Category: Science

WASHINGTON — The Defense Advanced Research Projects Agency on June 12 launched four satellites for a technology demonstration in low Earth orbit.

The satellites flew to orbit on the SpaceX Transporter-8 rideshare. They are part of the Blackjack experiment the agency started in 2017 to prove out the utility of commercial space technologies for military applications.  

Once envisioned as a 20-satellite constellation with different types of mission payloads, Blackjack has been reduced in scope and will only deploy four spacecraft. 

The vision DARPA laid out in 2017 for the Blackjack project — to show the Pentagon how it could harness the commercial space revolution — has been overtaken by events, as the U.S. Space Force’s Space Development Agency already is on its way to deploy a LEO constellation for the Defense Department.

The first Blackjack launch had been planned for 2021 but the schedule kept moving to the right due to supply chain problems.

Blackjack program manager Stephen Forbes confirmed that DARPA does not expect to add more satellites to the experiment beyond the four that launched on Monday. 

“At this time, this is our only planned launch for Blackjack,” he said in a statement to SpaceNews.

“The satellites will undergo several months of commissioning, followed by orbit raising, and then start demonstrations of interactions involving proliferated satellite architectures,” Forbes said. 

Blue Canyon buses, SEAKR and CACI payloads

The four identical Blackjack satellites were built on commercial Saturn-class buses made by Blue Canyon, a subsidiary of Raytheon Technologies.

DARPA in 2020 awarded Blue Canyon Technologies a $14.1 million contract to manufacture four satellites. The contract had options worth $99 million for up to 20 satellites. The Saturn-class small satellite buses  can carry payloads of up to 200 kilograms. 

Each Blackjack satellite has a Pit Boss data processing node and a Storm King radio-frequency payload made by SEAKR Engineering, also a Raytheon subsidiary.

There are four laser communications terminals on each satellite, supplied by CACI. 

“The goal is to demonstrate low-Earth orbit performance on par with current systems in geosynchronous orbit while the payloads meet size, weight, and power constraints of the commercial bus,” said Forbes.

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As artificial intelligence takes center stage in the technology landscape, U.S. national security agencies see huge opportunities but also frightening risks.

The rise of AI — and what it means for the future of intelligence — was a hot topic at the recent GEOINT 2023 conference held in St. Louis.

During a panel discussion, officials from the National Geospatial-Intelligence Agency hailed the value of AI tools and machine learning to analyze thousands of satellite images and quickly unravel critical insights. They also alluded to the dark side of AI and the danger it creates when it’s exploited for misinformation.

“The future of geoint is about going faster; it’s about using artificial intelligence,” said James Griffith, NGA’s director of source operations and management. He noted that NGA is responsible for collecting, analyzing and distributing data in support of national security as well as civilian agencies.

Philip Sage, director of NGA’s analytics technology office, said there is a growing realization that in the age of deepfakes, the agency has to make the safety of geoint products a top priority.

Sage commented that he and many of his NGA colleagues were alarmed by news reports May 22 that a phony image of an explosion at the Pentagon, generated by artificial intelligence, was shared by a verified Twitter account with a blue check mark that falsely claimed it was associated with Bloomberg News. This led to widespread confusion and a brief dip in the stock market before authorities confirmed no explosion had occurred.

“It was a terrifying tweet,” said Sage, and a reminder of how easily images are manipulated for nefarious purposes.

“Data assurance, that’s something that we do within this agency very well,” he said. But AI is going to put the system to the test.

The bogus image of the Pentagon on fire was “a very simple and straightforward example of some of the things that we’re seeing today,” said Sage. While that particular item was swiftly debunked as a fake, there may be other instances where counterfeit data is less obvious and more difficult to detect.

“In our foundation models, we’re trying to discover ways to determine if bias is actually being introduced into these models,” said Sage. “If bias is being introduced, how can we discover it quickly and remove it?” He called that an emerging challenge for the intelligence professionals.

A made-up image of a Pentagon explosion is just an inkling of what’s to come, said Jay Moeder, senior geoint adviser at NGA.

“We have to be on the outlook for those little things” that could lead to erroneous analysis of pixels on satellite images, said Moeder.

