A custom-built programmable 3D printer can create materials with several of the properties of living tissues, Oxford University scientists have demonstrated.

The new type of material consists of thousands of connected water droplets, encapsulated within lipid films, which can perform some of the functions of the cells inside our bodies.

These printed 'droplet networks' could be the building blocks of a new kind of technology for delivering drugs to places where they are needed and potentially one day replacing or interfacing with damaged human tissues. Because droplet networks are entirely synthetic, have no genome and do not replicate, they avoid some of the problems associated with other approaches to creating artificial tissues -- such as those that use stem cells.

The team report their findings in this week's Science.

'We aren't trying to make materials that faithfully resemble tissues but rather structures that can carry out the functions of tissues,' said Professor Hagan Bayley of Oxford University's Department of Chemistry, who led the research. 'We've shown that it is possible to create networks of tens of thousands connected droplets. The droplets can be printed with protein pores to form pathways through the network that mimic nerves and are able to transmit electrical signals from one side of a network to the other.'

Each droplet is an aqueous compartment about 50 microns in diameter. Although this is around five times larger than living cells the researchers believe there is no reason why they could not be made smaller. The networks remain stable for weeks.

'Conventional 3D printers aren't up to the job of creating these droplet networks, so we custom built one in our Oxford lab to do it,' said Professor Bayley. 'At the moment we've created networks of up to 35,000 droplets but the size of network we can make is really only limited by time and money. For our experiments we used two different types of droplet, but there's no reason why you couldn't use 50 or more different kinds.'

The unique 3D printer was built by Gabriel Villar, a DPhil student in Professor Bayley's group and the lead author of the paper.

The droplet networks can be designed to fold themselves into different shapes after printing -- so, for example, a flat shape that resembles the petals of a flower is 'programmed' to fold itself into a hollow ball, which cannot be obtained by direct printing. The folding, which resembles muscle movement, is powered by osmolarity differences that generate water transfer between droplets.

Gabriel Villar of Oxford University's Department of Chemistry said: 'We have created a scalable way of producing a new type of soft material. The printed structures could in principle employ much of the biological machinery that enables the sophisticated behaviour of living cells and tissues.'

source: The above story is reprinted from materials provided byUniversity of Oxford.and science daily

A growing online library of bird sounds, photos and information offers a new resource for backyard birders and seasoned ornithologists alike.

The Avian Vocalizations Center at Michigan State University, or AVoCet,offers free downloads of bird sounds from around the world. It also features sonograms that visually chart the sounds, photos of birds recorded, Google Earth maps of recording locations and links to other online sound collections.

More than 10,200 recordings from over 3,190 species in 45 countries are now available on AVoCet, "and that's growing quickly," said Pamela Rasmussen, an assistant professor of zoology and assistant curator at the MSU Museum. "Soon recordings and their data from many more species and areas will be available for download from AVoCet."

There are, after all, 10,000 bird species, all of which make sounds of some type. Many birds, such as cardinals, even sing in regional dialects. Some birds have huge vocabularies -- a single male Brown Thrasher is known to give 2,000 different notes.

Author of an exhaustive reference work on the birds of South Asia, Rasmussen has personally recorded on all the continents for this project. Her work in the Philippines alone netted 597 recordings of 120 species, many of which are threatened. Some of those sound types are not publicly available anywhere other than AVoCet.

AVoCet also contains recordings made around the world so far by 65 others, including local ornithologists, professional guides and MSU students from Rasmussen's study abroad and ornithology courses. Zoology department programmer/analyst Patrick Bills built the database and Web site and undergraduate students also contributed.

Digital technology has revolutionized birding, Rasmussen explains, allowing enthusiasts and professionals to more easily record, share and play bird calls. Online access to the AVoCet library allows easy access to sounds, photos and other supporting information via computer and Internet-connected mobile devices.

The ability to identify birds vocally is crucial for monitoring bird movements and populations, including such popular events as the annual Christmas bird counts organized across the country. A comprehensive collection of bird sounds can yield better understanding of habitats, ranges and habits, while allowing more efficient and thorough biodiversity studies, Rasmussen said. "It's very difficult to see birds in a tropical rainforest, but not difficult to hear and recognize them."

Oriented to the scientific community, AVoCet maintains rigorous scholarly standards. Whenever possible, recordings are accompanied by photos and sighting observations that enable independent evaluation, Rasmussen said. Scientists can then accurately map avian biodiversity and perhaps identify new species.

