Climate will damage reefs at 'different rates'

Climate will damage reefs at 'different rates'

  7:15:00 PM    Science Lover

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Climate change and acidifying ocean water are likely to have a highly variable impact on the world's coral reefs in space, time and diversity, according to an international team of coral scientists, including UQ researchers.

Reefs are naturally highly diverse and resilient

The picture that is emerging from studies of past coral extinctions and present impacts on today's reef systems is complex and subtle.

It will demand much more sophisticated management to preserve reefs intact, the team of scientists said in a paper in the international journal Science.

“New research confirms that coral reefs…. are indeed threatened by climate change, but that some current projections of global-scale collapse of reefs within the next few decades probably overestimate the rapidity and uniformity of the decline,” the researchers said.

“A considered view of all the most recent evidence suggests that some coral reef systems will decline more rapidly – especially those subject to other human pressures such as overfishing," said lead author Professor John Pandolfi of the ARC Centre of Excellence for Coral Reef Studies and The University of Queensland..

"However, others may change in composition, but manage to persist for longer.”

The paper, “Projecting coral reef futures under global warming and ocean acidification” by John M. Pandolfi, Sean R. Connolly, Dustin J. Marshall and Anne L. Cohen appears in the latest issue of the journal Science.

“Coral reefs occupy a small part of the world's oceans, yet harbor a hugely disproportionate amount of its biodiversity,” the researchers said.

“More than 450 million people from 109 countries live close to coral reefs, which provide important sources of ecosystem goods and services for these communities.

“But reefs have suffered degradation from human over-exploitation and pollution over centuries to millennia, degradation that has accelerated in the last 50 years.

"Global warming and ocean acidification are now compounding these threats.”

However reefs are naturally highly diverse and resilient, and are likely to respond to the changed conditions in different ways and at varying rates.

The research paper says that past extinction crises in coral reef ecosystems appeared to coincide with episodes of rapid global warming and ocean acidification.

"This has led some to predict rapid, dramatic, global-scale losses of coral reefs.

“Widespread degradation of reefs is already underway," said another of the study authors, Professor Sean Connolly of the ARC Center of Excellence for Coral Reef Studies and James Cook University.

"However, rates of future decline will be highly variable, because coral reefs are naturally highly diverse with some species able to cope with change more than others.

Moreover, changes in ocean and climate conditions will be different in different regions, and the partnership between corals and their symbiotic algae has variable capacity to adapt to changing conditions.”

The researchers said that evolution and genetic change in both creatures could make them more tolerant of major changes in ocean temperature and chemistry – but, paradoxically, it could also accelerate the decline of reef species.

However, human management was necessary to improve the corals' chances.

Actions that improved coral diversity would tend to make reefs more resilient.

The researchers also noted that large populations of reef species, not already stressed by overfishing or coastal runoff, were likely to be better able to adapt to the challenges of climate change.



“This makes the overall picture extraordinarily complex," Professor Pandolfi said.

"We do not yet have a model that explains the full spectrum of reef responses everywhere."

The researchers highlighted some critical knowledge gaps, including the effects of climate change on interactions between species, and the potential rates of adaptation of reef species to warmer and more acidic conditions.

“Our ability to continue to improve our projections of climate change effects on coral reefs depends especially on advances in our understanding of these areas,” Professor Connolly said.

“We think it would be best if the world prepares itself for a range of possible impacts and responses on reefs, and manages them accordingly, if we are to give our corals their best possible chance of survival through what we know from geological history is bound to be a very stressful era of environmental change.”

The researchers said that the best and most achievable thing people could do for coral reefs to deal with climate change was to seek to manage them well.

“However, slowing rates of climate change, and reducing the strong selection imposed by human impacts such as fishing and coastal development will remain critical to the long-term persistence of coral reef ecosystems,” they said.

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Memories May Skew Visual Perception

Memories May Skew Visual Perception

  6:46:00 PM    Science Lover

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Taking a trip down memory lane while you are driving could land you in a roadside ditch, new research indicates. Vanderbilt University psychologists have found that our visual perception can be contaminated by memories of what we have recently seen, impairing our ability to properly understand and act on what we are currently seeing.

aking a trip down memory lane while you are driving could 
land you in a roadside ditch, new research indicates. 
(Credit: © yellowj / Fotolia)

"This study shows that holding the memory of a visual event in our mind for a short period of time can 'contaminate' visual perception during the time that we're remembering," Randolph Blake, study co-author and Centennial Professor of Psychology, said.

"Our study represents the first conclusive evidence for such contamination, and the results strongly suggest that remembering and perceiving engage at least some of the same brain areas."

