Wednesday, July 28, 2021

Another byproduct of the pandemic: paranoia

The COVID-19 pandemic increased our feelings of paranoia, particularly in states where wearing masks was mandated, a new Yale study has shown. That heightened paranoia was particularly acute in states where adherence to mask mandates was low, the researchers report July 27 in the journal Nature Human Behaviour.

Increased feelings of paranoia were also associated with greater acceptance of conspiracy theories, the researchers found.

"Our psychology is massively impacted by the state of the world around us," said Phil Corlett, associate professor of psychology and senior author of the study. "From a policy standpoint, it is clear that if a government sets rules, it is important that they are enforced and people are supported for complying. Otherwise they may feel betrayed and act erratically."

Corlett and his colleagues were already studying the role uncertainty plays in the development of paranoia in individuals as the pandemic began in early 2020. In those early experiments, the Yale team measured the volatility of peoples' choices during a simple card game in which rules could suddenly change, provoking a rise in paranoia for participants. Some people literally thought the deck was stacked against them and changed their choices frequently, even when similar choices had led to beneficial outcomes previously.

"We continued to gather data through lockdown and into reopening," Corlett said. "It was one of those rare, serendipitous incidences where we were able to study what happens when the world changes rapidly and unpredictably."

The baseline data collected on paranoia revealed the psychological impact of the pandemic.

Using online surveys and the same card games, the researchers found increased levels of paranoia and choice volatility among the general population. They also investigated the effect of public health policy choices on peoples' sentiments in states where masks were mandated and those where masks were simply recommended. In their analysis they also evaluated prior research on regional differences in how strongly people feel about following rules.

Paranoia and erratic choice behavior were higher in states where masks were mandated than in those that had looser restrictions. But scores were highest in areas where adherence to the rules were the lowest and where some people felt most strongly that rules should be followed.

"Essentially people got paranoid when there was a rule and people were not following it," Corlett said.

The researchers also found that people who were more paranoid were more likely to endorse conspiracies about mask-wearing and potential vaccines, as well as the QAnon conspiracy theory, which posits, among other ideas, that the government is protecting politicians and Hollywood entertainers who are running pedophile rings across the country.

Corlett said there are many historical precedents for a rise in conspiracy theories during times of trauma, from a prevalent belief that medieval bubonic plague outbreaks were caused by Jews poisoning well water to the "9/11 Truth" movement which contended that the 2001 terror attacks were orchestrated by the U.S. government.

"In times of trauma and great change, sadly, we have a tendency to blame another group," he said.

Unexpected uncertainty can breed paranoia, researchers find

More information: Praveen Suthaharan et al, Paranoia and belief updating during the COVID-19 crisis, Nature Human Behaviour (2021). DOI: 10.1038/s41562-021-01176-8

Journal information: Nature Human Behaviour

Provided by Yale University

Premature birth associated with 'profound reduction' in brain connections

by King's College London

Researchers from the £12 million Developing Human Connectome Project have used a novel type of medical imaging to show how different areas of a newborn baby's brain communicate with each other.

Published today in Brain, the study used magnetic resonance images (MRI) with unprecedented resolution from more than 300 healthy babies to define how healthy babies' brains are connected, then researchers could assess whether particular clinical risks affected brain development.

They found that in healthy infants born at the right time, connectivity between the brain areas controlling basic functions like sensation and movement was quite similar to that seen in the adult brain. Also, the visual system develops rapidly, probably related to the sudden richness of visual experience after birth.

Communication between parts of the brain linked with more sophisticated functions like decision-making and executive function was relatively reduced compared to adults.

One of the senior researchers Dr. Dafnis Batallé said it was found premature birth was associated with a profound reduction in connectivity between many brain regions, and with a reconfiguration of the organization of functional brain networks.

"The findings can improve clinical understanding of how a baby's brain develops and may provide a way to identify subtle alterations leading to problems later in life. Early identification of babies at an increased risk is important in order to develop potential therapeutic strategies. In the future we hope to identify infants that may benefit of targeted interventions as early as few weeks after birth in order to improve their quality of life," says Dr. Dafnis Battale.

"It is great to see that the combination of advanced image analysis tools and open datasets such as the developing Human Connectome Project can offer a new glimpse into how the brain organizes itself during development," says Professor Daniel Rueckert, Imperial College London.

The Developing Human Connectome Project is led by King's College London in collaboration with Oxford University and Imperial College and funded by the European Research Council.

