Taking a bite out of tooth evolution: Frogs have lost teeth more than 20 times

FLORIDA MUSEUM OF NATURAL HISTORY

Research News

IMAGE: SOME FROG SPECIES HAVE TEETH WHILE OTHERS ARE TOOTHLESS. STILL OTHERS HAVE A COMBINATION OF TRUE TEETH AND TOOTHLIKE STRUCTURES. THE SOLOMON ISLAND LEAF FROG, CORNUFER GUENTHERI, HAS TRUE TEETH... view more 

CREDIT: DANIEL PALUH/FLORIDA MUSEUM OF NATURAL HISTORY

GAINESVILLE, Fla. --- Scientists have long known that frogs are oddballs when it comes to teeth. Some have tiny teeth on their upper jaws and the roof of their mouths while others sport fanglike structures. Some species are completely toothless. And only one frog, out of the more-than 7,000 species, has true teeth on both upper and lower jaws.

Now, the first comprehensive study of tooth evolution in frogs is bringing the group's dental history into focus. Florida Museum of Natural History researchers analyzed CT scans of nearly every living amphibian genus to reveal that frogs have lost teeth over 20 times during their evolution, more than any other vertebrate group. Some frog species may have even re-evolved teeth after losing them millions of years before.

Researchers also found a correlation between the absence of teeth in frogs and a specialized diet on small insects, such as ants and termites. Their analysis of frogs' amphibian relatives, the salamanders and obscure wormlike animals known as caecilians, showed these groups retained teeth on both upper and lower jaws throughout their evolutionary history.

"Through this study, we have really been able to show that tooth loss in vertebrates is largely a story about frogs, with over 20 independent losses," said lead study author Daniel Paluh, a Ph.D. candidate in the University of Florida's department of biology. "Only eight other groups of living vertebrates, including seahorses, turtles, birds and a few mammals, have also evolved toothlessness."

Teeth first evolved more than 400 million years ago, quickly conferring a competitive advantage to animals that had them and leading to the diversification of sharks, bony fish and ultimately the vertebrates that first roamed onto land.

Throughout their long history, teeth have been an important component of vertebrate evolution, yet some groups have done equally well without them. Birds lost their teeth around 100 million years ago with the advent of the beak, and both the largest known vertebrate, the blue whale, and the smallest, a frog from New Guinea, are entirely toothless.

Few researchers have focused on studying frog teeth, however, for the simple reason that they're incredibly small.

"If you open a frog's mouth, chances are you will not see teeth even if they have them, because they're usually less than a millimeter long," or smaller than the tip of a pencil, Paluh said.

That hasn't stopped some people from trying. In his study of the relationships between frog species, the famous 19th-century paleontologist Edward Cope lumped all toothless frogs into the same group, which he called Bufoniformia.

Researchers using modern genetic techniques have since shown that species in Bufoniformia aren't actually closely related, suggesting that the loss of teeth occurred more than once in frog evolution. But there the story stalled.

In the past, accurately determining which frogs had teeth would have required laborious work that irrevocably damaged or destroyed portions of preserved specimens. Frogs are also a highly diverse group, making a comprehensive assessment of their teeth a difficult task.

But Paluh and his colleagues had one major advantage: The Florida Museum leads a massive multi-institutional effort to CT scan 20,000 vertebrate specimens, giving researchers the ability to study animals in ways not previously possible.

The project, called oVert, allows anyone with an Internet connection to access 3D models derived from the scans, which depict distinct features of an organism, including bones, vasculature, internal organs, muscle tissue - and teeth. For Paluh, it meant he could virtually peer into the gape of a frog.

Working remotely during COVID-19 lockdowns, Paluh and fellow members of the museum's Blackburn Lab used oVert scans to carry out the study. To get the clearest picture of changes in teeth over time, the researchers included representatives of all amphibian groups. They analyzed patterns of tooth loss through time using a previously published map of evolutionary relationships between amphibians based on genetic data.

The study provides a powerful example of the research that can be accomplished with open-access data, said David Blackburn, Florida Museum curator of herpetology, Paluh's adviser and senior author of the study.

"We effectively crowdsourced the data collection across our lab, including people that were not in the U.S. at that time," Blackburn said.

Their results showed that far from losing teeth once during their evolution, as suggested by the now-debunked idea of the Bufoniformia, frogs have undergone "rampant tooth loss," Paluh said, with toothlessness popping up in groups as distantly related as toads and poison dart frogs.

The team also noted a tight correlation between the presence or absence of teeth in frogs and their eating habits. While dietary information is scant for many species of frogs, the researchers uncovered a connection between a diet of tiny insects and a lack of teeth.

"Having those teeth on the jaw to capture and hold on to prey becomes less important because they're eating really small invertebrates that they can just bring into their mouth with their highly modified tongue," said Paluh. "That seems to relax the selective pressures that are maintaining teeth."

