Earth

Since their invention more than 60 years ago, diamond anvil cells have made it possible for scientists to recreate extreme phenomena - such as the crushing pressures deep inside the Earth's mantle - or to enable chemical reactions that can only be triggered by intense pressure, all within the confines of a laboratory apparatus that you can safely hold in the palm of your hand.

To develop new, high-performance materials, scientists need to understand how useful properties, such as magnetism and strength, change under such harsh conditions. But often, measuring these properties with enough sensitivity requires a sensor that can withstand the crushing forces inside a diamond anvil cell.

Since 2018, scientists at the Center for Novel Pathways to Quantum Coherence in Materials (NPQC), an Energy Frontier Research Center led by the U.S. Department of Energy's Lawrence Berkeley National Laboratory (Berkeley Lab), have sought to understand how the properties of electronic and optical materials can be harnessed to develop ultrasensitive sensors capable of measuring electric and magnetic fields.

Now, a team of scientists led by Berkeley Lab and UC Berkeley, with support from the NPQC, have come up with a clever solution: By turning natural atomic flaws inside the diamond anvils into tiny quantum sensors, the scientists have developed a tool that opens the door to a wide range of experiments inaccessible to conventional sensors. Their findings, which were reported in the journal Science, have implications for a new generation of smart, designer materials, as well as the synthesis of new chemical compounds, atomically fine-tuned by pressure.

Turning atomic flaws into sensors

At the atomic level, diamonds owe their sturdiness to carbon atoms bound together in a tetrahedral crystal structure. But when diamonds form, some carbon atoms can get bumped out of their "lattice site," a space in the crystal structure that is like their assigned parking spot. When a nitrogen atom impurity trapped in the crystal sits adjacent to an empty site, a special atomic defect forms: a nitrogen-vacancy (NV) center.

Over the last decade, scientists have used NV centers as tiny sensors to measure the magnetism of a single protein, the electric field from a single electron, and the temperature inside a living cell, explained Norman Yao, faculty scientist in Berkeley Lab's Materials Sciences Division and assistant professor of physics at UC Berkeley.

To take advantage of the NV centers' intrinsic sensing properties, Yao and colleagues engineered a thin layer of them directly inside the diamond anvil in order to take a snapshot of the physics within the high-pressure chamber.

Imaging stress inside the diamond anvil cell

After generating a layer of NV center sensors a few hundred atoms in thickness inside one-tenth-carat diamonds, the researchers tested the NV sensors' ability to measure the diamond anvil cell's high-pressure chamber.

The sensors glow a brilliant shade of red when excited with laser light; by probing the brightness of this fluorescence, the researchers were able to see how the sensors responded to small changes in their environment.

What they found surprised them: The NV sensors suggested that the once-flat surface of the diamond anvil began to curve in the center under pressure.

Co-author Raymond Jeanloz, professor of earth and planetary science at UC Berkeley, and his team identified the phenomenon as "cupping" - a concentration of the pressure toward the center of the anvil tips.

"They had known about this effect for decades but were accustomed to seeing it at 20 times the pressure, where you can see the curvature by eye," Yao said. "Remarkably, our diamond anvil sensor was able to detect this tiny curvature at even the lowest pressures."

There were other surprises, too. When a methanol/ethanol mixture they squeezed underwent a glass transition from a liquid to a solid, the diamond surface turned from a smooth bowl to a jagged, textured surface. Mechanical simulations performed by co-author Valery Levitas of Iowa State University and Ames Laboratory confirmed the result.

"This is a fundamentally new way to measure phase transitions in materials at high pressure, and we hope this can complement conventional methods that utilize powerful X-ray radiation from a synchrotron source," said lead author Satcher Hsieh, a doctoral researcher in Berkeley Lab's Materials Sciences Division and in the Yao Group at UC Berkeley.

Co-lead authors with Hsieh are graduate student researcher Prabudhya Bhattacharyya and postdoctoral researcher Chong Zu of the Yao Group at UC Berkeley.

Magnetism under pressure

In another experiment, the researchers used their array of NV sensors to capture a magnetic "snapshot" of iron and gadolinium.

Iron and gadolinium are magnetic metals. Scientists have long known that compressing iron and gadolinium can alter them from a magnetic phase to a nonmagnetic phase, an outcome of what scientists call a "pressure-induced phase transition." In the case of iron, the researchers directly imaged this transition by measuring the depletion of the magnetic field generated by a micron-size (or one millionth of a meter) bead of iron inside the high-pressure chamber.

In the case of gadolinium, the researchers took a different approach. In particular, the electrons inside gadolinium "happily whiz around in random directions," and this chaotic "mosh pit" of electrons generates a fluctuating magnetic field that the NV sensor can measure, Hsieh said.

The researchers noted that the NV center sensors can flip into different magnetic quantum states in the presence of magnetic fluctuations, much like how a compass needle spins in different directions when you wave a bar magnet near it.

So they postulated that by timing how long it took for the NV centers to flip from one magnetic state to another, they could characterize the gadolinium's magnetic phase by measuring the magnetic "noise" emanating from the gadolinium electrons' motion.

They found that when gadolinium is in a non-magnetic phase, its electrons are subdued, and its magnetic field fluctuations hence are weak. Subsequently, the NV sensors stay in a single magnetic quantum state for a long while - nearly a hundred microseconds.

Conversely, when the gadolinium sample changed to a magnetic phase, the electrons moved around rapidly, causing the nearby NV sensor to swiftly flip to another magnetic quantum state.

This sudden change provided clear evidence that gadolinium had entered a different magnetic phase, Hsieh said, adding that their technique allowed them to pinpoint magnetic properties across the sample with submicron precision as opposed to averaging over the entire high-pressure chamber as in previous studies.

The researchers hope that this "noise spectroscopy" technique will provide scientists with a new tool for exploring phases of magnetic matter that can be used as the foundation for smaller, faster, and cheaper ways of storing and processing data through next-generation ultrafast spintronic devices.

Next steps

Now that they've demonstrated how to engineer NV centers into diamond anvil cells, the researchers plan to use their device to explore the magnetic behavior of superconducting hydrides - materials that conduct electricity without loss near room temperature at high pressure, which could revolutionize how energy is stored and transferred.

