Chaos theory provides hints for controlling the weather

Date: March 28, 2022

Source: RIKEN

Under a project led by the RIKEN Center for Computational Science, researchers have used computer simulations to show that weather phenomena such as sudden downpours could potentially be modified by making small adjustments to certain variables in the weather system. They did this by taking advantage of a system known as a "butterfly attractor" in chaos theory, where a system can have one of two states -- like the wings of a butterfly -- and that it switches back and forth between the two states depending on small changes in certain conditions.

While weather predictions have reached levels of high accuracy thanks to methods such as supercomputer-based simulations and data assimilation, where observational data is incorporated into simulations, scientists have long hoped to be able to control the weather. Research in this area has intensified due to climate change, which has led to more extreme weather events such as torrential rain and storms.

There are methods at present for weather modification, but they have had limited success. Seeding the atmosphere to induce rain has been demonstrated, but it is only possible when the atmosphere is already in a state where it might rain. Geoengineering projects have been envisioned, but have not been carried out due to concerns about what unpredicted long-term effects they might have.

As a promising approach, researchers from the RIKEN team have looked to chaos theory to create realistic possibilities for mitigating weather events such as torrential rain. Specifically, they have focused on a phenomenon known as a butterfly attractor, proposed by mathematician and meteorologist Edward Lorentz, one of the founders of modern chaos theory. Essentially, this refers to a system that can adopt one of two orbits that look like the wings of a butterfly, but can change the orbits randomly based on small fluctuations in the system.

To perform the work, the RIKEN team ran one weather simulation, to serve as the control of "nature" itself, and then ran other simulations, using small variations in a number of variables describing the convection -- how heat moves through the system -- and discovered that small changes in several of the variables together could lead to the system being in a certain state once a certain amount of time elapsed.

According to Takemasa Miyoshi of the RIKEN Center for Computational Science, who led the team, "This opens the path to research into the controllability of weather and could lead to weather control technology. If realized, this research could help us prevent and mitigate extreme windstorms, such as torrential rains and typhoons, whose risks are increasing with climate change."

"We have built a new theory and methodology for studying the controllability of weather," he continues. "Based on the observing system simulation experiments used in previous predictability studies, we were able to design an experiment to investigate predictability based on the assumption that the true values (nature) cannot be changed, but rather that we can change the idea of what can be changed (the object to be controlled)."

Looking to the future, he says, "In this case we used an ideal low-dimensional model to develop a new theory, and in the future we plan to use actual weather models to study the possible controllability of weather."

The work, published in Nonlinear Processes of Geophysics, was done as part of the Moonshot R&D Millennia program, contributing to the new Moonshot goal #8.


Journal Reference:
Takemasa Miyoshi, Qiwen Sun. Control simulation experiment with Lorenz's butterfly attractor. Nonlinear Processes in Geophysics, 2022; 29 (1): 133 DOI: 10.5194/npg-29-133-2022

'An underutilized tool:' UV-LED lights can kill coronaviruses and HIV with the flip of a switch, study finds

Date: March 29, 2022

University of Toronto

The same light bulbs used in offices and public spaces can destroy coronaviruses and HIV, according to a new study from U of T Scarborough.

Researchers killed both viruses using UV-LED lights, which can alternate between white light and decontaminating ultraviolet (UV) light. With a cheap retrofit, they could also be used in many standard lighting fixtures, giving them a "unique appeal" for public spaces, says Christina Guzzo, senior author of the study.

"We're at a critical time where we need to use every single possible stop to get us out of this pandemic," says Guzzo, an assistant professor in the department of biological sciences. "Every mitigation strategy that can be easily implemented should be used."

UV lights kill viruses through radiation. Guzzo, alongside PhD students Arvin T. Persaud and Jonathan Burnie, first tested the lights on bacterial spores notorious for their resistance to this radiation (known as Bacillus pumilus spores).

"If you're able to kill these spores, then you can reasonably say you should be able to kill most other viruses that you would commonly encounter in the environment," says Guzzo, principal investigator at the Guzzo Lab.

Within 20 seconds of UV exposure, the spores' growth dropped by 99 per cent.

The researchers then created droplets containing coronaviruses or HIV, to mimic typical ways people encounter viruses in public, such as from coughing, sneezing and bleeding. The droplets were then exposed to UV light and placed in a culture to see if any of the virus remained active. With just 30 seconds of exposure, the virus' ability to infect dropped by 93 per cent.

Upon testing the viruses at different concentrations, they found samples with more viral particles were more resistant to the UV lights. But even with a viral load so high Guzzo calls it "the worst-case scenario," infectivity dropped 88 per cent.

Though it wasn't included in the study, Guzzo and her students also compared UV light to two heavy duty disinfectants used in lab research. They found the lights were similarly effective in their ability to deactivate viruses.

"I was really surprised that UV could perform on the same level of those commonly used lab chemicals, which we regard as the gold standard," she says. "That made me think, 'Oh, my gosh, this is a legitimate tool that's really underutilized.'"

Balance UV's pros and cons with clever use, researchers say

While the lights still left a small percentage of the virus viable, Guzzo references the "Swiss cheese model" of defence against COVID. Every strategy to fight the spread has its holes, but every layer is another chance to stop straggling virus particles.

Repeated exposure to UV light is key to catching those missed particles -- fortunately, it's as easy as flipping a switch. It's also simpler to change a light bulb than an air filtration system. Guzzo notes that UV-LEDs are cheap and could be easy to retrofit in existing light fixtures, and that the bulbs are long-lasting and simple to maintain.

"You could disinfect in a way that wouldn't be infringing on people's enjoyment of that everyday 'normal' life that they long for," Guzzo says.

The lights also benefit from automation. A standardized, germicidal dose of light can be delivered each time, while the process of wiping down spaces with disinfectants leaves room for human error. Chemicals and waste from these disinfectants also end up in watersheds and landfills as hands are washed and wipes thrown away.

But the lights aren't harmless, and there's a reason for wearing sunscreen and sunglasses -- UV radiation damages nucleic acid, and repeated, prolonged exposure is harmful. That's why Guzzo says the lights should be used when public spaces are empty, such as vacated buses that have finished their routes, or empty elevators travelling between floors. Escalator handrails could be continuously disinfected by putting UV lights in the underground part of the track, cleaning it with each rotation.

