Culture

Joanna Clark has been interested in geology ever since she was a child. Today, the University of Houston doctoral student is turning that curiosity into a career and getting noticed by NASA, which awarded her a $285,000 grant to develop a technique that could one day be used to better understand past climate conditions on Mars.

"We hope to have samples from Mars one day and when we do, we need to be ready to evaluate them. This could help give us a better understanding of how the planet has changed over millions of years," said Clark, who is studying the geochemistry of Mars.

For now, Clark's research will focus on creating silica minerals in the laboratory to discover how they form in subzero temperatures, such as those on Mars. Silica minerals, including quartz, are commonly found in Earth surface sediment, but silica was also detected in rocks and sediment on Mars by NASA's Curiosity Rover.

The initial experiments have begun. "I am working on how to get the silica out of solution as a solid with all the right chemistry. Once I am able to do that, I will take the solid and analyze it for oxygen isotopes," explained Clark, who has done previous studies on cryogenic opal-A, which is silica that forms in brine veins between growing water ice crystals.

Tom Lapen, Clark's research advisor and chair of the Department of Earth and Atmospheric Sciences in the UH College of Natural Sciences and Mathematics, said silica might be able to preserve the conditions under which it actually precipitated, or became a solid, from a liquid. In other words, silica found on Mars is a potential source of past climate information.

Lapen and Clark are working with Zach Sharp, who runs the Center for Stable Isotopes at the University of New Mexico. Sharp developed the analytical technique and Clark will build upon it by investigating silica samples formed below zero degrees Celsius.

"Joanna is competing with some of the best scientists in the country. Most of them are professors and researchers who have been doing this a long time," said Lapen, referring to Clark's NASA grant. "It indicates that the community views this project on really high merits and if successfully accomplished, it could have a big impact."

Other project collaborators are Henry Chafetz, UH professor of geology and Elizabeth Rampe, an exploration mission scientist in the Astromaterials Research and Exploration Science Division at the Johnson Space Center.

DURHAM, N.C. -- A high-fat meal can silence communication between the intestine and the rest of the body, according to a new Duke University study in zebrafish.

While using the fish to examine cells that normally tell the brain and the rest of the body what's going on inside the gut after a meal, a team of Duke researchers discovered that a high-fat meal completely shuts down that communication for a few hours.

The cells they were looking at are the enteroendocrine cells, which occur sparsely throughout the lining of the gut, but play a key role in signaling the body about the all-important alimentary canal. In addition to releasing hormones, the cells also have a recently-discovered direct connection to the nervous system and the brain.

These cells produce at least 15 different hormones to send signals to the rest of the body about gut movement, feelings of fullness, digestion, nutrient absorption, insulin sensitivity and energy storage.

"But they fall asleep on the job for a few hours after a high-fat meal, and we don't yet know if that's good or bad," said John Rawls, an associate professor of molecular genetics and microbiology in the Duke School of Medicine.

Since enteroendocrine cells are key players in digestion, the feeling of being full and subsequent feeding behavior, this silencing may be a mechanism that somehow causes people eating a high-fat diet to eat even more.

"This is a previously unappreciated part of the postprandial (after-meal) cycle," Rawls said. "If this happens every time we eat an unhealthy, high-fat meal, it might cause a change in insulin signaling, which could in turn contribute to the development of insulin resistance and Type 2 diabetes."

To understand the silencing better, the researchers tried to break the process down step by step in zebrafish.

After they first sense a meal, the enteroendocrine cells trigger a calcium burst within seconds, initiating the signaling process. But after that initial signal there's a delayed effect later in the after-meal period. It's during this later response that the silencing occurs, said Rawls, who also directs Duke's Microbiome Center.

The silenced cells change shape and experience stress in their endoplasmic reticulum, a structure that assembles new proteins. It seems that these enteroendocrine cells, which are specialized to synthesize and secrete proteins like hormones and neurotransmitters, become overstimulated and exhausted for a while.

The team tried the high-fat diet on a line of germ-free zebrafish raised in the absence of any microbes, and found they didn't experience the same silencing effect. So they began looking for gut microbes that might be involved in the process.

After screening through all the kinds of bacteria found in the gut, they saw that the silencing appeared to be the work of a single type of gut bacteria, called Acinetobacter. These bugs are normally less than 0.1 percent of the total gut microbiome, but they increased 100-fold after a high-fat meal and were the only bacteria able to induce the silencing effect.

"Next we want to understand how Acinetobacter evokes this interesting response," said Lihua Ye, a postdoctoral fellow and lead author on this paper. "We also suspect other bacteria might also have this capability."

Rawls said they aren't sure why silencing occurs, nor whether it has any positive effect on the fish. It might be a way to prevent excessive signaling about the fat, but by being silenced completely like this, the cells won't be communicating anything else either.

"We don't understand yet what the long-term impact of enteroendocrine silencing would be on metabolic health," Rawls said. "This may be a maladaptive response to high-fat feeding that impairs the normal regulatory functions of these cells, leading to metabolic disorders like insulin resistance. But it's also possible that the silencing is a beneficial adaptation to protect the animal from over-stimulation of the gut cells."

Rochester Institute of Technology and the Instituto Argentino de Radioastronomía (IAR) have collaborated to make the first pulsar observations from South America.

A new paper published in Astronomy and Astrophysics outlines how the team upgraded two radio telescopes in Argentina that lay dormant for 15 years in order to study pulsars. Pulsars are rapidly rotating neutron stars with intense magnetic fields that emit notably in radio wavelengths. The pulses they emit carry information about the structure of neutron stars.

