Science - Snippets

From Vol. 168 of my favorite magazine, Science News:

Silicon biosensors with nanoscale pores are being delivered in a gel that would change color to indicate the presence of infection. Lisa A. DeLouise, a biomaterials scientist at the University of Rochester (NY) Medical Center has worked with her colleagues to create a matrix sufficiently flexible to carry the silicon biosensors and be applied directly to wounds. They have developed the gel which can be used in smart bandages.

Breathlessness (dyspnea) brought on by minor effort might well be a signal of something deadlier. Daniel S. Berman of Cedars-Sinai Medical Center and the University of California, Los Angeles, working with a team of scientists, has found that patients diagnosed with dyspnea have a greater risk of dying from heart problems than patients with chest tightness (angina). Dyspnea sufferers were also more likely than patients in other groups to die of problems not linked to the heart. Their risk of death remained higher even when researchers accounted for such factors as a history of diabetes. These results agree with those of a smaller study conducted by Patricia A. Pellikka, a cardiologist at the Mayo Clinic College of Medicine in Rochester, Minn., and her colleagues. So, if you have difficulty breathing after any exertion at all, ask your doctor to perform a cardiac evaluation and stress test. Berman's study showed that dyspnea sufferers tended to have an enlarged left ventricle, which is a sign of chronic stress on the heart.

Male mice might communicate with prospective mates at a pitch approximately 2 octaves higher than the highest sound audible to the human ear. According to Timothy E. Holy and Guo Zhong Sheng of Washington University in St. Louis, this "song" is comparable in complexity to the song of birds and whales. Neurophysiologist Wang Xiao Qin of Johns Hopkins University School of Medicine in Baltimore does not necessarily agree that the mouse vocalizations are song, which require an element of learning, but admits that the discovery could have important implications for the study of communication. Mouse pups also vocalize at a very high pitch when separated from their mothers, which leads their mothers to look for them. You can listen to the mouse song here. Brominated fire retardants are added to plastic to keep it from being dangerously flammable. However, such substances accumulate throughout the environment, including in human breast milk, and pose dangers to life. Kashiwagi Takashi, a materials engineer at NIST (National Institute of Standards and Technology) in Gaithersburg, Md., has shown that adding nanoscale particles of alumina silicate to polymer samples reduces flammability. Kashiwagi and Jack F. Douglas, also of NIST, used past work by Kashiwagi to add carbon nanotubes to flammable polymer samples and found that the best samples burned only about 40 per cent as fast as samples without tubes.

Stephen T. Chambers, a physician at the University of Otago in New Zealand has, in conjunction with his colleagues, devised a breath test that can detect the fungal lung infection caused by Aspergillus fumigatus. When tested using gas chromatography and mass spectroscopy, patients infected with the fungus were found to have a substance called 2-pentylfuran in their breath. A. fumigatus causes infections in people whose immune systems have been compromised, such as those suffering from cystic fibrosis. Chambers believes the test would be particularly useful for leukemia patients who have received bone marrow transplants, which involve immune system suppression.

Children who are missing a small piece of DNA on chromosome 22 run a substantial risk of developing schizophrenia, according to Allan L. Reiss of Stanford University School of Medicine and his colleagues. This occurs approximately once in 4,000 births, and 30 per cent of such youngsters eventually develop schizophrenia or related psychotic conditions. Such children often also have heart defects, cleft palates, and learning disorders. Prior studies have shown that such people also lack one copy of the usual two of the COMT gene. This gene triggers production of a protein that breaks down dopamine, a neurotransmitter. The protein can be weak or strong. Children with the weak COMT variant, which permits excessive amounts of dopamine in the brain, showed lower verbal intelligence, and language skills and harsher psychotic symptoms than those with the strong COMT variant. Also, children with the weak COMT variant showed greater shrinkage in the prefrontal brain area, which is linked to schizophrenia.

Science News is available online. However, not all articles are hosted on their site. The subscription is well worth the expense, though. Plus, it's so well-written, it's a joy to read, and it offers a roundup of every field of scientific endeavour. Bonus: It'll get your kid(s) interested in science. I've been reading it for some years now. No, I don't get a discount on my subscription for raving about the mag. I just really like it, is all.

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