UPI NewsTrack Health and Science News

NASA: Spirit still stuck in Martian sand

PASADENA, Calif., July 9 (UPI) -- U.S. space agency engineers said they used backward motion during the second evaluation of maneuvers that might free a stuck Mars rover.

NASA's Mars rover Spirit became trapped in April in loose martian sand. Jet Propulsion Laboratory engineers in California have been using a test rover placed in a specially constructed sandbox to simulate how to best extract Spirit.

During the first evaluation, conducted Monday, the engineers experimented with simply moving the rover forward. That proved unsuccessful when the test unit moved only slightly forward before sliding sideways down a slope.

The second evaluation was conducted Wednesday, but results were not announced.

"Weeks of further testing and analysis are expected before engineers identify the best moves to command Spirit to perform," NASA said in a statement. "Meanwhile, Spirit is using its science instruments to examine the environment surrounding (it) on Mars."

Antacid drugs may lead to dependency

COPENHAGEN, Denmark, July 9 (UPI) -- Findings of a Danish study suggest the use of proton pump inhibitors can produce acid-related symptoms in healthy adults.

Proton pump inhibitors are a group of drugs used to cause a pronounced and long-lasting reduction of gastric acid production and are among the most widely selling drugs in the world, Wikipedia said.

But results of an eight-week, randomized, double-blind placebo-controlled trial led by Dr. Christina Reimer of Copenhagen University suggests proton pump inhibitors can induce acid-related symptoms in healthy individuals once treatment is withdrawn.

"The observation that more than 40 percent of healthy volunteers, who have never been bothered by heartburn, acid regurgitation or dyspepsia develop such symptoms in the weeks after cessation of PPIs is remarkable and has potentially important clinical and economic implications," Reimer said. "This study indicates unrecognized aspects of PPI withdrawal and is a very strong indication of a clinically significant acid rebound phenomenon that needs to be investigated in proper patient populations."

The research is reported in the journal Gastroenterology.

Frozen carbon a climate change threat

CANBERRA, Australia, July 9 (UPI) -- An Australian-led team of scientists says it has determined the amount of frozen carbon in Earth's northern regions is more than double previous estimates.

"We now estimate the deposits contain over 1.5 trillion tons of frozen carbon, about twice as much carbon as contained in the atmosphere", said Charles Tarnocai of Agriculture and Agri-Food Canada, the study's lead author.

Pep Canadell, executive director of Australia's Global Carbon Project and study co-author, said the existence of super-sized deposits of frozen carbon means any thawing of permafrost due to global warming might lead to significant emissions of carbon dioxide and methane -- both greenhouse gases.

"Radioactive carbon dating shows that most of the carbon dioxide currently emitted by thawing soils in Alaska was formed and frozen thousands of years ago," University of Florida Professor Ted Schuur said. And that, he noted, demonstrates "how easily carbon decomposes when soils thaw under warmer conditions."

Canadell said permafrost carbon is a wild card in efforts to predict climate change. He said evidence suggests carbon in permafrost is likely to play a significant role in the 21st century's climate.

Carbon in permafrost is found largely in northern regions including Canada, Greenland, Kazakhstan, Mongolia, Russia, Scandinavia and the United States.

The research appears in the journal Global Biogeochemical Cycles and was recently published in the journal Nature.

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Cancer, non-cancer cells have similarities

EVANSTON, Ill., July 9 (UPI) -- U.S. scientists say they have discovered cancerous and non-cancerous cells share similar structural abnormalities.

The Northwestern University-led researchers said although the cells appear quite different under a microscope, they used an optical technique called partial wave spectroscopy and found the similar features at the nanoscale level.

The scientists said their finding marks the first such discovery and validates the "field effect" -- a biological phenomenon in which cells located some distance from a malignant or premalignant tumor undergo molecular and other kinds of abnormal changes. In another important finding, the scientists said abnormalities in the nanoarchitecture of colon cells are the same abnormalities as those found in the pancreas and lung, illustrating commonality across three very different organs.

"Our data provide a strong argument that these nanoscale changes are general phenomena in carcinogenesis and occur early in the process," Professor Vadim Backman, the paper's senior author, said. "These changes occur not only in cancer cells, but in cells far from the tumor site and are the same in at least three different types of cancer. "Given its ability to detect these changes, PWS could be used in the early screening of a variety of cancers."

The study that included researchers from Chicago's NorthShore University Health System appears in the journal Cancer Research.