109 research outputs found
Concurrent sampling of transitional and coastal waters by Diffusive Gradient in Thin-films (DGT) and spot sampling for trace metals analysis
This protocol was developed based on the knowledge acquired in the framework of the Interreg MONITOOL project (EAPA_565/2016) where extensive sampling campaigns were performed in transitional and coastal waters covering eight European countries. It provides detailed procedures and guidelines for the sampling of these waterbodies by concurrent collection of discrete water samples and the deployment of Diffusive Gradient in Thin-films (DGT) passive samplers for the measurement of trace metal concentrations. In order to facilitate the application of this protocol by end-users, it presents steps to follow in the laboratory prior to sampling campaigns, explains the procedures for field campaigns (including in situ measurement of supporting parameters) and subsequent sample processing in the laboratory in preparation for trace metal analyze by inductively coupled plasma-mass spectrometry (ICP-MS) and voltammetry. The protocol provides a systematic, coherent field sampling and sample preparation strategy that was developed in order to ensure comparability and reproducibility of the data obtained from each project Partner in different regions. • Standardization of the concurrent sampling of transitional and coastal waters by DGT passive samplers and spot sampling. • Robust procedures and tips based on existing international standards and comprehensive practical experience. • Links to demonstration videos produced within the MONITOOL project
Assessing variability in the ratio of metal concentrations measured by DGT-type passive samplers and spot sampling in European seawaters
The current study evaluates the effect of seawater physico-chemical characteristics on the relationship between the concentration of metals measured by Diffusive Gradients in Thin films (DGT) passive samplers (i.e., DGT-labile concentration) and the concentrations measured in discrete water samples. Accordingly, Inductively Coupled Plasma Mass Spectrometry (ICP-MS) was used to measure the total dissolved metal concentrations in the discrete water samples and the labile metal concentrations obtained by DGT samplers; additionally, lead and cadmium conditional labile fractions were determined by Anodic Stripping Voltammetry (ASV) and total dissolved nickel was measured by Cathodic Stripping Voltammetry (CSV). It can be concluded that, in general, the median ratios of DGT/ICP and DGT/ASV(CSV) were lower than 1, except for Ni (median ratio close to 1) and Zn (higher than 1). This indicates the importance of speciation and time-integrated concentrations measured using passive sampling techniques, which is in line with the WFD suggestions for improving the chemical assessment of waterbodies. It is the variability in metal content in waters rather than environmental conditions to which the variability of the ratios can be attributed. The ratios were not significantly affected by the temperature, salinity, pH, oxygen, DOC or SPM, giving a great confidence for all the techniques used. Within a regulatory context such as the EU Water Framework Directive this is a great advantage, since the simplicity of not needing to use corrections to minimize the effects of environmental variables could help in implementing DGTs within monitoring networks
Resolvin E1 Derived from Eicosapentaenoic Acid Prevents Hyperinsulinemia and Hyperglycemia in a Host Genetic Manner
The FASEB Journal published by Wiley Periodicals LLC on behalf of Federation of American Societies for Experimental Biology Eicosapentaenoic acid (EPA) has garnered attention after the success of the REDUCE-IT trial, which contradicted previous conclusions on EPA for cardiovascular disease risk. Here we first investigated EPA\u27s preventative role on hyperglycemia and hyperinsulinemia. EPA ethyl esters prevented obesity-induced glucose intolerance, hyperinsulinemia, and hyperglycemia in C57BL/6J mice. Supporting NHANES analyses showed that fasting glucose levels of obese adults were inversely related to EPA intake. We next investigated how EPA improved murine hyperinsulinemia and hyperglycemia. EPA overturned the obesity-driven decrement in the concentration of 18-hydroxyeicosapentaenoic acid (18-HEPE) in white adipose tissue and liver. Treatment of obese inbred mice with RvE1, the downstream immunoresolvant metabolite of 18-HEPE, but not 18-HEPE itself, reversed hyperinsulinemia and hyperglycemia through the G-protein coupled receptor ERV1/ChemR23. To translate the findings, we determined if the effects of RvE1 were dependent on host genetics. RvE1\u27s effects on hyperinsulinemia and hyperglycemia were divergent in diversity outbred mice that model human genetic variation. Secondary SNP analyses further confirmed extensive genetic variation in human RvE1/EPA-metabolizing genes. Collectively, the data suggest EPA prevents hyperinsulinemia and hyperglycemia, in part, through RvE1\u27s activation of ERV1/ChemR23 in a host genetic manner. The studies underscore the need for personalized administration of RvE1 based on genetic/metabolic enzyme profiles
