Browsing by Issue Date, starting with "2021-12"
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- From settlers to subspecies: genetic differentiation in Commerson’s dolphins between South America and the Kerguelen IslandsPublication . Kraft, Sebastian; Pérez-Alvarez, MJosé; Olavarría, Carlos; Moraga, Rodrigo; Baker, C. Scott; Steel, Debbie; Tixier, Paul; Guinet, Christophe; Viricel, Amelia; Brickle, Paul; Costa, Marina; Crespo, Enrique; Durante, Cristian; Loizaga, Rocio; Poulin, ElieCommerson’s dolphins (Cephalorhynchus commersonii) are separated into the subspecies C. c. commersonii, found along southern South America (SA) and the Falkland Islands/Islas Malvinas (FI/IM), and C. c. kerguelenensis, restricted to the subantarctic Kerguelen Islands (KI). Following the dispersal model proposed for the genus, the latter is thought to have originated from SA after a long-distance dispersal event. To evaluate this biogeographic scenario, a distribution-wide, balanced sampling of mitochondrial DNA (mtDNA) control region sequences was designed. New tissue samples from southern Chile, Argentina, FI/IM, and KI were added to published sequences from SA and KI, for a total of 256 samples. Genetic diversity indices, genetic and phylogeographic structure, and migration rates were calculated. One haplotype was shared between subspecies, with which all haplotypes of C. c. kerguelenensis formed a distinct group in the haplotype network. A new haplotype for C. c. kerguelenensis is reported. Differentiation in haplotype frequencies was found among localities within the distribution of C. c. commersonii, yet the phylogeographic signal was only statistically significant between subspecies. Coalescent-based historical gene flow estimations indicated migration between the northern and southern portions of the species’ range in SA as well as between SA and the FI/IM, but not between these and the KI. The net nucleotide divergence between dolphins from SA and the FI/IM was lower than the recommended threshold value suggested for delimiting subspecies, unlike that found between C. c. commersonii and C. c. kerguelenensis. The results are consistent with the model of post-glacial colonization of KI by South American C. commersonii, followed by an ongoing divergence process and subspecies status. Thus, C. c. kerguelenensis may represent the most recent diversification step of Cephalorhynchus, where isolation from their source population is driving a process of incipient speciation.
- Predicted regime shift in the seagrass ecosystem of the Gulf of Arguin driven by climate changePublication . Chefaoui, Rosa M.; Duarte, Carlos M.; Tavares, Ana I; Frade, Duarte; Sidi Cheikh, M.A.; Abdoull Ba, M.; Serrao, EsterThe Banc d′Arguin is a marine ecosystem of global conservation significance, the largest bird sanctuary of western Africa, supported by one of the most extensive seagrass beds in the world composed by three seagrass species, two temperate near their southern limit (Zostera noltei and Cymodocea nodosa) and one tropical at its northern limit (Halodule wrightii). Here we predict the fate of this seagrass ecosystem under climate change scenarios during the 21st century, using species distribution models and sea level rise estimates. We forecast a probable decline in total seagrass area of 3340 Km2 (78%) by 2100, involving the loss of both temperate seagrasses (Z. noltei, C. nodosa), the foundational ecosystem components. By 2050, only the tropical species (H. wrightii) would remain, which forms thin and sparse shallow stands functionally distinct from the previous tall dense meadows that span wider vertical ranges. Intertidal flats, the essential bird foraging habitats, would become unvegetated and also suffer a major reduction in area (114 km2 by 2050, 587 km2 by 2100). The large projected loss of foundational seagrass species portends a collapse of major ecosystem functions with profound impacts on biodiversity, fishery resources and ecosystem services.
