Txchnologist

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Pic of the Day: Holiday Deer

This holiday deer is a beautiful Christmas gift from our microbiology department. It was drawn with live bacteria: S. marcescens, S. aureus and S. epidermidis.

This photo was taken from www.microbeworld.org. Submitted by: bindre Thanks to the author (s): Indre Budvytiene, Stanford Hospital Clinical Microbiology lab

[txchnologist]

How Termites Build Complex Homes Without a Master Plan

by Charles Q. Choi, Inside Science

Termites are tiny insects, but they are capable of moving tons of soil to build giant nests. Now scientists are discovering simple rules these insect architects might follow that could help explain how they build complex homes without a master plan.

Such research could lead to robot swarms that can organize to assemble intricate structures. These findings could also help decipher the rules governing complex systems ranging from blood vessels to neural networks.

Termites can build mounds more than 10 meters high and 15 meters across, home to city-like networks of chambers and tunnels. Previous research suggested these networks possessed a number of features that could not have simply emerged by chance, such as tree-like structures that can help soldier termites easily isolate parts of the nest to defend them better. However, it was uncertain how these insects could build such orderly networks without a blueprint or central supervision.

To learn more about how termites behave, scientists used X-rays to scan and map networks of chambers and tunnels in 12 mounds from three different genuses of African termites — Cubitermes, Thoracotermes and Procubitermes. These mounds varied in shape depending on the termite genus — mushroom shapes for Cubitermes, straight pillars for Thoracotermes, and cones for Procubitermes.

The scientists developed a new model to explain the nature of these networks. In the model, termites are each only aware of their immediate vicinity. A nest starts growing from a single tunnel that ends in a chamber. The rest of the nest then develops from a series of simple rules.

The model suggests that new tunnels can branch out from any chamber, but they are most likely to emerge from the most recently built chambers. Termites mark construction materials with chemicals that dissipate over time, so they can tell if chambers were built recently.

The model also proposes that the direction and length of each new tunnel are random, although termites do not extend tunnels over empty space. Each tunnel ends in a new chamber from which more tunnels can branch. Adjacent chambers are merged together, and tunnels that are used less often are randomly pruned off by sealing them shut.

The scientists compared real termite nests with 500 simulated nests created using their model and simulated nests created using two other models — one involving random pruning of tunnels instead of pruning of less-frequented tunnels, and one involving randomly generated networks of chambers and tunnels. They found their model usually generated better matches for real nests than ones created using the other models when it came to structural qualities such as the shortest paths linking chambers. The scientists detailed their findings Dec. 9 in the journal Physical Review E.

"The new work shows that a rather simple behavioral algorithm where termites only need access to locally available information can lead to this kind of architecture — no need for a central coordinator or an explicit blueprint in the individual," said study co-author Christian Jost, a biological modeler at the University of Toulouse in France.

The researchers identified three qualities of termite nest tunnel networks that could help pinpoint their main functions. Low average distances between any two points inside nests are key for tunnel networks that enable fast, efficient transportation of cargo such as food. Reducing the number of redundant tunnels can help in nest defense, since blocking a tunnel would force invaders to take long detours, and as previously mentioned, tree-like structures for tunnel networks can also help in nest defense.

The scientists found that termite nests prioritized low average distances between areas inside them, suggesting they are optimized for transport instead of defense strategies.

"The benefit of these networks is that it helps them move nutrients and wastes through their colony most efficiently," said physiological ecologist Scott Turner at the SUNY College of Environmental Science & Forestry in Syracuse, New York, who did not take part in this research.

One potential application for this research could be simple rules for swarms of robots to follow in order to build complex architectures.

"Such an algorithm may indeed be inspiring for an engineer who wants to coordinate the action of autonomous robots without central coordination," Jost said.

Complex biological networks often display similar structures. Jost noted that research on termites, where it is easy to observe both individuals and the whole colony, might help shed light on other biological systems.

"The same kind of dynamics, where tunnels give rise to branches that give rise to more branches, help lay out networks of blood vessels and the inside surfaces of our lungs," Turner said.

Other critical matters for termite research to focus on include how the structures the insects build depend on their environments and on interactions between termites, Turner said. "There's just an awful lot we still need to learn about these things," he said.

Top Image: Termite mound, Kakadu National Park, Australia by Flickr user Paul Mannix via photopin (license).

[txchnologist]

Astronauts aboard the International Space Station have already chomped down on lettuce grown in microgravity. Now, they’re trying to grow flowering plants to see how life in space impacts their development. This picture from NASA shows young zinnia seedlings in the station’s growth chamber. The agency says they appear to be larger than their counterparts growing on Earth as comparisons. 

Studying these popular garden plants, which produce bright flowers in a range of colors, will give researchers clues about how they can grow flowering food-producing plants like tomatoes and cucumbers. The zinnias are growing in something aptly called the Veggie facility, which involves hardware and grow lights and media that are meant to lightweight and require no energy besides what’s needed for the lights. Central to the project are seed-containing growth “pillows” that provide nutrients to the plant while minimizing microorganism growth so astronauts won’t need to sanitize the food that comes from them.

[txchnologist]

Need to stick two pieces of pipe together in confined and hazardous industrial settings? Soon there might not be any need to stick a human in there. Instead, just send in the laser-firing robotic snake. 

A UK-based company called OC Robotics has demonstrated that their machine can maneuver through areas with limited access until it arrives at its target. Once there, a rotating head outfitted with a 5-kilowatt fiber laser can cut and weld metal pipes. The company’s robot adds to the growing list of snake-inspired machines in the world, which now includes units working in the medical field, disaster relief and other applications. See the video below.

All gifs created from Youtube video courtesy of OC Robotics.

[txchnologist]

Smart Pill Capsule Could Represent Future of Drug Delivery

by Karin Heineman, Inside Science

A tiny medication capsule could be life-changing for some people.

Most medications are absorbed into the body through the stomach and small intestine before making it to the large intestine.

This is just fine for most people, but becomes a problem for people suffering from inflammatory bowel syndrome or Crohn’s disease -- they need drugs that target the large intestine directly. Scientists at Purdue University in West Lafayette, Indiana may have found a solution: A tiny smart pill that delivers drugs right where patients need it most. Learn more and see the video below.

The smart capsule is a device that will open at a specific location in the gastrointestinal, or GI, tract, according to Babak Ziaie, an electrical engineer at Purdue.

The capsule is about an inch long with two compartments. One side holds the drugs. The other side contains a magnetic switch and an electrical component known as a capacitor that releases an electric charge to power the device.

A patient wears a small magnet, or has one implanted near where their large and small intestine meet.  When the capsule comes within range of the magnet, it triggers the capsule to open and releases the drug.

A simulated digestive tract has been used to test the capsule, and researchers hope to see it move on to human clinical trials soon.  Once the device is perfected, it could help a host of GI-tract problems.

Top Gif: Created from Youtube video courtesy of Inside Science.

