1,507 research outputs found
Promoting the connection between fishermen and consumers, regarding the sustainability of the exploitation of Meagre (Argyrosomus regius): nutritional quality and food safety in Tagus Estuary
Meagre (Argyrosomus regius (Asso, 1801) belongs to the Sciaenidae family, with a distribution along the Northeast and Midwest Atlantic from the coast of Sweden to the Gulf of Guinea and in the Mediterranean Sea and Black Sea. In Portugal, meagre is target of commercial and recreational fishing being Tagus estuary and adjacent coastal zone responsible for more of 70% of the catches at national level. In recent years, Costa da Caparica, Trafaria and Sesimbra auctions, transacted an annual record of a volume of catches close to 132 tons. The fact that meagre can reach appreciable dimensions, and that its highly appreciated gastronomically, means that it is sold at prices between 7-12 €/kg, making it the economically attractive for small commercial fishermen. The One Health concept is a triad of human, animal, and environmental health. The fact that meagre, captured in the Tagus, is distributed by several national auctions in which sanitary control does not guarantee the screening of priority contaminants, associated with the unequivocal contamination of Tagus estuarine waters and/or trophic chains, presents us a relevant problem, concerning to the transfer of pollutants through food chains, and the urgency of increasingly reliable determinations of these compounds in this species. The nutritional profile of meagre was analyzed and complemented with analysis of tissue susceptibility to toxicity by persistent organic pollutants (POPs) using state-of-the-art technology and an integrative approach
The relationship between fatty acids and fish: lesser-known aspects and the need for increasingly efficient analytical techniques
When we associate the word fatty acids with fish, most people identify fish as sources of fatty acids from the omega families. This relationship is always present in the valuation of nutritional quality of fish. However, fatty acids have many other crucial functions in fish. The oldest studies related to fatty acids focused essentially on their role as sources metabolic energy in the form of ATP through β-oxidation. Many studies referred the fatty acid role for migrations, energy production during growth and egg formation, among others. Soon fatty acids quickly began to be studied from the point of view of source of essential nutrients for several physiological processes and integral components of biological membranes. The high content of highly polyunsaturated fatty acids found in fish is related to the fact that they are poikilothermic. In the presence of various temperature scenarios, fish can effectively exploit a wide chemical diversity of membrane fatty acid profiles, to defend their physical properties, such as fluidity. In the last decades, fatty acids have been used as either biomarkers because they are limited to certain taxa and they can be transferred conservatively from primary producers to higher trophic level or stock identifiers because the fatty acid composition of phospholipids in some body tissues have a stable genetics basis.
In the last decades multiple techniques have been used for fatty acid analysis. As a rule, before the instrumental analysis, the sample requires 2 previous steps. These comprise extraction of lipids from the matrix and derivatization. The combination of these two stages generates multiple methodologies that are not always standardized. Soon, the analysis of fatty acids tends to reduce and standardize these previous analyses while the instrumental analysis should solve problems related to similar mass spectra of the isomers and coelution between fatty acidsFundação para a Ciência e Tecnologia (FCT) for a PhD scholarship UI/BD/153381/2022.This work was funding by National Funds through FCT - Foundation for Science and Technology under the Project PTDC/BIA-BMA/030517/2017 and the Portuguese Science Foundation through the strategy plan for MED (Mediterranean Institute for Agriculture, Environment and Development), via project UIDB/05183/2020, for MARE (Marine and Environmental Sciences Centre), via project UIDB/04292/2020, UID/50006/2020, and under the project LA/P/0069/2020 granted to the Associate Laboratory ARNET; and for LAQV-REQUIMTE, via project UIDB/50006/2020 and UIDP/50006/202
Nernst Effect and Anomalous Transport in Cuprates: A Preformed-Pair Alternative to the Vortex Scenario
We address those puzzling experiments in underdoped high
superconductors which have been associated with normal state "vortices" and
show these data can be understood as deriving from preformed pairs with onset
temperature . For uncorrelated bosons in small magnetic fields, and
arbitrary , we present the exact contribution to \textit{all}
transport coefficients. In the overdoped regime our results reduce to those of
standard fluctuation theories (). Semi-quantitative agreement
with Nernst, ac conductivity and diamagnetic measurements is quite reasonable.Comment: 9 pages, 4 figures; Title, abstract and contents modified, new
references added, figures changed, one more figure added; to be published on
PR
Movements of hatchery-reared dusky groupers released in a Northeast Atlantic Coastal Marine Protected Area.
