Earlier mammograms for women with family history of breast cancer may not be needed

A new study released in the American Cancer Society journal Cancer reconsiders guidelines for when to start screening with mammograms if a woman has a mother, sister, or daughter who was diagnosed with breast cancer.

Women with a first-degree family relative diagnosed with breast cancer, who are otherwise at average risk, are often advised to get screened 10 years earlier than the relative's diagnosis age. However, there is little evidence to support the long-standing recommendation.

UC Davis Comprehensive Cancer Center researcher Diana Miglioretti joined Danielle Durham, with the Department of Radiology at University of North Carolina at Chapel Hill, and five other researchers on the study. They analyzed data from the Breast Cancer Surveillance Consortium on screening mammograms conducted from 1996-2016 to evaluate when screenings should begin for women with a family history of breast cancer.

More than 300,000 women were included in the national study. Researchers compared cumulative 5-year breast cancer incidence among women with and without a first-degree family history of breast cancer by relative's age at diagnosis and screening age.

"The study concluded that a woman with a relative diagnosed at or before age 45 may wish to consider, in consultation with her doctor, initiating screening 5-8 years earlier than their relative's diagnosis age, rather than a decade earlier. That puts them at a risk that is equal to that of an average-risk woman who is age 50, which is the most recommended age for starting mammograms," said Durham.

BRCA gene mutation carriers may benefit from starting screenings earlier. Women ages 30-39 with more than one first-degree relative diagnosed with breast cancer may wish to consider genetic counseling.

Increasing the age for initiating screening could reduce the potential harms of starting breast cancer screenings too early. These include increased radiation exposure and false positive results that require women to return to the clinic for diagnostic imaging and possibly invasive procedures, but do not result in a breast cancer diagnosis. The earlier a woman starts receiving mammograms, the more screenings they will undergo over their lifetime -- and that increases the chances of experiencing these harms.

"Mammography also may not perform as well in younger women because they are more likely to have dense breasts which increase the difficulty of finding cancer on the images and results in more false-positives," Miglioretti said.

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Why late-night eating leads to weight gain, diabetes

Northwestern Medicine scientists have uncovered the mechanism behind why eating late at night is linked to weight gain and diabetes.

The connection between eating time, sleep and obesity is well-known but poorly understood, with research showing that over-nutrition can disrupt circadian rhythms and change fat tissue.

New Northwestern research has shown for the first time that energy release may be the molecular mechanism through which our internal clocks control energy balance. From this understanding, the scientists also found that daytime is the ideal time in the light environment of the Earth's rotation when it is most optimal to dissipate energy as heat. These findings have broad implications from dieting to sleep loss and the way we feed patients who require long-term nutritional assistance.

The paper, "Time-restricted feeding mitigates obesity through adipocyte thermogenesis," will be published online today, and in print tomorrow (Oct. 21) in the journal Science.

"It is well known, albeit poorly understood, that insults to the body clock are going to be insults to metabolism," said corresponding study author Dr. Joseph T. Bass, the Charles F. Kettering Professor of Medicine at Northwestern University Feinberg School of Medicine. He also is a Northwestern Medicine endocrinologist.

"When animals consume Western style cafeteria diets -- high fat, high carb -- the clock gets scrambled," Bass said. "The clock is sensitive to the time people eat, especially in fat tissue, and that sensitivity is thrown off by high-fat diets. We still don't understand why that is, but what we do know is that as animals become obese, they start to eat more when they should be asleep. This research shows why that matters."

Bass is also director of the Center for Diabetes and Metabolism and the chief of endocrinology in the department of medicine at Feinberg. Chelsea Hepler, a postdoctoral fellow in the Bass Lab, was the first author and did many of the biochemistry and genetics experiments that grounded the team's hypothesis. Rana Gupta, now at Duke University, was also a key collaborator.

Scrambling the internal clock

In the study, mice, who are nocturnal, were fed a high-fat diet either exclusively during their inactive (light) period or during their active (dark) period. Within a week, mice fed during light hours gained more weight compared to those fed in the dark. The team also set the temperature to 30 degrees, where mice expend the least energy, to mitigate the effects of temperature on their findings.

"We thought maybe there's a component of energy balance where mice are expending more energy eating at specific times," Hepler said. "That's why they can eat the same amount of food at different times of the day and be healthier when they eat during active periods versus when they should be sleeping."

The increase in energy expenditure led the team to look into metabolism of fat tissue to see if the same effect occurred within the endocrine organ. They found that it did, and mice with genetically enhanced thermogenesis -- or heat release through fat cells -- prevented weight gain and improved health.

Hepler also identified futile creatine cycling, in which creatine (a molecule that helps maintain energy) undergoes storage and release of chemical energy, within fat tissues, implying creatine may be the mechanism underlying heat release.

Intermittent fasting and gastric feeding tubes

The science is underpinned by research done by Bass and colleagues at Northwestern more than 20 years ago that found a relationship between the internal molecular clock and body weight, obesity and metabolism in animals.

The challenge for Bass's lab, which focuses on using genetic approaches to study physiology, has been figuring out what it all means, and finding the control mechanisms that produce the relationship. This study brings them a step closer.

The findings could inform chronic care, Bass said, especially in cases where patients have gastric feeding tubes. Patients are commonly fed at night while they sleep, when they're releasing the least amount of energy. Rates of diabetes and obesity tend to be high for these patients, and Bass thinks this could explain why. He also wonders how the research could impact Type II Diabetes treatment. Should meal times be considered when insulin is given, for example?

Hepler will continue to research creatine metabolism. "We need to figure out how, mechanistically, the circadian clock controls creatine metabolism so that we can figure out how to boost it," she said. "Clocks are doing a lot to metabolic health at the level of fat tissue, and we don't know how much yet."

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Discovery could dramatically narrow search for space creatures

An Earth-like planet orbiting an M dwarf -- the most common type of star in the universe -- appears to have no atmosphere at all. This discovery could cause a major shift in the search for life on other planets.

Because M-dwarfs are so ubiquitous, this discovery means a large number of planets orbiting these stars may also lack atmospheres and therefore are unlikely to harbor living things.

The work that led to the revelations about the no-atmosphere planet, named GJ 1252b, are detailed in the Astrophysical Journal Letters.

This planet orbits its star twice during the course of a single day on Earth. It is slightly larger than Earth, and it is much closer to its star than Earth is to the sun, making GJ 1252b intensely hot as well as inhospitable.

"The pressure from the star's radiation is immense, enough to blow a planet's atmosphere away," said Michelle Hill, UC Riverside astrophysicist and study co-author.

Earth also loses some of its atmosphere over time because of the sun, but volcanic emissions and other carbon cycling processes make the loss barely noticeable by helping replenish what is lost. However, in greater proximity to a star, a planet cannot keep replenishing the amount being lost.

In our solar system, this is the fate of Mercury. It does have an atmosphere, but one that is extremely thin, made up of atoms blasted off its surface by the sun. The extreme heat of the planet causes these atoms to escape into space.

To determine that GJ 1252b lacks an atmosphere, astronomers measured infrared radiation from the planet as its light was obscured during a secondary eclipse. This type of eclipse occurs when a planet passes behind a star and the planet's light, as well as light reflected from its star, is blocked.

The radiation revealed the planet's scorching daytime temperatures, estimated to reach 2,242 degrees Fahrenheit -- so hot that gold, silver, and copper would all melt on the planet. The heat, coupled with assumed low surface pressure, led the researchers to believe there's no atmosphere.

Even with a tremendous amount of carbon dioxide, which traps heat, the researchers concluded GJ 1252b would still not be able to hold on to an atmosphere. "The planet could have 700 times more carbon than Earth has, and it still wouldn't have an atmosphere. It would build up initially, but then taper off and erode away," said Stephen Kane, UCR astrophysicist and study co-author.

M dwarf stars tend to have more flares and activity than the sun, further reducing the likelihood that planets closely surrounding them could hold on to their atmospheres.

"It's possible this planet's condition could be a bad sign for planets even further away from this type of star," Hill said. "This is something we'll learn from the James Webb Space Telescope, which will be looking at planets like these."

Hill's work on this project was supported by a grant from the Future Investigators in NASA Earth and Space Science and Technology program.

The research was led by Ian Crossfield at the University of Kansas. It included scientists from UC Riverside as well as NASA's Jet Propulsion Laboratory, Caltech, University of Maryland, Carnegie Institution for Science, Max Planck Institute for Astronomy, McGill University, University of New Mexico, and the University of Montreal.

There are 5,000 stars in Earth's solar neighborhood, most of them M dwarfs. Even if planets orbiting them can be ruled out entirely, there are still roughly 1,000 stars similar to the sun that could be habitable.

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Unprecedented glimpse of merging galaxies

Using the James Webb Space Telescope to look back in time at the early universe, astronomers discovered a surprise: a cluster of galaxies merging together around a rare red quasar within a massive black hole. The findings by Johns Hopkins University and an international team offer an unprecedented opportunity to observe how billions of years ago galaxies coalesced into the modern universe.

"We think something dramatic is about to happen in these systems," said co-author Andrey Vayner, a Johns Hopkins postdoctoral fellow who studies the evolution of galaxies. "The galaxy is at this perfect moment in its lifetime, about to transform and look entirely different in a few billion years."

The work is in press in Astrophysical Journal Letters and available today on the arXiv paper repository.

