Sapientia
Repositório Científico da UAlg
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Physiological impact of air quality in urban gulls and its implications for their use as pollution sentinels in coastal cities
Publication . Oliveira, Catarina Fernandes de; Vinagre, Catarina; Navarro, Joan
Urban air pollutants pose significant threats to both wildlife and humans due to their persistence and potential for bioaccumulation. Sentinel species such as the yellow-legged gull (Larus michahellis) are valuable to assess environmental contamination. Due to their stationary nesting behaviour and continuous exposure to local air conditions, gull chicks are particularly valuable as early warning sentinels for urban air quality. In this study, we assessed the impact of airborne pollutants (PM2.5, PM10 and NO2) on detoxification and oxidative stress biomarkers in 56 yellow-legged gull chicks in the overpopulated city of Barcelona, Spain. We analysed five biomarkers – cholinesterases (AChE, BChE), carboxylesterases (pNPA-CE, pNPB-CE), and glutathione S-transferase (GST) - in relation to the cumulative PM2.5, PM10, and NO2 levels during the entire life of each gull chick. After accounting for individual variation in size, developmental stage, and trophic ecology (via stable isotope analysis), we found significant associations between air pollution and enzyme activity. Specifically, BChE and pNPB-CE activities were positively associated with PM10 levels, while GST activity showed a positive correlation with NO2 concentrations and a negative one with chick body weight. Our findings suggest that incorporating enzymatic biomarkers such as BChE, CE, and GST into physiological biomonitoring programs offers a practical and sensitive approach for evaluating the impact of urban air pollution, supporting integrated environmental and public health efforts within the One Health framework.
Cloning and preliminary functional analysis of zebrafish BiP, an ATPase-Dependent endoplasmic reticulum chaperone
Publication . Gonzalez, Alejandra Febus; Melo, Eduardo José Xavier Rodrigues de Pinho e
The endoplasmic reticulum chaperone BiP (Binding immunoglobulin Protein) plays a fundamental role in protein homeostasis, mediated by its ATPase activity. To investigate the evolutionary conservation and functionality of BiP in vertebrates, we cloned the open reading frame of Danio rerio BiP (zebrafishBiP, Uniprot Q7SZD3) into a pTrcHis-A vector for heterologous expression in Escherichia coli. The open reading frame cloned excluded the N-terminal signal peptide and the highly acidic sequence of eight amino acids after the peptide signal to align expression with previously studied mammalian BiP from Mesocricetus auratus (golden hamster, Uniprot P07823). Following PCR amplification, enzymatic digestion, ligation, and bacterial transformation, colonies were screened via colony PCR and sequencing. One clone, B1, showed 99.73% identity with the Uniprot reference, as two missense mutations (Pro→Leu) were identified. Preliminary functional assays using the malachite green method confirmed ATPase activity of hamster BiP, paving the way to test if recombinant zfBiP is biochemically active. These results lay the foundation for comparative analyses of BiP functionality across species and its potential role in the endoplasmic reticulum proteostasis and protein disaggregation.
