Researchers determine the cause of underwater waves
Hard-to-detect underwater waves can tower hundreds of feet, with profound effects on the Earth’s climate and on ocean ecosystems.
New research has solved a long-standing mystery about exactly how the largest known internal waves, in the South China Sea, are produced. The findings come from a team effort involving the Massachusetts Institute of Technology and several other institutions.
The solitary waves have been observed to reach heights of more than 550 feet and can travel at a leisurely pace of a few centimeters per second. “They are the lumbering giants of the ocean,” said Thomas Peacock, an engineering professor at MIT.
The team’s large-scale lab experiments used a detailed topographic model of the Luzon Strait’s seafloor, mounted in a 50-foot-diameter rotating tank in Grenoble, France, the largest such facility in the world. The experiments showed that these waves are generated by the entire ridge system on that area of seafloor, and not a localized hotspot within the ridge.
The results were published in the journal Geophysical Research Letters. web.mit.edu/newsoffice
New and fluorescent light on ulcer-causing bacteria
Researchers from the University of Southern Denmark report they have developed a new, safer and noninvasive diagnostic technique for ulcers. The trick is to make the ulcer-causing bacteria turn fluorescent green in the stomach, and send in a micro-camera to see it.
Ulcers are often caused by the bacteria Helicobacter pylori, which produces ulcers in the stomach or duodenum. Usually, a doctor retrieves a tissue sample from the stomach and has it analyzed.
Scientists have for some time been able to make tissue samples from the stomach glow fluorescent green if the tissue is infected with H. pylori bacteria. In the Danish lab, the scientists made H. pylori glow green in artificial tissue that mimics the lining of the human stomach.
They had to create special molecules that can both detect H. pylori bacteria and function at the temperature of the stomach – about 98.6 Fahrenheit. The molecule also had to be able to function in the extremely acidic environment of the stomach. The research results were published in the journal PLOS ONE. sdu.dk
Pompeii’s poor didn’t scrounge for scraps
University of Cincinnati archaeologists are turning up discoveries in the famed Roman city of Pompeii that are wiping out the historic perceptions that the rich enjoyed delicacies such as flamingos while the poor scrounged for soup or gruel.
The archaeologists spent more than a decade at two city blocks in a nonelite district in Pompeii, which was buried under a volcano in AD 79.
Findings revealed foods that would have been inexpensive and widely available, such as grains, fruits, nuts, olives, lentils, local fish and chicken eggs, as well as minimal cuts of more expensive meat and salted fish from Spain. But a drain from one property revealed a richer variety of foods as well as imports from outside Italy, such as shellfish, sea urchin and even delicacies including the butchered leg joint of a giraffe. The discoveries were presented this month at the joint annual meeting of the Archaeological Institute of America and American Philological Association. uc.edu/news