Clermont University

Clermont-Ferrand, France

Clermont University

Clermont-Ferrand, France
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Fardet A.,French National Institute for Agricultural Research | Fardet A.,Clermont University
Nutrition Research Reviews | Year: 2010

Epidemiological studies have clearly shown that whole-grain cereals can protect against obesity, diabetes, CVD and cancers. The specific effects of food structure (increased satiety, reduced transit time and glycaemic response), fibre (improved faecal bulking and satiety, viscosity and SCFA production, and/or reduced glycaemic response) and Mg (better glycaemic homeostasis through increased insulin secretion), together with the antioxidant and anti-carcinogenic properties of numerous bioactive compounds, especially those in the bran and germ (minerals, trace elements, vitamins, carotenoids, polyphenols and alkylresorcinols), are today well-recognised mechanisms in this protection. Recent findings, the exhaustive listing of bioactive compounds found in whole-grain wheat, their content in whole-grain, bran and germ fractions and their estimated bioavailability, have led to new hypotheses. The involvement of polyphenols in cell signalling and gene regulation, and of sulfur compounds, lignin and phytic acid should be considered in antioxidant protection. Whole-grain wheat is also a rich source of methyl donors and lipotropes (methionine, betaine, choline, inositol and folates) that may be involved in cardiovascular and/or hepatic protection, lipid metabolism and DNA methylation. Potential protective effects of bound phenolic acids within the colon, of the B-complex vitamins on the nervous system and mental health, of oligosaccharides as prebiotics, of compounds associated with skeleton health, and of other compounds such as -linolenic acid, policosanol, melatonin, phytosterols and para-aminobenzoic acid also deserve to be studied in more depth. Finally, benefits of nutrigenomics to study complex physiological effects of the whole-grain package, and the most promising ways for improving the nutritional quality of cereal products are discussed. © 2010 The Author.

Pizarro D.,University of Alcalá | Bartoli A.,Clermont University
International Journal of Computer Vision | Year: 2012

This paper presents a method for detecting a textured deformed surface in an image. It uses (wide-baseline) point matches between a template and the input image. The main contribution of the paper is twofold. First, we propose a robust method based on local surface smoothness capable of discarding outliers from the set of point matches. Our method handles large proportions of outliers (beyond 70% with less than 15% of false positives) even when the surface self-occludes. Second, we propose a method to estimate a self-occlusion resistant warp from point matches. Our method allows us to realistically retexture the input image. A pixel-based (direct) registration approach is also proposed. Bootstrapped by our robust point-based method, it finely tunes the warp parameters using the value (intensity or color) of all the visible surface pixels. The proposed framework was tested with simulated and real data. Convincing results are shown for the detection and retexturing of deformed surfaces in challenging images. © 2011 Springer Science+Business Media, LLC.

Carvalho F.A.,Clermont University | Carvalho F.A.,French Institute of Health and Medical Research | Aitken J.D.,Georgia State University | Vijay-Kumar M.,Georgia State University | Gewirtz A.T.,Georgia State University
Annual Review of Physiology | Year: 2012

The well-being of the intestine and its host requires that this organ execute its complex function amid colonization by a large and diverse microbial community referred to as the gut microbiota. A myriad of interacting mechanisms of mucosal immunity permit the gut to corral the microbiota in such a way as to maximize the benefits and to minimize the danger of living in close proximity to this large microbial biomass. Toll-like receptors and Nod-like receptors, collectively referred to as pattern recognition receptors (PRRs), recognize a variety of microbial components and, hence, play a central role in governing the interface between host and microbiota. This review examines mechanisms by which PRR-microbiota interactions are regulated so as to allow activation of host defense when necessary while preventing excessive inflammation, which can have a myriad of negative consequences for the host. Analysis of published studies performed in human subjects and a variety of murine disease models reveals the central theme that PRRs play a key role in maintaining a healthful stable relationship between the intestine and its microbiota. In contrast, although select genetic ablations of PRR signaling may protect against some chronic diseases, the overriding theme of studies performed to date is that perturbations of PRR-microbiota interactions are more likely to promote disease states associated with inflammation. Copyright © 2012 by Annual Reviews. All rights reserved.