Some species of poison dart frogs, for example, have evolved to feed mostly on ants and mites that produce toxic compounds, using their sticky, projectile tongues to scoop up their prey and swallow it whole. The frogs are able to store the toxins from their food source and repurpose them for their own use, secreting the compounds through their skin to ward off predators. And the turtle frog, a toothless burrowing species in Australia, tunnels through the maze of underground passages inside termite nests, hunting the insects that constructed them.

Teeth seem to be superfluous for mammals that feed on ants and termites as well. Pangolins and anteaters, which have highly specialized tongues for probing ant and termite nests, are both toothless.

Many questions remain about frogs' tooth biology, including how the genes that regulate their tooth production turn on and off. It's also unclear whether the serrated toothlike structures in frogs that regained these features are actually real teeth, Paluh said. To determine that, scientists will need to take a more in-depth look at these structures, looking for the presence of enamel and other key defining features.

Innovative techniques, such as those used in the oVert project, are beginning to underscore knowledge gaps and limitations like these, but they also open up the field to new discoveries, Blackburn said.

"We now have lots of new questions in my lab inspired by the surprising things turning up from 3D imaging from the oVert project, and those will lead us both back into museum collections and to the field to see what these animals are doing in the wild."

CAPTION

Researchers found a high correlation between a diet of small insects and a lack of teeth in frogs. The strawberry poison frog, Oophaga pumilio, is a toothless species that eats ants and termites.

CREDIT

Daniel Paluh/Florida Museum of Natural History

Other study co-authors are the Florida Museum's Karina Riddell, Maggie Hantak, Gregory Jongsma, Rachel Keeffe, Stuart Nielsen, María Camila Vallejo-Pareja and Edward Stanley, Catherine Early of the Florida Museum and the Science Museum of Minnesota and Fernanda Magalhães Silva of the Florida Museum and the Federal University of Pará.

Blackburn noted that Riddell, who recently graduated from UF with a bachelor's degree from the College of Health and Human Performance, played a key role in collecting data for the project.

 

Study: Parler provided echo chamber for vaccine misinformation, conspiracy theories

Analysis shows posters followed themes; can help guide future health communications

UNIVERSITY OF KANSAS

Research News

 

LAWRENCE -- In the early days of COVID-19 vaccine development, a new social media platform provided a place for like-minded people to discuss vaccines, share misinformation and speculate about the motivations for its development. A new study from the University of Kansas shows people flocked to Parler to discuss the vaccines in an echo chamber-type environment, and those conversations can shed light about how to communicate about vaccine efficacy during health crises.

COVID-19 vaccine vial and syringe photo from the U.S. Census Bureau.In the runup to the 2020 election, then-president Donald Trump claimed a COVID-19 vaccine could be ready before people went to the polls. About that time, millions were flocking to Parler, a new social media platform that promised a free speech environment via unregulated posts. A trio of KU doctoral students in journalism & mass communications analyzed a sample of 400 posts on the platform between November 2020 and January 2021 about the vaccines. Results showed people followed messages of conservative political leaders, shared misinformation and reinforced messages shedding doubt on vaccine efficacy.

"Around October last year, we were hearing a lot of buzz around a new social media platform, Parler, not just in the political field, but in the health field as well," said Annalise Baines, the study's lead author. "We wanted to understand more about what was being said about COVID-19 vaccines specifically, as we noticed a shift in the conversation from developing vaccines to distrusting science around the efficacy of vaccines."

The study, co-written by Baines, Muhammad Ittefaq and Mauryne Abwao, was published in the journal Vaccines.

A thematic analysis of the posts, known as "parleys," showed users discussing the vaccines in five distinct themes:

• Reasons to refuse the vaccine
• Side effects
• Population control through the vaccines
• Children getting vaccinated without parental consent
• Comparison of other health issues with COVID-19

Previous research has extensively examined communication via social media, but Parler, a relatively new platform that has undergone controversy and was deplatformed for several weeks following the Jan. 6 insurrection at the U.S. Capitol, has not been studied widely. The authors, who study environmental, health communications, and new social and digital media topics, analyzed how people discussed vaccines, an important public health issue, among like-minded individuals. While the research didn't compare users' political leanings, the platform was widely popular with conservative users and was touted as an alternative to sites such as Twitter or Facebook, which they accused of anti-conservative bias.

"If you live in a bubble in which you only hear from people who share the same views as you and information that supports that, that tends to reinforce what you already believe in. It's also about people you trust. We didn't have demographic information on users, but we did find echo chambers existed there, and people even used the hashtag #echo," Ittefaq said.

Among the five key themes, users frequently used hashtags to further spread their content, such as #nocovidvaccine, #novaccine, #wedonotconsent, #vaxaware, #wakeupworld. Users also shared polls showing people in the U.S. and Europe didn't want a vaccine, or they shared dubiously sourced news stories about nurses who suffered from Bell's palsy after getting the dose. This finding also appeared in the second most frequent theme regarding side effects. Users shared posts about people dying after receiving the vaccine or who had cognitive effects or were hospitalized.

