Category: Science

Research shows that remembering events can trigger rhythmic patterns of electrical activity in the brain called oscillations— even more so than when people are experiencing the actual event.

One of the unsettled questions in the field of neuroscience is what primarily drives these rhythmic signals.

The researchers, whose findings appear in the journal Neuron, specifically focused on what are known as theta oscillations, which emerge in the brain’s hippocampus region during activities like exploration, navigation, and sleep. The hippocampus plays a crucial role in the brain’s ability to remember the past.

Prior to this study, it was believed that the external environment played a more important role in driving theta oscillations, says Arne Ekstrom, professor of cognition and neural systems in the University of Arizona psychology department and senior author of the study. But Ekstrom and his collaborators found that memory generated in the brain is the main driver of theta activity.

“Surprisingly, we found that theta oscillations in humans are more prevalent when someone is just remembering things, compared to experiencing events directly,” says lead study author Sarah Seger, a graduate student in the neuroscience department.

The results of the study could have implications for treating patients with brain damage and cognitive impairments, including patients who have experienced seizures, stroke, and Parkinson’s disease, Ekstrom says. Memory could be used to create stimulations from within the brain and drive theta oscillations, which could potentially lead to improvements in memory over time, he says.

The researchers recruited 13 patients who were being monitored at the center in preparation for epilepsy surgery. As part of the monitoring, electrodes were implanted in the patients’ brains for detecting occasional seizures. The researchers recorded the theta oscillations in the hippocampus of the brain.

The patients participated in a virtual reality experiment, in which they were given a joystick to navigate to shops in a virtual city on a computer. When they arrived at the correct destination, the virtual reality experiment was paused. The researchers asked the participants to imagine the location at which they started their navigation and instructed them to mentally navigate the route they just passed through. The researchers then compared theta oscillations during initial navigation to participants’ subsequent recollection of the route.

During the actual navigation process using the joystick, the oscillations were less frequent and shorter in duration compared to oscillations that occurred when participants were just imagining the route. So, the researchers conclude that memory is a strong driver of theta oscillations in humans.

One way to compensate for impaired cognitive function is by using cognitive training and rehabilitation, Ekstrom says. “Basically, you take a patient who has memory impairments, and you try to teach them to be better at memory.”

In the future, Ekstrom is planning to conduct this research in freely walking patients as opposed to patients in beds and find how freely navigating compares to memory with regard to brain oscillations.

“Being able to directly compare the oscillations that were present during the original experience, and during a later retrieval of that is a huge step forward in the field in terms of designing new experiments and understanding the neural basis of memory,” says Seger.

Coauthors of the study are from the University of Texas Southwestern Medical Center in Dallas.

Source: University of Arizona

SEATTLE — Even as Virgin Galactic enters regular commercial operations of its suborbital spaceplane, it is advising that those flights will generate only modest revenues for the near future.

Virgin Galactic reported Aug. 1 revenue of $2 million in the second quarter of 2023. The company said that the revenue came from its first commercial SpaceShipTwo mission, “Galactic 01,” on June 29, as well as membership fees from its private astronaut customers.

Galactic 01, a research flight for the Italian Air Force, marked the long-awaited start of commercial operations of the company’s VSS Unity vehicle. Virgin Galactic plans to fly Unity on roughly a monthly cadence.

The vehicle’s next mission, Galactic 02, is scheduled for Aug. 10 from Spaceport America in New Mexico. The flight will be the first to carry the company’s private astronaut customers. Virgin Galactic announced July 17 that flight will include Jon Goodwin, Keisha Schahaff and Anastatia Mayers. Goodwin was one of the company’s early customers while Schahaff and Mayers won a 2021 contest for seats on an early SpaceShipTwo flight.

“Galactic 02 is going to set the stage for a new era of suborbital human spaceflight that will dramatically broaden access to space for private individuals,” Michael Colglazier, chief executive of Virgin Galactic, said in an earnings call.

However, while the company played up the significance of Galactic 02, it is downplaying the revenue that and future flights will generate for Virgin Galactic. The company is forecasting just $1 million in revenue in each of the next two quarters.

Part of the reason for that, Colglazier said, is that about three-fourths of the 800 tickets sold so far were at prices of between $200,000 and $250,000 each. The company later raised prices to $450,000 each. In addition, while Unity’s cabin can accommodate four people, the company plans to fly only three paying customers on each flight initially, using the fourth seat for an astronaut trainer. In the case of Galactic 02, that is Beth Moses, the company’s chief astronaut instructor.

“When we look at the capacity of Unity and the ticket prices that we’re flying these days, you would expect to see for the near term about $600,000 per flight,” he said. He said the company expects to add a fourth paying customer to Unity flights “as we move into 2024,” increasing the per-flight revenue to about $800,000.

Research flights like Galactic 01 are more lucrative. Colglazier estimated those flights generate about $600,000 per seat equivalent. The company, though, has reserved only about 100 of its first 1,000 seats for research customers.

