Rover Opportunity begins making decisions
PASADENA, Calif., March 24 (UPI) -- NASA says its Mars rover Opportunity is now capable of choosing what observations it makes on arrival at a new location.
NASA scientists said they uploaded software during the winter to take advantage of the rover's unanticipated longevity to test robotics advances that will be used in future missions.
Opportunity landed on Mars in 2004 and began a mission designed to last several months. The rover is now in its seventh year of operation.
The new software allows Opportunity's computer to examine images taken with its navigation camera after a drive to a new location. The software can recognize rocks meeting specified criteria and the rover then takes multiple images of the chosen target.
NASA said without the new system, follow-up observations depend on first transmitting post-drive navigation images to scientists at the Jet Propulsion Laboratory in California to check for targets of interest. Because of time and data-volume constraints, the rover team may opt to drive the rover again before potential targets are identified.
The first images taken by Opportunity choosing its own target show a rock about the size of a football, tan in color and layered in texture.
"It found exactly the target we would want it to find," said Tara Estlin of JPL's artificial intelligence group, who added "It's amazing to see Opportunity performing a new autonomous activity after more than six years on Mars."
41 percent in Canada have high cholesterol
OTTAWA, March 24 (UPI) -- Forty-one percent of Canadian adults have a high total cholesterol level, while 4 percent are vitamin D-deficient, a report by Statistics Canada said.
The findings are included in the second data release from the Canadian Health Measures Survey, which collected key information about the health of Canadians by means of direct physical measurements.
The survey tested blood samples of participants for a number of lipids -- a class of fats that include cholesterol and triglycerides and for vitamin D and other nutrition markers.
About 36 percent of adult Canadians had unhealthy levels of low density lipoprotein, the "bad" cholesterol, while 30 percent had unhealthy levels of high density lipoprotein, the "good" cholesterol.
Unhealthy levels of LDL cholesterol generally increase with age, but peaked at 43 percent among adults aged 40-59, the report said. About 5 percent of men and 3 percent of women ages 6-79 were considered vitamin D-deficient, the report said.
The survey samples were collected from March 2007 to February 2009 from a representative sample of about 5,600 Canadians ages 6-79 years at 15 sites across the country.
Study: Apes have metacognitive ability
LEIPZIG, Germany, March 24 (UPI) -- German scientists say they have determined great apes realize they can make mistakes when making choices.
The study, led by Josep Call at the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, consisted of three experiments involving gorillas, chimpanzees, bonobos and orangutans.
Each animal was presented with two hollow tubes, one baited with a food reward, the other empty.
In the first experiment, the apes were prevented from watching the baiting, but the tubes were shaken to give them auditory information.
In the second experiment, they were shown the location of the food and then, at variable time delays, encouraged to retrieve it.
In the last experiment, researchers compared the apes' response between visible and hidden baiting when the quality of the food reward varied.
The scientists found the apes were more likely to check inside the tube before choosing when high stakes were involved, or after a longer period of time had elapsed between baiting and retrieval. In contrast, when they were provided auditory information, they reduced the amount of checking before choosing.
Call said, taken together, the findings show the apes displayed metacognition, defined as "cognition about cognition," or knowing about knowing, and were aware their decisions might be wrong.
The study is detailed in the journal Animal Cognition.
Radiotherapy can cause vascular disease
STOCKHOLM, Sweden, March 24 (UPI) -- Swedish researchers say cancer radiotherapy can increase the risk of cardiovascular disease and the cause might be changes in arterial gene expression.
Karolinska Institute scientists say their new study suggests sustained inflammation induced by post-radiotherapy changes in the gene expression in the arteries could be causing increases in the risk of cardiovascular disease in the same part of the body. For example, they point to heart attacks occurring after left-side breast cancer treatment, or strokes occurring after the treatment of head, neck or brain tumors.
"Studies have been hampered by the fact that the disease process is so slow," said Karolinska researcher Martin Halle. "Cell studies and animal studies are best suited to the more immediate effects, and studies on human subjects have been ruled out for ethical reasons."
But in the new study, the researchers found irradiated arteries showed signs of chronic inflammation and an increase in activity of a genetic factor known for playing a key part in the development of atherosclerosis. The greater inflammatory gene expression was visible for several years after irradiation, and might, the researchers said, explain why cancer patients can suffer cardiovascular disease many years after radiotherapy.
"Hopefully, these findings will one day help medicine to mitigate the side effects by administering radiotherapy in combination with an anti-inflammatory treatment," Halle said.
The study is presented in the Journal of the American College of Cardiology.