Structural determinants of microtubule minus end preference in CAMSAP CKK domains
CAMSAP/Patronins regulate microtubule minus-end dynamics. Their end specificity is mediated by their CKK domains, which we proposed recognise specific tubulin conformations found at minus ends. To critically test this idea, we compared the human CAMSAP1 CKK domain (HsCKK) with a CKK domain from Naegleria gruberi (NgCKK), which lacks minus-end specificity. Here we report near-atomic cryo-electron microscopy structures of HsCKK- and NgCKK-microtubule complexes, which show that these CKK domains share the same protein fold, bind at the intradimer interprotofilament tubulin junction, but exhibit different footprints on microtubules. NMR experiments show that both HsCKK and NgCKK are remarkably rigid. However, whereas NgCKK binding does not alter the microtubule architecture, HsCKK remodels its microtubule interaction site and changes the underlying polymer structure because the tubulin lattice conformation is not optimal for its binding. Thus, in contrast to many MAPs, the HsCKK domain can differentiate subtly specific tubulin conformations to enable microtubule minus-end recognition
How can the research on chicken cognition improve chicken welfare: a perspective review
International audienceA recent definition of animal welfare states that "the welfare of an animal is its positive mental and physical state related to the fulfilment of its physiological and behavioural needs in addition to its expectations. This state can vary depending on the animal's perception of a given situation'. This definition confirms the importance of taking the individual animal perspective (i.e. its cognition) into consideration, in order to properly assess its welfare. Cognitive abilities of domestic chickens have been extensively studied in recent years, but few of these studies focussed on the relationship between chicken cognition and welfare issues commonly found in chicken production systems. Considering the chickens' cognitive abilities offers new and different perspectives on the welfare problems faced by chicken production. Combined with applied research, cognitive studies can generate impactful and science-based strategies to solve these problems better. In this short non-systematic review, we focus on cognitive research aimed at understanding three widespread welfare issues in poultry production: uneven range use in free-range broiler chickens and laying hens, feather pecking in laying hens, and the unfulfilled behavioural and physiological needs of broiler breeders. Knowledge of chicken cognitive abilities is critical to ameliorate chickens' rearing conditions and develop systems and practices that are more respectful of animal welfare
PARASITIC INFECTION AND DEVELOPMENTAL STABILITY: FLUCTUATING ASYMMETRY IN GAMMARUS PULEX INFECTED WITH TWO ACANTHOCEPHALAN SPECIES
International audienc
L'implantation de plantes médicinales sur les parcours de volailles biologiques : quels intérêts, quelles conséquences ?
National audienc
Comment les volailles perçoivent-elles leur environnement ?
Cognitive abilities bring together all of the mental processes such as attention, memory, and reasoning skills that allow an animal to understand and to adapt to its environment. They are the basis of many behaviours. In this review, in a synthetic way, we will first make an inventory of current knowledge on the cognitive capacities of domestic birds, such as hens or chickens. We will show that these birds have a diverse sensory universe, are capable of rich social interactions and of learning, among other capacities. Even if there is still research to be carried out, these birds probably have a repertoire of cognitive abilities much more extensive than what is though. In a second part, we will illustrate that this knowledge brings a new vision of our understanding of certain behaviours observed in farming systems, such as range exploration of free-range chickens, or injurious pecking in laying hens. This knowledge and this research theme, which are currently developing more and more at the international level, will contribute to a better understanding of the biology of these animals and could, in the long term, provide original avenues for promoting the adaptation of these birds to their rearing system and their welfare
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