"We know that certain species will go extinct in the near future and, sadly, there's not a lot that can realistically be done about it," Rasmussen said. "However, ornithologists and birders do now have the opportunity to document virtually all the species of birds out there in one way or another, and one major goal of AVoCet is to contribute to this effort."

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The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by Michigan State University.

A new laser-beam steering system that aims and focuses bursts of light onto single atoms for use in quantum computers has been demonstrated by collaborating researchers from Duke University and the University of Wisconsin-Madison.

Described in the journal Applied Physics Letters, published by the American Institute of Physics, the new system is somewhat like the laser-light-show projectors used at rock concerts and planetariums. But it's much smaller, faster, atom-scale accurate and aimed at the future of computing, not entertainment.

In theory, quantum computers will be able to solve very complex and important problems if their basic elements, 

called qubits, remain in a special "quantum entangled" state for a long enough time for the calculations to be carried out before information is lost to natural fluctuations. One of several promising approaches to quantum computing uses arrays of individual atoms suspended by electromagnetic forces. Pulses of laser light manipulate the internal states of the atoms that represent the qubits, to carry out the calculation. However the lasers must also be focused and aimed so accurately that light meant for one atom doesn't affect its neighbors.

The new system did just that. Tiny micromirrors, each only twice the diameter of a human hair, pointed to each target atom in as little as 5 microseconds, which is about 1,000 times faster than sophisticated beam-steering mirrors developed for optical communications switching, not to mention the still slower units used in light shows. The researchers saw that the laser pulses also correctly manipulated the quantum properties of each target atom -- in this case a line of five rubidium-87 atoms -- without disturbing any neighboring atoms, which were separated by just 8.7 microns, about one-tenth the diameter of a human hair.

"Our experiments demonstrated the crucial requirement that our micromirror system maintain the laser-beam quality necessary to manipulate the internal states of the individual atoms," said Jungsang Kim, leader of the Duke researchers who designed the micromirror system. The atomic physics experiments were performed in Mark Saffman's group at University of Wisconsin-Madison.

The groups plan to continue their collaboration, with future experiments targeting two-qubit gates, which are expected to be the basic building block of quantum logic, and atoms confined in larger two-dimensional arrays.

This work was funded by the Army Research Office, the Intelligence Advanced Research Projects Activity (IARPA), and the National Science Foundation.

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The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by American Institute of Physics, via EurekAlert!, a service of AAAS.

The Large Binocular Telescope Interferometer has taken its first images of the star Beta Peg in the constellation Pictor -- an encouraging start for an instrument designed to probe the cosmic neighborhoods where Earth-like planets could exist.

Eight years in development, the NASA-funded instrument combines beams of light from twin 8.4-meter (28-foot) mirrors mounted atop the Large Binocular Telescope on Mount Graham, Ariz. "By combining the light of the telescopes, we're able to realize its full potential," said Project Manager Tom McMahon of the University of Arizona, Tucson. "Together, the two mirrors form the largest single-mount telescope in the world."

"The quality of the first-light images is wonderful," said the principal investigator for the project, Phil Hinz of the University of Arizona. "The telescope was stable and the instrument was working properly."

With this high-resolution imaging capability, astronomers hope to probe nearby solar systems -- specifically, the areas in these systems where Earth-like planets with liquid water could exist. Though the Large Binocular Telescope Interferometer won't be able to detect Earth-size planets, it will be able to see dust disks that are indicative of planet formation, in addition to detecting large, Jupiter-size planets farther out from the star. These findings will help future, space-based exoplanet missions know where to search for Earth-like planets in our own galactic neighborhood.

With its ability to probe this "habitable zone" of other solar systems, the Large Binocular Telescope Interferometer will also complement the capabilities of other NASA missions -- the Keck Interferometer, which can find dust very close to stars; and the Spitzer Space Telescope, which is adept at observing planet-forming dust that is much more distant.

"This instrument will help complete our picture of what planetary systems look like and be a pathfinder for finding Earth-like planets that are close by," Hinz said.

With a major upgrade of the Large Binocular Telescope's adaptive optics system scheduled for next year, the interferometer will undergo testing and commissioning for the majority of 2011, and during that time, scientific observations will begin.

"This is the highest-resolution instrument of its kind in the world," McMahon said. "We won't just be able to image exoplanets, but extragalactic objects, nebulae and galaxies. It's taken time to make sure it works as envisioned, but now it's time to do science."

