December 19

Darwin Demo Falls Short

first_img(Visited 55 times, 1 visits today)FacebookTwitterPinterestSave分享0 What the new “evolution in action” experiment lacks in Darwin support is compensated by its propaganda value.A cursory look at a story in The Atlantic would lead readers to suspect that the creation-evolution debate is over, and Darwin won. You can even watch the victory lap in the embedded video clip. Bacteria at both ends of a rectangular grid, made out like a football field, race to the midline, overcoming antibiotics first 10, then 100, then 1000 times the strength needed to kill them. It’s survival of the fittest! Send this demo to the classrooms of America:Beyond any applications in research and medicine, the MEGA-plate also makes for a wonderful teaching tool. It makes the abstract concrete. It vividly brings the process of evolution to life—and to view. “We’re visual creatures,” says Baym. “Seeing is believing.”When Michael Baym and Tami Lieberman of Harvard shared the video at an evolutionary conference last month, their colleagues were instantly cured of lockjaw:…many attendees were awed and slack-jawed. “It’s exciting, creative and, game-changing,” says Shelly Copley from the University of Colorado, one of the organisers. Baym himself, who has seen the movies hundreds of times, is still blown away by them. “You can actually see mutations happening,” he says, before shaking his head and smiling.The results were published in Science Magazine under the title, “Spatiotemporal microbial evolution on antibiotic landscapes.” Does a closer look at the methods and results vindicate Darwin? The “evolution” of antibiotic resistance is nothing new. ID advocate Michael Behe discussed it at length in his second book, The Edge of Evolution. He showed that in ideal test conditions—the evolution of malarial parasite resistance to chloroquine and other chemicals—Darwinian evolution was incapable of crossing fitness landscapes requiring more than two coordinated mutations. Malaria parasites could sometimes survive antimalarial drugs, but only by “throwing stuff overboard” – i.e., engaging in desperate attempts to survive through loss of information. (By analogy, a criminal can evolve resistance to handcuffs by having his hands cut off.)To succeed in demonstrating Darwinian evolution, Baym would need to show (1) realistic starting conditions, (2) the unguided emergence of new genetic information, (3) positive selection, (4) fitness increase over wild type, (5) speciation, (6) some innovative heritable structure capable of leading to new branches of organisms, and (7) successful competition of the winners in the real world, alongside other organisms in the ecology. Let’s examine the paper for these requirements.Realistic starting conditions? The Materials & Methods section shows that they used a “strain from the Keio collection of E. coli K-12 BW25113 knockout variants.” The platform on which the experiment was run was highly artificial, consisting of purified agar, with several rounds of artificially-selected bacteria as starters. The environment contained no other organisms that wild E. coli were likely to encounter in the wild.New genetic information?  The authors discuss mutations, but there is no mention of beneficial mutations or gain-of-function mutations. Michael Behe claims at Evolution News & Views that over half the identified mutations amount to loss of function. The others are likely deleterious as well:The key to understanding the paper is its Figure 3C. There it shows the genes that have undergone more than one mutation across tested bacteria. They break the mutations down into silent changes, changes of amino acids (point mutations), and insertion-deletion or nonsense mutations, which almost certainly are loss of function (LOF). Over half of genes contain such LOF mutations, along with some point mutations, which likely also degrade or destroy function. In other words, devolution.Positive selection?  There is no mention of positive selection in the paper among the 11 mentions of the word. Nor is there mention in The Atlantic.Fitness increase?  There is no mention of fitness increase in the paper among the 5 words “fit” or “fitness” and no mention of the word in The Atlantic.Speciation?  The organisms at the beginning and end of the experiment are still not only E. coli, but descendants of the original strain of E. coli.Innovation?  The word “innovation” is lacking in the paper. The word “novel” is only mentioned as a possibility for future experiments: “Owing to the relaxed evolutionary constraints in range expansion dynamics, the MEGA-plate is likely to reveal novel mutational pathways to high-level multiantibiotic resistance.” In a companion piece in Science, Luke McNally and Sam P. Brown claim innovation, but provide no specifics: “The advent of evolutionary innovations via mutation and the subsequent selection of these mutants are thus imprinted on the plate, providing an unprecedented visualization of evolution through time and space.” The innovation, however, is merely inferred from the fan-shaped patterns on the advancing fronts of resistant strains.Competition in the wild?  No mention is made of releasing the winning germs back into the wild to see if they could survive and proliferate in real-world conditions against their less-evolved progenitors. McNally and Brown admit this: “the MEGA plate could be criticized as merely a caricature of real-world environments, but such a perspective misses its value as a tool to elucidate the fundamental principles of evolution in a spatial environment.” Surprisingly, they also consider Lenski’s Long-Term Evolution Experiment (LTEE) with E. coli to be vulnerable, too: it “could be similarly criticized for being unrealistic yet has provided key insights into the longterm bounds of evolutionary fitness and the dynamics of evolutionary innovations, among many other discoveries.” But if they are both unrealistic caricatures, how can they provide insight? Maybe it’s just in the propaganda arena.Propaganda ValueThe true significance of this paper is its visualization potential to promote evolution to unsuspecting students. Baym’s statement “seeing is believing” makes that clear, but the last sentence in the paper is even more explicit:Its relative simplicity and ability to visually demonstrate evolution makes the MEGA-plate a useful tool for science education and outreach.In short, a visual aid that demonstrates nothing of Darwinian evolution can nonetheless serve as a “useful” teaching tool to promote Darwinian theory. Useful to whom? “In other words, the MEGA-plate does not correspond to the real world and may be irrelevant to medicine,” Behe says. “Instead, its value will be primarily to indoctrinate students in evolution.”We want to see the germs evolve powered flight, sonar, and the ability to compose symphonies. Then we’ll be impressed.last_img read more

