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Monday, May 22, 2017

Monash Researchers Uncover New Gravitational Wave Characteristics

Monash University researchers have identified a new concept - 'orphan memory' - which changes the current thinking around gravitational waves.ver

The research, by the Monash Centre for Astrophysics, was published recently in Physical Review Letters.

Einstein's theory of general relativity predicts that cataclysmic cosmic explosions stretch the fabric of spacetime.

The stretching of spacetime is called 'gravitational waves.' After such an event, spacetime does not return to its original state. It stays stretched out. This effect is called 'memory.'

Gravitational waves are ripples in space-time, represented by the green grid, produced by accelerating bodies such as interacting supermassive black holes. These waves affect the time it takes for radio signals from pulsars to arrive at Earth. 
Gravitational waves are ripples in space-time, represented by the green grid
Credit: David Champion

The term 'orphan' alludes to the fact that the parent wave is not directly detectable.

"These waves could open the way for studying physics currently inaccessible to our technology," said Monash School of Physics and Astronomy Lecturer, Dr Eric Thrane, one of the authors of the study, together with Lucy McNeill and Dr Paul Lasky.

"This effect, called 'memory' has yet to be observed," said Dr Thrane.

Gravitational-wave detectors such as LIGO only 'hear'' gravitational waves at certain frequencies, explains lead author Lucy McNeill.

"If there are exotic sources of gravitational waves out there, for example, from micro black holes, LIGO would not hear them because they are too high-frequency," she said.

"But this study shows LIGO can be used to probe the universe for gravitational waves that were once thought to be invisible to it."

Study co-author Dr Lasky said LIGO won't be able to see the oscillatory stretching and contracting, but it will be able to detect the memory signature if such objects exist.

The researchers were able to show that high-frequency gravitational waves leave behind a memory that LIGO can detect.

"This realisation means that LIGO may be able to detect sources of gravitational waves that no one thought it could," said Dr Lasky.

Contacts and sources:
Silvia Dropulich
Monash University

The full paper is available at: https://journals.aps.org/prl/abstract/10.1103/PhysRevLett.118.181103

Kepler Telescope Discovers Details of TRAPPIST-1 System's Outermost Planet

A University of Washington-led international team of astronomers has used data gathered by the Kepler Space Telescope to observe and confirm details of the outermost of seven exoplanets orbiting the star TRAPPIST-1.

They confirmed that the planet, TRAPPIST-1h, orbits its star every 18.77 days, is linked in its orbital path to its siblings and is frigidly cold. Far from its host star, the planet is likely uninhabitable — but it may not always have been so.

UW doctoral student Rodrigo Luger is lead author on a paper published May 22 in the journal Nature Astronomy.

“TRAPPIST-1h was exactly where our team predicted it to be,” Luger said. The researchers discovered a mathematical pattern in the orbital periods of the inner six planets, which was strongly suggestive of an 18.77 day period for planet h.

The animation shows a simulation of the planets of TRAPPIST-1 orbiting for 90 Earth-days. After 15 Earth days, the animation focuses only on the outer three planets: TRAPPIST-1f, TRAPPIST-1g, TRAPPIST-1h. The motion freezes each time two adjacent planets pass each other; an arrow appears pointing to the location of the third planet. This complex but predictable pattern, called an orbital resonance, occurs when planets exert a regular, periodic gravitational tug on each other as they orbit their star. The three-body resonance of the outer three planets causes the planets to repeat the same relative positions, and expecting such a resonance was used to predict the orbital period of TRAPPIST-1h.

by Daniel Fabrycky / University of Chicago; with reference to Luger et al. 2017, Nature Astronomy

“It had me worried for a while that we were seeing what we wanted to see. Things are almost never exactly as you expect in this field — there are usually surprises around every corner, but theory and observation matched perfectly in this case.”

TRAPPIST-1 is a middle-aged, ultra cool dwarf star, much less luminous than the sun and only a bit larger than the planet Jupiter. The star, which is nearly 40 light-years or about 235 trillion miles away in the constellation of Aquarius, is named after the ground-based Transiting Planets and Planetesimals Small Telescope (TRAPPIST), the facility that first found evidence of planets around it in 2015.

The TRAPPIST survey is led by Michael Gillon of the University of Liège, Belgium, who is also a coauthor on this research. In 2016, Gillon’s team announced the detection of three planets orbiting TRAPPIST-1 and this number was upped to seven in a subsequent 2017 paper. Three of TRAPPIST-1’s planets appear to be within the star’s habitable zone, that swath of space around a star where a rocky planet could have liquid water on its surface, thus giving life a chance.

Such exoplanets are detected when they transit, or pass in front of, their host star, blocking a measurable portion of the light. Gillon’s team was able to observe only a single transit for TRAPPIST-1h, the farthest-out of the star’s seven progeny, prior to the data analyzed by Luger’s team.

Luger led a multi-institution international research team that studied the TRAPPIST-1 system more closely using 79 days of observation data from K2, the second mission of the Kepler Space Telescope. The team was able to observe and study four transits of TRAPPIST-1h across its star.

Artist's impression of TRAPPIST-1 being transited by two of its seven known planets
File:PIA21429 - Transit Illustration of TRAPPIST-1 (cropped).jpg
Credit: NASA/JPL-Caltech 

The team used the K2 data to further characterize the orbits of the other six planets, help rule out the presence of additional transiting planets, and determine the rotation period and activity level of the star. They also discovered that TRAPPIST-1’s seven planets appear linked in a complex dance known as an orbital resonance where their respective orbital periods are mathematically related and slightly influence each other.

“Resonances can be tricky to understand, especially between three bodies. But there are simpler cases that are easier to explain,” Luger said. For instance, closer to home, Jupiter’s moons Io, Europa and Ganymede are set in a 1:2:4 resonance, meaning that Europa’s orbital period is exactly twice that of Io, and Ganymede’s is exactly twice that of Europa.

These relationships, Luger said, suggested that by studying the orbital velocities of its neighbor planets they could predict the exact orbital velocity, and hence also orbital period, of TRAPPIST-1h even before the K2 observations. Their theory proved correct when they located the planet in the K2 data.

TRAPPIST-1’s seven-planet chain of resonances established a record among known planetary systems, the previous holders being the systems Kepler-80 and Kepler-223, each with four resonant planets. The resonances are “self-correcting,” Luger said, such that if one planet were to somehow be nudged off course, it would lock right back into resonance. “Once you’re caught into this kind of stable resonance, it’s hard to escape,” he said.

All of this, Luger said, indicates that these orbital connections were forged early in the life of the TRAPPIST-1 system, when the planets and their orbits were not fully formed.

“The resonant structure is no coincidence, and points to an interesting dynamical history in which the planets likely migrated inward in lock-step,” Luger said. “This makes the system a great testbed for planet formation and migration theories.”

It also means that while TRAPPIST-1h is now extremely cold — with an average temperature of 173 Kelvin (minus 148 F) — it likely spent several hundred million years in a much warmer state, when its host star was younger and brighter.

“We could therefore be looking at a planet that was once habitable and has since frozen over, which is amazing to contemplate and great for follow-up studies,” Luger said.

Luger said he has been working with data from the K2 mission for a while now, researching ways to reduce “instrumental noise” in its data resulting from broken reaction wheels — small flywheels that help position the spacecraft — that can overwhelm planetary signals.

TRAPPIST-1 system compared to the Solar System; all seven planets of TRAPPIST-1 could fit inside the orbit of Mercury
File:PIA21428 - TRAPPIST-1 Comparison to Solar System and Jovian Moons.jpg
Credit: NASA/JPL-Caltech 

“Observing TRAPPIST-1 with K2 was an ambitious task,” said Marko Sestovic, a doctoral student at the University of Bern and second author of the study. In addition to the extraneous signals introduced by the spacecraft’s wobble, the faintness of the star in the optical (the range of wavelengths where K2 observes) placed TRAPPIST-1h “near the limit of what we could detect with K2,” he said. To make matters worse, Sestovic said, one transit of the planet coincided with a transit of TRAPPIST-1b, and one coincided with a stellar flare, adding to the difficulty of the observation. “Finding the planet was really encouraging,” Luger said, “since it showed we can still do high-quality science with Kepler despite significant instrumental challenges.”

Luger’s UW co-authors are astronomy doctoral students Ethan Kruse and Brett Morris, post-doctoral researcher Daniel Foreman-Mackey and professor Eric Agol (Guggenheim Fellow). Agol separately helped confirm the approximate mass of TRAPPIST-1 planets with a technique he and colleagues devised called “transit timing variations” that describes planets’ gravitational tugs on one another.

Luger said the TRAPPIST-1 system’s relative nearness “makes it a prime target for follow-up and characterization with current and upcoming telescopes, which may be able to give us information about these planets’ atmospheric composition.”

