Category: Science

Researchers have discovered that a part of the brain associated with working memory and multisensory integration may also play an important role in how the brain processes social cues.

Previous research has shown that neurons in the ventrolateral prefrontal cortex (VLPFC) integrate faces and voices—but new research, in the Journal of Neuroscience,  shows that neurons in the VLPFC play a role in processing both the identity of the “speaker” and the expression conveyed by facial gestures and vocalizations.

“We still don’t fully understand how facial and vocal information is combined and what information is processed by different brain regions,” says Lizabeth Romanski, associate professor of neuroscience at the Del Monte Institute for Neuroscience at the University of Rochester and senior author of the study. “However, these findings confirm VLPFC as a critical node in the social communication network that processes facial expressions, vocalizations, and social cues.”

The VLPFC is an area of the brain that is enlarged in primates, including humans and macaques. In this study, the Romanski Lab showed rhesus macaques short videos of other macaques engaging in vocalizations/expressions that were friendly, aggressive, or neutral. They recorded the activity of more than 400 neurons in the VLPFC and found that individually, the cells did not exhibit strong categorical responses to the expressions or the identities of the macaques in the videos. However, when the researchers combined the neurons as a population a machine learning model could be trained to decode the expression and identity in the videos based only on the patterns of neural activity, suggesting that neurons were collectively responding to these variables.

Overall, the activity of the population of VLPFC neurons was primarily dictated by the identity of the macaque in the video. These findings suggest that the VLPFC is a key brain region in the processing of social cues.

“We used dynamic, information-rich stimuli in our study and the responses we saw from single neurons were very complex. Initially, it was difficult to make sense of the data,” says Keshov Sharma, lead author of the study. “It wasn’t until we studied how population activity correlated with the social information in our stimuli that we found a coherent structure. For us, it was like finally seeing a forest instead of a muddle of trees.”

Sharma and Romanski hope their approach will encourage others to analyze population-level activity when studying how faces and voices are integrated in the brain.

Understanding how the prefrontal cortex processes auditory and visual information is a cornerstone of the Romanski lab. This process is necessary for recognizing objects by sight, as well as sound, and is required for effective communication. In previous research, the Romanski Lab identified the VLPFC as an area of the brain responsible for maintaining and integrating face and vocal information during working memory. This body of research points to the importance of this brain region within the larger circuit that underlies social communication.

“Knowing what features populations of neurons extract from face and vocal stimuli and how these features are typically integrated will help us to understand what may be altered in speech and communication disorders, including autism spectrum disorders, where multiple sensory stimuli may not combine optimally,” Romanski says.

Additional authors are from the University of Rochester Medical Center, Astrobotic Technology Inc., and the University of Miami School of Medicine.

Support for this research came from the National Institutes of Health, the Schmitt Program for Integrative Neuroscience through the Del Monte Institute for Neuroscience, and the University of Rochester Medical Scientist Training Program (MSTP).

Source: University of Rochester

A study finds that algorithms used by online dating platforms have popularity bias, meaning that they recommend more popular, attractive users over less popular, less attractive users.

The researchers evaluated data from over 240,000 users of a major online dating platform in Asia over three months. They found that a user’s chance of being recommended by the platform’s algorithm increased significantly as their average attractiveness score went up. This suggests the algorithm is biased toward recommending users who are more popular or considered more attractive on the platform.

“Online dating has grown rapidly—especially during the COVID-19 pandemic,” notes coauthor Soo-Haeng Cho, a professor of operations management and strategy at Carnegie Mellon University’s Tepper School of Business. “Even though dating platforms allow users to connect with others, questions regarding fairness in their recommendation algorithms remain.”

The researchers report their findings in Manufacturing & Service Operations Management.

Users join online dating platforms to find matches, but the companies creating the platforms also need to generate revenue. Companies make money through ads, subscriptions, and in-app purchases. For this reason, platforms may seek to keep users engaged on their platforms rather than maximizing their chances of finding the perfect person.

