News in Science
A study finds that humans differ from chimps mostly in regulatory genes, confirming a thrity-year-old hypothesis. They looked at some 1,056 genes in this study across humans and several other primates, and found 60 percent of these had consistent expression levels across all the species. Some 19 genes were found to have significantly different expression levels in humans, and of those, the ones that were themselves transcription factors (that is, they regulate the expression of other genes) were all expressed at a higher rate than in other primates. The researchers say that this is consistent with what we expect in directional selection.
Another study confirms that chronic moderate tinnitus has a negative impact on performance on complex cognitive tasks. “Tinnitus is the perception of sound in the absence of auditory stimulation. Described as a “ringing in the ears” or “buzzing” or “whooshing” sound, it can be temporary, intermittent, or permanent.” What they do not say here is that tinnitus is often not merely something going haywire inside the brain, but is actually correlated with otoacoustic emission of sound. Many people don’t know that ears not only receive sound, but can produce it as well. This has been used to measure hearing in young children, and especially in people who cannot be instructed to respond to tones in a hearing test. The auditory system responds with an otoacoustic emission of similar frequency to a test tone, and tiny microphones in the ear canal can detect these otoacoustic emissions. In people with tinnitus, this process sometimes occurs inappropriately and continues long beyond any triggering stimulus.
A researcher at Purdue University claims to have achieved nuclear fusion in a tabletop apparatus. No, it isn’t “cold fusion”, the phenomenon claimed in work with electrically charged paladium grids in water. Instead, Prof. Rusi P. Taleyarkhan says that he observed fusion in “a small tabletop device by blasting a jar of solvent with strong ultrasound vibrations.”
In their 2002 report, Dr. Taleyarkhan and his colleagues said fusion had been created when the ultrasonic vibrations caused small gas bubbles in the solvent to collapse quickly, generating superhot temperatures where fusion could occur.
So this is “cavitation fusion”, not “cold fusion”. Everybody got that? This should be interesting to see play out. There’s a lot of skepticism, and Purdue is investigating the research, especially since at the moment it appears to be irreproducible. Cavitation is itself a pretty widespread phenomenon. Snapping shrimp famously use cavitation in stunning prey, with a highly modified pincer providing the means of generating cavitation. Those studying cavitation have long noted its high-energy results, as free radicals are produced in suitable solutions. As such, cavitation is pretty corrosive to living tissue, which goes some way to explaining why snapping shrimp generate it externally.
Update: I used the phrase “cavitation fusion” as an apt descriptor of what was in Kenneth Chang’s report linked above, though the phrase does not occur in the article. However, a quick Google search shows that this is, indeed, the appropriate term, and that there are a number of published papers using the phrase.
