Seasonal and spatial variability of Phytoplankton primary production in a shallow temperate Coastal Lagoon (Ria Formosa, Portugal)

Coastal lagoons are among the most productive ecosystems in the world, and they provide a wide range of ecosystem services and resources. In the Ria Formosa (southern Portugal), phytoplankton production has rarely been addressed. The main goal of this study is thus to evaluate the variability of phytoplankton production and photosynthetic characteristics over the seasonal cycle and in different locations (landward, urban, intermediate, and seaward boundaries) of the Ria Formosa coastal lagoon, subjected to distinct natural and anthropogenic stressors. Primary production was evaluated using the 14C incorporation technique, and photosynthetic parameters were estimated by fitting photosynthesis-irradiance curves. Primary production showed significant seasonal variations, with higher values in the summer associated with lower euphotic depths, higher water temperatures, and higher nutrient concentrations. No spatial differences were found for primary production or photosynthetic parameters. Primary production values were lower than previous estimates, which reflects an improvement in water quality in the Ria Formosa, but values are higher than primary production estimates for other temperate coastal ecosystems, which reflects the highly productive nature of this coastal lagoon.info:eu-repo/semantics/publishedVersio

Translocating the blood-brain barrier using electrostatics

Copyright © 2012 Ribeiro,Domingues, Freire,Santos and Castanho. This is an open-access article distributed under the terms of the Creative Commons Attribution License, which permits use, distribution and reproduction in other forums, provided the original authors and source are credited and subject to any copyright notices concerning any third-party graphics etc.Mammalian cell membranes regulate homeostasis, protein activity, and cell signaling. The charge at the membrane surface has been correlated with these key events. Although mammalian cells are known to be slightly anionic, quantitative information on the membrane charge and the importance of electrostatic interactions in pharmacokinetics and pharmacodynamics remain elusive. Recently, we reported for the first time that brain endothelial cells (EC) are more negatively charged than human umbilical cord cells, using zeta-potential measurements by dynamic light scattering. Here, we hypothesize that anionicity is a key feature of the blood-brain barrier (BBB) and contributes to select which compounds cross into the brain. For the sake of comparison, we also studied the membrane surface charge of blood components—red blood cells (RBC), platelets, and peripheral blood mononuclear cells (PBMC).To further quantitatively correlate the negative zeta-potential values with membrane charge density, model membranes with different percentages of anionic lipids were also evaluated. From all the cells tested, brain cell membranes are the most anionic and those having their lipids mostly exposed, which explains why lipophilic cationic compounds are more prone to cross the blood-brain barrier.Fundação para a Ciência e Tecnologia — Ministério da Educação e Ciência (FCT-MEC, Portugal) is acknowledged for funding (including fellowships SFRH/BD/42158/2007 to Marta M.B. Ribeiro, SFRH/BD/41750/2007 to Marco M. Domingues and SFRH/BD/70423/2010 to João M. Freire) and project PTDC/QUI-BIQ/119509/2010. Marie Curie Industry-Academia Partnerships and Pathways (European Commission) is also acknowledged for funding (FP7-PEOPLE-2007-3-1-IAPP, Project 230654)

A strategy to gradual implementation of data interoperability

Data interoperability is a major concern on e-government, both from the point of view of service offering and from the point of view of public administration efficiency. This paper purposes an incremental, pragmatic approach to data interoperability. It is argued that integration with minor required initial efforts from institutions is feasible, may provide useful solutions and is a solid ground basis for subsequent evolution. This paper presents general guidelines and model solutions to support this approach. Also, presents a demo implementation that proves feasibility of the purposed models and delivers useful solutions on a specific business e-government scenario. Although still limited in range and demonstrated on a quite specific business environment, it is expected that the analysis and the proposed strategies, solutions and models be of interest on a larger spectrum of data interoperability problems.info:eu-repo/semantics/acceptedVersio

Disordered eating behaviours and correlates in yoga practitioners: a systematic review

PurposeYoga has been increasingly used as a complementary therapy for eating disorders. However, it is still not clear whether yoga is effective in the prevention and treatment of eating disorders, as some studies suggest that yoga practitioners show elevated levels of disordered eating behaviours. The goal of this systematic review is, thus, to analyse the occurrence of disordered eating behaviours and correlates in yoga practitioners.MethodPRISMA guidelines for systematic reviews were used. Search was conducted in several databases and specific journals.ResultsTwelve articles, all cross-sectional, were identified, following PRISMA guidelines. Results across studies were inconsistent. Yoga practice was usually associated with healthier eating behaviours, lower disordered eating symptoms, and higher positive body image and body satisfaction, suggesting that yoga practitioners may be at a lower risk of developing eating disorders. However, other studies suggested that a high dosage of yoga practice may be associated with a higher prevalence of disordered eating behaviours.ConclusionsAs yoga is increasingly used as therapy for eating disorders, understanding the relationship between yoga dosage and disordered eating behaviours is critical to guide treatment recommendations and establish yoga as a valuable complementary therapy.Level of evidenceLevel I, systematic review.Portuguese Foundation for Science and Technology (FCT)Portuguese Foundation for Science and Technology [DL57/2016]info:eu-repo/semantics/publishedVersio

