Humans were already recycling 13,000 years ago, burnt artifacts show

ScienceDaily (Sep. 20, 2012) — A study at the Universitat Rovira i Virgili and the Catalan Institute of Human Paleoecology and Social Evolution (IPHES) reveals that humans from the Upper Palaeolithic Age recycled their stone artefacts to be put to other uses. The study is based on burnt artefacts found in the Molí del Salt site in Tarragona, Spain.

The recycling of stone tools during Prehistoric times has hardly been dealt with due to the difficulties in verifying such practices in archaeological records. Nonetheless, it is possible to find some evidence, as demonstrated in a study published in the 'Journal of Archaeological Science'.

"In order to identify the recycling, it is necessary to differentiate the two stages of the manipulation sequence of an object: the moment before it is altered and the moment after. The two are separated by an interval in which the artefact has undergone some form of alteration. This is the first time a systematic study of this type has been performed," as explained to SINC by Manuel Vaquero, researcher at the Universitat Rovira i Virgili.

The archaeologists found a high percentage of burnt remains in the Molí del Salt site (Tarragona), which date back to the end of the Upper Palaeolithic Age some 13,000 years ago. The expert ensures that "we chose these burnt artefacts because they can tell us in a very simple way whether they have been modified after being exposed to fire."

The results indicate that the recycling of tools was normal during the Upper Palaeolithic Age. However, this practice is not documented in the same way as other types of artefacts. The use of recycled tools was more common for domestic activities and seems to be associated with immediate needs.

Recycling domestic tools

Recycling is linked to expedited behaviour, which means simply shaped and quickly available tools as and when the need arises. Tools used for hunting, like projectile points for instance, were almost never made from recycled artefacts. In contrast, double artefacts (those that combine two tools within the same item) were recycled more often.

"This indicates that a large part of these tools were not conceived from the outset as double artefacts but a single tool was made first and a second was added later when the artefact was recycled," outlines the researcher. The history of the artefacts and the sequence of changes that they have undergone over time are fundamental in understanding their final morphology.

According to Vaquero, "in terms of the objects, this is mostly important from a cultural value point of view, especially in periods like the Upper Palaeolithic Age, in which it is thought that the sharper the object the sharper the mind."

Sustainable practices with natural resources

Recycling could have been determinant in hunter-gatherer populations during the Palaeolithic Age if we consider the behaviour of current indigenous populations nowadays.

"It bears economic importance too, since it would have increased the availability of lithic resources, especially during times of scarcity. In addition, it is a relevant factor for interpreting sites because they become not just places to live but also places of resource provision," states the researcher.

Reusing resources meant that these humans did not have to move around to find raw materials to make their tools, a task that could have taken them far away from camp. "They would simply take an artefact abandoned by those groups who previously inhabited the site."

Vaquero and the team believe that this practice needs to be borne in mind when analysing the site. "Those populating these areas could have moved objects from where they were originally located. They even could have dug up or removed sediments in search of tools," highlights the researcher.

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The above story is reprinted from materials provided by Plataforma SINC, via AlphaGalileo.

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Journal Reference:

1. Manuel Vaquero, Susana Alonso, Sergio García-Catalán, Angélica García-Hernández, Bruno Gómez de Soler, David Rettig, María Soto. Temporal nature and recycling of Upper Paleolithic artifacts: the burned tools from the Molí del Salt site (Vimbodí i Poblet, northeastern Spain). Journal of Archaeological Science, 2012; 39 (8): 2785 DOI: 10.1016/j.jas.2012.04.024

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20 Sep, 2012

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Genetic mutation may have allowed early humans to migrate throughout Africa

ScienceDaily (Sep. 19, 2012) — A genetic mutation that occurred thousands of years ago might be the answer to how early humans were able to move from central Africa and across the continent in what has been called "the great expansion," according to new research from Wake Forest Baptist Medical Center.

By analyzing genetic sequence variation patterns in different populations around the world, three teams of scientists from Wake Forest Baptist, Johns Hopkins University School of Medicine and the University of Washington School of Medicine, Seattle, demonstrated that a critical genetic variant arose in a key gene cluster on chromosome 11, known as the fatty acid desaturase cluster or FADS, more than 85,000 years ago. This variation would have allowed early humans to convert plant-based polyunsaturated fatty acids (PUFAs) to brain PUFAs necessary for increased brain size, complexity and function. The FADS cluster plays a critical role in determining how effectively medium-chain PUFAs found in plants are converted to the long-chain PUFAs found in the brain.

This research is published online today in PLOS ONE.

Archeological and genetic studies suggest that homo sapiens appeared approximately 180,000 years ago, but stayed in one location around bodies of water in central Africa for almost 100,000 years. Senior author Floyd H. "Ski" Chilton, Ph.D., professor of physiology and pharmacology and director of the Center for Botanical Lipids and Inflammatory Disease Prevention at Wake Forest Baptist, and others have hypothesized that this location was critical, in part, because early humans needed large amounts of the long-chain PUFA docosahexaenoic acid (DHA), which is found in shellfish and fish, to support complex brain function.

