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  • About
  • The Global ETD Search service is a free service for researchers to find electronic theses and dissertations. This service is provided by the Networked Digital Library of Theses and Dissertations.
    Our metadata is collected from universities around the world. If you manage a university/consortium/country archive and want to be added, details can be found on the NDLTD website.
41

The behavioral effect of laboratory turbulence on copepods

Rasberry, Katherine Denise 13 July 2005 (has links)
Copepod species are distributed throughout the ocean by many factors, including chemical, biological, and physical effects. Turbulence in the ocean has been suggested as a factor that vertically partitions some species of copepod. Copepods may seek calmer waters by sinking to deeper levels as the surface waters become more turbulent, or may maintain their position in turbulent waters. The goal of this study is to determine the behavioral effects of turbulence on three species of copepod, Calanus finmarchicus, Acartia tonsa, and Temora longicornis. Experiments consisted of exposing each of the species to stagnant water plus four levels of turbulence intensity. The experiments were conducted in a laboratory apparatus that mimics oceanic turbulence. The turbulence characteristics have been previously characterized by particle image velocimetry (PIV), that show the turbulence to be nearly isotropic and homogeneous in the observation region. Behavior responses were quantified via several measures, including the number of animals phototactically aggregating per minute, the number of escape events, the swimming speed, and the net-to-gross-displacement ratio. There are important conclusions about the effect of laboratory turbulence on copepods. The size of the copepod has a significant effect on its aggregation and swimming capability with increasing turbulence. The smaller copepods had less ability to overcome a strong flow field, and they were more likely to be advected by the stronger flow fields. Swim style also can influence how a copepod reacts to increased turbulence. If the copepod is a hop and sink traveler, then the copepod continues to hop and sink more than its cruising counterparts as turbulence increases. The cruise and sink travelers did not alter the number of escapes in response to turbulence.
42

The role of fish physiology, behaviour, and water discharge on the attraction and passage of adult sockeye salmon (Oncorhynchus nerka) at the Seton River dam fishway, British Columbia

Pon, Lucas Benjamin 05 1900 (has links)
In many rivers, dams have interrupted the connectivity of migration routes for fish. While fishways can provide access between downstream and upstream habitats, it is important that passage can occur with minimal delay, energy expenditure, and physiological stress. The research presented here is based on investigations into fishway attraction and passage for the Gates Creek sockeye salmon (Oncorhynchus nerka, Walbaum) stock at the Seton River dam in British Columbia. The first part of this thesis examined the effect of changes in water discharge from the dam on the relationship between the physiological condition of sockeye and their behaviour in approaching the fishway entrance. Fish were caught and non-lethally biopsied under three normal operating discharge conditions at Seton River dam, and subsets of sampled fish were implanted with radio transmitters and released downstream of the dam. Indices of physiological stress and exhaustive exercise (e.g. plasma cortisol, glucose, lactate, osmolality and hematocrit) did not differ among the water discharge levels that were examined. Fish delayed in the tailrace below the fishway entrance significantly longer under intermediate discharge (19.9 h @ 12.7 m³s‾¹) than either the high discharge (9.3 h @ 15.8 m³s‾¹), or the low discharge (7.0 h @11.0 m³s‾¹;) conditions (P = 0.022, and P = 0.015, respectively). Delay time was similar under high and low discharge conditions (P = 0.617), and passage success was found to be independent of discharge (P = 0.356). The second part of this thesis investigated how prior physiological condition and subsequent swimming energetics and behaviours effected fishway passage success. Fish were captured and biopsied, before being implanted with electromyogram (EMG) transmitters and released near the downstream entrance of the fishway. Very few differences existed between successful and unsuccessful fish in body size, initial plasma physiology and energy state, and mean swim speed and energy use during passage. However, plasma Na+ concentration was significantly lower in unsuccessful fish (P = 0.022), which is suggestive of a depressed ionic state for unsuccessful fish. Generally, fish did not employ burst swimming during successful or failed attempts at passage, indicating that failure was probably not related to metabolic acidosis.
43

The modulatory effects of sildenafil and the cholinergic system on antidepressant action in a rat model of depression / Johannes Daniel Clapton