A brief journey along time in the Guadiana estuary

The physical characteristics of the Guadiana estuary and the richness of its adjacent territories were essential in defining the historical and cultural context of the entire region. The extended navigability of the estuary was fundamental to establish trade routes with the Mediterranean civilizations, namely with the Phoenicians, Greeks, and Carthaginians. These civilizations created several commercial harbors along the Guadiana, namely in Mértola, Alcoutim, Castro Marim and Ayamonte. In these locations the human presence dates back as far as the Neolithic (12,000 to 4,000 BCE) and the Chalcolithic periods (4,000 to 3,100 BCE). Later, the Romans (II BCE to V CE), the Alans (V to VI CE.), the Visigoths (VI to VIII CE), and the Arabs (VIII to XIII CE) successively settled in this Iberian region, until the borders of the continental Portuguese territory were set in the 13th century. The predominant North-South direction of the estuary is intrinsically linked with the definition of the Portuguese and Spanish territories, as it serves as a natural border in its last 50 km. Ore extraction and cereal production in the surrounding areas of the estuary turned Mértola into the most important trading center, up to the Portuguese conquest in 1238 (Fig. 6.1). Copper, iron, and manganese were the main ore resources, but silver and gold were exploited as well. With the Portuguese conquests, the economic importance of the Guadiana estuary decreased sharply. In the 15th and 16th centuries, cereals were shipped to the Portuguese forts of northern Africa, but it was only in the late 19th century that all the regions around the estuary had a new economic burst.info:eu-repo/semantics/publishedVersio

SAMplus: adaptive optics at optical wavelengths for SOAR

Adaptive Optics (AO) is an innovative technique that substantially improves the optical performance of ground-based telescopes. The SOAR Adaptive Module (SAM) is a laser-assisted AO instrument, designed to compensate ground-layer atmospheric turbulence in near-IR and visible wavelengths over a large Field of View. Here we detail our proposal to upgrade SAM, dubbed SAMplus, that is focused on enhancing its performance in visible wavelengths and increasing the instrument reliability. As an illustration, for a seeing of 0.62 arcsec at 500 nm and a typical turbulence profile, current SAM improves the PSF FWHM to 0.40 arcsec, and with the upgrade we expect to deliver images with a FWHM of $\approx0.34$ arcsec -- up to 0.23 arcsec FWHM PSF under good seeing conditions. Such capabilities will be fully integrated with the latest SAM instruments, putting SOAR in an unique position as observatory facility.Comment: To appear in Proc. SPIE 10703 (Ground-based and Airborne Instrumentation for Astronomy VII; SPIEastro18

ANCA-positive vasculitis: Clinical implications of ANCA types and titers

INTRODUCTION: Anti-neutrophil cytoplasmic antibody (ANCA)-associated vasculitis is an autoimmune disease that can affect multiple organs, the kidney being one of the most affected. Apart from the diagnostics value of ANCA, they have also been advocated as biomarkers of the disease activity. Recently, the genetic changes found in polyangiitis associated with serine-protease proteinase 3 (PR3)-ANCA or myeloperoxidase (MPO)-ANCA raised the possibility of immune-pathogenic and therapeutic differences. OBJECTIVE: To identify differences in the number of relapses, inflammatory markers, outcomes and renal histology related to the types of ANCA. To analyze the implications of ANCA titers in prognosis. METHOD: A retrospective observational study in a Portuguese tertiary hospital. RESULTS: There were no differences in the progression of renal function, histological pattern and initial treatment with regard to ANCA subtypes. As for the evaluated parameters, there were no significant differences according to the types of ANCA, except for mean CRP values within the normal range, which was 6.3±1.3 mg/L for MPO-ANCA and 12.4±10.14 mg/L for PR3-ANCA (p=0.04). We found that 66.7% of the MPO-ANCA-positive showed no relapses versus 40% in the case of PR3-ANCA-positive. There was no correlation between the ANCA titers at presentation, during remission, and in the last evaluation, and the number of relapses. CONCLUSION: PR3-ANCA patients have a mean CRP value within the normal range significantly higher than that of MPO-ANCA patients (p=0.04), which seems to reveal greater inflammatory activity in the first.info:eu-repo/semantics/publishedVersio

Unusual red tide of the dinoflagellate Lingulodinium polyedra during an upwelling event off the Algarve coast (SW Iberia)

