NASA space lasers map meltwater lakes in Antarctica with striking precision

NASA/GODDARD SPACE FLIGHT CENTER

Research News

IMAGE: NASA RESEARCHERS ON THE SURFACE OF THE ANTARCTIC ICE SHEET AS PART OF THE 88-SOUTH TRAVERSE IN 2019. THE 470-MILE EXPEDITION IN ONE OF THE MOST BARREN LANDSCAPES ON EARTH... view more 

CREDIT: CREDIT: NASA'S GODDARD SPACE FLIGHT CENTER/DR. KELLY BRUNTom above, the Antarctic Ice Sheet might look like a calm, perpetual ice blanket that has covered Antarctica for millions of years. But the ice sheet can be thousands of meters deep at its thickest, and it hides hundreds of meltwater lakes where its base meets the continent's bedrock. Deep below the surface, some of these lakes fill and drain continuously through a system of waterways that eventually drain into the ocean.

Now, with the most advanced Earth-observing laser instrument NASA has ever flown in space, scientists have improved their maps of these hidden lake systems under the West Antarctic ice sheet--and discovered two more of these active subglacial lakes.

The new study provides critical insight for spotting new subglacial lakes from space, as well as for assessing how this hidden plumbing system influences the speed at which ice slips into the Southern Ocean, adding freshwater that may alter its circulation and ecosystems.

NASA's Ice, Cloud and land Elevation Satellite 2, or ICESat-2, allowed scientists to precisely map the subglacial lakes. The satellite measures the height of the ice surface, which, despite its enormous thickness, rises or falls as lakes fill or empty under the ice sheet.

The study, published July 7 in Geophysical Research Letters, integrates height data from ICESat-2's predecessor, the original ICESat mission, as well as the European Space Agency's satellite dedicated to monitoring polar ice thickness, CryoSat-2.

Hydrology systems under the Antarctic ice sheet have been a mystery for decades. That began to change in 2007, when Helen Amanda Fricker, a glaciologist at Scripps Institution of Oceanography at the University of California San Diego, made a breakthrough that helped update classical understanding of subglacial lakes in Antarctica.

Using data from the original ICESat in 2007, Fricker found for the first time that under Antarctica's fast flowing ice streams, an entire network of lakes connect with one another, filling and draining actively over time. Before, these lakes were thought to hold meltwater statically, without filling and draining.

"The discovery of these interconnected systems of lakes at the ice-bed interface that are moving water around, with all these impacts on glaciology, microbiology, and oceanography--that was a big discovery from the ICESat mission," said Matthew Siegfried, assistant professor of geophysics at Colorado School of Mines, Golden, Colo. and lead investigator in the new study. "ICESat-2 is like putting on your glasses after using ICESat, the data are such high precision that we can really start to map out the lake boundaries on the surface."

Scientists have hypothesized subglacial water exchange in Antarctica results from a combination of factors, including fluctuations in the pressure exerted by the massive weight of the ice above, the friction between the bed of the ice sheet and the rocks beneath, and heat coming up from the Earth below that is insulated by the thickness of the ice. That's a stark contrast from the Greenland ice sheet, where lakes at the bed of the ice fill with meltwater that has drained through cracks and holes on the surface.

To study the regions where subglacial lakes fill and drain more frequently with satellite data, Siegfried worked with Fricker, who played a key role in designing the way the ICESat-2 mission observes polar ice from space.

Siegfried and Fricker's new research shows that a group of lakes including the Conway and Mercer lakes under the Mercer and Whillans ice streams in West Antarctica are experiencing a draining period for the third time since the original ICESat mission began measuring elevation changes on the ice sheet's surface in 2003. The two newly found lakes also sit in this region.

In addition to providing vital data, the study also revealed that the outlines or boundaries of the lakes can change gradually as water enters and leaves the reservoirs.

"We're really mapping out any height anomalies that exist at this point," Siegfried said. "If there are lakes filling and draining, we will detect them with ICESat-2."

'Helping Us Observe' Under the Ice Sheet

Precise measurements of basal meltwater are crucial if scientists want to gain a better understanding of Antarctica's subglacial plumbing system, and how all that freshwater might alter the speed of the ice sheet above or the circulation of the ocean into which it ultimately flows.

An enormous dome-shaped layer of ice covering most of the continent, the Antarctic ice sheet flows slowly outwards from the central region of the continent like super thick honey. But as the ice approaches the coast, its speed changes drastically, turning into river-like ice streams that funnel ice rapidly toward the ocean with speeds up to several meters per day. How fast or slow the ice moves depends partly on the way meltwater lubricates the ice sheet as it slides on the underlying bedrock.

As the ice sheet moves, it suffers cracks, crevasses, and other imperfections. When lakes under the ice gain or lose water, they also deform the frozen surface above. Big or small, ICESat-2 maps these elevation changes with a precision down to just a few inches using a laser altimeter system that can measure Earth's surface with unprecedented detail.

Tracking those complex processes with long-term satellite missions will provide crucial insights into the fate of the ice sheet. An important part of what glaciologists have discovered about ice sheets in the last 20 years comes from observations of how polar ice is changing in response to warming in the atmosphere and ocean, but hidden processes such as the way lake systems transport water under the ice will also be key in future studies of the Antarctic Ice Sheet, Fricker said.

"These are processes that are going on under Antarctica that we wouldn't have a clue about if we didn't have satellite data," Fricker said, emphasizing how her 2007 discovery enabled glaciologists to confirm Antarctica's hidden plumbing system transports water much more rapidly than previously thought. "We've been struggling with getting good predictions about the future of Antarctica, and instruments like ICESat-2 are helping us observe at the process scale."

