciado, objeto, prática e estratégia. O efeito de sentido literário será considerado como dependente de diferentes níveis de pertinência e de forma gradual, podendo uma obra se estabelecer como mais ou menos literária dentro de um continuum. / This dissertation is a study on the effects of meaning caused by literary works from the perspective of greimasian semiotics. The corpus analyzed more closely Anatomia de um instante by Javier Cercas; They are also analyzed for comparison of the works 23-F: El golpe del CESID, Jesús Palacios, and The Three Musketeers by Alexandre Dumas. Starting with a reflection on the literary object from the point of view of an unscientific meta-language, it created a bridge between the non-scientific metalanguage and the scientific metalanguage of greimasian semiotics, based on the concepts developed in the two dictionaries semiotics. The concepts were complemented by the development of a new line of semiotics, the relevance levels. The corpus was analyzed according to the relevance levels, especially text, object, practice and strategy. The literary meaning effect will be considered as dependent on different levels of relevance and gradually, can a work be established as more or less literary within a continuum.
|
172 |
Rivermouth Ecosystem Hydrogeomorphology: Relationships Among Wetland Area, Water Levels, and StreamflowPrats, Kyra Alexandra January 2013 (has links)
Thesis advisor: Martha Carlson Mazur / Rivermouths are dynamic systems characterized by hydrologic mixing, where water, energy, sediment and nutrients from both river and receiving water unite to form a unique yet variable environment. Water levels in these environments are thus defined by, and subject to, streamflow from the river and lake-level fluctuations. Long-term fluctuations in water levels affect hydrogeomorphic structure, as well as wetland structure, distribution, and composition. A better understanding of these dynamics will help us to comprehend the processes that govern changes in wetland area and, thus, the breadth of the ecosystem services that estuarine wetlands provide. To this end, this study examined how wetland plant communities have changed through time in relation to long-term changes in water levels from both river and lake systems, using historic aerial photograph interpretation in three rivermouths on Lake Michigan. Additionally, the observed patterns of historic water levels and streamflows were used to inform our predictions for the future in light of climate changes. Results showed that higher water levels and peak streamflows led to less wetland area; average streamflow did not play a statistically detectable role in rivermouths that had lake-dominated morphologies but was significant in the rivermouth system that was riverine dominated. This suggests that varying rivermouth morphologies respond differently to lake and stream dynamics. Restoration decisions that take rivermouth morphology into account will be important as these systems continue to change both naturally and due to climate or other anthropogenic disturbances. It is important to realize not only the extent to which humans are affecting rivermouth systems, but also the interplay between water levels, streamflows, hydrogeomorphology, and wetland ecology within these systems themselves, so as to better understand the necessary steps for restoration. / Thesis (BS) — Boston College, 2013. / Submitted to: Boston College. College of Arts and Sciences. / Discipline: Geology & Geophysics Honors Program. / Discipline: Earth and Environmental Science.
|
173 |
Effects of pH and phosphorus concentrations on the cultivation of Salvia chamelaeagnea grown in hydroponicsLefever, Kerwin January 2013 (has links)
Thesis submitted in fulfilment of the requirements for the degree
Master of Technology: Horticulture
in the Faculty of Applied Sciences
at the Cape Peninsula University of Technology
2013 / This study evaluated the effects of different pH levels and supplementary phosphorous concentrations on Salvia chamelaeagnea grown in hydroponics. The treatments consisted of 12 treatments of 4 differing nutrient solutions offering: low concentration of supplementary P (control), balanced concentration of supplementary P, moderate concentration of supplementary P and a high concentration of supplementary P at 3 differing pH levels. Each treatment was replicated 10 times. The objectives of this study were to asses the effect of supplementary phosphorous concentrations and 3 different pH levels on the growth, development and chlorophyll responses of Salvia chamelaeagnea grown hydroponically. Growth and development was recorded by measuring weekly heights, numbers of basal shoots, stem diameters and the number of branches, while root length and wet and dry weights of roots and shoots were measured post harvest. Chlorophyll responses were recorded by measuring weekly SPAD-502 measurements while post harvest DMSO analysis of chlorophyll A, B and total chlorophyll were recorded along with nutrient uptake levels of N, P,K, Ca, Mg, Na, Mn, Fe, Cu, Zn and B in the plant leaves.
