ASU News - Science

ASU, Notre Dame to play football In Texas

ckussala — Thu, 08 May 2008 09:47:56 -0600

Arizona State University and Notre Dame have completed an agreement for a college football game to be played in Arlington, Texas, on October 5, 2013, Vice President for University Athletics Lisa Love announced Thursday. The game will be played at the yet-to-be-completed Dallas Cowboys Stadium. It is currently under construction and will open in the summer of 2009. With a capacity of 80,000 fans, it will be home to Super Bowl XLV following the 2011 NFL season as well as the annual AT&T Cotton Bowl.

The contest is one of a series of future off-site "home" games for the Fighting Irish over the next decade.

"We are excited to participate in this unique college football event in the new, state-of-the-art, stadium the Dallas Cowboys are building in Arlington," says Love. "We believe this will be a magnificent game for our fans and alumni. Our coaching staff recruits the state of Texas and this will only serve to assist in that area."

The Cowboys and the AT&T Cotton Bowl will combine to manage and market the game. ASU will receive an allotment of tickets for the game. NBC Sports will have the live television rights to the game, as with other Notre Dame home games.

ASU and Notre Dame already have an existing home/home series schedule for October 25, 2014, in Tempe and for September 16, 2017, in South Bend.

ASU and Notre Dame have met twice previously, with the Fighting Irish winning 28-9 in Tempe in 1998 and 48-17 in South Bend in 1999.

Pair elected to National Academy of Sciences

chughes3 — Tue, 29 Apr 2008 17:24:44 -0600

Two Arizona State University professors – Edward Prescott, Regents’ Professor and Nobel Laureate, and Luc Anselin, founding director of the School of Geographical Sciences – have been elected to the National Academy of Sciences. They join eight other ASU faculty members in the Academy, a Washington, D.C.-based organization that advises the federal government on matters of science or technology.

Prescott, who joined ASU in 2003 and is the W. P. Carey Chair of Economics in the W. P. Carey School of Business, is a senior monetary advisor at the Minneapolis Federal Reserve Bank. He was awarded the 2004 Nobel Prize in economic sciences, being lauded for a lifetime of original thinking that has addressed some of the most important long-standing questions in macroeconomics. He shared the prize with Finn Kydland.

Prescott’s work on business cycles has recast the way economists think about economic fluctuations, arguing that they represent the optimal response of the economy to various shocks. He also is known for his seminal work in policy analysis, economic development, general equilibrium theory and finance.

“I am honored to be elected to the National Academy of Science. I think it is an indicator of the success that ASU economics is having,” says Prescott. “It is a pleasure to work with the students here, including not only the graduate students, but the honors undergraduates I teach as well. I owe my election to my students who I have learned so much from, and to a number of collaborators.”

Anselin, who joined ASU last July, is one of the principal developers of the field of spatial econometrics and is best known for his book “Spatial Econometrics” and his development of the applications SpaceStat and GeoDa.

Anselin also serves as director of the GeoDa Center for Geospatial Analysis and Computation, a new research unit in ASU’s College of Liberal Arts and Sciences devoted to the development, implementation and application of state-of-the-art methods of geospatial analysis to policy issues in the social and environmental sciences.

“I think this is fantastic and an important recognition of the contribution of spatial thinking and spatial analysis to science. It also means that the School of Geographical Sciences becomes one of the very few geography units in the U.S. where there are two members of NAS among the faculty,” Anselin says. NAS member Billie Lee Turner, a national leader in sustainability science, recently joined ASU as the Gilbert F. White Chair in Environment and Society in the School of Geographical Sciences.

"On behalf of the entire ASU community I congratulate Professors Luc Anselin and Ed Prescott on this greatly deserved honor," says ASU President Michael M. Crow. "The scholarship of ASU's faculty and students has been repeatedly recognized by honors, awards, fellowships and grants. Election to the National Academy of Sciences is one of the greatest distinctions that any scholar can achieve."

Prescott and Anselin were among 72 new members who were elected April 29 to the National Academy of Sciences in recognition of their distinguished and continuing achievements in original research. Those new members bring the total number of active members to 2,041.

