609 resultados para PUPIL
Resumo:
A percepção de presença (PP), evolução do conceito de telepresença, pode ser definida como ilusão perceptiva de não mediação e/ou a percepção ilusória da realidade. O método mais utilizado para a avaliação da PP faz uso de questionários aplicados aos sujeitos, após sua participação numa experiência. Além de não fornecer informações em tempo real esse método sofre muitas interferências advindas tanto dos sujeitos submetidos ao experimento como dos avaliadores dos questionários. Os métodos que poderiam ser mais efetivos para a avaliação da PP, em tempo real, fazem uso de sinais fisiológicos que variam independentemente da vontade dos sujeitos, como batimento cardíaco, eletrocardiograma, eletroencefalograma, resistividade e umidade da pele. Os sinais fisiológicos, no entanto, só variam de forma significativa em situações de estresse, inviabilizando sua utilização em atividades normais, sem estresse. Outra forma de avaliar a PP é utilizar sistemas de rastreamento do olhar. Estudados e desenvolvidos desde o século 19, os sistemas de rastreamento do olhar fornecem um mapeamento do movimento dos olhos. Além de indicar para onde os sujeitos estão olhando, podem também monitorar a dilatação da pupila e as piscadas. Atualmente existem sistemas de rastreamento do olhar comerciais de baixo custo, que apesar de terem menos precisão e frequência que os equipamentos de alto custo são mais práticos e possuem software de plataforma aberta. No futuro serão tão comuns e simples de usar como são hoje as câmeras em dispositivos móveis e computadores, o que viabilizará a aplicação das técnicas e métodos aqui propostos em larga escala, principalmente para monitorar a atenção e envolvimento de atividades mediadas por vídeo. É apresentada uma ferramenta que faz uso do rastreamento do olhar para avaliar a percepção de presença em atividades mediadas por vídeo (com estímulos sonoros). Dois experimentos foram realizados para validar as hipóteses da pesquisa e a ferramenta. Um terceiro experimento foi executado para verificar a capacidade da ferramenta em avaliar a percepção de presença em atividades não estressantes mediadas por vídeo.
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Esta investigación, enmarcada dentro del movimiento sobre Eficacia de la Escuela, realiza una explotación parcial de los datos PISA 2003, para el territorio español, obtenidos en la investigación llevada a cabo por la OCDE. El alumnado español que ha participado en el estudio PISA, supone un total de 10.791 estudiantes de 383 centros de Educación Secundaría pertenecientes a varias Comunidades Autónomas. Las variables predictoras que forman parte de la investigación se obtienen de alumno y del centro. La variable de respuesta, desde un enfoque criterial, establece información sobre el nivel de competencias alcanzado por el alumno en matemáticas. Los resultados del análisis multinivel proporcionan diferentes modelos que tratan de explicar la variabilidad observada entre los centros a través de la incorporación de sus variables. El modelo resultante reconoce que las variables de centro: titularidad, porcentaje de alumnas, fomento de actividades matemáticas y compromiso y moral del alumnado se relacionan con el rendimiento en matemáticas.
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Purpose To evaluate visual, optical, and quality of life (QoL) outcomes and intercorrelations after bilateral implantation of posterior chamber phakic intraocular lenses. Methods Twenty eyes with high to moderate myopia of 10 patients that underwent PRL implantation (Phakic Refractive Lens, Carl Zeiss Meditec AG) were examined. Refraction, visual acuity, photopic and low mesopic contrast sensitivity (CS) with and without glare, ocular aberrations, as well as QoL outcomes (National Eye Institute Refractive Error Quality of Life Instrument-42, NEI RQL-42) were evaluated at 12 months postoperatively. Results Significant improvement in uncorrected (UDVA) and best-corrected distance (CDVA) visual acuities were found postoperatively (p < 0.01), with significant reduction in spherical equivalent (p < 0.01). Low mesopic CS without glare was significantly better than measurements with glare for 1.5, 3, and 6 cycles/degree (p < 0.01). No significant correlations between higher order root mean square (RMS) with CDVA (r = −0.26, p = 0.27) and CS (r ≤ 0.45, p ≥ 0.05) were found. Postoperative binocular photopic CS for 12 cycles/degree and 18 cycles/degree correlated significantly with several RQL-42 scales. Glare index correlated significantly with CS measures and scotopic pupil size (r = −0.551, p = 0.04), but not with higher order RMS (r = −0.02, p = 0.94). Postoperative higher order RMS, postoperative primary coma and postoperative spherical aberration was significant higher for 5-mm pupil diameter (p < 0.01) compared with controls. Conclusions Correction of moderate to high myopia by means of PRL implantation had a positive impact on CS and QoL. The aberrometric increase induced by the surgery does not seem to limit CS and QoL. However, perception of glare is still a relevant disturbance in some cases possibly related to the limitation of the optical zone of the PRL.
