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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

Cirurgia de catarata: opiniões, expectativas e reações emocionais de pacientes com visão mono versus binocular / Cataract surgery: opinions, expectances and emotional reactions of patients with monocular versus binocular vision

Marback, Roberta Ferrari 05 December 2007 (has links)
O estudo teve como objetivos verificar em dois grupos de pacientes com visão monocular (grupo 1) e com visão binocular (grupo 2), a serem submetidos à cirurgia de catarata no Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, opiniões, expectativas e reações emocionais em relação ao problema ocular, à qualidade da visão e à cirurgia de catarata; influência da característica de apresentar visão mono ou binocular nas reações emocionais relacionadas à cirurgia de catarata. Foi realizado estudo transversal e comparativo, de forma consecutiva, por meio de questionário estruturado, aplicado por entrevista a pacientes, elaborado a partir de estudo exploratório e medidas acuidade visual e causa da perda visual. A amostra foi constituída por 96 indivíduos do grupo 1 (50,0% homens; 50,0% mulheres, com idade entre 41 e 91 anos, média 69,3 anos ± 10,4 anos) e 110, do grupo 2 (40,9% homens; 59,1% mulheres, com idade entre 40 e 89 anos, média 68,2 anos ± 10,2 anos). A maioria dos indivíduos de ambos os grupos apresentava baixa escolaridade. Não houve diferença estatisticamente significante entre os grupos em relação ao sexo (p = 0,191), à idade (p = 0,702) e à escolaridade (p = 0,245). Não exerciam atividade laboral 95,8% dos indivíduos do grupo 1 e 83,6%, do grupo 2 (p = 0,005) e 30,4% do grupo 1 mencionaram não ter possibilidade de trabalhar por causa da deficiência visual. Observou-se acuidade visual do olho a ser operado menor que 0,05 em 40,6% (grupo 1) e 33,6% (grupo 2), entre 0,25 e 0,05. Quase a totalidade dos indivíduos de ambos os grupos afirmou ter dificuldade para realização das atividades de vida diária e qualificou como insuficiente a respectiva acuidade visual; 71,9% dos entrevistados do grupo 1 e 71,6%, do grupo 2 mencionaram saber a causa da visão fraca; desses, 87,1% do grupo 1 e 83,3% do grupo 2 referiram a catarata como causa da baixa acuidade visual. No que se refere ao medo, 40,6% dos indivíduos do grupo 1 e 22,7%, do grupo 2, relataram ter medo do procedimento cirúrgico (p = 0,009). As causas de medo mais referidas foram: possibilidade de perder a visão; piorar a visão; sofrer alguma complicação na cirurgia; morrer durante a cirurgia. Os sentimentos mais preponderantes entre os grupos foram: satisfação por saber que a catarata pode ser operada e melhorar a visão, alívio por saber que vai ser operado, dúvida quanto a ter bom resultado, nervosismo. Referiram esperar que mudanças ocorressem na vida após a cirurgia 90,6% (grupo 1) e 84,6% (grupo 2). Quanto às atividades que esperavam realizar após a cirurgia mencionaram: realizar serviços de casa; ler; sair sozinho. Concluiu-se que: os indivíduos de ambos os grupos tiveram acesso à cirurgia de catarata com acuidade visual menor do que a idealmente indicada; os pacientes com visão monocular apresentaram acuidade visual significativamente menor em relação aos com visão binocular; a maioria dos entrevistados de ambos os grupos referiu dificuldades para realizar atividades cotidianas como conseqüência da baixa visão; os indivíduos com visão monocular referiram mais dúvida em relação aos resultados cirúrgicos do que os com visão binocular; muitos indivíduos de ambos os grupos desconheciam a causa da dificuldade visual ou a atribuíram a outra causa que não a catarata; indivíduos de ambos os grupos apontaram expectativas positivas em relação à reabilitação após a cirurgia. / The purpose of the study was to verify in two groups of patients with monocular vision (group 1) and with binocular vision (group 2) to be submitted to cataract surgery in Hospital das Clínicas, São Paulo University Medical School, opinions, expectances and emotional reactions related to the ocular problem, to the quality of vision and to cataract surgery, the influence of monocular or binocular vision in the emotional reactions related to cataract surgery. A transversal comparative and consecutive study was performed using a structured questionnaire applied by interview of patients. The questionnaire was elaborated from a previous exploratory study, the visual acuity and cause of the visual loss were evaluated. The sample was constituted by 96 persons of group 1 (50% males; 50% females, ages ranging from 41 to 91 years old; average 69,3 years ± 10,4 years) and 110 persons of group 2 (40,9% males; 59,1% females, ages ranging from 40 to 89 years old; average 68,2 years ± 10,2 years). The majority of persons of both groups presented low educational level. There was no statistically significant difference between the groups in relation to gender (p = 0,191), age (p = 0,702) and educational level (p = 0,245). No work activity was mentioned in 95,8% of the persons of group 1 and 83,6% of group 2 (p = 0,005) and 30,4% of group 1 informed the impossibility to work due the visual deficiency. It was observed that the visual acuity of the eye to be operated was less than 0,05 in 40,6% (group 1) and in 33,6% (group 2), presented visual acuity ranging from 0,05 to 0,25. Almost the totality of the persons of both groups informed difficulties to perform activities of daily life and qualified as insufficient their visual acuities; 71,9% of the patients of group 1 and 71,6% of group 2 informed to know the reason of low vision; among these, 87,1% of group 1 and 83,3% of group 2 mentioned cataract as the reason of low visual acuity. Concerning fear, 40,6% of patients of group 1 and 22,7% of group 2 informed about fear of the surgical procedure (p = 0,009). The causes of fear more frequently reported were: possibility of loss of vision; worsening of vision; complications during the surgical procedure and to die during the surgery. The more preponderant feelings in both groups were: satisfaction knowing that a cataract can be operated with improvement of vision, relief knowing that will be submitted to surgery, doubt about a good result, nervousness. Changes in the life after surgery were mentioned by 90,6% (group 1) and by 84,6% (group 2) of the persons. Housework activities, reading and moving around without help were the mentioned activities expected to be performed after surgery. It was concluded that the patients of both groups were submitted to cataract surgery with visual acuities less than the visual acuity ideally indicated; the patients with monocular vision showed visual acuities significantly less in relation to the patients with binocular vision; the majority of the patients of both groups mentioned difficulties to perform daily activities as a consequence of low vision; patients with monocular vision mentioned doubts in relation to the surgical results as compared with the patients with binocular vision; many patients of both groups did not know the cause of the visual difficulty or explained the visual difficulty by other cause than the cataract; patients of both groups were positively expectant in relation to the visual rehabilitation after the surgery.
42

