Posts by AltonParrish:
New APP Monitors mental health through “selfie”videos, social media
February 4th, 2015By University of Rochester.
Researchers at the University of Rochester have developed an innovative approach to turn any computer or smartphone with a camera into a personal mental health monitoring device.
In a paper to be presented this week at the American Association for Artificial Intelligence conference in Austin, Texas, Professor of Computer Science Jiebo Luo and his colleagues describe a computer program that can analyze “selfie” videos recorded by a webcam as the person engages with social media.
Apps to monitor people’s health are widely used, from monitoring the spread of the flu to providing guidance on nutrition and managing mental health issues. Luo explains that his team’s approach is to “quietly observe your behavior” while you use the computer or phone as usual. He adds that their program is “unobtrusive; it does not require the user to explicitly state what he or she is feeling, input any extra information, or wear any special gear.” For example, the team was able to measure a user’s heart rate simply by monitoring very small, subtle changes in the user’s forehead color. The system does not grab other data that might be available through the phone – such as the user’s location.
The researchers were able to analyze the video data to extract a number of “clues,” such as heart rate, blinking rate, eye pupil radius, and head movement rate. At the same time, the program also analyzed both what the users posted on Twitter, what they read, how fast they scrolled, their keystroke rate and their mouse click rate. Not every input is treated equally though: what a user tweets, for example, is given more weight than what the user reads because it is a direct expression of what that user is thinking and feeling.
To calibrate the system and generate a reaction they can measure, Luo explained, he and his colleagues enrolled 27 participants in a test group and “sent them messages, real tweets, with sentiment to induce their emotion.” This allowed them to gauge how subjects reacted after seeing or reading material considered to be positive or negative.
They compared the outcome from all their combined monitoring with the users’ self reports about their feelings to find out how well the program actually performs, and whether it can indeed tell how the user feels. The combination of the data gathered by the program with the users’ self-reported state of mind (called the ground truth) allows the researchers to train the system. The program then begins to understand from just the data gathered whether the user is feeling positive, neutral or negative.
Their program currently only considers emotions as positive, neutral or negative. Luo says that he hopes to add extra sensitivity to the program by teaching it to further define a negative emotion as, for example, sadness or anger. Right now, this is a demo program they have created and no “app” exists, but they have plans to create an app that would let users be more aware of their emotional fluctuations and make adjustments themselves.
Luo understands that this program and others that aim to monitor an individual’s mental health or well-being raise ethical concerns that need to be considered. He adds that using this system means “effectively giving this app permission to observe you constantly,” but adds that the program is designed for the use of the user only and does not share data with anyone else unless otherwise designated by the user.
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Green tea compound kills oral cancer cells
February 4th, 2015
By the American Institute of Cancer Research.
A compound found in green tea may trigger a cycle that kills oral cancer cells while leaving healthy cells alone, according to Penn State food scientists. The research could lead to treatments for oral cancer, as well as other types of cancer.
Earlier studies had shown that epigallocatechin-3-gallate — EGCG — a compound found in green tea, killed oral cancer cells without harming normal cells, but researchers did not understand the reasons for its ability to target the cancer cells, said Joshua Lambert, associate professor of food science and co-director of Penn State’s Center for Plant and Mushroom Foods for Health. The current study shows that EGCG may trigger a process in the mitochondria that leads to cell death.
“EGCG is doing something to damage the mitochondria and that mitochondrial damage sets up a cycle causing more damage and it spirals out, until the cell undergoes programmed cell death,” said Lambert. “It looks like EGCG causes the formation of reactive oxygen species in cancer cells, which damages the mitochondria, and the mitochondria responds by making more reactive oxygen species.”
As this mitochondrial demise continues, the cancer cell also reduces the expression of anti-oxidant genes, further lowering its defenses.
“So, it’s turning off its mechanism of protection at the same time that EGCG is causing this oxidative stress,” Lambert added.
The EGCG did not cause this reaction in normal cells. In fact, it appeared to increase the protective capabilities of the cell, according to the researchers, who report their findings in the online issue of Molecular Nutrition and Food Research.
The appearance of green tea in three different stages (from left to right): the infused leaves, the dry leaves, and the liquid. Notice that the infused leaves look greener than the dry leaves.
The researchers studied normal human oral cells side-by-side with human oral cancer cells to determine how EGCG was affecting cancer cells differently than normal cells. They grew the normal and cancer cells on petri dishes and then exposed them to EGCG, the major polyphenol found in green tea, at concentrations typically found in the saliva after chewing green-tea chewing gum. At various times, the researchers would collect the cells and check for oxidative stress and signs of antioxidant response.
“We also took a lot of pictures, so we could use fluorescent dyes that measure mitochondrial function and oxidative stress and actually see these things develop,” said Lambert, who worked with Jong-Yung Park, a research technician and Ling Tao, a doctoral candidate in food science.
The researchers said that a protein called sirtuin 3 — SIRT3 — is critical to the process.
“It plays an important role in mitochondrial function and in anti-oxidant response in lots of tissues in the body, so the idea that EGCG might selectively affect the activity of sirtuin 3 in cancer cells — to turn it off — and in normal cells — to turn it on — is probably applicable in multiple kinds of cancers,” Lambert said.
The study builds on earlier research on how EGCG affected oral cancer, a disease that is expected to kill more than 8,000 people in the United States this year.
“We’ve published one paper previously just looking at the effect of these green tea polyphenols on oral cancer cells in cultures, and there have been other papers published using oral cancer cells and at least a couple of animal model studies that have looked at oral cancer and prevention of oral cancer,” said Lambert.
He said the next step would be to study the mechanism in animals. If those tests and human trials are successful, the researchers then hope to create anti-cancer treatments that are as effective as current treatments without the harmful side effects.
“The problem with a lot of chemotherapy drugs — especially early chemotherapy drugs — is that they really just target rapidly dividing cells, so cancer divides rapidly, but so do cells in your hair follicles and cells in your intestines, so you have a lot of side effects,” said Lambert. “But you don’t see these sorts of side effects with green tea consumption.”
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Global firestorm generated by dinosaur-killing asteroid doubted
January 25th, 2015By Alton Parrish.
Pioneering new research has debunked the theory that the asteroid that is thought to have led to the extinction of dinosaurs also caused vast global firestorms that ravaged planet Earth.
A team of researchers from the University of Exeter, University of Edinburgh and Imperial College London recreated the immense energy released from an extra-terrestrial collision with Earth that occurred around the time that dinosaurs became extinct. They found that the intense but short-lived heat near the impact site could not have ignited live plants, challenging the idea that the impact led to global firestorms.
An extra-terrestrial collision with Earth occurred around the time that dinosaurs became extinct.
Image courtesy of NASA
These firestorms have previously been considered a major contender in the puzzle to find out what causedthe mass extinction of life on Earth 65 million years ago.
The researchers found that close to the impact site, a 200 km wide crater in Mexico, the heat pulse – that would have lasted for less than a minute – was too short to ignite live plant material. However they discovered that the effects of the impact would have been felt as far away as New Zealand where the heat would have been less intense but longer lasting – heating the ground for about seven minutes – long enough to ignite live plant matter.
The experiments were carried out in the laboratory and showed that dry plant matter could ignite, but live plants including green pine branches, typically do not.
Dr Claire Belcher from the Earth System Science group in Geography at the University of Exeter said: “By combining computer simulations of the impact with methods from engineering we have been able to recreate the enormous heat of the impact in the laboratory. This has shown us that the heat was more likely to severely affect ecosystems a long distance away, such that forests in New Zealand would have had more chance of suffering major wildfires than forests in North America that were close to the impact. This flips our understanding of the effects of the impact on its head and means that palaeontologists may need to look for new clues from fossils found a long way from the impact to better understand the mass extinction event.”
Plants and animals are generally resistant to localised fire events – animals can hide or hibernate and plants can re-colonise from other areas, implying that wildfires are unlikely to be directly capable of leading to the extinctions. If however some animal communities, particularly large animals, were unable to shelter from the heat, they may have suffered serious losses. It is unclear whether these would have been sufficient to lead to the extinction of species.
