Physicists have, for the first time, demonstrated in an experiment that the decision whether two particles were in an entangled or in a separable quantum state can be made even after these particles have been measured and may no longer exist.
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Scientists and engineers at Arizona State University, in Tempe, have created the first lasers that can shine light over the full spectrum of visible colors. The device’s inventors suggest the laser could find use in video displays, solid-state lighting, and a laser-based version of Wi-Fi.
Although previous research has created red, blue, green and other lasers, each of these lasers usually only emitted one color of light. Creating a monolithic structure capable of emitting red, green, and blue all at once has proven difficult because it requires combining very different semiconductors. Growing such mismatched crystals right next to each other often results in fatal defects throughout each of these materials.
But now scientists say they’ve overcome that problem. The heart of the new device is a sheet only nanometers thick made of a semiconducting alloy of zinc, cadmium, sulfur, and selenium. The sheet is divided into different segments. When excited with a pulse of light, the segments rich in cadmium and selenium gave off red light; those rich in cadmium and sulfur emitted green light; and those rich in zinc and sulfur glowed blue.
The researchers grew this alloy in stages, carefully varying the temperature and other growth conditions over time. By controlling the interplay between the vapor, liquid, and solid phases of the different materials that made up this nano-sheet, they ensured that these different crystals could coexist.
The scientists can individually target each segment of the nano-sheet with a light pulse. Varying the power of the light pulses that each section received tuned how intensely they shone, allowing the alser to produce 70 percent more perceptible colors than the most commonly used light sources.
Lasers could be far more energy-efficient than LEDs: While LED-based lighting produces up to about 150 lumens per watt of electricity, lasers could produce more than 400 lumens per watt, says Cun-Zheng Ning, a physicist and electrical engineer at Arizona State University at Tempe who worked on the laser. In addition, he says that white lasers could also lead to video displays with more vivid colors and higher contrast than conventional displays.
Another important potential application could be "Li-Fi", the use of light to connect devices to the Interenet. Li-Fi ould be 10 times faster than today’s Wi-Fi, but "the Li-Fi currently under development is based on LEDs," Ning says. He suggests white-laser based Li-Fi could be 10 to 100 times faster than LED-based Li-Fi, because the lasers can encode data much faster than white LEDs.
In the future, the scientists plan to explore whether they can excite these lasers with electricity instead of with light pulses. They detailed their findingsonline 27 July in the journal Nature Nanotechnology.
Currently, all light-emitting diodes (LEDs) emit light of only one color, which is predefined during fabrication. So far, tuning the color of light produced by a single LED has never been realized, despite numerous attempts.
So it's quite remarkable that in a new study, scientists have demonstrated an LED that not only can be tuned to emit different colors of light, but can do so across nearly the entire visible spectrum: from blue (450-nm wavelength) to red (750-nm wavelength)—basically all colors but the darkest blues and violets.
The key to achieving the color-tunable LED is making it out of graphene—the same material that has led to groundbreaking research in a number of areas, from batteries to solar cells to semiconductors. Despite graphene's success in these areas, graphene-based LEDs have never been realized before now, making the new device the first-ever graphene-based LED in addition to being the first color-tunable LED.
Applications of the new LED include high-quality, color-tunable LED displays for TVs and mobile devices, color-tunable LED light fixtures, and the potential for a variety of future graphene-based photonic devices.
Lying at the interface of the GO and rGO is a special type of partially reduced GO that has optical, physical, and chemical properties that lie somewhere in between those of GO and rGO. The most important "blended" property of the interfacial layer is that it has a series of discrete energy levels, which ultimately allows for the emission of light at many different energies, or colors.
The occurrence of this property is especially interesting because, on their own, neither GO nor rGO (or any other known form of graphene, for that matter) can emit any light at all. This is because neither material has the right size "bandgap," which is the gap between two energy bands that electrons must jump across to conduct electricity or emit light. While GO has an extremely large bandgap, rGO has a zero bandgap.
Instead of having a bandgap somewhere in between GO and rGO, the partially reduced interfacial GO actually has many different intermediate bandgaps as a result of how the blending occurs—not as a smooth transition, but in the form of rGO nanoclusters embedded within the GO layer. Because these rGO nanoclusters are reduced to varying degrees at the interface, they exhibit variations in their energy levels and, consequently, in the color of emitted light. These energy levels can be easily modulated by changing the applied voltage or by chemical doping, which selectively stimulates a single color of luminescence and enables tuning of the LED's color.
"We found that a combination of GO and rGO can create a conductive and wide bandgap material," Ren told Phys.org. "It is commonly known that graphene does not have a bandgap. Therefore we were all surprised that our GO/rGO interface (a graphene-based system) can actually be luminescent."
Researchers have been able to develop a light-emitting device that is able to turn on and off as many as 90 billion times per second. The device could be a way to greatly speed up data transmission in computers.
Things like smartphone batteries currently power transistors by flipping electronics on and off billions of times per second. However, if microchips were able to use photons instead of electrons, computers might be able to operate a lot faster. To do this, however, engineers first had to create a light source that could be switched on and off extremely fast. While a laser might be able to do this, lasers are too power-hungry.
Researchers at Duke University, however, are getting closer to creating this kind of a light source. A team from the Pratt School of Engineering was able to push semiconductor quantum dots to emit light at over 90 gigahertz.
"This is something that the scientific community has wanted to do for a long time," said Duke assistant professor of electrical computer engineering, Maiken Mikkelsen, in an interview. "We can now start to think about making fast-switching devices based on this research, so there's a lot of excitement about this demonstration."
The new device was created using a laser that shines on a silver cube, after which the free electrons on the surface of the cube oscillate together in a wave. The oscillations create light themselves, which again reacts with the free electrons on the cube. This energy is called a plasmon.
By placing a sheet of gold only 20 atoms away, an energy field is created between the gold and silver cube. This field then interacts with quantum dots that are sandwiched between the gold and the silver cube, with the quantum dots then producing an emission of photons that can be turned on and off at more than 90 billion times per second.
"The eventual goal is to integrate our technology into a device that can be excited either optically or electrically," said Thang Hoang, another researcher at the laboratory. "That's something that I think everyone, including funding agencies, is pushing pretty hard for."
The team is now working to create one single photon source by only having one quantum dot between the silver cube and the gold sheet. The team is also trying to find the optimum placement and orientation of the quantum dots to create the fastest rate possible.
Argonne scientists used Mira to identify and improve a new mechanism for eliminating friction, which fed into the development of a hybrid material that exhibited superlubricity at the macroscale for the first time. ALCF researchers helped enable the groundbreaking simulations by overcoming a performance bottleneck that doubled the speed of the team’s code.
Coevolutionary interactions are thought to have spurred the evolution of key innovations and driven the diversification of much of life on Earth. However, the genetic and evolutionary basis of the innovations that facilitate such interactions remains poorly understood.
