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Entomologists are not like other people. Lucky enough to score a cool parasitic larva burrowing in your skin after a visit to Central America? The obvious thing to do is to rear your maggot out in your body until it’s an adult fly. For science.
In the last week, two entomologists proudly issued bot fly “birth” announcements of their little monsters. For one of them, it was his second try at rearing out the flesh-eating maggots to adults. His first unsuccessful attempt at bot fly rearing in 2013 did result in a research publication, though, so it wasn’t a wasted effort.
Piotr Nasrecki documented the entire process of his bot fly maggot rearing in a fascinating video. Yes, there is some blood. But you’ll also learn a lot about flies - and entomologists.
Below are excerpts from both scientists’ accounts of their maggoty pregnancies; I highly recommend reading both. Both Naskrecki and Wizen have written great explanations of the bot fly life cycle, with beautiful photos.
“Raising two dipteran [fly] children was an interesting experience. It was embarrassing on a few occasions, when both of my arms started bleeding profusely in public; painful at times, to the point of waking me up in the middle of the night; and inconvenient during the last stages of the flies’ development, when I had to tape plastic containers to my arms to make sure that I will not lose the emerging larvae. But other than those minor discomforts it was really not a big deal. Perhaps my opinion would have been different had the bot flies decided to develop in my eyelids, but I actually grew to like my little guests, and watched their growth with the same mix of pleasure and apprehension as when I watch the development of any other interesting organism under my care.”
Sitting at my dentist chair for 40 minutes and suffering through the shrill sound of the ultrasonic cleaner, I suddenly started to feel contractions from my chest. Oh, no. Not now. Is it really happening? If it happens now this will be a visit I will never forget. Am I getting into labor?… In the end, the contractions I felt at the dentist were a false alarm, and I could not feel anything when the larva eventually emerged.
Some physical principles have been considered immutable since the time of Isaac Newton: Light always travels in straight lines. No physical object can change its speed unless some outside force acts on it.
Not so fast, says a new generation of physicists: While the underlying physical laws haven’t changed, new ways of “tricking” those laws to permit seemingly impossible actions have begun to appear. For example, work that began in 2007 proved that under special conditions, light could be made to move along a curved trajectory — a finding that is already beginning to find some practical applications.
Now, in a new variation on the methods used to bend light, physicists at MIT and Israel’s Technion have found that subatomic particles can be induced to speed up all by themselves, almost to the speed of light, without the application of any external forces. The same underlying principle could also be used to extend the lifetime of some unstable isotopes, perhaps opening up new avenues of research in basic particle physics.
The findings, based on a theoretical analysis, were published in the journal Nature Physics by MIT postdoc Ido Kaminer and four colleagues at the Technion. The new findings are based on a novel set of solutions for a set of basic quantum-physics principles called the Dirac equations; these describe the relativistic behavior of fundamental particles, such as electrons, in terms of a wave structure. (In quantum mechanics, waves and particles are considered to be two aspects of the same physical phenomena). By manipulating the wave structure, the team found, it should be possible to cause electrons to behave in unusual and counterintuitive ways.
Imagine a micromotor fueled by stomach acid that can take a bubble-powered ride inside a mouse — and that could one day be a safer, more efficient way to deliver drugs or diagnose tumors for humans.
That’s the goal of a team of researchers at the University of California, San Diego. The experiment is the first to show that these micromotors can operate safely in a living animal, said Professors Joseph Wang and Liangfang Zhang of the NanoEngineering Department at the UC San Diego Jacobs School of Engineering.
Wang, Zhang and others have experimented with different designs and fuel systems for micromotors that can travel in water, blood and other body fluids in the lab. “But this is the first example of loading and releasing a cargo in vivo,” said Wang. “We thought it was the logical extension of the work we have done, to see if these motors might be able to swim in stomach acid.”
In the experiment, the mice ingested tiny drops of solution containing hundreds of the micromotors, which are 20 micrometers long. The motors become active as soon as they hit the stomach acid and zoom toward the stomach lining at a speed of 60 micrometers per second. They can self-propel like this for up to 10 minutes. This propulsive burst improved how well the cone-shaped motors were able to penetrate and stick in the mucous layer covering the stomach wall, explained Zhang. “It’s the motor that can punch into this viscous layer and stay there, which is an advantage over more passive delivery systems,” he said.
The researchers found that nearly four times as many zinc micromotors found their way into the stomach lining compared with platinum-based micromotors, which don’t react with and can’t be fueled by stomach acid.
The researchers explain that stomach acid reacts with the zinc body of the motors to generate a stream of hydrogen microbubbles that propel the motors forward. In their open-access study published in the journal ACS Nano, the researchers report that the motors lodged themselves firmly in the stomach lining of mice. As the zinc motors are dissolved by the acid, they disappear within a few days leaving no toxic chemical traces.
Wang said it may be possible to add navigation capabilities and other functions to the motors, to increase their targeting potential. Now that his team has demonstrated that the motors work in living animals, he noted, similar nanomachines soon may find a variety of applications including drug delivery, diagnostics, nanosurgery and biopsies of hard-to-reach tumors.
An ancient human skull fragment found in Israel may come from a close relative of the first modern humans to colonize Europe, researchers say.