Dr Rory Hadden from the University of Edinburgh said: “This is a truly exciting piece of inter-disciplinary research. By working together engineers and geoscientists have tackled a complex, long-standing problem in a novel way. This has allowed a step forward in the debate surrounding the end Cretaceous impact and will help geoscientists interpret the fossil record and evaluate potential future impacts. In addition, the methods we developed in the laboratory for this research have driven new developments in our current understanding of how materials behave in fires particularly at the wildland-urban-interface, meaning that we have been able to answer questions relating to both ancient mass extinctions at the same time as developing understanding of the impact of wildfires in urban areas today.”
The results of the study are published in the Journal of the Geological Society.
The research was supported by a European Research Council Starter Grant, a Marie Curie Career IntegrationGrant, the Leverhulme Trust, the EPSRC and the Austrian Science Fund.
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How does a machine smell? Better than it did
January 17th, 2015By Alton Parrish.
Every odor has its own specific pattern which our noses are able to identify. Using a combination of proteinscoupled to transistors, for the first time machines are able to differentiate smells that are mirror images of each other, so called chiral molecules, something that has not been possible before.
The human nose can distinguish between some of these molecules and the different forms of the same molecule of carvone, for example, can smell either like spearmint or caraway. Previous machines would not have been able to distinguish between the two.
Credit: edudiagrams.blogspot.com
The development will allow the creation of a new generation of biosensors with an acute ability to sniff out problems. These could have many industrial uses such as telling when food has gone off, and they could even be accurate enough to smell how much pollution is in the atmosphere.
A collaboration of academics from The University of Manchester and the University of Bari in Italy, have created a biosensor that utilizes an odorant binding protein. The team’s findings are published today in the journal Nature Communications.
Odorant binding proteins are found in the mucus of the nose, which work olfactory receptors helping us to create our perception of smell. The team have found a method of manufacturing these proteins in quantities that would allow them to be used in biosensors.
They have developed methods to change the way the proteins react so that they can recognize different types of chemicals. Using a type of transistor incorporating these proteins the scientists were able to measure the unique changes in current as the proteins reacted to odors, and record them. This is in effect the machine smelling the odor and then sending the message, which can then be decoded.
The system is incredibly sensitive with a detection limit that approaches that of the human nose.
Professor Krishna Persaud, lead author of the paper at The University of Manchester, said: “It has been challenging to get machines to be able to differentiate between smells that are mirror images of each other, which was a real barrier to creating machines which are able to smell as well or better than humans.
“Using the expertise of our colleagues at the University of Bari to couple these proteins to field effect transistors has allowed us to produce a new chemical sensor platform. Now we have done this it will allow much better sensors to be developed and these could have many uses in industry. We shall be able to create biosensors which are accurate enough to be able to tell when food has gone off, or even smell how much pollution is in the atmosphere.”
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Closing your eyes boosts memory recall, new study finds
January 16th, 2015
By Alton Parrish.
Credit: University of Surrey
178 participants took part across two studies. In the first experiment, participants watched a film depicting an electrician entering a property, carrying out jobs and stealing items. Each participant was then randomly assigned one of four conditions, either eyes closed or open, and having built up a rapport with the intervieweror not. They were then asked a series of questions about the film, such as ‘what was written on the front of the van?’ The team found that closing their eyes led participants to answer 23 per cent more of the questions correctly. Building rapport also increased the number of correct answers, however, closing their eyes was effective regardless of whether rapport had been built or not.
The second experiment took the memory task one step further, by asking witnesses about things they had heard, as well as things they had seen. This time, participants watched a clip from Crimewatch, showing a reconstruction of a burglary where an elderly man was attacked in his home. Results showed that closing their eyes helped participants recall both audio and visual details, both when they had built rapport and when they had not.
Across both experiments, participants who did not build rapport said they felt less comfortable when they closed their eyes, compared to when they kept their eyes open. In contrast, participants who built rapport felt more comfortable when they closed their eyes.
“It is clear from our research that closing the eyes and building rapport help with witness recall,” said lead author Dr Robert Nash from the University of Surrey.
“Although closing your eyes to remember seems to work whether or not rapport has been built beforehand, our results show that building rapport makes witnesses more at ease with closing their eyes. That in itself is vital if we are to encourage witnesses to use this helpful technique during interviews.”
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Ancient martian meteorite provides clues to the planet’s history
January 4th, 2015By Alton Parrish.
A new analysis of a Martian rock that meteorite hunters plucked from an Antarctic ice field 30 years ago this month reveals a record of the planet’s climate billions of years ago, back when water likely washed across its surface and any life that ever formed there might have emerged.
Credit: NASA
Scientists from the University of California, San Diego, NASA and the Smithsonian Institution report detailedmeasurements of minerals within the meteorite in the early online edition of the Proceedings of the National Academy of Sciences this week.
“Minerals within the meteorite hold a snapshot of the planet’s ancient chemistry, of interactions between water and atmosphere,” said Robina Shaheen, a project scientist at UC San Diego and the lead author of the report.
The unlovely stone, which fell to Earth 13 thousand years ago, looked a lot like a potato and has quite a history. Designated ALH84001, it is the oldest meteorite we have from Mars, a chunk of solidified magma from a volcano that erupted four billion years ago. Since then something liquid, probably water, seeped through pores in the rock and deposited globules of carbonates and other minerals.
The carbonates vary subtly depending on the sources of their carbon and oxygen atoms. Both carbon and oxygen occur in heavier and lighter versions, or isotopes. The relative abundances of isotopes forms a chemical signature that careful analysis and sensitive measurements can uncover.
Mars’s atmosphere is mostly carbon dioxide but contains some ozone. The balance of oxygen isotopes within ozone are strikingly weird with enrichment of heavy isotopes through a physical chemical phenomenon first described by co-author Mark Thiemens, a professor of chemistry at UC San Diego, and colleagues 25 years ago.
“When ozone reacts with carbon dioxide in the atmosphere, it transfers its isotopic weirdness to the new molecule,” said Shaheen, who investigated this process of oxygen isotope exchange as a graduate student at the University of Heidelberg in Germany. When carbon dioxide reacts with water to make carbonates, the isotopic signature continues to be preserved.
The degree of isotopic weirdness in the carbonates reflects how much water and ozone was present when they formed. It’s a record of climate 3.9 billion years ago, locked in a stable mineral. The more water, the smaller the weird ozone signal.
This team measured a pronounced ozone signal in the carbonates within the meteorite, suggesting that although Mars had water back then, vast oceans were unlikely. Instead, the early Martian landscape probably held smaller seas.
“What’s also new is our simultaneous measurements of carbon isotopes on the same samples. The mix of carbon isotopes suggest that the different minerals within the meteorite had separate origins,” Shaheen said. “They tell us the story of the chemical and isotopic compositions of the atmospheric carbon dioxide.”
ALH84001 held tiny tubes of carbonate that some scientists saw as potential evidence of microbial life, though a biological origin for the structures has been discarded. On December 16, NASA announced another potential whiff of Martian life in the form of methane sniffed by the rover Curiosity.
Credit: NASA
Carbonates can be deposited by living things that scavenge the minerals to build their skeletons, but that is not the case for the minerals measured by this team. “The carbonate we see is not from living things,” Shaheen said. “It has anomalous oxygen isotopes that tell us this carbonate is abiotic.”
By measuring the isotopes in multiple ways, the chemists found carbonates depleted in carbon-13 and enriched in oxygen-18. That is, Mars’s atmosphere in this era, a period of great bombardment, had much less carbon-13 than it does today.
The change in relative abundances of carbon and oxygen isotopes may have occurred through extensive loss of Martian atmosphere. A thicker atmosphere would likely have been required for liquid water to flow on the planet’s chilly surface.
