Black holes really are holes – objects without a surface – say Drs Christine Done and Marek Gierlinski in a paper accepted for publication in the Monthly Notices of the Royal Astronomical Society. Having an “event horizon” rather than a surface is the property that makes something a black hole but, by definition, it’s impossible ever to see one directly. However, these new results give direct evidence of the existence of such holes in spacetime.

Drs Done and Gierlinski set out to track

People who live in neighborhoods where stores, schools and homes are within walking or cycling distance from each other make almost twice as many weekly trips on foot as residents of less “walkable” neighborhoods, according to new research.

And all that car-free traveling can add up to better health: One or two extra walking trips a week can burn off enough calories to drop nearly two pounds in a year, which is about how much weight American adults gain annually.

If a large propo

In a new study published in the April 1, 2003 issue of Genes and Development, scientists at University Health Network’s Advanced Medical Discovery Institute (AMDI)/Ontario Cancer Institute (OCI) have shown that a molecule called caspase-8 plays a key role in the immune system response, by controlling how T-cells are activated to respond to infections.

T-cells are white blood cells that recognize and fight off viruses and bacteria. When T-cells encounter these foreign invaders they build up

The first clinical trials of a new type of cancer treatment that releases the “brakes” on immune cells indicate that this approach enhances attacks on tumors while sparing the body’s own tissue.

The results of the phase I clinical trials of cytotoxic T-lymphocyte-associated antigen 4 blockade therapy were published online on April 1, 2003, in the Early Edition of the Proceedings of the National Academy of Sciences. The researchers involved in the study included James Allison, a Howard Hughe

Just as vegetables are essential to balancing the human diet, the inclusion of vegetation may be equally essential to balancing Earth’s climate models.

Scientists at MIT who were trying to create accurate models of climate change in the southern portion of the Sahara desert found that including a realistic component of vegetation growth and decay was absolutely essential. Without including the vegetation as a variable (rather than a fixed parameter), the models were not able to show the regi

Though Einstein put his foot down and demanded that nothing can move faster than light, a new device developed at the University of Rochester may let you outpace a beam by putting your foot down on the gas pedal. At 127 miles per hour, the light in the new device travels more than 5 million times slower than normal as it passes through a ruby just a few centimeters long.

Instead of the complex, room-filling mechanisms previously used to slow light, the new apparatus is small and, in the wor