Modern humans first arose between 150,000 and 200,000 years ago in Africa. Scientists have suggested the African exodus of modern humans started between 60,000 and 70,000 years ago, but much remains a mystery about this dispersal because of the scarcity of human fossils from this time.
Now, researchers have discovered a 55,000-year-old partial skull in Israel, from about the time when modern humans expanded out of Africa. The investigators say the anatomy of this fossil may offer clues about what the first modern human Europeans were like.
The fossil was discovered accidentally in 2008, when a bulldozer unearthed a cave during a construction project at the modern settlement of Manot, in northern Israel. The original entrance to the cave was sealed off by a rockfall about 30,000 years ago, making it a relatively pristine time capsule, according to co-lead study author Ofer Marder, an archaeologist at Ben-Gurion University of the Negev in Israel.
The first major haul of research from the European Space Agency’s Rosetta mission, published in seven papers1–7 in Science on 22 January, reveals a rich and diverse landscape on 67P/Churyumov–Gerasimenko, the most studied comet in history. The visible and infrared portrait of 67P’s surface, obtained by the Visible and Infrared Thermal Imaging Spectrometer (VIRTIS), shows an abundance of opaque, organic compounds, but very little water ice. This would be consistent with an origin for the comet in the distant Kuiper belt — beyond the orbit of Neptune — rather than closer to Jupiter, as its current orbit would suggest4.
NASA and Microsoft have teamed up to develop software called OnSight, a new technology that will enable scientists to work virtually on Mars using wearable technology called Microsoft HoloLens.
Astronomers at the Leiden Observatory, The Netherlands, and the University of Rochester, USA, have discovered that the ring system that they see eclipse the very young Sun-like star J1407 is of enormous proportions, much larger and heavier than the ring system of Saturn. The ring system - the first of its kind to be found outside our solar system - was discovered in 2012 by a team led by Rochester's Eric Mamajek.
A new analysis of the data, led by Leiden's Matthew Kenworthy, shows that the ring system consists of over 30 rings, each of them tens of millions of kilometers in diameter. Furthermore, they found gaps in the rings, which indicate that satellites ("exomoons") may have formed. The result has been accepted for publication in the Astrophysical Journal.
"The details that we see in the light curve are incredible. The eclipse lasted for several weeks, but you see rapid changes on time scales of tens of minutes as a result of fine structures in the rings," says Kenworthy. "The star is much too far away to observe the rings directly, but we could make a detailed model based on the rapid brightness variations in the star light passing through the ring system. If we could replace Saturn's rings with the rings around J1407b, they would be easily visible at night and be many times larger than the full moon."
"This planet is much larger than Jupiter or Saturn, and its ring system is roughly 200 times larger than Saturn's rings are today," said co-author Mamajek, professor of physics and astronomy at the University of Rochester. "You could think of it as kind of a super Saturn."
The astronomers analyzed data from the SuperWASP project - a survey that is designed to detect gas giants that move in front of their parent star. In 2012, Mamajek and colleagues at the University of Rochester reported the discovery of the young star J1407 and the unusual eclipses, and proposed that they were caused by a moon-forming disk around a young giant planet or brown dwarf.
In a third, more recent study also led by Kenworthy, adaptive optics and Doppler spectroscopy were used to estimate the mass of the ringed object. Their conclusions based on these and previous papers on the intriguing system J1407 is that the companion is likely to be a giant planet - not yet seen - with a gigantic ring system responsible for the repeated dimming of J1407's light.
The light curve tells astronomers that the diameter of the ring system is nearly 120 million kilometers, more than two hundred times as large as the rings of Saturn. The ring system likely contains roughly an Earth's worth of mass in light-obscuring dust particles.
University of Chicago scientists have experimentally observed for the first time a phenomenon in ultracold, three-atom molecules predicted by Russian theoretical physicist Vitaly Efimov in 1970.
In this quantum phenomenon, called geometric scaling, the triatomic molecules fit inside one another like an infinitely large set of Russian nesting dolls. “This is a new rule in chemistry that molecular sizes can follow a geometric series, like 1, 2, 4, 8…,” said Cheng Chin, professor in physics. “In our case, we find three molecular states in this sequence where one molecular state is about 5 times larger than the previous one.”
Chin and four members of his research group published their findings Dec. 9, 2014, in Physical Review Letters.
“Quantum theory makes the existence of these gigantic molecules inevitiable, provided proper—and quite challenging—conditions are created,” said Efimov, now at the University of Washington. The UChicago team observed three molecules in the series, consisting of one lithium atom and two cesium atoms in a vacuum chamber at the ultracold temperature of approximately 200 nanokelvin, a tiny fraction of a degree above absolute zero (minus 459.6 degrees Fahrenheit).
Given an infinitely large universe, the number of increasingly larger molecules in this cesium-lithium system also would extend to infinity. This remarkable idea stems from the exotic nature of quantum mechanics, which conforms to different laws of physics than those that govern the universe on a macroscopic scale.
“These are certainly exotic molecules,” said Shih-Kuang Tung, the postdoctoral scholar, now at Northwestern University, who led the project. Only under strict conditions could Tung and his colleagues see the geometric scaling in their Efimov molecules. It appears that neither two-atom nor four-atom molecules can achieve the Efimov state. “There’s a special case for three atoms,” Chin said.
Efimov’s reaction to the research was twofold: “First, I am amazed by the predictive power of the quantum theory,” he said. “Second, I am amazed by the skill of the experimentalists who managed to create those challenging conditions.”
