1,839 research outputs found

    Effects of synbiotic supplement on human gut microbiota, body composition and weight loss in obesity

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    Targeting gut microbiota with synbiotics (probiotic supplements containing prebiotic components) is emerging as a promising intervention in the comprehensive nutritional approach to reducing obesity. Weight loss resulting from low-carbohydrate high-protein diets can be significant but has also been linked to potentially negative health effects due to increased bacterial fermentation of undigested protein within the colon and subsequent changes in gut microbiota composition. Correcting obesity-induced disruption of gut microbiota with synbiotics can be more effective than supplementation with probiotics alone because prebiotic components of synbiotics support the growth and survival of positive bacteria therein. The purpose of this placebo-controlled intervention clinical trial was to evaluate the effects of a synbiotic supplement on the composition, richness and diversity of gut microbiota and associations of microbial species with body composition parameters and biomarkers of obesity in human subjects participating in a weight loss program. The probiotic component of the synbiotic used in the study contained Lactobacillus acidophilus, Bifidobacterium lactis, Bifidobacterium longum, and Bifidobacterium bifidum and the prebiotic component was a galactooligosaccharide mixture. The results showed no statistically significant differences in body composition (body mass, BMI, body fat mass, body fat percentage, body lean mass, and bone mineral content) between the placebo and synbiotic groups at the end of the clinical trial (3-month intervention, 20 human subjects participating in weight loss intervention based on a low-carbohydrate, high-protein, reduced energy diet). Synbiotic supplementation increased the abundance of gut bacteria associated with positive health effects, especially Bifidobacterium and Lactobacillus, and it also appeared to increase the gut microbiota richness. A decreasing trend in the gut microbiota diversity in the placebo and synbiotic groups was observed at the end of trial, which may imply the effect of the high-protein low-carbohydrate diet used in the weight loss program. Regression analysis performed to correlate abundance of species following supplementation with body composition parameters and biomarkers of obesity found an association between a decrease over time in blood glucose and an increase in Lactobacillus abundance, particularly in the synbiotic group. However, the decrease over time in body mass, BMI, waist circumstance, and body fat mass was associated with a decrease in Bifidobacterium abundance. The results obtained support the conclusion that synbiotic supplement used in this clinical trial modulates human gut microbiota by increasing abundance of potentially beneficial microbial species

    Conserved Charges in the Principal Chiral Model on a Supergroup

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    The classical principal chiral model in 1+1 dimensions with target space a compact Lie supergroup is investigated. It is shown how to construct a local conserved charge given an invariant tensor of the Lie superalgebra. We calculate the super-Poisson brackets of these currents and argue that they are finitely generated. We show how to derive an infinite number of local charges in involution. We demonstrate that these charges Poisson commute with the non-local charges of the model

    On Spin Calogero-Moser system at infinity

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    We present a construction of a new integrable model as an infinite limit of Calogero models of N particles with spin. It is implemented in the multicomponent Fock space. Explicit formulas for Dunkl operators, the Yangian generators in the multicomponent Fock space are presented. The classical limit of the system is examined

    Interaction of ballistic quasiparticles and vortex configurations in superfluid He3-B

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    The vortex line density of turbulent superfluid He3-B at very low temperature is deduced by detecting the shadow of ballistic quasiparticles which are Andreev reflected by quantized vortices. Until now the measured total shadow has been interpreted as the sum of shadows arising from interactions of a single quasiparticle with a single vortex. By integrating numerically the quasi-classical Hamiltonian equations of motion of ballistic quasiparticles in the presence of nontrivial but relatively simple vortex systems (such as vortex-vortex and vortex-antivortex pairs and small clusters of vortices) we show that partial screening can take place, and the total shadow is not necessarily the sum of the shadows. We have also found that it is possible that, upon impinging on complex vortex configurations, quasiparticles experience multiple reflections, which can be classical, Andreev, or both.Comment: To appear in Phys Rev