A group of scientists examined now the coevolutionary interactions between plants (Brassicales) and butterflies (Pieridae), and uncovered evidence for an escalating evolutionary arms-race. Although gradual changes in trait complexity appear to have been facilitated by allelic turnover, key innovations are associated with gene and genome duplications. Furthermore, the researchers show that the origins of both chemical defenses and of molecular counter adaptations were associated with shifts in diversification rates during the arms-race. These findings provide an important connection between the origins of biodiversity, coevolution, and the role of gene and genome duplications as a substrate for novel traits.
Via Kamoun Lab @ TSL
If you fell into a black hole, you might expect to die instantly. But in fact your fate would be far stranger than that. The instant you entered the black hole, reality would split in two. In one, you would be instantly incinerated, and in the other you would plunge on into the black hole utterly unharmed.
A black hole is a place where the laws of physics as we know them break down. Einstein taught us that gravity warps space itself, causing it to curve. So given a dense enough object, space-time can become so warped that it twists in on itself, burrowing a hole through the very fabric of reality.
A massive star that has run out of fuel can produce the kind of extreme density needed to create such a mangled bit of world. As it buckles under its own weight and collapses inward, space-time caves in with it. The gravitational field becomes so strong that not even light can escape, rendering the region where the star used to be profoundly dark: a black hole.
The outermost boundary of the hole is its event horizon, the point at which the gravitational force precisely counteracts the light's efforts to escape it. Go closer than this, and there's no escape.
The event horizon is ablaze with energy. Quantum effects at the edge create streams of hot particles that radiate back out into the universe. This is called Hawking radiation, after the physicist Stephen Hawking, who predicted it. Given enough time, the black hole will radiate away its mass, and vanish.
As you go deeper into the black hole, space becomes ever more curvy until, at the centre, it becomes infinitely curved. This is the singularity. Space and time cease to be meaningful ideas, and the laws of physics as we know them — all of which require space and time — no longer apply. What happens here, no one knows. Another universe? Oblivion? The back of a bookcase? It's a mystery.
So the laws of physics require that you be both outside the black hole in a pile of ashes and inside the black hole alive and well. Last but not least, there's a third law of physics that says information can't be cloned. You have to be in two places, but there can only be one copy of you.
Somehow, the laws of physics point us towards a conclusion that seems rather nonsensical. Physicists call this infuriating conundrum the black hole information paradox. Luckily, in the 1990s they found a way to resolve it.
Leonard Susskind realized that there is no paradox, because no one person ever sees your clone. Anne only sees one copy of you. You only see one copy of you. You and Anne can never compare notes. And there's no third observer who can see both inside and outside a black hole simultaneously. So, no laws of physics are broken.
Unless, that is, you demand to know which story is really true. Are you really dead or are you really alive? The great secret that black holes have revealed to us is that there is no really. Reality depends on whom you ask. There's Anne's really and there's your really. End of story.
Forget the Vulcan mind-meld of the Star Trek generation — as far as mind control techniques go, bacteria is the next frontier.
In a paper published today in Scientific Reports, which is part of the Nature Publishing Group, a Virginia Tech scientist used a mathematical model to demonstrate that bacteria can control the behavior of an inanimate device like a robot. “Basically we were trying to find out from the mathematical model if we could build a living microbiome on a nonliving host and control the host through the microbiome,” said Warren Ruder, an assistant professor of biological systems engineering in both the College of Agriculture and Life Sciences and the College of Engineering.
"We found that robots may indeed be able to function with a bacterial brain,” he said. For future experiments, Ruder is building real-world robots that will have the ability to read bacterial gene expression levels in E. coli using miniature fluorescent microscopes. The robots will respond to bacteria he will engineer in his lab.
On a broad scale, understanding the biochemical sensing between organisms could have far reaching implications in ecology, biology, and robotics. In agriculture, bacteria-robot model systems could enable robust studies that explore the interactions between soil bacteria and livestock. In healthcare, further understanding of bacteria’s role in controlling gut physiology could lead to bacteria-based prescriptions to treat mental and physical illnesses. Ruder also envisions droids that could execute tasks such as deploying bacteria to remediate oil spills.
The findings also add to the ever-growing body of research about bacteria in the human body that are thought to regulate health and mood, and especially the theory that bacteria also affect behavior.
The study was inspired by real-world experiments where the mating behavior of fruit flies was manipulated using bacteria, as well as mice that exhibited signs of lower stress when implanted with probiotics.
Ruder’s approach revealed unique decision-making behavior by a bacteria-robot system by coupling and computationally simulating widely accepted equations that describe three distinct elements: engineered gene circuits in E. coli, microfluid bioreactors, and robot movement.
The bacteria in the mathematical experiment exhibited their genetic circuitry by either turning green or red, according to what they ate. In the mathematical model, the theoretical robot was equipped with sensors and a miniature microscope to measure the color of bacteria telling it where and how fast to go depending upon the pigment and intensity of color.
The model also revealed higher order functions in a surprising way. In one instance, as the bacteria were directing the robot toward more food, the robot paused before quickly making its final approach — a classic predatory behavior of higher order animals that stalk prey.
Ruder’s modeling study also demonstrates that these sorts of biosynthetic experiments could be done in the future with a minimal amount of funds, opening up the field to a much larger pool of researchers.
Via Integrated DNA Technologies
It's the windiest place in the entire solar system – and these storms can be felt here on Earth.
The most extreme weather of all rarely gets a mention, even in the UK where we’re famous for our weather talk. Far above our heads the Earth is regularly hit by colossal, tsunami-like waves of scorching gas and savage, supersonic winds from space. The culprit for this extra-terrestrial weather is sat at the centre of our solar system. The familiar pictures of our Sun that portray a plain, incandescent orb, serenely holding the planets in place, couldn’t be further from the truth. The Sun is a rowdy place.
One of the most spectacular forms of space weather are Coronal Mass Ejections, where the Sun sporadically throws out billions of tons of hot gas and magnetic field into space. The Sun also generates its own wind, which ranges from “breezes” to “hurricanes”. It’s all on a much bigger scale though – even average solar winds are much more ferocious than anything we could ever experience, with speeds varying between a gentle 500,000 miles per hour to a gusty 2,000,000 mph. These winds carry with them a part of the Sun’s atmosphere, a million-℃ gas composed of highly energetic electrons, protons and alpha particles. The winds are accelerated along the sun’s outstretched, tentacle-like magnetic field, which originates deep under its surface and extends out past Earth to the edges of the solar system.
Being able to forecast the solar wind has its problems though. For example, we know they predominantly originate in darker, less dense patches of the Sun’s atmosphere known as coronal holes, however we are still unable to locate the other significant sources that must contribute to the wind. More importantly, we don’t have a clear explanation of how the winds are heated and accelerated.
