Earth

NASA's Aqua satellite found that wind shear was tearing at Tropical Storm 07A in the Arabian Sea.

NASA's Aqua satellite used infrared light to analyze the strength of storms in 07A. Infrared data provides temperature information, and the strongest thunderstorms that reach high into the atmosphere have the coldest cloud top temperatures. On Dec. 4 at 3:20 a.m. EST (0820 UTC), the Moderate Resolution Imaging Spectroradiometer or MODIS instrument aboard NASA's Aqua satellite gathered temperature information about Tropical Storm 07A's cloud tops. MODIS found three small areas of powerful thunderstorms where temperatures were as cold as or colder than minus 70 degrees Fahrenheit (minus 56.6 Celsius). Cloud top temperatures that cold indicate strong storms with the potential to generate heavy rainfall.

Cloud tops surrounding those small areas were warmer, indicating those storms were weaker. The bulk of thunderstorms in 07A were warmer than minus 70 degrees Fahrenheit and they were being pushed to the east from westerly wind shear.

In general, wind shear is a measure of how the speed and direction of winds change with altitude. Tropical cyclones are like rotating cylinders of winds. Each level needs to be stacked on top each other vertically in order for the storm to maintain strength or intensify. Wind shear occurs when winds at different levels of the atmosphere push against the rotating cylinder of winds, weakening the rotation by pushing it apart at different levels. Winds from the west were displacing the bulk of clouds and showers from 07A and pushing them to the east.

On Dec. 4 at 4 a.m., EST (0900 UTC), Tropical Storm 07A was located near latitude 14.9 degrees north and longitude 68.7 degrees east in the Arabian Sea, Northern Indian Ocean. That is about 616 nautical miles south of Karachi, Pakistan. 07A was moving to the northwest and had maximum sustained winds near 45 knots.

Tropical Storm 07A is expected to weaken to a depression by Dec. 5 and then dissipate.

Typhoons and hurricanes are the most powerful weather event on Earth. NASA's expertise in space and scientific exploration contributes to essential services provided to the American people by other federal agencies, such as hurricane weather forecasting.

University of Canberra researchers have shown that art gallery programs can improve the wellbeing of people living with dementia - and they've backed it up by testing study participants' saliva.

Published in the Journal of Alzheimer's Disease, the UC study monitored new participants of the National Gallery of Australia's (NGA) Art and Dementia program over six weeks. The NGA program has been running for more than 12 years and has demonstrated anecdotal and observational benefits, now backed up by UC research.

Participants' saliva was tested to determine levels of cortisol - best-known as the main stress hormone - as it plays an important role in regulating mood, the cycle of sleep and wakefulness, and blood pressure, among others. The study is the largest of its kind in the world to measure biomarkers.

Lead researcher and University of Canberra PhD candidate Nathan D'Cunha said that normal cortisol levels are usually high upon waking, then drop throughout the day and bottom out at bedtime. In people living with dementia, this rhythm is disrupted, resulting in increased frailty, agitation and decreased cognitive performance.

"The waking-to-evening salivary cortisol ratio improved after six weeks of attending the program, and returned to baseline levels at a later follow-up, indicating a more dynamic salivary cortisol rhythm in response to the intervention," Mr D'Cunha said.

Mr D'Cunha said that while research focusing on a cure for dementia was important, initiatives that improved the quality of life for those living with dementia were just as crucial, particularly around social engagement.

It was reported that post-program, self-reported depressive symptoms decreased, and working memory and verbal fluency improved.

"Six weeks after the study, we asked participants what they remembered of the visits, and almost 50 per cent were able to recall specific aspects of the program," he said. "92 per cent of those responded that they very much looked forward to the visits to the NGA."

"We believe our results are an important step towards a larger controlled trial which not only asks people living with dementia about their experiences of engaging in regular art discussion, but also seeks to understand their physiological responses using non-invasive methods."

The NGA Art and Dementia Program has been running since 2007, with program producer Adriane Boag at the helm. UC's research collaboration with the National Gallery into the physiological benefits of the program is expected to continue.

"This research points to the future and supports what arts professionals have known: that participating in a program at a gallery has positive effects on mental and physical wellbeing," Ms Boag said.

Mr D'Cunha's PhD scholarship was awarded by the Dementia Australia Research Foundation; he has also received funding from the Australian Association of Gerontology (AAG).

Mr D'Cunha will be presenting the findings of this study at the upcoming AAG National Conference and the Gerontological Society of America conference in Austin, Texas.

The Parker Solar Probe spacecraft, which has flown closer to the Sun than any mission before, has found new evidence of the origins of the solar wind.

NASA's Parker Solar Probe was launched in August 2018. Its first results are published today in a series of four papers in Nature, with Imperial College London scientists among those interpreting some of the key data to reveal how the solar wind is accelerated away from the surface of the Sun.

The solar wind is a stream of charged particles released by the Sun that fills our Solar System. It is responsible for the North and Southern lights, but can also cause disruption during violent episodes like solar flares and coronal mass ejections, knocking out power grids and satellites.

Now, an international team have shown that bursty 'spikes' of solar wind originate in holes in the Sun's outer atmosphere near its equator, and are accelerated by magnetic phenomena as they flow away into deep space and past the Earth.

The new research suggests that the spikes are generated by 'magnetic reconnection' near the Sun, a process that pulls on the tense lines of the Sun's magnetic field creates folds or 'switchbacks'. These events last only a couple of minutes but release lots of energy, accelerating the solar wind away in long tubes that are approximately the diameter of the Earth.

The finding builds on data from the HELIOS missions, launched in the 1970s, the previous record-holders for the closest approach to the Sun.

Professor Tim Horbury from Imperial's Department of Physics is a co-investigator on Parker Solar Probe's FIELDS instrument, which is led by the University of California, Berkeley. He said: "From HELIOS data we could see what might be 'spikes' of faster solar wind, and now we have been able to confirm their existence in striking detail with Parker Solar Probe.

"We usually think of the fast solar wind as very smooth, but Parker Solar Probe saw surprisingly slow wind with a large number of these little bursts and jets of plasma, creating long tubes of fast wind containing plasma with around twice the energy of the background solar wind."

Parker Solar Probe is studying the Sun's outer atmosphere, called the corona, directly flying through it to better understand the origins of the solar wind.

For the new study, Parker Solar Probe took data at a distance of 24 million kilometres from the Sun, inside the orbit of Mercury. It will fly successively closer to the Sun in the coming years, eventually reaching a distance of less than six million kilometres from its surface and far closer than the Earth's average distance of 150 million kilometres.

Scientists know the properties of the solar wind change as it travels from the Sun to the Earth, so studying the solar wind closer to its origin should reveal more about how it is created and evolves.

Parker Solar Probe will also be joined next year by Solar Orbiter, a European Space Agency mission with Imperial kit onboard.