And they would also like to explore science outside of physics. "What's most exciting to me is that this tool can help so many different scientific communities," says Hsieh. "It's sprung up collaborations with groups ranging from high-pressure chemists to Martian paleomagnetists to quantum materials scientists."

Researchers from Berkeley Lab; UC Berkeley; Ludwig-Maximilian-Universität, Germany; Iowa State University; Carnegie Institution of Washington, Washington, D.C.; and Ames Laboratory participated in the work.

Safe nuclear waste storage, new ways of generating and storing hydrogen, and technologies for capturing and reusing greenhouse gases are all potential spinoffs of a new study by University of Guelph researchers.

Published recently in Nature Scientific Reports, the study involved the first-ever use of antimatter to investigate processes connected to potential long-term storage of waste from nuclear reactors, says lead author and chemistry professor Khashayar Ghandi.

The research may ultimately help in designing safer underground vaults for permanent storage of radioactive waste, including waste from Ontario's nuclear power plants. Those installations produce almost two-thirds of the province's energy needs.

"Nuclear energy provides a clean source of electricity. However, there is a need to deal with the nuclear waste from reactors that generate electricity," said Ghandi.

Currently, used nuclear fuel bundles - still highly radioactive -- are held in vaults in temporary storage.

Long-term, experts aim to use deep geological repositories to permanently entomb the material. Buried in rock formations hundreds of metres underground, the fuel containers would be held in engineered and natural barriers such as clays to shield people and the environment from radiation.

It takes almost 100,000 years for radioactivity from nuclear waste to return to the level of natural uranium in the ground. "It's important to understand the safest conditions for such storage systems," said Ghandi.

He and his students worked with collaborators at the French Alternative Energies and Atomic Energy Commission. Nuclear reactors provide more than 75 per cent of France's power needs.

The team studied radiation chemistry and electronic structure of materials at scales smaller than nanometres, or millionths of millimetres.

They prepared samples of clay in ultra-thin layers in his U of G lab. Working at the TRIUMF particle accelerator in Vancouver, the team bombarded the samples with antimatter subatomic particles called positive muons.

Based on these first-ever measurements at the accelerator, he said, the team's system is a proven tool that will enable radiation studies of material to be used to store nuclear waste. That's important for Canada, where the nuclear industry is looking to build its first geological repository by mid-century.

"This system can now be applied along with other measurements to determine and help to potentially design the best material for containers and barriers in nuclear waste management."

Ghandi said the study also showed intriguing properties of clays that may make them useful in other industries. Clays may serve as catalysts to change chemicals from one form to another - a benefit for petrochemical companies making various products from oil. Other industries might use clays to capture global-warming gases such as carbon dioxide and use those gases to make new products.

Clays might also be combined with other compounds to help store hydrogen as a clean energy source.

In all cases, Ghandi said, the research team's findings provide a new way to study sub-nano materials and chemical processes in confined environments.

New research has revealed that Australia's oldest flowering plants are 126 million years old and may have resembled modern magnolias, buttercups and laurels.

Undertaken by University of Melbourne palynologist, Dr Vera Korasidis, the study also found that Australia's first blooms got their foothold in 'high southern latitude' regions like the Otway and Gippsland ranges.

Dr Korasidis' research, "The rise of flowering plants in the high southern latitudes of Australia", reconstructed our earliest flower-bearing forests, from 126-100 million years ago, to conclude that climate change prevented or slowed the expansion of flowers into Australasia with the temperatures at the high southern latitudes too cold to support the earliest flowering plants.

The research also established that the first flowers related to 72 per cent of today's living angiosperm species that first appeared in southern Australia about 108 million years ago - 17 million years after the first flowers evolved in equatorial regions.

The world's oldest flower, Montsechia, is 130 million years old and was discovered in Spain.

"Our research, completed on dinosaur-bearing rocks throughout Victoria,suggests that warming temperatures allowed the first flowering plants to migrate to the cooler regions at the earth's poles," said Dr Korasidis.

"The true diversity of primitive flowers in southern near-polar settings has only just been discovered because 'sieving' practices resulted in pollen grains, produced by the earlier flowers, being 'rinsed down the sink' for over 50 years."

Dr Korasidis said the study would help to "piece together Australia's paleoclimate record and understand the interaction between climate, CO2 and the evolution of faunas and floras."

The age of southern Australia's polar vertebrates, including dinosaurs, has also now been determined and is 126-110 million years old based on this study and new research by fellow University of Melbourne palynologist and co-author, Dr Barbara Wagstaff.

Angiosperm pollen produced by the oldest flowers was recovered from numerous sites across Victoria indicating the large areal extent of flowers during the Early Cretaceous period. All material is housed in the Palaeontology collection at Museum Victoria in Melbourne.

Caribou, the North American cousin of reindeer, migrate farther than any terrestrial animal. They can cover thousands of miles as they move between winter feeding grounds and summer calving grounds. But many caribou herds are in decline as the warming climate changes much of the landscape they depend on. Inedible shrubs are rapidly encroaching on the tundra, and more frequent forest fires and disease are destroying the trees that provide caribou with lichen for food. The role of climate on their migration patterns has never been well understood, but knowing what drives caribou movements is crucial to predicting the future for the iconic species that plays a key roll the ecological and economic stability of the Arctic region.

A new study led by a University of Maryland biologist discovered two unexpected drivers for migration timing that dispute long-held assumptions and provide insight into potential future effects of climate change on caribou. First, the study found that caribou herds all across North America are triggered to start spring migration at roughly the same time by large-scale, ocean-driven climate cycles. Second, despite a synchronized start, arrival at their respective calving grounds depends on the previous summer's weather conditions. Warm, windless summers that favored insect pests lead to poorer maternal health and delayed arrivals at the calving grounds the following spring.

The study, which accounted for approximately 80% of all North American migratory caribou, is the largest caribou migration study to date. It was published in the December 12, 2019 issue of the journal Ecosphere.

"This was completely unexpected," said Eliezer Gurarie, an associate research scientist in UMD's Department of Biology and lead author of the study. "There was no reason to think that herds that calve near the Hudson Bay in the East would begin migration at the same time as the herds along coastal Western Alaska, or that summer conditions would play an important role in the following spring migration. Prior to this, it had been assumed that migration timing depends on some combination of snowmelt and availability of useful vegetation at the endpoint of the migration. Neither of those held up."