Contributing to this discovery are researchers at the University of Bern in Switzerland; Paris Diderot and Paris Sorbonne Universities and the CEA Saclay in France; the University of Liège in Belgium; the University of Chicago; the University of California, San Diego; California Institute of Technology; the University of Bordeaux in France; the University of Cambridge in England; NASA’s Ames Research Center, Goddard Space Flight Center, and Johnson Space Center; Massachusetts Institute of Technology; the University of Central Lancashire in England; King Abdulaziz University in Saudi Arabia; Cadi Ayyad University in Morocco; and the University of Geneva in Switzerland.

The research was funded by the NASA Astrobiology Institute via the UW-based Virtual Planetary Laboratory as well as a National Science Foundation Graduate Student Research Fellowship, the Swiss National Science Foundation, the Simons Foundation, the European Research Council and the UK Science and Technology Facilities Council, among other agencies.

Contacts and sources:
Peter Kelley
University of Washington

Study Shows How Radioactive Decay Could Support Extraterrestrial Life

 In the icy bodies around our solar system, radiation emitted from rocky cores could break up water molecules and support hydrogen-eating microbes. 

To address this cosmic possibility, a University of Texas at San Antonio (UTSA) and Southwest Research Institute (SwRI) team modeled a natural water-cracking process called radiolysis. They then applied the model to several worlds with known or suspected interior oceans, including Saturn's moon Enceladus, Jupiter's moon Europa, Pluto and its moon Charon, as well as the dwarf planet Ceres.

A University of Texas at San Antonio (UTSA) and Southwest Research Institute (SwRI) team modeled a natural water-cracking process called radiolysis. They applied the model to the icy bodies around our solar system to show how radiation emitted from rocky cores could break up water molecules and support hydrogen-eating microbes.
model of a natural water-cracking process called radiolysis
Image Courtesy of Southwest Research Institute

"The physical and chemical processes that follow radiolysis release molecular hydrogen (H2), which is a molecule of astrobiological interest," said Alexis Bouquet, lead author of the study published in the May edition of Astrophysical Journal Letters. Radioactive isotopes of elements such as uranium, potassium, and thorium are found in a class of rocky meteorites known as chondrites. The cores of the worlds studied by Bouquet and his co-authors are thought to have chondrite-like compositions. Ocean water permeating the porous rock of the core could be exposed to ionizing radiation and undergo radiolysis, producing molecular hydrogen and reactive oxygen compounds.

Bouquet, a student in the joint doctoral program between UTSA's Department of Physics and Astronomy and SwRI's Space Science and Engineering Division, explained that microbial communities sustained by H2 have been found in extreme environments on Earth. These include a groundwater sample found nearly 2 miles deep in a South African gold mine and at hydrothermal vents on the ocean floor. That raises interesting possibilities for the potential existence of analogous microbes at the water-rock interfaces of ocean worlds such as Enceladus or Europa.

"We know that these radioactive elements exist within icy bodies, but this is the first systematic look across the solar system to estimate radiolysis. The results suggest that there are many potential targets for exploration out there, and that's exciting," says co-author Dr. Danielle Wyrick, a principal scientist in SwRI's Space Science and Engineering Division.

One frequently suggested source of molecular hydrogen on ocean worlds is serpentinization. This chemical reaction between rock and water occurs, for example, in hydrothermal vents on the ocean floor.

In the icy bodies around our solar system, radiation emitted from rocky cores could break up water molecules and support hydrogen-eating microbes. A University of Texas at San Antonio (UTSA) and Southwest Research Institute (SwRI) team modeled a natural water-cracking process called radiolysis and applied the model to Europa (pictured) and several other worlds with known or suspected interior oceans.
Image: Europa
Image Courtesy of NASA/JPL-Caltech/SETI Institute

The key finding of the study is that radiolysis represents a potentially important additional source of molecular hydrogen. While hydrothermal activity can produce considerable quantities of hydrogen, in porous rocks often found under seafloors, radiolysis could produce copious amounts as well.

Radiolysis may also contribute to the potential habitability of ocean worlds in another way. In addition to molecular hydrogen, it produces oxygen compounds that can react with certain minerals in the core to create sulfates, a food source for some kinds of microorganisms.

"Radiolysis in an ocean world's outer core could be fundamental in supporting life. Because mixtures of water and rock are everywhere in the outer solar system, this insight increases the odds of abundant habitable real estate out there," Bouquet said.

Contacts and sources:
Deb Schmid
Southwest Research Institute (SwRI)

Co-authors of the article, "Alternative Energy: Production of H2 by Radiolysis of Water in the Rocky Cores of Icy Bodies," are SwRI's Dr. Christopher R. Glein, Wyrick, and Dr. J. Hunter Waite, who also serves as a UTSA adjoint professor.

3.3 Million-Year-Old Fossil Reveals the Antiquity of the Human Spine

For more than 3 million years, Selam lay silent and still. Eager to tell her story, the almost perfect fossil skeleton of a 2 1/2 year-old toddler was discovered at Dikika, Ethiopia -- and she had a lot to say. 

An international research team slowly chipped away at the sandstone surrounding Selam at the National Museums of Ethiopia to reveal something remarkable -- even though millions of years have passed, she's a lot like us. Selam, which means "peace" in the Ethiopian Amharic language, was an early human relative from the species Australopithecus afarensis -- the same species as the famous Lucy skeleton.

The almost perfect fossil skeleton of a 2 1/2 year-old toddler was discovered at Dikika, Ethiopia.
Credit: Zeray Alemseged, University of Chicago

The findings, published this week in the Proceedings of the National Academy of Science, indicate that Selam possesses the most complete spinal column of any early fossil human relative, and her vertebral bones, neck and rib cage are mainly intact. This new research demonstrates that portions of the human skeletal structure were established millions of years earlier than previously thought.

Many features of the human spinal column and rib cage are shared among primates. The human spine reflects the distinctive mode of walking upright on two feet. Among the distinctive features is that humans have fewer rib-bearing vertebrae, bones of the back, than those of our closest relatives, and more vertebrae in the lower back allowing motions for walking effectively. When and how this pattern evolved has been unknown because complete sets of vertebrae are rarely preserved in the fossil record.

Selam, possesses the most complete spinal column of any early fossil human relative, and her vertebral bones, neck and rib cage are mainly intact.
Credit: Zeray Alemseged, University of Chicago

"For many years we have known of fragmentary remains of early fossil species that suggest that the shift from rib-bearing, or thoracic, vertebrae to lumbar, or lower back, vertebrae was positioned higher in the spinal column than in living humans, but we have not been able to determine how many vertebrae our early ancestors had," said Carol Ward, a Curators Distinguished Professor of Pathology and Anatomical Sciences in the MU School of Medicine, and lead author on the study. "Selam has provided us the first glimpse into how our early ancestors' spines were organized."

Selam was discovered by Zeresenay Alemseged, a professor in the Department of Organismal Biology and Anatomy at the University of Chicago. The skeleton was surrounded by sandstone, and Alemseged and his team have been preparing the delicate fossil for 13 years at the National Museum of Ethiopia.

"Continued and painstaking research on the Selam shows that the general structure of the human spinal column emerged over 3.3 million years ago, shedding light on one of the hallmarks of human evolution," Alemseged said. "This type of preservation is unprecedented, particularly in a young individual whose vertebrae are not yet fully fused."

Credit: University Of Missouri-Columbia

In order to be analyzed, Selam had to take a trip. She traveled to the European Synchrotron Radiation Facility in Grenoble, France, where Alemseged and the research team used high-resolution imaging technology to visualize the bones. Scans were later sent to Ward at MU for further comparative studies.

"This technology provides the opportunity to virtually examine aspects of the vertebrae otherwise unattainable from the original specimen," said coauthor of the study Fred Spoor, a professor of evolutionary anatomy in the Department of Biosciences at the University College London.

Ward says the scans indicated that Selam had the distinctive thoracic-to-lumbar joint transition found in other fossil human relatives, but the specimen is the first to show that, like modern humans, our earliest ancestors had only twelve thoracic vertebrae and twelve pairs of ribs, which is fewer than in most apes.

"This unusual early human configuration may be a key in developing more accurate scenarios concerning the evolution of bipedality and modern human body shape," said Thierra Nalley, an assistant professor of anatomy at Western University of Health Sciences in Pomona, California, also an author of the paper.

Contacts and sources:
Jeff Sossamon
University Of Missouri-Columbia

The study, "Thoracic Vertebral Count and Thoracolumbar Transition in Australopithecus afarensis" was published in the Proceedings of the National Academy of Science. Funding for the research was provided by Margaret and Will Hearst, the National Science Foundation and the European Synchrotron Radiation Facility. The content is solely the responsibility of the authors and does not necessarily represent the official views of the funding agencies.

