Les troubles cognitives regroupent un ensemble hétérogène d’altérations décrites dans la schizophrénie. Parmi elles, il a été montré que les patients présentent des difficultés à distinguer des informations pertinentes parmi des distracteurs ou encore qu’ils sont particulièrement attirés par l’apparition d’une information soudaine même si celle-ci est non pertinente à la compréhension de la scène. Nos travaux ont pour objectif de préciser ces déficits cognitifs, en se rapprochant des conditions naturelles d’exploration visuelle.L’étude des fixations oculaires permet de mettre en évidence des stratégies d’exploration visuelle et d’évaluer l’impact de la saillance des stimuli sur cette exploration. La saillance se définit comme l’émergence d’une forme sur un fond, et comprend la saillance cognitive (pertinence de l’objet), saillance visuelle (caractéristiques physiques) ou saillance émotionnelle. Le paradigme de cécité au changement est défini comme la surprenante difficulté à détecter un changement lorsque celui-ci survient lors d’une interruption visuelle tel un mouvement de l’oeil. Ce paradigme a pour avantage de permettre de se rapprocher des conditions écologiques d’exploration en utilisant des stimuli en 3D. Plusieurs études ont évalué les facteurs influençant la détection des objets changés avec ce paradigme. Ainsi, l’intérêt de l’objet à la compréhension de la scène, le caractère incongru de l’objet, la couleur, la forme ou la taille de l’objet sont des caractéristiques favorisant la détection du changement.Nos premiers travaux ont consisté en la réalisation de deux études en population saine testant l’influence de deux facteurs sur la détection des changements : l’amplitude des changements et le charge émotionnelle de l’objet changé.Notre première étude a montré que plus la scène contient de changements, plus la détection d’au moins un changement est rapide et précise.Notre seconde étude a montré que la charge émotionnelle portée par les objets changés influençait leur détection. En effet les objets dits émotionnels sont mieux détectés que les objets dits neutres.Nos seconds travaux se sont focalisés sur l’exploration visuelle de patients atteints de schizophrénie comparés à des sujets sains lors de la présentation de scènes de la vie quotidienne. Un paradigme de cécité au changement comprenant des changements non pertinents à la compréhension de la scène, testant ainsi l’impact de la saillance cognitive, a été utilisé. Les variables enregistrées ont été les temps de réponse moteur et des données d’oculomotricité (temps avant la première fixation en zone de changement). Nos résultats montrent une dissociation entre des réponses implicites et explicites : les yeux des patients se fixent plus rapidement sur les changements alors qu’ils rapportent les changements plus lentement que les sujets sains.Enfin dans notre troisième étude, nous avons comparé l’effet de l’apparition soudaine d’une information visuelle à caractère neutre avec l’apparition soudaine d’une information visuelle à caractère émotionnelle en utilisant une tâche écologique de cécité au changement chez des patients atteints de schizophrénie comparés à des sujets sains.Les résultats montrent que la charge émotionnelle portée par les objets changés favorise leur détection uniquement pour les sujets sains.Nous confirmons la sensibilité à l’apparition soudaine d’une information visuelle grâce à un paradigme qui mesure de meilleures performances pour les patients ce qui réduit les effets d’un déficit attentionnel non spécifique. Par ailleurs, les meilleures performances de détection disparaissent dès qu’intervient une charge émotionnelle soulignant les difficultés du traitement des émotions dans la schizophrénie. La surprenante dissociation entre les réponses motrices et oculomotrices pourrait être interprétée comme un déficit d’accès à la conscience perceptive dans la schizophrénie et ainsi ouvrir la voie à des pistes thérapeutiques. / Cognitive impairment includes a heterogeneous set of disorders found in patients with schizophrenia. Among them, patients exhibit clear disadvantages in filtering relevant information in a flow of distractors or the attention of these patients can be captured by the sudden irruption of visual information, even if irrelevant to understand the scene. The objective of our research is to specify these cognitive disorders by approaching the ecological conditions of visual