Hubble finds spiraling stars, providing window into early universe

Stars are the machines that sculpt the universe, yet scientists don't fully know how they form. To understand the frenzied 'baby boom' of star birth that occurred early in the universe's history, researchers turned to the Small Magellanic Cloud, a satellite galaxy of the Milky Way. This nearby galaxy has a simpler chemical composition than the Milky Way, making it similar to the galaxies found in the younger universe, when heavier elements were more scarce. This allows it to serve as a proxy for the early universe.

Two separate studies -- the first with the Hubble Space Telescope, and the second with the European Southern Observatory's Very Large Telescope -- recently came to the same conclusion. Using different methods, the independent teams found young stars spiraling into the center of a massive star cluster called NGC 346 in the Small Magellanic Cloud. This river-like motion of gas and stars is an efficient way to fuel star birth, researchers say. The teams' results show that the process of star formation in the Small Magellanic Cloud is similar to that in our own Milky Way.

Nature likes spirals -- from the whirlpool of a hurricane, to pinwheel-shaped protoplanetary disks around newborn stars, to the vast realms of spiral galaxies across our universe.

Now astronomers are bemused to find young stars that are spiraling into the center of a massive cluster of stars in the Small Magellanic Cloud, a satellite galaxy of the Milky Way.

The outer arm of the spiral in this huge, oddly shaped stellar nursery called NGC 346 may be feeding star formation in a river-like motion of gas and stars. This is an efficient way to fuel star birth, researchers say.

The Small Magellanic Cloud has a simpler chemical composition than the Milky Way, making it similar to the galaxies found in the younger universe, when heavier elements were more scarce. Because of this, the stars in the Small Magellanic Cloud burn hotter and so run out of their fuel faster than in our Milky Way.

Though a proxy for the early universe, at 200,000 light-years away the Small Magellanic Cloud is also one of our closest galactic neighbors.

Learning how stars form in the Small Magellanic Cloud offers a new twist on how a firestorm of star birth may have occurred early in the universe's history, when it was undergoing a "baby boom" about 2 to 3 billion years after the big bang (the universe is now 13.8 billion years old).

The new results find that the process of star formation there is similar to that in our own Milky Way.

Only 150 light-years in diameter, NGC 346 boasts the mass of 50,000 Suns. Its intriguing shape and rapid star formation rate has puzzled astronomers. It took the combined power of NASA's Hubble Space Telescope and the European Southern Observatory's Very Large Telescope (VLT) to unravel the behavior of this mysterious-looking stellar nesting ground.

"Stars are the machines that sculpt the universe. We would not have life without stars, and yet we don't fully understand how they form," explained study leader Elena Sabbi of the Space Telescope Science Institute in Baltimore. "We have several models that make predictions, and some of these predictions are contradictory. We want to determine what is regulating the process of star formation, because these are the laws that we need to also understand what we see in the early universe."

Researchers determined the motion of the stars in NGC 346 in two different ways. Using Hubble, Sabbi and her team measured the changes of the stars' positions over 11 years. The stars in this region are moving at an average velocity of 2,000 miles per hour, which means that in 11 years they move 200 million miles. This is about 2 times the distance between the Sun and the Earth.

But this cluster is relatively far away, inside a neighboring galaxy. This means the amount of observed motion is very small and therefore difficult to measure. These extraordinarily precise observations were possible only because of Hubble's exquisite resolution and high sensitivity. Also, Hubble's three-decade-long history of observations provides a baseline for astronomers to follow minute celestial motions over time.

The second team, led by Peter Zeidler of AURA/STScI for the European Space Agency, used the ground-based VLT's Multi Unit Spectroscopic Explorer (MUSE) instrument to measure radial velocity, which determines whether an object is approaching or receding from an observer.

"What was really amazing is that we used two completely different methods with different facilities and basically came to the same conclusion, independent of each other," said Zeidler. "With Hubble, you can see the stars, but with MUSE we can also see the gas motion in the third dimension, and it confirms the theory that everything is spiraling inwards."

But why a spiral?

"A spiral is really the good, natural way to feed star formation from the outside toward the center of the cluster," explained Zeidler. "It's the most efficient way that stars and gas fueling more star formation can move towards the center."

Half of the Hubble data for this study of NGC 346 is archival. The first observations were taken 11 years ago. They were recently repeated to trace the motion of the stars over time. Given the telescope's longevity, the Hubble data archive now contains more than 32 years of astronomical data powering unprecedented, long-term studies.

Read more at Science Daily

Surprise finding suggests 'water worlds' are more common than we thought

Water is the one thing all life on Earth needs, and the cycle of rain to river to ocean to rain is an essential part of what keeps our planet's climate stable and hospitable. When scientists talk about where to search for signs of life throughout the galaxy, planets with water are always at the top of the list.

A new study suggests that many more planets may have large amounts of water than previously thought -- as much as half water and half rock. The catch? All that water is probably embedded in the rock, rather than flowing as oceans or rivers on the surface.

"It was a surprise to see evidence for so many water worlds orbiting the most common type of star in the galaxy," said Rafael Luque, first author on the new paper and a postdoctoral researcher at the University of Chicago. "It has enormous consequences for the search for habitable planets."

Planetary population patterns

Thanks to better telescope instruments, scientists are finding signs of more and more planets in distant solar systems. A larger sample size helps scientists identify demographic patterns -- similar to how looking at the population of an entire town can reveal trends that are hard to see at an individual level.

Luque, along with co-author Enric Pallé of the Institute of Astrophysics of the Canary Islands and the University of La Laguna, decided to take a population-level look at a group of planets that are seen around a type of star called an M-dwarf. These stars are the most common stars we see around us in the galaxy, and scientists have catalogued dozens of planets around them so far.

But because stars are so much brighter than their planets, we cannot see the actual planets themselves. Instead, scientists detect faint signs of the planets' effects on their stars -- the shadow created when a planet crosses in front of its star, or the tiny tug on a star's motion as a planet orbits. That means many questions remain about what these planets actually look like.

"The two different ways to discover planets each give you different information," said Pallé. By catching the shadow created when a planet crosses in front of its star, scientists can find the diameter of the planet. By measuring the tiny gravitational pull that a planet exerts on a star, scientists can find its mass.

By combining the two measurements, scientists can get a sense of the makeup of the planet. Perhaps it's a big-but-airy planet made mostly out of gas like Jupiter, or a small, dense, rocky planet like Earth.

These analyses had been done for individual planets, but much more rarely for the entire known population of such planets in the Milky Way galaxy. As the scientists looked at the numbers -- 43 planets in all -- they saw a surprising picture emerging.

The densities of a large percentage of the planets suggested that they were too light for their size to be made up of pure rock. Instead, these planets are probably something like half rock and half water, or another lighter molecule. Imagine the difference between picking up a bowling ball and a soccer ball: they're roughly the same size, but one is made up of much lighter material.

Searching for water worlds

It may be tempting to imagine these planets like something out of Kevin Costner's Waterworld: entirely covered in deep oceans. However, these planets are so close to their suns that any water on the surface would exist in a supercritical gaseous phase, which would enlarge their radius. "But we don't see that in the samples," explained Luque. "That suggests the water is not in the form of surface ocean."

Instead, the water could exist mixed into the rock or in pockets below the surface. Those conditions would be similar to Jupiter's moon Europa, which is thought to have liquid water underground.

"I was shocked when I saw this analysis -- I and a lot of people in the field assumed these were all dry, rocky planets," said UChicago exoplanet scientist Jacob Bean, whose group Luque has joined to conduct further analyses.

The finding matches a theory of exoplanet formation that had fallen out of favor in the past few years, which suggested that many planets form farther out in their solar systems and migrate inward over time. Imagine clumps of rock and ice forming together in the cold conditions far from a star, and then being pulled slowly inward by the star's gravity.

Read more at Science Daily

Modern humans generate more brain neurons than Neanderthals

The question of what makes modern humans unique has long been a driving force for researchers. Comparisons with our closest relatives, the Neanderthals, therefore provide fascinating insights. The increase in brain size, and in neuron production during brain development, are considered to be major factors for the increased cognitive abilities that occurred during human evolution. However, while both Neanderthals and modern humans develop brains of similar size, very little is known about whether modern human and Neanderthal brains may have differed in terms of their neuron production during development.

Researchers from the Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG) in Dresden now show that the modern human variant of the protein TKTL1, which differs by only a single amino acid from the Neanderthal variant, increases one type of brain progenitor cells, called basal radial glia, in the modern human brain. Basal radial glial cells generate the majority of the neurons in the developing neocortex, a part of the brain that is crucial for many cognitive abilities. As TKTL1 activity is particularly high in the frontal lobe of the fetal human brain, the researchers conclude that this single human-specific amino acid substitution in TKTL1 underlies a greater neuron production in the developing frontal lobe of the neocortex in modern humans than Neanderthals.

Only a small number of proteins have differences in the sequence of their amino acids -- the building blocks of proteins -- between modern humans and our extinct relatives, the Neanderthals and Denisovans. The biological significance of these differences for the development of the modern human brain is largely unknown. In fact, both, modern humans and Neanderthals, feature a brain, and notably a neocortex, of similar size, but whether this similar neocortex size implies a similar number of neurons remains unclear. The latest study of the research group of Wieland Huttner, one of the founding directors of the Max Planck Institute of Molecular Cell Biology and Genetics (MPI-CBG) in Dresden, carried out in collaboration with Svante Pääbo, director at the Max Planck Institute for Evolutionary Anthropology in Leipzig, and Pauline Wimberger of the University Hospital Dresden and their colleagues, addresses just this question. The researchers focus on one of these proteins that presents a single amino acid change in essentially all modern humans compared to Neanderthals, the protein transketolase-like 1 (TKTL1). Specifically, in modern humans TKTL1 contains an arginine at the sequence position in question, whereas in Neanderthal TKTL1 it is the related amino acid lysine. In the fetal human neocortex, TKTL1 is found in neocortical progenitor cells, the cells from which all cortical neurons derive. Notably, the level of TKTL1 is highest in the progenitor cells of the frontal lobe.