No-take areas are key instruments to promote the effectiveness of Marine Protected Areas (MPAs), particularly concerning the protection of endangered species such as the dusky grouper (Epinephelus marginatus). However, despite the establishment of no-take areas and the prohibition of catching this species in a southwestern Portuguese MPA (SACVMP—‘Sudoeste Alentejano’ and ‘Costa Vicentina’ Marine Park) since 2011, there is still no evidence of population recovery. By using acoustic biotelemetry, this work aimed to evaluate the feasibility of restocking hatchery-reared adult dusky groupers in two no-take areas within the SACVMP. In 2019 and 2021, thirty groupers were tagged with acoustic transmitters and the site attachment and movements of the groupers were assessed in the releasing sites (no-take areas). None of the tagged fish settled down in either of the areas, leaving the no-take areas mainly at dusk and night. Some individuals displayed extended movements of more than a hundred kilometers along the Portuguese coast which was rarely reported for this species. At least in some coastal stretches, those movements were performed close to the shore, which may evidence the importance of coastal MPAs to protect and promote the connectivity of species more associated with rocky reef habitats. Following studies should focus on the conditions that promote site attachment and fidelity by hatchery-reared dusky groupers so that future large-scale restocking programs can be successful in MPAs with appropriate habitats
Comportamento Per Se De HÃbridos De Capim-elefante Para Fins Energéticos
The aim of this study was to evaluate the Per se performance of elephant grass hybrids obtained by partial diallel crossing and also their parents for energy purposes through agronomic traits during rainy and dry seasons. The experiment was conducted at Pesagro experimental station, Campos dos Goytacazes, RJ, Brazil, in randomized blocks, with three repetitions. The crosses were made between contrasting parents in a partial diallel scheme with 5 female parents × 5 male parents. The treatments consisted of ten parents, twenty-five hybrid combinations and the control. Three cuts were realized for evaluations (April and October 2013 and April 2014). The characteristics evaluated were: plant height (ALT), in m; stem diameter (SD), in cm; leaf blade width (LB), in cm; number of tillers per linear meter (NP); dry matter percentage (%DM) and dry matter production (DMP), in t.ha-1. Variance analysis were performed and the means were grouped according to Scott-Knott test (P>0.05). It was oberved that the hybrid H4 (Cuban Pinda x Taiwan A-144), H7 (Cameroon - Piracicaba × Três Rios), H8 (Cameroon - Piracicaba × Mercker 86-Mexico), H10 (Cameroon - Piracicaba × Roxo), H13 (P241-86-Piracicaba × Mercker 86-Mexico), H17 (IAC Campinas × Três Rios) and H18 (IAC-86-Campinas × Mercker 86-Mexico) presented high biomass production.71738
Evidence Linking PPARG Genetic Variants with Periodontitis and Type 2 Diabetes Mellitus in a Brazilian Population
The peroxisome proliferator-activated receptor gamma (PPARG) gene encodes a transcription factor involved in the regulation of complex metabolic and inflammatory diseases. We investigated whether single nucleotide polymorphisms (SNPs) and haplotypes of the PPARG gene could contribute with susceptibility to develop periodontitis alone or together with type 2 diabetes mellitus (T2DM). Moreover, we evaluated the gene–phenotype association by assessing the subjects’ biochemical and periodontal parameters, and the expression of PPARG and other immune response–related genes. We examined 345 subjects with a healthy periodontium and without T2DM, 349 subjects with moderate or severe periodontitis but without T2DM, and 202 subjects with moderate or severe periodontitis and T2DM. PPARG SNPs rs12495364, rs1801282, rs1373640, and rs1151999 were investigated. Multiple logistic regressions adjusted for age, sex, and smoking status showed that individuals carrying rs1151999-GG had a 64% lower chance of developing periodontitis together with T2DM. The CCGT haplotype increased the risk of developing periodontitis together with T2DM. The rs1151999-GG and rs12495364-TC were associated with reduced risk of obesity, periodontitis, elevated triglycerides, and elevated glycated hemoglobin, but there was no association with gene expression. Polymorphisms of the PPARG gene were associated with developing periodontitis together with T2DM, and with obesity, lipid, glycemic, and periodontal characteristics
Properties and DEFC tests of Nafion Functionalized titanate nanotubes composite membranes prepared by melt extrusion
Nafion based composites are promising materials to improve the performance of direct ethanol fuel cells. In this work, composite membranes of Nafion and titanate nanotubes functionalized with sulfonic acid groups were prepared by melt extrusion and tested in a direct ethanol fuel cell. Far and mid infrared spectroscopies evidenced the formation of ionic bridges between the sulfonic acid groups of both functionalized nanoparticles and the ionomer. Small angle X ray scattering measurements revealed that the melt extrusion method leads to an uniform distribution of the inorganic phase in the ionomer matrix. Such structural analysis indicated that the improved the proton conduction properties of the composites, even with the addition of a high concentration of functionalized nanoparticles, are an outcome of the synergistic ionic network due to the hydrid organic inorganic proton conducting phases. However, an improvement of the fuel cell performance is observed for 2.5 wt of functionalized titanate nanotubes, which is a result of the lower ethanol crossover and the plasticizing effect of the aliphatic segments of the organic moieties grafted at the surface of the titanate nanoparticle
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