As NGA increasingly relies on commercial data and analytics support from the private sector, data integrity is going to require collaboration between government and industry, he said. “One of the challenges we all face together is the integrity of the data.”

Much of the talk about AI today is about what human jobs it will replace. At NGA, the bigger concern is how the agency will prepare its workforce to harness the new technologies and understand the risks.

What’s happening with AI is “a big deal,” said Mark Munsell, director of data and digital innovation at NGA.

“It’s going to scale as fast as we can throw compute power at it,” he said. “In our community, we’re learning to apply those techniques being used to build large language models to imagery.”

Munsell said the rapid growth of AI is going to create a demand for “super analysts” who can leverage models built with all the available knowledge and data about every U.S. intelligence problem and can accurately identify objects of interest on imagery “with a level of precision that we haven’t seen before.”

More importantly, these super analysts will have to ensure the data can be trusted.

This article originally appeared in the ‘On National Security’ commentary feature in the June 2023 issue of SpaceNews magazine.

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Scientists have developed a long-lasting battery made with nickel.

The discovery could reduce or even eliminate the use of cobalt in the batteries that power electric cars and other products.

Cobalt is often mined using child labor.

“Nickel doesn’t have child labor issues,” says Huolin Xin, professor of physics and astronomy at the University of California, Irvine.

The method could usher in a new, less controversial generation of lithium-ion batteries.

Until now, nickel wasn’t a practical substitute because large amounts of it were required to create lithium batteries, Xin says. And the metal’s cost keeps climbing.

To become an economically viable alternative to cobalt, nickel-based batteries needed to use as little nickel as possible.

“We’re the first group to start going in a low-nickel direction,” Xin says. “In a previous study by my group, we came up with a novel solution to fully eliminate cobalt. But that formulation still relied on a lot of nickel.”

To solve that problem, Xin’s team spent three years devising a process called “complex concentrated doping” that enabled the scientists to alter the key chemical formula in lithium-ion batteries as easily as one might adjust seasonings in a recipe.

The doping process, Xin explains, eliminates the need for cobalt in commercial components critical for lithium-ion battery functioning and replaces it with nickel.

“Doping also increases the efficiency of nickel,” says Xin, which means EV batteries now require less nickel to work—something that will help make the metal a more attractive alternative to cobalt-based batteries.

Xin says he thinks the new nickel chemistry will quickly start transforming the lithium-ion battery industry. Already, he says, electric vehicle companies are planning to take his team’s published results and replicate them.

“EV makers are very excited about low-nickel batteries, and a lot of EV companies want to validate this technique,” Xin says. “They want to do safety tests.”

The study appears in the journal Nature Energy.

Source: UC Irvine

A new finding contradicts previous assumptions about the role of mobile plate tectonics in the development of life on Earth.

Scientists have used tiny mineral crystals called zircons to study plate tectonics billions of years ago. The research sheds light on the conditions that existed in early Earth, revealing a complex interplay among Earth’s crust, core, and the emergence of life.

Plate tectonics allows heat from Earth’s interior to escape to the surface, forming continents and other geological features necessary for life to emerge. Accordingly, “there has been the assumption that plate tectonics is necessary for life,” says John Tarduno, professor of geophysics at the University of Rochester. But new research casts doubt on that assumption.

Tarduno is lead author of a paper in Nature examining plate tectonics from a time 3.9 billion years ago, when scientists believe the first traces of life appeared on Earth. The researchers found that mobile plate tectonics was not occurring during this time. Instead, they discovered, Earth was releasing heat through what is known as a stagnant lid regime. The results indicate that although plate tectonics is a key factor for sustaining life on Earth, it is not a requirement for life to originate on a terrestrial-like planet.

“We found there wasn’t plate tectonics when life is first thought to originate, and that there wasn’t plate tectonics for hundreds of millions of years after,” says Tarduno. “Our data suggests that when we’re looking for exoplanets that harbor life, the planets do not necessarily need to have plate tectonics.”

Clues in zircons

The researchers didn’t set out to study plate tectonics.

“We were studying the magnetization of zircons because we were studying Earth’s magnetic field,” Tarduno says.

