Submitted by Luciana Ferreira (lucgeral@gmail.com) on 2015-01-27T13:40:32Z No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação - Paulo Henrique Ramos Guimarães - 2014.pdf: 1517515 bytes, checksum: 862883b307a6231b2a7f63d38c9f03ea (MD5) / Approved for entry into archive by Luciana Ferreira (lucgeral@gmail.com) on 2015-01-28T11:19:18Z (GMT) No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação - Paulo Henrique Ramos Guimarães - 2014.pdf: 1517515 bytes, checksum: 862883b307a6231b2a7f63d38c9f03ea (MD5) / Made available in DSpace on 2015-01-28T11:19:18Z (GMT). No. of bitstreams: 2 license_rdf: 23148 bytes, checksum: 9da0b6dfac957114c6a7714714b86306 (MD5) Dissertação - Paulo Henrique Ramos Guimarães - 2014.pdf: 1517515 bytes, checksum: 862883b307a6231b2a7f63d38c9f03ea (MD5) Previous issue date: 2014-02-28 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior - CAPES / Some spatial analysis methods have been applied in order to mitigate environmental variation. The objective of this study was to evaluate the efficiency of spatial statistical, through the method of Papadakis, relative to the analysis to augmented blocks Federer in the correction of environmental variation. Were evaluated 198 progenies S0:2 of rice and four witnesses for augmented blocks of Federer. Data set were taken in the grain yield (GY, kg ha- 1) and plant height (PH, cm). The data set were subjected to variance analyses and were estimated the genetic and phenotypic parameters. The different approaches (BAF and Papadakis) were compared as to their estimates of genetic and phenotypic parameters. The ranking of adjusted means in the two models analyzed was performed, and calculated the Spearman correlation. There have been improvements in the statistics that depict the experimental accuracy when the spatial analysis was, that affect the estimates of genetic and phenotypic parameters. The use of the Papadakis method yielded fewer iterations compared to BAF for the same value of . Was able to gain direct selection for the AP and PG characters when the Papadakis method was used. With the use of spatial analysis selection was less influenced by the effect of environmental variation. Finally it was found that the spatial analysis methods were effective in the removal of environmental effects highlighting the Papadakis method, indicating that it can provide improvement / Alguns métodos de análise espacial têm sido aplicados objetivando reduzir a variação ambiental. O objetivo deste trabalho foi avaliar a eficiência da análise espacial, por meio do método de Papadakis, em relação ao delineamento de blocos aumentados de Federer na correção da variação ambiental. Foram avaliadas 198 progênies S0:2 de arroz irrigado e quatro testemunhas no delineamento de blocos aumentados de Federer. Os caracteres avaliados foram: produção de grãos (PG, kg ha-1) e de altura de plantas (AP, cm). Foi efetuada análise de variância para os caracteres estudados e estimados os componentes de variância e os parâmetros genéticos e fenotípicos. As diferentes abordagens (BAF e Papadakis) foram comparadas quanto às suas estimativas de parâmetros genéticos e fenotípicos e correlação de Spearman. Houve melhorias nas estatísticas que retratam a precisão experimental quando a análise espacial foi utilizada, isto influenciou as estimativas de parâmetros genéticos e fenótipos. O uso do método de Papadakis apresentou a necessidade de uso de menor número de repetições em relação ao BAF para o mesmo valor de . Houve ganho de seleção direto para os caracteres AP e PG quando o método de Papadakis foi utilizado. Com o uso da análise espacial a seleção foi menos influenciada pelo efeito da variação ambiental. Por fim verificou-se que o método de Papadakis foi eficiente na remoção dos efeitos ambientais, indicando que o mesmo pode proporcionar melhoria na precisão experimental, o que torna o processo seletivo mais eficiente.

