Validation of a French version of the Freiburg Mindfulness Inventory - short version: relationships between mindfulness and stress in an adult population

<p>Abstract</p> <p>Background</p> <p>Whereas interest in incorporating mindfulness into interventions in medicine is growing, data on the relationships of mindfulness to stress and coping in management is still scarce. This report first presents a French validation of the Freiburg Mindfulness Inventory-short form (FMI) in a middle-aged working population. Secondly, it investigates the relationship between psychological adjustment and mindfulness.</p> <p>Methods</p> <p>Five hundred and six non-clinical middle-aged working individuals rated themselves on the self-report French version FMI and completed measures of psychological constructs potentially related to mindfulness levels.</p> <p>Results</p> <p>Results were comparable to results of the original short version. Internal consistency of the scale based on the one-factor solution was .74, and test-retest reliability was good. The one-dimensional solution as the alternative to the two-factor structure solution yielded suboptimal fit indices. Correlations also indicated that individuals scoring high on mindfulness are prone to stress tolerance, positive affects and higher self-efficacy. Furthermore, subjects with no reports of stressful events were higher on mindfulness.</p> <p>Conclusion</p> <p>These data showed that mindfulness can be measured validly and reliably with the proposed French version of the FMI. The data also highlighted the relationship between mindfulness and stress in an adult population. Mindfulness appears to reduce negative appraisals of challenging or threatening events.</p

Xylem water transport is influenced by age and winter pruning characteristics in grapevine (<i>Vitis vinifera</i>)

In order to investigate the effect of age and pruning characteristics on grapevine hydraulic conduction, a study was carried out between 2017 and 2020. Two pruning regimes (respecting or not sap flow pathways) and two vine age levels (older and younger vine plants) were considered and compared on two different vineyard plots located in French north-east Jura region and in south-west Bordeaux one. The assessment of pruning characteristics in relation to sap flow pathway was based on a visual characterization of the external wood aspect of the trunk and arms and consisted of a set of criteria involving the number, size and position of pruning wounds. Sap flow measurements of entire vine plants were carried out using the Xyl’em® tool, as well as an assessment of the necrotized, living and conductive xylem area in the trunks and arms after Phloxine staining. The biomass of the vegetation was also assessed. Results showed that vines pruned without considering the sap flow pathways had a 40-to-50% less conductive sap flow than vines pruned taking into account the sap pathway. No difference was observed with vine age within each pruning regime. However, for the vineyard plot where the amount of conductive xylem area was assessed, older vines that were not pruned to respect the sap pathways showed a smaller area of living wood as well as conductive wood than the older ones pruned to respect the sap flows. The amount of living and conductive areas of these vines was equivalent to that of younger vines pruned to respect sap pathways. These older vines also showed less vegetative biomass. These results show that pruning without taking into account the sap pathways has a negative impact on the conduction of xylem sap pathways in grapevines, both in terms of hydraulic efficiency and quantity of living and conducting tissues. However, the possible consequences of these reductions on grapevine physiological functions still need to be further investigated

Dextransucrases de la famille GH70 : investigations sur les déterminants moléculaires du contrôle de la masse molaire des dextranes produits

