It’s possible that I shall make an ass of myself. But in that case one can always get out of it with a little dialectic. I have, of course, so worded my proposition as to be right either way (K.Marx, Letter to F.Engels on the Indian Mutiny)
Thursday, July 08, 2021
More EVs could reduce CO2 emissions in Hawaii by 93% in less than 30 years
By 2050, faster adoption of electric vehicles (EVs) and faster generation of renewable energy will result in 99% less fossil fuel consumed and 93% less CO2 emissions from passenger and freight vehicles on O?ahu. That's under the most ambitious scenario in an article published in World Electric Vehicle Journal, by University of Hawai?i at Mānoa School of Ocean and Earth Science and Technology (SOEST) faculty member Katherine McKenzie.
McKenzie, based at the Hawai?i Natural Energy Institute in SOEST, created mathematical models of four scenarios based on projections for the switch to electric passenger and freight vehicles, and renewable power generation. She quantified the impacts of fossil fuel use and CO2 emissions on O?ahu and found that scenarios with a slower transition to EVs result in billions more gallons of gasoline consumed, and tens of millions more tons of CO2 emitted.
As with many other remote communities still dependent on oil for both transportation and power, there remains a lack of critical analysis to determine the benefits of transitioning from internal combustion engine vehicles to plug-in electric vehicles (EVs). In 2020, average passenger EVs were found to consume the equivalent of 66 gallons of gasoline, seven times less fossil fuel than their gasoline-powered counterparts, which used 455 gallons. Average EVs also cut emissions in half, two metric tons of CO2 versus four metric tons of CO2.
"Continuing to purchase anything powered by petroleum locks in emissions and energy insecurity for years to come, at a time when decarbonization is a climate imperative," said McKenzie. "A shift is needed to energy efficient modes of travel--such as bicycling, walking and transit, along with reducing vehicle miles traveled (by "smart" city planning and remote work for example)."
CAPTION
CO2 emissions decrease dramatically as electric vehicles and renewable energy are adopted.
CREDIT
McKenzie (2021)
Human-driven habitat change leads to physical, behavioral change in mosquitofish
Bahamian mosquitofish in habitats fragmented by human activity are more willing to explore their environment, more stressed by change and have smaller brain regions associated with fear response than mosquitofish from unaffected habitats. The new study from North Carolina State University shows that these fish have adapted quickly in specific ways to human-driven change, and cautions that environmental restoration projects should understand these changes so as not to damage adapted populations.
The Bahamas mosquitofish is a small, coastal fish species that frequently inhabits tidal creeks - shallow, tidally influenced marine ecosystems. In the 1960s and 70s, road construction in The Bahamas caused many of these habitats to become "fragmented," or largely cut off from the ocean.
"Mosquitofish in these fragmented areas suddenly found themselves in a much different environment than previously, in terms of things like predation and tidal dynamics," says Brian Langerhans, associate professor of biology at NC State and corresponding author of the study. "We set out to determine how natural variation in structural habitat complexity and human-induced fragmentation influenced exploratory behavior, stress response, and brain anatomy."
Langerhans and a team of NC State researchers observed about 350 mosquitofish from seven different populations: three fragmented and four non-fragmented. The habitats varied in complexity, from simple mud-bottomed spaces to those that included a large number of rocks and vegetation, such as mangroves.
"We were testing predictions based upon our understanding of natural selection," Langerhans says. "For instance, in a fragmented space with fewer natural predators, we hypothesized that those fish would be more exploratory, since exploratory behavior could be rewarded in terms of competing for food. We also wanted to see if there were physiological changes to the areas of the brain that are associated with those and other similar behaviors."
The team measured stress response and exploratory behavior by temporarily placing mosquitofish in a different environment and observing changes in respiration and their willingness to explore. They also compared brain size in fish from the different habitats.
They found that overall, fish from a more complex environmental habitat were more willing to explore new environments. But for a given level of habitat complexity, fish in fragmented sites were more exploratory than those from unfragmented sites. In addition, fish from fragmented habitats had a higher stress response to change.
"These findings were in line with our expectations," Langerhans says. "Exploratory behavior can reward fish in habitats with few predators by helping them compete for food, and can give fish in complex habitats an advantage in locating safety and hard-to-find food resources. As for the stress response, fish in unfragmented tidal creeks with lots of predators and high tidal dynamics have a higher level of everyday stress than those in more static, predator-free habitats. Change will be much more stressful for fish in the latter areas, since they're less stressed to begin with."
They also noted that while there were no overall differences in brain size between fish from differing habitats, fish from fragmented environments had a smaller telencephalon - the region of the brain associated with fear response, while fish in complex environments had a larger optic tectum and cerebellum, brain regions associated with responding to visual stimuli, motor skills, and associative learning.