Cirurgia de catarata: opiniões, expectativas e reações emocionais de pacientes com visão mono versus binocular / Cataract surgery: opinions, expectances and emotional reactions of patients with monocular versus binocular vision

Roberta Ferrari Marback 05 December 2007 (has links)
O estudo teve como objetivos verificar em dois grupos de pacientes com visão monocular (grupo 1) e com visão binocular (grupo 2), a serem submetidos à cirurgia de catarata no Hospital das Clínicas da Faculdade de Medicina da Universidade de São Paulo, opiniões, expectativas e reações emocionais em relação ao problema ocular, à qualidade da visão e à cirurgia de catarata; influência da característica de apresentar visão mono ou binocular nas reações emocionais relacionadas à cirurgia de catarata. Foi realizado estudo transversal e comparativo, de forma consecutiva, por meio de questionário estruturado, aplicado por entrevista a pacientes, elaborado a partir de estudo exploratório e medidas acuidade visual e causa da perda visual. A amostra foi constituída por 96 indivíduos do grupo 1 (50,0% homens; 50,0% mulheres, com idade entre 41 e 91 anos, média 69,3 anos ± 10,4 anos) e 110, do grupo 2 (40,9% homens; 59,1% mulheres, com idade entre 40 e 89 anos, média 68,2 anos ± 10,2 anos). A maioria dos indivíduos de ambos os grupos apresentava baixa escolaridade. Não houve diferença estatisticamente significante entre os grupos em relação ao sexo (p = 0,191), à idade (p = 0,702) e à escolaridade (p = 0,245). Não exerciam atividade laboral 95,8% dos indivíduos do grupo 1 e 83,6%, do grupo 2 (p = 0,005) e 30,4% do grupo 1 mencionaram não ter possibilidade de trabalhar por causa da deficiência visual. Observou-se acuidade visual do olho a ser operado menor que 0,05 em 40,6% (grupo 1) e 33,6% (grupo 2), entre 0,25 e 0,05. Quase a totalidade dos indivíduos de ambos os grupos afirmou ter dificuldade para realização das atividades de vida diária e qualificou como insuficiente a respectiva acuidade visual; 71,9% dos entrevistados do grupo 1 e 71,6%, do grupo 2 mencionaram saber a causa da visão fraca; desses, 87,1% do grupo 1 e 83,3% do grupo 2 referiram a catarata como causa da baixa acuidade visual. No que se refere ao medo, 40,6% dos indivíduos do grupo 1 e 22,7%, do grupo 2, relataram ter medo do procedimento cirúrgico (p = 0,009). As causas de medo mais referidas foram: possibilidade de perder a visão; piorar a visão; sofrer alguma complicação na cirurgia; morrer durante a cirurgia. Os sentimentos mais preponderantes entre os grupos foram: satisfação por saber que a catarata pode ser operada e melhorar a visão, alívio por saber que vai ser operado, dúvida quanto a ter bom resultado, nervosismo. Referiram esperar que mudanças ocorressem na vida após a cirurgia 90,6% (grupo 1) e 84,6% (grupo 2). Quanto às atividades que esperavam realizar após a cirurgia mencionaram: realizar serviços de casa; ler; sair sozinho. Concluiu-se que: os indivíduos de ambos os grupos tiveram acesso à cirurgia de catarata com acuidade visual menor do que a idealmente indicada; os pacientes com visão monocular apresentaram acuidade visual significativamente menor em relação aos com visão binocular; a maioria dos entrevistados de ambos os grupos referiu dificuldades para realizar atividades cotidianas como conseqüência da baixa visão; os indivíduos com visão monocular referiram mais dúvida em relação aos resultados cirúrgicos do que os com visão binocular; muitos indivíduos de ambos os grupos desconheciam a causa da dificuldade visual ou a atribuíram a outra causa que não a catarata; indivíduos de ambos