Culture

Antibodies are remarkable biomarkers: they are the cues that provide us with indications about many diseases and how our immune system counter them. Now a group of scientists from the University of Rome, Tor Vergata (Italy) has found a way to repurpose them so that they can trigger a specific chemical reaction.

"We demonstrated a strategy to use specific antibodies to control chemical reactions forming a wide range of molecules, from imaging to therapeutic agents." says Francesco Ricci, full professor at the University of Rome Tor Vergata and senior author of the article. "Our approach allows to synthesize a functional molecule from inactive precursors only when a specific antibody is present in the reaction mixture".

To achieve this goal, the researchers took advantage of the versatility of synthetic DNA oligonucleotides and of the predictability of DNA-DNA interactions. "Synthetic oligonucleotides are amazing molecules, they can be modified with a range of reactive groups and also with recognition elements that can target specific antibodies." says Lorena Baranda, PhD student in the group of Prof. Ricci and first author of the article. "In our work we rationally designed and synthesized a pair of modified DNA sequences that can recognize a specific antibody and bind to it. When this happens the reactive groups appended on the other ends of the DNA strands will be in close proximity and their reaction will be triggered ultimately leading to the formation of a chemical product", she explains.

The strategy demonstrated in this work can be used, for example, to control the formation of functional molecules, such as therapeutic agents, with biomarker antibodies. As a proof of principle of this possible application the researchers demonstrated the formation of an anticoagulant drug able to inhibit the activity of thrombin, a key enzyme of blood coagulation and an important target for the treatment of thrombosis. "We demonstrated that a specific IgG antibody can trigger the formation of the anticoagulant agent, which was further proven to efficiently inhibit the activity of thrombin" says Prof. Ricci. "The strategy is highly specific to the antibody of interest and also programmable. We envision it would represent a new avenue to targeted therapy and diagnostics", he concludes.

Adipose tissue is not just a simple reservoir of energy for periods of food scarcity. It contributes significantly to regulation of the metabolism, releasing various molecules into the bloodstream, including microRNAs that modulate the expression of key genes in different parts of the organism, including the liver, pancreas, and muscles.

Research has shown that both aging and obesity can impair the production of these regulatory microRNAs by adipose tissue and favor the development of diseases such as diabetes and dyslipidemia. The good news is that this degenerative process can be reversed by practicing regular aerobic exercise, according to a study published in Proceedings of the National Academy of Sciences (PNAS).

"Experiments with mice and humans have shown that aerobic exercise stimulates expression of an enzyme called DICER, which is essential to the processing of these microRNAs. We, therefore, observed an increase in production of these regulatory molecules by adipose cells, with several benefits for the metabolism," said Marcelo Mori, a professor at the University of Campinas's Institute of Biology (IB-UNICAMP) in the state of São Paulo, Brazil, and one of the principal investigators for the project, which was supported by FAPESP (São Paulo Research Foundation) and conducted in partnership with groups at the University of Copenhagen in Denmark and Harvard University in the United States.

The experiments were performed during the postdoctoral research of Bruna Brasil Brandão, formerly Mori's PhD student and now at Harvard Medical School working as a research fellow in the laboratory of Professor C. Ronald Kahn.

The results showed the occurrence of communication between muscle and adipose tissue during aerobic exercise via signaling molecules secreted into the bloodstream. This exchange of information makes energy consumption by adipose cells more efficient, enabling the metabolism to adapt to exercise and enhancing the performance of the muscles.

The mice were subjected to a 60-minute treadmill running protocol for eight weeks. As they became fitter, treadmill speed and inclination were increased. At the end, in addition to the improvement in performance, the scientists found a significant elevation in adipocyte levels of DICER expression, which was accompanied by a reduction in body weight and visceral fat.

When they repeated the experiment with mice that were genetically modified not to express DICER in adipose cells, the researchers found that the beneficial effects of aerobic exercise were far smaller. "The animals didn't lose weight or visceral fat, and their overall fitness didn't improve," Mori said. "We also observed that adipose cells used the energy substrate differently in these GM mice than in wild mice, leaving less glucose available for muscles."

In humans, six weeks of high-intensity interval training (HIIT) were sufficient to yield a fivefold increase in the amount of DICER in adipose tissue on average. The effect was observed in both younger volunteers, aged about 36, and older subjects, aged about 63. The response varied considerably between individuals, however, with DICER increasing as much as 25 times in some, and very little in others.

Detailed mechanism

The role of DICER and microRNA processing in adipose tissue was first described in 2012 in an article published in Cell Metabolism, reporting a study led by Mori and Khan in collaboration with an international group of researchers. The main finding here was that expression of DICER in the adipose tissue of mice declined as the animals gained weight and that this reduced their lifespan. The study also showed that caloric restriction could reverse the deleterious effects of obesity.

In another study, published in 2016 in the journal Aging, Mori and his group showed that caloric restriction in mice prevented the aging-related decline in microRNA production by adipose tissue and the development of type 2 diabetes. In a study reported in 2017 in Nature, they proved that the microRNAs produced by adipose tissue entered the bloodstream and acted on distant tissues, regulating gene expression.

"In this latest study we found that aerobic exercise, like caloric restriction, can reverse the drop in DICER expression and microRNA production thanks to the activation of a very important metabolic sensor, the enzyme AMPK [adenosine monophosphate-activated protein kinase]," Mori said.

The sensor is activated, he explained, when the cell consumes ATP (adenosine triphosphate, the molecule that acts as an energy substrate for cells) and creates an energy deficit. In experiments with mice, the researchers found that aerobic exercise activated AMPK in muscle cells and that this somehow induced DICER expression in adipose cells.

"The obvious conclusion is that the effect on gene expression occurs in the same cell in which the energy deficit occurs, which is indeed the case, but here the sensor is also activated in muscles and controls the response that occurs in adipose tissue," he said.

To confirm communication between tissues, the scientists collected blood serum from a trained animal and injected it into a sedentary animal. This "treatment" increased DICER expression in adipose tissue. In another experiment, they incubated cultured adipocytes with serum from trained mice and observed the same effect.

"This finding suggests trained individuals have one or more molecules in their bloodstream that directly induce a metabolic improvement in adipose tissue," Mori said. "If we can identify these molecules, we can investigate whether they also induce other benefits of aerobic exercise, such as cardioprotection. Moreover, we may think about converting this knowledge into a drug at some stage."

To obtain an even more detailed understanding of the metabolic regulation mechanism, the researchers analyzed all of the thousands of microRNAs expressed in the organism of the trained mice and compared them with those found in sedentary mice.

