sid_melo blogreen: 09/15/14

segunda-feira, 15 de setembro de 2014

Google Launches Effort to Build Its Own Quantum Computer

Google’s crack at a quantum computer is a bid to change computing forever.

By Tom Simonite on September 3, 2014

Why It Matters

Practical quantum computers could solve problems that would take conventional machines millions of years.

qubit wafer

Quantum core: Techniques developed at the University of California, Santa Barbara, to build this device, known as a qubit, will be used to try to build a working quantum computer at Google.

Google is about to begin designing and building hardware for a quantum computer, a type of machine that can exploit quantum physics to solve problems that would take a conventional computer millions of years.

Since 2009, Google has been working with controversial startup D-Wave Systems, which claims to make “the first commercial quantum computer.” And last year Google purchased one of D-Wave’s machines. But independent tests published earlier this year found no evidence that D-Wave’s computer uses quantum physics to solve problems more efficiently than a conventional machine.

Now John Martinis, a professor at University of California, Santa Barbara, has joined Google to establish a new quantum hardware lab near the university. He will try to make his own versions of the kind of chip inside a D-Wave machine.

Martinis has spent more than a decade working on a more proven approach to quantum computing, and built some of the largest, most error-free systems of qubits, the basic building blocks that encode information in a quantum computer.

“We would like to rethink the design and make the qubits in a different way,” says Martinis of his effort to improve on D-Wave’s hardware. “We think there’s an opportunity in the way we build our qubits to improve the machine.” Martinis has taken a joint position with Google and UCSB that will allow him to continue his own research at the university.

Quantum computers could be immensely faster than any existing computer at certain problems. That’s because qubits working together can use the quirks of quantum mechanics to quickly discard incorrect paths to a solution and home in on the correct one. However, qubits are tricky to operate because quantum states are so delicate.

Chris Monroe, a professor who leads a quantum computing lab at the University of Maryland, welcomed the news that one of the leading lights in the field was going to work on the question of whether designs like D-Wave’s can be useful. “I think this is a great development to have legitimate researchers give it a try,” he says.

Since showing off its first machine in 2007, D-Wave has irritated academic researchers by making claims for its computers without providing the evidence its critics say is needed to back them up. However, the company has attracted over $140 million in funding and sold several of its machines (see “The CIA and Jeff Bezos Bet on Quantum Computing”).

There is no question that D-Wave’s machine can perform calculations. And research published in 2011 showed that the machine’s chip harbors the right kind of quantum physics needed for quantum computing. But evidence is lacking that it uses that physics in the way needed to unlock the huge speedups promised by a quantum computer. It could be solving problems using only ordinary physics.

Martinis’s previous work has been focused on the conventional approach to quantum computing. He set a new milestone in the field this April, when his lab announced that it could operate five qubits together with relatively low error rates. Larger systems of such qubits could be configured to run just about any kind of algorithm depending on the problem at hand, much like a conventional computer. To be useful, a quantum computer would probably need to be built with tens of thousands of qubits or more.

The chip at the heart of D-Wave’s latest machine has 512 qubits, but they are wired into a different, more limited, component known as a quantum annealer. It can only run a specific algorithm used for a specific kind of problem that requires selecting the best option in a situation with many competing requirements—for example, determining the most efficient delivery route around a city.

Martinis was a coauthor on a paper published in Science earlier this year that took the most rigorous independent look at a D-Wave machine yet. It concluded that in the tests run on the computer, there was “no evidence of quantum speedup.” Without that, critics say, D-Wave is nothing more than an overhyped, and rather weird, conventional computer. The company counters that the tests of its machine involved the wrong kind of problems to demonstrate its benefits.

Martinis’s work on D-Wave’s machine led him into talks with Google, and to his new position. Theory and simulation suggest that it might be possible for annealers to deliver quantum speedups, and he considers it an open question. “There’s some really interesting science that people are trying to figure out,” he says.

Martinis thinks his technology for fabricating qubits could make better quantum annealers. Specifically, he hopes to make one whose qubits can more stably maintain a quantum state known as a superposition—effectively both 0 and 1 at the same time. The qubits of D-Wave’s machine can maintain superpositions for periods lasting only nanoseconds. Martinis has built qubits that can do that for as long as 30 microseconds, he says.

Martinis makes his qubits from aluminum circuits built on sapphire wafers and chills them to 20 millikelvin—a fraction above absolute zero—so that they become superconducting. D-Wave’s chip requires similar cooling to operate, but has circuits made from a superconducting material called niobium, on top of silicon wafers. Martinis is in the process of switching to making his own qubits on silicon, and believes certain electrical insulator materials used in D-Wave’s chips may be limiting its performance.

