A new study now shows that Saturn — though much blander and less colorful than Jupiter — also has long-lasting megastorms with impacts deep in the atmosphere that persist for centuries.

The study was conducted by astronomers from the University of California, Berkeley, and the University of Michigan, Ann Arbor, who looked at radio emissions from the planet, which come from below the surface, and found long-term disruptions in the distribution of ammonia gas.

The study was published today (Aug. 11) in the journal Science Advances.

Megastorms occur approximately every 20 to 30 years on Saturn and are similar to hurricanes on Earth, although significantly larger. But unlike Earth’s hurricanes, no one knows what causes megastorms in Saturn’s atmosphere, which is composed mainly of hydrogen and helium with traces of methane, water and ammonia.

“Understanding the mechanisms of the largest storms in the solar system puts the theory of hurricanes into a broader cosmic context, challenging our current knowledge and pushing the boundaries of terrestrial meteorology,” said lead author Cheng Li, a former 51 Peg b Fellow at UC Berkeley who is now an assistant professor at the University of Michigan.

Imke de Pater, a UC Berkeley professor emerita of astronomy and of earth and planetary sciences, has been studying gas giants for over four decades to better understand their composition and what makes them unique, employing the Karl G. Jansky Very Large Array in New Mexico to probe the radio emissions from deep inside the planet.

“At radio wavelengths, we probe below the visible cloud layers on giant planets. Since chemical reactions and dynamics will alter the composition of a planet’s atmosphere, observations below these cloud layers are required to constrain the planet’s true atmospheric composition, a key parameter for planet formation models,” she said. “Radio observations help characterize dynamical, physical and chemical processes including heat transport, cloud formation and convection in the atmospheres of giant planets on both global and local scales.”

As reported in the new study, de Pater, Li and UC Berkeley graduate student Chris Moeckel found something surprising in the radio emissions from the planet: anomalies in the concentration of ammonia gas in the atmosphere, which they connected to the past occurrences of megastorms in the planet’s northern hemisphere.

According to the team, the concentration of ammonia is lower at midaltitudes, just below the uppermost ammonia-ice cloud layer, but has become enriched at lower altitudes, 100 to 200 kilometers deeper in the atmosphere. They believe that the ammonia is being transported from the upper to the lower atmosphere via the processes of precipitation and reevaporation. What’s more, that effect can last for hundreds of years.

The study further revealed that although both Saturn and Jupiter are made of hydrogen gas, the two gas giants are remarkably dissimilar. While Jupiter does have tropospheric anomalies, they have been tied to its zones (whitish bands) and belts (darkish bands) and are not caused by storms like they are on Saturn. The considerable difference between these neighboring gas giants is challenging what scientists know about the formation of megastorms on gas giants and other planets and may inform how they’re found and studied on exoplanets in the future.

The National Radio Astronomy Observatory (NRAO) is a facility of the National Science Foundation, operated under cooperative agreement by Associated Universities Inc.

The MOMI-VAX study launched in June 2021 when data on COVID-19 vaccination in pregnant people were sparse. Researchers hoped to understand the immune response following receipt of Pfizer and Moderna COVID-19 vaccines, and determine how much protection against illness they provided. Pregnant people are more likely to be hospitalized and die from severe COVID-19, and the disease puts them at greater risk for preterm birth. Researchers also suspected that, as with other vaccines, the antibodies generated by COVID-19 vaccination might transfer to fetuses across the placenta, which would provide newborns with some additional protection against COVID-19 in their first months of life. Among other metrics, the study tracked the COVID-19 antibody levels of pregnant people who received either of the two COVID-19 vaccines, as well as the antibodies in their cord blood when they gave birth.