Made available in DSpace on 2015-04-11T13:55:49Z (GMT). No. of bitstreams: 1 Catiele Vieira Borges.pdf: 1231779 bytes, checksum: d72dab79964f3c9da27e72040b426932 (MD5) Previous issue date: 2012-02-15 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / The jatropha (Jatropha curcas L., Euphorbiaceae), is a perennial cycle plant whose attentions in the last six years has directed its capacity for vegetable oil. Given their biological attributes, agronomic, economic and industrial, the species is one of oleaginous on the agenda of government interest, which through the National Program for Production and Use of Biodiesel has intensified the search for new bioenergy sources. However, this is still oleaginous phase of domestication and quest for technological mastery. Meet the productive potential, the relationship between characters, the genetic variability and infer genetic parameters have directed in recent years, most quantitative genetic studies and breeding in Brazil. Therefore, the aim of the present study was to estimate genetic parameters and predict random variables important to the strategies of selection and breeding; meet the minimum harvest / measurements needed to choose jatropha trees; estimate genotypic and phenotypic correlations; evaluate the progress of genetic grain production and to study the genetic variability. Was evaluated for 24 months at the experimental farm of Embrapa, in Porto Velho - RO, an experiment with three full blocks, four provenances (two of Rondônia, one of Minas Gerais and São Paulo) with 16 trees per plot, spaced 2x3 meters. The traits associated with grain yield and plant architecture. The great genetic evaluation procedure REML/BLUP was used for the prediction of random variables, genetic parameter estimation and inference about repeatability. Inferences about variance components and estimates of genetic parameters for some agronomic traits during the first two years of development of Jatropha curcas, showed genetic variability exists. The numbers of fruits per bunch and maturation index showed little characters are informative and useful in quantitative genetic studies. The stabilization genotypic characters for number of clusters at harvest of half a year, number of branches, height, crown projection in greater spacing and canopy volume was obtained with equal or less than three measurements per year. Already for grain yield and number of clusters at harvest year end, required a greater number of measurements (mi > 4). High correlations (r.) were obtained genotypic and phenotypic characters among themselves for grain yield, its components and those characters associated with plant architecture (r.  0.75). Predicted genetic gains for grain production of the first two years of planting were respectively higher than 20%, considering the selection of the ten best individuals. When considering the two growing seasons for variable grain production, most plants exhibited average performance (adaptability) generally indicated as the centroid method. Considering the information of the individual additive effects, genetic diversity was not necessarily linked to geographical origin, as plants of different provenances formed groups. At the level of individuals, formed several genetically divergent groups. / O pinhão-manso (Jatropha curcas L., Euphorbiaceae), é uma planta de ciclo perene cujas atenções nos últimos seis anos tem se dirigido a sua capacidade para produção de óleo vegetal. Dado a seus atributos biológicos, agronômicos, econômicos e industriais, a espécie é uma das oleaginosas em pauta de interesse do governo, que por meio do Programa Nacional de Produção e Uso do Biodiesel tem intensificado a busca por novas fontes bioenergéticas. Contudo, essa oleaginosa ainda encontra-se em fase de domesticação e busca por domínio tecnológico. Conhecer o potencial produtivo, a relação entre caracteres, a variabilidade genética e inferir sobre parâmetros genéticos têm direcionado, nos anos recentes, a maioria dos estudos genéticos quantitativos e de melhoramento no Brasil. Portanto, objetivou-se no presente estudo estimar parâmetros genéticos e predizer variáveis aleatórias importantes às estratégias de seleção e melhoramento; conhecer o período mínimo de colheita/mensurações necessário para selecionar árvores de pinhão-manso; estimar correlações genotípicas e fenotípicas; avaliar o progresso genético da produção de grãos e estudar a variabilidade genética. Foi avaliado durante 24 meses na fazenda experimental da Embrapa, em Porto Velho RO, um experimento com três blocos completos, quatro procedências (duas de Rondônia, uma de Minas Gerais e uma de São Paulo) com 16 árvores úteis por parcela, espaçadas 2x3 metros. Foram avaliados os caracteres associados à produção de grãos e de arquitetura da planta. O procedimento ótimo de avaliação genética REML/BLUP foi usado para a predição de variáveis aleatórias, estimação de parâmetros genéticos e inferência sobre a repetibilidade. As inferências sobre os componentes de variância e as estimativas de parâmetros genéticos para alguns caracteres agronômicos, durante os dois primeiros anos de desenvolvimento do pinhão-manso, mostraram existir variabilidade genética. Os números de frutos por cacho e índice de maturação mostraram serem caracteres pouco informativos e úteis nos estudos genéticos quantitativos. A estabilização genotípica para os caracteres número de cachos, na colheita do meio ano, número de ramos, altura, projeção da copa no maior espaçamento e volume de copa, foi obtida com número igual ou inferior a três medições anuais. Já para a produção de grãos e número de cachos, na colheita do final do ano, exigiu-se maior número de mensurações (mi > 4). Elevadas correlações (r.) genotípicas e fenotípicas foram obtidas entre si para os caracteres de produção de grãos, seus componentes e aqueles caracteres associados à arquitetura da planta (r.  0,75). Ganhos genéticos preditos para a produção de grãos dos dois primeiros anos de plantio foram respectivamente superiores a 20%, considerando a seleção dos dez melhores indivíduos. Ao se considerar os dois anos agrícolas para a variável produção de grãos, a maioria das plantas exibiram médio desempenho (adaptabilidade) geral, conforme indicou o método do centroide. Ao se considerar as informações dos efeitos aditivos individuais, a diversidade genética não esteve necessariamente associada à origem geográfica, pois plantas de diferentes procedências formaram grupos. Em nível de indivíduos, formaram-se vários grupos divergentes geneticamente.

