Friday, May 4, 2012
A New Wind Energy Concept
Apparently only at the concept stage now, but one advantage over wind turbines is that it eliminated the rotating blades, with their consequent noise and risk to birds:
New York design firm Atelier DNA has an alternative concept that ditches blades in favor of stalks. Resembling thin cattails, the Windstalks generate electricity when the wind sets them waving...Further details at Discovery News.
The proposed design calls for 1,203 "“stalks," each 180-feet high with concrete bases that are between about 33- and 66-feet wide. The carbon-fiber stalks, reinforced with resin, are about a foot wide at the base tapering to about 2 inches at the top. Each stalk will contain alternating layers of electrodes and ceramic discs made from piezoelectric material, which generates a current when put under pressure. In the case of the stalks, the discs will compress as they sway in the wind, creating a charge.
h/t via: TYWKIWDBI
Outgrowing Oneself
A certain strain of neoclassical economics holds that subjective individual preferences have no ultimate analytical significance. This is the ideological upshot of a laissez-faire attitude toward taste: All tastes are just residual, a revealed preference for x over y, and the difference between x and y is immaterial, a local phenomenon beneath study. It has the illusion of significance to the individual, but from the Olympian perspective required to grapple with human socioeconomic behavior, it’s just noise.
One of the tragedies of getting old is seeing this perspective confirmed in the indifferent destinies of commodities that were once far more than mere commodities to you. Distinctions that seemed crucial, epochal, even existential, are slowly eroded until you are forced to admit to yourself that maybe they never existed at all. Or at best, the distinctions were not ontological, not in the intrinsic nature of the things you cared about, but were instead historically contingent. Which in turn means your sense of self, the differences that were so salient and so definitive of how you thought of yourself, were also contingent, historical artifacts.
Anyway, I was prompted to these bathetic thoughts this morning by reading Philip Mirowski’s Machine Dreams while having breakfast at a diner counter near a radio blasting a classic rock station. “Dance the Night Away” by Van Halen was playing, and next came “Mysterious Ways” by U2. The transition was seamless and unremarkable, only I can remember when I was in high school, when listening to U2 and not Van Halen was of intense social importance, when the difference was glaring, and it dictated how one wanted to perceived and whom one felt comfortable hanging around with. It seems incredibly silly now, but growing up in semi-rural, semi-suburban Upper Bucks County, the discontinuity between Van Halen and U2 created a space in which to exist, and a hope that one might turn out to be something other than what the suburban environment seemed to promise. You could listen to something like the Beastie Boys and think your friends were the only other people who got it — them and maybe some idealized people out there who also would have been your friends if you weren’t so isolated. The special few who would redeem the future.
But of course, that nascent sense of personal uniqueness and destined escape was wholly internal to the suburban experience; it was part of the program, an essential component of what detached houses and cars and the rest of it inculcated. With its veneer of conformity, suburbia imparts a sense of aggrieved, threatened individuality, but more important, it gives its children a constitutive myopia about it, making it impossible for them to see that the ambitious discontentedness, the certitude that one is far more special than the mediocrity of shopping malls and chain restaurants and the rest, is part of the code for reproducing the suburbs, not a disruptive mutation. In short, it would be weird if you didn’t feel alienated. Radical alienation is the first step toward cynicism and pliancy. You meet people at a high school reunion and discover that actually you all hated the same thing back then — yourself. It just got expressed in different ways: listening to Van Halen, listening to U2.
One of the first and more memorable moments that I had a premonition of what being old would be like was when I came back to college in January 1992 after a holiday break. I was at a party and the customary Steve Miller Band songs were blasting, and then suddenly, with no fuss, Nirvana was playing. I felt instantly as if I had been completely exposed. I thought there was something special about being into a certain kind of music — and Nirvana in the summer of 1991 was very much that music. It was supposed to be a bulwark against being perceived as mediocre. Suddenly I saw that the distinctions I was investing myself in were always already unimaginative, insignificant — superficial distractions that had preoccupied me and protected me from pursuing some other kind of self-knowledge. The future didn’t promise escape but re-enclosure and surrender. The escape routes you learned were already traced on commercial maps. They led deeper into enemy territory. You wake up to discover that you are in fact enlisted in the enemy’s army.
