China’s first emperor broke the mold when he had himself buried with a terra-cotta army. Now insight into the careful crafting of those soldiers is coming from the clays used to build them. Custom clay pastes were mixed at a clay-making center and then distributed to specialized workshops that cranked out thousands of the life-size figures, new research suggests.

Roughly 700,000 craftsmen and laborers built Emperor Qin Shihuang’s palatial mausoleum in east-central China between 247 B.C. and 210 B.C. A portion of those workers gathered clay from nearby deposits and prepared it in at least three forms, researchers propose in the August Antiquity. On-site or nearby workshops used different signature clay recipes for terra-cotta warriors, parts of mostly bronze waterfowl figures and paving bricks for pits in which the soldiers originally stood.
Around 7,000 ceramic foot soldiers, generals and horses — equipped with a variety of bronze weapons — make up the army, which was accidentally discovered in 1974 by farmers digging a well. The emperor would have regarded the ceramic statues as a magic army that would protect him as he ruled in the afterlife, many researchers suspect.

Building and assembling the multitude was an enormous task. Workers poured clay mixtures into casts of torsos, limbs and other body parts, and then assembled the bodies, taking care to create different facial features for each soldier. Finished statues, now mostly gray, were covered in colored lacquers and likely fired in kilns. Most figures were placed inside one giant pit. Earthen walls formed 11 parallel corridors where statues stood in battle-ready rows.

Still, no workshops or debris firmly linked to the statue-making process have been found. As a result, the number, size, location and organization of workshops involved in producing the emperor’s ceramic troops remain uncertain.

Archaeologist Patrick Quinn of University College London and three Chinese colleagues studied the composition of clay samples from the site. The pieces were taken from 12 terra-cotta warriors, two acrobat statues found in a second pit, five clay bricks from the floor of the largest pit, clay fragments from inside three bronze waterfowl statues found in a third pit and part of an earthen wall in the acrobat pit.

Microscopic analysis of the samples revealed that the clay came from deposits near the tomb’s location, the scientists say. But the recipes for different parts varied. Paving bricks contained only a mixture of dark and light clays, while the clay used for warriors and acrobats had sand worked in. Sand and plant fragments were folded into a clay mixture that formed the core of the bronze waterfowl.
Sand may have made the clay more malleable for shaping into ornate figures and increased statues’ durability, the researchers speculate. Plant pieces may have helped reduce the weight of birds’ clay cores. A clay-processing site at or just outside the emperor’s mausoleum must have doled out the appropriate clay pastes to an array of workshops where potters made statues, bricks or other objects, the scientists propose.

What’s more, many statue and waterfowl samples show signs of having been slowly heated in kilns at maximum temperatures of no more than 750˚ Celsius. That’s lower by 150˚ C or more than some previous estimates, the investigators say. Fires set in an attack on the tomb after the emperor’s death may have refired some of the clay, accounting for the temperature discrepancy, the researchers say.

“I’m not at all surprised by the new findings,” says East Asian art historian Robin D.S. Yates of McGill University in Montreal. Legal and administrative documents previously found at two other Qin Empire sites describe workshops that specialized in various types of craft production, Yates says.

In some cases, artisans’ stamps and inscriptions on terra-cotta warriors match those on excavated roof tiles from Emperor Qin’s mausoleum. The markings suggest that some workshops made several types of ceramic objects, says East Asian art historian Lothar Ledderose of Heidelberg University in Germany. Inscriptions on statues also indicate that artisans working at off-site factories during the Qin Empire collaborated with potters at local workshops to produce the terra-cotta army, Ledderose says.

Early in Inferior, science writer Angela Saini recalls a man cornering her after a signing for her book Geek Nation, on science in India. “Where are all the women scientists?” he asked, then answered his own question. “Women just aren’t as good at science as men are. They’ve been shown to be less intelligent.”

Saini fought back with a few statistics on girls’ math abilities, but soon decided that nothing she could say would convince him. It’s a situation that may feel familiar to many women. “What I wish I had was a set of scientific arguments in my armory,” she writes.
So she decided to learn the truth about what science really does tell us about differences between the sexes. “For everyone who has faced the same situation,” she writes, “the same desperate attempt to not lose control but have at hand some real facts and a history to explain them, here they are.”

