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When Will Virtual Surgery Make the Cut?

Within five years doctors will be able to simulate organs, soft tissue, and skeletal structure 

 
VIRTUALLY POSSIBLE: Within five years, the computing capability required to render virtually realistic organs and soft tissue will far surpass the technology available today to surgeons.  

 
MODEL PATIENT: Tissue, muscle and skin are elastic and behave like a spring, and their characteristics can be expressed using classical mathematical theory.

Video games that simulate the experiences of combat, space travel and car theft have achieved a startling level of fluidity and detail in recent years to create increasingly realistic virtual worlds. When it comes to medicine, however, the graphics that doctors and surgeons have to work with are closer to the grainy, cartoonish images of the Atari generation than they are to the video games Assassin's Creed or Grand Theft Auto.

The computing power required to render virtually realistic organs and soft tissue is still unavailable to most physicians (except for a handful with access to supercomputers), but it's coming, says Joseph Teran, an assistant mathematics professor at the University of California, Los Angeles.

Teran envisions a time within the next five years when medical professionals will be able to scan patients prior to procedures and create three-dimensional virtual images of their bodies, which they can store in computers and use for practice before performing the real surgeries.

Tissue, muscle and skin are elastic and behave like a spring, and their characteristics can be expressed using classical mathematical theory, Teran says.

To develop virtual models of patients, physicians must create geometric representations of their tissue and organs using either magnetic resonance imaging (MRI) or computed tomography (CT). The information that these scanners currently provide, however, is in the form of numbers representing shades of gray, which are insufficient for creating accurate, real-color, three-dimensional renderings. "It's a data processing problem, because this information is not in the correct format," Teran says. He also estimates that it would now take as many as 20 professionals up to nine months to produce even a roughly accurate model of the human body.

The answer? Faster computers with improved software algorithms that can solve mathematical problems that have unknown elements and multiple independent variables. Teran is confident that the technology will catch up with the demands placed on it, and that researchers must be ready for the day when this improved technology becomes available. "Even if you don't have eight-core processors now, you can use large computing clusters at universities to test your algorithms," he says. Some of his colleagues are even working with chipmaker Intel to make sure their software will work with future generations of Intel technology.

To date, virtual surgery models have been primarily used to create before and after images in reconstructive surgery procedures. Other uses have been limited to simulating specific body parts, such as an organ, a cluster of muscles or a craniofacial malformation. In reconstructive surgery, virtualization has been used to map movement disorders like those associated with cerebral palsy, allowing surgeons to, via a computer, rearrange a patient's muscular skeletal model to de-emphasize weaker muscles and emphasize stronger ones before setting foot in an actual operating room. Virtual surgery used in this manner has also been limited by technology, as most computers available to surgeons for this work can do little more than render relatively crude images of tissue, muscles and organs. "It's something that's there but more at a limited scale," Teran says.

As a graduate student, Teran worked with plastic surgeon Court Cutting at New York University Medical Center using computer graphic methods to develop statistical descriptions of three-dimensional images of craniofacial malformations and propose surgical methods for their correction. Cutting uses CT scans of each patient and employs a computer to map those images onto the image of a normal skull.

Once the hardware and software are available, it could take up to 20 years for this technology to become widely used by cost conscious hospitals and health care systems. But ultimately, Teran says, doctors will have access to the tools that will allow them to simulate abnormalities in any organ system based on computerized MRI and CT scans.

PR

Twisted Sister: Twin Planets Earth and Venus Were "Separated at Birth"

But they're definitely not identical; Venus today might portend an Earth ravaged by climate change 

south Venus  
SOUTH SIDE: Venus's southern hemisphere, shown here in ultraviolet.

Venus is similar in size and chemical makeup when compared with Earth—and the pair formed about the same time, more than four billion years ago. But that is apparently where the similarities end. According to a year's worth of data sent back from the European Space Agency's Venus Express orbiter launched in November 2005, the second planet from the sun is nothing like Earth—from its torrid surface to the upper reaches of its acid-laced atmosphere. The bottom line: just be glad you live here.

Here's some reasons why: Venus's surface temperature hovers around a sweltering 870 degrees Fahrenheit (465 degrees Celsius), its surface pressure is about 90 times that of Earth (which is akin to the pressure a kilometer, or 0.6 mile, below the ocean's surface), and there are no seasons there. The planet—Earth's closest neighbor—takes 243 days to turn on its own axis (and in the opposite direction) compared with Earth's swift 24-hour turnaround time. From the new data, scientists now know its atmosphere consists mostly of carbon dioxide, providing a glimpse of what global warming run amok may yield. Because of the extreme heat, water is only present in its atmosphere, so there are no oceans (and thus, no beaches). There are gale-force winds whipping about the planet, its smoglike clouds are composed of droplets of sulfuric acid (rather than water) and, contrary to previous belief, there is lightning on Venus. In other words, not only is it hot enough to evaporate an igloo on Venus in milliseconds, but you could also get struck by a bolt from the not-so-blue skies.

