Researchers from the Moscow Institute of Physics and Technology teamed up with colleagues from the U.S. and Switzerland and returned the state of a quantum computer a fraction of a second into the past. They also calculated the probability that an electron in empty interstellar space will spontaneously travel back into its recent past. The study is published in Scientific Reports.
“This is one in a series of papers on the possibility of violating the second law of thermodynamics. That law is closely related to the notion of the arrow of time that posits the one-way direction of time from the past to the future,” said the study’s lead author Gordey Lesovik, who heads the Laboratory of the Physics of Quantum Information Technology at MIPT.
“We began by describing a so-called local perpetual motion machine of the second kind. Then, in December, we published a paper that discusses the violation of the second law via a device called a Maxwell’s demon,” Lesovik said. “The most recent paper approaches the same problem from a third angle: We have artificially created a state that evolves in a direction opposite to that of the thermodynamic arrow of time.”
What makes the future different from the past
Most laws of physics make no distinction between the future and the past. For example, let an equation describe the collision and rebound of two identical billiard balls. If a close-up of that event is recorded with a camera and played in reverse, it can still be represented by the same equation. Moreover, it is not possible to distinguish from the recording if it has been doctored. Both versions look plausible. It would appear that the billiard balls defy the intuitive sense of time.
However, imagine recording a cue ball breaking the pyramid, the billiard balls scattering in all directions. In that case, it is easy to distinguish the real-life scenario from reverse playback. What makes the latter look so absurd is our intuitive understanding of the second law of thermodynamics—an isolated system either remains static or evolves toward a state of chaos rather than order.
Most other laws of physics do not prevent rolling billiard balls from assembling into a pyramid, infused tea from flowing back into the tea bag, or a volcano from “erupting” in reverse. But these phenomena are not observed, because they would require an isolated system to assume a more ordered state without any outside intervention, which runs contrary to the second law. The nature of that law has not been explained in full detail, but researchers have made great headway in understanding the basic principles behind it.
Spontaneous time reversal
Quantum physicists from MIPT decided to check if time could spontaneously reverse itself at least for an individual particle and for a tiny fraction of a second. That is, instead of colliding billiard balls, they examined a solitary electron in empty interstellar space.
“Suppose the electron is localized when we begin observing it. This means that we’re pretty sure about its position in space. The laws of quantum mechanics prevent us from knowing it with absolute precision, but we can outline a small region where the electron is localized,” says study co-author Andrey Lebedev from MIPT and ETH Zurich.
The physicist explains that the evolution of the electron state is governed by Schrödinger’s equation. Although it makes no distinction between the future and the past, the region of space containing the electron will spread out very quickly. That is, the system tends to become more chaotic. The uncertainty of the electron’s position is growing. This is analogous to the increasing disorder in a large-scale system—such as a billiard table—due to the second law of thermodynamics.
The four stages of the actual experiment on a quantum computer mirror the stages of the thought experiment involving an electron in space and the imaginary analogy with billiard balls. Each of the three systems initially evolves from order …more
“However, Schrödinger’s equation is reversible,” adds Valerii Vinokur, a co-author of the paper, from the Argonne National Laboratory, U.S. “Mathematically, it means that under a certain transformation called complex conjugation, the equation will describe a ‘smeared’ electron localizing back into a small region of space over the same time period.” Although this phenomenon is not observed in nature, it could theoretically happen due to a random fluctuation in the cosmic microwave background permeating the universe.The team set out to calculate the probability to observe an electron “smeared out” over a fraction of a second spontaneously localizing into its recent past. It turned out that even across the entire lifetime of the universe—13.7 billion years—observing 10 billion freshly localized electrons every second, the reverse evolution of the particle’s state would only happen once. And even then, the electron would travel no more than a mere one ten-billionth of a second into the past.
Large-scale phenomena involving billiard balls and volcanoes obviously unfold on much greater timescales and feature an astounding number of electrons and other particles. This explains why we do not observe old people growing younger or an ink blot separating from the paper.
Reversing time on demand
The researchers then attempted to reverse time in a four-stage experiment. Instead of an electron, they observed the state of a quantum computer made of two and later three basic elements called superconducting qubits.
Stage 1: Order. Each qubit is initialized in the ground state, denoted as zero. This highly ordered configuration corresponds to an electron localized in a small region, or a rack of billiard balls before the break.
Stage 2: Degradation. The order is lost. Just like the electron is smeared out over an increasingly large region of space, or the rack is broken on the pool table, the state of the qubits becomes an ever more complex changing pattern of zeros and ones. This is achieved by briefly launching the evolution program on the quantum computer. Actually, a similar degradation would occur by itself due to interactions with the environment. However, the controlled program of autonomous evolution will enable the last stage of the experiment.
Stage 3: Time reversal. A special program modifies the state of the quantum computer in such a way that it would then evolve “backwards,” from chaos toward order. This operation is akin to the random microwave background fluctuation in the case of the electron, but this time, it is deliberately induced. An obviously far-fetched analogy for the billiards example would be someone giving the table a perfectly calculated kick.
Stage 4: Regeneration. The evolution program from the second stage is launched again. Provided that the “kick” has been delivered successfully, the program does not result in more chaos but rather rewinds the state of the qubits back into the past, the way a smeared electron would be localized or the billiard balls would retrace their trajectories in reverse playback, eventually forming a triangle.
The researchers found that in 85 percent of the cases, the two-qubit quantum computer returned back into the initial state. When three qubits were involved, more errors happened, resulting in a roughly 50 percent success rate. According to the authors, these errors are due to imperfections in the actual quantum computer. As more sophisticated devices are designed, the error rate is expected to drop.
Interestingly, the time reversal algorithm itself could prove useful for making quantum computers more precise. “Our algorithm could be updated and used to test programs written for quantum computers and eliminate noise and errors,” Lebedev explained.
A team of Boston University researchers recently stuck a loudspeaker into one end of a PVC pipe. They cranked it up loud. What did they hear? Nothing.
How was this possible? Did they block the other end of the pipe with noise canceling foams or a chunk of concrete? No, nothing of the sort. The pipe was actually left open save for a small, 3D-printed ring placed around the rim. That ring cut 94% of the sound blasting from the speaker, enough to make it inaudible to the human ear.
The mathematically designed, 3D-printed acoustic metamaterial is shaped in such a way that it sends incoming sounds back to where they came from. [Photo: Cydney Scott/Boston University]
Dubbed an “acoustic meta-material,” the ring was printed from a mathematically modeled design, shaped in such a way that it can catch certain frequencies passing through the air and reflect them back toward their source. Typical acoustic paneling works differently, absorbing sound and turning the vibrations into heat. But what’s particularly trippy is that this muffler is completely open. Air and light can travel through it–just sound cannot.
The implications for architecture and interior design are remarkable, because these metamaterials could be applied to the built environment in many different ways. For instance, they could be stacked to build soundproof yet transparent walls. Cubicles will never be the same.
The researchers also believe that HVAC systems could be fitted with these silencers, and drones could have their turbines muted with such rings. Even in MRI machines, which can be harrowingly loud for patients trapped in a small space, could be quieted. There’s really no limit to the possibilities, but it does sound like these silencers will need to be tailored to circumstance. “The idea is that we can now mathematically design an object that can blocks the sounds of anything,” says Boston University professor Xin Zhang, in a press release.
