Feb 25, 2017

Where do flowers come from? Shedding light on Darwin’s 'abominable mystery'

Close-up on male cones, on which pollen can be seen.
The mystery that is the origin of flowering plants has been partially solved thanks to a team from the Laboratoire de Physiologie Cellulaire et Végétale (CNRS/Inra/CEA/Université Grenoble Alpes), in collaboration with the Reproduction et Développement des Plantes laboratory (CNRS/ENS Lyon/Inra/Université Claude Bernard Lyon 1) and Kew Gardens (UK). Their discovery, published in the journal New Phytologist on February 24, 2017, sheds light on a question that much intrigued Darwin: the appearance of a structure as complex as the flower over the course of evolution.

Terrestrial flora is today dominated by flowering plants. They provide our food and contribute color to the plant world. But they have not always existed. While plants colonized the land over 400 million years ago, flowering plants appeared only 150 million years ago. They were directly preceded by a group known as the gymnosperms, whose mode of reproduction is more rudimentary and whose modern-day representatives include conifers.

Darwin long pondered the origin and rapid diversification of flowering plants, describing them as an "abominable mystery." In comparison with gymnosperms, which possess rather rudimentary male and female cones (like the pine cone), flowering plants present several innovations: the flower contains the male organs (stamens) and the female organs (pistil), surrounded by petals and sepals, while the ovules, instead of being naked, are protected within the pistil.

How was nature able to invent the flower, a structure so different from that of cones? The team led by François Parcy, a CNRS senior researcher at the Cell and Plant Physiology Laboratory (CNRS/Inra/CEA/Université Grenoble Alpes), has just provided part of the answer. To do so, the researchers studied a rather original gymnosperm called Welwitschia mirabilis. This plant, which can live for more than a millennium, grows in the extreme conditions of the deserts of Namibia and Angola, and, like other gymnosperms, possesses separate male and female cones. What is exceptional is that the male cones possess a few sterile ovules and nectar, which indicates a failed attempt to invent the bisexual flower. Yet, in this plant (as well as in certain conifers), the researchers found genes similar to those responsible for the formation of flowers, and which are organized according to the same hierarchy (with the activation of one gene activating the next gene, and so on)!

The fact that a similar gene cascade has been found in flowering plants and their gymnosperm cousins indicates that this is inherited from their common ancestor. This mechanism did not have to be invented at the time of the origins of the flower: it was simply inherited and reused by the plant, a process that is often at work in evolution.

Read more at Science Daily

The Search for Life in the Universe Just Got a Lot More Interesting

The discovery of seven Earth-sized worlds orbiting a star 40 light-years away is certainly exciting news for exoplanet hunters and enthusiasts. But with three of these planets in the habitable zone of the cool, dwarf star TRAPPIST-1, this new discovery is definitely increasing our odds of finding other life in our galaxy.

Experts say that finding multiple planets in the "Goldilocks zone" of a star is a great discovery because there can be even more potentially habitable planets per star than originally thought.

"Finding several potential habitable planets per star is generally great news for our search for life," Lisa Kaltenegger, director of the Carl Sagan Institute at Cornell University, said in an email. "In our own solar system, we have two planets in the Habitable Zone (Earth and Mars), and this new system has three planets in the Habitable Zone. So far, it holds the record for number of rocky planets in the HZ."

Even though these planets are Earth-sized, that doesn't mean they are Earth-like. But several research teams are planning follow-up observations, so that means the fun is just beginning.

"I think the detection of the new planets in the TRAPPIST-1 system is a groundbreaking discovery," said Thomas Barclay, director of the Kepler/K2 mission Guest Observer program. "This has given us an example of temperate planets in our own backyard that we will be able to study in the coming years. So many opportunities to learn new things in one planetary systems is extremely compelling. Following along with the study of these planets is going to be thrilling. Within a few years this planetary system will be the second best studied, after our own solar system."

Sara Seager, a planet hunter and professor of planetary science and physics at Massachusetts Institute of Technology, said that since the discovery of TRAPPIST-1 astronomers have used every telescope available to conduct follow-up observations. The Spitzer Space Telescope was instrumental in making confirmation studies of these worlds, which is especially interesting since Spitzer was never designed to observe exoplanets.

The Hubble Space Telescope is screening the six innermost planets looking for evidence of atmospheres. These observations, in the infrared and performed with the Wide Field Camera 3, will provide further information about the nature of the planets. In addition, Hubble's Space Telescope Imaging Spectrograph already observed the two innermost planets in the ultraviolet to determine the amount of irradiation they receive from their parent star.

But the best observatories for finding out more about these worlds — especially for determining their habitability — have yet to be launched.

"Looking for atmospheric bio-signatures — meaning the presence of ozone that would shield the surface and indicate biology in combination with a reduced gas like methane — could be detected with the James Webb Space Telescope, which will launch next year," Kaltenegger said.

This chart shows, on the top row, artist concepts of the seven planets of TRAPPIST-1 with their orbital periods, distances from their star, radii and masses as compared to those of Earth.
JSWT's study of atmospheres to assess the greenhouse gas content can also provide information about a planet's surface.

Another upcoming mission is the Transiting Exoplanet Survey Satellite that will attempt to detect small planets with bright host stars in our nearby solar neighborhood, so that detailed characterizations of the planets and their atmospheres can be performed.

"This new discovery is just a taster for planets that the TESS mission will find, which is due for launch in March 2018," Barclay said. "The goal of this is to find new worlds that we can study with future telescopes like JWST. I hope that within a decade we will have a clear picture of the atmospheric chemistry of planets like those around TRAPPIST-1."

 The search for life around the star, Barclay said, requires the use of transit spectroscopy.

"We use starlight shining through the atmosphere of a planet to tell us about the chemical makeup of that planet," he explained. "What we are looking for is telltale signs of chemicals we think are evidence of biological processes. Examples might be methane, oxygen and carbon dioxide. In the near future, observations from the James Webb Space Telescope will be key to this discovery."

Barclay added that up until now almost all the planets we know about are not actually seen, but astronomers use proxy observations, like transits, to understand their characteristics. But that will change with new observatories and techniques.

"In the future we want to directly image earth-like planets," he said. "This involves using technology called coronagraphs to block out the starlight and leave only the light from the planet. Future NASA space experiments like the Wide Field Infrared Survey Telescope mission will allow us to image planets like Earth."

WFIRST is expected to launch in the mid-2020's.

Read more at Discovery News

Feb 24, 2017

Neural networks promise sharpest ever images

The frames here show an example of an original galaxy image (left), the same image deliberately degraded (second from left), the image after recovery with the neural net (second from right), and the image processed with deconvolution, the best existing technique (right).
Telescopes, the workhorse instruments of astronomy, are limited by the size of the mirror or lens they use. Using 'neural nets', a form of artificial intelligence, a group of Swiss researchers now have a way to push past that limit, offering scientists the prospect of the sharpest ever images in optical astronomy. The new work appears in a paper in Monthly Notices of the Royal Astronomical Society.

The diameter of its lens or mirror, the so-called aperture, fundamentally limits any telescope. In simple terms, the bigger the mirror or lens, the more light it gathers, allowing astronomers to detect fainter objects, and to observe them more clearly. A statistical concept known as 'Nyquist sampling theorem' describes the resolution limit, and hence how much detail can be seen.

The Swiss study, led by Prof Kevin Schawinski of ETH Zurich, uses the latest in machine learning technology to challenge this limit. They teach a neural network, a computational approach that simulates the neurons in a brain, what galaxies look like, and then ask it to automatically recover a blurred image and turn it into a sharp one. Just like a human, the neural net needs examples - in this case a blurred and a sharp image of the same galaxy - to learn the technique.

Their system uses two neural nets competing with each other, an emerging approach popular with the machine learning research community called a "generative adversarial network", or GAN. The whole teaching programme took just a few hours on a high performance computer.

The trained neural nets were able to recognise and reconstruct features that the telescope could not resolve - such as star-forming regions, bars and dust lanes in galaxies. The scientists checked it against the original high-resolution image to test its performance, finding it better able to recover features than anything used to date, including the 'deconvolution' approach used to improve the images made in the early years of the Hubble Space Telescope.

Schawinski sees this as a big step forward: "We can start by going back to sky surveys made with telescopes over many years, see more detail than ever before, and for example learn more about the structure of galaxies. There is no reason why we can't then apply this technique to the deepest images from Hubble, and the coming James Webb Space Telescope, to learn more about the earliest structures in the Universe."