Since getting the radio telescopes operational once again, the team has observed phenomena including a millisecond pulsar (J0437-4515), a magnetar (XTE J1810-197) and a glitch in the period of the Vela pulsar (J0835-4510). A glitch is a sudden change in the rotational period of the neutron star, due to a sort of quake leading to changes in the pulsar period. This is particularly noticeable in young pulsars, like Vela.

"We have opened up the possibility to directly observe and study neutron stars in the deep southern sky from our lab in the northern hemisphere," said Carlos Lousto, professor in RIT's School of Mathematical Sciences and a member of the Center for Computational Relativity and Gravitation (CCRG). "Those stars are not directly accessible from radio telescopes in the north because the Earth lies in between our sight line. We have also implemented a visitor program to and from Argentina that increases the RIT interactions with Hispanic scientists and culture."

The two radio telescope antennae, each 30 meters in diameter, are located at the IAR observatory in the Pereyra Iraola provincial park near the city of La Plata, Argentina. Observations are performed remotely at RIT from the Pulsar Monitoring in Argentina Data Enabling Network (PuMA-DEN) lab by members of RIT's CCRG.

Three years of work culminated when Professor Manuela Campanelli, director of RIT's CCRG, and Professor Gustavo Romero, director of IAR, signed an agreement to exchange visitors, scientific projects and data. The early findings have the scientists involved encouraged about pursuing larger goals such as coordinated multi-wavelength observations with other observatories and studying transient phenomena such as magnetars, glitches and fast radio burst sources.

Researchers from the University of Copenhagen have succeeded in extracting a complete human genome from a thousands-of-years old "chewing gum". According to the researchers, it is a new untapped source of ancient DNA.

During excavations on Lolland, archaeologists have found a 5,700-year-old type of "chewing gum" made from birch pitch. In a new study, researchers from the University of Copenhagen succeeded in extracting a complete ancient human genome from the pitch.

It is the first time that an entire ancient human genome has been extracted from anything other than human bones. The new research results have been published in the scientific journal Nature Communications.

'It is amazing to have gotten a complete ancient human genome from anything other than bone,'' says Associate Professor Hannes Schroeder from the Globe Institute, University of Copenhagen, who led the research.

'What is more, we also retrieved DNA from oral microbes and several important human pathogens, which makes this a very valuable source of ancient DNA, especially for time periods where we have no human remains,' Hannes Schroeder adds.

Based on the ancient human genome, the researchers could tell that the birch pitch was chewed by a female. She was genetically more closely related to hunter-gatherers from the mainland Europe than to those who lived in central Scandinavia at the time. They also found that she probably had dark skin, dark hair and blue eyes.

Sealed in mud

The birch pitch was found during archaeological excavations at Syltholm, east of Rødbyhavn in southern Denmark. The excavations are being carried out by the Museum Lolland-Falster in connection with the construction of the Fehmarn tunnel.

'Syltholm is completely unique. Almost everything is sealed in mud, which means that the preservation of organic remains is absolutely phenomenal,' says Theis Jensen, Postdoc at the Globe Institute, who worked on the study for his PhD and also participated in the excavations at Syltholm.

'It is the biggest Stone Age site in Denmark and the archaeological finds suggest that the people who occupied the site were heavily exploiting wild resources well into the Neolithic, which is the period when farming and domesticated animals were first introduced into southern Scandinavia,' Theis Jensen adds.

This is reflected in the DNA results, as the researchers also identified traces of plant and animal DNA in the pitch - specifically hazelnuts and duck - which may have been part of the individual's diet.

Bacterial evolution

In addition, the researchers succeeded in extracting DNA from several oral microbiota from the pitch, including many commensal species and opportunistic pathogens.

'The preservation is incredibly good, and we managed to extract many different bacterial species that are characteristic of an oral microbiome. Our ancestors lived in a different environment and had a different lifestyle and diet, and it is therefore interesting to find out how this is reflected in their microbiome,' says Hannes Schroeder.

The researchers also found DNA that could be assigned to Epstein-Barr Virus, which is known to cause infectious mononucleosis or glandular fever. According to Hannes Schroeder, ancient "chewing gums" bear great potential in researching the composition of our ancestral microbiome and the evolution of important human pathogens.

'It can help us understand how pathogens have evolved and spread over time, and what makes them particularly virulent in a given environment. At the same time, it may help predict how a pathogen will behave in the future, and how it might be contained or eradicated,' says Hannes Schroeder.

Iowa State researchers have found for the first time that less muscle and more body fat may affect how flexible our thinking gets as we become older, and changes in parts of the immune system could be responsible.

These findings could lead to new treatments that help maintain mental flexibility in aging adults with obesity, sedentary lifestyles, or muscle loss that naturally happens with aging.

The study, led by Auriel Willette, assistant professor of food science and human nutrition, and Brandon Klinedinst, a PhD student in neuroscience, looked at data from more than 4,000 middle-aged to older UK Biobank participants, both men and women. The researchers examined direct measurements of lean muscle mass, abdominal fat, and subcutaneous fat, and how they were related to changes in fluid intelligence over six years.

Willette and Klinedinst discovered people mostly in their 40s and 50s who had higher amounts of fat in their mid-section had worse fluid intelligence as they got older. Greater muscle mass, by contrast, appeared to be a protective factor. These relationships stayed the same even after taking into account chronological age, level of education, and socioeconomic status.

"Chronological age doesn't seem to be a factor in fluid intelligence decreasing over time," Willette said. "It appears to be biological age, which here is the amount of fat and muscle."