Stunned researchers in Antarctica have discovered fish and other aquatic animals living in perpetual darkness and cold, beneath a roof of ice 740 meters thick. The animals inhabit a wedge of seawater only 10 meters deep, sealed between the ice above and a barren, rocky seafloor below—a location so remote and hostile the many scientists expected to find nothing but scant microbial life.
A team of ice drillers and scientists made the discovery after lowering a small, custom-built robot down a narrow hole they bored through the Ross Ice Shelf, a slab of glacial ice the size of France that hangs off the coastline of Antarctica and floats on the ocean. The remote water they tapped sits beneath the back corner of the floating shelf, where the shelf meets what would be the shore of Antarctica if all that ice were removed. The spot sits 850 kilometers from the outer edge of the ice shelf, the nearest place where the ocean is in contact with sunlight that allows tiny plankton to grow and sustain a food chain.
“I’m surprised,” says Ross Powell, a 63-year old glacial geologist from Northern Illinois University who co-led the expedition with two other scientists. Powell spoke with me via satellite phone from the remote location on the West Antarctic Ice Sheet, where 40 scientists, ice drillers and technicians were dropped by ski-mounted planes. “I’ve worked in this area for my whole career,” he says—studying the underbellies where glaciers flow into oceans. “You get the picture of these areas having very little food, being desolate, not supporting much life.” The ecosystem has somehow managed to survive incredibly far from sunlight, the source of energy that drives most life on Earth. The discovery provides insight into what kind of complex but undiscovered life might inhabit the vast areas beneath Antarctica’s ice shelves—comprising more than a million square kilometers of unexplored seafloor.
Theoretical physicists at Rice University have figured out how to custom-design graphene nanoribbons by controlling the conditions under which the nanoribbons are pulled apart to get the edges they need for specific mechanical and electrical properties, such as metallic (for chip interconnects, for example) or semiconducting (for chips).
The new research by Rice physicist Boris Yakobson and his colleagues appeared this month in the Royal Society of Chemistry journal Nanoscale. Perfect (pristine) graphene is conductive and looks like chicken wire, with each six-atom unit forming a hexagon, with edges that are zigzags like this: /\/\/\/\/\/\/\/\ .
Turning the hexagons 30 degrees makes the edges “armchairs,” with flat tops and bottoms held together by the diagonals, making the nanoribbons both semiconducting and more stable.
The researchers used density functional theory, a computational method to analyze the energetic input of every atom in a model system, to learn how thermodynamic and mechanical forces would accomplish the goal.
Their study revealed that heating graphene to 1,000 kelvin and applying a low but steady force along one axis will crack it in such a way that fully reconstructed 5–7 rings will form and define the new edges. Conversely, fracturing graphene with low heat and high force is more likely to lead to pristine zigzags.
Graphene has many desirable properties. Magnetism alas is not one of them. Magnetism can be induced in graphene by doping it with magnetic impurities, but this tends to disrupt graphene's electronic properties. Now physicists have found a way to induce magnetism in graphene while also preserving graphene's electronic properties. They have accomplished this by bringing a graphene sheet very close to a magnetic insulator -- an electrical insulator with magnetic properties.
Now a team of physicists at the University of California, Riverside has found an ingenious way to induce magnetism in graphene while also preserving graphene's electronic properties. They have accomplished this by bringing a graphene sheet very close to a magnetic insulator -- an electrical insulator with magnetic properties.
"This is the first time that graphene has been made magnetic this way," said Jing Shi, a professor of physics and astronomy, whose lab led the research. "The magnetic graphene acquires new electronic properties so that new quantum phenomena can arise. These properties can lead to new electronic devices that are more robust and multi-functional."
The finding has the potential to increase graphene's use in computers, as in computer chips that use electronic spin to store data. The magnetic insulator Shi and his team used was yttrium iron garnet grown by laser molecular beam epitaxy in his lab. The researchers placed a single-layer graphene sheet on an atomically smooth layer of yttrium iron garnet. They found that yttrium iron garnet magnetized the graphene sheet. In other words, graphene simply borrows the magnetic properties from yttrium iron garnet.
Magnetic substances like iron tend to interfere with graphene's electrical conduction. The researchers avoided those substances and chose yttrium iron garnet because they knew it worked as an electric insulator, which meant that it would not disrupt graphene's electrical transport properties. By not doping the graphene sheet but simply placing it on the layer of yttrium iron garnet, they ensured that graphene's excellent electrical transport properties remained unchanged.
In their experiments, Shi and his team exposed the graphene to an external magnetic field. They found that graphene's Hall voltage -- a voltage in the perpendicular direction to the current flow -- depended linearly on the magnetization of yttrium iron garnet (a phenomenon known as the anomalous Hall effect, seen in magnetic materials like iron and cobalt). This confirmed that their graphene sheet had turned magnetic
Orbiting and flyby probes of planets in our solar system have provided astronomers with a lot of information about the "surface" of the outer planets and the moons that orbit those planets. However, probing deep within their atmospheres requires penetrating the dense clouds to obtain meaningful data. Spacecraft weighing more than 300 kilograms fall too slowly, which has the net effect of reducing how much data they transmit because the relay needs to be further away.
