Protein-Making Machinery in Bacteria Successfully Re-Engineered

Artist's rendering of E. coli bacteria. (Credit: iStockphoto/Sebastian Kaulitzki)

Science Daily  — Yale University researchers have successfully re-engineered the protein-making machinery in bacteria, a technicaltour de force that promises to revolutionize the study and treatment of a variety of diseases.

Since the structure of DNA was revealed in the 1950s, scientists have been working hard to understand the nature of the genetic code. Decades of research and recent advances in the field of synthetic biology have given researchers the tools to modify the natural genetic code within organisms and even rewrite the universal recipe for life."Essentially, we have expanded the genetic code of E. coli, which allows us synthesize special forms of proteins that can mimic natural or disease states," said Jesse Rinehart of the Department of Cellular and Molecular Physiology and co-corresponding author of the research published in the Aug. 26 issue of the journal Science."What we have done is taken synthetic biology and turned it around to give us real biology that has been synthesized," Rinehart explained.The Yale team -- under the direction of Dieter Söll, Sterling Professor of Molecular Biophysics and Biochemistry, professor of chemistry and corresponding author of the paper -- developed a new way to influence the behavior of proteins, which carry out almost all of life's functions. Instead of creating something new in nature, the researchers essentially induced phosphorylation, a fundamental process that occurs in all forms of life and can dramatically change a protein's function. The rules for protein phosphorylation are not directly coded in the DNA but instead occur after the protein is made. The Yale researchers fundamentally rewrote these rules by expanding the E. coli genetic code to include phosphoserine, and for the first time directed protein phosphorylation via DNA.

This new technology now enables the production of human proteins with their naturally occurring phosphorylation sites, a state crucial to understanding disease processes. Previously, scientists lacked the ability to study proteins in their phosphorylated or active state. This has hindered research in diseases such as cancer, which is marked by damagingly high levels of protein activation.

"What we are doing is playing with biological switches -- turning proteins on or off -- which will give us a completely new way to study disease states and hopefully guide the discovery of new drugs," Rinehart said.

"We had to give some very ancient proteins a few modern upgrades," Söll said.

Söll and Rinehart now are attempting to create proteins in states known to be linked to cancer, type 2 diabetes, and hypertension. Both men, however, stressed the technique can be done for any type of protein.

"Dr. Söll and his colleagues have provided researchers with a powerful new tool to use in uncovering how cells regulate a broad range of processes, including cell division, differentiation and metabolism," said Michael Bender, who oversees protein synthesis grants at the National Institute of General Medical Sciences of the National Institutes of Health.

Other authors from Yale are lead authors Hee-Sung Park and Michael J. Hohn, Takuya Umehara and L-Tao Guo. They collaborated with Edith M. Osborne, Jack Benner, and Christopher J. Noren from New England Biolabs.

The work was funded by grants from the National Science Foundation and the National Institutes of Health via the National Institute of General Medical Sciences and the National Institute of Diabetes and Digestive and Kidney Diseases.

Interbreeding Between Modern Humans and Evolutionary Cousins Gave Healthy Immune System Boost to Human Genome, Study Finds

Laurent Abi-Rached, Paul Norman and Libby Guethlein are co-authors of research on how the genome of geographically-distinct human populations vary in the amount and type of immune-system genes inherited from evolutionary cousins, the Neanderthals and Denisovans. People in Papua New Guinea, for instance, have a particularly high percentage of one type of immune-system gene that is rarely found in people in Africa. (Credit: Norbert von der Groeben)

Science Daily — For a few years now, scientists have known that humans and their evolutionary cousins had some casual flings, but now it appears that these liaisons led to a more meaningful relationship.

Although modern humans, Neanderthals and Denisovans share a common ancestor in Africa, the groups split into separate, distinct populations approximately 400,000 years ago. The Neanderthal lineage migrated northwestward into West Asia and Europe, and the Denisovan lineage moved northeastward into East Asia. The ancestors of modern man stayed in Africa until 65,000 years or so ago, when they expanded into Eurasia and then encountered the other human-like groups. In some cases, the rendezvous were amorous in nature.

Sex with Neanderthals and another close relative -- the recently discovered Denisovans -- has endowed some human gene pools with beneficial versions of immune system genes, report researchers at the Stanford University School of Medicine in an article to be published online by the journal Science at the Science Express website on Aug. 25.