Modern human TKTL1, but not Neanderthal TKTL1, leads to more neurons in embryonic mouse neocortex

Anneline Pinson, the lead author of the study and researcher in the group of Wieland Huttner, set out to investigate the significance of this one amino acid change for neocortex development. Anneline and her colleagues introduced either the modern human or the Neanderthal variant of TKTL1 into the neocortex of mouse embryos. They observed that basal radial glial cells, the type of neocortical progenitors thought to be the driving force for a bigger brain, increased with the modern human variant of TKTL1 but not with the Neanderthal variant. As a consequence, the brains of mouse embryos with the modern human TKTL1 contained more neurons.

More neurons in the frontal lobe of modern humans

After this, the researchers explored the relevance of these effects for human brain development. To this end, they replaced the arginine in modern human TKTL1 with the lysine characteristic of Neanderthal TKTL1, using human brain organoids -- miniature organ-like structures that can be grown from human stem cells in cell culture dishes in the lab and that mimic aspects of early human brain development. "We found that with the Neanderthal-type of amino acid in TKTL1, fewer basal radial glial cells were produced than with the modern human-type and, as a consequence, also fewer neurons," says Anneline Pinson. "This shows us that even though we do not know how many neurons the Neanderthal brain had, we can assume that modern humans have more neurons in the frontal lobe of the brain, where TKTL1 activity is highest, than Neanderthals." The researchers also found that modern human TKTL1 acts through changes in metabolism, specifically a stimulation of the pentose phosphate pathway followed by increased fatty acid synthesis. In this way, modern human TKTL1 is thought to increase the synthesis of certain membrane lipids needed to generate the long process of basal radial glial cells that stimulates their proliferation and, therefore, to increase neuron production.

Read more at Science Daily

Changes in the tree canopy facilitated the evolution of the first-ever gliding reptile

Researchers have run through near-perfect fossils of the World's first gliding reptile with a fine-toothed comb and untangled hitherto unknown facets to discover it was a change in tree canopy which likely facilitated such flight in these creatures.

Since the first fossils of Coelurosauravus elivensis were discovered in 1907, there has been spirited debate over how the animal actually lived during the Late Permian Period -- between 260 million to 252 million years ago -- and how its unique body parts fit together.

By piecing together enough fossils to create a near-perfect skeletal reconstruction, new research provides fresh insights into the tetrapod's morphology and its habits; and crucially establishes how it became the first-known reptile to glide.

The answer to the latter derives from the canopy of the forestry in which this unusual creature lived in -- suggest experts from the French National Museum of Natural History, in Paris (or Muséum national d'Histoire naturelle) and the Staatliches Museum für Naturkunde Karlsruhe, in Germany.

Explaining their findings, today, in the peer-reviewed Journal of Vertebrate Paleontology, lead author Valentin Buffa, from the Centre de Recherche en Paléontologie -- Paris at the French Natural History Museum, states: "Pennsylvanian forests, while taxonomically and vertically heterogeneous, had rather open canopy strata with spatially separated arborescent taxa resulting in little crown overlap. In contrast, Cisularian forests show evidence of denser communities suggestive of more continuous canopy strata. Such change in forest structure could explain why no gliders have been reported prior to weigeltisaurids although several arboreal or scansorial amniotes have been described from Pennsylvanian and Cisularian deposits.

"These dragons weren't forged in mythological fire -- they simply needed to get from place to place. As it turned out, gliding was the most efficient mode of transport and here, in this new study, we see how their morphology enabled this."

The team examined three known fossils of C. elivensis, as well as a number of related specimens -- all belonging to the family Weigeltisauridae. Their research focused on the postcranial portion -- the body, including the torso, limbs, and remarkable gliding apparatus, known as the patagium. The latter is the membranous flap spanning the forelimbs and hindlimbs, also found in such living animals as flying squirrels, sugar gliders, and colugos.

Previous analysis of the reptile had assumed that its patagium was supported by bones that extended from the ribs, as they do in modern Draco species of Southeast Asia -- which, to this day, amazes observers with its gliding flights between the rainforest trees it inhabits.

However, this thorough new examination suggests that the patagium of C. elivensis either extended from the gastralia -- an arrangement of bones in the skin that covers the belly of some reptiles, including crocodilians and dinosaurs -- or from the musculature of the trunk. This would mean that the gliding apparatus sat lower on the abdomen than it does in modern gliding lizards.

Combining this finding with others derived from the bone structure observed in the fossils, the researchers came up with a more refined vision of how this agile creature moved through its arboreal habitat.

"Sharp, curved claws and compressed body form support the idea that was perfectly adapted to moving vertically up tree trunks. The similarity in length of the forelimbs and hindlimbs further indicate that it was an expert climber -- their proportional length assisted it in remaining close to the tree's surface, preventing it from pitching and losing its balance. Its long, lean body and whiplike tail, also seen in contemporary arboreal reptiles, further supports this interpretation," adds Valentin Buffa.

Read more at Science Daily

Cravings for fatty foods traced to gut-brain connection

A dieter wrestling with cravings for fatty foods might be tempted to blame their tongue: the delicious taste of butter or ice cream is hard to resist. But new research investigating the source of our appetites has uncovered an entirely new connection between the gut and the brain that drives our desire for fat.

At Columbia's Zuckerman Institute, scientists studying mice found that fat entering the intestines triggers a signal. Conducted along nerves to the brain, this signal drives a desire for fatty foods. Published September 7, 2022, in Nature, the new study raises the possibility of interfering with this gut-brain connection to help prevent unhealthy choices and address the growing global health crisis caused by overeating.

"We live in unprecedented times, in which the overconsumption of fats and sugars is causing an epidemic of obesity and metabolic disorders," said first author Mengtong Li, PhD, a postdoctoral researcher in the lab of the Zuckerman Institute's Charles Zuker, PhD, supported by the Howard Hughes Medical Institute. "If we want to control our insatiable desire for fat, science is showing us that the key conduit driving these cravings is a connection between the gut and the brain."

This new view of dietary choices and health started with previous work from the Zuker lab on sugar. Researchers found that glucose activates a specific gut-brain circuit that communicates to the brain in the presence of intestinal sugar. Calorie-free artificial sweeteners, in contrast, do not have this effect, likely explaining why diet sodas can leave us feeling unsatisfied.

"Our research is showing that the tongue tells our brain what we like, such as things that taste sweet, salty or fatty," said Dr. Zuker, who is also a professor of biochemistry and molecular biophysics and of neuroscience at Columbia's Vagelos College of Physicians and Surgeons. "The gut, however, tells our brain what we want, what we need."

Dr. Li wanted to explore how mice respond to dietary fats: the lipids and fatty acids that every animal must consume to provide the building blocks of life. She offered mice bottles of water with dissolved fats, including a component of soybean oil, and bottles of water containing sweet substances known to not affect the gut but that are initially attractive. The rodents developed a strong preference, over a couple of days, for the fatty water. They formed this preference even when the scientists genetically modified the mice to remove the animals' ability to taste fat using their tongues.

"Even though the animals could not taste fat, they were nevertheless driven to consume it," said Dr. Zuker.

The researchers reasoned that fat must be activating specific brain circuits driving the animals' behavioral response to fat. To search for that circuit, Dr. Li measured brain activity in mice while giving the animals fat. Neurons in one particular region of the brainstem, the caudal nucleus of the solitary tract (cNST), perked up. This was intriguing because the cNST was also implicated in the lab's previous discovery of the neural basis of sugar preference.

Dr. Li then found the communications lines that carried the message to the cNST. Neurons in the vagus nerve, which links the gut to the brain, also twittered with activity when mice had fat in their intestines.

Having identified the biological machinery underlying a mouse's preference for fat, Dr. Li next took a close look at the gut itself: specifically the endothelial cells lining the intestines. She found two groups of cells that sent signals to the vagal neurons in response to fat.

"One group of cells functions as a general sensor of essential nutrients, responding not only to fat, but also to sugars and amino acids," said Dr. Li. "The other group responds to only fat, potentially helping the brain distinguish fats from other substances in the gut."

Dr. Li then went one important step further by blocking the activity of these cells using a drug. Shutting down signaling from either cell group prevented vagal neurons from responding to fat in the intestines. She then used genetic techniques to deactivate either the vagal neurons themselves or the neurons in the cNST. In both cases, a mouse lost its appetite for fat.

"These interventions verified that each of these biological steps from the gut to the brain is critical for an animal's response to fat," said Dr. Li. "These experiments also provide novel strategies for changing the brain's response to fat and possibly behavior toward food."

The stakes are high. Obesity rates have nearly doubled worldwide since 1980. Today, nearly half a billion people suffer from diabetes.

"The overconsumption of cheap, highly processed foods rich in sugar and fat is having a devastating impact on human health, especially among people of low income and in communities of color," said Dr. Zuker. "The better we understand how these foods hijack the biological machinery underlying taste and the gut-brain axis, the more opportunity we will have to intervene."

