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SUNMONTUEWEDTHUFRISAT
Conferences, Lectures, & Seminars
Events for December
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Engineered self-assembly for ion channel protein-based molecular sensors
Fri, Dec 01, 2006 @ 11:00 AM
Mork Family Department of Chemical Engineering and Materials Science
Conferences, Lectures, & Seminars
Graduate Seminar
Engineered self-assembly for ion channel protein-based molecular sensorsDr. Noah MalmstadtPostdoctoral Scholar
University of California at Los AngelesAbstract
There has been much recent interest in using channel proteins as the basis of new
chemical detection technologies, including molecular sensing and single-molecule DNA
sequencing; these proteins are also important drug targets. Ion channel measurements are
performed by incorporating proteins into lipid bilayer membranes; however, these 5 nm-thick
membranes are fragile, short-lived, and labor-intensive to fabricate. These shortcomings
greatly limit the use of ion channel proteins in engineered devices.
We have developed two novel technologies that address these shortcomings: In the
first, we have encapsulated lipid bilayer membranes within a hydrogel network. This
encapsulation process, in which a hydrogel is polymerized in situ around a self-assembled
lipid bilayer, results in membranes that are robust to mechanical perturbation and that last
over ten times longer than the previous state of the art. Hydrogel-encapsulated membranes
can support extended measurements of ion channel proteins at the single-molecule level,
and have the potential to enable long-lived ion channel sensors in portable devices. Our
second novel technology is a microfluidic system for automated membrane fabrication and
measurement. This system controls and automates the process of membrane self-assembly
through material-driven solvent extraction from a multiphase droplet flow. Ion channel
proteins can be incorporated in these membranes and measured with single-molecule
resolution. This on-demand bilayer fabrication technology can form the basis of membrane
arrays for high throughput sensing for chemical detection as well as drug discovery and
screening. These technologies provide two complementary pathways to the development of
devices in which channel proteins serve as active nanoscale sensing elements.Friday, December 1, 2006
Seminar at 11:00 a.m.
HED 116
The Scientific Community is Cordially Invited to Attend.Location: Hedco Pertroleum and Chemical Engineering Building (HED) - 116
Audiences: Everyone Is Invited
Contact: Petra Pearce
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Eli Yablonovitch
Fri, Dec 01, 2006 @ 11:00 AM - 12:00 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
University of California, Los AngelesEngineering design is sometimes inspired by Nature. The natural world is filled with crystals, periodic structures that interact with electron waves. Drawing on this analogy, photonic crystals are artificial periodic structures that are intended for electromagnetic waves, instead. Such nano-photonic structures are now being designed and patterned into Silicon-on-Insulator (SOI) to provide for commercial nano-photonic integration, as a component part of conventional CMOS circuits.Further optical frequency miniaturization will take us toward nano-plasmonics, metallic-wired electrical circuits, running at optical frequencies. At lower frequencies, new electronic switching devices that have a sub-threshold slope steeper than kT/q are expected to emerge. The research of the next 10 years will answer what comes after the semiconductor roadmap.
