Friday, June 21, 2013
On Friendship
[ed. I like the term "carbonation" in reference to a certain type of friend. I share that inclination.]
“He has lots of friends,” we’ll mention in recommending somebody, whether a plumber or a stockbroker: he’s okay, he’ll lend an ear, he won’t leave a customer in the lurch. Lending an ear is essential in mainline friendships, and less disruptive than lending money. “I’m always here for you” is the desired pledge (like the colloquial promise “I have your back”) of best-friendship, a category often lasting at least until marriage, if not beyond. The personalities that occupy the niche—nerd or happy-go-lucky—might change according to the phases of life, but draw a nostalgic smile in our mind’s eye when we remember them. (...)
“How are you?” is the current universal greeting in America, yet not to answer “Fine” would violate the social compact in a minor way because almost nobody who asks wants to know if you’re not. If you can’t keep your marbles together, agencies exist to do it for you. Friends are for when the question isn’t rote, however, and the “Me, myself, and I” of childhood fame feels buffaloed. You and the cat are watching a hummingbird feeder out the window; yet you need more to get up and fight the day. Call a fellow vinyl collector, card player, Little League coach. Yes, the specialist told us on the spectrum of autism it’s a milder kind. … So he sez it was only a one-night stand; he didn’t expect me to cry. … My skills are dated or outdated, whichever term they used. … I was so happy for a second, I couldn’t speak, didn’t try, but then he died. … I wonder if 40 is too late to apply for the ministry? Is it silly to inquire? … The school apologized for letting him go home on the bus. They didn’t realize it was a concussion. … A friend pauses to listen, his grin of solace not a tic. (...)
In adulthood, friendships originate adventitiously: at the water cooler or neighborhood association. My closest in old age began when a pizza counterman made fun of my stutter and I returned out of curiosity to see why he would. It turned out that he needed affection so badly, he felt compelled to outrage strangers to test their loyalty; after testing mine, he became wonderfully generous, recounting dozens of typewriter-ready stories I could make use of, from war lore to which of the ladies in the Laundromat had turned tricks (he said) in her youth.
He protected my house from robbery or vandalism during hunting season, while mending relations with his children, estranged to various degrees, rehearsing with me his explanations to them beforehand. His fireman father had thrown his mother down the cellar stairs, so although he was Irish, a local Jersey mafia don adopted him as a mascot for landscaping or driving hijacked trucks from Point A to Point B. His mother, when he was small, used to take him to a Catholic cemetery to pee on the graves of the nuns who’d mistreated her at their orphanage, slamming her fingers in a door, and so forth—another memory his combat stint in Korea didn’t soften. In reparative interludes we made friends—the verb is kinetic—till the pistol he carried no longer tempted him toward Russian roulette. But he still drove customers away if he could, skinning the raccoons and coyotes he trapped on the sandwich board at his greasy spoon, so that if people wandered in asking for a pastrami hero, John could point at the naked carcass he was cutting at: “Pick your part!” It decreased sales. (...)
I like carbonation in my friends: out-on-a-limb idealism or a traveler’s itch, a shivery past or libertarian streak, with frostbite scars, perhaps, or a veteran’s fatalistic flinch when a car backfires. The “vibes” people speak of seem natural to me. When you intuit that somebody you hadn’t expected is approaching before they reach your door, or realize that a person, silent, elsewhere in the house, needs a hug, it’s not “extrasensory perception” but telepathy to antennae we haven’t pinpointed, a force field we haven’t quantified, which also warns us, when we’re hurrying down a city street, about unseen dangers around the corner: potential collisions, muggers, flimflammers, whatever.
by Edward Hoagland, The American Scholar | Read more:
Photo by Maureen Lunn
Physics’s Pangolin
Theoretical physics is beset by a paradox that remains as mysterious today as it was a century ago: at the subatomic level things are simultaneously particles and waves. Like the duck-rabbit illusion first described in 1899 by the Polish-born American psychologist Joseph Jastrow, subatomic reality appears to us as two different categories of being.
But there is another paradox in play. Physics itself is riven by the competing frameworks of quantum theory and general relativity, whose differing descriptions of our world eerily mirror the wave-particle tension. When it comes to the very big and the extremely small, physical reality appears to be not one thing, but two. Where quantum theory describes the subatomic realm as a domain of individual quanta, all jitterbug and jumps, general relativity depicts happenings on the cosmological scale as a stately waltz of smooth flowing space-time. General relativity is like Strauss — deep, dignified and graceful. Quantum theory, like jazz, is disconnected, syncopated, and dazzlingly modern.
Physicists are deeply aware of the schizophrenic nature of their science and long to find a synthesis, or unification. Such is the goal of a so-called ‘theory of everything’. However, to non-physicists, these competing lines of thought, and the paradoxes they entrain, can seem not just bewildering but absurd. In my experience as a science writer, no other scientific discipline elicits such contradictory responses. (...)
Many physicists are Platonists, at least when they talk to outsiders about their field. They believe that the mathematical relationships they discover in the world about us represent some kind of transcendent truth existing independently from, and perhaps a priori to, the physical world. In this way of seeing, the universe came into being according to a mathematical plan, what the British physicist Paul Davies has called ‘a cosmic blueprint’. Discovering this ‘plan’ is a goal for many theoretical physicists and the schism in the foundation of their framework is thus intensely frustrating. It’s as if the cosmic architect has designed a fiendish puzzle in which two apparently incompatible parts must be fitted together. Both are necessary, for both theories make predictions that have been verified to a dozen or so decimal places, and it is on the basis of these theories that we have built such marvels as microchips, lasers, and GPS satellites.
Quite apart from the physical tensions that exist between them, relativity and quantum theory each pose philosophical problems. Are space and time fundamental qualities of the universe, as general relativity suggests, or are they byproducts of something even more basic, something that might arise from a quantum process? Looking at quantum mechanics, huge debates swirl around the simplest situations. Does the universe split into multiple copies of itself every time an electron changes orbit in an atom, or every time a photon of light passes through a slit? Some say yes, others say absolutely not.
Theoretical physicists can’t even agree on what the celebrated waves of quantum theory mean. What is doing the ‘waving’? Are the waves physically real, or are they just mathematical representations of probability distributions? Are the ‘particles’ guided by the ‘waves’? And, if so, how? The dilemma posed by wave-particle duality is the tip of an epistemological iceberg on which many ships have been broken and wrecked.
Undeterred, some theoretical physicists are resorting to increasingly bold measures in their attempts to resolve these dilemmas. Take the ‘many-worlds’ interpretation of quantum theory, which proposes that every time a subatomic action takes place the universe splits into multiple, slightly different, copies of itself, with each new ‘world’ representing one of the possible outcomes.
When this idea was first proposed in 1957 by the American physicist Hugh Everett, it was considered an almost lunatic-fringe position. Even 20 years later, when I was a physics student, many of my professors thought it was a kind of madness to go down this path. Yet in recent years the many-worlds position has become mainstream. The idea of a quasi-infinite, ever-proliferating array of universes has been given further credence as a result of being taken up by string theorists, who argue that every mathematically possible version of the string theory equations corresponds to an actually existing universe, and estimate that there are 10 to the power of 500 different possibilities. To put this in perspective: physicists believe that in our universe there are approximately 10 to the power of 80 subatomic particles. In string cosmology, the totality of existing universes exceeds the number of particles in our universe by more than 400 orders of magnitude.