Bartoli A.,Clermont University
International Journal of Computer Vision | Year: 2016

The prediction sum of squares statistic uses the principle of leave-one-out cross-validation in linear least squares regression. It is computationally attractive, as it can be computed non-iteratively. However, it has limitations: it does not handle coupled measurements, which should be held out simultaneously, and is specific to the principle of leave-one-out, which is known to overfit when used for selecting a model’s complexity. We propose multiple-exclusion PRESS (MEXPRESS), which generalizes PRESS to coupled measurements and other types of cross-validation, while retaining computational efficiency with the non-iterative MEXPRESS formula. Using MEXPRESS, various strategies to resolve overfitting can be efficiently implemented. The core principle is to exclude training data too ‘close’ or too ‘similar’ to the validation data. We show that this allows one to select the number of control points automatically in three cases: (i) the estimation of linear fractional warps for dense image registration from point correspondences, (ii) surface reconstruction from a dense depth-map obtained by a depth sensor and (iii) surface reconstruction from a sparse point cloud obtained by shape-from-template. © 2016 Springer Science+Business Media New York

We report the draft genome sequence of "Candidatus Methanomethylophilus alvus" Mx1201, a methanogen present in the human gut. It was enriched from human feces under anaerobic conditions with methanol as the substrate. Its circular genome, of around 1.7 Mb, contains genes needed for methylotrophic methanogenesis from methanol and tri-, di-, and monomethylamine.

Fungal species play extremely important roles in ecosystems. Clustered at the base of the fungal kingdom are Microsporidia, a group of obligate intracellular eukaryotes infecting multiple animal lineages. Because of their large host spectrum and their implications in host population regulation, they influence food webs, and accordingly, ecosystem structure and function. Unfortunately, their ecological role is not well understood. Present also as highly resistant spores in the environment, their characterisation requires special attention. Different techniques based on direct isolation and/or molecular approaches can be considered to elucidate their role in the ecosystems, but integrating environmental and genomic data (for example, genome architecture, core genome, transcriptional and translational signals) is crucial to better understand the diversity and adaptive capacities of Microsporidia. Here, we review the current status of Microsporidia in trophic networks; the various genomics tools that could be used to ensure identification and evaluate diversity and abundance of these organisms; and how these tools could be used to explore the microsporidian life cycle in different environments. Our understanding of the evolution of these widespread parasites is currently impaired by limited sampling, and we have no doubt witnessed but a small subset of their diversity.Heredity advance online publication, 3 September 2014; doi:10.1038/hdy.2014.78.

Lohou C.,Clermont University
Computer Vision and Image Understanding | Year: 2010

In 1996, Ma and Sonka proposed a thinning algorithm which yields curve skeletons for 3D binary images [C. Ma, M. Sonka, A fully parallel 3D thinning algorithm and its applications, Comput. Vis. Image Underst. 64 (3) (1996) 420-433]. This algorithm is one of the most referred thinning algorithms in the context of digital topology: either by its use in medical applications or for comparisons with other thinning algorithms. In 2007, Wang and Basu [T. Wang, A. Basu, A note on 'a fully parallel 3D thinning algorithm and its applications', Pattern Recognit. Lett. 28 (4) (2007) 501-506] wrote a paper in which they claim that Ma and Sonka's 3D thinning algorithm does not preserve topology. As they highlight in their paper, a counter-example was given in 2001, in Lohou's thesis [C. Lohou, Contribution à l'analyse topologique des images: étude d'algorithmes de squelettisation pour images 2D et 3D selon une approche topologie digitale ou topologie discrète. Ph.D. thesis, University of Marne-la-Vallée, France, 2001]. In this paper, it is shown how P-simple points have guided the author towards a proof that Ma and Sonka's algorithm does not always preserve topology. Moreover, the reasoning being very general, it could be reused for such a purpose, i.e., to simplify the proof on the non-topology preservation. © 2009 Elsevier Inc. All rights reserved.

