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Development and characterization of a chicory extract fermented by Akkermansia muciniphila: An in vitro study on its potential to modulate obesity-related inflammation
No full textInternational audienceObesity, the fifth leading cause of death globally and linked to chronic low-grade inflammation and development of numerous severe pathologies, is a major public health problem. Fermented foods, probiotics, and postbiotics emerge as promising avenues for combating obesity and inflammation. The aim of our study was to develop and characterize phyto-postbiotics corresponding to prebiotic compounds fermented by gut bacteria, which could act on obesity and related-inflammation. Chicory extract fermented by Akkermansia muciniphila (C-Akm) was selected as the most antioxidant of 20 fermented extracts. The identification of metabolites derived from C-Akm extract has enabled us to detect mostly amino acids, acids, and some polyphenols (daidzein and genistein). The anti-inflammatory and anti-obesity activities of C-Akm extract were studied by testing the extract (50 μg/mL) on the polarization of THP-1 into macrophages, the secretion of pro-inflammatory cytokines in LPS-stimulated PBMCs, and the secretion of leptin and adiponectin in adipospheroids derived from human adipose stem cells. Finally, the extract was examined in 3D co-culture model mimicking inflamed obese adipose tissue. We found that C-Akm extract decreased ROS generation, TNF-α and Il-6 gene expression in polarized macrophages, INFγ and IL-17A secretion in LPS-stimulated PBMCs stimulated with LPS. It also decreased leptin expression while increasing adiponectin and HSL expression levels in both adipocytes and co-cultures. In addition, C-Akm extract stimulated adiponectin secretion in the co-culture model. Finally, our in vitro investigations demonstrated the potential benefits of C-Akm extract in the prevention and treatment of obesity-related inflammation
Markedly Enhanced Photoluminescence of Carbon Dots Dispersed in Deuterium Oxide
No full textInternational audienceIn this work we report some surprisingly interesting results in our pursuit to improve the photoluminescent emission of Carbon Dots (CDs) prepared from various precursors. By simply replacing the regular water with deuterium oxide (D2O) as dispersion medium, the emission intensity and the subsequent quantum efficiency of the radiative processes could be markedly enhanced. The present study was performed on our previous reported works related to CDs; in each case the preparation path being maintained accordingly. For each type of CDs, the emission intensity and the absolute photoluminescence quantum yield (PLQY) were highly improved, in certain cases more than doubled values being recorded, the gain in performance being easily remarked with the naked eye even in plain daylight. For each type of CDs dispersed in regular water and heavy water respectively, the photoluminescent properties were thoroughly investigated through Steady State, Lifetime and absolute PLQY. To further elucidate the mechanism involved in the photoluminescence intensity enhancement, samples of D2O and H2O dispersed CDs were embedded in a crosslinked Poly(acrylic acid) polymer matrix. The investigations revealed the major influence of the deuterium oxide dispersion medium over the PL emission properties of the investigated CDs.</div
FESTIVAL CULTUREL, VALORISATION TOURISTIQUE DU PATRIMOINE ET DÉVELOPPEMENT LOCAL : CAS DE LA LOCALITÉ D'ABÉNÉ (BASSE CASAMANCE/SÉNÉGAL)
No full textInternational audienceLa valorisation de la culture et du patrimoine à travers des festivals constitue un atout pour le développement socio-culturel et économique des territoires. L'objectif de cette étude est d'analyser l'apport de Abéné festivalo sur le développement local. Elle s'appuie sur une approche quantitative (enquête) et qualitative (entretien et observation) pour évaluer la perception de la population et des responsables de structures d'hébergement. Les résultats montrent un bilan satisfaisant, cent pourcent des enquêtés du côté de la population et des hôteliers affirment que le festival a permis le développement du village, et respectivement 79 % et 85 % indiquent participer à l'organisation du festival. Cependant, 88 % des enquêtés dans la population et 61 % des hôteliers pensent que l'activité touristique et le festival ont des impacts négatifs sur la population. Parmi ceux-ci, 72 % des enquêtés dans la population parlent de l'augmentation du niveau de vie, 67 % mentionnent la prostitution et l'adduction aux drogues, 58 % évoquent la perversion sociale, 41 % citent l'adaptation des activités culturels au tourisme, 44 % allèguent la débauche au tourisme sexuel et 17 % nomment les conflits entre acteurs. Malgré ces effets négatifs, 100 % des enquêtés pensent que ce festival est un véritable moyen de rencontre et de partage entre populations et touristes
SDHI : ces pesticides agricoles qui inquiètent les scientifiques
No full textNational audienceSDHI : ces pesticides agricoles qui inquiètent les scientifique
Enumeration of walks in multidimensional orthants and reflection groups
