Neutrophils are the most common type of white blood cell, comprising about 50-70% of all white blood cells. They are phagocytic, meaning that they can ingest other cells, though they do not survive the act. Neutrophils are the first immune cells to arrive at a site of infection, through a process known as chemotaxis.
One of the basic theories stipulates that increasing interest rates raise consumers' and manufacturers' costs, which, in turn, reduces the amount of time and money people spend driving. Less people on the road translates to less demand for oil, which can cause oil prices to drop.
The question on just about every bond investor's mind is simply this: When will interest rates rise? With rates on most types of debt near record lows, it seems that rates have nowhere to go but up. That would send bond prices down. And with yields at such depressed levels, the amount that investors stand to lose from a jump in rates has grown (the lower a bond's yield falls, the more it will lose in price from a rise in rates).