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Background To evaluate the intraocular lens (IOL) position by analyzing the postoperative axis of internal astigmatism as well as the higher-order aberration (HOA) profile after cataract surgery following the implantation of a diffractive multifocal toric IOL. Methods Prospective study including 51 eyes with corneal astigmatism of 1.25D or higher of 29 patients with ages ranging between 20 and 61 years old. All cases underwent uneventful cataract surgery with implantation of the AT LISA 909 M toric IOL (Zeiss). Visual, refractive and corneal topograpy changes were evaluated during a 12-month follow-up. In addition, the axis of internal astigmatism as well as ocular, corneal, and internal HOA (5-mm pupil) were evaluated postoperatively by means of an integrated aberrometer (OPD Scan II, Nidek). Results A significant improvement in uncorrected distance and near visual acuities (p < 0.01) was found, which was consistent with a significant correction of manifest astigmatism (p < 0.01). No significant changes were observed in corneal astigmatism (p = 0.32). With regard to IOL alignment, the difference between the axes of postoperative internal and preoperative corneal astigmatisms was close to perpendicularity (12 months, 87.16° ± 7.14), without significant changes during the first 6 months (p ≥ 0.46). Small but significant changes were detected afterwards (p = 0.01). Additionally, this angular difference correlated with the postoperative magnitude of manifest cylinder (r = 0.31, p = 0.03). Minimal contribution of intraocular optics to the global magnitude of HOA was observed. Conclusions The diffractive multifocal toric IOL evaluated is able to provide a predictable astigmatic correction with apparent excellent levels of optical quality during the first year after implantation.
Resumo:
Implantation of phakic intraocular lenses (pIOLs) is a reversible refractive procedure, preserving the patient’s accommodative function with minimal induction of higher order aberrations compared with corneal photoablative procedures. Despite this, as an intraocular procedure, it has potential risks such as cataracts, chronic uveitis, pupil ovalization, corneal endothelial cell loss, pigmentary dispersion syndrome, pupillary block glaucoma, astigmatism, or endophthalmitis. Currently, only two models of posterior chamber pIOLs are commercially available, the implantable collammer lens (STAAR Surgical Co.) and the phakic refractive lens (PRL; Zeiss Meditec). The number of published reports on the latter is very low, and some concerns still remain about its long-term safety. The present article reviews the published literature on the outcomes after PRL implantation in order to provide a general overview and evaluate its real potential as a surgical refractive option.
Reverse Geometry Hybrid Contact Lens Fitting in a Case of Donor-Host Misalignment after Keratoplasty
Resumo:
Purpose: To report the successful outcome obtained after fitting a new hybrid contact lens in a cornea with an area of donor-host misalignment and significant levels of irregular astigmatism after penetrating keratoplasty (PKP). Materials and methods: A 41-year-old female with bilateral asymmetric keratoconus underwent PKP in her left eye due to the advanced status of the disease. One year after surgery, the patient referred a poor visual acuity and quality in this eye. The fitting of different types of rigid gas permeable contact lenses was performed, but with an unsuccessful outcome due to contact lens stability problems and uncomfortable wear. Scheimpflug imaging evaluation revealed that a donor-host misalignment was present at the nasal area. Contact lens fitting with a reverse geometry hybrid contact lens (Clearkone, SynergEyes Carlsbad) was then fitted. Visual, refractive, and ocular aberrometric outcomes were evaluated during a 1-year period after the fitting. Results: Uncorrected distance visual acuity improved from a prefitting value of 20/200 to a best corrected postfitting value of 20/20. Prefitting manifest refraction was +5.00 sphere and -5.50 cylinder at 75°, with a corrected distance visual acuity of 20/30. Higher order root mean square (RMS) for a 5 mm pupil changed from a prefitting value of 6.83 µm to a postfitting value of 1.57 µm (5 mm pupil). The contact lens wearing was referred as comfortable, with no anterior segment alterations. Conclusion: The SynergEyes Clearkone contact lens seems to be another potentially useful option for the visual rehabilitation after PKP, especially in cases of donor-host misalignment.
