Ideas, Inventions And Innovations

Potatoes Provide One Of The Best Nutritional Values Per Penny

2013-05-24T16:58:00.000-04:00

A frequently expressed concern in the ongoing public health debate is the lack of affordability of fresh vegetables, especially those that are nutrient dense. A new study, "Vegetable Cost Metrics Show That Potatoes and Beans Provide Most Nutrients Per Penny," published in the journal PLOS ONE, shows that potatoes are one of the best nutritional values in the produce aisle, providing one of the better nutritional values per penny than most other raw vegetables and delivering one of the most affordable source of potassium of the more frequently consumed vegetables, second only to beans.

Dr. Adam Drewnowski and colleagues from the University of Washington used a combination of nutrient profiling methods and national food prices data to create an "affordability index," which was then used to examine the nutrients per unit cost of 98 individual vegetables as well as five vegetable subgroups including dark green, orange/red, starchy, legumes (beans and peas) and "other" vegetables.

The results indicated while dark green vegetables had the highest nutrient density scores, after accounting for cost, starchy vegetables (including potatoes) and beans provided better nutritional value for the money. Potatoes, in particular, provide one of the lowest cost options for four key nutrients including potassium, fiber, vitamin C and magnesium. Among the most frequently consumed vegetables, potatoes and beans were the lowest-cost sources of potassium and fiber—nutrients of concern, as identified by the 2010 USDA Dietary Guidelines.

"The ability to identify affordable, nutrient dense vegetables is important to families focused on stretching their food dollar as well as government policy makers looking to balance nutrition and economics for food programs such as the school lunch program and WIC," said lead researcher Adam Drewnowski, PhD. "And, when it comes to affordable nutrition, it's hard to beat potatoes."

The study was funded by the United States Potato Board and adds to the growing database of nutrition science that supports potatoes in a healthful diet. In addition, one medium-size (5.3 ounce) skin-on potato contains just 110 calories per serving, boasts more potassium (620g) than a banana (450g), provides almost half the daily value of vitamin C (45 percent), and contains no fat, sodium or cholesterol.

Contacts and sources:
Meredith Myers
Fleishman-Hillard, Inc.

New Filtration Material Could Make Petroleum Refining Cheaper, More Efficient

2013-05-24T16:50:00.003-04:00

A newly synthesized material might provide a dramatically improved method for separating the highest-octane components of gasoline. Measurements at the National Institute of Standards and Technology (NIST) have clarified why. The research team, which included scientists from NIST and several other universities, has published its findings in the journal Science.*

This view of the molecular structure of the MOF shows the triangular channels that run through the material. The walls of these channels trap the lower-octane components of gas while allowing the higher-octane molecules to pass through, potentially providing a more efficient and cost effective way to refine high-octane gasoline.

Credit: Science/AAAS

Created in the laboratory of Jeffrey Long, professor of chemistry at the University of California, Berkeley, the material is a metal-organic framework, or MOF, which can be imagined as a sponge with microscopic holes. The innumerable interior walls of the MOF form triangular channels that selectively trap only the lower-octane components based on their shape, separating them easily from the higher-octane molecules in a way that could prove far less expensive than the industry's current method. The Long laboratory and UC Berkeley have applied for a patent on the MOF, which is known by its chemical formula, Fe2(bdp)3.

High-octane gasolines, the ultra or premium blends at fueling stations, are more expensive than regular unleaded gasoline due to the difficulty of separating out the right type of molecules from petroleum. Petroleum includes several slightly different versions of the same molecule that have identical molecular formulae but varying shapes—called isomers. Creating premium fuel requires a refinery to boil the mixture at precise temperatures to separate the isomers with the most chemical energy. The trouble is, four of these isomers—two of which are high octane, the other two far lower—have only slightly different boiling points, making the overall process both challenging and costly.

The new MOF, however, could allow refineries to sidestep this problem by essentially trapping the lowest-octane isomers while letting the others pass through. The lowest-octane isomers are more linear and can nestle closer to the MOF walls, so when a mixture of isomers passes through the MOF, the less desired isomers stick to its surface—somewhat akin to the way a wet piece of paper sticks to a wall.

Matthew Hudson and his colleagues at the NIST Center for Neutron Research (NCNR) used neutron powder diffraction, a technique for determining molecular structure, to explore why the MOF has the right shape to selectively separate the isomers. Their research was essential to validate the team's model of how the MOF adsorbs the low-octane isomers.

"It's easier to separate the isomers with higher octane ratings this way rather than with the standard method, making it more efficient," says Hudson, a postdoctoral fellow at the NCNR. "And based on the lower temperatures needed, it's also far less energy-intensive, meaning it should be less expensive." Hudson adds that while industrial scientists will need to work out how to apply the discovery in refineries, the new MOF appears to be robust enough in harsh conditions to be used repeatedly a great many times, potentially reducing the necessary investment by a petroleum company.
* Z.R. Herm, B.M. Wiers, J.A. Mason, J.M. van Baten, M.R. Hudson, P. Zajdel, C.M. Brown, N. Masciocchi, R. Krishna and J.R. Long. Separation of hexane isomers in a metal-organic framework with triangular channels. Science, May 24, 2013. DOI: 10.1126/science.12334071

Contacts and sources:

Chad Boutin
NIST

The Better to See You With: Scientists Build Record-Setting Metamaterial Flat Lens

2013-05-24T15:02:00.001-04:00

For the first time, scientists working at the National Institute of Standards and Technology (NIST) have demonstrated a new type of lens that bends and focuses ultraviolet (UV) light in such an unusual way that it can create ghostly, 3D images of objects that float in free space. The easy-to-build lens could lead to improved photolithography, nanoscale manipulation and manufacturing, and even high-resolution three-dimensional imaging, as well as a number of as-yet-unimagined applications in a diverse range of fields.

A NIST team has created an ultraviolet (UV) metamaterial formed of alternating nanolayers of silver (green) and titanium dioxide (blue). The metamaterial has an angle-independent negative refractive index, enabling it to act as a flat lens. When illuminated with UV light (purple) a sample object of any shape placed on the flat slab of metamaterial is projected as a three-dimensional image in free space on the other side of the slab. Here a ring-shaped opening in an opaque sheet on the left of the slab is replicated in light on the right.Bottom left: Scanning electron micrograph of a ring-shaped opening in a chromium sheet located on the surface of a flat slab of metamaterial. Bottom right: Optical micrograph of the image projected beyond the slab under UV illumination, demonstrating that the metamaterial slab acts as a flat lens.

Credit: Lezec/NIST

"Conventional lenses only capture two dimensions of a three-dimensional object," says one of the paper's co-authors, NIST's Ting Xu. "Our flat lens is able to project three-dimensional images of three-dimensional objects that correspond one-to-one with the imaged object."

An article published in the journal Nature* explains that the new lens is formed from a flat slab of metamaterial with special characteristics that cause light to flow backward—a counterintuitive situation in which waves and energy travel in opposite directions, creating a negative refractive index.

Naturally occurring materials such as air or water have a positive refractive index. You can see this when you put a straw into a glass of water and look at it from the side. The straw appears bent and broken, as a result of the change in index of refraction between air, which has an index of 1, and water, which has an index of about 1.33. Because the refractive indices are both positive, the portion of the straw immersed in the water appears bent forward with respect to the portion in air.

The negative refractive index of metamaterials causes light entering or exiting the material to bend in a direction opposite what would occur in almost all other materials. For instance, if we looked at our straw placed in a glass filled with a negative-index material, the immersed portion would appear to bend backward, completely unlike the way we're used to light behaving.

In 1967, Russian physicist Victor Veselago described how a material with both negative electric permittivity and negative magnetic permeability would have a negative index of refraction. (Permittivity is a measure of a material's response to an applied electric field, while permeability is a measure of the material's response to an applied magnetic field.)

Veselago reasoned that a material with a refractive index of -1 could be used to make a lens that is flat, as opposed to traditional refractive lenses, which are curved. A flat lens with a refractive index of -1 could be used to directly image three-dimensional objects, projecting a three-dimensional replica into free space.

A negative-index flat lens like this has also been predicted to enable the transfer of image details substantially smaller than the wavelength of light and create higher-resolution images than are possible with lenses made of positive-index materials such as glass.

It took over 30 years from Veselago's prediction for scientists to create a negative-index material in the form of metamaterials, which are engineered on a subwavelength scale. For the past decade, scientists have made metamaterials that work at microwave, infrared and visible wavelengths by fabricating repeating metallic patterns on flat substrates. However, the smaller the wavelength of light scientists want to manipulate, the smaller these features need to be, which makes fabricating the structures an increasingly difficult task. Until now, making metamaterials that work in the UV has been impossible because it required making structures with features as small as 10 nanometers, or 10 billionths of a meter.

Moreover, because of limitations inherent in their design, metamaterials of this type designed for infrared and visible wavelengths have, so far, been shown to impart a negative index of refraction to light that is traveling only in a certain direction, making them hard to use for imaging and other applications that rely on refracted light.

To overcome these problems, researchers working at NIST took inspiration from a theoretical metamaterial design recently proposed by a group at the FOM Institute for Atomic and Molecular Physics in Holland. They adapted the design to work in the UV—a frequency range of particular technological interest.

According to co-authors Xu, Amit Agrawal and Henri Lezec, aside from achieving record-short wavelengths, their metamaterial lens is inherently easy to fabricate. It doesn't rely on nanoscale patterns, but instead is a simple sandwich of alternating nanometer-thick layers of silver and titanium dioxide, the construction of which is routine. And because its unique design consists of a stack of strongly coupled waveguides sustaining backward waves, the metamaterial exhibits a negative index of refraction to incoming light regardless of its angle of travel.

This realization of a Veselago flat lens operating in the UV is the first such demonstration of a flat lens at any frequency beyond the microwave. By using other combinations of materials, it may be possible to make similarly layered metamaterials for use in other parts of the spectrum, including the visible and the infrared.

The metamaterial flat lens achieves its refractive action over a distance of about two wavelengths of UV light, about half a millionth of a meter—a focal length challenging to achieve with conventional refractive optics such as glass lenses. Furthermore, transmission through the metamaterial can be turned on and off using higher frequency light as a switch, allowing the flat lens to also act as a shutter with no moving parts.

"Our lens will offer other researchers greater flexibility for manipulating UV light at small length scales," says Lezec. "With its high photon energies, UV light has a myriad of applications, including photochemistry, fluorescence microscopy and semiconductor manufacturing. That, and the fact that our lens is so easy to make, should encourage other researchers to explore its possibilities."

The new work was performed in collaboration with researchers from the Maryland NanoCenter at the University of Maryland, College Park; Syracuse University; and the University of British Columbia, Kelowna, Canada.

Contacts and sources:

Charles Boutin

NIST

Citation: * T. Xu, A. Agrawal, M. Abashin, K.J. Chau and H.J. Lezec. All-angle negative refraction and active flat lensing of ultraviolet light. Nature. 497, 470–474 Published online: May 23. 2013. doi:10.1038/nature12158

Water Apocalypse Looming

2013-05-24T14:22:00.004-04:00

Bonn Declaration issued by 500 scientists at 'Water in the Anthropocene' conference

A conference of 500 leading water scientists from around the world today issued a stark warning that, without major reforms, "in the short span of one or two generations, the majority of the 9 billion people on Earth will be living under the handicap of severe pressure on fresh water, an absolutely essential natural resource for which there is no substitute. This handicap will be self-inflicted and is, we believe, entirely avoidable."

This is an image of North America from the data visualization video "Water in the Anthropocene," to debut May 21 at gwsp.org and www.anthropocene.info.

Credit: gwsp.org/ www.anthropocene.info

The scientists bluntly pointed to chronic underlying problems led by mismanagement and sent a prescription to policy makers in a 1,000-word declaration issued at the end of a four-day meeting in Bonn, Germany, "Water in the Anthropocene," organized by the Global Water System Project.

A suite of disquieting global phenomena have given rise to the "Anthropocene," a term coined for a new geologic epoch characterized by humanity's growing dominance of the Earth's environment and a planetary transformation as profound as the last epoch-defining event -- the retreat of the glaciers 11,500 years ago.

And in Bonn, Germany May 21-24, world experts will experts will focus on how to mitigate key factors contributing to extreme damage to the global water system being caused while adapting to the new reality.

Water in the Anthropocene from WelcomeAnthropocene on Vimeo.

"The list of human activities and their impact on the water systems of Planet Earth is long and important," Anik Bhaduri, Executive Officer of the Global Water System Project (GWSP).

"We have altered the Earth's climatology and chemistry, its snow cover, permafrost, sea and glacial ice extent and ocean volume—all fundamental elements of the hydrological cycle. We have accelerated major processes like erosion, applied massive quantities of nitrogen that leaks from soil to ground and surface waters and, sometimes, literally siphoned all water from rivers, emptying them for human uses before they reach the ocean. We have diverted vast amounts of freshwater to harness fossil energy, dammed major waterways, and destroyed aquatic ecosystems."

"The idea of the Anthropocene underscores the point that human activities and their impacts have global significance for the future of all living species -- ours included. Humans are changing the character of the world water system in significant ways with inadequate knowledge of the system and the consequences of changes being imposed. From a research position, human-water interactions must be viewed as a continuum and a coupled system, requiring interdisciplinary inquiry like that which has characterized the GWSP since its inception."

Among many examples of humanity's oversized imprint on the world, cited in a paper by James Syvitski, Chair of the International Geosphere-Biosphere Programme and three fellow experts (in full: http://bit.ly/Yx4COp), and in a new "Water in the Anthropocene" video to debut in Bonn May 21 (available at gwsp.org and http://www.anthropocene.info):

This is an image of Europe from the data visualization video "Water in the Anthropocene," to debut May 21 at gwsp.org and www.anthropocene.info.

Credit: gwsp.org/ www.anthropocene.info

Humanity uses an area the size of South America to grow its crops and an area the size of Africa for raising livestock

Due to groundwater and hydrocarbon pumping in low lying coastal areas, two-thirds of major river deltas are sinking, some of them at a rate four times faster on average than global sea level is rising

More rock and sediment is now moved by human activities such as shoreline in-filling, damming and mining than by the natural erosive forces of ice, wind and water combined

Many river floods today have links to human activities, including the Indus flood of 2010 (which killed 2,000 people), and the Bangkok flood of 2011 (815 deaths)

On average, humanity has built one large dam every day for the last 130 years. Tens of thousands of large dams now distort natural river flows to which ecosystems and aquatic life adapted over millennia

Drainage of wetlands destroys their capacity to ease floods—a free service of nature expensive to replace

Evaporation from poorly-managed irrigation renders many of the world's rivers dry -- no water, no life. And so, little by little, tens of thousands of species edge closer to extinction every day.

Needed: Better water system monitoring and governance

The water community stresses that concern now extends far beyond 'classic' drinking water and sanitation issues and includes water quality and quantity for ecosystems at all scales.