Much smaller probes, made possible by the miniaturization of electronics, cameras and other instruments, would survive the fall through Jupiter's atmosphere for much longer without a parachute, according to John Moores of the Centre for Research in the Earth and Space Sciences (CRESS), at York University, Toronto, and colleagues there and at the University of Toronto. "Our concept shows that for a small enough probe, you can strip off the parachute and still get enough time in the atmosphere to take meaningful data while keeping the relay close and the data rate high," Moores explains.
Tiny satellites that weigh less than one kilogram, known as micro, nano and cube satellites, are already used in Earth orbit for a wide range of applications. There are limitations to how much solar power such small satellites can gather and regulations preclude the use of plutonium-powered thermoelectric generators. Micro satellites also require substantial infrastructure to gather their data signals. The team suggests that the presence of the European Space Agency (ESA) JUICE orbiter in the Jovian system set to begin in 2030 might facilitate a tandem mission that carried micro satellites to the planet. The mission platform has been named SMARA for SMAll Reconnaissance of Atmospheres and gets its name from the wind-borne fruit of the maple tree, the samara.
The SMARA mission may help address various aspects of planetary science. For instance, given that more than two-thirds of the total mass of the solar system, not including the Sun, forms Jupiter, its study is important for understanding the nature of the solar nebula from which our sun and all its planets formed. Additionally, Jupiter is under constant bombardment from small bodies, such as asteroids, and again, understanding its atmosphere would shed new light on the nature of these. The planet's atmosphere may even represent a historical record of impacts again providing information about the composition of the solar system.
Additionally, Jupiter's is the deepest of all the planetary atmospheres in the solar system and so offers an exciting laboratory for understanding flow dynamics, cloud microphysics and radiative transfer under conditions that are very different from those we see on Earth and the other terrestrial planets.
Also, Jupiter is the closest of the gas giants but there are now known to be many more similar planets orbiting other stars. Studying our nearest gas giant neighbor in close-up detail might allow us to understand the gas giants of distant stars with greater clarity. NASA's robotic Galileo probe, which orbited Jupiter in 1995, had no camera, so the swarm of microprobes would represent a first look at Jupiter with resolution greater than 15 kilometers per pixel.
An international team of 18 researchers provide new evidence of significant changes in four of the nine systems which regulate the resilience of the Earth. One of the systems which has been seriously affected is the nitrogen-phosphorus cycle which is essential to all life, and is particularly important to both food production and the maintenance of clean water.
"People depend on food, and food production depends on clean water," says Prof. Elena Bennett from McGill's School of the Environment who contributed the research on the nitrogen-phosphorus cycle to the study. "This new data shows that our ability both to produce sufficient food in the future and to have clean water to drink and to swim in are at risk."
The research fixing new planetary boundaries (which represent thresholds or tipping points beyond which there will be irreversible and abrupt environmental change) was published today in the journal Science. It suggests that changes to the Earth's climate, biosphere integrity (a concept covering loss of biodiversity and species extinction), and land-system (through deforestation for example) represent a risk for current and future societies. The fourth process which has become significantly compromised is the nitrogen-phosphorus cycle, which affects both the water we drink and our ability to produce food.
Nine planetary boundaries:
What exactly is the average lifetime of a technological civilization? 500 years? 50,000 years? Much depends upon the answer, for it helps us calculate the likelihood that other civilizations are out there, some of them perhaps making it through the challenges of adapting to technology and using it to spread into the cosmos. A high number would also imply that we too can make it through the tricky transition and hope for a future among the stars.
Sullivan, University of Washington, and Frank, University of Rochester, believe that even if the chances of a technological society emerging are as few as one in 1000 trillion, there will still have been 1000 instances of such societies undergoing transitions like ours in “our local region of the cosmos.” The authors refer to extraterrestrial civilizations as Species with Energy-Intensive Technology (SWEIT) and discuss issues of sustainability that begin with planetary habitability and extend to mass extinctions and their relation to today’s Anthropocene epoch, as well as changes in atmospheric chemistry, comparing what we see today with previous eras of climate alteration, such as the so-called Great Oxidation Event, the dramatic increase in oxygen levels (by a factor of at least 104) that occurred some 2.4 billion years ago.
Out of this comes a suggested research program that models SWEIT evolution and the evolution of the planet on which it arises, using dynamical systems theory as a theoretical methodology. As with our own culture, these ‘trajectories’ (development paths) are tied to the interactions between the species and the planet on which it emerges.
Each SWEIT’s history defines a trajectory in a multi-dimensional solution space with axes representing quantities such as energy consumption rates, population and planetary systems forcing from causes both “natural” and driven by the SWEIT itself. Using dynamical systems theory, these trajectories can be mathematically modeled in order to understand, on the astrobiology side, the histories and mean properties of the ensemble of SWEITs, as well as, on the sustainability science side, our own options today to achieve a viable and desirable future.
Using these modeling techniques could allow us to explore whether the atmospheric changes our own civilization is seeing are an expected outcome for technological societies based on the likely energy sources being used in the early era of technological development. Rapid changes to Earth systems are, the authors note, not a new phenomenon, but as far as we know, this is the first time where the primary agent of causation is watching it happen.
Sustainability emerges as a subset of the larger frame of habitability. Finding the best pathways forward involves the perspectives of astrobiology and planetary evolution, both of which imply planetary survival but no necessary survival for a particular species. Although we know of no extraterrestrial life forms at this time, this does not stop us from proceeding, because any civilization using energy to work with technology is also generating entropy, a fact that creates feedback effects on the habitability of the home planet that can be modeled.
