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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.
681

Avaliação de siris da espécie Callinectes danae como biomonitores definitivos na identificação de fontes emissoras / Assessment of crabs Callinectes danae as definitive biomonitors of metal emissions

Bordon, Isabella Cristina da Costa Leal 11 April 2014 (has links)
O presente estudo teve como objetivo desenvolver uma nova proposta de uso de um biomonitor na identificação de fontes emissoras de metais no meio ambiente. Foi selecionada a espécie de siri Callinectes danae como biomonitor e o estuário de Santos como área de estudo. Numa primeira etapa e considerando que o siri é um organismo bentônico, foi realizada uma avaliação preliminar do teor de metais no sedimento do estuário. Em seguida, foi realizada uma avaliação preliminar do teor de metais nos diferentes tecidos de indivíduos coletados na região (brânquias, hepatopâncreas e músculos). Baseado nos experimentos anteriores, foi proposto um modelo de distribuição dos metais entre os tecidos e destes em relação aos sedimentos. A validação deste modelo de distribuição (assinatura química) foi realizada por meio de um conjunto de procedimentos que visaram testar: 1) a robustez em função do tempo; 2) a especificidade para a região de estudo; 3) a sensibilidade às alterações dos níveis de metais em cada tecido. A partir deste modelo, foram identificados indícios para atribuição de fontes emissoras de metais. Desta forma, concluiu-se que, para a região do estuário de Santos, o siri da espécie C. danae pode ser utilizado como um biomonitor. O modelo proposto foi eficaz, uma vez que foi capaz de responder de forma conclusiva-positiva a todos os testes realizados na sua validação, confirmando esta espécie como um biomonitor definitivo para região. A robustez do modelo irá aumentar com novas coletas e a realimentação do banco de dados. / This study aimed to develop a new methodology for the use of a biomonitor in the identification of metal discharges in environmental evaluations. Crabs of Callinectes danae species were used in an evaluation conducted in the Santos Estuarine System. In the first experiment and since C. danae is a benthic species, a preliminary assessment of the metal concentrations in sediment samples collected in the Santos Estuarine System was performed. Subsequently, a preliminary assessment of metal concentrations in the C. danae tissues was also peformed. The last experiment aimed to identify a chemical fingerprint for the Santos Estuarine System.The development of validation procedures for this model (chemical fingerprint) was conducted and aimed to test: 1) the stability of this model through time; 2) its local specificity for the Santos Estuarine System; 3) the sensibility of this model due to modifications in the metal concentrations in each tissue (gills, hepatopancreas and muscles). By the use of this model, it was possible to identify the sources of metal emissions. According to the results, C. danae can be used as a biomonitor for the Santos Estuarine System. The established model was able to responde in a positive-conclusive way to all the tests performed in its validation, confirming this species as a definitive biomonitor for this area. Thus, the stability of this model will increase with new sampling campaings and consequently introduction of new information in the database.
682

Dicas verbais na aprendizagem de uma habilidade motora: foco no componente e na interação entre os componentes / Verbal cues in the learning process of a motor skill: focus on the component and on the interaction between components

