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Thursday, August 29, 2013

Oldest Solar Twin Identified

An international team led by astronomers in Brazil has used ESO’s Very Large Telescope to identify and study the oldest solar twin known to date. Located 250 light-years from Earth, the star HIP 102152 is more like the Sun than any other solar twin — except that it is nearly four billion years older. This older, but almost identical, twin gives us an unprecedented chance to see how the Sun will look when it ages. The new observations also provide an important first clear link between a star’s age and its lithium content, and in addition suggest that HIP 102152 may be host to rocky terrestrial planets.

This image tracks the life of a Sun-like star, from its birth on the left side of the frame to its evolution into a red giant star on the right. On the left the star is seen as a protostar, embedded within a dusty disc of material as it forms. It later becomes a star like our Sun. After spending the majority of its life in this stage, the star's core begins to gradually heat up, the star expands and becomes redder until it transforms into a red giant.

Credit: ESO/M. Kornmesser

The above  image is illustrative; the ages, sizes, and colours are approximate (not to scale). The protostar stage, on the far left of this image, can be some 2000 times larger than our Sun. The red giant stage, on the far right of this image, can be some 100 times larger than the Sun.

Astronomers have only been observing the Sun with telescopes for 400 years — a tiny fraction of the Sun’s age of 4.6 billion years. It is very hard to study the history and future evolution of our star, but we can do this by hunting for rare stars that are almost exactly like our own, but at different stages of their lives. Now astronomers have identified a star that is essentially an identical twin to our Sun, but 4 billion years older — almost like seeing a real version of the twin paradox in action [1].

Jorge Melendez (Universidade de São Paulo, Brazil), the leader of the team and co-author of the new paper explains: “For decades, astronomers have been searching for solar twins in order to know our own life-giving Sun better. But very few have been found since the first one was discovered in 1997. We have now obtained superb-quality spectra from the VLT and can scrutinise solar twins with extreme precision, to answer the question of whether the Sun is special.”

This image shows solar twin HIP 102152, a star located 250 light-years from Earth in the constellation of Capricornus (The Sea Goat). HIP 102152 is more like the Sun than any other solar twin — apart from the fact that it is nearly four billion years older, giving us an unprecedented chance to study how the Sun will look when it ages. It is the oldest solar twin identified to date, and was studied by an international team using ESO’s Very Large Telescope, led by astronomers in Brazil.  The different colours of the star are caused by the star moving slightly between the two exposures, many years apart.
Image of HIP 102152
Credit: ESO/Digitized Sky Survey 2. Acknowledgement: Davide De Martin

The team studied two solar twins [2] — one that was thought to be younger than the Sun (18 Scorpii) and one that was expected to be older (HIP 102152). They used the UVES spectrograph on the Very Large Telescope (VLT) at ESO's Paranal Observatory to split up the light into its component colours so that the chemical composition and other properties of these stars could be studied in great detail.

They found that HIP 102152 in the constellation of Capricornus (The Sea Goat) is the oldest solar twin known to date. It is estimated to be 8.2 billion years old, compared to 4.6 billion years for our own Sun. On the other hand 18 Scorpii was confirmed to be younger than the Sun — about 2.9 billion years old.

Studying the ancient solar twin HIP 102152 allows scientists to predict what may happen to our own Sun when it reaches that age, and they have already made one significant discovery. “One issue we wanted to address is whether or not the Sun is typical in composition,” says Melendez. “Most importantly, why does it have such a strangely low lithium content?”

Lithium, the third element in the periodic table, was created in the Big Bang along with hydrogen and helium. Astronomers have pondered for years over why some stars appear to have less lithium than others. With the new observations of HIP 102152, astronomers have taken a big step towards solving this mystery by pinning down a strong correlation between a Sun-like star’s age and its lithium content.

Our own Sun now has just 1% of the lithium content that was present in the material from which it formed. Examinations of younger solar twins have hinted that these younger siblings contain significantly larger amounts of lithium, but up to now scientists could not prove a clear correlation between age and lithium content [3].

TalaWanda Monroe (Universidade de São Paulo), the lead author on the new paper, concludes: “We have found that HIP 102152 has very low levels of lithium. This demonstrates clearly for the first time that older solar twins do indeed have less lithium than our own Sun or younger solar twins. We can now be certain that stars somehow destroy their lithium as they age, and that the Sun's lithium content appears to be normal for its age.” [4]

A final twist in the story is that HIP 102152 has an unusual chemical composition pattern that is subtly different to most other solar twins, but similar to the Sun. They both show a deficiency of the elements that are abundant in meteorites and on Earth. This is a strong hint that HIP 102152 may host terrestrial rocky planets [5].
Notes

[1] Many people have heard of the twin paradox: one identical twin takes a space journey and comes back to Earth younger than their sibling. Although there is no time travelling involved here, we see two distinctly different ages for these two very similar stars — snapshots of the Sun’s life at different stages.

[2] Solar twins, solar analogues and solar-type stars are categories of stars according to their similarity to our own Sun. Solar twins are the most similar to our Sun, as they have very similar masses, temperatures, and chemical abundances. Solar twins are rare but the other classes, where the similarity is less precise, are much more common.

[3] Previous studies have indicated that a star’s lithium content could also be affected if it hosts giant planets (eso0942, eso0118,Nature paper), although these results have been debated (ann1046).

[4] It is still unclear exactly how lithium is destroyed within the stars, although several processes have been proposed to transport lithium from the surface of a star into its deeper layers, where it is then destroyed.

[5] If a star contains less of the elements that we commonly find in rocky bodies, this indicates that it is likely to host rocky terrestrial planets because such planets lock up these elements as they form from a large disc surrounding the star. The suggestion that HIP 102152 may host such planets is further reinforced by the radial velocity monitoring of this star with ESO's HARPS spectrograph, which indicates that inside the star’s habitable zone there are no giant planets. This would allow the existence of potential Earth-like planets around HIP 102152; in systems with giant planets existing close in to their star, the chances of finding terrestrial planets are much less as these small rocky bodies are disturbed and disrupted.
More information

This research was presented in a paper to appear in “High precision abundances of the old solar twin HIP 102152: insights on Li depletion from the oldest Sun”, by TalaWanda Monroe et al. in the Astrophysical Journal Letters.

The team is composed of TalaWanda R. Monroe, Jorge Meléndez (Universidade de São Paulo, Brazil [USP]), Iván Ramírez (The University of Texas at Austin, USA), David Yong (Australian National University, Australia [ANU]), Maria Bergemann (Max Planck Institute for Astrophysics, Germany), Martin Asplund (ANU), Jacob Bean, Megan Bedell (University of Chicago, USA), Marcelo Tucci Maia (USP), Karin Lind (University of Cambridge, UK), Alan Alves-Brito, Luca Casagrande (ANU), Matthieu Castro, José-Dias do Nascimento (Universidade Federal do Rio Grande do Norte, Brazil), Michael Bazot (Centro de Astrofísica da Universidade de Porto, Portugal) and Fabrício C. Freitas (USP).

ESO is the foremost intergovernmental astronomy organisation in Europe and the world’s most productive ground-based astronomical observatory by far. It is supported by 15 countries: Austria, Belgium, Brazil, the Czech Republic, Denmark, France, Finland, Germany, Italy, the Netherlands, Portugal, Spain, Sweden, Switzerland and the United Kingdom. ESO carries out an ambitious programme focused on the design, construction and operation of powerful ground-based observing facilities enabling astronomers to make important scientific discoveries. ESO also plays a leading role in promoting and organising cooperation in astronomical research. ESO operates three unique world-class observing sites in Chile: La Silla, Paranal and Chajnantor. At Paranal, ESO operates the Very Large Telescope, the world’s most advanced visible-light astronomical observatory and two survey telescopes. VISTA works in the infrared and is the world’s largest survey telescope and the VLT Survey Telescope is the largest telescope designed to exclusively survey the skies in visible light. ESO is the European partner of a revolutionary astronomical telescope ALMA, the largest astronomical project in existence. ESO is currently planning the 39-metre European Extremely Large optical/near-infrared Telescope, the E-ELT, which will become “the world’s biggest eye on the sky”.

Ultracold Big Bang Experiment Successfully Simulates Evolution Of Early Universe

Physicists have reproduced a pattern resembling the cosmic microwave background radiation in a laboratory simulation of the Big Bang, using ultracold cesium atoms in a vacuum chamber at the University of Chicago.

“This is the first time an experiment like this has simulated the evolution of structure in the early universe,” said Cheng Chin, professor in physics. Chin and his associates reported their feat in the Aug. 1 edition of Science Express, and it will appear soon in the print edition of Science.

Prof. Cheng Chin and his UChicago associates have simulated the impossibly hot conditions that followed the big bang within an ultracold vacuum chamber in his sub-basement laboratory in the Gordon Center for Integrative Science.
Cheng Chin
Photo by Jason Smith 

Chin pursued the project with lead author Chen-Lung Hung, PhD’11, now at the California Institute of Technology, and Victor Gurarie of the University of Colorado, Boulder. Their goal was to harness ultracold atoms for simulations of the Big Bang to better understand how structure evolved in the infant universe.

