A team of environmental scientists believes that global warming will have a negative impact on tropical fish populations. They design an experiment to model the effects of global warming. First, they fill two aquariums with salt water and put a dozen tropical fish in each. The water temperature in both aquariums begins at 25 degrees C. Aquarium A is kept at a consistent 25 degrees C, but Aquarium B's water temperature is gradually raised by 1 degree C each week of the experiment. At the end of week 8, 8 of the 12 fish in Aquarium A survived and 9 of 12 fish in Aquarium B survived. The scientists conclude that global warming does not pose a significant threat to tropical fish. What was the independent variable and what is the dependent variable?

A35-year-old woman comes to the ed complaining of chest pressure. she has had such episodes intermittently over the last 5 years, usually when sleeping, but over the last year she has had more frequent severe symptoms that are occasionally associated with severe migraine headaches. the pain is midsternal and is described as pressure that extends as a band around her chest. the ed physician is initially dubious that the pain is cardiac in origin, because the woman has no coronary disease risk factors. an ecg, however, shows 2mm st-segment elevation and inverted t waves in leads v1 through v5 and 1mm st-segment depression in leads ii, iii, and avf. before the cardiologist arrives in the ed, the patient's ecg has returned to normal. this repeat normal ecg is obtained after the administration of aspirin, nitroglycerin, morphine, and oxygen. which of the following is most likely for these findings? - diffuse intimal thickening with focal areas of atherosclerotic narrowing - intermittent thrombus formation and lysis in the left anterior descending artery - intermittent thrombus formation and lysis in the right coronary artery - plaque rupture and thrombus formation in the left anterior descending artery - transiently increased coronary vascular tone in the right coronary artery