Safe Antivirus Technologies, Inc., a Toronto-based start-up company that partnered with Guzzo for the study, is developing unique UV-LED lighting modules. With motion sensors, the lights automatically switch to UV light when a room is empty, then turn back to regular light with movement.

Funded by the Natural Sciences and Engineering Research Council (NSERC) Alliance COVID-19 Grant and published in the Virology Journal, this study highlights UV-LEDs as a tool that could be used beyond the pandemic, ideally to help prevent another.

"Worldwide events like the COVID-19 pandemic, as terrible as they are, hopefully can still be learned from," Guzzo says. "One thing we learned is that this is an underutilized tool we should think more about implementing."

Journal Reference:
Arvin T. Persaud, Jonathan Burnie, Laxshaginee Thaya, Liann DSouza, Steven Martin, Christina Guzzo. A UV-LED module that is highly effective at inactivating human coronaviruses and HIV-1. Virology Journal, 2022; 19 (1) DOI: 10.1186/s12985-022-01754-w

New model predicts how geographic features influence evolutionary outcomes

Date: March 21, 2022

Source: Washington University in St. Louis

Biologists have developed a new method to measure the extent to which regional geographic features -- including barriers between regions, like mountains or water -- affect local rates of speciation, extinction and dispersal for species. As a test case, they successfully used their model to delineate the movement and diversification of neotropical anole lizards.

"Geographical features influence evolutionary outcomes in predictable ways," said Michael Landis, assistant professor of biology in Arts & Sciences at Washington University in St. Louis, first author of the study published in the Proceedings of the National Academy of Sciences (PNAS). "Our study lays the statistical groundwork to model how different geographical features might act as barriers to species movement or might accelerate extinction for other groups besides anoles.

"Such inferences can also help us predict which species are most likely to move, evolve or go extinct as climate change intensifies," he said.

Scientists have long recognized that geography plays a role in how species colonize new regions and whether widespread species eventually separate out into groups that become genetically distinct, losing the ability to reproduce with each other.

But even though geography plays a clear, describable role in the fate of many individual animal and plant species, no one has previously developed standardized models that allow geographical features to shape how evolutionary radiations unfold in space. To address this gap, Landis and his collaborators designed a new phylogenetic model of biogeography that they named FIG.

"FIG allows speciation, extinction and dispersal rates to depend on the local regional features that each species encounters in its range as it evolves," Landis said. "For example, the presence of a barrier interrupting a species range may cause that species to 'split' into two different species faster than if no barrier existed.

To demonstrate its capabilities, Landis and his collaborators used their approach to model the biogeography of Anolis lizards, a group of lizards known to have spread throughout the Caribbean islands and North and South America.

The qualitative part of what they learned was not surprising: that anoles tend to move over short distances rather than far distances, and that movements over water were less common than movements over land for equivalent distances.

"In other words, far places are far and water is wet -- which told us that our new model was in the right ballpark," Landis quipped. But with persistence, he soon proved that the model can quantify relationships between certain geographical features and evolutionary rates that were previously difficult to measure.

"For example, we were able to measure a maximum distance at which species ranges become too widespread to resist splitting in two," Landis said. "To our surprise and satisfaction, our estimated distances aligned nicely with where widespread anoles are found today: some continental anoles are widespread among adjacent regions, but water restricts the ranges of most insular anoles to just one region."

The scientists discovered that distance impedes the movement of Anolis lizards, both in terms of range expansion through dispersal and in terms of allowing widespread species with fragmented ranges to 'split' into two species.

Distances over water have a much greater effect on limiting movement than distances over land, Landis said. The model revealed that distances over water have three times the effect of equivalent distances over land.

Landis and his collaborators -- including Ignacio Quintero at the École Normale Supérieure in Paris, Michael Donoghue and Martha Muñoz at Yale University and Felipe Zapata at University of California, Los Angeles -- have made their new model freely available to others. They anticipate that other biologists will customize and apply FIG to test new hypotheses concerning how other groups of animal and plant species were shaped by the mountains and oceans that they encountered.

"Biogeographers recognize that greater distances and geographical barriers both limit movement," Landis said. "But it is harder to get biogeographers to agree on the extent to which distances or barriers should influence how species spread over millions of years.

"We biologists haven't had the right statistical tools to model how geographical features might influence speciation, extinction and dispersal rates among closely related evolutionary lineages, so we invented some," he said. "The key ideas that emerged in this study arose from a close collaboration among organismal and mathematical biologists who are fascinated by how species evolve in space."


Journal Reference:
Michael J. Landis, Ignacio Quintero, Martha M. Muñoz, Felipe Zapata, Michael J. Donoghue. Phylogenetic inference of where species spread or split across barriers. Proceedings of the National Academy of Sciences, 2022; 119 (13) DOI: 10.1073/pnas.2116948119

Unravelling the mystery of parrot longevity

Bigger brains have led some species of parrot to live surprisingly long lives, new research shows

Date: March 29, 2022 

Source: Max-Planck-Gesellschaft

Parrots are famous for their remarkable cognitive abilities and exceptionally long lifespans. Now, a study led by Max Planck researchers has shown that one of these traits has likely been caused by the other. By examining 217 parrot species, the researchers revealed that species such as the scarlet macaw and sulphur-crested cockatoo have extremely long average lifespans, of up to 30 years, which are usually seen only in large birds. Further, they demonstrated a possible cause for these long lifespans: large relative brain size. The study is the first to show a link between brain size and lifespan in parrots, suggesting that increased cognitive ability may have helped parrots to navigate threats in their environment and to enjoy longer lives.

Despite the fact that parrots are well known for their long lives and complex cognition, with lifespans and relative brain size on par with primates, it remains unknown whether the two traits have influenced each other.

"The problem has been sourcing good quality data," says Simeon Smeele, a doctoral student at the Max Planck Institute of Animal Behavior (MPI-AB) and lead author on the study, published in Proceedings of the Royal Society B. Understanding what has driven parrot longevity is only possible by comparing living parrots. "Comparative life-history studies require large sample sizes to provide certainty, because many processes are a play at once and this creates a lot of variation," says Smeele.

To generate an adequate sample size, scientists from the MPI-AB and the Max Planck Institute for Evolutionary Anthropology (MPI-EvA) teamed up with Species360, which draws on animal records from zoos and aquaria. Together, they compiled data from over 130,000 individual parrots sourced from over 1000 zoos. This database allowed the team to gain the first reliable estimates of average life span of 217 parrot species -- representing over half of all known species.

