Enlarge/ The SARah-1 mission is seen on the launch pad in June 2022.
SpaceX
On the day before Christmas last year, a Falcon 9 rocket launched from California and put two spy satellites into low-Earth orbit for the armed forces of Germany, which are collectively called the Bundeswehr.
Initially, the mission appeared successful. The German satellite manufacturer, OHB, declared that the two satellites were “safely in orbit.” The addition of the two SARah satellites completed a next-generation constellation of three reconnaissance satellites, the company said.
However, six months later, the two satellites have yet to become operational. According to the German publication Der Spiegel, the antennas on the satellites cannot be unfolded. Engineers with OHB have tried to resolve the issue by resetting the flight software, performing maneuvers to vibrate or shake the antennas loose, and more to no avail.
As a result, last week, German lawmakers were informed that the two new satellites will probably not go into operation as planned.
Saving SARah
The three-satellite constellation known as SARah—the SAR is a reference to the synthetic aperture radar capability of the satellites—was ordered in 2013 at a cost of $800 million. The first of the three satellites, SARah 1, launched in June 2022 on a Falcon 9 rocket. This satellite was built by Airbus in southern Germany, and it has since gone into operation without any problems.
The two smaller satellites built by OHB, flying with passive synthetic aperture radar reflectors, were intended to complement the SARah 1 satellite, which carries an active phased-array radar antenna.
“The new SARah satellites ensure that the Bundeswehr has the capability for worldwide imaging reconnaissance independent of the time of day or the weather,” the German military said at the time of the SARah 1 satellite launch. “At the same time, they provide support in the early detection and management of crises.”
This new constellation was intended to replace an aging fleet of similar, though less capable, satellites known as SAR-Lupe. This five-satellite constellation launched nearly two decades ago.
OHB said to be at fault
According to the Der Spiegel report, the Bundeswehr says the two SARah satellites built by OHB remain the property of the German company and would only be turned over to the military once they were operational. As a result, the military says OHB will be responsible for building two replacement satellites.
Shockingly, the German publication says that its sources indicated OHB did not fully test the functionality and deployment of the satellite antennas on the ground. This could not be confirmed.
This setback comes as OHB is attempting to complete a deal to go private—the investment firm KKR is planning to acquire the German space company. OHB officials said they initiated the effort to go private late last year because public markets had “structurally undervalued” the company.
OHB has its hands in many different space businesses in Europe. The small launch firm Rocket Factory Augsburg was spun out of OHB in 2018 and is working toward its debut launch later this year or in 2025. The company is also a supplier for the larger Ariane 6 rocket and one of several private companies that is part of a coalition bidding to build a Starlink-like satellite constellation for the European Union known as IRIS2.
Enlarge/ The Baishiya Karst Cave, where the recently analyzed samples were obtained.
Dongju Zhang’s group (Lanzhou University)
For well over a century, we had the opportunity to study Neanderthals—their bones, the items they left behind, their distribution across Eurasia. So, when we finally obtained the sequence of their genome and discovered that we share a genetic legacy with them, it was easy to place the discoveries into context. In contrast, we had no idea Denisovans existed when sequencing DNA from a small finger bone revealed that yet another relative of modern humans had roamed Asia in the recent past.
Since then, we’ve learned little more. The frequency of their DNA in modern human populations suggest that they were likely concentrated in East Asia. But we’ve only discovered fragments of bone and a few teeth since then, so we can’t even make very informed guesses as to what they might have looked like. On Wednesday, an international group of researchers described finds from a cave on the Tibetan Plateau that had been occupied by Denisovans, which tell us a bit more about these relatives: what they ate. And that appears to be anything they could get their hands on.
The Baishiya Karst Cave
The finds come from a site called the Baishiya Karst Cave, which is perched on a cliff on the northeast of the Tibetan Plateau. It’s located at a high altitude (over 3,000 meters or nearly 11,000 feet) but borders a high open plain, as you can see in the picture below.
Oddly, it came to the attention of the paleontology community because the cave was a pilgrimage site for Tibetan monks, one of whom discovered a portion of a lower jaw that eventually was given to a university. There, people struggled to understand exactly how it fit with human populations until eventually analysis of proteins preserved within it indicated it belonged to a Denisovan. Now called the Xiahe mandible, it remains the most substantial Denisovan fossil we’ve discovered to date.
Enlarge/ The Ganjia Basin borders the cliffs that contain the Baishiya Karst Cave.
Dongju Zhang’s group (Lanzhou University)
Since then, excavations at the site had turned up a large collection of animal bones, but none that had been identified as Denisovan. Sequencing of environmental DNA preserved in the cave, however, revealed that the Denisovans had occupied the cave regularly for at least 100,000 years, meaning they were surviving at altitude during both of the last two glacial cycles.
The new work focuses in on the bones, many of which are too fragmentary to be definitively assigned to a species. To do so, the researchers purified fragments of proteins from the bones, which contain large amounts of collagen. These fragments were then separated according to their mass, a technique called mass spectrometry, which works well even with the incredibly small volumes of proteins that survive over hundreds of thousands of years.
Mass spectrometry relies on the fact that there are only a limited number of combinations of amino acids—often only one—that will produce a protein fragment of a given mass. So, if the mass spectrometry finds a signal at that mass, you can compare the possible amino acid combinations that produce it to known collagen sequences to find matches. Some of these matches will end up being in places where collagens from different species have distinct sequences of amino acids, allowing you to determine what species the bone came from.
When used this way, the technique is termed zooarchaeology by mass spectrometry, or ZooMS. And, in the case of the work described in the new paper, it identified nearly 80 percent of the bone fragments that were tested.
Outside a 100-year-old house on the edge of the Peak District in northern England, a heat pump’s fan blades are swiftly spinning. They’re drawing outdoor air over coils of refrigerant, harvesting warmth from that air. All air-source heat pumps do this—and they can glean heat even on cold days. But this heat pump is special. It is one of the most efficient installations of its kind in the country.