Other ASU faculty members who are NAS members include Charles Arntzen, Jane Buikstra, Roy Curtiss, Bert Hoelldobler, Elinor Ostrom, John Rowell, V. Kerry Smith.

ASU contest gives kids chance to interview scientists

mcoulomb — Tue, 29 Apr 2008 15:49:00 -0600

Arizona State University doctoral student Rebecca Clark bends the neck of a flexible lamp to illuminate a wide plain of dirt captured between two panes of glass, while three. Phoenix elementary students peer closely to see that the soil has been organized into a branching array of chambers by some very busy leaf-cutter ants.

Around the four, on every available surface are trays, experimental set ups, containing colonies of leaf-cutters and sap-sippers; big-headed ants and night ants. Of special interest: predatory, jumping ants from India.

“Excellent,” Taylor bursts out, then the barrage of questions from the trio of young students start: “Are all ants female? Is that a garbage dump? What is that fuzzy stuff?"

"This is so much fun,” Clark beams. “I love the questions.”

The inquisitors are third-graders Taylor Cheatham and Itzany Mendez, and fifth-grader Brian Varela from Paul Laurence Dunbar Elementary School. That these students are both curious and articulate comes as no surprise to the accompanying adults, their parents, teachers, ASU graduate students, and the host of this excursion, Charles Kazilek. The three are the winners of the first bi-annual “Ask a Biologist” podcast contest, and they were chosen based on their vocal skills, curiosity, and creativity by the panel of judges.

Questions are in fact the lifeblood of Kazilek. As director of technology integration and outreach in the ASU School of Life Sciences, he created “Ask-a-Biologist,” the innovative K-12 children’s science education Web site specifically to provide answers to the puzzled, perplexed and just plain curious. A portal for fun and facts, the site receives more than 200 questions a month and 500,000 unique visitors a year. As its host Dr. Biology, a Web persona created by Kazilek, has interpreted more than 20,000 queries in the last 10 years – and has only been stumped a dozen times.

“I like to say that Dr. Biology is the smartest person I know,” Kazilek quips.

Dr. Biology’s formidable intellect is backed by a pool of more than “100 mostly willing volunteers” from ASU’s School of Life Sciences in the College of Liberal Arts and Sciences. With more than 350 faculty and graduate students to call upon, there is no lack of experts to help K-12 students fathom the most ancient and most technologically sophisticated changes in the world.

The Web site took a technological and creative leap of its own in 2007, launching a podcast program, and creating a home base – Grass Roots Studio – where Kazilek and his colleagues record. Twice monthly, children, adults, home-schoolers and teachers can download the sounds of the Tibetan plateau or drop into a conversation with a Pulitzer Prize winning ant adventurer.

However, according to Kazilek, one voice was missing, “the children themselves.” Hence, the podcast contest and search for child co-hosts was born.

“This is such a wonderful opportunity and a day of learning and lessons for us all,” says Helen Rentz, a third-grade teacher at Paul Laurence Dunbar Elementary School. “The children have never had anything like this available to them before. They were very motivated to research, to interview, to podcast, and it’s the first trip for them and their families to ASU.”

“This has definitely made an impact,” adds Joan Howell, teacher with the Accelerated Learning Procedures (ALPS) program in Phoenix in which all three students participate.

To become a podcast co- host, each student did a podcast interview and submitted a CD, much like a podcast version of “American Idol,” with support from their teachers. As winners, and as Kazilek’s co-hosts, they recorded a professional quality podcast that is broadcasted internationally. In addition to meeting and interviewing scientists, the children (and their teachers) get a day off from school and the chance to pick up some hands-on science techniques. They also receive one of the tools of their trade – an Apple Ipod Shuffle.

Cheatham, Mendez, and Varela are the first three of 12 students who will be featured on Ask-a-Biologist each year. “When do we get to see the feathers?” Brian asks.

One of the scientist’s to be interviewed is Kevin McGraw, a researcher who studies bird feather coloration and behavior. He has feathers to hand out and questions of his own for the children: “What’s the world’s longest feather?” (Five feet, seven inches belonging to a crested Argus pheasant). “Who has the most feathers?”

