Sunday 29 June 2008

WISDOM-Every man is guilty of all the good he didn't do.

Complaining is silly. Either act or forget.
Thinking life will be better in the future is stupid. I have to live now.
Being not truthful works against me.
Helping other people helps me.
Organizing a charity group is surprisingly easy.
Everything I do always comes back to me.
Drugs feel great in the beginning and become a drag later on.
Over time I get used to everything and start taking it for granted.
Money does not make me happy.
Traveling alone is helpful for a new perspective on life.
Assuming is stifling.
Keeping a diary supports my personal development.
Trying to look good limits my life.
Worrying solves nothing.
Material luxuries are best enjoyed in small doses.
Having guts always works out for me.


//////////////////=http://taitology.com/2008/01/13/things-i-have-learned-in-my-life-so-far/

////////////////////Primordial Stars Frozen Indefinitely by Dark Matter
It is thought that primordial or "Population III" stars were born in dense clouds of dark matter, 100 million years after the Big Bang. During the period between birth and dark matter depletion, these first stars were effectively but into a "deep freeze" where normal star development was prevented. After this period when all the dark matter fuel had been consumed, these stars were allowed to commence normal stellar evolution, dying out within a few hundred thousand years. But say if a Population III star was born in an exceptionally dense cloud of dark matter? How long could "normal stellar evolution" be frozen for? According to new research, dark matter could theoretically freeze the star indefinitely, over timescales longer than the age of the Universe…


/////////////////SB=Oxytocin
Posted: 24 Jun 2008 10:47 AM CDT
I was on the Takeaway last week talking about this study:
We examined the role of serotonin transporter (5-HTT) and oxytocin receptor (OXTR) genes in explaining differences in sensitive parenting in a community sample of 159 Caucasian, middle-class mothers with their 2-year-old toddlers at risk for externalizing behavior problems, taking into account maternal educational level, maternal depression and the quality of the marital relationship. Independent genetic effects of 5-HTTLPR SCL6A4 and OXTR rs53576 on observed maternal sensitivity were found. Controlling for differences in maternal education, depression and marital discord, parents with the possibly less efficient variants of the serotonergic (5-HTT ss) and oxytonergic (AA/AG) system genes showed lower levels of sensitive responsiveness to their toddlers. Two-way and three-way interactions with marital discord or depression were not significant. This first study on the role of both OXTR and 5-HTT genes in human parenting points to molecular genetic differences that may be implicated in the production of oxytocin explaining differences in sensitive parenting.
It's certainly interesting work, and builds on a large body of data showing that perfusing the brain with oxytocin (often via a nasal spray) leads to more generous offers in the ultimatum game, causes prairie voles to instantly pair bond and can, in general, serve as a social lubricant. (In other words, it's like alcohol without the drunkenness.) This new study found an intriguing correlation between mothers with a less efficient serotonin transporter gene (which modulates the release of oxytocin) and various measures of maternal nurturing, such as the number of times a baby is cuddled. For me, the most interesting aspect of such research is how it demonstrates the sheer difficulty of breaking such damaging social cycles. Let's say, for instance, that mothers with these genetic variants really are less responsive and sensitive to their children. Other research suggests that infants suffering from childhood neglect suffer from reduced oxytocin and vasopressin levels later on in childhood. The absence of love leaves a biological scar, which is then inflicted on the next generation and so on.
This depressing hypothesis is backed up some even more depressing primate research. As Harry Harlow demonstrated decades ago, baby monkeys forced to live with an unresponsive wire mother didn't know how to deal with others, sympathize with strangers or behave in a socially acceptable manner. They would start fights without provocation and they wouldn't stop fighting until one of the monkeys had been seriously injured. They were even vicious to their own children. One monkey raised by a wire-mother bit off the fingers of her child. Another killed her crying baby by crushing its head in her mouth. Most of these scarred mothers, however, just perpetuated the devastating cycle of cruelty. When their babies tried to cuddle, they would push them away. As Harlow would later write, "If monkeys have taught us anything it's that you've got to learn how to love before you learn how to live."
That said, oxytocin hype is getting out of control. (Just today, Drudge linked to a lame article on how oxytocin can "cure" shyness. So can a six-pack.) It's become the neurotransmitter-of-the-month, the occult chemical that can make you more moral, romantic and outgoing. By the way, it's also a potential cure for autism. While there's been some really interesting research on oxytocin - I'm particularly enamored of the ultimatum game stuff - I think we're in danger of falling into what I'll call the serotonin trap. Remember when serotonin was the secret of happiness, the little molecule that, when elevated by an SSRI, could cure depression and make even healthy individuals happier? Well, that nea


//////////////////GE=Selection, drift, disease and complexity, all rolled into one....
Posted: 24 Jun 2008 02:59 PM CDT
One of the great things about evolutionary genetics is that it is such a diverse field in terms of the cognitive toolkit which one must access as a matter of course. Since R. A. Fisher's The Genetical Theory of Natural Selection (along with the contemporaneous work of Sewall Wright and J. B. S. Haldane) we've been habituated toward thinking of evolutionary processes on an abstract level which might allow us to make general deductive inferences from first principles. Genetic drift, selection, migration, etc., are parameters which are used to construct models that allow us to generate predictions and obtain deeper insight. The discovery of DNA and the elucidation of the biophysical substrate which constrains the modes of inheritance in a concrete manner opened up the startling vistas of molecular evolutionary genetics. This discipline has allowed an inspection of how the predictions of evolutionary theory are born out on a more fine grained level. And today the genomics revolution is ramping up the data sets as computational power enables more powerful extraction of the patterns and dynamics which emerge out of these discrete streams of information.
But this is all rather philosophical and abstract. Yesterday I posted on a paper which showed how selection and drift might have operated upon the frequency of an allele which has a disease implication, and so has a pragmatic impact on quality of life. Today I'd like to bring your attention to another paper which synthesizes the big picture ideas which might entail consequences in terms of the utilitarian details of daily life, Natural Selection on Genes that Underlie Human Disease Susceptibility:Read the rest of this post... Read the comments on this post...


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CDS 2906082208-BECONSCOT MODEL VILLAGE VISITED


///////////////SPAIN WINS EURO FOOTBALL CUP AFTER 1964



///////////////SW=Silence of the Bees
Posted: 25 Jun 2008 07:33 AM CDT
You may have heard that honeybees in this country are dying off. You may know that scientists have called this epidemic "CCD," or colony collapse disorder, where honeybees seem to lose the ability to find the hive again, and disappear forever. Scientists think CCD may be caused by a virus, or a combination of other factors, such as the presence of pesticides or the poor nutrition and high antibiotic use of commercial bee populations. There are other theories too.
Nature on PBS reports that, if the rate of collapse continues, all honeybee populations in the US will die out by 2035.
But did you know there is an area in China where this has already happened? And pollination has to happen by hand?Read the rest of this post... Read the comments on this post...




//////////////////////DARWINS BULLDOG-GLB=On this day in 1895, T. H. Huxley died at the age of 70. Huxley was known as "Darwin's Bulldog" because of his defense of Darwin's important work in evolution. He debated Samuel Wilberforce in 1860, and people have been debating creationists since.
Huxley invented the term "agnostic" and described himself as one.



///////////////////////EMOTIONAL=JASBATEIN



/////////////////MM="Psychological essentialism in selecting the 14th Dalai Lama"
Posted: 28 Jun 2008 06:02 PM CDT
There's an interesting short paper by Paul Bloom and Susan Gelman in the July issue of Trends in Cognitive Science with that title. Unfortunately, it's not yet available without a subscription (though Bloom tends to put his papers on his website once published, so it might show up there sometime in the near future), but if you have a subscription or access to a university library, you can read it here.
If you're not familiar with the idea, "psychological essentialism" is the belief that entities have an internal set of necessary properties, or an essence, that make them what they are. For example, people tend to believe that there's something about tigers (their DNA, perhaps) that make them tigers. There's a great deal of evidence that people are "psychological essentialists" about natural kinds (animals, elements, that sort of thing), and a growing body of evidence that we tend to be psychological essentialists when it comes to certain social categories as well, like gender, race, and sexual orientation.
Bloom and Gelman relate the story of the selection of the 14th Dalai Lama, in which those doing the selection presented a child with objects that the 13th Dalai Lama had owned, as well as similar objects, and observed which of the objects the child selected. Since he picked all of the objects that had belonged to the Dalai Lama, he was chosen to be the 14th, and current Dalai Lama. They conclude:
Our point here is not that the authentic objects were actually imbued with the essence of the 13th Dalai Lama (a metaphysical question that is beyond the scope of our inquiry). What matters is that the Tibetan bureaucrats believed that the objects were. Hence they constructed a procedure that presupposes the existence of invisible essences - essences that require special powers to perceive - and used this procedure to make a decision of major importance. We take this as evidence of the ubiquity, naturalness and importance of psychological essentialism. (p. 243)
Bloom, P. & Gelman, S.A. (2008). Psychological essentialism in selecting the 14th Dalai Lama. Trends in Cognitive Science, 12(7), 243.Read the comments on this post...