It is providing high resolution magnetic resonance brain images from around 1000 unborn and newborn babies to scientists worldwide to support a large number of world-leading research projects into brain development and cerebral or mental health disorders.

800 newborn brain scans made available to help clarify how some diseases develop

More information: Michael Eyre et al, The Developing Human Connectome Project: typical and disrupted perinatal functional connectivity, Brain (2021). DOI: 10.1093/brain/awab118

Journal information: Brain

Provided by King's College London

Epicureanism

Eating for hunger or pleasure? Regulating these feeding behaviors involves different brain circuits

by Baylor College of Medicine

Many times we eat, not because we are hungry, but because of social pressures or because the food is so appetizing, that, even though we are full, we just want another bite.

Overeating, whether it is guided by hunger or pleasure, typically leads to obesity, which affects about 42% of the adults in the U.S., according to the Centers for Disease Control and Prevention. Looking to contribute to the development of effective treatments for obesity, an international team led by researchers at Baylor College of Medicine investigated in an animal model how the brain regulates feeding triggered by hunger or other factors.

Led by Dr. Yong Xu, professor of pediatrics—nutrition and molecular and cellular biology at Baylor, the team discovered that although the brain regulates both types of feeding behavior through serotonin-producing neurons in the midbrain, each type of feeding is wired by its own independent circuit that does not influence the other type of feeding. The researchers also identified two serotonin receptors and two ion channels that can affect the feeding behaviors, opening the possibility that modulating their activities might help regulate overeating. The study appears in the journal Molecular Psychiatry.

Mapping the roads that control feeding behavior in the brain

Xu and his colleagues identified two distinct brain circuits formed by serotonin-producing neurons in the midbrain. One of the circuits extends to the hypothalamus, while the other projects into another region of the midbrain. These circuits play very distinct roles in regulating feeding.

"We discovered that the circuit that projects to the hypothalamus primarily regulates hunger-driven feeding, but does not influence the non-hunger driven feeding behavior," Xu said. "The other circuit that projects into the midbrain regulates primarily the non-hunger driven feeding, but not the feeding behavior triggered by hunger. This indicates that, at the circuit level, the brain wires the two types of feeding behavior differently."

The other significant contribution of this work refers to the identification of potential molecular targets associated with the circuits that could be used to treat overeating.

"One potential target is serotonin receptors, which are molecules that mediate the functions of the neurotransmitter serotonin produced by the neurons," Xu explained. "We found that two receptors, serotonin 2C receptor and serotonin 1B receptor, are involved in both types of feeding behavior. Our data suggests that combining compounds directed at both receptors might produce a synergistic benefit by suppressing feeding."

In addition, the team identified ion channels associated with the circuits that also might offer an opportunity to regulate the feeding behaviors. "One is the GABA A receptor, a chloride channel, found to be important in regulating serotonin circuits during hunger-driven feeding, but not during non-hunger driven feeding," Xu said.

The other is a potassium channel that influences feeding triggered by hunger-independent cues, but not hunger-driven feeding. "There is a clear segregation of these two ion channels," Xu said. "They have distinct functions in feeding behavior, which suggests they also could be target candidates to regulate overeating."

The findings have encouraged the researchers to conduct future studies to identify more molecules that could modulate the activity of the ion channels to produce anti-overeating effects in animal models. "We also want to explore how external factors related to nutrition might affect ion channel functions at the molecular level," Xu said.

This brain circuit signals when to stop eating; could regulating it help with obesity

More information: Yanlin He et al, 5-HT recruits distinct neurocircuits to inhibit hunger-driven and non-hunger-driven feeding, Molecular Psychiatry (2021). DOI: 10.1038/s41380-021-01220-z

Journal information: Molecular Psychiatry

Provided by Baylor College of Medicine

Founding Father' of lithium-ion batteries helps solve 40-year problem with his invention

by Paul Boisvert, Oak Ridge National Laboratory

In the late 1970s, M. Stanley Whittingham was the first to describe the concept of rechargeable lithium-ion batteries, an achievement for which he would share the 2019 Nobel Prize in Chemistry. Yet even he couldn't have anticipated the complex materials science challenges that would arise as these batteries came to power the world's portable electronics.

One persistent technical problem is that every time a new lithium-ion battery is installed in a device, up to about one-fifth of its energy capacity is lost before the device can be recharged the very first time. That's true whether the battery is installed in a laptop, camera, wristwatch, or even in a new electric vehicle.