"Venus and Earth, they're really twins that were just separated at birth," Dimitry Titov, a researcher at the Max Planck Institute for Solar System Research in Katlenburg–Lindau, Germany, and co-author of several of nine papers in Nature on Venus Express's findings, said in a teleconference yesterday. "The key question is why those twins are so different."

An international team of scientists have been pouring over data streaming back from the Venus Express since April 2006 when it began surveying Venus, which at its minimum distance is around 25 million miles (40 million kilometers) from Earth.

At the planet's equator is a layer of turbulent air flow, which smoothes out at higher latitudes, notes Fred Taylor, a University of Oxford physicist and interdisciplinary scientist for the Venus Express mission. The wind speeds in the upper atmosphere are much faster than on Earth, partially due to the Venus's sluggish rotation. There is also evidence of vortexlike swirls of air that are thousands of miles wide at both of its poles, similar to those that appear over Earth's poles during their respective winter months.

Solar winds (gusts of ions from the sun's outer atmosphere capable of pulling apart molecules they encounter) suck up particles in Venus's atmosphere, untangle their atoms and spit them into space. Particulate matter in Earth's atmosphere is largely spared from the solar winds by our planet's strong magnetic field, something Venus lacks. As expected, scientists observed light, charged particles like hydrogen and helium ions leaving Venus's atmosphere. But they were surprised to discover that oxygen is also exiting. Researchers believe that water is being lost from the planet, because twice as many hydrogen as oxygen particles are leaving.

"Venus is very, very dry," says David Grinspoon, an astrobiologist at the Denver Museum of Nature & Science. All the water contained in its atmosphere, he adds, would be about slightly more than one inch (2.5 centimeters) deep if it were on the planet's surface. Analysis of the water leaving Venus's atmosphere, however, shows that many of the hydrogen ions are actually a stable isotope of the element called deuterium, which consists of a proton and a neutron (rather than just a proton) in its nucleus. "The amount of deuterium is an important clue to how much water has been lost over time," Grinspoon says. Researchers estimate that Venus has lost at least an ocean's worth of water since it formed, based on the deuterium particles being swept up by the solar wind.

"These differences are not just [due] to Venus being closer to the sun," Oxford's Taylor says. "We now know that the lack of a protective magnetic field and the differing planetary rotation rates also play a role in ensuring that many of the atmospheric processes we observe on Earth occur at a much faster rate on Venus. Our new data make it possible to construct a scenario in which Venus started out like the earth [did]—possibly including a habitable environment, billions of years ago—and then evolved to the state we see now."

venus south pole vortex 
VORTEX AHEAD: Venus Express captures a shot of the vortex at the planet's south pole.


venus south pole vortex 3d 
NOW IN 3D: The south polar vortex in 3-D as seen by the VIRTIS instrument on board ESA's Venus Express.





Venus has frequent bursts of lightning

Nearby Venus is looking a bit more Earth-like with frequent bursts of lightning confirmed by a new European space probe.

For nearly three decades, astronomers have said Venus probably had lightning — ever since a 1978 NASA probe showed signs of electrical activity in its atmosphere. But experts weren't sure because of signal interference.

Now a magnetic antenna on the European Space Agency's Venus Express probe proved that the lightning was real.

"We consider this to be the first definitive evidence of abundant lighting on Venus," David Grinspoon of the Denver Museum of Nature and Science told reporters Wednesday at a briefing in Paris.

The finding is significant because lightning affects atmospheric chemistry, so scientists will have to take it into account as they try to understand the atmosphere and climate of Venus, he said.

The lightning is cloud-to-cloud and about 35 miles above the surface, said University of California, Los Angeles geophysics professor C.T. Russell, lead author of a paper on the Venusian fireworks. It is being published in Thursday's issue of the journal Nature.

Bursts of electrical energy from lightning are something that scientists have long theorized could provide the spark of life in primordial ooze.

But not on Venus.

"If life was ever something serious to talk about on Venus, it would be early in its history, not in its current state," said Sean Solomon of the Carnegie Institution of Washington, who was not part of the research team. "It's a very unforgiving atmosphere."

The idea of Earth-like lightning is fascinating, Russell said. However, you couldn't see it from Venus' surface, nor would you want to look because the Venusian atmosphere is 100 times more dense than Earth's, is about 900 degrees hotter and has clouds of sulfuric acid, he said.

"It may be Earth's 'evil twin,' but it is in many respects Earth's twin," Russell said.

What excites astronomers most about the lightning discovery is simply the coolness factor.

Venus' weather forecasts have long thought to be "kind of boring ... steady winds for the next 400 years," said Allan Treiman, a senior scientist at the Lunar and Planetary Institute in Houston, who isn't affiliated with the research. The idea of lightning, he said, adds a spark to Venus' weather.

