How the immune system 'thinks'

New research from the laboratory of cancer scientist Dr. Tak Mak, renowned for cloning the human T-cell receptor, has demonstrated that immune cells make brain chemicals to fight off infections.

The first proof-of-function findings, published online today in the journal Science, solve a puzzle scientists have pondered for more than a century, says principal investigator Dr. Mak, Director of The Campbell Family Institute for Breast Cancer Research at the Princess Margaret Cancer Centre, University Health Network. He is also a Professor in the Departments of Medical Biophysics and Immunology at the University of Toronto, and a Full Professor in the Pathology Department at the University of Hong Kong.

During infection, T-cells of the immune system synthesize acetylcholine, explains Dr. Mak. In the brain, acetylcholine functions as a neurotransmitter and controls learning and memory. In the immune system, T-cells making this classical brain chemical are able to jump out of the blood circulation and take action in the tissues to fight infection.

First author Maureen Cox summarizes the study findings this way: "The neurotransmitter acetylcholine is produced by T-cells during viral infection to facilitate their entry into tissues under attack, where these cells then kill the virus-infected cells."

The discovery was made when the lab team genetically engineered a mouse lacking the ability to produce the neurotransmitter in T-cells and observed that the immune cells could not control chronic virus infections in its absence.

"We now have absolute genetic proof that immune cells need this brain chemical," says Dr. Mak. "We believe it's an entirely new lens though which to look at numerous diseases including cancer, viral infections and autoimmune conditions."

With respect to cancers, a tumour is often surrounded by immune cells that can't break through its defences, perhaps because the immune cells are not producing sufficient amounts of acetylcholine. In this case, strategies to increase immune neurotransmitter production may be beneficial. The flip side is at play in autoimmune diseases such as rheumatoid arthritis or multiple sclerosis, where the autoimmune T-cells attack self tissues. In this case, a reduction in neurotransmitter signaling may quell the hordes of immune cells invading joints or the central nervous system.

The research builds on the findings of a 2011 study also published in Science in which Dr. Mak participated. That study demonstrated for the first time that immune cells can make acetylcholine.

Dr. Mak says the next research goal is to identify and target the key receptors that facilitate the signalling crosstalk between immune cells and diseased organs.

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Earliest known seed-eating perching bird discovered in Fossil Lake, Wyoming

The 52-million-year-old fossil of Eofringillirostrum boudreauxi, the earliest known perching bird with a beak for eating seeds.

Most of the birds you've ever seen -- sparrows, finches, robins, crows -- have one crucial thing in common: they're all what scientists refer to as perching birds, or "passerines." The passerines make up about 6,500 of the 10,000 bird species alive today. But while they're everywhere now, they were once rare, and scientists are still learning about their origins. In a new paper in Current Biology, researchers have announced the discovery of one of the earliest known passerine birds, from 52 million years ago.

"This is one of the earliest known perching birds. It's fascinating because passerines today make up most of all bird species, but they were extremely rare back then. This particular piece is just exquisite," says Field Museum Neguanee Distinguished Service Curator Lance Grande, an author of the paper. "It is a complete skeleton with the feathers still attached, which is extremely rare in the fossil record of birds."

The paper describes two new fossil bird species -- one from Germany that lived 47 million years ago, and another that lived in what's now Wyoming 52 million years ago, a period known as the Early Eocene. The Wyoming bird, Eofringillirostrum boudreauxi, is the earliest example of a bird with a finch-like beak, similar to today's sparrows and finches. This legacy is reflected in its name; Eofringilllirostrum means "dawn finch beak." (Meanwhile, boudreauxi is a nod to Terry and Gail Boudreaux, longtime supporters of science at the Field Museum.)"

The fossil birds' finch-like, thick beaks hint at their diet. "These bills are particularly well-suited for consuming small, hard seeds," says Daniel Ksepka, the paper's lead author, curator at the Bruce Museum in Connecticut. Anyone with a birdfeeder knows that lots of birds are nuts for seeds, but seed-eating is a fairly recent biological phenomenon. "The earliest birds probably ate insects and fish, some may have been eating small lizards," says Grande. "Until this discovery, we did not know much about the ecology of early passerines. E. boudreauxi gives us an important look at this."

"We were able to show that a comparable diversity of bill types already developed in the Eocene in very early ancestors of passerines," says co-author Gerald Mayr of the Senckenberg Research Institute in Frankfurt. "The great distance between the two fossil sites implies that these birds were widespread during the Eocene, while the scarcity of known fossils suggests a rather low number of individuals," adds Ksepka.

While passerine birds were rare 52 million years ago, E. boudreauxi had the good luck to live and die near Fossil Lake, a site famous for perfect fossilization conditions.

"Fossil Lake is a really graphic picture of an entire community locked in stone -- it has everything from fishes and crocs to insects, pollen, reptiles, birds, and early mammals," says Grande. "We have spent so much time excavating this locality, that we have a record of even the very rare things."

Grande notes that Fossil Lake provides a unique look at the ancient world -- one of the most detailed pictures of life on Earth after the extinction of the dinosaurs (minus the birds) 65 million years ago. "Knowing what happened in the past gives us a better understanding of the present and may help us figure out where we are going for the future."

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A better eyeshot of the makeup of ancient meteorites

Scientists use more powerful imaging techniques to visualize distributions of organic matter (aliphatic C-H) and minerals (sulfates and silicates) in ancient meteorite.

A team of Japanese and American scientists has visualized meteorite components at resolution powers much higher than ever before. Their efforts resulted in a much better look at -- and enhanced understanding of -- substances inside carbonaceous chondrites, the organic-containing meteorites that land on Earth. These substances include hydrogen, carbon, nitrogen and water, all of which are needed for life.

The study was published online on January 2, 2019 in Proceedings of the National Academy of Sciences (PNAS).

Carbonaceous chondrites are made of materials such as rocks, organics, ice, and fine grain dust, most of which are formed in the Solar System. The origin of organic matter that is found in meteorites dates back to the formation of the Solar System, or approximately 4.5 billion years ago. Therefore, when found on Earth and analyzed in detail, these carbonaceous chondrites are helpful for understanding the history of the Solar System, the formation of organic compounds, the presence of water on Earth, and ultimately the origin of life.

Being able to visualize organic and inorganic components of meteorites that have landed on Earth is important because it enables researchers to understand the effects of external factors -- such as water and temperature -- on them. More specifically, a method that enables researchers to better see and analyze the molecular structures ultimately helps them understand the spatial relationships between organic matter and minerals. This is vital for tracing the formation as well as the evolution of organic matter and ultimately understand the history of the formation of the Solar System. Also, understanding the origin of meteorites is crucial for determining the origins of both water and life on the planet.

However, studies to date have been limited with their methods as well as microscopy that has provided images at much lower resolutions. Therefore, formations and evolutions of extraterrestrial organic matter have thus far remained fairly unknown and have only been analyzed after extraction, which is a complicated multi-step process that is prone to many types of methodological errors.

"Researchers have recently mostly conducted analysis for organic matter to see the distributions and associations with inorganic compounds that may help us understand chemistry such as mineral catalyzed synthesis of organic matter, during alteration processes in the meteorite parent asteroids and historic dust processes in the early Solar System. However, since the components of meteorites are very fine, microscopic techniques to analyze such distributions and associations are limited," says Yoko Kebukawa, Ph.D., an Associate Professor at the Faculty of Engineering, Yokohama National University in Japan and the corresponding author of the paper.

Specific to this research, the focus has been on visualizing components of carbonaceous chondrites via a powerful microscopy method that provides images of meteorite components at much better resolutions. This method, atomic force microscopy-based infrared spectroscopy (AFM-IR) enabled the researchers to view the components of two carbonaceous chondrites, the Murchison meteorite and the Bell meteorite at much higher resolutions. This, in turn, provided much more detailed images than those that have been obtained thus far.

"The AFM-IR technique enabled us to overcome the limitation of poor spatial resolution of infrared spectroscopy to see the fine details of organic matter as it is distributed in meteorites and associations of minerals," Kebukawa adds.

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Unusual microbes hold clues to early life

Scientists use the deep-diving robot Jason to collect water samples from oceanic crust at a subseafloor observatory off the coast of Washington. A recent study found that a group of unusual microbes living below the seafloor provides clues to the evolution of life on Earth, and potentially other planets.

A new study has revealed how a group of deep-sea microbes provides clues to the evolution of life on Earth, according to a recent paper in The ISME Journal. Researchers used cutting-edge molecular methods to study these microbes, which thrive in the hot, oxygen-free fluids that flow through Earth's crust.

