Researchers find “lost” memories

Fri, 05/29/2015 - 7:27am Helen Knight, MIT News correspondent Image: Christine Daniloff/MIT Memories that have been “lost” as a result of amnesia can be recalled by activating brain cells with light. In a paper published in Science, researchers at Massachusetts Institute of Technology (MIT) reveal that they were able to reactivate memories that could not otherwise be retrieved, using a technology known as optogenetics. The finding answers a fiercely debated question in neuroscience as to the nature of amnesia, according to Susumu Tonegawa, the Picower Professor in MIT’s Dept. of Biology and director of the RIKEN-MIT Center at the Picower Institute for Learning and Memory, who directed the research by lead authors Tomas Ryan, Dheeraj Roy and Michelle Pignatelli. Neuroscience researchers have for many years debated whether retrograde amnesia—which follows traumatic injury, stress, or diseases such as Alzheimer’s—is caused by damage to specific brain cells, meaning a memory cannot be stored, or if access to that memory is somehow blocked, preventing its recall. “The majority of researchers have favored the storage theory, but we have shown in this paper that this majority theory is probably wrong,” Tonegawa says. “Amnesia is a problem of retrieval impairment.” Memory researchers have previously speculated that somewhere in the brain network is a population of neurons that are activated during the process of acquiring a memory, causing enduring physical or chemical changes. If these groups of neurons are subsequently reactivated by a trigger such as a particular sight or smell, for example, the entire memory is recalled. These neurons are known as “memory engram cells.” Shedding light In 2012 Tonegawa’s group used optogenetics—in which proteins are added to neurons to allow them to be activated with light—to demonstrate for the first time that such a population of neurons does indeed exist in an area of the brain called the hippocampus. However, until now no one has been able to show that these groups of neurons do undergo enduring chemical changes, in a process known as memory consolidation. One such change, known as “long-term potentiation” (LTP), involves the strengthening of synapses, the structures that allow groups of neurons to send signals to each other, as a result of learning and experience. To find out if these chemical changes do indeed take place, the researchers first identified a group of engram cells in the hippocampus that, when activated using optogenetic tools, were able to express a memory. When they then recorded the activity of this particular group of cells, they found that the synapses connecting them had been strengthened. “We were able to demonstrate for the first time that these specific cells—a small group of cells in the hippocampus—had undergone this augmentation of synaptic strength,” Tonegawa says. The researchers then attempted to discover what happens to memories without this consolidation process. By administering a compound called anisomycin, which blocks protein synthesis within neurons, immediately after mice had formed a new memory, the researchers were able to prevent the synapses from strengthening. When they returned one day later and attempted to reactivate the memory using an emotional trigger, they could find no trace of it. “So even though the engram cells are there, without protein synthesis those cell synapses are not strengthened, and the memory is lost,” Tonegawa says. But startlingly, when the researchers then reactivated the protein synthesis-blocked engram cells using optogenetic tools, they found that the mice exhibited all the signs of recalling the memory in full. “If you test memory recall with natural recall triggers in an anisomycin-treated animal, it will be amnesiac, you cannot induce memory recall,” Tonegawa says. “But if you go directly to the putative engram-bearing cells and activate them with light, you can restore the memory, despite the fact that there has been no LTP.” “Groundbreaking paper”  Further studies carried out by Tonegawa’s group demonstrated that memories are stored not in synapses strengthened by protein synthesis in individual engram cells, but in a circuit, or “pathway” of multiple groups of engram cells and the connections between them. “We are proposing a new concept, in which there is an engram cell ensemble pathway, or circuit, for each memory,” he says. “This circuit encompasses multiple brain areas and the engram cell ensembles in these areas are connected specifically for a particular memory.” The research dissociates the mechanisms used in memory storage from those of memory retrieval, according to Ryan. “The strengthening of engram synapses is crucial for the brain’s ability to access or retrieve those specific memories, while the connectivity pathways between engram cells allows the encoding and storage of the memory information itself,” he says. Changes in synaptic strength and in spine properties have long been associated with learning and memory, according to Alcino Silva, director of the Integrative Center for Learning and Memory at the Univ. of California at Los Angeles. “This groundbreaking paper suggests that these changes may not be as critical for memory as once thought, since under certain conditions, it seems to be possible to disrupt these changes and still preserve memory,” he says. “Instead, it appears that these changes may be needed for memory retrieval, a mysterious process that has so far evaded neuroscientists.” Source: Massachusetts Institute of Technology

Facts about France

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5 Things That Absolutely Kill Your Productivity

