Five prominent researchers represented USC this month at the 181st annual meeting of the American Association for the Advancement of Science, the largest general science meeting in the world.
Laurie Eisenberg and Robert Shannon of the Keck School of Medicine of USC participated in a press briefing on Feb. 13 to unveil preliminary findings into research on the use of auditory brainstem implants (ABI) to help deaf children to hear — which they also presented to the scientific community the next day.
Eisenberg and Shannon are part of a multi-institutional team conducting a five-year clinical trial backed by the National Institutes of Health to test ABI on a limited number of children who were born with missing or badly damaged cochlear (hearing) nerves — who are, as such, unable to be helped by cochlear implants. Instead, ABI stimulates neurons on the brainstem directly.
“There’s a very long learning curve … but children are more plastic and flexible, which is why they may be able to benefit from this technology,” Eisenberg said.
So far, the team has successfully implanted ABI devices in four children who were born deaf. Eisenberg showed video footage of one of the children — a 3-year-old girl who had received the implants three months prior — learning to hear and speak.
“That shows us the incredible propensity of the brain to use reliable but scrambled information to reconstruct sensory information,” said Shannon, who also has joint appointments with the USC Viterbi School of Engineering and the USC Dornsife College of Letters, Arts and Sciences.
The Associated Press covered the team’s progress in a story that was picked up by the Los Angeles Times and USA Today.
That same day, Alan Willner, professor with USC Viterbi, spoke about the progress and impact of optical communications — celebrating 2015 as the “International Year of Light,” as declared by UNESCO.
Willner explores new ways to speed up data transmission through fiber optic cables — the backbone for much of the Internet.
Whereas radio transmissions use radio waves to transmit data, optics uses light waves. The principles remain roughly the same, but with some important twists. Normally, the bigger the power of your signal, the more data you can send. The problem is, optical fiber limits that power and degrades the signal after a certain point due to “non-linear” properties of the glass fiber. So scientists are continually trying to find ways to push the boundaries of how much data they can jam through fiber optic cables — with significant success.
So far, transmission capacity has increased by about two orders of magnitude every decade, Willner said.
“We are better than Moore’s Law,” he said, a reference to a 1965 observation on transistors made by Gordon Moore, co-founder of Intel.
“Back in the day, you’d send someone an email and call every few hours to ask, ‘Did you get it? Did you get it?’ Now you have real-time video chat.”
Scientists have achieved these gains by finding creative ways to cram more data into the light. This is due in part through multiplexing — that is, combining multiple independent data signals by staggering them to keep them distinct based on time, wavelength (or frequency) and polarization.
“It’s just a wave,” Willner said. “If something worked in RF [radio frequency] transmission, you might as well try it in optical communications too.”
Now he hopes the research and development community finds ways to build cost-effective photonic integrated circuits — chips that transmit data using light instead of electrical signals. Just as electronic integrated circuits made for reliable, high-performance and low-cost deployment of electronics wherever it could be used, photonic integrated circuits could potentially do the same for the ubiquitous future deployment of photonics.
“The world runs on communications. The world runs on fiber optics,” Willner said, later adding, “We’re too important to fail. We underlie too many crucial technologies.”
Stones and bones
Later that afternoon, Frank Corsetti of USC Dornsife turned the focus from Willner’s ultra high-tech world to the stones-and-bones world of geology — discussing how understanding the mechanisms behind one of the greatest extinctions the Earth has ever seen can help predict the future impact of climate change.
These layers of rocks, they carry a story. It’s like a time machine.
“These layers of rocks, they carry a story. It’s like a time machine,” he said.
Corsetti’s research focuses on the Triassic-Jurassic extinction event, when the tectonic forces that ripped Pangea apart caused a massive lava flow known as the Central Atlantic magmatic province, or CAMP.
Though the exact causes of the extinction event remains a subject of debate, CAMP lava spewed an enormous amount of carbon dioxide into the air, warming global temperatures and driving a spike in ocean acidification. About 76 to 84 percent of species disappeared, by some estimates. Coral reefs and animals that use calcium carbonate to create their shells were particularly hard hit as rising ocean acidity dissolved those shells.
Corsetti joked that his presentation could be called “Sponges Clean Up in the Early Jurassic” — an apt title, given that he showed evidence that silica-shelled sponges flourished during this time, as carbon dioxide enhanced silicate weathering of the crust, dumping additional silica into the environment for their use.
“If you’re a sponge, you look back at the T-J boundary and say that was the best time in Earth’s history,” Corsetti said.
Gradually, the amount of carbon dioxide in the environment decreased, possibly consumed by the silicate weathering process.
So in an era of rising carbon dioxide levels and increasing ocean acidification, are we poised for another sponge takeover? Corsetti doesn’t think so, pointing to the proliferation in the world today of diatoms — algae that use silica to build their shells.
“Perhaps diatoms are the next ‘winner’ in this situation,” he said.
STEM education tactics
Early on the morning of Feb. 15, Adrianna Kezar of the USC Rossier School of Education provided insight on research-based tactics for implementing change in higher education to a symposium addressing the need to smooth students’ pathway through the notoriously “weed-out” culture of science, technology, engineering and math (STEM) education.
Currently, only about 40 percent of STEM undergraduate-degree aspirants graduate with that degree. Kezar, who is co-directing a three-year National Science Foundation-funded project aimed at reforming STEM education, said that too often schools simply try to throw money at the problem or try out some flashy new pedagogy. Instead, research can inform reform efforts to keep students from falling through the cracks.
“If we look at data, we can start to understand these holes, and we can start to fill them,” Kezar said.
Instead, Kezar suggested that colleges and universities can turn to proven frameworks for executing reform — name-checking the PKAL/Keck Guide to Systemic Institutional Change, among others. PKAL/Keck — an initiative of the American Association of American Colleges & Universities — is based on 20 years of research and experience on reforming STEM education and takes a holistic approach.
Successful reform efforts need to tackle assumptions that teachers have about students, assumptions that students have about the world of STEM and assess what the overall goal of a science education really is. Overcoming inertia in the educational world remains a key challenge, she said.
“We excuse a lot of underlying issues — that’s what’s hard about this,” Kezar said. “We just assume that everything has to be how it is, even if it doesn’t support student success.”
AAAS is the world’s largest general scientific society and the publisher of the journal Science.