The cosmic microwave background is the echo of the Big Bang. Extensive measurements of the CMB have come from the orbiting Cosmic Background Explorer in the 1990s, and later by the Wilkinson Microwave Anisotropy Probe and various ground-based observatories, including the UChicago-led South Pole Telescope collaboration. These tools have provided cosmologists with a snapshot of how the universe appeared approximately 380,000 years following the Big Bang, which marked the beginning of our universe.

It turns out that under certain conditions, a cloud of atoms chilled to a billionth of a degree above absolute zero (-459.67 degrees Fahrenheit) in a vacuum chamber displays phenomena similar to those that unfolded following the Big Bang, Hung said.

“At this ultracold temperature, atoms get excited collectively. They act as if they are sound waves in air,” he said. The dense package of matter and radiation that existed in the very early universe generated similar sound-wave excitations, as revealed by COBE, WMAP and the other experiments.

The synchronized generation of sound waves correlates with cosmologists’ speculations about inflation in the early universe. “Inflation set out the initial conditions for the early universe to create similar sound waves in the cosmic fluid formed by matter and radiation,” Hung said.

BIG BANG’S RIPPLING ECHO

The sudden expansion of the universe during its inflationary period created ripples in space-time in the echo of the Big Bang. One can think of the Big Bang, in oversimplified terms, as an explosion that generated sound, Chin said. The sound waves began interfering with each other, creating complicated patterns. “That’s the origin of complexity we see in the universe,” he said.

These excitations are called Sakharov acoustic oscillations, named for Russian physicist Andrei Sakharov, who described the phenomenon in the 1960s. To produce Sakharov oscillations, Chin’s team chilled a flat, smooth cloud of 10,000 or so cesium atoms to a billionth of a degree above absolute zero, creating an exotic state of matter known as a two-dimensional atomic superfluid.

Then they initiated a quenching process that controlled the strength of the interaction between the atoms of the cloud. They found that by suddenly making the interactions weaker or stronger, they could generate Sakharov oscillations.

The universe simulated in Chin’s laboratory measured no more than 70 microns in diameter, approximately the diameter as a human hair. “It turns out the same kind of physics can happen on vastly different length scales,” Chin explained. “That’s the power of physics.”

The goal is to better understand the cosmic evolution of a baby universe, the one that existed shortly after the Big Bang. It was much smaller then than it is today, having reached a diameter of only a hundred thousand light years by the time it had left the CMB pattern that cosmologists observe on the sky today.

In the end, what matters is not the absolute size of the simulated or the real universes, but their size ratios to the characteristic length scales governing the physics of Sakharov oscillations. “Here, of course, we are pushing this analogy to the extreme,” Chin said.

380,000 YEARS VERSUS 10 MILLISECONDS

“It took the whole universe about 380,000 years to evolve into the CMB spectrum we’re looking at now,” Chin said. But the physicists were able to reproduce much the same pattern in approximately 10 milliseconds in their experiment. “That suggests why the simulation based on cold atoms can be a powerful tool,” Chin said.

None of the Science co-authors are cosmologists, but they consulted several in the process of developing their experiment and interpreting its results. The co-authors especially drew upon the expertise of UChicago’s Wayne Hu, John Carlstrom and Michael Turner, and of Stanford University’s Chao-Lin Kuo.

Hung noted that Sakharov oscillations serve as an excellent tool for probing the properties of cosmic fluid in the early universe. “We are looking at a two-dimensional superfluid, which itself is a very interesting object. We actually plan to use these Sakharov oscillations to study the property of this two-dimensional superfluid at different initial conditions to get more information.”

The research team varied the conditions that prevailed early in the history of the expansion of their simulated universes by quickly changing how strongly their ultracold atoms interacted, generating ripples. “These ripples then propagate and create many fluctuations,” Hung said. He and his co-authors then examined the ringing of those fluctuations.

Today’s CMB maps show a snapshot of how the universe appeared at a moment in time long ago. “From CMB, we don’t really see what happened before that moment, nor do we see what happened after that,” Chin said. But, Hung noted, “In our simulation we can actually monitor the entire evolution of the Sakharov oscillations.”

Chin and Hung are interested in continuing this experimental direction with ultracold atoms, branching into a variety of other types of physics, including the simulation of galaxy formation or even the dynamics of black holes.

“We can potentially use atoms to simulate and better understand many interesting phenomena in nature,” Chin said. “Atoms to us can be anything you want them to be.”


Contacts and sources: 
Steve Koppes
University of Chicago

Citation: “From Cosmology to Cold Atoms: Observation of Sakharov Oscillations in a Quenched Atomic Superfluid,” by Chen-Lung Hung, Victor Gurarie and Cheng Chin. Originally published in Science Express, Aug. 1, 2013

Funding: National Science Foundation, Army Research Office and the Packard Foundation

Neutron Stars In The Computer Cloud

The combined computing power of 200,000 private PCs helps astronomers take an inventory of the Milky Way. The Einstein@Home project connects home and office PCs of volunteers from around the world to a global supercomputer. Using this computer cloud, an international team lead by scientists from the Max Planck Institutes for Gravitational Physics and for Radio Astronomy analysed archival data from the CSIRO Parkes radio telescope in Australia. Using new search methods, the global computer network discovered 24 pulsars – extraordinary stellar remnants with extreme physical properties. These can be used as testbeds for Einstein's general theory of relativity and could help to complete our picture of the pulsar population.

 Einstein@Home searches for unknown neutron stars through their pulsed radio emission. This image shows an artist's impression of a neutron star, surrounded by its strong magnetic field (blue). It emits a narrow beam of radio waves (magenta) above its magnetic poles. When the star's rotation sweeps these beams over the Earth, the neutron star can be detected as a radio pulsar
standard
Credit: © NASA

“We could only conduct our search thanks to the enormous computing power provided by the Einstein@Home volunteers,” says Benjamin Knispel, researcher at the Max Planck Institute for Gravitational Physics (Albert Einstein Institute/AEI) in Hannover, and lead author of the study now published in The Astrophysical Journal. “Through the participation of the public, we discovered 24 new pulsars in our Milky Way, which had previously been missed – and some of them are particularly interesting.”
Complex searches for cosmic lighthouses

Pulsars are the remnants from explosions of massive stars. They are strongly magnetized and extremely dense neutron stars. They rapidly rotate and emit a beam of radio waves along their magnetic field axis – similar to the spotlight of a lighthouse. If the radio wave beam points towards Earth, the pulsar can be observed.

Large and sensitive radio telescopes are required to discover the weak signals from new pulsars. Knispel and his colleagues analysed data from the Parkes Multi-beam Pulsar Survey, conducted from 1997 to 2001, with the 64-meter antenna of CSIRO's Parkes radio telescope in southeast Australia. “The search for new radio pulsars is very computer intensive. To determine the a priori unknown characteristics of the pulsar, e.g., its distance or its rotation period, we have to very finely comb through wide parameter ranges,” says Knispel.
Pulsar searches with public participation

Each week, 50,000 volunteers from around the world “donate” idle compute cycles on their 200,000 home and office PCs to Einstein@Home. Together they combine to yield a sustained computing power of around 860 teraFLOPs per second. This places Einstein@Home on par with the world's fastest supercomputers. The analysis of the archival Parkes data was completed in eight months, while the same task would have taken a single CPU core more than 17,000 years.

Raw computing power was not the only important factor to discover the two dozen new pulsars. The development of new post-processing methods proved to be just as crucial. The recorded data often contain pulsar-like, man-made interference signals. The astronomers employed new methods that allowed them to discover pulsars previously masked by the presence of these interference signals.
Unusual species in the pulsar zoo

The researchers used the radio telescopes near Parkes, at the Jodrell Bank Observatory, and at Effelsberg for follow-up observations and to characterize their discoveries in more detail. “There are different kinds of pulsars, just like there are different animal species in a zoo. Some are more common than others – in some cases, only a handful of specimens are known,” explains Ralph Eatough, scientist at the Max Planck Institute for Radio Astronomy (MPIfR) in Bonn and second author of the publication.

Pulsars in binary systems are of particular interest to the astronomers. That is because these objects allow insights into their formation history and because they can be used as testbeds for Einstein's general theory of relativity. However, discovering them is even more computationally demanding than the already challenging task of finding isolated pulsars. Tracking down their complex signals in the data increases the computing costs that far exceeds the computing capacities at the two Max Planck Institutes.

Out of the 24 pulsars discovered by Einstein@Home, six are in binary systems orbiting the common centre of mass with their stellar partner. These systems form only under very specific astrophysical conditions, which the scientists can now reconstruct more precisely. One of the newly discovered pulsars has an unusually long orbital period of about 940 days – the fourth longest known. In the future, it could be used as a testbed for Einstein's general theory of relativity.
From Parkes data to the Milky Way's pulsar population

The three radio telescopes that were used to to discover, to confirm orinvestigate the 24 pulsars: The Parkes radio telescope of the Australian research organization CSIRO (above), the Lovell telescope at the English Jodrell Bank Observatory (bottom left) and the 100-m radio telescope in Effelsberg, part of the Max Planck Institute for Radio Astronomy
© CSIRO/Jodrell Bank/Anthony Holloway/MPIfR/Norbert Tacken

Some of the pulsars that were discovered appear to switch off their radio emission for some minutes or hours. “This phenomenon has been observed before, but it is not yet fully understood. Further investigations could help to improve our understanding of the processes in the pulsars' strong magnetic fields, which power their radio emission,” says Eatough.