This study has shown that the use of a hydroponic nutrient system offering a moderate concentration of supplementary P at a pH level of 4 significantly influences the growth and development of Salvia chamelaeagnea grown in hydroponics. Plants treated with a pH level of 4 generally produced higher wet and dry shoot weights, root lengths, stem diameters, basal shoot numbers, branch numbers, and plant heights than that of the control and all treatments delivering nutrients at a pH level of 6 and 8.
Although no one treatment offering supplementary P produced consistently high results, in most cases all the plants receiving supplementary P at a pH level of 4 outperformed the pH 6 and pH 8 treatments receiving the same amount of supplementary P. This indicates that at a pH level of 4 the mineral nutrient availability of a nutrient solution is at an adequate level for the growth and development of Salvia chamelaeagnea. Furthering studies into the effects of arbuscular mycorrhiza on the uptake of mineral nutrients, root morphology and growth and development are recommended.
|
174 |
Investigation of the distribution of nitrite and nitrate and nitrite reductase activity in models of cardiovascular diseaseGhosh, Suborno Mukut January 2014 (has links)
Recently, it has emerged that the NO metabolites, nitrite and nitrate can be chemically reduced in vivo to biologically active nitric oxide (NO). This generation of NO is dependent on reduction of nitrate to nitrite by facultative anaerobes on the dorsal surface of the tongue, entry of the nitrite into the enterosalivary circuit, transit to the stomach, and absorption through the gut wall into the circulation. Conversion of nitrite to NO is then facilitated by vascular nitrite reductase enzymes. This nitrate-nitrite-NO pathway has been shown to exert a number of beneficial effects in healthy volunteers e.g. lowering of blood pressure, however whether this pathway is affected by cardiovascular disease (CVD) is currently unknown. Ozone chemiluminescence was used to determine and compare nitrite and nitrate levels in 2 models of CVD. To study atherosclerosis wild type (WT) and apolipoprotein E knock out (ApoE KO) mice were used and for hypertension wistar kyoto (WKY) rats as controls vs. spontaneously hypertensive rats (SHR). Assessment of nitrite reductase activity was conducted in the compartment which showed the most consistent differences in distribution, the red blood cell (RBC) and in homogenates of liver tissue. The impact of dietary nitrite and nitrate on distribution of the 2 anions throughout the cardiovascular system was assessed to determine the utility of this approach in restoring levels of these anions in CVD. Finally, using flow cytometry I investigated whether dietary nitrate supplementation could be used to influence inflammatory responses as a mechanism to improve CVD. Compared to WT mice, nitrate levels were reduced in ApoE KO mice in the plasma and across most of the tissues. In contrast in SHRs, reduction of the anions was only apparent in RBCs with no differences compared to WKY in all other tested tissues. Furthermore I have demonstrated that the most efficient way to restore nitrate levels back up to baseline is through a dietary nitrate strategy and that a dose of 15mM nitrate in the drinking water is sufficient to achieve this. In addition I have shown that nitrite reductase activity is enhanced in CVD particularly at the level of the RBC in both atherosclerosis and hypertension and that this enhanced activity is due, in part, to upregulation of xanthine oxidoreductase (XOR). Finally I have shown that dietary nitrate is an effective way to modulate an acute inflammatory response. This modulation is mediated through interfering with the ability of the neutrophil to firmly adhere to the vascular endothelium. These changes were shown to be dose-dependent and concomitant with dose-dependent increases in plasma nitrite and plasma nitrate. These data suggest that utilization of the nitrate-nitrite-NO pathway with dietary nitrate may represent an effective approach for the treatment of CVD.
