Mountain erosion may add CO2 to the atmosphere

A new study found that the process of mountain erosion can be a source of new carbon dioxide gas that can release it back into the atmosphere far faster than it's being absorbed into newly exposed rock. The researchers conducted fieldwork in one of the most erosion-prone mountain chains in the world -- the central range of Taiwan (above).

Scientists have long known that steep mountain ranges can draw carbon dioxide (CO2) out of the atmosphere -- as erosion exposes new rock, it also starts a chemical reaction between minerals on hill slopes and CO2 in the air, "weathering" the rock and using CO2 to produce carbonate minerals like calcite.

A new study led by researchers from the Woods Hole Oceanographic Institution (WHOI), however, has turned this idea on its head. In paper released on April 12th in the journal Science, the scientists announced that the erosion process can also be a source of new CO2 gas, and can release it back into the atmosphere far faster than it's being absorbed into newly-exposed rock.

"This goes against a long-standing hypothesis that more mountains mean more erosion and weathering, which means an added reduction of CO2. It turns out it's much more complicated than that," says Jordon Hemingway, a postdoctoral fellow at Harvard University and lead author on the paper.

The source of this extra CO2 isn't entirely geological. Instead, it's the byproduct of tiny microbes in mountain soils that "eat" ancient sources of organic carbon that are trapped in the rock. As the microbes metabolize these minerals, they spew out carbon dioxide.

The researchers came to this realization after studying one of the most erosion-prone mountain chains in the world -- the central range of Taiwan. This steep-sided range is pummeled by more than three major typhoons each year, each of which mechanically erode the soil and rock through heavy rains and winds.

Hemingway and his colleagues examined samples of soil, bedrock, and river sediments from the central range, looking for telltale signs of organic carbon in the rock. What they found there surprised them.

"At the very bottom of the soil profile, you have basically unweathered rock. As soon as you hit the base of the soil, layer, though, you see rock that's loose but not yet fully broken down, and at this point the organic carbon present in the bedrock seems to disappear entirely," notes Hemingway. At that point in the soil, the team also noticed an increase in lipids that are known to come from bacteria, he adds.

"We don't yet know exactly which bacteria are doing this -- that would require genomics, metagenomics, and other microbiological tools that we didn't use in this study. But that's the next step for this research," says WHOI marine geochemist Valier Galy, senior author and Hemingway's advisor in the MIT/WHOI Joint Program.

The group is quick to note that the total level of CO2 released by these microbes isn't severe enough to have any immediate impact on climate change -- instead, these processes take place on geologic timescales. The WHOI team's research may lead to a better understanding of how mountain-based (or "lithospheric") carbon cycles actually work, which could help generate clues to how CO2 has been regulated since the Earth itself formed.

Read more at Science Daily

Bad antibodies made good: The immune system's secret weapon uncovered

These new findings will fundamentally change thinking about how the immune system protects us.

The 'bad apples' of the immune system are also its secret weapon, according to major Australian research published today in the world-leading journal Science.

In a world first, scientists from Sydney's Garvan Institute of Medical Research have revealed how a population of 'bad' antibodies in the immune system -- which are usually 'silenced' because they can harm the body -- can provide crucial protection against invading microbes. The research was carried out in mice.

The 'bad' antibodies are known to react against the body's own tissues and can cause autoimmune disease. For this reason, it was once thought that they were discarded by the immune system or that they were made inactive in the long term. However, the new findings show for the first time that 'bad' antibodies go through a rapid 'redemption' process and are activated when the body is faced with a disease threat that other antibodies cannot tackle.

As a result, the 'redeemed' antibodies no longer threaten the body, but instead become powerful weapons to fight disease -- and particularly diseases that evade the immune system by disguising themselves to look like normal body tissue.

Professor Chris Goodnow, who co-led the new research with A/Prof Daniel Christ (both Immunology Division, Garvan), says the new findings will fundamentally change thinking about how the immune system protects us.

"We once thought that harmful antibodies were discarded by the body -- like a few bad apples in the barrel -- and no one had any idea that you could start with a 'bad' antibody and make it good.

"From these new findings, we now know that every antibody is precious when it comes to fighting invading microbes -- and this new understanding means that 'bad' antibodies are a valuable resource for the development of vaccines for HIV, and for other diseases that go undercover in the body."

This study was made possible by the generosity of The Bill and Patricia Ritchie Foundation, and through funding from the National Health and Medical Research Council (Australia).

Carrying out the immune system's toughest task

The new research appears to solve an enduring mystery that has puzzled scientists for decades: How does the immune system attack invading microbes that look almost identical to the body's own molecules, without mounting an attack on the body at the same time?

Campylobacter, HIV and others are particularly problematic targets for the immune system because they have evolved to appear almost identical to the body's own molecules; they are 'wolves in sheep's clothing'. This makes it difficult for the immune system to attack them, because it systematically avoids using antibodies that can attack 'self'.

To understand how the immune system recognises these 'wolves in sheep's clothing', scientists from the Garvan Institute zeroed in on a mysterious army of immune cells in the bloodstream.

'Bad' antibodies are hiding inside silenced B cells

The silenced cell army contains millions of immune cells known as B cells -- which produce antibodies to fight diseases. Unlike other B cells, though, the cells of this army pose a danger to the body. This is because they can make 'bad' antibodies, which can attack 'self' and cause autoimmune disease. For this reason, they are kept in a long-term silenced state (known as anergy).

Professor Chris Goodnow discovered the silenced cells 30 years ago -- and has been working to understand their function ever since.

"The big question about these cells has been why they are there at all, and in such large numbers," says Prof Goodnow. "Why does the body keep these cells, whose antibodies pose a genuine risk to health, instead of destroying them completely, as we once thought?"

The new findings appear to answer that question, showing that selected cells in the army can be reawakened to fight invaders -- but only once their 'bad' antibodies are made good.

"We've shown that these silenced cells do have a crucial purpose, says Deborah Burnett, a PhD student at Garvan whose work forms the basis of the study. "Far from 'clogging up' the immune system for no good reason, they're providing weapons -- bad apples made good -- to fight off invaders whose 'wolf in sheep's clothing tactics make it almost impossible for the other cells of the immune system to fight them."

Three tiny DNA changes turn bad into brilliant

Working with a sophisticated preclinical mouse model, which was developed at Garvan by Prof Rob Brink (Immunology Division) and his team, the researchers showed that the silenced cells can produce antibodies when they encounter an invader that appears highly similar to 'self'.

Crucially, before the cells attack, the antibodies they make are first redeemed through tiny alterations to their DNA sequence. This ensures the antibody that each cell makes no longer attacks 'self', but rapidly becomes a 5000 times more potent weapon against the invading foreigner.

Remarkably, in the model system tested, only three DNA changes were needed to transform antibodies from dangerous cells to effective weapons against disease: a first change to stop the antibody from binding to 'self', and a further two changes to increase their ability to specifically bind the invader.

At the atomic level, a dimple makes the difference

In experiments conducted at the Australian Synchrotron, the research team showed how the three DNA changes rearrange the tips of the antibody in defined ways, so that it becomes much better at recognising the foreign molecule and worse at recognising 'self'. In particular, the redeemed antibody fits neatly around a nanoscale 'dimple' that is present on the foreign molecule but is absent on self.

"This research has taken us on an exciting journey," says A/Prof Christ. "Not only have we uncovered a new kind of immunity, we've been able to confirm precisely how a bad antibody can be made good.

"Crucially, these redeemed antibodies are by no means a fall-back option. In fact, our findings show the opposite -- that antibodies made by tweaking 'bad' antibodies can be even better than those developed through established pathways."

Read more at Science Daily

New insight into how Giant's Causeway and Devils Postpile were formed

This is the Giant's Causeway.

A new study by geoscientists at the University of Liverpool has identified the temperature at which cooling magma cracks to form geometric columns such as those found at the Giant's Causeway in Northern Ireland and Devils Postpile in the USA.

Geometric columns occur in many types of volcanic rocks and form as the rock cools and contracts, resulting in a regular array of polygonal prisms or columns.

Columnar joints are amongst the most amazing geological features on Earth and in many areas, including the Giant's Causeway, they have inspired mythologies and legends.

One of the most enduring and intriguing questions facing geologists is the temperature at which cooling magma forms these columnar joints.

Liverpool geoscientists undertook a research study to find out how hot the rocks were when they cracked open to form these spectacular stepping stones.

