Culture

LA JOLLA, CA--A family of proteins that sense mechanical force--and enable our sense of touch and many other important bodily functions--also are essential for proper root growth in some plants, according to a study led by scientists at Scripps Research and Howard Hughes Medical Institute (HHMI).

The discovery, published in the points to an ancient evolutionary origin for the PIEZO proteins, which until now had mainly been characterized in animals. This advance in basic biology may also lead to new strategies for improving crop yields, the researchers say.

"Our finding that PIEZO proteins work as transducers of mechanical forces in plants, as well as animals, suggests the broad importance of these proteins for living organisms on Earth," says lead author Seyed Ali Reza Mousavi, PhD, a postdoctoral research associate in the Scripps Research laboratory of Ardem Patapoutian, PhD.

"It's remarkable that evolution has utilized the same type of molecule for us to sense touch and for plant roots to sense the hardness of soil," says Patapoutian, professor and Presidential Endowed Chair in Neurobiology at Scripps Research and an investigator at HHMI.

Patapoutian, the senior author of the study, is credited with the discovery of PIEZO proteins about a decade ago--an accomplishment that earned him the 2020 Kavli Prize in Neuroscience and many other awards. The discovery led to a host of additional findings that have shed light on how to a range of medical conditions, from heart failure to chronic pain.

Sensing physical force

PIEZO proteins have little resemblance to any other family of biological proteins. In mammals--the only large class of animals in which they have been studied much--they form striking, propeller-like structures in the outer membranes of cells.

When stretched or pressed beyond a threshold, these structures allow charged molecules, called ions, to flow into or out of their host cells.

The two PIEZO proteins in mammals, PIEZO1 and PIEZO2, underlie a wide variety of functions that require this conversion of mechanical force to cellular signals--functions including the sense of touch, the sense of body and limb positions that enables balance, the sense of bladder fullness and the regulation of blood pressure.

Patapoutian's lab and others have found PIEZO-type proteins, with apparent mechanical sensor functions, in other animals including Drosophila fruit flies.

An important role in the plant kingdom

When in the long history of life on Earth did these unique, versatile proteins evolve? To help address that question, Mousavi and other members of Patapoutian's team examined Arabidopsis thaliana, a weedy relative of the mustard plant that's a standard lab model for plant biology research. Arabidopsis's genome includes a gene encoding a PIEZO-type protein, hinting that these proteins work as mechanosensors in the plant kingdom, too.

The scientists first examined the locations in the plant where the protein, PZO1, is made, and found it concentrated in the root tips. Deleting the PZO1 gene, they observed that the Arabidopsis plants grew shorter roots. In a lengthy set of further experiments, they found that PZO1 in root tip cells responds to mechanical stimuli with ion flows--which establishes it as a mechanosensor like its mammalian counterparts.

Exactly how PZO1's mechanosensing abilities help roots grow remains a mystery. But Mousavi, Patapoutian and colleagues suspect that it helps root tip cells sense and adjust themselves to the potentially strong mechanical forces they encounter as the root tries to penetrate soils--especially drier, harder soils.

"If the activity of PZO1 increases, it might help plants expand their root systems in dry conditions and get better access to water," Mousavi says. If that proves to be the case, boosting PZO1 activity could be a way of increasing crop yields in difficult soil conditions, he says.

Mousavi is now trying to clarify PZO1's precise function in Arabidopsis with experiments in real-world conditions. He also hopes to study the role of PIEZO-type proteins in food crops including maize and rice.

DALLAS, May 13, 2021 -- Higher body mass index (BMI) in adolescence is associated with a significantly higher risk of first ischemic stroke in adults under age 50 regardless of whether they had Type 2 diabetes, according to new research published today in Stroke, a journal of the American Stroke Association, a division of the American Heart Association.

While rates of adolescent obesity and stroke among adults under the age of 50 years continue to rise around the world, the precise link between the two conditions is still not fully understood.

"Adults who survive stroke earlier in life face poor functional outcomes, which can lead to unemployment, depression and anxiety," said study co-author Gilad Twig, M.D., M.P.H., Ph.D., an associate professor in the Medical Corps of the Israel Defense Forces and the department of military medicine, Faculty of Medicine of The Hebrew University in Jerusalem, Israel. "The direct and indirect costs attributed to stroke prevention and care are high and expected to keep increasing since the rate of stroke continues to rise."

This study specifically analyzed adolescent BMI and first stroke before the age of 50 among 1.9 million men and women (ages 16 to 20; 58% men; 84% born in Israel) from two nationwide databases: the Israel Defense Forces and the Israeli National Stroke Registry. All the participants in the database had undergone one complete medical exam between 1985 and 2013.

Standard BMI groups are underweight (less than 5th percentile), low-normal BMI (5th to 49th percentile), high-normal BMI (50th to 84th percentile), overweight (85th to 94th percentile), and obese (greater than 95th percentile). Details on percentile BMI measures by gender are in the article.

During the follow-up period, for all 1.9 M participants between 2014 and 2018, researchers found:

Overall, 1,088 strokes occurred (921 ischemic strokes, 167 hemorrhagic strokes), and the average age at the time of the stroke was 41. Adolescent BMI was directly related to the risk of first ischemic stroke.

Compared to participants in the low-normal BMI group, adolescents who were in the overweight category had a 2-times higher stroke risk before the age of 50, and adolescents with obesity had a 3.4-times higher risk.

Even adolescents with BMIs in the high-normal range were more likely to have a stroke before age 50 compared to those in the low-normal BMI group.

After accounting for Type 2 diabetes, adolescents who were in either the overweight or obesity category still had a higher risk of stroke (1.6-times and 2.4-times, respectively) compared to people who had BMI values within the normal range.

Despite overweight and obesity during adolescence being a common problem, researchers were surprised to find that Type 2 diabetes did not explain the higher risk for ischemic stroke, which occurred even before the age of 30 in some cases. Current medical literature has shown that having a stroke early in life may lead to recurrent stroke, heart attack, long-term care and premature death, Twig noted.

"Our findings underscore the importance of effective treatment and prevention of high normal and excessively high BMI during adolescence," Twig said. "Our study is also the first to show that the risk of stroke associated with higher BMI values is the same for both men and women."

