Study casts doubt on 'killer mushrooms'
HAMILTON, Ontario, Dec. 6 (UPI) -- A Canadian biologist say his trek in southwestern China has shattered a myth of "killer mushrooms" being responsible for 400 unexplained deaths in the region.
Jianping Xu of McMaster University in Ontario said his investigations were triggered by a 2010 article in the journal Science, claiming Trogia venenata mushrooms contained high concentrations of the metal barium and linking them with high blood pressure, cardiac arrests and sudden deaths in southwestern China over the past 30 years.
"Although there was no published evidence supporting the theory that barium in the T. venenata mushroom was the leading culprit of what was called Sudden Unexplained Death, it was picked up as a fact by almost all of the major news media," biology Professor Xu said. "These reports caused significant concern among the public about potentially high levels of barium in wild edible mushrooms in southwest China."
Every summer for the last four years Xu and colleagues have trekked across the Yunnan province, collecting T. venenata and other mushrooms from villages severely impacted by these deaths.
Analysis of the mushrooms found barium concentrations so low a 150-pound person would have to ingest at least 75 pounds of dried T. venenata to create a lethal amount, the researchers said.
While barium can't be completely ruled out as a contributor to the deaths since high levels of the metal were found in the blood, urine and hair samples of some victims, Xu said, his study does suggest that barium in mushrooms was unlikely the leading cause.
"Though there are a couple of leads," he said, "further investigation is needed to discover what the true cause was for these mysterious deaths."
Flexible solar cells could be in clothing
UNIVERSITY PARK, Pa., Dec. 6 (UPI) -- The day may come when the shirt on your back can charge your cellphone, say U.S. researchers who've helped developed flexible, foldable solar cells.
Scientists at Penn State, who worked with international colleagues, said the silicon-based optical fiber with solar-cell capabilities can be made to almost any length and paves the way for flexible, curved or twisted solar fabrics.
The team worked to overcome the challenge of merging optical fibers with silicon-based integrated circuits found in most semiconductor electronic devices such as solar cells, computers, and cellphones, a university release said Thursday.
The solution was an optical fiber thinner than a human hair, with its own integrated electronic component, bypassing the problem of having to integrate fiber-optics with flat electronic chips.
"Our goal is to extend high-performance electronic and solar-cell function to longer lengths and to more flexible forms. We already have made meters-long fibers but, in principle, our team's new method could be used to create bendable silicon solar-cell fibers of over 10 meters in length," Penn State chemistry Professor John Badding said.
"Long, fiber-based solar cells give us the potential to do something we couldn't really do before: We can take the silicon fibers and weave them together into a fabric with a wide range of applications such as power generation, battery charging, chemical sensing and biomedical devices."
Most current solar cells are expensive to produce and create a flat, inflexible device, he said.
"But woven, fiber-based solar cells would be lightweight, flexible configurations that are portable, foldable and even wearable," he said.
The military has shown great interest in wearable power sources for soldiers in the field, Badding said.
Hubble observes cosmic 'bulls-eye' galaxy
PARIS, Dec. 6 (UPI) -- The Hubble telescope has captured an image of a distant galaxy that was a target bulls-eye in a cosmic collision with another galaxy, European astronomers say.
The image of galaxy NGC 922 reveals not a normal spiral galaxy but one whose arms are disrupted, with a stream of stars extending outward and a bright ring of nebulae encircling the core, a release from the European Space Agency's Paris headquarters reported Thursday.
Those features are the evidence of a cosmic bulls-eye millions of years ago when a smaller galaxy smashed through the center of NGC 922 and sailed out the other side, astronomers said.
The collision created ripples that disrupted the clouds of gas in NGC 922, triggering the formation of new stars whose radiation then lit up the remaining gas creating the bright pink color seen in the space telescope image, they said.
This process of excitation and emission of light by gases is similar to what happens in neon signs, astronomers said.
Objects like NGC 922, dubbed collisional ring galaxies, are relatively rare in our cosmic neighborhood, they said.
While galaxy collisions and mergers are commonplace, the precise alignment and ratio of the colliding galaxies' sizes needed to create a ring such as the one seen in NGC 922 is unusual, they said.
Geography, not social media, makes friends
TROY, N.Y., Dec. 6 (UPI) -- You are more likely to make friends with people you live close to despite the rise in the use of social media to "friend" people, a U.S. study found.
Using data from the location-based social network provider Gowalla, researchers at Rensselaer Polytechnic Institute in New York found people tend to move in groups of friends and that two people chosen at random at a specific event, like a concert or at a particular store, are unlikely to be friends.
The findings, although seeming common sense, could have an impact on predictions of how people move, which could affect application that rely on such predictions for emergency planning, infrastructure development, communications networks and disease control, researchers said.
"The ramifications are extremely important because if we assume that people are moving randomly, we are wrong, and therefore we will not be prepared for what people actually do," Rensselaer computer scientist Boleslaw Szymanski said. "Where you live really matters: Most of your friends are concentrated in the place where you live, and as the distance increases, this concentration rapidly drops."
The study suggests still form friendships based on personal interactions despite the rise of social media in the digital age, the researchers said.
"Even though, thanks to the Internet, you can be friends with anyone on the planet, the likelihood that a person will be friends with someone in a distant location chosen at random is far lower than the likelihood that this person will be friends with someone who lives in close proximity," Rensselaer graduate student Tommy Nguyen said.
As distance increases the likelihood of friendship between two people decreases, so 80 percent of a particular person's friends live within 600 miles of that person's home, the study found.
"Proximity creates a strong boundary for who will be your friends," Nguyen said.