The researchers built a model to analyze the incentives for platforms to recommend popular users more frequently when their goal is to maximize revenue or maximize matches. In their model, they used the unbiased approach (which is when popular and unpopular users find equal chances to be recommended to others) as their benchmark for fairness to compare popular and unpopular users’ matching probabilities. Their analysis shows that unbiased recommendations tend to result in significantly lower revenue for the dating platform and fewer matches. This is because popular users help the platform generate more revenue by boosting users’ engagement (through more likes and messages sent). In addition, popular users help the platform generate more successful matches as long as they do not become so selective that they are seen as being out of reach to less popular users.

The study also found that popularity bias may be low when a platform is in the early stage of growth because a high match rate can help build a platform’s reputation and bring in new users. But, as the platform matures, its focus may shift to maximizing revenues, leading to more popularity bias.

“Our findings suggest that an online dating platform can increase revenue and users’ chances of finding dating partners simultaneously,” explains Musa Eren Celdir, who was a PhD student at Carnegie Mellon when he led the study. “These platforms can use our results to understand user behavior and they can use our model to improve their recommendation systems.”

“Our work contributes to the research on online matching platforms by studying fairness and bias in recommendation systems and by building a new predictive model to estimate users’ decisions,” says Elina H. Hwang, associate professor of information systems at the University of Washington’s Foster School of Business, who also coauthored the study. “Although we focused on a specific dating platform, our model and analysis can be applied to other matching platforms, where the platform makes recommendations to its users and users have different characteristics.”

The researchers suggest that online dating platforms be more transparent with users about how their algorithms work. They also note that more research is needed on how to balance user satisfaction, revenue goals, and ethical algorithm design.

Source: Sheila Davis for Carnegie Mellon University

New natural disaster risk modeling offers a reliable and affordable way for governments to estimate expected damage from river floods that overflow their banks.

In recent months, rivers overflowing their banks have caused property damage and loss of life in France, Italy, Mexico, and South Africa, underscoring the increasing perils of climate change.

To prepare for such river floods, governments deploy mathematical models. However, due to time constraints and lack of data, these models sometimes incorporate “off-the-shelf” damage calculations based on previous unrelated floods.

Unfortunately, these predictions are often inaccurate, leading to inadequate interventions and failing to sufficiently protect property and human life.

The new method not only provides users with step-by-step instructions but also measures and assigns numerical values to the level of uncertainty in individual river flood damage forecasts, giving governments a clearer picture of how reliable their predictions are.

“The bottom line is that accurate predictions are crucial to the safety and well-being of people and property. If a government acts based on inaccurate information, its preparation can be off by orders of magnitude, with very serious results,” says Gonzalo Pita, an associate research scientist in the Whiting School of Engineering’s civil and systems engineering department at Johns Hopkins University.

The study, published in the International Journal of Disaster Risk Reduction, builds upon work that previously appeared in the Journal of Hydrology.

In the new study, Pita first investigated the accuracy of using expert opinion alone to estimate and predict flood damage. He surveyed multiple authorities and simulated thousands of expert surveys in numerous combinations to analyze how the composition of the expert team influences prediction accuracy.

“What I found was a variability in accuracy of between 10% and 46% among experts, which is a wide range,” Pita says. “I also learned that accuracy was enhanced by adding additional expert voices, rather than simply adding more questions to the survey.”

Pita then tackled the issue of “damage functions,” a fundamental component of natural disaster risk simulations. A function refers to the mathematical relationship between two variables—in this case, a depth-damage function describes the correlation between the depth of flood waters and the level of damage it causes, as in “1 foot of flood water in a home causes $10,000 in damage.” Creating these functions accurately is out of the reach of many governments, Pita says.

“It is a very expensive process in terms of money and time, and countries sometimes may not have the expertise, time, or data to develop them within an acceptable timeframe. So with this method, these functions can be built inexpensively but with a useful level of accuracy that governments can use provisionally until they get better data that will enable them to generate more accurate functions.”