A major limitation of the study is that BMI data at follow-up were not available for all participants, which meant that researchers were unable to assess the contribution of obesity over time to stroke risk and to determine the independent risk of BMI during adolescence.

It's a tough time to be a shark. Pollution, industrialized fishing, and climate change threaten marine life, and the populations of many top ocean predators have declined in recent years. In addition to studying sharks in the wild, scientists working to save sharks rely on ones living in zoos and aquariums so that they can help build breeding programs and learn more about the conditions sharks need to thrive. One important way the scientists do that is by playing matchmakers to the sharks, pairing up individuals in ways that increase genetic diversity. In a new study in Scientific Reports, scientists undertook the largest-ever effort to artificially inseminate sharks.Their work resulted in 97 new baby sharks, including ones whose parents live on opposite sides of the country and a few that don't have fathers at all.

"Our goal was to develop artificial insemination as a tool that could be used to help support and maintain healthy reproducing populations of sharks in aquariums," says Jen Wyffels, the paper's lead author who conducted the research for this paper with the South-East Zoo Alliance for Reproduction & Conservation and is currently a researcher at the University of Delaware.

"Moving whole animals from one aquarium to another to mate is expensive and can be stressful for the animal, but now we can just just move genes around through sperm," says Kevin Feldheim, a researcher at Chicago's Field Museum and a co-author of the study who led the DNA analysis of the newborn sharks to determine their parentage.

Figuring out shark parentage can be tricky because shark reproduction isn't always straightforward. In some species, female sharks can store sperm for months after mating and they use it for fertilization "on demand", so the father of a newborn shark isn't necessarily the male the mother most recently had contact with. Some female sharks are even capable of reproducing with no male at all, a process called parthenogenesis. In parthenogenesis, the female's egg cells are able to combine with each other, creating an embryo that only contains genetic material from the mother.

To study shark reproduction, the researchers focused on whitespotted bamboo sharks. "When people think of sharks, they picture great whites, tiger sharks, and bull sharks--the big, scary, charismatic ones," says Feldheim. "Whitespotted bamboo sharks are tiny, about three feet long. If you go to an aquarium, they're generally just resting on the bottom." But while bamboo sharks' gentleness and small size make them unlikely candidates for Hollywood fame, those qualities make them ideal for researchers to try to artificially inseminate.

Before attempting artificial insemination, researchers have to make sure that the potential mothers aren't already carrying sperm from a previous rendezvous. "Candidate females are isolated from males and the eggs they lay afterwards are monitored to make sure they are infertile," says Wyffels. Egg-laying sharks regularly lay eggs on a regular schedule, much like chickens, says Wyffels, to the point that they're nicknamed "chickens of the sea." To determine if the eggs are infertile, scientists shine an underwater light through the leathery, rectangular egg cases (called "mermaid's purses") to see if there's a wriggling embryo on top of the yolk. If there are no fertilized eggs for six weeks or more, the shark is ready to be inseminated.

Scientists collected and evaluated 82 semen samples from 19 sharks in order to tell the difference between good and bad samples. Some of the good samples went to nearby females for insemination, while others were kept cold and shipped around and across the country. Once the semen reached Ripley's Aquarium of the Smokies or Aquarium of the Pacific, where a female was waiting, researchers sedated her and placed the semen in her reproductive tract--the procedure took less than ten minutes. All in all, 20 females were inseminated as part of the study.

Baby sharks hatched from fertilized eggs after 4 months of incubation. "The hatchlings are about the size of your hand, and they have distinctive spot patterns that help to tell them apart," says Wyffels. Tissue samples were taken from all the babies, along with their parents, so Feldheim could analyze their DNA at the Field Museum's Pritzker Laboratory for Molecular Systematics and Evolution.

Feldheim developed a suite of genetic markers to determine parentage. "We sequenced the DNA and found sections where the code repeats itself," says Feldheim. "These repeating bits of code serve as signatures, and when we see them in the babies, we match them up to the potential dads." The team found that freshly collected semen was effective in fertilizing eggs in 27.6% of cases; semen that had been cold-stored for 24 or 48 hours had 28.1% and 7.1% success rates, respectively. In the genetic analysis of the offspring, the team also found two instances of parthenogenesis, where the mother reproduced on her own without using the sperm she'd been inseminated with. "These cases of parthenogenesis were unexpected and help illustrate how little we know about the basic mechanisms of sexual reproduction and embryo development among sharks," says Wyffels.

From these preliminary results, the scientists hope to help aquariums expand and manage their shark breeding programs. "There have been other reports on artificial insemination of sharks, but they include very few females. In this study, we're in the double digits and as a result we could investigate different methods for preparing and preserving sperm for insemination" says Wyffels. "And a hatchling from shark parents that live almost 3,000 miles apart from sperm collected days in advance, that's definitely a first."

"One of the goals of this pilot project was to just see if it worked," says Feldheim. "Now, we can extend it to other animals that actually need help breeding, from other species in aquariums to sharks under threat in the wild."

The researchers also note that if studies like these contribute to the conservation of sharks in the wild, it will be largely thanks to aquariums. "We wouldn't know about parthenogenesis in sharks if it wasn't for aquariums," says Feldheim.

"Aquariums allow you to observe the same individual animals over time, and that's very difficult to do in the wild," says Wyffels. "Aquarists have eyes on their animals every day. They pick up on subtle changes in behavior related to reproduction, and they tell us what they see. Research like this depends on that collaboration. We are already taking what we learned from this study and applying it to other species, especially the sand tiger shark, a protected species that does not reproduce often in aquariums."

It is difficult for us to succeed in whatever we set out to do if we lack motivation. We usually need it as a driving force to achieve both short- and long-term goals, from household chores to getting a degree. However, because of the ongoing pandemic, our lifestyles have been subjected to drastic and dynamic changes, and many work- and study-related activities are now carried out online exclusively. This, among other complex factors, have made it difficult for some people to stay focused and motivated, and psychology researchers are trying to find effective and widely applicable solutions to address such problems.

In a recent study published in BMC Psychology, researchers from Ritsumeikan University and the National Institute of Information and Communications Technology (NICT), Japan, have explored a simple strategy to increase motivation in college students by nurturing a positive emotion: gratitude. Many studies have shown that even short "gratitude interventions," which are activities that increase an individual's awareness of feelings of gratitude, can have a lasting positive effect on that person's mood, satisfaction, and well-being. However, based on previous studies, the available evidence on the effect of such interventions on academic motivation is somewhat inconclusive. This prompted the researchers to test the effects of a different type of gratitude intervention: daily gratitude journaling.