Fractioning macrocomponents of nannochloropsis oceanica by high-pressure homogenization, membrane processing, and ethanolic extraction
Publication . Cunha, Pedro; Carvalho, Bernardo; Kholany, Mariam; Cardoso, Helena; Pereira, Hugo; Varela, João
Multi-product biorefineries, which transform biomass feedstocks into multiple valuable bio-based products, are pivotal for transitioning from a fossil-based economy to a sustainable circular bioeconomy. This work proposes a processing pipeline for fractionating the macrocomponents of Nannochloropsis oceanica, which can serve as a basis for multi-product microalgae biorefineries. It consists of high-pressure homogenization (1200 bar, 1 cycle) to permeabilize the cells, and sequential membrane processing (0.2 µm dia-microfiltration followed by 100 kDa ultrafiltration) and ethanolic extraction (60 mL ethanol/g dry weight, 1 h) to fractionate the disrupted biomass. This biorefinery resulted in four final fractions: (1) enriched in water-soluble proteins (39.0 ± 2.8% w/w proteins; 10.7 ± 0.8% w/w carbohydrates); (2) remaining soluble components (5.7 ± 0.4% w/w proteins; 4.3 ± 0.9% w/w carbohydrates); (3) lipid-rich extract (62.4 ± 5.8% w/w lipids); and (4) non-extracted components (11.8 ± 4.5% w/w lipids), with mass recovery yields of 23.2 ± 2.1%, 6.9 ± 1.0%, 10.6 ± 1.9%, and 60.4 ± 4.1%, respectively. The ultrafiltration protein selectivity was not optimal, despite yielding a 2.6 times more concentrated fraction. Lipid extraction yield (35–60%) and purity (56–68%) were highly affected by the water content of the microfiltration retentate. Overall, 10.0 ± 0.9% of the proteins, 9.7 ± 1.8% of the carbohydrates, and 42.4 ± 13.4% of the lipids of N. oceanica were recovered in fractions 1, 2, and 3, respectively.
Vulnerable attachment style questionnaire: preliminary evidence for a revised factor structure among adolescents in residential care
Publication . Simão, Ana; Martins, Cátia; Bifulco, Antonia; Nunes, Cristina
Background/Objectives: The attachment framework has been used to understand individuals’ development and the emergence of difficulties in specific contexts and developmental stages. The Vulnerable Attachment Style Questionnaire (VASQ) is a brief self-report measure initially designed to assess adult attachment as a vulnerability factor for the development of depression. The present study aimed to examine the factor structure and psychometric properties of the VASQ in a sample of adolescents living in residential care and to provide preliminary evidence for a revised version of the instrument in this population. Methods: A total of 438 youths, aged 12 to 18 years (M = 15.34), completed the questionnaire. Data were randomly split to conduct independent exploratory and confirmatory factor analyses. Results: A three-factor model, consisting of two types of insecurity (ambivalent and avoidant) and a proximity-seeking dimension, emerged as the best-fitting solution. This revised structure involved removing several items while maintaining acceptable psychometric properties and meaningful associations with psychological adjustment. Concurrent validity was assessed by examining youth psychological adjustment, and positive correlations emerged as expected. Conclusions: The findings provide preliminary support for a shortened, restructured version of the VASQ for adolescents in residential care. Rather than confirming the original factorial structure, the results highlight the need to consider population-specific adaptations of the instrument. This version may have potential utility in clinical or intervention contexts and underscores the need to train institutional workers to develop competencies tailored to this population.
Evaluation of the chemical properties of tomato products enriched with plant-based ingredients
Publication . Ngameni Tchonkouang, Rose Daphnee; Martey, Dorcas Martekie; Gago, Custódia; Guerreiro, Adriana; Raposo, Sara; Rodrigues, Brígida; Vieira, Margarida; Antunes, Maria Dulce
Reformulating tomato-based products with beneficial plant-based ingredients is a promising approach for enhancing dietary quality. In this study, the chemical properties of reformulated tomato products—a juice and a sauce enriched with pea protein, olive powder, and tomato peel powder—were evaluated alongside the tomatoes used as raw material (cultivar ‘H1657’) to determine the changes occurring during their conversion into reformulated products. The chemical properties were assessed by analyzing lycopene, antioxidant capacity (by total phenolic content, DPPH, ABTS, and FRAP), sugars (glucose, fructose, and sucrose), and organic acids (citric, malic, ascorbic, and oxalic acids). The results showed that the fruit had the highest contents of glucose and fructose. Citric, malic, and oxalic acids were lower in the reformulated products than in the fruit sample, while ascorbic acid did not differ significantly. The sauce and fresh fruit exhibited the highest lycopene, ABTS, DPPH, and FRAP, whereas the juice had the lowest. Polyphenol content was highest in the sauce followed by the fruit and then the juice. The results suggest that incorporating plant-based ingredients into the sauce formulation can help compensate for nutrient losses that occur during tomato processing, making it a promising tomato-based product.