The formation and growth of leaves around the stem of a plant often leads to a helical structure consisting of two counter-rotating sets of spirals. Similar arrangements (parastichies) are found for the petals, florets, stamens, etc. of many flowers. Douady and Couder [Phys. Rev. Lett. 68, 2098...

In the paper, the weather generator WGENK producing synthetic daily data of solar radiation, maximum and minimum temperature, and total precipitation is presented. A WGENK model, modification of WGEN model, introduces annual courses of transition probability, α parameter of Γ distribution, and...

Recently, a vaccine for human papillomavirus was introduced, but made available only for girls and adult women aged 13–26. Since rates of sexual activity vary by age and gender, vaccinating only an age-limited subset of one cohort may be insufficient to control the disease across all age...