New Zealand News
Safety concerns for passengers and even drivers continue to be a major cause of concern for the ride sharing industry around the world.
Companies like Uber and Lyft have benefitted greatly with the exponential growth in the industry, which did not exist just a decade earlier. The companies argue that their technology, driver background checks, and two-way rating systems ensure the safety of the users of the apps. However, many express concerns over these factors and the insurance coverage.
Around 30 U. S. jurisdictions have passed new ride-hailing regulatory legislations aiming to make the ride sharing industry safer for everyone. Safety is the key cause of concern for the rise haring industry as well as its competitor, the taxi and limousine services around the world. More than eight in ten people said in a new survey that safety was the key factor when using either a taxi or a ride-hailing service like Uber or Lyft.
Industry experts say that safety issue are over emphasised for the industry. They argue that there is no evidence to state that ride hailing services are more dangerous than traditional taxis.Business: BusinessAuto SectorCompanies: UberLyftRegion: United States
Tim Cook, the Chief Executive Officer of Apple, is on a visit to China in order to boost company's business in the large Asian market and also form new relationships with partners, developers and others.
Cook posted a picture of himself and DidiChuxing's President Jean Lui catching a cab. The picture showcases a new partnership for Apple with China's largest ride-hailing firm after Apple announced that it will invest $1 billion in the Chinese company. Some say that the partnership will not be limited to Apple providing software and services but may exceed to the future for jointly developing self-driving cars and other projects.
Experts say that China has not been an easy market for Apple as it faces a number of regulatory challenges and its revenue from the country has fallen 11 per cent. However, Apple cannot afford to ignore the important Chinese market, which is the second largest market for the company in the world. Many believe that the visit by the new head will allow Apple to fix its relationship with the government and customers and create new partnerships to attract developers to the platform.Companies: AppleRegion: ChinaBusiness: Technology SectorPeople: Tim Cook
The International Anti Counterfeiting Coalition, which is a leading anti-counterfeit group, has suspended the membership of Alibaba Group Holding Ltd.
The Chinese online trading giant was suspected just a month after it was allowed to join the group over concerns about conflicts of interest involving the coalition's president and complaints from some of the members of the group.
The nonprofit global organization, which is is aimed at fighting counterfeit products and piracy, had created a new membership category in April allowing the Chinese internet giant to join the group. The Chinese firm is aiming to change its image of being a portal for cheap brand knockoffs. However, some members were critical of the company joining the group and they said that the company is not taking adequate steps to stop counterfeit products from its online marketplace.
The group admitted that the conflicts of interest involving President Bob Barchiesi were not reported to the directors because of "weakness in our corporate governance procedures." A letter from the IACC board said that it is putting the new membership classification on hold to allow more discussion and consideration.
Under the new category, two others including Wish.com and The RealReal were also suspended by the group.Business: BusinessCompanies: AlibabaRegion: China
Berkshire Hathaway chairman and billionaire investor Warren Buffett might be planning to back consortium bidding for Yahoo's Internet assets.
The consortium also includes Dan Gilbert, Quicken Loans' founder and owner of the NBA's Cleveland Cavaliers, according to people closer to the matter. The entry of Buffett in the bidding process was reported earlier but representative for Yahoo, representatives for Berkshire Hathaway and Gilbert 's Rock did not offer any comment on the matter.
The consortium is among the several others looking to acquire the internet assets of the company, which is struggling to compete in the market. Some reports suggested that American telecom giant,Verizon is believed to be the front-runner in the auction process, which is already in its second stage.
Yahoo, which was once a leader on the internet, is currently headed by CEO Marissa Mayer. The company is struggling to manage its finances and there is significant struggle against the turnaround plan of Mayer, which led to the auction due to increased pressure from shareholders. Even as the company connects almost a 1 billion online, it is facing stiff competition from the likes of Google, Facebook and others for digital advertising.
After the reports of Buffett joining the bidding, the shares of Yahoorecorded an increase of 1.4 per cent to $37 per share in after-hours trading.Berkshire Hathaway's B class shares recorded a fall of 1 per cent to $141.50.Business: Telecom SectorCompanies: YahooPeople: Warren Buffett
Holograms are a ubiquitous part of our lives. They are in our wallets — protecting credit cards, cash and driver’s licenses from fraud — in grocery store scanners and biomedical devices.
Even though holographic technology has been around for decades, researchers still struggle to make compact holograms more efficient, complex and secure.
Researchers at the Harvard John A. Paulson School of Engineering and Applied Sciences have programmed polarization into compact holograms. These holograms use nanostructures that are sensitive to polarization (the direction in which light vibrates) to produce different images depending on the polarization of incident light. This advancement, which works across the spectrum of light, improves anti-fraud holograms as well as those used in entertainment displays.
The research is described in Sciences Advances.