Getting enough deep sleep might be the key to preventing dementia. In a series of recent experiments on mice, researchers discovered that deep sleep helps the brain clear out potentially toxic waste. The discovery reinforces how critical quality sleep is for brain health and suggests sleep therapies might curb the advance of memory-robbing ailments, like Alzheimer’s disease.
“Alzheimer’s disease is a major problem for the patients, their families and society,” said Maiken Nedergaard, a neurologist at the University of Rochester Medical Center in New York, who led the new research. “Understanding how sleep can improve clearance of amyloid could have major impact on treatment.”
Clearing The Clutter
Cerebrospinal fluid churns through a system of brain tunnels piped in the spaces between brain cells and blood vessels. Scientists call it the glymphatic system. This system circulates nutrients like glucose, the brain’s primary energy source, and washes away potentially toxic waste.
And it may be the reason why animals even need sleep. The system takes out the brain’s trash when we’re asleep, and it shuts down when we’re awake. Nedergaard and her team were curious if the system works best and clears more waste — like Alzheimer’s causing beta amyloid plaque — when animals are in deep sleep.
To find out, the researchers used six different anesthetics to put mice into deep sleep. Then they tracked cerebrospinal fluid as it flowed into the brain. As the mice slept, the researchers watched the rodents’ brain activity on an electroencephalograph, or EEG, and recorded the animals’ blood pressures and heart and respiratory rates.
Rest And Restore
Mice anesthetized with a combination of two drugs, ketamine and xylazine, showed the strongest deep sleep brain waves and these brain waves predicted CSF flow into the brain, the researchers found. Their findings imply that the glymphatic system is indeed more active during the deepest sleep.
When the researchers analyzed the mice’s vital signs, they were surprised to find the animals anesthetized with the deep sleep drug combo of ketamine and xylazine also had the lowest heart rates, Nedergaard and her team report Wednesday in the journal Science Advances. The discovery means “low heart rate, which is a characteristic of athletes, is also a potent enhancer of glymphatic flow,” Nedergaard said. The results may explain why exercise buffers against poor memory.
The findings also have implications for people undergoing surgery. General anesthesia as well as long-term sedation in the intensive care unit is associated with delirium and difficulty with memory, especially in the elderly.
But most importantly, the research shows quality sleep is vital for brain health. “Focusing on sleep in the early stages of dementia might be able to slow progression of the disease,” Nedergaard said.
Clouds, however, naturally reflect the sun (it’s why Venus – a planet with permanent cloud cover – shines so brightly in our night sky). Marine stratocumulus clouds are particularly important, covering around 20% of the Earth’s surface while reflecting 30% of total solar radiation. Stratocumulus clouds also cool the ocean surface directly below. Proposals to make these clouds whiter – or “marine cloud brightening” – are amongst the more serious projects now being considered by various bodies, including the US National Academies of Sciences, Engineering, and Medicine’s new “solar geoengineering” committee.
Stephen Salter, Emeritus professor at the University of Edinburgh, has been one of the leading voices of this movement. In the 1970s, when Salter was working on waves and tidal power, he came across studies examining the pollution trails left by shipping. Much like the aeroplane trails we see criss-crossing the sky, satellite imagery had revealed that shipping left similar tracks in the air above the ocean – and the research revealed that these trails were also brightening existing clouds.
The pollution particles had introduced “condensation nuclei” (otherwise scarce in the clean sea air) for water vapour to congregate around. Because the pollution particles were smaller than the natural particles, they produced smaller water droplets; and the smaller the water droplet, the whiter and more reflective it is. In 1990, British atmospheric scientist John Latham proposed doing this with benign, natural particles such as sea salt. But he needed an engineer to design a spraying system. So he contacted Stephen Salter.
The pollution trails left by ships on the ocean naturally brighten the clouds above (Credit: Nasa Goddard Space Flight Center)
Spraying about 10 cubic metres per second could undo all the [global warming] damage we’ve done to the world up till now
“I didn’t realise quite how hard it was going to be,” Salter now admits. Seawater, for instance, tends to clog up or corrode spray nozzles, let alone ones capable of spraying particles just 0.8 micron in size. And that’s not to mention the difficulties of modelling the effects on the weather and climate. But his latest design, he believes, is ready to build: an unmanned hydro-foil ship, computer-controlled and wind-powered, which pumps an ultra-fine mist of sea salt toward the cloud layer.
“Spraying about 10 cubic metres per second could undo all the [global warming] damage we’ve done to the world up until now,” Salter claims. And, he says, the annual cost would be less than the cost to host the annual UN Climate Conference – between $100-$200 million each year.
Salter calculates that a fleet of 300 of his autonomous ships could reduce global temperatures by 1.5C. He also believes that smaller fleets could be deployed to counter-act regional extreme weather events. Hurricane seasons and El Niño, exacerbated by high sea temperatures, could be tamed by targeted cooling via marine cloud brightening. A PhD thesis from the University of Leeds in 2012 stated that cloud brightening could, “decrease sea surface temperatures during peak tropical cyclone season… [reducing] the energy available for convection and may reduce intensity of storms”.
Salter boasts that 160 of his ships could “moderate an El Niño event, and a few hundred [would] stop hurricanes”. The same could be done, he says, to protect large coral reefs such as the Great Barrier Reef, and even cool the polar regions to allow sea ice to return.
Hazard warning
So, what’s the catch? Well, there’s a very big catch indeed. The potential side-effects of solar geoengineering on the scale needed to slow hurricanes or cool global temperatures are not well understood. According to various theories, it could prompt droughts, flooding, and catastrophic crop failures; some even fear that the technology could be weaponised (during the Vietnam War, American forces flew thousands of “cloud seeding” missions to flood enemy troop supply lines). Another major concern is that geoengineering could be used as an excuse to slow down emissions reduction, meaning CO2 levels continue to rise and oceans continue to acidify – which, of course, brings its own serious problems.
Stephen Salter believes that a fleet of 300 of his autonomous ships could reduce global temperatures by 1.5C (Credit: James MacNeill)
A rival US academic team – The MCB Project – is less gung-ho than Salter. Kelly Wanser, the principal director of The MCB Project, is based in Silicon Valley. When it launched in 2010 with seed funding from the Gates Foundation, it received a fierce backlash. Media articles talked of “cloud-wrenching cronies” and warned of the potential for “unilateral action on geoengineering”. Since then, Wanser has kept relatively low-key.
Her team’s design is similar to commercial snow-making machines for ski resorts, yet capable of spraying “particles ten thousand times smaller [than snow]… at three trillion particles per second”. The MCB Project hopes to test this near Monterey Bay, California, where marine stratocumulus clouds waft overland. They would start with a single cloud to track its impact.
“One of the strengths of marine cloud brightening is it can be very gradually scaled,” says Wanser. “You [can] get a pretty good grasp of whether and how you are brightening clouds, without doing things that impact climate or weather.”
Such a step-by-step research effort, says Wanser, would take a decade at least. But due to the controversy it attracts, this hasn’t even started yet. Not one cloud has yet been purposefully brightened by academics – although cargo shipping still does this unintentionally, with dirty particles, every single day.