[txchnologist]

Machine Learning and Big Data Know it Wasn’t You Who Just Swiped Your Credit Card

by Jungwoo Ryoo, The Conversation

You’re sitting at home minding your own business when you get a call from your credit card’s fraud detection unit asking if you’ve just made a purchase at a department store in your city. It wasn’t you who bought expensive electronics using your credit card – in fact, it’s been in your pocket all afternoon. So how did the bank know to flag this single purchase as most likely fraudulent?

Credit card companies have a vested interest in identifying financial transactions that are illegitimate and criminal in nature. The stakes are high. According to the Federal Reserve Payments Study, Americans used credit cards to pay for 26.2 billion purchases in 2012. The estimated loss due to unauthorized transactions that year was US$6.1 billion. The federal Fair Credit Billing Act limits the maximum liability of a credit card owner to $50 for unauthorized transactions, leaving credit card companies on the hook for the balance. Obviously fraudulent payments can have a big effect on the companies' bottom lines. The industry requires any vendors that process credit cards to go through security audits every year. But that doesn’t stop all fraud.

In the banking industry, measuring risk is critical. The overall goal is to figure out what’s fraudulent and what’s not as quickly as possible, before too much financial damage has been done. So how does it all work? And who’s winning in the arms race between the thieves and the financial institutions?

Gathering the troops

From the consumer perspective, fraud detection can seem magical. The process appears instantaneous, with no human beings in sight. This apparently seamless and instant action involves a number of sophisticated technologies in areas ranging from finance and economics to law to information sciences.

Of course, there are some relatively straightforward and simple detection mechanisms that don’t require advanced reasoning. For example, one good indicator of fraud can be an inability to provide the correct zip code affiliated with a credit card when it’s used at an unusual location. But fraudsters are adept at bypassing this kind of routine check – after all, finding out a victim’s zip code could be as simple as doing a Google search.

Traditionally, detecting fraud relied on data analysis techniques that required significant human involvement. An algorithm would flag suspicious cases to be closely reviewed ultimately by human investigators who may even have called the affected cardholders to ask if they’d actually made the charges. Nowadays the companies are dealing with a constant deluge of so many transactions that they need to rely on big data analytics for help. Emerging technologies such as machine learning and cloud computing are stepping up the detection game.

Learning what’s legit, what’s shady

Simply put, machine learning refers to self-improving algorithms, which are predefined processes conforming to specific rules, performed by a computer. A computer starts with a model and then trains it through trial and error. It can then make predictions such as the risks associated with a financial transaction.

A machine learning algorithm for fraud detection needs to be trained first by being fed the normal transaction data of lots and lots of cardholders. Transaction sequences are an example of this kind of training data. A person may typically pump gas one time a week, go grocery shopping every two weeks and so on. The algorithm learns that this is a normal transaction sequence.

After this fine-tuning process, credit card transactions are run through the algorithm, ideally in real time. It then produces a probability number indicating the possibility of a transaction being fraudulent (for instance, 97%). If the fraud detection system is configured to block any transactions whose score is above, say, 95%, this assessment could immediately trigger a card rejection at the point of sale.

The algorithm considers many factors to qualify a transaction as fraudulent: trustworthiness of the vendor, a cardholder’s purchasing behavior including time and location, IP addresses, etc. The more data points there are, the more accurate the decision becomes.

This process makes just-in-time or real-time fraud detection possible. No person can evaluate thousands of data points simultaneously and make a decision in a split second.

Here’s a typical scenario. When you go to a cashier to check out at the grocery store, you swipe your card. Transaction details such as time stamp, amount, merchant identifier and membership tenure go to the card issuer. These data are fed to the algorithm that’s learned your purchasing patterns. Does this particular transaction fit your behavioral profile, consisting of many historic purchasing scenarios and data points?

The algorithm knows right away if your card is being used at the restaurant you go to every Saturday morning – or at a gas station two time zones away at an odd time such as 3:00 a.m. It also checks if your transaction sequence is out of the ordinary. If the card is suddenly used for cash-advance services twice on the same day when the historic data show no such use, this behavior is going to up the fraud probability score. If the transaction’s fraud score is above a certain threshold, often after a quick human review, the algorithm will communicate with the point-of-sale system and ask it to reject the transaction. Online purchases go through the same process.

In this type of system, heavy human interventions are becoming a thing of the past. In fact, they could actually be in the way since the reaction time will be much longer if a human being is too heavily involved in the fraud-detection cycle. However, people can still play a role – either when validating a fraud or following up with a rejected transaction. When a card is being denied for multiple transactions, a person can call the cardholder before canceling the card permanently.

Computer detectives, in the cloud

The sheer number of financial transactions to process is overwhelming, truly, in the realm of big data. But machine learning thrives on mountains of data – more information actually increases the accuracy of the algorithm, helping to eliminate false positives. These can be triggered by suspicious transactions that are really legitimate (for instance, a card used at an unexpected location). Too many alerts are as bad as none at all.

It takes a lot of computing power to churn through this volume of data. For instance, PayPal processes more than 1.1 petabytes of data for 169 million customer accounts at any given moment. This abundance of data – one petabyte, for instance, is more than 200,000 DVDs' worth – has a positive influence on the algorithms' machine learning, but can also be a burden on an organization’s computing infrastructure.

Enter cloud computing. Off-site computing resources can play an important role here. Cloud computing is scalable and not limited by the company’s own computing power.

Fraud detection is an arms race between good guys and bad guys. At the moment, the good guys seem to be gaining ground, with emerging innovations in IT technologies such as chip and pin technologies, combined with encryption capabilities, machine learning, big data and, of course, cloud computing.

Fraudsters will surely continue trying to outwit the good guys and challenge the limits of the fraud detection system. Drastic changes in the payment paradigms themselves are another hurdle. Your phone is now capable of storing credit card information and can be used to make payments wirelessly – introducing new vulnerabilities. Luckily, the current generation of fraud detection technology is largely neutral to the payment system technologies.

Jungwoo Ryoo is Associate Professor of Information Sciences and Technology at Altoona campus, Pennsylvania State University.

Top Image: via Shutterstock.

[txchnologist]

NASA has revealed a few details about their next-generation spacesuits in a new video that features built prototypes of the two main designs. The focus, according to engineers and designers, is improving mobility, visibility and control over the suit for the astronaut who will eventually don the single-person spacecraft. 

Developers are currently working on two designs, the prototype exploration suit (PXS) and the Z-2. The latter is being built specifically for planet exploration, with heavy boots and lower torso mobility meant to allow more natural walking, said advanced pressure garment technology development lead Amy Ross. The PXS, meanwhile, is being made for space walks. With modifications, it too, could be used to work on the surface of Mars. Learn more and see the video below.

“Prototypes are really important for spacesuit development because you can only do so much in the modeling and analysis world,” said Richard Rhodes, the lead Z-2 engineer. “You really don’t know how well the suit works until you integrate it with a person. You have them walk around and try different tasks.” 

All gifs created from video courtesy of NASA.

