Science & TechnologyS

Blackbox

Will a neutralino steal Higgs's thunder?

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© 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.

Better Earth

Journey to the bottom of the sea

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© 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 ยฐC.

Chalkboard

Secrets of the Brain: Researchers Decipher Parts of the Neuronal Code

The human brain works at a far higher level of complexity than previously thought. What has been given little attention up to now in the information processing of neuronal circuits has been the time factor. "Liquid computing" -- a new theory about how these complex networks of nerve cells actually work from computer scientists at Graz University of Technology -- has just passed its first test.

An interdisciplinary co-operation with neuroscientists from the Max-Planck Institute (MPI) for Brain Research in Frankfurt managed to show that early processing stages in the brain pool information over a longer period. For the evaluation of the experiments, the researchers also had to crack the neuronal code. The scientists published the new findings of their research work, which is funded by the Austrian Science Fund FWF in Austria, in the current edition of PLoS Biology.

The idea that the brain processes information step by step appears out of date. "The human brain does not work on the principle of the assembly line. In processing information, it is possible that time is treated much more flexibly than previously thought," explained Wolfgang Maass, head of the Institute for Theoretical Computer Science at Graz University of Technology. Like waves on a pool

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Magnetic Field Measurements of the Human Heart at Room Temperature

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© Physikalisch-Technische Bundesanstalt (PTB)The "most magnetically quiet room on earth" is on the PTB site in Berlin.
The "magnetically best shielded room on earth" has the size of an apartment block and is located on the site of the Physikalisch-Technische Bundesanstalt (PTB), Institute Berlin. Magnetic fields such as that of the earth are kept out here as effective as nowhere else. Such ideal conditions allow to measure the tiny magnetic fields of, e.g., the human heart.

This was the motivation for the American National Institute of Standards and Technology (NIST) to ask PTB to jointly test a newly developed optical magnetic field sensor. It is based on a physical principle very different from SQUIDs, which are usually applied for biomagnetic field measurements. The optical sensor does not need advanced cooling and has the size of a lump of sugar. A high-quality measurement of the human heart signal was demonstrated using this optical sensor. The sensor's suitability was thus proven for biomagnetic measurements in the picotesla range. In future magnetocardiographic measurement devices -- to be used as a supplement or an alternative to the ECG -- could become simpler and less expensive.

Up until now one had to cool as much as one could for biomagnetic measurements. This was necessary as SQUIDs, superconducting quantum interference devices, work optimally at -269 degrees Celsius and can only then fulfil their purpose of measuring tiny magnetic fields. SQUIDs are the best suited sensors to record the magnetic fields arising during the electrical activity of the human heart. A magnetocardiogram (MCG) can be compiled supplementing a conventional electrocardiogram (ECG). (The same applies to the magnetoencephalogram, MEG, which is a recording of the magnetic field of the brain.) Yet to use SQUIDs requires well-shielded rooms and complicated cooling systems. The latter might become obsolete in the future if the optical magnetometer developed by NIST continues to fulfil expectations.

Sherlock

First Jesus-Era House Discovered in Nazareth

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© AP Photos/Dan BaliltyReverend Jack Karam, left, stands near Israel's Antiquities Authority workers at the excavation site of the remains of the first dwelling in Nazareth, Israel that can be dated back to the time of Jesus.
Just in time for Christmas, archaeologists on Monday unveiled what may have been the home of one of Jesus' childhood neighbors. The humble dwelling is the first dating to the era of Jesus to be discovered in Nazareth, then a hamlet of around 50 impoverished Jewish families where Jesus spent his boyhood.

Archaeologists and present-day residents of Nazareth imagined Jesus as a youngster, playing with other children in the isolated village, not far from the spot where the Archangel Gabriel revealed to Mary that she would give birth to the boy.

Today the ornate Basilica of the Annunciation marks that spot, and Nazareth is the largest Arab city in northern Israel, with about 65,000 residents. Muslims now outnumber Christians two to one in the noisy, crowded city.

The archaeological find shows how different it was 2000 years ago: There were no Christians or Muslims, the Jewish Temple stood in Jerusalem and tiny Nazareth stood near a battleground between Roman rulers and Jewish guerrillas.

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How the Brain Encodes Memories at a Cellular Level

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© Sourav BanerjeeThis is a neuron.
Scientists at UC Santa Barbara have made a major discovery in how the brain encodes memories. The finding, published in the December 24 issue of the journal Neuron, could eventually lead to the development of new drugs to aid memory.

The team of scientists is the first to uncover a central process in encoding memories that occurs at the level of the synapse, where neurons connect with each other.

"When we learn new things, when we store memories, there are a number of things that have to happen," said senior author Kenneth S. Kosik, co-director and Harriman Chair in Neuroscience Research, at UCSB's Neuroscience Research Institute. Kosik is a leading researcher in the area of Alzheimer's disease.

