Living under pressure: Lessons from the cradle of life

by John Hewitt , Phys.org 

Credit: JPL/NASA

Deep sea alkaline hydrothermal vents have been theorized to be a place where life could have originated. The elevated temperature, alkaline pH, and unique vent action concentrate minerals and create local energetic gradients that can promote primitive metabolic reactions. Although sometimes overlooked, the extreme hydrostatic pressures found in deep sea vents can also facilitate various kinds of molecular assembly that would not otherwise spontaneously occur at sea level.

Today, there are many complex organisms that have persisted, or otherwise re-inhabited, the deep sea through various metabolic and physiologic adaptations. Among the most extreme are the 'piezophilic' or pressure-loving prokaryotes of the Colwellia family. These organisms can be found in the deepest trenches some 11,000 meters below the surface, where pressures reach 110 megapascals (atmospheric pressure is 0.1 MPa). A recent paper published in BioRxiv analyzes the genomes of seven strains of Colwellia to find out exactly how life adapts to high pressure.

What they found was that the more piezophilic strains of Colwellia had much higher levels of basic and hydrophobic amino acids in their proteome. This would likely stabilize and limit water intrusion into proteins under pressure. The piezophilic group also had more genes for replication, recombination and repair proteins, and also for cell motility and biogenesis of the cell wall and membrane. More specifically, they had a higher percentage of unsaturated fatty acids and variant forms of cholesterol that are crucial for adjusting and maintaining membrane fluidity under high pressure.

Interestingly, many of these genes were found exclusively within highly variable regions known as genomic islands, indicating that these adaptations were likely facilitated by horizontal gene transfer through transposases or other mobile elements. One peculiarity found in these variable regions is an abundance of the rapidly modified toxin-antitoxin gene systems that are also found in many bacteria. Another observation was that the piezophilic group lacked TMAO reductase, the enzyme that reduces TMAO to TMA. This has been attributed to a preferential need for TMAO as a 'piezolyte' over its alternative use as an electron acceptor.

In looking closer at energetics and respiration, the authors identified an additional NADH ubiquinone oxidoreductase 'nuo' gene cluster in piezophiles. This unique NADH dehydrogenase translocates four protons per two electrons, and may help with energy acquisition under high pressure. Curiously, it is noted that the shewanella bacterium—now famous for its eclectic spin-dependent electron transport through multiheme electron circuits—has many similarities to Colwellia. These include not just the same kind of NADH oxidoreductases mentioned above, but also similar hypervariable toxin-antitoxin genetic systems.

High pressure can exert its effects across many different scales in living things. In general, it will alter intermolecular distances and conformations, but does not affect covalent bond lengths or bond angles. Peptides, lipids, and sugar macromolecular structures are only significantly perturbed above 2 GPa. On the other hand, protein association with DNA is less stable at elevated pressure, and the DNA double helix itself is shifted to denser forms, affecting transcription and expression.

While much of the deep sea is extremely cold, temperatures within hydrothermal vent regions can reach 400 degrees C. When combined with pressure above 30 MPa, conditions that correspond to the thermodynamic supercritical state are created. Supercritical water has an increased dielectric constant, viscosity, density and ionic hydration. As a result, the solubility of polar and ionic compounds decreases, while that of apolar molecules is enhanced. The net result of this is that prebiotic molecules are readily concentrated and can react more efficiently.

Once primitive metal-catalyzed metabolic reactions have taken hold, and amino acids are able to be polymerized into rudimentary proteins, we begin to grasp the evolution of the basic protein folds at the root of an ancient metabolic network. Such is the case for the ferredoxin fold that binds iron-sulfur compounds, and the "Rossmann" fold, which binds nucleotides. There is now evidence the two folds may have shared a common ancestor, and potentially could have been the first metabolic enzyme of life as we know it.

So why do we care about high pressure, and more importantly, what is a better understanding of it going to do for us now? For one, hyperbaric therapy has been hyped as a potential solution for many things. In fact, all the most luxurious superyachts have one below deck to decompress after a deep dive. That said, it has also been suggested as a way to bust up amyloid fibrils in Alzheimer's disease. But would that really be wise?

One potential problem is that the perplexing effect of high pressure on protein aggregation consists of, on the one hand, inducing aggregation-prone intermediate states, and on the other hand, the ability of high pressure to prevent aggregation and to dissociate aggregates. The susceptibility of protein aggregates to pressure largely depends on the degree of the structural order of an aggregate. Fresh, amorphous aggregates are more sensitive to pressure and prone to refolding to the native state than mature amyloid fibrils. Beyond Alzheimer's, these considerations may complicate other noble efforts now under review to zap infectious prion aggregates with high pressure.

Another intriguing use arises in the potential to decontaminate foods by pretreatment with high pressures. Perhaps even more timely would be the ultimate divine ability to selectively target various infectious influenza-like viruses using high pressure.Scientists have discovered the origins of the building blocks of life

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More information: Logan M. Peoples et al. Distinctive Gene and Protein Characteristics of Extremely Piezophilic Colwellia, (2020). DOI: 10.1101/2020.03.15.992594

© 2020 Science X Network

Autism rates declining among wealthy whites, escalating among poor

by Lisa Marshall, University of Colorado at Boulder

Credit: CC0 Public Domain

Wealthy, white California counties—once considered the nation's hotbeds for autism spectrum disorder (ASD) - have seen prevalence flatten or fall in the last two decades, while rates among poor whites and minorities keep ticking up, new CU Boulder research has found.