Clapton, Johannes Daniel January 2006 (has links)
Sildenafil, a selective phosphodiesterase type 5 (PDE5) inhibitor, is registered for the treatment of male erectile dysfunction (Viagra®) and pulmonary hypertension (Revatio®) in the United States. PDE5 is found in the endothelium of blood vessels in the penile corpus cavernosum, pulmonary vessels and also brain and other peripheral tissue. Sildenafil crosses the blood brain barrier, leading to side-effects such as headache and dizziness, as well as behavioural manifestations including depression, anxiety and aggression (Milman & Arnold, 2002). According to the Food and Drug Administration (2001), 12378 adverse events were reported after the use of sildenafil and 274 of these reports implicated sildenafil in neurologic, emotional, or psychological disturbances between January 1998 and 21 February 2001. In addition, in vivo studies in rats indicate that sildenafil has anxiogenic and stressogenic actions (Harvey et al., 2005; Volke et al., 2003). This is a clear indication that sildenafil influences neurological processes in the brain and may influence various signalling systems, which play major roles in the neural circuitry of the above-mentioned disturbances. Recent in vitro studies in our laboratory suggest that sildenafil may potentiate cholinergic muscarinic receptor signalling (Eager, 2004). These results suggest potential depressogenic actions, since an increase in acetylcholine is associated with depression-like symptoms (El- Yousef et al., 1973). It was therefore postulated that sildenafil may in fact possess antidepressant activity that is masked by a cholinergic-driven depressogenic activity. In a study conducted by Muller and Benkert in 2000, patients reported a decrease in depression-like symptoms when treated with sildenafil for erectile dysfunction. This implied that sildenafil not only had a direct effect on erectile function in about 50-80% of men with erectile dysfunction (Langtry and Markham, 1999; Padma-Nathan, 1999) but might also improve anhedonia and depression. The substantial correlation between the International Index of Erectile Function and Epidemiologic Studies-Depression Scale scores supported this assumption (Muller & Benkert, 2000). In addition, Raffaele et al. (2002) reported an indirect improvement in depressive-like symptoms in patients treated for erectile dysfunction with idiopathic Parkinson's disease. Aims: The current study investigated the behavioural and neuroreceptor properties of sildenafil in a rat model of depression. We also investigated a hypothesis that sildenafil displays antidepressant-like properties, but which are masked by its potentiation of the cholinergic system. Methods: The experimental layout was divided into three pilot studies. Pilot Study 1 validated the FST under our laboratory conditions, Sprague-Dawley rats received saline intraperitoneally (i.p.) for 7 days, whereafter half of the rats were pre-exposed to a 15 minute swim trial, while the remaining rats were not pre-exposed. All rats were then evaluated 24 hours later in the 5 minute scored swim trial. In Pilot Study 2 Sprague-Dawley rats were treated for 3, 7 or 11 days with vehicle (control) or 20 mg/kg fluoxetine to establish the time-dependency of the onset of antidepressant-like effects in a rat model of depression. We measured immobility in the rat forced swim test (FST), as well as changes in P-adrenergic receptor (P-AR) concentration in rat frontal cortex. In pilot study 3, rats were treated for 7 days with vehicle (control), 20 mg/kg fluoxetine, 10 mg/kg sildenafil, 1 mg/kg atropine or various combinations of these drugs. Again we employed the FST and measured cortical p-AR concentration. Results: In the FST pre-exposure to a 15 minute swim trial 24 hours before the scored swim trial significantly increased immobility. Fluoxetine inhibited this development of increased immobility in FST and decreased P-AR concentration after 7 and 11 days of treatment with fluoxetine, but not after 3 days. Seven days of treatment with atropine and sildenafil alone did not exert any changes in immobility in the FST or changes in p-AR concentration. However, a combination of atropine and sildenafil exerted a significant antidepressant-like behavioural effect, comparable with fluoxetine. Moreover, the combination of atropine and fluoxetine as well as the a triple combination of fluoxetine, sildenafil and atropine was superior to fluoxetine alone. Conclusion: Muscarinic cholinergic mechanisms mask the antidepressant-like properties of sildenafil in a rat model of depression. The antidepressant properties of the combination of sildenafil and atropine are comparable to that of fluoxetine in an animal model of depression. The combination of fluoxetine with atropine, and atropine and sildenafil enhances the antidepressant-like properties of fluoxetine. / Thesis (M.Sc. (Pharmacology))--North-West University, Potchefstroom Campus, 2007.
44

The modulatory effects of sildenafil and the cholinergic system on antidepressant action in a rat model of depression / Johannes Daniel Clapton