Moreover, at that moment “Smells Like Teen Spirit” was playing, I saw instantly that the distinctions that made me in my mind who I was didn’t really belong to me, and they could be wiped away in an instant, by some frat bro playing a certain CD on his boombox. I realized I didn’t even know what could belong to me, in that sense. I had an intimation of that bitter-old-man insight that there is in fact no distinction to be found in consuming and projecting allegiance to those sorts of commercial products. I was lifted up for a moment to the bleak promontory from which I could see that all those cultural commodities are basically the same. It was terrifying, because from that perch one can see the higher one, from which all “individuals” are essentially the same mortal creatures, preoccupied with distinctions that are indistinguishable from the perspective of eternity. And now a Beastie Boy is dead.
by Rob Horning, Marginal Utility | The New Inquiry
Restaurant Moneyball
In one month, Timothy (not his real name) served 426 customers, pulling in $17,991.50 in gross sales with a per-check average of $42.23. That’s $3.84 below the overall per-check average at the Landmarc. It turns out that while Timothy was beating the rest of the waitstaff in add-on sales like bacon or cheese on a burger, he was lagging 2 percent behind everybody else in red wine and liquor sales, and a whopping 14 percent behind his peers in sides like French fries and creamed spinach.
The bottom line was $1,636 of lost sales opportunity in a month — the money Timothy would have made if he’d hit the server average.
We know all this because every item sold at Landmarc — down to the last malbec, martini and red quinoa pilaf — is individually logged and enumerated by a sophisticated software package called Slingshot. The software slices, dices and crunches the data every night, and then serves it to managers with breakfast the next morning.
So when Timothy was up for a performance review last summer, the restaurant’s general manager knew everything about him — information she incorporated into a heart-to-heart talk about improving his average.
Some of the nation’s top eateries are quietly embracing data mining to eke out profit in a tough economy.
“It used to be that a manager would say, ‘That server’s great! He’s a nice guy, he shows up on time and keeps the salt shakers full,’” says Damian Mogavero, the entrepreneur behind Slingshot. “Now they can tell a server, ‘You sell 40 percent less red wine than your peers and you work in a steakhouse!’”
Welcome to the data-driven, number-crunching future of restauranteering. With the food business thriving again in the midst of America’s economic upswing – consistently claiming a whopping 4 percent of GDP — some of the nation’s top eateries are quietly embracing data mining to eke out profit in a tough economy. Software systems like Compeat, Hotschedules and Eatec help restaurants track complex metrics like sales trends, employee overtime, and food orders from suppliers.
by Joe Ray, Wired | Read more:
Image via:
The Four Noble Truths
The Four Noble Truths:
1. Life means suffering.
- To live means to suffer, because the human nature is not perfect and neither is the world we live in. During our lifetime, we inevitably have to endure physical suffering such as pain, sickness, injury, tiredness, old age, and eventually death; and we have to endure psychological suffering like sadness, fear, frustration, disappointment, and depression. Although there are different degrees of suffering and there are also positive experiences in life that we perceive as the opposite of suffering, such as ease, comfort and happiness, life in its totality is imperfect and incomplete, because our world is subject to impermanence. This means we are never able to keep permanently what we strive for, and just as happy moments pass by, we ourselves and our loved ones will pass away one day, too.
2. The origin of suffering is attachment.
- The origin of suffering is attachment to transient things and the ignorance thereof. Transient things do not only include the physical objects that surround us, but also ideas, and -in a greater sense- all objects of our perception. Ignorance is the lack of understanding of how our mind is attached to impermanent things. The reasons for suffering are desire, passion, ardour, pursuit of wealth and prestige, striving for fame and popularity, or in short: craving and clinging. Because the objects of our attachment are transient, their loss is inevitable, thus suffering will necessarily follow. Objects of attachment also include the idea of a “self” which is a delusion, because there is no abiding self. What we call “self” is just an imagined entity, and we are merely a part of the ceaseless becoming of the universe.