///////////////////Revolution is not something fixed in ideology, nor is it something fashioned to a particular decade. It is a perpetual process embedded in the human spirit. -- Abbie Hoffman




//////////////////Youth is not the age of pleasure; we then expect too much, and we are therefore exposed to daily disappointments and mortifications. When we are a little older, and have brought down our wishes to our experience, then we become calm and begin to enjoy ourselves.
- Lord Liverpool



///////////////////

SKEPTIC

Swayonomics
Michael Shermer1
BOOK REVIEWED-Sway: The Irresistible Pull of Irrational Behavior
by Ori Brafman & Rom Brafman
Currency/Doubleday: 2008. 224 pp. $21.95
In the Biblical parable in Matthew 25:14–29, a servant who was given five talents of money invested them and returned ten talents, whereas a servant given one talent buried it in the ground without profit. The master gave the risk-averse servant's one talent to his successful rival. The effect was elevated into a principle: "For to everyone who has, more shall be given, and he will have an abundance; but from the one who does not have, even what he does have shall be taken away."
Sometimes named the 'Matthew Effect', marketers call this response 'cumulative advantage'. I think of it as the 'bestseller effect'. Every author and publisher knows that once a book gets a head-start in sales it signals to consumers that other people want that book, causing them to desire it and purchase more, so the richest authors get even richer.
In Sway, the brother authors Ori Brafman, an entrepreneur, and Rom Brafman, a psychologist, describe the social and psychological effects that shape our beliefs and behaviours. They hope to trigger their own Matthew Effect with this highly readable book. But predicting the next bestseller is as reliable a business as astrology. That problem affects all books, including, ironically, those about marketing and behaviour: the psychological principles may explain what happened in hindsight, but cannot be used to predict the future.
Sway is a fun read, and the brothers Brafman are compelling storytellers, pulling in the reader immediately and narrating at a breezy pace. But the book is thin on science and thick on anecdotes. The authors have a propensity for 'just-so' stories, favouring this or that behavioural principle when other explanations exist.
The book opens, for example, with the tragic 1977 crash of KLM flight 4805 during take-off from the tiny Tenerife airport in the Canary Islands. While motoring down the runway, the Boeing 747 slammed into Pan Am flight 1736, also a 747. The crash was the worst disaster in aviation history. What was the cause? The authors argue that it was psychological. The KLM captain Jacob Veldhuyzen van Zanten was a top pilot, featured in airline advertisements, who took pride in getting his passengers to their destination on time. That day he was behind schedule, having been rerouted to Tenerife after a bomb threat at his destination airport, and delayed on the island by fog. Captain van Zanten worried about his reputation for punctuality. "An unseen psychological force was at work," claim the authors, "steering van Zanten off the path of reason." This force was "loss aversion". Behavioural economists have shown that when we make a decision, potential losses hurt twice as much as potential gains feel good. "This principle is key to understanding van Zanten's actions," the Brafmans explain. He dreaded "the cost of putting up the passengers, the chain reaction of delayed flights and the blot on his reputation for being on time".
People find evidence for what they already believe and ignore anything contrary.
Baloney. Van Zanten's plane was one of several large aircraft diverted to Tenerife. They manoeuvred tightly around the runway, the taxiway that ran parallel to it and four small connector taxiways between the two. Several spilled over onto the taxiway, so some planes had to taxi up the runway, turn around, and then take off down that same runway. Van Zanten did this, but after turning around in preparation for take-off, the fog reduced visibility to 300 metres. Unknown and invisible to van Zanten, at the same time Pan Am 1736 had been instructed to taxi down the same runway and take the third exit on its left in order to avoid the KLM flight's take-off. After clarifying which exit to take — "The third one, sir; one, two, three, third, third one" the controller emphasized — the Pan Am jet counted them off against an airport diagram. The cockpit voice recorder revealed that the Pan Am crew identified the first two connecting taxiways, but missed the third; the collision happened near the fourth exit.
Meanwhile, in the KLM plane, van Zanten's co-pilot radioed the tower for clearance. The tower did not clear them for take-off immediately. At this moment, a call from the Pan Am jet to the tower caused interference on the radio. The Pan Am crew signalled that they were still on the runway, but because of the radio interference the KLM crew did not hear the message, and began their fateful take-off sequence. The airport lacked ground radar so no one could locate the planes. By the time van Zanten saw the Pan Am plane it was too late. He throttled his engines full and pulled up the nose of the plane, but his fuselage clipped the top of the Pan Am jet, ripping it to shreds. The Pan Am pilot hit his engines and turned sharply into the exit path, but it was too little too late. Total death toll: 583.
The cause of this crash, investigators concluded, was a concatenation of conditions, none of which had anything to do with the psychology of loss aversion: bad weather, crowded conditions, big planes on a small runway, and misinterpretations and false assumptions.
Even if we grant the brothers Brafman the option of looking for an 'ultimate' instead of 'proximate' cause of the crash in the form of cognitive biases and behavioural persuaders that drove van Zanten to make his fateful decision to take off, loss aversion would be low on a causal vector list. Top of my list would be the 'confirmation bias', in which people look for and find confirmatory evidence for what they already believe and ignore evidence to the contrary. Once van Zanten thought he got the "OK" for take-off, everything else made sense. Or, perhaps it was the effect of 'inattention blindness', in which people attend to one task so intently that they miss obvious things in their visual field. Or it could be the 'self-serving bias' and the 'better-than-average bias' that made van Zanten overconfident in his abilities and thus less risk-averse than he might normally be. Maybe there was a 'priming effect', such that van Zanten's brain was primed to hear "take-off" in that garbled radio message. Or how about just the power of expectation?
The real problem here is the hindsight bias. Not for van Zanten, but for observers trying to read into a past event psychological effects that have been measured in the laboratory. The research on cognitive biases and judgemental heuristics — cleverly used in the service of reconstructing past events by the authors of Sway — is well grounded in empirical data, but the Brafman brothers face the same problem as the rest of humanity in trying to make sense of seemingly chaotic human behaviour: those very same biases operate in the process of using them to explain someone else's behaviour. Call it the 'meta-heuristic' bias.


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EURO FOOTBALL 08 CHMPNSHP-SPAIN VS GRMNY-TRUTH IS THE CHILD OF TIME






////////////////MADRID VS BARCELONA









//////////////////WIKI=Elliteration enforces each expression emenating "e". Ensuring every essayist's edits errorless effectiveness. Encyclopedia evidence establishes e's elevation exceeding extra elements. Engineering enigmatic expositions entails extravagant effort. Elliteration entices etymological echoes. Etruscans emerged early exercising elliteration. Enlightened enchiridions estimate ending elliterative exhibitions.









//////////////////////I first learned the concepts of non-violence in my marriage. -- Gandhi








///////////////////Evolutionarily Preserved Signature Found In The Primate Brain (June 24, 2008) -- Researchers have determined that there are hundreds of biological differences between the sexes when it comes to gene expression in the cerebral cortex of humans and other primates. These findings indicate that some of these differences arose a very long time ago and have been preserved through evolution. These conserved differences constitute a signature of sex differences in the brain. ... > full story








///////////////////sd=Infant Play Drives Chimpanzee Respiratory Disease Cycles (June 23, 2008) -- The signature boom-bust cycling of childhood respiratory diseases was long attributed to environmental cycling. However, the effect of school holidays on rates of social contact amongst children is increasingly seen as another major driver. New research on chimpanzees suggests that this effect of social connectivity on disease cycling may long predate attendance of children at schools, with chimpanzee infant mortality rates cycling in phase with rates of social play amongst infants. ... > full story










/////////////////Identification Of A Tumor Suppressor Gene Associated With Patient Outcome In Neuroblastoma (June 27, 2008) -- Expression of the CHD5 gene is frequently down-regulated in neuroblastomas, and patients whose tumors lacked CHD5 expression were more likely to have shorter event-free and overall survival compared with patients whose tumors expressed CHD5, according to a study in the June 24 issue of the Journal of the National Cancer Institute. ... > full story








//////////////////It's Email, But At A Snail's Pace (June 26, 2008) -- Bournemouth University researchers are using live snails to send emails as part of a 'slow art' project aimed at encouraging people to explore notions of time. ... > full story


























///////////////////////////FIFA remembers Argentina 1978 as ‘a great World Cup’
Posted: 26 Jun 2008 10:23 PM CDT
By Sebastian Fest Madrid, June 27 (DPA) It has been 30 years, but FIFA stands by its interpretation of the 1978 World Cup in Argentina: It was “a great World Cup”. And any country on the planet, even a bloody dictatorship, has the right to host a World Cup. “It seems that the way fans and the [...]




