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Scooped by Dr. Stefan Gruenwald!

New kind of hologram creates strange state of light at visible and invisible wavelengths

New kind of hologram creates strange state of light at visible and invisible wavelengths | Amazing Science |

Applied physicists at the Harvard School of Engineering and Applied Sciences (SEAS) have demonstrated that they can change the intensity, phase, and polarization of light rays using a hologram-like design decorated with nanoscale structures.


As a proof of principle, the researchers have used it to create an unusual state of light called a radially polarized beam, which—because it can be focused very tightly—is important for applications like high-resolution lithography and for trapping and manipulating tiny particles like viruses.


This is the first time a single, simple device has been designed to control these three major properties of light at once. (Phase describes how two waves interfere to either strengthen or cancel each other, depending on how their crests and troughs overlap; polarization describes the direction of light vibrations; and the intensity is the brightness.)


“Our lab works on using nanotechnology to play with light,” says Patrice Genevet, a research associate at Harvard SEAS and co-lead author of a paper published this month in Nano Letters. “In this research, we’ve used holography in a novel way, incorporating cutting-edge nanotechnology in the form of subwavelength structures at a scale of just tens of nanometers.” One nanometer equals one billionth of a meter.


Genevet works in the laboratory of Federico Capasso, Robert L. Wallace Professor of Applied Physics and Vinton Hayes Senior Research Fellow in Electrical Engineering at Harvard SEAS. Capasso’s research group in recent years has focused on nanophotonics—the manipulation of light at the nanometer scale—with the goal of creating new light beams and special effects that arise from the interaction of light with nanostructured materials.

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Hydractinia echinata has the power to regenerate any lost body part, can clone itself and does not age

Hydractinia echinata has the power to regenerate any lost body part, can clone itself and does not age | Amazing Science |

A small, native-Irish marine animal with remarkable powers of regeneration has provided stem cell scientists studying congenital defects and cancer biology with significant new leads.


Hydractinia echinata has the power to regenerate any lost body part, can clone itself, does not age biologically, and, according to Dr Uri Frank, who is leading the research at NUI Galway’s regenerative medicine institute, “in theory - lives forever”.


The tiny creature, which is a relative of jellyfish and sea anemones, is “perfect for understanding the role of stem cells in development, ageing and disease,” says Dr Frank.


“Hydractinia has some stem cells which remain at an embryonic-like stage throughout its life. It sounds gruesome, but if it has its head bitten off, it simply grows another one within a few days using its embryonic or ‘pluripotent’ stem cells”, explains Frank. “So the potential for research is immense”, he adds.


The Galway team has discovered an unknown link between ‘heat-shock’ proteins and a cell-signalling pathway, known as Wnt signalling, in Hydractinia stem cells. “These two cellular signalling mechanisms are known to play important roles in development and disease, so they have been widely, though separately, studied. We have shown that they talk to each other, providing a new perspective for all scientists in this field,” says Dr Frank. “We found the link coincidentally - we weren’t looking for it.”

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1,000 mile wide magnetic super tornadoes rage on the Sun

1,000 mile wide magnetic super tornadoes rage on the Sun | Amazing Science |

The discovery of "super-tornadoes" rising above the surface of the sun may help solve the mystery of how our home star heats it wispy outer atmosphere to a million degrees. There is plenty of energy below the 5780° visible surface to do the job, but solar physicists have long argued about how that energy heats the corona, seen as an encircling crown of light that emerges during a total solar eclipse. Now a group reports online today in Nature that, using both spaceborne and ground-based telescopes, it has detected 1500-kilometer-wide swirls of solar atmosphere rising from the surface into the corona.


Each lasts 10 to 15 minutes, and there are about 11,000 of them on the sun at a time. Computer simulations (picture) show how similar-looking the twisting magnetic field lines of a solar tornado are to real tornadoes. Now solar physicists must figure out how much energy super-tornadoes deliver compared with other proposed energy sources.

Jim Doyle's curator insight, August 21, 2013 6:19 AM

That is what you call a storm

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Cisco’s Forecast: 50 Billion Internet-Connected Devices by 2020 -- Too Conservative?

Cisco’s Forecast: 50 Billion Internet-Connected Devices by 2020 -- Too Conservative? | Amazing Science |
As a tech memes go, the Internet of Things is getting a bit long in tooth. The idea of internet-connected smart stuff has been heralded for years now. But where exactly are we in the quest to connect all things?


According to Cisco, there are an estimated 1.5 trillion things in the world (no mention of exactly how they counted those things, but let’s go with it) and approximately 8.7 billion, or 0.6%, were connected in 2012. The firm expects a 25% annualized decrease in price to connect between 2012 and 2020 and a matching 25% annualized increase in connectivity. That means we can expect 50 billion connected things by 2020, with 50% of those connections happening in the final three years of the decade.


Fifty billion sounds like a big number, but one could argue Cisco’s forecast is pretty conservative. Of their estimated 1.8 trillion total things in 2020, 50 billion would be a mere 2.7% of the total. Yes, it’s an increase from 2012′s 0.6%—but a fairly modest increase as these things go. Cisco is a big company, and it pays to be careful.


Maybe we can go out on a limb where Cisco can’t. The firm bases its projected annualized growth rate primarily on the decreasing price to connect. But there are other drivers too—the declining price and increasing power of embedded chips, for example. Or rapidly improving “big data” software that makes all that new information useful, and therefore more highly demanded.


In a world of exponential technology, things can move faster than our linear brains can fathom. If the number of connected things grew at twice Cisco’s predicted annualized rate, we’d have 223 billion connected things, or 12% of the total, by 2020. At a little less than quadruple Cisco’s forecast, we’d be talking 1.5 trillion connected things, or 82% of the total, by the end of the decade.