“The novelty in this research is that by using nanotechnology, we’ve made holograms that are highly efficient, meaning that very little light is lost to create the image,” said Federico Capasso, the Robert L. Wallace Professor of Applied Physics and Vinton Hayes Senior Research Fellow in Electrical Engineering and senior author of the paper. “By using incident polarized light, you can see far a crisper image and can store and retrieve more images. Polarization adds another dimension to holograms that can be used to protect against counterfeiting and in applications like displays.”
Harvard’s Office of Technology Development has filed patents on this and related technologies and is actively pursuing commercial opportunities.
Holograms, like digital photographs, capture a field of light around an object and encode it on a chip. However, photographs only record the intensity of light while holograms also capture the phase of light, which is why holograms appear three-dimensional.
“Our holograms work like any other but the image produced depends on the polarization state of the illuminating light, providing an extra degree of freedom in design for versatile applications,” said Mohammadreza Khorasaninejad, postdoctoral fellow in the Capasso Lab and first author of the paper.
There are several states of polarization. In linearly polarized light the direction of vibration remains constant while in circularly polarized light it rotates clockwise or counterclockwise. The direction of rotation is the chirality.
The team built silicon nanostructured patterns on a glass substrate, which act as superpixels. Each superpixel responds to a certain polarization state of the incident light. Even more information can be encoded in the hologram by designing and arranging the nanofins to respond differently to the chirality of the polarized incident light.
“Being able to encode chirality can have important applications in information security such as anti-counterfeiting,” said Antonio Ambrosio, a research scientist in the Capasso Lab and co-first author. “For example, chiral holograms can be made to display a sequence of certain images only when illuminated with light of specific polarization not known to the forger.”
“By using different nanofin designs in the future, one could store and retrieve far more images by employing light with many states of polarization,” said Capasso.
Because this system is compact, it has application in portable projectors, 3D movies and wearable optics.
“Modern polarization imaging systems require cascading several optical components such as beam splitters, polarizers and wave plates,” said Ambrosio. “Our metasurface can distinguish between incident polarization using a single layer dielectric surface.”
“We have also incorporated in some of the holograms a lens function that has allowed us to produce images at large angles,” said Khorasaninejad. “This functionality combined with the small footprint and lightweight, has significant potential for wearable optics applications.”
This work was supported in part by the Air Force Office of Scientific Research Google Inc. and Thorlabs Inc.General: ScienceResearch
Flick a switch on a dark winter day and your office is flooded with bright light, one of many everyday miracles to which we are all usually oblivious.
A physicist would probably describe what is happening in terms of the particle nature of light. An atom or molecule in the fluorescent tube that is in an excited state spontaneously decays to a lower energy state, releasing a particle called a photon. When the photon enters your eye, something similar happens but in reverse. The photon is absorbed by a molecule in the retina and its energy kicks that molecule into an excited state.
Light is both a particle and a wave, and this duality is fundamental to the physics that rule the Lilliputian world of atoms and molecules. Yet it would seem that in this case the wave nature of light can be safely ignored.
Kater Murch, assistant professor of physics in Arts & Sciences at Washington University in St. Louis, might give you an argument about that. His lab is one of the first in the world to look at spontaneous emission with an instrument sensitive to the wave rather than the particle nature of light, work described in the May 20th issue of Nature Communications.
His experimental instrument consists of an artificial atom (actually a superconducting circuit with two states, or energy levels) and an interferometer, in which the electromagnetic wave of the emitted light interferes with a reference wave of the same frequency.
This manner of detection turns everything upside down, he said. All that a photon detector can tell you about spontaneous emission is whether an atom is in its excited state or its ground state. But the interferometer catches the atom diffusing through a quantum "state space" made up of all the possible combinations, or superpositions, of its two energy states.
This is actually trickier than it sounds because the scientists are tracking a very faint signal (the electromagnetic field associated with one photon), and most of what they see in the interference pattern is quantum noise. But the noise carries complementary information about the state of the artificial atom that allows them to chart its evolution.
When viewed in this way, the artificial atom can move from a lower energy state to a higher energy one even as its follows the inevitable downward trajectory to the ground state. "You'd never see that if you were detecting photons," Murch said.
So different detectors see spontaneous emission very differently. "By looking at the wave nature of light, we are able see this lovely diffusive evolution between the states," Murch said.
But it gets stranger. The fact that an atom's average excitation can increase even when it decays is a sign that how we look at light might give us some control over the atoms that emitted the light, Murch said.
This might sound like a reversal of cause and effect, with the effect pushing on the cause. It is possible only because of one of the weirdest of all the quantum effects: When an atom emits light, quantum physics requires the light and the atom to become connected, or entangled, so that measuring a property of one instantly reveals the value of that property for the other, no matter how far away it is.
Or put another way, every measurement of an entangled object perturbs its entangled partner. It is this quantum back-action, Murch said, that could potentially allow a light detector to control the light emitter.
