Scientists to map Fukushima nuclear hotspots with cosmic radiation.


High-energy particles called muons created by cosmic rays striking the Earth's atmosphere could provide an X-ray-style image of the damage to the Fukushima Daiichi nuclear plant after the 2011 tsunami-related meltdown in Japan.(Image from nsf.gov / J. Yang)High-energy particles called muons created by cosmic rays striking the Earth’s atmosphere could provide an X-ray-style image of the damage to the Fukushima Daiichi nuclear plant after the 2011 tsunami-related meltdown in Japan.

Japanese scientists say they have successfully completed a pilot program that allows them to use cosmic rays to determine the location of nuclear fuel inside the damaged Fukushima nuclear plant.

“The technology enables you to find where nuclear fuel is anywhere in the world,” Fumihiko Takasaki, a researcher at the High Energy Accelerator Research Organisation (KEK), told AFP news agency.

The experiment – using a technique known as muon scattering radiography – had been running at a disused nuclear plant in Ibaraki between from February 2012 until last month.

Tiny, high-energy particles called muons are beamed down from space and pass through most materials, including human bones, concrete, and water. They form a consistent stream, with about 1000 moving through one square foot of air on Earth every minute.

While some substances only slightly alter their path, a few block them altogether – particularly the uranium and plutonium used as nuclear fuel. The deflections as a result of these encounters are specific, consistent, and well known to scientists.

By measuring them, they can see an outline of substances impeding the muons, and create a three-dimensional map.

Two large muon detectors, illustrated here, could operate to track the high-energy particles called muons entering and leaving one of the Fukushima reactors.(Image from Los Alamos National Laboratory)Two large muon detectors, illustrated here, could operate to track the high-energy particles called muons entering and leaving one of the Fukushima reactors.(Image from Los Alamos National Laboratory)

Muon scattering radiography has existed since the 1960s. It has been used to map the insides of volcanoes, to examine if there are tunnels underneath ancient pyramids, and to scan cargo for potential nuclear contraband.

But there was never a need to develop a detector to clean up a nuclear site – until the Fukushima plant was devastated by the devastating tsunami and earthquake on the eastern coast of Japan in March 2011.
With much of the plant covered in debris or submerged under water, it is difficult and dangerous to enter and find out exactly where the deformed remains of the melted down reactors remain.

At the same time, fuel from them keeps mixing with groundwater, creating a constant leak of radioactive water that plant operator TEPCO is struggling to contain.

With the clean-up bill already in excess of US$30 billion – with $50 billion more expected to be spent on pollution removal, and another $15 billion on decommissioning the reactors – TEPCO invested in studying the possibility of using muon scattering radiography two years ago.

This handout picture taken by Tokyo Electric Power Co. (TEPCO) on November 27, 2013 shows review mission members of the International Atomic Energy Agency (IAEA), led by Juan Carlos Lentijo, inspecting a spent fuel pool at the crippled Tokyo Electric Power CO.(AFP Photo / TEPCO)This handout picture taken by Tokyo Electric Power Co. (TEPCO) on November 27, 2013 shows review mission members of the International Atomic Energy Agency (IAEA), led by Juan Carlos Lentijo, inspecting a spent fuel pool at the crippled Tokyo Electric Power CO.(AFP Photo / TEPCO)

Scientists from KEK joined with the University of Tokyo, University of Tsukuba, Tokyo Metropolitan University, and some American colleagues to create a functioning detector.

Takasaki has said that just five detectors placed around the stricken plant for two months could create an accurate representation of where its most radioactive and dangerous elements are located.

However, he claims that TEPCO has not yet officially confirmed that it will use the technology it is being offered.

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Mosquito-Borne Chikungunya Virus Arrives In Americas.


The virus can cause debilitating joint pain that can last for weeks, and sometimes years.

The Aedes aegypti mosquito is now spreading the chikungunya virus in the Caribbean.

CDC

A potentially debilitating African virus has now officially made its way to the Americas, and is being spread between people by mosquitoes in the Caribbean. From early December to mid-January, the chikungunya virus had infected at least 200 people, epidemiologists say. But in the last week alone, another 498 confirmed cases have been reported, for a total of around 700. Not exactly happy Friday news.

