Category: Science

Women who consume higher amounts of protein, especially protein from plant-based sources develop fewer chronic diseases and are more likely to be healthier overall as they age, according to a new study.

Analyzing self-reported data from more than 48,000 women, the researchers saw notably less heart disease, cancer, and diabetes, and cognitive and mental health decline, in those who included more protein in their diets from sources such as fruits, vegetables, bread, beans, legumes, and pasta, compared to those who ate less.

“Consuming protein in midlife was linked to promoting good health in older adulthood,” says Andres Ardisson Korat, a scientist at the Jean Mayer USDA Human Nutrition Research Center on Aging (HNRCA) at Tufts University and lead author of the study. “We also found that the source of protein matters. Getting the majority of your protein from plant sources at midlife, plus a small amount of animal protein seems to be conducive to good health and good survival to older ages.”

Findings were derived from the seminal Harvard-based Nurses’ Health Study, which followed female health care professionals from 1984 to 2016. The women were between the ages of 38 and 59 in 1984 and deemed to be in good physical and mental health at the start of the study.

Ardisson Korat and fellow researchers, including senior author Qi Sun of the Harvard T.H. Chan School of Public Health, examined thousands of surveys collected every four years from 1984 to 2016 on how frequently people ate certain foods to pinpoint dietary protein and its effects on healthy aging. They calculated protein intake by multiplying the number of times each food item was consumed by its protein content and then, using the Harvard University Food Composition Database, totaling the amount of protein across all food items.

The researchers then compared the diets of women who didn’t develop 11 chronic diseases or lose a lot of physical function or mental health, with the diets of those who did. Women who ate more plant-based protein, which in 1984 was defined as protein obtained from bread, vegetables, fruits, pizza, cereal, baked items, mashed potatoes, nuts, beans, peanut butter, and pasta, were 46% more likely to be healthy into their later years. Those who consumed more animal protein such as beef, chicken, milk, fish/seafood, and cheese, however, were 6% less likely to stay healthy as they aged.

“Those who consumed greater amounts of animal protein tended to have more chronic disease and didn’t manage to obtain the improved physical function that we normally associate with eating protein,” says Ardisson Korat.

Animal protein was modestly tied with fewer physical limitations in older age, but plant protein had a stronger, more consistent correlation across all observed models, and was more closely linked with sound mental health later in life. For heart disease in particular, higher plant protein consumption came with lower levels of LDL cholesterol (“bad” cholesterol), blood pressure, and insulin sensitivity, while higher animal protein intake was tied to higher levels, along with increased insulin-like growth factor, which has been detected in multiple cancers.

Dairy protein alone (mainly milk, cheese, pizza, yogurt, and ice cream) was not significantly associated with better health status in older adulthood.

The team acknowledges that the benefits of plant protein might derive from components in plant-based food, rather than the protein—compared to animal foods, plants contain a higher proportion of dietary fiber, micronutrients, and beneficial compounds called polyphenols that are present in plants, rather than exclusively protein.

Ardisson Korat also says data from other groups is needed, as the Nurses’ Health Study surveyed primarily white females working in health care.

“The data from the study tended to be very homogeneous in terms of demographic and socioeconomic composition, so it will be valuable to follow up with a study in cohorts that are more diverse. It’s a field that is still evolving,” says Ardisson Korat.

But the team’s findings so far support the recommendation that women eat most of their protein in the form of fruits, vegetables, nuts, and seeds, although they should also consume some fish and animal protein for their iron and vitamin B12 content.

“Dietary protein intake, especially plant protein, in midlife plays an important role in the promotion of healthy aging and in maintaining positive health status at older ages,” Ardisson Korat says.

The research appears in The American Journal of Clinical Nutrition.

Source: Tufts University

WASHINGTON — Astroscale is developing an in-space refueling vehicle that will shuttle back and forth between a fuel depot in geostationary Earth orbit and a client satellite. 

The refueling vehicle will carry and transfer hydrazine to its client spacecraft, “rather than the client having to maneuver to a fuel depot, allowing client operations to continue uninterrupted,” the company said Jan. 17.

Astroscale, headquartered in Japan with a U.S. subsidiary based in Colorado, is a provider of space services to extend the life of satellites. The company last year won a $25.5 million contract from the U.S. Space Force to develop a refueling vehicle. Under the private-public partnership agreement, the project will get an additional $12 million in funding from Astroscale and its suppliers. 

