Category: Science

TAMPA, Fla. — Viasat is considering investing in spacecraft with other Mobile Satellite Service (MSS) operators as the promise of direct-to-smartphone technology drives unprecedented cooperation among historically isolated networks.

“What you’ve seen in MSS in the past is every operator has to have its own satellite, its own ground segment, its own type of terminals [and] they only use their own spectrum,” Viasat CEO Mark Dankberg said.

“But what we’re envisioning is creating an environment where you can roam from MSS operator to MSS operator seamlessly, and you can do that in different geographies or within the same geography.”

Pooling radiowaves in the same area could deliver more capacity for direct-to-smartphone services, enabling higher bandwidth text, voice, and data capabilities for phones outside cellular coverage.

Dankberg is chair of the Mobile Satellite Services Association (MSSA), a non-profit group of MSS operators founded in February to push the fledgling direct-to-smartphone market to adopt their radio waves, rather than spectrum sourced from terrestrial mobile network operators.

Other founding MSSA members include Terrestar Solutions, Ligado Networks, Omnispace, and Yahsat. Iridium Communications has also said it is considering joining MSSA after pivoting from a proprietary direct-to-smartphone strategy to an open network approach.

MSS operator Globalstar, which thanks to its close relationship with Apple has been enabling space-based SOS services on the latest iPhones since late 2022, is not part of MSSA.

“A satellite is just a cell tower in space,” Dankberg said in an interview. “The payload is what does the work. So just like in terrestrial, where you can put a payload — or a network — from multiple carriers on the same tower, why can’t we make the same satellites for all of our needs?”

Similar to how cell tower companies operate on the ground, he said sharing infrastructure in space could save costs and attract capital.

“We can have tower companies in space that can serve all of us [and are] far more capital efficient,” he added, “we can do similar things with ground infrastructure in particular markets.”

Coordination agreements among MSS operators currently separate them from each other to avoid radio wave interference. Through MSSA, the operators hope to create a standards-based framework that could pave the way for contractual agreements to share and empower their orbital resources. 

Partnerships mobile network operators have with cell tower companies on the ground include leasing and revenue-sharing business models. 

Dankberg pointed to Indian cellular operator Reliance Jio, which has helped lower barriers to entry through partnerships with power companies, network providers, and handset makers.

“What we’re looking to do is to figure out which of those we can replicate in what sequence,” he said.

“Maybe the MSS operators themselves cooperate, maybe third parties come in to invest in the space segment.”

The aim is to help build scale globally and drive out costs as direct-to-smartphone operators SpaceX, Lynk Global, and AST SpaceMobile seek more mobile network operator partners for their terrestrial spectrum approach.

“Coopertition is kind of the buzzword for that,” Dankberg added, “whereby cooperating we make the market bigger and we compete on that larger market, but that’s a way better way to compete than on the small market scales that at the MSS operators have now.”

According to Dankberg, existing regulations already support MSS spectrum pooling, and it is up to MSSA members to coordinate among themselves.

Regulatory clarity is one of the strengths of the MSS direct-to-smartphone approach because these radio waves are already cleared for use from space, although services to standard smartphones must wait for standardized chips to be released.

Satellites using cellular radio waves can reach smartphones already in circulation because these devices use these frequencies with land-based cell towers. 

However, these terrestrial partnerships must first navigate new rules that must be put in place to guard against the possibility of interference in each country they wish to operate in.

The United States is taking the lead on this, and the Federal Communications Commission recently issued nationwide ground rules for what it calls Supplemental Coverage from Space that is expected to inspire other countries.

Meanwhile, Lynk Global is currently enabling intermittent texting services with five satellites in parts of a handful of island nations. Like fellow early-stage venture AST SpaceMobile, which does not expect to launch initial commercial satellites until at least July, Lynk is seeking more capital to expand its constellation.

Leveraging significantly greater financial resources, SpaceX aims to enable direct-to-smartphone texting services in the United States this year, with voice and data services slated to come soon after.

Omnispace, however, has warned that SpaceX’s plans to use T-Mobile’s cellular radio waves from space could cause interference that would derail its proposed MSS constellation.