Last year, a partial genome sequence of Neanderthals, who died out approximately 30,000 years ago, revealed that these trysts left as much as 4 percent Neanderthal DNA in the genetic blueprint of some present-day humans. Last December, the genome of another human cousin, the extinct Denisovans, made clear that up to 6 percent of some people's genomes are Denisovan in origin.

Now, a team of researchers led by Peter Parham, PhD, professor of structural biology and of microbiology and immunology, has found that these matings had a positive effect on modern human fitness. "The cross breeding wasn't just a random event that happened, it gave something useful to the gene pool of the modern human," said Parham, who is senior author on the study.

The useful gift was the introduction of new variants of immune system genes called the HLA class I genes, which are critical for our body's ability to recognize and destroy pathogens. HLA genes are some of the most variable and adaptable genes in our genome, in part because the rapid evolution of viruses demands flexibility on the part of our immune system.

"The HLA gene system, with its diversity of variants, is like a magnifying glass," said lead author Laurent Abi-Rached, PhD, explaining that it provides a lot more detail about the history of populations than typical gene families. Abi-Rached is a research associate in the Parham lab.

Prior to the sequencing of the Neanderthal and Denisovan genomes, Parham and his group had suspected that at least one HLA variant came from archaic humans. They determined that the variant known as HLA-B*73 is rare in present-day African populations but occurs with significant frequency in West Asian populations. The ethnic distribution of HLA-B*73 and its similarity across populations suggested that it came from a relatively recent co-mingling of modern human and archaic human DNA, which most likely would have happened outside of Africa. Parham's team wanted to discern which archaic humans were the source of the HLA-B*73 gene type. In the last year they have found the answer in the genome sequence of a recently discovered human relative, the Denisovans, whose existence first came to light in 2008 with the discovery of an unfamiliar finger bone and tooth in a cave in Siberia.

By comparing the HLA genes of the archaic humans with modern humans, the researchers were able to show that the HLA-B*73 allele likely came from cross breeding with Denisovans. Little is known about what the Denisovans looked like (the finger bone and the tooth are the only known fossils), but the genome sequence extracted from the finger bone gives insight into where they overlapped with modern humans. Gene flow from the Denisovans into modern humans has left the highest frequency of the HLA-B*73 allele in populations in West Asia, the most likely site for the fortuitous mating to have taken place.

Even in West Asian populations, the HLA-B*73 variant never represents more than 5 percent of all known variants of that gene. However, other human HLA types that arose from ancient matings are found in much greater frequencies. "Certain traits coming from these archaic humans have become the dominant form," said Parham. For example, another HLA gene type, called HLA-A*11, is absent from African populations, but represents up to 64 percent of variants in East Asia and Oceania, with the greatest frequency in people from Papua New Guinea. "The likely interpretation was that these HLA class variants provided an advantage to modern human and so rose to high frequencies," Parham said.

A similar scenario is seen in some HLA gene types found in the Neanderthal genome, which was also sequenced from DNA extracted from ancient bones. These gene variants are common in European and Asian populations but rare in African populations. "We are finding frequencies in Asia and Europe that are far greater than whole genome estimates of archaic DNA in modern human genomes, which is 1 to 6 percent," said Parham. Within one class of HLA gene, the researchers estimate that Europeans owe half of their variants to interbreeding with Neanderthals and Denisovans, Asians owe up to 80 percent and Papua New Guineans, up to 95 percent.

"This is not the pattern seen genome-wide," said Abi-Rached. "The HLA system is unique in its diversity and the strength of natural selection acting on it, but it's possible that other gene systems, particularly the ones under similar pressure for variation, could show a similar pattern."

Other Stanford-affiliated authors include Matthew Jobin, PhD, lecturer in the Department of Anthropology; postdoctoral scholar Subhash Kulkarni, PhD; research assistant Farbod Babrzadeh; visiting scholar Baback Gharizadeh, PhD; and research associates Lisbeth Guethlein, PhD, and Paul Norman, PhD. The Stanford researchers collaborated with colleagues at the Royal Free Hospital, in the United Kingdom; Ankara University, in Turkey; the National Marrow Donor Program, in Minneapolis; the University of Manitoba; the University of Nairobi; the National Cancer Institute; Liverpool University; UCLA; Canadian Blood Services; and UC-Santa Cruz.

