Exploring the optimum step size for defocus curves

Purpose: To evaluate the effect of reducing the number of visual acuity measurements made in a defocus curve on the quality of data quantified. Setting: Midland Eye, Solihull, United Kingdom. Design: Evaluation of a technique. Methods: Defocus curves were constructed by measuring visual acuity on a distance logMAR letter chart, randomizing the test letters between lens presentations. The lens powers evaluated ranged between +1.50 diopters (D) and -5.00 D in 0.50 D steps, which were also presented in a randomized order. Defocus curves were measured binocularly with the Tecnis diffractive, Rezoom refractive, Lentis rotationally asymmetric segmented (+3.00 D addition [add]), and Finevision trifocal multifocal intraocular lenses (IOLs) implanted bilaterally, and also for the diffractive IOL and refractive or rotationally asymmetric segmented (+3.00 D and +1.50 D adds) multifocal IOLs implanted contralaterally. Relative and absolute range of clear-focus metrics and area metrics were calculated for curves fitted using 0.50 D, 1.00 D, and 1.50 D steps and a near add-specific profile (ie, distance, half the near add, and the full near-add powers). Results: A significant difference in simulated results was found in at least 1 of the relative or absolute range of clear-focus or area metrics for each of the multifocal designs examined when the defocus-curve step size was increased (P<.05). Conclusion: Faster methods of capturing defocus curves from multifocal IOL designs appear to distort the metric results and are therefore not valid. Financial Disclosure: No author has a financial or proprietary interest in any material or method mentioned. © 2013 ASCRS and ESCRS.

The time course of changes in retinal vessel diameter in response to differing durations of flicker light provocation

Purpose: To determine the response of retinal vessels to differing durations of flicker light (FL) sitmulation. Methods: We recorded retinal arterial and venous vessel dilation to 12.5 Hz flicker light provocation (Retinal Vessel Analyzer, Imedos Systems) of varying duration (5, 7, 10 and 20 seconds) in twelve healthy young individuals (age range 26-45 yrs). All participants underwent a full ocular examination including intraocular pressure and blood pressure measurements. Results: Maximum dilation (MD) did not show a significant dependence on flicker duration in arteries whereas maximum constriction (MC) did. However, in veins MD significantly increased with flicker duration. Approximately 80-90% of MD in arteries is reached within 10 seconds of flicker light stimulation. Conclusions: The vast majority of arterial dilatory capacity is reached within 10 seconds of flicker light stimulation even though venous dilation continues strongly. Since the MC of arteries shows a significant dependence on flicker duration measurements at two different durations can provide more information about the retinal vascular system than at a single flicker duration alone.

Um sistema inteligente de teleoftalmologia para o auxílio no diagnóstico de catarata

The increasing in world population, with higher proportion of elderly, leads to an increase in the number of individuals with vision loss and cataracts are one of the leading causes of blindness worldwide. Cataract is an eye disease that is the partial or total opacity of the crystalline lens (natural lens of the eye) or its capsule. It can be triggered by several factors such as trauma, age, diabetes mellitus, and medications, among others. It is known that the attendance by ophthalmologists in rural and poor areas in Brazil is less than needed and many patients with treatable diseases such as cataracts are undiagnosed and therefore untreated. In this context, this project presents the development of OPTICA, a system of teleophthalmology using smartphones for ophthalmic emergencies detection, providing a diagnostic aid for cataract using specialists systems and image processing techniques. The images are captured by a cellphone camera and along with a questionnaire filled with patient information are transmitted securely via the platform Mobile SANA to a online server that has an intelligent system available to assist in the diagnosis of cataract and provides ophthalmologists who analyze the information and write back the patient’s report. Thus, the OPTICA provides eye care to the poorest and least favored population, improving the screening of critically ill patients and increasing access to diagnosis and treatment.