“We now have a much deeper and specific insight into the earliest oxygen-water system in the solar system,” Thiemens said. “The question that remains is when did planets, Earth and Mars, get water, and in the case of Mars, where did it go? We’ve made great progress, but still deep mysteries remain.”
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Fuel cells to connect our smartphones to the outside world
January 4th, 2015
By FCPOWEREDRBS.
Giancarlo Tomarchio, coordinator of the FCPOWEREDRBS project, explains how fuel cells can represent a real alternative to standard power sources.
Did you know that, in 2014 alone, worldwide smartphone usage has grown by 25 %? Or that most of the telecom sites connecting these smartphones to the outside world are off-grid? This increasing pressure on self-powered installations requires continued efforts to come up with ever more innovative, reliable, efficient, cost-effective and sustainable energy generators.
Currently, most sites for which connection to the electricity grid is not an option rely on batteries and diesel generators. However, the FCPOWEREDRBS project has set out to convince telecom operators and local administrations alike that fuel cells represent a real alternative to such standard power sources. To this end, the project — which involves European industries and research centres Dantherm Power AS (Denmark) and MES SA (Switzerland), electrolyser manufacturer GreenHydrogen (Denmark), the University of Rome, the EU’s Joint Research Centre and Ericsson — is testing a custom-made fuel cell solution on various sites across Italy. This specific solution has been engineered by the project team and integrates different energy provider components (fuel cells, photovoltaics and batteries) in the ‘most efficient and reliable way’.
For Giancarlo Tomarchio, coordinator of the project and Customer Project Manager at Ericsson, the ultimate goal of the project is clear: demonstrating the industrial readiness and the market appeal of Fuel Cell technology for off-grid telecom applications. In this exclusive interview with the research*eu results magazine, he tells us how advanced he and his team are with the field trials, and how they intend to demonstrate the advantages of hydrogen and fuel cells for delivering the expected power supply service.
What are the main objectives of the project?
FCPOWEREDRBS is a demo project within the Fuel Cells and Hydrogen Joint Undertaking Programme. We are conducting a set of field trials that aim to demonstrate the advantages of hydrogen and fuel cell technology for off-grid telecom applications. These trials consists in replacing the power supply of 15 radio base stations in the live network of selected Italian telecom operators with a new one based on our solution — which integrates different energy provider components (fuel cells, photovoltaics and batteries) with efficiency and reliability in mind.
We are also committed to other initiatives aiming to increase the visibility of the fuel cell technology and facilitate its penetration in the telecom market.
What is the added value of using hydrogen and fuel cell technology to power telecom stations?
Remotely located ‘Radio base stations’ (RBS) for Telecom applications are becoming more and more important with the increasing penetration of mobile services. As for many of these stations, the connection to the electricity grid is not an option, and specific off-grid power generation solutions are required and quite often based on diesel fuel generators. With the solution proposed by our project, the amount of unattended hours can be increased thanks to an efficient usage of the different energy sources and to the storage potential of H2. For a Telecom operator, this means lower operational costs. In general, we think that it’s possible to provide our customers (the Telecom operators) with certain benefits in terms of ‘Total cost of ownership’ (TCO), something that nowadays is a strong argument for any Energy Manager.
Moreover, the system includes a smart-metering and telecontrol system providing the operator with more details on the energy behaviour of their base station.
What were the main difficulties you faced in the project and how did you resolve them?
Even though this project is a demo, it is a major innovation for the telecom market. In all our activities, we have to challenge ourselves with the need to produce a system that complies with the demanding requirements of the telecom market: durability and reliability 24/7.. Some of the issues we faced are comparable to those occurring when introducing a new product to the market, in this case aggravated by the nature of the fuel in use.
Resorting to H2 storage in the system implies the adoption of specific processes and procedures in terms of safety. Joint work is needed between the project and the Telecom operators who accepted to host our solution on their sites, in order to customise existing O&M procedures.
When it was time to get the necessary authorisations from the different local administrations in the territories where the sites are located, we were sometimes faced with inconsistent knowledge of the national regulations, which led to misunderstandings and delays in obtaining permits.
We have adopted all the necessary precautions in order to avoid any loss of power for the radio station, as any interruption to the service would be the worst message to give, if we want to gain customers’ trust. Really, our goal is to create long-term trust in fuel cells within the world of telecommunications.
Where do you stand with the on-site demonstrations?
At the moment we have an agreement for installing 10 systems on Telecom Italia’s live network, and three on H3G Italia’s. We have already installed eight sites — five of which are now up and running — while the other sites are about to be connected. We expect a first annual projection of TCO by the end of 2014. The trial will then continue until next year to reach the 12 months of operation normally needed for the verification.
We are also finalising the agreement for an additional installation of a non-telecom application, but with similar electrical requirements.
Are you happy with the results of the project so far?
The project started at the beginning of 2012 with the initial purpose being to install a system which was a ‘simple’ integration of a commercial product. In reality, we discovered that, besides the system configuration tuning, some additional developments were needed both in the fuel cell equipment and in the control logic. These activities have been successfully carried out and the lab tests hold much promise. We will spend the next few months continuously monitoring the system behaviour and optimising the parameters to make the system as efficient as possible.
When do you expect this technology to hit the market?
An exact forecast is always difficult. We definitely think that the solution proposed has high market potential: worldwide, more than 100 000 new cell phone base stations are installed every year. Most of them are installed in emerging and developing countries with a poor grid infrastructure, which means they have batteries and/or a backup power generator installed. The majority of these new base stations could be set up with a fuel cell system for power generation, if the technologies were proven safe and if the systems were available at competitive costs.
The FCPOWEREDRBS project still has some way to go to prove that such benchmarks are being achieved and opening up the way for broader commercialisation.
What are the next steps for the project, and do you have any follow-up plans after its end?
For the project team, it is now time to consolidate the results, optimise the solution and disseminate the results. We have already begun training activities to raise awareness among the telecom engineers about the FC technology, and we will also continue to share the telecom requirements with the FC world.
Should the project become a success story, as we all hope, there will be some further work to do in order to industrialise the solution so that it can be considered as a real product. The introduction or integration into a larger portfolio is now our dream and final goal.
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How ‘microbial dark matter’ might cause disease
December 24th, 2014By Alton Parrish.
It is estimated by scientists that roughly half of bacteria living in human bodies is difficult to replicate for scientific research — which is why biologists call it “microbial dark matter.” Scientists, however, have long been determined to learn more about these uncultivable bacteria, because they may contribute to the development of certain debilitating and chronic diseases.
The left image shows the tight physical association between TM7x cells and XH001. The right image shows TM7x cells (red) attach to the surface of XH001 (white).
Credit: Batbileg Bor/UCLA and Ryan Hunter/U of Minnesota
Now, a landmark discovery by scientists at the UCLA School of Dentistry, the J. Craig Venter Institute and the University of Washington School of Dentistry has revealed insights into TM7’s resistance to scientific study and to its role in the progression of periodontitis and other diseases. Their findings shed new light on the biological, ecological and medical importance of TM7, and could lead to better understanding of other elusive bacteria.
The team’s findings are published online in the December issue of the Proceedings of the National Academy of Sciences.
“I consider this the most exciting discovery in my 30-year career,” said Dr. Wenyuan Shi, a UCLA professor of oral biology. “This study provides the roadmap for us to make every uncultivable bacterium cultivable.”
The researchers cultivated a specific type of TM7 called TM7x, a version of TM7 found in people’s mouths, and found the first known proof of a signaling interaction between the bacterium and an infectious agent called Actinomyces odontolyticus, or XH001, which causes mucosal inflammation.
“Once the team grew and sequenced TM7x, we could finally piece together how it makes a living in the human body,” said Dr. Jeff McLean, acting associate professor at the University of Washington School of Dentistry. “This may be the first example of a parasitic long-term attachment between two different bacteria — where one species lives on the surface of another species gaining essential nutrients and then decides to thank its host by attacking it.”