The DNA of life on Earth naturally stores its information in just four key chemicals — guanine, cytosine, adenine and thymine, commonly referred to as G, C, A and T, respectively.
Now scientists have doubled this number of life’s building blocks, creating for the first time a synthetic, eight-letter genetic language that seems to store and transcribe information just like natural DNA.
In a study published on 22 February in Science1, a consortium of researchers led by Steven Benner, founder of the Foundation for Applied Molecular Evolution in Alachua, Florida, suggests that an expanded genetic alphabet could, in theory, also support life.
“It’s a real landmark,” says Floyd Romesberg, a chemical biologist at the Scripps Research Institute in La Jolla, California. The study implies that there is nothing particularly “magic” or special about those four chemicals that evolved on Earth, says Romesberg. “That’s a conceptual breakthrough,” he adds.
[…]
Still, Benner says that the work shows that life could potentially be supported by DNA bases with different structures from the four that we know, which could be relevant in the search for signatures of life elsewhere in the Universe.
Adding letters to DNA could also have more down-to-earth applications.
With more diversity in the genetic building blocks, scientists could potentially create RNA or DNA sequences that can do things better than the standard four letters, including functions beyond genetic storage.
For example, Benner’s group previously showed that strands of DNA that included Z and P were better at binding to cancer cells than sequences with just the standard four bases3. And Benner has set up a company which commercialises synthetic DNA for use in medical diagnostics.
The researchers could potentially use their synthetic DNA to create novel proteins as well as RNA. Benner’s team has also developed further pairs of new bases, opening up the possibility of creating DNA structures that contain 10 or even 12 letters. But the fact that the researchers have already expanded the genetic alphabet to eight is in itself remarkable, says Romesberg. “It’s already doubling what nature has.”
The remarkable properties of a recently-discovered squid protein could revolutionize materials in a way that would be unattainable with conventional plastic, finds a review published in Frontiers in Chemistry. Originating in the ringed teeth of a squid’s predatory arms, this protein can be processed into fibers and films with applications ranging from ‘smart’ clothes for health monitoring, to self-healing recyclable fabrics that reduce microplastic pollution. Materials made from this protein are eco-friendly and biodegradable, with sustainable large-scale production achieved using laboratory culture methods.
“Squid proteins can be used to produce next generation materials for an array of fields including energy and biomedicine, as well as the security and defense sector,” says lead author Melik Demirel, Lloyd and Dorothy Foehr Huck Endowed Chair in Biomimetic Materials, and Director of Center for Research on Advanced Fiber Technologies (CRAFT) at Penn State University, USA. “We reviewed the current knowledge on squid ring teeth-based materials, which are an excellent alternative to plastics because they are eco-friendly and environmentally sustainable.”
Squid ring teeth are all-rounders
As humanity awakens to the aftermath of a 100-year party of plastic production, we are beginning to heed nature’s warnings—and its solutions.
“Nature produces a variety of smart materials capable of environmental sensing, self-healing and exceptional mechanical function. These materials, or biopolymers, have unique physical properties that are not readily found in synthetic polymers like plastic. Importantly, biopolymers are sustainable and can be engineered to enhance their physical properties,” explains Demirel.
The oceans, which have borne the brunt of plastic pollution, are at the center of the search for sustainable alternatives. A newly-discovered protein from squid ring teeth (SRT) – circular predatory appendages located on the suction cups of squid, used to strongly grasp prey—has gained interest because of its remarkable properties and sustainable production.
The elasticity, flexibility and strength of SRT-based materials, as well as their self-healing, optical, and thermal and electrical conducting properties, can be explained by the variety of molecular arrangements they can adopt. SRT proteins are composed of building blocks arranged in such a way that micro-phase separation occurs. This is a similar situation to oil and water but on a much smaller, nano-scale. The blocks cannot separate completely to produce two distinct layers, so instead molecular-level shapes are created, such as repeating cylindrical blocks, disordered tangles or ordered layers. The shapes formed dictate the property of the material and scientists have experimented with these to produce SRT-based products for a variety of uses.
In the textiles industry, SRT protein could address one of the main sources of microplastic pollution by providing an abrasion-resistant coating that reduces microfiber erosion in washing machines. Similarly, a self-healing SRT protein coating could increase the longevity and safety of damage-prone biochemical implants, as well as garments tailored for protection against chemical and biological warfare agents.
It is even possible to interleave multiple layers of SRT proteins with other compounds or technology, which could lead to the development of ‘smart’ clothes that can protect us from pollutants in the air while also keeping an eye on our health. The optical properties of SRT-based materials mean these clothes could also display information about our health or surroundings. Flexible SRT-based photonic devices—components that create, manipulate or detect light, such as LEDs and optical displays, which are typically manufactured with hard materials like glass and quartz—are currently in development.
“SRT photonics are biocompatible and biodegradable, so could be used to make not only wearable health monitors but also implantable devices for biosensing and biodetection,” adds Demirel.
No squid was harmed in the making of this film
One of the main advantages of SRT-based materials over synthetic materials and plastics made from fossil fuels are its eco-credentials. SRT proteins are cheaply and easily produced from renewable resources and researchers have found a way of producing it without catching a squid.”We don’t want to deplete natural squid resources and hence we produce these proteins in genetically modified bacteria. The process is based on fermentation and uses sugar, water, and oxygen to produce biopolymers,” explains Demirel.
It is hoped that the SRT-based prototypes will soon become available more widely, but more development is needed.
Demirel explains, “Scaling up these materials requires additional work. We are now working on the processing technology of these materials so that we can make them available in industrial manufacturing processes.”
A team of chemists at Purdue may have found a partial solution to our plastic woes. As detailed in a paper published this week in Sustainable Chemistry and Engineering, the chemists discovered a way to convert polypropylene—a type of plastic commonly used in toys, medical devices, and product packaging like potato chip bags—into gasoline and diesel-like fuel. The researchers said that this fuel is pure enough to be used as blendstock, a main component of fuel used in motorized vehicles.
Polypropylene waste accounts for just under a quarter of the estimated 5 billion tons of plastic that have amassed in the world’s landfills in the last 50 years.
To turn polypropylene into fuel, the researchers used supercritical water, a phase of water that demonstrates characteristics of both a liquid and a gas depending on the pressure and temperature conditions. Purdue chemist Linda Wang and her colleagues heated water to between 716 and 932 degrees Fahrenheit at pressures approximately 2300 times greater than the atmospheric pressure at sea level.
When purified polypropylene waste was added to the supercritical water, it was converted into oil within in a few hours, depending on the temperature. At around 850 degrees Fahrenheit, the conversion time was lowered to under an hour.
The byproducts of this process include gasoline and diesel-like oils. According to the researchers, their conversion process could be used to convert roughly 90 percent of the world’s polypropylene waste each year into fuel.
Scientists from ITMO in collaboration with international colleagues have proposed new DNA-based nanomachines that can be used for gene therapy for cancer. This new invention can greatly contribute to more effective and selective treatment of oncological diseases. The results were published in Angewandte Chemie.
Gene therapy is considered one of the promising ways of treating oncological diseases, even though the current approaches are far from perfect. Oftentimes, the agents fail to discern malignant cells from healthy ones, and are bad at interacting with folded RNA targets.
