Whales only recently evolved into giants when changing ice, oceans concentrated prey

The blue whale, which uses baleen to filter its prey from ocean water and can reach lengths of over 100 feet, is the largest vertebrate animal that has ever lived. On the list of the planet's most massive living creatures, the blue whale shares the top ranks with most other species of baleen whales alive today. According to new research from scientists at the Smithsonian's National Museum of Natural History, however, it was only recently in whale's evolutionary past that they became so enormous. In a study reported May 24 in Proceedings of the Royal Society B, Nicholas Pyenson, the museum's curator of fossil marine mammals, and collaborators Graham Slater at the University of Chicago and Jeremy Goldbogen at Stanford University, traced the evolution of whale size through more than 30 million years of history and found that very large whales appeared along several branches of the family tree about 2 to 3 million years ago. Increasing ice sheets in the Northern Hemisphere during this period likely altered the way whales' food was distributed in the oceans and enhanced the benefits of a large body size, the scientists say. How and why whales got so big has remained a mystery until now, in part because of the challenges of interpreting an incomplete fossil record. "We haven't had the right data," Pyenson said. "How do you measure the total length of a whale that's represented by a chunk of fossil?" Recently, however, Pyenson established that the width of a whale's skull is a good indicator of its overall body size. With that advance, the time was right to address the long-standing question. The Smithsonian holds the largest and richest skull collections for both living and extinct baleen whales, and the museum was one of the few places that housed a collection that could provide the raw data needed to examine the evolutionary relationships between whales of different sizes. Pyenson and his colleagues measured a wide range of fossil skulls from the National Museum of Natural History's collections and used those measurements, along with published data on additional specimens, to estimate the length of 63 extinct whale species. The fossils included in the analysis represented species dating back to the earliest baleen whales, which lived more than 30 million years ago. The team used the fossil data, together with data on 13 species of modern whales, to examine the evolutionary relationships between whales of different sizes. Their data clearly showed that the large whales that exist today were not present for most of whales' history. "We live in a time of giants," Goldbogen said. "Baleen whales have never been this big, ever." The research team traced the discrepancy back to a shift in the way body size evolved that occurred about 4.5 million years ago. Not only did whales with bodies longer than 10 meters (approximately 33 feet) begin to evolve around this time, but smaller species of whales also began to disappear. Pyenson notes that larger whales appeared in several different lineages around the same time, suggesting that massive size was somehow advantageous during that timeframe. "We might imagine that whales just gradually got bigger over time, as if by chance, and perhaps that could explain how these whales became so massive," said Slater, a former Peter Buck postdoctoral fellow at the museum. "But our analyses show that this idea doesn't hold up -- the only way that you can explain baleen whales becoming the giants they are today is if something changed in the recent past that created an incentive to be a giant and made it disadvantageous to be small." This evolutionary shift, which took place at the beginning of the Ice Ages, corresponds to climatic changes that would have reshaped whales' food supply in the world's oceans. Before ice sheets began to cover the Northern Hemisphere, food resources would have been fairly evenly distributed throughout the oceans, Pyenson said. But when glaciation began, run off from the new ice caps would have washed nutrients into coastal waters at certain times of the year, seasonally boosting food supplies. At the time of this transition, baleen whales, which filter small prey, like krill, out of seawater, were well equipped to take advantage of these dense patches of food. Goldbogen, whose studies of modern whale foraging behavior have demonstrated that filter-feeding is particularly efficient when whales have access to very dense aggregations of prey, said the foraging strategy becomes even more efficient as body size increases. What's more, large whales can migrate thousands of miles to take advantage of seasonally abundant food supplies. So, the scientists said, baleen whales' filter-feeding systems, which evolved about 30 million years ago, appear to have set the stage for major size increases once rich sources of prey became concentrated in particular locations and times of year. "An animal's size determines so much about its ecological role," Pyenson said. "Our research sheds light on why today's oceans and climate can support Earth's most massive vertebrates. But today's oceans and climate are changing at geological scales in the course of human lifetimes. With these rapid changes, does the ocean have the capacity to sustain several billion people and the world's largest whales? The clues to answer this question lie in our ability to learn from Earth's deep past -- the crucible of our present world -- embedded in the fossil record." Funding for this study was provided by the Smithsonian's Remington Kellogg Fund and with support from the Basis Foundation. Story Source: Materials provided by Smithsonian. 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New technology generates power from polluted air

