Combination vaccines have become the preferred choice for immunizing children in high- and middle-income countries. However, these new vaccines are prohibitively expensive for low-income countries, causing them to rely on older, less-expensive vaccines. This product divergence decreases...

Vaccination is one of the most important and successful public health endeavors in human history, profoundly reducing mortalities caused by infectious diseases. In the United States, the comprehensive success of large scale pediatric immunization programs results from the collaboration of an...

Based on fractal theory, this paper studies the fluctuation characteristics of the gold market in China. Using R/S analysis and fractal dimension analysis this paper demonstrates that the gold market possesses fractal characteristics and determines the length of the aperiodic circulation on the...