Manifestações oculares em mulheres com síndrome dos ovários policísticos: prevalência e associação com fatores de risco metabólicos e inflamatórios

Objetivos: Estimar a prevalência de alterações do filme lacrimal e da doença do olho seco (DOS), comparar as mudanças na pressão intraocular (PIO) e comparar as espessuras macular e da camada de fibras nervosas da retina (CFNR), entre mulheres com síndrome dos ovários policísticos (SOP) e mulheres saudáveis, estratificando-as em condições clínicas, metabólicas e inflamatórias. Metodologia: O estudo incluiu 45 mulheres com SOP e 47 mulheres saudáveis ovulatórias submetidas a avaliações clínico-ginecológicas e oftalmológicas, incluindo propedêuticas para a avaliação do filme lacrimal e medida da PIO, e medição da espessura macular, da CFNR e parâmetros do disco óptico usando tomografia de coerência óptica. Resultados: Tempo de ruptura do filme lacrimal (TRFL; p=0.001) e impregnação por fluoresceína (p=0.006) apresentaram diferenças estatisticamente significantes entre os grupos estudados. A prevalência de DOS foi de 44,4% nas portadoras de SOP. Houve redução estatisticamente significativa do TRFL na presença de SOP (p=0.001). Além disso, houve efeito estatisticamente significativo de intolerância à glicose e síndrome metabólica/inflamação na impregnação por fluoresceina (p=0.004; p=0.015, respectivamente). A PIO encontrou-se estatisticamente mais elevada no grupo SOP que no grupo controle (p=0.011). Houve um aumento na média do IPC (índice pressão-córnea) com a associação entre SOP e da síndrome metabólica (p = 0.005); A média da espessura da CNFR superior ao redor do nervo óptico foi estatisticamente mais espessa nas voluntárias com SOP que nas voluntárias saudáveis (p=0.036); Após estratificação pela presença de resistência insulínica, as médias dos subcampos das espessuras maculares “macular interno temporal, macular interno inferior, macular interno nasal e macular externo nasal, foram mais espessas no grupo SOP que no grupo controle (p<0.05); Houve associação significativa entre obesidade e resistência insulínica (p=0.037), e intolerância à glicose (p=0.001), com aumento médio do componente principal 1 (CP1), e, na presença de síndrome metabólica (p<0.0001), com aumento médio do componente principal 2 (CP2), respectivamente, em relação à espessura macular total. Na presença de obesidade e inflamação, houve redução no escore médio da CP2 (p=0.034), em relação à espessura da CFNR na mácula. xviii Conclusões: Há uma associação da SOP, suas alterações metabólicas e inflamatórias com alterações do filme lacrimal e com mudanças na PIO. A diminuição na espessura da CFNR macular e aumento da espessura total macular estão possivelmente associadas às alterações metabólicas, e, o aumento na espessura da CFNR ao redor do nervo óptico estão provavelmente associadas às alterações hormonais, inerentes à SOP.

Identidades coletivas de estudiosos da linguagem no currículo lattes: docência, pertença social e capital cultural-acadêmico

The discussion involving the identity of social actors has taken place for some years, however, it has become significant for the discourse studies over the last years due to the fragmentation of postmodern actors. Understanding the identity as a symbolic concept that can aid in the detection of certain realities - a kind of mechanism / a magnifying glass (MERLUCCI, 1985) - you can check the linguistic materiality of the introductory text of the lattes resume as a adequate place for the formation of collective identities . The aim of this dissertation is to reflect, in a time of postmodernity, through the lattes introductory curriculum texts, the collective identities of the language researchers are portrayed in discursive and social practices based on the accumulation of cultural and academic capital. For analysis, surrounding the indisciplinary posture in Applied Linguistics (MOITA-LOPES, 2006), the descriptive / interpretive methodology was used (MAGALHÃES, 2001). Whereas the study method and the social theory, as state reasons of the research makes use of the Sociological Approach and Communicational Discourse, chain linked to the assumptions of Critical Discourse Analysis (PEDROSA, 2012a). The corpus is constituted of twenty-seven introductory texts from the lattes curriculum of language researchers, connected to three institutions of higher learning in Sergipe. After the collection, on the lattes platform, and the numbering of the curriculum in order to achieve the research objective, we performed the analysis based on three identity themes: teaching, social belonging (BAJOIT, 2006; DESCHAMPS; MOLINER, 2009) and the accumulation of academic-cultural capital (BOURDIEU, 2004; HEY, 2008). The data show that the texts of the lattes curriculum are based on hegemonic and ideological principals, referring to the accumulation of academic assets, the valuation of actors and the hierarchical positions, recognized and ratified by couples who socialize among themselves Right now, the research allows us to infer that, in postmodernity, some collective identity assumptions, contribute to the understanding of the academic reality, around the the lattes curriculum.

