Cooking at a constant oven temperature of 300Â°F (160Â°C), a 5- to 8-lb standing rib roast will take 17-19 minutes per pound for rare, 20-22 for medium rare, 23-25 minutes for medium, and 27-30 minutes for well done.f you roast at 325Â°F (160Â°C), subtract 2 minutes or so per pound. If the roast is refrigerated just before going into the oven, add 2 or 3 minutes per pound. More: Set the roast out an hour or so before putting it in the oven.
The causes of schizophrenia include environmental and genetic factors. Possible environmental factors include being raised in a city, cannabis use, certain infections, parental age, and poor nutrition during pregnancy. Genetic factors include a variety of common and rare genetic variants.
Causes. Autism spectrum disorder has no single known cause. Given the complexity of the disorder, and the fact that symptoms and severity vary, there are probably many causes. Both genetics and environment may play a role. 1  Genetic problems.2  Several different genes appear to be involved in autism spectrum disorder.auses. Autism spectrum disorder has no single known cause. Given the complexity of the disorder, and the fact that symptoms and severity vary, there are probably many causes. Both genetics and environment may play a role. 1  Genetic problems.