"This may have kept early humans tethered to the water in central Africa where there was a constant food source of DHA," Chilton said. "There has been considerable debate on how early humans were able to obtain sufficient DHA necessary to maintain brain size and complexity. It's amazing to think we may have uncovered the region of genetic variation that arose about the time that early humans moved out of this central region in what has been called the 'great expansion.'"

Once this trait arose, the study shows that it was under intense selective pressure and thus rapidly spread throughout the population of the entire African continent. "The power of genetics continually impresses me, and I find it remarkable that we can make inferences about things that happened tens of thousands of years ago by studying patterns of genetic variation that exist in contemporary populations," said Joshua M. Akey, Ph.D., lead scientist at the University of Washington.

This conversion meant that early humans didn't have to rely on just one food source, fish, for brain growth and development. This may have been particularly important because the genetic variant arose before organized hunting and fishing could have provided more reliable sources of long-chain PUFAs, Akey said.

To investigate the evolutionary forces shaping patterns of variation in the FADS gene cluster in geographically diverse populations, the researchers analyzed 1,092 individuals representing 15 different human populations that were sequenced as part of the 1000 Genome Project and 1,043 individuals from 52 populations from the Human Genome Diversity Panel database. They focused on the FADS cluster because they knew those genes code for the enzymatic steps in long-chain PUFA synthesis that are the least efficient.

Chilton said the findings were possible because of the collaboration of internationally recognized scientists from three distinct and diverse disciplines -- fatty acid biochemistry (Wake Forest Baptist), statistical genetics (Johns Hopkins) and population genetics (University of Washington). This new information builds on Chilton's 2011 research findings published in BMC Genetics that showed how people of African descent have a much higher frequency of the gene variants that convert plant-based medium-chain omega-6 PUFAs found in cooking oils and processed foods to long-chain PUFAs that cause inflammation. Compared to Caucasians, African Americans in the United States have much higher rates of hypertension, type 2 diabetes, stroke, coronary heart disease and certain types of cancer. "The current observation provides another important clue as to why diverse racial and ethnic populations likely respond differently to the modern western diet," Chilton said.

This research was supported by National Institutes of Health grants, P50 AT002782 and a Clinical and Translational Science Award grant to The Johns Hopkins Medical Institutions. Additional support was received from the Wake Forest Health Sciences Center for Public Health Genomics. Additional support came from the Mary Beryl Patch Turnbull Scholar Program and the MOSAIC initiative of Johns Hopkins University.

Chilton has a financial interest in and is a consultant for Gene Smart Health. His potential conflict of interest is being institutionally managed by Wake Forest Baptist and outside sponsors, as appropriate. No other authors have a conflict of interest.

First author is Rasika Mathias, Sc.D, assistant professor of medicine and epidemiology, Johns Hopkins; contributing authors include Hannah C. Ainsworth and Susan Sergeant, both of Wake Forest Baptist; Wenqing Fu, U of W; Dara G. Torgerson, University of California San Francisco; and Ingo Ruczinski and Kathleen C. Barnes of Johns Hopkins.

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The above story is reprinted from materials provided by Wake Forest Baptist Medical Center.

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Journal Reference:

1. Rasika A. Mathias, Wenqing Fu, Joshua M. Akey, Hannah C. Ainsworth, Dara G. Torgerson, Ingo Ruczinski, Susan Sergeant, Kathleen C. Barnes, Floyd H. Chilton. Adaptive Evolution of the FADS Gene Cluster within Africa. PLoS ONE, 2012; 7 (9): e44926 DOI: 10.1371/journal.pone.0044926

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20 Sep, 2012

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Ancient tooth may provide evidence of early human dentistry

ScienceDaily (Sep. 19, 2012) — Researchers may have uncovered new evidence of ancient dentistry in the form of a 6,500-year-old human jaw bone with a tooth showing traces of beeswax filling, as reported Sept. 19 in the open access journal PLOS ONE.

The researchers, led by Federico Bernardini and Claudio Tuniz of the Abdus Salam International Centre for Theoretical Physics in Italy in cooperation with Sincrotrone Trieste and other institutions, write that the beeswax was applied around the time of the individual's death, but cannot confirm whether it was shortly before or after. If it was before death, however, they write that it was likely intended to reduce pain and sensitivity from a vertical crack in the enamel and dentin layers of the tooth.

According to Tuniz, the severe wear of the tooth "is probably also due to its use in non-alimentary activities, possibly such as weaving, generally performed by Neolithic females."

Evidence of prehistoric dentistry is sparse, so this new specimen, found in Slovenia near Trieste, may help provide insight into early dental practices.

"This finding is perhaps the most ancient evidence of pre-historic dentistry in Europe and the earliest known direct example of therapeutic-palliative dental filling so far," says Bernardini.

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1. Federico Bernardini, Claudio Tuniz, Alfredo Coppa, Lucia Mancini, Diego Dreossi, Diane Eichert, Gianluca Turco, Matteo Biasotto, Filippo Terrasi, Nicola De Cesare, Quan Hua, Vladimir Levchenko. Beeswax as Dental Filling on a Neolithic Human Tooth. PLoS ONE, 2012; 7 (9): e44904 DOI: 10.1371/journal.pone.0044904

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20 Sep, 2012

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Single-atom writer a landmark for quantum computing

ScienceDaily (Sep. 19, 2012) — A research team led by Australian engineers has created the first working quantum bit based on a single atom in silicon, opening the way to ultra-powerful quantum computers of the future.