Scott Sternson, PhD, a professor of neuroscience at University of California, San Diego, who was not involved in the new research highlighted its potential for improving human health.

"This exciting study offers insight about the molecules and cells that compel animals to desire fat," said Dr. Sternson, whose work focuses on how the brain controls appetite. "The capability of researchers to control this desire may eventually lead to treatments that may help combat obesity by reducing consumption of high-calorie fatty foods."

Read more at Science Daily

Two new temperate rocky worlds discovered

An international research team including astronomers at the University of Birmingham, has just announced the discovery of two "super-Earth" planets orbiting LP 890-9, a small, cool star located about 100 light-years from Earth.

The star, also called TOI-4306 or SPECULOOS-2, is the second-coolest star found to host planets, after the famous TRAPPIST-1. This rare discovery is the subject of a forthcoming publication in the journal Astronomy & Astrophysics.

The system's inner planet, called LP 890-9b, is about 30% larger than Earth and completes an orbit around the star in just 2.7 days. This first planet was initially identified as a possible planet candidate by NASA's Transiting Exoplanet Survey Satellite (TESS), a space mission searching for exoplanets orbiting nearby stars. This candidate was confirmed and characterized by the SPECULOOS telescopes (Search for habitable Planets EClipsing ULtra-cOOl Stars), one of which is operated by the University of Birmingham. SPECULOOS researchers then used their telescopes to seek additional transiting planets in the system that would have been missed by TESS.

"TESS searches for exoplanets using the transit method, by monitoring the brightness of thousands of stars simultaneously, looking for slight dimmings that might be caused by planets passing in front of their stars," explains Laetitia Delrez, a postdoctoral researcher at the University of Liège, and the lead author of the article.

"However, a follow-up with ground-based telescopes is often necessary to confirm the planetary nature of the detected candidates and to refine the measurements of their sizes and orbital properties."

This follow-up is particularly important in the case of very cold stars, such as LP 890-9, which emit most of their light in the near-infrared and for which TESS has a rather limited sensitivity.

The telescopes of the SPECULOOS project, installed at ESO's Paranal Observatory in Chile and on the island of Tenerife, are optimised to observe this type of star with high precision, thanks to cameras that are very sensitive in the near-infrared.

"The goal of SPECULOOS is to search for potentially habitable terrestrial planets transiting some of the smallest and coolest stars in the solar neighbourhood, such as the TRAPPIST-1 planetary system, which we discovered in 2016," recalls Michaël Gillon, from the University of Liège, and the principal investigator of the SPECULOOS project. "This strategy is motivated by the fact that such planets are particularly well suited to detailed studies of their atmospheres and to the search for possible chemical traces of life with large observatories, such as the James Webb Space Telescope (JWST)."

The observations of LP 890-9 gathered by SPECULOOS proved fruitful as they not only confirmed the first planet, but they were critical for the detection of a second, previously unknown planet. This second planet, LP 890-9c (renamed SPECULOOS-2c by the SPECULOOS researchers), is similar in size to the first (about 40% larger than Earth) but has a longer orbital period of about 8.5 days. This orbital period, later confirmed with the MuSCAT3 instrument in Hawaii, places the planet in the so-called "habitable zone" around its star.

"The habitable zone is a concept under which a planet with similar geological and atmospheric conditions as Earth, would have a surface temperature allowing water to remain liquid for billions of years" explains Amaury Triaud, a professor of Exoplanetology at University Birmingham and the leader of the SPECULOOS working group that scheduled the observations leading to the discovery of the second planet. "This gives us a license to observe more and find out whether the planet has an atmosphere, and if so, to study its content and assess its habitability."

The next step will be to study the atmosphere of this planet, for example with the JWST, for which LP 890-9c appears to be the second-most favourable target among the potentially habitable terrestrial planets known so far, surpassed only by the TRAPPIST-1 planets (for which Professor Triaud was also co-discoverer).

Read more at Science Daily

Magma and ice

Let's pretend it's the Late Cretaceous, roughly 66 to 100 million years ago. We've got dinosaurs roaming the land and odd-looking early species of birds, although the shark as we know it is already swimming in the prehistoric oceans -- which cover 82% of Earth. Redwood trees and other conifers are making their debut, as are roses and flowering plants, and with them come bees, termites and ants. Most of all, it's warm, volcanically active and humid all over the place with nary an ice sheet in sight.

Except, according to a group of scientists from UC Santa Barbara, University of Oregon and University of Manitoba, icy conditions did exist in the region of the South Pole.

"And it wasn't just a single-valley glacier," said UCSB geologist John Cottle, "it was probably multiple glaciers or a large ice sheet." Contrary to our widely held picture of the Late Cretaceous as "hot everywhere," he said, there's evidence that polar ice existed during that period, even at the height of global greenhouse conditions. The geologists' study is published in the journal Nature Communications.

A Prehistoric Puzzle

Fast-forward to today. Let's pretend we're in Antarctica. It's chilly, it's barren, and we're standing near a large grouping of exposed glassy rock along the Transantarctic Mountains, adjacent to the Ross Ice Shelf, called the Butcher Ridge Igneous Complex (BRIC).

"I actually heard about these rocks when I was a grad student 20 or so years ago, and they're just really weird," Cottle said. Remote, even by today's Antarctic exploration standards, the BRIC is unusual because the rocks' composition and formation are uncharacteristic of nearby rock formations, with, among other things, large amounts of glass and layered alteration that indicates significant physical, chemical or environmental events that changed their mineral composition.

Cottle got the chance to finally sample the BRIC on a recent expedition, and in the process of analyzing how it was formed, he and his team encountered an "unusually large amount of water."

"So you have a really hot rock that interacts with water, and as it cools, incorporates it into the glass," he said. "If you look at the composition, then you can tell something about where that water came from. It can exist as hydroxyl, which tells you that it probably came from the magma, or it could be molecular, which means it is probably external."

What they were expecting to see was that the alteration in the rock was caused by the water already in the magma as it cooled. What they found instead was a record of a climate process that was thought not to have existed at the time.

In their spectroscopic analysis of the samples, the researchers determined that while some of the water indeed originated with magma as it plumed upward from Earth's interior, as the molten rock cooled into glass just beneath the Earth's surface, it also incorporated groundwater.

"We determined that most of the water in these rocks is externally derived," Cottle said. "We then measured the oxygen and hydrogen isotopic composition of the water and it matches very well to the composition of Antarctic snow and ice."

To lock in their result, Cottle and team also conducted argon-argon geochronology to date the rock and its alteration.

"The problem is, these rocks are Jurassic, so about 183 million years old," he said. "So when you measure the alteration, what you don't know is when that happened." They were able to recover the age of the rock (Jurassic), but also found a younger age (Cretaceous). "So when these rocks cooled and were altered," he continued, "it also reset the argon isotope as well, and you can match the age of the alteration to the composition of the alteration."

There are other, similar volcanic rocks roughly 700 km north of the BRIC that also have a Cretaceous alteration age, indicating that polar glaciation might have been regionally extensive in Antarctica during that time. "What we'd like to do is go to other places in Antarctica and see if we can determine the scale of the glaciation, if we recover the same results that we've already found," he said.

Finding evidence of large ice sheets dating back to the Cretaceous might not alter our general picture of a hot and humid Earth at that time, Cottle said, "but we would have to think about the Cretaceous and Antarctica quite differently than we do now."

Read more at Science Daily

Botany: From the soil to the sky

Every day, about one quadrillion gallons of water are silently pumped from the ground to the treetops. Earth's plant life accomplishes this staggering feat using only sunlight. It takes energy to lift all this liquid, but just how much was an open question until this year.

Researchers at UC Santa Barbara have calculated the tremendous amount of power used by plants to move water through their xylem from the soil to their leaves. They found that, on average, it was an additional 14% of the energy the plants harvested through photosynthesis. On a global scale, this is comparable to the production of all of humanity's hydropower. Their study, published in the Journal of Geophysical Research: Biogeosciences, is the first to estimate how much energy goes into lifting water up to plant canopies, both for individual plants and worldwide.

"It takes power to move water up through the xylem of the tree. It takes energy. We're quantifying how much energy that is," said first author Gregory Quetin, a postdoctoral researcher in the Department of Geography. This energy is in addition to what a plant produces via photosynthesis. "It's energy that's being harvested passively from the environment, just through the tree's structure."

Photosynthesis requires carbon dioxide, light and water. CO2 is widely available in the air, but the other two ingredients pose a challenge: Light comes from above, and water from below. So, plants need to bring the water up (sometimes a considerable distance) to where the light is.

More complex plants accomplish this with a vascular system, in which tubes called xylem bring water from the roots to the leaves, while other tubes called phloem move sugar produced in the leaves down to the rest of the plant. "Vascular plants evolving xylem is a huge deal that allowed for trees to exist," Quetin said.

Many animals also have a vascular system. We evolved a closed circulatory system with a heart that pumps blood through arteries, capillaries and veins to deliver oxygen and nutrients around our bodies. "This is a function that many organisms pay a lot for," said co-author Anna Trugman, an assistant professor in the Department of Geography. "We pay for it because we have to keep our hearts beating, and that's probably a lot of our metabolic energy."

Plants could have evolved hearts, too. But they didn't. And it saves them a lot of metabolic energy.

In contrast to animals, plant circulatory systems are open and powered passively. Sunlight evaporates water, which escapes from pores in the leaves. This creates a negative pressure that pulls up the water beneath it. Scientists call this process "transpiration."

In essence, transpiration is merely another way that plants harvest energy from sunlight. It's just that, unlike in photosynthesis, this energy doesn't need to be processed before it can be put to use.