"Quantum control has been a dream for many years," Murch said. "One day, we may use it to enhance fluorescence imaging by detecting the light in a way that creates superpositions in the emitters.
"That's very long term, but that's the idea," he said.Region: United StatesGeneral: Science
A faint blue galaxy about 30 million light-years from Earth and located in the constellation Leo Minor could shed new light on conditions at the birth of the universe.
Astronomers at Indiana University recently found that a galaxy nicknamed Leoncino, or "little lion," contains the lowest level of heavy chemical elements, or "metals," ever observed in a gravitationally bound system of stars.
The study appears today in the Astrophysical Journal. The lead author on the paper is Alec S. Hirschauer, a graduate student in the IU Bloomington College of Arts and Sciences' Department of Astronomy. Other IU authors on the paper are professor John J. Salzer and associate professor Katherine L. Rhode in the Department of Astronomy.
"Finding the most metal-poor galaxy ever is exciting since it could help contribute to a quantitative test of the Big Bang," Salzer said. "There are relatively few ways to explore conditions at the birth of the universe, but low-metal galaxies are among the most promising."
This is because the current accepted model of the start of the universe makes clear predictions about the amount of helium and hydrogen present during the Big Bang, and the ratio of these atoms in metal-poor galaxies provides a direct test of the model.
In astronomy, any element other than hydrogen or helium is referred to as a metal. The elemental make-up of metal-poor galaxies is very close to that of the early universe.
To find these low-metal galaxies, however, astronomers must look far from home. Our own Milky Way galaxy is a poor source of data due to the high level of heavier elements created over time by "stellar processing," in which stars churn out heavier elements through nucleosynthesis and then distribute these atoms back into the galaxy when they explode as supernovae.
"Low metal abundance is essentially a sign that very little stellar activity has taken place compared to most galaxies," Hirschauer said.
Leoncino is considered a member of the "local universe," a region of space within about 1 billion light years from Earth and estimated to contain several million galaxies, of which only a small portion have been cataloged. A galaxy previously recognized to possess the lowest metal abundance was identified in 2005; however, Leoncino has an estimated 29 percent lower metal abundance.
The abundance of elements in a galaxy is estimated based upon spectroscopic observations, which capture the light waves emitted by these systems. These observations allow astronomers to view the light emitted by galaxies like a rainbow created when a prism disperses sunlight.
Regions of space that form stars, for example, emit light that contains specific types of bright lines, each indicating the atoms from various gases: hydrogen, helium, oxygen, nitrogen and more. In the light of the star-forming region in Leoncino, IU scientists detected lines from these elements, after which they used the laws of atomic physics to calculate the abundance of specific elements.
"A picture is worth a thousand words, but a spectrum is worth a thousand pictures," Salzer said. "It's astonishing the amount of information we can gather about places millions of light years away."
The study's observations were made by spectrographs on two telescopes in Arizona: the Mayall 4-meter telescope at the Kitt Peak National Observatory and the Multiple Mirror Telescope at the summit of Mount Hopkins near Tucson. The galaxy was originally discovered by Cornell University's Arecibo Legacy Fast ALFA, or ALFALFA, radio survey project.
Officially, the "little lion" is named AGC 198691. The scientists who conducted the metal abundance analysis nicknamed the galaxy Leoncino in honor of both its constellation location and in recognition of the Italian-born radio astronomer, Riccardo Giovanelli, who led the group that first identified the galaxy.
Aside from low levels of heavier elements, Leoncino is unique in several other ways. A so-called "dwarf galaxy," it's only about 1,000 light years in diameter and composed of several million stars. The Milky Way, by comparison, contains an estimated 200 billion to 400 billion stars. Leoncino is also blue in color, due to the presence of recently formed hot stars, but surprisingly dim, with the lowest luminosity level ever observed in a system of its type.
"We're eager to continue to explore this mysterious galaxy," said Salzer, who is pursuing observing time on other telescopes, including the Hubble Space Telescope, to delve deeper into this fascinating object. "Low-metal-abundance galaxies are extremely rare, so we want to learn everything we can."Region: IndianaGeneral: ScienceSpace
The discovery that dung beetles use the light of the Milky Way to navigate in the world has received much praise. Researchers at Lund University in Sweden have now taken a new step in understanding the existence of these unique beetles: when the beetles dance on top of a ball of dung, they simultaneously take a photograph -- a snapshot -- of how celestial bodies are positioned.
Then they know where they are going and roll off with their ball of dung in a straight line across the savannah.
"Other animals and insects also use the position of celestial bodies to navigate, but the dung beetles are unique -- they are the only ones to take a snapshot where they gather information about how various celestial bodies, such as the sun, moon and stars, are positioned," says Basil el Jundi, researcher at Lund University.
