Thursday, September 25, 2014
Location to be announced

2014 Caltech Teaching Conference

Tuesday, May 13, 2014
Avery Library

Semana Latina Keynote Speaker – Dr. Rodolfo Mendoza-Denton

Friday, May 16, 2014
Center for Student Services 360 (Workshop Space)

The Role of Writing in Building a Research Career

Friday, May 30, 2014
Annenberg 105

Caltech Teaching Assistant Training for 2014-2015 Year

Research Update: An Autism Connection

Caltech neuroscientists find link between agenesis of the corpus callosum and autism

Building on their prior work (see "Bridging the Gap"), a team of neuroscientists at Caltech now report that rare patients who are missing connections between the left and right sides of their brain—a condition known as agenesis of the corpus callosum (AgCC)—show a strikingly high incidence of autism. The study is the first to show a link between the two disorders.

The findings are reported in a paper published April 22, 2014, in the journal Brain.

The corpus callosum is the largest connection in the human brain, connecting the left and right brain hemispheres via about 200 million fibers. In very rare cases it is surgically cut to treat epilepsy—causing the famous "split-brain" syndrome, for whose discovery the late Caltech professor Roger Sperry received the Nobel Prize. People with AgCC are like split-brain patients in that they are missing their corpus callosum—except they are born this way. In spite of this significant brain malformation, many of these individuals are relatively high-functioning individuals, with jobs and families, but they tend to have difficulty interacting with other people, among other symptoms such as memory deficits and developmental delays. These difficulties in social behavior bear a strong resemblance to those faced by high-functioning people with autism spectrum disorder.

"We and others had noted this resemblance between AgCC and autism before," explains Lynn Paul, lead author of the study and a lecturer in psychology at Caltech. But no one had directly compared the two groups of patients. This was a challenge that the Caltech team was uniquely positioned to do, she says, since it had studied patients from both groups over the years and had tested them on the same tasks.

"When we made detailed comparisons, we found that about a third of people with AgCC would meet diagnostic criteria for an autism spectrum disorder in terms of their current symptoms," says Paul, who was the founding president of the National Organization for Disorders of the Corpus Callosum.

The research was done in the laboratory of Ralph Adolphs, Bren Professor of Psychology and Neuroscience and professor of biology at Caltech and a coauthor of the study. The team looked at a range of different tasks performed by both sets of patients. Some of the exercises that involved certain social behaviors were videotaped and analyzed by the researchers to assess for autism. The team also gave the individuals questionnaires to fill out that measured factors like intelligence and social functioning.

"Comparing different clinical groups on exactly the same tasks within the same lab is very rare, and it took us about a decade to accrue all of the data," Adolphs notes.

One important difference between the two sets of patients did emerge in the comparison. People with autism spectrum disorder showed autism-like behaviors in infancy and early childhood, but the same type of behaviors did not seem to emerge in individuals with AgCC until later in childhood or the teen years.

"Around ages 9 through 12, a normally formed corpus callosum goes through a developmental 'growth spurt' which contributes to rapid advances in social skills and abstract thinking during those years," notes Paul. "Because they don't have a corpus callosum, teens with AgCC become more socially awkward at the age when social skills are most important."

According to Adolphs, it is important to note that AgCC can now be diagnosed before a baby is born, using high-resolution ultrasound imaging during pregnancy. This latest development also opens the door for some exciting future directions in research.

"If we can identify people with AgCC already before birth, we should be in a much better position to provide interventions like social skills training before problems arise," Paul points out. "And of course from a research perspective it would be tremendously valuable to begin studying such individuals early in life, since we still know so little both about autism and about AgCC."

For example, the team would like to discern at what age subtle difficulties first appear in AgCC individuals, and at what point they start looking similar to autism, as well as what happens in the brain during these changes.

"If we could follow a baby with AgCC as it grows up, and visualize its brain with MRI each year, we would gain such a wealth of knowledge," Adolphs says.

The Brain paper, "Agenesis of the Corpus Callosum and Autism: A Comprehensive Comparison," also includes as coauthors Daniel Kennedy, assistant professor of psychology at Indiana University, and Christina Corsello, a member of the research staff at Rady Children's HospitalSan Diego. The research was funded by the Simons Foundation, Autism Speaks, and the Brain and Behavior Research Foundation.

