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Valorization of the medicinal endemism Limonium algarvense Erben by biotechnological tools
Publication . Lescano, Leonardo Jácome; Rodrigues, Maria João; Pereira, Catarina Guerreiro
O presente estudo teve como principal objetivo investigar o potencial biotecnológico de Limonium algarvense, uma espécie halófita endémica do sudoeste da Península Ibérica, com enfoque na avaliação do potencial cosmético dos seus compostos bioativos. A investigação foi desenvolvida em três eixos principais: (1) caracterização fitoquímica e avaliação da atividade biológica de extratos obtidos a partir de sementes; (2) estabelecimento e elicitação de culturas de calos para produção de metabolitos secundários; e (3) desenvolvimento de protocolos de propagação in vitro para fins de conservação. Extratos de sementes como fonte de ingredientes cosméticos Embora as flores e folhas de L. algarvense tenham sido previamente estudadas, este trabalho constitui o primeiro relato sobre o potencial cosmético das suas sementes. Foram obtidos extratos aquosos, etanólicos, acetónicos e de acetato de etilo mediante extração assistida por ultrassons (1:40 p/v, 30 min). Os extratos foram avaliados quanto às suas atividades antioxidante, quelante de metais, inibitória de enzimas dermatologicamente relevantes (tirosinase, lipase e elastase) e citotoxicidade. Os resultados demonstraram que o extrato aquoso apresentou a maior atividade antioxidante, com valores de EC₅₀ de 0,296 mg/mL (DPPH), 0,506 mg/mL (ABTS) e 0,230 mg/mL (FRAP), além de significativa atividade quelante de cobre (EC₅₀ = 0,678 mg/mL). No que respeita à inibição enzimática, apenas o extrato aquoso demonstrou capacidade inibitória significativa sobre a tirosinase (EC₅₀ = 0,450 mg/mL), enzima-chave no processo de hiperpigmentação cutânea. Ensaios de citotoxicidade demonstraram que os extratos de sementes não apresentaram toxicidade significativa. As linhas celulares HepG2, RAW 264.7 e S17 mantiveram uma viabilidade superior a 80% quando tratadas com 100 μg/mL de extrato.
A análise fitoquímica revelou que o extrato aquoso continha os teores mais elevados de fenóis totais (115,5 mg equivalentes de ácido gálico/g de extrato seco) e taninos condensados (76,3 mg equivalentes de catequina/g de extrato seco), enquanto o extrato etanólico apresentou maior conteúdo de flavonoides (62,3 mg equivalentes de quercetina/g de extrato seco). A análise metabolómica por LC-ESI-HRMS/MS identificou 42 compostos no extrato aquoso, sendo predominantes flavonoides como apigenina-7-O-glucuronídeo, quercetina e miricetina, bem como aminoácidos como a prolina. Esta composição justifica as atividades biológicas observadas, uma vez que os flavonoides são conhecidos pelas suas propriedades antioxidantes e inibitórias da tirosinase. Estabelecimento e elicitação de culturas de calos Com o objetivo de desenvolver uma alternativa sustentável à extração convencional, foram estabelecidas culturas de calos a partir de explantes foliares em meio MS suplementado com 1 mg/L de picloram. A curva de crescimento celular apresentou uma fase exponencial entre 0–28 dias, com taxa específica de crescimento (μ) de 0,04 g/dia e tempo de duplicação (td) de 16,43 dias.
A elicitação com extrato de levedura (YE 50 mg/L) promoveu um aumento significativo na acumulação de fenóis totais (25,6 mg equivalentes de ácido gálico/g peso seco), flavonoides (12,5 mg equivalentes de quercetina/g peso seco) e proteínas solúveis (30,04 mg/g peso seco). Por outro lado, o ácido salicílico (SA 100 μM) induziu uma maior acumulação de prolina (8,61 μmol/g peso seco). A análise metabolómica dos calos elicitados revelou a presença de compostos de interesse cosmético, incluindo ácidos hidroxibenzóicos glicosilados e derivados de cumarinas, que não foram detetados nos calos não elicitados (controlo). Estes resultados destacam o potencial da elicitação como ferramenta para modular o perfil metabólico de L. algarvense. Propagação in vitro e aclimatização Para fins de conservação, foram desenvolvidos protocolos de micropropagação utilizando meristemas apicais como explantes. O meio MS suplementado com 2,5 mg/L de KIN e 0,1 mg/L de NAA promoveu a multiplicação de rebentos com morfologia normal. O enraizamento foi otimizado mediante ensaios com diferentes concentrações de meio MS (integral, ½ e ¼) suplementado com carvão ativado (1 g/L). Os melhores resultados foram obtidos no meio MS integral, com 34,76% de enraizamento após 48 dias de cultivo. No entanto, a fase de aclimatização apresentou uma baixa taxa de sobrevivência (7,69%), evidenciando a necessidade de otimizar as condições de transição para o ambiente ex vitro. Conclusões e perspectivas
Os resultados deste trabalho demonstram que:
1. As sementes de L. algarvense constituem uma fonte promissora de compostos bioativos com potencial aplicação em cosméticos, particularmente em formulações antioxidantes e despigmentantes.
