93 research outputs found

    Social Factors Modulate Toxin (LICL)-Induced Conditioned Disgust Responses in Male Rats

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    Rats, which are a non-emetic species, display conditioned disgust responses when re-exposed to a context previously associated with sickness. These conditioned disgust responses can be used to model anticipatory nausea in humans, a growing problem faced by numerous chemotherapy patients. This thesis found that social factors, in addition to contextual factors, can play a role in the expression of toxin (LiCl)-induced conditioned disgust in rats. The results show that a familiar, but not unfamiliar, social partner can serve as a cue for the display of conditioned gaping. Further, a variety of sensory cues may play a role in the development of socially-mediated conditioned disgust, as an odour cue (urine) alone was incapable of causing significant conditioned disgust. It was also found that socially-mediated conditioned disgust can be modulated by oxytocin, as an oxytocin receptor antagonist, L-368,899, significantly decreased the display of conditioned gaping. Therefore, these findings suggest that social factors can lead to the development and expression of toxin-elicited conditioned disgust responses in rats. This has implications for chemotherapy patients, as the development and expression of anticipatory nausea may also be impacted by social factors

    Clustering a medieval social network by SOM using a kernel based distance measure

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    6 pagesInternational audienceIn order to explore the social organization of a medieval peasant community before the Hundred Years' War, we propose the use of an adaptation of the well-known Kohonen Self Organizing Map to dissimilarity data. In this paper, the algorithm is used with a distance based on a kernel which allows the choice of a smoothing parameter to control the importance of local or global proximities

    Étude de la qualité de service dans un système sans-fil MIMO

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    MIMO et Qualité de Service -- Modélisation d'un canal -- Les différents types de canaux -- Modélisation du canal de communication -- Performances d'un système MIMO -- Modulation d'amplitude en quadrature -- Calcul des Rapports Signal/Bruit en sortie d'un système MIMO -- Relation entre le taux d'erreur par bit et le SNR dans le canal -- Validation du modèle théorique par la simulation -- Qualité de service (QoS) et classes de service (CoS) -- Transmission de différents flux -- Contraintes de Qualité de Service -- Choix entre Multiplexage Temporel et Multiplexage Spatial pour l'optimisation de la transmission -- Optimisation du problème de transmission en double dimension (spatiale et temporelle simultanément)

    Registering New Drugs for Low-Income Countries: The African Challenge

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    Mary Moran and colleagues discuss the best strategies for African regulators to be supported in their efforts to evaluate and approve drugs for their own populations

    Evaluation of a simple approach for crop evapotranspiration partitioning and analysis of the water budget distribution for several crop species

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    International audienceClimate variability and climate change induce important intra- and inter-annual variability of precipitation that significantly alters the hydrologic cycle. The surface water budgets and the plant or ecosystem water use efficiency (WUE) are in turn modified. Obtaining greater insight into how climatic variability and agricultural practices affect water budgets and regarding their components in croplands is, thus, important for adapting crop management and limiting water losses. Therefore, the principal objectives of this study are: (1) to assess the contribution of different components to the agro-ecosystem water budget and (2) to evaluate how agricultural practices and climate modify the components of the surface water budget. To achieve these goals, we tested a new method for partitioning evapotranspiration (ETR), measured by means of an eddy-covariance method, into soil evaporation (E) and plant transpiration (TR) based on marginal distribution sampling (MDS). The partitioning method proposed requires continuous flux recording and measurements of soil temperature and humidity close to the surface, global radiation above the canopy and assessment of leaf area index dynamics. This method is well suited for crops because it requires a dataset including long bare-soil periods alternating with vegetated periods for accurate partitioning estimation. We compared these estimations with calibrated simulations of the ICARE-SVAT double source mechanistic model. The results showed good agreement between the two partitioning methods, demonstrating that MDS is a convenient, simple and robust tool for estimating E with reasonable associated uncertainties. During the growing season, the proportion of E in ETR was approximately one-third and varied mainly with crop leaf area. When calculated on an annual time scale, the proportion of E in ETR reached more than 50%, depending on the crop leaf area and on the duration and distribution of bare soil within the year

    Sur l'analyse de réseaux de sociabilité de la société paysanne médiévale

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    National audienceL'histoire des sociétés rurales médiévales que nous connaissons a été construite à partir des traces qui nous sont parvenues, très souvent issues de la noblesse ou l'église de cette époque. De ce fait, le monde paysan, qui représente 90% de la population, est assez mal connu. L'étude d'une de ces sociétés, focalisée sur une zone géographique restreinte couverte par une documentation abondante, nous permet de reconstituer des réseaux de sociabilités. Nous analysons ces réseaux à l'aide d'outils de visualisation et nous montrons à la fois les changements structurels liés à des événements tels que les guerres et des analogies entre les graphes associés à ces réseaux et les graphes " petit monde "

    The Dietary Antioxidant Piceatannol Inhibits Adipogenesis of Human Adipose Mesenchymal Stem Cells and Limits Glucose Transport and Lipogenic Activities in Adipocytes

