Szmodis A.W.,University of California at Davis |
Blanchette C.D.,University of California at Davis |
Longo M.L.,University of California at Davis |
Orme C.A.,Lawrence Livermore National Laboratory |
Parikh A.N.,University of the Californias
Biointerphases | Year: 2010
The authors have studied microstructure evolution during thermally induced phase separation in a class of binary supported lipid bilayers using a quantitative application of imaging ellipsometry. The bilayers consist of binary mixtures consisting of a higher melting glycosphingolipid, galactosylceramide (GalCer), which resides primarily in the outer leaflet, and a lower melting, unsaturated phospholipid, 1,2-dilauroyl-sn-glycero-3-phosphocholine (DLPC). Three different bilayer compositions of GalCer/DLPC mixtures at 35:65, 20:80, and 10:90 molar ratios were cooled at controlled rates from their high-temperature homogeneous phase to temperatures corresponding to their phase coexistence regime and imaged in real time using imaging ellipsometry. During the thermotropic course of GalCer gelation, we find that two distinct types of morphological features modulate. First, the formation and growth of chain and fractal-like defects ascribed to the net change in molecular areas during the phase transition. The formation of these defects is consistent with the expected contraction in the molecular area during the liquid crystalline to gel-phase transition. Second, the nucleation and growth of irregularly shaped gel-phase domains, which exhibit either line-tension dominated compact shape or dendritic domains with extended interfaces. Quantifying domain morphology within the fractal framework reveals a close correspondence, and the quantization of the transition width confirms previous estimates of reduced phase transition cooperativity in supported bilayers. A comparison of domain properties indicates that thermal history, bilayer composition, and cooling rate all influence microstructure details including shapes, sizes, and distributions of domains and defects: At lower cooling rates and lower GalCer fractions compact domains form and at higher GalCer fractions (or at higher cooling rates) dendritic domains are evident. This transition of domain morphology from compact shapes to dendritic shapes at higher cooling rates and higher relative fractions of GalCer suggests kinetic control of shape equilibration in these phospho- and glycolipid mixtures. © 2010 American Vacuum Society.
Bostic R.W.,University of the Californias |
Rudd E.C.,Office of Policy Development and Research |
Sternthal M.J.,Deputy director of federal affairs
Health Affairs | Year: 2012
The link between federal housing policy and public health has been understood since the nineteenth century, when housing activists first sought to abolish slums and create healthful environments. This article describes how the Obama administration-building on these efforts and those that followed, including the Great Society programs of President Lyndon Johnson-has adopted a cross-sector approach that takes health considerations into account when formulating housing and community development policy. The federal Department of Housing and Urban Development fully embraces this "health in all policies" approach. Nonetheless, the administration's strategy faces challenges, including fiscal and political ones. Some of these challenges may be overcome by conducting quality research on how housing and community development policies affect health outcomes, and by developing a federal budget strategy that takes into account how investments in one sector contribute to cost savings in another. ©2012 Project HOPE- The People-to-People Health Foundation, Inc.
Zhang D.,Lamar University |
Chung R.,University of the Californias |
Karki A.B.,Louisiana State University |
Li F.,Rice University |
And 2 more authors.
Journal of Physical Chemistry C | Year: 2010
Iron nanoparticle reinforced polyacrylonitrile (PAN) nanocomposites are fabricated by a facile and environmentally benign solvent extraction method. Fourier transform infrared (FT-IR), thermal gravimetric analysis (TGA), and differential scanning calorimetry (DSC) results indicate a strong interaction between the iron nanoparticles and the polymer matrix for the as-prepared polymer nanocomposites. The heat treatment induces the carbonization of the polymer matrix. High-resolution transmission electron microscopy (HRTEM) and X-ray diffraction (XRD) analysis show a protecting carbon shell surrounding the iron nanoparticles within the carbon matrix against the particle oxidation. The magnetic properties, electrical conductivity, and magnetic field dependent resistivity of heat-treated nanocomposites with different particle loadings are carried out in a physical properties measurement system by Quantum Design and by a standard four probe method. The saturation magnetization increases and the coercivity decreases with an increase of the nanoparticle loading. The heat-treated nanocomposites possess a room temperature magnetoresistance (MR) of 5.1% at a field of 90 kOe. The nanoparticle loading has a significant effect on the resistivity of nanocomposites. The heattreated nanocomposites show a particle loading dependent transport mechanism. A transition from semiconductive to metallic conduction was observed with an increase of the nanoparticle loading. © 2010 American Chemical Society.
