Sun now more active than in a millennium
KATLENBURG-LINDAU, Germany, Nov. 3 (UPI) -- A new study indicates the Sun is more active now than it has been for a millennium.
New Scientist magazine said the study by scientists from the Max Planck Institute for Aeronomy in Katlenburg-Lindau, Germany, and the University of Oulu in Finland, shows there have been far more sunspots since the 1940s than for the past 1,150 years.
Researcher Ilya Usoskin, an geophysicist, told New Scientist sunspot observations started during the early 17th century, when the telescope was invented. To extend the data farther back in time, Usoskin's team used a physical model to calculate past sunspot numbers from levels of a radioactive isotope preserved in ice cores taken from Greenland and Antarctica.
New Scientist said the findings may stoke the controversy over the contribution of the Sun to global warming. And although Usoskin and his team are reluctant to be dragged into the debate, the magazine said their work will probably be noted by those who claim temperature rises during the past century are the result of changes in the Sun's output.
The study appears in the journal Physical Review Letters.
Different genes play roles in Alzheimer's
DURHAM, N.C., Nov. 3 (UPI) -- A new study indicates the genes that influence the risk of developing Alzheimer's disease may vary over the course of an individual's lifetime.
Researchers at Duke University Medical Center found two chromosomal regions not previously known to influence Alzheimer's disease: one linked to the disorder in families that first show symptoms early in life and another in families with very late Alzheimer's disease onset.
While earlier studies identified genes underling early- versus late-onset Alzheimer's disease, the new study is the first to indicate distinct genes might also determine the very late onset of Alzheimer's disease, in which symptoms first appear after the age of 80.
Alzheimer's disease affects up to 4 million Americans and is the most common cause of dementia among people over the age of 65. However, some patients first experience at age 50 the mild forgetfulness characteristic of the disease's earliest stages; for others, symptoms appear at age 80 or older.
The research findings appear in the November issue of The American Journal of Human Genetics.
Mercury vaccine-autism study disputed
ATLANTA, Nov. 3 (UPI) -- A study of 124,000 babies found "no consistent significant associations" between mercury-laced vaccines and autism or attention-deficit disorder.
Thimerosal, a mercury-containing preservative, was used for decades to stabilize vaccines and while vaccines today contain little or no thimerosal, it had been suspected by some to be a cause or facilitator of autism and other conditions.
Safe Minds, a Cranford, N.J., an organization dedicated to removing mercury from medical products disputes the study and accuses federal researchers of finding such a link in "earlier, secret studies" and "manipulating data" to cover it up, the Washington Times reported.
Safe Minds leaders allege materials obtained through the Freedom of Information Act found a "plausible" link between thimerosal-containing vaccines and autism.
But federal researchers added data from a Massachusetts HMO even though it had data-management problems and the state is believed to have "severely underreported" its cases of autism to skew the findings, said Lyn Redwood, the mother of an autistic child and president of Safe Minds.
The study is published in the journal Pediatrics.
Breast cancer is reversed in lab mice
SACRAMENTO, Nov. 3 (UPI) -- A new study demonstrates for the first time it is possible to block genetic switches in mice to prevent and even reverse breast cancer in the animals.
Science Daily magazine said the University of California-Davis research team, which included scientists from Canada, and Switzerland, showed removing a single gene known as beta-1 integrin prevented or halted breast cancer growth in laboratory mice. Beta-1 integrin is a principal regulator of normal breast tissue growth and survival, but if the gene malfunctions, it can directly initiate breast tumors.
Science Daily said the study demonstrates disabling the beta-1 integrin gene prevents cancer-prone mice from developing breast tumors and halts further tumor growth in mice that have already developed breast cancer.
A lead investigator, William Muller of McGill University in Montreal, said: "This study shows that it is absolutely essential to have the beta-1 integrin gene present in order for mammary gland tumors to develop. We now have a good target for biological drug development, and the challenge is to develop an agent that can block its activity."
The findings were reported during the weekend at the 24th Congress of the International Association for Breast Cancer Research in Sacramento, Calif.