Virgin Galactic has largely stopped ticket sales for the time being other than those it is offering through a travel agency, Virtuoso, to manage its customer backlog. Colglazier said the company will sell new tranches of tickets as it gets closer to the introduction of its Delta class of next-generation spaceplanes, currently planned for 2026. Virgin has not set ticket pricing for those future sales, but he said “we don’t expect that to be less” than the current price of $450,000.

Colglazier also strongly suggested in the call that Virgin Galactic does not expect to fly VSS Imagine, a second suborbital spaceplane that the company had been developing. Virgin had deferred work on Imagine to prioritize company resources around both getting Unity into commercial service and development of the Delta class of vehicles.

“We’ve kind of kept it as an option for us, and it’s going to remain as an option for us,” he said of Imagine, but indicated it would likely be used to support Delta-class development versus flying commercial missions. “It’s still here with us, and we have it secured and ready. But it’s likely going to be used in service of the Delta program.”

The company reported a net loss of $134.4 million in the second quarter as it continues spending on Delta-class development. However, the company raised $241 million in a sale of stock in the quarter, giving the company $980 million in cash and equivalents on hand as of the end of the second quarter.

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There are substantial gaps in the American public’s knowledge of maternal health, according to new survey data.

The findings come amid a maternal health crisis in the US, which has the highest maternal mortality rate of any developed nation, more than double the rate of peer countries, according to the US Department of Health and Human Services.

In addition, the survey, conducted nearly a year after the federal government introduced the new 988 Suicide and Crisis Lifeline, finds that just 10% of the public knows the number.

“The Suicide Lifeline’s ability to save lives presupposes that those in need know the 988 number,” says APPC director Kathleen Hall Jamieson, who directs the survey for the Annenberg Public Policy Center (APPC) of the University of Pennsylvania. “We need to redouble our efforts to add 988 to the numbers everyone has at hand.”

The survey, conducted with a nationally representative panel of 1,601 US adults from May 31-June 6, 2023, finds:

• Just over 1 in 4 people (27%) know that the CDC recommends that pregnant individuals get a Tdap vaccine against whooping cough.
• Just over half of those surveyed know that getting vaccinated against COVID-19 during pregnancy is safe (52%) and that getting vaccinated against COVID-19 can reduce the risk of complications from the disease (55%) that can affect a pregnancy.
• Only a quarter of those surveyed (26%) know that a pregnant person who gets the flu is at higher risk of delivering the baby early.
• Nearly 3 in 4 people (73%) know that having untreated high blood pressure increases the likelihood that a pregnant person will have a stroke.

Asked which vaccinations the CDC recommends individuals get during pregnancy, majorities know that the CDC does not recommend a chickenpox or measles vaccine, which are live virus vaccines.

• 87% know that the CDC does not recommend the chickenpox vaccine
• 85% know that the CDC does not recommend a measles shot
• But 73% incorrectly said the CDC does not recommend a vaccine for whooping cough known as Tdap during pregnancy. In fact, the CDC does recommend the whooping cough vaccine during pregnancy, as 27% know.

Both the Tdap vaccine against whooping cough and the flu shot are inactivated vaccines and are recommended by the CDC during each pregnancy. During pregnancy, the CDC recommends the flu shot, not the live attenuated vaccine known as LAIV or nasal spray.

Natural immunity: Two-thirds of those surveyed (67%) know it is false to say that because babies are born with natural immunity, they don’t need to be vaccinated against childhood illnesses until they are likely to be exposed to them. But one-third of those surveyed think either that this is true (17%) or are not sure (16%).

The flu and pregnancy

In a series of true-or-false questions:

Only 1 in 4 people (26%) know that a pregnant person who gets the flu is at higher risk of delivering the baby early. About the same number (27%) think that is false. Nearly half of those surveyed (46%) are not sure.

Only half of those surveyed (52%) know it is true that a flu shot protects pregnant people and their babies from serious health problems both during and after pregnancy.

COVID-19 and pregnancy

The CDC says that pregnant people “are more likely to get severely ill with COVID-19 compared with non-pregnant people.” The CDC says pregnant people “can receive a COVID-19 vaccine” and that getting the vaccine during pregnancy can prevent an individual from getting severely ill from COVID-19. The survey found that:

• Over half (55%) know it is false to claim that COVID-19 vaccination affects a couple’s chances of getting pregnant, but 15% incorrectly think it is true and 30% are not sure.
• Only 1 in 5 people (22%) know it is true that COVID-19 vaccines can cause “a small, temporary increase in the length of a vaccinated person’s menstrual cycle,” while 17% incorrectly say it is false and most people (61%) are unsure.
• Just over half of those surveyed (52%) know that COVID-19 vaccination during pregnancy is safe, while 22% incorrectly think it is false and 26% are not sure.
• Just over half (55%) know that getting a COVID-19 vaccine can reduce the risk of COVID-19 complications that can affect a pregnancy, while 17% incorrectly say this is false and 28% are not sure.
• Just over half (56%) know that COVID-19 vaccination during pregnancy is effective at minimizing the chances of hospitalization with COVID-19, while 25% are not sure and 19% say it is false.
• Over 1 in 3 people know (36%) that getting a COVID-19 vaccine during pregnancy can protect an infant from birth to six months of age from COVID-related hospital stays. But 23% think this is false and 41% are not sure.