It is not only important to find these exceptional objects, but also to discover “normal” pulsars. The Parkes Multi-beam Pulsar Survey is often used as reference for numerical simulations of our Galaxy's pulsar population. Only by finding all pulsars hidden in the data, can astronomers draw precise conclusions about the entirety of pulsars in the Milky Way.
A computing model for the future

“Our discoveries prove that distributed computing projects like Einstein@Home can play an important role in modern, data-based astronomy,” says Bruce Allen, director of Einstein@Home and director at the AEI. “We expect distributed computing to become increasingly important for astronomical data analysis in the future. Einstein@Home is also very well prepared for the increasing mobility of computing power,” says Allen. Recently, volunteers can not only sign up their PCs for the project, but also help to find new radio pulsars with their Android-based smartphones and tablets.

“In one of our next projects, we would like to use Einstein@Home's computing power to search for pulsars in compact binary systems using 'fresh' data from our very sensitive radio telescope near Effelsberg,” says Michael Kramer, director at the MPIfR. Such systems enable tests of the general theory of relativity: its effects are strongest when massive bodies orbit each other at a small distance. Michael Kramer is looking forward to the search: “Who knows what surprises are waiting for us.”


Background information on Einstein@Home

This distributed volunteer computing project connects PC users from all over the world, who voluntarily donate spare computing time on their home and office computers. It has more than 340,000 participants and is one of the largest projects of this kind. Scientific supporters are the Center for Gravitation and Cosmology at the University of Wisconsin-Milwaukee and the Max Planck Institute for Gravitational Physics (Albert Einstein Institute, Hanover) with financial support from the National Science Foundation and the Max Planck Society.

Since 2005, Einstein@Home has analysed data from the gravitational wave detectors within the LIGO-Virgo-Science Collaboration (LVC) for gravitational waves from unknown, rapidly rotating neutron stars.

Since March 2009, Einstein@Home has also been involved in the search for signals from radio pulsars in observational data from the Arecibo Observatory in Puerto Rico and CSIRO's Parkes radio telescope in Australia. Since the first discovery of a radio pulsar by Einstein@Home in August 2010, the global computer network has discovered almost 50 new radio pulsars.

A new search for gamma-ray pulsars in data of the Fermi satellite was added in August 2011; the project is looking for, among other things, the first millisecond pulsar, visible only in the gamma-ray range.

Contacts and sources: 
Dr. Benjamin Knispel
Max-Planck-Gesellschaft

Tuesday, August 27, 2013

Submarine Canyons A Source Of Marine Invertebrate Diversity, Abundance

Submarine canyons play an important role in maintaining high levels of biodiversity of small invertebrates in the seafloor sediments of the main and northwestern Hawaiian Islands, according to research from the University of Hawai‘i at Mānoa.

What’s more, scientists have used this data to draw new connections between the levels of faunal diversity and the heterogeneity of submarine canyon landscapes at various spatial scales.

Researchers sampled diversity in Hawaii's submarine canyons, including these off Kaneohe Bay
Researchers sampled diversity in Hawaii's submarine canyons, including these off Kaneohe Bay.
Credit:  University of Hawai‘i at Mānoa.

“Submarine canyons encompass myriad habitat types,” said Fabio C. De Leo, a doctoral graduate from UH Mānoa’s department of oceanography and the lead author on a new paper that was recently published in the scientific journal Deep Sea Research Part II. “This heterogeneity at the landscape-scale helps to enhance local biodiversity in canyon seafloor sediments.”

De Leo and colleagues, including oceanography professor Craig Smith, the study’s principal investigator (PI), conducted 34 submersible dives into six underwater canyons and their nearby slopes. Plumbing depths of up to 1,500 meters (~5,000 feet), their study area ranged across the Hawaiian archipelago, from the main Hawaiian Islands through Papahānaumokuākea Marine National Monument in the Northwestern Hawaiian Islands.

The scientists evaluated and mapped landscape metrics of each canyon habitat, including the roughness of the seafloor and the steepness of canyon walls. At depths of 350, 650, and 1,000 meters in each location, they collected sediment core samples on the canyon floor. From these samples, they carefully sorted out and identified all of the marine organisms called macrobenthos—including worms, clams and shrimp-like crutaceans— that range in size from a millimeter to several centimeters. The scientists then correlated the macrobenthos species data with the landscape metrics.

View of the sediment coring process, from inside the submersible.
View of the sediment coring process, from inside the submersible.
Credit:  University of Hawai‘i at Mānoa.

The scientists found that submarine canyons can serve as species oases in the sea by channeling ocean currents, capturing and trapping sinking particles, funneling migrating animals, and generally providing a varied physical landscape. As a result, canyons promote high species diversity.

Researchers say this is the first study of its kind to thoroughly examine submarine canyons on island margins. The research effort had previously yielded reports of high species diversity of fish and large invertebrates, the so-called megafauna, in Hawai‘i’s submarine canyons. This corroboration led them to conclude: “Canyons may be particularly important in the Hawaiian islands, in part because they supply organic matter to the typically food-limited deep sea,” De Leo said. “When there’s more food, there’s more life.”

One thing that became evident from this study was that canyons near the main Hawaiian islands tended to collect and hold much more land-based organic matter than canyons in the Northwestern Hawaiian Islands. Materials such as branches, leaves, nuts and algae were abundant off Moloka‘i and O‘ahu, washed into the ocean by rain and carried out deep onto the canyon floors by ocean currents. These decomposing materials, scarcer in the islands of Nihoa and Maro Reef, serve as valuable food sources for the seafloor invertebrates, themselves a food source for other, larger fish.

The scientists have already documented four new species discovered during the course of their research dives, including three new types of crustaceans. Up to 60 percent of the species that taxonomists identified in the submarine canyon seafloor samples are only recognized to the family level.

“There is room for discovery of many more new species,” De Leo said. “The deep sea fauna of Hawai‘i is poorly sampled and poorly understood. Every time we go to sea and sample a new area, it’s likely that we’ll find a new species.”

This series of dives was conducted on the Pisces IV and Pisces V manned submersibles operated by the Hawai‘i Undersea Research Laboratory (HURL). The research was conducted in partnership with Hawai‘i Pacific University and the New Zealand National Institute of Water and Atmospheric Research.

Citation: Fabio C. De Leo, E.W. Vetter, C. R. Smith, A. R. Ashley, and M. McGranaghan. Spatial scale-dependent habitat heterogeneity influences submarine canyon macrofaunal abundance and diversity off the Main and Northwest Hawaiian Islands. Deep Sea Research Part II: Topical Studies in Oceanography. 11 July 2013.


Contacts and sources:
Talia S. Ogliore
University of Hawaii at Manoa

Tricking The Tuberculosis Bacterium Could Save Many People

There are 633,000 homeless people in America, many of whom have a high risk of contracting tuberculosis, a lethal disease that attacks the lungs. In Los Angeles' Skid Row neighborhood alone, more than 4,500 people have been exposed to tuberculosis, or TB. Now, scientists at the UCLA School of Medicine have uncovered a medical mystery that may help the homeless in the United States and millions across the globe.

File:Tuberculosis symptoms.svg

“[Tuberculosis] is a very contagious disease. It’s something you can catch in the elevator. If someone coughs, they can spread the bacteria to you,” said Dr. Robert Modin, a microbiologist at UCLA.

TB is difficult to fight mainly because it has learned to hide out in the body disguised as a virus. “These bacteria are wolf in sheep’s clothing and the immune system is tricked in how it detects it,” explained Dr. Modin.

Normally, the immune system releases a protein called interferon gamma when it detects bacteria in its system. The interferon gamma helps to destroy the invading bacteria. But UCLA's researchers found that when bacteria act like viruses, the immune system is fooled into launching an attack using a different protein called interferon beta, which is designed to kill viruses, not bacteria. Undeterred by the interferon beta, TB bacteria can grow and multiply without being attacked by the immune system.

Modin said, “The immune response thinks it’s dealing with a virus instead of the bacteria and in doing that it shuts off the hosts mechanisms to kill the bacteria.”

TB kills 1.4 million people worldwide each year and is very similar to the bacterium that causes leprosy, which continues to affect hundreds of thousands of people around the globe. Scientists are hopeful that this discovery will improve the treatment of both diseases.

Now that scientists know TB's secret and have been successful in stopping TB in the lab, they hope to stop it in people.


Contacts and sources:
Marsha Lewis
ISTV Contributing Producer

European Hunter-Gatherers Owned Pigs As Early As 4600 BC

European hunter-gatherers acquired domesticated pigs from nearby farmers as early as 4600 BC, according to new evidence.

The international team of scientists, including researchers at Durham and Aberdeen universities, showed there was interaction between the hunter-gatherer and farming communities and a 'sharing' of animals and knowledge. The interaction between the two groups eventually led to the hunter-gatherers incorporating farming and breeding of livestock into their culture, say the scientists.


Credit: Durham University

The research, published in Nature Communications today (27 August), gives new insights into the movements of pre-historic humans and the transition of technologies and knowledge.