"Our main hypothesis was that engaging in an online gratitude journal by writing down up to five things one felt grateful for each day could make students be more aware of their academic opportunities--their 'blessings'--and help them re-evaluate their motives and goals, ultimately improving their motivation," explains Dr. Norberto Eiji Nawa from NICT, first author of the study. They recruited 84 participants, all Japanese college students, and divided them into a control group and an intervention group. Over the course of two weeks, students in both groups had to evaluate aspects of their daily life through online questionnaires each day, but only the intervention group had to keep the online daily gratitude journal. At the start of the intervention and after 1, and 2 weeks, and 1 and 3 months, the participants had to complete the Academic Motivation Scale (AMS), a tried-and-tested tool for measuring different aspects of academic motivation.

The results were certainly promising; through statistical analyses, the researchers found that the gratitude intervention through daily journaling significantly increased the students' academic motivation. Most notably, this robust positive effect was not restricted only to the two-week period of the intervention, as the increased level of academic motivation was maintained even after three months. In addition, through an exploratory analysis, the researchers established that the enhancement in academic motivation was mostly driven by a decrease in "amotivation scores." Amotivation, in this context, refers to the state in which a person perceives that their own actions are irrelevant to the resulting outcomes, leading to feelings of helplessness and incompetence.

Academic motivation can be one of the primary determinants of both academic achievements and satisfaction with school life, and developing widely applicable intervention strategies is critical to foster student growth. "Online interventions have the advantage of being more accessible, scalable and affordable to large portions of the population. Gathering solid evidence to support their deployment will be essential to unleash their true potential in the future," concludes Professor Noriko Yamagishi from Ritsumeikan University. Fortunately, it appears that the positive impact of gratitude interventions extends well beyond the already-documented effects on individual well-being.

This study was partly supported by a research grant from the Ritsumeikan Inamori Philosophy Research Center. This Center aims to promote multidisciplinary research on the management philosophy advocated by Dr. Kazuo Inamori, a prominent Japanese entrepreneur and renowned philanthropist. With this major goal in mind, Professor Yamagishi, alongside Dr. Nawa, have been working on the scientific elucidation of the emotions of "altruism" and "gratitude" from the perspective of cognitive psychology and neuroscience. This particular study was conducted as part of this more overarching research. Until the day these human emotions become clearer, we can safely give this piece of advice: remember to count your blessings.

Scientists have begun the search for extraterrestrial life in the Solar System in earnest, but such life may be subtly or profoundly different from Earth-life, and methods based on detecting particular molecules as biosignatures may not apply to life with a different evolutionary history. A new study by a joint Japan/US-based team, led by researchers at the Earth-Life Science Institute (ELSI) at the Tokyo Institute of Technology, has developed a machine learning technique which assesses complex organic mixtures using mass spectrometry to reliably classify them as biological or abiological.

In season 1, episode 29 ("Operation: Annihilate!") of Star Trek, which aired in 1966, the human-Vulcan hybrid character Spock made the observation "It is not life as we know or understand it. Yet it is obviously alive; it exists." This now 55-year old pop-culture meme still makes a point: how can we detect life if we fundamentally don't know what life is, and if that life is really different from life as we know it?

The question of "Are we alone?" as living beings in the Universe has fascinated humanity for centuries, and humankind has been looking for ET life in the Solar System since NASA's Viking 2 mission to Mars in 1976. There are presently numerous ways scientists are searching for ET life. These include listening for radio signals from advanced civilisations in deep space, looking for subtle differences in the atmospheric composition of planets around other stars, and directly trying to measure it in soil and ice samples they can collect using spacecraft in our own Solar System. This last category allows them to bring their most advanced chemical analytical instrumentation directly to bear on ET samples, and perhaps even bring some of the samples back to Earth, where they can be carefully scrutinised.

Exciting missions such as NASA's Perseverance rover will look for life this year on Mars; NASA's Europa Clipper, launching in 2024, will try to sample ice ejected from Jupiter's moon Europa, and its Dragonfly mission will attempt to land an "octacopter" on Saturn's moon Titan starting in 2027. These missions will all attempt to answer the question of whether we are alone.

Mass spectrometry (MS) is a principal technique that scientists will rely on in spacecraft-based searches for ET life. MS has the advantage that it can simultaneously measure multitudes of compounds present in samples, and thus provide a sort of "fingerprint" of the composition of the sample. Nevertheless, interpreting those fingerprints may be tricky.

As best as scientists can tell, all life on Earth is based on the same highly coordinated molecular principles, which gives scientists confidence that all Earth-life is derived from a common ancient terrestrial ancestor. However, in simulations of the primitive processes that scientists believe may have contributed to life's origins on Earth, many similar but slightly different versions of the particular molecules terrestrial life uses are often detected. Furthermore, naturally occurring chemical processes are also able to produce many of the building blocks of biological molecules. Since we still have no known sample of alien life, this leaves scientists with a conceptual paradox: did Earth-life make some arbitrary choices early in evolution which got locked in, and thus life could be constructed otherwise, or should we expect that all life everywhere is constrained to be exactly the same way it is on Earth? How can we know that the detection of a particular molecule type is indicative of whether it was or was not produced by ET life?

It has long troubled scientists that biases in how we think life should be detectable, which are largely based on how Earth-life is presently, might cause our detection methods to fail. Viking 2 in fact returned odd results from Mars in 1976. Some of the tests it conducted gave signals considered positive for life, but the MS measurements provided no evidence for life as we know it. More recent MS data from NASA's Mars Curiosity rover suggest there are organic compounds on Mars, but they still do not provide evidence for life. A related problem has plagued scientists attempting to detect the earliest evidence for life on Earth: how can we tell if signals detected in ancient terrestrial samples are from the original living organisms preserved in those samples or derived from contamination from the organisms which presently pervade our planet?

