Browsing by Issue Date, starting with "2020-06"
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- Efficacy, Stability, and Safety Evaluation of New Polyphenolic Xanthones Towards Identification of Bioactive Compounds to Fight Skin PhotoagingPublication . Resende, Diana I. S. P.; Almeida, Mariana C.; Maciel, Bruna; Carmo, Helena; Lobo, José Sousa; Dal Pozzo, Carlotta; Cravo, Sara M.; Rosa, Gonçalo P.; Kane-Pagès, Aida; Barreto, Maria do Carmo; Almeida, Isabel F.; Sousa, Maria Emília de; Pinto, Madalena M. M.Antioxidants have long been used in the cosmetic industry to prevent skin photoaging, which is mediated by oxidative stress, making the search for new antioxidant compounds highly desirable in this field. Naturally occurring xanthones are polyphenolic compounds that can be found in microorganisms, fungi, lichens, and some higher plants. This class of polyphenols has a privileged scaffold that grants them several biological activities. We have previously identified simple oxygenated xanthones as promising antioxidants and disclosed as hit, 1,2-dihydroxyxanthone (1). Herein, we synthesized and studied the potential of xanthones with different polyoxygenated patterns as skin antiphotoaging ingredients. In the DPPH antioxidant assay, two newly synthesized derivatives showed IC₅₀ values in the same range as ascorbic acid. The synthesized xanthones were discovered to be excellent tyrosinase inhibitors and weak to moderate collagenase and elastase inhibitors but no activity was revealed against hyaluronidase. Their metal-chelating effect (FeCl₃ and CuCl₂) as well as their stability at different pH values were characterized to understand their potential to be used as future cosmetic active agents. Among the synthesized polyoxygenated xanthones, 1,2-dihydroxyxanthone (1) was reinforced as the most promising, exhibiting a dual ability to protect the skin against UV damage by combining antioxidant/metal-chelating properties with UV-filter capacity and revealed to be more stable in the pH range that is close to the pH of the skin. Lastly, the phototoxicity of 1,2-dihydroxyxanthone (1) was evaluated in a human keratinocyte cell line and no phototoxicity was observed in the concentration range tested.
- Occurrence of ESBL-producing Escherichia coli in soils subjected to livestock grazing in Azores archipelago : an environment-health pollution issue?Publication . Silva, Vanessa; Peixoto, Fernando; Parelho, Carolina Paula Furtado de Medeiros; Garcia, Patrícia; Rodrigues, Armindo; Silva, Adriana; Carvalho, Isabel; Pereira, José Eduardo; Igrejas, Gilberto; Poeta, Patrícia Alexandra Curado Quintas DinisAntibiotics are successful drugs used in human and animal therapy; however, they must be considered as environmental pollutants. This study aims to isolate and characterize the extended-spectrum β-lactamase (ESBL) producing Escherichia coli soil from Azores Archipelago subjected to livestock agricultural practices. Twenty-four soil samples were collected from three different pasture systems with different number of cattle heads, and from a control site. Antibiotic susceptibility method was performed by Kirby-Bauer disk diffusion method against 16 antibiotics, and the presence of genes encoding lactamases, antimicrobial resistance genes, virulence factors, and phylogenetic groups was determined by polymerase chain reaction (PCR). Nine ESBLs were recovered from the three grazing sites, and all isolates presented the beta-lactamase genes blaCTX-M-3 and blaSHV. E. coli isolates were resistance to tetracycline and streptomycin and harbored the tetB, strA, and strB genes. One isolate also showed resistance to sulfonamides, and the genes sul1 and sul2 were detected. The isolates were grouped into the following phylogenic groups: B1 (n = 6), D (n = 2), and A (n = 1). The presence of antibiotics and resistance genes in soils may be the source to the development of antimicrobial resistance, which may have negative consequences in human and animal health.
- Population expansion of the invasive Pomacentridae Chromis limbata (Valenciennes, 1833) in Southern Brazilian coast: long-term monitoring, fundamental niche availability and new recordsPublication . Anderson, Antônio B.; Silva, Jodir Pereira da; Sorvilo, Raquel; Francini, Carlo Leopoldo B.; Floeter, Sergio R.; Barreiros, João P.Human-mediated species invasions are recognized as a leading cause of global biotic homogenization and extinction. Studies on colonization events since early stages, establishment of new populations and range extension are scarce because of their rarity, difficult detection and monitoring. Chromis limbata is a reef-associated and non-migratory marine fish from the family Pomacentridae found in depths ranging between 3 and 45 m. The original distribution of the species encompassed exclusively the eastern Atlantic, including the Azores, Madeira and the Canary Islands. It is also commonly reported from West Africa between Senegal and Pointe Noire, Congo. In 2008, vagrant individuals of C. limbata were recorded off the east coast of Santa Catarina Island, South Brazil (27° 41' 44″ S, 48° 27' 53″ W). This study evaluated the increasing densities of C. limbata populations in Santa Catarina State shoreline. Two recent expansions, northwards to São Paulo State and southwards to Rio Grande do Sul State, are discussed, and a niche model of maximum entropy (MaxEnt) was performed to evaluate suitable C. limbata habitats. Brazilian populations are established and significantly increasing in most sites where the species has been detected. The distributional boundaries predicted by the model are clearly wider than their known range of occurrence, evidencing environmental suitability in both hemispheres from areas where the species still does not occur. Ecological processes such as competition, predation and specially habitat selectivity may regulate their populations and overall distribution range. A long-term monitoring programme and population genetics studies are necessary for a better understanding of this invasion and its consequences to natural communities.
