Linear systematic sampling design is very simple and operationally convenient in practice, but, when the population size is not a multiple of the sample size, results in a variable sample size and in this case sample mean as an estimator of the population mean is not unbiased. To overcome these difficulties and in some cases to increase the efficiency, a number of modifications of linear system...

Golestan Province in northeastern Iran has one of the highest rates of esophageal squamous cell cancer in the world. This article reviews the studies conducted on esophageal squamous cell cancer in this area and summarizes the data on epidemiologic patterns, incidence trends, and etiology of esophageal squamous cell cancer in this province.

Much attention has been given to sampling design, and the sampling method chosen directly affects the sampling accuracy. The development of spatial sampling theory has lead to the recognition of the importance of taking spatial dependency into account when sampling. This text uses the new Sandwich Spatial Sampling and Inference (SSSI) software as a tool to compare the relative error, coefficien...

Introduction: More than 350 million people are chronic carriers of HBV and many of them develop progressive diseases, including cirrhosis and hepatocellular carcinoma. Many of those infected develop persistent disease and a proportion goes on to develop liver failure and cancer. Researchers showed that double mutations of the x gene at position 1762 and 1764, have been found in chronic hepatiti...

This study was carried out to identify agroeconomic factors on adoption integrated rice-fish farming by farmers. A survey was conducted using a stratified random sampling to collect data from farmers of selected villages in Guilan province, north of Iran. The questionnaire validity and reliability ware also determined to enhance the dependability of the result. Data were collected from 184 resp...

Over the last decade, a few cases of visceral leishmaniasis (VL) have been reported in some districts of the province of Golestan, in north-eastern Iran. The aim of the present study was to investigate the prevalence of Leishmania infantum infection among humans and domestic dogs by using direct agglutination test (DAT) and PCR assays in the eastern zone of the province. Between 2011 and 2012, ...

desertification is one of the major issues threatening human communities. manymethods have been developed for assessment and mapping of desertification hazards. in thisresearch, multi-criteria evaluation method was used to investigate desertification process introuti watershed, golestan province, iran. at the first step, major desertification factors weredetermined by doing field surveys. they ...

background: the incidence rate of esophageal squamouse cell cancer (escc) in eastern part of golestan province in iran is among the highest ones in the world. in order to discover the factors interplay in high rate of escc incidence, several case-control and cross-sectional studies were established in this area.as a cohort study has priority in detecting risk factors of a disease, a 10-year pro...