922 resultados para eye-tracker


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Weekly Newsletter from the Northwest District Office for libraries containing programs, activities, classes for the upcoming week.

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Weekly Newsletter from the Northwest District Office for libraries containing programs, activities, classes for the upcoming week.

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Weekly Newsletter from the Northwest District Office for libraries containing programs, activities, classes for the upcoming week.

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Weekly Newsletter from the Northwest District Office for libraries containing programs, activities, classes for the upcoming week.

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Weekly Newsletter from the Northwest District Office for libraries containing programs, activities, classes for the upcoming week.

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Weekly Newsletter from the Northwest District Office for libraries containing programs, activities, classes for the upcoming week.

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Weekly Newsletter from the Northwest District Office for libraries containing programs, activities, classes for the upcoming week.

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Peer reviewed

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Due to the power of genetics, the mouse has become a widely used animal model in vision research. However, its eyeball has an axial length of only about 2 mm. The present protocol describes how to easily dissect the small rodent eye post mortem. This allows collecting different tissues of the eye, i.e., cornea, lens, iris, retina, optic nerve, retinal pigment epithelium (RPE), and sclera. We further describe in detail how to process these eye samples in order to obtain high‐quality RNA for RNA expression profiling studies. Depending on the eye tissue to be analyzed, we present appropriate lysis buffers to prepare total protein lysates for immunoblot and immuno‐precipitation analyses. Fixation, inclusion, embedding, and cryosectioning of the globe for routine histological analyses (HE staining, DAPI staining, immunohistochemistry, in situ hybridization) is further presented. These basic protocols should allow novice investigators to obtain eye tissue samples rapidly for their experiments.

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Image filtering is a highly demanded approach of image enhancement in digital imaging systems design. It is widely used in television and camera design technologies to improve the quality of an output image to avoid various problems such as image blurring problem thatgains importance in design of displays of large sizes and design of digital cameras. This thesis proposes a new image filtering method basedon visual characteristics of human eye such as MTF. In contrast to the traditional filtering methods based on human visual characteristics this thesis takes into account the anisotropy of the human eye vision. The proposed method is based on laboratory measurements of the human eye MTF and takes into account degradation of the image by the latter. This method improves an image in the way it will be degraded by human eye MTF to give perception of the original image quality. This thesis gives a basic understanding of an image filtering approach and the concept of MTF and describes an algorithm to perform an image enhancement based on MTF of human eye. Performed experiments have shown quite good results according to human evaluation. Suggestions to improve the algorithm are also given for the future improvements.

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Purpose: Mediums have been developed to conserve corneal endothelium in organ-culture during eye banking. CorneaMax® is used by 25% of Eye Bank in Europe. Only little is known about conservation of corneal epithelium with this medium during banking. Its preservation could be of interest in clinic to cure corneal disease with stem cells deficiency. Therefore, we wanted to examine the integrity of human corneal epithelium maintained in CorneaMax®. Methods: Human corneas, considered unsuitable for transplantation, were obtained from the Eye Bank in Lausanne. Average post-mortem time was 14 hours. Cornoscleral rings were maintained in organ-culture in Corneamax® at 32°C. Samples were formalin-fixed after period ranging from 0 (D0) to 35 days (D35, N=5 for each time points) and stained with H&E. Proliferation and apoptosis were evaluated by immunostaining with antibody against Ki67 and Caspase3 respectively. Results: Corneas, which were not in organ-cultured (D0), showed different morphology, including intact epithelium with 5 to 7 layers, but also completely denuded basement membrane. In two cases, at D0, the epithelium lost its adherence to the basal lamina of the cornea creating a large epithelial sheet. During the two first days, corneas and limbus area lost totally their epithelium, except for some remaining limbal basal cells. From day 2 to day 10, regeneration of the epithelium took place, starting from the limbal region in direction to the central cornea. From day 10 to day 35, corneal epithelium appeared as an atrophic epithelium, consisting of only two cell layers. Proliferation happened in the whole cornea during the 35 days of organ-culture, as shown by Ki67 positive cells. Apoptosis was rarely detected in the corneal epithelium. Conclusions: Corneas maintained in CorneaMax® showed a complete disappearance of the corneal epithelium during the two first days and a conservation of limbal basal cells in the limbal region. These remaining cells allowed a full regeneration of the tissue, leading to an atrophic epithelium, composed of only two cell layers. This atrophic epithelium could be seen in all the organ-cultured corneas during the 35 days of conservation. This study is a first step to develop medium in organ-culture in order to conserve corneal epithelial cells.

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PURPOSE: Drug delivery to treat diseases of the posterior segment of the eye, such as choroidal neovascularization and its complications, is hampered by poor intraocular penetration and rapid elimination of the drug from the eye. The purpose of this study was to investigate the feasibility and tolerance of suprachoroidal injections of poly(ortho ester) (POE), a bioerodible and biocompatible polymer, as a biomaterial potentially useful for development of sustained drug delivery systems. METHODS: After tunnelization of the sclera, different formulations based on POE were injected (100 microL) into the suprachoroidal space of pigmented rabbits and compared with 1% sodium hyaluronate. Follow-up consisted of fundus observations, echography, fluorescein angiography, and histologic analysis over 3 weeks. RESULTS: After injection, POE spread in the suprachoroidal space at the posterior pole. It was well tolerated and progressively disappeared from the site of injection without sequelae. No bleeding or retinal detachment occurred. Echographic pictures showed that the material was present in the suprachoroidal space for 3 weeks. Angiography revealed minor pigment irregularities at the site of injection, but no retinal edema or necrosis. Histology showed that POE was well tolerated in the choroid. CONCLUSIONS: POE suprachoroidal injections, an easy, controllable, and reproducible procedure, were well tolerated in the rabbit eye. POE appears to be a promising biomaterial to deliver drugs focally to the choroid and the retina.

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Evaluar una arquitectura de la información en un sitio web ya desplegado no resulta una tarea sencilla. La mayoría de las técnicas se centran en examinar la usabilidad del sistema que, aunque afecta a la arquitectura de la información, no es el único factor que influye en ella. La principal técnica que se utiliza es el test de estrés de navegación. Se muestra un aporte metodológico para hacer dicha técnica más informativa, llevándola más allá de la simple anotación en papel por parte del usuario de respuestas a las preguntas de navegación planteadas. Se propone la combinación de ésta con otras técnicas de evaluación de la usabilidad: la técnica de pensar en voz alta o thinking aloud y un cuestionario de usabilidad. Se ha utilizado un sistema de seguimiento de la mirada o eye tracking para complementar la información obtenida mediante las técnicas aplicadas. El enfoque metodológico planteado se ha puesto a prueba analizando una serie de sitios web de bibliotecas de universidades públicas españolas. Se muestra en los resultados la validez del enfoque empleado, así como el valor que dicho enfoque y el uso del eye tracking aportan al análisis de la arquitectura de la información respecto al test de estrés de navegación tradicional.