Martin Barraud / OJO Images / Getty Images Freelancers are in an interesting position. You are in charge of your time, and making the most of it is absolutely crucial to a successful freelancing career. Unlike office jobs with dedicated work hours, freelance work requires a great deal self-motivation and personal accountability. That being said, here are some of the most time-wasting, productivity-killing pitfalls to avoid when freelancing: Distracting Websites   We all know that feeling, “I’m just going to open up Facebook for a quick second before I get to work.” Before you know it, an hour’s gone by and you’ve not gotten shit done. While taking a break to browse around the web for pleasure can be a helpful reprieve, the point is that it’s a break. The most successful freelancers know that their time is valuable, and setting aside blocks of time for dedicated work is absolutely crucial. Thankfully, even those lacking the most basic sense of self-control can force themselves to get things done with the right tools. There are a myriad of websites and apps like StayFocused or Cold Turkey are out there that block certain websites or even web browsing all together and allow you to set parameters to keep you on task. You don’t have to go nuclear here and toss out your router. Just set aside dedicated blocks of time for work and periodic breaks to keep yourself sane. Procrastination   A concept familiar to everyone. From putting off your third grade math homework to waiting till the last minute to get started on that proposal, the procrastination bug is infectious and everyone can catch it. Some people tend to use the excuse, “But I work best under pressure!” This may be true for some, but more often than not you’re sacrificing the quality of the work. Give yourself enough time to complete a project well, and you minimize your chances of making a critical mistake or missing a deadline. Clutter   If your desk is looking more like a warzone than a productive workspace, you’re likely suffering from some serious clutter issues. Piles of books, folders, and a jillion other work items can add up quickly, so it’s best to keep on top of things before they detract from the effectiveness of your workspace. Now, I’m not saying you need a blank canvas every time you sit down to get things done, but there’s nothing that kills a productive streak quicker than rifling through every stack of crap on your desk to find the right document. Don’t go all hyper-anal here — Drill Sergeant Hartman isn’t going to be wiping his finger across your desk looking for dust particles. Just keep a bit of a system in place; keep important things nearby, and clear away all the crap that’s distracting you from the task at hand. Unfinished Work   This one really goes hand in hand with procrastination. Even a quick to-do list can explode into an all-nighter if you let your unfinished work get out of hand. There’s nothing wrong with walking away from something to switch gears and picking it back up later with a fresh set of eyes, but make sure you’re actually coming back to the task. One way to keep yourself in check on this front is to prioritize. Make a to-do list with some hierarchy: things that absolutely must be completed today sit at the very top, while projects that have some flexibility are lower priorities. This way, even when you’re switching between one project and another, you’ll always know which tasks require the most of your attention on that particular day. Living in the Stone Age   You might have a particular way of going about things that simply works best for you; we all get a little set in our ways from time to time. But ignoring a technology or a service that could streamline your processes can really come back to bite you in the end. You don’t see brokers waiting for the daily newspaper to keep on top of the stock market, right? Keep informed about new technologies that pertain to your business, and don’t be afraid to try something out of your comfort zone if you think it can help your business. As a freelancer, you’re in one of the most independent fields of work out there. All of this freedom comes with a higher degree of responsibility, however, and knowing what to look out for helps you avoid them all the better.  www.about.com

