Oldest Known Jellyfish Fossils Found

Oldest Known Jellyfish Fossils Found

The oldest known fossils of jellyfish have been found in rocks in Utah that are more than 500 million years old, a new study reports.

The fossils are an unusual discovery because soft-bodied creatures, such as jellyfish, rarely survive in the fossil record, unlike animals with hard shells or bones.

"The fossil record is biased against soft-bodied life forms such as jellyfish, because they leave little behind when they die," said study member Bruce Lieberman of the University of Kansas.

These jellyfish left their lasting imprint because they were deposited in fine sediment, rather than coarse sand. The film that the jellyfish left behind shows a clear picture, or "fossil snapshot," of the animals.

"You can see a distinct bell-shape, tentacles, muscle scars and possibly even the gonads," said study team member Paulyn Cartwright, also of KU.

The rich detail of the fossils allowed the team to compare the cnidarian (the phylum to which jellyfish, coral and sea anemones belong) fossils to modern jellyfish. The comparison confirmed that the fossils were, in fact, jellyfish and pushed the earliest known occurrence of definitive jellyfish back from 300 million to 505 million years ago.

The fossils also offer insights into the rapid species diversification that occurred during the Cambrian radiation, which began around 540 million years ago and when most animal groups start to show up in the fossil record, Lieberman said.

The complexity of these early jellyfish seems to suggest that either the complexity of modern jellyfish developed rapidly about 500 million years ago, or that jellyfish are even older and developed long before that time.

Cambrian fossil jellyfish shows similarity to the modern jellyfish, Periphylla. 

Using Satellites to Pinpoint and Predict Pollution

Using Satellites to Pinpoint and Predict Pollution

The European Space Agency is expanding its satellite data network to better track air pollution on a global scale

	BREATH OF FRESH AIR:  ESA's Tropospheric Emission Monitoring Internet Service (TEMIS) provides data on levels of nitrogen dioxide (NO2) in the atmosphere. NO2 is a known pollutant that has been linked to respiratory illness, climate change and acid rain.

As NASA gets to work on the Constellation Program—the space agency's next not-so-small-step for mankind that hopes to put U.S. astronauts back on the moon by 2020—the European Space Agency (ESA) has set its sights on learning more about our own planet. Toward that end the agency this month, at its Tropospheric Emission Monitoring Internet Service (TEMIS) conference in Italy, touted its ability to provide free atmospheric and environmental data to help nations assess air pollution problems.

ESA's TEMIS delivers data in what the agency calls "near-real time" and also provides long-term forecasts based on tropospheric trace gas concentrations, aerosols and ultraviolet (UV) radiation. TEMIS gathers information from its own satellites and also has agreements with NASA and the Darmstadt, Germany–based European Organization for the Exploitation of Meteorological Satellites (EUMETSAT) to make their data available on its Web site. This data includes info from the Ozone Monitoring Instrument (OMI) on NASA's Aura satellite and the Global Ozone Monitoring Experiment (GOME-2) instrument on the MetOp satellite, which was developed by EUMETSAT and ESA to provide a closer view of the atmosphere from low Earth orbit.

ESA plans to expand TEMIS to monitor the transboundary and hemispheric movement of air pollution. The OMI and GOME-2 instruments are spectrometers, which can pinpoint different trace gases in wavelength ranges, providing a measure of Earth's entire atmosphere in a single day.

"Key users of this data are environmental agencies [that] have to report on things like greenhouse gases," says Claus Zehner, an ESA Earth observation application engineer, noting that the European Union (E.U.) continues to keep tabs on air quality over its member nations. By law, they have to report each year on the status of the air quality in their countries, he adds. The E.U. is now considering changing its European Air Quality monitoring laws to mandate the use of satellite data.

SURF'S UP:  ESA Envisat, an advanced polar-orbiting Earth observation satellite that provides measurements of the atmosphere, ocean, land and ice, here illustrates the complexity of the thermal currents at play in the Southern Mediterranean off the coast of Northern Libya.