Generally, people begin to gain fat and lose lean muscle once they hit middle age, a trend that continues as they get older. To overcome this, implementing exercise routines to maintain lean muscle becomes more important. Klinedinst said exercising, especially resistance training, is essential for middle-aged women, who naturally tend to have less muscle mass than men.

The study also looked at whether or not changes in immune system activity could explain links between fat or muscle and fluid intelligence. Previous studies have shown that people with a higher body mass index (BMI) have more immune system activity in their blood, which activates the immune system in the brain and causes problems with cognition. BMI only takes into account total body mass, so it has not been clear whether fat, muscle, or both jump-start the immune system.

In this study, in women, the entire link between more abdominal fat and worse fluid intelligence was explained by changes in two types of white blood cells: lymphocytes and eosinophils. In men, a completely different type of white blood cell, basophils, explained roughly half of the fat and fluid intelligence link. While muscle mass was protective, the immune system did not seem to play a role.

While the study found correlations between body fat and decreased fluid intelligence, it is unknown at this time if it could increase the risk of Alzheimer's disease.

"Further studies would be needed to see if people with less muscle mass and more fat mass are more likely to develop Alzheimer's disease, and what the role of the immune system is," Klinedinst said.

Starting a New Year's resolution now to work out more and eat healthier may be a good idea, not only for your overall health, but to maintain healthy brain function.

"If you eat alright and do at least brisk walking some of the time, it might help you with mentally staying quick on your feet," Willette said.

EAST LANSING, Mich. - The emergence of smart cars has opened the door to limitless possibilities for technology and innovation - but also to threats beyond the car itself. New research from Michigan State University is the first to apply criminal justice theory to smart vehicles, revealing cracks in the current system leading to potential cyber risks.

"Automotive cybersecurity is an area we don't understand well in the social sciences. While there are groups of computer scientists and engineers digging into some of the issues, the social aspects are extremely relevant and under-examined," said Thomas Holt, professor of criminal justice at MSU. "As the technology gets greater market share, it's critical to get ahead of the curve before there are issues we can't rein in."

As vehicles become smarter and more connected to WiFi networks, hackers will have more opportunities to breach vehicle systems. Connecting your smartphone through a USB port can give a hacker backdoor access to data from both your phone and your car. Additionally, Google Android users who can download apps from unverified sites are even more at-risk.

The research, published in the Journal of Crime and Justice applied Routine Activities Theory, used a popular criminal justice framework, to current forms of vehicle security and provided recommendations for manufacturers and owners to improve safety.

"The risk with vehicles isn't just personal data - though that is still a real concern," Holt said. "Say the car is compromised and a hacker alters certain alert systems that tell a driver when tire pressure is low or so the emergency brake sensory systems don't kick in. That could lead to loss of life."

The theory Holt applied says that in order for a criminal to act three things need to come together: a motivated offender, a suitable target and a lack of guardian. In the context of vehicle security, he said that motivators and targets are clear, but the presence of a guardian was where vehicles fell short.

"Where we found holes was surprising: there's no one technically responsible for these vehicles' central computer systems," Holt said. "The automotive and equipment manufacturers need to recognize that as it stands, they serve as the guardians in the space, and the onus is on them. They need to take the lead in thinking more critically about data flows, software vendors and how to communicate security with dealerships."

Holt explained that in a traditional automotive context, an equipment failure would lead to a recall of the vehicle to fix the problem. However, cyber security is entirely different.

"It's critical to think beyond thresholds and recalls because cybersecurity isn't a recoverable problem, but rather one that requires constant system patching updates, installations and new codes written," Holt said. "This is more complicated but needs to be an active guardian process."

Similar to how smart phone manufacturers release security updates, the only way to disrupt the current problem is to have guardians that are consistently, actively updating system software.

"Not everyone updates their smartphones when they're supposed to, but customers need to realize that to a certain extent, manufacturers can only do so much. The customer must have a role in protecting their cars as well," Holt said. "We can't expect every vehicle owner to go to a dealership every time there's a security update. But once the guardians find a way to make it more accessible, they'll be the ones responsible for protecting their vehicles - and themselves."

Holt says that it won't be long before all vehicles have smart capabilities. He fears that it will take too many tragic stories of accidents or breaches to get people to act.

"We need to improve the presence of software guardians and better resources; we also need to think about developing policies to protect users, vehicles and customers," Holt said. "There are real benefits to smart cars and autonomous features, but we need to get ahead of the risks before those benefits are lost."

The U.S. economy may be expanding, but it's taking the low road to growth that undermines wellbeing and may cause economic challenges in the future, according a new study published online in the Cambridge Journal of Economics that centers on the way different countries have responded to the growth of women in the labor force.

Stephanie Seguino, professor of Economics at the University of Vermont and co-author of the paper - with Elissa Braunstein of Colorado State University and Rachid Bouhia of the United Nations Conference on Trade and Development - says that, while women's increasing labor force participation has contributed to worldwide economic growth, there are important qualifiers to that success.

At the heart of the new study is an economic concept called "social reproduction," the unpaid and sometimes paid human care work - which often takes the form of parenting - that is required to produce and sustain a vibrant, well socialized labor force.

In the past economists have focused solely on education and training as the key elements of creating productive human capital. But the new paper, building on past work by the authors, cites social reproduction as being equally important to the creation of productive future workers.

Women provide the bulk of labor needed for social reproduction, so their entry into the labor force, while having a positive effect in aggregate, can have potentially negative impacts, the authors say. If governments do not work to redistribute and reduce child- and other care labor, it can mean either a time squeeze for women, who attempt to both work and care for their children and other family members, or a decline in human development, if care work is neglected.