In a recent study published in the journal Nature Communications, scientists investigate powerful magnetic waves, known as Alfvén waves, located in the regions where the solar wind originates. These waves cause the Sun’s magnetic field to violently sway back and forth at tens of thousands of miles per hour, transporting energy around the star’s atmosphere and out into space. It is this role as a magnetic energy carrier that means the Alfvén waves are often responsible for accelerating the solar wind to such monstrous speeds.
The researchers found that some of the necessary conditions exist for the waves to break down their energy to smaller scales and supply some of it to the wind (potentially via the interactions of the waves with particles) – something predicted for a couple of decades but never observed. Future studies of Alfvén waves should reveal how much energy they feed to the solar wind and may even allow us to forecast wind speeds.
The Search for Extraterrestrial Intelligence (SETI) project got a $100 million boost this week from Russian billionaire Yuri Milner. While this may seem like a lot of money to spend on a nearly impossible task, many astronomers welcome the investment. The cash will go some way to help save some observatories from closure and allow astronomers to continue to use the facilities for astrophysics research alongside SETI.
The “Breakthrough Listen” initiative, announced on July 20 at the Royal Society in London, will pay for giant radio telescopes at Green Bank in West Virginia, USA and the Parkes Observatory in Australia to scan the skies for signs of alien communications. The Lick Observatory’s optical telescope in San Jose, California will also join the search with the goal of scanning one million stars in our Milky Way galaxy along with a hundred other nearby galaxies. In the UK, the giant Lovell telescope at Jodrell Bank is also involved in SETI programs.
The funding, to be allocated over a decade, will pay for thousands of hours per year on these facilities compared to the tens of hours usually available to SETI scientists competing with other astronomical programmes. Frank Drake, one of the pioneers of modern SETI and a member of the Breakthrough Listen team, has described previous support for SETI research as patchy. The total worldwide support in recent years has been only about $500,000 from private gifts.
The telescopes will look for signals that cannot easily be explained by natural phenomena. A repeating signal could be be promising, although caution is needed; in 1967, Northern Irish astrophysicist Jocelyn Bell Burnell discovered mysterious regular and repeating pulses of radio emission. However the source of this emission, which she nicknamed Little Green Man 1 (LGM-1), turned out to be the first discovery of a pulsar – highly magnetised dense rotating neutron stars. These are recognised today as nature’s most accurate clocks and their discovery has certainly not been a waste of time.
The Breakthrough Listen project will scan stars for signals in the frequency range of 1 to 10 gigahertz (GHz), a band identified as a good choice for communication. That is because radio signals at these frequencies can travel through the universe and the Earth’s atmosphere relatively unimpeded. Light at lower frequencies is difficult to distinguish from the astrophysical background and higher frequencies are more easily absorbed by intervening gas in the cosmos and the Earth’s atmosphere.
The injection of cash is a lifeline for struggling observatories. The Parkes radio telescope, famous for beaming images of Armstrong’s moon walk, was threatened with closure by 2016, as the Australian government redirected funding into development of the upcoming Square Kilometer Array. The Greenbank telescope – the world’s largest steerable radio telescope – was under similar threat, with closure projected for 2017 unless new funding partners could be found.
These telescopes will now be trained on the sky and will gather vast amounts of data that will be made available through the SETI@home downloadable screen saver. This will allow the general public to help crunch the data in order to search for tell-tale signatures of intelligent extraterrestrial communications.
In 1959, two scientists – Philip Morrison and Guiseppe Cocconi – were the first to suggest technologically advanced alien civilisations might use electromagnetic radiation to communicate. Shortly after that, Frank Drake made the first search for alien radio signals using a previous generation of giant radio telescope in Greenbank and formulated an equation that suggested there could be ten civilisations in the Milky Way that we should be able to communicate with. The new funding will allow SETI scientists to thoroughly scan a wider range of frequencies for the next ten years, where previous efforts involved intermittent and irregular eavesdropping sessions. While scientists are hopeful that they will make a positive detection, a negative result from such a comprehensive search will be equally important. To date we have only searched a minute portion of the universe, so it is definitely worth continuing to do so. However, if we fail to find anything after the more detailed search, we may want to think about other ways of looking for alien life.
But to find a needle in a haystack, one has to look further than the first stalk of hay. The data will also be useful for astrophysicists interested in naturally occurring cosmic radio emission. Many new pulsars may be found along with enigmatic fast radio bursts – brief flashes of very intense radio emission that lasts for only a fraction of a second. Such bursts were discovered in 1997 with the Parkes telescope and their origin is still a mystery. Data from the listening project could help solve this mystery.
This is an exciting time to systematically survey a large number of stars. We know that planets are common around a range of different types of stars thanks to recent ground and space-based missions such as NASA’s Kepler satellite, which have revolutionised our ability to find other worlds. At the same time, solar system missions have found evidence of life-enabling water on planets other than Earth. While it may seem a big jump to finding intelligent and communicative extraterrestrials, this new investment may prove to be the turning point for SETI. In turn, plans are already in place to figure out how to respond if we are not alone – Milner plans to run a competition with a prize of $1m to find the best digital message to transmit back.
NASA's Mars rover Curiosity has detected Red Planet rocks similar to Earth's oldest continental crust. The discovery suggests that ancient Mars may have been more similar to ancient Earth than previously thought, researchers said. Observations of the Martian atmosphere suggest the Red Planet once had an ocean that covered a fifth of its surface. Most of that water was later lost to space.
With the help of a rock-zapping laser, NASA's Mars rover Curiosity has detected Red Planet rocks similar to Earth's oldest continental crust, researchers say. This discovery suggests that ancient Mars may have been more similar to ancient Earth than previously thought, scientists added. Earth is currently the only known planet whose surface is divided into continents and oceans. The continents are composed of a thick, buoyant crust rich in silica, whereas the seafloor is made up of comparatively thin, dense crust rich in silica-poor basaltic rock.
Previously, scientists had suggested that the continental crust may be unique to Earth. The silica-rich rock, the idea goes, resulted from complex activity in the planet's interior potentially related to the onset of plate tectonics — when the plates of rock making up Earth's exterior began drifting over the planet's mantle layer. In contrast, analyses of images snapped by Mars-orbiting spacecraft and studies of meteorites from the Red Planet previously suggested that the Martian crust was made up primarily of basaltic rock.
Now researchers have found that silica-rich rock much like the continental crust on Earth may be widespread at the site where Curiosity landed on Mars in August 2012.
"Mars is supposed to be a basalt-covered world," study lead author Violaine Sautter, a planetary scientist at France's Museum of Natural History in Paris, told Space.com. The findings are "quite a surprise," she added.
