Sea Urchin Hold Secret of Biomineralization

Used to crush food, for structural support and for defense, the materials of which shells, teeth and bones are composed are the strongest and most durable in the animal world, and scientists and engineers have long sought to mimic them.

A new study describes how the lowly sea urchin transforms calcium carbonate — the same material that forms "lime" deposits in pipes and boilers — into the crystals that make up the flint-hard shells and spines of marine animals. The mechanism, the authors write, could "well represent a common strategy in biomineralization."

The sea urchin larval spicule is a model system for biominerals, and the first one in which the amorphous calcium carbonate precursor was discovered in 1997 by the same Israeli group co-authoring the current PNAS paper. A similar amorphous-to-crystalline transition has since been observed in adult sea urchin spines, in mollusk shells, in zebra fish bones and in tooth enamel. The resulting biominerals are extraordinarily hard and fracture resistant, compared to the minerals of which they are made.

"The amorphous minerals are deposited and they are completely disordered," Gilbert explains. "So the question we addressed is 'how does crystallinity propagate through the amorphous mineral?'"

“We found that at 40-100 nanometer amorphous calcium carbonate particles aggregate into the final morphology. One starts converting to crystalline calcite, then another immediately adjacent converts as well, and another, and so on in a three-dimensional domino effect. The pattern of crystallinity, however, is far from straight. It resembles a random walk, or a fractal, like lightning in the sky or water percolating through a porous medium," explains Gilbert.

Vampire Moth Discovered

From National Geographic News:

Only slight variations in wing patterns distinguish the Russian population from a widely distributed moth species, Calyptra thalictri, in central and southern Europe known to feed only on fruit.

When the Russian moths were experimentally offered human hands this summer, the insects drilled their hook-and-barb-lined tongues under the skin and sucked blood.
Entomologist Jennifer Zaspel at the University of Florida in Gainesville said the discovery suggests the moth population could be on an "evolutionary trajectory" away from other C. thalictri populations. This is the second population of vampire moths Zaspel and her team have found. They discovered the first in Russia in 2006.

"Based on geography, based on behavior, and based on a phenotypic variation we saw in the wing pattern, we can speculate that this represents something different, something new," Zaspel said.

Robot Ants To Colonize Mars

The first inhabitants of Mars might not be human in form at all, but rather swarms of tiny robots.

European researchers are developing tiny autonomous robots that can co-operate to perform different tasks, much like termites, ants or bees forage collaboratively for food, build nests and work together for the greater good of the colony.

Working in the I-SWARM project, the team created a 100-strong posse of centimetre-scale robots and made considerable progress toward building swarms of ant-sized micro-bots. Several of the researchers have since gone on to work on creating swarms of robots that are able to reconfigure themselves and assemble autonomously into larger robots in order to perform different tasks.

Just as ants may observe what other ants nearby are doing, follow a specific individual, or leave behind a chemical trail in order to transmit information to the colony, the I-SWARM team’s robots are able to communicate with each other and sense their environment. The result is a kind of collective perception.

The robots use infrared to communicate, with each signalling another close by until the entire swarm is informed. When one encounters an obstacle, for example, it would signal others to encircle it and help move it out of the way.

Planet exploration and colonisation are just some of a seemingly endless range of potential applications for robots that can work together, adjusting their duties depending on the obstacles they face, changes in their environment and the swarm’s needs.

Simple, mass production would ensure that the robots are relatively cheap to manufacture. Researchers would therefore not have to worry if one gets lost in the Martian soil. link

I-SWARM robots in action:

Secret of Death Protein Unlocked

Scientists at Dana-Farber Cancer Institute have identified a previously undetected trigger point on a naturally occurring "death protein" that helps the body get rid of unwanted or diseased cells. They say it may be possible to exploit the newly found trigger as a target for designer drugs that would treat cancer by forcing malignant cells to commit suicide.