December 16

Beefing Up Insulation (and Making it Easier to Hang Cabinets) in a Kitchen Remodel

first_img Q&A: Is Dense-Packed Cellulose an Air Barrier?Are Dew-Point Calculations Really Necessary?When Sunshine Drives Moisture into WallsGreen Basics: Rigid Foam InsulationVapor Profiles Help Predict Whether a Wall Can DryRELATED MEDIA RELATED ARTICLES Perfect Wall, Roof & Slab (podcast)The History of Insulation (podcast)GREEN PRODUCT GUIDE “You’ll have to move the electrical boxes inward or use deep box extensions,” he adds. “For that, I’ve used plywood pieces attached to sides of studs to attach the boxes.”David Meiland wouldn’t bother with continuous layer of plywood, either. “But,” he adds, “I might run a 2×4 across the wall at the top of the uppers, interrupting the foam. Tape the 2×4 to the foam.”Andy Ault, however, favors the plywood route. In fact, it’s standard operating procedure for his crew when they build wine cellars.“The only difference being that we step up to 3/4-in. ply to increase our holding power,” Ault writes. “Granted, those racking systems have many more points of attachment, but it’s still super helpful to know that no matter where the layout lands and no matter where we may need to shim that we will have a solid material to bite into.”The problem with blocking, he adds, is that it introduces more voids in the insulation and adds to thermal bridging. In addition, trying to sink 3-in. screws through a layer of insulation and catch blocking perfectly may be harder than it sounds.What about moisture issues in the walls?The existing wall may not be at the top of the class from an insulation standpoint, but it’s also unlikely to trap much moisture, either, as Meiland points out. But, he says, “Once you add the foam you reduce the amount of air and heat going out and it may not dry as well.”Moisture working its way in from the outside and collecting in the cellulose insulation is another concern, Ault says.“Given the possibility of reduced drying potential, I would probably go with something like Roxul vs. cellulose,” Ault says, referring to a type of rock wool insulation. “That way it’s just one less food source if moisture does end up in the cavity for longer periods.”He also suggests adding some asphalt felt to the back side of the exterior sheathing while the wall is opened up. In the event that some water is pushed through the wall, it would be a hedge against water penetration while still allowing the wall to be vapor-permeable.“And depending on what region you’re in and what direction the wall faces, this may also help to give you a little resistance to inward solar vapor drive,” he adds.What type of foam is best?Riversong likes the original plan, minus the plywood, and recommends that Nash use XPS (extruded polystyrene) rather than foil-faced polyisocyanurate, to allow for some vapor permeance.“I would not install any felt or other membrane inside of the sheathing, as that will do little to prevent water intrusion, which will still soak into sheathing and framing members, making them more vulnerable,” he says. “And I would not hesitate to use dense-pack cellulose, since it can tolerate cyclical wetting and redistributes moisture so well as to reduce the vulnerability of the framing in the event of leakage.”Nash wonders about the choice of XPS over the less permeable polyiso: “If a goal is to reduce the moist air moving into the wall in winter, why not go with the foil-faced? Is it to have some potential to dry to the inside when needed?”XPS and foil-faced foam board both have the potential to be perfect air barriers, Riversong replies. But 1 1/2-in. XPS has a permeance of 0.75 perm while the polyiso has a permeance rating of close to zero.