4,204 research outputs found
Effects of glycine supplementation at varying levels of methionine and cystine on the growth performance of broilers fed reduced crude protein diets
Two experiments were conducted to investigate gly addition to reduced crude protein corn-soybean meal (C-SBM) diets with varying levels of TSAA achieved by varying Met and Cys. The experiments were conducted with female Ross 708 broilers in brooder batteries from 0 to 18 d posthatching. Treatments had 6 replicates with 6 broilers/pen. Diets in all experiments were fed without or with gly supplementation to contain 2.32% total gly + Ser. All diets were C-SBM based and formulated to contained 1.27% standardized ileal digestible Lys supplemented with 0.20% Lys (0.394% Lys·SO4) and to meet or exceed the requirement of all nutrients except Met and Cys where appropriate. Experiment 1 consisted of 8 dietary treatments. Three ratios of Met to Cys (60:40, 50:50, and 40:60) were used on a mole for mole basis to achieve 0.063 mol of TSAA/kg of feed and a positive control with Met:Cys of 50:50 at 0.76 TSAA:Lys. glycine supplementation did not affect ADg or ADFI; however, g:F was increased (P = 0.003) with gly supplementation. An increase in Cys and a decrease in Met resulted in a decrease (P = 0.028) in ADg but had no effect on ADFI or g:F. In experiment 2, Met was kept constant at a marginal level of 0.45% and Cys was increased in 0.05% increments from 0.35 to 0.50%. glycine supplementation had no main effect on ADg, ADFI, or g:F; however, gly increased g:F at the lower levels of Cys but not at the higher levels (gly × Cys, P = 0.031). A linear decrease (P = 0.071) was found in ADFI with increasing Cys supplementation. These data indicate that gly increased g:F in female broilers fed suboptimal levels of Met and Cys but not at Cys levels at or above the requirement. This implies that the synthesis of Cys accounts for a portion of the increased g:F observed from gly supplementation in female broilers fed reduced CP C-SBM diets. © 2011 Poultry Science Association Inc
Low-Temperature Excitations of Dilute Lattice Spin Glasses
A new approach to exploring low-temperature excitations in finite-dimensional
lattice spin glasses is proposed. By focusing on bond-diluted lattices just
above the percolation threshold, large system sizes can be obtained which
lead to enhanced scaling regimes and more accurate exponents. Furthermore, this
method in principle remains practical for any dimension, yielding exponents
that so far have been elusive. This approach is demonstrated by determining the
stiffness exponent for dimensions , (the upper critical dimension),
and . Key is the application of an exact reduction algorithm, which
eliminates a large fraction of spins, so that the reduced lattices never exceed
variables for sizes as large as L=30 in , L=9 in , or L=8
in . Finite size scaling analysis gives for ,
significantly improving on previous work. The results for and ,
and , are entirely new and are compared with
mean-field predictions made for d>=6.Comment: 7 pages, LaTex, 7 ps-figures included, added result for stiffness in
d=7, as to appear in Europhysics Letters (see
http://www.physics.emory.edu/faculty/boettcher/ for related information
Monte Carlo Study of the Anisotropic Heisenberg Antiferromagnet on the Triangular Lattice
We report a Monte Carlo study of the classical antiferromagnetic Heisenberg
model with easy axis anisotropy on the triangular lattice. Both the free energy
cost for long wavelength spin waves as well as for the formation of free
vortices are obtained from the spin stiffness and vorticity modulus
respectively. Evidence for two distinct Kosterlitz-Thouless types of
defect-mediated phase transitions at finite temperatures is presented.Comment: 8 pages, 10 figure
Z_2-vortex ordering of the triangular-lattice Heisenberg antiferromagnet
Ordering of the classical Heisenberg antiferromagnet on the triangular
lattice is studied by means of a mean-field calculation, a scaling argument and
a Monte Carlo simulation, with special attention to its vortex degree of
freedom. The model exhibits a thermodynamic transition driven by the Z_2-vortex
binding-unbinding, at which various thermodynamic quantities exhibit an
essential singularity. The low-temperature state is a "spin-gel" state with a
long but finite spin correlation length where the ergodicity is broken
topologically. Implications to recent experiments on triangular-lattice
Heisenberg antiferromagnets are discussed
The Comparative Effects of 0.12% Chlorhexidine and Herbal Oral Rinse on Dental Plaque-Induced Gingivitis
PURPOSE: The purpose of this study was to determine the effects of two oral rinses-one 0.12% chlorhexidine rinse (CHX) and one herbal rinse (HBR)-on gingival health status over time.
