New lightweight super material could battle bullets, deflect space debris

by Adam Malecek, University of Wisconsin-Madison

Credit: CC0 Public Domain

University of Wisconsin–Madison engineers have created a nanofiber material that outperforms its widely used counterparts—including steel plates and Kevlar fabric—in protecting against high-speed projectile impacts.

Basically, it's better than bulletproof.

"Our nanofiber mats exhibit protective properties that far surpass other material systems at much lighter weight," says Ramathasan Thevamaran, a UW–Madison assistant professor of engineering physics who led the research.

He and his collaborators detailed the advance in a paper published recently in the journal ACS Nano.

To create the material, Thevamaran and postdoctoral researcher Jizhe Cai mixed multi-walled carbon nanotubes—carbon cylinders just one atom thick in each layer—with Kevlar nanofibers. The resulting nanofiber mats are superior at dissipating energy from the impact of tiny projectiles moving faster than the speed of sound.

The advance lays the groundwork for carbon nanotube use in lightweight, high-performance armor materials, for example, in bulletproof vests to better protect the wearer or in shields around spacecraft to mitigate damage from flying high-speed microdebris.

"Nano-fibrous materials are very attractive for protective applications because nanoscale fibers have outstanding strength, toughness, and stiffness compared to macroscale fibers," Thevamaran says. "Carbon nanotube mats have shown the best energy absorption so far, and we wanted to see if we could further improve their performance."

They found the right chemistry. The team synthesized Kevlar nanofibers and incorporated a tiny amount of them into their carbon nanotube mats, which created hydrogen bonds between the fibers. Those hydrogen bonds modified the interactions between the nanofibers and, along with just the right mixture of Kevlar nanofibers and carbon nanotubes, caused a dramatic leap in the overall material's performance.

"The hydrogen bond is a dynamic bond, which means it can continuously break and re-form again, allowing it to dissipate a high amount of energy through this dynamic process," Thevamaran says. "In addition, hydrogen bonds provide more stiffness to that interaction, which strengthens and stiffens the nanofiber mat. When we modified the interfacial interactions in our mats by adding Kevlar nanofibers, we were able to achieve nearly 100% improvement in energy dissipation performance at certain supersonic impact velocities."

Bring on the bullets. The researchers tested their new material using a laser-induced microprojectile impact testing system in Thevamaran's lab. One of only a handful like it in the United States, the system uses lasers to shoot micro-bullets into the material samples.

"Our system is designed such that we can actually pick a single bullet under a microscope and shoot it against the target in a very controlled way, with a very controlled velocity that can be varied from 100 meters per second all the way to over 1 kilometer per second," Thevamaran says. "This allowed us to conduct experiments at a time scale where we could observe the material's response—as the hydrogen bond interactions happen."

In addition to its impact resistance, another advantage of the new nanofiber material is that, like Kevlar, it is stable at both very high and very low temperatures, making it useful for applications in a wide range of extreme environments.

Synthesis of diamond-like carbon nanofiber film

More information: Jizhe Cai et al, Extreme Dynamic Performance of Nanofiber Mats under Supersonic Impacts Mediated by Interfacial Hydrogen Bonds, ACS Nano (2021). DOI: 10.1021/acsnano.1c07465

Journal information: ACS Nano 

Provided by University of Wisconsin-Madison 

Social networking for fossils shows community impacts of mass extinctions

by University of Texas at Austin

An example of network with connections between various forms of ancient sea life. This 

chart is a teaching tool and is not the actual network constructed by researchers in the 

study. Credit: Drew Muscente.

By applying an algorithm akin to what Facebook uses to make friend suggestions, researchers have identified communities of ancient life in the fossil record and tracked how their numbers changed through each of the planet's mass extinctions.

As expected, the number of communities—a group of different species living in the same general area—dropped during mass extinction events. But the rate at which communities disappeared did not always track with the overall loss of life and biodiversity during an extinction, a result that suggests that the ecological impacts of an extinction are not always linked with the number of species that perish.

"There have been times in our history where there have been major events that saw tremendous changes in communities, but very few species disappeared," said lead author Drew Muscente, who conducted the study when he was a postdoctoral researcher at The University of Texas at Austin's Jackson School of Geosciences. "And there have been events where many species had disappeared and communities and ecosystems were barely affected at all."

Muscente is now an assistant professor at Cornell College. The study was recently published in the journal Geology.

The results underscore the importance of studying communities to get a broader perspective on environmental change—both in the past and in the present.

"We try to understand how changes in these communities lead to fundamental transformation of entire ecosystems," said coauthor Rowan Martindale, an associate professor at the Jackson School.

Identifying communities in the fossil record is notoriously difficult. Most research on paleocommunities focuses on comparing samples and collections of fossils that have been taken from rocks of various ages and locations. And although conventional computational methods can be used to group samples into paleocommunities, they work best with relatively small datasets of only a few hundred or thousand fossil collections. Due to this limitation, the conventional methods can only be applied to data from specific regions and time periods, as opposed to the entire record.

