Amazing Science
Follow
368.5K views | +226 today
 
Scooped by Dr. Stefan Gruenwald
onto Amazing Science
Scoop.it!

Most of the harmful mutations in humans arose in the past 5,000 to 10,000 years

Most of the harmful mutations in humans arose in the past 5,000 to 10,000 years | Amazing Science | Scoop.it

European Americans have a larger proportion of potentially harmful variants than African Americans --- probably an artefact of their original migration out of Africa.

 

The human genome has been busy over the past 5,000 years. Human populations have grown exponentially, and new genetic mutations arise with each generation. Humans now have a vast abundance of rare genetic variants in the protein-encoding sections of the genome.

 

A study published in Nature now helps to clarify when many of those rare variants arose. Researchers used deep sequencing to locate and date more than one million single-nucleotide variants — locations where a single letter of the DNA sequence is different from other individuals — in the genomes of 6,500 African and European Americans.

 

The findings confirm their earlier work suggesting that the majority of variants, including potentially harmful ones, were picked up during the past 5,000–-10,000 years.

more...
Whitney Souery's curator insight, August 29, 2013 12:49 PM

Genetic mutations (both negative and positive included) arose during migration. This article descirbes how European Americans have a greater amount of mutations than African Americans- meaning that after the migration from Africa, mutations began to arise. 

Your new post is loading...
Scooped by Dr. Stefan Gruenwald
Scoop.it!

20,000+ FREE Online Science and Technology Lectures from Top Universities

20,000+ FREE Online Science and Technology Lectures from Top Universities | Amazing Science | Scoop.it

NOTE: To subscribe to the RSS feed of Amazing Science, copy http://www.scoop.it/t/amazing-science/rss.xml into the URL field of your browser and click "subscribe".

 

This newsletter is aggregated from over 1450 news sources:

http://www.genautica.com/links/1450_news_sources.html

 

All my Tweets and Scoop.It! posts sorted and searchable:

http://www.genautica.com/tweets/index.html

 

••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••

You can search through all the articles semantically on my

archived twitter feed

••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••

NOTE: All articles in the amazing-science newsletter can also be sorted by topic. To do so, click the FIND buntton (symbolized by the FUNNEL on the top right of the screen)  and display all the relevant postings SORTED by TOPICS.

 

You can also type your own query:

 

e.g., you are looking for articles involving "dna" as a keyword

 

http://www.scoop.it/t/amazing-science/?q=dna


Or CLICK on the little

FUNNEL symbol at the

 top right of the screen

••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••••


MOST_READ • 3D_printing • aging • AI • anthropology • art • astronomy • bigdata • bioinformatics • biology • biotech • chemistry • computers • cosmology • education • environment • evolution • future • genetics • genomics • geosciences • green_energy • history • language • map • material_science • math • med • medicine • microscopy • nanotech • neuroscience • paleontology • photography • photonics • physics • postings • robotics • science • technology • video 

more...
Margarida Sá Costa's curator insight, January 31, 9:55 AM

Lectures are in Playlists and are alphabetically sorted with thumbnail pictures. No fee, no registration required - learn at your own pace. Certificates can be arranged with presenting universities.

Casper Pieters's curator insight, March 9, 7:21 PM

Great resources for online learning just about everything.  All you need is will power and self- discipline.

Siegfried Holle's curator insight, July 4, 8:45 AM

Your knowledge is your strength and power 

Scooped by Dr. Stefan Gruenwald
Scoop.it!

Certain 'memories' pass between generations

Certain 'memories' pass between generations | Amazing Science | Scoop.it

Behavior can be affected by events in previous generations which have been passed on through a form of genetic memory, animal studies suggest. Experiments showed that a traumatic event could affect the DNA in sperm and alter the brains and behaviour of subsequent generations.

A Nature Neuroscience study shows mice trained to avoid a smell passed their aversion on to their "grandchildren". Experts said the results were important for phobia and anxiety research. The animals were trained to fear a smell similar to cherry blossom. The team at the Emory University School of Medicine, in the US, then looked at what was happening inside the sperm.


They showed a section of DNA responsible for sensitivity to the cherry blossom scent was made more active in the mice's sperm. Both the mice's offspring, and their offspring, were "extremely sensitive" to cherry blossom and would avoid the scent, despite never having experienced it in their lives. Changes in brain structure were also found.


"The experiences of a parent, even before conceiving, markedly influence both structure and function in the nervous system of subsequent generations," the report concluded. The findings provide evidence of "trans-generational epigenetic inheritance" - that the environment can affect an individual's genetics, which can in turn be passed on.


Prof Marcus Pembrey, from University College London, said the findings were "highly relevant to phobias, anxiety and post-traumatic stress disorders" and provided "compelling evidence" that a form of memory could be passed between generations. He commented: "It is high time public health researchers took human trans-generational responses seriously. "I suspect we will not understand the rise in neuropsychiatric disorders or obesity, diabetes and metabolic disruptions generally without taking a multigenerational approach."

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

How hummingbirds achieve their aerobatic feats

How hummingbirds achieve their aerobatic feats | Amazing Science | Scoop.it
The most detailed aerodynamic simulation of hummingbird flight conducted to date demonstrates that it achieves its aerobatic abilities through a unique set of aerodynamic forces.


The sight of a tiny hummingbird hovering in front of a flower and then darting to another with lightning speed amazes and delights. But it also leaves watchers with a persistent question: How do they do it?

Now, the most detailed, three-dimensional aerodynamic simulation of hummingbird flight conducted to date has definitively demonstrated that the hummingbird achieves its nimble aerobatic abilities through a unique set of aerodynamic forces that are more closely aligned to those found in flying insects than to other birds.


The new supercomputer simulation was produced by a pair of mechanical engineers at Vanderbilt University who teamed up with a biologist at the University of North Carolina at Chapel Hill. It is described in the article “Three-dimensional flow and lift characteristics of a hovering ruby-throated hummingbird” published this fall in the Journal of the Royal Society Interface.


For some time researchers have been aware of the similarities between hummingbird and insect flight, but some experts have supported an alternate model which proposed that hummingbird’s wings have aerodynamic properties similar to helicopter blades. However, the new realistic simulation demonstrates that the tiny birds make use of unsteady airflow mechanisms, generating invisible vortices of air that produce the lift they need to hover and flit from flower to flower.