[txchnologist]

Researchers at the University of Washington say they’ve gotten computers to make robust 3-D models of celebrities’ faces from only online images. Once built, single images or video can control the model, making the simulated celebrity speak. The model can even be controlled by videos of other people, making a representation of someone like Tom Hanks or Barack Obama say things they have never uttered. 

The team led by computer science and engineering professor Ira Kemelmacher-Shlizerman have advanced their machine learning algorithms, which track and reconstruct faces, to the extent that they can now map one person’s mannerisms and facial expressions onto another.

The work’s goal is to develop virtual three-dimensional models of people to reconstruct interactive historical figures and to give a new dimension to visual communications tools like Skype, Google Talk or FaceTime.

“You might one day be able to put on a pair of augmented reality glasses and there is a 3-D model of your mother on the couch,” said Kemelmacher-Shlizerman. “Such technology doesn’t exist yet — the display technology is moving forward really fast — but how do you actually re-create your mother in three dimensions?”

All gifs created from Youtube video courtesy of Supasorn Suwajanakorn.

[txchnologist]

The Physics of Sliding on Ice

by Gabriel Popkin, Inside Science

For a solid material, ice is strangely slippery. While Olympic skiers and children on a snowy hill may or may not care why their favorite winter activities are physically possible, the question has bedeviled scientists for more than a century. Ice is "one of the most complicated" materials, said physicist Bo Persson of Forschungszentrum Jülich in Germany. "It behaves strangely compared to other materials."

A new study published by Persson in the Journal of Chemical Physics provides a mathematical foundation for hypotheses that a liquid-like form of water on the ice surface accounts for its slickness.

The finding could aid designers of winter sports gear who want to increase sliding on ice, and tire designers who want to minimize it. It could also help experimental scientists who have measured ice friction but have not been able to fully explain their results.

"It is nice to see a solid physical justification of something that we always thought was happening," said Nicolas Spencer, a materials scientist at ETH Zürich and editor of Tribology Letters, a journal focusing on studies of friction.  "It all makes perfect sense to me," he said.

Although humans have harnessed ice's slipperiness for millennia — archaeological evidence for sledding dates back to at least 7,000 B.C., and to 5,000 B.C. for skiing — scientists began studying the phenomenon only in the mid-1800s. The renowned English physicist Michael Faraday noted that blocks of ice put next to each other freeze together, and proposed that liquid that forms on ice's surface and then refreezes was responsible.

Early theories to explain ice's slipperiness suggested that pressure applied to ice causes its surface to melt, creating the liquid layer Faraday observed. These theories relied on one of ice's bizarre properties: Near its freezing point it turns from solid to liquid under pressure, whereas most materials do the opposite. But in most cases pressure, such as from a ski or sled, does not cause nearly enough melting to allow for easy sliding on an icy surface.

Instead, a pair of physicists suggested in the 1930s that friction between ice and another material produces heat that melts the ice's surface, similar to how rubbing your hands together warms them on a cold day. While this observation explained the liquid layer better than pressure melting, it still did not account for why ice is slick even when you stand still on it. So others went back to Faraday's proposal and suggested various molecular-level explanations for a liquid-like layer that forms on ice's surface even below the freezing temperature.

That notion of "premelting" aligns with studies of ice in contact with air. But studying ice under a sliding object is hard, says Persson, because the object prevents scientists from scattering light or other particles that could be used to gather data about the ice's microscopic structure. Scientists have instead measured forces on objects that they push across ice at various speeds, temperatures and pressures, and then tried to infer the molecular details.

In the new study, Persson developed a mathematical model to explain the results of such studies. He found that he could describe many experimental results with a simple equation that relates shear stress — the internal forces that an object experiences in the direction parallel to the frictional force exerted by ice — to ice temperature.

The equation resembles those that physicists use to describe certain kinds of "phase transitions," in which a material goes from one state to another at a certain temperature and pressure. Though bulk ice melting is an abrupt transition from solid to liquid, Persson says his equation suggests that the surface layer instead undergoes a more gradual transition through a state that has properties similar to both solid ice and liquid water, but is not fully either. For instance, the phase could contain disordered ice molecules, rather than the normally ordered crystals found in solid ice.

A state similar to the premelting observed in ice exposed to air could account for the results his equation describes, Persson says. But he stresses that his equation does not describe what happens at the molecular level. "I am not really making any claim in this paper about a microscopic mechanism," he said.

"Persson's paper did a good job of providing possible models that can account for the sliding friction-velocity behavior of ice," wrote Francis Kennedy, a retired engineering professor at Dartmouth College who conducted some of the experiments that Persson attempted to explain mathematically, in an email. But Kennedy added that he finds frictional heating a more convincing molecular-level explanation than premelting.

In order to figure out what is really happening at the molecular level, Persson plans to conduct more lab experiments soon.

Top Image: via Shutterstock.

[txchnologist]

Happy 3D Printing Day

This year we’re thinking small to solve big problems. Steam turbines have already proven to be pivotal in spreading electricity to virtually every home and business. Now, scientists at GE Global Research are working to shrink the machine to fit inside the palm of your hand. If successful, these miniaturized steam turbines could reduce the cost of water desalination by as much as 20 percent — a big step towards increasing access to clean drinking water globally.

Build this badass machine right at home by downloading the files on our Thingiverse page and following the step-by-step assembly instructions.

[txchnologist]

Doublemint Gum Becomes Wearable Motion Sensor

Looking for the inspiration behind what might be the future of wearable tech and body sensors? Look no further than that wad of chewed up bubble gum in your mouth. Researchers at the University of Manitoba in Canada have created a stretchable, wearable strain sensor by combining the rolled sheets of bound carbon atoms called carbon nanotubes with a stick of bubble gum.

Malcolm Xing and his colleagues say the material is sensitive and can accurately detect strains up to 530 percent. They tested it as a body motion sensor, and were able to monitor movement as small as what occurs when a person slowly breathes. It was also capable of reading humidity changes and was cheap to produce.

“Pairing these superb sensing performances with other functional properties, including attachability, foldability and formability, gum sensors promisingly introduce a wide range of potential applications in the human motion detection,” they write in a study published recently in the journal Applied Materials & Interfaces.

The team made the material by chewing up a piece of Wrigley’s Doublemint gum for 30 minutes, washing it in ethanol and water overnight and then adding a solution that contained multiwalled carbon nanotubes. The gum was then folded in the same direction over 500 times to evenly distribute the conductive material. Then they tested it out on different body parts and saw that it reliably provided accurate measurements of strain and humidity changes.

Much of the technology needed to unlock the quantified self, where sensors and computers monitor and analyze a wearer’s daily life and real-time health stats, already exists. One of the sticking points, though, (pun intended) is figuring out the actual interface between the computer and the human. A number of high-profile projects are underway, including researchers making sensors out of flexible polymers, sticky temporary tattoos and smart fabrics. 

Xing and his team say that, at least as far as strain sensing is concerned, their gum-based material might have them all beat. 