The spread of plants and animals throughout Europe between 6000 and 4000BC involved a complex interplay between indigenous Mesolithic hunter-gatherers and incoming Neolithic farmers but the scale of the interaction and the extent to which hunter-gatherers took ideas from their neighbours remains hotly debated.

The researchers say previous evidence about the ownership of domestic animals by hunter-gatherers has so far been circumstantial.

Lead author, Dr Ben Krause-Kyora, from Christian-Albrechts University in Kiel, Germany, said: "Mesolithic hunter-gatherers definitely had dogs, but they did not practise agriculture and did not have pigs, sheep, goats, or cows, all of which were introduced to Europe with incoming farmers about 6000BC. Having people who practised a very different survival strategy nearby must have been odd, and we know now that the hunter-gathers possessed some of the farmers' domesticated pigs."

It is not yet known whether the hunter-gatherers received the pigs via trade or exchange, or by hunting and capturing escaped animals. However, the domestic pigs had different coloured and spotted coats that would have seemed strange and exotic to the hunter-gatherers and may have attracted them to the pigs.

Co-author, Dr Greger Larson, from the Department of Archaeology at Durham University, added: "Humans love novelty, and though hunter-gatherers exploited wild boar, it would have been hard not to be fascinated by the strange-looking spotted pigs owned by farmers living nearby. It should come as no surprise that the hunter-gatherers acquired some eventually, but this study shows that they did very soon after the domestic pigs arrived in northern Europe."

The team analysed the ancient DNA from the bones and teeth of 63 pigs from Northern Germany which showed that the hunter-gatherers acquired domestic pigs of varying size and coat colour that had both Near Eastern and European ancestry.

The research was led by Christian-Albrechts University, Germany and involved researchers from Durham University, UK; University of Aberdeen, UK; Natural History Museum, UK; Archäologisches Landesmuseum Schloss Gottorf, Germany; University Hospital Schleswig-Holstein, Germany; Graduate School Human Development in Landscapes, Germany.

The project received funding from the Natural Environment Research Council (NERC) and the Graduate School 'Human Development in Landscapes'.


Contacts and sources:
Dionne Hamil
Durham University

The Octopus Whisperer

Writer and explorer Sy Montgomery is delving into the mind of the world’s most intelligent invertebrate, and bringing back stories to tell to both children and adults.

“You are what you eat” is a truism for foodies, and also for writers—at least those who occasionally use a character’s diet as an avenue into that character’s soul. It works because often there are obvious links between who a person is and the sort of menu choices he or she makes. But can you say the same for, well—an octopus?

Sy Montgomery—author, naturalist, adventurer, and affiliate member of the faculty at Southern New Hampshire University’s low-residency MFA in Fiction and Nonfiction program—has just returned from a sojourn with an international team of scientists wondering just that. The true story of their quest to answer that question will fill the pages of Montgomery’s work-in-progress, a children’s book called “The Octopus Scientists: Inside the Mind of a Mollusc.”

Sy Montgomery interviews a Pacific day octopus named Cyanea
Credit: Southern New Hampshire University

Montgomery couldn’t help laughing as she described one of the research activities conducted by the scientists in the waters off Moorea, a tiny island in French Polynesia. “You put on your wetsuit, go down with an underwater dive slate, and set about administering a personality test to octopus,” she said. “So you float there and take notes like a psychologist on whether this particular octopus to advances or retreats, changes color or reaches out, and so on.”

One of the chief goals of the expedition was to gather information on not just what is eaten by the Pacific day octopus—a species that grows to around three feet across—but why. In other words, what differences exist between individual octopuses and their diets, and what might account for those differences?

The expedition’s lead scientist—Dr. Jennifer Mather of Canada’s University of Lethbridge—proposed that any differences might have much to do with personality, just as they do in people, and hence those slate-board sessions with creatures that are shy and reclusive, but also highly intelligent and intensely curious—and therefore sometimes willing to come out and take personality tests.

“The Octopus Scientists” will appear from Houghton Mifflin in 2015 as the next in a popular children’s series originated by Montgomery, “Scientists in the Field.” Each book is a sort of expedition into the soul of its animal subject—the snow leopard, for example, or the tree kangaroo, or the goliath bird-eating tarantula—but the books are as much about the scientists who study these animals: who they are and how they go about their work.

The most recent in the series, “The Tapir Scientist: Saving South America’s Largest Mammal,” appeared just last month to admiring reviews. In this book Montgomery takes her young readers to Brazil’s Pantanal, a huge expanse of marshland and subtropical forest (“The Everglades on steroids,” said Montgomery), to track one of the world’s most elusive megafauna.

The book “seamlessly blends eloquent text and vivid images to spotlight the gentle tapir and those field scientists whose lives are committed to conserve animal species for the sake of our environment and our humanity,” said Booklist. Kirkus Reviews, in a starred review, praised the book’s “lively, first-person voice” and “memorable detail.”

Montgomery has a big following among adults as well. Her memoir about the runt pig that she adopted and raised, “The Good, Good Pig” (Ballantine, 2007), hit the New York Times bestseller list. She is also the author more recently of “Birdology” (Simon & Schuster 2011) and “Journey of the Pink Dolphin” (Chelsea Green 2009).

Another work-in-progress is a much longer book about octopuses for adults, a book that begins with a giant Pacific octopus Montgomery met at the New England Aquarium in 2011. Her readers will make the acquaintance of octopuses in aquaria on both coasts, sit in on interviews with octopus experts from around the world, and go scuba diving for a week off Mexico. “The Soul of the Octopus” will be published simultaneously with its children’s companion by Simon & Schuster in 2015.

In the waters off Moorea, the octopus scientists, as well as Montgomery, collected shells and crab carapaces from outside lairs and went swimming with octopuses on the hunt. Dr. Mather’s hypothesis—“That bolder octopuses would be more varied in their diet,” said Montgomery, “like someone who samples every restaurant in a city”—was just one of the theories tested about octopus behavior, habitat, and personality.

But the mere fact of personality in these invertebrates came as no surprise to Montgomery. “At the Seattle Aquarium there was a very shy octopus who hardly ever came out of her lair named Emily Dickinson,” she said. “Then there’s the one who likes to put his suckers all over you. He was called Leisure Suit Larry.”

In Moorea, for the first time, Montgomery was able to interact with wild octopuses. There she fell even more deeply in love with this other sort of intelligence: creatures who use skin color both to disappear into the background and to express emotion; who have been seen lifting scallop shells in front of their lairs in defense against marauding sharks; who seem to occasionally keep crabs or catfish as pets.

“We really know so little about these guys, but they’re just amazing,” Montgomery said. “You can watch an octopus extend one arm into a hole on a coral reef, looking something to eat, and in its eyes you can see the same expression that a person assumes fishing for a set of keys in her pocket. It’s just so cool.”

Diane Les Becquets, novelist and director of the MFA writing program at Southern New Hampshire University, is proud to include Montgomery among the menu of her faculty members. “We have a strong environmental nonfiction track in our program,” she said, “and having as an affiliate a writer of Sy’s skill, stature, and passion lends that track a unique sort of breadth. She’s also just simply an inspiration to us all.


Contacts and sources:
Richard Adams Carey
Assistant Director, MFA in Fiction and Nonfiction
Southern New Hampshire University

Supervolcanic Ash Can Turn To Lava Miles From Eruption, MU Scientists Find

Supervolcanoes, such as the one sitting dormant under Yellowstone National Park, are capable of producing eruptions thousands of times more powerful than normal volcanic eruptions. While they only happen every several thousand years, these eruptions have the potential to kill millions of people and animals due to the massive amount of heat and ash they release into the atmosphere. Now, researchers at the University of Missouri have shown that the ash produced by supervolcanoes can be so hot that it has the ability to turn back into lava once it hits the ground tens of miles away from the original eruption.

Evidence of flowing lava hardened into rock found in Idaho several miles away from the site of an 8 million year old supervolcano eruption at Yellowstone. 
Photo Credit: Graham Andrews, assistant professor at California State University Bakersfield.

Following a volcanic eruption, lava typically flows directly from the site of the eruption until it cools enough that it hardens in place. However, researchers found evidence of an ancient lava flow tens of miles away from a supervolcano eruption near Yellowstone that occurred around 8 million years ago. Previously, Graham Andrews, an assistant professor at California State University Bakersfield, found that this lava flow was made of ash ejected during the eruption. Following Andrew’s discovery, Alan Whittington, an associate professor in the University of Missouri department of geological sciences in the College of Arts and Science, along with lead author Genevieve Robert and Jiyang Ye, both doctoral students in the geological sciences department, determined how this was possible.

Evidence of flowing lava hardened into rock found in Idaho several miles away from the site of an 8 million year old supervolcano eruption at Yellowstone.
Photo Credit: Graham Andrews, assistant professor at California State University Bakersfield.

“During a supervolcano eruption, pyroclastic flows, which are giant clouds of very hot ash and rock, travel away from the volcano at typically a hundred miles an hour,” Robert said. “We determined the ash must have been exceptionally hot so that it could actually turn into lava and flow before it eventually cooled.”