'A Water System That Is Connected to the Whole Earth System'

How freshwater from the ice sheet might impact the circulation of the Southern Ocean and its marine ecosystems is one of Antarctica's best kept secrets. Because the continent's subglacial hydrology plays a key role in moving that water, Siegfried also emphasized the ice sheet's connection to the rest of the planet.

"It's not just the ice sheet we're talking about," Siegfried said. "We're really talking about a water system that is connected to the whole Earth system."

Recently, Fricker and another team of scientists explored this connection between freshwater and the Southern Ocean--but this time by looking at lakes near the surface of an ice shelf, a large slab of ice that floats on the ocean as an extension of the ice sheet. Their study reported that a large, ice-covered lake collapsed abruptly in 2019 after a crack or fracture opened from the lake floor to the base of Amery Ice Shelf in East Antarctica.

With data from ICESat-2, the team analyzed the rugged change on the landscape of the ice shelf. The event left a doline, or sinkhole, a dramatic depression of about four square miles (about 10 square kilometers), or more than three times the size of New York City's Central Park. The crack funneled nearly 200 billion gallons of freshwater from the surface of the ice shelf into the ocean below within three days.

During the summer, thousands of turquoise meltwater lakes adorn the bright white surface of Antarctica's ice shelves. But this abrupt event occurred in the middle of the winter, when scientists expect water on the surface of the ice shelf to be completely frozen. Because ICESat-2 orbits Earth with exactly repeating ground tracks, its laser beams can show the dramatic change in the terrain before and after the lake drained, even during the darkness of polar winter.

Roland Warner, a glaciologist with the Australian Antarctic Program Partnership at the University of Tasmania, and lead author of the study, first spotted the scarred ice shelf in images from Landsat 8, a joint mission of NASA and the U.S. Geological Survey. The drainage event was most likely caused by a hydrofracturing process in which the mass of the lake's water led to a surface crack being driven right through the ice shelf to the ocean below, Warner said.

"Because of the loss of this weight of water on the surface of the floating ice shelf, the whole thing bends upwards centered on the lake," Warner said. "That's something that would have been difficult to figure out just staring at satellite imagery."

Meltwater lakes and streams on Antarctica's ice shelves are common during the warmer months. And because scientists expect these meltwater lakes to be more common as air temperatures warm, the risk of hydrofracturing could also increase in coming decades. Still, the team concluded it's too early to determine whether warming in Antarctica's climate caused the demise of the observed lake on Amery Ice Shelf.

Witnessing the formation of a doline with altimetry data was a rare opportunity, but it is also the type of event glaciologists need to analyze in order to study all of the ice dynamics that are relevant in models of Antarctica.

"We have learned so much about ice sheet dynamic processes from satellite altimetry, it is vital that we plan for the next generation of altimeter satellites to continue this record," Fricker said.

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By Roberto Molar Candanosa NASA's Earth Science News Team

 

How plants compensate symbiotic microbes

STANFORD UNIVERSITY

Research News

 

IMAGE: THE RESEARCHERS' EQUATION REPRESENTING "PAYMENTS " FROM PLANTS TO MICROBES, WHERE Α (ALPHA) IS THE RATIO OF CARBON THE PLANT ALLOCATES TO TWO MICROBES AND Β (BETA) IS THE RATIO OF... view more 

CREDIT: COURTESY OF THE PEAY LAB/BRIAN STEIDINGER

"Equal pay for equal work," a motto touted by many people, turns out to be relevant to the plant world as well. According to new research by Stanford University ecologists, plants allocate resources to their microbial partners in proportion to how much they benefit from that partnership.

"The vast majority of plants rely on microbes to provide them with the nutrients they need to grow and reproduce," explained Brian Steidinger, a former postdoctoral researcher in the lab of Stanford ecologist, Kabir Peay. "The problem is that these microbes differ in how well they do the job. We wanted to see how the plants reward their microbial employees."

In a new study, published July 6 in the journal American Naturalist, the researchers investigated this question by analyzing data from several studies that detail how different plants "pay" their symbionts with carbon relative to the "work" those symbionts perform for the plants - in the form of supplying nutrients, like phosphorus and nitrogen. What they found was that plants don't quite achieve "equal pay" because they tend not to penalize low-performing microbes as much as would be expected in a truly equal system. The researchers were able to come up with a simple mathematical equation to represent most of the plant-microbe exchanges they observed.

"It's a square root relationship," said Peay, who is an associate professor of biology in the School of Humanities and Sciences. "Meaning, if microbe B does one-quarter as much work as microbe A, it still gets 50 percent as many resources - the square root of one-quarter."

When the researchers tested their equation against 13 measurements of plant resource exchange with microbe partners, they were able to explain around 66 percent of the variability in the ratio of plant payments to two different microbes.

"The biggest surprise was the simplicity of the model," said Steidinger. "You don't get a lot of short equations in ecology. Or anywhere else."

The fruit of frustration When asked about the motivation for developing this equation, Steidinger summed it up with one word: frustration.

"There is a lot of really interesting literature in a field called 'biological market theory' that deals with how plants should preferentially allocate resources. But for the folks who actually run experiments, it is difficult to translate these models into clean predictions," said Steidinger. "We wanted to make that clean prediction."

CAPTION

Illustrations describing Weber's Law concerning human perception, and how it potentially works as an analogy for why plants allocate a disproportionate amount of resources to less beneficial microbes.