The analysis revealed an astonishing diversity in life expectancy, ranging from an average of two years for the fig parrot up to an average of 30 years for the scarlet macaw. Other long-lived species include the sulphur crested cockatoo from Australia, which lives on average 25 years.

"Living an average of 30 years is extremely rare in birds of this size," says Smeele who worked closely with Lucy Aplin from MPI-AB and Mary Brooke McElreath from MPI-EvA on the study. "Some individuals have a maximum lifespan of over 80 years, which is a respectable age even for humans. These values are really spectacular if you consider that a human male weights about 100 times more."

Next, the team employed a large-scale comparative analysis to determine whether or not parrots' renowned cognitive abilities had any influence on their longevity. They examined two hypotheses: First, that having relatively larger brains enable longer lifespans. In other words, smarter birds can better solve problems in the wild, thus enjoying longer lives. Second, that relatively larger brains take longer to grow, and therefore require longer lifespans. For each species, they collected data on relative brain size, as well as average body weight and developmental variables.

They then combined the data and ran models for each hypothesis, looking at which model best explained the data. Their results provide the first support that increased brain size has enabled longer lifespans in parrots. Because brain size relative to body size can be an indicator for intelligence, the findings suggest that the parrots with relatively large brains had cognitive capabilities that allowed them to solve problems in the wild that could otherwise kill them, and this intelligence enabled them to live longer lives.

"This supports the idea that in general larger brains make species more flexible and allow them to live longer," says Smeele. "For example, if they run out of their favourite food, they could learn to find something new and thus survive."

The scientists are surprised that factors such as diet, or the greater developmental time required to develop larger brains, did not lead to longer average lifespans. "We would have expected the developmental path to play a more important role because in primates it is this developmental cost that explains the link between brain size and longevity," says Smeele.

In the future, the team plan to explore if sociality and cultural learning in parrots might have also contributed to long lifespans. Says Smeele: "Large-brained birds might spend more time socially learning foraging techniques that have been around for multiple generations. This increased learning period could potentially also explain the longer life spans, as it takes more time but also makes the foraging repertoire more adaptive."

"One thing that makes us humans special is the vast body of socially learned skills. We are really excited to see if long-lived parrots also have a 'childhood' in which they have to learn everything from finding and opening nuts to avoid upsetting the dominant male. Ultimately, we would like to understand which evolutionary drivers create a species with a life-history very similar to our ancestors."


Related Multimedia:
Scarlet macaw

Journal Reference:
Simeon Q. Smeele, Dalia A. Conde, Annette Baudisch, Simon Bruslund, Andrew Iwaniuk, Johanna Staerk, Timothy F. Wright, Anna M. Young, Mary Brooke McElreath, Lucy Aplin. Coevolution of relative brain size and life expectancy in parrots. Proceedings of the Royal Society B: Biological Sciences, 2022; 289 (1971) DOI: 10.1098/rspb.2021.2397

How scientists found an African bat lost to science for 40 years

Now the first recording of the Hill’s horseshoe bat’s echolocation call may help find more

This critically endangered Hill’s horseshoe bat (Rhinolophus hilli), which was released after scientists measured its features, marks the first recorded observation of the species since 1981.
JON FLANDERS, BAT CONSERVATION INTERNATIONAL

By Anna Gibbs

Julius Nziza still remembers the moment vividly. Just before dawn on a chilly January morning in 2019, he and his team gently extracted a tiny brown bat from a net purposely strung to catch the nocturnal fliers. A moment later, the researchers’ whoops and hollers pierced the heavy mist blanketing Rwanda’s Nyungwe National Park. The team had just laid eyes on a Hill’s horseshoe bat (Rhinolophus hilli), which scientists hadn’t seen for nearly four decades.

Nziza, a wildlife veterinarian at Gorilla Doctors in Musanze, Rwanda, and a self-described “bat champion,” had been looking for the critically endangered R. hilli since 2013. For several years, Nziza and Paul Webala from Maasai Mara University in Narok, Kenya, with the help of Nyungwe park rangers, surveyed the forest for spots where the bats might frequent. They didn’t find R. hilli, but it helped them narrow where to keep looking.

In 2019, the team decided to concentrate on roughly four square kilometers in a high-elevation region of the forest where R. hilli had last been spotted in 1981. Accompanied by an international team of researchers, Nziza and Webala set out for a 10-day expedition in search of the elusive bat. It wasn’t rainy season yet, but the weather was already starting to turn. “It was very, very, very cold,” Nziza recalls.

Every night, from sunset until close to midnight, the researchers stretched nets across trails, where bats are most likely to fly, and kept watch. Then, after a few hours of rest, they woke early to check the traps again. It was cold enough that the bats could die if stuck too long.

At 4 a.m. on the fourth day, the researchers caught a bat with the distinctive horseshoe-shaped nose of all horseshoe bat species. But it looked slightly different from others they had captured. This one had darker fur and a pointed tip on its nose.

Everyone began shouting: “This is it!”

After a moment of celebration at 4 a.m., the research team began studying features of the specimen to see if what they caught was indeed R. hilli.

JON FLANDERS, BAT CONSERVATION INTERNATIONAL

The researchers felt “almost 99 percent sure” they had found the lost bat. “We had a couple beers in the evening,” Nziza says. “It was worth celebration.” To be 100 percent sure, though, the team needed to compare its specimen to past ones of R. hilli. Fortunately, there were two in museums in Europe.

That’s because this isn’t the first time that R. hilli was lost, then found, to science. Victor van Cakenberghe, a retired taxonomist at the University of Antwerp in Belgium, rediscovered R. hilli 17 years after it was first seen in 1964. He says he still remembers finding the bat tangled in a mist net strung across a river. He kept the specimen and brought it back to a Belgian museum.

Nearly 40 years later, Nziza and colleagues compared the measurements of their bat, which was released into the wild, to the preserved bat. At long last, it can be confidently said that R. hilli was rediscovered again, researchers report March 11 in a preprint submitted to Biodiversity Data Journal.

And, for the first time ever, the scientists recorded R. hilli’s echolocation call. Now, the rangers can use acoustic detectors to keep an eye — or rather, an ear — on the bat (SN: 10/23/20). In nine months, they’ve already captured R. hilli calls from eight different locations in the same small area.