os grupos apontaram expectativas positivas em relação à reabilitação após a cirurgia. / The purpose of the study was to verify in two groups of patients with monocular vision (group 1) and with binocular vision (group 2) to be submitted to cataract surgery in Hospital das Clínicas, São Paulo University Medical School, opinions, expectances and emotional reactions related to the ocular problem, to the quality of vision and to cataract surgery, the influence of monocular or binocular vision in the emotional reactions related to cataract surgery. A transversal comparative and consecutive study was performed using a structured questionnaire applied by interview of patients. The questionnaire was elaborated from a previous exploratory study, the visual acuity and cause of the visual loss were evaluated. The sample was constituted by 96 persons of group 1 (50% males; 50% females, ages ranging from 41 to 91 years old; average 69,3 years ± 10,4 years) and 110 persons of group 2 (40,9% males; 59,1% females, ages ranging from 40 to 89 years old; average 68,2 years ± 10,2 years). The majority of persons of both groups presented low educational level. There was no statistically significant difference between the groups in relation to gender (p = 0,191), age (p = 0,702) and educational level (p = 0,245). No work activity was mentioned in 95,8% of the persons of group 1 and 83,6% of group 2 (p = 0,005) and 30,4% of group 1 informed the impossibility to work due the visual deficiency. It was observed that the visual acuity of the eye to be operated was less than 0,05 in 40,6% (group 1) and in 33,6% (group 2), presented visual acuity ranging from 0,05 to 0,25. Almost the totality of the persons of both groups informed difficulties to perform activities of daily life and qualified as insufficient their visual acuities; 71,9% of the patients of group 1 and 71,6% of group 2 informed to know the reason of low vision; among these, 87,1% of group 1 and 83,3% of group 2 mentioned cataract as the reason of low visual acuity. Concerning fear, 40,6% of patients of group 1 and 22,7% of group 2 informed about fear of the surgical procedure (p = 0,009). The causes of fear more frequently reported were: possibility of loss of vision; worsening of vision; complications during the surgical procedure and to die during the surgery. The more preponderant feelings in both groups were: satisfaction knowing that a cataract can be operated with improvement of vision, relief knowing that will be submitted to surgery, doubt about a good result, nervousness. Changes in the life after surgery were mentioned by 90,6% (group 1) and by 84,6% (group 2) of the persons. Housework activities, reading and moving around without help were the mentioned activities expected to be performed after surgery. It was concluded that the patients of both groups were submitted to cataract surgery with visual acuities less than the visual acuity ideally indicated; the patients with monocular vision showed visual acuities significantly less in relation to the patients with binocular vision; the majority of the patients of both groups mentioned difficulties to perform daily activities as a consequence of low vision; patients with monocular vision mentioned doubts in relation to the surgical results as compared with the patients with binocular vision; many patients of both groups did not know the cause of the visual difficulty or explained the visual difficulty by other cause than the cataract; patients of both groups were positively expectant in relation to the visual rehabilitation after the surgery.
43

