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.

Source: Scientists Have ‘Hacked Photosynthesis’ In Search Of More Productive Crops : The Salt : NPR

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.”

Source: Breakthrough ultrasound treatment to reverse dementia moves to human trials

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.

Read more at: https://phys.org/news/2018-12-teleportation-on-demand-photons-quantum-dots.html#jCp

Source: Researchers demonstrate teleportation using on-demand photons from quantum dots

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.

Read more at: https://phys.org/news/2018-12-team-method-nanoscale.html#jCp

Source: Team invents method to shrink objects to the nanoscale

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.

Source: Scientists identify vast underground ecosystem containing billions of micro-organisms | Science | The Guardian

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.

[Associated Press and BBC]

Source: Reports of First Genetically Enhanced Babies Spark Outrage

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.

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.”

Source: Human images from world’s first total-body scanner unveiled

TimeTree is a public knowledge-base for information on the evolutionary timescale of life. Data from thousands of published studies are assembled into a searchable tree of life scaled to time. Three search modes are possible: Node Time – to find the divergence time of two species or higher taxa Timeline – to drill back through time and find evolutionary branches from the perspective of a single species Timetree – to build a timetree of a group of species or custom listTimepanels showing events in geological time and astronomical history are provided for comparison with timelines and timetrees. Results can be exported in different formats for additional analyses and publication.

Source: TimeTree :: The Timescale of Life

Two days before Hurricane Maria devastated Puerto Rico, the NASA-Japan Global Precipitation Measurement Core Observatory satellite captured a 3-D view of the storm. At the time Maria was a Category 1 hurricane. The 3-D view reveals the processes inside the hurricane that would fuel the storm’s intensification to a category 5 within 24 hours. For the first time in 360-degrees, this data visualization takes you inside the hurricane. The precipitation satellite has an advanced radar that measures both liquid and frozen water. The brightly colored dots show areas of rainfall, where green and yellow show low rates and red and purple show high rates. At the top of the hurricane, where temperatures are colder, blue and purple dots show light and heavy frozen precipitation. The colored areas below the dots show how much rain is falling at the surface.

For the first time, an international team of researchers has used a quantum computer to create artificial life—a simulation of living organisms that scientists can use to understand life at the level of whole populations all the way down to cellular interactions.

With the quantum computer, individual living organisms represented at a microscopic level with superconducting qubits were made to “mate,” interact with their environment, and “die” to model some of the major factors that influence evolution.

The new research, published in Scientific Reports on Thursday, is a breakthrough that may eventually help answer the question of whether the origin of life can be explained by quantum mechanics, a theory of physics that describes the universe in terms of the interactions between subatomic particles.

Modeling quantum artificial life is a new approach to one of the most vexing questions in science: How does life emerge from inert matter, such as the “primordial soup” of organic molecules that once existed on Earth?

[…]

Individuals were represented in the model using two qubits. One qubit represented the individual’s genotype, the genetic code behind a certain trait, and the other its phenotype, or the physical expression of that trait.

To model self-replication, the algorithm copied the expectation value (the average of the probabilities of all possible measurements) of the genotype to a new qubit through entanglement, a process that links qubits so that information is instantaneously exchanged between them. To account for mutations, the researchers encoded random qubit rotations into the algorithm that were applied to the genotype qubits.

The algorithm then modeled the interaction between the individual and its environment, which represented aging and eventually death. This was done by taking the new genotype from the self-replicating action in the previous step and transferring it to another qubit via entanglement. The new qubit represented the individual’s phenotype. The lifetime of the individual—that is, how long it takes the information to degrade or dissipate through interaction with the environment—depends on the information coded in this phenotype.

Finally, these individuals interacted with one another. This required four qubits (two genotypes and two phenotypes), but the phenotypes only interacted and exchanged information if they met certain criteria as coded in their genotype qubits.

Source: Researchers Created ‘Quantum Artificial Life’ For the First Time – Motherboard

Three US researchers have pulled off a sophisticated hoax by publishing fake research with ridiculous conclusions in sociology journals to expose what they see as ideological bias and a lack of rigorous vetting at these publications.

Seven of the 20 fake articles written by the trio were accepted by journals after being approved by peer-review committees tasked with checking the authors’ research.

