Dr. Zihao Ou, assistant professor of physics at The University of Texas at Dallas, is lead author of the study, published in the Sept. 6 print issue of the journal Science.

Living skin is a scattering medium. Like fog, it scatters light, which is why it cannot be seen through.

“We combined the yellow dye, which is a molecule that absorbs most light, especially blue and ultraviolet light, with skin, which is a scattering medium. Individually, these two things block most light from getting through them. But when we put them together, we were able to achieve transparency of the mouse skin,” said Ou, who, with colleagues, conducted the study while he was a postdoctoral researcher at Stanford University before joining the UT Dallas faculty in the School of Natural Sciences and Mathematics in August.

“For those who understand the fundamental physics behind this, it makes sense; but if you aren’t familiar with it, it looks like a magic trick,” Ou said.

The “magic” happens because dissolving the light-absorbing molecules in water changes the solution’s refractive index — a measure of the way a substance bends light — in a way that matches the refractive index of tissue components like lipids. In essence, the dye molecules reduce the degree to which light scatters in the skin tissue, like dissipating a fog bank.

In their experiments with mice, the researchers rubbed the water and dye solution onto the skin of the animals’ skulls and abdomens. Once the dye had completely diffused into the skin, the skin became transparent. The process is reversible by washing off any remaining dye. The dye that has diffused into the skin is metabolized and excreted through urine.

“It takes a few minutes for the transparency to appear,” Ou said. “It’s similar to the way a facial cream or mask works: The time needed depends on how fast the molecules diffuse into the skin.”

Through the transparent skin of the skull, researchers directly observed blood vessels on the surface of the brain. In the abdomen, they observed internal organs and peristalsis, the muscle contractions that move contents through the digestive tract.

The transparent areas take on an orangish color, Ou said. The dye used in the solution is commonly known as FD&C Yellow #5 and is frequently used in orange- or yellow-colored snack chips, candy coating and other foods. The Food and Drug Administration certifies nine color additives — tartrazine is one — for use in foods.

“It’s important that the dye is biocompatible — it’s safe for living organisms,” Ou said. “In addition, it’s very inexpensive and efficient; we don’t need very much of it to work.”

The researchers have not yet tested the process on humans, whose skin is about 10 times thicker than a mouse’s. At this time it is not clear what dosage of the dye or delivery method would be necessary to penetrate the entire thickness, Ou said.

“In human medicine, we currently have ultrasound to look deeper inside the living body,” Ou said. “Many medical diagnosis platforms are very expensive and inaccessible to a broad audience, but platforms based on our tech should not be.”

Ou said one of the first applications of the technique will likely be to improve existing research methods in optical imaging.

“Our research group is mostly academics, so one of the first things we thought of when we saw the results of our experiments was how this might improve biomedical research,” he said. “Optical equipment, like the microscope, is not directly used to study live humans or animals because light can’t go through living tissue. But now that we can make tissue transparent, it will allow us to look at more detailed dynamics. It will completely revolutionize existing optical research in biology.”

In his new Dynamic Bio-imaging Lab at UTD, Ou will continue the research he started with Dr. Guosong Hong, assistant professor of materials science and engineering at Stanford and a corresponding author of the study. Ou said the next steps in the research will include understanding what dosage of the dye molecule might work best in human tissue. In addition, the researchers are experimenting with other molecules, including engineered materials, that could perform more efficiently than tartrazine.

Study authors from Stanford, including co-corresponding author Dr. Mark Brongersma, the Stephen Harris Professor in the Department of Materials Science and Engineering, were funded by grants from federal agencies including the National Institutes of Health, the National Science Foundation and the Air Force Office of Scientific Research. As an interdisciplinary postdoctoral scholar, Ou was supported by the Wu Tsai Neuroscience Institute at Stanford. The researchers have applied for a patent on the technology.

“Bats have gained a bad reputation as being something to fear, especially after reports of a possible linkage with the origins Covid-19,” says study author Eyal Frank, an assistant professor at the Harris School of Public Policy. “But bats do add value to society in their role as natural pesticides, and this study shows that their decline can be harmful to humans.”