Capacidades estatais para implementação de políticas públicas em ambientes federativos: o caso do Programa Bolsa Família

This thesis aims to understand the extent to which state capacities of state governments explain the effectiveness of the implementation of Programa Bolsa Família (PBF) in the Northeast, adopting the implementation of the theory as the main theoretical lens and more specifically the concept of state capacity. Methodologically is a study of public policy evaluation, and categorized as a process of evaluation study or implementation. Given the specificity of the object is classified as a multi case study research covering the states of Sergipe, Rio Grande do Norte and Bahia. In addition to using secondary data, the study used semi-structured interviews with members of Intersectoral Committees responsible for the actions of PBF and the Cadastro Único at the state level, composed of representatives of the areas of the state government of Social Welfare, Education and Health. the main findings related to technical and administrative capacities and policies were found: infrastructure with weakness in human resources, technological and financial resources; intra-governmental coordination with boundaries between PBF and Unified Social Assistance System , and the actions of conditionality of health and Health Unic System Basic Attention; intergovernmental coordination carried out mostly by the distance limitations of displacement and incipient regional decentralization of actions; based monitoring in the municipalities of lower performance and from the parameters placed by the federal government and political capacities; representative political system is hardly accessed by instances of program management; minor social participation and low articulation with related issues advice to PBF; audit control by any outside agencies. The thesis concludes that depending on the capabilities found implementing weaknesses are not unique to the program's actions, but from the very institutional capacity of the systems in which it operates that are the Unified Social Assistance System, the Health Unic System and the Educational System. In other words limitations of their own state capacities of the state governments and the municipal governments of each territory, such as quantitative insufficiency and qualification of human resources, financial and institutional resources, lack instance promoting decentralization (Intergovernmental and intra-governmental) as well the weakness or absence of a network of local social services are also factors that explain the program management performance and state capabilities of arrangements formed by states and municipalities in the PBF, only to partially deal with the complexity of joints involving Implementation of the program with regard to inter and intra-governmental action.

Capacidades estatais para implementação de políticas públicas em ambientes federativos: o caso do Programa Bolsa Família

This thesis aims to understand the extent to which state capacities of state governments explain the effectiveness of the implementation of Programa Bolsa Família (PBF) in the Northeast, adopting the implementation of the theory as the main theoretical lens and more specifically the concept of state capacity. Methodologically is a study of public policy evaluation, and categorized as a process of evaluation study or implementation. Given the specificity of the object is classified as a multi case study research covering the states of Sergipe, Rio Grande do Norte and Bahia. In addition to using secondary data, the study used semi-structured interviews with members of Intersectoral Committees responsible for the actions of PBF and the Cadastro Único at the state level, composed of representatives of the areas of the state government of Social Welfare, Education and Health. the main findings related to technical and administrative capacities and policies were found: infrastructure with weakness in human resources, technological and financial resources; intra-governmental coordination with boundaries between PBF and Unified Social Assistance System , and the actions of conditionality of health and Health Unic System Basic Attention; intergovernmental coordination carried out mostly by the distance limitations of displacement and incipient regional decentralization of actions; based monitoring in the municipalities of lower performance and from the parameters placed by the federal government and political capacities; representative political system is hardly accessed by instances of program management; minor social participation and low articulation with related issues advice to PBF; audit control by any outside agencies. The thesis concludes that depending on the capabilities found implementing weaknesses are not unique to the program's actions, but from the very institutional capacity of the systems in which it operates that are the Unified Social Assistance System, the Health Unic System and the Educational System. In other words limitations of their own state capacities of the state governments and the municipal governments of each territory, such as quantitative insufficiency and qualification of human resources, financial and institutional resources, lack instance promoting decentralization (Intergovernmental and intra-governmental) as well the weakness or absence of a network of local social services are also factors that explain the program management performance and state capabilities of arrangements formed by states and municipalities in the PBF, only to partially deal with the complexity of joints involving Implementation of the program with regard to inter and intra-governmental action.