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Individual ice grains ejected from some of the moons orbiting Saturn and Jupiter may contain enough material for instruments headed there in the fall to detect signs of life, if such life exists.

The ice-encrusted oceans of these planetary bodies are leading candidates in the search for extraterrestrial life.

“For the first time we have shown that even a tiny fraction of cellular material could be identified by a mass spectrometer onboard a spacecraft,” says lead author Fabian Klenner, a University of Washington postdoctoral researcher in earth and space sciences.

“Our results give us more confidence that using upcoming instruments, we will be able to detect lifeforms similar to those on Earth, which we increasingly believe could be present on ocean-bearing moons.”

The Cassini mission that ended in 2017 discovered parallel cracks near the south pole of Saturn’s moon Enceladus. Emanating from these cracks are plumes containing gas and ice grains. NASA’s Europa Clipper mission, scheduled to launch in October, 2024, will carry more instruments to explore in even more detail an icy moon of Jupiter, Europa.

To prepare for that mission, researchers are studying what this new generation of instruments might find. It is technically prohibitive to directly simulate grains of ice flying through space at 4 to 6 kilometers per second to hit an observational instrument, as the actual collision speed will be. Instead, the authors used an experimental setup that sends a thin beam of liquid water into a vacuum, where it disintegrates into droplets. They then used a laser beam to excite the droplets and mass spectral analysis to mimic what instruments on the space probe will detect.

Newly published results show that instruments slated to go on future missions, like the SUrface Dust Analyzer onboard Europa Clipper, can detect cellular material in one out of hundreds of thousands of ice grains.

The study focused on Sphingopyxis alaskensis, a common bacterium in waters off Alaska. While many studies use the bacterium Escherichia coli as a model organism, this single-celled organism is much smaller, lives in cold environments, and can survive with few nutrients. All these things make it a better candidate for the kinds of life that may exist on the icy moons of Saturn or Jupiter.

“They are extremely small, so they are in theory capable of fitting into ice grains that are emitted from an ocean world like Enceladus or Europa,” Klenner says.

Results show that the instruments can detect this bacterium, or portions of it, in a single ice grain. Different molecules end up in different ice grains. The new research shows that analyzing single ice grains, where biomaterial may be concentrated, is more successful than averaging across a larger sample containing billions of individual grains.

A recent study led by the same researchers showed evidence of phosphate on Enceladus. This planetary body now appears to contain energy, water, phosphate, other salts, and carbon-based organic material, making it increasingly likely to support lifeforms similar to those found on Earth.

The authors hypothesize that if bacterial cells are encased in a lipid membrane, like those on Earth, then they would also form a skin on the ocean’s surface. On Earth, ocean scum is a key part of sea spray that contributes to the smell of the ocean. On an icy moon where the ocean is connected to the surface, for example through cracks in the ice shell, the vacuum of outer space would cause this subsurface ocean to boil. Gas bubbles rise through the ocean and burst at the surface, where cellular material gets incorporated into ice grains within the plume.

“We here describe a plausible scenario for how bacterial cells can, in theory, be incorporated into icy material that is formed from liquid water on Enceladus or Europa and then gets emitted into space,” Klenner says.

The SUrface Dust Analyzer onboard Europa Clipper will be higher-powered than instruments on past missions. This and future instruments also will for the first time be able to detect ions with negative charges, making them better suited to detecting fatty acids and lipids.

“For me, it is even more exciting to look for lipids or for fatty acids, than to look for building blocks of DNA, and the reason is because fatty acids appear to be more stable,” Klenner says.

“With suitable instrumentation, such as the SUrface Dust Analyzer on NASA’s Europa Clipper space probe, it might be easier than we thought to find life, or traces of it, on icy moons,” says senior coauthor Frank Postberg, a professor of planetary sciences at the Freie Universität Berlin. “If life is present there, of course, and cares to be enclosed in ice grains originating from an environment such as a subsurface water reservoir.”

The study appears in Science Advances. Additional authors are from the Open University in the UK; NASA’s Jet Propulsion Laboratory; the University of Colorado, Boulder; and the University of Leipzig, and the Freie Universität Berlin.

