196 research outputs found

    LEAD ACCUMULATION AND SUBCELULAR DISTRIBUTION IN THE SCALLOP AEQUIPECTEN OPERCULARIS

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    The scallop Aequipecten opercularis accumulates high concentrations of lead (Pb) in its tissues, what has led to the ban of its extraction in the Ría de Vigo (Galicia, Spain) for feeding purposes. The Ría de Vigo presents higher levels of Pb than other industrialized Galician Rías, mainly due to a ceramic factory that was operating in the inner part of the Ría from 1961 to 2001 (Álvarez-Iglesias et al., 2003). This study aims at testing the dynamics of bioaccumulation of Pb in this species, its tissue distribution and the subcellular partitioning Pb, with the aim of enhancing our understanding of the mechanisms that provoke the high Pb levels reached in its tissues. Scallops originating from a clean area were exposed in cages in two places in the Ría de Vigo (one harbour and a less impacted location) and 10 individuals were collected every month over a three months period. The bioaccumulation of Pb and other metals was studied including its distribution in several tissues: gills, digestive gland, kidney, muscle, gonad and rest. The results showed that scallops accumulated similar levels of Pb in both locations, and that about 76% of the Pb was found in the kidney. Subcellular partitioning of kidney samples additionally showed that around a 60-70% of Pb in the kidneys was included in metal rich granules, indicating that this is probably the reason of the high levels of Pb observed in this species, as occurs for other bivalves (Darriba and Sánchez-Marín, 2013). Concerning other metals analysed, it was observed that Zn was also mainly accumulated in the kidney, while Cd content was highest in the digestive gland. Cu and Ni were preferentially accumulated in the digestive gland or kidney, depending on the location, and As was mainly found in the muscle. Results will be discussed on the basis of metal pollution in both locations and according to detoxification strategies used by scallops

    Corporate sustainability, organizational resilience and corporate purpose: a triple concept for achieving long-term prosperity

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    Purpose: In this paper, we aim to narrow the gap caused by the lack of literature relating the three concepts of corporate sustainability, organizational resilience, and corporate purpose in the context of corporations. We want to present a framework that explains how these three concepts are related and effectively merged for long-term corporate survival. Design/methodology/approach: We present a systematic review. We first proposed initial search strategies to identify those documents that define each concept and to identify concepts with which each concept is associated. Subsequently, we designed a search strategy combining all three concepts and their associated concepts to gather and analyze all the possible studies that have tried to connect these concepts. We finally identify some gaps in the understanding of how these three concepts are related. Findings: We contend that corporate sustainability, organizational resilience, and corporate purpose merge to achieve long-term corporate survival. We explain that there exists a two-way relationship between these three variables. We also present gaps and future directions that should be addressed to foster an increase in knowledge about the relationships between corporate sustainability, organizational resilience, and corporate purpose. Originality: Nowadays, some authors do endeavor to explain how aspects such as corporate sustainability, organizational resilience, and corporate purpose are crucial in the dynamic environment facing corporations every day. Nevertheless, there needs to be more understanding of how these three concepts are related and effectively merged for long-term corporate survival. This paper contributes to the literature by closing this gap

    Effect of dissolved organic matter (DOM) of contrasting origins on Cu and Pb speciation and toxicity to Paracentrotus lividus larvae