The study, led by research associate Min-Suk Kang, was recently published in the journal Psychonomic Bulletin & Review.

"There are numerous instances where we engage in visually guided activities, such as driving, while rehashing visual events in our mind's eye. Common sense tells us that this mental replay is harmless in that it does not interfere with our ability to register and react to objects within our visual field," Kang and his co-authors wrote. "Evidently, however, that is not always true when the contents of our working memories overlap with the contents of our perceptual world."

Illusion offers clues

In this study, the researchers used a visual illusion called motion repulsion to learn whether information held in working memory affects perception. This illusion is produced when two sets of moving dots are superimposed, with dots in one set moving in a different direction from those in the other set. Under these conditions, people tend to misperceive the actual directions of motion, and perceive a larger difference between the two sets of motions than actually exists.



Ordinarily this illusion is produced by having people view both sets of motion at the same time. Kang and colleagues set out to determine if the illusion would occur when one set of motions, rather than being physically present, was held in working memory.

In the experiment, participants were shown a random pattern of dots and were asked to remember the direction in which the dots were moving. They were then were shown a second pattern of moving dots. They were asked to report on the direction of second dots' movement.

The research subjects' reports of the second dots' movement was exaggerated and influenced by what they had previously seen. If they were first shown dots moving in one direction and later shown dots moving in a slightly counterclockwise direction relative to the first presented dots, they reported the counterclockwise movement to be more dramatic than it had actually been.

"We find that observers misperceive the actual direction of motion of a single motion stimulus if, while viewing that stimulus, they are holding a different motion direction in visual working memory," the authors wrote.

The results provide further support for previous findings by Vanderbilt researchers Frank Tong and Stephanie Harrison that the contents of working memory may be represented in early visual areas in the brain, including the primary visual cortex, that were previously thought to play no role in higher cognitive functions such as memory.

"Our findings provide compelling evidence that visual working memory representations directly interact with the same neural mechanisms involved in processing basic sensory events," Kang and his colleagues wrote.

Kang and Blake's co-authors were research associate Sang Wook Hong and Assistant Professor of Psychology Geoffrey Woodman. Funding from the National Institutes of Health, the National Science Foundation and the World Class University Initiative of the National Research Foundation of Korea and the Ministry of Education, Science and Technology supported the research.

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Breakthrough in Quantum Computing: Researchers Develop System That Resists 'Quantum Bug'

Breakthrough in Quantum Computing: Researchers Develop System That Resists 'Quantum Bug'

  10:36:00 PM    Science Lover

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Scientists have taken the next major step toward quantum computing, which will use quantum mechanics to revolutionize the way information is processed.

Quantum computing uses quantum bits, or qubits, to 
encode information. (Credit: © Anterovium / Fotolia)

Quantum computers will capitalize on the mind-bending properties of quantum particles to perform complex calculations that are impossible for today's traditional computers.

Using high magnetic fields, Susumu Takahashi, assistant professor in the USC Dornsife College of Letters, Arts and Sciences, and his colleagues managed to suppress decoherence, which is one of the key stumbling blocks in quantum computing.

"High magnetic fields reduce the level of the noises in the surroundings, so they can constrain the decoherence very efficiently," Takahashi said. Decoherence has been described as a "quantum bug" that destroys fundamental properties that quantum computers would rely on.

This research will appear in the online version of Nature magazine on June 20.

Quantum computing uses quantum bits, or qubits, to encode information in the form of ones and zeros. Unlike a traditional computer that uses traditional bits, a quantum computer takes advantage of the fact seemingly impossible fact that qubits can exist in multiple states at the same time, which is called "superposition."

While can a bit can represent either a one or a zero, a qubit can represent a one and a zero at the same time due to superposition. This allows for simultaneous processing of calculations in a truly parallel system, skyrocketing computing ability.

Though the concepts underpinning quantum computing are not new, problems such as decoherence have hindered the construction of a fully functioning quantum computer.

Think of decoherence as a form of noise or interference, knocking a quantum particle out of superposition -- robbing it of that special property that makes it so useful. If a quantum computer relies on a quantum particle's ability to be both here and there, then decoherence is the frustrating phenomenon that causes a quantum particle to be either here or there.

The researchers calculated all sources of decoherence in his experiment as a function of temperature, magnetic field, and by nuclear isotopic concentrations, and suggested the optimum condition to operate qubits, reducing decoherence by approximately 1,000 times.

Qubits in his experiment lasted about 500 microseconds at the optimum condition -- ages, relatively speaking.