Researchers at the NIAID-funded Infectious Diseases Clinical Research Consortium (IDCRC) followed more than 500 pregnant volunteers and their newborns, at nine study sites. Results from 240 participants are reported in this paper, including 167 pregnant participants who received the two-dose primary series of either of the two mRNA vaccines during pregnancy, and 73 who received a booster dose; at the time, only one booster dose was recommended. Researchers examined blood samples taken before and after participants were vaccinated or boosted, and at time of delivery. The researchers also analyzed participants’ cord blood at the time of birth.

The researchers found that pregnant people who received the COVID-19 vaccines generated antibodies against specific types of SARS-CoV-2. These included antibodies against the D614G variant (which the vaccines were designed to protect against), as well as the Delta and Omicron subvariants. The antibodies effectively crossed the placenta and were also found in the cord blood of vaccinated participants. This likely conferred some protection in the newborns against these variants immediately after birth — a critical time when they are vulnerable to severe COVID-19 disease but are too young to be vaccinated, according to the researchers.

Pregnant participants who received a booster dose had substantially more antibodies against SARS-CoV-2, both in their own blood and in their cord blood, suggesting that boosting also increased their newborns’ immune defenses against COVID-19. These findings support the use of COVID-19 vaccination, and in particular booster doses, during pregnancy for protection of mothers and newborns.

The researchers suggest that future studies could determine the best time during pregnancy to get vaccinated against COVID-19 to provide the most protection for parent and newborn. In addition, researchers hope to build a more complete picture of how prenatal COVID-19 vaccination affects infants using more data collected during the MOMI-VAX study, such as antibody levels in breastmilk and infants’ SARS-CoV-2 antibody levels in the year after birth.

University of Chicago Prof. Jiwoong Park, however, wondered what would happen if you made even thinner and flatter strands — in effect, so thin that they’re actually 2D instead of 3D. What would happen to the light?

Through a series of innovative experiments, he and his team found that a sheet of glass crystal just a few atoms thick could trap and carry light. Not only that, but it was surprisingly efficient and could travel relatively long distances — up to a centimeter, which is very far in the world of light-based computing.

The research, published Aug. 10 in Science, demonstrates what are essentially 2D photonic circuits, and could open paths to new technology.

“We were utterly surprised by how powerful this super-thin crystal is; not only can it hold energy, but deliver it a thousand times further than anyone has seen in similar systems,” said lead study author Jiwoong Park, a professor and chair of chemistry and faculty member of the James Franck Institute and Pritzker School of Molecular Engineering. “The trapped light also behaved like it is traveling in a 2D space.”

Guiding light

The newly invented system is a way to guide light — known as a waveguide — that is essentially two-dimensional. In tests, the researchers found they could use extremely tiny prisms, lenses, and switches to guide the path of the light along a chip — all the ingredients for circuits and computations.

Photonic circuits already exist, but they are much larger and three-dimensional. Crucially, in existing waveguides, the particles of light — called photons — always travel enclosed inside the waveguide.

With this system, the scientists explained, the glass crystal is actually thinner than the photon itself — so part of the photon actually sticks out of the crystal as it travels.

It’s a bit like the difference between building a tube to send suitcases around an airport, versus setting them on top of a conveyer belt. With a conveyer belt, the suitcases are open to the air and you can easily see and adjust them en route. This approach makes it much easier to build intricate devices with the glass crystals, as the light can be easily moved with lenses or prisms.

The photons can also experience information about the conditions along the way. Think of checking the suitcases coming in from outdoors to see if it’s snowing outside. Similarly, the scientists can imagine using these waveguides to make sensors at the microscopic level.

“For example, say you had a sample of liquid, and you wanted to sense whether a particular molecule was present,” explained Park. “You could design it so that this waveguide travels through the sample, and the presence of that molecule would change how the light behaves.”

The scientists are also interested in building very thin photonic circuits which could be stacked to integrate many more tiny devices into the same chip area. The glass crystal they used in these experiments was molybdenum disulfide, but the principles should work for other materials.

Though theoretical scientists had predicted that this behavior should exist, actually realizing it in the laboratory was a years-long journey, the scientists said.

