Study on Cultural Memory Confirms: Chester A. Arthur, We Hardly Knew Ye

By BENEDICT CAREY

The broader significance of the report is that societies collectively forget according to the same formula as, say, a student who has studied a list of words.

Growing Herds of Deer Aren’t Welcome at New York Parks

By LISA W. FODERARO

The influx concerns parks department officials because the animals can destroy a forest understory and chip away at the bark of developing trees.

News Analysis

Obama Builds Environmental Legacy With 1970 Law

By CORAL DAVENPORT

Leaning on the Clean Air Act, President Obama has reshaped environmental policy more than any previous occupant of the White House.

Obama to Introduce Sweeping New Controls on Ozone Emissions

By CORAL DAVENPORT

The regulation would be the latest in a series of E.P.A. controls on air pollution that wafts from smokestacks and tailpipes, and would probably set off a battle among all sides of the issue.

Legal Fight Pits Sellers of Energy Against Buyers

By DIANE CARDWELL and MATTHEW L. WALD

A system under which big consumers shut down elevator banks or a production line at peak hours of electricity demand has been challenged by power producers, who lose their most valuable revenue hours.

Panel Rejects Sternest F.D.A. Warning for Steroid Shots

By SABRINA TAVERNISE

Recommending the toughest federal alert would have signaled to doctors that the risks of use outweighed any potential therapeutic benefit for patients.

Matter

Clues to Bees’ History, Tucked Away in Drawers

By CARL ZIMMER

Scientists are dusting off old insect collections in museums in an effort to learn what has happened to bee populations.

Supreme Court to Hear Challenge to Rules on Mercury From Power Plants

By ADAM LIPTAK and CORAL DAVENPORT

Industry groups, energy companies and 20 states are challenging the E.P.A.'s interpretation of the law and whether the costs of adhering to regulations should be taken into account.

A Lifesaving Transplant for Coral Reefs

By RICHARD MORIN

A quick-grow laboratory technique, called microfragmenting, may make it possible to mass-produce reef-building corals for transplanting onto dead or dying reefs that took centuries to develop.

Art in a Whisky Glass, Neatly Explained

By KENNETH CHANG

After having a Scotch years ago, a photographer saw beauty at the bottom. Then he got interested in the science behind the patterns.

On the Trail of an Ancient Mystery

By JOHN MARKOFF

More than 100 years after it was found, and more than 2,000 years after it was believed to have been built, the Antikythera Mechanism continues to raise questions and provide answers.

Obesity and Its Heart Complications

By ABIGAIL ZUGER, M.D.

Does a girl who enters adolescence with a big woman’s body have a harder time socially than most teenagers? How about a boy whose fat conjures up female stereotypes?

Are Some Professions Less Honest Than Others? Bank on It, Researchers Find

By DOUGLAS QUENQUA

Bankers have gotten a bit of a bad rep over the last decade, owing to a variety of scandals. A new study may not help.

Radiologists Are Reducing the Pain of Uncertainty

By GINA KOLATA

Radiologists are becoming more accessible to patients, but there are questions over whether the two parties will be able to handle dealing with each other when the results of scans are unwelcome.

Observatory

After Acid Rain, Lakes Are Turning to ‘Jelly’

By DOUGLAS QUENQUA

Tiny, jelly-clad crustaceans known as Holopedium are thriving in some Canadian lakes after years of acid rain, threatening the food chain and “jellifying” the waters, biologists say.