These nano-sized motors are highly programmable and can be designed for use in molecular computation, diagnostics, and transport. Despite their genius, DNA-nanoparticle motors don’t have the speed of their biological counterparts, the motor protein, which is where the issue lies. This is where researchers come in to analyze, optimize, and rebuild a faster artificial motor using single-particle tracking experiment and geometry-based kinetic simulation.

“Natural motor proteins play essential roles in biological processes, with a speed of 10-1000 nm/s. Until now, artificial molecular motors have struggled to approach these speeds, with most conventional designs achieving less than 1 nm/s,” said Takanori Harashima, researcher and first author of the study.

Researchers published their work in Nature Communications on January 16th, 2025, featuring a proposed solution to the most pressing issue of speed: switching the bottleneck.

The experiment and simulation revealed that binding of RNase H is the bottleneck in which the entire process is slowed. RNase H is an enzyme involved in genome maintenance, and breaks down RNA in RNA/DNA hybrids in the motor. The slower RNase H binding occurs, the longer the pauses in motion, which is what leads to a slower overall processing time. By increasing the concentration of RNase H, the speed was markedly improved, showing a decrease in pause lengths from 70 seconds to around 0.2 seconds.

However, increasing motor speed came at the cost of processivity (the number of steps before detachment) and run-length (the distance the motor travels before detachment). Researchers found that this trade-off between speed and processivity/run-length could be improved by a larger DNA/RNA hybridization rate, bringing the simulated performance closer to that of a motor protein.

The engineered motor, with redesigned DNA/RNA sequences and a 3.8-fold increase in hybridization rate, achieved a speed of 30 nm/s, 200 processivity, and a 3 μm run-length. These results demonstrate that the DNA-nanoparticle motor is now comparable to a motor protein in performance.

“Ultimately, we aim to develop artificial molecular motors that surpass natural motor proteins in performance,” said Harashima. These artificial motors can be very useful in molecular computations based on the motion of the motor, not to mention their merit in the diagnosis of infections or disease-related molecules with a high sensitivity.

The experiment and simulation done in this study provide an encouraging outlook for the future of DNA-nanoparticle and related artificial motors and their ability to measure up to motor proteins as well as their applications in nanotechnology.

Takanori Harashima, Akihiro Otomo, and Ryota Iino of the Institute for Molecular Science at National Institutes of Natural Sciences and the Graduate Institute for Advanced Studies at SOKENDAI contributed to this research.

This work was supported by JSPS KAKENHI, Grants-in-Aid for Transformative Research Areas (A) (Publicly Offered Research) “Materials Science of Meso-Hierarchy” (24H01732) and “Molecular Cybernetics” (23H04434), Grant-in-Aid for Scientific Research on Innovative Areas “Molecular Engine” (18H05424), Grant-in-Aid for Early-Career Scientists (23K13645), JST ACT-X “Life and Information” (MJAX24LE), and Tsugawa foundation Research Grant for FY2023.

Scientists have discovered that juvenile bottlenose dolphins have specialized receptors for detecting the fatty acids in their mother’s milk. These findings, published in the journal Marine Mammal Science, offer important insights into how these marine mammals grow, feed, and communicate.

The new findings challenge previous assumptions about cetacean sensory systems. Unlike land mammals, dolphins and other marine mammals have limited olfactory capabilities – their sense of smell is largely nonfunctional in aquatic environments. Researchers have therefore speculated that dolphins had other ways of sensing their surroundings and detecting food.

Fat plays an essential role in providing energy and supporting brain development in dolphin calves, which are entirely dependent on their mother’s milk during their early stages of life.

“We looked at the tongue of a young Indo-Pacific bottlenose dolphin and confirmed special structures that may help it detect fat,” says the study’s first author Hinako Katsushima of the Graduate School of Environmental Science at Japan’s Hokkaido University. “At the back of the tongue, there’s a V-shaped row of taste receptors that are specifically tuned to pick up fatty acids. These receptors also have enzymes that help break down the fat, making it easier for the dolphin to sense and process it.”

In a second experiment, the team gave young dolphins a choice between two liquids: one containing milk and the other a cloudy solution. The dolphin showed an unexpected preference for the cloudy solution. This reinforces the finding that dolphins can distinguish between the two liquids, but the researchers are unsure why they avoided the milk. One possibility is that they found the milk unfamiliar – it was a mixture of milk from two females – and so avoided it from a fear of new foods, a habit called neophobia.

“Our findings suggest that the ability to detect fatty acids in their mother’s milk is part of a specialized ‘fat taste’ system that could help dolphins assess the nutritional value of their food,” says Assistant Professor Takashi Hayakawa from the Faculty of Environmental Earth Science at Hokkaido University, who led the study. “In the wild, where fat-rich diets are critical for survival, this capability may provide dolphins with an evolutionary advantage, allowing them to select high-quality milk from their mothers and later evaluate the nutritional content of their prey.”

