The research vessel Norseman II carried scientists from the University of Alaska Fairbanks, the University of Maryland Center for Environmental Science and Clark University.

Maintaining the continuity of long-term observations is crucial as the region is affected by climate change. For example, the researchers collected sediments and small bottom-dwelling animals to help document harmful algal blooms that are becoming more common as Arctic waters warm. The blooms pose a threat to the humans and marine mammals that eat them.

Because of pandemic-related delays, the cruise began on Oct. 2 — a much later start than originally planned. Historically, the Bering and Chukchi sea ecosystem transitioned to lower-level activity as sea ice formed in October.

This year, unseasonably warm ocean temperatures delayed sea ice formation by several weeks. The lack of ice likely allowed the greater biological activity observed by the researchers.

“The recovered data are already showing the effects of oceanic heat that extends further into the fall and early winter,” said Seth Danielson of UAF’s College of Fisheries and Ocean Sciences.

The scientists collected data for several marine science programs monitoring the Pacific Arctic ecosystem.

The Distributed Biological Observatory, led by Jacqueline Grebmeier of UMCES, has been sampling productive hot spots since the late 1980s in U.S. Arctic waters.

The Arctic Marine Biodiversity Observing Network, led by Katrin Iken at UAF’s College of Fisheries and Ocean Sciences, is part of a national network studying how biodiversity and species distributions are changing as a result of climate change in the U.S. Arctic.

The researchers also visited the Chukchi Ecosystem Observatory, a set of highly instrumented oceanographic moorings that monitor the ecosystem year-round. “We only get one chance each year to deploy fresh sensors with new batteries, so this cruise was important to avoid interruptions to the observations,” said Danielson, who leads the project.

“This was a really worthwhile effort that paid off in making biological data available from a part of the year where there have been historically few observations,” said Grebmeier, the cruise’s chief scientist.

To protect communities in the Bering Strait from potential exposure to the COVID-19 virus, the team completed quarantines and multiple tests in Anchorage before the cruise. They traveled by chartered aircraft to Nome and were taken directly to the research vessel, bypassing the passenger terminal.

Everyone aboard also adhered to COVID-19 health and safety mandates from their institutions and followed an isolation and travel plan in accordance with the Port of Nome and the State of Alaska.

Funding for the cruise was provided by the National Oceanic and Atmospheric Administration, the North Pacific Research Board and the National Oceanic Partnership Program, which also includes funding by the Bureau of Ocean Energy Management.

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Materials provided by University of Alaska Fairbanks. Note: Content may be edited for style and length.

We put our clothes through a lot and if the smart textiles of the future are going to survive all that we throw at them, their components are going to need to be resilient.

Now, researchers from the Harvard John A. Paulson School of Engineering and Applied Sciences and the Wyss Institute for Biologically Inspired Engineering have developed an ultra-sensitive, seriously resilient strain sensor that can be embedded in textiles and soft robotic systems.

The research is published in Nature.

“Current soft strain gauges are really sensitive but also really fragile,” said Oluwaseun Araromi, a Research Associate in Materials Science and Mechanical Engineering at SEAS and the Wyss Institute and first author of the paper. “The problem is that we’re working in an oxymoronic paradigm — highly sensitivity sensors are usually very fragile and very strong sensors aren’t usually very sensitive. So, we needed to find mechanisms that could give us enough of each property.”

In the end, the researchers created a design that looks and behaves very much like a Slinky.

“A Slinky is a solid cylinder of rigid metal but if you pattern it into this spiral shape, it becomes stretchable,” said Araromi. “That is essentially what we did here. We started with a rigid bulk material, in this case carbon fiber, and patterned it in such a way that the material becomes stretchable.”

The pattern is known as a serpentine meander, because its sharp ups and downs resemble the slithering of a snake. The patterned conductive carbon fibers are then sandwiched between two prestrained elastic substrates.

The overall electrical conductivity of the sensor changes as the edges of the patterned carbon fiber come out of contact with each other, similar to the way the individual spirals of a slinky come out of contact with each other when you pull both ends. This process happens even with small amounts of strain, which is the key to the sensor’s high sensitivity.

Unlike current highly sensitive stretchable sensors, which rely on exotic materials such as silicon or gold nanowires, this sensor doesn’t require special manufacturing techniques or even a clean room. It could be made using any conductive material.

The researchers tested the resiliency of the sensor by stabbing it with a scalpel, hitting it with a hammer, running it over with a car, and throwing it in a washing machine ten times. The sensor emerged from each test unscathed.

To demonstrate its sensitivity, the researchers embedded the sensor in a fabric arm sleeve and asked a participant to make different gestures with their hand, including a fist, open palm, and pinching motion. The sensors detected the small changes in the subject’s forearm muscle through the fabric and a machine learning algorithm was able to successfully classify these gestures.

“These features of resilience and the mechanical robustness put this sensor in a whole new camp,” said Araromi.

Such a sleeve could be used in everything from virtual reality simulations and sportswear to clinical diagnostics for neurodegenerative diseases like Parkinson’s Disease.

Harvard’s Office of Technology Development has filed to protect the intellectual property associated with this project.

“The combination of high sensitivity and resilience are clear benefits of this type of sensor,” said Robert Wood, the Charles River Professor of Engineering and Applied Sciences at SEAS and senior author of the study. “But another aspect that differentiates this technology is the low cost of the constituent materials and assembly methods. This will hopefully reduce the barriers to get this technology widespread in smart textiles and beyond.”

“We are currently exploring how this sensor can be integrated into apparel due to the intimate interface to the human body it provides,” says Conor Walsh, the Paul A. Maeder Professor of Engineering and Applied Sciences at SEAS and co-author of the study. “This will enable exciting new applications by being able to make biomechanical and physiological measurements throughout a person’s day, not possible with current approaches.”