exploration.The study of eye fixations allows to highlight visual exploration strategies or to assess the impact of the stimuli salience on the visual exploration. The salience is defined as the emergence of a form on a background. We can observed a cognitive salience (the object’s relevance), a physical salience (the physical characteristics) or emotional salience. The paradigm of change blindness is defined by the failure to notice changes in scene when these changes occur following brief disruptions, such as eye movements. This paradigm exhibits the advantage to approach natural conditions of exploration using 3D stimuli. Several studies have evaluated different factors having an impact on the detection of changed object with this paradigm. Therefore, the interest of the main object to the comprehension of the scene, the incongruous objects, color, shape or size of the object are characteristics promoting the detection of change.Our initial task consists of the conduct of two distinct studies with healthy subjects testing the influence of two factors on the detection of change: the magnitude of change and the emotional aspect of changed objects. Our first study showed that the more the scene contains changes, the faster, the more efficient we detect at least one change. Our second study showed that the emotional aspect of changed objects impacted their detection. Indeed emotional objects are best detected that neutral objects.Our second study has focused on the visual exploration of patients with schizophrenia compared to healthy subjects during the presentation of scenes of everyday life. We used a paradigm of change blindness including irrelevant changes in the understanding of the scene. This paradigm allows to test the cognitive salience. The main recorded variables were the motor response time and eye tracking data (the latency of the first fixation in a region of interest). Our results exhibited a striking dissociation between the explicit and implicit responses: the patients\\\\\\\' eyes shifted faster toward the changes despite explicitly reporting the change more slowly than the healthy subjects.Finally in our third study, we compared the effect of the sudden irruption of an emotional visual information with the sudden irruption of a neutral visual information using an ecological task of change blindness. We compared patients with schizophrenia to healthy subjects. Results show that changes in emotional objects are better detected than changes in neutral objects only for the healthy subjects.We confirmed the patients\\\\\\\' sensitivity to the sudden onset of visual information with a paradigm that measured a better performance in the patients, which thereby reduced the effects of a non-specific attentional deficit. Moreover, the better detection performances disappear when changes lay an emotional influence, highlighting the difficulties of emotional processing in schizophrenia. Finally, the surprising dissociation between implicit and explicit responses in schizophrenia can be interpreted as a deficit of access to conscious perception, which could be of interest to various therapeutic techniques.

Dentre os genes conhecidos por influenciarem a variação normal de pigmentação de olhos, pele e cabelos em humanos, o gene MC1R (receptor de melanocortina 1) é o mais bem caracterizado até o momento. A atuação do MC1R ocorre pela produção de uma proteína transmembrana nos melanócitos, responsável pela regulação da produção de melanina nos mesmos. Sabe-se que a atuação do MC1R determina a proporção entre eumelanina (coloração castanha/preta) e feomelanina (coloração amarela/vermelha) presente nos melanócitos. O presente trabalho tem como objetivo analisar os SNPs conhecidos do gene MC1R com o propósito de se avaliar a influência da diversidade deste gene em características como a presença de sardas e variação da pigmentação dos olhos, pele e cabelos em humanos. Foram analisados 29 SNPs conhecidos da região codificadora do gene MC1R em 131 indivíduos da região de Ribeirão Preto, SP. A extração do DNA foi feita pela técnica de salting-out. A região codificadora do gene MC1R (951pb) foi amplificada em uma única reação de PCR, a qual foi seqüenciada em um analisador genético ABI-PRISM 310 por eletroforese capilar, utilizando-se os mesmos primers empregados para a amplificação. Dos 29 SNPs avaliados, 22 deles mostraram variação nas amostras estudadas, sendo que