SAN DIEGO — Since the moment he arrived in San Francisco, president of baseball operations Farhan Zaidi has preached about the importance of making smart and sound financial decisions to improve the Giants’ roster.On Tuesday at the Winter Meetings, Zaidi agreed to pay $12.67 million to acquire a player who may never take an at-bat for the Giants.It might be one of his best moves yet.Infielder Zack Cozart is the bigger name of the two players the Angels sent the Giants on Tuesday, but it’s …
tRNA: Guided Trackways: A paper in PNAS1 took five pages describing one tiny segment of the DNA translation process: the moment when transfer RNA (tRNA) enters the inner sanctum of the protein-building machine, the ribosome (see also summary on Science Now). If you have seen the animations in the film Unlocking the Mystery of Life, you probably remember the climactic scene of tRNAs lining up in assembly-line fashion as their attached amino acids are fastened together. Stunning as that animation was, it was vastly oversimplified. The ribosome actually contains a precisely-molded entrance tunnel where each tRNA is inspected and guided into place before allowed into the active site. Each tiny movement along the track is authenticated by contacts with specific atoms at checkpoints along the way. A Los Alamos team achieved the highest-resolution images yet of this process and found that parts of the tRNA and the tunnel turnstiles actually flex as much as 20° as part of the guided entrance, called accommodation. Their diagrams show multiple precision contacts all along the four specific stages of accommodation they investigated. Whether able to follow their dense jargon-laden description or not, the reader is sure to get the sense that something incredibly precise is going on. And then to learn that it all takes place in two nanoseconds is almost too much to handle. DNA Copying: Tight Fit: Another paper in PNAS2 explored the fit of DNA bases in the copying machinery at the sub-angstrom level (an angstrom is 10-10 meter, about the width of a hydrogen atom). Stanford and MIT scientists investigated how thymine fits into DNA Polymerase I as the genetic code is transcribed. As in the tRNA case above, the fit is precise and guided. They were surprised to find a little bit of margin inside the active site, which they speculated might “allow for an evolutionarily advantageous mutation rate.” Nevertheless, their “results provide direct evidence for the importance of a tight steric fit on DNA replication fidelity.” The tight fit ensures that illegal interlopers cannot make it into the active site. They also found that simple Watson-Crick base-pairing was not sufficient: the machines actually force the bases together in a coordinated way with error-checking. They remarked that this authentication and guidance system is speedy: “This choice, which occurs dozens of times per second, involves the selection of one nucleotide among four for insertion into the growing primer strand, opposite each DNA template base as it is addressed in turn.” (Emphasis added.) Unzipping Acrobatics: A paper in Nature3 investigated helicases, the molecular machines that unwind and unzip DNA strands. “Helicase enzymes can move along DNA or RNA, unraveling the helices as they go,” said Eckhard Jankowsky in an analysis of this paper in the same issue.4 “But simply traveling along a nucleic acid in one direction seems not to be enough for some of these molecular motors.” They discussed how helicase repeatedly bends over, forms loops, and snaps back into position during the operation. These acrobatic machines don’t just plod along in one direction but undergo a complex choreography with moving parts as they consume ATP for energy. The “repetitive shuttling” the authors described has a purpose, possibly for “keeping the DNA clear of toxic recombination intermediates.” Cellular Oarsmen: Three German researchers imaged eukaryotic flagella with twice the resolution of previous attempts. The whiplike propellers, which beat with back-and-forth motion (unlike the rotary flagellar motors of bacteria), contain a 9+2 arrangement of microtubules that are tied together with motors and spokes. “Both the material associated with the central pair of microtubules and the radial spokes display a plane of symmetry that helps to explain the planar beat pattern of these flagella,” they wrote. Their paper in PNAS6 includes a stereo pair image that provides a 3D look down the flagellum shaft. The literature is filled with examples like these. They usually say little or nothing about how these machines evolved; in fact, more often, they are likely to mention that the machines are “highly conserved” (i.e., unevolved) between the simplest one-celled organisms and humans. Though the articles valiantly attempt to describe what happens at these submicroscopic levels, the subject matter would greatly benefit from top-notch animation. Microscopic imaging technology keeps improving, though; some day soon, it may be possible for scientists to watch the machinery of the cell at its own nanometer scale in real time. Amazing discoveries about the cell are being made each week. It’s a shame more people don’t hear about them. They are usually written up in obscure journals with incomprehensible jargon, but when explained in plain English, the findings are truly astounding. Not long ago, the cell was a “black box,” a mechanism of unknown inner workings that somehow survived and reproduced. Only recently have imaging techniques allowed us to peer inside the box at the nanometer scale (one nanometer is a billionth of a meter) and see what is going on. Prepare to be astonished. A fundamental shift in thinking about cellular processes has occurred since the structure of DNA was elucidated in the 1950s, and has been accelerating ever since. What used to be mere chemistry is now mechanics; what used to be imagined as fluids mixing in a watery balloon is now programmed robotic machinery. Cells don’t just perform chemical reactions like we did in high school, pouring mixtures together and seeing if they explode or not. It’s more like robotics, and is properly known these days as “biophysics.” Cells are not just tossing ingredients together, but guiding them into place with motors, pivots, guardrails and inspectors.5 The cell is engaged in precision manufacture with molecular machines and motorized transport. The coolness factor of these molecule-sized gadgets would blow away any competition in Popular Mechanics if they could be appropriately visualized and described. Let’s try with some recent examples. 