The new approach works by helping quantify the uncertainty in experts’ predictions by assigning weights to each expert, resulting in a more detailed analysis of the uncertainties involved. The result is a method that Pita expects to be “very useful” for flood modelers and influencing preparedness policy.

“These types of insights could inform policy directly and indirectly, from enabling smarter zoning laws and budgeting for asset maintenance to designing disaster insurance programs. All of this is to say that better flood damage data and predictions have the potential to have far-reaching benefits,” he says.

Source: Johns Hopkins University

The United States must reduce racial residential segregation if it is to reduce racial disparities in health outcomes, according to a recently published study.

The research on 220 metropolitan areas nationwide between 1980 and 2020 found strong links between trends in racial residential segregation and racial disparities in early death rates from a variety of causes.

The study is the first known to examine the association between changes in racial segregation over time and long-term trends in mortality among non-Hispanic Black and non-Hispanic white people ages 65 or younger.

“This work shows that if we’re able to reduce segregation in communities, we can also expect to reduce health disparities, which is a powerful insight for public health policy,” says Michael Siegel, professor of public health and community medicine at the Tufts University School of Medicine and lead author of the study in the Journal of Racial and Ethnic Health Disparities. “It’s not enough to simply identify disparities; we need to find evidence-based ways to reduce them.”

Drawing on federal data on mortality and demographics in metropolitan statistical areas (MSAs), the study looked at changes in residential segregation between 1980 and 2000 and changes in health outcomes between 2001 and 2018, by which time the researchers hypothesized that measurable differences in mortality would be evident.

The researchers found that both baseline levels of racial residential segregation and ongoing changes in segregation accurately predicted trajectories in the racial disparity in death rates among people younger than age 65 from 12 common causes: breast cancer, colon cancer, lung cancer, prostate cancer, cerebrovascular disease, diabetes, genitourinary disease, HIV, hypertension, respiratory disease, pregnancy, and firearm homicide.

Striking was the fact that, regardless of baseline levels in 1980, increases in levels of segregation between 1980 and 2000 boosted the likelihood that an MSA would be characterized by greater racial health disparities between 2001 and 2018, almost tripling that likelihood in some cases.

Data analysis characterized three groups of MSAs, two of which had lower levels of baseline segregation and showed slight declines over time in Black-to-white mortality disparities. These groups were projected to see the end of disparities by 2034 and 2075, respectively. The third group had the highest levels of baseline segregation and disparities in death rates and their trajectories rose over time, indicating that racial disparities will continue to worsen.

“These data do not support the notion that racism is a thing of the past or that we’re in a post-racial society. In fact, for some people in some communities, things are getting worse,” Siegel says. “Systemic racism, such as restrictive housing covenants and discriminatory ‘redline’ lending policies, created residential segregation, and equally purposeful change will be needed to eliminate segregation and associated health inequities.”

The authors say that the study opens the door for further investigation to identify the best ways to reduce health disparities by combating residential segregation, and they suggest expansion of such research to include other races and ethnicities.

“I’m very excited about the additional research that our study will inspire,” says coauthor Leighla Dergham, a student in the School of Medicine’s physician assistant and master of public health dual-degree program. “By identifying an important entry point for meaningful interventions, our research will potentially have great impact on future public health initiatives and policies to reduce racial health disparities associated with segregation.”

Source: Kim Thurler for Tufts University

Researchers have found a species of ant so rare that only a handful of records exist from across the entire eastern US.

Michelle Kirchner not only found these ants in the Triangle region of North Carolina, she is the first to document an entire colony for scientists, taxonomists, and ant-thusiasts everywhere.

Aphaenogaster mariae Forel are a rare type of spine-wasted ant. Unlike their cousins that nest mostly in the detritus of forest floors, these ants live most of their lives high in tree canopies. This arboreal lifecycle is a fairly common practice for ants in tropical areas, but little was known about the presence or prevalence of arboreal ants in the Triangle, until now.