The virus is not usually fatal, though, with 1 death in every 1,000 cases, and then usually only in the elderly or immune-compromised. But you still don’t want to get it, as it’s known for debilitating symptoms, especially joint pain, that can last for weeks, and, rarely, for months to years,according to the World Health Organization. It often causes fever and other symptoms including headache, muscle pain, nausea, fatigue and rash. And there is no vaccine or medicine to treat it.

You can take steps to avoid it, though: the Centers for Disease Control and Preventionrecommends wearing insect repellant to avoid being bitten if you travel to one of the islands where it has been reported so far, including Saint Martin, Martinique, Guadeloupe, Saint Barthelemy, and the British Virgin Islands. But it has already spread since being detected on Saint Martin last month, and officials worry it could make its way throughout the Caribbean, and to the United States.

It is known for explosive outbreaks and has reached “epidemic proportions,” causing “considerable morbidity and suffering,” according to WHO. It is now found in more than 40 countries, after originating in Tanzania in the early 1950s. The name means derives from a word in the Kimakonde language which means “to become contorted” and describes the stooped appearance of sufferers with joint pain, WHO noted. Nearly 2 million cases have been reported in South Asia since 2005.

It’s only the latest arbovirus (or arthropod-spread pathogen) to arrive in the Americas, and illustrates that we are all vulnerable to the spread of these diseases, thanks in part to globalization. Other famous examples include the West Nile virus and dengue fever. Both dengue and the chikungunya virus are spread by the Aedes aegypti mosquito, and symptoms of both viruses appear similar, making detection of chikungunya more difficult.

Stephen Hawking says there are no black holes.


At least, not as we’ve defined them. In a new paper, Hawking says that one of the defining features of black holes — the complete inability of even light to escape — may not hold true.

Stephen Hawking says there are no black holes

“The absence of event horizons mean that there are no black holes — in the sense of regimes from which light can’t escape to infinity,” writes Hawking, in a new paper. In other words, the notion that black holes have an event horizon, which prevents anything from escaping ever, is wrong.

Hawking posted the paper, titled “Information Preservation and Weather Forecasting for Black Holes” up on arXiv, but it hasn’t yet gone through peer review.

So what exactly does all this mean for theories about how black holes work? The New Scientisthas a terrific look at some of the questions raised by the paper, and how to answer them:

It’s yet another quantum versus relativity showdown!

Indeed. Firewalls mean that one of the two theories is wrong, so physicists have been scrambling to find a compromise that doesn’t produce these flaming problems. Now Hawking has waded in and says the solution is to give up the very thing that makes black holes so intriguing – the event horizon.

Wait a minute… does that mean you could actually escape from a black hole?
Potentially, although you would probably need to be travelling at the speed of light. “The absence of event horizons means that there are no black holes – in the sense of regimes from which light can’t escape to infinity,” writes Hawking in his new paper, which he posted online earlier this week. Instead, black holes have “apparent horizons”, surfaces which trap light but can also vary in shape due to quantum fluctuations, leaving the potential for light to escape.

Take a deep breath: the stethoscope is dying


That cultural symbol of medics – from Kenneth Williams in Carry On Doctor to Edie Falcon’s Nurse Jackie – is being replaced by cheaper and more accurate ultrasound devices.
Nurse Jackie

If you Google “Hugh Laurie” and “stethoscope”, you will come up with a clutch of stories from February 2012 about how everybody’s favourite pill-popping misanthropic physician is “hanging up his stethoscope” after eight seasons on the hit show House.

This underlines a more general truth: doctors don’t retire, they hang up their stethoscopes. Is there any profession so proverbially connected to one tool of their trade? Will people believe you are a doctor if you don’t wear one?

These questions become topical because the stethoscope is reportedly becoming obsolete, nearly 200 years after it was invented. Is it anything to do with the finding that a third of US stethoscopes used in emergencies were contaminated with methicillin-resistant Staphylococcus aureus (MRSA) bacteria? No, but it probably didn’t help.

Rather, according to this month’s edition of the World Heart Federation’s journal, Global Heart, the stethoscope is being replaced by more accurate and cheaper hand-held ultrasound devices.