Professor Horbury added: "Although Parker Solar Probe will get even more accurate measurements of the young solar wind at its closest approach, it's too close for telescopes, so it won't be able to see what features on the surface of the Sun may be creating the structures of the solar wind.

"This is where Solar Orbiter comes in. It will not go as close to the Sun, but will have sophisticated telescopes and instruments on board that will be able to see from a distance what might be causing phenomena Parker Solar probe is detecting up close, forming a fuller picture of what creates and accelerates the solar wind."

Other results from the first data include measurement of the speed the solar wind, which does not flow radially away from the Sun, but has a sideways speed of 15-25 times faster than predicted; and a 'snowplow' effect where charged particles bunch up before being accelerated by a coronal mass ejection event.

A new discovery from a team led by Massachusetts Eye and Ear researchers may bring scientists a step closer to developing treatments that regrow the missing cells that cause hearing loss.

In a new study, published online December 4, 2019, in Nature Communications, scientists report a new strategy to induce cell division in the mature inner ear. With this pathway, they were able to reprogram the inner ear's cells to proliferate and regenerate hair-cell-like cells in adult mice. This first-of-its-kind, proof of concept study may provide an approach to the regeneration of sensory hair cells and other important inner ear cell types in people with hearing loss.

"This paper is the first to show that, by reprogramming, mature mammalian inner ear cells can be induced to divide and become hair cells, which are needed for hearing," said senior study author Zheng-Yi Chen, DPhil, an Associate Scientist at the Eaton-Peabody Laboratories at Mass. Eye and Ear, and an Associate Professor of Otolaryngology-Head and Neck Surgery at Harvard Medical School. "These findings of renewed proliferation and hair cell generation in a fully mature inner ear lay the foundation for the application of reprogramming and hair cell regeneration."

Hearing loss is one of the most common forms of sensory deficits in people, affecting about 37 million Americans, according to federal statistics. Inner ear cells of humans and other mammals lack the capacity to divide or regenerate; therefore, damage to the inner ear, in particular to the hair cells, leads to permanent hearing loss. Hair cells are the specialized inner-ear cells responsible for the transduction of sound-evoked mechanical vibrations into electrical signals that are then relayed to the brain. A number of genetic and environmental factors, including overexposure to loud sounds and aging, destroys these key cells in the hearing system.

There are currently no pharmaceutical treatments available for hearing loss.

Reprogramming inner ear cells to divide using transcription factors

Hearing loss can be caused by the loss of different inner ear cell types. The ability for remaining cells to divide and repopulate the ear is one way to achieve hearing recovery.

Previous research has shown that, in the newborn mouse inner ear, cells can be induced to divide and regenerate hair cells after damage. However, in fully mature ears, the capacity for cell division is lost, and hair cell regeneration does not occur. In humans, even a newborn inner ear is fully mature. Thus, Dr. Chen and colleagues said that in order to develop new treatments for human hearing loss, "it is essential to demonstrate that cell division and hair cell regeneration can be achieved in a mature mammalian inner ear."

In the new study, Dr. Chen's laboratory used a reprogramming approach by activating two molecular signals, Myc and Notch, in the adult ear. They found that mature inner ear cells can be induced to divide. Importantly, some of the new cells developed characteristics of hair cells, including the presence of the transduction channels that carry out the mechanical to electrical conversion, and the ability to form connections with auditory neurons, ,both of which are essential to hearing.

"Our work revealed that reprogramming is achieved by re-activation of early inner ear developmental genes so that the mature inner ear regains neonatal properties, which enables them to re-divide and regenerate," Dr. Chen explained.

Future research looks toward targets for pharmaceutical treatments

This work builds on earlier studies identifying the role of Notch in hair cell proliferation. "The most significant aspect of the current study is the fact that fully mature mammalian inner ear still retains the capacity to divide and regenerate if it is sufficiently reprogrammed, which removes a fundamental barrier that has prevented the inner ear regeneration necessary for hearing restoration," Dr. Chen further elaborated.

Dr. Chen's laboratory is working to discover additional drug-like molecules to achieve cell division and hair cell regeneration in the mature inner ear and in large animal models, including pigs.

"We hope that our research can serve as a model for regeneration of other tissues with similar properties that are unable to regrow cells, such as in the retina and the central nervous system," he added.

For years, researchers looking at seafloor sediments would find bits of black carbon along with organic carbon strewn across the ocean floor, but they couldn't say exactly where it originated. The challenge with studying deep marine carbon is that it is a mixture of fresh material delivered from the surface and an aged component, the origin of which had been previously unknown.

Now, a new University of Delaware study recently published in Nature Communications shows for the first time that the old carbon found on the seafloor can be directly linked to submicron graphite particles emanating from hydrothermal vents.

Identifying the sources, transport pathways and the fate of this seafloor carbon is key to understanding the dynamics of the marine carbon cycle.

The ocean acts as a reservoir for substantial amounts of both organic carbon and carbon dioxide, which can lead to ocean acidification or be converted to form organic carbon via photosynthesis. Thus, it is important to understand how carbon moves between different phases in the ocean and how it might become sequestered in the deep ocean for extremely long periods of time. This work shows that organic carbon and carbon dioxide can also be converted at vents to another form of carbon, graphite.

The study was led by Emily Estes, a former post-doctoral researcher at UD who is now a staff scientist with the International Ocean Discovery Program at Texas A&M University, and George Luther, the Maxwell P. and Mildred H. Harrington Professor of Marine Chemistry and the Francis Alison Professor in UD's College of Earth, Ocean and Environment (CEOE).

To conduct their study, the researchers used samples of nanoparticles from five different hydrothermal vent sites collected during a research expedition to the East Pacific Rise vent field in the Pacific Ocean in 2017, funded by the National Science Foundation's marine geology and geophysics program.

Estes conducted shipboard sampling of hydrothermal vent fluids and particulates during the expedition, which was led by Luther.

When they got back from the research cruise and wanted to take a deeper look at what they collected, the samples were analyzed under scanning and transmission microscopes by colleagues at the National Center for Earth and Environmental Nanotechnology Infrastructure (NanoEarth) at Virginia Tech.

Once they looked at the results, Estes noticed a large number of submicron graphite particles, similar to what would be found in an everyday lead pencil, in the samples.

While it's known that graphite can form hydrothermally in sediments, this study showed that these sub-micron particles of graphite that come out of the vents occur consistently across a range of vent environments, including both focused high temperature and low temperature venting sites.

"Even though our study is a preliminary observation of these particles, it suggests that they're probably very widespread and could be a significant source of this type of carbon to the deep ocean," said Estes.

Overlooked graphite

Previous studies may have overlooked the significance of graphite particles because of the way in which dissolved organic carbon and particulate organic carbon are measured.

