What may be the oldest known solid cheese has been found in an ancient Egyptian tomb.
Made from a mixture of cow milk and either sheep or goat milk, the cheese filled a broken clay jar unearthed from a 13th century B.C. tomb for Ptahmes, the mayor of the ancient city of Memphis, researchers report online July 25 in Analytical Chemistry.
Chemist Enrico Greco, who did the work while at the University of Catania in Italy, and colleagues used mass spectrometry to analyze the antique cheese — now a white, soapy lump weighing “several hundred grams.” Besides milk and whey proteins, the cheese contained remnants of bacteria that cause an infection called brucellosis, adding to evidence that ancient Egyptians may have grappled with the disease, Greco says. Cheese making predates the new find by thousands of years, but preserved cheese is hard to come by (SN: 1/26/13, p. 16). Archaeologists found older curds draped around the necks of Bronze Age mummies in China, a different group of researchers reported in 2014 in the Journal of Archaeological Science. “There are other samples of dairy products in the literature, but not solid cheeses in the strict sense,” Greco says.
He says he did not sniff the cheese, but given its degraded state it is unlikely to have an odor, pleasant or not.
Salamanders and lizards can both regrow their tails, but not to equal perfection.
While a regenerated salamander tail closely mimics the original, bone and all, a lizard’s replacement is filled with cartilage and lacks nerve cells. That contrast is due to differences between stem cells in the animals’ spinal cords, researchers report online August 13 in Proceedings of the National Academy of Sciences.
When a salamander loses its tail, neural stem cells in the creature’s spinal cord can develop into any type of nervous system cell, including nerve cells, or neurons. But through evolution, lizard neural stem cells “have lost this ability,” says study coauthor Thomas Lozito, a biologist at the University of Pittsburgh. Lizards, while they can regrow cartilage and skin, cannot regenerate neurons, the researchers found. Lozito and colleagues studied neural stem cells from the axolotl salamander (Ambystoma mexicanum) and from two lizard species — the green anole (Anolis carolinensis) and the mourning gecko (Lepidodactylus lugubris). The team also wondered if the lizard stem cells themselves weren’t capable of developing into neurons or if there was something about the environment of the lizard tail that prevented their regrowth. So the researchers implanted salamander neural stem cells into five gecko tail stumps. Some of the cells became neurons in the regrown tails, showing that the lizard stem cells were the problem.
The finding suggests that scientists would have to alter only the lizard stem cells instead of other parts of the tail to regrow a more complete appendage.
How lizards lost their ability to regenerate neurons and salamanders didn’t remains a mystery (SN: 11/28/15, p. 12). Scientists know that species’ places on the evolutionary tree have something to do with organisms’ ability to regrow body parts. “The more complex the species are, the less they can regenerate,” says developmental biologist Katharina Lust of the Research Institute of Molecular Pathology in Vienna, who was not involved in the study. Reptiles such as lizards are more complex organisms than amphibians like salamanders. The researchers plan to use CRISPR/Cas9 gene editing to see if lizard neural stem cells can be modified to regenerate a perfect tail. Ultimately, the team hopes to one day coax stem cells in mammals to regenerate body parts.
“My goal is to make the first mouse that can regenerate its tail,” Lozito says. “We’re kind of using lizards as a stepping-stone.”
The Higgs boson has been spotted bottoming out — but that’s a good thing.
Physicists have detected the elementary particle decaying into two bottom quarks, exotic, short-lived particles that often appear in the aftermath of high-energy particle collisions. The elusive process was finally observed six years after the Higgs boson’s initial discovery, by physicists working at the Large Hadron Collider at CERN in Geneva. Researchers from two LHC experiments, ATLAS and CMS, reported their results simultaneously in a seminar held at CERN on August 28. Scientists don’t detect the Higgs boson directly. Instead, they spot the debris produced when the Higgs disintegrates into less massive particles. The Higgs boson is expected to decay to two bottom quarks more than half of the time. But scientists hadn’t been able to tease out the process until now, because other mechanisms can produce bottom quarks and mimic the Higgs decay (SN: 9/3/16, p. 13). Scientists previously saw the Higgs break down into other types of particles, including particles of light called photons, a process which has fewer issues with Higgs impersonators.
With the Higgs boson’s unveiling in 2012, physicists filled in the last missing piece of the standard model, the theory of the fundamental constituents of matter (SN: 7/28/12, p. 5). But physicists still want to know more about the Higgs’ inner workings.
The standard model makes predictions of how often the Higgs should decay into different types of particles. Bottom quarks are one of six types of quarks in the standard model, each of which has different properties, such as mass and electric charge. While the lightest quarks make up commonplace particles like protons and neutrons, bottom quarks are relatively heavy and rare.