The James Webb Space Telescope, launched last December by NASA, the European Space Agency, and the Canadian Space Agency, is the largest, most powerful telescope ever sent into space. Its initial general observations were revealed in July, but this quasar imagery is one of just 13 "early look" projects selected through a highly competitive global competition to decide where the telescope is pointed during its first months of operation.

In Baltimore, the Johns Hopkins team heard their chosen target would be observed within days of President Biden's unveiling of the Webb's debut pictures on July 11, so stayed close to their computers. That following summer Saturday, Vayner and graduate student Yuzo Ishikawa were repeatedly refreshing the Webb database when suddenly the data arrived, leading to a hastily assembled multinational team confab on Sunday to try to make sense of the jaw-droppingly detailed raw images.

Although earlier observations of this area by NASA/ESA Hubble Space Telescope and the Near-Infrared Integral Field Spectrometer instrument on the Gemini-North telescope pinpointed the quasar and hinted at the possibility of a galaxy in transition, no one suspected that with Webb's crisp imaging they'd see multiple galaxies, at least three, swirling the region.

"With previous images we thought we saw hints that the galaxy was possibly interacting with other galaxies on the path to merger because their shapes get distorted in the process and we thought we maybe saw that," said co-principal investigator Nadia L. Zakamska, a Johns Hopkins astrophysicist who helped conceive the project back in 2017 with then-Johns Hopkins postdoc Dominika Wylezalek, who's now the group leader at the University of Heidelberg. "But after we got the Webb data, I was like, 'I have no idea what we're even looking at here, what is all this stuff!' We spent several weeks just staring and staring at these images."

The Webb revealed at least three galaxies moving incredibly fast, suggesting a large amount of mass is present. The team believes this could be one of the densest known areas of galaxy formation in the early universe.

Because light takes time to travel to us, when we look at objects like this one in the very distant regions of the universe, we're seeing light that was emitted about 11.5 billion years ago, or from the earliest stages of the universe's evolution. Massive galaxy swarms like this one were likely common then, Zakamska said.

"It's super exciting to be one of the first people to see this really cool object," said Ishikawa, who contributed to the interpretation of the galaxy swarm.

Even Vayner, who'd dreamed of using Webb data since he first heard about the telescope as an undergraduate more than a decade ago, and thought he knew what to expect, was shocked to see his long-studied spot in the universe revealed with such clarity.

"It really will transform our understanding of this object," said Vayner, who was instrumental in adapting the raw Webb data for scientific analysis.

The blindingly bright quasar, fueled by what Zakamska calls a "monster" black hole at the center of the galactic swirl, is a rare "extremely red" quasar, about 11.5 billion years old and one of the most powerful ever seen from such distance. It's essentially a black hole in formation, Vayner said, eating the gas around it and growing in mass. The clouds of dust and gas between Earth and the glowing gas near the black hole make the quasar appear red.

The team is already working on follow-up observations into this unexpected galaxy cluster, hoping to better understand how dense, chaotic galaxy clusters form, and how it is affected by supermassive black hole at its heart.

"What you see here is only a small subset of what's in the data set," Zakamska said. "There's just too much going on here so we first highlighted what really is the biggest surprise. Every blob here is a baby galaxy merging into this mommy galaxy and the colors are different velocities and the whole thing is moving in an extremely complicated way. We can now start to untangle the motions."

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A 10,000-year-old infant burial provides insights into the use of baby carriers and family heirlooms in prehistory

If you've taken care of an infant, you know how important it is to find ways to multitask. And, when time is short and your to-do list is long, humans find ways to be resourceful -- something caregivers have apparently been doing for a very, very long time.

The authors of a new article published in the Journal of Archaeological Method and Theory argue that they have found evidence of the use of baby carriers 10,000 years ago at the Arma Veirana site in Liguria, Italy. The research, led by Arizona State University's Claudine Gravel-Miguel, PhD, also includes the University of Colorado Denver's Jamie Hodgkins, PhD, an Associate Professor of Anthropology, and a co-principal investigator on the excavation of Arma Veirana.

Because material used to make the first baby carriers does not preserve well in the archaeological record and because prehistoric baby burials are very uncommon, evidence for prehistoric baby carriers is extremely rare. The site -- which includes the oldest documented burial of a female infant in Europe, a 40- to 50-days-old baby, nicknamed Neve -- has both. Researchers used innovative analytical methods to extract hard-to-obtain information about perforated shell beads found at the site.

The study used a high-definition 3D photogrammetry model of the burial combined with microscopic observations and microCT scan analyses of the beads to document in detail how the burial took place and how the beads were likely used by Neve and her community in life and in death.

The results of this research show that the beads were likely sewn onto a piece of leather or cloth that was used to wrap Neve for her burial. This decoration contained more than 70 small, pierced shell beads and four big, pierced shell pendants, the likes of which have yet to be found elsewhere. Most of the beads bear heavy signs of use that could not have been produced during Neve's short life, demonstrating they were handed down to her as heirlooms.

"Given the effort that had been put into creating and reusing these ornaments over time, it is interesting that the community decided to part with these beads in the burial of such a young individual, said Gravel-Miguel. "Our research suggests that those beads and pendants likely adorned Neve's carrier, which was buried with her."

Relying on ethnographic observations of how baby carriers are adorned and used in some modern hunter-gatherer societies, this research suggests that Neve's community may have decorated her carrier with beads in order to protect her against evil. However, it is possible that her death signaled that those beads had failed, and it would have been better to bury the carrier rather than reuse it.

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Gel-like, radioactive tumor implant obliterates pancreatic cancer in mice

Biomedical engineers at Duke University have demonstrated the most effective treatment for pancreatic cancer ever recorded in mouse models. While most mouse trials consider simply halting growth a success, the new treatment completely eliminated tumors in 80% of mice across several model types, including those considered the most difficult to treat.

The approach combines traditional chemotherapy drugs with a new method for irradiating the tumor. Rather than delivering radiation from an external beam that travels through healthy tissue, the treatment implants radioactive iodine-131 directly into the tumor within a gel-like depot that protects healthy tissue and is absorbed by the body after the radiation fades away.

The results appear online October 19 in the journal Nature Biomedical Engineering.

"We did a deep dive through over 1100 treatments across preclinical models and never found results where the tumors shrank away and disappeared like ours did," said Jeff Schaal, who conducted the research during his PhD in the laboratory of Ashutosh Chilkoti, the Alan L. Kaganov Distinguished Professor of Biomedical Engineering at Duke. "When the rest of the literature is saying that what we're seeing doesn't happen, that's when we knew we had something extremely interesting."

Despite accounting for only 3.2% of all cancer cases, pancreatic cancer is the third leading cause of cancer-related death. It is a very difficult to treat because its tumors tend to develop aggressive genetic mutations that make it resistant to many drugs, and it is typically diagnosed very late, when it has already spread to other sites in the body.

The current leading treatment combines chemotherapy, which keeps cells in a stage of reproduction vulnerable to radiation for longer periods of time, with a beam of radiation targeted at the tumor. This approach, however, is ineffective unless a certain threshold of radiation reaches the tumor. And despite recent advances in shaping and targeting radiation beams, that threshold is very difficult to reach without risking severe side effects.

Another method researchers have tried involves implanting a radioactive sample encased in titanium directly within the tumor. But because titanium blocks all radiation other than gamma rays, which travel far outside the tumor, it can only remain within the body for a short period of time before damage to surrounding tissue begins to defeat the purpose.

"There's just no good way to treat pancreatic cancer right now," said Schaal, who is now director of research at Cereius, Inc., a Durham, North Carolina biotechnology startup working to commercialize a targeted radionuclide therapy through a different technology scheme.

To skirt these issues, Schaal decided to try a similar implantation method using a substance made of elastin-like polypeptides (ELPs), which are synthetic chains of amino acids bonded together to form a gel-like substance with tailored properties. Because ELPs are a focus of the Chilkoti lab, he was able to work with colleagues to design a delivery system well suited for the task.

The ELPs exist in a liquid state at room temperature but form a stable gel-like substance within the warmer human body. When injected into a tumor along with a radioactive element, the ELPs form a small depot encasing radioactive atoms. In this case, the researchers decided to use iodine-131, a radioactive isotope of iodine, because doctors have used it widely in medical treatments for decades and its biological effects are well understood.

The ELP depot encases the iodine-131 and prevents it from leaking out into the body. The iodine-131 emits beta radiation, which penetrates the biogel and deposits almost all its energy into the tumor without reaching the surrounding tissue. Over time, the ELP depot degrades into its constituent amino acids and is absorbed by the body -- but not before the iodine-131 has decayed into a harmless form of xenon.

"The beta radiation also improves the stability of the ELP biogel," Schaal said. "That helps the depot last longer and only break down after the radiation is spent."

In the new paper, Schaal and his collaborators in the Chilkoti laboratory tested the new treatment in concert with paclitaxel, a commonly used chemotherapy drug, to treat various mouse models of pancreatic cancer. They chose pancreatic cancer because of its infamy for being difficult to treat, hoping to show that their radioactive tumor implant creates synergistic effects with chemotherapy that relatively short-lived radiation beam therapy does not.

The researchers tested their approach on mice with cancers just under their skin created by several different mutations known to occur in pancreatic cancer. They also tested it on mice that had tumors within the pancreas, which is much more difficult to treat.

Overall, the tests saw a 100% response rate across all models, with the tumors being completely eliminated in three-quarters of the models about 80% of the time. The tests also revealed no immediately obvious side effects beyond what is caused by chemotherapy alone.