In order to solve this issue, scientists, including a Russian team from ITMO University headed by professor Dmitry Kolpashchikov, proposed special nanomachines. They sought to develop particular molecules, deoxyribozymes, which can interact with targeted RNA, bind them, unfold and cleave. According to the idea, these nanomachines have to recognize DNA oncomarkers and form complexes that can break down messenger RNA of vital genes with high selectivity, which will then result in apoptotic death of malignant cells.
The researchers tested the efficiency of the new machines in a model experiment and learned that they can cleave folded RNA molecules better than the original deoxyribozymes. They showed that the design of the nanomachine makes it possible to break down targeted RNA in the presence of a DNA oncomarker only, and the use of RNA-unfolding arms provides for better efficiency. The scientists also learned that the nanomachine can inhibit the growth of malignant cells, though cellular experiments didn’t show high specificity. The researchers associate this result with a possibly poor choice of the RNA target and a low stability of DNA structures in the cell.
The new approach differs fundamentally from the ones used before. The existing gene therapy agents are aimed at suppressing the expression of oncological markers. In the research in question, the scientists focused on the messenger RNA of vital genes, and the oncological marker was used as an activator. This makes it possible to apply the DNA nanomachine in treating any kind of cancer by using new DNA oncomarkers for activating the breakdown of targeted molecules.
The new invention opens new ways of treating oncological diseases. Still, there are many experiments to be conducted before it can be applied in therapy.
“For now, we are trying to introduce new functional elements in the framework that will contribute to a more effective recognition of oncological markers, and are also optimizing the DNA nanomachine for various RNA targets. In order to improve the efficiency and selectiveness of our constructions in cellular conditions, we are selecting new RNA targets and studying the stability of DNA machines in cells, which we plan to improve with the help of already existing chemical modifications,” comments Daria Nedorezova, Master’s student at ITMO University.
The Zooniverse is the world’s largest and most popular platform for people-powered research. This research is made possible by volunteers — hundreds of thousands of people around the world who come together to assist professional researchers. Our goal is to enable research that would not be possible, or practical, otherwise. Zooniverse research results in new discoveries, datasets useful to the wider research community, and many publications.
At the Zooniverse, anyone can be a researcher
You don’t need any specialised background, training, or expertise to participate in any Zooniverse projects. We make it easy for anyone to contribute to real academic research, on their own computer, at their own convenience.
You’ll be able to study authentic objects of interest gathered by researchers, like images of faraway galaxies, historical records and diaries, or videos of animals in their natural habitats. By answering simple questions about them, you’ll help contribute to our understanding of our world, our history, our Universe, and more.
With our wide-ranging and ever-expanding suite of projects, covering many disciplines and topics across the sciences and humanities, there’s a place for anyone and everyone to explore, learn and have fun in the Zooniverse. To volunteer with us, just go to the Projects page, choose one you like the look of, and get started.
Scientists a Hokkaido University have found a way to create materials that actually get stronger the more you use them. By mimicking the mechanism that allows living muscles to grow and strengthen after exercise, the team led by Jian Ping Gong developed a polymer that breaks down under mechanical stress, then regrows itself into a stronger configuration by feeding off a nutrient bath.
One of the drawbacks of non-living materials is that they have a very finite service life compared to living, organic materials. Materials like steel, plastic, ceramics, and textiles wear out with use at a surprisingly fast rate compared to comparable living things. Metals undergo fatigue, plastics crumble, ceramics crack, and textiles have a sadly short life compared to the skin they cover.
The reason for this is that living tissue can not only regrow itself, it can become stronger the more it’s used. That’s why a human heart can pump at a rate of about 72 beats per minute, 24 hours a day, 365 days a year, for over a century. It’s also why exercise can make skeletal muscles stronger. A workout in the gym that makes a human healthier would just be so much wear and tear to a machine.
[…]
the Hokkaido team used what is called double-network hydrogels. Like other hydrogels, these are polymers that are 85 percent water by weight, but in this case, the material consist of both a rigid, brittle polymer and a soft, stretchable one. In this way, the finished product is both soft and tough.
However, the clever bit is that under laboratory conditions the hydrogel was immersed in a bath of monomers, which are the individual molecular links that make up a polymer. These serve the same function in the muscle-mimicking material as amino acids do in living tissue.
According to the team, when the hydrogel is stretched, some of the brittle polymer chains break, creating a chemical species called “mechanoradicals” at the end of the broken polymer chains. These are very reactive and quickly join up with the floating monomers to form a new, stronger polymer chain.
Under testing, the hydrogel acted much like muscles under strength training. It became 1.5 times stronger, 23 times stiffer, and increased in weight by 86 percent. It was even possible to control the properties of the material by using heat-sensitive monomers and applying high temperatures to make it more water resistant.
Gong says this approach could lead to materials suitable for a variety of applications, such as in flexible exosuits for patients with skeletal injuries that become stronger with use.
A distinct pathway in the white matter part of the brain known as the cingulum bundle can be used to alleviate stress and anxiety during awake brain surgery, according to new research published today in The Journal of Clinical Investigation. When electrically stimulated, this pathway triggers instantaneous laughter in the patient. But unlike previous experiments, this laughter was also accompanied by positive, uplifting feelings. Preliminary research suggests this technique could be used to calm patients during awake brain surgery, with the authors of the new study, led by neuroscientist Kelly Bijanki from Emory University School of Medicine, saying the findings could also lead to innovative new treatments for depression, anxiety, and chronic pain.
To advance the state-of-the-art in speech neuroprosthesis, we combined the recent advances in deep learning with the latest innovations in speech synthesis technologies to reconstruct closed-set intelligible speech from the human auditory cortex. We investigated the dependence of reconstruction accuracy on linear and nonlinear (deep neural network) regression methods and the acoustic representation that is used as the target of reconstruction, including auditory spectrogram and speech synthesis parameters. In addition, we compared the reconstruction accuracy from low and high neural frequency ranges. Our results show that a deep neural network model that directly estimates the parameters of a speech synthesizer from all neural frequencies achieves the highest subjective and objective scores on a digit recognition task, improving the intelligibility by 65% over the baseline method which used linear regression to reconstruct the auditory spectrogram
If you bled when you brushed your teeth this morning, you might want to get that seen to. We may finally have found the long-elusive cause of Alzheimer’s disease: Porphyromonas gingivalis, the key bacteria in chronic gum disease.
That’s bad, as gum disease affects around a third of all people. But the good news is that a drug that blocks the main toxins of P. gingivalis is entering major clinical trials this year, and research published today shows it might stop and even reverse Alzheimer’s. There could even be a vaccine.
Alzheimer’s is one of the biggest mysteries in medicine. As populations have aged, dementia has skyrocketed to become the fifth biggest cause of death worldwide. Alzheimer’s constitutes some 70 per cent of these cases and yet, we don’t know what causes it.
Bacteria in the brain
The disease often involves the accumulation of proteins called amyloid and tau in the brain, and the leading hypothesis has been that the disease arises from defective control of these two proteins.
Bacteria involved in gum disease and other illnesses have been found after death in the brains of people who had Alzheimer’s, but until now, it hasn’t been clear whether these bacteria caused the disease or simply got in via brain damage caused by the condition.
