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Tuesday, July 22, 2014

Amplifying The Force Of The Vacuum, Empty Space Bubbling Soup Of Virtual Particles

Vacuum fluctuations may be among the most counter-intuitive phenomena of quantum physics. Theorists from the Weizmann Institute (Rehovot, Israel) and the Vienna University of Technology propose a way to amplify their force.

Vacuum is not as empty as one might think. In fact, empty space is a bubbling soup of various virtual particles popping in and out of existence – a phenomenon called “vacuum fluctuations”. Usually, such extremely short-lived particles remain completely unnoticed, but in certain cases vacuum forces can have a measurable effect.

Two atoms exchanging a virtual photon. Empty space around them is not as empty as one might think.
Credit:  TU Vienna

A team of researchers from the Weizmann Institute of Science (Rehovot, Israel) and the Vienna University of Technology has now proposed a method of amplifying these forces by several orders of magnitude using a transmission line, channelling virtual photons.

“Borrowing” Energy, but just for a Little While

If you park your car somewhere and later it is gone, that is most probably not due to vacuum fluctuations. Objects do not disappear or reappear, that would violate the law of energy conservation. In the world of quantum physics, however, things are a bit more complicated. “Due to the uncertainty principle, virtual particles can come into existence for a brief period of time”, says Igor Mazets from the Vienna University of Technology. “The higher their energy, the faster they will disappear again.”

But such virtual particles can have a measurable collective effect. At very short distances, vacuum fluctuations can lead to an attractive force between atoms or molecules – the Van der Waals forces. Even the ability of a gecko to climb flat surfaces can in part be attributed to vacuum fluctuations and virtual particles. The famous Casimir effect is another example of the power of the vacuum: The physicist Hendrik Casimir calculated in 1948 that two parallel mirrors in empty space will attract each other due to the way they influence the vacuum around them.

Atoms and Photons

Two atoms close to each other will also change the local vacuum around them. If one of them emits a virtual photon, which is almost instantly absorbed by the other, then on any timescale larger than the brief moment of the photon’s existence, nothing much has happened – the total energy is conserved. But the fact that virtual particles can be exchanged modifies the vacuum around the atoms, and this leads to a force.

“Usually, such forces are very hard to measure”, says Igor Mazets. “This is partly due to the fact, that such a photon may be emitted into any direction, and the chances of the second atom absorbing it are very small.”

But what if the virtual particle has a little help to find its way? Ephraim Shahmoon, Gershon Kurizki (Weizmann Institute of Science) and Igor Mazets calculated what happens to vacuum forces between atoms when they are placed in the vicinity of an electrical transmission line such as a coaxial cable or a coplanar waveguide (a device used in cavity quantum electrodynamics experiments as an open transmission line), cooled to very low temperatures. “In that case, the fluctuations are effectively confined to one dimension”, says Igor Mazets. The virtual particles will be forced to go into the direction of the other atom.

In that case, the fluctuation-mediated attraction between the atoms becomes orders of magnitude stronger than in free space. Usually, the force decreases rapidly with increasing distance between the atoms. Due to the transmission line, it falls off with one over the distance cubed, instead of one over the seventh power of the distance, as in the usual case.

The researchers believe that their proposed enhancement of the power of vacuum fluctuations can have profound implications for understanding Casimir- and Van der Waals forces and it may even be used for applications in quantum information processing and other emerging quantum technologies.



Contacts and sources:
Vienna University of Technology, TU Vienna

Mammoth and Mastodon Behavior Was More Stay At Home Than Roam

Their scruffy beards weren't ironic, but there are reasons mammoths and mastodons could have been the hipsters of the Ice Age.

According to research from the University of Cincinnati, the famously fuzzy relatives of elephants liked living in Greater Cincinnati long before it was trendy – at the end of the last ice age. A study led by Brooke Crowley, an assistant professor of geology and anthropology, shows the ancient proboscideans enjoyed the area so much they likely were year-round residents and not nomadic migrants as previously thought. 

Research led by UC's Brooke Crowley, posing with this mammoth mandible, has uncovered some interesting ideas about mammoth and mastodon behavior.
Credit: Dottie Stover, UC Creative Services

They even had their own preferred hangouts. Crowley's findings indicate each species kept to separate areas based on availability of favored foods here at the southern edge of the Last Glacial Maximum's major ice sheet.

"I suspect that this was a pretty nice place to live, relatively speaking," Crowley says. "Our data suggest that animals probably had what they needed to survive here year-round."

COULD THE PAST SAVE THE FUTURE?

Crowley's research with co-author and recent UC graduate Eric Baumann, "Stable Isotopes Reveal Ecological Differences Among Now-Extinct Proboscideans from the Cincinnati Region, USA," was recently published in Boreas, an international academic research journal.

UC's Brooke Crowley uses isotopic analysis in her research. Here she works with samples of bones from extinct lemurs.
Credit: Dottie Stover, UC Creative Services

Learning more about the different behaviors of these prehistoric creatures could benefit their modern-day cousins, African and Asian elephants. Both types are on the World Wildlife Fund's endangered species list. Studying how variable different types of elephants might have been in the past, Crowley says, might help ongoing efforts to protect these largest of land mammals from continued threats such as poaching and habitat destruction.

"There are regionally different stories going on," Crowley says. "There's not one overarching theme that we can say about a mammoth or a mastodon. And that's becoming more obvious in studies people are doing in different places. A mammoth in Florida did not behave the same as one in New York, Wyoming, California, Mexico or Ohio."

THE WISDOM IN TEETH

For their research, Crowley and Baumann looked to the wisdom in teeth – specifically museum specimens of molars from four mastodons and eight mammoths from Southwestern Ohio and Northwestern Kentucky. Much can be revealed by carefully drilling a tooth's surface and analyzing the stable carbon, oxygen and strontium isotopic signatures in the powdered enamel. 

UC graduate Eric Baumann worked with Brooke Crowley researching mammoth and mastodon behavior.
  Photo provided by Brooke Crowley

Each element tells a different story. Carbon provides insight into an animal's diet, oxygen relates to overall climatic conditions of an animal's environment and strontium indicates how much an animal may have traveled at the time its tooth was forming.

"Strontium reflects the bedrock geology of a location," Crowley says. "So if a local animal grows its tooth and mineralizes it locally and dies locally, the strontium isotope ratio in its tooth will reflect the place where it lived and died. If an animal grows its tooth in one place and then moves elsewhere, the strontium in its tooth is going to reflect where it came from, not where it died."

Their analysis allowed them to determine several things:

Mammoths ate more grasses and sedges than mastodons, which favored leaves from trees or shrubs.
Strontium from all of the animals (except one mastodon) matched local water samples, meaning they likely were less mobile and migratory than previously thought.
Differences in strontium and carbon between mammoths and mastodons suggest they didn't inhabit the same localities.
Mammoths preferred to be closer to the retreating ice sheet where grasses were more abundant, whereas mastodons fed farther from the ice sheet in more forested habitat.

“As a geologist, questioning the past is one of the most interesting and exciting things to do,” says Baumann, an environmental geologist with a contractor for the U.S. Environmental Protection Agency. “Based on our data, mammoths and mastodons seemed to have different diets and lived in different areas during their lives. This is important because it allows us to understand how species in the past lived and interacted. And the past is the key to the present.”

Crowley of the McMicken College of Arts and Sciences plans further research into how strontium isotopes can be used to explore megafauna, including other projects dealing with mammoths and mastodons.


Contacts and sources:
Tom Robinette
University of Cincinnati

Middle East Respiratory Syndrome Coronavirus Detected In The Air Of A Saudi Arabian Camel Barn

Saudi Arabian researchers have detected genetic fragments of Middle East Respiratory Syndrome coronavirus (MERS-CoV) in the air of a barn holding a camel infected with the virus. The work, published this week in mBio®, the online open-access journal of the American Society for Microbiology, indicates that further studies are needed to see if the disease can be transmitted through the air.


Credit: Wikipedia

MERS, a serious viral respiratory illness caused by the coronavirus, has been identified in 699 people as of June 11, according to the World Health Organization; 209 people have died from the condition. An additional 113 cases occurring between 2012 and 2014 were reported by the Saudi Arabian Ministry of Health on June 3.