"Brain tissue is expensive for an organism to produce," Langerhans says. "If fish in fragmented or simple environments no longer experience major demands for behaviors such as avoiding predation or navigating complex situations, seeing changes in these brain areas isn't that surprising."
The study also highlights how quickly organisms adapt to new environments, and how those environments affect the biological makeup of their inhabitants - something that restoration project planners should keep in mind when attempting to restore habitats to their ancestral state.
"Everything that humans plan to do to these environments should have a lot of forethought put into it," Langerhans says. "If local adaptations occurred over a 50-year period in response to an altered environment and we quickly restore it to 'normal,' you could do more harm than good to some of its inhabitants."
The research appears in the Journal of Animal Ecology, and was supported by NC State's W.M. Keck Center for Behavioral Biology, the Helge Axson Johnson Foundation, and the Swedish Research Council (Grant 2015-00300). NC State graduate student Matthew Jenkins is first author. NC State undergraduates John Cummings and Alex Cabe, fisheries and wildlife professor Nils Peterson, and former NC State postdoctoral researcher Kaj Hulthén, also contributed to the work.
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Note to editors: An abstract follows.
"Natural and anthropogenic sources of habitat variation influence exploration behaviour, stress response, and brain morphology in a coastal fish"
DOI: 10.1111/1365-2656.13557
Authors: Matthew R. Jenkins, John M. Cummings, Alex R. Cabe, Kaj Hulthén, M. Nils Peterson, R. Brian Langerhans, North Carolina State University
Published: Journal of Animal Ecology
Abstract: Evolutionary ecology aims to better understand how ecologically important traits respond to environmental heterogeneity. Environments vary both naturally and as a result of human activities, and investigations that simultaneously consider how natural and human-induced environmental variation affect diverse trait types grow increasingly important as human activities drive species endangerment. Here, we examine how habitat fragmentation and structural habitat complexity, affect disparate trait types in Bahamas mosquitofish (Gambusia hubbsi) inhabiting tidal creeks. We tested a priori predictions for how these factors might influence exploratory behaviour, stress reactivity, and brain anatomy. We examined approximately 350 adult Bahamas mosquitofish from seven tidal creek populations across Andros Island, The Bahamas that varied in both human-caused fragmentation (three fragmented, four unfragmented) and natural habitat complexity (e.g. 5-fold variation in rock habitat). Populations that had experienced severe human-induced fragmentation, and thus restriction of tidal exchange from the ocean, exhibited greater exploration of a novel environment, stronger physiological stress responses to a mildly stressful event, and smaller telencephala (relative to body size). These changes matched adaptive predictions based mostly on 1) reduced chronic predation risk and 2) decreased demands for navigating tidally dynamic habitats. Populations from sites with greater structural habitat complexity showed a higher propensity for exploration and a relatively larger optic tectum and cerebellum. These patterns matched adaptive predictions related to increased demands for navigating complex environments. Our findings demonstrate environmental variation, including recent anthropogenic impacts (<50 years), can significantly affect complex, ecologically important traits. Yet trait-specific patterns may not be easily predicted, as we found strong support for only six of 12 predictions. Our results further highlight the utility of simultaneously quantifying multiple environmental factors--e.g. had we failed to account for habitat complexity, we would not have detected effects of fragmentation on exploratory behaviours. These responses, and their ecological consequences, may be complex: rapid and adaptive phenotypic responses to anthropogenic impacts can facilitate persistence in human-altered environments, but may come at a cost of population vulnerability if ecological restoration were to occur without consideration of the altered traits.
Disclaimer: AAAS and EurekAlert! are not responsible for the accuracy of
Wastewater did not significantly alter seismic stress direction in southern Kansas
Although wastewater disposal has been the primary driving force behind increased earthquake activity in southern Kansas since 2013, a new study concludes that the disposal has not significantly changed the orientation of stress in the Earth's crust in the region.
Activities like wastewater disposal can alter pore pressure, shape and size within rock layers, in ways that cause nearby faults to fail during an earthquake. These effects are thought to be behind most recent induced earthquakes in the central and eastern United States.
It is possible, however, that human activity could also lead to earthquakes by altering the orientation of stresses that act on faults in the region, said U.S. Geological Survey seismologist Robert Skoumal, who co-authored the study in Seismological Research Letters with USGS seismologist Elizabeth Cochran.
"Since we do not see evidence for a significant stress rotation [in the region], we think most of the earthquakes in southern Kansas are due to changes in pore pressures or porelastic effects rather than due to stress rotations," Skoumal said.