Funding for the study came from the European Research Council, NASA and the German Research Foundation (DFG).

Source: University of Washington

The Jet Propulsion Laboratory in Pasadena, California, is home base for building pioneering spacecraft that have probed every planet in our solar system, including the Sun.

Federally funded by NASA and managed by Caltech, JPL and its cadre of engineers and scientists are led by Laurie Leshin, the first woman to serve as JPL director, who took on the role in May 2022 following a career as a geochemist in academia and NASA.

Leshin points to space technology achievements, but has also been plagued by program setbacks and space budget woes, especially regarding the JPL-led Mars Sample Return project.

Leshin spoke with SpaceNews about JPL’s path forward and steps to retain and bolster the revered laboratory’s capabilities.

How do you characterize your concerns about NASA’s overall budget and its impact on JPL?

There is good news for sure, such as the VERITAS Venus orbiter coming back and that we’re now re-planning and ramping back up. Most of the [NASA] science budget is fairly flat which, while not great, is not terrible. Planetary science, however, finds itself in a very, very difficult position. It is a fairly unprecedented threat to the nation’s deep space capability which is resident at JPL, so I have major concerns.

How impactful were February’s budget-related layoffs on the lab’s future?

We hire only great people. So we will miss all those who were laid off. We’re supporting them in every way we can think of through their transition. While it cut to depth, it did not eliminate any core capability. We worked very hard in spite of having to make the deep cuts and to make sure those capabilities were intact.

What is an example of a core capability at JPL?

Our nation’s Mars exploration capability is resident at the lab. No other organization has landed on Mars in the United States except us — with partners always, but we have led every one of those missions. But if the budget challenges continue or decisions continue to be deferred, those capabilities will be at risk. I don’t know how to say it other than that.

Our job as a nation is to have some hard conversations about what being spacefaring for the future really means. How do we make sure that there’s Mars in our moon-to-Mars program? There’s no moon-to-Mars without Mars and there’s no Mars without JPL.

Any other NASA budget concerns?

A science versus human spaceflight moment is not good for our community. We all need to pull together to support the diverse portfolio that NASA has. In tight budget times, we tend to fight with each other and that is always a bad idea.

JPL leads the development of the Europa Clipper mission. All on track for liftoff this October?

Europa Clipper just came out of JPL’s thermal vacuum chamber. You shake it. You bake it. You look for magnetic cleanliness. End-to-end missions tests to simulate launch, solar array deployment, deep space cruise, orbit insertion at Jupiter, flybys of Europa. We’ve done all of that. We’re in really good shape. We’re on track to ship it to Florida in the May timeframe and get it ready to fly on a SpaceX Falcon Heavy.

There’s another look looming at the costly and complex Mars Sample Return program. What’s coming?

I can’t talk about it at this time. That review is coming relatively soon… to be released in the spring. NASA has funding challenges. It’s a really important set of decisions they are making. Mars Sample Return was the next big thing at JPL. So we need to make sure that gets back on track as quickly as possible.

So you see a way forward for Mars Sample Return?

It’s a difficult moment. There’s a way to move forward with this mission that will cost less on an annual basis than the prior plan and it’s very much in line with what we’ve spent on other large missions. NASA has a chance to go down that path. I hope they will… and then I’ll breathe.

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A new study finds that storing chemicals in a garage at home may be linked with an increased risk of ALS.

Over the last decade, researchers at University of Michigan continue to find that exposure to environmental toxins—from pesticides used in agriculture to volatile organic compounds in the manufacturing industry—is linked to the development of amyotrophic lateral sclerosis, or ALS.

The buildup of exposures, which researchers call the ALS exposome, is possibly associated with recreational activities such as woodworking and gardening.

“Identifying disease-provoking exposures can inform and motivate interventions to reduce exposure, risk, and, ultimately, the ALS burden,” says first author Stephen Goutman, director of the Pranger ALS Clinic and associate director of the ALS Center of Excellence at University of Michigan.

“Exposures in the home setting are an important part of the ALS exposome, as it is one place where behavior modifications could possibly lessen ALS risk.”