“I was not expecting to find these ants at all, so I was shocked when I found an entire colony,” says Kirchner, a PhD student in applied ecology and entomology at North Carolina State University and lead author of the paper published in the Proceedings of the Entomological Society of Washington. “With the whole colony, we’re able to document every life stage of this rare ant species, which is a first for science.”

Until now, there were no photographs or documented collections of the males of this species. Likewise, it is unknown how many populations exist, where they are, or what habitats they prefer. However, these new, detailed descriptions of all members of the colony provide some clues.

“The queens of these species are pretty small compared to other ant queens,” says Kirchner. “This small body type is similar to parasitic ant queens since being small makes them more easily mistaken as a fellow worker ant by a colony she is about to infiltrate.”

Around 250 species of ant have been identified in North Carolina, and Kirchner’s rediscovery of this species helps us better understand the unique makeup of North Carolina’s biodiversity.

“We don’t know how important this species is to the ecology of forests in the Triangle,” says Kirchner. “This different surveying effort has changed what we’re finding and our perspective on what’s possible out there. There are still discoveries to be made, even in the Neuse River game lands.”

“This is a great case of a species that’s so rarely encountered that it’s impossible to draw any conclusions about how rare it actually is or isn’t,” says coauthor Elsa Youngsteadt, a professor of applied ecology. Michelle’s observations suggest that these species are fairly localized, but more work needs to be done.”

Matthew Bertone of NC State and Bonnie Blaimer of the Leibniz Institute for Evolution and Biodiversity Science are coauthors of the study.

Source: NC State

Mailing HPV test kits directly to patients significantly increases cervical cancer screening rates, both in populations overdue for screening and those who have previously kept up to date, a new study shows.

Three years ago, the federal government set a series of targets to improve Americans’ overall health. Among the dozens of goals laid out in the plan, called Healthy People 2030, was a significant increase in the proportion of Americans who kept up to date with cervical cancer screening.

That, in turn, would enable more people to catch cervical cancer early, when it’s most treatable.

Home test kits detect the presence of the human papillomavirus (HPV), which causes most cervical cancers. And a negative HPV test counts as a negative cervical cancer screening, allowing most people to avoid a clinic visit altogether.

Currently, more than half of all cervical cancers diagnosed in the United States are in people who are overdue for screening or have never been screened. The team behind this study believes at-home testing can help close the gap.

“This is an alternative, patient-centered way to get people screened for cervical cancer, because patients tend to prefer testing at home and not having to come into the clinic,” says Rachel Winer, a professor of epidemiology at the University of Washington and lead author of the study published in the Journal of the American Medical Association.

“This is a strategy that other countries are already using, and there’s overwhelming evidence that an HPV test on a patient-collected sample is similarly accurate to an HPV test on a sample collected by a clinician. So there’s really no reason why this shouldn’t be available in the US.”

In partnership with Kaiser Permanente Washington, researchers enrolled more than 31,000 female patients between the ages of 30-64 who were either due or overdue for screening, or whose screening history was unknown.

Depending on their screening history, patients were randomly sorted into four groups: One group had HPV test kits mailed directly to participants’ homes, another received information on how to request a test kit, and another received an educational brochure on cervical cancer screening. The fourth group received only a standard reminder that participants were due for screening.

Over the next six months, 62% of people who were due for screening and 36% of people who were overdue were screened for cervical cancer after being directly mailed a kit. Those percentages fell to 48% and 19%, respectively, among patients who received only the educational brochure. Sending information on requesting a kit minimally increased screening.

The results indicate that health care systems should prioritize mailing HPV test kits directly to patients to maximize cervical cancer screening participation, Winer says.

“We just think this should be an option for all patients,” Winer says. “It’s convenient, preferred by most patients, and an accurate way to screen for cervical cancer. So why not have it as an option?”

This study builds on previous research conducted by Winer and her colleagues, which found that mailing HPV test kits to under–screened patients increased screening rates, though most people remained untested. That study took place before the cervical cancer screening guidelines were updated to include HPV testing alone, so the test kit did not count as a regular screen.