Decoherence in qubit systems falls into two general categories. One is an intrinsic decoherence caused by constituents in the qubit system, and the other is an extrinsic decoherence caused by imperfections of the system, for example, impurities and defects.

In their study, Takahashi and his colleagues investigated single crystals of molecular magnets. Because of their purity, molecular eliminate the extrinsic decoherence, allowing researchers to calculate intrinsic decoherence precisely.

"For the first time we've been able to predict and control all the environmental decoherence mechanisms in a very complex system -- in this case a large magnetic molecule," said Phil Stamp, UBC professor of physics and astronomy and director of the Pacific Institute of Theoretical Physics.

Using crystalline molecular magnets allowed researchers to build qubits out of multiple quantum particles, rather than a single quantum object -- the way most proto-quantum computers are built at the moment.

"This will obviously increase signals from the qubit drastically, so the detection of the qubit in the molecular magnets is much easier," Takahashi said.

Takahashi conducted his research as a project scientist in the Institute of Terahertz Science and Technology and Department of Physics at the University of California Santa Barbara and analyzed the data while at UCSB and USC. Takahashi has been in the USC Dornsife College since 2010.

Research for the article was performed in collaboration with Phil Stamp and Igor Tupitsyn of the University of British Columbia, Johan van Tol of Florida State University, and David Hendrickson of UC San Diego.

This work was supported by the National Science Foundation, the W. M. Keck Foundation, the Pacific Institute of Theoretical Physics at UBC, by the Natural Sciences and Engineering Research Council of Canada, the Canadian Institute for Advanced Research and the USC startup funds.

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Sperm coat protein may be key to male infertility

Sperm coat protein may be key to male infertility

  1:11:00 PM    Science Lover

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The loss of a protein that coats sperm may explain a significant proportion of infertility in men worldwide, according to a study by an international team of researchers led by UC Davis. The research could open up new ways to screen and treat couples for infertility. A paper describing the work is published July 20 in the journal Science Translational Medicine.

These are normal human sperm. Green dots show the presence of a sugary molecule that allows the sperm to swim through cervical mucus. Credit: Ted Tollner, UC Davis

The protein DEFB126 acts as a "Klingon cloaking device," allowing sperm to swim through mucus and avoid the immune system in order to reach the egg, said Gary Cherr, a professor at the UC Davis Bodega Marine Laboratory and Center for Health and Environment. Cherr is the senior author of the paper.

But the UC Davis researchers found that many men carry a defective gene for DEFB126. A survey of samples from the U.S., United Kingdom and China showed that as many as a quarter of men worldwide carry two copies of the defective gene – which may significantly affect their fertility.

Infertility affects 10 to 15 percent of the U.S. population, said John Gould, associate professor of urology at UC Davis, who was not involved in the research. About half of those cases involve problems with male fertility.One of the mysteries of human fertility is that sperm quality and quantity seem to have little do with whether or not a man is fertile, said Ted Tollner, first author of the paper, who carried out the work as a postdoctoral scholar with Cherr. Tollner is now an adjunct assistant professor in the UC Davis Department of Obstetrics and Gynecology.

"In 70 percent of men, you can't explain their infertility on the basis of sperm count and quality," Cherr said. Studies like this may give us opportunities to explain these cases, Gould said.

If the discovery were successfully developed into a test, it could be used to send couples directly to treatment with intracytoplasmic sperm injection or ICSI, in which eggs are removed from the woman and injected directly with sperm, avoiding an expensive workup to exclude other causes, Gould said.

Tollner and Cherr were looking for ways to make contraceptive vaccines when they started looking at DEFB126. The protein belongs to a class of molecules called defensins, natural germ-killers found on mucosal surfaces. DEFB126 is produced in the epididymis, the structure where sperm are stored after they are produced in the testes, and deposited onto sperm in the epididymis to form a thick coat.



Tollner and Cherr were trying to make antibodies to the human protein, without much success. So they enlisted the help of Professor Charles Bevins, an expert on defensins who had just joined the UC Davis Department of Medical Microbiology and Immunology.

Bevins' lab made a recombinant copy of the human DEFB126 gene, with the aim of generating a purified protein that Tollner and Cherr could use to create antibodies. On their first attempt, they found the gene had a mutation that prevented it from making a protein. But when they used sperm from a different donor, they were able to make the normal protein.

"If we hadn't seen this in the first clone, we would be confused to this day," Bevins said.

Sperm from men with the defective DEFB126 genes look normal under a microscope and swim around like normal sperm. But they are far less able to swim through an artificial gel made to resemble human cervical mucus.When the normal protein is added to the sperm, they recover their normal abilities, the team found.

