Zebrafish are smarter than we thought

A new study from MIT and Harvard University suggests that the brains of the seemingly simple zebrafish are more sophisticated than previously thought. The researchers found that larval zebrafish can use visual information to create three-dimensional maps of their physical surroundings.
Photo Credit: Petr Kuznetsov

A new study from MIT and Harvard University suggests that the brains of the seemingly simple zebrafish are more sophisticated than previously thought. The researchers found that larval zebrafish can use visual information to create three-dimensional maps of their physical surroundings — a feat that scientists didn’t think was possible.

In the new study, the researchers discovered that zebrafish can move around environmental barriers while escaping predators. The findings suggest that zebrafish are “much smarter than we thought,” and could be used as a model to explore many aspects of human visual perception, the researchers say.

“These results show you can study one of the most fundamental computational problems faced by animals, which is perceiving a 3D model of the environment, in larval zebrafish,” says Vikash Mansinghka, a principal research scientist in MIT’s Department of Brain and Cognitive Sciences and an author of the new study.

Andrew Bolton, an MIT research scientist and a research associate at Harvard University, is the senior author of the new study, which appears in the journal Current Biology. Hanna Zwaka, a Harvard postdoc, and Olivia McGinnis, a recent Harvard graduate who is now a graduate student at the Oxford University, are the paper’s lead authors.

Amphibian Population Decreased Rapidly in the Last Three Years

Lake frogs are among the largest modern amphibians.
Photo Credit: Ilya Safarov

Biologists have recorded severe simultaneous drops in the numbers of three different species of frogs and newts - rare and widespread. The largest population declines occurred among juveniles, but the scientists noted that adults and egg clutches were also affected. The description and results of the study are published in the journal Conservation Science and Practice.

"We believe that a wide range of anthropogenic adverse factors combined with natural fluctuations are responsible for the population decline. Among the causes are global warming, pathogenic infections, habitat loss and exposure to agro-industrial chemicals. But the main reason is drought: reduced precipitation led to a shortage of water in reservoirs and increased water temperature, which ultimately affected the amphibian population," explains Vladimir Vershinin, co-author of the work, Head of the Department of Biodiversity and Bioecology of Ural Federal University, Head of the Laboratory of Functional Ecology of Terrestrial Animals of the Institute of Plant and Animal Ecology of Ural Branch of Russian Academy of Science.

How the body's own cannabinoids far-range the bronchi

The research team led by Prof. Dr. Daniela Wenzel, Dr. Michaela Matthey, Alexander Seidinger and Annika Simon (from left) want to know how the bronchi can be set far.
Photo Credit: RUB, Marquard

Narrowing the bronchi makes many lung diseases like asthma so dangerous. Researchers have discovered a new signaling pathway that leads to the expansion of the respiratory tract.

Inhalation drugs against asthma and other obstructive pulmonary diseases often decrease in their effects after prolonged use. A research team led by Prof. Dr. Daniela Wenzel from the Department of Systems Physiology at the Ruhr University Bochum was now able to show an alternative signal path through which the body's own cannabinoids lead to the bronchi being expanded. This raises hopes for alternative treatment options. Asthma also appears to be associated with a lack of these cannabinoids in the bronchi, which could be one of the causes of the disease. The research team reports in the journal Nature Communications.

The bronchi are far from the body's own cannabinoids

Obstructive lung diseases are the third leading cause of death worldwide. These include, for example, the chronic obstructive pulmonary disease COPD, from which many smokers suffer, but also bronchial asthma. In an asthma attack, the bronchi contracts so strongly that exhalation is no longer possible - this can be life-threatening. "Asthma is an inflammatory process, but the narrowing of the bronchi is fatal," explains Annika Simon, first author of the study. “That is why we are particularly interested in regulating this narrowing."

What Darwin would discover today

Filmmaker Victor Rault set sail from Plymouth on the Captain Darwin in 2021, following in the footsteps of Darwin's HMS Beagle. He wants to explore how the ecosystem has changed since Darwin's voyage in 1832.
Photo Credit: Victor Rault / Captain Darwin 

"If Charles Darwin had had the opportunity to dive off the Cape Verde Islands, he would have been completely thrilled", Eduardo Sampaio is convinced, because Darwin would have seen a fascinating, species-rich landscape. But he lacked diving equipment. Thus, in his notes The Voyage of the Beagle, Darwin described Cape Verde as a barren landscape.

