Saturday, December 29, 2018

The International Statistic of the Year

Ninety-one percent: the proportion of plastic waste that has never been recycled.

Credit: UC Santa Barbara

That figure, determined by UC Santa Barbara marine scientist Roland Geyer and published last year in the journal Science Advances, is the winner of the Royal Statistical Society’s (RSS) 2018 International Statistic of the Year.

Of all the plastic every produced, worldwide — more than 8 billion metric tons — roughly 30 percent is still in use. Of the remaining amount, Geyer and his research team found, only 9 percent has been recycled. Approximately 12 percent of plastic waste has been incinerated, but 79 percent — more than three-quarters — has been allowed to accumulate in landfills or in the natural environment. (Read more in “A Plastic Planet” on the UC Santa Barbara Current.)

“It’s very concerning that such a large proportion of plastic waste has never been recycled,” said David Spiegelhalter, RSS president and chair of the competition’s panel of judges. “The really low level of recycling has resulted in far too much waste leaching out into the world’s environment. It’s a great, growing and genuinely worldwide problem. This statistic helps to show the scale of the challenge we all face. It has rightly been named the RSS’s ‘International Statistic of the Year’ for 2018.”

Roland Geyer
Credit: Matt Perko/UC Santa Barbara

The 91 percent statistic was highlighted in the 2018 United Nations Environment report “Single-Use Plastics: A Roadmap for Sustainability,” which looks at the issue of single-use plastic and what governments, businesses and individuals have achieved at national and community levels to curb its consumption. The statistic’s inclusion in the report ultimately led the RSS nomination.

“We’re honored to receive this recognition from the Royal Statistical Society and it’s judging panel,” said Geyer. “We hope it will draw attention to the problem of plastic pollution that impacts nearly every community and ecosystem globally.” Geyer’s research team included Jenna Jambeck, an associate professor of engineering at the University of Georgia, and Kara Lavender Law, a research professor at the Sea Education Association in Woods Hole, Massachusetts.

Said Hetan Shah, RSS executive director, “We were delighted with the quality and quantity of this year’s nominations — with well over 200 received. The statistics on the list capture some of the zeitgeist of 2018 … Statistics help us make sense of the world around us, and these numbers tell us how the world continued to change in 2018.”

Founded in 1834, the RSS is a learned society for statistics, a professional body for statisticians and a non-profit organization that promotes statistics, data and evidence for the public good. The list of 2018 Statistics of the Year includes one winner from the United Kingdom, one international winner and eight “highly commended” statistics. Nominations are made by members of the public from around the world.
Contacts and sources:
Andrea Estrada
UC Santa Barbara

Nanotechnology May Make Smart Textiles More Comfortable.

Silver nanowires promise more comfortable smart textiles.

In a paper  published in NANO, researchers from the Nanjing University of Posts and Telecommunications have developed a simple, scalable and low-cost capillary-driven self-assembly method to prepare flexible and stretchable conductive fibers that have applications in wearable electronics and smart fabrics.

A simple, scalable and low-cost capillary-driven self-assembly method to prepare conductive fibers with uniform morphology, high conductivity and good mechanical strength has been developed by a team of researchers in Nanjing, China. Dr. Yi Li and Yanwen Ma, from the Key Laboratory for Organic Electronics and Information Displays, Institute of Advanced Materials (IAM) of Nanjing University of Posts and Telecommunications and his collaborators have developed a simple, scalable and low cost capillarity-driven self-assembly route to produce silver nanowires (Ag NWs) coated flexible and stretchable conductive fibers.

A simple, scalable and low-cost capillary-driven self-assembly method has been developed to prepare conductive fibers with uniform morphology, high conductivity and good mechanical strength. By coating highly conductive and flexible silver nanowires on the surfaces of yarn and PDMS fibers, high-performance fiber-shaped flexible and stretchable conductors are fabricated, which have great potential for application in wearable devices.

Credit: Yi Li

Taking advantage of the capillary action of fibers, such as cotton, nylon and polyester yarns as well as PDMS fibers, the solution containing Ag NWs is spontaneously absorbed into the capillary tunnels. Then Ag NWs are evenly coated onto the fibers through evaporation-induced flow and capillary-driven self-assembly process to form conductive fibers, which is in situ observed by the optical microscopic measurement. The fabricated flexible and stretchable conductor exhibits uniform morphology, high conductivity and good mechanical strength, which is promising for the application in wearable electronics and smart fabrics.

Conventional conductive fibers are metal wires such as stainless steel and copper wires, as well as the metal film coated yarn. These conductive fibers are stiff and brittle, not meeting the demand of flexibility and comfortability for smart textiles.

Smart textiles with electronic devices such as sensor, light emitting diode, transistor, battery and supercapacitors integrated into fabrics have drawn considerable attention. Conductive fibers and yarns, with the function of connecting various electronic devices, play a key role in smart textiles system. Recently, conductive nanomaterials such as metal nanomaterials, carbon nanotubes and graphene with high conductivity, good mechanical properties, feasibility of large-scale production and solution-process, have become a new type of fundamental materials for conductive fibers. Great efforts have been made to engineer conductive nanomaterials into conductive fibers by various technologies such as vapor deposition, electrospinning and spray coating methods. Despite these promising progresses, the facile, large-scale and cost-effective fabrication of conductive fibers with high flexibility and good electrical conductivity is still a challenge.

This work was partially funded National Natural Science Foundation of China and Keypoint Research and Invention Program of Jiangsu Province.

Corresponding authors for this study in NANO are Yi Li and Yanwen Ma.

For more insight into the research described, readers are invited to access the paper on NANO.

NANO is an international peer-reviewed monthly journal for nanoscience and nanotechnology that presents forefront fundamental research and new emerging topics. It features timely scientific reports of new results and technical breakthroughs and publishes interesting review articles about recent hot issues.

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Contacts and sources:
Tay Yu Shan
World Scientific Publishing

Citation: Capillarity-Driven Self-Assembly of Silver Nanowires-Coated Fibers for Flexible and Stretchable Conductor Yi Li, Jun Chen, Xiao Han, Yinghui Li, Ziqiang Zhang and Yanwen Ma

Reliable Tropical Weather Pattern to Change in a Warming Climate

The Madden-Julian Oscillation's precipitation variations are likely to increase in intensity under a warmer climate, while wind variations are likely to increase at a slower rate

Every month or two, a massive pulse of clouds, rainfall and wind moves eastward around the Earth near the equator, providing the tropics their famous thunderstorms.

This band of recurring weather, first described by scientists in 1971, is called the Madden-Julian Oscillation. It has profound effects on weather in distant places, including the United States. Atmospheric scientists have long studied how the Madden-Julian Oscillation modulates extreme weather events across the globe, from hurricanes to floods to droughts.

Current climate is represented in (a), and a warmer climate in (b). As the climate warms, the mean vertical gradient in water vapor (blue) increases. Tropospheric temperature (orange shading) will also increase more than the lower atmosphere.

Credit: Eric Maloney/Colorado State University

As human activities cause the Earth's temperature to increase, reliable, well-studied weather patterns like the Madden-Julian Oscillation will change too, say researchers at Colorado State University.

Eric Maloney, professor in the Department of Atmospheric Science, has led a new study published in Nature Climate Change that attributes future changes in the behavior of the Madden-Julian Oscillation to anthropogenic global warming. Maloney and co-authors used data from six existing climate models to synthesize current views of such changes projected for the years 2080-2100.

Their analysis reveals that while the Madden-Julian Oscillation's precipitation variations are likely to increase in intensity under a warmer climate, wind variations are likely to increase at a slower rate, or even decrease. That's in contrast to the conventional wisdom of a warming climate producing a more intense Madden-Julian Oscillation, and thus an across-the-board increase in extreme weather.

"In just looking at precipitation changes, the Madden-Julian Oscillation is supposed to increase in strength in a future climate," Maloney said. "But one of the interesting things from our study is that we don't think this can be generalized to wind as well."