Physicists want to measure the various ways the Higgs boson decays to see if the rates match expectations. If not, that could mean something is wrong with the theory. But the new results upheld the standard model.
Gun deaths occur worldwide, but a new survey reveals the hot spots for those that occur outside of war zones.
In 2016, firearm-related homicides, suicides and accidental deaths were highly concentrated. For example, just six countries — the United States, Brazil, Mexico, Colombia, Venezuela and Guatemala — accounted for about half of the estimated number of gun deaths unrelated to armed conflict, even though the nations together contributed less than 10 percent of the world’s population. That’s just one takeaway from the first look at the global impact of interpersonal and self-inflicted gun violence on public health, published online August 28 in JAMA. Here’s the big picture:
Total global gun deaths rose from 1990 to 2016 Worldwide, an estimated 251,000 people died from guns due to homicide, suicide or unintentional injury in 2016. That’s up from an estimated 209,000 such firearm deaths in 1990, the team found by analyzing data from 195 countries and territories from 1990 to 2016.
In 2016, 64 percent of gun-related deaths were homicides, 27 percent were suicides and 9 percent were accidental deaths. But the rate of gun deaths dipped a bit The researchers looked at the global rate of firearm deaths, adjusted for differences in the distribution of ages in a population. The rate decreased slightly, from 4.2 deaths per 100,000 in 1990 to 3.4 deaths per 100,000 in 2016, because the global population grew.
Even so, “we can see the number of deaths due to gun violence — homicide, suicide, unintentional injury — is very high,” says study coauthor and global health researcher Mohsen Naghavi of the University of Washington in Seattle. “Gun violence is a public health problem.” More gun deaths occur outside of war zones than inside Globally, for every year studied save one, gun deaths due to homicide, suicide and unintentional injury exceeded those due to conflict and terrorism. The exception: 1994, the year of the Rwandan genocide. That year, the death toll from global conflict reached 551,000, compared with 232,000 deaths from gun homicides, suicides and unintentional injuries.
The United States and Brazil are hot spots of gun violence These two countries accounted for 32 percent of the total number of estimated deaths in 2016. In Brazil and the other top four Latin America countries, most gun deaths were homicides. The high rate of gun homicide in these countries is associated with drug and weapon trafficking, research has found. One-fourth of all global gun-related homicides in 2016 took place in Brazil. But in the United States, as in some other wealthy countries, such as France and Germany, suicide accounted for the majority of gun deaths in 2016. Thirty-five percent of all global firearm suicides that year occurred in the United States, the researchers estimate.
Suicide rates have risen across the United States since 1999 (SN: 7/7/18, p. 13). Previous research has shown that having guns in the house is linked to higher use of the weapons to commit suicide and to a larger number of unintentional gun-related deaths.
A new experiment gives rubidium atoms a certain je ne sais quoi.
Scientists arranged individual atoms of the element rubidium into a variety of 3-D shapes, including the Eiffel Tower. The team used a laser to trap atoms in the arrangements, performing a hologram-style technique to encode the complex positions. And moveable, laser-based “tweezers” (SN: 5/12/18, p. 24) shifted atoms that were in the wrong position, researchers from the Institut d’Optique Graduate School in Palaiseau, France, report in the Sept. 6 Nature.
In addition to the Parisian landmark, the researchers sculpted a cone, a doughnut and a Möbius strip — a twisted ring with the unusual property of having only one side (SN Online: 7/24/07). The technique may be helpful for creating atomic quantum computers, which could make calculations by manipulating the interactions between individual atoms (SN: 7/8/17, p. 28).
If Earth’s magnetic field resembles that of a bar magnet, Jupiter’s field looks like someone took a bar magnet, bent it in half and splayed it at both ends.
The field emerges in a broad swath across Jupiter’s northern hemisphere and re-enters the planet both around the south pole and in a concentrated spot just south of the equator, researchers report in the Sept. 6 Nature.
“We were baffled” at the finding, says study coauthor Kimberly Moore, a graduate student at Harvard University. The new look at Jupiter’s magnetic field comes courtesy of NASA’s Juno spacecraft, which has been orbiting the planet since July 2016 (SN: 6/25/16, p. 16). Relying on nearly 2,000 measurements of the field outside the planet, Moore and colleagues created maps detailing how the field emerges by calculating how it extends to roughly 10,000 kilometers below the cloud tops. The results “complicate our picture of Jupiter’s interior,” Moore says. Planetary magnetism arises from electrically conductive fluids within a planet. Typical simulations for how these fluids generate magnetism can explain a field that resembles that of a bar magnet, such as Earth’s or Saturn’s, as well as those that are messy all over, like the ones at Uranus and Neptune. Jupiter’s split personality is harder to explain.