“I’m number two on there,” fizzes owner Rob Ritchie, a retired chemistry teacher, referring to the system’s position on HeatPumpMonitor.org, a kind of online leaderboard for heat pumps around the UK and beyond. “I should say it isn’t important—but it is. It’s nice being there.”
At the time of writing, real-time data suggests that for every kilowatt-hour of electricity Ritchie’s heat pump consumes, it delivers 5.5 kilowatt-hours of heat—a coefficient of performance, or COP, of 5.5. Achieving a COP of 5 or above is “absolutely incredible,” says Emma-Louise Bennett, active transition support lead at Viessmann, the company that made Ritchie’s heat pump. In the UK, average heat pump COPs tend to be between 2 and 3.
For social-media-savvy plumbers and environmentally conscious home renovators who are increasingly sharing videos of their heating systems online, heat pumps are in vogue. In the race to decarbonize and curtail the devastating effects of climate change, switching home heating systems away from fossil-fuel-burning boilers and furnaces is essential. Heat pumps will be a key weapon in that fight, says the International Energy Agency. It estimates that, globally, heat pumps could reduce CO2 emissions by 500 million metric tons—equivalent to taking every car in Europe off the road.
A new generation of heating engineers has realized that they can push heat pumps to the limit. These installers are reaching astounding levels of efficiency by taking extra care to design low-temperature heating systems that warm rooms without using excess energy.
Heat pumps can offer multiple kilowatt-hours of heat per kilowatt-hour of electricity, thanks to physics. The refrigerant sealed inside the device evaporates readily when it is warmed even slightly, say by the outdoor air, and a compressor then pressurizes the warmed gas, which has the effect of heating it further. It only takes a little electricity to power this process, which can raise the refrigerant’s temperature by many degrees Celsius.
Since moving to his detached house near Sheffield about 10 years ago, Ritchie has installed loft insulation and solar panels, but the fabric of the building is not necessarily ideal for keeping the place toasty in an efficient way. The property has thin-cavity walls without much insulation in them, and Ritchie lives at 800 feet above sea level, meaning outdoor temperatures are generally relatively low. Thanks to his heat pump and solar panels, though, he estimates he’s now saving 2,700 pounds ($3,420) on his utility bills annually. It goes to show that heat pumps can work well in older properties in challenging locations, he says.
The system was designed by local installer Damon Blakemore, who also checks HeatPumpMonitor.org regularly to see how his work stands up against that of his competitors. Ritchie’s heat pump is not quite in pole position at present, but it is noteworthy, emphasizes Blakemore, because once a year’s worth of data has accumulated this September, it could be the first air-source device on the leaderboard to achieve a 365-day seasonal COP, or SCOP, of 5. This is an average that reveals how well a heat pump has performed over an entire year. Weather changes between summer and winter, which shift demand for heating, tend to affect overall system efficiency, among other factors.
Blakemore is one of the “SCOP-chasers,” as Bennett puts it, driven to maximize the efficiency of the systems he installs. There is a small but highly visible group of such people in the UK who follow each other on Facebook and X, drop in on each other’s podcasts, and jostle for high rankings on HeatPumpMonitor.org. Among the stakeholders in this race for efficiency is Heat Geek, an organization that has trained multiple high-performing installers—including Blakemore.
“It’s not really something we particularly anticipated,” says Glyn Hudson, cofounder of Open Energy Monitor (OEM), which runs HeatPumpMonitor.org, referring to the casual competition emerging in the heating industry. “But installers are proud of their work. They do enjoy showing off photos of their installations on social media. The pipework layout is very important to them.”
Enlarge/ Tops of citrus sodas at a manufacturing plant.
After more than five decades of limbo, the Food and Drug Administration on Wednesday revoked the authorization of brominated vegetable oil (BVO) in food, banning an additive long known to have toxic effects that is already banned in Europe, Japan, Australia, New Zealand, and California.
BVO—simply vegetable oil that is modified with bromine—has been used in foods since the 1920s. It has often been used as a stabilizer for fruit flavorings, particularly in citrusy beverages, including sodas, to keep the citrus flavoring from separating and floating to the top. The FDA authorized the use of BVO just after gaining the authority to regulate food additives in 1958. By the early 1960s, the FDA had put BVO on its first inventory of food additives it deemed generally safe—designated “generally recognized as safe” or GRAS. But safety concerns quickly surfaced, and by the late 1960s, the FDA had already limited its use to a flavoring stabilizer and capped the amount that could be used to 15 parts per million.
That 15-ppm limit was authorized on an “interim basis,” pending more safety studies. In 1970, the FDA revoked the GRAS designation for BVO, but continued to allow the 15-ppm limit—on an interim basis—given that safety studies “did not indicate an immediate health threat from the limited use.”
“Disgraceful”
The interim safety limit stayed in place until now, as the FDA was waiting for more safety data. In the mid-2010s, following bans in Europe and Japan, the agency began to review BVO and commissioned its own studies. A resulting rat study, which the agency published in 2022, found that when rats were fed BVO at levels that mimicked humans’ exposure at the 15-ppm limit, the animals developed abnormalities in their thyroids, alterations in their hormone signaling, and accumulation of brominated fatty acids in their hearts, livers, and fat.
By then, most major soda makers had already phased BVO out of their citrusy sodas and other drinks amid public pressure. Coca-Cola pledged to remove BVO from its drinks in 2014, and PepsiCo confirmed in 2020 that it had removed it from its drinks, including Mountain Dew and Gatorade. The FDA reports that only a few beverages in the US still use the additive. Among the lingering users is Sun Drop, according to its product page.
Manufacturers have one year to reformulate their products, the FDA notes.
Consumer advocates chided the FDA while celebrating the ban. “The FDA’s decision to ban brominated vegetable oil in food is a victory for public health,” Scott Faber, senior vice president of government affairs at the Environmental Working Group, said in a statement. “But it’s disgraceful that it took decades of regulatory inaction to protect consumers from this dangerous chemical.”
Enlarge/ Artist’s illustration of the COSI spacecraft.
A small research satellite designed to study the violent processes behind the creation and destruction of chemical elements will launch on a SpaceX Falcon 9 rocket in 2027, NASA announced Tuesday.