Called Hydrothermarchaeota, this group of microbes lives in such an extreme environment that they have never been cultivated in a laboratory for study. A research team from Bigelow Laboratory for Ocean Sciences, the University of Hawai'i at Manoa, and the Department of Energy Joint Genome Institute bypassed the problem of cultivation with genetic sequencing methods called genomics, a suite of novel techniques used to sequence large groups of genetic information. They found that Hydrothermarchaeota may obtain energy by processing carbon monoxide and sulfate, which is an overlooked metabolic strategy. The microbes use energy from this process to grow as a form of chemosynthesis.

"The majority of life on Earth is microbial, and most microbes have never been cultivated," said Beth Orcutt, a senior research scientist at Bigelow Laboratory and one of the study's senior authors. "These findings emphasize why single cell genomics are such important tools for discovering how a huge proportion of life functions."

Analyzing Hydrothermarchaeota genomes revealed that these microbes belong to the group of single-celled life known as archaea and evolved early in the history of life on Earth -- as did their unusual metabolic processes. These observations suggest that the subsurface ocean crust is an important habitat for understanding how life evolved on Earth, and potentially other planets.

The researchers also found genetic evidence that Hydrothermarchaeota have the ability to move on their own. Motility offers a valuable survival strategy for the extreme environment they call home, which has a limited supply of nutrients essential to life.

"Studying these unique microbes can give us insights into both the history of Earth and the potential strategies of life on other planets," said Stephanie Carr, first author on the paper and a former postdoctoral researcher with Orcutt who is now an assistant professor at Hartwick College. "Their survival strategies make them incredibly versatile, and they play an important, overlooked role in the subsurface environments where they live."

In 2011, Orcutt and other project scientists sailed to the flank of the Juan de Fuca Ridge, a mid-ocean ridge off the coast of Washington where two ocean plates are separating and generating new oceanic crust. They used Woods Hole Oceanographic Institution's deep-diving robot Jason to travel 2.6 km to the seafloor and collect samples of the fluid that flows through the deep crust.

These crustal fluids contained microbes that had never before been studied. Working in partnership with the Department of Energy Joint Genome Institute, the researchers sorted and analyzed the microbes in the Single Cell Genomics Center at Bigelow Laboratory. This cutting-edge research facility is directed by Ramunas Stepanauskas, a senior research scientist and study author. The project team also analyzed the microbes using metagenomics, a technique that extracts genomic information directly from environmental samples. These analyses yielded insights into the genetic blueprints of Hydrothermarchaeota, their relationship to other archaea, and the strategies they have evolved to survive in the subseafloor.

The researchers will build upon this discovery when they return to the Juan de Fuca Ridge in May 2019 to continue investigating the extreme microbes thriving below the seafloor. Orcutt will lead a cruise using ROV Jason with this team of researchers to further explore the subseafloor environment, leveraging funding from the National Science Foundation and NASA.

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Life thrived on Earth 3.5 billion years ago, research suggests

Electron microscopy image of microbial cells which respire sulfate.

3.5 billion years ago Earth hosted life, but was it barely surviving, or thriving? A new study carried out by a multi institutional team with leadership including the Earth-Life Science Institute (ELSI) of Tokyo Institute of Technology (Tokyo Tech) provides new answers to this question. Microbial metabolism is recorded in billions of years of sulfur isotope ratios that agree with this study's predictions, suggesting life throve in the ancient oceans. Using this data, scientists can more deeply link the geochemical record with cellular states and ecology.

Scientists want to know how long life has existed on Earth. If it has been around for almost as long as the planet, this suggests it is easy for life to originate and life should be common in the Universe. If it takes a long time to originate, this suggests there were very special conditions that had to occur. Dinosaurs, whose bones are presented in museums around the world, were preceded by billions of years by microbes. While microbes have left some physical evidence of their presence in the ancient geological record, they do not fossilize well, thus scientists use other methods for understanding whether life was present in the geological record.

Presently, the oldest evidence of microbial life on Earth comes to us in the form of stable isotopes. The chemical elements charted on the periodic are defined by the number of protons in their nuclei, for example, hydrogen atoms have one proton, helium atoms have two, carbon atoms contain six. In addition to protons, most atomic nuclei also contain neutrons, which are about as heavy as protons, but which don't bear an electric charge. Atoms which contain the same number of protons, but variable numbers of neutrons are known as isotopes. While many isotopes are radioactive and thus decay into other elements, some do not undergo such reactions; these are known as "stable" isotopes. For example, the stable isotopes of carbon include carbon 12 (written as 12C for short, with 6 protons and 6 neutrons) and carbon 13 (13C, with 6 protons and 7 neutrons).

All living things, including humans, "eat and excrete." That is to say, they take in food and expel waste. Microbes often eat simple compounds made available by the environment. For example, some are able to take in carbon dioxide (CO2) as a carbon source to build their own cells. Naturally occurring CO2 has a fairly constant ratio of 12C to 13C. However, 12CO2 is about 2 % lighter than 13CO2, so 12CO2 molecules diffuse and react slightly faster, and thus the microbes themselves become "isotopically light," containing more 12C than 13C, and when they die and leave their remains in the fossil record, their stable isotopic signature remains, and is measurable. The isotopic composition, or "signature," of such processes can be very specific to the microbes that produce them.

Besides carbon there are other chemical elements essential for living things. For example, sulfur, with 16 protons, has three naturally abundant stable isotopes, 32S (with 16 neutrons), 33S (with 17 neutrons) and 34S (with 18 neutrons). Sulfur isotope patterns left behind by microbes thus record the history of biological metabolism based on sulfur-containing compounds back to around 3.5 billion years ago. Hundreds of previous studies have examined wide variations in ancient and contemporary sulfur isotope ratios resulting from sulfate (a naturally occurring sulfur compound bonded to four oxygen atoms) metabolism. Many microbes are able to use sulfate as a fuel, and in the process excrete sulfide, another sulfur compound. The sulfide "waste" of ancient microbial metabolism is then stored in the geological record, and its isotope ratios can be measured by analyzing minerals such as the FeS2 mineral pyrite.

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Shedding light on the science of auroral breakups

All-sky images of the auroral breakup that occurred around 2220 UT on June 30, 2017. Photographed at Syowa Station, Antarctica. Left: five minutes before the breakup. Right: right after the breakup.

Auroras, also known as Northern or Southern lights depending on whether they occur near the North or South Pole, are natural displays of light in the Earth's sky. Typically these lights are dimly present at night. However, sometimes these otherwise faint features explode in brightness and can even break up into separate glowing hallmarks, appearing as spectacular bursts of luminous manifestations. This striking and picturesque phenomenon is known as an auroral breakup.

Now, Japanese scientists have quantitatively confirmed how energetic this phenomenon can be. Using a combination of cutting-edge ground-based technology and new space-borne observations, they have demonstrated the essential role of an auroral breakup in ionizing the deep atmosphere. The research furthers our understanding of one of the most visually stunning natural phenomena.

The findings were published in Earth, Planets and Space on January 23, 2019.

The sun fires beams of charged particles, or plasma, toward Earth. Also referred to as solar winds, this plasma is mostly made up of electrons, protons and alpha particles. When these particles interact with the Earth's magnetic field, electrical currents are carried by electrons into the Earth's atmosphere. This reaction between the electrons and their atmospheric constituents emits light of varying color and complexity, visible as an aurora. However, little is known about how energetic the electrons can be when these lights explode into the stunning lightshows known as auroral breakups. So far, the assumption has been that electrons of a specific energy level are responsible for this rare phenomenon.

In the new study, the scientists report that, contrary to conventional thinking, a specific kind of electrons with much higher energy, called radiation belt electrons, are involved in the auroral breakup. Named after their location in the Earth's radiation belt, radiation belt electrons had not been clearly associated with auroral breakups before. The research team based their conclusions on a dataset collected via advanced technology and simulations.

"Radiation belt electrons are released from the Earth's magnetic field and charge the mesosphere during auroral breakup. This fact was quantitatively confirmed by both cutting-edge ground-based and new space-borne observations," adds Ryuho Kataoka, Ph.D., associate professor at the National Institute of Polar Research and the corresponding author. "This study also provides a good example how Arase satellite and PANSY radar can collaborate to understand the connection between space and atmosphere."

In their future research endeavors, the Professor Kataoka and his team hope to understand how the radiation belt electrons are released during the short-lasting period of auroral breakup. "The ultimate goal is to understand the interplay between auroras and radiation belts," Professor Kataoka adds.

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Liberal sprinkling of salt discovered around a young star

Artist impression of Orion Source I, a young, massive star about 1,500 light-years away. New ALMA observations detected a ring of salt -- sodium chloride, ordinary table salt -- surrounding the star. This is the first detection of salts of any kind associated with a young star. The blue region (about 1/3 the way out from the center of the disk) represents the region where ALMA detected the millimeter-wavelength "glow" from the salts.