The Large Binocular Telescope Interferometer is funded by NASA and managed by Ben Parvin at NASA's Jet Propulsion Laboratory, Pasadena, Calif., as part of NASA's Exoplanet Exploration Program. The instrument and product development are provided by the University of Arizona, Tucson.

More information about the Large Binocular Telescope Interferometer can be found at: http://lbti.as.arizona.edu/LBTI-Main/Project.html

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The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by NASA/Jet Propulsion Laboratory. The original article was written by Josh Rodgriguez

The globular cluster Messier 107, also known as NGC 6171, is a compact and ancient family of stars that lies about 21 000 light-years away. Messier 107 is a bustling metropolis: thousands of stars in globular clusters like this one are concentrated into a space that is only about twenty times the distance between our Sun and its nearest stellar neighbour, Alpha Centauri, across. A significant number of these stars have already evolved into red giants, one of the last stages of a star's life, and have a yellowish colour in this image.

Globular clusters are among the oldest objects in the Universe. And since the stars within a globular cluster formed from the same cloud of interstellar matter at roughly the same time -- typically over 10 billion years ago -- they are all low-mass stars, as lightweights burn their hydrogen fuel supply much more slowly than stellar 

behemoths. Globular clusters formed during the earliest stages in the formation of their host galaxies and therefore studying these objects can give significant insights into how galaxies, and their component stars, evolve.

Messier 107 has undergone intensive observations, being one of the 160 stellar fields that was selected for the Pre-FLAMES Survey -- a preliminary survey conducted between 1999 and 2002 using the 2.2-metre telescope at ESO's La Silla Observatory in Chile, to find suitable stars for follow-up observations with the VLT's spectroscopic instrument FLAMES [1]. Using FLAMES, it is possible to observe up to 130 targets at the same time, making it particularly well suited to the spectroscopic study of densely populated stellar fields, such as globular clusters.

M107 is not visible to the naked eye, but, with an apparent magnitude of about eight, it can easily be observed from a dark site with binoculars or a small telescope. The globular cluster is about 13 arcminutes across, which corresponds to about 80 light-years at its distance, and it is found in the constellation of Ophiuchus, north of the pincers of Scorpius. Roughly half of the Milky Way's known globular clusters are actually found in the constellations of Sagittarius, Scorpius and Ophiuchus, in the general direction of the centre of the Milky Way. This is because they are all in elongated orbits around the central region and are on average most likely to be seen in this direction.

Messier 107 was discovered by Pierre Méchain in April 1782 and it was added to the list of seven Additional Messier Objects that were originally not included in the final version of Messier's catalogue, which was published the previous year. On 12 May 1793, it was independently rediscovered by William Herschel, who was able to resolve this globular cluster into stars for the first time. But it was not until 1947 that this globular cluster finally took its place in Messier's catalogue as M107, making it the most recent star cluster to be added to this famous list.

This image is composed from exposures taken through the blue, green and near-infrared filters by the Wide Field Camera (WFI) on the MPG/ESO 2.2-metre telescope at the La Silla Observatory in Chile.

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The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by ESO.

Astronomers have traced the waxing and waning light of exploding stars more closely than ever before and seen patterns that aren't yet accounted for in our current understanding of how these eruptions occur.

Using data from a sensitive instrument aboard a satellite that images the entire sky every 102 minutes, they studied four of these stars, or novae, that exploded so violently their light would have been visible without a telescope and measured their brightness over the course of the outburst.

Three of the novae stalled before reaching a peak, and all flickered or flared as the explosions ran their course, 

they report in The Astrophysical Journal.

The instrument they used -- the Solar Mass Ejection Imager -- was developed by a team led by astrophysicist Bernard Jackson at the Center for Astrophysics and Space Sciences at the University of California, San Diego, to study the sun. Rebekah Hounsell, a graduate student at Liverpool John Moores University in Britain made the measurements while visiting UC San Diego.

Because starlight is a distraction for Jackson's team, noise they must subtract from their data so that they can focus on the sun's outer corona and the heliosphere, they make detailed maps of stellar light, including its brightness.

In those maps Hounsell identified the four novae by finding points of light that rapidly brightened and dimmed over the course of days.

Wavering Light

Other astronomers had observed a pause in the brightening of novae, or "pre-maximum halt" before, but some thought it an anomaly. The precise time-scale and repeated observations of the current study confirms it, they authors say.