Gum disease link
Multiple research teams have been investigating P. gingivalis, and have so far found that it invades and inflames brain regions affected by Alzheimer’s; that gum infections can worsen symptoms in mice genetically engineered to have Alzheimer’s; and that it can cause Alzheimer’s-like brain inflammation, neural damage, and amyloid plaques in healthy mice.
“When science converges from multiple independent laboratories like this, it is very compelling,” says Casey Lynch of Cortexyme, a pharmaceutical firm in San Francisco, California.
In new study, Cortexyme have now reported finding the toxic enzymes – called gingipains – that P. gingivalis uses to feed on human tissue in 96 per cent of the 54 Alzheimer’s brain samples they looked at, and found the bacteria themselves in all three Alzheimer’s brains whose DNA they examined.
The bacteria and its enzymes were found at higher levels in those who had experienced worse cognitive decline, and had more amyloid and tau accumulations. The team also found the bacteria in the spinal fluid of living people with Alzheimer’s, suggesting that this technique may provide a long-sought after method of diagnosing the disease.
A team of researchers based at the Universities of Oxford and Edinburgh have recreated for the first time the famous Draupner freak wave measured in the North Sea in 1995.
The Draupner wave was one of the first confirmed observations of a freak wave in the ocean; it was observed on the 1st of January 1995 in the North Sea by measurements made on the Draupner Oil Platform. Freak waves are unexpectedly large in comparison to surrounding waves. They are difficult to predict, often appearing suddenly without warning, and are commonly attributed as probable causes for maritime catastrophes such as the sinking of large ships.
The team of researchers set out to reproduce the Draupner wave under laboratory conditions to understand how this freak wave was formed in the ocean. They successfully achieved this reconstruction by creating the wave using two smaller wave groups and varying the crossing angle – the angle at which the two groups travel.
Dr. Mark McAllister at the University of Oxford’s Department of Engineering Science said: “The measurement of the Draupner wave in 1995 was a seminal observation initiating many years of research into the physics of freak waves and shifting their standing from mere folklore to a credible real-world phenomenon. By recreating the Draupner wave in the lab we have moved one step closer to understanding the potential mechanisms of this phenomenon.”
It was the crossing angle between the two smaller groups that proved critical to the successful reconstruction. The researchers found it was only possible to reproduce the freak wave when the crossing angle between the two groups was approximately 120 degrees.
When waves are not crossing, wave breaking limits the height that a wave can achieve. However, when waves cross at large angles, wave breaking behaviour changes and no longer limits the height a wave can achieve in the same manner.
Prof Ton van den Bremer at the University of Oxford said: “Not only does this laboratory observation shed light on how the famous Draupner wave may have occurred, it also highlights the nature and significance of wave breaking in crossing sea conditions. The latter of these two findings has broad implications, illustrating previously unobserved wave breaking behaviour, which differs significantly from current state-of-the-art understanding of ocean wave breaking.”
To the researchers’ amazement, the wave they created bore an uncanny resemblance to “The Great Wave off Kanagawa’ – also known as “The Great Wave’ – a woodblock print published in the early 1800s by the Japanese artist Katsushika Hokusai. Hokusai’s image depicts an enormous wave threatening three fishing boats and towers over Mount Fuji which appears in the background. Hokusai’s wave is believed to depict a freak, or ‘rogue,” wave.
The laboratory-created freak wave also bears strong resemblances with photographs of freak waves in the ocean.
The researchers hope that this study will lay the groundwork for being able to predict these potentially catastrophic and hugely damaging waves that occur suddenly in the ocean without warning.
[…] today most of us have indoor jobs, and when we do go outside, we’ve been taught to protect ourselves from dangerous UV rays, which can cause skin cancer. Sunscreen also blocks our skin from making vitamin D, but that’s OK, says the American Academy of Dermatology, which takes a zero-tolerance stance on sun exposure: “You need to protect your skin from the sun every day, even when it’s cloudy,” it advises on its website. Better to slather on sunblock, we’ve all been told, and compensate with vitamin D pills.
Yet vitamin D supplementation has failed spectacularly in clinical trials. Five years ago, researchers were already warning that it showed zero benefit, and the evidence has only grown stronger. In November, one of the largest and most rigorous trials of the vitamin ever conducted—in which 25,871 participants received high doses for five years—found no impact on cancer, heart disease, or stroke.
How did we get it so wrong? How could people with low vitamin D levels clearly suffer higher rates of so many diseases and yet not be helped by supplementation?
As it turns out, a rogue band of researchers has had an explanation all along. And if they’re right, it means that once again we have been epically misled.
These rebels argue that what made the people with high vitamin D levels so healthy was not the vitamin itself. That was just a marker. Their vitamin D levels were high because they were getting plenty of exposure to the thing that was really responsible for their good health—that big orange ball shining down from above.
A method for fooling breast cancer cells into fat cells has been discovered by researchers from the University of Basel. The team were able to transform EMT-derived breast cancer cells into fat cells in a mouse model of the disease – preventing the formation of metastases. The proof-of-concept study was published in the journal Cancer Cell.
Malignant cells can rapidly respond and adapt to changing microenvironmental conditions, by reactivating a cellular process called epithelial-mesenchymal transition (EMT), enabling them to alter their molecular properties and transdifferentiate into a different type of cell (cellular plasticity).
Senior author of the study Gerhard Christofori, professor of biochemistry at the University of Basel, commented in a recent press release: “The breast cancer cells that underwent an EMT not only differentiated into fat cells, but also completely stopped proliferating.”
“As far as we can tell from long-term culture experiments, the cancer cells-turned-fat cells remain fat cells and do not revert back to breast cancer cells,” he explained.
The three authors, who describe themselves as leftists, spent 10 months writing 20 hoax papers they submitted to reputable journals in gender, race, sexuality, and related fields. Seven were accepted, four were published online, and three were in the process of being published when questions raised in October by a skeptical Wall Street Journal editorial writer forced them to halt their project.
One of their papers, about canine rape culture in dog parks in Portland, Ore., was initially recognized for excellence by the journal Gender, Place, and Culture, the authors reported.
The hoax was dubbed “Sokal Squared,” after a similar stunt pulled in 1996 by Alan Sokal, then a physicist at New York University.
After their ruse was revealed, the three authors described their project in an October article in the webzine Areo, which Pluckrose edits. Their goal, they wrote, was to “to study, understand, and expose the reality of grievance studies, which is corrupting academic research.” They contend that scholarship that tends to social grievances now dominates some fields, where students and others are bullied into adhering to scholars’ worldviews, while lax publishing standards allow the publication of clearly ludicrous articles if the topic is politically fashionable.
[…]
In November the investigating committee reported that the dog-park article contained knowingly fabricated data and thus constituted research misconduct. The review board also determined that the hoax project met the definition for human-subjects research because it involved interacting with journal editors and reviewers. Any research involving human subjects (even duped journal editors, apparently) needs IRB approval first, according to university policy.
“Your efforts to conduct human-subjects research at PSU without a submitted nor approved protocol is a clear violation of the policies of your employer,” McLellan wrote in an email to Boghossian.