Air Pollution Can Interfere with Sleep

High levels of air pollution over time may get  in the way of a good night's sleep, according to new research presented at the American Thoracic Society (ATS) 2017 International Conference.

"Prior studies have shown that air pollution impacts heart health and affects breathing and lung function, but less is known about whether air pollution affects sleep," said lead author Martha E. Billings, MD, MSc, assistant professor of medicine at the University of Washington. "We thought an effect was likely given that air pollution causes upper airway irritation, swelling and congestion, and may also affect the central nervous system and brain areas that control breathing patterns and sleep."

Image result for air pollution
Credit: Wikimedia Commons

The researchers analyzed data from 1,863 participants (average age 68) in the Multi-Ethnic Study of Atherosclerosis (MESA) who also enrolled in both MESA's Sleep and Air Pollution studies. The researchers looked at two of the most common air pollutants: NO2 (traffic-related pollutant gas) and PM2.5, or fine-particle pollution. Using air pollution measurements gathered from hundreds of MESA Air and Environmental Protection Agency monitoring sites in six U.S. cities, plus local environment features and sophisticated statistical tools, the research team was able to estimate air pollution exposures at each participant's home at two time points: one year and five years.

Wrist actigraphy, which measures small movements, provided detailed estimates of sleep and wake patterns over seven consecutive days. This was used to calculate "sleep efficiency"--a measure of the percentage of time in bed spent asleep vs. awake. Researchers found that the sleep efficiency of the lowest 25 percent of participants was 88 percent or less. The research team studied if pollution exposures differed among those in this low sleep efficiency group.

The population was divided into "fourths" according to levels of pollution. The quarter of those who experienced the highest levels of pollution was compared to the quarter with the lowest levels.

The study found:

The group with the highest levels of NO2 over five years had an almost 60 percent increased likelihood of having low sleep efficiency compared to those with the lowest NO2 levels. The group with the highest exposures to small particulates (PM2.5) had a nearly 50 percent increased likelihood of having low sleep efficiency.

The authors adjusted for a range of factors, including age, body mass, obstructive sleep apnea, race/ethnicity, income and smoking status. They also adjusted for neighborhood socioeconomic status.

The researchers were particularly interested in chronic exposure to air pollution and what that long-term exposure might mean for sleep health. "There may be acute sleep effects to short-term exposure to high pollution levels as well, but we lacked the data to study that link," Dr. Billings said, noting that the parent MESA study is investigating the chronic effects of air pollution on cardiovascular health.

"These new findings indicate the possibility that commonly experienced levels of air pollution not only affect heart and lung disease, but also sleep quality. Improving air quality may be one way to enhance sleep health and perhaps reduce health disparities," Dr. Billings said.

Future studies, she added, need to explore the association between other air pollutants and sleep, the mechanisms by which these pollutants may disrupt sleep patterns and whether traffic noise is the driving factor contributing to poor sleep quality.

Contacts and sources:
Martha E. Billings, MD, MSc
University of Washington

Dacia Morris
American Thoracic Society (ATS) 

Six Billion-Year-Old Space Signal Captured by New Telescope

A CSIRO telescope has found its first 'fast radio burst' from space after less than four days of searching.

The discovery came so quickly that the telescope, the Australian Square Kilometre Array Pathfinder (ASKAP) near Geraldton in Western Australia, looks set to become a world champion in this fiercely competitive area of astronomy.

The new fast radio burst finding was published today in The Astrophysical Journal Letters. 'Fast radio bursts' or FRBs are short, sharp spikes of radio waves lasting a few milliseconds.

Credit: © Alex Cherney/terrastro.com

They appear to come from powerful events billions of light-years away but their cause is still a mystery. The first was discovered in 2007 and only two dozen have been found since.

The discovery of the new burst, FRB170107, was made by CSIRO's Dr Keith Bannister and his colleagues from CSIRO, Curtin University and the International Centre for Radio Astronomy Research (ICRAR) while using just eight of the telescope's 36 dishes.

The discovery is the culmination of a decade of science and engineering development by CSIRO and Curtin University.

"We can expect to find one every two days when we use 12 dishes, our standard number at present," Dr Bannister said.

To make the most recent detection, the researchers used an unusual strategy.

"We turned the telescope into the Sauron of space – the all-seeing eye," Dr Bannister said, referring to the dark overlord in Tolkien's "Lord of the Rings".

Usually ASKAP's dishes all point at the one part of sky. But they can be made to point in slightly different directions, like the segments of a fly's eye.

This multiplies the amount of sky the telescope can see. Eight ASKAP dishes can see 240 square degrees at once – about a thousand times the area of the full Moon.

The new burst was found as part of a research project called CRAFT (Commensal Real-time ASKAP Fast Transients survey), which is led jointly by Dr Bannister and Dr Jean-Pierre Macquart from the Curtin University node of ICRAR.

The signal of FRB 170107, found using CSIRO’s ASKAP radio telescope in less than four days of looking. 
Credit: ©K. Bannister et. al

Dr Macquart said the new burst was extremely bright and that finding it was "as easy as shooting fish in a barrel".

FRB170107 came from the edge of the constellation Leo. It appears to have travelled through space for six billion years before slamming into the WA telescope at the speed of light.

The burst's brightness and its apparent distance mean that the energy involved is enormous, making it extremely challenging to explain.

"We've made a hard problem even harder," said Dr Ryan Shannon (CSIRO, Curtin University and ICRAR), who analysed the burst's strength and position.

CSIRO Chief Executive Dr Larry Marshall said the FRB detection was a sign of the full potential of ASKAP.

"Radio astronomy has a long history of innovation in high-speed communications, and this unique capability is embedded into ASKAP – from the receiver to the signal processing – making it a uniquely powerful instrument for astronomy," Dr Marshall said.

In addition to the discovery of the new burst, Dr Bannister has a big reward – a happy family.

He'd been telling his three kids for months about his plans.

"Every day as I left for work they'd ask, 'Are you going to find a radio burst today, Daddy?'" he said.

And when it finally happened, "they were too excited for words".

"They just looked at me, smiled, and gave me a great big hug!"

Contacts and sources:
Gabby Russell

New Planetary Object "Synestia" Formed When Two Planets Collide

Scientists suggest in a new study the existence of a planetary object called a “synestia,” a huge, spinning, donut-shaped mass of hot, vaporized rock, formed as planet-sized objects smash into each other.

At one point early in its history, Earth was likely a synestia, said Sarah Stewart, a planetary scientist at the University of California Davis and co-author of the new study in the Journal of Geophysical Research: Planets, a journal of the American Geophysical Union.

The structure of a planet, a planet with a disk and a synestia, all of the same mass.

Credit: Simon Lock and Sarah Stewart.

Stewart and Simon Lock, a graduate student at Harvard University in Cambridge, Massachusetts and lead author of the new study, explore how planets can form from a series of giant impacts. Current theories of planet formation hold that rocky planets such as Earth, Mars and Venus formed early in the solar system when smaller objects smashed into each other.

These collisions were so violent that the resulting bodies melted and partially vaporized, eventually cooling and solidifying to the nearly spherical planets we know today.

Lock and Stewart are particularly interested in collisions between spinning objects. A rotating object has angular momentum, which must be conserved in a collision. Think of a skater spinning on ice: if she extends her arms, she slows her rate of spin. To spin faster, she holds her arms close by her side, but her angular momentum stays constant.

Now consider two skaters turning on ice: if they catch hold of each other, the angular momentum of each skater adds together so that their total angular momentum stays the same.

In the new study, Lock and Stewart modeled what happens when the “ice skaters” are Earth-sized rocky planets colliding with other large objects with both high energy and high angular momentum.

“We looked at the statistics of giant impacts, and we found that they can form a completely new structure,” Stewart said.

Lock and Stewart found that over a range of high temperatures and high angular momenta, planet-sized bodies could form a new, much larger structure, an indented disk rather like a red blood cell or a donut with the center filled in. The object is mostly vaporized rock, with no solid or liquid surface.

They have dubbed the new object a “synestia,” from “syn-,” “together” and “Estia,” Greek goddess of architecture and structures.

The key to synestia formation is that some of the structure’s material goes into orbit. In a spinning, solid sphere, every point from the core to the surface is rotating at the same rate. But in a giant impact, the material of the planet can become molten or gaseous and expands in volume. If it gets big enough and is moving fast enough, parts of the object pass the velocity needed to keep a satellite in orbit, and that’s when it forms a huge, disc-shaped synestia, according to the new study.

Previous theories had suggested that giant impacts might cause planets to form a disk of solid or molten material surrounding the planet. But for the same mass of planet, a synestia would be much larger than a solid planet with a disk.