Storage containing volatile chemicals in garages is extremely common, whether it’s in a car or motorcycle, equipment like a chainsaw, or solvents, cleaners, paints, and other items.

Investigators assessed exposures in the residential setting from a survey of more than 600 participants both with and without ALS. Through statistical analysis, they found that the storage of chemicals—including gasoline and gasoline powered equipment, lawn care products, pesticides, paint, and woodworking supplies—were significantly associated with ALS risk.

All of the reported chemicals linked to disease development were volatile with toxic components. Most participants reported storing several of the items in their attached garage.

Storing chemicals in a detached garage, however, did not show as strong of an association with risk.

The researchers say the flow of air and airborne pollutants from attached garages to the living space may explain the finding.

“Especially in colder climates, air in the garage tends to rush into the house when the entry door is opened, and air flows occur more or less continuously through small cracks and openings in walls and floors,” says Stuart Batterman, senior author and professor of environmental health science at the University of Michigan School of Public Health.

“Thus, it makes sense that keeping volatile chemicals in an attached garage shows the stronger effect.”

The latest building codes, Batterman notes, tackle this problem by specifying measures to reduce or eliminate these air flows.

“We are beginning to see risk factors across multiple settings that may associate with a greater ALS risk; we also see some relationships across the studies, for example, woodworking and woodworking supplies and gardening and lawn care supplies,” Goutman says.

“This begs the question: is it the activities that associate with ALS risk or the exposures to related products? This requires further research.”

In 2016, the research team found that people with ALS had higher concentrations of pesticides in their blood compared to people without the condition.

A subsequent study published in 2019 linked organochlorine pesticides and polychlorinated biphenyls, or PCBS, to worsening survival for ALS.

“With each study, we better understand the types of exposures that increase the risk of developing ALS,” says senior author Eva Feldman, director of the ALS Center of Excellence at the University of Michigan.

“We now need to build on these discoveries to understand how these exposures increase ALS risk. In parallel, we must continue to advocate to make ALS a reportable disease. Only then we will fully understand the array of exposures that increase disease risk.”

Studies to understand how environmental exposures contribute to the development of ALS and other neurodegenerative diseases, both of people with and without family history of the condition, are underway.

The research appears in Amyotrophic Lateral Sclerosis and Frontotemporal Degeneration.

Funding for the study came from the National Institutes of Health, The National ALS Registry/CDC/ATSDR, the ALS Association, the NeuroNetwork for Emerging Therapies, the Robert and Katherine Jacobs Environmental Health Initiative, the NeuroNetwork Therapeutic Discovery Fund, the Peter R. Clark Fund for ALS Research, the Sinai Medical Staff Foundation, Scott L. Pranger, and the University of Michigan.

Source: University of Michigan

Researchers have a new theory about the origins and spread of Parkinson’s disease.

The nose or the gut? For the past two decades, the scientific community has debated the wellspring of the toxic proteins at the source of Parkinson’s disease.

In 2003, a German pathologist, Heiko Braak, first proposed that the disease begins outside the brain. More recently, Per Borghammer with Aarhus University Hospital in Denmark and his colleagues argued that the disease is the result of processes that start in either the brain’s smell center (brain-first) or the body’s intestinal tract (body-first).

A new hypothesis paper unites the brain- and body-first models with some of the likely causes of the disease—environmental toxicants that are either inhaled or ingested.

The authors of the new study argue that inhalation of certain pesticides, common dry cleaning chemicals, and air pollution predispose to a brain-first model of the disease. Other ingested toxicants, such as tainted food and contaminated drinking water, lead to body-first model of the disease.

“In both the brain-first and body-first scenarios the pathology arises in structures in the body closely connected to the outside world,” says Ray Dorsey, a professor of neurology at the University of Rochester Medical Center and coauthor of the study published in the Journal of Parkinson’s Disease.

“Here we propose that Parkinson’s is a systemic disease and that its initial roots likely begin in the nose and in the gut and are tied to environmental factors increasingly recognized as major contributors, if not causes, of the disease. This further reinforces the idea that Parkinson’s, the world’s fastest growing brain disease, may be fueled by toxicants and is therefore largely preventable.”