Self-testing is already an option for other routine screenings, most notably for colorectal cancer. The most recent guidelines encourage home test kits as a primary screening option, suggesting that annual stool samples may be taken in place of a routine colonoscopy, which many patients find uncomfortable. Home test kits are now so commonplace that Saturday Night Live has parodied the ubiquitous TV commercials for one prominent manufacturer.

Colorectal screening rates have risen steadily in recent years.

There are still significant barriers to overcome before HPV self-sampling can become widely available, Winer says. Chief among them is approval by the Food and Drug Administration, which is expected to come in the next few months.

Once HPV self-sampling receives FDA approval for use as a cervical cancer screening tool, health care systems that want to implement self-screening need to procure test kits, review their policies and educate both patients and providers. Algorithms used to track patients’ care have to be updated. Health centers serving low-income and marginalized communities may not have the staff or financial resources to distribute test kits. Patients without a primary care physician may slip through the cracks.

“HPV self-sampling is a tool certainly designed to increase access and reduce disparities,” Winer says. “But sometimes when a new intervention is introduced, it can further widen disparities if there isn’t attention taken to how to best implement it, or how to specifically make sure that it reaches people who need it the most.”

Beverly Green, a senior investigator at KPWHRI, is the study’s co-lead author. Additional coauthors are from the University of Washington; the University of Chicago; Kaiser Permanente Center for Health Research; UnitedHealthcare; and GRAIL LLC in Menlo Park, California.

The National Cancer Institute funded the work.

Source: University of Washington

Headless animals called brittle stars have no brains at all and still manage to learn through experience, new research reveals.

Relatives of starfish, brittle stars spend most of their time hiding under rocks and crevices in the ocean or burrowing in the sand.

These shy marine creatures have no brain to speak of—just nerve cords running down each of their five wiggly arms, which join to form a nerve ring near their mouth.

“There’s no processing center,” says lead author Julia Notar, who did the research as part of her biology PhD in the lab of Sönke Johnsen, a professor at Duke University.

“Each of the nerve cords can act independently,” Notar says. “It’s like instead of a boss, there’s a committee.”

In the case of brittle stars, that seems to be enough to learn by association, Notar, Johnsen, and former Duke undergraduate Madeline Go report in the journal Behavioral Ecology and Sociobiology.

This type of learning involves associating different stimuli via a process called classical conditioning. A famous example is Pavlov’s dog experiments, which showed that dogs repeatedly fed at the ringing of a bell would eventually start drooling at the mere sound of a bell, even when no food was around.

Humans do this all the time. If you hear the “ding” of a smartphone over and over again with each new alert, eventually the sound starts to have a special meaning. Just hearing someone’s phone ping or buzz with the same chime as yours is enough to make you reflexively reach for your own phone in anticipation of the next text, email, or Instagram post.

Classical conditioning has been demonstrated in a handful of previous studies in starfish. But most echinoderms—a group of some 7,000 species that includes brittle stars and similarly brainless starfish, sea urchins, and sea cucumbers—have not been tested.

To find out if brittle stars are capable of learning, the researchers put 16 black brittle stars (Ophiocoma echinata) in individual water tanks and used a video camera to record their behavior.

The researchers trained half the brittle stars by dimming the lights for 30 minutes whenever the animals were fed. Every time the lights went out, the researchers would put a morsel of shrimp—”which they love”—in the tanks, placed just out of reach.

The other half got just as much shrimp and also experienced a 30-minute dark period, but never at the same time—the animals were fed under lit conditions.

Whether it was light or dark, the animals spent most of their time hiding behind the filters in their tanks; only coming out at mealtime. But only the trained brittle stars learned to associate darkness with food.

Early in the 10-month-long experiment, the animals stayed hidden when the lights went out. But over time, the animals made such a connection between the darkness and mealtime that they reacted as if food was on its way and crept out of hiding whenever the lights went out, even before any food was put in the tanks.