The cause is impurities that form on the nickel-rich cathodes—the positive (+) side of a battery through which its stored energy is discharged.

To find a way of retaining the lost capacity, Whittingham led a group of researchers that included his colleagues from the State University of New York at Binghamton (SUNY Binghamton) and scientists at the Department of Energy's (DOE's) Brookhaven (BNL) and Oak Ridge National Laboratories (ORNL). The team used x-rays and neutrons to test whether treating a leading cathode material—a layered nickel-manganese-cobalt material called NMC 811—with a lithium-free niobium oxide would lead to a longer lasting battery.

The results of the study, "What is the Role of Nb in Nickel-Rich Layered Oxide Cathodes for Lithium-Ion Batteries?" appear in ACS Energy Letters.

"We tested NMC 811 on a layered oxide cathode material after predicting the lithium-free niobium oxide would form a nanosized lithium niobium oxide coating on the surface that would conduct lithium ions and allow them to penetrate into the cathode material," said Whittingham, now a SUNY distinguished professor and director of the Northeast Center for Chemical Energy Storage (NECCES), a DOE Energy Frontier Research Center led by SUNY Binghamton.

Lithium batteries have cathodes made of alternating layers of lithium and nickel-rich oxide materials (chemical compounds containing at least one oxygen atom), because nickel is relatively inexpensive and helps deliver higher energy density and greater storage capacity at a lower cost than other metals.

But the nickel in cathodes is relatively unstable and therefore reacts easily with other elements, leaving the cathode surface covered in undesirable impurities that reduce the battery's storage capacity by 10-18% during its first charge-discharge cycle. Nickel can also cause instability in the interior of the cathode structure, which further reduces storage capacity over extended periods of charging and discharging.

To understand how the niobium affects nickel-rich cathode materials, the scientists performed neutron powder diffraction studies at the VULCAN engineering materials diffractometer at ORNL's Spallation Neutron Source (SNS). They measured the neutron diffraction patterns of pure NMC 811 and niobium-modified samples.

"Neutrons easily penetrated the cathode material to reveal where the niobium and lithium atoms were located, which provided a better understanding of how the niobium modification process works," said Hui Zhou, battery facility manager at NECCES. "The neutron scattering data suggests the niobium atoms stabilize the surface to reduce first-cycle loss, while at higher temperatures the niobium atoms displace some of the manganese atoms deeper inside the cathode material to improve long-term capacity retention."

The results of the experiment showed a reduction in first-cycle capacity loss and an improved long-term capacity retention of greater than 93 percent over 250 charge-discharge cycles.

"The improvements seen in electrochemical performance and structural stability make niobium-modified NMC 811 a candidate as a cathode material for use in higher energy density applications, such as electric vehicles," said Whittingham. "Combining a niobium coating with the substitution of niobium atoms for manganese atoms may be a better way to increase both initial capacity and long-term capacity retention. These modifications can be easily scaled-up using the present multi-step manufacturing processes for NMC materials."

Whittingham added that the research supports the objectives of the Battery500 Consortium, a multi-institution program led by the DOE's Pacific Northwest National Laboratory for the DOE Office of Energy Efficiency and Renewable Energy. The program is working to develop next-generation lithium-metal battery cells delivering up to 500-watt hours per kilogram versus the current average of about 220-watt hours per kilogram.

New class of cobalt-free cathodes could enhance energy density of next-gen lithium-ion batteries

More information: Fengxia Xin et al, What is the Role of Nb in Nickel-Rich Layered Oxide Cathodes for Lithium-Ion Batteries? ACS Energy Letters (2021). DOI: 10.1021/acsenergylett.1c00190

Provided by Oak Ridge National Laboratory

Study: New reusable shock absorber shows promise in lab tests

by Cory Nealon, University at Buffalo

University at Buffalo engineers are reporting a new energy dissipation device that they say could have far-reaching applications in transportation safety.

Described in the International Journal of Mechanical Sciences, the device utilizes low-cost metallic materials and a simple design. Unlike conventional sacrificial structural components like car bumpers, it's designed to be reused after impact.

"Most energy absorbers carrying high stiffness work by crushing or collapsing upon impact. This reduces physical damage to the vehicle, or whatever the absorbers are protecting, but it requires the replacement of internal and external parts following the collision," says the study's senior author, Jongmin Shim, Ph.D., associate professor of structural engineering in the UB School of Engineering and Applied Sciences.