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Corneal and anterior segment imaging techniques have become a crucial tool in the clinical practice of ophthalmology, with a great variety of applications, such as corneal curvature and pachymetric analysis, detection of ectatic corneal conditions, anatomical study of the anterior segment prior to phakic intraocular lens implantation, or densitometric analysis of the crystalline lens. From the Placido-based systems that allow only a characterization of the geometry of the anterior corneal surface to the Scheimpflug photography-based systems that provide a characterization of the cornea, anterior chamber, and crystalline lens, there is a great variety of devices with the capability of analyzing different anatomical parameters with very high precision. To date, Scheimpflug photography-based systems are the devices providing the more complete analysis of the anterior segment in a non-invasive way. More developments are required in anterior segment imaging technologies in order to improve the analysis of the crystalline lens structure as well as the ocular structures behind the iris in a non-invasive way when the pupil is not dilated.
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Background: The pupillary light reflex characterizes the direct and consensual response of the eye to the perceived brightness of a stimulus. It has been used as indicator of both neurological and optic nerve pathologies. As with other eye reflexes, this reflex constitutes an almost instantaneous movement and is linked to activation of the same midbrain area. The latency of the pupillary light reflex is around 200 ms, although the literature also indicates that the fastest eye reflexes last 20 ms. Therefore, a system with sufficiently high spatial and temporal resolutions is required for accurate assessment. In this study, we analyzed the pupillary light reflex to determine whether any small discrepancy exists between the direct and consensual responses, and to ascertain whether any other eye reflex occurs before the pupillary light reflex. Methods: We constructed a binocular video-oculography system two high-speed cameras that simultaneously focused on both eyes. This was then employed to assess the direct and consensual responses of each eye using our own algorithm based on Circular Hough Transform to detect and track the pupil. Time parameters describing the pupillary light reflex were obtained from the radius time-variation. Eight healthy subjects (4 women, 4 men, aged 24–45) participated in this experiment. Results: Our system, which has a resolution of 15 microns and 4 ms, obtained time parameters describing the pupillary light reflex that were similar to those reported in previous studies, with no significant differences between direct and consensual reflexes. Moreover, it revealed an incomplete reflex blink and an upward eye movement at around 100 ms that may correspond to Bell’s phenomenon. Conclusions: Direct and consensual pupillary responses do not any significant temporal differences. The system and method described here could prove useful for further assessment of pupillary and blink reflexes. The resolution obtained revealed the existence reported here of an early incomplete blink and an upward eye movement.
Resumo:
Purpose: To report a very successful outcome obtained with the fitting of a new-generation hybrid contact lens of reverse geometry in a thin cornea with extreme irregularity due to the presence of a central island after unsuccessful myopic excimer laser refractive surgery. Methods: A 32-year-old man attended to our clinic complaining of very poor vision in his right eye after bilateral laser in situ keratomileusis (treatment or surgery) for myopia correction and some additional retreatments afterward. After a comprehensive ocular evaluation, contact lens fitting with a reverse geometry hybrid contact lens (SynergEyes PS, SynergEyes, Carlsbad, CA) was proposed as a solution for this case. Visual, refractive, and ocular aberrometric outcomes with the contact lens were evaluated. Results: Distance visual acuity improved from a prefitting uncorrected value of 20/200 to a postfitting corrected value of 20/16. Prefitting manifest refraction was +6.00 sphere and −3.00 cylinder at 70°, with a corrected distance visual acuity of 20/40. Higher order root mean square for a 5-mm pupil changed from a prefitting value of 1.45 to 0.34 µm with the contact lens. The contact lens wearing was reported as comfortable, and the patient was very satisfied with this solution. Conclusions: The SynergEyes PS contact lens seems to be an excellent option for the visual rehabilitation of corneas with extreme irregularity after myopic excimer laser surgery, minimizing the level of higher order aberrations and providing an excellent visual outcome.