Hugh Laurie

Hugh Laurie, who hung up his stethoscope when he left the long-running hit show House.
Upsetting news – at least for popular culture. What is every TV medic – from Kenneth Williams’s Dr Tinkle in Carry On Doctor to Edie Falco’s Nurse Jackie – without a stethoscope? And if, as the Global Heart report suggests, the handheld ultrasound devices that doctors of the future will be using look just like smartphones, how will we be able to tell the medics from the civilians in Casualty or Holby City?But there’s good news. If the stethoscope does become obsolete, it will also spell the end for one excrescence: a T-shirt targeted at medical students saying “Keep calm and carry a stethoscope.”The man who invented the stethoscope nearly 200 years ago was shy. French physician René-Théophile-Hyacinthe Laënnec dreaded placing his ear on the patient’s chest, especially when the patient was a woman. No offence to Laënnec, but his patients probably didn’t care for it either, especially if he had cold and/or especially hairy ears.Shyness is the unsung mother of invention. It’s why Finns at Nokia invented texting (they couldn’t bear face-to-face rejection when proposing dates) and why in 1816 Dr Laënnec came up with his auscultatory prosthesis (initially, a tube).Only later, as TV history tells us, did stethoscopes become more sophisticated. In the 60s, Richard Chamberlain’s Dr Kildare wore a stethoscope from a brand called Thumpy, whose earpieces clipped around the neck. By the time ER came along in the mid-90s, TV medics were wearing them with the tube around the neck like rubberised stoles. “The problem with that,” says a GP acquaintance, “is they look cool but keep falling off.” Only a doctor could use “cool” and “stethoscope” in the same sentence.How fortunate for Laënnec that he died before he could see the sexist uses to which popular culture would put his invention. In the 1957 film Doctor at Large, Dirk Bogarde’s Dr Simon Sparrow uses a stethoscope during an examination of a girl who’s been having chest problems. “Big breaths, Eva.” “Yeth, and I’m only 16.” Oh Lord: if that’s what the stethoscope is going to be used for, it is just as well it is becoming obsolete.

But is it? If we have learned nothing else from Star Trek, it’s that, in the future, physicians – some of them aliens, admittedly – will be using stethoscopes. Who can forget that scene in which Phlox, the Denobulan chief medical officer aboard the Enterprise, treated the Klingon Klaangwhile wearing a (funky, space-agey) stethoscope? Not me. Rumours of the death of the stethoscope may be exaggerated.

Researchers develop new method to control nanoscale diamond sensors


Diamonds may be a girl’s best friend, but they could also one day help us understand how the brain processes information, thanks to a new sensing technique developed at MIT.

A team in MIT’s Quantum Engineering Group has developed a new method to control nanoscale diamond sensors, which are capable of measuring even very weak magnetic fields. The researchers present their work this week in the journal Nature Communications.

The new control technique allows the tiny sensors to monitor how these magnetic fields change over time, such as when neurons in the brain transmit electrical signals to each other. It could also enable researchers to more precisely measure the magnetic fields produced by novel materials such as the metamaterials used to make superlenses and “invisibility cloaks.”

In 2008 a team of researchers from MIT, Harvard University, and other institutions first revealed that nanoscale defects inside diamonds could be used as magnetic sensors.

The naturally occurring defects, known as nitrogen-vacancy (N-V) centers, are sensitive to external magnetic fields, much like compasses, says Paola Cappellaro, the Esther and Harold Edgerton Associate Professor of Nuclear Science and Engineering (NSE) at MIT.

Defects inside  are also known as color centers, Cappellaro says, as they give the gemstones a particular hue: “So if you ever see a nice diamond that is blue or pink, the color is due to the fact that there are defects in the diamond.”

The N-V center defect consists of a nitrogen atom in place of a carbon atom and next to a vacancy—or hollow—within the diamond’s lattice structure. Many such defects within a diamond would give the gemstone a pink color, and when illuminated with light they emit a red light, Cappellaro says.

To develop the new method of controlling these sensors, Cappellaro’s team first probed the diamond with green laser light until they detected a red light being emitted, which told them exactly where the defect was located.

They then applied a microwave field to the nanoscale sensor, to manipulate the  of the N-V center. This alters the intensity of light emitted by the defect, to a degree that depends not only on the microwave field but also on any external magnetic fields present.

To measure  and how they change over time, the researchers targeted the nanoscale sensor with a microwave pulse, which switched the direction of the N-V center’s electron spin, says team member and NSE graduate student Alexandre Cooper. By applying different series of these pulses, acting as filters—each of which switched the direction of the electron spin a different number of times—the team was able to efficiently collect information about the external .