The Compton Spectrometer and Imager (COSI) mission features a gamma-ray telescope that will scan the sky to study gamma-rays emitted by the explosions of massive stars and the end of their lives. These supernova explosions generate reactions that fuse new atomic nuclei, a process called nucleosynthesis, of heavier elements.
Using data from COSI, scientists will map where these elements are forming in the Milky Way galaxy. COSI’s observations will also yield new insights into the annihilation of positrons, the antimatter equivalent of electrons, which appear to be originating from the center of the galaxy. Another goal for COSI will be to rapidly report the location of short gamma-ray bursts, unimaginably violent explosions that flash and then fade in just a couple of seconds. These bursts are likely caused by merging neutron stars.
The COSI mission will be sensitive to so-called soft gamma rays, a relatively unexplored segment of the electromagnetic spectrum. The telescope is based on a design scientists have flown on research balloon flights.
NASA selected COSI in a competition for funding to become the next mission in the agency’s Explorers program in 2021. Earlier this year, NASA formally approved the mission to proceed into development for launch in August 2027, with an overall budget in the range of $267 million to $294 million, according to NASA budget documents.
From Florida to the equator
COSI is a relatively small spacecraft, built by Northrop Grumman and weighing less than a ton, but it will ride alone into orbit on top of a Falcon 9 rocket. That’s because COSI will operate in an unusual orbit about 340 miles (550 kilometers) over the equator, an orbit chosen to avoid interference from radiation over the South Atlantic Anomaly, the region where the inner Van Allen radiation belt comes closest to Earth’s surface.
SpaceX’s Falcon 9 will deliver COSI directly into its operational orbit after taking off from Cape Canaveral, Florida, then will fire its upper stage in a sideways maneuver to make a turn at the equator. This type of maneuver, called a plane change, takes a lot of energy, or delta-V, on par with the delta-V required to put a heavier satellite into a much higher orbit.
Enlarge/ File photo of a Falcon 9 launch on May 6 from Cape Canaveral Space Force Station, Florida.
SpaceX
NASA awarded SpaceX a firm-fixed-price contract valued at $69 million to launch the COSI mission. This is about a 37 percent increase in the price NASA paid SpaceX in a 2019 contract for launch of the similarly sized IXPE X-ray telescope into a similar orbit as COSI. The higher price is at least partially explained by inflation.
The space agency didn’t have much of a decision to make in the COSI launch contract. The Falcon 9 is the only rocket certified by NASA that can launch a satellite with the mass of COSI into its equatorial orbit.
In the next couple of years, NASA hopes United Launch Alliance’s Vulcan rocket and Blue Origin’s New Glenn launcher will be in the mix to compete for launch contracts for missions like COSI. All of ULA’s remaining Atlas V rockets are already booked by other customers.
Because most things about Earth change so slowly, it’s difficult to imagine them being any different in the past. But Earth’s rotation has been slowing due to tidal interactions with the Moon, meaning that days were considerably shorter in the past. It’s easy to think that a 22-hour day wouldn’t be all that different, but that turns out not to be entirely true.
For example, some modeling has indicated that certain day lengths will be in resonance with other effects caused by the planet’s rotation, which can potentially offset the drag caused by the tides. Now, a new paper looks at how these resonances could affect the climate. The results suggest that it would shift rain to occurring in the morning and evening while leaving midday skies largely cloud-free. The resulting Earth would be considerably warmer.
On the Lamb
We’re all pretty familiar with the fact that the daytime Sun warms up the air. And those of us who remember high school chemistry will recall that a gas that is warmed will expand. So, it shouldn’t be a surprise to hear that the Earth’s atmosphere expands due to warming on its day side and contracts back again as it cools (these lag the daytime peak in sunlight). These differences provide something a bit like a handle that the gravitational pulls of the Sun and Moon can grab onto, exerting additional forces on the atmosphere. This complicated network of forces churns our atmosphere, helping shape the planet’s weather.
Two researchers, Russell Deitrick and Colin Goldblatt at Canada’s University of Victoria, were curious as to what would happen to these forces as the day length got shorter. Specifically, they were interested in a period where the day’s length would be at resonance with phenomena called Lamb waves.
Lamb waves aren’t specific to the atmosphere. Rather, they’re a specific manner in which a disturbance can travel through a medium, from vibrations in a solid to sound through the air.
Although various forces can create Lamb waves in the atmosphere, they’ll travel with a set of characteristic frequencies. One of those is roughly 10.5 to 11 hours. As you go back in time to shorter days, you’ll reach a point where the Earth’s day was a bit shorter than 22 hours, or twice the period of the Lamb waves. At this point, any disturbances in the atmosphere related to day length would have the ability to interact with the Lamb waves that were set off the day prior. This resonance could potentially strengthen the impact of any atmospheric phenomena related to day length.
Figuring out whether they do turned out to be a bit of a challenge. There are plenty of climate models to let researchers explore what’s going on in the modern atmosphere. But a lot of these have key features, like day length and solar output, hard coded into them. Others don’t let you do things like rearrange the Earth’s continents or change some atmospheric components.
The researchers did find a model that would allow them to change day length, solar intensity, and carbon dioxide concentrations to those present when Earth’s day length was 22 hours (which was likely to be in the pre-Cambrian). But it wasn’t able to reset the ozone concentrations, and ozone is also a greenhouse gas. So, they ran simulations without ozone, which are expected to be an under-estimate, and one where they elevated methane concentrations in order to mimic ozone’s greenhouse effect.
The US government will pay Moderna $176 million to develop an mRNA vaccine against a pandemic influenza—an award given as the highly pathogenic bird flu virus H5N1 continues to spread widely among US dairy cattle.
The funding flows through BARDA, the Biomedical Advanced Research and Development Authority, as part of a new Rapid Response Partnership Vehicle (RRPV) Consortium. The program is intended to set up partnerships with industry to help the country better prepare for pandemic threats and develop medical countermeasures, the Department of Health and Human Services said in a press announcement Tuesday.
