Snippets from Science

• The smartest birds are members of the genus Corvus, which includes crows, ravens, and rooks (a European version of our crow). Recent studies published in the prestigious Proceedings of the National Academy of Sciences (May, 2009) demonstrate the tool-making ability of rooks. Rooks were placed in a cage containing a 4-inch Plexiglas tube standing on end. At the bottom of the tube was a small basket with a handle, and a worm was placed in the basket. The rooks had no idea how to get the worm until a 5-inch piece of wire was placed in its cage. Without hesitation, most of them grabbed the wire and bent one end into a hook. Taking the other end in its beak, they thrust the wire into the tube and retrieved the basket. Other experiments involved tubes of various diameters, and the rooks had to select a proper sized rock and drop it into the tube to get a worm. The remarkable finding was that the rooks selected just the right sized rock each time, without training. The authors conclude that tool-making in rooks may be on par with that of chimps.

• Neurotransmitters are chemicals that enable electrical impulses to travel between nerve cells, and a chain of these cells carries impulses along the length of the nerve. An interesting neurotransmitter called “Substance P” is involved in communicating impulses to our brains that cause us to perceive pain. In our bodies, Substance P nerve cells are triggered by heat, pressure, inflammation, or areas of damaged tissue. They send signals to the brain, which interprets the signals as pain, and makes us conscious of the presence and intensity of the pain, as well as its origin. Substance P generally exists in abnormally high amounts in fibromyalgia patients. At the other end of the spectrum, one kind of rat completely lacks Substance P— and does not feel painful stimuli administered to its skin.

• There has been a 30 percent rise in mercury contamination in the north Pacific Ocean since the mid-1990s, according to a study in the May issue of Global Biogeochemical Cycles. When mercury is converted into methyl mercury, as it is in living systems, it is a potent neurotoxin, especially in young animals.

• Speaking of contamination of the oceans, there’s good news and bad news. The oceans are the largest “natural reservoirs” (or sinks) of excess carbon dioxide, and they absorb about a third of the carbon dioxide produced by human activities. Good news! The bad news is that excess carbon dioxide absorption results in an increase in acidity in our oceans, and some sea life is very sensitive to even tiny changes in acidity. (Office of Oceanic and Atmospheric Research (NOAA) and a report from the Royal Society of Great Britain)

• Swimmer’s itch is caused by a tiny larval stage of a flatworm parasite. These water-dwelling larvae attach to and penetrate the surface of the skin, causing irritation. A similar thing occurs in the Far East and Africa, where the larvae of the flatworm Schistosoma mansoni cause “snail itch” in people bathing or swimming in lakes. The larvae get into the bloodstream and cause the world’s second most prevalent tropical disease, Schistosomiasis, which can lead to fever, diarrhea, swollen stomachs, bladder cancer, liver damage, and even death. Fortunately, the larvae causing skin itch in Lake Michigan swimmers die once they penetrate the skin, which causes mild irritation.