You might think that if the hummingbird simply beats its wings fast enough and hard enough it can push enough air downward to keep its small body afloat. But, according to the simulation, lift production is much trickier than that. For example, as the bird pulls its wings forward and down, tiny vortices form over the leading and trailing edges and then merge into a single large vortex, forming a low-pressure area that provides lift. In addition, the tiny birds further enhance the amount of lift they produce by pitching up their wings (rotate them along the long axis) as they flap.


Hummingbirds perform another neat aerodynamic trick – one that sets them apart from their larger feathered relatives. They not only generate positive lift on the downstroke, but they also generate lift on the upstroke by inverting their wings. As the leading edge begins moving backwards, the wing beneath it rotates around so the top of the wing becomes the bottom and bottom becomes the top. This allows the wing to form a leading edge vortex as it moves backward generating positive lift.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Amazon frogs found to build mental maps of their surroundings with several hundred meters diameter

Amazon frogs found to build mental maps of their surroundings with several hundred meters diameter | Amazing Science | Scoop.it

Frogs, as we all know, lay eggs which eventually grow to become tadpoles. And tadpoles, because they have no legs, need water to survive. But the brilliant-thighed poison frog doesn't live in water, instead, it lives among leaf litter on the floor of the Amazonian rainforest. To keep their tadpoles alive, the adults carry them from puddle to puddle on their backs. Thus, the frogs need to know the location of all the puddles in their little part of world. Somehow, it seems, they build mental maps that allow them to move from one water nursery to the next without deviating.


To better understand the frogs, the researchers fitted several of them with tiny transmitters that allowed for tracking every move the volunteer frogs made. Then, they placed the frogs in different parts of the forest to see how well they did in finding their way back to where they lived. Remarkably, the researchers found that if the frogs were placed within a certain familiar range they were able to march straight back to their home without having to even pause or look around. Frogs that were placed in unfamiliar terrain on the other hand, became lost for awhile and had to work to get home. The researchers found that the range for familiar territory ranged at least up to 100 meters from where the frogs called home, though prior research has shown that such frogs typically roam in a circular area roughly 600 meters in diameter.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Body's bacteria may keep our brains healthy and the blood-brain barrier intact

Body's bacteria may keep our brains healthy and the blood-brain barrier intact | Amazing Science | Scoop.it

The microbes that live in your body outnumber your cells 10 to one. Recent studies suggest these tiny organisms help us digest food and maintain our immune system. Now, researchers have discovered yet another way microbes keep us healthy: They are needed for closing the blood-brain barrier, a molecular fence that shuts out pathogens and molecules that could harm the brain.


The findings suggest that a woman's diet or exposure to antibiotics during pregnancy may influence the development of this barrier. The work could also lead to a better understanding of multiple sclerosis, in which a leaky blood-brain barrier may set the stage for a decline in brain function.


The first evidence that bacteria may help fortify the body’s biological barriers came in 2001. Researchers discovered that microbes in the gut activate genes that code for gap junction proteins, which are critical to building the gut wall. Without these proteins, gut pathogens can enter the bloodstream and cause disease.


In the new study, intestinal biologist Sven Pettersson and his postdoc Viorica Braniste of the Karolinska Institute in Stockholm decided to look at the blood-brain barrier, which also has gap junction proteins. They tested how leaky the blood-brain barrier was in developing and adult mice. Some of the rodents were brought up in a sterile environment and thus were germ-free, with no detectable microbes in their bodies. Braniste then injected antibodies—which are too big to get through the blood-brain barrier—into embryos developing within either germ-free moms or moms with the typical microbes, or microbiota.


The studies showed that the blood-brain barrier typically forms a tight seal a little more than 17 days into development. Antibodies infiltrated the brains of all the embryos younger than 17 days, but they continued to enter the brains of embryos of germ-free mothers well beyond day 17, the team reports online today in Science Translational Medicine. Embryos from germ-free mothers also had fewer intact gap junction proteins, and gap junction protein genes in their brains were less active, which may explain the persistent leakiness.

more...
Vloasis's curator insight, November 22, 11:04 AM

So basically, embryos from germ-free mothers did not develop as efficiently, or as well?

Scooped by Dr. Stefan Gruenwald
Scoop.it!

CERN makes its data from real collision events available to the public for the first time

CERN makes its data from real collision events available to the public for the first time | Amazing Science | Scoop.it

Today CERN launched its Open Data Portal, which makes data from real collision events produced by LHC experiments available to the public for the first time. “Data from the LHC program are among the most precious assets of the LHC experiments, that today we start sharing openly with the world,” says CERN Director General Rolf Heuer. “We hope these open data will support and inspire the global research community, including students and citizen scientists.”


The LHC collaborations will continue to release collision data over the coming years. The first high-level and analyzable collision data openly released come from the CMS experiment and were originally collected in 2010 during the first LHC run. Open source software to read and analyze the data is also available, together with the corresponding documentation. The CMS collaboration is committed to releasing its data three years after collection, after they have been thoroughly studied by the collaboration.


“This is all new and we are curious to see how the data will be re-used,” says CMS data preservation coordinator Kati Lassila-Perini. “We’ve prepared tools and examples of different levels of complexity from simplified analysis to ready-to-use online applications. We hope these examples will stimulate the creativity of external users.”

In parallel, the CERN Open Data Portal gives access to additional event data sets from the ALICE, ATLAS, CMS and LHCb collaborations that have been prepared for educational purposes. These resources are accompanied by visualization tools.


All data on OpenData.cern.ch are shared under a Creative Commons CC0 public domain dedication. Data and software are assigned unique DOI identifiers to make them citable in scientific articles. And software is released under open source licenses. The CERN Open Data Portal is built on the open-source Invenio Digital Library software, which powers other CERN Open Science tools and initiatives.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Lingua Extraterrestris: How To Effectively Communicate Across The Cosmos [16 Videos Lectures]

Lingua Extraterrestris: How To Effectively Communicate Across The Cosmos [16 Videos Lectures] | Amazing Science | Scoop.it

The ultimate goal is to construct a message that another intelligence, completely unfamiliar with humankind, would be able to understand. It is assumed that the recipient is so far away that interaction in any reasonable time frame would be unfeasible, so the message must be entirely self-contained.


It has often been stated that mathematics would serve as a universal language, one suitable for communication between totally alien societies. SETI examines that statement in detail. While mathematics is often motivated by scientific applications, it is equally likely to arise from internal sources, sources that have nothing to do with the world of science.