METHODS: Sixty-three participants were randomly assigned to one of three treatment groups: CHX, HBR, or placebo. For three months, participants rinsed twice daily (morning and evening) with (1/2) ounce of allocated rinse after brushing and flossing. Individuals were given the same type of soft bristle toothbrush and whitening toothpaste. No attempt was made to modify participants\u27 routine oral care, except they were advised to refrain from use of any other oral rinse for the duration of the study. Data were collected at baseline (B), month one (1), two (2), and three (3) utilizing the Gingival Index (GI), Plaque Index (PI), and bleeding on probing (BOP). A full mouth periodontal probing was performed at baseline and at the completion of the study. A soft tissue oral assessment was completed at each visit. CHX, HBR, and placebo data were compared between three time intervals, B-1, B-2, and B-3. Statistical analysis was conducted by means of multiple regression using generalized linear models. Paired comparison tests--ANOVA followed by a post hoc Tukey test--were used to confirm results.
RESULTS: CHX was the only oral rinse to demonstrate a statistically significant effect on the reduction of mean GI, BOP, and PI scores when compared to placebo. CHX demonstrated a 31% reduction in the proportion of GI scores between B-2 and a 29% reduction between B-3 (p=.003 and p=.012, respectively). CHX demonstrated a 19% reduction of BOP sites between B-1, 32% reduction between B-2, and 29% reduction between B-3 (p=.028, p=.000, and p=.005, respectively). CHX demonstrated a 20% reduction in PI scores between B-1, and a 28% reduction between B-2 (p=.005 and p=.032, respectively). The effects of HBR on reducing mean GI, BOP, and PI scores were not statistically greater than placebo at any time during the study
Nonequilibrium relaxation study of the anisotropic antiferromagnetic Heisenberg model on the triangular lattice
Effect of exchange anisotropy on the relaxation time of spin and vector
chirality is studied for the antiferromagnetic classical Heisenberg model on
the triangular lattice by using the nonequilibrium relaxation Monte Carlo
method. We identify the Berezinskii-Kosterlitz-Thouless (BKT) transition and
the chiral transition in a wide range of the anisotropy, even for very small
anisotropy of 0.01%. As the anisotropy decreases, both the critical
temperatures steeply decrease, while the BKT critical region becomes
divergently wide. We elucidate a sharp "V shape" of the phase diagram around
the isotropic Heisenberg point, which suggests that the isotropic case is
exceptionally singular and the associated Z vortex transition will be isolated
from the BKT and chiral transitions. We discuss the relevance of our results to
peculiar behavior of the spin relaxation time observed experimentally in
triangular antiferromagnets.Comment: 5 pages, 4 figures, accepted for publication in J. Phys. Soc. Jp
Off Equilibrium Study of the Fluctuation-Dissipation Relation in the Easy-Axis Heisenberg Antiferromagnet on the Kagome Lattice
Violation of the fluctuation-dissipation theorem (FDT) in a frustrated
Heisenberg model on the Kagome lattice is investigated using Monte Carlo
simulations. The model exhibits glassy behaviour at low temperatures
accompanied by very slow dynamics. Both the spin-spin autocorrelation function
and the response to an external magnetic field are studied. Clear evidence of a
constant value of the fluctuation dissipation ratio and long range memory
effects are observed for the first time in this model. The breakdown of the FDT
in the glassy phase follows the predictions of the mean field theory for spin
glasses with one-step replica symmetry breaking.Comment: 4 pages, 4 figure
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