Says GWSP co-chair Claudia Pahl-Wostl: "The fact is, as world water problems worsen, we lack adequate efforts to monitor the availability, condition and use of water -- a situation presenting extreme long term cost and danger."

"Human water security is often achieved in the short term at the expense of the environment with harmful long-term implications. The problems are largely caused by governance failure and a lack of systemic thinking in both developed and developing countries. Economic development without concomitant institutional development will lead to greater water insecurity in the long-term. Global leadership is required to deal with the water challenges of the 21st century."

This is an image of Africa from the data visualization video "Water in the Anthropocene," to debut May 21 at gwsp.org and www.anthropocene.info.

Credit: gwsp.org/ www.anthropocene.info

"Humanity changes the way water moves around the globe like never before, causing dramatic harm," says Bonn conference keynote speaker Joe Alcamo, Chief Scientist of the UN Environment Programme and former co-chair of the GWSP. "By diverting freshwater for agricultural, industrial and municipal use, for example, our coastal wetlands receive less and less, and often polluted, freshwater. The results include decreased inland and coastal biodiversity, increased coastal salinity and temperature, and contaminated agricultural soils and agricultural runoff."

Adds Charles Vörösmarty, co-Chair and a founding member of the GWSP, which receives input from more hundreds of international scientists: "By throwing concrete, pipes, pumps, and chemicals at our water problems, to the tune of a half-trillion dollars a year, we've produced a technological curtain separating clean water flowing from our pipes and the highly-stressed natural waters that sit in the background. We treat symptoms of environmental abuse rather than underlying causes. Thus, problems continue to mount in the background, yet the public is largely unaware of this reality or its growing costs."

Aims of the Bonn meeting

Featuring 60 special topic sessions, "Water in the Anthropocene" is a capstone event for the GWSP, which is developing "Future Water," the water-related component of the emerging new multi-dimensional international collaborative environmental research framework, Future Earth.

A goal of the meeting is to synthesize major global water research achievements in the last decade and help assembling the scientific foundations to articulate a common vision of Earth's water future.

It will recommended priorities for decision makers in the areas of earth system science and water resources governance and management.

And it will constitute a scientific prelude to October's Budapest Water Summit, a major objective of which is to elevate the importance of water issues within the UN General Assembly negotiations on the Sustainable Development Goals -- a set of globally-agreed future objectives to succeed the UN Millennium Development Goals in 2015.

Observers expect adoption of "water security" as a Sustainable Development Goal

Water expert Janos Bogardi, Senior Advisor to GWSP, says the absence of defined global water quantity and quality standards for personal use, agriculture and healthy ecosystems are critical gaps as the world community develops its next set of shared medium-term objectives.

"These definitions constitute a cardinal challenge today for scientists and politicians alike. It is important to reach consensus in order to make progress on the increasingly important notion of 'water security'," says Dr. Bogardi, stressing that changing terminology will not in itself solve problems. "Replacing the word 'sustainability' with 'security' is not a panacea."

With respect to quantity, less than 20 liters daily for sanitary needs and drinking is deemed "water misery" while 40 to 80 liters is considered "comfortable." (Current US per capita average daily consumption is over 300 liters; daily usage in urban Germany is about 120 liters per capita and in urban Hungary, where water is relatively expensive, the figure is 80 liters.)

Missing also are authoritative scientific determinations of how much water can be drawn without crossing a "tipping point" threshold into ecosystem collapse. While there is no general rule, GWSP scientists say withdrawals of 30% to 40% of a renewable freshwater resource constitutes "extreme" water stress, but underline scope to continue satisfying needs if water is returned and recycled in good quality. Mining fossil groundwater resources is by definition non-sustainable.

The GWSP is developing water quality guidelines for people, agriculture and ecosystems in the context of the Sustainable Development Goals.

"The urgency of formulating the post-2015 Sustainable Development Goals and a tracking system for their success means that quite soon the SDG negotiators must offer-up water targets," says Dr. Vörösmarty. "Whether they focus predominantly on continuing the Millennium Development Goals (narrowly on drinking water and sanitation for human health) or formulate a more comprehensive agenda that simultaneously optimizes water security for humans as well as for nature remains an open question. The water sciences community stands ready to take on this challenge. Are the the decision makers?"

Definitions of water security

In 2007, World Bank expert David Grey and Claudia Sadoff of IUCN, defined water security as "The availability of an acceptable quantity and quality of water for health, livelihoods, ecosystems and production, coupled with an acceptable level of water-related risks to people, environments and economies."

Their use of the term "acceptable" acknowledges that water security has relative, negotiable meanings.

In March, another formulation was set out by UN-Water, the United Nations' inter-agency coordination mechanism for all water-related issues.

It defined water security as: "The capacity of a population to safeguard sustainable access to adequate quantities of and acceptable quality water for sustaining livelihoods, human well-being, and socio-economic development, for ensuring protection against water-borne pollution and water-related disasters, and for preserving ecosystems in a climate of peace and political stability." (seehttp://bit.ly/1864vMG)

The full text of The Bonn Declaration:
In the short span of one or two generations, the majority of the 9 billion people on Earth will be living under the handicap of severe pressure on fresh water, an absolutely essential natural resource for which there is no substitute. This handicap will be self-inflicted and is, we believe, entirely avoidable.

After years of observations and a decade of integrative research convened under the Earth System Science Partnership (ESSP) and other initiatives, water scientists are more than ever convinced that fresh water systems across the planet are in a precarious state.

Mismanagement, overuse and climate change pose long-term threats to human well-being, and evaluating and responding to those threats constitutes a major challenge to water researchers and managers alike. Countless millions of individual local human actions add up and reverberate into larger regional, continental and global changes that have drastically changed water flows and storage, impaired water quality, and damaged aquatic ecosystems.

Human activity thus plays a central role in the behavior of the global water system.

Since 2004, the Global Water System Project (GWSP) has spearheaded a broad research agenda and new ways of thinking about water as a complex global system, emphasizing the links that bind its natural and human components. Research carried out by GWSP and its partners has produced several important results that inform a better global understanding of fresh water today.

Humans are a key feature of the global water system, influencing prodigious quantities of water: stored in reservoirs, taken from rivers and groundwater and lost in various ways. Additional deterioration through pollution, now detectable on a global scale, further limits an already-stressed resource base, and negatively affects the health of aquatic life forms and human beings.

At a time of impending water challenges, it remains a struggle to secure the basic environmental and social observations needed to obtain an accurate picture of the state of the resource. We need to know about the availability, condition and use of water as part of a global system through sustained environmental surveillance. History teaches us that failure to obtain this basic information will be costly and dangerous.

Humans typically achieve water security through short-term and often costly engineering solutions, which can create long-lived impacts on social-ecological systems. Faced with a choice of water for short-term economic gain or for the more general health of aquatic ecosystems, society overwhelmingly chooses development, often with deleterious consequences on the very water systems that provide the resource.

Traditional approaches to development are counterproductive, destroying the services that healthy water systems provide, such as flood protection, habitat for fisheries and pollution control. Loss of these services will adversely affect current and future generations.

Sustainable development requires both technological and institutional innovation. At present, the formulation of effective institutions for the management of water lags behind engineering technologies in many regions.

Research from the GWSP and elsewhere confirms that current increases in the use of water and impairment of the water system are on an unsustainable trajectory. However, current scientific knowledge cannot predict exactly how or precisely when a planetary-scale boundary will be breached. Such a tipping point could trigger irreversible change with potentially catastrophic consequences.

The existing focus on water supply, sanitation and hygiene has delivered undoubted benefits to people around the world, but equally, we need to consider wider Sustainable Development Goals in the context of the global water system. Ecosystem-based sustainable water management, a pressing need that was reaffirmed at the Rio+20 Earth Summit, requires that solving water problems must be a joint obligation of environmental scientists, social scientists, engineers, policy-makers, and a wide range of stakeholders.

These realities motivate the water community assembled in Bonn for the Global Water System Project Conference "Water in the Anthropocene" to make a set of core recommendations to institutions and individuals focused on science, governance, management and decision-making relevant to water resources on earth. Given the development imperatives associated with all natural resources at the dawn of the 21st century, we urge a united front to form a strategic partnership of scientists, public stakeholders, decision-makers and the private sector. This partnership should develop a broad, community-consensus blueprint for a reality-based, multi-perspective, and multi-scale knowledge-to-action water agenda, based on these recommendations:

1) Make a renewed commitment to adopt a multi-scale and interdisciplinary approach to water science in order to understand the complex and interlinked nature of the global water system and how it may change now and in future.

2) Execute state-of-the-art synthesis studies of knowledge about fresh water that can inform risk assessments and be used to develop strategies to better promote the protection of water systems.

3) Train the next generation of water scientists and practitioners in global change research and management, making use of cross-scale analysis and integrated system design.

4) Expand monitoring, through traditional land-based environmental observation networks and state-of-the-art earth-observation satellite systems, to provide detailed observations of water system state.

5) Consider ecosystem-based alternatives to costly structural solutions for climate proofing, such that the design of the built environment in future includes both traditional and green infrastructure.

6) Stimulate innovation in water institutions, with a balance of technical- and governance-based solutions and taking heed of value systems and equity. A failure to adopt a more inclusive approach will make it impossible to design effective green growth strategies or policies.

A new geologic epoch, "The Anthropocene," is characterized by humanity's growing dominance of Earth's environment and a planetary transformation as profound as the last epoch-defining event -- the retreat of the glaciers 11, 500 years ago.

Among examples of humans' planet-altering imprint on the world:

Humanity uses an area the size of South America to grow its crops and an area the size of Africa for raising livestock

Due to groundwater and hydrocarbon pumping in low lying coastal areas, two-thirds of major river deltas are sinking, some of them at a rate four times faster on average than global sea level is rising

More rock and sediment is now moved by human activities such as shoreline in-filling, damming and mining than by the natural erosive forces of ice, wind and water combined

Many river floods today have links to human activities, including the Indus flood of 2010 (which killed 2,000 people), and the Bangkok flood of 2011 (815 deaths)

On average, humanity has built one large dam every day for the last 130 years. Tens of thousands of large dams now distort natural river flows to which ecosystems and aquatic life adapted over millennia

Drainage of wetlands destroys their capacity to ease floods-a free service of nature expensive to replace

Evaporation from poorly-managed irrigation renders many of the world's rivers dry -- no water, no life. And so, little by little, tens of thousands of species edge closer to extinction every day
The recommendations above, taken collectively, can constitute the centrepiece of a blueprint to promote the adoption of science-based evidence into the formulation of goals for sustainable development. Stewardship requires balancing the needs of humankind and the needs of nature through the protection of ecosystems and the services that they provide. Without such a design framework, we anticipate highly fragmented decision-making and the persistence of maladaptive approaches to water management.

Contacts and sources:
Terry Collins
Global Water System Project

Facial Recognition Technology Getting More Powerful

2013-05-24T14:17:00.001-04:00

In a study that evaluated some of the latest in automatic facial recognition technology, researchers at Michigan State University were able to quickly identify one of the Boston Marathon bombing suspects from law enforcement video, an experiment that demonstrated the value of such technology.

In the Pattern Recognition and Image Processing laboratory, Anil Jain, MSU Distinguished Professor of computer science and engineering, and Josh Klontz, a research scientist, tested three different facial-recognition systems.

Top three retrievals in a blind search with NeoFace 3.1.

Credit: Anil Jain and Josh Klontz, Michigan State University

By using actual law-enforcement video from the bombing, they found that one of the three systems could provide a “rank one” identification – a match – of suspect Dzokhar Tsarnaev.

“The other suspect, Tamerlan Tsarnaev, the one ultimately killed in the shootout with police, could not be matched at a sufficiently high rank, partly because he was wearing sunglasses,” Jain said. “The younger brother could be identified.

“This study was revealing in that facial recognition technology can successfully handle some cases in which facial images extracted from a video were captured under favorable conditions,” he said.

Under controlled conditions, when the face is angled toward the camera and if the lighting is good, this technology can be up to 99 percent accurate.

Automatic face recognition can quickly attach a name to a face by searching a large database of face images and finding the closest match. This is what law enforcement agencies typically do for mug shot databases.

It is unknown, Jain said, what automatic facial recognition technologies were used by investigators in Boston. Some algorithms are better suited than others for face recognition in uncontrolled video.

While the technology has made great strides in recent years, it doesn’t mean that improvements aren’t needed. Also, more police agencies have to put the technology to use.

“If you use an automatic system, it speeds up the process,” Jain said. “Sometimes police get bad tips so innocent people are questioned. Such situations can be avoided with a robust and accurate face-recognition system.”

Jain and his team are internationally recognized in the field of identification technology. His team has developed methods to match forensic facial sketches with mug shots, as well as technology that allows police to identify criminal suspects by tattoo matching.

Klontz and Jain’s technical paper on evaluating automatic facial recognition technology can be viewed here.

Contacts and sources:
Tom Oswald
Michigan State University

Tracking The Earth’s Mantle

2013-05-24T14:09:00.002-04:00

From Virginia to Florida, there is a prehistoric shoreline that, in some parts, rests more than 280 feet above modern sea level. The shoreline was carved by waves more than 3 million years ago—possible evidence of a once higher sea level, triggered by ice-sheet melting. But new findings by a team of researchers, including Robert Moucha, assistant professor of Earth Sciences in The College of Arts and Sciences, reveal that the shoreline has been uplifted by more than 210 feet, meaning less ice melted than expected.

The East Coast shoreline, also known as the Orangeburg Scarp, as it may have appeared 3 million years ago.

Equally compelling is the fact that the shoreline is not flat, as it should be, but is distorted, reflecting the pushing motion of the Earth’s mantle.

This is big news, says Moucha, for scientists who use the coastline to predict future sea-level rise. It’s also a cautionary tale for those who rely almost exclusively on cycles of glacial advance and retreat to study sea-level changes.

“Three million years ago, the average global temperature was two to three degrees Celsius higher, while the amount of carbon dioxide in the atmosphere was comparable to that of today,” says Moucha, who contributed to a paper on the subject in the May 15 issue of Science Express. “If we can estimate the height of the sea from 3 million years ago, we can then relate it to the amount of ice sheets that melted. This period also serves as a window into what we may expect in the future.”

Moucha and his colleagues—led by David Rowley, professor of geophysical sciences at the University of Chicago—have been using computer modeling to pinpoint exactly what melted during this interglacial period, some 3 million years ago. So far, evidenced is stacked in favor of Greenland, West Antarctica and the sprawling East Antarctica ice sheet, but the new shoreline uplift implies that East Antarctica may have melted some or not at all. “It’s less than previous estimates had implied,” says Rowley, the article’s lead author.

Moucha’s findings show that the jagged shoreline may have been caused by the interplay between the Earth’s surface and its mantle—a process known as dynamic topography. Advanced modeling suggests that the shoreline, referred to as the Orangeburg Scarp, may have shifted as much as 196 feet. Modeling also accounts for other effects, such as the buildup of offshore sediments and glacial retreats.

