Science & TechnologyS


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Uncovering How Cells Cover Gaps

Researchers at the European Molecular Biology Laboratory (EMBL) in Heidelberg, Germany, came a step closer to understanding how cells close gaps not only during embryonic development but also duringwound healing. Their study, published this week in the journal Cell, uncovers a fundamental misconception in the previous explanation for a developmental process called dorsal closure.

Scientists study dorsal closure, which occurs during the development of the fruit fly Drosophila melanogaster, to gain insights into wound healing in humans, as both processes involve closing a gap in the skin by stretching the surrounding epithelial cells over it.

Dorsal closure involves three entities: the cells that fill the gap, called amnioserosa cells, a cable of the protein actin which runs around the gap, and the epithelial cells that eventually stretch over and seal the gap. Until now, scientists believed dorsal closure started when some unknown signal made the amnioserosa cells and the actin cable contract. The actin cable would then act like the drawstring on a purse together with the gradually contracting amnioserosa cells, it would pull the epithelial cells together until the gap was closed.

Telescope

Supernovas Blast Out Hugely Powerful Cosmic Rays

Cassiopeia
© NASAThe supernova remant Cassiopeia-A.
As astronomers have long expected, exploding stars called supernovas can accelerate particles up to almost the speed of light, a new study shows.

The discovery helps explain where the extremely energetic cosmic rays we find near Earth come from.

Cosmic rays are charged particles, mostly protons, that come swooping through space from beyond the solar system. They carry such an energetic punch they can knock out electronics systems on Earth if they manage to make it past our atmosphere.

Until now, scientists couldn't be sure how cosmic rays acquire their energy and speed.

Sherlock

Ancient Well, and Body, Found in Cyprus

Well
© AP PhotoArchaeologists have discovered a water well in Cyprus that was built as long as 10,500 years ago, and the skeleton of a young woman at the bottom of it, an official said Wednesday.
Archaeologists have discovered a water well in Cyprus that was built as long as 10,500 years ago, and the skeleton of a young woman at the bottom of it, an official said Wednesday.

Pavlos Flourentzos, the nation's top antiquities official, said the 16-foot (5-meter) deep cylindrical shaft was found last month at a construction site in Kissonerga, a village near the Mediterranean island nation's southwestern coast.

After the well dried up it apparently was used to dispose trash, and the items found in it included the poorly preserved skeleton of the young woman, animal bone fragments, worked flints, stone beads and pendants from the island's early Neolithic period, Flourentzos said.

Sherlock

Oldest Human Settlement in Aegean Unearthed on Limnos Island

The ruins of the oldest human settlement in the Aegean found so far have been unearthed in archaeological excavations by a team of Greek, Italian and American archaeologists on the island of Limnos, headed by Thessaloniki Aristotle University (AUTH) professor of Prehistoric Archaeology Nikos Efstratiou.

The excavation began in early June and the finds brought to light so far, mainly stone tools of a high quality, are from the Epipaleolithic Period approximately 14,000 years ago. The finds indicate a settlement of hunters, food-collectors and fishermen of the 12th millennium BC.

Until now, it was believed that the oldest human presence in the Aegean had been located in the Archipelagos of the so-called Cyclops Cave on the rocky islet Yioura, north of the island of Alonissos, and at the Maroula site on Kythnos island, dating to circa 8,000 (8th millennium) BC.

Telescope

Eclipse darkens 'Death Star' moon

The Cassini probe has caught its first glimpse of one Saturn moon eclipsing another, as the moon Enceladus passed in front of its neighbour Mimas.

Most of Saturn's moons orbit in the same plane as its rings, along the planet's equator. This arrangement creates frequent alignments, but eclipses are rare because the sun must illuminate this plane almost edge-on in order for moon shadows to be cast in the right direction.


Telescope

Gluttonous black holes power ancient cosmic 'blobs'

Image
© X-ray (NASA/CXC/Durham U/D. Alexander et al.); Optical (NASA/ESA/STScI/IoA/S Chapman et al.); Lyman-alpha Optical (NAOJ/Subaru/Tohoku Univ./T.Hayashino et al.); Infrared (NASA/JPL-Caltech/Durham Univ./J.Geach et al.)Large, glowing blobs of hydrogen gas (yellow) in the early universe seem to be lit by galaxies boasting gluttonous supermassive black holes (blue)
Mysterious blobs of gas dotting the early universe seem to be lit by ravenous black holes at the hearts of massive galaxies, a new study suggests. Further study of the strange clouds could reveal how young galaxies regulate their meals to become the galaxies we see today.

