February 2, 2009
The news media uncovered a variety of newsworthy topics at the 2009 Joint Mathematics Meetings, which were held in Washington, D.C., in early January.
Slate writer Chris Wilson investigated the question, "Can a bunch of mathematicians make government more representative?"
Wilson covered a special session on the value and use of political redistricting algorithms. Speakers included Daniel H. Ullman of George Washington University, Richard Pildes of New York University’s Law School, Micah Altman of Harvard University, Michael P. McDonald of George Mason University, Nathaniel Alfred Persily of Columbia University, James M. Snyder of the Massachusetts Institute of Technology, and Christopher P. Chambers and Alan D. Miller of the California Institute of Technology.
In the end, Wilson asked, "Why is an algorithmic solution for congressional redistricting such a pipe dream?"
"In part it's because it is surprisingly hard to define, or at least reduce to a set of rules, what a 'gerrymandered district' is," Wilson concluded. "Writing a formula for drawing districts requires us to define how funny-looking is too funny looking."
Ullman described one school of thought on the question. "The idea is that circles are the best shape for districts," he said. "Unfortunately, they don't tessellate well."
Patrick Berry of Science News headlined two items. In an article titled "Mathematicians Show How Beetles Can Share a Niche," Berry described a new mathematical model demonstrating that two competing species might actually coexist. Placing two species of flour beetle in the same jar of flour needn't always result in one species driving the other to extinction, as ecologists had thought.
"I think it opens some questions about this dogmatic view in ecology," said University of Arizona mathematician Jim Cushing, coauthor of the study. "It reopens the issue of what you consider a niche to be." Cushing and his colleagues presented the paper "Evolutionary Reversals in Competitive Interactions: Experimental Occurrences and Model Explanations Using Darwinian Dynamics" at the Joint Mathematics Meetings.
"What makes this work very, very exciting is the assumption was that if you start with equal conditions, you will always get one species outcompeting the other," Joel Brown of the University of Illinois, Chicago commented in Science News. "They're showing how just a tiny bit of evolution might actually explain the discrepancy."
Berry’s second article, titled "Calculating the Geography of Crime," dealt with the idea of combining crime records, geography, and other data into mathematical tools that could better and more quickly pinpoint serial criminals.
In research by Mike O'Leary of Towson University in Maryland, the idea is that, using information about the layout of a city, such as the location of similar crimes during the past few years, new mathematical tools could improve estimates of where a criminal lives based on where he or she commits crimes.
The "profiling problem in criminology is to determine a search area for an offender based on knowledge of the offender's crime locations," O'Leary said. His mathematical approach, described in the paper "Determining an Optimal Search Area for a Serial Criminal," incorporates "geographic and demographic features that influence the selection of a crime site" using Bayesian methods to generate more accurate predictions.
O'Leary's methods have "added some insights into the mathematics that previously we were struggling with," commented crime analyst and researcher Ned Levine of Houston. "He's really cleaning up the mathematics."
Writer Julie Rehmeyer was also at the meetings and reported on the mathematical art exhibition in her Science News column "When Art and Math Collide."
Roberta Kwok, writing for Nature, came up with this item: "Fighting Cholera by the Numbers."
"A new mathematical model could help to determine the best strategy for controlling outbreaks of cholera," Kwok wrote. The model "calculates which combination of vaccination, sanitation and antibiotic treatment levels will most effectively reduce the number of lives lost and the cost of intervention."
The model was developed by Rachael L.Miller of the University of Tennessee and her colleagues and described in the paper "Optimal intervention strategies for a cholera outbreak."
The model, a set of equations describing the likely spread of cholera, takes into account the infectiousness of the bacterium—it is more likely to cause disease when it is first shed—and the distinction between symptomatic and asymptomatic patients. The model predicts the extent and length of treatment, and suggests that vaccination and sanitation should last for three weeks.
The team, Kwok wrote, "introduced equations to determine the best, most cost-effective intervention schedule."
The idea sounds "fascinating," Rita Colwell of the University of Maryland commented. "It allows [epidemiology] to be far more quantitative and far more locale-specific than it has been in the past," she said.
Still, "there is a lot of work that needs to be done to fine-tune the parameters before it's something we're going to want to use as a practical tool," observed Glenn Morris of the University of Florida, who has worked with the Tennessee team. "But it's a start."
For additional news media reports from the meetings, see "Science Magazine Samples the 2009 Joint Mathematics Meetings." Other JMM highlights can be found at http://www.ams.org/ams/jmm09-highlights.html.
Source: Slate, Jan. 13, 2009; Science News, Jan. 31, 2009; Nature, Jan. 9, 2009.
For Barry Cipra's highlights from Science Magazine, click here.