"Some of the reasons for vaccine hesitancy are deemed legit, and the major concerns may have been a result of people being skeptical of the side effects," Abwao said. "Currently, we have experienced cases where some vaccines have been discontinued; however, this should not deter people from getting vaccinated."

One of the most popular conspiracy theories shared was that vaccines were being developed as a means for government or a new world order to control the population, according to the KU researchers. Frequent conspiracies involved the use of microchips via the vaccine or an enzyme that would control the population, the study found. People often included links, videos and images with such parleys, though when sources were included they were from unverified sites or contained videos that were purported to be leaked from the government. In other themes, users shared posts claiming schools would vaccinate children without parents' consent or cast doubt on the pandemic's severity, comparing it to other health issues such as the flu, or citing abortion statistics to claim it was not as deadly as commonly reported. Common hashtags in those themes included #scamdemic, #plandemic, #idonotconsent, #covidhoax and #nocovidvaccine.

The findings illustrate several key points in health communications and social media use, the authors said. People listen to the messages of elected officials and will adhere to them, such as Trump calling the virus a hoax or U.S. Sen. Ted Cruz's endorsement of Parler as a place to share opinions on current issues. The views shared by people can not only spread misinformation but can also be informative for policymakers and public health officials to counter anti-vaccination rhetoric, the KU researchers said. On the Parler platform anyone can post claims online without going through verification steps and share that information with others. This can be dangerous, especially for those who might be more vulnerable and not be able to identify misinformation, Baines said.

Public health officials have a difficult job in which they are trained to perform science and share findings, not to combat misinformation, Ittefaq said. But, if they are able to use credible information through stories of individuals and trusted experts, they can help disseminate credible information on health crises to the public. Failing to do so can have negative ramifications in future public health crises, he added. The analysis shows people listen to those similar to themselves, and that if public health officials can share valid information with people who can share it with their peers, they will have greater success in situations such as the COVID-19 pandemic, in which people continue to seek valid information about the vaccines.

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Chip inserted under the skin may better identify patients at risk of recurrent stroke

STROKE AF trial results indicate that an inserted chip can improve detection of irregular heart rate

MASSACHUSETTS GENERAL HOSPITAL

Research News

BOSTON - For patients who have experienced certain common types of stroke, a small chip inserted under the skin may help physicians predict their likelihood of experiencing a second stroke, and therefore their likelihood of benefiting from preventive therapy. The findings come from a recent clinical trial published in the Journal of the American Medical Association and led by investigators at Massachusetts General Hospital (MGH) and Northwestern University Feinberg School of Medicine.

Each year, approximately 800,000 strokes occur in the United States, and as many as one-fourth occur in people who experienced a previous stroke. Investigators have been searching for ways to identify patients who are likely to experience a recurrent stroke, as these individuals could be candidates for taking certain medications such as blood thinners. One group of patients who face an elevated risk of recurrent strokes are those with atrial fibrillation--an irregular and often rapid heart rate--that often goes undetected and untreated. (Irregular heartbeats can allow blood to pool in the heart, which can cause clots to form and travel to the brain.)

Recent research has shown that a small chip inserted under the skin can monitor the heart rate and rhythm, and help physicians detect atrial fibrillation in patients who previously experienced what's called a cryptogenic stroke, one with no identified cause despite thorough patient testing. Now investigators have tested the chip--less than 1¾? long and 1/6? thick and called an insertable cardiac monitor--in patients who experienced a stroke caused by narrowing of a large artery like the carotid artery, or blockage of a small artery deep in the brain where atrial fibrillation would be unexpected.

In the Stroke of Known Cause and Underlying Atrial Fibrillation (STROKE AF) trial, 492 patients were randomized and completed 12 months of follow-up after receiving either an insertable cardiac monitor within 10 days of an initial stroke or usual care consisting of external cardiac monitoring through electrocardiograms or other tracking methods.?

The chip detected atrial fibrillation in 12.1% of patients, compared with 1.8% detected through usual care. The team noted that the episodes of atrial fibrillation were not brief, with most lasting at least one hour. Most stroke experts would recommend that patients with this degree of atrial fibrillation start taking blood thinners to prevent a future stroke.

"We found that a significant minority of patients with stroke not thought to be related to atrial fibrillation actually have atrial fibrillation, but we can only find it with an implantable monitor," says lead author Richard A. Bernstein, MD, PhD, a professor of Neurology at Northwestern University Feinberg School of Medicine.

Adds senior author Lee H. Schwamm, MD, C. Miller Fisher Chair of Vascular Neurology at MGH: "Based on the study findings, we believe that patients with stroke who are similar to those in the STROKE AF Trial should now undergo long-term cardiac monitoring with an insertable cardiac monitor to identify unsuspected atrial fibrillation."

Schwamm notes that for every eight patients monitored, clinicians could expect to find atrial fibrillation in one of them in the first year. "This could dramatically change the treatment recommendations by their doctor," he says.