The findings could point to difficult times for caribou in the future if Arctic summers continue to warm as predicted.

"The summers are definitely getting warmer and more insect friendly," Gurarie said. "That is going to have consequences for these iconic animals down the road."

To understand what drives caribou migration, Gurarie analyzed tracking data from 1,048 individual caribou from 1995 to 2017. The data represent seven major herds that account for 80% of all North American caribou. The data was collected by the study's coauthors from the National Park Service, Alaska Department of Fish and Game, Yukon Government and Government of Northwest Territories. Gurarie correlated the tracking data to global climate indices, local weather conditions, snowmelt timing and vegetation.

The results revealed a clear pattern of synchronized departure. Later migration starts were associated with positive North Atlantic Oscillations in spring and summer, which tend to create cooler, dryer and less windy conditions. Earlier migration starts corresponded with two cycles: a positive Pacific Decadal Oscillation in the spring and previous summer, which tends to bring more snow and wind to the North; and a positive Arctic Oscillation, which strengthens the polar circulation and forces cold air and storms to remain farther north.

The relationship between these oscillations and weather on the ground is complex, but the study draws links that explain how regionwide seasonal conditions might influence migration. For example, the scientists found that across the Arctic, warm temperatures after a snowy winter delayed the start of migration, and Gurarie suggested this is likely because snowmelt softened the ground and made travel difficult.

"The whole departure story is linked to conditions that are most suitable for movement," Gurarie said. "It's less about whether or not there is snow on the ground and more about the conditions of the snow: Is it slushy and soupy and hard to travel through, or is it hardpacked and easier to walk on?"

Regardless of travel conditions at the start of migration, the study revealed that caribou arrive at their calving grounds when they are ready to give birth. (If they start migration early in the season, they tend not to rush. If they start late, they move nearly continuously to get to the calving grounds.) But caribou have variable gestation periods, so not all herds were ready to give birth at the same time, which meant some herds arrived at their respective calving grounds later than others. When the researchers compared arrival times with climate and weather data, they consistently found that caribou herds arrived at the calving grounds earlier when they experienced cool, windy conditions the previous summer.

"This connection to the previous summer's weather, particularly temperature and wind, kept coming up," Gurarie said. "When we looked closer at the biology and ecology of these animals, it became clear that this was tied to insect harassment and the physical condition of the caribou."

Insects are relentless pests during summer in the Arctic. Caribou spend a great deal of energy searching for relief from the mosquitos, botflies and warble flies that plague them. To avoid the insects, Caribou move en masse to higher ground or closer to the coast, or they wander in search of snow patches where there are fewer insects. All of that avoidance means much less eating.

During cooler, windier summers, caribou remain healthier because they spend less time avoiding insects and more time eating. Healthier caribou cows have more nutrient stores and shorter pregnancies, whereas caribou weakened by a tough summer of insect harassment have longer pregnancies and arrive at the calving grounds later. Unfortunately, herds that arrive late continue to be at a disadvantage, because their calves have less time on the summer feeding range to fatten up before migrating back to the winter range in the fall.

Previous studies of gestation and arrival at the calving grounds have focused on the availability of vegetation for forage, but Gurarie and his colleagues found that vegetation at the calving grounds had no impact on migration timing for the herds in their study.

"Ultimately, we analyzed satellite-tracked movement data and remotely sensed climate and weather data," Gurarie said. "Using these large-scale observational data, we pieced together a story about individual physical condition, gestation times and reproduction calving, which is really a story about behavior and physiology on a very large scale. In making these links, we ended up leaning on decades-old studies of caribou--papers from the '50s, '60s and '70s. We looked, for example, at relationships between diet and calving timing, at insects and feeding behavior, and at snow quality and movement."

Gurarie's excitement over the power of the data to help reveal the story of caribou migration is tempered by a looming question about what could happen to caribou as the climate continues to warm. The team's next steps are to analyze data on caribou birth and death rates to gain a clearer picture of how migration timing and environmental conditions affect caribou populations.

"Researchers have been studying caribou movement and ecology for decades, but the data are fragmentary," said William Fagan, professor and chair of the UMD Department of Biology and a co-author of the study. "This study shows that by synthesizing these data--from climate data, and remote tracking data to historical studies and biological data collected in the field by the various agencies that manage caribou across the continent--there are great opportunities to gain a more integrated portrait of this economically, culturally and ecologically important species."

The NASA/ESA Hubble Space Telescope has once again captured comet 2I/Borisov streaking through our solar system on its way back into interstellar space. At a breathtaking speed of over 175 000 kilometres per hour, Borisov is one of the fastest comets ever seen. It is only the second interstellar object known to have passed through the Solar System.

In October 2019, Hubble observed the comet at a distance of approximately 420 million kilometres from Earth. These new observations taken in November and December 2019 of the comet at a closer distance provide clearer insights into the details and dimensions of the interstellar visitor [1].

The first image shows the comet in front of a distant background spiral galaxy (2MASX J10500165-0152029). The galaxy's bright central core is smeared in the image because Hubble was tracking the comet. Borisov was approximately 326 million kilometres from Earth in this exposure. Its tail of ejected dust streaks off to the upper right.

The second image is Hubble's revisit observation of the comet near its closest approach to the Sun. There it was subjected to a greater degree of heating than it had ever experienced, after spending most of its life in the extreme cold of interstellar space. The comet is 298 million kilometres from Earth in this photo, near the inner edge of the asteroid belt. The nucleus, an agglomeration of ices and dust, is still too small to be resolved. The bright central portion is a coma made up of dust leaving the surface. The comet will make its closest approach to Earth in late December, when it will be at a distance of 290 million kilometres.

"Hubble gives us the best measure of the size of comet Borisov's nucleus, which is the really important part of the comet," said David Jewitt, a professor of planetary science and astronomy at the University of California Los Angeles, whose team has captured the best and sharpest images of this first interstellar comet. "Surprisingly, our Hubble images show that its nucleus is more than 15 times smaller than earlier investigations suggested it might be. The radius is smaller than half a kilometre. This is important because knowing the size helps us to determine the total number, and mass, of such objects in the Solar System, and in the Milky Way. Borisov is the first known interstellar comet, and we would like to know how many others there are."

