Science & TechnologyS


Magnify

Protein That Keeps Stem Cells Poised for Action Identified


ScienceDaily
Mon, 28 Dec 2009 00:00 UTC
Like a child awaiting the arrival of Christmas, embryonic stem cells exist in a state of permanent anticipation. They must balance the ability to quickly become more specialized cell types with the cellular chaos that could occur should they act too early (stop shaking those presents, kids!). Researchers at the Stanford University School of Medicine have now identified a critical component, called Jarid2, of this delicate balancing act -- one that both recruits other regulatory proteins to genes important in differentiation and also modulates their activity to keep them in a state of ongoing readiness.

"Understanding how only the relevant genes are targeted and remain poised for action is a hot topic in embryonic stem cell research," said Joanna Wysocka, PhD, assistant professor of developmental biology and of chemical and systems biology. "Our results shed light on both these questions." Wysocka is the lead author of the research, which will be published in the Dec. 24 issue of Cell.

Jarid2 works through a protein complex called PRC2, for Polycomb Repressive Complex 2. PRCs keep genes quiet by modifying DNA packaging proteins called histones. It's not quite tying a string around a brown paper package, but the concept is similar: Wrapping DNA up neatly around the histones helps it all fit in the tiny space and keeps it out of commission until the appropriate time. That's because, when wrapped, genes can't be converted into proteins to do the work of the cell. PRC2 adds a molecular "Do not open until Christmas" tag to ensure the DNA stays wrapped until it's needed.
Read More...
Satellite

Voyager Makes an Interstellar Discovery

Dr. Tony Phillips
Science@NASA
Wed, 23 Dec 2009 20:24 UTC
Image
© The American Museum of Natural HistoryVoyager flies through the outer bounds of the heliosphere en route to interstellar space. A strong magnetic field reported by Opher et al in the Dec. 24, 2009, issue of Nature is delineated in yellow.
The solar system is passing through an interstellar cloud that physics says should not exist. In the Dec. 24th issue of Nature, a team of scientists reveal how NASA's Voyager spacecraft have solved the mystery.

"Using data from Voyager, we have discovered a strong magnetic field just outside the solar system," explains lead author Merav Opher, a NASA Heliophysics Guest Investigator from George Mason University. "This magnetic field holds the interstellar cloud together and solves the long-standing puzzle of how it can exist at all."

The discovery has implications for the future when the solar system will eventually bump into other, similar clouds in our arm of the Milky Way galaxy.
Read More...
Info

Acacia plant controls ants with chemical

Victoria Gill
British Broadcasting Corporation
Sun, 27 Dec 2009 20:04 UTC
Image
Plants have systems for keeping their six-legged inhabitants in check
In Africa and in the tropics, armies of tiny creatures make the twisting stems of acacia plants their homes.

Aggressive, stinging ants feed on the sugary nectar the plant provides and live in nests protected by its thick bark.

This is the world of "ant guards".

The acacias might appear overrun by them, but the plants have the ants wrapped around their little stems.

These same plants that provide shelter and produce nourishing nectar to feed the insects also make chemicals that send them into a defensive frenzy, forcing them into retreat.

Nigel Raine, a scientist working at Royal Holloway, University of London in the UK has studied this plant-ant relationship.
Read More...
Evil Rays

Yellowstone "supervolcano" soon to be among the best monitored hot spots in the world


Associated Press
Sat, 26 Dec 2009 19:29 UTC
The Yellowstone "supervolcano" will soon be among the best monitored hot spots in the world with the installation of new earthquake monitoring equipment.

The park is getting 10 new seismic monitoring stations over the next two years, which will be used jointly at the observatory by the U.S. Geological Survey, Yellowstone National Park and the University of Utah.

Funding for the project will come from a portion of $950,000 in Recovery Act money given to the observatory.
Read More...
Sherlock

Threshold to Cleopatra's Mausoleum Discovered Off Alexandria Coast

Helena Smith
The Guardian
Wed, 23 Dec 2009 17:10 UTC
Image
© Hulton Archive/Silver Screen Collection/Getty ImagesRichard Burton and Elizabeth Taylor in Antony and Cleopatra.
They were one of the world's most famous couples, who lived lives of power and glory - but who spent their last hours in despair and confusion. Now, more than 2,000 years since Antony and Cleopatra walked the earth, historians believe they may finally have solved the riddle of their last hours together.

A team of Greek marine archaeologists who have spent years conducting underwater excavations off the coast of Alexandria in Egypt have unearthed a giant granite threshold to a door that they believe was once the entrance to a magnificent mausoleum that Cleopatra VII, queen of the Egyptians, had built for herself shortly before her death.

They believe the 15-tonne antiquity would have held a seven metre-high door so heavy that it would have prevented the queen from consoling her Roman lover before he died, reputedly in 30BC.