They then applied signal-processing techniques to interpret this information and used it to reconstruct the entire magnetic field. “So we can reconstruct the whole dynamics of this external magnetic field, which gives you more information about the underlying phenomena that is creating the magnetic field itself,” Cappellaro says.

The team used a square of diamond three millimeters in diameter as their sample, but it is possible to use sensors that are only tens of nanometers in size. The diamond sensors can be used at room temperature, and since they consist entirely of carbon, they could be injected into living cells without causing them any harm, Cappellaro says.

One possibility would be to grow neurons on top of the diamond sensor, to allow it to measure the magnetic fields created by the “action potential,” or signal, they produce and then transmit to other nerves.

Previously, researchers have used electrodes inside the brain to “poke” a neuron and measure the electric field produced. However, this is a very invasive technique, Cappellaro says. “You don’t know if the neuron is still behaving as it would have if you hadn’t done anything,” she says.

Instead, the diamond sensor could measure the magnetic field noninvasively. “We could have an array of these defect centers to probe different locations on the neuron, and then you would know how the signal propagates from one position to another one in time,” Cappellaro says.

In experiments to demonstrate their sensor, the team used a waveguide as an artificial neuron and applied an external magnetic field. When they placed the diamond sensor on the waveguide, they were able to accurately reconstruct the magnetic field. Mikhail Lukin, a professor of physics at Harvard, says the work demonstrates very nicely the ability to reconstruct time-dependent profiles of weak magnetic fields using a novel magnetic sensor based on quantum manipulation of defects in diamond.

“Someday techniques demonstrated in this work may enable us to do real-time sensing of brain activity and to learn how they work,” says Lukin, who was not involved in this research. “Potential far-reaching implications may include detection and eventual treatment of brain diseases, although much work remains to be done to show if this actually can be done,” he adds.

Space travel ‘vital to our survival’


The BBC’s Pallab Ghosh speaks to British astronaut Tim Peake as he trains underwater to prepare for working in zero gravity.

The British astronaut who is set to go into space next year has said that learning how to live and work in space will be essential to the survival of our species.

He is due to spend six months on the International Space Station next year.

Major Peake is currently undergoing intensive training in Germany to prepare for the mission.

He will travel on a Soyuz rocket from Baikonur Cosmodrome in Kazakhstan and could eat a meal chosen by the public.

“Whether it’s an asteroid mission or a Moon mission the ultimate aim is the future exploration of the Solar System and get to Mars on a manned mission,” he told BBC News.

“Humanity’s aim is to explore the Solar System, not just for the sake of exploration. I genuinely believe it is for the sake of our own survival in the future.”

“Start Quote

There’s lots of unglamorous work to do. At times we are plumbers, at times we’re electricians. We do all sorts of jobs”

Tim PeakeUk astronaut

Tim Peake will be going to the ISS in November or December next year. He is currently undergoing intensive training at the European Astronaut Centre in Cologne where I caught up with him.

I have met Neil Armstrong, Buzz Aldrin and Chris Hadfield and I wondered how Tim Peake would compare. He came across as incredibly nice and refreshingly normal.

It is because of this that the nation is likely to empathise with him and through his eyes we will witness the wonders of a mission to the International Space Station.

But beneath his easy manner is an ice cool nerve. It was demonstrated most clearly on the day that his mission was announced.

He was quizzed on Newsnight about the value of his mission by Jeremy Paxman. Very few have matched the formidable presenter when he has been in full cry. But Tim Peake handled the grilling with aplomb.

“I was tired before the interview, which I think helped, because it meant I didn’t have the energy to get wound up,” he confided modestly.

Reaching out

I asked Tim whether he would be reaching out to people on the ground and inspiring them as Chris Hadfield had done when he was on the ISS.

“I certainly hope that the mission will have an inspirational effect. But I’ll be doing it my way,” he told me.

British astronaut Tim Peake shows the BBC’s Pallab Ghosh around a detailed mock-up of the International Space Station’s science lab

He wants the nation to be part of his ground control team.

“We are going to get the public involved in naming the mission, designing the (badge) for the mission and doing things like designing a meal for an astronaut for a day that will get cooked and sent up for me to eat,” he said.