A faux study claiming that “Dog parks are Petri dishes for canine ‘rape culture'” by one “Helen Wilson” was published in May in the journal Gender, Place and Culture.

The article suggests that training men like dogs could reduce cases of sexual abuse.

Faux research articles are not new: one of the most notable examples is physicist Alan Sokal, who in a 1996 article for a cultural studies journal wrote about cultural and philosophical issues concerning aspects of physics and math.

This time the fake research aims at mocking weak vetting of articles on hot-button social issues such as gender, race and sexuality.

The authors, writing under pseudonyms, intended to prove that academics in these fields are ready to embrace any thesis, no matter how outrageous, so long as it contributes to denouncing domination by white men.

“Making absurd and horrible ideas sufficiently politically fashionable can get them validated at the highest level of academic grievance studies,” said one of the authors, James Lindsay, in a video revealing the project.

Lindsay—that is his real name—obtained a doctorate in mathematics in 2010 from the University of Tennessee and has been fully dedicated to this project for a year and a half.

One of the published journal articles analyzes why a man masturbating while thinking of a woman without her consent commits a sexual assault.

Another is a feminist rewrite of a chapter of “Mein Kampf.”

Some articles—such as a study of the impact of the use of an anal dildo by heterosexual men on their transphobia —even claimed to rely on data such as interviews, which could have been verified by the journal gatekeepers.

For that “study” the authors claimed to have interviewed 13 men. In the dog article, the authors claimed to have examined the genitals of nearly 10,000 canines.

“If our project shows anything, it shows that what’s coming out of these disciplines cannot currently be trusted,” Lindsay told AFP.

Read more at: https://phys.org/news/2018-10-real-fake-hoodwinks-journals.html#jCp

Source: ‘Real’ fake research hoodwinks US journals

In the everyday world, events occur in a definite order—your alarm clock rings before you wake up, or vice versa. However, a new experiment shows that when fiddling with a photon, it can be impossible to say in which order two events occur, obliterating our common sense notion of before and after and, potentially, muddying the concept of causality. Known as a quantum switch, the setup could provide a useful new tool in budding quantum information technologies.

Quantum mechanics already torpedoes our notion that an object can be in only one place at a time. Thanks to the weirdness of quantum mechanics, a tiny particle like an electron can be in multiple places at once. The quantum switch achieves something similar for two events, A and B, showing that A can occur before B and B can occur before A.

“I’m very excited to see people realizing our idea with an actual experiment,” says Giulio Chiribella of the University of Oxford in the United Kingdom, one of the theorists who in 2009 first proposed the concept.

[…]

The quantum switch could have applications in budding technologies that, for example, manipulate and transmit information encoded in the quantum states of individual photons and other quantum particles. Such devices must pass particles through quantum channels, such as optical fibers, that invariably suffer from noise. But even if two such channels are too noisy to transmit quantum information, they could in principle be fashioned into a quantum switch to enable the information to flow, Jacquiline Romero, a quantum physicist and member of the Queensland team, says. “You introduce indefinite order and suddenly you can communicate,” she says. “That’s pretty cool!”

Source: Quantum chicken-or-egg experiment blurs the distinction between before and after | Science | AAAS

Quantum mechanics defies causal order, experiment confirms

An experiment has confirmed that quantum mechanics allows events to occur with no definite causal order. The work has been carried out by Jacqui Romero, Fabio Costa and colleagues at the University of Queensland in Australia, who say that gaining a better understanding of this indefinite causal order could offer a route towards a theory that combines Einstein’s general theory of relativity with quantum mechanics

In classical physics – and everyday life – there is a strict causal relationship between consecutive events. If a second event (B) happens after a first event (A), for example, then B cannot affect the outcome of A. This relationship, however, breaks down in quantum mechanics because the temporal spread of a particles’s wave function can be greater than the separation in time between A and B. This means that the causal order of A and B cannot be always be distinguished by a quantum particle such as a photon.

[…]

As well as making an experimental connection between relativity and quantum mechanics, the researchers point out that their quantum switch could find use in quantum technologies. “This is just a first proof of principle, but on a larger scale indefinite causal order can have real practical applications, like making computers more efficient or improving communication,” says Costa.