    Ballistic propagation of thermal excitations near a vortex in superfluid He3-B

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    Andreev scattering of thermal excitations is a powerful tool for studying quantized vortices and turbulence in superfluid He3-B at very low temperatures. We write Hamilton's equations for a quasiparticle in the presence of a vortex line, determine its trajectory, and find under wich conditions it is Andreev reflected. To make contact with experiments, we generalize our results to the Onsager vortex gas, and find values of the intervortex spacing in agreement with less rigorous estimates

    Elucidating the structural composition of a Fe-N-C catalyst by nuclear and electron resonance techniques

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    Feā€“Nā€“C catalysts are very promising materials for fuel cells and metalā€“air batteries. This work gives fundamental insights into the structural composition of an Feā€“Nā€“C catalyst and highlights the importance of an inā€depth characterization. By nuclearā€ and electronā€resonance techniques, we are able to show that even after mild pyrolysis and acid leaching, the catalyst contains considerable fractions of Ī±ā€iron and, surprisingly, iron oxide. Our work makes it questionable to what extent FeN4 sites can be present in Feā€“Nā€“C catalysts prepared by pyrolysis at 900ā€‰Ā°C and above. The simulation of the iron partial density of phonon states enables the identification of three FeN4 species in our catalyst, one of them comprising a sixfold coordination with endā€on bonded oxygen as one of the axial ligands

    On generalisations of Calogero-Moser-Sutherland quantum problem and WDVV equations

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    It is proved that if the Schr\"odinger equation LĻˆ=Ī»ĻˆL \psi = \lambda \psi of Calogero-Moser-Sutherland type with L=āˆ’Ī”+āˆ‘Ī±āˆˆA+mĪ±(mĪ±+1)(Ī±,Ī±)sinā”2(Ī±,x)L = -\Delta + \sum\limits_{\alpha\in{\cal A}_{+}} \frac{m_{\alpha}(m_{\alpha}+1) (\alpha,\alpha)}{\sin^{2}(\alpha,x)} has a solution of the product form Ļˆ0=āˆĪ±āˆˆA+sinā”āˆ’mĪ±(Ī±,x),\psi_0 = \prod_{\alpha \in {\cal {A}_+}} \sin^{-m_{\alpha}}(\alpha,x), then the function F(x)=āˆ‘Ī±āˆˆA+mĪ±(Ī±,x)2log(Ī±,x)2F(x) =\sum\limits_{\alpha \in \cal {A}_{+}} m_{\alpha} (\alpha,x)^2 {\rm log} (\alpha,x)^2 satisfies the generalised WDVV equations.Comment: 10 page

    Microstructural features of chromitites and ultramafic rocks of the Almaz-Zhemchuzhina deposit (Kempirsai massif, Kazakhstan) according to electron backscatter diffraction (EBSD) studies

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    Microstructural features of the main rock-forming minerals of host ultramafic rocks (olivine, orthopyroxene) and chrome spinel from ores of the Almaz-Zhemchuzhina deposit were studied using the electron backscatter diffraction method. For ultramafic rocks, statistical diagrams of the crystallographic orientation of olivine and orthopyroxene were obtained, indicating the formation of a mineral association in conditions of high-temperature subsolidus plastic flow in the upper mantle. The main mechanisms were translation gliding and syntectonic recrystallization. Olivine deformation occurred predominantly along the (010)[100] and (001)[100] systems. The textural and structural features of chromitites reflect plastic flow processes, most pronounced in lenticular-banded ores. Microstructure maps in inverse pole figure encoding show differences in the grain size composition of the ores: areas consisting of disseminated chromitites are characterized by a finer-grained structure compared to lens-shaped segregations of a massive structure. Analysis of microstructure maps shows that during the transition from disseminated to massive ores, there is a widespread development of recrystallization, adaptation of neighbouring grains to each other, resulting in homogenization of crystallographic orientation in aggregates. The data obtained develop ideas about the rheomorphic nature of chromitite segregations in ophiolite dunites. It is assumed that the coarsening of the structure of massive chromitites is critically associated with an increase in the concentration of ore grains during solid-phase segregation within a plastic flow, when individual chrome spinel grains, initially separated by silicate material, begin to come into direct contact with each other
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