In Inferior, Saini marshals plenty of facts and statistics contradicting sexist notions about women’s bodies and minds. She cites study after study showing little or no difference in male and female capabilities.

But it’s the book’s historical perspective that makes it most compelling. Only by understanding the cultural context of the men whose studies and ideas first pointed to gender imbalances can we see how deeply biases run, Saini argues.

Charles Darwin’s influential ideas reflected his times, for instance. In The Descent of Man, he wrote that “man has ultimately become superior to woman” via evolution. To a woman active in her local women’s movement, Darwin wrote, “there seems to me to be a great difficulty from the laws of inheritance … in [women] becoming the intellectual equals of man.”

If that idea sounds absurd now, don’t fool yourself into thinking it has vanished. Saini’s book is full of examples right up to today of scientists who have started from this and other flawed premises, which have led to generations of flawed studies and results that reinforce stereotypes. But the tide has been turning, as more women have entered science and more scientists of both sexes seek to remove bias from their work.
Saini does an excellent job of dissecting research on evolution, neuroscience and even the long-standing notion that women’s sexual behavior is driven by their interest in stable, monogamous relationships. By the end, it’s clear that science doesn’t divide men and women; we’ve done that to ourselves. And as scientists become more rigorous, we get closer to seeing ourselves as we really are.

A tiny, shimmying cantilever wiggles a bit more than expected in a new experiment. The excess jiggling of the miniature, diving board–like structure might hint at why the strange rules of quantum mechanics don’t apply in the familiar, “classical” world. But that potential hint is still a long shot: Other sources of vibration are yet to be fully ruled out, so more experiments are needed.

Quantum particles can occupy more than one place at the same time, a condition known as a superposition (SN: 11/20/10, p. 15). Only once a particle’s position is measured does its location become definite. In quantum terminology, the particle’s wave function, which characterizes the spreading of the particle, collapses to a single location (SN Online: 5/26/14).
In contrast, larger objects are always found in one place. “We never see a table or chair in a quantum superposition,” says theoretical physicist Angelo Bassi of the University of Trieste in Italy, a coauthor of the study, to appear in Physical Review Letters. But standard quantum mechanics doesn’t fully explain why large objects don’t exist in superpositions, or how and why wave functions collapse.

Extensions to standard quantum theory can alleviate these conundrums by assuming that wave functions collapse spontaneously, at random intervals. For larger objects, that collapse happens more quickly, meaning that on human scales objects don’t show up in two places at once.

Now, scientists have tested one such theory by looking for one of its predictions: a minuscule jitter, or “noise,” imparted by the random nature of wave function collapse. The scientists looked for this jitter in a miniature cantilever, half a millimeter long. After cooling the cantilever and isolating it to reduce external sources of vibration, the researchers found that an unexplained trembling still remained.

In 2007, physicist Stephen Adler of the Institute for Advanced Study in Princeton, N.J., predicted that the level of jitter from wave function collapse would be large enough to spot in experiments like this one. The new measurement is consistent with Adler’s prediction. “That’s the interesting fact, that the noise matches these predictions,” says study coauthor Andrea Vinante, formerly of the Institute for Photonics and Nanotechnologies in Trento, Italy. But, he says, he wouldn’t bet on the source being wave function collapse. “It is much more likely that it’s some not very well understood effect in the experiment.” In future experiments, the scientists plan to change the design of the cantilever to attempt to isolate the vibration’s source.

The result follows similar tests performed with the LISA Pathfinder spacecraft, which was built as a test-bed for gravitational wave detection techniques. Two different studies found no excess jiggling of free-falling weights within the spacecraft. But the new cantilever experiment tests for wave function collapse occurring at different rate and length scales than those previous studies.
Theories that include spontaneous wave function collapse are not yet accepted by most physicists. But interest in them has recently become more widespread, says physicist David Vitali of the University of Camerino in Italy, “sparked by the fact that technological advances now make fundamental tests of quantum mechanics much easier to conceive.” Focusing on a simple system like the cantilever is the right approach, says Vitali, who was not involved with the research. Still, “a lot of things can go wrong or can be not fully controlled.”

To conclude that wave function collapse is the cause of the excess vibrations, every other possible source will have to be ruled out. So, Adler says, “it’s going to take a lot of confirmation to check that this is a real effect.”