Lewy bodies

A misfolded protein called has been in scientists’ sights for the last 25 years as one of the driving forces behind Parkinson’s. Over time, the protein accumulates in the brain in clumps, called Lewy bodies, and causes progressive dysfunction and death of many types of nerve cells, including those in the dopamine-producing regions of the brain that control motor function. When first proposed, Braak thought that an unidentified pathogen, such as a virus, may be responsible for the disease.

The new study argues that toxins encountered in the environment, specifically the dry cleaning and degreasing chemicals trichloroethylene (TCE) and perchloroethylene (PCE), the weed killer paraquat, and air pollution, could be common causes for the formation of toxic alpha-synuclein.

TCE and PCE contaminates thousands of former industrial, commercial, and military sites, most notably the Marine Corps base Camp Lejeune, and paraquat is one of the most widely used herbicides in the US, despite being banned for safety concerns in more than 30 countries, including the European Union and China. Air pollution was at toxic levels in nineteenth century London when James Parkinson, whose 269th birthday is April 11, first described the condition. April 11 is World Parkinson’s Day.

Parkinson’s tremors

The nose and the gut are lined with a soft permeable tissue, and both have well established connections to the brain. In the brain-first model, the chemicals are inhaled and may enter the brain via the nerve responsible for smell. From the brain’s smell center, alpha-synuclein spreads to other parts of the brain principally on one side, including regions with concentrations of dopamine-producing neurons.

The death of these cells is a hallmark of Parkinson’s disease. The disease may cause asymmetric tremor and slowness in movement and, a slower rate of progression after diagnosis, and only much later, significant cognitive impairment or dementia.

When ingested, the chemicals pass through the lining of the gastrointestinal tract. Initial alpha-synuclein pathology may begin in the gut’s own nervous system from where it can spread to both sides of the brain and spinal cord. This body-first pathway is often associated with Lewy body dementia, a disease in the same family as Parkinson’s, which is characterized by early constipation and sleep disturbance, followed by more symmetric slowing in movements and earlier dementia, as the disease spreads through both brain hemispheres.

Environmental role

“These environmental toxicants are widespread and not everyone has Parkinson’s disease,” Dorsey says. “The timing, dose, and duration of exposure and interactions with genetic and other environmental factors are probably key to determining who ultimately develops Parkinson’s. In most instances, these exposures likely occurred years or decades before symptoms develop.”

Pointing to a growing body of research linking environmental exposure to Parkinson’s disease, the authors believe the new models may enable the scientific community to connect specific exposures to specific forms of the disease. This effort will be aided by increasing public awareness of the adverse health effects of many chemicals in our environment.

The authors conclude that their hypothesis “may explain many of the mysteries of Parkinson’s disease and open the door toward the ultimate goal—prevention.”

In addition to Parkinson’s, these models of environmental exposure may advance understanding of how toxicants contribute to other brain disorders, including autism in children, ALS in adults, and Alzheimer’s in seniors.

Dorsey and his colleagues at the University of Rochester have organized a Brain and the Environment symposium in Washington, DC, on May 20 that will examine the role toxicants in our food, water, and air are playing in all these brain diseases.

Additional coauthors of the hypothesis paper are from the University of Alabama at Birmingham and Aarhus University Hospital.

Source: University of Rochester

People who work irregular job schedules staring at 22 are more likely to report sleep issues, poor health, and depressive symptoms by age 50, according to a new study.

With the rise of the US service economy and technological progress, researchers are taking a closer look at the impact of erratic work hours on the health of employees—nurses who make rounds into the predawn hours, burger flippers with irregular shifts, and software engineers who stay “in the zone” long past midnight.

The study shows that schedule chaos, an increasing phenomenon, can take a serious toll. Wen-Jui Han, a professor in the New York University Silver School of Social Work, with training in sociology, economics, developmental psychology, and public policy, led the study.

Published in the journal PLOS ONE, the study looks at how one’s social position “plays a significant role in these adverse health consequences” from working jobs with shifts outside the more traditional 9 am to 5 pm.

The findings show that individuals occupying a lower social position, such as those who did not go to college or whose job status may be precarious, are more likely than some others to suffer from inadequate or poor sleep.