One possibility is that the extreme temperature and pressure near Jupiter’s core create a soup of rock and ice partly dissolved in liquid metallic hydrogen. Here, the interplay of turbulent layers might generate a convoluted magnetic field. Or perhaps squalls of helium rain closer to the clouds stir up conductive layers below, contorting the field before it emerges from the clouds.
To help self-driving cars drive safely, scientists are looking to an unlikely place: the sea.
A new type of camera inspired by the eyes of mantis shrimps could help autonomous vehicles better gauge their surroundings, researchers report October 11 in Optica. The camera — which detects polarized light, or light waves vibrating on a single plane — has roughly half a million sensors that each capture a wide range of light and dark spots within a single frame, somewhat similar to how mantis shrimps see the world. The researchers wanted to “mimic the animals’ ability to detect a wide range of light intensities,” says coauthor Viktor Gruev, a bioengineer at the University of Illinois at Urbana-Champaign. The crustaceans’ visual system allows them to see both light and dark areas while moving in and out of dark crevices in shallow waters, he says.
The newly devised camera can take in a wider range of light intensities, measured in decibels, than other digital or polarization cameras. Previously, the best polarization cameras operated with a dynamic range of about 60 decibels; the new one works within a 140 decibel range, resulting in a clearer mapping of objects in the same frame.
Depending on the maker, autonomous vehicles currently use a mixture of methods to map the world around them, including lidar (light detection and ranging equipment), cameras and GPS. But the cameras currently guiding autonomous vehicles aren’t good at handling sharp lighting transitions and have trouble detecting features in foggy weather (SN: 12/24/16, p. 34). Because the new cameras are small and use many of the same parts as common digital cameras, Gruev says they could cost as little as $10.
From 2007 to 2016, the U.S. Food and Drug Administration flagged nearly 800 over-the-counter dietary supplements as tainted with potentially harmful pharmaceutical drugs, a study shows. Fewer than half of those products were recalled by their makers, scientists found.
Researchers analyzed the FDA’s public database of tainted supplements, identifying both the type of contaminating ingredients they contained and how the products were marketed. Most of these supplements, which are allowed to contain only dietary ingredients, included drugs such as steroids, the active ingredient in Viagra and a weight loss drug banned from the U.S. market eight years ago. The products had been marketed primarily for sexual enhancement, weight loss or muscle building, scientists report online October 12 in JAMA Network Open.
More than half of American adults have reported taking dietary supplements, such as vitamins, minerals and other specialty products. More than 85,000 supplements are estimated to be available in the United States, and the FDA says it cannot test all of them. No No’s These pharmaceutical ingredients are not permitted in dietary supplements, but were found to be contaminating supplements.
Sildenafil What it is: A medication that dilates blood vessels in the penis, and is the active ingredient in Viagra Health issue: Can lower blood pressure to levels that are unsafe for people taking medications for diabetes, high blood pressure or high cholesterol Supplement type: Sexual enhancement Sibutramine What it is: An appetite suppressant removed from the U.S. market in 2010 Health issue: Increased risk of heart attack or stroke Supplement type: Weight loss Phenolphthalein What it is: A laxative removed from the U.S. market in 1999 Health issue: Potential carcinogen Supplement type: Weight loss Anabolic steroids What they are: Chemicals related to the male sex hormone testosterone Health issue: Associated with liver injury, kidney damage, heart attack and stroke Supplement type: Muscle building Aromatase inhibitors What they are: A class of drugs that lower estrogen levels, and are used to treat breast cancer Health issue: Associated with decreased bone growth, infertility, liver dysfunction Supplement type: Muscle building These supplements aren’t subject to the same regulations, testing and approval process that are required for pharmaceutical drugs. But if the FDA identifies tainted supplements after they’re on the market, the agency can issue public warnings or suggest the company voluntarily remove the product.
Whether that approach is effective raises questions, though, says general internist Pieter Cohen of Cambridge Health Alliance in Cambridge, Mass., who was not involved in the new work. Voluntary recalls don’t necessarily mean a product is completely removed from shelves or that consumers become aware and stop using a product, Cohen’s research has found.
And only 360 of the 776 supplements flagged as tainted from 2007 to 2016 were recalled, the study found. “What really jumped out at me,” Cohen says, is that “when the FDA detects drugs in supplements, more than half the time the product isn’t even recalled.”
Supplement use does carry health risks. A 2015 study estimated that 23,000 emergency room visits each year are due to health problems related to dietary supplements. Of those, about 2,100 patients are hospitalized annually, commonly for symptoms related to heart trouble. In 2013, 20 percent of drug-induced liver injury cases recorded in the Drug-Induced Liver Injury Network registry were caused by dietary supplements. That’s up from 7 percent in 2004. Liver damage can be fatal or require a liver transplant. A 2013 report by the U.S. Centers for Disease Control and Prevention on 29 cases of liver injury found that 24 of those patients reported using a dietary supplement for weight loss.
