Sunday, May 4, 2008

The reason fat people find it hard to lose weight is found

Scientists have discovered why fat people find it so hard to lose weight, which will lead to many new approaches to weight loss.
The difference in the number of fat cells between lean and obese people is established in childhood and, although fat people replenish fat cells at the same rate as thin ones, they have around twice as many.

This remarkable glimpse of what gives us beer guts, love handle and muffin tops could also lead to new approaches to fight the flab, by cutting the overall number of fat cells in the body, as well as providing an insight into why fat people find it so hard to lose weight, because the number of fat cells in a person remains the same, even after a successful diet.

The details of how humans regulate their fat mass is reported today in the journal Nature by a team led by scientists at the Karlolinksa Institute, Stockholm, Sweden, as a second team, led by Imperial College London, reports in the journal Nature Genetics the discovery of a gene sequence present in half the population linked to three quarters of an inch bigger waistline, four lb gain in weight, and a tendency to become resistant to insulin, which can lead to type 2 diabetes.

The fundamental new insight into the cause of obesity comes from an international team lead by Dr Kirsty Spalding, Prof Jonas Frisén and Prof Peter Arner who found the body constantly produces new fat cells to replace equally rapid break down of the already existing fat cells due to cell death.

They also show, that overweight people generate and replace more fat cells than do lean - and that the total number of fat cells stays equal after a diet program.

Until now, it was not clear that adults could make new fat cells. Some had assumed that they increase their fat mass by incorporating more fats into already existing fat cells in order to maintain their body weight (lean, overweight, obese). However now it seems we constantly produce new fat cells irrespective of our body weight status, sex or age.

"The total number of fat cells in the body is stable over time, because the making of new fat cells is counterbalanced by an equally rapid break down of the already existing fat cells due to cell death", says Prof Arner.

The study was made possible by a method to use radioactive isotopes in fat cells from people who had lived through the brief period of Cold War nuclear bomb testing from 1955 to 1963 to determine the age of the fat cells in the body.

This was combined with methods to carefully measure the size of the fat cells in relation to the total amount of adipose tissue in 687 people with a large individual variation in body weight who had undergone liposuction and abdominal reconstruction surgery.

Fat cells are replaced at the same rate that they die - roughly 10 per cent every year. The level of obesity is determined by a combination of the number and size of fat cells, which can grow or shrink as fat from food is deposited in them.

Even if obese subjects go on a diet they keep the total number of fat cells in the body constant, but the size of individual fat cells is decreased markedly.

The findings therefore provide a new target for treatment of obesity, namely by attacking the signals and genes in fat cells that control the formation of new such cells.

"The results may, at least in part, explain why it is so difficult to maintain the weight after slimming", adds Prof Arner.

"Until now it was not clear whether there was fat cell turnover in adults," adds Dr Spalding. "Now we have established this does occur, we can target the process.

"Various groups are looking at compounds that might regulate the formation of fat cells but this work is at too early a stage to say when anti obesitiy drugs based on this understanding will be tested on patients, if at all."

Other new insights into how to treat obesity could come from the gene sequence linked to an expanding waist line, weight gain and a tendency to develop type 2 diabetes in the Imperial led study.

Professor Jaspal Kooner, the paper's senior author from the National Heart and Lung Institute at Imperial College London, says: "Finding such a close association between a genetic sequence and significant physical effects is very important, especially when the sequence is found in half the population."

The study shows that the sequence is a third more common in those with Indian Asian than in those with European ancestry. This could provide a possible genetic explanation for the particularly high levels of obesity and insulin resistance in Indian Asians, who make up 25 per cent of the world's population, but who are expected to account for 40 per cent of global heart disease by 2020.

The new gene sequence sits close to a gene called MC4R, which regulates energy levels in the body by influencing how much we eat and how much energy we expend or conserve. The researchers believe the sequence is involved in controlling the MC4R gene, which has also been implicated in rare forms of extreme childhood obesity.

Previous research on finding the genetic causes of obesity has identified other energy-conserving genes. Combining knowledge about the effects of all these genes could pave the way for transforming how obesity is managed.

This research, backed by the British Heart Foundation, was carried out with scientists from the University of Michigan and the Pasteur Institute, France.

Last year a British led team found that if people carry one copy of a variant in a gene called FTO, as does half of the general population, it will lead to a gain in weight of 2.6lb or put just over half an inch on their waists and raise their risk of being obese by one third.

If people have two copies of this variant in the FTO gene, which is the case in one in six of the population, then they will gain almost 7lb more than those who lack the variation and are at a 70 per cent higher risk of obesity.

According to the 2001 Health Survey for England, more than a fifth of males and a similar proportion of females aged 16 and over were classified as obese.

Half of men and a third of women were classified as overweight.

Original here

Do different cells in our nose respond to different smells?

smelling flower


People can smell thousands—perhaps even millions—of different scents. Yet scientists know that in the nose, there are only about 400 different types of odor receptors—proteins that capture scented molecules so that smells can be identified. Thus, there isn’t, obviously, one type of receptor that responds to a rose, while another jumps for jasmine.