In a landmark paper published September 19 in the journal Nature, the team describes how it was able to both read and write information using the spin, or magnetic orientation, of an electron bound to a single phosphorus atom embedded in a silicon chip.

"For the first time, we have demonstrated the ability to represent and manipulate data on the spin to form a quantum bit, or 'qubit', the basic unit of data for a quantum computer," says Scientia Professor Andrew Dzurak. "This really is the key advance towards realising a silicon quantum computer based on single atoms."

Dr Andrea Morello and Professor Dzurak from the UNSW School of Electrical Engineering and Telecommunications lead the team. It includes researchers from the University of Melbourne and University College, London.

"This is a remarkable scientific achievement -- governing nature at its most fundamental level -- and has profound implications for quantum computing," says Dzurak.

Dr Morello says that quantum computers promise to solve complex problems that are currently impossible on even the world's largest supercomputers: "These include data-intensive problems, such as cracking modern encryption codes, searching databases, and modelling biological molecules and drugs."

The new finding follows on from a 2010 study also published in Nature, in which the same UNSW group demonstrated the ability to read the state of an electron's spin. Discovering how to write the spin state now completes the two-stage process required to operate a quantum bit.

The new result was achieved by using a microwave field to gain unprecedented control over an electron bound to a single phosphorus atom, which was implanted next to a specially-designed silicon transistor. Professor David Jamieson, of the University of Melbourne's School of Physics, led the team that precisely implanted the phosphorus atom into the silicon device.

UNSW PhD student Jarryd Pla, the lead author on the paper, says: "We have been able to isolate, measure and control an electron belonging to a single atom, all using a device that was made in a very similar way to everyday silicon computer chips."

As Dr Morello notes: "This is the quantum equivalent of typing a number on your keyboard. This has never been done before in silicon, a material that offers the advantage of being well understood scientifically and more easily adopted by industry. Our technology is fundamentally the same as is already being used in countless everyday electronic devices, and that's a trillion-dollar industry."

The team's next goal is to combine pairs of quantum bits to create a two-qubit logic gate -- the basic processing unit of a quantum computer.

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Journal Reference:

1. Jarryd J. Pla, Kuan Y. Tan, Juan P. Dehollain, Wee H. Lim, John J. L. Morton, David N. Jamieson, Andrew S. Dzurak, Andrea Morello. A single-atom electron spin qubit in silicon. Nature, 2012; DOI: 10.1038/nature11449

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20 Sep, 2012

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Thermoelectric material is the best at converting heat waste to electricity

ScienceDaily (Sep. 19, 2012) — Northwestern University scientists have developed a thermoelectric material that is the best in the world at converting waste heat to electricity. This is very good news once you realize nearly two-thirds of energy input is lost as waste heat.

The material could signify a paradigm shift. The inefficiency of current thermoelectric materials has limited their commercial use. Now, with a very environmentally stable material that is expected to convert 15 to 20 percent of waste heat to useful electricity, thermoelectrics could see more widespread adoption by industry.

Possible areas of application include the automobile industry (much of gasoline's potential energy goes out a vehicle's tailpipe), heavy manufacturing industries (such as glass and brick making, refineries, coal- and gas-fired power plants) and places were large combustion engines operate continuously (such as in large ships and tankers).

Waste heat temperatures in these areas can range from 400 to 600 degrees Celsius (750 to 1,100 degrees Fahrenheit), the sweet spot for thermoelectrics use.

The new material, based on the common semiconductor lead telluride, is the most efficient thermoelectric material known. It exhibits a thermoelectric figure of merit (so-called "ZT") of 2.2, the highest reported to date. Chemists, physicists, material scientists and mechanical engineers at Northwestern and Michigan State University collaborated to develop the material.

The study will be published Sept. 20 by the journal Nature.

"Our system is the top-performing thermoelectric system at any temperature," said Mercouri G. Kanatzidis, who led the research and is a senior author of the paper. "The material can convert heat to electricity at the highest possible efficiency. At this level, there are realistic prospects for recovering high-temperature waste heat and turning it into useful energy."

Kanatzidis is Charles E. and Emma H. Morrison Professor of Chemistry in Northwestern's Weinberg College of Arts and Sciences. He also holds a joint appointment at Argonne National Laboratory.

"People often ask, what is the energy solution?" said Vinayak P. Dravid, one of Kanatzidis' close collaborators. "But there is no unique solution -- it's going to be a distributed solution. Thermoelectrics is not the answer to all our energy problems, but it is an important part of the equation."

Dravid is the Abraham Harris Professor of Materials Science and Engineering at the McCormick School of Engineering and Applied Science and a senior author of the paper.

Other members of the team and authors of the Nature paper include Kanishka Biswas, a postdoctoral fellow in Kanatzidis' group; Jiaqing He, a postdoctoral member in Dravid's group; David N. Seidman, Walter P. Murphy Professor of Materials Science and Engineering at Northwestern; and Timothy P. Hogan, professor of electrical and computer engineering, at Michigan State University.