Marques, Maria Teresa da Silva Pinto 30 March 2012 (has links)
Estudos mostram que o fornecimento de dicas verbais favorece a aprendizagem de habilidades motoras. Mas há indicativos de que sua eficácia depende da associação entre o conteúdo e a natureza da tarefa. Em habilidades de alta organização, para obter sucesso não basta executar bem cada um dos componentes em separado, pois o aspecto essencial é sua interação. O objetivo deste estudo foi investigar o efeito da utilização das dicas verbais com foco no componente e na interação entre os componentes em uma habilidade classificada como de alta organização. Participaram do experimento 20 voluntários com faixa etária entre 12-14 anos, distribuídos aleatoriamente em três grupos experimentais: grupo com dicas no componente (GDC), na interação entre os componentes (GDI) e grupo controle (GC). A tarefa utilizada foi deslocar-se 8 metros nadando crawl. O nadar crawl foi escolhido como tarefa por envolver um alto nível de interação entre suas partes, já que elas (braçada, respiração e pernada) ocorrem simultaneamente. O tempo de execução da tarefa e o padrão de movimento (soma da pontuação dos componentes da lista de checagem adaptada de Pasetto, 2004) foram usadas como medidas. Para controle da amostra, foram utilizadas medidas antropométricas, estatura e massa corporal e a escala de esforço percebido de Borg. Os resultados apontaram que nesses quesitos os grupos não eram diferentes. Em relação ao bloco de entrada, foi verificado se os grupos partiram do mesmo nível de habilidade. O GDI foi o único a apresentar melhora do padrão de movimento durante a fase de aquisição (AQ1-AQ4) e manutenção do desempenho em relação ao padrão de movimento do último bloco de tentativas da fase de aquisição (AQ4) para os blocos de teste, tanto de retenção (R1 e R2) como de transferência para a velocidade máxima de nado (T1 e T2). Na medida de tempo de execução da tarefa os resultados indicaram que a prática não resultou em melhora significativa do desempenho. Esses resultados permitem concluir que no caso da habilidade nadar, em estando o aprendiz no estágio inicial de aprendizagem, somente a dica verbal com foco de atenção sobre a interação entre os componentes, mais especificamente, sobre o tempo de execução da respiração em relação à ação da braçada, é efetiva para a aquisição do padrão de movimento. Portanto, somente a dica verbal com foco na interação entre os componentes é benéfica à aprendizagem do padrão do movimento de uma habilidade motora classificada como sendo de alta organização / Studies show that providing verbal cues favors the learning of motor skills. But there are indications that their effectiveness depends on the association between the content and nature of the task. In high organization skills to succeed it is not enough to execute each component separately, because the interaction between components is the essential feature. The purpose of this study was to investigate the effect of the use of verbal cues focusing on the component and on the interaction between components in a skill classified as being high organized. 20 volunteers aged 12-14 years participated in the experiment, randomly distributed in three experimental groups: group with component cues (GDC), group with interaction between components cues (GDI) and control group (GC). The task was to swim 8 meters front crawl stroke. The front crawl stroke was chosen as the task because it involves a high level of interaction between its parts, since they (arm stroke, kick and breathing) occur simultaneously. Time needed to complete the task and the movement pattern (sum of the scores of the components of the checklist adapted from Pasetto, 2004) were used as measures. To control samples, anthropometric measures, as well as height, body mass, and the Borgs perceived effort scale were used. The results showed that at these criteria the groups were not different. In relation to the first block, it was verified that the groups started from the same skill level. The GDI was the only one to show improvement in the movement pattern during the acquisition phase (AQ1-AQ4) and maintenance of performance in relation to the movement pattern on the last block of trials of the acquisition phase (AQ4) on the test blocks, both retention (R1 and R2) and transfer blocks to maximum speed (T1 and T2). In relation to the time needed to complete the task results indicated that the practice did not result in significant improvement in performance. These results indicate that in the case of the front crawl swimming, considering a learner at the initial learning stage, only the verbal cue focusing attention on the interaction between components, more specifically on the execution time of breathing in relation to the arm stroke, is effective for the acquisition of the movement pattern. Therefore, only the verbal cue focusing on the interaction between components is beneficial to the movement pattern learning of a motor skill classified as being of high organized
683

Efeitos do treinamento físico sobre a cinética das concentrações séricas dos componentes do Complexo Ternário do IGF-I e citocinas (TNF-?, IL-6, IL-10) em nadadores adolescentes / Effects of physical training on the kinetics of IGF-I Ternary Complex components and cytokines (TNF-?, IL-6, and IL-10) in young swimmers