“So XPS will allow some inward drying potential, while foil will trap moisture,” he says.An expert’s opinion:We asked GBA Technical Director Peter Yost for his take on the question. Here’s his reply:1. On securing the cabinets:While I like the 2xs as less material-intensive for securing the cabinets, I have to go with Andy Ault on this one. Eliminating the thermal bridging and being able to secure anywhere on the plywood wins out with me. When I built my SIP kitchen addition, I got some really superior screws from Winter Panel with a thread count and coarseness of thread that gave excellent holding power even in 1/2-inch OSB.2. Moisture management in 2x walls with interior rigid insulation:If you are reducing the drying potential of the framed wall, make sure that you have checked or even improved the bulk water protection of the wall. Overhangs, flashings, etc. should be checked to make sure that the wall is not already challenged by moisture.Because this kitchen remodel is in the Northeast, I agree with Robert Riversong in terms of the XPS and its 0.75 perms being a better bet than the 0 perm foil-faced polyiso rigid foam. We want to maintain whatever drying potential we can even as we seek to keep wintertime moisture out of the wall assembly.If the rigid insulation is taped and installed as an interior air barrier, it would be nice to choose a cavity insulation that restricts air flow in the framing cavity. While neither dense-packed cellulose nor Roxul batts are considered air barriers by a long shot, they are less air permeable than some other batt or blown products. Having just used Roxul batts in my attic, I really like how they perform.Finally, match high performance walls in the kitchen with a high performance exhaust system. Keep the kitchen drier, more efficiently, with an Energy Star exhaust fan vented to the exterior.center_img Premier Building Systems’ SIPsWinter Pane EPS and Polyurethane SIPsFoamglas, My New Favorite Insulation Eric Nash is renovating a kitchen with “old school” 2×4 walls. He’s gutting the room, but not touching the outside of the house. He’d like to present the homeowners with some options for increasing the R-value of the exterior walls while making a better air seal.Here’s his plan: fill the stud bays with cellulose, add 1 1/2 in. of rigid foam insulation on the inside, then a layer of 1/2-in. plywood on which to hang cabinets, and, finally, 1/2-in. drywall.How about that? he asks in a Q&A post at Green Building Advisor.Is plywood necessary to hang cabinets?Anyone who’s installed kitchen cabinets knows how reassuring it is to have solid material in the walls to catch mounting screws. That’s what the layer of plywood beneath the drywall would accomplish.But is 1/2-in. plywood enough?Robert Riversong doesn’t think so. “If it’s only the cabinets you’re concerned about, I would forgo the plywood, install appropriate blocking and use 3-in. cabinet screws,” he writes. “I would rather have cabinets secured to framing than to 1/2-in. plywood.last_img read more

December 1

J&K fuels statehood hopes in northeast

first_imgThe Centre’s move to scrap Article 370 and Article 35A and bifurcate Jammu and Kashmir into two Union Territories has fuelled statehood hopes in the northeast. Several civil society and extremist groups have been fighting for the creation of ethnicity-based States or UTs in four of the six States protected under variants of Article 371 of the Constitution. These States are Arunachal Pradesh (371H), Assam (371B, for specific tribal areas), Manipur (371C), Mizoram (371G), Nagaland (371A), and Sikkim (371F). Arunachal Pradesh, Mizoram and Nagaland are also protected under the Bengal Eastern Frontier Regulation of 1873 that requires non-residents or outsiders to possess an inner-line permit to visit. On Monday, Assam’s Rajya Sabha member Biswajit Daimary demanded upgrading the Bodoland Territorial Council to a Union Territory.The development in Kashmir has also spurred the Bharatiya Gorkha Parishad (BGP) to renew its demand for Gorkhaland comprising Darjeeling and parts of the Dooars area of northern West Bengal. “The BJP must now fulfil its promise, made in its election manifesto, of finding a permanent political solution for the Gorkhas in India,” the BGB said in a statement.The Eastern Nagaland People’s Organisation, has also renewed its demand for the creation of the Frontier Nagaland State. Three of these four districts – Kiphire, Mon, Tuensang and Longleng – border Myanmar and are strategic for India.last_img read more