Named APS-R, for Astroscale Prototype Servicer for Refueling, the vehicle will be a small satellite about the size of a gas pump, designed to conduct multiple refueling missions in GEO. 

APS-R will rendezvous and dock with a fuel depot operated by Orbit Fab, a startup developing so-called gas stations in space. The company is working on a hydrazine fueling station to be deployed 36,000 kilometers above Earth, partly funded by a $13.3 million contract from the Pentagon’s Defense Innovation Unit.

The client satellite receiving fuel will be Astroscale’s Life Extension In-Orbit (LEXI), designed to perform life extension services in geostationary orbit. Astroscale two years ago announced plans to launch LEXI in 2026 and signed an agreement with Orbit Fab for refueling services.

In its Jan. 17 announcement, Astroscale said it plans to deliver the APS-R by 2026. 

Satellite to be manufactured in Texas

The refueler will be an ESPA-class satellite, a ring-shaped platform that attaches to the primary payload on a launch vehicle. ESPA is short for Evolved Expendable Launch Vehicle Secondary Payload Adapter. 

Astroscale envisions deploying the LEXI client vehicle in a GEO orbit about 300 kilometers below Orbit Fab’s orbiting fuel depot. 

APS-R will be manufactured at the Southwest Research Institute’s new smallsat assembly facility in San Antonio, Texas. Both the APS-R and LEXI will use Orbit Fab’s refueling ports to ensure they can dock properly.

“This innovation in on-orbit servicing will ultimately extend the range and mobility of satellites in orbit, allowing the U.S. Space Force to do more with their operational assets,” said Ron Lopez, president and managing director of Astroscale U.S.

Col. Joyce Bulson, leader of the Space Force’s space mobility and logistics program, said the collaboration with Astroscale “signifies a bold step forward in our efforts to secure and strengthen the U.S. Space Force’s position in an ever-evolving space domain, reinforcing our commitment to innovation and ensuring the sustainability of our space assets.”

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A modified soft material promises better bioelectronics, researchers report.

The scientific community has long been enamored of the potential for soft bioelectronic devices. But they’ve faced hurdles in identifying materials that are biocompatible and have all of the necessary characteristics to operate effectively.

The new research is a step in the right direction.

Researchers have modified an existing biocompatible material so that it conducts electricity efficiently in wet environments and can send and receive ionic signals from biological media.

“We’re talking about an order-of-magnitude improvement in the ability of soft bioelectronic materials to function efficiently in biological environments,” says Aram Amassian, co-corresponding author of a paper on the work and a professor of materials science and engineering at North Carolina State University. “This is not an incremental advance.”

There is tremendous interest in creating organic bioelectronics and organic electrochemical transistors (OECTs), with a wide range of biomedical applications. However, one limiting factor is identifying nontoxic materials that can conduct electricity, interacting with ions—which is critical to functioning in biological environments, and operating efficiently in the aqueous, water-based environments of biological systems.

One material of interest has been PEDOT:PSS, which is a nontoxic polymer that is able to conduct electricity. PEDOT:PSS is used to create thin films which are effectively fiber networks that are only nanometers wide. Electrical current can run through the fibers, which are also sensitive to ions in their environment.

“The idea is that, because ions interact with the fibers—and affect their conductivity—PEDOT:PSS can be used to sense what is happening around the fibers,” says Laine Taussig, co-first author of the paper and a recent PhD graduate of NC State who now works at the Air Force Research laboratory.

“Essentially, PEDOT:PSS would be able to monitor its biological environment. But we could also use the electric current to influence the ions surrounding the PEDOT:PSS, sending signals to that biological environment,” says Masoud Ghasemi, co-first author and a former postdoctoral fellow at NC State who is now a postdoctoral fellow at Penn State.

However, PEDOT:PSS’s structural stability declines significantly when placed in aqueous environments—like biological systems. That’s because PEDOT:PSS is a single material made from two components: the PEDOT, which conducts electricity and is not soluble in water; and PSS, which responds to ions, but is water soluble. In other words, the PSS makes the material start to fall apart when it comes into contact with water.