Location: Hedco Neurosciences Building (HNB) - 100
Audiences: Everyone Is Invited
Contact: Ericka Lieberknecht
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Unraveling Bacterial Mn(II) Oxidation
Fri, Dec 01, 2006 @ 01:00 PM - 02:00 AM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speakers:Hope A. Johnson and Bradley M. TeboThe Scripps Research Institute
La Jolla, CAAbstract
It is important to understand the fundamental mechanism of bacterial manganese(II) oxidation because it plays a role in many biogeochemical cycles and can be utilized for bioremediation. Prior work with Mn(II)-oxidizing bacteria has suggested that Mn(II) oxidation involves a multicopper oxidase, but whether this enzyme directly catalyzes Mn(II) oxidation is unknown. For a clearer understanding of microbial Mn(II) oxidation, we have undertaken biochemical studies in the model marine -proteobacterium, Erythrobacter sp. strain SD21. In vitro experiments with this strain showed the Mn(II)-oxidizing activity to be protein dependent. The optimum pH for activity was 8.0 with a specific activity of 2.5 nmol/min/mg and a Km = 204 µM. The activity is soluble which may suggest a cytoplasmic or periplasmic protein. Mn(III) is an intermediate in the oxidation of Mn(II) and likely the primary product of enzymatic oxidation by this organism. The activity is stimulated by calcium, but is not stimulated by copper in vivo or in vitro. Surprisingly, the activity was enhanced by pyrroloquinoline quinone (PQQ) and NAD+. PQQ could also rescue Pseudomonas putida MnB1 non-Mn(II)-oxidizing mutants with insertions in the anthranilate synthase gene. Partially purified Mn(II) oxidase was significantly enriched in quinones and had a UV/VIS absorption spectrum similar to a known quinoprotein but not to known multicopper oxidases, suggesting that quinones may play an integral role in bacterial Mn(II) oxidation. In addition to investigating enzymes involved in Mn(II) oxidation in laboratory model strains, we have also assayed and directly identified enzymes from the environment.Location: Kaprielian Hall (KAP) - rielian Hall, Room 203
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Water in Green Manufacturing: The Next Frontier
Fri, Dec 01, 2006 @ 01:00 PM - 02:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker:Azita Yazdani, P.E.
President and CEO
Exergy Technologies Corporation
25 Mauchly, Suite 316, Irvine CA 92618
Phone: 949-231-1390
Fax: 949-757-2715Abstract:Water is the most important raw material in terms of quality and quantity used in many manufacturing processes. An average process bath is made of at least 80% water, followed by most process steps that use one or more water rinses. Water can solve and cause many problems in production. Manufacturing plants spend millions of dollar each year to remove impurities before the water used in their processes is acceptable for use. Additionally, water quality plays an important role in ensuring process performance and quality of product.Membrane technologies can play an important role in delivering acceptable water quality to many processes. Today, these technologies also show promise for recycle and reuse applications of both water and process chemicals. Various membrane and electro-membrane technologies can provide and maintain high quality water and chemicals for process applications. These technologies help companies reduce the cost and operational downtimes experienced by the manufacturing processes by making reuse and recycling cost effective.Location: Kaprielian Hall (KAP) - rielian Hall 156
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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Waveguiding in Periodic Coupled Micro-resonator
Mon, Dec 04, 2006 @ 10:00 AM - 11:00 AM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Joyce PoonCalifornia Institute of TechnologyAbstract:
Coupled-Resonator Optical Waveguides (CROWs) are chains of resonators in which light propagates by virtue of the coupling between the resonators. The dispersive properties of these waveguides are controllable by the inter-resonator coupling and the geometry of the resonators. For example, if the inter-resonator coupling is weak, light can be engineered to propagate slowly in CROWs. The small group velocities possible in CROWs may enable applications in and technologies for optical delay lines, interferometers, buffers, nonlinear optics, and lasers. In this presentation, I will report on our progress in achieving and controlling optical delay in passive and active CROWs. Both theoretical and experimental results will be presented. I will show how transfer matrices can be used to analyze and design a variety of coupled resonator systems. I will also present measurements of the spectral and group delay properties of high-order (>10) coupled polymer microring resonators. Finally, I will discuss our ongoing work on active CROWs in III-V semiconductors for loss compensation and electrical control.Brief Biography:
Joyce Poon is a Ph.D. candidate in Electrical Engineering at the California Institute of Technology (Caltech) in the group of Prof. Amnon Yariv. She received the M.S. in Electrical Engineering in 2003 from Caltech and the B.A.Sc. in Engineering Science (Physics Option) from the University of Toronto in 2002. She is grateful for fellowships from the Natural Science and Engineering Research Council of Canada (NSERC), OSA Dekker Foundation, and IEEE-LEOS for supporting her graduate studies. Joyce's current research is on slow light propagation in coupled resonators, polymer microrings, and compound semiconductor (InP-InGaAsP) resonator devices. Her research interests include the theory, design, and experimental studies of optical wave propagation in waveguides, micro-resonators, and periodic structures for active and passive photonics.
