purpose: to determine the prevalence and determinants of age-related macular degeneration (amd) in a 40-64 year old iranian populationmethods: in a cross-sectional study, 6,311 people were randomly selected from shahroud. for all participants, visual acuity, refraction, slit-lamp examination and fundus photography were conducted under pupil dilation. results: results of this study are based on ...

aim: oral health is one of the most important parts of public health which significantlyaffects on quality of life. the purpose of this study is to assess the socio-economic statues aswell as oral health behaviors among a sample of iranian students studying in elementary level.methods: this was a cross-sectional study which was conducted from april 2012 tonovember 2012. data obtained from a fac...

The use of principal component techniques to estimate approximate factor models with large cross-sectional dimension is now well established. However, recent work by Inklaar, R. J., J. Jacobs and W. Romp (2003) and Boivin, J. and S. Ng (2005) has cast some doubt on the importance of a large cross-sectional dimension for the precision of the estimates. This paper presents some new theory for app...