Author Archives: curiouscat

Correlation is Not Causation

People born under the astrological sign of Leo are 15% more likely to be admitted to hospital with gastric bleeding than those born under the other 11 signs. Sagittarians are 38% more likely than others to land up there because of a broken arm. Those are the conclusions that many medical researchers would be forced to make from a set of data presented to the American Association for the Advancement of Science by Peter Austin of the Institute for Clinical Evaluative Sciences in Toronto. At least, they would be forced to draw them if they applied the lax statistical methods of their own work to the records of hospital admissions in Ontario, Canada, used by Dr Austin.

Dr Austin, of course, does not draw those conclusions. His point was to shock medical researchers into using better statistics, because the ones they routinely employ today run the risk of identifying relationships when, in fact, there are none. He also wanted to explain why so many health claims that look important when they are first made are not substantiated in later studies.

As I said in, Seeing Patterns Where None Exists: “Page 8 of Statistics for Experimenters by George Box, William Hunter (my father) and Stu Hunter (no relation) shows a graph of the population (of people) versus the number of storks which shows a high correlation. “Although in this example few would be led to hypothesize that the increase in the number of storks caused the observed increase in population, investigators are sometimes guilty of this kind of mistake in other contexts.'”

Nanoparticles to Battle Cancer

photo of Todd Harris, Sangeeta Bhatia and Geoffrey von Maltzahn

Team develops nanoparticles to battle cancer:

One solution already under way involves using nanoparticles for cancer imaging. By slipping through tiny gaps that exist in fast-growing tumor blood vessels and then sticking together, the particles create masses with enough of a magnetic signal to be detectable by a magnetic resonance imaging (MRI) machine. “This might allow for noninvasive imaging of fast-growing cancer ‘hot spots’ in tumors,” said Bhatia. The team will continue this research by testing the imaging capabilities in animal models.

Another solution, described in the Jan. 16 issue of the Proceedings of the National Academy of Sciences, is a novel “homing” nanoparticle that mimics blood platelets. Platelets flow freely in the blood and act only when needed, by keying in on injured blood vessels and accumulating there to form clots. Similarly, these new nanoparticles key in on a unique feature of tumor blood vessels.

Ruoslahti had identified that the lining of tumor vessels contains a meshwork of clotted plasma proteins not found in other tissues. He also identified a peptide that binds to this meshwork. By attaching this peptide to nanoparticles, the team created a particle that targets tumors but not other tissues. When injected into the bloodstream of mice with tumors, the peptide sticks to the tumor’s clotted mesh.

Photo by Donna Coveney, from related press release: MIT nanoparticles may help detect, treat tumors

Micro RNA Editing

What separates us from the worms by Tom Avril (bozos broke the link, poor usability, so I removed it):

RNA editing is thought to be just one way that humans get more out of their 30,000 genes than, say, a fruit fly does with 13,600 or a roundworm does with 19,100. Those creatures have more primitive editing machinery, said the paper’s senior author, Kazuko Nishikura of Philadelphia’s Wistar Institute.

And they have much less of what is sometimes misleadingly called “junk” DNA – a region of the genome that does not produce proteins but nevertheless appears to play a key role in the diversity of life. The new paper is one of numerous recent finds in the booming field of RNA research. In the early days of genetic study, RNA was seen basically as a messenger for its cousin, DNA, carrying instructions to direct the manufacture of proteins.

But other kinds of RNA have since been discovered, including some that regulate or turn off certain genes, playing a role in embryonic development and – when things go awry – in diseases such as cancer. Last year’s Nobel Prize in medicine was awarded to scientists who pioneered a related field called RNA interference. And RNA is now thought to be even older than DNA, with some saying it served as the genetic blueprint for the earliest forms of life.

Communication Emergence in Robots

Evolving Robotspeak by Carl Zimmer:

At first the robots just flashed their lights at random. But over time things changed. In the trials with relatives undergoing colony selection, twelve out of the twenty lines began to turn on the blue light when they reached the food. The light attracted the other robots, bringing them quickly to the food. The other eight lines evolved the opposite strategy. They turned blue when they hit the poison, and the other robots responded to the light by heading away.

Two separate communication systems had evolved, each benefiting the entire colony. By communicating, the robots also raised their score by 14%. Here’s a movie showing six of these chit-chatting robots finding a meal.

