The University of Arizona (UA) College of Agriculture and Life Sciences (CALS) has hired four new associate deans. The leaders began their new positions Feb. 20.

"Every one of these new associate deans is committed to serving the faculty and students of the college," said CALS Dean Shane Burgess. "I am also specially tasking them not only to manage in each of their areas, but also to lead us all in defining how we will live within our budget and, at the same time, serve the people of Arizona by delivering on our mission to develop our state's people and our economy."

UA professor Jeff Silvertooth is the new associate dean for economic development and director of Arizona Cooperative Extension. His background includes direct and extensive experience in Cooperative Extension, research, instruction, administration, and service.

Silvertooth arrived at the UA in 1987 with a doctorate in soil science/soil fertility from Oklahoma State University. He worked as an extension agronomist in cotton for 14 years and eventually became a professor in the department of plant sciences and the department of soil, water, and environmental science (SWE).

Since 2000, Silvertooth has been head of the SWE department where he has continued to teach and conduct research in crop production systems and management strategies. His frequent work with international programs, particularly in Mexico, has had a direct connection to his applied research and extension education program.

Silvertooth believes that in the future the demand will increase for strong research, Extension, and outreach programs that work with the public and business sectors in an effective partnership. He will oversee an extensive team that has a presence in every county in the state.

Silvertooth replaces Jim Christenson, CALS cooperative extension director for 22 years, and interim director Kirk Astroth.

The new associate dean for research and director of the Arizona Agricultural Experiment Station is professor Ron Allen, a veteran animal scientist who has taught and conducted research at Iowa State University, Michigan State University, and since 1980, the UA.

Allen currently is the department head, the Roy and Phyllis Hislop Chair, and professor in the animal sciences department.

The focus of his research for nearly 30 years has been the growth and repair of skeletal muscle in domestic animals and humans. Not only has Allen contributed to Arizona's largest agricultural sector, his research also has been important for human health in the field of muscular dystrophy and in stem cell biology. His work in animal growth is helping the cattle industry develop new methods to increase food production at lower costs while enhancing animal health.

Allen will promote research areas consistent with primary needs of the state, including fundamental basic research and translational and applied research. He notes that value comes in the form of quality education and workforce development; research that facilitates economic development; and an independent, objective source of science-based information.

Allen replaces Colin Kaltenbach, who served as the CALS associate dean and director of the Arizona Experiment Station for 22 years before retiring in 2011.

Professor Joy Winzerling is the new Bart Cardon associate dean for academic programs and career development. Currently professor and head of the department of nutritional sciences, Winzerling also is a registered dietitian.

She graduated with a degree in biological science and a doctorate in nutritional sciences from the UA and completed postdoctoral training in the department of biochemistry and molecular biophysics and the Arizona Research Laboratories. Her cross-disciplinary research spans the fields of entomology and human nutrition.

Professor Soyeon Shim is the new associate dean for strategic initiatives, a newly created position she will hold while continuing as director of the Norton School of Family and Consumer Sciences and professor of retailing and consumer sciences.

This new position was created to take advantage of Shim's strategic leadership and management abilities as well as her business skills, at a time when the college is facing significant budgetary constraints requiring some elements of restructuring and innovative directions.