The idea behind the meal for Tim is to get people thinking about science through nutrition, minerals and calorific content.

There will be activities involving sport and exercise too.

“Start Quote

It’s easy to dismiss this stuff about ‘Moon, Mars and Beyond’ as Nasa propaganda but they are taking it seriously and I think it really will happen”

I met Tim at the European Astronaut Centre in Cologne.

It is located in the outskirts of the city, in the midst of a desolate industrial complex which seemed to be fading into the grey German drizzle.

The misery of the landscape is blasted away though by the incredible sense of optimism one feels on entering the astronaut training centre. Its vast hall seems like an untidy giant’s play room, strewn with life-sized replicas of parts of the ISS.

Tim grinned at my bemusement and showed me through to where he’ll be working – a true-to-life representation of the Columbus module, which is Europe’s laboratory in space.

Here, he is taught how to take apart a smoke detector and change its filter. Routine maintenance will be a large part of his job.

Only the brave

Tim Peake
Tim Peake: “Humanity’s aim is to explore the Solar System for the sake of our survival”

“There’s lots of unglamorous work to do. At times we are plumbers, at times we’re electricians. We do all sorts of jobs,” he said.

There was a time when all you needed to be an astronaut was to be very brave. Now you need to be able to do much more.

The former helicopter pilot is also learning how to be a scientist. It is hoped that he will be carrying a number of British-led experiments which would include watching how microbes grow in space and creating new types of metal alloys in zero gravity.

The ISS is now the orbiting laboratory it was designed to be but many leading researchers say that the projects that will be undertaken on board won’t be cutting edge.

“It is definitely cutting edge science,” Tim protested. “Some of the things we are doing on the space station are absolutely remarkable. We are finding things about our bodies that we genuinely had no ideas about before”.

The most interesting experiments on board the space station are the astronauts themselves. They are being constantly monitored to investigate the effects of long-term space travel.

Currently astronauts normally don’t spend more than six months on the ISS because of exposure to radiation and bone loss caused by weightlessness.

It is the debilitating effects of long duration space missions that is one of the main obstacles to sending humans to Mars.

But, speaking candidly, Tim told me that among the astronaut corps, there was a firm belief that one among their number would, in the not-too-distant future, journey to another world.

“We are being trained for these kinds of missions on the new launch systems,” he said. “It’s easy to dismiss this stuff about ‘Moon, Mars and Beyond’ as Nasa propaganda. But they are taking it seriously and I think it really will happen.”

‘Oppy’ celebrates 10 years on Mars


Opportunity rover
A birthday “selfie”: Oppy uses its mast cameras to look down on itself

The American space agency (Nasa) is celebrating 10 years of operation for its Opportunity rover on Mars.

The six-wheeled vehicle landed on the planet’s Meridiani plains on 25 January, 2004, at 05:05 GMT.

It has since trundled 38.7km across the surface, studying the local geology and returning over 170,000 images to Earth.

How much longer the rover can continue working in Mars’ harsh environment is unknown, but Nasa is confident it will keep rolling a while yet.

“The rover has some degraded components,” explains John Callas, the manager of the agency’s Mars Exploration Rover Project, which looks after “Oppy”, as it is often called.

Landing
Opportunity was the second rover landed on Mars in the space of three weeks

“The right-front steering actuator is jammed and no longer steers. The same wheel also shows elevated currents, the robotic arm has some arthritis, and two of the scientific instruments no longer function. But in the past year, almost nothing has changed in the health and status of the rover.”

And it continues to deliver impressive research results.

To coincide with the anniversary, Science magazine has just published a paperdetailing Opportunity’s latest discoveries on the rim of the 22km-wide Endeavour Crater.

It has found evidence for clay minerals, which form in rocks that have been substantially altered by water.

In one place, these clays are of an iron-rich variety called smectite. In another location, Opportunity sees an aluminium-rich variety called montmorillonite.

They are contained in what are among the oldest rocks the rover has yet seen on the planet, probably four billion-plus years old.

It is further evidence, says the rover’s deputy principal investigator, Ray Arvidson, that Mars was warmer and wetter in its distant past and had the potential, therefore, to support microbial life.

“If I were there back when this material was being emplaced and altered, and I had my summer house, this is where I would drill to get good drinking water,” he jokes.