Ample evidence suggests that people seek to inform future generations about their lives, times, and accomplishments. Earth is sprinkled liberally with time capsules, monuments, tombstones, and other tributes to ego, achievement, and in some cases folly. If an extraterrestrial intelligence should have the technological capacity to decode or at least receive an interstellar message, then it is highly probable that its society would be based on a reasonably high degree of cooperation among its members.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Researchers create 3-D stereoscopic plasmonic color prints with nanopixels

Researchers create 3-D stereoscopic plasmonic color prints with nanopixels | Amazing Science | Scoop.it

By designing nanopixels that encode two sets of information—or colors of light—within the same pixel, researchers have developed a new method for making 3D color prints. Each pixel can exhibit one of two colors depending on the polarization of the light used to illuminate it. So by viewing the pixels under light of both polarizations, two separate images can be seen. If the two images are chosen to be slightly displaced views of the same scene, viewing both simultaneously results in depth perception and the impression of a 3D stereoscopic image.


The researchers, led by Professor Joel K.W. Yang, at A*STAR (the Agency for Science, Technology and Research) in Singapore, the National University of Singapore, and the Singapore University of Technology and Design, have published a paper on the new technique for realizing 3D full-color stereoscopic prints in a recent issue of Nature Communications.

"We have created possibly the smallest-ever stereoscopic images using pixels formed from plasmonic nanostructures," Yang told Phys.org. "Such stereoscopic images do not require the viewer to don special glasses, but instead, the depth perception and 3D effect is created simply by viewing the print through an optical microscope coupled with polarizers."


The work is based on the concept of surface plasmon resonance: metal nanostructures can scatter different wavelengths (colors) of light due to the fact that the tiny nanostructures themselves resonate at different wavelengths. If a nanostructure is circular, its resonance is polarization-independent because the diameter of the circle is the same from all directions. However, if a nanostructure is biaxial (such as an ellipse or rectangle), its resonance will depend on the polarization of the incident light. By tailoring the exact dimensions of the biaxial nanopixels, researchers can generate different colors under different polarizations.


Building on these ideas, the researchers in the current study have demonstrated that polarization-sensitive nanopixels that encode two sets of information can be used to produce 3D stereoscopic microprints. To do this, the researchers created nanopixels out of tiny pieces of aluminum a hundred or so nanometers across. Because these shapes are biaxial, they exhibit plasmonic resonances at different wavelengths for each axis, with the colors determined almost entirely by the dimension of the axis parallel to the polarization direction. For example, a 130-nm x 190-nm elliptical pixel appears green under y-polarized light and purple under x-polarized light. Comparing the two pixel shapes, the researchers found that the elliptical pixels have a broader range of polarization-dependent colors, while the nanosquare dimer pixels have lower levels of cross-talk, minimizing unwanted mixing of colors.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Researchers print out self-learning robots

Researchers print out self-learning robots | Amazing Science | Scoop.it

When the robots of the future are set to extract minerals from other planets, they need to be both self-learning and self-repairing. Researchers at Oslo University have already succeeded in producing self-instructing robots on 3D printers.


“In the future, robots must be able to solve tasks in deep mines on distant planets, in radioactive disaster areas, in hazardous landslip areas and on the sea bed beneath the Antarctic. These environments are so extreme that no human being can cope. Everything needs to be automatically controlled. Imagine that the robot is entering the wreckage of a nuclear power plant. It finds a staircase that no-one has thought of. The robot takes a picture. The picture is analyzed. The arms of one of the robots is fitted with a printer. This produces a new robot, or a new part for the existing robot, which enables it to negotiate the stairs,” hopes Associate Professor Kyrre Glette who is part of the Robotics and intelligent systems research team at Oslo University’s Department of Informatics.


Even if Glette’s ideas remain visions of the future, the robotics team in the Informatics Building have already developed three generations of self-learning robots.


Professor Mats Høvin was the man behind the first model, the chicken-robot named “Henriette”, which received much media coverage when it was launched ten years ago. Henriette had to teach itself how to walk, and to jump over obstacles. And if it lost a leg, it had to learn, unaided, how to hop on the other leg.


A few years later, Masters student Tønnes Nygaard launched the second generation robot. At the same time, the Informatics team developed a simulation program that was able to calculate what the body should look like. Just as for Henriette, its number of legs was pre-determined, but the computer program was at liberty to design the length of the legs and the distance between them.


The third generation of robots brings even greater flexibility. The simulation programme takes care of the complete design and suggests the optimal number of legs and joints.


Simulation is not enough. In order to test the functionality of the robots, they need to undergo trials in the real world. The robots are produced as printouts from a 3D printer. “Once the robots have been printed, their real-world functionalities quite often prove to be different from those of the simulated versions. We are talking of a reality gap. There will always be differences. Perhaps the floor is more slippery in reality, meaning that the friction coefficient will have to be changed. We are therefore studying how the robots deteriorate from simulation to laboratory stage,” says Mats Høvin.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Human climbing with efficiently scaled gecko-inspired dry adhesive

Human climbing with efficiently scaled gecko-inspired dry adhesive | Amazing Science | Scoop.it

Geckos are, objectively, way better at climbing stuff than people. Our big sweaty meathooks are no match for the wall-scaling optimized toe pads of a small lizard. That's why a team at Stanford University is busy making gloves that simulate the sticky grip of the gecko.


The Stanford team's secret ingredient for truly adhesive gecko-inspired hand pads is a type of silicone material called polydimethylsiloxane, which they layer as microscopic wedges. These wedges use something called van der Waals force to keep the wearer upright, which is exactly how geckos manage to crawl across ceilings without falling to a splatter. Right now, the synthetic pads only work on smooth surfaces like plastic and glass, so would-be Spidermen still can't outperform the gecko if they try to climb something rougher.


DARPA is working on a similar make-people-climb-like-geckos project, with special gecko-inspired paddles that also let people sidle up walls like a lizard. The Stanford team collaborated with DARPA here, too, but published more details about their results. The researchers believe this material could be useful in helping astronauts grab space debris, so really, what we're talking about here is just trying to avoid any of the plot points in Gravitybecoming a horrible reality.


more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Worldwide agriculture plays a big role on seasonal CO2 swings in atmosphere

Worldwide agriculture plays a big role on seasonal CO2 swings in atmosphere | Amazing Science | Scoop.it
In a study that identifies a new, "direct fingerprint" of human activity on Earth, scientists have found that agricultural crops play a big role in seasonal swings of carbon dioxide in the atmosphere.