These brittle stars had learned a new association: lights out meant that food was likely to show up. They didn’t need to smell or taste the shrimp to react. Just sensing the lights go dim was enough to make them come when called for dinner.

They still remembered the lesson even after a 13-day “break” without training, i.e., dimming the lights over and over again without feeding them.

The results are “exciting” because “classical conditioning hasn’t really been shown definitively in this group of animals before,” Notar says.

“Knowing that brittle stars can learn means they’re not just robotic scavengers like little Roombas cleaning up the ocean floor. They’re potentially able to expect and avoid predators or anticipate food because they’re learning about their environment.”

As a next step, Notar hopes to start to tease apart how they manage to learn and remember using a nervous system that is so different from our own.

“People ask me all the time, ‘how do they do it?’” Notar says. “We don’t know yet. But I hope to have more answers in a few years.”

The US Department of Department of Defense through the National Defense Science & Engineering Graduate Fellowship Program, the Duke Nicholas School Rachel Carson Scholars program, and the Duke department of biology funded the work.

Source: Duke University

A new discovery may lead to medical advances in bio-implants, wearable sensors, and more, according to a new study.

How to create strong, yet quick-release connections between living and non-living tissue continues to puzzle bioengineers who aim to create materials that bond together for advanced biomedical applications.

Looking to nature for inspiration, researchers zeroed in on the marine mussel byssus, a fibrous holdfast, which these bivalve mollusks use to anchor themselves in seashore habitats.

The byssus attaches to rocky surfaces using an underwater glue, but the other end (the byssus stem root) is firmly anchored within the mussel’s soft living tissue. This area of contact between the living tissue and the non-living byssus stem root is known as a biointerface, and is the focus of the new study published in Science.

“Up to this point, it was baffling how the byssus stem root biointerface could be strong enough to resist constant crashing waves but also be suddenly released by the mussel upon demand,” says Matthew Harrington, professor of chemistry at McGill University. “It seemed as if the mussel could somehow control its strength.”

Following a cross-disciplinary investigation, the team found that the stem root separates into approximately 40-50 sheets known as lamellae that interlock with the living tissue, creating an incredibly strong interface much like interleaving two phone books together.

“The biggest surprise is how this strength can be lowered through the beating movements of billions of tiny hair-like cilia on the surface of the living tissue. Cilia movement is under the control of the neurotransmitters serotonin and dopamine, enabling the quick release of the whole stem root on demand.” says Harrington.

This finding is particularly relevant for biomedical engineers and materials scientists as they look towards the future of bio-implants, wearable sensors, brain-computer interface design, and more.

“The stem root biointerface is unlike anything seen in human-made materials and could offer important inspiration for the next generation of biointerfaces,” says Harrington. “Since further medical advances will depend on novel biointerface design, these findings could have impact on human health in the future.”

Source: McGill University

Quinoa and other extremely resilient plants are covered with strange balloon-like bladders that were long believed to protect them from drought and salt. New findings say otherwise.

These so-called bladder cells serve a completely different though important function. The finding makes the breeding of more resistant quinoa plants more, which could lead to wider cultivation of the sustainable crop worldwide.

“Quinoa has been touted as a future-proof crop because it is rich in proteins and highly tolerant of drought and salt, and thus climate change. Scientists believed that the secret to quinoa’s tolerance was in the many epidermal bladder cells on the surface of the plant. Until now, it was assumed that they served as a kind of salt dump and to store water. But they don’t, and we have strong evidence for it,” says professor Michael Palmgren of the department of plant and environmental sciences at the University of Copenhagen.

Epidermal bladder cells are fluid-filled hair structures on the leaves, stems, and surfaces of a variety of plants. A few plants, including quinoa, are often completely covered with them.

Bladder cells are actually a form of trichomes. Trichomes are hairlike structures that most plants have. As a rule, trichomes look completely different and appear more like the hairs on the leaves of stinging nettles.

