Tag: 杭州百花坊官网

Clutch Enables Your Motors to Achieve 100% Efficiency

first_imgThose little ATP synthase motors (see 01/30/2005 entry) in your body and (in all living cells) made news again in Nature1 last week.  Scientists in Tokyo performed an ingenious set of experiments to measure the efficiency of the F1 synthesizing domain.  They attached a tiny magnet to the camshaft so that they could turn it with electromagnets at will, and they carefully measured the amount of ATP synthesized or hydrolyzed as the motor turned anticlockwise or clockwise under their control.  In the hydrolysis cycle, they found that the motor did not waste ATP; each molecule was successfully hydrolyzed with perfect efficiency, to the limits of their detection.    A particular focus of their investigation was the role of the eta subunit, which is attached to the gamma camshaft.  During hydrolysis, the “downhill” function, it did not seem to matter whether eta was present or absent.  But in the “uphill” process (synthesizing ATP), it made a dramatic difference.  Without eta, each rotation produced, on average, only one product, but with it, they got three per revolution, with at least 77% efficiency.  The actual efficiency was probably higher, but was hard to measure for such small entities.  In best cases, it was 100%, they said: “Therefore our data point to an excellent mechanochemical coupling efficiency.  In the best cases, we observed the postulated value of three ATPs synthesized per turn.”    “These results are consistent with the ubiquity of this strategic enzyme that fuels most of the energy consuming biological processes,” they said (emphasis added in all quotes).  “The present work reveals the unexpected importance of the eta-subunit in the synthesis of ATP.”  Though its precise function remains to be discovered, it was known to play a regulatory role; now, this team suspects it acts like a structural switch or clutch to lock the enzyme into synthesis mode.  Without it, the tiny motor undergoes wasteful slippage.As a reminder to recent readers, you can find a wonderful animation of this molecular machine on the website of German biochemist Wolfgang Junge.  It is labeled “F0F1-ATPSynthase (animation)”  See also his Model Schematic.1Rondelez et al., “Highly coupled ATP synthesis by F1-ATPase single molecules,” Nature 433, 773 – 777 (17 February 2005); doi:10.1038/nature03277.By now, you expect our next observation: “The authors made no reference to evolution in their paper.”  They are treating these devices as actual mechanical motors, with stator, rotor, camshaft, and purposeful function, achieving performance stats beyond the dreams of human engineering.  Eat your heart out, David Hume.(Visited 9 times, 1 visits today)FacebookTwitterPinterestSave分享0last_img read more