Zircons are tiny crystals containing magnetic particles that can lock in the magnetization of Earth at the time the zircons were formed. By dating the zircons, researchers can construct a timeline tracing the development of Earth’s magnetic field.

The strength and direction of Earth’s magnetic field change depending on latitude. For example, the current magnetic field is strongest at the poles and weakest at the equator. Armed with information about zircons’ magnetic properties, scientists can infer the relative latitudes at which the zircons formed. That is, if the efficiency of the geodynamo—the process generating the magnetic field—is constant and the intensity of the field is changing over a period, the latitude at which the zircons formed must also be changing.

But Tarduno and his team discovered the opposite: the zircons they studied from South Africa indicated that during the period from about 3.9 to 3.4 billion years ago, the strength of the magnetic field did not change, which means the latitudes did not change either.

Because plate tectonics includes changes in latitudes of various land masses, Tarduno says, “plate tectonic motions likely weren’t occurring during this time and there must have been another way Earth was removing heat.”

Further reinforcing their findings, the researchers found the same patterns in zircons they studied from Western Australia.

“We aren’t saying the zircons formed on the same continent, but it looks like they formed at the same unchanging latitude, which strengthens our argument that there wasn’t plate tectonic motion occurring at this time,” Tarduno says.

Stagnant lid tectonics

Earth is a heat engine, and plate tectonics is ultimately the release of heat from Earth. But stagnant lid tectonics—which results in cracks in Earth’s surface—are another means allowing heat to escape from the interior of the planet to form continents and other geological features.

Plate tectonics involves the horizontal movement and interaction of large plates on Earth’s surface. Tarduno and his colleagues report that, on average, plates from the last 600 million years have moved at least 8,500 kilometers (5,280 miles) in latitude. In contrast, stagnant lid tectonics describes how the outermost layer of Earth behaves like a stagnant lid, without active horizontal plate motion. Instead, the outer layer remains in place while the interior of the planet cools. Large plumes of molten material originating in Earth’s deep interior can cause the outer layer to crack. Stagnant lid tectonics is not as effective as plate tectonics at releasing heat from Earth’s mantle, but it can still lead to the formation of continents.

“Early Earth was not a planet where everything was dead on the surface,” Tarduno says. “Things were still happening on Earth’s surface; our research indicates they just weren’t happening through plate tectonics. We had at least enough geochemical cycling provided by the stagnant lid processes to produce conditions suitable for the origin of life.”

Plate tectonics and and other planets

While Earth is the only known planet to experience plate tectonics, other planets, such as Venus, experience stagnant lid tectonics, Tarduno says.

“People have tended to think that stagnant lid tectonics would not build a habitable planet because of what is happening on Venus,” he says. “Venus is not a very nice place to live: it has a crushing carbon dioxide atmosphere and sulfuric acid clouds. This is because heat is not being removed effectively from the planet’s surface.”

Without plate tectonics, Earth may have met a similar fate. While the researchers hint that plate tectonics may have started on Earth soon after 3.4 billion years, the geology community is divided on a specific date.

“We think plate tectonics, in the long run, is important for removing heat, generating the magnetic field, and keeping things habitable on our planet,” Tarduno says. “But, in the beginning, and a billion years after, our data indicates that we didn’t need plate tectonics.”

Funding for the research came from the National Science Foundation.

Source: University of Rochester

People who did light exercise within 48 hours of a concussion had their symptoms resolve in about half the time as those who waited more than a week to exercise, a new study finds.

The study adds to the growing body of science that suggests that “cocoon therapy”—bed rest in the dark with minimal mental stimulation after concussion—isn’t good for patients.

Instead, when done under the guidance of a trained clinician, exercise is preferable, says Landon Lempke, a research fellow with appointments at the University of Michigan Concussion Center and the Exercise and Sport Science Initiative, both housed in the School of Kinesiology and first author of the study in the journal Sports Medicine.

The observational study monitored more than 1,200 college athletes at 30 institutions nationwide before injury and at injury until medical clearance. The study wasn’t designed to establish a causal relationship between exercise and concussion recovery, but the findings are in line with previous smaller, randomized controlled trials identifying similar relationships.

