In a new Nature paper, an international team of scientists describe the first-ever visualization of the atomic structure of two-dimensional ice as it formed. Insights from the findings, which were driven by computer simulations that inspired experimental work, may one day inform the design of materials that make ice removal a simpler and less costly process.

“One of the things that I find very exciting is that this challenges the traditional view of how ice grows,” says Joseph S. Francisco, an atmospheric chemist at the University of Pennsylvania and an author on the paper.

“Knowing the structure is very important,” adds coauthor Chongqin Zhu, a postdoctoral fellow in Francisco’s group who led much of the computational work for the study. “Low-dimensional water is ubiquitous in nature and plays a critical role in an incredibly broad spectrum of sciences, including materials science, chemistry, biology, and atmospheric science.

“It also has practical significance. For example, removing ice is critical when it comes to things like wind turbines, which cannot function when they are covered in ice. If we understand the interaction between water and surfaces, then we might be able to develop new materials to make this ice removal easier.”

In recent years, Francisco’s lab has devoted considerable attention to studying the behavior of water, and specifically ice, at the interface of solid surfaces. What they’ve learned about ice’s growth mechanisms and structures in this context helps them understand how ice behaves in more complex scenarios, like when interacting with other chemicals and water vapor in the atmosphere.

“We’re interested in the chemistry of ice at the transition with the gas phase, as that’s relevant to the reactions that are happening in our atmosphere,” Francisco explains.

To understand basic principles of ice growth, researchers have entered this area of study by investigating two-dimensional structures: layers of ice that are only several water molecules thick.

In previous studies of two-dimensional ice, using computational methods and simulations, Francisco, Zhu, and colleagues showed that ice grows differently depending on whether a surface repels or attracts water, and the structure of that surface.

In the current work, they sought real-world verification of their simulations, reaching out to a team at Peking University to see if they could obtain images of two-dimensional ice.

The Peking team employed super-powerful atomic force microscopy, which uses a mechanical probe to “feel” the material being studied, translating the feedback into nanoscale-resolution images. Atomic force microscopy is capable of capturing structural information with a minimum of disruption to the material itself, allowing the scientists to identify even unstable intermediate structures that arose during the process of ice formation.

Virtually all naturally occurring ice on Earth is known as hexagonal ice for its six-sided structure. This is why snowflakes all have six-fold symmetry. One plane of hexagonal ice has a similar structure to that of two-dimensional ice and can terminate in two types of edges — “zigzag” or “armchair.” Usually this plane of natural ice terminates with a zigzag edges.

However, when ice is grown in two dimensions, researchers find that the pattern of growth is different. The current work, for the first time, shows that the armchair edges can be stabilized and that their growth follows a novel reaction pathway.

“This is a totally different mechanism from what was known,” Zhu says.

Although the zigzag growth patterns were previously believed to only have six-membered rings of water molecules, both Zhu’s calculations and the atomic force microscopy revealed an intermediate stage where five-membered rings were present.

This result, the researchers say, may help explain the experimental observations reported in their 2017 PNAS paper, which found that ice could grow in two different ways on a surface, depending on the properties of that surface.

In addition to lending insight into future design of materials conducive to ice removal, the techniques used in the work are also applicable to probe the growth of a large family of two-dimensional materials beyond two-dimensional ices, thus opening a new avenue of visualizing the structure and dynamics of low-dimensional matter.

For chemist Jeffrey Saven, a professor in Penn Arts & Sciences who was not directly involved in the current work, the collaboration between the theorists in Francisco’s group and their colleagues in China called to mind a parable he learned from a mentor during his training.

“An experimentalist is talking with theorists about data collected in the lab. The mediocre theorist says, ‘I can’t really explain your data.’ The good theorist says, ‘I have a theory that fits your data.’ The great theorist says, ‘That’s interesting, but here is the experiment you should be doing and why.'”

To build on this successful partnership, Zhu, Francisco, and their colleagues are embarking on theoretical and experimental work to begin to fill in the gaps related to how two-dimensional ice builds into three dimensions.