Most planets likely experience collisions that could form a synestia at some point during their formation, Stewart said. For an object like Earth, the synestia would not last very long – perhaps a hundred years – before it lost enough heat to condense back into a solid object. But synestia formed from larger or hotter objects such as gas giant planets or stars could potentially last much longer, she said.

The synestia structure also suggests new ways to think about lunar formation. The moon is remarkably like Earth in composition, and most current theories about how the moon formed involve a giant impact that threw material into orbit. But such an impact could have instead formed a synestia from which the Earth and Moon both condensed, Stewart said.

No one has yet observed a synestia directly, but they might be found in other solar systems once astronomers start looking for them alongside rocky planets

Contacts and sources:
Lauren Lipuma
The American Geophysical Union

Citation: “The structure of terrestrial bodies: Impact heating, corotation limits and synestias” http://onlinelibrary.wiley.com/doi/10.1002/2016JE005239/pdf.

Researchers Discover Hottest Lavas That Erupted in Past 2.5 Billion Years

An international team of researchers led by geoscientists with the Virginia Tech College of Science recently discovered that deep portions of Earth's mantle might be as hot as it was more than 2.5 billion years ago.

The study, led by Esteban Gazel, an assistant professor with Virginia Tech's Department of Geosciences, and his doctoral student Jarek Trela of Deer Park, Illinois, is published in the latest issue of Nature Geoscience. The study brings new, unprecedented evidence on the thermal evolution of the deep Earth during the past 2.5 billion years, Gazel said.

This is an artistic interpretation of an Archean komatiite lava flow.

Credit: Professor Claude Herzberg of Rutgers University

The Archean Eon -- covering from 2.5 to 4 billion years ago -- is one of the most enigmatic times in the evolution of our planet, Gazel said. During this time period, the temperature of Earth's mantle -- the silicate region between the crust and the outer core -- was hotter than it is today, owing to a higher amount of radioactive heat produced from the decay of elements such as potassium, thorium, and uranium. Because Earth was hotter during this period, this interval of geologic time is marked by the widespread of occurrence of a unique rock known as komatiite.

"Komatiites are basically superhot versions of Hawaiian style lava flows," Gazel said. "You can imagine a Hawaiian lava flow, only komatiites were so hot that they glowed white instead of red, and they flowed on a planetary surface with very different atmospheric conditions, more similar to Venus than the planet we live on today."

Earth essentially stopped producing abundant hot komatiites after the Archean era because the mantle has cooled during the past 4.5 billion years due to convective cooling and a decrease in radioactive heat production, Gazel said.

However, Gazel and a team made what they call an astonishing discovery while studying the chemistry of ancient Galapagos-related lava flows, preserved today in Central America: a suite of lavas that shows conditions of melting and crystallization similar to the mysterious Archean komatiites.

Gazel and collaborators studied a set of rocks from the 90 million-year-old Tortugal Suite in Costa Rica and found that they had magnesium concentrations as high as Archean komatiites, as well as textural evidence for extremely hot lava flow temperatures.

"Experimental studies tell us that that the magnesium concentration of basalts and komatiites is related to the initial temperature of the melt," Gazel said. "They higher the temperature, the higher the magnesium content of a basalt."

X-ray chemical maps of olivines of the Tortugal Suite that record extremely hot crystallization temperatures. Image taken from research paper spearheaded by Esteban Gazel, an assistant professor in the Department of Geosciences, and doctoral student Jarek Trela.

Credit: Virginia Tech

The team also studied the composition olivine, the first mineral that crystallized from these lavas. Olivine -- a light green mineral that Gazel has obsessively explored many volcanoes and magmatic regions to search for -- is an extremely useful tool to study a number of conditions related to origin of a lava flow because it is the first mineral phase that crystallizes when a mantle melt cools. Olivines also carry inclusions of glass -- that once was melt -- and other smaller minerals that are helpful to decipher the secrets of the deep Earth.

"We used the composition of olivine as another thermometer to corroborate how hot these lavas were when they began to cool," Gazel said. "You can determine the temperature that basaltic lava began crystallizing by analyzing the composition of olivine and inclusions of another mineral called spinel. At higher temperatures, olivine will incorporate more aluminum into its structure and spinel will incorporate more chromium. If you know how much of these elements are present in each mineral, then you know the temperature at which they crystallized."

The team found that Tortugal olivines crystallized at temperature nearing 2,900 degrees Fahrenheit (1,600 degrees Celsius) -- as high as temperatures recorded by olivines from komatiites -- making this a new record on lava temperatures in the past 2.5 billion years.

Gazel and collaborators suggest in their study that Earth may still be capable of producing komatiite-like melts. Their results suggest that Tortugal lavas most likely originated from the hot core of the Galapagos mantle plume that started producing melts nearly 90 million years ago and has remained active ever since.

A mantle plume is a deep-earth structure that likely originates at the core-mantle boundary of the planet. When it nears the surface of the planet it begins to melt, forming features known as hotspots such as those found in Hawaii or Galapagos. Geologists can then study these hotspot lava flows and use their geochemical information as a window into the deep Earth.

"What is really fascinating about this study is that we show that the planet is still capable of producing lavas as hot as during Archean time period," Gazel said. "Based on our results from Tortugal lavas, we think that mantle plumes are 'tapping' a deep, hot region of the mantle that hasn't cooled very much since the Archean. We think that this region is probably being sustained by heat from the crystallizing core of the planet."

"This is a really interesting discovery and we are going to keep investigating Tortugal," said Trela, a doctoral student and the first author of the paper. "Although the Tortugal Suite was first discovered and documented more than 20 years ago, it wasn't until now that we have the technology and experimental support to better understand the global implications of this location."

Trela added, "Our new data suggest that this suite of rocks offers tremendous opportunity to answer key questions regarding the accretion of the Earth, its thermal evolution, and the geochemical messages that mantle plumes bring to the surface of the planet."

The international team also included fellow Virginia Tech doctoral student Lowell Moore of Staunton, Virginia; Alexander Sobolev and Valentina Batanova of the ISTerre: Institut des Sciences de la Terre, France, and the Vernadsky Institute of Geochemistry of the Russian Academy of Sciences, Michael Bizimis of the University of South Carolina, and Brian Jicha of the University of Wisconsin-Madison.

Contacts and sources:
Steven Mackay
Virginia Tech

7.2-Million-Year-Old Pre-Human Remains Discovered In The Balkans

The common lineage of great apes and humans split several hundred thousand earlier than hitherto assumed, according to an international research team headed by Professor Madelaine Böhme from the Senckenberg Centre for Human Evolution and Palaeoenvironment at the University of Tübingen and Professor Nikolai Spassov from the Bulgarian Academy of Sciences. 

The researchers investigated two fossils of Graecopithecus freybergi with state-of-the-art methods and came to the conclusion that they belong to pre-humans. Their findings, published today in two papers in the journal PLOS ONE, further indicate that the split of the human lineage occurred in the Eastern Mediterranean and not - as customarily assumed - in Africa.

This is a 7.24 million year old upper premolar of Graecopithecus from Azmaka, Bulgaria.
Photo: Wolfgang Gerber, University of Tübingen

Present-day chimpanzees are humans' nearest living relatives. Where the last chimp-human common ancestor lived is a central and highly debated issue in palaeoanthropology. Researchers have assumed up to now that the lineages diverged five to seven million years ago and that the first pre-humans developed in Africa. 

According to the 1994 theory of French palaeoanthropologist Yves Coppens, climate change in Eastern Africa could have played a crucial role. The two studies of the research team from Germany, Bulgaria, Greece, Canada, France and Australia now outline a new scenario for the beginning of human history.

Dental roots give new evidence

The team analyzed the two known specimens of the fossil hominid Graecopithecus freybergi: a lower jaw from Greece and an upper premolar from Bulgaria. Using computer tomography, they visualized the internal structures of the fossils and demonstrated that the roots of premolars are widely fused.

This is the lower jaw of the 7.175 million year old Graecopithecus freybergi (El Graeco) from Pyrgos Vassilissis, Greece (today in metropolitan Athens).
Photo: Wolfgang Gerber, University of Tübingen

"While great apes typically have two or three separate and diverging roots, the roots of Graecopithecus converge and are partially fused - a feature that is characteristic of modern humans, early humans and several pre-humans including Ardipithecus and Australopithecus", said Böhme.

The lower jaw, nicknamed 'El Graeco' by the scientists, has additional dental root features, suggesting that the species Graecopithecus freybergi might belong to the pre-human lineage. "We were surprised by our results, as pre-humans were previously known only from sub-Saharan Africa," said Jochen Fuss, a Tübingen PhD student who conducted this part of the study.

