Repetitive work is common in the workplace and can lead to the development of muscle fatigue. The purpose of this thesis was to improve our understanding of muscular and kinematic adaptation strategies of the shoulder complex throughout the process of fatigue and recovery. To achieve this I completed 6 studies, three studies investigating various aspects of repetitive work and fatigue and three methodological studies that were needed to interpret results. The muscular and kinematic effects of repetitive work were first investigated by incorporating a fatigue protocol between pre- and post-fatigue, simulated, repetitive work (Chapter 2). Fatigue is a complex process and how fatigue develops has been shown to influence its effects. To address this, Chapter 6 and 7 respectively, investigated the response to dynamic and static, fatiguing, repetitive work performed until participants reached termination criteria. Electromyography (EMG) was used throughout this thesis to assess muscle activity, which presented challenges because of its time consuming MVE protocols, the effects of myoelectric fatigue on its interpretation and between participants, fatigue developed in different muscles and at different rates, making comparisons between individuals challenging. For more efficient data collection, a method was developed to reduce the number of maximum voluntary exertions (MVE) required to elicit repeatable, maximum shoulder muscle activity, without eliciting muscle fatigue (Chapter 3). Methods were developed (Chapters 4 and 5) to mitigate the effects of myoelectric fatigue on EMG data and to calculate a multi-muscle fatigue score. This improved interpretation of how prolonged repetitive work impacted load sharing in the shoulder muscles and allowed the calculation of a multi-muscle fatigue score. Overall, this thesis found that the response to repetitive work is complex, multi-faceted and varies between individuals. Repetitive work impacts kinematics, muscle activity, muscle fatigue, strength, affective valence and perceived mental and physical fatigue in both static and dynamic work tasks (Chapters 2, 6, 7). Participants utilized the degrees of freedom in the shoulder complex and use coordinated compensation strategies to maintain their task performance, both following muscle fatigue (Chapter 2) and while developing muscle fatigue (Chapter 6, 7). These responses changed over time, as different muscles fatigued and recovered and were variable between individuals (Chapters 2, 6, 7). Removing fatigue artifacts from the EMG showed that muscle activity changes observed are due to load sharing between the musculature of the shoulder complex (Chapter 6, 7). Participants can adapt to the challenge of fatiguing, repetitive work and individuals will use different, coordinated strategies to maintain task performance. / Thesis / Doctor of Philosophy (PhD)

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Made available in DSpace on 2014-06-11T19:30:54Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-04-25Bitstream added on 2014-06-13T19:19:39Z : No. of bitstreams: 1 teixeira_wg_me_botib.pdf: 944579 bytes, checksum: 046ae2a3b20fa26acc2b231873f2a3af (MD5) / Universidade Estadual Paulista (UNESP) / O genoma dos organismos eucariotos apresenta-se organizado em seqüências simples e repetidas. As seqüências repetidas de DNA estão presentes em centenas a milhares de cópias dispersas ou agrupadas no genoma e localizam-se preferencialmente em regiões heterocromáticas, desempenhando papel relevante na organização do genoma desses organismos. Nesse sentido, a realização de estudos genéticos básicos sobre a organização genômica dessas seqüências repetidas é fundamental para uma melhor compreensão do seu papel biológico assim como o entendimento de sua dinâmica evolutiva entre os diversos grupos de vertebrados. Os Cichlidae constituem uma das mais especiosas famílias de peixes, com cerca de 3.000 espécies distribuídas pela América Central e do Sul, África, e sudeste da Índia. Este grupo passou por um rápido e extenso processo de radiação adaptativa ao longo dos tempos, constituindo-se em importantes entidades biológicas para a realização de estudos evolutivos. Dentre os Cichlidae, as espécies do gênero Cichla (tucunarés), com distribuição exclusiva na América do Sul, apresentam grande importância ecológica e econômica. No entanto, estudos genéticos envolvendo espécies desse gênero são ainda escassos. Assim, o presente trabalho teve por objetivo isolar e caracterizar seqüências repetidas de DNA no genoma de Cichla kelberi. Elementos repetidos de DNA foram isolados por PCR (elementos Rex1, Rex3, Rex6 e Tc1) e digestão enzimática (elemento Tuc), seqüenciados e mapeados cromossomicamente por FISH para o estudo de seu padrão de distribuição no genoma. O elemento Tuc apresentou elevada similaridade com seqüências do gene da transcriptase reversa de Oryzias melastigma, o que sugere tratar-se de um elemento retrotransponível. Análises comparativas do elemento Tuc a bancos de sequência mostraram alta similaridade... / The genome of eucaryote organisms is organized into single and repetitive sequences. The repetitive DNA sequences are represented by hundreds to thousands of dispersed or tandem-arrayed copies preferentially localized on the heterochromatic regions, having important function on the genome organization of the organisms. Therefore, the development of basic genetic studies about the genome organization of these repetitive sequences are fundamental to a better comprehension of their biologic role and the understanding of their evolutionary dinamics. The Cichlidae are one of the most diverse fish families, having about 3.000 species distributed around Central and South America, Africa and Southeast India. This group underwent a large and rapid process of adaptative radiation, becoming an important biological model. Among the Cichlidae, the species of the genera Cichla (tucunarés), with exclusive distribution in South America, have a significative economic and ecologic importance. However genetic studies on species of this genera are scarce. Therefore, this work had the aim to isolate and characterize repetitive DNA sequences of the genome of Cichla kelberi. Repetitive DNA sequences were isolated using PCR (elements Rex1, Rex3, Rex6 and Tc1) and restriction digestion (element Tuc), sequenced and their genome distribution determined by FISH. The Tuc element showed high similarity to sequences of reverse transcriptase gene of the fish Oryzias melastigma, which suggests that such element correspond to an retrotransposon element. Comparative analysis of the Tuc element to DNA sequence data bank showed high similarity with repetitive sequences in the genome of several vertebrates, including fishes, amphibians and mammals. Results of FISH showed an accumulation of obtained elements preferentially in centromeres of all chromosomes of the complement, and few telomeric blocks in some... (Complete abstract click electronic access below)