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Most powerful magnetic field in universe that is 40 trillion times stronger than Earth's

Most powerful magnetic field in universe that is 40 trillion times stronger than Earth's | Amazing Science |
The strongest magnetic field in the universe has potentially been discovered – a dead star that packs the equivalent mass of our sun into an area just 12 miles across.


The former star, which has the catchy name SGR 0418+5729, is 6,500 light years from Earth and was initially thought to have an unusually low magnetic field. New observations using the European Space Agency’s XMM Newton Space Telescope have, however, revealed that it may be the strongest magnetic source in the known universe.


Astronomers calculated that SGR 0418 must have a magnetic field of more than 1 quadrillion, or 1,000 trillion, gauss, the unit used to measure the strength of a magnetic field. By comparison, the iron core of the Earth is thought to have a magnetic field of 25 gauss.


Physicists have estimated that the upper limit for a magnetar would be 100 quadrillion gauss, but none have been found to be this powerful yet.


“To explain our observations, this magnetar must have a super-strong, twisted magnetic field reaching 10E15 Gauss across small regions on the surface, spanning only a few hundred meters across,” said Dr Tiengo.


“On average, the field can appear fairly weak, as earlier results have suggested. But we are now able to probe substructure on the surface and see that the field is very strong locally.”


The researchers, whose findings are published in the journal Nature, now hope the new technique may help them discover other hidden magnetars and may help reveal more about those that have already been identified.


Norbert Schartel, ESA’s XMM-Newton project scientist, said: “The spectral data provided by XMM-Newton, combined with a new way of analysing the data, allowed us to finally make the first detailed measurements of the magnetic field of a magnetar, confirming it as one of the largest values ever measured in the universe."


“We now have a new tool to probe the magnetic fields of other magnetars, which will help constrain models of these exotic objects.”

CineversityTV's curator insight, August 19, 2013 1:14 PM

till now.

CineversityTV's curator insight, August 19, 2013 1:15 PM

till now

Peter Phillips's curator insight, August 19, 2013 5:58 PM

Science geek food - pure. Waiting to hear more about this one.

Rescooped by Dr. Stefan Gruenwald from Bio-informatics!

Global deep ocean sequencing endeavor reveals a wealth of unknown species

Global deep ocean sequencing endeavor reveals a wealth of unknown species | Amazing Science |

Biologists have started to sequence the genome of the global deep ocean. They are using more than 2,000 samples of microorganisms collected in the Atlantic, Indian and Pacific Oceans during the Malaspina Expedition.


This collection of marine microbial genomic, the first in the world on a global scale, will provide new clues about a reservoir of biodiversity yet to explore, considering that it could imply the discovery of tens of millions of new genes in the coming years.


The works of sequencing (framed in the Malaspinomics project) focus on the viruses, bacteria and protists that inhabit the ocean to 4,000 meters deep. Most of the biomass of marine organisms is composed of microorganism. Of these, a 72% inhabit the dark ocean, from 200 meters deep. However, so far, the DNA or RNA sequencing had been almost exclusively limited to the ocean surface waters.


Malaspinomics preliminary results reveal a wealth of unknown species of microorganisms in the deep ocean, characterized by an intense biological activity. Specifically, 60% of the bacterial species of the deep ocean detected by massive sequencing techniques are unknown.


According to Josep Maria Gasol, CSIC researcher at the Institute of Marine Sciences and leader of the Malaspina block of microorganisms, samples "are especially valuable because they come from areas that have been poorly studied in a scientific sense up to now, such as the Indian and South Pacific Oceans. Recent evidences suggest that the deep ocean contains active and highly diverse bacteria, as well as archaea, protists, viruses and zooplankton."


Jesús María Arrieta, CSIC researcher at the Mediterranean Institute for Advanced Studies, explains: "The number of marine species used as a source of genes with commercial interests grows at a rate of 12% per annum. The biotechnological potential of marine organisms is immense, especially in the deep ocean. We hope that the genes collected in Malaspina Expedition open the door to multiple biotechnological applications in fields such as bioenergy, food or cosmetics.

Via Ed Rybicki, Loiret David
Ed Rybicki's curator insight, August 12, 2013 3:35 AM

Viruses: they'll find lots of viruses.  But they may well miss the ssRNA and small ssDNA viruses - and it'll have to be done again....

Gretel Posadas's curator insight, August 23, 2013 8:19 AM

#Malaspinomics preliminary results reveal a wealth of unknown species of microorganisms in the deep ocean, characterized by an intense #biologicalactivity. Specifically, 60% of the bacterial species of the deep ocean detected by massive sequencing techniques are unknown.

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Extinct frog on the verge of revival after injection of 'dead' cell nucleus into an egg from another frog species

Extinct frog on the verge of revival after injection of 'dead' cell nucleus into an egg from another frog species | Amazing Science |

Scientists create living embryo of extinct frog that gives birth through its mouth. Although the resulting embryos lived for just a few days, the groundbreaking research by an international team has brought the 'de-extinction' of creatures like woolly mammoths a step closer. The scientists working for the so-called Lazarus Project are yet to publish their results, but say future barriers to bringing the frog back to life are 'technological, not biological'.


The last of the bizarre gastric-brooding frog, Rheobatrachus silus – which uniquely swallowed its eggs, brooded its young in its stomach and gave birth through its mouth – died out in 1983.


The woolly mammoth could again be walking the Siberian steppes in less than 20 years, scientists say. Teams from around the world are racing to sequence the mammoth genome from an analysis of DNA from remains found frozen in the ice of northern Russia.


George Church, a geneticist at Harvard University, says that despite the animals dying out nearly 4,000 years ago, it could still be possible to extract usable DNA from mammoths preserved in the permafrost.


An exact picture of the mammoth genome would be used as a template to edit and rewrite the genetic make-up of the closely related Asian elephant until it matched, the Siberian Times reported him as saying.