Even before the Northwestern record-setting material, thermoelectric materials were starting to get better and being tested in more applications. The Mars rover Curiosity is powered by lead telluride thermoelectrics (although it's system has a ZT of only 1, making it half as efficient as Northwestern's system), and BMW is testing thermoelectrics in its cars by harvesting heat from the exhaust system.

"Now, having a material with a ZT greater than two, we are allowed to really think big, to think outside the box," Dravid said. "This is an intellectual breakthrough."

"Improving the ZT never stops -- the higher the ZT, the better," Kanatzidis said. "We would like to design even better materials and reach 2.5 or 3. We continue to have new ideas and are working to better understand the material we have."

The efficiency of waste heat conversion in thermoelectrics is governed by its figure of merit, or ZT. This number represents a ratio of electrical conductivity and thermoelectric power in the numerator (which need to be high) and thermal conductivity in the denominator (which needs to be low).

"It is hard to increase one without compromising the other," Dravid said. These contradictory requirements stalled the progress towards a higher ZT for many years, where it was stagnant at a nominal value of 1.

Kanatzidis and Dravid have pushed the ZT higher and higher in recent years by introducing nanostructures in bulk thermoelectrics. In January 2011, they published a report in Nature Chemistry of a thermoelectric material with a ZT of 1.7 at 800 degrees Kelvin. This was the first example of using nanostructures (nanocrystals of rock-salt structured strontium telluride) in lead telluride to reduce electron scattering and increase the energy conversion efficiency of the material.

The performance of the new material reported now in Nature is nearly 30 percent more efficient than its predecessor. The researchers achieved this by scattering a wider spectrum of phonons, across all wavelengths, which is important in reducing thermal conductivity.

"Every time a phonon is scattered the thermal conductivity gets lower, which is what we want for increased efficiency," Kanatzidis said.

A phonon is a quantum of vibrational energy, and each has a different wavelength. When heat flows through a material, a spectrum of phonons needs to be scattered at different wavelengths (short, intermediate and long).

In this work, the researchers show that all length scales can be optimized for maximum phonon scattering with minor change in electrical conductivity. "We combined three techniques to scatter short, medium and long wavelengths all together in one material, and they all work simultaneously," Kanatzidis said. "We are the first to scatter all three at once and at the widest spectrum known. We call this a panoscopic approach that goes beyond nanostructuring."

"It's a very elegant design," Dravid said.

In particular, the researchers improved the long-wavelength scattering of phonons by controlling and tailoring the mesoscale architecture of the nanostructured thermoelectric materials. This resulted in the world record of a ZT of 2.2.

The successful approach of integrated all-length-scale scattering of phonons is applicable to all bulk thermoelectric materials, the researchers said.

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The above story is reprinted from materials provided by Northwestern University, via EurekAlert!, a service of AAAS.

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Journal Reference:

1. Kanishka Biswas, Jiaqing He, Ivan D. Blum, Chun-I Wu, Timothy P. Hogan, David N. Seidman, Vinayak P. Dravid, Mercouri G. Kanatzidis. High-performance bulk thermoelectrics with all-scale hierarchical architectures. Nature, 2012; 489 (7416): 414 DOI: 10.1038/nature11439

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20 Sep, 2012

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Medication effective in treating social withdrawal in Fragile X and potentially autism patients

ScienceDaily (Sep. 19, 2012) — An investigational compound that targets the core symptoms of fragile X syndrome is effective for addressing the social withdrawal and challenging behaviors characteristic of the condition, making it the first such discovery for fragile X syndrome and, potentially, the first for autism spectrum disorder, a study by researchers at Rush University Medical Center and the University of California, Davis MIND Institute has found.

The finding is the result of a clinical trial in adult and pediatric subjects with fragile X syndrome. It suggests, however, that the compound may have treatment implications for at least a portion of the growing population of individuals with autism spectrum disorder, as well as for those with other conditions defined by social deficits. The study is published online September 19 in the journal Science Translational Medicine.

"There are no FDA-approved treatments for fragile X syndrome, and the available options help secondary symptoms but do not effectively address the core impairments in fragile X syndrome," said Dr. Elizabeth Berry-Kravis, the lead author of the article. "This is the first large-scale study that is based on the molecular understanding of fragile X syndrome and, importantly, suggests that the core symptoms may be amenable to pharmacologic treatment." Berry-Kravis is professor of Pediatrics, Neurological Sciences, and Biochemistry at Rush.

The "first-in-patient" drug trial was led by Berry-Kravis and Dr. Randi Hagerman of the UC Davis MIND Institute. It examined the effects of the compound STX 209, also known by the name Arbaclofen. The study was conducted collaboratively with Seaside Theraputics, a Cambridge, Mass., pharmaceutical company, that is focused on translating bench research on fragile X and autism into therapeutic interventions. Seaside Therapeutics produces the compound.

"This study shows that STX 209 is an important part of the treatment for fragile X syndrome, because it improved symptoms in those with significant social deficits or autism as well as fragile X syndrome," said Hagerman, who is the medical director of the MIND Institute. "Additional studies also are suggesting that STX 209 can be helpful for autism without fragile X syndrome. Until now, there have been no targeted treatments available for autism. This appears to be the first."