Atmospheric science relies on weather patterns like the Madden-Julian Oscillation to inform weather prediction in other areas of Earth. For example, atmospheric rivers, which are plumes of high atmospheric water vapor that can cause severe flooding on the U.S. west coast, are strongly modulated by certain phases of the Madden-Julian Oscillation.

According to Maloney's work, the Madden-Julian Oscillation's impact on remote areas may gradually decrease. Degradation in the oscillation's wind signal may thus diminish meteorologists' ability to predict extreme weather events. In particular, preferential warming of the upper troposphere in a future, warmer climate is expected to reduce the strength of the Madden-Julian Oscillation circulation.

Maloney and colleagues hope to continue studying the Madden-Julian Oscillation using a broader set of climate models to be used in the next Intergovernmental Panel on Climate Change assessment.

Contacts and sources:
Anne Manning
Colorado State University

Citation:  Madden–Julian oscillation changes under anthropogenic warming Eric D. Maloney, Ángel F. Adames & Hien X. Bui Nature Climate Change volume 9, pages 26–33 (2019)

UniqueTechnique Paves Way for Creation of Protein Nanomachines and Engineering of New Cell Functions.

Proteins have now been designed in the lab to zip together in much the same way that DNA molecules zip up to form a double helix. The technique, whose development was led by University of Washington School of Medicine scientists, could enable the design of protein nanomachines that can potentially help diagnose and treat disease, allow for the more exact engineering of cells and perform a wide variety of other tasks.

“For any machine to work, its parts must come together precisely,” said Zibo Chen, the lead author of the paper and a UW graduate student in biochemistry. “This technique makes it possible for you to design proteins so they come together exactly how you want them to.”

Proteins designed on computer and tested in the lab look a lot like DNA.
Illustration of paired proteins that look like a DNA model
Institute for Protein Design

The findings were published Dec. 19 in the journal Nature. Here is the paper indexed under synthetic biology. The research was performed at the Institute for Protein Design, directed by David Baker, UW professor of biochemistry and a Howard Hughes Medical Institute investigator.

In the past, researchers interested in designing biomolecular nanomachines have often used DNA as a major component. This is because DNA strands come together and form hydrogen bonds to create DNA’s double helix, but only if their sequences are complementary.

The team developed new protein design algorithms that produce complementary proteins that precisely pair with each other using the same chemical language of DNA.

“This is a first-of-its-kind breakthrough," Chen said. "What we’re doing is computationally designing these hydrogen-bond networks so that each protein pair has a unique complementary sequence. There is only one way for them to come together and they do not cross-react with proteins from other pairs."

“Engineering cells to do new tasks is the future of medicine and biotechnology, whether that’s engineering bacteria to make energy or clean up toxic waste or creating immune cells that attack cancers,” said Scott Boyken, another author of the paper and a UW postdoctoral researcher. “This technique provides scientists a precise, programmable way to control how protein machines interact, a key step towards achieving these new tasks. We have opened a major door to protein nanomaterial design.”

In their study, researchers used a computer program developed in the Baker lab, called Rosetta. The program takes advantage of the fact that the shape an amino acid chain will assume is driven by the forces of attraction and repulsion between the amino acids of the chain and the fluid in which the chain is immersed. By calculating the shape that best balances out these forces so that the chain achieves its lowest overall energy level, the program can predict the shape a given amino acid chain will likely take.

This work was done in collaboration with researchers led by Vicki Wysocki at Ohio State University and by Nikolaos Sgourakis at the University of California, Santa Cruz. The work used support from the Structurally Integrated Biology for Life Sciences program with small angle X-ray scattering and the Advanced Light Source resources at the Lawrence Berkeley National Laboratory, as well as the Argonne Leadership Computing Facility at the Argonne National Laboratory.Contacts and sources:
Denise BloughThe Ohio State University


Collecting Clean Water from Air, Inspired by Desert Life

Humans can get by in the most basic of shelters, can scratch together a meal from the most humble of ingredients. But we can't survive without clean water. And in places where water is scarce--the world's deserts, for example--getting water to people requires feats of engineering and irrigation that can be cumbersome and expensive.

A pair of new studies from researchers at The Ohio State University offers a possible solution, inspired by nature.

"We thought: 'How can we gather water from the ambient air around us?'" said Bharat Bhushan, Ohio Eminent Scholar and Howard D. Winbigler Professor of mechanical engineering at Ohio State. "And so, we looked to the things in nature that already do that: the cactus, the beetle, desert grasses."

New studies show options for gathering water from fog, condensation
Credit: The Ohio State University

Their findings were published Dec. 24 in the journal Philosophical Transactions of the Royal Society. The works were co-authored with Ohio State Ph.D. student Dev Gurera and with Ohio State engineering researcher Dong Song.

Bhushan's work focuses on finding nature-inspired solutions to societal problems. In this case, his research team looked to the desert to find life that survives despite limited access to water.

The cactus, beetle and desert grasses all collect water condensed from nighttime fog, gathering droplets from the air and filtering them to roots or reservoirs, providing enough hydration to survive.

Drops of water collect on wax-free, water-repellant bumps on a beetle's back, then slide toward the beetle's mouth on the flat surface between the bumps. Desert grasses collect water at their tips, then channel the water toward their root systems via channels in each blade. A cactus collects water on its barbed tips before guiding droplets down conical spines to the base of the plant.

Bhushan's team studied each of these living things and realized they could build a similar--albeit larger--system to allow humans to pull water from nighttime fog or condensation.

They started studying the ways by which different surfaces might collect water, and which surfaces might be the most efficient. Using 3D printers, they built surfaces with bumps and barbs, then created enclosed, foggy environments using a commercial humidifier to see which system gathered the most water.

They learned that conical shapes gather more water than do cylindrical shapes--"which made sense, given what we know about the cactus," Bhushan said. The reason that happens, he said, is because of a physics phenomenon called the Laplace pressure gradient. Water gathers at the tip of the cone, then flows down the cone's slope to the bottom, where a reservoir is waiting.

Grooved surfaces moved water more quickly than ungrooved surfaces--"which seems obvious in retrospect, because of what we know about grass," Bhushan said. In the research team's experiments, grooved surfaces gathered about twice as much water as ungrooved surfaces.

The materials the cones were made out of mattered, too. Hydrophilic surfaces--those that allowed water to bead up rather than absorbing it--gathered the most water.

"The beetle's surface material is heterogeneous, with hydrophilic spots surrounded by hydrophobic regions, which allows water to flow more easily to the beetle's mouth," Bhushan explained.

The research team also experimented on a structure that included multiple cones, and learned that more water accumulated when water droplets could coalesce between cones that were one or two millimeters apart. The team is continuing those experiments, Bhushan said.

The work so far has been done on a laboratory-only level, but Bhushan envisions the work scaled up, with structures in the desert that could gather water from fog or condensation. That water, he thinks, could supplement water from public systems or wells, either on a house-by-house basis, or on a community-wide basis.

There is precedent for the idea: In areas around the world, including the Atacama Desert in Chile, large nets capture water from fog and collect it in reservoirs for farmers and others to use. Those nets might not be the most efficient way of harnessing water from the air, Bhushan believes.

"Water supply is a critically important issue, especially for people of the most arid parts of the world," Bhushan said. "By using bio-inspired technologies, we can help address the challenge of providing clean water to people around the globe, in as efficient a way as possible."

Contacts and sources:
Laura ArenschieldThe Ohio State University

New Metamaterial to Harness Power of Light: Technology Will Improve Optical Computing, Telecommunications

Scientists have long known that synthetic materials - called metamaterials - can manipulate electromagnetic waves such as visible light to make them behave in ways that cannot be found in nature. That has led to breakthroughs such as super-high resolution imaging. Now, UMass Lowell is part of a research team that is taking the technology of manipulating light in a new direction.

The team - which includes collaborators from UMass Lowell, King's College London, Paris Diderot University and the University of Hartford -has created a new class of metamaterial that can be "tuned" to change the color of light. This technology could someday enable on-chip optical communication in computer processors, leading to smaller, faster, cheaper and more power-efficient computer chips with wider bandwidth and better data storage, among other improvements. On-chip optical communication can also create more efficient fiber-optic telecommunication networks.