Frank compared the effect of bat die-offs on pesticide use in counties that experienced those bat population declines to counties that were likely unaffected by the wildlife disease. He found that when the bat populations declined, farmers increased their use of pesticides by about 31 percent. Because pesticides have been linked to negative health impacts, Frank next tested to see if the increased use of pesticides corresponded with an increase in infant mortality — a common marker to study the health impacts of environmental pollution. Indeed, when farmers increased their use of pesticides, the infant mortality rate rose by almost 8 percent. This corresponds to an additional 1,334 infant deaths. Or, for every 1 percent increase in pesticides, there was a 0.25 percent increase in the infant mortality rate.

The study also found that pesticides aren’t as good at preventing pests as bats. The quality of the crops likely declined, as farmers’ revenue from crop sales decreased by nearly 29 percent. Combining this revenue loss with the expense of the pesticides, farmers in communities that experienced the bat die-offs lost $26.9 billion dollars between 2006 and 2017. Adding onto those losses the $12.4 billion in damages from infant mortality, the total societal cost from the bat die-offs in these communities amounted to $39.6 billion.

“When bats are no longer there to do their job in controlling insects, the costs to society are very large — but the cost of conserving bat populations is likely smaller,” says Frank. “More broadly, this study shows that wildlife adds value to society, and we need to better understand that value in order to inform policies to protect them.”

A team of data scientists at eBird, the participatory science platform, has packaged summaries covering every bird species, in every state, and made them available online for free. These data summaries will help states prepare their federally required 2025 updates to State Wildlife Action Plans.

“As we began to work more closely with state agencies and regional conservation partnerships, we realized that we needed to significantly increase the accessibility of eBird information for these partners,” said Viviana Ruiz-Gutierrez, assistant director of the Cornell Lab’s Center for Avian Population Studies and the driving force behind development of the state summaries.

“By providing these customized summaries, state agencies don’t have to wrangle with big data and spatial tools. They get data targeted to the area they are responsible for,” said Andrew Stillman, a postdoctoral fellow at the Cornell Lab. “It’s much more efficient, saving them time and money.”

State Wildlife Action Plans are critical to conservation in the United States, Stillman said. The plans must be updated every 10 years and submitted to the U.S. Fish and Wildlife Service for approval. Approval releases funding from the State and Tribal Wildlife Grants program, which is used to proactively conserve birds and other species that make up the biodiversity of each state.

The 2025 updates will mark the second major revision to state wildlife plans since the first plans were completed in 2005. But this is the first time eBird state data summaries will be available to inform the revisions, helping planners easily identify which species are in greatest need of conservation and to set priorities for where and when to take conservation action.

Without year-round weekly bird abundance data from eBird, an important part of the big picture is missing. For example, tundra swans don’t breed in Michigan and are not found there for most of the year. But during two weeks in March, 13% of the global population is migrating through Michigan, making marsh and wetland habitat vital for stopovers during their long journey back to their Arctic breeding grounds.

The state summaries are updated each year with new population numbers from eBird. With the latest August 2024 update, planners can now also see which way bird populations are trending for the entire state: increasing, decreasing or stable; and by how much.

“We’ll continue to refine and update the summaries so states have what they need,” Stillman said. “We’re also looking into expanding this customization for the two dozen Migratory Bird Joint Ventures in the U.S. and Canada. Birds are not known for recognizing human boundaries and joint venture partnerships work across boundaries to conserve birds and the habitats they need, where they need it. The state planners tell us, ‘Keep it coming.'”

In creating a pair of new robots, Cornell University researchers cultivated an unlikely component, one found on the forest floor: fungal mycelia. By harnessing mycelia’s innate electrical signals, the researchers discovered a new way of controlling “biohybrid” robots that can potentially react to their environment better than their purely synthetic counterparts.

The team’s paper published in Science Robotics. The lead author is Anand Mishra, a research associate in the Organic Robotics Lab led by Rob Shepherd, professor of mechanical and aerospace engineering at Cornell University, and the paper’s senior author.

“This paper is the first of many that will use the fungal kingdom to provide environmental sensing and command signals to robots to improve their levels of autonomy,” Shepherd said. “By growing mycelium into the electronics of a robot, we were able to allow the biohybrid machine to sense and respond to the environment. In this case we used light as the input, but in the future it will be chemical. The potential for future robots could be to sense soil chemistry in row crops and decide when to add more fertilizer, for example, perhaps mitigating downstream effects of agriculture like harmful algal blooms.”

Mycelia are the underground vegetative part of mushrooms. They have the ability to sense chemical and biological signals and respond to multiple inputs.

