Modeling and Characterization of Electrical Transport in Oxygen Conducting Solid Electrolytes

A model for the electrical conductivity in acceptor-doped oxides which involves an association between the acceptor-dopants and oxygen vacancies resulting in donor centers is considered. The model relates the behavior of the electrical conductivity with the temperature, ambient atmosphere and band structure. The predictions of the model are compared to experimental data for ZrO₂:16% Y and SrCeO₃:5% Yb oxygen conductors and some band structure parameters have been determined.     

Positioning and Orientation in Indoor Environments Using Camera Phones

Location-based services, assistive technologies, ubiquitous computing, visual navigation, augmented reality, mobile applications     

In vivo neutrophil and lymphocyte function studies in a patient with leukocyte adhesion deficiency type II

We investigated in vivo neutrophil and lymphocyte function in a patient who lacks Sialyl-Lewis-X, a ligand for the selectin family of leukocyte adhesion molecules (leukocyte adhesion deficiency II, LAD II). As assessed by skin chamber and skin window techniques, in vivo chemotaxis of neutrophils was markedly impaired (less than 6% of normal values). A marginal pool was present as determined by an increase in circulating neutrophils after epinephrine injection and calculated recovery of infused radiolabeled autologous neutrophils. Kinetic studies showed a reduced half-life of 3.2 hours (normal 7 hours) and markedly increased turnover rate (cells/kg/d) of approximately eight times the normal value. A normal antibody response to the T-cell-dependent antigen bacteriophage phi X174 showed that T/B-cell interaction is not affected in LAD II. These findings provide direct evidence that the selectin family and its ligands play an important role in neutrophil function.     

Cytoplasmic domain of E-selectin contains a non-tyrosine endocytosis signal

E-selectin is an activation-dependent, endothelial cell-restricted adhesion molecule that is internalized and degraded rapidly once expressed on the cell surface. Tyrosine-containing structural motifs play an important role in the internalization of a number of integral proteins, and the membrane-proximal E-selectin cytoplasmic tyrosine residue (Tyr582) conforms to the endocytosis motif proposed previously. To determine the endocytosis motif in E-selectin, we selectively introduced truncation, substitution, and deletion mutations to the cytoplasmic tail of E-selectin. We analyzed the internalization kinetics of surface-expressed wild-type and mutant E-selectin constructs in transiently transfected Chinese hamster ovary cells using 125I-labeled E-selectin monoclonal antibody (125I-P6E2) in an acid elution assay. Interestingly, truncation immediately membrane proximal to Tyr582 (DeltaDGS construct) did not alter internalization kinetics significantly (DeltaDGS versus wild-type, mean surface half-life = 42 versus 45 min, respectively). Thus, it appears that the tyrosine residues are not required for internalization of E-selectin. Additional analyses indicated that Ser581 was necessary but alone was insufficient for surface E-selectin endocytosis. Thus, we conclude that there exists a novel non-tyrosine-containing endocytosis signal in the cytoplasmic tail which involves Ser581 and residues membrane-proximal to it.     

Improved insulin stability through amino acid substitution

Insulin analogs designed to decrease self-association and increaseabsorption rates from subcutaneous tissue were found to havealtered stability. Replacement of H^B10 with aspartic acid increasedstability while substitutions at B²⁸ and/or B²⁹ were eithercomparable to insulin or had decreased stability. The principalchemical degradation product of accelerated storage conditionswas a disulfidelinked multimer that was formed through a disulfideinterchange reaction which resulted from ß-eliminationof the disulfides. The maintenance of the native state of insulinwas shown to be important in protecting the disulfides fromreduction by dithiothreitol and implicitly from the disulfideinter change reaction that occurs during storage. To understandhow these amino acid changes alter chemical stability, the intramolecularconformational equilibria of each analog was assessed by equilibriumdenaturation. The Gibbs free energy of unfolding was comparedwith the chemical stability during storage for over 20 analogs.A significant positive correla tion (R²=0.8 and P < 0.0005)exists between the conformational stability and chemical stabilityof these analogs, indicating that the chemical stability ofinsulin's disulfides is under the thermodynamic control of theconformational equilibria.     

A space-filling visualization technique for multivariate small-world graphs

We introduce an information visualization technique, known as GreenCurve, for large multivariate sparse graphs that exhibit small-world properties. Our fractal-based design approach uses spatial cues to approximate the node connections and thus eliminates the links between the nodes in the visualization. The paper describes a robust algorithm to order the neighboring nodes of a large sparse graph by solving the Fiedler vector of its graph Laplacian, and then fold the graph nodes into a space-filling fractal curve based on the Fiedler vector. The result is a highly compact visualization that gives a succinct overview of the graph with guaranteed visibility of every graph node. GreenCurve is designed with the power grid infrastructure in mind. It is intended for use in conjunction with other visualization techniques to support electric power grid operations. The research and development of GreenCurve was conducted in collaboration with domain experts who understand the challenges and possibilities intrinsic to the power grid infrastructure. The paper reports a case study on applying GreenCurve to a power grid problem and presents a usability study to evaluate the design claims that we set forth.     

DNA computing capabilities for game theory

Problems in game theory can be used for benchmark DNA computations. Large numbers of game strategies and chance events can be assembledinto finite state machines. These many machines perform, in parallel,distinct plays of a game. Strategies can be exposed to selection and breeding.The computational capabilities of DNA are matched with aspects of game theory, but the most interesting problems are yet to be treated.     

A Novel Visualization Technique for Electric Power Grid Analytics

The application of information visualization holds tremendous promise for the electric power industry, but its potential has so far not been sufficiently exploited by the visualization community. Prior work on visualizing electric power systems has been limited to depicting raw or processed infor¬mation on top of a geographic layout. Little effort has been devoted to visualizing the physics of the power grids, which ultimately determines the condition and stability of the electricity infrastructure. Based on this assessment, we developed a novel visualization system prototype, GreenGrid, to explore the planning and monitoring of the North American Electricity Infrastructure. The paper discusses the rationale underlying the GreenGrid design, describes its implementation and performance details, and assesses its strengths and weaknesses against the current geographic-based power grid visualization. We also present a case study using GreenGrid to analyze the information collected moments before the last major electric blackout in the Western United States and Canada, and a usability study to evaluate the practical significance of our design in simulated real-life situations. Our result indicates that many of the disturbance characteristics can be readily identified with the proper form of visualization.