“It was a really challenging but satisfying problem, because we were walking into a completely new field. So everything we needed we had to devise ourselves — from growing the material to measuring how the light was moving,” said graduate student Hanyu Hong, the co-first author of the paper.

Myungjae Lee (formerly a postdoctoral researcher at UChicago, now faculty at Seoul National University) was the other first co-author of the paper. Postdoctoral researcher Jaehyung Yu, Fauzia Mujid (PhD’22, now at Ecolab), and graduate students Andrew Ye and Ce Liang were also authors on the paper.

The scientists used the University of Chicago Materials Research Science and Engineering Center, the fabrication facilities of the Pritzker Nanofabrication Facility, and the Cornell Center for Materials Research.

Wastewater treatment plants are an indispensable part of our modern infrastructure; they have made a significant contribution to improving the quality of our surface waters. However, their ability to completely remove what are known as micropollutants from wastewater is mostly limited. These substances include, for example, active ingredients from pharmaceuticals and personal care products, pesticides and other synthetic substances enter waterbodies via the treated wastewater, placing an additional burden on rivers and streams. This exacerbates the challenges faced by already vulnerable insect communities and aquatic fauna. Previous studies — which have primarily focused on single wastewater treatment plants — have already shown that invertebrate communities downstream of such effluents are generally dominated by pollution-tolerant taxa.

Until now, however, it was unclear how ubiquitous these changes are. That is why a team of biologists from Goethe University Frankfurt has now studied extensively how wastewater from 170 wastewater treatment plants in Hesse has an impact on the species composition of invertebrates. This has prompted a change in the common conception that human-induced stressors reduce the number of species in a habitat and thus their diversity: Rather, the findings indicate that a shift in species composition can be observed. The researchers were able to identify significant shifts in the composition of the species community between sites located upstream and downstream of wastewater treatment plants. Some species were particularly affected by effluents from wastewater treatment plants — such as stonefly and caddisfly larvae, which disappear entirely in some places. Other taxa, such as certain worms and crustaceans, by contrast, benefit and are found in greater numbers. This change can be observed especially in streams and smaller rivers. Overall, wastewater treatment plants alter conditions downstream to the advantage of pollution-tolerant taxa and to the disadvantage of sensitive ones.

How can we reduce water pollution?

Modern treatment techniques such as ozonation or activated charcoal filtering can make water treatment in wastewater treatment plants more efficient, allowing a wider range of pollutants, including many trace substances, to be removed from the wastewater before it is released into the environment. Merging smaller wastewater treatment plants can also contribute to reducing the burden on the environment. Whatever measures are taken, it is important to make sure that upstream sections are not already degraded and are in a good chemical and structural condition.

Spacing out samples over time in a stratified sampling pattern is better at catching risky pathogens like Cronobacter than randomly sampling from the product as it is being produced, the researchers found. Furthermore, while taking more samples of product generally increases the chance to catch the pathogen, there is a point after which it is unlikely to increase safety.

“Our findings show that existing sampling and testing guidance is powerful, at least for the one hazard profile our team had access to for the study,” said project lead Matthew J. Stasiewicz, associate professor in the Department of Food Science and Human Nutrition (FSHN), part of the College of Agricultural, Consumer and Environmental Sciences at U. of I.

“However, this work also highlights the need for additional research and data sharing efforts into patterns of contamination in infant formula production, so that sampling and testing can be better matched to current needs,” he stated.

Safety systems for infant formula production include control points like milk pasteurization and steps to prevent contamination such as sanitary facility design and regular cleaning and sanitation. Product testing is an additional tool that producers are using to verify safety, and it must be powerful enough to catch a major failure before a potentially risky product is released to customers.

The study, published in the Journal of Food Protection, was supported by the Institute for the Advancement of Food and Nutrition Sciences (IAFNS) Food Microbiology Committee. The researchers used computer models to simulate sampling and testing finished formula to gauge the power of current national and international guidelines for testing programs and suggest ways to do better.