A visão monocular e a aposentadoria especial da pessoa com deficiência / The monocular vision and the special retirement of the disable person

Lino, Leandro Jorge de Oliveira [UNESP] 11 October 2017 (has links)
Submitted by LEANDRO JORGE DE OLIVEIRA LINO null (leandro@linoadvocacia.com.br) on 2017-10-27T13:21:12Z No. of bitstreams: 1 LEANDRO JORGE DE OLIVEIRA LINO final.pdf: 6685626 bytes, checksum: ca924e90dae458da44758c8379477568 (MD5) / Rejected by Monique Sasaki (sayumi_sasaki@hotmail.com), reason: Solicitamos que realize uma nova submissão seguindo a orientação abaixo: O arquivo submetido está sem a ficha catalográfica. A versão submetida por você é considerada a versão final da dissertação/tese, portanto não poderá ocorrer qualquer alteração em seu conteúdo após a aprovação. Corrija esta informação e realize uma nova submissão contendo o arquivo correto. Agradecemos a compreensão. on 2017-10-31T19:32:41Z (GMT) / Submitted by LEANDRO JORGE DE OLIVEIRA LINO null (leandro@linoadvocacia.com.br) on 2017-10-31T19:55:36Z No. of bitstreams: 1 LEANDRO JORGE DE OLIVEIRA LINO final.pdf: 6431885 bytes, checksum: 0fb0c0bcbfe43eb0c1d404555b6e1d66 (MD5) / Approved for entry into archive by LUIZA DE MENEZES ROMANETTO (luizamenezes@reitoria.unesp.br) on 2017-11-08T17:55:13Z (GMT) No. of bitstreams: 1 lino_ljo_me_fran.pdf: 6431885 bytes, checksum: 0fb0c0bcbfe43eb0c1d404555b6e1d66 (MD5) / Made available in DSpace on 2017-11-08T17:55:13Z (GMT). No. of bitstreams: 1 lino_ljo_me_fran.pdf: 6431885 bytes, checksum: 0fb0c0bcbfe43eb0c1d404555b6e1d66 (MD5) Previous issue date: 2017-10-11 / De acordo com o censo realizado pelo Instituto Brasileiro de Geografia e Estatística em 2010, identificou-se que 18,8% da população nacional são pessoas com alguma espécie de deficiência visual. Ante a esse expressivo número, figura-se ser importante para o mundo jurídico a análise do conceito de pessoa com deficiência visual e suas modificações ao longo do tempo, principalmente, quando, na práxis forense e administrativa previdenciária, observa-se a segregação de pessoas detentoras de deficiência visual monocular deste conceito jurídico. Há também ainda, a interpretação de legislações vigentes, que ainda trazem um conceito superado do que se considera pessoa com deficiência. Para conceituá-la, inicialmente, se utilizou o modelo exclusivamente médico lastreado em limitações físicas; passo seguinte se adotou o modelo social, cujo enfoque era a opressão social sofrida pelas pessoas com deficiência; e, atualmente, o modelo utilizado é o biopsicossocial, analisando-se a pessoa com deficiência por intermédio de perícia médica e social, conjugando a análise dos impedimentos corpóreos de longo prazo, frente às barreiras sociais, ambientais e atitudinais existentes. Para as legislações que usam o modelo médico restritivamente, o possuidor de visão monocular não se enquadra no conceito de pessoa com deficiência. Contudo, por todos os modelos, o médico, social ou biopsicossocial, é possível se considerar a pessoa com visão monocular como pessoa com deficiência visual. Nesse contexto, e com iguais propósitos, tem-se que analisar o conceito jurídico-constitucional da pessoa com deficiência visual, para fins de reconhecimento do direito ao gozo da aposentadoria especial nesta condição, aos possuidores de visão monocular. Apesar de serem possuidores de Cegueira ou Deficiência Visual Grave ou Moderada por critérios médicos, têm sido excluídas do acesso a vários direitos, inclusive desta espécie de aposentadoria, vez que, regra geral em termos legais expressos, não são considerados pessoas com deficiência visual. O objetivo deste trabalho, portanto, é analisar a evolução desses modelos e aferir o grau de proteção social hoje conferido à pessoa com deficiência visual, em especial no caso da visão monocular, principalmente no que concernente à concessão de aposentadoria especial da pessoa com deficiência. / According to the census done by Brazilian Institute of Geography and Statistics in 2010, was identified that 18.8% of the national population are persons with, at least, one kind of visual impairment. Before this expressive number, ifigures out that, it has been important to the legal word, the concept analisys of a person with visual impairment and its modifications along the time, specially, when, in the forensic and administrative social security praxis, it is noted a segregation of detaining persons with monocular vison deficiency at this legal concept. There is even, a legislation in force version, that it is still giving a concept surpassed of what, at the beginning, was used as an exclusively backed medical model considering the person with visual impairment. To concept it, the physical limitations; the next step is adopted a social model, whose approach was based in the social oppression suffered by the persons with deficiency; and, actually, this used model is the biopsychosocial, analysing the person with this disable throughout the social and medical expertise, joining the longterm bodily impediments analisys, facing the social, environmental and existing attitudinal barriers. For the legilations that use a restrict medical model, the monocular vision possessor does not fit as a person with deficiency. However, for all the kinds of models, like medical, social or biopsychosocial, it is possible to consider a person with monocular vison as one with visual impairment. In this context, and with same purposes, there is a way to analyse the conditions of a visual impairment person and the monocular vison possessor legal-constitutional concept, to recognize the rights of a special retirement enjoyment. In spite of being Severe or Moderate Vision or Blindness possessor by medical criteria, it has been excluded of many right accesses, including this kind of retirement, once that, the general rules, in expressive legal therms, are not considered persons with visual impairment. The purpose of this research is, therefore, to analyse these models evolution and to assess the degree of social protection to a person with visual impairment nowadays, in a special case, the monocular vision one, mainly in relation to the granting of special retirement of the disabled person.
44