3. The cessation of suffering is attainable.
- The cessation of suffering can be attained through nirodha. Nirodha means the unmaking of sensual craving and conceptual attachment. The third noble truth expresses the idea that suffering can be ended by attaining dispassion. Nirodha extinguishes all forms of clinging and attachment. This means that suffering can be overcome through human activity, simply by removing the cause of suffering. Attaining and perfecting dispassion is a process of many levels that ultimately results in the state of Nirvana. Nirvana means freedom from all worries, troubles, complexes, fabrications and ideas. Nirvana is not comprehensible for those who have not attained it.
4. The path to the cessation of suffering.
- There is a path to the end of suffering - a gradual path of self-improvement, which is described more detailed in the Eightfold Path. It is the middle way between the two extremes of excessive self-indulgence (hedonism) and excessive self-mortification (asceticism); and it leads to the end of the cycle of rebirth. The latter quality discerns it from other paths which are merely “wandering on the wheel of becoming”, because these do not have a final object. The path to the end of suffering can extend over many lifetimes, throughout which every individual rebirth is subject to karmic conditioning. Craving, ignorance, delusions, and its effects will disappear gradually, as progress is made on the path.
Image: Tea (Housen-in temple, Kyoto) (by Marser)
Thursday, May 3, 2012
Japan Shrinks
Many nations have aging populations, but none can quite match Japan. Its experience holds lessons for other countries as well as insights into the distinctiveness of Japanese society.
In 2006, Japan reached a demographic and social turning point. According to Tokyo’s official statistics, deaths that year very slightly outnumbered births. Nothing like this had been recorded since 1945, the year of Japan’s catastrophic defeat in World War II. But 2006 was not a curious perturbation. Rather, it was the harbinger of a new national norm.
Japan is now a “net mortality society.” Death rates today are routinely higher than birthrates, and the imbalance is growing. The nation is set to commence a prolonged period of depopulation. Within just a few decades, the number of people living in Japan will likely decline 20 percent. The Germans, who saw their numbers drop by an estimated 700,000 in just the years from 2002 to 2009, have a term for this new phenomenon: schrumpfende Gesellschaft, or “shrinking society.” Implicit in the phrase is the understanding that a progressive peacetime depopulation will entail much more than a lowered head count. It will inescapably mean a transformation of family life, social relationships, hopes and expectations—and much more.
But Japan is on the cusp of an even more radical demographic makeover than the one now under way in Germany and other countries that are in a similar situation, including Italy, Hungary, and Croatia. (The United States is also aging, but its population is still growing.) Within barely a generation, demographic trends promise to turn Japan into a dramatically—in some ways almost unimaginably—different place from the country we know today. If we go by U.S. Census Bureau projections for Japan, for example, there will be so many people over 100 years of age in 2040, and so few babies, that there could almost be one centenarian on hand to welcome each Japanese newborn. Population decline and extreme population aging will profoundly alter the realm of the possible for Japan—and will have major reverberations for the nation’s social life, economic performance, and foreign relations. Gradually but relentlessly, Japan is evolving into a type of society whose contours and workings have only been contemplated in science fiction. It is not clear that Japan’s path will be a harbinger of what lies ahead in other aging societies. Over the past century, modernization has markedly increased the economic, educational, technological, and social similarities between Japan and other affluent countries. However, Japan has remained distinctive in important respects—and in the years ahead it may become increasingly unlike other rich countries, as population change accentuates some of its all-but-unique attitudes and proclivities.
Hiroshige, Ashida. via:
Disruptions: With No Revenue, an Illusion of Value
The gears of Silicon Valley continue to mesh and turn because of money, not necessarily technological innovations. And there are certain things about that money machine that denizens of the Valley would rather keep quiet.