Crimean amateur astronomer Gennady Borisov discovered the comet on 30 August 2019. After a week of observations by amateur and professional astronomers all over the world, the International Astronomical Union's Minor Planet Center computed an orbit for the comet which showed that it came from interstellar space. Until now, all catalogued comets have come either from a ring of icy debris at the periphery of our Solar System, called the Kuiper belt, or from the Oort cloud, a shell of icy objects which is thought to be in the outermost regions of our Solar System, with its innermost edge at about 2000 times the distance between the Earth and the Sun.

2I/Borisov may represent only the beginning of a series of discoveries of interstellar objects paying a brief visit to our Solar System. There may be thousands of such interstellar objects here at any given time; most, however, are too faint to be detected with present-day telescopes.

Observations by Hubble and other telescopes have shown that rings and shells of icy debris encircle young stars where planet formation is underway. A gravitational interaction between these comet-like objects and other massive bodies could cause them to hurtle deep into space where they go adrift among the stars.

SASKATOON--The heady aroma of magnolia blossoms and lotus flowers might have wafted to your nostrils if you had gone for a walk 56 million years ago in the lush green forest which covered Canada's northernmost islands.

Now covered in ice and snow, present-day Ellesmere and Axel Heiberg islands in Nunavut were once home to a vibrant, temperate forest, according to fossil research just published by University of Saskatchewan (USask) scientists.

"It's very surprising how similar these ancient polar forests were to some of our modern forests. I identified fossil plants related to many modern temperate trees: birch, alder, elms--even plants belonging to the grape family. Some of the fossils are related to trees now found only in east Asia," said paleobotanist Christopher West, a recent USask PhD graduate.

"The presence of these forests gives us an idea about what could happen over long periods of time if our modern climate continues to warm, and also how forest ecosystems responded to greenhouse climates in the distant past," said West.

West examined more than 5,000 fossil samples to develop the only comprehensive analysis of fossil plants ever undertaken from the Canadian Arctic.

"This research is the cumulative effort of almost 40 years of work on fossil plants of the Canadian North undertaken by me and my students, including 20 field seasons on Ellesmere and Axel Heiberg islands," said USask geologist Jim Basinger, who co-supervised the work with David Greenwood, USask adjunct professor of geology and Brandon University biology professor.

The results published today in the highly respected journal Palaeontographica B include identifications and detailed descriptions of 83 types of plants from high arctic latitudes in Canada during the early Eocene epoch, around 56 million years ago.

"We won't see a return to a forested polar region in our lifetimes, but it is important to remember that we as humans have become agents of climate change, and that our warming climate will have potentially dramatic effects on our modern ecosystems," said West.

While Earth was considerably warmer during the early Eocene, the continents were mostly situated where they are now, and northern latitudes would have had lengthy periods of darkness. Despite the nearly total lack of light, the forests persisted, likely because of just how warm it was.

"If we are able to understand how ecosystems long ago responded to global warming, we may be able to better predict how our own modern ecosystems will respond to our own rapidly warming climate," said West. "This research will also help climate modelers as they use data from the past to better understand our own climate."

The next steps in the research are to examine fossils from Axel Heiberg Island from a slightly younger vintage--roughly 45 million years old--to understand better the ancient impacts of that climate change.

A new study by researchers at the Columbia Center for Children's Environmental Health (CCCEH) at Columbia Mailman School of Public Health is the first to compile the estimated per-case costs of six childhood health conditions linked to air pollution--estimates that can be incorporated into benefits assessments of air pollution regulations and climate change mitigation policies. Results appear in the journal Environmental Research.

The study reports case-specific monetary estimates for preterm birth, low birth weight, asthma, autism spectrum disorder, attention-deficit/hyperactivity disorder, and IQ reduction in children--which scientific evidence shows are among the known or likely health consequences of prenatal and early childhood exposure to air pollution, 80 percent of which is attributable to burning of coal, oil, diesel and gas.

The researchers conducted a systematic review of the scientific literature published between January 1, 2000 and June 30, 2018 to identify relevant economic costs for these six adverse health outcomes in children. In all, they reviewed 1,065 papers from the U.S. and U.K. and identified 12 most relevant papers. They separately identified estimates of the lost lifetime earnings associated with the loss of a single IQ point.

The study cites previously published estimates ranging from $23,573 for childhood asthma not persisting into adulthood to $3,109,096 for a case of autism with a concurrent intellectual disability. The researchers also provide an example of cumulative costs: they calculate a savings of $267 million if the number of pre-term births in the United States attributable to PM2.5 (a measure of particulate matter--one of several harmful air pollutants) were reduced by just 1 percent.

The study authors prioritized monetary estimates that factored in both immediate medical costs and longer-term and broad societal costs. However, they acknowledge that their figures are likely underestimates because they don't adequately capture the long-term health and societal impacts--for example, effects over the full life-course or losses in economic productivity.

Despite the high burden of childhood illness, benefit-cost assessments of policies and other interventions have not adequately considered impacts in children--both in terms of avoided cases and avoided economic costs. For example, the air pollution-related child health outcomes considered in the Benefits Mapping and Analysis Program Community Edition (BenMAP-CE) of the U.S. Environmental Protection Agency have been limited to acute bronchitis, lower and upper respiratory symptoms, school day loss, and asthma exacerbation in children. Whereas the BenMAP program estimates lifetime costs of a case of adult chronic asthma at $53,607, the total cost of each case of childhood asthma that persists into adulthood is estimated at $91,954.

The World Health Organization estimates that more than 40 percent of the burden of environmentally related disease and more than 88 percent of the burden of climate change is borne by children younger than 5. In the U.S., disorders such as asthma and ADHD are prevalent in children and have been increasing over time, with asthma having a prevalence of about 8 percent and ADHD a prevalence of 10 percent. Even disorders with lower prevalence, such as autism, represent a growing public health concern, with about 1 in 60 U.S. children affected.

"Impacts on children's health are generally under-represented in benefits assessments related to environmental pollution," says study co-author Frederica Perera, PhD, professor of environmental health sciences and director of translational research at the Columbia Center for Children's Environmental Health. "Policies to clean our air and address the serious and escalating problem of climate change will yield numerous benefits for children's health and for the financial health of families and our nation."