Previous efforts to stabilize the structure of PEDOT:PSS have been able to help the material withstand aqueous environments, but have both hurt PEDOT:PSS’s performance as a conductor and made it more difficult for ions to interact with the material’s PSS components.

“Our work here is important, because we’ve found a new way to make a PEDOT:PSS that is structurally stable in wet environments and able to both interact with ions and conduct electricity very efficiently,” says George Malliaras, co-corresponding author and a professor of technology at Cambridge University.

Specifically, the researchers start with PEDOT:PSS in solution and then add ionic salts. Given time, the ionic salts interact with the PEDOT:PSS, causing it to self-assemble into fibers with a unique structure that remains stable in wet environments. This modified PEDOT:PSS is then dried and the ionic salts rinsed off.

“We already knew that ionic salts could affect PEDOT:PSS,” Amassian says. “What’s new here is that by giving the ionic salts more time to see the full extent of those effects, we modified the crystalline structures of the PEDOT and the PSS to essentially lace themselves together at the molecular scale. This makes the PSS impervious to the water in the environment, allowing the PEDOT:PSS to maintain its structural stability at the molecular level.”

“The change is also hierarchical, meaning that there are shifts at the molecular level all the way up to macroscale,” says Yaroslava Yingling, coauthor of the paper and a professor of materials science and engineering at NC State. “The ionic salts cause the PEDOT:PSS to essentially reorganize itself into a phase that resembles a web-like gel that is preserved in both dry and wet environments.”

In addition to being stable in aqueous environments, the resulting films retain their conductivity. What’s more, because the PEDOT and PSS are tightly interwoven, it’s easy for ions to reach and interact with the PSS component of the material.

“This new phase of PEDOT:PSS was used to create OECTs by our collaborators at Cambridge,” Amassian says. “And those OECTs set a new state-of-the-art standard in both volumetric capacitance and electronic carrier mobility. In other words, it’s the new gold standard in both conductivity and ion responsiveness in bio-friendly electronics.

“Given that PEDOT:PSS is transparent, flexible, stretchable, conductive, and biocompatible, the range of potential applications is exciting—extending well beyond the biomedical sector,” says Enrique Gomez, co-corresponding author and a professor at Penn State.

The paper appears in the journal Matter.

Additional coauthors are from  NC State, Cambridge, and Brookhaven National Laboratory.

Support for the work came from the Office of Naval Research.

Source: NC State

WASHINGTON — Impulse Space, which launched its first orbital transfer vehicle last year, has unveiled plans for a larger vehicle for transporting satellites to geostationary and other orbits.

The company, based in Redondo Beach, California, announced Jan. 17 it is working on Helios, a kick stage using an engine fueled by liquid oxygen and methane propellants. Helios can serve as a transfer stage for transporting satellites weighing up to about 5,000 kilograms from low Earth orbit to geostationary orbit in less than a day.

Tom Mueller, chief executive of Impulse Space and one of the founding employees of SpaceX, said Helios wants to extend the capabilities of vehicles like SpaceX’s Falcon 9 to higher orbits. “SpaceX really got the party started by opening up access to LEO,” he said in an interview. “What Impulse wants to do is what SpaceX did for LEO, but for everything else, all the other high-energy orbits.”

Helios would serve as an additional stage for the Falcon 9. “It’s sized to max out the capability of a Falcon 9,” transporting satellites to GEO in less than 24 hours. “It’s basically giving you two-thirds of the capability of a [Falcon] Heavy without having to throw away a core and for much less money.”

The stage will be powered by an engine called Deneb, producing 15,000 pounds-force of thrust. Mueller said the engine components have passed a preliminary design review, and the company is on track to begin engine tests in the summer.

The first flight of Helios is planned for early 2026, with initial plans to fly the vehicle four to six times a year. Impulse has a letter of intent with an undisclosed customer and positive conversations with other potential users, he said: “This is the right product at the right time.”

Martin Halliwell, former chief technology officer of satellite operator SES and an adviser to Impulse, said in a statement that the ability to get to GEO in hours, rather than weeks or months, “changes the mission value proposition significantly” for satellite customers, allowing their satellites to enter service faster while reducing radiation exposure and payload mass. “Helios will open new opportunities for MEO and GEO operators beyond today’s limited mission choice criteria,” he said.