- Climate-driven vicariance and long-distance dispersal explain the Rand Flora pattern in the liverwort Exormotheca pustulosa (Marchantiophyta)Publication . Rodrigues, Ana S. B.; Martins, Anabela; Garcia, César Augusto; Sérgio, Cecília; Porley, Ron; Fontinha, Susana; González-Mancebo, Juana M.; Gabriel, Rosalina; Phephu, Nonkululo; Van Roy, Jacques; Dirkse, Gerard; Long, David; Stech, Michael; Patiño, Jairo; Sim-Sim, ManuelaThe ‘Rand flora’ is a biogeographical disjunction which refers to plant lineages occurring at the margins of the African continent and neighbouring oceanic archipelagos. Here, we tested whether the phylogeographical pattern of Exormotheca pustulosa Mitt. was the result of vicariance induced by past climatic changes or the outcome of a series of recent long-distance dispersal events. Two chloroplast markers (rps4-trnF region and psbA-trnH spacer) and one nuclear marker (ITS2) were analysed. Phylogenetic and phylogeographical relationships were inferred as well as divergence time estimates and ancestral areas. Exormotheca possibly originated in Eastern Africa during the Late Oligocene/Early Miocene while Exormotheca putulosa diversified during the Late Miocene. Three main E. pustulosa groups were found: the northern Macaronesia/Western Mediterranean, the South Africa/Saint Helena and the Cape Verde groups. The major splits among these groups occurred during the Late Miocene/Pliocene; diversification was recent, dating back to the Pleistocene. Climate-driven vicariance and subsequent long-distance dispersal events may have shaped the current disjunct distribution of E. pustulosa that corresponds to the Rand Flora pattern. Colonization of Macaronesia seems to have occurred twice by two independent lineages. The evolutionary history of E. pustulosa populations of Cape Verde warrants further study.
- Natural Compounds : A Dynamic Field of ApplicationsPublication . Seca, Ana M. L.; Moujir, Laila M.Nature represents an amazing source of inspiration since it produces a great diversity of natural compounds selected by evolution, which exhibit multiple biological activities and applications. A large and very active research field is dedicated to identifying biosynthesized compounds, to improve/develop new methodologies to produce/reuse natural compounds and to assess their potential for pharmaceutical, cosmetic and food industries, among others, and also to understand their mechanism of action. Here, the main results presented in each work are highlighted. The applications suggested are mostly related to pharmacological uses and involve mainly pure natural compounds and essential oils. These works are significant contributions and reinforce the dynamic field of natural products applications.
- Using a space-for-time approach to select the best biodiversity-based indicators to assess the effects of aridity on Mediterranean drylandsPublication . Wendt, Clara Frasconi; Nunes, Alice; Verble, Robin; Santini, Giacomo; Boieiro, Mário; Branquinho, CristinaMediterranean drylands are particularly vulnerable to predicted increases in aridity which are expected to have negative consequences for biodiversity. To understand the effects of climate change on ecosystems, a framework for the selection of indicators based on the essential biodiversity variables (EBV) was proposed. In this framework, a functional approach has been suggested because functional traits have shown to be sensitive to small-scale environmental changes. Additionally, functional traits are also associated with ecosystem-limiting processes. In this context, we used ants as ecological indicators, as they are functionally important and respond in a measurable way to environmental changes. We identify which biodiversity-based indicators (e.g., taxonomic, single-trait and multi-trait indices) help track changes in Mediterranean drylands; for this, we used a space-for-time substitution climatic gradient in the western Mediterranean. Ants were sampled along an aridity gradient and identified to species level. Four continuous and seven categorical traits were measured or retrieved from literature. Continuous traits included Weber’s length, which is indicative for body length, head length, eye length and femur length; categorical traits were diet, behavioral dominance, daily activity, nest preference, mound presence, worker polymorphism and foraging strategy. We calculated taxonomic, functional structure and single- and multi-trait functional diversity indices and correlated them with aridity. We found that ant taxonomic and multi-trait functional diversity were maintained along the aridity gradient. Despite maintenance of species and functional diversity along the gradient, ant functional structure responded to aridity with increases in mean trait values of Weber’s length, eye length and femur length in the drier part of the gradient. Under wetter conditions, we found the highest proportion of ants with a seed-based diet, reflecting a potential increase in resource quantity. We observed a change in foraging strategy from group to individual as aridity increased. In conclusion, with a space-for-time substitution climatic gradient, this study shows the potential role of aridity as an environmental driver of ant trait values. These results highlight the value of ants and functional traits as indicators to track the effects of climate change on ecosystems. Finally, this study represents a starting point to monitor important species traits in the context of EBV and to use them as indicators to track the effects of aridity on Mediterranean dryland ecosystems.