First, they’ll never acknowledge the possibility of a bubble. “Bubble? Ha!” venture capitalists often tell me. “Silly reporter, there is no bubble.”
O.K., I get this spin. It makes sense from an investor’s point of view. Acknowledging any possibility that tech companies aren’t worth what you say they are worth would be followed by the sound of a giant pop, and the money and investments would dry up. The machine could grind to a halt.
Yet an even more bizarre activity in the Valley than shushing the talk of a bubble is how some start-ups are advised by investors not to make money. This concept may sound ridiculous from a business standpoint, but for investors, it fuels the get-richer-quicker mentality that exists here.
“It serves the interest of the investors who can come up with whatever valuation they want when there are no revenues,” explained Paul Kedrosky, a venture investor and entrepreneur. “Once there is no revenue, there is no science, and it all just becomes finger in the wind valuations.”
When small start-ups I’ve spoken with do make money, they often find it difficult to recruit additional investment because most venture capitalists — and often the entrepreneurs they finance — are not interested in building viable long-term businesses. Rather, they’re interested in pumping up enough hype and valuation to find a quick exit through an acquisition at an eye-popping premium.
Getting acquired while producing no revenue is like performing a card trick without the deck of cards: the magician simply explains how magical the trick is, never actually showing it. (And we are supposed to step back in sheer awe.)
by Nick Bilton, NY Times | Read more:
Photo: Richard Perry/The New York Times
©Jean-Philippe Charbonnier Courtesy RTR Galerie
via:
Becoming Obama
When Barack Obama met Genevieve Cook in 1983 at a Christmas party in New York’s East Village, it was the start of his most serious romance yet. But as the 22-year-old Columbia grad began to shape his future, he was also struggling with his identity: American or international? Black or white? Drawing on conversations with both Cook and the president, David Maraniss, in an adaptation from his new Obama biography, has the untold story of the couple’s time together.
Barack Obama transferred from Occidental College to Columbia University in 1981, his junior year. Although he left Los Angeles with enough ambitious propulsion to carry him into a more active period, he instead receded into the most existentialist stretch of his life. As he put it himself decades later during an interview in the Oval Office, “I was leading a very ascetic existence, way too serious for my own good.” In most outward ways, compared with what had come before, his life in New York was a minimalist one, without the sprawling cast of characters that had surrounded him at Oxy and in Hawaii and Indonesia. He felt no attachment to Columbia or to the first jobs he landed after graduation. But it would be a misreading to say that he was tamping down his ambitions during that period. Just the opposite, in fact. If anything, his sense of destiny deepened. He was conducting an intense debate with himself over his past, present, and future, an internal struggle that he shared with only a few close friends, including his girlfriends, Alex McNear and Genevieve Cook, who kept a lasting record, one in letters, the other in her journal.
“Where Am I Going?”
It is exponentially easier to look back at a life than to live it forward. In retrospect it becomes apparent that New York was crucial to Obama. If he had not quite found his place yet, he was learning in which directions not to go and how to avoid turns that would lead him off the path and into traps from which it would be hard to escape. Even when he was uncertain about much else, Obama seemed hyper-alert to avoiding a future he did not want.
At age 20, Obama was a man of the world. He had never been to south-central Kansas or western Kenya, the homelands of his ancestors, yet his divided heritage from Africa and the American heartland had defined him from the beginning. He could not be of one place, rooted and provincial. From his years living in Indonesia, where he was fully immersed in Javanese schools and culture; from his adolescence in Hawaii, where he was in the polyglot sea of hapa and haole, Asians and islanders; from his mother’s long-term commitment to development work overseas; from his friendship with Pakistani students at Occidental and his extended visit to their country—from all of these he had experienced far more global diversity than the average college junior. He knew the ways of different cultures better than he knew himself.
by David Maraniss, Vanity Fair | Read more:
Photo: From A.P. Images/Obama Presidential Campaign.