He conducted the study together with colleagues Marie Dacke, Emily Baird, James J. Foster and Lana Khaldy, who all work at the world-leading Lund Vision Group at Lund University. Researchers from South Africa also participated in the study.
By applying the snapshot strategy to orient themselves in the world, the dung beetles use their potential to the fullest, according to Basil el Jundi. They do not use long processes to retrieve information -- a single snapshot is sufficient to navigate correctly.
"We are the first to have shown that dung beetles are taking these snapshots. We are also the first to show how they store and use the images inside their tiny brains," he says.
The snapshot is taken when the beetle is dancing, and the image is stored in the brain. When the beetle then starts to roll its ball of dung, it is able to successfully navigate straight ahead by matching the stored snapshot of the sky with the present environment.
The experiments were performed in South Africa at a facility where the dung beetles only had access to an artificial firmament to orient themselves. Because the sky was artificial, the researchers were able to regulate the amount of light, as well as change the positions of the celestial bodies. Put simply, this allowed them to compare how the beetles changed direction depending on the placement of the artificial sun or moon, etc.
Taking snapshots of the firmament is unique to dung beetles. Ants also take snapshots, but of their surroundings on Earth rather than the sky. However, dung beetles are not the only ones that dance, spinning around before taking off. Ants rotate and bees and wasps take a tour of their nest. No one knows why.
"Perhaps they also gather information while rotating or going for a spin in the air, but we don't know," says Basil el Jundi.
According to him, the results of how dung beetles find their way in the world can become significant in the development of navigation systems in driverless vehicles.Region: SwedenGeneral: ScienceResearch
For decades, scientists have fiercely debated whether rapid eye movement (REM) sleep -- the phase where dreams appear -- is directly involved in memory formation.
Now, a study published in Science by researchers at the Douglas Mental Health University Institute (McGill University) and the University of Bern provides evidence that REM sleep does, indeed, play this role -- at least in mice.
"We already knew that newly acquired information is stored into different types of memories, spatial or emotional, before being consolidated or integrated," says Sylvain Williams, a researcher and professor of psychiatry at McGill.
"How the brain performs this process has remained unclear -- until now. We were able to prove for the first time that REM sleep is indeed critical for normal spatial memory formation in mice," explains Williams, whose team is also part of the CIUSSS de l'Ouest-de-l'Île-de-Montréal research network. Williams co-authored the study with Antoine Adamantidis, a researcher at the University of Bern's Department of Clinical Research and at the Sleep Wake Epilepsy Center of the Bern University Hospital.
A dream quest
Hundreds of previous studies have tried unsuccessfully to isolate neural activity during REM sleep using traditional experimental methods. In this new study, the researchers used optogenetics, a recently developed technology that enables scientists to target precisely a population of neurons and control its activity by light.
"We chose to target neurons that regulate the activity of the hippocampus, a structure that is critical for memory formation during wakefulness and is known as the 'GPS system' of the brain," Williams says.
To test the long-term spatial memory of mice, the scientists trained the rodents to spot a new object placed in a controlled environment where two objects of similar shape and volume stand. Spontaneously, mice spend more time exploring a novel object than a familiar one, showing their use of learning and recall. When these mice were in REM sleep, however, the researchers used light pulses to turn off their memory-associated neurons to determine if it affects their memory consolidation. The next day, the same rodents did not succeed the spatial memory task learned on the previous day. Compared to the control group, their memory seemed erased, or at least impaired.
"Silencing the same neurons for similar durations outside REM episodes had no effect on memory. This indicates that neuronal activity specifically during REM sleep is required for normal memory consolidation," says the study's lead author Richard Boyce, a PhD student who, ironically, often stayed up all night while performing the experiments.
Implications for brain disease
REM sleep is understood to be a critical component of sleep in all mammals, including humans. Poor sleep-quality is increasingly associated with the onset of various brain disorders such as Alzheimer's and Parkinson's disease.
In particular, REM sleep is often significantly perturbed in Alzheimer's diseases (AD), and results from this study suggest that disruption of REM sleep may contribute directly to memory impairments observed in AD, the researchers say.Region: CanadaGeneral: HealthResearch
New work from a team including Carnegie's Hanika Rizo and Richard Carlson, as well as Richard Walker from the University of Maryland, has found material in rock formations that dates back to shortly after Earth formed. The discovery will help scientists understand the processes that shaped our planet's formative period and its internal dynamics over the last 4.5 billion years. It is published by Science.
Earth formed from the accretion of matter surrounding the young Sun. The heat of its formation caused extensive melting of the planet, leading Earth to separate into two layers when the denser iron metal sank inward toward the center, creating the core and leaving the silicate-rich mantle floating above.