The researchers fashioned a peptide (a protein subunit) that precisely matched the shape of the newly found trigger site on the killer protein, which lies dormant in the cell's interior until activated by cellular stress. When the peptide docked into the binding site, BAX was spurred into assassin mode. The activated BAX proteins flocked to the cell's power plants, the mitochondria, where they poked holes in the mitochondria's membranes, killing the cells. This process is called apoptosis, or programmed cell death.

"We identified a switch that turns BAX on, and we believe this discovery can be used to develop drugs that turn on or turn off cell death in human disease by targeting BAX," said Walensky, who is also an assistant professor of pediatrics at Harvard Medical School.

Ref: BAX activation is initiated at a novel interaction site. 2008. Evripidis Gavathiotis et al. Nature 455: 1076-1081.

Tomb of the Blind Dead

Single Species Ecosystem At The Earth's Core

The first ecosystem ever found having only a single biological species has been discovered 2.8 km beneath the surface of the earth in the Mponeng gold mine near Johannesburg, South Africa. There the rod-shaped bacterium Desulforudis audaxviator exists in complete isolation, total darkness, a lack of oxygen, and 60-degree-Celsius heat.

D. audaxviator survives in a habitat where it gets its energy not from the sun but from hydrogen and sulfate produced by the radioactive decay of uranium. Living alone, D. audaxviator must build its organic molecules by itself out of water, inorganic carbon, and nitrogen from ammonia in the surrounding rocks and fluid. During its long journey to the extreme depths, evolution has equipped the versatile spelunker with genes – many of them shared with archaea, members of a separate domain of life unrelated to bacteria – that allow it to cope with a range of different conditions, including the ability to fix nitrogen directly from elemental nitrogen in the environment.



It’s genome contains everything needed for the organism to sustain an independent existence and reproduce, including the ability to incorporate the elements necessary for life from inorganic sources, move freely, and protect itself from viruses, harsh conditions, and nutrient-poor periods by becoming a spore.

Dylan Chivian coined the name “audaxviato” from a phrase found in Jules Verne's Journey to the Center of the Earth, in a message – "Conveniently in Latin," says Chivian -- deciphered by Verne's protagonist, Professor Lidenbrock, which reads in part, "descende, Audax viator, et terrestre centrum attinges." It means "descend, Bold traveler, and attain the center of the Earth." link

Environmental genomics reveals a single-species ecosystem deep within the Earth. D. Chivian et al.. 2008. Science 322.

Mighty Peking Man

"At first glance, the Shaw Brothers' 1977 demi-epic Mighty Peking Man might seem like the usual substandard big-monkey-on-the-loose shenanigans. But truly, this is the greatest reworking of the archetypal man-woman-ape love triangle since the original King Kong threw down the gauntlet in 1933." from StompTokyo.com.

The High Pitched Sound of Love

Black Canary © DC Comics

A pair of scientists at the University of California in Los Angeles (UCLA) asked 69 women to make voice recordings when they were at high and low fertility points in their menstrual cycle. The closer a woman was to ovulation, the more she raised her pitch, the investigators found.

The increase in tone was only slight -- it wasn't Minnie Mouse on helium -- but the peaks were enough to be picked up by the voice decoder and presumably by the male ear, as well. The difference was the greatest on the two days preceding ovulation, when fertility within the cycle is the highest.

Curiously, this distinction only occurred when the volunteer, among the sentences she was asked to speak, introduced herself: "Hello, I'm a student at UCLA."

The scientists suggest the pitch change happens because men are lured to a more "feminine" voice in a woman -- and women respond to the instinct.

Sexual signals and reproductive fitness are strongly associated with voice, which is why women are often drawn to men with the husky voice of the supposed alpha male.

"Men prefer higher pitch relative to lower pitch in the same women, and these judgements are affected by cues of social interest in the speech," say the duo, Greg Bryant and Martie Haselton of the university's Center for Behavior, Evolution and Culture.