Fragile X syndrome is the most common known cause of inherited intellectual impairment, formerly referred to as mental retardation, and the leading known single-gene cause of autism. Social impairment is one of the core deficits in both fragile X and autism. The U.S. Centers for Disease Control and Prevention (CDC) estimates that about 1 in 4,000 males and 1 in 6,000 to 8,000 females have the disorder. An estimated 1 in 88 children born today will be diagnosed with autism, according to the CDC.

"This study will help to signal the beginning of a new era of targeted treatments for genetic disorders that have historically been regarded as beyond the reach of pharmacotherapy," Berry-Kravis said. "It will be a model for treatment of autism, intellectual disability and developmental brain disorders based on understanding of dysfunction in brain pathways, as opposed to empiric treatment of symptoms. We hope mechanistically-based treatments like STX209 ultimately will be shown to improve cognitive functioning in longer-term trials."

Studies in mice genetically engineered to exhibit features of fragile X, including social impairment, have suggested that the behavioral abnormalities in fragile X result from deficiencies in the neurotransmitter gamma-amino butyric acid (GABA). Decreased GABA has been observed in a mouse model of fragile X in many areas of the brain including the hippocampus, and has been hypothesized to be a basis of the social anxiety and avoidance characteristic of fragile X sufferers, the study says.

Arbaclofen is an agonist for gamma-amino butyric acid type B, or GABA-B, receptors. An agonist is a chemical that effectively combines with a receptor on a synapse to effect a physiologic reaction typical of a naturally occurring substance. Anxiety-driven repetitive behavior and social avoidance have been reduced in fragile X-engineered mice treated with arbaclofen. The current, first-of-its-kind study investigated whether Arbaclofen would produce similar results in human subjects.

The double-blind, placebo-controlled clinical trial initially recruited 63 subjects at 12 sites across the United States for the research, conducted between December 2008 and March 2010. The participants ranged in age from 6 to 39 years. Of the initial participants, 56 completed the clinical trial. There were no withdrawals related to drug tolerability. The majority of the subjects were treated with what was assessed as the optimum tolerated dosage of the study drug, 10 milligrams twice a day in younger patients and three times a day in adults. Compliance was monitored by patient guardians, who filled out a dosing form on a daily basis.

The study subjects returned for evaluations at two- and four-week intervals after beginning the six-week-long treatment. The drug then was tapered down over a one- to two-week period. After a week, the subjects entered a second treatment period.

The effects of the medication were scored on variables of the Aberrant Behavior Checklist, a behavior-rating scale for the assessment of drug-treatment effects. The checklist includes variables for irritability, lethargy/withdrawal, stereotypic (repetitive) behavior and hyperactivity, among other factors.

The study found improvement for the full study population on the social-avoidance subscale, an analysis validated by secondary ratings from parent observation of improvement in subjects' three most problematic behaviors. It found that the medication was the same as placebo, however, on the subscale for irritability.

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The above story is reprinted from materials provided by Rush University Medical Center, via EurekAlert!, a service of AAAS.

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Journal Reference:

1. E. M. Berry-Kravis, D. Hessl, B. Rathmell, P. Zarevics, M. Cherubini, K. Walton-Bowen, Y. Mu, D. V. Nguyen, J. Gonzalez-Heydrich, P. P. Wang, R. L. Carpenter, M. F. Bear, R. J. Hagerman. Effects of STX209 (Arbaclofen) on Neurobehavioral Function in Children and Adults with Fragile X Syndrome: A Randomized, Controlled, Phase 2 Trial. Science Translational Medicine, 2012; 4 (152): 152ra127 DOI: 10.1126/scitranslmed.3004214

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Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

20 Sep, 2012

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Using a laser to 'see' the smallest world: Powerful laser breathes new life into an old technology for studying atomic-level structures

ScienceDaily (Sep. 19, 2012) — A multi-university team has employed a high-powered laser based at UC Santa Barbara to dramatically improve one of the tools scientists use to study the world at the atomic level. The team used their amped-up electron paramagnetic resonance (EPR) spectrometer to study the electron spin of free radicals and nitrogen atoms trapped inside a diamond.

The improvement will pull back the veil that shrouds the molecular world, allowing scientists to study tiny molecules at a high resolution.

The team, which includes researchers from UCSB, University of Southern California (USC), and Florida State University, published its findings this week in Nature.

"We developed the world's first free-electron laser-powered EPR spectrometer," said Susumu Takahashi, assistant professor of chemistry at the USC Dornsife College of Letters, Arts and Sciences, and lead author of the Nature paper. "This ultra high-frequency, high-power EPR system gives us extremely good time resolution. For example, it enables us to film biological molecules in motion."

By using a high-powered laser, the researchers were able to significantly enhance EPR spectroscopy, which uses electromagnetic radiation and magnetic fields to excite electrons. These excited electrons emit electromagnetic radiation that reveals details about the structure of the targeted molecules.

EPR spectroscopy has existed for decades. Its limiting factor is the electromagnetic radiation source used to excite the electrons -- it becomes more powerful at high magnetic fields and frequencies, and, when targeted, electrons are excited with pulses of power as opposed to continuous waves.