Ski Enceladus

first_imgWant the ultimate in powder snow?  Ski Enceladus, a little moon of Saturn.  The snow is deep and vast.  Drawbacks: except for occasional craters and steep canyons, the land is flat; there are no ski lifts; there is no air; you would weigh one or two pounds, and transportation will cost you billions of dollars.  Other than that, science news outlets are advertising it as a great place for snow lovers! “Enceladus weather: Snow flurries and perfect powder for skiing.”  That’s PhysOrg’s travel ad (a.k.a. science report) earlier this month. Cassini took two close passes by Enceladus this month, #14 on October 1 at 99 km, and #15 on October 19 at 765 miles.  In the second, the spacecraft was able to watch the light of two stars flicker on and off through the plumes.  The Cassini Imaging Team site Ciclops.org posted a preview of raw images from the latest flyby.  Another one, #16, comes up on November 6 at 496 km.  After a pause, there will be more close passes in March, April and May. That this little moon should have powder snow is astonishing.  The fine talcum-powder-size ice settles down by gravitational attraction from the particles spewing out of the moon’s south pole geysers. PhysOrg said the snow is not composed of snowflakes like we have on Earth, which require an atmosphere.  Instead, tiny ice particles fall on ballistic paths from the ejection sites (long, deep canyons called “tiger stripes” at the south pole).  Although it’s impossible to know the texture and depth of the deposits directly, scientists can infer the particle composition by comparing visible, ultraviolet and near-infrared measurements of the same regions.  According to Dr. Paul Schenk of the Lunar and Planetary Institute in Houston, the accumulated particles would be ideal for skiing. How long has this been going on?  The PhysOrg article stated, “Mapping of these deposits indicate that the plumes and their heat source are relatively long-lived features lasting millennia and probably tens of million years or more, and have blanketed areas of the surface in a thick layer of tiny ice particles.”  The error bars on that statement extend four orders of magnitude.  The problem with the higher figure (tens of millions of years) is keeping that amount of power going on this little moon for so long.  In fact, to believe that this moon is the assumed age of Saturn, little Enceladus would be coating itself with powder snow for 4.5 billion years.  Is there that much source water available?  If the geysering started more recently, what turned it on? Readers should remember that the geyser discovery was a surprise.  “The discovery by instruments aboard the Cassini orbiter that there’s a currently active plume of icy dust and vapour from Enceladus has revolutionized planetary science,” Schenk said.  It would seem that billion-year snow-coating of this moon would erase features.  We see some softening of crater edges, but numerous cracks and evidences of tectonic activity are visible.  From photos showing recent exposure of accumulated ice, scientists estimate some of the deposits are as much as a hundred meters thick at a maximum.  Using “models of plume deposition” that result in extremely slow accumulation, scientists did some calculations.  “To accumulate 100 meters of deposits would require a few tens of millions of years or so.” But that leads to a confusing conundrum: “This is important as it suggests that the thermal heat source required to drive the plumes and maintain any liquid water under the icy crust would also have to be similarly long-lived.” Long-lived, but long-lived enough?  Why are there not thousands of meters of deposits?  Can these plumes really have been active that long?  What is the energy source in such a small moon that should have frozen solid, like nearby Mimas, long ago?  So much material is coming out of Enceladus that it creates a giant ring around Saturn (the E-ring), composed of micron-size particles. Another moon of Saturn got some press this month: Titan, the largest.  Maps of this atmosphere-shrouded giant keep getting better and better (see Space.com).  Was Space.com able to resist the urge to say that Titan sheds light on the origin of life?  Yes! –but only on that first article about the maps.  In “The hazy history of air on Saturn’s moon Titan,” Shaun McCormack (a contributor to Astrobiology Magazine), used the L-word six times in another Space.com article.  (News flash: No life has been found on Titan, and it is almost 300 degrees below zero there.)  McCormack agreed the idea is somewhat incredible; “This is remarkable, because it was thought that Earth and Titan were made from a vastly different recipe of materials in drastically different temperatures,” he said.  But then he gave good press to some Spanish astrobiologists who envision Titan as a laboratory for the origin of life. Speaking of snow, the idea of a prehistoric “Snowball Earth” has been going in and out of fashion.  Astrobiology Magazine wove a tale about how life might have survived a global freeze, but the French, according to Science Daily, are challenging the very concept.  “Their work, published in the journal Nature, challenges part of the so-called ‘Snowball Earth’ hypothesis and rekindles the debate about the origins of the deglaciation mechanism.”  They could not find evidence for a steep climb in carbon dioxide levels.  That means Earth could never have gotten out of a deep freeze. Thankfully, we live on a planet with just enough ice and snow to give us fun things to do in the winter without making skiing mandatory 24 x 7 x 52. “Snowball Earth” is another one of those suggestive phrases that secular scientists come up with to titillate the imagination.  They don’t need evidence for it; in fact, it can contradict common sense – to get out of it requires ad hoc conditions.  But if it feeds the Grand Myth, it is useful.  The Grand Myth requires Earth to be born in fire, then go through trial by ice, then end up just right, as if testing all the options of Goldilocks’ soup.  Then, in some warm little pond, Evolution conjures up the elixir of life, just like it did with liquid methane on Titan.  Storytelling is fun because no evidence is required. Another observation of interest to psychologists of science (a new discipline emerging, according to Medical Xpress) is how the consensus-huggers deal with anomalies.  The Big Question that should emerge from observations of Enceladus is why these geysers are active today, if Enceladus is billions of years old.  A small sparkler does not burn for a year, and a small moon the diameter of Arizona does not have the heat to last 4.5 billion years.  How do the scientists respond?  They say it might have been going on for a few tens of millions of years.  Not even close.  Ten million is to a billion as one foot to a hundred feet.  Big problem.  Quick; let’s talk about life on Titan instead!(Visited 16 times, 1 visits today)FacebookTwitterPinterestSave分享0last_img read more

