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AIXI: To create a super-intelligent machine, start with an equation

AIXI: To create a super-intelligent machine, start with an equation | Amazing Science | Scoop.it
Intelligence is a very difficult concept and, until recently, no one has succeeded in giving it a satisfactory formal definition.

 

Most researchers have given up grappling with the notion of intelligence in full generality, and instead focus on related but more limited concepts – but Marcus Hutter argues that mathematically defining intelligence is not only possible, but crucial to understanding and developing super-intelligent machines. From this, his research group has even successfully developed software that can learn to play computer games from scratch.

 

But first, how do we define "intelligence"? Hutter's group has sifted through the psychology, philosophy and artificial intelligence literature and searched for definitions individual researchers and groups came up with. The characterizations are very diverse, but there seems to be a recurrent theme which we have aggregated and distilled into the following definition: Intelligence is an agent's ability to achieve goals or succeed in a wide range of environments.

 

The emerging scientific field is called universal artificial intelligence, with AIXI being the resulting super-intelligent agent. AIXI has a planning component and a learning component. The goal of AIXI is to maximise its reward over its lifetime – that's the planning part.

 

In summary, every interaction cycle consists of observation, learning, prediction, planning, decision, action and reward, followed by the next cycle. If you're interested in exploring further, AIXI integrates numerous philosophical, computational and statistical principles:

 

  • Ockham's razor (simplicity) principle for model selection
  • Epicurus principle of multiple explanations as a justification of model averaging
  • Bayes rule for updating beliefs
  • Turing machines as universal description language
  • Kolmogorov complexity to quantify simplicity
  • Solomonoff's universal prior, and
  • Bellman equations for sequential decision making.

 

AIXI's algorithm rigorously and uniquely defines a super-intelligent agent that learns to act optimally in arbitrary unknown environments. One can prove amazing properties of this agent – in fact, one can prove that in a certain sense AIXI is the most intelligent system possible. Note that this is a rather coarse translation and aggregation of the mathematical theorems into words, but that is the essence.

 

Since AIXI is incomputable, it has to be approximated in practice. In recent years, we have developed various approximations, ranging from provably optimal to practically feasible algorithms.

 

The point is not that AIXI is able to play these games (they are not hard) – the remarkable fact is that a single agent can learn autonomously this wide variety of environments. AIXI is given no prior knowledge about these games; it is not even told the rules of the games! It starts as a blank canvas, and just by interacting with these environments, it figures out what is going on and learns how to behave well. This is the really impressive feature of AIXI and its main difference to most other projects.

 

Even though IBM Deep Blue plays better chess than human Grand Masters, it was specifically designed to do so and cannot play Jeopardy. Conversely, IBM Watson beats humans in Jeopardy but cannot play chess – not even TicTacToe or Pac-Man. AIXI is not tailored to any particular application. If you interface it with any problem, it will learn to act well and indeed optimally.

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The world’s oldest astronomers: Scientists use ancient trees to look back on the history of our local cosmos

The world’s oldest astronomers: Scientists use ancient trees to look back on the history of our local cosmos | Amazing Science | Scoop.it
Scientists in Japan use ancient trees to look back on the history of our local cosmos, and discover a mystery.

 

Since the invention of the telescope in the year 1608, mankind has collected information about our local cosmos. As it turns out, we’re not the only ones. Trees have been doing the same for millennia.

 

A group of physicists led by Nagoya University graduate student Fusa Miyake has begun using information stored in ancient Japanese cedars to gain the oldest firsthand accounts of the local universe. They have discovered, hidden within tree rings, clear evidence of some surprisingly high-energy events—possibly supernovae or solar flares—that occurred more than 1200 years ago.

 

On Japan’s Yakushima island, trees regularly live at least a thousand years, thriving under the tree equivalent of a low-carb diet in the form of a low-nutrition granite bedrock that encourages a slower pace of growth. Miyake and her team examined core samples from two trees on this small island. Back at Nagoya University, they studied the number and thickness of the tree’s rings not just to determine the age of the trees but also to gather information about the atmosphere they breathed.


When high-energy radiation from space enters Earth’s upper atmosphere, it interacts with naturally occurring atmospheric molecules to produce the isotope carbon-14. As trees are firmly plugged into the earth’s carbon cycle by photosynthesis, the carbon-14 ends up in each tree ring, creating an annual record etched into the flesh of the tree of the average carbon-14 level in Earth’s atmosphere.

 

Miyake and her colleagues had good reason to focus on the rings corresponding to 775 AD. A previous project called IntCal, which uses tree records of carbon-14 levels to calibrate carbon-14 dating, had seen a noticeable rise in carbon-14 levels toward the end of the 8th century.

The signal Miyake’s team found was far above anything seen in recent times, indicating that Earth had been bombarded by an extremely intense burst of radiation. The rings revealed that, over the course of one year, the atmospheric level of carbon-14 rose 1.2 percent: nearly 20 times the normal variation.

 

This massive flash of radiation could have been caused by a supernova; a gamma ray burst from a supremely rare galactic event such as a collision of two neutron stars; or a super solar flare at least 10 times the size of the largest observed flare.

 

Using their knowledge of earth sciences, biology and astronomy, Miyake’s team uncovered a smoking gun in a cosmological whodunit. Now all that remains is to identify who fired that gun.

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Abel Farias's curator insight, December 2, 2013 5:38 PM

You can find history in any object. Whenever archeologists look for new fossils they are looking for a something that tells them a story. In this article they talk about how tree rings explain how the environment was during the life of the tree. I would use this article in Chemistry class during the Carbon Dating unit. It shows how recent day scientist used carbon dating to make a new discovery

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Ultrasound pulses could replace daily injections for diabetics

Ultrasound pulses could replace daily injections for diabetics | Amazing Science | Scoop.it

There could be hope for diabetics who are tired of giving themselves insulin injections on a daily basis. Researchers at North Carolina State University and the University of North Carolina at Chapel Hill are developing a system in which a single injection of nanoparticles could deliver insulin internally for days at a time – with a little help from pulses of ultrasound.

 

The biocompatible and biodegradable nanoparticles are made of poly(lactic-co-glycolic acid), and contain a payload of insulin. Each particle has either a positively-charged chitosan coating, or a negatively-charged alginate coating. When the two types of particles are mixed together, these oppositely-charged coatings cause them to be drawn to each other by electrostatic force.