Varela flips over a Golden pheasant skin and passes it to Taylor whose eyes open wide. McGraw knows what make children tick. He talks about genetically engineered, naked chickens used to simulate dinosaurs running for the movie Jurassic Park and reveals that swans have more then 25,000 feathers, while hummingbirds only about 940. Varela picks up the long plume of a macaw, blue on one side, yellow on another, a question forming on his lips, one of many that will frame his interview later with McGraw.

“Can I have a bird?” Cheatham asks her dad as the children leave the McGraw’s laboratory to prepare to do their interviews. “Yes,” he replies, watching her leave. “But I’d really like to have an ant farm.”

To hear Taylor’s interview, go to the Ask-a-Biologist Web site: http://askabiologist.asu.edu/podcasts/index.html#Gutierrez (volume 33).
Details and deadlines for future contests can be found at http://askabiologist.asu.edu/podcasts/contest.html.

Ask a Biologist is recognized by the Arizona Technology in Education Alliance and the Center for Digital Education. It was also the winner of the 2003 ASU President’s Award for Innovation.

Hike highlights nature of Papago Buttes

lccampb — Fri, 28 Mar 2008 17:06:26 -0600

From 9 a.m. until 1 p.m., April 5, the red rocks of Papago Buttes will witness a surge in maroon and gold as ASU School of Life Sciences’ faculty and students put aside their microscopes and lecture notes to lead guided hikes for the community in the park, starting from ramada No. 16.

SOLS Takes a Hike organizers James Elser, an ecosystems biologist, Pierre Devich, a birding expert, and Susanne Neuer, an oceanographer, will just be three of more than a dozen ecologists, geologists and field biologists who lead four short nature walks looping through the park.

Families will get a broad perspective about Papago Park, its wildlife, fauna, and underlying geology. Besides these guided tours, reptile experts Andy Holycross and Dale DeNardo will attend with rattlesnakes, to talk about snake safety, and share the beauty of Gila monsters.

Holycross is the co-author of “A Field Guide to Amphibians and Reptiles in Arizona,” with co-author Thomas Brennan. The guide was recently released by Arizona Game and Fish.

SOLS Takes a Hike was launched in 2006 as an annual community outreach event and is one of the many in the quiver of community events and programs in which students, staff and faculty are actively engaged. This event is free and open to the public.

For more information on the hike, call ASU’s School of Life Sciences in the College of Liberal Arts and Sciences at (480) 965-2705 or send an e-mail to Margaret Coulombe at margaret.coulombe@asu.edu.

Professor helps discover clue to delay of life on Earth

lccampb — Thu, 27 Mar 2008 14:20:41 -0600

Scientists from around the world have reconstructed changes in Earth’s ancient ocean chemistry during a broad sweep of geological time, from about 2.5 to 0.5 billion years ago. They have discovered that a deficiency of oxygen and the heavy metal molybdenum in the ancient deep ocean may have delayed the evolution of animal life on Earth for nearly 2 billion years.

The findings, which appear in the March 27 issue of Nature, come as no surprise to Ariel Anbar, one of the authors of the study and an associate professor at Arizona State University with joint appointments in the Department of Chemistry and Biochemistry and the School of Earth and Space Exploration in the College of Liberal Arts and Sciences. The study was led by Clint Scott, a graduate student at University of California Riverside. Scott works with Timothy Lyons, a professor of biogeochemistry at UCR who is a long-time collaborator of Anbar’s and also an author of the paper.

“Clint’s data are an important new piece in a puzzle we’ve been trying to solve for many years,” says Anbar. “Tim and I have suspected for a while that if the oceans at that time were oxygen deficient they should also have been deficient in molybdenum. We’ve found evidence of that deficiency before, at a couple of particular points in time. The new data are important because they confirm that those points were typical for their era.”

Molybdenum is of interest to Anbar and others because it is used by some bacteria to convert the element nitrogen from a gas in the atmosphere to a form useful for living things – a process known as “nitrogen fixation.” Bacteria cannot fix nitrogen efficiently when they are deprived of molybdenum. And if bacteria can’t fix nitrogen fast enough then eukaryotes – a kind of organism that includes plants, pachyderms and people – are in trouble because eukaryotes cannot fix nitrogen themselves at all.

