3,561 research outputs found

    Stains Induce Apoptosis and Autophagy in Primary and Transformed Mast Cells

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    Statin drugs are widely employed in the clinic to reduce serum low density lipoproteins (LDLs) in patients with hypocholesteremia. In addition to their cholesterol-lowering effects through HMG CoA reductase antagonism, isoprenyl lipids necessary for membrane anchorage and signaling of small G-proteins are abrogated. We previously found that statins suppress mast cell activation in murine and human cells, suggesting these drugs might be useful in treating allergic disease. While mast cell function is critical to allergic inflammation, mast cell hyperplasia and survival also impact these diseases, and were not studied in our previous work. In this study, we describe Fluvastatin-mediated apoptosis in both primary and transformed mast cells. An IC50 was achieved between 1-5μM in both systems, and apoptosis was preceded by mitochondrial dysfunction and caspase release. In addition to apoptosis, our work also uncovered evidence of autophagy, which can serve as a compensatory mechanism during apoptosis. Interestingly, autophagy appeared to be cyto-protective in the primary cells yet cytotoxic in transformed mast cells. These findings offer insight into the mechanisms of mast cell survival and support the possible utility of statins in mast cell-associated allergic and neoplastic diseases

    Hierarchical Stochastic Block Model for Community Detection in Multiplex Networks

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    Multiplex networks have become increasingly more prevalent in many fields, and have emerged as a powerful tool for modeling the complexity of real networks. There is a critical need for developing inference models for multiplex networks that can take into account potential dependencies across different layers, particularly when the aim is community detection. We add to a limited literature by proposing a novel and efficient Bayesian model for community detection in multiplex networks. A key feature of our approach is the ability to model varying communities at different network layers. In contrast, many existing models assume the same communities for all layers. Moreover, our model automatically picks up the necessary number of communities at each layer (as validated by real data examples). This is appealing, since deciding the number of communities is a challenging aspect of community detection, and especially so in the multiplex setting, if one allows the communities to change across layers. Borrowing ideas from hierarchical Bayesian modeling, we use a hierarchical Dirichlet prior to model community labels across layers, allowing dependency in their structure. Given the community labels, a stochastic block model (SBM) is assumed for each layer. We develop an efficient slice sampler for sampling the posterior distribution of the community labels as well as the link probabilities between communities. In doing so, we address some unique challenges posed by coupling the complex likelihood of SBM with the hierarchical nature of the prior on the labels. An extensive empirical validation is performed on simulated and real data, demonstrating the superior performance of the model over single-layer alternatives, as well as the ability to uncover interesting structures in real networks

    Electrochemical Characterization of Nonaqueous Systems for Secondary Battery Application Quarterly Report, May - Jul. 1968

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    Electrochemical characterization of nonaqueous systems for secondary battery applicatio

    Electrochemical characterization of nonaqueous systems for secondary battery application Quarterly report, Aug. - Oct. 1967

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    Multisweep cyclic voltammograms for electrochemical characterization of nonaqueous systems for secondary battery application

    Comparison of Thematic Maps Using Symbolic Entropy

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    Comparison of thematic maps is an important task in a number of disciplines. Map comparison has traditionally been conducted using cell-by-cell agreement indicators, such as the Kappa measure. More recently, other methods have been proposed that take into account not only spatially coincident cells in two maps, but also their surroundings or the spatial structure of their differences. The objective of this paper is to propose a framework for map comparison that considers 1) the patterns of spatial association in two maps, in other words, the map elements in their surroundings; 2) the equivalence of those patterns; and 3) the independence of patterns between maps. Two new statistics for the spatial analysis of qualitative data are introduced. These statistics are based on the symbolic entropy of the maps, and function as measures of map compositional equivalence and independence. As well, all inferential elements to conduct hypothesis testing are developed. The framework is illustrated using real and synthetic maps. Key word: Thematic maps, map comparison, qualitative variables, spatial association, symbolic entropy, hypothesis tests

    Electrochemical characterization of nonaqueous systems for secondary battery application Quarterly report, Feb. - Apr. 1968

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    Electrochemical characterization of nonaqueous battery systems to determine solubility and reactivity effects on electrode compatibilit

    Manifold spirals, disc-halo interactions and the secular evolution in N-body models of barred galaxies

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    The manifold theory of barred-spiral structure provides a dynamical mechanism explaining how spiral arms beyond the ends of galactic bars can be supported by chaotic flows extending beyond the bar's co-rotation zone. We discuss its applicability to N-body simulations of secularly evolving barred galaxies. In these simulations, we observe consecutive `incidents' of spiral activity, leading to a time-varying disc morphology. Besides disc self-excitations, we provide evidence of a newly noted excitation mechanism related to the `off-centering' effect: particles ejected in elongated orbits at major incidents cause the disc center-of-mass to recoil and be set in a wobble-type orbit with respect to the halo center of mass. The time-dependent m=1 perturbation on the disc by the above mechanism correlates with the excitation of new incidents of non-axisymmetric activity beyond the bar. At every new excitation, the manifolds act as dynamical avenues attracting particles which are directed far from corotation along chaotic orbits. The fact that the manifolds evolve morphologically in time, due to varying non-axisymmetric perturbations, allows to reconcile manifolds with the presence of multiple patterns and frequencies in the disc. We find a time-oscillating pattern speed profile Ωp(R)\Omega_p(R) at distances R between the bar's corotation, at resonance with the succession of minima and maxima of the non-axisymmetric activity beyond the bar. Finally, we discuss disc thermalization, i.e., the evolution of the disc velocity dispersion profile and its connection with disc responsiveness to manifold spirals.Comment: 20 pages, 22 figures. Accepted for publication in MNRA

    Electrochemical characterization of nonaqueous systems for secondary battery application Quarterly report, Nov. 1967 - Jan. 1968

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    Multisweep cyclic voltammograms for electrochemical characterization of nonaqueous systems for secondary battery application

    Electrochemical characterization of nonaqueous systems for secondary battery application

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    Electrochemical evaluation of electrode organic electrolyte combinations for rechargeable battery system
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