 

 


Via Ray and Terry's
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Joseph Perrone's comment, January 12, 2014 12:35 PM
Researchers in north Carolina are developing a way to help people with diabetes. so instead of giving insulin shots every day they are working on a way to use one shot and use that for days on end with the use of ultrasounds. This will make it much easier on the people who take the shots every single day. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .. . . . . . . . . .. . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . I really think that this will be very useful to the diabetics! sounds much better that giving yourself a shot everyday! Must be painful to do that stuff. Good artical!
Taylor Marie Price's comment, February 5, 2014 5:18 PM
UNC and NC State students are trying to develop a way for diabetics to receive their insulin without daily injections. The plan is for nanoparticles to carry a payload of insulin to last a few days...................................As a diabetic I think it is a great idea and would be absolutely AMAZING!!! Even though I'm currently on a insulin pump which allows less shots it would even better if I had something that worked in the way the nanoparticles would work so it would allow me to not have to worry about forgetting as often or having to stress about giving my insulin to myself.
Madison Punch's comment, April 13, 2014 2:36 PM
It's so cool to know that in my home state, students are trying to improve treatment mediums for diabetics. It's a tough thing to deal with and to control and it's rad that more ways to accommodate the disease.
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Ash on the fire: Why do dying stars accumulate iron?

Ash on the fire: Why do dying stars accumulate iron? | Amazing Science | Scoop.it

Every now and again a physicist finds themselves in front of a camera and, either through over-enthusiasm or poor editing, is heard to say something that is “less nuanced” than they may have intended.  “Iron kills stars” is one of the classics.

 

Just to be clear, if you chuck a bunch of iron into a star, you’ll end up with a lot of vaporized iron that you’ll never get back.  The star itself will do just fine.  The Earth is about 1/3 iron (effectively all of that is in the core), but even if you tossed the entire Earth into the Sun, the most you’d do is upset Al Gore.

 

Stars are always in a balance between their own massive weight that tries to crush their cores, and the heat generated by fusion reactions in the core that pushes all that weight back out.  The more the core is crushed, the hotter and denser it gets, which increases the rate of fusion reactions (increases the cores rate of “explodingness”), which pushes the bulk of the Star away from the core again.  As long as there’s “fuel” in the core, and attempt to crush it will result in the core pushing back.

 

Young stars burn hydrogen, because hydrogen is the easiest element to fuse and also produces the biggest bang.  But hydrogen is the lightest element, which means that older stars end up with a bunch of heavier stuff, like carbon and oxygen and whatnot, cluttering up their cores.  But even that isn’t terribly bad news for the star.  Those new elements can also fuse and produce enough new energy to keep the core from being crushed.  The problem is, when heavier elements fuse they produce less energy than hydrogen did.  So more fuel is needed.  Generally speaking, the heavier the element, the less bang-for-the-buck.

 

Iron is where that slows to a stop.  Iron collecting in the core is like ash collecting in a fire.  It’s not that it somehow actively stops the process, but at the same time: it doesn’t help.  Throw wood on a fire, you get more fire.  Throw ash on a fire, you get hot ash.

 

So, iron doesn’t kill stars so much as it is a symptom of a star that’s about to be done.  Without fuel, the rest of the star is free to collapse the core without opposition, and generally it does.  When there’s a lot of iron being produced in the core, a star probably only has a few hours or seconds left to live.

 

Of course there are elements heavier than iron, and they can undergo fusion as well.  However, rather than producing energy, these elements require additional energy to be created (throwing liquid nitrogen on a fire, maybe?).  That extra energy (which is a lot) isn’t generally available until the outer layers of the star come crushing down on the core.  The energy of all that falling material drives the fusion rate of the remaining lighter elements way, way, way up (supernovas are super for a reason), and also helps power the creation of the elements that make our lives that much more interesting: gold, silver, uranium, lead, mercury, whatever.

 

There are more than a hundred known elements, and iron is only #26.  Basically, if it’s heavy, it’s from a supernova.  Long story short: iron doesn’t kill stars, but right before a (large) star dies, it is full of buckets of iron.

 
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Abel Farias's curator insight, December 2, 2013 5:11 PM

Think Astronomy class. Students are always wondering why stars shine or why they are in the sky. This article opens up another can of worms to intrigue students into further thinking. I would recommend this in a chemistry, physics or astronomy class. It provides information that you can piggy back off of what you would like to teach. For chemistry I would use it to explain properties of elements. 

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Novel gene therapy works to reverse heart failure

Novel gene therapy works to reverse heart failure | Amazing Science | Scoop.it
Researchers have successfully tested a powerful gene therapy, delivered directly into the heart, to reverse heart failure in large animal models.

 

Researchers at the Cardiovascular Research Center at Icahn School of Medicine at Mount Sinai have successfully tested a powerful gene therapy, delivered directly into the heart, to reverse heart failure in large animal models.


The new research study findings, published in November 13 issue of Science Translational Medicine, is the final study phase before human clinical trials can begin testing SUMO-1 gene therapy. SUMO-1 is a gene that is "missing in action" in heart failure patients.


"SUMO-1 gene therapy may be one of the first treatments that can actually shrink enlarged hearts and significantly improve a damaged heart's life-sustaining function," says the study's senior investigator Roger J. Hajjar, MD, Director of the Cardiovascular Research Center at Icahn School of Medicine at Mount Sinai and the Arthur & Janet C. Ross Professor of Medicine at Mount Sinai. "We are very eager to test this gene therapy in our patients suffering from severe heart failure."

 

Heart failure remains a leading cause of hospitalization in the elderly. It accounts for about 300,000 deaths each year in the United States. Heart failure occurs when a person's heart is too weak to properly pump and circulate blood throughout their body.

 

Dr. Hajjar is already on a path toward approval from the Food and Drug Administration to test the novel SUMO-1 gene therapy in heart failure patients. When it begins, the clinical trial will be the second gene therapy treatment designed to reverse heart failure launched by Dr. Hajjar and his Cardiovascular Research Center at Icahn School of Medicine at Mount Sinai.

 

The first trial, named CUPID, is in its final phases of testing SERCA2 gene therapy. Phase 1 and phase 2a trial results were positive, demonstrating substantial improvement in clinical events.

 

In that trial, a gene known as SERCA2 is delivered via an inert virus -- a modified virus without infectious particles. SERCA2 is a gene that produces an enzyme critical to the proper pumping of calcium out of cells. In heart failure, SERCA2 is dysfunctional, forcing the heart to work harder and in the process, to grow larger.

 

The virus carrying SERCA2 is delivered through the coronary arteries into the heart during a cardiac catheterization procedure. Studies show only a one-time gene therapy dose is needed to restore healthy SERCA2a gene production of its beneficial enzyme. But previous research by Mount Sinai discovered SERCA2 is not the only enzyme that is missing in action in heart failure.

 

A study published in Nature in 2011 by Dr. Hajjar and his research group showed that the SUMO-1 gene is also decreased in failing human hearts. But SUMO-1 regulates SERCA2a's activity, suggesting that it can enhance the function of SERCA2a without altering its levels. A follow-up study in a mouse model of heart failure demonstrated that SUMO-1 gene therapy substantially improved cardiac function.