Other health risks

Many of those surveyed are aware of certain health risks:

• 73% know that untreated high blood pressure increases the likelihood that someone who is pregnant will have a stroke, though 21% say they are not sure and 6% incorrectly think it is false.
• 78% know that pregnant people should be tested for diabetes, though 16% are not sure and 6% incorrectly think it is false. According to the CDC, from 1 in 50 to 1 in 20 pregnant women has gestational diabetes, which sometimes does not go away after delivery or can return as type 2 diabetes.
• 90% know that how well a person takes care of their health before getting pregnant affects the health of their baby.
• 92% know that how well a person takes care of their health during their pregnancy affects the health of their baby.

Smoking and drinking

After years of warnings about the dangers of smoking, many in the public are knowledgeable about the potential harms during pregnancy:

• 72% know that smoking during pregnancy increases the chances that the baby will be born early, though 18% are not sure and 10% think this is false.
• 83% know that smoking during pregnancy increases the chances that the baby will have birth defects, though 9% are not sure and 8% think this is false.
• 85% know it is false to say that drinking wine or beer while pregnant is safe though 8% say this is true and 6% are not sure.

Smoking and SIDS: Fewer people are aware of the connection between smoking and sudden infant death syndrome, or SIDS. Just over half (52%) know that smoking in the home of a baby increases the chances that the baby will die from sudden infant death syndrome, while 30% are not sure and 18% say this is false.

Smoking and birth weight: Asked what effect smoking during pregnancy would likely have on a baby’s weight at birth, most (76%) said it increases the chances that the smoker’s baby will be underweight at birth, compared with those who think it increases the chances the baby will be overweight (2%) or have no effect on the baby’s weight (2%). 20% were not sure.

Drinking and pregnancy: Asked which statement is most accurate, 65% know that someone who wants to get pregnant should stop drinking alcohol before pregnancy and not drink during pregnancy—compared with 25% who say someone who wants to get pregnant should stop drinking as soon as they learn they are pregnant, 4% who say someone who wants to get pregnant should limit their alcohol intake while pregnant to two drinks a day, and 6% who are not sure. The CDC says someone who is trying to get pregnant might already be pregnant, so “the best advice is for women to stop drinking alcohol when they start trying to get pregnant.”

Pregnancy health care

Folic acid: Most of those surveyed know that pregnant people should take vitamins containing folic acid: 76% know that individuals who are or may become pregnant should take a daily vitamin that contains folic acid, which is a B vitamin, though 21% are not sure and 3% say it is false. The CDC recommends this for people who are pregnant.

Pregnancy weight gain: Asked which is the most accurate statement about weight gain for a person of “normal weight” during pregnancy, 45% correctly say a gain of between 25 and 35 pounds; 24% say a gain of between 5 and 10 pounds; 26% are not sure; and 5% say “try not to gain weight during pregnancy.” The CDC says 25 to 35 pounds is the recommended weight gain for a person of normal weight.

Benefits from breastfeeding: 71% know it’s most accurate to say that breastfeeding benefits both the breastfed baby and parent, as opposed to 17% who say it benefits the baby, 1% who say it’s the parent, and 1% neither. The CDC says breastfeeding benefits both baby and parent.

Getting a newborn to sleep

How to put a baby down to sleep: 61% correctly say a new baby should be put down to sleep on its back, 12% say on its side, 12% say on its stomach, and 15% are not sure. The CDC recommends putting a baby to sleep on its back.

Avoid soft bedding: The CDC recommends keeping “soft bedding such as blankets, pillows, bumper pads, and soft toys out of their baby’s sleep area…” but many of those surveyed are not aware of this. Asked which of the following should be kept out of a baby’s sleep area:

• 72% say that pillows should be kept out of a baby’s sleep area
• 69% say soft toys
• 54% say soft bedding such as blankets
• 43% say bumper pads

Mental health: The 988 suicide lifeline

The survey also sought to determine whether the public had become familiar with the new three-digit Suicide and Crisis Lifeline, 988, introduced in July 2022. Nearly a year after its introduction, however, the survey found that only 20% of those surveyed said they knew the number—and when asked to provide it, just over half that group could do so, or 10% of the total.

This finding is not statistically different from January 2023, four and a half months earlier, when 9% could provide the number—suggesting that there has been little progress in familiarizing the public with a vitally important suicide-prevention resource.

By contrast, 86% of the public knows to dial the number 911 when someone is experiencing a health emergency.

The survey data come from the 11th wave of a nationally representative panel of 1,601 US adults, first empaneled in April 2021, conducted for the Annenberg Public Policy Center by SSRS, an independent market research company. This wave of the Annenberg Science and Public Health Knowledge (ASAPH) survey was fielded May 31-June 6, 2023. It has a margin of sampling error (MOE) of ± 3.3 percentage points at the 95% confidence level.

Download the topline and the methodology.

Source: Penn

New research digs into why the paths of meandering rivers change over time and how climate change could affect them.

The researchers first looked at the Mississippi River before adding other rivers on Earth and ancient riverbeds on Mars to the study.