Eduardo Sampaio, affiliate member of the Cluster of Excellence "Centre for the Advanced Study of Collective Behavior" (CASCB) at the University of Konstanz, had quite the opposite experience. He was invited on board the ship Captain Darwin by filmmaker Victor Rault to continue his octopus research.

Victor Rault, 30, set sail from Plymouth on the Captain Darwin in 2021, following in the footsteps of Darwin's HMS Beagle. He wants to explore how the ecosystem has changed since Darwin's voyage on the HMS Beagle in 1832. Researchers and citizens have been invited to travel along and conduct experiments in the spirit of Darwin. "When Victor told me about his project, I was baffled", recalls biologist Eduardo Sampaio from Portugal. He says: "It was immediately clear to me that it's an excellent idea to retrace the path of Charles Darwin. I was more than keen to jump on board!"

Newly Developed Gene Classifier Identifies Risk of Breast Pre-Cancer Progression

Photo Credit: Angiola Harry

A team of researchers mapping a molecular atlas for ductal carcinoma in situ (DCIS) has made a major advance toward distinguishing whether the early pre-cancers in the breast will develop into invasive cancers or remain stable.

Analyzing samples from patients who had undergone surgery to remove areas of DCIS, the team identified 812 genes associated with cancer progression. Using this gene classifier, they were then able to predict the risk of cancer cells recurring or progressing.

The study, which was published this week in the journal Cancer Cell, was led by E. Shelley Hwang, M.D., of the Duke Cancer Institute, and Rob West, M.D., Ph.D., of the Stanford University Medical Center. Their work is part of the Human Tumor Atlas Network under the Moonshot Initiative funded by the National Cancer Institute.

“There has been a long-standing debate over whether DCIS is cancer or a high-risk condition,” Hwang said. “In the absence of a way to make that determination, we currently treat everyone with surgery, radiation, or both.

“DCIS is diagnosed in more than 50,000 women a year, and about a third of those women have a mastectomy, so we are increasingly concerned that we might be overtreating many women,” Hwang said. “We need to understand the biology of DCIS better, and that’s what our research has been designed to do.”

Fruit flies use corrective movements to maintain stability after injury

Collaborators at the University of Colorado Boulder created a robotic wing made of plastic and cardboard laminate to study the mechanism by which fruit flies compensate for wing damage in flight. Photo Credit: Kaushik Jayaram

Fruit flies can quickly compensate for catastrophic wing injuries, researchers found, maintaining the same stability after losing up to 40% of a wing. This finding could inform the design of versatile robots, which face the similar challenge of having to quickly adapt to mishaps in the field.

The Penn State-led team published their results in Science Advances.

To run the experiment, researchers altered the wing length of anesthetized fruit flies, imitating an injury flying insects can sustain. They then suspended the flies in a virtual reality ring. Mimicking what flies would see when in flight, researchers played virtual imagery on tiny screens in the ring, causing the flies to move as if flying.

“We found flies compensate for their injuries by flapping the damaged wing harder and reducing the speed of the healthy one,” said corresponding author Jean-Michel Mongeau, Penn State assistant professor of mechanical engineering. “They accomplish this by modulating signals in their nervous system, allowing them to fine-tune their flight even after an injury.”

Looking at oxygen storage dynamics in three-way catalysts

Photo Credit: kalhh

In light of vehicular pollutants contributing to decreasing air quality, governments across the globe are posing stricter emission regulations for automobiles. This calls for the development of more efficient exhaust gas after-treatment systems (i.e., systems to “clean” exhaust gas before it is released into the atmosphere). The most common mode for treating exhaust emissions of gasoline-fueled internal combustion engines are three-way catalysts (TWCs) or catalytic converters. TWCs often comprise active metals such as platinum (Pt) and palladium (Pd) nanoparticles and oxygen storage materials with a high specific surface area, such as a solid solution of CeO2-ZrO2(CZ). These components can catalyze multiple oxidation and reduction reactions that can convert harmful exhaust from vehicular engines to harmless gases.