• Athletes who began light exercise within 48 hours were considerably more likely to see symptoms resolve than those who did not exercise, with about 2.5 days faster symptom recovery time.
• Athletes who started exercising roughly eight days or later after injury were significantly less likely to experience symptom recovery than those who did not exercise, and took about five days longer to recover.

The biggest beneficiaries of early exercise might be people who are likely to develop persistent concussion symptoms–those that linger past four weeks, Lempke says.

• Athletes in the early exercise group had lower prevalence (3%-4%) of persistent symptoms compared to the no exercise group.
• The late exercise group experienced 11% greater persistent symptom prevalence than the no exercise group.

For two decades, it’s been suggested that people with concussions should avoid physical and mental activity while symptomatic and recovering, Lempke says. The concern was that athletes who returned to play too soon risked another concussion and a more serious injury called second impact syndrome, a rare but serious complication that can result in death. Some research also suggested that aggressive exercise could prolong recovery.

That viewpoint evolved as the benefits of early exercise became clear. In 2017, international consensus and return to play guidelines were modified to recommend light physical and mental activities after the 24- to 48-hour recovery window as long as it did not worsen symptoms.

Lempke stresses that the findings don’t mean that athletes return to play sooner. Progressive return-to-play protocols should always be followed. All exercise after a concussion and during recovery should be supervised by a trained clinician. The Buffalo Concussion Treadmill Test is the most frequently used and studied post recovery exercise protocol.

Participants start walking at 3.3 mph and increase the incline until symptoms start to increase, which is their exercise threshold. Patients then exercise five to six times a week at 80% of their maximum heart rate that initially increased those symptoms.

“Based on the historical background, the adage ‘the dosage makes the poison’ applies to exercise after concussion,” Lempke says. “Too much, too soon” or “too little, too late” can both be detrimental. This observational study did not identify the type, duration, or intensity of exercise, but it did identify a clear positive effect of exercise on recovery times.

“There is likely a Goldilocks zone that is slightly unique to every individual,” Lempke says. “For athletes, delaying or choosing not to report your concussion is directly tied to longer recovery as well as potential negative consequences. So reporting is the first step,” Lempke says.

“For health care providers, it’s important to stay current on concussion assessment and management practices. Clinicians still use ‘cocoon therapy’ despite known deleterious effects. Our present findings and many other studies indicate exercise can be started before symptoms resolve, if done in a safe and controlled manner as guided by a trained clinician.”

Source: University of Michigan

Researchers report that water on Enceladus, one of Saturn’s moons, holds phosphates.

The team used data from NASA’s Cassini space mission to detect evidence of phosphates in particles ejected from the moon’s ice-covered global ocean.

Phosphorus, in the form of phosphates, is vital for all life on Earth. It forms the backbone of DNA and is part of cell membranes and bones. The new study in Nature is the first to report direct evidence of phosphorus on an extraterrestrial ocean world.

The team found that phosphate is present in Enceladus’ ocean at levels at least 100 times higher—and perhaps 1,000 times higher—than in Earth’s oceans.

“By determining such high phosphate concentrations readily available in Enceladus’ ocean, we have now satisfied what is generally considered one of the strictest requirements in establishing whether celestial bodies are habitable,” says third author Fabian Klenner, a postdoctoral researcher in Earth and space sciences at the University of Washington.

“This is the first finding of phosphorus on an extraterrestrial ocean world.”

While at Freie Universität Berlin, Klenner did experiments that revealed the high phosphate concentrations present in Enceladus’ ocean.

One of the most profound discoveries in planetary science over the past 25 years is that worlds with oceans beneath a surface layer of ice are common in our solar system. These ice-covered celestial bodies include the icy moons of Jupiter and Saturn—including Ganymede, Titan, and Enceladus—as well as even more distant celestial bodies, like Pluto.

NASA’s Cassini mission explored Saturn, its rings and its moons from 2004 to 2017. It first discovered that Enceladus’ harbors an ice-covered watery ocean, and analyzed material that erupted through cracks in the region of the moon’s south pole.