This illustration shows two incoming (red) photons being converted into one reflected (green) photon as result of light interaction with the nanowire structure in the metamaterial. The nanowires are about 100 nanometers apart from center to center, which is about one-fifty-thousandth the diameter of human hair.
Credit: University of Massachusetts Lowell

"Today's computer chips use electrons for computing. Electrons are good because they're tiny," said Prof. Viktor Podolskiy of the Department of Physics and Applied Physics, who is the project's principal investigator at UMass Lowell. "However, the frequency of electrons is not fast enough. Light is a combination of tiny particles, called photons, which don't have mass. As a result, photons could potentially increase the chip's processing speed."

By converting electrical signals into pulses of light, on-chip communication will replace obsolete copper wires found on conventional silicon chips, Podolskiy explained. This will enable chip-to-chip optical communication and, ultimately, core-to-core communication on the same chip.

"The end result would be the removal of the communication bottleneck, making parallel computing go so much faster," he said, adding that the energy of photons determines the color of light. "The vast majority of everyday objects, including mirrors, lenses and optical fibers, can steer or absorb these photons. However, some materials can combine several photons together, resulting in a new photon of higher energy and of different color."

Podolskiy says enabling the interaction of photons is key to information processing and optical computing. "Unfortunately, this nonlinear process is extremely inefficient and suitable materials for promoting the photon interaction are very rare."

Podolskiy and the research team have discovered that several materials with poor nonlinear characteristics can be combined together, resulting in a new metamaterial that exhibits desired state-of-the-art nonlinear properties.

"The enhancement comes from the way the metamaterial reshapes the flow of photons," he said. "The work opens a new direction in controlling the nonlinear response of materials and may find applications in on-chip optical circuits, drastically improving on-chip communications."

Contacts and sources:
Christine Gillette and Nancy Cicco
University of Massachusetts Lowell

How 'Dry January' Is the Secret to Better Sleep, Saving Money and Losing Weight

New research from the University of Sussex shows that taking part in Dry January - abstaining from booze for a month - sees people regaining control of their drinking, having more energy, better skin and losing weight. They also report drinking less months later.

Credit: Alcohol Change UK

The research, led by Sussex psychologist Dr Richard de Visser, was conducted with over 800 people who took part in Dry January in 2018. The results show that Dry January participants are still drinking less in August. They reported that:
  • drinking days fell on average from 4.3 to 3.3 per week;
  • units consumed per drinking day dropped on average from 8.6 to 7.1;
  • frequency of being drunk dropped from 3.4 per month to 2.1 per month on average.

Dr Richard de Visser, Reader in Psychology at the University of Sussex, said:"The simple act of taking a month off alcohol helps people drink less in the long term: by August people are reporting one extra dry day per week. There are also considerable immediate benefits: nine in ten people save money, seven in ten sleep better and three in five lose weight.

"Interestingly, these changes in alcohol consumption have also been seen in the participants who didn't manage to stay alcohol-free for the whole month - although they are a bit smaller. This shows that there are real benefits to just trying to complete Dry January."

The University of Sussex research showed that:
  • 93% of participants had a sense of achievement;
  • 88% saved money;
  • 82% think more deeply about their relationship with drink;
  • 80% feel more in control of their drinking;
  • 76% learned more about when and why they drink;
  • 71% realised they don't need a drink to enjoy themselves;
  • 70% had generally improved health;
  • 71% slept better;
  • 67% had more energy;
  • 58% lost weight;
  • 57% had better concentration;
  • 54% had better skin.

Dr Richard de Visser's findings come from three self-completed online surveys: 2,821 on registering for Dry January; 1,715 in the first week of February; and 816 participants in August.

A new YouGov poll undertaken for Alcohol Change UK showed that one in ten people who drink - an estimated 4.2 million people in the UK - are already planning to do Dry January in 2019.

Dr Richard Piper, CEO of Alcohol Change UK, said:

"Put simply, Dry January can change lives. We hear every day from people who took charge of their drinking using Dry January, and who feel healthier and happier as a result.

"The brilliant thing about Dry January is that it's not really about January. Being alcohol-free for 31 days shows us that we don't need alcohol to have fun, to relax, to socialise. That means that for the rest of the year we are better able to make decisions about our drinking, and to avoid slipping into drinking more than we really want to.

"Many of us know about the health risks of alcohol - seven forms of cancer, liver disease, mental health problems - but we are often unaware that drinking less has more immediate benefits too. Sleeping better, feeling more energetic, saving money, better skin, losing weight... The list goes on. Dry January helps millions to experience those benefits and to make a longer-lasting change to drink more healthily."

Signing up for Dry January increases the chance that you'll get the most out of the month. You can download Try Dry: The Dry January App to track your units, money and calories saved, plus many more features. Or you can sign up at for regular support emails with tips and tricks from experts and others like you.

Contacts and sources:
Anna FordUniversity of Sussex


Groups of Pilot Whales Have Their Own Dialects

In humans, different social groups, cities, or regions often have distinct accents and dialects. Those vocal traits are not unique to us, however. A new study from the Woods Hole Oceanographic Institution (WHOI) has found that short-finned pilot whales living off the coast of Hawai’i have their own sorts of vocal dialects, a discovery that may help researchers understand the whales’ complex social structure. The study was published on Dec. 14, 2018, in the journal Behavioral Ecology and Sociobiology.

“These groups of pilot whales all use the same habitat. The fact that they have different vocal repertoires means that they’re purposely not associating with each other,” says Amy Van Cise, a Postdoctoral Scholar at WHOI and lead author on the study. “It’s sort of like if you’ve got hipsters and prep kids in the same high school—each group has different slang. They identify themselves with certain speech to maintain that separation.”

Credit: Photo by Amy Van Cise, Woods Hole Oceanographic Institution, NMFS permit #15530

This finding could be especially important for understanding the species, since relatively little is currently known about their social behavior.

“On a broad-scale they are understudied, mainly because of where they spend their time,” says biologist Robin Baird of the Cascadia Research Consortium, a co-author on the paper. “Hawai’i is one of the only locations in the U.S. where you can fairly quickly and easily get to areas where you can find pilot whales, while staying in good working conditions.”

In a previous 15-year study of the Hawai’ian whales, Baird and colleagues were able to photograph, identify, and categorize groups of whales, creating a database of associations. The researchers also took tiny biopsies of skin from the back of each whale they approached to gather genetic information.

Based on that data, Van Cise found that the lowest and smallest level of organization, called a “unit,” of pilot whales, appears to be made up of a handful of directly-related individuals. Those units combine to form “clusters”—essentially extended family—and multiple families together make up a “community” of the whales.

This study builds on Van Cise’s prior work. Over several years, she and Baird’s team took a small boat off the coast of Hawai‘i and Kaua‘i Islands in search of pilot whales, identified individual whales, and recorded their calls with a specialized underwater microphone. She also continued taking genetic samples from the animals. Once finished, Van Cise and a team of volunteers painstakingly categorized individual types of whale calls on the recordings, sorting them into distinct groups.

This spectrogram shows a visual representation of three different pilot whale calls. The green stripe-like lines represent audio frequencies in each whale's ‘dialect', which subtly change from one group to another.

» Listen to whale calls

“That let us effectively make a map of vocal repertoire that we could superimpose onto a map of the whales’ social structure,” she says. “If two social groups sound similar to each other acoustically, that likely means that that’re that they’re communicating with each other regularly, using similar habitats or hunting grounds and foraging habits. This gives us a better sense of the social ties between whale groups. In the long term, that could help us understand both their genetic diversity and their evolution.”

That last part is especially important, Van Cise notes. In each family of whales, the genetic diversity between individuals isn’t large—children by necessity share many of their genes with their parents. Across the entire whale population, however, it’s a different story. For that reason, she says, it’ll be essential to conserve pilot whales at family level, rather than focusing on individuals.