To prove that TM7x needs XH001 to grow and survive, the team attempted to mix isolated TM7x cells with other strains of bacteria. Only XH001 was able to establish a physical association with TM7x, which led researchers to believe that TM7x and XH001 might have evolved together during their establishment in the mouth.
What makes TM7x even more intriguing are its potential roles in chronic inflammation of the digestive tract, vaginal diseases and periodontitis. The co-cultures collected in this study allowed researchers to examine, for the first time ever, the degree to which TM7x helps cause these conditions.
“Uncultivable bacteria presents a fascinating ‘final frontier’ for dental microbiologists and are a high priority for the NIDCR research portfolio,” said Dr. R. Dwayne Lunsford, director of the National Institute of Dental and Craniofacial Research’s microbiology program. “This study provides a near-perfect case of how co-cultivation strategies and a thorough appreciation for interspecies signaling can facilitate the recovery of these elusive organisms. Although culture-independent studies can give us a snapshot of microbial diversity at a particular site, in order to truly understand physiology and virulence of an isolate, we must ultimately be able to grow and manipulate these bacteria in the lab.”
It was previously known that XH001 induces inflammation. But by infecting bone marrow cells with XH001 alone and then with the TM7x/XH001 co-culture, the researchers also found that inflammation was greatly reduced when TM7x was physically attached to XH001. This is the only known study that has provided evidence of this relationship between TM7 and XH001.
The researchers plan to further study the unique relationship between TM7X and XH001 and how they jointly cause mucosal disease. Their findings could have implications for potential treatment and therapeutics.
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Solar energy that doesn’t block the view
December 24th, 2014By University of Michigan.
A team of researchers at Michigan State University has developed a new type of solar concentrator that when placed over a window creates solar energy while allowing people to actually see through the window.
It is called a transparent luminescent solar concentrator and can be used on buildings, cell phones and any other device that has a clear surface.
And, according to Richard Lunt of MSU’s College of Engineering, the key word is “transparent.”
Solar power with a view: MSU doctoral student Yimu Zhao holds up a transparent luminescent solar concentrator module.
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Photo by Yimu Zhao.
Research in the production of energy from solar cells placed around luminescent plastic-like materials is not new. These past efforts, however, have yielded poor results – the energy production was inefficient and the materials were highly colored.
“No one wants to sit behind colored glass,” said Lunt, an assistant professor of chemical engineering andmaterials science. “It makes for a very colorful environment, like working in a disco. We take an approach where we actually make the luminescent active layer itself transparent.”
The solar harvesting system uses small organic molecules developed by Lunt and his team to absorb specific nonvisible wavelengths of sunlight.
“We can tune these materials to pick up just the ultraviolet and the near infrared wavelengths that then ‘glow’ at another wavelength in the infrared,” he said.
The “glowing” infrared light is guided to the edge of the plastic where it is converted to electricity by thin strips of photovoltaic solar cells.
A transparent luminescent solar concentrator waveguide is shown with colorful traditional luminescent solar concentrators in the background. The new LSC can create solar energy but is not visible on windows or other clear surfaces.
Photo by G.L. Kohuth
“Because the materials do not absorb or emit light in the visible spectrum, they look exceptionally transparent to the human eye,” Lunt said.
One of the benefits of this new development is its flexibility. While the technology is at an early stage, it has the potential to be scaled to commercial or industrial applications with an affordable cost.
“It opens a lot of area to deploy solar energy in a non-intrusive way,” Lunt said. “It can be used on tall buildingswith lots of windows or any kind of mobile device that demands high aesthetic quality like a phone or e-reader. Ultimately we want to make solar harvesting surfaces that you do not even know are there.”
Lunt said more work is needed in order to improve its energy-producing efficiency. Currently it is able to produce a solar conversion efficiency close to 1 percent, but noted they aim to reach efficiencies beyond 5 percent when fully optimized. The best colored LSC has an efficiency of around 7 percent.
The research was featured on the cover of a recent issue of the journal Advanced Optical Materials.
Other members of the research team include Yimu Zhao, an MSU doctoral student in chemical engineering and materials science; Benjamin Levine, assistant professor of chemistry; and Garrett Meek, doctoral student in chemistry.
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Ancient, underground hydrogen-rich waters found around the world
December 19th, 2014
By Alton Parrish.
A team of scientists, led by the University of Toronto’s Barbara Sherwood Lollar, has mapped the location of hydrogen-rich waters found trapped kilometres beneath Earth’s surface in rock fractures in Canada, South Africa and Scandinavia.
Credit: G. Borgonie, 2014
The study, to be published in Nature on December 18, includes data from 19 different mine sites that wereexplored by Sherwood Lollar, a geoscientist at U of T’s Department of Earth Sciences, U of T senior research associate Georges Lacrampe-Couloume, and colleagues at Oxford and Princeton universities.
The scientists also explain how two chemical reactions combine to produce substantial quantities of hydrogen, doubling estimates of global production from these processes which had previously been based only on hydrogen coming out of the ocean floor.
“This represents a quantum change in our understanding of the total volume of Earth’s crust that may be habitable,” said Sherwood Lollar.
“Until now, none of the estimates of global hydrogen production sustaining deep microbial populations had included a contribution from the ancient continents. Since Precambrian rocks make up more than 70 per cent of the surface of Earth’s crust, Sherwood Lollar likens these terrains to a “sleeping giant”, a huge area that has now been discovered to be a source of possible energy for life,” she said.
One process, known as radiolytic decomposition of water, involves water undergoing a breakdown into hydrogen when exposed to radiation. The other is a chemical reaction called serpentization, a mineral alteration reaction that is common in such ancient rocks.
This study has important implications for the search for deep microbial life. Quantifying the global hydrogen budget is key to understanding the amount of the Earth’s biomass that is in the subsurface, as many deep ecosystems contain chemolithotrophic – so-called “rock-eating” – organisms that consume hydrogen.
Further, because Mars – like the Precambrian crust – consists of billions-of-year-old rocks with hydrogen-producing potential, this finding has ramifications for astrobiology. “If the ancient rocks of Earth are producing this much hydrogen, it may be that similar processes are taking place on Mars,” said Sherwood Lollar.
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Two stars merging into a super-massive star seen by astronomers
December 9th, 2014
By Alton Parrish.
A study of “MY Camelopardalis” binary system, published in the journal Astronomy & Astrophysics, shows that the most massive stars are made up by merging with other smaller stars, as predicted by theoretical models.
Most of the stars in our galaxy have been formed in binary or multiple systems, some of which are “eclipsing”, this is consists of two or more stars which, observed from Earth, undergo eclipses and mutual transitsbecause of their orbital plane facing our planet. One such system is the eclipsing binary MY Camelopardalis (MY Cam).
Artistic rendering of MY Cam system. The proportions between the components reflect the analysis results. The stars are deformed by its very fast rotation and the gravitational pull of the companion.
Credit: Javier Lorenzo (Universidad de Alicante).
The journal Astronomy & Astrophysics has published an article on MY Cam, one of the most massive star known, with the results of observations from the Calar Alto Observatory (Almería) signed by astronomers at the University of Alicante, the Astrobiology Centre of the Spanish National Research Council (CAB-CSIC) and the Canaries’ Astrophysics Institute (IAC), along with amateur astronomers.
This article concludes that MY Cam is the most massive binary star observed and its components, two stars of spectral type O (blue, very hot and bright), 38 and 32 times the Sun’s mass, are still on the main sequenceand are very close to each other, with an orbital period of less than 1.2 days, in other words, the shortestorbital period in this type of stars. This indicates that the binary was virtually formed as it is now: the stars were almost in contact at the time they were formed.
The expected development is the merger of both components into a single object over 60 solar masses before any of them have time to evolve significantly. Hence, these results demonstrate the viability of some theoretical models suggesting that most massive stars are formed by merging less massive stars.
Massive binary systems
Stars which, like the Sun, move alone in the Galaxy by trailing only their planetary system are a minority. Most stars spend their lives tied by gravity to a companion star (forming what is called a binary system) or several (what was known as multiple system). As explained by Javier Lorenzo, from the University of Alicante and first author of article, in these systems all stars describe their orbits around a common centre of mass.