"We think the constant radiation allows the drugs to interact with its effects more strongly than external beam therapy allows," Schaal said. "That makes us think that this approach might actually work better than external beam therapy for many other cancers, too."

The approach, however, is still in its early preclinical stages and will not be available for human use anytime soon. The researchers say their next step is large animal trials, where they will need to show that the technique can be accurately done with the existing clinical tools and endoscopy techniques that doctors are already trained on. If successful, they look toward a Phase 1 clinical trial in humans.

"My lab has been working on developing new cancer treatments for close to 20 years, and this work is perhaps the most exciting we have done in terms of its potential impact, as late-stage pancreatic cancer is impossible to treat and is invariably fatal," Chilkoti said. "Pancreatic cancer patients deserve better treatment options than are currently available, and I am deeply committed to taking this all the way into the clinic."

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NASA's Webb takes star-filled portrait of pillars of creation

NASA's James Webb Space Telescope has captured a lush, highly detailed landscape -- the iconic Pillars of Creation -- where new stars are forming within dense clouds of gas and dust. The three-dimensional pillars look like majestic rock formations, but are far more permeable. These columns are made up of cool interstellar gas and dust that appear -- at times -- semi-transparent in near-infrared light.

Webb's new view of the Pillars of Creation, which were first made famous when imaged by NASA's Hubble Space Telescope in 1995, will help researchers revamp their models of star formation by identifying far more precise counts of newly formed stars, along with the quantities of gas and dust in the region. Over time, they will begin to build a clearer understanding of how stars form and burst out of these dusty clouds over millions of years.

Newly formed stars are the scene-stealers in this image from Webb's Near-Infrared Camera (NIRCam). These are the bright red orbs that typically have diffraction spikes and lie outside one of the dusty pillars. When knots with sufficient mass form within the pillars of gas and dust, they begin to collapse under their own gravity, slowly heat up, and eventually form new stars.

What about those wavy lines that look like lava at the edges of some pillars? These are ejections from stars that are still forming within the gas and dust. Young stars periodically shoot out supersonic jets that collide with clouds of material, like these thick pillars. This sometimes also results in bow shocks, which can form wavy patterns like a boat does as it moves through water. The crimson glow comes from the energetic hydrogen molecules that result from jets and shocks. This is evident in the second and third pillars from the top -- the NIRCam image is practically pulsing with their activity. These young stars are estimated to be only a few hundred thousand years old.

Although it may appear that near-infrared light has allowed Webb to "pierce through" the clouds to reveal great cosmic distances beyond the pillars, there are no galaxies in this view. Instead, a mix of translucent gas and dust known as the interstellar medium in the densest part of our Milky Way galaxy's disk blocks our view of the deeper universe.

This scene was first imaged by Hubble in 1995 and revisited in 2014, but many other observatories have also stared deeply at this region. Each advanced instrument offers researchers new details about this region, which is practically overflowing with stars.

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New way to make telescope mirrors could sharpen our view of the universe

Researchers have developed a new way to use femtosecond laser pulses to fabricate the high-precision ultrathin mirrors required for high-performance x-ray telescopes. The technique could help improve the space-based x-ray telescopes used to capture high-energy cosmic events involved in forming new stars and supermassive black holes.

"Detecting cosmic x-rays is a crucial piece of our exploration of the universe that unveils the high-energy events that permeate our universe but are not observable in other wavebands," said research team leader Heng Zuo, who performed the research at MIT Kavli Institute for Astrophysics and Space Research and is now at the University of New Mexico. "The technologies our group developed will help telescopes obtain sharp images of astronomical x-rays that can answer many intriguing science questions."

X-ray telescopes orbit above the Earth's atmosphere and contain thousands of thin mirrors that must each have a precisely curved shape and be carefully aligned with respect to all the other mirrors. In Optica, Optica Publishing Group's journal for high-impact research, the researchers describe how they used femtosecond laser micromachining to bend these ultrathin mirrors into a precise shape and correct errors that can arise in the fabrication process.

"It is difficult to make ultra-thin mirrors with an exact shape because the fabrication process tends to severely bend the thin material," said Zuo. "Also, telescope mirrors are usually coated to increase reflectivity, and these coatings typically deform the mirrors further. Our techniques can address both challenges."

Precision bending

New ways to fabricate ultra-precise and high-performance x-ray mirrors for telescopes are needed as new mission concepts continue to push the limits of x-ray imaging. For example, NASA's Lynx X-ray Surveyor concept will have the most powerful x-ray optic ever conceived and will require the manufacture of a large number of ultra-high-resolution mirrors.

To meet this need, Zuo's research group combined femtosecond laser micromachining with a previously developed technique called stress-based figure correction. Stress-based figure correction exploits the bendability of thin mirrors by applying a deformable film to the mirror substrate to adjust its stress states and induce controlled bending.

The technique involves selectively removing regions of a stressed film grown onto the back surface of a flat mirror. The researchers selected femtosecond lasers to accomplish this because the pulses produced by these lasers can create extremely precise holes, channels and marks with little collateral damage. Also, the high repetition rates of these lasers allow faster machining speeds and throughput compared to traditional methods. This could help speed up fabrication for the large numbers of ultra-thin mirrors required for next-generation x-ray telescopes.

Mapping stress

To carry out the new approach the researchers first had to determine exactly how laser micromachining changes the mirror's surface curvature and stress states. Then they measured the initial mirror shape and created a map of the stress correction necessary to create the desired shape. They also developed a multi-pass correction scheme that uses a feedback loop to repeatedly reduce errors until an acceptable mirror profile is achieved.

"Our experimental results showed that patterned removal of periodic holes leads to equibiaxial (bowl-shaped) stress states, while fine-pitched oriented removal of periodic troughs generates non-equibiaxial (potato-chip-shaped) stress components," said Zuo. "Combining these two features with proper rotation of the trough orientation we can create a variety of stress states that can, in principle, be used to correct for any type of error in the mirrors."

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Chimpanzees synchronize their steps just like humans

A new study by researchers at the University of St Andrews and the Central European University in Vienna has revealed that chimpanzees share a human tendency to unintentionally synchronise their steps when walking alongside one another.

Whilst it is already understood that chimpanzees can coordinate when working towards a goal, such as pulling a string to release food, much less is known about their propensity to coordinate spontaneously.

The study, led by Dr Manon Schweinfurth, Lecturer in the School of Psychology and Neuroscience at St Andrews and published in the journal Current Biology today (Thursday 20 October), recorded the walking behaviour of chimpanzees at the Chimfunshi Wildlife Orphanage Trust, a sanctuary in Zambia, under different conditions. The chimpanzees were observed when walking alone or when walking next to others.

Researchers observed that chimpanzees show unintentional synchronisation in their steps when walking next to one another, suggesting that human's strong tendency to coordinate simple actions is shared with our closest primate relative, and therefore might be an ancestral trait.

Dr Schweinfurth said: "Humans deliberately plan and coordinate actions with others during sport games, group dances, musical ensembles, or military actions. But it is also part of our daily life -- like carrying items together or getting a child dressed. Indeed, joint actions have been suggested to be crucial for our success as a species because much more can be achieved together than alone. In fact, we can't help it and coordinate actions even when it is not necessary to do so, such as falling into the same rhythm with someone walking next to us."

"In contrast, one of our closest living relatives, the chimpanzee, does not appear to show the same preference for rather complex joint actions. But little is known about simpler forms of joint action, such as a tendency to fall into inter-individual synchrony. Chimpanzees are particularly interesting here, as they are a good model for our last common ancestor with other African great apes."

"We investigated whether chimpanzees spontaneously coordinate their actions in a semi-natural environment when coordination was neither planned nor the goal of an interaction, i.e., when they were walking close to each other. For this, we recorded their undisturbed walking behaviour under different conditions. We found that chimpanzees show unintentional synchronisation in their steps when walking next to conspecifics."

The study involved both male and female chimpanzees of a variety of ages, some related and some unrelated. When the chimpanzees walked together, a step by one walker was followed by the same respective foot of the other walker in 79% of the cases within less than 0.5 seconds.

"This study provides evidence that chimpanzees temporally synchronise their body movements to the movements of their conspecifics. This interpersonal coordination of movements is often called entrainment and relies on perception-action links that become coupled. Understanding which mechanisms humans share with other species can help us understand the evolutionary origins of more sophisticated forms of joint action."

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The Black Death shaped the evolution of immunity genes, setting the course for how we respond to disease today

An international team of scientists who analyzed centuries-old DNA from victims and survivors of the Black Death pandemic has identified key genetic differences that determined who lived and who died, and how those aspects of our immune systems have continued to evolve since that time.

Researchers from McMaster University, the University of Chicago, the Pasteur Institute and other organizations analyzed and identified genes that protected some against the devastating bubonic plague pandemic that swept through Europe, Asia and Africa nearly 700 years ago. Their study has been published today in the journal Nature.

The same genes that once conferred protection against the Black Death are today associated with an increased susceptibility to autoimmune diseases such as Crohn's and rheumatoid arthritis, the researchers report.

The team focused on a 100-year window before, during and after the Black Death, which reached London in the mid-1300s. It remains the single greatest human mortality event in recorded history, killing upwards of 50 per cent of the people in what were then some of the most densely populated parts of the world.

More than 500 ancient DNA samples were extracted and screened from the remains of individuals who had died before the plague, died from it or survived the Black Death in London, including individuals buried in the East Smithfield plague pits used for mass burials in 1348-9. Additional samples were taken from remains buried in five other locations across Denmark.