The study specifically looks at river sinuosity, or how much rivers curve. The sinuosity of rivers changes over time, depending on the age of the river and environmental changes. Some of these changes include sediment and water supply and riverbank vegetation, all of which climate change affects.

As reported in Nature Geosciences, river sinuosity is related to the changes in how much water flows through the river. Rivers have different water levels depending on environmental factors, like precipitation levels.

The researchers looked at maps of the rivers on Earth over time by using historical data from as early as the fifth century and images from as early as 1939. They used data of 21 lowland meandering rivers.

For the ancient riverbeds on Mars, they used previously identified ancient river channels from remote sensing data.

The ancient riverbeds on Mars, untouched by human influence, gave the researchers a system to test their hypotheses on how the river systems migrated and what their sinuosity looked like by the time they dried up.

Their analysis is also a step toward understanding what the hydroclimate on Mars was like when there was still surface water.

“It really lays the foundation for more advanced topics,” says Chenliang Wu, a postdoctoral researcher at Tulane University School of Science and Engineering. “Like, were the environmental conditions suitable for life on Mars?”

After performing analysis on the rivers, the researchers separated them into two categories: variable-sinuosity and constant-sinuosity. The variable-sinuosity rivers never reached a steady state, meaning their sinuosities continue changing, and the constant sinuosity rivers did reach a steady state, meaning their average sinuosity remained relatively constant.

Of the 21 Earth rivers studied, 13, including the Mississippi River, had variable sinuosity, while eight had constant sinuosity.

Understanding what factors affect the sinuosity of rivers will give researchers and engineers insight into how to manage rivers in the future. It can help with river restoration, future infrastructure projects, and flood management. This insight can be invaluable in attempts to mitigate the impacts of climate change.

As more extreme weather happens more frequently due to the effects of climate change, research like Wu’s will become even more important when it comes to protecting and helping populations who live near rivers.

According to a 2019 study in the International Journal of Water Resources Development, half of the world’s population lives in river basins, all of whom could be affected by future floods from extreme weather events.

Source: Tulane University

A new way to see details smaller than half the wavelength of light has revealed how nanoscale scaffolding inside cells bridges to the macroscale during cell division.

Unlike earlier superresolution techniques, this one doesn’t rely on molecules that wear out with prolonged use.

Superresolution can reveal structures down to 10 nanometers, or about the same breadth as 100 atoms. It opened a whole new world in biology, and the techniques that first made it possible received a Nobel Prize in 2014. However, its weakness is that it can only take snapshots over tens of seconds. This makes it impossible to observe the evolution of the machinery of a cell over long periods of time.

“We were wondering—when the system as a whole is dividing, how do nanometer-scale structures interact with their neighbors at the nanometer scale, and how does this interaction scale up to the whole cell?” says Somin Lee, assistant professor of electrical and computer engineering at the University of Michigan, who led the study published in Nature Communications.

To answer that question, Lee and colleagues needed a new kind of superresolution. Using their new method, they were able to continuously monitor a cell for 250 hours.

“The living cell is a busy place with proteins bustling here and there. Our superresolution is very attractive for viewing these dynamic activities,” says Guangjie Cui, a PhD student in electrical and computer engineering and co-first author of the study with Yunbo Liu, a PhD graduate in electrical and computer engineering.

Like the original method, the new technique uses probes near the nanoscale objects of interest to shed light on them. Superresolution 1.0 used fluorophores for this, fluorescent molecules that would send out an answering light after being illuminated. If the fluorophores were closer together than the size of whatever was being imaged, the image could be reconstructed from the bursts of light produced by the fluorophores.

The new technique uses gold nanorods, which don’t break down with repeated exposure to light, but making use of the light that interacts with them is more challenging. Nanorods respond to the phase of the light, or where it is in the up-and-down oscillation of the electric and magnetic fields that compose it. This interaction depends on how the nanorod is angled to the incoming light.

Like the fluorophores, the nanorods can attach to particular cell structures with targeting molecules on their surfaces. In this case, the nanorods sought out actin, a protein that adds structure to soft cells. Actin is shaped like branching filaments, each about 7 nanometers (millionths of a millimeter) in diameter, though they link together to span thousands of nanometers. Even though the nanorods are often more than twice the diameter of the actin, the data they provide as a group can illuminate its tiny details.

To locate the nanorods, the team built filters made of thin layers of polymers and liquid crystals. These filters enabled the detection of light with a particular phase, enabling the team to pick out nanorods with particular angles to the incoming light. By taking 10 to 30 images—each looking at a different subset of nanorods—and merging them into a single image, the team was able to deduce the nanometer-scale details of the filaments inside the cells. These details would be blurred out in conventional microscopes.

Using the technique, the team discovered three rules governing the way that actin self-organizes during cell division:

• Actin expands to reach its neighbors when actin filaments are far apart.
• Actin will draw nearer to its neighbors to increase connections, although this tendency is tempered by the drive to expand and reach more neighbors.
• As a result, the actin network tends to contract when it is more connected, and it will expand when it is less connected.