Working with Andrew Wozniak, assistant professor in the School of Marine Science and Policy in CEOE, and Nicole Coffey, a master's level student in CEOE who was also on the research cruise as an undergraduate in 2017, Estes and Luther were able to show that common techniques used to measure dissolved organic carbon or particulate organic carbon also pick up graphite.

Because graphite is only made up of carbon, however, if somebody just did a generic carbon-14 measurement, they might overlook that there's hydrothermal graphite in their sample.

"Graphite is not carbon with hydrogen, oxygen, nitrogen and other elements," said Luther. "So here's an inorganic form of carbon, because it's pure carbon, that's also being measured as organic carbon, whether it's dissolved or particulate."

Finding these submicron graphite particles helps to answer a mystery that has confounded researchers with regards to dissolved organic carbon in really deep ocean environments.

"If you measure the carbon-14 age on it, it comes out to be a little bit older than you would actually expect and so there's been a mystery surrounding what the source of this old organic carbon is," said Estes. "We showed that vents emit this graphitic carbon."

Another important point of the paper is that because these graphite submicron particles are not dense and emit from the hydrothermal vents in flat sheet-like structures, they have the potential to get entrained into ocean currents and distributed far away from the vent sites. This will be important to take into consideration for future research in regards to the marine carbon cycle.

"The next steps will be trying to actually quantify how much carbon is coming out of the vents and then compare that to what we measure as dissolved organic carbon in the ocean and figure out what part of the flux it is," said Estes.

WASHINGTON -- For the first time, researchers have used a chip-based sensor with an integrated laser to detect very low levels of a cancer protein biomarker in a urine sample. The new technology is more sensitive than other designs and could lead to non-invasive and inexpensive ways to detect molecules that indicate the presence or progression of a disease.

"Current methods to measure biomarker levels are expensive and sophisticated, requiring biopsies and analysis in specialized laboratories," said research team leader Sonia M. Garcia-Blanco from the University of Twente in the Netherlands. "The new technology we developed paves the way to faster and ultra-sensitive detection of panels of biomarkers that will permit doctors to make timely decisions that improve personalized diagnosis and treatment of medical conditions including cancer."

In The Optical Society (OSA) journal Optics Letters, a multi-institutional group of researchers funded by the H2020 European project GLAM (Glass multiplexed biosensor), shows that the new sensor can perform label-free detection of S100A4, a protein associated with human tumor development, at levels that are clinically relevant.

"The biosensor could enable point-of-care devices that simultaneously screen for various diseases," said Garcia-Blanco. "Its operation is simple and does not require complicated sample treatments or sensor operation, making it an excellent candidate for clinical applications."

The researchers say that the sensor holds potential for non-biomedical applications, as well. For example, it can also be used to detect different types of gases or liquid mixtures.

Creating a high-sensitivity sensor

The new chip-based sensor detects the presence of specific molecules by illuminating the sample with light from an on-chip microdisk laser. When the light interacts with the biomarker of interest the color, or frequency, of this laser light shifts in a detectable way.

To perform detection in urine samples, the researchers had to figure out how to integrate a laser that could operate in a liquid environment. They turned to the photonic material aluminum oxide, because when doped with ytterbium ions it can be used to fabricate a laser that emits in a wavelength range outside the light absorption band of water while still enabling the precise detection of the biomarkers.

"Although sensors based on monitoring frequency shifts of lasers already exist, they often come in geometries that are not easily integrated on small, disposable photonic chips," said Garcia-Blanco. "Aluminum oxide can easily be fabricated monolithically on-chip and is compatible with standard electronic fabrication procedures. This means that the sensors can be produced on a large, industrial scale."

Using a microdisk laser rather than the non-lasing ring resonators used in other similar sensors opens the door to unprecedented sensitivity. The sensitivity comes from the fact that the lasing linewidth is much narrower than the resonances of passive ring resonators. Once other noise sources, such as thermal noise, are eliminated, this method will allow the detection of very small frequency shifts from biomarkers at very low concentrations.

Detecting minute biomarker concentrations

After developing and applying a surface treatment that captures the biomarkers of interest in complex liquids such as urine, the researchers tested the new sensor with synthetic urine containing known biomarker levels. They were able to detect S100A4 at concentrations as low as 300 picomolar.

"Detection in this concentration range shows the potential of the platform for label-free biosensing," said Garcia-Blanco. "Furthermore, the detection module can be potentially made very simple using the developed technology, bringing it a step closer to the final application outside of the laboratory."

The researchers are working to incorporate all the relevant optical sources and signal generation components onto the chip to make the device even simpler to operate. They also want to develop various coatings that could allow parallel detection of a large variety of biomarkers.

In August 2018, NASA's Parker Solar Probe launched to space, soon becoming the closest-ever spacecraft to the Sun. With cutting-edge scientific instruments to measure the environment around the spacecraft, Parker Solar Probe has completed three of 24 planned passes through never-before-explored parts of the Sun's atmosphere, the corona. On Dec. 4, 2019, four new papers in the journal Nature describe what scientists have learned from this unprecedented exploration of our star -- and what they look forward to learning next.

These findings reveal new information about the behavior of the material and particles that speed away from the Sun, bringing scientists closer to answering fundamental questions about the physics of our star. In the quest to protect astronauts and technology in space, the information Parker has uncovered about how the Sun constantly ejects material and energy will help scientists re-write the models we use to understand and predict the space weather around our planet and understand the process by which stars are created and evolve.

"This first data from Parker reveals our star, the Sun, in new and surprising ways," said Thomas Zurbuchen, associate administrator for science at NASA Headquarters in Washington. "Observing the Sun up close rather than from a much greater distance is giving us an unprecedented view into important solar phenomena and how they affect us on Earth, and gives us new insights relevant to the understanding of active stars across galaxies. It's just the beginning of an incredibly exciting time for heliophysics with Parker at the vanguard of new discoveries."

Though it may seem placid to us here on Earth, the Sun is anything but quiet. Our star is magnetically active, unleashing powerful bursts of light, deluges of particles moving near the speed of light and billion-ton clouds of magnetized material. All this activity affects our planet, injecting damaging particles into the space where our satellites and astronauts fly, disrupting communications and navigation signals, and even -- when intense -- triggering power outages. It's been happening for the Sun's entire 5-billion-year lifetime, and will continue to shape the destinies of Earth and the other planets in our solar system into the future.

"The Sun has fascinated humanity for our entire existence," said Nour E. Raouafi, project scientist for Parker Solar Probe at the Johns Hopkins Applied Physics Laboratory in Laurel, Maryland, which built and manages the mission for NASA. "We've learned a great deal about our star in the past several decades, but we really needed a mission like Parker Solar Probe to go into the Sun's atmosphere. It's only there that we can really learn the details of these complex solar processes. And what we've learned in just these three solar orbits alone has changed a lot of what we know about the Sun."

