18 documents found, page 1 of 2
SIGAA: signaling automated analysis: a new tool for Ca2+ signaling quantificati...
Lopes, Rafael Faria; Gonçalves-Ribeiro, Joana; Sebastião, Ana M.; Meneses, Carlos; Vaz, Sandra H.Astrocytes are non-neural cells, restricted to the brain and spinal cord, whose functions and morphology depend on their location. Astrocyte–astrocyte and astrocyte–neuron interactions occur through cytoplasmic Ca2+ level changes that are assessed to determine cell function and response (i.e., drug testing). The evaluation of alterations in intracellular Ca2+ levels primarily relies on fluorescence imaging tech...
Voice spectrum energy band and tilt analysis for Bulbar ALS screening
Cordeiro, Hugo; Meneses, CarlosThis paper presents a comparison between the spectral analysis of the voices from patients diagnosed with bulbar amyotrophic lateral sclerosis (ALS) and healthy speakers. The main objective is to understand how this disease affects the voice and, consequently, the spectrum of the patients' voices. The spectrum is analysed in three energy bands, where energy peaks are estimated and the tilt between these bands i...
Deteção de ELA através de análise espectral: novo parâmetro e otimizações
Cordeiro, Hugo; Meneses, CarlosA análise da média e desvio padrão de parâmetros baseados no declive espectral dos sinais de fala demonstrou em trabalhos anteriores capacidade de discriminação entre oradores diagnosticados com Esclerose Lateral Amiotrófica (ELA) Bulbar e oradores saudáveis. Este trabalho continua a investigação do espectro do sinal de fala neste contexto e apresenta uma solução que funde os parâmetros apresentados anteriormen...
APC speech coding techniques applied to ECG signals
Meneses, Carlos; Lourenço, André; Martins, Guilherme; Silva, DanielThis paper describes an ECG signal coding with an adaptive predictive coding scheme using speech techniques like linear predictive coding and long-term prediction.
Caffeine has a dual influence on NMDA receptor-mediated glutamatergic transmiss...
Silva Martins, Robertta; D.M., Rombo; Ribeiro, Joana; Meneses, Carlos; Peralva Borges Martins, Vladimir Pedro; Ribeiro, Joaquim A.; Vaz, Sandra H.Caffeine, a stimulant largely consumed around the world, is a non-selective adenosine receptor antagonist, and therefore caffeine actions at synapses usually, but not always, mirror those of adenosine. Importantly, different adenosine receptors with opposing regulatory actions co-exist at synapses. Through both inhibitory and excitatory high-affinity receptors (A(1)R and A(2)R, respectively), adenosine affects ...
Adaptive predictive coding speech coding techniques applied to electrocardiogra...
Silva, Daniel; Martins, Guilherme; Lourenço, André; Meneses, CarlosThis paper describes a lossy ECG signal coder with an adaptive predictive coding scheme initially proposed for speech coders. The predictors include linear predictive coding that takes advantage of the correlation between consecutive samples and long-term predictor that takes advantage of the signal quasi-periodicity. The prediction residue, with less dynamic range and therefore able to be encoded with less bit...
Espectro de voz de pacientes diagnosticados com ELA bulbar: Análise do declive ...
Cordeiro, Hugo; Meneses, CarlosEste estudo apresenta uma comparação entre a análise espetral de vozes de pacientes diagnosticados com Esclerose Lateral Amiotrófica (ELA) bulbar e oradores saudáveis. O principal objetivo é entender de que modo esta doença afeta a voz e consequentemente o espectro das vozes dos pacientes. Os espectros são analisados em duas bandas de energia, onde são caracterizados picos de energia e consequentemente também o...
Caffeine has a dual influence on NMDA receptor–mediated glutamatergic transmiss...
Silva Martins, Robertta; Rombo, Diogo M.; Gonçalves-Ribeiro, Joana; Meneses, Carlos; Borges-Martins, Vladimir P. P.; Ribeiro, Joaquim A.; Vaz, Sandra H.Caffeine, a stimulant largely consumed around the world, is a non-selective adenosine receptor antagonist, and therefore caffeine actions at synapses usually, but not always, mirror those of adenosine. Importantly, different adenosine receptors with opposing regulatory actions co-exist at synapses. Through both inhibitory and excitatory high-affinity receptors (A1R and A2R, respectively), adenosine affects NMDA...
Parâmetros espectrais de vozes saudáveis e patológicas: Comparação de resultado...
Cordeiro, Hugo; Meneses, CarlosEste artigo apresenta um estudo comparativo entre três parâmetros espectrais na discriminação entre vozes saudáveis e patológicas. Os parâmetros avaliados envolvem a análise do primeiro pico espectral, uma medida da relação sinal-ruído e o declive entre duas bandas de baixa frequência do sinal de fala. O declive entre as bandas de baixa frequência é proposto como otimização do primeiro pico espectral, de modo a...
Spectral features of healthy and pathological voices: results comparison betwee...
Cordeiro, Hugo; Meneses, CarlosThis paper presents a comparative study between three spectral parameters in the discrimination between healthy and pathological voices. The evaluated parameters involve the analysis of the first spectral peak, the Relative Power of the Periodic Component, which corresponds to a measure of the signal-to-noise ratio and the Low Band Spectral Tilt. The Low Band Spectral Tilt is proposed as optimization of the fir...