CREDIT

Courtesy of the Peay Lab/Brian Steidinger

An informal survey of the Peay lab members encouraged the researchers to start with the assumption of equal pay because most people agreed it was reasonable to guess that plants treat all microbes the same. To reach their final equation, Steidinger and Peay then factored in the diminishing returns seen in the fertilizer models and assessed them through the lens of biological market theory literature - which uses human markets as a mathematical analogy for exchanges of services in the natural world.

"It turns out if the plant is flush with resources - in this case, the sugars it feeds to its microbes - and if the nutrients are valuable enough, the plant pays its microbes according to a square-root law," said Peay.

The square-root model is a strong start to addressing Steidinger's original frustration but it is not quite at the level of realism he wants to eventually achieve.

"For instance, our model allows a useless microbe to be fired without the plant losing resources," said Steidinger. "But, just as in the human world, it takes an investment to hire a microbe and that initial investment is a gamble that microbial layabouts can consume at their leisure."

Weber's Law In an attempt to explain why plants follow the square-root model, the researchers turned to a law in psychology. Weber's Law addresses how humans perceive differences in stimuli, such as noise, light or the size of different objects. It explains that, the stronger the stimuli, the worse we are at identifying when it changes. This law has been shown to hold for many non-human animals as well - describing, for example, how birds and bats forage for food and how fish school. Now the researchers suggest it's a good analogy for their plant payment scheme too.

"Our model says that plant should go easy on low-performing microbes, seemingly overpaying the 25-percent-as-good microbe with 50 percent as much resources," said Peay. "Well, it's long been known that humans and non-human animals sense differences in quantity in a way that might bias them towards similar leniency."

In other words, the researchers suggest that, like a human trying to detect the volumes of specific noises in a loud room, a plant making optimal payment decisions may be relatively insensitive to differences in the quality of its microbial employees. And the researchers argue that this insensitivity may be for the best, as it encourages plants to maintain a certain level of microbial diversity, which can help give the plant options for dealing with environmental changes it encounters throughout its lifetime.

"I think what we're seeing is plants behave like animals not because they have the same perceptional limitations - and certainly not because they think like animals - but because we face similar challenges in making the best choices when there are diminishing returns on investment," says Steidinger.

###

This research was funded by the U.S. Department of Energy Office of Science, Office of Biological & Environmental Research, Early Career Research Program; the National Science Foundation Division of Environmental Biology; and an Alexander von Humboldt Postdoctoral Research Fellowship.

Energycane produces more biodiesel than soybean at a lower cost

UNIVERSITY OF ILLINOIS COLLEGE OF AGRICULTURAL, CONSUMER AND ENVIRONMENTAL SCIENCES

Research News

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IMAGE: UNIVERSITY OF ILLINOIS RESEARCHERS (L TO R) STEVE LONG, SHRADDHA MAITRA, VIJAY SINGH, AND DEEPAK KUMAR CONDUCTED A SERIES OF STUDIES ON BIOFUEL PRODUCTION FROM ENERGYCANE. view more 

CREDIT: UNIVERSITY OF ILLINOIS.

URBANA, Ill. ¬- Bioenergy from crops is a sustainable alternative to fossil fuels. New crops such as energycane can produce several times more fuel per acre than soybeans. Yet, challenges remain in processing the crops to extract fuel efficiently.

Four new studies from the University of Illinois explore chemical-free pretreatment methods, development of high-throughput phenotyping methods, and commercial-scale techno-economic feasibility of producing fuel from energycane in various scenarios.

The studies are part of the ROGUE (Renewable Oil Generated with Ultra-productive Energycane) project at U of I. ROGUE focuses on bioengineering accumulation of triacylglycerides (TAGs) in the leaves and stems of energycane, enabling the production of much more industrial vegetable oil per acre than previously possible.

"The productivity of these non-food crops is very high per unit of land. Soybean is the traditional crop used for biodiesel, but we can get higher yield, more oil, and subsequently more biofuel from lipid-producing energycane," says Vijay Singh, Founder professor in the Department of Agricultural and Biological Engineering (ABE) at U of I and co-author on all four papers.

Biofuel production from crops involves breaking down the cellulosic material and extracting the oil in a series of steps, explains study co-author Deepak Kumar, assistant professor in the Chemical Engineering Department at State University of New York College of Environmental Science and Forestry (SUNY-ESF) and adjunct research scientist at the Carl R. Woese Institute for Genomic Biology at U of I.

"The first step is to extract the juice. That leaves bagasse, a lignocellulosic material you can process to produce sugars and subsequently ferment to bioethanol," Kumar says.

"One of the critical things in processing any lignocellulosic biomass is a pretreatment step. You need to break the recalcitrant structure of the material, so enzymes can access the cellulose," he adds. "Because energycane is a relatively new crop, there are very few studies on the pretreatment and breakdown of this bagasse to produce sugars, and to convert those sugars into biofuels."

The pretreatment process also yields some unwanted compounds, which inhibit enzymes that convert the sugar into biofuels. The U of I researchers investigated the best pretreatment methods to maximize the breakdown while minimizing the production of inhibitors. Typically, the pretreatment process uses chemicals such as sulfuric acid to break down the biomass at high temperature and pressure.

"We use a chemical-free method, which makes it more environmentally friendly," Kumar explains. "Furthermore, harsh chemicals may alter the oil structure or quality in the biomass."

The researchers tested their method using nine different combinations of temperature and time intervals. They were able to achieve more than 90% cellulose conversion at the optimal conditions, which is equivalent to results from chemical pretreatment methods.

The second study built on those results to further investigate the relationship between temperature, inhibitor production, and sugar recovery.