|
175 |
Markers of iron status and cardiometabolic disease risk : an exploration of the association based on cross-sectional and prospective studies in multiple populationsSuarez Ortegon, Milton Fabian January 2017 (has links)
The aim of this thesis is to contribute to the understanding of iron metabolism, as a factor associated with cardiometabolic risk, by undertaking secondary data analyses. The objectives were to identify gaps in existing knowledge in terms of populations studied and alternative iron markers, and to attempt to fill the gaps with additional analyses and interpretation. Serum ferritin was the most widely available measure of iron status but the role of serum transferrin and soluble transferrin receptor (sTfR) levels was considered where available. I have taken a life-course approach with analyses in childhood and adulthood, and have included both intermediate factors such as the metabolic syndrome (MetS), and disease diagnoses of diabetes and cardiovascular disease as outcomes. Chapter one presents a review of empirical research literature on the relationship between iron metabolism and cardiometabolic risk, concepts surrounding iron markers and the study outcomes. This chapter also describes the gaps in understanding the iron-cardiometabolic risk relationship, which are subsequently explored in chapters two to six. Chapter two explores the link between serum ferritin and transferrin and MetS in cross-sectional and prospective studies of 725 Spanish children and 567 Chilean adolescents. I found associations between both ends of the ferritin distribution and MetS or glucose metabolism markers in different paediatric populations. For instance, whereas in the Spanish children there was a decrease of 0.02 SD units in the change of MetS score over time for every SD unit increase in ferritin, in the Chilean male adolescents being in the highest tertile of ferritin (v. the lowest) was associated with an increase of 0.25 SD units of MetS score. Furthermore, sustained high ferritin levels at various time points and gradual increase of ferritin during childhood were associated with higher MetS score in adolescence. The third chapter describes the association between serum ferritin status and MetS in adults in two cross-sectional studies of Scottish populations (2,047 individuals from Shetland Islands and 8,563 subjects from the Scottish Health Surveys (SHeS) 1995- 1998). I also examined the overall association between ferritin, MetS and each MetS component in adults, by conducting a meta-analysis and investigating potential relevant sources of heterogeneity for the association. Interestingly, ferritin levels were positively associated with MetS in the Scottish populations, but the association was not independent of the effect of covariates, mainly body mass index (BMI) and transaminase levels [Men Odds ratio (OR) 95% confidence interval (CI) 1.43(0.83- 2.46); Postmenopausal women OR (95%CI) 1.09(0.62-1.90); Premenopausal women OR (95%CI) 1.02(0.42-2.46), P > 0.05]. The meta-analysis supported this finding by describing hepatic injury markers and BMI as the major attenuating factors of the ferritin-MetS association. Chapter four investigates the association between sTfR or ferritin, and MetS in 725 Croatian adults in a cross-sectional study. There was no evidence of an association between sTfR and MetS [Men OR (95%CI) 1.35(0.90-2.02); Postmenopausal women OR (95%CI) 0.73(0.47-1.15); Premenopausal women OR (95%CI) 0.87(0.66-1.17), P > 0.05]. In contrast serum ferritin, was positively and independently associated with MetS in men and postmenopausal women (P < 0.05) [Men OR (95%CI) 1.78(1.31- 2.42); Postmenopausal women OR (95%CI) 1.71(1.12-2.62); Premenopausal women OR (95%CI) 1.24(0.85-1.80)]. These contrasting results suggest that different iron markers reflect different physiological processes other than iron metabolism. Chapter five evaluates the longitudinal association between serum ferritin and several cardiometabolic disease outcomes (CMDs) in the nationally representative SHeS 1995 and 1998 (n = 6,497). I found an independent positive longitudinal association between ferritin