1Sanbonmatsu et al., “Simulating movement of tRNA into the ribosome during decoding,” Proceedings of the National Academy of Sciences USA, 10.1073/pnas.0503456102, published online before print October 25, 2005. 2Kim et al., “Probing the active site tightness of DNA polymerase in subangstrom increments,” Proceedings of the National Academy of Sciences USA, 10.1073/pnas.0505113102, published online before print October 25, 2005. 3Myong et al., “Repetitive shuttling of a motor protein on DNA,” Nature 437, 1321-1325 (27 October 2005) | doi: 10.1038/nature04049. 4Eckhard Jankowsky, “Biophysics: Helicase snaps back,” Nature 437, 1245 (27 October 2005) | doi: 10.1038/4371245a. 5This is not to say that biomolecular machinery looks like human machinery. Straight lines and geometric shapes are rare; tRNA entering a ribosome looks like spaghetti in a blender to an untrained eye. In addition, at the nanometer scale, molecules are subject to the random vibrations of Brownian motion. It has taken decades of careful research to tease out the order and intricacy of the cell’s moving parts. Nevertheless, the language of motors and machines in the literature is apt and ubiquitous, as is the language of physics (piconewtons of force, thermodynamics, translational motion in nm/s and rotational motion in Hz or rps). Human engineers are trying to emulate some of these machines in the new science of nanotechnology. 6Nicastro et al., “3D structure of eukaryotic flagella in a quiescent state revealed by cryo-electron tomography,” Proceedings of the National Academy of Sciences USA, 10.1073/pnas.0508274102, published online before print October 24, 2005. These are just a few of the reasons students should be allowed to hear about intelligent design. Darwin? He was just an old Victorian who didn’t know anything about this. If he had, he might have decided to stick with his training to become a country parson after all. This is the 21st century, folks: the age of nanomachinery and biophysics. Enjoy!(Visited 6 times, 1 visits today)FacebookTwitterPinterestSave分享0
Share Facebook Twitter Google + LinkedIn Pinterest The new John Deere 4640 Universal Display raises the bar for performance, uptime and cost of operation as part of the latest John Deere Generation 4 Operating System. For customers, this translates into better data collection, increased application functionality, and greater choice for monitoring and managing many tractor-driven field operations.The new 4640 Universal Display enables customers to use the most common and popular John Deere applications, including AutoTrac, documentation, and Section Control, in a portable display that has the latest internal components, design and user interface.“The new 4640 Universal Display provides a transportable, easy-to-operate solution for customers with the John Deere Generation 4 operating system,” said John Mishler, production and precision ag marketing manager for John Deere. “Some enhancements built into the display include more on-screen help and diagnostic information to keep operators running and informed of their display capabilities; simplified Work Setup app with page-by-page navigation; and greater user customization of run pages.”When it comes to performance, the 4640 Universal Display provides improved documentation for high-speed planting and nutrient applications, coupled with the latest data syncing functionalities for increased on-board/off-board flexibility. Additional enhancements include the ability to more accurately map and operate Section Control to precisely apply multiple products simultaneously with individual coverage maps and application points.The display is designed to import new customer and product information without the risk of overwriting existing client/farm/field and guidance line information. It also has an expanded suite of Precision Ag Core applications, including AutoTrac, Section Control and documentation, as well as wireless data transfer (WDT) with the “data sync” feature for automatic transmission of work documentation to the John Deere Operations Center.The time it takes operators to set up and start up the display has been reduced and display navigation has been improved. This equates to more uptime for the user, as a quickly learnable display results in reduced training time, more time working, and fewer operator mistakes.Cost of operation also is lower with the 4640 Display. Improved Gen 4 applications such as AutoTrac, Section Control, and documentation increase customer profitability by helping users work more efficiently, reduce overlap and skips, and maximize inputs and field operations. Combined with Gen 4 Section Control, operators can optimize field performance using distance and speed-based turning with the ability to dial in more quickly and accurately the desired settings.In addition, a power button has been added to the back of the 4640 Display so operators can shut the display off or reboot without powering down the tractor. The display is compatible with the Gen 4 Extended Monitor, which increases the number of run pages visible to the operator, giving easier access to more operation information.Mishler adds that precision ag software for the display is available as either one- or five-year subscription durations and in two levels, either AutoTrac only or as Precision Ag Core that includes not only AutoTrac but also documentation and Section Control. This gives customers the flexibility to match the right software subscription level and duration to their needs.“John Deere is the only supplier to offer machine-based precision ag subscriptions that allow customers to select the software they want and the duration of the subscription,” he said. “This gives customers a lower cost of entry into these precision ag applications and the ability to try new applications without having to buy permanent software licenses.”The 4640 Universal Display is available to order now. It is compatible with John Deere 30-Series to the latest 6R, 7R, 8R and 9R Series Tractors, as well as AutoTrac Universal and AutoTrac Controller compatible competitive tractors. Software update 17-2 is required for functionality. Precision ag application compatibility for implements and controllers, and for general applications, is limited to the latest Gen 4 OS software available.