Among the most important info ESA has provided is data on levels of nitrogen dioxide (NO₂) in the atmosphere. NO₂, a known pollutant, has been linked to respiratory ills and environmental destroyers such climate change and acid rain. Researchers have identified major NO₂ hot spots and industrial culprits, thanks to ESA data gathered between 1996 and 2006.

ESA data has traditionally been used by environmental protection agencies in European Community countries, but its use is spreading. Researchers at Harvard University, for example, used Aura's OMI data to analyze changes in air quality achieved by limiting traffic in Beijing during a China–Africa summit held there last year. In an attempt to ease travel congestion, Beijing officials reduced traffic flow by 30 percent during the conference, barring some 800,000 of its 2.82-million strong fleet of private vehicles from traveling within city limits.

TEMIS enabled Harvard researchers to obtain accurate, independent measurements of NO₂ in the city air at that time. By comparing the satellite observations with measurements from the ground, along with a global chemical transport model, they learned that the atmospheric models failed to accurately reflect a dramatic 40 percent drop in nitrogen dioxide levels in Beijing's air during the traffic restriction, says Yuxuan Wang, a Harvard lecturer and research assistant specializing in atmospheric chemistry.

"Without the TEMIS data, I would say that it would be impossible to do" the Beijing emissions study, Wang says. Chinese scientists were able to provide some data, she says, but it didn't come close to the details captured by the satellites. Wang and her colleagues continue to use ESA data to study regional NO₂ emission distribution as well as gauge the amount of nitric oxide (NO) plus nitrogen dioxide (collectively known as NO_X) present in the air.

ESA data has also been used to study patterns of gaseous pollutant emissions throughout India and to assess the prevalence of disease related to air pollution in New Zealand.

Zehner says that the agency plans to build and launch at least five "sentinel" satellites to monitor not only trace gases that indicate pollution in the atmosphere, but also the surface temperature of the oceans, the movement of ice and the shifting of land masses. The first three are expected to launch by 2012; the remaining two are tentatively scheduled to be sent into orbit by 2015, he says.

ESA's goal is to provide reliable information that can be used to advocate and establish policies designed to improve the environment, Zehner says, adding, "We are offering the first steps needed for monitoring greenhouse gases and other environmental areas."

When the Eyes Play Tricks on the Ears

When the Eyes Play Tricks on the Ears

The way a primitive auditory structure in the brain processes visual information may explain how we are fooled by thrown voices

	AN AUDIO-VISUAL ILLUSIONIST:  Ventriloquists may take advantage of the simultaneous processing of both auditory and visual cues by a brain structure, called the inferior colliculus, to throw their voice to their dummy.

If you watched football or the final game of the World Series yesterday, you may have noticed the following: When the announcers were speaking on camera, it seemed as though the sound of their voices were coming from their mouths. But when the commentary occurred off-screen as the game action was shown, it was quite apparent the TV speakers were the actual sound source of the endless color-commentary babble.

This processing phenomenon in which a visual cue affects how one perceives an auditory stimulus—ventriloquism is another example—may be explained by new research that pinpointed neurons in a primitive brain area that responds to both visual and auditory information. This area, the inferior colliculus region in the midbrain, less than half an inch in diameter, is a way station for nearly all auditory signals as they travel from the ear to the cortex (the brain's central processing area). 

"It's important if you're going to be integrating visual and auditory information that they be on a level playing field, so both are encoded the same way," says Jennifer Groh, an associate professor at Duke University's Center for Cognitive Neuroscience and a co-author of the new work published in Proceedings of the National Academy of Sciences USA. "It's important for the auditory pathway to know where the eye is pointed."

Groh and her colleagues planted electrodes in the brains of three monkeys, targeting 180 individual neurons (or nerve cells) in the inferior colliculus. The animals were placed in a dark chamber where a light-emitting diode (LED) would switch on in one of several predetermined locations. After the monkeys attended to and fixated on the light for a few fractions of a second, a short clip of white noise would play from speakers in the chamber.