Quantum mechanics defies causal order, experiment confirms

Engineers and acousticians have known for years that the sound barriers bracketing America’s urban and suburban highways are only marginally useful, and that a variety of better technologies could be developed.

The problem: Nobody has an incentive to get them on the road.

“Walls are not a very effective solution,” said Robert Bernhard, vice president for research at the University of Notre Dame and an expert on noise control. Because the federal government pays for noise walls — and only noise walls — as part of highway expansion projects, he said, there is little incentive for researchers to keep testing and perfecting the alternatives.

Sound moves in not-so-mysterious ways, meaning that typical sound barriers have only limited effectiveness.

Visual: Wisconsin DOT

[…]

Even with the sound reduction, however, roadside residents are unlikely to hear crickets chirping. A dishwasher running in the next room is 50 dB, as are the ambient sounds of a laid-back city. The noise criteria aim to allow people to talk over their backyard picnic table, or shout at someone several feet away. “It’s not a situation where meeting the standard makes for a great backyard environment,” Bernhard said.

Of course, some of our ability to process sound is psychological: If people can see the tops of trucks over the wall they say it’s noisier, something people in the field call “psycho-coustics,” explained Bruce Rymer, a senior engineer at the California Department of Transportation. Just by ensuring a wall breaks that line of sight, “we achieve a reduction of 5 decibels,” said Mariano Berrios, environmental programs coordinator at FDOT.

But because noise travels in waves, not straight lines, sounds can and do go over the walls. This is why even with barriers standing 16 feet, homes several blocks away can hear the highway. Part of the sound wave is absorbed, part is reflected away from the wall, and part is transmitted through, Berrios explained. “Most of it goes above the barrier and gets diffracted, and gets to the receiver,” — that is, to a resident’s ears — he said.

This is especially problematic during certain weather conditions. When the consulting firm Bowlby & Associates, in Franklin, Tennessee, measured sounds around a highway in a yet-to-be-published study, they found that residents hundreds of feet from the highway could hear sounds some 5 decibels louder if the wind was blowing towards them, said Darlene D. Reiter, the firm’s president.

Weather, however, isn’t taken into account by the regulations. The noise model “assumes neutral conditions — no wind and no temperature effects — when in reality that happens only occasionally,” Reiter said. In the early morning, if the ground is cool but the air warms up, for instance, sound that would normally be pushed up is refracted downward, causing homes some 500 or 1,000 feet from the road to hear it loudly.

Source: On Highway Noise Barriers, the Science Is Mixed. Are There Alternatives?

a team of engineers at the Johns Hopkins University that has created an electronic skin. When layered on top of prosthetic hands, this e-dermis brings back a real sense of touch through the fingertips.

“After many years, I felt my hand, as if a hollow shell got filled with life again,” says the anonymous amputee who served as the team’s principal volunteer tester.

Made of fabric and rubber laced with sensors to mimic nerve endings, e-dermis recreates a sense of touch as well as pain by sensing stimuli and relaying the impulses back to the peripheral nerves.

“We’ve made a sensor that goes over the fingertips of a prosthetic hand and acts like your own skin would,” says Luke Osborn, a graduate student in biomedical engineering. “It’s inspired by what is happening in human biology, with receptors for both touch and pain.

“This is interesting and new,” Osborn said, “because now we can have a prosthetic hand that is already on the market and fit it with an e-dermis that can tell the wearer whether he or she is picking up something that is round or whether it has sharp points.”

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The work—published June 20 in the journal Science Robotics – shows it is possible to restore a range of natural, touch-based feelings to amputees who use prosthetic limbs. The ability to detect pain could be useful, for instance, not only in prosthetic hands but also in lower limb prostheses, alerting the user to potential damage to the device.

Source: New ‘e-dermis’ brings sense of touch, pain to prosthetic hands

No paper straws have been made in Britain for the last several decades. But that is about to change as a group of packaging industry veterans prepare to open a dedicated paper straw production line in Ebbw Vale, Wales, making hundreds of millions of straws a year for McDonald’s and other food companies as they prepare for a ban on plastic straws in the UK.