Múltiplos fluxos ópticos e o processamento atentivo da informação visual

The environment in which we live in, we constantly deal with a huge amount of dynamic information, thus, attention is an indispensable cognitive resource that allows an effective selection of stimuli for our survival. From this, investigating how we process our encouragement in movements and how the attention spreads into a space to serve more than one stimuli simultanously is something very important. The behavioural urgence hipothesis suggests that the encouragement in a movement of approaching shows a certain priority in the process related to objects which are in a movement away, but there are researches that point out that it might not happen in an attentive phase, but instead as a priorization of motor response. There are also many controversies found in researches about attentive focalization, in which some studies suggest that the focus of attention would work in a similar manner to a zoom lens, while some searches indicate that the focus of attention could be shared to answer some stimuli in non contiguous regions. This study tried to investigate through two experiments the effect of attentive priorization by encouragement in movements and how the attention is spread with distractors stimuli. The first experiment investigated if the amount of moving flows really influenced in the process of information. The results indicate an effect of priorization of the flows guided in relation to aleatory ones and also from the unique flow due to dual flow. The second experiment investigated how the distribution of attention is in a space with the use of flows as an exogenous cue. The results indicate that the focus of attention works as the one suggested in the zoom lens model.

Papel biológico del diadenosin tetrafosfato en el ojo: efecto sobre la composición lacrimal e implicación en la función de barrera corneal

El Ap4A es una molécula con un amplio papel biológico en el ojo. Se ha descrito su implicación en procesos de secreción lagrimal, cicatrización epitelial, regulación de la presión intraocular, y presenta también un papel neuroprotector sobre los terminales simpáticos que inervan el cuerpo ciliar. El objetivo de este trabajo ha sido analizar la participación del Ap4A en otras posibles funciones a nivel ocular. En concreto se ha estudiado la capacidad de este dinucléotido para estimular la liberación de proteínas lagrimales de acción antibacteriana tales como la lisozima y la lactoferrina. Por otra parte se ha investigado su efecto como modulador de la función de barrera de la córnea a través de la regulación de los niveles de expresión de proteínas constituyentes de las tight junctions (TJ). Dicho efecto sobre la barrera puede tener una importante repercusión en la entrada de fármacos y en la consiguiente eficacia terapéutica de los mismos. Por último, se ha estudiado la posible implicación del dinucleótido en el proceso de edematización descrito en modelos animales glaucomatosos tales como el ratón DBA/2J. Con el objetivo de averiguar si la activación de Ap4A inducía un efecto sobre la producción de dos proteínas antimicrobianas relevantes de la lágrima (lisozima y lactoferrina) se realizaron ensayos en la lágrima de conejos albinos de Nueva Zelanda, mediante las técnicas de agar-agar y ELISA. Los resultados obtenidos demostraron que Ap4A produce un aumento en la concentración de lisozima y de lactoferrina del 93% y 24%, respectivamente, frente a valores basales, y este efecto está mediado por receptores de tipo P2...

Caracterización de un modelo murino de glaucoma: implicación funcional de la señalización del receptor P2X7 en procesos neurodegenerativos de la retina