The decision to move ahead with disciplinary action came after a group of faculty members published a letter in the student newspaper decrying the hoax as “lies peddled to journals, masquerading as articles.” These “lies” are designed “not to critique, educate, or inspire change in flawed systems,” they wrote, “but rather to humiliate entire fields while the authors gin up publicity for themselves without having made any scholarly contributions whatsoever.” Such behavior, they wrote, hurts the reputations of the university as well as honest scholars who work there. “Worse yet, it jeopardizes the students’ reputations, as their degrees in the process may become devalued.”
[…]
Meanwhile, within the first 24 hours of news leaking about the proceedings against him, more than 100 scholars had written letters defending Boghossian, according to his media site, which posted some of them.
Steven Pinker, a professor of psychology at Harvard University, was among the high-profile scholars who defended him. “Criticism and open debate are the lifeblood of academia; they are what differentiate universities from organs of dogma and propaganda,” Pinker wrote. “If scholars feel they have been subject to unfair criticism, they should explain why they think the critic is wrong. It should be beneath them to try to punish and silence him.”
Richard Dawkins, an evolutionary biologist, author, and professor emeritus at the University of Oxford, had this to say: “If the members of your committee of inquiry object to the very idea of satire as a form of creative expression, they should come out honestly and say so. But to pretend that this is a matter of publishing false data is so obviously ridiculous that one cannot help suspecting an ulterior motive.”
Sokal, who is now at University College London, wrote that Boghossian’s hoax had served the public interest and that the university would become a “laughingstock” in academe as well as the public sphere if it insisted that duping editors constituted research on human subjects.
One of Boghossian’s co-author, Lindsay, urged him in the video they posted to emphasize that the project amounted to an audit of certain sectors of academic research. “People inside the system aren’t allowed to question the system? What kind of Orwellian stuff is that?” Lindsay asked.
Millions of Americans might be mistaken about their self-professed food allergy, suggests a new survey. It found that while nearly 20 percent of people said they had a food allergy, only half as many people reported the sort of symptoms you’d expect from eating something you’re allergic to.
Researchers surveyed more than 40,000 adults via the phone and internet between October 2015 to September 2016. The volunteers were asked if they had any food allergies and about what symptoms they typically had. They were also asked if they had ever been formally tested and diagnosed with a food allergy by a doctor.
All told, 19 percent of the nationally representative group reported having a food allergy. But only 10.8 percent said they had symptoms consistent with an allergic reaction to food, such as hives, swelling of the lips or throat, and chest pain. The main culprits behind these allergies were shellfish, milk, and tree nuts. Those who didn’t have a convincing food allergy instead reported symptoms like stomach cramps, a stuffy nose, or nausea.
The findings, published Friday in JAMA Network Open, roughly match up to estimates from other studies, including those that confirmed a person’s food allergy with testing or medical records. In terms of the U.S. population, the study estimates, there are about 26 million adult Americans with a food allergy—and there are likely nearly as many Americans who wrongly say they have one. But that doesn’t mean huge swaths of people are pretending to have food allergies; it’s just that we could be a little confused about the terminology.
True allergies, as they’re known, happen when the immune system overreacts very quickly and in a specific way to a foreign substance harmless to us, whether it’s food or a piece of clothing. The antibodies usually responsible for an allergic reaction are called immunoglobulin E, or IgE. When doctors test for allergies, it’s IgE antibodies they’re looking for. But people can react badly to food for other reasons outside of this process.
Lactose intolerance is probably the best known example of this, and it happens because many adults are less able to break down lactose, the sugar commonly found in dairy products, into simpler sugars. Another genetic condition, celiac disease, makes people unable to digest gluten. Some people also seem to have delayed immune reactions to food without IgE in the picture, though we’re less sure about how commonly this happens and how to accurately diagnose it. Many doctors, for instance, criticize tests that promise to find these so-called food sensitivities with ease.
It’s likely then, the researchers say, that people might be mixing up a food intolerance or sensitivity with a food allergy.
What’s also concerning is that many people with likely food allergies in their survey have seemingly never talked to a doctor about it. Only half of the group said they had an official diagnosis from a physician. And while many of us develop food allergies early on in childhood, just about half reported finding out about their allergy as adults.
There’s a big molecule, a protein, inside the leaves of most plants. It’s called Rubisco, which is short for an actual chemical name that’s very long and hard to remember.
Amanda Cavanagh, a biologist and post-doctoral researcher at the University of Illinois, calls herself a big fan of Rubisco. “It’s probably the most abundant protein in the world,” she says. It’s also super-important.
Scientist Amanda Cavanagh snap freezes plant samples with liquid nitrogen to study how the metabolism differs between unmodified plants and plants engineered with alternate pathways for photorespiration.
Claire Benjamin/RIPE Project
Rubisco has one job. It picks up carbon dioxide from the air, and it uses the carbon to make sugar molecules. It gets the energy to do this from the sun. This is photosynthesis, the process by which plants use sunlight to make food, a foundation of life on Earth. Yay for Rubisco!
“But it has what we like to call one fatal flaw,” Cavanagh continues. Unfortunately, Rubisco isn’t picky enough about what it grabs from the air. It also picks up oxygen. “When it does that, it makes a toxic compound, so the plant has to detoxify it.”
Plants have a whole complicated chemical assembly line to carry out this detoxification, and the process uses up a lot of energy. This means the plant has less energy for making leaves, or food for us. (There is a family of plants, including corn and sugar cane, that developed another type of workaround for Rubisco, and those plants are much more productive.)
Cavanagh and her colleagues in a research program called Realizing Increased Photosynthetic Efficiency (RIPE), which is based at the University of Illinois, have spent the last five years trying to fix Rubisco’s problem. “We’re sort of hacking photosynthesis,” she says.
They experimented with tobacco plants, just because tobacco is easy to work with. They inserted some new genes into these plants, which shut down the existing detoxification assembly line and set up a new one that’s way more efficient. And they created super tobacco plants. “They grew faster, and they grew up to 40 percent bigger” than normal tobacco plants, Cavanagh says. These measurements were done both in greenhouses and open-air field plots.
An extraordinarily promising new technique using ultrasound to clear the toxic protein clumps thought to cause dementia and Alzheimer’s disease is moving to the first phase of human trials next year. The innovative treatment has proven successful across several animal tests and presents an exciting, drug-free way to potentially battle dementia.
The ultrasound treatment was first developed back in 2015 at the University of Queensland. The initial research was working to find a way to use ultrasound to temporarily open the blood-brain barrier with the goal of helping dementia-battling antibodies better reach their target in the brain. However, early experiments with mice surprisingly revealed the targeted ultrasound waves worked to clear toxic amyloid protein plaques from the brain without any additional therapeutic drugs.
“The ultrasound waves oscillate tremendously quickly, activating microglial cells that digest and remove the amyloid plaques that destroy brain synapses,” explained Jürgen Götz, one of the researchers on the project back in 2015. “The word ‘breakthrough’ is often mis-used, but in this case I think this really does fundamentally change our understanding of how to treat this disease, and I foresee a great future for this approach.”
A team of researchers from Austria, Italy and Sweden has successfully demonstrated teleportation using on-demand photons from quantum dots. In their paper published in the journal Science Advances, the group explains how they accomplished this feat and how it applies to future quantum communications networks.