In a paper published in Nature Communications, researchers and students at the University's School of Environmental Sciences designed a new type of experiment to show how as magma cools, it contracts and accumulates stress, until it cracks. The study was performed on basaltic columns from Eyjafjallajökull volcano, Iceland.

They designed a novel apparatus to permit cooling lava, gripped in a press, to contract and crack to form a column. These new experiments demonstrated that the rocks fracture when they cool about 90 to 140?C below the temperature at which magma crystallises into a rock, which is about 980?C for basalts.

This means that columnar joints exposed in basaltic rocks, as observed at the Giant's Causeway and Devils Postpile (USA) amongst others, were formed around 840-890 ?C.

Yan Lavallée, Liverpool Professor of Volcanology who headed the research, said: "The temperature at which magma cools to form these columnar joints is a question that has fascinated the world of geology for a very long time. We have been wanting to know whether the temperature of the lava that causes the fractures was hot, warm or cold.

"I have spent over a decade pondering how to address this question and construct the right experiment to find the answer to this question. Now, with this study, we have found that the answer is hot, but after it solidified."

Dr Anthony Lamur, for whom this work formed part of his doctoral study, added: "These experiments were technically very challenging, but they clearly demonstrate the power and significance of thermal contraction on the evolution of cooling rocks and the development of fractures."

Dr Jackie Kendrick, a post-doctoral researcher in the Liverpool group said: "Knowing the point at which cooling magma fractures is critical, as -beyond leading to the incision of this stunning geometrical feature- it initiates fluid circulation in the fracture network. Fluid flow controls heat transfer in volcanic systems, which can be harnessed for geothermal energy production. So the findings have tremendous applications for both volcanology and geothermal research."

Understanding how cooling magma and rocks contract and fracture is central to understand the stability of volcanic constructs as well as how heat is transferred in the Earth.

Professor Lavallée added: "The findings shed light on the enigmatic observations of coolant loss made by Icelandic engineers as they drilled into hot volcanic rocks in excess of 800?C; the loss of coolant in this environment was not anticipated, but our study suggests that substantial contraction of such hot rocks would have opened wide fractures that drained away the cooling slurry from the borehole.

Read more at Science Daily

Biodiversity: 3 new rainbow chameleon species discovered

A male of the new species Calumma uetzi flaunting its display colors.

The diversity of Madagascar is unique. More than 420 reptile species are already known from this enormous island off the east coast of Madagascar, yet rainforested mountains across the island continue to yield new surprises: On an expedition carried out by the Zoologische Staatssammlung Munich in a remote area of northern Madagascar, a team of researchers has discovered a spectacularly coloured rainbow chameleon, now dubbed Calumma uetzi. The gorgeous display colouration of the new species, which makes it easily distinguishable from all other species, is at its most magnificent when individuals of both sexes encounter one another. Then, the male tries to impress the female with a raucous display of yellow, violet, and red. Yet these flashy colours alone are no guarantee of success; an unreceptive female will turn on a male, mouth agape, darkening her own skin to the point of nearly black.

While the new rainbow chameleon is found only in the relatively remote forests of the north of Madagascar, a second new species was discovered in a dwindling forest fragment just beside one of the island's most heavily travelled roads. This totally isolated forest fragment, which covers an area of scarcely 15 hectares, is the only known forest in which Calumma juliae occurs. "We hope," says David Prötzel, a PhD student at LMU and lead author of the new study, "that this area can be protected as soon as possible. Recent imagery from Google Earth shows that, since our discovery of this chameleon just two years ago, a significant area of its tiny home has already been lost to deforestation." Despite repeated visits by the researchers to the forest where this species is at home, only females have yet been found. "It will be really interesting to see what the males look like, and at what time of the year they can be found," says Prötzel.

Only a single, male specimen of the third species described in the new study, Calumma lefona, is known. X-ray micro-CT scanning of the head of this specimen revealed a large hole in the roof of the skull, lying directly over the brain. A systematic search among the related chameleons revealed that a hole is present in this position in at least six other Calumma species. Curiously, the species with these holes all occur at elevations of more than 1000 m above sea level. The biological function of this skeletal anomaly is something of a mystery, but the researchers think it may help in thermoregulation.

"Based on everything we know about these species, they all have very small distribution ranges," says Dr. Frank Glaw, who heads the Herpetology Section of the Zoologische Staatssammlung München, "but many new protected areas are now being established in Madagascar, which will certainly be important for the future of Madagascar's unique diversity." (ZSM/LMU) Zoological Journal of the Linnean Society 2018

From Science Daily

What makes someone believe or reject science? Quality of recordings

Separating fact from fiction in the age of alternate facts is becoming increasingly difficult, and now a new study has helped reveal why. Research by Dr Eryn Newman of The Australian National University (ANU) has found that when people listen to recordings of a scientist presenting their work, the quality of audio had a significant impact on whether people believed what they were hearing, regardless of who the researcher was or what they were talking about.

Dr Newman, of the ANU Research School of Psychology, said the results showed when it comes to communicating science, style can triumph over substance.

"When people are assessing the credibility of information, most of the time people are making a judgement based on how something feels," Dr Newman said."Our results showed that when the sound quality was poor, the participants thought the researcher wasn't as intelligent, they didn't like them as much and found their research less important."

The study used experiments where people viewed video clips of scientists speaking at conferences. One group of participants heard the recordings in clear high-quality audio, while the other group heard the same recordings with poor-quality audio.

Participants were then asked to evaluate the researchers and their work. Those who listened to the poorer quality audio consistently evaluated the scientists as less intelligent and their research as less important.

In a second experiment, researchers upped the ante and conducted the same experiment using renowned scientists discussing their work on the well-known US Science Friday radio program. This time the recordings included audio of the scientists being introduced with their qualifications and institutional affiliations."It made no difference," she said."As soon as we reduced the audio quality, all of a sudden the scientists and their research lost credibility."

As with the first experiments, participants thought the research was worse, the scientists were less competent and they also reported finding their work less interesting.

Dr Newman said in a time when genuine science is struggling to be heard above fake news and alternate facts, researchers need to consider not only the content of their messages, but features of the delivery.

"Another recent study showed false information travels six times faster than real information on Twitter," she said."Our results show that it's not just about who you are and what you are saying, it's about how your work is presented."

A research paper for the study has been published in the journals Science Communication.

The study was co-authored by Professor Norbert Schwarz of the University of Southern California.

From Science Daily

Omega-3s from fish oil supplements no better than placebo for dry eye

Omega-3 fatty acid supplements taken orally proved no better than placebo at relieving symptoms or signs of dry eye, according to the findings of a well-controlled trial funded by the National Eye Institute (NEI), part of the National Institutes of Health. Dry eye disease occurs when the film that coats the eye no longer maintains a healthy ocular surface, which can lead to discomfort and visual impairment. The condition affects an estimated 14 percent of adults in the United States. The paper was published online April 13 in the New England Journal of Medicine.

Annual sales of fish- and animal-derived supplements amount to more than a $1-billion market in the United States, according to the Nutrition Business Journal. Many formulations are sold over-the-counter, while others require a prescription or are available for purchase from a health care provider.

"The trial provides the most reliable and generalizable evidence thus far on omega-3 supplementation for dry eye disease," said Maryann Redford, D.D.S., M.P.H., program officer for clinical research at NEI. Despite insufficient evidence establishing the effectiveness of omega-3s, clinicians and their patients have been inclined to try the supplements for a variety of conditions with inflammatory components, including dry eye. "This well-controlled investigation conducted by the independently-led Dry Eye Assessment and Management (DREAM) Research Group shows that omega-3 supplements are no better than placebo for typical patients who suffer from dry eye."

The 27-center trial enrolled 535 participants with at least a six-month history of moderate to severe dry eye. Among them, 349 people were randomly assigned to receive 3 grams daily of fish-derived omega-3 fatty acids in five capsules. Each daily dose contained 2000 mg eicosapentaenoic acid (EPA) and 1000 mg docosahexaenoic acid (DHA). This dose of omega-3 is the highest ever tested for treating dry eye disease. The 186 people randomly assigned to the placebo group received 5 grams daily of olive oil (about 1 teaspoon) in identical capsules. Study participants and the researchers did not know their group assignment.