Helios is designed to be compatible with a wide range of launch vehicles. “Any medium-sized vehicle that could carry this would greatly improve its performance,” Mueller said. “Even on a vehicle that has awesome performance, like Vulcan, this will increase its capabilities.”

Impulse sees Helios as complementary to Mira, a smaller transfer vehicle it launched for the first time last November on SpaceX’s Transporter-9 rideshare mission. That vehicle, flying a mission called LEO Expess-1, successfully deployed a cubesat and is testing its thrusters.

“Now we’re getting ready to do longer burns and some big orbital changes,” Mueller said. The vehicle already has performed one maneuver to avoid a close approach with what he described as a defunct cubesat.

He said the company plans to keep flying Mira, with a second LEO Express mission planned for October. The interest in Mira comes from both customers looking for some ability to modify their orbits as well as others interested in hosted payloads, such as qualifying components.

The company, with nearly 100 employees, raised $45 million in a Series A round in July 2023. Mueller said the company was now working on a Series B round to support work on Helios. “We’ll need just one more round to get to profitability with this vehicle and with the Mira business that we have,” he said.

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WASHINGTON — SpaceX launched Axiom Space’s third private astronaut mission Jan. 18, sending a veteran former NASA astronaut and three astronauts from European governments to the International Space Station.

A Falcon 9 lifted off at 4:49 p.m. Eastern from Launch Complex 39A at the Kennedy Space Center in Florida and placed the Crew Dragon spacecraft Freedom into orbit. Freedom separated from the upper stage about 12 minutes after liftoff.

The launch had been scheduled for Jan. 17 but was delayed less than six hours before the scheduled liftoff when SpaceX announced it would take an additional day “to complete pre-launch checkouts and data analysis on the vehicle.”

SpaceX did not offer specifics on the delay, but both Axiom Space and NASA later said the delay was to provide more time to review parachute straps known as energy modulators in the Crew Dragon. SpaceX said in a Jan. 16 prelaunch briefing that they found issues with those straps, intended to regulate the load on the main parachutes when extracted from the capsule, during the return of the CRS-29 cargo Dragon mission in December. SpaceX said that may have been caused by twists in the straps, and technicians untwisted the energy modulators in the parachutes on this Crew Dragon before launch.

The spacecraft is scheduled to dock with the ISS Jan. 20 at 4:19 a.m. Eastern. It will remain docked to the station for about two weeks before returning to Earth with its four-person crew.

The Ax-3 mission is the third such mission organized by Axiom Space, which is using them to gain experience in spaceflight operations as it prepares to install commercial modules on the station that will later form the core of a standalone commercial space station upon the retirement of the ISS. Axiom flew Ax-1 in April 2022 and Ax-2 in May 2023.

Ax-3 is commanded by former NASA astronaut Michael López-Alegría, who also commanded Ax-1. It is the sixth flight for López-Alegría, who flew on three shuttle missions and one long-duration ISS mission while with NASA.

The other three members of the crew represent European governments. The pilot of Ax-3 is Walter Villadei, an Italian Air Force officer who trained as the backup pilot for Ax-2 and flew on Virgin Galactic’s first commercial flight of its VSS Unity suborbital spaceplane in June 2023.

The two mission specialists on Ax-3 are Alper Gezeravcı of Turkey and Marcus Wandt of Sweden. Gezeravcı is a pilot in the Turkish Air Force and is the first person from that country to fly to space. Wandt, a former Swedish Air Force pilot, is the second Swede to fly to space.

Wandt was selected a reserve astronaut by the European Space Agency in November 2022 and is the first person from that class to go to space. ESA and the Swedish space agency arranged for his flight as ESA’s first short-term “project” astronaut. A second project astronaut, Poland’s Sławosz Uznański, is expected to go the ISS as soon as later this year, also through Axiom Space.

Those missions are different from long-duration ISS missions and future Artemis missions flown by ESA’s permanent astronaut corps. “It’s a fixed-term contract he has with the agency, while career astronauts have permanent contracts,” said Daniel Neuenschwander, ESA’s director of human and robotic exploration, of Wandt during a Jan. 11 media briefing. ESA’s five new career astronauts will complete their training in April and some could be assigned to their first ISS missions as soon as May.