Smithsonian showcases Mars rover images

Recent days have produced a fascinating surprise for scientists with the sudden appearance of a small rock in the rover’s field of view.

It has been likened by the team to a jam doughnut (or “jelly donut”) because it has a whitish exterior and a reddish interior.

The rover team thinks the vehicle may have flipped the rock into view as it pirouetted on its wheels. Its chemistry was unexpected, containing a lot of sulphur, manganese and magnesium, says principal investigator Steve Squyres.

“We’re still working this out; we’re making measurements right now. This is an ongoing story of discovery. Mars keeps throwing new stuff at us. And it’s these kind of discoveries that make this mission continue to be the exciting fun thing that it is.”

The road ahead will see Opportunity try to climb a ridge at Endeavour to get to a place dubbed Cape Tribulation. Orbiting satellites have indicated there may be more clays to examine at this location.

The rover project costs about $14m (£8.4m) a year to run. It must endure a review later this year where it must compete with other Nasa missions for ongoing funding.

Given the pressure on the agency’s budget, it is likely that some ventures that are still working will have to be switched off.

“Frankly, all the missions we have are very productive and it would be a shame not to have enough for a continuation of all those missions. But we’ll see how that turns out when we get to the senior review,” says Michael Meyer, the lead scientist on Nasa’s Mars exploration programme.

The twin rover, Spirit, which landed three weeks prior to Opportunity, was declared dead by Nasa in May 2011. It had become stuck in soft sand in 2009, and then eventually ceased communicating with Earth. Engineers think the extreme cold probably damaged many critical components and connections on the robot.

"Pinnacle Island" Rock
Two images taken 12 days apart show the sudden appearance of the “jelly donut”

New solar cell technology captures high-energy photons more efficiently


Scientists at the U.S. Department of Energy’s Argonne National Laboratory and the University of Texas at Austin have together developed a new, inexpensive material that has the potential to capture and convert —particularly from the bluer part of the spectrum—much more efficiently than ever before.

Most simple solar cells handle these bluish hues of the  inefficiently. This is because blue photons—incoming particles of light that strike the solar cell—actually have excess energy that a conventional solar cell can’t capture.

“Photons of different energies kick electrons up by different amounts,” said University of Texas Professor Brian Korgel. “Some photons come in with more energy than the cell is optimized to handle, and so a lot of that energy is lost as heat.”

Because of this limitation, scientists had originally believed that simple  would never be able to convert more than about 34 percent of  to electricity. However, about a decade ago, researchers saw the potential for a single high-energy photon to stimulate multiple “excitons” (pairs of an electron and a positively-charged partner called a “hole”) instead of just one. “This was a very exciting discovery, but we were still skeptical that we could get the electrons out of the material,” Korgel said.

In their study, Korgel and his team used specialized spectroscopic equipment at Argonne’s Center for Nanoscale Materials to look at multiexciton generation in copper indium selenide, a material closely related to another more commonly produced thin film that holds the record for the most efficient thin-film semiconductor. “This is one of the first studies done of multiple exciton generation in such a familiar and inexpensive material,” said Argonne nanoscientist Richard Schaller.

“Argonne’s spectroscopic techniques played a critical role in the detection of the multiexcitons,” Korgel said. “These kinds of measurements can’t be made many places.”

In order to deposit thin films of the nanocrystalline material, the researchers used a process known as “photonic curing,” which involves the split-second heating up and cooling down of the top layer of the material. This curing process not only prevents the melting of the glass that contains the nanocrystals, but also vaporizes organic molecules that inhibit multiple exciton extraction.

Although the study mostly proves that the efficiency boost provided by multiple exciton extraction is possible in mass-producible materials, the major hurdle will be to incorporate these  into actual real-world devices.

“The holy grail of our research is not necessarily to boost efficiencies as high as they can theoretically go, but rather to combine increases in efficiency to the kind of large-scale roll-to-roll printing or processing technologies that will help us drive down costs,” Korgel said.

6 Gross Side Effects Of Chewing Gum .


We know what you’re going to say. “Now you’re taking away my gum, too?!” After all, chewing gum seems like such a harmless—no, even smart—habit. You want something sweet? Pop a stick of gum for less than 5 calories (better than a candy bar, right?). Stressed? Chew a couple sticks of gum (preferable to chewing out a coworker, no?). Feeling hungry? Chomp some gum while you think about your options (as in, hit the brakes before you end up knuckle-deep in the chips). What’s not to like?