“A facile approach to prepare an elastic, attachable, low cost, and conductive membrane was presented which can be efficiently used for sensing muscle and joint motions,” they conclude. “Since the gum sensor can be patterned into various forms, it has wide applications in miniaturized sensors and biochips. To the best of our knowledge...the current sensor introduces results superior to those of any other strain sensors.”

Gifs created from videos courtesy of Darabi et al.

[txchnologist]

Can You Think Yourself Into a Different Person?

by Will Storr, Mosaic Science

For years she had tried to be the perfect wife and mother but now, divorced, with two sons, having gone through another break-up and in despair about her future, she felt as if she’d failed at it all, and she was tired of it. On June 6, 2007, Debbie Hampton, of Greensboro, North Carolina, took an overdose. That afternoon, she’d written a note on her computer: “I’ve screwed up this life so bad that there is no place here for me and nothing I can contribute.” Then, in tears, she went upstairs, sat on her bed, and put on a Dido CD to listen to as she died.

But then she woke up again. She’d been found, rushed to hospital, and saved. “I was mad,” she says. “I’d messed it up. And, on top of that, I’d brain-damaged myself.” After Debbie emerged from her one-week coma, her doctors gave her their diagnosis: encephalopathy. “That’s just a general term which means the brain’s not operating right,” she says. She couldn’t swallow or control her bladder, and her hands constantly shook. Much of the time, she couldn’t understand what she was seeing. She could barely even speak. “All I could do was make sounds,” she says. “It was like my mouth was full of marbles. It was shocking, because what I heard from my mouth didn’t match what I heard in my head.” After a stay in a rehabilitation center, she began recovering slowly. But, a year in, she plateaued. “My speech was very slow and slurred. My memory and thinking was unreliable. I didn’t have the energy to live a normal life. A good day for me was emptying the dishwasher.”

It was around this time that she tried a new treatment called neurofeedback. She was required to have her brain monitored while playing a simple Pac-Man-like game, controlling movements by manipulating her brain waves. “Within ten sessions, my speech improved.” But Debbie’s real turnaround happened when her neurofeedback counsellor recommended a book: the international bestseller The Brain that Changes Itself by Canadian psychotherapist Norman Doidge. “Oh my God,” she says. “For the first time it really showed me it was possible to heal my brain. Not only that it was possible, that it was up to me.”

After reading Doidge’s book, Debbie began living what she calls a “brain-healthy” life. That includes yoga, meditation, visualization, diet and the maintenance of a positive mental attitude. Today, she co-owns a yoga studio, has written an autobiography and a guide to “brain-healthy living” and runs the website thebestbrainpossible.com. The science of neuroplasticity, she says, has taught her that, “You’re not stuck with the brain you’re born with. You may be given certain genes but what you do in your life changes your brain. And that’s the magic wand.” Neuroplasticity, she says, “allows you to change your life and make happiness a reality. You can go from being a victim to a victor. It’s like a superpower. It’s like having X-ray vision.”

Debbie’s not alone in her enthusiasm for neuroplasticity, which is what we call the brain’s ability to change itself in response to things that happen in our environment. Claims for its benefits are widespread and startling. Half an hour on Google informs the curious browser that neuroplasticity is a “magical” scientific discovery that shows that our brains are not hard-wired like computers, as was once thought, but like “play-doh” or a “gooey butter cake”. This means that “our thoughts can change the structure and function of our brains” and that by doing certain exercises we can actually, physically increase our brain’s “strength, size and density”. Neuroplasticity is a “series of miracles happening in your own cranium” that means we can be better salespeople and better athletes, and learn to love the taste of broccoli. It can treat eating disorders, prevent cancer, lower our risk of dementia by 60 per cent and help us discover our “true essence of joy and peace”. We can teach ourselves the “skill” of happiness and train our brains to be “awesome”. And age is no limitation: neuroplasticity shows that “our minds are designed to improve as we get older”. It doesn’t even have to be difficult. “Simply by changing your route to work, shopping at a different grocery store, or using your non-dominant hand to comb your hair will increase your brain power.” As the celebrity alternative-medicine guru Deepak Chopra has said, “Most people think that their brain is in charge of them. We say we are in charge of our brain.”

Debbie’s story is a mystery. The techniques promising to change her brain via an understanding of the principles of neuroplasticity have clearly had tremendous positive effects for her. But is it true that neuroplasticity is a superpower, like X-ray vision? Can we really increase the weight of our brain just by thinking? Can we lower our risk of dementia by 60 per cent? And learn to love broccoli?

Some of these seem like silly questions, but some of them don’t. That’s the problem. It’s hard, for the non-scientist, to understand what exactly neuroplasticity is and what its potential truly is. “I’ve seen tremendous exaggeration,” says Greg Downey, an anthropologist at Macquarie University and co-author of the popular blog Neuroanthropology. “People are so excited about neuroplasticity they talk themselves into believing anything.”

For many years, the consensus was that the human brain couldn’t generate new cells once it reached adulthood. Once you were grown, you entered a state of neural decline. This was a view perhaps most famously expressed by the so-called founder of modern neuroscience, Santiago Ramón y Cajal. After an early interest in plasticity, he became sceptical, writing in 1928, “In adult centres the nerve paths are something fixed, ended, immutable. Everything may die, nothing may be regenerated. It is for the science of the future to change, if possible, this harsh decree.” Cajal’s gloomy prognosis was to rumble through the 20th century.

Although the notion that the adult brain could undergo significant positive changes received sporadic attention, throughout the 20th century, it was generally overlooked, as a young psychologist called Ian Robertson was to discover in 1980. He’d just begun working with people who had had strokes at the Astley Ainslie Hospital in Edinburgh, and found himself puzzled by what he was seeing. “I’d moved into what was a new field for me, neuro-rehabilitation,” he says. At the hospital, he witnessed adults receiving occupational therapy and physiotherapy. Which made him think… if they’d had a stroke, that meant a part of their brain had been destroyed. And if a part of their brain had been destroyed, everyone knew it was gone for ever. So how come these repetitive physical therapies so often helped? It didn’t make sense. “I was trying to get my head around, what was the model?” he says. “What was the theoretical basis for all this activity here?” The people who answered him were, by today’s standards, pessimistic.

“Their whole philosophy was compensatory,” Robertson says. “They thought the external therapies were just preventing further negative things happening.” At one point, still baffled, he asked for a textbook that explained how it all was supposed to work. “There was a chapter on wheelchairs and a chapter on walking sticks,” he says. “But there was nothing, absolutely nothing, on this notion that the therapy might actually be influencing the physical reconnection of the brain. That attitude really went back to Cajal. He really influenced the whole mindset which said that the adult brain is hardwired, all you can do is lose neurons, and that if you have brain damage all you can do is help the surviving parts of the brain work around it.”