"We identified a molecule called miR-203-3p, whose expression increases with both training and caloric restriction," Mori said. "We showed that this microRNA is responsible for promoting metabolic adjustment in adipocytes. When muscles use up all their glycogen during prolonged exercise, molecular signals are sent to adipose tissue and miR-203-3p fine-tunes the adipocyte metabolism. We found this metabolic flexibility to be essential to good health as well as performance enhancement."

Absent this modulation, adipocyte consumption of glucose during exercise increases, leaving less energy substrate available to muscles, he added. This can lead to hypoglycemia, one of the main performance limitations for athletes.

"In GM mice that don't express DICER in adipocytes, this conversation between adipose tissue and muscles doesn't happen. It's a model that mimics aging and obesity. So when DICER declines, metabolic health is poor and degenerative processes accelerate" Mori said.

Enormous efforts are being made worldwide in a technological field that could far surpass the capabilities of conventional electronics: spintronics. Instead of operating based on the collective movement of charged particles (electrons), spintronic devices could perform memory storage and data transmission by manipulating spin, an intrinsic property of elementary particles related to angular momentum and from which many magnetic characteristics in materials arise. Unfortunately, controlling spin has proven to be a challenging endeavor, leading physicists and engineers to look for efficient materials and techniques to do so.

In this regard, antiferromagnetic materials (AFMs) are good candidates for spintronics because they are resistant to external magnetic fields and allow for switching spin values in timescales of picoseconds. One promising strategy to manipulate spin orientation in AFMs is using an optical laser to create extremely short-lived magnetic field pulses, a phenomenon known as the inverse Faraday effect (IFE). Although the IFE in AFMs generates two very distinct types of torque (rotational force) on their magnetization, it now seems the most important of the two has somehow been neglected in research.

In a recent study published in Nature Communications, a trio of scientists, including Professor Takuya Satoh from the Tokyo Tech, Japan, delved deep into this issue. Spin dynamics in AFMs are described by a sum of two terms: field-like torque and damping-like torque (Figure 1). The latter, as the word 'damping' implies, is related to the gradual decay (or dying off) of the spin oscillations triggered by the optical pulses on the material.

Until now, scientists studied the damping-like torque only from the perspective of spin relaxation after excitation, believing its amplitude to be small during the ultrashort spin excitation process. In this study, however, Prof Satoh and colleagues found it to be, in some cases, the main player in terms of spin reorientation due to the IFE. Through theoretical analyses and experimental verification in both YMnO3 and HoMnO3, they clarified the conditions under which the damping effect becomes the dominant spin excitation mechanism.

A simplified interpretation of the findings can be as follows. Imagine a hanging pendulum (magnetization direction) oscillating in wide arcs, drawing a very pronounced ellipse. The damping-like torque produces a large instantaneous perturbation in the direction of the small diameter, 'tipping it off' and causing it to lean like a spinning top that is about to fall. "The otherwise small damping-related magnetization causes a large spin canting because of the extreme ellipticity inherent to AFMs," explains Prof Satoh. "Considering that it is possible to adjust the strength of the damping by strategically selecting the ions in the AFM, we might have found a way to tune material properties for specific spintronic applications," he adds.

The trio of scientists also tested how spin dynamics are influenced by temperature, which affects and even destroys antiferromagnetic order past certain thresholds. By putting the materials close to the critical transition points, they managed to produce a more pronounced effect from damping-type torque. Excited about the results, Prof Satoh remarks: "Our results indicate that optically generated torques might provide the long sought-after tool enabling the efficient realization of ultrafast spin switching in AFMs."

Although much more research will certainly be needed before applied spintronics becomes a reality, uncovering efficient mechanisms for spin manipulation is obviously among the first steps. This study proves that such mechanisms might be hidden in phenomena we know and neglect!

Well-known for its bactericidal and anti-fungal properties, Brazilian red propolis has now been found to act powerfully against the parasite that causes schistosomiasis, reducing the number of eggs and killing the helminths (worms).

In experiments performed at Universidade Guarulhos (UnG) in the state of São Paulo, Brazil, with FAPESP’s support, 400 milligrams per kilogram of body weight was a sufficient dose of red propolis to reduce the parasite load by more than 60% in mice infected with the flatworm Schistosoma mansoni. It was equally effective against the immature and adult stages of the parasite. In vitro tests also showed that red propolis blocked reproduction and oviposition (egg-laying).

“Propolis, especially the red variety, is well-known for its action against bacteria and fungi. It protects the beehive from intruders, and we expected that some of its more than 20 substances would act against parasitic infectious agents. What surprised us was that it disrupted the worm’s integument and killed adult as well as immature worms, which the conventional treatment for schistosomiasis doesn’t do,” said Josué de Moraes, a professor at UnG and last author of the article on the study published in the Journal of Ethnopharmacology.

The results of all the tests suggest red propolis may be more effective to treat schistosomiasis than the only pharmaceutical product available for this purpose. Before red propolis can be prescribed for patients, of course, it must be tested in clinical trials on humans with the disease.

Super-helminths

Schistosomiasis is the most common disease caused by helminths and affects some 300 million people worldwide. Despite its high prevalence in tropical and subtropical areas, it has been treated with a single drug for about 40 years.

“Praziquantel is effective but has major limitations,” Moraes said. “In contrast with what we found in the study with red propolis, the drug doesn’t combat infections caused by the immature stage of the parasite. It kills only adult worms, so patients have to wait until the growth cycle reaches the adult stage to start the treatment, by which time the infection has become chronic.”

Another limitation of praziquantel is that some species have become drug-resistant after 40 years with no alternative treatment. Schistosome strains with low susceptibility to the drug have been isolated by researchers.

The research project led by Moraes at UnG’s Center for Research on Neglected Diseases (NPDN) aims at drug repurposing to tackle schistosomiasis. “Because it’s a neglected disease linked to poverty and lack of basic sanitation, this is basically the only way to find novel therapies. Repurposing is cheaper and quicker than developing new drugs from scratch,” Moraes said.

The research group tested 73 nonsteroidal anti-inflammatory drugs sold in Brazil and elsewhere. They found five to be effective against the disease, with mefenamic acid (widely used for menstrual period pain relief) exhibiting the most promising results to date (read more at: agencia.fapesp.br/31372).

In an article published in mid-2020 in Trends in Parasitology, Moraes and a co-author note that the United States’ Food and Drug Administration (FDA) has approved very few drugs for the treatment of parasitic diseases.