The groups of pilot whales all use the same habitat, but have different vocal repertoires. This means that they’re purposely not associating with each other, says WHOI researcher Amy Van Cise. 
Photo by Amy Van Cise, Woods Hole Oceanographic Institution. NMFS permit #15530 to Robin W Baird, Cascadia Research Collective.

“Although pilot whales are not currently endangered, they still face a number of threats. They’re hunted in many countries around world, and we think they may be sensitive to navy sonar or other human-made noise in ocean,” she says. “When you hear of mass whale stranding incidents on a beach, it’s often pilot whales, because the entire social group strands. That’s the strength of the social tie—if leader of a group beaches itself, all the animals in group will beach themselves.”

Also collaborating on the study were Sabre D. Mahaffy of Cascadia Research Collective and Jay Barlow of the NOAA Southwest Fisheries Science Center. Funding for the study was provided by grants from the Pacific Islands Fisheries Science Center and Office of Naval Research, as well as Commander, Pacific Fleet. SoundTrap acoustic recording equipment was purchased with funding from the SIO/NSF IGERT fellowship program. DMON data collection was funded by the Office of Naval Research, award numbers N000141110612 and N00014-15-1-2299. The WHOI Marine Mammal Center and the Sawyer and Penzance Endowed Funds also provided funding.

The Woods Hole Oceanographic Institution is a private, non-profit organization on Cape Cod, Mass., dedicated to marine research, engineering, and higher education. Established in 1930 on a recommendation from the National Academy of Sciences, its primary mission is to understand the oceans and their interaction with the Earth as a whole, and to communicate a basic understanding of the oceans’ role in the changing global environment.

Contacts and sources:
Woods Hole Oceanographic Institution

Citation: Song of my people: dialect differences among sympatric social groups of short-finned pilot whales in Hawai’i.
Amy M. Van Cise, Sabre D. Mahaffy, Robin W. Baird, T. Aran Mooney, Jay Barlow. Behavioral Ecology and Sociobiology, 2018; 72 (12) DOI: 10.1007/s00265-018-2596-1

NASA’s First Mission to the Trojan Asteroids

In science fiction, explorers can hop in futuristic spaceships and traverse half the galaxy in the blink of a plot hole. However, this sidelines the navigational acrobatics required in order to guarantee real-life mission success.

In 2021, the feat of navigation that is the Lucy mission will launch. To steer Lucy towards its targets doesn’t simply involve programming a map into a spacecraft and giving it gas money – it will fly by six asteroid targets, each in different orbits, over the course of 12 years.

This diagram illustrates Lucy's orbital path. The spacecraft’s path (green) is shown in a frame of reference where Jupiter remains stationary, giving the trajectory its pretzel-like shape. After launch in October 2021, Lucy has two close Earth flybys before encountering its Trojan targets. In the L4 cloud Lucy will fly by (3548) Eurybates (white), (15094) Polymele (pink), (11351) Leucus (red), and (21900) Orus (red) from 2027-2028. After diving past Earth again Lucy will visit the L5 cloud and encounter the (617) Patroclus-Menoetius binary (pink) in 2033. As a bonus, in 2025 on the way to the L4, Lucy flies by a small Main Belt asteroid, (52246) Donaldjohanson (white), named for the discoverer of the Lucy fossil. After flying by the Patroclus-Menoetius binary in 2033, Lucy will continue cycling between the two Trojan clouds every six years.

Credits: Southwest Research Institute

Lucy’s destination is among Jupiter’s Trojan asteroids, clusters of rocky bodies almost as old as the Sun itself, and visiting these asteroids may help unlock the secrets of the early solar system. Lucy will encounter a Main Belt asteroid in 2025, where it will conduct a practice run of its instruments before encountering the first four Trojan targets from 2027-2028. In 2033, Lucy will end its mission with a study of a binary system of two Trojans orbiting each other.

Getting the spacecraft where it needs to go is a massive challenge. The solar system is in constant motion, and gravitational forces will pull on Lucy at all times, especially from the targets it aims to visit. Previous missions have flown by and even orbited multiple targets, but none so many as will Lucy.

Scientists and engineers involved with trajectory design have the responsibility of figuring out that route, under Flight Dynamics Team Leader Kevin Berry of NASA’s Goddard Space Flight Center in Greenbelt, Maryland. One such engineer is Jacob Englander, the optimization technical lead for the Lucy mission. “There are two ways to navigate a mission like Lucy,” he said. “You can either burn an enormous amount of propellant and zig-zag your way around trying to find more targets, or you can look for an opportunity where they just all happen to line up perfectly.” To visit these aligned targets, the majority of Lucy’s high-speed lane changes will come from gravity assists, with minimal use of fueled tweaks.

Though Lucy is programmed to throw itself out into a celestial alignment that will not occur for decades, it cannot be left to its own devices. Once the spacecraft begins to approach its asteroid targets, optical navigation is the next required step.

“OpNav,” as optical navigation technical lead Coralie Adam refers to it, is the usage of imagery from the on-board cameras to determine Lucy’s position relative to the target. This is a useful measurement used by the navigation team to tweak Lucy’s route and ensure it stays on the nominal flyby path. Adam works in Simi Valley, California, with KinetX, the company NASA selected to conduct Lucy’s deep space navigation.

By using the communications link from the spacecraft to Earth, Adam said, the Lucy team gets information about the spacecraft’s location, direction and velocity. The spacecraft takes pictures and sends them down to Earth, where Adam and other optical navigators use software to determine where the picture was taken based on the location of stars and the target. The orbit determination team uses this data along with data from the communications link to solve for where the spacecraft is and where it is expected to be, relative to the Trojans. The team then designs a trajectory correction maneuver to get Lucy on track. “The first maneuver is tiny,” said navigation technical lead Dale Stanbridge, who is also of KinetX. “But the second one is at 898 meters per second. That’s a characteristic of Lucy: very large delta V maneuvers.” Delta V refers to the change in speed during the maneuver.

Communicating all of these navigation commands with Lucy is a process all on its own. “Lockheed Martin sends the commands to the spacecraft via the Deep Space Network,” Adam said. “What we do is we work with Lockheed and the Southwest Research Institute, where teams are sequencing the instruments and designing how the spacecraft is pointed, to make sure Lucy takes the pictures we want when we want them.”

“The maneuvers to correct Lucy’s trajectory are all going to be really critical because the spacecraft must encounter the Trojan at the intersection of the spacecraft and Trojan orbital planes,” Stanbridge said. “Changing the spacecraft orbital plane requires a lot of energy, so the maneuvers need to be executed at the optimal time to reach to next body while minimizing the fuel cost.”

While Lucy is conducting deep space maneuvers to correct its trajectory toward its targets, communications with the spacecraft are sometimes lost for brief periods. “Blackout periods can be up to 30 minutes for some of our bigger maneuvers,” Stanbridge said. “Other times you could lose communications would be when, for example, the Sun, comes between the Earth tracking station and the spacecraft, where the signal would be degraded by passing through the solar plasma.”

Losing contact isn’t disastrous, though. “We have high-fidelity predictions of the spacecraft trajectory which are easily good enough to resume tracking the spacecraft when the event causing a communication loss is over,” Stanbridge said.

What route will Lucy take once its mission is complete, nearly 15 years from now? “We’re just going to leave it out there,” Englander said. “We did an analysis to see if it passively hits anything, and looking far into the future, it doesn’t.” The Lucy team has given the spacecraft a clear path for thousands of years, long after Lucy has rewritten the textbooks on our solar system’s history.

The Lucy mission is led by Principal Investigator Dr. Hal Levison from Southwest Research Institute in Boulder, Colorado. NASA Goddard in Greenbelt, Maryland, manages the mission. Lockheed Martin Space in Denver will build the spacecraft and conduct mission operations.

For more information about NASA's Lucy mission, visit:

Contacts and sources:
Tamsyn Brann
NASA’s Goddard Space Flight Center

Strong Interactions Produce a Dance Between Light and Sound

Light and high-frequency acoustic sound waves in a tiny glass structure can strongly couple to one another and perform a dance in step.