So how can we smell so much, with so few types of receptors?

The answer is that cells mix and match. Each nerve cell in the nose can sense more than one odor, but picks up the smell to a different degree. An odor's unique signature depends on which cells respond to it, and how intensely.

What happens when you inhale a rose is that a group of cells is stimulated, and that group sends a combination of signals to the olfactory bulb—the site at the very front of the brain where smell perception takes place. This unique combination of signals tells the brain the odor is the smell of a rose.

How the olfactory bulb interprets this signal as the smell of a rose is not well understood, but scientists do have some insights into the process. For example, many researchers have used brain scans to see what areas of the brain become active after people are exposed to different smells. It is unclear, however, whether that activation corresponds to recognizing a given smell. And other factors—for example our past experiences with certain smells, and whether we liked them or were turned off—also play a role in how we perceive them.

In other words, a rose is a rose is a rose, as Gertrude Stein wrote, but not always to our nose.

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Rare but Real: People Who Feel, Taste and Hear Color

The colors of letters and numbers in this photo illustration of Ingrid Carey, by Ingrid Carey, match up with what she sees.

When Ingrid Carey says she feels colors, she does not mean she sees red, or feels blue, or is green with envy. She really does feel them.

She can also taste them, and hear them, and smell them.

The 20-year-old junior at the University of Maine has synesthesia, a rare neurological condition in which two or more of the senses entwine. Numbers and letters, sensations and emotions, days and months are all associated with colors for Carey.

The letter "N" is sienna brown; "J" is light green; the number "8" is orange; and July is bluish-green.

The pain from a shin split throbs in hues of orange and yellow, purple and red, Carey told LiveScience.

Colors in Carey's world have properties that most of us would never dream of: red is solid, powerful and consistent, while yellow is pliable, brilliant and intense. Chocolate is rich purple and makes Carey's breath smell dark blue. Confusion is orange.

Scientific acceptance

Long dismissed as a product of overactive imaginations or a sign of mental illness, synesthesia has grudgingly come to be accepted by scientists in recent years as an actual phenomenon with a real neurological basis. Some researchers now believe it may yield valuable clues to how the brain is organized and how perception works.

"The study of synesthesia [has] encouraged people to rethink historical ideas that synesthesia was abnormal and an aberration," says Amy Ione, director of the Diatrope Institute, a California-based group interested in the arts and sciences.

The cause remains a mystery, however.

According to one idea, irregular sprouting of new neural connections within the brain leads to a breakdown of the boundaries that normally exist between the senses. In this view, synesthesia is the collective chatter of sensory neighbors once confined to isolation.

Another theory, based on research conducted by Daphne Maurer and Catherine Mondloch at McMaster University in Ontario, Canada, suggests all infants may begin life as synesthetes. In this way of thinking, animals and humans are born with immature brains that are highly malleable. Connections between different sensory parts of the brain exists that later become pruned or blocked as an organism matures, Mondloch explained.

Maurer and Mondloch hypothesize that if these connections between the senses are functional, as some experiments suggest, then infants should experience the world in a way that is similar to synesthetic adults.

In a variation of this theory, babies don't have five distinct senses but rather one all-encompassing sense that responds to the total amount of incoming stimulation. So when a baby hears her mother's voice, she is also seeing it and smelling it.

Technology lags

Maurer and Mondloch's pruning hypothesis is intriguing, says Bruno Laeng, a psychology professor at the University of Tromso, Norway. But he adds a caution.

"At present, we do not have the technology to observe brain-connection changes in the living human brain and how these relate to mental changes," Laeng said in an email interview.

Like other scientists, Laeng also questions whether synesthesia needs such extra neural connections in order to occur. Advancements in current brain imaging techniques may one day allow the pruning hypothesis to be tested directly, he said.

According to another theory that does not rely on extra connections, synesthesia arises when normally covert channels of communications between the senses are exposed to the light of consciousness.

All of us are able to perceive the world as a unified whole because there is a complex interaction between the senses in the brain, the thinking goes. Ordinarily, these interconnections are not explicitly experienced, but in the brains of synesthetes, "those connections are 'unmasked' and can enter conscious awareness," said Megan Steven, a neuroscientist at Beth Israel Deaconess Medical Center.

Because this unmasking theory relies on neural connections everyone has, it may explain why certain drugs, like LSD or mescaline, can induce synesthesia in some individuals.

'Like I'm crazy'

Many synesthetes fear ridicule for their unusual abilities. They can feel isolated and alone in their experiences.

"Most people that I'd explain it to would either be fascinated or look at me like I'm crazy," Carey said. "Especially friends who were of a very logical mindset. They would be very perplexed."

The study of synesthesia is therefore important for synesthetes, says Daniel Smilek, an assistant psychology professor at the University of Waterloo in Ontario, Canada.

Research is revealing synesthetes to be a varied bunch.