However, Google has not given up on D-Wave. In an online statement, the leader of Google’s quantum research said that the two companies will continue to work together, and that Google’s D-Wave computer will be upgraded with a new 1,000 qubit processor when it becomes available.

Marijuana users who feel low get high

September 15, 2014

Journal of Studies on Alcohol and Drugs

Adolescents and young adults who smoke marijuana frequently may attempt to manage negative moods by using the drug, according to a study. "One of the challenges is that people often may use marijuana to feel better but may feel worse afterward," the lead investigator says. "Marijuana use can be associated with anxiety and other negative states. People feel bad, they use, and they might momentarily feel better, but then they feel worse. They don't necessarily link feeling bad after using with the use itself, so it can become a vicious circle."

Adolescents and young adults who smoke marijuana frequently may attempt to manage negative moods by using the drug, according to a study in September's Journal of Studies on Alcohol and Drugs.

"Young people who use marijuana frequently experience an increase in negative affect in the 24 hours leading up to a use event, which lends strong support to an affect-regulation model in this population," says the study's lead author Lydia A. Shrier, M.D., M.P.H., of the division of adolescent and young adult medicine at Boston Children's Hospital.

She notes that using marijuana as a coping technique for negative affect may make it harder for people to stop using the drug.

"One of the challenges is that people often may use marijuana to feel better but may feel worse afterward," she says. "Marijuana use can be associated with anxiety and other negative states. People feel bad, they use, and they might momentarily feel better, but then they feel worse. They don't necessarily link feeling bad after using with the use itself, so it can become a vicious circle."

For the study, Shrier and colleagues recruited 40 people, ages 15 to 24, who used marijuana at least twice a week, although their average was 9.7 times per week. They were trained to use a handheld computer that signaled them at a random time within three-hour intervals (four to six times per day) for two weeks. At each signal, participants were asked about their mood, companionship, perceived availability of marijuana, and recent marijuana use. Participants were also asked to report just before and just after any marijuana use. They completed more than 3,600 reports.

The researchers found that negative affect was significantly increased during the 24 hours before marijuana use compared with other periods. However, positive affect did not vary in the period before marijuana use compared with other times.

Also, neither the availability of marijuana nor the presence of friends modified the likelihood that chronic users would use marijuana following a period of negative affect.

The study is unique in that it collected data in real time to assess mood and marijuana use events. The study thus was able to identify mood that was occurring in the 24 hours before marijuana use and compared it with mood at other times, Shrier reports.

"There are a host of limitations with retrospective assessments, such as asking people 'the last time you used marijuana, why did you use it?'" according to Shrier. "We weren't asking people to predict anything or to recall anything -- we were just asking them to give us reports about how they were feeling right now. We were able to put under a microscope the association between those feelings and subsequent marijuana use."

Shrier says it could be beneficial for clinicians and counselors to help their patients identify patterns of negative affect and to implement alternative mood-regulation strategies to replace marijuana use.

Story Source:

The above story is based on materials provided by Journal of Studies on Alcohol and Drugs. Note: Materials may be edited for content and length.

Journal Reference:

Shrier, L. A., Ross, C. S., & Blood, E. A. Momentary positive and negative affect preceding marijuana use events in youth. Journal of Studies on Alcohol and Drugs, September 2014

New way to predict hurricane strength, destruction

A new study by Florida State University researchers demonstrates a different way of projecting a hurricane's strength and intensity that could give the public a better idea of a storm's potential for destruction.

Vasu Misra, associate professor of meteorology and co-director of the Florida Climate Institute, and fourth-year doctoral student Michael Kozar introduce in the Monthly Weather Review of the American Meteorological Society a new statistical model that complements hurricane forecasting by showing the size of storms, not just the wind speed.

The model predicts the amount of integrated kinetic energy within Atlantic tropical cyclones. This kinetic energy metric is related to the overall size and strength of a storm, not just the maximum wind speed. Predictions of this metric complement existing forecasting tools, potentially allowing forecasters to better assess the risk of hurricanes that make landfall.

"We don't perceive this to be an alternative to how storms are explained to the public, but a complement," Misra said.

Hurricane forecasts have traditionally focused on wind speeds as measured through the Saffir-Simpson Hurricane Wind Scale. For example, a storm that has wind speeds of 74 to 95 miles per hour would be called a Category 1 storm. A hurricane with wind speeds of 157 miles per hour or higher would be listed as a Category 5.