Over the subsequent 4.5 billion years of Earth's evolution, convection in Earth's interior, like water boiling on a stove, caused deep portions of the mantle to rise upwards, melt, and then separate once again by density. The melts, since they were less dense than the unmelted rock, rose to form Earth's crust, while the denser residues of the melting sank back downward, altering the mantle's chemical composition in the process.
The mantle residues of crust formation were previously believed to have mixed back into the mantle so thoroughly that evidence of the planet's oldest geochemical events, such as core formation, was lost completely.
However, the research team--which also included Sujoy Mukhopadhyay and Vicky Manthos of University of California Davis, Don Francis of McGill University, and Matthew Jackson, a Carnegie alumnus now at University of California Santa Barbara--was able find a geochemical signature of material left over from the early melting events that accompanied Earth's formation. They found it in relatively young rocks both from Baffin Island, off the coast of northern Canada, and from the Ontong-Java Plateau in the Pacific Ocean, north of the Solomon Islands.
These rock formations are called flood basalts because they were created by massive eruptions of lava. The solidified lava itself is only between 60 and 120 million years old, depending on its location. But the team discovered that the molten material from inside Earth that long ago erupted to create these plains of basaltic rock owes its chemical composition to events that occurred over 4.5 billion years in the past.
Here's how they figured it out:
They measured variations in these rocks of the abundance of an isotope of tungsten--the same element used to make filaments of incandescent light bulbs. Isotopes are versions of an element in which the number of neutrons in each atom differs from the number of protons. (Each element contains a unique number of protons.) These differing neutron numbers mean that each isotope has a slightly different mass.
Why tungsten? Tungsten contains one isotope of mass 182 that is created when an isotope of the element hafnium undergoes radioactive decay, meaning its elemental composition changes as it gives off radiation. The time it takes for half of any quantity of hafnium-182 to decay into tungsten-182 is 9 million years. This may sound like a very long time, but is quite rapid when it comes to planetary formation timescales. Rocky planets like Earth or Mars took about 100 million years to form.
The team determined that the basalts from Baffin Island, formed by a 60-million-year-old eruption from the mantle hot-spot currently located beneath Iceland, and the Ontong-Java Plateau, which was formed by an enormous volcanic event about 120 million years ago, contain slightly more tungsten-182 than other young volcanic rocks.
Because all the hafnium-182 decayed to tungsten-182 during the first 50 million years of Solar System history, these findings indicate that the mantle material that melted to form the flood basalt rocks that the team studied originally had more hafnium than the rest of the mantle. The likely explanation for this is that the portion of Earth's mantle from which the lava came had experienced a different history of iron separation than other portions of the mantle (since tungsten is normally removed to the core along with the iron.)
It was a surprise to the team that such material still exists in Earth's interior.
"This demonstrates that some remnants of the early Earth's interior, the composition of which was determined by the planet's formation processes, still exist today," explained lead author Rizo, now at Université du Québec à Montréal.
"The survival of this material would not be expected given the degree to which plate tectonics has mixed and homogenized the planet's interior over the past 4.5 billion years, so these findings are a wonderful surprise," added Carlson, Director of Carnegie's Department of Terrestrial Magnetism.
The team's discovery offers new insight into the chemistry and dynamics that shaped our planet's formative processes. Going forward, scientists will have to hunt for other areas showing outsized amounts of tungsten-182 with the hope of illuminating both the earliest portion of Earth's history as well as the place in Earth's interior where this ancient material is stored.Region: New YorkGeneral: ScienceResearch
Most people do not give much thought to the Earth's magnetic field, yet it is every bit as essential to life as air, water and sunlight. The magnetic field provides an invisible, but crucial, barrier that protects Earth from the sun's magnetic field, which drives a stream of charged particles known as the solar wind outward from the sun's outer layers. The interaction between these two magnetic fields can cause explosive storms in the space near Earth, which can knock out satellites and cause problems here on Earth's surface, despite the protection offered by Earth's magnetic field.
A new study co-authored by University of Maryland physicists provides the first major results of NASA's Magnetospheric Multiscale (MMS) mission, including an unprecedented look at the interaction between the magnetic fields of Earth and the sun. The paper describes the first direct and detailed observation of a phenomenon known as magnetic reconnection, which occurs when two opposing magnetic field lines break and reconnect with each other, releasing massive amounts of energy.
The discovery is a major milestone in understanding magnetism and space weather. The research paper appears in the May 13, 2016, issue of the journal Science.
"Imagine two trains traveling toward each other on separate tracks, but the trains are switched to the same track at the last minute," said James Drake, a professor of physics at UMD and a co-author on the Science study. "Each track represents a magnetic field line from one of the two interacting magnetic fields, while the track switch represents a reconnection event. The resulting crash sends energy out from the reconnection point like a slingshot."
Evidence suggests that reconnection is a major driving force behind events such as solar flares, coronal mass ejections, magnetic storms, and the auroras observed at both the North and South poles of Earth. Although researchers have tried to study reconnection in the lab and in space for nearly half a century, the MMS mission is the first to directly observe how reconnection happens.