Localiza??o e mapeamento simult?neos de ambientes planos usando vis?o monocular e representa??o h?brida do ambiente

Santana, Andr? Mac?do 11 February 2011 (has links)
Made available in DSpace on 2014-12-17T14:54:56Z (GMT). No. of bitstreams: 1 AndreMS_TESE_1-100.pdf: 5113772 bytes, checksum: 19386f80f787c926c4fb29b85bac4ecf (MD5) Previous issue date: 2011-02-11 / The goal of this work is to propose a SLAM (Simultaneous Localization and Mapping) solution based on Extended Kalman Filter (EKF) in order to make possible a robot navigates along the environment using information from odometry and pre-existing lines on the floor. Initially, a segmentation step is necessary to classify parts of the image in floor or non floor . Then the image processing identifies floor lines and the parameters of these lines are mapped to world using a homography matrix. Finally, the identified lines are used in SLAM as landmarks in order to build a feature map. In parallel, using the corrected robot pose, the uncertainty about the pose and also the part non floor of the image, it is possible to build an occupancy grid map and generate a metric map with the obstacle s description. A greater autonomy for the robot is attained by using the two types of obtained map (the metric map and the features map). Thus, it is possible to run path planning tasks in parallel with localization and mapping. Practical results are presented to validate the proposal / O objetivo desta tese ? apresentar uma t?cnica de SLAM (Localiza??o e Mapeamento Simult?neos) adequada para ambientes planos com linhas presentes no ch?o, de modo a permitir que o rob? navegue no ambiente fundindo informa??es de odometria e de vis?o monocular. Inicialmente, ? feita uma etapa de segmenta??o para classificar as partes da imagem em ch?o e n?o-ch?o . Em seguida, o processadomento de imagem identifica linhas na parte ch?o e os par?metros dessas linhas s?o mapeados para o mundo, usando uma matriz de homografia. Finalmente, as linhas identificadas s?o usadas como marcos no SLAM, para construir um mapa de caracter?sticas. Em paralelo, a pose corrigida do rob?, a incerteza em rela??o ? pose e a parte n?och?o da imagem s?o usadas para construir uma grade de ocupa??o, gerando um mapa m?trico com descri??o dos obst?culos. A utiliza??o simult?nea dos dois tipos de mapa obtidos (m?trico em grade e de caracter?sticas) d? maior autonomia ao rob?, permitindo acrescentar tarefas de planejamento em simult?neo com a localiza??o e mapeamento. Resultados pr?ticos s?o apresentados para validar a proposta
45