Bat song

The last time scientists saw a Hill’s horseshoe bat was in 1981. An international team rediscovered the species in 2019 and, for the first time, recorded its echolocation call to help prevent it from being lost to science once again.

A Hill’s horseshoe bat echolocation call

BAT CONSERVATION INTERNATIONAL

Julius Nziza (far left) and Paul Webala (second from left) work with the research team to capture the first-ever audio recording of Hill’s horseshoe bat’s echolocation call.

WINIFRED FRICK, BAT CONSERVATION INTERNATIONAL

The team published its data to the open-access Global Biodiversity Information Facility in hopes of speeding up conservation efforts for the bat. Africa is home to over 20 percent of the world’s bats, but with a longstanding research focus on bats in Europe and the Americas, little is known about African bat species.

“It’s a whole new thing,” Nziza says. “That’s why everybody’s excited.”

sciencenews.org

CITATIONS

J. Flanders et al. Rediscovery of the critically endangered Hill's horseshoe bat (Rhinolophus hilli) and other new records of bat species in Rwanda. ARPHA Preprints. Posted March 11, 2022. doi: 10.3897/arphapreprints.e83547.


About Anna Gibbs
E-mail
Twitter
Anna Gibbs is the spring 2022 science writing intern at Science News. She holds a B.A. in English from Harvard College.

Invasive jorō spiders get huge and flashy — if they’re female

Males are the other half of the story, so tiny and drab they’re often missed in oversized webs


Out in the open, female jorō spiders look eye-smacking obvious, but they’re sneaky hitchhikers. They can hide in wheel wells and under car hoods, tricks that might facilitate their spread.


By Susan Milius

Some thumbnail-sized, brown male spiders in Georgia could be miffed if they paid the least attention to humans and our news obsessions.

Recent stories have made much of “giant” jorō spiders invading North America from eastern Asia, some large enough to span your palm. Lemon yellow bands cross their backs. Bright red bits can add drama, and a softer cheesecake yellow highlights the many joints on long black legs.

The showy giants, however, are just the females of Trichonephila clavata. Males hardly get mentioned except for what they’re not: colorful or big. A he-spider hulk at 8 millimeters barely reaches half the length of small females. Even the species nickname ignores the guys. The word jorō, borrowed from Japanese, translates to such unmasculine terms as “courtesan,” “lady-in-waiting” and even “entangling or binding bride.”

Mismatched sexes are nothing new for spiders. The group shows the most extreme size differences between the sexes known among land animals, says evolutionary biologist Matjaž Kuntner of the Evolutionary Zoology Lab in Ljubljana, Slovenia. The most dramatic case Kuntner has heard of comes from Arachnura logio scorpion spiders in East Asia, with females 14.8 times the size of the males.

With such extreme size differences, mating conflicts in animals can get violent: females cannibalizing males and so on (SN: 11/13/99). As far as Kuntner knows, however, jorō spiders don’t engage in these “sexually conflicted” extremes. Males being merely half size or thereabouts might explain the relatively peaceful encounters.

When it comes to humans, these spiders don’t bother anybody who doesn’t bother them. But what a spectacle they make. “I’ve got dozens and dozens in my yard,” says ecologist Andy Davis at the University of Georgia in Athens. “One big web can be 3 or 4 feet in diameter.” Jorō spiders have lived in northeastern Georgia since at least 2014.

A female jorō spider looms so much bigger that it’s easy to overlook the males of the species (inset, shown to scale) that often hang out in her big web.

J. HOWELL (FEMALE) AND B.J. FREEMAN (INSET MALE), 

E.R. HOEBEKE, W. HUFFMASTER AND B.J. FREEMAN/PEERJ 2015

These new neighbors inspired Davis and undergraduate Benjamin Frick to see if the newcomers withstand chills better than an earlier invader, Trichonephila clavipes, their more tropical relative also known as the golden silk orb-weaver. (The jorō also can spin yellow-tinged silk.) The earlier arrival’s flashy females and drab males haven’t left the comfy Southeast they invaded at least 160 years ago.

Figuring out the jorō’s hardiness involves taking the spider’s pulse. But how do you do that with an arthropod with a hard exoskeleton? A spider’s heart isn’t a mammallike lump circulating blood through a closed system. The jorō sluices its bloodlike fluid through a long tube open at both ends. “Think of a garden hose,” says Davis. He has measured heart rates of monarch caterpillars, and he found a spot on a spider’s back where a keen-eyed observer can count throbs.

Female jorō spiders packed in ice to simulate chill stress kept their heart rates some 77 percent higher than the stay-put T. clavipes, tests showed. Checking jorō oxygen use showed females have about twice the metabolic rate. And about two minutes of freezing temperatures showed better female survival (74 percent versus 50 percent). Lab tests used only the conveniently big jorō females, though male ability to function in random cold snaps could matter too.

Plus jorō sightings in the Southeast so far suggest the newer arrival needs less time than its relative to make the next generation, an advantage for farther to the north. The adults don’t need to survive deep winter in any case. Mom and dad die off, in November in Georgia, and leave their hundreds of eggs packed in silk to weather the cold and storms.

Reports on the citizen-observer iNaturalist site suggest that in Georgia, jorō spiders already cover some 40,000 square kilometers, Davis and Frick report February 17 in Physiological Entomology. Sightings now stretch into Tennessee and the Carolinas. But how far the big moms and tiny dads will go and when, we’ll just have to wait and see.


CITATIONS

A.K. Davis and B.L. Frick. Physiological evaluation of newly invasive jorō spiders (Trichonephila clavata) in the southeastern USA compared to their naturalized cousin, Trichonephila clavipes. Physiological Entomology. Published online February 17, 2022. doi: 10.1111/phen.12385.I

E.R. Hoebeke et al. Nephila clavata L. Koch, the jorō spider of East Asia, newly recorded from North America (Araneae: Nephilidae). PeerJ. Published online February 5, 2015. doi: 10.7717/peerj.763

M. Kuntner and J.A. Coddington. Sexual size dimorphism: Evolution and perils of extreme phenotypes in spiders. Annual Review of Entomolog. Vol. 65, January 2020, p. 57. doi: 10.1146/annurev-ento-011019-025032.