"One of the most important processes is that the synapses -- which cement those memories into place -- have to be strengthened," said Kosik. "In strengthening a synapse you build a connection, and certain synapses are encoding a memory. Those synapses have to be strengthened so that memory is in place and stays there. Strengthening synapses is a very important part of learning. What we have found appears to be one part of how that happens."

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Earth on Track for Epic Die-Off, Scientists Say

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© Mauricio Anton/UCLAA reconstructed scene in the Pleistocene of western North America, showing a group of three sabertooth cats (Smilodon fatalis).
If the course of human history is any model, then the wheels are already turning on Earth's sixth mass extinction, thanks to habitat destruction, pollution and now global warming, a scientific analysis of millions of years of data revealed Friday.

The study of the fossil and archaeological record over the past 30 million years by UC Berkeley and Penn State University researchers shows that between 15 and 42 percent of the mammals in North America disappeared after humans arrived.

That means North American mammals are well on the way - perhaps as much as half way - to a level of extinction comparable to other epic die-offs, like the one that wiped out the dinosaurs.

Anthony Barnosky, a UC Berkeley professor of integrative biology and co-author of the study, said the most dramatic human-caused impacts on the ecosystem have occurred in the last century.

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Chemical Energy Influences Tiny Vibrations of Red Blood Cell Membranes

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© Alex Jerez, YongKeun Park, Gabriel Popescu, and Subra SureshPictured is an artist's rendering of human red blood cell.
Much like a tightly wound drum, red blood cells are in perpetual vibration. Those vibrations help the cells maintain their characteristic flattened oval or disc shape, which is critical to their ability to deform as they traverse blood vessels in the body to deliver oxygen to tissues.

Blood disorders such as malaria, sickle cell anemia and spherocytosis interfere with those vibrations, so a better understanding of the vibrations could help researchers develop treatments for those diseases. However, the vibrations are nearly impossible to study because their amplitude is so tiny (nanometer, or billionth of a meter, scale), and they occur in just milliseconds.

A year ago, a team led by MIT Dean of Engineering Subra Suresh and Physics Professor Michael Feld, director of MIT's George R. Harrison Spectroscopy Laboratory, reported the first whole-cell glimpse of these membrane fluctuations. Now, in a paper appearing in the Proceedings of the National Academy of Sciences, they present conclusive evidence that the vibrations require energy input from ATP (adenosine triphosphate), a chemical cells use to store and transfer energy.

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Fight Infection by Disturbing How Bacteria Communicate

Researchers from the University of Groningen have clarified the structure of an enzyme that disturbs the communication processes between bacteria. By doing so they have laid the foundations for a new method of tackling bacterial infections such as cystic fibrosis. An article on the structure and function of the so-called quorum-quenching acylase was published on 21 December 2009 in the online edition of the Proceedings of the National Academy of Sciences (PNAS).

Although bacteria are simple single-celled organisms, they are capable of communicating with each other. Bacteria talk to each other by exchanging tiny hormone-like signal molecules. By means of this process of 'quorum sensing', the activities of a large group of bacteria are synchronized. Thus bacteria can adapt quickly to changes in their environment such as the running out of nutrients or the arrival of rival microorganisms.

The production of factors that determine the virulence of a bacterium is also controlled by these signal molecules. This enables bacteria to remain invisible to the immune system in the early stages of infection. As soon as the group of informed bacteria -- the quorum -- is sufficiently large, the attack on the infected host is initiated by starting up the production of toxins and other virulence factors.

Telescope

Herschel Space Telescope Uncovers Sources of Cosmic Infrared Background

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© Max Planck Institute for Extraterrestrial PhysicsHerschel-PACS images of the โ€˜GOODS-Nโ€™ field in the constellation of Ursa Major at far-infrared wavelengths of 100 and 160micrometres.
A weak cosmic infrared radiation field that reaches Earth from all directions contains not yet deciphered messages about the evolution of galaxies. Using first observations with the PACS Instrument on board ESA's Herschel Space Telescope, scientists from the Max Planck Institute for Extraterrestrial Physics and other institutions have for the first time resolved more than half of this radiation into its constituting sources. Observations with Herschel open the road towards understanding the properties of these galaxies, and trace the dusty side of galaxy evolution.

In the mid 1990's, scientists analyzing data from NASA's COBE spacecraft discovered faint radiation in the far-infrared part of the electromagnetic spectrum that reaches earth with the same intensity from all directions in space. Immediately, they suspected it to be the aggregate emission of many distant galaxies in the early universe, releasing the same amount of energy in the far-infrared as reaches us in visible light from similarly distant galaxies.

Whereas visible light tells us about the stars in galaxies, the far-infrared is emitted by cold dust that is hiding the newly formed stars. Identifying these surprisingly numerous dusty galaxies has proven difficult, though. Space telescopes are needed to detect far-infrared emission, because it is absorbed by the Earth's atmosphere. Previous infrared space telescopes have detected far-infrared light from only the brightest of the galaxies forming this cosmic background. To glean any information about the fainter objects, astronomers had to rely on indirect evidence based on shorter wavelength radiation.