- Unravelling the taphonomic stories of bird bones from the middle pleistocene layer VIII of Grotte Vaufrey, FrancePublication . Rufà, Anna; Laroulandie, VéroniqueIn recent years, several studies have significantly changed our knowledge concerning the use of birds by Neanderthals. However, what remains to be clarified is the geographical and chronological variability of this human behaviour. The present case study provides new information on this topic/debate. The Grotte Vaufrey was discovered during the 1930s and was excavated during different periods. Work carried out by J.-P. Rigaud during the 1980s motivated many multidisciplinary studies in the cave, but accurate studies were not focused on avian remains. In this work, we provide new data on the bird remains from layer VIII (MIS 7), which is the richest among all the sequences and which has an important Mousterian component. Corvids are predominant in the assemblage and are associated with medium-sized birds and small Passeriformes, among others. Most of the remains present modern fractures, which hinder taphonomic interpretation. However, some alterations associated with raptor or mammalian carnivore activities, together with the anatomical representation and age profile, suggest a non-human accumulation of the majority of the bird remains, especially in the case of corvids that naturally died in the cave. However, at least some bones show evidence of anthropic activity, suggesting the occasional use of large- and medium-sized birds by human populations.
- 108P PICTuRE: Real-world treatment pathways in stage III non-small cell lung cancer in PortugalPublication . Teixeira, M.E.; Oliveira Fernandes, M.G.; Ferreira, M.L.S.; Estevinho, F.; Lopes, J.A.; Araújo, A.; Pacheco Figueiredo, M.M.; Barradas Lopes, M.L.; Lopes, M.; Brito, U.; Barroso, A.M.P.; Camacho, C.; Parente, B.; Felizardo, M.M.; Meleiro, A.; Bernardo, M.; Bernardo, F.; Figueiredo, S.Stage III NSCLC is a heterogeneous and complex setting that requires multimodal management. Recent advances in modern medicine led to the implementation of immuno-oncology (IO) into clinical practice. PICTuRE aims to assess the clinical management and the IO impact on clinical outcomes in stage III NSCLC patients (pts).
- Energy content of anchovy and sardine using surrogate calorimetry methodsPublication . Campanini, Claudia; Albo Puigserver, Marta; Gérez, Sara; Lloret-Lloret, Elena; Giménez, Joan; Pennino, Maria Grazia; Bellido, José María; Colmenero, Ana I.; Coll, MartaEuropean anchovy (Engraulis encrasicolus) and sardine (Sardina pilchardus) are crucial species for the marine ecosystem of the Northwestern Mediterranean Sea. They account for a high percentage of fish landings and they represent an important economic income for the fishery sector. Concerns over their stock status are rising in recent years as biomass, growth, reproductive capacity, and body condition of both species are declining, with latitudinal variations. Therefore, there is an urgent need for a body condition monitoring scheme. Energy storage variability has important implications for both fish recruitment and population structure. Direct condition indices, such as energy density (ED) with bomb calorimetry, are highly reliable for measuring the energy content, but time-consuming. Alternatively, fatmeter analysis and relative condition index (Kn) have been proposed as effective indirect methods. The aim of this study is to test the application of fatmeter as a surrogate of bomb calorimetry to infer the energy content of sardine and anchovy. To validate its use, fatmeter values were compared with both ED and Kn values. Individuals of both species were sampled monthly for a year in order to assess seasonal variations in energy content. Our results highlight that fatmeter measurements are strongly correlated with calorimetry ED for sardine, while a weaker but significant correlation was found for anchovy. The observed differences between the two species are related to their breeding strategies. Based on this study, Kn cannot be considered a good proxy of the energy density of sardine, in particular during the resting period. By contrast, fatmeter analysis appears to be a faster and suitable method to evaluate the energy content of both species routinely. In addition, we provide a linear model to infer ED from fatmeter values for both small pelagic fish. Eventually, these findings could be used to implement body condition monitoring protocols and boost continuous large-scale monitoring.