Blood tests at 12 months confirmed that 85 percent of people in the omega-3 group were still compliant with the therapy. In the omega-3 group, mean EPA levels quadrupled versus no change in the placebo group. Mean levels of oleic acid, the constituent of olive oil, remained stable in both treatment groups.

Importantly, unlike in most industry-sponsored trials, all participants were free to continue taking their previous medications for dry eye, such as artificial tears and prescription anti-inflammatory eye drops.

"Omega-3s are generally used as an add-on therapy. The study results are in the context of this real-world experience of treating symptomatic dry eye patients who request additional treatment," said study chair for the trial, Penny A. Asbell, M.D., of the Department of Ophthalmology at the Icahn School of Medicine at Mount Sinai in New York City.

Patient-reported symptoms were measured as change from baseline in the Ocular Surface Disease Index, a 100-point scale for assessing dry eye symptoms, with higher values representing greater severity. After 12 months, mean symptoms scores for people in both groups had improved substantially, but there was no significant difference in the degree of symptom improvement between the groups. Symptom scores improved by a mean of 13.9 points in the omega-3 group and 12.5 points in the placebo group. A reduction of at least 10 points on the index is considered significant enough for a person to notice improvement. Overall, 61 percent of people in the omega-3 group and 54 percent of those in the control group achieved at least a 10-point improvement in their symptom score, but the difference between the groups was not statistically significant.

Likewise, there were no significant differences between the groups in terms of improvement in signs of dry eye. Signs of dry eye were evaluated by the clinician using standardized tests that measure the amount and quality of tears and the integrity of the cornea and the conjunctiva, the surface tissue that covers the front of the eye.

"The findings also emphasize the difficulty in judging whether a treatment really helps a particular dry eye patient," said the leader of the coordinating center for the study, Maureen G. Maguire, Ph.D., of the Department of Ophthalmology at the Perelman School of Medicine at the University of Pennsylvania, Philadelphia. "More than half the people taking placebo reported substantial symptom improvement during the year-long study."

Read more at Science Daily

Background hum of space could reveal hidden black holes

Drs Eric Thrane and Rory Smith.

Deep space is not as silent as we have been led to believe. Every few minutes a pair of black holes smash into each other. These cataclysms release ripples in the fabric of spacetime known as gravitational waves. Now Monash University scientists have developed a way to listen in on these events. The gravitational waves from black hole mergers imprint a distinctive whooping sound in the data collected by gravitational-wave detectors. The new technique is expected to reveal the presence of thousands of previously hidden black holes by teasing out their faint whoops from a sea of static.

Last year, in one of the biggest astronomical discoveries of the 21st century, LIGO Scientific Collaboration (LSC) and Virgo Collaboration researchers measured gravitational waves from a pair of merging neutron stars.

Drs Eric Thrane and Rory Smith, from the ARC Centre of Excellence for Gravitational Wave Discovery (OzGrav) and Monash University, were part of the team involved in last year's discovery and were also part of the team involved in the detection of first gravitational-wave discovery in 2015, when ripples in the fabric of space time generated by the collision of two black holes in the distant Universe were first witnessed, confirming Albert Einstein's 1915 general theory of relativity.

To date, there have been six confirmed, or gold plated, gravitational-wave events announced by the LIGO and Virgo Collaborations. However there are, according to Dr Thrane, more than 100,000 gravitational wave events every year too faint for LIGO and Virgo to unambiguously detect. The gravitational waves from these mergers combine to create a gravitational-wave background. While the individual events that contribute to it cannot be resolved individually, researchers have sought for years to detect this quiet gravitational-wave hum.

In a landmark paper in the journal, Physical Review X, the two researchers have developed a new, more sensitive way of searching for the gravitational-wave background.

"Measuring the gravitational-wave background will allow us to study populations of black holes at vast distances. Someday, the technique may enable us to see gravitational waves from the Big Bang, hidden behind gravitational waves from black holes and neutron stars," Dr Thrane said.

The researchers developed computer simulations of faint black hole signals, collecting masses of data until they were convinced that -- within the simulated data -- was faint, but unambiguous evidence of black hole mergers. Dr Smith is optimistic that the method will yield a detection when applied to real data. According to Dr Smith, recent improvements in data analysis will enable the detection of "what people had spent decades looking for." The new method is estimated to be one thousand times more sensitive, which should bring the long-sought goal within reach.

Importantly the researchers will have access to a new $4 million supercomputer, launched last month (March) at the Swinburne University of Technology. The computer, called OzSTAR, will be used by scientists to look for gravitational waves in LIGO data.

According to OzGRav Director, Professor Matthew Bailes, the supercomputer will allow OzGrav's researchers to attempt these kind of landmark discoveries.

"It is 125,000 times more powerful than the first supercomputer I built at the institution in 1998."

Read more at Science Daily

The dinosaur menu, as revealed by calcium

From left to right: teeth of a giant crocodile, Sarcosuchus imperator, a spinosaurid, a non-spinosaurid theropod (abelisaurid or carcharodontosaurid), a pterosaur, a hadrosaurid (a herbivorous dinosaur), a pycnodont (fish), and a small crocodylomorph. The scale bar represents 2 cm.

By studying calcium in fossil remains in deposits in Morocco and Niger, researchers have been able to reconstruct the food chains of the past, thus explaining how so many predators could coexist in the dinosaurs' time. This study, conducted by the Laboratoire de géologie de Lyon: Terre, planètes et environnement (CNRS/ENS de Lyon/Claude Bernard Lyon 1 University), in partnership with the Centre for Research on Palaeobiodiversity and Palaeoenvironments (CNRS/French National Museum of Natural History/Sorbonne University), is published on April 11, 2018 in the Proceedings of the Royal Society of London B.

A hundred million years ago, in North Africa, terrestrial ecosystems were dominated by large predators -- giant theropod dinosaurs, large crocodiles -- with comparatively few herbivores. How were so many carnivores able to coexist?

To understand this, French researchers have studied fossils in the Gadoufaoua deposits in Niger (dating from 120 million years ago) and the Kem Kem Beds in Morocco (dating from 100 million years ago). These two sites are characterized by an overabundance of predators compared to the herbivorous dinosaurs found in the locality. More specifically, the researchers measured the proportions of different calcium isotopes(1) in the fossilized remains (tooth enamel and fish scales).

Among vertebrates, calcium is almost exclusively derived from food. By comparing the isotopic composition of potential prey (fish, herbivores) with that of the carnivores' teeth, it is thus possible to retrace the diet of those carnivores.

The data obtained show similar food preferences at the two deposits: some large carnivorous dinosaurs (abelisaurids and carcharodontosaurids) preferred to hunt terrestrial prey such as herbivorous dinosaurs, while others (the spinosaurids) were piscivorous (fish-eating).(2) The giant crocodile-like Sarcosuchus had a diet somewhere in between, made up of both terrestrial and aquatic prey. Thus, the different predators avoided competition by subtly sharing food resources.

Read more at Science Daily

Scientists discover first super salty subglacial lakes in Canadian Arctic

More than half a kilometre beneath the Devon Ice Cap, scientists discovered two lakes whose extreme saltiness could make them a habitat for microbes--an environment that might also exist on Jupiter's icy moon Europa.

An analysis of radar data led scientists to an unexpected discovery of two lakes located beneath 550 to 750 metres of ice underneath the Devon Ice Cap, one of the largest ice caps in the Canadian Arctic. They are thought to be the first isolated hypersaline subglacial lakes in the world.

"We weren't looking for subglacial lakes. The ice is frozen to the ground underneath that part of the Devon Ice Cap, so we didn't expect to find liquid water," said Anja Rutishauser, PhD student at the University of Alberta, who made the discovery while studying airborne radar data acquired by NASA and The University of Texas Institute for Geophysics (UTIG) to describe the bedrock conditions underneath the Devon Ice Cap. Ice penetrating radar sounding measurements are based on electromagnetic waves that are sent through the ice and reflected back at contrasts in the subsurface materials, essentially allowing scientists to see through the ice.

"We saw these radar signatures telling us there's water, but we thought it was impossible that there could be liquid water underneath this ice, where it is below -10C."

While there are more than 400 known subglacial lakes in the world, concentrated primarily in Antarctica with a few in Greenland, these are the first found in the Canadian Arctic. And unlike all the others -- which are believed to contain freshwater -- these two appear to consist of hypersaline water. Rutishauser explained that the source of the salinity comes from salt-bearing geologic outcrops underneath the ice.