"Our structure is unique in that it enables impact energy to detour around the vehicle. It's comprised of one column with a flange at each end. These flanges have hinges that allow the normally rigid column to snap out of place, which converts external energy into kinetic energy of the disconnected column, eventually protecting the vehicle," he adds.

Study co-author Seoyoung Heo, Ph.D., is a former graduate student in Shim's lab.

"The device is engineered to have both high stiffness—the ability to bear loads and resist collapsing—as well as high damping, which means it can dissipate energy," she says. "Its potential applications are varied, everything from automobiles and ship buffers to helicopters, drones and more."

The researchers conducted tests of the device, made of steel, on examples measured by centimeters. Because of its simple design and common materials, they say, it could easily be scaled up or down to other dimensions.

Shim and Heo are co-inventors on a provisional patent application filed by UB with the U.S. Patent and Trademark Office for the device. The technology is available for licensing through the UB Technology Transfer office.

Unique technology gives humans a leg up on walking

More information: Seoyoung Heo et al, Weakening-induced Snap Instability as a Novel Reusable Force Protection Mechanism, International Journal of Mechanical Sciences (2021). DOI: 10.1016/j.ijmecsci.2021.106645

Provided by University at Buffalo

Trapping is city-dwellers' preferred form of backyard conservation

by Victoria University of Wellington

Backyard trapping of rats and other pests is by far more popular as a conservation activity in urban areas than monitoring pests or native wildlife, according to Te Herenga Waka—Victoria University of Wellington research just published in the journal People and Nature.

"We were interested in whether different backyard conservation activities appealed to different sorts of people in Aotearoa New Zealand and what motivated them to take part," says lead author Dr. Chris Woolley, a postdoctoral researcher at Zealandia—Centre for People and Nature in Wellington and a member of the team from the University's Te Tumu Whakaoho Mauri o te Ao Koiora—Centre for Biodiversity and Restoration Ecology (CBRE) that conducted the study.

Understanding what makes people want to take part in different nature-based activities is important for understanding how to get them involved and the sort of projects most likely to interest them, says Dr. Woolley.

Undertaken for the Ministry of Business, Innovation and Employment-funded People, Cities and Nature program, to which the CBRE contributes, the study investigated three main activities: pest mammal trapping and recording sightings of both native and pest species—all common ways in which urban-dwelling New Zealanders engage in backyard conservation.

"But there are some important differences," says Dr. Woolley. "Pest mammal trapping is a concrete action done to achieve a goal that will directly benefit native biodiversity. Monitoring activities, however, are examples of conservation citizen science—one (native biodiversity monitoring) collecting data to measure positive outcomes achieved; the other (pest mammal monitoring) measuring the presence or absence of a barrier to the former. Because of these differences, we wondered if the activities might appeal to different types of people."

In the study, 264 people—some self-selected and others reached by door knocking—responded to questions about how willing they would be to undertake the three activities.

"We wanted to know what motivated backyard conservation action and what barriers people felt prevented them from taking part," says Dr. Woolley.

Just over half the people said they had at some time taken part in native biodiversity monitoring, pest mammal monitoring and/or pest mammal trapping. Backyard pest trapping was by far the most commonly reported of the three activities.

People with a higher level of connection to nature were more willing to take part in all the activities. The link between connection to nature and a willingness to engage suggests that, in New Zealand, investing in programs that help improve people's connection to nature in urban areas might increase participation in conservation activities.

"People cited a number of different barriers to participation, including lack of knowledge and motivation," says Dr. Woolley. "Concern for the safety of children and pets was reported as a barrier more frequently for pest trapping than pest monitoring—and animal welfare concerns, cost and dealing with dead animals were an issue."

Lack of time and of a suitable environment were also seen as barriers to participation in each of the conservation activities.

"What this suggests is that—when developing conservation activities involving public participation—the ways in which you communicate the outcomes of the activity will be important in encouraging participation. Monitoring might be for people with an interest in natural history who can then get feedback on their observations," says Dr. Woolley.

The survey results also suggested a pro-environmental attitude has less influence on people's willingness to trap than for the other activities, indicating the popularity of trapping may be driven by other factors—perhaps a perception of rodents as household pests.