Nothing in our experience compares to this unimaginably vast number. Every universe that can be mathematically imagined within the string parameters — including ones in which you exist with a prehensile tail, to use an example given by the American string theorist Brian Greene — is said to be manifest somewhere in a vast supra-spatial array ‘beyond’ the space-time bubble of our own universe.
What is so epistemologically daring here is that the equations are taken to be the fundamental reality. The fact that the mathematics allows for gazillions of variations is seen to be evidence for gazillions of actual worlds.
This kind of reification of equations is precisely what strikes some humanities scholars as childishly naive. At the very least, it raises serious questions about the relationship between our mathematical models of reality, and reality itself.
by Margaret Wertheim, Aeon | Read more:
Illustration by Claire Scully
But there is another paradox in play. Physics itself is riven by the competing frameworks of quantum theory and general relativity, whose differing descriptions of our world eerily mirror the wave-particle tension. When it comes to the very big and the extremely small, physical reality appears to be not one thing, but two. Where quantum theory describes the subatomic realm as a domain of individual quanta, all jitterbug and jumps, general relativity depicts happenings on the cosmological scale as a stately waltz of smooth flowing space-time. General relativity is like Strauss — deep, dignified and graceful. Quantum theory, like jazz, is disconnected, syncopated, and dazzlingly modern.Physicists are deeply aware of the schizophrenic nature of their science and long to find a synthesis, or unification. Such is the goal of a so-called ‘theory of everything’. However, to non-physicists, these competing lines of thought, and the paradoxes they entrain, can seem not just bewildering but absurd. In my experience as a science writer, no other scientific discipline elicits such contradictory responses. (...)
Many physicists are Platonists, at least when they talk to outsiders about their field. They believe that the mathematical relationships they discover in the world about us represent some kind of transcendent truth existing independently from, and perhaps a priori to, the physical world. In this way of seeing, the universe came into being according to a mathematical plan, what the British physicist Paul Davies has called ‘a cosmic blueprint’. Discovering this ‘plan’ is a goal for many theoretical physicists and the schism in the foundation of their framework is thus intensely frustrating. It’s as if the cosmic architect has designed a fiendish puzzle in which two apparently incompatible parts must be fitted together. Both are necessary, for both theories make predictions that have been verified to a dozen or so decimal places, and it is on the basis of these theories that we have built such marvels as microchips, lasers, and GPS satellites.
Quite apart from the physical tensions that exist between them, relativity and quantum theory each pose philosophical problems. Are space and time fundamental qualities of the universe, as general relativity suggests, or are they byproducts of something even more basic, something that might arise from a quantum process? Looking at quantum mechanics, huge debates swirl around the simplest situations. Does the universe split into multiple copies of itself every time an electron changes orbit in an atom, or every time a photon of light passes through a slit? Some say yes, others say absolutely not.
Theoretical physicists can’t even agree on what the celebrated waves of quantum theory mean. What is doing the ‘waving’? Are the waves physically real, or are they just mathematical representations of probability distributions? Are the ‘particles’ guided by the ‘waves’? And, if so, how? The dilemma posed by wave-particle duality is the tip of an epistemological iceberg on which many ships have been broken and wrecked.
Undeterred, some theoretical physicists are resorting to increasingly bold measures in their attempts to resolve these dilemmas. Take the ‘many-worlds’ interpretation of quantum theory, which proposes that every time a subatomic action takes place the universe splits into multiple, slightly different, copies of itself, with each new ‘world’ representing one of the possible outcomes.
When this idea was first proposed in 1957 by the American physicist Hugh Everett, it was considered an almost lunatic-fringe position. Even 20 years later, when I was a physics student, many of my professors thought it was a kind of madness to go down this path. Yet in recent years the many-worlds position has become mainstream. The idea of a quasi-infinite, ever-proliferating array of universes has been given further credence as a result of being taken up by string theorists, who argue that every mathematically possible version of the string theory equations corresponds to an actually existing universe, and estimate that there are 10 to the power of 500 different possibilities. To put this in perspective: physicists believe that in our universe there are approximately 10 to the power of 80 subatomic particles. In string cosmology, the totality of existing universes exceeds the number of particles in our universe by more than 400 orders of magnitude.
Nothing in our experience compares to this unimaginably vast number. Every universe that can be mathematically imagined within the string parameters — including ones in which you exist with a prehensile tail, to use an example given by the American string theorist Brian Greene — is said to be manifest somewhere in a vast supra-spatial array ‘beyond’ the space-time bubble of our own universe.
What is so epistemologically daring here is that the equations are taken to be the fundamental reality. The fact that the mathematics allows for gazillions of variations is seen to be evidence for gazillions of actual worlds.
This kind of reification of equations is precisely what strikes some humanities scholars as childishly naive. At the very least, it raises serious questions about the relationship between our mathematical models of reality, and reality itself.
by Margaret Wertheim, Aeon | Read more:
Illustration by Claire Scully
Thursday, June 20, 2013
Fake Shop Fronts in Ireland
[ed. Economic Potemkin Villages]
Northern Ireland's government has spent £2m (€2.3m) tackling dereliction over the past two years, the environment department said.
Some buildings have been demolished and others have been given a facelift in an attempt to make areas more attractive.
Almost a quarter of "dereliction funds" were freed up for local councillors in Co Fermanagh in anticipation of Britain hosting the annual Group of Eight leaders’ summit there on 17-18 June.
More than 100 properties have been spruced up.
In the one-street town of Belcoo, the changes are merely cosmetic.
At a former butcher's shop, stickers applied to the windows show a packed meat counter and give the impression that business is booming.
Across the street, another empty unit has been given a makeover to look like a thriving office supply shop. Locals are unimpressed.
"The shop fronts are cosmetic surgery for serious wounds. They are looking after the banks instead of saving good businesses," said Kevin Maguire, 62, an unemployed man who has lived all his life in Belcoo.
"Where would you see a shop front in Northern Ireland like this anyway? It's more like something you'd find in Belgravia or Chelsea," he said, referring to elite districts of London.
The fakes are not the first of their kind in Northern Ireland.
Last year, smart-looking shop fronts appeared in a series of derelict Belfast stores along the main route from the city centre to the grand Stormont parliament building.
"Northern Ireland is in the international spotlight so it is entirely right that we should portray it in the best light possible," Northern Ireland Environment Minister Alex Attwood said in a statement.
by RTE News/Ireland | Read more:
Image: uncredited
Sizing Up Big Data, Broadening Beyond the Internet
In his young career, Jeffrey Hammerbacher has been a scout on the frontiers of the data economy.
In 2005, Mr. Hammerbacher, then a freshly minted Harvard graduate, did what many math and computing whizzes did. He went to Wall Street as a “quant,” building math models for complex financial products.