Working with Edward Hollox at the University of Leicester, England, Xiping Xu at the University of Illinois, Chicago, and Scott Venners at Simon Fraser University, Canada, the researchers were able to look at the frequency of the gene in DNA samples from people in the U.S., United Kingdom, China, Japan and Africa.

They found that worldwide, about half of all men carry one defective copy; a quarter have two defective copies and therefore make sperm that are poor at swimming through mucus.

In collaboration with Xue Liu and other scientists at Anhui Medical University in Anhui, China, the epidemiology team headed by Venners was able to look at the effect of the mutation on a group of couples trying to conceive. They found a statistically significant decrease in the number of pregnancies in couples where the man carried two copies of the defective DEFB126 gene.

Why should a mutation that affects fertility be so astonishingly common? It may be that heterozygotes – men with one normal and one defective gene, but normal fertility – are advantaged in some way, Tollner said.

Tollner noted that compared to sperm from monkeys and other mammals, human sperm are typically poor quality, slow-swimming, and with a high rate of defective cells. It's possible that because humans, unlike most mammals, breed in long-term monogamous relationships, sperm quality just does not matter very much, Cherr said.

However, some researchers believe that, for reasons unknown, human male fertility has been falling worldwide in recent decades. That decline might be unmasking the problems associated with the defective DEFB126 gene.

Cherr said that they hope next to work with a major infertility program in the U.S. to further explore the role of the mutation.
Provided by University of California - Davis

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Bristol physicists break 150-year-old law

Bristol physicists break 150-year-old law

  9:55:00 AM    Science Lover

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A violation of one of the oldest empirical laws of physics has been observed by scientists at the University of Bristol. Their experiments on purple bronze, a metal with unique one-dimensional electronic properties, indicate that it breaks the Wiedemann-Franz Law. This historic discovery is described in a paper published today in Nature Communications.

Apparatus from the original 1853 paper in which the Wiedemann-Franz Law was first established

In 1853, two German physicists, Gustav Wiedemann and Rudolf Franz, studied the thermal conductivity (a measure of a system’s ability to transfer heat) of a number of elemental metals and found that the ratio of the thermal to electrical conductivities was approximately the same for different metals at the same temperature.

The origin of this empirical observation did not become clear however until the discovery of the electron and the advent of quantum physics in the early twentieth century. Electrons have a spin and a charge. When they move through a metal they cause an electrical current because of the moving charge. In addition, the moving electrons also carry heat through the metal but now it is via both the charge and the spin. So a moving electron must carry both heat and charge: that is why the ratio does not vary from metal to metal.

For the past 150-plus years, the Wiedemann-Franz law has proved to be remarkably robust, the ratio varying at most by around 50 per cent amongst the thousands of metallic systems studied.

In 1996, American physicists C. L. Kane and Matthew Fisher made a theoretical prediction that if you confine electrons to individual atomic chains, the Wiedemann-Franz law could be strongly violated. In this one-dimensional world, the electrons split into two distinct components or excitations, one carrying spin but not charge (the spinon), the other carrying charge but not spin (the holon). When the holon encounters an impurity in the chain of atoms it has no choice but for its motion to be reflected. The spinon, on the other hand, has the ability to tunnel through the impurity and then continue along the chain. This means that heat is conducted easily along the chain but charge is not. This gives rise to a violation of the Wiedemann-Franz law that grows with decreasing temperature.

The experimental group, led by Professor Nigel Hussey of the Correlated Electron Systems Group at the University of Bristol, tested this prediction on a purple bronze material comprising atomic chains along which the electrons prefer to travel.



Remarkably, the researchers found that the material conducted heat 100,000 times better than would have been expected if it had obeyed the Wiedemann-Franz law like other metals. Not only does this remarkable capability of this compound to conduct heat have potential from a technological perspective, such unprecedented violation of the Wiedemann-Franz law provides striking evidence for this unusual separation of the spin and charge of an electron in the one-dimensional world.

Professor Hussey said: “One can create purely one-dimensional atomic chains on substrates, or free-standing two-dimensional sheets, like graphene, but in a three-dimensional complex solid, there will always be some residual coupling between individual chains of atoms within the complex that allow the electrons to move in three-dimensional space.

“In this purple bronze, however, nature has conspired to limit this coupling to such an extent that the electrons are effectively confined to individual chains and thus creating a one-dimensional world inside the three-dimensional complex. The goal now is to find a way, for example, using pressure or chemical substitution, to increase the ability of the electrons to hop between adjacent chains and to study the evolution of the spin and charge states as the three-dimensional world is restored within the material.”

