The ability of Gaussian noise to induce ordered states in dynamical systems is here presented in an overview of the main stochastic mechanisms able to generate spatial patterns. These mechanisms involve: (i) a deterministic local dynamics term, accounting for the local rate of variation of the field variable, (ii) a noise component (additive or multiplicative) accounting for the unavoidable env...

Localized ecological interactions can generate striking large-scale spatial patterns in ecosystems through spatial self-organization. Possible mechanisms include oscillating consumer-resource interactions, localized disturbance-recovery processes and scale-dependent feedback. Despite abundant theoretical literature, studies revealing spatial self-organization in real ecosystems are limited. Rec...

background: several systemic factors and hormones are thought to regulate the fracture healing process. vitamin d has emerged as a compound or hormone that actively participates in the regulation of calcium homeostasis and bone metabolism. objectives: the aim of this study is to determine the serum changes in the level of vitamin d during the acute healing period of tibial and femoral shaft fra...

Background and aims: Congenital anomalies are as the major causes of stillbirths, neonatal death, disability and childhood health problems all over the world. The aim of this study was to determine the incidence and pattern of congenital anomalies in newborn during the first 24 hours of life in Shahid-Madani hospital, Azarshahr, Tabriz, during two periods 2002-2003 and 2...

introduction: ultraviolet (uv) radiation affects human organs such as skin, eyes and immune system, as well as animals and plants. the main natural source of uv radiation is the sun. to study the effects of solar uv radiation there is a need to quantify variations of solar energy received on the earth surface at different intervals. materials and methods: to measure uv radiation a broadband fib...

introdouction: canal length measurement is essential for proper endodontic treatment. any error or miscalculation in working length determination, particularly in curved canals, can result in complications during or after root canal therapy. digital radiography has enabled accurate measurement of curved canal length. in this study, we evaluated the accuracy of calibration of a complementary met...

conclusions according to the results of this study, with increasing load of traffic, there is an increasing need for proper consideration plans to control noise pollution and prevent its effects. results according to the research findings, the equivalent sound pressure levels in all stations were 76.28 ± 3.12 db (mean ± sd). according to sound measurements and the survey questionnaire, noise po...