Next steps in this research include identifying patient factors that predict the development of atrial fibrillation and the duration and extent of the arrhythmia. Additional studies are being explored to further understand the association of silent atrial fibrillation and recurrent stroke of all types.

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Schwamm is professor of Neurology at Harvard Medical School and vice president of Virtual Care at Mass General Brigham. Co-authors are Hooman Kamel, MD, of Weill Cornell Medicine in New York City; Christopher B. Granger, MD, and Jonathan P. Piccini, MD, of Duke University Medical Center; Pramod P. Sethi, MD, of Cone Health Stroke Center and Guilford Neurologic Research Associates in Greensboro, North Carolina; Jeffrey M. Katz, MD, of North Shore University Hospital in Manhasset, New York; and Carola Alfaro Vives, MS, Paul D. Ziegler, MS, and Noreli C. Franco, PhD, of Medtronic.

This study was supported by Medtronic.

About the Massachusetts General Hospital

Massachusetts General Hospital, founded in 1811, is the original and largest teaching hospital of Harvard Medical School. The Mass General Research Institute conducts the largest hospital-based research program in the nation, with annual research operations of more than $1 billion and comprises more than 9,500 researchers working across more than 30 institutes, centers and departments. In August 2020, Mass General was named #6 in the U.S. News & World Report list of "America's Best Hospitals."

Better popping potential for popcorn

AMERICAN SOCIETY OF AGRONOMY

Research News

 

IMAGE: THE RESEARCH TEAM OBSERVED 49 DIFFERENT VARIETIES OF POPCORN INCLUDING WHITE POPCORN, YELLOW POPCORN, PURPLE POPCORN, AND BLACK POPCORN TO DETERMINE ECONOMICAL WAYS TO CREATE HIGH-QUALITY POPCORN. view more 

CREDIT: MARIA FERNANDA MAIOLI

Popcorn. What would movies and sporting events without this salty, buttery snack? America's love for this snack goes beyond these events. We consume 15 billion quarts of popped popcorn each year.

When it comes to popcorn, consumers want a seed-to-snack treat that leaves more snacks than seeds when popped. This means when they pop the corn, there shouldn't be many unpopped kernels left in the bowl.

Maria Fernanda Maioli set out to determine the properties affecting popping expansion in popcorn. The team's research was recently published in Agronomy Journal, a publication of the American Society of Agronomy.

"The way kernels expand is a basic, yet very important characteristic of popcorn," says Fernanda Maioli. This is referred to as "expansion ratio."

"Very hard grains burst when heated. This expansion multiplies the initial volume of the grains by more than 40 times. In the case of popcorn, it produces a unique and tasty food."

The major factors that influence popcorn quality are kernel moisture, expansion ratios, and popping ratios. Higher quality popcorn is associated with kernels that expand more. This popped corn has a better texture and softness.

CAPTION

Yellow popcorn is the type most people are familiar with. This is the type commonly used by movie theaters.

CREDIT

Maria Fernanda Maioli

There have been several past studies on the ways popcorn kernel expand. These studies report that popping expansion has a strong association with higher starch content in kernels.

Previous research also shows that popcorn varieties with a thicker protective outer seed coating - have a greater expansion ratio.

Popping ability is also affected by how well the starchy substance inside kernels transfer heat during the popping process. Fernanda Maioli and her team's study measured this performance, which makes this research unique.

"We observed how this heat transfer inside the popcorn kernel relates to the expansion ratio," she adds. "It allowed us to understand how other characteristics may also relate to expansion."

"The purpose of our study was to identify popcorn characteristics related to expansion," says Fernanda Maioli. "This will help us efficiently identify popcorn varieties with good agronomic characteristics as well as good popping quality."

The team evaluated 49 types of popcorn for different traits. The traits included grain yield, kernel length, popping expansion, kernel and protective layer thickness, heat transfer ability, and the amount of protein in kernels.

Then the researchers studied the influence of those characteristics on the popping expansion.

"Our results showed that the thickness of the kernel's outer layer is a key trait for selecting popcorn with greater popping expansion," says Fernanda Maioli.

Understanding which popcorn traits are related to the expansion capacity will help future researchers identify and breed high quality popcorn. Researchers will not need to spend time and money to look at other unrelated characteristics.

The team hopes they can identify relationships between other key traits. Future research will continue to improve the tasty, buttery snack.

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Maria Fernanda Maioli is a researcher at the State University of Maringá in Brazil.

CAPTION

Purple popcorn kernels have a gorgeous hue and contain more antioxidants than traditional yellow kernels.

CREDIT

Maria Fernanda Maioli

How AI could alert firefighters of imminent danger

NATIONAL INSTITUTE OF STANDARDS AND TECHNOLOGY (NIST)

Research News

 

IMAGE: NIST FIREFIGHTERS DOUSE FLAMES BURSTING FROM A BUILDING AS A FLASHOVER OCCURS DURING AN EXPERIMENT. view more 

CREDIT: NIST

Firefighting is a race against time. Exactly how much time? For firefighters, that part is often unclear. Building fires can turn from bad to deadly in an instant, and the warning signs are frequently difficult to discern amid the mayhem of an inferno.