Stiffness analysis of an arm of an industrial robot with linear kinematics during a drilling operation. For solving this problem are used optical scanners. Finding the optimal cutting force for drilling by criterions: minimal deformation of robots arms and, at the same time, the emerging vibration from the cutting process is also minimal.

Theme of the Master’s thesis is analysis of process for production of small plates. Main parts of the thesis are analysis of the production process, process mapping, data capture, analysis of the data by Pareto analysis and find causes of nonconformities. Causes analysis is based on data analysis and process observation. It is divided to chapters by factors which are influencing the process. Optimization measures are designed with regard to their simplicity of realization and system in organization.

Aim of the thesis is suggestion of Measurement system analysis for a company in the automotive industry. There were made an analysis of requirement of ČSN EN ISO 9001 and ČSN P ISO/TS 16949. Next there are procedures for various measurement system analysis. There are camparison between company and standart’s requirements. Then there are choosen suitable method for measurement system analysis.

No description available.

ABSTRACT Fabrication and Characterization of Torsional Micro-Hinge Structures Mike Marrujo There are many electronic devices that operate on the micrometer-scale such as Digital Micro-Mirror Devices (DMD). Micro actuators are a common type of DMD that employ a diaphragm supported by torsional hinges, which deform during actuation and are critical for the devices to have high stability and reliability. The stress developed within the hinge during actuation controls how the actuator will respond to the actuating force. Electrostatically driven micro actuators observe to have a fully recoverable non-linear viscoelastic response. The device consists of a micro-hinge which is suspended by two hinges that sits inside a micro machined well. To achieve a specific angle of rotation when actuated, the mechanical forces need to be characterized with a range of different forces applied to the edge of the micro-hinge. This research investigates the mechanical properties and the amount of force needed to rotate to specific angles by comparing theoretical performance to experimentally measured values. Characterizing the mechanical forces on the micro-hinge will further the understanding of how the device operates under a specific applied force. The material response to the amount of stress within the hinges will control the amount of actuation that is achieved by that force. The test devices were fabricated using common semiconductor fabrication techniques. The micro-hinge device was created on a 500µm, double-sided polished, single crystal (100) silicon wafer. In order to create this device, both wet etching and dry etching techniques were employed to produce an 8µm thick plate structure. The bulk etching of 480µm was achieved by wet etching down into the silicon (Si) to create the wells. Dry etching was used for its high precision to release the micro-hinge structure. Once fabricated, the micro-hinge actuators were tested using a Technics turntable arm with a built in micrometer that applied a constant force while measuring the displacement of the actuator. The rotation of the hinge was measured by reflecting a Helium-Neon (HeNe) laser beam off a mirror, which is attached to the pivot of the arm that’s applying the force, and any type of displacement was recorded with a Photo Sensitive Device (PSD). The test stand applied a small force which replicated the amount of electrostatic forces needed to achieve a specific degree of rotation. Results indicate that the micro-hinge achieved a repeatable amount of rotation when forces were applied to it. The micro-hinge would endure deformation when too much force would be applied and yield a maximum amount of force allowed.