However, some of the most destructive hurricanes to hit the United States have been labeled a Category 1 or Category 2 because of their slower wind speeds.

Hurricane Ike, for example, was a category two storm when it made landfall in 2008, meaning it had maximum sustained winds of 96 to 110 miles per hour. Despite the modest rating on the Saffir-Simpson Hurricane Wind Scale, Hurricane Ike caused widespread destruction because it was such a large storm.

"When the National Hurricane Center says Category 1, the attitude by the public is that it's fine and they can live through it," Misra said. "But, the damage by flooding is typically more widespread in larger storms."

Added Kozar: "It's the wind that gets all the attention, but it's the flooding that causes much of the damage."

Kozar and Misra's work thus far has focused on using data on storms dating back to 1990. The next step in their research is to focus on real-time weather prediction, so they can show the model in action.

The research is supported by funding from NOAA and the U.S. Department of Agriculture.

Story Source:

The above story is based on materials provided by Florida State University. Note: Materials may be edited for content and length.

Journal Reference:

Michael E. Kozar and Vasubandhu Misra. Statistical Prediction of Integrated Kinetic Energy in North Atlantic Tropical Cyclones. Monthly Weather Review, 2014 (in press) DOI: 10.1175/MWR-D-14-00117.1

Protein secrets of Ebola virus

Click to enlarge

The current Ebola virus outbreak in West Africa, which has claimed more than 2000 lives, has highlighted the need for a deeper understanding of the molecular biology of the virus that could be critical in the development of vaccines or antiviral drugs to treat or prevent Ebola hemorrhagic fever. Now, a team at the University of Virginia (UVA), USA -- under the leadership of Dr Dan Engel, a virologist, and Dr Zygmunt Derewenda, a structural biologist -- has obtained the crystal structure of a key protein involved in Ebola virus replication, the C-terminal domain of the Zaire Ebola virus nucleoprotein (NP).

The team explains that their structure reveals a novel tertiary fold that is expected to lead to insights into how the viral nucleocapsid is assembled in infected cells. The structure could also provide a basis for the design of drugs to halt infection in humans. "The structure is unique in the RNA virus world," Derewenda explains. "It is not found in viruses that cause influenza, rabies or other diseases." It distantly resembles the β-grasp protein motif found in ubiquitin, most likely the result of convergent evolution.

Like many other related viruses, Ebola virus contains a negative-sense, single-stranded RNA that encodes seven different proteins, one of which is known as the nucleoprotein (NP) for its ability to interact with the viral RNA genome. It is the most abundant viral protein found in infected cells and also inside the viral nucleocapsid. While five of the seven viral proteins have succumbed to structural characterization by X-ray crystallography, NP so far has resisted such attempts, although analogous proteins from other viruses have had their structures analysed.

The UVA team produced the Ebola protein using an engineered form of Escherichia coli bacteria as a protein factory. This allowed them to identify the boundaries of two globular domains and to crystallize the unique C-terminal domain spanning amino-acid residues 641 to 739. The study revealed a molecular architecture unseen so far among known proteins, the team says. There is existing evidence that the newly characterized domain is involved in transcription and the self-assembly of the viral nucleocapsid. As such, the results obtained by the UVA team will be useful in deciphering precisely how these various functions are accomplished by the virus; such a detailed description offers up a potential target for the design of anti-viral drugs.

Story Source:

The above story is based on materials provided by International Union of Crystallography. Note: Materials may be edited for content and length.

Journal Reference:

Paulina J. Dziubańska, Urszula Derewenda, Jeffrey F. Ellena, Daniel A. Engel, Zygmunt S. Derewenda. The structure of the C-terminal domain of theZaire ebolavirusnucleoprotein. Acta Crystallographica Section D Biological Crystallography, 2014; 70 (9): 2420 DOI: 10.1107/S1399004714014710

Scientists come closer to the industrial synthesis of a material harder than diamond

Click to enlarge

Diamond anvils malformed during synthesis of ultrahard fullerite. Note the dent in the center.

Researchers from the Technological Institute for Superhard and Novel Carbon Materials in Troitsk, MIPT, MISiS, and MSU have developed a new method for the synthesis of an ultrahard material that exceeds diamond in hardness. An article recently published in the journal Carbon describes in detail a method that allows for the synthesis of ultrahard fullerite, a polymer composed of fullerenes, or spherical molecules made of carbon atoms.

In their work, the scientists note that diamond hasn't been the hardest material for some time now. Natural diamonds have a hardness of nearly 150 GPa, but ultrahard fullerite has surpassed diamond to become first on the list of hardest materials with values that range from 150 to 300 GPa.