Hendrik Poinar, associate professor at McMaster University in Canada, added: 'We can actually pull out and rejig all these small mammoth fragments and match them against the genome of an Asian or African elephant chromosome and find all the little points of difference.


'So that means we can take Asian elephant chromosomes, modify them to match that of a mammoth and then create an embryo by inseminating an Asian elephant egg. 


'It would be long and arduous but eventually we would have something that looked like a mammoth. It would not be an exact replica but it would look and feel much like a woolly mammoth did.'


The last mammoths died out some 4,000 years ago on Wrangel Island, between the East Siberian and Chukchi seas. The most likely habitats for re-born mammoths would be north-eastern Russia and northern Canada.


But researchers were able to recover cell nuclei from R. silus tissues collected in the Seventies and kept for 40 years in a conventional deep freezer. In repeated experiments over five years, the researchers used a laboratory technique known as somatic cell nuclear transfer.


Using a method similar to that imagined in the blockbuster Jurassic Park, they took fresh eggs from the distantly related Great Barred Frog, deactivated their nuclei and replaced them with genes from the extinct frog.


Some of the eggs spontaneously began to divide and grow to early embryo stage – a tiny ball of many living cells from a creature extinct for 30 years.

Although none of the embryos survived beyond a few days, genetic tests confirmed that the dividing cells contain the genetic material from the extinct frog.


'We are watching Lazarus arise from the dead, step by exciting step,' said Mike Archer, a professor at the University of New South Wales and the leader of the Lazarus Project team.


'We’ve reactivated dead cells into living ones and revived the extinct frog’s genome in the process. Now we have fresh cryo-preserved cells of the extinct frog to use in future cloning experiments.

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Funneling a broader spectrum of the sun’s energy

Funneling a broader spectrum of the sun’s energy | Amazing Science |

The quest to harness a broader spectrum of sunlight’s energy to produce electricity has taken a radically new turn, with the proposal of a “solar energy funnel” that takes advantage of materials under elastic strain.

“We’re trying to use elastic strains to produce unprecedented properties,” says Ju Li, an MIT professor and corresponding author of a paper describing the new solar-funnel concept that was published recently in the journal Nature Photonics.

In this case, the “funnel” is a metaphor: Electrons and their counterparts, holes — which are split off from atoms by the energy of photons — are driven to the center of the structure by electronic forces, not by gravity as in a household funnel. And yet, as it happens, the material actually does assume the shape of a funnel: It is a stretched sheet of vanishingly thin material, poked down at its center by a microscopic needle that indents the surface and produces a curved, funnel-like shape.

The pressure exerted by the needle imparts elastic strain, which increases toward the sheet’s center. The varying strain changes the atomic structure just enough to “tune” different sections to different wavelengths of light — including not just visible light, but also some of the invisible spectrum, which accounts for much of sunlight’s energy. 

Li, who holds joint appointments as the Battelle Energy Alliance Professor of Nuclear Science and Engineering and as a professor of materials science and engineering, sees the manipulation of strain in materials as opening a whole new field of research.

Strain — defined as the pushing or pulling of a material into a different shape — can be either elastic or inelastic. Xiaofeng Qian, a postdoc in MIT’s Department of Nuclear Science and Engineering who was a co-author of the paper, explains that elastic strain corresponds to stretched atomic bonds, while inelastic, or plastic, strain corresponds to broken or switched atomic bonds. A spring that is stretched and released is an example of elastic strain, whereas a piece of crumpled tinfoil is a case of plastic strain.

The new solar-funnel work uses precisely controlled elastic strain to govern electrons’ potential in the material. The MIT team used computer modeling to determine the effects of the strain on a thin layer of molybdenum disulfide (MoS2), a material that can form a film just a single molecule (about six angstroms) thick.

Unlike graphene, another prominent thin-film material, MoS2 is a natural semiconductor: It has a crucial characteristic, known as a bandgap, that allows it to be made into solar cells or integrated circuits. But unlike silicon, now used in most solar cells, placing the film under strain in the “solar energy funnel” configuration causes its bandgap to vary across the surface, so that different parts of it respond to different colors of light.

In an organic solar cell, the electron-hole pair, called an exciton, moves randomly through the material after being generated by photons, limiting the capacity for energy production. “It’s a diffusion process,” Qian says, “and it’s very inefficient.” 

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MIT: How to make big things out of small interlocking composite components

MIT: How to make big things out of small interlocking composite components | Amazing Science |

MIT researchers have developed a lightweight structure whose tiny blocks can be snapped together much like the bricks of a child’s construction toy. The new material, the researchers say, could revolutionize the assembly of airplanes, spacecraft, and even larger structures, such as dikes and levees.

Neil Gershenfeld, director of MIT’s Center for Bits and Atoms, likens the structure — which is made from tiny, identical, interlocking parts — to chainmail. The parts, based on a novel geometry that Cheung developed with Gershenfeld, form a structure that is 10 times stiffer for a given weight than existing ultralight materials. But this new structure can also be disassembled and reassembled easily — such as to repair damage, or to recycle the parts into a different configuration.

The individual parts can be mass-produced; Gershenfeld and Cheung are developing a robotic system to assemble them into wings, airplane fuselages, bridges or rockets — among many other possibilities.

The new design combines three fields of research, Gershenfeld says: fiber composites, cellular materials (those made with porous cells) and additive manufacturing (such as 3-D printing, where structures are built by depositing rather than removing material).

With conventional composites — now used in everything from golf clubs and tennis rackets to the components of Boeing’s new 787 airplane — each piece is manufactured as a continuous unit. Therefore, manufacturing large structures, such as airplane wings, requires large factories where fibers and resins can be wound and parts heat-cured as a whole, minimizing the number of separate pieces that must be joined in final assembly. That requirement meant, for example, Boeing’s suppliers have had to build enormous facilities to make parts for the 787.