Scientists at the Earth-Life Science Institute at the Tokyo Institute of Technology in Japan and the National High Magnetic Field Laboratory (The National MagLab) in the US decided to address this problem using a combined experimental and machine learning computational approach. The National MagLab is supported by the US National Science Foundation through NSF/ DMR-1644779 and the State of Florida to provide cutting-edge technologies for research. Using ultrahigh-resolution MS (a technique known as Fourier-Transform Ion Cyclotron Resonance Mass Spectrometry (or FT-ICR MS)) they measured the mass spectra of a wide variety of complex organic mixtures, including those derived from abiological samples made in the lab (which they are fairly certain are not living), organic mixtures found in meteorites (which are ~ 4.5 billion-year-old samples of abiologically produced organic compounds which appear to have never become living), laboratory-grown microorganisms (which fit all the modern criteria of being living, including novel microbial organisms isolated and cultured by ELSI co-author Tomohiro Mochizuki), and unprocessed petroleum (or raw natural crude oil, the kind we pump out of the ground and process into gasoline, which is derived from organisms which lived long ago on Earth, providing an example of how the "fingerprint" of known living organisms might change over geological time). These samples each contained tens of thousands of discrete molecular compounds, which provided a large set of MS spectra that could be compared and classified.

In contrast to approaches that use the accuracy of MS measurements to uniquely identify each peak with a particular molecule in a complex organic mixture, the researchers instead aggregated their data and looked at the broad statistics and distribution of signals. Complex organic mixtures, such as those derived from living things, petroleum, and abiological samples present very different "fingerprints" when viewed in this way. Such patterns are much more difficult for a human to detect than the presence or absence of individual molecule types.

The researchers fed their raw data into a computer machine learning algorithm and surprisingly found that the algorithms were able to accurately classify the samples as living or non-living with ~95% accuracy. Importantly, they did so after simplifying the raw data considerably, making it plausible that lower-precision instruments, spacecraft-based instruments are often low power, could obtain data of sufficient resolution to enable the biological classification accuracy the team obtained.

The underlying reasons this classification accuracy is possible to remain to be explored, but the team suggests it is because of the ways biological processes, which modify organic compounds differently than abiological processes, relate to the processes which enable life to propagate itself. Living processes have to make copies of themselves, while abiological processes have no internal process controlling this.

"This work opens many exciting avenues for using ultra-high resolution mass spectrometry for astrobiological applications," says co-author Huan Chen of the US National MagLab.

Lead author Nicholas Guttenberg adds, "While it is difficult if not impossible to characterise every peak in a complex chemical mixture, the broad distribution of components can contain patterns and relationships which are informative about the process by which that mixture came about or developed. If we're going to understand complex prebiotic chemistry, we need ways of thinking in terms of these broad patterns - how they come about, what they imply, and how they change - rather than the presence or absence of individual molecules. This paper is an initial investigation into the feasibility and methods of characterisation at that level and shows that even discarding high-precision mass measurements, there is significant information in peak distribution that can be used to identify samples by the type of process that produced them."

Co-author Jim Cleaves of ELSI adds, "This sort of relational analysis may offer broad advantages for searching for life in the Solar System, and perhaps even in laboratory experiments designed to recreate the origins of life." The team plans to follow up with further studies to understand exactly what aspects of this type of data analysis allows for such successful classification.

COLUMBUS, Ohio - A new study's findings dispel the misconception that patients and providers are at high risk of catching COVID-19 at the dentist's office.

SARS-CoV-2 spreads mainly through respiratory droplets, and dental procedures are known to produce an abundance of aerosols - leading to fears that flying saliva during a cleaning or a restorative procedure could make the dentist's chair a high-transmission location.

Ohio State University researchers set out to determine whether saliva is the main source of the spray, collecting samples from personnel, equipment and other surfaces reached by aerosols during a range of dental procedures.

By analyzing the genetic makeup of the organisms detected in those samples, the researchers determined that watery solution from irrigation tools, not saliva, was the main source of any bacteria or viruses present in the spatter and spurts from patients' mouths.

Even when low levels of the SARS-CoV-2 virus were detected in the saliva of asymptomatic patients, the aerosols generated during their procedures showed no signs of the coronavirus. In essence, from a microbial standpoint, the contents of the spray mirrored what was in the office environment.

"Getting your teeth cleaned does not increase your risk for COVID-19 infection any more than drinking a glass of water from the dentist's office does," said lead author Purnima Kumar, professor of periodontology at Ohio State.

"These findings should help us open up our practices, make ourselves feel safe about our environment and, for patients, get their oral and dental problems treated - there is so much evidence emerging that if you have poor oral health, you are more susceptible to COVID," Kumar said.

The study was published Wednesday, May 12, in the Journal of Dental Research.

Previous research has shown that dental-procedure aerosols tend to land on providers' faces and the patient's chest, and can travel as far as 11 feet. But the studies, catching the spray in petri dishes placed on people, equipment and around the room, found only that bacteria existed - they rarely identified the organisms and never determined where they came from. Saliva has been the presumptive source for a long time.

When saliva was considered potentially deadly at the start of the pandemic, Kumar decided a long-term answer was needed to settle the question of whether saliva is the source of dental aerosols.

For the study, the team enrolled 28 patients receiving dental implants and restorations using high-speed drills or ultrasonic scaling procedures in Ohio State's College of Dentistry between May 4 and July 10, 2020. Researchers collected samples of saliva and irrigant (the water-based cleaning solutions used to flush out the mouth) before each procedure and, 30 minutes after the procedure, aerosol remnants - condensate - from providers' face shields, the patient's bib and an area 6 feet away from the chair.

Kumar and colleagues then put genome sequencing technology to use that wasn't available in the petri-dish days. This allowed them to first characterize the microbial mix in pre-procedure saliva and irrigants, which they could then compare to organisms in the aerosol samples collected later.

With the analytical method they used, the researchers did not need to characterize the microbes - they instead looked for variations in sequences that provided enough information to identify the family of bacteria or viruses to which they belonged.

"Some species that live in your mouth can closely resemble those in water and the environment. Using this method, we don't even have to know the names of these organisms - you can tell whether they are exactly genetically identical or genetically different," Kumar said. "If you use this granular approach to see these very nuanced differences in the genetic code, you can very accurately identify where they're coming from."

No matter the procedure or where the condensate had landed, microbes from irrigants contributed to about 78% of the organisms in aerosols while saliva, if present, accounted for 0.1% to 1.2% of the microbes distributed around the room.