"As women move into labor markets, attention must be paid to supporting and redistributing the burden of social reproduction. Countries that fail to do so pay a price - both in a decline in human welfare and in the slower economic growth that is a consequence of an unproductive, poorly socialized labor force," Seguino said.

The high road not taken

The paper uses a series of metrics - including the gender wage gap, the extent and quality of private market care, the public availability of quality child care and men's contribution to child care - to score countries on their overall commitment to social reproduction.

Fellow travelers with the U.S. on the low road, 12 in all, are Croatia, New Zealand, Israel, and Switzerland. The authors define the low road as one where rising wages and labor force participation for women may stimulate economic growth, but inadequate or expensive substitutes for caring labor for children undermine social reproduction, over-burdening women and compromising their contributions to the economy.

"The shorthand for these countries is 'time squeeze,'" Braunstein said. "Women have no choice but to 'do it all,' which often means they are overworked, or investments in care decline. The result is a huge negative impact on overall welfare."

In the high road countries - which include Norway, Denmark, Finland and France, eight in all - the opposite trends prevail. Women are paid well, there is high quality childcare provided by private entities and the government, and flexible family leave policies allow men to share in the care of children.

"We call these countries, 'gender egalitarian,'" Seguino said, "because women engage in paid work and are paid well, there are quality private and public options for childcare, so they aren't asked to do double duty, and family leave policies allow men to share equally in unpaid labor in the home."

There is some correlation between countries taking the low or high road and their rate of growth. In a working paper, Braunstein, Seguino and Altinger find that the more gender equal the distribution of social reproduction, the faster a country's economic growth.

Economic repercussions

Investing in social reproduction can have clear positive economic consequences, as well as those related to wellbeing. Underinvesting in social reproduction across a society can dramatically impact the quality of the future workforce and curtail economic growth as a result.

"If we're going to take the positive step of moving women to the paid labor force, which is good for them and for the larger economy, we have to do it in such a way that it addresses the inadvertent outcome of the loss of caring labor," Braunstein said.

Among the first and most-documented symptoms of autism spectrum disorder (ASD) is a child's aversion to interaction with others. Specifically, they appear uninterested in social activities and stimuli that would normally attract a young child's attention, such as watching other children play, sing or dance.

In a new study, published online December 17, 2019 in the journal eLife, researchers at University of California San Diego School of Medicine combined a novel vision tracking program with brain imaging to find that ASD toddlers who ignore social stimuli and prefer to look at moving, colorful geometric images, had more severe social symptoms and lower levels of brain activity connecting social and visual attention brain networks.

"This indicates that in a subtype of ASD toddlers with a preference for geometric images rather than pictures of children -- about 20 percent of toddlers with autism -- there is a disconnection between visual and social brain networks. In these ASD toddlers, colorful moving shapes, rather than fun social-emotional stimuli, control neural activity, attention and learning," said senior and corresponding author Karen Pierce, PhD, professor of neurosciences and co-director of the UC San Diego Autism Center of Excellence with co-author Eric Courchesne, PhD, also a professor of neurosciences.

The daily disconnection of social and visual neural networks results in attention, experience and learning to be directed towards low-level, but visually salient stimuli like colorful spinning shapes, said Pierce; this may be a causative factor in the symptoms and observed social impairment in some ASD toddlers. But the findings, she added, may also provide a new avenue for diagnosing and treating ASD in toddlers and young children.

"Currently, when a child receives a diagnosis of autism, he or she is usually referred for a fairly generic treatment based on principles of Applied Behavior Analysis. In the future, following a diagnosis, children might receive more in-depth biological evaluations that provide information about their eye gaze and brain network activation patterns, which could point to more specific treatments," she said.

"It may also be possible that brain imaging and eye tracking could be used together to determine the efficacy of treatment if a second biological evaluation is conducted at some point following a period of treatment."

Pierce and colleagues have been investigating the potential of eye gaze technology in diagnosing and treating ASD for several years. In 2010, for example, they reported that, in a simple one minute eye tracking test, infants as young as 14 months who preferred movies of geometric shapes more often than movies of children dancing and doing yoga were subsequently diagnosed as ASD using a longer, gold-standard behavioral diagnostic test (the "ADOS"). Conversely, typically developing infants and toddlers preferred watching the "social" images.

In this new study, the researchers combined eye tracking (in which a camera monitors and documents where and what a child is looking at on a screen) with functional magnetic resonance imaging (fMRI) data detailing interconnectivity between different brain circuits.

"Basic neuroscience has found that the human brain has many so-called 'resting state' networks, each involved in different sensory, attention, cognitive and social functions. These networks are active even when we are not engaged in any explicit task, even during natural sleep," said Courchesne.

"One social network, the Default Mode Network or DMN, is highly active when we are thinking about ourselves and others. It is thought that abnormalities in the DMN may be central to why individuals with autism have social difficulties. Since experience-dependent mechanisms, such as what someone looks at, drives brain development, understanding what someone visually attends -- social or non-social stimuli -- can provide invaluable information."

Examining the combined data for both ASD toddlers and non-ASD comparison groups, the researchers found less-than-typical neural interaction (hypoconnectivity) between social brain circuitry like the DMN and visual and attention networks in ASD children. The greater the hypoconnectivity, the more severe the social-communication difficulties, particularly in toddlers with geometric-preference ASD.