Top 10 Highly-Desired Skills You Can Teach Yourself

On countless occasions, you've likely said to yourself "I wish I knew how to do ______." Then, of course, life got in the way and you put it off until you could find the time. Maybe you wanted to become fluent in a language, learn a new instrument, start performing your house repairs, or a master a myriad of other skills. With the vast amount of knowledge online, you're now your only excuse. Here are the top ten most highly desired skills that you can teach yourself—and should. 10. Repair Just About Anything Sure, you don't need to repair anything anymore. You can just pay someone else to do it. But where's the ingenuity in that? Plus, who wants to waste a bunch of money on simple tasks you can handle on your own? If you've adopted the DIY spirit, learning to repair your own stuff is one of the easiest and more rewarding skills you can acquire. It's especially fruitful because as you learn new things, you can put them to use right away. So how do you teach yourself? We've outlined tons of repairs you can learn on your own to get you started, but if you're looking for something specific there is no shortage of how-to videos available on YouTube and VideoJug. There will be occasions when you do need to call a professional, as you're not going to be a master repairman (or woman) instantly, but do remember that there is an opportunity when things break: you can learn how to fix them. 9. Pick Up an Artistic Skill Like Illustration, Painting, or Photography Although it often won't earn you the big bucks, artistic skills are highly desired because they provide you with the technical abilities required to create something beautiful. You're going to have to find your own inspiration and subject matter, but the skill you'll need is really just a matter of technical aptitude and practice. Picking up a book of anatomy and drawing different bones and muscles will teach you how to draw people. Drawing grids over photographs can show you basic perspective. Obviously it isn't as simple as that, but focusing on learning to draw one simple thing, like the petals of a flower or the human hand, will help you learn how it works and get in a reasonable amount of practice. When you're ready to move on from the basics and start illustrating on your computer, check out our digital painting lessons. For those of you interested in photography, we have lessons for you, too. Whatever you're looking to learn, just set aside 15-30 minutes every day to practice a very small part of that skill. It'll take awhile to teach yourself how to draw, paint, take better photos, make hamburger sculptures out of clay, or whatever it is you want to do, but breaking the daunting task into pieces and practicing each part slowly will do the trick. Plus, it's a really nice way to unwind at the end of the day. 8. Learn to Defend Yourself Who likes getting their ass kicked? Probably a very small majority. If that's what you're into, it doesn't require much  skill—just endurance. If you'd prefer to not end up hurt or injured as the result of an unexpected attack, perhaps it's time to pick up some self-defense skills. While you'll probably want to have a partner around to help you out—at least when you want to test your skill—we've outlined several self-defense moves that you can learn on your own. Although you will hopefully never need to actually employ the techniques you acquire, if you do you'll increase your chances of coming out of a fight unharmed. Plus, it's pretty cool to walk around with the confidence of being able to take on most anyone in a fight. 7. Improve Your Design Skills (or At Least Acquire a Sense of Style) Design and style aren't an exact science, as tastes differ and change as time goes on, but there are a few principles you can pick up that'll make your work, home, or whatever needs an aesthetic boost looking better than average. If we're talking traditional design, you'll first want to learn the basics of type and layout. These are skills you can employ in your everyday work to make it look a lot more attractive. This may seem like a nearly-useless skill, because spreadsheets aren't getting entered in any beauty contests, but when something looks good it can have a greater impact. That's always a plus in your work. If you want to take things a bit further, you can bump those skills up a notch and apply them to web site design in Photoshop. Your sense of style is even a useful thing when choosing a great wallpaper and creating a clean and organized desktop on your computer. If your home is boring, just follow these guidelines for awesome interior design. You don't have to be a pro, but learning the basics of design can make your life a lot brighter. 6. Pick Up Just About Any Subject You Missed In College Whether it's science, finance, math, humanities, law, or anything else, if there's a course you wish you took in college you're not out of luck—you can probably find it online. To help you out, we've rounded up every great source of online education so you can gain that knowledge you missed. What's great about learning online is that you can take it at your own pace and put in as much time as you can spare each day. You don't necessarily have to master a subject, either, but learn as much as you need or want to know. While you won't end up with a degree for your hard work, you will be a little bit smarter—and that's the most important part. 5. Build and Hack Electronic Hardware We love technology, and we love it more when we can make it do pretty much whatever we want. There is almost no end to what you can hack, but getting started does require teaching yourself a few skills. Learning to build a computer is a good place to start. Soldering is especially helpful, and understanding the basics of arduino can help you build some really neat stuff. One of the best ways to get started is to pick a project and learn by doing. If you're not sure where to start, our DIY tag page can offer a few ideas. 4. Play a (New) Instrument Whether you already know how to play an instrument and want to learn something new or are musically inept, you'll find plenty of resources online to help you teach yourself to play just about anything. If guitar is your thing, you're in luck as you'd be hard-pressed to not find online lessons. JustinGuitar.com offers over 500, and we've rounded up plenty more. The internet can also teach you piano, drums, and even orchestral instruments like the flute and violin. Just like with repair skills, you can find a lot of how-to videos on both YouTube and VideoJug. In addition to the instrument, you're also going to want to learn a little music theory. Ricci Adams' musictheory.net offers a bunch of free lessons to get you started. When you're starting to get good, you can put together a home recording studio on the cheap to start capturing your talent and sharing it with others. 3. Cook Like a Pro With so many recipe sites and cooking skill how-to videos online, it's a surprise that everyone isn't a master chef at this point. There are so many simple things you can learn that can vastly improve your culinary skill set really quickly, many of which we've covered. We've written so much on the subject of learning to cook better that this little paragraph isn't enough to cover it all, but there are a few posts in particular that you'll want to read to get started. First, these tips and tricks for budding foodies will make your learning process easier. Second, follow this station-by-station kitchen guide to stay organized and efficient when cooking. Finally, these must-know recipes will help you round out your arsenal of cooking knowledge. For more, we like recipe and how-to sites Epicurious and How2Heroes. And, of course, you can always check our how to and kitchen tag pages for more great tips. 2. Become Fluent in a New Language When we asked you which skills you really wanted to learn, language was at, or close to the top of many peoples' lists. Fortunately for you, this clever technique offers a way to all but master a new language in a short period of time by teaching yourself. You'll still have to work hard and put in the minutes every day, but you can come out speaking fluently in about half of a year. Pretty cool. 1. Make a Web Site, Create an App, or Just Learn to Code Learning to code is something most of us Lifehackers aspire to do at one point or another, as it's not only a great way to create cool apps and tools that we want to use but it's also an incredibly marketable skill when trying to get a job. To get you started, we've put together two helpful sets of lessons: the basics of programming and making a web site. Both sets include further resources, but there are plenty of others that we've learned about or have cropped up since. For starters, commenter mistermocha suggests using the "learn ___ the hard way" series. For example, if you wanted to learn Python, you could visit learnpythonthehardway.org. If you just fill in the blank with the language you want to learn and put that into a web search, you'll likely find what you're looking for. (You can also find most of the series here.) If you prefer more interactive lessons, you'll want to check out one of our favorites: Codecademy. I learned by subscribing to online learning site Lynda.com (and through a few basic classes back in college), which is still excellent, but I'd probably have gone with Code Academy at this point since it's in the free category. Regardless of how you decide to learn, programming skills are becoming more and more useful as time goes on. Code is not as complicated as you think, so go get started!  Photos by Mister Wilson, Alex Indigo, Andy Mangold source : lifehacker.com