Salivary bacteria were detected in condensate from only eight cases and of those, five patients had not used a pre-procedural mouth rinse. The SARS-CoV-2 virus was identified in the saliva of 19 patients, but was undetectable in aerosols in any of the cases.

The findings are reassuring, but also make sense, Kumar said: Irrigant dilutes saliva - a "thick, viscous" substance - by an estimated 20- to 200-fold, and the research is validated by a 2020 study that reported a less than 1% COVID-19 positivity rate among dentists.

Kumar noted that dentistry has long been at the forefront of infection-control practices in health care. During the pandemic, new protocols have included strengthened ventilation systems, extra aerosol suction equipment, N95 masks and face shields on top of goggles, and extended downtime between patients. She is hopeful this study's findings will make practitioners and patients feel at ease about being in the dentist's office - with continued stringent protection in place.

"Dental surgeons and hygienists are always at the forefront of the war against bacteria in the mouth, and they of course did not feel safe because they are front-line workers surrounded by aerosol," said Kumar, who has a periodontology practice of her own and was one of the procedure operators in the study.

"Hopefully this will set their mind at rest because when you do procedures, it is the water from the ultrasonic equipment that's causing bacteria to be there. It's not saliva. So the risk of spreading infection is not high," she said. "However, we should not lose sight of the fact that this virus spreads through aerosol, and speaking, coughing or sneezing in the dental office can still carry a high risk of disease transmission."

Touchscreens are notoriously difficult to type on. Since we can't feel the keys, we rely on the sense of sight to move our fingers to the right places and check for errors, a combination of efforts we can't pull off at the same time. To really understand how people type on touchscreens, researchers at Aalto University and the Finnish Center for Artificial Intelligence (FCAI) have created the first artificial intelligence model that predicts how people move their eyes and fingers while typing.

The AI model can simulate how a human user would type any sentence on any keyboard design. It makes errors, detects them -- though not always immediately -- and corrects them, very much like humans would. The simulation also predicts how people adapt to alternating circumstances, like how their writing style changes when they start using a new auto-correction system or keyboard design.

'Previously, touchscreen typing has been understood mainly from the perspective of how our fingers move. AI-based methods have helped shed new light on these movements: what we've discovered is the importance of deciding when and where to look. Now, we can make much better predictions on how people type on their phones or tablets,' says Dr. Jussi Jokinen, who led the work.

The study, to be presented at ACM CHI on 12 May, lays the groundwork for developing, for instance, better and even personalized text entry solutions.

'Now that we have a realistic simulation of how humans type on touchscreens, it should be a lot easier to optimize keyboard designs for better typing -- meaning less errors, faster typing, and, most importantly for me, less frustration,' Jokinen explains.

In addition to predicting how a generic person would type, the model is also able to account for different types of users, like those with motor impairments, and could be used to develop typing aids or interfaces designed with these groups in mind. For those facing no particular challenges, it can deduce from personal writing styles -- by noting, for instance, the mistakes that repeatedly occur in texts and emails -- what kind of a keyboard, or auto-correction system, would best serve a user.

The novel approach builds on the group's earlier empirical research, which provided the basis for a cognitive model of how humans type (watch the new four-minute video How to type faster on your phone). The researchers then produced the generative model capable of typing independently. The work was done as part of a larger project on Interactive AI at the Finnish Center for Artificial Intelligence.

The results are underpinned by a classic machine learning method, reinforcement learning, that the researchers extended to simulate people. Reinforcement learning is normally used to teach robots to solve tasks by trial and error; the team found a new way to use this method to generate behavior that closely matches that of humans -- mistakes, corrections and all.

'We gave the model the same abilities and bounds that we, as humans, have. When we asked it to type efficiently, it figured out how to best use these abilities. The end result is very similar to how humans type, without having to teach the model with human data,' Jokinen says.

Comparison to data of human typing confirmed that the model's predictions were accurate. In the future, the team hopes to simulate slow and fast typing techniques to, for example, design useful learning modules for people who want to improve their typing.

The paper, Touchscreen Typing As Optimal Supervisory Control, will be presented 12 May 2021 at the ACM CHI conference.

Gold leaf -- gold metal hammered into thin sheets -- is used by artists and crafters to gild picture frames, artwork and clothing. Despite its luxurious appearance, the material is affordable and available at most craft stores. Now, researchers reporting in ACS Central Science have developed gold leaf electrodes that, in combination with a CRISPR-based assay, could sensitively detect human papillomavirus (HPV) DNA in human samples. The method also could be modified to diagnose other viral infections.

Previous research indicates that about 80% of new cases of sexually transmitted infections, such as HPV and human immunodeficiency virus (known as HIV), take place in low-resource settings. In addition, over 90% of cervical cancer deaths, which are caused mainly by HPV, occur in these regions, according to the World Health Organization. But people in low-resource settings lack the facilities, trained personnel and money to conduct common diagnostic tests, including polymerase chain reaction (PCR) or antibody detection. Therefore, Ariel Furst, Catherine Klapperich and colleagues wanted to develop a simple, affordable point-of-care test.

Using a sheet of 24K gold leaf, an adhesive, a stencil and a razor blade, the researchers made a three-electrode system that provided a readout in the presence of HPV DNA. On the surface of the electrodes, they attached DNA strands tagged with a dye. Then, they amplified DNA from cervical swab samples with a technique called loop-mediated isothermal amplification, which doesn't require expensive PCR machines. They added the amplified DNA, along with a CRISPR Cas12a enzyme engineered to recognize an HPV sequence, to the surface of the electrode. In the presence of HPV DNA, Cas12a became activated, causing the enzyme to cut the dye-tagged DNA sequence, which changed the electrochemical signal. The assay, which costs only about $2.30 total per test (compared with $30-75 for existing tests), accurately detected HPV in cervical swabs from patients. The technology could be adapted to detect any viral infection, including SARS-CoV-2, the researchers say.

The authors acknowledge funding from the Dorf-Ebner Distinguished Faculty Fellow Award, the Boston University Precision Diagnostics Center, the Defense Advanced Research Projects Agency and the National Science Foundation.