The study was funded by National Institutes of Health, the Yerkes Center, the National Science Foundation and the National Cancer Institute.

Pulsar Transformed Into Small Planet Made of Diamond Discovered in Milky Way

The pulsar at the centre of the below image is orbited by an object that is about the mass of Jupiter and composed primarily of carbon; effectively a massive diamond. The orbit, represented by the dashed line, would easily fit inside our Sun, represented by the yellow surface. The blue lines represent the radio signal from the pulsar, which spins around 175 times every second. (Credit: Swinburne Astronomy Productions)

Science Daily  — A once-massive star that's been transformed into a small planet made of diamond: that's what astronomers think they've found in our Milky Way.

The discovery, reported in Science, was made by an international research team led by Professor Matthew Bailes, Pro Vice-Chancellor (Research) at Swinburne University of Technology in Melbourne and the 'Dynamic Universe' theme leader in a new wide-field astronomy initiative, the ARC Centre of Excellence for All-sky Astrophysics (CAASTRO).

The researchers, from Australia, Germany, Italy, the UK and the USA, first detected an unusual star called a pulsar using the CSIRO Parkes radio telescope and followed up their discovery with the Lovell radio telescope in the UK and one of the Keck telescopes in Hawaii.

Pulsars are small spinning stars about 20 km in diameter -- the size of a small city -- that emit a beam of radio waves. As the star spins and the radio beam sweeps repeatedly over Earth, radio telescopes detect a regular pattern of radio pulses.

For the newly discovered pulsar, known as PSR J1719-1438, the astronomers noticed that the arrival times of the pulses were systematically modulated. They concluded that this was due to the gravitational pull of a small companion planet, orbiting the pulsar in a binary system.

The pulsar and its planet are part of the Milky Way's plane of stars and lie 4,000 light-years away in the constellation of Serpens (the Snake). The system is about an eighth of the way towards the Galactic Centre from Earth.

The modulations in the radio pulses tell astronomers several things about the planet.

First, it orbits the pulsar in just two hours and ten minutes, and the distance between the two objects is 600,000 km -- a little less than the radius of our Sun.

Second, the companion must be small, less than 60,000 km (that's about five times Earth's diameter). The planet is so close to the pulsar that, if it were any bigger, it would be ripped apart by the pulsar's gravity.

But despite its small size, the planet has slightly more mass than Jupiter.

"This high density of the planet provides a clue to its origin," said Professor Bailes.

A star is torn

The team thinks that the 'diamond planet' is all that remains of a once-massive star, most of whose matter was siphoned off towards the pulsar.

Pulsar J1719-1438 is a very fast-spinning pulsar -- what's called a millisecond pulsar. Amazingly, it rotates more than 10,000 times per minute, has a mass of about 1.4 times that of our Sun but is only 20 km in diameter. About 70 per cent of millisecond pulsars have companions of some kind. Astronomers think it is the companion that, in its star form, transforms an old, dead pulsar into a millisecond pulsar by transferring matter and spinning it up to a very high speed. The result is a fast-spinning millisecond pulsar with a shrunken companion -- most often a so-called white dwarf.

"We know of a few other systems, called ultra-compact low-mass X-ray binaries, that are likely to be evolving according to this scenario and may likely represent the progenitors of a pulsar like J1719-1438," said team member Dr Andrea Possenti, Director of the INAF-Osservatorio Astronomico di Cagliari in Italy.

But pulsar J1719-1438 and its companion are so close together that the companion can only be a very stripped-down white dwarf, one that has lost its outer layers and over 99.9 per cent of its original mass.

"This remnant is likely to be largely carbon and oxygen, because a star made of lighter elements like hydrogen and helium would be too big to fit the measured orbiting times," said Dr Michael Keith (CSIRO), one of the research team members.

The density means that this material is certain to be crystalline: that is, a large part of the star may be similar to a diamond.

"The ultimate fate of the binary is determined by the mass and orbital period of the donor star at the time of mass transfer. The rarity of millisecond pulsars with planet-mass companions means that producing such 'exotic planets' is the exception rather than the rule, and requires special circumstances," said Dr Benjamin Stappers from the University of Manchester.