“Since the start of the century, the FDA has approved a total of 604 medications, some of which are novel drugs and others repurposed,” Moraes said. “Only nine are antiparasitics, and of these only two are anthelmintics. In my view, helminthiases are the most neglected of neglected diseases.”

Why red propolis?

Moraes explained that the decision to study the effects of red propolis in this project was made because the natural product had been fully characterized in studies by Severino M. Alencar, a researcher at the University of São Paulo’s Luiz de Queiroz College of Agriculture (ESALQ-USP), and Bruno Bueno-Silva at UnG’s Dentistry Department. Both are collaborators with NPDN.

“Brazilian red propolis has attracted attention in recent years owing to its pharmacological potential as well as its anti-microbial and anti-inflammatory action,” he said. “Our study didn’t investigate the mechanism of red propolis in the schistosome but analyzed the action of red propolis extract indirectly using scanning electron microscopy. For example, we set out to see if this natural product, which is made up of several substances, could get through the parasite’s integument. This would increase its power to reach one or more targets and kill the worms, but we didn’t identify any targets.”

Green and brown propolis are likely to have some effect on schistosomiasis, Moraes added, but specific studies will be needed to analyze the other two natural products.

The discovery could also be applicable to other verminoses. “The schistosome is a model for the study of infections in humans and animals caused by other flatworms, or platyhelminths, such as tapeworms of the genus Taenia,” he said. “The discovery, therefore, creates an opportunity for research relating to the treatment of other diseases that affect humans, cats, and dogs, and are also treated with praziquantel.”

In direct contradiction to the official forecast, a team of scientists led by the National Center for Atmospheric Research (NCAR) is predicting that the Sunspot Cycle that started this fall could be one of the strongest since record-keeping began.

In a new article published in Solar Physics, the research team predicts that Sunspot Cycle 25 will peak with a maximum sunspot number somewhere between approximately 210 and 260, which would put the new cycle in the company of the top few ever observed.

The cycle that just ended, Sunspot Cycle 24, peaked with a sunspot number of 116, and the consensus forecast from a panel of experts convened by the National Aeronautics and Space Administration (NASA) and the National Oceanic and Atmospheric Administration (NOAA) is predicting that Sunspot Cycle 25 will be similarly weak. The panel predicts a peak sunspot number of 115.

If the new NCAR-led forecast is borne out, it would lend support to the research team's unorthodox theory - detailed in a series of papers published over the last decade - that the Sun has overlapping 22-year magnetic cycles that interact to produce the well-known, approximately 11-year sunspot cycle as a byproduct. The 22-year cycles repeat like clockwork and could be a key to finally making accurate predictions of the timing and nature of sunspot cycles, as well as many of the effects they produce, according to the study's authors.

"Scientists have struggled to predict both the length and the strength of sunspot cycles because we lack a fundamental understanding of the mechanism that drives the cycle," said NCAR Deputy Director Scott McIntosh, a solar physicist who led the study. "If our forecast proves correct, we will have evidence that our framework for understanding the Sun's internal magnetic machine is on the right path.

The new research was supported by the National Science Foundation, which is NCAR's sponsor, and NASA's Living With a Star Program.

Sunspot Cycle 25 starts with a bang; what will follow?

In McIntosh's previous work, he and his colleagues sketched the outline of a 22-year extended solar cycle using observations of coronal bright points, ephemeral flickers of extreme ultraviolet light in the solar atmosphere. These bright points can be seen marching from the Sun's high latitudes to the equator over about 20 years. As they cross the mid-latitudes, the bright points coincide with the emergence of sunspot activity.

McIntosh believes the bright points mark the travel of magnetic field bands, which wrap around the Sun. When the bands from the northern and southern hemispheres - which have oppositely charged magnetic fields - meet at the equator, they mutually annihilate one another leading to a "terminator" event. These terminators are crucial markers on the Sun's 22-year clock, McIntosh says, because they flag the end of a magnetic cycle, along with its corresponding sunspot cycle, -- and act as a trigger for the following magnetic cycle to begin.

While one set of oppositely charged bands is about halfway through its migration toward the equatorial meetup, a second set appears at high latitudes and begins its own migration. While these bands appear at high latitudes at a relatively consistent rate -- every 11 years -- they sometimes slow as they cross the mid-latitudes, which appears to weaken the strength of the upcoming solar cycle.

This happens because the slowdown acts to increase the amount of time that the oppositely charged sets of bands overlap and interfere with one another inside the Sun. The slow-down extends the current solar cycle by pushing the terminator event out in time. Shifting the terminator out in time has the effect of eating away at the spot productivity of the next cycle.

"When we look back over the 270-year long observational record of terminator events, we see that the longer the time between terminators, the weaker the next cycle," said study co-author Bob Leamon, a researcher at the University of Maryland Baltimore County. "And, conversely, the shorter the time between terminators, the stronger the next solar cycle is.

This correlation has been difficult for scientists to see in the past because they have traditionally measured the length of a sunspot cycle from solar minimum to solar minimum, which is defined using an average rather than a precise event. In the new study, the researchers measured from terminator to terminator, which allows for much greater precision.

While terminator events occur approximately every 11 years and mark the beginning and end of the sunspot cycle, the time between terminators can vary by years. For example, Sunspot Cycle 4 began with a terminator in 1786 and ended with a terminator in 1801, an unprecedented 15 years later. The following cycle, 5, was incredibly weak with a peak amplitude of just 82 sunspots. That cycle would become known as the beginning of the "Dalton" Grand Minimum.

Similarly, Sunspot Cycle 23 began in 1998 and did not end until 2011, 13 years later. Sunspot Cycle 24, which is just ending, was quite weak as well, but it was also quite short -- just shy of 10 years long - and that's the basis for the new study's bullish prediction that Sunspot Cycle 25 will be strong.

"Once you identify the terminators in the historical records, the pattern becomes obvious," said McIntosh. "A weak Sunspot Cycle 25, as the community is predicting, would be a complete departure from everything that the data has shown us up to this point.

As municipalities have taxed sugar-sweetened beverages and schools and worksites have banned their sales, university researchers have found that simple warning labels on such beverages in a college cafeteria helped students reduce their reported consumption of drinks by 14.5 percent. The results signal that such labels could reduce sugar consumption in larger settings.

"Sugar-sweetened beverages are a major driver of chronic disease. Health warning labels may reduce the intake of sugar-sweetened beverages, but the effectiveness of such labels in real-world settings is only beginning to be established," said Jennifer Falbe, assistant professor of Nutrition and Human Development at University of California, Davis, who is a senior author of the study and designed the warning label used. "This experiment takes the evidence a step further by looking at young adult behavior in a setting that they frequent each day," she said. The study was conducted by the University of Michigan School of Public Health and UC Davis.

