A Little Perspective

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Ashkenazi Jews began as tiny group

All of the Ashkenazi Jews alive today can trace their roots to a group of about 330 people who lived 600 to 800 years ago. So says a new study in the journal Nature Communications. An international team of scientists sequenced the complete genomes of 128 healthy Ashkenazi Jews. Their analysis allowed them to trace the genetic roots of this population to a founding group in the Middle Ages.

"Ashkenaz" in Hebrew refers to Germany, and Ashkenazi Jews are those who originated in Eastern Europe. (Sephardic Jews, by contrast, are from the areas around the Mediterranean Sea, including Portugal, Spain, the Middle East and Northern Africa.) About 80 percent of modern Jews have Ashkenazi ancestry, according to the Hebrew University of Jerusalem. Albert Einstein was an Ashkenazi Jew, as were Gertrude Stein and Carl Sagan. Steven Spielberg and Scarlett Johansson are also Ashkenazi Jews, along with three current members of the U.S. Supreme Court (Ruth Bader Ginsburg, Stephen Breyer and Elena Kagan).

Despite their close ties with Europe, no more than half of their DNA comes from ancient Europeans, the researchers found. The rest of the Ashkenazi genome comes from the Middle East, the researchers reported. This founding group "fused" with the European founding group to create a population of 250 to 420 individuals. Today there are more than 10 million Ashkenazi Jews around the world, including 2.8 million in Israel, according to the Hebrew University of Jerusalem.

Karen Kaplan, Los Angeles Times

The big impact of ride-sharing cabs

A team of mathematicians and engineers has calculated that if taxi riders were willing to share a cab, New York City could reduce the current fleet of 13,500 taxis up to 40 percent, unclogging traffic, conserving fuel and fighting air pollution. The researchers wanted to know whether the principles of the "sharing economy" typified by services like Airbnb, in which people rent out their apartments like hotel rooms, could be applied to taxis.

To study ride-sharing scenarios, the researchers delved into a database compiled by the New York City Taxi and Limousine Commission that included information about each of the 172 million taxi rides in the city in 2011: where the passenger was picked up and dropped off, time of pickup and time of drop-off. Then, applying a computational technique known as shareability networks, they combined trips that were headed in the same direction at the same time. A paper describing the findings was published in Proceedings of the National Academy of Sciences. One of the study's authors said that if self-driving cars ever came to pass, the transformation of cities could be "quite astonishing." In preliminary research not reported in the current paper, the scientists looked at what would happen if most people combined self-driving cars with shared ridership. They concluded that four out of five cars in the city today could become superfluous. The team also looked at a subset of the New York database and determined that ride sharing would provide environmental and cost benefits even in smaller cities.

Kenneth Chang And Joshua A. Krisch, New York Times

Where working women do best

WASHINGTON — The status of working women is strongest in the Northeast, the region home to many of the most-equal states by employment and earnings, according to a national analysis.

Massachusetts had the highest score among states, according to the analysis of four factors conducted by the Institute for Women's Policy Research. All but four of the 10 highest-scoring states — Maryland, Minnesota, Colorado and Virginia — were in the Northeast. West Virginia ranked dead last and, along with Alabama, received an F. Florida, with a C, was ranked 31st.

The four factors analyzed to develop the composite scores were: median annual earnings (for full-time, year-round women workers); the earnings ratio between men and women; the share of women in the workforce and the share of women in managerial or professional jobs.

Niraj Chokshi, Washington Post

Germs spread faster than you think

Viruses can spread from one doorknob to 40 to 60 percent of surfaces in a building in a few hours, according to a study. Researchers put a tracer virus on one or two surfaces in a building at day's beginning. And after two to four hours, it could be detected on a majority of commonly touched surfaces such as light switches, coffee pot handles, phones and computers. "We actually put a virus on a push plate in an office building of 80 people, had three entrances, and within four hours it ended up on over half the people's hands, and it ended up on over half the surfaces that people touched in that building," said University of Arizona researcher Charles Gerba. "What we really learned was the hand is quicker than the sneeze in the spread of disease."

Abby Phillip, Washington Post.

   
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