Seeking to remove this major blind spot, researchers at the National Institute of Standards and Technology (NIST) have developed P-Flash, or the Prediction Model for Flashover. The artificial-intelligence-powered tool was designed to predict and warn of a deadly phenomenon in burning buildings known as flashover, when flammable materials in a room ignite almost simultaneously, producing a blaze only limited in size by available oxygen. The tool's predictions are based on temperature data from a building's heat detectors, and, remarkably, it is designed to operate even after heat detectors begin to fail, making do with the remaining devices.

The team tested P-Flash's ability to predict imminent flashovers in over a thousand simulated fires and more than a dozen real-world fires. Research, just published in the Proceedings of the AAAI Conference on Artificial Intelligence, suggests the model shows promise in anticipating simulated flashovers and shows how real-world data helped the researchers identify an unmodeled physical phenomenon that if addressed could improve the tool's forecasting in actual fires. With further development, P-Flash could enhance the ability of firefighters to hone their real-time tactics, helping them save building occupants as well as themselves.

Flashovers are so dangerous in part because it's challenging to see them coming. There are indicators to watch, such as increasingly intense heat or flames rolling across the ceiling. However, these signs can be easy to miss in many situations, such as when a firefighter is searching for trapped victims with heavy equipment in tow and smoke obscuring the view. And from the outside, as firefighters approach a scene, the conditions inside are even less clear.

"I don't think the fire service has many tools technology-wise that predict flashover at the scene," said NIST researcher Christopher Brown, who also serves as a volunteer firefighter. "Our biggest tool is just observation, and that can be very deceiving. Things look one way on the outside, and when you get inside, it could be quite different."

Computer models that predict flashover based on temperature are not entirely new, but until now, they have relied on constant streams of temperature data, which are obtainable in a lab but not guaranteed during a real fire.

Heat detectors, which are commonly installed in commercial buildings and can be used in homes alongside smoke alarms, are for the most part expected to operate only at temperatures up to 150 degrees Celsius (302 degrees Fahrenheit), far below the 600 degrees Celsius (1,100 degrees Fahrenheit) at which a flashover typically begins to occur. To bridge the gap created by lost data, NIST researchers applied a form of artificial intelligence known as machine learning.

"You lose the data, but you've got the trend up to where the heat detector fails, and you've got other detectors. With machine learning, you could use that data as a jumping-off point to extrapolate whether flashover is going to occur or already occurred," said NIST chemical engineer Thomas Cleary, a co-author of the study.

Machine-learning algorithms uncover patterns in large datasets and build models based on their findings. These models can be useful for predicting certain outcomes, such as how much time will pass before a room is engulfed in flames.

To build P-Flash, the authors fed their algorithm temperature data from heat detectors in a burning three-bedroom, one-story ranch-style home -- the most common type of home in a majority of states. This building was of a digital rather than brick-and-mortar variety, however.

Because machine learning algorithms require great quantities of data, and conducting hundreds of large-scale fire tests was not feasible, the team burned this virtual building repeatedly using NIST's Consolidated Model of Fire and Smoke Transport, or CFAST, a fire modeling program validated by real fire experiments, Cleary said.

The authors ran 5,041 simulations, with slight but critical variations between each. Different pieces of furniture throughout the house ignited with every run. Windows and bedroom doors were randomly configured to be open or closed. And the front door, which always started closed, opened up at some point to represent evacuating occupants. Heat detectors placed in the rooms produced temperature data until they were inevitably disabled by the intense heat.

To learn about P-Flash's ability to predict flashovers after heat detectors fail, the researchers split up the simulated temperature recordings, allowing the algorithm to learn from a set of 4,033 while keeping the others out of sight. Once P-Flash had wrapped up a study session, the team quizzed it on a set of 504 simulations, fine-tuned the model based on its grade and repeated the process. After attaining a desired performance, the researchers put P-Flash up against a final set of 504.

The researchers found that the model correctly predicted flashovers one minute beforehand for about 86% of the simulated fires. Another important aspect of P-Flash's performance was that even when it missed the mark, it mostly did so by producing false positives -- predictions that an event would happen earlier than it actually did -- which is better than the alternative of giving firefighters a false sense of security.

"You always want to be on the safe side. Even though we can accept a small number of false positives, our model development places a premium on minimizing or, better yet, eliminating false negatives," said NIST mechanical engineer and corresponding author Wai Cheong Tam.

The initial tests were promising, but the team had not grown complacent.

"One very important question remained, which was, can our model be trusted if we only train our model using synthetic data?" Tam said.

