the paper examines industrial concentration in iranian food products and beverages industries using firm level data aggregated to the 4-digit isic industry level between 2002 and 2004. based on different concentration indices the average level of concentration has increased slightly for the period of study. the empirical results show that increase in the level of concentration is more likely in...

it is now evident in the literature that the information and communication technology (ict) has a positive and significant impact on the productivity and economic growth. most studies in this area, however, are limited to the developed countries. given different regulations and economic conditions, and also an increasing trend in allocating resources to ict in developing countries, it is import...

This paper shows that imperfect output substitutability explains part of the observed persistent plant-level productivity dispersion. Specifically, as substitutability in a market increases, the market’s productivity distribution exhibits falling dispersion and higher central tendency. The proposed mechanism behind this result is truncation of the distribution from below as increased substituta...

We investigated the role of dopamine in working memory by examining effects of withdrawing dopaminergic medication in patients with Parkinson's disease. Resistance to distraction during a delayed response task was abnormally enhanced in Parkinson's disease patients OFF medication relative to controls. Conversely, performance on a backward digit span test was impaired in these same Parkinson's d...

The PPI is a modified Laspeyres index which estimates a fixed input output price index model. Since the 1978 revision of the PPI, the industry output indexes have been based on the Standard Industrial Classification (SIC). Samples are drawn separately for four digit SIC industries, where each industry is assigned a publication structure prior to sampling. The publication structure partitions th...

The number of phalanges and joints are key features of digit 'identity' and are central to limb functionality and evolutionary adaptation. Prior chick work indicated that digit phalanges and their associated joints arise in a different manner than the more sparsely jointed long bones, and their identity is regulated by differential signalling from adjacent interdigits. Currently, there is no ge...

OBJECTIVES To assess whether contemporary solvent exposures in the vehicle collision repair industry are associated with objectively measured neuropsychological performance in collision repair workers. METHODS The RBANS battery and additional tests were administered to 47 vehicle collision repair and 51 comparison workers randomly selected from a previous questionnaire study. RESULTS Collis...

background: airport workers are continuously exposed to different levels of radiofrequency microwave (rf/mw) radiation emitted by radar equipments. radars are extensively used in military and aviation industries. over the past several years, our lab has focused on the health effects of exposure to different sources of electromagnetic fields such as cellular phones, mobile base stations, mobile ...

introduction: ovako working posture analyzing system (owas) is a method for evaluating postural load during work. the owas method is based on a simple and systematic classification of work postures combined with observations of work tasks. the aim of this study was the assessment of various postures during the work in iron and steel industry, navard ahwas, using owas method. materials and metho...