Pound for pound, the new technique allows much less material to carry a given load. This could not only reduce the weight of vehicles, for example — which could significantly lower fuel use and operating costs — but also reduce the costs of construction and assembly, while allowing greater design flexibility. The system is useful for “anything you need to move, or put in the air or in space,” says Cheung, who will begin work this fall as an engineer at NASA’s Ames Research Center. 

The concept, Gershenfeld says, arose in response to the question, “Can you 3-D print an airplane?” While he and Cheung realized that 3-D printing was an impractical approach at such a large scale, they wondered if it might be possible instead to use the discrete “digital” materials that they were studying.

“This satisfies the spirit of the question,” Gershenfeld says, “but it’s assembled rather than printed.” The team is now developing an assembler robot that can crawl, insectlike, over the surface of a growing structure, adding pieces one by one to the existing structure.

Ruth Obadia's curator insight, August 17, 2013 1:51 PM

MIT researchers have developed a lightweight structure whose tiny blocks can be snapped together much like the bricks of a child’s construction toy.

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Newly discovered pulsar may explain odd behavior of Milky Way's supermassive black hole in center

Newly discovered pulsar may explain odd behavior of Milky Way's supermassive black hole in center | Amazing Science |
A strange type of star never before found near the Milky Way’s center is providing new clues about the bizarre behavior of the supermassive black hole lurking at the heart of our galaxy.


The black hole, known as Sagittarius A* (Sgr A* for short), is as massive as 4 million suns and is thought to have played a critical role in shaping the Milky Way. Yet it somehow devours only a tiny fraction of its available food supply—a smorgasbord of gas and dust cast off by nearby stars, notes radio astronomer Heino Falcke of Radboud University Nijmegen in the Netherlands.


That’s a puzzle astronomers have been trying to solve for years. Observations of an elderly, rapidly rotating star known as a pulsar in the vicinity of Sgr A* have now provided the first sensitive measure of the magnetic field associated with the black hole. The strength of that field may help account for Sgr A*’s poor eating habits, Falcke and his colleagues report online today in Nature.


Pulsars reveal the magnetic field in neighboring reaches of space because they typically emit polarized light—radio waves that vibrate in a particular plane as they travel through space. When the waves pass through a magnetized region, the polarization changes direction in proportion to the strength of the local magnetic field.


Using Effelsberg and several other radio telescopes to measure the polarization of the pulsar, the team found that the magnetic field near the star is at least 2.6 milligauss. Although that’s only about 2% of the magnetic field at the surface of Earth, it’s still surprisingly large, Falcke says. Moreover, much closer to the black hole, the field could be as great as several hundred gauss, the team estimates.


“We always knew the magnetic field was important but we never quite knew how strong to dial it in in our models,” says theoretical astrophysicist Christopher Reynolds of the University of Maryland, College Park, who was not part of the study. Gas and dust pulled close to a black hole resists falling directly into the gravitational maw because it possesses rotational energy, or angular momentum—the same reason that Earth doesn’t fall directly into the sun. Small magnetic fields generate a kind of turbulent friction that robs the gas and dust of some of its angular momentum, facilitating its infall. But according to some models, larger magnetic fields, comparable to that estimated in the new study, may act in the opposite fashion, suppressing the infall of material and potentially placing a black hole on a starvation diet, Reynolds says.


Every large galaxy is believed to house a supermassive black hole, and the masses of the galaxy and the central black hole grow in lockstep, numerous observations have shown. Gaining a better understanding of how much mass black holes accrete may therefore provide new insight on how galaxies pack on the pounds, astronomers note.

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Laser levitates tiny diamonds for the first time

Laser levitates tiny diamonds for the first time | Amazing Science |
In quite an eerie feat, physicists have floated microscopic diamonds in midair using laser beams.


Researchers have already used lasers to levitate extremely small particles, such as individual atoms, but this is the first time that the technique has worked on a nanodiamond, which, in this case, measures just 100 nanometers (3.9 x 10-8 inches) across, or more than 1,000 times thinner than a fingernail.


In the new study, the physicists from the University of Rochester relied on the fact that a laser beam, which is made up of photons, creates a tiny force that usually can't be felt.

"If we turn on a light or open a door and feel the sun, we don't feel this push or pull," study researcher Nick Vamivakas said in a video released by the university. "But it turns out that if you focus a laser down with a lens to a very small region of space, it can actually pull on microscopic, nanoscopic particles."


To force the tiny diamonds to float, Vamivakas and his colleagues focused a pair of lasers toward a clear vacuum chamber and then sprayed the diamonds into the chamber using an aerosol dispenser. The diamonds gravitated toward the light, and some eventually levitated in a stable position.


Sometimes, the levitation occurred within just a couple of minutes, while other times, the process took a bit longer. "Other times, I can be here for half an hour before any diamond gets caught," Levi Neukirch, a graduate student at the University of Rochester who was involved in the study, said in a statement. "Once a diamond wanders into the trap, we can hold it for hours."


The team hopes the findings will have applications in quantum computing and, more theoretically, help explain how friction operates on extremely small scales.

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Singing, rather than saying, phrases in a foreign language makes them easier to remember

Singing, rather than saying, phrases in a foreign language makes them easier to remember | Amazing Science |

A new study published in the journal in Memory and Cognition, has found that adults learning phrases in Hungarian were better able to match the words with their English counterparts when they learned the phrase by singing it. Lead author, linguist Dr Karen M Ludke of the University of Edinburgh, became interested in whether singing could help in learning a language when she was teaching English as a second language in New York.


