Browsing by Subject "polarization"

Now showing 1 - 3 of 3
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    Does Ignorance Matter? The Relative Importance of Civic Knowledge and the Human Tendency to Engage in Motivated Reasoning
    (2015-03-02) Dusso, Aaron; Kennedy, Sheila Suess; Political Science, School of Liberal Arts
    It has long been understood that political knowledge in the U.S. is very low. For those who care about the quality of American democracy, this is a big problem. In attempting to find a solution, many people often blame education. While increasing civic knowledge is a laudatory goal, increased political sophistication does not necessarily turn individuals into good democratic citizens. Research in cognitive and social psychology paints a picture of people as motivated reasoners. Instead of having an open-minded engagement with issues, individuals typically only seek, see, and understand information in a manner that reinforces what they already believe. Here, we examine motivated reasoning and argue that the strongest partisans and the most committed ideologues will be the most susceptible to holding contradictory policy positions with regard to same-sex marriage and religious freedom.
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    Polarization Analysis Based on Realistic Lithium Ion Battery Electrode Microstructure Using Numerical Simulation
    (Office of the Vice Chancellor for Research, 2015-04-17) Yan, Bo; Lim, Cheolwoong; Song, Zhibin; Zhu, Likun
    The performance of lithium ion battery (LIB) is limited by the inner polarization and it is important to understand the factors that affect the polarization. This study focuses on the polarization analysis based on realistic 3D electrode microstructures. A c++ software was developed to rebuild and mesh the microstructure of cathode and anode electrodes through Nano-CT and Micro-CT scanned images respectively. As a result, the LIB model was composed of electrolyte, cathode and anode active materials and current collectors. By employing 3D finite volume method (FVM), another c++ code was developed to simulate the discharge and charge processes by solving coupled model equations. The simulation revealed the distribution of physical and electrochemical variables such as concentration, voltage, current density, reaction rate, et al. In order to explore the correlation of local effects and electrode structural heterogeneity, the cathode electrode were divided equally into 8 sub-divisions, of which the porosity, tortuosity, specific surface area were calculated. We computed the polarizations in the sub-divisions due to different sub-processes, i.e., the activation of electrochemical reactions and charge transport of species. As shown in Fig. 1, the tortuosity is very irregular because of unevenly distributed cathode particle size and packing pattern with low porosity. There are no exact and direct relations among porosity, tortuosity and specific surface area. Fig. 2 shows that the polarizations are related to the porosity in sub-divisions. The knowledge from the study will help to figure out the mechanism of polarization and power loss in LIB, which could be useful to improve LIB design and manufacturing. Acknowledgments: This work was supported by US National Science Foundation under Grant No. 1335850. Fig. 1 Porosity and tortuosity in sub-divisions of a cathode electrode Fig. 2 Intercalation reaction polarization and ionic conduction polarization of sub-divisions at 120 sec during a 5 C charging process
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    Polarization of Macrophages toward M2 Phenotype Is Favored by Reduction in iPLA2β (Group VIA Phospholipase A2)
    (American Society for Biochemistry and Molecular Biology, 2016-10-28) Ashley, Jason W.; Hancock, William D.; Nelson, Alexander J.; Bone, Robert N.; Tse, Hubert M.; Wohltmann, Mary; Turk, John; Ramanadham, Sasanka; Medicine, School of Medicine
    Macrophages are important in innate and adaptive immunity. Macrophage participation in inflammation or tissue repair is directed by various extracellular signals and mediated by multiple intracellular pathways. Activation of group VIA phospholipase A2 (iPLA2β) causes accumulation of arachidonic acid, lysophospholipids, and eicosanoids that can promote inflammation and pathologic states. We examined the role of iPLA2β in peritoneal macrophage immune function by comparing wild type (WT) and iPLA2β−/− mouse macrophages. Compared with WT, iPLA2β−/− macrophages exhibited reduced proinflammatory M1 markers when classically activated. In contrast, anti-inflammatory M2 markers were elevated under naïve conditions and induced to higher levels by alternative activation in iPLA2β−/− macrophages compared with WT. Induction of eicosanoid (12-lipoxygenase (12-LO) and cyclooxygenase 2 (COX2))- and reactive oxygen species (NADPH oxidase 4 (NOX4))-generating enzymes by classical activation pathways was also blunted in iPLA2β−/− macrophages compared with WT. The effects of inhibitors of iPLA2β, COX2, or 12-LO to reduce M1 polarization were greater than those to enhance M2 polarization. Certain lipids (lysophosphatidylcholine, lysophosphatidic acid, and prostaglandin E2) recapitulated M1 phenotype in iPLA2β−/− macrophages, but none tested promoted M2 phenotype. These findings suggest that (a) lipids generated by iPLA2β and subsequently oxidized by cyclooxygenase and 12-LO favor macrophage inflammatory M1 polarization, and (b) the absence of iPLA2β promotes macrophage M2 polarization. Reducing macrophage iPLA2β activity and thereby attenuating macrophage M1 polarization might cause a shift from an inflammatory to a recovery/repair milieu.