The new study opens new avenues for understanding how marine mammals perceive and interact with their environment, as well as how they communicate and forage in the wild. Further research will be necessary to explore the full scope of this “fat taste” system and how it functions in other marine species.

Researchers have identified a key pathway that links how neurons send signals to each other, or synaptic activity, to the expression of genes necessary for long-term changes in the brain, providing crucial insights into the molecular processes underlying memory formation.

“These findings illuminate a critical mechanism that connects local synaptic activity to the broader gene expression changes necessary for learning and memory,” said Mark Dell’Acqua, professor of pharmacology at the University of Colorado Anschutz Medical Campus and senior author of the study. “This paper is mainly a basic science finding of a fundamental process of what nerve cells do. Understanding this relay system not only enhances our knowledge of brain function but could also better inform therapeutic treatments for cognitive disorders.”

The nucleus where the genes that modify neuron function are controlled is a long distance away from where neurons receive input from their synapses, which are located in distant dendrites that extend like branches from the trunk of a tree. This research focuses on the cAMP-response element binding protein (CREB), a transcription factor known to regulate genes vital for dynamic changes at synapses which is essential for neuronal communication. Despite CREB’s well-documented role in supporting learning and memory, the exact mechanisms leading to CREB activation during neuronal activity remain unclear.

Using advanced microscopy techniques, graduate student Katlin Zent in Dr. Dell’Acqua’s research group revealed a crucial relay mechanism involving the activation of receptors and ion channels generating calcium signals that rapidly communicates from synapses in remote dendrite branches to the nucleus in the neuron cell body.

“Going forward, this research will enable us to better examine the way these pathways are utilized in different disease states,” said Dell’Acqua. “We could see exactly what parts of this new mechanism are interfered with and where, giving us a better idea of how this pathway affecting learning and memory is impacted. This research highlights potential targets for interventions aimed at conditions like Alzheimer’s disease and other memory-related disorders.”

“Although past evidence showing causal links between modelling and getting rewarded for violence had an immediate impact on aggressive behavior in 4-year-old children, few studies have investigated long-term risks with antisocial behavior. We studied such risks in mid-adolescence, explained Pagani, who is also a researcher at the Centre de recherche Azrieli du CHU Sainte-Justine. It was ideal to study this question with typically developing middle-class children because, as a population, they have the lowest chances of engaging in aggression and behavior harmful to others.”

Close to 2,000 children

In all, Pagani and her team looked at 963 girls and 982 boys born between the springs of 1997 and 1998 who were enrolled in the Quebec Longitudinal Study of Child Development. Parents reported the frequency of their child’s exposure to violent television content at ages 3.5 and 4.5 years old. Boys and girls then self-reported on several aspects of antisocial behavior at age 15.

The study defines screen violence as anything “characterized by physical aggression, verbal aggression, and relational aggression […] depicting situations that intentionally attempt or cause harm to others.” Children, the study says “are attracted to fast-paced, stimulating violent content, which often features appealing characters like superheroes who commit and are rewarded for aggressive acts, thus increasing the likelihood of exposure.”

The researchers then conducted analyses to examine whether exposure to violent television content at ages 3.5 and 4.5 years predicted later antisocial behavior eleven years later.

The researcher added, “We statistically took into account alternative child and family factors that could have explained our results, to be as close as possible to the truth in the relationships we were looking at.”

Boys stand out

At age 15, for boys only, preschool violent televiewing predicted increases in antisocial behavior. Being exposed to violent content in early childhood predicted later aggressive behaviors such as hitting or beating another person, with the intention of obtaining something, stealing, with or without any apparent reason.

Risks also included threats, insults, and gang fight involvement. The use of weapons is also among the behavioral outcomes predicted by exposure to childhood television violence in this study. No effects were found for girls, which was not surprising given that boys are generally more exposed to such content.

Pagani concluded, “Our study provides compelling evidence that early childhood exposure to media violence can have serious, long-lasting consequences, particularly for boys. This underscore the urgent need for public health initiatives that targets campaigns to inform parents and communities about the long-term risks and empower them to make informed choices about young children’s screen content exposure.”

The entire team of students from Université de Montréal and researchers from the United States and Italy established that, “Parents and communities can play a crucial role in limiting future problems by carefully avoiding young children’s exposure to violent media content.”

Psoriasis is a hereditary, chronic skin condition that can also result in inflammation of the joints. In Sweden, almost 300,000 people live with some form of the condition. Chronic inflammatory bowel diseases (IBD), especially Crohn’s disease, are more common in patients with psoriasis than in the rest of the population.