Previous research has found changes to body scent, an increase in flirtation, a shift towards more fashionable dress styles and a preference for more "masculine" men when women are in mid-cycle. Last year, investigators found that lap dancers earned more tips when they were fertile.

Conversely, a vocal shift towards hoarseness has been found at the time of menstruation. link

Giant Tornadoes Seen Erupting From the Sun

Image courtesy NASA

A solar storm on the sun's surface was shown to twist, like a tornado does on Earth, in images from NASA's STEREO satellite taken on April 9, 2008.

This twisting also occurs in solar jets, which produce tornado-like events close to the sun's poles, new satellite data has found. "These solar tornadoes are almost a thousand times faster than a terrestrial tornado and are very big," said Spiros Patsourakos, a researcher at George Mason University.

That twist comes from the sun's magnetic field, said Etienne Pariat, also of George Mason University.

"The magnetic field lines act like a spring, which expands and jumps outward," said Pariat, who has used computer simulations to model the forces producing the jets. The forces originate in the solar interior, he added, where the sun's rotation twists the magnetic field. "But the twist cannot be stored, so it must be ejected."

TV Tornado © 1967 World Distributors

Scientists have known since the 1990s that jets of gas wider than North America were erupting from the sun's poles, but it is only now that they discovered these jets are rotating. Advanced viewing technologies have enabled scientists to study these phenomena in unprecedented clarity. link

Tornado Twins © DC Comics

Gahan Wilson Gets "Old"

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Gahan Wilson's Strange Beliefs of Children

© Gahan Wilson
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Barren Seafloor Teeming With Microbial Life

Once considered a barren plain with the odd hydrothermal vent, the seafloor appears to be teeming with microbial life.

“A 60,000 kilometer seam of basalt is exposed along the mid-ocean ridge spreading system, representing potentially the largest surface area for microbes to colonize on Earth,” said USC geomicrobiologist Katrina Edwards.

The scientists found higher microbial diversity on the rocks compared with other vibrant systems, such as those found at hydrothermal vents. Even compared with the microbial diversity of farm soil—viewed by many as the richest—diversity on the basalt is statistically equivalent.

These findings raise the question of where these bacteria find their energy.

With evidence that the oceanic crust supports more bacteria compared with overlying water, the scientists hypothesized that reactions with the rocks themselves might offer fuel for life. Back in the lab, they calculated how much biomass could theoretically be supported by chemical reactions with the basalt. “It was completely consistent,” Edwards said.

This lends support to the idea that bacteria survive on energy from the crust, a process that could affect our knowledge about the deep-sea carbon cycle and even evolution.

For example, many scientists believe that shallow water, not deep water, cradled the planet’s first life. They reason that the dark carbon-poor depths appear to offer little energy, and rich environments like hydrothermal vents are relatively sparse.

But the newfound abundance of seafloor microbes makes it theoretically possible that early life thrived—and maybe even began—on the seafloor. “Some might even favor the deep ocean for the emergence of life since it was a bastion of stability compared with the surface, which was constantly being blasted by comets and other objects,” Edwards suggested. link

Abundance and diversity of microbial life in ocean crust. 2008. Cara M. Santelli, et al. Nature 453: 653-656.

Today In History: Patent for “The Brain That Wouldn’t Die”

In 1987, a patent for "keeping a head alive" was issued to Chet Fleming (U.S. No. 4,666,425). A cabinet provides physical and biochemical support for an animal's head severed from its body.

Oxygenated blood and nutrients are circulated by means of tubes connected to arteries and veins that emerge from the neck. A series of processing components removes carbon dioxide and add oxygen to the blood. If desired, waste products and other metabolites may be removed from the blood, and nutrients, therapeutic or experimental drugs, anti-coagulants, and other substances may be added to the blood.

After being thoroughly tested on research animals, the patent suggests it might also be used on humans suffering from various terminal illnesses. From Today In Science History.

