We discuss theoretical aspects of the self-assembly of triangular tiles, in particular, right triangular tiles and equilateral triangular tiles, and the self-assembly of hexagonal tiles. We show that triangular tile assembly systems and square tile assembly systems cannot be simulated by each other in a non-trivial way. More precisely, there exists a deterministic square (hexagonal) tile assemb...

Materials and methods Design: cross-sectional study. Population: 187 consecutive adolescent girls with idiopathic scoliosis (mean Cobb angle 26°, range 11-73°, age 15.2±2.5; 24% juveniles, 76% adolescent type); 93 school girl controls (age 14.9±1.0). All the subjects answered the Italian validated questionnaire EAT-26 about eating habitude in order to retrieve eating disorders. BMI was calculat...

In this article, by using the method of finite difference time domain (FDTD) and PML boundary conditions, we have studied the photonic band gaps for TE and TM modes in square and triangular lattices consisting of air holes in dielectric medium and compared the results. In addition, the effect of nonlinearity of the photonic crystal background on the photonic band gaps and comparison with the re...

a study was done about non-participation during phase iii of the international study of asthma and allergy in childhood (isaac iii) in valencia to determine whether the non-response rate significantly affected the results obtained in valencia. of the schools selected to participate in isaac iii, 13.3% denied not to, the main reason being they were already participated in a similar study. the is...

background : visual impairment is a very important public health problem. in iran, reports of visual impairment and blindness have been published from the urban population while the prevalence of visual impairment in the rural popu-lation has not been reported. the purpose of this study to determine the prevalence and causes of visual impairment, in a rural population in district of based on ag...

purpose : to study the age and gender specific history of ocular trauma in the population of tehran methods : using a stratified cluster sampling approach, 6,497 residents of tehran were selected. participants were transferred to an eye clinic to have complete eye examinations. during the interview, participants were asked about any history of ocular trauma, and any treatment or hospitalization...

purpose : to determine the prevalence of visual impairment, blindness, and low vision among the elderly population of sari in northern iran methods : random cluster sampling of 1,185 selected individuals over 54 years of age, of whom 79.1% participated. participants underwent eye examinations to test presenting visual acuity (va), best corrected visual acuity (bcva), and refraction. results : b...

conclusions as it was previously reported by the world health organization (who) on hav infection in the country, this study revealed a high prevalence of hav infection in mashhad. background hepatitis a virus (hav) is the most common cause of acute viral hepatitis worldwide, mostly in developing countries. objectives this population-based survey was performed to investigate hav seroprevalence ...