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    Phenolic compounds are among the most investigated herbal remedies, as is especially the case for resveratrol. Many reports have shown its anti-aging properties and the ability to reduce obesity and diabetes induced by high-fat diet in mice. However, such beneficial effects hardly translate from animal models to humans. The scientific community has therefore tested whether other plant phenolic compounds may surpass the effects of resveratrol. In this regard, it has been reported that piceatannol reproduces in rodents the anti-obesity actions of its parent polyphenol. However, the capacity of piceatannol to inhibit adipocyte differentiation in humans has not been characterized so far. Here, we investigated whether piceatannol was antiadipogenic and antilipogenic in human preadipocytes. Human mesenchymal stem cells (hMSC), isolated from adipose tissues of lean and obese individuals, were differentiated into mature adipocytes with or without piceatannol, and their functions were explored. Fifty mu M of piceatannol deeply limited synthesis/accumulation of lipids in both murine and hMSC-derived adipocytes. Interestingly, this phenomenon occurred irrespective of being added at the earlier or later stages of adipocyte differentiation. Moreover, piceatannol lowered glucose transport into adipocytes and decreased the expression of key elements of the lipogenic pathway (PPAR gamma, FAS, and GLUT4). Thus, the confirmation of the antiadipogenic properties of piceatanol in vitro warrants the realization of clinical studies for the application of this compound in the treatment of the metabolic complications associated with obesity.This project has been partially supported by grants from Interreg POCTEFA, European Union, via Refbio-the Pyrenees Biomedical Network, also by the project PI17/02268 (Instituto de Salud Carlos III. Madrid, Spain) and by Fondo Europeo de Desarrollo Regional (FEDER) funds: "Una manera de hacer Europa"

    Optimizing an Organized Modularity Measure for Topographic Graph Clustering: a Deterministic Annealing Approach

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    This paper proposes an organized generalization of Newman and Girvan's modularity measure for graph clustering. Optimized via a deterministic annealing scheme, this measure produces topologically ordered graph clusterings that lead to faithful and readable graph representations based on clustering induced graphs. Topographic graph clustering provides an alternative to more classical solutions in which a standard graph clustering method is applied to build a simpler graph that is then represented with a graph layout algorithm. A comparative study on four real world graphs ranging from 34 to 1 133 vertices shows the interest of the proposed approach with respect to classical solutions and to self-organizing maps for graphs

    Novel Facet of an Old Dietary Molecule? Direct Influence of Caffeine on Glucose and Biogenic Amine Handling by Human Adipocytes

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    Caffeine is a plant alkaloid present in food and beverages consumed worldwide. It has high lipid solubility with recognized actions in the central nervous system and in peripheral tissues, notably the adipose depots. However, the literature is scant regarding caffeine’s influence on adipocyte functions other than lipolysis, such as glucose incorporation into lipids (lipogenesis) and amine oxidation. The objective of this study was to explore the direct effects of caffeine and of isobutylmethylxanthine (IBMX) on these adipocyte functions. Glucose transport into fat cells freshly isolated from mice, rats, or humans was monitored by determining [3H]-2-deoxyglucose (2-DG) uptake, while the incorporation of radiolabeled glucose into cell lipids was used as an index of lipogenic activity. Oxidation of benzylamine by primary amine oxidase (PrAO) was inhibited by increasing doses of caffeine in human adipose tissue preparations with an inhibition constant (Ki) in the millimolar range. Caffeine inhibited basal and insulin-stimulated glucose transport as well as lipogenesis in rodent adipose cells. The antilipogenic action of caffeine was also observed in adipocytes from mice genetically invalidated for PrAO activity, indicating that PrAO activity was not required for lipogenesis inhibition. These caffeine inhibitory properties were extended to human adipocytes: relative to basal 2-DG uptake, set at 1.0 ± 0.2 for 6 individuals, 0.1 mM caffeine tended to reduce uptake to 0.83 ± 0.08. Insulin increased uptake by 3.86 ± 1.11 fold when tested alone at 100 nM, and by 3.21 ± 0.80 when combined with caffeine. Our results reinforce the recommendation of caffeine’s potential in the treatment or prevention of obesity complications

    Batch kernel SOM and related Laplacian methods for social network analysis

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    Large graphs are natural mathematical models for describing the structure of the data in a wide variety of fields, such as web mining, social networks, information retrieval, biological networks, etc. For all these applications, automatic tools are required to get a synthetic view of the graph and to reach a good understanding of the underlying problem. In particular, discovering groups of tightly connected vertices and understanding the relations between those groups is very important in practice. This paper shows how a kernel version of the batch Self Organizing Map can be used to achieve these goals via kernels derived from the Laplacian matrix of the graph, especially when it is used in conjunction with more classical methods based on the spectral analysis of the graph. The proposed method is used to explore the structure of a medieval social network modeled through a weighted graph that has been directly built from a large corpus of agrarian contracts
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