The Cadmus Seed

From Shocking Tales Digest Magazine #1, October, 1981, comes a cautionary tale of genetic cloning by Jack Kirby. Not sure where it was originally published.

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XMM-Newton Discovers Part of Missing Universe

ESA’s orbiting X-ray observatory XMM-Newton has been used by a team of international astronomers to uncover part of the missing matter in the universe.

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10 years ago, scientists predicted that about half of the missing ‘ordinary’ or normal matter made of atoms exists in the form of low-density gas, filling vast spaces between galaxies.

All the matter in the universe is distributed in a web-like structure. At dense nodes of the cosmic web are clusters of galaxies, the largest objects in the universe. Astronomers suspected that the low-density gas permeates the filaments of the web.

The low density of the gas hampered many attempts to detect it in the past. With XMM-Newton’s high sensitivity, astronomers have discovered its hottest parts. The discovery will help them understand the evolution of the cosmic web.

Only about 5% of our universe is made of normal matter as we know it, consisting of protons and neutrons, or baryons, which along with electrons, form the building blocks of ordinary matter. The rest of our universe is composed of elusive dark matter (23%) and dark energy (72%).

Small as the percentage might be, half of the ordinary baryonic matter is unaccounted for. All the stars, galaxies and gas observable in the universe account for less than a half of all the baryons that should be around.

Astronomers using XMM-Newton were observing a pair of galaxy clusters, Abell 222 and Abell 223, situated at a distance of 2300 million light-years from Earth, when the images and spectra of the system revealed a bridge of hot gas connecting the clusters.

From Physorg News.

The Science Behind Iron Man

Celeste Biever and Rowan Hooper at New Scientist discuss the real world science featured in the new (Ma8, 2008) movie:

1. Superhero skin – An ‘Iron Man’ suit does not exist but portions of a wearable exoskeleton does.

2. Flying machines - SoloTrek was a flying exoskeleton that was apparently capable of travelling more than 200 kilometres. (The project shut down after a crash in 2002.) UK inventor and pilot Stuart Ross reckons his Rocketbelt packs enough power to lift him 2500 metres in the air and plans to test fly the latest model this year.

3. Friendly bots - In the movie, Stark has a friendly robot to help him build his armour. It looks too clever to be true, but in fact it is highly reminiscent of AUR. Built last year by MIT scientists, AUR is a robotic desk lamp that calculates where you are looking and moves its flexible neck to shine light on that spot.

4. Cunning computing – 'Pepper' Potts real-time translation program.

READ THE SECRET ORIGINS OF IRON MAN AT DIAL B FOR BLOG!:

Northern Lights Glimmer With Unexpected Trait

An international team of scientists has detected that some of the glow of Earth’s aurora is polarized, an unexpected state for such emissions. Measurements of this newfound polarization in the Northern Lights may provide scientists with fresh insights into the composition of Earth’s upper atmosphere, the configuration of its magnetic field, and the energies of particles from the Sun, the researchers say.

If observed on other planets, the phenomenon might also give clues to the shape of the Sun’s magnetic field as it curls around other bodies in the solar system.

At the north and south magnetic poles, many charged particles in the solar wind —a flow of electrically charged matter from the Sun—are captured by the planet’s field and forced to plunge into the atmosphere. The particles strike atmospheric gases, causing light emissions.

Lilensten and his colleagues observed weak polarization of a red glow that radiates at an altitude of 220 kilometers. The glow results from electrons hitting oxygen atoms. The scientists had suspected that such light might be polarized because Earth’s magnetic field at high latitudes funnels the electrons, aligning the angles at which they penetrate the atmosphere.

Fluctuations in the polarization measurements can reveal the energy of the particles coming from the Sun when they enter Earth’s atmosphere, Lilensten notes. The intensity of the polarization gives clues to the composition of the upper atmosphere, particularly with regard to atomic oxygen. link

Ref: Polarization in aurorae: A new dimension for space environments studies. 2008. Jean Lilensten et al. GEOPHYSICAL RESEARCH LETTERS, VOL. 35, L08804

Mysterious Striped Currents In Our Oceans

Between 1992 and 2003, scientists collected data from more than 10,000 drifting ocean buoys, which they tracked with satellites. The buoys’ movements were influenced mainly by known global currents, which are driven by wind and by differences in the temperature and salinity of seawater.