Because the ash should have cooled too much in the air to turn into lava right as it landed, the researchers believe the phenomenon was made possible by a process known as “viscous heating.” Viscosity is the degree to which a liquid resists flow. The higher the viscosity, the less the substance can flow. For example, water has a very low viscosity, so it flows very easily, while molasses has a higher viscosity and flows much slower. Whittington likens the process of viscous heating to stirring a pot of molasses.

Evidence of flowing lava hardened into rock found in Idaho several miles away from the site of an 8 million year old supervolcano eruption at Yellowstone.
Photo Credit: Graham Andrews, assistant professor at California State University Bakersfield.

“It is very hard to stir a pot of molasses and you have to use a lot of energy and strength to move your spoon around the pot,” Whittington said. “However, once you get the pot stirring, the energy you are using to move the spoon is transferred into the molasses, which actually heats up a little bit. This is viscous heating. So when you think about how fast the hot ash is traveling after a massive supervolcano eruption, once it hits the ground that energy is turned into heat, much like the energy from the spoon heating up the molasses. This extra heat created by viscous heating is enough to cause the ash to weld together and actually begin flowing as lava.”

Evidence of flowing lava hardened into rock found in Idaho several miles away from the site of an 8 million year old supervolcano eruption at Yellowstone
Photo Credit: Graham Andrews, assistant professor at California State University Bakersfield.

The volcanic ash from this eruption has to be at least 1,500 degrees Fahrenheit to turn into lava; however, since the ash should have lost some of that heat in the air, the researchers believe viscous heating accounted for 200 to 400 degrees Fahrenheit of additional heating to turn the ash into lava.

Robert, Andrews, Ye, and Whittington’s paper was published in Geology. The National Science Foundation funded this research through a CAREER award to Whittington.


Contacts and sources:
Nathan Hurst
University of Missouri-Columbia

Researcher Gains Control Of Another Man's Brain Over The Internet

Human To Human Brain Interface Allows Researcher To Control Another Person Hand Motions Over The Internet

University of Washington researchers have performed what they believe is the first noninvasive human-to-human brain interface, with one researcher able to send a brain signal via the Internet to control the hand motions of a fellow researcher.

University of Washington researcher Rajesh Rao, left, plays a computer game with his mind. Across campus, researcher Andrea Stocco, right, wears a magnetic stimulation coil over the left motor cortex region of his brain. Stocco’s right index finger moved involuntarily to hit the “fire” button as part of the first human brain-to-brain interface demonstration.

Credit: University of Washington

Using electrical brain recordings and a form of magnetic stimulation, Rajesh Rao sent a brain signal to Andrea Stocco on the other side of the UW campus, causing Stocco’s finger to move on a keyboard.

While researchers at Duke University have demonstrated brain-to-brain communication between two rats, and Harvard researchers have demonstrated it between a human and a rat, Rao and Stocco believe this is the first demonstration of human-to-human brain interfacing.

“The Internet was a way to connect computers, and now it can be a way to connect brains,” Stocco said. “We want to take the knowledge of a brain and transmit it directly from brain to brain.”

The researchers captured the full demonstration on video recorded in both labs. The following version has been edited for length.



Rao, a UW professor of computer science and engineering, has been working on brain-computer interfacing in his lab for more than 10 years and just published a textbook on the subject. In 2011, spurred by the rapid advances in technology, he believed he could demonstrate the concept of human brain-to-brain interfacing. So he partnered with Stocco, a UW research assistant professor in psychology at the UW’s Institute for Learning & Brain Sciences.

On Aug. 12, Rao sat in his lab wearing a cap with electrodes hooked up to anelectroencephalography machine, which reads electrical activity in the brain. Stocco was in his lab across campus wearing a purple swim cap marked with the stimulation site for the transcranial magnetic stimulation coil that was placed directly over his left motor cortex, which controls hand movement.

The team had a Skype connection set up so the two labs could coordinate, though neither Rao nor Stocco could see the Skype screens.

Rao looked at a computer screen and played a simple video game with his mind. When he was supposed to fire a cannon at a target, he imagined moving his right hand (being careful not to actually move his hand), causing a cursor to hit the “fire” button. Almost instantaneously, Stocco, who wore noise-canceling earbuds and wasn’t looking at a computer screen, involuntarily moved his right index finger to push the space bar on the keyboard in front of him, as if firing the cannon. Stocco compared the feeling of his hand moving involuntarily to that of a nervous tic.

“It was both exciting and eerie to watch an imagined action from my brain get translated into actual action by another brain,” Rao said. “This was basically a one-way flow of information from my brain to his. The next step is having a more equitable two-way conversation directly between the two brains.”

The cycle of the experiment. Brain signals from the “Sender” are recorded. When the computer detects imagined hand movements, a “fire” command is transmitted over the Internet to the TMS machine, which causes an upward movement of the right hand of the “Receiver.” This usually results in the “fire” key being hit.


University of Washington

The technologies used by the researchers for recording and stimulating the brain are both well-known. Electroencephalography, or EEG, is routinely used by clinicians and researchers to record brain activity noninvasively from the scalp. Transcranial magnetic stimulation is a noninvasive way of delivering stimulation to the brain to elicit a response. Its effect depends on where the coil is placed; in this case, it was placed directly over the brain region that controls a person’s right hand. By activating these neurons, the stimulation convinced the brain that it needed to move the right hand.

Computer science and engineering undergraduates Matthew Bryan, Bryan Djunaedi, Joseph Wu and Alex Dadgar, along with bioengineering graduate student Dev Sarma, wrote the computer code for the project, translating Rao’s brain signals into a command for Stocco’s brain.

“Brain-computer interface is something people have been talking about for a long, long time,” saidChantel Prat, assistant professor in psychology at the UW’s Institute for Learning & Brain Sciences, and Stocco’s wife and research partner who helped conduct the experiment. “We plugged a brain into the most complex computer anyone has ever studied, and that is another brain.”

At first blush, this breakthrough brings to mind all kinds of science fiction scenarios. Stocco jokingly referred to it as a “Vulcan mind meld.” But Rao cautioned this technology only reads certain kinds of simple brain signals, not a person’s thoughts. And it doesn’t give anyone the ability to control your actions against your will.

Both researchers were in the lab wearing highly specialized equipment and under ideal conditions. They also had to obtain and follow a stringent set of international human-subject testing rules to conduct the demonstration.

“I think some people will be unnerved by this because they will overestimate the technology,” Prat said. “There’s no possible way the technology that we have could be used on a person unknowingly or without their willing participation.”

Stocco said years from now the technology could be used, for example, by someone on the ground to help a flight attendant or passenger land an airplane if the pilot becomes incapacitated. Or a person with disabilities could communicate his or her wish, say, for food or water. The brain signals from one person to another would work even if they didn’t speak the same language.

Rao and Stocco next plan to conduct an experiment that would transmit more complex information from one brain to the other. If that works, they then will conduct the experiment on a larger pool of subjects.

Their research was funded in part by the National Science Foundation’s Engineering Research Center for Sensorimotor Neural Engineering at the UW, the U.S. Army Research Office and the National Institutes of Health.

Contacts and sources:
Doree Armstrong
University of Washington

Discovery Hints At Water Hidden In Moon's Interior

NASA-funded lunar research has yielded evidence of water locked in mineral grains on the surface of the moon from an unknown source deep beneath the surface.

Using data from NASA's Moon Mineralogy Mapper (M3) instrument aboard the Indian Space Research Organization's Chandrayaan-1 spacecraft, scientists remotely detected magmatic water, or water that originates from deep within the moon's interior, on the surface of the moon.

LROC Wide Angle Camera View of Bullialdus crater (60 km diameter). The approximate position of today's NAC featured image is highlighted with the white arrow.
Bullialdus Crater
 Credit: NASA/GSFC/Arizona State University

The findings, published Aug. 25 in Nature Geoscience, represent the first detection of this form of water from lunar orbit. Earlier studies had shown the existence of magmatic water in lunar samples returned during the Apollo program.

M3 imaged the lunar impact crater Bullialdus, which lies near the lunar equator. Scientists were interested in studying this area because they could better quantify the amount of water inside the rocks due to the crater's location and the type of rocks it held. The central peak of the crater is made up of a type of rock that forms deep within the lunar crust and mantle when magma is trapped underground.

"This rock, which normally resides deep beneath the surface, was excavated from the lunar depths by the impact that formed Bullialdus crater," said Rachel Klima, a planetary geologist at the Johns Hopkins University Applied Physics Laboratory (APL) in Laurel, Md.

"Compared to its surroundings, we found that the central portion of this crater contains a significant amount of hydroxyl - a molecule consisting of one oxygen atom and one hydrogen atom -- which is evidence that the rocks in this crater contain water that originated beneath the lunar surface," Klima said.

In 2009, M3 provided the first mineralogical map of the lunar surface and discovered water molecules in the polar regions of the moon. This water is thought to be a thin layer formed from solar wind hitting the moon's surface. Bullialdus crater is in a region with an unfavorable environment for solar wind to produce significant amounts of water on the surface.

