Tucson tech: Desert shrub guayule may be new major source of natural rubber

University of Arizona professor Dennis Ray shows guayule bushes at the UA agriculture center. The UA was awarded a $3 million, five-year grant by Phoenix-based Yulex Corp. focused on developing guayule for production.

Tucson tech: Desert shrub guayule may be new major source of natural rubber

The latex produced in scruffy-looking guayule's bark doesn't contain the proteins that makes people allergic to common natural latex.

Tucson tech: Desert shrub guayule may be new major source of natural rubber

Twenty years ago, scientists at the University of Arizona began studying guayule, a small desert shrub farmed as a source of natural rubber.

2013 University of Arizona Graduation-Light Show at End

Video of the light show finale of the 2013 University of Arizona graduation ceremony.

Class of '13 send-off feels 'like a concert'

Creative-writing major Jacqueline Vito, 21, captures the moment on video with her iPhone as she enters the stadium before the 2013 University of Arizona spring commencement for undergraduate and master's students at Arizona Stadium.

Class of '13 send-off feels 'like a concert'

Claudia Diaz Combs photographs mortarboards of fellow students before they become graduates. More than 6,000 degrees were awarded Friday.

Class of '13 send-off feels 'like a concert'

Long lines form to enter Arizona Stadium before the 2013 commencement, which was last held on the football field in 1972, in an era when much of the technology used Friday was unheard of.

Class of '13 send-off feels 'like a concert'

Graduates Eddie Khav, bottom left, and Aishan Shi, bottom right, form the letter "A" with the help of Jonathan Wan while Eric Cascketta, standing, enjoys their high jinks.

Class of '13 send-off feels 'like a concert'

Family members and friends in the stands found ways to show graduates on the football field their support. Several signs here are meant to get the message to a graduate named Anthony .

Class of '13 send-off feels 'like a concert'

Every new University of Arizona graduate had a chance to see his or her smiling face on the Jumbotron on Friday night as commencement returned to Arizona Stadium.

6,600 University of Arizona students graduate tonight

University of Arizona seniors in front of Old Main on the UA campus. Old Main has been closed to students this semester because of construction, but the east side is open for graduation photos.

6,600 University of Arizona students graduate tonight

UA seniors Scott Eastman, Lexi Shinn and Isaac Gealer pose behind the Forbes Building, a popular photo backdrop.

6,600 University of Arizona students graduate tonight

UA seniors Isaac Gealer, Chelsea McLean, Garrett Voge and Andrea Beebe sit by the Joseph Wood Krutch Cactus Garden, providing a Western feel to the photograph.

6,600 University of Arizona students graduate tonight

UA seniors Cylan Shaffer and Fiona Foster pose at another popular photo spot, the Arizona State Museum near the Main Gate.

6,600 University of Arizona students graduate tonight

UA mascots Wilbur and Wilma pose by the Wildcat Family statue.

6,600 University of Arizona students graduate tonight

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6,600 University of Arizona students graduate tonight

Natalie Becker

6,600 University of Arizona students graduate tonight

After four years at the University of Arizona, Natalie Becker is going to work in a largely thankless job with a high burn-out rate - and she couldn't be happier.

Report: Warming threatens SW grid

TEP says it's already dealing with some impacts of extreme weather and trying to anticipate others. Above, apprentice lineman Florencio Ortega, left, worked with linemen John Hartnett, middle, and Danny Tellez as they moved a live wire to make way for a higher capacity line along Congress St…

Report: Warming threatens Southwest's power grid

The Southwest's power grid could become more vulnerable to climate change over the coming decades, says a new report led by University of Arizona researchers.