News & Events


Erik Winfree Controls Complex Nucleation Processes using DNA Origami Seeds


"Flowers, dogs, and just about all biological objects are created from the bottom up," says Erik Winfree, associate professor of computer science, computation and neural systems, and bioengineering at Caltech. Along with his coworkers, Winfree is seeking to integrate bottom-up construction approaches with molecular fabrication processes to construct objects from parts that are just a few billionths of a meter in size that essentially assemble themselves. In a recent paper in the Proceedings of the National Academy of Sciences (PNAS), Winfree and his colleagues describe the development of an information-containing DNA "seed" that can direct the self-assembled bottom-up growth of tiles of DNA in a precisely controlled fashion. In some ways, the process is similar to how the fertilized seeds of plants or animals contain information that directs the growth and development of those organisms. [Caltech Press Release]

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Morteza Gharib and Abbas Nasiraei Moghaddam Show Function of Helical Band in Heart


Using an MRI technique, Morteza Gharib, Hans W. Liepmann Professor of Aeronautics and Professor of Bioengineering, and his colleague Abbas Nasiraei Moghaddam, a Caltech graduate and visitor in Bioengineering, were able to create some of the first dynamic images of normal heart muscle in action at the tissue level. They showed that a muscular band--which wraps around the inner chambers of the heart in a helix--is actually a sort of twisting highway along which each contraction of the heart travels. "We tagged and traced small tissue elements in the heart, and looked at them in space, so we could see how they moved when the heart contracts," Gharib explains. "In this way, we were able to see where the maximum physical contraction occurs in the heart and when--and to show that it follows this intriguing helical loop." [Caltech Press Release]

Tags: research highlights GALCIT MedE health Morteza Gharib

Popular Mechanics Honors Caltech Alumni at Award Ceremony


Popular Mechanics honored a group of Caltech alumni at its annual Breakthrough Awards ceremony on October 15. Rudy Roy ('07), Ben Sexson ('07), and Daniel Oliver ('07), along with Art Center alum Charles Pyott, received the magazine's Next Generation Award for establishing the nonprofit organization Intelligent Mobility International (IMI). IMI's mission is to empower people with disabilities in developing countries by designing and producing safe, affordable wheelchairs made for the rugged terrain of rural communities. The project originated in 2006, in a Caltech class called Product Design for the Developing World, which is taught each fall by Visiting Professor of Mechanical Engineering Ken Pickar. [Read more on green design in Caltech News...]

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Michael Elowitz, Long Cai, and Chiraj Dalal Find Cells Coordinate Gene Activity with FM Bursts


How a cell achieves the coordinated control of a number of genes at the same time, a process that's necessary for it to regulate its own behavior and development, has long puzzled scientists. Michael Elowitz, assistant professor of biology and applied physics, along with postdoctoral research scholar Long Cai, and graduate student Chiraj Dalal, have discovered a surprising answer. Just as human engineers control devices ranging from dimmer switches to retrorockets using pulsed--or frequency modulated (FM)--signals, cells tune the expression of groups of genes using discrete bursts of activation. [Caltech Press Release]

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Peng Yin Creates DNA Tubes with Programmable Sizes for Nanoscale Manufacturing


Peng Yin, a senior postdoctoral scholar in bioengineering and computer science at IST Center for Biological Circuit Design, along with his colleagues, has designed a series of flexible, single-stranded DNA molecules for nanoscale manufacturing. The group has developed a simple process for mass producing these molecular tubes of identical, and precisely programmable, circumferences. [Caltech Press Release]

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Emmanuel Candes Receives Information Theory Society Paper Award


Emmanuel Candes, Ronald and Maxine Linde Professor of Applied and Computational Mathematics, has garnered the 2008 Information Theory Society Paper Award jointly with Terence Tao and David Donoho. Their ground-breaking papers were cited for independently introducing the new area of compressed sensing, which holds great promise for processing massive amounts of data, and has already had a broad impact on a diverse set of fields, including signal processing, information theory, function approximation, MRI, and radar design.

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Changhuei Yang Develops "Microscope on a Chip"


Changhuei Yang, Assistant Professor of Electrical Engineering and Bioengineering, and colleagues have turned science fiction into reality with their development of a super-compact high-resolution microscope, small enough to fit on a finger tip. This "microscopic microscope" operates without lenses but has the magnifyingpower of a top-quality optical microscope, can be used in the field to analyze blood samples for malaria or check water supplies for giardia and other pathogens, and can be mass-produced for around $10. [Caltech Press Release]

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Melissa Saenz and Christof Koch Show that Sight Recovery After Blindness Offers New Insights on Brain Reorganization


Studies of the brains of blind persons whose sight was partially restored later in life have produced a compelling example of the brain's ability to adapt to new circumstances and rewire and reconfigure itself. The research, conducted by postdoctoral researcher Melissa Saenz along with Christof Koch, the Lois and Victor Troendle Professor of Cognitive and Behavioral Biology and professor of computation and neural systems, and their colleagues, shows that the part of the brain that processes visual information in normal individuals can be co-opted to respond to both visual and auditory information. [Caltech Press Release]

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Chemistry of Airborne Particulate—Lung Interactions Revealed by Agustin Colussi and Colleagues


Agustin J. Colussi, senior research associate in environmental science and engineering, and colleagues have found that airborne particulates impair the lungs' naturaldefenses against ozone. Their research focused on what happens when air meets the thin layer of antioxidant-rich fluid that covers our lungs, protecting them from ozone, an air pollutant that pervades major cities. "We found new chemistry at the interfaces separating gases from liquids using a technique that continuously monitors the composition of these interfaces," Colussi says. Under normal physiological conditions, ascorbic acid instantly scavenges ozone, generating innocuous byproducts. However, the researchers discovered that when the fluid is acidic, a pathological condition found in asthmatics, ascorbic acid instead reacts with ozone to form potentially harmful compounds called ozonides.

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Michael Elowitz Named HHMI Investigator


Michael Elowitz, Assistant Professor of Biology and Applied Physics and a Bren Scholar, has been named a Howard Hughes Medical Institute (HHMI) investigator. Elowitz is fundamentally interested in how cells' own genetic circuits dictate what type of cells they become. In work that overturned the steadfastnotion that genes and networks of genes operate in a predictable and fixed fashion, he and his colleagues showed that key properties of the cell, like how actively it turns out different proteins, are intrinsically random. To show that randomness is used to more accurately control the shapes and patterns that make organisms work, Elowitz is turning to larger and more complex animal cells. "I'm grateful to HHMI for the amazing opportunity this appointment presents to focus as much as possible on research. The funds will enable us to explore new directions, especially allowing us to expand approaches we've previously developed primarily in bacteria to mammalian cells." [Caltech Press Release]

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