"NASA missions like Lunar Prospector and the Lunar Crater Observation and Sensing Satellite and instruments like M3 have gathered crucial data that fundamentally changed our understanding of whether water exists on the surface of the moon," said S. Pete Worden, center director at NASA's Ames Research Center in Moffett Field, Calif. "Similarly, we hope that upcoming NASA missions such as the Lunar Atmosphere and Dust Environment Explorer, or LADEE, will change our understanding of the lunar sky."

The detection of internal water from orbit means scientists can begin to test some of the findings from sample studies in a broader context, including in regions that are far from where the Apollo sites are clustered on the near side of the moon. For many years, researchers believed that the rocks from the moon were bone-dry and any water detected in the Apollo samples had to be contamination from Earth.

"Now that we have detected water that is likely from the interior of the moon, we can start to compare this water with other characteristics of the lunar surface," said Klima. "This internal magmatic water also provides clues about the moon's volcanic processes and internal composition, which helps us address questions about how the moon formed, and how magmatic processes changed as it cooled."

APL is a not-for-profit division of Johns Hopkins University. Joshua Cahill and David Lawrence of APL and Justin Hagerty of the U.S. Geological Survey's Astrogeology Science Center in Flagstaff, Ariz., co-authored the paper. NASA's Lunar Advanced Science and Engineering Program, the NASA Lunar Science Institute (NLSI) at Ames and the NASA Planetary Mission Data Analysis Program supported the research. NLSI is a virtual organization jointly funded by NASA's Science Mission Directorate and NASA's Human Exploration and Operations Mission Directorate in Washington, to enable collaborative, interdisciplinary research in support of NASA lunar science programs.


Contacts and sources:
Rachel Hoover
Ames Research Center, Moffett Field

Chemical Weapons Use In Syria Were " Moral Obscenity" Says Secretary Of State John Kerry

Chemical Weapons Use In Syria Were " Moral Obscenity" Says Secretary Of State John Kerry 

Well, for the last several days President Obama and his entire national security team have been reviewing the situation in Syria, and today Secretary of State John Kerry said "I want to provide an update on our efforts as we consider our response to the use of chemical weapons."
 

In his briefing Kerry said, "What we saw in Syria last week should shock the conscience of the world. It defies any code of morality. Let me be clear: The indiscriminate slaughter of civilians, the killing of women and children and innocent bystanders, by chemical weapons is a moral obscenity. By any standard it is inexcusable, and despite the excuses and equivocations that some have manufactured, it is undeniable.

The meaning of this attack goes beyond the conflict in Syria itself, and that conflict has already brought so much terrible suffering. This is about the large-scale, indiscriminate use of weapons that the civilized world long ago decided must never be used at all – a conviction shared even by countries that agree on little else. There is a clear reason that the world has banned entirely the use of chemical weapons. There is a reason the international community has set a clear standard and why many countries have taken major steps to eradicate these weapons. There is a reason why President Obama has made it such a priority to stop the proliferation of these weapons and lock them down where they do exist. There is a reason why President Obama has made clear to the Assad regime that this international norm cannot be violated without consequences. And there is a reason why no matter what you believe about Syria, all peoples and all nations who believe in the cause of our common humanity must stand up to assure that there is accountability for the use of chemical weapons so that it never happens again.

Last night after speaking with foreign ministers from around the world about the gravity of this situation, I went back and I watched the videos, the videos that anybody can watch in the social media, and I watched them one more gut-wrenching time. It is really hard to express in words the human suffering that they lay out before us. As a father, I can’t get the image out of my head of a man who held up his dead child, wailing while chaos swirled around him; the images of entire families dead in their beds without a drop of blood or even a visible wound; bodies contorting in spasms; human suffering that we can never ignore or forget. Anyone who can claim that an attack of this staggering scale could be contrived or fabricated needs to check their conscience and their own moral compass.

What is before us today is real, and it is compelling. So I also want to underscore that while investigators are gathering additional evidence on the ground, our understanding of what has already happened in Syria is grounded in facts informed by conscience and guided by common sense. The reported number of victims, the reported symptoms of those who were killed or injured, the firsthand accounts from humanitarian organizations on the ground like Doctors Without Borders and the Syria Human Rights Commission – these all strongly indicate that everything these images are already screaming at us is real, that chemical weapons were used in Syria.

Moreover, we know that the Syrian regime maintains custody of these chemical weapons. We know that the Syrian regime has the capacity to do this with rockets. We know that the regime has been determined to clear the opposition from those very places where the attacks took place. And with our own eyes, we have all of us become witnesses.

We have additional information about this attack, and that information is being compiled and reviewed together with our partners, and we will provide that information in the days ahead.

Our sense of basic humanity is offended not only by this cowardly crime but also by the cynical attempt to cover it up. At every turn, the Syrian regime has failed to cooperate with the UN investigation, using it only to stall and to stymie the important effort to bring to light what happened in Damascus in the dead of night. And as Ban Ki-moon said last week, the UN investigation will not determine who used these chemical weapons, only whether such weapons were used – a judgment that is already clear to the world.

I spoke on Thursday with Syrian Foreign Minister Muallim and I made it very clear to him that if the regime, as he argued, had nothing to hide, then their response should be immediate – immediate transparency, immediate access – not shelling. Their response needed to be unrestricted and immediate access. Failure to permit that, I told him, would tell its own story.

Instead, for five days, the Syrian regime refused to allow the UN investigators access to the site of the attack that would allegedly exonerate them. Instead, it attacked the area further, shelling it and systematically destroying evidence. That is not the behavior of a government that has nothing to hide. That is not the action of a regime eager to prove to the world that it had not used chemical weapons. In fact, the regime’s belated decision to allow access is too late, and it’s too late to be credible. Today’s reports of an attack on the UN investigators, together with the continued shelling of these very neighborhoods, only further weakens the regime’s credibility.

At President Obama’s direction, I’ve spent many hours over the last few days on the phone with foreign ministers and other leaders. The Administration is actively consulting with members of Congress and we will continue to have these conversations in the days ahead. President Obama has also been in close touch with the leaders of our key allies, and the President will be making an informed decision about how to respond to this indiscriminate use of chemical weapons. But make no mistake: President Obama believes there must be accountability for those who would use the world’s most heinous weapons against the world’s most vulnerable people. Nothing today is more serious and nothing is receiving more serious scrutiny.Well, for the last several days President Obama and his entire national security team have been reviewing the situation in Syria, and today I want to provide an update on our efforts as we consider our response to the use of chemical weapons.

What we saw in Syria last week should shock the conscience of the world. It defies any code of morality. Let me be clear: The indiscriminate slaughter of civilians, the killing of women and children and innocent bystanders, by chemical weapons is a moral obscenity. By any standard it is inexcusable, and despite the excuses and equivocations that some have manufactured, it is undeniable.

The meaning of this attack goes beyond the conflict in Syria itself, and that conflict has already brought so much terrible suffering. This is about the large-scale, indiscriminate use of weapons that the civilized world long ago decided must never be used at all – a conviction shared even by countries that agree on little else. There is a clear reason that the world has banned entirely the use of chemical weapons. There is a reason the international community has set a clear standard and why many countries have taken major steps to eradicate these weapons. There is a reason why President Obama has made it such a priority to stop the proliferation of these weapons and lock them down where they do exist. There is a reason why President Obama has made clear to the Assad regime that this international norm cannot be violated without consequences. And there is a reason why no matter what you believe about Syria, all peoples and all nations who believe in the cause of our common humanity must stand up to assure that there is accountability for the use of chemical weapons so that it never happens again.

Last night after speaking with foreign ministers from around the world about the gravity of this situation, I went back and I watched the videos, the videos that anybody can watch in the social media, and I watched them one more gut-wrenching time. It is really hard to express in words the human suffering that they lay out before us. As a father, I can’t get the image out of my head of a man who held up his dead child, wailing while chaos swirled around him; the images of entire families dead in their beds without a drop of blood or even a visible wound; bodies contorting in spasms; human suffering that we can never ignore or forget. Anyone who can claim that an attack of this staggering scale could be contrived or fabricated needs to check their conscience and their own moral compass.

What is before us today is real, and it is compelling. So I also want to underscore that while investigators are gathering additional evidence on the ground, our understanding of what has already happened in Syria is grounded in facts informed by conscience and guided by common sense. The reported number of victims, the reported symptoms of those who were killed or injured, the firsthand accounts from humanitarian organizations on the ground like Doctors Without Borders and the Syria Human Rights Commission – these all strongly indicate that everything these images are already screaming at us is real, that chemical weapons were used in Syria.

Moreover, we know that the Syrian regime maintains custody of these chemical weapons. We know that the Syrian regime has the capacity to do this with rockets. We know that the regime has been determined to clear the opposition from those very places where the attacks took place. And with our own eyes, we have all of us become witnesses.

We have additional information about this attack, and that information is being compiled and reviewed together with our partners, and we will provide that information in the days ahead.

Our sense of basic humanity is offended not only by this cowardly crime but also by the cynical attempt to cover it up. At every turn, the Syrian regime has failed to cooperate with the UN investigation, using it only to stall and to stymie the important effort to bring to light what happened in Damascus in the dead of night. And as Ban Ki-moon said last week, the UN investigation will not determine who used these chemical weapons, only whether such weapons were used – a judgment that is already clear to the world.