Researchers prove magnetism can control heat, sound

Fri, 05/29/2015 - 7:47am Jamie Abel, Ohio Supercomputer Center A team led by Ohio State's Wolfgang Windl, PhD, used OSC's Oakley Cluster to calculate acoustic phonon movement within an indium-antimonide semiconductor under a magnetic field. Their findings show that phonon amplitude-dependent magnetic moments are induced on the atoms, which change how they vibrate and transport heat. Image: OSUPhonons—the elemental particles that transmit both heat and sound—have magnetic properties, according to a landmark study supported by Ohio Supercomputer Center (OSC) services and recently published by a researcher group from The Ohio State Univ. In Nature Materials, the researchers describe how a magnetic field, roughly the size of a medical MRI, reduced the amount of heat flowing through a semiconductor by 12%. Simulations performed at OSC then identified the reason for it—the magnetic field induces a diamagnetic response in vibrating atoms known as phonons, which changes how they transport heat. "This adds a new dimension to our understanding of acoustic waves," said Joseph Heremans, PhD, Ohio Eminent Scholar in Nanotechnology and a professor of mechanical engineering at Ohio State whose group performed the experiments. "We've shown that we can steer heat magnetically. With a strong enough magnetic field, we should be able to steer sound waves, too." People might be surprised enough to learn that heat and sound have anything to do with each other, much less that either can be controlled by magnets, Heremans acknowledged. But both are expressions of the same form of energy, quantum mechanically speaking. So any force that controls one should control the other. The nature of the effect of the magnetic field initially was not understood and subsequently was investigated through computer simulations performed on OSC's Oakley Cluster by Oscar Restrepo, PhD, a research associate, Nikolas Antolin, a doctoral student, and Wolfgang Windl, PhD, a professor, all of Ohio State's Dept. of Materials Science and Engineering. After painstakingly examining all possible magnetic responses that a non-magnetic material can have to an external field, they found that the effect is due to a diamagnetic response, which exists in all materials. This suggests then that the general effect should be present in any solid. The implication: in materials such as glass, stone, plastic—materials which are not conventionally magnetic—heat can be controlled magnetically, if you have a powerful enough magnet. This development may have future impacts on new energy production processes. But, there won't be any practical applications of this discovery any time soon: seven-tesla magnets like the one used in the study don't exist outside of hospitals and laboratories, and a semiconductor made of indium antimonide had to be chilled to -450 F (-268 C)—very close to absolute zero—to make the atoms in the material slow down enough for the phonons' movements to be detectible. To simulate the experiment, Windl and his computation team employed a quantum mechanical modeling strategy known as density functional theory (DFT). The DFT strategy was used to determine how the electron distribution changed when atoms vibrated with or without magnetic field. The motion of the electrons around their atoms changed in the field, creating diamagnetic moments when phonons were present. These moments then reacted to the field and slowed the heat transport, similar to an eddy current brake in a train. The simulations were conducted on the Oakley Cluster, an HP/Intel Xeon system with more than 8,300 processor cores to provide researchers with a peak performance of 154 Teraflops--tech-speak for 154 trillion calculations per second. Since atoms can vibrate in many different ways, a large number of simulations were necessary, consuming approximately 1.5 million CPU hours even on a machine as powerful as Oakley. OSC engineers also helped the research team use OSC's high-throughput, parallel file system to handle the immense datasets generated by the DFT model. "OSC offered us phenomenal support; they supported our compilation and parallel threading issues, helped us troubleshoot hardware issues when they arose due to code demands, and moved us to the Lustre high-performance file system after we jammed their regular file system," said Antolin, who is the expert for high-demand computations in Windl's group. "Dr. Windl and his team are important OSC clients, and we're always pleased to support their research projects with our hardware, software and staff support services," said David Hudak, PhD, OSC's director of supercomputer services. "With the addition of the Ruby Cluster this past fall and another, much more powerful system upcoming this fall, OSC will continue to offer even larger, faster and more powerful services to support this type of discovery and innovation." . Source: Ohio Supercomputer Center