Scientists searched for signs of genetic adaptation related to the plague, which is caused by the bacterium Yersinia pestis.

They identified four genes that were under selection, all of which are involved in the production of proteins that defend our systems from invading pathogens and found that versions of those genes, called alleles, either protected or rendered one susceptible to plague.

Individuals with two identical copies of a particular gene, known as ERAP2, survived the pandemic at a much higher rates than those with the opposing set of copies, because the 'good' copies allowed for more efficient neutralization of Y. pestis by immune cells.

"When a pandemic of this nature -- killing 30 to 50 per cent of the population -- occurs, there is bound to be selection for protective alleles in humans, which is to say people susceptible to the circulating pathogen will succumb. Even a slight advantage means the difference between surviving or passing. Of course, those survivors who are of breeding age will pass on their genes," explains evolutionary geneticist Hendrik Poinar, an author of the Nature paper, director of McMaster's Ancient DNA Centre, and a principal investigator with the Michael G. DeGroote Institute for Infectious Disease Research and McMaster's Global Nexus for Pandemics & Biological Threats.

Europeans living at the time of the Black Death were initially very vulnerable because they had had no recent exposure to Yersinia pestis. As waves of the pandemic occurred again and again over the following centuries, mortality rates decreased.

Researchers estimate that people with the ERAP2 protective allele (the good copy of the gene, or trait), were 40 to 50 per cent more likely to survive than those who did not.

"The selective advantage associated with the selected loci are among the strongest ever reported in humans showing how a single pathogen can have such a strong impact to the evolution of the immune system," says human geneticist Luis Barreiro, an author on the paper, and professor in Genetic Medicine at the University of Chicago.

The team reports that over time our immune systems have evolved to respond in different ways to pathogens, to the point that what had once been a protective gene against plague in the Middle Ages is today associated with increased susceptibility to autoimmune diseases. This is the balancing act upon which evolution plays with our genome.

"This highly original work has been possible only through a successful collaboration between very complementary teams working on ancient DNA, on human population genetics and the interaction between live virulent Yersinia pestis and immune cells," says Javier Pizarro-Cerda, head of the Yersinia Research Unit and director of the World Health Organization Collaborating Centre for Plague at the Pasteur Institute.

"Understanding the dynamics that have shaped the human immune system is key to understanding how past pandemics, like the plague, contribute to our susceptibility to disease in modern times," says Poinar.

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The most precise accounting yet of dark energy and dark matter

Astrophysicists have performed a powerful new analysis that places the most precise limits yet on the composition and evolution of the universe. With this analysis, dubbed Pantheon+, cosmologists find themselves at a crossroads.

Pantheon+ convincingly finds that the cosmos is composed of about two-thirds dark energy and one-third matter -- mostly in the form of dark matter -- and is expanding at an accelerating pace over the last several billion years. However, Pantheon+ also cements a major disagreement over the pace of that expansion that has yet to be solved.

By putting prevailing modern cosmological theories, known as the Standard Model of Cosmology, on even firmer evidentiary and statistical footing, Pantheon+ further closes the door on alternative frameworks accounting for dark energy and dark matter. Both are bedrocks of the Standard Model of Cosmology but have yet to be directly detected and rank among the model's biggest mysteries. Following through on the results of Pantheon+, researchers can now pursue more precise observational tests and hone explanations for the ostensible cosmos.

"With these Pantheon+ results, we are able to put the most precise constraints on the dynamics and history of the universe to date," says Dillon Brout, an Einstein Fellow at the Center for Astrophysics | Harvard & Smithsonian. "We've combed over the data and can now say with more confidence than ever before how the universe has evolved over the eons and that the current best theories for dark energy and dark matter hold strong."

Brout is the lead author of a series of papers describing the new Pantheon+ analysis, published jointly today in a special issue of The Astrophysical Journal.

Pantheon+ is based on the largest dataset of its kind, comprising more than 1,500 stellar explosions called Type Ia supernovae. These bright blasts occur when white dwarf stars -- remnants of stars like our Sun -- accumulate too much mass and undergo a runaway thermonuclear reaction. Because Type Ia supernovae outshine entire galaxies, the stellar detonations can be glimpsed at distances exceeding 10 billion light years, or back through about three-quarters of the universe's total age. Given that the supernovae blaze with nearly uniform intrinsic brightnesses, scientists can use the explosions' apparent brightness, which diminishes with distance, along with redshift measurements as markers of time and space. That information, in turn, reveals how fast the universe expands during different epochs, which is then used to test theories of the fundamental components of the universe.

The breakthrough discovery in 1998 of the universe's accelerating growth was thanks to a study of Type Ia supernovae in this manner. Scientists attribute the expansion to an invisible energy, therefore monikered dark energy, inherent to the fabric of the universe itself. Subsequent decades of work have continued to compile ever-larger datasets, revealing supernovae across an even wider range of space and time, and Pantheon+ has now brought them together into the most statistically robust analysis to date.

"In many ways, this latest Pantheon+ analysis is a culmination of more than two decades' worth of diligent efforts by observers and theorists worldwide in deciphering the essence of the cosmos," says Adam Riess, one of the winners of the 2011 Nobel Prize in Physics for the discovery of the accelerating expansion of the universe and the Bloomberg Distinguished Professor at Johns Hopkins University (JHU) and the Space Telescope Science Institute in Baltimore, Maryland. Riess is also an alum of Harvard University, holding a PhD in astrophysics.

Brout's own career in cosmology traces back to his undergraduate years at JHU, where he was taught and advised by Riess. There Brout worked with then-PhD-student and Riess-advisee Dan Scolnic, who is now an assistant professor of physics at Duke University and another co-author on the new series of papers.

Several years ago, Scolnic developed the original Pantheon analysis of approximately 1,000 supernovae.

Now, Brout and Scolnic and their new Pantheon+ team have added some 50 percent more supernovae data points in Pantheon+, coupled with improvements in analysis techniques and addressing potential sources of error, which ultimately has yielded twice the precision of the original Pantheon.

"This leap in both the dataset quality and in our understanding of the physics that underpin it would not have been possible without a stellar team of students and collaborators working diligently to improve every facet of the analysis," says Brout.

Taking the data as a whole, the new analysis holds that 66.2 percent of the universe manifests as dark energy, with the remaining 33.8 percent being a combination of dark matter and matter. To arrive at even more comprehensive understanding of the constituent components of the universe at different epochs, Brout and colleagues combined Pantheon+ with other strongly evidenced, independent and complementary measures of the large-scale structure of the universe and with measurements from the earliest light in the universe, the cosmic microwave background.

Another key Pantheon+ result relates to one of the paramount goals of modern cosmology: nailing down the current expansion rate of the universe, known as the Hubble constant. Pooling the Pantheon+ sample with data from the SH0ES (Supernova H0 for the Equation of State) collaboration, led by Riess, results in the most stringent local measurement of the current expansion rate of the universe.

Pantheon+ and SH0ES together find a Hubble constant of 73.4 kilometers per second per megaparsec with only 1.3% uncertainty. Stated another way, for every megaparsec, or 3.26 million light years, the analysis estimates that in the nearby universe, space itself is expanding at more than 160,000 miles per hour.

However, observations from an entirely different epoch of the universe's history predict a different story. Measurements of the universe's earliest light, the cosmic microwave background, when combined with the current Standard Model of Cosmology, consistently peg the Hubble constant at a rate that is significantly less than observations taken via Type Ia supernovae and other astrophysical markers. This sizable discrepancy between the two methodologies has been termed the Hubble tension.

The new Pantheon+ and SH0ES datasets heighten this Hubble tension. In fact, the tension has now passed the important 5-sigma threshold (about one-in-a-million odds of arising due to random chance) that physicists use to distinguish between possible statistical flukes and something that must accordingly be understood. Reaching this new statistical level highlights the challenge for both theorists and astrophysicists to try and explain the Hubble constant discrepancy.

"We thought it would be possible to find clues to a novel solution to these problems in our dataset, but instead we're finding that our data rules out many of these options and that the profound discrepancies remain as stubborn as ever," says Brout.

The Pantheon+ results could help point to where the solution to the Hubble tension lies. "Many recent theories have begun pointing to exotic new physics in the very early universe, however such unverified theories must withstand the scientific process and the Hubble tension continues to be a major challenge," says Brout.

Overall, Pantheon+ offers scientists a comprehensive lookback through much of cosmic history. The earliest, most distant supernovae in the dataset gleam forth from 10.7 billion light years away, meaning from when the universe was roughly a quarter of its current age. In that earlier era, dark matter and its associated gravity held the universe's expansion rate in check. Such state of affairs changed dramatically over the next several billion years as the influence of dark energy overwhelmed that of dark matter. Dark energy has since flung the contents of the cosmos ever-farther apart and at an ever-increasing rate.

"With this combined Pantheon+ dataset, we get a precise view of the universe from the time when it was dominated by dark matter to when the universe became dominated by dark energy," says Brout. "This dataset is a unique opportunity to see dark energy turn on and drive the evolution of the cosmos on the grandest scales up through present time."

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Neanderthals appear to have been carnivores

For the first time, zinc isotope ratios in tooth enamel have been analysed with the aim of identifying the diet of a Neanderthal. The Neanderthal to whom the tooth belonged was probably a carnivore. Other chemical tracers indicate that this individual did not consume the blood of their prey, but ate the bone marrow without consuming the bones.

A new study published on October 17th in the journal PNAS, led by a CNRS researcher, has for the first time used zinc isotope analysis to determine the position of Neanderthals in the food chain. Their findings suggest that they were in fact carnivores.

