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'Junk DNA' Defines Differences Between Humans and Primates

Junk DNA
© The Daily Galaxy

Scientists believed for years that the vast phenotypic differences between humans and chimpanzees would display significantly different genetic makeups. However, when their genomes were later sequenced, researchers were surprised to learn that the DNA sequences of human and chimpanzee genes are nearly identical.

In molecular biology, "junk" DNA is a collective label for the portions of the DNA sequence of a chromosome or a genome for which no function has yet been identified. About 98.5% of the human genome has been designated as "junk", including most sequences within introns and most intergenic DNA.

While much of this sequence is probably an evolutionary artifact that serves no present-day purpose, some may function in ways that are not currently understood. In fact, recent studies have suggested functions for certain portions of what has been called junk DNA. Moreover, the conservation of some "junk" DNA over many millions of years of evolution may imply an essential function. The "junk" label is therefore recognized as something of a misnomer, and many prefer the more neutral term "noncoding DNA."

Beaker

Your DNA May Carry a 'Memory' of Your Living Conditions in Childhood

dna
© n/a
Family living conditions in childhood are associated with significant effects in DNA that persist well into middle age, according to new research by Canadian and British scientists.

The team, based at McGill University in Montreal, University of British Columbia in Vancouver and the UCL Institute of Child Health in London looked for gene methylation associated with social and economic factors in early life. They found clear differences in gene methylation between those brought up in families with very high and very low standards of living. More than twice as many methylation differences were associated with the combined effect of the wealth, housing conditions and occupation of parents (that is, early upbringing) than were associated with the current socio-economic circumstances in adulthood. (1252 differences as opposed to 545).

The findings, published online today in the International Journal of Epidemiology, could provide major evidence as to why the health disadvantages known to be associated with low socio-economic position can remain for life, despite later improvement in living conditions. The study set out to explore the way early life conditions might become 'biologically-embedded' and so continue to influence health, for better or worse, throughout life. The scientists decided to look at DNA methylation, a so-called epigenetic modification that is linked to enduring changes in gene activity and hence potential health risks. (Broadly, methylation of a gene at a significant point in the DNA reduces the activity of the gene.)

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Software Seamlessly Inserts New Objects Into Existing Photographs

Photography
© Kevin Karsch Real vs. Fake Images: A new, ultra-realistic object insertion method automatically accounts for lighting.

A simple programming tool can build a model of a scene in a two-dimensional photograph and insert a realistic-looking synthetic object into it. Unlike other augmented reality programs, it doesn't use any tags, props or laser scanners to model a scene's geometry - it just uses a small number of markers and accounts for lighting and depth. The result is an augmented scene with proper perspective, which looks so realistic that testers could not distinguish between an original photo and a modified one.

With just a single image and some annotation by a user, the program creates a physical model of a scene, as demonstrated in the video below.


Kevin Karsch, Varsha Hedau, David Forsyth and Derek Hoiem at the University of Illinois at Urbana-Champaign developed a new image composition algorithm to generate an accurate lighting model. It uses geometry to build upon existing light-estimation methods, and it can work with any type of rendering software, the researchers explain. It works by breaking down the scene's geometry and depth of field, and then determining how much of the scene's overall illumination is a result of reflection (albedo) and how much directly emanates from light fixtures. This provides light parameters that can be transposed onto an inserted object. The team has developed algorithms for interior lights and for external light sources, typically light shafts from the sun.

Blackbox

Last mystery of first recorded supernova laid to rest

NASA says it has put to rest any lingering doubts about the identity of the first recorded supernova, described in the Chinese historical work Book of the Later Han as having taken place in 185 A.D.

As strongly suspected by observations made by NASA's Chandra X-ray Observatory and the European Space Agency's XMM-Newton Observatory in 2006, the "guest star" sighted by Chinese astronomers 1,826 years ago is, indeed, the rather prosaically named RCW 86.

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© NASAData from all four space telescopes were combined to produce this image of RCW 86 (click to enlarge)
One scientist studying the supernova remnants in 2006, Jacco Vink of the University of Utrecht, said in 2006: "I think it is very interesting that we can now say with some confidence, but not absolute certainty, that RCW 86 is the remnant of A.D. 185."

NASA now says that all doubt has been removed. New observations made by NASA's Spitzer Space Telescope and Wide-field Infrared Survey Explorer, better know as WISE, have not only confirmed the earlier suspicions, but have determined that RCW 86 is a Type 1a supernova.

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Disruptive Sleep Disorder Affects the Left-Handed Differently

Sleep Issues
© Diego Cervo, ShutterstockA man struggles to sleep.

Whether you prefer to write with your right or left hand may influence your sleep, according to a new study that finds among people who have a sleep disorder that causes rhythmic movements in the night, the left-handed are more likely to move both sides of their body.

The findings suggest that the disorder, periodic limb movement disorder (PLMD), originates in the brain, not in the spinal cord as has been suggested, said study researcher Dawn Alita R. Hernandez, a professor of medicine at the University of Toledo Medical Center in Ohio.

