Using CRISPR/Cas9 to edit the genome of Euglena gracilis, Dr. Masami Nakazawa and her team at the Graduate School of Agriculture’s Department of Applied Biochemistry produced stable mutants that created wax esters two carbons shorter than the wild-type species.

This improvement in the cold flow of the wax esters makes them more applicable as feedstock for biofuels. Among the factors favorable to using Euglena gracilis as a biofuel source are its ability to grow easily through photosynthesis and anaerobic production of wax esters.

“This achievement is expected to serve as a fundamental technology for replacing some petroleum-based production of wax esters with biological sources,” Dr. Nakazawa affirmed.

The interface between different quantum field theories is an important concept that arises in a variety of problems in particle physics and condensed matter physics. However, it has been difficult to calculate the transmission rates of energy and information across interfaces.

Hirosi Ooguri, Professor at the Kavli Institute for the Physics and Mathematics of the Universe (Kavli IPMU, WPI) at the University of Tokyo and Fred Kavli Professor at the California Institute of Technology, together with his collaborators, Associate Professor Yuya Kusuki at Kyushu University, and Professor Andreas Karch and graduate students Hao-Yu Sun and Mianqi Wang at the University of Texas, Austin, showed that for theories in two dimensions with scale invariance there are simple and universal inequalities between three quantities: Energy transfer rate, Information transfer rate, and the size of Hilbert space (measured by the rate of increase of the number of states at high energy). Namely,

[ energy transmittance ] ≤ [ information transmittance] ≤ [ size of the Hilbert space ].

These inequalities imply that, in order to transmit energy, information must also be transmitted, and both require a sufficient number of states. They also showed that no stronger inequality is possible.

Both energy and information transmissions are important quantities, but they are difficult to calculate, and no relationship between them was known. By showing the inequality between these quantities, this paper sheds new light on this important but difficult problem.

The research is published in ACS Nano, a peer-reviewed scientific journal and is featured on the cover of the journal.

Advances in computing technology continue to increase the demand for efficient data storage solutions. Spintronic magnetic tunnel junctions (MTJs) — nanostructured devices that use the spin of the electrons to improve hard drives, sensors, and other microelectronics systems, including Magnetic Random Access Memory (MRAM) — create promising alternatives for the next generation of memory devices.

MTJs have been the building blocks for the non-volatile memory in products like smart watches and in-memory computing with a promise for applications to improve energy efficiency in AI.

Using a sophisticated electron microscope, researchers looked at the nanopillars within these systems, which are extremely small, transparent layers within the device. The researchers ran a current through the device to see how it operates. As they increased the current, they were able to observe how the device degrades and eventually dies in real time.

“Real-time transmission electron microscopy (TEM) experiments can be challenging, even for experienced researchers,” said Dr. Hwanhui Yun, first author on the paper and postdoctoral research associate in the University of Minnesota’s Department of Chemical Engineering and Material Sciences. “But after dozens of failures and optimizations, working samples were consistently produced.”

By doing this, they discovered that over time with a continuous current, the layers of the device get pinched and cause the device to malfunction. Previous research theorized this, but this is the first time researchers have been able to observe this phenomenon. Once the device forms a “pinhole” (the pinch), it is in the early stages of degradation. As the researchers continued to add more and more current to the device, it melts down and completely burns out.

“What was unusual with this discovery is that we observed this burn out at a much lower temperature than what previous research thought was possible,” said Andre Mkhoyan, a senior author on the paper and professor and Ray D. and Mary T. Johnson Chair in the University of Minnesota Department of Chemical Engineering and Material Sciences. “The temperature was almost half of the temperature that had been expected before.”

Looking more closely at the device at the atomic scale, researchers realized materials that small have very different properties, including melting temperature. This means that the device will completely fail at a very different time frame than anyone has known before.

“There has been a high demand to understand the interfaces between layers in real time under real working conditions, such as applying current and voltage, but no one has achieved this level of understanding before,” said Jian-Ping Wang, a senior author on the paper and a Distinguished McKnight Professor and Robert F. Hartmann Chair in the Department of Electrical and Computer Engineering at the University of Minnesota.

“We are very happy to say that the team has discovered something that will be directly impacting the next generation microelectronic devices for our semiconductor industry,” Wang added.

The researchers hope this knowledge can be used in the future to improve design of computer memory units to increase longevity and efficiency.