A team of astronomers and chemists using the Atacama Large Millimeter/submillimeter Array (ALMA) has detected the chemical fingerprints of sodium chloride (NaCl) and other similar salty compounds emanating from the dusty disk surrounding Orion Source I, a massive, young star in a dusty cloud behind the Orion Nebula.

"It's amazing we're seeing these molecules at all," said Adam Ginsburg, a Jansky Fellow of the National Radio Astronomy Observatory (NRAO) in Socorro, New Mexico, and lead author of a paper accepted for publication in the Astrophysical Journal. "Since we've only ever seen these compounds in the sloughed-off outer layers of dying stars, we don't fully know what our new discovery means. The nature of the detection, however, shows that the environment around this star is very unusual."

To detect molecules in space, astronomers use radio telescopes to search for their chemical signatures -- telltale spikes in the spread-out spectra of radio and millimeter-wavelength light. Atoms and molecules emit these signals in several ways, depending on the temperature of their environments.

The new ALMA observations contain a bristling array of spectral signatures -- or transitions, as astronomers refer to them -- of the same molecules. To create such strong and varied molecular fingerprints, the temperature differences where the molecules reside must be extreme, ranging anywhere from 100 kelvin to 4,000 kelvin (about -175 Celsius to 3700 Celsius). An in-depth study of these spectral spikes could provide insights about how the star is heating the disk, which would also be a useful measure of the luminosity of the star.

"When we look at the information ALMA has provided, we see about 60 different transitions -- or unique fingerprints -- of molecules like sodium chloride and potassium chloride coming from the disk. That is both shocking and exciting," said Brett McGuire, a chemist at the NRAO in Charlottesville, Virginia, and co-author on the paper.

The researchers speculate that these salts come from dust grains that collided and spilled their contents into the surrounding disk. Their observations confirm that the salty regions trace the location of the circumstellar disk.

"Usually when we study protostars in this manner, the signals from the disk and the outflow from the star get muddled, making it difficult to distinguish one from the other," said Ginsburg. "Since we can now isolate just the disk, we can learn how it is moving and how much mass it contains. It also may tell us new things about the star."

The detection of salts around a young star is also of interest to astronomers and astrochemists because some of constituent atoms of salts are metals -- sodium and potassium. This suggests there may be other metal-containing molecules in this environment. If so, it may be possible to use similar observations to measure the amount of metals in star-forming regions. "This type of study is not available to us at all presently. Free-floating metallic compounds are generally invisible to radio astronomy," noted McGuire.

The salty signatures were found about 30 to 60 astronomical units (AU, or the average distance between the Earth and the Sun) from the host stars. Based on their observations, the astronomers infer that there may be as much as one sextillion (a one with 21 zeros after it) kilograms of salt in this region, which is roughly equivalent to the entire mass of Earth's oceans.

"Our next step in this research is to look for salts and metallic molecules in other regions. This will help us understand if these chemical fingerprints are a powerful tool to study a wide range of protoplanetary disks, or if this detection is unique to this source," said Ginsburg. "In looking to the future, the planned Next Generation VLA would have the right mix of sensitivity and wavelength coverage to study these molecules and perhaps use them as tracers for planet-forming disks."

Orion Source I formed in the Orion Molecular Cloud I, a region of explosive starbirth previously observed with ALMA. [And here.] "This star was ejected from its parent cloud with a speed of about 10 kilometers per second around 550 years ago," said John Bally, an astronomer at the University of Colorado and co-author on the paper. "It is possible that solid grains of salt were vaporized by shock waves as the star and its disk were abruptly accelerated by a close encounter or collision with another star. It remains to be seen if salt vapor is present in all disks surrounding massive protostars, or if such vapor traces violent events like the one we observed with ALMA."

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

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Periodic table still influencing today's research

The periodic table is still influencing research today.

This year marks the 150th anniversary of the Periodic Table, and the principles that drove Dmitri Mendeleev to construct his table are still influencing today's research advances.

In a special issue of Science, which celebrates this sesquicentennial anniversary, a Michigan State University scientist highlights some of the current research around the globe driven by Mendeleev's influence.

"Our goal was to showcase contemporary research being pursued around the world, including U.S. Department of Energy-supported research at MSU, that's working to realize new approaches to photoinduced chemical processes," said James McCusker, MSU chemist and review author.

McCusker's contribution focused on the process of light absorption that incorporates elements from the so-called "transition block" of the Periodic Table. Compounds from this class are involved in everything from solar energy conversation to organic synthesis.

"The effective capture and use of sunlight -- an inexhaustible, globally accessible and pollution-free energy source -- is critical for replacing fossil fuels and in mitigating climate change," McCusker said. "In order to realize this goal, one of the key processes that must occur following the absorption of light is the transfer of electrons, similar to what plants do in photosynthesis."

But unleashing this capability has proved challenging. That's due, in part, to the fact that the compounds that are very effective at converting light into useable charge require the use of some of the least-abundant elements on the planet. Take for example ruthenium and iridium, which are widely employed in chromophores that can carry out these light-enabled chemical processes.

"Ruthenium is one of the five or six least-abundant elements in Earth's crust and is simply not a viable option as the light-harvesting component for a globally scaled problem like solar fuel production," McCusker said. "We need to find replacements that are abundant on Earth, such as iron, to make global scalability possible. This is not an engineering or manufacturing problem, but one of fundamental science that has its origins in the very concepts that Mendeleev uncovered when he constructed the periodic table."

That's where some of MSU's DOE-supported research comes into play. McCusker's research is based on a confluence of synthetic organic and inorganic chemistries as well as a range of spectroscopic techniques.

"Of particular importance with regard to our solar energy conversion efforts is ultrafast time-resolved laser spectroscopy, which allows us to track the evolution of a chemical system less than one trillionth of a second after light has been absorbed," McCusker said. "The ability to combine synthesis and ultrafast spectroscopy in one laboratory is a critically important aspect of the research since it allows my students and I to make immediate connections between the composition of the molecules we prepare and their light-induced properties."

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Fish Appear to Recognize Themselves in the Mirror

A cleaner wrasse interacts with its reflection in a mirror placed on the outside of the aquarium glass. Note that the mirror itself cannot be seen in this photo because the aquarium glass itself becomes reflective at the viewing angle of the camera, according to Snell's law. This is not the case for the fish itself, which sees the aquarium glass as transparent because of its direct viewing angle.

A species of fish, the cleaner wrasse (Labroides dimidiatus), responds to its reflection and attempts to remove marks on its body during the mirror test -- a method held as the gold standard for determining if animals are self-aware. The finding, publishing on February 7 in the open-access journal PLOS Biology, suggests that fish might possess far higher cognitive powers than previously thought, and ignites a high-stakes debate over how we assess the intelligence of animals that are so unlike ourselves.

The study's researchers from the Max Planck Institute for Ornithology (MPIO) and Osaka City University (OCU), say that their results provide clear evidence of behaviours that appear to pass through all phases of the mirror test, but that the interpretation of what these mean is less clear: Does a 'pass' mark in the mirror test demonstrate that fish possess self-awareness -- a cognitive trait thought only to be present in primates and some other mammals? Or can the mirror test be solved by very different cognitive processes than previously thought?

"The behaviours we observe leave little doubt that this fish behaviourally fulfils all criteria of the mirror test as originally laid out. What is less clear is whether these behaviours should be considered as evidence that fish are self-aware -- even though in the past these same behaviours have been interpreted as self-awareness in so many other animals," says Dr Alex Jordan, senior author on the study.

The ability to perceive and recognise a reflected mirror image as self (mirror self-recognition) is considered a hallmark of cognition across species. To test for this phenomenon in fish, the researchers applied the classic 'mark' test to the cleaner wrasse (Labroides dimidiatus) -- a marine fish best known for its behaviour of "cleaning" external parasites from client fish -- by placing a coloured mark on fish in a location that can only be seen in a mirror reflection. In order to gain a 'pass', the test requires that the animal must touch or investigate the mark, demonstrating that it perceives the reflected image as itself. This is clearly a challenge for animals such as fish that lack limbs and hands.

The researchers observed that fish attempted to remove the marks by scraping their bodies on hard surfaces after viewing themselves in the mirror. Fish never attempted to remove transparent marks in the presence of a mirror, or coloured marks when no mirror was present -- suggesting that marked fish were responding to the visual cue of seeing the mark on themselves in the mirror. Further, unmarked fish did not attempt to remove marks from themselves when interacting with a marked fish across a clear divider, nor did they attempt to remove marks placed on the mirror itself -- suggesting that fish were not innately reacting to a mark resembling an ectoparasite anywhere in the environment, for instance due to hard-wired feeding responses.

