Question

In a study investigating obesity and myocardial infarction (MI), the following results were obtained. Amongst participants with obesity, a total of 80 MI occurred. Amongst normal weight participants, a total of 40 MI occurred. The group with obesity accumulated 90,000 person-years and the normal weight group 175,000 person-years during the study period.

Calculate the incidence rate difference (per 100,000 person-years).

Answer 1

Explanation:

Bacteria (and archaea) are hardy creatures. They thrive in hot, cold, salty, acidic and alkaline environments in which most eukaryotes would perish. Despite this, they have a bad image: after all, bacteria cause many diseases in humans.

It is in aquatic habitats that the effects of acid rain are most obvious. Acid rain runs off the land and ends up in streams, lakes and marshes - the rain also falls directly on these areas. As the acidity of a lake increases, the water becomes clearer and the numbers of fish and other water animals decline.

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