"We expected that community and social motivations might be positively associated with pest trapping, as, anecdotally, this activity seems to provide opportunities for the community to get to know one another," write the authors, who also include CBRE director Associate Professor Stephen Hartley, Professor Nicola Nelson, head of the University's Te Kura Mātauranga Koiora—School of Biological Sciences, of which the CBRE is part, and Zealandia conservation manager Dr. Danielle Shanahan.

"Instead, these relationships existed for the monitoring activities but not for trapping. This indicates that although people who engage in pest trapping may enjoy social opportunities as a result of taking part, this is unlikely to be a factor motivating their initial participation."

"Ironically," says Dr. Woolley, "for those who prefer trapping, success from a conservation point of view is when you're not trapping anything because there's nothing to be trapped! That's where you need the monitoring and in a large project ideally you'd do all three methods."

Providing easy-to-use traps and more information and publicity about trapping will also help get people involved, say the researchers, who think these sorts of activities may act as a gateway, encouraging people with low conservation values to begin a path towards greater environmental stewardship.

Research has implications for New Zealand bird conservation

More information: Christopher K. Woolley et al, Public willingness to engage in backyard conservation in New Zealand: Exploring motivations and barriers for participation, People and Nature (2021). DOI: 10.1002/pan3.10243

Provided by Victoria University of Wellington

New strategy for drug design: Keeping copper atoms closer to keep bacteria away

by Tokyo University of Science

The discovery of antibiotics was a huge breakthrough in medicine, which helped save countless lives. Unfortunately, their widespread use has led to the rapid evolution of highly resistant bacterial strains, which threaten to take humanity back to square one in the fight against infectious diseases. Even though researchers are seeking new design concepts for antibacterial drugs, the overall development of new agents is currently on the decline.

To tackle this serious problem, scientists at Tokyo University of Science, Japan, are exploring a novel approach to boost the in vivo antibacterial activity of hydrogen peroxide (H2O2), a commonly used disinfectant. In a recent study published in Macromolecular Rapid Communications, a team led by Assistant Professor Shigehito Osawa and Professor Hidenori Otsuka reported their success in enhancing H2O2 activity using carefully tailored copper-containing polymers.

To understand their approach, it helps to know how H2O2 acts against bacteria in the first place, and the role that copper plays. H2O2 can be decomposed into a hydroxyl radical (OH) and a hydroxide anion (OH−), the former of which is highly toxic to bacteria as it readily destroys certain biomolecules. Copper in its first oxidation state, Cu(I), can catalyze the splitting of H2O2 into a hydroxyl radical and a hydroxide anion, turning into Cu(II) in the process through oxidation. Curiously, H2O2 can also catalyze the reduction of Cu(II) to Cu(I), but only if this reaction is somehow facilitated. One way to achieve this is to have Cu(II)-containing complexes get close enough together.

However, when using Cu(II)-containing complexes dissolved in a solution, the only way for them to come close together is by accidentally bumping into each other, which requires an excessively high concentration of copper. The team found a workaround to this issue by drawing inspiration from cellular chemistry, as Dr. Osawa explains: "In living organisms, copper forms complexes with proteins to efficiently catalyze redox reactions. For example, tyrosinase has two copper complex sites in close proximity to each other, which facilitates the formation of reaction intermediates between oxygen species and copper complexes. We thought we could leverage this type of mechanism in artificially produced polymers with copper complexes, even if dispersed in a solution."

With this idea, the researchers developed a long polymer chain with dipicolylamine (DPA) as copper-containing complexes. These DPA–copper complexes were attached to the long polymer backbone as "pendant groups." When these polymers are dispersed in a solution, the Cu(II) atoms in the pendant groups are kept in close proximity and locally high densities, vastly increasing the chances that two of them will be close enough to be reduced to Cu(I) by H2O2. Through various experiments, the scientists demonstrated that the use of these tailored polymers resulted in higher catalytic activity for the splitting of H2O2, resulting in more OH even for lower concentrations of copper. Further tests using Escherichia coli cultures showed that these polymers greatly enhanced the antibacterial potential of H2O2.

While the results of this study open up a new design avenue for antimicrobial drugs, there may also be useful applications in the food industry as well. "Because copper is an essential nutrient for living organisms, the antibacterial agent developed in this study holds promise as an efficient food preservative, which could contribute to increasing the variety of foods that can be preserved over long shelf times," highlights Dr. Osawa. Let us hope this new strategy makes it easier for us to keep microscopic menaces at bay.