All materials that are harder than diamond are called ultra hard materials. Materials softer than diamond but harder than boron nitride are termed superhard. Boron nitride, with its cubic lattice, is almost three times harder than the well-known corundum.

Fullerites are materials that consist of fullerenes. In their turn, fullerenes are carbon molecules in the form of spheres consisting of 60 atoms. Fullerene was first synthesized more than 20 years ago, and a Nobel Prize was awarded for that work. The carbon spheres within fullerite can be arranged in different ways, and the material's hardness largely depends on just how interconnected they are. In the ultrahard fullerite discovered by the workers at the Technological Institutefor Superhard and Novel Carbon Materials (FSBITISNCM), C₆₀ molecules are interconnected by covalent bonds in all directions, a material scientists call a three-dimensional polymer.

However, the methods providing production of this promising material on an industrial scale are not available yet. Practically, the superhard carbon form is of primary interest for specialists in the field of metals and other materials processing: the harder a tool is, the longer it works, and the more qualitatively the details can be processed.

What makes synthesizing fullerite in large quantities so difficult is the high pressure required for the reaction to begin. Formation of the three-dimensional polymer begins at a pressure of 13 GPa, or 130,000 atm. But modern equipment cannot provide such pressure on a large scale.

The scientists in the current study have shown that adding carbon disulfide (CS₂ ) to the initial mixture of reagents can accelerate fullerite synthesis. This substance is synthesized on an industrial scale, is actively used in various enterprises, and the technologies for working with it are well-developed. According to experiments, carbon disulfide is an end product, but here it acts as an accelerator. Using CS₂ , the formation of the valuable superhard material becomes possible even if the pressure is lower and amounts to 8GPa. In addition, while previous efforts to synthesize fullerite at a pressure of 13 GPa required heating up to 1100K (more than 820 degrees Celsius),in the present case it occurs at room temperature.

"The discovery described in this article (the catalytic synthesis of ultrahard fullerite) will create a new research area in materials science because it substantially reduces the pressure required for synthesis and allows for manufacturing the material and its derivatives on an industrial scale," explained Mikhail Popov, the leading author of the research and the head of the laboratory of functional nanomaterials at FSBI TISNCM.

Story Source:

The above story is based on materials provided by Moscow Institute of Physics and Technology. Note: Materials may be edited for content and length.

Journal Reference:

M. Popov, V. Mordkovich, S. Perfilov, A. Kirichenko, B. Kulnitskiy, I. Perezhogin, V. Blank. Synthesis of ultrahard fullerite with a catalytic 3D polymerization reaction of C60. Carbon, 2014; 76: 250 DOI: 10.1016/j.carbon.2014.04.075

Lack of sleep America's top health problem, doctors say

In this story:

ATLANTA (CNN) -- Sleep apnea, narcolepsy, insomnia: these are just a few of the recognized disorders that keep their afflicted from getting enough sleep. Nearly half of all Americans have difficulty sleeping.

Some people may show great bravado about getting a job done on little sleep. Some even brag about having trouble sleeping, claiming their work proves they didn't need the rest anyway. Yet the truth is that fatigue is dangerous. A growing collection of research indicates that America's sleep problems have reached epidemic proportions, and may be the country's number-one health problem.

The costs of not sleeping

We don't know what sleep is. We do know we need it to survive. Sleep restores us. Those who sleep fewer than six hours a night don't live as long as those who sleep seven hours or more.

Lack of sleep can be expensive: The National Commission on Sleep Disorders estimates that sleep deprivation costs $150 billion a year in higher stress and reduced workplace productivity.

It may also lead to personal and public tragedy. There are indications that the Challenger disaster, the Chernobyl nuclear reactor meltdown and the Exxon Valdez oil spill can all be partly linked to people suffering from a severe lack of sleep.

High-risk careers associated with little sleep

Dr. Serena Koenig, 13 hours into a 36-hour shift at Brigham and Women's Hospital in Boston, admits that her grueling schedule allows no room for error.

"You do not have the luxury of being tired. You have to take care of that patient," she said. "If you make a mistake, that patient could be hurt by it and the fear of making mistakes keeps you clear thinking. I have never made a mistake because I have been tired."

Her hospital pays close attention to problems associated with sleep deprivation among health care workers, but only recent research has shown that sleeplessness is a major problem in many fields of work.

Pete Filbrick has been a truck driver for 30 years. He, too, has never made a mistake. But he knows what can happen.

"I haven't seen the figures on that, but I would think fatigue would play a pretty big role in almost any accident," Filbrick said.