MARIO KEMPES-ANANDAMELA-NANDY SIR




////////////////////Daman and Diu has worst sex ratio in India
Posted: 26 Jun 2008 12:34 PM CDT
New Delhi, June 26 (IANS) The union territory of Daman and Diu has the lowest sex ratio in the country - 710 women for every 1,000 men, an association of gynecologists said Thursday. The Associations of Obstetricians and Gynecologists of Delhi (AOGD) found that Kerala has the best ratio (1,058 women for 1,000 men). The association [...]








/////////////////SW=BUDDHA=
“He insulted me, hit me, beat me, robbed me”
for those who brood on this, hostility isn’t stilled.
“He insulted me, hit me, beat me, robbed me”
for those who don’t brood on this, hostility is stilled.
Hostilities aren’t stilled through hostility, regardless.
Hostilities are stilled through non-hostility: this, an unending truth.






//////////////////Grief Linked To Brain Pleasure Centersby Kate Melville
Everyone experiences grief at some point in their lives, but for a substantial number of people it's impossible to ever move on, and even years later, any reminder of their loss brings on a fresh wave of grief and yearning. Now, scientists at the University of California - Los Angeles (UCLA) have been using brain-imaging techniques to try and understand why some people grieve and ultimately adapt, while others can't get over the loss. Their findings, reported in the journal NeuroImage, suggest that long-term (complicated) grief activates neurons in the reward centers of the brain, possibly giving these memories addiction-like properties.
The new study is the first to compare complicated and noncomplicated grief, and the findings may help psychologists do a better job of treating those with complicated grief, according to UCLA's Mary-Frances O'Connor, lead author of the study. "The idea is that when our loved ones are alive, we get a rewarding cue from seeing them or things that remind us of them," O'Connor explained. "After the loved one dies, those who adapt to the loss stop getting this neural reward. But those who don't adapt continue to crave it, because each time they do see a cue, they still get that neural reward. Of course, all of this is outside of conscious thought, so there isn't an intention about it."
The study analyzed whether those with complicated grief had greater activity occurring in either the brain's reward network or pain network than those with noncomplicated grief. The 23 women in the study had all lost a mother or a sister to breast cancer and 11 had complicated grief, while 12 had the more normal, noncomplicated grief. Each of the participants brought a photograph of their deceased loved one and were shown this picture while undergoing fMRI brain scanning.
Specifically, the researchers looked for activity in the nucleus accumbens, a region of the brain usually associated with reward (and interestingly, one that has also been shown to play a role in social attachment, such as sibling and maternal affiliation). They also examined activity in the pain network of the brain, including the dorsal anterior cingulate cortex and the insula, which has been implicated in both physical and social pain. They found that while both groups had activation in the pain network of the brain after viewing a picture of their loved one, only individuals with complicated grief showed significant nucleus accumbens activations.
O'Connor notes that such activations are not emotionally satisfying for the griever, but rather that they may serve in some people as a type of craving for the reward response that may make adapting to the reality of the loss more difficult.




////////////////////A Spicy Meal Before Bed Can Disrupt Sleep: An old wives' tale has it that a little kick to the palate before bed can lead to fitful sleep, if not nightmares. It's the sort of wisdom that often turns out to be based on no evidence at all - or, worse, flat wrong. But in this case, as NYTimes.com/Health reports, it is good advice.



///////////////qp=Leaving Academia: Cry or Celebrate?
Posted: 25 Jun 2008 12:25 PM CDT
No, no, I'm not leaving academia (yet :) Pfffffft! That's the sound of me thumbing my nose at the world.) But recently I was thinking about about people who get a Ph.D. in, say, physics, or are a new postdoc, and then are faced with what to do next. As Peter Rhode, writes in a post today (or whatever day it is in the upside down part of the world) entitled "Farewell physics":
The academic system has some serious problems. Most notably in my opinion, there is very limited scope for promotion. For every permanent position there are countless postdocs competing for that position. It simply isn't possible for all of us post-docs to progress right up through the ladder. Many of us will be stuck as postdocs for the indefinite future. Realistically, I could expect to spend the next 5 or even 10 years as a post-doc before a permanent position would come along, and even then I would have very little control over where I would end up. I've seen many outstanding colleagues in exactly this position....
There is a huge salary discrepancy between academia and the private sector. With the same qualifications one can earn twice as much in the private sector than as a post-doc.Peter, like others before him, has decided that the academic rat race is not the path he wants to take, and is therefore heading out for greener pastures. Of course my first reaction, I'll admit, is one of sadness: I've read some papers by Dr. (err DJ) Rhode, and enjoyed them. By contributing to quantum information science, he's become part of a community I consider myself a (annoying, loud, insert random invective here) member of. But, in thinking about this, I realized, that I've got it all wrong. Read the rest of this post... Read the comments on this post...




//////////////Online Service Lets Blind Surf The Internet From Any Computer, Anywhere (June 27, 2008) -- New software lets blind and visually impaired people surf the Internet on the go. The computer science student who created the software, called WebAnywhere, says more accessibility tools must move from desktop machines to the Web. ... > full story




////////////////////// Can Weeds Help Solve the Climate Crisis? By TOM CHRISTOPHERWeedy ancestors of our food crops, some scientists predict, will cope far better with coming climatic changes than their domesticated descendants.



//////////////////Binge Drinking Due To 'Copying' Behavior (June 28, 2008) -- The rise in binge drinking in the young is a "fashion phenomenon" where drinkers are copying their associates' behavior, new research carried out in the UK has shown. Researchers say the findings have major implications for Government policy makers charged with tackling the problem, which has longer-term and costly health implications. ... > full story




///////////////////GLUTEN=WHEAT MEAT



//////////////////////natr=Planetary science: The burger bar that saved the world p1164Fewer people are searching for near-Earth asteroids, astronomer David Morrison said in the 1990s, than work a shift in a small McDonalds. But that group — a little larger now — has over the past two decades discovered a host of happily harmless rocks, and in doing so reduced the risk of an unknown asteroid blighting civilization (see page 1178). David Chandler puts together the story in the words of those who watched, and those who watched the watchers.doi:10.1038/4531164a