“Dynamic topography is a very important contributor to Earth’s surface evolution,” says Rowley. “With this work, we can demonstrate that even small-scale features, long considered outside the realm of mantle influence, are reflective of mantle contributions.”

Building a case

Moucha’s involvement with the project grew out of a series of papers he published as a postdoctoral fellow at the Canadian Institute for Advance Research in Montreal. In one paper from 2008, he drew on elements of the North American East Coast and African West Coast to build a case against the existence of stable continental platforms.

“The North American East Coast has always been thought of as a passive margin,” says Moucha, referring to large areas usually bereft of tectonic activity. “[With Rowley], we’ve challenged the traditional view of passive margins by showing that through observations and numerical simulations, they are subject to long-term deformation, in response to mantle flow.”

Central to Moucha’s argument is the fact that viscous mantle flows everywhere, all the time. As a result, it’s nearly impossible to find what he calls “stable reference points” on the Earth’s surface to accurately measure global sea-level rise. “If one incorrectly assumed that a particular margin is a stable reference frame when, in actuality, it has subsided, his or her assumption would lead to a sea-level rise and, ultimately, to an increase in ice-sheet melt,” says Moucha, who joined SU’s faculty in 2011.

Another consideration is the size of the ice sheet. Between periods of glacial activity (such as the one from 3 million years ago and the one we are in now), ice sheets are generally smaller. Jerry Mitrovica, professor of geophysics at Harvard University who also contributed to the paper, says the same mantle processes that drive plate tectonics also deform elevations of ancient shorelines. “You can't ignore this, or your estimate of the size of the ancient ice sheets will be wrong,” he says.

Rise and fall

Moucha puts it this way: “Because ice sheets have mass and mass results in gravitational attraction, the sea level actually falls near the melting ice sheet and rises when it’s further away. This variability has enabled us to unravel which ice sheet contributed to sea-level rise and how much of [the sheet] melted.”

The SU geophysicist credits much of the group’s success to state-of-the-art seismic tomography, a geological imaging technique led by Nathan Simmons at California’s Lawrence Livermore National Laboratory. “Nathan, who co-authored the paper, provided me with seismic tomography data, from which I used high-performance computing to model mantle flow,” says Moucha. “A few million years may have taken us a day to render, but a billion years may have taken several weeks or more."

Moucha and his colleagues hope to apply their East Coast model to the Appalachian Mountains, which are also considered a type of passive geology. Although they have been tectonically quiet for more than 200 million years, the Appalachians are beginning to show signs of wear and tear: rugged peaks, steep slopes, landslides, and waterfalls—possible evidence of erosion, triggered by dynamic topography.

“Scientists, such as Rob, who produce increasingly accurate models of dynamic topography for the past, are going to be at the front line of this important research area,” says Mitrovica.

Adds Rowley: “Rob Moucha has demonstrated that dynamic topography is a very important contributor to Earth's surface evolution. … His study of mantle contributions is appealing on a large number of fronts that I, among others of our collaboration, hope to pursue."

Contacts and sources:
By Rob Enslin
Syracuse University

Major Astronomical Mystery Solved

2013-05-24T14:06:00.002-04:00

Sometimes astronomy is like real estate -- what's important is location, location, and location. Astronomers have resolved a major problem in their understanding of a class of stars that undergo regular outbursts by accurately measuring the distance to a famous example of the type.

Artist's conception of SS Cygni double-star system.

The researchers used the National Science Foundation's Very Long Baseline Array (VLBA) and the European VLBI Network (EVN) to precisely locate one of the most-observed variable-star systems in the sky -- a double-star system called SS Cygni -- at 370 light-years from Earth. This new distance measurement meant that an explanation for the system's regular outbursts that applies to similar pairs also applies to SS Cygni.

"This is one of the best-studied systems of its type, but according to our understanding of how these things work, it should not have been having outbursts. The new distance measurement brings it into line with the standard explanation," said James Miller-Jones, of the Curtin University node of the International Centre for Radio Astronomy Research in Perth, Australia.

SS Cygni, in the constellation Cygnus the Swan, is a dense white dwarf star in a close orbit with a less-massive red dwarf. The strong gravity of the white dwarf pulls material from its companion into a swirling disk surrounding the white dwarf. The two stars orbit each other in only about 6.6 hours. On an average of once every 49 days, a powerful outburst greatly brightens the system.

This type of system is called a dwarf nova, and, based on other examples, scientists proposed that the outbursts result from changes in the rate at which matter moves through the disk onto the white dwarf. At high rates of mass transfer from the red dwarf, the rotating disk remains stable, but when the rate is lower, the disk can become unstable and undergo an outburst.

This mechanism seemed to work for all known dwarf novae except for SS Cygni, based on previous distance estimates. Hubble Space Telescope measurements in 1999 and 2004 put SS Cygni at a distance of about 520 light-years.

"That was a problem. At that distance, SS Cygni would have been the brightest dwarf nova in the sky, and should have had enough mass moving through its disk to remain stable without any outbursts," Miller-Jones said.

The closer distance measured with the radio telescopes means that the system is intrinsically less bright, and now fits the characteristics outlined in the standard explanation for dwarf-nova outbursts, the scientists said.

The astronomers made the new distance measurement using the VLBA and EVN, both of which use widely-separated radio telescopes that work together as a single, extremely precise, telescope. These systems are capable of the most accurate measurements of positions in the sky available in astronomy.

Trigonometric Parallax method determines distance to star by measuring its slight shift in apparent position as seen from opposite ends of Earth's orbit.

Credit: Bill Saxton, NRAO/AUI/NSF

By observing SS Cygni when Earth is on opposite sides of its orbit around the Sun, astronomers can measure the subtle shift in the object's apparent position in the sky, compared to the background of more-distant objects. This effect, called parallax, allows scientists to directly measure an object's distance by applying simple, high-school trigonometry.

The astronomers knew that SS Cygni emits radio waves during its outbursts, so they made their radio-telescope observations after receiving reports from amateur astronomers that an outburst was underway. They observed the object during outbursts from 2010 to 2012.

The difference in the distance measurements between the Hubble visible-light and the radio observations may have several causes, the scientists said. The radio observations were made against a background of objects far beyond our own Milky Way Galaxy, while the Hubble observations used stars within our Galaxy as reference points. The more-distant objects provide a better, more stable, reference, the astronomers pointed out. The radio observations, they added, are immune to other possible sources of error as well.

Discovered in 1896, SS Cygni is a popular object for amateur astronomers. According to the American Association of Variable Star Observers, not a single outburst of SS Cygni has been missed since its discovery. It has been observed nearly half a million times, and its brightness variations carefully tracked, making it one of the most intensely studied astronomical objects of the past century.

Miller Jones worked with Gregory Sivakoff of the University of Alberta and the University of Virginia, Christian Knigge of the University of Southampton in the UK, Elmar Kording of Radboud University Nijmegen in the Netherlands, and Matthew Templeton and Elizabeth Waagen of the American Association of Variable Star Observers, headquartered in Cambridge, Mass. The researchers published their findings in the journal Science.

The National Radio Astronomy Observatory is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities, Inc.

Contacts and sources:
Dave Finley

National Radio Astronomy Observatory

Scientists Discovering New Uses for Tiny Carbon Nanotubes

2013-05-24T13:30:00.000-04:00

Adding ionic liquid to nanotube films could build smaller gadgets, and create more cost effective “Smart Windows” that darken in bright sun

The atom-sized world of carbon nanotubes holds great promise for a future demanding smaller and faster electronic components. Nanotubes are stronger than steel and smaller than any element of silicon-based electronics—the ubiquitous component of today’s electrical devices—and have better conductivity, which means they can potentially process information faster while using less energy.

Credit: Wikipedia

The challenge has been figuring out how to incorporate all those great properties into useful electronic devices. A new discovery by four scientists at the University of California, Riverside has brought us closer to the goal. They discovered that by adding ionic liquid—a kind of liquid salt—they can modify the optical transparency of single-walled carbon nanotube films in a controlled pattern.

“It was a discovery, not something we were looking for,” said Robert Haddon, director of UC Riverside’s Center for Nanoscale Science and Engineering. He has a joint appointment in the College of Natural and Agricultural Sciences and the Bourns College of Engineering.

Robert Haddon is the director of UC Riverside’s Center for Nanoscale Science and Engineering.

Credit: L. Duka

Scientists Feihu Wang, Mikhail Itkis and Elena Bekyarova worked with him to try to improve the electrical behavior of carbon nanotubes, and as part of their research they also looked at whether they could modulate the transparency of the films. An article about their findings was published online in April in Nature Photonics.

The scientists spent some time trying to affect the optical properties of carbon nanotube films with an electric field, with little success, said Itkis, a research scientist at the Center for Nanoscale Science and Engineering. “But when we applied a thin layer of an ionic liquid on top of the nanotube film we noticed that the change of transparency is amplified 100 times and that the change in transparency occurs in the vicinity of one of the electrodes, so we started studying what causes these drastic changes and how to create transparency in controlled patterns.”

An ionic liquid contains negative and positive ions which can interact with the nanotubes, dramatically influencing their ability to store an electrical charge. That increases or decreases their transparency, similar to the way that glasses darken in sunlight. By learning how to manipulate the transparency, scientists may be able to start incorporating nanotube films into products that now rely on slower or heavier components, such as metal oxide.

For instance, using nanotube films meshed with a film of ionic liquid, scientists could create more cost effective Smart Windows, that darken when it’s hot outside and become lighter when it’s cold.

“Smart Windows are a new industry that has been shown to save 50 percent of your energy costs,” said Itkis. “On a very hot day you can shade your window just by turning a switch, so you don’t have to use as much air conditioning. And on a winter day, you can make a window more transparent to let in more light.”

The scientists still need to study the economic viability of using nanotube film, but Bekyarova said one possible advantage would be that carbon nanotubes are ultra thin—about 1,000 times smaller than a single strand of hair—so you would need very little to cover a large area, such as the windows of a large building.

Itkis said nanotube films also hold great promise in building lighter and more compact analytical instruments such as spectrometers, which are used to analyze the properties of light.

In this application, a nanotube film with an array of electrodes can be used as an electrically configurable diffraction grating for an infrared spectrometer, allowing the wavelength of light to be scanned without moving parts.

Furthermore, by using addressable electrodes, the spatial pattern of the induced transparency in the nanotube film can be modified in a controlled way and used as an electrically configurable optical media for storage and transfer of information via patterns of light.

Carbon nanotubes have great potential, but there is still plenty of work to be done to make them useful in electronics and optoelectronics, Haddon said.

“The challenge is to harness their outstanding properties,” he said. “They won’t be available at Home Depot next week, but there is continuing progress in the field.”

Contacts and sources:
Iqbal Pittalwala
University of California - Riverside

Astronomers Measure The Elusive Extragalactic Background Light

2013-05-24T13:27:00.000-04:00

If all the light emitted by all galaxies in the observable universe at all wavelengths during all of cosmic history were known, it would clue astronomers about the entire history of galaxy formation and evolution, and provide insights to key aspects of the expansion history of the universe.

Alberto Domínguez is a a postdoctoral researcher in the Department of Physics and Astronomy at UC Riverside.

Credit: I. Pittalwala, UC Riverside.

But measuring this light — known as extragalactic background light (EBL) — is no simple task, complicated by the fact that Earth is lodged inside a bright solar system and the Milky Way, a very bright galaxy, making it enormously difficult for ground-based and space-based telescopes to reliably measure EBL. Furthermore, current galaxy surveys being used to estimate EBL could very well be missing information from faint galaxies and other sources.

Enter now a team of astronomers who have come up with a solution that ingeniously overcomes the technical challenges of measuring EBL. They propose in a paper published May 24 in The Astrophysical Journal that one answer to the problem of measuring EBL lies in measuring the attenuation — or weakening — of very high-energy gamma rays from distant "blazars," which are supermassive black holes in the centers of galaxies.

"The EBL only affects gamma-ray photons that are more energetic than approximately 30 GeV (a unit of energy equal to billion electron volts)," explained Alberto Domínguez, a postdoctoral researcher in the Department of Physics and Astronomy at the University of California, Riverside and the lead author of the research paper. "This gamma-ray attenuation occurs when high-energy gamma rays from the blazars hit EBL photons and produce electrons and positrons. By measuring the attenuation, we can get an estimate for the total EBL."

By applying their methodology to blazars located at different distances (or different ages of the universe), Domínguez and colleagues were able to measure EBL out to five billion years ago.

"Five billion years ago is the maximum distance we are able to probe with our current technology," Domínguez said. "Sure, there are blazars farther away, but we are not able to detect them because the high-energy gamma rays they are emitting are too attenuated by EBL when they get to us — so weakened that our instruments are not sensitive enough to detect them."

Domínguez explained that to estimate the EBL using the attenuation of gamma-rays emitted by a blazar in the local universe, light from the beginning of galaxy formation in the local universe until now is measured. But by using blazars at different distances, EBL evolution can be studied and characterized, and how it was built up over cosmic time can be better understood. This has now been achieved by the UCR-led team of astronomers.

Domínguez and colleagues used blazar observations from the Fermi Gamma-ray Space Telescope as well as a combination of simultaneously-made observations for the same blazars from NASA's X-ray satellites Swift and Rossi X-ray Timing Explorer. These satellites measure gamma-ray photons with low energy, the kind that are unattenuated by EBL. The measurements allowed the researchers to predict, using models of blazar photon emission, the unattenuated gamma-ray brightness at higher energies (more than 30 GeV). Then, they compared these predictions with detections made by ground-based atmospheric Čerenkov telescopes, which provide attenuated gamma-ray data.

"A comparison between the predicted unattenuated gamma-ray brightness at energies larger than 30 GeV, and the detected attenuated brightness at energies larger than 30 GeV by the Čerenkov telescopes allows us to estimate the cosmic gamma-ray horizon that is directly related to EBL attenuation," said Justin D. Finke at the U.S. Naval Research Laboratory in Wash., D.C., and a coauthor on the paper.

The researchers explained that measuring this horizon is important because it gives an estimate of EBL attenuation over distance/age of the universe, which is essential to understand the evolution of the EBL and, therefore, about the star-formation history of galaxies.

"Our achievement also will allow us to extract information about the properties of the universe, such as its expansion rate, using a novel technique based on our results," said Francisco Prada at the Institute of Theoretical Physics, Madrid, Spain, and a coauthor on the paper.

The researchers found that the attenuation of blazar gamma rays, as measured by the Čerenkov telescopes, is in agreement with the EBL expected from galaxies detected by current surveys (such as surveys made by GALEX, Hubble, and Spitzer telescopes) and from modeling the evolution of the galaxy population.

"This agreement shows that the sorts of galaxies we observed are indeed responsible for most of the light in the universe," Domínguez said. "In other words, the EBL contribution from faint galaxies and other sources should be very low."