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In this article I study the Preface by Ferran Valentí to his own translation into Catalan of Cicero’s Paradoxa. Ferran Valentí was a humanist from Majorca, author in Catalan language who earned a Low Degree at the University of Bologna and who declared himself a devoted “son and pupil” of humanist Leonardo Bruni. Valentí made an analysis of the humanistic Canon in mid-15th century, including troubadours, Dante, Lullius, Latin literature classics and several Catalan authors, such as Bernat Metge. This proves that humanism was a true trend in the Crown of Aragon from the 2nd half of the 14th Century on.
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The implantation of the new Architecture Degree and the important normative changes in the building sector imply the need to use new teaching methodologies that enhance skills and competences in order to response to the increasing requirements demanded by society to the future architect. The aim of this paper is to present, analyze and discuss the development of multidisciplinary workshops as a new teaching methodology used in several Construction subjects of the Architecture Degree in the University of Alicante. Workshops conceived with the aim to synthesize and complement the technical knowledge acquired by the students during the Degree and to enhance the skills and competencies necessary for the professional practice. With that purpose, we decided to experiment on current subjects of the degree during this academic year, by applying the requirements defined in the future Architecture Degree in a practical way, through workshops between different subjects, superposing the technical knowledge with the resolution of constructive problems in the development of an architectural project. Developing these workshops between subjects we can dissolve the traditional boundaries between different areas of the Degree. This multidisciplinary workshop methodology allows the use of all the global knowledge acquired by students during their studies and at the same time, it enhances students’ ability to communicate and discuss their ideas and solutions in public. It also increases their capacity of self-criticism, and it foments their ability to undertake learning strategies and research in an autonomous way. The used methodology is based on the development of a practical work common to several subjects of different knowledge areas within the "Technology Block" of the future Architecture Degree. Thus, students work approaching the problem in a global way discussing simultaneously with teachers from different areas. By using these new workshops we stimulate an interactive class versus a traditional lecture. Work is evaluated continuously, valuing the participative pupil´s attitude, working in groups in class time, reaching weekly objectives and stimulating the individual responsibility and positive interdependence of the pupil inside the working group. The exercises are designed to improve students’ ability to transmit their ideas and solutions in public, knowing how to discuss and defend their technical resolutions to peers and teachers (Peer Reviewing), their capacity for self-criticism and their capacity to undertake strategies and autonomous learning processes at the same time they develop a personal research into new technologies, systems and materials. Students have shown their majority preference for this teaching methodology by the multidisciplinary workshops offered in the last years, with very satisfactory academic results. In conclusion, it can be verified nowadays the viability of the introduction of new contents and new teaching methodologies necessary for the acquisition of the skills in the future Architecture Degree, through workshops between several subjects that have had a great acceptance in students and positive contrasted academic results.
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The aim of this article is to compare the Suzuki and BAPNE methods based on bibliography published for both approaches. In the field of musical and instrumental education and especially for the childhood stage, the correct use of the body and voice are of fundamental importance. These two methods differ from one another; one principally musical and instrumental, which is the Suzuki method, and one non-musical, the BAPNE method, which aims at stimulating attention, concentration, memory and the executing function of the pupil through music and body percussion. Comparing different approaches may provide teachers with a useful insight for facing different issues related to their discipline.
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Two leaves containing a two-page handwritten letter from Peck to Bentley identifying and describing the fish species Ophidium as the specimen in a drawing by a young woman described by Peck alternately as Bentley's "daughter" and "Miss C." Bentley had no children, and Peck is presumably referring to Hannah Crowninshield, Bentley's pupil.
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This is the second of three volumes which comprise Khvandemīr's well known and important general history, completed in 929/1523, which spans the creation of the world up to the death of Shah Ismāʻīl Safavī I. The work includes particularly detailed information about Herat under Sultan Husayn Bayqara, the last Timurid ruler in Herat, as well as Shah Ismāʻīl and Bābur's life. This work has been published in both Persian and English editions.
Resumo:
Orchestral acc. arr. for piano.