Air pollution is a drag for renewable energy. Dust and other sky-darkening air pollutants slash solar energy production by 17 to 25 percent across parts of India, China and the Arabian Peninsula, a new study estimates. The haze can block sunlight from reaching solar panels. And if the particles land on a panel’s flat surface, they cut down on the area exposed to the sun. Dust can come from natural sources, but the other pollutants have human-made origins, including cars, factories and coal-fired power plants.

Scientists collected and analyzed dust and pollution particles from solar panels in India, then extrapolated to quantify the impact on solar energy output in all three locations. China, which generates more solar energy than any other country, is losing up to 11 gigawatts of power capacity due to air pollution, the researchers report in the Aug. 8 Environmental Science & Technology Letters. That’s a loss of about $10 billion per year in U.S. energy costs, says study coauthor Mike Bergin of Duke University. Regular cleaning of solar panels can help. Cleaning the air, however, is harder.

Pregnant women who do not have enough folic acid — a B vitamin — in their bodies can pass the deficiency on to their unborn children. It may lead to retarded growth and congenital malformation, according to Dr. A. Leonard Luhby…. “Folic acid deficiency in pregnant women could well constitute a public health problem of dimensions we have not originally recognized,” he says. — Science News. December 9, 1967

Update
Folic acid — or folate — can prevent brain and spinal cord defects in developing fetuses. Since the U.S. Food and Drug Administration required that all enriched grain products contain the vitamin starting in 1998, birth defects have been prevented in about 1,300 babies each year. But some women still don’t get enough folate, while others may be overdoing it. About 10 percent of women may ingest more than the upper limit of 1,000 micrograms daily — about 2.5 times the recommended amount, a 2011 study found. Too much folate may increase a woman’s risk for certain cancers and interfere with some epilepsy drugs.

Immediately after a 19-year-old shot and killed 17 people and wounded 17 others at a Florida high school on Valentine’s Day, people leaped to explain what had caused the latest mass slaughter.

By now, it’s a familiar drill: Too many readily available guns. Too much untreated mental illness. Too much warped masculinity. Don’t forget those shoot-’em-up video games and movies. Add (or repeat, with voice raised) your own favorite here.

Now the national debate has received an invigorated dose of activism. Inspired by students from the targeted Florida high school, as many as 500,000 people are expected to rally against gun violence and in favor of stricter gun laws on March 24 in Washington, D.C., with sister marches taking place in cities across the world. But a big problem haunts the justifiable outrage over massacres of innocents going about their daily affairs: Whatever we think we know about school shootings, or mass public shootings in general, is either sheer speculation or wrong. A science of mass shootings doesn’t exist.

“There is little good research on what are probably a host of problems contributing to mass violence,” says criminologist Grant Duwe of the Minnesota Department of Corrections in St. Paul. Duwe has spent more than two decades combing through federal crime records and newspaper accounts to track trends in mass killings.
Perhaps this dearth of data is no surprise. Research on any kind of gun violence gets little federal funding (SN Online: 3/9/18; SN: 5/14/16, p. 16). Criminologist James Alan Fox of Northeastern University in Boston has argued for more than 20 years that crime researchers mostly ignore mass shootings. Some of these researchers assume that whatever causes people to commit any form of murder explains mass shootings. Others regard mass killings as driven by severe mental disorders, thus falling outside the realm of crime studies.

When a research vacuum on a matter of public safety meets a 24-hour news cycle juiced up on national anguish, a thousand speculations bloom. “Everybody’s an expert on this issue, but we’re relying on anecdotes,” says sociologist Michael Rocque of Bates College in Lewiston, Maine.

Rocque and Duwe published a review of what’s known about reasons for mass public shootings, sometimes called rampage shootings, in the February Current Opinion in Psychology. Their conclusion: not much. Scientific ignorance on this issue is especially concerning given that Rocque and Duwe describe a slight, but not unprecedented, recent uptick in the national rate of rampage shootings.
Shooting stats
Defining mass public shootings to track their frequency is tricky. A consensus among researchers is emerging that these events occur in public places, include at least four people killed by gunshots within a 24-hour period and are not part of a robbery or any other separate crime, Rocque and Duwe say. Such incidents include workplace and school shootings.
Overall, mass public shootings are rare, Duwe says, though intense media coverage may suggest the opposite. Even less obvious is that rampage shootings have been occurring for at least 100 years.