 

This new study tested delivery of SUMO-1 gene therapy alone, SERCA2 gene therapy alone, and a combination of SUMO-1 and SERCA2.

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3D Cosmography of the Local Universe - a film by Hélène Courtois

The large scale structure of the universe is a complex web of clusters, filaments, and voids. Its properties are informed by galaxy redshift surveys and measurements of peculiar velocities. Wiener Filter reconstructions recover three-dimensional velocity and total density fields. The richness of the elements of our neighborhood are revealed with sophisticated visualization tools.


The ability to translate and zoom helps the viewer follow structures in three dimensions and grasp the relationships between features on different scales while retaining a sense of orientation. The ability to dissolve between scenes provides a technique for comparing different information, for example, the observed distribution of galaxies, smoothed representations of the distribution accounting for selection effects, observed peculiar velocities, smoothed and modeled representations of those velocities, and inferred underlying density fields.


The agreement between the large scale structure seen in redshift surveys and that inferred from reconstructions based on the radial peculiar velocities of galaxies strongly supports the standard model of cosmology where structure forms from gravitational instabilities and galaxies form at the bottom of potential wells.

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Animals’ Wildly Varying Reactions to the Smell of Death

Animals’ Wildly Varying Reactions to the Smell of Death | Amazing Science | Scoop.it

To humans, the scent of a rotting corpse is universally abhorrent, the very definition of disgusting. But as strong as that reaction is, many other animals don’t share our unalloyed revulsion. Goldfish are attracted to the smell. Bengal tigers include it in the cocktail of chemicals used to mark their territory. When a rat catches the smell of death on another of its kind, it will bury the stinky rat—even if it’s not actually dead. Many flies are drawn to the smell of death and deposit their eggs at its source. A type of fungus called stinkhorn uses the scent to lure in flies that pick up the stinkhorn’s spores and carry them far away, a noxious reversal of plants’ use of sweet-smelling nectar.


All of these varied behaviors are in response to the same two chemicals, the evocatively named cadaverine and putrescine, which are formed by the breakdown of proteins in the body of a decaying corpse. Animals’ different reactions are clear signs that they process the chemicals differently, but until the release of a study earlier this month, no one had shown how that processing happens.


The new research focused on zebrafish, an animal often used to study the sense of smell in vertebrates. Despite their evolutionary distance from humans, zebrafish have a similar reaction to cadaverine: They get the heck away. (Presumably this reflects an evolutionary drive in both species to avoid the infectious microbes that congregate in dead bodies.) Researchers from Harvard University and the German Institut für Genetik found a receptor in the olfactory neurons of zebrafish that responds specifically to cadaverine—what science writer Elizabeth Preston calls “a rotten-smell button in the brain.”


What’s perhaps most interesting about the cadaverine receptor is that it is a TAAR, a class of sensors that seems to be important for many animals’ perceptions of disgust, including ours. (See the related Facts So Romantic post, “Misdeeds & Disease: How Similar are Disgust & Moral Disgust?”) One TAAR is responsible for mice’s aversion to the smell of predator pee, while one in our own noses “helps” us smell rotting fish, bad breath, and the odor of bacterially infected vagina. The researchers behind the new study say humans probably don’t have the same receptor as the one in zebrafish, but rather a similar one.


As researchers find more matches between the TAARs and the specific molecules they bind, we should get a better understanding of why some smells revolt us so, and why other animals experience them so differently.

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MIT: Inexpensive ‘nano-camera’ can operate at the speed of light

MIT: Inexpensive ‘nano-camera’ can operate at the speed of light | Amazing Science | Scoop.it
Device could be used in medical imaging, collision-avoidance detectors for cars, and interactive gaming.

 

A $500 “nano-camera” that can operate at the speed of light has been developed by researchers in the MIT Media Lab.

The three-dimensional camera, which was presented last week at Siggraph Asia in Hong Kong, could be used in medical imaging and collision-avoidance detectors for cars, and to improve the accuracy of motion tracking and gesture-recognition devices used in interactive gaming.

 

In 2011 Raskar’s group unveiled a trillion-frame-per-second camera capable of capturing a single pulse of light as it travelled through a scene. The camera does this by probing the scene with a femtosecond impulse of light, then uses fast but expensive laboratory-grade optical equipment to take an image each time. However, this “femto-camera” costs around $500,000 to build. 

In contrast, the new “nano-camera” probes the scene with a continuous-wave signal that oscillates at nanosecond periods. This allows the team to use inexpensive hardware — off-the-shelf light-emitting diodes (LEDs) can strobe at nanosecond periods, for example — meaning the camera can reach a time resolution within one order of magnitude of femtophotography while costing just $500.

“By solving the multipath problem, essentially just by changing the code, we are able to unmix the light paths and therefore visualize light moving across the scene,” Kadambi says. “So we are able to get similar results to the $500,000 camera, albeit of slightly lower quality, for just $500.”

Conventional cameras see an average of the light arriving at the sensor, much like the human eye, says James Davis, an associate professor of computer science at the University of California at Santa Cruz. In contrast, the researchers in Raskar’s laboratory are investigating what happens when they take a camera fast enough to see that some light makes it from the “flash” back to the camera sooner, and apply sophisticated computation to the resulting data, Davis says. 

“Normally the computer scientists who could invent the processing on this data can’t build the devices, and the people who can build the devices cannot really do the computation,” he says. “This combination of skills and techniques is really unique in the work going on at MIT right now.” 

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Intestinal bacterial microflora modulates the anticancer immune effects of cyclophosphamide

Intestinal bacterial microflora modulates the anticancer immune effects of cyclophosphamide | Amazing Science | Scoop.it

Cyclophosphamide is one of several clinically important cancer drugs whose therapeutic efficacy is due in part to their ability to stimulate antitumor immune responses. Studying mouse models, we demonstrate that cyclophosphamide alters the composition of microbiota in the small intestine and induces the translocation of selected species of Gram-positive bacteria into secondary lymphoid organs. There, these bacteria stimulate the generation of a specific subset of “pathogenic” T helper 17 (pTH17) cells and memory TH1 immune responses. Tumor-bearing mice that were germ-free or that had been treated with antibiotics to kill Gram-positive bacteria showed a reduction in pTH17 responses, and their tumors were resistant to cyclophosphamide. Adoptive transfer of pTH17 cells partially restored the antitumor efficacy of cyclophosphamide. These results suggest that the gut microbiota help shape the anticancer immune response.

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Printing the Human Body: How It Works and Where It Is Headed

Printing the Human Body: How It Works and Where It Is Headed | Amazing Science | Scoop.it

The rise of 3D printing has introduced one of the most ground-breaking technological feats happening right now. The most exciting part, though, doesn't have anything to do with printing electronics or fancy furniture, but in producing human tissues, otherwise known as bioprinting. While it is still in its infancy, the future of bioprinting looks very bright and will eventually result in some major advances for society, whilst also saving billions for the economy this is spent on research and development.

