302 research outputs found
The infrared dynamics of Minimal Walking Technicolor
We study the gauge sector of Minimal Walking Technicolor, which is an SU(2)
gauge theory with nf=2 flavors of Wilson fermions in the adjoint
representation. Numerical simulations are performed on lattices Nt x Ns^3, with
Ns ranging from 8 to 16 and Nt=2Ns, at fixed \beta=2.25, and varying the
fermion bare mass m0, so that our numerical results cover the full range of
fermion masses from the quenched region to the chiral limit. We present results
for the string tension and the glueball spectrum. A comparison of mesonic and
gluonic observables leads to the conclusion that the infrared dynamics is given
by an SU(2) pure Yang-Mills theory with a typical energy scale for the spectrum
sliding to zero with the fermion mass. The typical mesonic mass scale is
proportional to, and much larger than this gluonic scale. Our findings are
compatible with a scenario in which the massless theory is conformal in the
infrared. An analysis of the scaling of the string tension with the fermion
mass towards the massless limit allows us to extract the chiral condensate
anomalous dimension \gamma*, which is found to be \gamma*=0.22+-0.06.Comment: 29 pages, 16 figure
Finite volume effects in SU(2) with two adjoint fermions
Many evidences from lattice simulations support the idea that SU(2) with two
Dirac flavors in the adjoint representation (also called Minimal Walking
Technicolor) is IR conformal. A possible way to see this is through the
behavior of the spectrum of the mass-deformed theory. When fermions are
massive, a mass-gap is generated and the theory is confined. IR-conformality is
recovered in the chiral limit: masses of particles vanish in the chiral limit,
while their ratios stay finite. In order to trust this analysis one has to
relay on the infinite volume extrapolation. We will discuss the finite volume
effects on the mesonic spectrum, investigated by varying the size of the
lattice and by changing the boundary conditions for the fields.Comment: Proceedings of Lattice 2011, 7 pages, 4 figure
The meson spectrum in large-N QCD
We present lattice results on the meson spectrum and decay constants in large-N QCD. The results are obtained in the quenched approximation for N = 2,3,4,5,6,7 and 17 and extrapolated to N = ∞. Xth Quark Confinement and the Hadron Spectrum
Topological susceptibility of SU(N) gauge theories at finite temperature
We investigate the large-N behavior of the topological susceptibility in
four-dimensional SU(N) gauge theories at finite temperature, and in particular
across the finite-temperature transition at Tc. For this purpose, we consider
the lattice formulation of the SU(N) gauge theories and perform Monte Carlo
simulations for N=4,6. The results indicate that the topological susceptibility
has a nonvanishing large-N limit for T<Tc, as at T=0, and that the topological
properties remain substantially unchanged in the low-temperature phase. On the
other hand, above the deconfinement phase transition, the topological
susceptibility shows a large suppression. The comparison between the data for
N=4 and N=6 hints at a vanishing large-N limit for T>Tc.Comment: 9 pages, 2 figs, a few discussions added, JHEP in pres
Center vortices and k-strings
The vortex contribution to the -string tensions is computed for SU() gauge theories. We deduce the surface densities needed to reproduce the sine scaling and the Casimir scaling formulae, recently obtained from numerical simulations on the lattice. We find that such densities need to grow linearly in , which in turn suggests that the vortex scenario can hardly reproduce the physics of confinement at large
Role of chitosan against grapevine downy mildew
The study of environmentally friendly active principles against downy mildew represents one of the main challenges in viticulture. In this context, the aim of the present trial was to investigate the efficacy of chitosan as a resistance elicitor against downy mildew and to study the metabolites involved in the interaction plant-chitosan-pathogen by a metabolomics approach. The experiments were carried out on potted vines of Merlot R18 grafted on SO4 rootstock, Guyot trained, during 2022. Leaf disks pre-treated with chitosan were infected by Plasmopara viticola sporangia in 3 phenological phases and the development of infection was recorded. The most significant findings were: 1) Chitosan resulted as an effective elicitor of defense mechanism against Plasmopara viticola. 2) The elicitor activity of chitosan was explained mainly through the induction of some secondary metabolites (terpenes and resveratrol), fatty acids (involved in the biosynthesis of sterols), and hormones (brassinosteroids and abscisic acid). 3) The best efficacy corresponded to the application of chitosan 48 hours before the infection. The timing of the treatment was, therefore, one of the key factors for the success of chitosan treatment
Effect of Moringa oleifera L. Leaf Powder Addition on the Phenolic Bioaccessibility and on In Vitro Starch Digestibility of Durum Wheat Fresh Pasta