Using Federal Bureau of Investigation homicide reports, Congressional Research Service data on mass shootings and online archives of news accounts about multiple murders, Duwe has tracked U.S. rates of mass public shootings from 1915 to 2017.

He has identified a total of 185 such events through 2017, 150 of which have occurred since 1966. (In 2016, he published results up to 2013 in the Wiley Handbook of the Psychology of Mass Shootings.) In the earliest known case, from 1915, a Georgia man shot five people dead in the street, after killing an attorney he blamed for financial losses, and wounded 32 others. Another lawyer, who came to the crime scene upon hearing gunshots and was wounded by a bullet, ended the rampage when he grabbed a pistol from a hardware store and killed the shooter.

What stands out more than a century later is that, contrary to popular opinion, mass public shooting rates have not ballooned to record highs. While the average rate of these crimes has increased since 2005, it’s currently no greater than rates for some earlier periods. Crime trends are usually calculated as rates per 100,000 people for, say, robberies and assaults. But because of the small number of mass public shootings, Duwe calculates annual rates per 100 million people in the United States.

The average annual rate of mass public shootings since 2010 is about 1.44 per 100 million people. That roughly equals the 1990s rate of 1.41, Duwe finds.

The average annual rate from 1988 to 1993 reached 1.52, about the same as the 1.51 rate from 2007 to 2012. After dropping to just below 1 per 100 million people in 2013 and 2014, rates increased to nearly 1.3 the next three years.

From 1994 to 2004, rates mostly hovered around 1 per 100 million people or below, but spiked to over 2.5 in 1999. That’s the year two teens killed 13 people at Columbine High School in Colorado.

In contrast, rates were minuscule from 1950 to 1965, when only three mass public shootings were recorded. The average annual rate for 1970 to 1979 reached 0.52, based on 13 mass public shootings.

Numbers of people killed and wounded per shooting incident have risen in the last decade, though. Two events in 2012 were particularly horrific. Shootings at a movie theater in Aurora, Colo., and an elementary school in Newtown, Conn., resulted in 40 murders, many of children, and 60 nonfatal gunshot wounds. Whether this trend reflects an increasing use of guns with large-capacity magazines or other factors “is up for grabs,” Duwe says.
The unknowns
No good evidence exists that either limiting or loosening gun access would reduce mass shootings, Rocque says. Virtually no research has examined whether a federal ban on assault weapons from 1994 to 2004 contributed to the relatively low rate of mass public shootings during that period. The same questions apply to concealed-carry laws, promoted as a way to deter rampage killers. As a gun owner and longtime hunter in his home state of Maine, Rocque calls for “an evidence-based movement” to establish links between gun laws and trends in mass shootings.

Mental illness also demands closer scrutiny, Duwe says. Of 160 mass public shooters from 1915 to 2013, about 60 percent had been assigned a psychiatric diagnosis or had shown signs of serious mental illness before the attack, Duwe has found. In general, mental illness is not linked to becoming violent. But, he says, many mass shooters are tormented and paranoid individuals who want to end their painful lives after evening the score with those they feel have wronged them.

Masculinity also regularly gets raised as a contributor to mass public shootings. It’s a plausible idea, since males committed all but one of the tragedies in Duwe’s review. Sociologist Michael Kimmel of Stony Brook University in New York contends that a sense of wounded masculinity as a result of various life failures inspires rage and even violence. But researchers have yet to examine how any facet of masculinity plays into school or workplace shootings, Rocque says.

Although school shooters often report feeling a desperate need to make up for having been inadequate as men, many factors contribute to their actions, argues clinical psychologist Peter Langman. Based in Allentown, Pa., Langman has interviewed and profiled several dozen school shooters in the United States and other countries.
He divides perpetrators into three psychological categories: psychopathic (lacking empathy and concern for others), psychotic (experiencing paranoid delusions, hearing voices and having poor social skills) and traumatized (coming from families marked by drug addiction, sexual abuse and other severe problems).

But only a few of the millions of people who qualify for those categories translate their personal demons into killing sprees. Any formula to tag mass shooters in the making will inevitably round up lots of people who would never pose a deadly threat.

“There is no good evidence on what differentiates a bitter, aggrieved man from a bitter, aggrieved and dangerous man,” says psychologist Benjamin Winegard of Carroll College in Helena, Mont.