Glucansucrases (GS) from glycoside hydrolase family 70 (GH70) are -transglucosylases produced by lactic acid bacteria. From sucrose, an economical and abundant agro resource, they catalyze the polymerization of glucosyl residues. Depending on the enzyme specificity, α-glucans vary in terms of size, types of glucosidic bonds and degree of branching and have found multiple industrial applications mainly related to their molar mass (MM). However synthesizing polymers of controlled size with average MM ranging from 1 kg/mol to several millions g/mol and low polydispersity using one single enzyme remains challenging. Indeed, the molecular mechanisms underpinning the control of polymer size have been scarcely explored. To tackle this question, two GSs producing dextran (glucan composed of a majority of α-(1,6) linkages) were selected, and their mode of action explored via biochemical and structural analyses coupled to mutagenesis. The first enzyme selected, called DSR-M synthesizes only low molar mass (LMM) dextran (28 kg/mol) exclusively composed of -(1→6) linkages without any trace of HMM dextran (105 to 108 g/mol). In contrast, DSR-OK (second model), produces the highest MM dextran (>109 g/mol) described to date. Several 3D crystallographic structures of a truncated form of DSR-M (DSR-M2), either free or in complex with its substrate or product (isomaltotetraose) in the domain V or in the active site were solved. Such complexes were never obtained before. Noteworthy, one structure encompassed the most complete domain V reported to date. Analyses of these structures coupled to dextran synthesis monitoring, showed that the LMM dextran specificity of DSR-M2 is explained by a distributive elongation mode due to the weak affinity of its two sugar binding pockets in the domain V which interact with the growing dextran chains and allow the synthesis of dextran longer than 16 kg/mol. 15N1H NMR analyses (HSQC), for the first time performed with such a big protein, further revealed the crucial role of aromatic residues in the catalytic domain for the production of dextran from 2 to 16 kg/mol. In comparison, synthesis of HMM dextran by DSR-OK was shown to be mainly due to the sugar binding pockets of its domain V, ensuring much stronger interactions with growing dextran chains. The role of these pockets was evidenced for both enzymes, their functionality proposed to be linked to the presence of one aromatic stacking residue. Their positioning along domain V relatively to the active site is also important to promote efficient binding. All these findings highlight the cooperation between domain V and the catalytic domain for dextran elongation, offer new perspectives to acquire a deeper knowledge on this interplay and open promising strategies for GH70 enzyme engineering aiming at modulating glucan size.Les glucane-saccharases (GS) de la famille GH70 sont des enzymes produites par certaines bactéries lactiques. A partir de saccharose, substrat renouvelable et peu coûteux, elles sont capables de catalyser la synthèse d’α-glucanes, homopolysaccharides dont les propriétés diffèrent suivant la spécificité de l’enzyme (taille, type de liaisons α-osidiques, degrés de branchement). Les glucanes contenant une très grande majorité de liaisons α-(1,6), appelés dextranes, présentent de nombreuses applications industrielles qui dépendent principalement de leur taille. Cependant, la synthèse directe de dextranes de taille contrôlée (de 1 à plusieurs millions de kg/mol) avec une faible polydispersité et en utilisant une seule enzyme n’est encore pas envisageable. En effet, les mécanismes moléculaires mis en jeu pour le contrôle de la taille des polymères produits n’ont encore été que peu explorés. Dans ce contexte, deux GSs ont été sélectionnées. La première, DSR-M synthétise uniquement des dextranes de faible masse molaire (MM) (28 kg/mol) exclusivement composés de liaisons α-(1,6). A contrario, le second modèle, DSR-OK produit le plus long dextrane décrit à ce jour (>109 g/mol). La caractérisation biochimique et structurale ainsi que la construction de mutants ont permis l’exploration du mode d’action de ces deux candidats. Plusieurs structures 3D de DSR-M2 (forme tronquée de DSR-M) - sans ou en complexe avec son substrat ou ses produits (isomaltotetraose) - ont été résolues. C’est la première fois que de tels complexes sont décrits et l’une de ces structures présente le domaine V le plus complet décrit à ce jour. L’analyse de ces structures couplée au suivi cinétique de la synthèse du polymère ont montré que la spécificité de DSR-M pour la synthèse de dextranes courts s’explique par un mode d’élongation distributif dû à la faible affinité de deux poches à sucre de son domaine V envers la chaîne en cours de synthèse. Des analyses RMN (15N1H – HSQC) – jamais réalisées auparavant sur une protéine si grosse – ont également étayé l’importance de la présence de résidus aromatiques dans le domaine catalytique pour la synthèse de dextranes supérieurs à 2 kg/mol. En comparaison, la synthèse de dextranes de haute MM par DSR-OK est principalement due au plus grand nombre de poches à sucre de son domaine V, permettant d’assurer une meilleure interaction avec la chaîne en cours d’élongation. L’implication de ces poches dans la détermination de la taille du dextrane a été montrée pour les deux candidats. Leur fonctionnalité est fortement liée à la présence d’un résidu aromatique de stacking, et leur répartition le long du domaine V a aussi une influence. L’ensemble de ces résultats démontre la coopération du domaine V avec le domaine catalytique pour l’élongation des dextranes, tout en offrant de nouvelles perspectives pour approfondir la compréhension de ce mécanisme. Ils offrent également des stratégies prometteuses pour l’ingénierie d’enzyme de la famille des GH70 pour la modulation de la taille des glucanes

L'axe Mindfulness-Alexithymie chez le sujet sain soumis à un stress et chez le patient schizophrène

LE KREMLIN-B.- PARIS 11-BU Méd (940432101) / SudocPARIS-Bib. Serv.Santé Armées (751055204) / SudocSudocFranceF

Dépérissement de la Syrah : compréhension des dysfonctionnements physiologiques amenant le cep crevassé à la mort. Première partie : élaboration d'hypothèses rassemblées dans un modèle conceptuel

Thanks to a multi regional scale program, the second group of factors is being studied by IFV and its partners in order to know the determinant factors of death occurring. As a result, a conceptual model of the declining vine plant has been realized using knowledge on healthy plant physiology as well as empirical practice of the syndrome. In order to do that, about thirty experts have been surveyed and asked to conceptualize crop functioning. They have been chosen among researchers and counselors, thus allowing integration of multiple knowledge sources (topic, level of approach). Two major hypotheses reinforced by bibliography refe¬rences have thus emerged using variables and fluxes of the plant system: death is supposed to occur whether from bud disability to bud burst or over-consumption of root reserve pool both because of the cracking of the wood. In order to test the reliability of the conceptual model, the hypotheses have then been confronted to the field observations of the decline, and especially the complexity of the occurrence dyna¬mics of the symptoms. Finally, some experimental designs have been set in order to validate or invalidate these hypotheses, whose results will be presented in a coming paper. Depending on the cau¬ses of death (buds, reserves, other cause?) some aggravating factors might thus be identified and tested for their ability to prevent or delay death on currently planted declining Syrah plots