Oral Medication & Non-Insulin Injectables

Knowing the type of medication you take, when to take it and what it does is really important to managing your diabetes. Arming yourself with this information can help you to manage your blood sugars and alert you to potential side effects.Because everyone with diabetes is so different, your prescription will take your individual differences into consideration. This includes your blood sugars, past medical history, age, cost, potential side effects, and the medication's effects on weight.
Before filling any prescription, you may want to confirm with your insurance provider or health care provider if this medicine is preferred by your plan – this will help to save you money. Remember, while medications are very important, they are always considered secondary to diet and exercise. If you are new to diabetes medicines and are not sure what your medicine does or when you should take it, find out now.

Table of Contents

1. Biguanides

• Metformin (Fortmate®, Glucophage®, Glucophage XR®, Glumetza®, Riomet®)

2. Thiazolidinediones (TZD’s)

• Pioglitazone (Actos®)

3. Sulfonylureas

• Glimepiride (Amaryl®)
• Glyburide (Diabeta®, Micronase®)
• Glipizide (Glucotrol®, GlucotrolXL®)

4. Meglitinides

• Repaglinide (Prandin®)
• Nateglinide (Starlix®)

5. DPP-4 Inhibitors

• Sitagliptin (Januvia®)
• Linagliptin (Trajenta®)
• Saxagliptin (Onglyza®)
• Alogliptin (Nesina®)

6. SLGT-2 Inhibitors

• Canagliflozin (Invokana®)
• Dapagliflozin (Farxiga®)
• Empagliflozin (Jardiance®)

7. Alpha Glucosidase Inhibitors

• Miglitol (Glyset®)
• Acarbose (Precose®)

8. Combination Oral Medicines
9. Injectable Non-Insulin Medicines
Learn About More Oral Diabetes Medications

source to this post - www.about.com

Spiraling laser pulses could change graphene

Thu, 05/28/2015 - 11:46am

SLAC National Accelerator Laboratory

This illustration depicts the structure of graphene, which consists of a single layer of carbon atoms arranged in a honeycomb pattern. A new simulation suggests that spiraling pulses of polarized laser light could change graphene's nature, turning it from a metal to an insulator. Led by researchers at SLAC and Stanford, the study paves the way for experiments that create and control new states of matter with this specialized form of light. Image: AlexanderAlUS via Wikimedia Commons

A new study predicts that researchers could use spiraling pulses of laser light to change the nature of graphene, turning it from a metal into an insulator and giving it other peculiar properties that might be used to encode information.

The results, published in Nature Communications, pave the way for experiments that create and control new states of matter with this specialized form of light, with potential applications in computing and other areas.

“It’s as if we’re taking a piece of clay and turning it into gold, and when the laser pulse goes away the gold goes back to clay,” said Thomas Devereaux, a professor at the U.S. Dept. of Energy (DOE)’s SLAC National Accelerator Laboratory and director of the Stanford Institute for Materials and Energy Sciences (SIMES), a joint SLAC/Stanford institute.

“But in this case,“ he said, “our simulations show that we could theoretically change the electronic properties of the graphene, flipping it back and forth from a metallic state, where electrons flow freely, to an insulating state. In digital terms this is like flipping between zero and one, on and off, yes and no; it can be used to encode information in a computer memory, for instance. What makes this cool and interesting is that you could make electronic switches with light instead of electrons.”

Devereaux led the study with Michael Sentef, who began the work as a postdoctoral researcher at SLAC and is now at the Max Planck Institute for the Structure and Dynamics of Matter in Germany.

Tweaking a wonder material

Graphene is a pure form of carbon just one atom thick, with its atoms arranged in a honeycomb pattern. Celebrated as a wonder material since its discovery 12 years ago, it’s flexible, nearly transparent, a superb conductor of heat and electricity and one of the strongest materials known. But despite many attempts, scientists have not found a way to turn it into a semiconductor—the material at the heart of microelectronics.

An earlier study demonstrated that it might be possible to take a step in that direction by hitting a material with circularly polarized light—light that spirals either clockwise or counterclockwise as it travels, a quality that can also be described as right- or left-handedness. This would create a “band gap,” a range of energies that electrons cannot occupy, which is one of the hallmarks of a semiconductor.