Derek Hassmann, chief of mission integration and operations at Axiom Space, said at the Jan. 16 prelaunch briefing that Axiom plans to continue flying short-duration private astronaut missions to the ISS at a pace of two a year through the launch of its first commercial module, now planned for late 2026. Ax-4 is tentatively planned for launch in the fall of 2024, but neither Axiom nor NASA have announced firm plans for missions beyond Ax-4.

NASA is supporting private astronaut missions as part of its broader strategy to stimulate development of commercial space stations intended to succeed the ISS when it is retired at the end of the decade. NASA awarded a contract to Axiom in 2020 giving it access to a docking port on the station for its commercial modules and has funded Space Act Agreements with Blue Origin and Voyager Space to support work on those companies’ station concepts.

“I am certainly hopeful that they are going to be successful,” said NASA Administrator Bill Nelson of private space station ventures on Axiom’s webcast of the Ax-3 launch. NASA, he noted, is counting on one or more commercial stations to be successful to support NASA’s needs as well as other customers, so that NASA can focus on its lunar and Mars exploration ambitions.

Ax-3 featured the third flight of Freedom and the fifth of the Falcon 9 booster. Benji Reed, senior director of human spaceflight programs at SpaceX, said at the prelaunch briefing that while SpaceX plans to be able to fly Dragon spacecraft up to 15 times each, it is currently only using Falcon 9 boosters on crewed missions that have flown no more than five times, even as SpaceX pushes to extend the lives of those boosters to up to 40 missions.

“When we feel comfortable expanding that envelope as well, we’ll continue to work that with all of our customers,” he said of booster reuse on crewed flights.

After the Crew Dragon reached orbit, Bill Gerstenmaier, SpaceX’s vice president of build and flight reliability who is also chief engineer for the mission, called the crew. “I think you’re demonstrating the ultimate in reuse: a reused commander, a reused Dragon and a reused Falcon,” he said. “Or maybe ‘flight-experienced’ is a better word.”

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With human retinas grown in a petri dish, researchers have discovered how humans generate the specialized cells that enable us to see millions of colors, an ability that dogs, cats, and other mammals do not possess.

“These retinal organoids allowed us for the first time to study this very human-specific trait,” says author Robert Johnston, an associate professor of biology at Johns Hopkins University. “It’s a huge question about what makes us human, what makes us different.”

The findings, published in PLOS Biology, increase understanding of color blindness, age-related vision loss, and other diseases linked to photoreceptor cells. They also demonstrate how genes instruct the human retina to make specific color-sensing cells, a process scientists thought was controlled by thyroid hormones.

By tweaking the cellular properties of the organoids, the researchers found that a molecule derived from vitamin A called retinoic acid determines whether a cone will specialize in sensing red or green light. Only humans with normal vision and closely related primates develop the red sensor.

Scientists for decades thought red cones formed through a coin toss mechanism where the cells haphazardly commit to sensing green or red wavelengths—and research from Johnston’s team recently hinted that the process could be controlled by thyroid hormone levels.

Instead, the new findings suggest red cones materialize through a specific sequence of events orchestrated by retinoic acid within the eye.

The team found that high levels of retinoic acid in early development of the organoids correlated with higher ratios of green cones. Similarly, low levels of the acid changed the retina’s genetic instructions and generated red cones later in development.

“There still might be some randomness to it, but our big finding is that you make retinoic acid early in development,” Johnston says. “This timing really matters for learning and understanding how these cone cells are made.”

Green and red cone cells are remarkably similar except for a protein called opsin, which detects light and tells the brain what colors people see. Different opsins determine whether a cone will become a green or a red sensor, though the genes of each sensor remain 96% identical. With a breakthrough technique that spotted those subtle genetic differences in the organoids, the team tracked cone ratio changes over 200 days.

“Because we can control in organoids the population of green and red cells, we can kind of push the pool to be more green or more red,” says author Sarah Hadyniak, who conducted the research as a doctoral student in Johnston’s lab and is now at Duke University. “That has implications for figuring out exactly how retinoic acid is acting on genes.”

The researchers also mapped the widely varying ratios of these cells in the retinas of 700 adults. Seeing how the green and red cone proportions changed in humans was one of the most surprising findings of the new research, Hadyniak says.

Scientists still don’t fully understand how the ratio of green and red cones can vary so greatly without affecting someone’s vision. If these types of cells determined the length of a human arm, the different ratios would produce “amazingly different” arm lengths, Johnston says.