In particular, the stars much more massive than the Sun contain an equivalent mass to many suns and tend to always appear in company. Recent studies suggest that these high-mass stars, that are much larger and hotter than the Sun, form part of systems with at least one other companion of comparable mass.
A particularly striking example is the binary system known as MY Camelopardalis (MY Cam), in the constellation of the Giraffe. This object is the brightest star in the open cluster “Alicante 1”, which was recently identified as a small stellar nursery by researchers at the University of Alicante.
Although it has been known for over fifty years that MY Cam is a high-mass star, it was only ten years ago that it was recognised as an eclipsing binary, a system in which one star passes in front of the other every time they complete their orbit, leading to changes in the brightness of the system that we perceive from Earth. This property of eclipsing binaries allows us to know many of the characteristics of the component stars through a careful study of the light that comes from them and the simple application of Newton’s law of universal gravitation.
For the study of MY Cam, professional astrophysicists obtained a large number of spectra of the system with FOCES spectrograph, which operated for many years in the 2.2 m telescope of Calar Alto Observatory. Using the Doppler Effect, these spectra allow us to measure the velocities with which the stars move in their orbits. Also, astrophysicists can determine the fundamental properties of stars, as their surface temperature and its size through a comprehensive analysis of the characteristics of the spectra.
To complete the work, they had the help of amateur astronomers who measured the changes in the amount of light coming from the system along the orbit, what astrophysicists call the light curve of the system. Analysis of these data has shown that MY Cam is a truly exceptional system.
The light curve- as explained by Sergio Simon, IAC researcher and one of the authors of the article – shows that the orbital period of the system is only 1.2 days. Given the large size of the stars, they have to be extremely close to be able to do a full turn so quickly. The stars are moving at a speed of over one million km/h, but being so close, the tidal forces between them make them rotate about themselves with the same period, ie, each star turns on itself in just over a day, while the Sun, which is much smaller, turns on itself once every 26 days. Stars are like giant spinning tops and every point of the surface moves with a speed of over one million km/h. Each has a radius around 700 times bigger than the Earth’s, but turns on itself at about the same time.
But also, the stars are extremely massive. Their masses are 38 and 32 times the Sun’s mass. Such huge stars do not fit so easily into such a small orbit and the conclusion of the study is that they are actually in touch and the material of their outer layers is mixing, giving place to a common envelope (what is known as a contact binary). MY Cam is one of the most massive contact binaries known and by far the most massive whose components are so young they have not yet begun to evolve.
As stated by Ignacio Negueruela, another author from the University of Alicante, this is the most interesting aspect of MY Cam since its foreseeable future confirms some of the current theories of formation of extremely massive stars. The properties of the two components of MY Cam suggest that they are extremely young stars formed in the past two million years. This extreme youth allows us to suspect that the system was formed essentially as it is now, although perhaps the two stars were not touching initially.
As they get older, their natural evolution is to become larger. Given that they have no clearance between them, this process will lead to the merger of the two stars in a single object, a real star mastodon. The details of the merger process are not known, because it has never been seen before. Some theoretical models suggest that the merger process is extremely fast, releasing a huge amount of energy in a kind of explosion.
Other studies favor a less violent process, but in any event spectacular. Anyway, many astrophysicists believe that the merger of the components of a close binary is probably the most effective way to generate extremely massive stars. MY Cam is the first example of a system that can lead to one of these objects.
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The riddle of the missing stars
December 4th, 2014
By ESA.
Thanks to the NASA/ESA Hubble Space Telescope, some of the most mysterious cosmic residents have just become even more puzzling.
This NASA/ESA Hubble Space Telescope image shows four globular clusters in the dwarf galaxy Fornax.
Credit: NASA, ESA, S. Larsen (Radboud University, the Netherlands)
New observations of globular clusters in a small galaxy show they are very similar to those found in the Milky Way, and so must have formed in a similar way. One of the leading theories on how these clusters form predicts that globular clusters should only be found nestled in among large quantities of old stars. But these old stars, though rife in the Milky Way, are not present in this small galaxy, and so, the mystery deepens.
Globular clusters — large balls of stars that orbit the centres of galaxies, but can lie very far from them — remain one of the biggest cosmic mysteries. They were once thought to consist of a single population of stars that all formed together. However, research has since shown that many of the Milky Way’s globular clusters had far more complex formation histories and are made up of at least two distinct populations of stars.
Of these populations, around half the stars are a single generation of normal stars that were thought to form first, and the other half form a second generation of stars, which are polluted with different chemical elements. In particular, the polluted stars contain up to 50-100 times more nitrogen than the first generation of stars.
The proportion of polluted stars found in the Milky Way’s globular clusters is much higher than astronomers expected, suggesting that a large chunk of the first generation star population is missing. A leading explanation for this is that the clusters once contained many more stars but a large fraction of the first generation stars were ejected from the cluster at some time in its past.
This explanation makes sense for globular clusters in the Milky Way, where the ejected stars could easily hide among the many similar, old stars in the vast halo, but the new observations, which look at this type of cluster in a much smaller galaxy, call this theory into question.
Astronomers used Hubble’s Wide Field Camera 3 (WFC3) to observe four globular clusters in a small nearby galaxy known as the Fornax Dwarf Spheroidal galaxy [1].
“We knew that the Milky Way’s clusters were more complex than was originally thought, and there are theories to explain why. But to really test our theories about how these clusters form we needed to know what happened in other environments,” says Søren Larsen of Radboud University in Nijmegen, the Netherlands, lead author of the new paper. “Before now we didn’t know whether globular clusters in smaller galaxies had multiple generations or not, but our observations show clearly that they do!”
The astronomers’ detailed observations of the four Fornax clusters show that they also contain a second polluted population of stars [2] and indicate that not only did they form in a similar way to one another, their formation process is also similar to clusters in the Milky Way. Specifically, the astronomers used the Hubble observations to measure the amount of nitrogen in the cluster stars, and found that about half of the stars in each cluster are polluted at the same level that is seen in Milky Way’s globular clusters.
This high proportion of polluted second generation stars means that the Fornax globular clusters’ formation should be covered by the same theory as those in the Milky Way.
Based on the number of polluted stars in these clusters they would have to have been up to ten times more massive in the past, before kicking out huge numbers of their first generation stars and reducing to their current size. But, unlike the Milky Way, the galaxy that hosts these clusters doesn’t have enough old stars to account for the huge number that were supposedly banished from the clusters.
“If these kicked-out stars were there, we would see them — but we don’t!” explains Frank Grundahl of Aarhus University in Denmark, co-author on the paper. “Our leading formation theory just can’t be right. There’s nowhere that Fornax could have hidden these ejected stars, so it appears that the clusters couldn’t have been so much larger in the past.”
This finding means that a leading theory on how these mixed generation globular clusters formed cannot be correct and astronomers will have to think once more about how these mysterious objects, in the Milky Way and further afield, came to exist.
The new work is detailed in a paper published today, 20 November 2014, in The Astrophysical Journal.
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Wireless electronic implants stop staph, then harmlessly dissolve
December 4th, 2014
By Alton Parrish.
Researchers at Tufts University, in collaboration with a team at the University of Illinois at Champaign-Urbana, have demonstrated a resorbable electronic implant that eliminated bacterial infection in mice by delivering heat to infected tissue when triggered by a remote wireless signal. The silk and magnesium devices then harmlessly dissolved in the test animals. The technique had previously been demonstrated only in vitro.
Credit: Tufts University
The research is published online in the Proceedings of the National Academy of Sciences Early Edition the week of November 24-28, 2014.
“This is an important demonstration step forward for the development of on-demand medical devices that can be turned on remotely to perform a therapeutic function in a patient and then safely disappear after their use, requiring no retrieval,” said senior author Fiorenzo Omenetto, professor of biomedical engineering and Frank C. Doble professor at Tufts School of Engineering. “These wireless strategies could help manage post-surgical infection, for example, or pave the way for eventual ‘wi-fi’ drug delivery.”