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    4 tablas, 6 figurasWater samples of contrasting origin, including natural seawater, two sediment elutriates and sewage-influenced seawater, were collected and obtained to examine the effect of the dissolvedorganicmatter (DOM) present on metal bioavailability. The carbon content (DOC) and the optical properties (absorbance and fluorescence) of the coloured DOM fraction (CDOM) of these materials were determined. Cu and Pb complexation properties were measured by anodic stripping voltammetry (ASV) and the effect of DOM on Cu and Pb bioavailability was studied by means of the Paracentrotus lividus embryo-larval bioassay. Sediment elutriates and sewage-influenced water (1) were enriched 1.4–1.7 times in DOC; (2) absorbed and reemitted more light; and (3) presented higher Cu complexation capacities (LCu) than the natural seawater used for their preparation. LCu varied from 0.08 μM in natural seawater to 0.3 and 0.5 μM in sediment elutriates and sewage-influenced water, respectively. Differences in DOC, CDOM and Cu complexation capacities were reflected in Cu toxicity. DOM enriched samples presented a Cu EC50 of 0.64 μM, significantly higher than the Cu EC50 of natural and artificial seawater, which was 0.38 μM. The protecting effect of DOM on Cu toxicity greatly disappeared when the samples were irradiated with high intensity UV-light. Cu toxicity could be successfully predicted considering ASV-labile Cu concentrations in the samples. Pb complexation by DOM was only detected in the DOM-enriched samples and caused little effect on Pb EC50. This effect was contrary for both elutriates: one elutriate reduced Pb toxicity in comparison with the control artificial seawater, while the other increased it. UV irradiation of the samples caused a marked increase in Pb toxicity, which correlated with the remaining DOC concentration. DOM parameters were related to Cu speciation and toxicity: good correlations were found between DOC and Cu EC50, while LCu correlated better with the fluorescence of marine humic substances. The present results stress the importance of characterizing not only the amount but also the quality of seawater DOM to better predict ecological effects from total metal concentration dataP.S-M was granted with an FPU-fellowship from the Spanish Ministry of 15 Education and Science. J.S-E thanks the Basque Government for financial support (pre-doctoral grant). Research was partially funded by the project PGIDIT-05MA40201PR (Xunta de Galicia) and CTM2006-13880-C03-01/MAR (Spanish Ministry of Education and Science).Peer reviewe

    CONSEQUENCES OF SINGULAR ENVIRONMENTAL EVENTS ON THE CYCLE OF METALS IN COASTAL LAGOONS AND THEIR INFLUENCE ON THE INCORPORATION OF METALS BY PRIMARY PRODUCERS

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    Coastal areas are valuable and sensitive environments subjected to great anthropogenic pressure. Among these pressures, metal pollution is of priority concern as these pollutants can reach concentrations that exceed the levels established to protect sensitive organisms in the ecosystem. In coastal lagoons, shallow systems with a reduced exchange with the open sea, metal concentrations are one or two orders of magnitude higher than in open-waters. In addition, these systems are subjected to physicochemical variations that can alter the biogeochemical cycling of the metals. Singular environmental events such as strong winds cause metal resuspension, torrential rain events provoke the entrance of solutes and pollutants, and phytoplankton blooms dramatically increase the concentration of organic matter. These events provoke alterations in the concentration and speciation of metals in the water column. This will have a direct impact in the organisms living in the area, since metal toxicity and bioavailability depends on the chemical speciation. Dissolved organic matter (DOM) is the most important variable influencing metal speciation and bioavailability in seawater. However, the effects of DOM on metal bioavailability have not been yet unravelled and contrasting results have been reported, some showing that DOM protects against metal toxicity and others showing the opposite. The present study was designed to study how the biogeochemical cycling of trace metals in the water column of coastal lagoons is influenced by these singular environmental events and how this affects the incorporation of metals by the primary producers, in this case, microalgae, with particular focus on the effect of dissolved organic matter on metal biouptake. The proposed work combines field sampling and analytical work in the Mar Menor lagoon (SE Spain). This project will substantially contribute to widen our knowledge about the behaviour of metals in coastal areas and to determine how the presence of DOM affects their toxicity

    EFFECT OF DISSOLVED ORGANIC MATTER ON COPPER BIOAVAILABILITY TO A COASTAL DINOFLAGELLATE

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    Metal complexation by dissolved organic matter (DOM) is considered to decrease metal bioavailability by lowering the free metal ion concentration, therefore protecting organisms from the deleterious effects of metals (Campbell et al., 2002). In coastal lagoons like Mar Menor, with high terrestrial influence and low exchange with open sea, the levels of both DOM and metals are one or two orders of magnitude higher than in open-waters. In order to verify the free ion activity model (FIAM), copper internalization by Prorocentrum micans, a cosmopolitan dinoflagellate also present in the Mar Menor, was tested in the absence and presence of two types of DOM, commercially available fulvic acids from riverine origin (SRFA) and coastal DOM obtained by ultrafiltration (UF-DOM). The microalgae were exposed to artificial sea water enriched with increasing amounts of Cu65 isotope, at levels from 5 to 100 nM Cu, solely and in combination with DOM. After one-hour exposure, samples were centrifuged and washed and pellets were digested with nitric acid at 90ºC, following Sánchez-Marín et al (2010) and Croteau and Luoma (2005). In parallel, careful measurements of metal complexation by anodic stripping voltammetry (ASV) were performed and total Cu concentrations were measured by ICP-MS. Preliminary results show that copper internalization by the microalgae increases linearly as a function of labile Cu, both in the absence and presence of DOM, in agreement with FIAM and with labile Cu measurements performed by ASV. Future work might include testing the influence of competing metals, such as Pb or Zn, on Cu internalization, and to study Cu bioavailability in natural samples collected in the Mar Menor, in order to shed light into the factors that control Cu bioavailability in coastal lagoons