The frilled shark is a fascinating and very strange fish that looks more like an eel than a shark. It has a wide head with a huge mouth and a long, slender body. Frilled sharks are sometimes called “living fossils” because they’re thought to be very similar to a prehistoric ancestor which lived millions of years ago. The mouth of the frilled shark is located at the end of the body instead of behind the tip of the snout as in most other sharks. The first pair of gill slits are especially long, extending from the sides of the body to underneath the throat. The gills have frilly structures on their edges, giving the shark its name.
Frilled sharks spend most of their time in deep water close to the sea bottom. Some people suggest that this shark is the basis of the sea serpent legends. It has the right shape to be mistaken for a sea serpent but it isn’t long enough, since it reaches a maximum length of only just under two meters.
Two living species of frilled sharks have been discovered. We know more about Chlamydoselachus anguineus, known simply as the “frilled shark”, than about the African frilled shark, Chlamydoselachus africana. Even so, there are lots of unanswered questions about the lives of these fish.
The frilled shark has a wide range in both the Pacific and the Atlantic Oceans, but it's found in only scattered patches in these areas. It may live in water as deep as 1000 to 1500 meters below the ocean surface, but it's usually located at depths between 500 and 1000 meters. In some Japanese waters frilled sharks have been found at depths between 50 and 200 meters.
The frilled shark is said to have an "ovoviviparous" method of reproduction, like many other sharks. The eggs are retained in the female's body instead of being laid. The embryos feed on the egg yolk inside the eggs. The eggs hatch inside the female's body and the pups are born live.
The frilled shark is believed to have a slow metabolism, since it lives mainly in cold, deep water. The development of the pups is also slow. It's thought that a three and a half year gestation period may be needed, which would be the longest of any vertebrate. Around six pups are born on average, although the number ranges from two to fifteen. In Japanese waters, and perhaps in other areas too, frilled sharks breed at any time of the year.
Frustrated with a lack of international action to address climate change and shrink nuclear arsenals, The Bulletin of the Atomic Scientists decided to push the minute hand of its iconic Doomsday Clock to 11:57.
It's the first time the clock hands have moved in three years; since 2012, the clock had been fixed at 5 minutes to symbolic doom, midnight. The Bulletin of the Atomic Scientists doesn't use the clock to make any real doomsday predictions. Rather, the clock is a visual metaphor to warn the public about how close the world is to a potentially civilization-ending catastrophe. Each year, the magazine's board analyzes threats to humanity's survival to decide where the Doomsday Clock's hands should be set.
Experts on the board said they felt a sense of urgency this year because of the world's ongoing addiction to fossil fuels, procrastination with enacting laws to cut greenhouse gas emissions and slow efforts to get rid of nuclear weapons.
Sharon Squassoni, a board member and director of the Proliferation Prevention Program at the Center for Strategic and International Studies, said nuclear disarmament efforts have "ground to a halt" and many nations are expanding, not scaling back, their nuclear capabilities. Russia is upgrading its nuclear program, India plans to expand its nuclear submarine fleet, and Pakistan has reportedly started operating a third plutonium reactor, Squassoni said. She also said the United States has good rhetoric on nuclear nonproliferation, but at the same time is in the midst of a $335 billion overhaul of its nuclear program.
"The risk from nuclear weapons is not that someone is going to press the button, but the existence of these weapons costs a lot of time, effort and money to keep them secure," Squassoni said, adding that there have been troubling safety discrepancies reported in recent years at power plants. The Bulletin of the Atomic Scientists was founded in 1945 by scientists who created the atomic bomb as part of the Manhattan Project and wanted to raise awareness about the dangers of nuclear technology.
The Doomsday Clock first appeared on a cover of the magazine in 1947, with its hands set at 11:53 p.m. The clock's hands shifted quite a bit over the following seven decades. They were closest to midnight in 1953, set at 11:58 p.m., after both the United States and the Soviet Union conducted their first tests of the hydrogen bomb. The clock's hands were pushed all the way back to 11:43 p.m., 17 minutes to midnight, in December 1991, after the world's superpowers signed the Strategic Arms Reduction Treaty, which at the time, seemed like a promising move toward nuclear disarmament.
Ever since Einstein proposed his special theory of relativity in 1905, physics and cosmology have been based on the assumption that space looks the same in all directions -- that it's not squeezed in one direction relative to another. A new experiment by physicists used partially entangled atoms -- identical to the qubits in a quantum computer -- to demonstrate more precisely than ever before that this is true: to one part in a billion billion.
The classic experiment that inspired Albert Einstein was performed in Cleveland by Albert Michelson and Edward Morley in 1887 and disproved the existence of an "ether" permeating space through which light was thought to move like a wave through water. What it also proved, said Hartmut Häffner, a UC Berkeley assistant professor of physics, is that space is isotropic and that light travels at the same speed up, down and sideways.
"Michelson and Morley proved that space is not squeezed," Häffner said. "This isotropy is fundamental to all physics, including the Standard Model of physics. If you take away isotropy, the whole Standard Model will collapse. That is why people are interested in testing this."
