The small radio-frequency signals given off by the recovering nuclei provide the imaging data.
Klaas Pruessmann at the University of Zurich, Switzerland, his student David Brunner and their colleagues removed the radio-frequency coil used to tumble the nuclei from an MRI machine built by Philips Healthcare
they magnetize more nuclei, giving stronger signals. But stronger fields need higher frequency, shorter wavelength radio-frequency signals,
but sulphate and soot particles from fossil fuel burning are the main culprits, the team found."
aerosol particles can act as seeds for clouds, which help to reflect the Sun's rays back into space
Nuclear magnetic resonance (NMR) and its close cousin magnetic resonance imaging (MRI) give information about a sample s structure by detecting the weak magnetic forces in certain atomic nuclei, such as hydrogen.
which way the nitrogen s electrons are spinning. Reinhard s team placed different kinds of samples onto their diamond
and watched how the nuclear resonance in them influenced the spinning electrons in the nitrogen. The researchers worked out that most of the signal came from a volume just 5 nanometres across inside the sample.
which allowed them to manipulate the electrons of hydrogen atoms inside it. That was much more like a conventional NMR experiment,
bacteria accounted for around 20%of all particles#biological and non-biological#a higher proportion than in the near-Earth atmosphere."
when water molecules in the air coalesce around a seed particle, often dust or soot. Depending on temperature, these complexes can grow into large water droplets or frozen balls of ice,
the water s oxygen atoms share some of their electrons with vacant electron orbitals on the aluminium atoms,
and the oxygens in the ceramic share their electrons with hydrogen in the water. This binds the two together.
But what if a ceramic failed to accept electrons from water? Then the ceramic might actually be reasoned hydrophobic
The lanthanides'empty orbitals are buried beneath shells of other electrons, which should make them much less attractive to water s oxygen,
Researchers working with nanoscale fluorescent particles called quantum dots have predicted long groundbreaking achievements, such as ultra-efficient light-emitting diodes (LEDS) and solar cells,
and size affect the quantum properties of their electrons, in particular their energy gap#the energy needed to kick electrons into a higher energy band#which determines the colour of light that the mater#ial can emit.
Whereas a bulk semiconductor is limited to emitting a single colour of light researchers can tune the precise colour a quantum dot will absorb
Current atomic clocks are based on the microwave signals emitted by electrons inside an atom as they move from one energy level to another.
But those internal atomic oscillations are determined by the interactions between the atom s electrons and its nucleus
M#ller and his colleagues say that their work goes back to the basics of quantum mechanics#to Arthur Compton's demonstration in 1923 that X-ray photons can deliver a detectable momentum impulse to an electron,
and to Louis de Broglie's subsequent insight that moving electrons (and atoms) behave like waves.
The characteristic Compton frequency used to describe these matter waves is around 1020 Hz for an electron,
or tiny laser-photon impacts, which slow the Compton cycles by a precisely known amount.
"involves a reference using at least two particles that interact. This Compton clock is the first to be based entirely on a single particle s mass.
That means that the device, which in principle can be built with a single atom, M#ller says,
#Electron beams set nanostructures aglow Put a piece of quartz under an electron microscope and it will shine an icy blue.
But the light#emitted after a beam of electrons kicks a material s own electrons into a higher energy state#is faint and diffuse,
The technique combines the advantages of optical and electron-based imaging. An electron beam can in principle achieve a resolution of less than one nanometre,
compared with hundreds of nanometres for a beam of light. But maps made by scattered or reflected electrons are not typically sensitive to the way light behaves in the sample.
Cathodoluminescence, by contrast, can map the interaction of light and matter#but, because it is triggered by a narrow beam of electrons,
it promises the same nanometre scale resolution that those systems can achieve.""This has opened the door to understanding how light couples to matter in a more fundamental way,
The device includes a carefully shaped parabolic mirror that collects photons as they emerge from a sample bombarded with electrons.
Just as in an old-fashioned cathode ray tube-tube colour television, the electron beam scans the sample to build up an image line by line.
Physicists later realized that the absolute temperature of a gas is related to the average energy of its particles.
which particles have no energy at all, and higher temperatures correspond to higher average energies. However, by the 1950s, physicists working with more exotic systems began to realise that this isn't always true:
Technically, you read off the temperature of a system from a graph that plots the probabilities of its particles being found with certain energies.
