The running ability of Tyrannosaurus rex has been intensively studied due to its relevance to interpretations of feeding behaviour and the biomechanics of scaling in giant predatory dinosaurs. Different studies using differing methodologies have produced a very wide range of top speed estimates and there is therefore a need to develop techniques that can improve these predictions. Here we present a new approach that combines two separate biomechanical techniques (multibody dynamic analysis and skeletal stress analysis) to demonstrate that true running gaits would probably lead to unacceptably high skeletal loads in T. rex . Combining these two approaches reduces the high-level of uncertainty in previous predictions associated with unknown soft tissue parameters in dinosaurs, and demonstrates that the relatively long limb segments of T. rex —long argued to indicate competent running ability—would actually have mechanically limited this species to walking gaits. Being limited to walking speeds contradicts arguments of high-speed pursuit predation for the largest bipedal dinosaurs like T. rex , and demonstrates the power of multiphysics approaches for locomotor reconstructions of extinct animals.
The problem of teen gang violence can be eliminated. It will, however, take time, money, and a combined effort on the part of many people. Organized, free, after-school programs such as: sports teams and games; art, music, and drama activities; internships in local area businesses and professional organizations; and interesting volunteer activities in the community would help engage teens in worthwhile pursuits outside of school hours. More job opportunities for teens, especially those funded by state and local programs, would offer income for teens as well as productive work for the community. Outreach to families through schools, community organizations, and places of worship would help promote inter-generational activities that could improve family closeness, helping teens to work on their problems at the family level, instead of taking them to the streets. If these programs can be implemented, we will surely see a decrease in teen gang activity and safer streets and neighborhoods for us all.