Said Joel Primack, a professor of physics at the UC Santa Cruz, the director of the University of California High-Performance AstroComputing Center, and a coauthor on the paper, "This means that faint galaxies that will be detected by the next generation of infrared telescopes, such as the NASA James Webb Space Telescope, will not contribute significantly to the total EBL we see today."

The research paper can also be found on the public repository arXiv here.

Domínguez, Finke, Prada and Primack were joined in the study by Brian Siana, Domínguez's advisor, at UCR; F. S. Kitaura at Leibniz-Institut für Astrophysik, Germany; and D. Paneque at Stanford University, Calif.

The research was supported by grants from NASA; the U.S. National Science Foundation; the Ministerio de Ciencia e Innovación, Spain through the Multidark Consolider; the Istituto Nazionale di Astrofisica, Italy; and the National d'Études Spatiales, France. Additional support was provided by a Fermi Guest Investigator grant.

Contacts and sources:
Iqbal Pittalwala
University of California - Riverside

Detection Of The Cosmic Gamma Ray Horizon: Measures All The Light In The Universe Since The Big Bang

2013-05-24T13:24:00.000-04:00

How much light has been emitted by all galaxies since the cosmos began? After all, almost every photon (particle of light) from ultraviolet to far infrared wavelengths ever radiated by all galaxies that ever existed throughout cosmic history is still speeding through the Universe today.

If we could carefully measure the number and energy (wavelength) of all those photons—not only at the present time, but also back in time—we might learn important secrets about the nature and evolution of the Universe, including how similar or different ancient galaxies were compared to the galaxies we see today.

The attached figure illustrates how energetic gamma rays (dashed lines) from a distant blazar strike photons of extragalactic background light (wavy lines) and produce pairs of electrons and positrons. The energetic gamma rays that are not attenuated by this process strike the upper atmosphere, producing a cascade of charged particles which make a cone of Čerenkov light that is detected by the array of imaging atmospheric Čerenkov telescopes on the ground. A high-resolution version of this photograph is available here.

Credit: Nina McCurdy and Joel R. Primack/UC-HiPACC; Blazar: Frame from a conceptual animation of 3C 120 created by Wolfgang Steffen/UNAM

That bath of ancient and young photons suffusing the Universe today is called the extragalactic background light (EBL). An accurate measurement of the EBL is as fundamental to cosmology as measuring the heat radiation left over from the Big Bang (the cosmic microwave background) at radio wavelengths. A new paper, called "Detection of the Cosmic γ-Ray Horizon from Multiwavelength Observations of Blazars," by Alberto Dominguez and six coauthors, just published today by the Astrophysical Journal—based on observations spanning wavelengths from radio waves to very energetic gamma rays, obtained from several NASA spacecraft and several ground-based telescopes—describes the best measurement yet of the evolution of the EBL over the past 5 billion years.

Directly measuring the EBL by collecting its photons with a telescope, however, poses towering technical challenges—harder than trying to see the dim band of the Milky Way spanning the heavens at night from midtown Manhattan. Earth is inside a very bright galaxy with billions of stars and glowing gas. Indeed, Earth is inside a very bright solar system: sunlight scattered by all the dust in the plane of Earth's orbit creates the zodiacal light radiating across the optical spectrum down to long-wavelength infrared. Therefore ground-based and space-based telescopes have not succeeded in reliably measuring the EBL directly.

So, astrophysicists developed an ingenious work-around method: measuring the EBL indirectly through measuring the attenuation of—that is, the absorption of—very high energy gamma rays from distant blazars. Blazars are supermassive black holes in the centers of galaxies with brilliant jets directly pointed at us like a flashlight beam. Not all the high-energy gamma rays emitted by a blazar, however, make it all the way across billions of light-years to Earth; some strike a hapless EBL photon along the way. When a high-energy gamma ray photon from a blazar hits a much lower energy EBL photon, both are annihilated and produce two different particles: an electron and its antiparticle, a positron, which fly off into space and are never heard from again. Different energies of the highest-energy gamma rays are waylaid by different energies of EBL photons. Thus, measuring how much gamma rays of different energies are attenuated or weakened from blazars at different distances from Earth indirectly gives a measurement of how many EBL photons of different wavelengths exist along the line of sight from blazar to Earth over those different distances.

Observations of blazars by NASA's Fermi Gamma Ray Telescope spacecraft for the first time detected that gamma rays from distant blazars are indeed attenuated more than gamma rays from nearby blazars, a result announced on November 30, 2012, in a paper published in Science, as theoretically predicted.

Now, the big news—announced in today's Astrophysical Journal paper—is that the evolution of the EBL over the past 5 billion years has been measured for the first time. That's because looking farther out into the Universe corresponds to looking back in time. Thus, the gamma ray attenuation spectrum from farther distant blazars reveals how the EBL looked at earlier eras.

This was a multistep process. First, the coauthors compared the Fermi findings to intensity of X-rays from the same blazars measured by X-ray satellites Chandra, Swift, Rossi X-ray Timing Explorer, and XMM/Newton and lower-energy radiation measured by other spacecraft and ground-based observatories. From these measurements, Dominguez et al. were able to calculate the blazars' original emitted, unattenuated gamma-ray brightnesses at different energies.

The coauthors then compared those calculations of unattenuated gamma-ray flux at different energies with direct measurements from special ground-based telescopes of the actual gamma-ray flux received at Earth from those same blazars. When a high-energy gamma ray from a blazar strikes air molecules in the upper regions of Earth's atmosphere, it produces a cascade of charged subatomic particles. This cascade of particles travels faster than the speed of light in air (which is slower than the speed of light in a vacuum). This causes a visual analogue to a "sonic boom": bursts of a special light called Čerenkov radiation. This Čerenkov radiation was detected by imaging atmospheric Čerenkov telescopes (IACTs), such as HESS (High Energy Stereoscopic System) in Namibia, MAGIC (Major Atmospheric Gamma Imaging Čerenkov) in the Canary Islands, and VERITAS (Very Energetic Radiation Imaging Telescope Array Systems) in Arizona.

Comparing the calculations of the unattenuated gamma rays to actual measurements of the attenuation of gamma rays and X-rays from blazars at different distances allowed Dominquez et al. to quantify the evolution of the EBL—that is, to measure how the EBL changed over time as the Universe aged—out to about 5 billion years ago (corresponding to a redshift of about z = 0.5). "Five billion years ago is the maximum distance we are able to probe with our current technology," Domínguez said. "Sure, there are blazars farther away, but we are not able to detect them because the high-energy gamma rays they are emitting are too attenuated by EBL when they get to us—so weakened that our instruments are not sensitive enough to detect them." This measurement is the first statistically significant detection of the so-called "Cosmic Gamma Ray Horizon" as a function of gamma-ray energy. The Cosmic Gamma Ray Horizon is defined as the distance at which roughly one-third (or, more precisely, 1/e – that is, 1/2.718 – where e is the base of the natural logarithms) of the gamma rays of a particular energy have been attenuated.

This latest result confirms that the kinds of galaxies observed today are responsible for most of the EBL over all time. Moreover, it sets limits on possible contributions from many galaxies too faint to have been included in the galaxy surveys, or on possible contributions from hypothetical additional sources (such as the decay of hypothetical unknown elementary particles).

Contacts and sources:
Alberto Dominguez
University of California High-Performance AstroComputing Center

Why We Itch: Molecule That Causes Itching Sensation Identified

2013-05-24T13:15:00.001-04:00

Scientists at the National Institutes of Health report they have discovered in mouse studies that a small molecule released in the spinal cord triggers a process that is later experienced in the brain as the sensation of itch.

The small molecule, called natriuretic polypeptide b (Nppb), streams ahead and selectively plugs into a specific nerve cell in the spinal cord, which sends the signal onward through the central nervous system. When Nppb or its nerve cell was removed, mice stopped scratching at a broad array of itch-inducing substances. The signal wasn’t going through.

Because the nervous systems of mice and humans are similar, the scientists say a comparable biocircuit for itch likely is present in people. If correct, this start switch would provide a natural place to look for unique molecules that can be targeted with drugs to turn off the sensation more efficiently in the millions of people with chronic itch conditions, such eczema and psoriasis.

The paper, published online in the journal Science, also helps to solve a lingering scientific issue. “Our work shows that itch, once thought to be a low-level form of pain, is a distinct sensation that is uniquely hardwired into the nervous system with the biochemical equivalent of its own dedicated land line to the brain,” said Mark Hoon, Ph.D., the senior author on the paper and a scientist at the National Institute of Dental and Craniofacial Research, part of the National Institutes of Health.

Hoon said his group’s findings began with searching for the signaling components on a class of nerve cells, or neurons, that contain a molecule called TRPV1. These neurons, with their long nerve fibers extending into the skin, muscle, and other tissues, help to monitor a range of external conditions, from extreme temperature changes to detecting pain.

Yet little is known about how these neurons recognize the various sensory inputs and, like sorting mail, know how to route them correctly to the appropriate pathway to the brain.

To fill in more of the details, Hoon said his laboratory identified in mice some of the main neurotransmitters that TRPV1 neurons produce. A neurotransmitter is a small molecule that neurons selectively release when stimulated, like a quick pulse of water from a faucet, to communicate sensory signals to other nerve cells.

The scientists screened the various neurotransmitters, including Nppb, to see which ones corresponded with transmitting sensation.

“We tested Nppb for its possible role in various sensations without success,” said Santosh Mishra, lead author on the study and a researcher in the Hoon laboratory. “When we exposed the Nppb-deficient mice to several itch-inducing substances, it was amazing to watch. Nothing happened. The mice wouldn’t scratch.”

Further experiments established that Nppb was essential to initiate the sensation of itch, known clinically as pruritus. Equally significant, the molecule was necessary to respond to a broad spectrum of pruritic substances. Previous research had suggested that a common start switch for itch would be unlikely, given the myriad proteins and cell types that seemed to be involved in processing the sensation.

Hoon and Mishra turned to the dorsal horn, a junction point in the spine where sensory signals from the body’s periphery are routed onward to the brain. Within this nexus of nerve connections, they looked for cells that expressed the receptor to receive the incoming Nppb molecules.

“The receptors were exactly in the right place in the dorsal horn,” said Hoon, the receptor being the long-recognized protein Npra. “We went further and removed the Npra neurons from the spinal cord. We wanted to see if their removal would short-circuit the itch, and it did.”

Hoon said this experiment added another key piece of information. Removing the receptor neurons had no impact on other sensory sensations, such as temperature, pain, and touch. This told them that the connection forms a dedicated biocircuit to the brain that conveys the sensation of itch.

But the scientists had stepped into a conundrum. Previous reports had suggested that another neurotransmitter called GRP might initiate itch. If that wasn’t the case, where did GRP fit into the process?

They tested the receptor neurons that express GRP, finding the previous reports were correct about this molecule relaying the signal to the central nervous system. GRP just enters the picture after Nppb already has set the sensation in motion.

Based on these findings, Nppb would seem to be an obvious first target to control itch. But that’s not necessarily the case. Nppb also is used in the heart, kidneys, and other parts of the body, so attempts to control the neurotransmitter in the spine has the potential to cause unwanted side effects.

“The larger scientific point remains,” said Hoon. “We have defined in the mouse the primary itch-initiating neurons and figured out the first three steps in the pruritic pathway. Now the challenge is to find similar biocircuitry in people, evaluate what’s there, and identify unique molecules that can be targeted to turn off chronic itch without causing unwanted side effects. So, this is a start, not a finish.”

The paper, published May 10 online in Science, is titled The Cells and Circuitry for Itch Responses in Mice. The authors are Santosh K. Mishra and Mark A. Hoon.
The National Institute of Dental and Craniofacial Research (NIDCR) is the Nation’s leading funder of research on oral, dental, and craniofacial health. To learn more about NIDCR, please visit: www.nidcr.nih.gov

About the National Institutes of Health (NIH): NIH, the nation's medical research agency, includes 27 Institutes and Centers and is a component of the U.S. Department of Health and Human Services. NIH is the primary federal agency conducting and supporting basic, clinical, and translational medical research, and is investigating the causes, treatments, and cures for both common and rare diseases. For more information about NIH and its programs, visit www.nih.gov.
Contacts and sources:
Bob Kuska
NIH

Monkey Teeth Help Reveal Neanderthal Weaning

2013-05-24T13:11:00.000-04:00

Most modern human mothers wean their babies much earlier than our closest primate relatives. But what about our extinct relatives, the Neanderthals?

A team of U.S. and Australian researchers reports in the journal Nature May 22 that they can now use fossil teeth to calculate when a Neanderthal baby was weaned. The new technique is based in part on knowledge gained from studies of teeth from human infants and from monkeys at the California National Primate Research Center at the University of California, Davis.

This molar tooth model with the cut face shows color-coded barium patterns merging with a microscopic map of growth lines.

Credit: Ian Harrowell, Christine Austin and Manish Arora/graphic

Using the new technique, the researchers concluded that at least one Neanderthal baby was weaned at much the same age as most modern humans.

Just as tree rings record the environment in which a tree grew, traces of barium in the layers of a primate tooth can tell the story of when an infant was exclusively milk-fed, when supplemental food started, and at what age it was weaned, said Katie Hinde, professor of human evolutionary biology at Harvard University and an affiliate scientist at the UC Davis Primate Center. Hinde directs the Comparative Lactation Laboratory at Harvard and has conducted a three-year study of lactation, weaning and behavior among rhesus macaques at UC Davis.

The team was able to determine exact timing of birth, when the infant was fed exclusively on mother’s milk, and the weaning process, from mineral traces in teeth. By studying monkey teeth and comparing them to center records, they could show that the technique was accurate almost to the day.

After validating the technique with monkeys, the scientists applied it to human teeth and a Neanderthal tooth. They found that the Neanderthal baby was fed exclusively on mother’s milk for seven months, followed by seven months of supplementation — a similar pattern to present-day humans. The technique opens up extensive opportunities to further investigate lactation in fossils and museum collections of primate teeth.

Although there is some variation among human cultures, the accelerated transition to foods other than mother’s milk is thought to have emerged in our ancestral history due, in part, to more cooperative infant care and access to a more nutritious diet, Hinde said. Shorter lactation periods could mean shorter gaps between pregnancies and a higher rate of reproduction. However, there has been much debate about when our ancestors evolved accelerated weaning.

For the past few decades researchers have relied on tooth eruption age as a direct proxy for weaning age. Yet recent investigations of wild chimpanzees have shown that the first molar eruption occurs toward the end of weaning.

"By applying these new techniques to primate teeth in museum collections, we can more precisely assess maternal investment across individuals within species, as well as life history evolution among species," Hinde said.

Authors in addition to Hinde were: Christine Austin and Manish Arora, Icahn School of Medicine at Mount Sinai, New York, Harvard School of Public Health, and University of Sydney, Australia; Tanya Smith, Harvard University; Asa Bradman and Brenda Eskenazi, UC Berkeley; Renaud Joannes-Boyau, Southern Cross University, Lismore, Australia; David Bishop, Dominic Hare and Philip Doble, University of Technology Sydney, Australia.