How about IBS and junk food binges, just to name a few unwelcome consequences of your gum habit.

Consider the following before you reach for that next stick…

You’ll eat less fruit and more junk food

Chewing gum before a meal is often recommended as a way to reduce hunger and eat less. But a recent study published in the journal Eating Behaviors debunks this belief. The study showed gum chewing not only had no effect on calories consumed, but chewing mint-flavored gum reduced the intake of healthy food (fruit) and increased the likelihood of eating junk food such as potato chips and candy. Researchers believe the minty flavor of the gum gave fruits and vegetables a bitter flavor. Try sipping a cup of green tea before a meal to curb your appetite instead, which can even help you lose weight. (Go gluten-free, don’t eat egg yolks, and over 20 more of the worst diet tips ever.)

It can trigger TMJ

Chewing gum can lead to symptoms of temporomandibular joint disorder (TMJ), which includes jaw pain associated with the chewing muscles and joints that connect your lower jaw to your skull. Ouch. “Overuse of any muscle and joint can lead to pain and problems,” says Don Atkins, DDS, a dentist in Long Beach, California. Many people end up with contracted muscles of the jaw, head, and neck, which can lead to headaches, earaches, or toothaches over time. Eat an apple instead, which satisfies the urge to chew and reduces your risk of cardiovascular disease at the same time.

You could develop GI problems

Irritable bowel syndrome (IBS) is a GI disorder characterized by abdominal pain, cramping, and changes in bowel habits. “Chewing gum can contribute to IBS, as excess air can be swallowed, which contributes to abdominal pain and bloating,” says Patrick Takahashi, MD, chief of gastroenterology at St. Vincent Medical Center, Los Angeles, California. In addition to swallowing air, artificial sweeteners such as sorbitol and mannitol can cause diarrhea in otherwise healthy people.

You’ll rot your teeth

In an effort to avoid the laxative effect of artificially sweetened gum, switching to sugar-sweetened gum may sound logical, but it’s fraught with its own issues. “Sugar-sweetened gum bathes the teeth in sugar and is a source of tooth decay,” says Dr. Atkins.

You’re chewing a sheep by-product

Lanolin, an ingredient found in skincare products, keeps chewing gum soft. It doesn’t sound too bad until you find out it’s a yellow waxy substance secreted by the sebaceous glands of sheep. Known as “wool fat,” lanolin is harvested by squeezing the sheep’s harvested wool between rollers. “In the amounts utilized in chewing gum, it hardly poses a threat to one’s health, although the thought of digesting it may be a bit unsavory,” says Dr. Takahashi. Unsavory indeed.

You’re releasing mercury into your system

Silver fillings known as amalgam dental fillings consist of a combination of mercury, silver, and tin. And research shows that chewing gum can release the mercury from the fillings into your system. The problem? High levels of mercury can cause neurological issues as well as chronic illnesses and mental disorders. Fortunately, the small amount released through dental fillings isn’t likely to harm you, says Dr. Takahashi, as it typically passes easily through your intestinal tract. That said, do you really want metal in your body?

Preventing Cell Death from Infection: Scripps Research Institute Scientists Demonstrate Powerful Method to Find New Therapies


Scientists at The Scripps Research Institute (TSRI) have demonstrated the power of a new drug discovery technique, which allows them to find—relatively quickly and cheaply—antibodies that have a desired effect on cells. The TSRI scientists used the technique to discover two antibodies that protect human cells from a cold virus.

The finding includes the useful insight that the cold virus can be stopped by targeting a key viral enzyme in just the right way. More importantly, the study highlights the broad potential of this discovery method to find new ways to fight infections, cancers and other diseases, and perhaps even aging.

“This method allows you to find antibodies that prevent cell death—in this case virus-induced cell death, but potentially any kind of cell death,” said Richard A. Lerner, the Lita Annenberg Hazen Professor of Immunochemistry and Institute Professor at TSRI. Lerner was the senior author of the study, which is reported online ahead of print on January 16, 2014 by the Cell Press journal Chemistry & Biology.