Leaving Wall Street
When some people think about Wall Street, they conjure up images of traders shouting on the stock exchange, of bankers dining at five star restaurants, of CEOs whispering in the ears of captured Congress members.
When I think about Wall Street, I think about its stunted rainbow of pale pastel shirts. I think about the vaulting, highly secured, and very cold lobbies. And I think about the art passed daily by the harried workers, virtually unseen.
Before I occupied Wall Street, Wall Street occupied me. What started as a summer internship led to a seven-year career. During my time on Wall Street, I changed from a curious college student full of hope for my future, into a cynical, bitter, depressed, and exhausted “knowledge worker” who felt that everyone was out to screw me over.
The culture of Wall Street is pervasive and contagious. While there are Wall Street employees who are able to ignore it, or block it out, I was not one of them. I drank the Kool Aid. I’m out of it now. But I’d like to tell you what it was like.
When you are wealthy and successful, you have a choice. You can believe your success stems from luck and privilege, or you can believe it stems from hard work. Very few people like to view their success as a matter of luck. And so, perhaps understandably, most people on Wall Street believe they have earned their jobs, and the money that follows.
While there are many on Wall Street who come from wealthy backgrounds, there are also many people from very humble backgrounds. In my experience, it is often those who do not come from privilege who are the system’s fiercest defenders.
When I was a summer intern, we met with various executives who’d tell us about their careers and pitch us on the firm. The aim was to sell the firm to everyone, even though only a few of us would ultimately be offered full-time positions at the firm. It had an element of redundancy to it, since we were clearly already interested in the firm, or we wouldn’t be there at all. The effect of these talks, then, was to make a competitive situation even more competitive. Welcome to Wall Street. One executive described the firm as a “Golden Springboard.” If we began our careers there, his reasoning went, there wasn’t anywhere we couldn’t go. The executive was right. Background becomes irrelevant once you have “made it” to Wall Street. Once you’ve gotten in the door, you’re one of “us.”
by Alexis Goldstein, N+1 Magazine | Read more:
Image: Wall Street, 1915. Paul Strand.
Wednesday, May 2, 2012
Bear Meat
Evenings spent in a mountain hut are among the most sublime and intense that life holds. I mean a real hut, the kind where you seek shelter after a four-, five-, or six-hour climb and where you find few so-called comforts.
Not that chairlifts and cable cars and such comforts are to be looked down on: they are, on the contrary, logical achievements of our society, which is what it is, and must be either accepted or rejected in its totality—and those who are able to reject it are few. But the advent of the chairlift puts an end to a valuable process of natural selection, by which those who reach the hut are sure to find, in its pure state, a small sample of a little-known human subspecies.
Its members are people who don’t speak much and of whom others don’t speak at all, so there is no mention of them in the literature of most countries, and they should not be confused with other, vaguely similar types, who do speak, and of whom others speak: hot shots, extreme climbers, members of famous international expeditions, professionals, etc. All worthy people, but this story is not about them.
I arrived at the hut at sunset, and I was very tired. I stayed outside, on the wooden porch, to consider the frozen mystery of the seracs at my feet until everything had vanished behind silent ghosts of fog, and then I went in.
Inside it was almost dark. By the glow of a small carbide lamp one could distinguish a dozen human figures gathered around three or four tables. I sat down at a table and opened my backpack. Across from me was a tall, large man, middle-aged, with whom I exchanged a few words about the weather and our plans for the following day. This is a standard conversation, like the classic opening moves of a chess game, where what matters, much more than what one says (which is brief and obvious), is the tone in which one says it.
We found ourselves in agreement on the fact that the weather was uncertain (it always is in the mountains; when it isn’t, it is nonetheless declared to be so, for obvious magical reasons), and on the forecast for the following day. A little later, two lanky men in their twenties entered, with long beards and ravenous eyes. They had arrived from another valley and were attempting an intricate series of crossings. They sat down at our table.