Clapton, Johannes Daniel January 2006 (has links)
Sildenafil, a selective phosphodiesterase type 5 (PDE5) inhibitor, is registered for the treatment of male erectile dysfunction (Viagra®) and pulmonary hypertension (Revatio®) in the United States. PDE5 is found in the endothelium of blood vessels in the penile corpus cavernosum, pulmonary vessels and also brain and other peripheral tissue. Sildenafil crosses the blood brain barrier, leading to side-effects such as headache and dizziness, as well as behavioural manifestations including depression, anxiety and aggression (Milman & Arnold, 2002). According to the Food and Drug Administration (2001), 12378 adverse events were reported after the use of sildenafil and 274 of these reports implicated sildenafil in neurologic, emotional, or psychological disturbances between January 1998 and 21 February 2001. In addition, in vivo studies in rats indicate that sildenafil has anxiogenic and stressogenic actions (Harvey et al., 2005; Volke et al., 2003). This is a clear indication that sildenafil influences neurological processes in the brain and may influence various signalling systems, which play major roles in the neural circuitry of the above-mentioned disturbances. Recent in vitro studies in our laboratory suggest that sildenafil may potentiate cholinergic muscarinic receptor signalling (Eager, 2004). These results suggest potential depressogenic actions, since an increase in acetylcholine is associated with depression-like symptoms (El- Yousef et al., 1973). It was therefore postulated that sildenafil may in fact possess antidepressant activity that is masked by a cholinergic-driven depressogenic activity. In a study conducted by Muller and Benkert in 2000, patients reported a decrease in depression-like symptoms when treated with sildenafil for erectile dysfunction. This implied that sildenafil not only had a direct effect on erectile function in about 50-80% of men with erectile dysfunction (Langtry and Markham, 1999; Padma-Nathan, 1999) but might also improve anhedonia and depression. The substantial correlation between the International Index of Erectile Function and Epidemiologic Studies-Depression Scale scores supported this assumption (Muller & Benkert, 2000). In addition, Raffaele et al. (2002) reported an indirect improvement in depressive-like symptoms in patients treated for erectile dysfunction with idiopathic Parkinson's disease. Aims: The current study investigated the behavioural and neuroreceptor properties of sildenafil in a rat model of depression. We also investigated a hypothesis that sildenafil displays antidepressant-like properties, but which are masked by its potentiation of the cholinergic system. Methods: The experimental layout was divided into three pilot studies. Pilot Study 1 validated the FST under our laboratory conditions, Sprague-Dawley rats received saline intraperitoneally (i.p.) for 7 days, whereafter half of the rats were pre-exposed to a 15 minute swim trial, while the remaining rats were not pre-exposed. All rats were then evaluated 24 hours later in the 5 minute scored swim trial. In Pilot Study 2 Sprague-Dawley rats were treated for 3, 7 or 11 days with vehicle (control) or 20 mg/kg fluoxetine to establish the time-dependency of the onset of antidepressant-like effects in a rat model of depression. We measured immobility in the rat forced swim test (FST), as well as changes in P-adrenergic receptor (P-AR) concentration in rat frontal cortex. In pilot study 3, rats were treated for 7 days with vehicle (control), 20 mg/kg fluoxetine, 10 mg/kg sildenafil, 1 mg/kg atropine or various combinations of these drugs. Again we employed the FST and measured cortical p-AR concentration. Results: In the FST pre-exposure to a 15 minute swim trial 24 hours before the scored swim trial significantly increased immobility. Fluoxetine inhibited this development of increased immobility in FST and decreased P-AR concentration after 7 and 11 days of treatment with fluoxetine, but not after 3 days. Seven days of treatment with atropine and sildenafil alone did not exert any changes in immobility in the FST or changes in p-AR concentration. However, a combination of atropine and sildenafil exerted a significant antidepressant-like behavioural effect, comparable with fluoxetine. Moreover, the combination of atropine and fluoxetine as well as the a triple combination of fluoxetine, sildenafil and atropine was superior to fluoxetine alone. Conclusion: Muscarinic cholinergic mechanisms mask the antidepressant-like properties of sildenafil in a rat model of depression. The antidepressant properties of the combination of sildenafil and atropine are comparable to that of fluoxetine in an animal model of depression. The combination of fluoxetine with atropine, and atropine and sildenafil enhances the antidepressant-like properties of fluoxetine. / Thesis (M.Sc. (Pharmacology))--North-West University, Potchefstroom Campus, 2007.
45

The role of fish physiology, behaviour, and water discharge on the attraction and passage of adult sockeye salmon (Oncorhynchus nerka) at the Seton River dam fishway, British Columbia