//////////////////Making genetic history
Jerry A. Coyne1
BOOK REVIEWED-In Pursuit of the Gene: From Darwin to DNA
by James Schwartz
Harvard University Press: 2008. 384 pp. $29.95, £19.95, 22.50
BETTMANN/CORBIS
Fruitful collaborations were formed in Thomas Hunt Morgan's fly genetics lab.
When I was a student, 'doing genetics' meant crossing two different strains or species. Now it means sequencing DNA, preferably human. Between these two poles lies the history of genetics, a pathway fraught with sharp turns, steep gradients and dead ends — and engagingly recounted in James Schwartz's new book.
Despite its subtitle, In Pursuit of the Gene is not a comprehensive history of genetics, but focuses solely on classical genetics. Schwartz, a science writer, begins with Charles Darwin's ill-fated 'pangenesis' theory of the inheritance of acquired characteristics, and runs through the rediscovery of Gregor Mendel's work on inherited traits. The story continues with the consolidation of Mendelism and chromosomal inheritance by Thomas Hunt Morgan and his students in the 'Fly Room' lab at New York's Columbia University, where modern genetics began, and concludes in 1946 with Hermann Joseph Muller's Nobel Prize in Medicine for inducing mutations with X-rays. Later history, from the discovery by Oswald Avery and colleagues that DNA was the 'transforming principle', to the Human Genome Project, is squeezed into a 12-page epilogue. Those seeking a history of molecular genetics should read Horace Freeland Judson's magisterial The Eighth Day of Creation (Simon & Schuster, 1979).
Many histories of genetics cover the same ground. What distinguishes Schwartz's account is his impeccable scholarship, based on many primary sources, and his ability to keep the narrative moving, interweaving discoveries with the strong and eccentric personalities who made them. He does not slight the science, describing experiments in detail so dense that the reader is advised to keep a pencil and paper handy. The effort required to understand the book may, sadly, remove it from the ambit of popular science.
The book's apogee is its tale of the "Mendel Wars" around the beginning of the twentieth century, the struggle to bring together Mendel's ideas on heredity and Darwin's theory of evolution. On one side were the Mendelians, including Francis Galton, William Bateson and Charles Hurst, who accepted Mendelism but considered natural selection as ineffective, seeing evolution as occurring by 'macromutations', or single genetic changes of very large effect. On the other side stood the biometricians, most notably Karl Pearson and Raphael Weldon, who accepted the ubiquity of Darwinian selection but rejected Mendelian genetics. Given the strong egos involved and the fundamental nature of the science at stake, the battles Schwartz recounts were fierce. Friendships were destroyed, careers threatened. After a particularly contentious meeting about the genetics of horse coat colour at the Royal Society in London, Pearson hissed at Hurst, "You shall never be Fellow here as long as I live".
Other high spots in the book include the early and now largely forgotten work on cytological genetics by Walter Sutton and Edmund B. Wilson, involving years of eye-strain from squinting at confusing chromosomal preparations of sea urchins, aphids and grasshoppers. These studies established that different chromosomes carry different hereditary factors, yet occur in pairs that become separated during the formation of gametes in meiosis, giving essential physical support for Mendel's laws.
The book's longest section details the immense contributions of research on the fruitfly Drosophila melanogaster to our understanding of heredity. Schwartz explains how, from 1912 to around 1930, Morgan and his 'boys', Alfred Sturtevant and Calvin Bridges, along with Muller, were "responsible for the integration of Mendelism and the chromosome theory that is the basis of genetics". Within a few years, this conjunction of remarkable intellects in a tiny laboratory led to methods for mapping chromosomes both genetically and cytologically, and to the discovery of sex linkage, chromosome inversions, nondisjunction and many other phenomena that now form the dogma of transmission genetics.
Alas, here we find a major flaw. Schwartz notes that he was inspired to write his history by reading Elof Carlson's worshipful biography of Muller, Genes, Radiation, and Society (Cornell University Press, 1981). But this only generates further hagiography: the discussion of Muller's work occupies a quarter of In Pursuit of the Gene, a disproportionate chunk. Schwartz gives the impression that Muller, or ideas purloined from him by others, was behind nearly every advance in fly genetics. Sturtevant's contributions are given short shrift, Morgan is portrayed as a conniver who acquired his Nobel status on the backs of his students, and Bridges — perhaps the finest pair of eyes ever to peer at a magnified fly — is dismissed as being "famous for stealing other men's wives as well as their ideas". Schwartz does not mention the work of Lewis Stadler, who independently discovered X-ray induction of mutations in barley at the same time as Muller's work on Drosophila. Like many plant geneticists, Stadler was marginalized as a glorified crop breeder.
It is easy to sympathize with Muller, who had a tumultuous life and was the perennial underdog: Jewish, short, bald and with a high voice. Fractious, and possessed of unpopular socialist views, he floated from university to university, winding up in the Soviet Union until he fled to escape Trofim Lysenko's destruction of Russian genetics. Yet during all these peregrinations he maintained an uninterrupted programme of research. It is a scandal that Muller did not secure a tenured academic job until he was 55 — he won the Nobel prize a year later.
Muller was one of the best geneticists of the twentieth century, a visionary who predicted the rise of molecular genetics and the use of association mapping to identify genes for human behaviours. He was also difficult to work with, obsessed with credit and depressive to the point of once attempting suicide. Schwartz repeatedly states that Sturtevant, Bridges and Morgan tried to ruin Muller's reputation by stealing his ideas and slandering him, but the evidence is unconvincing. Working together in the Fly Room, talking science as they worked on flies in what was a continuous lab meeting, it is not surprising that they shared ideas and information. After all, it was Sturtevant who gave Muller the idea of using lethal alleles to measure mutation rates.
The other 'boys' were not slouches. Bridges discovered nondisjunction, thereby proving the chromosomal theory of heredity, and published it as the first paper in the first issue of the journal Genetics. He constructed the first map of genes on autosomes, did fundamental work on sex determination and produced maps of Drosophila salivary-gland chromosomes that have never been bettered. Sturtevant was the first to establish, while still an undergraduate, that genes are arrayed linearly on chromosomes. He devised the chromosomal fate mapping later used so effectively by the geneticist Seymour Benzer, founded Drosophila taxonomy and, by studying the action of eye-colour mutations in the fly, became the father of biochemical genetics. But neither Sturtevant nor Bridges was obsessed with priority: Sturtevant was the most modest of men, whereas Bridges, a great womanizer, had more pressing interests.
In Pursuit of the Gene should be required reading for all biologists unfamiliar with the history of genetics. Schwartz shows how quickly science can advance when a group of first-class minds encounters a fertile but unploughed field. Progress in genetics, as in all modern science, was truly a collaborative affair. There was no Darwin of genetics — not even Muller. There was, and is, plenty of credit to go around.



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Saturday 28 June 2008

MAIN STREAM SUCCESS-CDS 290608

//////////////relishing the rhetoric


////////////TG=

Homosexual behavior due to genetics and environmental factors

Posted: 28 Jun 2008 08:49 PM CDT

Homosexual behavior is largely shaped by genetics and random environmental factors, according to findings from the world’s largest study of twins.

Writing in the scientific journal Archives of Sexual Behavior, researchers from Queen Mary’s School of Biological and Chemical Sciences, and Karolinska Institutet in Stockholm report that genetics and environmental factors (which are specific to an individual, and may include biological processes such as different hormone exposure in the womb), are important determinants of homosexual behavior.

Dr Qazi Rahman, study co-author and a leading scientist on human sexual orientation, explains: “This study puts cold water on any concerns that we are looking for a single ‘gay gene’ or a single environmental variable which could be used to ’select out’ homosexuality - the factors which influence sexual orientation are complex. And we are not simply talking about homosexuality here - heterosexual behaviour is also influenced by a mixture of genetic and environmental factors.

The team led by Dr Niklas Långström at Karolinska Institutet conducted the first truly population-based survey of all adult (20-47 years old) twins in Sweden. Studies of identical twins and non-identical, or fraternal, twins are often used to untangle the genetic and environmental factors responsible for a trait. While identical twins share all of their genes and their entire environment, fraternal twins share only half of their genes and their entire environment. Therefore, greater similarity in a trait between identical twins compared to fraternal twins shows that genetic factors are partly responsible for the trait.

This study looked at 3,826 same-gender twin pairs (7,652 individuals), who were asked about the total numbers of opposite sex and same sex partners they had ever had. The findings showed that 35 per cent of the differences between men in same-sex behavior (that is, that some men have no same sex partners, and some have one or more) is accounted for by genetics. Rahman explains:

“Overall, genetics accounted for around 35 per cent of the differences between men in homosexual behavior and other individual-specific environmental factors (that is, not societal attitudes, family or parenting which are shared by twins) accounted for around 64 per cent. In other words, men become gay or straight because of different developmental pathways, not just one pathway.”

For women, genetics explained roughly 18 per cent of the variation in same-sex behavior, non-shared environment roughly 64 per cent and shared factors, or the family environment, explained 16 per cent.

The study shows that genetic influences are important but modest, and that non-shared environmental factors, which may include factors operating during fetal development, dominate. Importantly, heredity had roughly the same influence as shared environmental factors in women, whereas the latter had no impact on sexual behavior in men.

Dr Rahman adds: “The study is not without its limitations - we used a behavioral measure of sexual orientation which might be ok to use for men (men’s psychological orientation, sexual behavior, and sexual responses are highly related) but less so for women (who show a clearer separation between these elements of sexuality). Despite this, our study provides the most unbiased estimates presented so far of genetic and non-genetic contributions to sexual orientation.”

Source: Queen Mary, University of London

Genetic and Environmental Effects on Same-sex Sexual Behavior: A Population Study of Twins in Sweden. Niklas Långström, Qazi Rahman, Eva Carlström and Paul Lichtenstein. Archives of Sexual Behavior.

Josh says:

I’m glad studies like this are coming out (pun not intended). Once someone’s neurological structure is such that they’re gay, then it cannot be changed; the same goes for someone who is straight. I think many aspects of intelligence work this way as well - there is a proportionally smaller genetic component, but environmental factors during neurological development play the largest role.



///////////////////////////////STRIKE FATIGUE



/////////////////////EATING CHICKEN IS A PRIVILEGE NOT A RIGHT-SUPPORT PETA



/////////////////////HERE AND THERE LEADS TO NOWHERE



///////////////////////MONEY HAI TO HONEY HAI


////////////////////LEARNED HELPLESSNESS OF THE POOR IN FACING NATRL DISASTERS-NYANMAR,NIDNAPORE


/////////////////////////If I try to be like him, who will be like me?
-- Yiddish Proverb

It is thus with most of us; we are what other people say we are. We know ourselves chiefly by hearsay.
-- Eric Hoffer



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‘Martian Soil Good For Asparagus’