Optical (and corresponding IR) images of the dissolution of implant device (top row: powering induction coil with resistor/heater)
Credit: Tufts University
Implantable medical devices typically use non-degradable materials that have limited operational lifetimes and must eventually be removed or replaced. The new wireless therapy devices are robust enough to survive mechanical handling during surgery but designed to harmlessly dissolve within minutes or weeks depending on how the silk protein was processed, noted the paper’s first author, Hu Tao, Ph.D., a former Tufts post-doctoral associate who is now on the faculty of the Shanghai Institute of Microsystem and Information Technology, Chinese Academy of Sciences.
Each fully dissolvable wireless heating device consisted of a serpentine resistor and a power-receiving coil made of magnesium deposited onto a silk protein layer. The magnesium heater was encapsulated in a silk “pocket” that protected the electronics and controlled its dissolution time.
Devices were implanted in vivo in S. aureus infected tissue and activated by a wireless transmitter for two sets of 10-minute heat treatments. Tissue collected from the mice 24 hours after treatment showed no sign of infection, and surrounding tissues were found to be normal. Devices completely dissolved after 15 days, and magnesium levels at the implant site and surrounding areas were comparable to levels typically found in the body.
The researchers also conducted in vitro experiments in which similar remotely controlled devices released the antibiotic ampicillin to kill E. coli and S. aureus bacteria. The wireless activation of the devices was found to enhance antibiotic release without reducing antibiotic activity.
Omenetto holds an adjunct appointment in the Department of Physics in the School of Arts and Sciences at Tufts as well as appointments in the Departments of Biomedical Engineering and Chemical and Biological Engineering in the School of Engineering.
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Study shows Marijuana’s long-term effects on the brain
November 26th, 2014
By Alton Parrish.
The effects of chronic marijuana use on the brain may depend on age of first use and duration of use, according to researchers at the Center for BrainHealth at The University of Texas at Dallas.
Credit: Vanderbilt University
In a paper published today in Proceedings of the National Academy of Sciences (PNAS), researchers for the first time comprehensively describe existing abnormalities in brain function and structure of long-term marijuana users with multiple magnetic resonance imaging (MRI) techniques. Findings show chronic marijuana users have smaller brain volume in the orbitofrontal cortex (OFC), a part of the brain commonly associated with addiction, but also increased brain connectivity.
“We have seen a steady increase in the incidence of marijuana use since 2007,“said Dr. Francesca Filbey, Associate Professor in the School of Behavioral and Brain Sciences at the University of Texas at Dallas and Director of the Cognitive Neuroscience Research in Addictive Disorders at the Center for BrainHealth. “However, research on its long-term effects remains scarce despite the changes in legislation surrounding marijuana and the continuing conversation surrounding this relevant public health topic.”
The research team studied 48 adult marijuana users and 62 gender- and age-matched non-users, accounting for potential biases such as gender, age and ethnicity. The authors also controlled for tobacco and alcohol use. On average, the marijuana users who participated in the study consumed the drug three times per day. Cognitive tests show that chronic marijuana users had lower IQ compared to age-and gender-matched controls but the differences do not seem to be related to the brain abnormalities as no direct correlation can be drawn between IQ deficits and OFC volume decrease.
“What’s unique about this work is that it combines three different MRI techniques to evaluate different brain characteristics,” said Dr. Sina Aslan, founder and president of Advance MRI, LLC and adjunct assistant professor at The University of Texas at Dallas. “The results suggest increases in connectivity, both structural and functional that may be compensating for gray matter losses. Eventually, however, the structural connectivity or ‘wiring’ of the brain starts degrading with prolonged marijuana use.”
Tests reveal that earlier onset of regular marijuana use induces greater structural and functional connectivity. Greatest increases in connectivity appear as an individual begins using marijuana. Findings show severity of use is directly correlated to greater connectivity.
Although increased structural wiring declines after six to eight years of continued chronic use, marijuana users continue to display more intense connectivity than healthy non-users, which may explain why chronic, long-term users “seem to be doing just fine” despite smaller OFC brain volumes, Filbey explained.
“To date, existing studies on the long-term effects of marijuana on brain structures have been largely inconclusive due to limitations in methodologies,” said Dr. Filbey. “While our study does not conclusively address whether any or all of the brain changes are a direct consequence of marijuana use, these effects do suggest that these changes are related to age of onset and duration of use.”
The study offers a preliminary indication that gray matter in the OFC may be more vulnerable than white matter to the effects of delta-9-tetrahydrocannabinol (THC), the main psychoactive ingredient in the cannabis plant. According to the authors, the study provides evidence that chronic marijuana use initiates a complex process that allows neurons to adapt and compensate for smaller gray matter volume, but further studies are needed to determine whether these changes revert back to normal with discontinued marijuana use, whether similar effects are present in occasional marijuana users versus chronic users and whether these effects are indeed a direct result of marijuana use or a predisposing factor.
The research was funded by the National Institute on Drug Abuse to Dr. Filbey (R01 DA030344, K01 DA021632).
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Fabricating open-source baby robots
November 26th, 2014By ERC.
European Research Council (ERC) grantee Dr Pierre-Yves Oudeyer, is today presenting the first complete open-source 3D printed humanoid robot, called ‘Poppy’ (@poppy_project). Poppy is a robot that anybody can build – its body is 3D printed and its behaviour programmed by the user.
© Inria/ Photo H. Raguet
However, it is not just a tool for scientists and computer “geeks” – the team of developers aims to use the robot as part of vocational training in schools, giving students the opportunity to experiment and program 3D printed robots with various characteristics.
Poppy was developed in France by Inria’s Flowers team, which creates computer and robotic models as tools for understanding developmental processes in humans.
Dr Pierre-Yves Oudeyer, who holds an ERC Starting Grant in Computer Science and Informatics, comments: “The advances offered by 3D printing have already revolutionised design and industry. However, only very little has been done to explore the benefits of 3D printing and its interaction with computer science in classrooms. With our Poppy platform, we are now offering schools and teachers an adequate tool to cultivate the creativity of students studying in fields such as mechanics, computer sciences, electronics and 3D printing”.
Build your own robot
Poppy’s body is 3D printed and its behaviour determined with freely available software, meaning users can design body parts quickly and easily, and program their robot’s behaviour themselves. Dr Oudeyer clarifies: “Both hardware and software are open source. There is not one single Poppy humanoid robot but as many as there are users. This makes it very attractive as it has grown from a purely technological tool to a real social platform”.
Accessible hardware and software make it easy for users to experiment with building their own robots for the first time. Poppy is now also compatible with the Arduino platform, which allows the robot to interface with other electronic devices, including smart clothing, lights, sensors and musical instruments.
Do It Yourself in schools
Dr Oudeyer, who is a Research Director at Inria, plans to extend use of this technology beyond research labs, to the educational sector in particular. Commenting on the Poppy initiative, EU Commissioner for Research, Innovation and Science Máire Geoghegan-Quinn said: “This is a great offshoot of an ERC project: a low-cost platform that could foster a more interactive and inspiring learning environment, allowing students to connect with research and design.”
The Poppy platform has come about thanks to the ERC-funded “Explorers” project, in which Dr Oudeyer studies the mechanisms of learning and development using robots. “Our hypothesis is that the body is an essential variable in the acquisition of motor and social skills in humans. To study this theory, we needed to create a platform allowing fast experimentation of new robot morphologies. This led to the Poppy platform”.
Talking about the benefits of his ERC-funded research, Dr Oudeyer highlights: “My ERC grant was essential in developing problem-solving and critical thinking ability in robotics. I would now be glad if students who need more education in computer science, coding and design, could train using Poppy and perhaps, later, be able to find a job in the robotics sector”.
Gathering across frontiers
Poppy will also allow users to share their ideas and results in a very open and collaborative way through a dedicated web platform – gathering people across the frontiers of school, art, science and industry.
