Archaea Have Their Own Proofreading Mechanism

first_imgA team of Yale biochemists investigated a proofreading mechanism in one-celled organisms from the domain Archaea and found it different, but just as effective, as its counterpart in domains Bacteria and Eukarya (the latter including all plants and humans).  Their work was published online in PNAS July 6.1    The particular instance involved the ability to discriminate between two similar amino acids, threonine and serine, on the molecule that connects the amino acid to the transfer RNA (aminoacyl-tRNA synthetase, or aaRS).  Members of Archaea have an enzyme that bears no sequence similarity, but is “functionally conserved” (i.e., does the same thing), to that of the other domains.  The archaeal gene is “unrelated to, and absent from,” bacterial and eukaryotic genomes.  The authors term this an instance of “functional convergence of unrelated domains” that “assures specificity” of the correct amino acid to the tRNA molecule.  This “appears to be the first aaRS found to use two evolutionarily unrelated editing domains,” they state.  “The functional convergence between the two ThrRS editing domains is highlighted by the observation that both depend on an absolutely conserved set of histidine residues for their function.”1Korencic et al., “A freestanding proofreading domain is required for protein synthesis quality control in Archaea,” Proceedings of the National Academy of Sciences USA, 10.1073/pnas.0403926101.For a cell to be able to proofread at all is a profound morsel of food for thought.  How proofreading could emerge by chance is challenge for Darwinian evolution to explain, but for it to have arisen twice by different means is vastly more improbable (see online book).(Visited 5 times, 1 visits today)FacebookTwitterPinterestSave分享0last_img read more

Chromebook Pixel: Why It Hurts To Slam Beautiful, Unnecessary Hardware

first_imgRelated Posts The Rise and Rise of Mobile Payment Technology Why IoT Apps are Eating Device Interfaces Role of Mobile App Analytics In-App Engagement What it Takes to Build a Highly Secure FinTech …center_img markhachman Tags:#Apple#Chromebook#design#Google#Macbook Pro#Retina display “How many people does it take to change a light bulb?” goes a version of the old joke, best told in a thick German accent, like Klaus Myers. “None, if properly engineered,” is the punchline. That joke speaks to us geeks who look beyond the “it just works” mentality, into something that approaches a harmony of function and purpose. And it’s why I simply hate criticizing products that aspire to a higher form, just because something simpler, cheaper and more straightforward will do just as well.Like the Chromebook Pixel.Quite honestly, I feel guilty about panning the Pixel. As Dan Lyons notes, Google designers have quietly taken their efforts to another level. But, as virtually everyone who attended Google’s Pixel press conference noted, the Pixel simply prices itself out of the game. For now, very little within Google’s cloud – whether it be its 100,000 Stars app or the upcoming Photos enhancement – justifies the 2,560 x 1,700 multi-touch display, not to mention the $1,300 price tag. Google’s Chromebook has established a niche as a wonderful companion PC or netbook: as long as you want to work on the Web, a $250 Chromebook fills the bill. So what the heck does anyone need Pixel for?Still, there’s so much in the Pixel that feels like an homage to notebooks I’ve loved before. On the outside, the Pixel is the aristocratic, well-bred child of a MacBook Air and the Lenovo ThinkPad: a solid, lightweight, rectangular slab of aluminum. A thin light bar on top glows blue when powered on, then cheekily flashes the Google rainbow as the lid closes. Google eliminated the icons on top of the I/O ports, correctly reasoning that most users would identify them by sight. No, there’s no magnetic connector holding the power cord in, but a large LED glows yellow, then green, when the Pixel is fully charged. Vents push air to the side, somehow, presumably through the ports. The “piano hinge” attaching the display to the frame slowly glides shut. There’s even a third microphone buried beneath the keyboard to eliminate typing noises during Hangouts.And, of course, there’s that jaw-dropping display. Don’t be afraid about the Web moving to a touch model; I tried out Internet Explorer’s showcase touch-enabled Web app, Contre Jour, and it runs just fine.Google Is Not AloneThe Chromebook Pixel doesn’t stand alone as an example of marvelously over-engineered hardware. Say what you want about Google’s Nexus Q – as the odd hybrid of an audio amplifier and media player, the fact that it only played back YouTube and Google Play videos eventually doomed it. But from a hardware standpoint, the odd little sphere with the LED strip around its equator and an amplifier inside was a revolution, just one that failed.I feel the same about the Lytro post-focusing camera, which many heralded as the evolution of consumer photography: terrific technology, but one that the world never needed. It didn’t help that the first iteration of the product looked like a spyglass, contained a woefully inadequate LCD viewfinder, and required the photos to be stored on the company website for best effect. Lytro has its fans, but the company’s status as the next “it” thing has long vanished.Everyone has their favorite examples of well-designed, yet ultimately irrelevant technology; the $1,699 Hitachi IdeaCentre Horizon Table PC, for example, which doubles as a high-definition Monopoly table. The Microsoft Surface, possibly, a marvelous piece of hardware that still prices itself out of some tablet conversations. Some lumped Apple’s “retina display” MacBook Pros into this category when if first came out, although over time the MacBook has developed a wealth of graphics apps supporting it that could help justify the high-resolution display.(See also Apple’s Brilliant Boondoggle: MacBook Pro Retina Display.)When Technology Trumps ProductI don’t review products for a living, but anyone who does do must constantly wrestle with a dilemma: How do you inform readers that a particular product may not be ready for prime time, but whose underlying technology is so innovative that it deserves commendation and even preservation? Two years ago, I wrote this piece about the Lytro, partly as a reaction to a generation of young bloggers who too-often seemed to naively accept the promise of any new technology.These days, the tech press seems to revel in asking the tough questions. If anything, the press pendulum has swung back toward cynicism.At the same time, though, crowdsourcing sites like KickStarter have become unabashed celebrations of entrepreneurship, bypassing the press to connect products directly with fans and backers.That’s a big difference: By exposing their plans and pricing, young start ups can work hand-in-hand with prospective customers. The risk of secrecy, as larger corporations sometimes discover, is that you can lose touch with the very customers you’re trying to court. And end up with a powerful, beautiful but over-priced, over-engineered product that isn’t well suited to meeting the needs of actual customers. It just hurts, sometimes, to have to be the one to break it to the folks who worked so hard to create something really cool that doesn’t have a clear place in the world.last_img read more

