A sinusoidal grating can be viewed as a series of light and dark bars. Here we measure the contrast discrimination thresholds for light and dark bars individually, and find that the contrast discrimination thresholds for the whole sinusoid can be explained as ideal summation of the light and dark bar thresholds. We propose a model for light bar, dark bar, and sinusoidal contrast discrimination ...

AIM To examine the impact of interval training program on the antioxidant defense capability and lipid profile in men smoking cigarettes or hookah unable or unwilling to quit smoking. METHODS Thirty-five participants performed an interval training (2 : 1 work : rest ratio) 3 times a week for 12 weeks at an intensity of 70% of VO2max. All subjects were subjected to a biochemical test session b...

BACKGROUND Tobacco use is one of the leading causes of preventable deaths in the world. The aim of this study was to determine the prevalence of all common types of tobacco use and identify factors associated with tobacco use among adults in Tehran based on information from the population-based Burden of Obstructive Lung Disease study in Tehran. MATERIALS AND METHODS This study had a stratifi...

BACKGROUND In order to assess the status of drug abuse and likely addiction among university students, a descriptive study was designed. METHODS 1200 subjects among the students of three universities in Zanjan were selected by stratified random sampling and their demographic information and history of substance abuse including hookah, cigarette, codeine, ibuprofen, alcohol, diazepam, tramadol...

OBJECTIVES In the past decade, waterpipe smoking (a.k.a. hookah, shisha, narghile) has become a global phenomenon. In this review, we provide an updated picture of the main epidemiological trends in waterpipe smoking globally. DATA SOURCES Peer-reviewed publications indexed in major biomedical databases between 2004 and 2014. Search keywords included a combination of: waterpipe, hookah, shish...

BACKGROUND Data on spirometrically defined chronic airflow limitation (CAL) are scarce in developing countries. OBJECTIVE To estimate the prevalence of spirometrically defined CAL in Kashmir, North India. METHODS Using Burden of Obstructive Lung Disease survey methods, we administered questionnaires to randomly selected adults aged ⩾40 years. Post-bronchodilator spirometry was performed to ...

Background & objectives: The number of waterpipe cafes has considerably grown in Tehran and other cities of Iran. This increase has occurred due to a wrong belief that the use of hookahs is harmless and relatively safe. So, the aim of current study is to investigate the nicotine concentration in the indoor air of the waterpipe and cigarette cafés as well as the biological concentration of nicot...

IMPORTANCE Exposure to nicotine in electronic cigarettes (e-cigarettes) is becoming increasingly common among adolescents who report never having smoked combustible tobacco. OBJECTIVE To evaluate whether e-cigarette use among 14-year-old adolescents who have never tried combustible tobacco is associated with risk of initiating use of 3 combustible tobacco products (ie, cigarettes, cigars, and...