In addition to Yun, Mkhoyan, and Wang, the team included University of Minnesota Department of Electrical and Computer Engineering postdoctoral researcher Deyuan Lyu, research associate Yang Lv, former postdoctoral researcher Brandon Zink, and researchers from the University of Arizona Department of Physics.

This work was funded by SMART, one of seven centers of nCORE, a Semiconductor Research Corp. program sponsored by the National Institute of Standards and Technology (NIST); University of Minnesota Grant-in-Aid funding; National Science Foundation (NSF); and Defense Advanced Research Projects Agency (DARPA). The work was completed in collaboration with the University of Minnesota Characterization Facility and the Minnesota Nano Center.

In a new study, researchers have determined through both statistical analysis and in experiments that soil pH is a driver of microbial community composition — but that the need to address toxicity released during nitrogen cycling ultimately shapes the final microbial community.

“The physical environment is affecting the nature of microbial interactions, and that affects the assembly of the community,” said co-lead author Karna Gowda, assistant professor of microbiology at The Ohio State University. “People in the field understood these two things must be important at some level, but there wasn’t a lot of evidence for it. We’re adding some specificity and mechanisms to this idea.”

The work helps clarify the microbial underpinnings of global nitrogen cycling and may provide a new way to think about emissions of nitrous oxide, a potent greenhouse gas, Gowda said.

The research was published recently in Nature Microbiology.

Microbes keep soil healthy and productive by recycling nutrients, and are particularly important for converting nitrogen into forms that plants can use. Underground organisms living in the same environment are also highly interconnected, preying on each other, participating in chemical exchanges and providing community benefits.

For this work, Gowda and colleagues used a dataset from a worldwide collection of topsoil samples, sequencing the genomes of microbes present in the samples and analyzing important characteristics of the soil — such as nitrogen and carbon content and pH, a measure of soil’s acidity.

“We wanted to look at trends that were widespread and that would manifest around the planet across very different environments,” Gowda said.

With billions of bacteria present in a sample of soil, the researchers relied on the genetic makeup of microbial communities to determine their functional roles.

The team zeroed in on genes that identified which bacteria were involved in denitrification — converting nitrogen compounds from bioavailable forms into nitrous oxide and dinitrogen gas that’s released in the atmosphere. A bioinformatics analysis showed that soil pH was the most important environmental factor associated with the abundance of these organisms.

To test the statistical finding, the researchers conducted lab enrichment experiments, running a natural microbial community through different conditions of growth.

During denitrification, specific enzymes have roles in the conversion of nitrate into various nitrogen-containing compounds. One of these forms, nitrite, is more toxic in acidic soil (low pH) than it is under neutral conditions with higher pH.

The experiments showed that strains with enzymes called Nar, linked to creating toxic nitrite, and strains with enzymes called Nap, linked to consuming nitrite, fluctuated based on the acidity of the soil.

“We found more of Nar at low pH and less of Nap, and vice versa as the soil pH moved toward neutral,” Gowda said. “So we see two different types of organisms prevalent at acidic versus neutral pH, but we also find that that’s actually not explaining what’s going on. It’s not just the environment that’s determining who’s there — it’s actually the environment plus interactions between more organisms in the community.

“This means that pH is affecting the interaction between organisms in the community in a more or less consistent way — it’s always about the toxicity of nitrite. And this highlights how different bacteria work together to thrive in varying soil pH levels.”

That finding was novel and important, Gowda said. Bacteria and other microorganisms are known to be driven by a will to survive, but they also rely on each other to stay safe — and that cooperation has implications for environmental health, the research suggests.

“While individual fitness effects clearly play a role in defining patterns in many contexts, interactions are likely essential to explaining patterns in a variety of other contexts,” the authors wrote.

Understanding how interactions and the environment affect nitrous oxide emissions could provide new insights into reducing this potent greenhouse gas, Gowda said: Denitrifying bacteria are key sources and sinks of nitrous oxide in agricultural soils. While past studies have focused on the behavior of these nitrous oxide-emitting organisms in different pH conditions, considering their ecological interactions may offer new strategies to lower emissions.

This work was supported by the National Science Foundation, the University of Chicago, the National Institute of General Medical Sciences, a James S. McDonnell Foundation Postdoctoral Fellowship Award, and a Fannie and John Hertz Fellowship Award.

Co-authors include Seppe Kuehn, Kyle Crocker, Kiseok Keith Lee, Milena Chakraverti-Wuerthwein and Zeqian Li of the University of Chicago; Mikhail Tikhonov of Washington University in St. Louis; and Madhav Mani of Northwestern University.