The work was funded by the U.S. Environmental Protection Agency, U.S. National Institute of Environmental Health Sciences, U.S. National Science Foundation, Australian National Health and Medical Research Council, Australian Research Council and Harvard University.
About UC Davis

For more than 100 years, UC Davis has engaged in teaching, research and public service that matter to California and transform the world. Located close to the state capital, UC Davis has more than 33,000 students, more than 2,500 faculty and more than 21,000 staff, an annual research budget of nearly $750 million, a comprehensive health system and 13 specialized research centers. The university offers interdisciplinary graduate study and more than 100 undergraduate majors in four colleges — Agricultural and Environmental Sciences, Biological Sciences, Engineering, and Letters and Science. It also houses six professional schools — Education, Law, Management, Medicine, Veterinary Medicine and the Betty Irene Moore School of Nursing.

Contacts and sources:

UC Davis

Universe Older And Expanding More Slowly Than Previously Thought

2013-05-24T13:08:00.001-04:00

The Planck space mission has released the most accurate and detailed map ever made of the oldest light in the universe. The universe according to Planck is expanding a bit more slowly than thought, and at 13.8 billion is 100 million years older than previously estimated. There is a bit less dark energy and a bit more of both normal and dark matter in the universe — although the nature of dark energy and dark matter remain mysterious.

The Planck Space Observatory

Credit: ESA and the Planck collaboration

“Planck’s high-precision map of the oldest light in our universe allows us to extract the most refined values yet of the universe’s ingredients,” said Lloyd Knox, a physics professor at UC Davis and the leader of the U.S. team determining these ingredients from the Planck data. UC Davis graduate student Marius Millea and postdoctoral scholar Zhen Hou also worked with Knox on the analysis.

This May, UC Davis will host back-to-back conferences on “Mining the Cosmic Frontier in the Planck Era” (May 20-22) and “Fundamental Questions in Cosmology” (May 22-24). These will be the first major meetings in the U.S. for researchers to discuss the new data.

Planck is a European Space Agency mission with collaboration from NASA. It was launched in 2009 to a point almost a million miles from Earth where it can look into deep space and map tiny differences in the cosmic microwave background, the faint glow of radiation left over from just after the big bang.

Planck map of the cosmic microwave background shows tiny fluctuations in temperature, which correspond to regions of different densities: denser regions eventually coalesced into today’s galaxies and stars.

Credit: ESA and the Planck collaboration

For the first 370,000 years of the universe’s existence, light was trapped inside a hot plasma, unable to travel far without bouncing off electrons. Eventually the plasma cooled enough for light particles (photons) to escape, creating the patterns of the cosmic microwave background. The patterns of light represent the seeds of galaxies and clusters of galaxies we see around us today.

Then these photons traveled through space for billions of years, making their way past stars and galaxies, before falling into Planck’s detectors. The gravitational pull of both galaxies and clumps of dark matter pulls photons onto new courses, an effect called “gravitational lensing.”

“Our microwave background maps are now sufficiently sensitive that we can use them to infer a map of the dark matter that has gravitationally-lensed the microwave photons,” Knox said. “This is the first all-sky map of the large-scale mass distribution in the Universe.”

The Planck observatory has produced the most detailed map to date of mass distribution in the universe.

Credit: ESA and the Planck collaboration

These new data from Planck have allowed scientists to test and improve the accuracy of the standard model of cosmology, which describes the age and contents of our universe.

Based on the new map, the Planck team estimates that the expansion rate of the universe, known as Hubble’s constant, is 67.15 plus or minus 1.2 kilometers/second/megaparsec. (A megaparsec is roughly 3 million light-years.) That’s less than prior estimates derived from space telescopes, such as NASA’s Spitzer and Hubble.

The new estimate of dark matter content in the universe is 26.8 percent, up from 24 percent, while dark energy falls to 68.3 percent, down from 71.4 percent. Normal matter now is 4.9 percent, up from 4.6 percent.

At the same time, some curious features are observed that don’t quite fit with the current model. For example, the model assumes the sky is the same everywhere, but the light patterns are asymmetrical on two halves of the sky, and there is larger-than-expected cold spot extending over a patch of sky.

“On one hand, we have a simple model that fits our observations extremely well, but on the other hand, we see some strange features which force us to rethink some of our basic assumptions,” said Jan Tauber, the European Space Agency’s Planck project scientist based in the Netherlands.

Scientists can also use the new map to test theories about cosmic inflation, a dramatic expansion of the universe that occurred immediately after its birth. In far less time than it takes to blink an eye, the universe blew up by 100 trillion trillion times in size. The new map, by showing that matter seems to be distributed randomly, suggests that random processes were at play in the very early universe on minute “quantum” scales. This allows scientists to rule out many complex inflation theories in favor of simple ones.

“Patterns over huge patches of sky tell us about what was happening on the tiniest of scales in the moments just after our universe was born,” said Charles Lawrence, the U.S. project scientist for Planck at NASA’s Jet Propulsion Laboratory (JPL) in Pasadena, Calif.

Planck is the successor to balloon-based and space missions that helped astronomers learn a great deal from the microwave background, including NASA’s Wilkinson Microwave Anisotropy Probe (WMAP) and the Cosmic Background Explorer (COBE), which earned the 2006 Nobel Prize in Physics. Complete results from Planck, which still is scanning the skies, will be released in 2014.

Contacts and sources:

UC Davis

– NASA: http://www.nasa.gov/planck

– ESA: http://www.esa.int/Our_Activities/Space_Science/Planck

The Ascent Of Man: Why Our Early Ancestors Took To Two Feet

2013-05-24T12:55:00.002-04:00

A new study by archaeologists at the University of York challenges evolutionary theories behind the development of our earliest ancestors from tree dwelling quadrupeds to upright bipeds capable of walking and scrambling.

The researchers say our upright gait may have its origins in the rugged landscape of East and South Africa which was shaped during the Pliocene epoch by volcanoes and shifting tectonic plates.

Credit: Antiquity.

Hominins, our early forebears, would have been attracted to the terrain of rocky outcrops and gorges because it offered shelter and opportunities to trap prey. But it also required more upright scrambling and climbing gaits, prompting the emergence of bipedalism.

The York research challenges traditional hypotheses which suggest our early forebears were forced out of the trees and onto two feet when climate change reduced tree cover.

The study, ‘Complex Topography and Human Evolution: the Missing Link’, was developed in conjunction with researchers from the Institut de Physique du Globe in Paris. It is published in the journal Antiquity.

Dr Isabelle Winder, from the Department of Archaeology at York and one of the paper’s authors, said: “Our research shows that bipedalism may have developed as a response to the terrain, rather than a response to climatically-driven vegetation changes.

“The broken, disrupted terrain offered benefits for hominins in terms of security and food, but it also proved a motivation to improve their locomotor skills by climbing, balancing, scrambling and moving swiftly over broken ground - types of movement encouraging a more upright gait.”

The research suggests that the hands and arms of upright hominins were then left free to develop increased manual dexterity and tool use, supporting a further key stage in the evolutionary story.

The development of running adaptations to the skeleton and foot may have resulted from later excursions onto the surrounding flat plains in search of prey and new home ranges.

Dr Winder said: “The varied terrain may also have contributed to improved cognitive skills such as navigation and communication abilities, accounting for the continued evolution of our brains and social functions such as co-operation and team work.

“Our hypothesis offers a new, viable alternative to traditional vegetation or climate change hypotheses. It explains all the key processes in hominin evolution and offers a more convincing scenario than traditional hypotheses.”

Contacts and sources:
University of York

The paper: ‘Complex Topography and Human Evolution: the Missing Link’ is published in Antiquity at antiquity.ac.uk/journal.html

The Ring Nebula's True Shape Revealed

2013-05-23T15:19:00.001-04:00

The distinctive shape of the Ring Nebula, the glowing shroud around a dying Sun-like star, makes it a popular celestial object that appears in many astronomy books. New observations of the Ring Nebula by NASA's Hubble Space Telescope, however, reveal a new twist on an iconic nebula.

The Hubble images offer the best view yet of the nebula, revealing a complex structure. The observations have allowed astronomers to construct the most precise three-dimensional model of the glowing gas shroud, called a planetary nebula. Based on the new observations, the Hubble research team suggests that the ring wraps around a blue football-shaped structure that protrudes out of opposite sides of the ring. The nebula is tilted toward Earth so that astronomers see the ring face-on.

The Ring Nebula's distinctive shape makes it a popular illustration for astronomy books. But new observations by NASA's Hubble Space Telescope of the glowing gas shroud around an old, dying, sun-like star reveal a new twist.

"The nebula is not like a bagel, but rather, it's like a jelly doughnut, because it's filled with material in the middle," said C. Robert O'Dell of Vanderbilt University in Nashville, Tenn. He leads a research team that used Hubble and several ground-based telescopes to obtain the best view yet of the iconic nebula. The images show a more complex structure than astronomers once thought and have allowed them to construct the most precise 3-D model of the nebula.

"With Hubble's detail, we see a completely different shape than what's been thought about historically for this classic nebula," O'Dell said. "The new Hubble observations show the nebula in much clearer detail, and we see things are not as simple as we previously thought."

The Ring Nebula is about 2,000 light-years from Earth and measures roughly 1 light-year across. Located in the constellation Lyra, the nebula is a popular target for amateur astronomers.

Previous observations by several telescopes had detected the gaseous material in the ring's central region. But the new view by Hubble's sharp-eyed Wide Field Camera 3 shows the nebula's structure in more detail. O'Dell's team suggests the ring wraps around a blue, football-shaped structure. Each end of the structure protrudes out of opposite sides of the ring.

The nebula is tilted toward Earth so that astronomers see the ring face-on. In the Hubble image, the blue structure is the glow of helium. Radiation from the white dwarf star, the white dot in the center of the ring, is exciting the helium to glow. The white dwarf is the stellar remnant of a sun-like star that has exhausted its hydrogen fuel and has shed its outer layers of gas to gravitationally collapse to a compact object.

This video begins with a zoom into the constellation Lyra to the location of the Ring Nebula and the new image from the Hubble Space Telescope and the Large Binocular Telescope. Then the three-dimensional model of the Ring Nebula, developed from the new observations, is explored. The main ring glows in the light of nitrogen, shown in red. That ring is filled with oxygen emission, shown in green. Perpendicular lobes are filled with the hottest emission from helium, shown in blue. Dense dark knots line the interior of the ring, and their shadows glow like spikes in hydrogen emission, shown in red. Hydrogen emission also reveals the inner and outer halos. A circuit around the 3D model showcases the more accurate and more detailed structure astronomers have uncovered.

Credit: NASA, ESA, and G. Bacon, F. Summers, and Mary Estacion (STScI)

O'Dell's team was surprised at the detailed Hubble views of the dark, irregular knots of dense gas embedded along the inner rim of the ring, which look like spokes in a bicycle wheel. These gaseous tentacles formed when expanding hot gas pushed into cool gas ejected previously by the doomed star. The knots are more resistant to erosion by the wave of ultraviolet light unleashed by the star. The Hubble images have allowed the team to match up the knots with the spikes of light around the bright, main ring, which are a shadow effect. Astronomers have found similar knots in other planetary nebulae.

All of this gas was expelled by the central star about 4,000 years ago. The original star was several times more massive than our sun. After billions of years converting hydrogen to helium in its core, the star began to run out of fuel. It then ballooned in size, becoming a red giant. During this phase, the star shed its outer gaseous layers into space and began to collapse as fusion reactions began to die out. A gusher of ultraviolet light from the dying star energized the gas, making it glow.

This video begins with a zoom into the constellation Lyra to the location of the Ring Nebula and the new image from the Hubble Space Telescope and the Large Binocular Telescope. The view cross-fades to a three-dimensional model of the Ring Nebula that was developed from the new observations. A circuit around the 3D model showcases the main ring structure, the perpendicular lobes, the spike-like emission in the shadows of dense knots, and the halos surrounding the nebula.

Credit: NASA, ESA, and G. Bacon, F. Summers, and Mary Estacion (STScI)

The outer rings were formed when faster-moving gas slammed into slower-moving material. The nebula is expanding at more than 43,000 miles an hour, but the center is moving faster than the expansion of the main ring. O'Dell's team measured the nebula's expansion by comparing the new Hubble observations with Hubble studies made in 1998.

The Ring Nebula will continue to expand for another 10,000 years, a short phase in the lifetime of the star. The nebula will become fainter and fainter until it merges with the interstellar medium.

Studying the Ring Nebula's fate will provide insight into the sun's demise in another 6 billion years. The sun is less massive than the Ring Nebula's progenitor star, so it will not have an opulent ending.

"When the sun becomes a white dwarf, it will heat more slowly after it ejects its outer gaseous layers," O'Dell said. "The material will be farther away once it becomes hot enough to illuminate the gas. This larger distance means the sun's nebula will be fainter because it is more extended."

In the analysis, the research team also obtained images from the Large Binocular Telescope at the Mount Graham International Observatory in Arizona and spectroscopic data from the San Pedro Martir Observatory in Baja California, Mexico.

Contacts and sources:
J.D. Harrington
NASA Headquarters, Washington

Ray Villard
Space Telescope Science Institute, Baltimore, Md.

Clues To Possible Life On Mars Revealed By Bacterium From Canadian High Arctic

2013-05-23T14:37:00.002-04:00

The temperature in the permafrost on Ellesmere Island in the Canadian high Arctic is nearly as cold as that of the surface of Mars. So the recent discovery by a McGill University led team of scientists of a bacterium that is able to thrive at –15ºC, the coldest temperature ever reported for bacterial growth, is exciting. The bacterium offers clues about some of the necessary preconditions for microbial life on both the Saturn moon Enceladus and Mars, where similar briny subzero conditions are thought to exist.

Credit: McGill University

The team of researchers, led by Prof. Lyle Whyte and postdoctoral fellow Nadia Mykytczuk, both from the Dept. of Natural Resource Sciences at McGill University, discovered Planococcus halocryophilus OR1 after screening about 200 separate High Arctic microbes looking for the microorganism best adapted to the harsh conditions of the Arctic permafrost. ”We believe that this bacterium lives in very thin veins of very salty water found within the frozen permafrost on Ellesmere Island,” explains Whyte. “The salt in the permafrost brine veins keeps the water from freezing at the ambient permafrost temperature (~-16ºC), creating a habitable but very harsh environment. It’s not the easiest place to survive but this organism is capable of remaining active (i.e. breathing) to at least -25ºC in permafrost.”

In order to understand what it takes to be able to do so, Mykytczuk, Whyte and their colleagues studied the genomic sequence and other molecular traits of P. halocryophilus OR1. The researchers found that the bacterium adapts to the extremely cold, salty conditions in which it is found thanks to significant modifications in its cell structure and function and increased amounts of cold-adapted proteins. These include changes to the membranes that envelop the bacterium and protect it from the hostile environment in which it lives.