"As soon as I saw it, I thought we are in the presence of a very special piece of a very special door," Harry Tzalas, the historian who heads the Greek mission, said. "There was no way that such a heavy piece, with fittings for double hinges and double doors, could have moved with the waves so there was no doubt in my mind that it belonged to the mausoleum. Like Macedonian tomb doors, when it closed, it closed for good."
Read More...
Sherlock

Bamiyan Buddha-Like Sculptures Discovered in Ladakh


India Gazette
Sun, 27 Dec 2009 10:00 UTC
Ancient rock-cut sculptures of the Buddha, resembling the Bamiyan Buddhas of Afghanistan, have been discovered in the Zanskar area in Ladakh region.

The discovery of the 1,400-year-old sculptures was made by the archives, archaeology and museums department of Jammu and Kashmir, an official said Sunday.

The Bamiyan Buddhas were destroyed by the Taliban.

The discovery has delighted archaeologists who believe the site in Kargil district could prove a tourist attraction.

The discovery is being publicised to get tourists, especially from Japan and Taiwan to the area. Kargil is 220 km north of Srinagar.
Read More...
Sun

Solar Activity Intensifies


Space Weather
Sun, 27 Dec 2009 18:17 UTC
2009 is ending with a flurry of sunspots. The latest is sunspot 1039, which formed yesterday and is now crackling with low-level solar flares. Cai-Uso Wohler sends this picture of a B-class eruption from his backyard observatory in Bispingen, Germany:

Image
© Cai-Uso Wohler
So far, 65% of the days in December have brought sunspots--a sharp increase in percentages compared to earlier months of 2009 when sunspots were surpassingly rare. All six of December's sunspot groups have been members of new Solar Cycle 24. These numbers could herald the sun's awakening from the deepest solar minimum in nearly a century and a livelier sun in 2010. Stay tuned.
Read More...
Meteor

Reality matches Dreaming story

Deborah Smith
Sydney Morning Herald
Sun, 27 Dec 2009 18:01 UTC
An Aboriginal dreaming story about a star crashing to Earth with a noise like thunder has led to the discovery of an ancient meteorite crater in central Australia.

A Sydney astronomer, Duane Hamacher, found the bowl-shaped crater in Palm Valley, about 130 kilometres south-west of Alice Springs, by searching on Google Earth.

He was inspired to look there after learning of traditional stories told by the local Arrernte people about a star that had fallen into a waterhole called Puka in the valley.

Mr Hamacher, a PhD candidate at Macquarie University, said that reality matching the Dreaming story could be a case of pure chance.

''But if so, it's an incredible coincidence,'' he said.

He is part of a team, led by a CSIRO astronomer, Ray Norris, that is exploring the possibility that Aborigines were the world's first astronomers.

Traditional Aboriginal wisdom about the heavens was impressive, Mr Hamacher said.
Read More...
Blackbox

Will a neutralino steal Higgs's thunder?

Anil Ananthaswamy
New Scientist
Sun, 27 Dec 2009 15:50 UTC
Image
© ATLAS/CERNHaving a smashing time in 2010
The world's biggest experiment is primed to answer one of the universe's biggest questions: what is the origin of mass? But an unexpected particle could yet steal the show.

In CERN's 27-kilometre tunnel near Geneva, Switzerland, the Large Hadron Collider will start smashing high-energy protons head-on in 2010. The shrapnel is expected to reveal the presence of the one missing member of the tribe of particles predicted by the standard model of physics: the Higgs boson, which is thought to endow elementary particles with mass. But the Higgs is unlikely to emerge during the year, as its telltale traces will be hard to spot amidst the complex debris left by the proton collisions.

Instead a different particle might hog the headlines: the neutralino. No one has ever seen one, but it is predicted by the theory of supersymmetry, which fixes many problems that plague the standard model. Supersymmetry doubles the number of elementary particles, adding one heavier super-partner for each standard-model particle.
Read More...
Better Earth

Journey to the bottom of the sea

Linda Geddes
New Scientist
Fri, 25 Dec 2009 15:34 UTC
Image
© NOC Southampton25 leagues under the sea
Captain Nemo had it easy. When robotic submarines are sent 6000 metres to the bottom of an ocean-ridge rift in March, they will face furiously hot temperatures, pressure that gives oil the consistency of treacle, and rugged cliffs that plunge into the abyss. The pay-off, for an international collaboration of researchers called InterRidge, should be an insight into an unexplored world.

The Cayman trough is a 100-kilometre-long rift in the seabed between Jamaica and the Cayman Islands where the ocean floor is slowly pulling apart and new lava seeps up to fill the gap - a so-called ocean ridge. Such ridges are home to hydrothermal vents, and while vents at 3800 metres below the surface have been explored before, InterRidge plans to visit some of the world's deepest, which lie around 6000 metres down. At this depth, water doesn't boil until it reaches 500 °C.
Read More...