The researchers were able to overcome these challenges and examine the entire fossil record by applying a community detection algorithm based on network analysis methods. Social media companies are known for using these sorts of methods to connect users, but they are becoming increasingly applied across a range of scientific disciplines.

The researchers analyzed connections between 124,605 fossil collections, representing the

 entire history of marine animal life, and found that they can be grouped into 3,937

 paleocommunities (shown here as colored dots). Credit: Muscente et al.

According to Muscente, this study is the first time that network analysis has been applied to detect paleocommunities throughout the entire fossil record of marine animal life—from when animal life first appeared to the current geologic era.

Matthew Clapham, a paleobiology professor at the University of California Santa Cruz who was not involved with the study, said that another advantage of the network analysis method is the emphasis on visualizing connections, rather than just the types of animals present in an ecosystem.

"It brings the analysis closer to the way that the communities actually worked because communities and interactions between species are networks," he said.

Drawing on a database of 124,605 collections of marine animal fossils from around the world, and representing 25,749 living and extinct animal groups, or genera, the algorithm identified more than 47 million links between these samples and organized them into 3,937 distinct paleocommunities.

The study tracked the communities and biodiversity over the past 541 million years. The research showed that while mass extinction events took a toll on both, the degree of decline sometimes differed.

Some extinctions affected communities more than biodiversity. Some affected biodiversity more than communities. And some affected both about the same.

Furthermore, the researchers did not find a link between the cause of an extinction and whether it took a great toll on communities or biodiversity.

The results indicate that the larger ecological impacts of extinction are more about which species are lost rather than the number of species lost. If an environment's key players are preserved, communities can remain intact. But if too many of these players are removed, the community crumbles with it.

Muscente said he hopes that the network analysis methods first applied in this study can be improved and used to study modern ecosystems.

"I'd like to try and bridge the gap from the rock record to the present," he said.

Predator species help to buffer climate change impacts on biodiversity

More information: A.D. Muscente et al, Appearance and disappearance rates of Phanerozoic marine animal paleocommunities, Geology (2021). DOI: 10.1130/G49371.1

Journal information: Geology 

Provided by University of Texas at Austin 

Rise of termite clone queendoms offers clue to curb invasions

Preventing a homeowner headache

Peer-Reviewed Publication

UNIVERSITY OF SYDNEY

 

IMAGE: AN ALL-FEMALE DRYWOOD TERMITE COLONY view more 

CREDIT: TOMONARI NOZAKI

Four years ago, entomologists at the University of Sydney discovered the existence of all-female, forest-dwelling drywood termite colonies in Japan. Now, they have determined how they evolved, and the implications of insect ‘girl power’ for established termite species (hint: they’re bad).

Their new research shows all-female colonies of drywood termites (Glyptotermes nakajimai) developed through unwitting human-assisted hybridisation some time in the last century. Females from one lineage mated with males from another, as one lineage was unknowingly moved from a smaller island to mainland Japan, likely via boat. Their hybrid offspring are more genetically diverse, and likely to be more robust.

In addition to stronger offspring, the all-female colonies can clone themselves and do not require a male to procreate, resulting in double the amount of breeding. According to the researchers, this is bad news for the incumbent, non-hybrid species, which can be outcompeted by its hybrid relatives.

It’s also potentially bad news for property owners. Drywood termites, as their name suggests, do not require moist conditions to burrow into and eat wooden beams, walls, floors or furniture, and are commonly moved around the world by trade, opening the door to hybridisation events. Once an infestation occurs, it can be difficult to eradicate, potentially leading to structural damage to a building, or even collapse.

Professor Nathan Lo, who led the study with University of Sydney Postdoctoral Fellow Toshihisa Yashiro, said his findings have implications for biosecurity: “Our study highlights the importance of making sure termites from overseas are not permitted to establish themselves. If they were to hybridise with local termites, it might lead to even nastier lineages of termites for homeowners to deal with.”

‘Really weird’ males

Aside from discerning how the female colonies evolved, the researchers also studied several drywood termite colonies with males and females, which contained a quirk: the sperm of males consisted of either 15 Y or 15 X chromosomes, out of a total of 17. In most species, including humans, male sperm have only a single Y or X chromosome (out of 23, in the case of humans).

“It’s really weird,” said Professor Lo, who posits that this occurred out of necessity.

“Termite offspring can inherit nests from their parents, saving them the trouble of venturing into the dangers of the outside world, burrowing into wood, and creating their own nests. The problem with nest inheritance is that it results in a lot of inbreeding – sisters mate with brothers, and offspring may even mate with parents.

“As a solution, male termites probably evolved to have multiple Y chromosomes, making them harbour more genetic diversity than females. So, even if a sister and brother mate, they can produce viable offspring.”

The researchers say that this chromosomal pattern is found in some other organisms, including plants and huntsman spiders, but not usually to the extremes found in drywood termites.

About the study

The results have been published in the high-impact journal Proceedings of the National Academy of Sciences. Termites were collected and preserved by Dr Yashiro prior to undertaking his fellowship in Professor Lo’s lab in Sydney, and DNA was analysed in Australia using nuclear SNP and mitochondrial markers. Chromosome analyses were performed using DNA stains and fluorescence microscopy.