Rutishauser collaborated with her PhD supervisor, UAlberta glaciologist Martin Sharp and University of Texas geophysicist Don Blankenship as well as other scientists from University of Texas at Austin, Montana State University, Stanford University, and the Scott Polar Research Institute to test her hypothesis. The bodies of water -- roughly eight and five kilometres squared, respectively -- exist at temperatures below freezing and are not connected to any marine water sources or surface meltwater inputs, but rather are hypersaline, containing water four to five times saltier than seawater, which allows the water to remain liquid at these cold temperatures.

These newly discovered lakes are a potential habitat for microbial life and may assist scientists in the search for life beyond earth. Though all subglacial lakes are good analogues for life beyond Earth, the hypersaline nature of the Devon lakes makes them particularly tantalizing analogues for ice-covered moons in our solar system.

"We think they can serve as a good analogue for Europa, one of Jupiter's icy moons, which has similar conditions of salty liquid water underneath -- and maybe within -- an ice shell," said Rutishauser.

"If there is microbial life in these lakes, it has likely been under the ice for at least 120,000 years, so it likely evolved in isolation. If we can collect a sample of the water, we may determine whether microbial life exists, how it evolved, and how it continues to live in this cold environment with no connection to the atmosphere."

Rutishauser believes that similar salty rock outcrops occur underneath other Canadian Arctic ice caps. "Although the Devon hypersaline subglacial lakes are very unique discoveries, we may find networks of brine-rich subglacial water systems elsewhere in the Canadian Arctic."

Rutishauser and her colleagues are now partnering with The W. Garfield Weston Foundation to undertake a more detailed airborne geophysical survey over the Devon Ice Cap this spring to derive more information about the lakes and their geological and hydrological contexts. For three generations, The W. Garfield Weston Foundation has pursued its mission to enhance and enrich the lives of Canadians. With a focus on medical research, the environment, and education, the Foundation aims to catalyze inquiry and innovation to bring about long-term change. As the Foundation marks its 60th anniversary, it continues to collaborate with a broad range of Canadian charities to further world-class research, explore new ideas, and create tangible benefits for the communities in which it works.

Read more at Science Daily

How life generates new forms

Rendering of DNA.

When organisms change during the course of evolution, often what drives new forms is not genes themselves, but gene regulation -- what turns genes on and off. A new study identifies the kind of gene regulation most likely to generate evolutionary change.

Most modern organisms store genetic information in DNA and transcribe the information from DNA into RNA. Protein "transcription factors" that inhibit or enhance transcription of genes in the DNA are said to regulate gene expression.

In a March paper in PNAS, a team in Switzerland at ETH Zürich and the University of Zürich demonstrated that gene regulation by protein transcription factors more readily powers evolutionary change than another form of gene regulation that works at the RNA level.

"That really surprised us," said senior author Andreas Wagner, an external professor at the Santa Fe Institute and chairman of the Institute of Evolutionary Biology and Environmental Studies at the University of Zürich. "It's not self-evident. It's one of those things you just don't know before you look."

"New forms of regulation are crucial for a lot of new features of life," said Wagner. "What distinguishes the body plan of humans from that of sea urchins or fruit flies is new kinds of regulation -- turning the right genes on and off at the right time."

Previous work by the same team showed that transcription factors show high levels of two key evolutionary traits -- robustness and evolvability. A robust system functions relatively normally even when mutations occur. In contrast, an evolvable system is able to generate new forms or traits in response to new mutations.

Added lead author Joshua Payne (ETH Zurich, Swiss Institute of Bioinformatics): "We find that transcription factor binding sites are highly evolvable because mutations often create binding sites for other transcription factors. In this way, mutations to transcription factor binding sites can readily bring forth phenotypic variation."

The evolvability of transcriptional regulation may help explain why organisms switched from using RNA to store information some 4 billion years ago, to using DNA and proteins, Wagner said.

From Science Daily

Pluto's largest moon, Charon, gets its first official feature names

Map projection of Charon, the largest of Pluto's five moons, annotated with its first set of official feature names. With a diameter of about 1,215 km, the France-sized moon is one of largest known objects in the Kuiper Belt, the region of icy, rocky bodies beyond Neptune.

The International Astronomical Union (IAU), the internationally recognized authority for naming celestial bodies and their surface features, recently approved a dozen names proposed by NASA's New Horizons team, which led the first reconnaissance of Pluto and its moons in 2015 with the New Horizons spacecraft. The New Horizons team had been using many of the chosen names informally to describe the many valleys, crevices and craters discovered during the first close-up look at the surface Charon.

Charon is one of the larger bodies in the Kuiper Belt, and has a wealth of geological features, as well as a collection of craters similar to those seen on most moons. These features and some of Charon's craters have now been assigned official names by the IAU.

The New Horizons team was instrumental in moving the new names through approval, and included the leader of the New Horizons missions, Dr. Alan Stern, and science team members Mark Showalter -- the group's chairman and liaison to the IAU -- Ross Beyer, Will Grundy, William McKinnon, Jeff Moore, Cathy Olkin, Paul Schenk and Amanda Zangari. The team gathered most of their ideas during the Our Plutoonline public naming campaign in 2015.

The names approved by the IAU encompass the diverse range of recommendations the team received from around the world during the Our Pluto campaign. As well as the efforts of the New Horizons team, members of the public all over the world helped to name the features of Charon by contributing their suggestions for names of the features of this far-flung moon.

Honouring the epic exploration of Pluto that New Horizons accomplished, many of the feature names in the Pluto system pay homage to the spirit of human exploration, honouring travellers, explorers and scientists, pioneering journeys, and mysterious destinations. Rita Schulz, chair of the IAU Working Group for Planetary System Nomenclature, commented that "I am pleased that the features on Charon have been named with international spirit."

The approved Charon names focus on the literature and mythology of exploration. They are listed here:

Argo Chasma is named for the ship sailed by Jason and the Argonauts, in the epic Latin poem Argonautica, during their quest for the Golden Fleece.

Butler Mons honours Octavia E. Butler, the first science fiction writer to win a MacArthur fellowship, and whose Xenogenesis trilogy describes humankind's departure from Earth and subsequent return.

Caleuche Chasma is named for the mythological ghost ship that travels the seas around the small island of Chiloé, off the coast of Chile; according to legend, the Caleuche explores the coastline collecting the dead, who then live aboard it forever.

Clarke Montes honours Sir Arthur C. Clarke, the prolific science fiction writer and futurist whose novels and short stories (including 2001: A Space Odyssey) were imaginative depictions of space exploration.

Dorothy Crater recognizes the protagonist in the series of children's novels, by L. Frank Baum, that follows Dorothy Gale's travels to and adventures in the magical world of Oz.

Kubrick Mons honours film director Stanley Kubrick, whose iconic 2001: A Space Odyssey tells the story of humanity's evolution from tool-using hominids to space explorers and beyond.

Mandjet Chasma is named for one of the boats in Egyptian mythology that carried the sun god Ra (Re) across the sky each day -- making it one of the earliest mythological examples of a vessel of space travel.

Nasreddin Crater is named for the protagonist in thousands of humorous folktales told throughout the Middle East, southern Europe and parts of Asia.

Nemo Crater is named for the captain of the Nautilus, the submarine in Jules Verne's novels Twenty Thousand Leagues Under the Sea (1870) and The Mysterious Island (1874).

Pirx Crater is named for the main character in a series of short stories by Stanislaw Lem, who travels between the Earth, Moon and Mars.

Read more at Science Daily

To impress females, Costa's hummingbirds 'sing' with their tail feathers

Male Costa's hummingbirds, like the one shown here, court females using a high-speed dive in which they sing with their tail feathers.

In the world of Costa's hummingbirds, it's not size that matters -- it's sound. During breeding season, male Costa's perform a high-speed dive during which they "sing" to potential mates using their tail feathers.

Unlike related hummingbird species, Costa's perform their dives to the side of females, rather than in front of them. In a paper published today in Current Biology, researchers at the University of California, Riverside show this trajectory minimizes an audible Doppler sound that occurs when the Costa's dive. The Doppler effect is familiar to most people as the change in tone of an ambulance siren as the vehicle passes by.

The findings suggest that males can strategically manipulate the way females perceive their displays by minimizing the Doppler sound. This deprives females of an acoustic indicator that would otherwise reveal the speed of their dives.