Made available in DSpace on 2016-04-27T18:12:12Z (GMT). No. of bitstreams: 1 Denise Torreao Correa da Silva.pdf: 13435475 bytes, checksum: 0ee13ef29957b217cb6d5b50c30944cf (MD5) Previous issue date: 2016-02-16 / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior / To estimate the measurement uncertainty of the pure-tone audiometry by air-conduction, in the frequencies from 250 Hz to 8000 Hz, and bone-conduction, at frequencies of 500 Hz to 4000 Hz. Method: This is an observational, descriptive and cross sectional study. Accuracy measurement tests under repeatability conditions were conducted (same measurement procedure, operator, measuring system, operating conditions and site, in a short time interval). Each of the nine participants took part in two trials with five repetitions each through air and bone conduction, in the right and left ear. In Trial 1 the interval between each repetition was five minutes. In Trial 2 the interval between repetitions was sixty minutes. To calculate the combined uncertainty the type A uncertainty, derived from repeatability, and Type B uncertainty derived from the audiometer calibration certificate, the audiometer resolution, and the conditions of the test environment were considered. Results: There was no statistically significant difference intra-individuals in different time intervals (p> 0,05), in both air and bone conduction. The median of type A uncertainty ranged from 0 dB to 2,7 dB in the right ear, and 0 dB to 3,5 dB in the left ear for air conduction. In bone conduction the median of type A uncertainty ranged from 2.2 dB to 2.7 dB in both ears. Type B uncertainties, for air and bone conduction, derived from the contribution of the equipment used for the test (0,4 dB), of the equipment resolution (1,4 dB), and the test environment (5,0 dB). Considering the median of type A uncertainty derived from accuracy measurement, and type B uncertainties mentioned above, the estimated of measurement uncertainty of pure tone audiometry, air and bone conduction, in this study, for the confidence level of 95% (k=1.96) and 95.45% (k=2.0) were 10 dB or 11 dB, for the frequencies tested, in both Trials 1 and Trial 2, in both ears. Conclusions: This study demonstrates the feasibility of accuracy measurement tests under repeatability conditions, as proposed in this work. In this study the contribution of type B uncertainties, derived from the audiometer calibration certificate, potentiometer and test environment, this latter being more prevalent, was higher than that of type A uncertainty derived from repeatability, indicating the need to keep control of these variables. The expression of measurement uncertainty can increase even more the sensitivity and specificity of audiometry, respectively increasing the rate of true positives and true negatives, since it is considered the gold standard. In this study the expanded uncertainty, for the confidence level of 95% and 95,45% ranged between 10 and 11 dB, in air and bone conduction. The reliability of the pure-tone audiometry test depends on the expression of its uncertainty; only so results obtained with the same subject in different places and times can be compared. Therefore the expression of uncertainty should be taken into consideration when delivering results and in preparing reports, for subsidizing decisions on hearing aids prescription, selection and adaptation procedures, as well as assessment of social security benefit payments, labor actions and health surveillance actions / Estimar a Incerteza de Medição no exame de audiometria tonal por via aérea, nas frequências de 250 Hz a 8 000 Hz, e por via óssea, nas frequências de 500 Hz a 4 000 Hz. Método: Nesta pesquisa, de natureza observacional, descritiva e transversal, foram realizados ensaios de precisão de medição sob condições de repetibilidade (mesmo procedimento de medição, operador, sistema de medição, condições de operação e mesmo local, em curto intervalo de tempo). Cada um dos nove participantes realizou dois ensaios, com cinco repetições de audiometria cada, por vias aérea e óssea, orelhas direita e esquerda. No Ensaio 1 o intervalo entre cada repetição foi de cinco minutos. No Ensaio 2 o intervalo entre as repetições foi de sessenta minutos. Para cálculo da incerteza padrão combinada considerou-se a incerteza do tipo A, derivada da repetibilidade, e as incertezas do tipo B, derivadas do certificado de calibração do audiômetro, da resolução do audiômetro, e das condições do ambiente de teste. Resultados: Para as vias aérea e óssea não houve diferença estatisticamente significante intraindivíduos nos