Scientists and many others are very interested in developing truly quantum communications networks—it is believed that such networks will be safe from hacking or eavesdropping due to their very nature. But, as the researchers with this new effort point out, there are still some problems standing in the way. One of these is the difficulty in amplifying quantum signals. One way to get around this problem, they note, is to generate photons on-demand as part of a quantum repeater—this helps to effectively handle the high clock rates. In this new effort, they have done just that, using semiconductor quantum dots.
Prior work surrounding the possibility of using semiconductor quantum dots has shown that it is a feasible way to demonstrate teleportation, but only under certain conditions, none of which allowed for on-demand applications. Because of that, they have not been considered a push-button technology. In this new effort, the researchers overcame this problem by creating quantum dots that were highly symmetrical using an etching method to create the hole pairs in which the quantum dots develop. The process they used was called a XX (biexciton)–X (exciton) cascade. They then employed a dual-pulsed excitation scheme to populate the desired XX state (after two pairs shed photons, they retained their entanglement). Doing so allowed for the production of on-demand single photons suitable for use in teleportation. The dual pulsed excitation scheme was critical to the process, the team notes, because it minimized re-excitation.
The researchers tested their process first on subjective inputs and then on different quantum dots, proving that it could work across a broad range of applications. They followed that up by creating a framework that other researchers could use as a guide in replicating their efforts. But they also acknowledged that there is still more work to be done (mostly in raising the clock rates) before the process could be used in real-world applications. They expect it will be just a few more years.
MIT researchers have invented a way to fabricate nanoscale 3-D objects of nearly any shape. They can also pattern the objects with a variety of useful materials, including metals, quantum dots, and DNA.
“It’s a way of putting nearly any kind of material into a 3-D pattern with nanoscale precision,” says Edward Boyden, an associate professor of biological engineering and of brain and cognitive sciences at MIT.
Using the new technique, the researchers can create any shape and structure they want by patterning a polymer scaffold with a laser. After attaching other useful materials to the scaffold, they shrink it, generating structures one thousandth the volume of the original.
These tiny structures could have applications in many fields, from optics to medicine to robotics, the researchers say. The technique uses equipment that many biology and materials science labs already have, making it widely accessible for researchers who want to try it.
Boyden, who is also a member of MIT’s Media Lab, McGovern Institute for Brain Research, and Koch Institute for Integrative Cancer Research, is one of the senior authors of the paper, which appears in the Dec. 13 issue of Science. The other senior author is Adam Marblestone, a Media Lab research affiliate, and the paper’s lead authors are graduate students Daniel Oran and Samuel Rodriques.
Implosion fabrication
Existing techniques for creating nanostructures are limited in what they can accomplish. Etching patterns onto a surface with light can produce 2-D nanostructures but doesn’t work for 3-D structures. It is possible to make 3-D nanostructures by gradually adding layers on top of each other, but this process is slow and challenging. And, while methods exist that can directly 3-D print nanoscale objects, they are restricted to specialized materials like polymers and plastics, which lack the functional properties necessary for many applications. Furthermore, they can only generate self-supporting structures. (The technique can yield a solid pyramid, for example, but not a linked chain or a hollow sphere.)
To overcome these limitations, Boyden and his students decided to adapt a technique that his lab developed a few years ago for high-resolution imaging of brain tissue. This technique, known as expansion microscopy, involves embedding tissue into a hydrogel and then expanding it, allowing for high resolution imaging with a regular microscope. Hundreds of research groups in biology and medicine are now using expansion microscopy, since it enables 3-D visualization of cells and tissues with ordinary hardware.
By reversing this process, the researchers found that they could create large-scale objects embedded in expanded hydrogels and then shrink them to the nanoscale, an approach that they call “implosion fabrication.”
As they did for expansion microscopy, the researchers used a very absorbent material made of polyacrylate, commonly found in diapers, as the scaffold for their nanofabrication process. The scaffold is bathed in a solution that contains molecules of fluorescein, which attach to the scaffold when they are activated by laser light.
Using two-photon microscopy, which allows for precise targeting of points deep within a structure, the researchers attach fluorescein molecules to specific locations within the gel. The fluorescein molecules act as anchors that can bind to other types of molecules that the researchers add.
“You attach the anchors where you want with light, and later you can attach whatever you want to the anchors,” Boyden says. “It could be a quantum dot, it could be a piece of DNA, it could be a gold nanoparticle.”
“It’s a bit like film photography—a latent image is formed by exposing a sensitive material in a gel to light. Then, you can develop that latent image into a real image by attaching another material, silver, afterwards. In this way implosion fabrication can create all sorts of structures, including gradients, unconnected structures, and multimaterial patterns,” Oran says.
Once the desired molecules are attached in the right locations, the researchers shrink the entire structure by adding an acid. The acid blocks the negative charges in the polyacrylate gel so that they no longer repel each other, causing the gel to contract. Using this technique, the researchers can shrink the objects 10-fold in each dimension (for an overall 1,000-fold reduction in volume). This ability to shrink not only allows for increased resolution, but also makes it possible to assemble materials in a low-density scaffold. This enables easy access for modification, and later the material becomes a dense solid when it is shrunk.
“People have been trying to invent better equipment to make smaller nanomaterials for years, but we realized that if you just use existing systems and embed your materials in this gel, you can shrink them down to the nanoscale, without distorting the patterns,” Rodriques says.
Currently, the researchers can create objects that are around 1 cubic millimeter, patterned with a resolution of 50 nanometers. There is a tradeoff between size and resolution: If the researchers want to make larger objects, about 1 cubic centimeter, they can achieve a resolution of about 500 nanometers. However, that resolution could be improved with further refinement of the process, the researchers say.
The Earth is far more alive than previously thought, according to “deep life” studies that reveal a rich ecosystem beneath our feet that is almost twice the size of all the world’s oceans.
Despite extreme heat, no light, minuscule nutrition and intense pressure, scientists estimate this subterranean biosphere is teeming with between 15bn and 23bn tonnes of micro-organisms, hundreds of times the combined weight of every human on the planet.
Researchers at the Deep Carbon Observatory say the diversity of underworld species bears comparison to the Amazon or the Galápagos Islands, but unlike those places the environment is still largely pristine because people have yet to probe most of the subsurface.
“It’s like finding a whole new reservoir of life on Earth,” said Karen Lloyd, an associate professor at the University of Tennessee in Knoxville. “We are discovering new types of life all the time. So much of life is within the Earth rather than on top of it.”
The team combines 1,200 scientists from 52 countries in disciplines ranging from geology and microbiology to chemistry and physics. A year before the conclusion of their 10-year study, they will present an amalgamation of findings to date before the American Geophysical Union’s annual meeting opens this week.
Samples were taken from boreholes more than 5km deep and undersea drilling sites to construct models of the ecosystem and estimate how much living carbon it might contain.
The results suggest 70% of Earth’s bacteria and archaea exist in the subsurface, including barbed Altiarchaeales that live in sulphuric springs and Geogemma barossii, a single-celled organism found at 121C hydrothermal vents at the bottom of the sea.
One organism found 2.5km below the surface has been buried for millions of years and may not rely at all on energy from the sun. Instead, the methanogen has found a way to create methane in this low energy environment, which it may not use to reproduce or divide, but to replace or repair broken parts.
Lloyd said: “The strangest thing for me is that some organisms can exist for millennia. They are metabolically active but in stasis, with less energy than we thought possible of supporting life.”