Furthermore, Graecopithecus is several hundred thousand years older than the oldest potential pre-human from Africa, the six to seven million year old Sahelanthropus from Chad. The research team dated the sedimentary sequence of the Graecopithecus fossil sites in Greece and Bulgaria with physical methods and got a nearly synchronous age for both fossils - 7.24 and 7.175 million years before present. "It is at the beginning of the Messinian, an age that ends with the complete desiccation of the Mediterranean Sea," Böhme said.

Professor David Begun, a University of Toronto paleoanthropologist and co-author of this study, added, "This dating allows us to move the human-chimpanzee split into the Mediterranean area."

Environmental changes as the driving force for divergence

As with the out-of-East-Africa theory, the evolution of pre-humans may have been driven by dramatic environmental changes. The team led by Böhme demonstrated that the North African Sahara desert originated more than seven million years ago. The team concluded this based on geological analyses of the sediments in which the two fossils were found. Although geographically distant from the Sahara, the red-colored silts are very fine-grained and could be classified as desert dust. An analysis of uranium, thorium, and lead isotopes in individual dust particles yields an age between 0.6 and 3 billion years and infers an origin in Northern Africa.

Moreover, the dusty sediment has a high content of different salts. "These data document for the first time a spreading Sahara 7.2 million years ago, whose desert storms transported red, salty dusts to the north coast of the Mediterranean Sea in its then form," the Tübingen researchers said. This process is also observable today.

This is an electron microscope image of a dust particle rounded by eolian transport. It originated in the Sahara desert and was found in 7.2 million year old sediments in Greece.
Photo: Ulf Linnemann, Senckenberg Center for Human Evolution and Palaeoenvironment, University of Tübingen

However, the researchers' modelling shows that, with up to 250 grams per square meter and year, the amount of dust in the past considerably exceeds recent dust loadings in Southern Europe more than tenfold, comparable to the situation in the present-day Sahel zone in Africa.

Fire, grass, and water stress

The researchers further showed that, contemporary to the development of the Sahara in North Africa, a savannah biome formed in Europe. Using a combination of new methodologies, they studied microscopic fragments of charcoal and plant silicate particles, called phytoliths. Many of the phytoliths identified derive from grasses and particularly from those that use the metabolic pathway of C4-photosynthesis, which is common in today's tropical grasslands and savannahs. The global spread of C4-grasses began eight million years ago on the Indian subcontinent - their presence in Europe was previously unknown.

"The phytolith record provides evidence of severe droughts, and the charcoal analysis indicates recurring vegetation fires," said Böhme. "In summary, we reconstruct a savannah, which fits with the giraffes, gazelles, antelopes, and rhinoceroses that were found together with Graecopithecus," Spassov added

"The incipient formation of a desert in North Africa more than seven million years ago and the spread of savannahs in Southern Europe may have played a central role in the splitting of the human and chimpanzee lineages," said Böhme. She calls this hypothesis the North Side Story, recalling the thesis of Yves Coppens, known as East Side Story.

The findings are described in two studies pubished in PLOS ONE titled "Potential hominin affinities of Graecopithecus from the late Miocene of Europe" and "Messinian age and savannah environment of the possible hominin Graecopithecus from Europe."

Professor Madelaine Böhme
Senckenberg Center for Human Evolution and Palaeoenvironment (HEP Tuebingen)
University of Tübingen

Professor Nikolai Spassov
National Museum of Natural History, Sofia
Bulgarian Academy of Sciences

Professor David Begun
Department of Anthropology
University of Toronto, Canada

 The papers will appear online:

Potential hominin affinities of Graecopithecus from the Late Miocene of Europe) at http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0177127 a

 Messinian age and savannah environment of the possible hominin Graecopithecus from Europe. http://journals.plos.org/plosone/article?id=10.1371/journal.pone.0177347

Sunday, May 21, 2017

Newly Discovered Supernova Bright Enough To Be Seen from Earth

On May 13, 2017, Patrick Wiggins, public outreach educator for the University of Utah’s Department of Physics & Astronomy, and NASA solar system ambassador to Utah, spotted something unusual in the sky. He was looking at the spiral galaxy NGC 6946, known as the Fireworks Galaxy, in the Cygnus constellation over 22 million light-years away from his telescope at his home near Erda, Utah. He noticed a bright spot that he hadn’t seen before. By comparing what he was seeing with earlier photographs taken of the same galaxy, he realized he was witnessing a star explode. He had just discovered a supernova.

Credit: Patrick Dunford

Confirmed supernova, “SN 2017aew can be seen on the top right side of the Fireworks Galaxy in the center of this animation.Download Full-Res Image

Named SN 2017eaw, Wiggins’ discovery was confirmed on May 14th by two experts in supernovae; Subo Dong at Peking University, and Krzysztof Z. Stanek from Ohio State University.

When a star goes supernova, it is one of the largest, most impressive astronomical events in space. A supernova occurs when a massive star collapses in a brilliant explosion that can outshine entire galaxies. This can happen in two ways; when a smaller star burns through its nuclear fuel, the core loses the energy to push against the gravity relentlessly pulling the star inward. 

If the weakened star gains mass from a star orbiting nearby, the core will collapse due to the overwhelming gravitational force in an event called a Type I Supernova. When a massive star many times larger than our own sun runs out of nuclear fuel, the star’s core collapses from its own staggering gravitational forces and explodes in a Type II Supernova. 

In both cases, these supernovae are astoundingly bright for a time — bright enough to be seen by amateur and professional astronomers alike — until they expend their energy and the light begins to fade over the next few months.

SN 2017eaw has been confirmed to be a Type II supernova. This is the third supernova discovery for Wiggins. In 2015, he discovered SN 2015Q in the NGC 3888 galaxy in Ursa Major, and in 2014 he independently discovered supernova SN 2014G, along with Koichi Itagaki in Japan.

Confirmed supernova, “SN 2017aew”, can be seen on the top right side of the “Fireworks Galaxy” in the center of this animation.

Credit: : Patrick Wiggins

In addition, Wiggins has discovered a whole host of astronomical events in space, including an asteroid in 2008, which the International Astronomical Union named Univofutah, at Wiggins’ request, to honor the University of Utah. Wiggins’ work has earned him many accolades, including the prestigious Distinguished Public Service Medal, NASA’s highest civilian honor. You can meet Wiggins and the rest of the Phun with Physics scientists during free days at the Natural History Museum of Utah.

Contacts and sources:
Patrick Wiggins
University of Utah

Nearly Half Of California’s Native Salmon, Steelhead Aand Trout On Track To Be Extinct Within 50 Years

The University of California, Davis, and nonprofit California Trout provided key results from an in-depth report today detailing the status of 32 types of salmon, steelhead, and trout that are native to California. State of the Salmonids II: Fish in Hot Water offers concerning data about the declining health of these fish populations and opportunities for stabilizing and even recovering many species.

The report found that if present trends continue, 74 percent of California’s native salmon, steelhead, and trout species are likely to be extinct in 100 years, and 45 percent could be extinct in 50 years.

Chinook salmon in California.
UC Davis salmon jump
Credit: Ed Homich

Alarm bell and road map

“This report should rightly be considered an alarm bell, but it should also be seen as a roadmap for how we can correct course to better support native aquatic species,” said lead report author Peter Moyle, distinguished professor emeritus in the Department of Wildlife, Fish and Conservation Biology and Associate Director of the UC Davis Center for Watershed Sciences. “Thanks to ongoing scientific research, we now know what to do — and where — to improve the plight of native fish.”

SOS II: Fish in Hot Water is the second such report released by CalTrout and the UC Davis Center for Watershed Sciences. The first edition was published in 2008 and established a baseline level of health for each of 32 types of native salmon, steelhead and trout populations in the state, including the extinct bull trout. Since that time, the number of California’s native fish species likely to be extinct within the next five decades nearly tripled, from five to 14 species. And after five years of historic drought, 81 percent of the remaining 31 species are worse off today than they were a decade ago.

“The health of our native fish is a reflection of the health of our rivers and streams,” said Curtis Knight, executive director of CalTrout. “Declining fish populations indicate degraded waters, which threaten the health and economic well-being of all Californians.”
Key threats to survival of species

The report includes an analysis of key threats to the survival of each species, starting with the overarching threat of climate change, which is likely to reduce the availability of cold water habitat that salmon, steelhead and trout all depend on for survival. It also highlights various other human-induced threats, such as dams, agriculture, estuary alteration, urbanization and transportation.

“We have already lost one of our native fish,” Knight added. “The bull trout was last seen in the McCloud River in 1975. The fact we haven’t lost another since 1975 is remarkable. These fish are resilient, but this report underscores that we must act now to prevent further extinctions.”

The report notes that improving salmonid status throughout California requires investing in productive habitats that promote growth, survival and diversity. 