After we had eaten, we started to drink. Wine is a more complex substance than one might think, and, above two thousand metres, and at close to zero degrees centigrade, it displays interesting behavioral anomalies. It changes flavor, loses the bite of alcohol, and regains the mildness of the grape from which it comes. One can take it in heavy doses without any undesired effects. In fact, it eliminates fatigue, loosens and warms the limbs, and leads to a fanciful mood. It is no longer a luxury or a vice but a metabolic necessity, like water on the plains. It is a well-known fact that vines grow better on a slope: could there be a connection?
Once we started drinking, the conversation at our table became much less impersonal. Each of us spoke of our initiation, and we established with some surprise that we had all begun our mountaineering careers with an extremely foolish act.
As it turned out, the best of these foolish acts, and the best told, was the one recounted by the tall, large man.
by Primo Levi, New Yorker | Read more:
Photo: The Alaska List
Not that chairlifts and cable cars and such comforts are to be looked down on: they are, on the contrary, logical achievements of our society, which is what it is, and must be either accepted or rejected in its totality—and those who are able to reject it are few. But the advent of the chairlift puts an end to a valuable process of natural selection, by which those who reach the hut are sure to find, in its pure state, a small sample of a little-known human subspecies. Its members are people who don’t speak much and of whom others don’t speak at all, so there is no mention of them in the literature of most countries, and they should not be confused with other, vaguely similar types, who do speak, and of whom others speak: hot shots, extreme climbers, members of famous international expeditions, professionals, etc. All worthy people, but this story is not about them.
I arrived at the hut at sunset, and I was very tired. I stayed outside, on the wooden porch, to consider the frozen mystery of the seracs at my feet until everything had vanished behind silent ghosts of fog, and then I went in.
Inside it was almost dark. By the glow of a small carbide lamp one could distinguish a dozen human figures gathered around three or four tables. I sat down at a table and opened my backpack. Across from me was a tall, large man, middle-aged, with whom I exchanged a few words about the weather and our plans for the following day. This is a standard conversation, like the classic opening moves of a chess game, where what matters, much more than what one says (which is brief and obvious), is the tone in which one says it.
We found ourselves in agreement on the fact that the weather was uncertain (it always is in the mountains; when it isn’t, it is nonetheless declared to be so, for obvious magical reasons), and on the forecast for the following day. A little later, two lanky men in their twenties entered, with long beards and ravenous eyes. They had arrived from another valley and were attempting an intricate series of crossings. They sat down at our table.
After we had eaten, we started to drink. Wine is a more complex substance than one might think, and, above two thousand metres, and at close to zero degrees centigrade, it displays interesting behavioral anomalies. It changes flavor, loses the bite of alcohol, and regains the mildness of the grape from which it comes. One can take it in heavy doses without any undesired effects. In fact, it eliminates fatigue, loosens and warms the limbs, and leads to a fanciful mood. It is no longer a luxury or a vice but a metabolic necessity, like water on the plains. It is a well-known fact that vines grow better on a slope: could there be a connection?
Once we started drinking, the conversation at our table became much less impersonal. Each of us spoke of our initiation, and we established with some surprise that we had all begun our mountaineering careers with an extremely foolish act.
As it turned out, the best of these foolish acts, and the best told, was the one recounted by the tall, large man.
by Primo Levi, New Yorker | Read more:
Photo: The Alaska List
One Drug to Shrink All Tumors
A single drug can shrink or cure human breast, ovary, colon, bladder, brain, liver, and prostate tumors that have been transplanted into mice, researchers have found. The treatment, an antibody that blocks a "do not eat" signal normally displayed on tumor cells, coaxes the immune system to destroy the cancer cells.