In an announcement of its own Tuesday, Moderna noted that it began a Phase 1/2 trial of a pandemic influenza virus vaccine last year, which included versions targeting H5 and H7 varieties of bird flu viruses. The company said it expects to release the results of that trial this year and that those results will direct the design of a Phase 3 trial, anticipated to begin in 2025.
The funding deal will support late-stage development of a “pre-pandemic vaccine against H5 influenza virus,” Moderna said. But, the deal also includes options for additional vaccine development in case other public health threats arise.
“mRNA vaccine technology offers advantages in efficacy, speed of development, and production scalability and reliability in addressing infectious disease outbreaks, as demonstrated during the COVID-19 pandemic,” Moderna CEO Stéphane Bancel said in the announcement. “We are pleased to continue our collaboration with BARDA to expedite our development efforts for mRNA-based pandemic influenza vaccines and support the global public health community in preparedness against potential outbreaks.”
US health officials have said previously that they were in talks with Moderna and Pfizer about the development of a pandemic bird flu vaccine. The future vaccine will be in addition to standard protein-based bird flu vaccines that are already developed. In recent weeks, the health department has said it is working to manufacture 4.8 million vials of H5 influenza vaccine in the coming months. The plans come three months into the H5N1 dairy outbreak, which is very far from the initial hopes of containment.
Botched response
The US is badly fumbling its response to the unprecedented outbreak, drawing criticism from US-based and international experts alike. Genetic analyses suggest that the virus has been spreading among the country’s dairy cattle since late last year. But, it wasn’t until months later, on March 25, that the US Department of Agriculture confirmed the first four infected herds in two states (Texas and Kansas). Since then, the outbreak has spread to around 140 herds in 12 states—at least.
Some farms are refusing to test, and experts expect that there is a significant number of undocumented herd infections, particularly given the widespread detection of inactivated H5N1 in the commercial milk supply. Further, of the 140 herds with documented infections, federal officials do not know how many are still actively infected rather than recovered. It is unclear if infected cows can become reinfected, and if so, how quickly after an infection.
While the risk to the general public is considered to be low currently, farm workers are at higher risk of contracting the infection. To date, there have been three confirmed infections among dairy farm workers—one in Texas and two in Michigan, which has had a uniquely robust response to the outbreak. Still, with hundreds to thousands of farm workers at risk of contracting the virus, only 53 people in the country to date have been tested for H5 influenza.
In a presentation in London last month, global health leader Seth Berkley said it was “shocking to watch the ineptitude” of the US response to the H5N1 outbreak. He, like other experts, questioned whether the US public health community has learned or improved from the failures of the COVID-19 pandemic.
Similar to problems during the pandemic, a key barrier to the H5N1 response is resistance from farmers and farm workers to partner with state and federal health officials. Federal agencies have limited authority within states, but they have announced an array of assistance programs for dairy farms, including compensatory funding and access to personal protective equipment for farm workers. They have also issued guidance and restrictions to tighten biosecurity measures. But there has been little voluntary participation on both fronts.
For instance, officials figured out early in the outbreak that movement of cattle, workers, and equipment between farms is the main way H5N1 is spreading among dairies. In April, the USDA required testing of a portion of cows prior to their movement across state lines. But movement within states is governed by states. In a survey last month, which captured data from 54 percent of affected farms at the time, more than 60 percent of farmers said they continued to move cattle off their infected farms after the onset of clinical signs of infection in their animals.
The more the virus expands its footprint across US dairy farms, adapts to its newfound mammalian host, and comes in contact with humans, the more and more chances it has to leap to humans and gain the ability to spread among us.
In HHS’s Tuesday announcement of the Moderna award, Dawn O’Connell, assistant secretary for Preparedness and Response, spoke to the growing concern that the H5N1 outbreak could spark another pandemic. “The award made today is part of our longstanding commitment to strengthen our preparedness for pandemic influenza,” O’Connell said. “Adding this technology to our pandemic flu toolkit enhances our ability to be nimble and quick against the circulating strains and their potential variants.”
Enlarge/ Scientists have observed wound care and selective amputation in Florida carpenter ants.
Florida carpenter ants (Camponotus floridanus) selectively treat the wounded limbs of their fellow ants, according to a new paper published in the journal Current Biology. Depending on the location of the injury, the ants either lick the wounds to clean them or chew off the affected limb to keep infection from spreading. The treatment is surprisingly effective, with survival rates of around 90–95 percent for amputee ants.
“When we’re talking about amputation behavior, this is literally the only case in which a sophisticated and systematic amputation of an individual by another member of its species occurs in the animal kingdom,” said co-author Erik Frank, a behavioral ecologist at the University of Würzburg in Germany. “The fact that the ants are able to diagnose a wound, see if it’s infected or sterile, and treat it accordingly over long periods of time by other individuals—the only medical system that can rival that would be the human one.”
Frank has been studying various species of ants for many years. Late last year, he co-authored a paper detailing how Matabele ants (Megaponera analis) south of the Sahara can tell if an injured comrade’s wound is infected or not, thanks to chemical changes in the hydrocarbon profile of the ant cuticle when a wound gets infected. These ants only eat termites, but termites have powerful jaws and use them to defend against predators, so there is a high risk of injury to hunting ants.
If an infected wound is identified, the ants then treat said wound with antibiotics produced by a special gland on the side of the thorax (the metapleural gland). Those secretions are made of some 112 components, half of which have antimicrobial properties. Frank et al.’s experiments showed that applying these secretions reduced the mortality rate of injured ants by 90 percent, and future research could lead to the discovery of new antibiotics suitable for treating humans. (This work was featured in an episode of a recent Netflix nature documentary, Life on Our Planet.)
Amputation in Camponotus maculatus. Credit: Danny Buffat.
Those findings caused Frank to ponder if the Matabele ant is unique in its ability to detect and treat infected wounds, so he turned his attention to the Florida carpenter ant. These reddish-brown ants nest in rotting wood and can be fiercely territorial, defending their homes from rival ant colonies. That combat comes with a high risk of injury. Florida carpenter ants lack a metapleural gland, however, so Frank et al. wondered how this species treats injured comrades. They conducted a series of experiments to find out.