metade deles demonstrou estar associados a características de pigmentação. Observou-se um conjunto de SNPs associados claramente à fenótipos relacionados à feomelanina (+1645 A, +1858 T e +2260 C), enquanto outros se relacionam à ocorrência de eumelanina (+1558 G, +2322 G, +2346 A). A reconstrução de haplótipos gerou 31 haplótipos, sendo que quatro deles estavam associados à pele escura e dois outros tinham freqüências significativamente baixas em pele clara. Um haplótipo se associou a olhos verdes, enquanto dois outros tiveram associação com olhos castanho escuros. Cores escuras de cabelo se relacionaram à seis haplótipos distintos enquanto cabelos ruivos estavam associados à dois e um outro associado à cabelos loiros. Por fim, a ocorrência de sardas foi significativamente relacionada à três haplótipos. O presente trabalho apresenta associações significativas entre SNPs individuais e pigmentação de olhos, cabelos e pele, sendo que nossos dados confirmam que tal gene também desempenha papel relevante na variação de pigmentação na população brasileira. / Among the known genes influencing eye, skin and hair normal pigmentation variation, the MC1R (melanocortin l-receptor) gene is the best characterized so far. The activity of MC1R occurs due the production of a transmembrane protein in melanocytes, responsible for regulating the production of melanin. It is known that the performance of MC1R determines the ratio of eumelanin (brown color I black) and pheomelanin (yellow I red) present in melanocytes. This study aims to analyze known SNPs of the MC1R gene in order to evaluate the influence of this gene diversity on features like freckles and pigmentation variation of eyes, skin and hair in humans. We analyzed 29 known SNPs in the coding region of MC1R gene in 296 individuals from the region of Ribeirao Preto, Brazil. DNA extraction was performed using the salting-out technique. The MC1R gene coding region (951pb) was amplified in a single PCR reaction, which was sequenced on a ABI PRISM-310 genetic analyzer by capillary electrophoresis, using the same primers used for amplification. Of the 29 SNPs evaluated, only 22 showed variation in the samples studied, half of them showing to be associated with pigmentation characteristics. We observed a set of SNPs clearly associated to pheomelanin (+1645 A, +1831 T,+1858 T e +2260 C), while others related to eumelanin occurrence (+1558 G, +2322 G, +2346 A).Haplotype reconstruction generated 31 haplotypes. Four of them were associated with dark skin and two had significantly low frequencies in fair skin. One haplotype was associated with green eyes, while two other had aSSOciation with dark brown eyes. Darker hair color was associated with six different haplotypes, whereas red hair was associated with two and blonde hair with one haplotype. Finally, the absence or presence of freckles was significantly related to three haplotypes. Our study shows significant associations between individual SNPs and eyes, hair and skin pigmentation. The results presented here confirm that this gene also plays a relevant role in the pigmentation variation in the Brazilian population.

As abelhas utilizam sinais visuais e olfatórios para encontrar plantas das quais utilizam recursos florais. Algumas abelhas adquiriram hábitos crepuscular ou noturno e forrageiam durante períodos de pouca luminosidade. Algumas espécies de abelhas noturnas são conhecidas por possuírem adaptações morfológicas do sistema visual que lhes permitem o voo noturno, e assim facilitam o encontro de plantas que podem ser utilizadas como recursos. No presente estudo investigamos se espécies crepusculares Megalopta sodalis, Megommation insigne e Ptiloglossa latecalcarata, que utilizam Campomanesia phaea como recurso, e possuem adaptações na morfologia externa do sistema visual. A hipótese principal é que seriam encontrados olhos compostos, omatídeos e ocelos maiores, assim como menor quantidade de omatídeos nos olhos compostos quando comparadas às abelhas diurnas. Para tanto, medimos o comprimento, área e número de omatídeos dos olhos compostos, assim como o diâmetro dos omatídeos e ocelos. A distância intertegular foi medida para ter um controle do tamanho corporal. Além das abelhas crepusculares acima citadas, utilizamos as abelhas diurnas Bombus brasiliensis, Bombus morio, Melipona bicolor e Euglossa cordata para comparação. Para a medida dos olhos fizemos um molde de esmalte e a