480 research outputs found

    Editorial: Emerging topics in coastal and transitional ecosystems: science, literacy, and innovation

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    Marine coastal and transitional ecosystems are facing increasing impacts, and often reflect the most immediate effects of environmental change, habitat destruction, and biodiversity loss. With over half of the population currently living in coastal areas, these areas are of interest for multiple uses and resources, as well as subjected to multiple stressors and associated impacts derived from local and upstream anthropogenic activities. The challenges coastal and transitional ecosystems now face is not new and have far-reaching implications for the ocean (Borja et al.). Nevertheless, significant knowledge gaps on their functioning and structure still exist and new solutions or approaches to this old problem are still needed, from blue biotechnological innovations to improved ocean literacy (Borja et al.). This Research Topic aimed to contribute to the sustainability of coastal and transitional environments, providing a broad overview of ecosystem resources and functioning, assessment and monitoring tools, restoration, biotechnology, and ocean literacy. A growing human population has also increased the reliance on the sea for food and feed resources. Despite soaring demand, the management of seafood resources is still hampered by key knowledge gaps on many life-history traits of target species as well as on ecosystem’s functioning (Golden et al., 2021). From tropical regions, where mangroves function as nursery habitats for various crustaceans and fish species, contributing to maintaining adjacent marine stocks, a poorly studied system on Príncipe Island, Gulf of Guinea, evidenced the importance of seasonality and mangrove zone on fish assemblages (Cravo et al.). In the deep sea, a particular challenge to commercial exploitation of fish species is how changing environmental conditions affect these organisms, which are generally characterized by high longevity, late reproduction, and low fecundity.info:eu-repo/semantics/publishedVersio

    Water and otolith chemistry: implications for discerning estuarine nursery habitat use of a juvenile flatfish

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    Variations in otolith elemental composition are widely used to reconstruct fish movements. However, reconstructing habitat use and environmental histories of fishes within estuaries is still a major challenge due to the dynamic nature of these coastal environments. In this study, we performed a laboratory experiment to investigate the effects of variations in salinity (three levels; 5, 18, 30) and temperature (two levels; 16, 21 C) on the otolith elemental composition (Mg:Ca, Mn:Ca, Sr:Ca, Ba:Ca) of juvenile Senegalese sole Solea senegalensis. Temperature and salinity treatments mirrored the natural conditions of the estuarine habitats occupied by juvenile Senegalese sole, thereby providing information on the applicability of otolith microchemistry to reconstruct habitat use patterns within estuarine nurseries, where individual fish move across complex salinity and temperature gradients. While Sr:Ca and Ba:Ca in otoliths were both positively related to salinity, no temperature effect was observed. Partition coefficients, proxies for element incorporation rates increased with increasing salinity for Sr (DSr) and Ba (DBa). In contrast, salinity and temperature had little influence on otolith Mn:Ca and Mg:Ca, supporting physiological control on the incorporation of these elements. Our results are a stepping stone for the interpretation of otolith chemical profiles for fish collected in their natural habitats and contribute to better understanding the processes involved in otolith element incorporation.info:eu-repo/semantics/publishedVersio

    Características morfológicas e estudo da vascularização do corpo lúteo cíclico de cabras ao longo do ciclo estral