The new findings from Boston University, the University of Michigan and other institutions reveal a nuance in the carbon cycle that could help scientists understand and predict how Earth's vegetation will react as the globe warms.

Agriculture amplifies carbon dioxide fluctuations that happen every year. Plants suck up CO2 in the spring and summer as they blossom. Then they release it in the fall and winter as they decompose.

The study authors point out that these seasonal effects are distinct from the overall upward trend in CO2 levels that's the main culprit of climate change. While farming does contribute to that upward trend, the seasonal swings themselves don't.

"A simple picture is that plants breathe. You can see the seasonal impact of this in the Keeling curve, the famous graph that shows atmospheric CO2 levels measured from a mountaintop in Hawaii since the late 1950s," said Eric Kort, assistant professor in the U-M Department of Atmospheric, Oceanic and Space Sciences and a co-author the study, published this week in Nature.
more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Launching in 2015: A Certificate Authority to Encrypt the Entire Web

Launching in 2015: A Certificate Authority to Encrypt the Entire Web | Amazing Science | Scoop.it

Today EFF is pleased to announce Let’s Encrypt, a new certificate authority (CA) initiative that we have put together with Mozilla, Cisco, Akamai, IdenTrust, and researchers at the University of Michigan that aims to clear the remaining roadblocks to transition the Web from HTTP to HTTPS.


Although the HTTP protocol has been hugely successful, it is inherently insecure. Whenever you use an HTTP website, you are always vulnerable to problems, including account hijacking and identity theft; surveillance and tracking by governmentscompanies, and both in concert; injection of malicious scripts into pages; and censorship that targets specific keywords orspecific pages on sites. The HTTPS protocol, though it is not yet flawless, is a vast improvement on all of these fronts, and we need to move to a future where every website is HTTPS by default.With a launch scheduled for summer 2015, the Let’s Encrypt CA will automatically issue and manage free certificates for any website that needs them. Switching a webserver from HTTP to HTTPS with this CA will be as easy as issuing one command, or clicking one button.


The biggest obstacle to HTTPS deployment has been the complexity, bureaucracy, and cost of the certificates that HTTPS requires. We’re all familiar with the warnings and error messages produced by misconfigured certificates. These warnings are a hint that HTTPS (and other uses of TLS/SSL) is dependent on a horrifyingly complex and often structurally dysfunctional bureaucracy for authentication.


The need to obtain, install, and manage certificates from that bureaucracy is the largest reason that sites keep using HTTP instead of HTTPS. In our tests, it typically takes a web developer 1-3 hours to enable encryption for the first time. The Let’s Encrypt project is aiming to fix that by reducing setup time to 20-30 seconds. You can help test and hack on the developer preview of our Let's Encrypt agent software.


Let’s Encrypt will employ a number of new technologies to manage secure automated verification of domains and issuance of certificates. We will use a protocol we’re developing called ACME between web servers and the CA, which includes support for new and stronger forms of domain validation. We will also employ Internet-wide datasets of certificates, such as EFF’s own Decentralized SSL Observatory, the University of Michigan’s scans.io, and Google'sCertificate Transparency logs, to make higher-security decisions about when a certificate is safe to issue.


The Let’s Encrypt CA will be operated by a new non-profit organization called the Internet Security Research Group (ISRG). EFF helped to put together this initiative with Mozilla and the University of Michigan, and it has been joined for launch by partners including Cisco, Akamai, and Identrust.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Genomically encoded analog memory with precise in vivo DNA writing using living bacteria populations

Genomically encoded analog memory with precise in vivo DNA writing using living bacteria populations | Amazing Science | Scoop.it

MIT engineers have transformed the genome of the bacterium E. coli into a long-term storage device for memory. They envision that this stable, erasable, and easy-to-retrieve memory will be well suited for applications such as sensors for environmental and medical monitoring.“You can store very long-term information,” says Timothy Lu, an associate professor of electrical engineering and computer science and biological engineering. “You could imagine having this system in a bacterium that lives in your gut, or environmental bacteria. You could put this out for days or months, and then come back later and see what happened at a quantitative level.


”The new strategy, described in the Nov. 13, 2014 issue of the journal Science ("Genomically encoded analog memory with precise in vivo DNA writing in living cell populations"), overcomes several limitations of existing methods for storing memory in bacterial genomes, says Lu, the paper’s senior author. Those methods require a large number of genetic regulatory elements, limiting the amount of information that can be stored.The earlier efforts are also limited to digital memory, meaning that they can record only all-or-nothing memories, such as whether a particular event occurred. Lu and graduate student Fahim Farzadfard, the paper’s lead author, set out to create a system for storing analog memory, which can reveal how much exposure there was, or how long it lasted. To achieve that, they designed a “genomic tape recorder” that lets researchers write new information into any bacterial DNA sequence.

The researchers showed that SCRIBE enables the recording of arbitrary transcriptional inputs into DNA storage registers in living cells by translating regulatory signals into ssDNAs. In E. coli, they expressed ssDNAs from engineered retrons that use a reverse transcriptase protein to produce hybrid RNA-ssDNA molecules. These intracellularly expressed ssDNAs are targeted into specific genomic loci where they are recombined and converted into permanent memory. The team could show that genomically stored information can be readily reprogrammed by changing the ssDNA template and controlled via both chemical and light inputs. This demonstrates that genomically encoded memory can be read with a variety of techniques, including reporter genes, functional assays, and high-throughput DNA sequencing.

SCRIBE enables the recording of analog information such as the magnitude and time span of exposure to an input. This convenient feature is facilitated by the intermediate recombination rate of our current system (~10–4 recombination events per generation), which we validated via a mathematical model and computer simulations. For example, the scientists stored the overall exposure time to chemical inducers in the DNA memory of bacterial populations for 12 days (~120 generations), independently of the induction pattern. The frequency of mutants in these populations was linearly related to the total exposure time. Furthermore, they were able to demonstrate that SCRIBE-induced mutations can be written and erased and can be used to record multiple inputs across the distributed genomic DNA of bacterial populations.

Finally, they could show that SCRIBE memory can be decomposed into independent “input,” “write,” and “read” operations and used to create genetic “logic-and-memory” circuits, as well as “sample-and-hold” circuits.