Dr Oudeyer’s team has already used Poppy in other fields, including the arts. In an ongoing artist residence programme entitled “Etres et Numériques”, the team worked with a dancer and a visual artist to explore the emotions and perceptions of body gestures and movements using the robot (see more here). They expect to extend these experiments to other artistic performances.
In his recent TEDxCannes talk, Dr Oudeyer explained how open-source baby robots can help scientists, and society at large, better understand the human mysteries of learning, curiosity and language acquisition.
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Alma examines Ezekiel like ‘Wheel, in a wheel’ of dust and gas
November 15th, 2014By Alton Parrish.
A research group led by Anne Dutrey from the Laboratory of Astrophysics of Bordeaux, France, and the National Centre for Scientific Research (CNRS) observed the distribution of dust and gas in a binary starsystem called GG Tau-A. It was recently discovered that one of GG Tau-A’s components is itself a double star. This object is only a few million years old and lies approximately 460 light-years from Earth in the constellation Taurus.
This artist’s impression shows the dust and gas around the double star system GG Tauri-A. Researchers using ALMA have detected gas in the region between two discs in this binary system. This may allow planets to form in the gravitationally perturbed environment of the binary. Half of Sun-like stars are born in binarysystems, meaning that these findings will have major consequences for the hunt for exoplanets.
Credit: Credit: ESO/L.CalçadaLike a wheel in a wheel, GG Tau-A contains a large, outer disk encircling the entire system as well as an inner disk around the main central star. This second inner disk has a mass roughly equivalent to that of Jupiter. Its presence has been an intriguing mystery for astronomers since it is losing material to its central star at a rate that should have depleted it long ago.While observing these structures with ALMA, the team made the exciting discovery of gas clumps in the region between the two disks. The new observations suggest that material is being transferred from the outer to the inner disk, creating a sustaining lifeline between the two.
“Material flowing through the cavity was predicted by computer simulations but never imaged before. Detecting these clumps indicates that material is moving between the disks, allowing one to feed off the other,” explains Dutrey. “These observations demonstrate that material from the outer disk can sustain the inner disk for a long time. This has major consequences for potential planet formation.”
Planets are born from the material left over from star birth. This is a slow process, meaning that an enduring disk is needed for planet formation. If this same feeding process occurs in other multiple-star systems, these observations may explain the frequency with which planets have been and continue to be discovered in binarysystems.
“We may be witnessing these types of exoplanetary systems in the midst of formation,” said Jeffrey Bary, an astronomer at Colgate University in Hamilton, N.Y., and co-author of the paper. “In a sense, we are learning why these seemingly strange systems exist.”
The first phase of exoplanet searches was directed at single host-stars like the Sun, more recently it has been shown that a large fraction of giant planets orbit binary star systems. Now, researchers have begun to take an even closer look and investigate the possibility of planets orbiting individual stars of multiple-star systems. The new discovery supports the possible existence of such planets, marking a new era in the hunt for exoplanets.
“This means that multiple star systems have a way to form planets, despite their complicated dynamics. Given that we continue to find interesting planetary systems, our observations provide a glimpse of the mechanisms that enable such systems to form,” concludes Bary.
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New challenge for direct imaging of two-earths
November 5th, 2014By Alton Parrish.
Bright exozodiacal light, created by the glowing grains of hot exozodiacal dust, or the reflection of starlight off these grains, was observed around nine of the targeted stars.
This artist’s view from an imagined planet around a nearby star shows the brilliant glow of exozodiacal light extending up into the sky and swamping the Milky Way. This light is starlight reflected from hot dust created as the result of collisions between asteroids, and the evaporation of comets. The presence of such thick dust clouds in the inner regions around some stars may pose an obstacle to the direct imaging of Earth-like planets in the future.
Credit: ESO/L. Calçada
From dark clear sites on Earth, zodiacal light looks like a faint diffuse white glow seen in the night sky after the end of twilight, or before dawn. It is created by sunlight reflected off tiny particles and appears to extend up from the vicinity of the Sun. This reflected light is not just observed from Earth but can be observed from everywhere in the Solar System.
The glow being observed in this new study is a much more extreme version of the same phenomenon. While this exozodiacal light — zodiacal light around other star systems — had been previously detected, this is the first large systematic study of this phenomenon around nearby stars.
In contrast to earlier observations the team did not observe dust that will later form into planets, but dust created in collisions between small planets of a few kilometres in size — objects called planetesimals that are similar to the asteroids and comets of the Solar System. Dust of this kind is also the origin of the zodiacal light in the Solar System.
“If we want to study the evolution of Earth-like planets close to the habitable zone, we need to observe the zodiacal dust in this region around other stars,” said Steve Ertel, lead author of the paper, from ESO and the University of Grenoble in France. “Detecting and characterising this kind of dust around other stars is a way to study the architecture and evolution of planetary systems.”
Detecting faint dust close to the dazzling central star requires high resolution observations with high contrast. Interferometry — combining light collected at the exact same time at several different telescopes — performed in infrared light is, so far, the only technique that allows this kind of system to be discovered and studied.
By using the power of the VLTI and pushing the instrument to its limits in terms of accuracy and efficiency, the team was able to reach a performance level about ten times better than other available instruments in the world.
For each of the stars the team used the 1.8-metre Auxiliary Telescopes to feed light to the VLTI. Where strong exozodical light was present they were able to fully resolve the extended discs of dust, and separate their faint glow from the dominant light of the star.
By analysing the properties of the stars surrounded by a disc of exozodiacal dust, the team found that most of the dust was detected around older stars. This result was very surprising and raises some questions for our understanding of planetary systems. Any known dust production caused by collisions of planetesimals should diminish over time, as the number of planetesimals is reduced as they are destroyed.
The sample of observed objects also included 14 stars for which the detection of exoplanets has been reported. All of these planets are in the same region of the system as the dust in the systems showing exozodiacal light. The presence of exozodiacal light in systems with planets may create a problem for further astronomical studies of exoplanets.
Exozodiacal dust emission, even at low levels, makes it significantly harder to detect Earth-like planets with direct imaging. The exozodiacal light detected in this survey is a factor of 1000 times brighter than the zodiacal light seen around the Sun. The number of stars containing zodiacal light at the level of the Solar System is most likely much higher than the numbers found in the survey. These observations are therefore only a first step towards more detailed studies of exozodiacal light.
“The high detection rate found at this bright level suggests that there must be a significant number of systems containing fainter dust, undetectable in our survey, but still much brighter than the Solar System’s zodiacal dust,” explains Olivier Absil, co-author of the paper, from the University of Liège. “The presence of such dust in so many systems could therefore become an obstacle for future observations, which aim to make direct images of Earth-like exoplanets.”
The team used the VLTI visitor instrument PIONIER, which is able to interferometrically connect all four Auxiliary Telescopes or all four Unit Telescopes of the VLT at the Paranal Observatory. This led to not only extremely high resolution of the targets but also allowed for a high observing efficiency.
Previous observations were made with the CHARA array — an optical astronomical interferometer operated by the Center for High Angular Resolution Astronomy (CHARA) of the Georgia State University, and its fibred beam combiner FLUOR.
As a by-product, these observations have also led to the discovery of new, unexpected stellar companions orbiting around some of the most massive stars in the sample. “These new companions suggest that we should revise our current understanding of how many of this type of star are actually double,” says Lindsay Marion, lead author of an additional paper dedicated to this complementary work using the same data.
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1 million could live in the Ziggurat pyramid
November 4th, 2014By Alton Parrish.
The “Ziggurat” is named after the temple towers of the ancient Mesopotamian valley, a terraced pyramid structure with successively receding stories. It will be a carbon-neutral structure.
According to the International Institute for the Urban Environment, the technologies incorporated into the Ziggurat project will make it a viable metropolis. Timelinks has already patented the design and technology used in this project.
A horizontal and vertical integrated 360 degree network will be the mode of transportation in this city of the future, making cars redundant. Facial recognition technology for security purposes is another interesting feature that is going to be incorporated in Ziggurat Project.