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    Corpus luteum is a temporary endocrine gland that regulates either the estrous cycle and pregnancy. It presents extreme dependency on the adequate blood supply. This work aims to evaluate goat corpus luteum (CL) vascular density (VD) over the estrous cycle. For that purpose, 20 females were submitted to estrus synchronization/ovulation treatment using a medroxyprogesterone intra-vaginal sponge as well as intramuscular (IM) application of cloprostenol and equine chorionic gonadotrophine (eCG). After sponge removal, estrus was identified at about 72hs. Once treatment was over, female goats were then subdivided into 4 groups (n=5 each) and slaughtered on days 2, 12, 16 and 22 after ovulation (p.o). Ovaries were collected, withdrawn and weighted. CL and ovaries had size and area recorded. Blood samples were collected and the plasma progesterone (P4) was measured through RIA commercial kits. The VD was 24.42±6.66, 36.26±5.61, 8.59±2.2 and 3.97±1.12 vessels/mm² for days 2, 12, 16 and 22 p.o, respectively. Progesterone plasma concentrations were 0.49±0.08, 2.63±0.66, 0.61±0.14 and 0.22±0.04ng/ml for days 2, 12, 16 e 22 p.o, respectively. Studied parameters were affected by the estrous cycle phase. Values greater than 12 p.o were observed. In the present work we observed that ovulation occurred predominantly in the right ovary (70% of the animals), which in turn presented bigger measures than the contra lateral one. There is a meaningful relationship between the weight and size of the ovary and these of CL (r=0.87, r=0.70, respectively, p<0.05). It is possible to conclude that morphology of goat's ovaries and plasma progesterone concentration changed according to estrous cycle stages. We propose these parameters can be used as indicators of CL functional activity.O corpo lúteo é uma glândula endócrina temporária que regula tanto o ciclo estral quanto a prenhez, apresentando extrema dependência de aporte sanguíneo adequado. Objetivaram-se avaliar mudanças morfométricas dos ovários e densidade vascular (DV) dos corpos lúteos (CL) de cabras ao longo do ciclo estral (AOLC). Vinte animais foram submetidos ao tratamento para indução/sincronização do estro, usando esponjas intravaginais commedroxiprogesterona, associadas a aplicações intramusculares de cloprostenol e gonadotrofina coriônica eqüina. Após remoção das esponjas, o estro foi identificado em aproximadamente de 72h. Concluído o tratamento, as cabras foram subdivididas em 4 grupos (n=5 cada) para abate nos dias 2, 12, 16 e 22 após ovulação (p.o.). Posteriormente, foram retirados os ovários e realizadas as mensurações de peso, tamanho e área do órgão e dos CL. Amostras de sangue foram coletadas e a progesterona sérica (P4) mensurada utilizando-se RIA convencional. A DV média dos CL AOLC foi 24,42±6,66; 36,26±5,61; 8,59±2,2 e 3,97±1,12 vasos/mm2 para os dias 2, 12, 16 e 22 p.o., respectivamente. A concentração média de P4 foi de 0,49±0,08; 2,63±0,66; 0,61±0,14 e 0,22±0,04ng/ml para os dias 2, 12, 16 e 22 p.o., respectivamente. Os parâmetros em estudo também se mostraram afetados pela fase do ciclo estral, sendo observados os maiores (p < 0,05) valores no dia 12 p.o. Neste experimento, a ovulação ocorreu predominantemente no ovário direito (70% dos animais), o qual apresentou medidas maiores que o contralateral. Observou-se ainda alta correlação significativa entre o peso do ovário e o do CL (r=0,87; p<0,05) e entre o tamanho destes órgãos (r=0,70; p<0,05). Conclui-se que, a morfologia dos ovários de cabras e a concentração sérica de progesterona variam em função da fase do ciclo estral e podem ser utilizadas como parâmetro na avaliação funcional do órgão

    Deliverable D4.4-5: Precision and behaviour of fish-based ecological quality metrics in relation to natural and anthropogenic pressure gradients in European estuaries and lagoons

