It's Jahoviahs Witness that have a problem with blood transfusions, not 7th Day Adventist. Adventists are big believers in modern health care, they operate state of the art hospitals all around the world, and have a well respected medical school (Loma Linda).
Scientists really have to do a better job at communicating clearly with less jargon
While I tend to agree with you about jargon, the ironic thing is that jargon is explicitly created to communicate more clearly. It is all about speaking to your audience, if you are talking to a fellow slashdotter you say "dual core CPU", if you are talking to your grandparents you say "computer with two brains". Both are very clear to their target audience and incomprehensible drivel to the other, so which is "communicating clearly"? Many concepts are very hard to break down into terms of microwave ovens, buying groceries, and fixing your car analogies. But I agree that just because something is hard that we should quit trying.
Consider the postage stamp: its usefulness consists in the ability to stick to one thing till it gets there. -- Josh Billings