CalTrout notes it has developed an action plan to return the state’s salmon, steelhead and trout to resilience to help many of these species thrive.Credit: Phil Reedy

Reversing the trend toward extinction

To reverse the trend toward extinction, the report suggests prioritizing protection and restoration efforts in three general areas:

Protecting the most productive river ecosystems remaining in California, such as the Smith and Eel rivers. These strongholds, among others, have the capacity to support diversity and abundance because they retain high-quality habitat and are not heavily influenced by hatcheries, supporting the persistence of wild fish.

Increasing focus on source waters will keep more water in streams and reduce stress on fish during drought, buffering the effects of climate change. Sierra meadow restoration, springs protection and progressive groundwater 
management all contribute to this effort.

Restoring function to once productive — but now highly altered — habitats can greatly improve rearing conditions for juvenile fish, especially floodplains, coastal lagoons, estuaries and spring-fed rivers.

Additionally, the report identifies three science-based strategies to support a return to abundance for California’s native salmonids:

First, focus on opportunities to mimic natural processes within altered landscapes. For example, off-season farmland can mimic traditional floodplains and support rapid growth of juvenile salmon.

Second, prioritize improving fish passage to historical spawning and rearing grounds that have been cut off over time.

And pursue strategies that increase genetic diversity of wild fish.

“We know we are not going to turn back the clock to a time before rivers were dammed or otherwise altered for human benefit,” Knight said. “Using the best available science, we can make landscape-level changes that will allow both people and fish to thrive in California.”

California’s native salmonids facing the most immediate threat include:

Central California coast coho salmon

Sacramento River winter-run chinook salmon

Southern steelhead

Kern River rainbow trout

McCloud River redband trout

A longer, more detailed report from UC Davis Center for Watershed Sciences is expected this summer.

Contacts and sources:
Nina Erlich-Williams
University of California, Davis

Strong Social Ties Help Animals Live Longer

Large families and strong social ties help animals live longer, new research suggests.

In a huge study of female rhesus macaques, a scientist from the University of Exeter found those with many close female relatives have better life expectancy. However, the effect fades with age – suggesting older females learn how to “navigate the social landscape” and have less need for social ties.

“Our study supports the idea that social ties promote survival,” said Dr Lauren Brent, of the University of Exeter. “This adds to a small but growing body of research that helps to explain why animals are social.”

Rhesus Macaques feeding; in Khao No-Khao Kaeo, Nakhon Sawan, Thailand
File:Rhesus Macaques feeding.jpg
Credit: Wikimedia Commons

The researchers used female relatives as a proxy for social ties, and they found that each extra female relative reduced a prime-aged female macaque’s chances of dying in one year by 2.3%.

Dr Brent added: “What was particularly interesting was that social ties didn’t have survival benefits for older females. One possible explanation for this is that older females behave differently from their younger counterparts.

“Macaques spend a lot of time interacting with one another. Being groomed helps rid them of parasites, while being aggressive helps establish their place in the social order. Each macaque would like to get a lot of grooming and give a lot of aggression, without spending much energy grooming others and without being the target of aggression.”

The study found that older females manage this – behaving aggressively and spending a lot of time being groomed by others without offering much grooming in return or being the target of aggression themselves.

“Older females were still involved in society but seemed better able pick and choose their involvement. The experience and social skills females gain with age could mean they no longer need to rely on help from their friends to get by.”

The researchers used a large dataset spanning 21 years and including 910 adult female rhesus macaques in Puerto Rico.

Dr Brent said such research could be “hugely important in understanding humans”.

“Just like these monkeys, we spend a lot of time navigating the social world,” she said. “Humans and macaques last shared a common ancestor about 25 million years ago, and we can take clues from these distant cousins about how humans might have existed in pre-industrial societies.

“Human societies are hugely complex, and factors such as culture and access to healthcare make it hard to study the impact of a single factor like social relationships on survival.”

The research, carried out in collaboration with the University of Pennsylvania and the University of Puerto Rico, is published in the journal Proceedings of the Royal Society B.

The paper is entitled: “Family network size and survival across the lifespan of female macaques.”

Contacts and sources:
Dr Lauren Brent
University of Exeter

Workout Suit: Ventilating Flaps Lined With Live Cells Open and Close In Response to an Athlete’s Sweat.

A team of MIT researchers has designed a breathable workout suit with ventilating flaps that open and close in response to an athlete’s body heat and sweat. These flaps, which range from thumbnail- to finger-sized, are lined with live microbial cells that shrink and expand in response to changes in humidity. The cells act as tiny sensors and actuators, driving the flaps to open when an athlete works up a sweat, and pulling them closed when the body has cooled off.

The researchers have also fashioned a running shoe with an inner layer of similar cell-lined flaps to air out and wick away moisture. Details of both designs are published today in Science Advances.

Why use live cells in responsive fabrics? The researchers say that moisture-sensitive cells require no additional elements to sense and respond to humidity. The microbial cells they have used are also proven to be safe to touch and even consume. What’s more, with new genetic engineering tools available today, cells can be prepared quickly and in vast quantities, to express multiple functionalities in addition to moisture response.

This breathable workout suit prototype has ventilating flaps that open and close in response to an athlete’s body heat and sweat. The left photo was taken before exercise when ventilation flaps are flat; after exercise, the ventilation flaps have curved.
This breathable workout suit prototype has ventilating flaps that open and close in response to an athlete’s body heat and sweat. The left photo was taken before exercise when ventilation flaps are flat; after exercise, the ventilation flaps have curved.
Image: Hannah Cohen

To demonstrate this last point, the researchers engineered moisture-sensitive cells to not only pull flaps open but also light up in response to humid conditions.

“We can combine our cells with genetic tools to introduce other functionalities into these living cells,” says Wen Wang, the paper’s lead author and a former research scientist in MIT’s Media Lab and Department of Chemical Engineering. “We use fluorescence as an example, and this can let people know you are running in the dark. In the future we can combine odor-releasing functionalities through genetic engineering. So maybe after going to the gym, the shirt can release a nice-smelling odor.”

Wang’s co-authors include 14 researchers from MIT, specializing in fields including mechanical engineering, chemical engineering, architecture, biological engineering, and fashion design, as well as researchers from New Balance Athletics. Wang co-led the project, dubbed bioLogic, with former graduate student Lining Yao as part of MIT’s Tangible Media group, led by Hiroshi Ishii, the Jerome B. Wiesner Professor of Media Arts and Sciences.

Shape-shifting cells

In nature, biologists have observed that living things and their components, from pine cone scales to microbial cells and even specific proteins, can change their structures or volumes when there is a change in humidity. The MIT team hypothesized that natural shape-shifters such as yeast, bacteria, and other microbial cells might be used as building blocks to construct moisture-responsive fabrics.

“These cells are so strong that they can induce bending of the substrate they are coated on,” Wang says.

The researchers first worked with the most common nonpathogenic strain of E. coli, which was found to swell and shrink in response to changing humidity. They further engineered the cells to express green fluorescent protein, enabling the cell to glow when it senses humid conditions.

They then used a cell-printing method they had previously developed to print E. coli onto sheets of rough, natural latex.

The team printed parallel lines of E. coli cells onto sheets of latex, creating two-layer structures, and exposed the fabric to changing moisture conditions. When the fabric was placed on a hot plate to dry, the cells began to shrink, causing the overlying latex layer to curl up. When the fabric was then exposed to steam, the cells began to glow and expand, causing the latex flatten out. After undergoing 100 such dry/wet cycles, Wang says the fabric experienced “no dramatic degradation” in either its cell layer or its overall performance.

No sweat

The researchers worked the biofabric into a wearable garment, designing a running suit with cell-lined latex flaps patterned across the suit’s back. They tailored the size of each flap, as well as the degree to which they open, based on previously published maps of where the body produces heat and sweat.

“People may think heat and sweat are the same, but in fact, some areas like the lower spine produce lots of sweat but not much heat,” Yao says. “We redesigned the garment using a fusion of heat and sweat maps to, for example, make flaps bigger where the body generates more heat.”

Support frames underneath each flap keep the fabric’s inner cell layer from directly touching the skin, while at the same time, the cells are able to sense and react to humidity changes in the air lying just over the skin. In trials to test the running suit, study participants donned the garment and worked out on exercise treadmills and bicycles while researchers monitored their temperature and humidity using small sensors positioned across their backs.

After five minutes of exercise, the suit’s flaps started opening up, right around the time when participants reported feeling warm and sweaty. According to sensor readings, the flaps effectively removed sweat from the body and lowered skin temperature, more so than when participants wore a similar running suit with nonfunctional flaps.

When Wang tried on the suit herself, she found that the flaps created a welcome sensation. After pedaling hard for a few minutes, Wang recalls that “it felt like I was wearing an air conditioner on my back.”

