Birds' migratory success a complex process
FRANKFURT, Germany, Aug. 22 (UPI) -- Magnetic orientation is critical to many birds' migratory success but recent research suggests birds' orientation powers may be more complex than thought.
By studying the influence of light on the ability of migratory birds to orient to magnetic signals, researchers have found clues suggesting birds may be able to interpret magnetic signals by more than one mechanism.
Researchers Thorsten Ritz of the University of California-Irvine and Wolfgang and Roswitha Wiltschko of the University of Frankfurt, Germany, analyzed the orientation behavior of European robins under turquoise light and discovered increasing the intensity of the light changed the birds' orientation significantly, in comparison to dimmer light levels.
The researchers found in dim turquoise light, similar to that found about 33 minutes after sunset, the birds showed normal migratory orientation, with the seasonal shift between southerly directions in autumn and northerly directions in spring.
However, the researchers also found that under brighter turquoise light, corresponding to light levels found 20 minutes after sunset, the birds still orient by the magnetic field, but they no longer show the seasonal change between spring and autumn and, instead, head north in both seasons.
The work is reported in Current Biology.
First detailed picture of migraine attack
GOTEBORG, Sweden, Aug. 22 (UPI) -- A researcher at Sweden's Göteborg University says he's used a new technique to obtain the first detailed "picture" of an untreated migraine attack.
Migraine is a condition characterized by an intensive pulsing headache, hypersensitivity to light and sound, and-or severe nausea and vomiting.
Dr. Mattias Linde, a medical specialist in neurology and author of the dissertation, asked a number of patients who could refrain from treatment for 72 hours to assess the intensity of their various migraine symptoms.
Using the results, Linde said he was able for the first time to produce a highly exact picture of how a migraine attack develops hour by hour.
The findings refute the common theory that effective migraine drugs must be used early in the course of an attack. Linde compared early and late injection treatment in the same patients. No statistically significant difference was shown.
Linde's dissertation at the university's Sahgrenska Academy is to be publicly defended Sept. 2.
Study: Skin cells turned into stem cells
BOSTON, Aug. 22 (UPI) -- The controversy over embryonic stem cell research may become moot with a procedure that turns skin cells into what appear to be embryonic stem cells.
A Harvard University research team said it devised the procedure without having to use human eggs or make new human embryos in the process, The Washington Post reported Monday.
The technique uses laboratory-grown human embryonic stem cells -- such as ones President Bush previously approved for use by federally funded researchers, the Post said. Those cells are used "reprogram" genes in a person's skin cells, turning the skin cells into embryonic stem cells.
If confirmed by subsequent research, the procedure could end the bitter controversy that has stymied human embryonic stem cell research in the United States.
The research is detailed this week in the journal Science.
Sneaky compound kills brain cancer cells
ST. LOUIS, Aug. 22 (UPI) -- A compound that kills cancer can sneak past the blood brain barrier to do its work in fighting a particularly invasive brain cancer.
"The bottom line is, if you can get drugs into the brain, you can cure brain cancer," said Dr. William Banks of the St. Louis University School of Medicine.
The compound -- JV-1-36 -- is an antagonist of the hypothalamic growth hormone, which has been found to cause cancerous tumors, such as malignant glioblastomas, to grow.
Researchers found the blood brain barrier that usually keeps anti-cancer drugs out of the brain, intercepted some of the JV-1-36 that was injected into mice, but allowed much of it pass into the brain to treat cancer.
"The blood brain barrier is set up to very carefully patrol what it lets into the brain and what it keeps out. It makes these decisions based on the physicochemical properties," said Banks "Most of our drugs that fight cancers are toxic to cancer cells and to other cells, too. That's why the blood brain barrier locks them out of the brain."
The findings appear in the online early edition of the Proceedings of the National Academy of Sciences.