Were Neanderthals carnivores? Scientists have not yet settled the question. While some studies of the dental tartar of individuals from the Iberian Peninsula appear to show that they were major consumers of plants, other research carried out at sites outside Iberia seem to suggest that they consumed almost nothing but meat. Using new analytical techniques on a molar belonging to an individual of this species, researchers1 have shown that the Neanderthals at the Gabasa site in Spain appear to have been carnivores.

To determine an individual's position in the food chain, scientists have until now generally had to extract proteins and analyse the nitrogen isotopes present in the bone collagen. However, this method can often only be used in temperate environments, and only rarely on samples over 50,000 years old. When these conditions are not met, nitrogen isotope analysis is very complex, or even impossible. This was the case for the molar from the Gabasa site analysed in this study.

Given these constraints, Klevia Jaouen, a CNRS researcher, and her colleagues decided to analyse the zinc isotope ratios present in the tooth enamel, a mineral that is resistant to all forms of degradation. This is the first time this method has been used to attempt to identify a Neanderthal's diet. The lower the proportions of zinc isotopes in the bones, the more likely they are to belong to a carnivore. The analysis was also carried out on the bones of animals from the same time period and geographical area, including carnivores such as lynxes and wolves, and herbivores like rabbits and chamois. The results showed that the Neanderthal to whom this tooth from the Gabasa site belonged was probably a carnivore who did not consume the blood of their prey.

Broken bones found at the site, together with isotopic data, indicate that this individual also ate the bone marrow of their prey, without consuming the bones, while other chemical tracers show that they were weaned before the age of two. Analyses also show that this Neanderthal probably died in the same place they had lived in as a child.

Compared to previous techniques, this new zinc isotope analysis method makes it easier to distinguish between omnivores and carnivores. To confirm their conclusions, the scientists hope to repeat the experiment on individuals from other sites, especially from the Payre site in south-east France, where new research is under way.

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Meet the first Neanderthal family

For the first time, an international team led by researchers from the Max Planck Institute for Evolutionary Anthropology have managed to sequence multiple individuals from a remote Neandertal community in Siberia. Among these thirteen individuals, the researchers identified multiple related individuals -- among these a father and his teenage daughter. The researchers were also able to use the thirteen genomes to provide a glimpse into the social organization of a Neandertal community. They appear to have been a small group of close relatives, consisting of ten to twenty members, and communities were primarily connected through female migration.

The first Neanderthal draft genome was published in 2010. Since then, researchers from the Max Planck Institute for Evolutionary Anthropology have sequenced a further 18 genomes from 14 different archaeological sites throughout Eurasia. While these genomes have provided insights into the broader strokes of Neanderthal history, we still know little of individual Neanderthal communities.

To explore the social structure of Neanderthals, the researchers turned their attention to southern Siberia, a region that has previously been very fruitful for ancient DNA research -- including the discovery of Denisovan hominin remains at the famous Denisova Cave. From work done at that site, we know that Neanderthals and Denisovans were present in this region over hundreds of thousands of years, and that Neanderthals and Denisovans have interacted with each other -- as the finding of a child with a Denisovan father and a Neanderthal mother has shown.

First Neanderthal community

In their new study, the researchers focused on the Neanderthal remains in Chagyrskaya and Okladnikov Caves, which are within 100 kilometers of Denisova Cave. Neanderthals briefly occupied these sites around 54,000 years ago, and multiple potentially contemporaneous Neanderthal remains had been recovered from their deposits. The researchers successfully retrieved DNA from 17 Neanderthal remains -- the largest number of Neanderthal remains ever sequenced in a single study.

Chagyrskaya Cave has been excavated over the last 14 years by researchers from the Institute of Archaeology and Ethnography, Russian Academy of Sciences. Besides several hundred thousand stone tools and animal bones, they also recovered more than 80 bone and tooth fragments of Neanderthals, one of the largest assemblages of these fossil humans not only in the region but also in the world.

The Neanderthals at Chagyrskaya and Okladnikov hunted ibex, horses, bison and other animals that migrated through the river valleys that the caves overlook. They collected raw materials for their stone tools dozens of kilometers away, and the occurrence of the same raw material at both Chagyrskaya and Okladnikov Caves also supports the genetic data that the groups inhabiting these localities were closely linked.

Previous studies of a fossil toe from Denisova cave showed that Neanderthals inhabited the Altai mountains considerably earlier as well, around 120,000 years ago. Genetic data shows though, that the Neanderthals from Chagyrskaya and Okladnikov Caves are not descendants of these earlier groups, but are closer related to European Neanderthals. This is also supported by the archaeological material: the stone tools from Chagyrskaya Cave are most similar to the so-called Micoquian culture known from Germany and Eastern Europe.

The 17 remains came from 13 Neanderthal individuals -- 7 men and 6 women, of which 8 were adults and 5 were children and young adolescents. In their mitochondrial DNA, the researchers found several so-called heteroplasmies that were shared between individuals. Heteroplasmies are a special kind of genetic variant that only persists for a small number of generations.

The easternmost Neanderthals

Among these remains were those of a Neanderthal father and his teenage daughter. The researchers also found a pair of second degree relatives: a young boy and an adult female, perhaps a cousin, aunt or grandmother. The combination of heteroplasmies and related individuals strongly suggests that the Neanderthals in Chagyrskaya Cave must have lived -- and died -- at around the same time.

"The fact that they were living at the same time is very exciting. This means that they likely came from the same social community. So, for the first time, we can use genetics to study the social organization of a Neanderthal community," says Laurits Skov, who is first author on this study.

Another striking finding is the extremely low genetic diversity within this Neanderthal community, consistent with a group size of 10 to 20 individuals. This is much lower than those recorded for any ancient or present-day human community, and is more similar to the group sizes of endangered species at the verge of extinction.

However, Neanderthals didn't live in completely isolated communities. By comparing the genetic diversity on the Y-chromosome, which is inherited father-to-son, with the mitochondrial DNA diversity, which is inherited from mothers, the researchers could answer the question: Was it the men or the women who moved between communities? They found that the mitochondrial genetic diversity was much higher than the Y chromosome diversity, which suggests that these Neanderthal communities were primarily linked by female migration. Despite the proximity to Denisova Cave, these migrations do not appear to have involved Denisovans -- the researchers found no evidence of Denisovan gene flow in the Chagyrskaya Neanderthals in the last 20,000 years before these individuals lived.

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Five hours' sleep a night linked to higher risk of multiple diseases

Getting less than five hours of sleep in mid-to-late life could be linked to an increased risk of developing at least two chronic diseases, finds a new study led by UCL researchers.

The research, published in PLOS Medicine, analysed the impact of sleep duration on the health of more than 7,000 men and women at the ages of 50, 60 and 70, from the Whitehall II cohort study.

Researchers examined the relationship between how long each participant slept for, mortality and whether they had been diagnosed with two or more chronic diseases (multimorbidity) -- such as heart disease, cancer or diabetes -- over the course of 25 years.

People who reported getting five hours of sleep or less at age 50 were 20% more likely to have been diagnosed with a chronic disease and 40% more likely to be diagnosed with two or more chronic diseases over 25 years, compared to people who slept for up to seven hours.

Additionally, sleeping for five hours or less at the age of 50, 60, and 70 was linked to a 30% to 40% increased risk of multimorbidity when compared with those who slept for up to seven hours.

Researchers also found that sleep duration of five hours or less at age 50 was associated with 25% increased risk of mortality over the 25 years of follow-up -- which can mainly be explained by the fact that short sleep duration increases the risk of chronic disease(s) that in turn increase the risk of death.

Lead author, Dr Severine Sabia (UCL Institute of Epidemiology & Health, and Inserm, Université Paris Cité) said: "Multimorbidity is on the rise in high income countries and more than half of older adults now have at least two chronic diseases. This is proving to be a major challenge for public health, as multimorbidity is associated with high healthcare service use, hospitalisations and disability.

"As people get older, their sleep habits and sleep structure change. However, it is recommended to sleep for 7 to 8 hours a night -- as sleep durations above or below this have previously been associated with individual chronic diseases.

"Our findings show that short sleep duration is also associated with multimorbidity.

"To ensure a better night's sleep, it is important to promote good sleep hygiene, such as making sure the bedroom is quiet, dark and a comfortable temperature before sleeping. It's also advised to remove electronic devices and avoid large meals before bedtime. Physical activity and exposure to light during the day might also promote good sleep."

As part of the study, researchers also assessed whether sleeping for a long duration, of nine hours or more, affected health outcomes. There was no clear association between long sleep durations at age 50 and multimorbidity in healthy people.

However, if a participant had already been diagnosed with a chronic condition, then long sleep duration was associated with around a 35% increased risk of developing another illness. Researchers believe this could be due to underlying health conditions impacting sleep.

Jo Whitmore, senior cardiac nurse at the British Heart Foundation said: "Getting enough sleep allows your body to rest. There are a host of other ways that poor sleep could increase the risk of heart disease or stroke, including by increasing inflammation and increasing blood pressure.

"This research adds to a growing body of research that highlights the importance of getting a good night's sleep."

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Brain discovery holds key to boosting body's ability to fight Alzheimer's, MS

UVA Health researchers have discovered a molecule in the brain responsible for orchestrating the immune system's responses to Alzheimer's disease and multiple sclerosis (MS), potentially allowing doctors to supercharge the body's ability to fight those and other devastating neurological diseases.

