323 research outputs found

    Effects of dietary cellobiose on the intestinal microbiota and excretion of nitrogen metabolites in healthy adult dogs

    Get PDF
    In order to evaluate the potential prebiotic effects of cellobiose, 10 healthy adult research beagle dogs received a complete diet containing 0, 0.5 and 1 g cellobiose/kg bodyweight (BW)/day. At the end of each feeding period, faeces, urine and blood of the dogs were collected. The results demonstrated a significant increase of faecal lactate concentrations, indicating a bacterial fermentation of cellobiose in the canine intestine. Along with this, a dose-dependent linear increase of the relative abundance of Lactobacillaceae in the faeces of the dogs was observed (p = 0.014). In addition, a dose-dependent increase (p < 0.05) of Alloprevotella, Bacteroides and Prevotella, and a linear decrease for unidentified Lachnospiraceae (p = 0.011) was observed when cellobiose was added to the diet, although the relative abundance of these genera was low (<1%) among all groups. The faecal pH was not affected by dietary cellobiose. Cellobiose seemed to modulate the excretion of nitrogen metabolites, as lower concentrations of phenol (p = 0.034) and 4-ethylphenol (p = 0.002) in the plasma of the dogs were measured during the supplementation periods. Urinary phenols and indoles, however, were not affected by the dietary supplementation of cellobiose. In conclusion, cellobiose seems to be fermented by the intestinal microbiota of dogs. Although no effect on the faecal pH was detected, the observed increase of microbial lactate production might lower the pH in the large intestine and consecutively modulate the intestinal absorption of nitrogen metabolites. Also, the observed changes of some bacterial genera might have been mediated by increased intestinal lactate concentrations or a higher relative abundance of lactobacilli. Whether these results could be considered as a prebiotic effect and used as a dietetic strategy in diseased animals to improve gut function or hepatic and renal nitrogen metabolism should be evaluated in future studies

    A decomposition theorem for BV functions

    Get PDF
    The Jordan decomposition states that a function f: R \u2192 R is of bounded variation if and only if it can be written as the dierence of two monotone increasing functions. In this paper we generalize this property to real valued BV functions of many variables, extending naturally the concept of monotone function. Our result is an extension of a result obtained by Alberti, Bianchini and Crippa. A counterexample is given which prevents further extensions

    A Coboundary Morphism For The Grothendieck Spectral Sequence

    Full text link
    Given an abelian category A\mathcal{A} with enough injectives we show that a short exact sequence of chain complexes of objects in A\mathcal{A} gives rise to a short exact sequence of Cartan-Eilenberg resolutions. Using this we construct coboundary morphisms between Grothendieck spectral sequences associated to objects in a short exact sequence. We show that the coboundary preserves the filtrations associated with the spectral sequences and give an application of these result to filtrations in sheaf cohomology.Comment: 18 page

    Functions of several Cayley-Dickson variables and manifolds over them

    Full text link
    Functions of several octonion variables are investigated and integral representation theorems for them are proved. With the help of them solutions of the ~{\tilde {\partial}}-equations are studied. More generally functions of several Cayley-Dickson variables are considered. Integral formulas of the Martinelli-Bochner, Leray, Koppelman type used in complex analysis here are proved in the new generalized form for functions of Cayley-Dickson variables instead of complex. Moreover, analogs of Stein manifolds over Cayley-Dickson graded algebras are defined and investigated

    Topological monoids of monotone injective partial selfmaps of N\mathbb{N} with cofinite domain and image

    Full text link
    In this paper we study the semigroup I(N)\mathscr{I}_{\infty}^{\nearrow}(\mathbb{N}) of partial cofinal monotone bijective transformations of the set of positive integers N\mathbb{N}. We show that the semigroup I(N)\mathscr{I}_{\infty}^{\nearrow}(\mathbb{N}) has algebraic properties similar to the bicyclic semigroup: it is bisimple and all of its non-trivial group homomorphisms are either isomorphisms or group homomorphisms. We also prove that every locally compact topology τ\tau on I(N)\mathscr{I}_{\infty}^{\nearrow}(\mathbb{N}) such that (I(N),τ)(\mathscr{I}_{\infty}^{\nearrow}(\mathbb{N}),\tau) is a topological inverse semigroup, is discrete. Finally, we describe the closure of (I(N),τ)(\mathscr{I}_{\infty}^{\nearrow}(\mathbb{N}),\tau) in a topological semigroup

    On the Lebesgue measure of Li-Yorke pairs for interval maps

    Get PDF
    We investigate the prevalence of Li-Yorke pairs for C2C^2 and C3C^3 multimodal maps ff with non-flat critical points. We show that every measurable scrambled set has zero Lebesgue measure and that all strongly wandering sets have zero Lebesgue measure, as does the set of pairs of asymptotic (but not asymptotically periodic) points. If ff is topologically mixing and has no Cantor attractor, then typical (w.r.t. two-dimensional Lebesgue measure) pairs are Li-Yorke; if additionally ff admits an absolutely continuous invariant probability measure (acip), then typical pairs have a dense orbit for f×ff \times f. These results make use of so-called nice neighborhoods of the critical set of general multimodal maps, and hence uniformly expanding Markov induced maps, the existence of either is proved in this paper as well. For the setting where ff has a Cantor attractor, we present a trichotomy explaining when the set of Li-Yorke pairs and distal pairs have positive two-dimensional Lebesgue measure.Comment: 41 pages, 3 figure

    On extending actions of groups

    Full text link
    Problems of dense and closed extension of actions of compact transformation groups are solved. The method developed in the paper is applied to problems of extension of equivariant maps and of construction of equivariant compactifications

    Groups of diffeomorphisms and geometric loops of manifolds over ultra-normed fields

    Full text link
    The article is devoted to the investigation of groups of diffeomorphisms and loops of manifolds over ultra-metric fields of zero and positive characteristics. Different types of topologies are considered on groups of loops and diffeomorphisms relative to which they are generalized Lie groups or topological groups. Among such topologies pairwise incomparable are found as well. Topological perfectness of the diffeomorphism group relative to certain topologies is studied. There are proved theorems about projective limit decompositions of these groups and their compactifications for compact manifolds. Moreover, an existence of one-parameter local subgroups of diffeomorphism groups is investigated.Comment: Some corrections excluding misprints in the article were mad

    Normal families of functions and groups of pseudoconformal diffeomorphisms of quaternion and octonion variables

    Full text link
    This paper is devoted to the specific class of pseudoconformal mappings of quaternion and octonion variables. Normal families of functions are defined and investigated. Four criteria of a family being normal are proven. Then groups of pseudoconformal diffeomorphisms of quaternion and octonion manifolds are investigated. It is proven, that they are finite dimensional Lie groups for compact manifolds. Their examples are given. Many charactersitic features are found in comparison with commutative geometry over R\bf R or C\bf C.Comment: 55 pages, 53 reference

    Normally preordered spaces and utilities

    Full text link
    In applications it is useful to know whether a topological preordered space is normally preordered. It is proved that every kωk_\omega-space equipped with a closed preorder is a normally preordered space. Furthermore, it is proved that second countable regularly preordered spaces are perfectly normally preordered and admit a countable utility representation.Comment: 17 pages, 1 figure. v2 contains a second proof to the main theorem with respect to the published version. The last section of v1 is not present in v2. It will be included in a different wor
    corecore