“If molybdenum was scarce, bacteria would have had the upper hand,” continues Anbar. “Eukaryotes depend on bacteria having an easy enough time fixing nitrogen that there’s enough to go around. So if bacteria were struggling to get enough molybdenum, there probably wouldn’t have been enough fixed nitrogen for eukaryotes to flourish.”

“These molybdenum depletions may have retarded the development of complex life such as animals for almost two billion years of Earth history,” says Lyons. “The amount of molybdenum in the ocean probably played a major role in the development of early life.”

This research was motivated by a review article published in Science in 2002 by Anbar and Andy Knoll, a colleague at Harvard University. Knoll was perplexed by the fact that eukaryotes didn’t dominate the world until around 0.7 billion years ago, even though they seemed to have evolved before 2.7 billion years ago. Together, Anbar and Knoll postulated that molybdenum deficiency was the key, arguing that the metal should have been scarce in ancient oceans because there was so little oxygen in the atmosphere in those times.

In today’s high-oxygen world, molybdenum is the most abundant transition metal in the oceans. That is because the primary source of molybdenum to the ocean is the reaction of oxygen with molybdenum-bearing minerals in rocks. So the hypotheses rode on the idea that the amount of molybdenum in the oceans should track the amount of oxygen. To test that idea, Scott, Lyons and Anbar examined rock samples from ancient seafloors by dissolving them in a cocktail of acids and analyzing the rock for molybdenum content using a mass spectrometer. Many of these analyses were carried out using state-of-the art instrumentation in the W. M. Keck Foundation Laboratory for Environmental Biogeochemistry at Arizona State University. The scientists found significant evidence for a molybdenum-depleted ocean relative to the high levels measured in modern, oxygen-rich seawater.

By studying Earth’s ancient oceans, atmosphere and biology we can test how well we understand the modern environment, according to Anbar. “Our molybdenum hypothesis was inspired by the theory that biology in the oceans today is often starved for a different metal – iron – and that the lack of iron in parts of the oceans affects the transfer of the greenhouse gas carbon dioxide from the atmosphere to the ocean” he says. “The idea that metal deficiency in the oceans can affect the entire planet is very powerful. Here, we are exploring the limits of that idea by seeing if it can solve ancient puzzles. These new findings strengthen our confidence that it can.”

Anbar, Lyons and Scott were joined in the research by A. Bekker of the Carnegie Institution of Washington, D.C.; Y. Shen of the University du Quebec a Montreal; S.W. Poulton of Newcastle University, Newcastle upon Tyne, United Kingdom; and X. Chu of the Chinese Academy of Sciences, Beijing, China. The research was supported by grants from the U.S. National Science Foundation Division of Earth Sciences and the NASA Astrobiology Program.

This new publication in Nature follows on the heels of two related papers published in Science last September by Anbar, Lyons, Scott and other colleagues: http://clas.asu.edu/newsevents/newsreleases/2007/oxygenwhiff_09272007.htm.

ASU MEDIA CONTACTS:
Jenny Green, jenny.green@asu.edu
480-965-1430

Nikki Staab, nstaab@asu.edu
480-965-8122

ASU boosts middle school science instruction

mattcrum — Tue, 25 Mar 2008 13:33:00 -0600

Students in Arizona’s middle schools will benefit from improved science instruction through a Board of Regents grant awarded to Arizona State University’s College of Teacher Education and Leadership (CTEL). CTEL professors and staff are collaborating with ASU colleagues to develop online courses to broaden the knowledge base of middle school science teachers.

Three online courses are now being readied to be taught in a pilot program this fall. A small group of middle school teachers will take each of the pilot classes, focusing on life science, physical science, and earth/space science. The Glendale and Isaac Elementary School Districts are working with CTEL as partners in piloting the new classes.

“Many middle school science teachers have prepared themselves by focusing on one area, such as biology,” says Ray Buss, associate professor in CTEL. “Taking classes in the other content areas will expand their knowledge and confidence as they teach important science concepts in their classrooms.”