Related: The original paper, Evolutionary Conditions for the Emergence of Communication in Robots (pdf) by Dario Floreano, Sara Mitri, Stephane Magnenat and Laurent Keller – more robot related posts

Car Elevator (for parking)

Interesting photos of a NYC parking garage with elevators and the looks of a fancy mall not a garage. Cars are driven onto a palet and then the automated systems take it from there. Parking as a Destination:

The project is the work of AutoMotion Parking Systems, the American subsidiary of Stolzer Parkhaus of Strassburg, Germany. Stolzer Parkhaus has built 28 automated garages in 11 countries since its first, in Kronach, Germany, in 1996. The software and hardware that moves the cars around in the garages were adapted from systems that store materials in warehouses.
…
“Lasers check that the car is aligned,” Mr. Milstein said, and determines that it is not one of the trucks or S.U.V.’s too big for the garage. The driver locks the car, takes the keys and picks up an electronic card from a nearby machine. A large door closes behind the car; motion detectors ensure that no children or pets are left behind.

Then the pallet holding the car slides below ground level, into two subterranean floors of storage. “It’s simple — park, swipe and leave,” Mr. Milstein said. The returning driver pays — using a credit card at a machine, or handing cash to the human “parking concierge” in a booth. The machinery retrieves the pallet holding the car, which rises to ground level, pointing toward the exit. You unlock the doors and drive away.

“You get your car in under three minutes,” Mr. Milstein promises. “It’s as easy as an A.T.M. or E-ZPass.” Rates will be comparable to conventional parking in Manhattan, he said, about $400 a month. For the driver, the advantages of an automated system go beyond convenience and speed. The car remains untouched and unopened, and with the parking area ostensibly off limits.

Engineering is cool. Related: The High Cost of Free Parking

Wave Energy

Orkney to get ‘biggest’ wave farm:

Of the Pelamis scheme, he said: “This will be the world’s biggest commercial wave project – significantly bigger than the major Portuguese scheme. “Scotland has the potential to generate a quarter of Europe’s marine energy and kick-starting the sector is vital if we are to create a significant industry based in Scotland and meet our long-term renewables targets.”

Mr Stephen said the industry had the potential to create thousands of jobs and attract millions of pounds of investment. Scottish Power’s director of renewables, Keith Anderson, said: “This is a massive step forward. “It will be a test of the actual devices that will be used commercially and, if successful, should help propel Scotland into the forefront of marine energy throughout the world.”

Savanna Chimpanzees Hunt with Tools

Savanna Chimpanzees, Pan troglodytes verus, Hunt with Tools by Jill D. Pruetz and Paco Bertolani:

Broken link removed. See updated post: Chimpanzees Use Spears to Hunt Bush Babies

Although tool use is known to occur in species ranging from naked mole rats to owls, chimpanzees are the most accomplished tool users. The modification and use of tools during hunting, however, is still considered to be a uniquely human trait among primates. Here, we report the first account of habitual tool use during vertebrate hunting by nonhumans. At the Fongoli site in Senegal, we observed ten different chimpanzees use tools to hunt prosimian prey in 22 bouts. This includes immature chimpanzees and females, members of age-sex classes not normally characterized by extensive hunting behavior. Chimpanzees made 26 different tools, and we were able to recover and analyze 12 of these.

Stimulate Innovation

What if America Had an Innovation Czar?, good ideas from Keven Kelly:

1. More large prizes, like the Grand Challenger, for specific results. Cheap, effective, popular. The best Mars rover gets sent to Mars, etc.
2. Reform patent law, to reflect reality of current conditions (no submarine patents, etc.).
3. Mandate science fairs in high schools, the secret sauces for American innovation.
4. Open-source scientific literature.

Missing laptop found in ET hunt

Missing laptop found in ET hunt:

Kimberly was more enamored with Melin’s detective work.

“I always knew that a geek would make a great husband,” she said. “He always backed up all my data, but this topped it all. It became like `Mission: Impossible’ for him, looking for hard evidence for the cops to use. … He’s a genius – my hero.”
…
One of the computers on which Melin installed SETI(at)home is his wife’s laptop, which was stolen from the couple’s Minneapolis home Jan. 1.

Annoyed – and alarmed that someone could delete the screenplays and novels that his wife, Melinda Kimberly, was writing – Melin monitored the SETI(at)home database to see if the stolen laptop would “talk” to the Berkeley servers. Indeed, the laptop checked in three times within a week, and Melin sent the IP addresses to the Minneapolis Police Department.

Online Mathematics Textbooks

Online Mathematics Textbooks:

The writing of textbooks and making them freely available on the web is an idea whose time has arrived. Most college mathematics textbooks attempt to be all things to all people and, as a result, are much too big and expensive. This perhaps made some sense when these books were rather expensive to produce and distribute–but this time has passed.

A few years ago when I first posted a list of mathematics textbooks freely available on line, there existed only a handful of such books. Now there are many.

Including: Calculus by Gilbert Strang – Linear Algebra, Infinite Dimensions, and Maple by James Herod – Euclid’s Elements – Information Theory, Inference, and Learning Algorithms by David J. C. MacKay