“Living systems respond to touch, they respond to light, they respond to heat, they respond to even some unknowns, like signals,” Mishra said. “If you wanted to build future robots, how can they work in an unexpected environment? We can leverage these living systems, and any unknown input comes in, the robot will respond to that.”

Two biohybrid robots were built: a soft robot shaped like a spider and a wheeled bot.

The robots completed three experiments. In the first, the robots walked and rolled, respectively, as a response to the natural continuous spikes in the mycelia’s signal. Then the researchers stimulated the robots with ultraviolet light, which caused them to change their gaits, demonstrating mycelia’s ability to react to their environment. In the third scenario, the researchers were able to override the mycelia’s native signal entirely.

The research was supported by the National Science Foundation (NSF) CROPPS Science and Technology Center; the U.S. Department of Agriculture’s National Institute of Food and Agriculture; and the NSF Signal in Soil program.

In a study published on July 31 in the journal Earth’s Future, scientists, including researchers at the University of Colorado Boulder, revealed how heat waves, especially those occurring in Antarctica’s cold seasons, may impact the animals living there. The research illustrates how extreme weather events intensified by climate change could have profound implications for the continent’s fragile ecosystems.

In March 2022, the most intense heat wave ever recorded on Earth hit Antarctica, just as organisms in the southern region braced themselves for the long, harsh winter ahead. The extreme weather raised temperatures in parts of Antarctica to more than 70°F above average, melting glaciers and snow even in the McMurdo Dry Valleys, one of the planet’s coldest and driest regions.

As part of a Long-Term Ecological Research (LTER) project in Antarctica, the research team found that the unexpected melt followed by a rapid refreeze likely disrupted the life cycles of many organisms and killed a large swath of some invertebrates in the McMurdo Dry Valleys.

“It’s important that we pay attention to these signals, even if they’re coming from microscopic organisms in soils in a polar desert,” said Michael Gooseff, the paper’s senior author and professor in the Department of Civil, Environment and Architectural Engineering at CU Boulder. “They’re the early responders to changes that could cascade up to larger organisms, the landscape and even us, far away from Antarctica.”

When Gooseff arrived in Antarctica in November 2021, the continent looked much like it had for the past two decades. As a fellow of the Institute of Arctic and Alpine Research (INSTAAR), Gooseff has led the LTER at the McMurdo Dry Valleys, a National Science Foundation-funded project, for the past decade. Nearly every Antarctic summer, he travels to the southern region to study its ecosystem and how organisms survive in extreme environmental conditions.

While most animals can’t tolerate the region’s dryness and cold, some microbes and invertebrates, including roundworms and water bears, thrive in this frozen desert. Water bears, or tardigrades, are tiny, eight-legged animals measuring 0.002 to 0.05 inches long. They can survive extreme conditions — as cold as -328°F and as hot as 300 °F — that would kill most other forms of life.

In 2022, all members of the polar expedition team left the continent in February, before the Antarctic summer ended. A month later, Antarctica experienced the most extreme heat wave on record, driven by an intense storm known as an atmospheric river, which transported moist air over long distances to the polar region.

The team’s sensors in the McMurdo Dry Valleys recorded air temperatures, which typically hover around -4°F in March, rising above freezing and exceeding the average by 45°F.

Satellite imagery and stream discharge measurements showed that the sudden warming wetted the valleys’ soil more than two months after the peak summer thaw, at a time when the land is typically dry.

In two days, after the heat wave passed, temperatures plummeted and the soil froze. This event happened during a critical transition period, when organisms hunker down and get ready for the dark, cold winter. Gooseff and his colleagues were curious about how animals in the valleys responded.

“These animals invest a significant amount of energy in preparing and shutting down for the winter,” said Gooseff. “When things start to warm up the following summer, they use energy to become active again. One of our major concerns with unusual weather events like this heat wave is that these animals might start using a lot more energy, thinking it’s summer, only to have to shut down again two days later. How many times can they go through that cycle before they exhaust their energy reserves?”

He and the team returned to Antarctica the following summer, in December 2022. They sampled the soil and compared organisms living in areas that became wet to those that stayed dry during the heat wave.

They observed a 50% decrease in the population of Scottnema, a common roundworm, in areas that got wet. Scottnema is adapted to extremely cold and dry climates.