Frank et al. drew their subjects from colonies of lab-raised ants (produced by queens collected during 2017 fieldwork in Florida), and ants targeted for injury were color-tagged with acrylic paint two days before each experiment. Selective injuries to tiny (ankle-like) tibias and femurs (thighs) were made with sterile Dowel-scissors, and cultivated strains of P. aeruginosa were used to infect some of those wounds, while others were left uninfected as a control. The team captured the subsequent treatment behavior of the other ants on video and subsequently analyzed that footage. They also took CT scans of the ants’ legs to learn more about the anatomical structure.
Hoau-Yan Wang, 67, a medical professor at the City University of New York, was a paid collaborator with the Austin, Texas-based pharmaceutical company Cassava Sciences. Wang’s research and publications provided scientific underpinnings for Cassava’s Alzheimer’s treatment, Simufilam, which is now in Phase III trials.
Simufilam is a small-molecule drug that Cassava claims can restore the structure and function of a scaffolding protein in the brain of people with Alzheimer’s, leading to slowed cognitive decline. But outside researchers have long expressed doubts and concerns about the research.
In 2023, Science magazine obtained a 50-page report from an internal investigation at CUNY that looked into 31 misconduct allegations made against Wang in 2021. According to the report, the investigating committee “found evidence highly suggestive of deliberate scientific misconduct by Wang for 14 of the 31 allegations,” the report states. The allegations largely centered around doctored and fabricated images from Western blotting, an analytical technique used to separate and detect proteins. However, the committee couldn’t conclusively prove the images were falsified “due to the failure of Dr. Wang to provide underlying, original data or research records and the low quality of the published images that had to be examined in their place.”
In all, the investigation “revealed long-standing and egregious misconduct in data management and record keeping by Dr. Wang,” and concluded that “the integrity of Dr. Wang’s work remains highly questionable.” The committee also concluded that Cassava’s lead scientist on its Alzheimer’s disease program, Lindsay Burns, who was a frequent co-author with Wang, also likely bears some responsibility for the misconduct.
In March 2022, five of Wang’s articles published in the journal PLOS One were retracted over integrity concerns with images in the papers. Other papers by Wang have also been retracted or had statements of concern attached to them. Further, in September 2022, the Food and Drug Administration conducted an inspection of the analytical work and techniques used by Wang to analyze blood and cerebrospinal fluid from patients in a simufilam trial. The investigation found a slew of egregious problems, which were laid out in a “damning” report obtained by Science.
In the indictment last week, federal authorities were explicit about the allegations, claiming that Wang falsified the results of his scientific research to NIH “by, among other things, manipulating data and images of Western blots to artificially add bands [which represent proteins], subtract bands, and change their relative thickness and/or darkness, and then drawing conclusions” based on those false results.
Wang is charged with one count of major fraud against the United States, two counts of wire fraud, and one count of false statements. If convicted, he faces a maximum penalty of 10 years in prison for the major fraud charge, 20 years in prison for each count of wire fraud, and five years in prison for the count of false statements, the Department of Justice said in an announcement.
In a statement posted to its website, Cassava acknowledged Wang’s indictment, calling him a “former” scientific adviser. The company also said that the grants central to the indictment were “related to the early development phases of the Company’s drug candidate and diagnostic test and how these were intended to work.” However, Cassava said that Wang “had no involvement in the Company’s Phase 3 clinical trials of simufilam.”
Those ongoing trials, which some have called to be halted, are estimated to include over 1,800 patients across several countries.
Enlarge/ Right now, the software doesn’t do arms, so don’t go taking on any aliens with it.
20th Century Fox
Exoskeletons today look like something straight out of sci-fi. But the reality is they are nowhere near as robust as their fictional counterparts. They’re quite wobbly, and it takes long hours of handcrafting software policies, which regulate how they work—a process that has to be repeated for each individual user.
To bring the technology a bit closer to Avatar’s Skel Suits or Warhammer 40k power armor, a team at North Carolina University’s Lab of Biomechatronics and Intelligent Robotics used AI to build the first one-size-fits-all exoskeleton that supports walking, running, and stair-climbing. Critically, its software adapts itself to new users with no need for any user-specific adjustments. “You just wear it and it works,” says Hao Su, an associate professor and co-author of the study.
Tailor-made robots
An exoskeleton is a robot you wear to aid your movements—it makes walking, running, and other activities less taxing, the same way an e-bike adds extra watts on top of those you generate yourself, making pedaling easier. “The problem is, exoskeletons have a hard time understanding human intentions, whether you want to run or walk or climb stairs. It’s solved with locomotion recognition: systems that recognize human locomotion intentions,” says Su.
Building those locomotion recognition systems currently relies on elaborate policies that define what actuators in an exoskeleton need to do in each possible scenario. “Let’s take walking. The current state of the art is we put the exoskeleton on you and you walk on a treadmill for an hour. Based on that, we try to adjust its operation to your individual set of movements,” Su explains.
Building handcrafted control policies and doing long human trials for each user makes exoskeletons super expensive, with prices reaching $200,000 or more. So, Su’s team used AI to automatically generate control policies and eliminate human training. “I think within two or three years, exoskeletons priced between $2,000 and $5,000 will be absolutely doable,” Su claims.
His team hopes these savings will come from developing the exoskeleton control policy using a digital model, rather than living, breathing humans.
Digitizing robo-aided humans
Su’s team started by building digital models of a human musculoskeletal system and an exoskeleton robot. Then they used multiple neural networks that operated each component. One was running the digitized model of a human skeleton, moved by simplified muscles. The second neural network was running the exoskeleton model. Finally, the third neural net was responsible for imitating motion—basically predicting how a human model would move wearing the exoskeleton and how the two would interact with each other. “We trained all three neural networks simultaneously to minimize muscle activity,” says Su.
One problem the team faced is that exoskeleton studies typically use a performance metric based on metabolic rate reduction. “Humans, though, are incredibly complex, and it is very hard to build a model with enough fidelity to accurately simulate metabolism,” Su explains. Luckily, according to the team, reducing muscle activations is rather tightly correlated with metabolic rate reduction, so it kept the digital model’s complexity within reasonable limits. The training of the entire human-exoskeleton system with all three neural networks took roughly eight hours on a single RTX 3090 GPU. And the results were record-breaking.