Getting premature babies to breathe without assistance has always been a stressful mission for doctors. But by carefully ventilating babies with 100% oxygen researchers have found a way to jump-start these first independent moments.

Spontaneous breathing at birth is critical so that doctors can avoid using invasive respiratory interventions on fragile newborns. But hypoxia - a lack of adequate oxygen supply to the body - is a huge inhibitor of natural breathing and a particularly large risk for premature babies.

However, there may be hope on the horizon. Dr. Janneke Dekker and Prof. Arjan te Pas from the Leiden University Medical Centre, Netherlands and Prof. Stuart Hooper from Monash University, Australia have demonstrated how oxygen can be used to tackle this problem in two research studies, both of which feature in Frontiers in Pediatrics.

Most preterm infants need some kind of support at birth because of their low muscle strength and the fact that their lungs haven't fully developed. This assistance is generally provided non-invasively through the use of a facemask in order to avoid more complicated procedures that risk lung and brain injury. But to make the facemask effective, the preterm infants already need to be breathing on their own. So how to encourage this first breath?

It was thought that giving pure oxygen in the baby's first few moments may stimulate it to breathe deeper and more frequent, but the team needed to make sure the theory was sound in principal before moving onto clinical studies with human babies.

The first paper provided the groundwork. Dekker and colleagues divided 26 preterm rabbit kittens that had difficulty breathing into two groups that received non-invasive breathing support at birth. One group received 21% oxygen via a facemask (equivalent to the normal amount of oxygen in air) and the other received 100% oxygen. They found that giving pure oxygen immediately after birth resulted in more stable breathing as well as a better rate of breathing.

With these promising results in mind, Dekker turned her attention to clinical studies in humans.

In the second paper, Dekker used a similar technique for stimulating breathing in premature human babies. Like the first study, 52 premature babies were stabilized at birth and randomly assigned to two treatment groups. One received an initial oxygen concentration of 30% via a non-invasive facemask and the other group received an initial oxygen concentration of 100%. The amount of oxygen present in the baby's blood was measured by using a pulse oximetry probe and compared to the internationally recommended reference values. The facemask oxygen was then adjusted to maintain an oxygen level of the blood within these recommended ranges.

Their results matched their predictions: the premature babies in 100% O2 group had a higher rate of breathing effort as well as a better oxygenation rate, and ultimately needed less time of positive pressure ventilation. This meant that vital organs and tissues in these fragile infants were getting more of the precious oxygen they needed to survive and could be independent from assisted breathing sooner.

So why not give all babies 100% oxygen all the time? Because too much oxygen can also be a bad thing. It's known that high concentrations of oxygen over time can lead to hyperoxia - a potentially harmful situation that causes tissue damage. Dekker and colleagues were careful to avoid this by slowly decreasing - titrating -the excess amount of oxygen as it became clear the babies no longer need the support.

This careful balancing act of stimulating babies to breathe with excess oxygen, and then dialing it back once it's no longer needed could save lives in the future.

Before that can happen, Dekker notes that: "this clinical trial was not designed to demonstrate any significant differences in clinical outcomes, but rather provide knowledge on one of the factors that could improve breathing effort at birth. The next step will be to combine this new technique into a bundle of care and compare the outcome to current clinical practices."

While more research needs to be done before using the technique globally, Frontiers' Field Chief Editor Dr. Arjan te Pas says the findings are exciting in and of themselves:

"The finding that oxygenation is a dominant driver for breathing effort at birth is exciting as this offers the possibility to be more successful in supporting preterm infants in a non-invasive manner. The knowledge gained from this research could help us design future studies on improving the effectiveness of the use of oxygen at birth, without increasing the risks that are associated with hyperoxia."

The Belgian coastal dunes, a protected habitat of high conservation value, are getting severely impacted by one of its worst enemies amongst invasive species: the Oregon grape. To help mitigate the detrimental effect of this North American shrub invader, Belgian scientists carried out an experiment to assess the effectiveness of different management methods.

The Atlantic coastal dunes form a dynamic and diverse ecosystem, home to a large number of native species, many of which are regionally threatened. Embryonic dunes, shifting white dunes, moss dunes, dune grasslands, and dune slacks are considered high conservation value sites, according to the interpretation manual of European habitats. However, the dunes are highly affected by external influences, and one of the most important threats to their biodiversity are invasive non-native plant species. These plants often colonised the dunes as garden escapes or spread from garden waste dumps or public plantings. Oregon grape is one of the worst invaders amongst them.

In their study, published in the open-access journal NeoBiota, the scientists, led by Tim Adriaens and Sam Provoost of the Research Institute for Nature and Forest (INBO), focus on the management of the current populations of Oregon grape (Berberis aquifolium) in the Belgian coastal dunes, where the species has already managed to invade half of the 46 nature reserves and is starting to replace native vegetation. Such a negative effect on the biodiversity of the area requires practical management advice. Due to the high level of infestation of the dunes, the researchers recommend prompt eradication as the most appropriate management strategy. So far, however, it has been unclear which method would show the best effectiveness.

"Invasive shrub species exert an additional pressure on Belgian dune ecosystems, which are already highly fragmented by urbanisation. Oregon grape is one of the worst and should be tackled urgently before it gets out of control," says Tim Adriaens.

Having compared four previously suggested treatments: manual uprooting,
foliar herbicide application, stem cutting followed by herbicide and salt application, the scientists reported herbicide leaf treatment to be the most effective method. Manual removal by digging and treating stems with glyphosate showed medium effectiveness. Treating stems with a saturated salt solution appeared rather cosmetic. However, it's not that easy to choose which method would be the best to work with, since with herbicide use there are non-target effects on the environment, economy, and society to be considered.

"Individual clones are best treated with herbicide, large surface areas provide opportunities for landscape-scale ecological restoration, combining invasive shrub removal with sand dune creation," further explains Tim Adriaens.

In Belgium, Oregon grape was first recorded in the wild in 1906 and naturalised in the period 1920-1950. It has been spreading rapidly since the 1990s. This expansion might be linked to cultivated hybrids and global warming, with the latter leading to a lengthened growing season, suggest the scientists. The species likes calcareous soils. Along the Belgian coast, Oregon grape has mainly invaded grey dunes, scrub and woodland.