The Standard Model of particle physics describes how all fundamental particles interact, and requires that all particles and fields be invariant under Lorentz transformations, and in particular that they behave the same no matter what direction they move.
Häffner and his team conducted an experiment analogous to the Michelson-Morley experiment, but with electrons instead of photons of light. In a vacuum chamber he and his colleagues isolated two calcium ions, partially entangled them as in a quantum computer, and then monitored the electron energies in the ions as Earth rotated over 24 hours.
If space were squeezed in one or more directions, the energy of the electrons would change with a 12-hour period. It didn't, showing that space is in fact isotropic to one part in a billion billion (1018), 100 times better than previous experiments involving electrons, and five times better than experiments like Michelson and Morley's that used light.
The results disprove at least one theory that extends the Standard Model by assuming some anisotropy of space, he said.
Häffner and his colleagues, including former graduate student Thaned Pruttivarasin, now at the Quantum Metrology Laboratory in Saitama, Japan, will report their findings in the Jan. 29 issue of the journal Nature.
A Sun-like star with orbiting planets, dating back to the dawn of the Galaxy, has been discovered by an international team of astronomers. At 11.2 billion years old, it is the oldest star with Earth-sized planets ever found and proves that such planets have formed throughout the history of the Universe.
The discovery, announced on 28 January (AEDT) in the Astrophysical Journal, used observations made by NASA's Kepler satellite. The scientific collaboration was led by the University of Birmingham and contributed to by the University of Sydney.
The star, named Kepler-444, hosts five planets smaller than Earth, with sizes varying between those of Mercury and Venus. "We've never seen anything like this -- it is such an old star and the large number of small planets make it very special," said Dr Daniel Huber from the University's School of Physics and an author on the paper. "It is extraordinary that such an ancient system of terrestrial-sized planets formed when the universe was just starting out, at a fifth its current age. Kepler-444 is two and a half times older than our solar system, which is only a youthful 4.5 billion years old.
"This tells us that planets this size have formed for most of the history of the universe and we are much better placed to understand exactly when this began happening." Dr Tiago Campante, the research leader from the University of Birmingham said, "We now know that Earth-sized planets have formed throughout most of the Universe's 13.8-billion-year history, which could provide scope for the existence of ancient life in the Galaxy."
Together with their international colleagues the University's astronomy team used asteroseismology to determine the age of the star and planets. This technique measures oscillations -- the natural resonances of the host star caused by sound waves trapped within it.
They lead to miniscule changes or pulses in the star's brightness and allow researchers to measure its diameter, mass, and age. The presence and size of the planets is detected by the dimming that occurs when the planets pass across the face of the star. This fading in the intensity of the light received from the star enables scientists to accurately measure the sizes of the planets relative to the size of the star.
"When asteroseismology emerged about two decades ago we could only use it on the Sun and a few bright stars, but thanks to Kepler we can now apply the technique to literally thousands of stars. Asteroseismology allows us to precisely measure the radius of Kepler-444 and hence the sizes of its planets. For the smallest planet in the Kepler-444 system, which is slightly larger than Mercury, we measured its size with an uncertainty of only 100km," Dr Huber said.
A study led by the National University of Singapore (NUS) found that attaching chemotherapy drug Epirubicin to nanodiamonds effectively eliminates chemoresistant cancer stem cells. The findings were first published online in ACS Nano, the official journal of the American Chemical Society, in December 2014.
The research team, led by Assistant Professor Edward Chow, Junior Principal Investigator at the Cancer Science Institute of Singapore (CSI Singapore) at NUS, demonstrated the use of nanotechnology to repurpose existing chemotherapy drugs as effective agents against chemoresistant cancer stem cells. Chemoresistance, which is the ability of cancer cells to escape chemotherapy treatment, is a primary cause of treatment failure in cancer. Cancer stem cells, a type of cancer cell which initiates the formation of tumours, are commonly found to be more resistant to chemotherapy than the rest of the bulk tumour, which can lead to cancer recurrence following chemotherapy treatment. As such, there is intense interest in developing new drugs or treatment strategies that overcome chemoresistance, particularly in cancer stem cells.
In this study, widely-used chemotherapy drug Epirubicin was attached to nanodiamonds, carbon structures with a diameter of about five nanometres, to develop a nanodiamond-Epirubicin drug delivery complex (EPND). The researchers found that while both standard Epirubicin as well as EPND were capable of killing normal cancer cells, only EPND was capable of killing chemoresistant cancer stem cells and preventing secondary tumour formation in xenograft models of liver cancer.
Compared to other approaches such as combinatorial therapy of chemotherapy drugs with inhibitors of chemoresistance pathways, delivery of existing chemotherapy drugs with nanomaterials, in this case nanodiamonds, provide a broader range of protection in a package that is both safer and more effective. The study showed that delivery of Epirubicin by nanodiamonds resulted in a normally lethal dosage of Epirubicin becoming a safe and effective dosage. As such, delivery of chemotherapy drugs by nanodiamonds not only enables enhanced killing of chemoresistant cancer stem cells, but may be a useful alternative for patients who cannot tolerate the toxic side effects of standard chemotherapy drugs.