Here are some additional takeaways from the study:

• Han’s research is the first scholarship on this topic to use longitudinal studies and a life-course perspective (with sequence analysis) to examine how work schedule patterns, whether consistently or periodically irregular starting in our early 20s, might be associated with our sleep and health as we approach mid-life.
• Her analysis relies on the National Longitudinal Study of Youth, a nationally representative sample of about 7,000 people in the US conducted over three decades. The data collection began in 1979, asking participants about their sleep and mental and physical health over time along with their evolving work schedules.
• Nonstandard work schedules, very prevalent across the US since at least the 1980s, are increasingly becoming a global phenomenon.
• The significantly poorer sleep and health outcomes observed through the longitudinal analysis are concentrated among people with vulnerable social positions, such as women, racial minorities, and those without a college degree.
• As expected, socioeconomic factors such as wages, marital status, education, and poverty are significantly associated with problematic sleep and health. But there are exceptions. Black workers, both women and men, reported a lower likelihood of having depressive symptoms than their white counterparts, for example. White women, particularly those with less than a high school education, reported the highest likelihood of depressive symptoms.

“In reality, our work patterns are more volatile and diverse than we can imagine,” says Han, whose research reveals that shifting schedules were relatively common among workers between ages 22 and 49, whether they started out working standard hours and transitioned to something more variable, or worked mainly 9-to-5 with some night shifts mixed in.

“About three-quarters of the work patterns we observed did not strictly conform to working stably during daytime hours throughout our working years. This has repercussions.”

People with work patterns involving any degree of volatility, she explains, are more likely to have fewer hours of sleep per day, lower sleep quality, lower physical and mental functions, and a higher likelihood of reporting poor health and depressive symptoms at 50 years old than those with stable standard work schedules.

Those adverse health consequences from nonstandard work schedule patterns—whether taking care of one’s own children at home or working a job for pay—are “alarming,” the study concludes, especially in light of the scholarship revealing that an adequate amount of quality sleep is important for heading off anxiety and depression, hypertension, obesity, or even stroke.

And “the picture becomes grimmer if we further disentangle these links by social position,” Han writes.

Source: NYU

Researchers have developed synthetic platelets that can be used to stop bleeding and enhance healing at the site of an injury.

The researchers have demonstrated that the synthetic platelets work well in animal models but have not yet begun clinical trials in humans.

A number of medical situations require platelet transfusions—such as cases of severe bleeding, or for patients who are going into surgery or receiving chemotherapy.

Currently, patients in any of those situations receive platelets harvested from blood donors, ideally from donors with a compatible blood type. This is challenging, because there is a very limited supply of platelets available, those platelets have a limited shelf life, and the platelets must be stored under controlled conditions.

“We’ve developed synthetic platelets that can be used with patients of any blood type and are engineered to go directly to the site of injury and promote healing,” says Ashley Brown, an associate professor in the joint biomedical engineering program at North Carolina State University and the University of North Carolina at Chapel Hill and corresponding author of the study published in the journal Science Translational Medicine.

“The synthetic platelets are also easy to store and transport, making it possible to give the synthetic platelets to patients in clinical situations sooner—such as in an ambulance or on the battlefield.”

The platelets are made of hydrogel nanoparticles that mimic the size, shape, and mechanical properties of human platelets. Hydrogels are water-based gels that are composed of water and a small proportion of polymer molecules.

“Our synthetic platelets are deformable—meaning they can change shape—in the same way that normal platelets are,” Brown says.

The researchers engineered the surface of the synthetic platelets to incorporate antibody fragments that bind to a protein called fibrin. When a body is injured, it synthesizes fibrin at the site of the wound. The fibrin then forms a mesh-like substance to promote clotting.

“Because the synthetic platelets are coated with these antibody fragments, the synthetic platelets travel freely through the blood stream until they reach the wound site,” Brown says. “Once there, the antibody fragments bind to the fibrin, and the synthetic platelets expedite the clotting process.”

In addition to forming a clot within the fibrin network, the synthetic platelets act to contract the clot over time—just like normal platelets.