Pon, Lucas Benjamin 05 1900 (has links)
In many rivers, dams have interrupted the connectivity of migration routes for fish. While fishways can provide access between downstream and upstream habitats, it is important that passage can occur with minimal delay, energy expenditure, and physiological stress. The research presented here is based on investigations into fishway attraction and passage for the Gates Creek sockeye salmon (Oncorhynchus nerka, Walbaum) stock at the Seton River dam in British Columbia. The first part of this thesis examined the effect of changes in water discharge from the dam on the relationship between the physiological condition of sockeye and their behaviour in approaching the fishway entrance. Fish were caught and non-lethally biopsied under three normal operating discharge conditions at Seton River dam, and subsets of sampled fish were implanted with radio transmitters and released downstream of the dam. Indices of physiological stress and exhaustive exercise (e.g. plasma cortisol, glucose, lactate, osmolality and hematocrit) did not differ among the water discharge levels that were examined. Fish delayed in the tailrace below the fishway entrance significantly longer under intermediate discharge (19.9 h @ 12.7 m³s‾¹) than either the high discharge (9.3 h @ 15.8 m³s‾¹), or the low discharge (7.0 h @11.0 m³s‾¹;) conditions (P = 0.022, and P = 0.015, respectively). Delay time was similar under high and low discharge conditions (P = 0.617), and passage success was found to be independent of discharge (P = 0.356). The second part of this thesis investigated how prior physiological condition and subsequent swimming energetics and behaviours effected fishway passage success. Fish were captured and biopsied, before being implanted with electromyogram (EMG) transmitters and released near the downstream entrance of the fishway. Very few differences existed between successful and unsuccessful fish in body size, initial plasma physiology and energy state, and mean swim speed and energy use during passage. However, plasma Na+ concentration was significantly lower in unsuccessful fish (P = 0.022), which is suggestive of a depressed ionic state for unsuccessful fish. Generally, fish did not employ burst swimming during successful or failed attempts at passage, indicating that failure was probably not related to metabolic acidosis.
46

Efeitos da suplementação de β-alanina sobre a potência anaeróbia, habilidade de esforços repetidos e desempenho no polo aquático / Effects of β-alanine supplementation on the anaerobic power, repeated efforts ability and performance in water polo