2. A elicitação de culturas de calos representa uma estratégia eficaz para aumentar a produção de metabólitos secundários de interesse, reduzindo a pressão sobre populações naturais desta espécie ameaçada.
3. A micropropagação in vitro mostra-se viável para fins de conservação, embora seja necessário otimizar os protocolos de aclimatização.
Como perspetivas futuras, recomenda-se: (i) investigar o potencial dos compostos identificados em modelos celulares de pele humana; (ii) otimizar sistemas de cultivo em biorreatores para produção em larga escala; e (iii) testar bioestimulantes durante a aclimatização para melhorar as taxas de sobrevivência.
Este estudo contribui significativamente para a valorização sustentável de L. algarvense, integrando abordagens de química de produtos naturais e biotecnologia vegetal, com potenciais aplicações na indústria cosmética.
Language assessment and placement: linguistic and computational approaches in developmentaleducation
Publication . Da Corte, Miguel; Baptista, Jorge
This thesis addresses the challenges of language assessment and placement in Developmental Education (DevEd) for native English (L1) speakers, stemming from the limitations of automated systems such as Accuplacer. At Tulsa Community College (TCC), where the study was conducted, writing proficiency is assessed through Accuplacer, and students not deemed college-ready are placed in DevEd courses to strengthen their skills before advancing to collegelevel coursework. This thesis draws on nine peer-reviewed papers organized into four thematic sections and integrates Corpus Linguistics, Machine Learning (ML), and Natural Language Processing (NLP) to address these limitations. Section 1 lays the groundwork by mapping the linguistic landscape of developing writers through an annotation framework with 21 lexical, syntactic, and discourse features tailored to the DevEd context (DES). This framework is tested, refined, and applied to a newly created and publicly documented corpus of DevEd writing samples. The framework’s adaptability is further demonstrated through a cross-linguistic extension to Spanish. Building on this foundation, Section 2 integrates the 21 DES features with 436 linguistic features automatically extracted from NLP tools (Coh-Metrix, CTAP) to create a richer, more comprehensive feature set. This set is used to train and test supervised ML models against a human-produced gold standard, evaluating whether these models can replicate, and potentially improve upon, Accuplacer’s placement accuracy. The findings from these ML classification experiments lead to the questions of fairness and validity, which are addressed in Section 3. This section examines whether Accuplacer’s classifications reflect students’ actual
writing performance and whether placement outcomes are equitable across different gender and race groups. Finally, Section 4 investigates the use of Large Language Models (LLMs) as complementary tools for writing placement. Through prompt engineering and comparative evaluation, this section explores how LLMs can offer adaptive, linguistically sensitive, and more transparent alternatives to current automated classification systems. In the conclusion, this thesis synthesizes these findings, outlining key contributions, broader implications, and future research directions, all of which advocate for more linguistically informed placement practices.
Phytochemical characterization of euphorbia peplis extracts and their antioxidant, enzyme inhibitory, and cytotoxic activities: an integrated experimental and in silico study
Publication . Yagi, Sakina; Elhawary, Esraa A.; Eldahshna, Omayma A.; Singab, Abdel Nasser B.; Cetiz, Mehmet Veysi; Uba, Abdullahi Ibrahim; Yapıcı, Ismail; Gulcin, Ilhami; Fernandes, Eliana; Custódio, Luísa; Rodrigues, Maria João; Yildiztugay, Evren; Zengin, Gokhan
Euphorbia members (Euphorbiaceae) are valuable sources of lead compounds for potential drug discovery. This study was conducted to evaluate, for the first time, the phytoconstituents, antioxidant capacity, enzyme inhibitory, and cytotoxic properties of E. peplis. Extracts were prepared from the aerial parts using ethyl acetate (EtOAc), ethanol (EtOH), 70% EtOH, and water. Results showed that the 70% EtOH and EtOH extracts contained the highest levels of total phenolics (68.12mg GAE/g) and flavonoids (45.49mg RE/g). UPLC-ESI-MSn analysis revealed a variety of phytochemicals, including flavonoids, cinnamic acid derivatives, tannins, triterpenoids, and saponins, with 24 metabolites tentatively identified. PCA grouped these metabolites into three clusters, and their distribution was visualized with a heatmap. Polar extracts demonstrated strong antioxidant activity, with the 70% EtOH extract showing the highest values in most assays (DPPH=385.50mg TE/g; ABTS=466.31mg TE/g; CUPRAC=439.95mg TE/g; FRAP=305.07mg TE/g; PBD=2.45mmol TE/g). The EtOH and EtOAc extracts exhibited the strongest anti-acetylcholinesterase (2.83mg GALAE/mg) and anti-butyrylcholinesterase (2.18mg GALAE/mg) activities, respectively. Both the 70% EtOH and EtOH extracts showed the best anti-tyrosinase effects (54.40 and 53.39mg KAE/g; p≥0.05). The EtOAc extract was more toxic toward SHSY5Y cells, with a viability of 4.31%, compared to 8.18% in normal KEK293 cells. Network pharmacology identified 11 common targets for E. peplis metabolites, with AKT1, EGFR, GSK3B, ESR1/ESR2, and CCND1 serving as key hubs. Pathway enrichment analysis highlighted PI3K-Akt, EGFR, and hormone-related pathways. Docking and molecular dynamics simulations confirmed stable multi-target binding. These findings suggest that E. peplis could be a promising source of antioxidants and compounds with potential anticancer and enzyme-inhibitory activities relevant to human diseases.