A team of researchers from Imperial College London, the University of Oxford, and the National Physical Laboratory have experimentally achieved a long-standing goal to demonstrate the so-called “strong-coupling regime” between light and high-frequency acoustic vibrations.

The team’s research will have impact for classical- and quantum-information processing and even testing quantum mechanics at large scales. The details of their research are published today in the prestigious journal Optica.

Light (shown in orange) is injected into an optical microresonator via a tapered optical fibre. The light circulates many thousands of times inside the structure and couples strongly to high-frequency acoustic waves

Central to the team’s research are 'whispering-gallery-mode resonances' where light bounces many times around the surface of a tiny round glass structure shown in the figure above.

This phenomenon is named after an effect that was observed in St Paul’s cathedral in the nineteenth century, where one could whisper along the wall of the round gallery building and be heard on the other side.

"It is fascinating that these glass ring resonators can store excessive amounts of light, which can 'shake' the molecules in the material and generate acoustic waves," said project co-author Dr Pascal Del’Haye of the National Physical Laboratory.
Using 'whispering galleries'

As the light circulates around the circumference of the glass structure it interacts with an 11 GHz acoustic vibration that causes light to be scattered in the reverse direction. This interaction allows energy to be swapped between the light and sound at a certain rate. However, both the light- and the sound-fields will decay due to friction-like processes, preventing the two from dancing in step.

The team overcame this challenge by utilizing two such whispering-gallery-mode resonances and achieved a coupling rate that is larger than these friction-like processes, allowing the signatures of the light-sound dance to be observed.

Lead author of the project, Georg Enzian at the University of Oxford, said: “Achieving this strong-coupling regime was a thrilling moment for us.” Professor Ian Walmsley, co-author of the project, and Provost of Imperial College London, said: “I’m excited about the near- and longer-term-prospects for this new experimental platform.”

Looking ahead, the team are now preparing the next generation of these experiments that will operate at temperatures close to absolute zero. “This will allow highly sensitive quantum mechanical behaviour to be explored and utilized for the development of quantum technologies,” said principal investigator of the project, Dr Michael Vanner from the Quantum Measurement Lab at Imperial College London.

Contacts and sources:
Michael Vanner
Imperial College London

Citation: 'Observation of Brillouin optomechanical strong coupling with an 11 GHz mechanical mode'
G. Enzian, M. Szczykulska, J. Silver, L. Del Bino, S. Zhang, I. A. Walmsley, P. Del’Haye, M. R. Vanner.Optica, 2018; 6 (1): 7 DOI: 10.1364/OPTICA.6.000007

VA Study Yields New Insight on How Memory Works

Two VA researchers have explored how memory is tied to the hippocampus, with findings that will expand scientists’ understanding of how memory works.

Drs. Christine N. Smith and Larry R. Squire, both with the VA San Diego Healthcare System and the University of California, San Diego, found that declarative memory—recalling facts and events—depends on conscious knowledge of what has been learned. The finding helps explain how the hippocampus controls the process of memory. They also showed that conscious knowledge is compromised in patients with damage to the hippocampus.

One pair of scenes used in Smith and Squire’s experiment showed a moving truck parked in front of a house. In the bottom image, the worker at the back of the truck has been removed.

 Images courtesy of Dr. Christine Smith

Smith sums up the findings by saying, “Our study shows that awareness is a key feature of declarative memory.”

The results appeared in the Nov. 20, 2018, issue of the Proceedings of the National Academy of Sciences.

Testing different theories of memory

Past research has shown that damage to the medial temporal lobe (MTL), the brain region that contains the hippocampus, can cause problems with declarative memory. This type of memory, the ability to remember information about past facts and events, has been linked to the hippocampus. It is expressed through direct recollection. Another type of memory—nondeclarative—refers to skill and habit learning, as well as and other types of learning, that are based on performance rather than recollection. Nondeclarative memory does not seem to be affected by MTL damage. For example, a person with MTL damage may still remember how to ride a bike, but might not remember what he or she did yesterday.

While scientists know that the hippocampus is involved in declarative but not nondeclarative memory, how exactly the hippocampus operates during memory acquisition is not well-understood. According to Squire: “A central issue for understanding memory and memory disorders is the matter of classification. What kinds of memory are there, what are the characteristics of each kind, and what brain systems are important for each kind?”

One theory is that declarative memory is linked to conscious knowledge, or awareness of what has been learned. Another theory suggests that memory is dependent on how the brain processes information, rather than on conscious knowledge. For example, the second theory suggests that the MTL is needed when learning associations of relationships between items, regardless of whether the person is aware of what he or she has learned.
Experiment included patients with amnesia

To test these two competing theories, Smith and Squire recruited five memory-impaired patients with MTL lesions. The patients, with an average age of 63, had amnesia from different causes. Two became amnesic after a drug overdose and associated respiratory failure, one suffered ischemia (lack of blood to the brain) because of kidney failure and toxic shock syndrome, one had viral encephalitis, and one became amnesic with no known cause. Brain scans showed that these patients had smaller-than-normal hippocampus volume. The researchers also recruited six healthy people to serve as controls.

They assessed participants’ memories using something called the manipulation effect. Participants are shown a picture they are familiar with that has either been altered in some way or remains the same. According to the manipulation effect, people will spend more time looking at the section of a picture that has been changed than at the same section of an unaltered picture. But research has shown that the manipulation effect occurs only when participants know that a picture has been altered.

For the experiment, participants were shown 24 scenes for five seconds each. After a short break, they were shown the scenes again. After another break, they were shown the same 24 scenes, except that 12 had been changed and 12 remained the same. Changes were either an item being added to the scene or an item being removed. For example, in a scene of a moving truck in front of a building, the first picture showed a worker with a cart while in the second picture the worker had been removed.

The process was repeated with 24 different scenes in a second session. A computer tracked eye movements to record where in the pictures participants were looking.

Drs. Christine Smith and Larry Squire study memory and learning. On the shelf behind Squire is a replica of a sea horse. The brain’s hippocampus—crucial in memory—is named based on the ancient Greek term for sea horse. 
Photo courtesy of Dr. Christine Smith

During the third round, participants were told to look for possible changes. They were then asked to state whether each scene was the same or changed, and to rank their confidence in that answer. Finally, participants were shown the changed scenes again and asked to describe what was changed and identify where in the picture the change occurred.
Huge gap in results between patients and healthy controls

The results showed that patients with MTL lesions were “markedly impaired” at telling which scenes were changed. Specifically, control participants correctly identified an average of 16.5 out of 24 of the changed scenes, and 20.5 of the unchanged scenes. Patients identified only 8.4 changes and 18.4 repeated scenes. Controls were also more confident in their answers when they were correct than when they were incorrect, while patients showed the same level of confidence in correct and incorrect answers.

Patients were able to correctly identify a scene as changed, describe the change, and locate the section of the image that changed for only10.8 percent of the altered images. Controls did this for 60.4 percent of the images. Getting all three aspects of the change right was termed “robust knowledge.”

Both controls and patients directed their eyes toward the change only when they had robust knowledge of the change. This showed that the manipulation effect is a function of conscious memory, according to Smith and Squire. This eye movement effect suggests that conscious knowledge is an important aspect of declarative memory, and that the hippocampus supports the acquisition of this type of memory.

Smith explains the eye-movement data in this way: “When memory-impaired patients occasionally succeed at remembering a past event (measured in their eye movements), they also consciously remember the event. When the patients failed to remember (and eye movements showed no recognition), they were unaware of the past event. Our findings suggest that awareness of the past is a crucial and consistent feature of the kind of memory that depends on the hippocampus”

According to Squire, adding to the understanding of how memory works could help improve how doctors diagnose and treat memory problems. “Scientists often say that we want to fix the car but it will help to know how the car works. As we learn more about memory, we move closer to being able to detect, prevent, and treat diseases and disorders that affect memory,” he explains.

The work was supported by VA and the National Institute of Mental Health.