For about a decade, astronomers have puzzled over the power source behind vast reservoirs of glowing hydrogen gas that can span about 500,000 light years across, several times the size of our own Milky Way. These Lyman-alpha "blobs" are named after a wavelength of light released when an electron loses energy in a hydrogen atom.

One idea was that the blobs might be the next meals of growing galaxies. In this scenario, the gas clouds would radiate energy as they were tugged inwards by gravity and cooled down.

But a new study suggests the clouds are actually lit by almost-full galaxies that prevent the gas from falling inwards. Here, supermassive black holes inside the galaxies are thought to be devouring their surroundings, spawning powerful outpourings of energy.

Cult

Mystery cult's temple unearthed in northern Iraq

A temple built by followers of Mithraism, a mystery cult that flourished throughout the Roman Empire from the second to third centuries A.D., has been discovered in Iraq's northern Duhok province.

The temple, which consists of three parts, lies in the Badri Mountains in eastern Duhok, and includes a place for prayer facing the sun, the province's antiquities director, Hassan Ahmed Qassim, said in a statement to the website of President Jalal Talabani's Patriotic Union of Kurdistan party.

Info

QuikScat Finds Tempests Brewing In 'Ordinary' Storms

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© NOAAQuikScat image of a mature North Atlantic extratropical cyclone from December 1, 2004. The color bar in the upper right indicates wind speed in knots. The storm’s hurricane-force winds, located to the south of the center of the low pressure system, are depicted as red wind barbs.
Satellite, Now Entering Its Second Decade, Has Revolutionized Marine Weather Forecasts.

"June is busting out all over," as the song says, and with it, U.S. residents along the Atlantic and Gulf coasts begin to gaze warily toward the ocean, aware that the hurricane season is revving up. In the decade since NASA's QuikScat satellite and its SeaWinds scatterometer launched in June 1999, the satellite has measured the wind speed and wind direction of these powerful storms, providing data that are increasingly used by the National Oceanic and Atmospheric Administration's (NOAA) National Hurricane Center and other world forecasting agencies. The data help scientists detect these storms, understand their wind fields, estimate their intensity and track their movement.

Saturn

Mars Rover Yielding New Clues While Lodged in Martian Soil

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© NASA/JPL-Caltech/Cornell University The soft soil exposed when wheels of NASA's Mars Exploration Rover Spirit dug into a patch of ground dubbed "Troy" exhibit variations in hue visible in this image, in which the colors have been stretched to emphasize the differences.

Spirit used its panoramic camera during the 1,892nd Martian day, or sol, of the rover's mission on Mars (April 29, 2009) to take the three images combined into this composite image. The three images were taken through filters centered at wavelengths of 750 nanometers, 530 nanometers and 430 nanometers. Spirit had become embedded at Troy by about a week later.

The two rocks near the upper right corner of this view are each about 10 centimeters (4 inches) long and 2 to 3 centimeters (1 inch) wide.
Pasadena, Calif. -- NASA's Mars rover Spirit, lodged in Martian soil that is causing traction trouble, is taking advantage of the situation by learning more about the Red Planet's environmental history.

In April, Spirit entered an area composed of three or more layers of soil with differing pastel hues hiding beneath a darker sand blanket. Scientists dubbed the site "Troy." Spirit's rotating wheels dug themselves more than hub deep at the site. The rover team has spent weeks studying Spirit's situation and preparing a simulation of this Martian driving dilemma to test escape maneuvers using an engineering test rover at NASA's Jet Propulsion Laboratory in Pasadena, Calif.

Play

Dinosaurs actually slimmer than we thought

American researchers say they have uncovered a mathematical mistake made by the dinosaur boffinry community, meaning that the weight of live dinos has long been massively overestimated. In a development with devastating consequences for various much-fancied works of fiction, it now appears that in fact the dinosaurs were significantly slenderer than had been thought.

"Paleontologists have for 25 years used a published statistical model to estimate body weight of giant dinosaurs. By re-examining data in the original reference sample, we show that the statistical model is seriously flawed," says Gary Packard of Colorado State University.

According to Packard and his fellow dino-heft experts, the Apatosaurus louisae, for instance - one of the largest of the dinos - was actually far more svelte than had been thought, its weight having been overestimated by no less than 20 tonnes. The Giraffatitan (aka Brachiosaurus) was actually 16 tonnes less portly than formerly estimated.