Dr Jordan acknowledges the controversial nature of the study, saying: "Depending on your position, you might reject the interpretation that these behaviours in a fish satisfy passing the test at all. But on what objective basis can you do this when the behaviours they show are so functionally similar to those of other species that have passed the test?"

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Bees can do basic arithmetic

Honeybee.

Researchers have found bees can do basic mathematics, in a discovery that expands our understanding of the relationship between brain size and brain power.

Building on their finding that honeybees can understand the concept of zero, Australian and French researchers set out to test whether bees could perform arithmetic operations like addition and subtraction.

Solving maths problems requires a sophisticated level of cognition, involving the complex mental management of numbers, long-term rules and short term working memory.

The revelation that even the miniature brain of a honeybee can grasp basic mathematical operations has implications for the future development of Artificial Intelligence, particularly in improving rapid learning.

Led by researchers from RMIT University in Melbourne, Australia, the new study showed bees can be taught to recognise colours as symbolic representations for addition and subtraction, and that they can use this information to solve arithmetic problems.

RMIT's Associate Professor Adrian Dyer said numerical operations like addition and subtraction are complex because they require two levels of processing.

"You need to be able to hold the rules around adding and subtracting in your long-term memory, while mentally manipulating a set of given numbers in your short-term memory," Dyer said.

"On top of this, our bees also used their short-term memories to solve arithmetic problems, as they learned to recognise plus or minus as abstract concepts rather than being given visual aids.

"Our findings suggest that advanced numerical cognition may be found much more widely in nature among non-human animals than previously suspected.

"If maths doesn't require a massive brain, there might also be new ways for us to incorporate interactions of both long-term rules and working memory into designs to improve rapid AI learning of new problems."

There is considerable debate around whether animals know or can learn complex number skills.

Many species can understand the difference between quantities and use this to forage, make decisions and solve problems. But numerical cognition, such as exact number and arithmetic operations, requires a more sophisticated level of processing.

Previous studies have shown some primates, birds, babies and even spiders can add and/or subtract. The new research, published in Science Advances, adds bees to that list.

A school for bees? How the honeybees were trained

The experiment, conducted by PhD researcher Scarlett Howard in the Bio Inspired Digital Sensing-Lab (BIDS-Lab) at RMIT, involved training individual honeybees to visit a Y-shaped maze.

The bees received a reward of sugar water when they made a correct choice in the maze, and received a bitter-tasting quinine solution if the choice was incorrect.

Honeybees will go back to a place if the location provides a good source of food, so the bees returned repeatedly to the experimental set-up to collect nutrition and continue learning.

When a bee flew into the entrance of the maze they would see a set of elements, between 1 to 5 shapes.

The shapes were either blue, which meant the bee had to add, or yellow, which meant the bee had to subtract.

After viewing the initial number, the bee would fly through a hole into a decision chamber where it could choose to fly to the left or right side of the maze.

One side had an incorrect solution to the problem and the other side had the correct solution of either plus or minus one. The correct answer was changed randomly throughout the experiment to avoid bees learning to visit just one side of the maze.

At the beginning of the experiment, bees made random choices until they could work out how to solve the problem. Eventually, over 100 learning trials that took 4 to 7 hours, bees learned that blue meant +1, while yellow meant -1. The bees could then apply the rules to new numbers.

Scarlett Howard said the ability to do basic maths has been vital in the flourishing of human societies historically, with evidence that the Egyptians and Babylonians used arithmetic around 2000BC.

"These days, we learn as children that a plus symbol means you need to add two or more quantities, while a minus symbol means you subtract," she said.

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Beaked whales' incredible diving abilities confirmed

A Duke-led study sheds new light on the remarkable diving behaviors of Cuvier's beaked whales, the world's deepest-diving mammals.

A new Duke University-led study provides the first detailed record of the diving behavior of Cuvier's beaked whales in U.S. Atlantic waters.

Cuvier's beaked whales are the world's deepest-diving mammal, but studies of their behavior are constrained by the animals' offshore location and limited time spent at the surface.

The new data, recorded from 5,926 dives of tagged whales off Cape Hatteras, N.C., showcases the remarkable diving abilities of these animals and provides new clues to how they make a living at the extremes of depth and cold.

"Their deep dives average about 1,400 meters, lasting about an hour, while they are feeding near the sea floor. They typically only spend about two minutes at the surface between dives," said Jeanne Shearer, a doctoral student in ecology at Duke University's Nicholas School of the Environment. "It's amazing that they can dive to such depths, withstand the pressure, and be down there that long, with such brief recovery times."

Past studies have documented the diving behavior of Cuvier's beaked whales in Pacific waters, Italy, and the Bahamas, but this is the first one focused in the U.S. Atlantic. Scientists estimate about 6,500 Cuvier's beaked whales live in the northwest Atlantic. Populations in different areas exhibit some differences in diving behavior, highlighting the need for data from around the world.

To conduct the study, scientists attached LIMPET satellite-linked tags to 11 Cuvier's beaked whales that live and dive most of the year in waters a two-hour boat ride from Cape Hatteras. One tag failed, but the other 10 recorded 3,242 hours of behavioral data from 5,926 individual dives -- both deep and shallow -- between 2014 and 2016.

Aside from the extremely deep dives that these whales are able to make, the data showed that they dive nearly continually, with deep dives followed by 3-4 shallow dives that extend to around 300 meters. How they continuously dive to these depths without long recovery periods is still a mystery to scientists.

"Cuvier's beaked whales are only half the size of the sperm whale," Shearer said. "Their dives push the limits of mammalian physiology, but we still don't know how they're able to behave this way."

She and her colleagues published their peer-reviewed findings Feb. 6 in the journal Royal Society Open Science.

Aside from adding to our knowledge of the species' remarkable diving capability, the findings provide a baseline for controlled experiments, now underway at Duke, to study their reactions to low levels of sonar.

"It's important to understand their typical diving behavior in order to interpret the results of behavioral response studies," said Shearer, who conducts her research at the Duke University Marine Laboratory in Beaufort, N.C.

Read more at Science Daily

A billion years of coexistence between plants and fungi

What can a billion years of coexistence tell us about the evolution of plants and fungi?

Neither plants nor fungi existed on land prior to 800 million years ago, an astonishing phenomenon considering their current immense biodiversity, ecosystem dominance, and impact on the environment.

Virginia Tech professor emeritus Khidir Hilu, along with a team of 13 researchers with complementary expertise in botany, mycology, paleontology, and bioinformatics, joined forces to address this question in a large-scale study published in Nature Communications.

"The movements of plant and fungi to land have irreversibly modified our planet physically and shaped their own biodiversity as well as that of the animal kingdom," said Hilu, professor emeritus of the Department of Biological Sciences in the College of Science. "Our research shows that the successful plant and fungi invasion of land was an outcome of co-evolutionary interaction between the two that enhanced their biodiversities. These findings are timely considering current issues in climate change and notable extinctions experienced by plants and animals and the impact on our planet."

The authors noted that although interactions between fungi and plants, including parasitism, mutualism (beneficial to both organisms), and saprotrophy (obtaining nutrients from dead plant parts), have been invoked as key mechanisms to their success, no one has explored contemporaneous evolutionary events throughout their history.

In this article, the authors methodologically explored the evolution of plants and fungi in a multiprong approach using molecular and bioinformatic techniques. They first established robust phylogenies, or evolutionary histories, for plants and fungi independently using gene sequence data generated in their labs or obtained from repositories of genome sequences.

Next, they estimated evolutionary divergence dates of plant and fungal lineages using both gene mutations and reliable fossil records. They then computed major shifts in diversification rates of major lineages in the two kingdoms independently. Once these studies were accomplished, the resulting phylogenetic relationships for plants and fungi were aligned on the same geological time scale, which allowed the researchers to pinpoint the origins of various key plant-fungal co-evolutionary events, particularly symbiotic relationships and the decomposition of plants by fungi. They noticed drastic shifts in diversification rates in the two kingdoms that convincingly showed plant-fungal co-evolution and interdependence across their long history.

The authors reported that fungal colonization of land was associated with and helped by at least two originations of terrestrial green algae, which preceded the origin of land plants. This coincided with the loss, ca. 720 million years ago, of fungal flagellum, a lash-like appendage that helps fungi swim in water.

Conversely, many million years later, during the Paleozoic Era, successful colonization of land by the lineage that eventually gave rise to all terrestrial plants living today was likely facilitated by fungi, specifically through fungal occupation of cells of the earliest land plants, promoting mutualism, which was key to plant and fungi success on land.