“We spotted a huge opportunity, and we went for it,” said Mark Varney, sales and marketing director of the newly created paper straw manufacturer Transcend Packaging. “When the BBC’s Blue Planet II was on the telly and the government started talking about the dangers of plastic straws, we saw a niche in the market.”

Varney and his business partners, all stalwarts of the packaging industry, watched as chains including Costa Coffee, Wetherspoons and Pizza Express announced plans to phase out plastic straws in favour of biodegradable paper.

“It is great that all these businesses are phasing out plastic straws, but the problem for them was where to get paper ones from,” Varney said. “Everyone is having to import them from China, and when you look at the carbon footprint of that it kind of defeats the exercise.”

So Varney and his partners set about opening what they reckon will be the only paper straw production plant in Europe. “We set up this company to give the the customers what they actually want: biodegradable paper straws made in the UK,” he said.

Transcend signed a deal last week to supply straws to 1,361 McDonald’s outlets from September. The deal was agreed before Transcend has made its first straw as the company is waiting on delivery of machines from China. McDonald’s uses 1.8m straws a day in the UK. The Northern Irish factory of the Finnish packaging company Huhtamaki will also supply McDonald’s but is understood to not yet have paper straw production capabilities.

Source: Paper straw factory to open in Britain as restaurants ditch plastic | Business | The Guardian

A team of scientists from Harvard University and the company Carbon Engineering announced on Thursday that they have found a method to cheaply and directly pull carbon-dioxide pollution out of the atmosphere.

[…]

the new technique is noteworthy because it promises to remove carbon dioxide cheaply. As recently as 2011, a panel of experts estimated that it would cost at least $600 to remove a metric ton of carbon dioxide from the atmosphere.

The new paper says it can remove the same ton for as little as $94, and for no more than $232. At those rates, it would cost between $1 and $2.50 to remove the carbon dioxide released by burning a gallon of gasoline in a modern car.

[…]

Their technique, while chemically complicated, does not rely on unprecedented science. In effect, Keith and his colleagues have grafted a cooling tower onto a paper mill. It has three major steps.First, outside air is sucked into the factory’s “contactors” and exposed to an alkaline liquid. These contactors resemble industrial cooling towers: They have large fans to inhale air from the outside world, and they’re lined with corrugated plastic structures that allow as much air as possible to come into contact with the liquid. In a cooling tower, the air is meant to cool the liquid; but in this design, the air is meant to come into contact with the strong base. “CO₂ is a weak acid, so it wants to be in the base,” said Keith.

Second, the now-watery liquid (containing carbon dioxide) is brought into the factory, where it undergoes a series of chemical reactions to separate the base from the acid. The liquid is frozen into solid pellets, slowly heated, and converted into a slurry. Again, these techniques have been borrowed from elsewhere in chemical industry: “Taking CO₂ out of a carbonate solution is what almost every paper mill in the world does,” Keith told me.

Finally, the carbon dioxide is combined with hydrogen and converted into liquid fuels, including gasoline, diesel, and jet fuel. This is in some ways the most conventional aspect of the process: Oil companies convert hydrocarbon gases into liquid fuels every day, using a set of chemical reactions called the Fischer-Tropsch process. But it’s key to Carbon Engineering’s business: It means the company can produce carbon-neutral hydrocarbons.

What does that mean? Consider an example: If you were to burn Carbon Engineering’s gas in your car, you would release carbon-dioxide pollution out of your tailpipe and into Earth’s atmosphere. But as this carbon dioxide came from the air in the first place, these emissions would not introduce any new CO₂ to the atmosphere. Nor would any new oil have to be mined to power your car.

Source: Climate Change Can Be Reversed by Turning Air Into Gasoline – The Atlantic

UCLA neuroscientists reported Monday that they have transferred a memory from one animal to another via injections of RNA, a startling result that challenges the widely held view of where and how memories are stored in the brain.

The finding from the lab of David Glanzman hints at the potential for new RNA-based treatments to one day restore lost memories and, if correct, could shake up the field of memory and learning.

[…]

Many scientists are expected to view the research more cautiously. The work is in snails, animals that have proven a powerful model organism for neuroscience but whose simple brains work far differently than those of humans. The experiments will need to be replicated, including in animals with more complex brains. And the results fly in the face of a massive amount of evidence supporting the deeply entrenched idea that memories are stored through changes in the strength of connections, or synapses, between neurons.