November 27

Tiger Woods to open Match Play against PGA Tour rookie of year

first_imgTiger Woods tees off on the eighth hole during the final round of The Players Championship golf tournament Sunday, March 17, 2019, in Ponte Vedra Beach, Fla. (AP Photo/Lynne Sladky)AUSTIN, Texas — Tiger Woods is at another new golf course for a World Golf Championships event and faces another player he doesn’t know.Woods, who arrived Monday and played nine holes at Austin Country Club, opens the Dell Technologies Match Play against Aaron Wise, an NCAA champion from Oregon and the PGA Tour rookie of the year.ADVERTISEMENT Trump tells impeachment jokes at annual turkey pardon event The only drama late in the selection process was when Jordan Spieth in the “B″ group as the No. 28 seed had yet to be taken, and Patrick Reed from the “A″ group as the No. 16 seed was still available. Reed beat Spieth last year to advance out of group play, and they were split up as Ryder Cup partners in France, which led Reed to complain that Spieth was behind the split. Cayetano: Senate, Drilon to be blamed for SEA Games mess View comments MOST READ Wintry storm delivers US travel woes before Thanksgiving Cristiano Ronaldo not too worried after leg injury in Portugal draw The last time Woods played in this fickle event was in 2013 in the high desert of Arizona when the Match Play was single elimination. The only three-time winner, Woods was beaten in the first round by Charles Howell III.Now it features 16 four-man groups, round-robin play Wednesday through Friday, with the winner from each group advancing to the knockout stage over the weekend. LATEST STORIES Private companies step in to help SEA Games hosting Panelo: Duterte ‘angry’ with SEA Games hosting hassles Google Philippines names new country director Colombia protesters vow new strike after talks hit snag The 64-man field based on the world ranking from two weeks ago was divided by their seeds to determine who went into the top 16 groups — Nos. 17-32, Nos. 33-48 and Nos. 49-64 — and it was a lottery to see which player went into each group.There still was very little intrigue.Dustin Johnson, the No. 1 seed for the third straight year, has Hideki Matsuyama, Branden Grace and Chez Reavie. Johnson, who won the last World Golf Championship in Mexico City last month, opens with Reavie, who needs to advance out of group play to have any chance of cracking the top 50 in the world to get into the Masters.Rory McIlroy, who won The Players Championship two weeks ago and has yet to finish worse than a tie for sixth this year, has Matt Fitzpatrick, Justin Harding and Luke List, the last player to get into the field.One group has nothing but major champions. Jason Day, the No. 12 seed, drew Phil Mickelson, Henrik Stenson and Jim Furyk. Mickelson and Stenson meet on Wednesday, only the second time they have played together since Stenson won their duel at Royal Troon in the 2016 British Open.ADVERTISEMENT Sports Related Videospowered by AdSparcRead Next Wise will be the 21st player who had never played with Woods since he returned from back surgeries that kept him out of golf for most of two years.Woods, the No. 13 seed, also has Patrick Cantlay and Brandt Snedeker in his group. The only other time Woods played against Cantlay was in the 2011 Open when Cantlay was a sophomore at UCLA.FEATURED STORIESSPORTSPrivate companies step in to help SEA Games hostingSPORTSPalace wants Cayetano’s PHISGOC Foundation probed over corruption chargesSPORTSSingapore latest to raise issue on SEA Games food, logistics 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 Alas, Spieth’s number was called to play with Bubba Watson, the No. 15 seed and the defending champion of a tournament he really doesn’t like all that much.“I vote every year not to have Match Play because I feel like I have a better chance in 72 holes than do I individual, because we have seen every year a guy shoot in the 60s and lose and then we see a guy shoot in the 70s and win,” Watson said Sunday. “And it’s like, ‘Wait a second, how fair is this?’”Also in that group are Billy Horschel, whom Spieth will face Wednesday, and Kevin Na.Reed got Sergio Garcia, Shane Lowry and Andrew Putnam. Don’t miss out on the latest news and information. Bloomberg: US would benefit from more, not fewer, immigrantslast_img read more