"We pretreated the lignocellulosic biomass over a range of different temperatures to optimize the condition for minimal inhibitor generation without affecting the sugar recovery. Then we added cryogenic grinding to the process," says Shraddha Maitra, postdoctoral research associate in ABE and lead author on the study.

"In cryogenic grinding, you treat the bagasse with liquid nitrogen, which makes it very brittle, so upon grinding the biomass fractures easily to release the sugars. This further increased sugar recovery, mainly xylose, by about 10% compared to other refining processes," Maitra explains.

Other industries use similar methods, for example for spices and essential oils, where it is important to preserve the qualities of the product. But applying them to biofuel production is new.

In a third study, Maitra and her co-authors investigated time-domain nuclear magnetic resonance (NMR) technology to determine the stability and recovery of lipids by monitoring changes in total, bound, and free lipids after various physical and chemical feedstock preprocessing procedures.

The research team's fourth study investigated the commercial-scale techno-economic feasibility of engineered energycane-based biorefinery. They used computer modeling to simulate the production process under two different scenarios to determine capital investment, production costs, and output compared with soybean-based biodiesel.

"Although the capital investment is higher compared to soybean biodiesel, production costs are lower (66 to 90 cents per liter) than for soybean (91 cents per liter). For the first scenario, processing energycane had overall slightly lower profitability than soybean biodiesel, but yields five times as much biodiesel per unit of land," says Kumar, the lead author on the study.

"Energycane is attractive in its ability to grow across a much wider geography of the U.S. south east than sugarcane. This is a region with much underutilized land, yet capable of rain-fed agriculture," says ROGUE Director Steve Long, Ikenberry Endowed Chair of Plant Biology and Crop Sciences at the University of Illinois.

"As a perennial, energycane is suitable for land that might be damaged by annual crop cultivation. Our research shows the potential to produce a remarkable 7.5 barrels of diesel per acre of land annually. Together with co-products, this would be considerably more profitable than most current land use, while having the potential to contribute greatly to the national U.S. goal of achieving net zero greenhouse gas emissions by 2050. This proves how valuable it is to build on the successes already achieved in bioengineering energycane to accumulate oils that are easily converted into biodiesel and biojet," Long states.

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The first study, "Chemical free two-step hydrothermal pretreatment to improve sugar yields from energy cane," is published in Energies. [doi.org/10.3390/en13215805]. Authors include Ankita Juneja, Deepak Kumar, Vijay Kumar Singh, Yadvika, and Vijay Singh.

The second study, "Balancing sugar recovery and inhibitor generation during energycane processing: Coupling cryogenic grinding with hydrothermal pretreatment at low temperatures," is published in Bioresource Technology. [doi.org/10.1016/j.biortech.2020.124424]. Authors include Shraddha Maitra and Vijay Singh.

The third study, "Development and validation of time-domain 1H=NMR relaxometry correlation for high-throughput phenotyping method for lipid contents of lignocellulosic feedstocks," is published in GCB Bioenergy. [https://doi.org/10.1111/gcbb.12841]. Authors are Shraddha Maitra, Bruce Dien, Stephen Long, and Vijay Singh.

The fourth study, "Techno-economic feasibility analysis of engineered energycane-based biorefinery co-producing biodiesel and ethanol," is published in GCB Bioenergy. Authors include Deepak Kumar, Stephen Long, Amit Arora, and Vijay Singh. [https://doi.org/10.1111/gcbb.12871]

Partial funding for the studies was provided by the Biological and Environmental Research (BER) program, U.S. Department of Energy, under Award Number DE-SC0018254.

The Department of Agricultural and Biological Engineering is in the College of Agricultural, Consumer and Environmental Sciences and The Grainger College of Engineering, University of Illinois.

Disclai

 

Open-source software to help cities plant in pursuit of clean air

UNIVERSITY OF BIRMINGHAM

Research News

 

Software to help towns and cities use street-planting to reduce citizens' exposure to air pollution has been developed by researchers at the University of Birmingham.

Street planting, or 'green infrastructure', is an essential part of the urban realm, but there is a misconception that plants remove or 'soak up' a lot of pollution. Instead, planting at this scale primarily serves to redistribute pollution by changing air currents within streets and beside open roads.

Because of this, not only the position and amount of planting within a street, but also the layout and orientation of that street, are critical to its impacts on local air quality.

The software - the Green Infrastructure for Roadside Air Quality or 'GI4RAQ' Platform - has been designed by experts in the University of Birmingham's Institute of Forest Research (BIFoR) and School of Geography, Earth and Environmental Sciences, in partnership with practitioner organisations, including: Transport for London, Greater London Authority and Birmingham City Council. It is the result of three years' collaboration, funded principally through three Innovation grants from the Natural Environment Research Council.

Free to use and open-source, the software enables practitioners to estimate the changes in pollutant concentrations (throughout the cross-section of a street) resulting from different planting schemes. It focusses on key pollutants from road transport: NO2 (nitrogen dioxide) and PM2.5 (fine particulate matter). Its calculations draw on wind data from monitoring stations across the UK, and determine how background wind conditions interact with the local urban form and planting specified by the user.

The software's performance and underlying science are documented in a paper published last month in the open-access journal, Forests.

Lead researcher, Dr James Levine says: "In reducing our exposure to pollution from nearby vehicles, strategic planting can complement essential emission reductions in reducing health impacts. But it's not as simple as thinking that any planting will do good - if indiscriminate, it's just as likely to have a negative impact. There are many good reasons to invest in green infrastructure but, if planting in the name of improving air quality, we must ensure it delivers genuine benefits. By estimating the benefits at planning, we can ensure good schemes are robust to cost-cutting and fully realised."