The molecule the researchers identified, called a kinase, is crucial to both removing plaque buildup associated with Alzheimer's and preventing the debris buildup that causes MS, the researchers found. It does this, the researchers showed, by directing the activity of brain cleaners called microglia. These immune cells were once largely ignored by scientists but have, in recent years, proved vital players in brain health.

UVA's important new findings could one day let doctors augment the activity of microglia to treat or protect patients from Alzheimer's, MS and other neurodegenerative diseases, the researchers report.

"Unfortunately, medical doctors do not currently possess effective treatments to target the root causes of most neurodegenerative diseases, such as Alzheimer's, Parkinson's or ALS [amyotrophic lateral sclerosis, commonly called Lou Gehrig's disease]. In our studies, we have discovered a master controller of the cell type and processes that are required to protect the brain from these disorders," said senior researcher John Lukens, PhD, of the University of Virginia School of Medicine and its Center for Brain Immunology and Glia (BIG), as well as the Carter Immunology Center and the UVA Brain Institute. "Our work further shows that targeting this novel pathway provides a potent strategy to eliminate the toxic culprits that cause memory loss and impaired motor control in neurodegenerative disease."

Toxic Brain Buildup

Many neurodegenerative diseases, including Alzheimer's and MS, are thought to be caused by the brain's inability to cleanse itself of toxic buildup. Recent advances in neuroscience research have shed light on the importance of microglia in removing harmful debris from the brain, but UVA's new discovery offers practical insights into how this cleaning process occurs -- and the dire consequences when it doesn't.

Using a mouse model of Alzheimer's disease, the UVA researchers found that a lack of the molecule they identified, spleen tyrosine kinase, triggered plaque buildup in the brain and caused the mice to suffer memory loss -- like the symptoms seen in humans with Alzheimer's. Further, the neuroscientists were able to reduce the plaque buildup by activating this molecule and microglia in the brain, suggesting a potential treatment approach for human patients, though that would require significantly more research and testing.

"Our work has described a critical element of microglial function during Alzheimer's disease and MS," said researcher Hannah Ennerfelt, the first author of a new scientific paper outlining the findings. "Understanding the underlying biology of these cells during neurodegeneration may allow for scientists and doctors to develop increasingly informed and effective therapeutic interventions."

A lack of the molecule in a mouse model of MS, meanwhile, led to the buildup of damaged myelin, a protective coating on nerve cells. When myelin is damaged, the cells cannot transmit messages properly, causing MS symptoms such as mobility problems and muscle spasms. The UVA researchers conclude in a new scientific paper that the molecule they identified, abbreviated as SYK, is "critically involved" in the crucial removal of myelin debris. "If boosting SYK activity in microglia can decrease the amount of myelin debris in MS lesions, developing new drugs to target SYK could stop the progression of MS and help to reverse the damage," said Elizabeth L. Frost, PhD, a critical researcher on the project. "This is an especially promising option given that most of the currently available drugs for MS treatment dampen adaptive immunity. These immunosuppressive drugs lead to susceptibility to infection and higher risk of potentially fatal side effects like progressive multifocal leukoencephalopathy. Additionally, some forms of MS do not have a strong involvement of the immune system, and therefore there are currently very limited treatment options for those patients."

"Targeting SYK in microglia," she noted, "would circumvent multiple limitations of present-day therapeutics for MS."

Based on their promising results, the researchers report that targeting the molecule to stimulate the brain's immune activity could offer a way to treat not just Alzheimer's and MS but a "spectrum" of neurodegenerative diseases.

"These findings are especially exciting because they point to a treatment avenue in which we could alter the behavior of these native brain cells, microglia, to behave in a more neuroprotective way," said researcher Coco Holliday, a UVA undergraduate working in the Lukens lab. "It could potentially be applied to a variety of different neurological diseases that all share the problem of a buildup of toxic waste in the brain. It's been a very exciting project to be a part of."

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New analysis of obsidian blades reveals dynamic Neolithic social networks

An analysis of obsidian artifacts excavated during the 1960s at two prominent archaeological sites in southwestern Iran suggests that the networks Neolithic people formed in the region as they developed agriculture are larger and more complex than previously believed, according to a new study by Yale researchers.

The study, published Oct. 17 in the journal Proceedings of the National Academy of Sciences, is the first to apply state-of-the-art analytical tools to a collection of 2,100 obsidian artifacts housed at the Yale Peabody Museum. The artifacts were unearthed more than 50 years ago at Ali Kosh and Chagha Sefid, sites on Iran's Deh Luran Plain that yielded important archaeological discoveries from the Neolithic Era -- the period beginning about 12,000 years ago when people began farming, domesticating animals, and establishing permanent settlements.

Original analyses performed shortly after the artifacts were discovered had suggested people first acquired the obsidian -- volcanic glass -- from Nemrut Dağ, a now dormant volcano in Eastern Turkey, and then relied on an unknown second source for the material. This new elemental analysis showed the obsidian came from seven distinct sources, including Nemrut Dağ, in present-day Turkey and Armenia, which is as far as about 1,000 miles on foot from the excavation sites.

"It wasn't a simple pattern of people obtaining obsidian from one source and then shifting to the next," said Ellery Frahm, an archaeological scientist in the Department of Anthropology in Yale's Faculty of Arts and Sciences, and the study's lead author. "Rather, our analysis shows that they were acquiring obsidian from an increasingly diverse number of geological sources over time -- a trend that was impossible to detect with the technology and methods available 50 years ago."

The new analysis, combined with computer modeling, indicates that there were intensifying connections among Neolithic people, suggesting the presence of a greater number of settlements between the source volcanoes and the two sites where the artifacts were unearthed thousands of years later, Frahm said.

The artifacts were collected in the 1960s during multiple excavations of the two sites led by Frank Hole, the C.J. MacCurdy Professor Emeritus of Anthropology at Yale. The initial analyses were based largely on the artifacts' appearance, specifically their color when held up to sunlight. A subset of 28 artifacts were then subjected to an elemental analysis method common at the time that involved grinding them into powder.

Frahm and coauthor Christina M. Carolus, a doctoral student in the Department of Anthropology, are the first researchers to study the elemental composition of the obsidian artifacts since these early analyses. They used state-of-the-art portable X-ray fluorescence instruments, which allowed them to examine the entire collection without damaging the artifacts.

"Every aspect of the discoveries made at these sites had been revisited since the 1960s except the elemental composition and sourcing of the obsidian artifacts," Carolus said. "A lot more is known about the source volcanoes today than 50 years ago, and we know that sorting obsidian by color will miss a lot of nuances. Fortunately, we have instruments the size of cordless drills that, in a matter of seconds and without destroying material, give us a more accurate elemental signature than anything that was possible in the past."

Scientists widely believed that humanity's transition from the hunter-gatherer lifestyle to agriculture produced a period of rapid population growth due to the increased birth rates made possible by enhanced food supplies and permanent settlements. Finding evidence of this demographic shift often requires excavating locations that include burial sites, which can indicate a given settlement's population and provide a clearer picture of how agriculture allowed people to disperse across a landscape, Frahm said.

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Metabolism, not genes, may offer more insight into risk of some diseases

Our ancestry can be detected not only in our genes, but also in our metabolism, a new Yale-led study has found.

In an analysis of the metabolic profiles of healthy American babies, researchers found surprising differences among ethnic groups which may help make screening for inherited metabolic disorders, cystic fibrosis, or hypothyroidism much more accurate than traditional genetic disease screens.

"We don't want to miss a baby who is potentially sick, and we don't want to put families through the burdens and concerns that can stem from a false-positive test," said Curt Scharfe, associate professor of genetics at Yale School of Medicine and senior author of the study published in the journal Molecular Genetics and Metabolism.

For the study, Scharfe and colleagues analyzed data collected from more than 400,000 babies, representing 17 self-reported ethnic groups, who were part of California's newborn screening program. Specifically, they wanted to know if these ethnic differences could be detected in metabolites, molecules that provide energy by breaking down food or body tissue such as fat, found in the blood of the infants.

The question was not only of academic interest but of concern to pediatricians. For instance, it is known that babies of African heritage are more likely to have elevated blood biomarkers indicating cystic fibrosis than babies born to white parents, even though babies born to white parents are far more likely to eventually develop the disease. Researchers hope that using ancestry to interpret these differences in marker levels might offer more accurate ways to assess risks than traditional genetic tests.

People of African heritage are also known to have greater genetic diversity than those from ethnic groups because they are descendants of the world's oldest ancestral population. Modern humans emigrated from Africa to regions across the planet; other ethnic groups are descendants of these original migrants, and have enough variation in their DNA to make them genetically identifiable.

But metabolic lineages can tell a different story, the researchers found. For instance, while there is a clear delineation between genetic variants among African-Americans and Americans of European descent, researchers found that metabolically these two groups are more closely related. Conversely, while people of Japanese and Chinese descent, for instance, are closely related genetically, the researchers found larger differences in their metabolic profiles.

"This attests to the role of environment in forming our metabolism," Scharfe said. "Where people share the same culture and food, metabolic profiles are more similar. Where people are separated by circumstances, such as language or lifestyles, then differences in metabolism are greater than genetic variations."

Scharfe cautions that more work needs to be done before findings can be applied clinically. Researchers only analyzed 41 out of many hundreds of metabolites and relied on parents own reports of their ethnic heritage, which might not always correspond to reality.

"This is just a first snap shot, but understanding our metabolic ancestry has a promising future," Scharfe said.