“The law allows companies to advertise supplements as if they’re good for your health, even if there’s no evidence in humans that that’s the case,” Cohen says. He began studying dietary supplements after noting that his patients developed health problems, including panic attacks, chest pain and kidney failure, related to weight-loss supplements. One patient was suspended from his job when his urine tested positive for amphetamine; a chemical derivative of the drug was found in the weight-loss pills that he was taking.
Cohen’s recommendation? Avoid supplements “that promise you anything.”
Animated characters can learn from online tutorials, too.
A new computer program teaches virtual avatars new skills, such as dances, acrobatic stunts and martial art moves, from YouTube videos. This kind of system, described in the November ACM Transactions on Graphics, could render more physically coordinated characters for movies and video games, or serve as a virtual training ground for robots.
“I was really impressed” by the program, says Daniel Holden, a machine-learning researcher at Ubisoft La Forge in Montreal not involved in the work. Rendering accurate, natural-looking movements based on everyday video clips “has always been a goal for researchers in this field.” Animated characters typically have learned full-body motions by studying motion capture data, collected by a camera that tracks special markers attached to actors’ bodies. But this technique requires special equipment and often works only indoors.
The new program leverages a type of computer code known as an artificial neural network, which roughly mimics how the human brain processes information. Trained on about 100,000 images of people in various poses, the program first estimates an actor’s pose in each frame of a video clip. Then, it teaches a virtual avatar to re-create the actor’s motion using reinforcement learning, giving the character a virtual “reward” when it matches the video actor’s pose in a frame.
Computer scientist Jason Peng and colleagues at the University of California, Berkeley, fed YouTube videos into the system to teach characters to do somersaults, backflips, vaulting and other stunts. Even characters such as animated Atlas robots with bodies drastically different from those of their human video teachers mastered these motions (SN: 12/13/14, p. 16). Characters could also perform under conditions not seen in the training video, like cartwheeling while being pelted with blocks or moving across terrain riddled with holes. The work, also reported October 8 at arXiv.org, is a step “toward making motion capture easier, cheaper and more accessible,” Holden says. Videos could be used to render virtual versions of outdoor activities, since motion capture is difficult to do outdoors, or to create lifelike avatars of large animals that would be difficult to stick with motion capture markers.
This kind of program may also someday be used to teach robots new skills, Peng says. An animated version of a robot could master skills in a virtual environment before that learned computer code powered a machine in the physical world.
These animated characters still struggle with nimble dance steps, such as the “Gangnam Style” jig, and learn from short clips featuring only a single person. David Jacobs, a computer scientist at the University of Maryland in College Park not involved in the work, looks forward to future virtual avatars that can reenact longer, more complex actions, such as pairs of people dancing or soccer teams playing a game.
“That’s probably a much harder problem, because [each] person’s not as clearly visible, but it would be really cool,” Jacobs says. “This is only the beginning.”
The cause of a rare polio-like disease continues to elude public health officials even as the number of U.S. cases grows.
Confirmed cases of acute flaccid myelitis cases have risen to 90 in 27 states, out of a possible 252 under investigation, the U.S. Centers for Disease Control and Prevention announced November 13. That’s up from 62 confirmed cases out of 127 suspected just a month ago (SN Online: 10/16/18). There were a record 149 cases in 2016. “I understand parents want answers,” Nancy Messonnier, director of the CDC’s National Center for Immunization and Respiratory Diseases in Atlanta, said at a news conference. The agency continues to investigate the disease, which causes weakness in one or more limbs and primarily affects children. But “right now the science doesn’t give us an answer,” she said.
A deep dive into 80 of the confirmed cases offered some details about the course of AFM. In most, fever or respiratory symptoms like coughing and congestion, or both, preceded limb weakness by three to 10 days. Most cases involved weakness in an upper limb, researchers report online November 13 in the Morbidity and Mortality Weekly Report.
Only two samples of cerebrospinal fluid — the clear fluid that bathes the brain and spinal cord — tested positive for a pathogen, each for a different enterovirus. Since 2014, when the first big outbreak of AFM occurred, most AFM spinal fluid samples haven’t produced a culprit, Messonnier said. The body may clear the pathogen or it hides in tissues, she said, or the body’s own immune response to a pathogen may lead to spinal cord damage.
“This time of year, many children have fever and respiratory symptoms [and] most of them do not go on to develop AFM,” Messonnier said. “We’re trying to figure out what the triggers are that would cause someone to develop AFM later.”