More on Synesthesia

Synesthesia is from the Greek syn (union) and the aisthesis (sensation).

"If you ask synesthetes if they'd wish to be rid of it, they almost always say no. For them, it feels like that's what normal experience is like. To have that taken away would make them feel like they were being deprived of one sense."
-- Simon Baron-Cohen, synesthesia researcher at the University of Cambridge

A group at MIT has a web page that shows how synesthetes might perceive letters as having colors.

Smilek and colleagues have identified two groups of synesthetes among those who associate letters and numbers with colors, he explained in a telephone interview. For individuals in one group, which Smilek calls "projector" synesthetes, the synesthetic color can fill the printed letter or it can appear directly in front of their eyes, as if projected onto an invisible screen. In contrast, "associate" synesthetes see the colors in their "mind's eye" rather than outside their bodies.

In Carey's case, the colors appear in quick flashes right behind her eyes, blinking in and out of existence as quickly as ocean foam. Other times they linger, coalescing and dividing like sunlight on the surface of a soap bubble.

'No mere curiosity'

Other subgroups have also been identified.

The synesthesia of those in the "perceptual" category is triggered by sensory stimuli like sights and sounds, whereas "conceptual" synesthetes respond to abstract concepts like time. One conceptual synesthete described the months of the year as a flat ribbon surrounding her body, each month a distinct color. February was pale green and oriented directly in front of her.

Richard Cytowic, a neuroscientist and author of "The Man Who Tasted Shapes" (Bradford Books, 1998), has watched the scientific shift in attitudes toward the condition in recent years.

"Many of my colleagues claimed that synesthesia was 'made up' because it went against prevailing theory," Cytowic told LiveScience. "Today, everyone recognizes synesthesia as no mere curiosity but important to fundamental principles of how the brain is organized."

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Of myths and men

Worries about an apocalypse unleashed by particle accelerators are not new, says Philip Ball. They have their source in old myths, which are hard to dispel.

When physicists dismiss as a myth the charge that the Large Hadron Collider (LHC) will trigger a process that might destroy the world, they are closer to the truth than they realize.

In common parlance, a myth has come to denote a story that isn’t true, but in fact it is a story that is 'psychologically true'. A myth is not a false story but an archetypal one. And the archetype for this current bout of scare stories is obvious: the Faust myth, in which an hubristic individual unleashes forces he or she cannot control.

The LHC is due to be switched on this summer at CERN, the European centre for particle physics near Geneva. But some fear that the energies released by colliding subatomic particles will produce miniature black holes that will engulf the world. Walter Wagner, a resident of Hawaii, has even filed a lawsuit to prevent the experiments.

As high-energy physicist Joseph Kapusta from the University of Minnesota in Minneapolis points out1, such dire forebodings have accompanied the advent of other particle accelerators, including the Bevalac in California and the Relativistic Heavy Ion Collider (RHIC) in New York. In the latter case, newspapers seized on the notion of an apocalyptic event — just as the facility went into operation, Britain's Sunday Times ran a story under the headline The Final Experiment?

Swallowing Earth

The Bevalac, an amalgamation of two existing accelerators at the Lawrence Berkeley National Laboratory, was created in the 1970s to investigate extremely dense states of nuclear matter — stuff made from the compact nuclei of atoms. In 1974, two physicists proposed that there might be a hitherto unseen and ultra-dense form of nuclear matter more stable than ordinary nuclei, which they rather alarmingly dubbed ‘abnormal’. If so, there was a small chance that even the tiniest lump of it could keep growing indefinitely by engulfing ordinary matter. Calculations implied that a speck of this pathological form of abnormal nuclear matter made in the Bevalac would sink to the centre of Earth and then expand to swallow the planet, all in a matter of seconds.

No one, Kapusta says, expected that abnormal nuclear matter, if it existed, would really have this voracious character — but neither did anyone know enough about the properties of nuclear matter to rule it out. According to physicists Subal Das Gupta from McGill University in Montreal, Canada, and Gary Westfall at Michigan State University in East Lansing, who wrote about the motivations behind the Bevalac to mark its termination in 19932, “Meetings were held behind closed doors to decide whether or not the proposed experiments should be aborted.”

The RHIC, at the Brookhaven National Laboratory, began operating in 1999 mainly to create another predicted super-dense form of matter called a quark–gluon plasma. This is thought to have been what the Universe consisted of less than a millisecond after the Big Bang. After an article about it was published in Scientific American 3, worries were raised about whether matter this dense might collapse into a mini black hole that would again then grow to engulf the planet.

Strange, but true?

“And yet, might there really be some substance to these fears?”

Physicist Frank Wilczek at the Massachusetts Institute of Technology in Cambridge dismissed this idea as “incredible”, but at the same time he raised a new possibility: the creation of another super-dense, stable form of matter called a strangelet that could also be regarded as a potential Earth-eater. In a scholarly article published in 2000, Wilczek and several colleagues analysed all the putative risks posed by the RHIC, and concluded that none posed the slightest real danger4.