What happens on the Sun is critical to understanding how it shapes the space around us. Most of the material that escapes the Sun is part of the solar wind, a continual outflow of solar material that bathes the entire solar system. This ionized gas, called plasma, carries with it the Sun's magnetic field, stretching it out through the solar system in a giant bubble that spans more than 10 billion miles.

The dynamic solar wind

Observed near Earth, the solar wind is a relatively uniform flow of plasma, with occasional turbulent tumbles. But by that point it's traveled over ninety million miles -- and the signatures of the Sun's exact mechanisms for heating and accelerating the solar wind are wiped out. Closer to the solar wind's source, Parker Solar Probe saw a much different picture: a complicated, active system.

"The complexity was mind-blowing when we first started looking at the data," said Stuart Bale, the University of California, Berkeley, lead for Parker Solar Probe's FIELDS instrument suite, which studies the scale and shape of electric and magnetic fields. "Now, I've gotten used to it. But when I show colleagues for the first time, they're just blown away." From Parker's vantage point 15 million miles from the Sun, Bale explained, the solar wind is much more impulsive and unstable than what we see near Earth.

Like the Sun itself, the solar wind is made up of plasma, where negatively charged electrons have separated from positively charged ions, creating a sea of free-floating particles with individual electric charge. These free-floating particles mean plasma carries electric and magnetic fields, and changes in the plasma often make marks on those fields. The FIELDS instruments surveyed the state of the solar wind by measuring and carefully analyzing how the electric and magnetic fields around the spacecraft changed over time, along with measuring waves in the nearby plasma.

These measurements showed quick reversals in the magnetic field and sudden, faster-moving jets of material -- all characteristics that make the solar wind more turbulent. These details are key to understanding how the wind disperses energy as it flows away from the Sun and throughout the solar system.

One type of event in particular drew the eye of the science teams: flips in the direction of the magnetic field, which flows out from the Sun, embedded in the solar wind. These reversals -- dubbed "switchbacks" -- last anywhere from a few seconds to several minutes as they flow over Parker Solar Probe. During a switchback, the magnetic field whips back on itself until it is pointed almost directly back at the Sun. Together, FIELDS and SWEAP, the solar wind instrument suite led by the University of Michigan and managed by the Smithsonian Astrophysical Observatory, measured clusters of switchbacks throughout Parker Solar Probe's first two flybys.

"Waves have been seen in the solar wind from the start of the space age, and we assumed that closer to the Sun the waves would get stronger, but we were not expecting to see them organize into these coherent structured velocity spikes," said Justin Kasper, principal investigator for SWEAP -- short for Solar Wind Electrons Alphas and Protons -- at the University of Michigan in Ann Arbor. "We are detecting remnants of structures from the Sun being hurled into space and violently changing the organization of the flows and magnetic field. This will dramatically change our theories for how the corona and solar wind are being heated."

The exact source of the switchbacks isn't yet understood, but Parker Solar Probe's measurements have allowed scientists to narrow down the possibilities.

Among the many particles that perpetually stream from the Sun are a constant beam of fast-moving electrons, which ride along the Sun's magnetic field lines out into the solar system. These electrons always flow strictly along the shape of the field lines moving out from the Sun, regardless of whether the north pole of the magnetic field in that particular region is pointing towards or away from the Sun. But Parker Solar Probe measured this flow of electrons going in the opposite direction, flipping back towards the Sun -- showing that the magnetic field itself must be bending back towards the Sun, rather than Parker Solar Probe merely encountering a different magnetic field line from the Sun that points in the opposite direction. This suggests that the switchbacks are kinks in the magnetic field -- localized disturbances traveling away from the Sun, rather than a change in the magnetic field as it emerges from the Sun.

Parker Solar Probe's observations of the switchbacks suggest that these events will grow even more common as the spacecraft gets closer to the Sun. The mission's next solar encounter on Jan. 29, 2020, will carry the spacecraft nearer to the Sun than ever before, and may shed new light on this process. Not only does such information help change our understanding of what causes the solar wind and space weather around us, it also helps us understand a fundamental process of how stars work and how they release energy into their environment.

The rotating solar wind

Some of Parker Solar Probe's measurements are bringing scientists closer to answers to decades-old questions. One such question is about how, exactly, the solar wind flows out from the Sun.

Near Earth, we see the solar wind flowing almost radially -- meaning it's streaming directly from the Sun, straight out in all directions. But the Sun rotates as it releases the solar wind; before it breaks free, the solar wind was spinning along with it. This is a bit like children riding on a playground park carousel - the atmosphere rotates with the Sun much like the outer part of the carousel rotates, but the farther you go from the center, the faster you are moving in space. A child on the edge might jump off and would, at that point, move in a straight line outward, rather than continue rotating. In a similar way, there's some point between the Sun and Earth, the solar wind transitions from rotating along with the Sun to flowing directly outwards, or radially, like we see from Earth.

Exactly where the solar wind transitions from a rotational flow to a perfectly radial flow has implications for how the Sun sheds energy. Finding that point may help us better understand the lifecycle of other stars or the formation of protoplanetary disks, the dense disks of gas and dust around young stars that eventually coalesce into planets.

Now, for the first time -- rather than just seeing that straight flow that we see near Earth -- Parker Solar Probe was able to observe the solar wind while it was still rotating. It's as if Parker Solar Probe got a view of the whirling carousel directly for the first time, not just the children jumping off it. Parker Solar Probe's solar wind instrument detected rotation starting more than 20 million miles from the Sun, and as Parker approached its perihelion point, the speed of the rotation increased. The strength of the circulation was stronger than many scientists had predicted, but it also transitioned more quickly than predicted to an outward flow, which is what helps mask these effects from where we usually sit, about 93 million miles from the Sun.

"The large rotational flow of the solar wind seen during the first encounters has been a real surprise," said Kasper. "While we hoped to eventually see rotational motion closer to the Sun, the high speeds we are seeing in these first encounters is nearly ten times larger than predicted by the standard models."

Dust near the Sun

Another question approaching an answer is the elusive dust-free zone. Our solar system is awash in dust -- the cosmic crumbs of collisions that formed planets, asteroids, comets and other celestial bodies billions of years ago. Scientists have long suspected that, close to the Sun, this dust would be heated to high temperatures by powerful sunlight, turning it into a gas and creating a dust-free region around the Sun. But no one had ever observed it.

For the first time, Parker Solar Probe's imagers saw the cosmic dust begin to thin out. Because WISPR -- Parker Solar Probe's imaging instrument, led by the Naval Research Lab -- looks out the side of the spacecraft, it can see wide swaths of the corona and solar wind, including regions closer to the Sun. These images show dust starting to thin a little over 7 million miles from the Sun, and this decrease in dust continues steadily to the current limits of WISPR's measurements at a little over 4 million miles from the Sun.