“The two-dimensional work is fundamental to laying the background,” says Francisco. “And having the calculations verified by experiments is so good, because that allows us to go back to the calculations and take the next bold step toward three dimensions.”

“Looking for features of three-dimensional ice will be the next step,” Zhu says, “and should be very important in looking for applications of this work.”

Moll was the only non-NASA physician NASA consulted when it was discovered that an astronaut aboard the ISS had a deep vein thrombosis (DVT) — or blood clot — in the jugular vein of their neck. The astronaut’s identity is being kept anonymous for privacy reasons, so identifying information such as when this event happened is being omitted from the case study. We do know that the astronaut was two months into a six-month mission on the ISS when the DVT was discovered.

This was the first time a blood clot had been found in an astronaut in space, so there was no established method of treatment for DVT in zero gravity. Moll, a member of the UNC Blood Research Center, was called upon for his vast knowledge and treatment experience of DVT on Earth.

“Normally the protocol for treating a patient with DVT would be to start them on blood thinners for at least three months to prevent the clot from getting bigger and to lessen the harm it could cause if it moved to a different part of the body such as the lungs,” Moll said. “There is some risk when taking blood thinners that if an injury occurs, it could cause internal bleeding that is difficult to stop. In either case, emergency medical attention could be needed. Knowing there are no emergency rooms in space, we had to weigh our options very carefully.”

Moll and a team of NASA doctors decided blood thinners would be the best course of treatment for the astronaut. They were limited in their pharmaceutical options, however. The ISS keeps only a small supply of various medicines on board, and there was a limited amount of the blood thinner Enoxaparin (Lovenox®) available. Moll advised NASA on what dosage of Enoxaparin would effectively treat the DVT while also lasting long enough, until NASA could get a new shipment of drugs — which Moll helped select — to the ISS.

The course of treatment with Enoxaparin — a drug delivered by an injection into the skin — lasted for around 40 days. On day 43 of the astronaut’s treatment, a supply of Apixaban (Eliquis®) — a pill taken orally- was delivered to the ISS by a supply spacecraft.

Throughout the treatment process, which lasted more than 90 days, the astronaut performed ultrasounds on their own neck with guidance from a radiology team on Earth in order to monitor the blood clot. Moll was also able to speak to the astronaut during this period through email and phone calls.

“When the astronaut called my home phone, my wife answered and then passed the phone to me with the comment, ‘Stephan, a phone call for you from space.’ That was pretty amazing,” said Moll. “It was incredible to get a call from an astronaut in space. They just wanted to talk to me as if they were one of my other patients. And amazingly the call connection was better than when I call my family in Germany, even though the ISS zips around Earth at 17,000 miles per hour.”

Four days before the astronaut’s journey home to Earth, they stopped taking Apixaban. Moll and his NASA counterparts made that decision because of how physically demanding and potentially dangerous the re-entry process can be for astronauts, and they did not want an injury to be exacerbated by the use of blood thinners. The astronaut landed safely on Earth and the blood clot required no more treatment.

This astronaut’s blood clot was asymptomatic — they didn’t have any symptoms that would have otherwise made them aware of the clot. The DVT was discovered when the astronaut was taking ultrasounds of their neck for a research study on how body fluid is redistributed in zero gravity. If it wasn’t for the study, there’s no telling what the outcome could have been. That’s why Moll continues to work with NASA and says there’s a need for more research of how blood and blood clots behave in space.

“Is this something that is more common in space?” posed Moll. “How do you minimize risk for DVT? Should there be more medications for it kept on the ISS? All of these questions need answering, especially with the plan that astronauts will embark on longer missions to the moon and Mars.”

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A new study by researchers from University of Helsinki and Lund University shows that northern Arctic regions remain under-sampled and provides detailed maps of potential new sampling locations for each environmental science discipline across the Arctic.

The changing Arctic requires a sampling strategy for the future

Doing field work in the harsh Arctic conditions is not easy. Resources and accessibility strongly constrain Arctic research. Understanding what kind of conditions and regions remain under-studied is important when researchers plan new field campaigns.

However, studies dealing with the representativeness of sampling have been conducted mainly for very specific fields, or in smaller regions. Thus, the current state of field sampling across broad environmental science disciplines across the Arctic has not been fully understood.