[…]

Glanzman’s experiments—funded by the National Institutes of Health and the National Science Foundation—involved giving mild electrical shocks to the marine snail Aplysia californica. Shocked snails learn to withdraw their delicate siphons and gills for nearly a minute as a defense when they subsequently receive a weak touch; snails that have not been shocked withdraw only briefly.

The researchers extracted RNA from the nervous systems of snails that had been shocked and injected the material into unshocked snails. RNA’s primary role is to serve as a messenger inside cells, carrying protein-making instructions from its cousin DNA. But when this RNA was injected, these naive snails withdrew their siphons for extended periods of time after a soft touch. Control snails that received injections of RNA from snails that had not received shocks did not withdraw their siphons for as long.

“It’s as if we transferred a memory,” Glanzman said.

Glanzman’s group went further, showing that Aplysia sensory neurons in Petri dishes were more excitable, as they tend to be after being shocked, if they were exposed to RNA from shocked snails. Exposure to RNA from snails that had never been shocked did not cause the cells to become more excitable.

The results, said Glanzman, suggest that memories may be stored within the nucleus of neurons, where RNA is synthesized and can act on DNA to turn genes on and off. He said he thought memory storage involved these epigenetic changes—changes in the activity of genes and not in the DNA sequences that make up those genes—that are mediated by RNA.

This view challenges the widely held notion that memories are stored by enhancing synaptic connections between neurons. Rather, Glanzman sees synaptic changes that occur during memory formation as flowing from the information that the RNA is carrying.

Source: Memory Transferred between Snails, Challenging Standard Theory of How the Brain Remembers – Scientific American

For the first time ever, scientists have identified the existence of a new DNA structure that looks more like a twisted, four-stranded knot than the double helix we all know from high school biology.

The newly identified structure, detailed Monday in the journal Nature Chemistry, could play a crucial role in how DNA is expressed.

Some research had previously suggested the existence of DNA in this tangled form, dubbed an i-motif, but it had never before been detected in living cells outside of the test tube. Researchers at the Garvan Institute of Medical Research in Australia, though, found that not only does the structure exist in living human cells, but it is even quite common.

Its existence in living cells indicates that the structure likely plays a significant role in cell biology. In the double helix, nitrogen bases of adenine (A) forms a base pair with thymine (T), and cytosine (C) forms a base pair with guanine (G). Base pairs are stacked on top of one another, with two strands of a sugar-phosphate backbone twisting around them to form an elegant, spiraling ladder. This structure plays an important role in protein synthesis.

The twisted knot structure only occurs in a relatively small region of a genome, like a knot in the helical double strands of DNA. In the twisted knot structure, Cs bind to Cs instead of to Gs.

This phenomenon was first observed in labs in the 1990s, but for a long time it seemed that the structure could only occur under acidic conditions that did not exist inside a living cell. More recent work has shown the knots could also occur in other environments. On a hunch, Garvan Institute researchers developed an antibody that could sniff out i-motifs in the genome and identify them, tagging them with an immunofluorescent glow. This allowed researchers to see how frequently and where these knots of DNA occur. They found that the i-motifs are could fold and unfold depending on the acidity of their surroundings, and that the codes were generally found in areas of the genome involved in whether or not a certain gene gets expressed. This suggests the i-motifs may be some kind of switch that can regulate gene expression.

Source: Forget the Double Helix—Scientists Discovered a New DNA Structure Inside Human Cells

In a step that could change the definition of death, researchers have restored circulation to the brains of decapitated pigs and kept the reanimated organs alive for as long as 36 hours.

The feat offers scientists a new way to study intact brains in the lab in stunning detail. But it also inaugurates a bizarre new possibility in life extension, should human brains ever be kept on life support outside the body.

The work was described on March 28 at a meeting held at the National Institutes of Health to investigate ethical issues arising as US neuroscience centers explore the limits of brain science.

During the event, Yale University neuroscientist Nenad Sestan disclosed that a team he leads had experimented on between 100 and 200 pig brains obtained from a slaughterhouse, restoring their circulation using a system of pumps, heaters, and bags of artificial blood warmed to body temperature.