About Susan Milius
E-mail
Twitter
Susan Milius is the life sciences writer, covering organismal biology and evolution, and has a special passion for plants, fungi and invertebrates. She studied biology and English literature.

Spiders use webs to extend their hearing

Date: March 29, 2022

Source: Binghamton University

Summary:

A newly published study of orb-weaving spiders has yielded some extraordinary results: The spiders are using their webs as extended auditory arrays to capture sounds, possibly giving spiders advanced warning of incoming prey or predators.

Everyone knows that humans and most other vertebrate species hear using eardrums that turn soundwave pressure into signals for our brains. But what about smaller animals like insects and arthropods? Can they detect sounds? And if so, how?

Distinguished Professor Ron Miles, a Department of Mechanical Engineering faculty member at Binghamton University's Thomas J. Watson College of Engineering and Applied Science, has been exploring that question for more than three decades, in a quest to revolutionize microphone technology.

A newly published study of orb-weaving spiders -- the species featured in the classic children's book "Charlotte's Web" -- has yielded some extraordinary results: The spiders are using their webs as extended auditory arrays to capture sounds, possibly giving spiders advanced warning of incoming prey or predators.

The paper, "Outsourced Hearing in an Orb-Weaving Spider that Uses its Web as an Auditory Sensor," published March 29 in the Proceedings of the National Academy of Sciences, provides the first evidence that a spider can outsource hearing to its web.

It is well-known that spiders respond when something vibrates their webs, such as potential prey. In these new experiments, researchers for the first time show that spiders turned, crouched or flattened out in response to sounds in the air.

The study is the latest collaboration between Miles and Ron Hoy, a biology professor from Cornell, and it has implications for designing extremely sensitive bio-inspired microphones for use in hearing aids and cell phones.

Jian Zhou, who earned his PhD in Miles' lab and is doing postdoctoral research at the Argonne National Laboratory, and Junpeng Lai, a current PhD student in Miles' lab, are co-first authors. Miles, Hoy and Associate Professor Carol I. Miles from the Harpur College of Arts and Sciences' Department of Biological Sciences at Binghamton are also authors for this study. Grants from the National Institutes of Health to Ron Miles funded the research.

A single strand of spider silk is so thin and sensitive that it can detect the movement of vibrating air particles that make up a soundwave, which is different from how eardrums work. Ron Miles' previous research has led to the invention of novel microphone designs that are based on hearing in insects.

"The spider is really a natural demonstration that this is a viable way to sense sound using viscous forces in the air on thin fibers," he said. "If it works in nature, maybe we should have a closer look at it."

Spiders can detect miniscule movements and vibrations through sensory organs on their tarsal claws at the tips of their legs, which they use to grasp their webs. Orb-weaver spiders are known to make large webs, creating a kind of acoustic antennae with a sound-sensitive surface area that is up to 10,000 times greater than the spider itself.

In the study, the researchers used Binghamton University's anechoic chamber, a completely soundproof room under the Innovative Technologies Complex. Collecting orb-weavers from windows around campus, they had the spiders spin a web inside a rectangular frame so they could position it where they wanted.

The team began by using pure tone sound 3 meters away at different sound levels to see if the spiders responded or not. Surprisingly, they found spiders can respond to sound levels as low as 68 decibels. For louder sound, they found even more types of behaviors.

They then placed the sound source at a 45-degree angle, to see if the spiders behaved differently. They found that not only are the spiders localizing the sound source, but they can tell the sound incoming direction with 100% accuracy.

To better understand the spider-hearing mechanism, the researchers used laser vibrometry and measured over one thousand locations on a natural spider web, with the spider sitting in the center under the sound field. The result showed that the web moves with sound almost at maximum physical efficiency across an ultra-wide frequency range.

"Of course, the real question is, if the web is moving like that, does the spider hear using it?" Miles said. "That's a hard question to answer."

Lai added: "There could even be a hidden ear within the spider body that we don't know about."

So the team placed a mini-speaker 5 centimeters away from the center of the web where the spider sits, and 2 millimeters away from the web plane -- close but not touching the web. This allows the sound to travel to the spider both through air and through the web. The researchers found that the soundwave from the mini-speaker died out significantly as it traveled through the air, but it propagated readily through the web with little attenuation. The sound level was still at around 68 decibels when it reached the spider. The behavior data showed that four out of 12 spiders responded to this web-borne signal.

Those reactions proved that the spiders could hear through the webs, and Lai was thrilled when that happened: "I've been working on this research for five years. That's a long time, and it's great to see all these efforts will become something that everybody can read."

The researchers also found that, by crouching and stretching, spiders may be changing the tension of the silk strands, thereby tuning them to pick up different frequencies. By using this external structure to hear, the spider could be able to customize it to hear different sorts of sounds.

Future experiments may investigate how spiders make use of the sound they can detect using their web. Additionally, the team would like to test whether other types of web-weaving spiders also use their silk to outsource their hearing.

"It's reasonable to guess that a similar spider on a similar web would respond in a similar way," Ron Miles said. "But we can't draw any conclusions about that, since we tested a certain kind of spider that happens to be pretty common."

Lai admitted he had no idea he would be working with spiders when he came to Binghamton as a mechanical engineering PhD student.

"I've been afraid of spiders all my life, because of their alien looks and hairy legs!" he said with a laugh. "But the more I worked with spiders, the more amazing I found them. I'm really starting to appreciate them."

Video: https://youtu.be/PIrotdSIxG4

Journal Reference:
Jian Zhou, Junpeng Lai, Gil Menda, Jay A. Stafstrom, Carol I. Miles, Ronald R. Hoy, Ronald N. Miles. Outsourced hearing in an orb-weaving spider that uses its web as an auditory sensor. Proceedings of the National Academy of Sciences, 2022; 119 (14) DOI: 10.1073/pnas.2122789119

Wally Broecker divined how the climate could suddenly shift

The shutdown of an ocean conveyor belt could cause abrupt climate change

Wally Broecker, shown here in 1997, proposed that the shutdown of a major ocean circulation pattern could lead to abrupt climate change.

By Alexandra Witze

MARCH 29, 2022 

It was the mid-1980s, at a meeting in Switzerland, when Wally Broecker’s ears perked up. Scientist Hans Oeschger was describing an ice core drilled at a military radar station in southern Greenland. Layer by layer, the 2-kilometer-long core revealed what the climate there was like thousands of years ago. Climate shifts, inferred from the amounts of carbon dioxide and of a form of oxygen in the core, played out surprisingly quickly — within just a few decades. It seemed almost too fast to be true.