The spacecraft was equipped with the Cosmic Dust Analyzer that analyzed individual ice grains emitted from Enceladus and sent those measurements back to Earth. To determine the chemical composition of the grains, Klenner used a specialized setup in Berlin that mimicked the data generated by an ice grain hitting the instrument. He tried different chemical compositions and concentrations for his samples to try to match the unknown signatures in the spacecraft’s observations.

“I prepared different phosphate solutions, and did the measurements, and we hit the bullseye. This was in perfect match with the data from space,” Klenner says. “This is the first finding of phosphorus on an extraterrestrial ocean world.”

Planets with surface oceans, like Earth, must reside within a narrow range of distances from their host stars (in what is known as the “habitable zone“) to maintain temperatures at which water neither evaporates nor freezes. Worlds with an interior ocean like Enceladus, however, can occur over a much wider range of distances, greatly expanding the number of habitable worlds likely to exist across the galaxy.

In previous studies, the team at the Freie Universität Berlin determined that Enceladus harbors a “soda ocean,” rich in dissolved carbonates, that also contains a vast variety of reactive and sometimes complex carbon-containing compounds. The team also found indications of hydrothermal environments on the seafloor.

The new study now shows the unmistakable signatures of dissolved phosphates.

“Previous geochemical models were divided on the question of whether Enceladus’ ocean contains significant quantities of phosphates at all,” says lead author Frank Postberg at Freie Universität Berlin. “These measurements leave no doubt that substantial quantities of this essential substance are present in the ocean water.”

To investigate how the ocean on Enceladus can maintain such high concentrations of phosphate, geochemical lab experiments and modeling included in the new paper were conducted by a Japan-based team led by second author Yasuhito Sekine at the Tokyo Institute of Technology and a US-based team led by fourth author Christopher Glein at the Southwest Research Institute in San Antonio, Texas.

Source: University of Washington

Most mothers don’t worry excessively about bonding with a second baby or whether they’ll love each child equally, research finds.

The new study, however, uncovered some psychological risks among those moms who do worry.

The findings are contrary to a widely held belief that it is common and normal for women to be worried about loving their second baby as much as they currently love their first child. Although some mothers may worry a little if they can form an attachment to their second baby, such feelings are “not common and universal,” says Brenda Volling, psychology professor at the University of Michigan and the study’s lead author.

The study in the Infant Mental Health Journal focuses on 240 pregnant mothers expecting their second baby. About 70% of the mothers reported they did not worry at all about forming an attachment to their second baby—what the authors referred to as maternal-fetal relationship anxiety, or MFRA. On the other hand, about 20% worried a little, while 5% of the mothers worried “very much” or were “extremely” worried.

Volling, whose research focuses on early social and emotional development and parent-child interaction, says the women who experienced high levels of anxiety also had other psychosocial risks in their lives—including more depression, more conflict in their marriages, and their firstborn children had less secure attachments.

“These mothers also held more ambivalent and avoidant attachment styles themselves, based on their own childhood attachment experiences,” she says.

To overcome excessive anxiety and feelings of insecurity in close social relationships, mothers may wish to seek professional help from care providers or join support groups. Coming to understand the source of these insecurities “would most likely free them to feel closer to their babies,” Volling says.

The media also have a role in the perception of maternal mental health issues—sometimes negatively. In fact, Volling says blogs and articles about what moms can expect when having their second baby have made it difficult for mothers to seek help and support by claiming it was normal for mothers to feel less attached to their second babies.

“I was very concerned that we were doing a disservice to these women by telling them ‘not to worry,’ ‘it was completely normal,’ and ‘everything would change once the baby was born,’” she says.

Fathers’ attachment to their children is also important—and there are similarities to mothers’ attachment to the unborn baby.

“Fathers who are also depressed during the perinatal period can have difficulties establishing an attachment to the baby during pregnancy, and this does not appear to be because men themselves are not the pregnant parent,” Volling says.

As is the case for mothers, it is the social support and relationship risks surrounding these men that matter, she says.

The study’s coauthors are from the University of North Texas Health Science Center; Mathematica; and the Institute for Advanced Study in Toulouse.

Source: University of Michigan

American judges still cite property cases of enslaved Black people as good law 160 years after the Emancipation Proclamation.