Converting P450 peroxygenase into peroxidase via mechanism-guided protein engineering

More information: Shigehito Osawa et al, Accelerated Redox Reaction of Hydrogen Peroxide by Employing Locally Concentrated State of Copper Catalysts on Polymer Chain, Macromolecular Rapid Communications (2021). DOI: 10.1002/marc.202100274

Journal information: Macromolecular Rapid Communications

Provided by Tokyo University of Science

Balancing nitrogen for sunflowers

by American Society of Agronomy

Sunflowers have many uses. They are used for floral arrangements, animal feed, biofuels, and even food for us.

When grown commercially by farmers, the quality of sunflowers is based on the oil and protein concentrations in the seeds.

Sunflower oil can be used for cooking and can be made into biofuels. The protein from sunflowers is important in sunflower products like animal pellets and protein powders.

To grow quality sunflowers with a high nutritional value, farmers need to ensure the sunflowers have access to nutrients in the soil. One of the most important nutrients for sunflowers is nitrogen.

Sunflowers cannot survive without nitrogen, but too much can be a problem. Too much nitrogen can actually decrease the oil concentration in seeds, which decreases the quality of the crop.

Nahuel Reussi Calvo is a scientist in Argentina who studies sunflowers. His research aims to determine the best rate of nitrogen fertilizer that will grow high-quality sunflowers. The results were recently shared in Agronomy Journal, a publication of the American Society of Agronomy.

Finding the best nitrogen fertilizer rate has benefits beyond sunflower yields. It also minimizes the economic and environmental costs of applying fertilizer.

Modern varieties of sunflower can produce more oil and protein, but they require more nitrogen to do so.

Traditionally, scientists measure nitrogen available for sunflowers by taking soil samples before planting. However, the target nitrogen levels for these tests are not up-to-date to match the needs of modern sunflowers.

Researchers set out to determine if there were better ways to determine how much nitrogen the sunflowers need. They tested a few different methods.

First, Reussi Calvo and the team used the traditional soil sample analysis method combined with another soil sample analysis. The extra soil sample helps determine the amount of nitrogen provided in the soil when organic matter naturally breaks down.

The next method took place during the growing season. The team used sensors to measure leaf greenness at different growth stages. This is a test that has proved successful for measuring nitrogen content in crops like wheat, barley, corn, and potato.

After harvest, the team used sunflower seeds to measure grain nitrogen concentration for the third method. This is a useful tool for predicting the nutritional value of crops like corn, wheat, rice, and cotton.

Researchers determined the three new methods for measuring nitrogen for sunflowers were better than the traditional soil sample analysis method. Leaf greenness sensors were a promising tool for monitoring nitrogen during the growing season. The grain nitrogen concentration successfully diagnosed nitrogen deficiencies.

Argentina is the fourth largest sunflower producer in the world, but the average yield is much lower than other countries. By updating nitrogen recommendations for sunflower crops, scientists can decrease the yield gap and improve sunflower grain quality.

The next steps in this research will be to repeat the study on farms with different soil types, management practices, and levels of other nutrients like phosphorus and sulfur.

Sunflowers found to share nutrient-rich soil with others of their kind

More information: Sergio Tovar Hernandez et al, Assessment of nitrogen diagnosis methods in sunflower, Agronomy Journal (2021). DOI: 10.1002/agj2.20685

Journal information: Agronomy Journal

Provided by American Society of Agronomy

Oral biome change during shift from foraging to farming not as dramatic as in recent years

Disarticulated mandible x.11 in context U64 (c. 6750--6450 cal BC) from the Mesolithic site of Vlasac, Serbia. Credit: Dušan Boric

A team of researchers affiliated with several institutions in Italy, the US and Austria has found that changes to the human oral biome during the shift from foraging to farming were not nearly as dramatic as those that have occurred in modern times. In their paper published in Proceedings of the National Academy of Sciences, the group describes their analysis of dental records covering thousands of years and what it showed them about changes to the microbiome in the human mouth.

Modern humans began the transition from foraging to farming during the Neolithic—at the end of the Stone Age, approximately 10,000 years ago. In this new effort, the researchers wondered if the oral microbiome of people changed as people began eating more food they grew themselves. To find out, they conducted an extensive DNA analysis of dental calculus (mineralized plaque) from the remains of 28 ancient people found in what is now the Danube Gorges region which covers parts of Croatia and Romania—along with 10 samples from people who once lived in central Italy and a dozen from people who once lived in what is now northwestern Italy. The age of the specimens ran from the Neolithic all the way to the Middle Ages.