    COPPER AND LEAD COMPLEXATION BY DISSOLVED ORGANIC MATTER IN MAR MENOR COASTAL LAGOON

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    Mar Menor coastal lagoon is a shallow system with a reduced exchange with the open sea, that is affected by several anthropogenic pressures, mainly agriculture and mining. The mining sierra of Cartagena-La Unión has been historically discharging mining waste rich in heavy metals in the south area of Mar Menor, resulting in high metal concentrations in sediments (García and Muñoz-Vera., 2015). The nutrients reaching the lagoon, together with the high temperatures, also provoke phytoplankton blooms that lead to high concentrations of dissolved organic matter (DOM). It is well known that total metal concentrations are not good predictors of their bioavailability, and metal speciation should be taken into account. The presence of ligands, such as DOM in the water, may form metal-DOM complexes and protect against the deleterious effects of metals. The present study aims at studying the effect of DOM on the speciation of dissolved metals (Cu and Pb) in Mar Menor waters. With that aim, filtered water was sampled at five sites in Mar Menor lagoon at several sampling periods. Metal concentration was analysed by ICP-MS with Argon gas dilution, DOC was analysed in a carbon-specific infrared gas analyser and optical characterization of DOM was obtained from absorbance and fluorescence spectra. Complexiometric titrations of Cu and Pb were performed by anodic stripping voltammetry following Durán and Nieto (2011). Preliminary results show that Cu and Pb concentrations in Mar Menor waters are higher than in other coastal areas, especially in the south area of the lagoon, reaching concentrations of tens of nanomolar. DOC concentrations are also very high in Mar Menor waters, leading to high complexation capacities for Cu, therefore protecting aquatic biota from the deleterious effects of Cu. Pb, on the contrary, is poorly complexed by DOM, and almost all dissolved Pb is present in inorganic forms

    Healthy aging and late-life depression in Europe: Does migration matter?

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    Background: There is limited research examining the impact of risk and protective factors on late-life depression using large population-based datasets, particularly those examining differences among older migrants and non-migrants in Europe countries. Thus, the first aim was to analyze differences between migrants and non-migrants regarding socioeconomic status, depression, multimorbidity, healthy aging, and lifestyle behaviors. The second aim was to examine the impact of healthy aging on late-life depression in older migrants compared to their counterparts without a history of international migration in extensive and harmonized data from different population-based cohort studies. Materials and methods: We analyzed cross-sectional, predominantly nationally representative, community-based data from European participants in the Aging Trajectories of Health: Longitudinal Opportunities and Synergies (ATHLOS) cohort. The descriptive analyses included sociodemographic variables, somatic comorbidities, multimorbidity, healthy aging, and lifestyle behaviors according to migration status. The effects of these variables on late-life depression were examined in a multivariate logistic regression model, including migration status and years since migration as predictors. Results: Data of 122,571 individuals aged = 50 years were analyzed, of which 11,799 (9.60%) were migrants. The descriptive analyses indicated that compared to non-migrants, migrants showed a higher prevalence of diabetes (25.6%), hypertension (38.0%), coronary artery disease (49.4%), stroke (4.9%), and depression (31.1%). Healthy aging was also better in non-migrants (51.7; SD = 9.7) than in migrants (39.6; SD = 18.2). The results of the logistic regression showed that migration status [OR = 1.231 (CIs: 0.914–1.547)] and increased number of years since migration in the host country [OR = 0.003 (CIs: 0.001–0.005)] were associated with greater levels of depressive symptoms. Concerning health variables, multimorbidity was associated with higher levels of depressive symptoms [OR = 0.244 (CIs: 0.211–0.278)], whereas better healthy aging was associated with fewer depressive symptoms [OR = -0.100 (CIs: -0.102 to -0.098)]. The interaction between migration and healthy aging status was also significant [OR. = -0.019 (CIs: -0.025 to -0.014)]. Conclusion: Migrants reported higher risks for worse health outcomes compared to non-migrants. Significantly, worse healthy aging was associated with a greater risk of depressive symptoms in migrants than in non-migrants. Shedding light on migration and aging processes is essential for promoting a cross-cultural understanding of late-life depression in EuropeDF’s work was supported by grant 2017 SGR 622 (GRBIO) administrated by the Departament d’Economia i Coneixement de la Generalitat de Catalunya (Spain), by Marsden grant E2987-3648 administrated by the Royal Society of New Zealand, and by the Ministerio de Ciencia e Innovación (Spain) [PID2019-104830RB-I00/DOI (AEI): 10.13039/501100011033]Peer ReviewedPostprint (published version

