Social networking sites encourage people to be more public about their personal lives. Because intimate details of our lives can be posted so easily, users are prone to bypass the filters they might normally employ when talking about their private lives. What's more, the things they post remain available indefinitely. While at one moment a photo of friends doing shots at a party may seem harmless, the image may appear less attractive in the context of an employer doing a background check. While most sites allow their users to control who sees the things they've posted, such limitations are often forgotten, can be difficult to control or don't work as well as advertised.
The heart and blood vessels comprise the two elements of the cardiovascular system that work together in providing nourishment and oxygen to the organs of the body. The activity of these two elements is also coordinated in the body's response to stress. Acute stress — stress that is momentary or short-term such as meeting deadlines, being stuck in traffic or suddenly slamming on the brakes to avoid an accident — causes an increase in heart rate and stronger contractions of the heart muscle, with the stress hormones — adrenaline, noradrenaline and cortisol — acting as messengers for these effects. In addition, the blood vessels that direct blood to the large muscles and the heart dilate, thereby increasing the amount of blood pumped to these parts of the body and elevating blood pressure. This is also known as the fight or flight response. Once the acute stress episode has passed, the body returns to its normal state.
Although fluoride advocates have claimed for years that the safety of fluoride in dentistry is exhaustively documented and “beyond debate,” the Chairman of the National Research Council’s (NRC) comprehensive fluoride review, Dr. John Doull, recently stated that: “when we looked at the studies that have been done, we found that many of these questions are unsettled and we have much less information than we should, considering how long this [fluoridation] has been going on. I think that’s why fluoridation is still being challenged so many years after it began.”