Conclusion: SCRIBE is a scalable platform that uses genomic DNA for analog, rewritable, and flexible memory distributed across living cell populations. The scientists anticipate that SCRIBE will enable long-term cellular recorders for environmental and biomedical applications. Future optimization of recombination efficiencies achievable by SCRIBE could lead to more efficient single-cell digital memories and enhanced genome engineering technologies. Furthermore, the ability to regulate the generation of arbitrary targeted mutations with other gene-editing technologies should enable genomically encoded memory in additional organisms.
more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Life’s extremists may be an untapped source of antibacterial drugs

Life’s extremists may be an untapped source of antibacterial drugs | Amazing Science | Scoop.it

One of the most mysterious forms of life may turn out to be a rich and untapped source of antibacterial drugs. The mysterious life form is Archaea, a family of single-celled organisms that thrive in environments like boiling hydrothermal pools and smoking deep sea vents which are too extreme for most other species to survive.


“It is the first discovery of a functional antibacterial gene in Archaea,” said Seth Bordenstein, the associate professor of biological sciences at Vanderbilt University who directed the study, “You can’t overstate the significance of the antibiotic resistance problem that humanity is facing. This discovery should help energize the pursuit for new antibiotics in this underexplored group of life.”


Until the late 1970s, biologists thought that Archaea were just weird bacteria, but then a landmark analysis of their DNA showed that they represent an independent branch on the tree of life that stretches back more than three billion years. The realization that Archaea could be a source of novel pharmaceuticals emerges from a study of widespread horizontal gene transfer between different species conducted by a team of scientists from Vanderbilt University and Portland State University in Oregon.


more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Babies' brains adjust to listening to a language, even if they never learn it.

Babies' brains adjust to listening to a language, even if they never learn it. | Amazing Science | Scoop.it

Our brains start soaking in details from the languages around us from the moment we can hear them. One of the first things infants learn of their native languages is the system of consonants and vowels, as well as other speech sound characteristics, like pitch. In the first year of life, a baby’s ear tunes in to the particular set of sounds being spoken in its environment, and the brain starts developing the ability to tell subtle differences among them—a foundation that will make a difference in meaning down the line, allowing the child to learn words and grammar.


But what happens if that child gets shifted into a different culture after laying the foundations of its first native language? Does it forget everything about that first language, or are there some remnants that remain buried in the brain?


According to a recent PNAS paper, the effects of very early language learning are permanently etched into the brain, even if input from that language stops and it’s replaced by another language. To identify this lasting influence, the researchers used functional magnetic resonance imaging (fMRI) scans on children who had been adopted to see what neural patterns could be identified years after adoption.


Because not all linguistic features have easily identifiable effects on the brain, the researchers decided to focus on lexical tone. This is a feature found in some languages that allows a single arrangement of consonants and vowels to have different meanings that are distinguished by a change in pitch. For example, in Mandarin Chinese, the word “ma” with a rising tone means “hemp”—the same syllable with a falling tone means “scold.”


People who speak tone languages have differences in brain activity in a certain region of the brain’s left hemisphere. This region activates in response to pitch differences that are used to convey a difference in linguistic meaning; non-linguistic pitch is processed in the right hemisphere. Tone information is learned very early in life: infants learning Chinese languages (including Mandarin and Cantonese) show signs of recognizing tonal contrasts as early as four months.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

CrAssphage: Previously Unknown Ancient Gut Virus Lives in Half of World's Population

CrAssphage: Previously Unknown Ancient Gut Virus Lives in Half of World's Population | Amazing Science | Scoop.it

CrAssphage is a bacteriophage (also known as phages or bacterial viruses), a member of a group of viruses that infect bacteria.

Prof Edwards and his colleagues named this virus after the Cross-Assembly (CrAss) software program used to discover it.

Interestingly, CrAssphage was discovered entirely by accident.

While sifting through data from previous studies on gut-inhabiting viruses, the virologists noticed an unusual cluster of viral DNA – about 97,000 base pairs long.


When they checked this discovery against a comprehensive listing of known viruses, they came up empty. They then screened for CrAssphage across the database of the NIH’s Human Microbiome Project, and Argonne National Laboratory’s MG-RAST database, and again found it in abundance in samples.


To prove that CrAssphage they discovered in their data actually exists in nature, the researchers used DNA amplification technique to locate the virus in the original samples used to build NIH’s database.


“So we have a biological proof that the virus they found with the computer actually exists in the samples. This was a new virus that about half the sampled people had in their bodies that nobody knew about,” said Dr John Mokili of San Diego State University, who is a co-author of the paper describing the discovery in the journal Nature Communications.


The fact that CrAssphage is so widespread indicates that it probably isn’t a particularly young virus, either. “As far as we can tell, it’s as old as humans are. We’ve basically found it in every population we’ve looked at,” Prof Edwards said. According to the scientists, CrAssphage infects one of the most common types of gut bacteria, Bacteroidetes.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

New species glowworm found in Peruvian rainforest

New species glowworm found in Peruvian rainforest | Amazing Science | Scoop.it

Wildlife photographer Jeff Cremer has discovered what appears to be a new type of bioluminescent larvae. He told members of the press recently that he was walking near a camp in the Peruvian rainforest at night a few years ago, when he came upon a side of exposed earth upon which there were many little green glowing dots. Taking a closer look, he found that each dot was in fact the glowing head of a worm of some sort. He posted pictures of what he'd found on Reddit which were eventually spotted by entomologist Aaron Pomerantz, with the Tambopata Research Center. After contacting Cremer, Pomerantz made a pilgrimage to see the worms, gathered some samples and set to work studying them. Shortly thereafter, he determined that the worms were the larvae of an unknown type of beetle, likely a type of click beetle.

Further study of the half inch long larvae revealed that the photoluminescence served just a single purpose, attracting prey. They would sit waiting with their jaws spread wide open. When the light they were emitting attracted something, typically ants or termites, the jaws would snap shut capturing the bug thus providing a meal. Pomerantz collected several samples of the larvae and took them back to a lab where they were tested—he and his colleagues found the larvae would snap shut on just about any bug that touched its jaws.


Entomologists still don't know what kind of beetle the larvae would grow into, but are determined to find out—they aren't even sure if they are from known species. There are a lot of different kinds of click beetles, approximately 10,000 species, about 200 of which are known to be bioluminescent. The entomologists believe the larvae get their luminescence from a molecule called Luciferin, which is also found in the compound used by fireflies to light up the night sky.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

First look at nuclear fuel in a meltdown scenario

First look at nuclear fuel in a meltdown scenario | Amazing Science | Scoop.it

Scientists have managed to take their first close-up look at what happens to nuclear fuel when it becomes molten, as it would in a nuclear reactor meltdown. In an innovative lab experiment, they discovered that uranium dioxide fuel behaves differently when molten than in its solid state.