“Previous research has also shown that people with psoriasis have more gastrointestinal problems than the general population. However we didn’t know much about why this is the case. With our study, we can now show that people with psoriasis often have invisible inflammation in their small intestines, with an increased risk of what’s called leaky gut,” says Maria Lampinen, researcher at Uppsala University.

Pro-inflammatory activity in the gut

The study involved 18 patients with psoriasis and 15 healthy controls as subjects. None of the participants had been diagnosed with gastrointestinal diseases. Samples were taken from both their small and large bowel. The researchers then studied different types of immune cells in the mucous membrane.

“It turned out that psoriasis sufferers had higher numbers of certain types of immune cells in their small intestine, and the cells showed signs of pro-inflammatory activity. Interestingly, we found the same type of immune cells in skin flare-ups from psoriasis patients, suggesting that the inflammation of the skin may have an impact on the gut, or vice versa.

Increased propensity for leaky gut

Normally, the intestinal mucosa act as a protective barrier that also allows nutrients and water to pass through it. In some autoimmune diseases, the intestinal barrier may function poorly. This is called having a leaky gut, and leads to bacteria and harmful substances leaking through the intestinal barrier and causing inflammation. This can also cause more widespread inflammation when these substances are spread via the bloodstream.

Half of the psoriasis patients in the study had increased intestinal barrier permeability or leaky gut. These same patients also reported more gastrointestinal symptoms such as abdominal pain and bloating than patients with a normal intestinal barrier. They also had elevated levels of inflammatory substances in their intestines.

“Given that the psoriasis patients in our study had relatively mild skin disease and showed no visible intestinal inflammation in a gastroscopy, they had surprisingly clear changes in their small intestine compared to healthy controls. These changes could explain why psoriasis sufferers often have gastrointestinal problems, and an increased risk of developing Crohn’s disease.

Important research for these patients

The Psoriasisförbundet (the Swedish Psoriasis Association) member magazine published an article about this study. Following its publication, Maria Lampinen received many e-mails from people who recognised this phenomenon.

“They wanted to know more about the link between the gut and the skin because they recognised that symptoms from their gut and skin were often linked. So it feels like this research is needed and is important for the patients themselves. A greater understanding of gastrointestinal problems in psoriasis patients can help the healthcare system to pay more attention to the link between the gut and the skin in patients with psoriasis, and in the long term it could also lead to better treatment of these problems.

The study was funded by the Psoriasis Association’s managed funds and Hudfonden (the Skin Foundation), among others.

Trust in scientists is at a moderately high level worldwide, according to a new study. This is the conclusion of an international team of 241 researchers led by Viktoria Cologna of ETH Zurich and Niels G. Mede of the University of Zurich (UZH). “Our results show that most people in most countries have a relatively high level of trust in scientists,” says principal investigator Viktoria Cologna, “and want them to play an active role in society and politics.” The study found no evidence for the oft-repeated claim of a crisis of trust in science.

The study is the result of the TISP Many Labs study, a collaborative effort that allowed the authors to survey 71,922 people in 68 countries, including many under-researched countries in the Global South. For the first time since the coronavirus pandemic, the study provides global, representative survey data on the populations and regions of the world in which researchers are perceived to be most trustworthy, the extent to which they should engage with the public, and whether science is prioritizing important research issues.

No crisis of trust in science

Across 68 countries, the study finds that the majority of the public has a relatively high level of trust in scientists (mean trust level = 3.62, on a scale of 1 = very low trust to 5 = very high trust). The majority of respondents also perceive scientists as qualified (78%), honest (57%) and concerned about people’s well-being (56%).

However, the results also reveal some areas of concern. Globally, less than half of respondents (42%) believe that scientists pay attention to the views of others. “Our results also show that many people in many countries feel that the priorities of science are not always well aligned with their own priorities,” says co-author Niels G. Mede. “We recommend that scientists take these results seriously and find ways to be more receptive to feedback and open to dialogue with the public.”

Polarization of population groups and differences between countries

The findings confirm the results of previous studies that show significant differences between countries and population groups. In particular, people with right-wing political views in Western countries tend to have less trust in scientists than those with left-wing views. This suggests that attitudes toward science tend to polarize along political lines. In most countries, however, political orientation and trust in scientists were not related.

Call for active engagement of scientists

A majority of respondents want science to play an active role in society and policy-making. Globally, 83% of respondents believe that scientists should communicate with the public about science, providing an impetus for increased science communication efforts. Only a minority (23%) believe that scientists should not actively advocate for specific policies. 52% believe that scientists should be more involved in the policy-making process.

Participants gave high priority to research to improve public health, solve energy problems, and reduce poverty. On the other hand, research to develop defense and military technology was given a lower priority. In fact, participants explicitly believe that science is prioritizing the development of defense and military technology more than they would like, highlighting a potential misalignment between public and scientific priorities.