The study, published Thursday in the Journal of Autism and Developmental Disorders, raises the possibility that parents in wealthier counties are successfully reducing environmental exposures that may contribute to autism risk, or taking other steps to curb its severity early on.

While that's a hopeful possibility, the authors say, the findings also illuminate a disturbing economic and racial divide.

"While autism was once considered a condition that occurs mainly among whites of high socioeconomic status, these data suggest that the brunt of severe autism is now increasingly being borne by low-income families and ethnic minorities," said lead author Cynthia Nevison, Ph.D., an atmospheric research scientist with the Institute of Arctic and Alpine Research, who also studies environmental health.

Adds co-author Willam Parker, Ph.D., an autism researcher at Duke University Medical Center:

"There is potentially good news here, but, unfortunately, not everyone is a beneficiary of this good news."

A shift in Silicon Valley

For the study, the researchers analyzed 20 years' worth of autism caseload counts from the California Department of Developmental Services, comparing data from 36 of the state's most populous counties.

Between birth years 1993 and 2000, autism prevalence increased steadily among all racial groups.

But around 2000, the trajectories started to diverge: Prevalence among whites in wealthy counties like Santa Clara (home to Silicon Valley) and from Monterey to the San Francisco coast started to decline.

In middle -income counties like Sacramento, Los Angeles and San Diego, prevalence among whites continued to increase, but at a slower rate.

Meanwhile, in lower income areas like Riverside and the South Central Valley, rates among whites climbed steeply.

By birth year 2013, prevalence among whites in the lowest income counties was at least double that of whites in the highest income counties. Generally speaking, the higher the county income, the lower the rate of autism among white children.

Notably, Santa Clara County had a surge in the rate of autism spectrum disorders between 1993 and 2000, with rates doubling among whites and Asians in just seven years. As Nevison and Parker recall in the new paper, that surge gave rise to controversial theories—widely reported in the media—that men with poor social skills but strong math and engineering skills were increasingly able to find partners in the tech-age and were fathering "genetically autistic" children.

"Our data contradict that argument," said Nevison, noting that today Santa Clara County has one of the lowest prevalence rates of severe autism in the state among whites. Growth in prevalence among Asians has also flattened in the county.

Meanwhile, the study found, incidence among blacks has increased rapidly across California, marking the highest rates among any ethnic or racial group at 1.8%. That finding is in line with previous research finding that autism prevalence is rising rapidly nationwide among African Americans.

Seeking answers about lowering risk

Some health experts have attributed increases in prevalence among minorities to better screening and diagnosis, but the authors believe environmental factors also play a role.

Just which factors may be at play is unclear, but Parker notes that many of the same things that fuel disease-causing inflammation—toxins, unhealthy food and emotional stress—are also associated with autism. And lower income and minority families tend to have a harder time accessing or affording healthier lifestyle options.

Established risk factors associated with autism include: advanced parental age, challenges to the immune system during pregnancy, genetic mutations, premature birth and being a twin or multiple.

The authors cannot say if their findings would translate to other counties around the country or to milder forms of autism. They also cannot rule out the possibility that wealthy families are opting out of state services in favor of private services. More research is underway.

With autism affecting one in 59 children nationwide in 2018—a rate expected to be revised by the Centers for Disease Control later this spring –they hope the paper will encourage parents and policymakers to look beyond genetics and better outreach and diagnosis.

"There is an urgent need to understand what wealthy California parents are doing or have access to that may be lowering their children's risk," they conclude.

Autism rates increasing fastest among black, Hispanic youth

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More information: Cynthia Nevison et al. California Autism Prevalence by County and Race/Ethnicity: Declining Trends Among Wealthy Whites, Journal of Autism and Developmental Disorders (2020). DOI: 10.1007/s10803-020-04460-0

Journal information: Journal of Autism and Developmental Disorders

Private, online and hi-tech: the coronavirus economy

by India Bourke MARCH 22, 2020

Online retailers are experiencing a surge in orders from self-isolating consumers

The coronavirus pandemic has sent stock markets into freefall and industries to the wall, however many firms enabling more private, online and tech-based living are emerging as potential winners.


As hundreds of millions of people worldwide are forced to stay in their homes and not travel abroad, the businesses that are helping them to adapt could lead to long-term changes in the economy.

"I think certain aspects of work and organising will change for good through the current situation," said Sally Maitlis, a professor of organisational behaviour at Oxford University's Said Business School.

"People will discover that they can work and communicate in ways they previously didn't think possible, and will be forced to become more nimble with tech through having no choice to do otherwise."

Here are comparisons of several sectors that are thriving and failing in the pandemic:

E-commerce giants vs independent stores

Large online retailers have seen a surge in orders as self-isolating or home-working consumers turn to their massive distribution and delivery networks to provide daily essentials.

Shares in US retail giants Walmart and Amazon both tumbled as markets crashed around the world on March 16.

During the week Walmart rose as much as 25 percent from its nine-month low on Monday. Amazon also recovered.

Online retailers are experiencing a surge in orders as consumers turn to them during the coronavirus outbreak

"We are seeing increased online shopping and as a result some products such as household staples and medical supplies are out of stock," Amazon said.

Yet small, independent stores are suffering, said UK Federation of Small Businesses chair Mike Cherry.