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On the Front Lines of Sustainability

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On the Front Lines of Sustainability
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The chemical processes used to make products ranging from pharmaceuticals to perfumes can have a harmful impact on the environment. However, Caltech chemist and Nobel laureate Robert Grubbs has spent several decades developing catalysts—compounds that speed up a chemical reaction—that can make the synthesis of these products more efficient and ecologically friendly, ultimately reducing their environmental footprint. Similarly, chemist Brian Stoltz is developing new strategies for the synthesis of compounds needed in the chemical, polymer, and pharmaceutical industries. His new processes rely upon oxygen and organometallic catalysts—greener alternatives to the toxic metals that are normally used to drive such reactions.

Switching from paper files to cloud-based data storage might seem like an obvious choice for sustainability, but can we further reduce the environmental impact of storing data? The theoretical work of engineer and computer scientist Adam Wierman suggests that with the right algorithms, we can. Today, data centers—the physical storage facilities Wierman calls the "SUVs of the Internet"—account for more than 1.5 percent of U.S. electricity usage. And as more data goes online, that number is expected to grow. Wierman's work helps engineers design algorithms that will reroute data, with preference to centers that use renewable energy sources like wind and solar.

Energy from the sun—although free and abundant—cannot easily be stored for use on dreary days or transported to cloudy regions. Caltech engineer and materials scientist Sossina Haile hopes to remove that barrier with a specific type of solar reactor she has developed. The reactor is lined with ceramic cerium oxide; when this lining is heated with concentrated sunlight it releases oxygen, priming it to remove oxygen from water molecules or carbon dioxide on cooling, thus creating hydrogen fuel or "syngas"—a precursor to liquid hydrocarbon fuels. This conversion of the sun's light into storable fuel could allow solar-derived power to be available day and night.

Caltech student participants in the Department of Energy's biennial Solar Decathlon competition set out to prove that keeping a house lit up, cooled down, and comfortable for living is possible—even while off the grid. The Techers teamed up with students at the Southern California Institute of Architecture to create CHIP and DALE, their entries in the 2011 and 2013 competitions, respectively. These functional and stylish homes, powered solely by the sun, were engineered with innovative components including a rainwater collection system and moving room modules that optimize heating and cooling efficiency. 

Although many of us take the nearest bathroom for granted, working toilets require resources and infrastructure that may not be available in many parts of the world. Inspired by the "Reinventing the Toilet Challenge" issued by the Bill and Melinda Gates Foundation, environmental scientist and engineer Michael Hoffmann and his team applied his research in hydrogen evolution and water treatment to reengineer the toilet. The Caltech team's design—which won the challenge in 2012—can serve hundreds of people each day, treat its own wastewater, and generate electricity, providing a sustainable and low-cost solution to sanitation and hygiene challenges in the developing world. Prototypes are being tested in India and China for use in urban and remote environments in the developing world.  

Geophysicist Mark Simons studies the mechanics of the Earth—furthering our understanding of what causes our planet to deform over time. His research often involves using satellite data to observe the movement associated with seismic and volcanic activity, but Simons is also interested in changes going on in the icy parts of Earth's surface, especially the dynamics of glaciers. By flying high above Iceland's ice caps, Simons and his colleagues can track the glaciers' melt-and-freeze response in relation to seasonal and long-term variations in temperature—and their potential response to climate change.

The production of industrial nitrogen fertilizer results in 130 million tons of ammonia annually—while also requiring high heat, high pressure, and lots of energy. However, in a process called nitrogen fixation, soil microorganisms that live near the roots of certain plants can produce a similar amount of ammonia each year. The bugs use catalysts called nitrogenases to convert nitrogen from the air into ammonia at room temperature and atmospheric pressure. By mimicking the behavior of these microorganisms, Jonas Peters and his colleagues synthesized an iron-based catalyst that allows for nitrogen fixation under much milder conditions. The catalyst could one day lead to more environmentally friendly methods of ammonia production.

Traditionally, the photovoltaic cells in solar panels have been expensive and have had limited efficiency—making them a hard sell in the consumer market. Engineer and applied physicist Harry Atwater's work suggests that there is a thinner and more efficient alternative. Atwater, who is also the director of the Resnick Sustainability Institute, uses thin layers of semiconductors to create photovoltaics that absorb sunlight as efficiently as thick solar cells but can be produced with higher efficiency than conventional cells.