The behavior of the actin is connected to the behavior of the cell—but the cell contracts when the actin expands, and it expands when the actin contracts. The team wants to explore this further, discovering why the motions are opposite at different scales. They also want to investigate the consequences of dysregulating this molecular process: Is this at the root of some diseases?

More broadly, they hope to use superresolution to understand how self-organization is built into biological structures, without the need for central control.

“Our genetic code doesn’t actually include enough information to encode every detail of the organization process,” Lee says. “We want to explore the mechanisms of collective behaviors without central coordination that are like birds flying in formation—in which the system is driven by interactions between individual parts.”

The study had support from the Air Force Office of Scientific Research and the National Science Foundation.

Source: University of Michigan

After decades of decline, fatal coronary heart disease may rise again unless Americans modify three major risk factors: smoking, drinking, and obesity.

A new study published in American Heart Journal finds that deaths from coronary heart disease among people ages 25 to 84 dropped to 236,953 in 2019 from 397,623 in 1990, even though Americans’ median age increased to 38 from 33 over the last three decades.

Between 1990 and 2019, the US age-standardized coronary heart disease mortality rate per 100,000 fell from 210.5 to 66.8 for females (4% decline per year) and from 442.4 to 156.7 for males (3.7% decline per year). However, the decline has slowed significantly since 2011. People born after 1980 were actually at slightly increased risk of dying from coronary heart disease at any age than people from the previous generation.

The findings echo those from the same team’s investigation of stroke-related deaths in the US.

The researchers note that while future advances in treatment continue reducing fatal heart disease, complementary lifestyle modifications may play an important role. They estimated that the elimination of smoking, drinking, and obesity would have prevented half of the deaths observed during the study period.

“The overall numbers are good. We saw a substantial decline in deaths from all types of coronary heart disease for both females and males,” says lead author Cande Ananth, chief of the division of epidemiology and biostatistics in the obstetrics, gynecology, and reproductive sciences department at Rutgers Robert Wood Johnson Medical School.

“However, because we examined how these three modifiable risk factors affected mortality rates, we can see that there is room for considerable improvement.”

Tobacco use is already headed in the right direction: The percentage of Americans who smoked tobacco fell to 14% in 2019 from 26% in 1990. Obesity rates, on the other hand, rose sharply during the study period to 43% in 2019 from 12% in 1990. Alcohol usage rose slightly during the study period.

In addition to the reduction in smoking, other factors driving the decline in coronary heart disease mortality include statins (which lower cholesterol), better diagnostic tests, and more frequent use of those tests.

“Although myocardial infarctions happen without warning, the other two major types of coronary heart disease—chronic ischemic heart disease and atherosclerotic heart disease—can be diagnosed and treated years before they damage the heart muscles,” says Ananth, whose analyses of past trends aspire to improve future care.

To achieve this, Ananth’s research team analyzes the largest possible datasets to differentiate risk among various patient subsets. The new study used anonymized data from the National Center for Health Statistics to track all heart disease fatalities in the targeted age range for the three-decade period.

“The ultimate goal is to help inform standards of care and public health priorities by determining which patients face the highest level of risk for cardiovascular events,” Ananth says.

“Although increased screening and population-wide interventions are possible, the returns are likely to be minimal, at best, while costs will be prohibitively high. We need to maximize returns from our limited resources by identifying high-risk subsets of patients and targeting intervention to them.”

The team’s next study will analyze cardiovascular disease risk among pregnant patients.

Source: Rutgers University

A new robotic gripping device offers high degrees of strength, gentleness, and dexterity, researchers report.

The gripper is gentle enough to pick up a drop of water, strong enough to pick up a 14.1 pound weight, dexterous enough to fold a cloth, and precise enough to pick up microfilms that are 20 times thinner than a human hair.

In addition to possible manufacturing applications, the researchers also integrated the device with technology that allows the gripper to be controlled by the electrical signals produced by muscles in the forearm, demonstrating its potential for use with robotic prosthetics.

“It is difficult to develop a single, soft gripper that is capable of handling ultrasoft, ultrathin, and heavy objects, due to tradeoffs between strength, precision, and gentleness,” says Jie Yin, associate professor of mechanical and aerospace engineering at North Carolina State University and corresponding author of the study in Nature Communications. “Our design achieves an excellent balance of these characteristics.”

The design for the new grippers builds on an earlier generation of flexible, robotic grippers that drew on the art of kirigami, which involves both cutting and folding two-dimensional sheets of material to form three-dimensional shapes.

“Our new grippers also use kirigami, but are substantially different, as we learned a great deal from the previous design,” says coauthor Yaoye Hong, a recent PhD graduate from NC State. “We’ve been able to improve the fundamental structure itself, as well as the trajectory of the grippers—meaning the path at which the grippers approach an object when grabbing it.”

The new design is able to achieve high degrees of strength and gentleness because of how it distributes force throughout the structure of the gripper.

“The strength of robotic grippers is generally measured in payload-to-weight ratio,” Yin says. “Our grippers weigh 0.4 grams and can lift up to 6.4 kilograms. That’s a payload-to-weight ratio of about 16,000. That is 2.5 times higher than the previous record for payload-to-weight ratio, which was 6,400. Combined with its characteristics of gentleness and precision, the strength of the grippers suggests a wide variety of applications.”