O DNA repetitivo constitui uma fração considerável do genoma de muitos organismos eucarióticos. Composto tanto por sequências funcionais, como os genes ribossômicos, quanto não codificantes, como é o caso dos elementos transponíveis, mini/microssatélites e o DNA satélite, essa porção do genoma tem sido amplamente utilizada como objeto de estudo, uma vez que sequências repetitivas podem estar associadas, por exemplo, a processos de diferenciação sexual. Esses estudos têm auxiliado tanto na melhor compreensão da dinâmica dessas regiões cromossômicas, como salientado a importância, a conservação e a evolução da porção repetitiva no genoma. O gênero Eigenmannia (Gymnotiformes, Sternopygidae) compreende espécies crípticas do ponto de vista morfológico que exibem variação no número cromossômico e podem apresentar sistemas sexuais XY ou ZW nos quais os elementos do par sexual diferem pela presença de blocos heterocromáticos maiores do que os encontrados em cromossomos autossomos, ou sistemas múltiplos envolvendo translocação Y-autossomo. O presente trabalho tem por objetivos o estudo sobre do gene Citocromo Oxidase I (COI), de forma a verificar a capacidade discriminatória desse gene mitocondrial e sugerir possíveis espécies dos então cariomorfos do gênero Eigenmannia no estado de São Paulo, continuidade do estudo do DNA repetitivo no gênero Eigenmannia, tanto de regiões funcionais do genoma, no caso o gene ribossômico 5S, bem como de elementos transponíveis, permitindo assim uma melhor compreensão sobre a distribuição, conservação nos cariomorfos e verificar sua eventual participação no processo de diferenciação não só de cromossomos sexuais, mas também na evolução cariotípica do grupo. Os resultados obtidos com o gene COI, assim como aqueles obtidos pelo gene ribossômico 5S evidenciam distâncias genéticas consistentes com a hipótese de que os cinco cariomorfos possam ser considerados como espécies distintas. Além disso, a hibridação in situ do gene ribossômico 5S forneceu uma nova evidência para a fusão cromossômica que deu origem ao cromossomo sexual Y, já descrita na literatura, enquanto que a hibridação de sequências teloméricas não forneceu evidências de processos de fusão recentes envolvendo os cariomorfos. Com relação aos elementos transponíveis foi possível verificar padrões distintos nos elementos TC1 e Rex1 no que diz respeito às sequências, uma vez que o elemento TC1 delimitou dois grandes grupos o que pode indicar uma invasão simultânea nos grupos e no retrotransposon Rex1 a invasão tenha ocorrido em um ancestral comum a todos os cariomorfos / The repetitive DNA constitutes a considerable fraction of the genome of many eukaryotic organisms. Compound by both functional sequences, such as ribosomal genes, and non-coding, such as transposable elements, mini / microsatellite DNA and the satellite, this portion of the genome has been widely used as a study object, since the repetitive sequences may be associated with, for example, the processes of sexual differentiation. These studies helped to understand the dynamics of these chromosomal regions, pointing the importance, conservation and evolution of the repetitive portion of the genome. The genus Eigenmannia (Gymnotiformes, Sternopygidae) comprises a morphological cryptic species that exhibit variation in chromosome number and may have sexual XY or ZW systems in which the elements of sexual pair differ by the presence of heterochromatic blocks larger than those found in chromosomes autosomes, or systems involving multiple Y-autosome translocation. The present work aims to study the gene Cytochrome Oxidase I (COI) to verify the discriminatory capacity of this mitochondrial gene and suggest possible species of the so called karyomorphs of the genus Eigenmannia in the state of São Paulo. The study of repetitive DNA in Eigenmannia genus, includes 5S ribosomal gene and transposable elements, thus allowing a better understanding of the distribution, conservation in karyomorphs and verify their possible participation in the process of differentiation not only of sex chromosomes, karyotypic evolution but also in the group. The results obtained with the COI gene, as well as those obtained by the 5S ribosomal gene demonstrate genetic distances consistent with the hypothesis that the five karyomorphs can be regarded as separate species. In addition, in situ hybridization of ribosomal 5S gene provided new evidence for chromosomal fusion which led to the Y sex chromosome, as described in the literature, whereas hybridization of telomeric sequences did not provide evidence of recent fusion events involving the karyomorphs. Regarding transposable elements, it could be verified distinct sequence patterns between TC1 and Rex1 elements, since the TC1 element delimited two groups which may indicate a simultaneously invasion in those groups and retrotransposon Rex1 invasion has occurred in a common ancestor to all karyomorphs

