Scientists at the Alaska Stable Isotope Facility can tell you whether marijuana came from Mexico or the Matanuska Valley. Soon they'll even be able to tell you whether it was grown indoors or out.

A few more years and enough samples and they hope to have something even more precise: an elemental fingerprint that could tell police where and under what conditions a sample of marijuana was grown.

"There are scientists already doing this for drugs like heroin and cocaine," said Matthew Wooller, Alaska Stable Isotope Facility director. "The potential is there for being able to do this for marijuana as well."

Human resistance to a retrovirus that infected chimpanzees and other nonhuman primates 4 million years ago ironically may be at least partially responsible for the susceptibility of humans to HIV infection today.

These findings, reported by a team of researchers at Fred Hutchinson Cancer Research Center in the June 22 issue of Science, provide a better understanding of this modern pandemic infection through the study of an ancient virus called Pan troglodytes endogenous retrovirus, or PtERV1.

"This ancient virus is a battle that humans have already won. Humans are not susceptible to it and have probably been resistant throughout millennia," said senior author Michael Emerman, Ph.D., a member of the Human Biology and Basic Sciences divisions at the Hutchinson Center.

Using mathematical theory, UC Irvine scientists have shed light on one of cancer’s most troubling puzzles -- how cancer cells can alter their own genetic makeup to accelerate tumor growth. The discovery shows for the first time why this change occurs, providing insight into how cancerous tumors thrive and a potential foundation for future cancer treatments.

UCI mathematicians Natalia Komarova, Alexander Sadovsky and Frederic Wan looked at cancer from the point of view of a tumor and asked: What can a tumor do to optimize its own growth" They focused on the phenomenon of genetic instability, a common feature of cancer in which cells mutate at an abnormally fast rate.

The extinction of many large mammals at the end of the Ice Age may have packed an even bigger punch than scientists have realized. To the list of victims such as woolly mammoths and saber-toothed cats, a Smithsonian-led team of scientists has added one more: a highly carnivorous form of wolf that lived in Alaska, north of the ice sheets.

Wolves were generally thought to have survived the end-Pleistocene extinction relatively unscathed. But this previously unrecognized type of wolf appears to have vanished without a trace some 12,000 years ago.

The study combined genetic and chemical analyses with more conventional paleontological study of the morphology, or form, of the fossilized skeletal remains.

By making careful observations of the growth of a layer of molecules as they gradually cover the surface of a small silicon rectangle, researchers from the National Institute of Standards and Technology (NIST) and North Carolina State University (NCSU) have gained basic insights into how self-propagating self-assembly wave fronts develop and have produced the first experimental verification of recently improved theoretical models of such systems.

In the first trial of its kind in the world, 60 patients who have recently suffered a major heart attack will be injected with selected stem cells from their own bone marrow during routine coronary bypass surgery.

The Bristol trial will test whether the stem cells will repair heart muscle cells damaged by the heart attack, by preventing late scar formation and hence impaired heart contraction.

Dr Raimondo Ascione from the University of Bristol and colleagues at the Bristol Heart Institute (BHI) have been awarded a grant of £210,000 from the British Heart Foundation (BHF) to conduct the clinical trial.