Figures suggest that driver fatigue contributes to 30 to 40 percent of all heavy truck accidents. Many truckers simply can't recognize the point that their bodies are tired enough for them to fall asleep.

ScienceLives Interview with Teresa Woodruff

As a reproductive endocrinologist, Teresa Woodruff has spent the better part of her research career focusing on female reproductive health and infertility. As founder and director of the Institute for Women's Health Research, Woodruff has been an advocate for gender specificity in clinical trials, as a way to better understand the effects that various technologies and procedures have on women. As an educator and mentor, she encourages young women to pursue careers in the sciences, and helped develop the Oncofertility Saturday Academy to involve high school girls in college-level science. Credit: NSF

To better understand vertebrae, John Long's team studies real sharks to produce mechanical ones

Dive in with NSF-funded researcher John Long and his robotic sharks. A professor at Vassar College, Long, along with his team, studies real live sharks and their vertebral columns. The researchers then take their findings and design computer models and artificial vertebral columns to understand sharks' movement and biomechanics.

Hangover Helper Spinach and Pineapple Smoothie

- Jasmina for Getty Images

Jasmina for Getty Images

This fast hangover helper smoothie is a great antidote to last night's overindulgences. Coconut water, spinach and pineapple with a touch of lime rehydrate the system rapidly and give your aching body a jolt of energy. Alcohol can leave us dehydrated; 15 minutes after drinking this you should notice a marked difference win your energy. It is full of digestion-boosting enzymes, anti-inflammatory phytonutrients, and liver cleansing citrus. Spinach provides massive doses of Vitamin K, A, C, the B vitamins and minerals, while pineapple bumps the vitamin C content of the smoothie to well over 100% of the RDA per serving. The combination of spinach and pineapple also delivers an excellent dose of manganese, a mineral that protects against free radical damage, balances our blood sugar and protects our skin and bone health matrix.

Ceramics don't have to be brittle: Incredibly light, strong materials recover original shape after being smashed

September 11, 2014

California Institute of Technology

Materials scientists have developed a method for creating new structural materials by taking advantage of the unusual properties that solids can have at the nanometer scale. They have used the method to produce a ceramic (e.g., a piece of chalk or a brick) that contains about 99.9 percent air yet is incredibly strong and can recover its original shape after being smashed by more than 50 percent.

Click to enlarge

This sequence shows how the Greer Lab's three-dimensional, ceramic nanolattices can recover after being compressed by more than 50 percent. Clockwise, from left to right, an alumina nanolattice before compression, during compression, fully compressed, and recovered following compression.

Imagine a balloon that could float without using any lighter-than-air gas. Instead, it could simply have all of its air sucked out while maintaining its filled shape. Such a vacuum balloon, which could help ease the world's current shortage of helium, can only be made if a new material existed that was strong enough to sustain the pressure generated by forcing out all that air while still being lightweight and flexible.

Caltech materials scientist Julia Greer and her colleagues are on the path to developing such a material and many others that possess unheard-of combinations of properties. For example, they might create a material that is thermally insulating but also extremely lightweight, or one that is simultaneously strong, lightweight, and nonbreakable -- properties that are generally thought to be mutually exclusive.

Greer's team has developed a method for constructing new structural materials by taking advantage of the unusual properties that solids can have at the nanometer scale, where features are measured in billionths of meters. In a paper published in the September 12 issue of the journal Science, the Caltech researchers explain how they used the method to produce a ceramic (e.g., a piece of chalk or a brick) that contains about 99.9 percent air yet is incredibly strong, and that can recover its original shape after being smashed by more than 50 percent.

"Ceramics have always been thought to be heavy and brittle," says Greer, a professor of materials science and mechanics in the Division of Engineering and Applied Science at Caltech. "We're showing that in fact, they don't have to be either. This very clearly demonstrates that if you use the concept of the nanoscale to create structures and then use those nanostructures like LEGO to construct larger materials, you can obtain nearly any set of properties you want. You can create materials by design."

The researchers use a direct laser writing method called two-photon lithography to "write" a three-dimensional pattern in a polymer by allowing a laser beam to crosslink and harden the polymer wherever it is focused. The parts of the polymer that were exposed to the laser remain intact while the rest is dissolved away, revealing a three-dimensional scaffold. That structure can then be coated with a thin layer of just about any kind of material -- a metal, an alloy, a glass, a semiconductor, etc. Then the researchers use another method to etch out the polymer from within the structure, leaving a hollow architecture.