One of the significant biological, ecological, and environmental events on Earth is the origin and initial diversification of a lineage containing all plants that bear seeds. Seed plants, which include conifers and flowering plants, emerged during the Silurian Period about 436 million years ago. Significantly, one of the distinguishing traits of this plant lineage was the presence of a distinctive type of cell division that gave rise to wood. This led to the evolution of large woody trees, which in turn, resulted in the establishment of the first inland forests based on lignin-rich wood as their backbone.

Such a move could not have been successful without the linked evolution with fungi and their capacity to digest the structural polymer lignin and cellulose of plant cell walls. This evolutionary novelty was instrumental in organic matter recycling, which led to the forest system being sustained. The origin and early diversification of the seed plant lineage was in turn followed by the evolution of the largest classes of fungi, the Agaricomycetes.

The origin of ectomycorrhizal fungi (fungi associated externally with plant roots) seems to have resulted from a series of evolutionary innovations in plants including the origins of wood, seeds, and roots. These consequential evolutionary events were crucial in promoting the diversification leading to existing seed plants, including cone-bearing plants such as pines, spruces, maidenhairs, and cycads, as well as flowering plants, and their expansion to drier environments.

The latter group, in addition to including most living plant species and major ecosystems, such as forests and grasslands, also encompasses an astounding diversity in form and function and provides almost all of our food plants. Ectomycorrhizal fungi form a symbiotic relationship with plants and can produce networks around the plant roots to aid in water and nutrient uptake, often assisting the host plant to survive adverse weather conditions.

The macroevolution of plants and fungi has been studied mostly separately; however, this study clearly demonstrates that their respective evolutionary histories are deeply interconnected and can be understood only through a simultaneous study of their phylogenies within a robust timeframe.

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Melting ice sheets may cause 'climate chaos' according to new modelling

Melting ice off Greenland.

The weather these days is wild and will be wilder still within a century -- in part, because the water from melting ice sheets off Greenland and in the Antarctic will cause extreme weather and unpredictable temperatures around the globe. A study published today in Nature is the first to simulate the effects, under current climate policies, that the two melting ice sheets will have on ocean temperatures and circulation patterns as well as on air temperatures by the year 2100.

Consequences for ocean circulation and water and air temperatures

"Under current global government policies, we are heading towards 3 or 4 degrees of warming above pre-industrial levels, causing a significant amount of melt water from the Greenland and Antarctic Ice Sheets to enter Earth's oceans. According to our models, this melt water will cause significant disruptions to ocean currents and change levels of warming around the world," says Associate Professor Nick Golledge from Victoria University of Wellington's Antarctic Research Centre in New Zealand. He led the international research team made up of scientists from Canada, New Zealand, the UK, Germany and the USA.

The research team combined highly detailed simulations of the complex climate effects of the melting with satellite observations of recent changes to the ice sheets. As a result, the researchers have been able to create more reliable and accurate predictions of what will occur under current climate policies.

Warming in Eastern Canada and cooling in Northwestern Europe

Professor Natalya Gomez, from the Department of Earth and Planetary Sciences at McGill contributed to the study by modelling projected changes to water levels around the globe as ice melts into the ocean. The ice sheet simulations suggest that the fastest increase in the rise of sea levels is likely to occur between 2065 and 2075. Melting ice sheets will affect water temperatures and circulation patterns in the world's oceans, which will in turn affect air temperatures -- in a complex ice-ocean-atmosphere feedback loop.

"Water levels would not simply rise like a bathtub," says Gomez. "Some areas in the world, such as the island nations in the Pacific, would experience a large rise in sea level, while close to the ice sheets the sea level would actually fall."

However, the effects of ice sheet melt are far more widespread than simply leading to changes in sea levels. As warmer melt water enters the oceans, for example in the North Atlantic Ocean, major ocean currents such as the Gulf Stream will be significantly weakened. This will lead to warmer air temperatures in the high Arctic, Eastern Canada and Central America, and cooler temperatures over northwestern Europe on the other side of the Atlantic.

New information to help shape future climate policies

According to the researchers, current global climate policies set in place under the Paris Agreement do not take into account the full effects of ice sheet melt likely to be seen in future.

"Sea level rise from ice sheet melt is already happening and has been accelerating in recent years. Our new experiments show that this will continue to some extent even if Earth's climate is stabilized. But they also show that if we drastically reduce emissions, we can limit future impacts," says Golledge.

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Scientists study organization of life on a planetary scale

This graph represents the biosphere, ecosystems and individual organisms' biochemistry as connecting molecules participating in shared reactions. It reveals that various scaling laws are common across different levels of biological organization.

When we think of life on Earth, we might think of individual examples ranging from animals to bacteria. When astrobiologists study life, however, they have to consider not only individual organisms, but also ecosystems, and the biosphere as a whole.

In astrobiology, there is an increasing interest in whether life as we know it is a quirk of the particular evolutionary history of the Earth or, instead, if life might be governed by more general organizing principles.

If general principles exist that can explain properties common to all life on Earth, scientists hypothesize, then they may be universal to all life, even life on other planets. If a "universal biology" exists, it would have important implications for the search for life beyond Earth, for engineering synthetic life in the lab, and for solving the origin of life, enabling scientists to predict at least some properties of alien life.

Previous research in this area has primarily focused on specific levels of organization within biology such as individual organisms or ecological communities. These levels form a hierarchy where individuals are composed of interacting molecules and ecosystems are composed of interacting individuals.

An interdisciplinary team of researchers at Arizona State University (ASU) has gone beyond focusing on individual levels in this hierarchy to study the hierarchy itself, focusing on the biosphere as a whole. The results of their study have been recently published Science Advances.

"To understand the general principles governing biology, we must understand how living systems organize across levels, not just within a given level," says lead author Hyunju Kim of ASU's Beyond Center and the School of Earth and Space Exploration.

Through this study, the team found that biochemistry, both at the level of organisms and ecosystems, is governed by general organizing principles. "This means there is a logic to the planetary-scale organization of biochemistry," says co-lead author Harrison Smith of ASU's School of Earth and Space Exploration. "Scientists have talked about this type of logic for a long time, but until now they have struggled to quantify it. Quantifying it can help us constrain the way that life arises on a planet."

For this research, the team constructed biochemical networks using a global database of 28,146 annotated genomes and metagenomes and 8,658 catalogued biochemical reactions. In so doing, they uncovered scaling laws governing biochemical diversity and network structure that are shared across levels of organization from individuals to ecosystems, to the biosphere as a whole.

"Quantifying general principles of life -- not restricted to a domain on the tree of life, or a particular ecosystem -- is a challenge," says Smith. "We were able to do that by combining tools from network science and scaling theory, while simultaneously leveraging large genomic datasets that researchers have been cataloging."

The research team, led by Kim and Smith under supervision of Sara Walker of the ASU School of Earth and Space Exploration and the Beyond Center, also includes Cole Mathis of the Beyond Center and the ASU Department of Physics (now at the University of Glasgow), and Jason Raymond of the School of Earth and Space Exploration.

Read more at Science Daily

First accurate 3D map of the Milky Way reveals a warped galaxy

A slightly exaggerated impression of the real shape of our warped and twisted Milky Way.

Our Milky Way galaxy’s disk of stars is anything but stable and flat. Instead, it becomes increasingly ‘warped’ and twisted far away from the Milky Way’s centre, according to astronomers from Macquarie University and the Chinese Academy of Sciences, who have built the first accurate 3D map of Earth’s home galaxy and unveiled it today in a paper published in Nature Astronomy.
o;s centre, according to astronomers from Macquarie University and the Chinese Academy of Sciences, who have built the first accurate 3D map of Earth’s home galaxy and unveiled it today in a paper published in Nature Astronomy.

From a great distance, our galaxy would look like a thin disk of stars that orbit once every few hundred million years around its central region, where hundreds of billions of stars provide the gravitational ‘glue’ to hold it all together.

But the pull of gravity becomes weaker far away from the Milky Way’s inner regions. In the galaxy’s far outer disk, the hydrogen atoms making up most of the Milky Way’s gas disk are no longer confined to a thin plane, but they give the disk an S-like, warped appearance.

“It is notoriously difficult to determine distances from the sun to parts of the Milky Way’s outer gas disk without having a clear idea of what that disk actually looks like,” says Xiaodian Chen, a researcher at the Chinese Academy of Sciences in Beijing and lead author of the article in Nature Astronomy.

“However, we recently published a new catalogue of well-behaved variable stars known as classical Cepheids, for which distances as accurate as 3 to 5 per cent can be determined.” That database allowed the team to develop the first accurate three-dimensional picture of our Milky Way out to its far outer regions.