Scientists understand this process fairly well, but no one had ever estimated how much energy it consumes. "I've only seen it mentioned specifically as energy in one paper," co-author Leander Anderegg said, "and it was to say that 'this is a really large number. If plants had to pay for it with their metabolism, they wouldn't work.'"

This particular study grew out of basic curiosity. "When Greg [Quetin]and I were both graduate students, we were reading a lot about plant transpiration," recalled Anderegg, now an assistant professor in the Department of Ecology, Evolution, and Marine Biology. "At some point Greg asked, 'How much work do plants do just lifting water against gravity?'

"I said, 'I have no idea. I wonder if anyone knows?' And Greg said, 'surely we can calculate that.'"

About a decade later, they circled back and did just that. The team combined a global database of plant conductance with mathematical models of sap ascent to estimate how much power the world's plant life devotes to pumping water. They found that the Earth's forests consume around 9.4 petawatt-hours per year. That's on par with global hydropower production, they quickly point out.

This is about 14.2% of the energy that plants take in through photosynthesis. So it's a significant chunk of energy that plants benefit from but don't have to actively process. This free energy passes to the animals and fungi that consume plants, and the animals that consume them, and so on.

Surprisingly, the researchers discovered that fighting gravity accounts for only a tiny fraction of this total. Most of the energy goes into simply overcoming the resistance of a plant's own stem.

These findings may not have many immediate applications, but they help us better understand life on Earth. "The fact that there's a global energy stream of this magnitude that we didn't have quantified, is mildly jarring," Quetin said. "It does seem like a concept that slipped through the cracks."

The energies involved in transpiration seem to fall in between the scales that different scientists examine. It's too big for plant physiologists to consider and too small for scientists who study Earth systems to bother with, so it was forgotten. And it's only within the past decade that scientists have collected enough data on water use and xylem resistance to begin addressing the energy of transpiration at global scales, the authors explained.

Within that time, scientists have been able to refine the significance of transpiration in Earth systems using new observations and models. It affects temperatures, air currents and rainfall, and helps shape a region's ecology and biodiversity. Sap ascent power is a small component of transpiration overall, but the authors suspect it may turn out to be noteworthy given the significant energy involved.

It's still early days, and the team admits there's a lot of work to do in tightening their estimates. Plants vary widely in how conductive their stems are to water flow. Compare a hardy desert juniper with a riverside cottonwood, for instance. "A juniper tree that is very drought adapted has a very high resistance," Anderegg said, "while cottonwoods just live to pump water."

Read more at Science Daily

DNA in Viking feces sheds new light on 55,000-year-old relationship between gut companions

Using stool samples from Viking latrines, researchers at the University of Copenhagen have genetically mapped one of the oldest human parasites -- the whipworm. The mapping reflects the parasite's global spread and its interaction with human beings, a delicate relationship that can make us healthier and ill.

Using fossilized eggs in up to 2500-year-old feces from Viking settlements in Denmark and other countries, researchers at the University of Copenhagen's Department of Plant and Environmental Sciences and the Wellcome Sanger Institute (UK) have made the largest and most in-depth genetic analysis of one of the oldest parasites found in humans -- the whipworm.

The study, published in Nature Communications, presents completely new knowledge about the parasite's development and prehistoric dispersal. This knowledge can be applied in efforts to prevent the parasite's drug resistance and its future spread.

The study suggests that human and parasite have developed a delicate interaction over thousands of years, whereby the parasite tries to stay "under the radar" not to be repelled, which allows it more time to infect new people. From other studies, it is known that the whipworm stimulates the human immune system and the gut microbiome, to the mutual benefit of both host and parasite.

While whipworm (Trichuris trichiura) is now rare in industrialized countries, and most often only causes minor problems among healthy individuals, the parasite is estimated to affect 500 million people in developing countries.

"In people who are malnourished or have impaired immune systems, whipworm can lead to serious illness. Our mapping of the whipworm and its genetic development makes it easier to design more effective anti-worm drugs that can be used to prevent the spread of this parasite in the world's poorest regions," says Professor Christian Kapel of UCPH's Department of Plant and Environmental Sciences.

Fossilized latrine poop from Copenhagen and Viborg

Eggs, not worms, made it possible for researchers to examine the genetic material of thousands-of-years-old whipworms. Due to extremely durable chitin in egg capsules, their internal DNA has been well preserved while the eggs have been buried in moist soil.

By examining fossilized stool samples which were previously discovered in the latrines of Viking settlements in Viborg and Copenhagen, the researchers isolated the eggs under a microscope, sieved them from the stool and subjected them to refined genetic analyses that the researchers have been perfecting for years in previous studies.

"We have known for a long time that we could detect parasite eggs up to 9000 years old under a microscope. Lucky for us, the eggs are designed to survive in soil for long periods of time. Under optimal conditions, even the parasite's genetic material can be preserved extremely well. And some of the oldest eggs that we've extracted some DNA from are 5000 years old. It has been quite surprising to fully map the genome of 1000-year-old well-preserved whipworm eggs in this new study," explains Christian Kapel.

The researchers examined archaeological stool samples from several locations. These ancient genetic samples are compared with contemporary samples obtained from people with whipworms from around the world. Doing so has provided researchers with an overview of the worm's genome and its evolution over ten-thousands of years.

"Unsurprisingly, we can see that the whipworm appears to have spread from Africa to the rest of the world along with humans about 55,000 years ago, following the so-called 'out of Africa' hypothesis on human migration," explains Christian Kapel.

Can live unnoticed in the intestine for months

A whipworm can grow five to seven centimeters in length and live unnoticed in the intestine of a healthy individual for several months. During this time, it lays eggs continuously, which are expelled through feces. In people with weakened immune systems, whipworm can cause a wide range of gastrointestinal diseases, malnutrition and even delay childhood development.

Worms are transmitted via the fecal-oral route, meaning that microscopic parasite eggs in soil can spread to drinking water or food, after which they are ingested through the mouth of a new host.

"The eggs lie in the ground and develop for roughly three months. Once matured, eggs can survive in the wild for even longer, as they wait to be consumed by a new host in whose digestive tract they will then hatch. Their entire life cycle is adapted to survive in soil for as long as possible," explains Christian Kapel.

As such, the golden years for these worms in our part of the world were when our toilet and kitchen conditions, as well as personal hygiene, were significantly different than today.

Read more at Science Daily

Planetary heist: Astronomers show massive stars can steal Jupiter-sized planets

Jupiter-sized planets can be stolen or captured by massive stars in the densely populated stellar nurseries where most stars are born, a new study has found.

Researchers from the University of Sheffield have proposed a novel explanation for the recently discovered B-star Exoplanet Abundance STudy (BEAST) planets. These are Jupiter-like planets at large distances (hundreds of times the distance between the Earth and the Sun) from massive stars.

Until now their formation has been something of a mystery, as massive stars emit large amounts of ultraviolet radiation that stops planets from growing to the size of Jupiter -- the largest planet in our solar system.

Dr Emma Daffern-Powell, Co-author of the study, from the University of Sheffield's Department of Physicsand Astronomy added:"Our previous research has shown that in stellar nurseries stars can steal planets from other stars, or capture what we call 'free-floating' planets. We know that massive stars have more influence in these nurseries than Sun-like stars, and we found that these massive stars can capture or steal planets -- which we call 'BEASTies'.

"Essentially, this is a planetary heist. We used computer simulations to show that the theft or capture of these BEASTies occurs on average once in the first 10 million years of the evolution of a star-forming region."

Dr Richard Parker, Lecturer in Astrophysics in the University of Sheffield's Department of Physics and Astronomy explains: "The BEAST planets are a new addition to the myriad of exoplanetary systems, which display incredible diversity, from planetary systems around Sun-like stars that are very different to our Solar System, to planets orbiting evolved or dead stars

"The BEAST collaboration has discovered at least two super-Jovian planets orbiting massive stars. Whilst planets can form around massive stars, it is hard to envisage gas giant planets like Jupiter and Saturn being able to form in such hostile environments, where radiation from the stars can evaporate the planets before they fully form.

"However, our simulations show that these planets can be captured or stolen, on orbits very similar to those observed for the BEASTies. Our results lend further credence to the idea that planets on more distant orbits (more than 100 times the distance from Earth to Sun) may not be orbiting their parent star."

Read more at Science Daily

Environmental impacts of 57,000 common store-bought food products

We're all capable of slowing down the effects of a warming Earth, and it could be as simple as how we stock our pantries.

An international team of scientists has evaluated the environmental impacts of more than 57,000 food products -- the stuff you typically find as you wander the aisles of your local grocery. If this type of information is made easily available to the public, they say, it could not only enable the transition to a more sustainable food system, but chances are it could also improve people's health.

"The goal is to have a simpler, and more rigorous quantitative way to inform consumers about the tens of thousands of different items they might buy in a grocery store," said ecologist David Tilman, a professor at UC Santa Barbara's Bren School of Environmental Science & Management, and also at the University of Minnesota's College of Biological Sciences. Tilman is a co-author of a study that appears in the Proceedings of the National Academies of Science.

According to the researchers' assessment, beef and lamb take the greatest toll on the environment, with impacts far outpacing those of other proteins such as chicken, fish and seafood and nuts, which also are on the higher end of the environmental impact scale.

"Many people consider beef to taste good, and I understand why, but it is a very inefficient way to create food for humans," Tilman said. Meanwhile, processed drinks such as soda and energy drinks were rated at the lowest impact level of food products evaluated, sharing space with plant-based grocery foods such as rice and flatbreads.