A decade ago, biologist Irving Weissman of the Stanford University School of Medicine in Palo Alto, California, discovered that leukemia cells produce higher levels of a protein called CD47 than do healthy cells. CD47, he and other scientists found, is also displayed on healthy blood cells; it's a marker that blocks the immune system from destroying them as they circulate. Cancers take advantage of this flag to trick the immune system into ignoring them. In the past few years, Weissman's lab showed that blocking CD47 with an antibody cured some cases of lymphomas and leukemias in mice by stimulating the immune system to recognize the cancer cells as invaders. Now, he and colleagues have shown that the CD47-blocking antibody may have a far wider impact than just blood cancers.
"What we've shown is that CD47 isn't just important on leukemias and lymphomas," says Weissman. "It's on every single human primary tumor that we tested." Moreover, Weissman's lab found that cancer cells always had higher levels of CD47 than did healthy cells. How much CD47 a tumor made could predict the survival odds of a patient.
To determine whether blocking CD47 was beneficial, the scientists exposed tumor cells to macrophages, a type of immune cell, and anti-CD47 molecules in petri dishes. Without the drug, the macrophages ignored the cancerous cells. But when the CD47 was present, the macrophages engulfed and destroyed cancer cells from all tumor types.
Next, the team transplanted human tumors into the feet of mice, where tumors can be easily monitored. When they treated the rodents with anti-CD47, the tumors shrank and did not spread to the rest of the body. In mice given human bladder cancer tumors, for example, 10 of 10 untreated mice had cancer that spread to their lymph nodes. Only one of 10 mice treated with anti-CD47 had a lymph node with signs of cancer. Moreover, the implanted tumor often got smaller after treatment -- colon cancers transplanted into the mice shrank to less than one-third of their original size, on average. And in five mice with breast cancer tumors, anti-CD47 eliminated all signs of the cancer cells, and the animals remained cancer-free 4 months after the treatment stopped.
"We showed that even after the tumor has taken hold, the antibody can either cure the tumor or slow its growth and prevent metastasis," says Weissman.
by Sarah C.P. Williams, Science | Read more:
Photo: Fotosearch
A decade ago, biologist Irving Weissman of the Stanford University School of Medicine in Palo Alto, California, discovered that leukemia cells produce higher levels of a protein called CD47 than do healthy cells. CD47, he and other scientists found, is also displayed on healthy blood cells; it's a marker that blocks the immune system from destroying them as they circulate. Cancers take advantage of this flag to trick the immune system into ignoring them. In the past few years, Weissman's lab showed that blocking CD47 with an antibody cured some cases of lymphomas and leukemias in mice by stimulating the immune system to recognize the cancer cells as invaders. Now, he and colleagues have shown that the CD47-blocking antibody may have a far wider impact than just blood cancers. "What we've shown is that CD47 isn't just important on leukemias and lymphomas," says Weissman. "It's on every single human primary tumor that we tested." Moreover, Weissman's lab found that cancer cells always had higher levels of CD47 than did healthy cells. How much CD47 a tumor made could predict the survival odds of a patient.
To determine whether blocking CD47 was beneficial, the scientists exposed tumor cells to macrophages, a type of immune cell, and anti-CD47 molecules in petri dishes. Without the drug, the macrophages ignored the cancerous cells. But when the CD47 was present, the macrophages engulfed and destroyed cancer cells from all tumor types.
Next, the team transplanted human tumors into the feet of mice, where tumors can be easily monitored. When they treated the rodents with anti-CD47, the tumors shrank and did not spread to the rest of the body. In mice given human bladder cancer tumors, for example, 10 of 10 untreated mice had cancer that spread to their lymph nodes. Only one of 10 mice treated with anti-CD47 had a lymph node with signs of cancer. Moreover, the implanted tumor often got smaller after treatment -- colon cancers transplanted into the mice shrank to less than one-third of their original size, on average. And in five mice with breast cancer tumors, anti-CD47 eliminated all signs of the cancer cells, and the animals remained cancer-free 4 months after the treatment stopped.
"We showed that even after the tumor has taken hold, the antibody can either cure the tumor or slow its growth and prevent metastasis," says Weissman.
by Sarah C.P. Williams, Science | Read more:
Photo: Fotosearch
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