partir deste obtivemos imagens que foram analisadas utilizando-se o software ImageJ e Matlab. Para as outras medidas, foram obtidas imagens em estereomicroscopio que foram analizadas com o ImageJ. Utilizamos a análise estatística de permutação para ver se havia diferença entre as abelhas crepusculares e diurnas, e correlação de Spearman para ver se a medida estava correlacionada à distância intertegular. Foi realizado um levantamento das espécies com registro de interação com abelhas crepusculares e noturnas e de suas características florais com uma respectiva análise descritiva. As abelhas crepusculares deste estudo possuem o diâmetro dos ocelos e omatídeos maiores e olhos compostos com maior comprimento e área, e menor número de omatídeos. Algumas variáveis estão correlacionadas com a distância intertegular. As flores visitadas por abelhas noturnas possuem em sua maioria cores claras, perfume acentuado e são odoríferas. As abelhas crepusculares deste estudo possuem adaptações na morfologia externa, o que lhes permite o voo no período de pouca luminosidade. Algumas espécies de abelhas que forrageiam em período de pouca luminosidade visitaram flores de cores fortes e uma não odorífera, isso pode estar relacionado à capacidade de reconhecer cores em ambientes pouco iluminados. Algumas espécies de abelhas forrageiam durante o dia e a noite, essa plasticidade do comportamento pode ser um caminho pelo qual caracteres vantajosos para esse ambiente sejam selecionados. Para as plantas, ter as abelhas noturnas como polinizadoras pode ser vantojoso. Então plantas que possuem sinais reconhecidos pelas abelhas noturnas podem se beneficiar com a polinização noturna, evitando o disperdício de pólen com as abelhas diurnas. A maioria das abelhas foi generalista na utlilização do recurso, mas parece haver preferência por certas espécies de plantas / The bees use visual cues and olfactory to find plants which own floral resources. Some bees acquired crepuscular or nocturnal habits and foraging during periods of low light. Some nocturnal bees species are recognized to possess morphological adaptations of the visual system that enable them to practice the night flight, and thus facilitate the matching of plants that can be used as resources. In the present study we investigated whether crepuscular species Megalopta sodalis, Megommation insigne e Ptiloglossa latecalcarata, using Campomanesia phaea as a resource, have adaptations in the external morphology of the visual system. The main hypothesis was that the eyes were composed of ommatidia and larger ocelli as well as lower amount of ommatidia in the compound eyes when compared to daytime bees. Therefore, we measure the length, the area and number of ommatidia of the compound eye and also the diameter of the ommatidia, ocelli, and intertegular distance to have a control of body size. In addition to the crepuscular bees mentioned above, we used the diurnal bees Bombus brasiliensis, Bombus morio, Euglossa cordata, and Melipona bicolor for comparison. For the measurement of eyes, we made a nail polish mold and from this mold was obtained images which were analyzed using ImageJ and Matlab software. For other measures, we obtained images in stereomicroscope that were analyzed only using ImageJ. We use the statistical analysis of permutation to observe if there was any difference between the crepuscular and diurnal bees, and Spearman correlation to see if the measure was correlated with distance intertegular. In addition, we conducted a survey of species interaction with record crepuscular and nocturnal bees and their floral characteristics with a descriptive analisys. The crepuscular bees in this research have lager diameter of omatidea and ocelli, and larger area and length of compound eyes, and less number of omatidea per eye. Most of the flowers visited by nocturnal bees have pale color, scent and nocturnal anthesis. Some bee species that forage in low light visit flowers with strong color, and one bee visited flower without scent, this can be related with capacibility to recoginized colors in environments with low light. Some bees forage during day and night, this phenotypic plasticity of behavior can be a way that advantageous characters for this environment are selected. For plants can be advantageous. Then plants that posses sinals recognized by nocturnal and crepuscular bees can be benefited through nocturnal pollination, avoiding daylight bees waste their polen. The most of bees were generalists in their utilization of flower resource but seems to have preference for some plant species