Furthermore, the versatility of the nanodiamond-based drug delivery platform opens up the possibility of future applications of nanodiamonds such as the addition of other similar drugs as well as active targeting components such as antibodies or peptides against tumour cell surface proteins for targeted drug release. In addition, the application of a nanodiamond-drug delivery system is not limited to liver cancer. It offers a promising approach to treating a broad range of difficult cancers, particularly those driven by chemoresistant cancer stem cells. In collaboration with Professor Dean Ho at the University of California Los Angeles and Professor Li Jianzhong at Peking University, Asst Prof Chow's group is working towards completing preclinical work on anthracycline delivery by nanodiamonds and hope to begin clinical trials in the near future.
An international team of scientists has constructed the first germanium-tin* semiconductor laser for CMOS silicon chips. By replacing copper wires with optical transmission, the new device promises higher-speed data transmission on computer chips at a fraction of the energy.
Transferring data between multiple cores and between logic elements and memory cells is a key bottleneck in fast-developing computer technology. “Signal transmission via copper wires limits the development of larger and faster computers due to the thermal load and the limited bandwidth of copper wires,” explains Prof. Detlev Grützmacher, Director at the Forschungszentrum Jülich Peter Grünberg Institute. “The clock signal alone uses up to 30% of the energy, which can be saved through optical transmission.”
The more than 10% tin content is what enables the new germanium-tin semiconductor optical properties, according to the scientists. The laser is currently limited to low temperatures of up to minus 183 degrees Celsius in the test system. The next big step will be generating laser light with electricity, and without the need for cooling, if possible. The aim is to create an electrically pumped laser that functions at room temperature.
*The basis of chip manufacturing is silicon, an element of main group IV of the periodic table. Typical semiconductor lasers for telecommunication systems, made of gallium arsenide for example, however, are costly and consist of elements from main groups III or V. This has profound consequences on the crystal properties. Such laser components cannot therefore be applied directly onto silicon. They have to be produced externally at great effort and subsequently glued to the silicon wafer. However, the lifetime of this kind of component is greatly reduced due to the fact that the thermal expansion coefficients of these elements are significantly different from that of silicon. In contrast, semiconductors of main group IV — to which both silicon and germanium belong — can be integrated into the manufacturing process without any major difficulties. Neither element by itself is very efficient as a light source, however. They are classed among the indirect semiconductors. In contrast to direct semiconductors, they emit mostly heat and only a little light when excited.
The scientists at Jülich’s Peter Grünberg Institute have now for the first time succeeded in creating a “real” direct main group IV semiconductor laser by combining germanium and tin, which is also classed in main group IV.
Manufacturers have begun experimenting with a new generation of “cobots” (collaborative robots) designed to work side-by-side with humans. To determine best practices for effectively integrating human-robot teams within manufacturing environments, a University of Wisconsin-Madison team headed by Bilge Mutlu, an assistant professor of computer sciences, is working with an MIT team headed by Julie A. Shah, an assistant professor of aeronautics and astronautics.
Their research is funded by a three-year grant from the National Science Foundation (NSF) as part of its National Robotics Initiative program.
Cobots are less expensive and intended to be easier to reprogram and integrate into manufacturing. For example, Steelcase owns four next-generation robots based on a platform called Baxter, made by Rethink Robotics.
Each Baxter robot has two arms and a tablet-like panel for “eyes” that provide cues to help human workers anticipate what the robot will do next.
“This new family of robotic technology will change how manufacturing is done,” says Mutlu. “New research can ease the transition of these robots into manufacturing by making human-robot collaboration better and more natural as they work together.”
Mutlu’s team is building on previous work related to topics such as gaze aversion in humanoid robots, robot gestures, and the issue of “speech and repair.” For example, if a human misunderstands a robot’s instructions or carries them out incorrectly, how should the robot correct the human?
A new Princeton University study has identified more than 750 genes involved in long-term memory in the worm — part of research aimed at finding ways to retain cognitive abilities during aging, including compounds.
The new study, published in the journal Neuron, included many genes that had not been found previously and that could serve as targets for future research, said senior author Coleen Murphy, an associate professor of molecular biology at Princeton and the Lewis-Sigler Institute for Integrative Genomics.
The researchers then scanned the genomes of both trained worms and non-trained worms, looking for genes turned on by CREB. The researchers detected 757 CREB-activated genes in the long-term memory-trained worms, and showed that these genes were turned on primarily in worm cells called the AIM interneurons. They also found CREB-activated genes in non-trained worms, but the genes were not turned on in AIM interneurons and were not involved in long-term memory. CREB turns on genes involved in other biological functions such as growth, immune response, and metabolism. Throughout the worm, the researchers noted distinct non-memory (or “basal”) genes in addition to the memory-related genes.
“There is a pretty direct relationship between CREB and long-term memory,” Murphy said, “and many organisms lose CREB as they age.” By studying the CREB-activated genes involved in long-term memory, the researchers hope to better understand why some organisms lose their long-term memories as they age.
Worms are a perfect system in which to explore that question, Murphy said. The worm Caenorhabditis elegans has only 302 neurons, whereas a typical mammalian brain contains billions of the cells. “Worms use the same molecular machinery that higher organisms, including mammals, use to carry out long-term memory,” said Murphy. “We hope that other researchers will take our list and look at the genes to see whether they are important in more complex organisms.”
The next step, said Murphy, is to find out what these newly recognized long-term memory genes do when they are activated by CREB. For example, the activated genes may strengthen connections between neurons.