Once the pilot program is complete, teachers around Arizona will be able to start taking any or all of the three online classes in the Spring 2009 semester. Undergraduate students planning to pursue teaching careers are eligible to take the classes as well.

Buss and fellow CTEL faculty member Ron Zambo collaborated on the proposal that resulted in the $122,499 Improving Teacher Quality grant from the Arizona Board of Regents.

Other ASU faculty participants in the project include Steven Semken from the School of Earth and Space Exploration, Gina Hupton from the New College of Interdisciplinary Arts and Sciences, and Robert J. Culbertson from the Department of Physics. All three have experience in curriculum design and delivery of instruction to K-12 teachers. Faculty and staff who possess expertise in design and delivery of online courses also are involved.

“This is exactly the type of collaborative effort Arizonans should expect from their public universities,” says Mari Koerner, dean of CTEL. “For the state to be competitive in the global marketplace, it’s critically important that our children graduate from high school with a solid understanding of how to use scientific knowledge to make good decisions not only in their everyday lives but to prepare for careers for which they need these skills. We are bringing together faculty experts in several fields to make a positive impact on learning in Arizona’s K-12 classrooms.”

Under federal guidelines and new Arizona teacher certification requirements, teachers wishing to become highly qualified to teach science in middle school grades must pass the Middle Grades General Science exam as part of the Arizona Educator Proficiency Assessments (AEPA).

The middle school science test includes questions focusing on life science, physical science, earth and space science, and the nature of science.

“We have had conversations with several school districts in the Valley about teachers who need assistance in preparing to pass the AEPA middle school science test,” Buss says. “While the numbers aren’t large in any one district, overall there is a real but widely dispersed need for instruction in science content.

“Making these courses available online will benefit teachers not only in the Phoenix area but across Arizona, including rural areas where teachers might otherwise not have access to this curriculum.”

Working teachers will have the option of using one or more of the online science courses as part of a Master of Education degree program in Elementary Education or Secondary Education offered through CTEL. The classes also will be available to undergraduate Elementary Education majors who are interested in becoming middle school science teachers.

For more information, contact Ray Buss at (602) 543-6343 or ray.buss@asu.edu.

Located on ASU’s West campus, the College of Teacher Education and Leadership collaborates with educational and civic communities to prepare and inspire innovative educators to be leaders who apply evidence-based knowledge that positively influences students, families, and the community. More information is available at http://ctel.asu.edu.

Science-engineering fair seeks additional volunteer help

lccampb — Thu, 06 Mar 2008 15:00:20 -0700

ASU’s American Indian Programs Office is gearing up for one of its biggest youth science events in Arizona – the Arizona Science and Engineering Fair March 18-21 at the Phoenix Convention Center.

The development of students in the science, technology, engineering and math (STEM) areas is a priority for the region – so much so that Gov. Janet Napolitano has proclaimed March as “Youth Science and Engineering Awareness Month.”

The science fair, a compilation of the Northern Arizona Regional Science and Engineering Fair, Central Arizona Regional Science and Engineering Fair and the Arizona American Indian Science and Engineering Fair, encourages students about the STEM subjects. Several Arizona students who have participated in past science fairs have been nationally recognized.

This year, more than 800 fifth- through twelfth-grade students from nine of the 14 Arizona counties will compete against their peers with science projects centered on categories such as engineering, mathematics, medicine and health, plant sciences, and behavioral and social sciences.

“Many of the projects at the science fair were the top winners at a school or district science fair,” says Phillip Huebner, director of the American Indian Programs and lead organizer.

Students are eligible to win more than 300 awards, according to Huebner, and teachers are eligible for special awards, as well as “Teacher of the Year.”

“We may be holding the largest science fair in the state, but we could not have done it without the cooperation of schools and teachers, as well as a number of other people up to this point,” Huebner says. “Of course, we have a lot of people helping at the event, too.”

But more are still needed, according to Lois Hedlund, event coordinator.

“We need about 100 more volunteers to help with the event over the three days,” she says.