Researchers from the University of Antwerp and KU Leuven (University of Leuven), Belgium, have succeeded in developing a process that purifies air and, at the same time, generates power. The device must only be exposed to light in order to function. "We use a small device with two rooms separated by a membrane," explains professor Sammy Verbruggen (UAntwerp/KU Leuven). "Air is purified on one side, while on the other side hydrogen gas is produced from a part of the degradation products. This hydrogen gas can be stored and used later as fuel, as is already being done in some hydrogen buses, for example. " In this way, the researchers respond to two major social needs: clean air and alternative energy production. The heart of the solution lies at the membrane level, where the researchers use specific nanomaterials. "These catalysts are capable of producing hydrogen gas and breaking down air pollution," explains professor Verbruggen. "In the past, these cells were mostly used to extract hydrogen from water. We have now discovered that this is also possible, and even more efficient, with polluted air." It seems to be a complex process, but it is not: the device must only be exposed to light. The researchers' goal is to be able to use sunlight, as the processes underlying the technology are similar to those found in solar panels. The difference here is that electricity is not generated directly, but rather that air is purified while the generated power is stored as hydrogen gas. "We are currently working on a scale of only a few square centimetres. At a later stage, we would like to scale up our technology to make the process industrially applicable. We are also working on improving our materials so we can use sunlight more efficiently to trigger the reactions. "   Story Source:   Materials provided by KU Leuven. Note: Content may be edited for style and length.

Long-sought pattern of ancient light detected

The journey of light from the very early universe to modern telescopes is long and winding. The ancient light traveled billions of years to reach us, and along the way, its path was distorted by the pull of matter, leading to a twisted light pattern. This twisted pattern of light, called B-modes, has at last been detected. The discovery, which will lead to better maps of matter across our universe, was made using the National Science Foundation's South Pole Telescope, with help from the Herschel space observatory. Scientists have long predicted two types of B-modes: the ones that were recently found were generated a few billion years into our universe's existence (it is presently 13.8 billion years old). The others, called primordial, are theorized to have been produced when the universe was a newborn baby, fractions of a second after its birth in the Big Bang. "This latest discovery is a good checkpoint on our way to the measurement of primordial B-modes," said Duncan Hanson of McGill University in Montreal, Canada, lead author of the new report published Sept. 30 in the online edition of Physical Review Letters. The elusive primordial B-modes may be imprinted with clues about how our universe was born. Scientists are currently combing through data from the Planck mission in search of them. Both Herschel and Planck are European Space Agency missions, with important NASA contributions. The oldest light we see around us today, called the cosmic microwave background, harkens back to a time just hundreds of millions of years after the universe was created. Planck recently produced the best-ever full-sky map of this light, revealing new details about of our cosmos' age, contents and origins. A fraction of this ancient light is polarized, a process that causes light waves to vibrate in the same plane. The same phenomenon occurs when sunlight reflects off lakes, or particles in our atmosphere. On Earth, special sunglasses can isolate this polarized light, reducing glare. The B-modes are a twisted pattern of polarized light. In the new study, the scientists were on a hunt for the kind of polarized light spawned by matter in a process called gravitational lensing, where the gravitational pull from knots of matter distorts the path of light. The signals are extremely faint, so Hanson and colleagues used Herschel's infrared map of matter to get a better idea of where to look. The researchers then spotted the signals with the South Pole Telescope, making the first-ever detection of B-modes. This is an important step for better mapping how matter, both normal and dark, is distributed throughout our universe. Clumps of matter in the early universe are the seeds of galaxies like our Milky Way. Astronomers are eager to detect primordial B-modes next. These polarization signals, from billions of years ago, would be much brighter on larger scales, which an all-sky mission like Planck is better able to see. "These beautiful measurements from the South Pole Telescope and Herschel strengthen our confidence in our current model of the universe," said Olivier Doré, a member of the U.S. Planck science team at NASA's Jet Propulsion Laboratory, Pasadena, Calif. "However, this model does not tell us how big the primordial signal itself should be. We are thus really exploring with excitement a new territory here, and a potentially very, very old one." Read the European Space Agency feature about this work at http://www.esa.int/Our_Activities/Space_Science/Herschel/Herschel_helps_find_elusive_signals_from_the_early_Universe. Herschel is a European Space Agency mission, with science instruments provided by consortia of European institutes and with important participation by NASA. NASA's Herschel Project Office is based at NASA's Jet Propulsion Laboratory, Pasadena, Calif. JPL contributed mission-enabling technology for two of Herschel's three science instruments. The NASA Herschel Science Center, part of the Infrared Processing and Analysis Center at the California Institute of Technology in Pasadena, supports the United States astronomical community. Caltech manages JPL for NASA. More information is online at http://www.herschel.caltech.edu, http://www.nasa.gov/herschel and http://www.esa.int/SPECIALS/Herschel. Planck is a European Space Agency mission, with significant participation from NASA. NASA's Planck Project Office is based at JPL. JPL contributed mission-enabling technology for both of Planck's science instruments. European, Canadian and U.S. Planck scientists work together to analyze the Planck data. More information is online at http://www.nasa.gov/planck and http://www.esa.int/planck.   Story Source:   Materials provided by NASA/Jet Propulsion Laboratory. Note: Content may be edited for style and length.