Ventilated running shoes

The team also integrated the moisture-responsive fabric into a rough prototype of a running shoe. Where the bottom of the foot touches the sole of the shoe, the researchers sewed multiple flaps, curved downward, with the cell-lined layer facing toward — though not touching — a runner’s foot. They again designed the size and position of the flaps based on heat and sweat maps of the foot.

“In the beginning, we thought of making the flaps on top of the shoe, but we found people don’t normally sweat on top of their feet,” Wang says. “But they sweat a lot on the bottom of their feet, which can lead to diseases like warts. So we thought, is it possible to keep your feet dry and avoid those diseases?”

As with the workout suit, the flaps on the running shoe opened and lit up when researchers increased the surrounding humidity; in dry conditions the flaps faded and closed.

Going forward, the team is looking to collaborate with sportswear companies to commercialize their designs, and is also exploring other uses, including moisture-responsive curtains, lampshades, and bedsheets.

“We are also interested in rethinking packaging,” Wang says. “The concept of a second skin would suggest a new genre for responsive packaging.”

“This work is an example of harnessing the power of biology to design new materials and devices and achieve new functions,” says Xuanhe Zhao, the Robert N. Noyce Career Development Associate Professor in the Department of Mechanical Engineering and a co-author on the paper. “We believe this new field of ‘living’ materials and devices will find important applications at the interface between engineering and biological systems.”

This research was supported, in part, by MIT Media Lab and the Singapore-MIT Alliance for Research and Technology.

Contacts and sources:
Jennifer Chu
Massachusetts Institute of Technology

Astronomers Create the Largest Map of the Universe Yet

Astronomers of the extended Baryonic Oscillation Spectroscopic Survey, led by EPFL Professor Jean-Paul Kneib, used the Sloan telescope to create the first map of the Universe based entirely on quasars.

Quasars are incredibly bright and distant points of light powered by supermassive black holes. As matter and energy fall into the black hole, they heat up to incredible temperatures and begin to glow with excessive brightness. By observing this cosmic glow, the scientists of the multi-institutional Sloan Digital Sky Survey (SDSS), which includes EPFL, have constructed the largest map of the distant Universe to-date. 

A slice through largest-ever three-dimensional map of the Universe. Earth is at the left, and distances to galaxies and quasars are labelled by the lookback time to the objects (lookback time means how long the light from an object has been traveling to reach us here on Earth). The locations of quasars (galaxies with supermassive black holes) are shown by the red dots, and nearer galaxies mapped by SDSS are also shown (yellow).
The right-hand edge of the map is the limit of the observable Universe, from which we see the Cosmic Microwave Background (CMB) – the light “left over” from the Big Bang. The bulk of the empty space in between the quasars and the edge of the observable universe are from the “dark ages”, prior to the formation of most stars, galaxies, or quasars. Click on the image for a larger version.
Credit:  Anand Raichoor (École polytechnique fédérale de Lausanne, Switzerland) and the SDSS collaboration

As eBOSS continues to survey the sky over the next 3 years, the blank regions will be filled in with more galaxies and quasars.

The work will be published in the Monthly Notices of the Royal Astronomical Society (link to preprint).

Quasars are supermassive black holes at the centers of galaxies and they radiate huge amounts of electromagnetic energy. “Because quasars are so bright, we can see them all the way across the Universe,” says study co-leader Ashley Ross (Ohio State University). “That makes them the ideal objects to use to make the biggest map yet.”

“These quasars are so far away that their light left them when the Universe was between 3 and 7 billion years old, long before the Earth even existed,” adds Gongbo Zhao from the National Astronomical Observatory of China, the study’s other co-leader.

To construct the map, the scientists used the SDSS telescopes at New Mexico to measure accurate 3D positions for an unprecedented sample of over 147,000 quasars. This work took place during the first two years of the Extended Baryon Oscillation Spectroscopic Survey (eBOSS), one of the component research projects of SDSS led by Jean-Paul Kneib, Professor of Astrophysics at EPFL. The SDSS telescope observations gave the astronomers the quasars’ distances, which they then used to pinpoint the quasars’ positions in a 3D map.

But the scientists didn’t stop there; they wanted to use to understand the expansion history of the Universe. For this they went a step further and used a clever technique that involves “baryon acoustic oscillations” (BAOs). These are the present-day imprint of sound waves that travelled through the early Universe, when it was much hotter and denser than it is now. But when the Universe was 380,000 years old, conditions changed suddenly and the sound waves became “frozen” in place, imprinted in the 3D structure of the Universe we see today.

One of the SDSS telescopes at Apache Point Observatory in New Mexico (USA) 

Credit; ©SDSS

The process that produced these frozen BAOs is simple, which means that scientists can have a very good idea of what BAOs must have looked like in the early Universe. So when we look at the 3D structure of the Universe today, it contains these ancient BAOs, but massively stretched out by the expansion of the universe.

The astronomers used the observed size of a BAO as “standard ruler” to measure distances in their 3D map, the way we can estimate the length of a football field by measuring the apparent angle of a meter rule on one side. “You have meters for small units of length, kilometres or miles for distances between cities, and we have the BAO scale for distances between galaxies and quasars in cosmology,” says Pauline Zarrouk, a PhD student at Irfu/CEA (University Paris-Saclay) who measured the projected BAO scale.

Working backwards in time, the SDSS astronomers covered a range of time periods never observed before. The study measured the conditions when the Universe was just 3 to 7 billion years old, more than 2 billion years before the Earth formed.

“The results of our study confirm the Standard Model of cosmology, where the Universe follows the predictions of Einstein’s General Theory of Relativity but includes the yet unknown components of “dark matter”, and the mysterious ‘dark energy’, which is needed to explain the accelerated expansion of the Universe,” says Jean-Paul Kneib.

The eBOSS experiment continues with the SDSS telescope. As the eBOSS astronomers observe more quasars and nearby galaxies, the size of their 3D map will keep growing. And after eBOSS is complete, a new generation of sky surveys will begin, including the Dark Energy Spectroscopic Instrument (DESI) and the European Space Agency Euclid satellite mission, two projects in which EPFL is also partner. These will increase the fidelity of the maps by a factor of ten compared with eBOSS, revealing the Universe and dark energy in unprecedented detail.

Contacts and sources:
École polytechnique fédérale de Lausanne, Switzerland

Warfare May Explain Differences in Social Structures in Chimpanzees and Bonobos

Researchers found that chimpanzees associate more with partners of the same sex while bonobos of either sex associate preferentially with females

Researchers of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany, compared data collected from several wild communities of our closest living relatives, chimpanzees and bonobos, which show that chimpanzees associate more with partners of the same sex while bonobos of either sex associate preferentially with females. This result can be explained by different needs for cooperation. 

While male chimpanzees cooperate with each other during strong between-group competition, comparable to human warfare, which is absent in bonobos, bonobo males mainly rely on the help of females, especially their mothers, in conflicts with other males within their community. Females of both species, however, cooperate with other females in raising offspring.

Bonobos during a grooming session.
Credit; © Zanna Clay (LuiKotale Bonobo Research Project)

Group-living has its benefits, such as the joint defense against predators and better access to food and mates; as well as costs, like an increased competition over food and mates or a higher risk of getting a disease from a group mate. To increase the benefits of group-living, animals often associate selectively with certain partners and their choice is likely driven by their cooperative needs.

While bonobos and chimpanzees are similar in many ways, as both species are closely related to each other genetically, they differ in some important behavioral aspects. “While chimpanzee males are highly territorial, with hostile and sometimes lethal intergroup encounters, bonobos have rather peaceful relationships between groups and lack lethal violence during encounters”, says Martin Surbeck of the Max Planck Institute for Evolutionary Anthropology in Leipzig, Germany. 

The researchers wanted to know whether these differences in male cooperation against outsiders, also influence their choice of associates.
Analysis of data from field studies

Chimpanzees during a grooming session.

Credit: © Roman Wittig (Taï Chimpanzee Project)

Surbeck and his team have thus compared long-term data from five chimpanzee and two bonobo communities from five different field sites in Ivory Coast, Uganda and the Democratic Republic of Congo to study with whom bonobos and chimpanzees preferentially associate. “All chimpanzee communities were sexually segregated, meaning that males and females associated more with same sex partners”, says Surbeck. “In bonobos, males did not prefer to associate with other males and both sexes associated preferentially with females.”

These results can be explained by different forms of cooperation in bonobos and chimpanzees. While chimpanzee males need to cooperate with other males when it comes to activities like border patrolling, territory defense and joint hunting, bonobo males who are much less territorial associate mainly with females, most often their mothers, with whom they cooperate and who help to increase their sons’ mating success. 

The females of both species cooperate with each other when it comes to raising their young. Surbeck summarizes: “Our obtained results show how warfare may have a fundamental impact on the structure of a given society.”