Pires, Marcela de Oliveira 11 August 2017 (has links)
O eixo GH/IGF-I (hormônio do crescimento - fatores de crescimento insulina-símile) é um sistema de mediadores de crescimento, receptores e proteínas de ligação que controlam o crescimento somático e tecidual em muitas espécies e programas de exercícios estão relacionados a esta função anabólica por meio da ação deste eixo. Partindo deste pressuposto, o objetivo do presente estudo foi analisar a cinética das concentrações séricas de IGF-I, IGFBP-3 e ALS, das citocinas IL-6, IL-10 e TNF-? e comparar com o desempenho físico e a composição corporal de nadadores adolescentes nas diferentes fases de uma temporada de treinamento. A amostra foi composta por 9 nadadores adolescentes do sexo masculino com idade entre 16 e 19 anos, que faziam parte de uma equipe de natação universitária da cidade de Ribeirão Preto. Os níveis de IGF-I, IGFBP-3, ALS, IL-6, IL-10 e TNF-? foram determinados na fase básica, específica e final do polimento. A fim de comparar a cinética do sistema IGF-I/IGFBP-3-ALS e das citocinas com o desempenho físico e a composição corporal dos atletas, também foram avaliadas a resistência aeróbia em nado livre, a aptidão anaeróbia em nado atado, a massa corporal, o percentual de gordura e a massa magra nos diferentes momentos da temporada. Para a análise da cinética do sistema IGF-I/IGFBP-3-ALS e das citocinas nas diferentes fases do treinamento e antes e após a sessão de treino padronizada foram utilizados os testes não-paramétricos de Friedman e Wilcoxon, respectivamente, adotando-se um nível de significância de 0,05. A correlação entre duas variáveis foi analisada por meio do coeficiente de correlação de Spearman. Resultados: o IGF-I é sensível aos efeitos agudos e crônicos do treinamento, apresentando um comportamento em duas fases ao longo da temporada - uma fase catabólica (fase específica) e uma fase anabólica (polimento). O IGFBP-3 mostrou-se sensível apenas aos efeitos crônicos do treinamento, não sendo possível identificar um comportamento diferenciado intra-fase (pré x pós). A ALS manteve-se constante, mostrando que não foi afetada pelos efeitos agudos ou crônicos do treinamento. A IL-10 mostrou-se sensível aos efeitos agudos e crônicos do treinamento, aumentando significativamente durante a fase de polimento. A IL-6 não apresentou variação significante em resposta a uma sessão de treinamento (efeito agudo), apesar disso, apresentou uma correlação negativa com o IGF-I na fase específica de treinamento. O TNF-? apresentou concentrações mais estáveis ao longo da temporada. A composição corporal e a condição cardiorrespiratória dos nadadores não foram alteradas ao longo da temporada. O Pico de Força e a Força Média acompanharam a variação do IGF-I e do IGFBP-3, ou seja, diminuíram durante a fase específica e apresentaram uma elevação significativa durante o polimento. Conclusão: o IGF-I e a IGFBP-3 podem ser considerados um dos sensíveis marcadores de estado de treinamento, podendo orientar treinadores e atletas a dosar a intensidade de treinamento, especialmente de jovens que se encontram na puberdade. Foi possível observar algumas faces de interação com as citocinas, onde a soma das ações das citocinas provavelmente explicariam as mudanças nas concentrações séricas de IGF-I e IGFBP-3. / The GH/IGF-I axis is a system of growth mediators, receptors, and binding proteins that regulate somatic and tissue growth; and it has been shown that exercise programs are related to the anabolic function of this axis. The aim of this study was to analyse the kinetics of serum IGF-I, IGFBP-3, ALS, IL-6, IL-10 and TNF-? concentration in adolescent swimmers at different stages of a training season, and compare them with physical performance parameters and body composition of the athletes. Nine male athletes, aged 16 to 19 years and who trained regularly throughout the season were included in this study. Serum IGF-I, IGFBP-3, ALS, IL- 6, IL-10, and TNF-? concentrations were recorded before and after (pre x post) standardized training sessions during the different stages of a training season (extensive x intensive x tapering). Aerobic endurance in freestyle, anaerobic fitness in tied swimming (Peak Force and Average Force), body mass, fat percentage, and lean body mass were also analysed at the different stages of training in order to compare the behaviour of the IGF-I/IGFBP/ALS system with the physical performance and body composition of the athletes. Variations in the cytokines and IGF-I/IGFBP-3/ALS system before and after a standardized training session, and at the different stages of training were analysed by the Wilcoxon and Friedman nonparametric tests, respectively. The correlation between the two variables was analysed by the Spearman\'s correlation coefficient. Significance was considered at P<0.05. Results: IGF-I was sensitive to the acute and chronic effects of training, exhibiting biphasic behaviour throughout the season. The catabolic phase was characterized by a reduction in serum IGF-I levels during the intensive stage while the anabolic phase was marked by an increase in posttraining serum IGF-I levels during the tapering stage. IGFBP-3 was only sensitive to the chronic effects of training, with a reduction in post-training serum levels during the intensive stage and an increase during the tapering stage. No difference was observed in pre- or posttraining IGFBP-3 levels at the different stages. ALS and TNF-? remained estable throughout the training season. IL-10 was sensitive to the acute and chronic effects of training, increasing significantly during the tapering phase. IL-6 showed no variation in response to a training session (acute effect); nevertheless, it had a negative correlation to IGF-I at the intensive phase. The body composition and cardiorespiratory function of the swimmers remained unaltered throughout the season. Peak Force and Average Force followed IGF-I and IGFBP-3 variations, with a decrease during the intensive stage and a significant increase during the tapering stage. The body composition and cardiorespiratory condition of the swimmers did not vary significantly throughout the season, exhibiting behaviour independent of IGF-I or IGFBP-3. Conclusion: Serum IGF-I and IGFPB-3 concentrations have proven to be sensitive markers of training status and, thus, may be used as guides for coaches and athletes in the challenging task of modulating training intensity in young athletes. The cytokine interactions observed suggest that the combined effects of these cytokines may be responsible for the serum IGF-I and IGFBP-3 variations recorded.
684

