A new study, led by UC San Francisco researchers, found that older, healthy volunteers, with lower concentrations of B12, but still in the normal range, showed signs of neurological and cognitive deficiency. These levels were associated with more damage to the brain’s white matter — the nerve fibers that enable communication between areas of the brain — and test scores associated with slower cognitive and visual processing speeds, compared to those with higher B12.

The study published in Annals of Neurology on Feb. 10.

The researchers led by senior author Ari J. Green, MD, of the UCSF Departments of Neurology and Ophthalmology and the Weill Institute for Neurosciences, said that the results raise questions about current B12 requirements and suggest the recommendations need updating.

“Previous studies that defined healthy amounts of B12 may have missed subtle functional manifestations of high or low levels that can affect people without causing overt symptoms,” said Green, noting that clear deficiencies of the vitamin are commonly associated with a type of anemia. “Revisiting the definition of B12 deficiency to incorporate functional biomarkers could lead to earlier intervention and prevention of cognitive decline.”

Lower B12 correlates with slower processing speeds, brain lesions

In the study, researchers enrolled 231 healthy participants without dementia or mild cognitive impairment, whose average age was 71. They were recruited through the Brain Aging Network for Cognitive Health (BrANCH) study at UCSF.

Their blood B12 amounts averaged 414.8 pmol/L, well above the U.S. minimum of 148 pmol/L. Adjusted for factors like age, sex, education and cardiovascular risks, researchers looked at the biologically active component of B12, which provides a more accurate measure of the amount of the vitamin that the body can utilize. In cognitive testing, participants with lower active B12 were found to have slower processing speed, relating to subtle cognitive decline. Its impact was amplified by older age. They also showed significant delays responding to visual stimuli, indicating slower visual processing speeds and general slower brain conductivity.

MRIs revealed a higher volume of lesions in the participants’ white matter, which may be associated with cognitive decline, dementia or stroke.

While the study volunteers were older adults, who may have a specific vulnerability to lower levels of B12, co-first author Alexandra Beaudry-Richard, MSc, said that these lower levels could “impact cognition to a greater extent than what we previously thought, and may affect a much larger proportion of the population than we realize.” Beaudry-Richard is currently completing her doctorate in research and medicine at the UCSF Department of Neurology and the Department of Microbiology and Immunology at the University of Ottawa.

“In addition to redefining B12 deficiency, clinicians should consider supplementation in older patients with neurological symptoms even if their levels are within normal limits,” she said. “Ultimately, we need to invest in more research about the underlying biology of B12 insufficiency, since it may be a preventable cause of cognitive decline.”

The experiments were designed to answer a question never before asked of wild fish: are they capable of telling people apart? Overall, little scientific evidence exists to show that fish can recognize humans at all. One captive-bred species, archerfish, was able to recognize computer-generated images of human faces in laboratory experiments. “But nobody has ever asked whether wild fish have the capacity, or indeed motivation, to recognize us when we enter their underwater world,” says Maëlan Tomasek, a doctoral student at MPI-AB and the University of Clermont Auvergne, France.

Now, a team from MPI-AB have asked; and the fish have responded. Wild fish can recognize individual humans. And, more than that, they follow specific divers they know will reward them. This finding, published in Biology Letters, lends credence to the possibility that fish can have differentiated relationships with specific humans.

The fish who volunteered

The research team conducted the study eight meters underwater at a research site in the Mediterranean Sea where populations of wild fish have become habituated to the presence of scientists. Their experiments took place in open water and fish participated in trials as “willing volunteers who could come and go as they pleased,” explains Katinka Soller, a bachelor student from MPI-AB who was co-first author on the study with Tomasek.

The first experimental phase — the training — tested if fish could learn to follow an individual diver. The training diver, Soller, started by trying to attract the attention of local fish; she wore a bright red vest and fed fish while swimming a length of 50 meters. Over time, Soller removed the conspicuous cues until she wore plain dive gear, kept the food hidden, and fed fish only after they had followed her the full 50 meters.