Graphene on silicon carbide can store energy

 By introducing defects into the perfect surface of graphene on silicon carbide, researchers at Linköping University in Sweden have increased the capacity of the material to store electrical charge. This result, which has been published in the scientific journal Electrochimica Acta, increases our knowledge of how this ultrathin material can be used. The thinnest material ever produced, graphene, consists of a single layer of carbon atoms. They form a chicken-wire structure one atom thick, with unique properties. It is around 200 times stronger than steel, and highly flexible. It is transparent, but gases and liquids cannot pass through it. In addition, it is an excellent conductor of electricity. There are many ideas about how this nanomaterial can be used, and research into future applications is intense. "Graphene is fascinating, but extremely difficult to study," says Mikhail Vagin, principal research engineer at the Department of Science and Technology and the Department of Physics, Chemistry and Biology at Linköping University. One of the factors contributing to the difficulty in understanding the properties of graphene is that it is what is known as an "anisotropic" material. This means that its properties when measured on the plane surface of the carbon atom layer differ from those measured at the edges. Furthermore, attempts to understand the behaviour of graphene at the atomic level are complicated by the fact that it can be produced in several ways. The properties of graphene in small flakes, which have many edges, differ in several ways from those of graphene produced as sheets with an area around 1 cm2. The researchers who carried out the study used graphene created on a crystal of silicon carbide by a method developed at Linköping University. When silicon carbide is heated to 2000 °C, silicon atoms on the surface moves to the vapor phase and only the carbon atoms remain. The graphene does not react easily with its surroundings due to the high quality of the graphene layer and its innate inertness, while applications often rely on controlled interaction between the material and the surroundings, like gas molecules. An on-going discussion among researchers in the field is whether it is possible to activate the graphene on the flat surface or whether it is necessary to have edges. The LiU researchers investigated what happens when defects in the surface are introduced in a controlled manner, and in this way attempted to understand in more detail how the properties of graphene are related to its structure. "An electrochemical process known as 'anodising' breaks down the graphene layer such that more edges are created. We measured the properties of anodised graphene and discovered that the capacity of the material to store electricity was quite high," says Mikhail Vagin. More work is necessary before the new knowledge can be used, and to produce the same effect at a larger scale. The scientists plan to follow up the research in several ways. "Graphene on silicon carbide can be made in larger areas than other types of graphene. If we can change the properties of the material in a controlled manner, it may be possible to tailor the surface for other functions. It may be possible, for example, to create a sensor that has its own built-in battery," says Mikael Syväjärvi, principal research engineer at the Department of Physics, Chemistry and Biology and co-author of the article. He is one of the founders of a company, Graphensic AB, that works with commercial applications of graphene on silicon carbide.   Story Source: Materials provided by Linköping Universitet. Note: Content may be edited for style and length.