Utilisation du comportement natatoire de Daphnia magna comme indicateur sensible et précoce de toxicité pour l'évaluation de la qualité de l'eau / Use of Daphnia magna swimming behavior as a sensitive and early indicator of toxicity for water quality assessment

Chevalier, Julie 30 October 2014 (has links)
Les paramètres comportementaux sont de plus en plus considérés comme étant des indicateurs sensibles et précoces de toxicité chez les organismes aquatiques. Cependant, l’utilisation du comportement natatoire comme critère de toxicité pour l’analyse de risque environnemental ou pour le contrôle de la qualité de l’eau reste pour l’heure encore limitée. En effet, il est actuellement difficile de quantifier la sensibilité des paramètres comportementaux et d’établir un lien entre les seuils d’effets comportementaux et les effets aigus et subaigus classiquement mesurés dans les tests en écotoxicologie. Dans le but d’améliorer notre compréhension des effets comportementaux des polluants sur Daphnia magna, nous avons développé un nouveau système de mesure du comportement multi-cuves baptisé «Multi-DaphTrack ». Douze substances toxiques, couvrant une large gamme de modes d’action différents ont été testées dans ce système. Un test standard d’immobilisation ainsi que des analyses de comportement dans le toximètre DaphToxI®, ont également été effectués pour chaque substance afin de comparer les seuilsd’effets comportementaux avec les paramètres classiques d’immobilisation. Les résultats des expositions aux différentes substances ont démontré que notre nouveau système d’exposition multi-cuves permet de détecter des effets comportementaux (i.e.,augmentation de la vitesse de nage) significatifs et précoces pour l’ensemble des substances testées et ce, à des concentrations proches de la CE10(48 h) du test aigu d’immobilisation dès la première heure d’exposition. Des profils comportementaux différents ont été observés selon les substances testées (i.e., intensité, temps de latence et durée de l’effet) mais ceux-ci ne sont pas spécifiques d’un mode d’action particulier. Les résultats obtenus avec le toximètre DaphToxI®ont révélé des profils d’effet similaires (i.e.,augmentation de la vitesse de nage) bien que ce système soit globalement moins sensible par rapport au système «Multi-DaphTrack». Pour conclure, notre nouveau système d’exposition multi-cuves «Multi-DaphTrack» est un outil plus sensible et précoce que letest standard d’immobilisation pour l’évaluation de la toxicité de substances chimiques. L’utilisation du système «Multi-DaphTrack» pourrait donc être envisagée, après quelques améliorations et validation supplémentaires, pour l’évaluation de la qualité des masses d’eauet des effluents. / Swimming behavior is increasingly reported as a sensitive and early indicator of toxicant stress in aquatic organisms. However, it remains unclear how to quantify the sensitivity of swimming behavioral endpoints and how to compare these effect thresholds with standard ecotoxicological endpoints used in risk assessment. To date, the systematic assessment of the sensitivity of swimming behavioral endpoints in daphnia is limited because of the restrained test capacity of existing behavioral analysis systems. Hence, we developed a new behavioral analysis multi-cellsystemnamed “Multi-DaphTrack” with a high throughput testing capacity in order to enhance our understanding of swimming behavioral effects in Daphnia magnaunder chemical exposure. Twelve compounds covering different modes oftoxic action were selected and tested in this new system andin a single-cell commercialized biomonitor (DaphToxI®) and with the acute standard test.Our new multi-cellexposure system detectedsignificant and early swimming behavioral effects (i.e.,increase of the average speed) for most of the tested compounds and this, from the first hour of exposure at concentrations near the EC10(48h). Contrastedbehavioral profiles were observed for average speed (i.e., intensity, time of effect onset, effect duration), but no distinct behavioral profiles could be drawn from the chemical mode of action. Despite less sensitive,the DaphToxI®gave similar trends (i.e.,rapid peak increase) compared to our “Multi-DaphTrack” system. To conclude, behavior analysis using our “Multi-DaphTrack”systemcould be used as an alternative or complement to the current acute standard test for toxicity assessment of chemicals. With some additional improvements and validations, it also could be used forquality assessment of waterbodiesand sewages.
685