Broecker returned home, to Columbia University’s Lamont-Doherty Earth Observatory, and began wondering what could cause such dramatic shifts. Some of Oeschger’s data turned out to be incorrect, but the seed they planted in Broecker’s mind flowered — and ultimately changed the way scientists think about past and future climate.

A geochemist who studied the oceans, Broecker proposed that the shutdown of a major ocean circulation pattern, which he named the great ocean conveyor, could cause the North Atlantic climate to change abruptly. In the past, he argued, melting ice sheets released huge pulses of water into the North Atlantic, turning the water fresher and halting circulation patterns that rely on salty water. The result: a sudden atmospheric cooling that plunged the region, including Greenland, into a big chill. (In the 2004 movie The Day After Tomorrow, an overly dramatized oceanic shutdown coats the Statue of Liberty in ice.)

It was a leap of insight unprecedented for the time, when most researchers had yet to accept that climate could shift abruptly, much less ponder what might cause such shifts.

Broecker not only explained the changes seen in the Greenland ice core, he also went on to found a new field. He prodded, cajoled and brought together other scientists to study the entire climate system and how it could shift on a dime. “He was a really big thinker,” says Dorothy Peteet, a paleoclimatologist at NASA’s Goddard Institute for Space Studies in New York City who worked with Broecker for decades. “It was just his genuine curiosity about how the world worked.”

Broecker was born in 1931 into a fundamentalist family who believed the Earth was 6,000 years old, so he was not an obvious candidate to become a pathbreaking geoscientist. Because of his dyslexia, he relied on conversations and visual aids to soak up information. Throughout his life, he did not use computers, a linchpin of modern science, yet became an expert in radiocarbon dating. And, contrary to the siloing common in the sciences, he worked expansively to understand the oceans, the atmosphere, the land, and thus the entire Earth system.

By the 1970s, scientists knew that humans were pouring excess carbon dioxide into the atmosphere, through burning fossil fuels and cutting down carbon-storing forests, and that those changes were tinkering with Earth’s natural thermostat. Scientists knew that climate had changed in the past; geologic evidence over billions of years revealed hot or dry, cold or wet periods. But many scientists focused on long-term climate changes, paced by shifts in the way Earth rotates on its axis and circles the sun — both of which change the amount of sunlight the planet receives. A highly influential 1976 paper referred to these orbital shifts as the “pacemaker of the ice ages.”

Ice cores from Antarctica and Greenland changed the game. In 1969, Willi Dansgaard of the University of Copenhagen and colleagues reported results from a Greenland ice core covering the last 100,000 years. They found large, rapid fluctuations in oxygen-18 that suggested wild temperature swings. Climate could oscillate quickly, it seemed — but it took another Greenland ice core and more than a decade before Broecker had the idea that the shutdown of the great ocean conveyor system could be to blame.

Pulled from southern Greenland beginning in 1979, the Dye-3 ice core (the drill used to retrieve the core is shown) revealed that abrupt climate change had occurred in the past.

THE NIELS BOHR INSTITUTE

Broecker proposed that such a shutdown was responsible for a known cold snap that started around 12,900 years ago. As the Earth began to emerge from its orbitally influenced ice age, water melted off the northern ice sheets and washed into the North Atlantic. Ocean circulation halted, plunging Europe into a sudden chill, he said. The period, which lasted just over a millennium, is known as the Younger Dryas after an Arctic flower that thrived during the cold snap. It was the last hurrah of the last ice age.

Evidence that an ocean conveyor shutdown could cause dramatic climate shifts soon piled up in Broecker’s favor. For instance, Peteet found evidence of rapid Younger Dryas cooling in bogs near New York City — thus establishing that the cooling was not just a European phenomenon but also extended to the other side of the Atlantic. Changes were real, widespread and fast.

By the late 1980s and early ’90s, there was enough evidence supporting abrupt climate change that two major projects — one European, one American — began to drill a pair of fresh cores into the Greenland ice sheet. Richard Alley, a geoscientist at Penn State, remembers working through the layers and documenting small climatic changes over thousands of years. “Then we hit the end of the Younger Dryas and it was like falling off a cliff,” he says. It was “a huge change after many small changes,” he says.

 “Breathtaking.”

The new Greenland cores cemented scientific recognition of abrupt climate change. Though the shutdown of the ocean conveyor could not explain all abrupt climate changes that had ever occurred, it showed how a single physical mechanism could trigger major planet-wide disruptions. It also opened discussions about how rapidly climate might change in the future.

Broecker, who died in 2019, spent his last decades exploring abrupt shifts that are already happening. He worked, for example, with billionaire Gary Comer, who during a yacht trip in 2001 was shocked by the shrinking of Arctic sea ice, to brainstorm new directions for climate research and climate solutions.

Broecker knew more than almost anyone about what might be coming. He often described Earth’s climate system as an angry beast that humans are poking with sticks. And one of his most famous papers was titled “Climatic change: Are we on the brink of a pronounced global warming?”

It was published in 1975.


About Alexandra Witze
Twitter
Alexandra Witze is a contributing correspondent for Science News. Based in Boulder, Colo., Witze specializes in earth, planetary and astronomical sciences.

Marie Maynard Daly was a trailblazing biochemist, but her full story may be lost

Though her research contributions are clear, her own perspective on her work is missing

Marie Maynard Daly found experimental evidence that protein synthesis requires RNA.
ARCHIVES OF THE ALBERT EINSTEIN COLLEGE OF MEDICINE, TED BURROWS, PHOTOGRAPHER

By Megan Scudellari
MARCH 2, 2022 AT 9:00 AM

Marie Maynard Daly is known as the first African American woman to receive a Ph.D. in chemistry, earned in 1947 from Columbia University. It’s a superlative often repeated in the brief profiles of Daly that appear in anthologies of notable Black and female scientists — and an impressive achievement on its own.

But when I set out to discover more about Daly’s work and life, to bring her story to a wider audience, I found out I was two decades too late.

Daly published from 1949 to 1985, retired in 1986 and died in 2003 at the age of 82. Her husband predeceased her; she had no children. Most of Daly’s collaborators and colleagues have died in the last decade; her mentees are retired and unreachable; her former employers and professional organizations have minimal or no documents chronicling her life or research.

