La Cañada Flintridge, CA, United States
La Cañada Flintridge, CA, United States

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Mainzer A.,Jet Propulsion Laboratory | Bauer J.,Jet Propulsion Laboratory | Bauer J.,California Institute of Technology | Grav T.,Johns Hopkins University | And 32 more authors.
Astrophysical Journal | Year: 2011

The Wide-field Infrared Survey Explorer (WISE) has surveyed the entire sky at four infrared wavelengths with greatly improved sensitivity and spatial resolution compared to its predecessors, the Infrared Astronomical Satellite and the Cosmic Background Explorer. NASA's Planetary Science Division has funded an enhancement to the WISE data processing system called "NEOWISE" that allows detection and archiving of moving objects found in the WISE data. NEOWISE has mined the WISE images for a wide array of small bodies in our solar system, including near-Earth objects (NEOs), Main Belt asteroids, comets, Trojans, and Centaurs. By the end of survey operations in 2011 February, NEOWISE identified over 157,000 asteroids, including more than 500 NEOs and ∼120 comets. The NEOWISE data set will enable a panoply of new scientific investigations. © 2011. The American Astronomical Society. All rights reserved.


PubMed | University of Southern California, Flintridge Preparatory School, University of California at Los Angeles and Lamar University
Type: | Journal: Journal of molecular graphics & modelling | Year: 2016

Recently, we presented a computational framework named VizBET to simulate and visualize biological electron-transfer (ET) dynamics. The visualization process was encapsulated as a plugin to the Visual Molecular Dynamics (VMD) software. However, the users ability to understand complex, multidimensional ET pathways was severely limited when visualized in 2D on traditional computer monitors. To provide a more accurate representation with enhanced depth perception, we here present an extension of VizBET named iBET to render the VMD model of ET dynamics in a commodity virtual reality (VR) platform. The paper describes detailed procedures to export VMD models into the Unity game engine and render it in an Oculus Rift head mounted display. With the increasing availability of low-cost VR systems like the Rift and rich programmability of game engines, the iBET framework provides a powerful means to explore and understand not only biological ET processes but also a unique experiential tool for broad scientific communities.


Shin H.K.,Inha University | Park M.,Chonbuk National University | Kim H.-Y.,Chonbuk National University | Jin F.-L.,Jilin Institute of Chemical Technology | And 4 more authors.
Bulletin of the Korean Chemical Society | Year: 2013

Chitosan non-woven fabrics were acetylated to improve their antimicrobial properties. The active chlorine content, antimicrobial properties, storage stability, and surface properties of acetylated chitosan non-woven fabrics were investigated. The active chlorine content of the fabrics increased upon reduction of the degree of the acetylation or increase in sodium hypochlorite concentration. Acetylated chitosan non-woven fabrics showed powerful antimicrobial activity by efficiently killing Escherichia coli and forming a growth inhibition zone for Staphylococcus aureus. Furthermore, scanning electron microscopy observations demonstrated that the acetylated chitosan non-woven fabrics were not damaged in sodium hypochlorite solution.


Line M.R.,California Institute of Technology | Wolf A.S.,California Institute of Technology | Zhang X.,California Institute of Technology | Knutson H.,California Institute of Technology | And 5 more authors.
Astrophysical Journal | Year: 2013

Exoplanet atmosphere spectroscopy enables us to improve our understanding of exoplanets just as remote sensing in our own solar system has increased our understanding of the solar system bodies. The challenge is to quantitatively determine the range of temperatures and molecular abundances allowed by the data, which is often difficult given the low information content of most exoplanet spectra that commonly leads to degeneracies in the interpretation. A variety of spectral retrieval approaches have been applied to exoplanet spectra, but no previous investigations have sought to compare these approaches. We compare three different retrieval methods: optimal estimation, differential evolution Markov chain Monte Carlo, and bootstrap Monte Carlo on a synthetic water-dominated hot Jupiter. We discuss expectations of uncertainties in abundances and temperatures given current and potential future observations. In general, we find that the three approaches agree for high spectral resolution, high signal-to-noise data expected to come from potential future spaceborne missions, but disagree for low-resolution, low signal-to-noise spectra representative of current observations. We also compare the results from a parameterized temperature profile versus a full classical Level-by-Level approach and discriminate in which situations each of these approaches is applicable. Furthermore, we discuss the implications of our models for the inferred C-to-O ratios of exoplanetary atmospheres. Specifically, we show that in the observational limit of a few photometric points, the retrieved C/O is biased toward values near solar and near one simply due to the assumption of uninformative priors. © 2013. The American Astronomical Society. All rights reserved.