To build understanding of diseases like macular degeneration, which causes loss of light-sensing cells near the center of the retina, the researchers are working with other Johns Hopkins labs. The goal is to deepen their understanding of how cones and other cells link to the nervous system.

“The future hope is to help people with these vision problems,” Johnston says. “It’s going to be a little while before that happens, but just knowing that we can make these different cell types is very, very promising.”

Additional coauthors are from Johns Hopkins and the University of Washington.

Source: Johns Hopkins University

Splitting your workouts into half-cardio and half-strength training reduces cardiovascular disease risks, new research suggests.

Approximately one in three deaths in the US is caused by cardiovascular disease, according to the US Centers for Disease Control and Prevention.

A robust body of evidence shows aerobic exercise can reduce risks, especially for people who are overweight or obese.

But few studies have compared results with resistance exercise—also known as strength or weight training—or with workout regimens that are half aerobic and half resistance. The new research—one of the longest and largest supervised exercise trials—helps fill this gap.

The results, which appear in European Heart Journal, indicate that splitting the recommended amount of physical activity between aerobic and resistance exercise reduces cardiovascular disease risks as much as aerobic-only regimens.

Resistance exercise on its own for the same amount of time did not provide the same heart health benefits when compared to the control group.

“If you’re bored with aerobic exercise and want variety or you have joint pain that makes running long distances difficult, our study shows you can replace half of your aerobic workout with strength training to get the same cardiovascular benefits. The combined workout also offers some other unique health benefits, like improving your muscles,” says Duck-chul Lee, lead author and professor of kinesiology at Iowa State.

Performing a certain number of sets and repetitions with weight machines, free weights, elastic bands, or your own body weight through push-ups or lunges, all fall under resistance exercise.

“One of the most common reasons why people don’t exercise is because they have limited time. The combined exercise with both cardio and strength training we’re suggesting is not more time consuming,” Lee underscores.

In the paper, the researchers write: “These findings may help develop clinical and public health practices and recommendations for the approximately 2 billion adults with overweight or obesity worldwide who are at increased risk of [cardiovascular disease.]”

How the study worked

Four hundred and six participants between 35 and 70 years of age enrolled in the one-year randomized controlled exercise trial. All met the threshold for being overweight or obese with body mass indexes between 25-40 kg/m² and had elevated blood pressure.

The researchers randomly assigned participants to one of four groups: no exercise, aerobic only, resistance only, or aerobic plus resistance. Those who were in one of the three exercise groups worked out under supervision for one hour, three times a week for one year.

Every participant in one of the exercise groups received a tailored workout routine based on their individual fitness levels, health conditions, and progression. Those assigned to resistance training were given a certain number of sets, repetitions and weights for weight-lifting machines. With aerobic exercises, participants wore a heart rate monitor and inserted a unique exercise program key into a treadmill or stationary bike. Sensing the participant’s heart rate, the machine automatically adjusted the speed and grade to match the prescribed intensity.

The researchers collected physical activity and diet data outside the lab, as well. All participants, including those in the no exercise group, wore pedometers to measure daily steps. They met every three months with registered dietitians at Iowa State for “Dietary Approaches to Stop Hypertension” education, which is promoted by the National Institutes of Health. On three random days per month, participants were asked to record what they had consumed in the last 24 hours with an online dietary assessment tool developed by the US National Cancer Institute.

At the start of the year-long clinical trial, six months in and at the end, the researchers measured each participant’s systolic blood pressure, low-density lipoprotein cholesterol, fasting glucose, and body fat percentage. All are well-established cardiovascular disease risk factors.

“Many previous studies only looked at one of these four factors, but it’s really multiple factors combined that increase cardiovascular disease risk,” explains Lee.

The researchers used a composite score to fairly quantify changes across all four factors since each uses a different unit of measurement. A lower composite score indicates less risk for developing cardiovascular disease.

What researchers found

At the end of the year-long trial, the percentage of body fat in all three exercise groups had decreased significantly compared to the no-exercise control group. The authors write in the paper that “every -1% body fat reduction is associated with -3%, -4%, and -8% lower risks of developing [cardiovascular disease] risk factors of hypertension, hypercholesterolemia, and metabolic syndrome.”