Pierce said the findings add new information and detail to the still largely mysterious and complex portrait of ASD. "But by combining clinical phenotype information, such as scores on tests of social competency, with brain imaging and eye tracking as we do here, we are developing more accurate, early approaches to diagnosing ASD and identifying brain-eye tracking subtypes. We will soon begin pilot studies to develop targeted treatments for this subtype."

ITHACA, N.Y. - Geologists, examining the desolate Vavilov ice cap on the northern fringe of Siberia in the Arctic Circle, have for the first time observed rapid ice loss from an improbable new river of ice, according to new research in the journal Geophysical Research Letters.

Observing the ice cap over a period of years, the researchers thought they were seeing a glacial surge, a temporary condition in which snow buildup ebbs and flows over long time scales.

But in this area of the world that is frozen for most of the year, that glacial surge grew faster, wider and fanned out. Having shed nearly 11% of its mass - or 9.5 billion tons of ice since 2013, it may become a more-permanent, impactful ice stream, researchers say.

"This is the first documented case of an ice stream being formed. We really didn't expect to see this," said lead author Whyjay Zheng, Cornell University doctoral student. Now, after about six years of study, the stream resembles a triangular-shaped fan, bordered by dark-shaded crevasses. At the wide center channel, the stream ice flows at a relatively high speed - around 3 miles per year.

"In the satellite images, it seems like the entire west wing of the ice cap is just dumping into the sea," Zheng said. "No one has ever seen this before."

Until this ice stream discovery, the only other places where geologists had seen ice streams were Antarctica and Greenland.

"This glacier went from doing basically nothing to doing something very unusual - evolving into an ice stream," said Matthew Pritchard, professor of earth and atmospheric sciences and a fellow at the Cornell Atkinson Center for Sustainability.

Could the stream be a result of climate change? Yes, Pritchard said, as a portion of the surface of the Vavilov ice cap melts each summer. The ice cap can be compared to much larger marine ice sheets that reach the ocean, which can be eroded by warm water and become unstable when supporting ice shelves are lost.

Once the frozen support collapses, the researchers said, ice streams may form, which allows the ice to flow into the ocean in a surprisingly short time.

Pritchard said this ice stream's relationship to global warming is "hard to ignore," although researchers are still puzzled by its existence. "The Vavilov ice cap is not a place where warming has hit very hard," he said. "Yet we're still seeing this change. It's a new river of ice we're trying to understand."

Zheng points out that mass lost at the Vavilov ice cap is no longer recoverable.

"This is offering scientists another clue as to what happens during global warming. Now once the ice is lost, it is lost," he said. "Suddenly, we have more water in the oceans."

CAMBRIDGE, MA -- It's estimated that there are approximately 80,000 industrial chemicals currently in use, in products such as clothing, cleaning solutions, carpets, and furniture. For the vast majority of these chemicals, scientists have little or no information about their potential to cause cancer.

The detection of DNA damage in cells can predict whether cancer will develop, but tests for this kind of damage have limited sensitivity. A team of MIT biological engineers has now come up with a new screening method that they believe could make such testing much faster, easier, and more accurate.

The National Toxicology Program, a government research agency that identifies potentially hazardous substances, is now working on adopting the MIT test to evaluate new compounds.

"My hope is that they use it to identify potential carcinogens and we get them out of our environment, and prevent them from being produced in massive quantities," says Bevin Engelward, a professor of biological engineering at MIT and the senior author of the study. "It can take decades between the time you're exposed to a carcinogen and the time you get cancer, so we really need predictive tests. We need to prevent cancer in the first place."

Engelward's lab is now working on further validating the test, which makes use of human liver-like cells that metabolize chemicals very similarly to real human liver cells and produce a distinctive signal when DNA damage occurs.

Le Ngo, a former MIT graduate student and postdoc, is the lead author of the paper, which appears today in the journal Nucleic Acids Research. Other MIT authors of the paper include postdoc Norah Owiti, graduate student Yang Su, former graduate student Jing Ge, Singapore-MIT Alliance for Research and Technology graduate student Aoli Xiong, professor of electrical engineering and computer science Jongyoon Han, and professor emerita of biological engineering Leona Samson.

Carol Swartz, John Winters, and Leslie Recio of Integrated Laboratory Systems are also authors of the paper.

Detecting DNA damage

Currently, tests for the cancer-causing potential of chemicals involve exposing mice to the chemical and then waiting to see whether they develop cancer, which takes about two years.

Engelward has spent much of her career developing ways to detect DNA damage in cells, which can eventually lead to cancer. One of these devices, the CometChip, reveals DNA damage by placing the DNA in an array of microwells on a slab of polymer gel and then exposing it to an electric field. DNA strands that have been broken travel farther, producing a comet-shaped tail.

While the CometChip is good at detecting breaks in DNA, as well as DNA damage that is readily converted into breaks, it can't pick up another type of damage known as a bulky lesion. These lesions form when chemicals stick to a strand of DNA and distort the double helix structure, interfering with gene expression and cell division. Chemicals that cause this kind of damage include aflatoxin, which is produced by fungi and can contaminate peanuts and other crops, and benzo[a]pyrene, which can form when food is cooked at high temperatures.

Engelward and her students decided to try to adapt the CometChip so that it could pick up this type of DNA damage. To do that, they took advantage of cells' DNA repair pathways to generate strand breaks. Typically, when a cell discovers a bulky lesion, it will try to repair it by cutting out the lesion and then replacing it with a new piece of DNA.

"If there's something glommed onto the DNA, you have to rip out that stretch of DNA and then replace it with fresh DNA. In that ripping process, you're creating a strand break," Engelward says.