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Peter Phillips's curator insight, November 27, 2013 1:55 PM

I can't see this saving money - but it will save lives. The technology to print exists. It is the question of how to develop stem cells into tissue types and then how to link these with the bodies complex control systems (nervous, circulatory and immune). in the best case scenario a grown organ will be recognised as self and the body systems will grow into them. However, organs are not toasters. Researchers are concentrating on easy things like skin grafts and ears at present, but like nano electronics, the future is full of potential and questions.

Steve Kingsley's curator insight, November 27, 2013 9:27 PM

Will HP buy Organovo, which invented and produces the NovoGen bioprinter?

Pamela D Lloyd's curator insight, November 29, 2013 5:46 PM

Such astonishingly wonderful ways to use the new 3D printing technology.

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Captive-bred Tasmanian devils thriving on Maria Island, free from facial tumors

Captive-bred Tasmanian devils thriving on Maria Island, free from facial tumors | Amazing Science | Scoop.it
Conservationists say a relocated population of Tasmanian devils is now thriving on an island safe haven, free from a deadly facial tumour disease which has plagued the species.

 

The devils were bred in captivity and first released on Maria Island off Tasmania's east coast a year ago, and are now interacting with tourists and breeding. The devils have since had about 20 babies, and there are now about 50 devils on the island. The relocation program is a test case to see if mainland Tasmania can be repopulated with captive bred devils if all the wild animals are killed by a contagious facial cancer.


David Pemberton, the manager of the Save the Devil Program, says a similar release will soon happen down on the Tasman peninsula following the Maria Island success.

 

"We're looking at Forestier and Tasman, and we've done a lot of ground work there, and we're hoping to be ready to re-introduce animals there in 2015," Mr Pemberton said.

 

"It's a bit early to pick the exact date because it all depends on how confident we are that we've got disease off those two peninsulas.

 

"That's the critical aspect. Once we’ve made that decision then we can plan the re-introduction."

  
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CRISPR-Cas: A powerful new tool for precise genetic engineering

CRISPR-Cas: A powerful new tool for precise genetic engineering | Amazing Science | Scoop.it

Viruses cannot only cause illnesses in humans, they also infect bacteria. Those protect themselves with a kind of ‘immune system’ which – simply put – consists of specific sequences in the genetic material of the bacteria and a suitable enzyme. It detects foreign DNA, which may originate from a virus, cuts it up and thus makes the invaders harmless. Scientists from the Helmholtz Centre for Infection Research (HZI) in Braunschweig have now shown that the dual-RNA guided enzyme Cas9 which is involved in the process has developed independently in various strains of bacteria. This enhances the potential of exploiting the bacterial immune system for genome engineering.

 

Even though it has only been discovered in recent years the immune system with the cryptic name ‘CRISPR-Cas’ has been attracting attention of geneticists and biotechnologists as it is a promising tool for genetic engineering. CRISPR is short for Clustered Regularly Interspaced Palindromic Repeats, whereas Cas simply stands for the CRISPR-associated protein. Throughout evolution, this molecule has developed independently in numerous strains of bacteria. This is now shown by Prof Emmanuelle Charpentier and her colleagues at the Helmholtz Centre for Infection Research (HZI) who published their finding in the international open access journal Nucleic Acids Research.

 

The CRISPR-Cas-system is not only valuable for bacteria but also for working in the laboratory. It detects a specific sequence of letters in the genetic code and cuts the DNA at this point. Thus, scientists can either remove or add genes at the interface. By this, for instance, plants can be cultivated which are resistant against vermins or fungi. Existing technologies doing the same thing are often expensive, time consuming or less accurate. In contrast to them the new method is faster, more precise and cheaper, as fewer components are needed and it can target longer gene sequences.

 

Additionally, this makes the system more flexible, as small changes allow the technology to adapt to different applications. “The CRISPR-Cas-system is a very powerful tool for genetic engineering,“ says Emmanuelle Charpentier, who came to the HZI from Umeå and was awarded with the renowned Humboldt Professorship in 2013. “We have analysed and compared the enzyme Cas9 and the dual-tracrRNAs-crRNAs that guide this enzyme site-specifically to the DNA in various strains of bacteria.” Their findings allow them to classify the Cas9 proteins originating from different bacteria into groups. Within those the CRISPR-Cas systems are exchangeable which is not possible between different groups.

 

This allows for new ways of using the technology in the laboratory: The enzymes can be combined and thereby a variety of changes in the target-DNA can be made at once. Thus, a new therapy for genetic disorders caused by different mutations in the DNA of the patient could be on the horizon. Furthermore, the method could be used to fight the AIDS virus HIV which uses a receptor of the human immune cells to infect them. Using CRISPR-Cas, the gene for the receptor could be removed and the patients could become immune to the virus. However, it is still a long way until this aim will be reached.

 

Still those examples show the huge potential of the CRISPR-Cas technology. “Some of my colleagues already compare it to the PCR,” says Charpentier. This method, developed in the 1980s, allows scientists to ‘copy’ nucleic acids and therefore to manifold small amounts of DNA to such an extent that they can be analysed biochemically. Without this ground-breaking technology a lot of experiments we consider to be routine would have never been possible.

 

Charpentier was not looking for new molecular methods in the first place. “Originally, we were looking for new targets for antibiotics. But we found something completely different,” says Charpentier. This is not rare in science. In fact some of the most significant scientific discoveries have been made incidentally or accidentally.

 

Reference:

Ines Fonfara, Anaïs Le Rhun, Krzysztof Chylinski, Kira Makarova, Anne-Laure Lécrivain, Janek Bzdrenga, Eugene V. Koonin, Emmanuelle Charpentier: Phylogeny of Cas9 determines functional exchangeability of dual-RNA and Cas9 among orthologous type II CRISPR-Cas systems.

 

Nucleic Acids Research, 2013, DOI: 10.1093/nar/gkt1074

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The Leidenfrost Effect: Physicists Make Water Flow Uphill

In the Leidenfrost Effect, a water droplet will float on a layer of its own vapor if heated to certain temperature. This common cooking phenomenon takes center stage in a series of playful experiments by physicists at the University of Bath, who discovered new and fun means to manipulate the movement of water.

Researchers test ridged surfaces in order to control the movements of hot water.

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How close are we to finding dark matter?

How close are we to finding dark matter? | Amazing Science | Scoop.it

Dark matter makes up about a quarter of the cosmos, but we still don't know what it is. As part of a two-part series called Light & Dark on BBC Four, physicist Jim Al-Khalili pondered how close we are to understanding the mysterious "dark stuff".

 

Given all the progress we've made in modern physics over the past century, you may be forgiven for thinking that physicists are approaching a complete understanding of what makes up everything in our Universe.