"This dust-free zone was predicted decades ago, but has never been seen before," said Russ Howard, principal investigator for the WISPR suite -- short for Wide-field Imager for Solar Probe -- at the Naval Research Laboratory in Washington, D.C. "We are now seeing what's happening to the dust near the Sun."

At the rate of thinning, scientists expect to see a truly dust-free zone starting a little more than 2-3 million miles from the Sun -- meaning Parker Solar Probe could observe the dust-free zone as early as 2020, when its sixth flyby of the Sun will carry it closer to our star than ever before.

Putting space weather under a microscope

Parker Solar Probe's measurements have given us a new perspective on two types of space weather events: energetic particle storms and coronal mass ejections.

Tiny particles -- both electrons and ions -- are accelerated by solar activity, creating storms of energetic particles. Events on the Sun can send these particles rocketing out into the solar system at nearly the speed of light, meaning they reach Earth in under half an hour and can impact other worlds on similarly short time scales. These particles carry a lot of energy, so they can damage spacecraft electronics and even endanger astronauts, especially those in deep space, outside the protection of Earth's magnetic field -- and the short warning time for such particles makes them difficult to avoid.

Understanding exactly how these particles are accelerated to such high speeds is crucial. But even though they zip to Earth in as little as a few minutes, that's still enough time for the particles to lose the signatures of the processes that accelerated them in the first place. By whipping around the Sun at just a few million miles away, Parker Solar Probe can measure these particles just after they've left the Sun, shedding new light on how they are released.

Already, Parker Solar Probe's IS?IS instruments, led by Princeton University, have measured several never-before-seen energetic particle events -- events so small that all trace of them is lost before they reach Earth or any of our near-Earth satellites. These instruments have also measured a rare type of particle burst with a particularly high number of heavier elements -- suggesting that both types of events may be more common than scientists previously thought.

"It's amazing - even at solar minimum conditions, the Sun produces many more tiny energetic particle events than we ever thought," said David McComas, principal investigator for the Integrated Science Investigation of the Sun suite, or IS?IS, at Princeton University in New Jersey. "These measurements will help us unravel the sources, acceleration, and transport of solar energetic particles and ultimately better protect satellites and astronauts in the future."

Data from the WISPR instruments also provided unprecedented detail on structures in the corona and solar wind -- including coronal mass ejections, billion-ton clouds of solar material that the Sun sends hurtling out into the solar system. CMEs can trigger a range of effects on Earth and other worlds, from sparking auroras to inducing electric currents that can damage power grids and pipelines. WISPR's unique perspective, looking alongside such events as they travel away from the Sun, has already shed new light on the range of events our star can unleash.

"Since Parker Solar Probe was matching the Sun's rotation, we could watch the outflow of material for days and see the evolution of structures," said Howard. "Observations near Earth have made us think that fine structures in the corona segue into a smooth flow, and we're finding out that's not true. This will help us do better modeling of how events travel between the Sun and Earth."

As Parker Solar Probe continues on its journey, it will make 21 more close approaches to the Sun at progressively closer distances, culminating in three orbits a mere 3.83 million miles from the solar surface.

"The Sun is the only star we can examine this closely," said Nicola Fox, director of the Heliophysics Division at NASA Headquarters. "Getting data at the source is already revolutionizing our understanding of our own star and stars across the universe. Our little spacecraft is soldiering through brutal conditions to send home startling and exciting revelations."

Data from Parker Solar Probe's first two solar encounters is available to the public online.

Parker Solar Probe is part of NASA's Living with a Star program to explore aspects of the Sun-Earth system that directly affect life and society. The Living with a Star program is managed by the agency's Goddard Space Flight Center in Greenbelt, Maryland, for NASA's Science Mission Directorate in Washington. Johns Hopkins APL designed, built and operates the spacecraft.

Access to abundant, clean, water for drinking, recreation and the environment is one of the 21st century's most pressing issues. Directly monitoring threats to the quality of fresh water is critically important, but because current methods are costly and not standardized, comprehensive water quality datasets are rare. In the United States, one of the most data-rich countries in the world, fewer than 1% of all bodies of fresh water have ever been sampled for quality.

In a new paper, AquaSat: a dataset to enable remote sensing of water quality for inland waters, a team led by Colorado State University Assistant Professor Matt Ross matched large public datasets of water quality observations with satellite imagery to address the challenges of measuring water quality efficiently and cost-effectively.

Threats we can't fully understand - yet

According to Ross, a watershed scientist in the Department of Ecosystem Science and Sustainability, there are many threats to water quality, including nutrients from agricultural runoff that support algae blooms; sedimentation in reservoirs that cause distribution challenges; and dissolved carbon from decaying leaves that interrupts chemical reactions that keep water clean and safe for drinking.

For the most part, government entities monitor water quality in the U.S. by sending scientists into the field to measure variables like the amount of chlorophyll (from algae), concentrations of suspended sediment, dissolved organic carbon, and water clarity in person.

But, as Ross and his team explain, to fully understand and inventory changes in water quality, a far larger dataset is required; that in turn requires more and more people to do field sampling, which is very expensive and unlikely to completely address the problem.

Instead, the team suggests using remote sensing from satellite imagery could be a way to vastly expand our understanding of variation in water quality at continental scales, with little extra cost for sampling.

Merging satellite imagery with field measurements

For many decades, scientists have known that water's color tells us something about what is in it. Bright tan water likely indicates a river full of sediment. Green swirls over Lake Erie show algae growing and producing chlorophyll. Dark brown waters draining tannin-rich forests and swamps turn blue waters into a tea-colored brown because of how light interacts with certain dissolved organic carbon compounds.

Imaging satellites orbiting the earth, including Landsat, detect these color variations as they take images of the Earth every 16 days.

"These satellites have fundamentally changed how we understand long-term changes in agriculture, forests, fires, and other land cover changes," explained Ross. "However, there has been less use of the Landsat archive for understanding inland water quality changes."

One challenge of using Landsat images to evaluate water quality is the lack of a centralized dataset that pairs the satellite imagery with on-the-ground observations. These matchups - for example, when satellites snap a picture on the same day someone takes an algae sample - can be used to build algorithms that use imagery alone to predict water quality from space.

Fewer than 1,000 such matchups, mostly built for individual studies, currently exist, slowing researchers' ability to build, test, and apply large-scale models to predict water quality for every cloud-free image in the Landsat archive.

A 'symphony of data'

The CSU researchers built a novel dataset of more than 600,000 matchups between water quality field measurements and Landsat imagery, creating what Ross calls a "symphony of data."

The water quality data came from two public sources: the Water Quality Portal, a federal data clearinghouse from more than 400 different state, local, and federal agencies; and LAGOS-NE, an open-science dataset of lake water quality measurements for the Northeastern United States. Combined, these datasets provide more than 6 million water quality observations.