Of dozens of fish species inhabiting the marine station, two species of seabream in particular willingly engaged in the training sessions. Sea bream are best known to us as fish that we buy to eat, yet they surprised the scientists by their curiosity and willingness to learn.

“Once I entered the water, it was a matter of seconds before I would see them swimming towards me, seemingly coming out of nowhere,” says Soller. Not only were bream learning to follow her, but the same individuals were showing up day after day to join the lessons. Soller even took to giving them names: “There was Bernie with two shiny silver scales on the back and Alfie who had a nip out of the tail fin,” she says.

After 12 days of training, roughly 20 fish were reliably following Soller on training swims and she could recognize several of them from physical traits. By identifying individual fish participating in the experiment, the stage was set for the next experimental phase: testing if these same fish could tell Soller apart from another diver.

The two-diver test

This time Soller dived with Tomasek whose dive gear differed slightly from hers, notably in some colorful parts of the wetsuit and fins. Both divers started at the same point and then swam in different directions. On the first day, the fish followed both divers equally. “You could see them struggling to decide who to chase,” says Soller.

But Tomasek never fed the fish who followed him, so from the second day, the number of fish following Soller increased significantly. To confirm that fish were learning to recognize the correct diver, the researchers focused on six fish out of the large group to study individually, finding that four of these showed strong positive learning curves over the experiment. “This is a cool result because it shows that fish were not simply following Katinka out of habit or because other fish were there,” says Tomasek. “They were conscious of both divers, testing each one and learning that Katinka produced the reward at the end of the swim.”

But when Soller and Tomasek repeated the trials, this time wearing identical diving gear, the fish were unable to discriminate them. For the scientists, this was strong evidence that fish had associated the differences in the dive gear, most likely the colors, with each diver. “Almost all fish have color vision, so it is not surprising that the sea bream learned to associate the correct diver based on patches of color on the body,” says Tomasek.

Fish know how we look

Underwater, we do the same. “Faces are distorted by diving masks, so we usually rely on differences between wetsuits, fins, or other parts of the gear to recognize each other,” says Soller. With more time, the authors say, fish might have learned to pay attention to subtler human features, like hair or hands, to distinguish divers. “We already observed them approaching our faces and scrutinizing our bodies,” adds Soller. “It was like they were studying us, not the other way around.”

This study corroborates many anecdotal reports of animals, including fish, recognizing humans; but it goes further by performing dedicated experiments in completely natural contexts. Finding that wild fish can quickly learn to use specific cues to recognize individual human divers, it stands to reason that many other fish species, our pets included, can recognize certain patterns to identify us, the scientists say. This mechanism is the foundation for special interactions between individuals, even across species.

Senior author Alex Jordan, who leads a group at MPI-AB, says: “It doesn’t come a shock to me that these animals, which navigate a complex world and interact with myriad different species every minute, can recognize humans based on visual cues. I suppose the most surprising thing is that we would be surprised they can. It suggests we might underestimate the capacities of our underwater cousins.”

Adds Tomasek: “It might be strange to think about humans sharing a bond with an animal like a fish that sits so far from us on the evolutionary tree, that we don’t intuitively understand. But human-animal relationships can overcome millions of years of evolutionary distance if we bother to pay attention. Now we know that they see us, it’s time for us to see them.”

SACs are one of the most crucial catalysts. They play a pivotal role in enhancing efficiency in diverse applications including chemical industries, energy conversion, and environmental processes. For water purification in particular, SACs can overcome the limitations of traditional heterogeneous catalysts such as the kinetics, catalytic selectivity, and stability — paving a promising way for the advancement of efficient and sustainable water purification technologies.

However, the development of SACs frequently employs time-consuming trial-and-error methods, and the typical synthesis methods often lack a high level of control. To avoid a process that essentially involves taking shots in the dark, researchers took a data-driven approach where they rapidly and accurately predicted which SACs would have the best performance before even starting to make them. They compared 43 metals-N₄ structures comprising transition and main group metal elements using a hard-template method.

Following this strategy, they determined that the best candidate was a well-designed Fe-SAC with a high loading of Fe-pyridine-N4 sites (~3.83 wt%) and highly mesoporous structure. It successfully exhibited ultra-high decontamination performance (rate constant of 100.97 min^-1 g^-2).