"These are already very difficult times for all small businesses right across the country. There are huge concerns over supply chains while on top of this footfall continues to drop. The prospect for these businesses over the coming weeks is increasingly bleak."

Streaming vs cinemas

Demand for movies to watch at home has soared so much that Netflix and YouTube are reducing the quality of their streaming in Europe—which has become the epicentre of the virus—to ease pressure on the internet.


Worldwide streaming activity jumped by 20 percent last weekend, according to Bloomberg News.

Traditional cinema chains, however, are facing an unprecedented drop in demand.

India on March 12 reported its first coronavirus death as authorities ordered schools, theatres and cinemas closed in New Delhi for the rest of the month

Some have temporarily closed their doors to help contain the virus's spread.

US-listed shares in Cinemark and AMC Entertainment were both down around 60 percent on Friday from their respective highs in January and February.

Private jets vs commercial planes

The airline sector has been hit hard by quarantine rules and border closures, with UK airline Flybe crashing into bankruptcy and experts predicting others will follow.

The International Air Transport Association said Thursday that up to $200 billion is needed to rescue the global industry.

US airlines have sought more than $50 billion in government assistance in recent days, with one top US official saying the outbreak poses a bigger threat to the commercial industry than the September 11 attacks.

In contrast, private jet charter companies are seeing demand soar.

The global travel industry is one of the sectors hit hardest by the efforts to limit the novel coronavirus's spread

Wealthy customers are seeking to distance themselves from the "unknown" travel histories of fellow passengers, said Daniel Tang, from Hong Kong-based charter company MayJets.

US-based Paramount Business Jets has seen inquiries go "through the roof", its chief executive Richard Zaher said.

Queries have risen 400 percent and bookings are up 20-25 per cent.

Home workouts vs gyms

As many gyms close their doors, fitness-lovers are turning to online classes and home workouts.

Shares in US home gym equipment company Peloton surged as investors bet on increasing demand for its stationary exercise bikes and memberships to streaming online workout sessions.

At one stage Peloton's share price was up more than 50 percent from Monday's intra-day low.

Teleconferences vs real world meetings

With more and more people working from home to limit the virus's spread, demand for technology that enables online group meetings, chats and collaborations has spiked.

Graphic naming selected companies that could benefit from the "coronavirus economy,' according to a Forbes data from March 7

"There is such excitement around remote work that brands like Zoom have seen their stock value climb up," Creative Strategies analyst Carolina Milanesi said, referring to the teleconferencing app.

At the same time, real world gatherings from sporting events to business conferences, have been postponed or cancelled, with a large question mark still lingering over the fate of this summer's Olympic Games in Japan.

Crowdsourced virtual supercomputer revs up virus research
by Rob Lever

A crowdsourcing project drawing on individual and corporate computing power worldwide has created a supercomputer to help accelerate coronavirus research

Gamers, bitcoin "miners" and companies large and small have teamed up for an unprecedented data-crunching effort that aims to harness idle computing power to accelerate research for a coronavirus treatment.


The project led by computational biologists has effectively created the world's most powerful supercomputer that can handle trillions of calculations needed to understand the structure of the virus.

More than 400,000 users downloaded the application in the past two weeks from "Folding@Home," according to director Greg Bowman, a professor of biochemistry and molecular biophysics at Washington University in St. Louis, where the project is based.

The "distributed computing" effort ties together thousands of devices to create a virtual supercomputer.

The project originally launched at Stanford University 20 years ago was designed to use crowdsourced computing power for simulations to better understand diseases, especially "protein folding" anomalies that can make pathogens deadly.

"The simulations allow us to watch how every atom moves throughout time," Bowman told AFP.

The massive analysis looks for "pockets" or holes in the virus where a drug can be squeezed in.

"Our primary objective is to hunt for binding sites for therapeutics," Bowman said.

A crowdsourced computing project aims to find pockets or "holes" in the coronavirus which can be attacked with drugs

'Druggable targets'

The powerful computing effort can test potential drug therapies, a technique known as computational drug design.

Bowman said he is optimistic about this effort because the team previously found a "druggable" target in the Ebola virus and because COVID-19 is structurally similar to the SARS virus which has been the subject of many studies.

"The best opportunity for the near-term future is if we can find an existing drug that can bind to one of these sites," he said.

"If that happens it could be used right away."

This is likely to include drugs like the antimalarials chloroquine and hydroxychloroquine which may be "repurposed" for COVID-19.

Bowman said the project has been able to boost its power to some 400 petaflops—with each petaflop having a capacity to carry out one quadrillion calculations per second—or three times more powerful than the world's top supercomputers.

Other supercomputers are also working in parallel. The Oak Ridge National Laboratory said earlier this month that by using IBM's most powerful supercomputer it had identified 77 potential compounds that could bind to the main "spike" protein of the coronavirus to disarm the pathogen.

Researchers using powerful computer analysis are seeking to better understand the molecular structure of COVID-19 to help find a treatment

'No end' to compute power


The Folding@Home project is fueled by crowdsourced computing power from people's desktops, laptops and even PlayStation consoles, as well as more powerful business computers and servers.

"There is no end to the compute power than we can use in principle," Bowman said. Large tech firms including Microsoft-owned GitHub are also participating, and the project is in discussions with others.