To capture those broken strands, the researchers treated cells with two compounds that prevent them from synthesizing new DNA. This halts the repair process and generates unrepaired single-stranded DNA that the Comet test can detect.

The researchers also wanted to make sure that their test, which is called HepaCometChip, would detect chemicals that only become hazardous after being modified in the liver through a process called bioactivation.

"A lot of chemicals actually are inert until they get metabolized by the liver," Ngo says. "In the liver you have a lot of metabolizing enzymes, which modify the chemicals so that they become more easily excreted by the body. But this process sometimes produces intermediates that can turn out to be more toxic than the original chemical."

To detect those chemicals, the researchers had to perform their test in liver cells. Human liver cells are notoriously difficult to grow outside the body, but the MIT team was able to incorporate a type of liver-like cell called HepaRG, developed by a company in France, into the new test. These cells produce many of the same metabolic enzymes found in normal human liver cells, and like human liver cells, they can generate potentially harmful intermediates that create bulky lesions.

Enhanced sensitivity

To test their new system, the researchers first exposed the liver-like cells to UV light, which is known to produce bulky lesions. After verifying that they could detect such lesions, they tested the system with nine chemicals, seven of which are known to lead to single-stranded DNA breaks or bulky lesions, and found that the test could accurately detect all of them.

"Our new method enhances the sensitivity, because it should be able to detect any damage a normal Comet test would detect, and also adds on the layer of the bulky lesions," Ngo says.

The whole process takes between two days and a week, offering a significantly faster turnaround than studies in mice.

The researchers are now working on further validating the test by comparing its performance with historical data from mouse carcinogenicity studies, with funding from the National Institutes of Health.

They are also working with Integrated Laboratory Systems, a company that performs toxicology testing, to potentially commercialize the technology. Engelward says the HepaCometChip could be useful not only for manufacturers of new chemical products, but also for drug companies, which are required to test new drugs for cancer-causing potential. The new test could offer a much easier and faster way to perform those screens.

"Once it's validated, we hope it will become a recommended test by the FDA," she says.

CHARLOTTESVILLE, VA (DECEMBER 17, 2019). Spine surgeons from seven institutions in Sapporo, Hokkaido, Japan, conducted a multicenter, prospective study of spine surgeries performed in patients 80 years of age and older. Although the overall perioperative complication rate was high--20%, there were no major systemic complications and no deaths in the patients. The surgeons conclude that spine surgery is safe in this age group.

Detailed findings of this study can be found in a new article, "Perioperative complications of spine surgery in patients 80 years of age or older: a multicenter prospective cohort study," by Takamasa Watanabe, MD, and colleagues, published today in the Journal of Neurosurgery: Spine.

The world's population is steadily growing older. This can be seen most readily in Japan, where elderly people (ages 65 years and older) currently make up a quarter of the total population; that proportion is expected to reach one-third by 2050. The aging population in other countries is also growing. Along with increased age comes a variety of age-related health problems; degenerative spine diseases constitute a common health problem in older persons.

Spine surgery can improve quality of life in many patients with damaged or deteriorating spinal components. This is true for older patients as well as for younger ones. But what about patients in the upper range of elderly, those 80 years of age or older? Is spine surgery advisable in this group and what risks does it carry?

The authors of this study conducted a prospective multicenter study with two goals: 1) determine what perioperative complications of spine surgery are associated with patients in this advanced-age group and 2) investigate the risk factors for perioperative systemic complications.

Seven spine centers with board-certified spine surgeons participated in the study. The patient group consisted of 270 patients, 80 years or older, who underwent elective spine surgery in 2017. (Patients with tumors, infection, or trauma were not included.)

Perioperative complications were defined as adverse events occurring during surgery or within 30 days postoperatively. Complications were separated into those occurring at the surgical site and those that were systemic.

The total perioperative complication rate in the study was 20% (67 complications in 54 patients). Complications at the surgical site occurred in 22 patients (8.1%), and minor systemic complications (anemia, delirium, or urinary tract infection) occurred in 40 patients (14.8%). No patient experienced a major systemic complication (one that could be potentially life-threatening or lead to prolonged hospitalization), and no patient died. The rate of repeated operations was 4.1%.

To identify risk factors for perioperative complications, the authors examined surgical factors (operative level, number of spinal levels treated, type of surgery, length of surgery, and estimated blood loss) as well as patient demographics (age, sex, and body mass index) and preoperative health status.

Each patient's preoperative health status was determined by using the following measurements: the Charlson Comorbidity Index (predicts survival based on comorbidities); the American Society of Anesthesiologists Physical Status Classification System (used to assess the patient's general condition); the Eastern Cooperative Oncology Group Performance Status (ECOG-PS) (used to evaluate patients' ability to take care of themselves); the presence of sarcopenia (loss of muscle mass and strength); and the Geriatric Nutritional Risk Index (used to evaluate nutritional risk).

Both the univariate and multivariate analyses identified spine surgery involving instrumentation (for example, inclusion of plates and screws), operations lasting more than 180 minutes, and the ECOG-PS (limited activities of daily living) as significant risk factors for minor systemic perioperative complications.

The authors suggest that spine surgeons be aware of these risk factors when preparing for surgery in this advanced-age patient group.

Older age itself, the presence of comorbidities, and being at nutritional risk were not found to be risk factors in this study. In addition, there were no severe complications. On the basis of their findings, the authors conclude that it is safe to perform spine surgery in patients of advanced age.