The generation of chemical fuels from sunlight could completely change the way we power the planet. Researchers in the laboratory of Caltech chemist Nate Lewis are working to develop different components of a fuel-producing device that could do just that called a photoelectrochemical cell. The cell would consist of an upper layer that could absorb sunlight, carbon dioxide, and water vapor, a middle layer consisting of light absorbers and catalysts that can produce fuels, which are then released through the device's bottom layer. When such a device is created, the Joint Center for Artificial Photosynthesis, of which Lewis is the scientific director, aims to ease the transfer of these technologies to the private sector. 

Clean energy from the wind is a promising alternative to fossil fuels, but giant pinwheel-like wind turbines that are common on many wind farms can create dangerous obstacles for birds as well as being an unpleasant addition to a landscape's aesthetic. To combat this problem, Caltech engineer and fluid-mechanics expert John Dabiri is testing a new design for wind turbines, which looks a bit like a spinning eggbeater emerging from the ground. By placing these columnar vertical wind turbines in a careful arrangement—an arrangement inspired by the vortex of water created behind a swimming fish—his smaller vertical turbines create just as much energy as the "pinwheels" and on a much smaller land footprint.

In the early 1990s, Caltech bioengineer Frances Arnold pioneered "directed evolution"—a new method of engineering custom-built enzymes, or activity-boosting proteins. The technique allows mutations to develop in the enzyme's genetic code; these mutations can give the enzyme properties that don't occur in nature but are beneficial for human applications. The selectively enhanced enzymes help microbes turn plant waste and fast-growing grasses into fuels like isobutanol, which could sustainably replace more than half of U.S. oil imports, Arnold says. She's also exploring ways the technique could help factories to make pharmaceuticals and other products in much cleaner and safer ways.

The combined research efforts of Richard Flagan, John Seinfeld, Mitchio Okumura, and Paul Wennberg aim to improve our understanding of various aspects of climate change. Chemical engineer Flagan is pioneering ways to measure the number and sizes of particles in the air down to that of large molecules. Seinfeld studies where particles in the air come from, how they are produced by airborne chemical reactions, and the effect they have on the world's climate. Chemical physicist Okumura studies the chemical reactions that occur when sunlight encounters air pollution and results in smog. Wennberg, an atmospheric chemist, studies the natural and human processes that affect smog formation, the health of the ozone layer, as well as the lifetime of greenhouse gases. Wennberg and his colleagues join a legacy of Caltech researchers who have improved air quality through key discoveries about pollution.

In the past, researchers have discovered materials that can act as reaction catalysts, driving sunlight to split water into hydrogen fuel and an oxygen byproduct. However, these wonder materials are often expensive and in short supply. The research of chemist Harry Gray, who leads the National Science Foundation-funded Center for Chemical Innovation in Solar Fuels program, tests combinations of Earth-abundant metals to search for an inexpensive catalyst that boosts the water-splitting reaction with the sun. Gray also coleads an outreach project in which students in the classroom can participate in the race for solar fuels by testing thousands of materials and reporting their results to Caltech researchers.

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Although Earth Week has officially come to a close, Caltech's commitment to sustainability continues. In this feature, you will meet some of the researchers at Caltech whose work is contributing to a greener planet and to the long-term improvement of our global environment.

Spring Break in the Galápagos

 

As the final element of Evolution, Caltech's new Bi/Ge 105 course, a dozen students spent their spring break snorkeling with penguins and sharks, hiking a volcano, and otherwise taking in the natural laboratory for evolution that is the Galápagos Islands. The second-term course was created and is taught by Rob Phillips, the Fred and Nancy Morris Professor of Biophysics and Biology, and Victoria Orphan, professor of geobiology, and is designed to give students both a broad picture of evolution and a chance to make their own up-close-and-personal observations.

"Rob and I both feel very strongly that lab and field experiences are essential for the growth of the students as scientists," Orphan says. "Being at a place like Caltech that's small and where you have a lot of talented and enthusiastic students is the perfect environment to create those kinds of opportunities."

So with their trusty mascot—a bobblehead Darwin—in tow, the undergraduate students, their teaching assistant, and the two professors flew to Ecuador and then to the archipelago off the coast to spend a week living as field researchers and learning from Ecuadorian naturalist Ernesto Vaca and from their natural surroundings.

"The Galápagos are completely iconic," says Phillips. "Right before your eyes you can see the products of evolution, if you like. You can swim in the water with the flightless cormorants. The famed Darwin's finches are there. You can wonder what penguins are doing at the equator. What especially impresses me about seeing species such as the cormorants is the way they teach us about some of the most important evolutionary features seen on islands, such as dwarfism, gigantism, and flightlessness."