Location: Hedco Neurosciences Building (HNB) - 100
Audiences: Everyone Is Invited
Contact: Ericka Lieberknecht
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Quantum Network Communication -- The Butterfly and Beyond
Mon, Dec 04, 2006 @ 11:00 AM - 12:00 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
SPEAKER: Prof. Debbie Leung, University of WaterlooABSTRACT: We study the communication of quantum information in networks of (directed) quantum channels. We consider the asymptotic rates of high fidelity quantum communication between specific sender-receiver pairs. In networks that are shadow, we find that rerouting of quantum information is optimal. Consequently, the achievable rate regions are given by counting edge avoiding paths, and precise achievable rate regions can be obtained. Slight twists to the above results are obtained when side classical channels are available. These complete solutions apply to many networks, including the butterfly network.Joint work with Jonathan Oppenheim and Andreas WinterBio: After a B.S. in Ph/Ma from Caltech in 1995, Debbie completed a PhD on Robust quantum computation at Stanford in 2000 under the supervision of Prof. Yoshihisa Yamamoto and Prof. Isaac Chuang. She then worked at IBM TJ Watson Research Center in 2000-2002, MSRI in 2002, and Caltech in 2003-2005 on quantum communication and cryptography. She joined the Institute for Quantum Computing and the Department of Combinatorics and Optimization at the University of Waterloo in 2005.Host: Prof. Igor Devetak, devetak@usc.edu
Location: Frank R. Seaver Science Center (SSC) - 319
Audiences: Everyone Is Invited
Contact: Mayumi Thrasher
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Protocols for Adaptive Modulation and Coding in Dynamic Spectrum Access Networks
Tue, Dec 05, 2006 @ 11:00 AM - 12:30 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
SPEAKER: Michael B. Pursley, Holcombe Professor, Clemson UniversityABSTRACT: A protocol suite is presented for controlling transmissions in dynamic spectrum access networks. A framework is provided for the selection of the initial modulation to be used in a session after a frequency band has been designated. During the first few packet transmissions in a new session, a power-adjustment protocol compensates for uncertainties in the propagation characteristics and interference in the designated frequency band. Throughout the session, the error-control code and modulation are adapted to accommodate time-varying interference and propagation loss. Because increases in transmitter power can disrupt other sessions that are underway in the network, the transmitter power is increased only if adaptation of coding and modulation cannot compensate fully for deteriorations in the channel conditions. Protocol performance results are provided for static channels with unknown characteristics and for dynamic channels that are modeled as finite-state Markov chains. Comparisons with Shannon capacity limits are employed to assess the efficiency of the adaptive coding protocol for a wide range of modulation techniques and channel models.Host: Prof. Robert Scholtz, scholtz@usc.edu
Location: Hughes Aircraft Electrical Engineering Center (EEB) - 248
Audiences: Everyone Is Invited
Contact: Mayumi Thrasher
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USC CS Colloquium Lecture Series
Tue, Dec 05, 2006 @ 03:30 PM - 05:00 PM
Thomas Lord Department of Computer Science
Conferences, Lectures, & Seminars
An Zhu
GoogleTitle: Towards Achieving Anonymity Abstract:We study the problem of publishing data from a table containing personal data, in a privacy preserving manner. In particular, we aim to anonymize quasi-identifiers, i.e., non-key attributes that combinedly identifiy a unique record in the table.The first model is proposed by Sweeney, called k-anonymity. This approach suppresses some values of the quasi-identifiers, such that for every record in the modified table, there are at least k-1 other records with exactly the same value. And the quality measure here is the number of quasi-identifier values suppressed. We provide a O(k)-approximation algorithm for this problem, improving upon the previous O(k log k) result. We also show that this is the best approximation bound possible using the distance representation. For small values of k, we provide improved bounds as well.We propose a second model which generalizes the quasi-identifier values via clustering. The records are first clustered and then the cluster centers are published. To ensure privacy, we impose the constraint that each cluster must contain at least k records. We consider the measure of minimizing the maximum cluster radius, for which we provide a tight 2-approximation algorithm. The second measure concerns minimizing the sum, over all clusters, the product of number of records per cluster and the cluster radius. For this measure we also provide a constant approximation algorithm. Further, we extend the algorithms to handle the case where we can omit outliners.This talk is based on two papers:
Anonymizing Tables (ICDT 05), coauthored with Aggarwal, Feder, Kenthapadi, Motwani, Panigrahy, and Thomas.