Rick Colwell, a microbial ecologist at Oregon State University, said the timescales of subterranean life were completely different. Some microorganisms have been alive for thousands of years, barely moving except with shifts in the tectonic plates, earthquakes or eruptions.
Twin girls born earlier this month had their DNA altered to prevent them from contracting HIV, according to an Associated Press report. If confirmed, the births would signify the first gene-edited babies in human history—a stunning development that’s sparking an outcry from scientists and ethicists.
Professor He Jiankui of Shenzhen, China, made the announcement earlier today in Hong Kong, informing the Associated Press of his apparent achievement and releasing an accompanying video. He claims the twin girls were born earlier this month and that he altered their DNA with the CRISPR-cas9 gene-editing tool, which he did to confer a built-in immunity to the AIDS virus. The claim has yet to be independently confirmed, and the findings haven’t been published to a peer-reviewed journal; outside experts haven’t had an opportunity to corroborate the claims, or assess the efficacy or safety of the procedure.
A BBC article describes this news as “dubious,” but there’s reason to believe the claims could be true. Back in 2016, scientists in China used CRISPR to introduce a beneficial mutation that disables an immune-cell gene called CCR5, conferring immunity by knocking out a critical receptor, or mode of entry, for the HIV virus to infect a cell. The experiment showed that someday it might be possible to deliberately endow human DNA with this desirable mutation—the key word being “someday.” Immediately after the 2016 experiment, the scientists destroyed the embryos, saying more research will be required before modified embryos can be implanted in a mother’s womb.
Alarmingly, professor He has decided, quite unilaterally, to move ahead with this research, reportedly implanting the modified embryos into the mother’s womb—a step considered by most experts to be highly premature and reckless at this stage. Gene-editing of human embryos is sanctioned in the United States, but all embryos must be destroyed within a few days. A huge issue with this form of gene-editing is that it’s done on germline cells, which means introduced traits are heritable. Such is the case with these twins in China, who—if they are indeed genetically modified—will pass modified DNA down to any children they have. Scientists are still a long ways off from knowing if this procedure is effective and safe.
In this case, there’s good reason for doubt. The CCR5 gene is known to trigger offsetting conditions, such as a higher risk of contracting the West Nile Virus. Research suggests it also increases a person’s chance of dying from influenza. Also, CRISPR is a notoriously blunt instrument, and there’s no way of knowing if He’s procedure introduced knock-off effects, some of which wouldn’t be known until the girls reach maturity.
Details of the procedure are still scarce, such as the identity of the parents or where the research was conducted, but preliminary information acquired by AP is cause for concern.
The AP reports that CRISPR-cas9 gene editing was done during the in vitro fertilization, or IVF, stage. Several days later, the cells of the modified embryos were checked for signs of DNA editing. Of the 22 embryos edited, 11 were used in six implant attempts. Only one worked, resulting in the twin births. In all, some seven couples participated in the procedure.
Follow-up tests suggest one of the twins had just one copy of the intended gene alteration, while the other had both. Individuals with one copy of the mutated gene can still contract HIV, but they may have an increased ability to ward off the effects of the disease. Many experts say the procedure should not have been allowed to happen, but the decision to allow the implantation of the “partially” modified embryo was an even worse indiscretion, calling it a form of human experimentation.
Speaking to the AP, Dr. Kiran Musunuru, a University of Pennsylvania gene editing expert, said in this particular child, “there really was almost nothing to be gained in terms of protection against HIV and yet you’re exposing that child to all the unknown safety risks,” adding that the entire enterprise is “unconscionable” and “an experiment on human beings that is not morally or ethically defensible.”
Bioethicist Julian Savulescu from the University of Oxford described the experiment as “monstrous” in an interview with the BBC.
“Gene editing itself is experimental and is still associated with off-target mutations, capable of causing genetic problems early and later in life, including the development of cancer,” Savulescu told the BBC. “This experiment exposes healthy normal children to risks of gene editing for no real necessary benefit.”
If that’s not enough, this story gets even murkier.
He, who works at the Southern University of Science and Technology of China in Shenzhen, gave the university official notice of his experiment “long after he said he started it,” AP reports. It’s not clear if the participants understood the true nature of the experiment, which was described as an “AIDS vaccine development” program. The Shenzhen university said He’s work “seriously violated academic and ethics standards,” and an investigation is in the works. He, who owns two genetics companies in China, was reportedly assisted by U.S. scientist Michael Deem, who was an advisor to He when they worked together at Rice University in Houston. Deem also has stakes in both of He’s companies.
Condemnation of the procedure, however, is not universal among experts. Harvard geneticist George Church defended the alleged human gene-editing, telling AP that HIV is a “major and growing public health threat” and that the work done by He was “justifiable.”
A fascinating aspect of this alarming story is that He was not trying to cure a genetic disease. Rather, it was a deliberate attempt to endow humans with the capacity to ward off a future infection, namely one caused by the AIDS virus. In this sense, the procedure (if it happened in the way He is claiming), might be considered an enhancement rather than a therapy. As such, these girls may go down in history as the first enhanced humans produced by gene-editing.
Unfortunately, the brazen recklessness exhibited by He will now place a dark taint on that futuristic prospect. Yes, we may eventually use gene-editing to cure diseases and endow our species with new capacities—but such research cannot happen at the whim of rogue scientists.
EXPLORER, the world’s first medical imaging scanner that can capture a 3-D picture of the whole human body at once, has produced its first scans.
The brainchild of UC Davis scientists Simon Cherry and Ramsey Badawi, EXPLORER is a combined positron emission tomography (PET) and X-ray computed tomography (CT) scanner that can image the entire body at the same time. Because the machine captures radiation far more efficiently than other scanners, EXPLORER can produce an image in as little as one second and, over time, produce movies that can track specially tagged drugs as they move around the entire body.
The developers expect the technology will have countless applications, from improving diagnostics to tracking disease progression to researching new drug therapies.
The first images from scans of humans using the new device will be shown at the upcoming Radiological Society of North America meeting, which starts on Nov. 24th in Chicago. The scanner has been developed in partnership with Shanghai-based United Imaging Healthcare (UIH), which built the system based on its latest technology platform and will eventually manufacture the devices for the broader healthcare market.
“While I had imagined what the images would look like for years, nothing prepared me for the incredible detail we could see on that first scan,” said Cherry, distinguished professor in the UC Davis Department of Biomedical Engineering. “While there is still a lot of careful analysis to do, I think we already know that EXPLORER is delivering roughly what we had promised.
EXPLORER image showing glucose metabolism throughout the entire human body. This is the first time a medical imaging scanner has been able to capture a 3D image of the entire human body simultaneously. Credit: UC Davis and Zhongshan Hospital, Shanghai
Badawi, chief of Nuclear Medicine at UC Davis Health and vice-chair for research in the Department of Radiology, said he was dumbfounded when he saw the first images, which were acquired in collaboration with UIH and the Department of Nuclear Medicine at the Zhongshan Hospital in Shanghai.
“The level of detail was astonishing, especially once we got the reconstruction method a bit more optimized,” he said. “We could see features that you just don’t see on regular PET scans. And the dynamic sequence showing the radiotracer moving around the body in three dimensions over time was, frankly, mind-blowing. There is no other device that can obtain data like this in humans, so this is truly novel.”
