The Pandoravirus (above) is physically similar, but shares very little in the way of genetic material with the newly discovered virus.
Up until recently, the line between viruses and cells seemed pretty simple: cells were big and carried everything they needed to live and grow. Viruses were tiny and only carried the genes they needed to take over their host cells; they relied on their hosts for most essential proteins.
That line got a bit blurry as we found parasitic and symbiotic cells with very stripped-down, minimalist genomes that wouldn't let them survive outside their hosts. But it's nearly been obliterated by the discovery of giant viruses—some of these have genomes that are larger than those of bacteria and carry many of the genes needed to copy DNA and translate it into proteins.
Scientists have now identified yet another giant virus, this time using a technique that sounds like it's straight out of a sci-fi horror flick: they thawed some 30,000-year-old permafrost and allowed any viruses present to infect some cells. Fortunately, the cells were amoebas, and this virus is overwhelmingly unlikely to present a threat to human health. But the fact that viruses could apparently survive so many centuries in the Siberian permafrost does lead the authors to suggest that the melting Arctic may pose an emerging disease risk.
Crows are smarter than great apes and about on par with a 5-year-old child. We know they (and similar birds) can already complete complicated tasks, like putting a stick through a tube to finagle out food. But in this BBC video, the crow, after thinking it over briefly, easily completes a multi-step puzzle.
I was not sure about the solution to this puzzle until very close to the end of the video. I choose to believe this says more about the crow than about me. Bravo, crow.
Your RNA here. The eterna interface makes it a snap to get your own custom RNA to form a specific structure.
Citizen science, the movement to draft non-specialists into areas of scientific research, doesn't require the volunteers to put on lab coats. In at least one case, scientists turned a prickly biochemical problem into a game and found that the gamers could typically beat the best computer algorithms out there.
But all that work was done on cases where we already knew the answers, which was how we were able to measure the gamers' success. Now some researchers have taken this approach one step further and created a hybrid project that mixes volunteers with lab-coated workers. 37,000 enthusiasts were given the chance to take on algorithms in designing new RNA molecules. And once the gamers had a chance to vote on the best designs, the winning designs were sent to a lab, synthesized, and tested. After a few rounds of this, players were not only handily beating the computers but providing rules that went into designing the next-generation algorithm.
A consortium of researchers at Carnegie Mellon, Stanford, and Seoul National University put together what they called a Massive Open Laboratory. Operated through a Web portal called "eterna," it provides a few tutorials that allow people to bring themselves up to speed on the base pairing rules that govern the structure of RNA molecules. These structures can fold up a linear RNA molecule into a catalytic form or allow it to bind other molecules and proteins. These structures are essential to basic cell functions, such as turning genes into mature messenger RNAs and then converting these messengers into proteins.
The development of human embryonic stem cells, which have the ability to form any cell in the body, may enable us to repair tissues damaged by injury or disease. Initially, these cells could only be obtained through methods that some deemed ethically unacceptable, but researchers eventually developed a combination of genes that could reprogram most cells into an embryonic-like state. That worked great for studies, but wasn't going to work for medical uses, since one of the genes involved has been associated with cancer.
Researchers have since been focusing on whittling down the requirements needed for getting a cell to behave like a stem cell. Now, researchers have figured out a radically simplified process: expose the cells to acidic conditions, then put them in conditions that stem cells grow well in. After a week, it's possible to direct these cells into a state that's even more flexible than embryonic stem cells.
The catalyst for this work is rather unusual. The researchers were motivated by something that works in plants: expose individual plant cells to acidic conditions, grow them in hormones that normally direct plant development, and you can get a whole plant back out. But we're talking about plants here, which evolved with multicellularity and with specialized tissues in a lineage that's completely separate from that of animals. So there's absolutely no reason to suspect that animal cells would react in a similar way to acid treatment—and a number of reasons to expect they wouldn't.
The completion of a Neanderthal genome showed that there was a very clear signal of Neanderthal DNA in all non-African populations of modern humans, demonstrating that the two populations had interbred during the latter's migration into Eurasia. But a statistical signal doesn't really tell you what's there. Do all humans carry the same few pieces of Neanderthal DNA, suggesting it has been contributing to our fitness? Or have bits of Neanderthal been scattered through the human genome, kept around by little more than random drift?
Two papers, one in Nature and the second in Science, attempt to answer these questions. Conveniently, they come up with the same answer. Yes, lots of Neanderthal DNA is scattered around at random—enough so that if it were all brought together in one individual, that person would be 20 percent Neanderthal. But there are also lots of bits that aren't located randomly. Some of them are useful, many others less so.
Given that we now have a few Neanderthal genomes, it might seem easy to spot pieces of DNA that originated there. But the Neanderthal genome is so similar to that of modern humans that it can be difficult to tell whether something originated the the Neanderthals or whether it's just a bit of normal variation. The task is made harder by the fact that recombination has scrambled the Neanderthal and human chromosomes so that the typical piece of Neanderthal DNA should now be less than a hundred thousand bases long; the chromosomes are millions of bases.