Repetitive Model Predictive Control (RMPC) incorporates the idea of Repetitive Control (RC) into Model Predictive Control (MPC) to take full advantage of the constraint handling, multivariable control features of MPC in periodic processes. The RMPC achieves perfect asymptotic tracking/rejection in periodic processes, provided that the period length used in the control formulation matches the actual period of the reference/disturbance exactly. Even a small mismatch between the actual period of process and the controller period can deteriorate the RMPC performance significantly. The period mismatch occurs either from an inaccurate estimation of actual frequency of disturbance due to resolution limit or from trying to force the controller period to be an integer multiple of sampling time. An extension of RMPC called Robust Repetitive Model Predictive Control (R-RMPC) is proposed for such cases where period length cannot be predetermined accurately, or where period is not an integer multiple of sampling time. This robust RMPC borrows the idea of using weighted, multiple memory loops in RC for robustness enhancement. The modified RMPC is more robust in the sense that small changes in period length do not diminish the tracking/rejection properties by much. Simulation results show that R-RMPC achieves significant improvement over the standard RMPC in case of a slight period mismatch. The effectiveness of this Robust RMPC is demonstrated by applying it to a mechanical motion tracking machine whose function is to follow a constant trajectory while rejecting periodic disturbances of an uncertain period.

名古屋大学博士学位論文 学位の種類:博士（医療技術学）（課程）学位授与年月日:平成21年3月25日

Up to 85% of cyclists experience repetitive strain injuries (RSI's). During long bouts of repetitive tasks, muscle fatigue may cause mal-alignments in kinematics, having cumulative effects, leading to an RSI. Purpose: The study's purpose was to examine how changes in localized muscle fatigue relate to changes in movement kinematics in highly trained cyclists throughout a full fatigue protocol. Methods: Seven highly trained cyclists participated in a 2 session experiment. Session 1 included a VO2 max test and familiarization trial and Session 2 was the fatigue protocol. Kinematic angles measured were trunk lean, hip, knee, ankle, and knee splay angle. Mean angle (MA) and range of motion (ROM) was calculated for each revolution thought the trial. Muscles monitored were the quadriceps, hamstring, gastrocnemius, and tibialis anterior. EMG median frequency (MDF) for each muscle was calculated for each revolution by averaging MDF for the two halves of each revolution. Cross-correlation analysis was done on MDF and MA data and MDF and ROM data. Results: All subjects exhibited increases in trunk lean and decreases in ankle angle. Non-monotonic changes were observed in trunk lean, ankle, knee splay angle, and among ROM results for all 5 angles. A 1-tailed T-tests for all subjects, revealed that HAM (p = 0.020) and GAS (p = 0.018) exhibited significant muscle fatigue. One-tailed T-tests yielded significantly negative cross-correlation time lags [Greek small letter tau] for trunk lean MA, ROM, and hip MA. Conclusions: Non-monotonic changes are present in kinematics and MDF. Therefore pre vs. post experimental designs cannot quantify fatigue processes. Shifts in trunk lean MA, ROM and hip MA are significantly correlated with preceding decreasing shifts of MDF (indicative of onset of fatigue). / text

Thesis--PlanB (M.S.)--University of Wisconsin--Stout, 1998. / Field project. Includes bibliographical references.