I spoke on Thursday with Syrian Foreign Minister Muallim and I made it very clear to him that if the regime, as he argued, had nothing to hide, then their response should be immediate – immediate transparency, immediate access – not shelling. Their response needed to be unrestricted and immediate access. Failure to permit that, I told him, would tell its own story.

Instead, for five days, the Syrian regime refused to allow the UN investigators access to the site of the attack that would allegedly exonerate them. Instead, it attacked the area further, shelling it and systematically destroying evidence. That is not the behavior of a government that has nothing to hide. That is not the action of a regime eager to prove to the world that it had not used chemical weapons. In fact, the regime’s belated decision to allow access is too late, and it’s too late to be credible. Today’s reports of an attack on the UN investigators, together with the continued shelling of these very neighborhoods, only further weakens the regime’s credibility.

At President Obama’s direction, I’ve spent many hours over the last few days on the phone with foreign ministers and other leaders. The Administration is actively consulting with members of Congress and we will continue to have these conversations in the days ahead. President Obama has also been in close touch with the leaders of our key allies, and the President will be making an informed decision about how to respond to this indiscriminate use of chemical weapons. But make no mistake: President Obama believes there must be accountability for those who would use the world’s most heinous weapons against the world’s most vulnerable people. Nothing today is more serious and nothing is receiving more serious scrutiny." 

Monday, August 26, 2013

Pottery RevealS The Use Of Spice In European Prehistoric Cuisine

Our early ancestors had a taste for spicy food, new research led by the University of York has revealed.

Archaeologists at York, working with colleagues in Denmark, Germany and Spain, have found evidence of the use of spices in cuisine at the transition to agriculture. The researchers discovered traces of garlic mustard on the charred remains of pottery dating back nearly 7,000 years.
A map of Europe showing an inset of the study area and sites from which the pot residues were acquired;, including also the Near East and northern Africa indicating early contexts where spices have been recovered.
Figure 1 Early contexts from which spices have been recovered, with photomicrographs of globular sinuate phytoliths recovered from the pottery styles illustrated.
Credit:  doi:10.1371/journal.pone.0070583.g001

The silicate remains of garlic mustard (Alliaria petiolata) along with animal and fish residues were discovered through microfossil analysis of carbonised food deposits from pots found at sites in Denmark and Germany. The pottery dated from the Mesolithic-Neolithic transition from hunter-gathering to agriculture.

Previously scientists have analysed starches which survive well in carbonised and non-carbonised residues to test for the use of spices in prehistoric cooking. But the new research, which is reported in PLOS ONE, suggests that the recovery of phytoliths – silicate deposits from plants -- offers the additional possibility to identify leafy or woody seed material used as spices, not detectable using starch analysis. Phytoliths charred by cooking are more resilient to destruction.

Lead researcher Dr Hayley Saul, of the BioArCH research centre at at the University of York, said: "The traditional view is that early Neolithic and pre-Neolithic uses of plants, and the reasons for their cultivation, were primarily driven by energy requirements rather than flavour. As garlic mustard has a strong flavour but little nutritional value, and the phytoliths are found in pots with terrestrial and marine animal residues, our findings are the first direct evidence for the spicing of food in European prehistoric cuisine.

"Our evidence suggests a much greater antiquity to the spicing of foods in this region than is evident from the macrofossil record, and challenges the view that plants were exploited by hunter-gatherers and early agriculturalists solely for energy requirements, rather than taste."

The research was funded by the UK Arts and Humanities Research Council.

The research also involved scientists at the Institució Catalana de Recerca i Estudis Avançats, Institución Milá i Fontanals, Spanish National Research Council, Barcelona, Spain; the Danish Agency for Culture, Copenhagen, Denmark; the Institute of Prehistoric and Protohistoric Archaeology, University of Kiel, Kiel, Germany. And Stiftung Schleswig-Holsteinische Landesmuseen, Schloβ Gottorf, Schleswig, Germany.

Contacts and sources:
David Garner
University of York

Citation: Saul H, Madella M, Fischer A, Glykou A, Hartz S, et al. (2013) Phytoliths in Pottery Reveal the Use of Spice in European Prehistoric Cuisine.PLoS ONE 8(8): e70583. doi:10.1371/journal.pone.0070583

Key to map:   a) Menneville, France (Papaver somniferum L.), b) Eberdingen, Germany (Papaver somniferum L.), c) Seeberg, Switzerland (Papaver somniferum L.), d) Niederwil, Switzerland (Papaver somniferum L.), e) Swiss Lake Villages, Switzerland (Anethum graveolens L.), f) Cueva de los Murcielags, Spain (Papaver somniferumL.), g) Hacilar, Turkey (Capparis spinosa L.), h) Tell Abu Hureya, Syria (Caparis spinosa L.), i) Tell ed-Der, Syria (Coriandrum sativum L. and Cuminum cyminum L.), j) Khafaji, Iraq (Cruciferae family), k) Tell Aswad, Syria (Capparis spinosa L.), l) Nahal Hemar Cave, Israel (Coriandrum sativum L.), m) Tutankhamun's tomb, Egypt (Coriandrum sativum L.), n) Tomb of Kha, Egypt (Cuminum cyminum L.), o) Tomb of Amenophis II, Egypt (Anethum graveolens L.), p) Hala Sultan Tekke, Cyprus (Capparis spinosa L.), q) Heilbronn, Germany (Papaver somniferum L.), r) Zeslawice, Poland (Papaver somniferum L.) [compiled using 8–17]. B) Hunter-gatherer pointed-based vessel (on the left) and Early Neolithic flat-based vessel (on the right). C) Scanning Electron Microscope image of a globular sinuate phytolith embedded in a food residue, D) optical light microscope image of modern Alliaria petiolata globular sinuate phytoliths, and E) optical light microscope image of archaeological globular sinuate phytolith examples.

Chelyabinsk Meteorite Had Previous Collision Or Flew Too Close To The Sun

The Chelyabinsk meteorite either collided with another body in the solar system or came too close to the Sun before it fell to Earth, according to research announced today (Tuesday 27th August) at the Goldschmidt conference in Florence.

A team from the Institute of Geology and Mineralogy (IGM) in Novosibirsk have analysed fragments of the meteorite, the main body of which fell to the bottom of the Chebarkul Lake near Chelyabinsk on 15 February this year.

Although all of the fragments are composed of the same minerals, the structure and texture of some fragments show that the meteorite had undergone an intensive melting process before it was subjected to extremely high temperatures on entering the Earth's atmosphere.

"The meteorite which landed near Chelyabinsk is a type known as an LL5 chondrite and it's fairly common for these to have undergone a melting process before they fall to Earth," says Dr Victor Sharygin from IGM, who is presenting the research at the Goldschmidt conference. "This almost certainly means that there was a collision between the Chelyabinsk meteorite and another body in the solar system or a near miss with the Sun."

Fragment of Chelyabinsk meteorite, showing the fusion crust -- the result of a previous collision or near miss with another planetary body or with the sun.

Credit: Dr. Victor Sharygin

Based on their colour and structure, the IGM researchers have divided the meteorite fragments into three types: light, dark and intermediate. The lighter fragments are the most commonly found, but the dark fragments are found in increasing numbers along the meteorite's trajectory, with the greatest number found close to where it hit the Earth.

The dark fragments include a large proportion of fine-grained material, and their structure, texture and mineral composition shows they were formed by a very intensive melting process, likely to have been either a collision with another body or proximity to the Sun. This material is distinct from the 'fusion crust' - the thin layer of material on the surface of the meteorite that melts, then solidifies, as it travels through the Earth's atmosphere.

"Of the many fragments we've been analysing, only three dark samples show strong evidence of earlier metamorphism and melting," says Dr Sharygin. "However, many fragments of the meteorite were picked up by members of the public, so it's impossible to say how large a portion of the meteorite was affected. We hope to find out more once the main body of the meteorite is raised from Chebarkul Lake."

The fine-grained material of the dark fragments also differs from the other samples as it commonly contains spherical 'bubbles' which are either encrusted with perfect crystals of oxides, silicates and metal or filled with metal and sulfide.

Surprisingly, the IGM team also found small quantities of platinum group elements in the meteorite's fusion crust. The team are only able to identify these elements as an alloy of osmium, iridium and platinum, but its presence is unusual as the fusion crust is formed over too short a time period for these elements to easily accumulate.

"Platinum group elements usually occur as trace elements dispersed in meteorite minerals, but we found them as a nanometer-sized mineral (100-200 nm) in a metal-sulfide globule in the fusion crust of the Chelyabinsk meteorite," explains Dr Sharygin. "We think the appearance (formation) of this platinum group mineral in the fusion crust may be linked to compositional changes in metal-sulfide liquid during remelting and oxidation processes as the meteorite came into contact with atmospheric oxygen."

The findings are part of ongoing research into the meteorite, using a scanning microscope, electron microprobe and gas chromatography-mass spectrometry, through which the IGM team are producing a detailed mineral analysis of the Chelyabinsk meteorite.


Contacts and sources:
European Association of Geochemistry  

Scripps Scientists Report Breakthrough in DNA Editing Technology

Scientists at The Scripps Research Institute (TSRI) have found a way to apply a powerful new DNA-editing technology more broadly than ever before.