Current knowledge on Grapevine Trunk Diseases with complex etiology: a systemic approach

International audienceAmong all causes of grapevine decline, Grapevine Trunk Diseases (GTDs) are major concerns for grape growers. This paper reviews knowledge and proposes hypotheses on two major GTDs, esca and Botryosphaeria dieback, and assembles a conceptual model. The objective was to collect information into a sequence, from grapevine nursery propagation processes, through foliar symptom expression, to plant death in mature vineyards. Pathogen infection and colonization steps in woody vine tissues, and the hypotheses that have been formulated to explain the outburst of foliar symptoms, are reported and discussed. Factors that could aggravate or repress GTD symptoms and incidence expansion are also addressed. Vine physiology and pathology together could expand understanding of these diseases. Knowledge and hypotheses that need validation are summarized, and a conceptual model is proposed to explain the occurrence of symptoms and the influencing factors. The model could be useful to cope with the complexity of GTDs, and as a starting point for research to unravel knowledge gaps and suggest new disease management strategies

Le court-noué de la vigne. II - Le point sur la lutte contre la maladie à la journée "Alternative" du 28 avril 2005

National audienc

Marine-Derived Polymeric Materials and Biomimetics : An Overview

The review covers recent literature on the ocean as both a source of biotechnological tools and as a source of bio-inspired materials. The emphasis is on marine biomacromolecules namely hyaluronic acid, chitin and chitosan, peptides, collagen, enzymes, polysaccharides from algae, and secondary metabolites like mycosporines. Their specific biological, physicochemical and structural properties together with relevant applications in biocomposite materials have been included. Additionally, it refers to the marine organisms as source of inspiration for the design and development of sustainable and functional (bio)materials. Marine biological functions that mimic reef fish mucus, marine adhesives and structural colouration are explained

Processivity of dextransucrases synthesizing very-high-molar-mass dextran is mediated by sugar-binding pockets in domain V

International audienceThe dextransucrase DSR-OK from the Gram-positive bacterium Oenococcus kitaharae DSM17330 produces a dextran of the highest molar mass reported to date (?10(9) g/mol). In this study, we selected a recombinant form, DSR-OK?1, to identify molecular determinants involved in the sugar polymerization mechanism and that confer its ability to produce a very-high-molar-mass polymer. In domain V of DSR-OK, we identified seven putative sugar-binding pockets characteristic of glycoside hydrolase 70 (GH70) glucansucrases that are known to be involved in glucan binding. We investigated their role in polymer synthesis through several approaches, including monitoring of dextran synthesis, affinity assays, sugar binding pocket deletions, site-directed mutagenesis, and construction of chimeric enzymes. Substitution of only two stacking aromatic residues in two consecutive sugar-binding pockets (variant DSR-OK?1-Y1162A-F1228A) induced quasi-complete loss of very-high-molar-mass dextran synthesis, resulting in production of only 10?13 kg/mol polymers. Moreover, the double mutation completely switched the semiprocessive mode of DSR-OK?1 toward a distributive one, highlighting the strong influence of these pockets on enzyme processivity. Finally, the position of each pocket relative to the active site also appeared to be important for polymer elongation. We propose that sugar-binding pockets spatially closer to the catalytic domain play a major role in the control of processivity. A deep structural characterization, if possible with large-molar-mass sugar ligands, would allow confirming this hypothesis

Biochemical and Structural characterization of a new GH-70 enzyme from Leuconostoc citreum NRRL B-1299

International audienceGlucansucrases (GS) from glycoside hydrolase family 70 (GH70) are a-transglucosylases found in lactic acid bacteria such as Leuconostoc, Lactobacillus, Streptococcus and Weissella sp. They catalyze the polymerization of glucosyl residues from sucrose, an economical and abundant agroresource. Depending on the enzyme specificity, the α-glucans vary in terms of size, types of glucosidic bonds and degree of branching. This structure variety confers to α-glucans diverse properties, making them useful for several applications in food and pharmaceutical industries (Leemhuis et al., 2013). The sequencing of Leuconostoc citreum NRRL B-1299 genome allowed the identification of a new GS called DSR-M (Passerini et al., 2015). Whereas the majority of GS produce glucans of very high molar mass (105 to 108 Da), this enzyme synthesizes only a low molar mass dextran (around 27kDa, from 100 g/L sucrose) composed exclusively of a-(1→6) linkages. Now, by playing with the initial sucrose concentration and/or the reaction temperature, different dextrans of controlled molar mass ranging from 5 to 27 kDa can be produced, directly from sucrose and with excellent yields (Vuillemin et al. 2015). In parallel, we solved the 3D atomic structure of a truncated form of this enzyme comprising domains A, B, C and IV as well as most of the domain V also called Glucan Binding Domain. The crystal structure at 3.8 Å of the inactive mutant DSRM-D2-E715Q in complex with isomaltohexaose (IM6) (Fig. 1.) allowed us to identify new determinants, both near the catalytic site and in the domain V, that play a critical role in the molar masses of the dextran produced (from 1 to 15 kDa)