In recent years, astronomers have detected some simple organic chemicals in the disks of material surrounding some stars. In our own Solar System, these seem to have undergone reactions that converted them into more complex molecules—some of them crucial for life—that have been found on meteorites. So, understanding the reactions that can take place in space can help provide an indication of the sorts of chemistry available to start life both here and around other stars.
Based on a publication in Nature Chemistry, it seems that the chemistry that can take place in the cold clouds of gas of space is much more complex than we had predicted. Reactions that would be impossible under normal circumstances—simply because there's not enough energy to push them forward—can take place in cold gasses due to quantum mechanical effects. That's because one of the reactants (a hydrogen nucleus) can undergo quantum tunneling between two reactants.
The key to understanding the work is the idea of activation energy. Many reactions that are energetically favorable (think burning wood) simply don't happen spontaneously. That's because the intermediate steps of the reaction are higher energy states. You need some additional energy (like a lit match) to push things over the activation energy barrier and get things to run downhill to the product state.
The Internet is one of the most transformative technologies of our lifetimes. But for 2 out of every 3 people on earth, a fast, affordable Internet connection is still out of reach. And this is far from being a solved problem.
There are many terrestrial challenges to Internet connectivity—jungles, archipelagos, mountains. There are also major cost challenges. Right now, for example, in most of the countries in the southern hemisphere, the cost of an Internet connection is more than a month’s income.
Solving these problems isn’t simply a question of time: it requires looking at the problem of access from new angles. So today we’re unveiling our latest moonshot from Google[x]: balloon-powered Internet access.
We believe that it might actually be possible to build a ring of balloons, flying around the globe on the stratospheric winds, that provides Internet access to the earth below. It’s very early days, but we’ve built a system that uses balloons, carried by the wind at altitudes twice as high as commercial planes, to beam Internet access to the ground at speeds similar to today’s 3G networks or faster. As a result, we hope balloons could become an option for connecting rural, remote, and underserved areas, and for helping with communications after natural disasters. The idea may sound a bit crazy—and that’s part of the reason we’re calling it Project Loon—but there’s solid science behind it.
Balloons, with all their effortless elegance, present some challenges. Many projects have looked at high-altitude platforms to provide Internet access to fixed areas on the ground, but trying to stay in one place like this requires a system with major cost and complexity. So the idea we pursued was based on freeing the balloons and letting them sail freely on the winds. All we had to do was figure out how to control their path through the sky. We’ve now found a way to do that, using just wind and solar power: we can move the balloons up or down to catch the winds we want them to travel in. That solution then led us to a new problem: how to manage a fleet of balloons sailing around the world so that each balloon is in the area you want it right when you need it. We’re solving this with some complex algorithms and lots of computing power.
Now we need some help—this experiment is going to take way more than our team alone. This week we started a pilot program in the Canterbury area of New Zealand with 50 testers trying to connect to our balloons. This is the first time we’ve launched this many balloons (30 this week, in fact) and tried to connect to this many receivers on the ground, and we’re going to learn a lot that will help us improve our technology and balloon design.
Over time, we’d like to set up pilots in countries at the same latitude as New Zealand. We also want to find partners for the next phase of our project—we can’t wait to hear feedback and ideas from people who’ve been working for far longer than we have on this enormous problem of providing Internet access to rural and remote areas. We imagine someday you'll be able to use your cell phone with your existing service provider to connect to the balloons and get connectivity where there is none today.
This is still highly experimental technology and we have a long way to go—we’d love your support as we keep trying and keep flying! Follow our Google+ page to keep up with Project Loon’s progress.
Most of the life on Earth comes in the form of small, single-celled organisms. But even though we knew there was incredible diversity at the microbial level, these cells all look pretty similar under a microscope. For many of the bacterial species we've identified, the key step has been growing them in a flask so we can generate large enough numbers to study them.
Over the past decade, the advent of cheap DNA sequencing technology has helped the microbe discovery process along. Currently, we can sequence huge populations of microbes and get fragments of sequences that give us some sense of the full diversity of life. But these sequences tell us little more than the fact that a species exists. We still often know little about what it is and how it manages to make a living.
Now some researchers have managed to generate a genome sequence from a single bacterium, and they have used this technique to scan for new species in a biofilm isolated from a hospital sink. The results include the genome of a previously unrecognized phylum of bacteria, called TM6, that appears to be an obligate symbiote, perhaps living inside another cell found in the biofilm.
Like everything else, dating has moved online in recent years through a combination of organized dating services and incidental meetings (the Ars forums have enabled a number of matches). Now, a new survey of American households shows just how important this phenomenon has become: since 2005, a third of marriages were the result of online meetings, with nearly half of those coming through online dating services. The good news? Fewer relationships that started online ended up in divorce, and people were generally more satisfied with the ones that survived.
The numbers come from a survey sponsored by eHarmony, a dating site that frequently uses its advertisements to suggest that it makes matches based on psychologically validated personality profiles. As revealed in the conflict of interest statement, one of the researchers involved in the new study is a scientific advisor to eHarmony. But the researchers got the dating company to allow them to publish their survey analysis no matter what it showed, and the group hired an outside statistician to validate the work.
Overall, the survey included more than 19,000 people who had married between 2005 and 2012. Although it was performed online, the demographics of those who responded suggest it is broadly representative of the US population.