Source: Researchers are keeping pig brains alive outside the body – MIT Technology Review

From dice to modern electronic circuits, there have been many attempts to build better devices to generate random numbers. Randomness is fundamental to security and cryptographic systems and to safeguarding privacy. A key challenge with random-number generators is that it is hard to ensure that their outputs are unpredictable^1,2,3. For a random-number generator based on a physical process, such as a noisy classical system or an elementary quantum measurement, a detailed model that describes the underlying physics is necessary to assert unpredictability. Imperfections in the model compromise the integrity of the device. However, it is possible to exploit the phenomenon of quantum non-locality with a loophole-free Bell test to build a random-number generator that can produce output that is unpredictable to any adversary that is limited only by general physical principles, such as special relativity^{1,2,3,4,5,6,7,8,9,10,11}. With recent technological developments, it is now possible to carry out such a loophole-free Bell test^12,13,14,22. Here we present certified randomness obtained from a photonic Bell experiment and extract 1,024 random bits that are uniformly distributed to within 10⁻¹². These random bits could not have been predicted according to any physical theory that prohibits faster-than-light (superluminal) signalling and that allows independent measurement choices. To certify and quantify the randomness, we describe a protocol that is optimized for devices that are characterized by a low per-trial violation of Bell inequalities. Future random-number generators based on loophole-free Bell tests may have a role in increasing the security and trust of our cryptographic systems and infrastructure.

Source: Experimentally generated randomness certified by the impossibility of superluminal signals | Nature

In brief: It’s called the interstitium, or a layer of fluid-filled pockets hemmed in by collagen and it can be found all over our bodies, from skin to muscles to our digestive system. The interstitium likely acts as a kind of shock absorber for the rest of our interior bits and bobs and the workings of the fluid itself could help explain everything from tumor growth to how cells move within our bodies. The authors stop short of saying “new organ,” but the word is certainly on everyone’s lips.

Is it just me, or are you feeling a bit of deja vu?

Well, maybe it’s just me, but that’s because I’ve been in this situation before. You see, just over a year ago, researchers announced that they’d discovered a different “new” organ — the mesentery. That particular collection of bodily tissue is a fan-shaped fold that helps hold our guts in place. It had been known about for centuries, but only recently discovered to be large and important enough to justify calling it an organ. It was to be the body’s 79th, but that number is entirely arbitrary.

As we discovered here at Discover, the definition of an organ is hardly settled (and we’re aware of what a church organ is, thankyouverymuch). As became apparent during the whole mesentery craze, there’s no real definition for what an organ actually is. And the human body doesn’t have 79 organs, or 80 organs, or 1,000 organs, because that number can change drastically depending on the definition. And you can bet scientists debate what an organ actually is.

“It’s a silly number,” said Paul Neumann, a professor of medicine at Dalhousie University in Canada and member of the Federative International Programme for Anatomical Terminology, in a Discover article from last year. “If a bone is an organ, there’s 206 organs right there. No two anatomists will agree on a list of organs in the body”

Calling the interstitium a new organ, then, is a bit of a stretch. It’s there, it’s certainly important, but we need a better idea of what an organ is before we can start labeling things as such.

There is a definition of sorts, but it’s got more wiggle room than your large intestine. An organ is composed of two or more tissues, is self-contained and performs a specific function, according to most definitions you get by Googling “what is an organ?” But there’s no governing body that explicitly determines what an organ is, and there’s no official definition. Things like skin, nipples, eyeballs, mesenteries and more have crossed into organ-dom and back throughout history as anatomists debated the definition.

Source: The Interstitium Is Important, But Don’t Call It An Organ (Yet)

On May 25, 1798, the HMS DeBraak was entering Delaware Bay when a squall struck without warning. The British ship that originally belonged to the Dutch capsized and sank, taking 34 sailors and a dozen Spanish prisoners down with it. Rumored to contain a hoard of gold and jewelry, the DeBraak became a popular target for treasure hunters in the years that followed. The wreck was finally discovered in 1986, lying under 80 feet of water at the mouth of the Delaware River. The team who found the ship attempted to raise it from its watery grave, resulting in one of the worst archaeological disasters in modern history. The event precipitated the passing of long-overdue laws designed to prevent something like this from ever happening again.