Attentional bias is commonly associated with emotional disorders. However, potential transdiagnostic mediators of attentional bias, such as repetitive negative thinking (RNT) have been overlooked. The current study examined attentional biases associated with three forms of RNT and tested a proposed mediation model. Participants (N = 249) completed self-report measures, a repetitive thought induction, and an emotional face dot-probe measure of attentional bias. I hypothesized that RNT would be associated with attentional bias to angry, sad, and disgust faces, worry with angry faces, and rumination with sad faces after a negative thought induction. I also hypothesized that attentional bias scores would mediate the association between negative affect and RNT. Overall study hypotheses were not supported. Clinical worry was associated with slower reaction times to sad faces in the negative induction. RNT, worry, and rumination were not associated with attentional bias scores to emotional faces, and the mediation model was not supported.

Made available in DSpace on 2014-06-11T19:32:14Z (GMT). No. of bitstreams: 0 Previous issue date: 2008-07-31Bitstream added on 2014-06-13T19:42:40Z : No. of bitstreams: 1 mazzuchelli_j_me_botib.pdf: 482271 bytes, checksum: 71e03833a737efe8fe5266606a8471fc (MD5) / Conselho Nacional de Desenvolvimento Científico e Tecnológico (CNPq) / Universidade Estadual Paulista (UNESP) / Uma grande porção do genoma da maioria dos organismos é composta por seqüências repetidas de DNA que foram considerados, por muitos anos, como DNA “egoísta” ou como DNA “lixo”. Pouca atenção tem sido dada a estes segmentos de DNA uma vez que eles não são transcritos em produtos codificantes ou funcionais. Atualmente diversos trabalhos têm sugerido o envolvimento destas seqüências na regulação e reparo de alguns genes, na diferenciação de cromossomos sexuais e na organização estrutural e funcional do genoma. Os estudos citogenético-moleculares, como o mapeamento físico cromossômico, têm demonstrado que as seqüências de DNA repetidas podem ser muito úteis como ferramentas para definir a estrutura e revelar a organização e evolução do genoma das espécies. No presente trabalho, vários elementos repetidos (AoHinfI-4, AoHaeIII-6, AoHaeIII-15) foram isolados, através de restrição enzimática, do genoma do ciclídeo sul-americano Astronotus ocellatus, popularmente conhecido como “Oscar” ou “Apaiari”. Estes elementos foram seqüenciados e utilizados como sondas para hibridação cromossômica para o estudo de seu padrão de distribuição no cariótipo. As seqüências dos elementos repetidos isolados por restrição enzimática apresentaram alta similaridade com outros DNAs repetidos de outras espécies de peixes já depositadas em banco de dados. Os resultados da hibridação in situ de todos os elementos utilizados mostraram um acúmulo de marcações preferencialmente centromérica em todos os cromossomos do complemento. Essas marcações também são coincidentes com a localização da heterocromatina evidenciada através do bandamento C, reforçando a idéia do acúmulo de DNA repetitivo em regiões heterocromáticas. Essa distribuição preferencialmente centromérica dos elementos repetidos isolados sugere que tais seqüências devam desempenhar... / In most organisms a great portion of the genome is composed of repetitive DNA sequences. However little attention has been given to these segments of DNA, which were considered by many years as selfish or “junk” DNA. On the other hand, several works have suggested the involvement of these sequences in the regulation and repair of some genes, in the differentiation of sex chromosomes and in the structural and functional organization of the genome. The cytogenetics and molecular studies, as the physical chromosome mapping, has been demonstrating that repetitive sequences can be very useful as tools to define the structure and to reveal the organization and evolution of the genome of the species. In the present work several repetitive elements (retrotransposons Rex1, Rex3 and Rex6; transposon Tc1; the elements AoHinfI-4, AoHaeIII-6, AoHaeIII-15) were isolated using PCR and enzymatic restriction digestion of the genome of the cichlid Astronotus ocellatus, popularly known as Oscar or Apaiari. These elements were sequenced and their genomic distribution determined by chromosomal in situ hybridization. The nucleotide sequences of the isolated elements showed high similarity to repetitive DNAs of other fish species available in public databases. The results of in situ hybridization showed an accumulation of all obtained elements preferentially in centromeres of all chromosomes of the complement. The chromosomal signals were also coincident with the location of the heterocromatins evidenced through the C banding, reinforcing the idea of the accumulation of repetitive DNA in heterocromatic areas. These preferential distribution in the centromeres, suggests that such sequences should play an important role in the functional organizational and structure of the centromeres and, thus in the genome of this species. The great majority of the studies using the physical chromosome mapping... (Complete abstract click electronic access below)