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JOURNAL

Proceedings of the National Academy of Sciences

DOI

10.1073/pnas.2009533118 

 ELIMINATE THE SECOND AMENDMENT

Most older adults support steps to reduce firearm injury risk, study shows

National survey highlights the subgroups of people over 50 who might benefit most from counseling and programs designed to reduce risk for them and their children

Peer-Reviewed Publication

MICHIGAN MEDICINE - UNIVERSITY OF MICHIGAN

A strong majority of American adults over 50 -- including the 37% of older adults who own guns or live with someone who does -- supports specific steps that could reduce the risk of firearm injury and death, a new national study shows.

The University of Michigan study shows support among older adults for everything from firearm safety counseling by health care providers, and background checks for firearm purchasers, to “red flag” policies that allow for temporary firearm removal from people at high risk of harming themselves or others.

The study also highlights opportunities to help older adults recognize and address the risks in their own homes, especially for those who live with children, have heightened suicide risk, or are beginning to experience cognitive decline and/or dementia.

For instance, the study shows 24% of firearm owners over age 50 regularly store at least one of their firearms loaded and unlocked, which past research has shown increases the potential risk of accidental or intentional injury. Gun locks and locked storage containers such as gun safes can reduce that risk, as can ‘smart guns’ that can only be fired by a specific individual.

Published this week in the journal Preventive Medicine, the study is based on a national survey of more than 2,000 adults aged 50 to 80 carried out by members of the U-M Institute for Firearm Injury Prevention, Injury Prevention Center and Institute for Healthcare Policy and Innovation, along with a colleague from Michigan State University.

The researchers conducted the study because one-third of all firearm-related deaths in the United States occur among people in their 50s, 60s and 70s, with 84% of those deaths resulting from suicide.

Preventing injury and death among older adults, and the children and teens who live with them, has taken on new urgency because of the rise in such incidents in the past decade, the researchers say.

“Just as health care providers and health policymakers have worked to address other preventable causes of injury and death, we hope these findings will inform the effort to reduce the toll of firearm injuries among older adults, while respecting firearm ownership rights,” said study leader Patrick Carter, M.D., a U-M emergency physician who co-directs the U-M Institute for Firearm Injury Prevention and directs the Injury Prevention Center. “This is especially true for older adults experiencing depression, cognitive decline, and other conditions that may increase their risk for firearm injury, as well as those with children and teens living with or visiting them.”

Rebecca Cunningham, M.D., the study’s senior author and U-M vice president for research, added, “Firearm safety is about identifying and reducing risk, and creating policies, programs and education that can help achieve this. Every suicide, every accidental shooting, every homicide is a tragedy that affects far more people than just the person pulling the trigger or getting shot. These new data can help us move forward at the societal and personal level.”

Key findings:

The survey covered a wide range of topics, from firearm ownership and storage practices to attitudes toward specific policies and programs. Respondents were also asked about their own health and the presence of children in the home.

Ownership and storage

• 27% of older adults own at least one firearm, and most of these individuals own more than one. Another 10% say they live with someone who owns a firearm.
• 40% of firearm owners say they regularly store their firearms locked and unloaded, 35% say they store their firearms unlocked and unloaded, and 24% store their firearms loaded and unlocked.
• Storage practices differed by firearm type, with a larger proportion of handgun owners reporting they stored at least one firearm loaded and unlocked, while only 3% of long-gun owners reported keeping their long guns stored loaded and unlocked.
• 69% of those who own firearms cited protection as a reason, while 55% cited target shooting or hunting and 30% cited a constitutional right. (Respondents could choose more than one option.)
• Among those who cited protection as a reason for ownership, only 5% said it was to protect themselves against someone they specifically knew, while most endorsed a general sense they needed the weapon to protect themselves.
• 20% of firearm owners who have children living with them or visiting regularly said they store at least one firearm unlocked and loaded, compared with 35% of firearm owners who do not have children living with them or visiting. Other research has shown that 75% of adolescent suicides involve a gun from the teen’s own home or a relative.

Attitudes toward preventive programs and policies

• Most older adults, both firearm owners and non-firearm owners, said they would be comfortable being asked or counseled about firearm safety by a doctor or other clinician. 69% of firearm owners would be comfortable with healthcare-based screening for firearm ownership, and 63% would be comfortable with receiving counseling about safe firearm storage from a health care provider. The percentages were higher among non-firearm owners, including those who live with a firearm owner.

• “Red flag” laws and programs that allow family members or police to petition courts to restrict firearm access by people they believe to be a danger to themselves or others met with approval from 79% of firearm owners and 89% of non-firearm owners.
• 81% of firearm owners and 92% of non-firearm owners support efforts to remove firearms from the homes of older adults with dementia or confusion.
• 88% of firearm owners and 93% of non-firearm owners support restricting those who are under domestic violence restraining orders from owning or having access to firearms.
• Background checks for all firearm sales, including private ones between individuals, met with support from 85% of firearm owners and 93% of non-firearm owners.