But isn’t this just what we would expect high-energy physicists to say? That objection was raised by Richard Posner, a distinguished professor of law at the University of Chicago in Illinois5. He argued that scientific experiments that pose potentially catastrophic risks, however small, should be reviewed in advance by an independent board. He recognized that current legal training provides lawyers and judges with no expertise for making assessments about scientific phenomena “of which ordinary people have no intuitive sense whatsoever”, and asserted that such preparation is therefore urgently needed.

It seems reasonable to insist that, at the very least, such research projects commission their own expert assessment of risks, as is routinely done in some areas of bioscience. The LHC has followed the example of the RHIC in doing just that. A committee has examined the dangers posed by strangelets, black holes and the effects of possible ‘hidden’ extra dimensions of space. In 2003, it concluded that there is “no basis for any conceivable threat” from the accelerator’s high-energy collisions6.

Runaway gloop

These scare stories are not unique to particle physics. When in the late 1960s Soviet scientists mistakenly thought they had found a new, waxy form of pure water called polywater, one scientist suggested that it could ‘seed’ the conversion of all the world’s oceans to gloop — a scenario memorably anticipated in Kurt Vonnegut’s 1963 novel Cat’s Cradle, in which the culprit was instead a new form of ice. Super-viruses leaked from research laboratories are a favourite source of rumour and fear — this was one suggestion for the origin of AIDS. And nanotechnology was accused of hastening doomsday thanks to one commentator’s fanciful vision of grey goo: replicating nanoscale robots that disassemble the world for raw materials from which to make copies of themselves.

In part, the appeal of these stories is simply the frisson of an eschatological tale, the currency of endless disaster movies. But it is also noteworthy that these are human-made apocalypses, triggered by the heedless quest for knowledge about the Universe.

Myths like that of Faust (here the 1865 Johann Wolfgang Goethe edition) are long-lived.Myths like that of Faust (here the 1865 Johann Wolfgang Goethe edition) are long-lived.

This is the template that became attached to the Faust legend. Initially a folk tale about an itinerant charlatan with roots that stretch back to the Bible, the Faust story was later blended with the myth of Prometheus, who paid a harsh price for daring to challenge the gods because of his thirst for knowledge. Goethe’s Faust embodied this fusion, and Mary Shelley popularized it in Frankenstein, which she explicitly subtitled ‘Or The Modern Prometheus’. Roslynn Haynes, a professor of English literature, has explored how the Faust myth shaped a common view of the scientist as an arrogant seeker of dangerous and powerful knowledge7.

All this sometimes leaves scientists weary of the distrust they engender, but Kapusta points out that it is occasionally even worse than that. When Das Gupta and Westfall wrote about the concerns of abnormal nuclear matter raised with the Bevalac, they were placed on the US Federal Bureau of Investigation’s ‘at risk’ list of individuals thought to be potential targets of the Unabomber. Between 1978 and 1995, the bomber — a mathematician living in a forest shack in Montana — sent bombs through the US mail to scientists and engineers he considered to be working on harmful technologies. A lawsuit by a disgruntled Hawaiian seems mild by comparison.

Risky business

And yet, might there really be some substance to these fears? During the Manhattan Project that developed the atomic bomb, several of the scientists involved were a little unsure — until they saw the mushroom cloud of the Trinity test — whether the explosion might not trigger runaway combustion of Earth’s atmosphere.

The RHIC and LHC have taken much less on trust. But of course the mere acknowledgement of the risks that is implied by commissioning studies to quantify them, along with the fact that it is rarely possible to assign any such risk a strictly zero probability, must itself fuel public concern. And it is well known to risk-perception experts that we do not have the ability to make a proper rating of very rare but very extreme disasters, even to the simple extent that we feel mistakenly safer in our cars than in an aeroplane.

That is why Kapusta’s conclusion that “physicists must learn how to communicate their exciting discoveries to non-scientists honestly and seriously”, commendable though it is, can never provide a complete answer. We need to recognize that these fears have a mythic dimension that rational argument can never wholly dispel.

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Geochemists Challenge Key Theory Regarding Earth's Formation

Munir Humayun with Inductively Coupled Plasma Mass Spectrometer (ICP-MS) in the new Plasma Analytical Facility in the Geochemistry section of the National High Magnetic Field Laboratory. (Credit: Image courtesy of Florida State University)

Working with colleagues from NASA, a Florida State University researcher has published a paper that calls into question three decades of conventional wisdom regarding some of the physical processes that helped shape the Earth as we know it today.

Munir Humayun, an associate professor in FSU's Department of Geological Sciences and a researcher at the National High Magnetic Field Laboratory, co-authored a paper, "Partitioning of Palladium at High Pressures and Temperatures During Core Formation," that was recently published in the peer-reviewed science journal Nature Geoscience. The paper provides a direct challenge to the popular "late veneer hypothesis," a theory which suggests that all of our water, as well as several so-called "iron-loving" elements, were added to the Earth late in its formation by impacts with icy comets, meteorites and other passing objects.