The paper with be freely available as an ACS AuthorChoice article on May 12 at 8 a.m. Eastern time here: http://pubs.acs.org/doi/abs/10.1021/acscentsci.1c00186

The American Chemical Society (ACS) is a nonprofit organization chartered by the U.S. Congress. ACS' mission is to advance the broader chemistry enterprise and its practitioners for the benefit of Earth and all its people. The Society is a global leader in promoting excellence in science education and providing access to chemistry-related information and research through its multiple research solutions, peer-reviewed journals, scientific conferences, eBooks and weekly news periodical Chemical & Engineering News. ACS journals are among the most cited, most trusted and most read within the scientific literature; however, ACS itself does not conduct chemical research. As a leader in scientific information solutions, its CAS division partners with global innovators to accelerate breakthroughs by curating, connecting and analyzing the world's scientific knowledge. ACS' main offices are in Washington, D.C., and Columbus, Ohio.

To automatically receive news releases from the American Chemical Society, contact newsroom@acs.org.

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Coal combustion by power plants and industry pollutes the air, causing many governments to implement mitigation actions and encourage cleaner forms of energy. Now, a new study in ACS' Environmental Science & Technology indicates that in China, indoor air pollution from residential coal burning causes a disproportionate number of premature deaths from exposure to tiny, inhalable pollutants known as PM2.5.

In China, coal is still the largest source of energy, although recent mitigation actions have replaced some coal-fired power plants with petroleum- or natural gas-powered plants. Also, many coal-fired power plants and industrial boilers have installed equipment that reduces emissions. However, some households continue to use coal for heating and cooking, especially in rural areas, and the health impacts of this indoor PM2.5 exposure compared with other forms of indoor and outdoor exposure are largely unknown. Therefore, Shu Tao and colleagues wanted to quantify health risks of exposure to indoor and outdoor PM2.5 from coal used in the power, industrial and residential sectors in China from 1974 to 2014.

The researchers compiled data on coal consumption by power plants, industry, and rural and urban residences over the 40-year period. Using atmospheric chemical transport and statistical models, they calculated outdoor and indoor PM2.5 levels. Then, the team used exposure response functions -- mathematical relationships that calculate health effects resulting from specific exposures -- to estimate premature deaths caused by five diseases associated with PM2.5, including lung cancer and heart disease. From 1974 to 2014, the contribution of indoor residential coal use to overall PM2.5 exposure decreased in urban populations but remained steady in rural populations. The researchers calculated that in 2014, residential coal accounted for 2.9% of total energy use in China but 34% of premature deaths associated with PM2.5. The number of premature deaths caused by unit coal consumption in the residential sector was 40 times higher than that in the power and industrial sectors. These results indicate that efforts to reduce residential coal use should be a key focus of future air pollution mitigation actions in China, the researchers say.

The authors acknowledge funding from the Chinese Academy of Sciences and the National Natural Science Foundation of China.

The article will be freely available as an ACS AuthorChoice article on May 12 at 8 a.m. Eastern time here: http://pubs.acs.org/doi/abs/10.1021/acs.est.1c01148.

The American Chemical Society (ACS) is a nonprofit organization chartered by the U.S. Congress. ACS' mission is to advance the broader chemistry enterprise and its practitioners for the benefit of Earth and all its people. The Society is a global leader in promoting excellence in science education and providing access to chemistry-related information and research through its multiple research solutions, peer-reviewed journals, scientific conferences, eBooks and weekly news periodical Chemical & Engineering News. ACS journals are among the most cited, most trusted and most read within the scientific literature; however, ACS itself does not conduct chemical research. As a leader in scientific information solutions, its CAS division partners with global innovators to accelerate breakthroughs by curating, connecting and analyzing the world's scientific knowledge. ACS' main offices are in Washington, D.C., and Columbus, Ohio.

To automatically receive news releases from the American Chemical Society, contact newsroom@acs.org.

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Trained to see patterns by analyzing thousands of chest X-rays, a computer program predicted with up to 80 percent accuracy which COVID-19 patients would develop life-threatening complications within four days, a new study finds.

Developed by researchers at NYU Grossman School of Medicine, the program used several hundred gigabytes of data gleaned from 5,224 chest X-rays taken from 2,943 seriously ill patients infected with SARS-CoV-2, the virus behind the infections.

The authors of the study, publishing in the journal npj Digital Medicine online May 12, cited the "pressing need" for the ability to quickly predict which COVID-19 patients are likely to have lethal complications so that treatment resources can best be matched to those at increased risk. For reasons not yet fully understood, the health of some COVID-19 patients suddenly worsens, requiring intensive care, and increasing their chances of dying.

In a bid to address this need, the NYU Langone team fed not only X-ray information into their computer analysis, but also patients' age, race, and gender, along with several vital signs and laboratory test results, including weight, body temperature, and blood immune cell levels. Also factored into their mathematical models, which can learn from examples, were the need for a mechanical ventilator and whether each patient went on to survive (2,405) or die (538) from their infections.

Researchers then tested the predictive value of the software tool on 770 chest X-rays from 718 other patients admitted for COVID-19 through the emergency room at NYU Langone hospitals from March 3 to June 28, 2020. The computer program accurately predicted four out of five infected patients who required intensive care and mechanical ventilation and/or died within four days of admission.

"Emergency room physicians and radiologists need effective tools like our program to quickly identify those COVID-19 patients whose condition is most likely to deteriorate quickly so that health care providers can monitor them more closely and intervene earlier," says study co-lead investigator Farah Shamout, PhD, an assistant professor in computer engineering at New York University's campus in Abu Dhabi.

"We believe that our COVID-19 classification test represents the largest application of artificial intelligence in radiology to address some of the most urgent needs of patients and caregivers during the pandemic," says Yiqiu "Artie" Shen, MS, a doctoral student at the NYU Data Science Center.

Study senior investigator Krzysztof Geras, PhD, an assistant professor in the Department of Radiology at NYU Langone, says a major advantage to machine-intelligence programs such as theirs is that its accuracy can be tracked, updated and improved with more data. He says the team plans to add more patient information as it becomes available. He also says the team is evaluating what additional clinical test results could be used to improve their test model.

Geras says he hopes, as part of further research, to soon deploy the NYU COVID-19 classification test to emergency physicians and radiologists. In the interim, he is working with physicians to draft clinical guidelines for its use.