Professor Ce Zhang, the collaborator from computer science, also sees great potential: "The massive amount of astronomical data is always fascinating to computer scientists. But, when techniques such as machine learning emerge, astrophysics also provides a great test bed for tackling a fundamental computational question - how do we integrate and take advantage of the knowledge that humans have accumulated over thousands of years, using a machine learning system? We hope our collaboration with Kevin can also shed light on this question."

Read more at Science Daily

From rocks in Colorado, evidence of a 'chaotic solar system'

The layer cake of sedimentary rock near Big Bend, Texas, shows the alternating layers of shale and limestone characteristic of the rock laid down at the bottom of a shallow ocean during the late Cretaceous period. The rock holds the 87 million-year-old signature of a 'resonance transition' in the orbits of Mars and Earth, definitive geologic evidence that the orbits of the planets in our solar system behave differently than prevailing theory, which held that the planets orbit like clockwork in a quasiperiodic manner.
Plumbing a 90 million-year-old layer cake of sedimentary rock in Colorado, a team of scientists from the University of Wisconsin-Madison and Northwestern University has found evidence confirming a critical theory of how the planets in our solar system behave in their orbits around the sun.

The finding, published Feb. 23, 2017 in the journal Nature, is important because it provides the first hard proof for what scientists call the "chaotic solar system," a theory proposed in 1989 to account for small variations in the present conditions of the solar system. The variations, playing out over many millions of years, produce big changes in our planet's climate -- changes that can be reflected in the rocks that record Earth's history.

The discovery promises not only a better understanding of the mechanics of the solar system, but also a more precise measuring stick for geologic time. Moreover, it offers a better understanding of the link between orbital variations and climate change over geologic time scales.

Using evidence from alternating layers of limestone and shale laid down over millions of years in a shallow North American seaway at the time dinosaurs held sway on Earth, the team led by UW-Madison Professor of Geoscience Stephen Meyers and Northwestern University Professor of Earth and Planetary Sciences Brad Sageman discovered the 87 million-year-old signature of a "resonance transition" between Mars and Earth. A resonance transition is the consequence of the "butterfly effect" in chaos theory. It plays on the idea that small changes in the initial conditions of a nonlinear system can have large effects over time.

In the context of the solar system, the phenomenon occurs when two orbiting bodies periodically tug at one another, as occurs when a planet in its track around the sun passes in relative proximity to another planet in its own orbit. These small but regular ticks in a planet's orbit can exert big changes on the location and orientation of a planet on its axis relative to the sun and, accordingly, change the amount of solar radiation a planet receives over a given area. Where and how much solar radiation a planet gets is a key driver of climate.

"The impact of astronomical cycles on climate can be quite large," explains Meyers, noting as an example the pacing of Earth's ice ages, which have been reliably matched to periodic changes in the shape of Earth's orbit, and the tilt of our planet on its axis. "Astronomical theory permits a very detailed evaluation of past climate events that may provide an analog for future climate."

To find the signature of a resonance transition, Meyers, Sageman and UW-Madison graduate student Chao Ma, whose dissertation work this comprises, looked to the geologic record in what is known as the Niobrara Formation in Colorado. The formation was laid down layer by layer over tens of millions of years as sediment was deposited on the bottom of a vast seaway known as the Cretaceous Western Interior Seaway. The shallow ocean stretched from what is now the Arctic Ocean to the Gulf of Mexico, separating the eastern and western portions of North America.

"The Niobrara Formation exhibits pronounced rhythmic rock layering due to changes in the relative abundance of clay and calcium carbonate," notes Meyers, an authority on astrochronology, which utilizes astronomical cycles to measure geologic time. "The source of the clay (laid down as shale) is from weathering of the land surface and the influx of clay to the seaway via rivers. The source of the calcium carbonate (limestone) is the shells of organisms, mostly microscopic, that lived in the water column."

Meyers explains that while the link between climate change and sedimentation can be complex, the basic idea is simple: "Climate change influences the relative delivery of clay versus calcium carbonate, recording the astronomical signal in the process. For example, imagine a very warm and wet climate state that pumps clay into the seaway via rivers, producing a clay-rich rock or shale, alternating with a drier and cooler climate state which pumps less clay into the seaway and produces a calcium carbonate-rich rock or limestone."

The new study was supported by grants from the National Science Foundation. It builds on a meticulous stratigraphic record and important astrochronologic studies of the Niobrara Formation, the latter conducted in the dissertation work of Robert Locklair, a former student of Sageman's at Northwestern.

Dating of the Mars-Earth resonance transition found by Ma, Meyers and Sageman was confirmed by radioisotopic dating, a method for dating the absolute ages of rocks using known rates of radioactive decay of elements in the rocks. In recent years, major advances in the accuracy and precision of radioisotopic dating, devised by UW-Madison geoscience Professor Bradley Singer and others, have been introduced and contribute to the dating of the resonance transition.

The motions of the planets around the sun has been a subject of deep scientific interest since the advent of the heliocentric theory -- the idea that Earth and planets revolve around the sun -- in the 16th century. From the 18th century, the dominant view of the solar system was that the planets orbited the sun like clockwork, having quasiperiodic and highly predictable orbits. In 1988, however, numerical calculations of the outer planets showed Pluto's orbit to be "chaotic" and the idea of a chaotic solar system was proposed in 1989 by astronomer Jacques Laskar, now at the Paris Observatory.

Read more at Science Daily

Diamond’s 2-billion-year growth charts tectonic shift in early Earth’s carbon cycle

Gem quality diamond from Letlhakane, containing multiple orange garnets.
A study of tiny mineral 'inclusions' within diamonds from Botswana has shown that diamond crystals can take billions of years to grow. One diamond was found to contain silicate material that formed 2.3 billion years ago in its interior and a 250 million-year-old garnet crystal towards its outer rim, the largest age range ever detected in a single specimen. Analysis of the inclusions also suggests that the way that carbon is exchanged and deposited between the atmosphere, biosphere, oceans and geosphere may have changed significantly over the past 2.5 billion years.

'Although a jeweller would consider diamonds with lots of inclusions to be flawed, for a geologist these are the most valuable and exciting specimens,' said Prof Gareth Davies, of Vrije Universiteit (VU) Amsterdam, who co-authored the study. 'We can use the inclusions to date different parts of an individual diamond, and that allows us to potentially look at how the processes that formed diamonds may have changed over time and how this may be related to the changing carbon cycle on Earth.'

Sixteen diamonds from two mines in north eastern Botswana were analysed in the study: seven specimens from the Orapa mine and nine from the Letlhakane mine. A team at VU Amsterdam measured the radioisotope, nitrogen and trace element contents of inclusions within the diamonds. Although the mines are located just 40 kilometres apart, the diamonds from the two sources had significant differences in the age range and chemical composition of inclusions.

The Orapa diamonds contained material dating from between around 400 million and more than 1.4 billion years ago. The Letlhakane diamond inclusions ranged from less than 700 million and up to 2-2.5 billion years old. In every case, the team were able to link the age and composition of material in the inclusions to distinct tectonic events occurring locally in the Earth's crust, such as a collision between plates, continental rifting or magmatism. This suggests that diamond formation is triggered by heat fluctuations and magma fluid movement associated with these events.

The Letlhakane diamonds also provided a rare opportunity to look back in time to the early Earth. The oldest inclusions date back to before the Great Oxidation Event (GOE) around 2.3 billion years ago, when oxygen produced by multicellular cyanobacteria started to fill the atmosphere, radically changing the weathering and sediment formation processes and thus altering the chemistry of rocks.

Read more at Science Daily

Ancient humans arrived in South America in multiple waves

Sunrise at Lagoa Santa, Minas Gerais, Brazil.
Analysis of ancient human skulls found in southeastern Brazil are providing new insights into the complex narrative of human migration from our origins in sub-Saharan Africa to the peopling of the Americas tens of thousands of years later.

The many differences in cranial morphology, the study of skull shape, seen in Paleoamerican remains found in the Lagoa Santa region of Brazil suggest a model of human history that included multiple waves of population dispersals from Asia, across the Bering Strait, down the North American coast and into South America.

The findings published Wednesday (Feb. 22, 2017) in the journal Science Advances suggest that Paleoamericans share a last common ancestor with modern native South Americans outside, rather than inside, the Americas and underscore the importance of looking at both genetic and morphological evidence, each revealing different aspects of the human story, to help unravel our species' history.