New object near supermassive black hole in famous galaxy

Pointing the Very Large Array (VLA) at a famous galaxy for the first time in two decades, a team of astronomers got a big surprise, finding that a bright new object had appeared near the galaxy's core. The object, the scientists concluded, is either a very rare type of supernova explosion or, more likely, an outburst from a second supermassive black hole closely orbiting the galaxy's primary, central supermassive black hole. The astronomers observed Cygnus A, a well-known and often-studied galaxy discovered by radio-astronomy pioneer Grote Reber in 1939. The radio discovery was matched to a visible-light image in 1951, and the galaxy, some 800 million light-years from Earth, was an early target of the VLA after its completion in the early 1980s. Detailed images from the VLA published in 1984 produced major advances in scientists' understanding of the superfast "jets" of subatomic particles propelled into intergalactic space by the gravitational energy of supermassive black holes at the cores of galaxies. "This new object may have much to tell us about the history of this galaxy," said Daniel Perley, of the Astrophysics Research Institute of Liverpool John Moores University in the U.K., lead author of a paper in the Astrophysical Journal announcing the discovery. "The VLA images of Cygnus A from the 1980s marked the state of the observational capability at that time," said Rick Perley, of the National Radio Astronomy Observatory (NRAO). "Because of that, we didn't look at Cygnus A again until 1996, when new VLA electronics had provided a new range of radio frequencies for our observations." The new object does not appear in the images made then. "However, the VLA's upgrade that was completed in 2012 made it a much more powerful telescope, so we wanted to have a look at Cygnus A using the VLA's new capabilities," Perley said. Daniel and Rick Perley, along with Vivek Dhawan, and Chris Carilli, both of NRAO, began the new observations in 2015, and continued them in 2016. "To our surprise, we found a prominent new feature near the galaxy's nucleus that did not appear in any previous published images. This new feature is bright enough that we definitely would have seen it in the earlier images if nothing had changed," said Rick Perley. "That means it must have turned on sometime between 1996 and now," he added. The scientists then observed Cygnus A with the Very Long Baseline Array (VLBA) in November of 2016, clearly detecting the new object. A faint infrared object also is seen at the same location in Hubble Space Telescope and Keck observations, originally made between 1994 and 2002. The infrared astronomers, from Lawrence Livermore National Laboratory, had attributed the object to a dense group of stars, but the dramatic radio brightening is forcing a new analysis. What is the new object? Based on its characteristics, the astronomers concluded it must be either a supernova explosion or an outburst from a second supermassive black hole near the galaxy's center. While they want to watch the object's future behavior to make sure, they pointed out that the object has remained too bright for too long to be consistent with any known type of supernova. "Because of this extraordinary brightness, we consider the supernova explanation unlikely," Dhawan said. While the new object definitely is separate from Cygnus A's central supermassive black hole, by about 1500 light-years, it has many of the characteristics of a supermassive black hole that is rapidly feeding on surrounding material. "We think we've found a second supermassive black hole in this galaxy, indicating that it has merged with another galaxy in the astronomically-recent past," Carilli said. "These two would be one of the closest pairs of supermassive black holes ever discovered, likely themselves to merge in the future." The astronomers suggested that the second black hole has become visible to the VLA in recent years because it has encountered a new source of material to devour. That material, they said, could either be gas disrupted by the galaxies' merger or a star that passed close enough to the secondary black hole to be shredded by its powerful gravity. "Further observations will help us resolve some of these questions. In addition, if this is a secondary black hole, we may be able to find others in similar galaxies," Daniel Perley said. Rick Perley was one of the astronomers who made the original Cygnus A observations with the VLA in the 1980s. Daniel Perley is his son, now also a research astronomer. "Daniel was only two years old when I first observed Cygnus A with the VLA," Rick said. As a high school student in Socorro, New Mexico, Daniel used VLA data for an award-winning science fair project that took him to the international level of competition, then went on to earn a doctoral degree in astronomy.   Story Source:   Materials provided by National Radio Astronomy Observatory. Note: Content may be edited for style and length