When Justin Simard was conducting research for his dissertation, he came across a case predating the Civil War related to slavery that was cited as precedent in 2012. He started looking for other slavery citations from the past 30 years, thinking he’d find one or two. Instead, he found more than 300.

“What I thought would be a footnote in my dissertation highlighting the odd decisions of a few judges turned into a broader examination of the legal profession’s treatment of slave cases,” says Simard, assistant professor of law at Michigan State University. “Not only are we ratifying their treatment as property in the past but also continuing to treat them as property in the present.”

Simard started the Citing Slavery Project to document the history and continued legacy of the law of slavery in the United States.

To date, Simard and his team of law students have found more than 7,000 cases involving enslaved people and have created a database of cases from the 20th and 21st centuries that continue to cite them as precedent.

“One of the most surprising things I’ve found is how extensively these cases are cited for so many different reasons,” Simard says. “There’s just so many areas of law—criminal law, property law, criminal procedure—all because in the 19th century, there were so many slave cases. And this is such an important formative era in making American law that just basic ground rules are established in that time. In just about any legal issue you can think of, cases of enslaved people are cited.”

Simard explains that the American legal system is a common law system, meaning that decisions made today are built on decisions of the past. So, when a judge or lawyer has a question, they look back to find comparable questions that have been answered in the past. When they find cases, judges “cite” a case as a way of presenting a similar example.

However, Simard says that in 80% of the cases his team identified, there’s no reference that the citations involve enslaved people.

“This was a tragic era in our country’s history, and if lawyers and judges today are continuing to cite slavery cases without acknowledging them as cases concerning enslaved people, they are papering over that era,” Simard says. “It’s a big blind spot. They want to treat these cases as ordinary law.”

Simard says citing slavery cases without acknowledging it “blurs the boundary between people and property.”

For example, a citation about damage to a car or damage to a dump truck that uses precedent about damage to an enslaved person dehumanizes the enslaved person—they’re all basically treated the same.

“Judges today must understand that many judges of the pre-Civil War era were slave owners themselves and made decisions within this context,” Simard says. “And, all of these cases were abrogated, at least in part, by the 13th Amendment, but judges fail to recognize the relevance of emancipation to their decisions.”

Simard and his research team of law students recently found that of all published legal cases throughout American history, 18% are what he calls “two-step” cases—those that cited a case that in turn cited a slavery case to support its argument. And beyond that, he estimates between 30% and 40% of all American legal cases are three-step cases. Simard’s article, “The Precedential Weight of Slavery,” will appear in the journal NYU Review of Law and Social Change.

Compelled to create awareness of enslaved citations, Simard’s team successfully lobbied the editors of “The Bluebook,” the legal profession’s citation bible, to change its rules in its 2021 edition, requiring cases involving enslaved people to be identified with the notation “(enslaved party)” or “(enslaved person at issue).”

“To stop citing these cases without acknowledgement is the first step, but to actually address the underlying issues is a much broader problem,” Simard says.

The legal profession must confront its role in slavery, Simard says.

“American slavery generated thousands of legal disputes,” he says. “Lawyers legitimized slavery by fitting cases involving enslaved people into standard legal categories. Even after emancipation, lawyers continued to treat slave cases as good law. And, today, American judges and lawyers continue to cite slave cases for fundamental legal propositions. It’s likely no coincidence that the legal system continues to create and enforce racial disparities.”

Simard says the law profession loves to pat itself on the back for the role it played in the civil rights movement, but what about the decades before that?

“The pervasive influence of the law of slavery on contemporary American law raises hard questions about what it means to acknowledge and redress the terrible damage that slavery inflicted,” Simard says. “It also raises questions about the law these decisions helped create. Scholars and judges have mostly avoided these questions by treating slave cases, especially those involving routine legal matters, as ordinary law.

“Slave cases are too deeply entwined in American law to completely excise their influence, but ignoring that influence should no longer be an option.”

Source: Michigan State University

The world’s first transgenic ants have olfactory sensory neurons that flash green in response to odorants.

