A new publication answers centuries' old questions regarding the mechanism and function of humor, identifying the reason humor is common to all human societies, its fundamental role in the evolution of homo sapiens and its continuing importance in the cognitive development of infants.

Previous theories have only ever applied to a small proportion of all instances of humor, many of them stipulating necessary content or social conditions either in the humor itself or around the individual experiencing it. But this doesn't explain why an individual can laugh at something when no one else around them does, nor why two people can laugh at the same stimulus for different reasons.

Want to really store carbon? Get old ... and underwater. Researchers at the Missouri Tree Ring Laboratory in the Department of Forestry discovered that trees submerged in freshwater aquatic systems store carbon for thousands of years, a significantly longer period of time than in a forest, thus keeping carbon out of the atmosphere.

The team studied trees in northern Missouri, a geographically unique area with a high level of riparian forests (forests that have natural water flowing through them). They discovered submerged oak trees that were as old as 14,000 years, potentially some of the oldest discovered in the world. This carbon storage process is not just ancient; it continues even today as additional trees become submerged, according to Guyette.

"If a tree is submerged in water, its carbon will be stored for an average of 2,000 years," said Richard Guyette, director of the MU Tree Ring Lab and research associate professor of forestry in the School of Natural Resources in the College of Agriculture, Food and Natural Resources. "If a tree falls in a forest, that number is reduced to an average of 20 years, and in firewood, the carbon is only stored for one year."

Engineers working in optical communications bear more than a passing resemblance to dreamers chasing rainbows.

They may not wish literally to capture all the colors of the spectrum, but they do seek to control the rate at which light from across the spectrum moves through optical circuits.

This pursuit is daunting when those circuits contain dimensions measured in nanometers.

At the nanoscale, says Qiaoqiang Gan, a Ph.D. candidate in electrical engineering at Lehigh University in Bethlehem, Pa., engineers hoping to integrate optical structures with electronic chips face a dilemma.

A friend wonders what I think about this editorial by Chris Anderson, the editor of Wired. Anderson says “faced with massive data, this approach to science — hypothesize, model, test — is becoming obsolete.” Anderson confuses statistical models with scientific ones. As far as the content goes, I’m completely unconvinced. Anderson gives no examples of this approach to science being replaced by something else. For me, the larger lesson of the editorial is how different science is from engineering. Wired is mainly about engineering. I’m pretty sure Anderson has some grasp of the subject. Yet this editorial, which reads like something a humanities professor would write, shows that his understanding doesn’t extend to science. It reminds me why I didn’t want to be a doctor (which is like being an engineer.)

California and New York regulators have been in the news lately (such as here and here), with their attempts to crack down on the nascent direct-to-consumer genetic testing industry. These states argue that companies like 23andMe, Navigenics, and several others, are offering unproven and unlicensed clinical tests directly to consumers. Are the services offered by these companies clinical tests, subject to the normal regulations of other clinical tests? Should the government be able to stop you from getting your DNA sequenced?

The answer to the second question is a flat-out no. The government has no legitimate reason to prevent you from getting genotyped. The technology used by these personal genetics companies is very good - in the future, this technology will be cheaper and cover more variants in your genome, but what is available right now is very good. And there are reasonable non-clinical reasons to get yourself sequenced, out of sheer curiosity, or for genealogy purposes, for example. More importantly, this sequence data is a permanent resource for you. Although we may not have very good clinical tests for complex genetic diseases right now, we'll have them in the future, and any DNA sequencing you get done now will be suitable for these future analyses. Once you have your raw DNA data in hand, it's there if you need it in the future.

So, as things stand now, the genotyping serviced offered by 23andMe, DecodeMe, and Navigenics have enough non-clinical use to justify themselves, and these services should not be blocked by state regulators. But simply offering people DNA sequencing is one thing - making disease risk predictions is another.

Not many people think about what it's like to be a bat, but for those who do, it's enlightening and potentially groundbreaking for understanding aspects of the human brain and nervous system.

Cynthia Moss, a member of the Neuroscience and Cognitive Science program at the University of Maryland, College Park, Md., is one of few researchers who spend time trying to get into the heads of bats.

Her new research suggests there is more to studying bats than figuring out how they process sound to distinguish environments.
"For decades it's been recognized that a bat's voice produces sounds that give the bat information about the location of objects," says Moss. "We're now recognizing that every time a bat produces a sound there are changes in brain activity that may be important for scene analysis, sensorimotor control and spatial memory and navigation."

Every year thousands of doctors and scientists fly to meetings all over the world, but with climate change accelerating, can this type of travel be justified, two doctors debate the issue in this week's BMJ.

Flying across continents in great numbers to exchange information will soon become as outdated and unsuitable to the modern world as the fax machine and the horse-drawn carriage, writes Professor Malcolm Green, from Imperial College, London.

Driving less and low energy light bulbs can contribute a little to reducing our carbon footprint, but if doctors stop going to international conferences they could make a real difference and be seen to be taking the lead, he argues.

If you remember the early days of computers, you saw some marketing claims that seemed to make sense but quickly evaporated when reality hit - you could store all your recipes, for example, until you realized computers were as loud as a turbo jet and used almost as much energy so it was not wise to keep them on - so keep a box with some index cards in it was much better.

You may feel the same way about adding an invisible layer of nanomaterials to the bottom of a metal put just so you can boil water using a lot less energy. While this increase in efficiency could some day have a big impact on cooling computer chips, and reducing costs for industrial boiling applications, like those early computers, it's best to wait a while before getting rid of the tea kettle.

Bringing water to a boil, and the related phase change that transforms the liquid into vapor, requires an interface between the water and air. In the example of a pot of water, two such interfaces exist: at the top where the water meets air, and at the bottom where the water meets tiny pockets of air trapped in the microscale texture and imperfections on the surface of the pot. Even though most of the water inside of the pot has reached 100 degrees Celsius and is at boiling temperature, it cannot boil because it is surrounded by other water molecules and there is no interface — i.e., no air — present to facilitate a phase change.

AMSTERDAM, June 26 /PRNewswire/ --

- 43 Elsevier Journals Receive Top Category Rank; Journal Citations Grow 10 Percent; Lancet and Cell Each Increase and Retain Leadership Positions

Elsevier, the leading publisher of scientific, technical and medical information products and services, today announced highlights of its Journal Impact Factor performance in 2007. The 2007 Journal Citation Reports(c) published by ThomsonReuters, reports that 43 Elsevier journals ranked number one in their respective categories. In addition, total Elsevier journal citations grew by 10 percent (compared to an industry average of 8.9 percent).

Liver cancer is the third most common global cause of cancer death and a new study may be good news for drinkers and growers.

The large, prospective population-based study confirms an inverse relationship between coffee consumption and liver cancer risk. The study also found that higher levels of gamma-glutamyltransferase (GGT) in the blood were associated with an increased risk of developing the disease.

Researchers led by Gang Hu at the University of Helsinki set out to examine the associations between coffee consumption and serum GGT with the risk of liver cancer in a large prospective cohort. Residents of Finland drink more coffee per capita than the Japanese, Americans, Italians, and other Europeans, so Hu and colleagues studied 60,323 Finnish participants ages 25 to 74 who were cancer-free at baseline. The Finns were included in seven independent cross-sectional population surveys conducted between 1972 and 2002 and followed up through June 2006.