When the researchers examined the time-stamped activity of the individual neurons, they observed that each monkey had a neural response in its inferior colliculus when the LED turned on. In addition, two of the three animals showed activity in the auditory structure as they moved their eyes toward the light. In all, the scientists report that more than 67 percent of the neurons monitored (121 of the 180) showed statistically significant responses to the visual stimulus.

"The implication is that it's possible that perception involves more interaction between the sensory pathways than we expected and, because they are happening in low-level areas, they may be more automatic," Groh says. She adds that some cells responded more quickly to the light, although others had a buildup of activity. She speculates that the quicker acting cells process the information whereas the slower ones may encode a reward response (a secondary function of the inferior colliculus).

Christoph Kayser, a research scientist at the Max Planck Institute for Biological Cybernetics in T¨bingen, Germany, calls the new work "stunning." "Results like these suggest that the brain does not try to keep the information provided by the different sensory organs as isolated as possible, but rather that an early mixing of sensory information seems to be the rule," he says. "All this can best be interpreted when seeing the brain as being faced with a flood of sensory information that must be co-registered and merged into a coherent percept." 

Cold spot could be relic of Big Bang

Cold spot could be relic of Big Bang

A cold spot in the oldest radiation in the universe could be the first sign of a cosmic glitch that might have originated shortly after the Big Bang, British and Spanish scientists said on Thursday.

They think this spot -- detected on satellite maps of microwave radiation -- might be a cosmic defect or texture, a holdover from the universe's infancy. But they said their theory would need confirmation.

Such defects or textures, they theorize, reflect a flaw in the pattern of the universe as it formed -- think of a snag in pantyhose or a flaw in a diamond.

"If the cold spot is indeed proven to be a texture, it will completely change our view of how the universe evolved following the Big Bang," said Mike Hobson, of the Astrophysics Group at the University of Cambridge's Cavendish Laboratory, whose study appears in the journal Science.

Hobson, Neil Turok and colleagues at the Institute of Physics at Cantabria based this theory on an analysis of a large cold spot in the cosmic microwave background radiation, which is basically the heat glow left over from the formation of the universe.

The cold spot was discovered in 2003 by NASA's Wilkinson Microwave Anisotropy Probe satellite, and its presence has been the subject of many theories, said Al Kogut of the NASA Goddard Space Flight Center.

Kogut, who did not work on the paper, said if this texture theory is proven, it would offer a window into the universe shortly after the Big Bang some 14 billion years ago, showing places where the universe was expanding and cooling.

"If you imagine water cooling down in an ice cube tray, it will make a transition from a liquid state to solid crystal," Kogut said in a telephone interview.

If that occurs very slowly, he said, that transition goes very smoothly, producing crystal clear ice. But if it goes very fast, the crystal aligns in different directions. Where they don't agree, a crack appears, he said.

This paper "is basically saying this cold spot is a relic of igh-energy physics that occurred immediately after the Big Bang," Kogut said.

"They're claiming they've found one of these things and it could be the tip of the iceberg," he said.

But Kogut, like the study's authors, said he would like more proof. "The evidence is encouraging, but far from compelling," he said.

An undated image of the infant universe with 'warmer' spots represented by red and 'cooler'...

All systems go

All systems go

A powerful way of studying biology looks set for take-off

SEVEN years ago, one of the attractions at the now-defunct Millennium Dome in London was what looked like a remarkably detailed video of a beating human heart. People could admire the heart's delicate tracery of blood vessels with the muscle stripped away and hear a display of its electrical activity that would not have disgraced a disco. The voiceover described it as “one of the most powerful tools we have in the fight against disease”, but few of the visitors understood why.

Actually, the beating heart was no simple video. It was, instead, the output of a stupendously complex computer model of a heart, developed over more than 40 years. This model is an example of “systems biology”, an approach that represents a significant shift both in the way biologists think about their field and in how they go about investigating it.

A central tenet of most scientific endeavour is the notion of reductionism—the idea that things can best be understood by reducing them to their smallest components. This turns out to be immensely useful in physics and chemistry, because the smallest components coming from a particle accelerator or a test tube behave individually in predictable ways.

