Millions of human cells are constantly dividing to repair tissue damage and ensure continuity. This is one of the most complex cellular processes, and in order for it to be successful, cells must produce a copy of their genetic material (DNA). Researchers from the Spanish National Cancer Research Centre (CNIO) have discovered the critical role of the POLD3 protein in this DNA replication process; without POLD3, cells do not divide, and even the embryonic development process may be curtailed.

The study, published today in the printed version of the journal Molecular Cell, overthrows the hypothesis circulating in recent years that POLD3 might be important for tumour cells but not for healthy ones. On the basis of this hypothesis, a drug blocking POLD3 would be capable of eradicating the tumour with few or no side effects for patients.

Until today, experiments had only been conducted in vitro in the laboratory, without directly studying the effects of the protein on a live organism. However, through genetic engineering, the authors of this study produced POLD3 knockout mice, revealing the key role of this protein during cell replication.

Houston — Research by Rice University Earth scientists suggests that virtually all of Earth's life-giving carbon could have come from a collision about 4.4 billion years ago between Earth and an embryonic planet similar to Mercury.

In a new study this week in Nature Geoscience, Rice petrologist Rajdeep Dasgupta and colleagues offer a new answer to a long-debated geological question: How did carbon-based life develop on Earth, given that most of the planet's carbon should have either boiled away in the planet's earliest days or become locked in Earth's core?

"The challenge is to explain the origin of the volatile elements like carbon that remain outside the core in the mantle portion of our planet," said Dasgupta, who co-authored the study with lead author and Rice postdoctoral researcher Yuan Li, Rice research scientist Kyusei Tsuno and Woods Hole Oceanographic Institute colleagues Brian Monteleone and Nobumichi Shimizu.

Dasgupta's lab specializes in recreating the high-pressure and high-temperature conditions that exist deep inside Earth and other rocky planets. His team squeezes rocks in hydraulic presses that can simulate conditions about 250 miles below Earth's surface or at the core-mantle boundary of smaller planets like Mercury.

"Even before this paper, we had published several studies that showed that even if carbon did not vaporize into space when the planet was largely molten, it would end up in the metallic core of our planet, because the iron-rich alloys there have a strong affinity for carbon," Dasgupta said.

Earth's core, which is mostly iron, makes up about one-third of the planet's mass. Earth's silicate mantle accounts for the other two-thirds and extends more than 1,500 miles below Earth's surface. Earth's crust and atmosphere are so thin that they account for less than 1 percent of the planet's mass. The mantle, atmosphere and crust constantly exchange elements, including the volatile elements needed for life.

If Earth's initial allotment of carbon boiled away into space or got stuck in the core, where did the carbon in the mantle and biosphere come from?

"One popular idea has been that volatile elements like carbon, sulfur, nitrogen and hydrogen were added after Earth's core finished forming," said Li, who is now a staff scientist at Guangzhou Institute of Geochemistry, Chinese Academy of Sciences. "Any of those elements that fell to Earth in meteorites and comets more than about 100 million years after the solar system formed could have avoided the intense heat of the magma ocean that covered Earth up to that point.

Robotic weapons have become so advanced that top military experts in the US fear the plot of the sci-fi film 'Terminator' could come true.

Huge technological leaps forward in drones, artificial intelligence and autonomous weapon systems must be addressed before humanity is driven to extinction by mechanical overlords like in the 1984 Arnold Schwarzenegger classic, according to Pentagon chiefs.

Air Force General Paul Selva, the Vice Chairman of the Joint Chiefs of Staff at the US Defense Department, said so-called thinking weapons could lead to: "Robotic systems to do lethal harm... a Terminator without a conscience."

When asked about robotic weapons able to make their own decisions, he said: "Our job is to defeat the enemy" but "it is governed by law and by convention."

Neuroscientists at the University of Pittsburgh have identified the neural networks that connect the cerebral cortex to the adrenal medulla, which is responsible for the body's rapid response in stressful situations. These findings, reported in the online Early Edition of the journal Proceedings of the National Academy of Sciences (PNAS), provide evidence for the neural basis of a mind-body connection.

Specifically, the findings shed new light on how stress, depression and other mental states can alter organ function, and show that there is a real anatomical basis for psychosomatic illness. The research also provides a concrete neural substrate that may help explain why meditation and certain exercises such as yoga and Pilates can be so helpful in modulating the body's responses to physical, mental and emotional stress.

"Our results turned out to be much more complex and interesting than we imagined before we began this study," said senior author Peter L. Strick, Ph.D., Thomas Detre Chair of the Department of Neurobiology and scientific director of the University of Pittsburgh Brain Institute.

In their experiments, the scientists traced the neural circuitry that links areas of the cerebral cortex to the adrenal medulla (the inner part of the adrenal gland, which is located above each kidney). The scientific team included lead author Richard P. Dum, Ph.D., research associate professor in the Department of Neurobiology; David J. Levinthal, M.D., Ph.D., assistant professor in the Department of Medicine; and Dr. Strick.

Some humans just know when and how to offer a word of emotional support. Now computers are learning too, with the creation of a new algorithm that aims to deliver the right words at the right time.

"There's a lot of need for emotional support at the moment," says Judith Masthoff at the University of Aberdeen, UK, who is designing the system. "We have increased rates of mental health issues, and this has led to increased rates of informal care." Trained professionals are only available for the most extreme cases, so Masthoff suggests that people could get instant support from apps instead.