and cerebrovascular disease (CEVD), which was strengthened by using higher cut-points for increased ferritin [higher v. lowest sextile fully adjusted Hazard ratio(HR) 95%CI 2.08 (1.09-3.94), P=0.024], and a not significant association with coronary heart disease (CHD) after adjustment for covariates. My analyses confirmed the widely established association with type 2 diabetes (T2D) [whole sample fully adjusted HR 95% CI 1.59(1.10-2.34), P=0.006], even with serum ferritin within the normal range. The above set of observations confirm ferritin as biomarker mainly related to the development of T2D and identifies the need to investigate the association between ferritin and CEVD in other populations. Chapter six investigates whether ferritin is associated with risk for cardiovascular complications among people with T2D using cross-sectional study designs in two populations with differing baseline cardiovascular risk (Spanish study SIDIAP n=38,617) and (Edinburgh Type 2 Diabetes Study (ET2DS) n= 821) with additional analysis of follow-up data for ET2DS. Interestingly, ferritin levels were negatively associated with prevalence of cardiovascular disease, mainly CHD, in people with T2D in both studies [ET2DS OR (95%CI): 0.80(0.67-0.96), P=0.020; SIDIAP study: 0.85(0.83-0.88), P < 0.001). Ferritin was also negatively associated with incident cardiovascular disease in ET2DS: HR 95% CI: 0.39(0.16-0.93), P=0.035. Therefore, the association between iron status and CMD risk in people with T2D appears to differ from that in general populations in which a positive association has been more commonly described. In conclusion, serum ferritin is associated with cardiometabolic risk in different ways in a variety of populations. Inconsistent associations for other iron markers suggest that iron biomarkers reflect factors other than iron homeostasis that influence cardiometabolic risk. The association between iron markers and MetS appears to differ between populations. This thesis illustrates the complex relationship between iron metabolism markers, MetS and CMD, and identifies the need for further research on the topic in order to extend knowledge about pathophysiology and the potential for measures of iron status as biomarkers for CMD.
|
176 |
Grãos de sorgo secos por destilação com solúveis em dietas para frangos de corte / Sorghum dried distillers grains with solubles in broilers dietsFruchi, Viviane Murer 26 July 2013 (has links)
O sucesso da produção animal consiste em menores custos dos fatores de produção. A busca por fontes alternativas na alimentação de frangos de corte, que reduzam custos e mantenham a produtividade, é uma estratégia importante em períodos de crise do setor. Dessa forma, o presente estudo teve como objetivo avaliar os efeitos de diferentes níveis de grãos de sorgo secos por destilação com solúveis em dietas para frangos de corte sobre as características zootécnicas de desempenho (ganho de peso, consumo de ração, conversão alimentar, rendimento de carcaça e cortes), digestibilidade aparente, coloração da carne e viabilidade econômica da utilização do ingrediente. Foram realizados dois ensaios experimentais. No primeiro ensaio, 864 frangos de corte machos da linhagem Cobb, foram distribuídos em seis tratamentos, com 12 repetições de 12 aves cada, criados de 1 a 41 dias de idade para avaliação do desempenho. Aos 42 dias de idade, as aves foram abatidas e submetidas a avaliações da carcaça. No segundo ensaio experimental, 336 pintainhos foram distribuídos em seis tratamentos, com oito repetições de sete aves cada. Foi realizada a coleta de total de excretas de 16 a 19 dias de idade das aves e verificados os parâmetros de digestibilidade aparente. Os tratamentos experimentais atenderam as exigências de Rostagno et al. (2011), sendo isoprotéicas e isoenergéticas. O delineamento experimental foi inteiramente casualizado em ambos ensaios experimentais, sendo 0, 5, 10, 15, 20 e 25% de inclusão de DDGS de sorgo nas dietas. As aves apresentaram menores ganhos de peso médio (p<0,0001) com inclusões de 20 e 25% de DDGS, respectivamente, em relação aos demais tratamentos, nas dietas pré-inicial, inicial, crescimento