Source: Here’s What Protects Shipwrecks From Looters and Hacks

D

Doctors have taken a major step towards curing the most common form of blindness in the UK – age-related macular degeneration.

Douglas Waters, 86, could not see out of his right eye, but “I can now read the newspaper” with it, he says.

He was one of two patients given pioneering stem cell therapy at Moorfields Eye Hospital in London.

Cells from a human embryo were grown into a patch that was delicately inserted into the back of the eye.

Douglas, who is from London, developed severe age-related macular degeneration in his right eye three years ago.

[…]

The technique, published in Nature Biotechnology, starts with embryonic stem cells. These are a special type of cell that can become any other in the human body.

They are converted into the type of cell that makes up the retinal pigment epithelium and embedded into a scaffold to hold them in place.

The living patch is only one layer of cells thick – about 40 microns – and 6mm long and 4mm wide.

It is then placed underneath the rods and cones in the back of the eye. The operation takes up to two hours.

[…]

However, he does not call this a “cure” as completely normal vision is not restored.

[…]

So far the patients, the other is a woman in her early sixties, have maintained improved vision in the treated eye for a year.

They went from not being able to read with their affected eye at all, to reading 60 to 80 words per minute.

Eight more patients will take part in this clinical trial.

Doctors need to be sure it is safe. One concern is the transplanted cells could become cancerous, although there have been no such signs so far.

Source: Macular degeneration: ‘I’ve been given my sight back’ – BBC News

The ability to sense the spatial position and movements of one’s own body (kinesthetic sense) is critical for limb use. Because prostheses do not provide physical feedback during movement, amputees may not feel that they are in control of their bodily movements (sense of agency) when manipulating a prosthesis. Marasco et al. developed an automated neural-machine interface that vibrates the muscles used for control of prosthetic hands. This system instilled kinesthetic sense in amputees, allowing them to control prosthetic hand movements in the absence of visual feedback and increasing their sense of agency. This approach might be an effective strategy for improving motor performance and quality of life in amputees.

To effortlessly complete an intentional movement, the brain needs feedback from the body regarding the movement’s progress. This largely nonconscious kinesthetic sense helps the brain to learn relationships between motor commands and outcomes to correct movement errors. Prosthetic systems for restoring function have predominantly focused on controlling motorized joint movement. Without the kinesthetic sense, however, these devices do not become intuitively controllable. We report a method for endowing human amputees with a kinesthetic perception of dexterous robotic hands. Vibrating the muscles used for prosthetic control via a neural-machine interface produced the illusory perception of complex grip movements. Within minutes, three amputees integrated this kinesthetic feedback and improved movement control. Combining intent, kinesthesia, and vision instilled participants with a sense of agency over the robotic movements. This feedback approach for closed-loop control opens a pathway to seamless integration of minds and machines.

Source: Illusory movement perception improves motor control for prosthetic hands | Science Translational Medicine

Household cleaners, paints and perfumes have become substantial sources of urban air pollution as strict controls on vehicles have reduced road traffic emissions, scientists say.

Researchers in the US looked at levels of synthetic “volatile organic compounds”, or VOCs, in roadside air in Los Angeles and found that as much came from industrial and household products refined from petroleum as from vehicle exhaust pipes.

The compounds are an important contributor to air pollution because when they waft into the atmosphere, they react with other chemicals to produce harmful ozone or fine particulate matter known as PM2.5. Ground level ozone can trigger breathing problems by making the airways constrict, while fine airborne particles drive heart and lung disease.
Ammonia emissions rise in UK, as other air pollutant levels fall
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In Britain and the rest of Europe, air pollution is more affected by emissions from diesel vehicles than in the US, but independent scientists said the latest work still highlighted an important and poorly understood source of pollution that is currently unregulated.

“This is about all those bottles and containers in your kitchen cabinet below the sink and in the bathroom. It’s things like cleaners, personal products, paints and glues,” said Joost de Gouw, an author on the study at the University of Colorado in Boulder.

Source: Cleaning products a big source of urban air pollution, say scientists | Environment | The Guardian