thursday, september 27, 2012
The california Aggie
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Putting the bite back in the bark UC Davis researchers advance bone biomedicine in dogs By OYANG TENG Aggie Science Writer
In medicine, the road from laboratory research to clinical application is often a long and complicated route. But sometimes, it's no farther than a five-minute walk. Such is the unique advantage enjoyed by doctors at UC Davis Veterinary Teaching Hospital, nestled among a complex of biomedical research facilities on the southwestern edge of campus that includes the Musculoskeletal Bioengineering lab of Kyriacos Athanasiou. The partnership between the lab and the hospital has produced a successful new treatment for regenerating bones that have been fractured or surgically removed in the jaws of dogs, a technique that may eventually be applied to human patients. “This kind of work exemplifies the collaboration that happens at UC Davis,” said Boaz Arzi, a veterinary surgeon who is also a member of the Athanasiou lab. “Basically, magic can be done.” The new surgical technique was put to its most challenging test in the case of Whiskey, a 10-year-old Munsterlander dog who needed almost half his lower right jawbone removed because of a type of cancer called squamous cell carcinoma, the most common type of oral cancer in humans. After surgically removing the infected portion of Whiskey's jaw, Arzi, along with a team that included the hospital’s Dentistry and Oral Surgery Service Head Frank Verstraete and Athanasiou lab tissue engineer Dan Huey, attached a titanium rod shaped to match the jaw line to the remaining bone, bridging the 6-centimeter gap. “Formerly, when we had to remove a portion of the bone we were forced to leave the defect in the jaw because there was no better alternative,” Verstraete said. A specially constructed sponge-like scaffold composed of collagen and the mineral hydroxyapatite, both constituents of normal bone tissue, and infused with a precise dose of a growth-promoting protein, was then inserted into the gap and attached to the tita-
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nium rod. Bone morphogenetic protein – first purified for clinical use in the 1980s by UC Davis orthopedic surgeon A. Hari Redi – is responsible for helping to recruit stem cells in the surrounding bone and tissue to differentiate into new bone cells. “It's not very difficult to regenerate bone,” Arzi said. “It's difficult to regenerate bone over a large, critical-sized defect. And it's more difficult to try to get it right without side effects.” After three months, the scaffolding in Whiskey’s jaw had been almost entirely replaced by new bone growth, marking a triumph of the delicate refinements needed to
coordinate scaffolding and protein for the specific requirements of a dog’s jawbone. “The thing with bone morphogenetic protein is that it’s dose dependent, scaffold dependent and species dependent,” said Arzi. “So, for example, the same doses we use for dogs is different from the dose we would use for humans. So it really needs to be tailored per animal, per procedure, per bone event. It's finding the right recipe which makes this [procedure] unique.” With eight out of eight successful surgeries, the team is now publishing its results. Arzi sees great promise in similar collaboration for future projects, including ongo-
ing work on disorders of the temporomandibular joint connecting the jaw to the skull, which are common in both dogs and humans. “Taking people like those at the Athanasiou lab, with their knowledge base and understanding of the material, and combining it with our surgical expertise makes it really fertile ground,” Arzi said. “It's exciting; it's definitely changed the way we think. I think that the team approach, with easy access to each other's expertise, is what makes it successful.” OYANG TENG can be reached at science@theaggie.org.