Brisola, Gabriel Motta Pinheiro [UNESP] 29 September 2016 (has links)
Submitted by GABRIEL MOTTA PINHEIRO BRISOLA null (gabriel-brisola@hotmail.com) on 2016-11-18T17:48:43Z No. of bitstreams: 1 DISSERTAÇÃO ÚLTIMA VERSÃO.pdf: 3813641 bytes, checksum: c61ebbd4c02dd51b7b1ae87320fcf1d5 (MD5) / Approved for entry into archive by Felipe Augusto Arakaki (arakaki@reitoria.unesp.br) on 2016-11-24T15:09:44Z (GMT) No. of bitstreams: 1 brisola_gmp_me_rcla.pdf: 3813641 bytes, checksum: c61ebbd4c02dd51b7b1ae87320fcf1d5 (MD5) / Made available in DSpace on 2016-11-24T15:09:44Z (GMT). No. of bitstreams: 1 brisola_gmp_me_rcla.pdf: 3813641 bytes, checksum: c61ebbd4c02dd51b7b1ae87320fcf1d5 (MD5) Previous issue date: 2016-09-29 / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / O objetivo geral do presente trabalho foi verificar o potencial ergogênico da suplementação por 4 semanas de β-alanina sobre a potência anaeróbia, habilidade de esforços repetidos e desempenho no polo aquático. 22 jogadores de elite do sexo masculino (média±dp: idade = 18±4 anos, peso = 78,5±9,5 kg e altura = 1,79±0,06 m) participaram do estudo, que foi conduzido de modo randomizado, duplo cego e placebo controlado. Os participantes foram divididos em dois grupos (β-alanina e placebo) de 11 atletas cada e foram submetidos a testes específicos (teste de habilidade de esforços repetidos (RSA) e teste máximo de 30s de salto sob o gol (30CJ)) e semi-específicos (teste de 30s máximo em nado atado (30ATADO), teste máximo de 3 minutos (All Out 3min), teste incremental máximo (GXTATADO) e performance de 200m em nado crawl (P200m)) para a modalidade e um jogo simulado para possibilitar o rastreamento das atividades realizadas por meio de filmagem. As avaliações ocorreram pré e após o período de suplementação (4 semanas). Não foram encontrados efeitos significativos de interação entre os grupos para nenhuma variável do presente estudo. No entanto, alguns ligeiros indícios de melhora com a suplementação de β-alanina foram encontrados como: (1) melhora significativa entre os momentos (pré × pós) no número total de sprints durante o jogo simulado de polo aquático; (2) efeito provavelmente benéfico (análise de inferência baseada na magnitude) para o tempo médio, pior tempo e tempo total na primeira série do teste de RSA (RSA1); (3) melhora significativa entre os momentos na força média e integral de força durante o teste 30ATADO e na P200m; (4) melhora significativa entre os momentos na força pico no teste GXTATADO. Portanto, conclui-se que a suplementação por 4 semanas de β-alanina pode promover apenas melhorar ligeiramente alguns parâmetros relacionados a habilidade de nado no polo aquático como número total de sprints em jogo simulado, tempo médio, pior tempo e tempo total no teste de RSA, força média e integral de força no 30ATADO, P200m e força crítica no GXTATADO. / The overall aim of this study was to investigate the ergogenic effect of 4 weeks β-alanine supplementation on the anaerobic power, ability to performed repeated efforts and performance of water polo. 22 male elite players (mean±SD age = 18±4 years, weight = 78.5±9.5 kg and height = 1.79±0.06 m) participated in the study, which was conducted in order randomized, double blind and placebo controlled. Participants were divided into two groups (β-alanine and placebo) of 11 athletes each and were subjected to specific tests (repeated sprint ability test (RSA) and maximum 30s jump under the goal test (30CJ)) and semi-specific (30s maximal test in tethered swimming (30TS), maximal 3 min effort (AllOut-3min), tethered swimming graded exercise test (GXTTS) and 200m in front crawl (P200m)) for the modality and a simulated game to enable tracking of the activities carried out by video record. Assessments occurred before and after the supplementation period (4 weeks). There were no significant interaction effects between the groups for any variable of this study. However, some slight improvement indications with β-alanine supplementation were found to: (1) significant improvement between moments (pre × post) the total number of sprints during the simulated game water polo; (2) probably beneficial effect (magnitude-based inference analysis) for the mean time, worst time and total time in the first series of the RSA test (RSA1); (3) significant improvement between moments for mean force and integral of force during the 30TS and P200m; (4) significant improvement between moments for peak power at GXTTS. Therefore, it is concluded that supplementation for 4 weeks of β-alanine can promote only slightly improve some parameters related to swimming ability in water polo as total number of sprints in simulated game, mean time, worst time and total time on test RSA, mean and integral of force in 30TS, P200m and critical force in GXTTS. / FAPESP: 2014/02186-7
47

Modelos mecânicos e fisiológicos do exercício nos domínios pesado e severo : comparação da potência e da resposta lactacidêmica nas condições de nado atado e desimpedido e da cinética do VO2 durante o crawl desimpedido /