"When you look at contemporary genomic data, the suggestion, particularly for South America, was for one wave of migration and that indigenous South American people are all descendants of that wave," says Noreen von Cramon-Taubadel, an associate professor of anthropology at the University at Buffalo and the paper's lead author. "But our data is suggesting that there were at least two, if not more, waves of people entering South America."

How people settled the Americas is a debate that has continued for years in the scientific community. It's now clear that the first human entry into the Americas began at least 15,000 years ago and dispersed quickly into South America following a coastal Pacific route.

The conundrum of conflicting data between morphology and genetics is among the issues fueling the debate of how people first entered the New World, but von Cramon-Taubadel's conclusions are similar to previous morphological research while also relying on a pioneering method to reach those conclusions.

"We've adopted and modified the method from ecology, but to my knowledge this method has never been used in an anthropological setting before," she says.

In the past, researchers have looked mainly at the overall similarities between the morphology of prehistoric skeletons from the Americas compared with the morphology of living people. Models of dispersal, each with a different number of waves that attempt to match existing data, have also been used.

But von Cramon-Taubadel's current research with Mark Hubbe, an associate professor in the Department of Anthropology at Ohio State University, and University of Tübingen researcher André Strauss, doesn't make any previous assumptions about dispersals. It looks at an existing population as descendants of many possible branches of a theoretical tree of relatedness and then uses statistics to determine where in the tree their sample best fits.

This method has the advantage of not needing pre-determined models of dispersal but rather considers all possible patterns of relatedness.

All living people, von Cramon-Taubadel explains, have a common ancestor, but not all fossils necessarily contribute to the ancestry of living people. Some populations of modern humans did not survive or made only a marginal contribution to living people. So fossils of these extinct humans provide few clues about the ancestry of living people.

Read more at Science Daily

Feb 23, 2017

How cathedral termites got to Australia to build their 'sky-scrapers'

These are mounds of the cathedral termite Nasutitermes triodiae at Litchfield National Park.
They build among the tallest non-human structures (proportionately speaking) in the world and now it's been discovered the termites that live in Australia's remote Top End originated from overseas -- rafting vast distances and migrating from tree-tops to the ground, as humans later did.

Referred to as "cathedral" termites, the Nasutitermes triodiae build huge mounds up to eight metres high in the Northern Territory, Western Australia and Queensland -- representing some of the tallest non-human animal structures in the world.

DNA sequencing found the forebearers, called nasute termites, colonised Australia three times in the past 20 million years or so and evolved from wood to grass-feeding as they adapted to significant environmental changes, including increasingly arid conditions and the conversion of woodlands to grassland habitats in subtropical savannahs and central Australia.

Now a prominent feature of the arid landscape "Down Under," the mounds house millions of termites; this study is the first comprehensive investigation of the evolution of the nesting and feeding of the extended family of termites, through the Australian refugee descendants.

The findings of the international research are published in the Royal Society journal Biology Letters.

Co-lead author of the paper from the University of Sydney, Associate Professor Nathan Lo, said although much was known about the functions of termite mounds -- which include protection from predators -- little had been known about their evolutionary origins.

"We found that the ancestors of Australia's fortress-building termites were coastal tree-dwellers, which arrived in Australia by rafting long distances over the oceans from either Asia or South America," Associate Professor Lo said.

"Once in Australia, they continued to build their nests in trees, but later descended and began building mounds on the ground instead, paralleling the evolution of the other great architects of the world -- human beings, whose ancestors lived in the tree tops some millions of years ago."

Associate Professor Lo, from the University of Sydney's School of Life and Environmental Sciences, said the mounds are an engineering feat when considered in comparison to the tallest structure on Earth -- Dubai's skyscraper the Burj Khalifas.

"Given that a worker termite stands about 3mm in height, these mounds are in human terms the equivalent of four Burj Khalifas stacked on top of each other," he said.

The paper, "Parallel evolution of mound-building and grass-feeding in Australian nasute termites," said ancestral wood feeders would likely have lost the ability to feed on wood as they transitioned to feeding on litter and grass.

Read more at Science Daily

Trilobite eggs in New York

Pyritized trilobite specimens (Triarthrus eatoni) are from the Ordovician Whetstone Gulf Formation (Lorraine Group), upstate New York (USA).
Despite a plethora of exceptionally preserved trilobites, trilobite reproduction has remained a mystery. No previously described trilobite has had unambiguous eggs or genitalia preserved. This study by Thomas A. Hegna and colleagues reports the first occurrence of in situ preserved trilobite eggs from the Lorraine Group in upstate New York, USA.

Like other exceptionally preserved trilobites from the Lorraine Group, the complete exoskeletons are replaced with pyrite. The eggs are spherical to elliptical in shape and nearly 200 micrometers in size.

The location of the eggs is consistent with where modern female horseshoe crabs release their unfertilized eggs from the ovarian network within their head. Trilobites likely released their eggs and sperm through a genital pore of as-yet-unknown location (but probably near the posterior boundary of the head).

Because pyrite preferentially preserves the external features of fossils, there is probably a bias in the fossil record toward the preservation of arthropods that brood eggs externally. If the reproductive biology of these trilobites is representative of other trilobites, they likely spawned with external fertilization as well, which may be the ancestral mode of reproduction for early arthropods.

From Science Daily

The oldest fossilized giant penguin

The foot bones of the new giant penguin (left), compared to those of an Emperor Penguin, the largest living penguin species (right).
Together with colleagues from New Zealand, Senckenberg scientist Dr. Gerald Mayr described a recently discovered fossil of a giant penguin with a body length of around 150 centimeters. The new find dates back to the Paleocene era and, with an age of approx. 61 million years, counts among the oldest penguin fossils in the world. The bones differ significantly from those of other discoveries of the same age and indicate that the diversity of Paleocene penguins was higher than previously assumed. In their study, published in the Springer scientific journal The Science of Nature, the team of scientists therefore postulates that the evolution of penguins started much earlier than previously thought, probably already during the age of dinosaurs.

The fossil sites along the Waipara River in New Zealand's Canterbury region are well known for their avian fossils, which were embedded in marine sand a mere 4 million years after the dinosaurs became extinct. "Among the finds from these sites, the skeletons of Waimanu, the oldest known penguin to date, are of particular importance," explains Dr. Gerald Mayr of the Senckenberg Research Institute in Frankfurt.

Together with colleagues from the Canterbury Museum in New Zealand, Mayr now described a newly discovered penguin fossil from the famous fossil site. "What sets this fossil apart are the obvious differences compared to the previously known penguin remains from this period of geological history," explains the ornithologist from Frankfurt, and he continues, "The leg bones we examined show that during its lifetime, the newly described penguin was significantly larger than its already described relatives. Moreover, it belongs to a species that is more closely related to penguins from later time periods."

According to the researchers, the newly described penguin lived about 61 million years ago and reached a body length of approx. 150 centimeters -- making it almost as big as Anthropornis nordenskjoeldi, the largest known fossil penguin, which lived in Antarctica around 45 to 33 million years ago, thus being much younger in geological terms. "This shows that penguins reached an enormous size quite early in their evolutionary history, around 60 million years ago," adds Mayr.

In addition, the team of scientists from New Zealand and Germany assumes that the newly discovered penguin species also differed from their more primitive relatives in the genus Waimanu in their mode of locomotion: The large penguins presumably already moved with the upright, waddling gait characteristic for today's penguins.

Read more at Science Daily

Surprising dunes on comet Chury

Left, an image of comet Chury showing outgassing of water vapor, which entrains dust (© ESA/Rosetta/NAVCAM). Right, the neck region, between the comet's two lobes. Various types of relief can be seen, including the dunes, at bottom left (circled in red), in the sandy region.
Surprising images from the Rosetta spacecraft show the presence of dune-like patterns on the surface of comet Chury. Researchers at the Laboratoire de Physique et Mécanique des Milieux Hétérogènes (CNRS/ESPCI Paris/UPMC/Université Paris Diderot) studied the available images and modeled the outgassing of vapor to try to explain the phenomenon. They show that the strong pressure difference between the sunlit side of the comet and that in shadow generates winds able to transport grains and form dunes. Their work is published on 21 February 2017 in the journal PNAS.

The formation of sedimentary dunes requires the presence of grains and of winds that are strong enough to transport them along the ground. However, comets do not have a dense, permanent atmosphere as on Earth. Nonetheless, the OSIRIS camera on board the Rosetta spacecraft showed the presence of dune-like forms approximately ten meters apart on 67P/Churyumov-Gerasimenko. They are found on the lobes of the comet as well as on the neck that connects them. Comparison of two images of the same spot taken 16 months apart provides evidence that the dunes moved and are therefore active.