In the SIMES study, theorists used the DOE’s National Energy Research Scientific Computing Center at Lawrence Berkeley National Laboratory to perform large-scale simulations of an experiment in which graphene is hit with circularly polarized pulses a few millionths of a billionth of a second long.

Getting as close to real as possible

“Previous studies were based on analytical calculations and on idealized situations,” said Martin Claassen, a Stanford graduate student in Devereaux’s group who made key contributions to the study. “This one tried to simulate what happens in as close to real experimental conditions as you can get, right down to the shape of the laser pulses. Doing such a simulation can tell you what types of experiments are feasible and identify regions where you might find the most interesting changes in those experiments.”

The simulations show that the handedness of the laser light would interact with a slight handedness in the graphene, which is not entirely uniform. This interaction leads to interesting and unexpected properties, said SLAC staff scientist and study co-author Brian Moritz. Not only does it produce a band gap, but it also induces a quantum state in which the graphene has a so-called “Chern number” of either one or zero, which results from a phenomenon known as Berry curvature and offers another on/off state that scientists might be able to exploit.

Insights go beyond graphene

While this study does not immediately open ways to make electronic devices, it does give researchers fundamental insights that advance the science in that direction. The results are also relevant to materials called dichalcogenides, which are also two-dimensional sheets of atoms arranged in a honeycomb structure.

Dichalcogenides are the focus of intense research at SIMES and around the world because of their potential for creating “valleytronic” devices. In valleytronics, electrons move through a two-dimensional semiconductor as a wave with two energy valleys whose characteristics can be used to encode information. Possible applications include light detectors, low-energy computer logic and data storage chips and quantum computing. In addition to the work on graphene, members of the research team have also been simulating experiments involving the interaction of light with dichalcogenides.

“Ultimately,” Moritz said, “we’re trying to understand how interaction with light can alter a material’s character and properties to create something that’s both new and interesting from a technological point of view.”

Source: SLAC National Accelerator Laboratory

Recycling nuclear waste

Fri, 05/29/2015 - 11:12am

Kate McAlpine, Univ. of Michigan

The simulation of the reactor core confirms that the dead zones allow the reactor to operate safely. This image shows where atoms split, or fission. The fuel rods run vertically, with the red, high-fission fuel regions and blue, low-fission dead zones. Image: Seker et al, Univ. of Michigan

The simulation of the reactor core confirms that the dead zones allow the reactor to operate safely. This image shows where atoms split, or fission. The fuel rods run vertically, with the red, high-fission fuel regions and blue, low-fission dead zones. Image: Seker et al, Univ. of Michigan

An advanced nuclear reactor under development by Hitachi could help solve the nuclear waste problem, and Univ. of Michigan researchers were involved in verifying its safe performance through computer simulations.

The U-M team worked with colleagues at the Massachusetts Institute of Technology and the Univ. of California, Berkeley. After more safety analysis, Hitachi plans to move forward with a prototype of the "resource-renewable boiling water reactor" in the next few years.

One of the major technological hurdles for nuclear energy is developing systems to dispose of the waste produced by typical reactors. It must be sealed away for hundreds of millennia while the radioactivity naturally decreases.

Hitachi's new design would burn off the longest-lived radioactive materials, called transuranics, shortening that isolation period to a few centuries. This would recycle the nuclear waste to produce yet more energy and reduce the amount that must be stowed away.

"Because of transuranics, we're talking about lifetimes for storing fuel that we can't even fathom," said Thomas Downar, U-M professor of nuclear engineering and radiological sciences. "You get this down to a hundred years, then you're talking about the ability to engineer a container that you have confidence will last that long."

In the conventional boiling water reactors that currently produce about 30 percent of all the nuclear-generated electricity in the U.S., the neutrons that split uranium atoms have been slowed by the boiling water. In contrast, the Hitachi design uses fast neutrons since they are more likely to split, or fission, transuranic atoms.

Prototype fast reactors have been running since the 1970s, but they use a sodium coolant. Sodium burns when it comes into contact with air and reacts violently with water. This is one of the reasons why U.S. utilities that operate reactors have been hesitant to consider sodium-cooled designs.

A water-cooled fast reactor, though, could offer safer and more familiar operation. The challenge was designing a water-cooled core that would stop itself if it started overheating and the water turned to steam. In conventional reactors, the water's slowing action acts as a failsafe because steam is less effective at decelerating neutrons. Since fewer neutrons are at the right speed to cause fissions, the reaction rate slows down too.

For a boiling water reactor that's burning transuranics, this scenario is trickier. The faster neutrons could mean a faster fission rate, creating more heat, steam and fast neutrons.