Classical Cepheids are young stars that are some four to 20 times as massive as our Sun and up to 100,000 times as bright. Such high stellar masses imply that they live fast and die young, burning through their nuclear fuel very quickly, sometimes in only a few million years.

They show day- to month-long pulsations, which are observed as changes in their brightness. Combined with a Cepheid’s observed brightness, its pulsation period can be used to obtain a highly reliable distance.

“Somewhat to our surprise, we found that in 3D our collection of 1339 Cepheid stars and the Milky Way’s gas disk follow each other closely. This offers new insights into the formation of our home galaxy,” says Macquarie University’s Professor Richard de Grijs, astronomer and senior co-author on the paper.

“Perhaps more important, in the Milky Way’s outer regions, we found that the S-like stellar disk is warped in a progressively twisted spiral pattern.”

This reminded the team of earlier observations of a dozen other galaxies which also showed such progressively twisted spiral patterns.

Combining their new results with those other observations, the researchers concluded that the Milky Way’s warped spiral pattern is most likely caused by ‘torques’ – or rotational forcing – by the massive inner disk.

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Even psychological placebos have an effect

The color green can have a positive effect on the personal condition, as long as this effect was previously attributed to it.

Placebo effects do not only occur in medical treatment -- placebos can also work when psychological effects are attributed to them. Psychologists from the University of Basel reported these findings in the journal Scientific Reports, based on three studies with over 400 participants.

Psychotherapy and placebos are both psychological interventions that not only have comparable effects, but that are also based on very similar mechanisms. Both forms of treatment are heavily influenced by the relationship between patients and those treating them, as well as by the expectations of recovery. Whereas placebo research mostly focuses on a biomedical model -- an inert pill is provided with a medical rationale, which produces a corresponding effect -- little is known about the effect of placebos provided with a psychological rationale.

"Green is calming"

Placebos can also have effects when specific psychological effects are attributed to them. This is the conclusion that researchers from the Division of Clinical Psychology and Psychotherapy at the University of Basel reached in three independent experiments with 421 healthy participants. The accompanying explanation -- the narrative -- played a key role when dispensing the placebos, as did the relationship between the researchers and the participants.

The researchers used the color green as the placebo in the video experiments, examining it both with and without a psychological narrative ("green is calming because it activates early conditioned emotional schemata"), as well as in the context of a neutral or a friendly relationship.

After viewing the videos, the participants assessed their subjective condition with questionnaires over several days. The results showed that the placebo had a positive effect on the participants' well-being when it was prescribed together with a psychological narrative and in the context of a friendly relationship. The observed effect was strongest after administering the placebo but remained evident for up to one week.

Ethical implications

"The observed effects were comparable with those of psychotherapeutic interventions in the same populations," says principal investigator Professor Jens Gaab. The fact that psychological placebos can have significant effects is not only important for understanding psychological interventions: "It challenges both research and clinical practice to address these mechanisms and effects, as well as their ethical implications."

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A warming world increases air pollution

Climate change is warming the ocean, but it's warming land faster and that's really bad news for air quality all over the world, says a new University of California, Riverside study.

The study, published February 4 in Nature Climate Change, shows that the contrast in warming between the continents and sea, called the land-sea warming contrast, drives an increased concentration of aerosols in the atmosphere that cause air pollution.

Aerosols are tiny solid particles or liquid droplets suspended in the atmosphere. They can come from natural sources, like dust or wildfires, or human-made sources such as vehicle and industrial emissions. Aerosols affect the climate system, including disturbances to the water cycle, as well as human health. They also cause smog and other kinds of air pollution that can lead to health problems for people, animals, and plants.

"A robust response to an increase in greenhouse gases is that the land is going to warm faster than the ocean. This enhanced land warming is also associated with increased continental aridity," explained first author Robert Allen, an associate professor of earth sciences at UC Riverside.

The increase in aridity leads to decreased low cloud cover and less rain, which is the main way that aerosols are removed from the atmosphere.

To determine this, the researchers ran simulations of climate change under two scenarios. The first assumed a business-as-usual warming model, in which warming proceeds at a constant, upward rate. The second model probed a scenario in which the land warmed less than expected.

In the business-as-usual scenario, enhanced land warming increased continental aridity and, subsequently, the concentration of aerosols that leads to more air pollution. However, the second model -- which is identical to the business-as-usual model except the land warming is weakened -- leads to a muted increase in continental aridity and air pollution. Thus, the increase in air pollution is a direct consequence of enhanced land warming and continental drying.

The results show that the hotter Earth gets, the harder it's going to be to keep air pollution down to a certain level without strict control over the sources of aerosols.

Because the researchers wanted to understand how greenhouse gas warming affects air pollution, they assumed no change to human-made, or anthropogenic, aerosol emissions.

"That's probably not going to be true because there's a strong desire to reduce air pollution, which involves reducing anthropogenic aerosol emissions," cautioned Allen. "So this result represents an upper bound."

But it also suggests that if the planet keeps warming, larger reductions in anthropogenic aerosol emissions will be required to improve air quality.

"The question is what level of air quality are we going to accept," said Allen. "Even though California has some of the strictest environmental laws in the country we still have relatively poor air quality, and it's much worse in many countries."

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Think pink: Fluorescent pink flying squirrel in UV light at night

Photographs of a flying squirrel with visuals from the human eye and under ultraviolet light.

The North American flying squirrel fluoresces pink at night under ultraviolet light, but the purpose of the pink color is still a mystery to researchers.

Allison Kohler, a graduate student in the Texas A&M University wildlife and fisheries department in College Station, helped make this discovery as well as affirm other flying squirrels do in fact fluoresce pink.

Kohler's undergraduate professor Dr. Jon Martin, associate professor of forestry at Northland College in Wisconsin, was doing an exploratory forest survey with an ultraviolet flashlight in his backyard. Initially, he was looking at different lichens, mosses and plants to see what fluoresced. By chance, a flying squirrel happened to be at his bird feeder. When he saw it under the ultraviolet light, it was hot pink.

A team to investigate this discovery was formed and included Martin, Kohler and two of Martin's colleagues at Northland College: Dr. Paula Anich, associate professor of natural resources, and Dr. Erik Olson, assistant professor of natural resources.

With access to a museum collection at the Minnesota Science Museum, Martin asked Kohler to take the lead on the project and develop a protocol to help further investigate exactly what it was they had found.

"I looked at a ton of different specimens that they had there," Kohler said. "They were stuffed flying squirrels that they had collected over time, and every single one that I saw fluoresced hot pink in some intensity or another."

In order to expand the search, the team went to the Field Museum of Natural History in Chicago and gathered more specimens. In all, they researched over 100 specimens ranging across numerous states, all confirming their "pink theory." They also looked at five additional live specimens.

"We tested all three of the North American flying squirrel species: the Northern flying squirrel, the Southern flying squirrel and the Humboldt's flying squirrel, and all three of them fluoresced," she said.

After comparing the flying species to other squirrels, like the American red squirrel and gray squirrel, the team found that the pink color is unique to the flying squirrel.

The reasons for the squirrels to fluoresce pink is still under investigation, but communication and camouflage are two top contenders for why this might be happening, the team has hypothesized.

"They could be communicating with members of their own species by showing off their fluorescence to each other, or it might be a sort of mating display," Kohler said. "The other hypothesis is that they could be using this fluorescence as an anti-predator trait to communicate with other species, avoiding predation by other species by blending in or dealing with their potentially ultraviolet-saturated environments."

As the research develops, she said, the importance of this find will present itself more clearly. Kohler plans to continue her research while pursuing her master's degree at Texas A&M. Further research will look firmly at the implications of the team's find.

Read more at Science Daily

Retreating snow line reveals organic molecules around young star

The distribution of dust is shown in orange and the distribution of methanol, an organic molecule, is shown in blue.

Astronomers using ALMA have detected various complex organic molecules around the young star V883 Ori. A sudden outburst from this star is releasing molecules from the icy compounds in the planet forming disk. The chemical composition of the disk is similar to that of comets in the modern Solar System. Sensitive ALMA observations enable astronomers to reconstruct the evolution of organic molecules from the birth of the Solar System to the objects we see today.

The research team led by Jeong-Eun Lee (Kyung Hee University, Korea) used the Atacama Large Millimeter/submillimeter Array (ALMA) to detect complex organic molecules including methanol (CH3OH), acetone (CH3COCH3), acetaldehyde (CH3CHO), methyl formate (CH3OCHO), and acetonitrile (CH3CN). This is the first time that acetone was unambiguously detected in a planet forming region or protoplanetary disk.

