Key findings include:

• Overall past-year recreational ketamine use increased by 81.8% from 2015 to 2019 and by 40% from 2021 to 2022.
• Adults with depression were 80% more likely to have used ketamine in the past year in 2015-2019, but this association weakened in later years. In 2021-2022, ketamine use increased only among those without depression.
• In 2021-2022, adults aged 26-34 were 66% more likely to have used ketamine in the past year compared to adults aged 18-25. Those with college degrees were more than twice as likely to have used ketamine compared to people with a high school education or less.
• People were more likely to use ketamine if they used other substances, such as ecstasy/MDMA, GHB, and cocaine.

The researchers recommend expanding prevention outreach to settings like colleges, where younger adults may be at heightened risk, as well as providing education on the harms of polydrug use, particularly in combination with opioids. As medical ketamine becomes more widely available, they also emphasize the need for continued surveillance of recreational ketamine use patterns and further research to understand the factors that contribute to ketamine use.

The study, published online in the Journal of Affective Disorders, was led by Kevin Yang, M.D., a third-year resident physician in the Department of Psychiatry at UC San Diego School of Medicine. The research was supported by the National Institute on Drug Abuse of the National Institutes of Health.

The study, published in PNAS, addresses major gaps in the human genetic history of the Wallacean Archipelago and West Papuan regions of Indonesia — a region with abundant genetic and linguistic diversity that is comparable to the Eurasian continent — including the analysis of 254 newly sequenced genomes.

In combination with linguistic and archaeological evidence, the study shows that Wallacean societies were transformed by the spread of genes and languages from West Papua in the past 3,500 years — the same period that Austronesian seafarers were actively mixing with Wallacean and Papuan groups.

“My colleagues at the Indonesian Genome Diversity Project have been studying Indonesia’s complex genetic structure for more than a decade, but this comprehensive study provides confirmation that Papuan ancestry is widespread across Wallacea, pointing to historical migrations from New Guinea,” says lead author Dr Gludhug Ariyo Purnomo, from the University of Adelaide’s School of Biological Sciences.

“By connecting the dots between genetics, linguistics, and archaeology, we now recognise West Papua as an important bio-cultural hub and the launching place of historical Papuan seafarers that now contribute up to 60% of modern Wallacean ancestry.”

Genomic research is also becoming increasingly important for developing new medicines tailored to specific genetic backgrounds.

“In the era of precision medicine, understanding the genetic structure of human groups is vital for developing treatments that are helpful rather than harmful, with Wallacea and New Guinea having been poorly represented in past genomic surveys,” Dr Purnomo says.

Associate Professor Ray Tobler, from ANU, says Wallacea had been isolated for more than 45,000 years since the arrival of the first human groups, and the more recently arriving Papuan and Austronesian migrants reconfigured Wallacean culture by introducing new languages that diversified and intermingled to create its rich linguistic landscape.

“Our findings suggest that the Papuan and Austronesian migrations were so extensive that they have largely overwritten the ancestry of the first migrants, making the recovery of these ancient migrations from genetic data challenging,” says Professor Tobler, who is also an Adjunct Fellow at the University of Adelaide’s Australian Centre for Ancient DNA.

According to the researchers, there are challenges in reconstructing past movements of people using modern genetic data due to historical migrations and movements.

“There’s also been so much movement in Wallacea in the past couple of thousand years, due to the spice trade and slavery, that it obscures the relationship between geography and genetics,” Associate Professor Tobler says.

“What we know about Wallacea and New Guinea is just the tip of the iceberg, but the use of ancient DNA can help to overcome some of these challenges and help us to understand the origins and legacy of human journeys to the region stretching back tens of thousands of years.”

But now, a newly described dinosaur whose fossils were uncovered by University of Wisconsin-Madison paleontologists is challenging that narrative, with evidence that the reptiles were present in the northern hemisphere millions of years earlier than previously known.