"For 30 years, the late-veneer hypothesis has been the dominant paradigm for understanding Earth's early history, and our ultimate origins," Humayun said. "Now, with our latest research, we're suggesting that the late-veneer hypothesis may not be the only way of explaining the presence of certain elements in the Earth's crust and mantle."

To illustrate his point, Humayun points to what is known about the Earth's composition.

"We know that the Earth has an iron-rich core that accounts for about one-third of its total mass," he said. "Surrounding this core is a rocky mantle that accounts for most of the remaining two-thirds," with the thin crust of the Earth's surface making up the rest.

"According to the late-veneer hypothesis, most of the original iron-loving, or siderophile, elements" -- those elements such as gold, platinum, palladium and iridium that bond most readily with iron -- "would have been drawn down to the core over tens of millions of years and thereby removed from the Earth's crust and mantle. The amounts of siderophile elements that we see today, then, would have been supplied after the core was formed by later meteorite bombardment. This bombardment also would have brought in water, carbon and other materials essential for life, the oceans and the atmosphere."

To test the hypothesis, Humayun and his NASA colleagues -- Kevin Righter and Lisa Danielson -- conducted experiments at Johnson Space Center in Houston and the National High Magnetic Field Laboratory in Tallahassee. At the Johnson Space Center, Righter and Danielson used a massive 880-ton press to expose samples of rock containing palladium -- a metal commonly used in catalytic converters -- to extremes of heat and temperature equal to those found more than 300 miles inside the Earth. The samples were then brought to the magnet lab, where Humayun used a highly sensitive analytical tool known as an inductively coupled plasma mass spectrometer, or ICP-MS, to measure the distribution of palladium within the sample.

"At the highest pressures and temperatures, our experiments found palladium in the same relative proportions between rock and metal as is observed in the natural world," Humayun said. "Put another way, the distribution of palladium and other siderophile elements in the Earth's mantle can be explained by means other than millions of years of meteorite bombardment."

The potential ramifications of his team's research are significant, Humayun said.

"This work will have important consequences for geologists' thinking about core formation, the core's present relation to the mantle, and the bombardment history of the early Earth," he said. "It also could lead us to rethink the origins of life on our planet."

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Prepping Robots to Perform Surgery

WHAT do you call a surgeon who operates without scalpels, stitching tools or a powerful headlamp to light the patient’s insides? A better doctor, according to a growing number of surgeons who prefer to hand over much of the blood-and-guts portion of their work to medical robots controlled from computer consoles.

Many urologists performing prostate surgery view the precise, tremor-free movements of a robot as the best way to spare nerves crucial to bladder control and sexual potency. A robot’s ability to deftly handle small tools may lead to a less invasive procedure and faster recovery for a patient. Robots also can protect surgeons from physical stress and exposure to X-rays that may force them into premature retirement.

A generation ago, the debate in medicine was whether robotics would ever play a role. Today, robots are a fast-growing, diversifying $1 billion segment of the medical device industry. And Wall Street has just two questions for the industry: How far is this going, and how fast?

There are no simple answers, of course, but it is remarkable how often Frederic H. Moll comes up in any discussion.

Dr. Moll, 56, is a soft-spoken man who can look uncomfortable on stage. Yet his role in founding Intuitive Surgical, the company that now dominates the field, and his current involvement with three other robotics companies, has kept him in the sights of investors, health care providers and fellow entrepreneurs.

He’s now best known as chief executive of Hansen Medical, a publicly traded robotics company focused on minimally invasive cardiac care. But he’s also an investor in and a board member of Mako Surgical, an orthopedics robotics company that recently went public, and he is a co-founder and chairman of Restoration Robotics, a start-up company focused on cosmetic surgery.

“Anyone who meets Fred will remember him,” says Maurice R. Ferré, the chief executive of Mako, which makes a drill that shuts off if a knee surgeon starts removing too much bone. “He will cut you off to ask technical questions and drives right to what’s important. A lot of people are looking at the Mako story because Fred’s involved.”

Despite Wall Street’s growing fondness for medical robotics companies, plenty of health care providers and insurers are cautious. They’re looking for more evidence that robotics improves outcomes for patients at a cost hospitals can absorb. Many still wonder whether it is more about marketing than medical progress.

Winifred Hayes, chief executive of Hayes Inc., a health care technology consulting firm in Lansdale, Pa., says that most clinical data doesn’t support contentions that patients fare better with robotic surgery. Most hospitals and clinics are losing money or making poor returns on their robots, she says.

“The real story is that this is a technology that has been disseminated fairly widely prematurely,” she says.

Even so, interest in robotics remains strong, and the arc of Dr. Moll’s own career has landed him at the intersection of tussles between business and medicine.

His parents were both pediatricians, and he sailed through medical school. But during his surgical residency at the Virginia Mason Medical Center in Seattle in the early 1980s, he found the ailments of patients less compelling than the shortcomings of the tools that surgeons used to treat them.