The 'missing link' that helped our ancestors to begin communicating with each other through language may have been iconic sounds, rather than charades-like gestures - giving rise to the unique human power to coin new words describing the world around us, a new study reveals.

It was widely believed that, in order to get the first languages off the ground, our ancestors first needed a way to create novel signals that could be understood by others, relying on visual signs whose form directly resembled the intended meaning.

However, an international research team, led by experts from the University of Birmingham and the Leibniz-Centre General Linguistics (ZAS), Berlin, have discovered that iconic vocalisations can convey a much wider range of meanings more accurately than previously supposed.

The researchers tested whether people from different linguistic backgrounds could understand novel vocalizations for 30 different meanings common across languages and which might have been relevant in early language evolution.

These meanings spanned animate entities, including humans and animals (child, man, woman, tiger, snake, deer), inanimate entities (knife, fire, rock, water, meat, fruit), actions (gather, cook, hide, cut, hunt, eat, sleep), properties (dull, sharp, big, small, good, bad), quantifiers (one, many) and demonstratives (this, that).

The team published their findings in Scientific Reports, highlighting that the vocalizations produced by English speakers could be understood by listeners from a diverse range of cultural and linguistic backgrounds. Participants included speakers of 28 languages from 12 language families, including groups from oral cultures such as speakers of Palikúr living in the Amazon forest and speakers of Daakie on the South Pacific island of Vanuatu. Listeners from each language were more accurate than chance at guessing the intended referent of the vocalizations for each of the meanings tested.

Co-author Dr Marcus Perlman, Lecturer in English Language and Linguistics at the University of Birmingham, commented: "Our study fills in a crucial piece of the puzzle of language evolution, suggesting the possibility that all languages - spoken as well as signed - may have iconic origins.

"The ability to use iconicity to create universally understandable vocalisations may underpin the vast semantic breadth of spoken languages, playing a role similar to representational gestures in the formation of signed languages."

Co-author Dr Bodo Winter, Senior Lecturer in Cognitive Linguistics at the University of Birmingham, commented: "Our findings challenge the often-cited idea that vocalisations have limited potential for iconic representation, demonstrating that in the absence of words people can use vocalizations to communicate a variety of meanings - serving effectively for cross-cultural communication when people lack a common language."

An online experiment allowed researchers to test whether a large number of diverse participants around the world were able to understand the vocalisations. A field experiment using 12 easy-to-picture meanings, allowed them to test whether participants living in predominantly oral societies were also able to understand the vocalisations.

They found that some meanings were consistently guessed more accurately than others. In the online experiment, for example, accuracy ranged from 98.6% for the action 'sleep' to 34.5% for the demonstrative 'that'. Participants were best with the meanings 'sleep', 'eat', 'child', 'tiger', and 'water', and worst with 'that', 'gather', 'dull', 'sharp' and 'knife'.

The researchers highlight that while their findings provide evidence for the potential of iconic vocalisations to figure in the creation of original spoken words, they do not detract from the hypothesis that iconic gestures also played a critical role in the evolution of human communication, as they are known to play in the modern emergence of signed languages.

Everyone has at some point been charmed by the sound of a person's voice: but can we believe our ears? What can a voice really reveal about our character? Now an international research team led by the University of Göttingen has shown that people seem to express at least some aspects of their personality with their voice. The researchers discovered that a lower pitched voice is associated with individuals who are more dominant, extrovert and higher in sociosexuality (more interested in casual sex). The findings were true for women as well as for men. The results were published in the Journal of Research in Personality.

The researchers analysed data from over 2,000 participants and included information from four different countries. Participants filled in questionnaires about themselves to measure personality and provided recordings of their voice so that the pitch could be measured using a computer programme. This is the first time that an objective digital measure of voice pitch has been used in a study of this kind, rather than subjective ratings of how "high" or "deep" a voice might sound. The researchers measured "sociosexuality" by collecting responses about sexual behaviour, attitude and desire. They also collected data to provide ratings of dominance and other character traits such as neuroticism, extraversion, openness to experience, agreeableness and conscientiousness. The number of participants helps to confirm the robustness of the findings: the study involves the largest number to date compared to similar research in this theme.

The researchers found that people with lower pitched voices were more dominant, extroverted and higher in sociosexuality (eg were more interested in sex outside a relationship). However, the relationship between voice pitch and other personality traits (such as agreeableness, neuroticism, conscientiousness or openness) seems less clear. It is possible that these traits are not expressed in the pitch of voices. The researchers found no difference between men and women.

"People's voices can make a huge and immediate impression on us," explains Dr Julia Stern, at the University of Göttingen's Biological Personality Psychology Group. "Even if we just hear someone's voice without any visual clues - for instance on the phone - we know pretty soon whether we're talking to a man, a woman, a child or an older person. We can pick up on whether the person sounds interested, friendly, sad, nervous, or whether they have an attractive voice. We also start to make assumptions about trust and dominance." This led Stern to question whether these assumptions were justified. "The first step was to investigate whether voices are, indeed, related to people's personality. And our results suggest that people do seem to express some aspects of their personality with their voice."

This study was conducted as a "registered report" which means it benefits from peer review from other researchers at a very early stage and was accepted for publication independent of the results. It is one of the new indicators of quality being developed to make science more transparent and reliable.

The gopher tortoise (Gopherus polyphemus) is declining because of habitat loss and fragmentation, human interaction including collisions with vehicles, predation by domestic animals, and disease. These long-lived reptiles are found throughout Florida and are affected by various diseases including upper respiratory tract disease. A number of pathogens such as Mycoplasma spp., Herpesvirus, and Ranavirus are known to cause upper respiratory tract disease in gopher tortoises. Chronic disease resulting from these pathogens can lead to reduced reproduction, abnormal growth and development, increased susceptibility to secondary infections and, in some cases, a shorter life span. To date, little is known about the prevalence of these microorganisms in wild tortoises.

This lack of knowledge creates a dilemma for wildlife biologists, conservationists and public policy makers seeking to uphold and improve protections for this threatened species.

Researchers from Florida Atlantic University's Harbor Branch Oceanographic Institute and the Harriet L. Wilkes Honors College in collaboration with Loggerhead Marinelife Center and the University of Florida College of Veterinary Medicine, conducted a comprehensive health assessment of previously unstudied gopher tortoise aggregations at two sites in southeastern Florida.