David Usborne

New York, June 28: Bad for strawberries, great for asparagus and turnips. This is the small-print for gardening enthusiasts buying a second home on Mars, should the day ever arrive when humans colonise it.
Scientists in charge of analysing soil lifted from the surface of the planet by the Nasa space probe Phoenix have admitted to being “flabbergasted” by initial results, which suggest it would theoretically be just about perfect for certain vegetables that thrive in mildly alkaline conditions.
The tiny sample of soil ~ one cubic-centimetre ~ was lifted from the planet's surface with a robotic arm. It was then mixed with water on board the lander to create a kind of Martian mud suitable for chemical analysis. Phoenix set down on the planet last month.
Most scientists had long assumed there would be little on the surface of the planet that would be hospitable to supporting life. But last week they were forced to change their thinking.
“We have found what appear to be the requirements, the nutrients, to support life whether past, present or future,” said Dr Samuel Kounaves of Tufts University near Boston. “The sort of soil you have there is the type of soil you'd probably have in your back yard.”
The pH level of the sample was somewhere between 8 and 9, with 7 considered neutral. This would seem perfect for growing asparagus and other vegetables, such as green beans, that do not do well with acidity. This does not mean that dropping seeds now would produce a vegetable patch, given everything else about the planet’s environment, including, of course, the lack of water.
Even the water question has been the subject of excitement since Phoenix began its work. In an earlier experiment, soil was heated on board the lander to 1,800F, which resulted in the release of water vapour. This suggests that this part of the planet at least was in contact with water at some point, although nobody can say when that was or the volume of water involved.
“This soil clearly has interacted with water in the past,” said Dr William Boynton, of the University of Arizona, who led the water content experiment. He added that it could have come in dust particles blown from a different part of the planet.
~ The Independent




////////////////////////Quarter of the planet to be online
by 2012
iTnews June 26, 2008
*************************
The total number of people online
will climb to 1.8 billion by 2012,
encompassing roughly 25 percent of
the planet, with the highest growth
rates in areas such as China,
Russia, India and Brazil, according
to a report by Jupiter Research.
Asia will have the highest online
growth rate compared to other
regions in the world, ans a large
pool of...
http://www.kurzweilai.net/email/newsRedirect.html?newsID=8950&m=33138


///////////////////////THE DARK SIDE OF SUBURBIA


//////////////////////
We never know the worth of water till the well is dry.

— Thomas Fuller



////////////////////NS=

Artificial brain predicts death-row executions

  • 25 June 2008
  • Paul Marks
  • Magazine issue 2662

WHICH inmates on death row will eventually be executed? Many never make the final journey from prison cell to execution chamber - but nobody really understands who will be spared.

Until now. A new computer system can predict which death row prisoners will live and which will be killed - with chilling accuracy. And its dispassionate analysis has confirmed suspicions that the people most likely to be executed are those who have had the least schooling, rather than those who have committed the most heinous crimes.

The US, the only western democracy to retain the death penalty, executes only a small proportion of the people it sentences to death. For instance, just 53 of the 3228 inmates on death row were executed in 2006.

So how were those 53 chosen? "We couldn't see any clear patterns in the data," says computer scientist Stamos Karamouzis, who has been investigating this question ...



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Omega-3s are twice as important for girls as boys

  • 27 June 2008
  • Nora Schultz
  • Magazine issue 2662

PARENTS of daughters, listen up. Eating enough omega-3 fatty acids is twice as important for boosting the brainpower of girls as it is for boys.

Several studies have upheld the link between intelligence and higher consumption of omega-3 fats, especially those found in fatty fishes such as salmon. William Lassek at the University of Pittsburgh in Pennsylvania and Steve Gaulin at the University of California, Santa Barbara, wondered whether this effect might be even stronger in girls because women not only use omega-3 fats to build their brains, they also store them on their hips and thighs in preparation for nurturing the brains of their future babies. "The lower body fat is like a bank into which deposits are made during childhood and only withdrawn during pregnancy and nursing," says Lassek.

Using data from the National Health and Nutrition Examination Survey in the US, the pair compared consumption of the ...



/////////////////////LONG DISTANCE DAD


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BBC News
Happy 60th birthday, NHS
Independent - 6 hours ago
Aneurin Bevan's creation remains a vital part of British life after six decades. Ian Johnston reports 'Preventable pain is a blot on any society.




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Hawking 'close' to explaining universe's inflation

  • 28 June 2008
  • Zeeya Merali
  • Magazine issue 2662

WHY was the big bang so very big? It has been a struggle to explain why the infant universe expanded so rapidly. But now Stephen Hawking at the University of Cambridge, and colleagues, think they are close to perfecting an answer - by treating the early cosmos as a quantum object with a multitude of alternative universes that gradually blend into ours.

The idea that the universe expanded at a blistering rate in the first 10-34 seconds after the big bang was proposed to explain why regions of the universe separated by vast distances have such a similar background temperature: before inflation occurred, these regions would have been close together with similar properties. But just why the universe inflated in the first place remains a mystery.

"There's no fundamental theory that can explain why inflation happened in our universe - it's just proposed as an ad hoc solution that explains ...

The complete article is 801 words long.


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Thursday 26 June 2008

CDS 2606082200

////////////////////EGEST: to excrete ("this protein is e. by healthy cells")EGLOMERATE: to unwind ("at room temperature the protein e. rapidly")EGOTHEISM: self-deification ("the professor suffered from e. but, unfortunately for him, all his students were atheists")EIDETIC: pertaining to the ability of visualising anything previously seen ("when it comes to protein folds, Brändén is the most e. person I know")EISTEDDFOD: annual assembly of Welsh poets and musicians ("no, professor Jones isn't here; he's off to the e. conference in Cwmbrmwrddll")ELLIPSIS: deletion of words from a sentence ("PhD-student first draft manuscript always suffer e.")EMBULALIA: insertion of nonsense into speech ("e. is an old trick to check if your audience is still paying attention")EMPRESSEMENT: extreme politeness ("whatever happened to that good old Swedish e. ?")ENATATION: escape by swimming ("e. is when your crystal floats out of your capillary while you're not watching")ENCHIRIDION: manual ("who took my "O"-e. ?")ENDOGAMOUS: pertaining to marriage within one's group ("we have at least ten e. scientists in our lab")ENERGUMEN: fanatic ("that e. worked on his averaging until 5 a.m.")ENIGMATOLOGY: science of solving enigmas ("before using Unix, first take a course in e.")ENSYNOPTICITY: ability of taking a general view of something ("if you can twist the zoom dial in "O", you have e.")ENTHEOMANIA: abnormal state in which one thinks one is inspired ("whenever I feel e. coming up, I go home and get some sleep")EOPROLIGERY: ability to reproduce early ("e. is when you manage to consistently get one crystal form if you set up your drops before 6 a.m.")EPEXEGETIC: pertaining to further explanation ("you have to be a bit more e. when you write about the structure-function relations")EPHEMEROMORPH: low form of life which defies animal or vegetable classification ("the student got depressed when his supervisor called him an e.")EPICARICACY: taking pleasure in others' misfortune ("many scientists suffer from severe e.")EPIDEICTIC: impressive; for display purposes ("our ESVs are mainly e.")EPILEGOMENON: added remark ("that snob calls a note-added-in-proof an e.")ERGASIOPHOBIA: fear of or aversion to work ("there's no place for e. in our lab")ERGOPHILE: someone who loves work ("there's no place for e. in their lab")ESQUAMATE: having no scales ("if you just concatenate two reflection files you'll get an e. dataset")



///////////////////Neuroscientists Discover A Sense Of Adventure (June 26, 2008) -- Wellcome Trust scientists have identified a key region of the brain which encourages us to be adventurous. The region, located in a primitive area of the brain, is activated when we choose unfamiliar options, suggesting an evolutionary advantage for sampling the unknown. It may also explain why rebranding of familiar products encourages to pick them off the supermarket shelves. ... > full story



///////////////////Use of Pulse Oximetry to Detect Congenital Heart Disease
Neonatal screening pulse oximetry improved detection of critical CHD.
Routine physical examination fails to detect at least half of critical congenital heart disease (CHD) cases. In the largest study to date, investigators used pulse oximetry to screen for CHD on admission to the newborn nursery in 50,000 infants (86% of nearly 58,000 live births) delivered at 14 Norwegian hospitals in 2005 and 2006.
In 1360 newborns who failed the initial screening test (postductal arterial oxygen saturation [SpO2] <95%), 324 results were considered pathologic because of symptoms or persistent SpO2 <95% on repeat testing. Diagnoses among these 324 cases included CHD (43 infants), pneumonia-septicemia (55), transient tachypnea (54), and prolonged transitional circulation (147). At age 6 months, 658 of the 58,000 screened and unscreened infants had CHD diagnoses. Of these, 46 cases (7%) were diagnosed prenatally and 40 (6%) were detected before discharge by pulse oximetry screening. Remaining cases were detected by routine physical exam in the nursery (320), after admission to the neonatal ICU (178), or after discharge (74). Among infants with critical CHD (e.g., ductus-dependent lesions), pulse oximetry screening detected 27 of 35 cases (sensitivity, 77%; specificity, 99%; false-positive rate, 0.6%).
Comment: As noted by an editorialist, determining the possible role of neonatal pulse oximetry screening is complicated. Screening infants before 24 hours of age increases the number of false-positive tests but also improves early detection of newborns with critical CHD. The optimal SpO2 cutoff also is debatable. Whether nurseries should institute routine screening or continue to rely on physical examination likely depends on the balance between the clinical burden and expense of evaluating false-positive tests versus the potentially improved clinical outcomes and cost savings associated with early detection, particularly of critical CHD.
Howard Bauchner, MD
Published in Journal Watch Pediatrics and Adolescent Medicine June 25, 2008