Why You Are Overconfident in Your Forecast and What To Do About It

first_imgIt is easy to believe that you are going to win the big deal you are pursuing. There is evidence available to you that supports this belief. For example, the contacts with whom you have met all agree that your solution is very good and that it is what they need. They’ve also been complementary, telling you that they’re impressed with what they’ve seen and heard so far. More still, they continue to ask you for more information.You know they have seen other potential partners, your competitors, but you are doubtful any of your competitors propose a threat when things are going so well. This deal looks like opportunities you’ve won in the past, and things are lining up nicely. You have no cause for concern, and your confidence is exceedingly high.Then, without warning, you discover you lost to a competitor.Evidence of the Non-ExistentThe lack of evidence of a competitive threat does not prove that there isn’t one. We tend to mistake something unknown for evidence of it not existing.It is important to know which contacts support change and who opposes any change. The fact that you don’t know who opposes the change you are recommending doesn’t mean they don’t exist. Nor does it mean they aren’t working to slow things down or stop them altogether.Equally important, you need to know who prefers you and who might support your competitor. The fact that you’ve built a coalition of stakeholders that believe that you and your solution are exactly right is not evidence that there is not another faction supporting your competitor. For every action, there tends to be an equal and opposite reaction, and this rule seems to be true inside groups.Support from someone with a title that suggests they are “the decision-maker” is helpful—and necessary—to winning a deal. It’s something you should seek if you want to win big deals. But the support of a key stakeholder is not evidence that the key “influencers” are going to get what they want and need, regardless of whether the “decision-maker” likes you the most. Influence is invisible, even though it often provides clues of its existence for those brave enough to look for them.A Hedge Against OverconfidenceThe reason we tend towards overconfidence in deals is because we see positive evidence without seeing evidence to the contrary. Because something is opaque doesn’t mean it is nonexistent, nor does it indicate that is a non-factor.Overconfidence, in many cases, is inversely proportional to win rates. As a hedge against your overconfidence, spend as much time looking for the ways you will lose a deal as you do talking about why you are going to win. Essential Reading! Get my first book: The Only Sale Guide You’ll Ever Need “The USA Today bestseller by the star sales speaker and author of The Sales Blog that reveals how all salespeople can attain huge sales success through strategies backed by extensive research and experience.” Buy Nowlast_img read more

Cavs suspend guard J.R Smith 1 game for detrimental conduct

first_imgMOST READ Smith attended Thursday’s morning shootaround, but the team did not announce his suspension until two hours before tip-off.“He was great this morning,” said Lue, who will start Rodney Hood in Smith’s place. “Something happened after shootaround, so, that’s all the details I’m going to give to you. He’ll be ready for tomorrow and be ready to go on Saturday (against Denver).”FEATURED STORIESSPORTSWATCH: Drones light up sky in final leg of SEA Games torch runSPORTSLillard, Anthony lead Blazers over ThunderSPORTSMalditas save PH from shutoutSmith has started 56 games, averaging 8.3 points, and is shooting 36 percent on 3-pointers.The 14-year veteran has struggled much of this season, but he had been playing better lately. Smith sat out the fourth quarter of Tuesday night’s win over Brooklyn. View comments Families in US enclave in north Mexico hold sad Thanksgiving FILE – In this Feb. 3, 2018, file photo, Cleveland Cavaliers’ J.R. Smith (5) drives past Houston Rockets’ Luc Mbah a Moute (12), from Cameroon, in the first half of an NBA basketball game in Cleveland. Smith has been suspended one game by the team for detrimental conduct. The team gave no further specifics about the punishment. Smith will serve the penalty on Thursday, March 1, 2018, night as the Cavs host the Philadelphia 76ers. (AP Photo/Tony Dejak, File)CLEVELAND — Cavaliers guard J.R. Smith has been suspended one game by the team for detrimental conduct.Coach Tyronn Lue gave no further specifics about the punishment. Smith will serve the penalty on Thursday night as the Cavs host the Philadelphia 76ers.ADVERTISEMENT Police teams find crossbows, bows in HK university PLAY LIST 01:29Police 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 Fight to the finish Brace for potentially devastating typhoon approaching PH – NDRRMC Typhoon Kammuri accelerates, gains strength en route to PH Google honors food scientist, banana ketchup inventor and war hero Maria Orosacenter_img Smith was acquired in 2014 in a trade with the New York Knicks and has been a key contributor during Cleveland’s run of three straight NBA Finals. LATEST STORIES Don’t miss out on the latest news and information. Pussycat Dolls set for reunion tour after 10-year hiatus LOOK: Iya Villania meets ‘Jumanji: The Next Level’ cast in Mexico John Lloyd Cruz a dashing guest at Vhong Navarro’s wedding AFP official booed out of forum Read Nextlast_img read more