Faced with this unexpected finding, the researchers show that there is in fact a wind blowing along the comet's surface. It is caused by the pressure difference between the sunlit side, where the surface ice can sublimate due to the energy provided by the sunlight, and the night side. This transient atmosphere is still extremely tenuous, with a maximum pressure at perihelion, when the comet is closest to the Sun, 100,000 times lower than on Earth. However, gravity on the comet is also very weak, and an analysis of the forces exerted on the grains at the comet's surface shows that these thermal winds can transport centimeter-scale grains, whose presence has been confirmed by images of the ground. The conditions required to allow the formation of dunes, namely winds able to transport the grains along the ground, are thus met on Chury's surface.

This work represents a step forward in understanding the various processes at work on cometary surfaces. It also shows that the Rosetta mission still has many surprises and discoveries in store.

From Science Daily

New window into the nanoworld

This is Vedran Jelic, PhD student at the University of Alberta and lead author on a new paper pioneering microscopy at terahertz frequencies.
For the first time ever, scientists have captured images of terahertz electron dynamics of a semiconductor surface on the atomic scale. The successful experiment indicates a bright future for the new and quickly growing sub-field called terahertz scanning tunneling microscopy (THz-STM), pioneered by the University of Alberta in Canada. THz-STM allows researchers to image electron behaviour at extremely fast timescales and explore how that behaviour changes between different atoms.

"We can essentially zoom in to observe very fast processes with atomic precision and over super fast time scales," says Vedran Jelic, PhD student at the University of Alberta and lead author on the new study. "THz-STM provides us with a new window into the nanoworld, allowing us to explore ultrafast processes on the atomic scale. We're talking a picosecond, or a millionth millionth of a second. It's something that's never been done before."

Jelic and his collaborators used their scanning tunneling microscope (STM) to capture images of silicon atoms by raster scanning a very sharp tip across the surface and recording the tip height as it follows the atomic corrugations of the surface. While the original STM can measure and manipulate single atoms -- for which its creators earned a Nobel Prize in 1986 -- it does so using wired electronics and is ultimately limited in speed and thus time resolution.

Modern lasers produce very short light pulses that can measure a whole range of ultra-fast processes, but typically over length scales limited by the wavelength of light at hundreds of nanometers. Much effort has been expended to overcome the challenges of combining ultra-fast lasers with ultra-small microscopy. The University of Alberta scientists addressed these challenges by working in a unique terahertz frequency range of the electromagnetic spectrum that allows wireless implementation. Normally the STM needs an applied voltage in order to operate, but Jelic and his collaborators are able to drive their microscope using pulses of light instead. These pulses occur over really fast timescales, which means the microscope is able to see really fast events.

By incorporating the THz-STM into an ultrahigh vacuum chamber, free from any external contamination or vibration, they are able to accurately position their tip and maintain a perfectly clean surface while imaging ultrafast dynamics of atoms on surfaces. Their next step is to collaborate with fellow material scientists and image a variety of new surfaces on the nanoscale that may one day revolutionize the speed and efficiency of current technology, ranging from solar cells to computer processing.

Read more at Science Daily

Feb 22, 2017

Marine Biodiversity Faces Double-Barreled Blast of Human Trouble

Climate change and industrial-scale fishing should be tackled simultaneously in order to prevent potentially catastrophic ecosystem collapse in the world's most diverse marine environments, according to new research.

Six marine biodiversity hotspots in the Atlantic, Indian and Pacific Oceans are being severely impacted by climate change and overfishing, according to the paper published in Science Advances.

"We have critical areas, where you have a long-term anomaly in the environment and those areas are also of high biodiversity," said André Chiaradia, a penguin biologist and one of the study's co-authors. "In some cases these places have extra pressure from commercial fisheries."

The study is the first to overlap global species distribution in oceans with marine areas most at risk from climate change and aimed to identify areas of marine conservation priority around the globe.

In order to do so, researchers compiled a database of 2,183 marine animals and more than three decades worth of information on sea surface temperatures, ocean currents and marine productivity.

They also evaluated industrial fishing data from the Food and Agriculture Organization from the last 60 years.

The environmental data showed an uneven distribution of changes to the Earth's oceans between 1979 and 2014, with the most striking shifts at the poles and the tropics.

Due to global warming, scientists found significant changes to water temperatures, current circulation and nutrient availability.

As the global average temperature has increased, the majority of extra heat has been absorbed by the oceans, leading to changes in the ocean's density, or stratification, the study said.

Increased stratification prevents water and nutrients mixing, which can hamper primary production that forms the basis of the food chain.

Water from melting ice sheets and glaciers, meanwhile, can influence the behavior of ocean currents, changing the marine ecosystem.

To get an idea about how these environmental changes could impact marine life, the researchers identified six marine biodiversity hotspots, all concentrated in the Southern Hemisphere.

They included the Pacific waters off Peru and the Galápagos Islands, stretches of the Atlantic Ocean around Argentina and Uruguay, the coastline stretching from South Africa to Kenya, the central western Pacific Ocean, the waters around New Zealand and eastern and southern Australia, and marine areas in Oceania and the central Pacific Ocean.

Global distribution of marine biodiversity with colors indicating the number of species — red indicating areas with the highest biodiversity.
When the global hotspots were overlaid with fisheries data "a worrying coincidence" was revealed where the world's richest areas for marine biodiversity were those mostly affected by overfishing and climate change, the study said.

"We knew about the fishery impact and high biodiversity. But guess what? These areas have seen a lot of environmental change as well," Chiaradia said.

Although it is unclear on what scale environmental stressors will impact these hotspots, it is unlikely to be beneficial in most cases, according to the study.

Warming oceans may affect production of nutrients essential for bigger animals, while changes to ocean currents could affect food availability.

Combined with the impacts of overfishing, which the authors said had decimated about 70 percent of world fish stocks since World War II, biodiversity hotspots will be put under even greater pressure in the future.

"Accordingly, climate and fishing impacts should not be treated in isolation from each other when it comes to conservation of marine biodiversity," the authors argue.

Read more at Discovery News

Stem Cell Therapy Could Reverse Hearing Loss

Humans have about 15,000 inner ear-hair cells, each one picking up sound vibrations, converting them to electric signals and sending them to the brain for processing.

Over time, loud noise, medications and old age combine to kill these cells — and their microscopic hairs called stereocilia — which leads to hearing loss. Unlike other animals, however, humans and mammals can't regrow them. But a group of scientists based in Boston say they've figured out a way to switch on the body's cellular factories and possibly reverse hearing loss.

"The biology is there, we just need to awaken it," said Jeffrey Karp, associate professor at Brigham and Women's Hospital, Harvard Medical School and an author on the new study appearing Tuesday in the journal Cell Reports. "For some reason there are brakes that we need to release for a short period of time to allow new hair cells to be produced."

Karp and colleagues were able to regrow the hair cells by activating a stem cell in the cochlea called Lgr5 with a small molecule drug treatment. A similar stem cell is found in the human intestine and allows the body to regrow the exterior lining of the organ every five days.

The team also obtained a human cochlea from a patient who suffered from cancer and were able to regrow hair cells with their drug treatment.

"We don't want to provide false hope, but we are highly encouraged by this work. And our ability to produce bona fide functional hair cells is very compelling," Karp said.

The next step is taking the experimental data and starting a human clinical trial. Karp and Robert Langer of MIT are co-founders in a small startup firm, Frequency Therapeutics, that's working toward a phase I trial in the next 18 months, according to Karp.

A possible drug treatment for hearing loss could help the 360 million people worldwide who suffer from the condition.

"Their proposal is very novel and essentially by activating these supporting cells, a natural process will take over and a certain percentage would become hair cells capable of playing a role in the encoding of sound," said Nicolas Reed, an instructor in otolaryngology at the Johns Hopkins School of Medicine. "I don't see any obvious negative indications right now."

Read more at Discovery News

The Andromeda Galaxy Could Be Buzzing With Dark Matter

There's something peculiar going on in the core of Andromeda, the Milky Way galaxy's nearby cousin.

Using NASA's Fermi Gamma Ray Observatory, astronomers have been able to detect a powerful source of gamma-ray radiation emanating from Andromeda and it could be the fingerprint of one of the biggest mysteries hanging over modern cosmology.