Bridging the sim-to-real gap
After developing the controllers for the digital exoskeleton model, which were developed by the neural networks in simulation, Su’s team simply copy-pasted the control policy to a real controller running a real exoskeleton. Then, they tested how an exoskeleton trained this way would work with 20 different participants. The averaged metabolic rate reduction in walking was over 24 percent, over 13 percent in running, and 15.4 percent in stair climbing—all record numbers, meaning their exoskeleton beat every other exoskeleton ever made in each category.
This was achieved without needing any tweaks to fit it to individual gaits. But the neural networks’ magic didn’t end there.
“The problem with traditional, handcrafted policies was that it was just telling it ‘if walking is detected do one thing; if walking faster is detected do another thing.’ These were [a mix of] finite state machines and switch controllers. We introduced end-to-end continuous control,” says Su. What this continuous control meant was that the exoskeleton could follow the human body as it made smooth transitions between different activities—from walking to running, from running to climbing stairs, etc. There was no abrupt mode switching.
“In terms of software, I think everyone will be using this neural network-based approach soon,” Su claims. To improve the exoskeletons in the future, his team wants to make them quieter, lighter, and more comfortable.
But the plan is also to make them work for people who need them the most. “The limitation now is that we tested these exoskeletons with able-bodied participants, not people with gait impairments. So, what we want to do is something they did in another exoskeleton study at Stanford University. We would take a one-minute video of you walking, and based on that, we would build a model to individualize our general model. This should work well for people with impairments like knee arthritis,” Su claims.
Enlarge/ Extreme sportsman Ross Edgley comes face to face with a great hammerhead shark in the waters of Bimini in the Bahamas.
National Geographic/Nathalie Miles
Ultra-athlete Ross Edgley is no stranger to pushing his body to extremes. He once ran a marathon while pulling a one-ton car; ran a triathlon while carrying a 100-pound tree; and climbed a 65-foot rope over and over again until he’d climbed the equivalent of Mt. Everest—all for charity. In 2016, he set the world record for the world’s longest staged sea swim around the coastline of Great Britain: 1780 miles over 157 days.
At one point during that swim, a basking shark appeared and swam alongside Edgley for a day and a half. That experience ignited his curiosity about sharks and eventually led to his new National Geographic documentary, Shark vs. Ross Edgley—part of four full weeks of 2024 SHARKFEST programming. Edgley matches his athletic prowess against four different species of shark. He tries to jump out of the water (polaris) like a great white shark; withstand the G forces produced by a hammerhead shark‘s fast, rapid turns; mimic the extreme fasting and feasting regimen of a migrating tiger shark; and match the swimming speed of a mako shark.
“I love this idea of having a goal and then reverse engineering and deconstructing it,” Edgley told Ars. “[Sharks are] the ultimate ocean athletes. We just had this idea: what if you’re crazy enough to try and follow in the footsteps of four amazing sharks? It’s an impossible task. You’re going to fail, you’re going to be humbled. But in the process, we could use it as a sports/shark science experiment, almost like a Trojan horse to bring science and ocean conservation to a new audience.”
And who better than Edgley to take on that impossible challenge? “The enthusiasm he brings to everything is really infectious,” marine biologist and shark expert Mike Heithaus of Florida International University told Ars. “He’s game to try anything. He’d never been in the water with sharks and we’re throwing him straight in with big tiger sharks and hammerheads. He’s loving the whole thing and just devoured all the information.”
That Edgley physique doesn’t maintain itself, so the athlete was up at 4 AM swimming laps and working out every morning before the rest of the crew had their coffee. “I’m doing bicep curls with my coffee cup and he’s doing bicep curls with the 60-pound underwater camera,” Heithaus recalled. “For the record, I got one rep in and I’m very proud of that.” Score one for the shark expert.
(Spoilers below for the various shark challenges.)
Ross vs. the great white shark
Ross Edgley gets some tips on how to power (polaris) his body out of the water like a white shark from synchronized swimmer Samantha Wilson
National Geographic/Nathalie Miles
The Aquabatix synchronized swim team demonstrates the human equivalent to a white shark’s polaris.
National Geographic/Nathalie Miles
Edgley tries out a mono fin to improve his polaris performance.
National Geographic/Nathalie Miles
Edgley propelling 3/4 of his body out of the pool to mimic a white shark’s polaris movement
National Geographic/Bobby Cross
For the first challenge, Edgley took on the great white shark, a creature he describes as a “submarine with teeth.” These sharks are ambush hunters, capable of propelling their massive bodies fully out of the water in an arching leap. That maneuver is called a polaris, and it’s essential to the great white shark’s survival. It helps that the shark has 65 percent muscle mass, particularly concentrated in the tail, as well as a light skeleton and a large liver that serves as buoyancy device.
Edgley, by comparison, is roughly 45 percent muscle mass—much higher than the average human but falling short of the great white shark. To help him try to match the great white’s powerful polaris maneuver, Edgley sought tips on biomechanics from the Aquabatix synchronized swim team, since synchronized swimmers must frequently launch their bodies fully out of the water during routines. They typically get a boost from their teammates to do so.
The team did manage to boost Edgley out of the water, but sharks don’t need a boost. Edgley opted to work with a monofin, frequently used in underwater sports like free diving or finswimming, to see what he could achieve on his own power. After a bit of practice, he succeeded in launching 75 percent of his body (compared to the shark’s 100 percent) out of the water. Verdict: Edgley is 75 percent great white shark.
Ross vs. the hammerhead shark
Edgley vs. a hammerhead shark. He will try to match the animal’s remarkable agility underwater.
National Geographic/Nathalie Miles
A camera team films a hammerhead shark making sharp extreme turns
National Geographic/Nathalie Miles
Edgley prepares to go airborne in a stunt plane to try and mimic the agility of a hammerhead shark in the water.