Anyone with a relatively recent computer can contribute by installing a program which downloads a small amount of data for analysis. People can choose which disease they wish to work on.

"It's like bitcoin mining, but in the service of humanity," said Quentin Rhoads-Herrera of the security firm Critical Start, which has provided its powerful password "hash cracker" computer designed to decrypt passwords to the project.

Rhoads-Herrera said his team of security researchers, sometimes described as "white hat hackers," were encouraging more people to get involved.

Chipmaking giant Nvidia has urged gamers to join the crowdsourced computing effort by donating idle computing time on their powerful gaming computers

Fighting helplessness

Computer chipmaker Nvidia, which makes powerful graphics processors for gaming devices, called on gamers to join the effort as well.

"The response has been record-breaking, with tens of thousands of new users," joining, said Nvidia spokesman Hector Marinez.

One of the largest contributions comes from a Reddit group of PC enthusiasts and gamers which has some 24,000 members participating.

"It is a fantastic weapon against the feeling of helplessness," said Pedro Valadas, a lawyer in Portugal who heads the Reddit community and is a part of the project's advisory board.

"The fact that anyone, at home, with a computer, can play a role and help fight against (disease) for the common good is a powerful statement," Valadas told AFP.
Crowd-sourced computer network delves into protein structure, seeks new disease therapies

© 2020 AFP

Impact of a second Dust Bowl would be felt worldwide

by Frontiers

Credit: CC0 Public Domain

The American Dust Bowl of the 1930s—captured by the novels of John Steinbeck—was an environmental and socio-economic disaster that worsened the Great Depression.

The Dust Bowl was an extreme event. But due to climate change, massive crop failures are more likely to happen again in the future. New research in Frontiers in Sustainable Food Systems aimed to answer what these impacts may look like.

The Dust Bowl was centered on the Great Plains of the USA, where decades of unsustainable deep plowing had displaced native, moisture-retaining grasses. An atypical La Niña then brought intense droughts, high temperatures, and strong winds which blew away the topsoil in the form of large-scale dust storms.

Apart from its direct impact on people (around 7,000 deaths and two million homeless), the Dust Bowl had a catastrophic effect on crops where wheat and maize production in the USA plummeted by 36% and 48% during the 1930s.

Currently, the Intergovernmental Panel on Climate Change predicts that in another three to four decades that most of the USA will have further warmed by 1.5-2 °C. This compounds issues that already exist today, where global food security is under pressure from the increased frequency of extreme weather events.

"We wanted to forecast how a multi-year production decline in a major exporting country, similar to that which occurred during the Dust Bowl, would affect modern food supplies globally via international trade," says first author Dr. Alison Heslin, a postdoctoral researcher at the Center for Climate Systems Research of Columbia University and NASA's Goddard Institute for Space Studies.

"In today's system of global food trade, disruptions are not bound by borders. Shocks to production are expected to affect trade partners who depend on imports for their domestic food supply."

To assess the possible impacts of a second dust bowl, the authors first developed two alternative computer simulations of the worldwide trade in wheat. They then delivered a shock to these model systems in the form of a four-year-long Dust Bowl-like anomaly, restricted to the USA.

Under one simulation, countries first use their reserves and then divide the absorbed shock between imports and exports, propagating it in one direction by increasing imports and in another by decreasing exports.

Under the more complicated second model, the USA first reduces only its exports, propagating the shock to all receiving trade partners, after which all countries with a shortage respond by increasing their imports.

Their results predict a severity similar to that of the original event, estimated from historical data. The results show that the USA would fully exhaust 94% of its reserves over the first four years of a Dust Bowl-liked agricultural shock.

They also show that without exception, all countries to which the USA exports wheat would decrease their reserves, even though they didn't themselves suffer crop failure.

"We focused on a subset of the possible impacts, specifically changes in trade, drawing down strategic reserves and decreases in consumption," says co-author Dr. Jessica Gephart, Assistant Professor at the Department of Environmental Science of the American University in Washington DC.

"We found that global wheat trade contracts and shifts toward other wheat exporters, and that wheat reserves around the world decline, in many cases to zero. This suggests that the impacts would not only raise prices for US consumers but would also raise prices far beyond the US borders," says Gephart.

Key impacts of another four-year dust bowl could include an initial 31% loss of global wheat stocks, and by the end of the four years, between 36-52 countries could have used up over 75% of their starting reserves. The 10 countries with the highest initial reserves (China, USA, India, Iran, Canada, Russia, Morocco, Australia, Egypt, Algeria) would see their reserves decline by 15-22 % relative to the starting points.

However, a silver lining is that due to the high initial starting point of global reserves, most supply shocks, even in countries without reserves, could be addressed through trade flow adjustments without reducing consumption.

"Our results remind us that mitigating climate risks requires accounting for not only the direct effects of climate change, like local extreme weather events, but also the climate impacts which travel through our interconnected system of global trade."

"In the context of food security, we show that accessing food reserves can, for a time, buffer populations from trade-induced supply shortages but as reserves deplete, people are at risk of food shortages," says Heslin.

Climate change and the threat to global breadbaskets

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More information: Frontiers in Sustainable Food Systems, DOI: 10.3389/fsufs.2020.00026 , https://www.frontiersin.org/articles/10.3389/fsufs.2020.00026/full

Hidden source of carbon found at the Arctic coast

by University of Texas at Austin 

Credit: CC0 Public Domain

A previously unknown significant source of carbon just discovered in the Arctic has scientists marveling at a once overlooked contributor to local coastal ecosystems—and concerned about what it may mean in an era of climate change.