Looking for a better use for his skills, Mr. Hammerbacher departed to Silicon Valley less than a year later and joined Facebook. He started a team that began to mine the vast amounts of social network data Facebook was collecting for insights on how to tweak the service and target ads. He called himself and his co-workers “data scientists,” a term that has since become the hottest of job categories.
Facebook was a fabulous petri dish for data science. Yet after two and a half years, Mr. Hammerbacher decided it was time to move on, beyond social networks and Internet advertising. He became a founder of Cloudera, a start-up that makes software tools for data scientists.
Then, starting last summer, Mr. Hammerbacher, who is now 30, embarked on a very different professional path. He joined the Mount Sinai School of Medicine in Manhattan as an assistant professor, exploring genetic and other medical data in search of breakthroughs in disease modeling and treatment.
The goal, Mr. Hammerbacher said, is “to turn medicine into the land of the quants.”
The story is the same in one field after another, in science, politics, crime prevention, public health, sports and industries as varied as energy and advertising. All are being transformed by data-driven discovery and decision-making. The pioneering consumer Internet companies, like Google, Facebook and Amazon, were just the start, experts say. Today, data tools and techniques are used for tasks as varied as predicting neighborhood blocks where crimes are most likely to occur and injecting intelligence into hulking industrial machines, like electrical power generators.
Big Data is the shorthand label for the phenomenon, which embraces technology, decision-making and public policy. Supplying the technology is a fast-growing market, increasing at more than 30 percent a year and likely to reach $24 billion by 2016, according to a forecast by IDC, a research firm. All the major technology companies, and a host of start-ups, are aggressively pursuing the business.
Demand is brisk for people with data skills. The McKinsey Global Institute, the research arm of the consulting firm, projects that the United States needs 140,000 to 190,000 more workers with “deep analytical” expertise and 1.5 million more data-literate managers, whether retrained or hired, by 2020.
Yet the surveillance potential of Big Data, with every click stream, physical movement and commercial transaction monitored and analyzed, would strain the imagination of George Orwell. So what will be society’s ground rules for the collection and use of data? How do we weigh the trade-offs involving privacy, commerce and security? Those issues are just beginning to be addressed. The debate surrounding the recent disclosure that the National Security Agency has been secretly stockpiling telephone call logs of Americans and poring through e-mail and other data from major Internet companies is merely an early round.
Big Data is a vague term, used loosely, if often, these days. But put simply, the catchall phrase means three things. First, it is a bundle of technologies. Second, it is a potential revolution in measurement. And third, it is a point of view, or philosophy, about how decisions will be — and perhaps should be — made in the future.
In 2005, Mr. Hammerbacher, then a freshly minted Harvard graduate, did what many math and computing whizzes did. He went to Wall Street as a “quant,” building math models for complex financial products.
Looking for a better use for his skills, Mr. Hammerbacher departed to Silicon Valley less than a year later and joined Facebook. He started a team that began to mine the vast amounts of social network data Facebook was collecting for insights on how to tweak the service and target ads. He called himself and his co-workers “data scientists,” a term that has since become the hottest of job categories.Facebook was a fabulous petri dish for data science. Yet after two and a half years, Mr. Hammerbacher decided it was time to move on, beyond social networks and Internet advertising. He became a founder of Cloudera, a start-up that makes software tools for data scientists.
Then, starting last summer, Mr. Hammerbacher, who is now 30, embarked on a very different professional path. He joined the Mount Sinai School of Medicine in Manhattan as an assistant professor, exploring genetic and other medical data in search of breakthroughs in disease modeling and treatment.
The goal, Mr. Hammerbacher said, is “to turn medicine into the land of the quants.”
The story is the same in one field after another, in science, politics, crime prevention, public health, sports and industries as varied as energy and advertising. All are being transformed by data-driven discovery and decision-making. The pioneering consumer Internet companies, like Google, Facebook and Amazon, were just the start, experts say. Today, data tools and techniques are used for tasks as varied as predicting neighborhood blocks where crimes are most likely to occur and injecting intelligence into hulking industrial machines, like electrical power generators.
Big Data is the shorthand label for the phenomenon, which embraces technology, decision-making and public policy. Supplying the technology is a fast-growing market, increasing at more than 30 percent a year and likely to reach $24 billion by 2016, according to a forecast by IDC, a research firm. All the major technology companies, and a host of start-ups, are aggressively pursuing the business.
Demand is brisk for people with data skills. The McKinsey Global Institute, the research arm of the consulting firm, projects that the United States needs 140,000 to 190,000 more workers with “deep analytical” expertise and 1.5 million more data-literate managers, whether retrained or hired, by 2020.
Yet the surveillance potential of Big Data, with every click stream, physical movement and commercial transaction monitored and analyzed, would strain the imagination of George Orwell. So what will be society’s ground rules for the collection and use of data? How do we weigh the trade-offs involving privacy, commerce and security? Those issues are just beginning to be addressed. The debate surrounding the recent disclosure that the National Security Agency has been secretly stockpiling telephone call logs of Americans and poring through e-mail and other data from major Internet companies is merely an early round.
Big Data is a vague term, used loosely, if often, these days. But put simply, the catchall phrase means three things. First, it is a bundle of technologies. Second, it is a potential revolution in measurement. And third, it is a point of view, or philosophy, about how decisions will be — and perhaps should be — made in the future.
by Steve Lohr, NY Times | Read more:
Image: uncredited
Financial Sector Thinks It’s About Ready To Ruin World Again
Representatives from all major banking and investment institutions cited recent increases in consumer spending, rebounding home prices, and a stabilizing unemployment rate as confirmation that the time had once again come to inflict another round of catastrophic financial losses on individuals and businesses worldwide.
“It’s been about five or six years since we last crippled every major market on the planet, so it seems like the time is right for us to get back out there and start ruining the lives of billions of people again,” said Goldman Sachs CEO Lloyd Blankfein. “We gave it some time and let everyone get a little comfortable, and now we’re looking to get back on the old horse, shatter some consumer confidence, and flat-out kill any optimism for a stable global economy for years to come.”
“People are beginning to feel at ease spending money and investing in their futures again,” Blankfein continued. “That’s the perfect time to step in and do what we do best: rip the heart right out of the world’s economy.”
According to sources, the overwhelming majority of investment bankers are “ready to get the ball rolling” by approving a host of complex and poorly understood debt-backed securities that are doomed to quickly default, as well as issuing startlingly high-risk loans certain to drive thousands of companies into insolvency.
Top-level executives also told reporters that when it comes to depleting the life savings of millions of people and sending every major national economy into a tailspin, they feel “refreshed and raring to go.”
“The other day I actually overheard someone on the sidewalk utter the words ‘I’m saving up for retirement,’ and right away I thought to myself, ‘Well, time to get down to work,’” said Morgan Stanley chairman James P. Gorman, adding that the increasing number of individuals entertaining ideas of starting their own businesses or buying houses was the financial sector’s cue to set off another devastating global recession. “We’re definitely thinking on a huge scale again, because we all really enjoy toying with the livelihoods of millions of people overseas and forcing them to wonder why reckless, split-second decisions made thousands of miles away dictate their whole country’s socioeconomic future.”