More than 400 volunteers are needed. So far, more than 265 people from industry, academia, K-12 education and even retirees have been recruited to be judges and help direct students to their location, assist with set up and registration, assist in workshops, help with the awards ceremony March 21, and other activities.

Those who are interested in volunteering can contact Huebner at (480) 727-1036, Hedlund at (480) 727-1148 or visit the Web site http://azsef.asu.edu/home.html to register as a volunteer.

Dawkins to deliver 'BEYOND' lecture

chughes3 — Tue, 04 Mar 2008 18:04:39 -0700

Richard Dawkins, a renowned evolutionary biologist and popular science writer, will deliver this year’s BEYOND lecture, based on his controversial book “The God Delusion,” at 7:30 p.m. March 6 in Gammage Auditorium on ASU’s Tempe campus.

“Richard Dawkins is one of the world’s finest expositors; he lectures with passion and commitment on provocative themes,” says Paul Davies, an ASU professor, internationally acclaimed theoretical physicist, cosmologist and founding director of the BEYOND Center for Fundamental Concepts in Science.

The BEYOND Center is a “cosmic think tank” established at ASU in 2006.

“The Beyond annual lecture challenges one of the world’s leading intellectuals to think beyond the confines of their specialism, and to offer new insights into science, philosophy or futurology,” Davies says.

Dawkins is “not one to shy away from controversy,” says Davies. Discover magazine labeled him “Darwin’s Rottweiler” for his fierce defense of evolution, while Britain’s Prospect magazine voted him among the top three public intellectuals in the world.

Professor Dawkins is the first holder of the endowed Charles Simonyi Chair in the Public Understanding of Science at the University of Oxford. A graduate of Oxford, Dawkins did his doctorate under the Nobel Prize-winning ethologist Niko Tinbergen. In 1967, Dawkins was appointed assistant professor of zoology at the University of California at Berkeley, returning to Oxford in 1969. He has been a Fellow of New College since 1970.

“The God Delusion” was published in 2006. Other books include “The Selfish Gene” and “The Extended Phenotype.” “The Blind Watchmaker” won the Royal Society of Literature Award and the Los Angeles Times Prize, both in 1987. His other best-sellers include “River Out of Eden,” “Climbing Mount Improbable,” “Unweaving the Rainbow,” “A Devil’s Chaplain” and “The Ancestor’s Tale.”

In 1997, Dawkins won the International Cosmos Prize. Other awards have included the Silver Medal of the Zoological Society of London (1989), the Royal Society’s Michael Faraday Award (1990), the Nakayama Prize for Achievement in Human Science (1990) and the Kistler Prize (2001). He also won the Shakespeare Prize for Contribution to British Culture (2005). More recently, he received the Lewis Thomas Prize (2007) and the Karlheinz Deschner Award (2007).

The British ethologist has honorary doctorates in both literature and science and is a Fellow of the Royal Society of Literature as well as a Fellow of the Royal Society.

Tickets are required for the lecture, which is free and open to the public. While there are no longer tickets available, unclaimed seats will be given away beginning at 7:15 p.m. People who do not have tickets are advised to form a line at 6:45 p.m. Additional information at beyond.asu.edu.

The BEYOND Center for Fundamental Concepts in Science, is a pioneering international research center at Arizona State University in the College of Liberal Arts and Sciences. The center is specifically dedicated to confronting the big questions raised by advances in fundamental science, and facilitating new research initiatives that transcend traditional subject categories.

Carol Hughes, carol.hughes@asu.edu
480-965-6375
College of Liberal Arts and Sciences

Professor makes movie debut in science film

jkullman — Fri, 22 Feb 2008 13:26:14 -0700

Rustum Roy, a research professor in ASU’s School of Materials, is featured in a new documentary film that explores claims of revolutionary advances in the scientific understanding of the most essential material for life – water.

The School of Materials is jointly administered by the Ira A. Fulton School of Engineering and the College of Liberal Arts and Sciences.

The film is set for its United States debut on Feb. 22 at the Harkins Valley Art movie theater in Tempe.

Titled simply Water, the documentary examines new discoveries by researchers around the world on the physical and metaphysical aspects of water. Experts in diverse fields explain not only the biological, environmental, climatological and agricultural importance of water, but its connection to social behavior, politics, religion and medicine.