“I was struck by the size of the incision and injury created just to get inside the body,” Dr. Moll says. “It felt antiquated.”

So he obtained a leave of absence to study whether the long slender cutting tools he had seen gynecologists use in sterilization surgery on women could be adapted to gall bladder removal.

“We saved the spot for 10 years, but he never came back,” said Dr. John A. Ryan Jr., then head of the surgical training at Virginia Mason.

Indeed, Dr. Moll had left Seattle for Silicon Valley, where he spent the next decade creating and selling two medical equipment businesses while getting a graduate degree in management at Stanford. He walked away from the two deals with about $7.5 million. That was modest by the standards of, say, Paul Allen and Bill Gates, the Microsoft founders who were his schoolmates at the exclusive Lakeside School in Seattle in the early 1970s, but Dr. Moll had found his calling.

He says his immersion in the entrepreneurial life cost him his marriage; he remembers once telling his wife he was so busy he couldn’t talk to her for a month. But it also set him on a course to become a pioneer in the emerging field of medical robotics.

ROBOTS revolutionized manufacturing during the 1980s, on the back of advances in computing, motion controls and software design.

Visionaries like Dr. Richard M. Satava, who oversaw federally funded medical robotics research at the time, predicted that robots would eventually be able to operate as precisely as the world’s greatest surgeons and far more tirelessly, perhaps even in remote locations, through satellite links.

A project that Dr. Satava’s group financed to build a remotely controlled medical robot for the battlefield caught Dr. Moll’s eye in 1994.

Dr. Moll saw scant commercial potential for long-distance surgery, but he became convinced that the technology, being developed by SRI International, a nonprofit contract research firm in Palo Alto, Calif., could be adapted to make routine surgery much less invasive in the hands of civilian surgeons.

He took the idea to his employer, Guidant, a medical device company. Guidant decided that robotic surgery was too futuristic and too risky, so Dr. Moll rounded up backers, resigned, and in 1995, founded Intuitive Surgical.

A competitor, Computer Motion, had a head start using technology developed for the space program. But Intuitive Surgical had an experienced management team headed by Lonnie M. Smith. Mr. Smith was recruited from Hillenbrand Industries, where he oversaw health care companies, to become chief executive in 1997, leaving Dr. Moll to concentrate on strategic development.

Intuitive went public in 2000 at $9 a share. (Dr. Moll’s stake at the time was worth roughly $13.5 million, and he still owns a significant number of shares.) In 2003, it acquired Computer Motion, eliminating both patent wars and the competing design. Since then, soaring sales and profits have laid to rest any Wall Street doubts that robots could be commercially successful.

The company earned $144.5 million last year on sales of $600.8 million. Based on first-quarter results that were better than expected, Intuitive forecasts that sales will grow 42 percent this year, to $853.2 million. Its stock, which traded at $42.42 three years ago, closed Friday at $290.03 a share.

The company prospered by proving that robots could deftly handle rigid surgical tools like scalpels and sewing needles through small incisions in a patient’s skin. In prostate surgery, it is rapidly becoming unusual for a urologist to operate without using one of Intuitive’s da Vinci robots, which sell for $1.3 million, on average. Each also generates hundreds of thousands of dollars more in annual revenue from service contracts and attachments that must be replaced after each procedure. Intuitive is now marketing the da Vinci to other specialists, including gynecologists and heart surgeons.

Intuitive’s success has not put to rest questions about how many hospitals and clinics can afford robots. The da Vinci and the CyberKnife, a precision radiation robot from Accuray to treat tumors, are featured in hospital ads to attract patients, but it is hard for hospitals to get extra reimbursement from insurers for using them.

However, hospitals that have been leaders in adopting robotic technology say they are content to just break even for now, because the investment is partly about attracting surgeons who want to be leaders in research and training.

“If you are looking at the future, it’s hard to envision a hospital not offering robotics,” said Robert Glenning, chief financial officer at the Hackensack University Medical Center in New Jersey, which has bought five da Vinci’s and has a sixth on loan from Intuitive Surgical that is used to train visiting doctors.

DR. MOLL left Intuitive in 2002 to pursue a more ambitious concept at Hansen Medical: robots that manipulate the tips of thin, flexible catheters that doctors insert deep in the heart. If he succeeds, the Sensei robotic systems from Hansen, costing about $675,000, may become the go-to tools for treating many circulatory problems.

Relations between the two companies were rocky in the first year because of disagreements over the breadth of Intuitive’s patents. Eventually, the two signed an intellectual property agreement that gives Intuitive a 3 percent royalty on Hansen sales. With Intuitive expanding into cardiac care, the two may eventually collide in some procedures.

Doctors who use catheters generally gain access to the circulatory system through a small incision in the major veins that run through the thigh or arm. Both the makers of rigid tools and the catheter companies are competing in another fast-developing field of “scarless” therapy involving operations performed through the urinary tract and other natural openings.