One way that researchers can learn more about the orientation of the stress field in rock layers where fluid fills fractures in the rock is through a seismic wave effect called shear wave splitting. Some of the shear waves traveling through the rock move parallel to open fractures and are therefore faster, while others move perpendicular to the fractures and have a lower velocity. Estimating the direction of the fast waves can help determine the orientation of the stress field.
A previous shear wave splitting study in southern Kansas estimated a 90-degree rotation in the fast direction beginning in 2015, which the study authors attributed to elevated pore fluid pressures from wastewater disposal. However, the rotation coincided with a change in the stations used to observe the shear waves.
Skoumal and Cochran decided to take another look at stress changes in southern Kansas as part of a larger effort to characterize stress in rock reservoirs without drilling expensive boreholes. When they analyzed shear wave splitting using high-quality data collected from a stable local seismic network, they found that the regional stress orientation remained relatively constant between 2014 and 2017.
The geological conditions of a wastewater reservoir might affect whether injection can alter stress orientation, Skoumal noted. Most of the wastewater injected in southern Kansas went into rock layers called the Arbuckle Group, "which is underpressurized--fluid can be 'poured in' without the need of a pump," Skoumal said, noting that pore pressures can diffuse rapidly in the highly permeable rock.
There are no reports of significant stress rotations due to wastewater disposal, the authors note, suggesting that it may either not be a common occurrence, the stress rotations are smaller than can be detected with current methods, or that the phenomenon hasn't been studied enough. Until recently, seismic instrumentation has been sparse in many places that have experienced a large increase in wastewater disposal over the past decade.
"Documenting stress orientations is already challenging in these regions, and characterizing changes in those stresses over time is an even greater challenge," Skoumal said. "In the areas where we have looked though, we haven't seen compelling evidence for significant stress rotations due to wastewater disposal."
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Reducing the melting of the Greenland ice cap using solar geoengineering?
A study conducted by ULiège climatologists using the MAR climate model looks at the feasibility and impact of using such technologies
Injecting sulphur into the stratosphere to reduce solar radiation and stop the Greenland ice cap from melting. An interesting scenario, but not without risks. Climatologists from the University of Liège have looked into the matter and have tested one of the scenarios put forward using the MAR climate model developed at the University of Liège. The results are mixed and have been published in the journal The Cryosphere.
The Greenland ice sheet will lose mass at an accelerated rate throughout the 21st century, with a direct link between anthropogenic greenhouse gas emissions and the extent of Greenland's mass loss. To combat this phenomenon, and therefore global warming, it is essential to reduce our greenhouse gas emissions. Every day new ideas emerge to slow down global warming, such as the use of solar geoengineering, a climate intervention that consists of artificially reducing solar radiation above the ice caps and thus limiting the melting of the ice. How can this be done? The idea is to inject sulphur into the stratosphere, a stable meteorological zone located between 8 and 15 km above sea level in the atmosphere," explains Xavier Fettweis,climatologist and director of the Climatology Laboratory at ULiège. The sulphur will then act as a sort of mirror that will reflect part of the solar radiation back into space". An intervention which therefore makes it possible to reduce the amount of sunshine on earth, similar to what happens during volcanic eruptions. In 1991, the eruption of Pinatubo (Philippines) injected millions of tonnes of sulphur dioxide into the stratosphere, causing a drop in global temperatures of around 0.5°C. This observation led to the development of solar geoengineering scenarios. Are these scenarios really reliable and risk-free? This is what the ULiège climatologists wanted to test.
We used a plausible scenario of solar geoengineering (G6solar) that would reduce global warming by a factor of 2 on a global scale compared with the most pessimistic scenario in which nothing would be done about the climate," continues Xavier Fettweis. By forcing the MAR (Regional Atmospheric Model) developed at ULiège to use this scenario, we show that the reduction in solar radiation associated with this scenario would make it possible to locally reduce the melting at the surface of the Greenland ice sheet by 6% in addition to the global reduction in global warming. While these results seem encouraging, the researchers insist that this type of scenario would not be sufficient to maintain the ice cap in a stable state by the end of this century. Moreover, this type of intervention is not without risk since it could have a significant impact on the ozone layer and on water cycles and precipitation, accentuating the disparities between wet and dry regions. Only solar geoengineering scenarios, which are much more ambitious but becoming unrealistic and dangerous, would make it possible to save the cap," concludes Xavier Fettweis. We are talking here about human and intentional intervention in the climate. A plan B that is not! It is therefore urgent to drastically reduce our greenhouse gas emissions by means that we know but are struggling to implement.
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NASA space lasers map meltwater lakes in Antarctica with striking precision
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
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.
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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
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
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
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.