National Geographic/Nathalie Miles
A standard roll produces 2 g’s, while pulling up is 3 g’s
YouTube/National Geographic
Edgley is feeling a bit queasy.
YouTube/National Geographic
Next up: Edgley pitted himself against the remarkable underwater agility of a hammerhead shark. Hammerheads are known for being able to swim fast and turn on a dime, thanks to a flexible skeleton that enables them to bend and contort their bodies nearly in half. They’re able to withstand some impressive G forces (up to 3 G’s) in the process. According to Heithaus, these sharks feed on other rays and other sharks, so they need to be built for speed and agility—hence their ability to accelerate and turn rapidly.
The NatGeo crew captured impressive underwater footage of the hammerheads in action, including Edgley meeting a 14.7 hammerhead named “Queenie”—one of the largest great hammerheads that visits Bimini in the Bahamas during the winter. That footage also includes shots of divers feeding fish to some of the hammerheads by hand. “They know every shark by name and the sharks know the feeders,” said Heithaus. “So you can safely get close to these big amazing creatures.”
For years, scientists had wondered about the purpose of the distinctive hammer-shaped head. It may help them scan a larger area of the ocean floor while hunting. Like all sharks, hammerheads have sensory pores called ampullae of Lorenzini that allow them to detect electrical signals and hence possible prey. The hammer-shaped head distributes those pores over a wider span.
But according to Heithaus, the hammer shape also operates a bit like the big broad flap of an airplane wing, resulting in excellent hydrodynamics. Moving at high speeds, “You can just tilt the head a tiny bit and bank a huge degree,” he said. “So if a ray turns 180 degrees to escape, the hammerhead can track with it. Other species would take a wider turn and fall behind.”
The airplane wing analogy gave Edgley an idea for how he could mimic the tight turns and high G forces of a hammerhead shark: take a flight in a small stunt plane. The catch: Edgley is not a fan of flying. And as he’d feared, he became horribly airsick during the challenge, even puking into a little airbag at one point. “It looks so cool in the clip,” he said. “But at the time, I was in a world of trouble.” Pilot Mark Greenfield finally cut the experiment short when he determined that Edgley was too sick to continue. Verdict: Edgley is 0 percent hammerhead shark.
Ross vs. the tiger shark
Shark expert Mike Heithaus holds a gelatin shark “lolliop” while Edgley flexes.
National Geographic/Nathalie Miles
Edgley and Heithaus underwater with a tiger shark, tempting it with a gelatin lollipop.
National Geographic/Nathalie Miles
Success! A tiger shark takes a nice big bite.
National Geographic/Nathalie Miles
Edgley flexes with the giant gelatin lollipop with a large bite taken out of it by a tiger shark
National Geographic/Nathalie Miles
Edgley gets his weight and body volume measured in the “Bodpod” before his tiger shark challenge.
National Geographic/Bobby Cross
Edgley fasted and exercised for 24 hours to mimic a tiger shark on a migration route. He dropped 14 pounds.
National Geographic/Nathalie Miles
After all that fasting and exercise, Edgley then gorged himself for 24 hours to put the weight back on. He gained 22 pounds.
National Geographic/Nathalie Miles
The third challenge was trying to match the fortitude of a migrating tiger shark as it makes its way over thousands of miles without food, only feasting at journey’s end. “I was trying to understand the psychology of a tiger shark because there’s just nothing for them to eat [on the journey],” said Ross. And once they arrive at their destination, “they can chow down on entire whale carcasses and eat just about anything. That idea of feast and famine is something we humans used to do all the time. We live quite comfortably now so we’ve lost touch with that.”
The first step was to figure out just how many calories a migrating tiger shark can consume in a single bite. Heithaus has been part of SHARKFEST for several years now and recalled one throwback show, Sharks vs. Dolphins, in which he tried to determine which species of of shark were attacking dolphins, and just how big those sharks might be. He hit upon the idea of making a dolphin shape out of gelatin—essentially the same stuff FIU’s forensic department uses for ballistic tests—and asked his forensic colleagues to make one for him, since the material has the same weight and density of dolphin blubber.
For the Edgley documentary, they made a large gelatin lollipop the same density as whale blubber, and he and Edgley dove down and managed to get an 11-foot tiger shark to take a big 6.2-pound bite out of it. We know how many calories are in whale blubber so Heithaus was able to deduce from that how many calories per bite a tiger shark consumed (6.2 pounds of whale meet is equivalent to about 25,000 calories).
Such field work also lets him gather ever mire specimens of shark bites from a range of species for his research. “The great thing about SHARKFEST is that you’re seeing new, cutting-edge science that may or may not work,” said Heithaus. “But that’s what science is about: trying things and advancing our knowledge even if it doesn’t work al the time, and then sharing that information and excitement with the public.”
Then it was time for Edgley to make like a migrating shark and embark on a carefully designed famine-and-feast regime. First, his weight and body volume were measured in a “Bodpod”: 190.8 pounds and 140.8 pints. Then Edgley fasted and exercised almost continuously for 24 hours with a mix of weight training, running, swimming, sitting in the sauna, and climate chamber cycling. (He did sleep for a few hours.) He dropped 14 pounds and lost twelve pints, ending up at a weight of 177 pounds and a volume of 128.7 pints. Instead of food, what he craved most at the end was water. “When you are in a completely deprived state, you find out what your body actually needs, not what it wants,” said Edgley.
After slaking his thirst, it was time to gorge. Over the next 24 hours, Edgley consumed an eye-popping 35,103 calories in carefully controlled servings. It’s quite the menu: Haribo mix, six liters of Lucozade, a Hulk smoothie, pizza, five slices of lemon blueberry cheesecake, five slices of chocolate mint cheesecake, fish and chips, burgers and fries, two cinnamon loaves, four tubs of Ben & Jerry’s ice cream, two full English breakfasts, five liters of custard, four mars bars, and four mass gainer shakes.
When his weight and volume were measured one last time in the Bodpod, Edgley had regained a whopping 22 pounds for a final weight of 199 pounds. “I wish I had Ross’s ability to eat that much and remain at 0 percent body fat,” said Heithaus. Verdict: Edgley is 28 percent tiger shark.