Using open-source software and Google Earth Engine, the authors merged the water quality data with the Landsat archive from 1984-2019. Both the raw datasets and the merged matchup dataset, which they call AquaSat, are now available along with the underlying code so future users can update, change, and improve it.

The authors expect that this dataset will unlock powerful new applications in remote sensing of water quality.

"We're hoping these tools will help build national-scale water quality estimates for large rivers and lakes," said Ross. "These data would dramatically improve our understanding of water quality change at the macro-scale and allow the remote sensing community to compare methods and collectively improve our approach."

In the future, Ross's team expects to go beyond the U.S. to employ these same methods to improve water quality monitoring in other places with little or no field observations.

PULLMAN, Wash. - Resembling an overgrown house cat with black-tipped ears and a stubby tail, the Canada lynx, a native of North America, teeters on the brink of extinction in the U.S. The few lynx that now roam parts of Washington and the mountainous Northwest survive largely because of a network of protected landscapes that crosses the U.S.-Canada border.

Washington State University environmental researchers believe this transboundary landscape provides not only essential habitat for the wild cats but likely also vital connections with larger lynx populations in Canada.

Wildlife cameras set by WSU researchers recently photographed lynx in the Kettle Mountains of far northeast Washington, close to the Canadian border, and more big cats have been spotted in Glacier National Park near the Montana-Canada line.

Lynx, like their forest-dwelling neighbor the grizzly bear, require many miles of connected, undeveloped terrain to survive. According to new research led by Daniel Thornton, assistant professor in WSU's School of the Environment, such terrain occurs most frequently throughout the Americas near international borders.

This clustering of protected habitats, including national parks and conservation areas, makes many iconic, wide-ranging animals--lynx, grizzlies, jaguars, tapirs and scarlet macaws among them--physically dependent on good relations between neighboring countries and wildlife-friendly borders.

"Because protected areas are more common near international boundaries, cooperation across borders will be key to maintaining large, connected, resilient protected areas for biodiversity conservation," Thornton said. "And because border regions are so important in this regard, anything that negatively impacts transboundary cooperation between countries or the ability of animals to move across borders--such as increased security and border structures--could be very problematic for species conservation."

Cross-border cooperation needed to mitigate climate change, other threats

In addition to politically charged border security measures, climate change and other large-scale landscape alterations pose serious threats to wildlife and habitat preservation throughout the Americas.

Writing in Ecological Applications, Thornton and his research collaborators at the University of Florida and Trent University in Ontario, Canada, said their study results indicate "efforts to conserve species and mitigate effects of long-term stressors, like climate change, will be most successful when planning includes neighboring countries."

The scientists examined the distribution, connectivity, and integrity of protected areas near the borders of 23 countries across North, South and Central America. They found clustering of these primary habitat areas extending approximately 78 miles from the borderlines.

Connectivity of protected areas is especially important for animals to be able to adjust to habitat loss and fragmentation or to shift their ranges as climate changes, the researchers said. Maintaining these landscape networks will grow increasingly critical where forest depletion is taking a toll.

For example, a cross-boundary approach to managing protected areas could be especially beneficial in the highly threatened Dry/Wet Chaco ecoregion bordering Argentina, Paraguay and Bolivia. Rapid deforestation there is dividing habitats, causing negative impacts on numerous species.

Although international conservation efforts are relatively rare in the Americas, transboundary protected areas are expanding globally, leading to more integrated and large-scale conservation projects among neighboring countries, the researchers said. They noted additional benefits from these projects include promoting climate change resilience, sustainable development across borders, cooperative resource management and peace.

A computational analysis has surfaced new insights into the wind and water conditions that cause Kemp's ridley sea turtles to become stranded on beaches in Cape Cod, Massachusetts. Xiaojian Liu of Wuhan University, China, and colleagues present these findings in the open-access journal PLOS ONE on December 4, 2019.

The Kemp's ridley sea turtle is smaller and in greater danger of extinction than any other sea turtle in the world. This species is found in coastal waters ranging from the Gulf of Mexico to Nova Scotia, Canada. While Kemp's ridley populations have slowly risen since conservation efforts began in the 1970s, the number of turtles found stranded on Cape Cod beaches in the last few years is nearly an order of magnitude higher than in earlier decades.

To help clarify the conditions that lead to stranding, Liu and colleagues combined computational modeling with real-world observations. This enabled them to investigate circumstances that could trigger hypothermia in Kemp's ridley turtles--the primary cause of most strandings--and subsequent transport of the cold-stunned animals to shore.

The researchers used the Finite Volume Community Ocean Model to simulate ocean currents in Cape Cod Bay. To validate these simulations, they also released drifting instruments into the currents and tracked their movements via satellite. Then, they looked for links between the simulations, the drifter data, water temperature data, and records of where and when Kemp's ridley turtles were found stranded.

The findings suggest that Kemp's ridley sea turtles are more likely to become stranded at certain beach locations along Cape Cod when water temperatures drop below 10.5° Celsius and, concurrently, winds blow with high wind stress in certain directions. Once stranded, hypothermic turtles usually require assistance from trained volunteers in order to survive.

While these findings provide new insights that could help guide future search and rescue efforts, questions remain. Further research is needed to clarify the depth of water at which Kemp's ridley sea turtles typically become hypothermic, and how processes like wind and waves may impact stranding events at those depths.

Co-author James Manning notes: "While the state-of-the-art ocean model can help simulate the process, both the student-built drifters and bottom temperature sensors deployed by local fishermen are critical to the investigation."

DURHAM, N.C. -- When most people think of a plant, they picture stems, leaves, flowers, and all the parts that are visible above ground. But Duke biologist Philip Benfey is more interested in the hidden half of the plant that is buried beneath the soil. Roots: they may be out of sight, Benfey says, but they play critical roles, anchoring the plant and taking up water and nutrients.

Now, Benfey and colleagues Masashi Yamada and Xinwei Han have pieced together new details in the cascade of events that guide root growth -- research that could lead to more productive crops optimized for different soil types.

As a root tunnels through the soil, stem cells in the root's tip must determine whether to divide and produce more of the same stem cells, or differentiate into other cell types, based on their location within the root tissue. In a study published in the journal Nature, the researchers show that cells get some of the information they need from substances that are usually thought to be harmful.

Natural byproducts of cellular respiration, molecules called "reactive oxygen species" have long been described as stress signals that can cause tissue damage if left unchecked. But they also play a role in cell signaling, Benfey's work shows.

In a study of the small flowering plant Arabidopsis thaliana, the researchers report that root growth is partly regulated by interactions between two types of reactive oxygen species, superoxide and hydrogen peroxide, as they build up in different regions of the root tip.

"What we did was map out, from signal to response, how these supposedly toxic chemicals are harnessed for a signaling process," Benfey said.

Roots grow longer thanks to a small region of stem cells at the end of each root that produces a constant supply of new cells behind it, propelling the root tip further downward through the soil like the head of a bullet. The daughter cells that are left behind stay put, and eventually stop dividing and start to specialize.

