Search results for "ASYM"

$PT$-symmetric graphene under a magnetic field

2016

We propose a $PT$-symmetrically deformed version of the graphene tight-binding model under a magnetic field. We analyze the structure of the spectra and the eigenvectors of the Hamiltonians around the $K$ and $K'$ points, both in the $PT$-symmetric and $PT$-broken regions. In particular we show that the presence of the deformation parameter $V$ produces several interesting consequences, including the asymmetry of the zero-energy states of the Hamiltonians and the breakdown of the completeness of the eigenvector sets. We also discuss the biorthogonality of the eigenvectors, which {turns out to be} different in the $PT$-symmetric and $PT$-broken regions.

Single π0 production off neutrons bound in deuteron with linearly polarized photons

2021

The quasifree γ→d→π0n(p) photon beam asymmetry, Σ, has been measured at photon energies, Eγ, from 390 to 610 MeV, corresponding to center of mass energy from 1.271 to 1.424 GeV, for the first time. The data were collected in the A2 hall of the MAMI electron beam facility with the Crystal Ball and TAPS calorimeters covering pion center-of-mass angles from 49∘ to 148∘. In this kinematic region, polarization observables are sensitive to contributions from the Δ(1232) and N(1440) resonances. The extracted values of Σ have been compared to predictions based on partial-wave analyses (PWAs) of the existing pion photoproduction database. Our comparison includes the SAID, MAID and Bonn–Gatchina anal…

Measurement of the spin-dependent structure function g1(x) of the deuteron

1993

We report on the first measurement of the spin-dependent structure function g1d of the deuteron in the deep inelastic scattering of polarised muons off polarised deuterons, in the kinematical range 0.006<x<0.6, 1 GeV2<Q2<30 GeV2. The first moment, Γ1d=sh{phonetic}01 g1d dx=0.023±0.020 (stat.) ± 0.015 (syst.), is smaller than the prediction of the Ellis-Jaffe sum rules. Using earlier measurements of g1p, we infer the first moment of the spin-dependent neutron structure function g1n. The difference Γ1p-Γ1n=0.20 ±0.05 (stat.) ± 0.04 (syst.) agrees with the prediction of the Bjorken sum rule, Γ1p-Γ1n=0.191 ±0.002.

Distraction osteogenesis in Goldenhar Syndrome: Case report and 8-year follow-up

2007

Goldenhar syndrome is a well-known condition featuring the following triad of anomalies: ocular abnormalities, microtia and vertebral anomalies. This syndrome involves structures arising from the first and second branchial arches. Craniofacial anomalies, including mandibular, zygomatic and/or maxillary hypoplasias are found in 50% of patients with Goldenhar syndrome. Patients with this syndrome may present unilateral or bilateral underdevelopment of the mandible. Several treatments for the correction of the dento-facial deformity have been described, among them distraction osteogenesis is one that shows promising results. Distraction osteogenesis is the process of bone formation that occurs…

La politique de dividende permet-elle de discipliner les dirigeants?

2010

Depuis près de 25 ans, la théorie de l’agence (Easterbrook, 1984 ; Jensen, 1986) postule que les actionnaires demandent des dividendes pour discipliner les dirigeants. Une analyse approfondie de la littérature montre cependant que la politique de dividende ne constitue pas un mécanisme efficace de gouvernance, pour au moins trois raisons : les attentes des divers groupes d’actionnaires sont variées en matière de versement de dividendes ; les entreprises concernées présentent des caractéristiques spécifiques ; la gouvernance des entreprises est de « faible » qualité du point de vue des actionnaires minoritaires.

A cardiac fibroma in a 7-year-old asymptomatic girl admitted for ECG anomalies

2012

On hidden heterogeneity in directional asymmetry – can systematic bias be avoided?

2006

8 pages; International audience; Directional asymmetry (DA) biases the analysis of fluctuating asymmetry (FA) mainly because among-individual differences in the predisposition for DA are difficult to detect. However, we argue that systematic bias mainly results from predictable associations between signed right-left asymmetry and other factors, i.e. from systematic variation in DA. We here demonstrate methods to test and correct for this, by analysing bilateral asymmetry in size and shape of an irregular sea urchin. Notably, in this model system, DA depended significantly on body length and geographic origin, although mean signed asymmetry (mean DA) was not significant in the sample as a wh…

Models of the population playing the Rock-Paper-Scissors game

2018

We consider discrete dynamical systems coming from the models of evolution of populations playing rock - paper - scissors game . Asymptotic behaviour of trajectories of these systems is described, occurrence of the Neimark-Sacker bifurcation and nonexistence of time averages are proved.

Accessory submaxillary gland : two new case reports and a literature review

2020

Background The accessory submaxillary gland is a very uncommon anatomical variant, and incidence in the general population has not yet been quantified. The presence of pathology in these glands is rarer still, thus often going unnoticed. Material and methods We describe two accessory submaxillary gland cases, one asymptomatic and the other with chronic sialadenitis in the main and accessory gland caused by sialolithiasis. Although our diagnosis was by computerized tomography, magnetic resonance sialography is helpful to understand and describe this entity with greater precision. Results The first case report is an incidental finding and no intervention was required. However, case report num…

Frequency of mesiodens in the pediatric population in North India: A radiographic study

2013

Objectives: Mesiodens are the most common supernumerary teeth, occurring in 0.15% to 2.2% of the population. The aim of the present study was to analyze the frequency and radiological features of mesiodens in the pediatric population. Material and methods: The study was based on the radiographic evaluation of 4133 pediatric patients of the age range of 4-15 years, attending the Department of Oral Medicine and Radiology during the time period between September 2008 to December 2012. In addition to the presence of a supernumerary tooth between the 2 central incisors, data regarding the number, position, shape and associated complications were also recorded. Results: The prevalence of mesioden…