Nor does any published evidence support claims that being a bully or a victim of bullying, or watching violent video games and movies, leads to mass public shootings, Winegard contends. Bullying affects a disturbingly high proportion of youngsters and has been linked to later anxiety and depression (SN: 5/30/15, p. 12) but not to later violence. In laboratory studies, youngsters who play violent computer games or watch violent videos generally don’t become more aggressive or violent in experimental situations. Investigators have found that some school shooters, including the Newtown perpetrator, preferred playing nonviolent video games, Winegard says.

He and a colleague presented this evidence in the Wiley Handbook of the Psychology of Mass Shootings. Northeastern’s Fox also coauthored a chapter in that publication.

Still, a small but tragic group of kids lead lives that somehow turn them into killers of classmates or random strangers (SN: 5/27/06, p. 328). If some precise mix of, say, early brain damage, social ineptitude, paranoia and fury over life’s unfair twists cooks up mass killers, scientists don’t know the toxic recipe. And it won’t be easy to come up with one given the small number of mass public shooters to study.

Duwe recommends that researchers first do a better job of documenting the backgrounds of individual mass shooters and any events or experiences that may have precipitated their deadly actions. Then investigators can address broader social influences on mass shootings, including gun legislation and media coverage.

But more than a century after a distraught Georgia man mowed down six of his fellow citizens, research on mass violence still takes a backseat to public fear and outrage. “If we’re bemoaning the state of research,” Duwe says, “we have no one to blame but ourselves.”

Slow-motion large land snails made for easy catching and good eating as early as 170,000 years ago.

Until now, the oldest evidence of Homo sapiens eating land snails dated to roughly 49,000 years ago in Africa and 36,000 years ago in Europe. But tens of thousands of years earlier, people at a southern African rock-shelter roasted these slimy, chewy — and nutritious — creepers that can grow as big as an adult’s hand, researchers report in the April 15 Quaternary Science Reviews.
Analyses of shell fragments excavated at South Africa’s Border Cave indicate that hunter-gatherers who periodically occupied the site heated large African land snails on embers and then presumably ate them, say chemist Marine Wojcieszak and colleagues. Wojcieszak, of the Royal Institute for Cultural Heritage in Brussels, studies chemical properties of archaeological sites and artifacts.

The supersized delicacy became especially popular between about 160,000 and 70,000 years ago, the researchers say. Numbers of unearthed snail shell pieces were substantially larger in sediment layers dating to that time period.

New discoveries at Border Cave challenge an influential idea that human groups did not make land snails and other small game a big part of their diet until the last Ice Age waned around 15,000 to 10,000 years ago, Wojcieszak says.

Long before that, hunter-gatherer groups in southern Africa roamed the countryside collecting large land snails to bring back to Border Cave for themselves and to share with others, the team contends. Some of the group members who stayed behind on snail-gathering forays may have had limited mobility due to age or injury, the researchers suspect.

“The easy-to-eat, fatty protein of snails would have been an important food for the elderly and small children, who are less able to chew hard foods,” Wojcieszak says. “Food sharing [at Border Cave] shows that cooperative social behavior was in place from the dawn of our species.”

Border Cave’s ancient snail scarfers also push back the human consumption of mollusks by several thousand years, says archaeologist Antonieta Jerardino of the University of South Africa in Pretoria. Previous excavations at a cave on South Africa’s southern tip found evidence of humans eating mussels, limpets and other marine mollusks as early as around 164,000 years ago (SN: 7/29/11).

Given the nutritional value of large land snails, an earlier argument that it was eating fish and shellfish that energized human brain evolution may have been overstated, says Jerardino, who did not participate in the new study.
It’s not surprising that ancient H. sapiens recognized the nutritional value of land snails and occasionally cooked and ate them by 170,000 years ago, says Teresa Steele, an archaeologist at the University of California, Davis who was not part of the work. But intensive consumption of these snails starting around 160,000 years ago is unexpected and raises questions about whether climate and habitat changes may have reduced the availability of other foods, Steele says.

Researchers have already found evidence that ancient people at Border Cave cooked starchy plant stems, ate an array of fruits and hunted small and large animals. The oldest known grass bedding, from around 200,000 years ago, has also been unearthed at Border Cave (SN: 8/13/20).