“The optimized Fe-SAC can also continuously operate for 100 hours,” remarks Associate Professor Hao Li of WPI-AIMR, “To our knowledge, this represents one of the best performances of wastewater purification on Fenton-like catalysts — which are reagents used for water purification — reported so far.”

Density functional theory calculations revealed that the underlying mechanism was that the SAC reduced the energy barrier of the rate-determining step, which is intermediate O* formation. This resulted in the highly selective generation of singlet oxygen, which has been shown to break down pollutants to help purify water.

To make sure the data-driven prediction had accurately selected this “best” candidate, the research team looked at five other metals-N4 structures (i.e., Fe, Co, Ni, Cu, and Mn) with different theoretical activities. They confirmed that Fe-SAC truly exhibited the most excellent Fenton-like performance among the five selected SACs, agreeing well with the data-driven prediction.

The close integration of a data-driven method with a precise synthesis strategy provides a novel paradigm for the rapid development of high-performance catalysts for environmental fields, and other fields that involve sustainable energy and catalysis. Moving forward, they aim to develop an efficient and user-friendly workflow for the rapid and effective design of catalysts.

Those interested in incorporating the method into their own work can view the experimental data and computational structures in the Digital Catalysis Platform (DigCat): the largest experimental catalysis database reported to date, developed by the Hao Li Lab. The findings were also published in Angewandte Chemie International Edition on January 31, 2025.

The article processing charge (APC) was supported by the Tohoku University Support Program.

The Lancet Global Health Commission report details for the first time how future investment in strengthening medical oxygen systems could have a huge impact by saving millions of lives and improving pandemic preparedness.

Almost 400 million children and adults require medical oxygen every year. More than five billion people, 60 per cent of the world’s population, don’t have access to safe and affordable medical oxygen services.

The Commission, co-chaired by Makerere University in Uganda, the International Centre for Diarrheal Disease Research (icddr,b) in Bangladesh, Murdoch Children’s Research Institute (MCRI) in Australia, Karolinska Institute in Sweden and the Every Breath Counts Coalition in the US was launched in 2022 against the backdrop of the COVID-19 pandemic. The Commission was tasked with submitting actionable recommendations for governments, industry, global health agencies, donors and the healthcare workforce.

MCRI Dr Hamish Graham said the COVID-19 pandemic had put a spotlight on the longstanding global inequities in accessing medical oxygen.

“Oxygen is required at every level of the healthcare system for children and adults with a wide range of acute and chronic conditions,” he said. Previous efforts, including the major investments in response to the COVID-19 pandemic, largely focused on the delivery of equipment to produce more oxygen, neglecting the supporting systems and people required to ensure it was distributed, maintained, and used safely and effectively.”

Dr Graham said channelling investments into national oxygen plans and bolstering health systems, including wider use of pulse oximeters (a small device that measures how much oxygen is in the blood), would help solve the medical oxygen crisis.

“We urgently need to make high-quality, pulse oximeters more affordable and widely accessible,” he said. Pulse oximeters are available in 54 per cent of general and 83 per cent of tertiary hospitals in low- and middle-income countries, with frequent shortages and equipment breakdowns.

“Concerningly, in these countries the devices are performed for only 20 per cent of patients presenting to general hospitals and almost never for those at primary healthcare facilities. We see the greatest inequities in small and rural government health facilities and across Sub-Saharan Africa.”

Dr Graham said the importance of medical oxygen must also be recognised and integrated into broader national strategies and pandemic preparedness and response planning.

“Governments should bring together public and private sector partners with a stake in medical oxygen delivery, including health, education, industry, energy and transport to design a system and set up a governance structure that supports the new Global Oxygen Alliance (GO₂AL) and replenishing The Global Fund with a strong oxygen access mandate,” he said.