AFP official booed out of forum 2 ‘newbie’ drug pushers fall in Lucena sting MOST READ Read Next Globe Business launches leading cloud-enabled and hardware-agnostic conferencing platform in PH “She’s a soldier,” he said. “She’s going to have some wine with me.” Slow and steady hope for near-extinct Bangladesh tortoises For McCollum, 50 points was enough.The Blazers guard’s final tally in the 124-108 victory over the Bulls on Wednesday night was a career high. So were his 18 field goals.FEATURED STORIESSPORTSWATCH: Drones light up sky in final leg of SEA Games torch runSPORTSLillard, Anthony lead Blazers over ThunderSPORTSMalditas save PH from shutoutMcCollum also became just the second NBA player in history to score 50 or more points in less than 30 minutes , joining Golden State’s Klay Thompson. Overall, he’s the sixth player to hit the milestone this season.He acknowledged afterward that reaching the 50-point plateau was special. And indeed when he left the Moda Center, he had the game ball tucked under his arm. Typhoon Kammuri accelerates, gains strength en route to PH McCollum’s feat came a day after James Harden had 60 in a triple-double that led the Rockets over the Orlando Magic, 114-107.It also helped the Blazers (29-22) to their fourth straight overall victory (the first four-game winning streak of the season) and eighth straight win at home. Portland rests in sixth place in the Western Conference and appears poised to make a second-half push for playoff position.It was clear McCollum was on his game from the start. He scored a franchise-record 28 points in the first quarter alone — besting Lillard’s previous record by a basket — including four 3-pointers. It was the most points scored in a quarter in the league this season.He punctuated the first half with a dunk, finishing the half with 32 points as the Blazers went into the break with a 67-44 lead.“Once he hit a couple of those tough ones, I was like, I mean I recognize that feeling and I saw the rhythm that he was playing with. At that point, it was just my job to make sure he got the ball in his hands as many times as possible,” Lillard said.After he sat down at the end of the third quarter, McCollum smiled when the crowd chanted his name.“I was thinking, I hope I don’t have to go back in,” McCollum said. “That means we’re not playing the way we should be playing. There was a lot of love tonight, and I appreciate it.”McCollum joined an elite group of 50-point Blazers: Lillard, Damon Stoudamire, Brandon Roy, Andre Miller, Clyde Drexler and Geoff Petrie.But what made it most special for McCollum was one face in the crowd. McCollum’s 92-year-old great aunt was visiting Portland for the first time and was at the game.He planned to celebrate with her afterward. Portland Trail Blazers guard CJ McCollum reacts after making a three-point basket against the Chicago Bulls during the first half of an NBA basketball game in Portland, Ore., Wednesday, Jan. 31, 2018. McCollum scored 28 points in the first quarter. (AP Photo/Craig Mitchelldyer)PORTLAND, Ore. — A smile crossed CJ McCollum’s face in the fourth quarter as he sat on the bench and the hometown crowd chanted “We Want CJ!”McCollum had already collected a milestone 50 points in the game against the Chicago Bulls. The crowd wanted more.ADVERTISEMENT Sports venues to be ready in time for SEA Games PLAY LIST 00:59Sports venues to be ready in time for SEA Games01:27Filipino athletes get grand send-off ahead of SEA Games00:50Trending Articles01:29Police teams find crossbows, bows in HK university01:35Panelo suggests discounted SEA Games tickets for students02:49Robredo: True leaders perform well despite having ‘uninspiring’ boss02:42PH underwater hockey team aims to make waves in SEA Games01:44Philippines marks anniversary of massacre with calls for justice01:19Fire erupts in Barangay Tatalon in Quezon City “A lot of the elite players score 50 points, that’s just the way it is,” McCollum said. “It shows you are a really unique scorer and have a lot of abilities.”McCollum sat in the fourth quarter for obvious reasons: The game was already a rout, and risking injury in a blowout was foolhardy. Sportsmanship comes into play, too.“At that point it was a 20-, 21-point lead? You don’t want no bad karma,” said teammate Damian Lillard, who holds the franchise record with a 59-point game last season. “I was thinking about that last year when I was in Miami, I had 49, and there was a couple seconds left and something happened where I could have gone over 50, and I was like, I’d rather take 49 the right way than go out there and force 50 and something bad happens.”But even so, some of his teammates wished the show could go on.“I wanted to see him score more,” Shabazz Napier said. “That’s just me being selfish, though.”ADVERTISEMENT Brace for potentially devastating typhoon approaching PH – NDRRMC LATEST STORIES Lakers rookie Ball to miss at least two more games John Lloyd Cruz a dashing guest at Vhong Navarro’s wedding NEXT BLOCK ASIA 2.0 introduces GURUS AWARDS to recognize and reward industry influencers Don’t miss out on the latest news and information. View comments