“The heat wave made the environment appear warm enough for things to get wet, creating a false start to summer. Some of the biology responding to these temperatures might be seriously disrupted by this,” Gooseff said.

Rapid swings between extremes in weather can disproportionately impact sensitive species like Scottnema, but they may have far less impact on other animals, such as tardigrades. These creatures have a higher tolerance for moisture, allowing them to proliferate as the environment becomes wetter.

“Changes in which species are in the soil and how big the populations are can have a major impact on the ecosystem’s food web and nutrient cycling,” Gooseff said.

Previous research has shown Scottnema is responsible for about 10% of the carbon processed in the Dry Valleys’ soil ecosystem.

As climate change exacerbates extreme weather events in Antarctica, larger species are also being impacted. For example, in the summer of 2013, an unusual rainfall event along the Adélie Coast of East Antarctica killed all Adélie penguin chicks in the region. In July, temperatures in parts of East Antarctica climbed up to 50 °F above the usual winter average.

Gooseff and his team plan to continue documenting extreme weather events and their impacts on the Antarctic ecosystem.

What happens in Antarctica doesn’t stay in Antarctica, Gooseff said.

“The loss of ice shelves has pretty dramatic impacts on the mass balance of our oceans, and it affects us even thousands of miles away.”

“We know of only three or four occurrences of similar gravitational lens configurations in the observable universe, which makes this find exciting, as it demonstrates the power of Webb and suggests maybe now we will find more of these,” said astronomer Guillaume Desprez of Saint Mary’s University in Halifax, Nova Scotia, a member of the team presenting the Webb results.

While this region has been observed previously with NASA’s Hubble Space Telescope, the dusty red galaxy that forms the intriguing question-mark shape only came into view with Webb. This is a result of the wavelengths of light that Hubble detects getting trapped in cosmic dust, while longer wavelengths of infrared light are able to pass through and be detected by Webb’s instruments.

Astronomers used both telescopes to observe the galaxy cluster MACS-J0417.5-1154, which acts like a magnifying glass because the cluster is so massive it warps the fabric of space-time. This allows astronomers to see enhanced detail in much more distant galaxies behind the cluster. However, the same gravitational effects that magnify the galaxies also cause distortion, resulting in galaxies that appear smeared across the sky in arcs and even appear multiple times. These optical illusions in space are called gravitational lensing.

The red galaxy revealed by Webb, along with a spiral galaxy it is interacting with that was previously detected by Hubble, are being magnified and distorted in an unusual way, which requires a particular, rare alignment between the distant galaxies, the lens, and the observer — something astronomers call a hyperbolic umbilic gravitational lens. This accounts for the five images of the galaxy pair seen in Webb’s image, four of which trace the top of the question mark. The dot of the question mark is an unrelated galaxy that happens to be in the right place and space-time, from our perspective.

In addition to producing a case study of the Webb NIRISS (Near-Infrared Imager and Slitless Spectrograph) instrument’s ability to detect star formation locations within a galaxy billions of light-years away, the research team also couldn’t resist highlighting the question mark shape. “This is just cool looking. Amazing images like this are why I got into astronomy when I was young,” said astronomer Marcin Sawicki of Saint Mary’s University, one of the lead researchers on the team.

“Knowing when, where, and how star formation occurs within galaxies is crucial to understanding how galaxies have evolved over the history of the universe,” said astronomer Vicente Estrada-Carpenter of Saint Mary’s University, who used both Hubble’s ultraviolet and Webb’s infrared data to show where new stars are forming in the galaxies. The results show that star formation is widespread in both. The spectral data also confirmed that the newfound dusty galaxy is located at the same distance as the face-on spiral galaxy, and they are likely beginning to interact.

“Both galaxies in the Question Mark Pair show active star formation in several compact regions, likely a result of gas from the two galaxies colliding,” said Estrada-Carpenter. “However, neither galaxy’s shape appears too disrupted, so we are probably seeing the beginning of their interaction with each other.”

“These galaxies, seen billions of years ago when star formation was at its peak, are similar to the mass that the Milky Way galaxy would have been at that time. Webb is allowing us to study what the teenage years of our own galaxy would have been like,” said Sawicki.

The Webb images and spectra in this research came from the Canadian NIRISS Unbiased Cluster Survey (CANUCS). The research paper is published in the Monthly Notices of the Royal Astronomical Society.