Browsing by Issue Date, starting with "2024-12-11"
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- Physiological response of Palaemon elegans (Rathke, 1836) to anthropogenic stressors: synergistic impacts of heatwaves and UV filters from sunscreensPublication . Autiero, Alexandro; Herrera Ulibarri, Alicia; Vinagre, CatarinaHeat waves are prolonged periods of unusually high temperatures representing a threat to marine organisms. Their intensification raised concerns about the impacts on aquatic organisms and ecosystem dynamics. On the other hand, the rapid escalation of tourism particularly in tropical and subtropical regions and the greater awareness of photodamage caused by solar UV radiation increased the use of sunscreens. Indeed, UV filters found in sunscreen have recently been identified as emerging pollutants in coastal waters due to their stability in the environment and the potential to accumulate in marine organisms. Exposure to these components has been proven toxic to many aquatic species. UV filters cause substantial levels of reactive oxygen species (ROS). This study analyses the effects of extreme weather temperatures with two different sunscreens on Palaemon elegans (Rathke, 1836). Two temperatures (20°C, and 32°C) and two different sunscreens (one labelled as eco-friendly and the other not) were tested in a full factorial experiment for 12 hours. Shrimps had three sampling times: 1, 6 and 12 hours of exposure. At each of sampling time, the combined effect of temperatures and sunscreens was analysed in hepatopancreas and muscle. Cellular biomarkers associated with oxidative stress such as GST – Glutathione-S-Transferase, SOD – Superoxide Dismutase, with oxidative damage, LPO – Lipid peroxidation, and metabolic biomarkers such as COX – Cytochrome c oxidase, ETS – Electron transport system, were used as indicators of the shrimp’s physiological response. Analysis of metabolic biomarkers in the muscle showed that while ETS exhibited a higher metabolic demand at elevated temperatures, decreased levels of COX indicated mitochondrial dysfunction caused by oxidative stress at high temperatures, further enhanced by exposure to non-ecofriendly sunscreen. These effects were increased in the non-eco-friendly sunscreen. LPO activity showed oxidative stress in organisms exposed to elevated temperatures and treatments with non-ecofriendly sunscreen. Whereas oxidative stress biomarkers such as GST and SOD showed that these antioxidant defences were saturated due to ROS accumulation related to high temperature and chemical pollutants.
- Analysis of sediment transport in coastal areas within the AX-COAST ProjectPublication . Husemann, Paul Lasse; Costas, Susana; Lima, Márcia; Coelho, CarlosThis report documents my six-month internship at the University of Aveiro, where I contributed to the AX-COAST: Cross-shore features and internationalization of the COAST tool project, an initiative aimed at improving coastal management strategies by enhancing the COAST tool for modelling shoreline evolution in different scenarios of sediment transport conditions and coastal defence interventions. (...)
- A abordagem terapêutica na Perturbação do Espetro do AutismoPublication . Carvoeiras, Inês Martins; Serralheiro, Ana Isabel AzevedoA Perturbação do Espetro do Autismo (PEA) é uma perturbação complexa do neurodesenvolvimento, que se caracteriza por défices na comunicação e na interação social e por comportamentos restritivos e repetitivos, que afetam de forma significativa a qualidade de vida dos indivíduos. De igual modo, é comum a presença de comorbilidades, sendo as mais frequentes, a Perturbação de Hiperatividade e Défice de Atenção, Ansiedade, Perturbação Obsessiva-compulsiva, Depressão, Alterações Comportamentais, Labilidade Emocional e Alterações do Sono. Até à data, a sua etiologia exata permanece desconhecida, sendo, no entanto, sugerido que esta perturbação seja resultado de uma interação complexa entre diversos fatores, principalmente, fatores genéticos e ambientais. Durante as últimas décadas, a literatura tem vindo a apontar para uma mudança alarmante no padrão epidemiológico da PEA, sendo observado globalmente um aumento da sua prevalência desde o século XXI. Posto isto, e dado que atualmente não existe cura para a PEA, o tratamento centra-se no controlo das manifestações clínicas, através de terapia que envolvam componentes terapêuticas e educativas, que assentem no treino de autonomia e de socialização, e no tratamento das comorbilidades mediante o uso de estimulantes do sistema nervoso central, antipsicóticos atípicos, antiepiléticos, antidepressivos e agonistas do recetor da melatonina.