Low biomass, but highly toxic algal blooms are frequent in the Ria Formosa coastal lagoon and adjacent coastal zone (southern Portugal), usually associated with specific oceanographic and nutrient conditions. In June 2019, a massive bloom of the dinoflagellate Lingulodinium polyedra developed along the coast, causing water discolouration, and the closure of beaches and of bivalve harvesting, with significant socioeconomic consequences. This study aims to evaluate the relationships between phytoplankton composition and environmental conditions before, during, and after the L. polyedra bloom. Water samples were collected in the Ria Formosa coastal lagoon throughout June and July 2019 for determination of nutrient and chlorophyll-a concentration using spectrophotometric methods. Phytoplankton composition and abundance were evaluated using inverted microscopy. Upwelling intensity was estimated considering a wind-based index, the cross-shore Ekman transport. Results show strong relationships between phytoplankton community composition and nutrients, particularly a positive relationship between centric diatoms and nitrogen, and a negative relationship between several dinoflagellate genera, and phosphorus and silicon. L. polyedra was not significantly associated with any nutrient variable, most likely due to its mixotrophic capabilities. A clear phytoplankton succession, typical of eastern boundary upwelling locations, was observed throughout the different bloom phases, from dominance of type II dinoflagellates (Heterocapsa, Prorocentrum) in the pre-bloom period, to dominance of L. polyedra (type V) during the bloom, and finally dominance of centric diatoms in the post-bloom period. However, the L. polyedra bloom was not associated with upwelling relaxation, but rather with an active upwelling event. (c) 2023 The Author(s). Published by Elsevier B.V. This is an open access article under the CC BY-NC-ND license (http://creativecommons.org/licenses/by-nc-nd/4.0/).LA/P/0069/2020info:eu-repo/semantics/publishedVersio

Co-limitation of phytoplankton by N and P in a shallow coastal lagoon (Ria Formosa): implications for eutrophication evaluation

The Ria Formosa coastal lagoon is a highly productive shallow ecosystem in southern Portugal, subjected to nutrient inputs from anthropogenic and natural sources. Nutrients are major abiotic drivers of phytoplankton in this system, but their effects on phytoplankton assemblages and the occurrence of nutrient limitation are still poorly understood. The main goal of this study was, thus, to evaluate the occurrence, type, and effects of nutrient limitation on phytoplankton community and specific functional groups in the Ria Formosa coastal lagoon. We conducted nutrient enrichment experiments with factorial additions of nitrogen (N) and phosphorus (P) using natural phytoplankton assemblages from distinct locations in the Ria Formosa, throughout a yearly cycle. Phytoplankton composition and abundance were evaluated using inverted and epifluorescence microscopies, and spectrophotometric methods were used for biomass. Limitation was defined as higher phytoplankton growth following enrichment with a particular nutrient in relation to the non-enriched control. The most common type of phytoplankton limitation was simultaneous co-limitation by N and P; diatoms, as r-strategists, were the most frequently limited group. Single N and P limitation, and serial P limitation were also observed, as well as negative responses to nutrient enrichment. Group-specific responses to nutrient enrichment were not reflected in the relative abundance of phytoplankton groups within the whole assemblage, due to the numerical dominance of pico-sized groups (cyanobacteria and eukaryotic picophytoplankton). Ambient nutrient ratios and concentrations did not predict phytoplankton nutrient limitation, given the different nutrient utilisation traits among phytoplankton functional groups. Therefore, nutrient ratios should not be used as indicators of nutrient limitation in eutrophication assessment.LA/P/0069/2020info:eu-repo/semantics/publishedVersio

River damming leads to decreased phytoplankton biomass and disappearance of cyanobacteria blooms

The large Alqueva dam was built in the early 2000s in the Guadiana River (southern Portugal) and has highly controlled the freshwater flowing into the Guadiana estuary, leading to significant changes in the natural hydrological regime. To evaluate the impacts of water restriction and flow regularization on estuarine phytoplankton and their environmental variables, sampling campaigns were conducted in the Guadiana estuary throughout a 14-year period, covering different phases related to the Alqueva dam construction. Significant alterations in phytoplankton and their environmental drivers were observed. In the post-filling period, river flow became more constant throughout the year and its natural seasonal variability, with maxima in the winter and minima in the summer, was greatly reduced, leading to higher river flows in the summer and lower in the winter, in relation to the pre-filling phase. Nutrient and light availability and, hence, phytoplankton dynamics, were greatly affected. Phytoplankton abundance and biomass decreased in the post-filling phase related to a decrease in diatoms and cyanobacteria. Since cyanobacteria blooms in the Guadiana are frequently dominated by toxic species, this constitutes an improvement in water quality. However, the overall decrease in phytoplankton biomass and, specifically, the decline in diatom biomass, will have major consequences for the higher trophic levels that depend on planktonic food