In a Nature Communications paper released today, aquatic chemists and hydrologists from The University of Texas at Austin's Marine Science Institute and Jackson School of Geosciences, U.S. Fish and Wildlife Service and Florida State University present evidence of significant, undetected concentrations and fluxes of dissolved organic matter entering Arctic coastal waters, with the source being groundwater flow atop of frozen permafrost. This water moves from land to sea unseen, but researchers now believe it carries significant concentrations of carbon and other nutrients to Arctic coastal food webs.

Groundwater is known globally to be important for delivering carbon and other nutrients to oceans, but in the Arctic, where much water remains trapped in frozen earth, its role has been less clear. Scientists were surprised to learn that groundwater may be contributing an amount of dissolved organic matter to the Alaskan Beaufort Sea that is almost on a par with what comes from neighboring rivers during the summer.

"We have to start thinking differently about groundwater," said senior author Jim McClelland, professor of marine sciences at UT Austin. "The water that flows from rivers to the Arctic Ocean is pretty well accounted for, but until now the groundwater flowing to this ocean hasn't been."

The research community has generally assumed that groundwater inputs from land to sea are small in the Arctic because perennially frozen ground, or permafrost, constrains the flow of water below the tundra surface.

The research published today describes sampling the concentration and age of dissolved carbon, as well as nitrogen, in groundwater flowing beneath the land's surface in the Arctic during the summer. The team found that as shallow groundwater flows beneath the surface at sites in northern Alaska, it picks up new, young organic carbon and nitrogen as expected. However, they also discovered that as groundwater flows toward the ocean, it mixes with layers of deeper soils and thawing permafrost, picking up and transporting century-to-millennia old organic carbon and nitrogen.

This old carbon being transported by groundwater is thought to be minimally decomposed, never having seen the light of day before it meets the ocean.

"Groundwater inputs are unique because this material is a direct shot to the ocean without seeing or being photodegraded by light," McClelland said. "Sunlight on the water can decompose organic carbon as it travels downstream in rivers. Organic matter delivered to the coastal ocean in groundwater is not subject to this process, and thus may be valuable as a food source to bacteria and higher organisms that live in Arctic coastal waters."

The researchers concluded that the supply of leachable organic carbon from groundwater amounts to as much as 70% of the dissolved organic matter flux from rivers to the Alaska Beaufort Sea during the summer.

"Despite its ancient age, dissolved organic carbon in groundwater provides a new and potentially important source of fuel and energy for local coastal food webs each summer," said lead author Craig Connolly, a recent graduate of UT Austin's Marine Science Institute. "The role that groundwater inputs play in carbon and nutrient cycling in Arctic coastal ecosystems, now and in the future as climate changes and permafrost continues to thaw, is something we hope will spark research interest for years to come."

Co-author M. Bayani Cardenas, a professor in the Jackson School of Geosciences, said that climate change's outsized effect on the Arctic makes groundwater research all the more important.

"The Arctic is heating up twice as much as the rest of the planet. With that comes permafrost thawing and the birth of aquifers," he said. "It is likely that groundwater transport in the Arctic will be more and more important in the future."

Fresh groundwater flow important for coastal ecosystems

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More information: Nature Communications (2020). DOI: 10.1038/s41467-020-15250-8

Geologists find lost fragment of ancient continent in Canada's North
by University of British Columbia

Geologists studying rock samples from Baffin Island find lost fragment of continent. Credit: istock

Sifting through diamond exploration samples from Baffin Island, Canadian scientists have identified a new remnant of the North Atlantic craton—an ancient part of Earth's continental crust.

A chance discovery by geologists poring over diamond exploration samples has led to a major scientific payoff.

Kimberlite rock samples are a mainstay of diamond exploration. Formed millions of years ago at depths of 150 to 400 kilometers, kimberlites are brought to the surface by geological and chemical forces. Sometimes, the igneous rocks carry diamonds embedded within them.

"For researchers, kimberlites are subterranean rockets that pick up passengers on their way to the surface," explains University of British Columbia geologist Maya Kopylova. "The passengers are solid chunks of wall rocks that carry a wealth of details on conditions far beneath the surface of our planet over time."

But when Kopylova and colleagues began analyzing samples from a De Beers Chidliak Kimberlite Province property in southern Baffin Island, it became clear the wall rocks were very special. They bore a mineral signature that matched other portions of the North Atlantic craton—an ancient part of Earth's continental crust that stretches from Scotland to Labrador.

"The mineral composition of other portions of the North Atlantic craton is so unique there was no mistaking it," says Kopylova, lead author of a new paper in the Journal of Petrology that outlines the findings. "It was easy to tie the pieces together. Adjacent ancient cratons in Northern Canada—in Northern Quebec, Northern Ontario and in Nunavut—have completely different mineralogies."

Cratons are billion-year old, stable fragments of continental crust—continental nuclei that anchor and gather other continental blocks around them. Some of these nuclei are still present at the center of existing continental plates like the North American plate, but other ancient continents have split into smaller fragments and been re-arranged by a long history of plate movements.

"Finding these 'lost' pieces is like finding a missing piece of a puzzle," says Kopylova. "The scientific puzzle of the ancient Earth can't be complete without all of the pieces."

