Browsing by Author "Cardoso, Helena"
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- Benchmarking computer-vision-based facial emotion classification algorithms while wearing surgical masksPublication . Coelho, Luis; Reis, Sara; Moreira, Cristina; Cardoso, Helena; Sequeira, Miguela; Coelho, RaquelEffective human communication relies heavily on emotions, making them a crucial aspect of interaction. As technology progresses, the desire for machines to exhibit more human-like characteristics, including emotion recognition, grows. DeepFace has emerged as a widely adopted library for facial emotion recognition. However, the widespread use of surgical masks after the COVID-19 pandemic presents a considerable obstacle to its performance. To assess this issue, we conducted a benchmark using the FER2013 dataset. The results revealed a substantial performance decline when individuals wore surgical masks. “Disgust” suffers a 22.6% F1-score reduction, while “Surprise” is least affected with a 48.7% reduction. Addressing these issues improves human–machine interfaces and paves the way for more natural machine communication.
- Nonthermal high-pressure microalgae extracts: A new source of natural ingredients for cosmeticsPublication . Garcia, Mónica P.; Regueiras, Ana; Lopes, Graciliana; Matos, Gabriela; Silva, Lucília P. da; Cerqueira, Mariana T.; Cardoso, Helena; Correia, Nádia; Saraiva, Jorge A.; Silva, Joana L.; Martins, Rosário; Marques, Alexandra P.Microalgae are one of the most prominent sources of ingredients for the cosmetic industry not only due to their diversity but, importantly, due to the low environmental impact in production and extraction. A sustainable extraction process requires the use of effective and environmentally friendly solvents that guarantee an extract with a relevant content and in high yields. In this work, Chlorella vulgaris, Nannochloropsis oceanica, Tetraselmis chui, Chlorococcum amblystomatis and Phaeodactylum tricornutum microalgae species grown in tubular photobioreactors were used to validate a high-pressure extraction (HPE) method. Extraction yields up to 57 % were obtained depending on the used solvent (water, ethanol, or acetone). The extracts were then characterized regarding their phytochemical composition (total phenolic, protein, chlorophylls content, and chlorophyll a). Aqueous extracts showed high protein content (6–51 μg/mg biomass), while ethanolic and acetone extracts showed high amounts of phenolic compounds (0.0007–0.03 μg/mg biomass). The levels of photosynthetic pigments (0.1–11 μg/mg biomass) associated with antioxidant and anti-inflammatory properties were higher when extracted using ethanol and high-pressures. Chlorella vulgaris aqueous extracts presented higher protein content while Nannochloropsis oceanica and Tetraselmis chui ethanolic extracts presented higher amounts of photosynthetic pigments. The effect of the extracts over the metabolic activity of primary human dermal fibroblasts, keratinocytes, melanocytes, and adipocytes was dependent on both microalgae species and cell type. In adipocytes and fibroblasts, extracts presented an IC50 > 500 μg/mL, except for the one of Phaeodactylum tricornutum in fibroblasts (IC50 < 150 μg/mL). In contrast, the IC50 was below 500 μg/mL for most of the extracts in keratinocytes and melanocytes. Overall, extracts of sustainably-grown microalgae obtained by a high-pressure method are a promising source of natural ingredients for cosmeceutical applications.