diferentes intervalos de tempo (p > 0,05). A mediana da incerteza do tipo A variou de 0 dB a 2,7 dB, na orelha direita, e de 0 dB a 3,5 dB na orelha esquerda, para a via aérea. Na via óssea a mediana da incerteza do tipo A variou de 2,2 dB a 2,7 dB, em ambas as orelhas. As incertezas do tipo B, tanto para via aérea quanto para a via óssea, foram derivadas da contribuição do equipamento utilizado para o exame (0,4 dB), da resolução do equipamento (1,4 dB), e do ambiente de teste (5,0 dB). Levando-se em consideração a mediana das incertezas do tipo A e as incertezas do tipo B citadas acima, a estimativa da incerteza de medição da audiometria tonal por vias aérea e óssea, neste estudo, para os níveis da confiança de 95% (k=1,96) e 95,45% (k=2,0), foi de 10 dB ou 11 dB, nas frequências testadas, tanto no Ensaio 1 quanto no Ensaio 2, em ambas as orelhas. Conclusões: Este estudo demonstra a viabilidade de ensaios de precisão de medição sob condições de repetibilidade, conforme proposto neste trabalho. Neste estudo a contribuição das incertezas do tipo B, derivadas do certificado de calibração do audiômetro, do potenciômetro e do ambiente de teste, preponderando esta última, foi maior do que a incerteza do tipo A, derivada da repetibilidade, indicando a necessidade de manter-se controle sobre estas variáveis. A expressão da incerteza de medição da audiometria pode elevar, ainda mais, a sensibilidade, e a especificidade da audiometria, respectivamente aumentando a taxa de verdadeiros positivos e de verdadeiros negativos, uma vez que é considerada padrão ouro. Neste estudo a incerteza de medição expandida, para os níveis da confiança de 95% e 95,45% variou entre 10 dB e 11 dB, tanto para via aérea quanto para via óssea. A confiabilidade do exame de Audiometria Tonal, ou Audiometria de Tons Puros depende da expressão de sua incerteza; somente assim resultados obtidos com o mesmo sujeito, em locais e épocas diferentes, podem ser comparados. Portanto a expressão da incerteza deve ser levada em consideração quando da entrega de resultados e confecção de relatórios, seja para decisão sobre procedimentos de indicação, seleção e adaptação de aparelhos de amplificação sonora individual, assim como para avaliação de concessão de benefícios previdenciários, ações trabalhistas e ações de vigilância em saúde

Parkinson's disease (PD) is a progressive, degenerative, neurological disease. The progressive disability associated with PD results in substantial burdens for those with the condition, their families and society in terms of increased health resource use, earnings loss of affected individuals and family caregivers, poorer quality of life, caregiver burden, disrupted family relationships, decreased social and leisure activities, and deteriorating emotional well-being. Currently, no cure is available and the efficacy of available treatments, such as medication and surgical interventions, decreases with longer duration of the disease. Whilst the cause of PD is unknown, genetic and environmental factors are believed to contribute to its aetiology. Descriptive and analytical epidemiological studies have been conducted in a number of countries in an effort to elucidate the cause, or causes, of PD. Rural residency, farming, well water consumption, pesticide exposure, metals and solvents have been implicated as potential risk factors for PD in some previous epidemiological studies. However, there is substantial disagreement between the results of existing studies. Therefore, the role of environmental exposures in the aetiology of PD remains unclear. The main component of this thesis consists of a case-control study that assessed the contribution of environmental exposures to the risk of developing PD. An existing, previously unanalysed, dataset from a local case-control study was analysed to inform the design of the new case-control study. The analysis results suggested that regular exposure to pesticides and head injury were important risk factors for PD. However, due to the substantial limitations of this existing study, further confirmation of these results was desirable with a more robustly designed epidemiological study. A new exposure measurement instrument (a structured interviewer-delivered questionnaire) was developed for the new case-control study to obtain data on demographic, lifestyle, environmental and medical factors. Prior to its use in the case-control study, the questionnaire was assessed for test-retest repeatability in a series of 32 PD cases and 29 healthy sex-, age- and residential suburb-matched electoral roll controls. High repeatability was