122 research outputs found

    Boundary and Interface CFTs from the Conformal Bootstrap

    Get PDF
    40 pages, many figures v2: new results on 3d O(N) bulk spectrum added, one appendix eliminated, typos corrected, references updated. v3: two references to high precision Monte Carlo data added; they nicely agree with our bootstrap calculations. Matches published version. v4: results for the extraordinary transition for N=2,3 removed: see added noteWe explore some consequences of the crossing symmetry for defect conformal field theories, focusing on codimension one defects like flat boundaries or interfaces. We study surface transitions of the 3d Ising and other O(N) models through numerical solutions to the crossing equations with the method of determinants. In the extraordinary transition, where the low-lying spectrum of the surface operators is known, we use the bootstrap equations to obtain information on the bulk spectrum of the theory. In the ordinary transition the knowledge of the low-lying bulk spectrum allows to calculate the scale dimension of the relevant surface operator, which compares well with known results of two-loop calculations in 3d. Estimates of various OPE coefficients are also obtained. We also analyze in 4-epsilon dimensions the renormalization group interface between the O(N) model and the free theory and check numerically the results in 3d

    Gluten contamination of canned and dry grain-free commercial pet foods determined by HPLC-HRMS

    Get PDF
    The aim was to determine the absence of gluten in pet food samples marked as ‘grain-free’ and ‘gluten-free’ diets, to assess the reliability of manufacturer labelling of such products. A total of 15 diets labelled as grain- or gluten-free and 2 commercial diets containing wheat were sampled. An analytical procedure using high-pressure liquid chromatography coupled with mass spectrometry with high power of resolution was developed and applied to determine specific markers of wheat gluten. The results are expressed as mg of wheat flour type ‘00’ present in 1 g of feed. The quantification limit (LOQ) obtained in the flour for ion m/z 894.5043, z = 2, is 4 mg of flour per gram. In 14 out of the 15 samples from a grain- or gluten-free diet the quantifier ion signal was < LOQ, while in 1 out of the 15 samples 10 mg of flour/g feed were measured.Highlights Adverse reaction to gluten in dogs have been documented in certain breeds Gluten is tricky to detect and measure in pet food Contamination of gluten in pet food samples marked as ‘grain-free’ and ‘gluten-free’ diets An analytical procedure was developed using HPLC coupled with HRM

    Productive and qualitative traits of amaranthus cruentus l.: An unconventional healthy ingredient in animal feed

    Get PDF
    Agronomic traits, oil content, fatty acid composition, antioxidant activity, and total phenolic content were studied on eight A. cruentus accessions cultivated in Southern Italy. A one-way ANOVA model was performed to compare accessions and the Principal Components Analysis was applied to identify patterns in our dataset and highlight similarities and differences. A. cruentus showed valuable seed yield (0.27 kg/m2, on average) comparable to the main tradition cereals used for animal feeding. Seed-oil composition showed significant differences among the accessions. Data showed a higher lipid content than most cereal grains (from 5.6 to 7.3%). Approximately 60% of fatty acids were unsaturated; linoleic fatty acid ranged from 19 to 34%, oleic acid from 29 to 36%, and alfa-linolenic fatty acid from 0.3 to 0.5%, respectively. The saturated/unsaturated fatty acid ratio ranged from 0.5 to 0.8, the hypocholesterolemic:hypercholesterolaemic ratio from 1.7 to 2.7, the Atherogenic Index from 0.38 to 0.66, the Thrombogenic Index from 0.85 to 1.48, the total phenolic content from 0.14 to 0.36 mg/g seeds, and the antioxidant activity (DPPH&bull;) from 0.30 to 0.50. The studied seed-oil composition evidenced A. cruentus as a healthy ingredient for animal feed and consequently, as a possible substitute for traditional cereals. Accessions from Mexico and Arizona emerged for their high qualitative traits

    Management of feline hyperthyroidism and the need to prevent oxidative stress: What can we learn from human research?

    Get PDF
    Feline hyperthyroidism is a clinical syndrome related to an excessive production of thyroid hormones, and it is considered as a spontaneous animal model for human thyrotoxicosis. Many shared features between the feline and the human disease have been identified so far, including pathogenesis, clinical signs, and treatment options. Although methimazole is considered the first-choice drug in both species, several side effects have been described. Furthermore, methimazole could interfere with the oxidative status, already perturbated by the disease. It has been reported in humans that dietary management, mainly through antioxidant supplementation, could mitigate this oxidative burden. The purpose of the review is to describe current therapeutic options in the course of feline hyperthyroidism and to summarize the state of the art relationship between dietary antioxidants administration and the reduction of methimazole side-effects in humans to support the use of this approach also in cats

    The Lorentz-invariant boundary action of the confining string and its universal contribution to the inter-quark potential

    Full text link
    We study the boundary contribution to the low energy effective action of the open string describing the confining flux tube in gauge theories. The form of the boundary terms is strongly constrained by the requirement of Lorentz symmetry, which is spontaneously broken by the formation of a long confining flux tube in the vacuum. Writing the boundary action as an expansion in the derivatives of the Nambu-Goldstone modes describing the transverse fluctuations of the string, we single out and put in a closed form the first few Lorentz invariant boundary terms. We also evaluate the leading deviation from the Nambu-Goto string produced by the boundary action on the vacuum expectation value of the Wilson loop and we test this prediction in the 3d Ising gauge model. Our simulation attains a level of precision which is sufficient to test the contribution of this term.Comment: 17 pages, 5 figures, LateX 2e. V2: Final version published on JHEP. Fixed typos in eq.s 2.2, 2.3, 3.7, 3.8, A.4. Extended explanation of the procedures used in sec 2 to determine the possible boundary terms up to field redefinitions and of the procedure used in sec 4 to take the continuum limit. V3: typos corrected in eq.s (4.3) (4.5) and (4.6), acknowledgements adde
    • …
    corecore