e durante o período total de criação (1 a 41 dias). O consumo médio de ração também foi menor (p<0,0001) pelas aves com o fornecimento do nível máximo (25% de DDGS de sorgo) nas fases inicial, crescimento e durante todo o período de criação. A conversão alimentar também foi pior (p<0,0001) nas fases pré-inicial, inicial e de 1 a 41 dias nas aves que consumiram dietas com 25% de DDGS de sorgo. Inclusões de 20 ou 25% de DDGS de sorgo nas dietas resultaram em menor (p<0,0001) rendimento de carcaça e rendimento de peito. As digestibilidades aparentes da matéria seca, do extrato etéreo e da energia não diferiram entre o fornecimento de dieta convencional ou com 5% de inclusão de DDGS de sorgo na dieta (p<0,0001). A digestibilidade aparente da proteína bruta e do fósforo não diferiram (p<0,0001) com o fornecimento de dieta convencional ou com até 10% de inclusão do DDGS de sorgo. A luminosidade foi menor (p<0,0001) com inclusão de 20 ou 25% de DDGS nas dietas em relação aos demais tratamentos. Já a intensidade da cor vermelha foi maior (p=0,0009) com o maior nível de inclusão de DDGS de sorgo. A margem bruta foi menor (p<0,0001) no período total de criação com inclusão de 20 e 25% de DDGS de sorgo nas dietas, respectivamente, em relação aos demais tratamentos. É viável a inclusão de até 15% de DDGS de sorgo em dietas para frangos de corte machos. / The success of animal production is based in its lower costs of production factors. The search for alternative sources in broilers diet wich reduce costs and maintain productivity, is an important strategy in times of industry recession. Thus, the present study aimed to evaluate the effects of different levels of sorghum dried distillers grains with solubles in broilers diets on the zootechnical performance features (weight gain, feed intake, feed conversion, yield carcass and cuts), apparent digestibility, meat color and economic viability of the ingredient usage. Two experimental trials were performed. In the first trial, 864 Cobb male broilers, were distributed into six treatments, with 12 replicates of 12 birds each, raised from 1 to 41 days of age for performance evaluation. At 42 days of age, birds were slaughtered and submitted to carcass evaluations. In the second experimental trial, 336 chicks were distributed into six treatments with eight repetitions of seven chicks each. Total excreta was collected for 16-19 day old birds and checked the parameters of apparent digestibility. Experimental treatments met the requirements of Rostagno et al. (2011) and there were isoprotein and isoenergetic feed intakes. A completely randomized design was used in both experimental essays, with 0, 5, 10, 15, 20 and 25% inclusion of sorghum DDGS in diets. The birds gained less average weight (p<0.0001) with inclusions of 20 and 25% sorghum DDGS in diets, respectively, compared to other treatments, in pre-starter, starter, grower and also during the total period of growing (1-41 days). Average feed intake was also lower (p<0.0001) for the supply of birds maximum level (25% sorghum DDGS) at initial, growth and throughout the rearing period. The feed conversion ratio was also worse (p<0.0001) in the pre-starter, starter phases and 1-41 days on the birds fed with 25% sorghum DDGS in diets. Inclusions of 20 or 25% sorghum DDGS in diets resulted in lower (p<0.0001) carcass yield and breast meat yield. Apparent digestibility of dry matter, ether extract and energy did not differ between the supply of conventional diet or 5% inclusion of sorghum DDGS in the diet (p<0.0001). Apparent digestibility of crude protein and phosphorus did not differ (p<0.0001) with providing conventional diet or with up to 10% inclusion of sorghum DDGS. The brightness was lower (p<0.0001) with the inclusion of 20 or 25% DDGS in the diets compared to other treatments. Already the red color intensity was higher (p=0.0009) with the highest level of inclusion of sorghum DDGS. Gross margin was lower (p<0.0001) in the total period including 20 and 25% sorghum DDGS in diets, respectively, compared to other treatments. It is recommended to include up to 15% sorghum DDGS in broilers diets.