Another benefit of the new technology is that its attractive characteristics are driven primarily by its structural design, rather than by the materials used to fabricate the grippers.

“In practical terms, this means that you could fabricate the grippers out of biodegradable materials, such as sturdy plant leaves,” says Hong. “That could be particularly useful for applications where you would only want to use the grippers for a limited period of time, such as when handling food or biomedical materials. For example, we’ve demonstrated that the grippers can be used to handle sharp medical waste, such as needles.”

The researchers also integrated the gripping device with a myoelectric prosthetic hand, meaning the prosthesis is controlled using muscle activity.

“This gripper provided enhanced function for tasks that are difficult to perform using existing prosthetic devices, such as zipping certain types of zippers, picking up a coin, and so on,” says coauthor Helen Huang, professor in the joint biomedical engineering department at NC State and the University of North Carolina at Chapel Hill.

“The new gripper can’t replace all of the functions of existing prosthetic hands, but it could be used to supplement those other functions,” Huang says. “And one of the advantages of the kirigami grippers is that you would not need to replace or augment the existing motors used in robotic prosthetics. You could simply make use of the existing motor when utilizing the grippers.”

In proof-of-concept testing, the researchers demonstrated that the kirigami grippers could be used in conjunction with the myoelectric prosthesis to turn the pages of a book and pluck grapes off a vine.

“We think the gripper design has potential applications in fields ranging from robotic prosthetics and food processing to pharmaceutical and electronics manufacturing,” Yin says. “We are looking forward to working with industry partners to find ways to put the technology to use.”

The National Science Foundation supported the work.

Source: NC State

A new paper details the discovery of the highest-energy light ever observed from the sun.

“The sun is more surprising than we knew,” says Mehr Un Nisa, a postdoctoral research associate at Michigan State University. “We thought we had this star figured out, but that’s not the case.”

Nisa, who will soon be joining Michigan State’s faculty, is the corresponding author of the new paper in the journal Physical Review Letters.

The team behind the discovery also found that this type of light, known as gamma rays, is surprisingly bright. That is, there’s more of it than scientists had previously anticipated.

Although the high-energy light doesn’t reach the Earth’s surface, these gamma rays create telltale signatures that Nisa and her colleagues working with the High-Altitude Water Cherenkov Observatory, or HAWC, detected.

HAWC is an important part of the story. Unlike other observatories, it works around the clock.

“We now have observational techniques that weren’t possible a few years ago,” says Nisa, who works in the Department of Physics and Astronomy in the College of Natural Science.

“In this particular energy regime, other ground-based telescopes couldn’t look at the sun because they only work at night,” she says. “Ours operates 24/7.”

In addition to working differently from conventional telescopes, HAWC looks a lot different from the typical telescope.

Rather than a tube outfitted with glass lenses, HAWC uses a network of 300 large water tanks, each filled with about 200 metric tons of water. The network is nestled between two dormant volcano peaks in Mexico, more than 13,000 feet above sea level.

From this vantage point, it can observe the aftermath of gamma rays striking air in the atmosphere. Such collisions create what are called air showers, which are a bit like particle explosions that are imperceptible to the naked eye.

The energy of the original gamma ray is liberated and redistributed amongst new fragments consisting of lower energy particles and light. It’s these particles—and the new particles they create on their way down—that HAWC can “see.”

When the shower particles interact with water in HAWC’s tanks, they create what’s known as Cherenkov radiation that can be detected with the observatory’s instruments.

Nisa and her colleagues began collecting data in 2015. In 2021, the team had accrued enough data to start examining the sun’s gamma rays with sufficient scrutiny.

“After looking at six years’ worth of data, out popped this excess of gamma rays,” Nisa says. “When we first saw it, we were like, ‘We definitely messed this up. The sun cannot be this bright at these energies.’”

The sun gives off a lot of light spanning a range of energies, but some energies are more abundant than others.

For example, through its nuclear reactions, the sun provides a ton of visible light—that is, the light we see. This form of light carries an energy of about 1 electron volt, which is a handy unit of measure in physics.

The gamma rays that Nisa and her colleagues observed had about 1 trillion electron volts, or 1 tera electron volt, abbreviated 1 TeV. Not only was this energy level surprising, but so was the fact that they were seeing so much of it.

In the 1990s, scientists predicted that the sun could produce gamma rays when high-energy cosmic rays—particles accelerated by a cosmic powerhouse like a black hole or supernova—smash into protons in the sun. But, based on what was known about cosmic rays and the sun, the researchers also hypothesized it would be rare to see these gamma rays reach Earth.

At the time, though, there wasn’t an instrument capable of detecting such high-energy gamma rays and there wouldn’t be for a while. The first observation of gamma rays with energies of more than a billion electron volts came from NASA’s Fermi Gamma-ray Space Telescope in 2011.

Over the next several years, the Fermi mission showed that not only could these rays be very energetic, but also that there were about seven times more of them than scientists had originally expected. And it looked like there were gamma rays left to discover at even higher energies.