CoordenaÃÃo de AperfeiÃoamento de Pessoal de NÃvel Superior / Os olhos sem rosto (Georges Franju, 1960) narra a histÃria de Christiane, cujo rosto foi gravemente desfigurado em um acidente de carro provocado pelo prÃprio pai, o mÃdico e professor GÃnessier. Na tentativa de recuperar o rosto da filha, GÃnessier e Louise â sua assistente e tambÃm antiga paciente â sequestram moÃas fisicamente semelhantes a Christiane para, em operaÃÃes ilegais, transplantar a pele do rosto das vÃtimas na jovem e, assim, reestabelecer sua vida. Nosso estudo, em sua segunda parte, parte do filme e de sua temÃtica para discutir a figuraÃÃo do rosto em algumas formas artÃsticas (principalmente no cinema) e a importÃncia dessas figuraÃÃes em nossa sociedade. Em seguida, convocamos autores da antropologia, filosofia, sociologia e literatura (AGAMBEN, 2015; BAKHTIN, 1987; BAQUÃ, 2007; BRETON, 1992, 1998, 2013; COURTINE; HAROCHE, 1988; TUCHERMAN, 2012) para esboÃarmos uma breve trajetÃria antropolÃgica do rosto em dois momentos histÃricos cruciais: a transiÃÃo entre a Idade MÃdia e a Moderna; e a virada do sÃculo XIX para o sÃculo XX. Na terceira parte, nosso objetivo foi traÃar o desenvolvimento do grande plano e das demais formas de enquadrar e figurar o rosto ao longo da histÃria do cinema. Esse percurso foi embasado por teÃricos, crÃticos e cineastas que abordaram o tema (AUMONT, 1992; BALÃZS, 2010; DELEUZE, 1983; EISENSTEIN, 2002; EPSTEIN, 1974). Por fim, Ã realizada a anÃlise de trÃs personagens do filme-objeto a partir de suas (des)apariÃÃes, no intuito de construir uma rede de interpretaÃÃes em torno da materializaÃÃo desses rostos, de suas ligaÃÃes no nÃvel da montagem e de suas relaÃÃes com categorias como a mÃscara, o olhar, o toque e a desfiguraÃÃo. / Eyes without a face (George Franju, 1960) tells the tale of Christiane, whose face was gravely disfigured by a car accident caused by her father, the professor and medical doctor GÃnessier. In an attempt to recover his daughterâs visage, GÃnessier and Louise, his assistant and former patient, start kidnapping young women who resemble Christiane in order to transplant their skin onto the girlâs face and reestablish her normal life. Our present study begins with the analysis of the film and its thematic as a way of reflecting on the figurative emergencies of the face in artistic form and its relevance in contemporary society. We then attempted to establish a dialogue with various authors from the fields of anthropology, philosophy, sociology and literature (AGAMBEN, 2015; BAKHTIN, 1987; BAQUÃ, 2007; BRETON, 1992, 1998, 2013; COURTINE; HAROCHE, 1988; TUCHERMAN, 2012) in order to outline a trajectory of the face in figurative forms. Our concern was particularly in two crucial historical axis, which at certain points overlap: the transition from the medieval depictions to the modern aesthetics; and the turn from the XIX to the XX century. In the third chapter, our goal was to trace the development of the close-up shot and other forms of framing the face throughout movie history, with the aid of theorists, film critics and moviemakers who approached the theme (AUMONT, 1992; BALÃZS, 2010; DELEUZE, 1983; EISENSTEIN, 2002; EPSTEIN, 1974). Finally, the final chapter conducts the analysis of the three main characters of Eyes without a face, with focus in their (dis)appearances in the reel. Our purpose was to construct a net of interpretations around the materialization of these countenances, their links with the general assembly of the movie and their relationships with categories such as mask, gaze, touch and disfiguration.

This paper addresses the collusion with and contradiction to patriarchal power structures of race and femininity in Yamada Eimi's Bedtime Eyes and Trash. In moments of Bedtime Eyes, particularly the final novella "Jesse," and Trash, Yamada contradicts her irresponsible portrayals of Japanese female and black male identity often found in her fiction. This paper will discuss ideological shifts in Yamada's narratives through a textual analysis of Bedtime Eyes and Trash, arguing that through changes in narrative that affect character development, "Jesse" and Trash begin to deconstruct some of the detrimental power structures that shape much Yamada's fictional works.