“Plus, it’ll be nice to finally wipe out the Euro once and for all this time,” Gorman added.
While most private equity firms, investment banks, and hedge funds are reportedly still undecided on the precise route to take in order to torpedo the job market and crash all international stock exchanges, sources confirmed they are nearly in position to resume gambling away trillions of dollars belonging to the American populace.
“We’ve got a lot of options on the table; it’s just a matter of picking which one we want to use to paralyze every single sector of the world economy,” said Capital One executive vice president Peter Schnall. “We already burst the dot-com and housing bubbles, so this time we can maybe mix it up by popping the education bubble and shattering the lives of everyone with outstanding student loans. Or maybe we’ll artificially inflate prices of stocks in social media companies and then pull the rug out, bankrupting every investor tied to companies like Facebook and Twitter. Or do both.”
“On second thought, maybe we’ll wipe out the housing market again too, just for the hell of it,” Schnall quickly added. “Might as well, right?”
by The Onion | Read more:
Image: uncredited
John Mayer
[ed. Single from his new album. Nice song, but I'll never be able to listen to it again without thinking about the so-called exercise routine "prancercise" (which I'd never heard of before). As this article states, the intro is quite bizzare. Here's an alternate version if you find this one too troubling.]
So You've Decided to Drink More Water
[ed. Repost. I've been trying to do this, maybe not eight glasses a day but a couple of bottles at least. Charming essay.]
On the first day, you make the decision. “I’m going to drink more water,” you say. “Eight glasses a day, to start with. Maybe more.” Suddenly you realize the break room has gone silent. The sun sinks below the horizon as a sign of respect. You begin right away, finishing the cup of water already in your hand.
On the first day, you make the decision. “I’m going to drink more water,” you say. “Eight glasses a day, to start with. Maybe more.” Suddenly you realize the break room has gone silent. The sun sinks below the horizon as a sign of respect. You begin right away, finishing the cup of water already in your hand.
The next morning, you open your eyes after eight uninterrupted hours of deep sleep. The sun spills through the window onto the fresh white linens on your bed, and a glass of water sits on your nightstand, sparkling in the morning light. You drink it and realize that you no longer have the urge to eat breakfast. The water is enough.Later, on the subway, a beautiful, serene older woman comes over to you and lays her gloved hand gently on your arm. “Your skin,” she murmurs. “It’s positively glowing. So fresh. So luminous. May I ask — it’s water, isn’t it?” You smile. She plants a tender kiss on your forehead and glides away.
A week passes. You go in for your yearly physical. “I don’t understand,” your doctor mutters as she looks at your chart. “A woman your age — it just doesn’t make any sense.” You shift nervously on the papered table. “Your body doesn’t have a single toxin. They’ve all disappeared. It’s as if something just ... flushed them away overnight.” She shakes her head. “I’m not even sure how to tell you this. Have you found yourself experiencing a decreased appetite lately? Difficulty finishing meals?” You nod, unsure of where this is going. “This is extremely rare, but your entire digestive system has been transmuted into pure mother-of-pearl.”
“I see,” you say slowly. You pull a bottle of water out of your purse and take a sip, and her face breaks into a relieved smile. “You didn’t tell me you’d started drinking water! Eight glasses of water a day? Of course! Is that why every inch of your skin is radiating a soft and healthy glow?” You nod again. She laughs and takes off her stethoscope. “I can see we won’t be needing this anymore!”
You start to carry water with you everywhere. Sometimes after getting home from work you drink from the kitchen faucet in great, hiccuping gulps. In no time at all you’ve moved from eight cups a day to a few gallons. Anyone else might have died of hyponatremia by now, but not you. You only grow stronger and more beautiful.
Every publication in the world, from The Lancet to Maxim to Mother Jones, wants to know your secret. “Tell us,” they beg you. Their eyes are hungry (thirsty?). “We have to know. How do you do it?” You sigh exquisitely. “I just like to drink water,” you tell them. Still their eyes bore into yours, pleading. “Sometimes I put a slice of cucumber or lemon in it. For the taste.” Upon hearing these words, an envious Anna Wintour sets herself on fire.
Grown men sink to their knees as you pass, their faces crumpling into shameless sobs. Mothers lift their children up to you in mute and expectant appeal. You bless them all.
Every country in the world bans the drinking of any beverage other than water. All droughts cease; deserts erupt in a riot of frondescence. You twirl in delight, slowly at first, round and round, as the entire world joins you in drinking more water. Everyone is drinking more water now. A soft, cool rain begins to fall. “She’s the one,” you hear someone whisper before you ascend to a plane of existence where human vocalizations no longer mean anything to you. “The one who drinks a lot of water.”
by Mallory Ortberg, The Hairpin | Read more:
Image: credit misplaced
The Science of Why We Don’t Believe Science
"A man with a conviction is a hard man to change. Tell him you disagree and he turns away. Show him facts or figures and he questions your sources. Appeal to logic and he fails to see your point.” So wrote the celebrated Stanford University psychologist Leon Festinger, in a passage that might have been referring to climate change denial—the persistent rejection, on the part of so many Americans today, of what we know about global warming and its human causes. But it was too early for that—this was the 1950s—and Festinger was actually describing a famous case study in psychology.
Festinger and several of his colleagues had infiltrated the Seekers, a small Chicago-area cult whose members thought they were communicating with aliens—including one, “Sananda,” who they believed was the astral incarnation of Jesus Christ. The group was led by Dorothy Martin, a Dianetics devotee who transcribed the interstellar messages through automatic writing.
Through her, the aliens had given the precise date of an Earth-rending cataclysm: December 21, 1954. Some of Martin’s followers quit their jobs and sold their property, expecting to be rescued by a flying saucer when the continent split asunder and a new sea swallowed much of the United States. The disciples even went so far as to remove brassieres and rip zippers out of their trousers—the metal, they believed, would pose a danger on the spacecraft.
Festinger and his team were with the cult when the prophecy failed. First, the “boys upstairs” (as the aliens were sometimes called) did not show up and rescue the Seekers. Then December 21 arrived without incident. It was the moment Festinger had been waiting for: How would people so emotionally invested in a belief system react, now that it had been soundly refuted?
At first, the group struggled for an explanation. But then rationalization set in. A new message arrived, announcing that they’d all been spared at the last minute. Festinger summarized the extraterrestrials’ new pronouncement: “The little group, sitting all night long, had spread so much light that God had saved the world from destruction.” Their willingness to believe in the prophecy had saved Earth from the prophecy!
From that day forward, the Seekers, previously shy of the press and indifferent toward evangelizing, began to proselytize. “Their sense of urgency was enormous,” wrote Festinger. The devastation of all they had believed had made them even more certain of their beliefs.
In the annals of denial, it doesn’t get much more extreme than the Seekers. They lost their jobs, the press mocked them, and there were efforts to keep them away frome mpressionable young minds. But while Martin’s space cult might lie at the far end of the spectrum of human self-delusion, there’s plenty to go around. And since Festinger’s day, an array of new discoveries in psychology and neuroscience has further demonstrated how our preexisting beliefs, far more than any new facts, can skew our thoughts and even color what we consider our most dispassionate and logical conclusions. This tendency toward so-called “motivated reasoning” helps explain why we find groups so polarized over matters where the evidence is so unequivocal: climate change, vaccines, “death panels,” the birthplace and religion of the president (PDF), and much else. It would seem that expecting people to be convinced by the facts flies in the face of, you know, the facts.