The genome sequence also revealed that this permafrost microbe is unusual in other ways. It appears to maintain high levels of compounds inside the bacterial cell that act as a sort of molecular antifreeze, keeping the microbe from freezing solid, while at the same time protecting the cell from the very salty exterior environment.

The researchers believe however, that such microbes may potentially play a harmful role in extremely cold environments such as the High Arctic by increasing carbon dioxide emissions from the melting permafrost, one of the results of global warming.

Whyte is delighted with the discovery and says with a laugh, “I’m kind of proud of this bug. It comes from the Canadian High Arctic and is our cold temperature champion, but what we can learn from this microbe may tell us a lot about how similar microbial life may exist elsewhere in the solar system.”

This research was funded by: Natural Sciences and Engineering Research Council of Canada CREATE Canadian Astrobiology Training Program, Canadian Space Agency, the Polar Continental Shelf Program, Canada Research Chairs Program, and the Canada Foundation for Innovation.

Contacts and sources:
Katherine Gombay
McGill University

Hidden Population of Exotic Neutron Stars

2013-05-23T14:25:00.002-04:00

Magnetars – the dense remains of dead stars that erupt sporadically with bursts of high-energy radiation - are some of the most extreme objects known in the Universe. A major campaign using NASA's Chandra X-ray Observatory and several other satellites shows magnetars may be more diverse - and common - than previously thought.

The magnetar called SGR 0418+5729 (SGR 0418 for short) has been shown to have the lowest surface magnetic field ever found for this type of neutron star. Magnetars have surface magnetic fields that are usually ten to a thousand times stronger than SGR 0418's.

Data from Chandra, XMM-Newton, Swift and RXTE was used to measure the surface magnetic field.These results have implications for understanding supernova explosions and the number and evolution of magnetars.

Graphic shows a magnetar called SGR 0418+5729 (SGR 0418 for short), a type of neutron star that has a relatively slow spin rate and generates occasional large blasts of X-rays.

Credit: X-ray: NASA/CXC/CSIC-IEEC/N.Rea et al; Optical: Isaac Newton Group of Telescopes, La Palma/WHT; Infrared: NASA/JPL-Caltech

When a massive star runs out of fuel, its core collapses to form a neutron star, an ultradense object about 10 to 15 miles wide. The gravitational energy released in this process blows the outer layers away in a supernova explosion and leaves the neutron star behind.

Most neutron stars are spinning rapidly - a few times a second - but a small fraction have a relatively low spin rate of once every few seconds, while generating occasional large blasts of X-rays. Because the only plausible source for the energy emitted in these outbursts is the magnetic energy stored in the star, these objects are called "magnetars."

Most magnetars have extremely high magnetic fields on their surface that are ten to a thousand times stronger than for the average neutron star. New observations show that the magnetar known as SGR 0418+5729 (SGR 0418 for short) doesn’t fit that pattern. It has a surface magnetic field similar to that of mainstream neutron stars.

X-ray Image of SGR 0418+5729

Credit: Chandra X-ray Center

"We have found that SGR 0418 has a much lower surface magnetic field than any other magnetar," said Nanda Rea of the Institute of Space Science in Barcelona, Spain. "This has important consequences for how we think neutron stars evolve in time, and for our understanding of supernova explosions."

The researchers monitored SGR 0418 for over three years using Chandra, ESA's XMM-Newton as well as NASA's Swift and RXTE satellites. They were able to make an accurate estimate of the strength of the external magnetic field by measuring how its rotation speed changes during an X-ray outburst. These outbursts are likely caused by fractures in the crust of the neutron star precipitated by the buildup of stress in a relatively strong, wound-up magnetic field lurking just beneath the surface.

"This low surface magnetic field makes this object an anomaly among anomalies," said co-author GianLuca Israel of the National Institute of Astrophysics in Rome. "A magnetar is different from typical neutron stars, but SGR 0418 is different from other magnetars as well."

By modeling the evolution of the cooling of the neutron star and its crust, as well as the gradual decay of its magnetic field, the researchers estimated that SGR 0418 is about 550,000 years old. This makes SGR 0418 older than most other magnetars, and this extended lifetime has probably allowed the surface magnetic field strength to decline over time. Because the crust weakened and the interior magnetic field is relatively strong, outbursts could still occur.

The case of SGR 0418 may mean that there are many more elderly magnetars with strong magnetic fields hidden under the surface, implying that their birth rate is five to ten times higher than previously thought.

"We think that about once a year in every galaxy a quiet neutron star should turn on with magnetar-like outbursts, according to our model for SGR 0418," said Josè Pons of the University of Alacant in Spain. "We hope to find many more of these objects."

Another implication of the model is that the surface magnetic field of SGR 0418 should have once been very strong at its birth a half million years ago. This, plus a possibly large population of similar objects, could mean that the massive progenitor stars already had strong magnetic fields, or these fields were created by rapidly rotating neutron stars in the core collapse that was part of the supernova event.

If large numbers of neutron stars are born with strong magnetic fields then a significant fraction of gamma-ray bursts might be caused by the formation of magnetars rather than black holes. Also, the contribution of magnetar births to gravitational wave signals – ripples in space-time – would be larger than previously thought.

The possibility of a relatively low surface magnetic field for SGR 0418 was first announced in 2010 by a team with some of the same members. However, the scientists at that time could only determine an upper limit for the magnetic field and not an actual estimate because not enough data had been collected.

SGR 0418 is located in the Milky Way galaxy at a distance of about 6,500 light years from Earth. These new results on SGR 0418 appear online and will be published in the June 10, 2013 issue of The Astrophysical Journal. NASA's Marshall Space Flight Center in Huntsville, Ala., manages the Chandra program for NASA's Science Mission Directorate in Washington. The Smithsonian Astrophysical Observatory controls Chandra's science and flight operations from Cambridge, Mass.

Contacts and sources:
Megan Watzke
Chandra X-ray Center

Milky Way Black Hole Snacks on Hot Gas

2013-05-23T11:22:00.002-04:00

This artist's concept illustrates the frenzied activity at the core of our Milky Way galaxy. The galactic center hosts a supermassive black hole in the region known as Sagittarius A*, or Sgr A*, with a mass of about four million times that of our sun.

Image credit: ESA–C. Carreau

"The black hole appears to be devouring the gas," said Paul Goldsmith, the U.S. project scientist for Herschel at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "This will teach us about how supermassive black holes grow."

Our galaxy's black hole is located in a region known as Sagittarius A* -- or Sgr A* for short -- which is a nearby source of radio waves. The black hole has a mass about four million times that of our sun and lies roughly 26,000 light-years away from our solar system.

Even at that distance, it is a few hundred times closer to us than any other galaxy with an active black hole at its center, making it the ideal natural laboratory to study the environment around these enigmatic objects. At Herschel's far-infrared wavelengths, scientists can peer through the dust in our galaxy and study the turbulent innermost region of the galaxy in great detail.

The biggest surprise was the hot gas in the innermost central region of the galaxy. At least some of it is 1,832 degrees Fahrenheit (around 1,000 degrees Celsius), much hotter than typical interstellar clouds, which are usually only a few tens of degrees above absolute zero, or minus 460 degrees Fahrenheit (minus 273 degrees Celsius).

Molecules on the menu at the Milky Way’s black hole

Credit: ESA

The team hypothesizes that emissions from strong shocks in highly magnetized gas in the region may be a significant contributor to the high temperatures. Such shocks can be generated in collisions between gas clouds, or in material flowing at high speeds.

Using near-infrared observations, other astronomers have spotted a separate, compact cloud of gas amounting to just a few Earth masses spiralling toward the black hole. Located much closer to the black hole than the reservoir of material studied by Herschel in this work, it may finally be gobbled up later this year.

Spacecraft, including NASA's Nuclear Spectroscopic Telescope Array (NuSTAR) and the Chandra X-ray Observatory, will be waiting to spot any X-ray burps as the black hole enjoys its feast.

Herschel is a European Space Agency mission, with science instruments provided by consortia of European institutes and with important participation by NASA. NASA's Herschel Project Office is based at NASA's Jet Propulsion Laboratory, Pasadena, Calif. JPL contributed mission-enabling technology for two of Herschel's three science instruments. The NASA Herschel Science Center, part of the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena, supports the United States astronomical community. Caltech manages JPL for NASA.

Contacts and sources:
Whitney Clavin
Jet Propulsion Laboratory, Pasadena

ESA

Mega Merger of Galaxies

2013-05-23T11:13:00.002-04:00

A massive and rare merging of two galaxies has been spotted in images taken by the Herschel space observatory, a European Space Agency mission with important NASA participation.

The Herschel Space Observatory first spotted the colliding duo in images taken with longer-wavelength infrared light, as shown in the image at left. Follow-up observations from many telescopes helped determine the extreme degree of star-formation taking place in the merger, as well as its incredible mass.

The image at right shows a close-up view, with the merging galaxies circled. The red data are from the Smithsonian Astrophysical Observatory's Submillimeter Array atop Mauna Kea, Hawaii, and show dust-enshrouded regions of star formation. The green data, taken by the National Radio Astronomy Observatory's Very Large Array, near Socorro, N.M., show carbon monoxide gas in the galaxies. In addition, the blue shows starlight.

The blue blobs outside of the circle are galaxies located much closer to us. These near-infrared light observations are from NASA's Hubble Space Telescope and the W.M. Keck Observatory atop Mauna Kea, Hawaii.

Image credit: ESA/NASA/JPL-Caltech/UC Irvine/STScI/Keck/NRAO/SAO

Follow-up studies by several telescopes on the ground and in space, including NASA's Hubble Space Telescope and Spitzer Space Telescope, tell a tale of two faraway galaxies intertwined and furiously making stars. Eventually, the duo will settle down to form one super-giant elliptical galaxy.

The findings help explain a mystery in astronomy. Back when our universe was 3 billion to 4 billion years old, it was populated with large reddish elliptical-shaped galaxies made up of old stars. Scientists have wondered whether those galaxies built up slowly over time through the acquisitions of smaller galaxies, or formed more rapidly through powerful collisions between two large galaxies.

The new findings suggest massive mergers are responsible for the giant elliptical galaxies.

"We're looking at a younger phase in the life of these galaxies -- an adolescent burst of activity that won't last very long," said Hai Fu of the University of California at Irvine, who is lead author of a new study describing the results. The study is published in the May 22 online issue of Nature.

This simulation shows the merging of two massive galaxies, sped up to cover 1.5 billion years of time. The merging galaxies are split into two views: a visible-light view is on the left, in which blue shows young stars and red indicates older stars and dust. The view at right shows emission from dust, which is what infrared telescopes like the Herschel Space Observatory see. When the galaxies finally merge, the strong burst of star formation can be seen best in infrared views.

Image credit: ESA/NASA/JPL-Caltech/UC Irvine/STScI/Keck/NRAO/SAO

"These merging galaxies are bursting with new stars and completely hidden by dust," said co-author Asantha Cooray, also of the University of California at Irvine. "Without Herschel's far-infrared detectors, we wouldn't have been able to see through the dust to the action taking place behind."

Herschel, which operated for almost four years, was designed to see the longest-wavelength infrared light. As expected, it recently ran out of the liquid coolant needed to chill its delicate infrared instruments. While its mission in space is over, astronomers still are scrutinizing the data, and further discoveries are expected.

In the new study, Herschel was used to spot the colliding galaxies, called HXMM01, located about 11 billion light-years from Earth, during a time when our universe was about 3 billion years old. At first, astronomers thought the two galaxies were just warped, mirror images of one galaxy. Such lensed galaxies are fairly common in astronomy and occur when the gravity from a foreground galaxy bends the light from a more distant object. After a thorough investigation, the team realized they were actually looking at a massive galaxy merger.

Follow-up characterization revealed the duo is churning out the equivalent of 2,000 stars a year. By comparison, our Milky Way hatches about two to three stars a year. The total number of stars in both colliding galaxies averages out to about 400 billion.

Mergers are fairly common in the cosmos, but this particular event is more unusual because of the prolific amounts of gas and star formation, and the sheer size of the merger at such a distant epoch.

The results go against the more popular model explaining how the biggest galaxies arise: through minor acquisitions of small galaxies. Instead, mega smash-ups may be doing the job.

Contacts and sources:

NASA

ESA

Scientists Announce Top 10 New Species

2013-05-23T09:33:00.002-04:00

An amazing glow-in-the-dark cockroach, a harp-shaped carnivorous sponge and the smallest vertebrate on Earth are just three of the newly discovered top 10 species selected by the International Institute for Species Exploration at Arizona State University. A global committee of taxonomists — scientists responsible for species exploration and classification — announced its list of top 10 species from 2012 today, May 23.

The announcement, now in its sixth year, coincides with the anniversary of the birth of Carolus Linnaeus — the 18th century Swedish botanist responsible for the modern system of scientific names and classifications.

The top 10 new species list was announced May 23 by the International Institute for Species Exploration at Arizona State University. The 2013 list includes an amazing glow-in-the-dark cockroach, a harp-shaped carnivorous sponge, and the smallest vertebrate on Earth -- a tiny frog. It also includes a snail-eating false coral snake, flowering bushes, a green lacewing, a hangingfly fossil, a monkey with a blue-colored behind and human-like eyes, a tiny violet and a black staining fungus.

Credit: Composite: Jacob Sahertian

Also slithering it way onto this year's top 10 is a snail-eating false coral snake, as well as flowering bushes from a disappearing forest in Madagascar, a green lacewing that was discovered through social media and hangingflies that perfectly mimicked ginkgo tree leaves 165 million years ago. Rounding out the list is a new monkey with a blue-colored behind and human-like eyes, a tiny violet and a black staining fungus that threatens rare Paleolithic cave paintings in France.

"We have identified only about two million of an estimated 10 to 12 million living species and that does not count most of the microbial world," said Quentin Wheeler, founding director of the International Institute for Species Exploration at ASU and author of "What on Earth? 100 of our Planet's Most Amazing New Species" (NY, Plume, 2013).

"For decades, we have averaged 18,000 species discoveries per year which seemed reasonable before the biodiversity crisis. Now, knowing that millions of species may not survive the 21st century, it is time to pick up the pace," Wheeler added.

"We are calling for a NASA-like mission to discover 10 million species in the next 50 years. This would lead to discovering countless options for a more sustainable future while securing evidence of the origins of the biosphere," Wheeler said.

Taxon experts pick top 10

Members of the international committee made their top 10 selection from more than 140 nominated species. To be considered, species must have been described in compliance with the appropriate code of nomenclature, whether botanical, zoological or microbiological, and have been officially named during 2012.

"Selecting the final list of new species from a wide representation of life forms such as bacteria, fungi, plants and animals, is difficult. It requires finding an equilibrium between certain criteria and the special insights revealed by selection committee members," said Antonio Valdecasas, a biologist and research zoologist with Museo Nacional de Ciencias Naturales in Madrid, Spain. Valdecasas is the international selection committee chairman for the top 10 new species.