Waste literacy among portuguese first-year tertiary students after compulsory environmental education
Publication . Spínola, Hélder; Silva Fernandes, Maria Jacinta; Sousa, Cátia; Oliveira Campos, Clarice; Mourato, Sandra; Heleno, Lizete; Ventura, Maria Anunciação Mateus; Caeiro, Sandra; Bacelar-Nicolau, Paula; Mapar, Mahsa; Azeiteiro, Ulisses M.; Guimarães, Sandra C.; Rodrigues, Liliana; Carreira, Sílvia Mateus; Martins, Rute; Quadros, Sílvia
Waste management is essential for addressing local and global environmental challenges. Failure to manage waste effectively results in several consequences, including environmental degradation, public health risks, and economic costs. Besides the need for adequate and up-to-date waste management systems, citizens’ cooperation is crucial to achieving sustainable waste management in any community, which depends on their waste literacy levels, comprising the knowledge, attitudes, and behaviours required. This study assessed waste literacy among students completing compulsory education in Portugal to provide evidence regarding the outcomes of environmental education policies related to waste management. A representative sample of 1506 freshmen students was surveyed at the start of their undergraduate programmes. An online questionnaire was administered to the sample and the data were analyzed using statistical tests for assessing the influential factors associated with students’ waste knowledge, attitudes and behaviours. Results show that, on average, students demonstrated good levels of knowledge and practices on waste management, together with a predominantly ecocentric worldview. A higher performance in waste management knowledge and practices was observed among younger students, with higher grades and higher paternal educational attainment. Besides these variables, best practices were significantly more prevalent among those with a higher participation in environmental activities and holding membership in environmental organizations. The findings suggest that upon completing compulsory education in Portugal, students display generally high levels of waste literacy, while also revealing specific gaps in knowledge and practices that warrant further educational attention. The study identifies these areas for improvement, highlighting the potential value of more practical, participatory and community-based approaches to waste education.
The rio grande rise: current knowledge and future frontiers for deep-sea science, mineral resources and governance
Publication . Jovane, Luigi; Ulsen, Carina; Galante, Douglas; Bernardini, Simone; Bergo, Natascha Menezes; Braga, Elisabete de Santis; Brandini, Frederico P.; Carrion, Ronaldo; Castro, David Lopes de; Constantino, Renata R.; Hassan, Muhammad Bin; Janasi, Valdecir de Assis; Jeck, Izabel King; Junior, Marco Antonio Couto; de Oliveira Júnior, Luciano; Lima, Fabiola A.; Marques, Simone; Massola, Gustavo M.; Mestre, Nélia; Mohriak, Webster; Monlevade, Eduardo F.; Oliveira, Carina Costa de; Pellizari, Vivian Helena; Portes, Marcelo Cecconi; Praxedes, Adriane G. P.; Rodrigues, Fabio; Rodrigues, Lucas C. V.; Sanz, Francisco Javier González; Silveira, Ilson C. A. da; Soto, Jules M. R.; Souza-Neto, Pedro Walfir; Sumida, Paulo Y. G.; Tagliaro, Gabriel T.; Silva, Solange Teles da; Turra, Alexander; Santos, Roberto Ventura; Yamamoto, Marcio; Mello, Sidney L. M.
The Rio Grande Rise (RGR) is the largest oceanic plateau in the South Atlantic and represents a key natural laboratory for understanding oceanic plateau formation, deep-sea circulation, ecosystem functioning, and ferromanganese crust development. This study presents a critical synthesis of current scientific knowledge on the RGR, integrating geological, geophysical, oceanographic, biological, and geochemical evidence published over the last two decades. Geophysical data reveal a complex tectono-magmatic evolution involving Late Cretaceous plume-related volcanism, crustal thickening, rifting, and subsequent subsidence. The structural framework of the plateau is dominated by the Cruzeiro do Sul Rift, which plays a central role in controlling sedimentation, magmatism, and seawater circulation. Oceanographic studies demonstrate that the interaction between the southern branch of the South Equatorial Current and the complex topography of the RGR generates intense internal tides and bottom currents, strongly influencing sediment transport and benthic habitats. Biological investigations indicate that the RGR hosts diverse deep-sea communities, including sponge grounds, cold-water corals, and associated fauna, whose distribution is tightly linked to geomorphology and hydrodynamics. Ferromanganese crusts occurring on the plateau preserve valuable geochemical records of oceanographic and redox conditions, although their spatial distribution, thickness, and metal budgets remain incompletely constrained. Despite major advances, significant knowledge gaps persist regarding crustal structure, sedimentary evolution, ecosystem functioning, and mineral formation processes. This review highlights these uncertainties and outlines research priorities necessary to improve understanding of oceanic plateaus and deep-sea systems in the South Atlantic.