- A poda de citrinosPublication . Matias, Pedro; Duarte, AmilcarA produção citrícola apresenta grande importância na agricultura, a nível nacional e sobretudo na região do Algarve. Em 2020, a superfície cultivada de citrinos era 21 481 ha e a produção total de citrinos no Algarve foi 87% da produção total nacional, que atingiu 422 929 t (INE, 2021). Nas últimas décadas a citricultura tem passado por um processo de modernização tecnológica que permitiu aumentar a produtividade e a qualidade do fruto. Mesmo assim, permanecem alguns problemas, entre os quais, a alternância de produções e o aparecimento de defeitos epidérmicos de vários tipos, que podem ter origem em fatores bióticos ou fisiológicos (Azevedo et al., 2013; Pacheco e Duarte, 2016). A poda é uma prática cultural que pode surgir como estratégia para mitigar estes problemas e otimizar a produção de citrinos em vários outros aspetos (Matias et al., 2020). Esta, é uma operação que consiste, essencialmente, na remoção de órgãos vegetativos, modificando o desenvolvimento e a forma natural da árvore e afetando o seu comportamento fisiológico (Rodríguez e Villalba, 1998).
- Immune status and hepatic antioxidant capacity of Gilthead Seabream Sparus aurata juveniles fed yeast and microalga derived β-glucansPublication . Reis, Bruno; Gonçalves, Ana Teresa; Santos, Paulo; Sardinha, Manuel; Conceição, Luís E. C.; Serradeiro, Renata; Pérez-Sánchez, Jaume; Calduch-Giner, Josep; Schmid-Staiger, Ulrike; Frick, Konstantin; Dias, Jorge; Costas, BenjamínThis work aimed to evaluate the effects of dietary supplementation with β-glucans extracted from yeast (Saccharomyces cerevisiae) and microalga (Phaeodactylum tricornutum) on gene expression, oxidative stress biomarkers and plasma immune parameters in gilthead seabream (Sparus aurata) juveniles. A practical commercial diet was used as the control (CTRL), and three others based on CTRL were further supplemented with different β-glucan extracts. One was derived from S. cerevisiae (diet MG) and two different extracts of 21% and 37% P. tricornutum-derived β-glucans (defined as Phaeo21 and Phaeo37), to give a final 0.06% β-glucan dietary concentration. Quadruplicate groups of 95 gilthead seabream (initial body weight: 4.1 ± 0.1 g) were fed to satiation three times a day for 8 weeks in a pulse-feeding regimen, with experimental diets intercalated with the CTRL dietary treatment every 2 weeks. After 8 weeks of feeding, all groups showed equal growth performance and no changes were found in plasma innate immune status. Nonetheless, fish groups fed β-glucans supplemented diets showed an improved anti-oxidant status compared to those fed CTRL at both sampling points (i.e., 2 and 8 weeks). The intestinal gene expression analysis highlighted the immunomodulatory role of Phaeo37 diet after 8 weeks, inducing an immune tolerance effect in gilthead seabream intestine, and a general down-regulation of immune-related gene expression. In conclusion, the results suggest that the dietary pulse administration of a P. tricornutum 37% enriched-β-glucans extract might be used as a counter-measure in a context of gut inflammation, due to its immune-tolerant and anti-oxidative effects.
- Citrinos na Dieta Mediterrânica: frutos com sumo e com históriaPublication . Matias, Pedro; Duarte, Beatriz; Duarte, AmílcarOs citrinos são muito importantes para as populações mediterrânicas, do ponto de vista económico e social. A diversidade dos citrinos é encantadora, tal como a história da sua chegada à Europa. São originários da Ásia, mas existem no Mediterrâneo desde a Grécia Antiga. Atualmente, “tropeçamos” neles: plantamo-los nos nossos quintais, nas ruas das nossas cidades, em parques e jardins e produzimo-los em pomares com elevada qualidade. Usamos os seus frutos em muitos pratos que confecionamos e usufruímos dos seus enormes benefícios para a saúde.