In biology, though, the idea has its limits. The Human Genome Project, for example, was a triumph of reductionism. But merely listing genes does not explain how they collaborate to build and run an organism. Nor do isolated cells or biological molecules give full insight into the causes and development of diseases that ravage whole organs or organisms. A complete understanding of biological processes means putting the bits back together again—and that is what systems biologists are trying to do, by using the results of a zillion analytical experiments to build software models that behave like parts of living organisms.

You can't beat the system

The pharmaceutical industry stands to gain much from this approach. Around 40% of the compounds that drug companies test cause arrhythmia, a disturbance to the normal heart rate. Drugs such as the anti-inflammatory medicine Vioxx and the diabetes treatment Avandia have been linked with an increased risk of heart disease. The result is that billions have been wiped off their makers' share prices.

Not surprisingly, the pharmaceutical industry has sought out Denis Noble of Oxford University, the creator of the beating-heart model, to help. Dr Noble is now part of a consortium involving four drug firms—Roche, Novartis, GlaxoSmithKline and AstraZeneca—that is trying to unravel how new drugs may affect the heart. Virtual drugs are introduced into the model and researchers monitor the changes they cause just as if the medicines were being applied to a real heart. The production of some proteins increases while others are throttled back; these changes affect the flow of blood and electrical activity. The drugs can then be tweaked in order to boost the beneficial effects and reduce the harmful ones.

Systems biology thus speeds up the drug-testing process. Malcolm Young is the head of a firm called e-Therapeutics, which is based in Newcastle upon Tyne. Using databases of tens of thousands of interactions between the components of a cell, his company claims to have developed the world's fastest drug-profiling system. In contrast to the two years it takes to assess the effects of a new compound using conventional research methods, Dr Young's approach takes an average of just two weeks. Moreover, the company has been looking at drugs known to have damaging side effects and has found that its method would have predicted them.

Testing for reactions in this way could also offer a more rigorous route to assessing alternative therapies, such as herbs and clinical nutrition (which seeks to control disease through the use of particular foodstuffs). These remedies are often dismissed as unscientific because they have a multitude of effects on the body that are hard to quantify. Studying multiple effects, however, is precisely what models like the virtual heart are able to do.

Nor need such models be confined to people. In biological terms, mice are better understood than men, and a team in the Netherlands is using a computer model of mouse physiology to investigate the effects of a high-fat diet, by monitoring the concentration of various components of the blood. The team, from a firm called SU BioMedicine, which is based in Zeist, found that the active ingredients of a particular concoction of Chinese herbal medicines have the same effect on blood composition as the anti-obesity drug Rimonabant. The hope is that systems-biology studies like these will eventually trace out the pathways the herbs are affecting.

Such models may also help to pin down the causes of diseases that arise from the interplay of genetic and environmental factors. Andrew Ahn of Harvard Medical School cites the example of diabetes, for which the standard clinical test is a measure of the level of glucose in the blood. But that is a single snapshot in time. Dr Ahn suggests that the way toward a fuller understanding of diabetes is to track glucose levels against other factors such as diet, sleeping habits and psychological health. He proposes to employ a systems-biology model to do so.

Ultimately, the aim is to build an entire virtual human for researchers to play with. But reductionism is still needed to get there. Human bodies are made of cells, and the best way to build a model body might be to construct a general-purpose virtual cell that can be reprogrammed into being any one of the 220 or so specialised sorts of cell of which the human body is composed. That, after all, is how real bodies develop. And a collaboration organised by the European Science Foundation is hoping to do just this, through what it calls the Blue Cell project.

Keeping track of the data needed to carry out systems biology on this scale will be a Herculean task, and may turn out to be the driver of future developments at the heavy-number-crunching end of the computer industry. Dr Noble is in negotiations with Fujitsu, a Japanese computer firm that is developing a machine capable of performing some ten thousand trillion calculations a second. That would make it the world's fastest computer, but it comes with a price tag to match—about a billion dollars. This is a little more than the $6m paid for that fictional bionic man, Steve Austin, even allowing for inflation. But it is only about a quarter of what the Human Genome Project cost. And this time, it might produce some answers that prove immediately useful.