MOST READ Grace Poe files bill to protect govt teachers from malicious accusations With a classic Flash performance like that, it was impossible for Wade’s fellow NBA players not to take notice.Respect, @DwyaneWade pic.twitter.com/OjdAWnPepH— Golden State Warriors (@warriors) February 28, 2019 A legend with a legendary shot!!! 💥 #flash @DwyaneWade https://t.co/7lUgDIDo5e— Goran Dragić (@Goran_Dragic) February 28, 2019 Lacson backs proposal to elect president and vice president in tandem Private companies step in to help SEA Games hosting LATEST STORIES One of his closest friends, Chris Paul of the Houston Rockets, even poked fun at their upcoming matchup.Aight now @DwyaneWade…don’t come down to Houston with that nonsense tomorrow night!! 😂🤣😂 #OneLastDance— Chris Paul (@CP3) February 28, 2019In the post-game interview, Wade said he had fellow future Hall of Famer Kobe Bryant and his “mamba mentality” to thank for that insane clutch shot.“Thank you for showing me the way. Mamba Mentality!” said Wade.My man @DwyaneWade 💪🏾 #lastdance https://t.co/BEqk4qA1bV— Kobe Bryant (@kobebryant) February 28, 2019 It may have just been one of his last attempts to carry the Heat, who are struggling to make a decent playoff run in the East, on his shoulders–something which he had done countless of times in all his career in a Miami jersey.After heaving a one-legged three that banked off the glass and into the hoop as the time expired, Wade ran to the stands and thumped his chest in front of the overjoyed Heat fans at American Airlines Arena, his home for the last 16 years. ‘We are too hospitable,’ says Sotto amid SEA Games woes US judge bars Trump’s health insurance rule for immigrants This Is What He Does!!! Congrats @DwyaneWade for doing it once again 🙌🏻 #Legend pic.twitter.com/RL7YwF19f7— Mike Miller (@MikeMiller_13) February 28, 2019 On the same night, his bestfriend LeBron James also hit a tough clutch triple to help the Lakers beat the New Orleans Pelicans at home.READ: LeBron James’ 33, clutch 3 lift Lakers past Anthony Davis’ PelicansJames naturally took the opportunity to troll Wade, whom he won two championships with at Miami.“Mine was a little bit more difficult than his,” James said with a smile.Sports Related Videospowered by AdSparcRead Next Oil plant explodes in Pampanga town Sporting classic cornrows in tribute to Allen Iverson, Wade brought everyone back to his prime, delivering an unforgettable desperation three at the buzzer to carry the Heat to a 126-125 win over the defending champions Golden State Warriors.READ: He called game: Dwyane Wade banks in straightaway 3 to lift Heat past WarriorsDWYANE WADE buries the #TissotBuzzerBeater for the @MiamiHEAT victory! #ThisIsYourTime #OneLastDance pic.twitter.com/wxAFaxNn6X— NBA (@NBA) February 28, 2019ADVERTISEMENT SEA Games hosting troubles anger Duterte Trending Articles PLAY LIST 00:50Trending Articles02:25Raptors or Warriors? PBA players take their pick of NBA champ01:43Who are Filipinos rooting for in the NBA Finals?02:42PH underwater hockey team aims to make waves in SEA Games01:44Philippines marks anniversary of massacre with calls for justice01:19Fire erupts in Barangay Tatalon in Quezon City01:07Trump talks impeachment while meeting NCAA athletes02:49World-class track facilities installed at NCC for SEA Games02:11Trump awards medals to Jon Voight, Alison Krauss ADVERTISEMENT It must’ve been the hair or the fact that he is counting down to his last games in the league, but Dwyane Wade just showed why he’s one of the best to ever play in the NBA. Please don’t retire @DwyaneWade— Isaiah Thomas (@isaiahthomas) February 28, 2019 P2.5 B shabu seized in Makati sting, Chinese national nabbed Don’t miss out on the latest news and information. PBA D-League: Batangas-EAC manhandles McDavid View comments