Retinal biomarkers of Alzheimer’s disease: insights from transgenic mouse models

In this paper, we use the retina as a window into the central nervous system and in particular to assess changes in the retinal tissue associated with the Alzheimer’s disease. We imaged the retina of wild-type (WT) and transgenic mouse model (TMM) of Alzheimer’s disease with optical coherence tomography and classify retinas into the WT and TMM groups using support vector machines with the radial basis function kernel. Predictions reached an accuracy over 80% at the age of 4 months and over 90% at the age of 8 months. Texture analysis of computed fundus reference images suggests a more heterogeneous organization of the retina in transgenic mice at the age of 8 months in comparison to controls.This study was supported by the Neuroscience Mantero Belard Prize 2015 (Santa Casa da Misericórdia)(MB-1049-2015), by The Portuguese Foundation for Science and Technology (PEst-UID/NEU/04539/2013), by FEDER-COMPETE (POCI-01-0145-FEDER-007440) and Centro 2020 Regional Operational Programme (CENTRO-01-0145-FEDER-000008: BrainHealth 2020).info:eu-repo/semantics/publishedVersio

Beatings: A Web Application to Foster the Renaissance of the Art of Musical Temperaments

(Abstract to follow

Digital ocular fundus imaging: a review

Ocular fundus imaging plays a key role in monitoring the health status of the human eye. Currently, a large number of imaging modalities allow the assessment and/or quantification of ocular changes from a healthy status. This review focuses on the main digital fundus imaging modality, color fundus photography, with a brief overview of complementary techniques, such as fluorescein angiography. While focusing on two-dimensional color fundus photography, the authors address the evolution from nondigital to digital imaging and its impact on diagnosis. They also compare several studies performed along the transitional path of this technology. Retinal image processing and analysis, automated disease detection and identification of the stage of diabetic retinopathy (DR) are addressed as well. The authors emphasize the problems of image segmentation, focusing on the major landmark structures of the ocular fundus: the vascular network, optic disk and the fovea. Several proposed approaches for the automatic detection of signs of disease onset and progression, such as microaneurysms, are surveyed. A thorough comparison is conducted among different studies with regard to the number of eyes/subjects, imaging modality, fundus camera used, field of view and image resolution to identify the large variation in characteristics from one study to another. Similarly, the main features of the proposed classifications and algorithms for the automatic detection of DR are compared, thereby addressing computer-aided diagnosis and computer-aided detection for use in screening programs.Fundação para a Ciência e TecnologiaFEDErPrograma COMPET

Never the less: a performance on networked art

Never The Less is a live audio-visual (A/V) networked performance, where participants are able to interact remotely and collaboratively. It adopts the newly-proposed web-based A/V Akson system, designed for an internet infrastructure, which allows both musical and visual content generation and interaction across multiple devices in remote locations. The system was built with great emphasis on live-performance and human collaboration, where experts and non-experts (i.e., artists and public) exist at the same level.info:eu-repo/semantics/publishedVersio

O puzzle do prémio de risco do mercado acionista : uma revisão da literatura com uma aplicação a Portugal

Mestrado em Economia Monetária e FinanceiraEsta dissertação debruça-se sobre o prémio de risco do mercado accionista (Equity Premium Puzzle — EPP): a rendibilidade em excesso das acções face aos activos sem risco é demasiado elevada para os níveis de aversão ao risco e de volatilidade do consumo considerados normais, numa economia sem fricções e com mercados completos. Desde que a temática foi iniciada por Mehra e Prescott [ 1985], diversas soluções foram apontadas, quer com mercados perfeitos e agentes optimizadores, quer com mercados imperfeitos, quer com agentes não inteiramente racionais. De modo a averiguar se o EPP é um fenómeno exclusivo das economias mais avançadas, com mercados de capitais desenvolvidos, testamos para Portugal, se no período 1977-2001 se verificou este puzzle. Os resultados confirmam a existência do puzzle, ainda que o rácio de Sharpe seja baixo.This dissertation analyses the Equity Premium Puzzle — EPP. The puzzle exists because the excess of stock returns over the risk-free rate is larger than can be explained by standard models of rational asset prices in a frictionless economy with complete markets. Since Mehra and Prescott [ 1985] influential study, many authors have attempted to solve this puzzle following different strategies: in a perfect market environment, with imperfect markets and with a behavioral finance framework. I investigate the existence of thispuzzle for Portugal in the period 1977-2001. I find that there is a puzzle even with a low Sharpe ratio.info:eu-repo/semantics/publishedVersio