However, taking all four cardiovascular disease risk factors into account, the aerobic and combined exercise groups had lower composite scores than the control group. The results were consistent across gender and age.

Over the course of the 12-month study, those in the aerobic-only group continued to improve with the VO₂max test, which is the maximum rate of oxygen consumption attainable during a maximal treadmill test. The resistance-only group stayed relatively flat. The inverse was true for the maximal bench and leg press tests for muscular strength; the resistance-only group continued to improve while the aerobic-only group did not.

However, the combination exercise group improved both aerobic fitness and muscular strength.

Looking ahead

The authors say their findings support “physical activity guidelines recommending both resistance and aerobic exercise by the US, [World Health Organization], and European Society of Cardiology, specifically for individuals with obesity.” Currently, it’s at least 150 minutes each week of moderate intensity aerobic exercise and two sessions per week of resistance training.

“But these guidelines don’t specify how long those strength training sessions should be to get the health benefits,” says Lee.

Lee wants to find “the right dose” of resistance exercise among adults who are overweight or obese. He plans to conduct another randomized controlled resistance exercise trial, this time with 240 participants. The study will compare results from 0-, 15-, 30-, and 60-minute resistance sessions, twice per week for six months in a supervised exercise lab. Participants in all four groups also will be asked to do 30-minute sessions of moderate intensity aerobic exercise, twice per week, per the physical activity guidelines.

During the second six-month phase, participants will receive a free health club membership and be asked to continue their assigned regimen, unsupervised. Lee explains this will help identify which dose of resistance exercise is both effective and feasible outside experimental trials.

Additional coauthors are from Iowa State and the University of California Riverside.

Source: Iowa State University

Researchers have identified previously unknown changes in brain cells affected by a rare neurological disease.

Their research in eLife could pave the way to future treatments for the disease.

Spinocerebellar ataxia type 6, known as SCA6, is a rare neurological disease that disrupts the function in a part of the brain called the cerebellum, causing difficulties with movement and coordination.

The condition results from genetic mutations, with symptoms starting in adulthood and worsening over time, and currently has no cure.

While scientists have long known that SCA6 is characterized by changes in the cerebellum, the part of the brain that regulates motor movement and balance, the precise mechanisms of these changes and how they might contribute to the onset and progression of SCA6 are not fully understood.

The study looked at mouse models for SCA6, mice that were genetically modified with the same mutations as human SCA6 patients, and which exhibited movement problems consistent with the disease. Tissue samples from the SCA mice revealed striking and never-before-observed abnormalities in their cells’ endosomal systems.

“Cells are busy places, with lots of things going on, and it is therefore crucial for cells to transport proteins and molecules to the right place at the right time,” explains Anna Cook, a former McGill University PhD researcher who is the first author of the study. “But in SCA6 this system goes wrong. Just like cars can get stuck in traffic, proteins and molecules can get held up in the transport machinery within certain cells.”

To see if the endosomal deficits could be corrected, the researchers tested a drug called 7,8-DHF and found that the compound corrected for the cellular abnormalities, enabling the misplaced proteins to get to where they needed to go.

“This drug is effectively acting as a traffic cop,” Watt says. “It gets the traffic moving again, allowing key signaling molecules to get to the cellular locations where they are needed to work.”

“Since there is currently no cure for SCA6, new information about the pathological changes in the disease is vital to help develop new drugs and treatments,” Cook says.

“This preclinical research is exciting not only because it sheds light on some of the fundamental mechanisms of this disease, but also because it points to an aspect of the disease that we have shown can be targeted therapeutically.”

The Watt lab continues to build on this work to identify disease mechanisms and potential treatments for SCA6 and other cerebellar diseases.

Anna Cook is now a postdoctoral researcher at the University of Oxford, studying dopamine signaling in healthy and disease-affected brains.

Source: McGill University

Most people with chronic pain say they would alter their behavior based on a weather-based pain forecast.

For individuals who experience chronic pain, weather can be a significant factor in their day-to-day plans.

“We’re finding more consistent relationships between weather patterns and pain, so it seems more possible to make weather-based pain forecasts,” says lead author Christopher Elcik, a geography/atmospheric sciences lecturer at the University of Georgia. “This study was to survey and see what the audience was for this type of forecast.”