Contacts and sources:
Tristan Horrom 
Veterans Affairs Research Communications
Citation:  Awareness of what is learned as a characteristic of hippocampus-dependent memory.
Christine N. Smith, Larry R. Squire. Proceedings of the National Academy of Sciences, 2018; 115 (47): 11947 DOI: 10.1073/pnas.1814843115

How the Brain Enables Us to Rapidly Focus Attention

Queensland Brain Institute (QBI) researchers have discovered a key mechanism in the brain that may underlie our ability to rapidly focus attention.

Our brains are continuously bombarded with information from the senses, yet our level of vigilance to such input varies, allowing us to selectively focus on one conversation and not another.

Professor Stephen Williams of the Queensland Brain Institute at UQ explains, “If we want to give our full concentration, something happens in the brain to enable us to focus and filter out distractions.”

A spotlight brings into focus the distal dendrites of a neocortical layer 5 pyramidal neuron (gold) amongst a sea of cholinergic axons (green), an allegory of the transformation of dendritic computations in the output neurons of the neocortex produced by the optogenetic activation of the cholinergic modulatory system.
A spotlight brings into focus the distal dendrites of a neocortical layer 5 pyramidal neuron (gold) amongst a sea of cholinergic axons (green), an allegory of the transformation of dendritic computations in the output neurons of the neocortex produced by the optogenetic activation of the cholinergic modulatory system. Artwork by Lee Fletcher.
 Credit:  Artwork by Lee Fletcher, Queensland Brain Institute, The University of Queensland.

“There must be a mechanism that signals the thing we want to focus on.”

However, this mechanism is not well understood, he says.

Research has shown that the electrical activity of the neocortex of the brain changes, when we focus our attention. Neurons stop signalling in sync with one another and start firing out of sync.

This is helpful, says Williams, because it allows individual neurons to respond to sensory information in different ways. Thus, you can focus on a car speeding down the road or on what a friend is saying in a crowded room.

It’s known that the cholinergic system in the brain plays an important role in triggering this desynchronisation.

The cholinergic system consists of clusters of special neurons that synthesise and release a signalling molecule called acetylcholine, he explains, and these clusters make far reaching connections throughout the brain.

Not only does this cholinergic system act like a master switch, but mounting evidence suggests it also enables the brain to identify which sensory input is the most salient – i.e. worthy of attention – at any given moment and then shine a spotlight on that input.

“The cholinergic system broadcasts to the brain, ‘this thing is really important to be vigilant to’,” says Williams.

He adds that the cholinergic system has been proposed to have a far-reaching impact on our cognitive abilities.

“Destruction of the cholinergic system in animals profoundly degrades cognition, and the formation of memory,” he says.

“Importantly, in humans a progressive degeneration of the cholinergic system occurs in devastating diseases that blunt cognition and memory, such as Alzheimer’s disease.”

But precisely which neurons in the cortex are being targeted by this master switch and how it’s able to influence their function was unknown.

Williams and QBI researcher Lee Fletcher wondered if layer 5 B-pyramidal neurons, the ‘output’ neurons of the neocortex, might be involved, because they are intimately involved in how we perceive the world.

“The output neurons of the neocortex perform computations that are thought to underlie our perception of the world,” says Williams.

Williams and Fletcher wanted to know if the cholinergic system is able to influence the activity of these output neurons.

Using a technique called optogenetics, they modified neurons in the cholinergic system in the brains of mice so that they could be activated with a flash of blue light, triggering a sudden release of acetylcholine.

This allowed the researchers to closely monitor the interaction between the cholinergic system and the output neurons.

They discovered that if the output neurons were not currently active, not much happened.

But when those neurons received excitatory input to their dendrites, the cholinergic system was able to massively increase their activity.

“It’s as if the cholinergic system has given a ‘go’ signal,” says Fletcher, enabling the output neurons of the neocortex to powerfully respond.

Importantly, this change was selective, and only apparent when excitatory input was being processed in the dendrites of the ‘output’ neurons.

“We have known for some time that the dendrites of the output neurons of the neocortex only become active when animals are actively performing a behaviour, and that this activity is correlated with perception and task performance,” says Williams.

This new work demonstrates that the cholinergic system is critical to this transition in mice and rats, allowing the output neurons to perform computations in a state-dependent manner.

“We suggest that this switch also occurs in the human neocortex, allowing us to rapidly switch our state of vigilance and attention,” says Williams.

“Our work therefore provides important insight into how the progressive degeneration of the cholinergic system in disease blunts human cognition.”

The findings “A dendritic substrate for the cholinergic control of neocortical output neurons” are published in the journal Neuron.

Funding: Australian Research Council, National Health and Medical Research Council, and the Hand, Heart, Pocket Foundation.

Contacts and sources:
University of Queensland
Citation: A Dendritic Substrate for the Cholinergic Control of Neocortical Output Neurons.
Stephen R. Williams, Lee N. Fletcher. Neuron, 2018; DOI: 10.1016/j.neuron.2018.11.035

Prehistoric Horses Were Homebodies

 Geochemical analysis of fossils suggests horses in Florida did not make epic migrations.

Some zebras today trek hundreds of miles to find food and water, but prehistoric horses in parts of North America did not have to undertake epic migrations, according to a new study by the University of Cincinnati.

The findings suggest Florida was something of a horse paradise 5 million years ago, providing everything horses could want in a relatively small area.

UC researchers studied descendants of Eohippus depicted in this 1913 drawing by illustrator Robert Bruce Horsfall. 
File:Eohippus Horsfall.jpg
Graphic/Wikimedia Commons

The study was published in the journal Palaeogeography, Palaeoclimatology, Palaeoecology. It demonstrates UC's commitment to research as part of its strategic direction, Next Lives Here.

UC researchers found that prehistoric horses in Florida were sedentary, much like wild horses today in Assateague Island National Seashore.

 Photo/Michael Miller

Plains zebras and Mongolian wild horses take on epic migrations each year to find water or green grass.

The Mongolian wild horse, also known as a Przewalski’s horse, travels as much as 13 miles per day. And Burchell’s zebras in southern Africa are known for their seasonal migrations that take them as far as 300 miles and back as they follow the rains to green grass.

UC researchers examined 89 fossilized teeth found at excavation sites called Thomas Farm and the Love Bone Bed in Florida. The maps show how Florida's coastline has changed over the eons.

Graphic/Jenelle Wallace

But geologists in UC’s McMicken College of Arts and Sciences found that prehistoric horses in coastal Florida lived and died within a comparatively small area.

“It seems that these horses in Florida were relatively sedentary. They didn’t travel far distances,” said Jenelle Wallace, a UC graduate and lead author of the study.

My third spoken word after mom and dad was horse. I've loved them ever since I was little.

Jenelle Wallace,UC graduate

The study was the basis of Wallace’s master’s thesis. Today, she works as an engineering geologist for the New York State Department of Environmental Conservation.

“My third spoken word after mom and dad was horse,” Wallace said. “I’ve loved them ever since I was little.”

UC graduate Jenelle Wallace prepares a sample in UC professor Brooke Crowley's geology lab.


The world’s first horses originated in North America, lived there for 55 million years before spreading to Asia and Africa while going extinct on their home continent about 12,000 years ago. The small three-toed animals lived like antelope, browsing leaves in deep forests. But during the Miocene Period between 23 million and 8 million years ago, horse evolution exploded into 15 different families. Horses developed bigger bodies, longer legs and hard hooves in place of toes to help them cover more ground.

Their teeth also changed, becoming bigger and longer for cropping coarse grass covered in abrasive silica dust instead of plucking soft leaves. It’s these teeth that helped UC researchers study how extinct horses lived.

UC’s geologists compared strontium isotopes found in fossilized horse teeth to the strontium in bedrock in different parts of the American Southeast to track the horses’ wanderings. Plants such as grass absorb strontium from the earth and the horses, in turn, absorb that strontium while grazing. In this way, strontium serves as a geographic marker.

Illustrator Jay H. Matternes captured a scene from the Miocene Period as an ancient species of horse called Parahippus, lower right, interacts with other carnivores and herbivores of the time.