Dr. Moll is betting that flexible tools like those that work with the Sensei will dominate as this movement matures. He took a team of four Hansen employees to India last summer for a series of surgeries testing whether kidney stones could be removed by using a robotic catheter. Dr. Inderbir S. Gill, a urologist from the Cleveland Clinic who led the research, said that Dr. Moll had followed every case for four days.

“He was at the console like a mother hen even though he wasn’t allowed to touch it,” said Dr. Gill, who received stock in Hansen for work on the research and is planning a clinical trial.

Like Intuitive in its early days, Hansen faces a competitor that got an earlier start. Stereotaxis, based in St. Louis, makes the Niobe, a robot that generates magnetic fields around the patient. By manipulating the magnetic field from Niobe’s computer, doctors can manage the movements inside the patient of its customized magnetic catheters.

The Sensei manipulates a Hansen catheter called Artisan, a hollow sheath through which doctors can deploy smaller catheters. Sensei and Artisan were approved by federal regulators last May for use with catheters that map electrical activity in the heart. While mapping is currently the only job for which Hansen can actively market the Sensei, the robot’s real focus is to combine mapping with minimally invasive treatments to halt electrical short circuits in the heart that cause it to beat abnormally.

Fans include Dr. Davendra Mehta, chief arrhythmia specialist at Mount Sinai Medical Center, who last fall became the first doctor in New York City to order a Sensei. “This is like power steering versus conventional steering,” said Dr. Mehta during a recent procedure.

Using the robot also lets Dr. Mehta avoid spending up to five hours a day wearing a lead vest to limit his exposure to the X-rays when monitoring the catheter’s location in a patient.

THE potential appeal of the Sensei may be obvious. But with just 23 systems installed at the end of March, the competition from Stereotaxis and doubts among many health care providers about whether robots are worth the expense, Dr. Moll has plenty of obstacles ahead.

Still, he and his team members took Hansen public in November 2006, and received approval from regulators in Europe and the United States to market the Sensei. In April, Hansen raised $39.4 million in a secondary stock offering despite Wall Street’s gloomy outlook on the economy. Hansen also has an agreement with St. Jude Medical, the heart device company that is a leader in 3-D heart mapping systems, for co-marketing of technologies.

Dr. Moll said Hansen, based in Mountain View, Calif., should become profitable by the end of next year, two and a half years sooner than Intuitive crossed that threshold. Hansen’s volatile stock, which hit a peak of $39.32 in October before tumbling to $13.48 in March, now trades at $18.54 a share after the company reported better-than-expected first-quarter results on Thursday. Hansen sold eight new robots in the quarter, producing revenue of $6.2 million, and operating losses narrowed.

Even while juggling all of this, Dr. Moll is serving as chairman of Restoration Robotics, a start-up he has financed that aims to apply robotics to hair replacement surgeries for bald men.

Dr. Moll says robotics will ultimately advance on still other fronts, largely because it can help doctors of varying ability perform at the level of the world’s top surgeons.

“The public has no idea of the extent of difference between top surgeons and bad ones,” he said. “Robots are good at going where they are supposed to, remembering where they are and stopping when required.”

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Quantum Vision Lets Birds See the Magnetic Field

Magneticvisionbird_2 Birds' ability to navigate huge distances while migrating has always been a source of natural wonder, and totally sweet long panning shots for nature documentaries. But now it seems that the avian autopilot is of interest to science, and possibly the X-Men - because the birds might have QUANTUM MAGNO-VISION.

It's accepted that our frequent-flyer feathered friends must be accessing the Earth's magnetic field somehow, but the little question of "How?" remained unanswered for a long time. A step towards answering that came forty years ago with the discovery of cryptochromes in bird eyes. Cryptochromes, as well as being terrific scorers in Scrabble, are a class of light sensitive chemicals which allow plants and animals to detect blue light. Of course, that just changes the question from "How?" to "How do the cryptochromes do it?" Recent research finally has some ideas for how this chemical not only allows you to see the wide blue sky, but the vast magnetic compass that runs through it.

Both the current theories are based on the reaction of cryptochromes to blue light. An incident photon creates a radical-ion pair in the bird's retina (one molecule with one too many electrons, and one too few, so both are electrically charged). Professor Hore of the University of Oxford proposes that these charged particles can be pulled apart by an applied magnetic field. While actual cryptochromes are quite hard to get hold of, a similar synthetic molecule known as a carotenoid-porphyrin-fullerene triad (or CPF for people who don't want to spend ten minutes saying its name) was examined by his team. By shining blue light on a chemical solution and applying a magnetic field, he was able to create different concentrations of radicals and ions in different parts of the solution. If birds can detect this chemical imbalance (and most of biology is just moving chemicals around), then they have their magnetic compass.