Revealed: Aamir Khan’s look in Dhoom: 3

first_imgHaving sported a moustache in Mangal Pandey and a beefed-up look in Ghajini, actor Aamir Khan is again experimenting with his looks in Dhoom: 3 where he is likely to appear lean.Aamir Khan, who is all charged up for Aditya Chopra’s Dhoom: 3 in which he will be seen as a baddie, appeared at a media conference today in a lean avatar, sporting a stud.On being asked if this is the look for Dhoom: 3, Aamir said, “I have started shooting for Dhoom: 3. Almost…this is what it will be like (look) except the clothes that I am wearing now. I will have to do a lot more.”Dhoom series revolves around daring theft plans, handsome thieves and bike chases.After the success of Dhoom (2004) and Dhoom: 2 (2006) there is already a buzz about the third instalment of the film.Abhishek Bachchan and Uday Chopra will continue to reprise their roles as Jai and Ali, respectively, while Aamir Khan will be seen in a negative role, opposite Katrina Kaif.Directed by Victor Acharya, Dhoom: 3 is slated to release next year.last_img read more

South Africas Naspers cashes in 10bn Tencent stake

South African internet and entertainment group Naspers raised $9.8 billion selling two percent of its hugely-profitable stake in Chinese technology giant Tencent © 2018 AFP Naspers’ investment in Tencent has been “one of the greatest venture-capital investments ever”, according to Bloomberg News.It said the stake in Tencent that Naspers bought for $32 million in 2001 was valued at $175 billion on Thursday.Naspers, Tencent’s biggest investor, vowed to not sell any more shares for three years.”These funds will be utilised to reinforce Naspers’ balance sheet and invested over time in Naspers’ development businesses,” the Cape Town-based company said in a statement.Shenzhen-based Tencent has risen rapidly as China embraced the internet, with the company’s fortunes boosted by its WeChat social media platform.WeChat crossed the one-billion users mark after the Chinese New Year in February. South African internet and entertainment group Naspers on Friday raised $9.8 billion (7.8 billion euros) selling two percent of its hugely-profitable stake in Chinese technology giant Tencent. Explore further This document is subject to copyright. Apart from any fair dealing for the purpose of private study or research, no part may be reproduced without the written permission. The content is provided for information purposes only. Citation: South Africa’s Naspers cashes in $10bn Tencent stake (2018, March 23) retrieved 18 July 2019 from https://phys.org/news/2018-03-south-africa-naspers-cashes-10bn.html China’s Tencent to take stake in Ubisoft games maker read more