For the study, researchers on three consecutive days last November collected three air samples from a camel barn owned by a 43-year-old male MERS patient who lived south of the town of Jeddah, who later died from the condition. Four of the man's nine camels had shown signs of nasal discharge the week before the patient became ill; he had applied a topical medicine in the nose of one of the ill camels seven days before experiencing symptoms.

Credit: Wikipedia

Using a laboratory technique called reverse transcription polymerase chain reaction (RT-PCR) to detect gene expression, they found that the first air sample, collected on November 7, contained genetic fragments of MERS-CoV. This was the same day that one of the patient's camels tested positive for the disease. The other samples did not test positive for MERS-CoV, suggesting short or intermittent shedding of the virus into the air surrounding the camels, said lead study author Esam Azhar, PhD, head of the Special Infectious Agents Unit at King Fahd Medical Research Center and associate professor of medical virology at King Abdulaziz University in Jeddah.

Additional experiments confirmed the presence of MERS-CoV-specific genetic sequences in the first air sample and found that these fragments were exactly identical to fragments detected in the camel and its sick owner.

"The clear message here is that detection of airborne MERS-CoV molecules, which were 100% identical with the viral genomic sequence detected from a camel actively shedding the virus in the same barn on the same day, warrants further investigations and measures to prevent possible airborne transmission of this deadly virus," Azhar said.

"This study also underscores the importance of obtaining a detailed clinical history with particular emphasis on any animal exposure for any MERS-CoV case, especially because recent reports suggest higher risk of MERS-CoV infections among people working with camels," he added.

Meanwhile, he said, mounting evidence for camel-to-human transmission of MERS-CoV warrants taking precautionary measures: People who care for camels or who work for slaughterhouses should wear face masks, gloves and protective clothing, and wash their hands frequently. It is also important to avoid contact with animals that are sick or have tested positive for MERS-CoV. Those who visit camel barns, farms or markets should wash hands before and after contact with animals. In addition, pasteurization of camel milk and proper cooking of camel meat are strongly recommended.

The study was supported by King Abdulaziz University.



Contacts and sources:
Jim Sliwa
American Society for Microbiology

Transiting Exoplanet With Longest Known Year

Astronomers have discovered a transiting exoplanet with the longest known year. Kepler-421b circles its star once every 704 days. In comparison, Mars orbits our Sun once every 780 days. Most of the 1,800-plus exoplanets discovered to date are much closer to their stars and have much shorter orbital periods.

"Finding Kepler-421b was a stroke of luck," says lead author David Kipping of the Harvard-Smithsonian Center for Astrophysics (CfA). "The farther a planet is from its star, the less likely it is to transit the star from Earth's point of view. It has to line up just right."

Credit:  Harvard-Smithsonian Center for Astrophysics

Kepler-421b orbits an orange, type K star that is cooler and dimmer than our Sun. It circles the star at a distance of about 110 million miles. As a result, this Uranus-sized planet is chilled to a temperature of -135° Fahrenheit.

As the name implies, Kepler-421b was discovered using data from NASA's Kepler spacecraft. Kepler was uniquely suited to make this discovery. The spacecraft stared at the same patch of sky for 4 years, watching for stars that dim as planets cross in front of them. No other existing or planned mission shows such long-term, dedicated focus. Despite its patience, Kepler only detected two transits of Kepler-421b due to that world's extremely long orbital period.

The planet's orbit places it beyond the "snow line" - the dividing line between rocky and gas planets. Outside of the snow line, water condenses into ice grains that stick together to build gas giant planets.

"The snow line is a crucial distance in planet formation theory. We think all gas giants must have formed beyond this distance," explains Kipping.

Since gas giant planets can be found extremely close to their stars, in orbits lasting days or even hours, theorists believe that many exoplanets migrate inward early in their history.

Kepler-421b shows that such migration isn't necessary. It could have formed right where we see it now.

"This is the first example of a potentially non-migrating gas giant in a transiting system that we've found," adds Kipping.

The host star, Kepler-421, is located about 1,000 light-years from Earth in the direction of the constellation Lyra.

This research has been accepted for publication in The Astrophysical Journal and is available online. Additional information can be found at https://www.cfa.harvard.edu/~dkipping/kepler421.html

Headquartered in Cambridge, Mass., the Harvard-Smithsonian Center for Astrophysics (CfA) is a joint collaboration between the Smithsonian Astrophysical Observatory and the Harvard College Observatory. CfA scientists, organized into six research divisions, study the origin, evolution and ultimate fate of the universe.

Sunday, July 20, 2014

3D Printed Bodies To Teach Doctors

The creators of a unique kit containing anatomical body parts produced by 3D printing say it will revolutionize medical education and training, especially in countries where cadaver use is problematical.

The ‘3D Printed Anatomy Series’, developed by experts from Monash University, is thought to be the first commercially available resource of its kind. The kit contains no human tissue, yet it provides all the major parts of the body required to teach anatomy of the limbs, chest, abdomen, head and neck.

Professor Paul McMenamin, Director of the University’s Centre for Human Anatomy Education, said the simple and cost-effective anatomical kit would dramatically improve trainee doctors’ and other health professionals’ knowledge and could even contribute to the development of new surgical treatments.

Michelle Quayle is pictured with part of the ‘3D Printed Anatomy Series’ thought to be the first commercially available resource of its kind
Credit: Monash University

“For centuries cadavers bequested to medical schools have been used to teach students about human anatomy, a practice that continues today. However many medical schools report either a shortage of cadavers, or find their handling and storage too expensive as a result of strict regulations governing where cadavers can be dissected,” he said.

“Without the ability to look inside the body and see the muscles, tendons, ligaments, and blood vessels, it’s incredibly hard for students to understand human anatomy. We believe our version, which looks just like the real thing, will make a huge difference.”

The kit, which is set to go on sale later this year, could have particular impact in developing countries where cadavers aren’t readily available, or are prohibited for cultural or religious reasons.

“Even when cadavers are available, they’re often in short supply, are expensive and they can smell a bit unpleasant because of the embalming process. As a result some people don’t feel that comfortable working with them,” Professor McMenamin said.

“Our 3D printed series can be produced quickly and easily, and unlike cadavers they won’t deteriorate – so they are a cost-effective option too.”

After scanning real anatomical specimens with either a CT or a surface laser scanner, the body parts are 3D printed either in a plaster-like powder or in plastic, resulting in high resolution, accurate color reproductions. 

Printed skull
Credit: Monash University

“Radiographic imaging, such as CT, is a really sophisticated means of capturing information in very thin layers, almost like the pages of a book. By taking this data and making a 3D rendered model we can then color that model and convert that to a file format that the 3D printer uses to recreate, layer by layer, a three-dimensional body part to scale,” Professor McMenamin said.

The research team is currently negotiating with potential commercial partners.

Further details have been published online in the journal Anatomical Sciences Education.


Contacts and sources:
Monash University

Saturday, July 19, 2014

Crash Of MH17 Sparks UN Security Council Emergency Meeting

The apparent deliberate downing of a Malaysian passenger plane over eastern Ukraine highlights the need for an urgent resumption of a ceasefire and a serious effort to end the ongoing crisis, the United Nations political chief told an emergency meeting of the Security Council yesterday.

The UN Security Council holds a moment of silence in honor of the victims of crashed flight MH17.
UN Photo/Loey Felipe

Malaysia Airlines flight MH17, carrying 298 people, was en route from Amsterdam to Kuala Lumpur when it crashed on Thursday in eastern Ukraine, near the Russian border.

Under-Secretary-General for Political Affairs Jeffrey Feltman said that while the UN has at this point no independent verification of the circumstances regarding the tragic crash, Secretary-General Ban Ki-moon is alarmed at what seem to be “credible, numerous reports” that suggest that a sophisticated surface-to-air missile was used.

“The Secretary-General strongly condemns this apparently deliberate downing of a civilian aircraft,” said Mr. Feltman. “This horrifying incident serves as the starkest reminder of how dire the situation in eastern Ukraine has become – and how it affects countries and families well beyond Ukraine’s borders.”