demonstrated for lifestyle exposures, such as smoking and coffee/tea consumption (kappas 0.70-1.00). The majority of environmental exposures, including use of pesticides, solvents and exposure to metal dusts and fumes, also showed high repeatability (kappas &gt0.78). A consecutive series of 163 PD case participants was recruited from a neurology clinic in Brisbane. One hundred and fifty-one (151) control participants were randomly selected from the Australian Commonwealth Electoral Roll and individually matched to the PD cases on age (± 2 years), sex and current residential suburb. Participants ranged in age from 40-89 years (mean age 67 years). Exposure data were collected in face-to-face interviews. Odds ratios and 95% confidence intervals were calculated using conditional logistic regression for matched sets in SAS version 9.1. Consistent with previous studies, ever having been a regular smoker or coffee drinker was inversely associated with PD with dose-response relationships evident for packyears smoked and number of cups of coffee drunk per day. Passive smoking from ever having lived with a smoker or worked in a smoky workplace was also inversely related to PD. Ever having been a regular tea drinker was associated with decreased odds of PD. Hobby gardening was inversely associated with PD. However, use of fungicides in the home garden or occupationally was associated with increased odds of PD. Exposure to welding fumes, cleaning solvents, or thinners occupationally was associated with increased odds of PD. Ever having resided in a rural or remote area was inversely associated with PD. Ever having resided on a farm was only associated with moderately increased odds of PD. Whilst the current study's results suggest that environmental exposures on their own are only modest contributors to overall PD risk, the possibility that interaction with genetic factors may additively or synergistically increase risk should be considered. The results of this research support the theory that PD has a multifactorial aetiology and that environmental exposures are some of a number of factors to contribute to PD risk. There was also evidence of interaction between some factors (eg smoking and welding) to moderate PD risk.

Le choix du partenaire sexuel est l'une des décisions les plus importantes auxquelles sont confrontés les animaux au cours de leur vie. Une manière pour un individu de choisir un partenaire sexuel est de copier le choix de ses congénères. Bien que décrit dans différentes espèces de vertébrés et chez la Drosophila, ce processus d'imitation du choix du partenaire reste malgré tout peu compris. L'objectif de ma thèse a été d'étudier la capacité des femelles à choisir leur partenaire sexuel par imitation dans deux espèces de poisson, le poisson zèbre (Danio rerio) et la Gambusie de l'Est (Gambusia holbrooki), et d'étudier si cette capacité des femelles à imiter est corrélée à leur personnalité, plus particulièrement à leur caractère sur l'axe timide-audacieux. Les femelles poisson zèbre et G. holbrooki ont une préférence naturelle pour les grands mâles. Afin d'évaluer leur capacité à imiter, nous avons testé si, comme décrit dans d'autres espèces de poissons, les femelles augmentent leur préférence pour le petit male après avoir observé le grand male seul et le petit mâle en interaction avec une autre femelle. Nous n'avons pas pu mettre en évidence une tendance à imiter le choix de ses congénères chez des femelles poisson zèbre, suggérant que ce modèle n'est pas adapté pour étudier les mécanismes cognitifs sous-tenant le processus d'imitation du choix du partenaire (Article 1, Chapitre 2). Afin d'évaluer leur caractère exploratoire-audacieux, nous avons testé le comportement de ces mêmes femelles poisson zèbre dans un labyrinthe toutes les deux semaines, cinq fois de suite. Bien que nous ayons trouvé une répartition claire des individus le long de l'axe timide-audacieux dans le premier test, nous n'avons cependant pas pu détecter une répétabilité des comportements individuels à travers les tests suivants. Ceci était sans doute du au fait qu'après le premier test de personalité dans le labyrinthe, les femelles avaient appris que ce labyrinthe ne contenait aucun attracteur (alimentation ou congénère), ce qui les conduisaient à bouger de moins en moins dans le labyrinthe. Ainsi, bien que les traits de personnalité doivent persister au fil du temps, nos données suggèrent que la répétabilité des mesures dans un même test pourrait être faussée par l'apprentissage et l'habituation (Article 2, Chapitre 3). Finalement, nos données sur les femelles Gambusie