"If something goes wrong and the power increases, you want to have the fission rate decrease," Downar said.

To create this safety feature in their reactor, Hitachi engineers plan large dead zones in the fuel rods, made of materials with a much lower probability of fissioning with fast neutrons.

Hitachi calculated that as the presence of steam reduced the density of the water, fast neutrons were likely to travel further. By keeping the active regions of the fuel assembly small, more neutrons would be lost to these "blanket" regions in an overheating scenario, slowing the fission rate.

Before beginning the expensive process of prototyping, Hitachi wanted to confirm with outside experts that the design would perform as expected.

With funding from the Department of Energy, members of Downar's group spent the last three years developing codes that could simulate the more complex layout and physics of Hitachi's reactor core design. For example, uranium fission reactions are reasonably steady and easy to predict, but transuranic reactions are irregular and difficult to calculate accurately.

The U-M team developed a method to generate data that simulates the way transuranics burn. They then applied this data to established codes currently used for boiling water reactor analysis. By looking at what happened when the steam bubbles appeared, the team found that the fast neutrons tended to leave the reactive part of the fuel assembly, slowing the reaction rate as planned.

Now, the university teams are about to begin a careful comparison of their methods with the predictions from the Hitachi computer codes to discover any differences in the simulation of the advanced reactor's performance. Hitachi will fund the teams at U-M, MIT and Berkeley for the next phases of the project.

Source: Universty of Michigan

‘$5 Insanity’: What You Should Know About Flakka

                                         May 21, 2015 -- Some call it “$5 Insanity.”

Flakka, a new designer drug, is surging in popularity. Poison control centers in states including Florida, Alabama, Mississippi, and Texas are responding to an increasing number of incidents involving it.

Here’s what you need to know:

What is flakka?

It’s a man-made stimulant called an alphaPVP. It’s similar to “bath salts,” another dangerous drug that’s grabbed headlines in recent years.

Its off-white, coarse crystals sell for as little as $5 a hit. The name comes from la flaca, a Spanish club-slang term for a sexy, skinny girl.

“It looks like aquarium gravel,” says Alfred Aleguas, PharmD, managing director of the Florida Poison Information Center, Tampa.

How is it used?

People have tried taking it in a number of ways, says Jeffrey Bernstein, MD, medical director of the Florida Poison Information Center, Miami.

Those ways include:

    Snorting
    Mixing with food
    Drinking like a tea
    Pressing into pill form
    Inserting it into the rectum
    Vaping in an e-cigarette
    Injecting

“With injecting, you’re really asking for trouble, because the drug is likely to be cut with … dirt, with talc, who knows what else -- and you’re putting all that in your veins,” Bernstein says.

How does it work on the brain?

Users feel a sense of euphoria, Bernstein says. “It plays with your neurotransmitters, [brain chemicals] like dopamine and serotonin.”

That can lead to a state called excited or agitated delirium in a high that lasts for several hours.

What are the risks?

People who are high on flakka often lose touch with reality, Aleguas says.

“They don’t know what they’re doing, they’re hallucinating, they’re paranoid, they’re aggressive, they’re super-agitated,” he says. “That’s why you see news stories of people running down the street naked, banging on cars in traffic and just crazy, crazy stuff.”

Other health effects that Aleguas and Bernstein often see include:

Another dangerous effect is hyperthermia, or elevated body temperature, which Bernstein says can reach 108 degrees. At that temperature, he says, blood can no longer clot and a person starts to bleed internally.
..

“They bleed and they go into multi-organ failure,” he says. “Lung, liver, kidney, and brain injury can each occur when their temperature stays too high for too long.”

In an emergency room, doctors attempt to cool the person, to calm them. They may also use diazepam, midazolam, or another similar drug to slow a user’s heartbeat.

“We give them symptomatic and supportive care, try to keep them from hurting themselves and hospital staff,” he says.

Who's using flakka?

Bernstein says most users are male and in their teens, 20s, or 30s, although some are older.

“I haven’t seen any regular users,” he says. “It tends to be used sporadically and is associated with concerts and parties and things like that.”

And those users don’t always know what they’re getting, says Bernstein, who gets a call about flakka every day, and more on the weekends. About one-third of calls are from users looking for help, he says, while the others are from emergency personnel caring for users and looking for guidance.

“There’s no quality control on the street, so no one knows for sure what they’re taking,” he says. “Just because they bought something called flakka, no one knows if that’s really what they used, much less what kind of concentration you’re getting. It’s an unknown drug at an unknown dose, and any dose is abuse.”
“They bleed and they go into multi-organ failure,” he says. “Lung, liver, kidney, and brain injury can each occur when their temperature stays too high for too long.”