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.
686

The story of Riverside

Sanborn, Chloe Walker. January 1944 (has links)
Thesis (M.A.)--Southwest Texas State University, 1944. / Various newspaper articles, photographs, and other memorabilia related to Riverside mounted throughout.
687

The design of a public swimming pool for Pretoria Central.

Myburgh, Juan Pierre. January 2014 (has links)
M. Tech. Architecture (Applied) / The aim of the thesis is to design a public swimming pool that re-connects street and river within a particular urban condition. The ground plane of the selected site is manipulated to facilitate a physical and visual connection with the river. Wetlands form part of the landscape surrounding the facility and on urban scale to assist in the cleaning and re-use of water from the canal. The proposal includes two pools accommodating different human interactions with water. The buildings are designed as a transitional space between inside and outside. The site was carefully selected based on the mix of current educational facilities, offices and residential accommodation. The site was developed using various layers namely: Private swimming, public swimming, spill out spaces, as well as spectator and passer-by contact. It is envisioned that the proposal will form part of the larger Tshwane 2055 framework aiming to revitalize the Pretoria CBD, although canalized, the Aapies River forms an important life giving artery adjacent to the Nelson Mandela Corridor. As part of the design proposal, it is envisioned that the canal be used as a floating walkway in future with follies linking specific sites and the river at strategic points. The proposed lap pool adheres to international standards. Both the pools step towards the canal, providing a different spatial and sensory experience. The design may serve as a guideline for future proposals along the canal. URBAN SWIMMING must inspire social growth and promote swimming as both a sport and a recreational activity.
688

Lietuvos kūno kultūros akademijos baseino teikiamų paslaugų pasirinkimo ypatumai / Peculiarities of rendering services selection by the swimming pool of Lithuanian academy of physical education