But Cajal’s prognosis also contained a challenge. And it wasn’t until the 1960s that the “science of the future” first began to rise to it. Two stubborn pioneers, whose tales are recounted so effectively in Doidge’s bestseller, were Paul Bach-y-Rita and Michael Merzenich. Bach-y-Rita is perhaps best known for his work helping blind people ‘see’ in a new and radically different way. Rather than receiving information about the world from the eyes, he wondered if they could take it in in the form of vibrations on their skin. They’d sit on a chair and lean back on a metal sheet. Pressing up against the back side of that metal sheet were 400 plates that would vibrate in accord with the way an object was moving. As Bach-y-Rita’s devices became more sophisticated (the most recent version sits on the tongue), congenitally blind people began to report having the experience of ‘seeing’ in three dimensions. It wasn’t until the advent of brain-scanning technology that scientists began to see evidence for this incredible hypothesis: that information seemed to be being processed in the visual cortex. Although this hypothesis is yet to be firmly established, it seems as if their brains had rewired themselves in a radical and useful way that had long been thought impossible.

Merzenich, meanwhile, helped to confirm in the late 1960s that the brain contains ‘maps’ of the body and the outside world, and that these maps have the ability to change. Next, he co-developed the cochlear implant, which helped deaf people hear. This relies on the principle of plasticity, as the brain needs to adapt to receive auditory information from the artificial implant instead of the cochlea (which, in the deaf person, isn’t working). In 1996 he helped establish a commercial company that produces educational software products called Fast ForWord for “enhancing the cognitive skills of children using repetitive exercises that rely on plasticity to improve brain function,” according to their website. As Doidge writes, “In some cases, people who have had a lifetime of cognitive difficulties get better after only thirty to sixty hours of treatment.”

Although it took several decades, Merzenich and Bach-y-Rita were to help prove that Cajal and the scientific consensus were wrong. The adult brain was plastic. It could rewire itself, sometimes radically. This came as a surprise to experts like Robertson, now a Director of Trinity College Dublin’s Institute of Neuroscience. “I can look back on giving lectures at Edinburgh University to students where I gave wrong information, based on the dogma which said that, once dead, a brain cell cannot regenerate and plasticity happens in early childhood but not later,” he says.

It wasn’t until the publication of a series of vivid studies involving brain scans that this new truth began to be encoded into the synapses of the masses. In 1995, neuropsychologist Thomas Elbert published his work on string players that showed the ‘maps’ in their brain that represented each finger of the left hand – which they used for fingering – were enlarged compared to those of non-musicians (and compared to their own right hands, not involved in fingering). This demonstrated their brains had rewired themselves as a result of their many, many, many hours of practice. Three years later, a Swedish–American team, led by Peter Eriksson of Sahlgrenska University Hospital, published a study in Nature that showed, for the very first time, that neurogenesis – the creation of new brain cells – was possible in adults. In 2006, a team led by Eleanor Maguire at the Institute of Neurology at University College London found that the city’s taxi drivers have more grey matter in one hippocampal area than bus drivers, due to their incredible spatial knowledge of London’s maze of streets. In 2007, Doidge’s The Brain that Changes Itself was published. In its review of the book, the New York Times proclaimed that “the power of positive thinking has finally gained scientific credibility”. It went on to sell over one million copies in over 100 countries. Suddenly, neuroplasticity was everywhere.

It’s easy, and perhaps even fun, to be cynical about all this. But neuroplasticity really is a remarkable thing. “What we do know is that almost everything we do, all our behaviour, thoughts and emotions, physically change our brains in a way that is underpinned by changes in brain chemistry or function,” says Robertson. “Neuroplasticity is a constant feature of the very essence of human behaviour.” This understanding of the brain’s power, he says, opens up new techniques for treating a potentially spectacular array of illnesses. “There’s virtually no disease or injury, I believe, where the potential doesn’t exist for very intelligent application of stimulation to the brain via behaviour, possibly combined with other stimulation.”

Does he agree that the power of positive thinking has now gained scientific credibility? “My short answer is yes,” he says. “I do think human beings have much more control over their brain function than has been appreciated.” The long answer is: yes, but with caveats. First there’s the influence of our genes. Surely, I ask Robertson, they still hold a powerful influence over everything from our health to our character? “My own crude rule of thumb is a 50–50 split in terms of the influence of nature and that of nurture,” he says. “But we should be very positive about that 50 per cent that’s environmental.”

Adding extra tangle to the already confused public discussion of neuroplasticity is the fact that the word itself can mean several things. Broadly, says Sarah-Jayne Blakemore, Deputy Director of London’s Institute of Cognitive Neuroscience, it refers to “the ability of the brain to adapt to changing environmental stimuli”. But the brain can adapt in many different ways. Neuroplasticity can refer to structural changes, such as when neurons are created or die off or when synaptic connections are created, strengthened or pruned. It can also refer to functional reorganisations, such as those experienced by the blind patients of Paul Bach-y-Rita, whose contraptions triggered their brains to start using their visual cortices, which had previously been redundant.

On the larger, developmental scale, there are two categories of neuroplasticity. They are “really different,” says Blakemore. “You need to differentiate between them.” Throughout childhood our brains undergo a phase of ‘experience-expectant’ plasticity. They ‘expect’ to learn certain important things from the environment, at certain stages, such as how to speak. Our brains don’t finish developing in this way until around our mid-20s. “That’s why car insurance premiums are so high for people under 25,” says Robertson. “Their frontal lobes aren’t fully wired up to the rest of their brains until then. Their whole capacity for anticipating risk and impulsivity isn’t there.” Then there’s ‘experience-dependent’ plasticity. “That’s what the brain does whenever we learn something, or whenever something changes in the environment,” says Blakemore.

One way in which science has been exaggerated has been by the blending of these different types of change. Some writers have made it seem as if almost anything counts as ‘neuroplasticity’, and therefore revolutionary and magical and newsworthy. But it’s definitely not news, for example, that the brain is highly affected by its environment when we’re young. Nevertheless, in The Brain that Changes ItselfNorman Doidge observes the wide variety of human sexual interests and calls it “sexual plasticity”. Neuroscientist Sophie Scott, Deputy Director of London’s Institute of Cognitive Neuroscience, is dubious. “That’s just the effect of growing up on your brain,” she says. Doidge even uses neuroplasticity to explain cultural changes, such as the broad acceptance in the modern age that we marry for romantic love, rather than socioeconomic convenience. “That isn’t neuroplasticity,” says Scott.

This, then, is the truth about neuroplasticity: it does exist, and it does work, but it’s not a miracle discovery that means that, with a little effort, you can turn yourself into a broccoli-loving, marathon-running, disease-immune, super-awesome genius. The “deep question”, says Chris McManus, Professor of Psychology and Medical Education at University College London, is, “Why do people, even scientists, want to believe all this?” Curious about the underlying causes of the neuroplasticity craze, he believes it is just the latest version of the personal-transformation myth that’s been haunting the culture of the West for generations.

“People have all sorts of dreams and fantasies and I don’t think we’re very good at achieving them,” says McManus. “But we like to think that when somebody is unsuccessful in life they can transform themselves and become successful. It’s Samuel Smiles, isn’t it? That book he wrote, Self-Help, was the positive thinking of Victorian times.”