The MMS mission provided more precise observations than ever before. Flying in a pyramid formation at the edge of Earth's magnetic field with as little as 10 kilometers' distance between four identical spacecraft, MMS images electrons within the pyramid once every 30 milliseconds. In contrast, MMS' predecessor, the European Space Agency and NASA's Cluster II mission, takes measurements once every three seconds--enough time for MMS to make 100 measurements.
"Just looking at the data from MMS is extraordinary. The level of detail allows us to see things that were previously a blur," explained Drake, who served on the MMS science team and also advised the engineering team on the requirements for MMS instrumentation. "With a time interval of three seconds, seeing reconnection with Cluster II was impossible. But the quality of the MMS data is absolutely inspiring. It's not clear that there will ever be another mission quite like this one."
Simply observing reconnection in detail is an important milestone. But a major goal of the MMS mission is to determine how magnetic field lines briefly break, enabling reconnection and energy release to happen. Measuring the behavior of electrons in a reconnection event will enable a more accurate description of how reconnection works; in particular, whether it occurs in a neat and orderly process, or in a turbulent, stormlike swirl of energy and particles.
A clearer picture of the physics of reconnection will also bring us one step closer to understanding space weather--including whether solar flares and magnetic storms follow any sort of predictable pattern like weather here on Earth. Reconnection can also help scientists understand other, more energetic astrophysical phenomena such as magnetars, which are neutron stars with an unusually strong magnetic field.
"Understanding reconnection is relevant to a whole range of scientific questions in solar physics and astrophysics," said Marc Swisdak, an associate research scientist in UMD's Institute for Research in Electronics and Applied Physics. Swisdak is not a co-author on the Science paper, but he is actively collaborating with Drake and others on subsequent analyses of the MMS data.
"Reconnection in Earth's magnetic field is relatively low energy, but we can get a good sense of what is happening if we extrapolate to more energetic systems," Swisdak added. "The edge of Earth's magnetic field is an excellent test lab, as it's just about the only place where we can fly a spacecraft directly through a region where reconnection occurs."
To date, MMS has focused only on the sun-facing side of Earth's magnetic field. In the future, the mission is slated to fly to the opposite side to investigate the teardrop-shaped tail of the magnetic field that faces away from the sun.General: ScienceSpaceCompanies: NASARegion: Maryland
In experiments involving a simulation of the human esophagus and stomach, researchers at MIT, the University of Sheffield, and the Tokyo Institute of Technology have demonstrated a tiny origami robot that can unfold itself from a swallowed capsule and, steered by external magnetic fields, crawl across the stomach wall to remove a swallowed button battery or patch a wound.
The new work, which the researchers are presenting this week at the International Conference on Robotics and Automation, builds on a long sequence of papers on origami robots from the research group of Daniela Rus, the Andrew and Erna Viterbi Professor in MIT's Department of Electrical Engineering and Computer Science.
"It's really exciting to see our small origami robots doing something with potential important applications to health care," says Rus, who also directs MIT's Computer Science and Artificial Intelligence Laboratory (CSAIL). "For applications inside the body, we need a small, controllable, untethered robot system. It's really difficult to control and place a robot inside the body if the robot is attached to a tether."
Joining Rus on the paper are first author Shuhei Miyashita, who was a postdoc at CSAIL when the work was done and is now a lecturer in electronics at the University of York, in England; Steven Guitron, a graduate student in mechanical engineering; Shuguang Li, a CSAIL postdoc; Kazuhiro Yoshida of Tokyo Institute of Technology, who was visiting MIT on sabbatical when the work was done; and Dana Damian of the University of Sheffield, in England.
Although the new robot is a successor to one reported at the same conference last year, the design of its body is significantly different. Like its predecessor, it can propel itself using what's called a "stick-slip" motion, in which its appendages stick to a surface through friction when it executes a move, but slip free again when its body flexes to change its weight distribution.
Also like its predecessor -- and like several other origami robots from the Rus group -- the new robot consists of two layers of structural material sandwiching a material that shrinks when heated. A pattern of slits in the outer layers determines how the robot will fold when the middle layer contracts.
The robot's envisioned use also dictated a host of structural modifications. "Stick-slip only works when, one, the robot is small enough and, two, the robot is stiff enough," says Guitron. "With the original Mylar design, it was much stiffer than the new design, which is based on a biocompatible material."
To compensate for the biocompatible material's relative malleability, the researchers had to come up with a design that required fewer slits. At the same time, the robot's folds increase its stiffness along certain axes.
But because the stomach is filled with fluids, the robot doesn't rely entirely on stick-slip motion. "In our calculation, 20 percent of forward motion is by propelling water -- thrust -- and 80 percent is by stick-slip motion," says Miyashita. "In this regard, we actively introduced and applied the concept and characteristics of the fin to the body design, which you can see in the relatively flat design."