More information: ‘Gross violation of the Wiedemann-Franz law in a quasi-one-dimensional conductor’ by Nicholas Wakeham, et al. in Nature Communications

Provided by University of Bristol

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Physicists take steps toward delivering quantum information to the home

Physicists take steps toward delivering quantum information to the home

  10:36:00 AM    Science Lover

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Today, fiber optics technology transports information in the form of classical data to homes and businesses. But researchers are currently working on ways to combine quantum data with the classical data in fiber optics networks in order to increase security. In a new study, scientists have shown how quantum and classical data can be interlaced in a real-world fiber optics network, taking a step toward distributing quantum information to the home, and with it a quantum internet.

A tree network is often used to distribute classical data to homes via fiber optics. Researchers are working on co-propagating quantum information with the classical data to improve security. Image copyright: Iris Choi, et al. ©2011 IOP Publishing Ltd and Deutsche Physikalische Gesellschaft

The physicists, Iris Choi, Robert J. Young, and Paul D. Townsend, from the Tyndall National Institute at the University College Cork in Cork, Ireland, have published their study on combining quantum and classical signals in a recent issue of the New Journal of Physics. While the feasibility of transferring qubits on modern fiber-to-the-home (FTTH) networks has previously been demonstrated, this is the first time that researchers have investigated how the operation would work in a real-world network.

“I believe that our work constitutes the first really hard-nosed, pragmatic attempt to address the question of whether quantum key distribution (QKD) can work on a real fiber-to-the-home (FTTH) network,” Townsend told PhysOrg.com. “The new scheme that we have developed and tested demonstrates that the answer is ‘yes it can.’ I say pragmatic and hard-nosed because we have taken a widely deployed classical FTTH system and have adapted QKD to interwork with it, leaving the design of the classical part of the system essentially unchanged. The alternative approach, sometimes taken in QKD research, is to leave out the classical system completely or to adapt it to work with the QKD. In our view this is not very practical for cost reasons.”

The biggest challenge in transferring qubits in real-world networks is overcoming the crosstalk between the classical and quantum channels. Crosstalk is induced by spontaneous Raman scattering of photons in the optical fiber. Since the classical channels involve strong laser pulses while the quantum information is carried by single photons, the crosstalk primarily affects the quantum channel, making the error rate so high that the quantum channel is unable to operate.



Previous research has shown that the Raman noise level can be reduced by optical filtering, although this technique is too expensive for practical use. So Choi, Young, and Townsend have developed and demonstrated a novel noise suppression scheme that involves creating gaps in the scattering, and sending quantum data in these gaps.

First, the researchers chose a configuration that used two different wavelengths for transmitting the quantum and classical channels. In this configuration, only the Raman-scattered light in the “upstream” channel (going away from a user’s house) can generate crosstalk for that user. Then, the researchers identified quiet periods between the bursts of noise generated by Raman scattering in the upstream channel. Using a time and wavelength-multiplexing scheme, the researchers demonstrated that quantum data generated by a quantum key distribution (QKD) scheme can be transmitted during these quiet periods with high fidelity.

While building a purely quantum network could avoid the problem of crosstalk altogether, the researchers explain that combining quantum channels with classical channels is by far the more practical option.

“I see this as an absolute requirement – a ‘must have,’ Townsend said. “That’s because optical fiber network infrastructure is enormously expensive to deploy, so it must last for a long time – perhaps 25 years or more – and be able to support a wide range of current and future, yet to be defined, systems and services. So it is extremely unlikely that an operator would ever deploy a network, or even dedicate fibers within an existing network, purely for quantum communications – it’s just too expensive to do so. Consequently, we have to develop techniques that enable classical and quantum channels to work together on the same network if we want quantum communication systems to become a practical reality.”

By demonstrating that both quantum and classical information can be transmitted on a single optical fiber network in a way that satisfies real-world requirements, the researchers hope to bring quantum information technology one step closer to commercial applications.

“As we have demonstrated, in principle the technology to do this is available now,” Townsend. “However, in reality further research is likely to be required to reduce the cost and improve the performance of certain key parts of the system such as the single photon detectors, before widespread applications emerge. In general, the ‘value proposition’ for QKD on FTTH and other networks is under intensive discussion today, but at the moment no clear consensus has emerged concerning if and when it might be adopted to replace classical encryption techniques. However, as demonstrated by this research, the QKD field is not standing still and systems are continuing to evolve to become more practical, improving the potential for adoption of the technology in the future.”