Taking a cue from tobacco control efforts, researchers placed warning labels on beverage dispensers at a University of Michigan cafeteria for one semester in 2019. In language based on previous proposed California legislation, the bright yellow labels with a large triangle and exclamation mark state:

"Warning: Drinking beverages with added sugar(s) contributes to type 2 diabetes, heart disease, and tooth decay." Two other cafeterias on campus -- located geographically distant from the cafeteria with the labels -- served as control sites, and displayed no warning labels.

Nearly 1,000 college students were contacted by email before and after the warning labels were implemented to ask them to participate in surveys with no specific mention of sugar-sweetened beverages. Participants were given a $10 gift card after completing each survey.

In total, 840 students across all cafeterias were included in the study. At the intervention site, consumption of sugar-sweetened drinks that had the warning label declined by 18.5 percent compared to a decline of 4.7 percent at the control sites at which no label was used. Students exposed to the warning labels also reduced their consumption of 100-percent juice drinks by 21 percent even though, in the experiment, juices had not been labeled as sugar-sweetened beverages.

A tool to reduce sugar consumption

"The results of this study indicate that warning labels may be effective tools for reducing consumption of sugar-sweetened beverages, particularly beverages such as sweetened teas, pink lemonade and chocolate milk for which the sugar content is not immediately obvious or well known," said Cindy Leung, assistant professor of Nutritional Sciences at the University of Michigan School of Public Health and lead author of the study.

"Sugar-sweetened beverages remain ubiquitous in retail and cafeteria settings. As we explore avenues to promote healthy food and beverage choices, warning labels are a potential tool to reduce their consumption that should be tested in other populations and other settings." said Julia Wolfson, assistant professor of Health Management and Policy at the U-M School of Public Health and co-author of the study.

The study, "Warning Labels Reduce Sugar-Sweetened Beverage Intake among College Students," was published last month in the Journal of Nutrition. Additional co-authors are Robert Hsu, Keith Soster and Steve Mangan, all of University of Michigan, Ann Arbor. Falbe teaches in the UC Davis Department of Human Ecology.

"These results provide evidence to inform future institutional strategies... and legislative efforts to use warning labels as a promising approach to SSB consumption," the researchers concluded.

For instance, nine jurisdictions, including California, have introduced, at various times, sugar-sweetened beverage warning label legislation. "These laws could ensure that consumers have the necessary information to make informed choices," Falbe said.

The creosote is the king of the desert. This scraggly shrub dominates the landscape of the American southwest, creating mini-oases from the harsh heat for desert wildlife.

In a new study, researchers at The University of Texas at Austin leveraged computer algorithms and high-resolution survey data to conduct the first-ever creosote census - counting every creosote in a 135-square-mile conservation site in Nevada's Mojave Desert. The final count was 23 million creosotes among a total population of 66 million plants.

The researchers discovered important new information about the plant species, but they also demonstrate how data techniques can improve on conventional methods for studying plant communities.

"This was first and foremost a big data project," said James "Jake" Gearon, a graduate student at the UT Jackson School of Geosciences who led the study. "The majority of time was data cleaning, data investigation, data prep. By the time you get to analysis, you have discovered so many things along the way you have a path forward."

The study was published in November 2020 in the journal Landscape Ecology.

The census is a milestone for plant science. Most plant population data comes from samples of fewer than 1,000 plants or aerial surveys that capture community snapshots. This research presents a way to account for each and every individual in a plant community. The scientists also discovered that certain landscape features can influence how big creosotes grow and how far apart they are spaced.

"People are amazed at the size of the dataset. But we tried to avoid being dazzled by size and focus in the interested things the data tell us," said coauthor Michael Young, a senior research scientist at the Bureau of Economic Geology, a research unit at the Jackson School.

The creosote research is built on repurposed data collected by Young and colleagues during a 2017 aerial survey that collected aerial photos and elevation data from the Boulder City Conservation Easement in the Mojave Desert.

The data were originally collected to find burrows belonging to the threatened desert tortoise. But the high-resolution photos (one pixel is equivalent to six inches) combined with the elevation data that measured variations in each square meter of the easement, created a rich resource for new research.

Counting the creosotes involved applying computer algorithms that could distinguish the bushes from the surrounding landscape and other plants. In addition to carrying out the census, the algorithms also extracted information on each creosote's location, height, and canopy area, from which canopy volume was calculated.They also extracted information on the surrounding landscape, such as relative soil age, and slope angle and direction.

When the landscape and creosote information were analyzed together, the researchers discovered some notable trends about how the landscape influenced plant growth.

They found that direction of the slope, or aspect, was the main control on creosote volume - with the plants growing on east-facing slopes being about five times bushier than plants on west-facing slopes.

"That's five times more cover on the ground for the critters, for land use, or for understanding just how hot the ground is going to get - that has a huge impact," Gearon said.

They also found that soil age influences creosote volume, with plants in the younger soil being about 27% larger than plants in the oldest.

The connection between soil age and plant size is well documented, but the influence of hillslope aspect on plant size came as a surprise, Gearon said. That's because the research record more often relates plant growth to north and south slope directions - with few studies on east and west slopes.

But this study suggests that growing on an eastward slope could be an important way for desert plants to stay hydrated, with the placement allowing the plants to soak up the sunshine during the cooler, wetter morning hours, unlike westward slopes which receive the most sunlight during the hottest parts of the day when they're most susceptible to losing water via transpiration.

Erik Hamerlynk, a research ecologist at the U.S. Department of Agriculture, said the study is significant because of the precision of the data that comes from accounting for every individual in a population.

"This is the first time I've seen something that takes plot level data and really expands it to a landscape scale, to a basin scale," Hamerlynk said. "That's just a huge accomplishment."

He added that techniques presented in the study could help improve range management practices by offering an in-depth and standardized view of an entire plant community before and after a particular intervention.

GAINESVILLE, Fla. --- The island of Nihoa, a slice of jagged rock that juts out of the Pacific Ocean, is the sole refuge for a rediscovered species of native Hawaiian land snail previously presumed to be extinct.

First recorded in 1923, Endodonta christenseni lacked a scientific name and description until now. It is likely the last remaining species in the Endodonta genus. The other 11 species were collected and described more than 100 years ago and today are known only from museum specimens. A team of researchers from the Bishop Museum and the Florida Museum of Natural History found the snail during a survey of more than 1,000 sites across the Hawaiian Islands.