Various molecules are frozen in ice around micrometer-sized dust particles in protoplanetary disks. V883 Ori's sudden flare-up is heating the disk and sublimating the ice, which releases the molecules into gas. The region in a disk where the temperature reaches the sublimation temperature of the molecules is called the "snow line." The radii of snow lines are about a few astronomical units (au) around normal young stars, however, they are enlarged almost 10 times around bursting stars.

"It is difficult to image a disk on the scale of a few au with current telescopes," said Lee. "However, around an outburst star, ice melts in a wider area of the disk and it is easier to see the distribution of molecules. We are interested in the distribution of complex organic molecules as the building blocks of life."

Ice, including frozen organic molecules, could be closely related to the origin of life on planets. In our Solar System, comets are the focus of attention because of their rich icy compounds. For example, the European Space Agency's legendary comet explorer Rosetta found rich organic chemistry around the comet Churyumov-Gerasimenko. Comets are thought to have been formed in the outer colder region of the proto-Solar System, where the molecules were contained in ice. Probing the chemical composition of ice in protoplanetary disks is directly related to probing the origin of organic molecules in comets, and the origin of the building blocks of life.

Thanks to ALMA's sharp vision and the enlarged snow line due to the flare-up of the star, the astronomers obtained the spatial distribution of methanol and acetaldehyde. The distribution of these molecules has a ring-like structure with a radius of 60 au, which is twice the size of Neptune's orbit. The researchers assume that inside of this ring the molecules are invisible because they are obscured by thick dusty material, and are invisible outside of this radius because they are frozen in ice.

"Since rocky and icy planets are made from solid material, the chemical composition of solids in disks is of special importance. An outburst is a unique chance to investigate fresh sublimates, and thus the composition of solids." says Yuri Aikawa at the University of Tokyo, a member of the research team.

Read more at Science Daily

The Caucasus: Complex interplay of genes and cultures

This is a of the Maykop culture from the burial mound Marinskaya 5.

An international research team, coordinated by the Max Planck Institute for the Science of Human History (MPI-SHH) and the Eurasia Department of the German Archaeological Institute (DAI) in Berlin, is the first to carry out systematic genetic investigations in the Caucasus region. The study, published in Nature Communications, is based on analyses of genome-wide data from 45 individuals in the steppe and mountainous areas of the North Caucasus. The skeletal remains, which are between 6,500 and 3,500 years old, show that the groups living throughout the Caucasus region were genetically similar, despite the harsh mountain terrain, but that there was a sharp genetic boundary to the adjacent steppe areas in the north.

The Caucasus, an area that today includes parts of Russia, Azerbaijan, Armenia, Georgia, Iran and Turkey, is a crucial intersection for the history of Europe, both genetically and culturally. Today it is one of the regions of the world with the highest linguistic diversity, and in the past, populations from the Caucasus were instrumental in shaping the genetic components of today's Europeans. During the Bronze Age, important technological innovations, developed in the Caucasus and beyond, were transported to Europe through this region, such as the first highly effective metal weapons and the wheel and wagon.

"We assume that in the wake of the Neolithic period, sometime before 5,000 BC when a more sedentary lifestyle with domesticated animals and plants was established, populations from the southern Caucasus spread over the mountains to the north and there met with nomadic populations from the Eurasian steppe," says Dr. Wolfgang Haak, group leader for molecular anthropology at the MPI-SHH and leader of the study. "The genetic boundary corresponds in principle to the ecological and geographical regions: the mountains and the steppe. Today, on the other hand, the Caucasus mountains themselves are more of a barrier to gene flow."

Over the centuries, an interaction zone was formed, where the traditions of the Mesopotamian civilization and those of the Caucasus met with the cultures of the steppe. This intertwining is evident in the cultural exchange and transfer of technological and social innovations, as well as the occasional exchange of genes, which the study shows also took place between groups of quite distinct genetic backgrounds.

Cultural contact zone, genetic border region
The skeletal remains studied come from different Bronze Age cultures. The Maykop culture in particular, based on its spectacular grave goods, which had close parallels in the south, was long regarded as a population that had migrated to the North Caucasus from Mesopotamia.

The current paleogenetic study paints a more nuanced picture of mobility during the Bronze Age. People with a distinct southern Caucasus ancestry were already north of the mountain ridges by the 5th millennium BC. It is highly likely that these groups formed the basis for the local Early Bronze Age Maykop culture of the 4th millennium BC. Intriguingly, the Maykop individuals tested are genetically distinct from the groups in the adjacent steppes to the north.

"The genetic results do not support scenarios of large-scale migrations from the south during the Maykop period, or even from the northwest, as was postulated by some archaeologists. These findings have major implications for our understanding of the local development of North Caucasus cultures in the 4th millennium BC," explains Prof. Dr. Dr. h.c. Svend Hansen, Director of the DAI's Eurasia-Department.

By the 3rd millennium BC, pastoralist groups from the steppe were bringing about a fundamental change in the population of Europe. The current study confirms parallel changes in the Caucasus along the southern border of the steppe zone. "During the 3rd and 2nd millennium BC, however, the people living in the Northern Caucasus all shared a similar genetic makeup even though they can be recognized (archaeologically) as different cultural groups," says Sabine Reinhold, co-director of the archaeological team. "Individuals belonging to Yamnaya or Catacomb cultural complexes, according to archaeological analyses of their graves, are genetically indistinguishable from individuals from the North Caucasian culture in the foothills and in the mountains. Local or global cultural attributions were apparently more important than common biological roots."

Subtle gene flow from the west contributed to the formation of early Yamnaya groups

The massive population shifts in the 3rd millennium BC, in connection with the expansion of the groups from the steppe who were part of what is known as the Yamnaya culture, have long been associated with the transfer of significant technological innovations from Mesopotamia to Europe. Recent studies at the DAI's Eurasia department on the spread of early wagons or metal weapons have shown, however, that an intensive exchange between Europe, the Caucasus and Mesopotamia began much earlier. However, can evidence of these technological exchanges also be provided by the genetic interactions revealed in the current study? And if so, in which direction do they point?

The genomes of the Yamnaya individuals from the steppe bordering the Caucasus indeed show subtle genetic traces that are also characteristic of the neighboring farming populations of south-eastern Europe. Detailed analysis now shows that this subtle gene flow cannot be linked to the Maykop population, but must have come from the west.

"These are exciting and surprising findings, which highlight the complexity of the processes that lead to the formation of Bronze Age steppe pastoralist," says Chuan-Chao Wang, population geneticist postdoc at the MPI-SHH and first author of the study, now professor at Xiamen University in China.

Hansen adds, "These subtle genetic traces from the west are indeed remarkable and suggest contact between people in the steppes and western groups, such as the Globular Amphora culture, between the 4th and the 3rd millennium BC."

It appears that the world of the 4th millennium BC was well-connected long before the major expansion of steppe pastoralist and related groups. In this wide-ranging network of contacts, people not only spread and exchanged know-how and technological innovations, but occasionally also exchanged genes, and not only in one direction.

Read more at Science Daily

First discovered fossil feather did not belong to iconic bird Archaeopteryx

The isolated Archaeopteryx feather is the first fossil feather ever discovered. Top image, the feather as it looks today under white light. Middle image, the original drawing from 1862 by Hermann von Meyer. Bottom image, Laser-Stimulated Fluorescence (LSF) showing the halo of the missing quill. Scale bar is 1cm.

A 150-year-old fossil feather mystery has been solved by an international research team including Dr Michael Pittman from the Department of Earth Sciences, The University of Hong Kong. Dr Pittman and his colleagues applied a novel imaging technique, Laser-Stimulated Fluorescence (LSF), revealing the missing quill of the first fossil feather ever discovered, dethroning an icon in the process.

This fossil feather was found in the Solnhofen area of southern Germany in 1861. The isolated feather was used to name the iconic fossil bird Archaeopteryx and was closely identified with its skeletons. Unlike the feather impressions preserved in some Archaeopteryx fossils, the isolated feather is preserved as a dark film. The detailed 1862 description of the feather mentions a rather long quill visible on the fossil, but this is unseen today. Even recent x-ray fluorescence and UV imaging studies did not end the debate of the "missing quill." The original existence of this quill has therefore been debated and it was unclear if the single feather represented a primary, secondary, or primary covert feather.

The results of this study are described in the journal Scientific Reports, and underscore the potential and scientific importance of Laser-Stimulated Fluorescence, which is being developed by Thomas G Kaye of the Foundation for Scientific Advancement, USA and Dr Pittman. "My imaging work with Tom Kaye demonstrates that important discoveries remain to be made even in the most iconic and well-studied fossils," says Dr Pittman.