During the trip, each student made a presentation to the group, discussing a species or topic specific to the islands. One spoke about the Galápagos fur seal; another presented about the opuntia, a variety of cactus; another about marine iguanas. Senior bioengineering major Laura Santoso spoke about invasive species on the island. She says that although she had researched the subject extensively ahead of time, she saw things differently once she was actually in the Galápagos. For example, she had read that a particular invasive insect had been essentially eradicated from the islands, but while there she actually saw a number of the bugs. "It drove home how challenging it is to get rid of these invasive species," she says. "I find that observing the complexity of the issue in person and developing my own inferences makes it more meaningful."

Junior bioengineering major Aleena Patel agrees, adding that the trip suggested new ways to ask questions, to study, and to explore. "Being there in person piques curiosity in ways that other facets of learning don't," she says. "At times, there was so much to see it was almost overwhelming. But as scientists, we need that inspiration to ask questions and to be emotionally motivated."

That is just the kind of motivation Phillips and Orphan hoped to impart. "My view is that the most important point is to get students to plug into the idea of looking at nature and wondering, 'Why is that like that? How could science attack that question?' It's not so much a course about learning what is," says Phillips. "It's a course about saying, 'I wonder . . .'"

In addition to the Galápagos trip, the class took smaller day trips closer to campus during the winter term. On a special behind-the-scenes tour of the Page Museum at the La Brea Tar Pits, they were able to collect samples from one of the current excavations in order to study the microbes that make a living in such a unique environment. They also visited the Moore Lab of Zoology at Occidental College, where they used calipers to measure beaks in one of the world's largest collections of Mexican birds. The goal of the exercise was to get a feel for the kinds of measurements that biologists have conducted on finches on Daphne Major, one of the islands of the Galápagos, to study evolution in action.

The new class was supported by Caltech's Innovation in Education Fund, the Division of Geological and Planetary Sciences, and the Division of Biology and Biological Engineering through its William K. Bowes Jr. Leadership fund. As for why its focus was evolution, Orphan explains, "Evolution is of course integral to anyone doing biology. But when you start to look around, you find that evolution has its tendrils in a lot of different areas of research beyond biological research—even in computer science. We wanted to give the students that perspective, that even if they weren't going to be evolutionary biologists, per se, that the concepts and the way of perceiving the world in this class were going to help them."

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Spring Break in the Galapagos
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Unlocking a Mystery of Human Disease . . . in Space

An experiment just launched into orbit by a team of Caltech researchers could be an important step toward understanding a devastating neurodegenerative disease.

Huntington's disease is a grim diagnosis. A hereditary disorder with debilitating physical and cognitive symptoms, the disease usually robs adult patients of their ability to walk, balance, and speak. More than 15 years ago, researchers revealed the disorder's likely cause—an abnormal version of the protein huntingtin; however, the mutant protein's mechanism is poorly understood, and the disease remains untreatable.

Now, a new project led by Pamela Bjorkman, Max Delbrück Professor of Biology, will investigate whether the huntingtin protein can form crystals in microgravity aboard the International Space Station (ISS)—crystals that are crucial for understanding the molecular structure of the protein. The experiment was launched from Cape Canaveral in Florida on Friday, April 18 aboard the SpaceX CRS-3 cargo resupply mission to the ISS. On Sunday, April 20 the station's robotic arm captured the mission's payload, which included the proteins for Bjorkman's experiment—which is the first Caltech experiment to take place aboard the ISS.

In the experiment, the researchers hope to grow a crystal of the huntingtin protein—the crystal would be an organized, latticelike arrangement of the protein's molecules—which is needed to determine the molecular structure of the protein. However, molecules of the huntingtin protein tend to aggregate, or clump together, in Earth's gravity. And this disordered arrangement makes it incredibly hard to parse the protein's structure, says Gwen Owens, a graduate student in Bjorkman's lab and a researcher who helped design the study.

"We need crystals for X-ray crystallography, the technique we use to study the protein, in which we shoot an X-ray through the protein crystal and analyze the organized pattern of radiation that scatters off of it," Owens says. "That pattern is what we depend on to identify the location of every carbon, nitrogen, and sulfur atom within the protein; if we shoot an X-ray beam at a clumped, aggregate protein—like huntingtin often is—we can't get any data from it," she says.