Samuel Smiles [Full disclosure: Samuel Smiles is my great-great-uncle] is commonly cited as the inventor of the ’self-help’ movement and his book, just like Doidge’s, spoke to something deep in the population and became a surprise bestseller. The optimistic message Smiles delivered spoke of both the new, modern world and the dreams of the men and women living in it. “In the 18th century, power had all been about the landed gentry,” says historian Kate Williams. “Smiles was writing in the era of the Industrial Revolution, widespread education and economic opportunities offered by Empire. It was the first time a middle-class man could work hard and do well. They needed a formidable work ethic to succeed, and that’s what Smiles codified in Self-Help.”

In the latter part of the 19th century, US thinkers adapted this idea to reflect their national belief that they were creating a new world. Adherents of the New Thought, Christian Science and Metaphysical Healing movements stripped away much of the talk of hard work, insisted upon by the Brits, to create the positive thinking movement to which some believe neuroplasticity has given scientific credence. Psychologist William James called it “the mind-cure movement”, the “intuitive belief in the all-saving power of healthy-minded attitudes as such, in the conquering efficacy of courage, hope, and trust, and a correlative contempt for doubt, fear, worry, and all nervously precautionary states of mind”. Here was the inherently American notion that self-confidence and optimism – thoughts themselves – could offer personal salvation.

This myth – that we can be whoever we want to be, and achieve our dreams, as long as we have sufficient self-belief – emerges again and again, in our novels, films and news, and TV singing competitions featuring Simon Cowell, as well as unexpected crazes like that for neuroplasticity. One previous, and remarkably similar, incarnation was Neuro-Linguistic Programming, which had it that psychological conditions such as depression were nothing more than patterns learned by the brain and that success and happiness were just a matter of reprogramming it. The idea appeared in a more academic costume, according to McManus, in the form of what’s known as the Standard Social Science Model. “This is the idea from the 1990s where, in effect, all human behaviour is infinitely malleable and genes play no role at all.”

But the plasticity boosters have an answer to the tricky question of genes, and their heavy influence over all matters of health, life and wellbeing. Their answer is epigenetics. This is the relatively new understanding of the ways in which the environment can change how genes express themselves. Deepak Chopra has said that epigenetics has shown us that, “regardless of the nature of the genes we inherit from our parents, dynamic change at this level allows us almost unlimited influence on our fate”.

Jonathan Mill, Professor of Epigenetics at the University of Exeter, dismisses this kind of claim as “babble”. “It’s a really exciting science,” he says, “but to say these things are going to totally rewire your whole brain and gene functioning is taking it far too far.” And it’s not just Chopra, he adds. Broadsheet newspapers and academic journals have also been guilty, at times, of falling for the myth. “There have been all sorts of amazingly overhyped headlines. People who have been doing epigenetics for a while are almost in despair, at the moment, partly because it’s being used as an explanation for all sorts of things without any real direct evidence.”

Just as epigenetics doesn’t fulfill our culture’s promise of personal transformation, nor does neuroplasticity. Even some of the more credible-sounding claims are, according to Ian Robertson, currently unjustifiable. Take the one about reducing our risk of dementia by 60 percent. “There is not a single scientific study that has ever shown that any intervention of any kind can reduce the risk of dementia by 60 percent, or indeed by any percentage,” he says. “No one has done the research using appropriate control-group methodologies to show that there is any cause-and-effect link.”

Indeed, the clinical record for many famous treatments that use the principles of neuroplasticity is notably mixed. In June 2015, the Food and Drug Administration in the US permitted the marketing of the latest iteration of Bach-y-Rita’s on-the-tongue ‘seeing’ devices for the blind, citing successful studies. And yet a 2015 Cochrane Review of constraint induced movement therapy – a touchstone treatment for neuroplasticity evangelists that offers improvements in motor function for people who have had a stroke – found that “these benefits did not convincingly reduce disability”. A 2011 meta-analysis of neuroplasticity Godfather Michael Merzenich’s Fast ForWord learning techniques, described to such thrilling effect by Doidge, found “no evidence” that they were “effective as a treatment for children’s oral language or reading difficulties”. This, according to Sophie Scott, goes for other treatments too. “There’s been a lot of excitement about brain-training packages and, actually, big studies of those tend not to show very much effect,” she says. ”Or they show you’ve got better at the thing you’ve practised at, but it doesn’t generalise to something else.” In November 2015, a team lead by Clive Ballard at King’s College London found some evidence that online brain-training games might help reasoning, attention and memory in the over-50s.

It’s perhaps understandable why crazy levels of hope are raised when people read tales of apparently miraculous recovery from brain injury that feature people seeing again, hearing again, walking again and so on. These dramatic accounts can make it sound as if anything is possible. But what’s usually being described, in these instances, is a very specific form of neuroplasticity – functional reorganisation – which can happen only in certain circumstances. “The limits are partly architectural,” says Greg Downey. “Certain parts of the brain are better at doing certain kinds of thing, and part of that comes simply from where they are.”

Another limitation, for the person hoping to develop a superpower, is the simple fact that every part of a normal brain is already occupied. “The reason you get reorganisation after an amputation, for example, is that you’ve just put into unemployment a section of the somatosensory cortex,” he says. A healthy brain just doesn’t have this available real estate. “Because it keeps getting used for what it’s being used for, you can’t train it to do something else. It’s already doing something.”

Age, too, presents a problem. “Over time, plastic sets,” says Downey. “You start off with more of it and space for movement slowly decreases. That’s why a brain injury at 25 is a total different ballgame to a brain injury at seven. Plasticity says you start off with a lot of potential but you’re laying down a future that’s going to become increasingly determined by what you’ve done before.”

Robertson speaks of treating a famous writer and historian who’d had a stroke. “He completely lost the capacity for all expressive language,” he says. “He couldn’t say a word, he couldn’t write. He had a huge amount of therapy and no amount of stimulation could really recover that because the brain had become hyper-specialised and a whole network had developed for the highly refined production of language.” Despite what the currents of our culture might insistently beckon us towards believing, the brain is not Play-Doh. “You can’t open up new areas of it,” says McManus. “You can’t extend it into different parts. The brain isn’t a mass of grey gloop. You can’t do anything you like.”

Even the people whose lives are being transformed by neuroplasticity are finding that brain change is anything but easy. Take recovery from a stroke. “If you’re going to recover the use of an arm, you may need to move that arm tens of thousands of times before it begins to learn new neural pathways to do that,” says Downey. “And, after that, there’s no guarantee it’s going to work.” Scott says something similar about speech and language therapy. “There were dark days, say, 50 years ago, where if you’d had a stroke you didn’t get that kind of treatment other than to stop you choking because they’d decided it doesn’t work. But now it’s becoming absolutely clear that it does, and that it’s a phenomenally good thing. But none of it comes for free.”