The applications of this technique are practically limitless, Greer says. Since pretty much any material can be deposited on the scaffolds, the method could be particularly useful for applications in optics, energy efficiency, and biomedicine. For example, it could be used to reproduce complex structures such as bone, producing a scaffold out of biocompatible materials on which cells could proliferate.

In the latest work, Greer and her students used the technique to produce what they call three-dimensional nanolattices that are formed by a repeating nanoscale pattern. After the patterning step, they coated the polymer scaffold with a ceramic called alumina (i.e., aluminum oxide), producing hollow-tube alumina structures with walls ranging in thickness from 5 to 60 nanometers and tubes from 450 to 1,380 nanometers in diameter.

Greer's team next wanted to test the mechanical properties of the various nanolattices they created. Using two different devices for poking and prodding materials on the nanoscale, they squished, stretched, and otherwise tried to deform the samples to see how they held up.

They found that the alumina structures with a wall thickness of 50 nanometers and a tube diameter of about 1 micron shattered when compressed. That was not surprising given that ceramics, especially those that are porous, are brittle. However, compressing lattices with a lower ratio of wall thickness to tube diameter -- where the wall thickness was only 10 nanometers -- produced a very different result.

"You deform it, and all of a sudden, it springs back," Greer says. "In some cases, we were able to deform these samples by as much as 85 percent, and they could still recover."

To understand why, consider that most brittle materials such as ceramics, silicon, and glass shatter because they are filled with flaws -- imperfections such as small voids and inclusions. The more perfect the material, the less likely you are to find a weak spot where it will fail. Therefore, the researchers hypothesize, when you reduce these structures down to the point where individual walls are only 10 nanometers thick, both the number of flaws and the size of any flaws are kept to a minimum, making the whole structure much less likely to fail.

"One of the benefits of using nanolattices is that you significantly improve the quality of the material because you're using such small dimensions," Greer says. "It's basically as close to an ideal material as you can get, and you get the added benefit of needing only a very small amount of material in making them."

The Greer lab is now aggressively pursuing various ways of scaling up the production of these so-called meta-materials.

California Institute of Technology. "Ceramics don't have to be brittle: Incredibly light, strong materials recover original shape after being smashed." ScienceDaily. ScienceDaily, 11 September 2014. <www.sciencedaily.com/releases/2014/09/140911135450.htm>.

Story Source:

The above story is based on materials provided by California Institute of Technology. The original article was written by Kimm Fesenmaier. Note: Materials may be edited for content and length.

Journal Reference:

L. R. Meza, S. Das, J. R. Greer. Strong, lightweight, and recoverable three-dimensional ceramic nanolattices. Science, 2014; 345 (6202): 1322 DOI: 10.1126/science.1255908

Dendritic cells affect onset, progress of psoriasis

Different types of dendritic cells in human skin have assorted functions in the early and more advanced stages of psoriasis report researchers in the journal EMBO Molecular Medicine. The scientists suggest that new strategies to regulate the composition of dendritic cells in psoriatic skin lesions might represent an approach for the future treatment of the disease.

"We urgently need new ways to treat psoriasis, treatments that will deliver improved benefits to patients and reduce the incidence of known side effects for existing drugs," says EMBO Member Maria Sibilia, a Professor at the Medical University of Vienna in Austria, and one of the lead authors of the study. "Our experiments have revealed that increases in the number of plasmacytoid dendritic cells are important early triggers of the disease while other types of dendritic cells, the Langerhans cells, help to protect the balance of the immune response that is established during inflammation of the skin."

Psoriasis is an autoimmune disease that affects around 125 million people worldwide. Symptoms, which include the formation of red inflamed lesions that appear on the skin, vary from mild to severe. The disease is often associated with other serious health conditions such as diabetes, heart disease and depression.

The researchers observed an increase in the accumulation of plasmacytoid dendritic cells in the psoriatic lesions of patients as well as in mice that are model organisms for the study of the disease. Plasmacytoid dendritic cells are a specific type of immune cell that can infiltrate damaged tissue during the early phase of psoriasis. In contrast, the levels of another type of dendritic cells known as Langerhans cells, were significantly decreased in the lesions compared to healthy skin in humans and mice. If the levels of plasmacytoid dendritic cells in mice were decreased during the early stages of the disease then the symptoms of psoriasis were quelled. A similar decrease in Langerhans cells at an early stage of the disease had no effect. If the levels of Langerhans cells were reduced at advanced stages of the disease, the symptoms of psoriasis were exacerbated.