The gamma-ray emissions could be generated by the annihilation of dark matter particles and a similar signal has been detected coming from our own galaxy.

Dark matter constitutes nearly 85 percent of all mass in the universe (and normal matter — all visible stuff — therefore accounts for only 15 percent of all matter), but because it doesn't interact with the electromagnetic force, i.e. light, we cannot directly "see" it. We can, however, indirectly detect it by observing its gravitational effects on normal matter on galactic and cosmological scales.

The only problem is that we don't know what "it" is. But this new Fermi observation may bring us one step closer.

Astrophysicists know that galaxies emit gamma-rays, but to have such a powerful gamma-ray signal coming from the center of Andromeda means something strange is going on.

"We expect dark matter to accumulate in the innermost regions of the Milky Way and other galaxies, which is why finding such a compact signal is very exciting," said astrophysicist Pierrick Martin, of the National Center for Scientific Research and the Research Institute in Astrophysics and Planetology in Toulouse, France.

It is thought that when dark matter particles, such as hypothesized weakly-interacting massive particles (or WIMPS), collide, they annihilate, releasing a sudden burst in energy. This energy is in the form of gamma-rays, so where Fermi sees an intense gamma-ray emitting region, it could indicate the location of a dense cloud of dark matter.

There could be another explanation, however. The researchers point out that a dense accumulation of pulsars could also generate an intense gamma-ray signal, but Andromeda is 2.5 million light-years away, so there's no way to resolve individual pulsar sources of gamma-rays.

But as we know the Milky Way also generates gamma-ray radiation in its core, the researchers hope to compare the signal from Andromeda and the Milky Way to hopefully reveal if the signal is being caused by pulsars (that we can resolve in our own galaxy) or, more excitingly, dark matter particles annihilating in the cores of both galaxies.

Read more at Discovery News

A Nearby Star Has 7 Earth-Sized Planets — and 3 Could Be Habitable

A little star located a neighborly 40 light-years away has at least seven planets in its clutches, all about the size of Earth.

Three of the seven planets orbit in the star's so-called "habitable zone," where temperatures are suitable for water, if any exists, to pool on their surfaces.

"They could have some liquid water and maybe life," said lead researcher Michael Gillon, with the University of Liege in Belgium.

The discovery, reported Wednesday in the journal Nature, puts the planets orbiting the star TRAPPIST-1 at the top of astronomers' list of places to look for life beyond the solar system.

"I think that we've made a crucial step towards finding if there is life out there. I don't think that before we had the right planets to discover… if there was [life]. Here, if life managed to thrive and releases gases similar to that that we have on Earth, then we will know," said University of Cambridge astronomer Amaury Triaud.

Scanning the planets for methane, water, ozone and other chemicals tied to life will take another generation of telescopes, including the James Webb Space Telescope, which is scheduled to launch next year.

Scientists reported last year that TRAPPIST-1 had three planets in orbit. Follow-up studies with ground telescopes and NASA's infrared Spitzer space telescope revealed at least four more sister words, all orbiting closer to their parent star than Mercury orbits the sun.

"It would be really fun if there were more," Triaud wrote in an email to Seeker.

In a related essay in Nature, astronomer Ignas Snellen, with Leiden Observatory in The Netherlands, noted that even if the TRAPPIST-1 planets are lifeless now, they have lots of time for it to evolve.

"In a few billion years, when the Sun has run out of fuel and the solar system has ceased to exist, TRAPPIST-1 will still be only an infant star. It burns hydrogen so slowly that it will live for another 10 trillion years more than 700 times longer than the Universe has existed so far, which is arguably enough time for life to evolve," Snellen wrote.

Read more at Discovery News

Feb 21, 2017

Face of Man Brutally Murdered 1,400 Years Ago Reconstructed

This is the face of a handsome man who was "brutally killed" 1,400 years ago, according to researchers at the University of Dundee, Scotland.

The remains were discovered in the Scottish Highlands, in a recess of a cave on the coast of the Black Isle peninsula.

Archaeologists and volunteers were digging at the site to determine when the cave might have been occupied. They were astonished to find a well-preserved skeleton in a cross-legged position, with large stones holding down his legs and arms.

Forensic investigation not only revealed the features of the young man, but also reconstructed the gruesome details of his violent death.

The man suffered at least five blows which caused fractures to his head and face, breaking his teeth and jaw. In the strike intended to end his life, a weapon was driven through the skull from one side and out the other.

Radiocarbon dating of a bone sample indicates the young man died sometime between 430 and 630 A.D., commonly referred to as the Pictish period in Scotland. In fact, hearths and extensive iron-working debris in the cave revealed the site had been used for iron-smithing during that period.

The cave where the skeleton was found and the facial reconstruction.
The Picts were a mysterious people who lived in eastern and northern Scotland during the Late Iron Age and Early Medieval periods. They left no written record of their history. All that is known about them comes from images they carved on stones and from Roman and Scottish writers who came later.

According to these records, the Picts frightened their enemies and fought off Rome's invading legions by decorating their bodies with tattoos and woad — a blue plant dye. The practice was depicted in Mel Gibson's 1995 film "Braveheart."

Not much is known about the skeleton.

"As you can see from the facial reconstruction, he was a striking young man," professor Dame Sue Black, director at the Center for Anatomy and Human Identification, University of Dundee, said.

Black and her team first scanned the skull with a 3D laser scanner and reconstructed it in the computer. Then they added tissue depth pegs and the anatomical muscular structure.

"Artificial skin was then overlaid in the computer and then the resulting surface textured," Black told Seeker.

The skeleton was found in an unusual cross-legged position, with large stones holding down his legs and arms.
By analyzing the skull, Black and colleagues were able to detail the various stages that led the Pict man to his brutal end.

"The first impact was by a circular cross-section implement that broke his teeth on the right side," Black said.

The blow was followed by another one in which the same weapon, used like a fighting stick, broke the jaw on the left. The third blow caused a fracture to the back of the head. The man likely fell from the blow to his jaw onto a hard object, perhaps stone.

"The fourth impact was intended to end his life as probably the same weapon was driven through his skull from one side and out the other as he lay on the ground," Black explained.

The fifth injury is believed to have come from a larger weapon, since "a hole, larger than that caused by the previous weapon, was made in the top of the skull," the researchers said.

Black explained to Seeker that the man was likely unconscious during the fatal fourth trauma, which went through his temporal regions.

"I suspect that he was largely rendered unconscious from his second trauma which was the blow to his jaw. That would have knocked him down and he then hit his head," Back said.

Death came quickly for the unlucky man.

"From first impact to unconsciousness, it could have been just a very few seconds," Black said.

Why the man was killed remains a mystery.

Read more at Discovery News

DNA Reveals an Early American Dynasty Centered on Women

When U.S. Army Lt. James H. Simpson and his guide Carravahal first entered Chaco Canyon, New Mexico, during an 1849 military expedition, they were so awed by the remains of one enormous structure that they named it Pueblo Bonito, meaning "Beautiful Town." Subsequent excavations revealed around 650 rooms within Pueblo Bonito, including burials packed with thousands of pieces of jewelry.

New DNA analysis of human remains within the burials reveals a prehistoric matrilineal dynasty, where lineage, birthright and social status were traced through the mother's ancestry rather than the father's, as is common in patriarchal societies. Researchers believe the elite women-centered dynasty lasted for 330 years, from 800 to 1130 A.D.

The findings, published in the journal Nature Communications, represent the first time that DNA and archaeological analysis have documented hereditary relationships among individuals within an elite lineage in the absence of a written record. While some early Native Americans like the Mayans developed writing systems, others such as the Chacoan society at Pueblo Bonito did not.

"Historians have long debated how Chaco was organized politically," lead author Douglas Kennett, head of the Pennsylvania State University Department of Anthropology, told Seeker. "One theory is that the society was egalitarian (where all people are viewed as equals). On the other end of the spectrum, some have theorized that it was a strong state level (class structured) society. Our research suggests that it was a complex prehistoric society with at least some hierarchical element."

Selection of turquoise and shell artifacts found in Room 33 of Pueblo Bonito (Chaco Canyon, New Mexico).
The burial crypt within Pueblo Bonito housed incredible treasures. These included close to 20,000 pieces of turquoise and thousands of shell beads and pendants that were all originally part of necklaces, anklets and bracelets. Wooden ceremonial staffs, ceramic bowls and pitchers, multiple musical instrument flutes and other objects were also found at the site.