Luckily, the researchers came across an opportunity to find answers in real-world data produced by Underwriters Laboratories (UL) in a recent study funded by the National Institute of Justice. UL had carried out 13 experiments in a ranch-style home matching the one P-Flash was trained on, and as with the simulations, ignition sources and ventilation varied between each fire.

The NIST team trained P-Flash on thousands of simulations as before, but this time they swapped in temperature data from the UL experiments as the final test. And this time, the predictions played out a bit differently.

P-Flash, attempting to predict flashovers up to 30 seconds beforehand, performed well when fires started in open areas such the kitchen or living room. But when fires started in a bedroom, behind closed doors, the model could almost never tell when flashover was imminent.

The team identified a phenomenon called the enclosure effect as a possible explanation for the sharp drop-off in accuracy. When fires burn in small, closed-off spaces, heat has little ability to dissipate, so temperature rises quickly. However, many of the experiments that form the basis of P-Flash's training material were carried out in open lab spaces, Tam said. As such, temperatures from the UL experiments shot up nearly twice as fast as the synthetic data.

Despite revealing a weak spot in the tool, the team finds the results to be encouraging and a step in the right direction. The researchers' next task is to zero in on the enclosure effect and represent it in simulations. To do that they plan on performing more full-scale experiments themselves.

When its weak spots are patched and its predictions sharpened, the researchers envision that their system could be embedded in hand-held devices able to communicate with detectors in a building through the cloud, Tam said.

Firefighters would not only be able to tell their colleagues when it's time to escape, but they would be able to know danger spots in the building before they arrive and adjust their tactics to maximize their chances of saving lives.

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CAPTION

Researchers simulated more than 5,000 fires in a digital three-bedroom house, with crucial details such as the fire origin varying between each. The team's machine learning-based tool, P-Flash, correctly predicted whether a flashover (a potentially deadly phenomena) occurred 86% of the time based on simulated temperature data.

CREDIT

NIST

Amazon backs marijuana legalization, drops weed testing for some jobs

(Reuters) - Amazon.com Inc said on Tuesday it supports a proposed U.S. legislation to legalize cannabis at the federal level, and would drop weed-testing requirements for some recruitments

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© Reuters/BRENDAN MCDERMID Amazon's JFK8 distribution 

center in Staten Island, New York City

The e-commerce company's public policy team will be actively supporting The Marijuana Opportunity Reinvestment and Expungement Act of 2021 (MORE Act), which seeks to legalize marijuana at the federal level, its consumer boss Dave Clark said in a blog post.

Amazon will also no longer screen its job applicants for marijuana use for any positions not regulated by the Department of Transportation, Clark added.

While many U.S. states have legalized marijuana use, employers have so far largely refused to work with the industry as cannabis is still a classified substance at the federal level.

"In the past, like many employers, we've disqualified people from working at Amazon if they tested positive for marijuana use," Clark said. "However, given where state laws are moving across the U.S., we've changed course."

Amazon was hit with a proposed class action suit, which claimed that the company was violating a New York City law by testing applicants for jobs at local facilities for marijuana, according to a Westlaw report. https://reut.rs/3uHPxM6

The company does not allow marijuana sales on its platform.

Amazon also said it is tweaking its worker productivity tracking tool, "Time off Task."

"Starting today, we're now averaging Time off Task over a longer period to ensure that there's more signal and less noise—reinforcing the original intent of the program," Clark said.

(Reporting by Akriti Sharma in Bengaluru; editing by Uttaresh.V)

Opinion: Millions of vacant jobs add up to a massive wake-up call
Opinion by Jill Filipovic CNN

As life in the United States tiptoes back toward something resembling Before Times, many employers are facing an unexpected problem: they can't hire the workers they need. Despite unemployment numbers in the millions, some 8.1 million job vacancies remain. This problem is concentrated among America's low-wage workforce, hitting restaurants, warehouses, manufacturers and the service industry.

A "Now Hiring" sign outside a business in Lithonia, Georgia, U.S., on Monday, April 26, 2021. The U.S. economy is on a multi-speed track as minorities in some cities find themselves left behind by the overall boom in hiring, according to a Bloomberg analysis of about a dozen metro areas. Photographer: Elijah Nouvelage/Bloomberg via Getty Images

Many Republicans see these numbers and conclude the problem is unemployment payments that are, in their estimation, doled out to lazy people unwilling to work. Two dozen Republican-governed states have refused the federally funded $300 weekly unemployment supplement, and 36 states now require that anyone receiving unemployment benefits prove that they've looked for work unsuccessfully. Not content with red state refusal alone, Senate Republicans are trying to cut off the $300 benefit for the whole country. "We should not be in the business of creating lucrative government dependency that makes it more beneficial to stay unemployed rather than return to work," Sen. Roger Marshall of Kansas, who is leading the Senate charge to cut off the benefit, wrote in the Kansas City Business Journal.

In Michigan, the seven Republicans in their Congressional delegation are demanding an end to the federal supplement, contending in a letter to Democratic Gov. Gretchen Whitmer that: "Unfortunately, these benefits remain so robust that employees are more incentivized to stay home and collect unemployment than to go back to work."