Sautter and her colleagues analyzed data from 22 rocks probed by Curiosity as the six-wheeled robot wandered ancient terrain near Gale Crater. This 96-mile-wide (154 kilometers) pit formed about 3.6 billion years ago when a meteor slammed into Mars, and the age of the rocks from this area suggests they could help shed light on the earliest period of the Red Planets, scientists said.
The 22 rocks the researchers investigated were light-colored, contrasting with the darker basaltic rock found in younger regions on Mars. They probed these rocks using the rock-zapping laser called ChemCamon Curiosity, which analyzes the light emitted by zapped materials to determine the chemistry of Martian rocks.
The scientists found these light-colored rocks were rich in silica. A number of these were similar in composition to some of Earth's oldest preserved continental crust. Sautter noted that recent orbiter and rover missions had also spotted isolated occurrences of silica-rich rock. The researchers suggest these silica-rich rocks might be widespread remnants of an ancient crust on Mars that was analogous to Earth's early continental crust and is now mostly buried under basalt.
The researchers added that the early geological history of Mars might be much more similar to that of Earth than previously thought. Future research could investigate whether the marked differences between Mars' smooth northern hemisphere and rough, heavily cratered southern hemisphere might be due to plate tectonics, Sautter said.
Stink bug mothers will lay darker or lighter eggs depending on how much light is reflecting off of a surface. The newly discovered adaptation is likely related to how some species of stink bugs are able to deposit their eggs on top of leaves, as the darker-colored eggs are better protected from UV radiation. Surprisingly, the eggs are not darkened by melanin, but by a previously unknown pigment. The findings, published July 23 in Current Biology, were driven by the curiosity of a University of Montreal PhD student, who uses the stink bugs as hosts for parasitic wasps.
Egg color variation exists in other species of animals, but how Podisus maculiventris (the spined solider stink bug, commonly found in fields and backyard gardens across North America) selectively controls egg pigmentation based on light perception is a new take on the trait. Certain birds and insects will lay subtly differently colored eggs, but typically in response to changes in age or diet, not a sensory cue from the environment.
"We suspect that these bugs possess some kind of physiological system that receives visual input from the environment and then modulates the application of a pigment in real time," says lead author and Paul Abram, who is working toward his PhD in entomology. "This is the first animal found that can selectively control egg color in response to environmental conditions, but we really doubt that it's the only one."
Abram was inspired to pursue this line of research by the crossword puzzle of a newspaper lining the bottom of a stink bug cage. He noticed that darker-colored eggs tended to appear on the black squares of the puzzle and the lighter-colored eggs on the light squares. He then replicated this observation in the lab using Petri dishes that were painted black or white. This was the tip-off of a relationship between surface brightness and stink bug egg color.
"We did a whole suite of experiments to determine whether females control egg color or whether eggs themselves are responding to the light," Abram says. "What we show is that color is likely influenced by how a female stink bug perceives the ratio of amount of light reflecting off of a surface to the amount of light coming down from above her head."
To understand why spined soldier bugs possess this ability, Abram conducted experiments on soybean plants to identify where eggs of different colors are laid. He found that darker eggs are laid on the tops of leaves and that lighter eggs are laid on the bottom of leaves. Since leaves are very good ultraviolet light filters--and knowing how pigmentation is used in other species--Abram suspected that the egg color adaptation is likely a form of sunscreen for eggs laid on tops of leaves. A follow-up experiment showed that, indeed, the dark pigment protected developing eggs from ultraviolet radiation.
It sounds like science fiction to suggest that every cell in the human body is occupied by a tiny genome-equipped organelle, with which we exist in symbiosis. But in actuality, eukaryotic life is dependent on mitochondria, which provide energy to the cell in the form of adenosine triphosphate (ATP). Over millennia, the genomes of mitochondria evolved under selection for minimal gene content, but researchers have been unable to determine why some but not all mitochondrial genes have been transfer
An international collaborative of researchers formed an interesting hypothesis regarding this phenomenon: The mitochondrial genome encodes hydrophobic membrane proteins which, if encoded in the nucleus, would be filtered by the signal recognition particle (SRP) and misdirected into the endoplasmic reticulum. The researchers conducted a study exploring their hypothesis and have published their results in the Proceedings of the National Academy of Sciences.
In order to predict if a protein would be targeted by SRP, the researchers calculated the free insertion energy of transmembrane proteins, which, if scored zero or less, were considered to be hydrophobic. Higher scores were rated marginally hydrophobic. If a transmembrane protein domain (TMD) scored hydrophobic and the length of its tail was longer than 120 amino acids, the researchers predicted it would be arrested by SRP and directed into the endoplasmic reticulum.
They expressed such proteins in cellular cytoplasm and were able to determine that they were, in fact, arrested by the SRP and directed to the endoplasmic reticulum. Further, the researchers observed that the mistargeting of these hydrophobic proteins into the soluble medium of the endoplasmic reticulum resulted in the formation of aberrant honeycomb structures similar to those observed during viral infections. "We conclude that genes for hydrophobic membrane proteins of more than 120 amino acids are likely retained in distinct organelle genomes to ensure a correct localization of these proteins and avoid transport to the endoplasmic reticulum," the authors write.
Thus, the researchers conclude, the selection against mistargeting hydrophobic proteins into the endoplasmic reticulum posed at least one major selective constraint on the retention of the mitochondrial genome. They bolster this finding by comparing it to similar membrane dynamics in the chloroplasts of plants.
Previous studies have suggested that one-third of mitochondrial proteins have evolved in response to the specific environmental constraints of different species. Most of these proteins are involved with transport, regulatory, and membrane functions. The results of the current study are consistent with these findings.
A persistent mystery has been the evidence that in rare cases, transfers of otherwise universal mitochondrial genes into the nuclear genome have occurred. The results of the current study present an explanation: These particular proteins demonstrate reduced hydrophobicity in those species in which the transfer took place.
Clinical applications include the development of methods to cure human mitochondrial genetic diseases, such as Leber's hereditary optic neuropathy. "These results resolve the long-standing question about why aerobic mitochondria and photosynthetic chloroplasts need a distinct compartmental genome, by and large, although other factors may be involved," the authors write.
All antimalarial drugs produced to date target the disease-causing parasite, but a new study in the Journal of Experimental Medicine shows that drugs which target host proteins are also a potential avenue for new interventions.
This study targets a protein that the most deadly malaria parasite, Plasmodium falciparum, relies on to invade human red blood cells. Targeting this human protein blocks an essential interaction, and can wipe out an established malaria infection in mice in less than three days.
Targeting host factors may help researchers overcome one of the biggest challenges to malaria control: drug resistance. Drug resistance arises due to genetic changes in the rapidly-evolving Plasmodium falciparum parasite, which, in Southeast Asia, has rendered one of the current front-line antimalarials, artemisinin, largely ineffective. Researchers are battling to find a solution before the resistant strains spread to other malaria endemic areas, including Africa, a region that accounts for 90 per cent of malaria deaths worldwide. By targeting host factors, rather than the parasite factors, the researchers believe that parasites are far less likely to develop resistance to the new drug.