Spread across the globe, from Central and South America to Japan, non-human primates have a toehold that almost spans the tropics, but they never made it to Australia. Christofer Clemente, from the University of the Sunshine Coast, Australia, explains that a marsupial got to grips with life in the trees instead. Equipped with two thumbs on their grasping hands, koalas (Phascolarctos cinerus) rarely descend to the ground and appear to be as comfortable with heights as apes and monkeys. Yet it wasn't clear whether the cuddly Antipodeans use the same movement strategies as primates for negotiating their arboreal homes. Intrigued, Joshua Gaschk, Celine Frère and Clemente visited the nearby Queensland Zoo (Wildlife HQ) to film koalas' movements in 3D as they clambered around their enclosure. They publish their discovery that koalas move like other marsupials when on the ground but manoeuvre through trees like apes in Journal of Experimental Biology at https://jeb.biologists.org.

'Some days were more exciting than others in terms of koala activity; they do a lot of sleeping', chuckles Clemente, who recalls that the marsupials were most animated at feeding time when he visited them in the zoo. In addition, the animals were reluctant to walk on the ground, ascending the nearest trunk to find a comfy perch as soon as the zookeepers deposited them on the floor; they even tried climbing the scientists' camera tripods to get above ground level. In addition, Gaschk had to make sure that the cameras were properly synchronised and calibrated, waving a 24 cm long stick in the area that both cameras were focused on, so that he could accurately determine the position of each animal's limbs as they clambered about.

Eventually, after months of painstakingly digitising the animals' manoeuvres, Gaschk focused in on 198 strides - ranging from 47 on the ground to 62 ascending and descending a slope and 89 along a narrow horizontal beam - and realised that despite their extremely distant relationship, the koalas' climbing movements are very similar to those of primates. The marsupials make sure that the diagonally opposed hand and foot (the right hand and left foot, or the left hand and right foot) are always in contact with the branch for stability, while taking longer and slower light-footed steps to make sure that they don't lose balance. 'This specific gait pattern, which is linked to greater stability, is rarely seen outside of primates', says Clemente, adding that the koalas, like primates, depend heavily on their hands and feet to grip on tightly. However, the marsupials were not as fleet of foot as nimble primates, only managing a top speed of 0.7 m/s (2.5 km/h) as they climbed.

In addition, Gaschk analysed the koalas' manoeuvres on the ground, which turned out to be more similar to those of other marsupials, which bound like rabbits, synchronising their hind feet to hit the ground at the same moment. And when he calculated the koalas' top speed on the flat, they were up to four times faster than when climbing through the tree tops, reaching speeds of up to 2.8 m/s (~10 km/h).

In short, koalas move like marsupials on the ground, but they have converged on the same strategies as primates when clambering through trees. Clemente also admits that he was surprised by the koalas' agility as they manoeuvred between branches. 'We occasionally saw leaps of over 1 m from branch to branch, or a koala moving along a branch while hanging underneath just using their forelimbs', he recalls. But Clemente warns that koalas are coming under increasing risk as we destroy more of their precious habitat and says, 'We need to do more to make our urban areas more koala friendly by improving the connectivity between remaining trees'.

WEST LAFAYETTE, Ind. - A wearable monitoring device to make treatments easier and more affordable for the millions of people with swallowing disorders is about to be released into the market.

Georgia A. Malandraki, an associate professor of speech, language, and hearing sciences in Purdue University's College of Health and Human Sciences, and Chi Hwan Lee, an assistant professor of biomedical engineering and mechanical engineering in Purdue's College of Engineering, founded Curasis LLC and serve as an acting chief executive officer and chief technology officer, respectively. They started the company to commercialize their wearable technology and move it as quickly as possible to clinics and people with swallowing difficulties.

A video about the technology is available at https://www.youtube.com/watch?v=IPY-ytpkGck. The technology is presented in the Dec. 13 edition of Science Advances.

"We want to provide a reliable, patient-friendly and affordable way to treat the millions of people with swallowing disorders," Malandraki said. "Many devices to help these people are expensive, not able to be taken home and not accessible in many rural areas."

The researchers created a skin-mountable sensor sticker that attaches firmly to the neck area and is connected with small cables to a wireless transmitter unit.

The skin-mountable sensor sticker measures and records muscle activity and movement associated with swallowing. The information is then sent wirelessly by a separate unit clipped on the wearer's shirt to software that stores it for later analysis by a doctor.

Successful completion of a swallow requires the precise coordination of more than 30 pairs of muscles of the head and neck, six pairs of cranial nerves, and complex circuitry in the brainstem and several brain areas. Any disruption in these pathways can result in severe swallowing disorders.

More than 9 million adults and more than 500,000 children experience severe swallowing disorders each year in the U.S.

"Our device is unique in that we specifically created it to work well with the small and intricate muscles associated with swallowing events," Lee said. "The sensor sticker is stretchable and flexible to work well with the skin and curvilinear head and neck shape, while the connected unit has electronic chips and more rigid components."

The sensor stickers are disposable, designed with inexpensive components and meant to be used about 10 times before they are thrown away.

Malandraki and Lee have completed pre-clinical tests of the device and are currently conducting clinical trials. They are working with the Purdue Research Foundation Office of Technology Commercialization on patenting their technology. They are seeking additional partners. For more information, contact the Office of Technology Commercialization at otcip@prf.org and reference track code 2016-LEE-67542.

They also have worked closely with the Purdue Foundry, a commercialization hub in Purdue's Burton D. Morgan Center for Entrepreneurship. Anne Smith, who retired as a distinguished professor in speech, language, and hearing sciences, serves as a senior advisor to the Curasis team.