It also had to be possible to compress the robot enough that it could fit inside a capsule for swallowing; similarly, when the capsule dissolved, the forces acting on the robot had to be strong enough to cause it to fully unfold. Through a design process that Guitron describes as "mostly trial and error," the researchers arrived at a rectangular robot with accordion folds perpendicular to its long axis and pinched corners that act as points of traction.
In the center of one of the forward accordion folds is a permanent magnet that responds to changing magnetic fields outside the body, which control the robot's motion. The forces applied to the robot are principally rotational. A quick rotation will make it spin in place, but a slower rotation will cause it to pivot around one of its fixed feet. In the researchers' experiments, the robot uses the same magnet to pick up the button battery.
The researchers tested about a dozen different possibilities for the structural material before settling on the type of dried pig intestine used in sausage casings. "We spent a lot of time at Asian markets and the Chinatown market looking for materials," Li says. The shrinking layer is a biodegradable shrink wrap called Biolefin.
To design their synthetic stomach, the researchers bought a pig stomach and tested its mechanical properties. Their model is an open cross-section of the stomach and esophagus, molded from a silicone rubber with the same mechanical profile. A mixture of water and lemon juice simulates the acidic fluids in the stomach.
Every year, 3,500 swallowed button batteries are reported in the U.S. alone. Frequently, the batteries are digested normally, but if they come into prolonged contact with the tissue of the esophagus or stomach, they can cause an electric current that produces hydroxide, which burns the tissue. Miyashita employed a clever strategy to convince Rus that the removal of swallowed button batteries and the treatment of consequent wounds was a compelling application of their origami robot.
"Shuhei bought a piece of ham, and he put the battery on the ham," Rus says. "Within half an hour, the battery was fully submerged in the ham. So that made me realize that, yes, this is important. If you have a battery in your body, you really want it out as soon as possible."Region: EnglandGeneral: ScienceResearch
The discovery of stone tools alongside mastodon bones in a Florida river shows that humans settled the southeastern United States as much as 1,500 years earlier than scientists previously believed, according to a research team led by a Florida State University professor.
This site on the Aucilla River -- about 45 minutes from Tallahassee -- is now the oldest known site of human life in the southeastern United States. It dates back 14,550 years.
"This is a big deal," said Florida State University Assistant Professor of Anthropology Jessi Halligan. "There were people here. So how did they live? This has opened up a whole new line of inquiry for us as scientists as we try to understand the settlement of the Americas."
There is a cluster of sites all over North America that date to around 13,200 years old, but there are only about five in all of North and South America that are older.
Halligan's research was published today (May 13) in the academic journal Science Advances.
Halligan and her colleagues, including Michael Waters from Texas A&M University and Daniel Fisher from University of Michigan, excavated what's called the Page-Ladson site, which is located about 30 feet underwater in a sinkhole in the Aucilla River. The site was named after Buddy Page, a diver who first brought the site to the attention of archaeologists in the 1980s, and the Ladson family, which owns the property.
In the 1980s and 1990s, researchers James Dunbar and David Webb investigated the site and retrieved several stone tools and a mastodon tusk with cut marks from a tool in a layer more than 14,000 years old. However, the findings received little attention because they were considered too old to be real and questionable because they were found underwater.
Waters and Halligan, who is a diver, had maintained an interest in the site and believed that it was worth another look. Between 2012 and 2014, divers, including Dunbar, excavated stone tools and bones of extinct animals.
They found a biface -- a knife with sharp edges on both sides that is used for cutting and butchering animals -- as well as other tools. Fisher, a vertebrate paleontologist, also took another look at the mastodon tusk that Dunbar had retrieved during the earlier excavations and found it displayed obvious signs of cutting created to remove the tusk from the skull.
The tusk may have been removed to gain access to edible tissue at its base, Fisher said.
"Each tusk this size would have had more than 15 pounds of tender, nutritious tissue in its pulp cavity, and that would certainly have been of value," he said.
Another possible reason to extract a tusk is that ancient humans who lived in this same area are known to have used ivory to make weapons, he added.
Using the latest radiocarbon dating techniques, researchers found all artifacts dated about 14,550 years ago. Prior to this discovery, scientists believed a group of people called Clovis -- considered among the first inhabitants of the Americas -- settled the area about 13,200 years ago.
"The new discoveries at Page-Ladson show that people were living in the Gulf Coast area much earlier than believed," said Waters, director of Texas A&M's Center for the Study of the First Americans.
Added Halligan: "It's pretty exciting. We thought we knew the answers to how and when we got here, but now the story is changing."