In reality, researchers have found that the unemployment benefit's impact on the labor shortage is fairly small. Think about it this way, write Nicolas Petrosky-Nadeu and Robert G. Valletta of the Federal Reserve Bank of San Francisco: "(in) each month in early 2021, about seven out of 28 unemployed individuals receive job offers that they would normally accept, but one of the seven decides to decline the offer due to the availability of the extra $300 per week in UI payments."

That hasn't stopped conservative groups from blaming the labor shortage on basic support for workers. The Chamber of Commerce released a statement saying that "the $300 benefit results in approximately one in four recipients taking home more in unemployment than they earned working." And that's a big part of the problem: It's not that unemployment benefits are too high -- $300 a week barely covers the rent for the average family in most US states. It's that pay is far too low

 

This should be a wake-up call for a country that has spent decades                 mistreating, neglecting and radically underpaying its workers.

Consider: The US has not raised the federal minimum wage in more than a decade, and $7.25 an hour was a paltry sum even then. If today's minimum wage were commensurate with productivity increases over the last 50 years, it would be $22 an hour. Workers' purchasing power has been stagnant for 40 years, and even though workers are more productive than ever, their compensation has barely budged since the 1970s. Even more egregious is the minimum wage for tipped workers, which is an insulting $2.13 an hour, a number that hasn't gone up in 30 years.

Progressive advocates are pushing for a $15 hourly minimum wage, a more than reasonable ask, although woefully inadequate: a $15 wage would still not cover the basic living expenses and necessities of a family of four in much of the country.

As it stands, some of the country's largest employers of low-wage workersare seeing their companies' paltry pay subsidized by the federal government. McDonalds and Wal-Mart, for example, pay their employees so badly that they are among the top employers of Americans who rely on Medicaid for healthcare and food stamps for basic sustenance, according to a study last year by the Government Accountability Office. When 70% of recipients of federal aid work full-time, according to the study, and are still so poor they qualify for help from the government, something has gone very, very wrong. It's clear that employers are being given free rein to exploit their workers, while the government picks up the tab.

Some employers say that they simply cannot afford to pay a living wage. But that failure should fall on the business, not on would-be employees. Businesses have been badly hurt by the pandemic, and while they've received some governmental support, it's been wildly inadequate. But even outside of pandemic times, workers were struggling, while too many businesses felt entitled to a steady supply of poorly-paid workers, often assigning them unpredictable and exhausting schedules that came along with inconsistent income. That is not a good or sustainable business model, and it's not one we should return to.

But it's likely not just too little pay keeping would-be workers from surging into the workforce -- there is also fear of illness (Covid still isn't over), lack of affordable childcare and a general recalibration of priorities and goals after a once-in-a-century pandemic. That recalibration is happening at every level, as white-collar employees push for greater workplace flexibility and their employers navigate how to structure the return to the office.

The big difference is that when the typically better-educated and better-paid office workers revolt against inflexible workplaces and bosses who make what they believe to be unreasonable and potentially physically dangerous demands, we generally applaud them -- and increasingly, their employers are taking note and working to create workplace policies that give employees at least some of what they want (especially if what they want is remote work, which can mean employers get even more of their employees' time for less money). But when lower-paid wage workers revolt against meager wages, jobs that put them on the front line of potential Covid infection and workplaces that are often rife with harassment, abuse and disrespect, they're often treated like ingrates leeching off the government dime.

Covid brought to the fore -- and exacerbated -- just how unequal our country is. Despite shutdowns wreaking havoc on the economy, well-compensated and disproportionately college-educated workers were much more likely to have kept their jobs or seen their employment recover than workers with a high school education or less working in lower-paid fields; they even managed to save significant amounts of money, which many of them have been pouring into down payments on new homes. There's also a stunning racial gap in both Covid infections and deaths and Covid-related unemployment. All of the statistics we heard about women being pushed out of the workforce when schools and childcare facilities shut down? Those women were disproportionately Black mothers, single mothers and mothers without a college degree.

A pandemic that upended so many of our lives and killed more than half a million Americans was bound to make a lot of us reconsider how we were living before. Our country may treat wage workers as disposable automatons, but if the past year has taught us anything, it should be how much we need the folks who deliver our food, stock our grocery store shelves, care for our children and tend to our ill and aging. After a year of being deemed "essential," many of these same folks are no doubt wondering why they aren't treated as such: why they aren't paid enough to afford food and rent, why they have to tolerate sexual harassment on the job, why they're given so little of the autonomy and responsibility that all workers need to feel valued and satisfied. It's about money, yes. But it's also about a desire to be treated like a human being.