 

For example, all the publicity surrounding the discovery of the Higgs boson last year seemed to be suggesting that this was one of the final pieces of the jigsaw - that all the fundamental building blocks of reality were now known.

 

So it might come as something of a shock to many people to hear that we still don't know what 95% of the Universe is made of. The stars in galaxies revolve around like undissolved coffee granules on the surface of you mug of coffee just after you've stopped stirring it.


It's all rather embarrassing. Everything we see: our planet and everything on it, the moon, the other planets and their moons, the Sun, all the stars in the sky that make up our Milky Way galaxy, all the other billions of galaxies beyond with their stars and clouds of interstellar gas, as well as all the dead stars and black holes that we can no longer see; it all amounts to less than 5% of the Universe.

 

And we don't even know if space goes on for ever, what shape the Universe is, what caused the Big Bang that created it, even whether it is just one of many embedded multiverses.

 
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malik matwi's comment, December 13, 2015 3:17 PM
neither dark matter nor energy http://iiste.org/Journals/index.php/APTA/article/view/26837
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Smartphone Physicals Are Taking Off With Explosion of Apps, Attachments

Smartphone Physicals Are Taking Off With Explosion of Apps, Attachments | Amazing Science | Scoop.it

There’s no shortage of smartphone appsto help people track their health. And in recent months, medical apps have started growing up, leaving behind the novelty of attaching probes to a smartphone to offer, they hope, serious clinical tools.

 

Last month in a Ted Talk, Shiv Gaglani showed that a standard physical exam can now be done using only smartphone apps and attachments. From blood pressure cuff to stethoscope and otoscope — the thing the doctor uses to look in your ears — all of the doctor’s basic instruments are now available in “smart” format.

 

 


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odysseas spyroglou's curator insight, November 30, 2013 1:10 PM

Smartphones in the service of health industry.

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Signs of Aging, Even in the Embryo

Signs of Aging, Even in the Embryo | Amazing Science | Scoop.it
New research indicates that senescent cells, those that stop dividing, play an important role at both the dawn and dusk of life.

 

In 1961, two biologists named Leonard Hayflick and Paul Moorehead discovered that old age is built into our cells. At the time, many scientists believed that if healthy human cells were put in a flask with a steady supply of nutrients, they would multiply forever. But when Dr. Hayflick and Dr. Moorehead reared fetal human cells, that’s not what they found. Time and again, their cells would divide about 50 times and then simply stop.


In fact, it turned out, senescent cells are involved in many of the ravages of old age. Wrinkled skin, cataracts and arthritic joints are rife with senescent cells. When researchers rid mice of senescent cells, the animals become rejuvenated.

 

Given all this research, the last place you would expect to find senescent cells would be at the very start of life. But now three teams of scientists are reporting doing just that. For the first time, they have found senescent cells in embryos, and they have offered evidence that senescence is crucial to proper development.

 

The discoveries raise the prospect that the dawn and dusk of life are intimately connected. For life to get off to the right start, in other words, youth needs a splash of old age.

 

Scott Lowe, an expert on senescence at Memorial Sloan-Kettering Cancer Center who was not involved in the research, praised the studies for pointing to an unexpected role for senescence. He predicted they would provoke a spirited debate among developmental biologists who study how embryos form. “They’re going to really love it or really hate it,” Dr. Lowe said.

 

While senescence may be a powerful defense against cancer, however, it comes at a steep cost. Even as we escape cancer, we accumulate a growing supply of senescent cells. The chronic inflammation they trigger can damage surrounding tissue and harm our health.

 

In the mid-2000s, William Keyes, a biologist then at Cold Spring Harbor Laboratory on Long Island, was studying how senescence leads to aging with experiments on mice. By shutting down a gene called P63, he could accelerate the rate at which the mice accumulated senescent cells — and accelerate their aging.

 

To observe the senescent cells, Dr. Keyes added a special stain to the bodies of these mice. To see the difference between these mice and normal ones, Dr. Keyes added the same stain to normal mouse embryos.

Naturally, he expected that none of the cells in the normal mouse embryos would turn dark. After all, senescent cells had been found only in old or damaged tissues. Much to his surprise, however, Dr. Keyes found patches of senescent cells in the normal mouse embryos. Dr. Keyes decided to look again at those peculiar senescent cells in normal embryos. He and his colleaguesconfirmed that cells became senescent in many parts of an embryo, such as along the developing tips of the legs.

 

The researchers, however, found no evidence that the senescent cells in embryos have damaged DNA. That discovery raises the question of how the cells were triggered to become senescent. Dr. Keyes hypothesizes they did so in response to a signal from neighboring cells.

 

Once an embryonic cell becomes senescent, it does the two things that all senescent cells do: it stops dividing and it releases a special cocktail. 

The new experiments suggest that this cocktail plays a different role in the embryo than in the adult body. It may act as a signal to other cells to become different tissues. It may also tell those tissues to grow at different rates into different shapes.

 

Dr. Keyes suspects that the sculpting that senescent cells carry out may be crucial to the proper development of an embryo. Consequently, any disruption to senescent cells may have dire consequences. “Where we see senescence in the embryo is where we see a lot of different birth defects,” he said.


For an embryo to develop properly, signals have to be sent to the right places at the right times. The peculiar behavior of senescent cells may help in both regards. If a cell stops growing, it won’t spread too far from a particular spot in an embryo. And by summoning immune cells to kill it, a senescent cell may ensure that its signals don’t last too long.

 

It’s possible, Dr. Keyes speculates, that senescence actually evolved first as a way to shape embryos; only later in evolution did it take on a new role, as a weapon against cancer. “I like the idea that it was a simple process that was then modified,” Dr. Keyes said.

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Madison Punch's comment, March 24, 2014 7:14 PM
I found this article to be among the coolest I've read from scoop.it. I figured that aging came with the weakening, or rather aging, of the body. Who knew it was basically "installed" into our cells? The end of cell division basically stops the flourishing of the peak of life and begins to fall into aging. Very cool.
Madison Carson's comment, September 1, 2015 8:44 PM
I found this article to be rather cool. I've never heard of some of the cells that they were talking about. I thought that the older you got, the effects of old age would just come with it. But, seeing that old age is in you from the time you were born is very interesting.
andrea luan villa's comment, February 2, 2016 6:58 PM
I didn't know that old age is built into our cells; that very cool. I also didn't know that embryos had senses. this interesting I learned a lot from it.
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Developing a Fax Machine to Copy Life on Mars

Developing a Fax Machine to Copy Life on Mars | Amazing Science | Scoop.it
DNA sequencing and DNA synthesis are becoming faster and cheaper, and J. Craig Venter wants to use the technology to bring Martian life to Earth.