Pessôa Filho, Dalton Müller. January 2010 (has links)
Orientador: Benedito Sérgio Denadai / Banca: Cassiano Merussi Neiva / Banca: Fabrizio Caputo / Banca: Emerson Franchin / Banca: Mauro Gonçalves / Resumo: Não se tem observado a preocupação com a descrição dos domínios de intensidade na natação e poucas tentativas foram realizadas para ajustar o modelo de P-tLim às condições desta modalidade de exercício. Este estudo pretendeu ajustar o modelo P-tLim à natação com o recurso do controle de cargas possibilitado pelo nado em condição atada. Assim como, seu significado fisiológico para a descrição dos domínios pesado/severo obtido pelas relações a serem estabelecidas com a velocidade crítica (VC - limite superior do domínio pesado), com a máxima fase estável do lactato (MFEL, que disputa com VC a indexação do limite superior do domínio pesado) e com a caracterização dos domínios pesado e severo pelos parâmetros de cinética e amplitude do VO2. Em um primeiro estudo, 24 nadadores (16,5 ± 2,7 anos e 67,7 ± 13,5 kg) submeteram-se à estimativa da força de arrasto (Fr = A  v2). A Fr encontrada em máxima velocidade foi fracionada para compor quatro estágios de teste, com tempos de exaustão entre 3-20 min. em crawl-atado. A VC foi estimada empregando quatro distâncias entre 200-1500m. A potência crítica atada (PCAtada) linear (81,9W) e não linear (71,1W) não se diferenciaram (  0,05) dos valores de PC linear (108,2W) e não linear (96,3W) estimados por VC linear (1,2m.s-1) e não linear (1,14m.s-1), através da equação do desempenho. Neste primeiro estudo, pode-se concluir que PCAtada é correlata a VC, podendo representar a capacidade aeróbia. No segundo estudo, dez nadadores (16,6  1,4 anos e 69,8  9,5 kg) foram submetidos às estimativas de PCAtado (equações lineares e hiperbólica de 2-parâmetros), VC (ajuste linear do tempo pela velocidade nos desempenhos de 200, 400 e 800m), PAtadaMFEL (3 ou 4 esforços entre 95 a 105% da carga em PCAtada hiperbólica) e à vMFEL (3 ou 4 esforços entre 85 a 95% do velocidade máxima do crawl nos 400m)... (Resumo completo, clicar acesso eletrônico abaixo) / Abstract: There is a lack of studies describing the domains of intensity in swimming, and few works approaches the P-tLim model in swimming. This study provided a way to assess the P-tLim model in swimming, applying the load controlled environment in full-tethered condition. The physiological meaning for the description of heavy and severe domains was established from the relationships of critical velocity (CV - upper boundary of heavy domain) to maximal lactate steady state (MLSS, conflicting with VC to demarcate the upper boundary of heavy domain), and from the descriptive characterization of kinetic and amplitude parameters of VO2. In he first study, 24 swimmers with 16.5 ± 2.7 years and 67.7 ± 13.5 kg were undertaken to drag force (Fr) estimation (Fr = A  v2). The Fr at maximal crawl velocity was the load that was fractioned to build the sets, lasting 3-20min until exhaustion. CV was calculated from distance between 200-1500m. The linear (81.9W) and non-linear (71.1W) PTethCrit were not different (  0.05) from the values of linear (108.2W) and non-linear (96.3W) PC estimative obtained from linear (1.2m.s-1) and non-linear (1.14m.s-1) CV through swim performance equation. It was conclude that PCTeth was related to CV, and reliable to indexes aerobic capacity. The second work, did analyze ten male swimmers (16.6  1.4 years and 69.8  9.5kg) that were submitted to the measurements of the CPTeth (linear and non-linear two parameters equation), CV (linear adjustment between time and velocity performance in the 200, 400 and 800m), PTethMLSS (3 or 4 trials ranging from 95 to 105% of the load at non-linear PCAtada), and vMLSS (3 or 4 trials ranging from 85 to 95% of the 400-m crawl performance). The results shown that neither CV (1.19  0.12m.s-1) nor the CPTeth (99.4  23.0W) matches the statements for MLSS, once differences were observed to the vMLSS (1.17  0.11m.s-1)... (Complete abstract click electronic access below) / Doutor
48

Análise da força de mordida, atividade eletromiográfica e espessura dos músculos masseter e temporal em nadadores de elite - modalidade Crawl / Analysis of bite force, electromiographic activity and thickness of masseter and temporal muscles in elite swimmers - crawl modality