Mutants without bladder cells

Three years ago, a research group led by PhD student Max Moog and his supervisor, Palmgren, began studying the epidermal bladder cells of quinoa plants in ways that had never been used before. The hope was to understand the plant’s mechanisms for making it resilient to salt and drought.

To this end, the researchers cultivated mutant plants without bladder cells to compare their reactions to salt and drought with those of wild quinoa plants covered with bladder cells.

To their surprise, the researchers discovered that bladder cells have no positive influence on the plant’s ability to tolerate salt and drought. On the contrary, they seem to weaken tolerance. Instead, bladder cells serve as a barrier against pests and disease.

“Whether we poured salt water on the mutant plants without bladder cells or exposed them to drought, they performed brilliantly and against expectations. So, something was wrong. On the other hand, we could see that they were heavily infested with small insects—unlike the plants covered with bladder cells. That’s when I realized that bladder cells must have a completely different function,” says Moog, now a postdoc at the department of plant and environmental sciences and first author of the study in the journal Current Biology.

When the researchers analyzed the contents of the bladder cells, they didn’t find salt as expected—despite having added extra salt to the plant. Instead, they found compounds that repel intruders.

“We discovered that bladder cells act as both a physical and chemical barrier against hungry pests. When tiny insects and mites trudge around on a plant covered with bladder cells, they are simply unable to get to the juicy green shoots that they’re most interested in. And as soon as they try to gnaw their way through the bladder cells, they find that the contents are toxic to them,” says Palmgren.

Among other things, the epidermal bladder cells of quinoa contain oxalic acid, a compound also found in rhubarb, which acts as a deadly poison on pests.

The experiments also demonstrated that the bladder cells even protect quinoa against one of the most common bacterial diseases in plants, Pseudomonas syringae. This probably happens because the bladder cells partially cover the stomata on the plant’s leaves, a point of entry for many bacterial invaders.

“Our hypothesis is that these bladder cells also protect against other plant diseases like downy mildew, a fungal disease which severely limits quinoa yields,” says Moog.

Is super quinoa to come?

There are thousands of varieties of the South American crop, and the density of bladder cells on the plant’s surface varies from variety to variety. But there is much to suggest that density determines how effective a safeguard the bladder cells are.

“Quinoa varieties with a higher density of bladder cells are most likely more robust against pests and diseases. On the other hand, they may be slightly less tolerant of salt and drought. And vice versa. These variations don’t change the fact that quinoa is generally very resistant to salt and drought. But the explanation must be found somewhere other than in the bladder cells,” says Moog, continuing:

“Due to efforts to expand quinoa cultivation around the world, the new knowledge can be used to adapt the crop to various regional conditions. For example, southern Europe has very dry conditions, while pests are a bigger problem than drought in northern Europe. Here in northern Europe, it would make sense to focus on quinoa varieties that are densely covered with bladder cells.”

According to Palmgren, the new results provide a concrete recipe for how to breed “super-quinoa” relatively easily:

“Thus far, these bladder cells have been ignored in the breeding of quinoa. If you want a crop that is extra resistant to pests and diseases, but is still tolerant of salt and drought, one can opt to breed varieties that are densely covered with bladder cells. So, we may now have a tool that allows us to simply cross-breed our way to an extra tolerant ‘super-quinoa,’” says Palmgren.

The research results add a new dimension to our knowledge about quinoa. Until now, very little was known about how the plant defends itself against attacks from hostile organisms.

“Now we know, quinoa isn’t just tolerant of non-biological stressors like drought and salt, but also of biological influences such as pests and pathogenic bacteria. And at the same time, we’ve found the secret of these odd-looking bladder cells. This research is an example of how what’s established doesn’t always turn out to be what’s true,” says Palmgren.

Coauthors of the study are the University of Copenhagen, the University of Amsterdam, Ishikawa Prefectural University, and the University of Nevada.

The research has funding from the Novo Nordisk Foundation and the University of Copenhagen, as well as the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie Fellowship Programme.

