Introduction: Exposure to flour dust is an important risk factor in occurrence of allergic airway disorders among mill workers. The purpose of this study was to determine the prevalence of respiratory symptoms and its relation with exposure to respirable dust. Materials and Methods: In this study, all of 35 workers who worked in the flour producing section of three factories were chosen as ca...

This paper characterizes the attractor structure of synchronous and asynchronous Boolean networks induced by bithreshold functions. Bi-threshold functions are generalizations of standard threshold functions and have separate threshold values for the transitions 0 → 1 (up-threshold) and 1 → 0 (down-threshold). We show that synchronous bi-threshold systems may, just like standard threshold system...

Background: Hazardous chemical agents in the welding operation are a mixture of metal fumes and toxic gases, the inhalation of which causes adverse health effects among welders. The emission of gases in the workplace is a logical cause for concern regarding the potential development of respiratory disease. The aim of the present study was to determine the concentration values of gases discharge...

We obtain the location of the Hopf bifurcation threshold for a modified van der Pol oscillator, parametrically driven by a stochastic source and including delayed feedback in both position and velocity. We introduce a multiple scale expansion near threshold, and we solve the resulting Fokker-Planck equation associated with the evolution at the slowest time scale. The analytical results are comp...

A simple, non-equilibrium model is used to evaluate the likely DC performance of carbon nanotube field-effect transistors. It is shown that, by appropriate work function engineering of the source, drain and gate contacts to the device, the following desirable properties should be realizable: a sub-threshold slope close to the thermionic limit; a conductance close to the interfacial limit; an ON...

This paper develops an asymptotic theory for time series discrete choice models with explanatory variables generated as integrated processes and with multiple choices and threshold parameters determining the choices. The theory extends recent work by Park and Phillips (2000) on binary choice models. As in this earlier work, the maximum likelihood (ML) estimator is consistent and has a limit the...

2014 A storage ring free-electron laser oscillator has been operated above threshold at a visible wavelength 03BB ~ 6 500 Å. This laser was obtained with electrons of 166 MeV circulating in the storage ring ACO. The light emitted by the electrons passing through an optical klystron (a modified version of an undulator) is stored in a high-Q optical cavity. First some below laser threshold phenom...

First data on coherent threshold π electroproduction from the deuteron taken by the A1 Collaboration at the Mainz Microtron MAMI are presented. At a four-momentum transfer of q = −0.1GeV/c the full solid angle was covered up to a centerof-mass energy of 4 MeV above threshold. By means of a Rosenbluth separation the longitudinal threshold s wave multipole and an upper limit for the transverse th...

First data on coherent threshold π electroproduction from the deuteron taken by the A1 Collaboration at the Mainz Microtron MAMI are presented. At a four-momentum transfer of q = −0.1GeV/c the full solid angle was covered up to a centerof-mass energy of 4 MeV above threshold. By means of a Rosenbluth separation the longitudinal threshold s wave multipole and an upper limit for the transverse th...