 

 J. Craig Venter is looking for a new world to conquer — Mars. He wants to detect life on Mars and bring it to Earth using a device called a digital biological converter, or biological teleporter. Although the idea conjures up “Star Trek,” the analogy is not exact. The transporter on that program actually moves Captain Kirk from one location to another. Dr. Venter’s machine would merely create a copy of an organism from a distant location — more like a biological fax machine.


Still, Dr. Venter, known for his early sequencing of the human genome and for his bold proclamations, predicts the biological converter will be his next innovation and will be useful on Earth well before it could ever be deployed on the red planet.

 

The idea behind it, not original to him, is that the genetic code that governs life can be stored in a computer and transmitted just like any other information.

 

Dr. Venter’s system would determine the sequence of the DNA units in an organism’s genome and transmit that information electronically. At the distant location, the genome would be synthesized — or chemically recreated — inserted into what amounts to a blank cell, and “booted up,” as Mr. Venter puts it. In other words, the inserted DNA would take command of the cell and recreate a copy of the original organism.

 

To test some ideas, he and a small team of scientists from his company and from NASA spent the weekend here in the Mojave Desert, the closest stand-in they could find for the dry surface of Mars.

 

The biological fax is not as far-fetched as it seems. DNA sequencing and DNA synthesis are rapidly becoming faster and cheaper. For now, however, synthesizing an organism’s entire genome is still generally too difficult. So the system will first be used to remotely clone individual genes, or perhaps viruses. Single-celled organisms like bacteria might come later. More complex creatures, earthly or Martian, will probably never be possible.

 

Dr. Venter’s company, Synthetic Genomics, and his namesake nonprofit research institute have already used the technology to help develop an experimental vaccine for the H7N9 bird flu with the drug maker Novartis.

 

Typically, when a new strain of flu virus appears, scientists must transport it to labs, which can spend weeks perfecting a strain that can be grown in eggs or animal cells to make vaccine.

 

But when H7N9 appeared in China in February, its genome was sequenced by scientists there and made publicly available. Within days, Dr. Venter’s team had synthesized the two main genes and used them to make a vaccine strain, without having to wait for the virus to arrive from China.

 

Dr. Venter said Synthetic Genomics would start selling a machine next year that would automate the synthesis of genes by stringing small pieces of DNA together to make larger ones.

 

Eventually, he said, “we’ll have a small box like a printer attached to your computer.” A person with a bacterial infection might be sent the code to recreate a virus intended to kill that specific bacterium.

 

“We can send an antibiotic as an email,” said Dr. Venter, who has outlined his ideas in a new book, “Life at the Speed of Light: From the Double Helix to the Dawn of Digital Life.” Proteins might also be made, so that diabetics, for instance, could “download insulin from the Internet.”

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A Thin Sheet of Reality: Discussion about the Universe as a Hologram (Full VIDEO)

From the World Science Festival 2011:

 

What we touch. What we smell. What we feel. They're all part of our reality. But what if life as we know it reflects only one side of the full story? Some of the world's leading physicists think that this may be the case. They believe that our reality is a projection—sort of like a hologram—of laws and processes that exist on a thin surface surrounding us at the edge of the universe. Although the notion seems outlandish, it's a long-standing theory that initially emerged years ago from scientists studying black holes; recently, a breakthrough in string theory propelled the idea into the mainstream of physics. What took place was an intriguing discussion on the cutting-edge results that may just change the way we view reality.

Panel includes John Hockenberry, an award-winning journalist with twenty-five years experience in radio, broadcast television and print. He is the host of WNYC and PRI's The Takeaway, a correspondent for PBS Frontline, and a noted presenter and moderator at conferences such at TED, Aspen Ideas, and the World Science Festival. 

Gerardus 't Hooft, born on July 5, 1946, in Den Helder, Netherlands. He received his doctorate in theoretical physics in 1972 at Utrecht University on "The Renormalization Procedure for Yang-Mills Fields", this work would later earn him, together with his advisor Martinus Veltman, the 1999 Nobel Prize in Physics. Dr. 't Hooft has been Professor in Theoretical Physics at Utrecht for most of his professional life, doing research and education on the topics of the electro-weak interaction, the strong interaction and later also the gravitational forces in the world of the sub-atomic particles. Member of the Dutch Academy of Sciences (KNAW) as well as other institutions and academies, his work led to a number of honorary doctorates and international prizes such as the Wolf Prize of Israel, the Pius XI Medal, and the Franklin Medal.

Leonard Susskind, the Felix Bloch Professor of Theoretical Physics at Stanford University, and one of the discoverers of string theory, a candidate for a theory that unifies all laws of physics. An award-winning author, he is a proponent of the idea that our universe is one of an infinite number. 

Herman Verlinde, a renowned physicist and influential contributor to string theory and its application in mathematics, particle physics, cosmology, and black hole physics. Herman Verlinde's research has been recognized through several awards and fellowships from the Packard Foundation, the Sloan Foundation, and the Royal Dutch Academy of Science. In 1988, Verlinde received his Ph.D. at Utrecht University under the supervision of Gerard't Hooft. From 1994 to 1998, he was professor of physics at the University of Amsterdam, where he founded its Center for Mathematical Physics. In 2008 and 2009, he was a visiting member at the Institute of Advanced Study in Princeton. Herman Verlinde is the twin brother of Erik Verlinde, who is also a prominent string theorist and professor of physics at the University of Amsterdam.

Raphael Bousso is recognized for discovering the general relation between the curved geometry of space-time and its information content, known as the "covariant entropy bound." This allowed for a precise and general formulation of the holographic principle, which is believed to underlie the unification of quantum theory and Einstein's theory of gravity. Bousso is also one of the discoverers of the landscape of string theory, which explains the small but non-vanishing value of the cosmological constant or "dark energy". His work has led to a novel view of cosmology, the multiverse of string theory. Bousso is currently professor of physics at the University of California, Berkeley.

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Big Weather Pattern on Hot Jupiter Exoplanets

Among the hundreds of new planets discovered by NASA's Kepler spacecraft are a class of exotic worlds known as "hot Jupiters."  Unlike the giant planets of our own solar system, which remain at a safe distance from the sun, these worlds are reckless visitors to their parent stars. They speed around in orbits a fraction the size of Mercury’s, blasted on just one-side by starlight hundreds of times more intense than the gentle heating experienced by Jupiter here at home. Meteorologists watching this video are probably wondering what kind of weather a world like that might have. The short answer is "big."

 

Heather Knutson of Caltech made the first weather map of a hot Jupiter in 2007. "It's not as simple as taking a picture and--voila!—we see the weather," says Knutson. These planets are hundreds of light years from Earth and they are nearly overwhelmed by the glare of their parent stars. "Even to see the planet as a single pixel next to the star would be a huge accomplishment."