"What we know of people who are left-handed is they tend to have a slightly different dominant brain hemisphere than right-handed people," Hernandez told LiveScience. "So if [PLMD] is coming primarily from the cortex, we should see a difference in handedness."

Laptop

Why Computer Voices are Mostly Female

woman + computer
© CNN
To most owners of the new iPhone, the voice-activated feature called Siri is more than a virtual "assistant" who can help schedule appointments, find a good nearby pizza or tell you if it's going to rain.

She's also a she.

Siri answers questions in a part-human, part-robot voice that's deep, briskly efficient and distinctly female. (At least in the U.S. and four other countries. In France and the UK, Siri is male.)

People describe the app using female pronouns. Her gender has even prompted some users to flood blogs and online forums with sexually suggestive questions for Siri such as "What are you wearing?" (Siri's baffled response: "Why do people keep asking me this?")

Bizarro Earth

What's the Largest Earthquake that Could Strike the United States?

Seismogram
© DreamstimeSeismogram.


Several earthquakes struck the United States Friday (Oct. 22), including a 4.0-magnitude quake near San Francisco, Calif., a 4.8-magnitude temblor in central Texas, and a 3.2-magnitude quake in Hawaii. Though experts say the small burst of seismic activity on U.S. soil isn't all that unusual, it has likely led some people to wonder how much worse things could get.

Extremely powerful earthquakes could happen in two places in the United States, scientists say: the Pacific Northwest and Alaska.

Geophysicists estimate that the Cascadia Subduction Zone, an intersection of tectonic plates just off the northwestern coast that stretches from the northern tip of California up to Canada, is capable of generating an earthquake with a magnitude as high as a 9.0.

The last time the area shook that hard was 300 years ago. "There were hardly any people living on the Pacific Northwest Coast in 1700," said Heidi Houston, a seismologist at the University of Washington's Department of Earth & Space Sciences. "But it generated a huge tsunami that traveled to Japan and destroyed coastal villages there. The Japanese records show that the causative earthquake could only be our Cascadia Subduction Zone and it had to have been a magnitude-9.0."

Fish

Giant Amoebas Discovered in Deepest Ocean Trench

Deploying the Dropcam
© Shelbi RandenburgNational Geographic Society Remote Imaging engineers Eric Berkenpas (bottom) and Graham Wilhelm prepare to deploy Dropcam.

Gigantic amoebas have been found in the Mariana Trench, the deepest region on Earth.

During a July 2011 voyage to the Pacific Ocean chasm, researchers with Scripps Institution of Oceanography at UC San Diego and National Geographic engineers deployed untethered landers, called dropcams, equipped with digital video and lights to explore the largely mysterious region of the deep sea.

The team documented the deepest known existence of xenophyophores, single-celled animals exclusively found in deep-sea environments. Xenophyophores are noteworthy for their size, with individual cells often exceeding 4 inches (10 centimeters), their extreme abundance on the seafloor and their role as hosts for a variety of organisms.


Meteor

Comets are raining down water on neighbouring Eta Corvi solar system

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© NASA/JPL-Caltech
The Eta Corvi solar system is like a window into how our own solar system looked billions of years ago. All of Eta Corvi is being bombarded by giant comets - the exact same process that created Earth's oceans.

What's more, observations by NASA's Spitzer telescope show signs of huge dust clouds close to the system's star. The most obvious way to create dust clouds like that is if a huge comet collided with a planet near the star. Analysis of the light coming from the dust suggests it's composed of water ice, organic compounds, and rock, all of which points very strongly to a big comet.

We can't be sure, but it's certainly possible that this comet actually hit a planet located in Eta Corvi's habitable zone. If that's the case, then we're witnessing what is essentially a reenactment of the formation of our planet's oceans. Earth got huge amounts of its water and carbon-based organic compounds during an epoch known as the Late Heavy Bombardment, in which comets from the Kuiper Belt beyond Neptune began hurtling towards the inner solar system due to gravitational disturbances from Jupiter and Saturn.

Arrow Down

Mainstream Science catching up: Most Planets' Oceans are Probably Seeded by Comets

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© NASA/JPL-CaltechArtist's concept illustrating an icy planet-forming disk around the star TW Hydrae, located about 175 light-years away in the constellation Hydra. Astronomers found huge stores of cool water vapor (illustrated in blue) in the frigid outer regions of the star system, where comets will take shape.
A still-forming alien solar system has enough water in its outer reaches to fill Earth's oceans several thousand times over, a new study finds.

The discovery marks the first time astronomers have detected water in a dusty planet-forming disk so far from its central star, in the frigid region where comets are born. Scientists think comet impacts delivered most of Earth's water, and the new study hints that alien planets may commonly acquire oceans in the same way.

"We now know that large amounts of water ice are available in planet-forming disks, ready to be incorporated in comets," said Michiel Hogerheijde, of Leiden Observatory in the Netherlands, the study's lead author. "Ultimately, some of this water may end up on Earth-like planets that form completely dry but this way may end up with life-supporting oceans."