Those who over-evangelise emerging disciplines like neuroplasticity or epigenetics can sometimes be guilty of talking as if the influence of our genes no longer matters. Their enthusiasm can make it seem, to the non-specialist, as if nurture can easily conquer nature. This is a story that attracts people in great numbers, to newspapers, blogs and gurus, because it’s one our culture reinforces, and one we want to believe: that radical personal transformation is possible, that we have the potential to be whoever and whatever we want to be, that we can find happiness, success, salvation – all we need to do is try. We are dreamers down to our very synapses, we are the people of the American Dream.

Of course, it’s our malleable brains that have moulded themselves to these rhythms. As we grow up, the optimistic myths of our culture become so embedded in our sense of self that we can lose touch with the fact that they are just myths. The irony is that when scientists carefully describe the blind seeing and the deaf hearing, and we hear it as talk of wild miracles, it’s the fault of our neuroplasticity.

Top image: via Shutterstock.

[txchnologist]

Ultrasound Goes Microscopic to Image Living Organs

A new imaging technique using ultrasound and microscopic bubbles has allowed researchers to peer deep into living organs. The ultrafast microscopy method being pioneered by a research team in Paris can produce images at the rate of more than 500 frames a second. They used it to non-invasively view blood flowing through microscopic vessels in a complete living rat brain, as shown in the image above.

“We anticipate that ultrafast ultrasound localization microscopy may become an invaluable tool for the fundamental understanding and diagnostics of various disease processes that modify the microvascular blood flow, such as cancer, stroke and arteriosclerosis,” Langevin Institute physicist Mickael Tanter and colleagues conclude in a study published last week in the journal Nature. 

Their work could represent a breakthrough in using ultrasound for imaging, which is limited to resolving objects at the millimeter-scale in conventional approaches. At the heart of the problem they cracked is something called the diffraction limit, a fundamental barrier in which objects can’t be resolved if they are smaller than about half the wavelength of the radiation being used to view them.

The group figured out a workaround by injecting bubbles as small as 1 micron in diameter into the animal’s bloodstream. These microbubbles acted as acoustic targets for ultrasound waves to scatter and bounce off. This allowed Tanter and colleagues to conduct super-resolution imaging of microvessels in the brain with a pixel resolution about the size of red blood cells, a tenfold improvement over current methods.

Ultrafast ultrasound localization microscopy, “by removing the diffraction-induced trade-off between resolution and penetration of ultrasound waves, emerges as the first in vivo technique for imaging and quantifying blood flow at microscopic resolution deep into living organs,” the group writes.

Ben Cox and Paul Beard, experts in acoustics at the University College of London who did not take part in the research, said there are still a number of problems to overcome before the advance can be translated to medical use. Before it can be used on a human brain, they say, researchers will need to figure out how to get ultrasound wavelengths through the thick human skull, which naturally attenuates this type of radiation. And the need to introduce microbubbles into the bloodstream could also significantly increase the time it would take to perform scans. 

Still, they write in a commentary accompanying the study, “Super-resolution ultrasound imaging of microvasculature is an exciting prospect. The technique has the potential to substantially advance the study of normal blood-vessel function, as well as disease. Moreover, it might enable doctors to readily identify microvessel-related disorders, such as tumor-related vessel growth and microvascular abnormalities in deep abdominal organs such as the kidneys, and to assess cardiovascular disease.” 

Top Image: Image of the whole brain vasculature at microscopic resolution in the live rat using ultrafast Ultrasound Localization Microscopy: Local density of intravascular microbubbles in the right hemisphere, quantitative estimation of blood flow speed in the left hemisphere. Photo and caption courtesy of ESPCI/INSERM/CNRS.

[txchnologist]

Science Becomes Art: Dance Your Ph.D. Thesis!

Modern dance isn’t typically known for exploring subjects like chemical signaling and defense in brown algal kelps. Avant-garde dancer and choreographer Merce Cunningham wasn’t known for developing statistical tools for biomedical research. 

But that doesn’t mean it can’t be done, and a crop of Ph.D. students and recent graduates is showing how. Just before the holiday last week, Science magazine announced the winners of its eighth annual Dance Your Ph.D. thesis competition. Contestants from the social, physical and life sciences interpreted highly complex concepts through movement, drawing on elements from tango, interpretive dance, hip-hop and other styles.

This year’s winner among 31 entries was Florence Metz, a Ph.D. student at the University of Bern in Switzerland, who took home $1,000 for a dance about her thesis on water policy. Her achievement represents the first time a social scientist has won the overall competition. See the other winners and videos of their dances below.

In the chemistry category, Jyaysi Desai of Germany’s Ludwig Maximilian University won top honors for a dance on molecular mechanisms underlying certain immune system functions. In biology, the University of Sydney’s Pearl Lee won for a dance on how cells interact with the building blocks of the protein elastin. The physics winner was the University of Oxford’s Merritt Moore, who used tango to interpret a thesis on multi-photon states for quantum information applications.

Social science and overall winner: Florence Metz, Ph.D. student, University of Bern, Switzerland

"Do policy networks matter to explain policy design?"

Physics winner: Merritt Moore, Ph.D. student, University of Oxford, United Kingdom

"Exploring multi-photon states for quantum information applications"

Biology winner: Pearl Lee, Ph.D. student, University of Sydney, Australia

"Cellular interactions with tropoelastin"

Chemistry winner: Jyaysi Desai, Ph.D. student, Ludwig Maximilian University of Munich, Germany.

"Molecular mechanisms involved in neutrophil extracellular trap (NET) formation"

All gifs created from Youtube videos courtesy of Dance Your Ph.D. winners.

[txchnologist]

Ancient Farmers Made Pumpkins Possible

by Marcus Woo, Inside Science

As you enjoy your pumpkin pie this Thanksgiving, be sure to give thanks to ancient North American farmers.

They domesticated pumpkins, squash and gourds 10,000 years ago, and if it weren't for them, there probably would be no butternut squash, no zucchini, no Jack-O-Lanterns and no pumpkin pie. Instead, all that might exist today would be a few tough, softball-sized, bitterly toxic fruits.

"We co-evolve with plants in such a way that they're useful for us and we fill a niche for them," said Logan Kistler, an anthropologist at the University of Warwick in the U.K. "Something inedible in the wild can be made edible and delicious in domestication."

The domestication of these fruits, which belong to the genus Cucurbita, is the focus of Kistler's new study. It paints a sweeping, 10,000-year history connecting humans, the rise of the pumpkin, and the fall of the mammoth.

"These are plants that are adapted to a landscape with large mammals," said Kistler, whose team published the research November 16 in the journal Proceedings of the National Academy of Sciences. "As large mammals disappeared, some of [the plants] adapted by partnering with humans."

Before humans began domesticating Cucurbita, the wild, bitter species were found across North America — a source of food for large mammals like mammoths, mastodons, and ground sloths. The animals munched on the gourds, spreading the seeds through droppings. But when large mammals started becoming extinct, wild Cucurbita dwindled.