"This counter-intuitive approach to malaria treatment leaves the parasite powerless," explains Dr. Zenon Zenonos, a first author from the Wellcome Trust Sanger Institute. "If the parasite can't bind to the surface of our red blood cells and invade, it can't reach the next stage in its lifecycle, so it dies. There's nothing the parasite can do to get round it, as the interaction is absolutely essential for infection to occur."
PfRH5, a protein required by the malaria parasite, needs to bind to basigin, a protein that is displayed on the outer surface of human red blood cells, for the cell to become infected. Blockade of the PfRH5-basigin interaction renders the parasite unable to enter red blood cells, and therefore the infection is wiped out.
"When we discovered the PfRH5-basigin interaction in 2011, we knew we had found a chink in the malaria parasite's armour, the question was how to exploit it," says Dr Gavin Wright, corresponding author from the Wellcome Trust Sanger Institute. "Using PfRH5 in a vaccine is one approach, but we were also interested to see if we could disrupt the interaction in the opposite direction rather than by conventionally targeting the parasite. This has significant advantages in preventing the ability of the parasite to develop resistance."
To study the likely human response to therapy, the antibody targeting basigin described in this study was tested in humanised mice that have had the majority of their immune cells and blood cells replaced with those from their human counterparts. In the mice, levels of infection fell to essentially undetectable levels within 72 hours of being treated with low doses of the antibody targeting basigin. Importantly, no side toxic effects were observed in the mouse models that were treated with the antibody in these experiments.
By now the thought of a 3D printed structure like a home or an apartment building doesn’t surprise most of us. After all, we know for a fact that several ambitious projects to construct such structures are currently underway. With that said, the majority of these buildings only utilize 3D printing for their exterior walls, as sort of a replacement for the use of concrete block or wood framing.
Recently, however, the United Arab Emirates National Innovation Committee has revealed a project which will take things a step or two further. The committee, as well as Shaikh Mohammad Bin Rashid Al Maktoum, UAE Vice-President and Prime Minister and Ruler of Dubai, wants to transform the UAE into a technological center of the world when it comes to architecture and design, and has set forth a plan to 3D print an entire office building. Not only will the exterior walls be printed, but so too will the interior walls, and furniture.
Leading this project will be WinSun Global, a company who has 3D printed an apartment building as well as a home late last year in China, as well as Gensler, Thornton Thomasetti, and Syska Hennessy, all which are leading engineering and architecture firms.
To print the 2,000 square foot building, engineers will use a 20-foot tall 3D printer, which will be assembled on the build site, located at a busy intersection right in the heart of Dubai. They will use Special Reinforced Concrete (SRC), Fiber Reinforced Plastic (FRP), and Glass Fiber Reinforced Gypsum (GRG) to fabricate the various structural and decorative components of the structure. Total construction time will be just a few weeks, while labor costs will be reduced by 50-80% and construction waste will be reduced between 30-60%.
Once completed, the building, will be used for a variety of purposes and will feature its very own 3D printing exhibition inside. This is the first major project undertaken by the ‘Museum of the Future‘, a museum that began construction earlier in the year, with the promise that 3D printing will be utilized in its creation.
Can the flap of a butterfly's wings in Brazil set off a tornado in Texas? This intriguing hypothetical scenario, commonly called "the butterfly effect," has come to embody the popular conception of a chaotic system, in which a small difference in initial conditions will cascade toward a vastly different outcome in the future.
Understanding and modeling chaos can help address a variety of scientific and engineering questions, and so researchers have worked to develop better mathematical definitions of chaos. These definitions, in turn, will aid the construction of models that more accurately represent real-world chaotic systems.
Now, researchers from the University of Maryland have described a new definition of chaos that applies more broadly than previous definitions. This new definition is compact, can be easily approximated by numerical methods and works for a wide variety of chaotic systems. The discovery could one day help advance computer modeling across a wide variety of disciplines, from medicine to meteorology and beyond. The researchers present their new definition in the July 28, 2015 issue of the journal Chaos.
"Our definition of chaos identifies chaotic behavior even when it lurks in the dark corners of a model," said Brian Hunt, a professor of mathematics with a joint appointment in the Institute for Physical Science and Technology (IPST) at UMD. Hunt co-authored the paper with Edward Ott, a Distinguished University Professor of Physics and Electrical and Computer Engineering with a joint appointment in the Institute for Research in Electronics and Applied Physics (IREAP) at UMD.
The study of chaos is relatively young. MIT meteorologist Edward Lorenz, whose work gave rise to the term "the butterfly effect," first noticed chaotic characteristics in weather models in the mid-20th century. In 1963, he published a set of differential equations to describe atmospheric airflow and noted that tiny variations in initial conditions could drastically alter the solution to the equations over time, making it difficult to predict the weather in the long term.
Mathematically, extreme sensitivity to initial conditions can be represented by a quantity called a Lyapunov exponent. This number is positive if two infinitesimally close starting points diverge exponentially as time progresses. Yet, Lyapunov exponents have limitations as a definition of chaos: they only test for chaos in particular solutions of a model, not in the model itself, and they can be positive even when the underlying model is considered too straightforward to be deemed chaotic.
University of California, Berkeley, researchers have discovered a much cheaper and easier way to target a hot new gene editing tool, CRISPR-Cas9, to cut or label DNA. The CRISPR-Cas9 technique, invented three years ago at UC Berkeley, has taken genomics by storm, with its ability to latch on to a very specific sequence of DNA and cut it, inactivating genes with ease. This has great promise for targeted gene therapy to cure genetic diseases, and for discovering the causes of disease.
The technology can also be tweaked to latch on without cutting, labeling DNA with a fluorescent probe that allows researchers to locate and track a gene among thousands in the nucleus of a living, dividing cell. The newly developed technique now makes it easier to create the RNA guides that allow CRISPR-Cas9 to target DNA so precisely. In fact, for less than $100 in supplies, anyone can make tens of thousands of such precisely guided probes covering an organism’s entire genome. The process, which they refer to as CRISPR-EATING – for “Everything Available Turned Into New Guides” – is reported in a paper to appear in the August 10 issue of the journal Developmental Cell.
As proof of principle, the researchers turned the entire genome of the common gut bacterium E. coli into a library of 40,000 RNA guides that covered 88 percent of the bacterial genome. Each RNA guide is a segment of 20 RNA base pairs: the template used by CRISPR-Cas9 as it seeks out complementary DNA to bind and cut.
These libraries can be employed in traditional CRISPR-Cas9 editing to target any specific DNA sequence in the genome and cut it, which is what researchers do to pin down the function of a gene: knock it out and see what bad things happen in the cell. This can help pinpoint the cause of a disease, for example. The process is called genetic screening and is done in batches: each of the thousands of probes is introduced into a single cell on a plate filled with hundreds of thousands of cells.