The research was co-authored by Moritz A. Graule, Kristen L. Dorsey, Sam Castellanos, Jonathan R. Foster, Wen-Hao Hsu, Arthur E. Passy, James C. Weaver, Senior Staff Scientist at SEAS and Joost J. Vlassak, the Abbott and James Lawrence Professor of Materials Engineering at SEAS.

It was funded through the university’s strategic research alliance with Tata. The 6-year, $8.4M alliance was established in 2016 to advance Harvard innovation in fields including robotics, wearable technologies, and the internet of things (IoT).

During normal viewing, we direct our eyes between objects in the three-dimensional space many times a minute. With each change, the left and right eyes will rotate, generally in the same direction, but mostly by different degrees of rotation. These unequal movements are known as disjunctive saccades.

Disjunctive saccades differ from two other eye movements: one, called conjugate saccades, where the eyes rotate in unison, and one called symmetrical vergence eye movements, where the eyes rotate in equal but opposite directions. The underlying mechanism for disjunctive saccades is not known.

Several models of eye movement predicted the existence of a population of neurons called saccade-vergence burst neurons, or SVBNs, that would produce a burst of activity solely during disjunctive saccades, while not firing during the other two types of eye movements.

The UAB researchers, led by Julie Quinet, Ph.D., hunted for these putative neurons in a region of the midbrain located near to the oculomotor nucleus called the central mesencephalic reticular formation, or cMRF. Recent anatomical studies had suggested that the cMRF might contain premotor neurons involved in the neural control of disjunctive saccades.

Using brain recordings from trained rhesus monkeys, Quinet and colleagues found and recorded 18 SVBNs in the cMRF. “To our knowledge,” said Quinet, a researcher V in the UAB Department of Ophthalmology and Visual Sciences, “no such class of cells has been reported in prior recording studies.”

This novel population of SVBNs displayed three unique characteristics that were predicted by models: 1) The neurons discharged when animals performed a disjunctive saccade; 2) The neurons remained silent during the unison eye movement called conjugate saccades and also during the eye movement when the eyes rotate in equal but opposite directions, called symmetric vergence eye movement, and; 3) The neurons burst without regard to the direction — rightward or leftward — of the disjunctive saccade. Furthermore, the bursts of spikes during disjunctive saccades were highly correlated with vergence velocity — the speed at which the eyes move toward or away from each other.

Intriguingly, half of the recorded cells increased their firing rate for convergence disjunctive saccades, while half increased their firing rate for divergence disjunctive saccades.

Quinet and colleagues say that further studies of disjunctive saccades in brain areas that may supply input to SVBNs can help explain and advance solutions to treat strabismus, a condition in which eyes do not properly align with each other while looking at an object.

The results of this study and previous studies elsewhere and at UAB, Quinet says, suggest that SVBNs could play a role in all the components of the near triad responses — lens accommodation, pupillary constriction and vergence.

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Materials provided by University of Alabama at Birmingham. Original written by Jeff Hansen. Note: Content may be edited for style and length.

Our solar system is a busy place — in addition to the large bodies we are all familiar with exist an uncountably large number of rocky asteroids and icy comets. These mostly stay put in their orbits far from Earth but many also roam around the solar system. As they do, they shed some material due to collisions, deformations or heating. Due to this, the Earth is surrounded by small particles we call interplanetary dust. By investigating the size and composition of the interplanetary dust, astronomers can indirectly investigate the activity and makeup of the parent bodies.

“When in space, interplanetary dust is practically invisible. However, around 1,000 kilograms falls to Earth every day in the form of tiny meteors which appear as bright streaks in the night sky,” said astronomer Ryou Ohsawa from the Institute of Astronomy at the University of Tokyo. “We can observe these with ground-based radar and optical instruments. Radar is useful as it can cover wide areas and gather vast readings, but optical telescopes can give more detailed information useful for our studies. So we set out to bridge this gap to boost our observational capacity.”

Ground-based radar is very good at detecting the motion of meteors, but it does not reveal much information about the mass or composition of the meteors. Optical telescopes and sensors can infer those details based on the light given off by falling meteors due to interaction with the atmosphere. However, telescopes have a limited field of view and until recently lacked the sensitivity to see faint meteors at all. Ohsawa and his team wished to imbue radar observatories with the powers of optical ones. After a few years, they have finally succeeded.

“We thought that if you could observe enough meteors simultaneously with both radar and optical facilities, details of the meteors in the optical data may correspond to previously unseen patterns in the radar data too,” said Ohsawa. “I am pleased to report this is in fact the case. We recorded hundreds of events over several years and have now gained the ability to read information about meteor mass from subtle signals in radar data.”

In 2009, 2010 and 2018, the team used the Middle and Upper Atmosphere (MU) Radar facility, operated by Kyoto University and located in Shigaraki, Shiga Prefecture, and the Kiso Observatory, operated by the University of Tokyo, on the Nagano Prefecture side of Mount Ontake. They are 173 kilometers apart, which is important: the closer the facilities, the more accurately the data from them can be correlated. MU points directly upwards, but Kiso can be angled, so it was pointed 100 km above the site of MU. The team saw 228 meteors with both facilities and this was plenty to derive a statistically reliable relationship to connect radar and optical observations.

“Data analysis was laborious,” said Ohsawa. “A sensitive instrument called the Tomo-e Gozen wide-field camera mounted to the Kiso telescope captured over a million images a night. This is too much for us to analyze manually so we developed software to automatically recognize faint meteors. From what we’ve learned here we hope to extend this project and begin using radar to investigate the composition of meteors. This could help astronomers explore comets and aspects of solar system evolution like never before.”

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Materials provided by University of Tokyo. Note: Content may be edited for style and length.