“We utilize an existing literature database of around 1 800 field studies across the Arctic,” says Dan Metcalfe, a senior lecturer in Lund University. This database contains information about the field sampling locations and citations, including their primary discipline/s within environmental sciences featured in the article.

Open spatial data sets describing topography, vegetation, and soils were used to characterize the environmental conditions of each sampling location. “The availability of these data sets has increased during the past decade which allows us to explore the environmental coverage of Arctic field sampling comprehensively,” says a Post-Doc researcher Hakim Abdi from Lund University.

New field studies are needed in the northernmost Arctic regions

The study shows that more research is needed particularly in the Canadian Arctic Archipelago, northern Greenland, northern Taimyr, and central and eastern Siberia. These under-sampled regions are characterized by cold soils and climate and modest vegetation cover. Many of these regions are predicted to experience rapid permafrost thaw and vegetation shifts due to global warming in the future. The lack of data from these conditions suggests that we do not necessarily understand the whole range of changes that the global warming might cause.

Differences in sampling across environmental science disciplines

There are differences in the representativeness of sampling locations across environmental science disciplines. Sampling locations in Botany and Biogeochemistry cover environmental gradients the best, and Microbiology, Meteorology, Geosciences and Geographic Information Systems / Remote Sensing / Modeling have the largest research gaps across the Arctic. Although northern Alaska and Fennoscandia remained the best sampled regions, research gaps were found even in central Arctic Alaska or southern Arctic Fennoscandia in some disciplines.

Let’s keep exploring the Arctic together

Luckily, many of these under-sampled regions are close to existing infrastructure, so making a change is possible. “We hope these results will help prioritize future research efforts across all environmental science disciplines, thus increasing our knowledge about the Arctic environmental change,” summarizes Professor Miska Luoto from University of Helsinki.

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Materials provided by University of Helsinki. Original written by Riitta-Leena Inki. Note: Content may be edited for style and length.

“Scientists should be looking at the entire brain to understand specific types of learning,” says Richard Huganir, Ph.D., Bloomberg Distinguished Professor and Director of the Solomon H. Snyder Department of Neuroscience at the Johns Hopkins University School of Medicine. “Different parts of the brain contribute to learning in different ways, and studying brain cell receptors can help us decipher how this works.”

The work, say the researchers, may ultimately inform efforts to develop treatments for learning-based and neurocognitive disorders.

In a report on the work, appearing online Dec. 31 in Neuron, Huganir and his research team say they focused on AMPA-type glutamate receptors, or AMPARs, key molecules that help send messages between brain cells called neurons. AMPARs function like antennas that form along the surface of a particular spot on neurons called a synapse, where it receives molecular signals from other neurons.

To monitor and measure AMPAR levels in mouse brains, scientists previously had to dissect the organ before and after a learning experiment and compare differences. Now, scientists have ways to directly view the brain during learning, recording thousands of synapses at a time.

In the new experiments, scientists injected DNA-encoding AMPARs carrying a fluorescent tag into the brains of mice, and used an electrical pulse to get neurons to absorb the AMPAR DNA. Next, with a tool called two-photon microscopy, the scientists used a laser — essentially an intensely focused beam of light — to detect and measure the amount of fluorescence coming from the tagged AMPARs.

More fluorescence is an indication of increased AMPAR activity and messaging between neurons, a good sign that learning and memory building is taking place in those neurons, Huganir says.

To “see” what learning looked like in the test animals’ neurons, Huganir’s team trained mice to reach for and grab a food pellet placed just outside their cage using their paws. Normally, mice get pellets with their mouths.

While the mice were learning how to reach for the pellet, the scientists found an approximately 20% increase in the activity of AMPARs in an area of the brain known as the motor cortex, which is known for controlling and precisely moving muscles. On neurons, the AMPARs look like lights on a Christmas tree and glow brighter with increasing activity.

But the experiments also showed the same increase in AMPAR activity levels in the visual cortex too.

“This made sense because vision is very important for motor control,” says Richard Roth, Ph.D., currently a postdoctoral fellow at Stanford University, but who performed experiments for this study as a graduate student in Huganir’s laboratory.