A visão monocular e a aposentadoria especial da pessoa com deficiência /

Lino, Leandro January 2017 (has links)
Orientador: Juliana Presotto Pereira Netto / Resumo: De acordo com o censo realizado pelo Instituto Brasileiro de Geografia e Estatística em 2010, identificou-se que 18,8% da população nacional são pessoas com alguma espécie de deficiência visual. Ante a esse expressivo número, figura-se ser importante para o mundo jurídico a análise do conceito de pessoa com deficiência visual e suas modificações ao longo do tempo, principalmente, quando, na práxis forense e administrativa previdenciária, observa-se a segregação de pessoas detentoras de deficiência visual monocular deste conceito jurídico. Há também ainda, a interpretação de legislações vigentes, que ainda trazem um conceito superado do que se considera pessoa com deficiência. Para conceituá-la, inicialmente, se utilizou o modelo exclusivamente médico lastreado em limitações físicas; passo seguinte se adotou o modelo social, cujo enfoque era a opressão social sofrida pelas pessoas com deficiência; e, atualmente, o modelo utilizado é o biopsicossocial, analisando-se a pessoa com deficiência por intermédio de perícia médica e social, conjugando a análise dos impedimentos corpóreos de longo prazo, frente às barreiras sociais, ambientais e atitudinais existentes. Para as legislações que usam o modelo médico restritivamente, o possuidor de visão monocular não se enquadra no conceito de pessoa com deficiência. Contudo, por todos os modelos, o médico, social ou biopsicossocial, é possível se considerar a pessoa com visão monocular como pessoa com deficiência visual. Nesse contexto, e... (Resumo completo, clicar acesso eletrônico abaixo) / Mestre
46

Simultaneous localisation and mapping using a single camera

Williams, Brian P. January 2009 (has links)
This thesis describes a system which is able to track the pose of a hand-held camera as it moves around a scene. The system builds a 3D map of point landmarks in the world while tracking the pose of the camera relative to this map using a process called simultaneous localisation and mapping (SLAM). To achieve real-time performance, the map must be kept sparse, but rather than observing only the mapped landmarks like previous systems, observations are made of features across the entire image. Their deviation from the predicted epipolar geometry is used to further constrain the estimated inter-frame motion and so improves the overall accuracy. The consistency of the estimation is also improved by performing the estimation in a camera-centred coordinate frame. As with any such system, tracking failure is inevitable due to occlusion or sudden motion of the camera. A relocalisation module is presented which monitors the SLAM system, detects tracking failure, and then resumes tracking as soon as the conditions have improved. This relocalisation process is achieved using a new landmark recognition algorithm which is trained on-line and provides high recall and a fast recognition time. The relocalisation module can also be used to achieve place recognition for a loop closure detection system. By taking into account both the geometry and appearance information when determining a loop closure this module is able to outperform previous loop closure detection techniques used in monocular SLAM. After recognising an overlap, the map is then corrected using a novel trajectory alignment technique that is able to cope with the inherent scale ambiguity in monocular SLAM. By incorporating all of these new techniques, the system presented can perform as a robust augmented reality system, or act as a navigation tool which could be used on a mobile robot in indoor and outdoor environments.
47

Acuidade visual e matriz extracelular no córtex visual primário: alterações associadas à privação monocular precoce e ao enriquecimento ambiental