Key findings from the report published in The Lancet Global Health include:

• The global need for medical oxygen is high. Every year, 374 million children and adults need medical oxygen, including 364 million patients with acute medical and surgical conditions and nine million patients with long-term oxygen needs due to chronic obstructive pulmonary disease.
• Global access to oxygen is highly inequitable with huge gaps in coverage despite pandemic-related investments. Less than one in three people in low- and middle-income countries who need oxygen for acute medical or surgical conditions receives it.

• Costs to fill the oxygen gap are large but represent a highly cost-effective investment that will have wide reaching impacts. Closing the large acute medical and surgical oxygen access gap in low- and middle-income countries requires an additional $US6.8 billion annually.

• National Medical Oxygen Plans are essential to facilitate investment and effectively coordinate service delivery. Less than 30 countries have developed National Oxygen Plans to date but all governments are encouraged to have one by 2030.

• Oxygen systems must be designed to suit the context, include operational costs, and be affordable to all patients. There is no one-size-fits-all national medical oxygen system. Governments should define priorities and optimise their systems to suit local conditions.

• Pulse oximetry is the gateway to safe, quality, affordable oxygen care and needs to be integrated in clinical guidelines, education and all levels of the healthcare system. Pulse oximetry measures should be routinely assessed in patients at all levels of health care.

• A need for closer collaboration between the medical oxygen industry, national governments and global health agencies. Companies should adopt specific oxygen access targets and publish progress while global health agencies should regularly assess oxygen industry progress similar to how the pharmaceutical industry operates.

• Accurate and timely data on oxygen systems is essential for effective decision making and oxygen service access. New toolssuch as the 10 Oxygen Coverage Indicators and a national Access to Medical Oxygen Scorecard (ATMO₂S) would help governments to both plan their national oxygen systems and report progress implementing the WHO Oxygen Resolution.

The report comes after it was announced MCRI would partner with 12 countries in the Pacific and Southeast Asia under a $10 million initiative to improve child and adolescent health across the region.

The Australian Government has awarded MCRI a strategic grant as part of its Partnerships for a Healthy Region Initiative.

The three-year funding will be used to establish the ReALiSE program — the Regional Alliance for Learning in Systems for Equitable Child and Adolescent Health — which will strengthen resilience in public health systems and engage with youth leaders and local communities to improve the health of all young people.

While taste receptors are traditionally associated with the tongue and our ability to perceive flavors, recent studies have shown that these receptors exist in other parts of the body, where they likely play different roles. This new study is the first to identify specific “sweet taste” receptors, known as TAS1R2 and TAS1R3, on the surface of heart muscle cells. The work will be presented at the 69th Biophysical Society Annual Meeting, to be held February 15 — 19, 2025 in Los Angeles.

The new research found that these receptors are not just present on heart muscle, but also functional. When the researchers stimulated these receptors in both human and mouse heart cells using aspartame, a common artificial sweetener, they observed a significant increase in the force of heart muscle contraction and accelerated calcium handling — key processes for a healthy heartbeat.

“After you eat a meal, it’s been shown that your heart rate and blood pressure actually are increasing,” said Micah Yoder, a graduate student in the lab of Jonathan Kirk at Loyola University Chicago. “Previously, this was thought to be a neural axis that’s being signaled. But we’re proposing a more direct consequence, where we have a spike in our blood sugar after eating a meal, and that’s binding to these sweet taste receptors on the heart muscle cells, causing a difference in the heartbeat,” he added.

Intriguingly, the researchers also found that these receptors are more abundant in the hearts of patients with heart failure, suggesting a possible link to disease. Further investigation revealed that stimulating the receptors triggers a cascade of molecular events within the heart cells, involving key proteins that control calcium flow and muscle contraction.

“During heart failure, the heart is changing its energetic landscape and prioritizing glucose uptake and glucose usage. So, it’s possible that during this energetic change, the heart might need to change its nutrient sensing abilities to accommodate this switch,” Yoder explained.

Additionally, their research may explain why high consumption of artificially sweetened beverages is linked to arrhythmogenesis, or an irregular heartbeat. Not only are these sweet taste receptors particularly stimulated by artificial sweeteners like aspartame, Yoder noted, he found that overstimulation of these sweet taste receptors lead to a an increase in arrhythmic like behavior in the heart cells.