The study surveyed more than 4,600 individuals. Among migraine sufferers, 89% identified weather as something that affects their pain level, and 79% saw weather as a trigger for pain. Among individuals with other conditions, 64% says weather patterns could trigger pain and 94% identified weather as a factor that affects pain.

Elcik built on previous research regarding specific weather patterns and pain-related conditions to gauge public interest in a weather-based pain forecast, which could indicate high or moderate risk for migraines or chronic pain.

“I see how much people can be affected by these types of pain, so if I can provide someone with insight into the level of risk for a day, maybe people can take steps to prevent the pain from happening,” Elcik says. “There are preventative measures people can take if risks are higher.”

If the hypothetical risk was high, more than half of respondents said they were likely to take preventive measures, such as medication, resting, or avoiding compounding triggers, and about 47% of respondents with migraines and 46% with pain-related conditions were “extremely likely” to take such measures.

Desire for a forecasting tool was quite high, Elcik says, with 72% of those living with migraine and 66% with pain-related conditions saying they would alter their behavior by canceling plans or taking preventive measures in response to a weather-based pain forecast.

Some respondents reported already using web-based tools, such as AccuWeather’s arthritis or migraine forecast, which predicts low-to-high risk according to atmospheric conditions. With existing tools, however, there is little available information about the variables considered or how the predictions are made.

The likelihood someone would continue with plans also depended on the length of the activity. If plans were about 30 minutes long, 57% of respondents with migraines and 52% with pain-related conditions said they were “extremely likely” to continue plans despite a moderate risk of pain, and about 43% from each group would continue with a highest risk forecast.

With an activity lasting more than three hours, however, that number dropped to around 23% for moderate risk and 18% for high risk with migraines and 21% or 23%, respectively, for other pain-related conditions. As level for risk increased, so did the likelihood to alter plans.

“This was across the board,” Elcik says. “Everyone was more likely to cancel plans if the forecast risk was higher.”

While additional research and studies are needed to create a reliable pain-based weather forecast, Elcik says this study highlights the importance of developing such a resource.

“This publication shows there’s an audience that’s willing and eager to try something new, and there are probably many more people who would benefit—more than we even thought,” he says. “I think these results can push other researchers to also look at similar, larger-scale weather phenomena and help the community better understand how the atmosphere does impact pain.”

Source: University of Georgia

While it is well known that cannabis can cause the munchies, researchers have now revealed a mechanism in the brain that promotes appetite in a set of animal studies.

The discovery, detailed in the journal Scientific Reports, could pave the way for refined therapeutics to treat appetite disorders faced by cancer patients as well as anorexia and potentially obesity.

After exposing mice to vaporized cannabis sativa, researchers used calcium imaging technology, which is similar to a brain MRI, to determine how their brain cells responded. They observed that cannabis activated a set of cells in the hypothalamus when the rodents anticipated and consumed palatable food that were not activated in unexposed mice.

“When the mice are given cannabis, neurons come on that typically are not active,” says Jon Davis, an assistant professor of neuroscience at Washington State University and corresponding author on the paper. “There is something important happening in the hypothalamus after vapor cannabis.”

Calcium imaging has been used to study the brain’s reactions to food by other researchers, but this is the first known study to use it to understand those features following cannabis exposure.

As part of this research, the researchers also determined that the cannabinoid-1 receptor, a known cannabis target, controlled the activity of a well-known set of “feeding” cells in the hypothalamus, called Agouti Related Protein neurons.

With this information, they used a “chemogenetic” technique, which acts like a molecular light switch, to home in on these neurons when animals were exposed to cannabis. When these neurons were turned off, cannabis no longer promoted appetite.

“We now know one of the ways that the brain responds to recreational-type cannabis to promote appetite,” says Davis.

This work builds on previous research on cannabis and appetite from Davis’ lab, which was among the first to use whole vaporized cannabis plant matter in animal studies instead of injected THC—in an effort to better mimic how cannabis is used by humans. In the previous work, the researchers identified genetic changes in the hypothalamus in response to cannabis, so in this study, Davis and his colleagues focused on that area.

The current research received support from the Alcohol and Drug Abuse Research Program, the National Institute on Alcohol Abuse and Alcoholism, and the US Department of Agriculture, as well as by funds provided by the state of Washington Initiative Measure No. 171.

Source: Washington State University