Now the scientists warn that, without protections, the species could vanish within a decade, erasing a lineage that existed for millions of years and the stories it could tell. Giving E. christenseni a name is an essential first step to conserving its remaining population, the researchers said.

"This sort of work forms the foundation for all conservation efforts," said lead author Kenneth Hayes, director of the Bishop Museum's Pacific Center for Molecular Biodiversity, in a statement. "The gap in knowledge about biodiversity, which is especially severe for understudied and highly threatened groups like snails and insects, prevents effective research needed to inform conservation actions."

Land snails in the Pacific islands have suffered more recorded extinctions in the last 400 years than any other group of animals, with declining numbers linked to habitat destruction, invasive predators and climate change. While Hawaii has lost more than half of its land snail species - once more than 750 species strong - researchers have recorded nearly 300 species widely assumed to have vanished long ago, including E. christenseni.

"The results from these extensive survey efforts give us hope that there are still many species left that can be saved," said Norine Yeung, malacology curator at the Bishop Museum and a co-principal investigator of the study. "But we need to act quickly and decisively if we are to beat the extinction clock that ticks louder with each passing day."

Museum records - ranging from the first collection of E. christenseni in 1923 to specimens dating to 1990 - enabled the team to perform targeted searches on Nihoa to see if the snail still existed, said John Slapcinsky, manager of the Florida Museum's invertebrate zoology collection.

"Having those museum specimens allowed us to target specific areas and find these things again. Everything depends on prior knowledge," he said.

Slapcinsky attributed the long gap between 1923 and the species description published this year to the scarcity of taxonomists who study land snails.

E. christenseni is about the size of a pea and has tigerlike stripes. A ground dweller, it relies on the tussocks of variable lovegrass, another native Hawaiian species, for moisture and sustenance. Slapcinsky said it likely lives and reproduces in the "wonderful little habitat" in the plant's moist center, feeding on fungal films that develop on dead blades of grass.

But the snail's decline is also linked to its highly specialized lifestyle. Many lowland grass habitats in Hawaii have been replaced by exotic vegetation, and invasive species such as ants and rats are more prevalent in low-lying areas than at high altitudes. Although Nihoa is uninhabited, with visitation highly restricted by the U.S. Fish and Wildlife Service, the researchers said it remains vulnerable to human disturbances - threats only amplified by the island's small size, where habitat disturbances can have long-term consequences.

Slapcinsky said the species has yet to recolonize two-thirds of the island ravaged by an out-of-control campfire in 1885. A network of factors - including exceptionally limited mobility, habitat specificity and slow reproduction - has likely prevented E. christenseni from re-expanding its range, he said.

The team hopes to incorporate the new species into the Hawaii Department of Land and Natural Resources' Snail Extinction Prevention Program, through which captive breeding can help researchers measure species resilience in the wild. Although DNA samples from E. christenseni and related species will help the researchers trace its evolutionary relationships, a living population will enable them to answer key ecological questions about reproduction, diet and lifecycle, all of which can help inform species recovery plans, Slapcinsky said.

He added that rediscovering land snail populations is shedding light on how they can be conserved, signaling that not all is lost for the group.

"The picture is going from one that was really miserable and hopeless to one that's a little less miserable, but hopeful," he said. "In the recent past, things looked so bad that we were thinking pretty much everything's gone. There wasn't a lot of effort into conservation of many of the land snails, so by doing these surveys and finding some of these species that are still there, we have the ability now to save whole lineages."

The name E. christenseni honors Bishop Museum scientist Carl Christensen, an expert on Pacific island land snails and an advocate for their conservation.

Nurses and other long-term care workers in nursing homes who hold multiple jobs, may be one of the factors contributing to the spread of COVID-19 in these facilities, according to a new study published in Medical Care Research and Review. The nature of their work in providing essential care to patients in rather close proximity, and the limited access to personal protective equipment for some workers, has made this profession even riskier during the pandemic. The findings examine the likelihood that nurses and direct care workers in long-term care facilities hold a second job, and how demographic differences between the two may affect this probability.

Due to low wages and limited hours, some nurses (registered nurses and licensed practical nurses) and direct care workers (certified nursing assistants, and personal and home care aides) seek secondary employment: 6.41 percent of personal care and nursing aides and 6.23 percent of licensed practical nurses and licensed nurses hold second jobs. This rate of holding a second job is 35 percent and 32 percent, respectively, higher than that of other workers.

Most nurses and direct care workers with second jobs stay within the same occupation at another location, which increases their interaction with patients and the potential for COVID-19 transmission as compared to their counterparts who have one job. Approximately 34 percent of nurses in nursing homes take second jobs in other nursing homes while nearly 30 percent of those who work in hospitals work at other hospitals. Fifty percent of direct care workers work in direct care as a second job while others work as cashiers, in retail or as a janitor or maid. Fifteen percent of second jobs for personal care and nursing aides are in other "essential occupations."

"With higher rates of second job holding among direct care workers and nurses in long-term care than other workers, and many of these workers moving across health settings from their first to second jobs, this creates a potential pathway for COVID-19 transmission," explains co-author Kristin E. Smith, a visiting associate professor of sociology at Dartmouth. "In New Hampshire, 81 percent of COVID-19 deaths are to long-term care residents, representing the highest percentage of deaths to long-term care residents in the country, so understanding employment dynamics and disparities in this sector could never be more timely than now."

The study was based on second job holding data from 2010 to 2019 from the Current Population Survey. While low wages and limited hours were associated with holding a second job for direct care workers, lower hours were more strongly correlated with second job holding among nurses. The results also showed that nurses with children and African American nurses were more likely to hold second jobs than white nurses. Female and married nurses were less likely to have a second job. Nurses had higher wages than direct care workers and worked 30 percent more hours.

White direct care workers were more likely to have second jobs than Asian, American Indian, Alaskan Native workers. Similarly, African American direct care workers were also less likely to take on second jobs when work hours were excluded from the analysis, and Hispanic workers were less likely to have a second job than their non-Hispanic counterparts. Direct care workers with more education were more likely to have a second job.

"The COVID-19 pandemic is shining the spotlight on inequalities throughout our society, particularly in healthcare systems, where we are now seeing real-life implications for loved ones in nursing homes, who are such a vulnerable population," added Smith. "Federal and state-level initiatives aimed at raising wages through bonuses that are higher than unemployment benefits could potentially help decrease the likelihood that these essential care workers must take on a second job and help reduce exposure for COVID-19 transmission."