The team found pulsar J1719-1438 among almost 200,000 Gigabytes of data using special codes on supercomputers at Swinburne University of Technology, The University of Manchester, and the INAF-Osservatorio Astronomico di Cagliari..

The discovery was made during a systematic search for pulsars over the whole sky that also involves the 100 metre Effelsberg radio telescope of the Max-Planck-Institute for Radioastronomy (MPIfR) in Germany. "This is the largest and most sensitive survey of this type ever conducted. We expected to find exciting things, and it is great to see it happening. There is more to come!" said Professor Michael Kramer, Director of the MPIfR.

Professor Matthew Bailes is a member of the Centre for Astrophysics and Supercomputing at Swinburne which is uniquely resourced to process the torrents of data generated by telescopes and simulations

Hindi Devotional Song - Shirdi Wale Baba - Sai Ke Khel Nirale

sri

Poor ‘brain’ reasoning: obesity

THE UNIVERSITY OF NEW SOUTH WALES

New research suggests obese individuals often perform poorly in reasoning and planning tasks and, likewise, those with poor cognitive function are more vulnerable to excessive weight gain. The controversial findings, published this week in the international journal Obesity Reviews, suggests that obesity should be treated, at least in part, as a brain condition, similar to anorexia nervosa. This could mean introducing cognitive remediation therapy used to treat anorexia to support other lifestyle interventions for people with obesity. Cognitive remediation therapy aims at improving executive function via cognitive training and increases awareness of cognitive style. Australia is one of the most overweight developed nations in the world, according to the Federal Government’s Preventative Health Task Force, with over 60 per cent of adults and one in four children overweight or obese. Reviewing 38 recent studies into obesity and cognition, researchers from UNSW’s School of Psychiatry found there was a likely “vicious cycle” relationship between cognition and obesity, with low performance in planning, reasoning and problem solving exacerbating weight gain, which in turn compounds negative influence on the brain via biological mechanisms. This relationship was not explained by other factors such as medical problems or social status, and was apparent in children, adolescents and adults, but not in the elderly whose situation is more complex. However the research does support existing studies that show mid-life obesity is a risk factor for dementia in later life. The reviewers said obesity is, at least in part, a brain condition, not only a so-called “lifestyle” disorder. There is evidence of a common genetic vulnerability for both obesity and impairments in thinking style which could be triggered by lifestyle factors. Review lead author Dr Evelyn Smith said the finding was controversial, but what it didn’t mean was that all obese people have cognitive deficiencies. “However, on average they do have more problems with problem solving and other ‘executive’ brain or cognitive functions than normal weight individuals,” she said. “Executive function is the most common cognitive deficiency found in obese individuals. It encompasses a diverse range of processes that facilitate initiation, planning and achievement of complex goals, all of which may impact on eating behaviour and activity.” Cognitive remediation therapy similar to that used to treat individuals with anorexia could be an effective intervention for obesity, by improving certain cognitive processes and in turn helping individuals maintain a healthy lifestyle long term, Dr Smith said. Dr Smith is now piloting the therapy as a way to help the obese lose weight and keep it off long term, in collaboration with Kings College London and University of Western Sydney (UWS). “Because current strategies for treating obesity are not successful long-term, there’s an urgency to invest in new obesity research,” Dr Smith said. “Additional investigations are required to further understand the biological mechanisms and bi-directional relationship between cognition and obesity, and also to confirm whether executive function in children and adolescents can predict obesity in adults,” she said. Dr Smith’s review was supported by a grant from the National Health & Medical Research Council of Australia, and was carried out in collaboration with Professor Phillipa Hay (UWS), Conjoint Professor Lesley Campbell (UNSW), and Associate Professor Julian Trollor (UNSW).