The documentary by Russian filmmaker Saida Medvedeva is being distributed by Intention Media, a company led by filmmaker Betsy Chasse, a co-creator of What the Bleep Do We Know?! – one of the most popular feature-film documentaries of recent years.
Water has already debuted in Europe, where it has won various awards for best documentary, best popular science film, producing and cinematography.

Roy, a materials scientist, talks about his research in the documentary, discussing his many years of work to characterize the “structure” of water and the ability to change its structure for use in various ways, such as adapting it for development of medicines.

Roy is the founding director of Penn State University’s Materials Research Laboratory. In addition to his post at Penn State, he has held joint appointments at ASU and the University of Arizona for the past several years.

He is a member of national science and engineering academies in the United States, Japan, Russia, Sweden and India.

Fighting hospital 'superbugs' with math modeling

chughes3 — Tue, 19 Feb 2008 18:18:42 -0700

A mathematical model that looks at different strategies for curbing hospital-acquired infections suggests that antimicrobial cycling and patient isolation may be effective approaches when patients are harboring dual-resistant bacteria.

In an era of “superbugs,” such as methicillin-resistant Staphylococcus aureas (MRSA), and an increasing public awareness and concern over bacterial infections, this type of modeling, if used to develop policies and treatment protocols, may reduce dual drug-resistant infections in hospitals.

The model’s results were presented by Carlos Castillo-Chavez, an Arizona State University Regents’ Professor on Feb. 17 at the American Association for the Advancement of Science annual meeting. Castillo-Chavez was honored at the meeting with the 2007 AAAS Mentor Award for his efforts to help underrepresented students earn doctoral degrees in the sciences.

In discussing the mathematical models, he notes that the research is an outgrowth of an undergraduate honors thesis by Karen C. Chow, now a graduate student at ASU, in collaboration with his postdoctoral research associate Xiaohong Wang.

“We deal primarily with the issue of finding ways of slowing down the growing levels of dual resistance to antimicrobials that are the result of their intense use in the treatment of nosocomial (hospital-acquired) infections,” says Castillo-Chavez, a mathematical epidemiologist in ASU’s College of Liberal Arts and Sciences.

“Model simulations were used to compare the effects of antimicrobial cycling, in which antibiotic classes are alternated over time, with mixing programs (random allocation of treatment drugs) in a setting where the goal is that of reducing the prevalence of dual resistance,” Castillo-Chavez says.

“Resistance to multiple drugs cannot be ignored and cycling programs appear more useful in reducing dual resistance than the random mixing regime,” he says. “The early diagnosis and isolation of colonized patients with dual-resistant bacteria turns out to be quite effective at maintaining lower levels of dual resistance in hospitals.”

He notes: “This seems to be the first time that models are used to deal with the evaluation of two distinct methods of reducing the impact of dual resistance in hospitals. Models that focus on reducing the prevalence of pathogens resistant to two types of drugs, excluding the possibility of dual resistance, have been studied in the past. Models were used to show that random allocation treatment regimes might be better than cycling.

“Here, we show that cycling may be useful when dealing with dual resistance – the most worrisome hospital situation,” he says.

“Our theoretical work shows that cycling is better if the goal is to reduce dual antimicrobial resistance. We explore the impact of isolating individuals who have developed dual resistance and found out that isolation, in fact, dramatically reduces the persistence of dual resistance. However, we never win the battle against antimicrobial resistance through the exclusive use of integrated microbial management approaches that focus entirely on the prescription of antibiotics,” he says.

“Focusing on reducing dual resistance results in increases in the levels of individuals experiencing single resistance. In other words, at the end of the day, drugs provide no silver bullet and only policies that reward their judicious use have a shot at slowing down what appears to be a loosing battle,” he says.

“If we insist in the exclusive use of antimicrobials to fight nosocomial infections, then it is only a matter of time before we begin to run out of effective antibiotics.”

The next step, according to Castillo-Chavez, is to connect these models more explicitly to specific studies, and to collaborate with others who are treating patients in hospitals.