Thesis (M.Sc. (Optometry)) --University of Limpopo (Turfloop Campus), 2010 / Human Immunodeficiency Virus (HIV) and the associated Acquired Immunodeficiency Syndrome (AIDS) are major public health concerns worldwide and present socioeconomic burden to many governments. To combat this scourge, a deep knowledge about this pandemic is required as one of the preventive methods. Also, the knowledge can serve as a tool to help those who are infected. HIV/AIDS is common among adolescents; therefore, one of the aims of this study is to establish the knowledge of basics of HIV/AIDS among high school learners in the Capricorn district of the Limpopo Province, South Africa.HIV/AIDS also affects the eye; identification of the ocular problem can sometimes help with the diagnosis of HIV/AIDS the condition. Therefore may have both sight and life-saving implications. The school curriculum and HIV/ AIDS awareness campaigns in South Africa do not include basic knowledge of the effects of HIV/AIDS on the eye; therefore an additional aim of this study was to establish the basic knowledge of the effects of HIV/AIDS on the eye among the participants, so that an informed recommendation can be made for the inclusion of the eye component in the awareness campaign and school curriculum. Methodology Following relevant research and ethics approval of the proposal, relevant permissions were obtained before the study commenced. A quantitative survey design was used for the study. Stratified random sampling method was used to select high schools and students that took part in the research. The participants were learners from 18 selected high schools in the Capricorn district of the Limpopo Province. A questionnaire containing demographic data, information on general and ocular effects of HIV/AIDS was used to collect information from the learners, following a pilot study involving 20 high school learners. Data was analyzed with Statistical Packages for Social Sciences (SPSS) computer program version 16. Descriptive statistics (range, mean, standard deviations and frequencies) was used to describe the findings, and analysis of covariance (ANCOVA) model was used to model the scores on each of the dependent variables i.e. general knowledge of HIV/AIDS and basic knowledge of the effects of HIV/AIDS on the eye. Results The participants were 2659 black South African learners in grades 10 to 12 in the high schools. Eighty eight percent were from rural high schools and (12%) were from a semi-urban high school. Their ages ranged from 14 to 28 years with a mean age of 17.82 and SD of ±1.766 years. The participants included (46.4%) males,(53.1%) females, and (0.5%) learners did not indicate their gender.The meaning of the acronym HIV was known by 63.6% of the participants, and these included 65.8% of the females and 61.5% of males. A lesser proportion (61.5%) knew what the acronym AIDS stands for. They included 70.9% of the females and 60.8% of the males. Knowledge about the different modes of HIV transmission varied from 87.0% (transmission through unprotected sex) to 62.5% (transmission from mother-to–child during pregnancy). Regarding the misconception on the modes of HIV/AIDS transmission, a majority (81.5%) of the learners knew that HIV/AIDS could not be transmitted from one person to another through hugging a person infected with HIV; this percentage includes 82.6% of the females and 80.3% of the males.Only two respondents (0.1%) out of the total population knew the meaning of window period in HIV and they were both females. Only about a third (33.2%) knew the difference between HIV positive and negative results. Majority (85.9%) knew that it is important for one to know his or her HIV status. However, only 5.6% knew the reason why people should know their HIV status. Many (60.1%) knew that the manifestation of HIV symptoms can take many years to develop on an HIV infected person, and 54.9% knew that immune system suppression is the first effect of HIV on the body. Knowledge of the effects of HIV on the body during the seroconversion phase (acute phase), varies from 29.9% (HIV can cause continuous nausea) to 73.0% (HIV can cause tiredness). On the facilities that can be used to test for HIV status, knowledge of the participants varied from 93.4% (knew that HIV test can be done at a hospital) to 34.2% (HIV test can be done at the offices of family general medical practitioner). Only a few (27.8%) knew that HIV/ AIDS can affect the eye. Many (65.5%) of the participants knew that an ophthalmologist or an optometrist should be consulted for ocular problems that are related to HIV/AIDS. Knowledge on the effects of HIV on the eye ranges from 20.6% (HIV can cause an itching and burning sensation in the eye) to 58.6% (HIV can cause severe headaches). Forty six percent knew that HIV can cause blindness. Less than half of the participants (46.9%) knew that exchanging contact