El glaucoma es una de las causas más comunes de discapacidad visual y una de las enfermedades neurodegenerativas oculares más frecuentes de pérdida irreversible de visión. La afectación originada en la retina se caracteriza por la degeneración de las células ganglionares y la pérdida de axones. La presión intraocular es un factor de riesgo importante en el glaucoma, entre otros factores, implicando mecanismos bioquímicos que desencadenan la muerte de las células ganglionares. El ratón DBA/2J es un modelo de hipertensión ocular y de degeneración de las células ganglionares de la retina (CGR). Las características principales de éste son la dispersión del pigmento del iris (IPD) y la atrofia del estroma del iris (ISA) que conducen a la patogénesis del glaucoma. Los mecanismos bioquímicos que comprometen al sistema purinérgico en procesos patológicos como la degeneración glaucomatosa han sido estudiados en los últimos años, siendo de gran relevancia como posibles dianas farmacológicas para el tratamiento de diferentes neuropatías. Los receptores P2X comprenden una familia de siete canales iónicos de membrana activados por ligando (P2X1-7) que se activan por el ATP extracelular (ATPe). En particular, los receptores P2X7 podrían estar involucrados en la regulación de la transmisión sináptica y la muerte neuronal en la retina. Además, la excitotoxicidad mediada por ATP a través de la activación del receptor P2X7 sugiere su posible implicación en la degeneración neuronal y la pérdida de la función visual en las retinas glaucomatosas. Tan importante como la presencia de este receptor purinérgico es estudiar los niveles de ATP extracelular de la retina, así como evaluar los cambios en la expresión del transportador de nucleótidos vesicular (VNUT) y los niveles de ecto-nucleotidasa (E-NPP1) en este modelo murino de glaucoma durante el desarrollo de la enfermedad...

Estudio a corto y largo plazo de la melatonina y el 5-MCA-NAT como tratamiento en la hipertensión ocular y el glaucoma

El glaucoma engloba una serie de enfermedades que se caracterizan por la pérdida progresiva de las células ganglionares de la retina y la neuropatía del nervio óptico, que desencadenan finalmente una ceguera irreversible. La elevación de la presión intraocular (PIO) aparece como el principal desencadenante de esta patología en la mayoría de los casos, ya que produce una disminución del flujo sanguíneo hacia la retina y un aumento del estrés oxidativo. La estrategia terapéutica más común implica el uso de fármacos hipotensores, a menudo combinados, asociados a efectos no deseados. En este marco, la melatonina y sus análogos, como el 5-MCA-NAT, surgen como alternativas a los fármacos ya existentes, por sus propiedades hipotensoras y antioxidantes y, en el caso del 5-MCA-NAT, por su posible acción a largo plazo. El objetivo de esta tesis es elucidar los mecanismos de la acción hipotensora aguda ya descrita para estos compuestos, determinando además el receptor y las vías de señalización implicadas en esta respuesta a corto plazo. En este mismo sentido nos proponemos confirmar la existencia de efectos hipotensores a largo plazo, analizando esta respuesta a diferentes fármacos y esclareciendo si ésta se debe a la capacidad de estos compuestos como modificadores de la expresión génica de enzimas o receptores implicados en la regulación de la PIO...

Visual Discrimination Increase by Yellow Filters in Retinitis Pigmentosa

PURPOSE: The objective of this study was to evaluate, by halometry and under low illumination conditions, the effects of short-wavelength light absorbance filters on visual discrimination capacity in retinitis pigmentosa patients. METHODS: This was an observational, prospective, analytic, and transversal study on 109 eyes of 57 retinitis pigmentosa patients with visual acuity better than 1.25 logMAR. Visual disturbance index (VDI) was determined using the software Halo 1.0, with and without the interposition of filters which absorb (totally or partially) short-wavelength light between 380 and 500 nm. RESULTS: A statistically significant reduction in the VDI values determined using filters which absorb short-wavelength light was observed (p < 0.0001). The established VDIs in patients with VA logMAR <0.4 were 0.30 ± 0.05 (95% CI, 0.26–0.36) for the lens alone, 0.20 ± 0.04 (95% CI, 0.16–0.24) with the filter that completely absorbs wavelengths shorter than 450 nm, and 0.24 ± 0.04 (95% CI, 0.20–0.28) with the filter that partially absorbs wavelengths shorter than 450 nm, which implies a 20 to 33% visual discrimination capacity increase. In addition, a decrease of VDI in at least one eye was observed in more than 90% of patients when using a filter. CONCLUSIONS: Short-wavelength light absorbance filters increase visual discrimination capacity under low illumination conditions in retinitis pigmentosa patients. Use of such filters constitutes a suitable method to improve visual quality related to intraocular light visual disturbances under low illumination conditions in this group of patients. © 2016 American Academy of Optometry