But further research is needed to fully understand the long-term effects of stimulating these receptors in the heart as well as how these receptors might be targeted to strengthen the heart in the case of heart failure.

Bearing sharp teeth and powerful jaw muscles, suggesting a strong bite, the newly-identified ‘Bastetodon’ was a leopard-sized “fearsome” mammal. It would have been at the top of all carnivores and the food chain when our own monkey-like ancestors were evolving.

Findings, published in the peer-reviewed Journal of Vertebrate Paleontology, detail how this ferocious creature would have likely preyed on primates, early hippos, early elephants, and hyraxes in the lush forest of Fayum, Egypt, which is now home to a desert.

Describing the discovery, palaeontologist and lead author Shorouq Al-Ashqar, from Mansoura University and the American University in Cairo, says: “For days, the team meticulously excavated layers of rock dating back around 30 million years.

“Just as we were about to conclude our work, a team member spotted something remarkable — a set of large teeth sticking out of the ground. His excited shout brought the team together, marking the beginning of an extraordinary discovery: a nearly complete skull of an ancient apex carnivore, a dream for any vertebrate paleontologist.”

Bastetodon belongs to a species in an extinct group of carnivorous mammals called hyaenodonts. Hyaenodonts evolved long before modern-day carnivores such as cats, dogs, and hyenas. These predators with hyena-like teeth hunted in African ecosystems after the extinction of the dinosaurs.

The team — who go under the title ‘Sallam Lab’ — named the specimenafter the cat-headed ancient Egyptian goddess Bastet, who symbolized protection, pleasure, and good health. The name acknowledges the region where the specimen was found, famous for its fossils and Ancient Egyptian artifacts. The name is also a nod to the short, cat-like snout and teeth of this fearsome, leopard-sized carnivore (“-odon” means “tooth”).

Its skull was unearthed on Sallam Lab’s expedition to the Fayum Depression, an area where digs reveal an important time window into about 15 million years of evolutionary history of mammals in Africa. This timespan not only captures the transition from the Eocene’s global warming to the Oligocene’s global cooling, but also reveals how these climate shifts played a crucial role in shaping ecosystems that we still see today.

Beyond just a new ancient creature discovery, the finding of Bastetodon has already allowed the research team to reevaluate a group of lion-sized hyaenodonts that was discovered in the rocks of the Fayum over 120 years ago. In their paper the team also construct the genus Sekhmetops to describe this century-old material and to honor Sekhmet, the lion-headed goddess of wrath and war in ancient Egyptian mythology (“-ops” means “face”). In 1904, Sekhmetops was placed within a European group of hyaenodonts. The team demonstrated Bastetodon and Sekhmetops both belonged to a group of hyaenodonts that actually originated in Africa. In ancient Egypt, Bastet was often associated with Sekhmet, making the two genera scientifically and symbolically connected.

The study demonstrates the relatives of Bastetodon and Sekhmetops spread from Africa in multiple waves, eventually making it to Asia, Europe, India, and North America. By 18 million years ago, some relatives of these hyaenodonts were among the largest mammalian meat-eaters to ever walk the planet.

However, cataclysmic changes in global climate and tectonic changes in Africa opened the continent to the relatives of modern cats, dogs, and hyenas. As environments and prey changed, the specialized, carnivorous hyaenodonts diminished in diversity, finally going extinct and leaving our primate relatives to face a new set of antagonists.

“The discovery of Bastetodon is a significant achievement in understanding the diversity and evolution of hyaenodonts and their global distribution,” Shorouq adds.

“We are eager to continue our research to unravel the intricate relationships between these ancient predators and their environments over time and across continents.”

Concluding, co-author Dr. Matt Borths, Curator of Fossils at the Duke Lemur Center Museum of Natural History at Duke University in Durham, North Carolina, says: “The Fayum is one of the most important fossil areas in Africa. Without it, we would know very little about the origins of African ecosystems and the evolution of African mammals like elephants, primates, and hyaenodonts. Paleontologists have been working in the Fayum for over a century, but the Sallam Lab demonstrated there is more to discover in this remarkable region.”