“So, we did the same experiment again, but with the lights switched off,” says Roth.

Using infrared light, which the mice couldn’t see, the mice eventually learned to successfully grab the food, but there was a smaller increase (10%) in the activity of AMPARs in the visual cortex.

“We believe the mice brains are using different sets of sensory cues in the dark to learn the motor task, including touch and smell, enabling these other senses to take over,” says Roth.

Next, the research team repeated the experiments using specialized light-activated modulators to shut down neurons in either the motor or visual cortex.

If the mice were trained to get the pellet with the room lights on, the mice could not complete the task if their visual cortex was shut down. “Clearly, these mice relied on learning centralized in their visual cortex to reach the pellet,” says Roth.

However, mice initially trained to grab the pellet in the dark could still complete the task, even if their visual cortex was shut down.

“We’ve traditionally thought that motor-based learning happens solely in the motor part of the brain, but our studies and others now show that it’s not as specific as we had thought. There is more of a brainwide effect in learning,” says Roth.

Huganir notes that among the genes that control neuronal receptors involved in learning is SYNGAP. His and others’ research has shown that when the gene is mutated, it contributes to conditions including intellectual disability, autism and schizophrenia — all conditions marked in part by disrupted thinking and learning.

Sustainability scientists have developed systematic and comprehensive assessment methods and performed the first assessment of a country’s progress in achieving all 17 UN Sustainable Development Goals (SDGs) not just as a nation, but also at the regional levels, and not just as a snapshot — but over time.

In “Assessing progress towards sustainable development over space and time” in this week’s Nature, scientists from Michigan State University (MSU) and in China show that indeed all sustainability, like politics, is local.

Even as a country can overall claim movement toward a sustainable future, areas within the country reflect the gains and losses in the struggle with poverty, inequality, climate, environmental degradation and for prosperity, and peace and justice. Most striking, the study found, is the disparities between developed regions and ones that are developing.

“We have learned that sustainability’s progress is dynamic and that sometimes gains in one important area can come at costs to another area, tradeoffs that can be difficult to understand but can ultimately hobble progress,” said Jianguo “Jack” Liu, MSU Rachel Carson Chair in Sustainability and senior author. “Whether it’s protecting precious natural resources, making positive economic change or reducing inequality — it isn’t a static score. We must carefully take a holistic view to be sure progress in one area isn’t compromised by setbacks in other areas.”

The group assessed China with methods that can be applied to other countries. China’s vast size and sweeping socioeconomic changes at national and provincial levels showed how progress in sustainability can shift. Between 2000 and 2015, China has improved its aggregated SDG score.

At the provincial level, however, there is a disparity between the country’s developed and developing regions. East China — which is home to the country’s economic boom — had a higher SDG Index score than the more rural west China in the 2000s. In 2015, south China had a higher SDG Index score than the industrialized and agricultural-intensive north China.

Zhenci Xu, a recent PhD graduate from MSU’s Center for Systems Integration and Sustainability (MSU-CSIS) who led the study, notes that countries are tasked with urgent goal of achieving sustainability even as populations grow, economies develop unevenly, natural resources like water and energy become scarce, land degrades, and income and gender inequities intensify.

Developed provinces had higher (and thus better) SDG Index scores than developing provinces throughout the study period of 2000-2015. But the average SDG Index scores in developing provinces were increasing faster compared to developed provinces.

“China’s eastern region began developing during the reform and opening-up policy in the late 70s to spur economic development along the coasts, which was accompanied by better social services,” Xu said. “In 1999, China started to address the rural western parts which had lagged in progress. That saw improvements both in infrastructure and ecological conservation, which seems to have boosted their sustainable development. The eastern parts have begun to struggle with the consequences of rapid economic growth — such as pollution and inequities.”

The authors note that overall sustainability is advancing thanks to better education, healthcare and environmental conservation policies. The study points out that even amidst progress, it is important to scrutinize what is happening at regional levels to know where to direct resources and attention.

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Materials provided by Michigan State University. Note: Content may be edited for style and length.