Ants navigate their richly aromatic world using an array of odor receptors and chemical signals called pheromones. Whether foraging or defending the nest, mating or tending to their young, ants both send and receive chemical signals throughout their lives. And the ant brain is well equipped to process the abundance of scents: The olfactory processing center in the ant’s brain has 10 times as many subdivisions as those of fruit flies, for example, even though their brains are about the same size.

And yet how the ant olfactory system encodes scent data has remained largely unknown.

Contrary to previous findings, the new study in Cell finds that only a few specific areas of the olfactory system lit up in response to alarm pheromones, danger signals that elicit panic and nest evacuation. The results raise questions about how sensory information is processed in the ant brain—as well as tantalizing possibilities for revealing what hundreds of other odorant receptors are up to.

“Neurogenetic tools have revolutionized the field of fruit fly neuroscience over the past decades, while social insect neuroscience has essentially been stuck,” says Daniel Kronauer, head of the Laboratory of Social Evolution and Behavior at Rockefeller University. “Our technical breakthroughs now finally allow us to apply these powerful tools in ants to study their social behavior.”

In the antennae

In 1958, E. O. Wilson reported that a secretion from the mandibular gland of harvester ants triggered their nestmates to quicken their pace and take up colony defense behaviors. He called this response “alarm behavior.” Since then, scientists have documented that alarm behavior and many other complex social activities in ant colonies are regulated by a vast array of pheromones.

Ants’ olfactory receptors are located on neurons in their antennae, which send their input to brain centers called the antennal lobes. The antennal lobes are comprised of specialized structures called glomeruli that are essential to scent processing. Some ants have more than 500 glomeruli—a bounty thought to be related to their heightened ability to perceive and discriminate between pheromones. Previous work from Kronauer’s lab has shown that ants whose odorant receptors have been knocked out cannot respond to pheromone signals.

In this study, the researchers created their transgenic subjects by injecting the eggs of clonal raider ants—a queenless species composed entirely of blind female workers—with genetic material encoding the synthetic protein GCaMP, which lights up neon green when calcium levels change during cellular activity.

“Our goal was to get GCaMP expressed only in a single cell type—the olfactory sensory neurons,” says lead author Taylor Hart, a researcher in Daniel Kronauer’s lab.

This was important because the antennal lobe is composed of multiple cell types: sensory neurons, projection neurons that carry sensory data to other parts of the brain, and lateral interneurons that link everything together. “Those other cell types can make signal-to-noise ratio poor, because they can be doing other activities, such as computations, processing information, and modulating signals,” Hart says. All of this can obscure what the olfactory neurons are doing.

The ant ‘panic button’

While successfully breeding a small group of ants with GCaMP expression in the olfactory sensory neurons, the team also developed a sophisticated two-photon calcium imaging technique that allowed them to record neural activity throughout the entire antennal lobes of live ants for the first time.

The researchers decided to focus on alarm pheromones, because they are particularly volatile and elicit strong and robust behavioral responses. They found that adult ants that detected the scents immediately scrambled to gather as many eggs in their mandibles as they could and then made a break for it, fleeing into an adjacent section of the test chamber.

Hart and her team then used their new techniques to monitor GCaMP fluorescence levels in the antennal lobes of 22 transgenic ants as they exposed them to a range of odors, including the alarm pheromones (which smell fruity to the human nose). The flashes clustered in six glomeruli in one region, suggesting that area may act as the brain’s panic button.

“We were expecting that a large portion of the antennal lobe would show some kind of response to these alarm pheromones,” Hart says. “Instead, we saw that the responses were extremely localized. Most of the antennal lobe did not respond at all.”

Hart says the findings reveal details about how the ant brain processes sensory input. Researchers have wondered whether the activity is privatized, with each glomerulus responding only to one or a few specific stimuli, or distributed, with unique combinations of glomeruli activated by a stimulus. A brain with more than 500 glomeruli that operated in a distributed way, with hundreds of sensors firing at once, would need extraordinary computational power when it comes to sensory processing, Hart says.

“Most of the odors we tested activated only a small proportion of the total glomeruli,” she says. “It seems that privatization is the way in the ant antennal lobe.”