The continental plate of the North Atlantic craton rifted into fragments 150 million years ago, and currently stretches from northern Scotland, through the southern part of Greenland and continues southwest into Labrador.

The newly identified fragment covers the diamond bearing Chidliak kimberlite province in southern Baffin Island. It adds roughly 10 percent to the known expanse of the North Atlantic craton.

This is the first time geologists have been able to piece parts of the puzzle together at such depth—so called mantle correlation. Previous reconstructions of the size and location of Earth's plates have been based on relatively shallow rock samples in the crust, formed at depths of one to 10 kilometers.

"With these samples we're able to reconstruct the shapes of ancient continents based on deeper, mantle rocks," says Kopylova. "We can now understand and map not only the uppermost skinny layer of Earth that makes up one percent of the planet's volume, but our knowledge is literally and symbolically deeper. We can put together 200-kilometer deep fragments and contrast them based on the details of the deep mineralogy."

The samples from the Chidliak Kimberlite Province in southern Baffin Island were initially provided by Peregrine Diamonds, a junior exploration company. Peregrine was acquired by the international diamond exploration company and retailer De Beers in 2018. The drill cores sample themselves are very valuable, and expensive to retrieve.

"Our partner companies demonstrate a lot of goodwill by providing research samples to UBC, which enables fundamental research and the training of many grad students," says Kopylova. "In turn, UBC research provides the company with information about the deep diamondiferous mantle that is central to mapping the part of the craton with the higher changes to support a successful diamond mine."Hidden past of Earth's oldest continents unearthed

More information: M G Kopylova et al. The metasomatized mantle beneath the North Atlantic Craton: Insights from peridotite xenoliths of the Chidliak kimberlite province (NE Canada), Journal of Petrology (2019). DOI: 10.1093/petrology/egz061

Geologists find a lost fragment of an ancient continent filled with diamonds that formed part of Earth's 

continental crust 2.7 billion years ago in Canada's North Atlantic

Scientists find a diamond-filled hunk of the 2.7B-year-old North Atlantic Craton

The NAC forms part of the Earth's ancient crust that is now deep underground 

The sample at a depth of more than 100 miles helps reconstruct Earth's geology

By JONATHAN CHADWICK FOR MAILONLINE  20 March 2020

Diamond-encrusted rock samples that have been found on a Canadian island fill ‘a piece in the puzzle’ to reconstruct an ancient part of Earth's continental crust.

A fragment of the North Atlantic Craton (NAC) was found by geologists who were sifting through diamond exploration samples from the southern Baffin Island, Canada.
The NAC is an ancient part of Earth’s continental crust that reaches around the top of the northern hemisphere, from Scotland to the Canadian region of Labrador, deep underground.

Researchers believe the NAC is up to 2.7 billion years old before its continental plate broke up around 150 million years ago.

Evidence of the ancient crust – which has previously been found in Scotland, Greenland and Labrador – is much sought after.

The new sample of kimberlite, a type of igneous rock, showed unmistakable properties similar to other portions of the NAC, the researchers said.

The University of British Columbia researchers say the rock samples from Canada's Baffin Island (pictured) are like 'a missing piece of a puzzle'

The rock is from the North Atlantic Craton - an ancient part of the Earth's continental crust, now deep underground, that stretches from the southern tip of Baffin Island to the very north of Scotland

The fragment adds about 10 percent to the known expanse of the NAC and also helps reconstruct mysterious shapes of Earth’s ancient continental crust.

WHAT IS KIMBERLITE?

Kimberlite is a dark-coloured, heavy fragmented rock that contains diamonds.

It often has rounded crystals surrounded by a fine-grained matrix of groundmass.

It is a type of igneous rock - rock that is formed through the cooling and solidification of magma or lava.

It's named after the town of Kimberley in South Africa, where the discovery of an 83.5-carat diamond called in 1869 spawned a diamond rush.

Kimberlite is still sought after and drives multi-million dollar mining operations.

‘The mineral composition of other portions of the North Atlantic Craton is so unique there was no mistaking it,’ said University of British Columbia geologist Maya Kopylova.

‘It was easy to tie the pieces together. Adjacent ancient cratons in northern Canada – in northern Qubec, northern Ontario and Nunavut – have completely different mineralogies.’

‘Finding these “lost” pieces is like finding a missing piece of a puzzle.'

The NAC was present as a single continent before it split into many fragments by emerging seas and oceans, Professor Kopylova told MailOnline, and the same process is now splitting the Arabian peninisula from East Africa.

Kimberlite rock samples – which are not just located in Canada – are described as a mainstay of diamond exploration.

They were formed millions of years ago at depths of 90 to 640 miles (150 to 400 kilometres).

These igneous rocks were brought to the surface by geological and chemical forces, sometimes with diamonds embedded in them.

The new ‘diamondiferous’ – or diamond-bearing – fragment covers Baffin Island’s Chidliak kimberlite province.

The Chidliak mining project, approximately 120 km northeast of Iqaluit, the capital of Nunavut territory, is now owned by diamond retail giant De Beers.

‘For researchers, kimberlites are subterranean rockets that pick up passengers on their way to the surface,’ said Professor Kopylova.

‘The passengers are solid chunks of wall rocks that carry a wealth of details on conditions far beneath the surface of our planet over time.’