SILVA, Nonata Lucia Trévia da 08 November 2012 (has links)
Submitted by Irvana Coutinho (irvana@ufpa.br) on 2013-01-25T14:29:10Z No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_ AcuidadeVisualMatriz.pdf: 2171256 bytes, checksum: ce1733a75cf4138644c2b48ef3377b5b (MD5) / Approved for entry into archive by Ana Rosa Silva(arosa@ufpa.br) on 2013-01-25T17:00:07Z (GMT) No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_ AcuidadeVisualMatriz.pdf: 2171256 bytes, checksum: ce1733a75cf4138644c2b48ef3377b5b (MD5) / Made available in DSpace on 2013-01-25T17:00:07Z (GMT). No. of bitstreams: 2 license_rdf: 23898 bytes, checksum: e363e809996cf46ada20da1accfcd9c7 (MD5) Dissertacao_ AcuidadeVisualMatriz.pdf: 2171256 bytes, checksum: ce1733a75cf4138644c2b48ef3377b5b (MD5) Previous issue date: 2012 / CNPq - Conselho Nacional de Desenvolvimento Científico e Tecnológico / O objetivo do presente trabalho e analisar a influencia do enriquecimento ambiental sobre a acuidade visual e a distribuição das redes perineuronais (RPNs) no córtex visual primário de camundongos submetidos a privação monocular durante o período critico pos-natal. Camundongos suíços albinos fêmeas foram submetidos a sutura da pálpebra direita no 10o dia pos-natal (M, n=16), enquanto que os animais do grupo binocular não foram submetidos a nenhum procedimento cirúrgico (B, n=16). Ao completarem 21 dias, os animais foram subdivididos em: ambiente padrão e ambiente enriquecido, constituindo os grupos M.AP, M.AE, B.AP e B.AE. Após três meses, os animais foram submetidos ao teste de acuidade visual, perfundidos e secções coronais de seus cérebros processadas para histoquímica da lectina Wisteria floribunda e posterior quantificação através do método estereologico do fracionador óptico. Os animais do grupo B.AP apresentaram acuidade visual de 0.48 ciclos/grau, enquanto que aqueles alojados em ambiente enriquecido (B.AE) apresentaram um melhor desempenho do teste, atingindo 0.996 ciclos/grau. A acuidade visual foi significantemente menor nos animais submetidos a privação monocular (M.AP 0.18 ciclos/grau; M.AE 0.4 ciclos/grau). Os resultados estereologicos revelaram que o ambiente enriquecido aumenta o numero de RPNs tipo 1 e de RPNs total nas camadas supragranular e granular em ambos os hemisférios nos camundongos submetidos a privação monocular (ANOVA dois critérios, p<0.05), sendo que essa diferença na camada granular e decorrente principalmente do aumento das redes perineuronais da matriz extracelular no hemisfério direito. Na camada infragranular, os animais do grupo M.AE apresentaram um aumento apenas no numero de RPNs tipo 1. / The aim of the present study is to analyze the influence of enriched environment on the visual acuity and on the distribution of perineuronal nets (PNNs) in the primary visual cortex of albino mice that underwent monocular deprivation during the critical period of postnatal development. Mice at 10th postnatal day, were monocular deprived through right eye-lid sutured (M, n = 16) and the control group animals were not submitted to any cirurgical procedures (B, n = 16). After weaning, on postnatal day 21, animals were subdivided in: standard environment (AP) and enriched environment (AE), constituting the following groups: M.AP, M.AE, B.AP and B.AE. After 3 months, animals were submitted to grating visual acuity tests, perfused and coronal sections of their brains processed for Wisteria floribunda agglutinin to posterior stereological quantification through optical fractionator method. B.AP animals present visual acuity of 0.48 cycles/degree, while those raised in enriched environment (B.AE) present a better performance at visual test, reaching 0.996 cycles/degree. Animals with monocular deprivation had significantly lower visual acuity (M.AP 0.18 cycles/degree; M.AE 0.4 cycles/degree). Stereological quantifications revealed that enriched environment increases type 1 and the total number of perineuronal nets at supragranular and granular layers in both hemispheres of deprived animals (ANOVA, two-ways, p < 0.05) and this difference at granular layer is due to an increase of perineuronal nets mainly at the right hemisphere (ipsilateral to the monocular deprivation). At infragranular layer, M.AE animals presented an increase only at the number of type 1 PNNs in both hemispheres.
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Direct interaction with large displays through monocular computer vision