Karmanov V.A.,RAS Lebedev Physical Institute | Mathiot J.-F.,Clermont University | Smirnov A.V.,RAS Lebedev Physical Institute
Physical Review D - Particles, Fields, Gravitation and Cosmology | Year: 2012

We present a coherent and operational strategy to calculate in a nonperturbative way, physical observables in light-front dynamics. This strategy is based on the decomposition of the state vector of any compound system in Fock components, and on the covariant formulation of light-front dynamics, together with the so-called Fock sector dependent renormalization scheme. We apply our approach to the calculation of the electromagnetic form factors of a fermion in the Yukawa model, in the nontrivial three-body Fock space truncation, for rather large values of the coupling constant. We find that once the renormalization conditions are properly taken into account, the form factors do not depend-within our numerical accuracy-on the regularization scale when the latter is much larger than the physical masses. We then extend the Fock space by including antifermion degrees of freedom. © 2012 American Physical Society.

Marchand S.,Clermont University
Ecological Economics | Year: 2012

This paper analyzes the impact of agricultural technical efficiency on the propensity of farmers to convert natural land into agricultural plots, i.e., to deforest, in the Brazilian Legal Amazon (BLA). A two-step econometric approach is adopted. A bootstrapped translog stochastic frontier that is a posteriori checked for functional consistency is used to assess technical efficiency and these estimates are put into a land-use model to assess the impact of productivity on deforestation. Analysis of agricultural census tract data suggests that technical efficiency has a U-shaped effect: both less and more efficient farms use more land for their agricultural activities and so have a positive effect on deforestation. However, the majority of farms in the BLA are on the ascendant slope, so that efficiency implies more deforestation in the BLA. The poor environmental valuation of the Brazilian forest, the uneven land distribution, and the problem of the de facto openly accessed forested and "unproductive" lands in the BLA could explain the U-shaped effect of technical efficiency on the conversion of forested land into agricultural land. © 2012 Elsevier B.V..

Oxaliplatin is an anticancer drug used for the treatment of advanced colorectal cancer, but it can also cause painful peripheral neuropathies. The pathophysiology of these neuropathies has not been yet fully elucidated, but may involve spinal N-methyl-D-aspartate (NMDA) receptors, particularly the NR2B subunit. As polyamines are positive modulators of NMDA-NR2B receptors and mainly originate from dietary intake, the modulation of polyamines intake could represent an interesting way to prevent/modulate neuropathic pain symptoms by opposing glutamate neurotransmission. The effect of a polyamine deficient diet was investigated in an animal model of oxaliplatin-induced acute pain hypersensitivity using behavioral tests (mechanical and cold hypersensitivity). The involvement of spinal glutamate neurotransmission was monitored by using a proton nuclear magnetic resonance spectroscopy based metabolomic approach and by assessing the expression and phosphorylation of the NR2B subunit of the NMDA receptor. A 7-day polyamine deficient diet totally prevented oxaliplatin-induced acute cold hypersensitivity and mechanical allodynia. Oxaliplatin-induced pain hypersensitivity was not associated with an increase in NR2B subunit expression or phosphorylation, but with an increase of glutamate level in the spinal dorsal horn which was completely prevented by a polyamine deficient diet. As a validation that the oxaliplatin-induced hypersensitivity could be due to an increased activity of the spinal glutamate system, an intrathecal administration of the specific NR2B antagonist, ifenprodil, totally reversed oxaliplatin-induced mechanical and cold hypersensitivity. A polyamine deficient diet could represent a promising and valuable nutritional therapy to prevent oxaliplatin-induced acute pain hypersensitivity.

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