lenses with the infected person could not transmit HIV from an HIV positive person. Generally the performance was poor on the ocular manifestation of HIV/AIDS. Young learners were more knowledgeable than the older ones, for both general knowledge of HIV/AIDS and knowledge of the effect of HIV/AIDS on the eye (p < 0.05). Gender of the participants was not statistically significant for both components of the survey (p > 0.05). The pattern of performance among the grades across the schools was not consistent for both components of the survey. Also ages of the learners and their grades did not correspond in terms of performance in this study. Conclusion and recommendations General knowledge of HIV/AIDS was fairly good, but the basic knowledge of the effects of HIV/AIDS on the eye was poor. Therefore, to improve the knowledge about HIV/AIDS of the target population people, there is a need for more awareness campaigns in the rural areas of South Africa. Also, it is recommended that basic knowledge of the effects of HIV/AIDS on the eye should be included in the awareness campaigns (e.g. TV, newspapers, radio, magazines, fliers and HIV/AIDS workshops) and should also be integrated into HIV education syllabus as early as primary level. Educators teaching life orientation and life skills should have regular continuing educational programmes to increase their knowledge on the subject of HIV/AIDS and its effects on organs of the body such as the eye. / University of Limpopo

<p>Scallops, a family of swimming bivalve mollusks, have dozens of eyes arrayed along the edges of their valves. Relatively little is known about the form and function of these unusual eyes. To learn more about them, we studied the visually influenced behavior of scallops, as well as the morphology and spectral sensitivity of their eyes. Of particular interest was whether or not the simple neural architecture of these animals constrains the number of visually-influenced behaviors they can perform. We were also interested to learn whether scallop eyes, despite providing relatively poor visual acuity, show optical refinements, such as corrections for spherical and chromatic aberration, that are known from the eyes of animals with better vision. In the following dissertation, Chapter 2 discusses the visually-influenced behaviors of scallops. It has been argued that bivalve mantle eyes only act as predator-detectors, but the behavioral trials described in this chapter suggest that vision may serve additional purposes in scallops. For example, it was found that visual cues relating to flow conditions may influence scallop feeding behavior. Chapter 3 presents a comparative study of scallop eye morphology. Here, it is found that eye morphology varies considerably between scallop species and that highly mobile scallops have better vision than less mobile or immobile species. Evidence is also presented that one of the two scallop retinas may perform tasks of similar importance to all species, such as predator detection, while the other retina may perform tasks more important to mobile species, such as those associated with the visual detection of preferred habitats. Chapter 4 investigates the spectral sensitivity of the two retinas in the mantle eyes of two scallop species. It is found that there is both inter- and intra-specific variation in scallop spectral sensitivity and that color perception in scallops may be influenced by both environmental light conditions and chromatic aberration caused by their lens. The research in this dissertation provides insight into how vision functions in animals that, like scallops, have a vast number of eyes, but a limited capacity for neural processing. Despite such limitations, it is evident that scallops display a wide range of visual behaviors and have eyes with highly-refined optics.</p> / Dissertation

We have realized this work in cooperation with the Laboratory of Ophtalmology, Institute for Biomedical Research, Kaunas Medical University and Department of Anatomy and Physiology, Lithuanian Veterinary Academy. Using A-mode ultrasonography, we investigated structural parameters of the rabbit eye. The intraocular dimensions measured were as follows: distance between the anterior cornea to the anterior lens (CA), Thickness of the lens, distance between the surface of the retina (V), distance from the anterior cornea to the retina, which represents the total axial thickness. We have designed the original investigation methods and ultrasonic equipment with ultrasonic tranducer (f=12 Mhz). Using the acoustodiagnostic system, we were carrying out precise biometry of eye tissues. Ultrasonic investigations were done on 10 eyes of rabbit’s age 12 month. Comparative investigation between rabbits and pigs eye structural elements was done. The percentage relation between total axial length and other ocular dimensions rabbits and pigs eyes was estimated.