 

Instead, Knutson and colleagues use a trick dreamed up by Nick Cowan of Northwestern University. The key, she explains, is that "most hot Jupiters are tidally locked to their stars. This means they have a permanent dayside and a permanent night side.  As we watch them orbit from our vantage point on Earth, the planets exhibit phases--e.g., crescent, gibbous and full.  By measuring the infrared brightness of the planet as a function of its phase, we can make a rudimentary map of temperature vs. longitude."

 

 This exoplanet weather map shows temperatures on a hot Jupiter known as "HAT-P-2b". NASA’s Spitzer Space Telescope is the only infrared observatory with the sensitivity to do this work.  Since Knutson kick-started the research in 2007, nearly a dozen hot Jupiters have been mapped by astronomers using Spitzer.

 

The most recent study, led by Nikole Lewis, a NASA Sagan Exoplanet Fellow working at MIT, shows a gas giant named HAT-P-2b. "We can see daytime temperatures as high as 2400 K," says Lewis, "while the nightside drops below 1200K.  Even at night," she marvels, "this planet is ten times hotter than Jupiter."

 

These exoplanet maps may seem crude compared to what we’re accustomed to on Earth, but they are a fantastic accomplishment considering that the planets are trillions of miles away.

 

The maps show huge day-night temperature differences typically exceeding 1000 degrees.  Researchers believe these thermal gradients drive ferocious winds blowing thousands of miles per hour.

 

Without regular pictures, researchers can’t say what this kind of windy weather looks like. Nevertheless, Knutson is willing to speculate using climate models of Jupiter as a guide. "Weather on hot Jupiters," she predicts, "is really big." 

 

Over the years, planetary scientists have developed computer models to reproduce the storms and cloud belts in Jupiter’s atmosphere.  If you take those models and turn up the heat, and slow down the rotation to match the tidally-locked spin of a hot Jupiter, weather patterns become super-sized. For instance, on a hot Jupiter the Great Red Spot might grow as large as a quarter the size of the planet and manifest itself in both the northern and southern hemispheres.


"Just imagine what that would look like--a pair of giant eyes staring out into space!" says Lewis. Meanwhile, Jupiter’s famous belts would widen so much that only two or three would fit across the planet’s girth. Ordinary clouds of water and methane couldn’t form in such a hot environment. Instead, Knutson speculates that hot Jupiters might have clouds made of silicate—that is, "rock clouds."

 

"Silicates are predicted to condense in such an environment," she says. "We're already getting some hints that clouds might be common on these planets, but we don’t yet know if they’re made of rock." For now just one thing is certain: The meteorology of hot Jupiters is out of this world.

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No more injections? Nanoparticles as pills of the future

No more injections? Nanoparticles as pills of the future | Amazing Science | Scoop.it
Researchers design drug-carrying nanoparticles that can be taken orally

 

Several types of nanoparticles carrying chemotherapy drugs or short interfering RNA, which can turn off selected genes, are now in clinical trials to treat cancer and other diseases. These particles exploit the fact that tumors and other diseased tissues are surrounded by leaky blood vessels. After the particles are intravenously injected into patients, they seep through those leaky vessels and release their payload at the tumor site. 

For nanoparticles to be taken orally, they need to be able to get through the intestinal lining, which is made of a layer of epithelial cells that join together to form impenetrable barriers called tight junctions.

“The key challenge is how to make a nanoparticle get through this barrier of cells. Whenever cells want to form a barrier, they make these attachments from cell to cell, analogous to a brick wall where the bricks are the cells and the mortar is the attachments, and nothing can penetrate that wall,” Farokhzad says.

Researchers have previously tried to break through this wall by temporarily disrupting the tight junctions, allowing drugs through. However, this approach can have unwanted side effects because when the barriers are broken, harmful bacteria can also get through. 

To build nanoparticles that can selectively break through the barrier, the researchers took advantage of previous work that revealed how babies absorb antibodies from their mothers’ milk, boosting their own immune defenses. Those antibodies grab onto a cell surface receptor called the FcRN, granting them access through the cells of the intestinal lining into adjacent blood vessels. 

The researchers coated their nanoparticles with Fc proteins — the part of the antibody that binds to the FcRN receptor, which is also found in adult intestinal cells. The nanoparticles, made of a biocompatible polymer called PLA-PEG, can carry a large drug payload, such as insulin, in their core. 

After the particles are ingested, the Fc proteins grab on to the FcRN in the intestinal lining and gain entry, bringing the entire nanoparticle along with them. 

“It illustrates a very general concept where we can use these receptors to traffic nanoparticles that could contain pretty much anything. Any molecule that has difficulty crossing the barrier could be loaded in the nanoparticle and trafficked across,” Karnik says. 

The researchers’ discovery of how this type of particle can penetrate cells is a key step to achieving oral nanoparticle delivery, says Edith Mathiowitz, a professor of molecular pharmacology, physiology, and biotechnology at Brown University.

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Dinosaur-Killing Comet Didn't Wipe Out Freshwater Species

Dinosaur-Killing Comet Didn't Wipe Out Freshwater Species | Amazing Science | Scoop.it

New research shows freshwater organisms fared better than others after the most recent extinction event.

 

The mass extinction event the scientists studied (also the most recent and most familiar) is known as the K-T event or, more recently, the K-Pg event. The disaster, which killed off at least 75 percent of all species on Earth, including all dinosaurs except for birds, was apparently triggered by a cosmic impact that occurred in what is now Mexico about 65 million years ago.

 

Past research suggested that while marine life was devastated by this mass extinction, freshwater organisms underwent relatively low extinction rates. Now investigators suggest the secret of their survival may have been all the variability experienced by freshwater life.

 

Water would have helped shelter life in rivers and lakes, as well as the seas and oceans, from the initial blast of heat from the cosmic impact. However, the giant extraterrestrial collision set fire to Earth's surface, darkening the sky with dust and ash that cooled the planet. The resulting "impact winter" and its lack of sunlight would have crippled both freshwater and marine food chains by killing off microscopic photosynthetic organisms known as phytoplankton that are at the base of the marine and freshwater food chains.

 

Intriguingly, while marine communities were devastated by the mass extinction, losing 50 percent of their species, geophysicist Douglas Robertson at the University of Colorado at Boulder and his colleagues looked at a database of western North America fossils and discovered freshwater ones there survived relatively unscathed, losing only about 10 percent of their species.

 

The researchers note that freshwater organisms, unlike marine life, are used to annual freezes that ice over inland waters, severely limiting their oxygen supplies. As such, freshwater communities might have better endured the low oxygen levels in the wake of the death of photosynthetic life following an impact winter. 

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KOI-351: Second Planetary System Like Ours Discovered

KOI-351: Second Planetary System Like Ours Discovered | Amazing Science | Scoop.it

A team of European astronomers has discovered a second planetary system, the closest parallel to our own solar system yet found. It includes seven exoplanets orbiting a star with the small rocky planets close to their host star and the gas giant planets further away. The system was hidden within the wealth of data from the Kepler Space Telescope.