Informed by their work with Dr Levine, Transport for London is currently exploring a potential 'healthy and resilient streets' scheme with the Greater London Authority. Dr Levine is also in discussion with The Mersey Forest and Liverpool City Council regarding a scheme in central Liverpool.

Paul Nolan OBE, Director of the Mersey Forest, commented: "The GI4RAQ Platform bridges the gap between academic researchers and organisations like The Mersey Forest, cutting through the often-mixed messages regarding the impacts of vegetation on urban air quality, in support of projects delivering genuine, lasting benefits."

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The GI4RAQ team is led by Dr Levine and includes: doctoral student Ms Helen Pearce, who wrote the open-source air quality code (https://github.com/GI4RAQ/GI4RAQ-open); Prof Rob MacKenzie (Director of BIFoR) and Dr Xiaoming Cai; Tommy Morrison, Chris Thompson and Matt Sadler of Wild Ilk Design Studio, who developed the web interface; all with funding from the Natural Environment Research Council through grants, NE/S00940X/1, NE/S013814/1, NE/S00582X/1 and NE/S003487/1, and studentship grant, NE/R011265/1.

Scientists show the importance of contact with nature in the city during the lockdown

RUDN UNIVERSITY

Research News

 

IMAGE: THE MEASURES TAKEN DURING THE COVID-19 PANDEMIC LIMITED THE ACCESS OF CITIZENS TO NATURAL OBJECTS. IT IS STILL UNEXPLORED, WHAT CONSEQUENCES THIS HAD FOR THE RESIDENTS AND WHAT CONCLUSIONS SHOULD... view more 

CREDIT: RUDN UNIVERSITY

The measures taken during the COVID-19 pandemic limited the access of citizens to natural objects. It is still unexplored, what consequences this had for the residents and what conclusions should be drawn for more effective urban planning. RUDN University scientists with colleagues from Australia and Germany studied how the restrictions associated with COVID-19 affected the use of blue and green infrastructure by citizens in Moscow (Russia) and Perth (Australia), and what consequences this had for their health. In the article "Human Dimensions of Urban Blue and Green Infrastructure during a Pandemic. The Case Study of Moscow (Russia) and Perth (Australia)", published in Sustainability, they presented the results of a study on the importance of green and blue infrastructure for the physical and mental health of the citizens. The results give a basis for developing a balanced strategy for landscape design and urban space planning based on the development of green infrastructure that allows effectively maintaining the well-being and health of citizens, especially during a crisis such as that caused by COVID-19.

The significant challenges caused by the COVID-19 pandemic emphasized that the concept and features of the modern environmentally balanced cities development should consider not only the implementation of economic and social urban strategies, but also functional urban design, related to the urban spaces planning and the development of green infrastructure. Using the results of a web questionnaire survey conducted in May-July 2020 in Moscow (Russia) and Perth (Australia), the article presents an analysis of the significance of contact with nature and various objects of green and blue infrastructure of cities, as well as their changes during and after the COVID-19 restrictions. In order to identify the way people relate to green and blue urban objects and what role they play in providing a comfortable environment, as well as how the general restrictions associated with COVID-19 affected the nature of their interaction with natural infrastructure, they developed a questionnaire of 25 questions, which became the basis of an online study.

216 Muscovites and 110 residents of Perth took part in the survey. The results were analysed statistically. The survey data collected during the isolation period provided information about access to green and blue urban spaces, inequalities in access, as well as changes in the development of urban green infrastructure that are necessary from the respondents' point of view. Scientists analysed the social aspects of citizens' perception of natural objects of the urban and emphasized the importance of contact with nature for maintaining physical and mental health, socio-cultural identification, and socialization (the importance of green and blue objects as social and multicultural spaces). In both cities, measures taken during the COVID-19 restricted people's access to green spaces and water bodies, which negatively affected their mental and physical health and well-being. The survey results showed that the quality, functionality, and location of open natural spaces illustrate the inequality in their distribution and accessibility to the population. In some cases, it was noted that residents of certain areas of cities suffered from limited access to natural objects.

"The COVID-19 circumstances, when access to natural urban facilities was limited for millions of people around the world, highlighted that in extraordinary situations, urban nature can play an essential role in contributing to human well-being and shaping human-nature relationships. Studies have confirmed that public green and blue spaces play a key role not only in maintaining a comfortable environmental situation, but also in restoring mental and physical health during and after an emergency. owever, the issues of how these differential impacts could influence future urban development that will make the cities sustainable and resilient towards addressing challenges, such as those associated with the COVID-19 pandemic and climate change, need to be better understood. In this sense, the comparison of experiences from cities in different countries could be very valuable," says Diana Dushkova, PhD, associate professor at the RUDN University and senior researcher at The Helmholtz-Centre for Environmental Research

The researchers compared Moscow and Perth as two cities with different approaches to the organization of natural objects and landscaping strategies. In Moscow, most of the green areas and water bodies are open to public. In Perth, more than half of the city's green infrastructure facilities are located on private territories. It turned out that residents of Perth and Moscow consider access to nature equally important, even though cities differ in size, climatic conditions, and planning approaches. In both cities, more than 60% of residents said that the opportunity of contact with nature is important or extremely important for physical and mental health. Among the main values of contact with nature, citizens noted fresh air (82.9% in Perth and 51.6% in Moscow), a sense of unity with nature (89.5% in Perth and 71.2% in Moscow), the scenic beauty (89.5% in Perth and 71.2% in Moscow). The differences in the responses of residents of the two cities are noticeable in questions that relate to the specifics of the restrictions adopted in the pandemic. Changes in visiting natural spaces before and during the pandemic are especially noticeable in Moscow, where strict restrictions were introduced. 56.9% of Muscovites visited green and water zones less often. In Perth, parks and other natural recreation areas remained open, and 59.4% of residents did not visit urban natural spaces less often, and 26.7% even began to do it even more often.