“This expedites the process of healing, allowing the body to move forward with tissue repair and recovery,” Brown says.

The researchers initially demonstrated the efficacy of the antibody fragments via in vitro testing, as well as demonstrating that the antibody fragments and synthetic platelets could be produced at scales that would make them viable for large-scale manufacturing.

The researchers then used a mouse model to determine the optimal dose of synthetic platelets necessary to stop bleeding.

Subsequent research in both mouse and pig models demonstrated that the synthetic platelets traveled to the site of a wound, expedited clotting, did not cause any clotting problems in areas outside of the wound, and accelerated healing.

“In the mouse and pig models, healing rates were comparable in animals that received platelet transfusions and synthetic platelet transfusions,” Brown says. “And both groups fared better than animals that did not receive either transfusion. We also found that the animals in both mouse and pig models were able to safely clear the synthetic platelets over time through normal kidney function. We didn’t see any adverse health effects associated with the use of the synthetic platelets.

“In addition, based on our preliminary estimates, we anticipate that the cost of the synthetic platelets—if they are approved for clinical use—would be comparable to the current cost of platelets,” Brown says.

“We are wrapping up preclinical efficacy testing and are in the process of securing funding for preclinical safety work that should allow us to obtain FDA approval to begin clinical trials within two years.”

Additional coauthors are from NC State, the University of North Carolina at Chapel Hill, the University of Virginia, Duke University, and Chapman University.

Brown and coauthors Seema Nandi, Andrew Lyon of Chapman University, and Thomas Barker, of the University of Virginia, are all cofounders of a start-up company called SelSym Biotech that is focused on developing and marketing synthetic platelets for clinical use. Nellenbach owns stock in SelSym Biotech.

This research was done with support from the National Heart, Lung, and Blood Institute; the National Institute of General Medical Sciences; the National Institutes of Health; the Department of Defense; the National Science Foundation; the American Heart Association; the US Department of Veterans Affairs; and the North Carolina State University Chancellor’s Innovation Fund.

Source: NC State

Swimming in schools makes fish surprisingly stealthy underwater, with a group able to sound like a single fish, researchers report.

The study offers new insight into why fish swim in schools and holds promise for the design and operation of much quieter submarines and autonomous undersea vehicles.

“It’s widely known that swimming in groups provides fish with added protection from predators, but we questioned whether it also contributes to reducing their noise,” says senior author Rajat Mittal, a researcher at the Johns Hopkins Whiting School of Engineering.

“Our results suggest that the substantial decrease in their acoustic signature when swimming in groups, compared to solo swimming, may indeed be another factor driving the formation of fish schools.”

For the study, published in the journal Bioinspiration & Biomimetics, the team created a 3D model based on the common mackerel to simulate different numbers of fish swimming, changing up their formations, how close they swam to one another, and the degrees to which their movements synched. The model, which applies to many fish species, simulates one to nine mackerel being propelled forward by their tail fins.

The team found that a school of fish moving together in just the right way was stunningly effective at noise reduction: A school of seven fish sounded like a single fish.

“A predator, such as a shark, may perceive it as hearing a lone fish instead of a group,” Mittal says. “This could have significant implications for prey fish.”

The single biggest key to sound reduction, the team found, was the synchronization of the school’s tail flapping—or actually the lack thereof.

If fish moved in unison, flapping their tail fins at the same time, the sound added up and there was no reduction in total sound. But if they alternated tail flaps, the fish canceled out each other’s sound, the researchers found.

“Sound is a wave,” Mittal says. “Two waves can either add up if they are exactly in phase or they can cancel each other if they are exactly out of phase. That’s kind of what’s happening here though we’re talking about faint sounds that would barely be audible to a human.”

The tail fin movements that reduce sound also generate flow interaction between the fish that allow the fish to swim faster while using less energy, says lead author Ji Zhou, a Johns Hopkins graduate student studying mechanical engineering.

“We find that reduction in flow-generated noise does not have to come at the expense of performance,” Zhou says. “We found cases where significant reductions in noise are accompanied by noticeable increases in per capita thrust, due to the hydrodynamic interactions between the swimmers.”