Pham H.V.,University of California at Los Angeles |
Martin D.B.C.,University of the Californias |
Vanderwal C.D.,University of the Californias |
Houk K.N.,University of California at Los Angeles
Chemical Science | Year: 2012
Computational studies show that the base-mediated intramolecular Diels-Alder of tryptamine-derived Zincke aldehydes, used as a key step in the synthesis of the Strychnos alkaloids norfluorocurarine and strychnine, proceeds via a stepwise pathway. The experimentally determined importance of a potassium counterion in the base is explained by its ability to preorganize the Zincke aldehyde diene in an s-cis conformation suitable to bicyclization. Computation also supports the thermodynamic importance of the generation of a stable enolate in the final reaction step. The thermal cycloreversion reaction of the Diels-Alder products is also found to proceed in a stepwise manner. © 2012 The Royal Society of Chemistry.
Kreiss D.,University of North Carolina at Chapel Hill |
Ananny M.,University of the Californias
First Monday | Year: 2013
There is general consensus that the press is undergoing a fundamental shift in how it functions as a profession, a business, and a social institution due, in part, to the proliferation and practices of online networked media. But there is still little understanding of exactly how this shift can and should relate to journalism's role as a public-facing profession that produces and vets information using logics other than those offered by markets. We explore one aspect of this issue here by developing an argument for how and why the state might support online, networked journalism, arguing that the press is a unique guardian of the public interest and presenting ways in which it might help to create a robust online public sphere.
Woolf B.P.,University of Massachusetts Amherst |
Lane H.C.,University of the Californias |
Chaudhri V.K.,SRI International |
Kolodner J.L.,Georgia Institute of Technology
AI Magazine | Year: 2013
This article focuses on contributions that AI can make to address longterm educational goals. Challenges are described that support: (1) mentors for every learner; (2) learning 21st century skills; (3) interaction data for learning; (4) universal access to global classrooms; and (5) lifelong and lifewide learning. A vision and brief research agenda are described for each challenge along with goals that lead to development of global educational resources and the reuse and sharing of digital educational resources. Instructional systems with AI technology are described that currently support richer experiences for learners and supply researchers with new opportunities to analyze vast data sets of instructional behavior from big databases that record elements of learning, affect, motivation, and social interaction. Personalized learning is described that facilitates student and group experience, reflection, and assessment. Copyright © 2013, Association for the Advancement of Artificial Intelligence. All rights reserved.
Kazemzadeh A.,University of the Californias
2010 IEEE World Congress on Computational Intelligence, WCCI 2010 | Year: 2010
In this paper we describe a methodology that uses interval type-2 fuzzy logic to translate words that refer to emotions from Spanish to English. We build on previous research that aimed to map between emotional labels used in different natural language corpora. In this paper we extend our previous work by showing how a similar method can be used to translate between languages. First, we show how this methodology relates to other fuzzy logic emotion research, then we describe it, and finally show it in use and discuss its results. © 2010 IEEE.
Boehm B.,University of the Californias |
Boehm B.,University of Southern California |
Boehm B.,US National Academy of Engineering
IEEE Software | Year: 2010
Software evaluation has evolved and taken several forms, providing rapid change handling and high assurance. The single-step-to-full-capability process exemplified by the traditional waterfall or sequential V-model is appropriate if the product's requirements are prespecifiable and have a low probability of significant change, and if there's no value or chance to deliver a partial product capability. The evolutionary sequential process develops an initial operational capability and upgrades it on the basis of operational experience. Development team stabilized for on-time, high-assurance delivery of the current increment and employing a concurrent verification and validation team to perform continuous defect detection to enable even higher-assurance levels.
Edgerly S.,Northwestern University |
Thorson K.,University of the Californias |
Bighash L.,University of the Californias |
Hannah M.,University of the Californias
Journal of Information Technology and Politics | Year: 2016
This paper explores political expression on Facebook during the 2012 presidential debates. We investigate how individuals and organizations appropriated media resources to craft responses to the debates, and what this reveals about sources of influence in political communication on social media. In particular, we compare the stream of posts that spread widely during the debates—content that “went viral”—with more mundane practices of personal expression to show differences between the viral content that caught the attention of news media coverage about the debates and the posting practices of individuals using their Facebook as a site for individual expression. © 2016 Taylor & Francis.
Rogers C.M.,University of the Californias |
Barnhart D.,University of the Californias |
Crago S.,University of Southern California
IEEE Aerospace Conference Proceedings | Year: 2016
The Maestro Flight Experiment (MFE) demonstrates the operation of a modern, many-core radiation hardened processor (the Maestro ITC) in space. The MFE executes diagnostics, performs image processing activities, addresses strategies for dealing with thermal and power constraints in orbit, and assesses the sensitivity of the processor to radiation exposure in low earth orbit. The MFE demonstrates a substantial advance in radiation hardened on-orbit computational performance, which is needed to handle the ever-increasing data load of modern imaging sensors and other orbital sensor systems. © 2016 IEEE.