1,071 research outputs found
Myocarditis, disseminated infection, and early viral persistence following experimental coxsackievirus B infection of cynomolgus monkeys.
Coxsackievirus B (CVB) infection is a common cause of acute viral myocarditis. The clinical presentation of myocarditis caused by this enterovirus is highly variable, ranging from mildly symptoms to complete hemodynamic collapse. These variations in initial symptoms and in the immediate and long term outcomes of this disease have impeded development of effective treatment strategies. Nine cynomolgus monkeys were inoculated with myocarditic strains of CVB. Virological studies performed up to 28 days post-inoculation demonstrated the development of neutralizing antibody in all animals, and the presence of CVB in plasma. High dose intravenous inoculation (n = 2) resulted in severe disseminated disease, while low dose intravenous (n = 6) or oral infection (1 animal) resulted in clinically unapparent infection. Transient, minor, echocardiographic abnormalities were noted in several animals, but no animals displayed signs of significant acute cardiac failure. Although viremia rapidly resolved, signs of myocardial inflammation and injury were observed in all animals at the time of necropsy, and CVB was detected in postmortem myocardial specimens up to 28 days PI. This non-human primate system replicates many features of illness in acute coxsackievirus myocarditis and demonstrates that myocardial involvement may be common in enteroviral infection; it may provide a model system for testing of treatment strategies for enteroviral infections and acute coxsackievirus myocarditis
The lesson of causal discovery algorithms for quantum correlations: Causal explanations of Bell-inequality violations require fine-tuning
An active area of research in the fields of machine learning and statistics
is the development of causal discovery algorithms, the purpose of which is to
infer the causal relations that hold among a set of variables from the
correlations that these exhibit. We apply some of these algorithms to the
correlations that arise for entangled quantum systems. We show that they cannot
distinguish correlations that satisfy Bell inequalities from correlations that
violate Bell inequalities, and consequently that they cannot do justice to the
challenges of explaining certain quantum correlations causally. Nonetheless, by
adapting the conceptual tools of causal inference, we can show that any attempt
to provide a causal explanation of nonsignalling correlations that violate a
Bell inequality must contradict a core principle of these algorithms, namely,
that an observed statistical independence between variables should not be
explained by fine-tuning of the causal parameters. In particular, we
demonstrate the need for such fine-tuning for most of the causal mechanisms
that have been proposed to underlie Bell correlations, including superluminal
causal influences, superdeterminism (that is, a denial of freedom of choice of
settings), and retrocausal influences which do not introduce causal cycles.Comment: 29 pages, 28 figs. New in v2: a section presenting in detail our
characterization of Bell's theorem as a contradiction arising from (i) the
framework of causal models, (ii) the principle of no fine-tuning, and (iii)
certain operational features of quantum theory; a section explaining why a
denial of hidden variables affords even fewer opportunities for causal
explanations of quantum correlation
Analysis of the interaction of Spray G and in-cylinder flow in two optical engines for late gasoline direct injection
This is the author's version of a work that was accepted for publication in International Journal of Engine Research. Changes resulting from the publishing process, such as peer review, editing, corrections, structural formatting,
and other quality control mechanisms may not be reflected in this document. Changes may have been made to this work since it was submitted for publication. A definitive version was subsequently published as https://doi.org/10.1177/1468087419881535.[EN] An investigation of the interaction between the in-cylinder flow and the spray topology in two spray-guided direct injection optical engines is reported. The bulk flow field in the combustion chamber is characterized using particle image velocimetry. Geometrical parameters such as the axial penetration and the spray angle of the liquid spray are measured using Mie scatter imaging and/or diffuse back-illumination. The measured parameters are compared with data from a constant volume chamber available in the literature. For a late injection strategy, the so-called ECN Spray G standard condition, the mean values of the spray penetration do not seem to be significantly perturbed by the in-cylinder flow motion until the plumes approach the piston surface. However, spray probability maps reveal that cycle-to-cycle fluctuations of the spatial distribution of the liquid spray are affected by the magnitude of the in-cylinder flow. Particle image velocimetry during injection shows that the flow field in the vicinity of the spray plumes is heavily influenced by air entrainment, and that an upward flow in-between spray plumes develops. Consistent with previous research that demonstrated the importance of the latter flow structure for the prevention of spray collapse, it is found that