SO R/V MURMUR NEXT DAY AND DO SATS



////////////////////////FLD MRSHLL MANECKSHAW RIP


///////////////////QUIET SENSE OF PURPOSE



///////////////////There was a time when a fool and his money were soon parted, but now it happens to everybody.
- Adlai Ewing Stevenson



///////////////////How the Mind Works: Revelations
By Israel Rosenfield, Edward Ziff
The Physiology of Truth: Neuroscience and Human Knowledge
by Jean-Pierre Changeux, translated from the French by M.B. DeBevoise
Belknap Press/Harvard University Press, 324 pp., $51.50
Nicotinic Acetylcholine Receptors: From Molecular Biology to Cognition
by Jean-Pierre Changeux and Stuart J. Edelstein
Odile Jacob, 284 pp., $99.00
Conversations on Mind, Matter, and Mathematics
by Jean-Pierre Changeux and Alain Connes, translated from the French by M.B. DeBevoise
Princeton University Press,260 pp., $26.95 (paper)
What Makes Us Think? A Neuroscientist and a Philosopher Argue about Ethics, Human Nature, and the Brain
by Jean-Pierre Changeux and Paul Ricoeur, translated from the French by M.B. DeBevoise
Princeton University Press,335 pp., $24.95 (paper)
Phantoms in the Brain: Probing the Mysteries of the Human Mind
by V.S. Ramachandran and Sandra Blakeslee, with a foreword by Oliver Sacks
Quill, 328 pp., $16.00 (paper)
Mirrors in the Brain: How Our Minds Share Actions and and Emotions
by Giacomo Rizzolatti and Corrado Sinigaglia, translated from the Italian by Frances Anderson
Oxford University Press,242 pp., $49.95
A Universe of Consciousness: How Matter Becomes Imagination
by Gerald M. Edelman and Giulio Tononi
Basic Books, 274 pp., $18.00 (paper)
Jean-Pierre Changeux is France's most famous neuroscientist. Though less well known in the United States, he has directed a famous laboratory at the Pasteur Institute for more than thirty years, taught as a professor at the Collège de France, and written a number of works exploring "the neurobiology of meaning." Aside from his own books, Changeux has published two wide-ranging dialogues about mind and matter, one with the mathematician Alain Connes and the other with the late French philosopher Paul Ricoeur.
Changeux came of age at a fortunate time. Born in 1936, he began his studies when the advent both of the DNA age and of high-resolution images of the brain heralded a series of impressive breakthroughs. Changeux took part in one such advance in 1965 when, together with Jacques Monod and Jeffries Wyman, he established an important model of protein interactions in bacteria, which, when applied to the brain, became crucial for understanding the behavior of neurons. Since that time, Changeux has written a number of books exploring the functions of the brain.
The brain is of course tremendously complex: a bundle of some hundred billion neurons, or nerve cells, each sharing as many as ten thousand connections with other neurons. But at its most fundamental level, the neuron, the brain's structure is not difficult to grasp. A large crown of little branches, known as "dendrites," extends above the body of the cell and receives signals from other neurons, while a long trunk or "axon," which conducts neural messages, projects below, occasionally shooting off to connect with other neurons. The structure of the neuron naturally lends itself to comparison with the branches, trunk, and roots of a tree, and indeed the technical term for the growth of dendrites is "arborization." (See the illustration below.)
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We've known since the early nineteenth century that neurons use electricity to send signals through the body. But a remarkable experiment by Hermann von Hermholtz in 1859 showed that the nervous system, rather than telegraphing messages between muscles and brain, functions far slower than copper wires. As Changeux writes,
Everyday experience leads us to suppose that thoughts pass through the mind with a rapidity that defies the laws of physics. It comes as a stunning surprise to discover that almost the exact opposite is true: the brain is slow—very slow— by comparison with the fundamental forces of the physical world.
Further research by the great Spanish anatomist Santiago Ramon y Cajal suggested why the telegraph analogy failed to hold: most neurons, instead of tying their ends together like spliced wires, leave a gap between the terminus of the neuron, which transmits signals, and the receptor of those signals in the adjacent neuron. How signals from neurons manage to cross this gap, later renamed the synaptic cleft ("synapse" deriving from the Greek for "to bind together"), became the major neurophysiological question of the early twentieth century.
Most leading biologists at that time assumed that neurons would use the electricity in the nervous system to send signals across the cleft. The average synaptic cleft is extremely small—a mere twenty nanometers wide—and though the nervous system may not function at telegraphic speed, it was not difficult to imagine electrical pulses jumping the distance. Further, given the speed with which nerves react, the alternative theory, that electrical pulses would cause a chemical signal to move across the cleft, seemed to rely on far too slow a mechanism. But as the decades passed, hard evidence slowly accumulated in support of the chemical theory. According to Changeux, experiments began to suggest that "the human brain therefore does not make optimal use of the resources of the physical world; it makes do instead with components inherited from simpler organisms...that have survived over the course of biological evolution."
A remarkable experiment by Otto Loewi in the 1920s first suggested how the brain makes use of its evolutionary inheritance in order to communicate. Loewi bathed a frog's heart in saline solution and stimulated the nerve that normally slows the heartbeat. If the slowing of the heart was caused by a chemical agent rather than an electrical impulse, Loewi reasoned, then the transmitting chemical would disperse throughout the solution. Loewi tested his hypothesis by placing a second heart in the solution. If nerve transmission was chemical rather than electrical, he supposed, then the chemical slowing down the first heart, dispersed throughout the solution, would likewise slow down the second heart. This is exactly what happened. Loewi named the substance released by the relevant nerve, called the vagus nerve, Vagusstoff; today it is known as the neurotransmitter acetylcholine. By the 1950s, further experiments had definitively proved that most neurons, while using electricity internally, must resort to chemicals to cross the synaptic cleft and communicate with the next neuron in the chain.
Changeux began his work at this stage, when the basic methods for neuron communication had been determined but the detailed chemi-cal mechanisms were just opening up to research. Thanks to new high-resolution images from electron microscopes, first taken by Sanford Palay and George Palade in 1955, biologists could finally see the minute structures of the synapse. They discovered that the transmitting end of the neuron, called the nerve terminal, comes packed with tiny sacs, or vesicles, each containing around five thousand molecules of a specialized chemical, the neurotransmitter. When an electrical signal moves down the neuron, it triggers the vesicles and floods the synaptic cleft with neurotransmitter molecules. These chemical neurotransmitters then attach to the proteins called receptors on the surface of the neuron that is located just across the synaptic cleft, opening a pore and allowing the electrically charged atoms called ions to flow into the neuron. Thus, the chemical signal is converted back into an electrical signal, and the message is passed down the line.
These processes were still somewhat mysterious in 1965, when the young Changeux, working with his teacher Jacques Monod and the American scientist Jeffries Wyman, produced one of the theories for which he became best known. The three scientists, then studying metabolism, attempted to explain how the structure of an enzyme could stabilize when another molecule attached to it. Changeux later saw a parallel with the nervous system. When a chemical neurotransmitter binds to a receptor it holds the ion pore open, ensuring its continuing function, a critical step in converting the neurotransmitter's chemical signal back into an electrical pulse. Changeux's discovery established the groundwork for the way many neurons communicate, and his findings were based on the more general paper he had coauthored with Wyman and Monod.
With a working theory for neuron communication established, Changeux then turned to the ways that larger structures in the brain might change these basic interactions. A longstanding theory, introduced by Donald Hebb in 1949, proposed that neurons could increase the strength of their connection through repeated signals. According to a slogan describing the theory, "neurons that fire together, wire together." Repeated neuron firings, Hebb believed, would produce stronger memories, or faster thought patterns. But researchers found that certain regulatory networks could achieve far more widespread effects by distributing specialized neurotransmitters, such as dopamine and acetylcholine, throughout entire sections of the brain, reinforcing connections without the repeated firings required by Hebb.
Changeux focused on these specialized distribution networks. It was long known that nicotine acts on the same receptor as the neurotransmitter acetylcholine. Changeux recognized that this could explain both nicotine's obvious benefits—greater concentration, relaxation, etc.—as well as the drug's more puzzling long-term effects. For instance, while cigarettes are dangerous to health, some studies show that smokers tend to suffer at significantly lower rates from Alzheimer's disease and Parkinson's disease. Changeux found that nicotine, by attaching to the same receptors as acetylcholine, reproduces some of the benefits of acetylcholine by reinforcing neuronal connections throughout the brain. Nicotine is not exactly the same chemically as acetylcholine, but can mimic its effects. Changeux's lab has since focused on the workings of the nicotine/acetylcholine system, and he has attempted to explain how all such regulatory systems, working together, can produce the experience we call consciousness—as well as more abstract concepts like truth.
How, then, does the mass of cells in the brain produce our experience of sight, sound, and imagination? According to Changeux, the infant brain is not a blank slate, receiving all experience and instruction—both what it sees and how to think about it—from the outside. Nor is the infant brain preprogrammed, its reactions predetermined, unable to change itself and adapt. Rather, as Changeux began to hypothesize in the late 1970s, the brain, beginning in the embryo, produces, by means of genetic action, "mental objects of a particular type that might be called prerepresentations—preliminary sketches, schemas, models."