"Recent studies in birds and other animals suggest that females prefer higher speeds during male athletic displays. By concealing their speed, males are not necessarily cheating, but instead have evolved this placement of trajectory out of female choice," said Christopher Clark, who led the study. Clark is an assistant professor of biology in UCR's College of Natural and Agricultural Sciences.

Clark and co-author Emily Mistick, a former research assistant at UCR, showed that males aim their sound toward potential mates by twisting their tail vertically by up to 90 degrees. In previous research, Clark has shown that the tail song is made by the flutter of the outer tail feathers.

"We don't know why males twist only half of their tails toward the females, but it may be due to anatomical limitations that prevent them from twisting their whole tail around," Clark said.

Clark and Mistick used a device called an acoustic camera to record Costa's dives. They also conducted experiments in a wind tunnel to examine how the birds' speed and direction influence the sounds they make. Curiously, they found it was difficult to measure the velocity of the Costa's dive from the sound produced.

"Once I realized it wasn't trivial for a scientist to measure, I realized it wouldn't be trivial for a female to measure either," Clark said.

Clark said the findings add to the literature about how male animals use athletic displays to attract females.

Read more at Science Daily

Tiny distortions in universe's oldest light reveal strands in cosmic web

In this illustration, the trajectory of cosmic microwave background (CMB) light is bent by structures known as filaments that are invisible to our eyes, creating an effect known as weak lensing captured by the Planck satellite (left), a space observatory. Researchers used computers to study this weak lensing of the CMB and produce a map of filaments, which typically span hundreds of light years in length.

Scientists have decoded faint distortions in the patterns of the universe's earliest light to map huge tubelike structures invisible to our eyes -- known as filaments -- that serve as superhighways for delivering matter to dense hubs such as galaxy clusters.

The international science team, which included researchers from the Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab) and UC Berkeley, analyzed data from past sky surveys using sophisticated image-recognition technology to home in on the gravity-based effects that identify the shapes of these filaments. They also used models and theories about the filaments to help guide and interpret their analysis.

Published April 9 in the journal Nature Astronomy, the detailed exploration of filaments will help researchers to better understand the formation and evolution of the cosmic web -- the large-scale structure of matter in the universe -- including the mysterious, unseen stuff known as dark matter that makes up about 85 percent of the total mass of the universe.

Dark matter constitutes the filaments -- which researchers learned typically stretch across hundreds of millions of light years -- and the so-called halos that host clusters of galaxies are fed by the universal network of filaments. More studies of these filaments could provide new insights about dark energy, another mystery of the universe that drives its accelerating expansion.

Filament properties could also put gravity theories to the test, including Einstein's theory of general relativity, and lend important clues to help solve an apparent mismatch in the amount of visible matter predicted to exist in the universe -- the "missing baryon problem."

"Usually researchers don't study these filaments directly -- they look at galaxies in observations," said Shirley Ho, a senior scientist at Berkeley Lab and Cooper-Siegel associate professor of physics at Carnegie Mellon University who led the study. "We used the same methods to find the filaments that Yahoo and Google use for image recognition, like recognizing the names of street signs or finding cats in photographs."

The study used data from the Baryon Oscillation Spectroscopic Survey, or BOSS, an Earth-based sky survey that captured light from about 1.5 million galaxies to study the universe's expansion and the patterned distribution of matter in the universe set in motion by the propagation of sound waves, or "baryonic acoustic oscillations," rippling in the early universe.

The BOSS survey team, which featured Berkeley Lab scientists in key roles, produced a catalog of likely filament structures that connected clusters of matter that researchers drew from in the latest study.

Researchers also relied on precise, space-based measurements of the cosmic microwave background, or CMB, which is the nearly uniform remnant signal from the first light of the universe. While this light signature is very similar across the universe, there are regular fluctuations that have been mapped in previous surveys.

In the latest study, researchers focused on patterned fluctuations in the CMB. They used sophisticated computer algorithms to seek out the imprint of filaments from gravity-based distortions in the CMB, known as weak lensing effects, that are caused by the CMB light passing through matter.

Since galaxies live in the densest regions of the universe, the weak lensing signal from the deflection of CMB light is strongest from those parts. Dark matter resides in the halos around those galaxies, and was also known to spread from those denser areas in filaments.

"We knew that these filaments should also cause a deflection of CMB and would also produce a measurable weak gravitational lensing signal," said Siyu He, the study's lead author who is a Ph.D. researcher from Carnegie Mellon University -- she is now at Berkeley Lab and is also affiliated with UC Berkeley. The research team used statistical techniques to identify and compare the "ridges," or points of higher density that theories informed them would point to the presence of filaments.

"We were not just trying to 'connect the dots' -- we were trying to find these ridges in the density, the local maximum points in density," she said. They checked their findings with other filament and galaxy cluster data, and with "mocks," or simulated filaments based on observations and theories. The team used large cosmological simulations generated at Berkeley Lab's National Energy Research Scientific Computing Center (NERSC), for example, to check for errors in their measurements.

The filaments and their connections can change shape and connections over time scales of hundreds of millions of years. The competing forces of the pull of gravity and the expansion of the universe can shorten or lengthen the filaments.

"Filaments are this integral part of the cosmic web, though it's unclear what is the relationship between the underlying dark matter and the filaments," and that was a primary motivation for the study, said Simone Ferraro, one of the study's authors who is a Miller postdoctoral fellow at UC Berkeley's Center for Cosmological Physics.

New data from existing experiments, and next-generation sky surveys such as the Berkeley Lab-led Dark Energy Spectroscopic Instrument (DESI) now under construction at Kitt Peak National Observatory in Arizona should provide even more detailed data about these filaments, he added.

Researchers noted that this important step in sleuthing the shapes and locations of filaments should also be useful for focused studies that seek to identify what types of gases inhabit the filaments, the temperatures of these gases, and the mechanisms for how particles enter and move around in the filaments. The study also allowed them to determine the length of filaments.

Siyu He said that resolving the filament structure can also provide clues to the properties and contents of the voids in space around the filaments, and "help with other theories that are modifications of general relativity," she said.

Read more at Science Daily

Fascinating zoo of discs discovered around young stars

New images from the SPHERE instrument on ESO's Very Large Telescope are revealing the dusty discs surrounding nearby young stars in greater detail than previously achieved. They show a bizarre variety of shapes, sizes and structures, including the likely effects of planets still in the process of forming.

The SPHERE instrument on ESO's Very Large Telescope (VLT) in Chile allows astronomers to suppress the brilliant light of nearby stars in order to obtain a better view of the regions surrounding them. This collection of new SPHERE images is just a sample of the wide variety of dusty discs being found around young stars.

These discs are wildly different in size and shape -- some contain bright rings, some dark rings, and some even resemble hamburgers. They also differ dramatically in appearance depending on their orientation in the sky -- from circular face-on discs to narrow discs seen almost edge-on.

SPHERE's primary task is to discover and study giant exoplanets orbiting nearby stars using direct imaging . But the instrument is also one of the best tools in existence to obtain images of the discs around young stars -- regions where planets may be forming. Studying such discs is critical to investigating the link between disc properties and the formation and presence of planets.

Many of the young stars shown here come from a new study of T Tauri stars, a class of stars that are very young (less than 10 million years old) and vary in brightness. The discs around these stars contain gas, dust, and planetesimals -- the building blocks of planets and the progenitors of planetary systems.

These images also show what our own Solar System may have looked like in the early stages of its formation, more than four billion years ago.

Most of the images presented were obtained as part of the DARTTS-S (Discs ARound T Tauri Stars with SPHERE) survey. The distances of the targets ranged from 230 to 550 light-years away from Earth. For comparison, the Milky Way is roughly 100,000 light-years across, so these stars are, relatively speaking, very close to Earth. But even at this distance, it is very challenging to obtain good images of the faint reflected light from discs, since they are outshone by the dazzling light of their parent stars.

Another new SPHERE observation is the discovery of an edge-on disc around the star GSC 07396-00759, found by the SHINE (SpHere INfrared survey for Exoplanets) survey. This red star is a member of a multiple star system also included in the DARTTS-S sample but, oddly, this new disc appears to be more evolved than the gas-rich disc around the T Tauri star in the same system, although they are the same age. This puzzling difference in the evolutionary timescales of discs around two stars of the same age is another reason why astronomers are keen to find out more about discs and their characteristics.