 

KOI-351 is “the first system with a significant number of planets (not just two or three, where random fluctuations can play a role) that shows a clear hierarchy like the solar system — with small, probably rocky, planets in the interior and gas giants in the (exterior),” Dr. Juan Cabrera, of the Institute of Planetary Research at the German Aerospace Center.


Three of the seven planets orbiting KOI-351 were detected earlier this year, and have periods of 59, 210 and 331 days — similar to the periods of Mercury, Venus and Earth.

 

But the orbital periods of these planets vary by as much as 25.7 hours. This is the highest variation detected in an exoplanet’s orbital period so far, hinting that there are more planets than meets the eye.

In closely packed systems, the gravitational pull of nearby planets can cause the acceleration or deceleration of a planet along its orbit. These “tugs” cause the variations in orbital periods.

 

They also provide indirect evidence of further planets. Using advanced computer algorithms, Cabrera and his team detected four new planets orbiting KOI-351.

 

But these planets are much closer to their host star than Mercury is to our Sun, with orbital periods of 7, 9, 92 and 125 days. The system is extremely compact — with the outermost planet having an orbital period less than the Earth’s. Yes, the entire system orbits within 1 AU.

 

While astronomers have discovered over 1000 exoplanets, this is the first solar system analogue detected to date. Not only are there seven planets, but they display the same architecture — rocky small planets orbiting close to the sun and gas giants orbiting further away — as our own solar system.

 

Most exoplanets are strikingly different from the planets in our own solar system. “We find planets in any order, at any distance, of any size; even planetary classes that don’t exist in the solar system,” Cabrera said.

 

Several theories including planet migration and planet-planet scattering have been proposed to explain these differences. But the fact of the matter is planet formation is still poorly understood.

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Lynnette Van Dyke's curator insight, November 28, 2013 4:55 PM

WHat are the implications? Worth some critical thought .

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Bees And Flowers Speak In A Secret UV Color Code

Bees And Flowers Speak In A Secret UV Color Code | Amazing Science | Scoop.it
Flowers may use UV patterns to attract bees. See how, and check out photos that shows us approximately what a bee sees when it looks at flowers.

 

UV fluorescence may be a common trait to most flowers, but might be of temporary occurrence for parts of the flower. Anthers, style, and pollen grains occasionally are seen to fluoresce. Strong fluorescence has been noted from nectar glands (Angelica sylvestris) and several other species. Some species show fluorescence of the non-fertilised stigmas, but this trait is difficult to document with my normal technical approach. Fluorescence from outside of the bracts is exhibited by some species. As far as the photography is concerned, the main issue with flower fluorescence is its transient behaviour. It may be present, but the flowers collected for photography don't appear to fluoresce simply because the floral development is in the "wrong" stage. With fluorescent pollen grains, their size often are at or below the detection limit unless quite high magnification is employed, thus calling for a true photomacropgraphic approach. The fluorescing pollen of Mirabilis jalapa has been documented using this method.


UV-absorbing substances (flavonyl glucosides) are instrumental in bringing about the fascinating pollinating guide patterns. UV marks on flowers are but a logical extension of the visual pollinating clues provided by evolution in nature. If the flower absorbs UV all over the floral parts, it may appear visually in a "UV-complementary" color even to pollinators capable of seeing in UV. We can only speculate as to the rendition of that complementary color, but if say the insect is modelled as seeing UV as "blue", blue as "green", and green as "red", then the UV complementary would be yellow. Thus, a UV-absorbing yellow flower still would come across as "yellow" even for an insect (or so it might seem, but who are we to know such things anyway).

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Einstein@Home: Home Computers Discover Gamma-Ray Pulsars

Einstein@Home: Home Computers Discover Gamma-Ray Pulsars | Amazing Science | Scoop.it

The combination of globally distributed computing power and innovative analysis methods proves to be a recipe for success in the search for new pulsars. Scientists from the Max Planck Institutes for Gravitational Physics and Radio Astronomy together with international colleagues have now discovered four gamma-ray pulsars in data from the Fermi space telescope. The breakthrough came using the distributed computing project Einstein@Home, which connects more than 200,000 computers from 40,000 participants around the world to a global supercomputer. The discoveries include volunteers from Australia, Canada, France, Germany, Japan, and the USA.


Since its launch in 2008, the Fermi satellite has been observing the entire sky in gamma-rays. It has discovered thousands of previously unknown gamma-ray sources, among which are possibly hundreds of yet undiscovered pulsars – compact and rapidly rotating remnants of exploded stars. Identifying these new gamma-ray pulsars, however, is computationally very expensive – wide parameter ranges have to be “scanned” at very high resolution.

 

“Our innovative solution for the compute intensive search for gamma-ray pulsars is the combination of particularly efficient methods along with the distributed computing power of Einstein@Home,” says Holger Pletsch, Independent Research Group Leader at the Max Planck Institute for Gravitational Physics (Albert Einstein Institute/AEI), and lead author of the study. “The volunteers from around the world enable us to deal with the huge computational challenge posed by the Fermi data analysis. In this way, they provide an invaluable service to astronomy,” says Pletsch.

 

Einstein@Home is a joint project of the Center for Gravitation and Cosmology at the University of Wisconsin–Milwaukee and the AEI in Hannover. It is funded by the National Science Foundation and the Max Planck Society. Since mid-2011, Einstein@Home has been searching for signals from gamma-ray pulsars in Fermi data. The project was founded in 2005 to search for gravitational-wave signals in data from the LIGO detectors – still the main task of Einstein@Home. Since early 2009, the project has also been conducting successful searches for new radio pulsars.


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How do you sense the passing of time? Your brain has two clocks

How do you sense the passing of time? Your brain has two clocks | Amazing Science | Scoop.it

Did you make it to work on time this morning? Go ahead and thank the traffic gods, but also take a moment to thank your brain. The brain’s impressively accurate internal clock allows us to detect the passage of time, a skill essential for many critical daily functions. Without the ability to track elapsed time, our morning shower could continue indefinitely. Without that nagging feeling to remind us we’ve been driving too long, we might easily miss our exit. 

 

But how does the brain generate this finely tuned mental clock? Neuroscientists believe that we have distinct neural systems for processing different types of time, for example, to maintain a circadian rhythm, to control the timing of fine body movements, and for conscious awareness of time passage. Until recently, most neuroscientists believed that this latter type of temporal processing – the kind that alerts you when you’ve lingered over breakfast for too long – is supported by a single brain system. However, emerging research indicates that the model of a single neural clock might be too simplistic. A new study, recently published in the Journal of Neuroscience by neuroscientists at the University of California, Irvine, reveals that the brain may in fact have a second method for sensing elapsed time. What’s more, the authors propose that this second internal clock not only works in parallel with our primary neural clock, but may even compete with it.

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