Contacts and sources:
Dr. Martin Surbeck
Dept. of Primatology
Max Planck Institute for Evolutionary Anthropology, Leipzig

Citation: Sex-specific association patterns in bonobos and chimpanzees reflect species differences in cooperation.
Royal Society Open Science; 3 May, 2017 (DOI: 10.1098/rsos.161081)

Populations Along the Eastern Mediterranean Coast Share a Genetic Heritage That Transcends Nationality

The Mediterranean Sea has represented one of the most important crossroads in human history, acting both as a barrier and a bridge between three continents and multiple human groups characterized by different genetic and cultural backgrounds. 

Despite this complex history and despite modern national borders, there is a shared Mediterranean genetic continuity, extending from Sicily to Cyprus, where the populations of certain Greek-speaking islands appear genetically closer to Southern Italian populations than to populations from continental Greece. 

This is a central finding of a new study published in Scientific Reports, co-authored by Chiara Barbieri, researcher from the Max Planck Institute for the Science of Human History in Jena, coordinated by the Human Biodiversity and Population Genomics group at the Department of Biological, Geological and Environmental Sciences (BiGeA) of the University of Bologna, and funded by the National Geographic Society.

Map of the sampling locations included in the study, with presence of Albanian, Greek or Italian languages.

 Credit: Sarno et al. DOI: 10.1038/s41598-017-01802-4

The study describes the genetic fingerprints of the Mediterranean people with high-density genomic markers and a wide sample of modern populations from Sicily and Southern Italy. Their genetic profiles were analyzed to reconstruct the combination of ancestry components and the demographic history of the region. As one would expect, populations inhabiting the southeastern shores of Europe are the result of a complex, multi-layered history. 

One of these layers corresponds to a shared genetic background, extending from Sicily to Cyprus and involving Crete, the Aegean islands and Anatolia. “This shared Mediterranean ancestry possibly traces back to prehistoric times, as the result of multiple migration waves, with peaks during the Neolithic and the Bronze Age,” says Stefania Sarno, researcher from the University of Bologna and lead author of the study. 

Apparently, the ancient Greek expansions (during the Magna Graecia foundation) were only one of the last events in a long history of East-West movements, where the Mediterranean Sea served as a preferential crossroads for the circulation of genes and cultures.

A new perspective for the diffusion of indo-european languages

One of the most intriguing layers hidden in the Mediterranean genetic landscape involves an important Bronze Age contribution from a Caucasus (or Caucasus-like) source, accompanied by the virtual absence of the typical “Pontic-Caspian” genetic component from the Asian steppe. 

The latter is a very characteristic genetic signal well represented in North-Central and Eastern Europe, which previous studies associated with the introduction of Indo-European languages to the continent. “These new genomic results from the Mediterranean open a new chapter for the study of the prehistoric movements behind the diffusion of the most represented language family in Europe. 

The spread of these languages in the Southern regions, where Indo-European languages like Italian, Greek and Albanian are spoken nowadays, cannot be explained with the major contribution from the steppe alone,” adds Barbieri.

The origin of the Indo-European coincides with the Anatolian hypothesis according to quantitative lexical reconstructions

Bouckaert et al. DOI: 10.1126/science.342.6165.1446-a Science

The timing and geographical origin of the Indo-European language family was at the core of a heated debate between linguists, archaeologists and historians. Two major alternative theories have been proposed: the Anatolian hypothesis would place the origin of the Indo-European languages in Neolithic Anatolia, at least 8,000 years ago, while the steppe hypothesis would place it in the Pontic Steppe in a more recent time, during the Bronze Age around 6,000 years ago. 

Researchers at the Max Planck Institute for the Science of Human History in Jena are focusing on this crucial debate, trying to reconcile apparently contradictory results. A first line of evidence comes from linguistic analysis based on quantitative lexical data, which returned a tree compatible with the Anatolian hypothesis

A second line of evidence comes from genetics, which also contributed to the picture with the reconstruction of population migrations and gene-flow. Analysis based on a vast dataset of ancient DNA revealed an important demographic movement perfectly in line with the steppe hypothesis. The new genetic results from southern Europe challenge a strict steppe model, and add a new perspective into these complex historical reconstructions.

Linguistic and cultural isolates in Southern Italy

The statues of the Bronzi di Riace (Riace's warriors) from the 5th century BC, found in the province of Reggio Calabria, became one of the symbols of the Greek presence in Southern Italy. (Museo nazionale della Magna Grecia, Reggio Calabria).
By Effems (Own work) [CC BY-SA 4.0 via Wikimedia  

The current genetic study also focuses on more recent historical layers that contributed to the present-day genetic makeup of the populations sampled, in particular in the cases of long-standing, non-Italian-speaking communities in Italy. For example, mainland Greece and Albania seem to have acquired additional genetic contributions during historic times, most likely related to the Slavic migrations in the Balkans. 

This recent Balkan genetic ancestry is still evident in some ethno-linguistic minorities of Sicily and Southern Italy, such as the Albanian-speaking Arbereshe. The Arbreshe migrated from Albania to Italy at the end of the Middle Ages and experienced geographic and cultural isolation, which played a part in their distinctive genetic composition. A different case study is that of Greek-speaking communities from Southern Italy. The genetic features of these groups are compatible with the antiquity of their settlement and with a high cultural permeability with neighboring populations, combined with drift and effects of geographic isolation, as in the case of Calabrian Greeks. 

“The study of linguistic and cultural isolates in Italy proved to be important to understand our history and our demography,” says Alessio Boattini, geneticist and anthropologist from the University of Bologna. “The cases of the Albanian- and Greek-speaking communities of Southern Italy help to shed light into the formation of these cultural and linguistic identities.”

“Overall, the study illustrates how both genetic and cultural viewpoints can inform our knowledge of the complex dynamics behind the formation of our Mediterranean heritage, especially in contexts of extensive – both geographically and temporally – admixture,” says Davide Pettener, professor of Anthropology from the University of Bologna. “These results,” adds Prof. Donata Luiselli, who co-led the project, “will be further developed in future studies integrating data from other disciplines, in particular linguistics, archeology and palaeogenomics, with the study of ancient DNA from archaeological remains.”

Contacts and sources:
Dr. Chiara Barbieri
Max Planck Institute for the Science of Human History

Dose of Blue Light Significantly Helps Athletes Compete in Late Evening

Athletes often have to compete late in the evening, when they are no longer able to perform at their best. As reported in the journal Frontiers in Physiology, however, researchers from the University of Basel have shown that athletes who are exposed to blue light before competing can significantly increase their performance in the final spurt. The blue light had no impact on the athletes’ maximum performance.

Many sports events take place late in the evening, during television prime time. At this time of day, however, many athletes often fail to perform at their best due to their sleep-wake cycle.

Athletes in blue light: performance during the final spurt is clearly increased by light exposure. 
Athletes in blue light: performance during the final spurt is clearly increased by light exposure. (Image: University of Basel, Department of Sport, Exercise and Health)
Image: University of Basel, Department of Sport, Exercise and Health

In a study headed by Professor Arno Schmidt-Trucksäss, Raphael Knaier and colleagues at the University of Basel investigated whether light exposure before a cycling time trial can compensate for this disadvantage. The Sports and Exercise Medicine division, as well as Professor Christian Cajochen at the Centre for Chronobiology, took part in this extensive investigation involving 74 young male athletes.

It is well known that blue light reduces the production of the sleep hormone melatonin. The researchers tested the hypothesis that this suppression of melatonin could improve an athlete’s endurance during a 12-minute cycling time trial. They randomly divided the participants into three groups and exposed them to either bright light, blue monochromatic light or control light for an hour. This light exposure was immediately followed by the performance test on the bicycle ergometer.

Bright light is less effective

Exposure to blue light significantly improved the athletes’ ability to increase their performance during the final spurt of the time trial. This increase was defined as the ratio of the performance measured in the first minute to that of the last minute of the test. The subjects’ improved performance in the final spurt also correlated with the amount of blue light. This light was able to effectively suppress the melatonin and thus influence the athletes’ sleep-wake cycle.

Compared to the control light, bright light led to a small increase in overall performance, but the difference was not significant. “Since even minor differences are relevant in top-level sport, however, this should be investigated more closely in further studies,” commented Professor Schmidt-Trucksäss.

Contacts and sources:
Professor Arno Schmidt-Trucksäss
University of Basel

Citation: Raphael Knaier, Juliane Schäfer, Anja Rossmeissl, Christopher Klenk, Henner Hanssen, Christoph Höchsmann, Christian Cajochen, and Arno Schmidt-Trucksäss
Prime Time Light Exposures Do Not Seem to Improve Maximal Physical Performance in Male Elite Athletes, but Enhance End-Spurt Performance
Frontiers in Physiology (2017), doi: 10.3389/fphys.2017.00264