Science and Reason: Selected readings 2/13/10

Interesting reading and news items.

These items are also bookmarked at my Diigo account.

Easy = True: One of the hottest topics in psychology today is something called “cognitive fluency.” Cognitive fluency is simply a measure of how easy it is to think about something, and it turns out that people prefer things that are easy to think about to those that are hard. On the face of it, it’s a rather intuitive idea. But psychologists are only beginning to uncover the surprising extent to which fluency guides our thinking, and in situations where we have no idea it is at work. [Boston.com, 1/31/10]
Mammogram Math: The panel of scientists advised that routine screening for asymptomatic women in their 40s was not warranted and that mammograms for women 50 or over should be given biennially rather than annually. The response was furious. Fortunately, both the panel’s concerns and the public’s reaction to its recommendations may be better understood by delving into the murky area between mathematics and psychology. [New York Times, 12/10/09]
A Deluge of Data Shapes a New Era in Computing: In a speech given just a few weeks before he was lost at sea off the California coast in January 2007, Jim Gray, a database software pioneer and a Microsoft researcher, sketched out an argument that computing was fundamentally transforming the practice of science. [New York Times, 12/14/09]
Earth-Like Planets May Be Made of Carbon: Other Earth-mass planets may be enormous water droplets, balls of nitrogen or lumps of iron. Name your favorite element or compound, and someone has imagined a planet made of it. The spectrum of possibilities depends largely on the ratio of carbon to oxygen. After hydrogen and helium, these are the most common elements in the universe, and in an embryonic planetary system they pair off to create carbon monoxide. The element that is in slight excess ends up dominating the planet’s chemistry. [Scientific American, 1/1/10]
People Share News Online That Inspires Awe, Researchers Find: Perhaps most of all, readers wanted to share articles that inspired awe, an emotion that the researchers investigated after noticing how many science articles made the list. In general, they found, 20 percent of articles that appeared on the Times home page made the list, but the rate rose to 30 percent for science articles. [New York Times, 2/8/10]
The Depressing News About Antidepressants: Yes, the drugs are effective, in that they lift depression in most patients. But that benefit is hardly more than what patients get when they, unknowingly and as part of a study, take a dummy pill—a placebo. As more and more scientists who study depression and the drugs that treat it are concluding, that suggests that antidepressants are basically expensive Tic Tacs. [Newsweek, 1/29/10]
Mystery Swirls Around 'Dark Stars': When the very first stars lit up, they may have been fueled by the dark matter that has long eluded scientists. These "dark stars," first born nearly 13 billion years ago, might still exist today. Although they would not shed any visible light, astronomers might detect these invisible giants - some 400 to 200,000 times wider than our sun and 500 to 1,000 times more massive. [Space.com, 12/21/09]
Researchers store working memory in brain slices: Even though we have a decent idea of how individual neurons work, scientists are still struggling to understand how these cells manage to store and convey information. A study published over the weekend by Nature Neuroscience describes how researchers were able to track the maintenance of short-term, working memories in the neurons of a rat brain and, in the process, managed to read and write individual bits into a brain slice. [Nobel Intent, 12/28/09]
Hormones in Concert: Multiple hormones act in concert to regulate blood sugar and food intake. The idea has already led to a new diabetes therapy; will it also yield new strategies for obesity? [The Scientist, 12/1/09]
New-found galaxies may be farthest back in time and space yet: By pushing the refurbished Hubble Space Telescope to its very limits as a cosmic time machine, astronomers have identified three galaxies that may hail from an era only a few hundred million years after the Big Bang. The faint galaxies may be the most distant starlit bodies known, each lying some 13.2 billion light-years from Earth. [Science News, 1/3/10]
Benford's Mathemagical Law: If you collected data on city sizes for the country you live in, and looked at all the first digits, you would find that many more cities have a population count starting with one, than cities with populations that begin with any other number as their first digit. You could also look at consumer price index development for the European Union, or a (long enough) time series for the Dow Jones Index, and you would find the same thing: More numbers start with 1, than start with 2, than start with 3, and so on. [Ingenious Monkey, 12/2/09]
Memories Glow Under the Microscope: How does memory work? What changes in the brain when we learn something? We don't know for sure. But two outstanding Nature papers have just provided an important piece of the puzzle, using a truly amazing technique which allowed them to examine the brain of a living, breathing mouse under the microscope. [Neuroskeptic, 12/8/09]
Black Holes, Brownian Motion: Black holes also undergo Brownian motion, and astronomers can use that fact to their advantage. Within most (if not all) galaxies is a supermassive black hole. These typically have a mass a hundred thousand to a billion times larger than our sun. They reside in the center of the galaxy, surrounded by a dense cluster of stars. Just as a dust-mote is knocked about by the tiny atoms surrounding it, the black hole is knocked about by the (relatively) tiny stars surrounding it. Obviously we can't observe this motion in real time, but its effect is clearly measurable. Black holes undergoing Brownian motion on a cosmic scale. [Upon Reflection, 12/7/09]
Stress Now, Mental Illness Later: The effects of stress can be felt acutely (i.e., in the short-term) or many years later (e.g., the average time span between onset of sexual abuse and the development of clinical depression is 11.5 years. This poses an interesting question: can the age at which one experience "stress" predict both the onset and type of mental illness? That's what Lupien et al. wanted to answer in an interesting paper that was published in Nature Reviews Neuroscience earlier this year. [The MacGuffin, 12/15/09]
Researchers Identify Genetic Variant Linked to Faster Biological Aging: Chronological age is very different from biological age—the condition of chromosomes after each cellular division—according to Nilesh Samani of the University of Leicester, co-author of a February 7 report published in Nature Genetics. Biological age, Samani says, is related to the length of telomeres—stretches of DNA at the ends of chromosomes, which protect these precious packages of genes from daily wear and tear. We're born with telomeres of a certain length, and these get shorter as our cells divide, resulting in aging, scientists think. [Scientific American, 2/8/10]
Cancer: 'Primitive' gene discovered: To find the causes for cancer, biochemists and developmental biologists at the University of Innsbruck, Austria, retraced the function of an important human cancer gene 600 million years back in time. For the first time, they have identified the oncogene myc in a fresh water polyp and they have shown that this oncogene has similar biochemical functions in ancestral metazoan and in humans. [Eurekalert.org, 2/11/10]
Tumors as ecosystems: What’s a tumor? In some ways, that’s a bad question (never mind the answer) because it implies that a tumor is a single thing. But we know that’s not true. A tumor, by the time we can detect it, is a collection of many cells, at least billions of them, and those cells are not all the same. [Mystery Rays from Outer Space, 2/3/10]