"The changes in the severity of symptoms we have observed related to changes in the composition of dendritic cells most likely impact the balance of inflammatory mediators at the site of disease. It may well be that by inducing favourable compositions of dendritic cells at the early stages of psoriasis we may be able to help reduce the effects of psoriasis by achieving a better balance of these mediators at the site of the disease. Further work is needed before we can say with any certainty if such an approach will lead to a viable clinical treatment for psoriasis."

Story Source:

The above story is based on materials provided by EMBO. Note: Materials may be edited for content and length.

Journal Reference:

Elisabeth Glitzner, Ana Korosec, Patrick M. Brunner, Barbara Drobits, Nicole Amberg, Helia B. Schonthaler, Tamara Kopp, Erwin F. Wagner, Georg Stingl, Martin Holcmann and Maria Sibilia. Specific roles for dendritic cell subsets during initiation and progression of psoriasis. EMBO Molecular Medicine, September 2014 DOI: 10.15252/emmm.201404114

Anemia: One-minute point-of-care test shows promise in new study

Erika Tyburski is shown with a prototype device for point-of-care testing of anemia. The device could enable more rapid diagnosis of the common blood disorder and allow inexpensive at-home self-monitoring of persons with chronic forms of the disease.

Credit: Gary Meek

The disposable self-testing device analyzes a single droplet of blood using a chemical reagent that produces visible color changes corresponding to different levels of anemia. The basic test produces results in about 60 seconds and requires no electrical power. A companion smartphone application can automatically correlate the visual results to specific blood hemoglobin levels.

By allowing rapid diagnosis and more convenient monitoring of patients with chronic anemia, the device could help patients receive treatment before the disease becomes severe, potentially heading off emergency room visits and hospitalizations. Anemia, which affects two billion people worldwide, is now diagnosed and monitored using blood tests done with costly test equipment maintained in hospitals, clinics or commercial laboratories.

Because of its simplicity and ability to deliver results without electricity, the device could also be used in resource-poor nations.

A paper describing the device and comparing its sensitivity to gold-standard anemia testing was published August 30 in The Journal of Clinical Investigation. Development of the test has been supported by the FDA-funded Atlantic Pediatric Device Consortium, the Georgia Research Alliance, Children's Healthcare of Atlanta, the Georgia Center of Innovation for Manufacturing and the Global Center for Medical Innovation.

"Our goal is to get this device into patients' hands so they can diagnose and monitor anemia themselves," said Dr. Wilbur Lam, senior author of the paper and a physician in the Aflac Cancer and Blood Disorders Center at Children's Healthcare of Atlanta and the Department of Pediatrics at the Emory University School of Medicine. "Patients could use this device in a way that's very similar to how diabetics use glucose-monitoring devices, but this will be even simpler because this is a visual-based test that doesn't require an additional electrical device to analyze the results."

The test device was developed in a collaboration of Emory University, Children's Healthcare of Atlanta and the Georgia Institute of Technology -- all based in Atlanta. It grew out of a 2011 undergraduate senior design project in the Wallace H. Coulter Department of Biomedical Engineering at Georgia Tech and Emory University. In 2013, it was among the winners of Georgia Tech's InVenture Prize, an innovation competition for undergraduate students, and won first place in the Ideas to SERVE Competition in Georgia Tech's Scheller College of Business.

Using a two-piece prototype device, the test works this way: A patient sticks a finger with a lance similar to those used by diabetics to produce a droplet of blood. The device's cap, a small vial, is then touched to the droplet, drawing in a precise amount of blood using capillary action. The cap containing the blood sample is then placed onto the body of the clear plastic test kit, which contains the chemical reagent. After the cap is closed, the device is briefly shaken to mix the blood and reagent.

"When the capillary is filled, we have a very precise volume of blood, about five microliters, which is less than a droplet -- much less than what is required by other anemia tests," explained Erika Tyburski, the paper's first author and leader of the undergraduate team that developed the device.

Blood hemoglobin then serves as a catalyst for a reduction-oxidation reaction that takes place in the device. After about 45 seconds, the reaction is complete and the patient sees a color ranging from green-blue to red, indicating the degree of anemia.

A label on the device helps with interpretation of the color, or the device could be photographed with a smartphone running an application written by Georgia Tech undergraduate student Alex Weiss and graduate student William Stoy. The app automatically correlates the color to a specific hemoglobin level, and could one day be used to report the data to a physician.

To evaluate sensitivity and specificity of the device, Tyburski studied blood taken from 238 patients, some of them children at Children's Healthcare of Atlanta and the others adults at Emory University's Winship Cancer Institute. Each blood sample was tested four times using the device, and the results were compared to reports provided by conventional hematology analyzers.

The work showed that the results of the one-minute test were consistent with those of the conventional analysis. The smartphone app produced the best results for measuring severe anemia.