A separate statement issued by Mr. Ban’s spokesperson said that “this horrifying incident must at the very least prompt a serious and sustained effort to end the fighting in Ukraine.” It also stressed the need for accountability for the tragedy.

Both the Secretary-General and the Security Council have called for an international investigation into the incident. The Council, in a press statement, also stressed the need for all parties to grant immediate access by investigators to the crash site.

Mr. Feltman said the UN is fully ready to cooperate, and it has been in touch with the UN International Civil Aviation Organization (ICAO), which has offered to Ukrainian officials its investigative capacity in order to put together an international team.

Among the casualties of the crash was a staff member of the World Health Organization (WHO), Glenn Thomas, who was on his way to an international AIDS conference in Australia. The Joint UN Programme on HIV/AIDS (UNAIDS) said in a statement that a number of other passengers on the flight were also on their way to participate in the conference.


Credit: UN Photo/Loey Felipe 

“The UNAIDS family is in deep shock. Our hearts go out to the families of all the victims of this tragic crash,” said Executive Director Michel Sidibé. “The deaths of so many committed people working against HIV will be a great loss for the AIDS response.”

On the Ukraine crisis, Mr. Feltman reported that following the 30 June announcement by President Petro Poroshenko of the end of the 10-day ceasefire and subsequent resumption of the security and law enforcement operation in the east, the fighting between Government forces and armed groups has intensified dangerously, resulting in numerous deaths.

According to the Ukrainian authorities, a number of towns, including notably the cities of Sloviansk and Kramatorsk, as well as various smaller villages in the Donetsk and Lugansk regions, have been returned to their control.

However, Mr. Feltman said, relentless fighting has continued particularly in and around the cities of Lugansk and Donetsk, where the armed groups appear to have consolidated their presence. Earlier this week, a fierce battle was also fought over the international airport in Lugansk that now appears under the Ukrainian Government’s control.

The situation on and around the border between Ukraine and Russia is of “particular concern,” he said, noting that, while it is impossible for the UN to independently verify these accounts, a number of fatal incidents as well as intense fighting have been reported in recent days.

“As the Secretary-General has reiterated on countless occasions, armed groups need to immediately disarm and stop engaging in unlawful and violent acts,” the official stated.

“At the same time, we continue to strongly urge the Ukrainian authorities to act with maximum restraint and to make every effort possible to ensure the protection of civilians caught in the fighting.”

While estimations of the total number of civilian casualties vary, the UN human rights office reports there have been approximately 500 casualties so far and 1,400 people injured. Also, the UN refugee agency estimates that the crisis has displaced some tens of thousands of people.

“Grievances can and must never justify endangering the lives of those one claims and aims to represent and protect,” Mr. Feltman stated. “As the fighting continues, we are, however, disconcerted by the apparent lack of tangible progress toward a political solution.

“A first, critical step would be the immediate resumption of a ceasefire,” he stated.

“Establishing a path to peace in Ukraine, as in areas of conflict elsewhere in the world, requires a concerted effort by national actors from across the political spectrum, backed by strong and unified support of the international community,” said Mr. Feltman, who is expected to return to Kiev and Moscow in the coming days in the spirit of the Secretary-General’s good offices.


Contacts and sources:
United Nations

Comet Churyumov-Gerasimenko – Neither Ball Nor Potato

Comets have irregular and rather potato-like shapes – this is a well-known fact. But the comet 67P/Churyumov-Gerasimenko, on which the Philae lander is scheduled to descend in November 2014, has an unexpected shape. The pictures acquired by the OSIRIS camera on board the European Space Agency (ESA) Rosetta spacecraft – just 14,000 kilometres from its target – show that the comet is a contact binary, consisting of two parts in close contact.

Credit: DLR

"This shape is most surprising," says comet researcher Ekkehard Kührt from the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR). For 30 years, the project leader has been studying these celestial bodies for scientific experiments on the probe and lander. 

"But it is not unlikely. Comets were formed by the collision of small building blocks far away from the Sun during the emergence of the Solar System." The effect of the comet's unusual shape on the landing cannot be estimated yet.

Fused together 4.5 billion years ago

Rosetta and the Philae lander are currently less than 10,000 kilometres away from their destination. So far, Churyumov-Gerasimenko has been an enigma for scientists: only recordings from a distance, such as those from the Hubble Space Telescope or the first images of OSIRIS as well as the navigation camera provide clues of what the orbiter and lander will encounter. 
Credit: DLR 

Previous observations estimated the comet to be about three by five kilometres in size. The fact that two clearly distinguishable parts make up Churyumov-Gerasimenko is a surprise. "The two blocks likely formed 4.5 billion years ago, collided at low speed, stuck to each other and have since been moving together," says Kührt.

 "Scientifically, it is now of course very interesting to find out whether the two components differ in their composition." If the two parts are from different regions, their structure might also differ.

Waiting for details

In the coming months, as the spacecraft get closer to their target, the scientists will learn more about the comet. "For the landing, it is especially important to have a detailed view of the comet and understand how the two parts are connected," says Koen Geurts, an engineer at the Lander Control Centre at DLR in Cologne. 

This information will be incorporated into the planning of the trajectory of Rosetta spacecraft – and its course and height in turn has an impact on the landing of Philae, as it is the first time that a lander touches down on a comet and performs in situ measurements. "So far, it looks as though there are large flat regions on the comet." 

The location where the two parts are connected will likely not be considered as the landing site. In addition to being a suitable, reasonably flat terrain, the landing site should also have a day-night cycle so that the Philae lander can cool down out of the sunlight and so that scientific research can be carried out under different conditions. 

Regular communication with the Rosetta spacecraft is necessary for the lander team to send the recorded data to Earth and empty the data storage. "These aspects are currently still hard to assess."

Rosetta is a European Space Agency mission with contributions from its Member States and NASA. Rosetta's Philae lander has been contributed by a consortium led by DLR, MPS, the French space agency, CNES (Centre National d’Études Spatiales), and the Italian space agency, ASI (Agenzia Spaziale Italiana).

The European Space Agency (ESA) Rosetta spacecraft and its lander Philae were around two million kilometers from their target comet in May, 67P/Churyumov-Gerasimenko when images acquired by the OSIRIS (Optical, Spectroscopic and Infrared Remote Imaging System) camera system could already show the comet awakening on its way towards the Sun, enveloped in a cloud of small dust particles.
Credit; DLR

Using these observations, the OSIRIS science team, which includes planetary researchers from the German Aerospace Center (Deutsches Zentrum für Luft- und Raumfahrt; DLR), have been able to determine the comet’s rotation period with additional precision – 12.4 hours. In August, Rosetta will arrive at the comet, and will deploy the Philae lander onto the comet’s surface in November – the first ever landing on a comet.

The sequence of images acquired by the OSIRIS camera system between 24 March and 4 May, during the flight towards Churyumov-Gerasimenko, reveal the expansion of the comet’s dusty veil, or coma. Although 67P is still more than 600 million kilometres from the Sun, its surface has already started to warm up, and, as a result, volatiles have begun to evaporate from its surface, carrying tiny dust particles with them. The images acquired in early May show that the comet’s gas and dust cloud has reached approximately 1300 kilometres into space. 

The comet nucleus has a diameter of about four kilometres. “It’s beginning to look like a real comet,” says Holger Sierks from the Max Planck Institute for Solar System Research (Max-Planck-Institut für Sonnensystemforschung; MPS), the OSIRIS Principal Investigator.

This image, acquired by the OSIRIS camera system on 30 April 2014, shows Comet 67P/Churyumov-Gerasimenko. The target of the Rosetta comet mission has a dust cloud formed around it, which stretches up to 1300 kilometres into space.

Credit: DLR

Unveiling the unknown

The OSIRIS team also revealed a new fact. Until now, comet researchers believed the rotation period of Churyumov-Gerasimenko to be 12.7 hours. Through observation and analysis of the changes in brightness of the comet, the research team was able to determine that the comet only takes 12.4 hours to rotate around its axis. 

“Knowing the exact rotation period of the comet is of vital importance, both for the optimal planning of the mission and scientific data gathering and for the interpretation of the acquired data,” said Stefano Mottola, who studies comets at the DLR Institute of Planetary Research and is a member of the OSIRIS team.