"I started using a lot of song and music in my lessons, so they could practise when I wasn't around," she says. "Then I started to doubt myself a little bit. I thought, 'Is this scientific?, Is this actually beneficial to use song to teach?'"


"I started to look into it, using Google Scholar to find out what research there was out there, and I did find a lot of stuff from teachers [saying it worked], but I couldn't find anything that actually compared singing with a spoken presentation."


Ludke decided to answer the question herself and enrolled for a Masters and then a PhD. In her study, sixty people aged between 18 and 29 were split into three groups.


One group heard spoken English phrases followed by a spoken Hungarian translation, another group heard the Hungarian phrase being sung, and a third group heard the Hungarian phrases being with the same rhythm as the song, rather like a chant.


She says Hungarian was chosen as the test language because it is unfamiliar to most English speakers and it is quite different from both the Germanic languages and the Romance languages such as French and Italian.


The study results showed that people who had heard the Hungarian phrases being sung performed significantly better than the other groups. In particular, when they heard the English phrases again they were better able to repeat the correct Hungarian phrase. And they were more likely to be able to translate the Hungarian phrases back into English as well.

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Scooped by Dr. Stefan Gruenwald! 3750+ Astronomy Postings 3750+ Astronomy Postings | Amazing Science |

Astronomy is one of the oldest natural sciences and studies celestial objects (such as moons, planets, stars, nebulae, and galaxies), the physics, chemistry, mathematics, and evolution of such objects, and phenomena that originate outside the atmosphere of Earth, including supernovae explosions, gamma ray bursts, and cosmic background radiation. Theoretical astronomy is oriented towards the development of computer or analytical models to describe celestrial phenomena. A related but distinct subject, cosmology, is concerned with studying the universe as a whole.Shine on the web

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Nicotine exposure in the womb gives baby rats addictive personalities

Nicotine exposure in the womb gives baby rats addictive personalities | Amazing Science |
Results suggest explanation for why people exposed to nicotine in the womb are more likely to become smokers. 


Exposure to nicotine in the womb increases the production of brain cells that stimulate appetite, leading to overconsumption of nicotine, alcohol and fatty foods in later life, according to a new study in rats.


Smoking during pregnancy is known to alter fetal brain development and increase the risk of premature birth, low birth weight and miscarriage. Prenatal exposure to nicotine also increases the likelihood of tobacco use and nicotine addiction in later life, but exactly how is unclear. To understand the mechanisms behind this effect, Sarah Leibowitz, a behavioural neurobiologist at the Rockefeller University in New York, and her colleagues injected pregnant rats with small doses of nicotine — which the researchers say are comparable to the amount a pregnant woman would get from smoking one cigarette a day — and then examined the brains and behaviour of the offspring. 


In a paper published recently in the Journal of Neuroscience, they found that nicotine increased the production of specific types of neurons in the amygdala and hypothalamus. These cells produce orexin, enkephalin and melanin-concentrating hormone, neuropeptides that stimulate appetite and increase food intake.


Rats exposed to nicotine in the womb had more of these cells and produced more of the neuropeptides than those that were not, and this had long-term consequences on their behaviour. As adolescents, they not only self-administered more nicotine, but also ate more fat-rich food and drank more alcohol.


“These peptide systems stimulate food intake,” says Leibowitz, “but we found that they similarly increase the consumption of drugs and stimulate the brain’s reward mechanisms that promote addiction and substance abuse.”

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New drug mimics the beneficial effects of exercise -- at least in mice

New drug mimics the beneficial effects of exercise -- at least in mice | Amazing Science |

A drug known as SR9009, which is currently under development at The Scripps Research Institute (TSRI), increases the level of metabolic activity in skeletal muscles of mice. Treated mice become lean, develop larger muscles and can run much longer distances simply by taking SR9009, which mimics the effects of aerobic exercise. If similar effects can be obtained in people, the reversal of obesity, metabolic syndrome, and perhaps Type-II diabetes might be the very welcome result.


The drug was developed by Professor Thomas Burris of TSRI, who found that it was able to reduce obesity in populations of mice. It binds to and activates a protein called Rev-ErbAα, which influences fat and sugar burning in the liver, production of fat cells, and the body's inflammatory response.


Previous studies on mice lacking Rev-ErbAα showed decreased skeletal muscles, metabolic rate, and running capacity. Such mice appeared fated by their genetics to live as couch potatoes.


When Burris' group administered SR9009 to these mice to activate the Rev-Erbα protein, the results were remarkable. The metabolic rate in the skeletal muscles of the mice increased significantly. The treated mice were not allowed to exercise, but despite this they developed the ability to run about 50 percent further before being stopped by exhaustion.


“The animals actually get muscles like an athlete who has been training,” said Burris. “The pattern of gene expression after treatment with SR9009 is that of an oxidative-type muscle – again, just like an athlete.”


Burris noted that the beneficial effects of SR9009 on mice could carry over to people with metabolic syndrome or other conditions that reduce their ability to exercise.

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Tools for crushing diatoms – opal teeth in copepods feature a rubber-like bearing composed of resilin

Tools for crushing diatoms – opal teeth in copepods feature a rubber-like bearing composed of resilin | Amazing Science |

Copepods dominate the zooplankton in nearly all areas of the World Ocean and thus play a significant role in the pelagic food web. Many copepod species feed mainly on phytoplankton and are important links between the primary producers and organisms of higher trophic levels. Accordingly, the knowledge of the impact of copepod grazing on phytoplankton stocks is essential for the understanding of particle and energy fluxes in the ocean.