The study, published in the European Physical Journal B, dives into the mathematical complexities of this common task, offering new insights into why scheduling often feels so impossible.

“If you like to think the worst about people, then this study might be for you,” quipped researcher Harsh Mathur, professor of physics at the College of Arts and Sciences at CWRU. “But this is about more than Doodle polls. We started off by wanting to answer this question about polls, but it turns out there is more to the story.”

Researchers used mathematical modeling to calculate the likelihood of successfully scheduling a meeting based on several factors: the number of participants (m), the number of possible meeting times (τ) and the number of times each participant is unavailable (r).

What they found: As the number of participants grows, the probability of scheduling a successful meeting decreases sharply.

Specifically, the probability drops significantly when more than five people are involved — especially if participant availability remains consistent.

“We wanted to know the odds,” Mathur said. “The science of probability actually started with people studying gambling, but it applies just as well to something like scheduling meetings. Our research shows that as the number of participants grows, the number of potential meeting times that need to be polled increases exponentially.

“The project had started half in jest but this exponential behavior got our attention. It showed that scheduling meetings is a difficult problem, on par with some of the great problems in computer science.”

‘More to the story’

Interestingly, researchers found a parallel between scheduling difficulties and physical phenomena. They observed that as the probability of a participant rejecting a proposed meeting time increases, there’s a critical point where the likelihood of successfully scheduling the meeting drops sharply. It’s a phenomenon similar to what is known as “phase transitions” in physics, Mathur said, such as ice melting into water.

“Understanding phase transitions mathematically is a triumph of physics,” he said. “It’s fascinating how something as mundane as scheduling can mirror the complexity of phase transitions.”

Mathur also noted the study’s broader implications, from casual scenarios like sharing appetizers at a restaurant to more complex settings like drafting climate policy reports, where agreement among many is needed.

“Consensus-building is hard,” Mathur said. “Like phase transitions, it’s complex. But that’s also where the beauty of mathematics lies — it gives us tools to understand and quantify these challenges.”

Mathur said the study contributes insights into the complexities of group coordination and decision-making, with potential applications across various fields.

Joining Mathur in the study were physicists Katherine Brown, of Hamilton College, and Onuttom Narayan, of the University of California, Santa Cruz.

Lead investigator David C. Whiteman, MBBS, PhD, Cancer Control Group, QIMR Berghofer Medical Research Institute, and Faculty of Medicine, The University of Queensland, Brisbane, Australia, explains, “There has been a general observation in numerous populations that melanomas appear to arise at different rates in men and women. We decided to investigate this observation rigorously and assess whether these differences have been constant through time or across generations by using large-scale data from population registries to investigate long-term melanoma trends in men and women.

The research team analyzed more than 40 years of melanoma data from Queensland, Australia, the USA, and Scotland. These three populations were chosen because historically they have had high (Queensland), moderate (USA), and low (Scotland) rates of melanoma. Over time, the rates of melanoma increased in all three populations, especially among women. In women in all populations, melanomas arise most commonly on the limbs, whereas in men, melanomas arise most commonly on the trunk and head and neck. In both sexes, there has been a steady increase in melanomas on the head and neck with increasing age.

Researchers found that in virtually all investigated populations, women experience higher rates of melanoma than men in early life (up to age ~45 years), but men develop melanomas at higher rates than women later in life (from ages ≥65 years). Furthermore, these sex-specific trends reflect complex patterns of incidence across body sites that vary consistently with age. Thus, in early life, women experience higher rates of lower limb melanomas than men, which persists into older ages. Also, on the upper limbs, women experience substantially higher rates than men from young ages until middle age (45-64 years), after which men experience higher rates. In contrast, on the head and neck and the trunk, melanomas occur at higher incidence in men than in women early in life. On all body sites, the rate at which melanoma incidence rises with age is much more rapid for men than for women.

The study confirms that men and women experience melanoma in different ways. While this is most likely driven by different patterns of sun exposure between men and women, there appear to be inherent differences in the ways in which melanomas develop at different body sites in women compared with men. Understanding the underlying biological differences could provide important clues about the etiology of this enigmatic cancer.

Dr. Whiteman concludes, “Invasive melanomas are potentially lethal cancers that are increasing rapidly in incidence. We need to understand how these cancers arise, and what drives their development, if we are to find better ways to prevent them. Studies like this one suggest that we may need to target our prevention efforts differently for men and women if we are to be effective in our attempts to control this cancer.”