Fresh pasta was formulated by replacing wheat semolina with 0, 5, 10, and 15 g/100 g (w/w) of Moringa oleifera L. leaf powder (MOLP). The samples (i.e., M0, M5, M10, and M15 as a function of the substitution level) were cooked by boiling. The changes in the phenolic bioaccessibility and the in vitro starch digestibility were considered. On the cooked-to-optimum samples, by means of ultra-high-performance liquid chromatography-quadrupole time-of-flight (UHPLC-QTOF) mass spectrometry, 152 polyphenols were putatively annotated with the greatest content recorded for M15 pasta, being 2.19 mg/g dry matter (p < 0.05). Multivariate statistics showed that stigmastanol ferulate (VIP score = 1.22) followed by isomeric forms of kaempferol (VIP scores = 1.19) and other phenolic acids (i.e., schottenol/sitosterol ferulate and 24-methylcholestanol ferulate) were the most affected compounds through the in vitro static digestion process. The inclusion of different levels of MOLP in the recipe increased the slowly digestible starch fractions and decreased the rapidly digestible starch fractions and the starch hydrolysis index of the cooked-to-optimum samples. The present results showed that MOLP could be considered a promising ingredient in fresh pasta formulation
Distilled grape pomace as a functional ingredient in vegan muffins: effect on physicochemical, nutritional, rheological and sensory aspects
Wheat-based vegan muffins were formulated with increasing levels (0, 5 and 10 g per 100 g substitutes to flour) of dried grape pomace powder obtained after distillation (DGPP). The DGPP-muffins showed a greater (P < 0.05) total dietary fibre and a lower (P < 0.05) total starch content to the control. The inclusion of DGPP influenced (P < 0.05) both the batter's rheological properties and the baked muffins' technological characteristics, including the baking loss, the volume, the firmness, the spread ratio and the colour. The in vitro antioxidant activity and the phenolic content increased (P < 0.05) following DGPP inclusion. The untargeted phenolic profiling by UHPLC-HRMS revealed an (P < 0.05) increase of several phenolic classes (i.e. free and bound fractions) following the inclusion of DGPP in the recipe. Flavonoids, mainly anthocyanins, were the most abundant compounds. A quantitative descriptive sensory analysis detected the DGPP-vegan muffins showed good sensory acceptability. The vegan muffin with 5 g per 100 g of DGPP obtained the highest overall acceptability score by the panellists
Administration of Aloe arborescens homogenate to cattle: interaction with rumen fermentation and gut absorption of aloin
Aloe has long been used as a traditional medicine for its numerous beneficial properties, which are mainly ascribed to β-polysaccharides and phenolic compounds including anthraquinones, anthrones and chromones. However, few studies on large animals are currently available. The effect of whole leaf Aloe arborescens homogenate on the in vitro rumen fermentative processes was tested using alfalfa hay and barley meal as substrates. The Aloe homogeneate was added at three different concentrations (0.4, 2.0 and 10.0 g L−1 of fermentation liquid). The same homogenate was dosed (200 g) orally and through the rumen cannula to three rumen cannulated heifers and orally to six lactating dairy cows to measure the rumen degradation of aloin and the transfer of aloin from the gut into the blood, respectively. The Aloe homogenate did not affect in vitro rumen fermentations and feed digestibility. The administration of Aloe homogenate did not negatively affect animal feed intake and health neither on the cannulated heifers nor on the dairy cows. Aloin underwent a rapid degradation in the rumen milieu, and became undetectable 2 h after oral dosage. However, when Aloe homogenate was administered to dairy cows, aloin appeared in blood as early as 2 h after administration, reached a maximum after 4 h (6.2 ± 5.8 μg L−1) and progressively decreased thereafter. These results suggest that Aloe compounds can be absorbed into the blood and encourage the study of Aloe as a potential nutraceutical in ruminants. Further studies should determine the most effective in vivo dosage
Effect of Moringa oleifera L. Leaf Powder Addition on the Phenolic Bioaccessibility and on In Vitro Starch Digestibility of Durum Wheat Fresh Pasta
Fresh pasta was formulated by replacing wheat semolina with 0, 5, 10, and 15 g/100 g (w/w) of Moringa oleifera L. leaf powder (MOLP). The samples (i.e., M0, M5, M10, and M15 as a function of the substitution level) were cooked by boiling. The changes in the phenolic bioaccessibility and the in vitro starch digestibility were considered. On the cooked-to-optimum samples, by means of ultra-high-performance liquid chromatography-quadrupole time-of-flight (UHPLC-QTOF) mass spectrometry, 152 polyphenols were putatively annotated with the greatest content recorded for M15 pasta, being 2.19 mg/g dry matter (p < 0.05). Multivariate statistics showed that stigmastanol ferulate (VIP score = 1.22) followed by isomeric forms of kaempferol (VIP scores = 1.19) and other phenolic acids (i.e., schottenol/sitosterol ferulate and 24-methylcholestanol ferulate) were the most affected compounds through the in vitro static digestion process. The inclusion of different levels of MOLP in the recipe increased the slowly digestible starch fractions and decreased the rapidly digestible starch fractions and the starch hydrolysis index of the cooked-to-optimum samples. The present results showed that MOLP could be considered a promising ingredient in fresh pasta formulation
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