Any information obtained during the approach to the comet also helps to plan the manoeuvres required for the Rosetta spacecraft to enter orbit around the comet and the landing by Philae. One thing is certain – with the awakening of the comet, Rosetta and Philae will be able to study its coma and tail. The first manoeuvre to prepare the probe for its rendezvous with Churyumov-Gerasimenko in August has already been carried out. 

In May, the engineers and scientists were also able to breathe again – all the instruments on the spacecraft and lander have survived two and a half years of hibernation during their journey through space – they have all passed their ‘Health Check’. Eleven instruments are being carried on board the Rosetta orbiter and ten scientific experiments on the lander. For the first time ever, measurements will be conducted directly on the surface of a comet.


Contacts and sources:
 German Aerospace Center

Nature’s Strongest Super-Glue Comes Unstuck


Over a 150 years since it was first described by Darwin, scientists are finally uncovering the secrets behind the super strength of barnacle glue.

Still far better than anything we have been able to develop synthetically, barnacle glue – or cement - sticks to any surface, under any conditions.

But exactly how this superglue of superglues works has remained a mystery – until now.

An international team of scientists led by Newcastle University, UK, and funded by the US Office of Naval Research, have shown for the first time that barnacle larvae release an oily droplet to clear the water from surfaces before sticking down using a phosphoprotein adhesive.

Nauplius larva of Elminius modestus
Credit: Wikipedia

Publishing their findings this week in the prestigious academic journal Nature Communications, author Dr Nick Aldred says the findings could pave the way for the development of novel synthetic bioadhesives for use in medical implants and micro-electronics. The research will also be important in the production of new anti-fouling coatings for ships.

“It’s over 150 years since Darwin first described the cement glands of barnacle larvae and little work has been done since then,” says Dr Aldred, a research associate in the School of Marine Science and Technology at Newcastle University, one of the world’s leading institutions in this field of research.

“We’ve known for a while there are two components to the bioadhesive but until now, it was thought they behaved a bit like some of the synthetic glues - mixing before hardening. But that still left the question, how does the glue contact the surface in the first place if it is already covered with water? This is one of the key hurdles to developing glues for underwater applications.

“Advances in imaging techniques, such as 2-photon microscopy, have allowed us to observe the adhesion process and characterise the two components. We now know that these two substances play very different roles – one clearing water from the surface and the other cementing the barnacle down.

“The ocean is a complex mixture of dissolved ions, the pH varies significantly across geographical areas and, obviously, it’s wet. Yet despite these hostile conditions, barnacle glue is able to withstand the test of time.

“It’s an incredibly clever natural solution to this problem of how to deal with a water barrier on a surface it will change the way we think about developing bio-inspired adhesives that are safe and already optimised to work in conditions similar to those in the human body, as well as marine paints that stop barnacles from sticking.”

Barnacles have two larval stages – the nauplius and the cyprid. The nauplius, is common to most crustacea and it swims freely once it hatches out of the egg, feeding in the plankton.

The final larval stage, however, is the cyprid, which is unique to barnacles. It investigates surfaces, selecting one that provides suitable conditions for growth. Once it has decided to attach permanently, the cyprid releases its glue and cements itself to the surface where it will live out the rest of its days.

“The key here is the technology. With these new tools we are able to study processes in living tissues, as they happen. We can get compositional and molecular information by other methods, but they don't explain the mechanism. There's no substitute for seeing things with your own eyes. ” explains Dr Aldred.

“In the past, the strong lasers used for optically sectioning biological samples have typically killed the samples, but now technology allows us to study life processes exactly as they would happen in nature.”

The research will also be of interest to the shipping industry.

Biofouling – the accumulation of marine life on ship’s hulls – increases drag on ships and costs the global industry an estimated $7.5 billion a year in wasted fuel.

Barnacles on a ship's hull. 

Credit: Physical Chemistry Chemical Physics

Other implications include the movement of invasive species around the world and increased emission of greenhouse gases.


Contacts and sources:
School of Marine Science and Technology
Newcastle University


Citation: “Synergistic roles for lipids and proteins in the permanent adhesive of barnacle larvae.” N V Gohad, N Aldred, C M Hartshorn, Y Jong Lee, M T Cicerone, B Orihuela, A S Clare, D Rittschof and A S Mount. Nature Communications July 2014

New Global Geologic Map Of Mars

A new global geologic map of Mars –the most thorough representation of the "Red Planet's" surface – has been published by the U.S. Geological Survey. This map provides a framework for continued scientific investigation of Mars as the long-range target for human space exploration.

This new global geologic map of Mars depicts the most thorough representation of the “Red Planet’s” surface. This map provides a framework for continued scientific investigation of Mars as the long-range target for human space exploration
Credit: USGS

The new map brings together observations and scientific findings from four orbiting spacecraft that have been acquiring data for more than 16 years. The result is an updated understanding of the geologic history of the surface of Mars – the solar system’s most Earth-like planet and the only other one in our Sun’s “habitable zone.” The new geologic map of Mars is available for download online.

This new global geologic map of Mars depicts the most thorough representation of the "Red Planet's" surface. This map provides a framework for continued scientific investigation of Mars as the long-range target for human space exploration.

Credit: U.S. Geological Survey (USGS)

For hundreds of years, geologic maps have helped drive scientific thought. This new global geologic map of Mars, as well as the recent global geologic maps of Jupiter’s moons Ganymede and Io, also illustrates the overall importance of geologic mapping as an essential tool for the exploration of the solar system.

View of the northern part of the western hemisphere of Mars. Left half shows a color elevation, shaded relief view highlighting the immense shields of the Tharsis rise. Right half shows a true-color view of the vast Valles Marineris and Kasei Valles canyon systems, which connect to the dark basin of Chryse Planitia at upper right.
Image data from NASA

"Spacecraft exploration of Mars over the past couple decades has greatly improved our understanding of what geologic materials, events and processes shaped its surface," said USGS scientist and lead author, Dr. Kenneth Tanaka. “The new geologic map brings this research together into a holistic context that helps to illuminate key relationships in space and time, providing information to generate and test new hypotheses.”

The USGS-led mapping effort reveals that the Martian surface is generally older than previously thought. Three times as much surface area dates to the first major geologic time period - the Early Noachian Epoch - than was previously mapped. This timeframe is the earliest part of the Noachian Period, which ranges from about 4.1 to about 3.7 billion years ago, and was characterized by high rates of meteorite impacts, widespread erosion of the Martian surface and the likely presence of abundant surface water.

The map also confirms previous work that suggests Mars had been geologically active until the present day. There is evidence that major changes in Mars’ global climate supported the temporary presence of surface water and near-surface groundwater and ice. These changes were likely responsible for many of the major shifts in the environments where Martian rocks were formed and subsequently eroded. This new map will serve as a key reference for the origin, age and historic change of geological materials anywhere on Mars.

"Findings from the map will enable researchers to evaluate potential landing sites for future Mars missions that may contribute to further understanding of the planet’s history," said USGS Acting Director Suzette Kimball. "The new Mars global geologic map will provide geologic context for regional and local scientific investigations for many years to come."

The Martian surface has been the subject of scientific observation since the 1600s, first by Earth-based telescopes, and later by fly-by missions and orbiting spacecraft. The Mariner 9 and Viking Orbiter missions produced the first planet-wide views of Mars’ surface, enabling publication of the first global geologic maps (in 1978 and 1986-87, respectively) of a planetary surface other than the Earth and the Moon. A new generation of sophisticated scientific instruments flown on the Mars Global Surveyor, Mars Odyssey, Mars Express and Mars Reconnaissance Orbiter spacecraft has provided diverse, high quality data sets that enable more sophisticated remapping of the global-scale geology of Mars.

The production of planetary cartographic products has been a focal point of research at the USGS Astrogeology Science Center since its inception in the early 1960s. USGS began producing planetary maps in support of the Apollo Moon landings, and continues to help establish a framework for integrating and comparing past and future studies of extraterrestrial surfaces. In many cases, these planetary geologic maps show that, despite the many differences between bodies in our solar system, there are many notable similarities that link the evolution and fate of our planetary system together.