de l'Est suggèrent que la capacité à imiter le choix d'un partenaire sexuel est liée à la personnalité des femelles: comme anticipé, seules les femelles timides, et non les plus audacieuses, montrent une réelle capacité à imiter le choix de leurs congénères femelles. Ce comportement des femelles timides est maximum lorsque la différence de taille entre les mâles est comprise entre 10% et 25%. Enfin, l'imitation du choix du partenaire semble également être affectée par la pression atmosphérique au moment de l'expérience, les femelles étant plus susceptibles d'imiter leurs congénères lorsque la pression de l'air augmente, en prévision de condition climatique favorable. Si nous avions ignoré ces effets confondants (personnalité, différence relative de taille des mâles attracteurs et pression atmosphérique), nous n'aurions pas détecté le comportement d'imitation du choix du partenaire sexuel chez la gambusie. Nous concluons qu'il est important de prendre en compte de tels effets confondants dans l'étude du comportement d'imitation du choix du partenaire social chez les autres espèces (Article 3, Chapitre 4). / Le choix du partenaire sexuel est l'une des décisions les plus importantes auxquelles sont confrontés les animaux au cours de leur vie. Une manière pour un individu de choisir un partenaire sexuel est de copier le choix de ses congénères. Bien que décrit dans différentes espèces de vertébrés et chez la Drosophila, ce processus d'imitation du choix du partenaire reste malgré tout peu compris. L'objectif de ma thèse a été d'étudier la capacité des femelles à choisir leur partenaire sexuel par imitation dans deux espèces de poisson, le poisson zèbre (Danio rerio) et la Gambusie de l'Est (Gambusia holbrooki), et d'étudier si cette capacité des femelles à imiter est corrélée à leur personnalité, plus particulièrement à leur caractère sur l'axe timide-audacieux. Les femelles poisson zèbre et G. holbrooki ont une préférence naturelle pour les grands mâles. Afin d'évaluer leur capacité à imiter, nous avons testé si, comme décrit dans d'autres espèces de poissons, les femelles augmentent leur préférence pour le petit male après avoir observé le grand male seul et le petit mâle en interaction avec une autre femelle. Nous n'avons pas pu mettre en évidence une tendance à imiter le choix de ses congénères chez des femelles poisson zèbre, suggérant que ce modèle n'est pas adapté pour étudier les mécanismes cognitifs sous-tenant le processus d'imitation du choix du partenaire (Article 1, Chapitre 2). Afin d'évaluer leur caractère exploratoire-audacieux, nous avons testé le comportement de ces mêmes femelles poisson zèbre dans un labyrinthe toutes les deux semaines, cinq fois de suite. Bien que nous ayons trouvé une répartition claire des individus le long de l'axe timide-audacieux dans le premier test, nous n'avons cependant pas pu détecter une répétabilité des comportements individuels à travers les tests suivants. Ceci était sans doute du au fait qu'après le premier test de personalité dans le labyrinthe, les femelles avaient appris que ce labyrinthe ne contenait aucun attracteur (alimentation ou congénère), ce qui les conduisaient à bouger de moins en moins dans le labyrinthe. Ainsi, bien que les traits de personnalité doivent persister au fil du temps, nos données suggèrent que la répétabilité des mesures dans un même test pourrait être faussée par l'apprentissage et l'habituation (Article 2, Chapitre 3). Finalement, nos données sur les femelles Gambusie de l'Est suggèrent que la capacité à imiter le choix d'un partenaire sexuel est liée à la personnalité des femelles: comme anticipé, seules les femelles timides, et non les plus audacieuses, montrent une réelle capacité à imiter le choix de leurs congénères femelles. Ce comportement des femelles timides est maximum lorsque la différence de taille entre les mâles est comprise entre 10% et 25%. Enfin, l'imitation du choix du partenaire semble également être affectée par la pression atmosphérique au moment de l'expérience, les femelles étant plus susceptibles d'imiter leurs congénères lorsque la pression de l'air augmente, en prévision de condition climatique favorable. Si nous avions ignoré ces effets confondants (personnalité, différence relative de taille des mâles attracteurs et pression atmosphérique), nous n'aurions pas détecté le comportement d'imitation du choix du partenaire sexuel chez la gambusie. Nous concluons qu'il est important de prendre en compte de tels effets confondants dans l'étude du comportement d'imitation du choix du partenaire social chez les autres espèces (Article 3, Chapitre 4).