Today's Globe: stroke risk clues, next year's flu vaccine, DNA migration, Google health records, Avastin ruling

What do mammograms, blood-sugar tests, and daytime dozing have in common? All may offer clues that someone is headed for a stroke, new studies suggest. Higher stroke risk was seen in women with artery buildups accidentally revealed by mammograms, in nondiabetics starting to have insulin problems, and in older people who tend to nod off a lot.

Scrutinizing the DNA of 938 people from 51 distinct populations around the world, geneticists have created a detailed map of how humans spread from their home base in sub-Saharan Africa to populate the farthest reaches of the globe over the past 100,000 years.

Next year's flu vaccine is getting an overhaul to provide protection against three new and different influenza strains - with hope it is better protection than this year's version.

Google Inc. will begin storing the medical records of a few thousand people as it tests a long-awaited health service that's likely to raise more concerns about the volume of sensitive information entrusted to the Internet search leader.

A decision expected today on federal approval for Genentech's Avastin cancer drug could have ramifications for all companies developing cancer medicines. Genentech made its case for Food and Drug Administration approval of Avastin using a widely debated measure of drug effectiveness that focuses on tumor growth, not patient survival.