In an emergency room, doctors attempt to cool the person, to calm them. They may also use diazepam, midazolam, or another similar drug to slow a user’s heartbeat.

“We give them symptomatic and supportive care, try to keep them from hurting themselves and hospital staff,” he says.

Who's using flakka?

Bernstein says most users are male and in their teens, 20s, or 30s, although some are older.

“I haven’t seen any regular users,” he says. “It tends to be used sporadically and is associated with concerts and parties and things like that.”

And those users don’t always know what they’re getting, says Bernstein, who gets a call about flakka every day, and more on the weekends. About one-third of calls are from users looking for help, he says, while the others are from emergency personnel caring for users and looking for guidance.

“There’s no quality control on the street, so no one knows for sure what they’re taking,” he says. “Just because they bought something called flakka, no one knows if that’s really what they used, much less what kind of concentration you’re getting. It’s an unknown drug at an unknown dose, and any dose is abuse.”

                                       source to this post : www.webmd.com

TE Connectivity 3D-prints first functioning motorcycle

The 3D-printed motorcycle, on display

The 3D-printed motorcycle, on display (Credit: TE Connectivity)

Image Gallery (7 images)

Unveiled at Rapid 2015 in Long Beach, California, TE Connectivity’s exercise in 3D printing demonstrates the ability to design a motorcycle on a computer, print it in plastic, add tires and a motor, then take it for a spin. In fact it may take a little more than that to actually end up with a complete functioning motorcycle; nonetheless, the concept is nothing short of exciting.

Considering that fundamental parts such as the frame and wheel bearings are entirely printed in plastic, one would agree that TE’s goal to portray a technology that manufactures load-bearing production parts has been achieved.

Modeled in a Harley-Davidson Softail fashion, the motorcycle measures around 8 ft (2.4 m) long, weighs 250 lb (113.4 kg) and consists of more components than its designers can account for. Its frame, printed after a process of trial and error, can support a total of 400 lb (181 kg) – that would be two adult passengers. Apart from the small electric motor and tires, some other outsourced parts include the braking system, electrical wiring, battery, belt drive, mirrors, sidestand and some bolts.

The highlight is, of course, its fully functioning status. A small 1 hp (750W) electric motor can power a 15 mph (24 km/h) ride for several minutes. Though this may not sound ground-breaking, it doesn’t necessarily need a bigger battery or a stronger engine to make a point as a showbike at a conference on printing, scanning and additive manufacturing. All that matters is that, after some 1,000 work hours and US$25,000, TE Connectivity has come up with a proper motorcycle indeed.

The main load-bearing parts were constructed with Fused Deposition Modeling (FDM) technology, the process of injecting layer upon layer of ABS (acrylonitrile butadiene styrene) plastic enriched with the heat resistant resin Ultem 9085. With this process, TE printed several parts with complex dynamic properties, such as the frame.

The wheel bearings sound tricky to fabricate, especially the rear one that was printed into a single piece with the hub and the drive sprocket. After some testing miles, both bearings reportedly held up against the load they must bear and the heat generated in the process. Equally difficult work has probably been involved in the fabrication of the wheel rims, which have to support real motorcycle tires with fully-inflated tubes.

Some metal parts like the headlight housing were printed in bronze through Direct Metal Laser Sintering (DMLS), where a laser melts the desired shape out of several layers of metal powder.

Apparently this is the second prototype or, more precisely, a rebuild of the first after it suffered some damage during transportation. Thankfully creative minds saw this as an opportunity rather than a calamity, finding the chance to make some improvements on the original design.

Although it seems highly improbable for an electronic connector and sensor manufacturer to build any more motorcycles, TE Connectivity’s achievement highlights some promising prospects. Already several DMLS applications are available to the automotive and aerospace industries though companies like EOS. Stratasys, whose printers worked overtime for this project in TE’s labs, is currently in a partnership with Ducati advising the Italians on developing in-house FDM prototyping. By printing functional prototype engines, Ducati has been able to cut the development time of a new Desmosedici race engine for MotoGP from 28 to only eight months. Benefits from this process are expected to reach production models sooner or later.

TE Connectivity initially thought of printing a model of a motorcycle as a display of sculpting skills. This had already been done, several times over. The idea of a functioning bike was born in the process, probably out of the realization that it could actually be done. After all, the first printed car was unveiled and driven in public just last September.

3D printing technology is advancing by leaps and bounds, having progressed in just a few years from forming simple ornamental plastic parts to generating dynamic structures that function within moving mechanisms. In this sense, this motorcycle that looks like a child’s toy may well prove to be a landmark product.

Sources: TE Connectivity, 3DPrint.com