Evandro Marianetti Fioco 12 December 2017 (has links)
O esporte aquático em todas as modalidades requer combinação de força e eficiência, pois a água tem densidade maior que o ar, e o nadador de elite que tem jornada aquática intensa com movimentos repetitivos na locomoção e respiração pode apresentar modificação de função e forma das estruturas que compõem o organismo humano. Esta pesquisa avaliou a força de mordida molar máxima, atividade eletromiográfica, eficiência mastigatória e espessura dos músculos masseter e temporal de nadadores de elite que utilizaram variações de métodos respiratórios do nado crawl para o lado direito e esquerdo, e comparou os resultados com indivíduos sedentários. Participaram 18 indivíduos na faixa etária entre 15 e 25 anos que foram distribuídos em três grupos: sedentários/controles (GC; idade média: 15,00 ± 0,98 anos; n=6); atletas que realizaram respiração para o lado esquerdo no nado crawl (GE; idade média 17,00 ± 2,44 anos; n=6) e atletas que realizaram respiração para o lado direito no nado crawl (GD; idade média 21,00 ± 2,44 anos; n=6). O dinamômetro digital Kratos foi utilizado para determinar a força de mordida molar máxima. O eletromiógrafo MyoSystem BR1 foi utilizado para avaliar a atividade eletromiográfica em repouso mandibular, lateralidade direita, lateralidade esquerda, protrusão, apertamento dental em contração voluntária máxima, mastigação habitual e não habitual (eficiência mastigatória). Foi utilizado o ultrassom Sono Site Titan para mensurar a espessura muscular em repouso e apertamento dental em contração voluntária máxima. Os dados obtidos foram tabulados e submetidos à análise estatística (SPSS 21.0, ANOVA; p ≤ 0,05). GE e GD demonstraram menor atividade eletromiográfica nas condições posturais da mandíbula quando comparados a GC. Foi observado correto padrão funcional nos movimentos mandibulares nas diferentes avaliações clínicas, com diferença significante na lateralidade direita para o músculo temporal esquerdo (p=0,04). GD e GE apresentaram maior eficiência mastigatória em relação ao GC, com diferença significante para o músculo temporal esquerdo na mastigação com uva passa (p=0,004). Não ocorreram diferenças significantes nas médias da espessura muscular e força de mordida molar entre os nadadores de elite e indivíduos sedentários. Estes resultados sugerem que nadadores de elite que utilizaram o nado crawl com métodos respiratórios variados apresentaram alterações funcionais nos músculos masseter e temporal. / All modalities of water sports require a combination of strength and efficiency, as the water has a higher density than air, and the elites swimmer has an intense aquatic journey with repetitive movements in the locomotion and breathing may present a modification of the function and shape of the body structures. This study evaluated the molar bite force, electromyographic activity, masticatory efficiency and thickness of the masseter and temporal muscle of elites swimmers used changes in respiratory methods both in right and left for crawl modality and compared the results with sedentary individuals. 18 individuals, aged between 15 and 25 years, were divided into three groups: sedentary/control (average ± SD 15.00 ± 0.98 years, n = 6; CG), athletes underwent respiration to the left side in the crawl swim (average ± SD 17.00 ± 2.44 years, n = 6; LG) and athletes who underwent respiration to the right side in the crawl swim (average ± SD 21.00 ± 2.44 years, n = 6, RG). The Kratos digital dynamometer was used to determine the molar bite force. The MyoSystem BR1 electromyograph was used to evaluate the electromyographic activity at mandibular rest, right laterality, left laterality, protrusion, maximum voluntary contraction, habitual and non-habitual mastication (masticatory efficiency). Sono Site Titan ultrasound was used to measure muscle thickness at rest and dental tightening at maximum voluntary contraction. The data were tabulated and submitted to statistical analysis (SPSS 21.0, ANOVA; P ≤ 0.05). LG and RG demonstrated lower electromyographic activity in postural conditions of the mandible when compared to CG. The correct mandibular neuroanatomic movement was observed in almost all muscles, with a significant difference in right laterality for the left temporal muscle (P=0.04). RG and LG presented greater masticatory efficiency in relation to the CG, with a significant difference for the left temporal muscle in chewing with raisins (P=0.004). There were no significant differences in the average muscle thickness and molar bite force between elite swimmers and sedentary individuals. These results suggest that elites swimmers perform crawl swimming with varied respiratory methods had functional alterations in the masseter and temporal muscles.
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Participação do sistema glutamatérgico do córtex pré-frontal medial ventral na modulação das consequências comportamentais do estresse de nado forçado / Participation of the glutamatergic system of the ventral medial prefrontal cortex in the modulation of behavioral consequences of forced swimming stress.