New breakthroughs in College of Agricultural and Environmental quantum computing Sciences deans resign
Physicists move forward in computer processor design
Neal Van Alfen and James D. MacDonald spurred by chancellor’s decision
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By BRIAN RILEY Aggie Science Writer
Researchers at UC Santa Barbara are breaking new ground in demonstrating the effectiveness of using the quantum properties of matter to build new “quantum processors” for the next generation of computers. Quantum computers use atoms to represent arithmetical bits that are called “qubits,” but in order to show that quantum processors can be built, the qubits must be able to be embedded into a computing system. An article appearing in Nature Physics, written by UCSB researchers in the Department of Physics, explains the new results. Erik Lucero, the main author of the paper, is now a research scientist at the IBM T.J. Watson Research Center in Yorktown Heights, N.Y. Lucero explains that quantum computers will be able to handle very complex calculations in the field of biology and medicine that cannot be handled with current technology. “We can envision being able to solve really complex problems that before all we could do was give a best guess at on a classical computer,” Lucero said. “This is a very simple demonstration and we are still years away from a quantum computer.” Lucero explains that the upcoming era of quantum computing will bring with it new levels of secure communication, due to the unique properties of matter at the quantum level. “With the quantum computer there’s actually a higher level of encryption called ‘quantum encryption,’” Lucero said. “What’s great about it is we will know if someone has been eavesdropping on our communication because the system will have changed.” Data encoded at the quantum level will be changed in some way, depending on whether the data has been observed by a third party. The power of quantum processors will be exponentially greater than current
computers because certain advanced forms of arithmetical computation can be mirrored by quantum operations. The researchers demonstrated the possibility of four qubits interacting in a special process called “multipartite entanglement.” “A single qubit is not enough to build the basic logic gates for a quantum computer,” said Matteo Mariantoni, who is a postdoctoral researcher in the UCSB physics department. “You also need connectivity on your quantum machine. This connectivity is given by ‘entanglement,’ where two qubits are talking to each other. Once you are able to control one and two qubits with very high accuracy, you then make the quantum machine bigger and bigger.” The interactions of the qubits in a quantum processor function similar to the way electrons flow through transistors in a conventional computer. However, instead of using silicon-based transistors, the new networks of logic gates at the quantum level exhibit a simultaneity of function that cannot be achieved at the macro level. Current computers, or “classical computers,” are reaching the physical limits of how small they can be constructed. “We’re getting to the limit where we can’t make [classical processors] any smaller,” said Daniel Sank, a graduate student in physics at UCSB. “The size of the wires [in current computers] is 45 nanometers. We’re running up against all these limits and at some point people realized that if we used a different kind of physical interaction, namely [the type in] quantum mechanics, you can do computations in a different way, and in some cases this winds up being enormously fast.” Lucero predicts that quantum computers will be able to be used for research in ways that classical computers fall short, such as in computations dealing with protein foldings and the efficient simulation of biological systems needed to design new drugs. BRIAN RILEY can be reached at science@theaggie.org.
Mary Delany, Associate Dean of CAES
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By GHEED SAEED Aggie News Writer
Neal Van Alfen and James D. MacDonald, the Dean of the College of Agricultural and Environmental Sciences (CAES) and Executive Associate Dean of the College of Agricultural and Environmental Sciences respectively, have resigned from their positions at UC Davis. The resignations are a direct response to Chancellor Linda Katehi’s decision to begin the search for a replacement Dean of the College two years prior to the end of Van Alfen’s term, rather than waiting the conventional final year to begin the search for a replacement. “Because I cannot support this decision by the campus leadership, I believe that the proper course of action for me is to step down from my administrative post,” states MacDonald’s e-mail to colleagues. MacDonald originally planned to retire in July 2012, but he was convinced by Van Alfen to maintain his position until July 2013 to help advance the College and several initiatives. In light of Katehi’s decision, MacDonald said that Van Alfen’s departure renders his agreement to prolong his departure “moot.” Interim Executive Director of Strategic Communications Barry Shiller explained that Van Alfen’s contributions will not go unacknowledged. “Dean Van Alfen was a terrific leader for UC Davis for almost 14 years; under his
leadership, the College of Agricultural and Environmental Sciences has made great progress. His and Professor MacDonald’s contributions to the University are greatly valued,” he said. In Provost Ralph Hexter’s letter to the campus community, Hexter credited Van Alfen for the advancements achieved under his leadership, such as establishing UC Davis as a global leader in sustainability and related disciplines. Hexter also announced that Dean Michael Lairmore of the School of Veterinary Medicine will chair the Recruitment Advisory Committee to identify a permanent dean for the College of Agricultural and Environmental Sciences. “Neal leaves CAES well poised for further excellence. The college, our oldest, is critical to our core mission and identity as a leading public research university making singular contributions to our state, our nation and the world,” said Hexter in the letter. In an e-mail to colleagues, Van Alfen cited Katehi’s decision to search for a replacement prematurely as his reason for resigning from his position. “The chancellor requested that I serve until a replacement is found, but given her decision to replace me before the end of my term, I feel I must resign,” he stated in his e-mail. “Our college is a collective responsibility, now as in the past, and I hope it remains in good leadership hands. It has been an honor to be dean of this great college and to serve with a remarkable group of associate deans, department chairs, faculty, institute and center directors, staff, and students of our college,” the e-mail stated. Associate Dean of the College of Agriculture and Environmental Sciences, Mary Delany, will serve as interim Dean of the College. Delaney, a distinguished avian geneticist, has served as associate dean since the year 2009. Delaney first joined the UC Davis faculty in 1995 in the departments of Avian Sciences and Animal Science. “Dean Van Alfen was a terrific leader for UC Davis for almost 14 years; under his leadership, the College of Agricultural and Environmental Sciences has made great progress. His and Professor MacDonald’s contributions to the University are greatly valued. Professor Delany, a well-regarded avian scientist, has stepped in on an interim basis,” Shiller said. GHEED SAEED can be reached at campus@theaggie.org.
Van Alfen and MacDonald in review on Page 9.