Adjacent rooms contained still more riches, such as wooden carvings, jewelry and ceramics. Perhaps most surprising was evidence — including copious mounds of guano — for multiple scarlet macaws that once lived in the structure at the time of the dynasty.

"Since these birds are not native to the area, the scarlet macaws must have been brought in from tropical locations in Mexico," Kennett said. "The birds have the ability to talk. Consider that this time period was long before the invention of televisions and other forms of entertainment, so having an entire room full of exotic colorful talking birds must have been pretty spectacular."

Pueblo Bonito as photographed from the northern rim of Chaco Canyon, New Mexico.
The Chacoans, one of North America's earliest structured societies, lived in massive, multi-storied buildings known as great houses. No large trees are known to have existed in the immediate area, so it is thought that large logs were brought in to build the houses, which also include stone masonry. Pueblo Bonito is the largest of the great houses, and has been a focus of research over the decades.

For the latest study, Kennett and his team collected DNA samples from nine of the individuals who were buried inside the Pueblo Bonito crypt, known as "Room 33." The genetic analysis found that all of the individuals had identical mitochondrial genomes. Since mitochondrial DNA is inherited solely from one's mother, all of the individuals belonged to the same maternal lineage. The individuals buried at Pueblo Bonito include both men and women, who were interred sequentially over the 330-year period.

While the dynasty's burial was full of riches, the remains of other people in the region outside of Pueblo Bonito were more humble. Kennett said, "Some of these other remains were even found in trash middens."

Robert Drennan of the University of Pittsburgh's Center for Comparative Archaeology told Seeker that the new research "provides a highly visible reminder of a burial that is vitally important evidence of social inequality."

Pottery and wooden flute found in Room 33 of Pueblo Bonito (Chaco Canyon, New Mexico).
The evidence supports that among the haves and have-nots at Chaco Canyon around 1,200 years ago, men and women fell into both groups.

"Women living at Pueblo Bonito likely had power and a great deal of influence on what was happening in society," Kennett said.

Women among the elites might even have had better status, in terms of political standing, than most women around the world do now.

"In the societies in which most of the world's people live today, the important roles in political leadership and its transmission from one leader to the next are occupied overwhelmingly by men," Drennan explained. "Anthropologists, who study the full array of human societies that have existed in the present and the past, know that this is not somehow the 'natural' or necessary state of affairs."

"In many instances, such roles are played extensively or predominantly by women," he said. "Examples of matrilineal systems among native North Americans include the Hopi, the Iroquois, and the Lenape. The evidence presented by Kennett and his colleagues of the importance of matrilineages in ancient Chaco society adds to this list of societies in which women and their roles are especially important and respected."

There is a difference between a matriline and a matriarchy, though. It is possible for a society to have a female line of inheritance of title and property, but still be a population that is controlled primarily by men. The Jewish culture, for example, has matrilineal descent, but mostly male leaders.

Within Pueblo Bonito, "The two very high status crypt burials were males," Stephen Lekson, curator of archaeology and a professor of anthropology at the University of Colorado Museum of Natural History, told Seeker. "The argument (posed in the paper) is for matrilineal descent, not necessarily matriarchal governance."

The two males were isolated from the other remains and surrounded by turquoise and finery. One of the men died in his 40s after a lethal blow to the head.

"We are not sure what led to the blow," Kennett said. "It is possible that he was killed in battle. Although this was not known to be a particularly violent interval, there is other evidence in the surrounding area for conflict, such as arrow wound injuries."

Read more at Discovery News

This Ancient Sea Monster Was a Spineless Beast

The Tully monster, a bizarre beast that plied the seas 307 million years ago, has long mystified scientists. Its features, including eyes like a hammerhead's and a pincer-like mouth, look like they belong on Dr. Seuss creatures, and have made it difficult for scientists to classify it. But last year, two different scientific groups did just that, independently announcing that the ancient animal was likely a marine vertebrate.

However, those two groups got it wrong, according to a new paper published online Monday (Feb. 20) in the journal Paleontology.

Rather, the Tully monster (Tullimonstrum gregarium) was likely an invertebrate — a spineless beast, researchers said in the new study.

"This animal doesn't fit easy classification because it's so weird," study lead researcher Lauren Sallan, an assistant professor in the Department of Earth and Environmental Science at the University of Pennsylvania, said in a statement. "It has these eyes that are on stalks, and it has this pincer at the end of a long proboscis, and there's even disagreement about which way is up. But the last thing that the Tully monster could be is a fish."

The sea monster has mystified scientists for nearly 60 years. Amateur fossil collector Francis Tully discovered the first specimen in Illinois in 1958, and scientists have found thousands more since then. The species attracted so much public interest that it became the state fossil of Illinois, and murals of the creature still decorate the sides of U-Haul trucks.

However, no one could clearly define the monster: Some called it a worm; others classified it as a shell-less snail. And there was even a push to call it an arthropod, a group that includes lobsters, spiders and insects, Sallan said.

In the first study of the creature, published in March 2016 in the journal Nature, researchers looked at more than 1,200 Tully monster fossils. They reported seeing a light band going down the creature's midline. This band was likely a notochord, a type of primitive backbone, they said. Moreover, the fossils had remains of internal organs, such as gill sacs, that were characteristic of vertebrates, and teeth that looked like those of a lamprey, a jawless fish, they said.

However, these descriptions are off base, Sallan and her colleagues said. The faint circles that are interpreted as gill slits sit on septa (thin walls or cavities) rather than gill tissues or pouches, suggesting that they weren't involved in breathing, Sallan and her colleagues wrote in the study. In addition, "a dark circle under the 'gills' was interpreted as the liver, despite the liver's universal placement in vertebrates' posterior to [behind] the pharynx," the researchers wrote in the study.

"In the marine rocks, you just see soft tissues; you don't see much internal structure preserved," Sallan said.

In the other study, published in April 2016 in the journal Nature, scientists used a scanning electron microscope to show that the monster's eyes held melanosomes — structures that produce and store melanin. These complex tissues indicated that the creature was likely a vertebrate, the researchers of that study said.

But animals that aren't vertebrates, including arthropods and cephalopods, such as the octopus, also have complex eyes, Sallan and her colleagues noted.

"Eyes have evolved dozens of times," Sallan said. "It's not too much of a leap to imagine Tully monsters could have evolved an eye that resembled a vertebrate eye."

The new analysis showed that the creature had a cup eye — in essence, a simple structure that doesn't have a lens, she said. "So the problem is, if it does have cup eyes, then it can't be a vertebrate, because all vertebrates either have more complex eyes than that or they secondarily lost them," Sallan said. "But lots of other things have cup eyes, like primitive chordates, mollusks and certain types of worms."

Of the more than 1,200 Tully monster specimens analyzed, none appeared to have structures seen in aquatic vertebrates, notably otic capsules — structures in the ear that help animals with balance — and a lateral line, which is a sensory structure that helps fish orient their bodies, according to the researchers of the new study.

"You would expect at least a handful of the specimens to have preserved these structures," Sallan said.
"Not only does this creature have things that should not be preserved in vertebrates; it doesn't have things that absolutely should be preserved."

Other scientists who have studied the monster said they are glad that the new study is drawing attention from the scientific world back to Tully.

"It is important to remember that this is how science works," said James Lamsdell, an assistant professor of paleobiology at West Virginia University, who also co-authored the March 2016 study calling the Tully monster a vertebrate. "It is natural for new ideas, based off new information, to be questioned by the scientific community. This back-and-forth drives research, and further studies will continue to test the position of the Tully monster among the vertebrates."

However, the authors of the new study "do not present any new information, nor do they restudy the specimens," Lamsdell told Live Science in an email. "As such, no convincing alternatives are presented for where this strange animal fits on the tree of life."

Read more at Discovery News

60K-Year-Old Microbes Have Been Found in a Mexican Mine

NASA scientists have discovered living microorganisms trapped inside crystals for as long as 60,000 years in a mine in Mexico.

These strange ancient microbes have apparently evolved so they can survive on a diet of sulfite, manganese and copper oxide, said Penelope Boston of NASA's Astrobiology Institute in a presentation over the weekend at a conference of the American Association for the Advancement of Science.

"This has profound effects on how we try to understand the evolutionary history of microbial life on this planet," she said.

They were discovered in the Naica mine, a working lead, zinc and silver mine in the northern Mexican state of Chihuahua. The mine is famous for its huge crystals, some as long as 50 feet (15 meters).

