BOVINE BUBBLES

Dairy cows housed in “bovine bio-bubbles” are helping UC researchers get to the bottom of Bossie’s contribution to air pollution.

For the next two years Frank Mitloehner, a UC Cooperative Extension specialist in the Department of Animal Science, will monitor the Holstein heifers and measure emissions of ammonia, particulate matter or “fugitive dust,” and volatile organic compounds that give rise to ozone.

“This is the only controlled project like this in the country,” Mitloehner said. “We will be measuring nutrients fed to and excreted from cows and all the related emissions released into a closely monitored atmosphere.”

Concern over air quality in the San Joaquin Valley, among the worst in the country, prompted this unusual research project. The valley has a high concentration of dairy farms that add dust and air emissions to the atmosphere. Detailed data about the dairy industry’s role in air quality are needed to give the industry and state agencies current information for regulatory decisions.

The $600,000 study is funded by the State Water Resources Control Board and Merced County and has received matching funds from UC Davis.

Looking much like Quonset huts, Mitloehner’s four covered corrals each measure 70 by 40 feet and arch 15 feet high. Each pen will house 10 heifers (young cows that have never given birth) or 10 non-lactating adult cows, which typically make up more than half of a dairy’s herd.

In the first year of the project, Mitloehner’s team of graduate students and staff researchers will be investigating several methods to reduce dust, ammonia and volatile organic compounds.

Ammonia is of concern because it combines with nitrogen or sulfur oxides to create irritating, fine dust particles that pose health risks. Dust kicked up by the trampling of dried dairy or feedlot manure is another health concern because the tiny particles are a human respiratory hazard.

In the second year of the project, Mitloehner’s team will examine how various feed rations affect what wafts into the atmosphere.

The San Joaquin Valley Air Pollution Control District recently issued new rules that require dairies with more than 500 cows, and farmers with more than 100 contiguous acres of cropland, to implement conservation management practices to control dust by Dec. 31. A new state law, which took effect July 1, requires air permits for all agricultural operations whose emissions exceed a certain threshold.

“The emission factor that determines dairy emissions today is derived from a study that not only is critically outdated but did not measure volatile organic compounds at all,” Mitloehner says. “Nonetheless, this is how air-quality regulators are determining who requires a permit until better data are available.”

— John Stumbos

MATH MAGIC

When he wasn’t experimenting with lightning or overthrowing the British Empire, Benjamin Franklin found time to fool around with mathematics, inventing a variant of the magic square called Franklin squares. Now Maya Ahmed, a UC Davis mathematics graduate student, has come up with a way to construct both Franklin’s own squares and others of the same type. The methods could have applications in computer programming for business.

A regular magic square is a table of numbers in which any row, column or diagonal adds up to the same number. Mathematicians around the world have studied them for thousands of years.

They are classical, beautiful objects,” said Jésus De Loera, associate professor of mathematics and Ahmed’s thesis supervisor.

Franklin’s squares are similar, but instead of diagonals adding to the magic number, the bent diagonals (like a V from corner to center to adjacent corner) add to the magic number. The four corners and four center squares also add to the magic number.

Franklin himself created three such squares, two that are eight rows by eight columns and one of 16 by 16.

“No one knows how he did it,” Ahmed said. “They’re very hard to construct.”
Ahmed’s method turns what looks like an arithmetic problem into a geometry problem. The numbers in a Franklin square can be described by a series of equations—127 equations for an eight-by-eight square. Those equations also describe a cone-shaped object in multiple (more than three) dimensions. That yields the basic elements of a Franklin square.

Using this method, Ahmed could both reconstruct Franklin’s three original squares and create new ones that obey the same rules. She was also able to work out the maximum possible number of eight-by-eight Franklin squares: just over 228 trillion.

Franklin regarded his squares as “incapable of useful application.” But Ahmed’s methods can also be used to find whole-number solutions to problems of linear equations. An example would be scheduling aircraft and crew members for an airline, De Loera said.

The paper is published in the May issue of the American Mathematical Monthly.

— Andy Fell

The price isn’t always right, warn UC Davis researchers: Some generic products are actually superior in quality to comparable but costlier name brands.

Using data from Consumer Reports (1990–1997), marketing experts Eitan Gerstner and Prasad Naik of the Graduate School of Management and Eidan Apelbaum of Yahoo! Inc., Ph.D. ’00, compared the quality of supermarket name brands and their generic, or store brand, counterparts. Their findings just might change the way you shop. Looking at 78 product types—from strawberry yogurt to garbage bags—they found generic brands better than name brands 25 percent of the time.

“Generic brands compete with this ‘poor quality’ notion,” Naik said. “They’re viewed as not good enough. But you can venture to try generic and get your money’s worth.”

Among those generic products that surpassed name brands in quality include cheese, hot dogs, tea, tuna, potato chips and fabric softener.

The findings, which appeared in the Journal of Product & Brand Management, illustrate the confidence consumers place in name brands.

“[The study] shows that branding can give substantial returns,” Naik said. “What we find is, even when the quality is poor, national labels can charge up to 28 percent more than private labels.”

And even when the quality is equal, the study notes, name brands enjoy a 37 percent price premium over store brands.

Generic labels have long been affordable alternatives to name brands. But the stigma of “buying generic” is wearing off, and in order to compete with diverse store brands, major companies have now begun producing generic versions of their own products.

In Naik’s view, the $500 billion that companies spend annually on domestic advertising is critical not so much to lure new consumers, but to maintain or improve a name brand’s cultural image.

“So long as companies like Coca-Cola or BMW are cultural symbols, they can charge more than their quality merits,” he said.

— Zachary Amendt