increased in-cylinder flow magnitudes due to increased intake valve lifts or engine speeds enhance the spray-shape stability. Compared with cases without injection, the influence of the spray on the in-cylinder flow field is still noticeable approximately 2.5 ms after the start of injection.The author(s) disclosed receipt of the following financial support for the research, authorship, and/or publication of this article: The work at UDE was funded by the Research Association for Combustion Engines eV (FVV, Frankfurt/Main, project 1203). TUD kindly acknowledges generous support by Deutsche Forschungsgemeinschaft through SFB/Transregio 150 (project number 237267381-TRR150).Geschwindner, C.; Kranz, P.; Welch, C.; Schmidt, M.; Bohm, B.; Kaiser, SA.; De La Morena, J. (2020). Analysis of the interaction of Spray G and in-cylinder flow in two optical engines for late gasoline direct injection. International Journal of Engine Research. 21(1):169-184. https://doi.org/10.1177/1468087419881535S169184211Alkidas, A. C. (2007). Combustion advancements in gasoline engines. Energy Conversion and Management, 48(11), 2751-2761. doi:10.1016/j.enconman.2007.07.027Costa, M., Marchitto, L., Merola, S. S., & Sorge, U. (2014). Study of mixture formation and early flame development in a research GDI (gasoline direct injection) engine through numerical simulation and UV-digital imaging. Energy, 77, 88-96. doi:10.1016/j.energy.2014.04.114Zhao, F., Lai, M.-C., & Harrington, D. . (1999). Automotive spark-ignited direct-injection gasoline engines. Progress in Energy and Combustion Science, 25(5), 437-562. doi:10.1016/s0360-1285(99)00004-0Moreira, A. L. N., Moita, A. S., & Panão, M. R. (2010). Advances and challenges in explaining fuel spray impingement: How much of single droplet impact research is useful? Progress in Energy and Combustion Science, 36(5), 554-580. doi:10.1016/j.pecs.2010.01.002Oh, H., & Bae, C. (2013). Effects of the injection timing on spray and combustion characteristics in a spray-guided DISI engine under lean-stratified operation. Fuel, 107, 225-235. doi:10.1016/j.fuel.2013.01.019Park, C., Kim, S., Kim, H., & Moriyoshi, Y. (2012). Stratified lean combustion characteristics of a spray-guided combustion system in a gasoline direct injection engine. Energy, 41(1), 401-407. doi:10.1016/j.energy.2012.02.060Stiehl, R., Schorr, J., Krüger, C., Dreizler, A., & Böhm, B. (2013). In-Cylinder Flow and Fuel Spray Interactions in a Stratified Spray-Guided Gasoline Engine Investigated by High-Speed Laser Imaging Techniques. Flow, Turbulence and Combustion, 91(3), 431-450. doi:10.1007/s10494-013-9500-xPiock, W. F., Befrui, B., Berndorfer, A., & Hoffmann, G. (2015). Fuel Pressure and Charge Motion Effects on GDi Engine Particulate Emissions. SAE International Journal of Engines, 8(2), 464-473. doi:10.4271/2015-01-0746Fansler, T. D., Reuss, D. L., Sick, V., & Dahms, R. N. (2015). Invited Review: Combustion instability in spray-guided stratified-charge engines: A review. International Journal of Engine Research, 16(3), 260-305. doi:10.1177/1468087414565675Drake, M. C., & Haworth, D. C. (2007). Advanced gasoline engine development using optical diagnostics and numerical modeling. Proceedings of the Combustion Institute, 31(1), 99-124. doi:10.1016/j.proci.2006.08.120Fansler, T. D., Stojkovic, B., Drake, M. C., & Rosalik, M. E. (2002). Local fuel concentration measurements in internal combustion engines using spark-emission spectroscopy. Applied Physics B: Lasers and Optics, 75(4-5), 577-590. doi:10.1007/s00340-002-0954-0Peterson, B., Reuss, D. L., & Sick, V. (2014). On the ignition and flame development in a spray-guided direct-injection spark-ignition engine. Combustion and Flame, 161(1), 240-255. doi:10.1016/j.combustflame.2013.08.019Schiffmann, P., Reuss, D. L., & Sick, V. (2017). Empirical investigation of spark-ignited flame-initiation cycle-to-cycle variability in a homogeneous charge reciprocating engine. International Journal of Engine Research, 19(5), 491-508. doi:10.1177/1468087417720558Sementa, P., Maria Vaglieco, B., & Catapano, F. (2012). Thermodynamic and optical characterizations of a high performance GDI engine operating in homogeneous and stratified charge mixture conditions fueled with gasoline and bio-ethanol. Fuel, 96, 204-219. doi:10.1016/j.fuel.2011.12.068Song, J., & Park, S. (2015). EFFECT OF INJECTION STRATEGY ON THE SPRAY DEVELOPMENT PROCESS IN A SINGLE-CYLINDER OPTICAL GDI ENGINE. Atomization and Sprays, 25(9), 819-836. doi:10.1615/atomizspr.2015012018Parrish, S. E., Zhang, G., & Zink, R. J. (2012). Liquid and Vapor Envelopes of Sprays from a Multi-Hole Fuel Injector Operating under Closely-Spaced Double-Injection Conditions. SAE International Journal of Engines, 5(2), 400-414. doi:10.4271/2012-01-0462Rachakonda, S. K., Paydarfar, A., & Schmidt, D. P. (2018). Prediction of spray collapse in multi-hole gasoline direct-injection fuel injectors. International Journal of Engine Research, 20(1), 18-33. doi:10.1177/1468087418819527Blessinger, M., Manin, J., Skeen, S. A., Meijer, M., Parrish, S., & Pickett, L. M. (2014). Quantitative mixing measurements and stochastic variability of a vaporizing gasoline direct-injection spray. International Journal of Engine Research, 16(2), 238-252. doi:10.1177/1468087414531971Sphicas, P., Pickett, L. M., Skeen, S. A., & Frank, J. H. (2017). Inter-plume aerodynamics for gasoline