No full text30 pagesWe consider (random) walks in a multidimensional orthant. Using the idea of universality in probability theory, one can associate a unique polyhedral domain to any given walk model. We use this connection to prove two sets of new results. First, we are interested in a group of transformations naturally associated with any small step model; as it turns out, this group is central to the classification of walk models. We show a strong connection between this group and the reflection group through the walls of the polyhedral domain. As a consequence, we can derive various conditions for the combinatorial group to be infinite. Secondly, we consider the asymptotics of the number of excursions, whose critical exponent is known to be computable in terms of the eigenvalue of the above polyhedral domain. We prove new results from spectral theory on the eigenvalues of polyhedral nodal domains. We believe that these results are interesting in their own right; they can also be used to find new exact asymptotic results for walk models corresponding to these nodal polyhedral domains
Evaluating ion dynamics through Coulomb and Yukawa interaction potentials in one component strongly coupled plasmas
No full textAccepted versionInternational audienceAtmospheric pressure helium plasmas are investigated employing molecular dynamics simulations at room temperature (300 K) for various ionization fractions () in the strongly coupled regime (ion coupling parameter, ). The role of electron screening in ion dynamics and energetics is examined through ion and gas temperatures, mean squared displacement of ions, ion coupling parameter, and radial distribution function of the system by implementing both Coulomb and Yukawa potentials for ionic interactions. It is found that electron screening in the Yukawa potential limits the disorder-induced heating (DIH) mechanism and the coupling strength of the ions significantly for strongly ionized plasmas (ionization fraction, ). Whereas, the ions show a prominent sub-diffusive behavior for the Coulomb potential that is associated with the DIH mechanism. DIH is explained using a simplified model based on energy conservation. Moreover, the screening effect affects the separation distance and arrangement of the ion-neutral pairs for all the values of
Approximation of non-linear Markov chains using diffusion approximations: L^1-norm estimate and application to adipose cell modelling
No full textWe introduce a class of continuous in time non-linear Markov chains with application in different applied fields such has epidemics, opinion spreading or cells dynamics. This Markov chains depends on a parameter ε which is meant to go to zero, and in the limit the Markov chains tends to a deterministic ordinary differential equation. We show that such Markov chains are 'well approximated' by diffusion approximations as in the classical result from [Kurtz, 1978], meaning that the rate of convergence to this diffusion approximation is better than the one to the deterministic limit. Particularly, our results suggests that for some application where the scaling parameter has a physical interpretation and should remain strictly positive, the diffusion approximation is more adapted to study macroscopic scale dynamics. We present an application of our result to adipose cell size dynamics
Place Making, Fire, and the Praxis of Becoming Angkor
No full textInternational audienceThis paper examines the workings of the Angkorian Khmer state through the lens of place-making, manipulation of fire and practice. To move beyond top-down or bottom-up perspectives, our study emphasizes how the actions of kings, elites and commoners underwrote general cohesion of the Angkorian state over a period of five centuries. Specifically, recent archaeological work shows the importance of place-making, through veneration of monuments and intangible sites of memory dating back centuries, and specialized high-temperature pyrotechnologies in the creation of Khmer places and objects of inclusion. We argue that the praxis of re-making the Angkorian landscape across their entire territories and control of fire represent ritualized performance that was both broadly legible to its populations and provides a more dynamic view of the traditional models of centralization and coercion
From Astronomical Computation to Astrological Interpretation: figurae caeli and ‘Astrological Squares’ in Fifteenth-Century Annual Prognostications
No full textInternational audienc
Effect of emotional valence on the memorization of written words in 4- and 5-year-olds
No full textInternational audienceThe experiment presented examines the influence of the emotional (positive, negative) and non-emotional (neutral) valence of photographs associated with the written form of words on the memorization of written words in 4-and 5-year-old children. To this end, a delayed copy task of 6 words of increasing complexity was administered. The complexity of the word to be copied from memory was determined by its length (4, 5 letters) and its orthographic complexity [consistent, regular word, word with a silent letter at the end of the word, and word with an inconsistent grapheme, itself composed of non-frequent letters in French (Y and K)]. The results of this study highlight a differential effect of emotional valence on the memorization of the written form of words in young children. More specifically, the positive valence of the photographs facilitated children's performance, compared with negative and neutral photographs. This effect of valence is influenced by the complexity of the word to be copied, particularly its length. These results shed new light on the experimental study of the influence of the emotional valence of the photographs on the memory of pre-school children