|
177 |
Estudo da atividade mioelétrica em exercícios isométricos com diferentes contrações / Study of myoeletric activity in isometric exercise with different contractionsEmanuele Moraes Mello 15 January 2007 (has links)
Para atividade isométrica há relativamente pouca fundamentação na literatura que aborde o contexto de sua variação em função da contração muscular. Assim, este trabalho buscou estudar exercícios isométricos realizados de formas distintas, com o objetivo de verificar variações na atividade mioelétrica. No exercício denominado dissipativo, a contração voluntária é realizada contra um fio inextensível, e no conservativo, a mesma carga é sustentada segurando um peso. Este estudo demonstrou experimentalmente que os sinais de eletromiografia de superfície são diferentes em função do tipo de força isométrica contra a qual o músculo contrai. Os resultados mostram que as diferenças entre os exercícios dissipativo e conservativo dependem do nível de força utilizado, sendo maior em níveis elevados. Os resultados levam a supor que a diferença está associada ao padrão de ativação muscular e ao tipo de fibra muscular recrutada de forma predominante, durante a execução de uma ou outra atividade. De maneira geral, as análises permitem inferir que os exercícios dissipativos apresentam maior ativação muscular e maior ativação de fibras de contração lenta. Já o conservativo, apresenta menor ativação muscular e maior ativação de fibras de contração rápida. As diferenças obtidas foram confirmadas pelas técnicas de visualização denominadas coordenadas paralelas e Viz3D. Estas apresentaram grande potencialidade para o estudo destes sinais, por possibilitar incluir os parâmetros de diferentes sujeitos e músculos como atributos dos exercícios, resultando numa avaliação globalizada. Isso permitiu afirmar que os exercícios apresentam características diferentes. / There are few studies about isometric activity at the literature that approaches the context of his variation in function of the muscle contraction. The aim of the present study is an evaluation of isometric exercises in different ways, analyzing variations at mioelectric activity. In the exercise named dissipative, the voluntary contraction pulls an inextensible wire, whereas in the exercise named conservative the same load is pulled by lifting weights. This study showed experimentally that the electromyography signals are different in function of the two kind of isometric exercises. The results show that the differences among the dissipative and conservative exercises depend on the level of force used, being larger in high levels. These results may be related to the different pattern of muscular activation and the muscular fiber type. The dissipative exercises show a larger muscular activation and larger activation of fibers of slow contraction, whereas the conservative have smaller muscular activation and larger activation of fast contraction fibers. The obtained differences were confirmed by the visualization techniques denominated parallel coordinates and Viz3D. These kind of analyses presented great potentiality for the study of these signals, making possible to include the parameters of subjects and muscles differences as exercises attributes, possibly a global evaluation. The conclusion of this work is that these two isometric exercises present different characteristics.
|
178 |
Efeitos literários e níveis de pertinência: o papel da literatura na obra Anatomia de um instante, de Javier Cercas / Literary effects and relevance levels: the role of literature in the work Anatomy of a moment of Javier CercasGuilherme Cunha de Carvalho 17 February 2016 (has links)
Esta dissertação consiste em um estudo sobre os efeitos de sentido causados pelas obras literárias sob a ótica da semiótica greimasiana. O corpus analisado mais detidamente é a obra Anatomia de um romance, de Javier Cercas; também são analisados para comparação parte das obras 23-F: El golpe del Cesid, de Jesús Palacios, e Os três mosqueteiros, de Alexandre Dumas. Começando por uma reflexão sobre o objeto literário a partir do ponto de vista de uma metalinguagem não-científica, criou-se uma ponte entre a metalinguagem nãocientífica e a metalinguagem científica da semiótica greimasiana, tendo como base os conceitos desenvolvidos nos dois dicionários de semiótica. Os conceitos foram complementados pelo desenvolvimento de uma linha recente da semiótica, os níveis de pertinência. O corpus foi analisado conforme os níveis de pertinência, principalmente os níveis do texto enunciado, objeto, prática e estratégia. O efeito de sentido literário será considerado como dependente de diferentes níveis de pertinência e de forma gradual, podendo uma obra se estabelecer como mais ou menos literária dentro de um continuum. / This dissertation is a study on the effects of meaning caused by literary works from the perspective of greimasian semiotics. The corpus analyzed more closely Anatomia de um instante by Javier Cercas; They are also analyzed for comparison of the works 23-F: El golpe del CESID, Jesús Palacios, and The Three Musketeers by Alexandre Dumas. Starting with a reflection on the literary object from the point of view of an unscientific meta-language, it created a bridge between the non-scientific metalanguage and the scientific metalanguage of greimasian semiotics, based on the concepts developed in the two dictionaries semiotics. The concepts were complemented by the development of a new line of semiotics, the relevance levels. The corpus was analyzed according to the relevance levels, especially text, object, practice and strategy. The literary meaning effect will be considered as dependent on different levels of relevance and gradually, can a work be established as more or less literary within a continuum.