The UW-Madison team has been analyzing the fossil remains since they were first discovered in 2013 in present-day Wyoming, an area that was near the equator on Laurasia. The creature, named Ahvaytum bahndooiveche, is now the oldest known Laurasian dinosaur, and with fossils estimated to be around 230 million years old, it’s comparable in age to the earliest known Gondwanan dinosaurs.

UW-Madison scientists and their research partners detail their discovery Jan. 8, 2025, in the Zoological Journal of the Linnean Society.

“We have, with these fossils, the oldest equatorial dinosaur in the world — it’s also North America’s oldest dinosaur,” says Dave Lovelace, a research scientist at the University of Wisconsin Geology Museum who co-led the work with graduate student Aaron Kufner.

Discovered in a layer of rock known as the Popo Agie Formation, it took years of careful work by Lovelace and his colleagues to analyze the fossils, establish them as a new dinosaur species and determine their estimated age.

While the team doesn’t have a complete specimen — that’s an exceedingly rare occurrence for early dinosaurs — they did find enough fossils, particularly parts of the species’ legs, to positively identify Ahvaytum bahndooiveche as a dinosaur, and likely as a very early sauropod relative. Sauropods were a group of herbivorous dinosaurs that included some famously gigantic species like those in the aptly named group of titanosaurs. The distantly related Ahvaytum bahndooiveche lived millions of years earlier and was smaller — much smaller.

“It was basically the size of a chicken but with a really long tail,” says Lovelace. “We think of dinosaurs as these giant behemoths, but they didn’t start out that way.”

Indeed, the type specimen of Ahvaytum bahndooiveche, which was full-grown but could have been slightly bigger at its maximum age, stood a little over one foot tall and was around three feet long from head to tail. Although scientists haven’t found its skull material, which could help illuminate what it ate, other closely related early sauropod-line dinosaurs were eating meat and would likely have been omnivorous.

The researchers found the few known bones of Ahvaytum in a layer of rock just a little bit above those of a newly described amphibian that they also discovered. The evidence suggests that Ahvaytum bahndooiveche lived in Laurasia during or soon after a period of immense climatic change known as the Carnian pluvial episode that has previously been connected to an early period of diversification of dinosaur species.

The climate during that period, lasting from about 234 to 232 million years ago, was much wetter than it had been previously, transforming large, hot stretches of desert into more hospitable habitats for early dinosaurs.

Lovelace and his colleagues performed high-precision radioisotopic dating of rocks in the formation that held Ahvaytum’s fossils, which revealed that the dinosaur was present in the northern hemisphere around 230 million years ago. The researchers also found an early dinosaur-like track in slightly older rocks, demonstrating that dinosaurs or their cousins were already in the region a few million years prior to Ahvaytum.

“We’re kind of filling in some of this story, and we’re showing that the ideas that we’ve held for so long — ideas that were supported by the fragmented evidence that we had — weren’t quite right,” Lovelace says. “We now have this piece of evidence that shows dinosaurs were here in the northern hemisphere much earlier than we thought.”

While the scientific team is confident they’ve discovered North America’s oldest dinosaur, it’s also the first dinosaur species to be named in the language of the Eastern Shoshone Tribe, whose ancestral lands include the site where the fossils were found. Eastern Shoshone tribal elders and middle school students were integral to the naming process. Ahvaytum bahndooiveche broadly translates to “long ago dinosaur” in the Shoshone language.

Several tribal members also partnered with Lovelace and his UW-Madison colleagues as the researchers sought to evolve their field practices and better respect the land by incorporating the knowledge and perspectives of the Indigenous peoples into their work.

“The continuous relationship developed between Dr. Lovelace, his team, our school district, and our community is one of the most important outcomes of the discovery and naming of Ahvaytum bahndooiveche,” says Amanda LeClair-Diaz, a co-author on the paper and a member of the Eastern Shoshone and Northern Arapaho Tribes. LeClair-Diaz is the Indian education coordinator at Fort Washakie school and coordinated the naming process with students and tribal elders — a process that started under her predecessor, Lynette St. Clair.

