22 research outputs found
A practical solution to the sign problem in a matrix model for dynamical compactification
The matrix model formulation of superstring theory offers the possibility to
understand the appearance of 4d space-time from 10d as a consequence of
spontaneous breaking of the SO(10) symmetry. Monte Carlo studies of this issue
is technically difficult due to the so-called sign problem. We present a
practical solution to this problem generalizing the factorization method
proposed originally by two of the authors (K.N.A. and J.N.). Explicit Monte
Carlo calculations and large-N extrapolations are performed in a simpler matrix
model with similar properties, and reproduce quantitative results obtained
previously by the Gaussian expansion method. Our results also confirm that the
spontaneous symmetry breaking indeed occurs due to the phase of the fermion
determinant, which vanishes for collapsed configurations. We clarify various
generic features of this approach, which would be useful in applying it to
other statistical systems with the sign problem.Comment: 44 pages, 64 figures, v2: some minor typos correcte
Phytogenic Effects on Layer Production Performance and Cytoprotective Response in the Duodenum
The aim of this study was to evaluate the effects of a phytogenic premix (PP) on the production performance and critical genes relevant to the detoxification (i.e., aryl hydrocarbon receptor pathway) and antioxidant (i.e., nuclear factor erythroid 2-related factor 2 pathway) response in the duodenum of laying hens. The PP was based on bioactive substances derived from ginger, lemon balm, oregano, and thyme (Anco FIT-Poultry). A total of 385 20 week old Hy-Line Brown layers were assigned to five dietary treatments with seven replicates of 11 hens each for a 12-week feeding trial. The experimental treatments included a corn–soybean meal basal diet with no PP (CON) or supplemented with PP at 500 (P500), 750 (P750), 1000 (P1000), and 1500 mg/kg diet (P1500). The overall (1–12 weeks) laying rate (p p = 0.008) were significantly increased in the P1000 group compared with the CON. At the duodenum, increasing dietary PP inclusion levels beneficially affected (p ≤ 0.05) the expression of the majority of the AhR and Nrf2 pathway genes studied. In conclusion, according to the gene expression analysis, PP inclusion resulted in a reduced requirement for detoxification and an increased antioxidant capacity, with most of the effects seen at the PP inclusion range of 750 to 1000 mg/kg diet
Supplemental material for Kynos Through Time: Decorated Pottery Sherds from Eleven Strata of a Homeric Greek Site
<p>Supplemental material for Kynos Through Time: Decorated Pottery Sherds from Eleven Strata of a Homeric Greek Site by Agoritsa Tsiachri, Georgios P. Mastrotheodoros, Harrisis Zoubos, Dimitrios F. Anagnostopoulos and Konstantinos G. Beltsios in Applied Spectroscopy</p
Multiobjective evolutionary algorithms for complex portfolio optimization problems
Multiobjective optimization, NSGA-II, PESA, Portfolio selection, SPEA2,