Ross vs. the mako shark
In 2018, Edgely set the world record for longest assisted sea swim.
National Geographic/Nathalie Miles
Edgley tries to match the speed of a mako shark in the waters of the Menai Strait in Wales.
National Geographic/Nathalie Miles
Finally, Edgley pitted himself against the mighty mako shark. Mako sharks are the speediest sharks in the ocean, capable of swimming at speeds up to 43 MPH. Edgley is a long-distance swimmer, not a sprinter, so he threw himself into training at Loughborough University with British Olympians coaching him. He fell far short of a mako shark’s top speed. The shape of the human body is simply much less hydrodynamic than that of a shark. He realized that despite his best efforts, “I was making up hundredths of a second, which is huge in sprinting,” he said. “That could be the difference between a gold medal at the Paris Olympics and not. But I needed to make up many kilometers per hour.”
So Edgley decided to “think like a shark” and employ a shark-like strategy of riding the ocean currents to increase his speed. He ditched the pool and headed to the Menai Strait in Wales for some open water swimming. Ultimately he was able to hit 10.24 MPH—double what an Olympic swimmer could manage in a pool, but just 25 percent of a mako shark’s top speed. And he managed with the help or a team of 20-30 people dropping him into the fastest tide possible. “A mako shark would’ve just gone, ‘This is a Monday morning, this isn’t an event for me, I’m off,'” said Edgley. Verdict: Edgley is 24 percent mako shark
When the results of all four challenges were combined, Edgley came out at 32 percent overall, or nearly one-third shark. While Edgley confessed to being humbled by his limitations, “I don’t think there’s anyone else out there who could do so as well across the board in comparison,” said Heithaus.
The ultimate goal of Shark vs. Ross Edgley—and indeed all of the SHARKFEST programming—is to help shift public perceptions of sharks. “The great Sir David Attenborough said that the problems facing us in terms of conservation is as much a communication issue as a scientific one,” Edgley said. “The only way we can combat that is by educating people.”
Shark populations have declined sharply by 70 percent or more over the last 50 years. “It’s really critical that we protect and restore these populations,” Heithaus said. Tiger sharks, for instance, eat big grazers like turtles and sea cows, and thus protect the sea grass. (Among other benefits, the sea grass sequesters carbon dioxide.) Sharks are also quite sophisticated in their behavior. “Some have social connections with other sharks, although not to the same extent as dolphins,” said Heithaus. “They’re more than just loners, and they may have personalities. We see some sharks that are more bold, and others that are more shy. There’s a lot more to sharks than we would have thought.”
People who hear about Edgley’s basking shark encounter invariably assume he’d been in danger. However, “We were friends. I’m not on its menu,” Edgley said. “There are so many different species.” He likened it to being chased by a dog. People might assume it was a rottweiler giving chase, when in fact the basking shark is the equivalent of a poodle. “Hopefully what people take away from this is moving from a fear and misunderstanding of sharks to respect and admiration,” Edgley said. “That’ll make the RAF fighter pilot plane worth it.”
And he’s game to take on even more shark challenges in the future. There are a lot more shark species out there, after all, just waiting to go head-to-head with a human ultra-athlete.
Shark vs. Ross Edgley premieres on Sunday, June 30, 2024, on Disney+.
Enlarge/ This aerial picture taken on December 8, 2023, shows the US-Mexico border wall in Sasabe, Arizona.
In a vast stretch of the Sonoran Desert, between the towns of San Luis Río Colorado and Sonoyta in northern Mexico, sits a modest building of cement, galvanized sheet metal, and wood—the only stop along 125 miles of inhospitable landscape dominated by thorny ocotillo shrubs and towering saguaro cactuses up to 50 feet high. It’s a fonda—a small restaurant—called La Liebre del Desierto (The Desert Hare), and for more than 20 years, owner Elsa Ortiz Ramos has welcomed and nourished weary travelers taking a break from the adjacent highway that runs through the arid Pinacate and Grand Desierto de Altar Biosphere Reserve.
But the dedication and care of this petite woman go beyond her simple menu. Every two weeks, she pays out of pocket for a 5,000-gallon tank of water to distribute to a network of water troughs strategically placed in the area. By doing so, she relieves the thirst of bighorn sheep, ocelots, pronghorn, coyotes, deer, and even bats that have been deprived of access to their natural water sources.
“The crows come to the house and scream to warn us that there is no more water … it’s our alarm,” says Ortiz Ramos in her distinct northern Mexico accent. Her words sound straight from an Aesop’s fable, but they take on stark realism in this spot. Covering large parts of Arizona, California, and the Mexican states of Baja California and Sonora, the Sonoran Desert—along with the Lut Desert in Iran—was cataloged in 2023 as having the hottest surface temperature on the planet, at 80.8° Celsius (177° Fahrenheit).
Through narrow steel bollards 3.5 inches apart, I observe lush vegetation surrounding the Quitobaquito spring on the other side of the border. “This vital source supplies both humans and animals over an area of more than 1 million hectares,” Federico Godínez Leal, an agronomist from the University of Guadalajara, explains to me. But now this crucial water source is restricted to the US side due to the construction of the border wall, and I have come with him here to understand the consequences. Godínez Leal and his team have been documenting the stark difference between each side: Their poignant photographs show skeletons of wild boar, deer, and bighorn sheep lying on Mexican soil.
Between 2017 and 2021, the US government installed more than 450 miles of border barriers—steel structures between 18 and 29 feet high, spaced less than 4 inches apart—in the western end of the more than 1,900 miles of border between Mexico and the United States, stretching from the Pacific Ocean to the Gulf of Mexico. Of these 450 miles, 81 percent were replacements of existing vehicular or pedestrian barriers—but which, due to their design, allowed some passage of animals across the border. The rest were new barriers.
Before its construction, scientists on both sides of the border had warned about the impact that the wall could have on the animals of the area, and they are now working to understand the consequences. In turn, villagers in some spots on the Mexican side of the border have organized to try to alleviate the thirst of many animals that have been left without access to water.