Individual and family characteristics and risk factors

• Firearm owners were more likely to be white, male and veterans than non-firearm owners, and more likely to be in higher income brackets and to live in rural areas outside the Northeast.
• 77% of firearm owners had children living with them, or regularly visiting them, compared with 70% of non-firearm owners.
• 40% of non-firearm owners said that the presence of children in their home influenced their decisions about owning firearms, compared with 20% of those who owned firearms.
• 40% of firearm owners said they had experienced social isolation or lack of companionship in the last year; the survey was taken just before the start of the COVID-19 pandemic. This percentage was much higher (89%) among older firearm owners who rated their physical or mental health as fair or poor.
• 9% of the older firearm owners in the survey met criteria for having depression, which is a risk factor for suicide, compared with 8% of non-firearm owners.

 

 

The study was funded by the National Institutes of Health (DA039341, CE003085).

In addition to Carter and Cunningham, the study’s authors are Eve Losman, M.D., Jessica Roche, M.P.H., Preeti Malani, M.D., Jeffrey Kullgren, M.D., M.S., M.P.H., M.S., Erica Solway, Ph.D., M.P.H., Matthias Kirch, M.S., Dianne Singer, M.P.H,, Maureen Walton, Ph.D., of U-M and April Zeoli, Ph.D., of MSU.

Citation: Firearm ownership, attitudes, and safe storage practices among a nationally representative sample of older U.S. adults age 50 to 80, Preventive Medicine, Vol. 156, March 2022, DOI:10.1016/j.ypmed.2022.106955, https://www.sciencedirect.com/science/article/pii/S0091743522000032#

 

---

JOURNAL

Preventive Medicine

DOI

10.1016/j.ypmed.2022.106955 

METHOD OF RESEARCH

Survey

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Firearm ownership, attitudes, and safe storage practices among a nationally representative sample of older U.S. adults age 50 to 80

Disclaimer: AAAS and EurekAlert! are not res

Better education needed about oral sex disease risk, poll of young people shows

Most teens and young adults underestimate sexually transmitted infection risk, and feel their generation needs better information

Peer-Reviewed Publication

MICHIGAN MEDICINE - UNIVERSITY OF MICHIGAN

Most teens and young adults know it’s possible to catch or spread a sexually transmitted infection by having unprotected oral sex, a new poll shows. But more than half underestimate the level of that risk, including many who focus on avoiding pregnancy risk, the data show.

Just over half (54%) of young people also feel their generation needs more education about the risks of oral sex, and how to reduce those risks by using protective barriers such as dental dams and condoms. One in five also called for more depictions or discussion of protection during oral sex in popular culture to normalize the concept.

The new study is published in the Annals of Family Medicine by a team from the MyVoice text-based poll based at the University of Michigan’s Department of Family Medicine. The study is based on answers from 909 young people across the country with an average age of 19.

Past research has shown that oral sex can transmit herpes, gonorrhea, chlamydia, syphilis, HIV, and human papillomavirus, called HPV for short. In the last two decades, the number of Americans diagnosed with head and neck cancers linked to HPV infection, mainly due to oral sex, has surpassed the number diagnosed with HPV-related cervical cancer linked to vaginal sex. A vaccine against all HPV infections is available for both young women and men, but is not widely used among young men.

On a scale of 1 to 5, with 1 being least risky, 60% rated unprotected oral sex at 1, 2 or 3. But young women were more nearly twice as likely as young men to rate it as a 4 or 5 on the risk scale, while young men were twice as likely to rate it as a 1 or 2. Those who rated it low on the risk scale mostly focused on the lack of pregnancy risk and a lower risk of transmitting an STI compared with unprotected vaginal sex.

“Youth deserve to know the facts about the risks of oral sex,” said Tammy Chang, M.D., M.P.H., M.S., director of MyVoice and an associate professor of family medicine at Michigan Medicine. “It's not just about sexually transmitted infections, but also the risk for cancer later in life. Educating youth about the risks of oral sex today and making protection accessible and easy to use can begin to change the cultural norms around oral sex and save lives.”

The study’s co-first authors are U-M Medical School student Arianna Strome and U-M School of Public Health doctoral student N’dea Moore-Petinak. The study was funded by the Michigan Institute for Clinical & Health Research, the U-M MCubed program, and the Department of Family Medicine.

Citation: Youths’ Knowledge and Perceptions of Health Risks Associated With Unprotected Oral Sex, The Annals of Family Medicine January 2022, 20 (1) 72-76; DOI: DOI:10.1370/afm.2761, https://www.annfammed.org/content/20/1/72

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JOURNAL

The Annals of Family Medicine

DOI

10.1370/afm.2761 

METHOD OF RESEARCH

Survey

SUBJECT OF RESEARCH

People

ARTICLE TITLE

Youths’ Knowledge and Perceptions of Health Risks Associated With Unprotected Oral Sex

Wider-reaching solutions urgently needed to reach realistic 'net zero,' warn researchers

There should be greater investment in using a wider group of experts to make decisions about how the landscape is managed if the UK is to reach climate targets such as net zero, a new report warns.

