We obtain a criterion for pulsating front speed-up by general periodic incompressible flows in two dimensions and in the presence of KPP nonlinearities. We achieve this by showing that the ratio of the minimal front speed and the effective diffusivity of the flow is bounded away from zero and infinity by constants independent of the flow. We also study speed-up of reaction-diffusion fronts by v...

objective: the purpose of this study was to examine the role of parenting styles in predicting behavioral and emotional problems in adolescents.  methods: this study is a descriptive, cross sectional, and correlation research. all students enrolled in the first grade in boys’ guidance school of district 3 in tehran city and their parents constituted the population. one hundred and eighty partic...