Made available in DSpace on 2014-06-11T19:28:57Z (GMT). No. of bitstreams: 0 Previous issue date: 2011-02-04Bitstream added on 2014-06-13T20:58:50Z : No. of bitstreams: 1 moreno_a_me_araca.pdf: 1094331 bytes, checksum: 23ef0f4dabc4bc9f560778bae7c35338 (MD5) / Coordenação de Aperfeiçoamento de Pessoal de Nível Superior (CAPES) / Fundação de Amparo à Pesquisa do Estado de São Paulo (FAPESP) / As próteses oculares são responsáveis pela recuperação da estética e auto-estima do usuário. Assim, os materiais utilizados na confecção de prótese ocular devem possuir propriedades específicas para sua indicação e durabilidade. Desse modo, é importante avaliar o comportamento destes materiais quando influenciados por diversas soluções desinfetantes. Este estudo teve como objetivo avaliar a microdureza, rugosidade superficial e alteração de cor de próteses oculares sobre a influência da desinfecção química e armazenagem. Foram confeccionadas 50 amostras simulando próteses oculares contendo duas resinas acrílicas (N1 e incolor), distribuídas em cinco grupos de acordo com o desinfetante utilizado: sabão neutro (I), opti-free (II), efferdent (III), hipoclorito a 1% (IV) e clorexidina a 4% (V). As amostras foram armazenadas por 120 dias, sendo desinfetadas durante este período. As leituras de microdureza, rugosidade e cor das amostras foram realizadas em um período inicial (B) e após 60 (T1) e 120 (T2) dias de armazenagem com desinfecção. A microdureza foi mensurada por meio de um microdurômetro, e a rugosidade determinada por um rugosímetro. A leitura de cor foi realizada por meio da espectrofotometria de reflexão, usando o sistema CIE L*a*b*. A alteração de cor (ΔE) foi calculada para os períodos entre T1 e B (T1B), e T2 e B (T2B). Pelos resultados obtidos a resina N1 para esclera apresentou menor microdureza estatisticamente significante, comparada a resina incolor (P<0,05). A maior alteração dos valores de microdureza e rugosidade foi obtida para os grupos IV e V. Ambos os períodos de desinfecção e armazenagem produziram alterações significativas (P<0,05) nas amostras com diminuição dos valores de... / Ocular prostheses are responsible to restore not only patient’s aesthetic but also its self-esteem. The materials used to fabricate the ocular prostheses should present specific properties regarding its indication and durability. Therefore, it is important to investigate the physical behavior of such materials when subjected to different disinfectant solutions. This study evaluated the microhardness, surface roughness and color stability of ocular prostheses under the influence of different chemical disinfectant solutions and storage. A total of 50 samples simulating an ocular prosthesis containing two acrylic resins (N1 and colorless) were fabricated. They were divided into five groups as a function of disinfectant solution: neutral soap (I), opti-free (II), efferdent (III), 1% hypochlorite (IV) and 4% chlorhexidine (V). Samples were storage during 120 days, and they were disinfected throughout the period. Microhardness, roughness and color measurements were performed at baseline (B), after 60 (T1) and 120 (T2) days of storage with disinfection. The microharness and the roughness measurements were evaluated using a microdurometer and a roughness meter, respectively. Samples colors were measured with spectrophotometer using CIE L*a*b* system. Color differences (ΔE*) were calculated for periods between T1 and B (T1B), and T2 and B (T2B). The N1 acrylic resin exhibited statistically lower microhardness when compared to the colorless acrylic resin (P<0.05). The highest microhardness and roughness alterations were observed for groups IV and V. Both disinfection and storage periods statistically reduced the microhadness values and increased the roughness values of the samples (P<0.05). Color alteration was... (Complete abstract click electronic access below)

Made available in DSpace on 2014-10-09T12:28:37Z (GMT). No. of bitstreams: 0 / Made available in DSpace on 2014-10-09T13:57:29Z (GMT). No. of bitstreams: 0 / Dissertacao (Mestrado) / IPEN/D / Instituto de Pesquisas Energeticas e Nucleares - IPEN-CNEN/SP