- O futuro começa aqui, na Faculdade de Ciências Sociais e Humanas!Publication . Gil, Ana Cristina Correia, dir.; Fialho, Adolfo Fernando da Fonte, ed.
- Ecosystem services mapping and assessment for policy- and decision-making : Lessons learned from a comparative analysis of European case studiesPublication . Geneletti, Davide; Esmail, Blal Adem; Cortinovis, Chiara; Arany, Ildikó; Balzan, Mario; van Beukering, Pieter; Bicking, Sabine; Borges, Paulo A. V.; Borisova, Bilyana; Broekx, Steven; Burkhard, Benjamin; Gil, Artur José Freire; Inghe, Ola; Kopperoinen, Leena; Kruse, Marion; Liekens, Inge; Lowicki, Damian; Mizgajski, Andrzej; Mulder, Sara; Nedkov, Stoyan; Ostergard, Hannah; Picanço, Ana; Ruskule, Anda; Santos-Martín, Fernando; Sieber, Ina M.; Svensson, Johan; Vačkářů, Dava; Veidemane, KristinaThis paper analyses and compares a set of case studies on ecosystem services (ES) mapping and assessment with the purpose of formulating lessons learned and recommendations. Fourteen case studies were selected during the EU Horizon 2020 “Coordination and Support Action” ESMERALDA to represent different policy- and decision-making processes throughout the European Union, across a wide range of themes, biomes and scales. The analysis is based on a framework that addresses the key steps of an ES mapping and assessment process, namely policy questions, stakeholder identification and involvement, application of mapping and assessment methods, dissemination and communication and implementation. The analysis revealed that most case studies were policy-orientated or gave explicit suggestions for policy implementation in different contexts, including urban, rural and natural areas. Amongst the findings, the importance of starting stakeholder engagement early in the process was confirmed in order to generate interest and confidence in the project and to increase their willingness to cooperate. Concerning mapping and assessment methods, it was found that the integration of methods and results is essential for providing a comprehensive overview from different perspectives (e.g. social, economic). Finally, lessons learned for effective implementation of ES mapping and assessment results are presented and discussed.
- Limited effect of management on apple pollination : a case study from an oceanic IslandPublication . Pardo, Adara; Lopes, David João Horta; Fierro, Natalia; Borges, Paulo A. V.Intensive agricultural practices leading to habitat degradation represent a major threat to pollinators. Diverse management practices are expected to influence wild pollinator abundance and richness on farms, although their effect in perennial crops is still unclear. In this study, we assessed the impact of management on apple (Malus domestica) pollination on an oceanic island, by comparing conventional (with and without herbicide application) and organic apple orchards. Pollinator visitation and pan trap surveys were carried out in six apple orchards in Terceira Island (Azores) and the landscape composition surrounding orchards was characterized. We also quantified fruit set, seed set and apple weight. We found no significant effect of management on insect visitation rates, whereas there was a negative association with increasing surrounding agricultural land. In contrast, management had an effect on species abundance, richness and diversity at the orchard level. Conventional orchards without herbicides showed higher abundance than the rest, but lower richness and diversity than conventional orchards with herbicides. Management had an effect on fruit set, but not on seed set or fruit weight. Our results suggest that management alone is insufficient for the overall improvement of apple pollination on an oceanic island, while landscape composition may play a relevant role.
- Filosofia para crianças : a (im)possibilidade de lhe chamar outras coisasPublication . Costa Carvalho, MagdaApresentamos um trabalho composto por um conjunto de reflexões nascidas em tempos e espaços distintos. A maior parte dos capítulos retoma textos já publicados, mas que foram repensados e reescritos a partir do que hoje vemos. Outros só agora se tornam dia. Paralelamente à escolha dos textos, à depuração da escrita e ao afinamento da redação, um outro exercício emergiu: pensar cada capítulo como evento de um processo cujo dinamismo próprio não se deixa fixar. Os textos mostraram-se, então, como inscrições provisórias, fotografias que captaram certos contornos de uma continuidade, formas instantâneas fotografadas numa transição permanente. O mesmo é dizer que, tendo nascido em tempos distintos e com espaços próprios, os textos são ações em processo, rastos de uma mudança: o estar-em-viagem que foi emergindo.