The impact of animal-assisted interventions for both patients and health services could be substantial, but more rigorous research is needed, says Dr Elena Ratschen and Professor Trevor Sheldon from the University of York.

Dr Elena Ratschen from the Department of Health Sciences, commenting in an editorial for the BMJ, also says more consideration needs to be given to animal welfare when involving animals of various species in therapeutic activities. The use of virtual reality interventions and robotic pet use should be explored in some contexts.

Healthcare settings such as acute inpatient wards, rehabilitation and psychiatric units, hospices, and dementia care homes open their doors to animals and their handlers every day, aiming to improve patient wellbeing.

Animal-assisted interventions are rapidly expanding in the UK but are largely unregulated. In animal-assisted therapy, a specifically trained animal is incorporated systematically in a treatment plan delivered by a healthcare professional. By contrast, animal-assisted activities are usually led by volunteers and focus more broadly on the presence of an animal, offering opportunities for patients to engage with the animal spontaneously, e.g. during dog visits to hospital ward.

Most animals used in therapy sessions and visits are dogs, although horses, cats, rabbits, guinea pigs and other species can also be found. Many handlers are pet owners volunteering for charities, but some NHS trusts now employ their own therapy teams with highly trained dogs and expert handlers.

Scientific studies have reported promising findings for a range of psychosocial, emotional, and physiological outcomes when animal-assisted interventions have been used. For example, evidence suggests that weekly animal-assisted activities with dogs--such as stroking, playing with, and talking to or about the dog--can have positive effects on the behavioural and psychological symptoms of dementia. However, the scientific evidence related to animal-assisted interventions in healthcare is overall limited, which poses a potential problem in view of expanding practice.

Dr Ratschen said: "The human-animal bond is powerful. Generating robust evidence on how best to harness it could result in substantial gains for patients and health services. Conversely, failure to advance the evidence base is likely to result in waste of scarce resources and poor, potentially unethical, and harmful practice.

"Animal assisted interventions are inherently complex, involving highly individualised interactions between the recipient, the animal, health and social care professionals, and potentially the handler. These complexities are not fully understood. A more thorough understanding of the conditions within which animal assisted interventions can be provided most safely, effectively, cost effectively, and ethically is needed along with identification of the contexts in which virtual reality or robotic pet interventions offer potential alternatives.

Professor Sheldon added: "The suitability of different animal species, how to select individual animals within species for example, based on character traits, and training requirements for different contexts should also be explored, along with optimal monitoring of animal welfare and related risk.

"Although tools to measure or monitor welfare and risk in interventions with dogs are now emerging, further work across species is needed urgently."
The University of York, in close collaboration with partner organisations, is working towards developing a national centre for human-animal interactions and health research.

UNIVERSITY PARK, Pa. -- Disruption of certain DNA structures -- called topologically associating domains, or TADs -- is linked with the development of disease, including some cancers. With its newly created algorithm that quickly locates and helps elucidate the complex functions of TADs, an international team of researchers is making it easier to study these important structures and help prevent disease.

"On your DNA you have genes and regulatory elements -- such as promotors and enhancers -- that control gene expression, but these two things can be far away from each other," said Qunhua Li, associate professor of statistics, Penn State. "Similar to a dresser drawer that keeps your clothes organized and available for use, TADs bring genes together with their regulatory elements, which enables them to begin the process of gene expression."

Gene expression is the process by which the information encoded in DNA gives rise to observable traits.

According to Ross Hardison, T. Ming Chu Professor of Biochemistry and Molecular Biology, Penn State, disruption of the boundaries that form TADs can expose genes to the wrong regulatory elements and lead to aberrant gene expression that can result in the initiation of cancer, for example.

"This algorithm will help us better understand how these important structures function to prevent disease, which can take us one step further toward finding solutions," he said.

Called OnTAD, the team's computational algorithm rapidly identifies the locations of TADs in the genome and enables examination of their internal architectures, which are important for understanding their biological functions. The researchers describe their work today (Dec. 18) in Genome Biology.

OnTAD refers to "optimized nested TAD caller. According to Hardison, the "nesting" or hierarchy of DNA interactions is analogous to the different levels of organization in a city.

"Think about New York City, with its boroughs, neighborhoods within boroughs, and street locations within neighborhoods. Each level of organization is nested within a higher level," he explained. "Just like you are more likely to interact with someone on the same street rather than someone in another borough, DNA interactions are more frequent within the inner-most nested TADs. This is important because interactions among DNA segments -- such as genes and enhancers -- are needed for proper gene regulation. The OnTAD algorithm rapidly and efficiently reveals these levels of organization in DNA interactions."

He added that by working within this hierarchical view of DNA interactions, he and his colleagues learned that the more densely coiled the DNA is inside TADs the greater the gene expression, likely due to the fact that more genes are brought into contact with their regulatory elements.

"As we better understand how DNA interactions function in normal gene regulation, we can be better prepared to uncover how mutations in DNA can alter those interactions that can lead to incorrect gene expression and influence the development of cancers and other diseases."

Li noted that pre-existing methods have focused solely on identifying the locations of TADs, with little investigation of the biological functions of hierarchical organization inside TADs in gene regulation.

In addition to revealing increased gene expression in hierarchical TADs, OnTAD showed that hierarchical TADs are characterized by more active epigenetic states. Epigenetic processes control cell memory and identity; for example, ensuring that kidney cells behave as kidney cells and not as liver cells.

"These results demonstrate that OnTAD is a powerful tool for revealing different levels of DNA organization across a genome," said Li. "It should facilitate improved investigations into the roles of this organization in gene regulation."