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Isotope data strengthens suspicions of ivory stockpile theft

In January 2019, a seizure of 3.3 tons of ivory in Uganda turned up something surprising: markings on some of the tusks suggested that they may have been taken from a stockpile of ivory kept, it was thought, strictly under lock and key by the government of Burundi.

A new study from University of Utah distinguished professor Thure Cerling and colleagues, published in Proceedings of the National Academy of Sciences, uses carbon isotope science to show that the marked tusks were more than 30 years old and somehow had found their way from the guarded government stockpile into the hands of illegal ivory traders. The results suggest that governments that maintain ivory stockpiles may want to take a closer look at their inventory.

Ivory's isotope signatures

Cerling is a pioneer in the use of isotopes to answer questions about physical and biological processes. "Isotopes" of a given element refer to atoms of the element that vary in their number of neutrons, and thus vary oh-so-slightly in mass. A carbon-14 isotope has one more neutron than carbon-13, for example.

Some isotopes are stable and some are unstable. Unstable isotopes decay into other isotopes or elements through radioactive decay. Since the rate of decay is known for unstable isotopes, we can use the amounts present in a sample to determine ages. That's how carbon dating works -- it uses the rate of decay of unstable carbon-14 to determine the age of organic matter.

Around a decade ago, Cerling attended a presentation at the U by Sam Wasser of the University of Washington, who was studying the genetics of wildlife and using those tools to investigate the date and place of wildlife poaching. Cerling, recognizing that his expertise in isotope science might be able to add useful information, began an ongoing collaboration with Wasser.

In 2016, Cerling, Wasser and colleagues published a study that addressed a key question in the ivory trade: how old is the ivory seized by governments? Some traders have claimed their ivory is old, taken before 1976, and thus exempt from sales bans. And with the average size of ivory seizures more than 2.5 tons, researchers, governments and conservationists wonder how much of the ivory is recent and how much is coming from criminal stockpiles -- or is stolen from one of several ivory stockpiles held by the governments of some countries in Africa.

"Governments keep their stockpiles for multiple reasons," Wasser says. "They hope to sell the ivory for revenue, sometimes to support conservation efforts. However, they can only sell ivory from elephants that died of natural causes or were culled because they were problem animals. They can't sell seized ivory because they don't know it came from the country."

With the combination of Cerling's isotope data and Wasser's genetic data, the 2016 study found that more than 90% of seized ivory was from elephants that had been killed less than three years before. It was a sobering result, showing active and well-developed poaching and export networks. The study seemed to show that little ivory from government stockpiles had ended up on the black market.

Marked tusks

But the 2019 seizure of ivory in Uganda showed something concerning. Some of the tusks sported markings that looked suspiciously like the markings that CITES, the Convention on International Trade in Endangered Species of Wild Fauna and Flora, uses to inventory stockpiled ivory.

Due to the markings seen on some samples of the ivory," Cerling says, "it was thought that quite a few samples in this shipment could be related to material held in a government stockpile in Burundi. We were asked to date samples from this, and three other recent ivory seizures, to see if some samples could possibly be from older stockpiles."

To determine the ivory's age, the researchers collected small samples from the tusks and analyzed them for the amount of carbon-14 isotopes in each sample. They were looking specifically for the amount of "bomb carbon" in the tusks. Between 1945 and 1963, nuclear weapons testing doubled the amount of carbon-14 in the atmosphere, so anything living that's consumed carbon since then -- including you -- has a measurable carbon-14 signature. The amount of carbon-14 in a sample of ivory that hasn't yet radioactively decayed can tell scientists when the ivory stopped growing, or when the elephant died.

The method takes some calibration, using samples from organisms living in the same area. Some of the samples came from schoolchildren in Kenya, through a program called "Kids and Goats for Elephants." Because most families in rural Kenya keep goats the program, run by Cerling and Paula Kahumbu of WildlifeDirect engages children in collecting hair samples from goats for isotopic analysis. The isotope data is useful for many applications, including fighting elephant poaching and, in this case, calibrating the bomb carbon decay rate for more accurate dating of ivory.

A consequential result

The researchers analyzed ivory from four seizures in Angola, Hong Kong, Singapore and Uganda. Genetic data ensured that they weren't sampling two tusks from the same individual. The results of analysis from the Angola, Hong Kong and Singapore seizures were as expected -- the samples were mostly around three years after the death of the elephant, with no tusks having been taken more than 10 years previous.

But the Uganda seizure, with the inventory markings on the tusks, showed something very different. Nine of the 11 tusks tested had been taken more than 30 years before, with the dates of death ranging between 1985 and 1988. Those dates are consistent with the age of ivory in the stockpile of the government of Burundi, which was inventoried and stored in sealed containers in 1989.

"My suspicions were affirmed," Wasser says. "The bigger surprise was how near to 1989 the elephants were killed." At the time Burundi assembled its stockpile, a condition of joining CITES, which assists governments in managing ivory reserves, was that the ivory to be stockpiled was old. The results suggest that that wasn't the case, Wasser says, which would have violated conditions for Burundi to join CITES.

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Revealing the mysteries of the universe under the skin of an atomic nucleus

Massive neutron stars colliding in space are thought to be able to create precious metals such as gold and platinum. The properties of these stars are still an enigma, but the answer may lie beneath the skin of one of the smallest building blocks on Earth -- an atomic nucleus of lead. Getting the nucleus of the atom to reveal the secrets of the strong force that governs the interior of neutron stars has proven difficult. Now a new computer model from Chalmers University of Technology, Sweden, can provide answers.

In a recently published article in the scientific journal Nature Physics, Chalmers researchers present a breakthrough in the calculation of the atomic nucleus of the heavy and stable element lead.

The strong force plays the main role

Despite the huge size difference between a microscopic atomic nucleus and a neutron star several kilometers in size, it is largely the same physics that governs their properties. The common denominator is the strong force that holds the particles -- the protons and neutrons -- together in an atomic nucleus. The same force also prevents a neutron star from collapsing. The strong force is fundamental in the universe, but it is difficult to include in computational models, not least when it comes to heavy neutron-rich atomic nuclei such as lead. Therefore, the researchers have wrestled with many unanswered questions in their challenging calculations.

A reliable way to make calculations

"To understand how the strong force works in neutron-rich matter, we need meaningful comparisons between theory and experiment. In addition to the observations made in laboratories and with telescopes, reliable theoretical simulations are therefore also needed. Our breakthrough means that we have been able to carry out such calculations for the heaviest stable element -- lead," says Andreas Ekström, Associate Professor at the Department of Physics at Chalmers and one of the main authors of the article.

The new computer model from Chalmers, developed together with colleagues in North America and England, now shows the way forward. It enables high precision predictions of properties for the isotope* lead-208 and its so-called 'neutron skin'.

The thickness of the skin matters

It is the 126 neutrons in the atomic nucleus that form an outer envelope, which can be described as a skin. How thick the skin is, is linked to the properties of the strong force. By predicting the thickness of the neutron skin, knowledge can increase about how the strong force works -- both in atomic nuclei and in neutron stars.

"We predict that the neutron skin is surprisingly thin, which can provide new insights into the force between the neutrons. A groundbreaking aspect of our model is that it not only provides predictions, but also has the ability to assess theoretical margins of error. This is crucial for being able to make scientific progress," says research leader Christian Forssén, Professor at the Department of Physics at Chalmers.

Model used for the spread of the coronavirus

To develop the new computational model, the researchers have combined theories with existing data from experimental studies. The complex calculations have then been combined with a statistical method previously used to simulate the possible spread of the coronavirus.

With the new model for lead, it is now possible to evaluate different assumptions about the strong force. The model also makes it possible to make predictions for other atomic nuclei, from the lightest to the heaviest.

The breakthrough could lead to much more precise models of, for example, neutron stars and increased knowledge of how these are formed.

"The goal for us is to gain a greater understanding of how the strong force behaves in both neutron stars and atomic nuclei. It takes the research one step closer to understanding how, for example, gold and other elements could be created in neutron stars- and at the end of the day it is about understanding the universe," says Christian Forssén.

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Properties of 'baby talk' similar across many languages

A study by the University of York and Aarhus University has revealed that baby talk displays similar properties across 36 languages.

'Baby talk' or infant directed speech (IDS) refers to the way caregivers talk to young infants, and generally includes a high-pitched, slow-paced, animated speech.

This spontaneous, automatic and intuitive way of speaking has been studied for decades to understand why human beings communicate in this way with infants and what it might suggest about child development.

The York and Aarhus team addressed the question of whether IDS had a universal quality -- does it, for example, have the same properties in English as it does in other languages? They also addressed whether this changes as the child's grasp on language and speech increases.

Using a meta-analytic method, they examined all previous studies that investigated sound properties of IDS and asked what these revealed about its function in child language development. They found that certain features of IDS, such as pitch, melody, and articulation rates have the same properties across most of the world's languages.

How much caregivers exaggerate the differences between vowel sounds, however, was markedly different across the languages.

Christopher Cox, who led the study and is a joint PhD student at the University of York's Department of Language & Linguistic Science and Aarhus University's Department of Linguistics & Cognitive Science, said: "We use a higher pitch, more melodious phrases, and a slower articulation rate when talking to infants compared to how we talk to adults, and this appears to be the same across most languages.

"In the English language, caregivers typically exaggerate the difference in vowel sounds in infant directed speech, but this seemed to vary across other languages. More work is needed to understand why that is, but we might expect, for example, that speakers of languages with lots of vowels would be more inclined to clarify this speech signal for their children."

