Browsing by Author "Silva, R."
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- Assessing the conservation status of Mediterranean temporary ponds using biodiversity: a new tool for practitionersPublication . Marques, J. T.; Belo, A. F.; Cristo, Margarida de Lurdes de Jesus Bastos; Fernandes, M.; Galioto, D.; Machado, M.; Mira, A.; Sa-Sousa, P.; Silva, R.; Sousa, L. G.; Pinto-Cruz, C.The assessment of the habitat condition is the first step of conservation actions and several tools are available to assess wetlands. However, only a few tools are adapted to the priority habitat Mediterranean temporary ponds. Thus, our objectives were (i) to identify biological indicators associated with the different conservation status of Mediterranean temporary ponds and (ii) to create an efficient evaluation tool for non-experts using indicators of conservation status. A total of 87 ponds were sampled in southwest Portugal to assess the presence of plants, large branchiopods, amphibians, threatened voles and bats. Ponds with favourable conservation status showed higher species richness of plants, large branchiopods and amphibians. We identified eighteen indicators for favourable ponds: 15 plants, one large branchiopod and two amphibian taxa. We propose a new tool to assess the conservation status of Mediterranean temporary ponds based on the presence of these indicators. This tool is an alternative to other common, but time-consuming, methods and can be readily used by trained practitioners. The replication and adaptation of this tool to other regions and habitats enables the collection of comparable data and the geographical scaling-up of the assessments.
- Cultura sem solo com reutilização dos efluentes, em estufa com controlo ambiental melhoradoPublication . Reis, Mário; Rosa, Armindo; Silva, R.; Caço, JoãoO projecto em execução no Centro de Experimentação Hortofrutícola do Patacão com a participação da Universidade do Algarve, da Direcção Regional de Agricultura do Algarve e do Centro de Hidroponia e Utilidades Hortoflorícolas Lda, tem por objectivos o melhoramento das condições tecnológicas da produção hortícola e a promoção da divulgação das novas tecnologias de horticultura intensiva, mais produtivas e menos poluentes, ao mesmo tempo que se pretende elaborar um estudo económico detalhado que apoie a tomada de decisões, tanto pelo agricultor como pelos órgãos administrativos.
- Functional metagenomics reveals differential chitin degradation and utilization features across free-living and host-associated marine microbiomesPublication . Raimundo, I.; Silva, R.; Meunier, L.; Valente, S. M.; Lago-Lestón, A.; Keller-Costa, T.; Costa, RodrigoBackground Chitin ranks as the most abundant polysaccharide in the oceans yet knowledge of shifts in structure and diversity of chitin-degrading communities across marine niches is scarce. Here, we integrate cultivation-dependent and -independent approaches to shed light on the chitin processing potential within the microbiomes of marine sponges, octocorals, sediments, and seawater. Results We found that cultivatable host-associated bacteria in the genera Aquimarina, Enterovibrio, Microbulbifer, Pseudoalteromonas, Shewanella, and Vibrio were able to degrade colloidal chitin in vitro. Congruent with enzymatic activity bioassays, genome-wide inspection of cultivated symbionts revealed that Vibrio and Aquimarina species, particularly, possess several endo- and exo-chitinase-encoding genes underlying their ability to cleave the large chitin polymer into oligomers and dimers. Conversely, Alphaproteobacteria species were found to specialize in the utilization of the chitin monomer N-acetylglucosamine more often. Phylogenetic assessments uncovered a high degree of within-genome diversification of multiple, full-length endo-chitinase genes for Aquimarina and Vibrio strains, suggestive of a versatile chitin catabolism aptitude. We then analyzed the abundance distributions of chitin metabolism-related genes across 30 Illumina-sequenced microbial metagenomes and found that the endosymbiotic consortium of Spongia officinalis is enriched in polysaccharide deacetylases, suggesting the ability of the marine sponge microbiome to convert chitin into its deacetylated—and biotechnologically versatile—form chitosan. Instead, the abundance of endo-chitinase and chitin-binding protein-encoding genes in healthy octocorals leveled up with those from the surrounding environment but was found to be depleted in necrotic octocoral tissue. Using cultivation-independent, taxonomic assignments of endo-chitinase encoding genes, we unveiled previously unsuspected richness and divergent structures of chitinolytic communities across host-associated and free-living biotopes, revealing putative roles for uncultivated Gammaproteobacteria and Chloroflexi symbionts in chitin processing within sessile marine invertebrates. Conclusions Our findings suggest that differential chitin degradation pathways, utilization, and turnover dictate the processing of chitin across marine micro-niches and support the hypothesis that inter-species cross-feeding could facilitate the co-existence of chitin utilizers within marine invertebrate microbiomes. We further identified chitin metabolism functions which may serve as indicators of microbiome integrity/dysbiosis in corals and reveal putative novel chitinolytic enzymes in the genus Aquimarina that may find applications in the blue biotechnology sector. Video abstract
- In vitro antioxidant activity, phenolic compounds and protective effect against DNA damage provided by leaves, stems and flowers of Portulaca oleracea (Purslane)Publication . Silva, R.; Carvalho, Isabel Saraiva deThis study analyzed the antioxidant properties of Portulaca oleracea L., known as purslane. The samples (leaves, flowers and stems) were collected at two different locations in Portugal: Tavira (L1) and Vendas Novas (L2). Assays for total antioxidant activity, total phenolic content and ferric-reducing antioxidant power were conducted and, for both locations, significantly higher values (P<0,05) were observed for stems (508.8 and 982.3 mg AAE/100 g DW, 1008.6 and 2285.5 mg GAE/100 g DW, 121.0. and 166.3 mg TE/100 g DW, respectively for each location), than in leaves or flowers. In the DPPH assay, the three-plant parts from L2 reached the 50% inhibition rate in lower concentrations than plants from L1. On the other hand, higher concentrations of total monomeric anthocyanins were found in samples from L1 (95.5, 88.8 and 86.0 mg/L) than in samples from L2 (81.7, 70.5 and 59.8 mg/L). The same was true for phenolic acids, estimated by liquid-chromatography, where methanol extracts were used. Phenolic extracts from all three-plant parts from both locations showed protective effects on DNA against hydroxyl radicals. This work suggests the possibility of benefit to human health from its consumption, related to the high antioxidant activity of purslane, even the stems, usually discarded in daily consumption.
- New generation oral appliances for treatment of obstructive sleep apneaPublication . Silva, R.; Pires, L.; Belchior, I.; Moniri, ArminOral appliances (OA) have become one of the most important treatments for obstructive sleep apnea (OSA). Efficacy and compliance have been issues raised with this treatment modality. The new generation OAs, using precision technology, are generally smaller devices occupying less space in the mouth. They create less protrusion of the mandible compared to the classical devices. Previous studies on these devices report superior efficacy and compliance. In this study we evaluate the efficiency and compliance of a new generation OA, the Prosomnus EVO, in patients with mild-moderate OSA.