- New insights into benzo[⍺]pyrene osteotoxicity in zebrafishPublication . Tarasco, Marco; Gavaia, Paulo; Bensimon-Brito, Anabela; Cardeira-da-Silva, João; Ramkumar, Srinath; Cordelières, Fabrice P.; Günther, Stefan; Bebianno, Maria J.; Stainier, Didier Y.R.; Cancela, M. Leonor; Laizé, VincentPersistent and ubiquitous organic pollutants, such as the polycyclic aromatic hydrocarbon benzo[⍺]pyrene (BaP), represent a major threat to aquatic organisms and human health. Beside some well-documented adverse effects on the development and reproduction of aquatic organisms, BaP was recently shown to affect fish bone formation and skeletal development through mechanisms that remain poorly understood. In this work, zebrafish bonerelated in vivo assays were used to evaluate the osteotoxic effects of BaP during bone development and regeneration. Acute exposure of zebrafish larvae to BaP from 3 to 6 days post-fertilization (dpf) induced a dosedependent reduction of the opercular bone size and a depletion of osteocalcin-positive cells, indicating an effect on osteoblast maturation. Chronic exposure of zebrafish larvae to BaP from 3 to 30 dpf affected the development of the axial skeleton and increased the incidence and severity of skeletal deformities. In young adults, BaP affected the mineralization of newly formed fin rays and scales, and impaired fin ray patterning and scale shape, through mechanisms that involve an imbalanced bone remodeling. Gene expression analyses indicated that BaP induced the activation of xenobiotic and metabolic pathways, while negatively impacting extracellular matrix formation and organization. Interestingly, BaP exposure positively regulated inflammation markers in larvae and increased the recruitment of neutrophils. A direct interaction between neutrophils and bone extracellular matrix or bone forming cells was observed in vivo, suggesting a role for neutrophils in the mechanisms underlying BaP osteotoxicity. Our work provides novel data on the cellular and molecular players involved in BaP osteotoxicity and brings new insights into a possible role for neutrophils in inflammatory bone reduction.
- Warming threatens to propel the expansion of the exotic seagrass Halophila stipulaceaPublication . Wesselmann, Marlene; Chefaoui, Rosa M.; Marbà, Núria; Serrao, Ester; Duarte, Carlos M.The spread of exotic species to new areas can be magnified when favored by future climatic conditions. Forecasting future ranges using species distribution models (SDMs) could be improved by considering physiological thresholds, because models solely based on occurrence data cannot account for plasticity due to acclimation of individuals to local conditions over their life-time or to adaptation due to selection within local populations. This is particularly relevant for the exotic seagrass Halophila stipulacea, which colonized the Mediterranean Sea a century ago and shifted its thermal niche, coping with a colder regime. Here, we used two hybrid models combining correlative SDMs with the thermal limits for growth of native and exotic H. stipulacea populations to predict the distribution of the species in its native (Indian Ocean and Red Sea) and exotic ranges (Mediterranean Sea and Caribbean Sea) under two scenarios forecasting limited (RCP 2.6) and severe (RCP 8.5) future climate changes by 2050 and 2100. Then, we assessed the differences between hybrid models based on native Red Sea thermal limits (niche conservatism: 17–36◦C) and on exotic Mediterranean thermal limits (local adaptation: 14–36◦C). At the Mediterranean exotic range, the local adaptation hybrid model accurately agreed with the present distribution of the species while the niche conservatism-based hybrid model failed to predict 87% of the current occurrences of the species. By contrast, both hybrid models predicted similar species distributions for the native range and exotic Caribbean range at present and projected that H. stipulacea will maintain its current worldwide under all future greenhouse gas emission scenarios. The hybrid model based on Mediterranean thermal limits projected the expansion of H. stipulacea through the western Mediterranean basin (except the gulf of Leon) under the most severe scenario (RCP 8.5) by 2100, increasing its distribution by 50% in the Mediterranean. The future expansion of H. stipulacea is related to its capacity to cope with warm waters and it may become a relevant species in the future, particularly under the projected decline of native Mediterranean seagrasses, resulting in important shifts in seagrass communities and overall ecosystem functions.