Vitor Silva Pereira 20 July 2011 (has links)
Acredita-se que quantidades elevadas de glutamato estejam relacionadas à neurobiologia da depressão e trabalhos recentes indicam que a quantidade de glutamato cortical está aumentada em pacientes depressivos quando comparada a indivíduos sadios. Dentre as estruturas corticais, o córtex pré-frontal medial ventral (CPFMv), dividido em infralímbico (IL) e pré-límbico (PL), tem sido mais frequentemente implicado no desenvolvimento de transtornos mentais, como a depressão. Considerando evidências de que o IL e o PL podem agir de forma diferente quanto ao controle emocional em resposta ao estresse, o presente trabalho visou avaliar a hipótese de participação da neurotransmissão glutamatérgica do CPFMv, IL e PL, no desenvolvimento das respostas comportamentais ao estresse de nado forçado, um modelo preditivo de efeitos antidepressivos. Para tal, investigamos os efeitos induzidos pela administração no IL ou no PL, de LY 235959, um antagonista dos receptores glutamatérgicos do tipo NMDA, em três momentos diferentes, em animais submetidos ao teste do nado forçado. A administração de LY 235959, no IL ou PL, produziu efeitos do tipo antidepressivo, sendo esse efeito sensível ao tempo de administração da droga em relação à exposição ao nado forçado. Sendo assim, foi observado efeito antidepressivo quando o bloqueio glutamatérgico no PL ocorreu imediatamente após o nado ou antes da re-exposição ao estresse; enquanto no IL, o tratamento promoveu efeito antidepressivo apenas quando administrado antes da re-exposição ao nado. Portanto, os resultados sugerem que a neurotransmissão glutamatérgica mediada por receptores NMDA no CPFMv contribui para o desenvolvimento de consequências comportamentais do estresse, de modo que o bloqueio desses receptores facilitaria a adaptação ao estresse e induziria efeitos do tipo-antidepressivo. Os resultados sugerem, ainda, que o PL e o IL participam de maneira semelhante na modulação desses processos. / It is believed that high amounts of glutamate are related to the neurobiology of depression. Recent studies indicate that the amount of cortical glutamate is increased in depressed patients compared to healthy subjects. Among the cortical structures, the ventral medial prefrontal cortex (CPFMv), divided into infralimbic (IL) and prelimbic (PL) has been most often implicated in the development of mental disorders, such as depression. Considering that IL and PL play different roles on the emotional control in response to stress, this study was aimed to evaluate the hypothesis that the activation of glutamate NMDA receptors within the CPFMv, IL and PL, would facilitate the development of forced swimming-induced behavioral responses, an animal model predictive of antidepressants effects. To this end, we investigated the effects induced by the administration in the PL or the IL of LY 235959, an antagonist of NMDA receptors, at three different times, in animals submitted to the forced swimming test. The administration of LY 235959, in the IL or PL, produced antidepressant-like effects, and this effect is sensitive to moment of drug administration in relation to exposure to forced swimming. Thus, the antidepressant-like effect was observed when blocking the NMDA blockade into the PL occurred immediately after swimming or before re-exposure to stress, whereas in the IL, such treatment promoted antidepressant-like effect only when administered before re-exposure to swimming. Therefore, the results suggest that the glutamatergic neurotransmission mediated by NMDA receptors in the CPFMv contributes to the development of behavioral consequences of stress, so that blocking these receptors would facilitate the adaptation to stress and induce antidepressant-like effects. The results also suggest that PL and IL may be similarly involved in modulating these processes.
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The role of fish physiology, behaviour, and water discharge on the attraction and passage of adult sockeye salmon (Oncorhynchus nerka) at the Seton River dam fishway, British Columbia

Pon, Lucas Benjamin 05 1900 (has links)
In many rivers, dams have interrupted the connectivity of migration routes for fish. While fishways can provide access between downstream and upstream habitats, it is important that passage can occur with minimal delay, energy expenditure, and physiological stress. The research presented here is based on investigations into fishway attraction and passage for the Gates Creek sockeye salmon (Oncorhynchus nerka, Walbaum) stock at the Seton River dam in British Columbia. The first part of this thesis examined the effect of changes in water discharge from the dam on the relationship between the physiological condition of sockeye and their behaviour in approaching the fishway entrance. Fish were caught and non-lethally biopsied under three normal operating discharge conditions at Seton River dam, and subsets of sampled fish were implanted with radio transmitters and released downstream of the dam. Indices of physiological stress and exhaustive exercise (e.g. plasma cortisol, glucose, lactate, osmolality and hematocrit) did not differ among the water discharge levels that were examined. Fish delayed in the tailrace below the fishway entrance significantly longer under intermediate discharge (19.9 h @ 12.7 m³s‾¹) than either the high discharge (9.3 h @ 15.8 m³s‾¹), or the low discharge (7.0 h @11.0 m³s‾¹;) conditions (P = 0.022, and P = 0.015, respectively). Delay time was similar under high and low discharge conditions (P = 0.617), and passage success was found to be independent of discharge (P = 0.356). The second part of this thesis investigated how prior physiological condition and subsequent swimming energetics and behaviours effected fishway passage success. Fish were captured and biopsied, before being implanted with electromyogram (EMG) transmitters and released near the downstream entrance of the fishway. Very few differences existed between successful and unsuccessful fish in body size, initial plasma physiology and energy state, and mean swim speed and energy use during passage. However, plasma Na+ concentration was significantly lower in unsuccessful fish (P = 0.022), which is suggestive of a depressed ionic state for unsuccessful fish. Generally, fish did not employ burst swimming during successful or failed attempts at passage, indicating that failure was probably not related to metabolic acidosis. / Forestry, Faculty of / Graduate

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