The discovery has not yet been published in a peer-reviewed scientific journal, but it has led Boston to believe that living organisms may also have survived in the extreme environments of other planets and moons in our solar system.

She said about 100 different kinds of microorganisms — most of them bacteria — have been found locked in Naica crystals for periods ranging from 10,000 to 60,000 years. Ninety percent of them have never been observed before now, she said.

The discovery of these ultra-hardy microorganisms has been a windfall for researchers but also a source of concern for astrobiologists thinking about bringing back samples collected on space missions in the solar system.

The extreme conditions under which these microbes have survived raises the possibility that dangerous extraterrestrial organisms could accidentally hitch a ride to Earth on a returning spaceship.

Astrobiologists also worry about the risk that Earth organisms could contaminate other planets in the course of missions to places like Mars, which has already been visited by several US robots.

NASA sterilizes its spacecraft and equipment before launching them into space. But there is always a risk that ultra-resistant microorganisms will survive.

"How do we ensure that life-detection missions are going to detect true Mars life or life from icy worlds rather than our life?" asked Boston.

The concerns are not new. During the Apollo missions of the 1960s and '70s, astronauts returning from the moon were quarantined.

Read more at Discovery News

Feb 20, 2017

These Cutting-Edge Solar Panels Roll Up Like Wrapping Paper

This solar panel certainly doesn't look like one at all. Instead of the classic rigid panel, the flexible solar material created by Albuquerque-based mPower Technology Inc. seems like a cross between metallic wrapping paper and one of those reflective sun shades for car windshields.

The clever mesh design means this solar panel is lightweight, foldable and highly efficient. Microsystems-enabled photovoltaics technology has actually been in development for several years, but it took a big step forward recently, when mPower Technology signed a licensing agreement with Sandia National Laboratories.

Called Dragon SCALES, mPower Technology's product is actually covered in miniature solar cells known as "solar glitter." The SCALES part stands for semi-conductor active layer embedded solar, FastCo.Exist reported. If one cell stops working or becomes shaded, the rest of the cells continue working.

"The key limitation to silicon is that if you bend and flex it, it will crack and shatter," mPower Technology's founder and CEO Murat Okandan said in a press statement. "Our technology makes it virtually unbreakable while keeping all the benefits of high efficiency, high reliability silicon PV."

Okandan envisions the company's tough and bendy solar panels going into satellites and drones as well as biomedical devices and consumer products. Imagine unfurling sheets on rooftops to install photovoltaics in record time or stuffing a roll in your backpack. Hey, is that a yoga mat? Nope, it's my portable solar.

I really thought that with all the technological advancements happening in the last decade-plus, we'd be able to buy rolls of photovoltaics at the hardware store by now. Blending flexibility with efficiency has been an enormous challenge, though. Okandan and his team had to get the microdesign and microfabrication techniques just right.

Prior to starting mPower Technology in 2015, Okandan worked on microsystems-enabled photovoltaics for Sandia as an employee. He launched the company through Sandia's Entrepreneurial Separation to Transfer Technology program, which supports spinoffs.

The new license between mPower Technology and Sandia is expected to help speed up the commercialization of solar glitter. I'm eager to see how it goes, not least because we could use more glitter in general.

From Discovery News

Elephant Numbers in 'Sanctuary' Collapse by 80 Percent Due to Poaching

The forest elephant population within a supposed "sanctuary" in Central Africa declined by more than 80 percent over a decade's time due to poaching, new research finds.

The loss, representing about 25,000 elephant deaths, highlights how sanctuaries — while necessary to separate defined wilderness regions from more populated areas — can also increase threats to certain animals, since their populations then become so concentrated in particular areas.

In this case, documented in the journal Current Biology, the killings occurred at Gabon's Minkébé National Park, one of Central Africa's largest and most important preserves.

"Across Central Africa, forest elephant populations are being more and more restricted to protected areas, and so these will be the areas targeted by poachers," lead author John Poulson told Seeker.

Poulson, an assistant professor of tropical ecology at Duke University's Nicholas School of the Environment, and his colleagues had to overcome challenges in attempting to estimate numbers of the forest elephants in the park. He explained that most other elephants live in savanna regions, where aerial surveys can be used to accurately count elephants.

In forests, however, researchers must depend upon field teams walking over long distances to count elephant dung piles. Densities of poop piles are then converted to densities of elephants, with great care needed to factor in weather effects, such as the fact that greater rainfall can lead to faster decay of the elephant waste.

Using this method, the scientists determined that the population of forest elephants in the central and northern parts of the park between 2004 and 2014 was basically erased. Losses also occurred over the same period in the southern part of the park, but were not as substantial.

A lone forest elephant in Gabon's Minkébé National Park.
Numerous eyewitness accounts and the still-flourishing ivory trade offer evidence that poachers killed the forest elephants. Poulson said that Cameroon's national road, which runs very close to the central and northern parts of the park, makes it fairly easy for Cameroonese poachers to access the park and transport their illegal haul back to their nation's largest city, Douala, which is a major hub of the international ivory trade.

Largely because of reports of poaching in Minkébé National Park, the Gabon government raised the status of forest elephants to "fully protected" in 2011, Pouson said. That same year, the federal authorities doubled the budget of the country's Parks Agency, growing its protection staff by 300 people.

They also created the National Park Police, posting 100 military personnel permanently in Minkébé to shore up protection of the park and to attempt to quell the extermination of elephants. In 2012, Gabon became the first Central African country to burn its entire ivory stock.

Poulson said, "While these efforts are admirable and necessary, by themselves they didn't stop poaching in the area, as evidenced by continued poaching of elephants in recent years."

Guards are posted along the Cameroon-Gabon border and other important entry points, but Poulson said, "The problem is that the area is very large, and poachers will always find a way to slip through if the stakes are high enough."

Poachers obviously have not forgotten the elephants and their ivory, but Poulson and others use the word "forgotten" to describe forest elephants due to both the ongoing threats to the pachyderm's populations and the elephant's status within the conservation community. It is estimated that 100,000 forest elephants live in Gabon now.

Poulson primarily believes forest elephants are forgotten "because of the failure of the international community to recognize the forest elephant as a distinct species. Currently, IUCN (International Union for Conservation of Nature) and CITES (Convention on the International Trade in Endangered Species) only recognize the African elephant, which includes the forest and savanna subspecies, and which is listed as 'vulnerable.'"

The argument for recognizing forest elephants as a distinct species lies in the fact that the genetic differences separating these elephants from African savanna elephants is comparable in magnitude to the differences between modern Asian elephants and the extinct mammoths.

Young forest elephant in Gabon.
Forest elephants do not become pregnant for the first time until they are 23 years of age, and they produce only one calf every five to six years. Savanna elephants, on the other hand, begin breeding at around 12 years of age and typically produce young at three to four year intervals. Forest elephants also tend to be much smaller, in terms of both stature and weight, than savanna elephants.

Politics could help to explain why forest elephants are "forgotten" and have not been recognized as a unique species.

"There is concern that two different species have not been recognized because that would reduce the estimated population of savanna elephants, and trade of its ivory would no longer be permitted," Poulson said. "This could result in 3 southern African nationals pulling out of CITES because they want to sell their ivory stocks."

Read more at Discovery News

Bee decline threatens US crop production

A new study of wild bees identifies 139 counties in key agricultural regions of California, the Pacific Northwest, the Midwest, west Texas and the Mississippi River valley that face a worrisome mismatch between falling wild bee supply and rising crop pollination demand.
The first-ever study to map U.S. wild bees suggests they are disappearing in the country's most important farmlands -- from California's Central Valley to the Midwest's corn belt and the Mississippi River valley.

If wild bee declines continue, it could hurt U.S. crop production and farmers' costs, said Taylor Ricketts, a conservation ecologist at the University of Vermont, at the American Association for the Advancement of Science (AAAS) annual meeting panel, Plan Bee: Pollinators, Food Production and U.S. Policy on Feb. 19.

"This study provides the first national picture of wild bees and their impacts on pollination," said Ricketts, Director of UVM's Gund Institute for Ecological Economics, noting that each year $3 billion of the U.S. economy depends on pollination from native pollinators like wild bees.

At AAAS, Ricketts briefed scholars, policy makers, and journalists on how the national bee map, first published in the Proceedings of the National Academy of Sciences in late 2015, can help to protect wild bees and pinpoint habitat restoration efforts.

At the event, Ricketts also introduced a new mobile app that he is co-developing to help farmers upgrade their farms to better support wild bees.