In recent years, debate has been intensifying over whether the noncompete agreements some companies use to bind employees help or hurt workers. It's an issue management professor Evan Starr at the University of Maryland's Robert H. Smith School of Business has studied extensively -- co-authoring four research papers on the topic forthcoming in top journals. All the results point to the same conclusion: Noncompetes stifle workers.

The findings will be published as "Low Wage Workers and the Enforceability of Non-compete Agreements" in Management Science, "Locked In? The Enforceability of Covenants Not to Compete and the Careers of High-Tech Workers" in the Journal of Human Resources, "The Behavioral Effects of (Unenforceable) Contracts" in the Journal of Law, Economics, and Organization, and "Noncompete Agreements in the U.S. Labor Force" in the Journal of Law and Economics.

The latter, says Starr, represents the most sweeping work and is the first systematic investigation of noncompetes in the United States. In it, he studies a nationally representative sample, looking at all sorts of workers. One of the key findings: Noncompetes are found even among low-wage workers. "There have been anecdotes of that fact, but this is the first systematic evidence," says Starr. "This is shocking because when you think about noncompetes, you think about tech workers and executives - you're not thinking about doggie-daycare sitters or hairstylists or yoga instructors, but that's the modal worker that's bound by a noncompete. Our paper launches from that fact, and the key question for policymakers is this a good or a bad thing?"

"The argument for why they are bad is pretty clear," Starr says. Take the case of the low-wage worker, earning $12 an hour, who gets a better offer at a competitor to make $15 an hour. "A noncompete could prevent them from making those sorts of moves that are going to enhance their social and economic mobility."

So how do companies justify using these restrictions? Starr says past research argues that noncompetes give firms incentive to invest in workers to develop their skills and knowledge to make them more productive, and that boost will help the individual workers make more money than they could have otherwise.

"All states in the U.S. that enforce noncompete agreements require that workers have some sort of 'protectable,' legitimate interest, which is exactly this sort of investment: That you're giving workers trade secrets or very specialized training."

Policymakers have taken up the issue. In late 2019, Starr testified about the use of noncompetes before the U.S. House of Representatives and the U.S. Senate. Even earlier, in 2016, the U.S. Treasury and the Obama Administration used Starr's findings as the basis of related reports, spurring states to reexamine noncompete policies. In the past two years, some - including Maryland, Virginia, and Washington DC - have moved to ban noncompetes for low-wage earners. But Oregon was the trailblazer, doing so back in 2008, making it the perfect case study for Starr (in the forthcoming in Management Science paper), with co-author Michael Lipsitz, an economist for the Federal Trade Commission.

The Oregon law banned noncompete agreements for all hourly workers and for workers earning below the median income for a family of four in the United States. It also banned noncompetes for certain occupations.

"We looked broadly at hourly workers, because hourly workers comprise 67% of working population in Oregon, and it was very clear in the bill that all noncompetes are banned for hourly workers," Starr says.

The findings were clear: Low-wage workers benefited from the ban, earning higher wages and changing jobs more. On average, hourly workers' wages grew by 6% five years after the ban. The positive wage effects were across the board, in all age groups and education levels. The researchers also found that workers' job-to-job mobility rose by 17% overall, with 79% of this increase in mobility driven by an increase in moves within an industry - "exactly the kinds of moves that a noncompete would prohibit," Starr says.

The findings show that not only are workers moving to new jobs within their industries, they are also moving up to better jobs. And while men benefit from this ban on noncompetes, women benefit almost twice as much, suggesting that noncompetes were holding down the earnings of low-income women more than men, Starr says. "It could be that women are less likely to negotiate over these sorts of provisions, and so they are harmed more when these are being enforced."

The researchers analyzed how companies responded to the noncompete ban and found that there was no impact on hours worked, so firms are still employing workers, on average, for the same amount of time. "What that means is workers' take-home pay ultimately goes up - hourly wage increases translate into actual earnings increases," Starr says.

They also looked at whether firms changed compensation structures in response to the new law, because Oregon only banned noncompetes for hourly workers and those who make less than the median household income for a family of four. They find that workers earning just above that threshold were more likely to become salaried. "One perk of the structure of this bill is to get workers into more stable situations, even if they are still using noncompetes with them," Starr says.

"Despite good arguments for noncompetes potentially benefiting workers, the evidence just doesn't support that claim. The evidence suggests that these are bad for low-wage workers."

Paralleling the Oregon study, Starr's research for the Journal of Human Resources looks at a 2015 Hawaii law that banned noncompetes in the high-tech industry. His findings are the same. "After Hawaii banned noncompetes for tech workers, their wages rise, their job mobility rises. It's basically the same story but in a very different set of occupations, where arguments about the investment effects of noncompetes seem more plausible."

And, the work in the Journal of Law, Economics and Organization looks at the influence of per se unenforceable noncompete agreements. "We find that they still do matter, in fact to a similar degree as in states where they are totally enforceable. We look at why that is and find evidence that workers are proactively turning down jobs, not because of the law, but because they are scared of a lawsuit."

Collectively, Starr's papers show that workers do better without noncompete agreements. But what about firms?

Firms may be less profitable if they have to pay workers more, Starr says, but there's definitely a benefit for them too: Without noncompetes, firms have unfettered access to the labor market and can hire the workers they want to hire, including those from a competitor. "It's not really a firm versus worker issue. It could be a win for both workers and firms."

URBANA, Ill. - Walking rows of soybeans in the mid-summer heat is an exhausting but essential chore in breeding new cultivars. Researchers brave the heat daily during crucial parts of the growing season to look for plants showing desirable traits, such as early pod maturity. But without a way to automate detection of these traits, breeders can't test as many plots as they'd like in a given year, elongating the time it takes to bring new cultivars to market.

In a new study from the University of Illinois, researchers predict soybean maturity date within two days using drone images and artificial intelligence, greatly reducing the need for boots on the ground.

"Assessing pod maturity is very time consuming and prone to errors. It's a scoring system based on the color of the pod, so it is also subject to human bias," says Nicolas Martin, assistant professor in the Department of Crop Sciences at Illinois and co-author on the study. "Many research groups are trying to use drone pictures to assess maturity, but can't do it at scale. So we came up with a more precise way to do that. It was really cool, actually."

Rodrigo Trevisan, a doctoral student working with Martin, trained computers to detect changes in canopy color from drone images collected across five trials, three growing seasons, and two countries. Importantly, he was able to account for "bad" images to maintain accuracy.