How fast a root grows depends on the balance between two opposing cues: those that encourage these stem cells to keep multiplying, and those that tell them to put the brakes on proliferating and change gears to specialize. The researchers identified a protein called RITF1 that, when activated, triggers this developmental switch.

The protein works by controlling where the two reactive oxygen species concentrate within the growing tip of the root.

These chemical signals tell the surrounding cells what course of action to take next. Cells exposed to higher amounts of superoxide keep dividing and producing new cells, while those that get a heavy dose of hydrogen peroxide differentiate, with a zone of transition where the two overlap.

"We don't have all the pieces yet," Benfey said, "but there are a lot more steps of the process that are now known through this work than were known before."

"Reactive oxygen species aren't just toxic chemicals," Benfey said. "They serve important roles as regulators of a developmental process, going from a stem cell to fully differentiated tissue."

ITHACA, N.Y. - A Cornell University senior has come up with a way to discern life on exoplanets loitering in other cosmic neighborhoods: a spectral field guide.

Zifan Lin has developed high-resolution spectral models and scenarios for two exoplanets that may harbor life: Proxima b, in the habitable zone of our nearest neighbor Proxima Centauri; and Trappist-1e, one of three possible Earth-like exoplanet candidates in the Trappist-1 system.

The paper, co-authored with Lisa Kaltenegger, associate professor of astronomy and director of Cornell's Carl Sagan Institute, published in Monthly Notices of the Royal Astronomical Society.

"In order to investigate whether there are signs of life on other worlds, it is very important to understand signs of life that show in a planet's light fingerprint," Lin said. "Life on exoplanets can produce a characteristic combination of molecules in its atmosphere - and those become telltale signs in the spectra of such planets.

"In the near future we will be seeing the atmosphere of these worlds with new, sophisticated ground-based telescopes, which will allow us to explore the exoplanet's climate and might spot its biota," he said.

In the search for habitable worlds, "M dwarf" stars catch astronomers' eyes, since the local universe teems with these suns, which make up 75% of the nearby cosmos, according to Lin.

Throughout the Milky Way, our home galaxy, astronomers have discovered more than 4,000 exoplanets, some in their own suns' habitable zone - an area that provides conditions suitable for life.

To explore the atmosphere of these places, scientists need large next-generation telescopes, such as the Extremely Large Telescope (ELT), which is currently under construction in northern Chile's Atacama Desert and expected to be operational in 2025. Scientists can aim the mammoth eyepiece - with a flawless primary mirror about half the size of a football field - at Proxima b and Trappist-1e. The future telescope will have more than 250 times the light-gathering power of the Hubble Space Telescope.

Lin and Kaltenegger said the high-resolution spectrographs from the ELT can discern water, methane and oxygen for both Proxima b and Trappist-1e, if these planets are like our own pale blue dot.

"Zifan has generated a database of light fingerprints for these worlds, a guide to allow observers to learn how to find signs of life, if they are there," Kaltenegger said. "We are providing a template on how to find life on these worlds, if it exists."

Coral reefs support 25 percent of all marine life around the globe. Those in the Gulf of Mexico, along the coasts of Louisiana, Florida, Texas and Mexico, might be less known and less popular among tourists than other reefs; nevertheless, they also serve as important barriers to storm surge, lessening the impact of dangerous hurricanes. In a new paper published in the journal Frontiers in Marine Science, LSU geography and anthropology professor Kristine DeLong and her team of researchers used coupled climate model simulations as well as studies of fossil corals to describe how climate change will impact reefs in the Gulf of Mexico in the not-so-distant future, including a realistic snapshot of years 2080-2100.

While researchers have done a lot of work on the Great Barrier Reef in Australia and in the Pacific and Caribbean reefs, DeLong and her team are among the first to produce climate projections specifically for the Gulf of Mexico.

In an effort to learn from history, DeLong studied fossil corals from the last interglacial period--between ice ages--when the Earth was 11 percent warmer in the northern hemisphere and there was a greater loss of Arctic sea ice, with sea levels up to six meters higher than they are today. About 120,000 years ago, DeLong and her co-authors found, coral reefs were able to adapt to a new and relatively extreme climate by, for example, moving geographically, i.e., toward the North and South Poles, as well as up or down in the water column to avoid warmer surface waters. The Florida Keys in the southeastern Gulf of Mexico actually had extensive coral reef coverage during the last interglacial period. This could seem promising in a scenario where sea surface temperatures are expected to go up at least 2 degrees Celsius or as much as 3.4 degrees Celsius by 2100 (about 0.37 degrees Celsius per decade), according to the team's projections. But not so fast, they say. The rise in temperature is happening much more rapidly today than in the distant past, leaving coral reefs little time to adapt. Also, due to the acidification of the oceans, including at depth, coral reefs are increasingly trapped between warmer surface waters and more acidic environments deeper in the water column. Further, there is no evidence of acclimatization to acidification, and moving north is out of the question for Gulf of Mexico coral reefs, as they'd end up on land.

"We are all very concerned about our coral reefs," DeLong said about herself and her collaborators at the University of Texas at Austin and Rice University in Houston, Tx. "We wanted to get the perspective of what happened in the past, how reefs have responded to changes in climate that are either natural or anthropogenic, meaning caused by humans. There has been substantial natural climate variability that it's important to look at because it tells us something about what we might expect in the next 100 years. It can help us answer many important questions."

By dating corals, going back even further with uranium-thorium dating than with radiocarbon dating, DeLong and her co-authors can observe paleoenvironmental changes in ancient coral skeletons.

"You see chemical changes in coral skeletons as the composition changes in their environment," she explains. "Because corals are growing in water, they record that information every day as they're growing that skeleton. We have a very good idea of how old some fossils are and can get pretty precise records. I'm looking at the last 2 million years, and from a geologist's perspective, that's pretty recent."

In their paper, the researchers point out that there are no coral reefs left on the planet in pristine condition. The Gulf of Mexico reefs have experienced heat stress since the 1970s and are now considered to be in poor to fair condition. One of the reefs that is faring the best is the Flower Garden Banks, sitting on top of a salt dome in the northern Gulf of Mexico on the edge of the continental shelf. It's a five-hour boat ride to get out there, and there are oil platforms all around the coral reef because there's oil underneath the salt dome that the corals are growing on top of.

"In my opinion, that's the most beautiful reef in US waters," DeLong said. "Unfortunately, a lot of people don't see it because it's so remote."

Major threats to all reefs are changes in seawater pH and carbonate chemistry, which significantly reduce coral biomineralization, which turns an animal--the coral--into what's essentially rock, or calcium carbonate.

"You can think of coral as an individual building, while a reef is a whole city," DeLong explains. "There are sponges and algae, too, but coral is the foundation species that makes the reef work. Without coral, it would be like trying to build a city without concrete."