More information: Iris Choi, et al. “Quantum information to the home.” New Journal of Physics 13 (2011) 063039 DOI:10.1088/1367-2630/13/6/063039

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New scientific research reveals diamonds aren't forever

New scientific research reveals diamonds aren't forever

  10:19:00 AM    Science Lover

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In a paper published in the US journal Optical Materials Express this week, Macquarie University researchers show that even the earth's hardest naturally occurring material, the diamond, is not forever.

Evaporation of diamond induced by an ultraviolent
laser beam. Image courtesy Richard Mildren

Associate Professor Richard Mildren and his colleagues from the Macquarie University Photonics Research Centre discovered that diamonds evaporate under exposure to light.

"Although this type of light-induced evaporation has been observed in some materials, this is the first time it's been shown to occur for diamond," Mildren said.

The diamonds were exposed to intense light pulses in the UV-C band (the harsh ultraviolet rays filtered out by the ozone layer), and small pits in the diamond surface were visible after only a few seconds. The rate of mass loss in the diamond fell notably for lower light levels but the etching process still continued - albeit at a slower and slower pace, Mildren said.



But before diamond lovers around the world start to panic, he is quick to note that the rate of evaporation is very small and not noticeable under normal conditions. In fact, even under very bright UV conditions, such as intense sunlight or under a UV tanning lamp, it would take approximately the age of the universe - about 10 billion years - to see an observable distance, he said.

The findings not only provide clues about the long-term stability of diamonds, but also have broad implications for future research.

"It's a very practical discovery and we are now looking at how we can exploit this," Mildren said.

"If we can make structures in the diamonds that enable us to control the position of the light within a very narrow filament in the diamond, that's the first step to making smaller and more efficient optical devices such as those used in quantum computing and high performance lasers."

The discovery may also have implications as far reaching as the prospects for finding diamonds on the surface of other planets, Mildren said.

More information: Mildren, R. P. et al. Opt. Mater. Express 1, 576-585 (2011).

Provided by Macquarie University

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Automakers Give Flywheels a Spin An old technology could make hybrid cars much cheaper.

Automakers Give Flywheels a Spin An old technology could make hybrid cars much cheaper.

  10:01:00 AM    Science Lover

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The automakers Volvo and Jaguar are testing the possibility of using flywheels instead of batteries in hybrid electric vehicles to aid acceleration and help engines operate more efficiently. The devices could reduce fuel consumption by 20 percent and would cost a third as much as batteries. Volvo will begin road-testing a car with the technology this fall.

A computer model of Volvo's flywheel, with an outer section cut away. Credit: Volvo

In a flywheel system, energy from the wheels is used to spin a flywheel at high speeds. The flywheel continues spinning, storing energy until that motion can be transferred back to the wheels via a transmission. The idea isn't new, but it's hard to make flywheels efficient—a lot of energy can be lost to friction. In 1982, for example, GM engineered a flywheel system that was intended for its 1985 vehicles, but they canceled the project after discovering that the fuel efficiency improvements were less than half of what they'd expected. Advances in the technology now have automakers taking a second look. "Industry has gone from being skeptical to thinking it can be done, but there are enormous challenges," says Derek Crabb, vice president of powertrain engineering for Volvo.

Engineers who design Formula 1 race cars have tried to overcome the challenges of a flywheel system by using composite materials to save weight. To reduce friction, they've sealed the flywheels inside a vacuum chamber. In translating that system to passenger cars, automakers face the problem of how to maintain the vacuum, since the seals that connect the flywheel to a transmission aren't perfect.



This is fine in racing, where the system only has to last a couple of hours at a time, and can be overhauled by team mechanics. Consumer cars using a similar design would need a system to maintain the vacuum with pumps and valves—and that adds complexity and cost. In another approach, from the U.K. engineering firm Ricardo, the mechanical connection between the flywheel and the transmission is severed. Instead, energy from the flywheel is transferred to a transmission via magnets arranged around the circumference of the flywheel and in a ring outside the flywheel housing. By varying the ratio of the magnets in the flywheel to those arranged around it, it's possible to make the flywheel spin six times faster than the ring around it, which simplifies the transmission of energy.

One advantage of flywheel systems over batteries is their compact size. "Most hybrids with batteries provide a 15- to 25-kilowatt boost of power. The flywheel can deliver 60 kilowatts in a way smaller package," says Andrew Atkins, chief engineer of technology at Ricardo. The trade-off is that flywheels can't supply energy for very long.

Crabb says Volvo hasn't decided if it will use a system such as Ricardo's or something else to maintain the vacuum. Many challenges remain in bringing a flywheel hybrid to market. For instance, automakers will have to ensure that the systems can be durable, and can be manufactured on a large scale, he says. Flywheels will also have to compete with batteries and other electrical storage devices such as ultracapacitors, which are getting more powerful and less expensive. .