Photo
An artist's rendition released by the European Space Agency on Wednesday, Nov. 28, 2007 shows lightning striking the surface of planet Venus. Nearby planet Venus is looking a bit more Earth-like with frequent bursts of lightning



Success Depends on Others Failing

"In a sense it goes back to Aristotle," says the paper's senior author, Armin Falk, an economist. "The fact that we are social beings is a well-known fact." But the idea that rewards are context-dependent challenges a key assumption behind most traditional of economic theories: the premise that humans are essentially self-interested, that they care about their own work, income, achievements, and purchases, and that whatever other people do is, if not irrelevant, at least not going to have a consistent or predictable effect on decision-making.

Instead, the brain scans from this study support a mountain of survey data collected by modern economists and psychologists that suggests people care very much about keeping up with the Joneses. In the past, researchers have often struggled to work out how much they could trust that data, not sure whether survey-takers might be changing their response consciously or unconsciously based on what they thought was socially acceptable. The Science findings give further empirical evidence that people compare their gains to others'. "If you look at the brain reaction, it's a relatively immediate physiological reaction," says Falk. "It shows on a deeper level, in the brain, these things really matter."

The practical implications? Many scholars believe that social comparison helps to explain why, even as much of the world gets ever richer, people today don't report being happier than people did 50 years ago. We might not be happy now if we had to give up the amenities of the last half-century computers, air conditioners, a bedroom for every child, and more — but back when no one else had them either, life was okay.

There's also a lesson here for company managers, says Falk. A wage scale should reflect job and performance differences fairly, or else firms risk alienating their staff. "It's extremely important for companies to understand it's not just a matter of justice, but it's also a matter of efficiency," he says. It turns out the negative response to earning less is usually stronger than the positive response to earning more or as Falk says, "The pain of having less is much stronger than the joy of having more." Workers who discover they're earning more for the same work may be happy, but those who earn less can quickly feel slighted, killing motivation and often the quality of their output. It doesn't take a brain specialist to understand how that affects a business. 

Evolutionary 'Big Bang' Created Florist's Paradise

From the ubiquitous daisy to the fantastical orchid, flowering plant species are as diverse as they are numerous. Turns out, these bloomers went through an evolutionary "Big Bang" of sorts some 130 million years ago, a brief era of explosive floral diversification at a time when dinosaurs walked the Earth.

The origin of flowering plants called angiosperms has long baffled scientists, with Charles Darwin famously referring to the plant puzzler as an "abominable mystery."

"One of the reasons why it's been hard to understand evolutionary relationships among the major groups of flowering plants is because they diversified over such a short time frame," said researcher Robert Jansen, professor of integrative biology at the University of Texas at Austin.

Two papers published online this week in the Proceedings of the National Academy of Sciences, reveal the evolutionary relationships between major groups of plant species. The results show a stunning diversification occurred within a period of 5 million years just after the plants first appeared on the scene and gave rise to today's five major lineages of flowering plants

"Flowering plants today comprise around 400,000 species," said Pam Soltis, curator at the University of Florida's Florida Museum of Natural History. "To think that the burst that gave rise to almost all of these plants occurred in less than 5 million years is pretty amazing—especially when you consider that flowering plants as a group have been around for at least 130 million years."

Pam and UF colleague Doug Soltis analyzed 61 genes from 45 plant species, while another team led by Jansen analyzed 81 genes from 64 plant species. Both groups focused on the genomes of the chloroplast, an organelle shared by all green plants that is responsible for their ability to photosynthesize.

Then, they arranged the gene sequences into diagrams to reflect the relationships among plant lineages throughout evolutionary history. From the length of the diagrams' branches along with known rates of genetic change, the teams estimated that three lineages went through a major diversification in an evolutionary "blink of an eye."

As for the cause of the explosion of plant diversity, that's still a floral mystery. Perhaps a major climatic event was the trigger, the researchers suggest. Another idea is that a new evolutionary trait, such as the development of a plant's water-conducting tube, jumpstarted the diversification. 

 
Phylogenetic relationships among the major lineages of flowering plants. Pictured counter-clockwise from the root at the base of the circle tree are: Amborella trichopoda, Nymphaea odorata, Illicium floridanum, Chloranthus angustifolius, Piper longum, Liriodendron tulipifera, Ceratophyllum demersum, Ranunculus ficaria, Pelargonium exstipulatum, Helianthus annuus, Yucca filamentosa, Triticum aestivum, and Acorus americanus. New Caledonia, home to Amborella trichopoda, is shown in the background. 

 
Two new studies reveal an explosion of plant diversity occurred in a stint of 5 million years just after flowering plants first appeared on Earth, giving rise to today's five major lineages, including plants such as orchids. 

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