The process was based on detecting a realistic hazard, defined by what was observed in samples from Cronobacter-contaminated batches produced in Europe in the 2010s, the most current data available. The researchers found that safety plans with 30 or more grab samples had a very high probability of detecting hazards. However, there was a point of diminishing returns, where very high sample numbers — like testing every can produced — would not be meaningfully more powerful. They concluded that systematic or stratified random sampling patterns are more effective than simple random sampling for bulk powder testing.

“In addition to analyzing relevant scenarios, we built a web app that allows industry stakeholders to simulate various sampling scenarios and gain a deeper understanding of the effectiveness of sampling plans specific to their plants. With this knowledge, producers can proactively address risks and optimize current sampling practices,” said the study’s lead author Minho Kim, a doctoral student in FSHN.

For parents who are concerned about their infants becoming ill from bacterial contamination of formula, the researchers advise they talk to their doctor about safer formula feeding.

For example, one way to further reduce bacteria in formula is using hot water during reconstitution and then cooling it to body temperature prior to feeding. This simple preventative measure can greatly reduce the risk from Cronobacter contamination according to an international risk assessment. However, steps like this require care to avoid the risk of children being burned by the heated bottles.

Scientists at the Boyce Thompson Institute have constructed a comprehensive “super-pangenome” for watermelon and its wild relatives, uncovering beneficial genes lost during domestication that could improve disease resistance and fruit quality of this vital fruit crop.

“We aimed to delve deeper into the genetic variations that make watermelons so diverse and unique,” stated Professor Zhangjun Fei, the study’s lead author. “Our findings not only provide insights into the evolutionary journey of watermelons but also present significant implications for breeding and disease resistance.”

The watermelon super-pangenome was built using reference genome sequences and genome resequencing data from 547 watermelon accessions spanning four species — cultivated watermelon (Citrullus lanatus) and its wild relatives C. mucosospermus, C. amarus, and C. colocynthis.

Analyses of the super-pangenome revealed that many disease-resistance genes present in wild species were lost during domestication, as early farmers selected for fruit quality traits like sweetness, flesh color, and rind thickness. “These beneficial genes could be reintroduced into modern cultivars to breed more resilient watermelon varieties,” noted Fei.

A key discovery of the research, recently published in the Plant Biotechnology Journal, was the identification of a tandem duplication of the sugar transporter gene ClTST2 that enhances sugar accumulation and fruit sweetness in cultivated watermelon. This genetic variant was rare in wild watermelons but was selected during domestication.

“The super-pangenome provides a valuable genetic toolkit for breeders and researchers to improve cultivated watermelon,” said Fei. “By understanding the genetic makeup and evolutionary patterns of watermelons, we can develop varieties with enhanced yield, increased disease resistance, and improved adaptability.”

This research was supported by grants from the USDA National Institute of Food and Agriculture Specialty Crop Research Initiative (2015-51181-24285 and 2020-51181-32139) and the US National Science Foundation (IOS-1855585).

Using scaffolds made of folded DNA, MIT engineers have come up with a new way to precisely assemble arrays of quantum rods. By depositing quantum rods onto a DNA scaffold in a highly controlled way, the researchers can regulate their orientation, which is a key factor in determining the polarization of light emitted by the array. This makes it easier to add depth and dimensionality to a virtual scene.

“One of the challenges with quantum rods is: How do you align them all at the nanoscale so they’re all pointing in the same direction?” says Mark Bathe, an MIT professor of biological engineering and the senior author of the new study. “When they’re all pointing in the same direction on a 2D surface, then they all have the same properties of how they interact with light and control its polarization.”