spray collapse. International Journal of Engine Research, 19(10), 1048-1067. doi:10.1177/1468087417740306Lacey, J., Poursadegh, F., Brear, M. J., Gordon, R., Petersen, P., Lakey, C., … Ryan, S. (2017). Generalizing the behavior of flash-boiling, plume interaction and spray collapse for multi-hole, direct injection. Fuel, 200, 345-356. doi:10.1016/j.fuel.2017.03.057Westlye, F. R., Penney, K., Ivarsson, A., Pickett, L. M., Manin, J., & Skeen, S. A. (2017). Diffuse back-illumination setup for high temporally resolved extinction imaging. Applied Optics, 56(17), 5028. doi:10.1364/ao.56.005028Payri, R., Salvador, F. J., Martí-Aldaraví, P., & Vaquerizo, D. (2017). ECN Spray G external spray visualization and spray collapse description through penetration and morphology analysis. Applied Thermal Engineering, 112, 304-316. doi:10.1016/j.applthermaleng.2016.10.023Kranz, P., & Kaiser, S. A. (2019). LIF-based imaging of preferential evaporation of a multi-component gasoline surrogate in a direct-injection engine. Proceedings of the Combustion Institute, 37(2), 1365-1372. doi:10.1016/j.proci.2018.06.214Baum, E., Peterson, B., Böhm, B., & Dreizler, A. (2013). On The Validation of LES Applied to Internal Combustion Engine Flows: Part 1: Comprehensive Experimental Database. Flow, Turbulence and Combustion, 92(1-2), 269-297. doi:10.1007/s10494-013-9468-6Menser, J., Schneider, F., Dreier, T., & Kaiser, S. A. (2018). Multi-pulse shadowgraphic RGB illumination and detection for flow tracking. Experiments in Fluids, 59(6). doi:10.1007/s00348-018-2541-
Linear and nonlinear traveling edge waves in optical honeycomb lattices
Traveling unidirectional localized edge states in optical honeycomb lattices are analytically constructed. They are found in honeycomb arrays of helical waveguides designed to induce a periodic pseudomagnetic field varying in the direction of propagation. Conditions on whether a given pseudofield supports a traveling edge mode are discussed; a special case of the pseudofields studied agrees with recent experiments. Interesting classes of dispersion relations are obtained. Envelopes of nonlinear edge modes are described by the classical one-dimensional nonlinear Schrödinger equation along the edge. Nonlinear states termed edge solitons are predicted analytically and are found numerically
Vigilin interacts with signal peptide peptidase.
BACKGROUND: Signal peptide peptidase (SPP), a member of the presenilin-like intra-membrane cleaving aspartyl protease family, migrates on Blue Native (BN) gels as 100 kDa, 200 kDa and 450 kDa species. SPP has recently been implicated in other non-proteolytic functions such as retro-translocation of MHC Class I molecules and binding of misfolded proteins in the endoplasmic reticulum (ER). These high molecular weight SPP complexes might contain additional proteins that regulate the proteolytic activity of SPP or support its non-catalytic functions. RESULTS: In this study, an unbiased iTRAQ-labeling mass spectrometry approach was used to identify SPP-interacting proteins. We found that vigilin, a ubiquitous multi-KH domain containing cytoplasmic protein involved in RNA binding and protein translation control, selectively enriched with SPP. Vigilin interacted with SPP and both proteins co-localized in restricted intracellular domains near the ER, biochemically co-fractionated and were part of the same 450 kDa complex on BN gels. However, vigilin does not alter the protease activity of SPP, suggesting that the SPP-vigilin interaction might be involved in the non-proteolytic functions of SPP. CONCLUSIONS: We have identified and validated vigilin as a novel interacting partner of SPP that could play an important role in the non-proteolytic functions of SPP. This data adds further weight to the idea that intramembrane-cleaving aspartyl proteases, such as presenilin and SPPs, could have other functions besides the proteolysis of short membrane stubs.RIGHTS : This article is licensed under the BioMed Central licence at http://www.biomedcentral.com/about/license which is similar to the 'Creative Commons Attribution Licence'. In brief you may : copy, distribute, and display the work; make derivative works; or make commercial use of the work - under the following conditions: the original author must be given credit; for any reuse or distribution, it must be made clear to others what the license terms of this work are
Structural basis for the antiarrhythmic blockade of a potassium channel with a small molecule
Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/154620/1/fsb2fj201700349r.pd
Quasi-probability representations of quantum theory with applications to quantum information science
This article comprises a review of both the quasi-probability representations
of infinite-dimensional quantum theory (including the Wigner function) and the
more recently defined quasi-probability representations of finite-dimensional
quantum theory. We focus on both the characteristics and applications of these
representations with an emphasis toward quantum information theory. We discuss
the recently proposed unification of the set of possible quasi-probability
representations via frame theory and then discuss the practical relevance of
negativity in such representations as a criteria for quantumness.Comment: v3: typos fixed, references adde
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