|
179 |
Estudo da atividade mioelétrica em exercícios isométricos com diferentes contrações / Study of myoeletric activity in isometric exercise with different contractionsMello, Emanuele Moraes 15 January 2007 (has links)
Para atividade isométrica há relativamente pouca fundamentação na literatura que aborde o contexto de sua variação em função da contração muscular. Assim, este trabalho buscou estudar exercícios isométricos realizados de formas distintas, com o objetivo de verificar variações na atividade mioelétrica. No exercício denominado dissipativo, a contração voluntária é realizada contra um fio inextensível, e no conservativo, a mesma carga é sustentada segurando um peso. Este estudo demonstrou experimentalmente que os sinais de eletromiografia de superfície são diferentes em função do tipo de força isométrica contra a qual o músculo contrai. Os resultados mostram que as diferenças entre os exercícios dissipativo e conservativo dependem do nível de força utilizado, sendo maior em níveis elevados. Os resultados levam a supor que a diferença está associada ao padrão de ativação muscular e ao tipo de fibra muscular recrutada de forma predominante, durante a execução de uma ou outra atividade. De maneira geral, as análises permitem inferir que os exercícios dissipativos apresentam maior ativação muscular e maior ativação de fibras de contração lenta. Já o conservativo, apresenta menor ativação muscular e maior ativação de fibras de contração rápida. As diferenças obtidas foram confirmadas pelas técnicas de visualização denominadas coordenadas paralelas e Viz3D. Estas apresentaram grande potencialidade para o estudo destes sinais, por possibilitar incluir os parâmetros de diferentes sujeitos e músculos como atributos dos exercícios, resultando numa avaliação globalizada. Isso permitiu afirmar que os exercícios apresentam características diferentes. / There are few studies about isometric activity at the literature that approaches the context of his variation in function of the muscle contraction. The aim of the present study is an evaluation of isometric exercises in different ways, analyzing variations at mioelectric activity. In the exercise named dissipative, the voluntary contraction pulls an inextensible wire, whereas in the exercise named conservative the same load is pulled by lifting weights. This study showed experimentally that the electromyography signals are different in function of the two kind of isometric exercises. The results show that the differences among the dissipative and conservative exercises depend on the level of force used, being larger in high levels. These results may be related to the different pattern of muscular activation and the muscular fiber type. The dissipative exercises show a larger muscular activation and larger activation of fibers of slow contraction, whereas the conservative have smaller muscular activation and larger activation of fast contraction fibers. The obtained differences were confirmed by the visualization techniques denominated parallel coordinates and Viz3D. These kind of analyses presented great potentiality for the study of these signals, making possible to include the parameters of subjects and muscles differences as exercises attributes, possibly a global evaluation. The conclusion of this work is that these two isometric exercises present different characteristics.
|
180 |
A general study of tests and testing with special emphasis on concepts, controversy, and teaching ideas applicable at the first grade levelDimick, Jean I. 01 August 1969 (has links)
A general study of testing with special focus on, and analysis of, tests being used in the primary grades by selected cities; the controversy concerning aptitude and intelligence testing as it applies particularly to genetic factors and race; and the identification and selection of ideas which would be of value to a first grade teacher seeking diverse and unusual ways to discover abilities and aptitudes in first grade children. Study covers in detail some of the controversy about racial intelligence as it concerns black and white Americans starting with interpretations and controversies that occurred after World War I, and also with current controversy about the same topic (racial intelligence)and the relative importance of genetic and environmental factors in the interpretation of test scores. Agreement among various authorities who have contrasting ideas of genetic factors and their influence is discussed along two basic lines of agreement: the belief that almost all children can learn basic skills, and that this learning can best be accomplished if diverse learning approaches are used. Study concludes with an identification of, and detailed description of teaching techniques which could be used by a first grade teacher who sought in diverse ways to discover aptitudes and abilities in her children.
|
Page generated in 0.0595 seconds