"The reality of this halt as found in all three of the fast-declining novae observed is a challenge to detailed models of the nova outburst," said one of the authors, astrophysicist Mike Bode, of Liverpool John Moores University.

Two independent teams of theorists have already begun to refine their models of how novae explode in response.

Astronomers typically characterize novae's changing light with curves smoothly fit to more sporadic observations, but the rapid cadence of the solar imager captured glimmers that hadn't been observed before. All flickered as their light dimmed and one nova, the slowest of the four to dim, flared brightly twice after reaching its peak luminosity.

These novae are white dwarf stars that steal matter, in the form of hydrogen, from a companion star, often an aging, expanding red giant. As hydrogen accumulates the white dwarf's gravity pulls it in and condenses it until it ignites, setting off a runaway nuclear fusion reaction.

The team speculates that the post-peak flares may correspond to changes in the dynamics of that reaction that still need to be explained.

Catching Missing Stars

"Before Hounsell looked through these data, most novae were observed only after their peak luminance. The instrument's very even cadences and uniformly exposed images allow us to trace the entire evolution of these explosions as they brighten and dim," UC San Diego's Jackson said.

Data from the imager, which has been in operation aboard the Coriolis satellite since January 2003, allows astronomers to measure novae that they initially missed.

"Even today novae are mainly discovered by amateur astronomers around the world who then alert their professional counterparts to conduct observations," Hounsell said.

As many as five novae bright enough to be detected by SMEI explode in our galaxy each year, Allen Shafter, astronomy professor at San Diego State University and one of the co-authors of the report have previously estimated, but more than half have gone undetected.

"The instrument assures that the brightest and most rapidly evolving novae -- ones that brighten and then fade within a few days -- are not overlooked," Shafter said. "The high time resolution of these observations has opened up a new window into the study of novae in our galaxy."

Bernard Jackson's research at UC San Diego is supported by the National Science Foundation and NASA. Allen Shafter's work at San Diego State University is supported by the National Science Foundation.

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The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided by University of California - San Diego. The original article was written by Susan Brown.

Researchers at Umeå Plant Science Center in Sweden discovered, in collaboration with the Syngenta company, a previously unknown gene in sugar beets that blocks flowering. Only with the cold of winter is the gene shut off, allowing the sugar beet to blossom in its second year. The discovery of this new gene function makes it possible to control when sugar beets bloom.

The new findings were recently published in the journal Science.

Scientists at Umeå Plant Science Center and the international company Syngenta, in a joint study of genetic regulation in the sugar beet, have discovered an entirely new principle for how flowering can be controlled. The 

study, which was co-directed by Professorn Ove Nilsson, of the Swedish University of Agricultural Sciences 

(SLU), and Syngenta scientist Dr. Thomas Kraft, showed that there is a gene in the sugar beet that was previously unknown.

"When we studied a gene in the sugar beet that usually stimulates blooming in other plants, we made a very surprising discovery: in the sugar beet evolution has developed a 'sister gene' that has taken on the exact opposite function, namely, to inhibit blossoming. For biennial sugar beets this means that they can't flower in their first year. Once the plants have been exposed to the cold of winter at the end of the first year, the 'gene blockade is lifted,' and the sugar beets can bloom in their second year of life," says Ove Nilsson about the function of the newly discovered flowering gene.

The researchers speculate that the development of the inhibiting sister gene was an important factor in enabling biennial sugar beets to evolve from an annual to a biennial plant. Furthermore, plant researchers in Umeå and Landskrona have shown that it is possible to manipulate the "flowering gene" in such a way as to leave the gene constantly "turned on," that is, to block blooming, and thereby prevent it from being turned off after winter.

"In that way it's possible to fully control the flowering time of the sugar beet. This enables us to develop a so-called 'winter beet,' that is, a sugar beet that can be planted in the autumn and then will continue to grow throughout the following growth season without blossoming," says Thomas Kraft at Syngenta Seeds.

"A winter beet has be a high priority for sugar beet growers, since it is estimated to be able to increase the yield by about 25 percent and at the same time allow a more extended harvesting period. Traditional breeding has failed to produce such a plant. Syngenta Seeds is now going to move on to more in-depth tests of this potential new winter beet."

The research work in this project has been primarily conducted by an industrial doctoral candidate, Pierre Pin, with funding from the Swedish Research Council and Syngenta Seeds AB.

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The above story is reprinted (with editorial adaptations by ScienceDaily staff) from materials provided byExpertanswer, via AlphaGalileo.