Water is surprisingly ordered on the nanoscale

Nanometric-sized water drops are everywhere -- in the air as droplets or aerosols, in our bodies as medication, and in Earth, within rocks and oil fields. To understand the behavior of these drops, it is necessary to know how they interact with their hydrophobic environment. This interaction takes places at the curved droplet interface, a sub-nanometric region that surrounds the small pocket of water. Researchers from EPFL, in collaboration with the institute AMOLF in the Netherlands, were able to observe what was going on in this particular region. They discovered that molecules on the surface of the drops were much more ordered than expected. Their surprising results have been published in Nature Communications. They pave the way to a better understanding of atmospheric, biological and geological processes. Unique perspective on miniscule droplets At EPFL, Sylvie Roke, director of the Julia Jacobi Chair of Photomedicine-Laboratory for Fundamental BioPhotonics, has developed a unique method for examining the surface of these droplets that are as thick as one thousandth of a hair, with a volume of an attoliter (18 zeros behind the comma). "The method involves overlapping ultrashort laser pulses in a mixture of water droplets in liquid oil and detecting photons that are scattered only from the interface," explains Roke. "These photons have the sum frequency of the incoming photons and are thus of a different color. With this newly generated color we can know the structure of the only the interface." Hydrogen bonding as strong as in ice The surface of the water droplets turns out to be much more ordered than that of normal water and is comparable to super cooled (liquid < 0 °C water) water in which the water molecules have very strong hydrogen bond interactions. In ice, these interactions lead to a stable tetrahedral surrounding of each water molecule. Surprisingly, this type of structure was found on the surface of the droplets even at the room temperature -- 50 °C above were it would normally appear. Chemical processes This research provides valuable insight into the properties of nanometric water drops. "The chemical properties of these drops depend on how the water molecules are organized on the surface, so it's really important to understand what's going on there," explained Roke. Further research could target the surface properties of water droplets with adding salt, a more realistic model of marine aerosols that consist of salty water surrounded by a hydrophobic environment. Salt may either enhance the water network or reduce its strength. "Or, it may not do anything at all. Given the surprising results found here, we can only speculate," says Roke. Story Source: Materials provided by Ecole Polytechnique Fédérale de Lausanne. Note: Content may be edited for style and length.

A recipe for concrete that can withstand road salt deterioration

Road salt, used in copious helpings each winter to protect them from ice and preserve safe driving conditions, is slowly degrading the concrete they're made of. Engineers have known for some time that calcium chloride salt, commonly used as deicer, reacts with the calcium hydroxide in concrete to form a chemical byproduct that causes roadways to crumble. A civil engineer from Drexel University is working on a new recipe for concrete, using cast-off products from furnaces, that can hold its own against the forces of chemical erosion. More than 900,000 tons of deicing salt is used each winter in Pennsylvania alone. While winters in the Northeast put pressure on departments of transportation to keep roads clear and deicer is an effective part of that process, it also contributes to the thousands of miles of roads that need to be patched and repaired each year. Yaghoob Farnam, PhD, an assistant professor in Drexel's College of Engineering and director of the Advanced and Sustainable Infrastructure Materials Research Group, is looking for a solution to this problem in the recipe for concrete. Farnam created a method for using fly ash, slag and silica fume -- leftovers from coal furnaces and the smelting process -- in a new concrete mix that is more durable because it doesn't react with road salt. He recently published his findings in the journal of Cement and Concrete Composites. "Many departments of transportation have reduced the amount of calcium chloride they use to melt ice and snow, even though it is very efficient at doing so -- because it has also been found to be very destructive," Farnam said. "This research proves that by using alternate cementitious materials to make concrete, they can avoid the destructive chemical reaction and continue to use calcium chloride." The goal of Farnam's work is to produce a concrete mix as strong as the ones currently used to build roads, that contains less calcium hydroxide -- the ingredient that reacts with road salt to form a compound called calcium oxychloride. This chemical tends to expand when it is formed, and when that reaction happens in the pores of cement it can cause degradation and cracking. Farnam's research led him to the conclusion that these "supplementary cement materials" could be substituted into the mix with a better result when they come in contact with calcium chloride deicing salt. "There is a great push to use these power industry byproducts because they take up space and some of them can be harmful to the environment," Farnam said. "We believed that portions of the byproducts such as fly ash, slag and silica fume could be used to make concrete that is both durable -- and cheaper, because it uses recycled materials." To test his theory, Farman's lab created cement samples using varying amounts of fly ash, silica fume and slag and compared them to samples of "ordinary Portland cement" -- the most common type used in roads. His findings confirmed his hypothesis, namely that the samples containing more cement substitute materials did not produce as much calcium oxychloride. An examination of the ordinary Portland cement samples, via acoustic emissions, x-rays and microscopy, revealed damage after just eight days of exposure due to the formation of calcium oxychloride while samples with proper amount of fly ash, silica fume and slag did not show damage during the testing period. The study also revealed that higher concentrations of calcium chloride produce more calcium oxychloride when it reacts with concrete. So, theoretically, using lower concentrations of calcium chloride on roads could help extend their life, but it would also make it less effective as a deicing agent. "An additional concern is that calcium oxychloride can form even if the concrete is not undergoing a freeze-thaw cycle. It is a chemical reaction that can happen at room temperature, so it can take place when the roads are pre-salted even if ice doesn't form. And as the salts remain on the surface after a snowstorm the reaction will continue to degrade the road, so it is vitally important to minimize this reaction in order to preserve the infrastructure," Farnam said. Farnam's lab will continue to search for ways to improve the materials we use in our infrastructure. They are currently pursuing a method for creating a protective layer on the surface of concrete by using bacteria that can prevent calcium oxychloride formation. Story Source: Materials provided by Drexel University. Note: Content may be edited for style and length.