Thanks to its numerous blue berries, which are easily dispersed over long distances by songbirds, the plant can appear everywhere within the dunes sites, also in places hardly accessible to managers. With the help of a highly branched root system, the plants attach themselves firmly in the sand, which makes manual pulling of mature plants hardly possible and labor-intensive.

"Dune managers and scientists across Europe should unite to draft alert lists and prioritise established alien species for management," Tim says in conclusion.

In conclusion, the scientists highlight the importance of an EU-wide collaboration between scientific communities. Invasive species are not bothered by administrative borders and exchanging experiences on impact and management options is crucial to maintain dune ecosystems in good conservation status.

Described as "living rocks", giant land tortoises are lumbering beasts with a reputation for being sluggish in both speed and brainpower. But new research carried out by scientists from the Okinawa Institute of Science and Technology (OIST) suggests we have greatly underestimated the intelligence of these creatures, who can not only be trained but also have amazing powers of long-term recall.

"When first discovered, giant land tortoises were viewed as stupid because explorers could simply collect and store them on ships as a supply of fresh meat," said Dr Tamar Gutnick, first author of the study and a postdoctoral scholar in the OIST Physics and Biology Unit.

But Gutnick pointed out that there had been contradictory reports that hinted at their intellect. Darwin himself noted that Galapagos tortoises travelled long distances between where they ate, drank, slept or mud-bathed, requiring a good memory. Explorers also documented that they could be trained to stay in one place on the ships.

"We also observed firsthand that tortoises recognized their keepers, so we knew they were capable of learning," added Gutnick. "This research shows the rest of the world just how smart they are."

Teaching an old tortoise new tricks

The study, recently published in the journal Animal Cognition, is the culmination of almost a decade's worth of work, starting when Gutnick was a master's student at The Hebrew University and worked with Aldabra tortoises housed at Vienna Zoo.

"When I met the tortoises, I immediately fell in love with them," said Gutnick. "It was clear to me that they all had very distinct - and often cheeky - personalities."

In this latest research, Dr Tamar Gutnick and Dr Michael Kuba - who originally worked at Vienna Zoo and is now a staff scientist at OIST - trained Aldabra and Galapagos tortoises from Vienna Zoo and Zürich Zoo to perform three tasks of increasing difficulty. The researchers used a form of conditioning called positive reinforcement training, where they rewarded the tortoises for a correct action by treating them with their favorite food, such as carrot, red beet or dandelions.

For the first task, the scientists trained the tortoises to bite a colored ball on the end of a stick. Once mastered, the researchers then taught them to move towards and bite the colored ball, which was held around one to two meters away. For the final task, the scientists assigned each tortoise a unique color and trained the tortoises to choose the correctly colored ball, from two offered targets.

When the researchers tested the tortoises three months later, the tortoises immediately performed the first two tasks. Although they were unable to recall their correct individual colors for the third task, five out of six tortoises relearned which color ball to bite quicker than in the initial training, suggesting some residual memory.

The researchers also revisited three of the Aldabra tortoises they had trained nine years earlier which were still housed at Vienna Zoo. Remarkably, all three recalled the first two tasks, showing an incredible long-term recall ability befitting their long lifespan.

Who taught us? Another tortoise!

The long-term memory of the tortoises was not the only surprise in store for the researchers, as they also discovered that tortoises trained in groups learned faster than tortoises trained separately.

"This was a very unexpected result," said Gutnick. "Giant land tortoises are not known for being particularly social animals but the increase in learning speed was unmistakable."

The scientists speculate that giant land tortoises may gain important information in the wild, such as feeding and drinking locations, by watching other tortoises.

The only task where there was no clear benefit to learning in a group was the third task, as the researchers assigned each tortoise its own individual color. Therefore, the tortoises could not learn any useful information about which ball to bite by watching each other.

This result is the first documented evidence for social learning in Aldabra and Galapagos tortoises, highlighting how little scientists currently know about cognition in reptiles - a group often neglected by scientists due to a lack of availability.

"The problem is, you can't keep a giant tortoise in a lab," said Gutnick. "Thanks to zoos, we are able to gain access to these incredible creatures and explore reptile cognition further."

The recovery of pine marten in Ireland and Britain is reversing native red squirrel replacement by invasive grey squirrels, according to new research presented at the British Ecological Society's annual meeting in Belfast today.

Researchers at Queens University, Belfast and National Museums Northern Ireland have found red squirrels are responding positively to the increased presence of pine martens across Northern Ireland. So, where pine martens occur, it increases the chances of red squirrels occurring, simultaneously reducing the likelihood of grey squirrels being present.

Historically, persecution of pine marten and loss of their preferred habitat led to severe declines across Ireland and Britain. In Northern Ireland, small, remnant populations were all that remained, but today, the species is recovering, and this comeback may help ensure the long-term future of the red squirrel in Ireland.

Joshua Twining, who will be presenting the research at the conference, commented "the red squirrels 'positive response' is likely due to grey squirrel disappearance rather than red squirrels and pine martens working together." Pine martens eat both red and grey squirrels, though the key difference is that red squirrels have evolved alongside pine martens over millennia, making them able to coexist.

Twining said, "The ability of the pine marten to control the grey squirrel and help red squirrel recovery in Ireland and Britain is limited by three things; its ongoing recovery, the lack of forest cover on the island and the presence of urban areas. Twining and co-authors suggest that grey squirrels will persist in the latter as results show pine marten are forest specialists and avoid urban areas.

Although the red squirrel population is increasing in Northern Ireland, the researchers warn that "unless the issue of control within populated areas is addressed, we risk creating a situation where marten-savvy grey squirrels could recolonise the wider landscape in the future".

Consequently, as the pine marten "does not occupy urban areas anywhere within its European range, it is not likely to be the sole solution to the invasive grey squirrel" said Twining.

If pine marten are to extend their positive impact on red squirrels, issues impeding pine marten recovery need to be addressed. At present, Ireland and Britain are among the least forested countries in Europe with only 11% and 13% of forest cover respectively. The pine martens' sphere of influence is limited to its forested havens. Increasing forest cover, would lead to concurrent increases in the pine marten's ability to control grey squirrels and aid in recovery of the red squirrels.

