In this paper we study global dynamics of a general SIRS epidemic model with a ratiodependent incidence rate and its corresponding stochastic differential equation version. For the deterministic model, we show that the disease reproduction number R0 determines whether there is an endemic outbreak or not: the disease free dynamics occurs if R0 ≤ 1 while the unique endemic steady state is globall...

We study an epidemic model with a nonlinear incidence rate which describes the psychological effect of certain serious diseases on the community when the ratio of the number of infectives to that of the susceptibles is getting larger. The model has set up a challenging issue regarding its dynamics near the origin since it is not well defined there. By carrying out a global analysis of the model...

The incidence of motor neurone disease in the Northern Region was studied for the year 1981 by means of hospital activity analysis records and questionnaire. The crude incidence rate was 2.2 per 100,000. This was not significantly different from the rate determined by using death certification. The age standardised incidence ratio for the region was 163 using the 1976 population and deaths from...

functional enuresis is one of the most prevalent cases referred to child psychiatric clinics. the following results were obtained while studying 875 cases of enuresis at esmaili psychiatric center from february 1983 to february 1991, over a period of 8 years. the incidence of functional enuresis is more prevalent among boys as compared to girls, the ratio being 4.5: 1, and incidence of primary ...

BACKGROUND Ankle sprain has been studied in athletic cohorts, but little is known of its epidemiology in the general population. A longitudinal, prospective epidemiological database was used to determine the incidence and demographic risk factors for ankle sprains presenting to emergency departments in the United States. It was our hypothesis that ankle sprain is influenced by sex, race, age, a...

OBJECTIVE To investigate the combined effects on adult mortality of overweight and smoking in late adolescence. DESIGN Record linkage study with Cox proportional hazard ratios adjusted for muscle strength, socioeconomic position, and age. SETTING Swedish military service conscription register, cause of death register, and census data. PARTICIPANTS 45 920 Swedish men (mean age 18.7, SD 0.5...

BACKGROUND ABO blood groups have been shown to be associated with increased risks of venous thromboembolic and arterial disease. However, the reported magnitude of this association is inconsistent and is based on evidence from small-scale studies. METHODS AND RESULTS We used the SCANDAT2 (Scandinavian Donations and Transfusions) database of blood donors linked with other nationwide health dat...