Normally, most particles have average or near-average energies, with only a few particles zipping around at higher energies.
In theory, if the situation is reversed, with more particles having higher, rather than lower energies, the plot would flip over
and the sign of the temperature would change from a positive to a negative absolute temperature,
electrically charged particles, corralled into separate doughnut-shaped rings by Earth s magnetic field. The outer ring orbits at a distance of some 10,000-60,000 kilometres above Earth,
and encircles an inner band of even more energetic particles, roughly 100-10,000 kilometres above Earth.
narrow belt of charged particles sandwiched between the inner ring and a now highly eroded outer ring."
however, and Baker and his team now attributes its creation to an interplanetary shock wave#a travelling outburst of solar-wind particles from the Sun#that has been detected by other craft.
"It s a new way of trying to get the immune system to prevent phagocytosis of drugs or particles.
when a proton binds to the MATE protein at a spot on its extracellular side, one of the protein's segments switches from a straight to a bent shape to push any nearby foreign molecule out of the cell1."
"They have a direct mechanism of how the protons change the shape of the cavity.
The map even shows that the number of neutrino flavours permeating the cosmos will probably remain at three#had there been a fourth,
particles such as protons and electrons formed from the cauldron of proto-matter, and photons began to bounce around like pinballs.
It was only 380,000#years later, when the charged plasma cooled into neutral atoms, that those photons could fly freely.
Today they make up the CMB, and carry with them an imprint of the quantum fluctuations that roiled the inflationary Universe.
That transition allowed photons to travel unimpeded through space, in a pattern that carried the echoes of inflation.
Those photons are still out there today as a dim glow of microwaves with a temperature of just 2. 7 kelvin.
Researchers have developed a microscopic device that can detect the ebb and flow of electrons within an alga as it photosynthesizes.
The device is known as a single-electron transistor, and its inventors hope that it could be used to measure the performance of biofuel-producing organisms,
for example#a single electron can switch the transistor on, amplifying a tiny signal into a much larger current in the main circuit.
The first single-electron transistors were built in the late 1980s1, but most require very low temperatures#otherwise, the electrons gather enough energy to tunnel through the semiconductor,
and current leaks through the switch. A handful work at room temperature (by using carbon nanotubes to detect electrons
for example2), but they cannot operate in water#a serious obstacle to using such devices in living organisms.
In 2008, materials scientist Ravi Saraf at the University of Nebraska-Lincoln and his colleagues built a room-temperature single-electron transistor using a different approach3.
But if an electron settles on a defective nanoparticle it makes it slightly easier for current to flow,
"That s something really new, says Simon. The cells sit on the surface of the gold#nano particles,
Shining a light on the cells triggers a cascade of biochemical reactions that transfer electrons along a chain of molecules#and switches the transistor on.
they zeroed in first on a small area of the hypothalamus known as the arcuate nucleus,
and more recently on Agrp and POMC neurons, two small populations of cells within that nucleus. These two groups of cells,
#Tau Associated MAPT Gene Increases Risk for Alzheimer's disease A international team of scientists, led by researchers at the University of California,
San diego School of medicine, has identified the microtubule associated-protein protein tau (MAPT) gene as increasing the risk for developing Alzheimer disease (AD).
the role of the tau-associated MAPT gene is said still unclear Rahul S. Desikan, MD,
and more likely to experience increased brain atrophy than non-carriers. his study demonstrates that tau deposits in the brains of Alzheimer disease subjects are not just a consequence of the disease,
since Alois Alzheimer time that both plaques (with amyloid) and tangles (of tau) are key features of Alzheimer pathology,
Until this year no one had shown convincingly that the MAPT (tau) gene altered the risk of AD and this,
combined with the greater ease of imaging amyloid in life, lead some researchers to postulate that tau changes were secondary to amyloid changes.
