Percorrer por data de Publicação, começado por "2026-02-17"
A mostrar 1 - 3 de 3
Resultados por página
Opções de ordenação
- Using reflectance to measure chlorophyll a in corals: calibration and implications of skeletal optical propertiesPublication . Watty, Kay; Schoepf, Verena; Johnson, Kelly W.; Littke, Sophie; Zande, Rene M. van derClimate change-driven coral bleaching and associated chlorophyll (Chl) loss increasingly threaten coral reefs, highlighting the need for non-invasive, cost-effective tools to assess corals’ physiological condition. Researchers have explored the reflectance-based Normalized Difference Vegetation Index (NDVI) as a proxy for Chl a. However, almost no calibration curves exist to date; thus it remains unknown if the relationship between Chl a and NDVI differs among coral species, and whether it is influenced by skeletal optical properties. Here, we correlated Chl a content to NDVI in three coral species with different skeletal morphologies and reflectance modes across a range of health states (i.e., bleaching states). We found a strong positive relationship between Chl a and NDVI in all species, validating NDVI as a proxy for Chl a in corals. However, this relationship is non-linear, showing deviations at the highest and lowest ends of the pigmentation spectrum. We propose that in healthy states, this non-linearity is due to pigment self-shading, whereas in bleaching states, it is caused by backscattering of light by the increasingly exposed coral skeleton, because pigment loss enhances absorption by the remaining Chl a pigments and lowers, rather than increases, reflectance. To avoid Chl a under- or overestimation, we recommend to log-transform Chl a and create species-specific calibration curves. Overall, the non-invasive, repeatable, and scalable nature of reflectance measurements and NDVI make them valuable tools for assessing coral health both ex- and in situ. They provide a comprehensive view of the holobiont’s physiological condition and hold potential for broader applications in reef-scale monitoring, remote sensing, coral restoration, and conservation.
- Living with a Veteran with trauma: impact on family functioning using the genogram as a research toolPublication . Brites, Rute; Nunes, Odete; Hipólito, João; Brandão, Tânia; Correia, António; Nunes, CristinaIntroduction: Although the psychological impact of war on veterans, particularly the development of post-traumatic stress disorder (PTSD), has been well documented, the long-term effects on their families have been less widely studied. Research suggests that veterans’ trauma can disrupt relationships and contribute to secondary/intergenerational trauma within the family. Objective: This study uses genograms to explore how PTSD symptoms experienced by veterans have influenced family relationships over time, and to uncover patterns of intergenerational and systemic impact in families of Portuguese Overseas War veterans. Method: A qualitative approach involving semi-structured interviews with 32 families (each comprising a veteran, their spouse, and at least one adult child) was used (n =100). The data were synthesized into genograms to visually map family structure, relationship quality, and patterns of psychological distress. Cross-family analysis was then conducted to identify common relational themes. Results: Families were clustered into four main impact groups: maximum negative impact, limited negative impact, no impact, and protective impact. These classifications reflect variations in family functioning, mental health symptoms, and relational patterns. In some families, the veteran’s trauma appeared to affect multiple subsystems, while in others, spouses played a buffering/protective role. A fifth group was identified, with no consistent pattern. Conclusion: Findings emphasize the complexity and variability of trauma transmission within families, highlighting both vulnerability and resilience. Using genograms proved effective in capturing systemic dynamics. These results emphasize the importance of adopting a family-systems approach in the clinical treatment of veterans affected by PTSD and suggest avenues for future research.
- Application of solar HVAC system in residential buildings for winter conditions in mediterranean climatePublication . Conceição, Eusébio; Gomes, João; Conceição, Margarida; Conceição, Maria Inês; Lúcio, Maria Manuela Jacinto do Rosário; Awbi, HazimThe design of thermal strategies applied in buildings based on the use of renewable energies can play an important role in the development of a built environment that is better adapted to the climate. This paper is focused on the application of a renewable solar energy system coupled with a Heating, Ventilation and Air-Conditioned (HVAC) system to promote occupants’ thermal comfort (TC) and indoor air quality (IAQ) in buildings during heating season. In the building thermal design, a building thermal dynamic model is used to calculate the temperatures of the opaque and transparent building surfaces, the temperature of the water supply ducts, the TC level and the IAQ level, among other variables. The TC conditions of the occupants were evaluated using the Predicted Mean Vote index, commonly used in the literature in similar studies. IAQ was assessed by the usual carbon dioxide concentration in environments where most of the pollution is of human origin. The numerical study was carried out in a virtual residential building consisting of two floors and seven compartments. The building is occupied at night and at midday. Two cases were studied, considering, respectively, the non-use and use of the solar HVAC system. The solar HVAC system consists of solar water collectors, installed above the roof area, and thermo-convector heat exchangers, installed inside each occupied space. The results show that the application of this solar HVAC system in a Mediterranean-type climate is able to guarantee, during occupancy, acceptable TC levels in three compartments and near acceptable TC levels in one compartment. Regarding IAQ, acceptable level can be achieved throughout the day.