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Science Sunday; Genetic Drift, Placebos and Pot…and Questionable models..

Evolution the biochemists seem to be big on genetic drift as a major factor in evolution. Here is one article that talks about how genetic drift (observed at the organic chemistry level) affects human complexity. It makes us what we are, but might bode ill for our long term future as a species.

You want transitional forms? How about a reptile that makes a true placenta?

Science and Medicine
How about a cloned human embryo making a working stem cell? Of course, this is a very early result.

Why do placebos work? Evidently they activate the same receptor that marijuana does.

Earth’s History: a comet with water with similar chemical composition to the earth’s ocean was found. So is this how the earth got its water?

Statistics
Evidently, doing PSA readings of asymptomatic men do NOT save lives; the number of false positives cause more harm than is offset by the early detection benefits.

The draft recommendation, by the United States Preventive Services Task Force and due for official release next week, is based on the results of five well-controlled clinical trials and could substantially change the care given to men 50 and older. There are 44 million such men in the United States, and 33 million of them have already had a P.S.A. test — sometimes without their knowledge — during routine physicals.

The task force’s recommendations are followed by most medical groups. Two years ago the task force recommended that women in their 40s should no longer get routine mammograms, setting off a firestorm of controversy. The recommendation to avoid the P.S.A. test is even more forceful and applies to healthy men of all ages.

“Unfortunately, the evidence now shows that this test does not save men’s lives,” said Dr. Virginia Moyer, a professor of pediatrics at Baylor College of Medicine and chairwoman of the task force. “This test cannot tell the difference between cancers that will and will not affect a man during his natural lifetime. We need to find one that does.”

Of course, such early testing is big business, so of course they will fight this. And, of course, the general public really doesn’t understand how a large number of false positives can render such an early detection test not only useless, but potentially harmful (in terms of unnecessary treatments and anxiety).

Speaking of shaky statistics, we see things like this in politics:

John King: The data is just simply not good for the president. And then on top of that, that’s looking backward on the data we already know, today markets are talking about a bear market, financial markets don’t look good, the housing market don’t look good, the president can’t look out at the horizon and see anything to be optimistic about, can he?

Fareed Zakaria: It looks pretty grim. There’s a famous model that was designed by a professor in economic at Yale, Ray Fair, which predicts outcome of presidential elections. He’s never been wrong in 40 years. And the basic inputs are economic growth, unemployment, inflation you know your basic economic data that the theory is that the campaign itself is actually irrelevant, that you give me the economic data and I will tell you whether the incumbent will get re-elected. Well, if you use those kinds of models and those numbers, the situation looks very tough for the president.

Oh, so you accuse me of putting my head in the sand because this model doesn’t show what I want it to show? Here is an example that goes the other way:

Allan J. Lichtman, a presidential historian at American University, has issued a prediction that, given an economy still teetering on the brink of recession and President Obama’s 40 percent approval ratings, looks awfully bold.

“Even if I am being conservative, I don’t see how Obama can lose,” Mr. Lichtman told Paul Bedard of U.S. News & World Report.

Mr. Lichtman’s prediction is based on his 1984 book “The Keys to the White House”. The book cites 13 factors that can work for or against the party of the incumbent president. If at least eight of the 13 keys are scored in favor of the incumbent, he will win the election, Mr. Lichtman says; if he gets seven or fewer, he will not.

The book claims to have called the winner of the popular vote correctly in each election since 1860. (It would not have gotten the winner of the Electoral College right in 1876, 1888 or 2000, when the popular and electoral vote split.) That’s 38 elections in a row! Superficially quite impressive.

But ‘superficial’ is the crucial term here. There are several problems with this model, and its results should be taken with a grain of salt.

So one of these “foolproof” models will be wrong.:)

What is going on? Think of it this way: suppose you had thousands of chimps flipping coins to predict each election for the past N elections. Given enough chimps, there will be a few “super chimps” that got every call right, so far. Would we view these chimps as gurus?

October 9, 2011 Posted by | biology, evolution, health, health care, nature, science, space, statistics, stem cells | Leave a comment

27 August 2010 posts (pm)

Humor (and education oriented)

What NOT to do with powerpoint

Note: I don’t use it, but I still found it to be hilarious.

Humor This is one protest that I could get “behind”. :)

Books: here is Huffington Post’s take on what is being read in public. Personally, I tend to choose books that are easier to read when I am in public spaces (don’t need to concentrate that hard). But I also choose “statement” books that say “I like evolution, atheism, politics, Obama, etc.” so as to strike up a favorable chance conversation. :)

Politics President Barack Obama is on the wrong side of history here (re: gay marriage). I hope that he changes his mind.