Astronomers have used SPHERE to obtain many other impressive images , as well as for other studies including the interaction of a planet with a disc , the orbital motions within a system, and the time evolution of a disc.

Read more at Science Daily

Man develops severe 'thunderclap' headaches after eating world's hottest chili pepper

Carolina Reaper or HP22B chili pepper is the world's hottest pepper.

Taking part in a hot chilli pepper eating contest might have some unexpected consequences, highlight doctors in the journal BMJ Case Reports.

Their warning comes after a young man ended up in emergency care with excruciatingly painful episodic headaches after eating a 'Carolina Reaper,' the world's hottest chilli pepper.

His symptoms started immediately after he had eaten the chilli, with dry heaves. But he then developed severe neck pain and crushingly painful headaches, each of which lasted just a few seconds, over the next several days.

His pain was so severe that he sought emergency care, and was tested for various neurological conditions, the results of which all came back negative.

But a CT (computed tomography) scan showed that several arteries in his brain had constricted, prompting doctors to diagnose him with thunderclap headache secondary to reversible cerebral vasoconstriction syndrome (RCVS).

RCVS is characterised by temporary artery narrowing often accompanied by thunderclap headache. It doesn't always have an obvious cause, but can occur as a reaction to certain prescription meds, or after taking illegal drugs.

This is the first case to be associated with eating chilli peppers, explain the authors, although they point out that eating cayenne pepper has been linked to sudden constriction of the coronary artery and heart attacks.

"Given the development of symptoms immediately after exposure to a known vasoactive substance, it is plausible that our patient had RCVS secondary to the Carolina Reaper, write the authors.

The man's symptoms cleared up by themselves. And a CT scan 5 weeks later showed that his affected arteries had returned to their normal width.

From Science Daily

Atlantic Ocean circulation at weakest point in more than 1,500 years

When it comes to regulating global climate, the circulation of the Atlantic Ocean plays a key role. The constantly moving system of deep-water circulation, sometimes referred to as the Global Ocean Conveyor Belt, sends warm, salty Gulf Stream water to the North Atlantic where it releases heat to the atmosphere and warms Western Europe. The cooler water then sinks to great depths and travels all the way to Antarctica and eventually circulates back up to the Gulf Stream.

New research led by University College London (UCL) and Woods Hole Oceanographic Institution (WHOI) provides evidence that a key cog in the global ocean circulation system hasn't been running at peak strength since the mid-1800s and is currently at its weakest point in the past 1,600 years. If the system continues to weaken, it could disrupt weather patterns from the United States and Europe to the African Sahel, and cause more rapid increase in sea level on the U.S. East Coast.

When it comes to regulating global climate, the circulation of the Atlantic Ocean plays a key role. The constantly moving system of deep-water circulation, sometimes referred to as the Global Ocean Conveyor Belt, sends warm, salty Gulf Stream water to the North Atlantic where it releases heat to the atmosphere and warms Western Europe. The cooler water then sinks to great depths and travels all the way to Antarctica and eventually circulates back up to the Gulf Stream.

"Our study provides the first comprehensive analysis of ocean-based sediment records, demonstrating that this weakening of the Atlantic's overturning began near the end of the Little Ice Age, a centuries-long cold period that lasted until about 1850," said Dr. Delia Oppo, a senior scientist with WHOI and co-author of the study which was published in the April 12th issue of Nature.

Lead author Dr. David Thornalley, a senior lecturer at University College London and WHOI adjunct, believes that as the North Atlantic began to warm near the end of the Little Ice Age, freshwater disrupted the system, called the Atlantic Meridional Overturning Circulation (AMOC). Arctic sea ice, and ice sheets and glaciers surrounding the Arctic began to melt, forming a huge natural tap of fresh water that gushed into the North Atlantic. This huge influx of freshwater diluted the surface seawater, making it lighter and less able to sink deep, slowing down the AMOC system.

To investigate the Atlantic circulation in the past, the scientists first examined the size of sediment grains deposited by the deep-sea currents; the larger the grains, the stronger the current. Then, they used a variety of methods to reconstruct near-surface ocean temperatures in regions where temperature is influenced by AMOC strength.

"Combined, these approaches suggest that the AMOC has weakened over the past 150 years by approximately 15 to 20 percent" says Thornalley.

According to study co-author Dr. Jon Robson, a senior research scientist from the University of Reading, the new findings hint at a gap in current global climate models. "North Atlantic circulation is much more variable than previously thought," he said, "and it's important to figure out why the models underestimate the AMOC decreases we've observed." It could be because the models don't have active ice sheets, or maybe there was more Arctic melting, and thus more freshwater entering the system, than currently estimated.

Another study in the same issue of Nature, led by Levke Ceasar and Stefan Rahmstorf from the Potsdam Institute for Climate Impact Research, looked at climate model data and past sea-surface temperatures to reveal that AMOC has been weakening more rapidly since 1950 in response to recent global warming. Together, the two new studies provide complementary evidence that the present-day AMOC is exceptionally weak, offering both a longer-term perspective as well as detailed insight into recent decadal changes.

"What is common to the two periods of AMOC weakening -- the end of the Little Ice Age and recent decades -- is that they were both times of warming and melting," said Thornalley. "Warming and melting are predicted to continue in the future due to continued carbon dioxide emissions."

Read more at Science Daily

Paralyzed patient feels sensation again

fMRI is used to highlight select implant sites in the somatosensory cortex. Electrodes implanted in this region were able to stimulate neurons that produced physical sensations, like a squeeze or tap, in the arm of a paralyzed man.

For the first time, scientists at Caltech have induced natural sensations in the arm of a paralyzed man by stimulating a certain region of the brain with a tiny array of electrodes. The patient has a high-level spinal cord lesion and, besides not being able to move his limbs, also cannot feel them. The work could one day allow paralyzed people using prosthetic limbs to feel physical feedback from sensors placed on these devices.

The research was done in the laboratory of Richard Andersen, James G. Boswell Professor of Neuroscience, T&C Chen Brain-Machine Interface Center Leadership Chair, and director of the T&C Chen Brain-Machine Interface Center. A paper describing the work appears in the April 10 issue of the journal eLife.

The somatosensory cortex is a strip of brain that governs bodily sensations, both proprioceptive sensations (sensations of movement or the body's position in space) and cutaneous sensations (those of pressure, vibration, touch, and the like). Previous to the new work, neural implants targeting similar brain areas predominantly produced sensations such as tingling or buzzing in the hand. The Andersen lab's implant is able to produce much more natural sensation via intracortical stimulation, akin to sensations experienced by the patient prior to his injury.

The patient had become paralyzed from the shoulders down three years ago after a spinal cord injury. Two arrays of tiny electrodes were surgically inserted into his somatosensory cortex. Using the arrays, the researchers stimulated neurons in the region with very small pulses of electricity. The participant reported feeling different natural sensations -- such as squeezing, tapping, a sense of upward motion, and several others -- that would vary in type, intensity, and location depending on the frequency, amplitude, and location of stimulation from the arrays. It is the first time such natural sensations have been induced by intracortical neural stimulation.

"It was quite interesting," the study participant says of the sensations. "It was a lot of pinching, squeezing, movements, things like that. Hopefully it helps somebody in the future."

Though different types of stimulation did indeed induce varying sensations, the neural codes governing specific physical sensations are still unclear. In future work, the researchers hope to determine the precise ways to place the electrodes and stimulate somatosensory brain areas in order to induce specific feelings and create a kind of dictionary of stimulations and their corresponding sensations.

The next major step, according to Andersen, is to integrate the technology with existing neural prosthetics. In 2015, Andersen's laboratory developed brain-machine interfaces (BMIs) to connect a prosthetic robotic arm to electrodes implanted in the region of the brain that governs intentions. In this way, a paralyzed man was able to utilize the prosthetic arm to reach out, grasp a cup, and bring it to his mouth to take a drink. Connecting the device with the somatosensory cortex would create bidirectional BMIs that would enable a paralyzed person to feel again, while using prosthetic limbs.

Read more at Science Daily

Vaccination apathy fueled by decades of misinformation

A legacy of social and political factors rather than bad parenting may be influencing people's decisions not to vaccinate their children, according to a study from the University of Waterloo.

The study, which appears in the Canadian Medical Association Journal, shows that a history of drug scandals, medical training practices, and a lack of political priority placed on disease prevention that started in the 1960s could be responsible for the immunization apathy, also known as vaccine hesitancy, we're seeing today.