The team was surprised to find that the sound reduction benefits kick in as soon as one swimming fish joins another. Noise reduction grows as more fish join a school, but the team expects the benefits to cap off at some point.

“Simply being together and swimming in any manner contributes to reducing the sound signature,” Mittal says. “No coordination between the fish is required.”

Next the team plans to add ocean turbulence into the models and create simulations that allow the fish to swim more “freely.”

Source: Johns Hopkins University

New work shows that adding an inexpensive thermal camera to wearable devices could substantially improve how accurately they estimate calories burned.

The estimates of calories burned made by smartphones, smartwatches, and other wearable devices vary wildly. That’s because these devices lack the sensors required to gather all the information they need to make accurate estimates.

Using the thermal camera to monitor a person’s breathing rate and body temperature could reduce inaccuracies in energy expenditure estimates from nearly 40% with a current smartwatch to just under 6%, says Mayank Goel, an associate professor in the Carnegie Mellon University School of Computer Science’s Software and Societal Systems Department (S3D) and Human-Computer Interaction Institute (HCII).

“When people see these numbers, they make changes in their behavior and that can be troublesome if the numbers are wrong,” Goel says. Someone who thinks they just burned 400 calories on the treadmill, for instance, may eat more calories throughout the day, even though their actual expenditure was closer to 200 calories.

“That is a huge problem,” he adds.

Monitoring respiration has been a longtime interest of Goel and his Smart Sensing for Humans (SMASH) Lab, which develops technologies for such applications as health sensing and activity recognition. For instance, he previously developed ways to measure breathing using several methods ranging from wireless router data to custom wearables that analyze chest movements.

While pursuing a different project, Maite Sadeh, a Cornell University information sciences major who was a SMASH Lab summer intern, found reports on how respiration could be measured using a thermal camera to detect exhalations of hot air. Goel’s group then realized that inhalation leads to evaporation around the lips and nostrils. Both of these signals can be captured by a thermal camera.

Rishiraj Adhikary, a PhD student in computer science at IIT Gandhinagar who was also a lab intern via a Fulbright Scholarship, then found studies showing that respiration combined with heart rate could be used to measure energy expenditure.

But respiratory and heart rates aren’t sufficient because they fail to take individual physical and contextual differences into account, Goel says.

The gold standard for clinically measuring energy expenditure is a calorimeter, which uses heart rate, respiration, and the concentration of carbon dioxide in exhaled breaths to determine calories burned. Wearables already do a reasonable job at measuring heart rate and adding a thermal camera would provide a means for measuring respiratory rate. No solution exists for measuring CO2 concentrations with a wearable device, but the thermal camera could measure body temperature.

“We lose the ability to measure the concentration of oxygen and CO2, but we gained temperature measurements,” Goel says.

The combination of those three data points, with help from machine learning, enabled the researchers to develop a system, called JoulesEye, for estimating energy expenditure. They recruited 54 participants who either cycled or ran for 15 minutes. Their tests showed that JoulesEye could estimate burned calories with an error rate of just 5.8% when compared to a clinical calorimeter.

In addition to helping fitness buffs, JoulesEye could be used in sports training, as well as for monitoring people with chronic diabetes or cardiovascular disease.

The cost of incorporating a low-resolution thermal camera into wearable devices should be feasible, as these cameras are already available for $45 or less. But Goel says the team is working to incorporate an even lower-resolution thermal camera into the system, which could lower the price of the sensor. It would also reduce privacy concerns about a camera being routinely pointed at the user’s face.

The team also hopes to reduce the amount of time the thermal camera must be aimed at the user’s face. It now takes about 40 seconds to make the necessary measurements.

“Our goal is that the time it takes to check your watch should be enough time to get the information we need,” Goel says.

A report on JoulesEye, coauthored by Goel, Adhikary, Sadeh, and Nipun Batra, an assistant professor of computer science at the Indian Institute of Technology (IIT) Gandhinagar, appears in the Proceedings of the ACM Mobile, Wearable and Ubiquitous Technologies. The researchers will present their work in October at the UbiComp 2024 conference in Melbourne, Australia.

Source: Carnegie Mellon University