Machado A.C.D.,University of Southern California | Saleebyan S.B.,La Canada High School | Holmes B.T.,La Canada High School | Karelina M.,La Canada High School | And 8 more authors.
Biochemistry and Molecular Biology Education | Year: 2012

3D visualization assists in identifying diverse mechanisms of protein-DNA recognition that can be observed for transcription factors and other DNA binding proteins. We used Proteopedia to illustrate transcription factor-DNA readout modes with a focus on DNA shape, which can be a function of either nucleotide sequence (Hox proteins) or base pairing geometry (p53). © 2012 Wiley Periodicals, Inc.


Nakano C.M.,Flintridge Preparatory School | Byun H.S.,University of Southern California | Ma H.,Lamar University | Wei T.,Lamar University | And 2 more authors.
Computer Physics Communications | Year: 2015

Electron transfer (ET) dictates a wide variety of energy-conversion processes in biological systems. Visualizing ET dynamics could provide key insight into understanding and possibly controlling these processes. We present a computational framework named VizBET to visualize biological ET dynamics, using an outer-membrane Mtr-Omc cytochrome complex in Shewanella oneidensis MR-1 as an example. Starting from X-ray crystal structures of the constituent cytochromes, molecular dynamics simulations are combined with homology modeling, protein docking, and binding free energy computations to sample the configuration of the complex as well as the change of the free energy associated with ET. This information, along with quantum-mechanical calculations of the electronic coupling, provides inputs to kinetic Monte Carlo (KMC) simulations of ET dynamics in a network of heme groups within the complex. Visualization of the KMC simulation results has been implemented as a plugin to the Visual Molecular Dynamics (VMD) software. VizBET has been used to reveal the nature of ET dynamics associated with novel nonequilibrium phase transitions in a candidate configuration of the Mtr-Omc complex due to electron-electron interactions. © 2015 Elsevier B.V. All rights reserved.


Liu V.,Flintridge Preparatory School | Patel M.,University of California at Irvine | Lee A.,University of California at Irvine
17th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2013 | Year: 2013

A microfluidic device was developed based on the principle of particle retention using microfilter structures with different pore sizes (10∼30μm) and a micro-well structure to automatically separate Red Blood cells (RBCs), White Blood cells (WBCs), and plasma into different compartments so that blood morphology study can be performed easily. The device only allowed pure plasma to come out for further immunoassay analysis. Experiments showed that the device successfully fractionated blood components and the obtained images of various abnormal blood cells including sickle cells and immature granulocytes are indication of a patient's health status. The device presents a more practical way of blood cell analysis compared to conventional blood smears.


Masato Nakano C.,Flintridge Preparatory School | Sajib M.S.J.,Lamar University | Samieegohar M.,Lamar University | Wei T.,Lamar University
Applied Physics Letters | Year: 2016

Trilayer graphene (TLG) is attracting a lot of attention as their stacking structures (i.e., rhombohedral vs. Bernal) drastically affect electronic and optical properties. Based on full-atom molecular dynamics simulations, we here predict electric field-induced rhombohedral-to-Bernal transition of TLG tethered with proteins. Furthermore, our simulations show that protein's electrophoretic mobility and diffusivity are enhanced on TLG surface. This phenomenon of controllable TLG stacking transition will contribute to various applications including biosensing. © 2016 AIP Publishing LLC.


Nakano C.M.,Flintridge Preparatory School | Ma H.,Lamar University | Wei T.,Lamar University
Applied Physics Letters | Year: 2015

Understanding protein adsorption is a key to the development of biosensors and anti-biofouling materials. Hydration essentially controls the adsorption process on hydrophobic surfaces, but its effect is complicated by various factors. Here, we present an ideal model system to isolate hydration effects - lysozyme adsorption on a flat hydrophobic graphene surface. Our all-atom molecular dynamics and molecular-mechanics/Poisson-Boltzmann surface area computation study reveal that lysozyme on graphene displays much larger diffusivity than in bulk water. Protein's hydration free energy within the first hydration shell is dominated by the protein-water electrostatic interactions and acts as an energy barrier for protein adsorption. On the other hand, the surface tension, especially that from the hydrophobic graphene, can effectively weaken the barrier to promote adsorption. © 2015 AIP Publishing LLC.


Liu V.,Flintridge Preparatory School | Simon M.,University of California at Irvine | Patel M.,University of California at Irvine | Lee A.,University of California at Irvine
18th International Conference on Miniaturized Systems for Chemistry and Life Sciences, MicroTAS 2014 | Year: 2014

A fully integrated microfluidic device was developed to automatically separate human blood cells and perform cell morphology studies on a chip. The device was designed based on acoustic microstreaming and hydrodynamic principles to separate Red Blood Cells (RBCs) from White Blood Cells (WBCs). Besides serving as a micropump, Acoustic microstreaming enabled highly efficient blood cell separation (89% rate) similar to that of conventional centrifugation. The device fractionated blood components and images of various blood cells including sickle cells and immature granulocytes were obtained. The device presents a more practical method for blood cell analysis compared to conventional blood smears. © 14CBMS.

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