“We can make these libraries for a lot less money, which makes genetic screening potentially accessible in organisms less well studied,” such as those that have not yet had their genomes sequenced, said first author Andrew Lane, a UC Berkeley post-doctoral fellow.
But Lane and colleague Rebecca Heald, UC Berkeley professor of molecular and cell biology, developed the technology in order to track chromosomes in real-time in living cells, in particular during cell division, a process known as mitosis. This is part of a larger project by Heald to find out what regulates the size of the nucleus and other subcellular components as organisms grow from just a few cells to many cells.
“This technology will allow us to paint a whole chromosome and look at it live and really follow it in the nucleus during the cell cycle or as it goes through developmental transitions, for example in an embryo, to see how it changes in size and structure,” Heald said.
The new technique uses standard PCR (polymerase chain reaction) to generate many short lengths of DNA from whatever segment of DNA a researcher is interested in, up to and including an entire genome.
These fragments are then precisely snipped at a region called a PAM, which is critical to CRISPR binding. Simple restriction enzymes are then used to cut each piece 20 base pairs from the PAM end, generating the exact size of RNA guide that CRISPR uses in searching the genome for complementary sites. These guide RNAs are then easily incorporated into the CRISPR-Cas9 complex, yielding tens of thousands of probes for labeling or cutting DNA.
“By using the genome itself as a source for guide RNAs, their approach puts the creation of libraries that target contiguous regions in reach of almost any lab,” said Jacob Corn, managing and scientific director of the Innovative Genomics Initiative at UC Berkeley. “This could be very useful for genome imaging and certain kinds of screens, and I’m very interested to see how it enables biological discovery using Cas9 tools.”
The newly discovered blind white hairy-armed yeti crab, found to range in size from under an inch to around six inches in length, requires very specific conditions to live. So specific, and so uninhabitable for other creatures that scientists had to rely on a nifty piece of technology to obtain their research.
By controlling a remote-operated vehicle, researchers were able to go reach the hydrothermal vents of East Scotia Ridge and bring a few specimens back to the surface for further study.
The crabs live in a zone sandwiched between the extremely cold water that hovers just above freezing and the hydrothermal vents that emit water that can reach temperatures of more than 700 degrees Fahrenheit. They can't take the extreme cold or the extreme heat, so they live in that little pocket between, making their habitable space small and very specific. If they go too far into the cold or too far into the hot water, they die.
"We knew immediately that we'd found something tremendously novel and unique in hydrothermal vent research," said study leader Sven Thatje, an ecologist at the University of Southampton.
Because the yeti crab's habitat is so limited, they cluster together. Thatje described the crabs as "like beans in a jar, filling every available space." In fact, they found that around 700 individuals could occupy the same 11 square feet of space.
Unlike the males, the females don't always get to stay in that safety zone. Scientists speculate that some females went to the colder water to successfully lay their eggs. This isn't easy on the brooding mothers, according to the study, because they often can be seen with a deteriorated shell and highly worn setae, meaning that the bristly hair-like substance on their arms and chest shows damage.
And the news just gets worse for the females. "Females that move off-site do not feed; in fact, they starve," said Thatje. The researcher believes that once the females leave the warmth of the vents, they never make it back, lacking the strength to return to the group.
Since the crustaceans live so far below the surface, they can't access the sun like so many other species. Instead, they have to create their own food by growing bacteria on their setae, showing that those hairy arms aren't just ornamental. They are an integral part of the crab's design.
And, breaking tradition from their two relatives, the Kiwa puravida and K. hirsute, this new type of yeti crab also grow setae on their chests, prompting the researchers to playfully nickname the kiwa tyleri "the Hoff crab," referring to "Baywatch" star David Hasselhoff, who was famous for showing off his hairy chest.
Merging black holes can fling stars out of galaxies at near the speed of light.
Our own sun orbits the Milky Way’s center at an impressive 450,000 mph. Recently, scientists have discovered stars hurtling out of our galaxy at a couple million miles per hour. Could there be stars moving even faster somewhere out there? After doing some calculations, Harvard University astrophysicists Avi Loeb and James Guillochon realized that yes, stars could go faster. Much faster. According to their analysis, which they describe in two papers recently posted online, stars can approach light speed. The results are theoretical, so no one will know definitively if this happens until astronomers detect such stellar speedsters—which, Loeb says, will be possible using next-generation telescopes.
But it’s not just speed these astronomers are after. If these superfast stars are found, they could help astronomers understand the evolution of the universe. In particular, they give scientists another tool to measure how fast the cosmos is expanding. Moreover, Loeb says, if the conditions are right, planets could orbit the stars, tagging along for an intergalactic ride. And if those planets happen to have life, he speculates, such stars could be a way to carry life from one galaxy to another.
It all started in 2005 when a star was discovered speeding away from our galaxy fast enough to escape the gravitational grasp of the Milky Way. Over the next few years, astronomers would find several more of what became known as hypervelocity stars. Such stars were cast out by the supermassive black hole at the center of the Milky Way. When a pair of stars orbiting each other gets close to the central black hole, which weighs about four million times as much as the sun, the three objects engage in a brief gravitational dance that ejects one of the stars. The other remains in orbit around the black hole.
Loeb and Guillochon realized that if instead you had two supermassive black holes on the verge of colliding, with a star orbiting around one of the black holes, the gravitational interactions could catapult the star into intergalactic space at speeds reaching hundreds of times those of hypervelocity stars. Papers describing their analysis have been submitted to the Astrophysical Journal and the journal Physical Review Letters.
Loeb and Guillochon calculated that merging supermassive black holes would eject stars at a wide range of speeds. Only some would reach near light speed, but many of the rest would still be plenty fast. For example, Loeb says, the observable universe could have more than a trillion stars moving at a tenth of light speed, about 67 million miles per hour.
Because a single, isolated star streaking through intergalactic space would be so faint, only powerful future telescopes like the James Webb Space Telescope, planned for launch in 2018, would be able to detect them. Even then, telescopes would likely only see the stars that have reached our galactic neighborhood. Many of the ejected stars probably would have formed near the centers of their galaxies, and would have been thrown out soon after their birth. That means that they would have been traveling for the vast majority of their lifetimes. The star’s age could therefore approximate how long the star has been traveling. Combining travel time with its measured speed, astronomers can determine the distance between the star’s home galaxy and our galactic neighborhood.
If astronomers can find stars that were kicked out of the same galaxy at different times, they can use them to measure the distance to that galaxy at different points in the past. By seeing how the distance has changed over time, astronomers can measure how fast the universe is expanding.