A Decade of Studying Food Products

While much research has gone into the environmental impacts of food commodities such as fruits, wheat and beef, most food products contain many different ingredients, each of which have taken their own routes to become part of that product. This lifecycle data, which informs the total environmental impacts of producing, harvesting, transporting and processing of said ingredients, are largely invisible to the consumer, as are the proportions of ingredients. According to the study, this information gap exists because "the exact amount of each ingredient and their supply chain in each food product are often considered a trade secret." The sheer number of food products and their variety makes the assessment a "daunting" task for food companies and for retailers aiming to reduce their carbon emissions.

To overcome these limitations, the researchers, led by first author Michael Clark of Oxford University, used prior knowledge from ingredient lists to infer the composition of each ingredient. They then paired this information with environmental databases to gauge impacts across four indicators: greenhouse gas emissions, land use, water stress and eutrophication potential (the magnitude of excess nutrients from production that can pollute surrounding environment and waterways).

"This is the result of a decade since Mike and I started working on this," said Tilman, who is Clark's former advisor. "It started with doing some of the lifecycles ourselves, then using many of these lifecycles that were published. And then we started critically evaluating the quality of lifecycle data available for each of the major food commodities." They consulted previously published papers, conducted further analyses and used their approach on 57,000 food products found in Tesco supermarkets, a major grocery chain in the United Kingdom and Ireland.

"You go to a grocery store in Europe and it doesn't look very different from a grocery store in the United States," Tilman said. While humans around the world don't have the exact same taste preferences, he added, we tend to have to similar tastes, which results in more or less the same kind of food products in our stores.

These tastes tend to gravitate to foods that contain high levels of sugar. It's a commodity that is both cheap and produced in abundance, with effects that have led to increased rates of obesity, diabetes and other conditions related to overconsumption of highly processed foods that often contain high fructose corn syrup.

"That's what happened with the Green Revolution," Tilman said of an unintended consequence of the world's move in the 1950s and '60s toward high-yield, industrial farming processes that include pesticides, fertilizers and monocultures. "Sugar is cheap. Fats are cheap and salt is cheap. People love salty, fatty and sweet kinds of foods; that's what our taste preferences are. They made total sense during our evolutionary past, and now that these foods are so cheap and readily available, we eat them in excess."

Healthy Choices = Healthy Earth

In a previous study, Tilman and Clark found that in general, diets that included healthy, less-processed foods were also heathier for the environment. "We know there's a relationship there, and we wanted to apply this for individual foods," Tilman said. As a result, the researchers' current study also ranks grocery foods by nutritional impact, with plant-based, less processed foods on the healthier end of the scale for both humans and the environment, and highly processed grains and dairy products toward the less-healthy end.

"The healthiest diets that we know of are variants on the classical Mediterranean diet, which has many servings of fruits and vegetables a day, and whole grains," Tilman said. "Whole grain has the advantage of having fiber, which helps slow the rate at which starch becomes sugars." The main meat is fish, he added, with other meats used as flavoring and on special occasions. Other environmentally friendly and nutritious diets include vegetarian and pescatarian diets, provided hydrogenated fats and sugars are kept to a minimum. There isn't enough scientific data yet to put the vegan diet in the same group, but Tilman suspects it belongs there as well.

Still, more work needs to be done to refine the researchers' assessment. There's a lot of variability in the proportion and type of ingredients in similar grocery store foods that can lead to differences in health and environmental impacts, and there are also alternative processes to consider, Tilman said. But the hope is that this information becomes widely available, empowering consumers to make better food choices for the health of both their bodies and the environment.

Read more at Science Daily

How a single protein could unlock age-related vision loss

Research led by Sanford Burnham Prebys professor Francesca Marassi, Ph.D., is helping to reveal the molecular secrets of macular degeneration, which causes almost 90% of all age-related vision loss. The study, published recently in the Biophysical Journal, describes the flexible structure of a key blood protein involved in macular degeneration and other age-related diseases, such as Alzheimer's and atherosclerosis.

"Proteins in the blood are under constant and changing pressure because of the different ways blood flows throughout the body," says Marassi. "For example, blood flows more slowly through small blood vessels in the eyes compared to larger arteries around the heart. Blood proteins need to be able to respond to these changes, and this study gives us fundamental truths about how they adapt to their environment, which is critical to targeting those proteins for future treatments."

There are hundreds of proteins in our blood, but the researchers focused on vitronectin, one of the most abundant. In addition to circulating in high concentrations in the blood, vitronectin is found in the scaffolding between cells and is also an important component of cholesterol.

Vitronectin is a key player in many age-related diseases, but for Marassi's team, the most promising target is macular degeneration, which affects as many as 11 million people in the United States. This number is expected to double by 2050.

"This protein is an important target for macular degeneration because it accumulates in the back of the eye, causing vision loss. Similar deposits appear in the brain in Alzheimer's disease and in the arteries in atherosclerosis," says Marassi. "We want to understand why this happens and leverage this knowledge to develop new treatments."

To approach this question, the researchers were interested in learning how the protein changes its structure at different temperatures and under different levels of pressure, approximating what happens in the human body.

"Determining the structure of a protein is the most important part of determining its function," adds Marassi. Through detailed biochemical analysis, the researchers found that the protein can subtly change its shape under pressure. These changes cause it to bond more easily to calcium ions in the blood, which the researchers suggest leads to the buildup of calcified plaque deposits characteristic of macular degeneration and other age-related diseases.

"It's a very subtle rearrangement of the molecular structure, but it has a big impact on how the protein functions," says Marassi. "The more we learn about the protein on a structural and mechanistic level, the better chance we have of successfully targeting it with treatments."

These structural insights will streamline the development of treatments for macular degeneration because it will allow researchers and their partners in the biotech industry to custom-design antibodies that selectively block the protein's calcium binding without disrupting its other important functions in the body.

Read more at Science Daily

Walking and slithering aren't as different as you think

Abrahamic texts treat slithering as a special indignity visited on the wicked serpent, but evolution may draw a more continuous line through the motion of swimming microbes, wriggling worms, skittering spiders and walking horses.

A new study found that all of these kinds of motion are well represented by a single mathematical model.

"This didn't come out of nowhere -- this is from our real robot data," said Dan Zhao, first author of the study in the Proceedings of the National Academy of Sciences and a recent Ph.D. graduate in mechanical engineering at the University of Michigan.

"Even when the robot looks like it's sliding, like its feet are slipping, its velocity is still proportional to how quickly it's moving its body."

Unlike the dynamic motion of gliding birds and sharks and galloping horses -- where speed is driven, at least in part, by momentum -- every bit of speed for ants, centipedes, snakes and swimming microbes is driven by changing the shape of the body. This is known as kinematic motion.

The expanded understanding of kinematic motion could change the way roboticists think about programming many-limbed robots, opening new possibilities for walking planetary rovers, for instance.

Shai Revzen, professor of electrical and computer engineering at U-M and senior author of the study, explained that two- and four-legged robots are popular because more legs are extremely complex to model using current tools.

"This never sat well with me because my work was on cockroach locomotion," Revzen said. "I can tell you many things about cockroaches. One of them is that they're not brilliant mathematicians."

And if cockroaches can walk without solving extremely complex equations, there has to be an easier way to program walking robots. The new finding offers a place to start.

Slipping feet complicates typical motion models for robots, and the assumption was that it might add an element of momentum to the motion of many-legged robots. But in the model reported by the U-M team, it is not so different from lizards that "swim" in sand or microbes swimming in water.

Because microbes are small, the water seems a lot thicker and stickier -- as if a human was trying to swim in honey. In all of these cases, the limbs move through the surrounding medium, or slide over a surface, rather than being connected at a stationary point.

The team discovered the connection by taking a known model that describes swimming microbes and then reconfiguring it to use with their multi-legged robots. The model reliably reflected their data, which came from multipods -- modular robots that can operate with 6 to 12 legs -- and a six-legged robot called BigAnt.

The team also collaborated with Glenna Clifton, assistant professor of biology at the University of Portland in Oregon, who provided data on ants walking on a flat surface. While the robot legs slip a lot -- up to 100% of the time for the multipods -- ant feet have much firmer connections with the ground, slipping only 4.7% of the time.

Even so, the ants and robots followed the same equations, with their speeds proportional to how quickly they moved their legs. It turned out that this kind of slipping didn't alter the kinematic nature of the motion.

As for what this suggests about how walking evolved, the team points to the worm believed to be the last common ancestor for all creatures that have two sides that are mirror images of each other. This worm, wriggling through water, already had the foundations of the motion that enabled the first animals to walk on land, they propose. Even humans begin learning to propel ourselves kinematically, crawling on hands and knees with the three points of contact on the ground at any time.

The skills of managing momentum -- running with four legs or fewer, walking or running on two legs, flying or gliding -- ladder on top of that older knowledge about how to move, the researchers suggest.

Read more at Science Daily

Martian rock-metal composite shows potential of 3D printing on Mars

A small amount of simulated crushed Martian rock mixed with a titanium alloy made a stronger, high-performance material in a 3D-printing process that could one day be used on Mars to make tools or rocket parts. The parts were made by Washington State University researchers with as little as 5% up to 100% Martian regolith, a black powdery substance meant to mimic the rocky, inorganic material found on the surface of the red planet. While the parts with 5% Martian regolith were strong, the 100% regolith parts proved brittle and cracked easily. Still, even high-Martian content materials would be useful in making coatings to protect equipment from rust or radiation damage.