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    This report summarises the work conducted in Work Package 4.4 – BQE fish in transitional (i.e. estuarine and lagoon) waters (TW) within the project WISER under the sponsorship of the European Commission. It omits most technical details of the analyses given in the four previous Work Package reports, but still provides the necessary information to understand the rationale, approach and underlying assumptions necessary to discuss the results. The focus is therefore to discuss and integrate the results obtained within Work Package 4.4 and with this, make recommendations to improve fish-based ecological assessments in TW, principally estuaries and lagoons. In addition, and to assist with the WFD implementation which is the overarching theme of WISER, the deliverable includes, where appropriate, case studies where we have used multi-metric fish indices currently under development, or already in use for WFD compliance monitoring across Europe. Furthermore, results of the work package have been shared with relevant Geographical Intercalibration Groups (GIGs) supporting the harmonization and equalization process across transitional fish indices in Europe. Development strategies for fish indices in TW vary but generally include: (1) the calibration of metrics to anthropogenic pressures, (2) the development of reference conditions, (3) the calculation of ecological quality ratios, and (4) the designation of thresholds for Ecological Status (ES) class. New fish indices are developed for a defined geographical area, using specific sampling method and under locally relevant pressure fields. The former two factors, area and sampling methods, define the relevant reference condition in the calculation of Ecological Quality Ratios (EQR) and the latter factor, human pressures, define the índex structure and especially the fish metric selection. To assess index relevance across areas, we calculated a suite of transitional fish indices on a standardized WISER dataset and then compared the agreement of the outcomes (using correlation analysis). The application of current indices to areas (or countries) different from the area in which it was originally developed leads to inconclusive or spurious results. The failure to accommodate the diferente indices to a standardized dataset in this work clearly demonstrates the fundamental reliance of current fish indices on the sampling methods and design of monitoring programmes used in the development of the index. Despite this, for some indices, correlations although weaker are statistically significant, also indicating the possible agreement in successful intercalibration between these indices. Harmonization of BQE fish methodologies across Europe (common metrics) is unlikely by adapting or creating new fish indices but inter-comparison assessments are possible and valid using a common pressure index to harmonise diferente indices on a common scale. We found a negative response of fish quality features to pressure gradients which make BQE fish in TW suitable for greater ecological integration than other BQEs. However, successful assessment of Ecological Status (ES) require a matching combination of fish index, reference values and local dataset gathered with compatible sampling methods. Whole indices provide more consistent overall ES assessments but fish metrics considered individually may be more useful as a means to focus restoration measures. Future work is needed to identify those specific pressures affecting fish assemblages providing targets for minimising the effects of stress in mitigation and restoration plans. In order to achieve this, and although the interpretation of outcomes is still difficult, more recent transitional fish indices are leading in the use of comprehensive appraisal and validation exercises to test the responsiveness of BQEs for the assessment of ES. Here we proposed for the first time a simple sensitivity exercise under realistic scenarios of metric change to explore the expected inertia (i.e. the tendency to buffer ES change after quality alterations), dynamic range (i.e. the ratio between the largest and smallest possible ES values) and most relevant metric components (i.e. the those driving the most likely scenarios leading to ES change) from a multi-metric fish índex under relevant human pressure gradients. Overall, the behaviour of multi-metric índices under manipulations of metric scores clearly indicated that metric type, number of metrics used and correlations between metrics are important in determining the index performance, with indices including more and/or uncorrelated metrics or metrics with skewed distribution being less affected by extreme metric manipulations. Results of this analysis may be used to set realistic management targets and also to identify the aspects of the indices that are more likely to affect the outcomes leading to more robust and responsive indices. Further improvements of fish indices may be attained by reducing the variability confounding biological quality metrics. This variability is undesirable noise in assessments and can be technical (i.e. linked to the method of assessment including sampling effort) or natural (physicochemical and biological). The implication for assessments is that different facts might then confound the metric-pressure correlation (the ‘signal’ in the signal-to-noise ratio in the assessments) increasing uncertainty in ES assignment. Models showed that salinity class, depth, season, time of fishing (day vs. night) and year of fishing may influence the values of the fish metrics. The modelling exercise also demonstrated that unexplained variance remains generally much higher within-systems than between-systems suggesting a higher importance of sources of variability acting at the WB level. Modelling and improved standardization in monitoring campaigns should reduce uncertainty in ES assignment. One important factor that was assessed further was the effect of sampling effort. The results suggest that richness-based metrics require larger sampling efforts although a similar effortrelated bias may be an issue for density-based metrics if fish distribution is very patchy (i.e. schooling fish or those aggregated in specific habitats) and insufficient replicates are taken to fully characterise the patchiness in their distribution. It is apparent that to overcome a potential large source of error, the Reference Conditions must be defined according to the level of effort used in the monitoring programme or, conversely, the monitoring must be carried out at the same level of effort used to derive the Reference Condition. The WP finally explored the use of a predictive linear modelling approach to define reference conditions for fish metrics in transitional waters. The fish response data was modelled together with Corine Land Cover (CLC)-derived pressure proxies (% agricultural, urban and natural land coverage). Based on the obtained models, the expected metric score was predicted by setting pressure levels either to the lowest observed pressure in the dataset or to zero in order to define the sample and theoretical reference condition, respectively. Even when significant, the effect of pressures on fish metrics was generally very weak, probably reflecting the use of too-generic pressure indicators (such as land cover data instead of more relevant estuarine proxies such as dredging, port development, waterborne pollutants, etc). The best explanatory models included sampling factors and natural characteristics considered important discriminant features in the definition of water body types. In particular, the present work argues for considering not only estuaries and lagoons as different typologies but also other natural and design characteristic such as the gear type, the sampling season and the salinity class. Furthermore, a relevant reference needs to account for survey design bias, including rare species contribution to assessment datasets, patchiness, choice of pressure proxies or sampling gear. The modelling approach of fish metrics against the physicochemical variables has proved useful to derive Reference Conditions. This is important for the computation of relevant EQRs in Europe where there is a general lack of pristine areas or historical data on fish BQE and it provides an alternative to best professional judgment. Taking all WP analysis and case studies together, the work conducted has highlighted the following key messages and linked research needs necessary to optimize BQE fish for the quality assessment of transitional waters: Key Message 01: Harmonization of BQE fish methodologies across Europe (common metrics) is unlikely by adapting or creating new fish indices but inter-comparison assessments are possible and valid using a common pressure index to harmonise diferente indices on a common scale. Research needs to be focused on more widely-applicable fish indices will require the formulation of completely new indices based on a more flexible use of fish metrics according to system typologies, relevance and, probably, an increased use of functional traits. For current indices, further research on a method of intercalibration is needed. Key Message 02: BQE Fish in TW respond consistently to human pressure gradients across transitional waters providing the means to assess Ecological Status (ES). Further work will be needed to identify those specific pressures affecting fish assemblages providing targets for minimising the effects of stress in mitigation and restoration plans. Key Message 03 Although the interpretation of outcomes is still difficult, more recente transitional fish indices are leading in the use of comprehensive appraisal and validation exercises to test the performance of BQEs in the assessment of Ecological Status (ES). Further appraisal of fish indices behaviour is needed to understand the meaning of the quality outcomes, to set realistic management targets and also to identify the aspects of the índices that are more likely to affect the outcomes leading to more robust and responsive indices Key Message 04 Uncertainty levels associated with metric variability in multi-metric fish indices can be managed to increase the confidence in Ecological Status (ES) class assignment. Further research is needed to include knowledge of habitat partition within systems, to understand metrics behaviour and precision, to test new combination rules allowing metric weighting by robustness and importantly to evaluate more robust sampling tools and methods. Key Message 05 Reference conditions for BQE fish-based quality assessments can be objectively estimated using predictive modelling. Further refinements will require the use of better pressure proxies, robust metrics amenable to modelling and to account for survey design bias (effort & choice of sampling gear) at the relevant scales used in monitoring programmes.info:eu-repo/semantics/publishedVersio

