Percorrer por data de Publicação, começado por "2025-07-02"
A mostrar 1 - 3 de 3
Resultados por página
Opções de ordenação
- Improving the heterotrophic media of three chlorella vulgaris mutants toward optimal color, biomass and protein productivityPublication . Trovão dos Santos, Mafalda; Cunha, Miguel; Santo, Gonçalo Espírito; Pedroso, Humberto; Reis, Ana; Barros, Ana; Correia, Nádia; Schüler, Lisa; Costa, Monya; Ferreira, Sara; Cardoso, Helena; Ventura, Márcia; Varela, João; Silva, Joana; Freitas, Filomena; Pereira, HugoThe high production costs and unappealing sensory properties still limit the widespread commercialization of microalgae feedstocks. Therefore, this work focused on fine-tuning the heterotrophic medium composition to cultivate novel green, yellow, and white Chlorella vulgaris mutant strains. Screening assays were carried out to select the most significant factors, and different nutrient concentrations were optimized by modelling biomass and protein productivity, specific growth rate, and color, via response surface methodology. The biomass and protein productivities achieved by these strains were improved by up to 70% and 94%, respectively. Additionally, biomass color was correlated with medium composition for the first time, allowing the improvement of the yellow and white mutant colorations by 20%. Overall, the findings of this study are vital to overcoming the challenges of the biobased industry, allowing the enhancement of the cost-effectiveness, attractiveness, and nutritional profiles of microalgae-based products in different markets and applications.
- Determining the diversity and relative abundance of coral taxa in wild spawning slicks for effective restorationPublication . Marquardt, Bailey; Elder, Holland; Yeoh, Yun Kit; Heyward, Andrew; Randall, Carly J.; Harrison, Peter L.; Logan, Murray; Howells, EmilyCoral reefs are increasingly threatened by climate change-induced stressors, including marine heatwaves, which can lead to coral mortality, reduced reproductive output, and compromised natural recovery. Successful coral reef recovery requires the settlement of coral larvae and recruitment in degraded areas, replenishing coral communities and promoting resilience. Some restoration strategies involve utilizing natural spawning slicks, composed of coral gametes and embryos, to produce larvae to reseed reefs. However, verifying the taxonomic composition of these slicks is challenging. Here, we tested the performance of two coral ITS primer sets, CoralITS2 and CoralITS2_acro, on mock communities to evaluate their ability to capture genera composition and relative abundances. Both primer sets demonstrated high accuracy (>97%) in detecting and quantifying coral taxa. Subsequently, these primers were applied to wild-collected spawning slicks from the Great Barrier Reef, revealing variation in scleractinian (reef-building) coral community composition among slicks. For the CoralITS2_acro assay, Acropora was consistently the most abundant resolved genus detected across wild slick sample sites, with the exception of samples from the Whitsundays region, where Platygyra was dominant. The CoralITS2 assay successfully differentiated reef-building (Scleractinian) corals from other co-occurring spawning taxa, such as soft corals, anemones, and sponges, and revealed that these other co-spawners dominated slicks at two sites. Our findings underscore the potential of eDNA-based monitoring as a scalable tool to confirm the presence and relative abundance of diverse coral assemblages in natural slicks, informing restoration efforts. By enabling the characterization and comparison of slick composition across large spatial and temporal scales, eDNA metabarcoding can support restoration practices that align with the ecological requirements of reef ecosystems, safeguarding biodiversity and promoting resilience against future disturbances.
- On a planetary forcing of global seismicityPublication . Dumont, Stéphanie; d’Ars, Jean de Bremond; Boulé, Jean-Baptiste; Courtillot, Vincent; Gèze, Marc; Gibert, Dominique; Kossobokov, Vladimir; Mouël, Jean-Louis Le; Lopes, Fernando; Neves, Maria C.; Silveira, Graça; Petrosino, Simona; Zuddas, PierpaoloWe have explored the temporal variability of the seismicity at global scale over the last 124 years, as well as its potential drivers. To achieve this, we constructed and analyzed an averaged global seismicity curve for earthquakes of magnitude equal or greater than 6.0 since 1900. Using Singular Spectrum Analysis, we decomposed this curve and compared the extracted pseudo-cycles with two global geophysical parameters associated with Earth’s tides: length-of-day variations and sea-level changes. Our results reveal that these three geophysical signal curves can be reconstructed up to ∼90% by the sum of up to seven periodic components ranging from 1 to ∼60 years, largely aligned with planetary ephemerides. We discuss these results in the framework of Laplace’s theory, with a particular focus on the phase relationships between seismicity, length-of-day variations, and sea-level changes to further elucidate the underlying physical mechanisms. Finally, integrating observations from seismogenic regions, we propose a possible trigger mechanism based on solid Earth–hydrosphere interactions, emphasizing the key role of water-rock interactions in modulating earthquake occurrence.