"Our results showed that urban residents are aware of the value of green and blue spaces and emphasize their important role in maintaining health and well-being, especially during the COVID-19 pandemic. This is new convincing evidence that the issues of accessibility of natural objects and their balanced distribution in urban areas should be considered in the development strategy of a modern city, which considers the new requirements of the modern world in ensuring safe and comfortable life and maintaining human health. In addition, it indicates that access to nature and public rights to use green spaces determine the overall resilience of cities to the crisis. The obtained results obtained provide the basis for further research in the development of modern approaches to landscape design and planning of urban green and water zones and allow us to see how effectively they can ensure and maintain the well-being and health of citizens, especially during a crisis such as that caused by COVID --19," says Diana Dushkova.

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A biological fireworks show 300 million years in the making

DOE/ARGONNE NATIONAL LABORATORY

Research News

IMAGE: FROG EGGS LIKE THOSE PICTURED HERE RELEASE ZINC WHEN FERTILIZED, MUCH LIKE MAMMALIAN EGGS DO. view more 

CREDIT: (IMAGE BY TERO LAAKSO/LICENSED UNDER CC BY-SA 2.0.)

Five years ago, researchers at Northwestern University made international headlines when they discovered that human eggs, when fertilized by sperm, release billions of zinc ions, dubbed "zinc sparks."

Now, Northwestern has teamed up with the U.S. Department of Energy's (DOE) Argonne National Laboratory and Michigan State University (MSU) to reveal that these same sparks fly from highly specialized metal-loaded compartments at the egg surface when frog eggs are fertilized. This means that the early chemistry of conception has evolutionary roots going back at least 300 million years, to the last common ancestor between frogs and people.

"This work may help inform our understanding of the interplay of dietary zinc status and human fertility." -- Thomas O'Halloran, professor, Michigan State University

And the research has implications beyond this shared biology and deep-rooted history. It could also help shape future findings about how metals impact the earliest moments in human development.

"This work may help inform our understanding of the interplay of dietary zinc status and human fertility," said Thomas O'Halloran, the senior author of the research paper published June 21 in the journal Nature Chemistry.

O'Halloran was part of the original zinc spark discovery at Northwestern and, earlier this year, he joined Michigan State as a foundation professor of microbiology and molecular genetics and chemistry. O'Halloran was the founder of Northwestern's Chemistry of Life Processes Institute, or CLP, and remains a member.

The team also discovered that fertilized frog eggs eject another metal, manganese, in addition to zinc. It appears these ejected manganese ions collide with sperm surrounding the fertilized egg and prevent them from entering.

"These breakthroughs support an emerging picture that transition metals are used by cells to regulate some of the earliest decisions in the life of an organism," O'Halloran said.

To make these discoveries, the team needed access to some of the most powerful microscopes in the world as well as expertise that spanned chemistry, biology and X-ray physics. That unique combination included collaborators at the Center for Quantitative Element Mapping for the Life Sciences, or QE-Map, an interdisciplinary National Institutes of Health-funded research hub at MSU and Northwestern's CLP. The research relied heavily on the tools and expertise available at Argonne.

The research team brought sections of frog eggs and embryos to Argonne for analysis. Using both X-ray and electron microscopy, the researchers determined the identity, concentrations and intracellular distributions of metals both before and after fertilization.

X-ray fluorescence microscopy was conducted at beamline 2-ID-D of the Advanced Photon Source (APS), a DOE Office of Science User Facility at Argonne. Barry Lai, group leader at Argonne and an author on the paper, said that the X-ray analysis quantified the amount of zinc, manganese and other metals concentrated in small pockets around the outer layer of the eggs. They found these pockets contained more than 30 times the manganese as the rest of the eggs, and 10 times the zinc.

"We are able to do this analysis because of the elemental sensitivity of the beamline," Lai said. "In fact, it is so sensitive that substantially lower concentrations can be measured."

Complementary scans were conducted using transmission electron microscopy at the Center for Nanoscale Materials (CNM), a DOE Office of Science User Facility at Argonne. Further analysis was performed on a separate prototype scanning transmission electron microscope that includes technology developed by Argonne Senior Scientist Nestor Zaluzec, an author on the paper. These scans were performed at smaller scales -- down to a few nanometers, about 100,000 times smaller than the width of a human hair -- but found the same results: high concentrations of metals in pockets around the outer layer.

Both X-ray and electron microscopy showed that the metals in these pockets were almost completely released after fertilization.

"Argonne has the tools necessary to examine these biological samples at these scales without destroying them with X-rays or electrons," Zaluzec said. "It's a combination of the right resources and the right expertise."

The APS is in the process of undergoing a massive upgrade, one that will increase the brightness of its X-ray beams by up to 500 times. Lai said that an upgraded APS could complete these scans much more quickly or with higher spatial resolution. What took more than an hour for this research could be done in less than one minute after the upgrade, Lai said.

"We often think of genes as key regulating factors, but our work has shown that atoms like zinc and manganese are critical to the first steps in development after fertilization," said MSU Provost Teresa K. Woodruff, Ph.D., another senior author on the paper.