The durability, precision, and performance of a TWC is dependent on factors like the oxygen stored or removed from the bulk and surface of the oxygen storage materials. So, clearly understanding the oxygen transport and dynamics of the storage material is necessary to improve its efficiency. Unfortunately, there is a lack of techniques that can enable direct tracking of the oxygen storage process in TWCs.

‘Butterfly Bot’ is Fastest Swimming Soft Robot Yet

Inspired by the biomechanics of the manta ray, researchers at North Carolina State University have developed an energy-efficient soft robot that can swim more than four times faster than previous swimming soft robots. The robots are called “butterfly bots,” because their swimming motion resembles the way a person’s arms move when they are swimming the butterfly stroke.

“To date, swimming soft robots have not been able to swim faster than one body length per second, but marine animals – such as manta rays – are able to swim much faster, and much more efficiently,” says Jie Yin, corresponding author of a paper on the work and an associate professor of mechanical and aerospace engineering at NC State. “We wanted to draw on the biomechanics of these animals to see if we could develop faster, more energy-efficient soft robots. The prototypes we’ve developed work exceptionally well.”

The researchers developed two types of butterfly bots. One was built specifically for speed, and was able to reach average speeds of 3.74 body lengths per second. A second was designed to be highly maneuverable, capable of making sharp turns to the right or left. This maneuverable prototype was able to reach speeds of 1.7 body lengths per second.

Rapid fluctuations in oxygen levels coincided with Earth’s first mass extinction

Nevin Kozik during fieldwork to investigate how rapid changes in marine oxygen levels may have played a significant role in driving Earth’s first mass extinction.
Photo Credit: Courtesy of Nevin Kozik

Rapid changes in marine oxygen levels may have played a significant role in driving Earth’s first mass extinction, according to a new study led by Florida State University researchers.

About 443 million years ago, life on Earth was undergoing the Late Ordovician mass extinction, or LOME, which eliminated about 85% of marine species. Scientists have long studied this mass extinction and continue to investigate its possible causes, such as reduced habitat loss in a rapidly cooling world or persistent low-oxygen conditions in the oceans.

By measuring isotopes of the element thallium — which shows special sensitivity to changes in oxygen in the ancient marine environment — the research team found that previously documented patterns of this mass extinction coincided with an initial rapid decrease in marine oxygen levels followed by a rapid increase in oxygen. Their work is published online in the journal Science Advances.

“Paleontologists have noted that there were several groups of organisms, such as graptolites and brachiopods, that started to decline very early in this mass extinction interval, but we didn’t really have any good evidence of an environmental or climate signature to tie that early decline of these groups to a particular mechanism,” said co-author Seth Young, an associate professor in the Department of Earth, Ocean and Atmospheric Science. “This paper can directly link that early phase of extinction to changes in oxygen. We see a marked change in thallium isotopes at the same time these organisms start their steady decline into the main phase of the mass extinction event.”

Turning Wastewater into Fertilizer Is Feasible and Could Help to Make Agriculture More Sustainable

Photo Credit: Franck Barske

The wastewater draining from massive pools of sewage sludge has the potential to play a role in more sustainable agriculture, according to environmental engineering researchers at Drexel University. A new study, looking at a process of removing ammonia from wastewater and converting it into fertilizer, suggests that it’s not only technically viable, but also could help to reduce the environmental and energy footprint of fertilizer production — and might even provide a revenue stream for utilities and water treatment facilities.

A Sustainable Nitrogen Source

The production of nitrogen for fertilizer is an energy-intensive process and accounts for nearly 2% of global carbon dioxide emissions. In the last several years researchers have explored alternatives to the Haber-Bosch nitrogen production process, which has been the standard for more than a century. One promising possibility, recently raised by some water utility providers, is gleaning nitrogen from the waste ammonia pulled from water during treatment.

“Recovering nitrogen from wastewater would be a desirable alternative to the Haber-Bosch process because it creates a ‘circular nitrogen economy,’” said Patrick Gurian, PhD, a professor in Drexel's College of Engineering who helped lead the research, which was recently published in the journal Science of the Total Environment. “This means we are reusing existing nitrogen rather than expending energy and generating greenhouse gas to harvest nitrogen from the atmosphere, which is a more sustainable practice for agriculture and could become a source of revenue for utilities.”