Achieveing Anonymity via Clustering (PODS 06), coauthored with Aggrawal, Feder, Kenthapadi, Khuller, Panigrahy, and Thomas.Bio:
An obtained her phd from Stanford University in 2004, under the supervision of Rajeev Motwani and Leo Guibas. An joined Google after her graduation. Since then, An has been involved in a variety of projects at Google, including search quality/ranking, image search, scholar search, and search infrastructureLocation: Seaver Science Library (SSL) - 150
Audiences: Everyone Is Invited
Contact: Nancy Levien
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Spectrum Sharing: System Design Perspective
Wed, Dec 06, 2006 @ 03:00 PM - 04:00 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Speaker: Danijela CabricUniversity of California, BerkeleyA major shift in wireless communications is now emerging with the development of cognitive radios, which attempt to share spectrum in a fundamentally new way. Cognitive radios address the problem of poor spectrum utilization exhibited in many frequency bands. On a conceptual level, cognitive radio networks sense the spectral environment and adapt transmission parameters to dynamically reuse available spectrum. The novelty of this approach requires us to re-architect the mechanisms for using radio frequencies and find a way for multiple systems to co-exist through sharing rather than fixed allocations.This talk addresses fundamental questions in cognitive radios system design and investigates its feasibility by bridging the theoretical and practical aspects of the physical and network layers. We begin with spectrum sensing, the key enabling functionality for cognitive radios, which requires detection of very weak signals of different types in a minimum time with high reliability. We show that the biggest barrier for sensing in very low signal to noise ratio regimes is the variability in the noise and interference that cannot be perfectly calibrated during sensing time. Robustness can be increased by differentiating signals from noise by detecting signal features or by exploiting channel diversity with network cooperation. Through physical implementation and experiments of proposed sensing methods, we identify the minimum possible sensing times and detectable signal levels. Moreover, we include the sensitivities exhibited by these methods to radio and channel impairments. Next, we consider radio architecture for wideband spectrum sharing radios and show that large dynamic range requirements present major challenge in their implementation. This calls for the development of novel mixed signal techniques. By exploiting spatial dimension for selective processing of desired signals through antenna array architectures, strong interferers can be adaptively suppressed. We conclude with a discussion of the requirements for the signaling and protocol designs that support dynamic spectrum access and spectrum sensing coordination.Brief Biography:
Danijela Cabric is a Ph.D. candidate in Electrical Engineering at the University of California, Berkeley in the group of Prof. Robert Brodersen. She received the M.S. in Wireless Communications and VLSI System Design in 2001 from the University of California at Los Angeles and the Diploma in Electrical Engineering from the University of Belgrade, Serbia, in 1998.
Location: Hedco Neurosciences Building (HNB) - 100
Audiences: Everyone Is Invited
Contact: Ericka Lieberknecht
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Dynamics of nonlinear coupled nanomechanical resonators
Wed, Dec 06, 2006 @ 03:30 PM - 04:30 PM
Aerospace and Mechanical Engineering
Conferences, Lectures, & Seminars
Ron LifshitSchool of Physics and Astronomy,Tel Aviv University (Currently on sabbatical leave at the California Institute of Technology) Abstract:We are studying the dynamics of nonlinear coupled oscillators,
motivated by recent experiments with arrays of micromechanical and nanomechanical resonators at Caltech and Cornell. We have obtained exact results for the parametric excitation of small arrays using secular perturbation theory [1], as well as an amplitude equation to describe the slow dynamics of the parametric excitation of large arrays [2]. I will focus on these results to explain the intricate experimentally-observed response curves, and to suggest further experiments. If time permits, I will say a few words about our model of synchronization, which is based on reactive coupling and nonlinear frequency pulling [3,4] (rather