A little Martian dust appears to go a long way. A small amount of simulated crushed Martian rock mixed with a titanium alloy made a stronger, high-performance material in a 3D-printing process that could one day be used on Mars to make tools or rocket parts.

The parts were made by Washington State University researchers with as little as 5% up to 100% Martian regolith, a black powdery substance meant to mimic the rocky, inorganic material found on the surface of the red planet.

While the parts with 5% Martian regolith were strong, the 100% regolith parts proved brittle and cracked easily. Still, even high-Martian content materials would be useful in making coatings to protect equipment from rust or radiation damage, said Amit Bandyopadhyay, corresponding author on the study published in the International Journal of Applied Ceramic Technology.

"In space, 3D printing is something that has to happen if we want to think of a manned mission because we really cannot carry everything from here," said Bandyopadhyay, a professor in WSU's School of Mechanical and Materials Engineering. "And if we forgot something, we cannot come back to get it."

Bringing materials into space can be extremely expensive. For instance, the authors noted it costs about $54,000 for the NASA space shuttle to put just one kilogram of payload (about 2.2 pounds) into Earth orbit. Anything that can be made in space, or on planet, would save weight and money -- not to mention if something breaks, astronauts would need a way to repair it on site.

Bandyopadhyay first demonstrated the feasibility of this idea in 2011 when his team used 3D-printing to manufacture parts from lunar regolith, simulated crushed moon rock, for NASA. Since then, space agencies have embraced the technology, and International Space Station has its own 3D-printers to manufacture needed materials on site and for experiments.

For this study, Bandyopadhyay along with graduate students Ali Afrouzian and Kellen Traxel, used a powder-based 3D printer to mix the simulated Martian rock dust with a titanium alloy, a metal often used in space exploration for its strength and heat-resistant properties. As part of the process, a high-powered laser heated the materials to over 2,000 degrees Celsius (3,632 F). Then, the melted mix of Martian regolith-ceramic and metal material flowed onto a moving platform that allowed the researchers to create different sizes and shapes. After the material cooled down, the researchers tested it for strength and durability.

The ceramic material made from 100% Martian rock dust cracked as it cooled, but as Bandyopadhyay pointed out it could still make good coatings for radiation shields as cracks do not matter in that context. But just a little Martian dust, the mixture with 5% regolith, not only did not crack or bubble but also exhibited better properties than the titanium alloy alone, which meant it could be used to make lighter weight pieces that could still bear heavy loads.

"It gives you a better, higher strength and hardness material, so that can perform significantly better in some applications," he said.

This study is just a start, Bandyopadhyay said, and future research may yield better composites using different metals or 3D-printing techniques.

Read more at Science Daily

Bees use patterns -- not just colors -- to find flowers

Honeybees rely heavily on flower patterns -- not just colours -- when searching for food, new research shows.

A team led by the University of Exeter tested bee behaviour and built bee's-eye-view simulations to work out how they see flowers.

Honeybees have low-resolution vision (about 100 times lower than human vision), so they can only see a flower's pattern clearly when they are within few centimetres.

However, the new study shows bees can very effectively distinguish between different flowers by using a combination of colour and pattern.

In a series of tests, bees rarely ignored pattern -- suggesting colour alone does not lead them to flowers.

This may help to explain why some colours that are visible to bees are rarely produced by flowers in nature.

"We analysed a large amount of data on plants and bee behaviour," said Professor Natalie Hempel de Ibarra, from Exeter's Centre for Research in Animal Behaviour.

"By training and testing bees using artificial patterns of shape and colour, we found they relied flexibly on their ability to see both of these elements.

"Showing how insects see colour and learn colour patterns is important to understand how pollinators may, or may not, create evolutionary 'pressures' on the colours and patterns that flowers have evolved.

"Our findings suggest that flowers don't need to evolve too many different petal colours, because they can use patterns to diversify their displays so bees can tell them apart from other flowers."

One consistent feature identified in the study is that the outside edges of flowers usually contrast strongly with the plant's foliage -- while the centre of the flower does not have such a strong contrast with the foliage colour.

This could help bees quickly identify colour differences and navigate to flowers.

While flowers may be beautiful to humans, Professor Hempel de Ibarra stressed that understanding more about bees -- and the threats they face -- meant we need to see the world "through the eyes of a bee and the mind of a bee."

Read more at Science Daily

How tardigrades bear dehydration

Some species of tardigrades, or water bears as the tiny aquatic creatures are also known, can survive in different environments often hostile or even fatal to most forms of life. For the first time, researchers describe a new mechanism that explains how some tardigrades can endure extreme dehydration without dying. They explored proteins that form a gel during cellular dehydration. This gel stiffens to support and protect the cells from mechanical stress that would otherwise kill them. These proteins have also been shown to work in insect cells and even show limited functionality in human cultured cells.

Tardigrades often draw attention to themselves, despite being so tiny. Their uncanny ability to survive in situations that would kill most organisms has captured the public’s imagination. One could easily imagine that by decoding their secrets, we could apply the knowledge to ourselves to make humans more resilient to extreme temperatures, pressures, and even dehydration. This is just science fiction for now, but nevertheless, researchers, also captivated by the microscopic creatures, seek to understand the mechanisms responsible for their robustness, as this could bring other benefits too.

“Although water is essential to all life we know of, some tardigrades can live without it potentially for decades. The trick is in how their cells deal with this stress during the process of dehydration,” said Associate Professor Takekazu Kunieda from the University of Tokyo’s Department of Biological Sciences. “It’s thought that as water leaves a cell, some kind of protein must help the cell maintain physical strength to avoid collapsing in on itself. After testing several different kinds, we have found that cytoplasmic-abundant heat soluble (CAHS) proteins, unique to tardigrades, are responsible for protecting their cells against dehydration.”

Recent research into CAHS proteins reveals that they can sense when the cell encapsulating them becomes dehydrated, and that’s when they kick into action. CAHS proteins form gel-like filaments as they dry out. These form networks that support the shape of the cell as it loses its water. The process is reversible, so as the tardigrade cells become rehydrated, the filaments recede at a rate that doesn’t cause undue stress on the cell. Interestingly though, the proteins exhibited the same kind of action even when isolated from tardigrade cells.

“Trying to see how CAHS proteins behaved in insect and human cells presented some interesting challenges,” said lead author Akihiro Tanaka, a graduate student in the lab. “For one thing, in order to visualize the proteins, we needed to stain them so they show up under our microscopes. However, the typical staining method requires solutions containing water, which obviously confounds any experiment where water concentration is a factor one seeks to control for. So we turned to a methanol-based solution to get around this problem.”

Research on mechanisms related to dry preservation of cells or organisms could have many future applications. Kunieda and his team hope that through this new knowledge, researchers might find ways to improve the preservation of cell materials and biomolecules in a dry state. This could extend the shelf life of materials used for research, medicines with short expiry dates, or maybe even whole organs needed for transplants.

“Everything about tardigrades is fascinating. The extreme range of environments some species can survive leads us to explore never-before-seen mechanisms and structures. For a biologist, this field is a gold mine,” said Kunieda. “I’ll never forget New Year’s Day 2019, when I received an email from Tomomi Nakano, another author of the paper. She had been working late trying to see the condensation of CAHS proteins and observed the first CAHS filament networks in human cultured cells. I was astonished at seeing such clearly defined microscopic images of these. It was the first time I had seen such a thing. It was a very happy new year indeed!”

Read more at Science Daily

Faster in the Past: New seafloor images of West Antarctic Ice Sheet upend understanding of Thwaites Glacier retreat

The Thwaites Glacier in West Antarctica -- about the size of Florida -- has been an elephant in the room for scientists trying to make global sea level rise predictions.

This massive ice stream is already in a phase of fast retreat (a "collapse" when viewed on geological timescales) leading to widespread concern about exactly how much, or how fast, it may give up its ice to the ocean.

The potential impact of Thwaites' retreat is spine-chilling: a total loss of the glacier and surrounding icy basins could raise sea level from three to 10 feet.

A new study in Nature Geoscience led by marine geophysicist Alastair Graham at the University of South Florida's College of Marine Science adds cause for concern. For the first time, scientists mapped in high-resolution a critical area of the seafloor in front of the glacier that gives them a window into how fast Thwaites retreated and moved in the past.

The stunning imagery shows geologic features that are new to science, and also provides a kind of crystal ball to see into Thwaites' future. In people and ice sheets alike, past behavior is key to understanding future behavior.

The team documented more than 160 parallel ridges that were created, like a footprint, as the glacier's leading edge retreated and bobbed up and down with the daily tides.

"It's as if you are looking at a tide gauge on the seafloor," Graham said. "It really blows my mind how beautiful the data are."

Beauty aside, what's alarming is that the rate of Thwaites' retreat that scientists have documented more recently are small compared to the fastest rates of change in its past, said Graham.

To understand Thwaites' past retreat, the team analyzed the rib-like formations submerged 700 meters (just under half a mile) beneath the polar ocean and factored in the tidal cycle for the region, as predicted by computer models, to show that one rib must have been formed every single day.

At some point in the last 200 years, over a duration of less than six months, the front of the glacier lost contact with a seabed ridge and retreated at a rate of more than 2.1 kilometers per year (1.3 miles per year) -- twice the rate documented using satellites between 2011 and 2019.

"Our results suggest that pulses of very rapid retreat have occurred at Thwaites Glacier in the last two centuries, and possibly as recently as the mid-20th Century," Graham said.