When a telescope launches into space, there’s a limit to how big and powerful its detectors can be. The Fermi telescope’s measurements of the sun’s gamma rays maxed out around 200 billion electron volts.

Theorists led by John Beacom and Annika Peter, both professors at Ohio State University, encouraged the HAWC Collaboration to take a look.

“They nudged us and said, ‘We’re not seeing a cutoff. You might be able to see something,” Nisa says.

Now, for the first time, the team has shown that the energies of the sun’s rays extend into the TeV range, up to nearly 10 TeV, which does appear to be the maximum, Nisa says.

Currently, the discovery creates more questions than answers. Solar scientists will now scratch their heads over how exactly these gamma rays achieve such high energies and what role the sun’s magnetic fields play in this phenomenon, Nisa says.

When it comes to the cosmos, though, that’s part of the excitement. It tells us that there was something wrong, missing, or perhaps both when it comes to how we understand our nearest and dearest star.

“This shows that HAWC is adding to our knowledge of our galaxy at the highest energies, and it’s opening up questions about our very own sun,” Nisa says. “It’s making us see things in a different light. Literally.”

The HAWC Collaboration includes more than 30 institutions across North America, Europe, and Asia and has funding from the National Science Foundation and the National Council of Humanities Science and Technology.

Source: Matt Davenport for Michigan State University

Targeting the bubble-like membrane of a virus, rather than its proteins, could lead to a new generation of antivirals, researchers report.

Antiviral therapies are notoriously difficult to develop, as viruses can quickly mutate to become resistant to drugs. But what if a new generation of antivirals ignores the fast-mutating proteins on the surface of viruses and instead disrupts their protective layers?

“We found an Achilles heel of many viruses: their bubble-like membranes. Exploiting this vulnerability and disrupting the membrane is a promising mechanism of action for developing new antivirals,” says Kent Kirshenbaum, professor of chemistry at New York University and senior author of the study in the journal ACS Infectious Diseases.

In the study, the researchers show how a group of new molecules inspired by our own immune system inactivates several viruses, including Zika and chikungunya. The approach may not only lead to drugs that can be used against many viruses, but could also help overcome antiviral resistance.

Urgent need for new drugs

Viruses have different proteins on their surfaces that are often the targets of therapeutics like monoclonal antibodies and vaccines. But targeting these proteins has limitations, as viruses can quickly evolve, changing the properties of the proteins and making treatments less effective. These limitations were on display when new SARS-CoV-2 variants emerged that evaded both the drugs and the vaccines developed against the original virus.

“There is an urgent need for antiviral agents that act in new ways to inactivate viruses,” Kirshenbaum says. “Ideally, new antivirals won’t be specific to one virus or protein, so they will be ready to treat new viruses that emerge without delay and will be able to overcome the development of resistance.”

“We need to develop this next generation of drugs now and have them on the shelves in order to be ready for the next pandemic threat—and there will be another one, for sure,” he says.

Our innate immune system combats pathogens by producing antimicrobial peptides, the body’s first line of defense against bacteria, fungi, and viruses. Most viruses that cause disease are encapsulated in membranes made of lipids, and antimicrobial peptides work by disrupting or even bursting these membranes.

While antimicrobial peptides can be synthesized in the lab, they are rarely used to treat infectious diseases in humans because they break down easily and can be toxic to healthy cells. Instead, scientists have developed synthetic materials called peptoids, which have similar chemical backbones to peptides but are better able to break through virus membranes and are less likely to degrade.

“We began to think about how to mimic natural peptides and create molecules with many of the same structural and functional features as peptides, but are composed of something that our bodies won’t be able to rapidly degrade,” says Kirshenbaum.

The researchers investigated seven peptoids, many originally discovered in the lab of Annelise Barron at Stanford University and a coauthor of the study. The NYU team studied the antiviral effects of the peptoids against four viruses: three enveloped in membranes (Zika, Rift Valley fever, and chikungunya) and one without (coxsackievirus B3).

“We were particularly interested in studying these viruses as they have no available treatment options,” says Patrick Tate, a chemistry PhD student at NYU and the study’s first author.

Antiviral effect

The membranes surrounding viruses are made of different molecules than the virus itself, as lipids are acquired from the host to form membranes. One such lipid, phosphatidylserine, is present in the membrane on the outside of viruses, but is sequestered towards the interior of human cells under normal conditions.

“Because phosphatidylserine is found on the exterior of viruses, it can be a specific target for peptoids to recognize viruses, but not recognize—and therefore spare—our own cells,” Tate says. “Moreover, because viruses acquire lipids from the host rather than encoding from their own genomes, they have better potential to avoid antiviral resistance.”

The researchers tested seven peptoids against the four viruses. They found that the peptoids inactivated all three enveloped viruses—Zika, Rift Valley fever, and chikungunya—by disrupting the virus membrane, but did not disrupt coxsackievirus B3, the only virus without a membrane.

Moreover, chikungunya virus containing higher levels of phosphatidylserine in its membrane was more susceptible to the peptoids. In contrast, a membrane formed exclusively with a different lipid named phosphatidylcholine was not disrupted by the peptoids, suggesting that phosphatidylserine is crucial in order for peptoids to reduce viral activity.