According to this theory, spontaneous electronic activity in the brain, "acting as a Darwinian-style generator of neuronal diversity," creates dynamic, highly variable networks of nerve cells, whose variation is comparable with the variation in DNA. Those networks then give rise to the reflex movements of the newborn infant. Over time the infant's movements become better coordinated. Neural networks associated with more successful movements—such as grasping an object—are "selected"; that is, their activity is reinforced as their synaptic junctions become strengthened. As the child continues to explore his or her surroundings, Darwinian competition strengthens some of these transient networks sufficiently to make them relatively permanent parts of the child's behavioral repertoire. Changeux calls the process, first elaborated in a 1976 paper, "learning by selection."
Animals and infants conduct this miniature version of natural selection by means of what Changeux terms "cognitive games." One well-known example concerns cries of alarm in African vervet monkeys. Adult monkeys use a simple but effective vocabulary of sounds that warn against danger: a loud bark for leopards, a two-syllable cough for eagles, and a hissing sound for snakes. Surprisingly, researchers found, baby monkeys hiss at snakes without explicit instruction. Changeux writes, "Snakes seem to arouse a sort of innate universal fear, which probably developed fairly early in the course of the evolution of the higher vertebrates." When adult monkeys confirm the baby's judgment with their own hisses, the infant's genetically produced prerepresentation is rewarded and reinforced.
But baby monkeys require more explicit instruction in protecting themselves against predators, such as eagles, to which they have been less genetically conditioned. At first,
newborn monkeys react to any form that flies in the air, which is to say to the class of birds as a whole. Then, gradually, a selective stabilization of the response to the shape of dangerous species takes place.... If the first cry of alarm is sounded by one of the young, the nearest adult looks up. If it sees a harmless bird, it does not react. But if the young monkey has spotted a martial eagle, the adult reacts by emitting a cry of alarm that confirms the presence of danger.... The adult's cry of alarm validates a pertinent relationship between shape and sound that is established in the brain of the young monkey.
This process of learning alarm cries through trial and error, reward and suppression, demonstrates the kind of cognitive games that are played out constantly through the brain's interaction with the environment. As successful behaviors increase in number, Changeux believes, they strengthen the capacity to consciously manipulate the environment. Most actions are not beneficial, and as each neuron competes for limited resources, many of the least useful neurons literally die out. Changeux therefore hypothesizes: "To learn is to eliminate."
In Changeux's view, starting in the womb, spontaneous electrical activity within neurons creates highly variable networks of nerve cells; the networks are selected and reinforced by environmental stimuli; and these reinforced networks can then be said to "represent" the stimuli—e.g., the appearance of a predator—though no particular network of nerve cells exclusively represents any one set of stimuli. The environment does not directly "instruct" the brain; it does not imprint precise images in memory. Rather, working through our senses, the environment selects certain networks and reinforces the connections between them.[1]
Critical to this process of selection, in Changeux's view, is the brain's reward system: the pleasure response. Dopamine is part of a reward system that is important in human and animal behavior, and dopamine levels are elevated in the brain when we experience pleasure or well-being. Pleasure is associated both with the anticipation of activities essential to survival—for example, eating and sex—and with the activities themselves. Changeux describes one particularly telling experiment:
When a trained monkey succeeds in grasping a peanut hidden in a box, the inside of which it cannot see, the activity of dopamine neurons increases at precisely the moment when the animal recognizes the food with its fingers.
But opiates, alcohol, cannabinoids, nicotine, and other drugs can also increase the release of dopamine and subvert the normal function of the reward system. A rat given infusions of cocaine into the brain following the pressing of a bar will persist in pressing the bar repeatedly in preference to consuming food or water. Sugar, too, can be addictive. Indeed, the National Institutes of Health is now studying whether foods high in fat and sugar should be classified as addictive agents, in the same category as nicotine, alcohol, and cocaine.
In general, behaviors associated with pleasure are reinforced by the release of dopamine; as a result, the synaptic junctions of the associated neuronal networks are strengthened. And as they are strengthened, the changes in brain function often become permanent. A former cocaine addict who has been able to live without the drug for a decade may experience an irresistible need for cocaine when returning to a place whose cues evoke past drug-taking experiences. But the memories that are evoked are reconstructions:
Every evocation of memories is a reconstruction on the basis of physical traces stored in the brain in latent form, for example at the level of neurotransmitter receptors.
Instead of recalling the experiences of both pleasure-filled high and painful withdrawal, the addict's memories may be overwhelmed by the powerful neural connections previously created by the drug. Only if memory is a matter of reconstruction of latent physical traces, not direct recall of past events, Changeux argues, could these kind of drug-induced long-term compulsions occur.
In his book The Physiology of Truth, Changeux connects memory to the acquisition of knowledge and the testing of its validity, as is done in science in general. "We now find ourselves in a position," Changeux writes,
to sketch the outlines of a plausible interpretation of the neural bases of meaning. The naive view that the neural representation of a complex meaning—a yellow Renault, for example—is located in a single, hierarchically prominent nerve cell...has been found to be unjustified for the most part. It is generally accepted today that distinct populations of neurons in sen-sory, motor, associative, and other territories are linked as part of a distributed network...[which] mobilizes several distinct and functionally specific territories in a discrete manner, thus constituting a neural embodiment of meaning. Note that this assumption does not require that...anatomical connections be...reproducible across individual brains in every detail [in order to evoke memory], only that a map of functional relations be established.
In some ways Changeux's ideas are similar to Gerald Edelman's theory of neural Darwinism. For both Changeux and Edelman, Darwinian selection is an essential part of how the brain functions. And yet Edelman and Changeux have radically different views of what selective mechanisms in the brain imply about the nature of brain function, knowledge, memory, and consciousness. Our senses, in Edelman's view, are confronted by a chaotic, constantly changing world that has no labels. The brain must create meaning from that chaos. Edelman writes, in A Universe of Consciousness, his book with Giulio Tononi:
It is commonly assumed that memory involves the inscription and storage of information, but what is stored? Is it a coded message? When it is "read out" or recovered, is it unchanged? These questions point to the widespread assumption that what is stored is some kind of representation. [We take] the opposite viewpoint, consistent with a selectionist approach, that memory is nonrepresentational.[2]
While Changeux also considers selection to be essential to the formation of memory, he, as opposed to Edelman, believes that once a set of neuronal circuits have been selected to form a memory, they become part of a relatively stable structure that "can be conceived as a set of long-lasting global representations." Though "the precise patterns of connectivity in the network may vary from individual to individual," Changeux writes,
its functional relationships (or stabilized meanings) remain constant. In this way a "scale model" of external reality...is selected and stored in memory in the brain. Memory objects enjoy a genuine existence, then, as latent "forms" composed of stable neuronal traces.
Changeux says memories can be modified by the addition of new information, or "by preexisting knowledge or by the emotional resonance of actual memories of past experience."
In contrast to Changeux's account, Edelman, we believe, has a different and considerably deeper view of memory and what it tells us about the nature of meaning and brain function. Both Changeux and Edelman propose that during memory formation, our interactions with the world cause a Darwinian selection of neural circuits, much as the body, when invaded by a virus, "selects" the most potent antibodies from the enormous repertoire of antibodies made available by the body's immune system. However, the resulting memory is not, Edelman says, a representation of the outside world, any more than the antibody that has protected the body against an infecting virus is a representation of that virus. Yet the antibody can protect the body against a future attack by the virus, just as the neural circuits can contribute to memory recall. Instead, Edelman writes, memory is the ability to
repeat a mental or physical act after some time despite a changing context.... We stress repetition after some time in this definition because it is the ability to re-create an act separated by a certain duration from the original signal set that is characteristic of memory. And in mentioning a changing context, we pay heed to a key property of memory in the brain: that it is, in some sense, a form of constructive recategorization during ongoing experience, rather than a precise replication of a previous sequence of events.
For Edelman, then, memory is not a "small scale model of external reality," but a dynamic process that enables us to repeat a mental or physical act:
the key conclusion is that whatever its form, memory itself is a [property of a system]. It cannot be equated exclusively with circuitry, with synaptic changes, with biochemistry, with value constraints, or with behavioral dynamics. Instead, it is the dynamic result of the interactions of all these factors acting together, serving to select an output that repeats a performance or an act.
The overall characteristics of a particular performance may be similar to previous performance, but the ensembles of neurons underlying any two similar performances at different times can be and usually are different. This property ensures that one can repeat the same act, despite remarkable changes in background and context, with ongoing experience.