Reports and Proceedings

UNIVERSITY OF LEICESTER

 

IMAGE: LANDSCAPE VIEW OF WHINLATTER, CUMBRIA. view more 

CREDIT: BETH COLE/UNIVERSITY OF LEICESTER

There should be greater investment in using a wider group of experts to make decisions about how the landscape is managed if the UK is to reach climate targets such as net zero, a new report warns.

Tackling the climate emergency should involve those knowledgeable in the arts, business owners, farmers, landowners, developers and investors, the study says.

The interdisciplinary team of UK researchers have highlighted ‘multiple contradictions’ in the pathways to net zero climate targets and called for wider-reaching solutions to create a more sustainable future.

The Landscape Decisions Programme, led by the University of Leicester, has published a new research report with input from environmental scientists, ecosystem modellers, human geographers, humanities scholars, and other experts from Leicester, Reading, Exeter, Bangor, Leeds, Nottingham, Wales Trinity Saint David, and Robert Gordon universities, plus expertise from Rothamsted Research and the UK Centre for Ecology and Hydrology.

The UKRI-funded report stresses the potential negative impact of existing pathways to net zero climate targets, which include losses in the benefits of biodiversity, human wellbeing and cultural knowledge of the landscape.

The UK government has previously set a net zero target of 2050, through a proposed reduction in greenhouse gas emissions and better management of so-called ‘carbon sinks’ such as peatlands and forests, and with new carbon capture technologies.

Recommendations made by the interdisciplinary group include a greater focus on locally-devolved decisions in land-use solutions, as a one-size-fits all approach to net zero landscape management could be damaging in certain environments.

As well as studying the physical impact of landscape decisions, these should be taken within the full context of the social consequences of these changes; for example, in the case of sudden large-scale changes to farming.

The group do, however, recognise that “swift action is essential, otherwise we head deeper towards an inability to reach net zero carbon targets, contribute to biodiversity collapse and, promote societal disengagement with landscapes”.

Dr Beth Cole is Senior Research Fellow for the Landscape Decisions Programme, based at the University of Leicester, and lead author for the report. She said:

“To reach the net zero goals we need to make some challenging decisions about the way we use, manage, and interact with landscapes in the UK. These landscape decisions are dependent upon many factors including the environmental characteristics, and the geographic location of the land, but in this report, we also consider the wider social framing of these decisions and call for inclusive, place-specific net zero practices within landscapes that support both biodiversity and people.

“Collaborating across disciplines this group of researchers together make a team that is greater than the sum of its parts and who have broken down some of the silos this urgent issue is normally approached from.”

Dr Katharine Earnshaw, a co-author based in the University of Exeter’s Department of Classics and Ancient History, said:

“We have an urgent need to think about the culture of change – not just what could be possible on paper. This means a better consideration of the whole picture: social and ethical ideas – the habits of thinking – alongside empirical evidence, taking account of past, present and future.

“This novel report demonstrates the genuine benefits of working across different subjects and with communities and businesses so that we do not reproduce the inequalities that have led us to this crisis.”

Co-author and natural scientist Professor Simon Willcock, of Rothamsted Research and Bangor University, added:

“Obviously, there is an urgent need to move towards net zero landscape decisions to limit the impacts of climate change. However, landscape changes impact a great variety of things – from the carbon and water cycles to biodiversity and local peoples.

“Only by making interdisciplinary decisions that take these many things into account can we move towards achieving sustainability more broadly – benefiting people and nature. Our report highlights this and provides key recommendations as to how net-zero can be achieved more inclusively.”

Professor Heiko Balzter is a Professor of Physical Geography at the University of Leicester and Director of the Centre for Landscape and Climate Research, and is Chair of the Programme Coordination Team for the UKRI Landscape Decisions Programme. He added:

“Our landscapes in the UK are about to change faster than they have done in a long time. These changes are driven by the urgent need to prevent catastrophic climate change by achieving net zero emissions no later than 2050, reversing the loss of many endangered animal and plant species, as well as improving food security and livelihoods of our farmers. This report highlights some key recommendations for decision-makers on ethical consideration, participatory approaches and the trade-offs and synergies between different goals and interventions.”

‘Landscape Decisions to Meet Net Zero Carbon: Pathways that consider ethics, socio-ecological diversity, and landscape functions’ is available in full at landscapedecisions.org.

Landscape Decisions is a Strategic Priorities Fund (SPF) programme funded by UK Research and Innovation (UKRI).

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DOI

10.25392/leicester.data.19011629 

 

Atheists more likely to hide beliefs if they're women, Republicans, southerners or were previously religious

by Amy McCaig, Rice University

Credit: Unsplash/CC0 Public Domain

Atheists in the United States are more likely to conceal their beliefs if they're women, Republicans, southerners or if they've previously been religious, according to new research from Rice University and West Virginia University.

"Patterns of Perceived Hostility and Identity Concealment among Self-Identified Atheists" appears in a recent edition of Social Forces and was authored by Jacqui Frost and Elaine Howard Ecklund of Rice University and Christopher Scheitle of West Virginia University. The study used survey data from a nationally representative sample of U.S. adults and examined which atheists are more likely to hide their religious identity and why.