The recent association of genetic variation in the MAPT gene with AD risk and the emerging availability of tau imaging are now leading to a recognition that perhaps tau changes are key in the pathophysiologic pathway of AD
This is controlled by balancing the activity of protein umpsthat push protons into endosomes to increase their acidity with that of protein eaks
like NHE9, that remove protons. Rao says: ndosomes are like buckets of water that have to be kept full despite the leaks in them.
which pump out too many protons (orange), changing the endosomesacidity and slowing their hipping speed.
causing endosomes to leak too many protons and become too alkaline. This slows down the hipping rateof cancer-promoting cargo and leaves them on the cell surface for too long.
AD cortical nuclei displayed large variability with average DNA content increases of? 8%over non-diseased controls that were unrelated to trisomy 21.
Secondly, the particles can be triggered by an outside magnetic field to produce an electric field when adjacent to individual neurons.
and pollution particles in the sky left behind by jet aircraftctually are signs of a clandestine government effort to modify the weather.
#'Edible Barcodes'Help Fight Counterfeit Drugs Who knew that the answer to fighting the trillion-dollar global counterfeit drug problem rested in a particle the size of a speck of dust?
Within each of the tiny particles is an elaborate nanopore structure think of it as a series of microscopic holes within a thin membrane,
Wuh said the idea of tiny microscopic particles containing data about a drug is farfetched no more than someone 20 years ago saying that a person would have a upercomputer the size of his palm. ut,
000 cubic feet of air--42 percent of which is made of carbon particles. One tower alone is capable of cleaning 123 million cubic feet of clean air per day.
Holding up a bag of pollution particles in this video, he explains that it hard to believe that we accept this pollution as waste
but a more refined approach might allow researchers to standardize the size of diamond particles
Another common approach to levitation involves filling an object with iron oxide particles. But that would be toxic to living cells.
They laced the fluid with particles of gadolinium a rare-earth metal that is highly magnetic and sometimes given to patients to increase contrast in an MRI.
The magnetic field is shaped to pull the gadolinium downward so metal particles push the cells upward,
#Strange new subatomic particles discovered at atom smasher Exotic subatomic particles made up of five quarks that physicists briefly thought they had discovered back in 2003 now finally appear to be in the bag.
who claim to have found conclusive evidence for the existence of so-called pentaquarks within the debris of high-energy proton collisions.
The discovery has filled a big hole"in the theory that describes how matter is built up from the fundamental particles known as quarks,
describes how the protons and neutrons that make up atomic nuclei are composed themselves of three quarks and how other particles known as mesons are made from pairs of quarks and their antimatter counterparts, antiquarks.
However, Gell-Mann's scheme also pointed to the existence of pentaquarks, made up of four quarks and an antiquark.
The lack of any evidence for such particles over the past 50 years says Wilkinson,
"didn't throw the theory into disrepute but was becoming increasingly troublesome.""To catch the elusive prey,
Wilkinson and colleagues studied the decay of"lambda-b"particles created by protons colliding within LHCB.
They measured the combined energy of two of the decay products proton and a meson known as J/Psi,
which consists of a"charm quark and antiquarknd then totted up how many times they recorded each energy value across the thousands of collisions they studied.
They found that the number of pairings with a certain energy little under five times the mass of the protonas far higher than would be expected by chance.
The researchers concluded that that was the mass of a fleeting"charmonium"pentaquark containing two up quarks, one down quark, one charm quark,
and one anticharm quark. LHCB collected the data back in 2011 and 2012, but Wilkinson's team held back from announcing their discovery to avoid the fate of those who had made the earlier claims of pentaquark sightings.
the LHCB collaboration made use of data showing not only the energy of the particles produced in the CERN collisions but also their directions.
For comparison, a proton weighs in at 0. 94 Gev. The research has been uploaded to the arxiv server
"They appear to have found strong evidence for a'heavy quark'pentaquark state, "says Ken Hicks of Ohio University.
whether all five quarks are bound tightly together inside the new particle, or whether instead three quarks group together as they do inside protons
and neutrons and the other two form a separate meson bit like two atoms combining to form a molecule.
Wilkinson says that because pentaquarks might be formed inside collapsing stars, their discovery might tell us more about what stars are composed of
"Now that we know nature allows five quarks to be bound together, it would be very strange indeed
if just this set of quarks is allowed to coexist in this manner, "he says.""There should be many others.
or cathode, where oxygen molecules pick up extra electrons. These oxygen ions then travel through the membrane to the positively charged anode.