Also, on the economy: Robert Reich talks about how the Democrats ought to sell their plans and why it should be sold in that way:

So instead of playing defense, Democrats should go on the attack.

Accuse Republicans of being shills for the rich.

And don’t stop there. Do tax jujitsu. In addition to ending the Bush tax cut for the rich, put forward another proposal for growing the economy that cuts taxes on lower-income Americans.

Democrats should propose eliminating payroll taxes on the first $20,000 of income, and making up the revenue loss by applying payroll taxes to incomes above $250,000.

This would give the economy an immediate boost by adding to the paychecks of just about every working American. 80 percent of Americans pay more in payroll taxes than they do in income taxes. And because lower-income people would get most of the benefit, it’s likely to be spent. [...]

Call it the People’s Tax Cut, and let Republicans explain why they’re against it.

Mathematics
Here is an article which describes the use of mathematics in making heart stints.

Science
Planet orbits: in other solar systems, the orbits aren’t always stable.

Cells: liver cells have been created from skin cells by British scientists:

British scientists have grown liver cells out of stem cells from human skin, boosting hopes that healthy cells can be transplanted into organs to repair damage from diseases like cirrhosis and cancer, according to new findings.

Cambridge University researchers took skin biopsies from seven patients suffering from various hereditary liver diseases, and from three healthy patients, “reprogramming” the skin samples into stem cells which can effectively become any tissue in the body.

For the first time, such cells were used to mimic a range of liver diseases, according to the findings published in Wednesday’s Journal of Clinical Investigation.

Growing liver cells in a laboratory is particularly difficult.

By replicating such cells in diseased livers, and replicating the healthy cells from a control group, researchers can not only determine precisely what is happening in the diseased cell, but also test the effectiveness of new therapies to treat diseases.

Principal investigator of the research Ludovic Vallier, of the MRC Centre for Stem Cell Biology and Regenerative Medicine at Cambridge, described the work as “an important step towards delivering the clinical promises of stem cells.”

World Events
No one seems to care that much about Pakistan’s trouble. No, this isn’t quite the reason. But here is one conjecture as to why:

Pakistan is a country that no one quite gets completely, but apparently everybody knows enough about to be an expert. If you’re a nuclear proliferation expert, suddenly you’re an expert on Pakistan. If you’re terrorism expert, ditto: expert on Pakistan. India expert? Pakistan, too then. Of South Asian origin of any kind at a think-tank, university, or newspaper? Expert on Pakistan. Angry that your parents sent you to the wrong madrassa when you were young? Expert on Pakistan.

This unique stock of global expertise on Pakistan naturally generates a scary picture. Between our fear of terrorism, nervousness about a Muslim country with a nuclear weapon, and global discomfort with an intelligence service that seems to do whatever it wants (rather than what we want it to do), Pakistan makes the world, and Americans in particular, extremely uncomfortable. In a 2008 Gallup poll of Americans, only Afghanistan, Iraq, the Palestinian Authority, North Korea, and Iran were less popular than Pakistan.

The net result of Pakistan’s own sins, and a global media that is gaga over India, is that Pakistan is always the bad guy. You’d be hard pressed to find a news story anywhere that celebrates the country’s incredible scenery, diversity, food, unique brand of Islam, evolving and exciting musical tradition, or even its arresting array of sporting talent, though all those things are present in abundance.

How bad is it? Well, in 2007, when the Pakistani cricket team’s national coach, an Englishman named Bob Woolmer, was found dead in his hotel room, the first instinct of the international press was that a Pakistani team member must have killed him. This is the story of modern day Pakistan.

Contrary to what many Pakistani conspiracy theorists believe, the suspicion and contempt with which the country is seen with is not deliberate or carefully calculated. It’s just how things pan out when you are the perennial bad boy in a neighborhood that everyone wishes could be transformed into Scandinavia — because after 9/11, the world cannot afford a dysfunctional ghetto in South and Central Asia anymore. Or so goes the paternalist doctrine.

It is bad enough that the Pakistani elite don’t seem eager to cooperate with this agenda of transformation; now, nature also seems to be set against it. The floods in Pakistan are the third major humanitarian crisis to afflict the country in recent years. The 2005 earthquake and the massive internal displacement of Pakistanis from Swat and the FATA region in 2009 were well-managed disasters, according to many international aid workers. While international support was valuable in mitigating the effects of those disasters, most experts agree that it was Pakistanis, both in government and civil society, that did the heavy lifting.

August 27, 2010 Posted by | 2010 election, astronomy, atheism, Barack Obama, biology, civil liberties, Democrats, education, evolution, health, mathematics, nature, obama, political/social, politics, politics/social, science, Spineless Democrats, stem cells, technology, world events | Leave a comment

   

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