Les mécanismes sous-jacents aux effets pathologiques cardiaques de l’angiotensine II dans le remodelage électrique et contractile entre les sexes

L’insuffisance cardiaque (IC) est associée à un taux de mortalité et d’hospitalisations élevé causant un fardeau économique important. Les deux causes majeures de décès de l’IC sont les arythmies ventriculaires létales et les sidérations myocardiques. Il est maintenant reconnu que l’angiotensine II (ANGII) est l'un des principaux médiateurs de l’IC. Ses effets délétères découlent de l’activation du récepteur de type 1 de l’ANGII (AT1) et entraînent le développement d’hypertrophie. Toutefois, son rôle dans la genèse d’arythmies demeure incompris. De ce fait, l'étude des mécanismes électriques et contractiles sous-jacents aux effets pathologiques de l’ANGII s’avère essentielle afin de mieux comprendre et soigner cette pathologie. Il est souvent perçu que les femmes sont protégées envers les maladies cardiovasculaires. Cependant, le nombre total de femmes décédant d’IC est plus grand que le nombre d’hommes. Également, l’impact des facteurs de risque diffère entre chaque sexe. Ces différences existent, mais les mécanismes sous-jacents sont encore peu connus. De plus, les femmes reçoivent fréquemment un diagnostic ou un traitement inapproprié en raison d’un manque d’information sur les différences entre les sexes dans la manifestation d’une pathologie. Ce manque de données peut découler du fait que les sujets de sexe féminin sont souvent sous-représentés dans les essais cliniques ou la recherche fondamentale ce qui a grandement limité l’avancement de nos connaissances sur ~50 % de la population. Ainsi, il semble plus que nécessaire d’approfondir notre compréhension des différences entre les sexes, notamment dans la progression de l’IC. L’utilisation d’un modèle de souris transgénique surexprimant le récepteur AT1 (souris AT1R) a permis d’étudier les changements électriques, structurels et contractiles avant et après le développement d’hypertrophie. Premièrement, chez les souris AT1R mâles, un ralentissement de la conduction ventriculaire a été observé indépendamment de l’hypertrophie. Ce résultat était expliqué par une réduction de la densité du courant Na+, mais pas de l’expression du canal. Ensuite, le rôle des protéines kinases C (PKC) dans la régulation du canal Na+ par l’ANGII a été exploré. Les évidences ont suggéré que la PKCα était responsable de la modulation de la diminution du courant Na+ chez les souris AT1R mâles et dans les cardiomyocytes humains dérivés de cellules souches induites pluripotentes (hiPSC-CM) en réponse à un traitement chronique à l’ANGII. Ensuite, les différences entre les sexes ont été comparées chez la souris AT1R. Une plus grande mortalité a été constatée chez les femelles AT1R suggérant qu’elles sont plus sensibles à la surexpression de AT1R. Le remodelage électrique ventriculaire a donc été comparé entre les souris AT1R des deux sexes. Les courants ioniques étaient altérés de façon similaire entre les sexes excluant ainsi leur implication dans la mortalité plus élevée chez les femelles. Ensuite, l’homéostasie calcique et la fonction cardiaque ont été étudiées. Il a été démontré que les femelles développaient une hypertrophie et une dilatation ventriculaire plus sévère que les mâles. De plus, les femelles AT1R avaient de petits transitoires calciques, une extrusion du Ca2+ plus lente ainsi qu’une augmentation de la fréquence des étincelles Ca2+ pouvant participer à des troubles contractiles et à la venue de post-dépolarisations précoces. En conclusion, l’ANGII est impliquée dans le remodelage électrique, structurel et calcique associé à l'émergence de l’IC. De surcroît, ces altérations affectent plus sévèrement les femelles soulignant la présence de différences entre les sexes dans le développement de l’IC.

Comparaison entre la dérive de VO₂ et de FC chez des sujets de deux niveaux d'endurance

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.

Effects of concealed conduction on AV nodal function

Mémoire numérisé par la Direction des bibliothèques de l'Université de Montréal.