Source: University of Copenhagen

Using 700 years’ worth of wave data from more than a billion waves, scientists have used artificial intelligence to find a formula for how to predict the occurrence of rogue waves.

Long considered myth, freakishly large rogue waves are very real and can split apart ships and even damage oil rigs. The new knowledge can make shipping safer.

Stories about monster waves, called rogue waves, have been the lore of sailors for centuries. When a 26-meter (85-foot) rogue wave slammed into the Norwegian oil platform Draupner in 1995, digital instruments were there to capture and measure the North Sea monster. It was the first time that a rogue wave had been measured, and the event provided scientific evidence that abnormal ocean waves really do exist.

Researchers from the University of Copenhagen’s Niels Bohr Institute have used AI methods to discover a mathematical model that provides a recipe for how—and not least when—rogue waves can occur.

With the help of enormous amounts of big data about ocean movements, researchers can predict the likelihood of being struck by a monster wave at sea at any given time.

“Basically, it is just very bad luck when one of these giant waves hits. They are caused by a combination of many factors that, until now, have not been combined into a single risk estimate. In the study, we mapped the causal variables that create rogue waves and used artificial intelligence to gather them in a model which can calculate the probability of rogue wave formation,” says Dion Häfner, a former PhD student at the Niels Bohr Institute and first author of a paper on the work in the Proceedings of the National Academy of Sciences.

Rogue wave data

In their model, the researchers combined available data on ocean movements and the sea state, as well as water depths and bathymetric information. Most importantly, wave data was collected from buoys in 158 different locations around US coasts and overseas territories that collect data 24 hours a day. When combined, this data—from more than a billion waves—contains 700 years’ worth of wave height and sea state information.

The researchers analyzed the many types of data to find the causes of rogue waves, defined as being waves that are at least twice as high as the surrounding waves—including extreme rogue waves that can be over 20 meters (65 feet) high. With machine learning, they transformed it all into an algorithm that was then applied to their dataset.

“Our analysis demonstrates that abnormal waves occur all the time. In fact, we registered 100,000 waves in our dataset that can be defined as rogue waves. This is equivalent around one monster wave occurring every day at any random location in the ocean. However, they aren’t all monster waves of extreme size,” explains Johannes Gemmrich, the study’s second author.

The new study also breaks with the common perception of what causes rogue waves. Until now, it was believed that the most common cause of a rogue wave was when one wave briefly combined with another and stole its energy, causing one big wave to move on.

However, the researchers establish that the most dominant factor in the materialization of these freak waves is what is known as “linear superposition.” The phenomenon, known about since the 1700s, occurs when two wave systems cross over each other and reinforce one another for a brief period.

“If two wave systems meet at sea in a way that increases the chance to generate high crests followed by deep troughs, the risk of extremely large waves arises. This is knowledge that has been around for 300 years and which we are now supporting with data,” says Häfner.

Cargo ships at sea

The researchers’ algorithm is good news for the shipping industry, which at any given time has roughly 50,000 cargo ships sailing around the planet. Indeed, with the help of the algorithm, it will be possible to predict when this “perfect” combination of factors is present to elevate the risk of a monster wave that could pose a danger for anyone at sea.

“As shipping companies plan their routes well in advance, they can use our algorithm to get a risk assessment of whether there is a chance of encountering dangerous rogue waves along the way. Based on this, they can choose alternative routes,” says Häfner.

Both the algorithm and research are publicly available, as are the weather and wave data that the researchers deployed. Therefore, Häfner says that interested parties, such as public authorities and weather services, can easily begin calculating the probability of rogue waves. And unlike many other models created using artificial intelligence, all the intermediate calculations in the researchers’ algorithm are transparent.

“AI and machine learning are typically black boxes that don’t increase human understanding. But in this study, Dion used AI methods to transform an enormous database of wave observations into a new equation for the probability of rogue waves, which can be easily understood by people and related to the laws of physics,” concludes professor Markus Jochum, Dion’s thesis supervisor and coauthor.

Source: University of Copenhagen