Researchers have previously studied small fragments of crystallized huntingtin, but because of its large size and propensity to clumping, no one has ever successfully grown a crystal of the full-length protein large enough to analyze with X-ray crystallography. To understand what the protein does—and how defects in it lead to the symptoms of Huntington's disease—the researchers need to study the full-length protein.

Looking for a solution to this problem, Owens was inspired by a few previous studies of protein formation on space shuttles and the ISS—studies suggesting that proteins can form crystals more readily in a condition of near-weightlessness called microgravity. "The previous studies looked at much simpler proteins, but we thought we could make a pretty good case that huntingtin would be an excellent candidate to study on the ISS," Owens says.

They proposed such an experiment to the Center for the Advancement of Science in Space (CASIS), which manages U.S. research on the ISS, and it was accepted, becoming part of the first Advancing Research Knowledge, or ARK1, mission.

Because Owens and Bjorkman cannot travel with their proteins, and staff and resources are limited aboard the ISS, the crystal will be grown with a Handheld High-Density Protein Crystal Growth device—an apparatus that will allow astronauts to initiate growth of normal and mutant huntingtin protein crystals from a solution of protein molecules with just the flip of a switch.

As the crystals grow larger over a period of several months, samples will come back to Earth via the SpaceX CRS-4 return mission. The results of the experiment are scheduled to drop into the ocean just off the coast of Southern California—along with the rest of the return cargo—sometime this fall. At that point, Owens will finally be able to analyze the proteins.

"Our ideal result would be to have large crystals of the normal and mutant huntingtin proteins right away—on the first try," she says. After analyzing crystals of the full-length protein with X-ray crystallography, the researchers could finally determine huntingtin's structure—information that will be crucial to developing treatments for Huntington's disease.

Owens, a joint MD/PhD student at Caltech and UCLA's David Geffen School of Medicine, has also had the opportunity to work with Huntington's disease patients in the clinic, adding a human connection to her experiment in the sky. "The patients and families I have met who are affected by Huntington's disease are excited to see something big like this. It's inspiring for them—and hopefully it will inspire new research, too."

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Monday, May 5, 2014
Center for Student Services 360 (Workshop Space)

Experiences from two years of MOOCs at Caltech: A WEST Public Seminar

John Dabiri Named Dean of Undergraduate Students

Starting on July 1, 2014, John Dabiri, professor of aeronautics and bioengineering, will serve as Caltech's dean of undergraduate students.

"John is particularly committed to enhancing faculty-student interactions. His experience as chair of the faculty and as faculty in residence in Avery House make me confident he will do a great job," says Anneila Sargent, vice president for student affairs and the Ira S. Bowen Professor of Astronomy.

The role of dean of undergraduate students is to foster academic and personal growth through counseling and support for student activities as well as act as a liaison between students and faculty.

"I've been fortunate to interact with Caltech undergrads as a visiting SURF student, a graduate student, and as a professor," says Dabiri. "Those experiences have proven to me that the creative and maverick spirit that is the Caltech brand really begins with our undergrads, and I look forward to helping nurture that spirit."

Dabiri says that his first order of business as dean is to engage students in a conversation about their experience on campus.

"I'm looking forward to visiting each of the houses this term to solicit their feedback on student life at Caltech," says Dabiri, who lives with his family in Avery House as faculty in residence.

He also wants to include former students in talks about how to improve undergraduate life at Caltech.

"Our alumni provide a longer-term perspective that will be a valuable complement to student input, and I hope they won't be shy in providing it," says Dabiri. "I also want to challenge our esteemed alumni and other friends to invest the time and resources needed to ensure that the student experience at Caltech is unparalleled in terms of the opportunities it affords for academic and personal development."

He cites greater exposure to entrepreneurship and the arts as examples of important complements to the existing Caltech education.

Dabiri, who is currently chair of the faculty, will take the reins from Rod Kiewiet, professor of political science, who began his term as dean of undergraduate students in July 2011.

"It's essential that we continue the important work Dean Kiewiet has initiated in developing a comprehensive social safety net within the house system," says Dabiri. "I'm also eager to receive the recommendations of the ongoing ad hoc committee on undergraduate self-governance, which should provide our students with greater opportunities to develop leadership skills through management of the houses."

Dabiri received his undergraduate degree in mechanical and aerospace engineering from Princeton University in 2001. He earned both his MS ('03) in aeronautics and PhD ('05) in bioengineering from Caltech, joining the faculty upon completion of his doctoral studies in 2005. A 2010 MacArthur Fellow, he is director of Caltech's Biological Propulsion Laboratory.  

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