Stalygienė, Laima 16 August 2007 (has links)
Darbo objektas: Lietuvos kūno kultūros akademijos teikiamų baseino komercinių paslaugų pasirinkimo ypatumai. Aktualumas: paslaugoms būdingi kiti ypatumai nei materialinėms vertybėms. Šiuos ypatumus lemia paslaugų verslo prigimtis ir paslaugų savybės: jų neapčiuopiamumas, nedalijamumas (t. y. neatskiriamumas nuo teikimo šaltinių), epizodiškumas, kokybės nepastovumas ir kt. Paslaugų savybių visuma lemia nevienodą paslaugų kokybę ir sudėtingą jos vertinimą. Norint įvertinti paslaugų kokybę, pirmiausia būtina išsiaiškinti, kaip ją suvokia klientai. Tik tuomet paslaugų teikėjas galės kontroliuoti ir koreguoti šiuos vertinimus norima linkme. Neatsižvelgiant į klientų nuomonę dėl kokybės, galima suklysti, o išleisti pinigai ir laikas bus prarasta investicija. Paslaugos šiandien atsidūrė ekonominės veiklos dėmesio centre: jos tampa privaloma priemone siekiant patenkinti svarbiausius norus bei reikmes ir kelti visuomenės gerovę (Kindurys, 1998), tačiau ekonominiu aspektu LKKA teikiamos baseino paslaugos šiame darbe neanalizuojamos. Paslaugos pasirinkimo motyvai kiekvieno vartotojo yra individualūs. Vartotojo reikšmingumas įpareigoja paslaugų teikėjus nuodugniai išanalizuoti visus veiksnius ir imtis reikiamų sprendimų, susijusių su paslaugų kokybės tobulinimu. Todėl norint teikti atitinkamos kokybės paslaugas, svarbu žinoti, kokie motyvai vartotojams yra svarbiausi renkantis paslaugų teikėją ir kokiais kriterijais remdamasis jis suvokia gaunamos paslaugos kokybę. Šio darbo... [toliau žr. visą tekstą] / An object of the work: peculiarities of selection rendering commercial services by the swimming pool of Lithuanian Academy of Physical Education. Relevance: Services, compare it to material values, are incident to particular peculiarities. Those peculiarities are determined by the nature of service business, services characteristics, for instance, its impalpability, indivisibility that is inherency of its rendering derivation, transience and impermanence of their quality and etc. Totality of services characteristics determine complicated quality of services and even more complicated its evaluation. First of all on purpose to evaluate the quality of services it is necessary to ascertain, how clients perceive it themselves. At that point the services supplier can control these evaluations and shift it on desirable direction. Irrespective of clients’ opinion in point of quality, could be initiated deceptive actions while expended money and time would be meaningless investment. Services appeared in the center of economical brief: it’s become compulsory implement on purpose to satisfy the main desires and needs also to increase public welfare (Kindurys, 1998), however services provided by LAPE swimming pool will not be analyzed in economical aspect. Services organization, which provides qualitative services, gains the acceptance and loyalty of consumers, increases market share, forms and maintains competent personnel and becomes less exposed concerning the strife of prices... [to full text]
689

Migratory behaviour of Baltic salmon (Salmo salar L.) : adaptive significance of annual cycles

Eriksson, Torleif January 1988 (has links)
This thesis evaluates the adaptive significance of annual cycles on the migratory behaviour of Baltic salmon (Salmo salar L.). The studies have included field experiments as well as laboratory studies gf maturity and migratory behaviour patterns of smolts and postsmolts mainly from the Angerman river population. Contrasting to the phenotypical elasticity in life-history traits, Baltic salmon was found to have a rather strict temporal organization of their annual behavioural patterns. Two year old smolted Baltic salmon showed drastic differences in migratory behaviour when compared in tanks containing either fresh or brackish water. Freshwater kept fish showed an annual cycle where downstream displacement in the upper water column was followed by a stationary behaviour, indicating a readaption to a freshwater life. Fish in brackish water behaved as a migratory fish throughout tne study. Baltic salmon also showed differences in maturation patterns in fresh and brackish water. Three summer old males detained in freshwater all matured sexually the following autumn. If transferred to sea and kept in net- pens a low proportion matured, mainly previously matured males. Furthermore there was a size- dependent relationship of sexual rematuration. Many small previously matured males did not migrate, similarly small previolusly matured males were unable to respond to shifts in the environment. With larger size the alternatives of sexual maturation and high growth rate wi more related to the environmental conditions the fish experienced. A hypothesis has been tested assuming that Baltic salmon migration is influenced by an annual time program. According to the hypothesis the migratory distance covered in the Baltic should be a result of a migratory activity sequence rather than a definite goal orientation. Fish detained before release generally showed a shorter distance between release point and area of recapture compared to fish released at normal time of smoltrun. The migratory distance appeared to be inversly related to the period of delay before release. A seasonal difference in migratory propensity was recorded. An instantaneous mortality curve for Baltic salmon during seaward migration and early sea-phase was estimated based on recapture data on sequentially related fish. The weekly mortality rate decreased from an initial mean of 271 during onset of migration, to 3.51 in mean during autumn. The high risk of mortality during the first part of migration indicated that strong selective forces act on a precise seasonal timing of migration. / <p>Diss. (sammanfattning) Umeå : Umeå universitet, 1988, härtill 5 uppsatser</p> / digitalisering@umu
690