The findings, reported in the journal Science, may help researchers improve safety at nuclear power plants, by better understanding uranium dioxide's behaviour under extreme temperatures.


"In extreme events like Fukushima and Chernobyl the uranium dioxide literally melts, and we wanted to study the material to really understand it," says the paper's lead author Dr Lawrie Skinner of Stony Brook University in New York. "We can now pin down a little bit more accurately what the properties and temperature of the melt will be. Any sensible reactor design should take into account the real structure, physical properties, and behavior of this melt."


Until now, the extreme heat and radiation has made it impossible for scientists to study uranium dioxide's characteristics and structure in a molten state. Uranium dioxide melts at over 3000°C, far too hot for most furnace container materials which would melt and react with the test samples.


Skinner and colleagues got around the container problem by floating a tiny 3 millimeter bead of uranium dioxide in a gas stream and heating it with a laser. They were able to study the relative positions of the atoms in both hot solid and molten uranium dioxide beads using high energy synchrotron X-ray diffraction. "We didn't really know what to expect, it's not something we've measured before," says Skinner.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Imagination and reality flow in opposite directions in the brain

Imagination and reality flow in opposite directions in the brain | Amazing Science | Scoop.it

As real as that daydream may seem, its path through your brain runs opposite reality. Aiming to discern discrete neural circuits, researchers at the University of Wisconsin-Madison have tracked electrical activity in the brains of people who alternately imagined scenes or watched videos.


"A really important problem in brain research is understanding how different parts of the brain are functionally connected. What areas are interacting? What is the direction of communication?" says Barry Van Veen, a UW-Madison professor of electrical and computer engineering. "We know that the brain does not function as a set of independent areas, but as a network of specialized areas that collaborate."


Van Veen, along with Giulio Tononi, a UW-Madison psychiatry professor and neuroscientist, Daniela Dentico, a scientist at UW-Madison's Waisman Center, and collaborators from the University of Liege in Belgium, published results recently in the journal NeuroImage. Their work could lead to the development of new tools to help Tononi untangle what happens in the brain during sleep and dreaming, while Van Veen hopes to apply the study's new methods to understand how the brain uses networks to encode short-term memory.


During imagination, the researchers found an increase in the flow of information from the parietal lobe of the brain to the occipital lobe -- from a higher-order region that combines inputs from several of the senses out to a lower-order region. In contrast, visual information taken in by the eyes tends to flow from the occipital lobe -- which makes up much of the brain's visual cortex -- "up" to the parietal lobe.


"There seems to be a lot in our brains and animal brains that is directional, that neural signals move in a particular direction, then stop, and start somewhere else," says. "I think this is really a new theme that had not been explored."


The researchers approached the study as an opportunity to test the power of electroencephalography (EEG) -- which uses sensors on the scalp to measure underlying electrical activity -- to discriminate between different parts of the brain's network.

Brains are rarely quiet, though, and EEG tends to record plenty of activity not necessarily related to a particular process researchers want to study.


To zero in on a set of target circuits, the researchers asked their subjects to watch short video clips before trying to replay the action from memory in their heads. Others were asked to imagine traveling on a magic bicycle -- focusing on the details of shapes, colors and textures -- before watching a short video of silent nature scenes.

Using an algorithm Van Veen developed to parse the detailed EEG data, the researchers were able to compile strong evidence of the directional flow of information.


"We were very interested in seeing if our signal-processing methods were sensitive enough to discriminate between these conditions," says Van Veen, whose work is supported by the National Institute of Biomedical Imaging and Bioengineering. "These types of demonstrations are important for gaining confidence in new tools."

more...
Vloasis's curator insight, November 22, 11:10 AM

So imagination input flows from the parietal to the occipital lobe, while visual input flows vice versa.

Diane Johnson's curator insight, November 23, 8:46 AM

Interesting findings from electrical and computer engineering studies. Useful connections to the information processing DCI's.

Scooped by Dr. Stefan Gruenwald
Scoop.it!

Physicists study magnetism with the roles of position and momentum reversed

Physicists study magnetism with the roles of position and momentum reversed | Amazing Science | Scoop.it

Normally, the strength of a magnetic field increases as you get closer to a magnet and decreases as you move further away—a concept easily understood when placing magnets near a refrigerator, for instance. But recent research has shown that exotic "momentum-space artificial magnetic fields" can be created where the strength of the magnetic field depends on how fast a particle moves, instead of where the particle is. In other words, the roles of position and momentum are swapped.


Now in a new paper, physicists have explored these ideas further, especially at the quantum level. They show how current experiments can be modified to study the motion of a quantum particle in a momentum-space magnetic field. They explain that these systems will be able to experimentally realize a "wonderland of new physics," such as magnetism on a torus, for the first time.


The physicists, Hannah M. Price, Tomoki Ozawa, and Iacopo Carusotto at the INO-CNR BEC Center and the University of Trento, Italy, have published their paper discussing momentum-space magnetism in a recent issue of Physical Review Letters.


"Magnetism is fundamental in many areas of physics, and it leads to many fascinating phenomena," Price told Phys.org. "Physicists use mathematical equations to capture the behavior of a quantum particle in a magnetic field. These equations have a particular, beautiful mathematical structure. But we can also reverse this logic. If we engineer or find an equation with this particular mathematical structure, the behavior of a particle will be like that of a particle in an 'artificial magnetic field,' even if the 'field' has a completely different underlying physical origin. As has been known for a long time, this beautiful mathematical structure can be found or created in many different physical contexts. This is a really powerful tool that physicists use to engineer and learn more about magnetism."


"We can either view our problem in terms of all the possible 'position states' of a particle or equally in terms of all the possible 'momentum states,'" Price explained. "Depending on the viewpoint we choose, our mathematical equations will have a different form, and so we usually choose the viewpoint that gives us the easiest equations to solve and understand. The beautiful mathematical structure described above appears when we have a magnetic field and we look at our equations in terms of 'position states.' "However, what if we could find equations in terms of 'momentum states' that had an analogous mathematical structure? Then we could draw an analogy with magnetism: we would get the same quantum physics but where the 'position' must be swapped everywhere with the 'momentum.' "The equations could be understood as describing a particle in an 'artificial momentum-space magnetic field.'"