While certain atheists were more likely to conceal their identity depending on where they lived or with whom they were affiliated, they were still less likely to conceal their identity when compared to other non-religious groups, such as agnostics or those who simply say they do not have a religion, the researchers wrote.

Frost, a postdoctoral research fellow in sociology and the Religion and Public Life Program at Rice and the study's lead author, said that findings about atheists hiding their religious beliefs aren't surprising. Previous research shows atheists are among the least liked and most distrusted minority groups in the U.S.

"If someone is already in a marginalized group—like women—or are members of a group that is heavily religious—such as Republicans or southern Americans—it stands to reason they are less likely to take on the additional stigma of being an 'out' atheist," she said.

Earlier research has also shown that atheists are more likely to report discrimination on the basis of their atheism in social settings, at school and at work, Frost said.

A 2015 survey from the Pew Research Center found the number of people who claim no religious affiliation had increased to 25%. That raises a question among researchers studying this subject: What can be done to support and protect this growing group of people in the U.S.?

"Our research suggests that openness about one's atheist identity may help combat some of the effects of the stigma they face," said Ecklund, director of the Religion and Public Life Program and a Herbert S. Autrey Professor of Social Sciences at Rice.

"In addition, the ability to gather with fellow atheists may help encourage this openness and provide individuals with a safe place to seek support in the face of discrimination," Scheitle said.

The researchers wrote that their findings are valuable for understanding the many different types of religious discrimination. The work also helps better understand how to address and cope with negative side effects of this mistreatment.New book explores the different—and surprising—types of atheism in science

More information: Jacqui Frost et al, Patterns of Perceived Hostility and Identity Concealment among Self-Identified Atheists, Social Forces (2021). DOI: 10.1093/sf/soab165

Provided by Rice University 

Study finds eDNA 'game-changer' to help protect native animals

by Curtin University

Chronosequences of mining restoration where invertebrate samples were collected. 

Restoration sites shown with the number of years restoration from 1 to 22 years. 

Reference sites shown below. JF, Jarrah Forest; PB, Pilbara; SCP, Swan Coastal Plain.

 Credit: DOI: 10.1111/mec.16375

Curtin University researchers have identified a "game-changing" way of protecting native animals—including pygmy possums, western bush wallabies and Australian painted-snipe birds—using sophisticated DNA technology.

Two research papers, published in Molecular Ecology and Biodiversity and Conservation, examined animals and insects across multiple locations including Western Australia's Pilbara region, Perth region and the Jarrah Forest to find out where the use of DNA metabarcoding—a rapid DNA sequencing tool—would be most effective to monitor restoration.

Lead researcher Dr. Mieke van der Heyde, from Curtin's School of Molecular and Life Sciences, said DNA metabarcoding was a game-changer for monitoring the recovery of insects and animals because it could save time, money and resources.

"Fauna monitoring is often overlooked in restoration efforts because there is an assumption that as long as there are plants, everything else will come back on its own—and this isn't necessarily true," Dr. van der Heyde said.

"The problem is that monitoring fauna is hard, often requiring teams of experts in remote locations for weeks at a time, making it time-consuming and expensive. Tracking down the expertise to identify all the animals can also be difficult."

Dr. van der Hyde said DNA metabarcoding has a per sample cost rather than a per specimen cost, so it can be a cost-effective alternative to monitoring fauna recovery in diverse ecosystems but warned that it is not a 'one-size-fits-all' method.

"We found DNA metabarcoding can show the recovery of insects and plants in woodlands and forests, but not in the arid Pilbara region; and ground-dwelling insects give a better restoration signal than flying insects because they don't travel as far," Dr. van der Heyde said.

"In the arid Pilbara, we could tell the difference between restoration and reference sites using the animals detected from pooled poo samples. The lack of rain makes the droppings last longer and the lack of vegetation makes it much easier to see, especially bird droppings," Dr. van der Heyde said.

"Unfortunately, DNA metabarcoding can only identify animals and insects if we have reference DNA for them in our database. To improve this tool, we need to DNA barcode many more animals if we want accurate, species-level identifications from DNA.

"This technology can drastically improve conservation and restoration efforts for the many species under threat from loss of habitat and changing climates."