Additional radio signals cause the protons in your body's liquids to resonate with the magnetic field
The pulses make protons in the body spin in a precise way that sends signals that can be interpreted as the location and density of fluid in the bones and muscle.
The effect may be the first time that a lab-based black hole has created Hawking particles in the same way expected from real black holes.
But in 1974 Stephen Hawking of the University of Cambridge predicted they should emit a faint glow of particles now known as Hawking radiation.
but fizzes with pairs of particles and their antimatter counterparts. Normally these pairs annihilate each other
of which trapped photons using laser pulses in a fibre optic-cable cable. The team claimed this had produced Hawking radiation
The horizons create pairs of particles of sound or phonons. One phonon escapes the horizon
The device zaps water with electricity to release oxygen then a silicon-based chemical mediator dissolved in the water mops up stray protons and electrons.
When the hydrogen is needed putting the mediator in contact with a platinum catalyst allows those electrons
and protons to recombine to make hydrogen gas. The whole process uses a single whack of power and patchy renewable energy will suffice for this says Cronin.
An unexpected pattern has been glimpsed in the solar wind the turbulent plasma of charged particles that streams from the sun. It offers clues for handling plasmas that roil inside nuclear fusion reactors On earth.
Composed of charged particles such as protons and electrons the solar wind streams from the sun and pervades the solar system.
Its flow is turbulent containing eddies and moving at different speeds in different directions. It was thought that this turbulence was similar to that in a fluid behaving like mixing ocean currents
when the movement of the wind's particles is perpendicular to the sun's magnetic field they resemble a fluid with sections that are smooth interrupted by bursts of violence.
But when the particles move in parallel with the field lines they behave very differently with the turbulence evenly spread like crinkly mountains that extend as far as the eye can see (see diagram.
These create energy in the same way as the sun by fusing a superheated plasma of hydrogen nuclei to form helium.
or align the electromagnetic fields of photons they came into contact with in the infant universe.
Those photons which have been travelling through space ever since appear in every direction in the sky as the cosmic microwave background (CMB) radiation.
But other things apart from gravitational waves such as dust can emit polarised photons. To minimise the chances of this effect causing a false signal the BICEP 2 team pointed their telescope at a patch of sky far away from the Milky way's dusty disc.
If the aligned dust contains iron the particles'slight vibrations due to their own heat would produce polarised microwave radiation says Mertsch.
if you take the dust into account along with emissions from charged particles in the galaxy
which protects us from the bulk of the solar wind a stream of high-energy particles constantly flowing from the sun
Charged particles can flow along these lines into Earth's atmosphere leading to dazzling auroras as well as geomagnetic storms that can wreak havoc on navigation systems and power grids.
In January 2013 GPS sensors on the ground mapped electrons in the upper atmosphere and saw a tendril of increased electron density curling away from the north pole indicating that a plume of plasma was veering off towards the sun. At the same time three of NASA's THEMIS spacecraft
which are designed to study solar storms crossed through the magnetic boundary during the event. The craft saw a 100-fold increase in the number of electrons at the boundary
which would probably have been deposited by the plume. For the first time we were able to monitor the entire cycle of this plasma stretching from the atmosphere to the boundary between Earth's magnetic field
Mirin made a nanowire detector that operates at-270 C. This boosted the number of photons it received each second by two orders of magnitude compared with regular detectors.
#Boxy Cubesats get a propulsion boost in new space race Tiny liquid volcanoes that spray beams of charged particles could make space history next year.
But we also know that the sun pumps out a constant stream of charged particles called the solar wind
and pick up the newly charged particles effectively sweeping them away. Earth is protected from the solar wind by a relatively strong global magnetic field
which repels charged particles from the sun explains Nick Schneider of the Laboratory for Atmospheric
Choreographed high-power lasers or electron beams can fuse and sculpt metal powders into high-performance machine parts.
At the same time a stream of particles blowing out from the sun the solar wind inflates a bubble of plasma around the solar system called the heliosphere Astronomers have assumed long that the sun's motion through the galaxy squashes
when charged particles from the solar wind collide with other charged particles in the outer heliosphere Some of these neutral atoms are bounced back towards us.
if we were to look straight down the length of the tail from front to back we would see particles clustered into four distinct lobes like a four-leaf clover (see image above right).