Exposició a subproductes de cloració a les piscines i efectes respiratoris en banyistes

Font Ribera, Laia 29 November 2010 (has links)
ANTECEDENTS: La natació té beneficis per la salut, però l’assistència a piscines comporta l’exposició a subproductes de la cloració (SPC). Els banyistes podrien tenir cert risc de patir efectes respiratoris, com l’asma, però l’evidència és inconsistent. L’objectiu principal és determinar si l’assistència a piscines s’associa a efectes respiratoris aguts i crònics, especialment l’asma infantil. MÈTODES: Per avaluar efectes aguts es mesura funció pulmonar i diferents biomarcadors respiratoris a 48 adults sans abans i després de nedar en una piscina clorada. Per avaluar efectes crònics: estudi transversal a Sabadell (9-12 anys; N=3.223) i estudi longitudinal en una cohort de naixement (ALSPAC, Regne Unit; 7-10 anys; N=5.738). Informació sobre assistència a piscines durant la infància i símptomes d’asma i al lèrgia recollida amb qüestionari i espirometria. RESULTATS: L’únic efecte agut detectat és un lleuger augment de la permeabilitat pulmonar, estimada amb la concentració de CC16 en sang, correlacionat amb l’exposició a SPC i l’exercici físic. L’assistència a piscines no s’associa a un augment del risc d’asma, tampoc entre els nens atòpics, però s’associa a una menor prevalença d’alguns símptomes respiratoris i millor funció pulmonar. Els nens asmàtics que havien anat a la piscina tenen menys símptomes d’asma. CONCLUSIÓ: Es detecta un lleuger efecte agut sobre la permeabilitat de l’epitel li pulmonar dels banyistes, però actualment se’n desconeix la rellevància clínica. Aquest treball no dóna suport a la hipòtesi que l’assistència a piscines durant la infància augmenta el risc d’asma. Al contrari, la natació s’associa lleugerament a menys símptomes d’asma entre els 7 i 12 anys d’edat. / BACKGROUND: Swimming is a healthy activity, but swimming pool attendance enhances the exposure to disinfection by-products (DBP). Swimming pool attendants may have a higher risk of suffering from respiratory conditions, such as asthma, but the evidence is unconsistent. The aim is determine if swimming pool attendance is associated with acute and chronic respiratory effects, especially childhood asthma. METHODS: To evaluate acute effects lung function and several respiratory biomarkers were measured in 48 healthy adults before and alter swimming in a chlorinated pool. To evaluate chronic effects: crosssectional study in Sabadell (9-12 years; N=3,223) and longitudinal study in a birth cohort (ALSPAC, UK; 7- 10 years; N=5,738). Information on swimming pool attendance and asthma and allergic symptoms was collected by questionnaire and spirometry. RESULTS: The only acute effect detected was an slight increase in the lung epithelium permeability, estimated by serum CC16 concentration, correlated with DBP exposure and physical activity. Swimming pool attendance was not associated to an increased asthma risk, neither in atopic children, but was associated with a lower prevalence of some respiratory symptoms and higher lung function. Asthmatic children who attended swimming pools had less asthma symptoms. CONCLUSION: An slight acute effect on the lung epithelium permeability was detected among swimmers, but the clinical relevance is currently not understood. This work do not support the hypothesis that swimming pool attendance during childhood increases the asthma risk. On the contrary, swimming is associated to slightly lower prevalence of asthma symptoms in children 7 to 12 years old.

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