"We look for organisms with unexpected features or size and those found in rare or difficult to reach habitats. We also look for organisms that are especially significant to humans — those that play a certain role in human habitat or that are considered a close relative," Valdecasas added.

This year's top 10 come from Peru; NE Pacific Ocean, USA: California; Democratic Republic of the Congo; Panama; France; New Guinea; Madagascar; Ecuador; Malaysia; and China.

Top 10 New Species, 2013

"I don't know whether to be more astounded by the species discovered each year, or the depths of our ignorance about biodiversity of which we are a part," shared Wheeler.

"At the same time we search the heavens for other earthlike planets, we should make it a high priority to explore the biodiversity on the most earthlike planet of them all: Earth," he added. "With more than eight out of every 10 living species awaiting discovery, I am shocked by our ignorance of our very own planet and in awe at the diversity, beauty and complexity of the biosphere and its inhabitants."

Describing the discoveries

Lilliputian Violet
Viola lilliputana
Country: Peru

Tiny violet: Not only is the Lilliputian violet among the smallest violets in the world, it is also one of the most diminutive terrestrial dicots. Known only from a single locality in an Intermontane Plateau of the high Andes of Peru, Viola lilliputana lives in the dry puna grassland eco-region. Specimens were first collected in the 1960s, but the species was not described as a new until 2012. The entire above ground portion of the plant is barely 1 centimeter tall. Named, obviously, for the race of little people on the island of Lilliput in Jonathan Swift's Gulliver's Travels.

Lyre Sponge
Chondrocladia lyra
Country: NE Pacific Ocean; USA: California

Carnivorous sponge: A spectacular, large, harp- or lyre-shaped carnivorous sponge discovered in deep water (averaging 3,399 meters) from the northeast Pacific Ocean off the coast of California. The harp-shaped structures or vanes number from two to six and each has more than 20 parallel vertical branches, often capped by an expanded, balloon-like, terminal ball. This unusual form maximizes the surface area of the sponge for contact and capture of planktonic prey.

Lesula Monkey
Cercopithecus lomamiensis
Country: Democratic Republic of the Congo

Old World monkey: Discovered in the Lomami Basin of the Democratic Republic of the Congo, the lesula is an Old World monkey well known to locals but newly known to science. This is only the second species of monkey discovered in Africa in the past 28 years. Scientists first saw the monkey as a captive juvenile in 2007. Researchers describe the shy lesula as having human-like eyes. More easily heard than seen, the monkeys perform a booming dawn chorus. Adult males have a large, bare patch of skin on the buttocks, testicles and perineum that is colored a brilliant blue. Although the forests where the monkeys live are remote, the species is hunted for bush meat and its status is vulnerable.

No to the Mine! Snake
Sibon noalamina
Country: Panama

Snail-eating snake: A beautiful new species of snail-eating snake has been discovered in the highland rainforests of western Panama. The snake is nocturnal and hunts soft-bodied prey including earthworms and amphibian eggs, in addition to snails and slugs. This harmless snake defends itself by mimicking the alternating dark and light rings of venomous coral snakes. The species is found in the Serranía de Tabasará mountain range where ore mining is degrading and diminishing its habitat. The species name is derived from the Spanish phrase "No a la mina" or "No to the mine."

A Smudge on Paleolithic Art
Ochroconis anomala
Country: France

Fungus: In 2001, black stains began to appear on the walls of Lascaux Cave in France. By 2007, the stains were so prevalent they became a major concern for the conservation of precious rock art at the site that dates back to the Upper Paleolithic. An outbreak of a white fungus, Fusarium solani, had been successfully treated when just a few months later, black staining fungi appeared. The genus primarily includes fungi that occur in the soil and are associated with the decomposition of plant matter. As far as scientists know, this fungus, one of two new species of the genus from Lascaux, is harmless. However, at least one species of the group, O. gallopava, causes disease in humans who have compromised immune systems.

World's Smallest Vertebrate
Paedophryne amanuensis
Country: New Guinea

Tiny frog: Living vertebrates — animals that have a backbone or spinal column — range in size from this tiny new species of frog, as small as 7 millimeters, to the blue whale, measuring 25.8 meters. The new frog was discovered near Amau village in Papua, New Guinea. It captures the title of 'smallest living vertebrate' from a tiny Southeast Asian cyprinid fish that claimed the record in 2006. The adult frog size, determined by averaging the lengths of both males and females, is only 7.7 millimeters. With few exceptions, this and other ultra-small frogs are associated with moist leaf litter in tropical wet forests — suggesting a unique ecological guild that could not exist under drier circumstances.

Endangered Forest
Eugenia petrikensis
Country: Madagascar

Endangered shrub: Eugenia is a large, worldwide genus of woody evergreen trees and shrubs of the myrtle family that is particularly diverse in South America, New Caledonia and Madagascar. The new species E. petrikensis is a shrub growing to two meters with emerald green, slightly glossy foliage and beautiful, dense clusters of small magenta flowers. It is one of seven new species described from the littoral forest of eastern Madagascar and is considered to be an endangered species. It is the latest evidence of the unique and numerous species found in this specialized, humid forest that grows on sandy substrate within kilometers of the shoreline. Once forming a continuous band 1,600 kilometers long, the littoral forest has been reduced to isolated, vestigial fragments under pressure from human populations.

Lightning Roaches?
Lucihormetica luckae
Country: Ecuador

Glow-in-the-dark cockroach: Luminescence among terrestrial animals is rather rare and best known among several groups of beetles — fireflies and certain click beetles in particular — as well as cave-inhabiting fungus gnats. Since the first discovery of a luminescent cockroach in 1999, more than a dozen species have (pardon the pun) "come to light." All are rare, and interestingly, so far found only in remote areas far from light pollution. The latest addition to this growing list is L. luckae that may be endangered or possibly already extinct. This cockroach is known from a single specimen collected 70 years ago from an area heavily impacted by the eruption of the Tungurahua volcano. The species may be most remarkable because the size and placement of its lamps suggest that it is using light to mimic toxic luminescent click beetles.

No Social Butterfly
Semachrysa jade
Country: Malaysia

Social media lacewing: In a trend-setting collision of science and social media, Hock Ping Guek photographed a beautiful green lacewing with dark markings at the base of its wings in a park near Kuala Lumpur and shared his photo on Flickr. Shaun Winterton, an entomologist with the California Department of Food and Agriculture, serendipitously saw the image and recognized the insect as unusual. When Guek was able to collect a specimen, it was sent to Stephen Brooks at London's Natural History Museum who confirmed its new species status. The three joined forces and prepared a description using Google Docs. In this triumph for citizen science, talents from around the globe collaborated by using new media in making the discovery. The lacewing is not named for its color — rather for Winterton's daughter, Jade.

Hanging Around in the Jurassic
Juracimbrophlebia ginkgofolia
Country: China

Hangingfly fossil: Living species of hangingflies can be found, as the name suggests, hanging beneath foliage where they capture other insects as food. They are a lineage of scorpionflies characterized by their skinny bodies, two pairs of narrow wings, and long threadlike legs. A new fossil species, Juracimbrophlebia ginkgofolia, has been found along with preserved leaves of a gingko-like tree, Yimaia capituliformis, in Middle Jurassic deposits in the Jiulongshan Formation in China's Inner Mongolia. The two look so similar that they are easily confused in the field and represent a rare example of an insect mimicking a gymnosperm 165 million years ago, before an explosive radiation of flowering plants.

Why create a top 10 new species list?

Arizona State University's International Institute for Species Exploration announces the top 10 new species list each year as part of its public awareness campaign to bring attention to biodiversity and the field of taxonomy.

"Sustainable biodiversity means assuring the survival of as many and as diverse species as possible so that ecosystems are resilient to whatever stresses they face in the future. Scientists will need access to as much evidence of evolutionary history as possible," said the institute's Wheeler, who is also a professor in ASU's School of Life Sciences in the College of Liberal Arts and Sciences, and in the School of Sustainability, as well as a senior sustainability scientist with the Global Institute of Sustainability.

"All of our hopes and dreams for conservation hinge upon saving millions of species that we cannot recognize and know nothing about," Wheeler added. "No investment makes more sense than completing a simple inventory to the establish baseline data that tells us what kinds of plants and animals exist and where. Until we know what species already exist, it is folly to expect we will make the right decisions to assure the best possible outcome for the pending biodiversity crisis."

Additionally, the announcement is made on or near May 23 to honor Linnaeus. Since he initiated the modern system for naming plants and animals, nearly two million species have been named, described and classified. Excluding unknown millions of microbes, scientists estimate there are between 10 and 12 million living species.

IISE International Selection Committee: Antonio G. Valdecasas, Museo Nacional de Ciencias Naturales, CSIC, Spain, Committee Chair; Andrew Polaszek, Natural History Museum, England; Ellinor Michel, Natural History Museum, England; Marcelo Rodrigues de Carvalho, Universidade de São Paulo; Aharon Oren, The Hebrew University of Jerusalem; Mary Liz Jameson, Wichita State University, USA; Alan Paton, Kew Royal Botanical Gardens, England; James A. Macklin, Agriculture and Agri-Food Canada, Canada; John S. Noyes, Natural History Museum, England; Zhi-Qiang Zhang, Landcare Research, New Zealand; and Gideon Smith, South African National Biodiversity Institute, South Africa.

Nominations for the 2014 list — for species described in 2013 — may be made online at http://species.asu.edu/species-nomination. Previous top 10 lists are available at: http://species.asu.edu.

Contacts and sources:
Sandra Leander
Arizona State University

NASA's SDO Observes Mid-level Solar Flare

2013-05-23T09:30:00.002-04:00

The M7-class flare was also associated with a coronal mass ejection or CME, another solar phenomenon that can send billions of tons of particles into space. While this CME was not Earth-directed, it has combined with an earlier CME, and the flank of the combined cloud may pass Earth. Particles from the CME cannot travel through the atmosphere to harm humans on Earth, but they can affect electronic systems in satellites and on the ground.

This image, captured at 11:06 a.m. EDT on May 22, 2013, from the ESA/NASA Solar and Heliospheric Observatory shows theconjunction of two coronal mass ejections streaming away from the sun. This image is what's known as a coronagraph, in which the light of the sun is blocked in order to make its dimmer atmosphere, the corona, visible

Credit: ESA and NASA/SOHO

Experimental NASA research models, based on observations from NASA’s Solar Terrestrial Relations Observatory and ESA/NASA’s Solar and Heliospheric Observatory show that the first CME began at 5:12 a.m. EDT, leaving the sun at about 400 miles per second. The second CME began at 9:24 a.m. EDT, leaving the sun at speeds of around 745 miles per second.

Earth-directed CMEs can cause a space weather phenomenon called a geomagnetic storm, which occurs when they funnel energy into Earth's magnetic envelope, the magnetosphere, for an extended period of time. In the past, geomagnetic storms caused by CMEs of this strength have usually been mild.

The NASA models also show that the combined CMEs will pass by the STEREO-A spacecraft and its mission operators have been notified. If warranted, operators can put spacecraft into safe mode to protect the instruments from the solar material.

NASA and NOAA – as well as the US Air Force Weather Agency (AFWA) and others -- keep a constant watch on the sun to monitor for space weather effects such as geomagnetic storms. With advance notification many satellites, spacecraft and technologies can be protected from the worst effects

NOAA's Space Weather Prediction Center (http://swpc.noaa.gov) is the U.S. government's official source for space weather forecasts, alerts, watches and warnings.

NASA’s Solar Dynamics Observatory captured this image of a solar flare on the right side of the sun on May 22, 2013. This image shows light in the 131 Angstrom wavelength, a wavelength that shows material heated to intense temperatures during a flare and that is typically colorized in teal.

Credit: NASA/SDO

The sun emitted a mid-level solar flare on the morning of May 22, 2013. The flare peaked at 9:38 a.m. EDT and was classified as an M7. M-class flares are the weakest flares that can still cause some space weather effects near Earth. In the past, they have caused brief radio blackouts at the poles.

Solar flares are powerful bursts of radiation. Harmful radiation from a flare cannot pass through Earth's atmosphere to physically affect humans on the ground, however -- when intense enough -- they can disturb the atmosphere in the layer where GPS and communications signals travel. This disrupts the radio signals for as long as the flare is ongoing, anywhere from minutes to hours.

Increased numbers of flares are quite common at the moment, since the sun's normal 11-year activity cycle is ramping up toward solar maximum, which is expected in late 2013. Humans have tracked this solar cycle continuously since it was discovered in 1843, and it is normal for there to be many flares a day during the sun's peak activity.

NOAA's Space Weather Prediction Center (http://swpc.noaa.gov) is the U.S. government's official source for space weather forecasts, alerts, watches and warnings. Updates will be provided as they are available on the flare and whether there was an associated coronal mass ejection or CME, another solar phenomenon that can send solar particles into space and affect electronic systems in satellites and on Earth.

These images of a solar flare were captured by NASA’s Solar Dynamics Observatory on May 22, 2013. This image shows light in the 131 Angstrom wavelength, a wavelength that shows material heated to intense temperatures during a flare and that is typically colorized in teal.

Credit: NASA/SDO/GSFC

Contacts and sources:

Karen C. Fox
NASA's Goddard Space Flight Cente

Alleviating Hunger In The US -- Researcher Says, It's A SNAP

2013-05-22T16:09:00.002-04:00

A University of Illinois researcher says that the cornerstone of our efforts to alleviate food insecurity should be to encourage more people to participate in the Supplemental Nutrition Assistance Program (SNAP) "because it works."

Credit: University of Illinois

According to Craig Gundersen, SNAP, formerly known as the Food Stamp Program, is a great social safety net program and with some additional improvements could be even more successful at reducing the number of food-insecure households. Gundersen is a U of I professor of agricultural and consumer economics and executive director of the National Soybean Research Laboratory.

"We already know that SNAP leads to reductions in food insecurity, and poverty, and there is no evidence that it leads to obesity," Gundersen said. "We need to make it easier for people to apply for the program, to recertify once they're in the program, and to increase benefits, especially for those who are at the lower end of the benefits structure," he said.

Gundersen says that reducing the stigma associated with receiving SNAP benefits would be an improvement but difficult to accomplish because it requires a shift in attitudes.

"There is a perception among some that people who receive SNAP benefits are lazy – this has historically been the reason for stigma in SNAP," Gundersen said. "In recent years, the stigma associated with SNAP participation has shifted toward a prejudice against people who are overweight. You hear a lot of anecdotal evidence that people who are overweight may be uncomfortable using SNAP. They feel like people are judging them for buying food. If we could become a society that doesn't judge others about their weight, we could reduce stigma."

One surprising outcome from Gundersen's research on the topic is that about half of poor households in the United States are food secure, despite having low incomes. "One reason is perhaps that, along with other factors, they may just be better financial managers," he said. And although it appears to come naturally to some people to be responsible financially, there is evidence that financial management skills can be taught. "Using coupons, shopping at large-scale supermarkets, and buying in bulk can save households money on food," he said.