Until now, scientists performed pulsed EPR spectroscopy with a few tens of GHz of electromagnetic radiation. Using UCSB's free electron laser (FEL), which emits a pulsed beam of electromagnetic radiation, the team was able to use 240 GHz of electromagnetic radiation to power an EPR spectrometer.

"Each electron can be thought of as a tiny magnet that senses the magnetic fields caused by atoms in its nano-neighborhood," said Mark Sherwin, professor of physics and director of the Institute for Terahertz Science and Technology at UCSB. "With FEL-powered EPR, we have shattered the electromagnetic bottleneck that EPR has faced, enabling electrons to report on faster motions occurring over longer distances than ever before. We look forward to breakthrough science that will lay foundations for discoveries like new drugs and more efficient plastic solar cells."

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Journal Reference:

1. S. Takahashi, L.-C. Brunel, D. T. Edwards, J. van Tol, G. Ramian, S. Han, M. S. Sherwin. Pulsed electron paramagnetic resonance spectroscopy powered by a free-electron laser. Nature, 2012; 489 (7416): 409 DOI: 10.1038/nature11437

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20 Sep, 2012

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Experiment corrects prediction in quantum theory

ScienceDaily (Sep. 19, 2012) — An international team of scientists is rewriting a page from the quantum physics rulebook using a University of Florida laboratory once dubbed the coldest spot in the universe.

Much of what we know about quantum mechanics is theoretical and tested via computer modeling because quantum systems, like electrons whizzing around the nucleus of an atom, are difficult to pin down for observation. One can, however, slow particles down and catch them in the quantum act by subjecting them to extremely cold temperatures. New research, published in the Sept. 20 edition of the journal Nature, describes how this freeze-frame approach was recently used to overturn an accepted rule of thumb in quantum theory.

"We are in the age of quantum mechanics," said Neil Sullivan, a UF physics professor and director of the National High Magnetic Field Laboratory High B/T Facility on the UF campus -- home of the Microkelvin lab where experiments can be conducted in near-absolute zero temperatures. "If you've had an MRI, you have made use of a quantum technology."

The magnet that powers an MRI scanner is a superconducting coil transformed into a quantum state by very cold liquid helium. Inside the coil, electric current flows friction free.

Quantum magnets and other strange, almost otherworldly occurrences in quantum mechanics could inspire the next big breakthroughs in computing, alternative energy and transportation technologies such as magnetic levitating trains, Sullivan said. But innovation cannot proceed without a proper set of guidelines to help engineers navigate the quantum road.

That's where the Microkelvin lab comes in. It is one of the few facilities in the world equipped to deliver the extremely cold temperatures needed to slow what Sullivan calls the "higgledy-piggledy" world of quantum systems at normal temperatures to a manageable pace where it can be observed and manipulated.

"Room temperature is approximately 300 kelvin," Sullivan said. "Liquid hydrogen pumped into a rocket at the Kennedy Space Center is at 20 kelvin."

Physicists need to cool things down to 1 millikelvin, one thousandth of a kelvin above absolute zero, or -459.67 degrees Fahrenheit, to bring matter into a different realm where quantum properties can be explored.

One fundamental state of quantum mechanics that scientists are keen to understand more fully is a fragile, ephemeral phase of matter called a Bose-Einstein Condensate. In this state, individual particles that make up a material begin to act as a single coherent unit. It's a tricky condition to induce in a laboratory setting, but one that researchers need to explore if technology is ever to fully exploit the properties of the quantum world.

Two theorists, Tommaso Roscilde at the University of Lyon, France, and Rong Yu from Rice University in Houston, developed the underlying ideas for the study and asked a colleague, Armando Paduan-Filho from the University of Sao Paulo in Brazil, to engineer the crystalline sample used in the experiment.

"Our measurements definitively tested an important prediction about a particular behavior in a Bose-Einstein Condensate," said Vivien Zapf, a staff scientist at the National High Magnetic Field Laboratory at Los Alamos and a driving force behind the international collaboration.

The experiment monitored the atomic spin of subatomic particles called bosons in the crystal to see when the transition to Bose-Einstein Condensate was achieved, and then further cooled the sample to document the exact point where the condensate properties decayed. They observed the anticipated phenomenon when they took the sample down to 1 millikelvin.

The crystal used in the experiment had been doped with impurities in an effort to create more of a real world scenario, Zapf said. "It's nice to know what happens in pure samples, but the real world, is messy and we need to know what the quantum rules are in those situations."

Having performed a series of simulations in advance, they knew that the experiment would require them to generate temperatures down to 1 millikelvin.

"You have to go to the Microkelvin Laboratory at UF for that," she said. The lab is housed within the National High Magnetic Field Laboratory High B/T Facility at UF, funded by the National Science Foundation. Other laboratories can get to the extreme temperature required, but none of them can sustain it long enough to collect all of the data needed for the experiment.

"It took six months to get the readings," said Liang Yin, an assistant scientist in the UF physics department who operated the equipment in the Microkelvin lab. "Because the magnetic field we used to control the wave intensity in the sample also heats it up. You have to adjust it very slowly."

Their findings literally rewrote the rule for predicting the conditions under which the transition would occur between the two quantum states.