"It's not all about the parents, said Heather MacDougall, history professor at Waterloo and co-author of the study. "History reveals systemic problems including lack of public education, lack of access, lack of training, and, perhaps most importantly, lack of political will for a national immunization schedule."

MacDougall and co-author Laurence Monnais of Université de Montréal, trace and analyze the contested adoption of the measles vaccine over three decades up to 1998, just before the infamous Andrew Wakefield publication that falsely linked the MMR vaccination to autism.

Their study shows that the vaccine hesitancy phenomenon started well before the 1990s and offers insight on the forces at play behind current instances of vaccine hesitancy.

The historians documented trends since the 1960s, such as the thalidomide disaster of 1962, and the emergence of new styles of parenting, second-wave feminism, and the popularization of alternative medicine.

Measles outbreaks in the 1970s and 1980s corresponded with a shift to individual rather than collective responsibility for personal health and health promotion, according to the study. By the 1990s, the national and international focus on children's rights and child health made young parents more willing to question whether their child would benefit from vaccination.

"Lack of sustained training in the rapidly changing science of immunology left Canadian health care practitioners with limited knowledge to provide guidance when asked to explain the benefits of vaccination to anxious parents," said MacDougall.

The division of federal, provincial, and territorial powers over healthcare have created a systemic disadvantage for the consensus needed to develop a consistent national immunization program.

"By publishing our research, the Canadian Medical Association Journal confirms the relevance of humanities disciplines such as history to help us understand social phenomena such as vaccine hesitancy in the face disease outbreaks," said MacDougall.

From Science Daily

Birds migrate away from diseases

Migrating geese.

In a unique study, researchers at Lund University in Sweden have mapped the origins of migratory birds. They used the results to investigate and discover major differences in the immune systems of sedentary and migratory birds. The researchers conclude that migratory species benefit from leaving tropical areas when it is time to raise their young -- as moving away from diseases in the tropics enables them to survive with a less costly immune system.

Analysing the genealogy of over 1300 song bird species, passerines, enabled the researchers to establish that both sedentary birds, which do not leave northern Europe in the winter, and migratory birds, which breed in Europe but spend the winter close to the equator, originate from Africa.

The researchers then went on to study the immune system in three different groups: sedentary birds in tropical Africa, European sedentary birds, and migratory birds. Their findings show that African sedentary birds have a more varied and extensive immune system than that of both European sedentary birds and migratory birds.

Evolution has quite simply ensured that bird species migrating to Europe were equipped with a much less variable immune system, as Europe has far fewer diseases than the tropics. The African sedentary species probably need a more advanced immune system to deal with the richer flora of pathogens to which they are exposed.

"What really surprises me is that the immune systems of migratory birds show a similarly low variation to that of European sedentary birds. After all, migratory birds don't only need to resist diseases in Europe, but also during their migration and in the tropics," says Helena Westerdahl, one of the researchers behind the study.

To explain the surprising result, the researchers propose the idea that the costs associated with a strong and complex immune system could be much higher than anyone previously thought. Examples of these costs could be autoimmunity and other immune system diseases such as chronic inflammation.

Despite the migratory birds having to deal with pathogens both in Europe and tropical Africa, they have thus lost much of the variation and complexity in their immune system compared to their African ancestors. According to the researchers, this indicates that dealing with pathogens is most difficult for the birds the first time they are exposed to them. For migratory birds, this happens in Europe where they raise their young and there are not as many different pathogens.

"When the migratory birds breed, they have moved away from many diseases and therefore do not need an immune system that is equally varied. Another advantage is that the risk of damage caused by the immune system drops considerably if the immune system is less complex," says researcher Emily O'Connor.

Read more at Science Daily

Melting of Arctic mountain glaciers unprecedented in the past 400 years

Scientists spent a month in Denali National Park in 2013 drilling ice cores from the summit plateau of Mt. Hunter. The ice cores showed the glaciers on Mt. Hunter are melting more now than at any time in the past 400 years.

Glaciers in Alaska's Denali National Park are melting faster than at any time in the past four centuries because of rising summer temperatures, a new study finds.

New ice cores taken from the summit of Mt. Hunter in Denali National Park show summers there are least 1.2-2 degrees Celsius (2.2-3.6 degrees Fahrenheit) warmer than summers were during the 18th, 19th, and early 20th centuries. The warming at Mt. Hunter is about double the amount of warming that has occurred during the summer at areas at sea level in Alaska over the same time period, according to the new research.

The warmer temperatures are melting 60 times more snow from Mt. Hunter today than the amount of snow that melted during the summer before the start of the industrial period 150 years ago, according to the study. More snow now melts on Mt. Hunter than at any time in the past 400 years, said Dominic Winski, a glaciologist at Dartmouth College in Hanover, New Hampshire and lead author of the new study published in the Journal of Geophysical Research: Atmospheres, a journal of the American Geophysical Union.

The new study's results show the Alaska Range has been warming rapidly for at least a century. The Alaska Range is an arc of mountains in southern Alaska home to Denali, North America's highest peak.

The warming correlates with hotter temperatures in the tropical Pacific Ocean, according to the study's authors. Previous research has shown the tropical Pacific has warmed over the past century due to increased greenhouse gas emissions.

The study's authors conclude warming of the tropical Pacific Ocean has contributed to the unprecedented melting of Mt. Hunter's glaciers by altering how air moves from the tropics to the poles. They suspect melting of mountain glaciers may accelerate faster than melting of sea level glaciers as the Arctic continues to warm.

Understanding how mountain glaciers are responding to climate change is important because they provide fresh water to many heavily-populated areas of the globe and can contribute to sea level rise, Winski said.

"The natural climate system has changed since the onset of the anthropogenic era," he said. "In the North Pacific, this means temperature and precipitation patterns are different today than they were during the preindustrial period."

Assembling a long-term temperature record

Winski and 11 other researchers from Dartmouth College, the University of Maine and the University of New Hampshire drilled ice cores from Mt. Hunter in June 2013. They wanted to better understand how the climate of the Alaska Range has changed over the past several hundred years, because few weather station records of past climate in mountainous areas go back further than 1950.

The research team drilled two ice cores from a glacier on Mt. Hunter's summit plateau, 13,000 feet above sea level. The ice cores captured climate conditions on the mountain going back to the mid-17th century.

The physical properties of the ice showed the researchers what the mountain's past climate was like. Bands of darker ice with no bubbles indicated times when snow on the glacier had melted in past summers before re-freezing.

Winski and his team counted all the dark bands -- the melt layers -- from each ice core and used each melt layer's position in the core to determine when each melt event occurred. The more melt events they observed in a given year, the warmer the summer.

They found melt events occur 57 times more frequently today than they did 150 years ago. In fact, they counted only four years with melt events prior to 1850. They also found the total amount of annual meltwater in the cores has increased 60-fold over the past 150 years.

The surge in melt events corresponds to a summer temperature increase of at least 1.2-2 degrees Celsius (2.2-3.6 degrees Fahrenheit) relative to the warmest periods of the 18th and 19th centuries, with nearly all of the increase occurring in the last 100 years. Because there were so few melt events before the start of the 20th century, the temperature change over the past few centuries could be even higher, Winski said.

Connecting the Arctic to the tropics

The research team compared the temperature changes at Mt. Hunter with those from lower elevations in Alaska and in the Pacific Ocean. Glaciers on Mt. Hunter are easily influenced by temperature variations in the tropical Pacific Ocean because there are no large mountains to the south to block incoming winds from the coast, according to the researchers.

They found during years with more melt events on Mt. Hunter, tropical Pacific temperatures were higher. The researchers suspect warmer temperatures in the tropical Pacific Ocean amplify warming at high elevations in the Arctic by changing air circulation patterns. Warmer tropics lead to higher atmospheric pressures and more sunny days over the Alaska Range, which contribute to more glacial melting in the summer, Winski said.

Read more at Science Daily

Outback radio telescope listens in on interstellar visitor

This artist's impression shows the first interstellar asteroid: `Oumuamua.

A telescope in outback Western Australia has been used to listen to a mysterious cigar-shaped object that entered our Solar System late last year.

The unusual object -- known as 'Oumuamua -- came from another solar system, prompting speculation it could be an alien spacecraft.

So astronomers went back through observations from the Murchison Widefield Array (MWA) telescope to check for radio transmissions coming from the object between the frequencies of 72 and 102MHz -- similar to the frequency range in which FM radio is broadcast.