Super dense metal from ‘boom’

THE AUSTRALIAN NATIONAL UNIVERSITY

The group has discovered a way to produce body-centred-cubic aluminium, which is 40 per cent more dense. Image:blackred/iStockphoto An international team of researchers including scientists from The Australian National University have created a new, super-dense version of aluminium that could lead to efficient production of new super-hard nanomaterials at a relatively low cost. In a paper published today in Nature Communications, the group has described how they discovered a way to produce body-centred-cubic aluminium, which is 40 per cent more dense. Super-hard aluminium was predicted to exist more than 30 years ago but has never before been observed. Professor Andrei Rode from the Laser Physics Centre at ANU said the state of any material depends on temperature and pressure. “For example, water turns into ice at low temperatures and hydrogen gas actually becomes metallic under extreme pressure in the middle of a star,” he said. “Lab experiments on producing high pressure and temperature generally use a diamond anvil with a point on one end to produce high pressure but this is limited by the strength of the diamond, which in the case of aluminium, is not hard enough to crush into a new state. “We demonstrated that it is possible to create extreme pressure and temperature conditions in table-top laboratory experiments using an extremely short laser pulse to create a huge concentration of energy in a very short time and in a very small sub-micron volume inside a sapphire crystal, which is aluminium oxide. “This experiment resulted in something like a micro-explosion which turned the aluminium to a plasma state that swelled but had nowhere else to go, creating gigantic pressure and dramatic changes in surrounding material properties and producing unfamiliar x-ray spectral lines. “We did a lot of work using theoretical modelling to identify the spectral lines, which were in very unusual positions with various aluminium oxide crystal configurations, but could not find a satisfactory match between theory and experiment. “We were about to abolish the search, when we had the crazy idea to compare any possible aluminium crystal phases to the observed spectra. The idea was considered crazy because it contradicted a conventional wisdom that aluminium surrounded by oxygen must be oxidised in normal condition. “But to paraphrase Niels Bohr, a Nobel Prize laureate in physics, the discovery of a new aluminium phase proved that ‘… the idea was crazy enough to be true’. “This discovery shows a new way to form warm dense matter in relatively inexpensive table-top laboratory experiments and could also improve our understanding of the deep Earth core and planetary sciences.”

Fruit bacteria to curb dengue

THE UNIVERSITY OF MELBOURNE

Researchers have stopped the insects from spreading the dengue virus by infecting mosquitoes with bacteria from flies that commonly live in kitchen fruit bowls. The work was conducted by an international team of scientists from the Eliminate Dengue program and was published today in two papers in the journal Nature. Co-authors include researchers from the University of Melbourne, Monash University and James Cook University. The second paper also shows how the fruitfly bacteria was established in wild mosquito populations, offering a practical and inexpensive way to stop transmission of dengue fever which affects 50 million people annually. The strain of dengue-blocking bacteria called wMel Wolbachia, was first discovered in Australian fruit flies in 1988 by Professor Ary Hoffmann from the Bio21 Institute, University of Melbourne. “Amazingly, Aussie fruit bacteria can effectively immunise mosquitoes against dengue, thereby preventing its spread to humans,” Professor Hoffmann said. “Our finding has the potential to halt the spread of the dengue virus which is vital as there is currently no vaccine and the geographical areas of infection are growing.” The World Health Organisation ranks dengue fever as the most important mosquito-borne viral disease in the world, with an estimated 2.5 billion people living in dengue infected areas. The dengue virus mainly causes extreme fatigue and fever, but it kills around 1 in 500 infected people, mainly children. There have been around 2,400 cases of dengue infection in Northern Australia in recent years. Other Wolbachia bacteria strains live naturally inside around 70 per cent of all insects and are known to protect them against viral infection. But the team is the first to introduce the particular wMel Wolbachia strain into disease-carrying mosquitoes and to establish it in natural populations during field trials in Queensland, Australia. “This Wolbachia strain is important because, after years of experiments, it is the first one trialled that does not have any major side effects for the mosquito to carry and can survive through the dry season. Wolbachia rapidly infects the wild mosquito population because it is inherited directly from the mother through the egg,” Professor Hoffmann said. “Current control methods, mainly based on insecticides are failing to stop the global dengue problem and some mosquitoes are developing resistance. The benefit of the Wolbachia control method is that it is a cheaper biological control that communities could employ themselves, without using insecticides.” Following years of community engagement and their overwhelming support, in January this year mosquitoes carrying Wolbachia were released in the Cairns suburbs of Yorkeys Knob and Gordonvale. Within three months, 100 per cent of the mosquitoes at Yorkeys Knob and 90 per cent in Gordonvale carried Wolbachia. “These findings tell us that Wolbachia-based strategies are practical to implement and might hold the key to a new cheap and sustainable approach to dengue control, an approach that should be particularly suited to large cities of the developing world,” Professor Hoffmann said. The program will next undertake further trials in Cairns to test how well Wolbachia spreads across less contained areas than the initial trial sites. The team also aims to conduct trials in areas with endemic dengue infection such as Thailand, Vietnam, Brazil and Indonesia to directly determine the effectiveness of the method in reducing dengue disease in human populations.