In looking at their data, the researchers found that the gradual change to farming did not impact the human oral biome in any significant way. The most noticeable was an uptick in microbes of the 807-oral taxon—which diversified geographically—as well as the discovery that Streptococcus sanguinis became more common in foragers during the Mesolithic. Also, they saw that the Anaerolineaceae bacterium became more diverse and, in some cases, displaced other variants. They also noticed slight differences in multiple species between people who lived in Italy and those who lived in the Balkans. None of the changes they saw came close, however, to the changes that have occurred in the much more recent past—since antibiotics have been introduced into the oral biome. Antibiotic resistance in microbes has led to significant evolutionary changes.

Explore further Ancient oral biome points to overall health

More information: Claudio Ottoni et al, Tracking the transition to agriculture in Southern Europe through ancient DNA analysis of dental calculus, Proceedings of the National Academy of Sciences (2021). DOI: 10.1073/pnas.2102116118

Scientist aids in ID of child in the state's oldest cold case

by Kristin Strommer, Museum Of Natural and Cultural History, University of Oregon

A toddler who was found dead in Oregon 58 years ago has finally been identified, thanks to a concerted effort involving local, state and national law enforcement, genetic genealogists and a University of Oregon scientist.

Jeanne McLaughlin, an osteologist and forensic anthropologist at the Museum of Natural and Cultural History, was called to assist with the case beginning in 2008, after the Jackson County Sheriff's Office exhumed the body in order to obtain a DNA sample. Osteology is the study of the skeleton and bones.

First discovered in 1963 by a fisherman at Keene Creek Reservoir in Southern Oregon, the child's body was found wrapped in blankets and wire and weighted down with iron molds. Despite efforts by generations of investigators, the Baby Doe's identity remained unknown for decades, becoming the oldest unidentified person case in the state.

All that all changed in June, when the Jackson County Sheriff's Office announced its conclusion that Baby Doe was 2-year-old Steven Crawford, a missing child who had been born in New Mexico in 1960.

"Advances in DNA science were central to solving the case," McLaughlin said.

Following exhumation, McLaughlin helped the investigative team develop a more precise biological profile. Beginning with a round of X-rays, she looked for signs of trauma and other clues about the child's life and death, but she and the team soon determined that they needed more information than X-rays could reveal. So she processed the remains down to a skeleton, which enabled closer examination, extraction of a DNA sample and development of a digital facial reproduction.

Her analysis of the skeleton led McLaughlin to expand the initially assigned age range from 2 years to between 18 months and 2 1/2 years. Her examination also revealed that the child had some distinct features, including two fused teeth and a unique skull shape, which suggested he may have lived with a genetic syndrome.

"Down syndrome was at the top of the list, though we couldn't entirely rule out others without further genetic testing," McLaughlin said.

The DNA was compared across national databases of missing and unidentified persons, but the lead went cold when no matches were found.

"Cold cases typically go in spurts and stalls. You get some new tip or some new technology comes along that breathes life into the case and then you go into a waiting period again," said McLaughlin, who has worked on investigations around the state and the country.

The Baby Doe case finally got its big break in 2020, when the Jackson County Sheriff's Office received a tip through one of its social media accounts and reopened the investigation. The investigative team soon submitted another biological sample, this time in hopes of generating new leads through DNA.

"This time it paid off," McLaughlin said. "The genealogy was the ticket."

CeCe Moore, a genetic genealogist at Parabon NanoLabs, searched an open-source DNA repository and located two potential siblings of the unidentified toddler. A subsequent interview with a half-brother in Ohio revealed that he had a younger brother with Down syndrome who'd gone missing decades prior. Soon after, investigators located Stevie Crawford's birth certificate.

"Since then, many more family members have been located, and the family has been very involved since the identification was made," McLaughlin said.

She noted that families often experience relief when a missing person case finally resolves.

"They have an answer," she said. "Not knowing has to be the worst kind of torture. I can't imagine hearing, after 58 years, "Here's your loved one. We know where he is, we know a little bit about what happened.'"

McLaughlin commended the efforts of the many people involved in the case over the years, noting the longevity of the investigation and the ongoing energy put into the case.

"It had been through multiple teams of investigators spanning three generations, but cases like these stick with you," she said. "Investigators stay invested. And this case in particular showcases what can happen when everyone comes together for a common cause."

New 3-D technology raises hopes for the coldest of cold cases

Provided by University of Oregon

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