Recovery of the pine marten could be further compounded by the potential of illegal persecution by a human population not used to its presence. Conflict could occur when pine martens predate on poultry or den in attics for example. Pine martens are still at the early stages of recovery, and human persecution remains the greatest threat to the species.

The researchers used presence-absence data to calculate the likelihood of a species occurring in a location. To collect the data, citizen scientists deployed a camera trap at sites with a minimum of 5 ha forest cover for one week at randomly selected locations. The study used data from 332 sites across Northern Ireland covering all sizes and shapes of woodlands from inner city Belfast to the Mournes, from the Glens of Antrim in the north to the Ring of Gullion in the south.

Multi-species models were used to estimate the probability of occupancy of arboreal mammals including the grey squirrels, red squirrels and pine martens throughout Northern Ireland. These models consider the effects of the interactions between species and their habitats. They combine information on the occurrence of an animal from the camera trap records with local habitat and environmental data accounting for imperfect detection.

HANOVER, N.H. - December 11, 2019 - Tropical glaciers in Africa and South America began their retreat simultaneously at the end of the last ice age about 20,000 years ago, according to a Dartmouth study.

The finding of synchrony in ice retreat across the global tropics clarifies how the low latitudes transformed during one of Earth's most extreme climate change events and can help current-day predictions of our own climate future.

The study, published in Science Advances, supports the overwhelming scientific consensus on the role of carbon dioxide in causing global climate change, but adds additional levels of complexity to the understanding of Earth's climate system and how ice ages rapidly end. The result also adds to the understanding of the sequencing of glacial retreat between the tropics and the polar regions at the time

"Carbon dioxide is what caused the Earth to come out of the last ice age," said Meredith Kelly, an associate professor in the Department of Earth Sciences at Dartmouth, and senior researcher on the study. "But there are also processes that began before carbon dioxide increased that are important to the overall story of how the period ended, and that's what we wanted to understand."

According to the Dartmouth study, glaciers in tropical Africa and South America reached their maximum extents about 29,000-21,000 years ago and then began to melt. This retreat is earlier than the significant rise in atmospheric carbon dioxide recorded at about 18,200 years ago.

The findings demonstrate a trend of increasing tropical temperatures across the planet and suggest that the warming may have been caused by a reduction in the temperature differences between the Earth's polar regions and the tropics.

At the end of the last ice age in the Arctic, small changes in Earth's orbit resulted in more solar radiation and warmer temperatures, and caused a retreat of the northern ice sheets. In Antarctica, the change of the planet's angle to the sun created longer summers. The reduction in the temperature gradient between the poles and the tropics slowed the movement of heat out of the low latitudes to the extreme north and south, making the tropics warmer and resulting in faster loss of glaciers in the region.

Once changes in ocean and atmospheric circulation patterns and the upsurge in carbon dioxide took over, the planet was left in an overwhelming warming spiral that melted ice sheets near the poles and all but eliminated glaciers in the tropics.

"Just a couple of thousand years could make all the difference in our understanding of past and present climate change events," said Margaret Jackson, who served as the lead author of the study while a PhD student at Dartmouth. "This study shows that glaciers were responding to warming even before the deglacial rise in carbon dioxide pushed the planet over the edge to end the last ice age."

In addition to a simultaneous, pan-tropical warming, the study's additional finding that tropical glaciers reached their maximum extents at the same time as glaciers at higher latitudes confirms a global synchrony of cooling during the last ice age.

Field research for the study was conducted on glacial moraines in the equatorial Rwenzori Mountains located on the border between Uganda and the Democratic Republic of Congo. Mountain glaciers, particularly those located at high elevations in tropical regions, are sensitive to changes in temperature. The study used the past extents of tropical glaciers to infer past changes in tropical temperatures.

Researchers determined the timing of tropical glacier advance and retreat by analyzing beryllium-10, a radioactive isotope that is produced in quartz. Since beryllium-10 is only made when a rock surface is exposed to the atmosphere, its concentration indicates the amount of time since a glacial moraine was deposited.

Prior research using beryllium-10 dating indicated that some tropical glaciers achieved their maximum extents during the height of the last ice age. But those findings were limited to South America. The Dartmouth study recalculated the previously-determined data taken from sites across tropical South America and extended the findings to tropical East Africa to demonstrate that glacier loss during this period was a pan-tropical phenomenon.

"We knew from past work that tropical glaciers in South America may have retreated early, but we didn't know how widespread the phenomenon was. The Rwenzori Mountains proved to be the perfect outdoor laboratory to confirm the pan-tropical timing of past climate change," said Jackson.

While ice core records from the tropics are available to researchers, interpreting information about past climate from them can be complex. Since the tropics are far from the direct cooling of high latitude ice sheets, the region can be used to better understand global temperatures during the last glacial period and help provide clues about how Earth's temperature changed over time.

The study also helps researchers understand how temperature gradients, greenhouse gasses, atmospheric circulation and ocean circulation work together to cause the planet to "flip" between cold and warm periods.

"Today's planet is entering a new climate mode that is unprecedented in the last millions of years," said Kelly. "Models of past change events can help us predict the future, and our more complete understanding of the tropics serves as an important piece of puzzle."

Existing research on tropical glaciers during the last ice age is constrained to Africa and South America. Future work aims to determine whether sites in other regions can add to the understanding of global climate change.

A research team has identified a new species of virus specific to insects that can be engineered to house genes from related viruses that cause diseases such as Zika and yellow fever. By serving as a platform for recombinant approaches, the new virus represents a flexible and non-infectious research tool for testing diagnostics and vaccines for various infectious diseases. Flaviviruses are a family of insect-transmitted viruses that can cause dangerous infections such as yellow fever, dengue and West Nile encephalitis. Although these viruses represent a major health burden worldwide, the development of new diagnostics and vaccines has been hampered because they require using infectious strains that pose a danger to people. In this study, Jody Hobson-Peters and colleagues detail a new species of flavivirus named Binjari virus that only infects insects, which they discovered after sequencing extracts from mosquitoes in Australia. After evaluating its genetic structure, the researchers found they could swap some of the virus's genes with genes from disease-causing flaviviruses. They engineered chimera Binjari virus particles that contained genes from Zika or West Nile virus, and observed the particles rapidly reproduced in mosquito cells but could not infect vertebrate cells. The Binjari chimeras could be used for various applications: a vaccine based on Binjari-Zika particles protected mice from Zika virus infection, and other chimeras could replace infectious flaviviruses in several assays that test for dengue or West Nile virus. The high replication rate and non-infectious nature of Binjari virus indicates it could be easily manufactured and modified for various medical applications without posing a risk to human health.