Nikola Jokic continues to amaze as Nuggets rout Clippers

first_imgLATEST STORIES SEA Games: Biñan football stadium stands out in preparedness, completion Don’t miss out on the latest news and information. “He could play for NFL teams the way he passes the ball,” Malone said.Later, Jokic picked up his dribble on a play, saw the path through the lane was clear, banked it off the glass to himself and put it in. It was something he had never tried in a game before.And no, he wasn’t thinking slam.“I knew he wasn’t going to dunk it,” Murray cracked. “It was a smart move. It was a great play.”This capped off the night: Jokic and Miller exchanging jerseys.ADVERTISEMENT Nuggets: At Phoenix on Saturday before hosting Portland the following night.Sports Related Videospowered by AdSparcRead Next “It means a lot. I watched him a lot,” Jokic said. “He’s a beast. He’s someone that can’t be stopped.”These days, the same can be said of Jokic, who was coming off a game in Miami on Tuesday in which he had 29 points, 11 rebounds and 10 assists.“He’s just a great player,” Clippers coach Doc Rivers said.Murray scored 23 points and Mason Plumlee added a season-high 17 points to go with 12 rebounds for the Nuggets. They’re now 17-3 at home.Lou Williams led the Clippers with 19 points, and Danilo Gallinari chipped in 18 against his former team.Denver built the lead to 102-81 with 9:03 remaining on a jumper by Monte Morris. The Clippers made a little run, but Morris silenced it with a 3-pointer.“They just kicked our butt from the beginning,” said Tobias Harris, who finished with 18 points and 11 rebounds. “Their intensity and pace, we were kind of on our heels with all night. We’ve got to respect that especially from a team that’s No. 1 in the West.”Gallinari received applause from the crowd when he was announced. He joined the Clippers last season after a bulk of his career in Denver. He was limited to 21 games with Los Angeles in 2017-18 due to injuries and didn’t suit up when the Clippers played in the Mile High City.“It was a good feeling to see a lot of my friend and people that I know,” Gallinari said. “But honestly I was just focused on the game plan and trying to play my game and trying to help the team.”TIP-INS Behind LaMarcus Aldridge’s career-best 56, Spurs outlast Thunder in 2OT Hotel management clarifies SEAG footballers’ kikiam breakfast issue Private companies step in to help SEA Games hosting Another eventful evening for Jokic.The player nicknamed Joker finished with 18 points, 14 rebounds and 10 assists for his 21st career triple-double to help the Western Conference-leading Nuggets extend their home winning streak to 11 by cruising past the Los Angeles Clippers 121-100 on Thursday night.FEATURED STORIESSPORTSPrivate companies step in to help SEA Games hostingSPORTSUrgent reply from Philippine ‍football chiefSPORTSWin or don’t eat: the Philippines’ poverty-driven, world-beating pool stars“Another triple-double,” Nuggets coach Michael Malone said. “The guy continues to amaze.”Jokic did a little bit of everything, including the pass of the night when he lofted a full-length strike over a defender to Jamal Murray for a dunk in the third quarter. TS Kammuri to enter PAR possibly a day after SEA Games openingcenter_img LOOK: Joyce Pring goes public with engagement to Juancho Triviño Clippers: F Luc Mbah a Moute remains out with a sore left knee.Nuggets: G Gary Harris missed his second straight game with tightness in his left hamstring. … F Juancho Hernangomez has been dealing with an injury. Earlier this season, he dealt with an abdominal strain. “If it gets to a point we have to shut him down for a bit, we’ll do so,” Malone said.EJECTEDClippers guard Patrick Beverley was ejected in the fourth quarter for arguing.Asked what he may have said, Rivers responded: “I was in the huddle. I think he said I love you.”NATIONAL TREASURESJokic, who’s from Serbia, currently sits in seventh place among Western Conference frontcourt players in the All-Star voting by fans. Dallas rookie and Slovenian native Luka Doncic is second, with fans counting for 50 percent of the vote to determine the starters.“Obviously, a lot of fans in Slovenia are voting and not enough fans in Serbia are voting,” Malone cracked.UP NEXTClippers: Begin a four-game homestand Saturday against Detroit. SEA Games: Biñan football stadium stands out in preparedness, completion Is Luis Manzano planning to propose to Jessy Mendiola? MOST READ PH underwater hockey team aims to make waves in SEA Games PLAY LIST 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 SEA Games hosting troubles anger Duterte Denver Broncos linebacker Von Miller and Denver Nuggets center Nikola Jokic swap jerseys following the Nuggets’ NBA basketball game against the Los Angeles Clippers on Thursday, Jan. 10, 2019, in Denver. Denver beat Los Angeles 121-100. (AP Photo/Jack Dempsey)DENVER  — Nikola Jokic wowed his teammates with a perfect full-court pass that led to a dunk and by tossing a pass to himself off the backboard for a layup.The Denver Nuggets big man was the one wide-eyed after the game when he met Broncos pass rusher Von Miller and exchanged jerseys.ADVERTISEMENT View commentslast_img read more