The project was funded by NASA through its Planetary Geology and Geophysics Program.

The mission of the USGS Astrogeology Science Center is to serve the Nation, the international planetary science community, and the general public’s pursuit of new knowledge of our solar system. The Team’s vision is to be a national resource for the integration of planetary geosciences, cartography, and remote sensing. As explorers and surveyors, with a unique heritage of proven expertise and international leadership, USGS astrogeologists enable the ongoing successful investigation of the solar system for humankind. For more information, visit Astrogeology Science Center

See the complete map at http://pubs.usgs.gov/sim/3292/pdf/sim3292_map.pdf  with all annotations.


Contacts and sources:
Jennifer LaVista
U.S. Geological Survey

New Earthquake Map: 42 States at Risk; 16 States at High Risk

To help make the best decisions to protect communities from earthquakes, new USGS maps display how intense ground shaking could be across the nation.

The USGS recently updated their U.S. National Seismic Hazard Maps, which reflect the best and most current understanding of where future earthquakes will occur, how often they will occur, and how hard the ground will likely shake as a result.

42 States at Risk; 16 States at High Risk

2014 USGS National Seismic Hazard Map, displaying intensity of potential ground shaking from an earthquake in 50 years (which is the typical lifetime of a building).

Credit: USGS

While all states have some potential for earthquakes, 42 of the 50 states have a reasonable chance of experiencing damaging ground shaking from an earthquake in 50 years (the typical lifetime of a building). Scientists also conclude that 16 states have a relatively high likelihood of experiencing damaging ground shaking. These states have historically experienced earthquakes with a magnitude 6 or greater.

The hazard is especially high along the west coast, intermountain west, and in several active regions of the central and eastern U.S., such as near New Madrid, MO, and near Charleston, SC. The 16 states at highest risk are Alaska, Arkansas, California, Hawaii, Idaho, Illinois, Kentucky, Missouri, Montana, Nevada, Oregon, South Carolina, Tennessee, Utah, Washington, and Wyoming.

While these overarching conclusions of the national-level hazard are similar to those of the previous maps released in 2008, details and estimates differ for many cities and states. Several areas have been identified as being capable of having the potential for larger and more powerful earthquakes than previously thought due to more data and updated earthquake models. The most prominent changes are discussed below.

Informed Decisions Based on the Maps

With an understanding of potential ground shaking levels, various risk analyses can be calculated by considering factors like population levels, building exposure, and building construction practices. This is used for establishing building codes, and in the analysis of seismic risk for key structures. This can also help in determining insurance rates, emergency preparedness plans, and private property decisions such as re-evaluating one’s home and making it more resilient.

These maps are part of USGS contributions to the National Earthquake Hazards Reduction Program (NEHRP), which is a congressionally-established partnership of four federal agencies with the purpose of reducing risks to life and property in the U.S. that result from earthquakes. The contributing agencies are the USGS, Federal Emergency Management Agency (FEMA), National Institute of Standards and Technology, and National Science Foundation (NSF). As an example of the collaboration, the hazards identified in the USGS maps underlie FEMA-sponsored seismic design provisions that are incorporated into building codes adopted by states and localities. The maps also reflect investments in research by academic and other scientists supported by grants from the USGS and the NSF.

“The standards for seismic safety in building codes are directly based upon USGS assessments of potential ground shaking from earthquakes, and have been for years,” said Jim Harris, a member and former chair of the Provisions Update Committee of the Building Seismic Safety Council.

“The committees preparing those standards welcome this updated USGS information as a basis for making decisions and continuing to ensure the most stable and secure construction.”

Key Updates

East Coast

The eastern U.S. has the potential for larger and more damaging earthquakes than considered in previous maps and assessments. As one example, scientists learned a lot following the magnitude 5.8 earthquake that struck Virginia in 2011. It was among the largest earthquakes to occur along the east coast in the last century, and helped determine that even larger events are possible. Estimates of earthquake hazards near Charleston, SC, have also gone up due to the assessment of earthquakes in the state.

In New York City, the maps indicate a slightly lower hazard for tall buildings than previously thought (but still a hazard nonetheless). Scientists estimated a lower likelihood for slow shaking from an earthquake near the city. Slow shaking is likely to cause more damage to tall structures in contrast, compared to fast shaking which is more likely to impact shorter structures.

Central U.S.

The New Madrid Seismic Zone has been identified to have a larger range of potential earthquake magnitudes and locations than previously identified. This is a result of a range of new research, part of which was recently compiled by the Nuclear Regulatory Commission.

West Coast

In California, earthquake hazard extends over a wider area than previously thought. Most notably, faults were recently discovered, raising earthquake hazard estimates for San Jose, Vallejo and San Diego. On the other hand, new insights on faults and rupture processes reduced earthquake hazard estimates for Irvine, Santa Barbara and Oakland. Hazard increased in some parts of the San Francisco Bay Area and Los Angeles region and decreased in other parts. These updates were from the new Uniform California Earthquake Rupture Forecast Model, which incorporates many more potential fault ruptures than did previous assessments. Recent earthquakes in Alaska, Mexico and New Zealand taught scientists more about complex ruptures and how faults can link together. This insight was applied to California for which approximately 250,000 potential complex ruptures were modeled.

New research on the Cascadia Subduction Zone resulted in increased estimates of earthquake magnitude up to magnitude 9.3. Deep-sea cores were collected that show evidence within the sea-floor sediments of large earthquake-generated mudflows. Earthquake shaking estimates were also increased following abundant data gathered from the magnitude 9.0 earthquake in Tohoku, Japan in 2011 and the magnitude 8.2 earthquake offshore of Chile in 2014, as those events ruptured along subduction zones similar to the Pacific Northwest zone.

Damage to the Washington National Cathedral in DC from the earthquake in Virginia on August 23, 2011.
 Photo Credit: William Leith, USGS

In Washington, scientists incorporated new knowledge of the Tacoma Fault into the maps and identified changes to the geometry of the Whidbey Island fault in the northern Puget Sound. Earthquake hazard also increased for Las Vegas because of new science. In Utah, scientists dug trenches to study prehistoric earthquakes along the Wasatch Fault. While the overall seismic hazard didn’t change significantly, detailed changes were made to the fault models in this region and robust data were acquired to hone the assessments. This is valuable since approximately 75% of Utah’s population, including the residents of Salt Lake City, lives near this fault.

The magnitude 7.9 earthquake in Wenchuan, China in 2008 provided many new records of shaking that are very similar to anticipated future earthquakes in the western U.S., as the fault structures are similar. Previously, scientists did not have nearly as many shaking records from earthquakes of this size.

Induced Earthquakes … Research Underway

Some states have experienced increased seismicity in the past few years that may be associated with human activities such as the disposal of wastewater in deep wells.

One specific focus for the future is including an additional layer to these earthquake hazard maps to account for recent potentially triggered earthquakes that occur near some wastewater disposal wells. Injection-induced earthquakes are challenging to incorporate into hazard models because they may not behave like natural earthquakes and their rates change based on man-made activities.

You Can’t Plan If …

“USGS earthquake science is vital because you can’t plan for earthquakes if you don’t know what you are planning for,” said Mark Petersen, Chief of the USGS National Seismic Hazard Mapping Project. “Our nation’s population and exposure to large earthquakes has grown tremendously in recent years. The cost of inaction in planning for future earthquakes and other natural disasters can be very high, as demonstrated by several recent damaging events across the globe. It is important to understand the threat you face from earthquakes at home and the hazards for the places you might visit. The USGS is dedicated to applying the best available science in developing reliable products useful for reducing the earthquake risk across the U.S.”

Start with USGS Science

The USGS is the only federal agency with responsibility for recording and reporting earthquake activity nationwide and providing a seismic hazard assessment. The USGS regularly updates the national seismic hazard models and maps, typically every 6 years, in sync with the building code updates. The 2014 update focuses on the conterminous U.S. Maps are also available for Alaska (last updated in 2007); Hawaii (1998); Puerto Rico (2003); Guam and Marianna Islands (2012); and American Samoa (2012).