The validity of the respective approaches of Changeux and Edelman remains to be tested by further inquiry into brain function. The detailed neurophysiological processes involved are still largely unexplored.
In fact, "external reality" is a construction of the brain. Our senses are confronted by a chaotic, constantly changing world that has no labels, and the brain must make sense of that chaos. It is the brain's correlations of sensory information that create the knowledge we have about our surroundings, such as the sounds of words and music, the images we see in paintings and photographs, the colors we perceive: "perception is not merely a reflection of immediate input," Edelman and Tononi write, "but involves a construction or a comparison by the brain."
For example, contrary to our visual experience, there are no colors in the world, only electromagnetic waves of many frequencies. The brain compares the amount of light reflected in the long (red), middle (green), and short (blue) wavelengths, and from these comparisons creates the colors we see. The amount of light reflected by a particular surface—a table, for example— depends on the frequency and the intensity of the light hitting the surface; some surfaces reflect more short-wave frequencies, others more long-wave frequencies. If we could not compare the presence of these wavelengths and were aware of only the individual frequencies of light—each of which would be seen as gray, the darkness or lightness of each frequency depending on the intensity of the light hitting the surface—then the normally changing frequencies and intensities of daylight (as during sunrise, or when a cloud momentarily blocks out the sun) would create a confusing picture of changing grays. Our visual worlds are stabilized because the brain, through color perception, simplifies the environment by comparing the amounts of lightness and darkness in the different frequencies from moment to moment.[3]
The problem of representation, meaning, and memory is also illustrated by the case of a patient who has lost his arm in an accident. As is often the case, the brain creates a "phantom" limb in an apparent attempt to preserve a unified sense of self. For the patient, the phantom limb is painful. The brain knows there is no limb; pain is the consequence of the incoherence between what the brain "sees" (no arm) and the brain's "feeling" the presence of a phantom that it has created in its attempt to maintain a unified sense of self in continuity with the past. Such pain is not created by an external stimulus and cannot be eliminated by painkillers.
One famous case is that of a young man who had lost his hand in a motorcycle accident. In a therapeutic procedure devised by V.S. Ramachandran, and described in his book with Sandra Blakeslee, Phantoms in the Brain, the patient put his intact hand in one side of a box and "inserted" his phantom hand in the other side. As the illustration on this page shows, one section of the box had a vertical mirror, which showed a reflection of his intact hand. The patient observed in the mirror the image of his real hand, and was then asked to make similar movements with both "hands," which suggested to the brain real movement from the lost hand. Suddenly the pain disappeared. Though the young man was perfectly aware of the trick being played on him —the stump of his amputated arm was lying in one section of the box—the visual image overcame his sense of being tricked. Seeing is believing! Pain—the consequence of the incoherence between the brain's creation of a phantom limb and the visual realization that the limb does not exist—disappeared; what was seen (a hand in the mirror) matched what was felt (a phantom).
According to the Italian neurologist Angela Sirigu, who used videos instead of mirrors to perform a similar experiment,
It is the dissonance between the image of oneself and the damaged body, that is at the origin of the phantom pain. Seeing the damaged hand once again function-ing, reduces the dissonance even though the patient is aware of being tricked.
At one moment the patient experiences a painful phantom limb; at another he sees a mirror image of his intact hand and the pain disappears. This is only one of many neurological examples of what we might call the Dr. Jekyll and Mr. Hyde Syndrome: the patient in the experiment sees and remembers one world at certain times and a completely different world at other times.[4] The phantom limb is the brain's way of preserving a body image—a sense of self that is essential to all coherent brain activity. And as in the case of colors, the phantom limb suggests that what we see, hear, and feel are inventions of the brain—an integration of the past (the loss of the limb) and the present (a phantom that is essential for the brain's continuing to function "normally").
In general, every recollection refers not only to the remembered event or person or object but to the person who is remembering. The very essence of memory is subjective, not mechanical, reproduction; and essential to that subjective psychology is that every remembered image of a person, place, idea, or object inevitably contains, whether explicitly or implicitly, a basic reference to the person who is remembering.
Our conscious life is a constant flow, or integration, of an immediate past and the present—what Henri Bergson called le souvenir du présent (1908) and Edelman more recently called the remembered present (1989). Consciousness, in this view, is neither recalled representations nor the immediate present, but something different in kind (as colors are different in kind from the lightness and darkness of different reflected wavelengths).
The importance of body image and motor activity for perception, physical movement, and thought is suggested by the recent discovery of "mirror neurons" by Giacomo Rizzolatti and his colleagues. They observed that the neurons that fired when a monkey grasped an object also fired when the monkey watched a scientist grasp the same object. The monkey apparently understood the action of the experimenter because the activity within its brain was similar when the monkey was observing the experimenter and when the monkey was grasping the object. What was surprising was that the same neurons that produced "motor actions," i.e., actions involving muscular movement, were active when the monkey was perceiving those actions performed by others.
The "rigid divide," Rizzolatti and Corrado Sinigaglia write in their new book, Mirrors in the Brain,
between perceptive, motor, and cognitive processes is to a great extent artificial; not only does perception appear to be embedded in the dynamics of action, becoming much more composite than used to be thought in the past, but the acting brain is also and above all a brain that understands.
We can recognize and understand the actions of others because of the mirror neurons; as Rizzolatti and Sinigaglia write, this understanding "depends first of all on our motor neurons."[5] Our abilities to understand and react to the emotions of others may depend on the brain's ability to imitate the neuronal activity of the individual being observed.
When we see a friend crying, we may feel sympathy because the activity in our brain is similar to that in the brain of the person crying. We recognize disgust in another person through our own experience of the feeling of disgust and the associated neural activity.
Rizzolatti and Sinigaglia write:
our perceptions of the motor acts and emotive reactions of others appear to be united by a mirror mechanism that permits our brain to immediately understand what we are seeing, feeling, or imagining others to be doing, as it triggers the same neural structures... that are responsible for our own actions and emotions.
The nature of the brain's "representations"—if there is such a thing—of the world, the self, the past and present, remains puzzling, as the very different approaches we have described suggest: Changeux's view of "long-lasting global representations"; Edelman and Tononi's view of memory as constructive recategorizations, and Rizzolatti's stunning discovery of mirror neurons, suggesting that we know and understand others, to some extent, through neural imitation.
And as these differing views show, while we are still far from a full understanding of the nature of memory, perception, and meaning, it is nonetheless because of the work of scientists such as Changeux, Edelman, and Rizzolatti that we have a better grasp of the complexity of subjective experiences. Perhaps in the future, questions about higher brain functions will be better understood because of new genetic and neurophysiological discoveries and brain imaging. An unexpected scientific discovery can give us a new insight into something we thought we had always known: mirror neurons, Rizzolatti tells us, "show how strong and deeply rooted is the bond that ties us to others, or in other words, how bizarre it would be to conceive of an I without an us."
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Notes
[1] Neural circuits selected during memory formation may be strengthened by the addition of new neurotransmitter receptors to the synaptic junctions. This is called Long Term Potentiation (LTP). The weakening or elimination of circuits can lead to memory loss, which occurs normally with aging but is accelerated in neurodegenerative diseases such as Alzheimer's. In that disease, neurons in the hippocampus, a brain region that is important to memory function, as well as other neurons in the brain, lose their synapses and eventually die, leading to memory impairment. Despite extensive investigation, the cause of neuron death in Alzheimer's disease is not understood. (Some of the recent research on memory loss is mentioned by Sue Halpern in "Memory: Forgetting Is the New Normal," Time, May 8, 2008.)
[2] For further discussion see Israel Rosenfield, "Neural Darwinism: A New Approach to Memory and Perception," The New York Review, October 9, 1986, as well as The Invention of Memory (Basic Books, 1988).
[3] See Oliver Sacks and Robert Wasserman, "The Case of the Colorblind Painter," The New York Review, November 19, 1987.
[4] See Israel Rosenfield, L'étrange, le familier, l'oublié (Paris: Flammarion, 2005) for further discussion; and Reilly et al., "Persistent Hand Motor Commands in the Amputees' Brain," Brain (August 2006), for evidence that the brain is maintaining normal motor commands despite the loss of a limb.
[5] V.S. Ramachandran believes that mirror neurons might give us further clues to the nature of phantom limb pain. He has noted that phantom pain disappeared for ten or fifteen minutes when a patient was observing a volunteer rub her hand and he has suggested that the suppression of pain in such cases might involve the mirror neurons. However, the mechanism of the pain suppression is not clear.


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