Via Guillaume Decugis
For years, material scientists have been trying to figure out a way to give consumers broad access to the benefits of spider silk. As a naturally occurring supermaterial, spider silk is five times stronger than steel and more elastic than rubber bands, which suggests some amazing potential use cases, including bulletproof vests, biodegradable water bottles, and flexible bridge suspension ropes. But so far, every group that’s attempted to produce enough of the stuff to bring it to the mass market, from researchers to giant corporations, has pretty much failed.
The problem is there’s no way to get the silk from spiders themselves—creatures known to be territorial and cannibalistic, which doesn’t lend itself to raising them in groups. So people have had to resort to creative workarounds. They’ve tried raising genetically engineered silkworms, or inserting genes into microorganisms to express the needed spider silk protein. All of these efforts, however, have seen little success. Spider silk protein is complex, and even when experimenters are able to create fibers, these come out so fine that entirely new spinning systems need to be invented from scratch to turn the strands into thread. It doesn’t keep groups from trying though, and every few months or so, it seems, news of some spider silk breakthrough goes viral, only to quiet down after a few months. And consumers keep waiting.
But today, after five years of quiet operation, a startup called Bolt Threads has emerged to claim it’s made meaningful progress on the challenge. The Emeryville, California-based company grew out of the graduate school studies of three scientists from the University of California, San Francisco and UC Berkeley, and it has raised $40 million so far from such notable investors as Foundation Capital, Formation 8 and Founders Fund, as well as from government grants from institutions like the National Science Foundation. If its founders are to be believed, Bolt Threads may have solved the mystery—finally—of how to make spider silk commercially plausible.
“Basically, our mission from the beginning was to make a scalable amount of spider silk and bring that to consumers,” CEO Dan Widmaier tells WIRED. “It’s a problem that’s been around for a long time, and has been hampered entirely by technical challenges.” Widmaier knows it’s a bold claim. That’s why, he says, the company chose to fly under the radar for so long. “We decided to keep our heads down and try to solve the problem before we went out and started talking about all the cool things we can do with the technology,” he says. “Now, we’re ready to say we’re here.”
Widmaier says that generally speaking, what they do isn’t new in the world of biotechnology. The scientists genetically engineered a microorganism that can yield large quantities of silk protein through a yeast fermentation process—not just grams of silk protein, but metric tons. Then, using a proprietary mechanical system, a wet silk protein solution is manually squeezed through small extrusion holes and goes into a liquid bath that turns the stuff into solid fibers. While Widmaier won’t give away the minute specifications of how it all works, he does say that the extrusion process mimics the behavior of a spider’s spinneret—its silk-spinning organ. The naturally occurring spinning process has been the other key problem would-be spider silk producers have had difficulty mimicking in the past.
The result, Widmaier claims, is a technology that can artificially recreate the remarkably strong protein fibers spiders make. On top of that, he says, the fibers can even be tuned to possess different properties on demand: the researchers simply change the protein sequence on the platform to tweak the qualities of the material according to preference. Widmaier says they can make spider silk that’s stronger, stretchier, or waterproof, for example, depending on preference. “What we’ve learned is we could prod nature a little bit in the lab and engineer these new properties in,” says Widmaier.
Quantum technology based on light (photons) has great potential for radically new information technology based on photonic circuits. Up to now, the photons in quantum photonic circuits have behaved in the same way whether they moved forward or backward in a photonic channel. This has limited the ability to control the photons and thus build complex circuits for photonic quantum computers. Now researchers from the Niels Bohr Institute have discovered a new type of photonic channels, where back and forth are not equal distances! Such a system has been a missing component for building quantum photonic circuits on a large scale. The results are published in the scientific journal, Nature Nanotechnology.
"The smallest component of light is a photon and photons are very well suited for carrying information. A quantum circuit based on photons could contain far more information than is possible with current computer technology and the information could not be intercepted en route. So we are working to shape the future quantum technology based on photonics," explains Peter Lodahl, Professor and head of the research group Quantum Photonics at the Niels Bohr Institute at the University of Copenhagen.
Researchers at the Niels Bohr Institute have developed a photonic chip, in which a light source - a so-called quantum dot - is embedded. By shining light on the quantum dot using a laser, its electrons are excited, which then jump from one orbit to another and thus emit a single photon at a time. Light is normally emitted in all directions, but the photonic chip is constructed so that all of the photons are sent out through a photonic channel. So far so good. But the problem is that the photons are sent in both directions in the photonic channel and this limits the efficiency of the light source. This is a problem that grows, the bigger and more complex the circuit becomes.
"In our work to resolve the problem, we have now developed a new photonic channel where we can control the photons so that they are only sent in one direction. It is a fundamental new discovery, that you can get the emission of light in a photonic chip to take place in a manner not previously thought possible," explains Peter Lodahl.
The most exciting thing about the new photon channels is perhaps not even that the direction of the light emission depends on the spin of the quantum dots. It also turns out that a photon that enters from one end of the channel behaves differently than a photon that enters from the other end. Only when the photon moves in one direction does it interact with the quantum dot and this slows the photon a little bit, just as if the photon had travelled a little farther. In this system, back and forth are therefore not equal distances! And unequal distances are not unimportant, but on the contrary, extremely important.
"The photon is delayed a bit because it interacts with the quantum dot. We now have a number of new opportunities to control and design the interaction between a photon and a quantum dot, which is important for the development of quantum computers," explain Immo Söllner and Sahand Mahmoodian.
"We can control the state of the quantum dot and thereby determine the direction in which the photon is emitted and whether the light, which moves in one direction or the other, needs to be delayed. This is a completely new functionality that will have some practical advantages when we start constructing quantum networks, which are expected to have great potential for calculating difficult problems in chemistry and materials technology. Therefore, we have patented our discovery and are working towards commercialization," says Professor Peter Lodahl.
Despite sarcasm’s nasty reputation, new research finds that it can boost creativity and problem-solving in the workplace.
Despite being the lingua franca of the Internet, sarcasm isn’t known as a sophisticated form of wit or a conversational style that wins friends. From the Greek and Latin for “to tear flesh,” sarcasm has been called “hostility disguised as humor,” the contempt-laden speech favored by smart alecks and mean girls that’s best to avoid.
But new research by Francesca Gino of Harvard Business School, Adam Galinsky, the Vikram S. Pandit Professor of Business at Columbia Business School, and Li Huang of INSEAD, the European business school, finds that sarcasm is far more nuanced, and actually offers some important, overlooked psychological and organizational benefits.
“To create or decode sarcasm, both the expressers and recipients of sarcasm need to overcome the contradiction (i.e., psychological distance) between the literal and actual meanings of the sarcastic expressions. This is a process that activates and is facilitated by abstraction, which in turn promotes creative thinking,” said Gino via email.
While practitioners of sarcasm have long believed intuitively that the “mental gymnastics” it requires indicate “superior cognitive processes” at work, the authors say, it hasn’t been clear until now in which direction the causal link flowed, or that sarcasm boosted creativity in those receiving it, not just those dishing it out.