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Alternative to the Turing test: The Lovelace 2.0 Test

Alternative to the Turing test: The Lovelace 2.0 Test | Amazing Science | Scoop.it

Georgia Tech associate professor Mark Ried has developed a new kind of “Turing test” — a test proposed in 1950 by computing pioneer Alan Turing to determine whether a machine or computer program exhibits human-level intelligence.Most Turing test designs require a machine to engage in dialogue and convince (trick) a human judge that it is an actual person. But creating certain types of art also requires intelligence, leading Reid to consider if that approach might lead to a better gauge of whether a machine can replicate human thought.


“It’s important to note that Turing never meant for his test to be the official benchmark as to whether a machine or computer program can actually think like a human,” Riedl said. “And yet it has, and it has proven to be a weak measure because it relies on deception. This proposal suggests that a better measure would be a test that asks an artificial agent to create an artifact requiring a wide range of human-level intelligent capabilities.”


Here are the basic test rules:


  • The artificial agent passes if it develops a creative artifact from a subset of artistic genres deemed to require human-level intelligence and the artifact meets certain creative constraints given by a human evaluator.
  • The human evaluator must determine that the object is a valid representative of the creative subset and that it meets the criteria. (The created artifact needs only meet these criteria — it does not need to have any aesthetic value.)
  • A human referee must determine that the combination of the subset and criteria is not an impossible standard.


The Lovelace 2.0 Test stems from the original Lovelace* Test as proposed by Bringsjord, Bello and Ferrucci in 2001. The original test required that an artificial agent produce a creative item in such a way that the agent’s designer cannot explain how it developed the creative item. The item, thus, must be created in such a way that is valuable, novel and surprising.


Riedl contends that the original Lovelace test does not establish clear or measurable parameters. Lovelace 2.0, however, enables the evaluator to work with defined constraints without making value judgments such as whether the artistic object created surprise.

Riedl’s paper, available here, will be presented at Beyond the Turing Test, an Association for the Advancement of Artificial Intelligence (AAAI) workshop to be held January 25–29, 2015, in Austin, Texas.


more...
Carlos Garcia Pando's comment, November 21, 3:59 AM
Is it a better machine for the tasks of machines if it passes the Lovelace 2.0 test? It proves the machine can imitate certain human habilities, but I expect the machines to surpass us humans on our weaknesses and limitations.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

The Fountain of Youth is Closer Than We Think

The Fountain of Youth is Closer Than We Think | Amazing Science | Scoop.it


In a recent TEDx talk Human Longevity Inc.'s Dr. Robert Hariri tells how stem cells may be the secret scientific ingredient that enables humans to live younger longer. Human Longevity Inc, which was recently formed with J. Craig Venter and Peter Diamandis will use both genomics and stem cell therapies to find treatments that allow aging adults to stay healthy and functional for as long as possible. "I believe that aging is a stem cell problem, related to a shift in the balance of undifferentiated, versatile to differentiated, specialized cells," says Hariri. 

He talks of how bone marrow recipients and plastic surgery patients that have had adipose tissue injections can  achieve more youthful characteristics thanks to the introduction of stem cells into the affected areas, and the important proteins that they produce. "I think the solution here is to recharge the regenerative engine by replenishing the reservoir of stem cells that can restore that synthetic versatility," he claims.

Hariri concludes his talk by saying that, "The future use of stem cells can benefit from a new model describing functional similarities to computers." In this conception, the biological software resides in the DNA of the cell's nucleus; the cytosolic organelles that produce the proteins are the processor and the cell membrane with it's numerous receptors, serves as the keyboard. "Reprogramming the biological software of stem cells is already happening and provides a platform for controlling their fate and behavior for biomedical purposes including longevity," concludes Hariri. He is a surgeon, biomedical scientist and highly successful serial entrepreneur in two technology sectors: biomedicine and aerospace. The Chairman, Founder, Chief Scientific Officer, and former Chief Executive Officer of Celgene Cellular Therapeutics, one of the world’s largest human cellular therapeutics companies, Dr. Hariri has pioneered the use of stem cells to treat a range of life threatening diseases and has made transformative contributions in the field of tissue engineering.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Spooky Alignment of Rotational Axes of Quasars Across Billions of Light-years

Spooky Alignment of Rotational Axes of Quasars Across Billions of Light-years | Amazing Science | Scoop.it

New observations with ESO’s Very Large Telescope (VLT) in Chile have revealed alignments over the largest structures ever discovered in the Universe. A European research team has found that the rotation axes of the central supermassive black holes in a sample of quasars are parallel to each other over distances of billions of light-years. The team has also found that the rotation axes of these quasars tend to be aligned with the vast structures in the cosmic web in which they reside.

Quasars are galaxies with very active supermassive black holes at their centres. These black holes are surrounded by spinning discs of extremely hot material that is often spewed out in long jets along their axes of rotation. Quasars can shine more brightly than all the stars in the rest of their host galaxies put together.


A team led by Damien Hutsemékers from the University of Liège in Belgium used the FORS instrument on the VLT to study 93 quasars that were known to form huge groupings spread over billions of light-years, seen at a time when the Universe was about one third of its current age.


The first odd thing we noticed was that some of the quasars’ rotation axes were aligned with each other — despite the fact that these quasars are separated by billions of light-years,” said Hutsemékers. The team then went further and looked to see if the rotation axes were linked, not just to each other, but also to the structure of the Universe on large scales at that time.


When astronomers look at the distribution of galaxies on scales of billions of light-years they find that they are not evenly distributed. They form a cosmic web of filaments and clumps around huge voids where galaxies are scarce. This intriguing and beautiful arrangement of material is known as large-scale structure.


The new VLT results indicate that the rotation axes of the quasars tend to be parallel to the large-scale structures in which they find themselves. So, if the quasars are in a long filament then the spins of the central black holes will point along the filament. The researchers estimate that the probability that these alignments are simply the result of chance is less than 1%.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Possible orphan black hole lies just 90 million light-years from Earth

Possible orphan black hole lies just 90 million light-years from Earth | Amazing Science | Scoop.it

An unusual object about 90 million light-years from Earth might be a supermassive black hole kicked out of its home galaxy during a collision with another galaxy, a new study suggests. If so, it’s the first evictee to be confirmed as such by astronomers. The object, dubbed SDSS1133, lies about 2600 light-years from the center of a dwarf galaxy known as Markarian 177, both of which lie within the bowl of the Big Dipper, a familiar star pattern in the constellation Ursa Major.