    Integrin-Linked Kinase Expression in Human Valve Endothelial Cells Plays a Protective Role in Calcific Aortic Valve Disease.

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    Calcific aortic valve disease (CAVD) is highly prevalent during aging. CAVD initiates with endothelial dysfunction, leading to lipid accumulation, inflammation, and osteogenic transformation. Integrin-linked kinase (ILK) participates in the progression of cardiovascular diseases, such as endothelial dysfunction and atherosclerosis. However, ILK role in CAVD is unknown. First, we determined that ILK expression is downregulated in aortic valves from patients with CAVD compared to non-CAVD, especially at the valve endothelium, and negatively correlated with calcification markers. Silencing ILK expression in human valve endothelial cells (siILK-hVECs) induced endothelial-to-mesenchymal transition (EndMT) and promoted a switch to an osteoblastic phenotype; SiILK-hVECs expressed increased RUNX2 and developed calcified nodules. siILK-hVECs exhibited decreased NO production and increased nitrosative stress, suggesting valvular endothelial dysfunction. NO treatment of siILK-hVECs prevented VEC transdifferentiation, while treatment with an eNOS inhibitor mimicked ILK-silencing induction of EndMT. Accordingly, NO treatment inhibited VEC calcification. Mechanistically, siILK-hVECs showed increased Smad2 phosphorylation, suggesting a TGF-β-dependent mechanism, and NO treatment decreased Smad2 activation and RUNX2. Experiments performed in eNOS KO mice confirmed the involvement of the ILK-eNOS signaling pathway in valve calcification, since aortic valves from these animals showed decreased ILK expression, increased RUNX2, and calcification. Our study demonstrated that ILK endothelial expression participates in human CAVD development by preventing endothelial osteogenic transformationpost-print4615 K

    Bisphenol A Induces Accelerated Cell Aging in Murine Endothelium.

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    Bisphenol A (BPA) is a widespread endocrine disruptor affecting many organs and systems. Previous work in our laboratory demonstrated that BPA could induce death due to necroptosis in murine aortic endothelial cells (MAECs). This work aims to evaluate the possible involvement of BPA-induced senescence mechanisms in endothelial cells. The β-Gal assays showed interesting differences in cell senescence at relatively low doses (100 nM and 5 µM). Western blots confirmed that proteins involved in senescence mechanisms, p16 and p21, were overexpressed in the presence of BPA. In addition, the UPR (unfolding protein response) system, which is part of the senescent phenotype, was also explored by Western blot and qPCR, confirming the involvement of the PERK-ATF4-CHOP pathway (related to pathological processes). The endothelium of mice treated with BPA showed an evident increase in the expression of the proteins p16, p21, and CHOP, confirming the results observed in cells. Our results demonstrate that oxidative stress induced by BPA leads to UPR activation and senescence since pretreatment with N-acetylcysteine (NAC) in BPA-treated cells reduced the percentage of senescent cells prevented the overexpression of proteins related to BPA-induced senescence and reduced the activation of the UPR system. The results suggest that BPA participates actively in accelerated cell aging mechanisms, affecting the vascular endothelium and promoting cardiovascular diseases.post-print3206 K
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