An example of kimberlite, an igneous rock that contain diamonds. As well as being valuable to diamond retailers, kimberlite rock samples can help reconstruct the shapes of ancient continents

Previous reconstructions of the size and location of Earth’s plates have been based on fairly shallow rock samples in the crust that were formed at depths of about 0.5 to six miles.

‘With these samples we’re able to reconstruct the shapes of ancient continents based on deeper, mantle rocks,’ she said.

‘We can now understand and map not only the uppermost skinny layer of Earth that makes up one per cent of the planet’s volume, but our knowledge is literally and symbolically deeper.'

The samples were provided by Peregrine Diamonds, a Canada-based mineral exploration company, which was acquired by De Beers in 2018.


De Beers Canada acquired the Chidliak Project in September 2018 as part of the purchase of Peregrine Diamonds Ltd

Professor Kopylova said that the samples are now loaned out to the University of British Columbia by the company for research purposes.

‘In turn, UBC research provides the company with information about the deep diamondiferous mantle that is central to mapping the part of the craton with the higher changes to support a successful diamond mine.’

The findings have been detailed in the Journal of Petrology.

WHAT ARE CRATONS?

Cratons are the mantle underlying the oldest portions of the Earth, and establishing their composition and structure has been called one of the greatest challenges to earth sciences.

They’re stable fragments of continental crust – ‘nuceli’ that anchors and gathers other continental blocks around them.

Some of these nuclei are still present at the centre of existing continental plates, but other ancient continents have been split into smaller fragments and rearranged by plate movements.

‘The scientific puzzle of the ancient Earth ‘can’t be complete without all of the pieces’, said Professor Kopylova.

The continental plate of the North Atlantic Craton tore apart into fragments 150 million years ago and currently stretches from northern Scotland to the southern part of Greenland and southwest into Labrador.

Read more: metasomatized mantle beneath the North Atlantic Craton: Insights from peridotite xenoliths of the Chidliak kimberlite province (NE Canada) | Journal of Petrology | Oxford Academic

Initial findings of artificial impact on asteroid Ryugu

by Bob Yirka , Phys.org

Credit: JAXA

A large team of researchers affiliated with multiple institutions across Japan has revealed the age of the asteroid Ryugu and other characteristics by firing a copper ball at its surface. In their paper published in the journal Science, the group describes what they have learned so far from their attempt to mimic the conditions in which craters form.


Back in 2014, Japan's JAXA space agency launched the space probe Hayabusa2—its mission was to travel to the asteroid Ryugu and learn more about it. The probe arrived at the asteroid two years ago and began its surveying mission. One of its tasks involved firing a 2-kilogram copper ball at the asteroid at 7,200 km/h. The goal was to learn more about how craters form and to learn more about the structure of Ryugu. The tennis-ball sized projectile blasted a crater onto the surface of the asteroid 14.5 meters wide and 2.3 meters deep. It also generated a brief debris cloud. In analyzing the material in the debris cloud and in the bottom and sides of the craters, the researchers have been able to learn more about the makeup of the asteroid.

The researchers found sand-like material under the rocky surface, adding credence to theories that have suggested Ryugu is a "rubble pile" type of asteroid, formed from the materials left over when a larger body is destroyed by a collision with another body. The researchers also noted that the crater was not round, but was instead more crescent-shaped, suggesting that one of its edges abuts a very large underground rock that was hard enough to avoid being fractured by the projectile.



PlayEjecta curtain growth and deposition on Ryugu. Credit: JAXA, Kobe University, Chiba Institute of Technology, Kochi University, University of Occupational and Environmental Health

The finding of sand-like material also suggests the asteroid is likely much younger than some had speculated prior to the Hayabusa2 mission. The researchers now believe it to be approximately 9 million years old. The team also noted that the formation of the crater was limited by gravity, not surface strength, again suggesting that the asteroid is made of fragile, porous material. They pointed out that the crater created by the projectile was approximately seven times bigger than it would have been on Earth, which has a much harder surface.


Explore furtherJapan spacecraft releases rover to asteroid in last mission
More information: M. Arakawa et al. An artificial impact on the asteroid 162173 Ryugu formed a crater in the gravity-dominated regime, Science (2020). DOI: 10.1126/science.aaz1701
Journal information: Science



© 2020 Science X Network

Epigenetic inheritance: A 'silver bullet' against climate change?

by Helmholtz Association of German Research Centres

Three-spined sticklebacks are used as model organisms in this study. Credit: M. Heckwolf, GEOMAR

The current pace of climate change exceeds historical events by 1-2 orders of magnitude, which will make it hard for organisms and ecosystems to adapt. For a long time, it has been assumed that adaptation was only possible by changes in the genetic makeup—the DNA base sequence. Recently, another information level of DNA, namely epigenetics, has come into focus.

Using a fish species from the Baltic Sea, the three-spined stickleback, an international team investigated whether and how epigenetics contributes to adaptation. "Our experiment shows that epigenetic modifications affect adaptation, but also that the changes from one generation to the next are smaller than previously assumed," says biologist Dr. Melanie Heckwolf from GEOMAR Helmholtz Centre for Ocean Research Kiel. She is one author of the study, which has now been published in Science Advances.

But what distinguishes changes in DNA from changes in epigenetics? "Individuals with certain heritable traits encoded in DNA can cope with the prevailing environment better than others. On average, those individuals can cope better with their environment, hence survive longer and produce more offspring. In the long run, their characteristics encoded in the DNA will prevail. This process refers to natural selection," explains Dr. Britta Meyer from GEOMAR. However, selection requires time, and time is scarce in the face of rapid climate change.