“Typically, the research process in communities, especially Indigenous communities, has been one sided, with the researchers fully benefiting from studies,” says LeClair-Diaz. “The work we have done with Dr. Lovelace breaks this cycle and creates an opportunity for reciprocity in the research process.”

Scientists at The University of Queensland and The University of Sydney have identified widespread resistance to benzimidazole-based dewormers which are commonly used to treat gastrointestinal parasites in dogs.

Dr Swaid Abdullah from UQ’s School of Veterinary Science said almost 70 per cent of the hookworm samples studied showed genetic mutations that can cause drug resistance.

“This is a big problem, as hookworm infections can be dangerous for both humans and animals,” Dr Abdullah said.

“In dogs, hookworm infections primarily affect the small intestine leading to anaemia, diarrhea, and malnutrition.

“But worse still, the parasites can spread to humans through the skin.

“In people, hookworms from dogs can cause cutaneous larva migrans (CLM) disease — or ‘creeping eruption’ — which is a winding, snake-like rash with blisters and itching.”

Dr Abdullah said the best weapons against canine hookworms have been benzimidazole-based dewormers, but they are starting to fail.

“This level of resistance is an urgent issue for pet and public health,” he said.

The study team used advanced parasitological diagnostics to examine samples from more than 100 animals in Australia and New Zealand.

The results showed resistance was spreading through hookworm species including the northern hookworm, which had previously been thought to be unaffected.

Professor Jan Šlapeta from The University of Sydney said routine reliance on deworming drugs is likely fuelling the development of resistance

“Responsible parasite management by veterinarians is going to be vital moving forward,” Professor Šlapeta said.

“We’re calling for a shift toward targeted, risk-based treatment to curb the spread of resistant hookworm.

“Responsible doctors don’t give blanket antibiotics to any and all of their patients, and deworming should be approached in the same way if we’re to limit drug resistance.

“As resistance spreads, we need ongoing monitoring and the development of new control strategies to protect animal and human health.

“This study is a wake-up call for both pet owners and veterinarians alike — the era of effortless parasite control may be coming to an end.”

A research team at Tohoku University used microfluidic devices to reveal how directional connections shape the complex dynamics of neuronal networks. They also developed mathematical models based on experimental data to predict how connectivity influences activity across space and time.

The results were published in Neural Networks on November 28, 2024.

Like a river current, directional connections in neuronal networks propagate signals in a downstream flow from one area to another. A microfluid device has tiny channels that can precisely direct the flow, which can help fabricate neurons that react more similarly to in-vivo models. By studying in-vitro neurons in a lab environment, the research team was able to efficiently and constructively explore whether one-way connections play other fundamental roles in shaping brain dynamics.

“The brain is difficult to understand, in part, because it is dynamic — it can learn to respond differently to the same stimuli over time based on a number of factors,” says lead author Nobuaki Monma.

The research team fabricated neuronal networks bearing modular connectivity (as observed in animals’ nervous systems) and embedded directional connections between modules using microchannels. The connections were embedded in a feedforward manner to minimize excessive excitatory reactions. Using calcium imaging to record spontaneous activity exhibited by the neuronal network, they found that networks incorporating directional connections exhibited more complex activity patterns compared to networks without directionality.

In addition, the researchers developed two mathematical models to clarify the underlying network mechanisms behind biological observations and to predict configurations that would yield greater dynamical complexity. The models determined that the interplay between modularity and connectivity fostered more complex activity patterns.

“The findings of this study are expected not only to deepen our fundamental understanding of neuronal networks in the brain, but also to find applications in fields such as medicine and machine learning,” proposes Associate Professor Hideaki Yamamoto.