Transgenic ant research to come

Considering that only six glomeruli responded out of 500, Hart wonders, “What do they need all these different glomeruli for? The fruit fly gets by with just 50.”

It will now be easier to find out why ants have a greater need to differentiate odor stimuli than other insects, Kronauer says—and not only because Hart has since bred hundreds of transgenic ants who differ from their wild counterparts only in their ability to signal in fluorescence, providing a robust pool for future research.

“The tools that Taylor developed open up a really big range of questions that were inaccessible to us until now,” he says. These include associating specific glomeruli with the variety of pheromones ants use for things like raiding, recruitment, and distinguishing between nestmates and outsiders. “There are also interesting developmental questions about how the ant olfactory system gets assembled, because it’s so complex. Larvae also have olfactory sensory neurons, so now we can look at their sensory capabilities.”

Source: Rockefeller University

NEW YORK — A United Nations official says there is an opportunity over the next 15 months to improve how nations manage space activities to address emerging issues ranging from orbital debris to space resources.

Speaking at the Secure World Foundation’s Summit for Space Sustainability here June 13, Guy Ryder, U.N. undersecretary-general for policy, said the organization was making efforts to address space diplomacy ahead of a September 2024 U.N. conference called Summit of the Future that will address broad challenges the world is facing.

“We have a window of opportunity over the next 15 months,” he said, “where we can accelerate space diplomacy and advance the governance issue.”

The U.N. released a policy paper in May on outer space governance, outlining several issues it wants to address. Among them are coordination issues for a rapidly growing population of space objects in general in Earth orbit, and more specifically increasing amounts of debris.

“The most obvious and perhaps the most extraordinary change in recent years has been the sheer number of objects being launched into space,” Ryder said. “The fact that more objects have been launched in the last 10 years than in the previous 50 years combined offers, I think, boundless development opportunities and governance needs.”

Those governance needs revolve around space traffic coordination, with limited progress to address that on a global scale. That puts the safety and sustainability of space at risk, he argued, which is exacerbated by the growth of debris, particularly from anti-satellite tests. Efforts to remove debris show promise, but he said that without international norms regarding such activities, “the use of these technologies can be a source both of tension and of conflict.”

Other issues of concern revolve around the human exploration of the moon and utilization of space resources. He noted that while the Committee on the Peaceful Uses of Outer Space (COPUOS) has been examining space resource utilization, there is no agreement yet on how countries and companies can use those resources.

Ryder offered no specific proposals to address those issues, but said meetings by COPUOS and other organizations over the next 15 months offered opportunities to develop proposals to address them ahead of the Summit of the Future, where space will be one of many agenda items.

The goal, he said, is to develop a single unified governance framework that covers space traffic coordination, debris and resource management, as well as norms and rules to avoid armed conflict in outer space. However, he said the U.N. would be open to separate frameworks for each issue “if that path looks likelier to achieve results.”

Ryder said efforts to develop governance mechanisms on the high seas, such as the U.N. Convention on the Law of Sea, offered a model for space. “All of this provides us with the confidence that the kinds of agreements concluded in the past are possible in the future, even in today’s admittedly challenging geopolitical climate.”

Part of the coordination efforts leading up to the Summit of the Future will be a conference hosted by Portugal in the spring of 2024. That is intended to help develop proposals to be presented at the summit, said Hugo André Costa, member of the executive board of the Portuguese Space Agency, during another conference panel.

There will be two virtual workshops ahead of the Portuguese conference, one in October on technology issues and a second in March 2024 on policy issues, to solicit ideas from governments, industry and academia. “This is the only way that we can prepare for the future,” he argued.

There have been discussions about whether COPUOS, with more than 100 member nations operating on a consensus model where all nations need to agree, is suited for the current space environment. “It’s slow, it’s frustrating but ultimately it’s a slow, steady process,” said Valda Vikmanis Keller, director of the U.S. State Department’s Office of Space Affairs, saying the open discussions there remain essential. “It’s the only way forward.”

“We need to continue work that is being done in COPUOS,” said Costa, including “difficult discussions” on these issues. “It’s through the difficult conversations and the difficult discussions that we’re going to have that we can support the work of COPUOS and move forward.”

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