Berkeley -- If you use a vacuum-insulated thermos to help keep your coffee hot, you may know it's a good insulator because heat energy has a hard time moving through empty space. Vibrations of atoms or molecules, which carry thermal energy, simply can't travel if there are no atoms or molecules around.

But a new study by researchers at the University of California, Berkeley, shows how the weirdness of quantum mechanics can turn even this basic tenet of classical physics on its head.

The study, appearing this week in the journal Nature, shows that heat energy can leap across a few hundred nanometers of a complete vacuum, thanks to a quantum mechanical phenomenon called the Casimir interaction.

Though this interaction is only significant on very short length scales, it could have profound implications for the design of computer chips and other nanoscale electronic components where heat dissipation is key. It also upends what many of us learned about heat transfer in high school physics.

"Heat is usually conducted in a solid through the vibrations of atoms or molecules, or so-called phonons -- but in a vacuum, there is no physical medium. So, for many years, textbooks told us that phonons cannot travel through a vacuum," said Xiang Zhang, the professor of mechanical engineering at UC Berkeley who guided the study. "What we discovered, surprisingly, is that phonons can indeed be transferred across a vacuum by invisible quantum fluctuations."

In the experiment, Zhang's team placed two gold-coated silicon nitride membranes a few hundred nanometers apart inside a vacuum chamber. When they heated up one of the membranes, the other warmed up, too -- even though there was nothing connecting the two membranes and negligible light energy passing between them.

"This discovery of a new mechanism of heat transfer opens up unprecedented opportunities for thermal management at the nanoscale, which is important for high-speed computation and data storage," said Hao-Kun Li, a former Ph.D. student in Zhang's group and co-first author of the study. "Now, we can engineer the quantum vacuum to extract heat in integrated circuits."

No such thing as empty space

The seemingly impossible feat of moving molecular vibrations across a vacuum can be accomplished because, according to quantum mechanics, there is no such thing as truly empty space, said King Yan Fong, a former postdoctoral scholar at UC Berkeley and the study's other first author.

"Even if you have empty space -- no matter, no light -- quantum mechanics says it cannot be truly empty. There are still some quantum field fluctuations in a vacuum," Fong said. "These fluctuations give rise to a force that connects two objects, which is called the Casimir interaction. So, when one object heats up and starts shaking and oscillating, that motion can actually be transmitted to the other object across the vacuum because of these quantum fluctuations."

Though theorists have long speculated that the Casimir interaction could help molecular vibrations travel through empty space, proving it experimentally has been a major challenge. To do so, the team engineered extremely thin silicon nitride membranes, which they fabricated in a dust-free clean room, and then devised a way to precisely control and monitor their temperature.

They found that, by carefully selecting the size and design of the membranes, they could transfer the heat energy over a few hundred nanometers of vacuum. This distance was far enough that other possible modes of heat transfer were negligible -- such as energy carried by electromagnetic radiation, which is how energy from the sun heats up Earth.

Because molecular vibrations are also the basis of the sounds that we hear, this discovery hints that sounds can also travel through a vacuum, Zhang said.

"Twenty-five years ago, during my Ph.D. qualifying exam at Berkeley, one professor asked me 'Why can you hear my voice across this table?' I answered that, 'It is because your sound travels by vibrating molecules in the air.' He further asked, 'What if we suck all air molecules out of this room? Can you still hear me?' I said, 'No, because there is no medium to vibrate,'" Zhang said. "Today, what we discovered is a surprising new mode of heat conduction across a vacuum without a medium, which is achieved by the intriguing quantum vacuum fluctuations. So, I was wrong in my 1994 exam. Now, you can shout through a vacuum."

A new technology to produce safer 'hybrid' viruses at high volumes for use in vaccines and diagnostics for mosquito-borne diseases has been developed at The University of Queensland.

Researchers from UQ and QIMR Berghofer Medical Research Institute have exploited the benign characteristics of the Binjari virus - inert to humans - to produce 'dangerous looking' mosquito-borne viruses such as Zika and dengue, but which cannot grow in humans or animals.

School of Chemistry and Molecular Biosciences' Dr Jody Hobson-Peters said the team, led by Professor Roy Hall, began to explore this possibility after discovering new viruses in the lab.

"We were originally hoping to gain insights into how mosquito-borne viral diseases evolve - viruses like Zika, yellow fever and dengue," Dr Hobson-Peters said.

"We were also hoping to discover new viruses that might be useful for biotechnology or as biological control agents.

"The Binjari virus stood out, and while it grows to very high levels in mosquito cells in the lab, it's completely harmless and cannot infect humans or other vertebrate species.

"And it is incredibly tolerant for genetic manipulation, allowing us to swap important genes from pathogenic viruses like Zika, West Nile and dengue into the Binjari genome.

"This produces hybrid, or chimeric, viruses that physically appeared identical to the disease-causing viruses under the electron microscope, but were still unable to grow in human or animal cells."

The researchers have effectively developed a new biotechnology platform requiring low biocontainment, to help safely develop vaccines and diagnostics against these mosquito-borne diseases.

Professor Andreas Suhrbier, from QIMR Berghofer Medical Research Institute, said the team hoped to push this technology further down the development pathway toward human applications.

"The main advantage of this system is that it is safe," Professor Suhrbier said.

"These hybrids cannot infect humans, meaning that manufacture of vaccines and diagnostic reagents don't require the strict and expensive biosecurity infrastructure ordinarily needed to grow these pathogenic viruses.

"The research is a testament to collaborative science - this all fell into place, with amazing collaboration within the Australian Infectious Diseases Research Centre.

"It's a technology that will truly revolutionise the manufacture of vaccines - supercharging high-volume vaccine development."