Browsing by Author "Carvalho, Sara"
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- Characterization of 2-year progression of different phenotypes of nonproliferative diabetic retinopathyPublication . Ribeiro, Luísa; Marques, Inês P.; Santos, Torcato; Carvalho, Sara; Santos, Ana Rita; Mendes, Luís; Lobo, Conceição; Cunha-Vaz, JoséThe aim of the study was to characterize the 2-year progression of risk phenotypes of nonproliferative diabetic retinopathy (NPDR) in type 2 diabetes (T2D) phenotype C, or ischemic phenotype, identified by decreased skeletonized retinal vessel density (VD), ≥2 SD over normal values, and phenotype B, or edema phenotype, identified by increased retinal thickness, i.e., subclinical macular edema, and no significant decrease in VD. A prospective longitudinal cohort study (CORDIS, NCT03696810) was conducted with 4 visits (baseline, 6 months, 1 year, and 2 years). Ophthalmological examinations included best-corrected visual acuity, color fundus photography (CFP), and optical coherence tomography (OCT) and OCT angiography. Early Treatment Diabetic Retinopathy Study grading was performed at the baseline and last visits based on 7-field CFP. Results: One hundred and twenty-two eyes from T2D individuals with NPDR fitted in the categories of phenotypes B and C and completed the 2-year follow-up. Sixty-five (53%) of the eyes were classified as phenotype B and 57 (47%) eyes as phenotype C. Neurodegeneration represented by thinning of the ganglion cell layer and inner plexiform layer was present in both phenotypes and showed significant progression over the 2-year period (p < 0.001). In phenotype C, significant progression in the 2-year period was identified in decreased skeletonized VD (p = 0.01), whereas in phenotype B microvascular changes involved preferentially decrease in perfusion density (PD, p = 0.012). Phenotype B with changes in VD and PD (flow) and preferential involvement of the deep capillary plexus (p < 0.001) is associated with development of center-involved macular edema. In the 2-year period of follow-up, both phenotypes B and C showed progression in retinal neurodegeneration, with changes at the microvascular level characterized by decreases in PD in phenotype B and decreases in VD in phenotype C.
- Composing a sound installation to a specific outdoor place employing soundwalking as a methodologyPublication . Oliveira, Elder; Lopes, Filipe; Carvalho, SaraThis paper presents the methodology employed to create the sound installation Saving Shapes (2016-2018). Based on that, we will present some remarks about composing music for sound installations at outdoor places on exhibition for prolonged periods of time, particularly strategies to avoid audio loops. Our approach is based on three phases: (1) gather a wide range of phenomenological “information” from the place, mostly by performing soundwalks, taking notes and doing sound recordings (2) analyzing that “information” and composing music to be performed and installed at that specific place (3) periodically recreate the composition/installation using new “information” retrieved by repeating step number 1. Our research is mostly based and inspired on ideas from soundscape studies and artistic practices of well-known authors such as Murray Schafer (1977), Hildegard Westerkamp (1974), Barry Truax (2001), David Abram (1996) and Bernie Krause (2013). For our specific work and research, Westerkamp and Krause are two key figures. On the one hand, Westerkamp (1974) addresses the surrounding environment as a performing place to be experienced while one performs a soundwalk. She believes that such a “performance” (i.e. soundwalking) within complex soundscapes (e.g. outdoor locations) is a rich sonic experience, thus, we believe, interesting to create (and recreate) music compositions. Soundwalking became the central aspect of our creative and analytical methodology, understood here as a multifaceted activity to listen, record and devise music compositions; on the other hand, Krause defined biophony, geophony and antrophony as complementary spheres of the soundscape, thus, defining a clear theoretical and practical reference about the acoustic elements of a given place. Krause’s spheres of the soundscape, together with Westerkamp’s soundwalk, are essential to our methodology and they form the theoretical and practical basis of our proposed creative process. Saving Shapes (2016-2018) was composed for an outdoor space. We believe that outdoor spaces, as opposed to indoor spaces, are best suited for our proposed creative methodology. Outdoor spaces offer an infinitude of complexities that (might) transform and dialog with instrumental and electroacoustic sounds. Lastly, we will discuss the benefits of revisiting the same place to experience its particularities and meanings as a methodology, as opposed to using a computer to retrieve data in real time during the period of the installation. A lot of objects and narratives were constantly explored during a long period of time to instigate new (or old) connections between environmental sounds and the creative process. It materializes the multiple roles of soundwalking and the idiosyncrasy of the “human factor” to rebuild perspectives and transforming pre-existing compositions for a specific place.
- Identificação de compostos que modulam a patogénese da doença de Machado-Joseph em C.elegans: autofagia como alvo terapêutico: identification of small compounds that modulate pathogenesis of Machado-Joseph disease in a C.elegans model: targeting autophagyPublication . Carvalho, Sara; Prudêncio, Cristina; Castro, Andreia; Maciel, PatríciaA doença de Machado-Joseph (DMJ) ou ataxia espinocerebelosa do tipo 3 (SCA3), conhecida por ser a mais comum das ataxias hereditárias dominantes em todo o mundo, é uma doença neurodegenerativa autossómica dominante que leva a uma grande incapacidade motora, embora sem alterar o intelecto, culminando com a morte do doente. Atualmente não existe nenhum tratamento eficaz para esta doença. A DMJ é resultado de uma alteração genética causada pela expansão de uma sequência poliglutamínica (poliQ), na região C-terminal do gene que codifica a proteína ataxina-3 (ATXN3). Os mecanismos celulares das doenças de poliglutaminas que provocam toxicidade, bem como a função da ATXN3, não são ainda totalmente conhecidos. Neste trabalho, usamos, pela sua simplicidade e potencial genético, um pequeno animal invertebrado, o nemátode C. elegans, com o objetivo de identificar fármacos eficazes para o combate contra a patogénese da DMJ, analisando simultaneamente o seu efeito na agregação da ATXN3 mutante nas células neuronais in vivo e o seu impacto no comportamento motor dos animais. Este pequeno invertebrado proporciona grandes vantagens no estudo dos efeitos tóxicos de proteínas poliQ nos neurónios, uma vez que a transparência das suas 959 células (das quais 302 são neurónios) facilita a deteção de proteínas fluorescentes in vivo. Para além disso, esta espécie tem um ciclo de vida curto, é económica e de fácil manutenção. Neste trabalho testámos no nosso modelo transgénico da DMJ com 130Qs em C.elegans dois compostos potencialmente moduladores da agregação da ATXN3 mutante e da resultante disfunção neurológica, atuando pela via da autofagia. De modo a validar a possível importância terapêutica da ativação da autofagia os compostos candidatos escolhidos foram o Litío e o análogo da Rapamicina CCI-779, testados independentemente e em combinação. A neuroproteção conferida pelo Litío e pelo CCI-779 independentemente sugere que o uso destes fármacos possa ser considerado uma boa estratégia como terapia para a DMJ, a testar em organismos evolutivamente mais próximos do humano. A manipulação da autofagia, segundo vários autores, parece ser benéfica e pode ser a chave para o desenvolvimento de novos tratamentos para várias doenças relacionadas com a agregação proteica e o envelhecimento.
- Music composition as a way of learning: emotions and the situated selfPublication . Veloso, Ana Luísa; Carvalho, Sara