Numerical revision of the universal amplitude ratios for the two-dimensional 4-state Potts model

Monte Carlo (MC) simulations and series expansion (SE) data for the energy, specific heat, magnetization and susceptibility of the ferromagnetic 4-state Potts model on the square lattice are analyzed in a vicinity of the critical point in order to estimate universal combinations of critical amplitudes. The quality of the fits is improved using predictions of the renormalization group (RG) approach and of conformal invariance, and restricting the data within an appropriate temperature window. The RG predictions on the cancelation of the logarithmic corrections in the universal amplitude ratios are tested. A direct calculation of the effective ratio of the energy amplitudes using duality relations explicitly demonstrates this cancelation of logarithms, thus supporting the predictions of RG. We emphasize the role of corrections of background terms on the determination of the amplitudes. The ratios of the critical amplitudes of the susceptibilities obtained in our analysis differ significantly from those predicted theoretically and supported by earlier SE and MC analysis. This disagreement might signal that the two-kink approximation used in the analytical estimates is not sufficient to describe with fair accuracy the amplitudes of the 4-state model.Comment: 32 pages, 9 figures, 11 table

The RANLUX generator: resonances in a random walk test

Using a recently proposed directed random walk test, we systematically investigate the popular random number generator RANLUX developed by Luescher and implemented by James. We confirm the good quality of this generator with the recommended luxury level. At a smaller luxury level (for instance equal to 1) resonances are observed in the random walk test. We also find that the lagged Fibonacci and Subtract-with-Carry recipes exhibit similar failures in the random walk test. A revised analysis of the corresponding dynamical systems leads to the observation of resonances in the eigenvalues of Jacobi matrix.Comment: 18 pages with 14 figures, Essential addings in the Abstract onl

The COP9 SIGNALOSOME is required for postembryonic meristem maintenance in Arabidopsis thaliana

Cullin-RING E3 ligases (CRLs) regulate different aspects of plant development, and are activated by modification of their cullin subunit with the ubiquitin-like protein NEDD8 (NEural precursor cell expressed Developmentally Down-regulated 8) (neddylation) and deactivated by NEDD8 removal (deneddylation). The CONSTITUTIVELY PHOTOMORPHOGENIC9 (COP9) signalosome (CSN) acts as a molecular switch of CRLs activity by reverting their neddylation status, but its contribution to embryonic and early seedling development remains poorly characterized. Here, we analyzed the phenotypic defects of csn mutants and monitored the cullin deneddylation/neddylation ratio during embryonic and early seedling development. We show that while csn mutants can complete embryogenesis (albeit at a slower pace than wild type) and are able to germinate (albeit at a reduced rate), they progressively loose meristem activity upon germination, until they become unable to sustain growth. We also show that the majority of cullin proteins is progressively neddylated during the late stages of seed maturation and becomes deneddylated upon seed germination. This developmentally regulated shift in the cullin neddylation status is absent in csn mutants. We conclude that the CSN and its cullin deneddylation activity are required to sustain postembryonic meristem function in Arabidopsis

Can street-level bureaucrats be nudged to increase effectiveness in welfare policy?

This article investigates whether street-level bureaucrats can be incentivised to process information in ways that lead to more effective implementation decisions. It draws on the literatures on behavioural public policy (BPP) and street-level bureaucracy to analyse how civil servants implement disability insurance policy in Switzerland. We conducted a field experiment to assess whether a thought-provoking nudge improves the decisional effectiveness of street-level bureaucrats (SLBs). SLBs were assigned to either a ‘business-as-usual’ control condition, or to an experimental condition, where they were called to pay attention to vulnerability processes along the beneficiaries’ life course when making decisions. While we did not find that the thought-provoking nudge directly improved effectiveness, we found that it increased beneficiaries’ humanisation. In particular, there was some evidence for indirect positive effects of the thought-provoking nudge on effectiveness via humanisation. These findings encourage BPP researchers to consider additional dimensions such as humanisation to nudge SLBs into processing information in better ways

3D Evaluation of Upper Airway Morphological Changes in Growing Patients with Class II Malocclusion Using Sander Bite Jumping Appliance

Class II malocclusion due to mandibular retrognathia is associated with a posterior positioning of the tongue and the hyoid bone, reducing the oropharyngeal volume. This could be a contributing factor to the development of respiratory and cardiovascular problems. This study evaluates the oropharyngeal volume variation in 13 patients with class II malocclusion undergoing functional orthopedic treatment with Sander Bite Jumping Appliance (SBJ). CBCT scans were performed before treatment (T0) and approximately after 12.5 months (T1): the retropalatal volume and retroglossal volume were quantified in mm(3) using a segmentation software. At T1, the retropalatal volume increased in 2523 +/- 2088 mm(3), and the retroglossal volume increased in 2258 +/- 1717 mm(3). Both values were statistically significant (p < 0.05). This widening of the airways may allow prevention and treatment of sleep-disordered breathing, including obstructive sleep apnea syndrome