Results of the study, published in the journal Conservation Physiology, showed that overall, 42.9 percent of all tortoises tested had circulating antibodies to Mycoplasma agassizii, an infectious bacterium that causes upper respiratory tract disease. Researchers detected antibodies to M. agassizii in 29 percent of tortoises at one of the sites and 70 percent at the other site, suggesting that at least one of these tortoise aggregations may be experiencing an outbreak of M. agassizii.

In contrast, none of the tortoises tested positive for Ranavirus or Herpesvirus via polymerase chain reaction (PCR), which represents important baseline data, since these viruses are thought to be emerging pathogens of other tortoise and turtle species.

For the study, researchers collected samples of blood and nasal, oral, and cloacal swabs (digestive, reproductive, and urinary tract openings) from 91 tortoises (48 adults, 35 juveniles and eight hatchlings) captured at FAU Harbor Branch in Fort Pierce in 2019, and Loggerhead Park in Juno Beach during 2018-2019. The samples were analyzed for hematology, plasma protein electrophoretic profiles, and infectious disease testing including Mycoplasma spp. serology and PCR assays for Ranavirus, Herpesvirus, and Anaplasma spp., a tick-borne bacteria of medical importance.

At both study sites, adult tortoises were significantly more likely to have clinical signs of upper respiratory tract disease than juveniles. There was a significant relationship between tortoise size and M. agassizii antibody test results. Physical examination revealed that 19.8 percent of the tortoises had clinical signs consistent with upper respiratory tract disease, including nasal discharge, asymmetrical nares, wheezing, eyelid/conjunctival swelling, and ocular discharge. In addition, 13.2 percent of tortoises had some other form of physical abnormality noted during physical examination, including limb, eye and shell abnormalities or extra scutes on the tortoise's shell.

"The full effect of chronic disease on a long-lived species such as the gopher tortoise may take months to years to manifest in a population," said Annie Page-Karjian, D.V.M., Ph.D., lead author, clinical veterinarian and an assistant research professor, FAU Harbor Branch. "Because the gopher tortoise is one of the most commonly translocated species in North America, it is important to understand pathogen distributions within their populations and to monitor them using standardized techniques so that any changes associated with health problems may be detected over time."

Researchers also found that adult tortoises were significantly more likely than juvenile tortoises to have ticks as well as hemogregarine parasites in their red blood cells. Tortoises with ticks were significantly more likely to have the hemogregarine parasites. Ticks were found on 59 percent and hemoparasites were identified in 30 percent of the tortoises sampled at FAU Harbor Branch, while only a single tick was found, and no hemoparasites were identified in tortoises sampled at Loggerhead Park. These findings are noteworthy because hemogregarines in tortoises are thought to be transmitted by ticks.

"Free-ranging animals typically have higher internal and external parasite burdens and are likely exposed to pathogens more frequently than captive animals, which often are regularly treated with parasiticides and also receive supportive care such as anti-microbials when they are sick," said Page-Karjian. "Long-term studies of these animals and other populations will help us to better understand the consequences of disease and various stressors that impact their behavior and reproductive potential. Additional health assessments and surveillance of pathogens in southeastern Florida's gopher tortoises are warranted."

The study conducted by the University of Turku and the Finnish Institute for Health and Welfare together with an international research team is so far the largest population-level study in the world examining the connection between human gut microbiota and health and mortality in the following decades.

The composition of the research subjects' gut microbiota was analysed from stool samples collected in 2002. The researchers had access to follow-up data on the subjects' mortality until 2017, i.e., close to the present day.

"Many bacterial strains that are known to be harmful were among the enterobacteria predicting mortality, and our lifestyle choices can have an impact on their amount in the gut. By studying the composition of the gut microbiota, we could improve mortality prediction, even while taking into account other relevant risk factors, such as smoking and obesity. The data used in this research make it possible for the first time to study the long-term health impact of the human gut microbiota on a population level," says Teemu Niiranen, Professor of Medicine at the University of Turku, Finland.

Everyone has a unique microbiota

Human microbiota is highly individual and consists of a vast amount of different bacteria and other microorganisms. The bacteria predicting a shorter lifespan were discovered when the researchers compared health records and billions of DNA strands retrieved from the research subjects' microbiota.

"We developed a machine learning algorithm that screened the data for microbial species having a significant association with mortality among the research subjects in the following two decades after the sample was taken," describes Associate Professor Leo Lahti from the University of Turku.

"Finnish population studies are unique in their extent and scope even on a global scale. With new data science methods, we are now able to study more closely the specific connections between microbiota and, for example," ageing and incidence of common diseases, Lahti continues.

Even though the connection between gut microbiota and lifestyle has lately been studied extensively in cross-sectional studies, there are only a few long-term follow-up studies available. Therefore, only a small amount of information has been gained about the connection between microbiota and health in the long term.

The study was based on a sample of over 7,000 Finnish adults. The data are part of the FINRISK 2002 study conducted by the Finnish Institute for Health and Welfare. The research article was published in Nature Communications.

Philadelphia, May 12, 2021 - In recent years there has been an increased interest in the consumption of kefir, a fermented dairy beverage, because there is some evidence that it has health benefits and its affordability. A new study by researchers from the University of Illinois and The Ohio State University, published in JDS Communications, found that 66 percent of the commercial kefir products studied overstated microorganism density and 80 percent contained bacterial species that were not included on the label, potentially misleading consumers.

Senior author Kelly S. Swanson, PhD, University of Illinois, Urbana, IL, USA, believes better quality control of kefir products is required to demonstrate and understand their potential health benefits. "It is important for consumers to know the accurate contents of the fermented foods they consume," Swanson said.

Swanson and his team of researchers bought five kefir products from online vendors and stores in the Urbana, IL area and analyzed two lots of each. Although all five guaranteed specific bacterial species used in fermentation, the team found that no product completely matched its label. All products contained Streptococcus salivarius, and four out of five products contained Lactobacillus paracasei, although they were not included on the labels.

According to Dr. Swanson, classification as a "cultured milk product" by the FDA requires disclosure of added microorganisms. "Regulatory agencies and consumers must continue to scrutinize these products and demand a higher level of accuracy and quality," he explained.

The authors hope this and future studies will call attention to the effect of inaccurate kefir product labeling.