"Thwaites is really holding on today by its fingernails, and we should expect to see big changes over small timescales in the future-even from one year to the next-once the glacier retreats beyond a shallow ridge in its bed," said marine geophysicist and study co-author Robert Larter from the British Antarctic Survey.

To collect the imagery and supporting geophysical data, the team, which included scientists from the United States, the United Kingdom and Sweden, launched a state-of-the-art orange robotic vehicle loaded with imaging sensors called 'Rán'from the R/V Nathaniel B. Palmer during an expedition in 2019.

Rán, operated by scientists at the University of Gothenburg in Sweden, embarked on a 20-hour mission that was as risky as it was serendipitous, Graham said. It mapped an area of the seabed in front of the glacier about the size of Houston -- and did so in extreme conditions during an unusual summer notable for its lack of sea ice.

This allowed scientists to access the glacier front for the first time in history.

"This was a pioneering study of the ocean floor, made possible by recent technological advancements in autonomous ocean mapping and a bold decision by the Wallenberg foundation to invest into this research infrastructure," said Anna Wåhlin, a physical oceanographer from the University of Gothenburg who deployed Rán at Thwaites. "The images Ran collected give us vital insights into the processes happening at the critical junction between the glacier and the ocean today."

"It was truly a once in a lifetime mission," said Graham, who said the team would like to sample the seabed sediments directly so they can more accurately date the ridge-like features.

"But the ice closed in on us pretty quickly and we had to leave before we could do that on this expedition," he said.

While many questions remain, one thing's for sure: It used to be that scientists thought of the Antarctic ice sheets as sluggish and slow to respond, but that's simply not true, said Graham.

"Just a small kick to Thwaites could lead to a big response," he said.

According to the United Nations, roughly 40 percent of the human population lives within 60 miles of the coast.

"This study is part of a cross-disciplinary collective effort to understand the Thwaites Glacier system better," said Tom Frazer, dean of the USF College of Marine Science, "and just because it's out of sight, we can't have Thwaites out of mind. This study is an important step forward in providing essential information to inform global planning efforts."

Read more at Science Daily

Astronomers show how terrain evolves on icy comets

With an eye toward a possible return mission years in the future, Cornell University astronomers have shown how smooth terrains -- a good place to land a spacecraft and to scoop up samples -- evolve on the icy world of comets.

By applying thermal models to data gathered by the Rosetta mission -- which caught up to the barbell-shaped Comet 67P/Churyumov-Gerasimenko almost a decade ago -- they show that the topography influences the comet's surface activity across hundreds of meters.

"You can have a uniform surface composition on comets and still have hotspots of activity," said lead author Abhinav S. Jindal, a graduate student in astronomy and member of the research group of Alexander Hayes, associate professor of astronomy. "The topography is driving the activity."

Comets are icy bodies made of dust, rocks and gas left over from the solar system's formation about 4.6 billion years ago, Jindal said. They form in the solar system's outer fringes and have spent eternity cruising through the dark, cosmic freezer of space, far from the sun's heat.

"Their chemistry has not changed much from when comets formed, making them 'time capsules' preserving primordial material from the birth of the solar system," Jindal said, explaining that these bodies likely seeded early Earth with water and key building blocks of life.

"As some of these comets have been pulled into the inner solar system," he said, "their surfaces undergo changes. Science is trying to understand the driving processes."

As Comet 67P loops its way back toward the sun, the body speeds by it to a point called perihelion -- its closest approach -- and the comet warms up. The Rosetta mission followed the comet as it rounded the sun and studied its activity. The smooth terrains serve as locations where the most changes were observed, making them key to grasping the surface's evolution.

Jindal and the researchers examined the evolution of 16 topographic depressions in the Imhotep region -- the largest smooth terrain deposit on 67P -- between June 5, 2015, when activity was first observed, and Dec. 6, 2015, when the final large-scale changes were observed.

The comet went through a process called sublimation -- in which the icy parts turned gaseous in the sun's heat. The comet's smooth Imhotep region showed a complex pattern of simultaneous eroding scarps (the steep edges of arc-shaped depressions) and material deposition.

Read more at Science Daily

Can 'random noise' unlock our learning potential?

Though many of us may seek a quiet place in which to study, 'noise' may play a key role in helping some people improve their learning potential.

Edith Cowan University (ECU) has investigated the effects of transcranial random noise stimulation (tRNS) in a variety of settings and found the technology could have many applications.

Despite its name, tRNS doesn't utilize noise in the everyday, auditory sense of the word.

Rather, it sees electrodes attached to the head so a weak current can pass through specific parts of the brain.

Study lead Dr Onno van der Groen said the study showed tRNS has promise as a tool to assist people with compromised learning capabilities.

"The effect on learning is promising: it can speed up learning and help people with neurological conditions," Dr van der Groen said.

"So, people with learning difficulties you can use it to enhance learning rate, for example.

"It's also been trialled on people with visual deficits, such as after stroke and traumatic brain injury.

"When you add this type of stimulation during learning, you get better performance, faster learning and better attention afterwards as well."

Forming new pathways

Dr van der Groen said tRNS works by allowing the brain to form new connections and pathways, a process known as neuroplasticity.

"If you learn something, there has to be neuroplastic changes in your brain, which allows you to learn this information," he said.

"And this is a tool to enhance this neuroplasticity."

Dr van der Groen said tRNS had two effects on the brain: the 'acute' effect, which allows a person to perform better while undergoing tRNS, and the modulating effect which saw lasting results.

"If you do 10 sessions of a visual perception task with the tRNS and then come back and do it again without it, you'll find you perform better than the control group who hasn't used it," he said.

"Limitless" potential?

The idea of expanding one's learning potential via tech such as tRNS raises many questions.

While it's most pertinent to those with deficiencies and difficulties in learning, it also begs the question as to whether a neurotypical person can take their intelligence to new levels, similar to the concept in the movie 'Limitless'.

Dr van der Groen says the potential is there, but there are also signs it won't create a 'new level' of intelligence.

"The question is, if you're neurotypical, are you already performing at your peak," he said.

"There's a case study where they tried to enhance the mathematical skills of a super mathematician; with him, it didn't have much of an impact on his performance, presumably because he is already a top performer in that area.

"But it could be used if you're learning something new."

Where it's headed

Though the technology is still in its infancy and people are only able to access tRNS by entering controlled trials, Dr van der Groen said its practicality and apparent safety meant there was a lot of potential for a range of applications.

"The concept is relatively simple," he said.

"It's like a battery: the current runs from plus to minus, but it goes through your head as well.

"We're working on a study where we send the equipment to people, and they apply everything themselves remotely.

"So in that regards, it's quite easy to use."

Scientists worldwide are also investigating tRNS' effects on perception, working memory, sensory processing and other aspects of behaviour, with the technology showing promise as a treatment for a range of clinical conditions.

"We're still trying to find out how best we can use it," Dr van der Groen said.

Read more at Science Daily

Scientists study tourists to protect great apes

Researchers are protecting great apes from diseases by studying the behaviour and expectations of tourists who visit them.

Humans are great apes, and this close genetic link makes non-human great apes (bonobos, chimpanzees, eastern gorillas, western gorillas and orangutans) vulnerable to our infectious diseases.

In the new study, by an international team including the University of Exeter, NOVA University Lisbon and Ugandan NGO Conservation Through Public Health, almost 1,000 tourists or potential future tourists completed an online questionnaire.

Willingness to comply with disease prevention measures like wearing a facemask varied depending on factors such as nationality, expectations about the visitor experience and whether people thought specific disease-risk measures were effective.

The study was conducted in the early stages of the COVID-19 pandemic, when the researchers also created the Protect Great Apes from Disease initiative.

"We have developed visitor education and guide-training materials for use in African sites of great ape tourism," said lead author Dr Ana Nuno, of NOVA University Lisbon and the University of Exeter.

"To do so, we first explored what factors seem to affect visitors' compliance with disease mitigation measures.

"This included asking them about their actions on previous visits, their willingness to comply in future and exploring what factors should be promoted to increase their willingness to follow recommendations.

"To do so, we adapted a tool from the health literature which is commonly used for understanding why individuals may or may not act in the face of a threat to health."

Dr Kim Hockings, from the Centre for Ecology and Conservation on Exeter's Penryn Campus in Cornwall, added: "Through this greater understanding of the visitors to wild African great ape tourism sites, we were able to identify ways of improving measures to reduce disease transmission.

"This is important not only for COVID-19 but other infectious diseases too, particularly at the early stages of future pandemics when information is generally limited but preventive action is required.

"In the face of growing threats from future pandemics, we must minimise disease transmission while ensuring that tourism and research promote long-term support for the conservation of great apes and their habitats as well as maximising benefits for local communities."

The questionnaire was completed by 420 past visitors and 569 potential future visitors (from 58 countries in total) to wild great ape tourism sites in Africa.

When compared to other disease-mitigation measures, visitors expressed less willingness to being vaccinated against COVID-19 (which, at the time the survey was conducted, had only just started being administered to very high-risk groups), wearing a facemask during trekking (although willing when viewing the apes) and quarantine after international travel before visiting great apes.

Believing that each specific measure was effective in preventing disease was key to respondents' willingness to follow that specific recommendation.

Read more at Science Daily

Simple measures can go a long way to combating air pollution in schools

Most UK primary schools experience levels of pollution which exceed the safe levels set out by the World Health Organization, yet simple measures can cut outdoor and indoor exposure of toxins by almost half, according to a new study from the University of Surrey.