Several excavations have been conducted at the site since 1934. Three archaeologists on the new study — Lucinda Backwell and Lyn Wadley of Wits University in Johannesburg and Francesco d’Errico of the University of Bordeaux in France — directed the latest Border Cave dig, which ran from 2015 through 2019.

Discoveries by that team inspired the new investigation. Excavations uncovered shell fragments of large land snails, many discolored from possible burning, in all but the oldest sediment layers containing remnants of campfires and other H. sapiens activity. The oldest layers date to at least 227,000 years ago.

Chemical and microscopic characteristics of 27 snail shell fragments from various sediment layers were compared with shell fragments of modern large African snails that were heated in a metal furnace. Experimental temperatures ranged from 200° to 550° Celsius. Heating times lasted from five minutes to 36 hours.

All but a few ancient shell pieces displayed signs of extended heat exposure consistent with having once been attached to snails that were cooked on hot embers. Heating clues on shell surfaces included microscopic cracks and a dull finish.

Only lower parts of large land snail shells would have rested against embers during cooking, possibly explaining the mix of burned and unburned shell fragments unearthed at Border Cave, the researchers say.

Black holes have been beguiling from the very beginning.

Hinted at as early as the 1780s and predicted by Einstein’s general theory of relativity, they didn’t get the name we know today until the 1960s. Bizarre beasts that squash gobs of matter into infinitely dense abysses, black holes were once thought to be merely a mathematical curiosity.

But astronomers tallied up evidence for black holes’ existence bit by bit, puzzling over where these behemoths live, how they gulp down matter and what their existence means for other physics theories.

For more than a decade, a team of researchers has been engrossed in an ambitious effort to snap a picture of a black hole for the very first time. And now they’ve done it. What better time to think back to black holes’ origins and the journey so far?

A surprise ingredient may explain how lemon juice puts the squeeze on kidney stones.

Lemons contain nanoparticles that, when fed to rats, block stone formation, scientists report in the Feb. 22 Nano Letters. If the tiny sacs do the same for humans, the nanoparticles might one day offer a way to prevent kidney stones in people, says pharmaceutical scientist Hongzhi Qiao of Nanjing University of Chinese Medicine.

Lemon juice is a well-known home remedy for kidney stones, which form when minerals crystalize and clump up inside the kidney (SN: 9/21/18). These rocky lumps can knock around in the urinary tract, slicing and dicing tissues as they eventually pass out of the body (SN: 10/31/16). “It’s so, so, so painful,” says Jingyin Yan, a nephrologist at Baylor College of Medicine in Houston who was not part of the new study. Patients may feel sharp pain in their back, side or lower abdomen when they pass a stone, she says. “People describe it as worse than delivering a baby.”
Though some medications can help treat kidney stones, many people end up needing surgery to remove them, says Thomas Chi, a urologist at the University of California, San Francisco, also not part of the study. People often imagine kidney stones as tiny pebbles, but sometimes they bulk up like boulders, he adds. “I’ve taken out stones the size of your fist.”

That’s why prevention is key. Scientists already knew that citric acid, which gives lemons their sour power, may do the trick by binding to the minerals that make up stones. But drinking mouth-puckering lemon juice is not so comfortable for patients, Qiao says.

A 2022 clinical trial found that kidney stone patients had trouble downing 120 milliliters — about a half cup — of lemon juice per day. Swilling loads of lemonade can cause dental problems, too. Chi has had patients drink so much that the acidic liquid ate away at their teeth.

So Qiao and colleagues looked for other, more palatable lemon-derived ingredients that might help prevent kidney stones. Inside edible and medicinal plants like ginseng, grapefruit and dandelion, his team has found extracellular vesicle-like nanoparticles, tiny sacs stuffed with molecules including fat, protein and DNA.
These nanoparticles exist in lemon juice, too­­ — and the team fed them to rats that had also ingested a substance that promotes kidney stone growth. The zesty particles slowed stone formation, Qiao and colleagues found. The finding suggests these particles curb development of calcium oxalate crystals, the most common culprit of kidney stones. The particles can also soften the stones and make them less sticky, the team showed.

The new work challenges the conventional wisdom on how lemon juice works to combat kidney stones, Chi says. Using lemon nanoparticles to treat people is still a long way off, but the team’s results hold promise, he says. “The faster you can bring a finding like this towards a human clinical trial, the better.”