Gas gives laser-induced graphene super properties

Rice University scientists who invented laser-induced graphene (LIG) for applications like supercapacitors have now figured out a way to make the spongy graphene either superhydrophobic or superhydrophilic. And it's a gas. Until recently, the Rice lab of James Tour made LIG only in open air, using a laser to burn part of the way through a flexible polyimide sheet to get interconnected flakes of graphene. But putting the polymer in a closed environment with various gases changed the product's properties. Forming LIG in argon or hydrogen makes it superhydrophobic, or water-avoiding, a property highly valued for separating water from oil or de-icing surfaces. Forming it in oxygen or air makes it superhydrophilic, or water-attracting, and that makes it highly soluble. The research at Rice and at Ben-Gurion University in Israel is the subject of a paper in Advanced Materials. "Labs could make graphene either hydrophobic or hydrophilic before, but it involved multiple steps of either wet-chemical or chemical vapor deposition processes," Tour said. "We're doing this in one step with relatively cheap materials in a homemade atmosphere chamber." The labs got a bonus when they discovered that fabricating LIG in oxygen increased the number of defects -- 5- and 7-atom rings -- in the graphene flakes, improving its capacitance and its performance when used as an electrode material for microsupercapacitors. Changes in the chemical content of the gas and even changes in the direction of the laser raster pattern altered the material, leading the researchers to believe LIG's hydrophobic or -philic properties could be tuned. They also discovered when they scraped graphene off of a hydrophilic sheet of polymer and turned it into a film, the result was hydrophobic instead. "That leads us to believe the surface orientation of LIG's flakes have a lot to do with how it reacts with water," Tour said. "If the edges are more exposed, it appears to be hydrophilic; if the basal planes are more exposed, their hydrophobic properties take over." What makes a material "super" in either direction is the angle at which it encounters water. A material with a contact angle of 0 degrees is considered superhydrophilic. In this case, water would lay on the material in a puddle. If the angle is 150 degrees or more, that's superhydrophobic; the angle is determined by how much the water beads. (An angle of 180 degrees would be a sphere sitting perfectly on top of LIG.) The discovery that surface type and chemistry affect LIG should also allow some leeway in adjusting the material's properties, Tour said. In fact, when they used a sulfur/fluorine gas to make it, they raised LIG's superhydrophobicity to 160 degrees. Story Source: Materials provided by Rice University. Original written by Mike Williams. Note: Content may be edited for style and length.
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