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Stem Cells: Nearing Goal of Using Patient's Own Cells to Make Stem Cells to Replace Lost or Diseased Tissue

Stem Cells: Nearing Goal of Using Patient's Own Cells to Make Stem Cells to Replace Lost or Diseased Tissue

  1:27:00 AM    Science Lover

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Scientists at the Salk Institute for Biological Studies have developed an improved technique for generating large numbers of blood cells from a patient's own cells. The new technique will be immediately useful in further stem cell studies, and when perfected, could be used in stem cell therapies for a wide variety of conditions including cancers and immune ailments.

Round hematopoietic (blood) cells emerge from 
differentiating human pluripotent stem cells. 
(Credit: Courtesy of Aaron Parker, Salk Institute 
for Biological Studies)

"There are further improvements that we need to make, but this takes us a significant step closer to the ultimate goal, which is to be able to take ordinary cells from a patient, induce them to become stem cells, and then use those stem cells to rebuild lost or diseased tissues, for example the patient's bone marrow," says Inder M. Verma, PhD, Irwin and Joan Jacobs Chair in Exemplary Life Science and American Cancer Society Professor of Molecular Biology at the Salk Institute Laboratory of Genetics. Verma is senior author of the report, which is published in the July edition of the journal Stem Cells.

Stem cell researchers have been racing towards this goal since 2006, when techniques for turning ordinary skin cells into induced pluripotential stem cells (iPSCs) were first reported. In principle, iPSCs mimic the embryonic stem cells (ESCs) from which organisms develop. Researchers now want to find the precise mixes and sequences of chemical compounds needed to coax iPSCs to mature into the tissue-specific stem cells of their choice. The latter are self-renewing, and can be transplanted into the body to produce the 'progenitor' cells that multiply locally and produce mature tissue cells.

However, researchers don't know yet how to induce iPSCs to become tissue-specific stem cells or mature tissue cells with high efficiency. "We've been producing these cells in quantities that are too low to enable them to be studied easily, much less used for therapies," says Aaron Parker, PhD, a former graduate student and now a postdoctoral researcher in Verma's lab. Parker is a co-lead-author of the paper, with Niels-Bjarne Woods, PhD, who was a postdoctoral researcher in the Verma lab at the outset of the project, and is now an assistant professor at Lund University in Sweden.

Like many other stem cell research laboratories, the Verma lab has been trying to find more efficient ways to turn iPSCs into blood-forming 'hematopoietic' stem cells (HSCs). These may be more valuable medically than any other tissue-specific stem cell, because they can supply not only oxygen-carrying red blood cells but also all the white blood cells of the immune system. "There would be an almost unlimited number of usages for true HSCs," says Verma.

For the present study, the research team sought to do a better job of mimicking the changing conditions that naturally direct ESCs to become HSCs in the womb. "We took seven lines of human ESCs and iPSCs, and experimented with different combinations and sequences of growth factors and other chemical compounds that are known to be present as ESCs move to the HSC state in a developing human," says Parker.



Applying cocktails of these factors, Parker and Woods and their colleagues induced the iPSCs and ESCs to form colonies of cells that bore the distinctive molecular markers of blood cells. With their best such cocktail they were able to detect blood-specific markers on 84% of their cells after three weeks. "That's a big jump in efficiency from what we saw in the field just a few years ago," says Parker.

The technique still has room for improvement. The researchers detected progenitor cells and mature cells from only one category or lineage: myeloid cells, which include red blood cells and primitive immune cells such as macrophages. "We didn't see any cells from the lymphoid lineage, meaning T-cells and B-cells," Parker says.

Another drawback was that the blood cell population they produced from ESCs and iPSCs contained short-lived progenitors and mature blood cells but no indefinitely renewing, transplantable HSCs. Their cocktail, they believed, either pushed the cells past the HSC state to the progenitor state too quickly, or made the maturing cells skip the HSC state entirely.

From this and other labs' results, the team hypothesized the existence of an intermediate, pre-hematopoietic type of stem cell, produced by ESCs and iPSCs and in turn producing HSCs. "We know that HSCs appear in a particular region of mammals during embryonic development, and our idea is that these pre-hematopoietic stem cells are there and are somehow made to mature into HSCs," says Parker. "So our lab is now going to focus on finding the precise maturation signals provided by that embryonic region to produce these true, transplantable HSCs."