This may also offer an in-vitro model for developing biologically plausible artificial neural networks. Further theoretical advancements would also contribute to modeling large-scale networks, which may provide insights to future connectome analysis of the brain. The more thoroughly we understand these neuronal networks, the more it could be used as a trusty tool to unlock the many mysteries of the brain.

Now, researchers at Princeton Engineering and the Indian Institute of Technology have harnessed artificial intelligence to take a key step toward slashing the time and cost of designing new wireless chips and discovering new functionalities to meet expanding demands for better wireless speed and performance. In an article published Dec. 30 in Nature Communications, the researchers describe their methodology, in which an AI creates complicated electromagnetic structures and associated circuits in microchips based on the design parameters. What used to take weeks of highly skilled work can now be accomplished in hours.

What is more, the AI behind the new system has produced strange new designs featuring unusual patterns of circuitry. Kaushik Sengupta, the lead researcher, said the designs were unintuitive and unlikely to be developed by a human mind. But they frequently offer marked improvements over even the best standard chips.

“We are coming up with structures that are complex and looks random shaped and when connected with circuits, they create previously unachievable performance. Humans cannot really understand them, but they can work better,” said Sengupta, a professor of electrical and computer engineering and co-director of NextG, Princeton’s industry partnership program to develop next-generation communications.

These circuits can be engineered towards more energy efficient operation or to make them operable across an enormous frequency range that is not currently possible. Furthermore, the method synthesizes inherently complex structures in minutes, while conventional algorithms may take weeks. In some cases, the new methodology can create structures that are impossible to synthesize with current techniques.

Uday Khankhoje, a co-author and associate professor of electrical engineering at IIT Madras, said the new technique not only delivers efficiency but promises to unlock new approaches to design challenges that have been beyond the capability of engineers.

“This work presents a compelling vision of the future,” he said. “AI powers not just the acceleration of time-consuming electromagnetic simulations, but also enables exploration into a hitherto unexplored design space and delivers stunning high-performance devices that run counter to the usual rules of thumb and human intuition.”

Wireless chips are a combination of standard electronic circuits like those in computer chips and electromagnetic structures including antennas, resonators, signal splitters, combiners and others. These combinations of elements are put together in every circuit block, carefully handcrafted and co-designed to operate optimally. This method is then scaled to other circuits, sub-systems and systems, making the design process extremely complex and time consuming, particularly for modern, high-performance chips behind applications like wireless communication, autonomous driving, radar and gesture recognition.

“Classical designs, carefully, put these circuits and electromagnetic elements together, piece by piece, so that the signal flows in the way we want it to flow in the chip. By changing those structures, we incorporate new properties,” Sengupta said. “Before, we had a finite way of doing this, but now the options are much larger.”

It can be hard to comprehend the vastness of a wireless chip’s design space. The circuitry in an advanced chip is so small, and the geometry so detailed, that the number of possible configurations for a chip exceeds the number of atoms in the universe, Sengupta said. There is no way for a person to understand that level of complexity, so human designers don’t try. They build chips from the bottom up, adding components as needed and adjusting the design as they build.

The AI approaches the challenge from a different perspective, Sengupta said. It views the chip as a single artifact. This can lead to strange, but effective arrangements. He said humans play a critical role in the AI system, in part because that AI can make faulty arrangements as well as efficient ones. It is possible for AI to hallucinate elements that don’t work, at least for now. This requires some level of human oversight.

“There are pitfalls that still require human designers to correct,” Sengupta said. “The point is not to replace human designers with tools. The point is to enhance productivity with new tools. The human mind is best utilized to create or invent new things, and the more mundane, utilitarian work can be offloaded to these tools.”

The researchers have used AI to discover and design complex electromagnetic structures that are-co-designed with circuits to create broadband amplifiers. Sengupta said future research will involve linking multiple structures and designing entire wireless chips with the AI system.

“Now that this has shown promise, there is a larger effort to think about more complicated systems and designs,” he said. “This is just the tip of the iceberg in terms of what the future holds for the field.”