Cheng, Kelvin January 2009 (has links)
Doctor of Philosophy (PhD) / Large displays are everywhere, and have been shown to provide higher productivity gain and user satisfaction compared to traditional desktop monitors. The computer mouse remains the most common input tool for users to interact with these larger displays. Much effort has been made on making this interaction more natural and more intuitive for the user. The use of computer vision for this purpose has been well researched as it provides freedom and mobility to the user and allows them to interact at a distance. Interaction that relies on monocular computer vision, however, has not been well researched, particularly when used for depth information recovery. This thesis aims to investigate the feasibility of using monocular computer vision to allow bare-hand interaction with large display systems from a distance. By taking into account the location of the user and the interaction area available, a dynamic virtual touchscreen can be estimated between the display and the user. In the process, theories and techniques that make interaction with computer display as easy as pointing to real world objects is explored. Studies were conducted to investigate the way human point at objects naturally with their hand and to examine the inadequacy in existing pointing systems. Models that underpin the pointing strategy used in many of the previous interactive systems were formalized. A proof-of-concept prototype is built and evaluated from various user studies. Results from this thesis suggested that it is possible to allow natural user interaction with large displays using low-cost monocular computer vision. Furthermore, models developed and lessons learnt in this research can assist designers to develop more accurate and natural interactive systems that make use of human’s natural pointing behaviours.
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Visual space attention in three-dimensional space

Tucker, Andrew James, n/a January 2006 (has links)
Current models of visual spatial attention are based on the extent to which attention can be allocated in 2-dimensional displays. The distribution of attention in 3-dimensional space has received little consideration. A series of experiments were devised to explore the apparent inconsistencies in the literature pertaining to the allocation of spatial attention in the third dimension. A review of the literature attributed these inconsistencies to differences and limitations in the various methodologies employed, in addition to the use of differing attentional paradigms. An initial aim of this thesis was to develop a highly controlled novel adaptation of the conventional robust covert orienting of visual attention task (COVAT) in depth defined by either binocular (stereoscopic) or monocular cues. The results indicated that attentional selection in the COVAT is not allocated within a 3-dimensional representation of space. Consequently, an alternative measure of spatial attention in depth, the overlay interference task, was successfully validated in a different stereoscopic depth environment and then manipulated to further examine the allocation of attention in depth. Findings from the overlay interference experiments indicated that attentional selection is based on a representation that includes depth information, but only when an additional feature can aid 3D selection. Collectively, the results suggest a dissociation between two paradigms that are both purported to be measures of spatial attention. There appears to be a further dissociation between 2-dimensional and 3-dimensional attentional selection in both paradigms for different reasons. These behavioural results, combined with recent electrophysiological evidence suggest that the temporal constraints of the 3D COVAT paradigm result in early selection based predominantly on retinotopic spatial coordinates prior to the complete construction of a 3-dimensional representation. Task requirements of the 3D overlay interference paradigm, on the other hand, while not being restricted by temporal constraints, demand that attentional selection occurs later, after the construction of a 3-dimensional representation, but only with the guidance of a secondary feature. Regardless of whether attentional selection occurs early or late, however, some component of selection appears to be based on viewer-centred spatial coordinates.
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空間注意力經由深度影響模稜運動知覺 / The effect of spatial attention on multistable motion perception via the depth mechanism

孫華君, Sun, Hua Chun Unknown Date (has links)
Many studies have found that fixating or directing spatial attention to different regions can bias the perception of the Necker cube, but whether this effect of spatial attention is due to attended areas perceived as being closer have yet to be examined. This issue was directly investigated in this study. The stimulus used was the diamond stimulus, containing four occluders and four moving lines that can be perceived as coherent or separate motions. The results of Experiment 1 show that coherent motion was perceived more often under the attending-to-occluders condition than under the attending-to-moving-lines condition, indicating that spatial attention can bias multistable perception. The results of Experiment 2 show that the mean probability of reporting lines behind occluders in small binocular disparities was significantly higher under the attending-to-occluders condition than under the attending-to-lines condition, indicating that spatial attention can make attended areas look slightly closer. The results of Experiments 3 and 4 show that the effect of spatial attention on biasing multistable perception was weakened when there were binocular or monocular depth cues to define the depth relationship between the occluders and the lines. These results are all consistent with the notion that spatial attention can bias multistable perception through affecting depth perception, making attended areas look closer.

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