"The test doesn't require a skilled technician or a draw of venous blood and you see the results immediately," said Lam, who is also an assistant professor in the Coulter Department of Biomedical Engineering. "We think this is an empowering system, both for the general public and for our patients."

Tyburski and Lam have teamed up with two other partners and worked with Emory's Office of Technology Transfer to launch a startup company, Sanguina, to commercialize the test, which will be known as AnemoCheck™. The test ultimately will require approval from the FDA. The team also plans to study how the test may be applied to specific diseases, such as sickle cell anemia -- which is common in Georgia.

The device could be on pharmacy shelves sometime in 2016, where it might help people like Tyburski, who has suffered mild anemia most of her life. "If I'd had this when I was kid, I could have avoided some trips to the emergency room when I passed out in gym class," she said.

About a third of the population is at risk for anemia, which can cause neurocognitive deficits in children, organ failure and less serious effects such as chronic fatigue. Women, children, the elderly and those with chronic conditions such as kidney disease are more likely to suffer from anemia.

Georgia Institute of Technology. "Anemia: One-minute point-of-care test shows promise in new study." ScienceDaily. ScienceDaily, 12 September 2014. <www.sciencedaily.com/releases/2014/09/140912085108.htm>.

Protein appears to protect against bone loss in arthritis

September 12, 2014

Medical College of Georgia at Georgia Regents University

A small protein named GILZ appears to protect against the bone loss that often accompanies arthritis and its treatment, researchers report. Arthritis as well as aging prompt the body to make more fat than bone, and the researchers have previously shown GILZ can restore a more youthful, healthy mix. It also tamps down inflammation, a major factor in arthritis, they say.

A small protein named GILZ appears to protect against the bone loss that often accompanies arthritis and its treatment, researchers report.

Arthritis as well as aging prompt the body to make more fat than bone, and the researchers have previously shown GILZ can restore a more youthful, healthy mix. It also tamps down inflammation, a major factor in arthritis.

Now they have early evidence that GILZ might one day be a better treatment option for arthritis patients than widely used synthetic glucocorticoids, which actually increase bone loss, said Dr. Xingming Shi, bone biologist at the Medical College of Georgia at Georgia Regents University.

Their research is being presented at The American Society for Bone and Mineral Research 2014 Annual Meeting Sept. 12-15 in Houston.

In addition to bone loss, glucocorticoids, such as prednisone, produce other side effects, including diabetes. While GILZ is induced by glucocorticoids, directly overexpressing the protein appears to better target sources of bone loss and inflammation and avoid these serious side effects. .

For this study, the focus was tumor necrosis factor alpha, a proinflammatory cytokine that helps regulate immune cells and is a major player in arthritis. Tumor necrosis factor alpha primarily works though promoting inflammation, which is great if the target is cancer. However, when tumor necrosis factor alpha becomes dysregulated, it can also cause diseases like arthritis and inflammatory bowel disease.

To look specifically at the impact on bone loss, the researchers crossed mice bred to overexpress tumor necrosis factor alpha throughout the body with mice that overexpressed GILZ in just their mesenchymal stem cells. These stem cells produce the osteoblasts, which make bone. They also make fat, and when the cells stop making as much bone, they tend to make more of it. Shi's lab has shown that GILZ can coax mesenchymal stem cells back to making more bone and less fat.

While the mice that overexpressed only tumor necrosis factor alpha quickly developed arthritis along with significant bone and weight loss, those that also overexpressed GILZ had significantly less bone loss, Shi said.

"Our previous studies have shown that the GILZ transgenic mouse can make more bone," said Dr. Nianlan Yang, MCG postdoctoral fellow. "We wanted to see if GILZ would still have a bone protective effect in an inflammatory environment similar to arthritis."

Next steps include developing an oral medication, a peptide specifically, that increases GILZ expression rather than the genetic alterations the researchers have used in animal models, said Yang. She just completed a National Arthritis Foundation fellowship, which helped support that effort. They also want to see if GILZ can prevent arthritis from developing in the face of inflammation.

Glucocorticoids and GILZ are both produced naturally in the body. Glucocorticoids are steroid hormones that help regulate the body's use of the fuel glucose and dampen the immune response.

Medical College of Georgia at Georgia Regents University. "Protein appears to protect against bone loss in arthritis." ScienceDaily. ScienceDaily, 12 September 2014. www.sciencedaily.com/releases/2014/09/140912112423.htm

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The above story is based on materials provided by Medical College of Georgia at Georgia Regents University. Note: Materials may be edited for content and length.