What we know about Daly comes primarily from her record of scientific publications. While working with biochemists Alfred Mirsky and Vincent Allfrey at Rockefeller Institute in New York City in the early 1950s, Daly found direct experimental evidence that protein synthesis requires RNA. James Watson cited that work in the lecture he gave after receiving the Nobel Prize for the discovery of the double-helix structure of DNA. Daly also identified a new type of histones and determined the distribution of different nitrogenous bases within nucleic acids (what we now call DNA and RNA). With Quentin Deming at Columbia University, she identified cholesterol as an underlying cause of heart attacks.

After she moved to Albert Einstein College of Medicine in New York City, Daly extensively studied hypertension and later analyzed how muscle cells use creatine to produce energy. She participated in a study that identified lesions in the lungs of a dog model of chronic cigarette smoking.

Daly’s studies were rigorous, her results important and her topics varied.

Various anthologies from the 1990s and online articles from the 2000s include some details about her personal life, but they largely reiterate the same handful of facts: Daly was born in Queens, N.Y., in 1921; she read microbiologist Paul de Kruif’s classic 1926 book Microbe Hunters as a child; she sought a doctorate in chemistry because she didn’t think she’d have luck getting a job during World War II. In addition to her research and teaching, Daly organized training programs to prepare minority undergraduates for medical school and graduate science programs.

In a letter from 1970, Abraham White of Albert Einstein College of Medicine, where Daly remained until her retirement in 1986, recommends Daly for promotion, citing her “high qualities of leadership,” valuable scientific contributions and administration of the Martin Luther King, Jr.–Robert F. Kennedy Program for Special Studies to recruit and prepare minority students for medical school. It’s one of only two primary documents the college had.

I couldn’t find anyone to speak about Daly — nor could I find any existing interviews. Sibrina Collins, a chemist, writer and executive director of the Marburger STEM Center at Lawrence Technological University in Southfield, Mich., encountered similar frustrations when she wrote about Daly in 2017. Collins found few existing details on Daly’s life aside from the oft-repeated headline about her Ph.D. in chemistry. “It’s wonderful to say that somebody is the first to do something — that’s a nice historical fact — but it’s really important to highlight what they actually did, not just that they were the first,” Collins says.

It’s wonderful to say that somebody is the first to do something … but it’s really important to highlight what they actually did, not just that they were the first.

Sibrina Collins

A profile by Janet P. Stamatel, originally written in 2002 for a book series called Contemporary Black Biography, includes actual quotes from Daly. Stamatel, now a sociologist at the University of Kentucky in Lexington, says she believes she interviewed Daly for that story, but any notes or recording from the interview are long lost.

And so Daly’s voice might also be lost. While we can read her papers and recite a few basic facts, there’s a whole wealth of her life missing. We know nothing of her motivations, convictions, failures and hopes for the future. We can imagine the great challenges she confronted as a woman and a Black scientist in the mid-1900s, but we don’t know how she approached and overcame them. Nor do we know the specifics that drove her to ask certain scientific questions. For instance, why did Daly work on a single study about smoking and lung cancer, a topic seemingly far-flung from her other work? Was she inspired by a loved one with cancer?

The whole research effort left me thinking about the stories society tells about science — whose stories are told, how and by whom. We need to prioritize documenting the stories of scientists, especially of scientists from historically marginalized groups, when and where they do their work. The media, historians, libraries, non-profit organizations, scientists, society as a whole — we can all do better to present opportunities for underrepresented scientists to share their voices and perspectives. Otherwise, we risk losing them altogether.

David Caruso, director of the Center for Oral History at the Science History Institute in Philadelphia, and colleagues have been working to collect those stories, and it takes a concerted effort, he says. Of 722 interviews within the center’s collections, for example, 96 participants identify as female and 20 identify as African American, Caruso says. Following a multiyear effort to correct the bias in its collections, the organization now makes sure its current efforts are representative of diversity in the scientific and engineering communities, he adds. “Our collection still needs work, but it is improved significantly from what it once was.”

I still think about Daly from time to time, and the questions I would have asked given the chance to interview her. She was a real, feeling scientist driven by passions and shaped by a particular time and place. Her achievement in chemistry is inspiring, but her deeper story is lost to students and scientists who might have learned from her experiences.

INTERSECTIONALITY

How climbers help scientists vibe with Utah’s famous red rock formations

The work provides new insights on the geologic structures’ seismic stability

Castleton Tower (right), a soaring sandstone formation near Moab, Utah, is among the most popular climbing destinations in the world. Researchers have enlisted rock climbers to help them assess the natural vibrations of Castleton and other similar geologic structures.
46053374@N05/FLICKR.COM (CC BY-2.0)


By Rachel Crowell
MARCH 21, 2022 

As Kathryn Vollinger prepared to climb Castleton Tower, a 120-meter-tall sandstone formation in the desert near Moab, Utah, the outdoor guide assessed her gear. Ropes? Check. Helmet and harnesses? Check. Climbing rack? Check. That day in March 2018, Vollinger’s checklist also included an unusual piece of equipment: a seismometer. The excursion wasn’t solely for pleasure; it was also for science.

Castleton Tower and its peers may appear still. But these soaring geologic structures are in constant motion, vibrating in response to earthquakes, human activity and even distant ocean waves. The same goes for fins, rock formations that are irregularly shaped instead of cylindrical or rectangular like towers, says geophysicist Riley Finnegan of the University of Utah in Salt Lake City.

The seismometers measure how much the towers and fins naturally vibrate. Those data are key to assessing the formations’ stability and could even help researchers search the rocks for possible signs of seismic activity in the distant past (SN: 3/15/06).

Such insights are important not just to scientists, but also to Native Americans, including the Eastern Shoshone, Hopi, Navajo, Southern Paiute, Ute and Zuni peoples. Many of the landforms, which are located on the traditional lands of these groups, hold cultural and religious significance, Finnegan says.

Finnegan’s team has been working with Vollinger for nearly five years to assemble the first dataset on the dynamic physical properties of 14 towers and fins, which the researchers published February 16 in Seismological Research Letters. Without experienced climbers like Vollinger on board, the project wouldn’t have been possible, Finnegan says.