Professor Iannis Kominis of the University of Crete has a different idea. He argues that when the blue photon triggers the creation of radical-ion pairs, the orientation of the exchanged electrons are affected by the Earth's magnetic field. The reaction when the radical and ion recombine to form neutral molecules is thus affected by the direction of the applied field. One apparent flaw is that the time the radical-ion pair is separated is too short to allow the magnetic field to change things, but he answers this with a real-world example of quantum craziness - the Quantum Zeno effect. The very fact that the pair separation is constantly being checked by the bird prevents it from recombining as quickly as normal. This is a known quantum effect, an utterly scientific version of "a watched pot never boils" - the more you observe such a statistical quantum process, the slower it gets, because each time you check you redefine the particle as absolutely being where it is. It's like driving the family car, but every time a kid asks "Are we there yet?" you get teleported back to where you started.

Incredibly, this is exactly the effect used in the very latest atomic magnetometers, the pinnacle of humankind's ability to detect tiny magnetic fields. And it seems avians have had them in their eyeballs all along. Some would point out that finding such sophisticated systems inside an animal would be evidence of an intelligent creator. To which the answer is, of course, that if there is any such creator he went to a lot of effort creating things which could be decoded by scientific experiment and analysis. Instead of just putting all the answers in a book.

Posted by Luke McKinney.

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Is Wireless Power Closer Than We Think?

A few years back, Marin Soljačić was driven from bed by the insistent beeping of his mobile phone. But it wasn’t beeping for him to answer it, it was beeping for him to plug it in. Since that night, the assistant professor of physics at MIT, has been thinking about ways to start his phone charging as soon as he enters his home - without the need for plugs or wires.

Jennifer Chu at Technology Review writes that Soljačić considered using radio waves, but found that most of their energy would be lost in transmission. Targeted methods like lasers require a clear line-of-sight and could be dangerous for anything in their way. According to Chu, he eventually settled on a phenomenon called magnetic resonance coupling, in which two objects tuned to the same frequency exchange energy strongly but interact only weakly with other objects.

“A classic example is a set of wine glasses, each filled to a different level so that it vibrates at a different sound frequency. If a singer hits a pitch that matches the frequency of one glass, the glass might absorb so much acoustic energy that it will shatter; the other glasses remain unaffected.”

Now, Soljačić and his team have successfully demonstrated the use of magnetic resonance coupling to power a 60 watt light bulb from a distance of roughly two meters - and through a thin wall.

The most effective setup, thus far, transfers power over a distance of two meters with about 50 percent efficiency. The team is looking at other materials to decrease coil size and boost efficiency. “While ideally it would be nice to have efficiencies at 100 percent,” says Soljačić. “So realistically, 70 to 80 percent could be possible for a typical application.”

While some wireless power technologies have emerged in the marketplace, Soljačić’s technique differs in that it might one day enable devices to recharge automatically, whenever they come within range of a wireless transmitter.

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Pollution Sends Men Bald

Men living in polluted areas are more likely to go bald than those breathing cleaner air, a new study suggests.

The ground breaking research, by academics at the University of London, has linked the onset of male pattern baldness, to environmental factors, such as air pollution and smoking.

The scientists believe toxins and carcinogens found in polluted air can stop hair growing by blocking mechanisms that produce the protein from which hair is made. Baldness is known to be hereditary, but the new research suggests that environmental factors could exacerbate hair loss.

It raises the hope that scientists may be able to develop treatments for balding men, with topical creams that are able to combat the effects of pollution on hair follicles.

Mike Philpott, from the school of medicine at Queen Mary University of London, said: "We think any pollutant that can get into the bloodstream or into the skin and into the hair follicle could cause some stress to it and impair the ability of the hair to make a fibre.

"There are a whole host of carcinogens and toxins in the environment that could trigger this. It suggests that if you stop smoking or live in an area with less air pollution, you may be less predisposed to hair loss."

The study, recently published in the Journal of Investigative Dermatology, involved removing hair follicles from balding men and then studying the samples in laboratories.

The team noted disruption in the process of hair growth, caused by oxidative stress, which destroys cells and is made worse by the effects of smoking and air pollution.

Prof Philpott added: "There is an inherited basis to hair loss, but we are have now identified environmental factors that are important too."

The team plan to conduct further tests to pinpoint precise sources which may cause baldness, including trying to grow hair in different environments that are rich in nicotine and other pollutants found in air.

Nilofer Farjo, a hair transplant doctor involved in the research, added: "This may lead to new methods of treating genetic hair loss. The research suggests that environmental factors like smoking and air pollution contribute to hair loss because they introduce elements that are harmful to the normal mechanisms by which the cells work.

"There's undoubtedly genetics involved as well, but now we know there are environmental factors too. If you live in a place with cleaner air, you might be at less risk."

According to the British Association of Dermatologists, hereditary hair loss, or androgenetic alopecia, is responsible for 95 per cent of hair loss and is seen in men and women.

In men, where is it is also known as male pattern baldness, it involves the progressive thinning of hair along the hair line. In women, it causes the hair to thin on the crown of the head and tends to be less noticeable.

Hair loss can begin as early as the teens, and by the age of 35, almost 40 percent of men and women show some degree of hair loss.

The human head comes equipped with 100,000 tiny hair follicles, from each of which grow a single hair.

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