In contrast, epigenetic processes chemically influence the structure of DNA. They activate or deactivate areas of the genome that are responsible for certain traits or responses to environmental conditions. On the one hand, 'stable' epigenetic markers, through natural selection, contribute to adaptation in a similar way as the DNA itself. On the other hand, 'inducible' markers are those that can change during the life of an individual. In theory, if this happens in the gametes of parents, their offspring are given an advantage to cope with their environment. Many scientists therefore expect that inducible markers will react particularly quickly and thus ensure the survival of organisms in the face of rapid changes.

The research groups of Prof. Dr. Thorsten Reusch (GEOMAR, Germany) and Dr. Christophe Eizaguirre (Queen Mary University of London, UK) have investigated whether and how these stable and inducible markers contribute to adaptation. They use the Baltic three-spined stickleback fish because it is currently adapted to different salinity conditions ranging from saltwater to freshwater. Further, the Baltic Sea is a natural laboratory for climate change research because the effects of climate change are already evident there.

"In order to understand how fish respond to the consequences of climate change, we collected stickleback populations from different regions of the North and Baltic Seas with different salinity levels," explains Dr. Meyer. The team found that the different populations differed in their genetic and epigenetic makeups and also had different tolerances to changes in salinity. In an experiment involving two generations of sticklebacks, the team was also able to show that inducible markers improve the response of the second generation to environmental change, albeit to a lesser extent than initially assumed.

Overall, the study shows that organisms will eventually reach their limits to respond to climate change, even with epigenetic modes of adaptation. "We have to be careful not to overinterpret this exciting but poorly understood field of research in epigenetics as a silver bullet against climate change for all species," says Melanie Heckwolf. "Climate change is one of the greatest challenges for species and ecosystems, and the natural mechanisms available to species to respond may not be sufficient if climate change remains so strong and rapid."

Researchers find new method to allow corals to rapidly respond to climate change
More information: "Two different epigenetic information channels in wild three-spined sticklebacks are involved in salinity adaptation" Science Advances (2020). DOI: 10.1126/sciadv.aaz1138 , https://advances.sciencemag.org/content/6/12/eaaz1138

Curiosity Mars rover takes a new selfie before record climb

by Andrew Good, Jet Propulsion Laboratory

This selfie was taken by NASA's Curiosity Mars rover on Feb. 26, 2020 (the 2,687th Martian day, or sol, of the mission). The crumbling rock layer at the top of the image is "the Greenheugh Pediment," which Curiosity climbed soon after taking the image. Credit: NASA/JPL-Caltech/MSSS 

NASA's Curiosity Mars rover recently set a record for the steepest terrain it's ever climbed, cresting the "Greenheugh Pediment," a broad sheet of rock that sits atop a hill. And before doing that, the rover took a selfie, capturing the scene just below Greenheugh.

In front of the rover is a hole it drilled while sampling a bedrock target called "Hutton." The entire selfie is a 360-degree panorama stitched together from 86 images relayed to Earth. The selfie captures the rover about 11 feet (3.4 meters) below the point where it climbed onto the crumbling pediment.

Curiosity finally reached the top of the slope March 6 (the 2,696th Martian day, or sol, of the mission). It took three drives to scale the hill, the second of which tilted the rover 31 degrees—the most the rover has ever tilted on Mars and just shy of the now-inactive Opportunity rover's 32-degree tilt record, set in 2016. Curiosity took the selfie on Feb. 26, 2020 (Sol 2687).

Since 2014, Curiosity has been rolling up Mount Sharp, a 3-mile-tall (5-kilometer-tall) mountain at the center of Gale Crater. Rover operators at NASA's Jet Propulsion Laboratory in Southern California carefully map out each drive to make sure Curiosity will be safe. The rover is never in danger of tilting so much that it would flip over—Curiosity's rocker-bogie wheel system enables it to tilt up to 45 degrees safely—but the steep drives do cause the wheels to spin in place.

This video shows how the robotic arm on NASA's Curiosity Mars rover moves as it takes a selfie. Credit: NASA/JPL-Caltech

How Are Selfies Taken?

Before the climb, Curiosity used the black-and-white Navigation Cameras located on its mast to, for the first time, record a short movie of its "selfie stick," otherwise known as its robotic arm.

Curiosity's mission is to study whether the Martian environment could have supported microbial life billions of years ago. One tool for doing that is the Mars Hand Lens Camera, or MAHLI, located in the turret at the end of the robotic arm. This camera provides a close-up view of sand grains and rock textures, similarly to how a geologist uses a handheld magnifying glass for a closer look in the field on Earth.

In this video, JPL imaging specialist Justin Maki explains how NASA's Mars Curiosity rover takes a selfie. Credit: NASA/JPL-Caltech

By rotating the turret to face the rover, the team can use MAHLI to show Curiosity. Because each MAHLI image covers only a small area, it requires many images and arm positions to fully capture the rover and its surroundings.

"We get asked so often how Curiosity takes a selfie," said Doug Ellison, a Curiosity camera operator at JPL. "We thought the best way to explain it would be to let the rover show everyone from its own point of view just how it's done.Curiosity Mars rover snaps its highest-resolution panorama yet