SDSS1133 has brightened substantially over the past 2 years but has been spotted in images taken by various instruments during the past 63 years, hinting that the object—whose brightest features measure less than 40 light-years across—probably isn’t a recently exploded supernova. Recent observations of Markarian 177 reveal specific areas of intense star formation, possible signs of a recent galactic collision that expelled SDSS1133 from the parent galaxy where it once resided, the researchers reported online before print in the Monthly Notices of the Royal Astronomical Society. The video depicts the purported 2.7-billion-year-long intergalactic collision and its aftermath. According to an alternate scenario, SDSS1133 is an extraordinarily rare type of massive star called a luminous blue variable. But if that’s the case, the researchers note, SDSS1133’s near-continual eruption since 1950 would be the most persistent yet reported for that type of star. A series of observations in ultraviolet wavelengths planned for next year may help scientists distinguish between these widely disparate explanations.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Of the difference between mouse and man: A comparative encyclopedia of DNA elements in the mouse genome

Of the difference between mouse and man: A comparative encyclopedia of DNA elements in the mouse genome | Amazing Science | Scoop.it

The laboratory mouse shares the majority of its protein-coding genes with humans, making it the premier model organism in biomedical research, yet the two mammals differ in significant ways. To gain greater insights into both shared and species-specific transcriptional and cellular regulatory programs in the mouse, the Mouse ENCODE Consortium has mapped transcription, DNase I hypersensitivity, transcription factor binding, chromatin modifications and replication domains throughout the mouse genome in diverse cell and tissue types. By comparing with the human genome, the scientists could not only confirm substantial conservation in the newly annotated potential functional sequences, but also find a large degree of divergence of sequences involved in transcriptional regulation, chromatin state and higher order chromatin organization. These results illuminate the wide range of evolutionary forces acting on genes and their regulatory regions, and provide a general resource for research into mammalian biology and mechanisms of human diseases.


Advances in DNA sequencing technologies have led to the development of RNA-seq (RNA sequencing), DNase-seq (DNase I hypersensitive sites sequencing), ChIP-seq (chromatin immunoprecipitation followed by DNA sequencing), and other methods that allow rapid and genome-wide analysis of transcription, replication, chromatin accessibility, chromatin modifications and transcription factor binding in cells11. Using these large-scale approaches, the ENCODE consortium has produced a catalog of potential functional elements in the human genome12. Notably, 62% of the human genome is transcribed in one or more cell types13, and 20% of human DNA is associated with biochemical signatures typical of functional elements, including transcription factor binding, chromatin modification and DNase hypersensitivity. The results support the notion that nucleotides outside the mammalian-conserved genomic regions could contribute to species-specific traits61214.


Now, teams of scientists have applied the same high-throughput approaches to over 100 mouse cell types and tissues15, producing a coordinated group of data sets for annotating the mouse genome. Integrative analyses of these data sets uncovered widespread transcriptional activities, dynamic gene expression and chromatin modification patterns, abundant cis-regulatory elements, and remarkably stable chromosome domains in the mouse genome. The generation of these data sets also allowed an unprecedented level of comparison of genomic features of mouse and human. Described in the current article and companion works, these comparisons reveal both conserved sequence features and widespread divergence in transcription and regulation. Some of the key findings are:


  • Although much conservation exists, the expression profiles of many mouse genes involved in distinct biological pathways show considerable divergence from their human orthologues.
  • A large portion of the cis-regulatory landscape has diverged between mouse and human, although the magnitude of regulatory DNA divergence varies widely between different classes of elements active in different tissue contexts.
  • Mouse and human transcription factor networks are substantially more conserved than cis-regulatory DNA.
  • Species-specific candidate regulatory sequences are significantly enriched for particular classes of repetitive DNA elements.
  • Chromatin state landscape in a cell lineage is relatively stable in both human and mouse.
  • Chromatin domains, interrogated through genome-wide analysis of DNA replication timing, are developmentally stable and evolutionarily conserved.


To annotate potential functional sequences in the mouse genome, the scientists used ChIP-seq, RNA-seq and DNase-seq to profile transcription factor binding, chromatin modification, transcriptome and chromatin accessibility in a collection of 123 mouse cell types and primary tissues (Supplementary Tables). Additionally, to interrogate large-scale chromatin organization across different cell types, they also used a microarray-based technique to generate replication-timing profiles in 18 mouse tissues and cell types (Supplementary Table)16. Altogether, they produced over 1,000 data sets. The list of the data sets and all the supporting material for this manuscript are also available at website of the project: http://mouseencode.org.

more...
No comment yet.
Scooped by Dr. Stefan Gruenwald
Scoop.it!

Researchers Provide First Peek at How Neurons Multitask

Researchers Provide First Peek at How Neurons Multitask | Amazing Science | Scoop.it

Researchers at the University of Michigan have shown how a single neuron can perform multiple functions in a model organism, illuminating for the first time this fundamental biological mechanism and shedding light on the human brain.

Investigators in the lab of Shawn Xu at the Life Sciences Institute found that a neuron in C. elegans, a tiny worm with a simple nervous system used as a model for studying sensation, movement and other neurological function, regulates both the speed and direction in which the worm moves. The individual neurons can route information through multiple downstream neural circuits, with each circuit controlling a specific behavioral output.

The findings are scheduled for online publication in the journal Cell on Nov. 6. The research is also featured on the cover.

"Understanding how the nervous system and genes lead to behavior is a fundamental question in neuroscience, and we wanted to figure out how C. elegans are able to perform a wide range of complex behaviors with their small nervous systems," Xu said.

The C. elegans nervous system contains 302 neurons.

"Scientists think that even though humans have billions of neurons, some perform multiple functions. Seeing the mechanism in worms will help to understand the human brain," Xu said.

The model neuron studied, AIY, regulates at least two distinct motor outputs: locomotion speed and direction-switch. AIY interacts with two circuits, one that is inhibitory and controls changes in the direction of the worm's movement, and a second that is excitatory and controls speed.

"It's important to note that these two circuits have connections with other neurons and may cross-talk with each other," Xu said. "Neuronal control of behavior is very complex."

Xu is a faculty member in the U-M Life Sciences Institute, where his laboratory is located and research conducted. He is also a professor of molecular and integrative physiology at the U-M Medical School.

Other authors on the paper were Zhaoyu Li, Jie Liu and Maohua Zheng, also of the Life Sciences Institute and Department of Molecular and Integrative Physiology in the U-M Medical School.
The research was supported by the National Institutes of Health.
Shawn Xu: www.lsi.umich.edu/labs/shawn-xu-lab 

more...
No comment yet.