"Let's say we want to collect images every three days, but one day, there are clouds or it's raining, so we cannot. In the end, when you get the data from different years or different locations, they will all look different in terms of the number of images and the intervals and so on," Trevisan says. "The main innovation we developed is how we can account for whatever we are able to collect. Our model performs well independent of how often the data was collected."

Trevisan used a type of artificial intelligence called deep convolutional neural networks. He says CNNs are similar to the way human brains learn to interpret components of images - color, shape, texture - from our eyes.

"CNNs detect slight variations in color in addition to shapes, borders, and texture. For what we were trying to do, color was the most important thing," Trevisan says. "But the advantage of the artificial intelligence models we used is that it would be quite straightforward to use the same model to predict another trait, such as yield or lodging. So now that we have these models set up, it should be much easier for people to use the same architecture and the same strategy to do many more things."

Martin says commercial breeding companies are clamoring for these capabilities.

"We had industry partners on the study who definitely want to use this in the years to come. And they made very good, important contributions. They wanted to make sure the answers were relevant for breeders in the field making decisions, selecting plants, and for farmers," Martin says. "Finding a good method to help breeders actually make decisions on large scales is quite exciting."

Just like other organisms, plants must respond dynamically to a variety of cues over their lifetime. Going through different developmental stages, or altering their form in response to a drought or drastic temperature change requires altering which of their genes are expressed into proteins and when those processes occur.

In a new paper in Developmental Cell, a research team led by Penn biologists Brian Gregory and Xiang Yu identified a mechanism by which plants can conduct this agile regulation of gene expression. They unpacked the details of a process whereby hormone signaling triggers the removal of a structure called nicotinamide adenine dinucleotide (NAD+) from one end, called the 5' end, of certain messenger RNA (mRNA) molecules, the transcripts that give rise to proteins. When present, these caps direct the cell to break down the associated mRNA transcript, ensuring that its corresponding protein is not made.

"We saw changes in the level of mRNA NAD+ capping occurring in different plant tissues and in different developmental stages," says Gregory, senior author on the paper and an associate professor in the School of Arts & Sciences' Department of Biology. "This appears to be a potentially quick on/off switch that plants can use to regulate their RNA levels."

"Researchers working on mammalian cells had identified an enzyme that appears to perform an analogous action, removing these NAD+ caps," says Yu, a postdoctoral researcher in Greogry's lab and the paper's first author. "Ours is the first study to show this process in a whole, living organism."

This work has its origins in preliminary findings that Gregory's lab generated close to a decade ago. While teaching a class on RNA, Gregory had shared with his students a paper about a yeast version of the plant protein DX01, an enzyme now known to be responsible for removing NAD+ from mRNA.

"I became really intrigued about what it was doing in eurkaryotes," he says. At that time, his lab grew plants with a DX01 mutation and found that their growth was stunted, their leaves were pale green, their development was delayed, and they had defects in fertility.

"I thought, 'This is cool, we need to work on this,'" Gregory recalls.

Pursuing it, they found that the mutants had an abundance of small RNAs, molecules often associated with silencing the expression of other RNA molecules. But ultimately they couldn't piece together a sensible story of how the mutation was causing small RNAs to accumulate, and the work stalled.

It stalled that is, until a few years ago, when other scientists who work on mammalian RNA regulation began publishing work showing that mammalian cells possess DX01 as well, and that it could recognize and remove NAD+ caps.

With this new understanding of DX01's role, Gregory, Yu, and colleagues decided to pick their own work back up. By studying plants, the group could take the findings in mammals a step further, looking in vivo, at how the enzyme was acting in a live, growing organism.

The researchers first confirmed that DX01 acted similarly in plants as in mammals, removing the NAD+ from mRNA transcripts. Plants lacking DX01 developed the problems Gregory had seen years earlier: stunted growth and development. They also used a technique to isolate and sequence only the NAD+-capped mRNAs and found that mRNA transcripts with NAD+ caps occurred frequently for those encoding proteins related to stress response, as well as those involved in processing NAD+ itself. Further analysis confirmed that the NAD+ cap made mRNAs more likely to be broken down.

To follow up on the clues pointing to an involvement in stress response, the team applied varying levels of a plant stress hormone, abscisic acid, to plants with or without a functioning DX01. Plants with a mutant DX01 did not appear to be affected by the changing hormone concentration, while those with a functional DX01 were, pointing to a role for NAD+ capping in responding to this hormone.

And indeed, they found that the level of NAD+ capping of RNA in response to abscisic acid dynamically changed.

"It does look like NAD+ capping is tissue-specific and responds to at least one specific physiological cue," says Gregory, "at least in plants. That's pretty neat becaue it looks like it's a strong regulator of RNA stability, so the plant can destabilize different sets of mRNA transcripts, depending on where this process is acting and what cue is being given."

The group's findings even tied back to the unusual discovery they had made much earlier, of a build-up of small RNA molecules. In their DX01 mutant plants, they observed that the NAD+ capped mRNA transcripts were processed into small RNAs, which are also unstable. Gregory, Yu, and colleagues believe this may be a secondary mechanism to remove NAD+ and rid themselves of these noncanonically capped transcripts, even in the absence of DX01.

"What's going on is they're using another pathway, making small RNAs, perhaps to get back the NAD+ so they can use it for other processes," Yu says.

Indeed, NAD+ is a critical component in metabolism, so it makes sense that plants would have multiple strategies for ensuring they have enough available to them, the researchers say.

In future work, the Gregory lab hopes to continue exploring the NAD+ mark, including working out how it is added and not just removed.

"Once we learn how to add, recognize, and remove it, it gives us the power to use this process as a tool for regulating various responses in plants," Gregory says, a power that could possibly be used in agriculture.

But human health could benefit from these insights as well. The Penn researchers say that the work deserves follow-up in mammalian systems. "I'd be curious to see what types of mRNA transcripts in mammals respond to different hormones," says Gregory.

Addition and removal of the NAD+ cap may even be involved in cancer biology, Gregory and Yu say. The abnormal cell metabolism seen in cancer cells often owes to mishaps in the type of regulation that mRNA transcripts undergo, and there's a "real probability," Gregory says, that NAD+ capping and decapping could play a role.

For his part, Gregory is pleased to have been able to move forward with an area of research that eluded him years ago, one that is opening up a new area of study for his lab.

"This is definitely one of those stories that reminds me that science is not a sprint; it's a marathon," Gregory says.

Michael Gross, professor of chemistry in Arts & Sciences at Washington University in St. Louis and of immunology and internal medicine at the School of Medicine, and his team are experts in footprinting proteins -- that is, using advanced methods for investigating the structure and interactions of proteins within larger molecules.

