New Years Eve party tip

Cornell Professor Brian Wansink's study showed that people overpour into tall, thin glasses by 20 to 30 percent, compared with short, wide glasses, probably because of the vertical-horizontal optical illusion that people consistently perceive vertical lines as longer than horizontal ones of the same length. Photo credit: Jason Koski, Cornell University Photo High Resolution Image

Watching your alcohol intake? Use a taller glass. When pouring liquor this New Years Eve, people – even professional bartenders – will unintentionally pour 20 to 30 percent more into short, squat glasses than into tall, thin ones, according to a new Cornell University study. "Yet, people who pour into short, wide glasses consistently believe that they pour less than those who pour into tall, narrow glasses," said Brian Wansink, author of Marketing Nutrition and the John S. Dyson Professor of Marketing, Applied Economics and of Nutritional Science at Cornell. "And education, practice, concentration and experience don't correct the overpouring."

The reason for the difference, Wansink speculates, is the classic vertical-horizontal optical illusion: People consistently perceive vertical lines as longer than horizontal ones, even when the lines are the same length.

""People generally estimate tall glasses as holding more liquid than wide ones of the same volume," Wansink said. "They also focus their pouring attention on the height of the liquid they are pouring and insufficiently compensate for its width."

The study, by Wansink and Koert van Ittersum, assistant professor of marketing at Georgia Institute of Technology, is published in the current issue of the British Medical Journal.

In separate studies, the researchers asked 198 college students (43 percent female) of legal drinking age and 86 professional bartenders (with average six years experience on-the-job; 38 percent female) to pour "a shot" (1.5 oz.) of spirits into either short, wide tumblers or tall, thin highball glasses.

The college students consistently poured 30 percent more alcohol into short, wide glasses than into tall, slender glasses, and the bartenders poured 20 percent more.

When the researchers asked one group of the college students to practice 10 times before the actual experiment, those students still poured 26 percent more into short than into tall glasses. When the researchers asked one group of bartenders to "please take your time," those bartenders took twice as long to pour the drink, but still poured 20 percent more into short, wide glasses than into tall, slender glasses.

Advice for New Years party hosts and for partiers who don't want to unintentionally overdrink? "Use tall glasses or glasses with alcohol-level marks etched on them," Wansink suggested. For parents? Use tall, thin glasses when pouring soda but short, wide glasses for milk and other healthful drinks. ###

Writer: Susan S. Lang, Cornell University. Contact: Brian Wansink Wansink@Cornell.edu 607-254-6302 Cornell Food & Brand Lab

Technorati Tags: New Years Eve and Cornell University or professional bartenders and Nutritional Science or Direct Evidence That Bioclocks Work By Controlling Chromosome Coiling and Quantum Computers superconducting circuit and Nanotube-producing bacteria show manufacturing promise

Direct Evidence That Bioclocks Work By Controlling Chromosome Coiling

Caption: From left to right, Ximing Qin, Yao Xu, Mark Woelfle and Carl Johnson. Credit: Steve Green. Usage Restrictions: None. Related news release: Bioclocks work by controlling chromosome coiling

New research suggests that biological clocks influence the activity of a large number of genes by causing the chromosomes to coil tightly in the day and relax at night. There is a new twist on the question of how biological clocks work. In recent years, scientists have discovered that biological clocks help organize a dizzying array of biochemical processes in the body. Despite a number of hypotheses, exactly how the microscopic pacemakers in every cell in the body exert such a widespread influence has remained a mystery.

Now, a new study provides direct evidence that biological clocks can influence the activity of a large number of different genes in an ingenious fashion, simply by causing chromosomes to coil more tightly during the day and to relax at night.

“The idea that the whole genome is oscillating is really cool,” enthuses Vanderbilt Professor of Biological Sciences Carl Johnson, who headed the research that was published online Nov. 13 in the Proceedings of the National Academy of Sciences. “The fact that oscillations can act as a regulatory mechanism is telling us something important about how DNA works: It is something DNA jockeys really need to think about.”

Johnson’s team, which consisted of Senior Lecturer Mark A Woelfle, Assistant Research Professor Yao Xu and graduate student Ximing Qin, performed the study with cyanobacteria (blue-green algae), the simplest organism known to possess a biological clock. The chromosomes in cyanobacteria are organized in circular molecules of DNA. In their relaxed state, they form a single loop. But, within the cell, they are usually “supercoiled” into a series of small helical loops.

There are even two families of special enzymes, called gyrases and topoisomerases, whose function is coiling and uncoiling DNA.

The researchers focused on small, non-essential pieces of DNA in the cyanobacteria called plasmids that occur naturally in the cyanobacteria. Because a plasmid should behave in the same fashion as the larger and more unwieldy chromosome, the scientists consider it to be a good proxy of the behavior of the chromosome itself.

When the plasmid is relaxed, it is open and uncoiled and, when it is supercoiled, it is twisted into a smaller, more condensed state. So, the researchers used a standard method, called gel electrophoresis, to measure the extent of a plasmid’s supercoiling during different points in the day/night cycle. The researchers found that the plasmid’s size varies according to this cycle: The plasmid is smaller and more tightly wound during periods of light than they are during periods of darkness. They also found that this rhythmic condensation disappears when the cyanobacteria are kept in constant darkness.

“This is one of the first pieces of evidence that the biological clock exerts its effect on DNA structure through the coiling of the chromosome and that this, in turn, allows it to regulate all the genes in the organism,” says Woelfle.

Some cyanobacteria use their biological clocks to control two basic processes. During the day, they use photosynthesis to turn sunlight into chemical energy. During the night, they remove nitrogen from the atmosphere and incorporate it into a chemical compound that they can use to make proteins. According to the Johnson lab’s “oscilloid model,” the genes that are involved in photosynthesis should be located in regions of the chromosome that are “turned on” by the tighter coiling in the DNA during the day and “turned off” during the night when the DNA is more relaxed.

By the same token, the genes that are involved in nitrogen fixation should be located in regions of the chromosome that are “turned off” during the day when the DNA is tightly coiled and “turned on” during the night when it is more relaxed.

The researchers see no reason why the bioclocks in higher organisms, including humans, do not operate in a similar fashion. “This could be a universal theme that we are just starting to decipher,” says Woelfle.

The DNA in higher organisms is much larger than that in cyanobacteria and it is linear, not circular. Stretched end-to-end, the genome in a mammalian cell is about six feet long. In order to fit into a microscopic cell, the DNA must be tightly packed into a series of small coils, something like microscopic Slinkies. Previous studies have shown that in higher organisms between 5 to 10 percent of genes in the genome are controlled by the bioclock, compared to 100 percent of genes in the cyanobacteria. In the case of the higher organisms, the bioclock’s control is likely to be local rather than the global situation in cyanobacteria.

With a circular chromosome (as in cyanobacteria), twisting it at any point affects the entire molecule. When you twist a linear chromosome at a certain point, however, the effect only extends for a limited distance in either direction because the ends are not connected. That fits neatly with the idea that the bioclock’s influence on linear chromosomes is limited to certain specific regions, regions where the specific genes that it regulates are located.

The research was supported by the National Institute of General Medical Sciences.

By David F. Salisbury. Contact: David F. Salisbury david.salisbury@vanderbilt.edu 615-343-6803 Vanderbilt University and Exporation, Vanderbilt's Online Research Magazine

Technorati Tags: chromosome coiling and Bioclocks or Biological Sciences and Vanderbilt University or Bush radio address 12/22/07 full audio, text transcript and Northern Red-legged Frog (Rana aurora aurora) and Ultrafast optical shutter is switched entirely by laser light