Languages that have been studied so far have focused on English and European languages, but to understand more about the instinctive use of IDS and how it helps in child development, the researchers argue more work is needed in understudied, non-Western languages.

The study also showed that IDS changes over time, as infants get a better grasp on language and speech. Most features of IDS gradually become more similar to adult speech style -- such as pitch and speed of delivery -- but other features, such as the high pitch melodic sounds and exaggerated vowels continue into early life.

Associate Professor Riccardo Fusaroli, co-author of the study from Aarhus University, said: "These results really highlight the interactive nature of this speech style, with caregivers providing dynamic and tailored feedback to their children's vocalisations and reacting to infants' changing developmental needs."

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Back to the future of photosynthesis

The central biocatalyst in photosynthesis, Rubisco, is the most abundant enzyme on earth. By reconstructing billion-year-old enzymes, a team of Max Planck researchers has deciphered one of the key adaptations of early photosynthesis. Their results not only provide insights into the evolution of modern photosynthesis but also offer new impulses for improving it.

Present day life fully depends on photosynthetic organisms like plants and algae that capture and convert CO2. At the heart of these processes lies an enzyme called Rubisco that captures more than 400 billion tons CO2 annually. Organisms alive today make staggering amounts of it: the mass of Rubisco on our planet outweighs that of all humans. In order to assume such a dominant role in the global carbon cycle, Rubisco had to adapt constantly to changing environmental conditions.

Using a combination of computational and synthetic approaches, a team from the Max Planck Institute for Terrestrial Microbiology in Marburg, Germany, in collaboration with the University of Singapore has now successfully resurrected and studied billion-year-old enzymes in the lab. In this process, which they describe as "molecular paleontology," the researchers found that instead of direct mutations in the active center, an entirely new component prepared photosynthesis to adapt to rising oxygen levels.

Rubisco's early confusion

Rubisco is ancient: it emerged approximately four billion years ago in primordial metabolism prior to the presence of oxygen on earth. However, with the invention of oxygen-producing photosynthesis and rise of oxygen in the atmosphere, the enzyme started catalyzing an undesired reaction, in which it mistakes O2 for CO2 and produces metabolites that are toxic to the cell. This confused substrate scope still scars Rubiscos to date and limits photosynthetic efficiency. Even though Rubiscos that evolved in oxygen-containing environments became more specific for CO2 over time, none of them could get completely rid of the oxygen capturing reaction.

The molecular determinants of increased CO2 specificity in Rubisco remain largely unknown. However, they are of great interest to researchers aiming to improve photosynthesis. Interestingly, those Rubiscos that show increased CO2 specificity recruited a novel protein component of unknown function. This component was suspected to be involved in increasing CO2 specificity, however, the true reason for its emergence remained difficult to determine because it already evolved billions of years ago.

Studying evolution by resurrecting ancient proteins in the lab

To understand this key event in the evolution of more specific Rubiscos, collaborators at the Max Planck Institute for Terrestrial Microbiology in Marburg and Nanyang Technological University in Singapore used a statistical algorithm to recreate forms of Rubiscos that existed billions of years ago, before oxygen levels began to rise. The team led by Max Planck researchers Tobias Erb and Georg Hochberg resurrected these ancient proteins in the lab to study their properties. In particular, the scientists wondered whether Rubisco's new component had anything to do with the evolution of higher specificity.

The answer was surprising, as doctoral researcher Luca Schulz explains: "We expected the new component to somehow directly exclude oxygen from Rubisco catalytic center. That is not what happened. Instead, this new subunit seems to act as a modulator for evolution: recruitment of the subunit changed the effect that subsequent mutations had on Rubisco's catalytic subunit. Previously inconsequential mutations suddenly had a huge effect on specificity when this new component was present. It seems that having this new subunit completely changed Rubisco's evolutionary potential."

An enzyme's addiction to its new subunit

This function as an "evolutionary modulator" also explains another mysterious aspect of the new protein component: Rubiscos that incorporated it are completely dependent on it, even though other forms of Rubisco can function perfectly well without. The same modulating effect explains why: When bound to this small protein component, Rubisco become tolerant to mutations that would otherwise be catastrophically detrimental. With the accumulation of such mutations, Rubisco effectively became addicted to its new subunit.

Altogether, the findings finally explain the reason why Rubisco kept this new protein component around ever since it encountered it. Max Planck Research Group Leader Georg Hochberg explains: "The fact that this connection was not understood until now highlights the importance of evolutionary analysis for understanding the biochemistry that drives life around us. The history of biomolecules like Rubisco can teach us so much about why they are the way they are today. And there are still so many biochemical phenomena whose evolutionary history we really have no idea about. So it's a very exciting time to be an evolutionary biochemist: almost the entire molecular history of the cell is still waiting to be discovered."

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Impact of coral chemical compounds on reef composition and health

Stumbling upon a new source of underwater caffeine was just an added bonus of a new study examining the impact of chemical compounds that corals release into the seawater.

The study found that the organic chemical compounds produced through metabolism -- known as metabolites or exudates -- vary significantly by coral species and that the compounds impact the abundances and compositions of reef microorganisms differently.

This differential release of metabolites from benthic reef organisms is particularly significant in the Caribbean where coral dominance is shifting from hard stony corals to soft octocorals in response to human-caused stressors such as eutrophication, overfishing, and global climate change.

The study "demonstrates the importance of benthic exudates for structuring microbial communities on oligotrophic reefs by focusing on the exudates released from abundant stony corals, octocorals, and an invasive alga," according to the paper led by authors from the Woods Hole Oceanographic Institution (WHOI), "Benthic exometabolites and their ecological significance on threatened Caribbean coral reefs," published in ISME Communications.

"We wanted to know what are the molecules that coral organisms release into the environment, and how do those molecules impact the reef microbes in the seawater surrounding the corals," said lead author Laura Weber, a former postdoc and current information systems associate in WHOI's Marine Chemistry & Geochemistry Department.

"As the species composition of these reefs shifts, it is likely changing the chemicals that are released on the reef that then will have impacts on the microbial community," Weber said. "We need to pay more attention to how changes in reef structure and species composition might influence the microbes that live on the reef, leading to more feedbacks in terms of reef health." She said that understanding microbes on reefs, how they are functioning, and how they might be contributing to the health of corals and of reefs themselves is "pretty much an untapped area to explore."

Here's the caffeine connection.

For the study, researchers collected exudates from six species of Caribbean benthic organisms in a lab setting, using organisms obtained from within the Virgin Islands National Park, including stony corals, octocorals, and an invasive encrusting alga called Ramicrusta textilis. The researchers surprisingly found that R. textilis released caffeine in high quantities.

Their results further "demonstrate that exudates from benthic organisms contribute to the complex pool of extracellular metabolites in reef seawater and that exudate composition varies significantly by species," according to the study

As to why R. textilis produces caffeine, the study notes that caffeine production has not been widely investigated for marine organisms, but that it is a common metabolite produced by land plants generally to deter herbivores and pathogenic microbes. These characteristics "could contribute to the ability of R. textilis to invade and flourish on Caribbean reefs," according to the report. "Given the growing prevalence of Ramicrusta on diverse Caribbean reefs, follow-up research examining the ecological significance of its metabolites on microbes and other reef organisms is needed."

This study "is an important step forward in identifying chemical signals that can help scientists assess reef health," said Elizabeth Kujawinski, co-author of the paper. "Similar to human health diagnostics, the chemical signals within a reef ecosystem are intimately linked to the functions of the symbiotic relationships within reefs." Kujawinski is a senior scientist in WHOI's Marine Chemistry & Geochemistry Department and director of the Center for Chemical Currencies of a Microbial Planet (C-CoMP), a National Science Foundation Science and Technology Center that is based at WHOI.

Co-author Amy Apprill, associate scientist in WHOI's Marine Chemistry & Geochemistry Department, said an important implication of the research is that a diverse benthic community helps to contribute to a more varied metabolite pool and likely supports a more diverse microbial community.

"We are trying to build kind of a library of what microbes and metabolites are present on reefs. My dream is to be able to go out to a reef, take a bucket of reef water, screen it for microbes and metabolites, and be able to tell something about the health of that ecosystem," Apprill said. "This is so important to do because the current methods to monitor reefs are highly visual-based, and it can take months or years to determine if coral is sick or growing. Metabolites and microbes have the potential to be really sensitive sensors for reef health."

This research was conducted with support from the National Oceanic and Atmospheric Administration and the National Science Foundation.

Key Takeaways

Chemical compounds produced through metabolism and then released -- known as metabolites or exudates -- vary significantly by coral species and impact the abundances and compositions of reef microorganisms differently.

The differential release of metabolites from benthic reef organisms is particularly significant in the Caribbean where coral dominance is shifting from hard stony corals to soft octocorals in response to human-caused stressors such as eutrophication, overfishing, and global climate change.

"As the species composition of these reefs shifts, it is likely changing the chemicals that are released on the reef that then will have impacts on the microbial community. We need to pay more attention to how changes in reef structure and species composition might influence the microbes that live on the reef, leading to more feedbacks in terms of reef health."

Stumbling on a new source of underwater caffeine was just an added bonus of a new study examining the impact of chemical compounds that corals release into the seawater.

This study "is an important step forward in identifying chemical signals that can help scientists assess reef health. Similar to human health diagnostics, the chemical signals within a reef ecosystem are intimately linked to the functions of the symbiotic relationships within reefs."

Read more at Science Daily