The theory of motivated reasoning builds on a key insight of modern neuroscience (PDF): Reasoning is actually suffused with emotion (or what researchers often call “affect”). Not only are the two inseparable, but our positive or negative feelings about people, things, and ideas arise much more rapidly than our conscious thoughts, in a matter of milliseconds—fast enough to detect with an EEG device, but long before we’re aware of it. That shouldn’t be surprising: Evolution required us to react very quickly to stimuli in our environment. It’s a “basic human survival skill,” explains political scientist Arthur Lupia of the University of Michigan. We push threatening information away; we pull friendly information close. We apply fight-or-flight reflexes not only to predators, but to data itself.
Consider a person who has heard about a scientific discovery that deeply challenges her belief in divine creation—a new hominid, say, that confirms our evolutionary origins. What happens next, explains political scientist Charles Taber of Stony Brook University, is a subconscious negative response to the new information—and that response, in turn, guides the type of memories and associations formed in the conscious mind. “They retrieve thoughts that are consistent with their previous beliefs,” says Taber, “and that will lead them to build an argument and challenge what they’re hearing.”
In other words, when we think we’re reasoning, we may instead be rationalizing. Or to use an analogy offered by University of Virginia psychologist Jonathan Haidt: We may think we’re being scientists, but we’re actually being lawyers (PDF). Our “reasoning” is a means to a predetermined end—winning our “case”—and is shot through with biases. They include “confirmation bias,” in which we give greater heed to evidence and arguments that bolster our beliefs, and “disconfirmation bias,” in which we expend disproportionate energy trying to debunk or refute views and arguments that we find uncongenial.
That’s a lot of jargon, but we all understand these mechanisms when it comes to interpersonal relationships. If I don’t want to believe that my spouse is being unfaithful, or that my child is a bully, I can go to great lengths to explain away behavior that seems obvious to everybody else—everybody who isn’t too emotionally invested to accept it, anyway. That’s not to suggest that we aren’t also motivated to perceive the world accurately—we are. Or that we never change our minds—we do. It’s just that we have other important goals besides accuracy—including identity affirmation and protecting one’s sense of self—and often those make us highly resistant to changing our beliefs when the facts say we should.
Festinger and several of his colleagues had infiltrated the Seekers, a small Chicago-area cult whose members thought they were communicating with aliens—including one, “Sananda,” who they believed was the astral incarnation of Jesus Christ. The group was led by Dorothy Martin, a Dianetics devotee who transcribed the interstellar messages through automatic writing.Through her, the aliens had given the precise date of an Earth-rending cataclysm: December 21, 1954. Some of Martin’s followers quit their jobs and sold their property, expecting to be rescued by a flying saucer when the continent split asunder and a new sea swallowed much of the United States. The disciples even went so far as to remove brassieres and rip zippers out of their trousers—the metal, they believed, would pose a danger on the spacecraft.
Festinger and his team were with the cult when the prophecy failed. First, the “boys upstairs” (as the aliens were sometimes called) did not show up and rescue the Seekers. Then December 21 arrived without incident. It was the moment Festinger had been waiting for: How would people so emotionally invested in a belief system react, now that it had been soundly refuted?
At first, the group struggled for an explanation. But then rationalization set in. A new message arrived, announcing that they’d all been spared at the last minute. Festinger summarized the extraterrestrials’ new pronouncement: “The little group, sitting all night long, had spread so much light that God had saved the world from destruction.” Their willingness to believe in the prophecy had saved Earth from the prophecy!
From that day forward, the Seekers, previously shy of the press and indifferent toward evangelizing, began to proselytize. “Their sense of urgency was enormous,” wrote Festinger. The devastation of all they had believed had made them even more certain of their beliefs.
In the annals of denial, it doesn’t get much more extreme than the Seekers. They lost their jobs, the press mocked them, and there were efforts to keep them away frome mpressionable young minds. But while Martin’s space cult might lie at the far end of the spectrum of human self-delusion, there’s plenty to go around. And since Festinger’s day, an array of new discoveries in psychology and neuroscience has further demonstrated how our preexisting beliefs, far more than any new facts, can skew our thoughts and even color what we consider our most dispassionate and logical conclusions. This tendency toward so-called “motivated reasoning” helps explain why we find groups so polarized over matters where the evidence is so unequivocal: climate change, vaccines, “death panels,” the birthplace and religion of the president (PDF), and much else. It would seem that expecting people to be convinced by the facts flies in the face of, you know, the facts.
The theory of motivated reasoning builds on a key insight of modern neuroscience (PDF): Reasoning is actually suffused with emotion (or what researchers often call “affect”). Not only are the two inseparable, but our positive or negative feelings about people, things, and ideas arise much more rapidly than our conscious thoughts, in a matter of milliseconds—fast enough to detect with an EEG device, but long before we’re aware of it. That shouldn’t be surprising: Evolution required us to react very quickly to stimuli in our environment. It’s a “basic human survival skill,” explains political scientist Arthur Lupia of the University of Michigan. We push threatening information away; we pull friendly information close. We apply fight-or-flight reflexes not only to predators, but to data itself.
Consider a person who has heard about a scientific discovery that deeply challenges her belief in divine creation—a new hominid, say, that confirms our evolutionary origins. What happens next, explains political scientist Charles Taber of Stony Brook University, is a subconscious negative response to the new information—and that response, in turn, guides the type of memories and associations formed in the conscious mind. “They retrieve thoughts that are consistent with their previous beliefs,” says Taber, “and that will lead them to build an argument and challenge what they’re hearing.”
In other words, when we think we’re reasoning, we may instead be rationalizing. Or to use an analogy offered by University of Virginia psychologist Jonathan Haidt: We may think we’re being scientists, but we’re actually being lawyers (PDF). Our “reasoning” is a means to a predetermined end—winning our “case”—and is shot through with biases. They include “confirmation bias,” in which we give greater heed to evidence and arguments that bolster our beliefs, and “disconfirmation bias,” in which we expend disproportionate energy trying to debunk or refute views and arguments that we find uncongenial.
That’s a lot of jargon, but we all understand these mechanisms when it comes to interpersonal relationships. If I don’t want to believe that my spouse is being unfaithful, or that my child is a bully, I can go to great lengths to explain away behavior that seems obvious to everybody else—everybody who isn’t too emotionally invested to accept it, anyway. That’s not to suggest that we aren’t also motivated to perceive the world accurately—we are. Or that we never change our minds—we do. It’s just that we have other important goals besides accuracy—including identity affirmation and protecting one’s sense of self—and often those make us highly resistant to changing our beliefs when the facts say we should.
by Chris Mooney, Mother Jones | Read more:
Image: Jonathan Rosen
A Dozen Simple Ways to Serve the Perfect Scallop
Much more difficult than cooking scallops is buying scallops. As with most seafood these days, unless you’re on the boat yourself — or have a trustworthy source — it’s hard to know exactly what you’re getting. Because scallops are often soaked in a phosphate solution that plumps them up with water (therefore making added water part of the selling price), it’s important to look for scallops that are labeled “dry” or “dry-packed.” A waterlogged scallop doesn’t sear well, and a phosphate-marinated scallop may taste like soap, especially when it’s raw, so make sure to ask for dry.