Illustration/Jay H. Matternes/U.S. Department of the Interior/Wikimedia Commons

UC geology professors and study co-authors Brooke Crowley and Joshua Miller have used this technique to track the movements of other animals, both living and prehistoric. Crowley used bones collected from the nests of secretive goshawks to map the birds’ travels in Madagascar. She and Miller also are studying the movement of Ice Age mastodons in North America.

“There is a lot of opportunity for expanding the use of strontium to look at a variety of animal groups, time periods and locations,” Crowley said.

The study examined seven species of horse along with two known leaf-eaters: a prehistoric tapir and a distant relative of elephants called a gomphothere.

The results were surprising, researchers said.

Of all the animals studied, the tapir seemed to have the widest geographic range based on the high variability of strontium found in its teeth. But given that modern tapirs have relatively modest home ranges, researchers said it’s more likely that prehistoric tapirs consumed river plants that absorbed nutrients carried far downstream.

UC researchers examined strontium in 89 fossilized teeth excavated from two sites in Florida. Pictured is a tooth from the prehistoric horse species Cormohipparion.

 Photo/Jenelle Wallace

Among the horses, the researchers found little variation in the size of their ranges. But the strontium showed a connection between horses and the sea. Like modern horses today in places such as Assateague Island National Seashore, prehistoric horses might have fed along the coast. Researchers suggested the vegetation horses consumed was influenced by marine-derived strontium from seaspray, precipitation or saltwater intrusion into groundwater.

The study was funded by grants from the UC Geology Department, Sigma Xi, the Geological Society of America and the American Society of Mammalogists along with the Association for Women Geoscientists' Winifred Goldring Award.

“The study suggests we’re not the only couch potatoes. If animals don’t have to move, they won’t,” Miller said.

Migrating is dangerous business, Miller said. Animals face injury, illness and starvation when they travel great distances. And in the Miocene Period, horses had to outwit plenty of big predators such as saber-toothed cats.

“The energetic costs of moving are high,” Miller said.

Modern horses evolved longer teeth to crop grass covered in silica and other abrasive grit.

Photo/Michael Miller

Crowley, who also teaches in UC’s Department of Anthropology, said studies like this shed light on the habitat needs of animals long before they were influenced by human activities.

“Having a deep perspective is really important for understanding a species’ needs in conservation and management,” Crowley said. “If we just look at a narrow window of time — like 50 or 100 years — we don’t get a good picture of a species when it’s not in crisis.”

Using the geologic record, researchers can piece together how animals interacted, what allowed them to thrive and what ultimately caused them to perish, she said.

“By using this technique, we can answer questions in a way we couldn’t otherwise,” Crowley said. “That’s the cool thing about geochemistry. You can unlock secrets in teeth and bones.”

UC professor Brooke Crowley uses geochemistry to study prehistoric and living animals. Here she has a mammoth mandible.

Photo/Dottie Stover/UC Creative Services

Contacts and sources:
Michael Miller
University of Cincinnati

Newborn Insects Trapped in Amber Show First Fossil Evidence of How to Crack an Egg

Fossilised newborns, egg shells, and egg bursters preserved together in amber provide the first direct evidence of how insects hatched in deep time, according to a new article published today in the journal Palaeontology.

One of the earliest and toughest trials that all organisms face is birth. The new findings give scientists evidence on how tiny insects broke the barrier separating them from life and took their first steps into an ancient forest.

Trapped together inside 130 million-year-old Lebanese amber, or fossilised resin, researchers found several green lacewing newborn larvae, the split egg shells from where they hatched, and the minute structures the hatchlings used to crack the egg, known as egg bursters. The discovery is remarkable because no definitive evidence of these specialised structures had been reported from the fossil record of egg-laying animals, until now.

The fossil newborns have been described as the new species Tragichrysa ovoruptora, meaning ‘egg breaking’ and ‘tragic green lacewing’, after the fact that multiple specimens were ensnared and entombed in the resin simultaneously.

Newborn insects trapped in amber.

Image credit: Ricardo Pérez-de la Fuente

“Egg-laying animals such as many arthropods and vertebrates use egg bursters to break the egg surface during hatching; a famous example is the ‘egg tooth’ on the beak of newborn chicks,” explains Dr Ricardo Pérez-de la Fuente, a researcher at Oxford University Museum of Natural History and lead author of the work. “Egg bursters are diverse in shape and location. Modern green lacewing hatchlings split the egg with a ‘mask’ bearing a jagged blade. Once used, this ‘mask’ is shed and left attached to the empty egg shell, which is exactly what we found in the amber together with the newborns.”

Green lacewing larvae are small hunters which often carry debris as camouflage, and use sickle-shaped jaws to pierce and suck the fluids of their prey. Although the larvae trapped in amber differ significantly from modern-day relatives, in that they possess long tubes instead of clubs or bumps for holding debris, the studied egg shells and egg bursters are remarkably similar to those of today’s green lacewings. Altogether, they provide the full picture of how these fossil insects hatched like their extant counterparts, about 130 million years ago during the Early Cretaceous.

“The process of hatching is ephemeral and the structures that make it possible tend to disappear quickly once egg-laying animals hatch, so obtaining fossil evidence of them is truly exceptional,” remarks Dr Michael S. Engel, a co-author of the study from the University of Kansas.

Reconstruction of the insects.

Credit: University of Oxford

The Tragichrysa ovoruptora larvae were almost certainly trapped by resin while clutching the eggs from which they had freshly emerged. Such behaviour is common among modern relatives while their body hardens and their predatory jaws become functional. The two mouthparts forming the jaws are not interlocked in most of the fossil larvae, which further suggests that they were recently born.

All the preparations studied were obtained from the same amber piece and are as thin as a pinhead, allowing a detailed account of the fossils and finding the tiny egg bursters, according to Dr Dany Azar, another co-author of the work, from the Lebanese University, who discovered and prepared the studied amber samples.

It would seem reasonable to assume that traits controlling a life event as crucial as hatching would have remained quite stable during evolution. However, as Dr Enrique Peñalver of the Spanish Geological Survey (IGME; Geomining Museum) and co-author of the work explains: “There are known instances in modern insects where closely related groups, even down to the species level, show different means of hatching that can entail the loss of egg bursters.

“So, the long-term stability of a hatching mechanism in a given animal lineage cannot be taken for granted.”

Nonetheless, this new discovery in fossil green lacewings shows the existence 130 million years ago of a sophisticated hatching mechanism which endures to this day.

Contacts and sources:
University of Oxford

Citation: The hatching mechanism of 130-million-year-old insects: an association of neonates, egg shells and egg bursters in Lebanese amber.
Ricardo Pérez-de la Fuente, Michael S. Engel, Dany Azar, Enrique Peñalver. Palaeontology, 2018; DOI: 10.1111/pala.12414

Small Changes in Oxygen Levels Have Big Implications for Ocean Life

Oceanographers at the University of Rhode Island have found that even slight levels of ocean oxygen loss, or deoxygenation, have big consequences for tiny marine organisms called zooplankton.

Zooplankton are important components of the food web in the expanse of deep, open ocean called the midwater. Within this slice of ocean below the surface and above the seafloor are oxygen minimum zones (OMZs), large regions of very low oxygen. Unlike coastal “dead zones” where oxygen levels can suddenly plummet and kill marine life not acclimated to the conditions, zooplankton in OMZs are specially adapted to live where other organisms – especially predators – cannot. But OMZs are expanding due to climate change, and even slight changes to the low oxygen levels can push zooplankton beyond their extraordinary physiological limits.

Lucicutia hulsemannae, a copepod that stays at the Lower Oxycline of the Oxygen Minimum Zone (OMZ). The organism is remarkably tolerant of extremely low oxygen levels, but very sensitive to small changes in those levels.
Lucicutia hulsemannae
Photo by Dawn Outram

“Although the animals in the ocean’s oxygen minimum zone have adapted over millions of years to the very low oxygen of this extreme and widespread midwater habitat, they are living at the very limits of their physiological capability,” said Karen Wishner, a professor of oceanography at URI’s Graduate School of Oceanography and lead author of a new paper on deoxygenation and zooplankton in the Eastern Tropical North Pacific OMZ. “Our research shows that they are sensitive to very small changes in oxygen, and decrease in abundance when oxygen gets just a little bit lower.”