Heat leads to future energy

RMIT UNIVERSITY

RMIT University researchers have explored how thermopower waves in thermoelectric materials can convert heat from solid fuels into electrical energy, in research that advances the vision of 'smartdust' and other truly autonomous micro and nanomachines. In a research paper published in Issue 9 (23 August, 2011) of the high impact journal, Energy & Environmental Science, the researchers outline the creation of new semiconducting structures for the generation of thermopower waves at the micro-scale - a new technology that could enable tiny power sources with unprecedented capacity. Study supervisor, Associate Professor Kourosh Kalantar-zadeh, said thermopower waves could be used as micro-power sources for a broad range of miniaturized applications. "Tiny electronic devices powered by thermopower waves could apply large energies to targeted cancer cells inside the human body, enabling an exceptional level of precision in cancer treatment," he said. "They could help realise concepts like 'smartdust' - micro-electromechanical systems that are networked wirelessly for sensing and receiving data, for example testing pH of soil in large agricultural fields or quality of water reserves." Lead author Sumeet Walia, a doctoral researcher in the Microplatforms Research Group at RMIT, said the size of power sources had not kept pace with the ever-reducing size of electronics. "The development of miniaturized energy sources is a key challenge to overcome in order to build the next generation of electronic devices," Mr Walia said. "We focus on thermopower waves - which generate intense waves of electrical current by sweeping electrical carriers from one end of materials to another - because of their potential for creating small scale power sources that can release energy at very high rates. "Our work demonstrates a new class of micro-power sources and shows it is possible to obtain alternating output signals with opposite polarities, which is crucial for developing alternating signal sources. "This is an important milestone towards making efficient thermopower wave systems for future industrial applications." Mr Walia co-authored the study with researchers from the CSIRO and University of New South Wales, under the supervision of Associate Professor Kalantar-zadeh.

Painless Protein Scaffold Lets Cavity-Ridden Teeth Re-Grow From the Inside Out

By Rebecca Boyle

Dental Drills and Heads Ingsoc via Flickr

A new tooth-regenerating paste could reverse bacterial-induced tooth decay, sweeping dental drills into the dustbin of history. Hopefully.

As your hygienist probably told you, tooth decay happens when bacteria in plaque dissolve your enamel, creating cavities. Eventually the cavity gets big enough that your dentist has to take out the decay and drill a hole that can be filled with resin, gold or something else. But a new treatment developed at the University of Leeds in the UK reverses the decay, allowing your teeth to rebuild themselves.

Researchers led by Jennifer Kirkham at the Leeds Dental Institute developed an amino acid toothpaste that contains a compound that assembles into fibers. When it’s applied to a decayed tooth, this peptide paste forms a gelatinous scaffold that attracts calcium, enabling the tooth to rebuild itself from within. Tissue and bone scaffolds are used to seed new organs and new bones — why not teeth?

This procedure also avoids the use of stem cells, which also hold great promise for regenerating teeth. One such treatment also uses a scaffold, but instead of inducing calcium building blocks, itseeds the scaffold with stem cells. Just last month, we heard about a different project to re-grow mice molars in vitro and transplant them back into the mice. But a stem-cell-free toothpaste that grows new teeth in situ would conceivably be less painful, not to mention less controversial.

The team has already tested this in humans, according to a Leeds news release. A small group of patients with the early signs of tooth decay received a treatment with the peptide solution, known as P 11-4, and results suggest the damage was reversed, the release says.

A dentist would still have to clean out the decay, so it’s not clear that the dental drill will be entirely eliminated with this new toothpaste. But it’s a step toward making dental visits a lot more pleasant.