Other researchers on the study are Angelina Perrotti and David Carlson from Texas A&M, Ivy Owens from the University of Cambridge, Joshua Feinberg and Mark Bourne from the University of Minnesota, Brendan Fenerty from the University of Arizona, Barbara Winsborough with the Texas State Museum, and Thomas Stafford Jr. from Stafford Research Laboratories in Colorado.
The research was funded by the Elfrieda Frank Foundation, the National Geographic Society and the North Star Archaeological Research Program and Chair in First American Studies of Texas A&M. It was also supported by the Ladson family, which allowed researchers to perform multiple excavations on their property over the past several years.Region: FloridaGeneral: ScienceResearch
A fruit called the noni -- now hyped for a vast array of unproven health benefits -- is distinctly unhealthy for the fruit fly, which has fascinated geneticists for a century. For the species of Drosophila that lives in labs around the world, noni signifies extermination with extreme prejudice: A fly will die if it eats yeast growing on noni.
And yet when collectors swung nets and baited traps with rotting banana on a small island between Madagascar and Africa, they found a close relative,Drosophila yakuba, that merrily gobbles yeast growing on these forbidden fruits.
Yeast growing on noni are the centerpiece on the islander fly's menu. But on the mainland, "D. yakuba is happy with whatever rotting fruit it can find, as long as it's not toxic," says John Pool, an assistant professor of genetics at the University of Wisconsin-Madison. "They scrape off the yeast cells that grow on rotting fruit and eat them, and their larvae swim through the rotting fruit." Pool is senior author of a study on the discovery that appears in the April 4, 2016 Proceedings of the National Academy of Sciences.
Pool says the toxin-surviving fruit flies on Mayotte are likely to become an important research subject for studying the evolution of dietary changes, "where we can borrow the genetic tools of the common laboratory fruit fly."
The fruit fly is a workhorse of genetics, but "most fruit fly labs focus on experiments with a small set of lab strains," Pool says. "Our interest is using fruit flies to learn about evolution in the field." Because a different fruit fly had also evolved immunity to noni, "Yakuba gives us a chance to ask, how predictable are these transitions? Will they use the same genes, or do these organisms have a wider palette so they can make a completely different choice next time?"
A collection effort on the island of Mayotte, led by Jean David of the French National Center for Scientific Research, identified the unusual Drosophila yakuba population and its bizarre preference for noni.
Island species have played a key role in evolutionary biology since Charles Darwin explored the Galapagos. "Arriving organisms find that life is different, food is different, they have to interact with different species," Pool says. "They interbreed less, if at all, with their mainland cousins, and for all these reasons, they are more free to go in different evolutionary directions."
Female yakuba flies on Mayotte prefer not to mate with mainland males, Pool says, helping establish the reproductive isolation that supports evolution of a new species.
"There were probably not that many options when these flies reached Mayotte," says Pool, "so they were stuck trying to survive on this toxic fruit."
Genetic analysis indicated that the island flies developed their immunity to noni toxin after reaching Mayotte about 30,000 years ago -- long after a similar transformation among Drosophila sechellia, another fruit fly in the region that also eats yeast from rotting noni.
And that raised the most intriguing question of all: How closely did the two genetic transformations parallel each other?
In Pool's lab, postdoctoral fellow Amir Yassin broke that question into one about the flies' attraction to noni, and a second about its immunity to noni toxin. "We did not see a strong signal of genetic parallelism in the evolution of attraction, but we did for the tolerance genes that render the toxin harmless," Pool says. "So not only had the same trait evolved in two species, but at least some of the same genes were involved."
Finding a fly that had recently changed its dining habits was intriguing for a very practical reason, says Pool, observing that most agricultural insect pests undergo a change of menu before they start to attack crops.General: HealthResearch
Netflix CEO Reed Hastings presented his point against the executive order passed by President Trump to ban entry of people from seven Muslim-dominated countries. While Trump’s order has been challenged the court and has been stayed, CEOs of many technology companies have come forward to criticize the order. Talking about the immigration order, Hastings said, “Trump’s actions are hurting Netflix employees around the world, and are so un-American it pains us all.”
In his Facebook post, Hasting said, “Trump's actions are hurting Netflix employees around the world, and are so un-American it pains us all. Worse, these actions will make America less safe (through hatred and loss of allies) rather than more safe. A very sad week, and more to come with the lives of over 600,000 Dreamers here in a America under imminent threat. It is time to link arms together to protect American values of freedom and opportunity.”
Google CEO Sundar Pichai has also talked about the order passed by the U.S. President. Facebook, Microsoft and Uber also released statement condemning the order. The order has put a temporary ban on people coming from seven countries for 90 days to travel to the United States. The U.S. administration will figure out the best way to screen immigrants and President Trump said that there will be extreme vetting before people are allowed in the United States.
Thousands of protestors reached airports and many were also protesting on the street against executive orders passed by President Trump.Politics: General PoliticsRegion: United StatesBusiness: Technology SectorPeople: Donald Trump
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