The research team, which this week published their findings in Science Advances, found more natural variability in oxygen levels in the OMZ than previously known. This has a direct effect on the distribution of many types of zooplankton because, as the team discovered, the organisms respond to a less than 1 percent reduction in oxygen levels.

While zooplankton have had millions of years to adapt to conditions in the OMZ, these low oxygen zones may expand rapidly due to climate change, leading to major unanticipated changes to midwater ecosystems. For example, an expansion of the OMZ into shallower waters may make zooplankton more susceptible to predators like fish. If this leads to a zooplankton population crash, it will have impacts all the way up the food chain.

“Further loss of oxygen in ocean waters is predicted in the future as a result of global warming, and these animals may be unable to adapt and persist,” Wishner said. “They are important components of the food web of oceanic ecosystems, and their loss could potentially impact top predators, including whales and commercially important fisheries.”

Wishner and her colleagues, including GSO professor Chris Roman and GSO marine research specialist Dawn Outram, collected their data off the Pacific coast of Mexico in January and February 2017. Brad Seibel, formerly a professor in the College of the Environment and Life Sciences when the project began and now with the University of South Florida College of Marine Science, was the Chief Scientist of the cruise. Overnight, Roman’s “wire flyer,” an ocean instrument designed to take oxygen and other measurements as it quickly oscillates up and down in the water column, was towed from the research vessel Sikuliaq for 50 kilometers. During the day, the vessel followed the same path and collected samples of numerous different types of zooplankton using a high-tech sampling net called a MOCNESS.

The study was funded primarily by the National Science Foundation’s Division of Ocean Sciences. One URI undergraduate (Danielle Moore) and a Summer Undergraduate Research Fellowship in Oceanography (SURFO, URI’s NSF-funded Research Experience for Undergraduates program) student (Shannon Riley from Oregon State University) participated in the research.

Contacts and sources:
Peter J. Hanlon
University of Rhode Island

Citation: Ocean deoxygenation and zooplankton: Very small oxygen differences matter.
K. F. Wishner, B. A. Seibel, C. Roman, C. Deutsch, D. Outram, C. T. Shaw, M. A. Birk, K. A. S. Mislan, T. J. Adams, D. Moore, S. Riley. Science Advances, 2018; 4 (12): eaau5180 DOI: 10.1126/sciadv.aau5180

Bees Can Count with Just Four Nerve Cells in Their Brains

Bees can solve seemingly clever counting tasks with very small numbers of nerve cells in their brains, according to researchers at Queen Mary University of London.

In order to understand how bees count, the researchers simulated a very simple miniature ‘brain’ on a computer with just four nerve cells – far fewer than a real bee has.

The ‘brain’ could easily count small quantities of items when inspecting one item closely and then inspecting the next item closely and so on, which is the same way bees count. This differs from humans who glance at all the items and count them together.

A bumblebee choosing between two patterns containing different numbers of yellow circles.

 Credit Lars Chittka

In this study, published in the journal iScience, the researchers propose that this clever behaviour makes the complex task of counting much easier, allowing bees to display impressive cognitive abilities with minimal brainpower.
One, two, bee

Previous studies have shown bees can count up to four or five items, can choose the smaller or the larger number from a group and even choose 'zero' against other numbers when trained to choose 'less'.

They might have achieved this not by understanding numerical concepts, but by using specific flight movements to closely inspect items which then shape their visual input and simplifies the task to the point where it requires minimal brainpower.

This finding demonstrates that the intelligence of bees, and potentially other animals, can be mediated by very small nerve cells numbers, as long as these are wired together in the right way.

The study could also have implications for artificial intelligence because efficient autonomous robots will need to rely on robust, computationally inexpensive algorithms, and could benefit from employing insect-inspired scanning behaviours.

Lead author Dr Vera Vasas, from Queen Mary University of London, said: “Our model shows that even though counting is generally thought to require high intelligence and large brains, it can be easily done with the smallest of nerve cell circuits connected in the right manner. We suggest that using specific flight movements to scan targets, rather than numerical concepts, explains the bees’ ability to count. This scanning streamlines the visual input and means a task like counting requires little brainpower.

“Careful examination of the actual inspection strategies used by animals might reveal that they often employ active scanning behaviours as shortcuts to simplify complex visual pattern discrimination tasks. Hopefully, our work will inspire others to look more closely not just at what cognitive tasks animals can solve, but also at how they are solving them.”
Size matters

Brain size matters a lot when it comes to bees. They have only one million nerve cells in total, so they have precious little brainpower, and must implement very efficient computational algorithms to solve tasks. In comparison, humans have 86 billion nerve cells which are responsible for receiving information and sending commands.

To model the input to the brain, the authors analysed the point of view of a bee as it flies close to the countable objects and inspects them one-by-one.

The results showed the simulated brain was able to make reliable estimates on the number of items on display when provided with the actual visual input that the bee is receiving while carrying out the task.

Professor Lars Chittka, also from Queen Mary University of London and leader of the team in which the study was performed, added: “These findings add to the growing body of work showing that seemingly intelligent behaviour does not require large brains, but can be underpinned with small neural circuits that can easily be accommodated into the microcomputer that is the insect brain."

Contacts and sources:
Queen Mary University of London
Citation: Insect-inspired sequential inspection strategy enables an artificial network of four neurons to estimate numerosity
Vera Vasas, Lars Chittka. iScience, 2018; DOI: 10.1016/j.isci.2018.12.009

Giant Dinosaurs Regulated Body Temperatures with an "Air Conditioner" in Their Heads

Ankylosaurs likely regulated their body temperature with convoluted nasal passages that acted as heat exchangers between air and body, according to a study published December 19, 2018 in the open-access journal PLOS ONE by Jason Bourke from Ohio University, USA, and colleagues.

This is a Panoplosaurus mirus and Euoplocephalus tutus.

Credit: Bourke et al, 2018.
Modern mammals and birds have long, convoluted nasal passages called turbinates that function as an air conditioner, warming and humidifying air as it is inhaled, and cooling and drying exhaled air to prevent water and heat loss. Although these structures are typically not preserved in the fossil record, convoluted nasal passages resembling turbinates have been discovered in fossils of ankylosaur, an armor-plated herbivorous dinosaur from the Cretaceous. Based on anatomical evidence, Bourke and colleagues had previously suggested that the ankylosaur's nasal passage was an efficient heat exchanger. In this study, the team used computer simulations to test this hypothesis in two ankylosaur species: Panoplosaurus mirus and Euoplocephalus tutus.

Computational fluid dynamic (CFD) analyses were conducted on 3D digital reconstructions of the fossilized nasal passages to simulate airflow and transfer of heat between air and body. Heat recovery in Panoplosaurus and Euoplocephalus during exhalation simulations resulted in energy savings of about 65% and 84%, respectively, which is comparable to values measured experimentally in modern animals. The nasal passages of Euoplocephalus may have been more efficient heat exchangers due to the animal's larger body size.

The authors conclude that elaborate nasal passages likely allowed ankylosaurs to regulate their body temperature by acting as heat exchangers between air and body, similarly to respiratory turbinates in modern mammals and birds.

Bourke adds: "The large body sizes of dinosaurs like ankylosaurs, would have worked great for retaining heat, but they would also have put the small brains of these dinosaurs at a constant risk of overheating. Ankylosaurs appear to have solved this problem by greatly stretching out and coiling their nasal passages within their skull, allowing them to cool down blood destined for the brain and providing an effective air conditioner for their heads."

Contacts and sources:
Jason Bourke

Citation: Convoluted nasal passages function as efficient heat exchangers in ankylosaurs (Dinosauria: Ornithischia: Thyreophora) Jason M. Bourke , Wm. Ruger Porter, Lawrence M. Witmer Published: December 19, 2018