Diatoms are generally known for superior mechanical properties of their mineralised shells. Nevertheless, many copepod crustaceans are able to crush such shells using their mandibles. This ability very likely requires feeding tools with specific material compositions and properties. For mandibles of several copepod species silica-containing parts called opal teeth have been described. The present study reveals the existence of complex composite structures, which contain, in addition to silica, the soft and elastic protein resilin and form opal teeth with a rubber-like bearing in the mandibles of the copepod Centropages hamatus. These composite structures likely increase the efficiency of the opal teeth while simultaneously reducing the risk of mechanical damage. They are supposed to have coevolved with the diatom shells in the evolutionary arms race, and their development might have been the basis for the dominance of the copepods within today's marine zooplankton.

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Black Holes and Gravitational Waves: Movies of Extreme Spacetimes

Black Holes and Gravitational Waves: Movies of Extreme Spacetimes | Amazing Science |

A beginner's guide to black holes, warped spacetime, gravitational waves, and other bizarre ideas from astrophysics: From Galileo's first telescope to today's most sensitive neutrino telescopes, astronomers have been developing new eyes with which to see the night sky, allowing them to discover new worlds while better understanding our own. Now, for the first time, astronomers are creating new earswith which to hear the Universe around us.

The sounds we hear in our ears are carried through the air around us. Anything giving off sound gives the air more pressure, then less pressure. These changes in pressure travel as waves, until they reach our ears and push on our eardrums. The waves don't move our heads very much, but they move our eardrums, which allows the delicate mechanisms in our ears to pick up these movements relative to our heads.

Since sound needs air (or some other matter) to compress, sound can't travel through empty space. Gravitational waves, on the other hand, don't need air to travel; they just need spacetime. They travel across the Universe from its deepest reaches, never stopping or slowing down—regardless of the presence or absence of air. Nonetheless, they have a similar effect on our ears. As a gravitational wave passes through your head, the positions of your eardrums change relative to the position of your head. Again, the delicate mechanisms in your ears would pick up these movements, and your brain would turn them into sounds. But why aren't we kept up at night with the noise from black holes everywhere falling into each other?

It turns out that, by the time gravitational waves from these distant sources reach us, they are incredibly quiet. The smallest sound that a human with good ears can hear is roughly the sound of a mosquito buzzing 10 feet away. Gravitational waves reaching the Earth are typically another three trillion times quieter than this. To put it another way, consider the sound of an atomic blast 20 feet away. That sound (though you wouldn't be around to hear it if you were there) is as much louder than the mosquito as gravitational waves are quieter.

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C. elegans Can Pass a Trait Down for 100 Generations…Without DNA !

C. elegans Can Pass a Trait Down for 100 Generations…Without DNA ! | Amazing Science |

C. elegans worms whose grandparents had the ability to fight viruses using a fleet of tiny RNA molecules retain these molecules even when they don’t have the genes for them. They can pass these molecules down for more than a hundred generations.


A research team engineered worms that didn’t have the genes to make the RNAs—which work by inhibiting the virus replication machinery—and then bred them with worms that did for several generations. They ended up with some worms whose ancestors had had the virus-fighting molecules, but did not themselves possess the necessary genes. The team then watched these worms under the microscope and saw that they still attacked viruses in exactly the same way as their grandparents.


Numerous control experiments confirmed that the effect was real, and only happened in worms who had ancestors with the genes. The researchers collected all the various RNA molecules in these worms and saw that indeed, they possessed the virus-fighting variety.After about three generations, the effect seemed to wear off; most worms without the genes stopped being able to attack viruses. But for some worms, it never stopped. The team bred those worms for more than one hundred generations, nearly a year, and the creatures never flagged in their ability to defend themselves.


How is this possible? The team keeps mum on any ideas of how this inheritance works. But they do uncover some tantalizing details that give us room for speculation. One possibility is that the RNA molecules made by the original worms in response to a virus attack were floating around in the cytoplasm of the eggs and sperm that became their offspring. If that’s the case, then the offspring are basically using their parents’ leftovers, with each generation having a bit less of the original stuff.


The researchers mention this possibility of the original RNA being “diluted” with each generation, but don’t, as far as we can tell, try to test that.But what about the worms that hang on to the RNA indefinitely? The researchers found that for that to happen, a particular enzyme that builds RNAs has to be present. Maybe, then, these worms manage to jerry-rig a way to make copies of the virus-fighting RNA with that enzyme (which isn’t part of the usual machinery), even though they lack the gear required to make it in the normal fashion. The gene for that enzyme would then be passed on as normal.

Via Sakis Koukouvis
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International team analyzed 7,042 tumors and identified 21 distinct genetic signatures in half of all cancers

International team analyzed 7,042 tumors and identified 21 distinct genetic signatures in half of all cancers | Amazing Science |

An international team, including scientists from Sydney’s Garvan Institute of Medical Research and The University of Queensland, has described the mutational processes that drive tumor development in 30 of the most common cancer types. The discovery, published overnight in Nature, could help to treat and prevent a wide range of cancers.

The team analysed 7,042 tumours and identified 21 distinct mutational signatures and the cancer types in which they occur. Professor Sean Grimmond, from UQ’s Institute for Molecular Bioscience, said that different mutation-causing processes left different genetic ‘signatures’ in cancer cells.

“All cancers are caused by genetic mutations, and in some cases we know the processes driving them, for example, tobacco smoking in lung cancer, however, our understanding of the causes of mutation in most cancers is remarkably limited,” Professor Grimmond said. 

“This study allows us to pinpoint the root genetic cause of tumour development in common cancers and, in some cases, to identify the biological process that damages the DNA and gives rise to the cancer.”

“For example, we found that a family of enzymes known as APOBECs, which can be activated in response to viruses, is linked to mutations in more than half of the 30 cancer types.” 

All of the cancers contained two or more signatures, reflecting the variety of processes that contribute to cancer development. Professor Andrew Biankin from the Garvan Institute and the University of Glasgow said some of the mutational signatures are found in multiple cancer types, while others are confined to a single cancer type.