Woodruff, an MSU foundation professor and former member of CLP, was also a leader of the Northwestern team that discovered zinc sparks five years ago. With the discovery of manganese sparks in African clawed frogs, or Xenopus laevis, the team is excited to explore whether the element is released by human eggs when fertilized.

"These discoveries could only be made by interdisciplinary groups, fearlessly looking into fundamental steps," she said. "Working across disciplines at the literal edge of technology is one of the most profound ways new discoveries take place."

"Xenopus is a perfect system for such studies because their eggs are an order of magnitude larger than human or mouse eggs, and are accessible in large numbers " said Carole LaBonne, another senior author on the study, CLP member, and chair of the Department of Molecular Biosciences at Northwestern. "The discovery of zinc and manganese sparks is exciting, and suggests there may be other fundamental signaling roles for these transition metals."

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About Argonne's Center for Nanoscale Materials The Center for Nanoscale Materials is one of the five DOE Nanoscale Science Research Centers, premier national user facilities for interdisciplinary research at the nanoscale supported by the DOE Office of Science. Together the NSRCs comprise a suite of complementary facilities that provide researchers with state-of-the-art capabilities to fabricate, process, characterize and model nanoscale materials, and constitute the largest infrastructure investment of the National Nanotechnology Initiative. The NSRCs are located at DOE's Argonne, Brookhaven, Lawrence Berkeley, Oak Ridge, Sandia and Los Alamos National Laboratories. For more information about the DOE NSRCs, please visit https://science.osti.gov/User-Facilities/User-Facilities-at-a-Glance.

About the Advanced Photon Source

The U. S. Department of Energy Office of Science's Advanced Photon Source (APS) at Argonne National Laboratory is one of the world's most productive X-ray light source facilities. The APS provides high-brightness X-ray beams to a diverse community of researchers in materials science, chemistry, condensed matter physics, the life and environmental sciences, and applied research. These X-rays are ideally suited for explorations of materials and biological structures; elemental distribution; chemical, magnetic, electronic states; and a wide range of technologically important engineering systems from batteries to fuel injector sprays, all of which are the foundations of our nation's economic, technological, and physical well-being. Each year, more than 5,000 researchers use the APS to produce over 2,000 publications detailing impactful discoveries, and solve more vital biological protein structures than users of any other X-ray light source research facility. APS scientists and engineers innovate technology that is at the heart of advancing accelerator and light-source operations. This includes the insertion devices that produce extreme-brightness X-rays prized by researchers, lenses that focus the X-rays down to a few nanometers, instrumentation that maximizes the way the X-rays interact with samples being studied, and software that gathers and manages the massive quantity of data resulting from discovery research at the APS.

This research used resources of the Advanced Photon Source, a U.S. DOE Office of Science User Facility operated for the DOE Office of Science by Argonne National Laboratory under Contract No. DE-AC02-06CH11357.

Argonne National Laboratory seeks solutions to pressing national problems in science and technology. The nation's first national laboratory, Argonne conducts leading-edge basic and applied scientific research in virtually every scientific discipline. Argonne researchers work closely with researchers from hundreds of companies, universities, and federal, state and municipal agencies to help them solve their specific problems, advance America's scientific leadership and prepare the nation for a better future. With employees from more than 60 nations, Argonne is managed by UChicago Argonne, LLC for the U.S. Department of Energy's Office of Science.

The U.S. Department of Energy's Office of Science is the single largest supporter of basic research in the physical sciences in the United States and is working to address some of the most pressing challenges of our time. For more information, visit https://energy.gov/science.

 

What kind of sea ice is that? Ask Knut!

A new app under development is using deep learning and artificial intelligence to classify different kinds of sea ice

NORWEGIAN UNIVERSITY OF SCIENCE AND TECHNOLOGY

Research News

 

IMAGE: THE ASK KNUT APP HAS BEEN DEVELOPED USING THOUSANDS OF DIFFERENT KINDS OF ICE PHOTOGRAPHS. THE IMAGE SHOWS WHAT THE APP SEES COMPARED TO WHAT HUMANS SEE. view more 

CREDIT: SVEINUNG LØSET/NTNU

If you've watched Netflix, shopped online, or run your robot vacuum cleaner, you've interacted with artificial intelligence, AI. AI is what allows computers to comb through an enormous amount of data to detect patterns or solve problems. The European Union says AI is set to be a "defining future technology."

And yet, as much as AI is already interwoven into our everyday lives, there's one area of the globe where AI and its applications are in their infancy, says Ekaterina Kim, an associate professor at the Norwegian University of Science and Technology's (NTNU) Department of Marine Technology. That area is the Arctic, an area where she has specialized in studying sea ice, among other topics.

"It's used a lot in marketing, in medicine, but not so much in Arctic (research) communities," she said. "Although they have a lot of data, there is not enough AI attention in the field. There's a lot of data out there, waiting for people to do something with them."

So Kim and her colleagues Ole-Magnus Pedersen, a PhD candidate from the Department of Marine Technology and Nabil Panchi, from the Indian Institute of Technology Kharagpur, decided to see if they could develop an app that used artificial intelligence to identify sea ice in the Arctic.

You may think there's not much difference between one chunk of sea ice and another, but that's just not so.

In addition to icebergs, there's deformed ice, level ice, broken ice, ice floes, floe bergs, floe bits, pancake ice and brash ice.

The researchers wanted the app to be able to distinguish between the different kinds of ice and other white and blue objects out there, like sky, open water and underwater ice.

Different kinds of ice really matter to ship captains, for example, who might be navigating in icy waters.  Actual icebergs are nothing like brash ice, the floating bits of ice that are 2 metres in diameter or less. Think of it --the Titanic wouldn't have sunk if it had just blundered into a patch of brash ice instead of a big iceberg.