In most parts of the country, at most times of year, you want sea scallops, the big ones that are harvested year round.
True bay scallops — possibly the best and certainly the priciest — are mostly caught off Long Island and Cape Cod in the winter. (Other “bay” scallops, like the calico or other smallish varieties, are not really worth buying. West Coast pink scallops are lovely, if you can find them.) Many scallops are also sold individually quick-frozen (I.Q.F.), but opt for fresh if you can.
One note on preparation: Err on the side of undercooking. Take the scallops off the grill before they’re opaque all the way through. If you undercook a scallop, it will still be delicious. If you overcook a scallop, it will get rubbery and you may get sad.
Buying tasty scallops is more than half the battle. Treating them simply once you get them to the kitchen is the rest.
by Mark Bittman, NY Times | Read more (12 Recipes):
Photographs by Sam Kaplan for The New York Times; Food stylist: Suzanne Lenzer.
Wednesday, June 19, 2013
How Fat has Become a Political Issue
It was inspired by the death of my older brother from complications of morbid obesity in 2009. The novel begins with a sister picking up her big brother at the airport and failing to recognize him. Her once lanky, handsome elder sibling has shown up weighing hundreds more pounds than when they last met. Like my previous novel, We Need to Talk About Kevin, this book is partly a psychological mystery, asking, “What the hell happened?”
But the story inside a book is distinct from the story of the book’s publication. As of the first interview for the British promotion of Big Brother, the media’s focus rapidly shifted from the fiction (who cares about that?) to the author: when I eat, what I eat, how much I eat, how much I exercise, which exercises I do, and how many repetitions.
That first time, I had been tolerant of these curiously personal, positively mechanical questions on the assumption that in the profile this information would somehow be tied in with the themes I explore in the novel: the many reasons we eat other than for mere nutrition, the roles food plays in social and domestic dynamics, the complex relationship between the body and the self, the moral baggage we load on weight, and the alarming degree to which we now “size each other up” and make character judgments on the basis of whether someone is fat or thin.
But no. That interview and the subsequent articles it spawned elsewhere didn’t explore more philosophical matters, but were purely nosy and voyeuristic. Journalists and online commentators were fascinated by – and keenly suspicious of – the routines by which I maintain my private, 5-foot-2 physical plant. (In respect to my not especially interesting exercise habits, I was, it was implied in more than one paper, a liar.) Irrelevant information about the author’s dining proclivities even contaminated more than one review.
The publicity became yet another illustration of the problem the book explores. In an era saturated with the visual image, people in the public eye necessarily offer themselves up for scrutiny of their waistlines. The expression “public figure” has taken on a peculiar literalism, for fat has gone political. Being wide or narrow effectively lands you on one side or another of a violent cultural divide.
To appreciate just how loaded body size has become, let’s take two case studies: U.S. President Barack Obama and New Jersey Governor Chris Christie. As they toured the Jersey shore’s newly rebuilt boardwalk last week, the President and the Republican who may have designs on his office displayed starkly contrasting physical versions of Big Men in government.
Despite all the multicourse state dinners, Mr. Obama remains a Slim Jim. Despite having lost 40 pounds since February, Mr. Christie remains a meatball hero.
Since going public about his lap-band procedure, Mr. Christie has insisted that his weight-loss surgery was motivated solely by private concerns: He owes it to his family to protect his health. Yet he is canny enough to realize that his contours would be an issue were he to run in 2016, and the shape of the high-profile silhouette isn’t as simple a business as thin/good, fat/bad.
Weight is entangled with class. Long gone are the days when beefiness was a badge of wealth and prosperity. Today’s elites are thin – which is why you pay through the nose at top-end restaurants for three leaves of arugula and a few flakes of fish, while all-you-can-eat buffets are dirt-cheap.
Among Mr. Obama’s red-state detractors, the President’s slight build may mark him as suspect even more so than his race. Educated salad-eaters on the coasts recognize in Mr. Obama a fellow traveller, but for pork lovers in the heartland that tall, svelte nattiness connotes a sense of superiority and an aloofness from ordinary folks. The modesty of the President’s real origins gets cancelled out.
(Fortunately, his wife’s comely, fit but bigger-boned frame provides a balance to this impression.)
For Mr. Christie, being flat-out fat has not stopped him from being elected governor of a populous state nor from being courted for the Republican nomination, and hitherto his heft may have proved an advantage. Fat makes him seem more down-to-earth, more a man of the people.
Though the governor is a lawyer whose background is middle-income, being big as a house seems to suggest that he is just a regular guy, an unpretentious Jersey boy with an instinctive grasp of the needs of the struggling. You’d like to have a beer with him. He’d help himself to a handful if you ordered peanuts.
Weight is also entangled with character. A lean physique implies a tendency to discipline, self-control and purposiveness. Culturally, we link slenderness not only to success but also to judgmentalism, joylessness, uptightness and vanity.
Men who are thin can seem prissy or effeminate. Mr. Obama’s narrowness is compensated by a resonant voice and gift for oratory, which lend his presence gravitas. Otherwise, he might seem to lack substance in a metaphorical sense. No one in politics courts a reputation as a “lightweight.”
Fat among the hoi polloi may appear to betray sloth, laziness and self-indulgence, but for male politicians displays of appetite can pay dividends – which is why candidates are often seen bolting down hot dogs and barbecue sandwiches on the campaign trail. Appetite indicates a zest for life, ambition, an appealing allegorical hunger for more than pot stickers – even, subtly, high levels of testosterone.
Though the governor is a lawyer whose background is middle-income, being big as a house seems to suggest that he is just a regular guy, an unpretentious Jersey boy with an instinctive grasp of the needs of the struggling. You’d like to have a beer with him. He’d help himself to a handful if you ordered peanuts.
Weight is also entangled with character. A lean physique implies a tendency to discipline, self-control and purposiveness. Culturally, we link slenderness not only to success but also to judgmentalism, joylessness, uptightness and vanity.
Men who are thin can seem prissy or effeminate. Mr. Obama’s narrowness is compensated by a resonant voice and gift for oratory, which lend his presence gravitas. Otherwise, he might seem to lack substance in a metaphorical sense. No one in politics courts a reputation as a “lightweight.”
Fat among the hoi polloi may appear to betray sloth, laziness and self-indulgence, but for male politicians displays of appetite can pay dividends – which is why candidates are often seen bolting down hot dogs and barbecue sandwiches on the campaign trail. Appetite indicates a zest for life, ambition, an appealing allegorical hunger for more than pot stickers – even, subtly, high levels of testosterone.
by Lionel Shriver, Globe and Mail | Read more:
Image: Katy Lemay
Q&A: Harlan Ellison
[ed. Wow, somebody got an actual interview with Harlan Ellison. I've been a fan since college after reading I Have No Mouth and I Must Scream, and The Glass Teat. Enjoy... one of the greatest science fiction writers of all time.]