Bigger Pond, Better Fish

For the past two decades, Lerner and his TSRI laboratory have helped pioneer techniques for discovering antibodies that can be used as therapies or scientific tools. Humira®, now among the world’s top-selling pharmaceuticals, is one of many products that have been discovered using such techniques.

Recently, the Lerner laboratory developed an advanced technique in which hundreds of millions of distinct antibodies are produced artificially within very large cultures of mammalian cells. Scientists can use such a system to swiftly find any antibodies that cause a desired outcome (“phenotype”) in the cells where they reside.

Scientists for decades have applied similar “phenotypic selection” methods to libraries of standard small-molecule compounds. But the antibody libraries that can be used with the new method are orders of magnitude larger, making them much more likely to contain members that can achieve a desired result in cells.

“Small-molecule libraries generally contain only tens to hundreds of thousands of compounds, whereas with this method we can use libraries with more than a billion distinct antibodies,” said Jia Xie, a staff scientist in the Lerner laboratory who was first author of the new study.

The new method gives scientists more power not only to find new antibody-based therapies, but also to discover the biological pathways through which they work—pathways that may turn out to be more easily and cheaply targeted by small-molecule drugs.

Earlier this year, Lerner, Xie and their colleagues reported using the new method to find an antibody that can perform the remarkable trick of turning bone marrow cells into young brain cells, via a previously unknown signaling mechanism.

For the new study, the team set out to do a proof-of-principle selection of antibodies that can bring about a different effect: protecting cells against an otherwise certain death. In this case, the agent of death was a rhinovirus, a respiratory virus that is the most common cause of ordinary colds. This rhinovirus reliably kills HeLa cells, a line of human-derived cells that have long been used in studies of viral infection.

Evolving a Discovery, Round by Round

To begin, the team used harmless lentiviruses to distribute the genes for about 100 million distinct antibodies among a similar number of HeLa cells, and later exposed the cells to the rhinovirus. So lethal was this virus to the HeLa cells that nearly every cell soon died, overwhelmed by the infection despite any protective effect from antibodies they harbored.

To detect a protective effect, Xie and his colleagues knew that he would have to make the selection process less drastic. Thus, for the next test, instead of selecting cells that survived—for none would have survived—they selected cells that showed delayed signs of impending death. The researchers then harvested the antibody genes these cells contained, and distributed them among a fresh set of cells. In this way, they reasoned, the genes for the antibodies that had exerted a protective effect would become more abundant within the cells.

Xie and his colleagues took the cells through three of these selection rounds—each requiring about ten days of working and waiting—but saw dismayingly few signs of progress. “The cells that had been infected with our antibody library still showed marginal to undetectable differences from the control cells,” he said.

Then in the fourth round, the protective antibodies became abundant enough to bring about a dramatic change: almost all the antibody-containing cells survived, whereas all the control cells died.

The protection turned out to come from just two antibodies out of the original pool of roughly 100 million. The team determined that both these antibodies protected the cells by attaching to the 3C protease, a rhinovirus enzyme, in ways that hindered its infection-enabling activity.

In principle, if further tests bear out the protective effects of the two antibodies, then optimized versions of them, or small-molecule drugs that hit the same target, could be developed as treatments for rhinovirus infections.

But Xie noted that the study was mainly about demonstrating the usefulness of this broad new method. “It’s a fast, economical, multi-round selection scheme that enables scientists to identify functional antibodies from an unusually big library,” he said. “As long as we have a way to detect and select a desired phenotype in the test cells, this method lets us fish out the antibodies that can make the phenotype happen.”

The study also shows the power of the new method to illuminate biological pathways that mediate disease—in this case the activity of the rhinovirus 3C protease. Moreover, it offers unprecedented insight into the selection process itself.

“We were able to see at each round what antibodies were being selected and how abundant they were in cells,” Lerner said. “It was like following evolution in a test tube.”

Lerner emphasized that this was the first demonstration of screening for the prevention-of-cell-death phenotype using very large antibody libraries—but it won’t be the last. “People now can use this technique to find antibodies that prevent cell death in a wide variety of situations,” he said.

Other co-authors of the study, “Prevention of Cell Death by Antibodies Selected from Intracellular Combinatorial Libraries,” were Kyungmoo Yea of the Shanghai Institute for Advanced Immunochemical Studies and Hongkai Zhang, Brian Moldt, Linling He and Jiang Zhu of TSRI.