Contacts and sources:
By Jessica Robertson and Mark Petersen
USGS

Documentation for the 2014 Update of the United States National Seismic Hazard Maps
By Mark D. Petersen, Morgan P. Moschetti, Peter M. Powers, Charles S. Mueller, Kathleen M. Haller, Arthur D. Frankel, Yuehua Zeng, Sanaz Rezaeian, Stephen C. Harmsen, Oliver S. Boyd, Ned Field, Rui Chen, Kenneth S. Rukstales, Nico Luco, Russell L. Wheeler, Robert A. Williams, and Anna H. Olsen Report PDF (113 MB)

The Bend In The Appalachian Mountain Chain Is Finally Explained

The 1500 mile Appalachian mountain chain runs along a nearly straight line from Alabama to Newfoundland—except for a curious bend in Pennsylvania and New York State. Researchers from the College of New Jersey and the University of Rochester now know what caused that bend—a dense, underground block of rigid, volcanic rock forced the chain to shift eastward as it was forming millions of years ago.

A dense, underground block of volcanic rock (shown in red) helped shape the well-known bend in the Appalachian mountain range.
Credit: Graphic by Michael Osadciw/University of Rochester.

According to Cindy Ebinger, a professor of earth and environmental sciences at the University of Rochester, scientists had previously known about the volcanic rock structure under the Appalachians. "What we didn't understand was the size of the structure or its implications for mountain-building processes," she said.

The findings have been published in the journal Earth and Planetary Science Letters.

When the North American and African continental plates collided more than 300 million years ago, the North American plate began folding and thrusting upwards as it was pushed westward into the dense underground rock structure—in what is now the northeastern United States. The dense rock created a barricade, forcing the Appalachian mountain range to spring up with its characteristic bend.

The research team—which also included Margaret Benoit, an associate professor of physics at the College of New Jersey, and graduate student Melanie Crampton at the College of New Jersey—studied data collected by the Earthscope project, which is funded by the National Science Foundation. Earthscope makes use of 136 GPS receivers and an array of 400 portable seismometers deployed in the northeast United States to measure ground movement.

Benoit and Ebinger also made use of the North American Gravity Database, a compilation of open-source data from the U.S., Canada, and Mexico. The database, started two decades ago, contains measurements of the gravitational pull over the North American terrain. Most people assume that gravity has a constant value, but when gravity is experimentally measured, it changes from place to place due to variations in the density and thickness of Earth's rock layers. Certain parts of the Earth are denser than others, causing the gravitational pull to be slightly greater in those places.

Data on the changes in gravitational pull and seismic velocity together allowed the researchers to determine the density of the underground structure and conclude that it is volcanic in origin, with dimensions of 450 kilometers by 100 kilometers. This information, along with data from the Earthscope project ultimately helped the researchers to model how the bend was formed.

Ebinger called the research project a "foundation study" that will improve scientists' understanding of the Earth's underlying structures. As an example, Ebinger said their findings could provide useful information in the debate over hydraulic fracturing—popularly known is hydrofracking—in New York State.

Hydrofracking is a mining technique used to extract natural gas from deep in the earth. It involves drilling horizontally into shale formations, then injecting the rock with sand, water, and a cocktail of chemicals to free the trapped gas for removal. The region just west of the Appalachian Basin—the Marcellus Shale formation—is rich in natural gas reserves and is being considered for development by drilling companies.

Research funding was provided by NASA and the National Science Foundation.

The paper can be found here: http://www.sciencedirect.com/science/article/pii/S0012821X14002246.




Contacts and sources:
Leonor Sierra
University of Rochester

Friday, July 18, 2014

Preventing Foodborne Illness, Naturally -- With Cinnamon


Essential oil kills several strains of E. coli.


Seeking ways to prevent some of the most serious foodborne illnesses caused by pathogenic bacteria, two Washington State University scientists have found promise in an ancient but common cooking spice: cinnamon.

Cinnamomum cassia oil has been shown to kill certain strains of E. coli bacteria.
Credit: Robert Hubner, WSU Photo Services

Recent findings published in Food Control journal online suggest Cinnamomum cassia oil can work effectively as a natural antibacterial agent in the food industry. The study results add to a body of knowledge that will help improve food safety and reduce or eliminate cases of food poisoning and related deaths.

In the study, the essential oil killed several strains of Shiga toxin-producing Escherichia coli (E. coli), known to the U.S. Centers for Disease Control and Prevention as "non-O157 STEC." The study looked at the top six strains of non-O157 STEC, said co-author Lina Sheng, a graduate student in the School of Food Science.

The cinnamon cassia oil is effective in low concentrations, she said – about 10 drops diluted in a liter of water killed the bacteria within 24 hours.
 
This image depicts researchers at the WSU School of Food Science.
Credit: Robert Hubner, WSU Photo Services

Demand for natural food additives

Rising health concerns about chemical additives have strengthened demand for natural food additives, said co-author Meijun Zhu, an assistant professor in the School of Food Science.

"Our focus is on exploring plant-derived natural food bioactive compounds as antimicrobials to control foodborne pathogens, in order to ensure safety of fresh produce," she said.

Sheng said about 110,000 cases of illness are caused annually by non-O157 STEC.

The U.S. Department of Agriculture Food Safety and Inspection Service has a "zero tolerance" policy for the CDC top six non-O157 STECs in raw ground beef and trimmings, indicating any raw non-intact beef products containing these pathogens will be considered adulterated. This has led Zhu and Sheng to include the beef industry in the large-scale application of their findings on cinnamon.

"The oil can be incorporated into films and coatings for packaging both meat and fresh produce," Sheng said. "It can also be added into the washing step of meat, fruits or vegetables to eliminate microorganisms."

Cassia cinnamon is produced primarily in Indonesia and has a stronger smell than the other common cinnamon variety, Ceylon.

In addition to Cinnamomum cassia oil, Sheng plans to take a look at another natural source to kill bacteria. She and her coworkers will study the potential of dandelions to inhibit bacteria related to bovine mastitis, an infection in the mammary glands of dairy cows.

The article, "Inhibitory effect of Cinnamomum cassia oil on non-O157 Shiga toxin-producing Escherichia coli," will be published in the print version of Food Control in December 2014.


Contacts and sources:
Meijun Zhu
Washington State University

New Study Shows How Existing Cropland Could Feed Billions More

A new report pinpoints key food systems 'leverage points' that hold the greatest the potential to boost global food security and protect the environment.

Feeding a growing human population without increasing stresses on Earth's strained land and water resources may seem like an impossible challenge. But according to a new report by researchers at the University of Minnesota's Institute on the Environment, focusing efforts to improve food systems on a few specific regions, crops and actions could make it possible to both meet the basic needs of 3 billion more people and decrease agriculture's environmental footprint.

Credit:  University of Minnesota's Institute on the Environment

The report, published today in Science, focuses on 17 key crops that produce 86 percent of the world's crop calories and account for most irrigation and fertilizer consumption on a global scale. It proposes a set of key actions in three broad areas that that have the greatest potential for reducing the adverse environmental impacts of agriculture and boosting our ability meet global food needs. For each, it identifies specific "leverage points" where nongovernmental organizations, foundations, governments, businesses and citizens can target food-security efforts for the greatest impact. The biggest opportunities cluster in six countries — China, India, U.S., Brazil, Indonesia and Pakistan — along with Europe.

"This paper represents an important next step beyond previous studies that have broadly outlined strategies for sustainably feeding people," said lead author Paul West, co-director of the Institute on the Environment's Global Landscapes Initiative. "By pointing out specifically what we can do and where, it gives funders and policy makers the information they need to target their activities for the greatest good."

The major areas of opportunity and key leverage points for improving the efficiency and sustainability of global food production are:

1. Produce more food on existing land. Previous research has detected the presence of a dramatic agricultural "yield gap" — difference between potential and actual crop yield — in many parts of the world. This study found that closing even 50 percent of the gap in regions with the widest gaps could provide enough calories to feed 850 million people. Nearly half of the potential gains are in Africa, with most of the rest represented by Asia and Eastern Europe.

2. Grow crops more efficiently. The study identified where major opportunities exist to reduce climate impacts and improve the efficiency with which we use nutrients and water to grow crops.