While they did not find any signs of intelligent life, the research helped expand the search for extra-terrestrial intelligence (SETI) from distant stars to objects closer to home.

When 'Oumuamua was first discovered, astronomers thought it was a comet or an asteroid from within the Solar System. But after studying its orbit and discovering its long, cylindrical shape, they realised 'Oumuamua was neither and had come from interstellar space.

Telescopes around the world trained their gaze on the mysterious visitor in an effort to learn as much as possible before it headed back out of the Solar System, becoming too faint to observe in detail.

John Curtin Distinguished Professor Steven Tingay, from the Curtin University node of the International Centre for Radio Astronomy Research (ICRAR), said the MWA team did not initially set out to find 'Oumuamua.

"We didn't set out to observe this object with the MWA but because we can see such a large fraction of the sky at once, when something like this happens, we're able to go back through the data and analyse it after the fact," Professor Tingay said.

"If advanced civilizations do exist elsewhere in our galaxy, we can speculate that they might develop the capability to launch spacecraft over interstellar distances and that these spacecraft may use radio waves to communicate."

"Whilst the possibility of this is extremely low, possibly even zero, as scientists it's important that we avoid complacency and examine observations and evidence without bias."

The MWA is located in Western Australia's remote Murchison region, one of the most radio-quiet areas on the planet and far from human activity and radio interference caused by technology.

It is made up of thousands of antennas attached to hundreds of "tiles" that dot the ancient landscape, relentlessly observing the heavens day after day, night after night.

Professor Tingay said the research team was able to look back through all of the MWA's observations from November, December and early January, when 'Oumuamua was between 95 million and 590 million kilometres from Earth.

"We found nothing, but as the first object of its class to be discovered, `Oumuamua has given us an interesting opportunity to expand the search for extra-terrestrial intelligence from traditional targets such as stars and galaxies to objects that are much closer to Earth.

"This also allows for searches for transmitters that are many orders of magnitude less powerful than those that would be detectable from a planet orbiting even the most nearby stars."

'Oumuamua was first discovered by the Pan-STARRS project at the University of Hawaii in October.

Its name loosely means "a messenger that reaches out from the distant past" in Hawaiian, and is the first known interstellar object to pass through our Solar System.

Combining observations from a host of telescopes, scientists have determined that `Oumuamua is most likely a cometary fragment that has lost much of its surface water because it was bombarded by cosmic rays on its long journey through interstellar space.

Researchers have now suggested there could be more than 46 million similar interstellar objects crossing the Solar System every year.

Read more at Science Daily

Water appeared while Earth was still growing

Meteorites such as these carbonaceous chondrites are thought to have delivered water to the Earth--but an outstanding question is when. A new study points to the early incorporation of water in the growing Earth.

Up until about ten years ago, scientists thought they had a pretty good picture of how the moon and Earth came to co-exist. Then more precise measurements blew it all wide open, and scientists are still struggling to reconcile them.

As part of that effort, a team including UChicago cosmochemist Nicolas Dauphas performed the largest study to date of oxygen isotopes in lunar rocks, and found a small but measurable difference in the makeup of the moon and Earth.

Published March 28 in Science Advances, the research proposes that Earth acquired the majority of its water during the main stage of its growth -- which counters a popular theory.

The most widely accepted theory of the origin of the Moon speculates that a giant object smashed into the proto-Earth at just enough velocity that part of both bodies broke off and formed the moon. The Earth has a little of the moon and the moon has more of the Earth, but they'd be mostly different objects. Early measurements -- many taken by the late UChicago geochemist Robert Clayton -- did not have sufficient precision to tell the Moon and Earth apart.

But in the last decade, Dauphas said, it became clear this picture wasn't quite right. Elements can come in different forms, called isotopes, and these give scientists clues to the rock's origin. As ways to measure isotopes improved, scientists discovered striking similarities between the moon and the Earth. Referred to as the "lunar isotopic crisis," this was a problem for the main theory of lunar formation, because it's highly unlikely the isotopes would be exactly the same for two random objects in the solar system.

"This, to my mind, is one of the most compelling questions in modern planetary science," said Dauphas, head of the Origins Laboratory and professor in the Department of Geophysical Sciences and the Enrico Fermi Institute. "Right now it's completely open. It's amazing to still be asking this."

One theory to explain the matching isotopes was a scenario in which the proto-Earth was totally vaporized by one or more giant impacts, and both it and the moon formed out of the cloud. But one of the major uncertainties is that scientists have reached different conclusions about how different the oxygen isotopes are between lunar and terrestrial rocks.

Seeking to clarify the issue, the researchers measured the oxygen isotopes of both lunar and terrestrial rocks with extremely high precision. They found a very small, but detectable difference between the isotopes between the two bodies.

To explain the near match, the authors turn to water. A popular theory is that the Earth got the majority of its water after the great impact, as more objects containing ice hit the Earth as meteorites. (The term to describe it is late veneer, meaning that water is delivered to the Earth as a veneer after the Earth has completed its growth.)

But if most of Earth's water was delivered via later meteorites, this would have shown up as a greater isotopic difference than what the researchers measured -- as water-bearing meteorites have unusual mixtures of oxygen isotopes.

Their model suggests that only 5 percent to 30 percent of all the water on Earth would have arrived on meteorites after the great impact.

Dauphas noted the picture is still evolving because depending on which element you measure, differences between the moon and Earth could be found. "Oxygen, titanium, tungsten -- these are the ones that are still keeping us up at night," he said.

The question of how planets acquire water is interesting for a number of reasons, Dauphas said, including the search for distant exoplanets that might have water -- and thus a similar kind of life.

Read more at Science Daily

Giant ichthyosaur is one of largest animals ever

Jaw bone of giant ichthyosaur.

The 205 million-year-old jaw bone of a prehistoric reptile belongs to 'one of the largest animals ever' say a group of international palaeontologists.

The new discovery has also solved a 150 year old mystery of supposed 'dinosaur bones' from the UK.

The bone belongs to a giant ichthyosaur, a type of prehistoric aquatic reptile, and experts estimate the length of this specimen's body would have been up to 26 metres. Approaching the size of a blue whale.

Fossil collector and co-author of the study, Paul de la Salle, found the bone on the beach at Lilstock, Somerset in May 2016. He later returned to the site and found even more pieces that together measured about one metre in length.

Paul said "Initially, the bone just looked like a piece of rock but, after recognising a groove and bone structure, I thought it might be part of a jaw from an ichthyosaur and immediately contacted ichthyosaur experts Dean Lomax (University of Manchester) and Prof. Judy Massare (SUNY College at Brockport, NY, USA) who expressed interest in studying the specimen. I also contacted Dr Ramues Gallois, a geologist who visited the site and determined the age of the specimen stratigraphically.

Lomax and Massare identified the specimen as an incomplete bone (called a surangular) from the lower jaw of a giant ichthyosaur. The bone would have made up only a portion of the entire skull. They compared it with several ichthyosaurs and visited the Royal Tyrrell Museum of Palaeontology in Alberta, Canada, and examined the largest ichthyosaur known, the shastasaurid Shonisaurus sikanniensis, which is 21 m long. They found similarities between the new specimen and S. sikanniensis which suggest the Lilstock specimen belongs to a giant shastasaurid-like ichthyosaur.

"As the specimen is represented only by a large piece of jaw, it is difficult to provide a size estimate, but by using a simple scaling factor and comparing the same bone in S. sikanniensis, the Lilstock specimen is about 25% larger. Other comparisons suggest the Lilstock ichthyosaur was at least 20-25 m. Of course, such estimates are not entirely realistic because of differences between species. Nonetheless, simple scaling is commonly used to estimate size, especially when comparative material is scarce." Added Lomax.

In 1850, a large bone was described from the Late Triassic (208 million-years-old) of Aust Cliff, Gloucestershire, UK. Four other similarly incomplete bones were also found and described. Two of them are now missing and presumed destroyed. They have been identified as the limb bones of several dinosaurs (stegosaurs and sauropods), indeterminate dinosaurs and other reptiles.

However, with the discovery of the Lilstock specimen, this new study refutes previous identifications and also the most recent assertion that the Aust bones represent an early experiment of dinosaur-like gigantism in terrestrial reptiles. They are, in fact, jaw fragments of giant, previously unrecognised ichthyosaurs.

Read more at Science Daily