“We’re now starting to understand how peptoids actually exert their antiviral effect—specifically, through the recognition of phosphatidylserine,” says Tate.

The researchers are continuing pre-clinical studies to evaluate the potential of these molecules in fighting viruses and to understand if they can overcome the development of resistance. Their peptoid-focused approach may hold promise for treating a wide range of viruses with membranes that can be difficult to treat, including Ebola, SARS-CoV-2, and herpes.

Additional coauthors are from Loyola University Chicago Medical Center, Maxwell Biosciences, and the University of Louisville School of Dentistry.

The National Science Foundation and the National Institutes of Health supported the work. Kirshenbaum is the chief scientific officer for Maxwell Biosciences, a biotech company that has licensed patents originating from his lab at NYU. The company is seeking to commercialize these compounds and bring them to the clinic to advance human health.

Source: NYU

A study of older US adults finds that the risk of negative effects of both mRNA COVID vaccines is exceptionally low, but lowest with the Moderna vaccine.

While mRNA vaccines against COVID-19 have been found to be safe and effective for the general population, in-depth evidence about safety and effectiveness for older adults and individuals with chronic health conditions is more limited.

To address that gap, researchers conducted the largest head-to-head comparison study of the two mRNA vaccines approved by the US Food and Drug Administration—the Moderna and Pfizer-BioNTech vaccines.

The results showed that, for older adults, the Moderna vaccine was associated with a slightly lower risk of adverse events than the Pfizer-BioNTech vaccine.

The findings are published in JAMA Network Open.

“The results of this study can help public health experts weigh which mRNA vaccine might be preferred for older adults and older subgroups, such as those with increased frailty,” says lead study author Daniel Harris, an epidemiologist and research scientist in the Center for Gerontology and Healthcare Research at the Brown University School of Public Health.

The study looked at more than six million older adults, with the average age of 76 years, who were vaccinated against COVID-19 using one of the two mRNA vaccines, Moderna and Pfizer-BioNTech. The vaccines have subtle differences in manufacturing, administration, and immune response.

The study confirmed that for older adults in both vaccine groups, the risk of serious adverse events was very low. The researchers also observed that for these older adults, the Moderna vaccine was associated with a 4% lower risk of pulmonary embolism, which is a sudden blockage in blood vessels of the lungs, and a 2% lower risk of thromboembolic events, defined as several conditions related to blood clotting.

The Moderna vaccine was also associated with a 15% lower risk of diagnosed COVID-19 compared to the Pfizer-BioNTech vaccine.

The risk of adverse events from a natural infection with SARS-CoV-2, the virus that causes COVID-19, is substantially higher than the risk of adverse events from either mRNA vaccine, Harris emphasizes. But now that over 70% of the global population has received one type of COVID-19 vaccine and vaccine supply is less of a concern, he says there is a need for detailed information about vaccine effects and safety to guide decision-making.

“Immunization with either mRNA vaccine is substantially better and safer than not being vaccinated at all,” Harris says. “But in an ideal world where we can have a choice between which vaccine product is used, we wanted to see whether one vaccine was associated with better performance for older adults and those with increased frailty.”

There is also a need to understand vaccine performance in real-world populations, Harris says. He notes that older adults, who often have chronic health conditions, tend to be excluded from clinical trials or represented in small numbers. This is especially important considering that older adults, especially those in nursing homes, had a higher risk of developing severe COVID-19.

Older adults with frailty can also have differences in their immune responses to vaccines, Harris says, making it important to understand how these vaccines work for frail older adults compared to their non-frail counterparts.

The research is part of a project called the IMPACT Collaboratory, led by researchers at Brown University and Boston-based Hebrew SeniorLife, which is enabling massive monitoring of the long-term safety and effectiveness of COVID-19 vaccines for Medicare beneficiaries, in collaboration with CVS and Walgreens pharmacies.

“Because we had these real-world data and a cohort that included millions of older adults, we were able to tease apart potentially very small differences in vaccine safety and effectiveness and perform analyses on important clinical subgroups,” Harris says.

According to the researchers, the improved safety of the Moderna vaccine for some adverse events, like pulmonary embolism, could have been due to its greater protection against COVID-19, especially for non-frail older adults.

“We think that these two things, safety and effectiveness, are interrelated,” Harris says. “The slightly reduced risk of pulmonary embolism and other adverse events that we saw in individuals who received Moderna may be because the Moderna vaccine was also more effective at reducing COVID-19 risk.”

However, the study was unable to definitively conclude whether the differences in adverse events were due to safety or effectiveness, and the researchers recommended additional research in this area. The study also only looked at the first dose of the mRNA vaccines, so another potential next step could involve similar comparisons for subsequent vaccinations.

“You can imagine regularly updating these types of analyses as new vaccines are developed,” Harris says. “Depending on which one comes out on top, even on a very small scale, that may have big implications at the population level and render a preference for that particular vaccine.”

The National Institute on Aging of the National Institutes of Health funded the work.

Source: Brown University