The papers are titled "Evaluating restoration trajectories using DNA metabarcoding of ground-dwelling and airborne invertebrates and associated plant communities" and "Scat DNA provides important data for effective monitoring of mammal and bird biodiversity." eDNA provides researchers with 'more than meets the eye'

More information: Mieke Heyde et al, Evaluating restoration trajectories using DNA metabarcoding of ground‐dwelling and airborne invertebrates and associated plant communities, Molecular Ecology (2022). DOI: 10.1111/mec.16375

M. van der Heyde et al, Scat DNA provides important data for effective monitoring of mammal and bird biodiversity, Biodiversity and Conservation (2021). DOI: 10.1007/s10531-021-02264-x

Journal information: Molecular Ecology 

Provided by Curtin University 

ISS experiments to find solutions for cleaning up orbital debris and repairing damaged satellites

by Sara Cody, Massachusetts Institute of Technology

Astrobee is a team of free-flying cube-shaped robots that help astronauts perform routine tasks either autonomously or by remote control. An international research collaboration between researchers at MIT and the German Space Agency used this platform to test a set of algorithms to enable a rendezvous with a tumbling target. Credit: Massachusetts Institute of Technology

In 2002, the European Space Agency launched Envisat, the largest civilian satellite (at the time) to go to low Earth orbit (LEO). For a decade, it observed our planet and sent back valuable data on Earth's climate, tracking the decline of Arctic sea ice and more, until it went dark in 2012. One of the prevailing theories for its demise is that it simply ran out of fuel. As LEO becomes more crowded, Envisat is a school bus-sized example of a growing area of concern in the space domain: orbital debris and the ever-increasing risk of disrupting active satellite missions that would yield outcomes ranging from inconvenient to catastrophic for modern society.

But how do you catch up to an uncooperative object tumbling through space faster than a speeding bullet? An international research collaboration between MIT and the German Space Agency (DLR) completed a series of experiments aboard the International Space Station (ISS) that illuminated a possible path forward to help address this question.

"If we could refuel or repair these tumbling bodies that are otherwise functional, it would be really useful for orbital debris reduction, as long as we can catch up to it. But a close-proximity rendezvous is hard to do if you don't know exactly how your target is moving," says Keenan Albee SM '19, a Ph.D. candidate in aeronautics and astronautics who helped lead the project. "We've assembled a set of algorithms that figures out how the target is tumbling, and then along with other tools that allow us to account for uncertainty, we can produce a plan to get us to the target, despite the tumble."

To test their algorithms in microgravity, the team used NASA's Astrobee robots aboard the ISS as their test bed. Astrobee is a team of three cube-shaped robots that help astronauts perform routine tasks either autonomously or by remote control, such as taking inventory, documenting experiments, or moving cargo, using their electric fan propulsion system as well as their built-in cameras and sensors to move about the station and perform their tasks. The first round of microgravity experiments aboard the ISS in June 2021 tested this set of algorithms both individually and together to enable a successful autonomous rendezvous of a "Chaser" Astrobee robot with a tumbling "Target" Astrobee, which were improved upon and tested again in a successful second session in February 2022.

The MIT project team comprises researchers from the Space Systems Laboratory (SSL) and the Astrodynamics, space Robotics, and Controls Laboratory (ARCLab), including Albee, Charles Oestreich SM '21, and principal investigator Richard Linares, the Boeing Career Development Professor in Aeronautics and Astronautics. The DLR team includes principal investigator Roberto Lampariello, graduate student Caroline Specht, and graduate student Hrishik Mishra.

To test the set of algorithms selected by the TumbleDock/ROAM team, first the “Chaser” Astrobee robot (yellow) observes the movement of a tumbling “Target” robot (blue) using its time-of-flight camera. Using data gathered from its cameras, lidar sensors, and onboard inertial measurement unit, the Chaser develops a model of the Target’s state. From there, the Chaser will create a trajectory to follow, correcting reference errors using robust control. Once the trajectory is completed, the Chaser robot reaches a “mating point” with the Target robot. The result: a successful rendezvous. Credit:Background image courtesy of NASA. Illustration by MIT AeroAstro

The TumbleDock/ROAM project

First, the MIT and DLR research teams identified a series of algorithms, including simultaneous localization and mapping (SLAM), system identification, online motion planning, and model predictive control to test on Astrobee's autonomous robots and software platform to enable autonomous rendezvous. Then, they worked to develop the software and hardware required to experiment on the Astrobee platform. Astrobee's open-source flight software, developed by NASA Ames, was augmented with MIT's testing interface, the Astrobee Science Application Package, to enable low-level autonomy experiments. The TumbleDock/ROAM project was the first of a series of research collaborations out of the SSL/ARCLab to use this interface for algorithm testing on-orbit.

Working in a control room from MIT's campus, the team commanded the first round of microgravity testing with Astrobee. One Astrobee served as the "Chaser," with the goal of performing an autonomous rendezvous with another Astrobee acting as the tumbling "Target." Using data from Astrobee's cameras, lidar sensors, and onboard inertial measurement unit, the observing Chaser developed a model of the tumbling Target's motion and inertial properties, which then informed a nonlinear programming-based trajectory optimization to reach a "mating point," fixed in the rotating Target's frame. This trajectory was then tracked using robust model predictive control. The result: a successful rendezvous.

After the first round of testing, the team continued to refine their software based on lessons learned from seeing their work operate on an actual test bed. According to the students, seeing their experiment operate in an actual test bed rather than a simulation is a game-changer.

"I think it's so important for young roboticists and engineers to actually get their hands dirty on a physical system because you see the actual interactions between bodies in the field and gain a new understanding on parameters you may not have thought were important, but require copious amounts of tuning," says Specht. "Working out the math and simulating it is one thing, but actually putting it on a real system and seeing how that works in the real world is a completely different experience, and it opens your mind to so many different possibilities."