By sharing their method for fast photochemical oxidation of proteins (FPOP), a means of protein footprinting, they hope to support other labs in developing broader applications of FPOP to better address outstanding questions in structural biology.

"FPOP has drawn significant attention because it complements existing footprinting," said Roger Liu, a graduate student working with Gross and first author of a new publication about protein footprinting in the journal Nature Protocols. "Its major advantages include fast labeling time frame, irreversible nature, high sensitivity and relatively broad amino acid residue coverage."

Despite the compelling advantages of FPOP, the technical difficulty of establishing the platform has caused a lag in broader applications. Liu cites challenges including choosing the proper laser, setting up the laser optics, establishing the flow system, acquiring the footprint and analyzing the results by mass spectrometry.

"We always thought that the best way to disseminate FPOP is by applications," Gross said. "Following its discovery, we have implemented it for problems in biochemistry and biophysics."

Fast protein folding could be beneficial for mapping epitopes, which are the parts of an antigen that are recognized by the immune system. This application is potentially important for scientists and medical professionals racing to address the COVID-19 pandemic.

Other applications could include understanding aggregating proteins, with implications in Alzheimer's disease; uncovering hidden conformational changes invisible to other structural methods; and determining binding sites and binding affinities of small molecules that bind to proteins.

Gross added: "Currently, in a collaboration with Weikai Li in the Department of Biochemistry and Molecular Biophysics, we are moving into transmembrane and membrane-associated proteins where new structural methods are desperately needed for this important class of proteins."

A new 5-month longitudinal analysis of 254 COVID-19 patients who displayed a wide range of disease severity - from asymptomatic to deadly illness - suggests that IgA and IgM antibodies to the SARS-CoV-2 virus disappear quickly during convalescence. IgG antibodies likely persist for longer, but Katharina Röltgen and colleagues nonetheless documented a slow, inexorable decline in this antibody class as well, even in severely ill patients who mounted very strong initial antibody responses. Studying 983 plasma samples collected up to 5 months post-infection from 79 hospitalized COVID-19 patients and 175 outpatients and asymptomatic people infected with SARS-CoV-2, Röltgen et al. found a higher ratio of antibodies that react to the viral spike protein complex (versus those that target the nucleocapsid protein) in patients with mild illness compared with the severely ill patients, suggesting that this preponderance of spike-reactive antibodies may have helped to blunt the severity of symptoms. To facilitate their work, the researchers also developed an immunoassay that can detect successful blocking of the viral receptor binding domain's interaction with the human ACE2 receptor in human samples, providing an effective surrogate for detecting neutralizing antibodies. The authors say their findings may raise important questions about the reliability of seroprevalence studies, since the rapid waning of antibody titers may lead to an underestimation of how many people may have been previously infected in a given population. "The decrease in antibodies after infection also raises the question of how long antibodies elicited by vaccination will last, and whether frequent boosting will be needed to maintain protection," the authors further note.

An Asian hornet sets its sights on a busy honey bee hive. If all goes according to plan, the hornet's attack will result in a haul of bee larvae, precious nourishment to pilfer and feed to its own hornet young.

But over time, predator-prey evolution has equipped some honey bees with a potent defense mechanism against such an attack. A signal from colony guard bees lets hornets know that their attack plans have been exposed, and also sends an alarm across the bee colony communicating that urgent reinforcements are needed due to the impending danger. This "I see you" (ISY) visual signal involves guard bees shaking their abdomens laterally and increases as the threat intensifies.

Hornets are ferocious bee predators that have invaded multiple countries around the world. Yet even the giant "murder" hornets that have generated much concern of late have come to recognize the ISY signal as a warning to back off. They are well aware that ISY can lead to a counter attack in which a mass of bees surrounds the hornet, forming a "heat ball" with a deadly mix of heat, carbon dioxide and stinging for the hornet inside.

University of California San Diego biologists studying Asian honey bees (Apis cerana) and hornets (Vespa velutina) have produced new research that deconstructs this ISY signal and shows for the first time that it is visually driven and contagious across the bee colony. The findings are described Dec. 7, 2020 in the Journal of Animal Ecology. A key point of the new study is that the bees can only succeed if they have sufficient numbers to effectively execute a heat ball.

"The beauty of the ISY signal is that hornets are only deterred if enough defending bees quickly gather to synchronously produce the signal, thereby showing the hornet that further attack is futile," said study senior author James Nieh, a professor in the Section of Ecology, Behavior and Evolution in UC San Diego's Division of Biological Sciences.

But how to gather this defense? Nieh says the ISY signal is contagious and attracts other defenders who immediately copy the signal and rush towards the signaler, even if they cannot directly see or sense the predator.

"Hornets give off smell and sound but we found that the visual of a hornet alone can elicit the signal, which was not known," said Nieh. Previous speculation held that guard bees might produce a pheromone to alert others in the colony of the impending danger. "Using just a contagious visual signal is better because guards who are too far away to smell or hear the hornet can immediately head towards the threat. In some ways, it's like a fast chain reaction," said Nieh.

Nieh says the concept links to the issue of "fake news" since animal communication often contains errors, and a false ISY alarm could rapidly spread within the colony.

One solution to the problem of false information spread is that the bees are very selective about what they consider a true threat. Using an iPad to display videos, researchers Shihao Dong, Ken Tan and Nieh found that the visual appearance and motion of the hornet alone could trigger ISY signals. Visual displays of a harmless butterfly, on the other hand, elicited no response. The second and most important safeguard against false reporting is that bees are even more choosy about what they consider to be a real ISY signal.

"We played back videos of bees performing ISY signals at different speeds, but only the correct bee image at the right speed caused other bees to respond. This helps keep the signal spread honest," said Nieh.

It is still true that a bee could occasionally "cry wolf" but Nieh thinks that evolution has limited these errors because nestmates must work together to fight these powerful predators and colonies prone to errors would suffer. Nieh and his colleagues are now testing the details of the visual cues behind ISY. They are developing animations that display related visuals that can be tested, such as whether a harmless butterfly can be depicted as threatening, or whether offshoots such as a hornet displayed without wings could be enough to trigger ISY.

Nieh believes that the findings provide a cautionary tale about fake news for all of us.

"Individuals in a honey bee colony are completely interdependent. They can't go out and make it on their own. Cooperation is paramount, especially when faced with a large, heavily armored predator like hornets," said Nieh. "A couple of hornets can kill thousands of bees in a single day. Yet through teamwork that correctly produces synchronized, massed ISY signals, they can get the hornet to back off without harming a single bee. Maybe that's a lesson for us all."