The reason Cucurbita was so reliant on large mammals, the researchers hypothesized, was that only the big beasts could stomach the fruit's toxic bitterness. For smaller mammals like mice and shrews, Cucurbita was inedible. Because they didn't eat it, they couldn't disperse the seeds.

The ability to taste and consume bitter compounds seemed to be related to animal size. A mouse was so small that a couple nibbles of a toxic squash could be lethal, forcing it to evolve a heightened sensitivity to bitterness. A mammoth, on the other hand, could tolerate a much larger dose and didn't need to be as sensitive.

To test this idea, the researchers scanned the genomes of 46 modern mammals ranging from a mouse to an African elephant, looking for TAS2R, a gene that codes for bitter taste receptors. They found that indeed, the smaller the animal, the greater variety of bitter-taste receptor genes it had, and the better it was at discerning — and thus avoiding — bitterness.

The disappearance of big mammals had another harmful effect on Cucurbita, Kistler said. Cucurbita are weeds that thrive in disturbed habitats like a patchy field trampled over by mammoths. Without these ambling giants, Cucurbitalost places to grow.

The plants' future, it seemed, was bleak.

Fortunately, the fruit found a new mammal to rely on: humans. People had been using wild gourds for containers and possibly even floatation devices for fishnets. But over time, they began eating the fruit, replanting the ones that were most palatable. Eventually, over thousands of years, the fruit evolved to become mild and tasty — and now icons of the fall season.

Scientists have previously known that Cucurbita was domesticated. But to gain more insight, the researchers analyzed the genomes of ancient Cucurbita samples — bits of seeds and rind — found in caves in places such as central Mexico and the Ozark Mountains in the central U.S. The genetic patterns of the samples reveal human agricultural fingerprints all over the plant's evolutionary history.

"Domestication was a widespread phenomenon," Kistler said.

In particular, the genetic evidence suggests people living in what's now Arkansas developed their own distinct subspecies of squash. That contradicts conventional wisdom, said Gayle Fritz, an archaeologist at Washington University at St. Louis, who was not involved in the new study. Most scientists had previously assumed all squash were domesticated in Mexico or Mesoamerica.

But what sets this study apart is that it reaches so far back in time.

"I don't know of many [other] examples of plant domestication that take such a deep temporal view — in this case, even the pre-human occupation of the western hemisphere," Fritz said.

Such a historical view underscores the fact that even domesticated crops are part of a constantly changing ecosystem.

"It's worth thinking about domestic plants as a species in a symbiotic relationship with us," Kistler said. "Ecology is still changing, the climate is still changing. And as these changes occur, plants are going to respond — and they're not necessarily going to respond in ways that are exactly what we have in mind or what's most beneficial for us."

Top Image: Squash varieties courtesy of George Perry/Penn State.

[txchnologist]

Coating Makes Steel Tougher, Keeps Microbes From Sticking

More and more objects are getting superhydrophobic coatings that make liquids bounce right off. Surfaces with complex nanoscopic structures that prevent wetting will soon be deployed on wind turbine blades and aircraft wings to prevent ice from sticking, and even concrete is being doped with superhydrophobic compounds to help it last decades longer.

Much still needs to be done, though, to strengthen these coatings because any damage can remove the ability to repel liquids. Such an advance is hugely important since there are potentially life-saving healthcare applications if this hurdle could be overcome with a stable, nontoxic coating for steel. Just imagine if implants, scalpels and other tools used on patients had a surface impossible for infection-causing microbes to cling to.

Now, Joanna Aizenberg and her colleagues at Harvard’s Wyss Institute for Biologically Inspired Engineering have demonstrated a possible solution. They’ve been able to coat stainless steel with nanoporous tungsten oxide, which repels all liquids. What’s more, the surface is extremely tough, maintaining superhydrophobicity even after being scratched with sharp steel objects and diamond.

“So far, these two concepts - mechanical durability and anti-fouling - were at odds with each other,” Aizenberg said in a statement. “This research shows that careful surface engineering allows the design of a material capable of performing multiple, even conflicting, functions, without performance degradation. Our slippery steel is orders of magnitude more durable than any anti-fouling material that has been developed before."

Her team was able to deposit the tungsten oxide directly onto the steel using a standard electrochemical deposition process. It formed separate islands on the steel’s surface. These islands mean that neighboring islands can be physically damaged without hindering the overall repellency of the coating. The researchers also unexpectedly found that the material actually strengthened the steel it was deposited on. 

They found the treated surgical tools and pieces of naval construction steel were able to completely repel liquids even after battering them with sand, ultraviolet light and extreme temperatures. Their results were published recently in the journal Nature Communications.

“Because we show that this material successfully repels bacteria and blood, small medical implants, tools and surgical instruments like scalpels and needles that require both significant mechanical strength and anti-fouling property are high value-added products we are exploring for application and commercialization,” said study coauthor Philseok Kim.

All gifs created from videos courtesy of Tesler et al./Nature Communications.

[txchnologist]

Pine Cones Inspire Walking Robot

When it comes to robots taking tips from nature to move, there is no shortage of examples from the animal kingdom. Engineers have used dogs, horses, insects and many other animals as inspiration to help their creations walk, fly, swim and crawl. 

Now we’re seeing people look even further afield for ideas to get robots to get up and go. Not too long ago, we brought you machines that move because of the swelling and contracting of bacterial spores. Yesterday, researchers from South Korea’s Seoul National University demonstrated another technique that they took from a different kingdom, one that isn’t usually associated with mobility.

Engineer Ho-Young Kim and colleagues looked to the plant world to make a simple legged robot that can walk in a single direction with no power needed besides changing ambient humidity. Their muse? The unassuming pine cone.

Pine cones are the seed-bearing organs of coniferous plants. The cones of many trees include dozens of scales, which can open and close with changing humidity. There are several ideas on why this movement occurs--to aid in pollination or seed dispersal, among other explanations--but the exact function remains a point of debate. Either way, the movement is slow and hasn't been on the radar of roboticists looking to make-fleet-footed machines.

"Plants move slowly -- one cycle of bending and unbending can take an entire day,” Kim said in a release produced in advance of a presentation on their work at the the American Physical Society's 68th Annual Meeting of the Division of Fluid Dynamics. Kim’s team also produced water-strider-inspired robots that can jump from the surface of water earlier this year. 

At the heart of their current work is a material with two layers coating it, one made out of nanoscale fibers that swells when humidity increases and another that remains unchanged. This effect is an actuator--a machine muscle--that repeatedly bends and unbends with changing humidity. by attaching little legs to this actuator, they were able to get the robot to move in a direction of their choosing. 

They believe their humidity-powered bots could one day find use in medical applications. One area where they think it could be used is in treating skin, which is naturally more humid than surrounding air. "The concept is that by bending, some part of the robot will move away from the skin to encounter dry atmospheric air,” he said. “When it dries, the robot will return to an upright position near the skin. Such a robot could do jobs like disinfecting wounds, removing skin wrinkles, and nourishing skin tissues.”

Top gif: created from video courtesy of Ho-Young Kim.