DW: Harlan, first of all, can you confirm that you are indeed the great Harlan Ellison?HE: For all my sins – and I assure you, the only thing that has ever held me back from God-like greatness is my humility – I am the Harlan Ellison, the only one. I'm in the Encyclopaedia Britannica, right between Ellis Island and Ralph Ellison.
DW: Are you the writer of over 1,000 stories, novellas, screenplays, teleplays and essays?
HE: Yeah, it's probably more like 1,800 now. I find that I have continued to write. I had 10 books last year, and that at my age I think is pretty good. While I always aspired to be Alexandre Dumas, if I reach the level of – I don't know, Donald Westlake – I'll be more than happy.
DW: You must have seen and done as much in speculative fiction as anyone, so can you tell us just what is speculative fiction?
HE: I will give you the only answer that there is. It is the game of "what if?". You take that which is known, and you extrapolate – and you keep it within the bounds of logic, otherwise it becomes fantasy – and you say, "Well, what if?". That's what speculative fiction is, and at its very best, it is classic literature, on a level with Moby Dick and Colette and Edgar Allan Poe.
DW: So it's definitely not fantasy.
HE: Fantasy is a separate genre, and it allows you to go beyond the bounds of that which is acceptable, where all of a sudden people can fly, or the Loch Ness Monster does not have a scientific rationale, but is a mythic creature. It is in the grand tradition of the oldest forms of writing we know, all the way back to Gilgamesh, the very first fiction we know, and the gods. Fantasy is a noble endeavour. Science fiction is a contemporary subset that goes all the way back to Lucian of Samosata, and Verne and Wells, and Aldous Huxley and George Orwell.
DW: It seems to be everywhere, with video games, massive movie franchises and millions of people going to conventions. So why is it so popular now?
HE: Well, we live in a technological age. Time has passed, and we have stepped over the ruins of our own societies, and our own civilisations, and we come now to the fruition of those things about which the human race has dreamed. We have flight and we have electronic assistants. The entertainment media – which are always very timorous and step very carefully out of fear and loathing – don't know what they're doing so much. So they go back, and they are catching up on the kind of science fiction – and they call it, in that ugly, ugly phrase, "sci-fi," which those who have worked in speculative fiction despise, it's like calling a woman a "broad" – they are catching up on ideas that were covered with hoarfrost 60 years ago. That's why you have an overabundance of zombies and walking dead, and world war and asteroids from space. They have not yet tackled any of the truly interesting discussions of humanity that are treated in speculative fiction. But they are a break from standard 19th, early 20th-century fiction, and so they seem fresh to an audience that is essentially ignorant. (...)
DW: In many of your stories there is the oppressor or the bully, who wants to have their way with humanity, with whoever is in the story. The worst of these, I think for me, is I Have No Mouth, and I Must Scream, which is a story of –
HE: Oh, yes, God. God is a shit.
DW: Yeah. It's a story you wrote in a single night. I read it in my teens in a hallucinatory state over the course of a single night. Is there something about – you have to be in this state to find that oppressive being out there? You have to find it in the night?
HE: Well, I wrote another story – I'm not steering away from the question, I'm answering it in an ancillary way, but I'll get right back to it – I wrote a whole book of stories called Deathbird Stories, which are retellings in a modern way of the godlike myths. And one of the short stories that I did, that is in the Best American Short Stories, is called The Man Who Rowed Christopher Columbus Ashore, and it is in a way my atheist tract. I'm a stiff-necked Jewish atheist, and I, like Mark Twain, do not believe that there is a great bearded avuncular spirit up there watching us carefully to see whether we masturbate or not. He's got better things to do creating star systems than to worry about whether we do Feng Shui with the furniture.
When I talk about God, I talk about him not believing in him. If there were a God, and you believed in him, and then instead of saying something ridiculous like, well, God has these mysterious ways, we are not meant to know what it is he's doing, or she's doing, or it's doing, I say, in defiance of Albert Einstein, yes, the universe does shoot craps – God does shoot craps with the universe. One day you'll win £200m in the lottery and the next day you'll get colon cancer. So when I wrote I Have No Mouth, and I Must Scream, I put God in the form of a master computer, AM – cogito ergo sum, I think therefore I am – and had him preserve these half a dozen human beings, after having destroyed the world, to keep them down there and torment them forever, for having created him but giving him no place to go. And I believe – much to the annoyance of my various fervid aficionados – they wish I had more faith.
I say, I have faith in the human spirit, that something noble enough to have created GaudÃ's cathedral in Barcelona is noble enough not to have to go to war over sheep in the Falklands. That's what I Have No Mouth, and I Must Scream says. In fact I did a video game called I Have No Mouth, and I Must Scream, and I created it so you could not win it. The only way in which you could "win" was to play it nobly. The more nobly you played it, the closer to succeeding you would come, but you could not actually beat it. And that annoyed the hell out of people too.
[Laughter]
HE: I spend a lot of time annoying people. That's my job on this planet.
by Damien Walter, The Guardian | Read more:
Photograph: Mark Hanauer/Corbis Outline
Mapping the Driving Forces of Chromosome Structure and Segregation in Escherichia coli
Abstract
The mechanism responsible for the accurate partitioning of newly replicated Escherichia coli chromosomes into daughter cells remains a mystery. In this article, we use automated cell cycle imaging to quantitatively analyse the cell cycle dynamics of the origin of replication (oriC) in hundreds of cells. We exploit the natural stochastic fluctuations of the chromosome structure to map both the spatial and temporal dependence of the motional bias segregating the chromosomes. The observed map is most consistent with force generation by an active mechanism, but one that generates much smaller forces than canonical molecular motors, including those driving eukaryotic chromosome segregation.
Introduction
The fitness of all organisms is dependent on the rapid and faithful replication and segregation of the genome to the daughter cells. Although it has long been appreciated that a mitotic spindle drives chromosome segregation in eukaryotic cells, the dominant mechanism exploited by prokaryotic cells is still debated. Active partitioning systems are known to segregate the low-copy-number plasmids (e.g. P1, R1-16 and F) and homologous systems have been found on the chromosomes of Caulobacter crescentus and Bacillus subtilis and a number of other bacteria (1–7). These active systems are believed to have some functional similarity to spindles but often appear to play a surprisingly limited role: for example, the par genes of B. subtilis are not essential. Intriguingly, no homologous system has yet been discovered in Escherichia coli, and a group of nucleoid structural and segregation genes, including mukBEF, seqA and matP, appear to have supplanted both the bacterial structural maintenance of chromosomes (SMC) and partitioning (par) genes in γ-proteobacteria, suggesting that other mechanisms of segregation may play an important role (8,9).