In microgravity experiments conducted aboard the International Space Station using NASA’s Astrobee robot system, a research team from MIT and DLR tested a set of algorithms to enable a successful autonomous rendezvous of a "Chaser" Astrobee robot with a tumbling "Target" Astrobee. The time-lapse on top shows a successful rendezvous in real time, while the time-lapse below shows a trajectory in simulation. Credit: Massachusetts Institute of Technology

After the first test session, the TumbleDock/ROAM team worked closely with both NASA and DLR to make further improvements to their system. DLR developed enhancements to Astrobee's default localization system that complemented additional upgrades created by the team at NASA Ames, with MIT continuing work on system integration and other algorithm overhauls. The final test session in February 2022 put these improvements in estimating the Target's orientation, safely tracking the motion plan to the Target with robustness guarantees, and working with Astrobee's maturing localization system to the test, yielding a number of successful rendezvous maneuvers with differing motion plans.

"Because Astrobee is such a new system, we've had a lot more opportunity to collaborate more closely with the engineers from NASA Ames throughout the entire process than we would have otherwise," says Oestreich. "We've had some unique use cases for their system, so it's been an interesting challenge to work through together and get everyone in the same loop."

Working closely together on this project has also yielded benefits for the agency. NASA used portions of data from their project to improve the Astrobee base localization system and have also incorporated changes into the flight code software, providing crucial inputs to the autonomous rendezvous pipeline that will continue to benefit all future Astrobee users.

Passing the torch

NASA's Astrobee robot system is preceded by SPHERES (Synchronized Position Hold, Engage, Reorient Experimental Satellites), small programmable probes first conceived of by MIT undergraduates and further developed by MIT SSL. The SPHERES satellites launched in 2006 and were operated by SSL and NASA under professors David Miller and Alvar Saenz-Otero until Dec. 31, 2019, when Astrobee took over as the sole microgravity robotics test bed aboard the ISS. ROAM, or Relative Operations for Autonomous Maneuvers, became the umbrella for SSL research projects that focused on developing systems to support satellite proximity operations and is part of the namesake of the TumbleDock/ROAM project team.

Before the TumbleDock/ROAM team commanded their experiment aboard the ISS from Earth, they ran through rendezvous maneuvers in simulation.

 Credit: Massachusetts Institute of Technology

"Our project achieved multiple on-orbit firsts both for MIT and for Astrobee, which is really exciting," says Albee. "We were the first Astrobee payload to perform simultaneous complex control of multiple robots and the first to perform low-level planning and control autonomy research using the Astrobee system. It was also the first time the SSL commanded an ISS payload directly and in real time from MIT's campus."

In addition to building the systems, the research teams at MIT and DLR collaborated on operations, experiments, and testing, leveraging the work done previously in SPHERES to enable this new application with Astrobee. When Lampariello first met David Miller, the Jerome C. Hunsaker Professor and former director of the SSL at MIT, he proposed a research project to test his motion planning software for tumbling targets on the SPHERES system. This initial collaboration eventually led to the TumbleDock/ROAM project on Astrobee.

"This project brings together the work my lab has done in motion planning and the work in perception that MIT has developed. Together, we all worked to develop the controls required to test the hardware," says Lampariello. "By the time we ran the tests aboard the ISS, we had a whole pipeline of functionalities—perception, motion prediction, planning, and control—to demonstrate on the Astrobee platform."

According to Oestreich, the TumbleDock/ROAM project not only builds on a foundation of knowledge and collaboration from SPHERES, but also on a legacy of generations of graduate work in SSL that came before them.

"The SLAM and target estimation algorithms, which help with the initial stage of finding out how the target is tumbling, were developed by graduate students in SSL and have been handed down through generations of us now," says Oestreich. "It's been interesting to see how it has evolved over the past eight years from thesis to thesis as each person worked to advance its capabilities further, and it has been cool to be able to implement it on new hardware like Astrobee."

In the process of building and refining their Astrobee experiment, they found the interface they developed could be adapted and repurposed for other investigations. Looking ahead, the TumbleDock/ROAM team hopes to make Astrobee as useful for other researchers as SPHERES was for them. The team has already run another set of experiments, RElative Satellite sWArming and Robotic Maneuvering (ReSWARM), in collaboration with KTH Space Center in Sweden and IST at the University of Lisbon in Portugal. The ReSWARM experiments successfully demonstrated a variety of algorithms related to on-orbit assembly and servicing, including information-aware motion planning and distributed model predictive control of microgravity robot teams. While MIT is currently one of the most prolific users of the Astrobee platform, the project team plans to continue refining their work with the goal to make testing resources open source for other researchers at MIT and beyond.

Explore further

Astrobee's first robot completes initial hardware checks in space
More information: Keenan Albee et al, A Robust Observation, Planning, and Control Pipeline for Autonomous Rendezvous with Tumbling Targets, Frontiers in Robotics and AI (2021). DOI: 10.3389/frobt.2021.641338

Provided by Massachusetts Institute of Technology