In the largest collaborative study of the brain to date, about 300 researchers in a global consortium of 190 institutions identified eight common genetic mutations that appear to age the brain an average of three years. The discovery could lead to targeted therapies and interventions for Alzheimer’s disease, autism, and other neurological conditions.
Led by the Keck School of Medicine of the University of Southern California (USC), an international team known as the Enhancing Neuro Imaging Genetics through Meta Analysis (ENIGMA) Network, pooled brain scans and genetic data worldwide to pinpoint genes that enhance or break down key brain regions in people from 33 countries.
This is the first high-profile study since the National Institutes of Health (NIH) launched its Big Data to Knowledge (BD2K) centers of excellence in 2014. The research was published Wednesday, Jan. 21, in the peer-reviewed journal Nature.
“Our global team discovered eight genes that may erode or boost brain tissue in people worldwide,” said Paul Thompson, Ph.D., Keck School of Medicine of USC professor and principal investigator of ENIGMA. ” Any change in those genes appears to alter your mental bank account or brain reserve by 2 or 3 percent. The discovery will guide research into more personalized medical treatments for Alzheimer’s, autism, depression and other disorders.”
The study could help identify people who would most benefit from new drugs designed to save brain cells, but more research is necessary to determine if the genetic mutations are implicated in disease. The ENIGMA researchers screened millions of “spelling differences” in the genetic code to see which ones affected the size of key parts of the brain in magnetic resonance images (MRIs) from 30,717 individuals.
The MRI analysis focused on genetic data from seven regions of the brain that coordinate movement, learning, memory and motivation. The group identified eight genetic variants associated with decreased brain volume, several found in over one-fifth of the world’s population. People who carry one of those eight mutations had, on average, smaller brain regions than brains without a mutation but of comparable age; some of the genes are implicated in cancer and mental illness.
RANDAL KOENE IS RECRUITING TOP NEUROSCIENTISTS TO HELP HIM MAKE HUMANS LIVE FOREVER
While the first upload of a human brain remains decades—if not centuries— away, proponents believe humanity may be far closer to reaching another key technological milestone: a preservation technique that could store a brain indefinitely without damaging its neurons or the trillions of microscopic connections between them.
“If we could put the brain into a state in which it does not decay, then the second step could be done 100 years later,” says Kenneth Hayworth, a senior scientist at Howard Hughes Medical Institute, “and everyone could experience mind uploading first hand.”
To promote this goal, Hayworth cofounded The Brain Preservation Foundation, a nonprofit that is offering a $106,000 technology prize to the first scientist or team to rise to that challenge. He says the first stage of the competition—the preservation of an entire mouse brain—may be won within the year, an achievement that would excite many mainstream neuroscientists, who want to map the brain’s circuitry to better understand memory and behavior.
Current preservation methods (aside from cryonics, which has never successfully been demonstrated to preserve the brain’s wiring) involve pumping chemicals through the body that can fix proteins and lipids in place. The brain is then removed and immersed in a series of solutions that dehydrate naturally occurring water and replace it with a plastic resin. The resin prevents chemical reactions that cause decay, preserving the brain’s intricate architecture. But in order for all of the chemicals to fully permeate brain tissue, scientists must first slice the organ into sections 100 to 500 microns thick—a process that destroys information stored in connections made along those surfaces.
Shawn Mikula, a researcher at the Max Planck Institute for Medical Research in Heidelberg, Germany, developed a protocol that appears to safeguard all of the brain’s synapses. It preserves the extracellular space in the brain so that the chemicals can diffuse through myriad layers of the whole organ. Then, if the brain is sliced and analyzed at a future date, all of its circuitry will remain visible. Hayworth is currently using electron microscopy to examine the mouse brains sent to him as proof of principle. (In order to win the technology prize, the protocol must also be published in a peer-reviewed journal.) So far, Hayworth says, Mikula’s technique seems effective.
If immortality is defined as brain preservation via plastination, Mikula says, then it’s a reasonable extrapolation of his research results. But as for actually uploading it to a computer: “Who can predict these things? Science is modern-day magic,” Mikula says, “and in the absence of a strong argument against the future feasibility of mind uploading, anything is possible.”
University of California, Berkeley, scientists have proved a fundamental relationship between energy and time that sets a "quantum speed limit" on processes ranging from quantum computing and tunneling to optical switching.
The energy-time uncertainty relationship is the flip side of the Heisenberg uncertainty principle, which sets limits on how precisely you can measure position and speed, and has been the bedrock of quantum mechanics for nearly 100 years. It has become so well-known that it has infected literature and popular culture with the idea that the act of observing affects what we observe.
"This is the first time the energy-time uncertainty principle has been put on a rigorous basis - our arguments don't appeal to experiment, but come directly from the structure of quantum mechanics," said chemical physicist K. Birgitta Whaley, director of the Berkeley Quantum Information and Computation Center and a UC Berkeley professor of chemistry. "Before, the principle was just kind of thrown into the theory of quantum mechanics."
The new derivation of the energy-time uncertainty has application for any measurement involving time, she said, particularly in estimating the speed with which certain quantum processes - such as calculations in a quantum computer - will occur.
"The uncertainty principle really limits how precise your clocks can be," said first author Ty Volkoff, a graduate student who just received his Ph.D. in chemistry from UC Berkeley. "In a quantum computer, it limits how fast you can go from one state to the other, so it puts limits on the clock speed of your computer."