than the more common linear dissipative models). [1] Lifshitz and Cross, PRB 67 (2003) 134302;[2] Bromberg, Cross, and Lifshitz, PRE 73 (2006) 016214;[3] Cross, Zumdieck, Lifshitz, and Rogers, PRL 93 (2004) 224101;[4] Cross, Rogers, Lifshitz, and Zumdieck, PRE 73 (2006) 036205.Location: Stauffer Science Lecture Hall (SLH), Room 100
Audiences: Everyone Is Invited
Contact: April Mundy
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Teaching Silicon New Tricks
Thu, Dec 07, 2006 @ 12:00 PM - 01:00 PM
Ming Hsieh Department of Electrical and Computer Engineering
Conferences, Lectures, & Seminars
Bahram JalaliUniversity of California, Los AngelesAbstract:
Conventional wisdom holds that silicon cannot amplify light and what's worse, it has no useful nonlinearities so it cannot manipulate light. Taking this axiom as a motivation rather than a deterrent, several research groups, including mine, have been on a crusade to prove it wrong and to unleash the mighty silicon photonics technology. We've been partially successful! This talk will elucidate the relevant physics that determines silicon's prospect as an active optical medium. It will review the recent breakthroughs based on nonlinear optics in silicon, including optical amplification, lasing, wavelength conversion, energy harvesting, and a new class of devices based on nonlinear optics in multi-mode waveguides. It will close with a previously unforeseen, yet exciting application of silicon photonics: THz real-time analog-to-digital conversion.Biography:
Bahram Jalali is a Professor of Electrical Engineering, the and the Director of the Optoelectronic Circuits and System Laboratory at UCLA. From 1988-1992, he was a Member of Technical Staff at the Physics Research Division of AT&T Bell Laboratories in Murray Hill, N.J. where he conducted research on ultrafast electronics and optoelectronics. His current research interests are in silicon photonics and ultrafast photonic signal processing.Dr. Jalali has published over 200 scientific papers in and holds 6 US patents. He is a Fellow of IEEE and of Optical Society of America (OSA) and the Chair of the Los Angeles Chapter of the IEEE Lasers and Electro Optics Society (LEOS). In 2005, he was chosen by the Scientific American Magazine as the 50 Leaders Shaping the Future of Technology. He is a member of the California Nano Systems Institute (CNSI).While on leave from UCLA from 1999-2001, Dr. Jalali founded Cognet Microsystems, a Los Angeles based fiber optic component company. He served as Company's CEO, President and Chairman, from the company's inception through its acquisition by Intel Corporation in April 2001. He has received the BridgeGate 20 Award for his contribution to the southern California economy. From 2001-2004, he served as a consultant to Intel Corporation. Dr. Jalali serves on the Board of Trustees of the California Science Center.
Location: Hedco Neurosciences Building (HNB) - 100
Audiences: Everyone Is Invited
Contact: Ericka Lieberknecht
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Robotics at Microsoft
Tue, Dec 12, 2006 @ 12:00 PM - 01:00 PM
Thomas Lord Department of Computer Science
Conferences, Lectures, & Seminars
Dr. Stewart TansleyMicrosoft ResearchTitle:
Robotics at Microsoft -- A Personal Journey & PerspectiveAbstract:
Three years ago, Microsoft's answer to roboticists was "Have you tried Windows CE? It's hard real-time you know!". Today, in Fall 2006, we have an entire dedicated software platform for robotics researchers, companies, and hobbyists, and a leading academic program to help make robotics in computer science education a potentially pervasive experience across the US and beyond. This talk will try to explain how this happened, what is available for roboticists today, and where things are going -- from the perspective of one of those at the center of these exciting developments. While very much a personal perspective, attendees at the talk will hopefully gain a better understanding of Microsoft, its relationship with academia via Microsoft Research in particular, and what it means to make a difference as one person in over 70,000.Bio:
Stewart is responsible for Embedded Systems and Robotics as part of External Research & Programs in Microsoft Research. Before this, he worked on Microsoft's production IPv6 software as part of the Windows Networking team. Prior to joining Microsoft in 2001, Stewart spent 13 years in the telecommunications industry in various technical and management positions in network software research and development, focusing on technology transfer. Stewart has a Ph.D. in Artificial Intelligence applied to Engineering from the University of Technology, Loughborough, UK. He has published a variety of papers in artificial intelligence and network management, several patents, and co-authored a book on software engineering for artificial intelligence applications.Web:
http://research.microsoft.com/~stansley/Hosted by Maja Mataric'Location: Seaver Science Library (SSL) - 150
Audiences: Everyone Is Invited
Contact: Nancy Levien
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Random vibrations and peak response of a shear beam under high frequency seismic effects
Wed, Dec 13, 2006 @ 03:00 PM - 04:00 PM
Sonny Astani Department of Civil and Environmental Engineering
Conferences, Lectures, & Seminars
Speaker:Prof. Zbigniew Zembaty
Faculty of Civil Eng., Opole University of Technology
45-271 Opole, ul. Mikolajczyka 5, POLAND
Location: Kaprielian Hall (KAP) - 203
Audiences: Everyone Is Invited
Contact: Evangeline Reyes
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3D Direct Numerical Simulations of Autoigntion in Turbulent Non-Premixed Flows with 1-Step and Reduc
Wed, Dec 13, 2006 @ 03:30 PM - 04:30 PM
Aerospace and Mechanical Engineering
Conferences, Lectures, & Seminars
Dr. Terese Løvas,Lecturer in Future Energy Conversion TechnologiesDepartment of Engineering,
Queen Mary University of London, UKAbstractThe autoignition of non-premixed flows is important for diesel and Homogenous Charge Compression Ignition (HCCI) engines, and it is also now a concern in the new lean premixed pre-vapourised (LPP) gas turbines. Because typically in diesel engines the ignition time is longer than an estimated turbulent timescale, the common understanding until early 1990's was that the ignition is not affected by the turbulence, but that is purely driven by the chemistry. However, it was later recognised that turbulence may affect the ignition time and the subsequent flame development significantly. Deeper knowledge of how the fluid mechanics affect autoignition will assist the design of the low-polluting HCCI engines and the new LPP gas turbines.
In the talk results from a set of 3D Direct Numerical Simulations (DNS) of autoignition in turbulent non-premixed flows will be discussed. Both a simple 1-step mechanism and a complex chemistry consisting of a 22 species n-heptane mechanism is employed to investigate spontaneous ignition timing and location. The results from simple chemistry showed that the previous findings from 2D DNS, that ignition occurred at the most reactive mixture fraction (MR) and at small values of the conditional scalar dissipation rate (N|MR), are valid also for 3D turbulent mixing fields. However, in the Negative Temperature Coefficient regime (NTC), the most reactive mixture fraction is very rich and ignition seems to occur at high values of scalar dissipation. This is not consistent with a previous conjecture that the first appearance of ignition is correlated with the low-N content of the conditional probability density function of N.
The treatment of reliable chemistry in complex flow codes are of great importance for the correct predictions of control parameters such as ignition time and flame temperatures. However, the inclusion of detailed chemistry in such complex flow codes is demanding in terms of both computational time and memory requirements. This is because the chemical reaction system is governed by a set of stiff differential equations determining the time evolution of each chemical species based on consumption and production through chemical reactions. Much effort is devoted to developing methods to eliminate the species governed by the shortest time. A method for reducing reaction mechanisms will be discussed which is based on a time-scale analysis much similar to typical model reduction techniques. This enables the set of variable that are transported in the flow codes to be significantly reduced. Also, a procedure to automatically optimize the sparsity of the Jacobian matrix governing the chemical evolution is implemented resulting in a significant computational speed-up.
Location: Stauffer Science Lecture Hall (SLH) Rm 102
Audiences: Everyone Is Invited
Contact: April Mundy
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Lyman L. Handy Colloquium
Thu, Dec 14, 2006 @ 12:45 PM
Mork Family Department of Chemical Engineering and Materials Science
Conferences, Lectures, & Seminars
Rheology and Fluid Mechanics of Polymer Solutions UndergoingRapid Elongational Deformations Professor Robert E. Armstrong
Department of Chemical Engineering
Massachusetts Institute of Technology
Location: Olin Hall of Engineering (OHE) - 122
Audiences: Everyone Is Invited
Contact: Petra Pearce