"Wild bees are a precious natural resource we should celebrate and protect," said Ricketts, Gund Professor in UVM's Rubenstein School of Environment and Natural Resources. "If managed with care, they can help us continue to produce billions of dollars in agricultural income and a wonderful diversity of nutritious food."


The map identifies 139 counties in key agricultural regions of California, the Pacific Northwest, the upper Midwest and Great Plains, west Texas, and Mississippi River valley, which appear to have most worrisome mismatch between falling wild bee supply and rising crop pollination demand.

These counties tend to be places that grow specialty crops -- like almonds, blueberries and apples -- that are highly dependent on pollinators. Or they are counties that grow less dependent crops -- like soybeans, canola and cotton -- in very large quantities.

Of particular concern, some crops most dependent on pollinators -- including pumpkins, watermelons, pears, peaches, plums, apples and blueberries -- appeared to have the strongest pollination mismatch, growing in areas with dropping wild bee supply and increasing in pollination demand.

Globally, more than two-thirds of the most important crops either benefit from or require pollinators, including coffee, cacao, and many fruits and vegetables.

Pesticides, climate change and diseases threaten wild bees -- but their decline may be caused by the conversion of bee habitat into cropland, the study suggests. In 11 key states where the map shows bees in decline, the amount of land tilled to grow corn spiked by 200 percent in five years -- replacing grasslands and pastures that once supported bee populations.


Over the last decade, honeybee keepers facing colony losses have struggled with rising demand for commercial pollination services, pushing up the cost of managed pollinators -- and the importance of wild bees.

"Most people can think of one or two types of bee, but there are 4,000 species in the U.S. alone," said Insu Koh, a UVM postdoctoral researcher who co-hosted the AAAS panel and led the study.

"When sufficient habitat exists, wild bees are already contributing the majority of pollination for some crops," Koh adds. "And even around managed pollinators, wild bees complement pollination in ways that can increase crop yields."

Read more at Science Daily

'Alternative Facts' Have Plagued Science for Decades

Kellyanne Conway, counselor to President Donald Trump, used the phrase "alternative facts" earlier this year during a "Meet the Press" interview, in which she defended White House Press Secretary Sean Spicer's false statement about the size of the crowd at Trump's inauguration. While the phrase is newly infamous as a result, the phenomenon that it describes has a long history in both politics and science, according to an analysis presented today at the annual meeting of the American Association for the Advancement of Science in Boston.

Public radar tends to be up for demonstrably false or implausible claims made by politicians and their spokespeople, but researchers say many people were duped in the past by alternative scientific "facts," and that the problem persists today.

"My main message is that, just as we need to be on the lookout for false or misleading information about politics and pop culture, we also need to be on the lookout for false or misleading information about science," Kevin Elliott, who conducted the analysis, told Seeker.

"Living an hour away from Flint, Mich., I'm especially cognizant of the ways that the lead industry tried to downplay the hazards of lead almost a hundred years ago in order to promote the use of lead in drinking water pipes and in gasoline," said Elliott, an associate professor at Michigan State University and the author of the book "A Tapestry of Values: An Introduction to Values in Science."

He and others contacted by Seeker focused on four general areas where alternative facts concerning scientific matters have been especially prevalent and damaging: the tobacco industry, the drug industry, the manufacturing industry and climate change.


In the 1950s American tobacco producers created the Tobacco Industry Research Committee, whose purpose was to cast doubt on independent scientific research that was increasingly showing the harms of cigarette smoking, said Erik Conway, a historian at NASA's Jet Propulsion Laboratory who co-authored, with Harvard's Naomi Oreskes, the book "Merchants of Doubt."

"They did this by funding critiques of academic or government science," Conway said, "by funding research programs designed to blame other activities for smoking's health effects, and even by publishing their own 'scientific' journal to have an apparently independent venue to publish their misleading studies in."

"They were successful in fending off tobacco regulation this way for nearly 70 years."

The effort led to what was later called "The Tobacco Strategy" by Oreskes and Conway. The strategy, she explained, involved creating uncertainty about the science behind smoking and health, stating that health claims were exaggerated, arguing that medical innovations and technology could solve any related problems, and emphasizing that there was no need for government interference.

Conway said that the tobacco industry even created "Bad Science: a Resource Book," to help other industries understand "how to play the game."


Sergio Sismondo, a professor at Queen's University who has long studied the drug industry, told Seeker that certain players within the pharmaceutical industry "have supported and promoted alternative facts to cloud issues about how effective and safe certain products are, and about the structure of the drug industry as a whole."

As examples, he mentioned a diabetes drug that was introduced in 1999, even though "internal documents already showed that the drug carried heart risks." Sismondo said that several years later, in 2007, the company making the drug "engaged in a quick campaign to cloud the issue."

More generally, he shared that every decade or so, a university's drug development center publishes a figure for the cost of developing a prescription drug. The most recent from 2014, he said, was $2.6 billion.

"The research is supported and then promoted by the drug industry, which uses figures like that to justify high prices, long patents and more, but the figure is grossly misleading, because it rolls in various costs that could be seen as marketing and other business costs," Sismondo said. He added that the figure also focuses on new molecules at the center of research efforts, when actually many companies incur "much lower costs when they repurpose molecules."


Problems related to the promotion of misleading or false claims extend to some manufacturers of other products too, Elliott said. For example, he said the known health hazards related to asbestos and vinyl chloride, in addition to lead, were withheld from the public so that the manufacturers "could promote false information about the safety of their products."

Like the tobacco industry, these companies became experts about "manufacturing doubt" over scientific evidence challenging the safety and health risks associated with their products. David Michaels, former head of the Occupational Safety and Health Administration, addressed the subject in detail in his book "Doubt Is Their Product."

A recent instance involved German automaker Volkswagen, which Elliott said cheated on emissions tests by installing a device in diesel engines that could detect when a test was being administered, and could change the way the vehicle performed to improve results. The device, he explained, allowed the company to sell its cars in the U.S. while its engines emitted pollutants up to 40 times above what's accepted by the Environmental Protection Agency. The automaker last month admitted guilt and agreed to pay $4.3 billion in criminal and civil penalties, reported CBS News.

Climate Change

Elliott, Oreskes, Conway and many others believe that "The Tobacco Strategy" continues to be followed by big oil companies in response to science concerning climate change. Heather Douglas of the University of Waterloo prefers the expletive "bullshit" instead of "alternative facts," since the phrase popularized by Kellyanne Conway "suggests a possible equivalency between one set of facts and another, and this is just not the case," she told Seeker. "Fact-checking by the media and tracking down sources readily reveals what is reliable and what is not, and the suggested equivalence is illusory.

"There are lots of things to disagree about in the realm of climate change — what are the regional climate projections, what energy policies should we adopt to mitigate the problem, etc. — but whether humans are a substantial cause is no longer one of them."

Polls and regulation concerning smoking of tobacco products indicate that most people now believe smoking cigarettes poses health risks. A Pew poll last year, however, found that nearly three-quarters of American polled do not trust that there is a large "scientific consensus" among climate scientists on human activities being the cause of client change. In response, Erik Conway said, "No one wants to believe that he or she, personally, is helping to destroy the world's ecosystems, and unlike smoking — a personal choice that can be reversed — no one in the industrialized world can stop emitting, because we're trapped in an infrastructure that leaves us no choice."

"So we live in denial instead," he said. "That's one reason the denialist message resonates so powerfully."

The Problem May Be Getting Worse

Although problems associated with misleading or false science are nothing new, several factors appear to be drive the current use of "alternative facts." One is the political climate, particularly in the U.S., Elliott said. "It's possible that our hyper-partisan political climate and our polarized use of social media has made us all more susceptible to accepting questionable scientific claims when they appeal to our political preferences."

Douglas agrees. She said that "the echo-chambers of social media exacerbate the problem of bullshit."

Genuine disagreement among scientists is an important, inherent part of the discipline, and is critical to the evolution of scientific knowledge. It can therefore be challenging to distinguish legitimate scientific debate from statements made by those who continue to follow "The Tobacco Strategy" or similar deceptive tactics.

"We need to look at who supports different facts," Sismondo said. "When one side of a disagreement is supported primarily by (self)-interested parties, whether directly or indirectly, that should lead us to discount that side. We can never completely discount challenges to accepted facts, but we should also recognize that sometimes the challenges are motivated by greed. These challenges can nitpick away at accepted knowledge, but often this nitpicking is scientifically frivolous."

Read more at Discovery News