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Synthetic Molecule Makes Cancer Self-Destruct
October 30th, 2014By University of Texas.
Researchers from The University of Texas at Austin and five other institutions have created a molecule that can cause cancer cells to self-destruct by ferrying sodium and chloride ions into the cancer cells.
These synthetic ion transporters, described this week in the journal Nature Chemistry, confirm a two-decades-old hypothesis that could point the way to new anticancer drugs while also benefitting patients with cystic fibrosis.
Synthetic ion transporters can induce apoptosis by facilitating chloride anion transport into cells.
Credit: University of Texas at Austin
Synthetic ion transporters have been created before, but this is the first time researchers have shown them working in a real biological system where transported ions demonstrably cause cells to self-destruct.
Cells in the human body work hard to maintain a stable concentration of ions inside their cell membranes. Disruption of this delicate balance can trigger cells to go through apoptosis, known as programmed cell death, a mechanism the body uses to rid itself of damaged or dangerous cells.
One way of destroying cancer cells would be to trigger this innate self-destruct sequence by skewing the ion balance in cells. Unfortunately, when a cell becomes cancerous, it changes the way it transports ions across its cell membrane in a way that blocks apoptosis.
Almost two decades ago, a natural substance called prodigiosin was discovered that acted as a natural ion transporter and has an anticancer effect.
Since then, it has been a “chemist’s dream,” said Jonathan Sessler, professor in The University of Texas at Austin’s College of Natural Sciences and co-author of the study, to find “synthetic transporters that might be able to do exactly the same job, but better, and also work for treating diseases such as cystic fibrosis where chloride channels don’t work.”
Sessler and his collaborators, led by professors Injae Shin of Yonsei University and Philip A. Gale of the University of Southampton and King Abdulaziz University, were able to bring this dream to fruition.
The University of Texas members of the team created a synthetic ion transporter that binds to chloride ions. The molecule works by essentially surrounding the chloride ion in an organic blanket, allowing the ion to dissolve in the cell’s membrane, which is composed largely of lipids, or fats. The researchers found that the transporter tends to use the sodium channels that naturally occur in the cell’s membrane, bringing sodium ions along for the ride.
Gale and his team found that the ion transporters were effective in a model system using artificial lipid membranes.
Shin and his working group were then able to show that these molecules promote cell death in cultured human cancer cells. One of the key findings was that the cancer cell’s ion concentrations changed before apoptosis was triggered, rather than as a side effect of the cell’s death.
“We have thus closed the loop and shown that this mechanism of chloride influx into the cell by a synthetic transporter does indeed trigger apoptosis,” said Sessler. “This is exciting because it points the way towards a new approach to anticancer drug development.”
Sessler noted that right now, their synthetic molecule triggers programmed cell death in both cancerous and healthy cells. To be useful in treating cancer, a version of a chloride anion transporter will have to be developed that binds only to cancerous cells. This could be done by linking the transporter in question to a site-directing molecule, such as the texaphyrin molecules that Sessler’s lab has previously synthesized.
The results were a culmination of many years of work across three continents and six universities.
“We have demonstrated that this mechanism is viable, that this idea that’s been around for over two decades is scientifically valid, and that’s exciting,” said Sessler. “We were able to show sodium is really going in, chloride is really going in. There is now, I think, very little ambiguity as to the validity of this two-decades-old hypothesis.
The next step for the researchers will be to take the synthetic ion transporters and test them in animal models.
Sessler’s co-authors are Sung-Kyun Ko (Yonsei University and Korea Research Institute of Bioscience and Biotechnology); Sung Kuk Kim, Andrew Share and Vincent Lynch (UT Austin); Jinhong Park and Wan Namkung (Yonsei University); Wim Van Rossom and Nathalie Busschaert (University of Southampton); Philip Gale (University of Southampton and King Abdulaziz University); and Injae Shin (Yonsei University). Sung-Kyun Ko and Sung Kuk Kim were the lead authors on this study. Sessler, Gale and Shin were the corresponding authors.
This work was supported by the National Creative Research Initiative program in South Korea; the Office of Basic Energy Sciences in the U.S. Department of Energy; and the Chemical Biology Research Center in the Korea Research Institute of Bioscience and Biotechnology.
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Egyptian Mummification Started 1500 Years Earlier Than Thought
October 30th, 2014
By Alton Parrish.
An Egyptian mummy kept in the Vatican Museums
Credit; Wikipedia
The scientific findings of an 11-year study by a researcher in the Department of Archaeology at York, and York’s BioArCh facility, and an Egyptologist from the Department of Ancient History at Macquarie University, push back the origins of a central and vital facet of ancient Egyptian culture by over a millennium.
Traditional theories on ancient Egyptian mummification suggest that in prehistory — the Late Neolithic and Predynastic periods between c. 4500 and 3100 B.C. — bodies were desiccated naturally through the action of the hot, dry desert sand.
Scientific evidence for the early use of resins in artificial mummification has, until now, been limited to isolated occurrences during the late Old Kingdom (c. 2200 BC). Their use became more apparent during the Middle Kingdom (c. 2000-1600 BC).
But the York, Macquarie and Oxford team identified the presence of complex embalming agents in linen wrappings from bodies in securely provenanced tombs in one of the earliest recorded ancient Egyptian cemeteries at Mostagedda, in the region of Upper Egypt.
“For over a decade I have been intrigued by early and cryptic reports of the methods of wrapping bodies at the Neolithic cemeteries at Badari and Mostagedda,” said Dr Jana Jones of Macquarie University, Sydney.
“In 2002, I examined samples of funerary textiles from these sites that had been sent to various museums in the United Kingdom through the 1930s from Egypt. Microscopic analysis with my colleague Mr Ron Oldfield revealed resins were likely to have been used, but I wasn’t able to confirm my theories, or their full significance, without tapping into my York colleague’s unique knowledge of ancient organic compounds.”
Dr Jones initiated the research and led the study jointly with Dr Stephen Buckley, a Research Fellow at the University of York.
“Such controversial inferences challenge traditional beliefs on the beginnings of mummification,” said Dr Jones. “They could only be proven conclusively through biochemical analysis, which Dr Buckley agreed to undertake after a number of aborted attempts by others. His knowledge includes many organic compounds present in an archaeological context, yet which are often not in the literature or mass spectra libraries.”
Corresponding author on the article, Dr Buckley, used a combination of gas chromatography-mass spectrometry and sequential thermal desorption/pyrolysis to identify a pine resin, an aromatic plant extract, a plant gum/sugar, a natural petroleum source, and a plant oil/animal fat in the funerary wrappings.
Predating the earliest scientific evidence by more than a millennium, these embalming agents constitute complex, processed recipes of the same natural products, in similar proportions, as those employed at the zenith of Pharaonic mummification some 3,000 years later.
Dr Buckley, who designed the experimental research and conducted the chemical analyses, said: “The antibacterial properties of some of these ingredients and the localised soft-tissue preservation that they would have afforded lead us to conclude that these represent the very beginnings of experimentation that would evolve into the mummification practice of the Pharaonic period.”
Dr Buckley added: “Having previously led research on embalming agents employed in mummification during Egypt’s Pharaonic period it was notable that the relative abundances of the constituents are typical of those used in mummification throughout much of ancient Egypt’s 3000 year Pharaonic history. Moreover, these resinous recipes applied to the prehistoric linen wrapped bodies contained antibacterial agents, used in the same proportions employed by the Egyptian embalmers when their skill was at its peak, some 2500-3000 years later.”
Professor Thomas Higham, who was responsible for dating the burials at the University of Oxford, said: “This work demonstrates the huge potential of material in museum collections to allow researchers to unearth new information about the archaeological past. Using modern scientific tools our work has helped to illuminate a key aspect of the early history of ancient Egypt.”
“Our ground-breaking results show just what can be achieved through interdisciplinary collaboration between the sciences and the humanities,” said Dr Jones.
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