“Twenty-five of the 30 cancers we examined had signatures that arose from mutational processes related to ageing,” Professor Biankin said. “Childhood cancers showed the fewest mutations whereas cancers that were caused by exposure to known carcinogenics such as tobacco and UV light had the highest prevalence of mutations.

“It is likely we will be able to identify more mutational signatures as more cancers are sequenced and the analysis of these data is further refined.”

The study was led by Ludmil Alexandrov and Professor Sir Mike Stratton from the Wellcome Trust Sanger Institute in London. “We have identified the majority of the mutational signatures that explain the genetic development and history of cancers in patients,” said Ludmil Alexandrov, first author from the Wellcome Trust Sanger Institute. “We are now beginning to understand the complicated biological processes that occur over time and leave these residual mutational signatures on cancer genomes.”

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If bird babies want to be fed they need a password

If bird babies want to be fed they need a password | Amazing Science |

It's always a good idea to listen to your mother, but that goes double for baby fairy-wrens even before they are hatched. If those fairy-wren babies want to be fed, they need to have a password -- a single unique note -- taught to them by their mothers from outside the egg. The nestlings incorporate that password right into their begging calls, according to researchers who published their discovery in Current Biology in November 2012.


This remarkable example of prenatal learning is an adaptation that apparently allows fairy-wren parents to discriminate between their own babies and those of parasitic cuckoos who have invaded their nests. Females also teach their mate and any helpers the password by singing it to them in a "solicitation song" performed away from the nest.


"Parents and others attending the nestlings will only feed them if their begging calls contain the learned password," said Sonia Kleindorfer of Flinders University in Australia. Otherwise, the parents simply abandon the nest and start again.


Kleindorfer and her colleagues originally stumbled onto this scheme when they noticed something unexpectedly odd while studying nest predators and alarm calls: superb fairy-wren mothers calling to their unhatched eggs. The researchers later found that fairy-wren nestlings' one-note begging calls differed from one nest to another. The researchers' key breakthrough was the realization that the unique element in each female's incubation call was the basis of the begging call of her brood. In other words, it was a password.


Cross-fostering experiments, in which clutches of eggs were swapped between nests, showed that the nestlings produced begging calls that matched their foster mothers, not their biological mothers, evidence that the passwords were indeed learned. The researchers found they could also prevent attending parents from feeding their nestlings by placing a loudspeaker under the nest that played the wrong begging call.


The findings show that even traits that appear innate may actually be learned. Such an ability could have real evolutionary implications for the superb fairy-wrens, and more broadly.


"We show that females that guard and teach the embryo could increase the transmission efficacy of female cultural traits," Kleindorfer explained. "In systems with uniparental care, caretakers of embryos will have more opportunity to pass on female memes, or 'messages,' to the embryo." And, she added, that means that mothers have a special ability to transmit not just genes to the next generation, but also memes.

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Rotational Doppler shift spotted in twisted light

Rotational Doppler shift spotted in twisted light | Amazing Science |

Unexpected discovery could help astronomers study spinning stars. "Twisted light" has been used by researchers in the UK to develop a new way of measuring the angular velocity of a remote spinning object. The team fired two beams of light carrying orbital angular momentum at a rotating surface and showed that the resulting interference pattern in the reflected light is related to the surface's angular velocity. The researchers hope that the phenomenon can be used to develop systems to carry out a range of practical measurements, from monitoring industrial equipment to calculating rotation rates of astronomical objects.


The Doppler shift – a shift in the frequency of waves emitted or reflected by an object moving relative to the observer – is a well-understood phenomenon with numerous uses in science and engineering. These include determining the speed at which distant galaxies are approaching or receding and making it easier for the police to catch speeding motorists. It can also be used to study objects that are rotating when some of the object is rotating towards the observer and some is rotating away. However, it cannot be used to work out how fast an object is rotating about the axis pointing along the direct line of sight between the object, light source and observer.This latest work was done using beams of light that carry orbital angular momentum. This involves the wavefronts of the light's electric and magnetic fields rotating around the direction of the propagation vector. The fields trace out fusilli-like spirals and the faster the rotation, the greater the orbital angular momentum. This twisted light is of great interest to those working in the telecommunications industry and researchers have already shown that orbital angular momentum can be used to boost the amount of information that can be transmitted using light and other electromagnetic radiation.


The study was done by Martin Lavery and colleagues at the University of Glasgow, together with researchers at the University of Strathclyde. The team's rotating surface is simple – a piece of aluminium foil stuck to a wheel that is spun by a motor taken from a remote-controlled car. The back of the foil (the matt side) is illuminated by two superposed light beams of the same frequency and intensity but with equal and opposite angular momenta.

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Typhoid Mary Mystery May Finally Have Been Solved

Typhoid Mary Mystery May Finally Have Been Solved | Amazing Science |
How exactly was the Irish immigrant known as Typhoid Mary able to infect about 50 people in New York City in the early 1900s without succumbing to the illness herself? Scientists say they are now close to cracking the case.


In a new study, they were able to solve the mystery of how a dangerous bacterial pathogen can, in some people, manage to persist without causing symptoms and find a way to survive for decades.


For the salmonella bacteria that causes typhoid fever, the researchers said it manages to hide in immune cells known as macrophages and "hacks" their metabolism to their own benefit. If the germs are successful in pulling that off, then an infected person can unknowingly spread the pathogen without falling ill themselves -- like in Typhoid Mary, whose real name was Mary Mallon. Just watch the video above.


“To all outward appearances, she was perfectly healthy,” study co-author Dr. Denise Monack, associate professor of immunology and microbiology at Stanford University, said in a written statement.


Monack and her research team infected mice with a strain of salmonella, and found that, the bacteria were able to "wait out" the body's aggressive immune response before they then positioned themselves in the immune cells that became less aggressive at later stages of infection.