SubHuman © M. Ryan & M Schultz

But it emerged that something else had been subtly influencing the buoys’ paths. It turned out that there were alternating strips of water running eastward or westward, a bit like parallel moving sidewalks. Niiler recalls his reaction: “My God, we’ve never seen these before.”

Satellite measurements showed that the interfaces between adjacent currents were alternately associated with slight peaks and troughs in sea level. When the team looked at this variation globally, they found that the 150-kilometre-wide bands covered pretty much every ocean.

They recorded currents flowing in opposite directions at around 40 metres per hour. The flows extend right down to the ocean floor, and the boundaries between currents are alternately associated with peaks and troughs in temperature as well as sea level. This suggests that they influence processes such as nutrient and energy flow around the oceans, but this has yet to be proven, says Niiler.

What causes the striped flows remains a puzzle. “They are a fascinating new aspect to the ocean’s circulation, but the jury is still out on the mechanisms leading to their formation,” says Geoff Vallis of the Geophysical Fluid Dynamics Laboratory at Princeton University.

He points out that similar patterns exist in atmospheric flows on other planets, for example, Jupiter. Whether similar effects are at play here is unclear, he says. link

Ref: Maximenko, N. A., O. V. Melnichenko, P. P. Niiler, and H. Sasaki (2008), Stationary mesoscale jet-like features in the ocean. Geophys. Res. Lett., in press.

This Day In History: Nerve Gas Outbreak

In 1968, a sudden outbreak of startling sheep deaths in Skull Valley, Utah, was attributed to a nerve gas sprayed earlier by the Army on the nearby Dugway Proving Grounds. The investigation made by the National Communicable Disease Center was hampered by the Army's initial denial of responsibility and slowness to provide adequate gas samples for independent agencies to check. The debacle led to an overhaul of procedures concerning development of chemical weapons at Dugway. link.

“Contamination” trailer – music by Goblin:

Before The Big Bang

Until very recently, asking what happened at or before the Big Bang was considered by physicists to be a religious question. General relativity theory just doesn’t go there – at T=0, it spews out zeros, infinities, and errors – and so the question didn’t make sense from a scientific view.

But in the past few years, a new theory called Loop Quantum Gravity (LQG) has emerged. The theory suggests the possibility of a “quantum bounce,” where our universe stems from the collapse of a previous universe. Yet what that previous universe looked like was still beyond answering.

Physicists have now developed a simplified LQG model that gives an intriguing answer: a pre-Big Bang universe might have looked a lot like ours.

“The significance of this concept is that it answers what happened to the universe before the Big Bang,” Singh told PhysOrg.com. Our study shows that the universe on the other side is very classical as ours.”

“This means that the twin universe will have the same laws of physics and, in particular, the same notion of time as in ours,” Singh said. “The laws of physics will not change because the evolution is always unitary, which is the nicest way a quantum system can evolve. In our analogy, it will look identical to its twin when seen from afar; one could not distinguish them.”

That means that our universe today, roughly 13.7 billion years after the bounce, would share many of the same properties of the pre-bounce universe at 13.7 billion years before the bounce. In a sense, our universe has a mirror image of itself, with the Big Bang (or bounce) as the line of symmetry.

Ultimately, Corichi and Singh’s model might even tell us what a future universe would look like. Depending on how fast our present universe is accelerating – which will ultimately determine its fate – there’s a possibility that a generalization of the model would predict a re-collapse of our own universe.

Ref.: Quantum bounce and cosmic recall. 2008. Corichi, Alejandro, and Singh, Parampreet. In press, Physical Review Letters.