Synthtic OCT Data for image processing performance testing

The use of synthetic images is needed for testing the performance of image processing methods in order to establish a ground truth to test performance metrics. However, these synthetic images do not represent real applications. The aim of this paper is to build a mathematical model to obtain a synthetic noise-free image mimicking a real Optical Coherence Tomography (OCT) B-scan or volume from the human retina, in order to establish a ground truth for filtering performance metrics in this context. Moreover we also suggest a method to add speckle noise to this image based on the speckle noise of the given OCT volume. In this way we establish a replicable method to obtain a ground truth for image processing performance metrics that actually mimics a real case.FCTFEDERProgram COMPET

Optical coherence tomography: automatic retina classification through support vector machines

Optical coherence tomography (OCT) is becoming one of the most important imaging modalities in ophthalmology due to its non-invasiveness and by allowing the visualisation the human retina structure in detail. It was recently proposed that OCT data embeds functional information from the human retina. Specifically, it was proposed that blood–retinal barrier status information is present within OCT data from the human retina. Besides this ability, the authors present data supporting the idea of having the OCT data encoding the ageing of the retina in addition to the disease (diabetes) condition from the healthy status. The methodology followed makes use of a supervised classification procedure, the support vector machine (SVM) classifier – based solely on the statistics of the distribution of OCT data from the human retina (i.e. OCT data between the inner limiting membrane and the retinal pigment epithelium). Results achieved suggest that information on both the healthy status of the blood–retinal barrier and on the ageing process co-exist encoded within the optical properties of the human retina

Texture analysis and Its applications in biomedical imaging: a survey

Texture analysis describes a variety of image analysis techniques that quantify the variation in intensity and pattern. This paper provides an overview of several texture analysis approaches addressing the rationale supporting them, their advantages, drawbacks, and applications. This survey’s emphasis is in collecting and categorising over five decades of active research on texture analysis.Brief descriptions of different approaches are presented along with application examples. From a broad range of texture analysis applications, this survey’s final focus is on biomedical image analysis. An up-to-date list of biological tissues and organs in which disorders produce texture changes that may be used to spot disease onset and progression is provided. Finally, the role of texture analysis methods as biomarkers of disease is summarised.Manuscript received February 3, 2021; revised June 23, 2021; accepted September 21, 2021. Date of publication September 27, 2021; date of current version January 24, 2022. This work was supported in part by the Portuguese Foundation for Science and Technology (FCT) under Grants PTDC/EMD-EMD/28039/2017, UIDB/04950/2020, PestUID/NEU/04539/2019, and CENTRO-01-0145-FEDER-000016 and by FEDER-COMPETE under Grant POCI-01-0145-FEDER-028039. (Corresponding author: Rui Bernardes.)info:eu-repo/semantics/publishedVersio

Projeto pedagógico para o curso de graduação em Administração: uma proposta metodológica

Tese (doutorado) - Universidade Federal de Santa Catarina, Centro Tecnológico. Programa de Pós-Graduação em Engenharia de ProduçãoO presente estudo tem por objetivo geral apresentar as fases/etapas que devem ser levadas em conta na revisão, análise e implementação de Projeto Pedagógico para o curso de graduação estar em constante interação com o processo de transformação porque passam as organizações e a sociedade. A pesquisa é do tipo exploratória, descritiva e avaliativa. As técnicas de coleta de dados utilizadas foram a observação, a análise documental e a pesquisa bibliográfica. Os dados e informações coletados são tratados de modo qualitativo. Assuntos como ambiente externo (direto e indireto) das organizações, metodologias de planejamento estratégico, currículo e teoria curricular e a evolução do ensino de ensino de administração no Brasil são discutidos, visando à formulação da proposta metodológica de revisão, análise e implementação de Projeto Pedagógico para o curso de graduação em administração. A proposta metodológica apresenta sete fases, ou seja: Fase 1: sensibilização e pressupostos: a necessidade da mudança; Fase 2: objetivos do projeto pedagógico; Fase 3: resgate histórico do curso e do mercado; Fase 4: realidade atual do curso e de mercado - diagnóstico estratégico; Fase 5: a busca da identidade própria - a questão do currículo; Fase 6: checagem do currículo proposto em relação a realidade interna e externa e Fase 7: implantação e monitoração. Para cada uma das fases apresentadas são formulados questionamentos a partir dos fundamentos discutidos em cada uma delas. De posse destes questionamentos como por meio dos fundamentos que caracterizam as fases levadas em conta, os gestores dos cursos de graduação em administração terão condições de verificarem como que se encontra o curso, visando ao estabelecimento e à implementação de projeto pedagógico para alinhar as atividades realizadas tanto do ambiente interno quanto do externo ao curso. Ressalta-se, a importância da utilização da abordagem qualitativa, pelo fato de a mesma possibilitar a construção e a reconstrução do projeto de modo contínuo. Também, a negociação, a flexibilidade e a construção coletiva devem ser respeitadas para atender as particularidades de cada curso como da região. Os atores sociais devem ser envolvidos em todas as fases A proposta em pauta serve apenas como referencial e não como um produto acabado para ser aplicado a quaisquer cursos de graduação