MIT postdocs Chi Chen and Xin Luo are the lead authors of the paper, which appears today in Science Advances. Robert Macfarlane, an associate professor of materials science and engineering; Alexander Kaplan PhD ’23; and Moungi Bawendi, the Lester Wolfe Professor of Chemistry, are also authors of the study.

Nanoscale structures

Over the past 15 years, Bathe and others have led in the design and fabrication of nanoscale structures made of DNA, also known as DNA origami. DNA, a highly stable and programmable molecule, is an ideal building material for tiny structures that could be used for a variety of applications, including delivering drugs, acting as biosensors, or forming scaffolds for light-harvesting materials.

Bathe’s lab has developed computational methods that allow researchers to simply enter a target nanoscale shape they want to create, and the program will calculate the sequences of DNA that will self-assemble into the right shape. They also developed scalable fabrication methods that incorporate quantum dots into these DNA-based materials.

In a 2022 paper, Bathe and Chen showed that they could use DNA to scaffold quantum dots in precise positions using scalable biological fabrication. Building on that work, they teamed up with Macfarlane’s lab to tackle the challenge of arranging quantum rods into 2D arrays, which is more difficult because the rods need to be aligned in the same direction.

Existing approaches that create aligned arrays of quantum rods using mechanical rubbing with a fabric or an electric field to sweep the rods into one direction have had only limited success. This is because high-efficiency light-emission requires the rods to be kept at least 10 nanometers from each other, so that they won’t “quench,” or suppress, their neighbors’ light-emitting activity.

To achieve that, the researchers devised a way to attach quantum rods to diamond-shaped DNA origami structures, which can be built at the right size to maintain that distance. These DNA structures are then attached to a surface, where they fit together like puzzle pieces.

“The quantum rods sit on the origami in the same direction, so now you have patterned all these quantum rods through self-assembly on 2D surfaces, and you can do that over the micron scale needed for different applications like microLEDs,” Bathe says. “You can orient them in specific directions that are controllable and keep them well-separated because the origamis are packed and naturally fit together, as puzzle pieces would.”

Assembling the puzzle

As the first step in getting this approach to work, the researchers had to come up with a way to attach DNA strands to the quantum rods. To do that, Chen developed a process that involves emulsifying DNA into a mixture with the quantum rods, then rapidly dehydrating the mixture, which allows the DNA molecules to form a dense layer on the surface of the rods.

This process takes only a few minutes, much faster than any existing method for attaching DNA to nanoscale particles, which may be key to enabling commercial applications.

“The unique aspect of this method lies in its near-universal applicability to any water-loving ligand with affinity to the nanoparticle surface, allowing them to be instantly pushed onto the surface of the nanoscale particles. By harnessing this method, we achieved a significant reduction in manufacturing time from several days to just a few minutes,” Chen says.

These DNA strands then act like Velcro, helping the quantum rods stick to a DNA origami template, which forms a thin film that coats a silicate surface. This thin film of DNA is first formed via self-assembly by joining neighboring DNA templates together via overhanging strands of DNA along their edges.

The researchers now hope to create wafer-scale surfaces with etched patterns, which could allow them to scale their design to device-scale arrangements of quantum rods for numerous applications, beyond only microLEDs or augmented reality/virtual reality.

“The method that we describe in this paper is great because it provides good spatial and orientational control of how the quantum rods are positioned. The next steps are going to be making arrays that are more hierarchical, with programmed structure at many different length scales. The ability to control the sizes, shapes, and placement of these quantum rod arrays is a gateway to all sorts of different electronics applications,” Macfarlane says.

“DNA is particularly attractive as a manufacturing material because it can be biologically produced, which is both scalable and sustainable, in line with the emerging U.S. bioeconomy. Translating this work towards commercial devices by solving several remaining bottlenecks, including switching to environmentally safe quantum rods, is what we’re focused on next,” Bathe adds.

The research was funded by the Office of Naval Research, the National Science Foundation, the Army Research Office, the Department of Energy, and the National Institute of Environmental Health Sciences.