NASA's Infrared Explorer Spots a Room-Temperature Brown Dwarf, the Coldest Star Ever Found

It's one of the closest stars we've seen, but it's so cool we didn't notice it before

By Rebecca Boyle

Y Dwarf Y dwarfs are the coldest star-like bodies known, with temperatures that can be even cooler than the human body. NASA's Wide-field Infrared Survey Explorer just found them for the first time. NASA/JPL-Caltech

Using NASA’s Wide-field Infrared Survey Explorer telescope, astronomers have finally spotted a collection of ultra-cool brown dwarfs they have been hunting for more than a decade. These tepid almost-star orbs are nearly impossible to see with a normal telescope, but WISE’s infrared vision was able to pick them out.

The coldest one ever found is about room temperature, with a reading of less than 80 degrees. That brown dwarf, a Y-class dwarf called WISE 1828+2650, is the green dot in the image below.

Brown dwarfs, sometimes called failed stars, got their name because astronomers didn’t know what color they would have in the visible spectrum. Some classes of brown dwarfs would actually look more reddish than brown, according to NASA. Scientists don’t know what color a Y dwarf would actually be if it was visible — the image above is purple for artistic reasons.

They start out the same way as a normal star, collapsing under their own weight. But they don’t have enough mass to ignite thermonuclear fusion at their cores, so they cool and fade after their birth. Their atmospheres are more like Jupiter’s than a star’s, and this makes them very hard to find in deep space.

Astronomers have 10 classifications for stars, starting with the hottest: O, B, A, F, G, K, M, L, T, and now Y. The sun is a G-class star, in case you were counting. Objects O through K are considered stars; M and L are mixes of brown dwarfs and stars; and T and now Y are all brown dwarfs.

“The brown dwarfs we were turning up before this discovery were more like the temperature of your oven,” said Davy Kirkpatrick, a WISE science team member, in a NASA news release. “With the discovery of Y dwarfs, we've moved out of the kitchen and into the cooler parts of the house.”

In all, WISE found 100 new brown dwarfs, including six Y dwarfs that were all between nine and 40 light years away from our sun. The Y dwarf called WISE 1541-2250 is only nine light years away, so it might become the seventh-closest star system to us, knocking Ross 154 to the eighth spot, NASA said. And there are probably plenty of others, so WISE will keep looking for even closer stellar neighbors.

A report on the six brown dwarfs appears in the Astrophysical Journal.

Coldest Brown Dwarf Ever: The green dot in the center is the coldest brown dwarf star ever discovered, with a temperature less than that of a human body (less than 80 degrees F).  NASA/JPL-Caltech/UCLA

NASA's Laser Communications System Will Enable High-Speed Transmissions From Mars

By Clay Dillow

NASA's Laser Communications Relay Demonstration (LCRD), Visualized NASA

NASA is spending roughly $175 million on three new technology demonstration projects, one of which is aiming to take HD data streaming to Mars. The Laser Communications Relay Demonstration (LCRD) will explore reliable optical communications technologies that could boost data rates between Earth and deep space by a couple of orders of magnitude.

The premise is simple enough: for the same mass, size, and power load an optical communications system can provide drastically higher data rates compared to standard radio frequency (RF) systems. But it also calls for a trickier setup, requiring a clear line of sight between transmitter and receiver and considerations for variables like weather and atmospheric conditions.

The LCRD aims to demonstrate that a near earth space terminal (in this case a satellite owned by Loral Space & Communications, a partner in the project) can maintain optical communications with ground stations on Earth (one existing station in California and a couple more that will be built) and to test work around for problems that engineers foresee, like the aforementioned weather problem.

Such laser-based data transfers could increase data rates by anywhere from 10 to 100 times. Says NASA via press release:

As an example, at the current limit of 6 Mbps for the Mars Reconnaissance Orbiter (MRO), it takes approximately 90 minutes to transmit a single HiRISE high resolution image back to earth. In some instances, this bottleneck can limit science return. An equivalent MRO mission outfitted with an optical communications transmitter would have a capacity to transmit data back to earth at 100 Mbps or more, reducing the single image transmission time to on order of 5 minutes.

Eventually, the agency hopes to up those speeds such that data transfer speeds from places like the moon and Mars will be super-fast--perhaps fast enough to stream HD footage from the Martian surface, for instance. In the meantime, LCRD will develop the technology-sharing framework and a system of operational standards so private industry can get to work building the optical comms of the future.

By the way, the other two demo projects are pretty awesome as well: A space-based atomic clock to enable a kind of celestial GPS, and a mission-capable solar sail. More via the link below.