"All the world should be watching what happens as we uncover properties of systems at these extremely low temperatures," Sullivan said. "A superconducting wire is superconducting because of this Bose-Einstein Condensation concept. If we are ever to capitalize on it for quantum computing or magnetic levitation for trains, we have to thoroughly understand it."

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Story Source:

The above story is reprinted from materials provided by University of Florida. The original article was written by Donna Hesterman.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

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Journal Reference:

1. Rong Yu, Liang Yin, Neil S. Sullivan, J. S. Xia, Chao Huan, Armando Paduan-Filho, Nei F. Oliveira Jr, Stephan Haas, Alexander Steppke, Corneliu F. Miclea, Franziska Weickert, Roman Movshovich, Eun-Deok Mun, Brian L. Scott, Vivien S. Zapf, Tommaso Roscilde. Bose glass and Mott glass of quasiparticles in a doped quantum magnet. Nature, 2012; 489 (7416): 379 DOI: 10.1038/nature11406

Note: If no author is given, the source is cited instead.

Disclaimer: Views expressed in this article do not necessarily reflect those of ScienceDaily or its staff.

20 Sep, 2012

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Source: http://feeds.sciencedaily.com/~r/sciencedaily/top_news/top_science/~3/bu70f71_i3M/120919135312.htm
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Human brains share a consistent genetic blueprint and possess enormous biochemical complexity

ScienceDaily (Sep. 19, 2012) — Scientists at the Allen Institute for Brain Science reported in the latest issue of the journal Nature that human brains share a consistent genetic blueprint and possess enormous biochemical complexity. The findings stem from the first deep and large-scale analysis of the vast data set publicly available in the Allen Human Brain Atlas.

The results of this study are based on extensive analysis of the Allen Human Brain Atlas, specifically the detailed all-genes, all-structures survey of genes at work throughout the human brain. This dataset profiles 400 to 500 distinct brain areas per hemisphere using microarray technology and comprises more than 100 million gene expression measurements covering three individual human brains to date. Among other findings, these data show that 84% of all genes are expressed somewhere in the human brain and in patterns that are substantially similar from one brain to the next.

"This study demonstrates the value of a global analysis of gene expression throughout the entire brain and has implications for understanding brain function, development, evolution and disease," said Ed Lein, Ph.D., Associate Investigator at the Allen Institute for Brain Science and co-lead author on the paper. "These results only scratch the surface of what can be learned from this immense data set. We look forward to seeing what others will discover."

Key Findings

The results of this study show that, despite the myriad personalities and cognitive talents seen across the human population, our brains are more similar to one another than different. Individual human brains share the same basic molecular blueprint, and deeper analysis of this shared architecture reveals several further findings:

• Neighboring regions of the brain's cortex -- the wrinkly outer rind -- are more biochemically similar to one another than to more distant brain regions, which has implications for understanding the development of the human brain, both during the lifespan and throughout evolution.
• The right and left hemispheres show no significant differences in molecular architecture. This suggests that functions such as language, which are generally handled by one side of the brain, likely result from more subtle differences between hemispheres or structural variation in size or circuitry, but not from a deeper molecular basis.
• Despite controlling a diversity of functions, ranging from visual perception to planning and problem-solving, the cortex is highly homogeneous relative to other brain regions. This suggests that the same basic functional elements are used throughout the cortex and that understanding how one area works in detail will uncover fundamentals that apply to the other areas, as well.

In addition to such global findings, the study provides new insights into the detailed inner workings of the brain at the molecular level -- the level at which diseases unfold and therapeutic drugs take action.

• 84% of all genes are expressed, or turned on, somewhere in the human brain.
• Many previously uncharacterized genes are turned on in specific brain regions and localize with known functional groups of genes, suggesting they play roles in particular brain functions.
• Synapse-associated genes -- those related to cell-to-cell communication machinery in the brain -- are deployed in complex combinations throughout the brain, revealing a great diversity of synapse types and remarkable regional variation that likely underlies functional distinctions between brain regions.

"The tremendous variety of synapses we see in the human brain is quite striking," said Seth Grant, FRSE, Professor of Molecular Neuroscience at the University of Edinburgh and collaborating author on the study. "Mutations in synaptic genes are associated with numerous brain-related disorders, and thus understanding synapse diversity and organization in the brain is a key step toward understanding these diseases and developing specific and effective therapeutics to treat them."

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The above story is reprinted from materials provided by Allen Institute for Brain Science.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

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Journal Reference:

1. Michael J. Hawrylycz, Ed S. Lein, Angela L. Guillozet-Bongaarts, Elaine H. Shen, Lydia Ng, Jeremy A. Miller, Louie N. van de Lagemaat, Kimberly A. Smith, Amanda Ebbert, Zackery L. Riley, Chris Abajian, Christian F. Beckmann, Amy Bernard, Darren Bertagnolli, Andrew F. Boe, Preston M. Cartagena, M. Mallar Chakravarty, Mike Chapin, Jimmy Chong, Rachel A. Dalley, Barry David Daly, Chinh Dang, Suvro Datta, Nick Dee, Tim A. Dolbeare, Vance Faber, David Feng, David R. Fowler, Jeff Goldy, Benjamin W. Gregor, Zeb Haradon, David R. Haynor, John G. Hohmann, Steve Horvath, Robert E. Howard, Andreas Jeromin, Jayson M. Jochim, Marty Kinnunen, Christopher Lau, Evan T. Lazarz, Changkyu Lee, Tracy A. Lemon, Ling Li, Yang Li, John A. Morris, Caroline C. Overly, Patrick D. Parker, Sheana E. Parry, Melissa Reding, Joshua J. Royall, Jay Schulkin, Pedro Adolfo Sequeira, Clifford R. Slaughterbeck, Simon C. Smith, Andy J. Sodt, Susan M. Sunkin, Beryl E. Swanson, Marquis P. Vawter, Derric Williams, Paul Wohnoutka, H. Ronald Zielke, Daniel H. Geschwind, Patrick R. Hof, Stephen M. Smith, Christof Koch, Seth G. N. Grant, Allan R. Jones. An anatomically comprehensive atlas of the adult human brain transcriptome. Nature, 2012; 489 (7416): 391 DOI: 10.1038/nature11405

Note: If no author is given, the source is cited instead.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

20 Sep, 2012

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Source: http://feeds.sciencedaily.com/~r/sciencedaily/top_news/top_science/~3/K9srO9CJZWo/120919135318.htm
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The more people rely on their intuitions, the more cooperative they become

ScienceDaily (Sep. 19, 2012) — It's an age old question: Why do we do good? What makes people sometimes willing to put "We" ahead of "Me?" Perhaps our first impulse is to be selfish, and cooperation is all about reining in greed. Or maybe cooperation happens spontaneously, and too much thinking gets in the way.

Harvard scientists are getting closer to an answer, showing that people's first response is to cooperate and that stopping to think encourages selfishness.

David Rand, a Post-Doctoral Fellow in Psychology, Joshua Greene, the John and Ruth Hazel Associate Professor of the Social Sciences in the Department of Psychology, and Martin Nowak, Professor of Mathematics and of Biology, and Director of the Program for Evolutionary Dynamics, have published their findings in the September 20 issue of Nature. They recruited thousands of participants to play a "public goods game" in which it's "Me" vs. "Us." Subjects were put into small groups and faced with a choice: Keep the money you've been given, or contribute it into a common pool that grows and benefits the whole group. Hold onto the money and you come out ahead, but the group does best when everyone contributes.

The researchers wanted to know whether people's first impulse is cooperative or selfish. To find out, they started by looking at how quickly different people made their choices, and found that faster deciders were more likely to contribute to the common good.

Next they forced people to go fast or to stop and think, and found the same thing: Faster deciders tended to be more cooperative, and the people who had to stop and think gave less.

Finally, the researchers tested their hypothesis by manipulating people's mindsets. They asked some people to think about the benefits of intuition before choosing how much to contribute. Others were asked to think about the virtues of careful reasoning. Once again, intuition promoted cooperation, and deliberation did the opposite.

While some might interpret the results as suggesting that cooperation is "innate" or "hard-wired," if anything they highlight the role of experience. People who had better opinions of those around them in everyday life showed more cooperative impulses in these experiments, and previous experience with these kinds of studies eroded those impulses.

"In daily life, it's generally in your interest to be cooperative," Rand said. "So we internalize cooperation as the right way to behave. Then when we come into unusual environments, where incentives like reputation and sanctions are removed, our first response is to keep behaving the way we do in normal life. When we think about it, however, we realize that this is one of those rare situations where we can be selfish and get away with it."

Unlike many psychology studies, which use small numbers of college students, these experiments tested thousands of people from around the world using Amazon Mechanical Turk, an online labor market that's becoming an increasingly popular tool for social science research.

According to Rand, the findings highlight an interesting and counterintuitive truth -- that careful thought and reflection have a dark side. But is reflection always bad?

"When it's 'Me' vs. 'Us,' our intuitions seem to work well. That's what's going on here," explains Joshua Greene. "But what happens when people have different moral intuitions, for example, about abortion or raising taxes? When intuitions clash -- when it's the values of 'Us' vs. 'Them' -- reasoning and reflection may be our best hope for reconciling our differences."

"Over millions of years we've evolved the capacity for cooperation," explains Martin Nowak. "These psychological experiments examine the causes of cooperation on a shorter timescale, on the order of seconds. Both perspectives are essential as we face global problems which require cooperation on a massive scale. We need to understand where cooperation comes from historically and how best to make it happen here and now."

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The above story is reprinted from materials provided by Harvard University, via EurekAlert!, a service of AAAS.

Note: Materials may be edited for content and length. For further information, please contact the source cited above.

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Journal Reference:

1. David G. Rand, Joshua D. Greene, Martin A. Nowak. Spontaneous giving and calculated greed. Nature, 2012; 489 (7416): 427 DOI: 10.1038/nature11467

Note: If no author is given, the source is cited instead.

Disclaimer: This article is not intended to provide medical advice, diagnosis or treatment. Views expressed here do not necessarily reflect those of ScienceDaily or its staff.

20 Sep, 2012

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Source: http://feeds.sciencedaily.com/~r/sciencedaily/top_news/top_science/~3/sQyIezy4Wss/120919142144.htm
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