    Design, Synthesis and Biological Evaluation of Novel Triazole N-acylhydrazone Hybrids for Alzheimer's Disease

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    Alzheimer's disease (AD) is a multifactorial neurodegenerative disorder that involves different pathogenic mechanisms. In this regard, the goal of this study was the design and synthesis of new compounds with multifunctional pharmacological activity by molecular hybridization of structural fragments of curcumin and resveratrol connected by an N-acyl-hydrazone function linked to a 1,4-disubstituted triazole system. Among these hybrid compounds, derivative 3e showed the ability to inhibit acetylcholinesterase activity, the intracellular formation of reactive oxygen species as well as the neurotoxicity elicited by Aβ42 oligomers in neuronal SH-SY5Y cells. In parallel, compound 3e showed a good profile of safety and ADME parameters. Taken together, these results suggest that 3e could be considered a lead compound for the further development of AD therapeutics

    Kinin B(1) receptor deficiency leads to leptin hypersensitivity and resistance to obesity

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    OBJECTIVE-Kinins mediate pathophysiological processes related to hypertension, pain, and inflammation through the activation of two G-protein-coupled receptors, named B(1) and B(2). Although these peptides have been related to glucose homeostasis, their effects on energy balance are still unknown.RESEARCH DESIGN and METHODS-Using genetic and pharmacological strategies to abrogate the kinin B(1) receptor in different animal models of obesity, here we present evidence of a novel role for kinins in the regulation of satiety and adiposity.RESULTS-Kinin B(1) receptor deficiency in mice (B(1)(-/-)) resulted in less fat content, hypoleptinemia, increased leptin sensitivity, and robust protection against high-fat diet-induced weight gain. Under high-fat diet, B(1)(-/-) also exhibited reduced food intake, improved lipid oxidation, and increased energy expenditure. Surprisingly, B(1) receptor deficiency was not able to decrease food intake and adiposity in obese mice lacking leptin (ob/ob-B(1)(-/-)). However, ob/ob-B(1)(-/-) mice were more responsive to the effects of exogenous leptin on body weight and food intake, suggesting that B(1) receptors may be dependent on leptin to display their metabolic roles. Finally, inhibition of weight gain and food intake by B(1) receptor ablation was pharmacologically confirmed by long-term administration of the kinin B(1) receptor antagonist SSR240612 to mice under high-fat diet.CONCLUSIONS-Our data suggest that kinin B(1) receptors participate in the regulation of the energy balance via a mechanism that could involve the modulation of leptin sensitivity.Universidade Federal de São Paulo, Dept Biophys, BR-04023062 São Paulo, BrazilUniv Mogi das Cruzes, Mogi Das Cruzes, BrazilUniversidade Federal de São Paulo, Dept Physiol, BR-04023062 São Paulo, BrazilSanofi Aventis, Montpellier, FranceUniversidade Federal de São Paulo, Dept Med, BR-04023062 São Paulo, BrazilInst Natl Sante & Rech Med, Dept Renal & Cardiac Remodeling, U858 I2MR, Toulouse, FranceUniv Toulouse 3, Inst Med Mol Rangueil, F-31062 Toulouse, FranceInst Natl Rech Agron AgroParisTech, UMR914 Nutr Physiol & Ingest Behav, Paris, FranceMax Delbruck Ctr Mol Med, Berlin, GermanyUniversidade Federal de São Paulo, Dept Biophys, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Physiol, BR-04023062 São Paulo, BrazilUniversidade Federal de São Paulo, Dept Med, BR-04023062 São Paulo, BrazilWeb of Scienc
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