Another factor that adds urgency to the situation is climate change, which is dramatically altering sea ice as oceans warm. Even with the help of satellite images and onboard ship technologies, knowing what's in icy waters ahead can be a difficult challenge, especially in fogs or storms.

"Ice can be very difficult for navigation," Kim said. "From the water (at the ship level) It can be hard to detect where there is strong ice, multiyear ice, and different ice.  Some ice is much more dangerous than other types.

The team began teaching their app's AI system using a comprehensive collection of photographs taken by another NTNU ice researcher, Sveinung Løset.

But an AI system is like a growing child -- if it is to learn, it needs to be exposed to lots of information. That's where turning the AI into an app made sense. Although the COVID-19 pandemic has shut down most cruise operations, as the pandemic wains, people will begin to take cruises again -- including to the Arctic and Antarctic.

Kim envisions tourists using the app to take pictures of different kinds of ice to see who finds the most different kinds of ice. And every one of those pictures helps the app learn.

"If the app is used for 'infotainment,'  accuracy isn't that important," Kim said.  "It can even be fun when the model makes mistakes."

As the AI learns, Kim says, the increasingly complex dataset could be taken into the classroom, where navigators could learn about ice in a much more sophisticated way.

Currently, students just look at pictures or listen to a PowerPoint presentation, where lecturers describe the different kinds of ice.

"So this could revolutionize how you learn about ice," she said. "You could have it in 3-D, you could emerge yourself and explore this digital image all around you, with links to different kinds of ice types."

The researchers are planning an AI in the Arctic workshop in September to explore AI applications in these remote areas.

"There are extreme challenges unique to the Arctic, from human activities and impacts in remote Arctic locations to Arctic data acquisition, sharing, and quality," Kim said. "We need to direct AI applications towards solving Arctic challenges that are important for the world as well as to highlight the 'black holes' or knowledge gaps and raise awareness on what does not work, needs improvements."

CAPTION

As global warming thaws Arctic sea ice, more and more ships will travel these waters. Knowing what kinds of ice they might meet can help make the journey safer. The photo shows the Swedish icebreaker Oden in broken and brash ice.

CREDIT

Sveinung Løset/NTNU

For more information about the workshop, see https://www.ntnu.edu/imt/aidingarctic

Reference: N. Panchi, E. Kim and A. Bhattacharyya, "Supplementing remote sensing of ice: Deep learning-based image segmentation system for automatic detection and localization of sea ice formations from close-range optical images," in IEEE Sensors Journal, doi: 10.1109/JSEN.2021.3084556.

 

Reading the rocks: Geologist finds clues to ancient climate patterns in chert

BINGHAMTON UNIVERSITY

Research News

BINGHAMTON, N.Y. -- A million years ago, dry seasons became more frequent and forests retreated before the encroaching savanna. Meanwhile, clustered around a nearby lake, our ancient ancestors fashioned stone tools.

During the long press of years, mud and sediment in that East African lake turned to stone, trapping pollen and microscopic organisms in its lattice. Today, researchers like Kennie Leet analyze samples of these ancient sediments, known as sediment cores, to create a picture of the environment early humans called home.

A doctoral student in geological sciences, Leet is the first author on "Labyrinth patterns in Magadi (Kenya) cherts: Evidence for early formation from siliceous gels," published in a recent issue of Geology, the leading journal in the field. Co-authors include Distinguished Professor of Geological Sciences and Environmental Studies Tim Lowenstein, her advisor, as well as Robin Renaut of Canada's University of Saskatchewan, R. Bernhart Owen of Hong Kong Baptist University and Andrew Cohen of the University of Arizona.

Leet's research is part of the National Science Foundation-funded Hominin Sites and Paleolakes Drilling Project (HSPDP), which looks at how the climate may have impacted hominin evolution in the East African rift. Overall, the project looks at the last 5 million years; Leet's portion of the project considers the last million.

She particularly focuses on the origin of the chert found in Kenya's Lake Magadi. A fine-grained rock that forms from siliceous material, chert is "cryptocrystalline," composed of crystals so small that they can't even be seen by high-powered microscopes, much less the naked eye.

Scientists believe that chert forms on the earth's surface and thus contains information about the environment at the time of its formation, she explained. Because of this quality, they can use chert to calculate the time period for particular climactic events, such as droughts -- not unusual in East Africa, where the climate oscillates between wet and dry periods.

Opening a window into the distant past, the chert points to an even larger trend.

"One of the surprising things we found was that there has been a progressive drying trend for the last million years in East Africa. It's just been progressively getting drier and drier," she said. "But in that, we still have the oscillation between wet and dry."

In the Geology article, she explores a labyrinth pattern she found in the rocks of this period. Patterns are common in nature, and this specific one is formed by drying, she explained.

"It tells us that all of the chert formation and solidification occurred near the surface, where there was exposure to air," she said. "Because this happened before the sediments were buried and compacted, there is other supporting evidence, such as really beautifully preserved plant fragments and single-celled organisms called diatoms."

The time period coincides with the region's transition from trees and forests to grasslands, which biologists and microbiologists on the team are able to track through pollen preserved in the sediment core. During that period, the early humans of Lake Magadi were also creating stone tools in new ways. Researchers wonder: Were these ancient communities moving about and trading more, prompted by drought?

Interestingly, the trend has reversed over the last decade, with the region becoming wetter. In fact, one of the places she stayed during a visit to Kenya in 2019 is now underwater, she said.

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