Agriculture is responsible for 20 to 35 percent of global greenhouse gas emissions, largely in the form of carbon dioxide from tropical deforestation, methane from livestock and rice growing, and nitrous oxide from crop fertilization. The study found that the biggest opportunities for reducing greenhouse gas production are in Brazil and Indonesia for deforestation; China and India for rice production; and China, India and the United States for crop fertilization.

With respect to nutrient use, the study found that worldwide, 60 percent of nitrogen and nearly 50 percent of phosphorus applications exceed what crops need to grow. China, India and the U.S. — and three crops, rice, wheat and corn — are the biggest sources of excess nutrient use worldwide, so offer the greatest opportunity for improvement.

With respect to water, rice and wheat are the crops that create the most demand for irrigation worldwide, and India, Pakistan, China and the U.S. account for the bulk of irrigation water use in water-limited areas. Boosting crop water use efficiency, the researchers found, could reduce water demand 8 to 15 percent without compromising food production.

3. Use crops more efficiently. The third major category of opportunities characterized for boosting food production and environmental protection relate to making more crop calories available for human consumption by shifting crops from livestock to humans and reducing food waste.

The crop calories we currently feed to animals are sufficient to meet the calorie needs of 4 billion people. The study noted that the U.S., China and Western Europe account for the bulk of this "diet gap," with corn the main crop being diverted to animal feed. Although cultural preferences and politics limit the ability to change this picture, the authors note that shifting crops from animal feed to human food could serve as a "safety net" when weather or pests create shortages.

In addition, some 30 to 50 percent of food is wasted worldwide. Particularly significant is the impact of animal products: The loss of 1 kilogram of boneless beef has the same effect as wasting 24 kilograms of wheat due to inefficiencies in converting grain to meat. The authors illustrate how food waste in the U.S., China and India affect available calories, noting that reducing waste in these three countries alone could yield food for more than 400 million people.

"Sustainably feeding people today and in the future is one of humanity's grand challenges. Agriculture is the main source of water use, greenhouse gas emissions, and habitat loss, yet we need to grow more food," West said. "Fortunately, the opportunities to have a global impact and move in the right direction are clustered. By focusing on areas, crops and practices with the most to be gained, companies, governments, NGOs and others can ensure that their efforts are being targeted in a way that best accomplishes the common and critically important goal of feeding the world while protecting the environment. Of course, while calories are a key measure of improving food security, nutrition, access and cultural preferences must also be addressed. But the need to boost food security is high. So let's do it."





Contacts and sources:
Todd Reubold
University of Minnesota

The Mystery Behind Starling Flocks Explained

The mystery behind the movements of flocking starlings could be explained by the areas of light and dark created as they fly, new research suggests.

The research, conducted by the University of Warwick and published in the journal PNAS, found that flocking starlings aim to maintain an optimum density at which they can gather data on their surroundings. This occurs when they can see light through the flock at many angles, a state known as marginal opacity. The subsequent pattern of light and dark, formed as the birds attempt to achieve the necessary density, is what provides vital information to individual birds within the flock.



The dynamic pattern of light and dark is created by birds within the flock altering the positions and angles at which they fly, causing a change in the amount of light let into the flock. The researchers observed that it was always possible to see areas of light coming through the flock, providing the initial insight that the changing patterns of light and dark had a role to play in the flock’s movement.

Agent based simulation for a flock of starlings under predation from a hawk. Using the Hybrid Projection Model, developed by Daniel Pearce.

This insight led to the development of a computer model in which individual birds with simulated intelligence were attracted to the areas in the flock that could provide the most information on the rest of the flock[1]. When each simulated bird was attracted to the areas in the virtual flock that can provide the most information the result was a cohesive swarm.

The Warwick team then applied the model’s findings to flocks in the wild and established that there was a strong correlation between movements of the virtual and natural birds.


“An individual starling within a flock can see in front of them areas of light and dark created by other birds, forming a dynamic and changing silhouette”, says lead researcher Daniel Pearce from the University’s Department of Physics. “Our research ascertained that the silhouettes we external observers witness were a result of large flocks self-organising to achieve a marginally opaque state at which a bird can still see some of the light sky through gaps in the flock and gather information from other birds.

“When we observe a flock of starlings we are actually seeing a 2D projection of a dynamic, changing 3D environment. By developing this model we have been able to simulate this environment and see that when each bird is attracted to the areas in the flock that can provide the most information the result is a cohesive swarm that resembles a large flock of starlings in the wild”, comments Mr Pearce.

It had previously been thought that co-ordination of a flock was achieved through birds interacting only with neighbouring members but, argues Professor Emeritus and paper co-author George Rowlands, the new research marks “a paradigm shift in our understanding of how birds organise within a flock as it shows that the local interactions between birds are alone insufficient to explain large-scale flock organisation”.



Contacts and sources:
Tom Frew University of Warwick

Citation: Role of projection in the control of bird flocks.  D. J. G. Pearce, A. M. Miller, G. Rowlands, M. S. Turner.  Proceedings of the National Academy of Sciences, 2014; DOI: 10.1073/pnas.1402202111

Peering Deep Into The Interior Of Giant Planets

Lawrence Livermore scientists for the first time have experimentally re-created the conditions that exist deep inside giant planets, such as Jupiter, Uranus and many of the planets recently discovered outside our solar system.

The interior of the target chamber at the National Ignition Facility at Lawrence Livermore National Laboratory. The object entering from the left is the target positioner, on which a millimeter-scale target is mounted. Researchers recently used NIF to study the interior state of giant planets. 
Image by Damien Jemison/LLNL

Researchers can now re-create and accurately measure material properties that control how these planets evolve over time, information essential for understanding how these massive objects form. This study focused on carbon, the fourth most abundant element in the cosmos (after hydrogen, helium and oxygen), which has an important role in many types of planets within and outside our solar system. The research appears in the July 17 edition of the journal, Nature.

Using the largest laser in the world, the National Ignition Facility at Lawrence Livermore National Laboratory, teams from the Laboratory, University of California, Berkeley and Princeton University squeezed samples to 50 million times Earth's atmospheric pressure, which is comparable to the pressures at the center of Jupiter and Saturn. Of the 192 lasers at NIF, the team used 176 with exquisitely shaped energy versus time to produce a pressure wave that compressed the material for a short period of time. The sample -- diamond -- is vaporized in less than 10 billionths of a second.

Though diamond is the least compressible material known, the researchers were able to compress it to an unprecedented density greater than lead at ambient conditions.

"The experimental techniques developed here provide a new capability to experimentally reproduce pressure-temperature conditions deep in planetary interiors," said Ray Smith, LLNL physicist and lead author of the paper.


Such pressures have been reached before, but only with shock waves that also create high temperatures -- hundreds of thousands of degrees or more -- that are not realistic for planetary interiors. The technical challenge was keeping temperatures low enough to be relevant to planets. The problem is similar to moving a plow slowly enough to push sand forward without building it up in height. This was accomplished by carefully tuning the rate at which the laser intensity changes with time.

"This new ability to explore matter at atomic scale pressures, where extrapolations of earlier shock and static data become unreliable, provides new constraints for dense matter theories and planet evolution models," said Rip Collins, another Lawrence Livermore physicist on the team.

The data described in this work are among the first tests for predictions made in the early days of quantum mechanics, more than 80 years ago, which are routinely used to describe matter at the center of planets and stars. While agreement between these new data and theory are good, there are important differences discovered, suggesting potential hidden treasures in the properties of diamond compressed to such extremes. Future experiments on NIF are focused on further unlocking these mysteries.


Contacts and sources:
Anne Stark
DOE/Lawrence Livermore National Laboratory

The Secret To Twisting Light At Will

Scientists at The Australian National University (ANU) have uncovered the secret to twisting light at will. It is the latest step in the development of photonics, the faster, more compact and less carbon-hungry successor to electronics.

A random find in the washing basket led the team to create the latest in a new breed of materials known as metamaterials. These artificial materials show extraordinary properties quite unlike natural materials.

"Our material can put a twist into light – that is, rotate its polarisation – orders of magnitude more strongly than natural materials," said lead author Mingkai Liu, a PhD student at the ANU Research School of Physics and Engineering (RSPE).