“This is one of the hottest tools in biology, and we’ve now found a way to target it to any DNA sequence,” said Carlos F. Barbas III, the Janet and Keith Kellogg II Chair in Molecular Biology and Professor in the Department of Chemistry at TSRI.

Structure of DNA double helix
Credit:  Wikipedia

The breakthrough concerns a set of designer DNA-binding proteins called TALEs, which biologists increasingly use to turn on, turn off, delete, insert or even rewrite specific genes within cells—for scientific experiments and also for potential biotech and medical applications, including treatments for genetic diseases.

TALE-based methods had been considered useful against only a fraction of the possible DNA sequences found in animals and plants, but the new finding removes that limitation.

Barbas and his team report their finding on August 26, 2013 in an advance online edition of the journal Nucleic Acids Research.

Useful Tools

Molecular biologists have long dreamed of being able to manipulate DNA in living cells with ease and precision, and by now that dream is nearly a reality. TALE-based designer proteins, introduced just a few years ago, are arguably the most user-friendly and precise DNA-directed tools that have yet been invented.

Designer TALEs (transcription-activator-like effectors) are based on natural TALE proteins that are produced by some plant-infecting bacteria. These natural TALEs help bacteria subvert their plant hosts by binding to specific sites on plant DNA and boosting the activity of certain genes—thereby enhancing the growth and survival of the invading bacteria.

Scientists have found that they can easily engineer the DNA-grabbing segment of TALE proteins to bind precisely to a DNA sequence of interest. Typically they join that DNA-binding segment to another protein segment that can perform some desired function at the site of interest—for example, an enzyme fragment that cuts through DNA. Collectively the Barbas laboratory and others in this field have already engineered thousands of these powerful TALE-based DNA-editing proteins.

However, TALE-based DNA-editing has been seen to have a significant limitation. Virtually all the natural TALE proteins that have been discovered so far target sequences of DNA whose transcription begins with the nucleoside thymidine—the letter “T” in the four-letter DNA code. Structural studies have hinted that natural TALE proteins can’t bind well to DNA without that initial T. Molecular biologists thus have widely assumed that the same “T restriction” rule applies to any artificial TALE protein they might engineer.

“Yet no one has investigated thoroughly whether that initial thymidine is truly required for the variety of TALE designer proteins and enzymes that now exist,” said Brian M. Lamb, a research associate in the Barbas Laboratory who was first author of the new study.

Questioning Assumptions

Lamb started by evaluating how well TALE-based proteins function against their usual DNA targets when the first DNA letter is switched from a T to one of the other three nucleosides (A, G or C). Using a library of natural and engineered TALE proteins, he found strong evidence in favor of the “T restriction” rule. “There was an orders-of-magnitude difference—some of the TALE proteins we evaluated lost as much as 99.9% of their activity when we changed that first nucleoside base,” said Lamb.

But he wasn’t ready to give up on the possibility of designing more broadly useful TALE proteins. For this he adapted a “directed evolution” technique developed last year by Andrew C. Mercer, who at the time was a research associate in the Barbas laboratory. First, Lamb generated a large library of novel TALE proteins that vary randomly in the structures they hypothesized to grab the initial nucleoside. He then put these new TALEs through a series of tests, to select—in a speeded up version of natural evolution—those that work adequately even with a non-T nucleoside at the start of their target DNA sequence.

In this way, he found several new TALE protein architectures that aren’t held back by the T restriction. One prefers to bind to DNA that begins not with a T nucleoside but with a G (guanosine). Others bind well enough to sequences that start with any of the four DNA nucleosides. Lamb found that these non-T-restricted TALEs work as designed when conjoined, for example, to DNA-cutting enzyme fragments. “Essentially we abolished the T requirement,” said Lamb.

“That means that the number of DNA sites we can target with TALE-based proteins, and the precision with which we can target within any given gene, have gone up dramatically,” Barbas said.

A Multitude of Potential Uses

He and his team plan to follow up the discovery mostly by using the new unrestricted TALE-based proteins as tools for developing potential gene therapies. But the removal of the “T restriction” on TALE-based DNA editing should have a positive impact also on basic molecular biology, biotechnology, stem cell medicine, and nanotechnology when they are combined for example with DNA origami. Indeed any application that requires the manipulation of DNA in living cells or even the construction of protein-DNA machines should benefit from this breakthrough.

“The number of potential uses of this technology is probably more than any one person can imagine,” Barbas said.

The study, “Directed Evolution of the TALE N-Terminal Domain for Recognition of All 5’ Bases,” was funded in part by the National Institutes for Health Pioneer Award (grant DP1CA174426). For see the study, seehttp://nar.oxfordjournals.org/content/early/2013/08/26/nar.gkt754.full-text-lowres.pdf


Contacts and sources:
Mika Ono
Scripps Research Institute

Concepts Art For Living In Space: Now And From the 1970s

The Elysium film has reignited interest in the concept of human settlers living off the surface of our planet inside enormous space stations and extensive colonies. Film director Neill Blomkamp's Elysium colony was artistically portrayed as a gigantic toroidal structure, one of the most common design concepts depicted in imaginative illustrations produced over many decades. 

Part of the rim of a toroidal space colony, including nearby space vehicles.
Part of the rim of a toroidal space colony, including nearby space vehicles.
Image Credit: NASA

Space theorists predict that the first space settlements will be designed to orbit Earth, preceding those that will spread out across the solar system to take advantage of water discovered on other planetary bodies and resource materials available on sizable asteroids. 

Double cylindrical colony: exterior view. Rick Guidice, mid-1970s.
Image credit: NASA

Regardless of their placement, each space-based settlement will need to be engineered, constructed and operated as an independent biosphere in which all water, oxygen and waste material must be infinitely recycled. 
 
Since its inception in 1994, the NASA Space Settlement Contest has given thousands of students the opportunity to conceive their own space settlement design, using their skills in art, science, technology, engineering, and mathematics. All entries are judged in a single day. In addition to the prestige that comes with winning the contest, winners are invited by contest founder and organizer Al Globus to visit NASA Ames Research Center in Mountain View, California.

"Hyperion Space Settlement," 2011 Grand Prize. Punjab, India. Design team: Gaurav Kumar, Deepak Talwar, Harman Jot Singh Walia, Mahiyal B. Singh, Kaenat Seth, Ishaan Mehta, and Navdeep Singh Makkar. The team also won the NSS Bruce M. Clark, Jr. Memorial Space Settlement Award.
Hyperion Space Settlement - 2011 Grand Prize winner
Image credit: NASA

The NASA Space Settlement Contest has continued to benefit the global public for almost twenty years. The project has been sustained by the efforts of dedicated NASA Ames personnel, and by making cost-effectiveness a top priority. Educational materials are provided for students around the world at little to no cost, much of it consisting of public domain content available online.

The opportunity to participate in the contest has enabled students to become involved in their own projects and in STEM (Science, Technology, Engineering, Mathematics) pursuits. For many, it has proved to be a life-altering experience. Numerous participants have cited the NASA Space Settlement Contest as having inspired them to pursue careers in the STEM fields. Horia-Mihail Teodorescu, a contest participant from Romania, recalls, “While the contest has encouraged me to learn much more about the sciences than I would have imagined, and offered an unforgettable teamwork experience, what I would consider most important is that, through its interdisciplinarity (sic), the contest has taught me more about myself. Through its act of teaching, it has had a major impact on my development and on my life.”

Unity Settlement
 Unity Settlement
Credit: Student: Diptam Roy Choudhury,  Kolkata, India
 
Participants benefit from the responsibility and demands of this prestigious competition. The students who enter the contest become deeply committed to their projects, and working out their designs requires them to develop their STEM skills and artistic talents to the fullest extent.

Aresam," 2010 Grand Prize. Durango High School. Colorado, United States. Design team: The Durango Aerospace Design Team under the instruction of Mr. Daniel Gamer. 
Aresam - 2010 Grand Prize entry
Image credit: NASA

Most entries are submitted by participants from the United States, although a sweeping number of grand prize winners are from other countries, most notably Romania. All entries must be submitted in English, but despite this barrier, Romania won or tied for the grand prize in 2003, 2004, 2005, 2007, and 2008. This can be partly attributed to winning entries from Horia-Mihail Teodorescu, quoted above, who won in both 2003 and 2005, but credit should also be given to his advisor and father, Prof. Horia Nicolai Teodorescu, who has made participation in the NASA Space Settlement Contest a major activity in Romania.

Developing new ideas for space settlements is an effective way to unite STEM skills and the arts into an engaging and inspirational curriculum. A large project such as designing a space habitat gives students the opportunity to embrace learning and claim ownership on the knowledge they have acquired. It is NASA's hope and intention that the Space Settlement Contest will continue to inspire the next generation of scientists and engineers from all over the world for many years to come.

Over the last 26 years, NASA's Ames Research Center in Silicon Valley, Calif., has organized a global Space Settlement Design Contest to encourage students around the world to tackle the many challenging issues critical to designing habitable space colony environments and transportation systems.

› NASA Space Colony Art from the 1970s
 
Contacts and sources:
Yvonne Clearwater Art gallery on NASA Space Settlement Design Contest
NASA Space Settlement Design Contest information and winning entries
Space colony art from the 1970s