Two opposing lobes on the vertical plane consist of fast-moving particles while the two lobes on the horizontal plane consist of slower-moving particles (watch a NASA video of the tail in action).
The four lobes might be a reflection of solar activity at the time the particles left the sun says IBEX principal investigator David Mccomas. The particles took a few years to reach the tail
so they were born when the sun was minimally active. Around solar minimum you get slow solar wind around low to mid-latitudes from the sun
. But he expected this would create more of a solid horizontal band of slow particles across the tail not the odd lobes.
At solar maximum the bands of slow and fast particles streaming away from the sun break down so the tail may change its shape
The magnetic field of the heliosphere protects us from the bulk of these galactic high-energy particles. But some manage to impinge on our solar system
#Tabletop accelerator shoots cheap antimatter bullets Make way for the antimatter gun. A tabletop device just 10 square metres in size can spit out energetic bursts of positrons as dense as those kicked out by the giant particle-factories at CERN.
Each positron-packed bullet lasts for just a fraction of a second so don't expect to fill the tank of your antimatter engine any time soon.
Instead the smaller cheaper machine might help labs around the world study deep-space objects such as powerful radiation jets squirted out by black holes.
Antiparticles have the same mass as their ordinary particle counterparts but carry an opposite charge and spin.
The particles annihilate on contact with ordinary matter vanishing in a puff of energy which makes it difficult to produce
Huge machines at particle physics labs such as CERN near Geneva Switzerland have been churning out antimatter for over a decade.
Instead Gianluca Sarri at Queen's university Belfast UK and colleagues used rapid laser bursts to make positrons in their smaller budget device.
The laser pulse ionises inert helium gas generating a stream of high-speed electrons. This electron beam is directed at a thin metallic foil
so that it crashes into metal atoms releasing a jet of electrons and positrons. These particles are separated into two beams with magnets (Physical Review Letters doi. org/m2n.
The team call their device an antimatter gun because the bursts of positrons last just 30 femtoseconds (quadrillionths of a second).
Despite their short duration the beams contain a quadrillion positrons per cubic centimetre says Sarri meaning they are comparable in density to the ones made at CERN.
In 2008 scientists at the Lawrence Livermore National Laboratory in California produced large quantities of antimatter by directing an extremely powerful laser at a tiny gold disc.
Sarri says his setup is much more practical and cheaper: They needed much stronger lasers
and those lasers are expensive. Also they produced streams of positrons that were extremely broad
whereas our jet is a hundred times narrower and remains pencil-like as it propagates he adds.
This is similar to the powerful streams of matter-antimatter observed outside pulsars and black holes. CERN physicist Niels Madsen notes though that the tabletop device has limitations.
It only makes relatively light particles like positrons whereas to make an anti-atom you also need antiprotons
which are almost 2000 times more massive. For now he says making heavier antiparticles is not doable in a small lab in a cheap fashion.
Nor does the smaller machine address the problem of antimatter storage. To hold antimatter stable it must be chilled
and the tabletop method makes searing-hot beams of particles moving at near light speed. As an alternative says Sarri the beams can be used to mimic the way particle fountains from black holes
and pulsars shoot through and interact with gases in the interstellar medium creating mini versions of these enigmatic astrophysical phenomena in the lab for the first time.
This article will appear in print under the headline Antimatter bullets get fast and chea a
#China inches closer to building its own space station Update 11 june 2013: The China National Space Administration successfully launched its Shenzhou-10 mission to low Earth orbit at 0938 GMT today.
The Long March 2f rocket lifted off flawlessly from the Jiuquan space centre in Mongolia's Gobi desert
and headed towards the fledgling spacefaring nation's space station Tiangong 1 around which it is expected to test manoeuvres before docking for a 15-day stay on orbit.
If you can grow large particles they will disappear very quickly says Nienke van der Marel of Leiden Observatory in The netherlands.
It means there must be some mechanism that is keeping the large dust particles there because they're not drifting inwards.
and minerals that could act like batteries allowing electrons to flow and bring energy to any potential organisms.
and gained electrons and so could have acted as microbial energy sources. All these clues point to ancient Mars hosting neutral slightly salty liquid water that could have supported primitive life.
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