The task for Masthoff and her colleagues has been to turn a person's ability to offer a few words of support into a logical set of instructions - an algorithm, that could be put into practice by a computer.

They ran experiments to figure out what support to offer. Participants had to imagine different stressful situations and then choose the messages they would find most supportive, and their responses were built into an automatic system. A person recovering from injury or surgery, for example, would be presented with a message combining emotional reassurance and praise, something like: "I know this is hard but you are doing a great job". The system can also offer support to people pressed for time or experiencing high mental or emotional load.

This disruption to the wind pattern - called the "quasi-biennial oscillation" - did not have any immediate impact on weather or climate as we experience it on Earth's surface. But it does raise interesting questions for the NASA scientists who observed it: If a pattern holds for six decades and then suddenly changes, what caused that to happen? Will it happen again? What effects might it have?

"The quasi-biennial oscillation is the stratosphere's Old Faithful," said Paul Newman, Chief Scientist for Earth Sciences at NASA's Goddard Space Flight Center, Greenbelt, Maryland, and lead author on a new paper about the event published online in Geophysical Research Letters. "If Old Faithful stopped for a day, you'd begin to wonder about what was happening under the ground."

Winds in the tropical stratosphere, an atmospheric layer that extends from about 10 to 30 miles above Earth's surface, circulate the planet in alternating easterly and westerly directions over roughly a two-year period. Westerly winds develop at the top of the stratosphere, and gradually descend to the bottom, about 10 miles above the surface while at the same time being replaced by a layer of easterly winds above them. In turn, the easterlies descend and are replaced by westerlies.

Missing comet lander Philae has finally been found after two years lost in space. The good news is that the mystery of the lander's location has been solved - but the bad news is that it's trapped in a dark, rocky crevice on a comet.

The revelation by the European Space Agency has sparked excitement in the world of astronomy and beyond as many continued to root for the little robot to be located after it crash-landed in November 2014.

The ESA's Rosetta spacecraft captured images of the lander stuck in a dark crack on surface of comet 67P/Churyumov-Gerasimenko on Friday, less than a month before the mission is due to end.

A decade ago, Stephen Hawking warned that one of the major factors in the possible scarcity of intelligent life in our galaxy is the high probability of an asteroid or comet colliding with inhabited planets. This past December, a team of astronomers from Armagh Observatory and the University of Buckingham reported that the discovery of hundreds of giant comets in the outer planetary system over the last two decades means that these objects pose a much greater hazard to life than asteroids.

Giant comets, termed centaurs, move on unstable orbits crossing the paths of the massive outer planets Jupiter, Saturn, Uranus and Neptune. The planetary gravitational fields can occasionally deflect these objects in towards the Earth. Centaurs are typically 50 to 100 kilometer across, or larger, and a single such body contains more mass than the entire population of Earth-crossing asteroids found to date.

Because they are so distant from the Earth, Centaurs appear as pinpricks of light in even the largest telescopes. Saturn's 200-km moon Phoebe, depicted in this image, seems likely to be a Centaur that was captured by that planet's gravity at some time in the past. Until spacecraft are sent to visit other Centaurs, our best idea of what they look like comes from images like this one, obtained by the Cassini space probe orbiting Saturn. NASA's New Horizons spacecraft, having flown past Pluto six months ago, has been targeted to conduct an approach to a 45-km wide trans-Neptunian object at the end of 2018.

Calculations of the rate at which centaurs enter the inner solar system indicate that one will be deflected onto a path crossing the Earth's orbit about once every 40,000 to 100,000 years. Whilst in near-Earth space they are expected to disintegrate into dust and larger fragments, flooding the inner solar system with cometary debris and making impacts on our planet inevitable.

Known severe upsets of the terrestrial environment and interruptions in the progress of ancient civilisations, together with our growing knowledge of interplanetary matter in near-Earth space, indicate the arrival of a centaur around 30,000 years ago. This giant comet would have strewn the inner planetary system with debris ranging in size from dust all the way up to lumps several kilometres across.

Specific episodes of environmental upheaval around 10,800 BCE and 2,300 BCE, identified by geologists and palaeontologists, are also consistent with this new understanding of cometary populations. Some of the greatest mass extinctions in the distant past, for example the death of the dinosaurs 65 million years ago, may similarly be associated with this giant comet hypothesis.

Stanford engineers have developed a low-cost, plastic-based textile that, if woven into clothing, could cool your body far more efficiently than is possible with the natural or synthetic fabrics in clothes we wear today.

Describing their work in Science, the researchers suggest that this new family of fabrics could become the basis for garments that keep people cool in hot climates without air conditioning.

"If you can cool the person rather than the building where they work or live, that will save energy," said Yi Cui, an associate professor of materials science and engineering and of photon science at Stanford.

This new material works by allowing the body to discharge heat in two ways that would make the wearer feel nearly 4 degrees Fahrenheit cooler than if they wore cotton clothing.

If you think your "smart" appliances are the "cat's whiskers," then please think again! Actually, in my opinion, they are the dumbest things ever invented that have been able to buffalo consumers into spending their hard-earned money to purchase, but have the greatest potential for causing consumers harm and grief.

Recently, I received an email from one of my readers who had to attend a fire safety training session for 'their' job. That instructional course was given by none other than a Delaware County, Pennsylvania Fire Investigator, who was quite explicit in his presentation about certain fire causes.