Gundersen said that the SNAP-Ed program provides some education in financial management. "About 70 percent of SNAP households have at least one person who is working, but for them, it may be hard to find the time to take classes."

Food pantries and other emergency food assistance programs play an important role in the effort to alleviate food insecurity.

"A lot of SNAP recipients are from poor households who just run out of money or SNAP benefits at the end of the month," Gundersen said. "Food pantries can tide people over until the next month. And about one-third of food-insecure households have high enough incomes that they are ineligible for any of the other food assistance programs. The only place they can go for help is to food pantries, so it's really important that we have those available for them."

Lowering food prices and making large-scale food stores more accessible to lower-income neighborhoods in cities are also ways to help reduce food insecurity. "Large-scale supermarkets like Walmart are finding it difficult to get permits to put stores in big cities, such as New York City and San Francisco, two of the most expensive cities to live in," Gundersen said. "Walmart's core customer makes between $20,000 and $50,000 per year, but upper-income people block Walmart despite the good that would come from having a discount grocery store convenient to where lower income families live. It's frustrating to Walmart, to me, and to anti-hunger advocates."

Gundersen also responded to the recent efforts to increase taxes on foods such as sugar-sweetened beverages. "I think it just punishes poor people for their food choices," he said. Taxing foods that have no nutritional content is also a bureaucratic nightmare, according to Gundersen. "Stores would have to add a lot of expensive signage and reconfigure cash registers to read new bar codes on foods that may or may not be eligible for SNAP. And who would make those decisions? It's also just patronizing and offensive to poor people; it's telling them that because they don't know how to shop for their family, we'll tell you how to shop and what's best for them. When I worked for the federal government, no one told me how to spend my paycheck, and Social Security recipients aren't told how they can spend their money," he said.

Gundersen said that the National School Lunch Program (NSLP) also reduces food insecurity. Given the importance of NSLP in alleviating hunger, it is not surprising that food insecurity among children rises during the summer. "There are summer food-service programs, but typically children have to be enrolled in a camp or summer school program to get the free lunch. We definitely see spikes in food insecurity over the summer months," he said.

Food insecurity climbed rapidly in the 2007-08 years and has now leveled off at a high level, Gundersen said. "Even though we're on the other side of the great recession, we haven't seen declines in food security."

Contacts and sources:
Debra Levey Larson
University of Illinois College of Agricultural, Consumer and Environmental Sciences

Overeating Learned In Infancy, Study Suggests

2013-05-22T16:05:00.003-04:00

In the long run, encouraging a baby to finish the last ounce in their bottle might be doing more harm than good.

Though the calories soon burn off, a bad habit remains.

Brigham Young University sociology professors Ben Gibbs and Renata Forste found that clinical obesity at 24 months of age strongly traces back to infant feeding.

“If you are overweight at age two, it puts you on a trajectory where you are likely to be overweight into middle childhood and adolescence and as an adult,” said Forste. “That’s a big concern.”

The BYU researchers analyzed data from more than 8,000 families and found that babies predominantly fed formula were 2.5 times more likely to become obese toddlers than babies who were breastfed for the first six months.

But, the study authors argue, this pattern is not just about breastfeeding.

“There seems to be this cluster of infant feeding patterns that promote childhood obesity,” said Gibbs, lead author of the study that appears in Pediatric Obesity.

Putting babies to bed with a bottle increased the risk of childhood obesity by 36 percent. And introducing solid foods too soon – before four months of age – increased a child’s risk of obesity by 40 percent.

“Developing this pattern of needing to eat before you go to sleep, those kinds of things discourage children from monitoring their own eating patterns so they can self-regulate,” Forste said.

Forste said that the nature of breastfeeding lends itself to helping babies recognize when they feel full and should stop. But that same kind of skill can be developed by formula-fed infants.

“You can still do things even if you are bottle feeding to help your child learn to regulate their eating practices and develop healthy patterns,” Forste said. “When a child is full and pushes away, stop! Don’t encourage them to finish the whole bottle.”

Breastfeeding rates are lowest in poor and less educated families. Sally Findley, a public health professor at Columbia University, says the new BYU study shows that infant feeding practices are the primary reason that childhood obesity hits hardest below the poverty line.

“Bottle feeding somehow changes the feeding dynamic, and those who bottle feed, alone or mixed with some breastfeeding, are more likely to add cereal or sweeteners to their infant’s bottle at an early age, even before feeding cereal with a spoon,” said Findley.

The next project for Gibbs and Forste is to reevaluate the link between breastfeeding and cognitive development in childhood. Forste has previously published research about why women stop breastfeeding. You can listen her discuss that topic with The New York Times in this podcast.

“The health community is looking to the origins of the obesity epidemic, and more and more, scholars are looking toward early childhood,” Gibbs said. “I don’t think this is some nascent, unimportant time period. It’s very critical.”

Contacts and sources:
Joe Hadfield
Brigham Young University

Small, Speedy Plant-Eater Extends Knowledge Of Dinosaur Ecosystems

2013-05-22T16:02:00.005-04:00

Dinosaurs are often thought of as large, fierce animals, but new research highlights a previously overlooked diversity of small dinosaurs. In the Journal of Vertebrate Paleontology, a team of paleontologists from the University of Toronto, Royal Ontario Museum, Cleveland Museum of Natural History and University of Calgary have described a new dinosaur, the smallest plant-eating dinosaur species known from Canada. Albertadromeus syntarsus was identified from a partial hind leg, and other skeletal elements, that indicate it was a speedy runner. Approximately 1.6 m (5 ft) long, it weighed about 16 kg (30 lbs), comparable to a large turkey.

This is a life reconstruction of the new small-bodied, plant-eating dinosaur Albertadromeus syntarsus.

Credit: Art by Julius T. Csotonyi.

Albertadromeus lived in what is now southern Alberta in the Late Cretaceous, about 77 million years ago. Albertadromeus syntarsus means "Alberta runner with fused foot bones". Unlike its much larger ornithopod cousins, the duckbilled dinosaurs, its two fused lower leg bones would have made it a fast, agile two-legged runner. This animal is the smallest known plant-eating dinosaur in its ecosystem, and researchers hypothesize that it used its speed to avoid predation by the many species of meat-eating dinosaurs that lived at the same time.

Albertadromeus was discovered in 2009 by study co-author David Evans of the Royal Ontario Museum as part an on-going collaboration with Michael Ryan of the Cleveland Museum of Natural History to investigate the evolution of dinosaurs in the Late Cretaceous of North America. The known dinosaur diversity of this time period is dominated by large bodied plant-eating dinosaurs.

Skeletal outlines illustrate both the relative size and completeness of two of the small ornithopod specimens described in the paper. Bones indicated in white are present. Human (in gray) for scale.

Credit: Illustration by C. Brown

Why are so few small-bodied dinosaurs known from North America some 77 million years ago? Smaller animals are less likely to be preserved than larger ones, because their bones are more delicate and are often destroyed before being fossilized. "We know from our previous research that there are preservational biases against the bones of these small dinosaurs," said Caleb Brown of the University of Toronto, lead author of the study. "We are now starting to uncover this hidden diversity, and although skeletons of these small ornithopods are both rare and fragmentary, our study shows that these dinosaurs were more abundant in their ecosystems than previously thought."

The reason for our relatively poor understanding of these small dinosaurs is a combination of the taphonomic processes (those related to decay and preservation) described above, and biases in the way that material has been collected. Small skeletons are more prone to destruction by carnivores, scavengers and weathering processes, so fewer small animals are available to become fossils and smaller animals are often more difficult to find and identify than those of larger animals.

"Albertadromeus may have been close to the bottom of the dinosaur food chain but without dinosaurs like it you'd not have giants like T. rex," said Michael Ryan. "Our understanding of the structure of dinosaur ecosystems is dependent on the fossils that have been preserved. Fragmentary, but important, specimens like that of Albertadromeus suggest that we are only beginning to understand the shape of dinosaur diversity and the structure of their communities."

This is a photograph and interpretive drawing of the lower jaw, as well as a complete tooth, of one of the small ornithopods described in the study. Human (in gray) for scale.

Credit: Illustration by C. Brown

"You can imagine such small dinosaurs filling the niche of animals such as rabbits and being major, but relatively inconspicuous, members of their ecological community" said Anthony Russell of the University of Calgary.

Contacts and sources:
Cody Mooneyhan
Society of Vertebrate Paleontology

About the Society of Vertebrate Paleontology

Founded in 1940 by thirty-four paleontologists, the Society now has more than 2,300 members representing professionals, students, artists, preparators, and others interested in VP. It is organized exclusively for educational and scientific purposes, with the object of advancing the science of vertebrate paleontology.

Society of Vertebrate Paleontology: http://www.vertpaleo.org

About the Journal of Vertebrate Paleontology

The Journal of Vertebrate Paleontology (JVP) is the leading journal of professional vertebrate paleontology and the flagship publication of the Society. It was founded in 1980 by Dr. Jiri Zidek and publishes contributions on all aspects of vertebrate paleontology.

For complimentary access to the full article, visit: http://www.tandfonline.com/doi/full/10.1080/02724634.2013.746229#.UZzxoMiRNQA orhttp://www.tandfonline.com/doi/pdf/10.1080/02724634.2013.746229

The article appears in the Journal of Vertebrate Paleontology 33(3) published by Taylor and Francis.

Citation: Brown CM, Evans DC, Ryan MJ, and Russell AP. 2013. New data on the diversity and abundance of small-bodied ornithopods (DINOSAURIA: ORNITHISCHIA) from the Belly River Group (Campanian) of Alberta. Journal of Vertebrate Paleontology 33(3):1-26.

Magnetic Field Misbehavior In Solar Flares: The Culprit Is Turbulence

2013-05-22T15:58:00.002-04:00

When a solar flare filled with charged particles erupts from the sun, its magnetic fields sometime break a widely accepted rule of physics. The flux-freezing theorem dictates that the magnetic lines of force should flow away in lock-step with the particles, whole and unbroken. Instead, the lines sometimes break apart and quickly reconnect in a way that has mystified astrophysicists.

New research led by a Johns Hopkins mathematical physicist focuses on the “misbehavior” of magnetic fields in solar flares. In this image, the Solar Dynamics Observatory (SDO) captured an X1.2 class solar flare, peaking on May 15, 2013.

Credit: NASA/SDO

But in a paper published in the May 23 issue of the journal Nature, an interdisciplinary research team led by a Johns Hopkins mathematical physicist says it has found a key to the mystery. The culprit, the group proposed, is turbulence—the same sort of violent disorder that can jostle a passenger jet when it occurs in the atmosphere. Using complex computer modeling to mimic what happens to magnetic fields when they encounter turbulence within a solar flare, the researchers built their case, explaining why the usual rule did not apply.

“The flux-freezing theorem often explains things beautifully,” said Gregory Eyink, a Department of Applied Mathematics and Statistics professor who was lead author of the Naturestudy. “But in other instances, it fails miserably. We wanted to figure out why this failure occurs.”

Gregory Eyink, professor of applied mathematics and statistics at Johns Hopkins.

Photo by Nat Creamer.

The flux-freezing theorem was developed 70 years ago by Hannes Alfvén, who later won a Nobel Prize in physics for closely related work. His principle states that magnetic lines of force are carried along in a moving fluid like strands of thread cast into a river, and thus they can never “break” and reconnect. But scientists have discovered that within violent solar flares, the principle does not always hold true. Studies of these flares have determined that their magnetic field lines sometimes do break like stretched rubber bands and reconnect in as little as 15 minutes, releasing vast amounts of energy that power the flare. “But the flux-freezing principle of modern plasma physics implies that this process in the solar corona should take a million years!” Eyink said. “A big problem in astrophysics is that no one could explain why flux-freezing works in some cases but not others.”

Some scientists suspected that turbulence was playing havoc with the behavior predicted by this principle. To find out, Eyink teamed up with other experts in astrophysics, mechanical engineering, data management and computer science, based at Johns Hopkins and other institutions. “By necessity, this was a highly collaborative effort,” Eyink said. “Everyone was contributing their expertise. No one person could have accomplished this.”

The team developed a computer simulation to replicate what happens under various conditions to the charged particles that exist in a plasma state of matter within solar flares. “Our answer was very surprising,” Eyink said. “Magnetic flux-freezing no longer holds true when the plasma becomes turbulent. Most physicists expected that flux-freezing would play an even larger role as the plasma became more highly conducting and more turbulent, but, as a matter of fact, it breaks down completely. In an even greater surprise, we found that the motion of the magnetic field lines becomes completely random. I do not mean ‘chaotic,’ but instead as unpredictable as quantum mechanics. Rather than flowing in an orderly, deterministic fashion, the magnetic field lines instead spread out like a roiling plume of smoke.”

Although some scholars may still believe there are other explanations for solar flares, Eyink said, “I think we made a pretty compelling case that turbulence alone can account for field-line breaking.”

The way the researchers from different disciplines teamed up with Eyink to solve the solar flare puzzle was particularly noteworthy. “We used ground-breaking new database methods, like those employed in the Sloan Digital Sky Survey, combined with high-performance computing techniques and original mathematical developments,” he said. “The work required a perfect marriage of physics, mathematics and computer science to develop a fundamentally new approach to performing research with very large datasets.”

Eyink added that the research could lead to a better understanding of solar flares and mass ejections of material from the sun’s corona. Such powerful “space weather” or geomagnetic storms can endanger astronauts, knock out communications satellites and even lead to massive blackouts of electrical power grids on Earth, he said.

Co-authors of the Nature study from Johns Hopkins’s Whiting School of Engineering and Krieger School of Arts and Sciences were Cristian Lalescu and Hussein Aluie, from the Department of Applied Mathematics and Statistics; Kalin Kanov and Randal Burns, from the Department of Computer Science; Charles Meneveau, from the Department of Mechanical Engineering; and Alexander Szalay, from the Department of Physics and Astronomy. Aluie is also affiliated with the Los Alamos National Laboratory. The authors of this study are also affiliated with Johns Hopkins’ Institute for Data Intensive Engineering and Science (IDIES), which has been facilitating groundbreaking research based on big data.

The co-authors from other institutions were Ethan Vishniac, from the Department of Physics and Engineering Physics, University of Saskatchewan, Canada; and Kai Bürger, from Fakultät für Informatik, Technische Universität München, Munich, Germany.

Funding for the research came from National Science Foundation grant CDI-II: CMMI 0941530, and the database infrastructure was funded by NSF grant OCI-108849 and by Johns Hopkins’ Institute for Data Intensive Engineering and Science. Support also was provided by Microsoft Research. Vishniac’s work was supported by the National Science and Engineering Research Council of Canada.

The turbulence data on which the analysis relies are publicly available at http://turbulence.pha.jhu.edu

Contacts and sources:
Phil Sneiderman
Johns Hopkins University