As this "concrete" weakens, it's likely to suffer worse damage by storms, which will increase in intensity and severity with rising temperatures.

"If you lose a coral reef, you lose everyone who lives there and everyone who depends on what lives there," DeLong continues. "Juvenile fish, such as the red snapper we all love to eat, and Caribbean spiny lobsters live on reefs in the Gulf of Mexico. Reefs are nurseries for a lot of the fisheries we depend on for food."

DeLong's team found that the only way to prevent severe damage to Gulf of Mexico reefs would be to limit global warming to 1.5 degrees Celsius by 2100 and stabilize atmospheric carbon dioxide below 2005 levels by limiting our use of fossil fuels--something they call a "lofty target."

"If we limit greenhouse gas emissions, and don't go on with business as usual, we can stop the temperatures from going up, keep Greenland and Antarctica from melting more, and sea levels from rising," DeLong said. "As coral reefs build structure--rock--they help break up waves when big storms come through. Reefs break up wave energy and protect our coasts from storm surge, so we have many reasons to care about them."

"Although LSU's campus is about 30 feet above sea level, we're still in a low-lying coastline," she continued. "This past summer, for example, there was great worry about flooding from the Mississippi River with Hurricane Barry. Storm surge and river flooding do not mix, and we were very fortunate that Barry didn't drop a lot of rain on us. We got lucky; the levees worked, but every time there's a flood event or storm, we're more and more susceptible. National Oceanic and Atmospheric Administration predictions for Category 5 storms are now showing storm surge from the Gulf of Mexico going as far north as LSU's campus and we're three hours from the coast! Hopefully, that will never happen, but we all have to worry about this and be concerned."

Laboratory research is the possibly best-known driving force for advancement in science. However, when it comes to investigating evolutionary processes, lab work often faces its limitations. This is where the power of big data and computational modelling comes into play. A recent joint effort from the Bielefeld University and the Leibniz Institute of Plant Genetics and Crop Plant Research (IPK) in Gatersleben to understand the evolution of C4 photosynthesis, demonstrates the potential of in silico modelling in science. Using constraint-based modelling, the researchers were able to step back in time and predict the evolutionary pathway of this particular form of photosynthesis.

All plants, algae and select bacteria perform photosynthesis, converting water and carbon dioxide (CO2) into glucose with the help of energy from sunlight. As they all produce their own food, they are classed as autotroph organisms. However, the process of photosynthesis is not the same in all autotrophs. The most common type of photosynthesis in plants is the C3 photosynthesis. It relies on the enzyme Rubisco for the fixation of CO2. Despite its prevalence in the plant-world, the C3 process has its downsides, as the function of Rubisco is slow and also unspecific. Instead of fixing CO2, plants can accidentally fix oxygen, thus producing toxic by-products which need to be recycled. To avoid these detrimental aspects, plants evolved alternative photosynthesis types. One alternative, C4 photosynthesis, independently evolved at least 62 times in 19 different families of flowering plants. Plants with the C4 trait intensify their carbon fixation by using a biochemical pump to increase the concentration of CO2 at the site of Rubisco. As a result, C4 plants, such as maize, are known to have high growth rates. In a recent project, two researchers from the Bielefeld University and the IPK in Gatersleben applied constraint-based modelling (CBM) in order to find out which selective pressures lead to the evolution of the C4 pathway.

CBM enables researchers to apply different physical, enzymatic, and topological constraints when modelling metabolic networks. Therefore, different computational predictions can be made for a row of differing experimental scenarios, letting scientists glimpse the various possible routes evolution took or could have taken, depending on the settings of the constraints. After developing their C4-CBM-model the two scientists, Prof. Andrea Bräutigam, professor for computational biology at Bielefeld's Center for Biotechnology (CeBiTec) at Bielefeld University, and Dr. Mary-Ann Blätke, a member of the Network Analysis and Modelling IPK research group, focused on finding the constraints which led to the prediction of C4 photosynthesis as the optimal solution. Prof. Bräutigam: "Once the models are set up, observation of in silico evolution becomes possible. In our case, the simulations reproduced the evolutionary trajectory from C3 to C4 photosynthesis, which depended on the carbon dioxide level." Dr. Blätke complemented: "The model also predicts intermediacy as an optimal solution under particular conditions and explains why different variations of C4 photosynthesis may exist. It also put forth nitrogen and light as new eco-physiological parameters which play a role for the evolution of C4 photosynthesis."

The study showcases CBM as a powerful tool for querying and understanding the evolution of other complex traits in plants. Simultaneously, the successful analysis of the C4 evolution paves the way for the more detailed investigation of the C4 evolution and metabolism but also highlights new targets for future breeding and engineering efforts in C4-crop plants. Dr. Blätke: "A metabolic network correctly predicting the trajectory of C4 evolution, such as the one provided here, is a prerequisite to approach more detailed questions on C4 metabolism and its evolution. It can therefore be used as a working horse for follow-up studies and act as an integrative framework for multi-omic data and derived regulatory networks.".

Success with improving a model plant's response to harsh conditions is leading plant molecular researchers to move to food crops including wheat, barley, rice and chickpeas.

Flinders and La Trobe University researchers in Australia are focusing on genes that encode antioxidant enzymes to minimise harmful oxidative responses in leaf cells to environmental stress. Experiments showed the plant with enhanced enzyme levels becoming more hardy and recovering more readily from exposure to drought and 'high light'.

"With heatwaves, drought and salinity becoming more and more of an issue, plant biologists around the world are increasingly looking for ways to equip plants to be tolerant to multiple environmental stressors," says Strategic Professor in Plant Biology David Day.

"Our research is proof of concept using the test plant Arabidopsis (Arabidopsis thaliana) that manipulating mitochondrial respiration is an important way to manage a plant's response to abiotic stresses."

The researchers focused on two enzymes, which act together to moderate oxidative damage in the leaves of the model plant.

"These proteins act on the cellular energy core or mitochondria to minimise damage caused by drought or other stressors," says Dr Crystal Sweetman, one of the lead authors on the new paper in Plant Physiology.

"Therefore, plants bred to make more of these enzymes might be able to survive extreme heat or prolonged dry weather and have a better chance at producing food during bad seasons," she says.

Flinders Professor Kathleen Soole, who is also president of the Australian Society of Plant Scientists, says the methodology has shown its value and can now be adapted for more complex grain and legume food staples.

"The research has shown that by affecting the metabolism of plant cells with two novel antioxidant enzymes allows them to recover better after exposure to drought," Professor Soole says.

Flinders Associate Professor Colin Jenkins is keen for this work to be move to food crops like cereals. "This paves the way the selection of existing crop varieties with higher activities of these enzymes and for similar genetic manipulation of crop plants such as wheat and barley," says plant molecular researcher Associate Professor Jenkins.