Collecting the data was a tremendous challenge. Safely scaling the trickiest formations requires climbing chops, strength, endurance and a sizeable dose of planning. “There’s only so much risk I’m willing to take for getting those seismometers up,” Vollinger says. “When you’re hauling extra gear, that adds another element to it.”

Vollinger and her climbing partner, husband Nathan Richman, had to ensure that the rock faces were vertical enough to avoid dragging the equipment. Dragging would “likely knock loose rock off,” she says. Once Vollinger reached the top of a formation — after anywhere from one to six hours of climbing — she read books or chatted with her husband while a seismometer collected data. They then hauled the instrument and their other gear back down.

Back at the University of Utah, Finnegan and colleagues analyzed the data, finding that the structures’ lowest natural frequencies — called fundamental frequencies — range from 0.8 to 15 hertz. In other words, the towers sway roughly one to 15 times per second.

The team also used computer models to study the ways in which the formations bend and twist at a given frequency. Those simulations helped provide a more complete picture of how physics influences the behavior of towers and fins, Finnegan says.

Outdoor guide Kathryn Vollinger carries equipment through rough terrain on the way to climb one of Utah’s many red rock tower formations. Vollinger has been helping geophysicists study the geologic structures for nearly five years.

N. RICHMAN

What’s more, inputting the height, density, cross-sectional area and other material properties of the formations into the model predicted the formations’ fundamental frequencies.

The findings “strengthen our understanding of the dependence on height and width for the [fundamental frequencies] of these features,” says Ramon Arrowsmith, a geologist at Arizona State University in Tempe who wasn’t involved with the work. Finnegan and her colleagues have proven that “the geometry is sufficient to really talk about the dominant frequencies for the behavior of the pillars.”

Eventually, such a model could eliminate the need for climbers to deploy seismometers to measure frequency. And should future scientists require seismic measurements, Arrowsmith envisions robots putting seismometers in place and drones flying by to collect data later. But for now, Vollinger will continue scaling these formations for science.

sciencenews.org

CITATIONS

R. Finnegan et al. Ambient vibration modal analysis of natural rock towers and fins. Seismological Research Letters. Published online February 16, 2022. doi: 10.1785/0220210325.

Tiny Star Unleashes Monstrous Beam of Matter and Anti-Matter

By CHANDRA X-RAY OBSERVATORY MARCH 26, 2022

J2030 X-Ray and Optical. Credit: X-ray: NASA/CXC/Stanford Univ./M. de Vries; Optical: NSF/AURA/Gemini Consortium

• A city-sized collapsed star has generated a beam of matter and antimatter that stretches for trillions of miles.
• Data from NASA’s Chandra X-ray Observatory revealed the full extent of this beam, or filament.
• This discovery could help explain the presence of positrons detected throughout the Milky Way galaxy and here on Earth.
• Positrons are the antimatter counterpart to the electron.

This image from NASA’s Chandra X-ray Observatory and ground-based optical telescopes shows an extremely long beam, or filament, of matter and antimatter extending from a relatively tiny pulsar. With its tremendous scale, this beam may help explain the surprisingly large numbers of positrons, the antimatter counterparts to electrons, scientists have detected throughout the Milky Way galaxy.

In the image at the top of the page, the panel on the left displays about one third the length of the beam from the pulsar known as PSR J2030+4415 (J2030 for short), which is located about 1,600 light years from Earth. J2030 is a dense, city-sized object that formed from the collapse of a massive star and currently spins about three times per second. X-rays from Chandra (blue) show where particles flowing from the pulsar along magnetic field lines are moving at about a third the speed of light. A close-up view of the pulsar in the right panel shows the X-rays created by particles flying around the pulsar itself. As the pulsar moves through space at about a million miles an hour, some of these particles escape and create the long filament. In both panels, optical light data from the Gemini telescope on Mauna Kea in Hawaii have been used and appear red, brown, and black. The full length of the filament is shown in a separate image (below).

J2030 X-Ray and Optical wide fieldCredit: NASA/CXC/Stanford Univ./M. de Vries

The vast majority of the Universe consists of ordinary matter rather than antimatter. Scientists, however, continue to find evidence for relatively large numbers of positrons in detectors on Earth, which leads to the question: what are possible sources of this antimatter? The researchers in the new Chandra study of J2030 think that pulsars like it may be one answer. The combination of two extremes — fast rotation and high magnetic fields of pulsars — lead to particle acceleration and high energy radiation that creates electron and positron pairs. (The usual process of converting mass into energy famously determined by Einstein’s E = mc² equation is reversed, and energy is converted into mass.)

J2030 X-Ray full field. Credit: NASA/CXC/Stanford Univ./M. de Vries

Pulsars generate winds of charged particles that are usually confined within their powerful magnetic fields. The pulsar is traveling through interstellar space at about half a million miles per hour, with the wind trailing behind it. A bow shock of gas moves along in front of the pulsar, similar to the pile-up of water in front of a moving boat. However, about 20 to 30 years ago the bow shock’s motion appears to have stalled and the pulsar caught up to it.

J2030 X-Ray and Optical close-up. Credit: X-ray: NASA/CXC/Stanford Univ./M. de Vries; Optical: NSF/AURA/Gemini Consortium

The ensuing collision likely triggered a particle leak, where the pulsar wind’s magnetic field linked up with the interstellar magnetic field. As a result, the high-energy electrons and positrons could have squirted out through a “nozzle” formed by connection into the Galaxy.

Previously, astronomers have observed large halos around nearby pulsars in gamma-ray light that imply energetic positrons generally have difficulty leaking out into the Galaxy. This undercut the idea that pulsars explain the positron excess that scientists detect. However, pulsar filaments that have recently been discovered, like J2030, show that particles actually can escape into interstellar space, and eventually could reach Earth.

For more on this discovery, see Tiny Star Unleashes Gargantuan Beam of Matter and Anti-Matter That Stretches for 40 Trillion Miles.

Reference: “The Long Filament of PSR J2030+4415” by Martijn de Vries and Roger W. Romani, Accepted, The Astrophysical Journal.
arXiv:2202.03506

A paper describing these results, authored by Martjin de Vries and Roger Romani of Stanford University, will appear in The Astrophysical Journal. NASA’s Marshall Space Flight Center manages the Chandra program. The Smithsonian Astrophysical Observatory’s Chandra X-ray Center controls science operations from Cambridge, Massachusetts, and flight operations from Burlington, Massachusetts.