“Not only did we demonstrate the causal effect of expressing sarcasm on creativity and explore the relational cost sarcasm expressers and recipients have to endure, we also demonstrated, for the first time, the cognitive benefit sarcasm recipients could reap. Additionally, for the first time, our research proposed and has shown that to minimize the relational cost while still benefiting creatively, sarcasm is better used between people who have a trusting relationship,” said Gino.
In a series of studies, participants were randomly assigned to conditions labeled sarcastic, sincere, or neutral. As part of a simulated conversation task, they then expressed something sarcastic or sincere, received a sarcastic or sincere reply, or had a neutral exchange.
“Those in the sarcasm conditions subsequently performed better on creativity tasks than those in the sincere conditions or the control condition. This suggests that sarcasm has the potential to catalyze creativity in everyone,” said Galinsky via email. “That being said, although not the focus of our research, it is possible that naturally creative people are also more likely to use sarcasm, making it an outcome instead of [a] cause in this relationship.”
Of course, using sarcasm at work or in social situations is not without risk. It’s a communication style that can easily lead to misunderstanding and confusion or, if it’s especially harsh, bruised egos or acrimony. But if those engaged in sarcasm have developed mutual trust, there’s less chance for hurt feelings, the researchers found, and even if conflict arises, it won’t derail the creative gains for either party.
Lead author and PhD student Martin Ringbauer, said the study used photons – single particles of light – to simulate quantum particles traveling through time.
Closed timelike curves are among the most controversial features of modern physics. As legitimate solutions to Einstein’s field equations, they allow for time travel, which instinctively seems paradoxical. However, in the quantum regime these paradoxes can be resolved, leaving closed timelike curves consistent with relativity. The recent study of these systems therefore provides valuable insight into nonlinearities and the emergence of causal structures in quantum mechanics—essential for any formulation of a quantum theory of gravity. The authors experimentally simulate the nonlinear behavior of a qubit interacting unitarily with an older version of itself, addressing some of the fascinating effects that arise in systems traversing a closed timelike curve. These include perfect discrimination of non-orthogonal states and, most intriguingly, the ability to distinguish nominally equivalent ways of preparing pure quantum states. Finally, they examine the dependence of these effects on the initial qubit state, the form of the unitary interaction and the influence of decoherence.
UQ Physics Professor Tim Ralph said it was predicted in 1991 that time travel in the quantum world could avoid such paradoxes. “The properties of quantum particles are ‘fuzzy’ or uncertain to start with, so this gives them enough wiggle room to avoid inconsistent time travel situations,” he said.
Professor Ralph said there was no evidence that nature behaved in ways other than standard quantum mechanics predicted,but this had not been tested in regimes where extreme effects of general relativity played a role, such as near a black hole.
“Our study provides insights into where and how nature might behave differently from what our theories predict.” Examples of the intriguing possibilities in the presence of closed timelike curves include the violation of Heisenberg’s uncertainty principle, cracking of quantum cryptography and perfect cloning of quantum states.
Published in Nature Communications, the paper “Experimental Simulation of Closed Timelike Curves” includes Dr Matthew Broome, Dr Casey Myers, Professor Andrew White and Professor Timothy Ralph, all from The University of Queensland.
Researchers have demonstrated the feasibility of delivering an RNA that encodes for the protein alpha-1-antitrypsin (AAT)--which is missing or nonfunctional in the genetic disorder AAT deficiency--into cells in the laboratory, enabling the cells to produce highly functional AAT. This innovative approach to treating single gene disorders such as AAT deficiency offers and safe, simpler, and more cost-effective alternative to gene therapy or protein replacement, according to the authors of the study published in Nucleic Acid Therapeutics, a peer-reviewed journal from Mary Ann Liebert, Inc., publishers. The article is available free on the Nucleic Acid Therapeutics website until August 27, 2015.
In the article "In vitro Evaluation of a Novel mRNA-Based Therapeutic Strategy for the Treatment of Patients Suffering from Alpha-1-Antitrypsin Deficiency", Tatjana Michel, Stefanie Krajewski, and coauthors, University Medical Center, Tuebingen, Germany, produced a messenger RNA sequence that cells can translate to generate the AAT protein. The researchers assessed the stability and utility of the encapsulated RNA over time and evaluated the amount of AAT protein produced by the cells and how well the protein functioned. The data show no negative effects of the transfected RNA on the viability of the cells and no immune activation.
"The field is looking for advances in modified mRNA as a therapeutic strategy," says Executive Editor Graham C. Parker, PhD, The Carman and Ann Adams Department of Pediatrics, Wayne State University School of Medicine, Children's Hospital of Michigan, Detroit, MI. "Demonstrations such as this from the University Medical Center, Tuebingen, Germany, show real progress."
Research conducted in Okinawa, Japan, by graduate student Yu Miyazaki and associate professor James Davis Reimer from the University of the Ryukyus has found a very unusual new species of octocoral from a shallow coral reef in Okinawa, Japan. The new species can be considered a "living fossil", and is related in many ways to the unusual blue coral. The study was published in the open access journal ZooKeys.
A team of researchers with members from Washington University, Johns Hopkins School of Medicine, the Howard Hughes Medical Institute and the Polish Academy of Sciences has found that problems with RNA appear to be behind protein translation interruptions and that short segments of DNA may assist in regulating gene expression. They have published a paper describing their research and findings in the journal Science Advances.
Scientists have known for some time that the mechanism that controls protein translation, known as polyadenylate A aka, poly(A) is sometimes interrupted, causing degradation of messenger RNA (mRNA) and the proteins under development, leading to some ailments such as neurodegenerative diseases. Past research has suggested the problem lies with amino acids involved in the encoding, but now it appears that the problem is actually with the RNA itself—specifically strings of multiple adenosine (A) nucleotides.
In this new effort the team, noting that approximately 2 percent of genes in the human genome may be impacted, found that in studying bacterial ribosomes, that they were more likely to be interrupted on strings of lysines if they were encoded by AAA codons, as opposed to AAG codons. They showed that making shorter or longer runs of adenosine nucleotides, without modifying amino acid sequences, changed the protein output and also the stability of the mRNA. They noted also that doing so also sometimes led to the creation of what they termed "frameshifted" protein products.
The researchers also studied poly(A) tracks in human cells and found some as short as just nine basses long might influence gene expression. They discovered that poly(A) lowered the expression of protein in two different ways. The first was by halting translation, which led to degradation of the protein and mRNA itself. The second was when frameshifts occurred during translation, which led to early termination of the production of proteins.
The work by the team, and another also at Washington University looking into the impact of nucleotides on Poly(A) offer a fresh insight into the creation of disease-causing states in cells and by extension, possible ways to prevent it from happening, offering patients with such ailments hope of recovery.