This image depicts David Powell twisting light.
Credit: ANU

"And we can switch the effect on and off directly with light," said Mr Liu .

Electronics is estimated to account for two per cent of the global carbon footprint, a figure which photonics has the potential to reduce significantly. Already light carried by fibre optics, has replaced electricity for carrying signals over long distances. The next step is to develop photonic analogues of electronic computer chips, by actively controlling the properties of light, such as its polarisation.

The ability of a material to rotate polarisation, as in this experiment, springs from the asymmetry of a molecule. It occurs in natural minerals and substances; for example, sugar is asymmetric and so polarisation rotation can be used to measure sugar concentrations, which is useful in diabetes research.

However the remarkable properties of this artificial material might first be put to use in the budding photonics industry, suggests co-author Dr David Powell, also from RSPE.

"It's another completely new tool in the toolbox for processing light," he says. "Thin slices of these materials can replace bulky collections of lenses and mirrors. This miniaturisation could lead to the creation of more compact opto-electronic devices, such as a light-based version of the electronic transistor."

The metamaterials are formed from a pattern of tiny metal shapes, dubbed meta-atoms. To obtain optical rotation Mr Liu and his colleagues used pairs of C-shaped meta-atoms, one suspended above the other by a fine wire. When light is shined on to the pair of meta-atoms the top one rotates, making the system asymmetric.

"The high responsiveness of the system comes because it is very easy to make something hanging rotate," says Mr Liu.

"The idea came to me when I found a piece of wire in my washing one day."

The fact that the team's meta-atoms move when light shines on them adds a new dimension, he says.

"Because light affects the symmetry of our system, you can tune your material's response simply by shining a light beam on it. Tunability of a metamaterial is an important step towards building devices based on these artificial materials," he says.

The work is published in Nature Communications.



Contacts and sources:
Philip Dooley
Australian National University

Signs Of Life On Mars


Ancient fossilized soils potentially found in deep inside an impact crater suggest microbial life.

Soil deep in a crater dating to some 3.7 billion years ago contains evidence that Mars was once much warmer and wetter, says University of Oregon geologist Gregory Retallack, based on images and data captured by the rover Curiosity.

Geologist Gregory Retallack, based on images and data gathered by the Mars rover Curiosity, believes 3.7 billion-year-old rocks at the bottom of the Gale impact crater contain fossilized soil. Such soil, called paleosols, have been found in the oldest Earth soils and their presence suggests microbial life was likely.
Credit: Photo by Tim Christie

NASA rovers have shown Martian landscapes littered with loose rocks from impacts or layered by catastrophic floods, rather than the smooth contours of soils that soften landscapes on Earth. However, recent images from Curiosity from the impact Gale Crater, Retallack said, reveal Earth-like soil profiles with cracked surfaces lined with sulfate, ellipsoidal hollows and concentrations of sulfate comparable with soils in Antarctic Dry Valleys and Chile's Atacama Desert.


His analyses appear in a paper placed online this week by the journal Geology in advance of print in the September issue. Retallack, the paper's lone author, studied mineral and chemical data published by researchers closely tied with the Curiosity mission. Retallack, professor of geological sciences and co-director of paleontology research at the UO Museum of Natural and Cultural History, is an internationally known expert on the recognition of paleosols -- ancient fossilized soils contained in rocks.

"The pictures were the first clue, but then all the data really nailed it," Retallack said. "The key to this discovery has been the superb chemical and mineral analytical capability of the Curiosity Rover, which is an order of magnitude improvement over earlier generations of rovers. The new data show clear chemical weathering trends, and clay accumulation at the expense of the mineral olivine, as expected in soils on Earth. Phosphorus depletion within the profiles is especially tantalizing, because it attributed to microbial activity on Earth."

The ancient soils, he said, do not prove that Mars once contained life, but they do add to growing evidence that an early wetter and warmer Mars was more habitable than the planet has been in the past 3 billion years.

Curiosity rover is now exploring topographically higher and geologically younger layers within the crater, where the soils appear less conducive to life. For a record of older life and soils on Mars, Retallack said, new missions will be needed to explore older and more clayey terrains.

Surface cracks in the deeply buried soils suggest typical soil clods. Vesicular hollows, or rounded holes, and sulfate concentrations, he said, are both features of desert soils on Earth.

"None of these features is seen in younger surface soils of Mars," Retallack said. "The exploration of Mars, like that of other planetary bodies, commonly turns up unexpected discoveries, but it is equally unexpected to discover such familiar ground."

The newly discovered soils provide more benign and habitable soil conditions than known before on Mars. Their dating to 3.7 billion years ago, he noted, puts them into a time of transition from "an early benign water cycle on Mars to the acidic and arid Mars of today." Life on Earth is believed to have emerged and began diversifying about 3.5 million years ago, but some scientists have theorized that potential evidence that might take life on Earth farther back was destroyed by plate tectonics, which did not occur on Mars.

In an email, Malcolm Walter of the Australian Centre for Astrobiology, who was not involved in the research, said the potential discovery of these fossilized soils in the Gale Crater dramatically increases the possibility that Mars has microbes. "There is a real possibility that there is or was life on Mars," he wrote.
 
Retallack noted that Steven Benner of the Westheimer Institute of Science and Technology in Florida has speculated that life is more likely to have originated on a soil planet like Mars than a water planet like Earth. In an email, Benner wrote that Retallack's paper "shows not only soils that might be direct products of an early Martian life, but also the wet-dry cycles that many models require for the emergence of life."


Contacts and sources:
Jim Barlow
University of Oregon

Scientists Identify Gene That Plays A Surprising Role In Combating Aging

It is something of an eternal question: Can we slow or even reverse the aging process? Even though genetic manipulations can, in fact, alter some cellular dynamics, little is known about the mechanisms of the aging process in living organisms.

Now scientists from the Florida campus of The Scripps Research Institute (TSRI) have found in animal models that a single gene plays a surprising role in aging that can be detected early on in development, a discovery that could point toward the possibility of one day using therapeutics, even some commonly used ones, to manipulate the aging process itself.

“We believe that a previously uncharacterized developmental gene known as Spns1 may mediate the aging process,” said Shuji Kishi, a TSRI assistant professor who led the study, published recently by the journal PLOS Genetics. “Even a partial loss of Spns1 function can speed aging.”

Shuji Kishi, MD, PhD, is an assistant professor at The Scripps Research Institute, Florida campus. 

Photo courtesy of The Scripps Research Institute

Using various genetic approaches to disturb Spns1 during the embryonic and/or larval stages of zebrafish—which have emerged as a powerful system to study diseases associated with development and aging—the scientists were able to produce some models with a shortened life span, others that lived long lives.

While most studies of “senescence”—declines in a cell's power of division and growth—have focused on later stages of life, the study is intriguing in exploring this phenomenon in early stages. “Mutations to Spns1 both disturbs developmental senescence and badly affects the long-term bio-chronological aging process,” Kishi said.

The new study shows that Spns1, in conjunction with another pair of tumor suppressor genes, beclin 1 and p53 can, influences developmental senescence through two differential mechanisms: the Spns1 defect was enhanced by Beclin 1 but suppressed by ‘basal p53.’ In addition to affecting senescence, Spns1 impedes autophagy, the process whereby cells remove unwanted or destructive proteins and balance energy needs during various life stages.

Building on their insights from the study, Kishi and his colleagues noted in the future therapeutics might be able to influence aging through Spns1. He noted one commonly used antacid, Prilosec, has been shown to temporarily suppress autophagic abnormality and senescence observed in the Spns1 deficiency.


Contacts and sources:
The Scripps Research Institute


Citation: PLOS Genetics, Published: June 26, 2014DOI: 10.1371/journal.pgen.1004409. Tomoyuki Sasaki; Shanshan Lian; Jie Qi; Peter E. Bayliss; Christopher E. Carr; Jennifer L. Johnson; Sujay Guha; Patrick Kobler; Sergio D. Catz; Matthew Gill; Kailiang Jia; Daniel J. Klionsky,6; Shuji Kishi, “Aberrant Autolysosomal Regulation Is Linked to The Induction of Embryonic Senescence: Differential Roles of Beclin 1 and p53 in Vertebrate Spns1 Deficiency.”