Much of what is known about the E. coli chromosome segregation mechanism is phenomenological and qualitative: In slow growing cells (generation time ∼120 min), the initial locus dynamics is characterized by a Stay-at-Home phenomena where the locus remains localized to mid-cell (10–16). Replication is initiated at the chromosomal origin of replication (oriC), and proceeds bi-directionally down the two arms of the circular chromosome (Figure 1Α) (17). After roughly 20 min of cohesion (18), newly replicated sister loci split and undergo rapid translocation towards the quarter cell positions (the mid-cell location after division). After reaching the quarter cell positions, oriC dynamics is again characterized by a Stay-at-Home phenomenon (11,15). In general the rest of the chromosome is replicated and segregated continuously and sequentially, such that genes sequentially closer to oriC are replicated and segregated earlier than distant genes (13,18). A number of subtle nucleoid structural transitions have also been reported (T1, T2 and T3), in which loci on the right arm of the chromosome split cooperatively (19,20).
In this article, we perform a quantitative analysis of the motion of oriC, one of the first loci to segregate (16,19). By combining time-lapse epi-fluorescence microscopy with high-throughput automated image analysis, we are able to capture oriC dynamics throughout the cell cycle for greater than an order-of-magnitude more cells than have ever been characterized. This collection of complete cell cycle trajectories facilitates the quantitative analysis of the locus motion summarized qualitatively above. We report the following findings: (i) Mean-Squared Displacement (MSD) analysis of the Rapid-Translocation phase of oriC motion shows sub-diffusive dynamics, rather than processive dynamics. (ii) Similar dynamics are observed for the actively partitioned plasmid R1-16 by MSD analysis, demonstrating that processive dynamics on times scales shorter than a cell cycle are not a prerequisite for active segregation mechanisms. (iii) A comparison of the step-size distribution between the Rapid-Translocation and Stay-at-Home phases of locus motion shows a distribution-wide bias towards the eventual destination, rather than the presence of large biased steps. (iv) Faithful segregation of the origin loci results from a small diffusional bias, a drift velocity, that switches from a restoring force, centred around mid-cell before locus segregation, to a restoring force centred around the quarter cell positions immediately proceeding locus splitting. The cell appears to identify the quarter cell positions in advance of the arrival of oriC suggesting the existence of a cellular landmark determining this position. Because the nucleoid is significantly remodelled during this period while the drift velocity remains qualitatively unchanged, it is unlikely that nucleoid structure (19,20) or chromosome entropy (21) is the dominant source of the diffusional bias and therefore suggests the existence of an additional as-yet undiscovered segregation mechanism in E. coli. The measurement of the drift velocity and the interpretation of this velocity in terms of a driving force provide the first clear biophysical picture of the dynamical changes that drive the segregation process and reconcile the seemingly conflicting observations of sub-diffusive MSD scaling and active segregation. We expect this analysis to be applicable not only to the interpretation of other chromosome dynamics problems, but also to sub-cellular stochastic motion in general.
The mechanism responsible for the accurate partitioning of newly replicated Escherichia coli chromosomes into daughter cells remains a mystery. In this article, we use automated cell cycle imaging to quantitatively analyse the cell cycle dynamics of the origin of replication (oriC) in hundreds of cells. We exploit the natural stochastic fluctuations of the chromosome structure to map both the spatial and temporal dependence of the motional bias segregating the chromosomes. The observed map is most consistent with force generation by an active mechanism, but one that generates much smaller forces than canonical molecular motors, including those driving eukaryotic chromosome segregation.
IntroductionThe fitness of all organisms is dependent on the rapid and faithful replication and segregation of the genome to the daughter cells. Although it has long been appreciated that a mitotic spindle drives chromosome segregation in eukaryotic cells, the dominant mechanism exploited by prokaryotic cells is still debated. Active partitioning systems are known to segregate the low-copy-number plasmids (e.g. P1, R1-16 and F) and homologous systems have been found on the chromosomes of Caulobacter crescentus and Bacillus subtilis and a number of other bacteria (1–7). These active systems are believed to have some functional similarity to spindles but often appear to play a surprisingly limited role: for example, the par genes of B. subtilis are not essential. Intriguingly, no homologous system has yet been discovered in Escherichia coli, and a group of nucleoid structural and segregation genes, including mukBEF, seqA and matP, appear to have supplanted both the bacterial structural maintenance of chromosomes (SMC) and partitioning (par) genes in γ-proteobacteria, suggesting that other mechanisms of segregation may play an important role (8,9).
Much of what is known about the E. coli chromosome segregation mechanism is phenomenological and qualitative: In slow growing cells (generation time ∼120 min), the initial locus dynamics is characterized by a Stay-at-Home phenomena where the locus remains localized to mid-cell (10–16). Replication is initiated at the chromosomal origin of replication (oriC), and proceeds bi-directionally down the two arms of the circular chromosome (Figure 1Α) (17). After roughly 20 min of cohesion (18), newly replicated sister loci split and undergo rapid translocation towards the quarter cell positions (the mid-cell location after division). After reaching the quarter cell positions, oriC dynamics is again characterized by a Stay-at-Home phenomenon (11,15). In general the rest of the chromosome is replicated and segregated continuously and sequentially, such that genes sequentially closer to oriC are replicated and segregated earlier than distant genes (13,18). A number of subtle nucleoid structural transitions have also been reported (T1, T2 and T3), in which loci on the right arm of the chromosome split cooperatively (19,20).
In this article, we perform a quantitative analysis of the motion of oriC, one of the first loci to segregate (16,19). By combining time-lapse epi-fluorescence microscopy with high-throughput automated image analysis, we are able to capture oriC dynamics throughout the cell cycle for greater than an order-of-magnitude more cells than have ever been characterized. This collection of complete cell cycle trajectories facilitates the quantitative analysis of the locus motion summarized qualitatively above. We report the following findings: (i) Mean-Squared Displacement (MSD) analysis of the Rapid-Translocation phase of oriC motion shows sub-diffusive dynamics, rather than processive dynamics. (ii) Similar dynamics are observed for the actively partitioned plasmid R1-16 by MSD analysis, demonstrating that processive dynamics on times scales shorter than a cell cycle are not a prerequisite for active segregation mechanisms. (iii) A comparison of the step-size distribution between the Rapid-Translocation and Stay-at-Home phases of locus motion shows a distribution-wide bias towards the eventual destination, rather than the presence of large biased steps. (iv) Faithful segregation of the origin loci results from a small diffusional bias, a drift velocity, that switches from a restoring force, centred around mid-cell before locus segregation, to a restoring force centred around the quarter cell positions immediately proceeding locus splitting. The cell appears to identify the quarter cell positions in advance of the arrival of oriC suggesting the existence of a cellular landmark determining this position. Because the nucleoid is significantly remodelled during this period while the drift velocity remains qualitatively unchanged, it is unlikely that nucleoid structure (19,20) or chromosome entropy (21) is the dominant source of the diffusional bias and therefore suggests the existence of an additional as-yet undiscovered segregation mechanism in E. coli. The measurement of the drift velocity and the interpretation of this velocity in terms of a driving force provide the first clear biophysical picture of the dynamical changes that drive the segregation process and reconcile the seemingly conflicting observations of sub-diffusive MSD scaling and active segregation. We expect this analysis to be applicable not only to the interpretation of other chromosome dynamics problems, but also to sub-cellular stochastic motion in general.
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