Working with a select number of London schools, researchers from Surrey's Global Centre for Clean Air Research (GCARE) investigated whether putting up a green screen along the perimeter fence of a school, installing air purifiers in classrooms, and organising school street initiatives during pick-up and drop-off hours, improved air quality of classrooms and playgrounds. These initiatives were funded by Impact on Urban Health.

The researchers found that air purifiers in classrooms reduced indoor pollution concentrations by up to 57%, and the School Streets initiative, which stops motor vehicles driving past schools at the start and end of school days, reduced particle concentrations by up to 36%. Green screens at the school boundary reduced some of the most dangerous outdoor particle levels coming from roads by up to 44%, depending on wind conditions.

Prashant Kumar, founding Director of the Global Centre for Clean Air Research (GCARE) at the University of Surrey, said:

"Everybody, especially our children, deserves to live and work where the air is as clean and safe as possible. Unfortunately, the reality is far from ideal, with many of our schools unwittingly exposing children to harmful pollutants. The problem is particularly bad at schools near busy roads.

"Our research offers hope to many who care about this issue, as the results show that taking reasonable action can make a positive difference."

Ten million students worldwide spend 30% of their daily lives at school, with 70% of this time being spent indoors. Currently, 7,000 UK schools breach the World Health Organization's air quality limits, leaving children vulnerable to respiratory diseases, affected lung and brain health, behavioural problems, and increased risk of cancer.

Kate Langford, Programme Director of the Health Effects of Air pollution programme at Impact on Urban Health, funders of the research, said:

"Every child has the right to learn in an environment that keeps them safe and healthy. But, every day, children are exposed to dangerously high levels of air pollution in and around schools.

"Our partnership with Arup, Global Action Plan and the University of Surrey has shown there are practical ways that we can protect children in and around schools and can help guide schools to implement these solutions.

"These measures now need to be combined with efforts from local authorities at regional and national levels to improve air quality and create healthier places for children to live, learn and play."

Larissa Lockwood, Director of Clean Air at Global Action Plan, said:

"Schools should be safe places of learning, not places where students are at risk of health hazards. There is no safe level of air pollution, but children are particularly vulnerable to its impacts including the development of organs and their ability to learn. Services like the London Schools Pollution Helpdesk ensure that schools have access to advice on what they can do to reduce exposure to air pollution, including the measures tested in this research. But this needs to be rolled out nationally -- all children must be protected from the health effects of air pollution in their everyday lives."

Professor Prashant Kumar concluded:

"My simple plea to decision-makers in the UK is this: simple actions speak louder than words. By giving every school resources to implement one of the measures detailed in our research, they could make a world of difference to tens of thousands of children in this country."

Read more at Science Daily

Crime-scene technique identifies asteroid sites

Analysing the charred remains of plants can confirm the locations of asteroid strikes in the distant past, new research shows.

Based on estimates of crater-producing asteroid strikes in the last 11,650 years (known as the Holocene), only about 30% of impact sites have been located.

Until now, there has been no way to distinguish between normal land structures and very small asteroid craters unless pieces of iron meteorites were found nearby.

In the new study, an international team of researchers found that charcoal around craters is different from wildfire charcoal -- so analysing samples allows scientists to work out the origin of small craters.

"The properties of organisms turned into charcoal reflect the conditions in which they were killed," said lead author Dr Ania Losiak, from the Institute of Geological Sciences, Polish Academy of Sciences and the University of Exeter.

"Those conditions, such as the heat the wood was exposed to or the duration of the heating, leave tell-tale signs in the material's structure.

"For example, charcoal from low-energy surface fires, like burning bushes and leaves, has different properties than charcoal from high-intensity wildfires.

"Impact charcoals are very strange. They all look as if they were formed in much lower temperatures than wildfire charcoals, and they are all very similar to each other, while in a wildfire it is common to find strongly charred wood just next to barely affected branches."

Dr Losiak worked on the research as part of a Marie Sklodowska-Curie Individual Fellowship at the University of Exeter wildFIRE lab, led by Professor Claire Belcher.

The research team dug trenches in rims of four craters (Kaali Main and Kaali 2/8 in Estonia, Morasko in Poland, and Whitecourt in Canada).

"The differences between wildfire charcoal and impact charcoal proved to be dramatic and surprising," said Professor Belcher, part of Exeter's Global Systems Institute.

"While wildfire charcoal is considerably varied in its reflectivity, depending on the local conditions during the fire, impact charcoals showed uniform characteristics despite coming from completely different locations and being formed thousands of years apart.

"This presents an opportunity for geologists looking for unrecognised impact craters."

Professor Chris Herd, from the University of Alberta, said: "This study improves our understanding of environmental effects of small impact crater formation so that in the future, when we discover an asteroid a few metres across or more coming our way only a couple of weeks before the impact, we will be able to more precisely determine the size and type of evacuation zone necessary."

Read more at Science DailytAnalysing the charred remains of plants can confirm the locations of asteroid strikes in the distant past, new research shows.

Based on estimates of crater-producing asteroid strikes in the last 11,650 years (known as the Holocene), only about 30% of impact sites have been located.

Until now, there has been no way to distinguish between normal land structures and very small asteroid craters unless pieces of iron meteorites were found nearby.

In the new study, an international team of researchers found that charcoal around craters is different from wildfire charcoal -- so analysing samples allows scientists to work out the origin of small craters.

"The properties of organisms turned into charcoal reflect the conditions in which they were killed," said lead author Dr Ania Losiak, from the Institute of Geological Sciences, Polish Academy of Sciences and the University of Exeter.

"Those conditions, such as the heat the wood was exposed to or the duration of the heating, leave tell-tale signs in the material's structure.

"For example, charcoal from low-energy surface fires, like burning bushes and leaves, has different properties than charcoal from high-intensity wildfires.

"Impact charcoals are very strange. They all look as if they were formed in much lower temperatures than wildfire charcoals, and they are all very similar to each other, while in a wildfire it is common to find strongly charred wood just next to barely affected branches."

Dr Losiak worked on the research as part of a Marie Sklodowska-Curie Individual Fellowship at the University of Exeter wildFIRE lab, led by Professor Claire Belcher.

The research team dug trenches in rims of four craters (Kaali Main and Kaali 2/8 in Estonia, Morasko in Poland, and Whitecourt in Canada).

"The differences between wildfire charcoal and impact charcoal proved to be dramatic and surprising," said Professor Belcher, part of Exeter's Global Systems Institute.

"While wildfire charcoal is considerably varied in its reflectivity, depending on the local conditions during the fire, impact charcoals showed uniform characteristics despite coming from completely different locations and being formed thousands of years apart.

"This presents an opportunity for geologists looking for unrecognised impact craters."

Professor Chris Herd, from the University of Alberta, said: "This study improves our understanding of environmental effects of small impact crater formation so that in the future, when we discover an asteroid a few metres across or more coming our way only a couple of weeks before the impact, we will be able to more precisely determine the size and type of evacuation zone necessary."

Read more at Science Daily

From wound healing to regeneration

The phenomenon of regeneration was discovered over 200 years ago in the freshwater polyp Hydra. Until now, however, it was largely unclear how the orderly regeneration of lost tissues or organs is activated after injury. In its investigations of Hydra, an interdisciplinary research team at Heidelberg University was able to show how wound healing signals released upon injury are converted into specific signals of pattern formation and cell differentiation. Essential components are the mitogen-activated protein kinases (MAPK) and the Wnt signalling pathway -- molecular mechanisms that have remained relatively unchanged throughout evolution.

The ability to regenerate varies widely in animals. Most mammals and vertebrates have only limited regeneration capacity, while basal and simple animals that emerged early in evolution, like cnidarians and planarians, can regenerate their whole body. In all cases, the process of regeneration begins with wound healing. The cells at the site of injury proliferate and form an undifferentiated mass -- a blastema -- from which the missing structures are re-patterned. This activates genetic processes that also control embryonic development. To determine the molecular mechanisms involved, the research team led by Prof. Dr Thomas W. Holstein studied the freshwater polyp Hydra to understand the basic features of this activation of regeneration.

The core of their investigations is the doctoral thesis of Anja Tursch. She repeated the key experiment of Geneva naturalist Abraham Trembley (1710 to 1784) which led him to discover the regeneration phenomenon. The Hydra polyp is bisected, prompting the upper half to regenerate a new "head" and the lower half a new "foot" -- hence totally different body parts can grow from the exact same tissue at the cut surface in the middle. Building on their previous work on Hydra regeneration, the researchers at the Centre for Organismal Studies (COS) of Heidelberg University have now shown how this is possible.

Regardless of where it occurs, any damage triggers nonspecific signals for an injury response, i.e. wound healing, via calcium ions and the production of reactive oxygen species. The signals are transmitted intracellularly by three mitogen-activated protein kinases -- p38, JNKs, and ERK. Activation of these three molecules is required for both head and foot regeneration. Wnt signalling pathways are then activated that are important during embryonic development for the formation of rudimentary organs and the body axis. The generic signals of wound healing are thus transferred into position-specific signals of patterning and cell differentiation for regeneration.

"Our experiments show that the Wnt signalling pathway is a main component of the initially general injury response and, depending on signal strength, directs the tissue toward head or foot development," explains Prof. Holstein. This is why, in the case of MAPK inhibition, the otherwise absent regeneration can be induced by artificially generated, recombinant Wnt proteins. "It was also surprising that in middle body parts that had both head and foot removed, heads can be induced at both ends in this way," adds Dr Suat Özbek, a member of Prof. Holstein's "Molecular Evolution and Genomics" research group at the COS.

Read more at Science Daily