With the help of the LSF images, the team finally solved the 150-year-old missing quill mystery. The now completely visible feather allowed detailed comparisons with the feather impressions of Archaeopteryx and with living birds. Before this LSF work, the feather was thought to represent a primary covert from Archaeopteryx, but this study shows that it differs from coverts of modern birds by lacking a distinct s-shaped centerline. The team also ruled out that the feather represented a primary, secondary, or tail feather of Archaeopteryx. Instead, the new data indicates that the isolated feather came from an unknown feathered dinosaur and that its attribution to Archaeopteryx was wrong. "It is amazing that this new technique allows us to resolve the 150-year-old mystery of the missing quill," says Daniela Schwarz, co-author in the study and curator for the fossil reptiles and bird collection of the Museum für Naturkunde, Berlin. This discovery also demonstrates that the diversity of feathered dinosaurs was likely higher around the ancient Solnhofen Archipelago than previously thought. "The success of the LSF technique here is sure to lead to more discoveries and applications in other fields. But, you'll have to wait and see what we find next!'' added Tom Kaye, the study's lead author.

From Science Daily

Researcher unearths an ice age in the African desert

Drumlins, hills formed in places once covered by glaciers, were discovered in Namibia by WVU's Graham Andrews.

A field trip to Namibia to study volcanic rocks led to an unexpected discovery by West Virginia University geologists Graham Andrews and Sarah Brown.

While exploring the desert country in southern Africa, they stumbled upon a peculiar land formation -- flat desert scattered with hundreds of long, steep hills. They quickly realized the bumpy landscape was shaped by drumlins, a type of hill often found in places once covered in glaciers, an abnormal characteristic for desert landscapes.

"We quickly realized what we were looking at because we both grew up in areas of the world that had been under glaciers, me in Northern Ireland and Sarah in northern Illinois," said Andrews, an assistant professor of geology. "It's not like anything we see in West Virginia where we're used to flat areas and then gorges and steep-sided valleys down into hollows."

After returning home from the trip, Andrews began researching the origins of the Namibian drumlins, only to learn they had never been studied.

"The last rocks we were shown on the trip are from a time period when southern Africa was covered by ice," Andrews said. "People obviously knew that part of the world had been covered in ice at one time, but no one had ever mentioned anything about how the drumlins formed or that they were even there at all."

Andrews teamed up with WVU geology senior Andy McGrady to use morphometrics, or measurements of shapes, to determine if the drumlins showed any patterns that would reflect regular behaviors as the ice carved them.

While normal glaciers have sequential patterns of growing and melting, they do not move much, Andrews explained. However, they determined that the drumlins featured large grooves, which showed that the ice had to be moving at a fast pace to carve the grooves.

These grooves demonstrated the first evidence of an ice stream in southern Africa in the late Paleozoic Age, which occurred about 300 million years ago.

"The ice carved big, long grooves in the rock as it moved," Andrews said. "It wasn't just that there was ice there, but there was an ice stream. It was an area where the ice was really moving fast."

McGrady used freely available information from Google Earth and Google Maps to measure their length, width and height.

"This work is very important because not much has been published on these glacial features in Namibia," said McGrady, a senior geology student from Hamlin. "It's interesting to think that this was pioneer work in a sense, that this is one of the first papers to cover the characteristics of these features and gives some insight into how they were formed."

Their findings also confirm that southern Africa was located over the South Pole during this period.

"These features provide yet another tie between southern Africa and south America to show they were once joined," Andrews said.

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Much of the surface ocean will shift in color by end of 21st century

A new MIT study finds that over the coming decades climate change will affect the ocean’s color, intensifying its blue regions and its green ones.

Climate change is causing significant changes to phytoplankton in the world's oceans, and a new MIT study finds that over the coming decades these changes will affect the ocean's color, intensifying its blue regions and its green ones. Satellites should detect these changes in hue, providing early warning of wide-scale changes to marine ecosystems.

Writing in Nature Communications, researchers report that they have developed a global model that simulates the growth and interaction of different species of phytoplankton, or algae, and how the mix of species in various locations will change as temperatures rise around the world. The researchers also simulated the way phytoplankton absorb and reflect light, and how the ocean's color changes as global warming affects the makeup of phytoplankton communities.

The researchers ran the model through the end of the 21st century and found that, by the year 2100, more than 50 percent of the world's oceans will shift in color, due to climate change.

The study suggests that blue regions, such as the subtropics, will become even more blue, reflecting even less phytoplankton -- and life in general -- in those waters, compared with today. Some regions that are greener today, such as near the poles, may turn even deeper green, as warmer temperatures brew up larger blooms of more diverse phytoplankton.

"The model suggests the changes won't appear huge to the naked eye, and the ocean will still look like it has blue regions in the subtropics and greener regions near the equator and poles," says lead author Stephanie Dutkiewicz, a principal research scientist at MIT's Department of Earth, Atmospheric, and Planetary Sciences and the Joint Program on the Science and Policy of Global Change. "That basic pattern will still be there. But it'll be enough different that it will affect the rest of the food web that phytoplankton supports."

Dutkiewicz's co-authors include Oliver Jahn of MIT, Anna Hickman of the University of Southhampton, Stephanie Henson of the National Oceanography Centre Southampton, Claudie Beaulieu of the University of California at Santa Cruz, and Erwan Monier of the University of California at Davis.

Chlorophyll count

The ocean's color depends on how sunlight interacts with whatever is in the water. Water molecules alone absorb almost all sunlight except for the blue part of the spectrum, which is reflected back out. Hence, relatively barren open-ocean regions appear as deep blue from space. If there are any organisms in the ocean, they can absorb and reflect different wavelengths of light, depending on their individual properties.

Phytoplankton, for instance, contain chlorophyll, a pigment which absorbs mostly in the blue portions of sunlight to produce carbon for photosynthesis, and less in the green portions. As a result, more green light is reflected back out of the ocean, giving algae-rich regions a greenish hue.

Since the late 1990s, satellites have taken continuous measurements of the ocean's color. Scientists have used these measurements to derive the amount of chlorophyll, and by extension, phytoplankton, in a given ocean region. But Dutkiewicz says chlorophyll doesn't necessarily have reflect the sensitive signal of climate change. Any significant swings in chlorophyll could very well be due to global warming, but they could also be due to "natural variability" -- normal, periodic upticks in chlorophyll due to natural, weather-related phenomena.

"An El Niño or La Niña event will throw up a very large change in chlorophyll because it's changing the amount of nutrients that are coming into the system," Dutkiewicz says. "Because of these big, natural changes that happen every few years, it's hard to see if things are changing due to climate change, if you're just looking at chlorophyll."

Modeling ocean light

Instead of looking to derived estimates of chlorophyll, the team wondered whether they could see a clear signal of climate change's effect on phytoplankton by looking at satellite measurements of reflected light alone.

The group tweaked a computer model that it has used in the past to predict phytoplankton changes with rising temperatures and ocean acidification. This model takes information about phytoplankton, such as what they consume and how they grow, and incorporates this information into a physical model that simulates the ocean's currents and mixing.

This time around, the researchers added a new element to the model, that has not been included in other ocean modeling techniques: the ability to estimate the specific wavelengths of light that are absorbed and reflected by the ocean, depending on the amount and type of organisms in a given region.

"Sunlight will come into the ocean, and anything that's in the ocean will absorb it, like chlorophyll," Dutkiewicz says. "Other things will absorb or scatter it, like something with a hard shell. So it's a complicated process, how light is reflected back out of the ocean to give it its color."

When the group compared results of their model to actual measurements of reflected light that satellites had taken in the past, they found the two agreed well enough that the model could be used to predict the ocean's color as environmental conditions change in the future.

"The nice thing about this model is, we can use it as a laboratory, a place where we can experiment, to see how our planet is going to change," Dutkiewicz says.

A signal in blues and greens

As the researchers cranked up global temperatures in the model, by up to 3 degrees Celsius by 2100 -- what most scientists predict will occur under a business-as-usual scenario of relatively no action to reduce greenhouse gases -- they found that wavelengths of light in the blue/green waveband responded the fastest.

What's more, Dutkiewicz observed that this blue/green waveband showed a very clear signal, or shift, due specifically to climate change, taking place much earlier than what scientists have previously found when they looked to chlorophyll, which they projected would exhibit a climate-driven change by 2055.

"Chlorophyll is changing, but you can't really see it because of its incredible natural variability," Dutkiewicz says. "But you can see a significant, climate-related shift in some of these wavebands, in the signal being sent out to the satellites. So that's where we should be looking in satellite measurements, for a real signal of change."

According to their model, climate change is already changing the makeup of phytoplankton, and by extension, the color of the oceans. By the end of the century, our blue planet may look visibly altered.

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