Once that is done, researchers will need to make a number of further refinements to improve the safety of HSCs intended for human patients. "But we're now tantalizingly close to our ultimate goal," says Verma.

The other authors who contributed to the work were Roksana Moraghebi, of Lund University's Stem Cell Center; Margaret K. Lutz, Amy L. Firth, Kristen J. Brennand, W. Travis Berggren and Fred H. Gage of the Salk Institute Laboratory for Genetics; Juan Carlos Izpisúa Belmonte of the Salk Institute Gene Expression Laboratory; and Angel Raya of the Center of Regenerative Medicine in Barcelona, Spain.

Funding for this research was provided by the National Institutes for Health, the California Institute for Regenerative Medicine, the Leducq Foundation, the Merieux Foundation, the Ellison Medical Foundation, Ipsen/Biomeasure, Sanofi Aventis, the Prostate Cancer Foundation, the H.N. and Frances C. Berger Foundation, The Royal Physiographic Society of Sweden, the Lund University Medical Faculty, and the Lars Hierta Memorial Foundation, and the H.A. and Mary K. Chapman Charitable Trust.

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Early Talking Doll Recording Discovered

Early Talking Doll Recording Discovered

  10:19:00 AM    Science Lover

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On May 11, 2011, scientists at the Lawrence Berkeley National Laboratory in Berkeley, California recovered sound from an artifact that historians believe is the earliest surviving talking doll record. The artifact is a ring-shaped cylinder phonograph record made of solid metal, preserved by the National Park Service at Thomas Edison National Historical Park. Phonograph inventor Thomas Edison made the record during the fall or winter of 1888 in West Orange, New Jersey.

The cylinder phonograph record. (Credit: Image 
courtesy of National Park Service)

On the recording, an unidentified woman recites one verse of the nursery rhyme "Twinkle, twinkle, little star." The voice captured on the 123-year-old record had been unheard since Edison's lifetime. The recording represents a significant milestone in the early history of recorded sound technology.

Recovering and Identifying the Sound

The metal record is significantly bent out of its original round, cylindrical shape. For this reason, curators at Thomas Edison National Historical Park were unable to play the recording using conventional methods. At the Lawrence Berkeley National Laboratory, Senior Scientist Carl Haber and Computer Systems Engineer Earl Cornell used a three-dimensional optical scanning technology developed during 2007-2009, in collaboration with the Library of Congress, to create a digital model of the surface of the record. With this digital model, they used modern image analysis methods to reproduce the audio stored on the record, saving it as a WAV-format digital audio file. They were able to recover all but the first syllable of the first word of the recording. Once the recording could be heard, historian Patrick Feaster of Indiana University played a key role in identifying and dating the recording by finding relevant references among archival documents. Researcher René Rondeau of Corte Madera, California provided additional fact-checking assistance.

Talking Doll Records Made of Tin



In search of a market for his invention the phonograph, Edison first attempted to make talking dolls during 1888. The prototype model described in laboratory notes and newspaper articles between September and December of that year was distinctive for using a record made of solid tin. In November 1888, the New York Evening Sun announced that Edison's talking dolls had just been "perfected," and that "nothing remains but to manufacture them in large quantities." No commercially viable method of duplicating sound recordings had yet been developed, so Edison hired women with suitable voices to make as many records as he thought would be needed once his talking dolls were put on the market: "There were two young ladies in the room...who were continually talking to the tiny speaking machines, which a skilled workman was turning out in great numbers."

Significance of the Recording

According to Feaster, this New York Evening Sun report marks the first time anyone is known to have been employed specifically to perform for the phonograph, so these women were arguably the world's first professional recording artists. If the goal was to stockpile these tin records "in large quantities" to supply the eventual demand for talking dolls, as the New York Evening Sun suggests, then they may also have been the first phonograph recordings ever manufactured for sale to the public, even though they were never actually sold.

It was more than a year later, in April 1890, when Edison placed a talking doll on the market. By that time, however, he had switched the design to use records made of wax rather than tin. The dolls failed to sell because they broke too easily -- due in part to the fragility of the records. It is unclear why Edison switched from tin to wax records for the talking doll.

Provenance of the Artifact

National Park Service museum curators first cataloged the object in 1967, found among items left in the desk of Edison's secretary William H. Meadowcroft, located in the library of the Edison Laboratory in West Orange, New Jersey. A paper tag found tied to the cylinder reads: "Tin Phonograph Cylinder […]l Record." The artifact is the only example of a talking doll record from 1888 known to survive today.

Hear the recording. www.nps.gov/edis/photosmultimedia/talking-doll-record-hear-the-recording.htm

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