The solutions are not that complicated. A $15 federal minimum wage is the baseline; really, we should triple it, and do away with the tipped minimum wage entirely. High-quality universal childcare should be at the top of the government's To Do list to ensure that no parent has to choose between work and their children's care. Next on that list should be paid sick and vacation days, paid parental leave and laws mandating predictable work schedules. And workplaces simply need to be more humane, with employers and bosses treating their employees like trustworthy adults, not potentially naughty children in need of constant control and hyper-surveillance.

This is a difficult time for many businesses, especially the restaurants, bars, shops and small businesses that were hit hard by Covid shutdowns and regulations. I imagine most Americans would say that it's these businesses that keep our communities vibrant, and we desperately want them to recover. They absolutely deserve support from both customers and the government in getting back on their feet.

But so do their employees who are, after all, the people who make our most beloved places so great.

© Courtesy of Jill Filipovic 

Deaths of residential school children ‘the fault of Canada,’ Trudeau tells debate

INCLUDING PAST PM'S MACDONALD, TRUDEAU SR. 

& CHRETIEN***

Hannah Jackson

GLOBAL NEWS

Warning: Some of the details in this story may be disturbing to some readers. Discretion is advised.

© THE CANADIAN PRESS/Adrian Wyld Prime Minister Justin Trudeau responds to a question during Question Period in the House of Commons Wednesday April 21, 2021 in Ottawa.

Prime Minister Justin Trudeau and Members of Parliament are taking part in an emergency take-note debate in the House of Commons, days after the remains of more than 200 Indigenous children were discovered buried beneath a former residential school in British Columbia.

Trudeau told the House of Commons that the children found in Kamloops and others who have "yet to be found in other places across the country, would have been grandparents or great-grandparents."

Video: Trudeau reflects on loss of 215 children buried at former Kamloops residential school

"They would have been Elders, Knowledge Keepers and community leaders," he continued. "They are not, and that is the fault of Canada."

Trudeau said the children should have never been separated from their families and taken to the residential schools, where they suffered “terrible loneliness" and suffered "unthinkable abuse."

Read more: Ottawa has millions still to spend on missing children and cemetery searches

On Thursday, the chief of the Tk’emlúps te Secwépemc confirmed it had found the remains of the 215 children, buried on the site of the former Kamloops Indian Residential School.

The remains were found using ground-penetrating radar.

Chief Rosanne Casimir called the discovery “unthinkable,” but said the presence of the remains was “a knowing” in the Tk’emlúps community.

Crown-Indigenous Relations Minister Carolyn Bennett told the House of Commons that "we are all profoundly shaken by this horrifying discovery."

"Our thoughts are with the Tk’emlúps te Secwépemc First Nation as they mourn and come together to heal and support one another," she said.

Bennett said the federal government will "be there to support the Tk’emlúps and all communities across Canada affected by missing children and the legacy of residential schools and the intergenerational trauma inflicted."

She said the government is also committed to supporting survivors, their families and communities across the country to locate and "memorialize through ceremony, the children who died or went missing while attending residential schools."

Speaking during the debate, Conservative leader Erin O'Toole said the residential school system is a "dark and painful part" of Canada's history.

"Tragically, new chapters are still being added to this sad history," he said.

Read more: ‘They were monsters that did this:’ Kamloops residential school survivor speaks out

O'Toole again called on the Trudeau Liberals to follow through on a specific set of recommendations from the Truth and Reconciliation Commission of Canada's (TRC) report which focus on missing children and burial information.

Winnipeg MP Leah Gazan says residential schools should be ‘treated as a crime scene’

O'Toole said his party would work with the federal government to ensure the recommendations from the commission are completed.

NDP leader Jagmeet Singh said the uncovering of the site in Kamloops was not a surprise, but said it "opened up wounds" and is something that "requires healing," adding that the federal government has a large role to play in supporting that healing.

NDP MP Leah Gazan called for all residential school sites to be blocked off "immediately" as active crime scenes “so Indigenous nations, survivors and families can decide how they want to proceed in their search for their loved ones.”

'It happened at every school'

In an interview with Global News on Monday, Assembly of First Nations National Chief Perry Bellegarde said the federal government must act swiftly to determine if there are other burial sites out there.

"There was over 130 residential schools in Canada, and it happened at every school."

Bellegarde said the discovery of the mass grave has made the truth undeniable.

Read more: Residential schools: What we know about their history and how many died

"You've got to get the sonar technology that's required to do the proper investigations and research and get this done sooner than later, because families need to know. Families need that healing time," Bellegarde said.

Accoridng to the TRC, at least 150,000 First Nations, Inuit and Métis children passed through the residential school system in Canada.

Anyone experiencing pain or distress as a result of their residential school experience can access a 24-hour, toll-free and confidential National Indian Residential School Crisis Line at 1-866-925-4419

-With a files from Global News' Rachel Gilmore and Leslie Young

***

 CHRETIEN WAS MINISTER OF INDIAN AFFAIRS UNDER TRUDEAU SENIOR

BEFORE BECOMING PM HIMSELF

SIR JOHN A MACDONALD WAS CANADA'S FIRST PM A TORY