“There aren’t a ton of pathogens that hang out in macrophages,” Monack told the Los Angeles Times, adding that the bacterium behind tuberculosis is another.


So if that's where the nasty germ hangs out, how does it survive and go unnoticed? The researchers found that a protein known as PPAR-delta was required for salmonella to replicate inside the macrophages and "hack" them.


“Salmonella is doing something to activate PPAR-delta,” Monack said in the statement. “We suspect it’s releasing some as-yet-unknown PPAR-delta-stimulating virulence factor into the macrophages it infects. If we can figure out what that is, it could lead to some great anti-salmonella therapeutics with relatively fewer side effects.”

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WIRED: Spray-on smart glass filters light and heat on demand

WIRED: Spray-on smart glass filters light and heat on demand | Amazing Science |

Material scientists have published a study describing how they engineered a spray-on nanocrystal coating that that can control how much light or heat passes through it using electricity.


The team, from the US Department of Energy's Lawrence Berkeley National Laboratory, has already struck up a partnership with Californian smart window startup Heliotrope to bring the material to market. Heliotrope in fact came out of the Molecular Foundry, where coauthor on the nanocrystal study Delia Milliron works as deputy director. Milliron and her ream were awarded a $3 million (£1.9 million) research grant by the Energy Department's Advanced Research Projects Agency-Energy last year, and had already achieved great success with the development of a coating that blocks heat-delivering near-infrared (NIR) light, but not visible light. Now, she and her research team have used a similar technique -- which relies on an electric current to switch its function on and off -- combining two totally different compounds to block either light or heat selectively.


One of the materials, indium tin oxide (ITO) -- a component in LCD and touchscreens -- is extremely conductive. When electricity passes through it, it allows the material to absorb heat energy from NIR. ITO nanocrystals were embedded in glass made from niobium oxide. The niobium ions in it are used in superconductive materials, and when combined with certain compounds can detect infrared light. Both ITO and niobium oxide are electrochromic, which means they change colour when a current is passed through them -- niobium oxide will darken when exposed to a current, for instance. Electrochromic materials are used for tinting the windows of some cars, and in this case would filter the amount of heat and light coming through the windows. 

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Hive Plots - Linear Layout for Network Visualization - Visually Interpreting Network Structure and Content Made Possible

Hive Plots - Linear Layout for Network Visualization - Visually Interpreting Network Structure and Content Made Possible | Amazing Science |

Networks are typically visualized with force-based or spectral layouts. These algorithms lack reproducibility and perceptual uniformity because they do not use a node coordinate system. The layouts can be difficult to interpret and are unsuitable for assessing differences in networks.


To address these issues, we introduce hive plots ( ) for generating informative, quantitative and comparable network layouts. Hive plots depict network structure transparently, are simple to understand and can be easily tuned to identify patterns of interest. The method is computationally straightforward, scales well and is amenable to a plugin for existing tools.

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A New Form of Carbon is Stronger Than Graphene and Diamond

A New Form of Carbon is Stronger Than Graphene and Diamond | Amazing Science |

The sixth element, carbon, has given us an amazing abundance of extraordinary materials. Once there was simply carbon, graphite and diamond. But in recent years chemists have added buckyballs, nanotubes and any number of exotic shapes created out of graphene, the molecular equivalent of chickenwire.


So it’s hard to believe that carbon has any more surprises up its sleeve. And yet today, Mingjie Liu and pals at Rice University in Houston calculate the properties of another form of carbon that is stronger, stiffer and more exotic than anything chemists have seen before.


The new material is called carbyne. It is a chain of carbon atoms that are linked either by alternate triple and single bonds or by consecutive double bonds.


Carbyne is something of a mystery. Astronomers believe they have detected its signature in interstellar space but chemists have been bickering for decades over whether they had ever created this stuff on Earth. A couple of years ago, however, they synthesised carbyne chains up to 44 atoms long in solution.


The thinking until now has been that carbyne must be extremely unstable. In fact some chemists have calculates that two strands of carbyne coming into contact would react explosively.


Nevertheless, nanotechnologists have been fascinated with potential of this material because it ought to be both strong and stiff and therefore useful. But exactly how strong and how stiff, no one has been quite sure.

This is where Liu and co step in. These guys have calculated from first principles the bulk properties of carbyne and the results make for interesting reading.  


For a start, they say that carbyne is about twice as stiff as the stiffest known materials today. Carbon nanotubes and grapheme, for example, have a stiffness of 4.5 x 10^8 N.m/kg but carbyne tops them with a stiffness of around 10^9 N.m/kg. 


Just as impressive is the new material’s strength. Liu and co calculate that it takes around 10 nanoNewtons to break a single strand of carbyne. “This force translates into a specific strength of 6.0–7.5×10^7 N∙m/kg, again significantly outperforming every known material including graphene (4.7–5.5×10^7 N∙m/ kg), carbon nanotubes (4.3–5.0×10^7 N∙m/ kg), and diamond (2.5–6.5×10”7 N∙m/kg4),” they say.


Carbyne has other interesting properties too. Its flexibility is somewhere between that of a typical polymer and double-stranded DNA. And when twisted, it can either rotate freely or become torsionally stiff depending on the chemical group attached to its end.


Perhaps most interesting is the Rice team’s calculation of carbyne’s stability.  They agree that two chains in contact can react but there is an activation barrier that prevents this happening readily. “This barrier suggests the viability of carbyne in condensed phase at room temperature on the order of days,” they conclude.


All this should whet the appetite of nanotechnologists hoping to design ever more exotic nanomachines, such as nanoelectronic and spintronic devices.  Given the advances being made in manufacturing this stuff, we may not have long to wait before somebody begins exploiting the extraordinary mechanical properties of carbyne chains for real.

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