Therapy flags DNA typos to rev cancer-fighting T cells

Mutations that prevent cells from spell-checking their DNA may make cancer cells vulnerable to immunotherapies, a new study suggests. A type of immune therapy known as PD-1 blockade controlled cancer in 77 percent of patients with defects in DNA mismatch repair — the system cells use to spell-check and fix errors in DNA (SN Online: […]

Earth’s dry zones support a surprising number of trees

Earth’s dry regions have more trees than once thought — a hopeful note in the fight against climate change. An analysis of high-resolution satellite imagery reveals that drylands globally have 40 to 47 percent more tree cover (an extra 467 million hectares) than reported in earlier estimates. An international team of researchers used Google Earth […]

Radioactive substances leave electron ‘fingerprints’ behind

Walls can’t talk, but scientists can now read stories written in their subatomic particles. And that could make it harder to store radioactive material in secret. Nuclear radiation rearranges the electrons in insulators such as brick, glass and porcelain. So comparing the positions of electrons in atoms at different spots on walls, windows and floors […]

Evidence mounts for an ocean on early Venus

Venus may have been all wet early on. New simulations suggest that if the now-hellish planet had just the right amount of cloud cover, carbon dioxide and water to start with, Venus could have formed an ocean. The result, published online July 18 in the Journal of Geophysical Research: Planets, provides a new clue to […]

Quantum video chat links scientists on two different continents

Hackers, take notice: Ultrasecure quantum video chats are now possible across the globe. In a demonstration of the world’s first intercontinental quantum link, scientists held a long-distance videoconference on September 29 between Austria and China. To secure the communication, a Chinese satellite distributed a quantum key, a secret string of numbers used to encrypt the […]

Sharp stones found in India signal surprisingly early toolmaking advances

Stone-tool makers in what’s now India redesigned their products in a revolutionary way much earlier than previously thought. Excavated stone artifacts document a gradual shift from larger, handheld cutting implements to smaller pieces of sharpened stone, known as Middle Paleolithic tools, by around 385,000 years ago, researchers say. That shift mirrors a similar change seen […]

New laser emits a more stable, energy-efficient light beam

A new type of laser is modeled after an exotic class of materials called topological insulators. And it’s proving more reliable and energy-efficient than its conventional counterparts, paving the way for possible use in quantum communication and next-generation electronics. The device, described online February 1 in Science, is composed of a grid of semiconductor rings […]

A single atom can gauge teensy electromagnetic forces

ZeptonewtonZEP-toe-new-ton n.A unit of force equal to one billionth of a trillionth of a newton. An itty-bitty object can be used to suss out teeny-weeny forces. Scientists used an atom of the element ytterbium to sense an electromagnetic force smaller than 100 zeptonewtons, researchers report online March 23 in Science Advances. That’s less than 0.0000000000000000001 […]

Why cracking your knuckles can be so noisy

“Pop” goes the knuckle — but why? Scientists disagree over why cracking your knuckles makes noise. Now, a new mathematical explanation suggests the sound results from the partial collapse of tiny gas bubbles in the joints’ fluid. Most explanations of knuckle noise involve bubbles, which form under the low pressures induced by finger manipulations that […]