Thinking about Empire: The Administration of Ulysses S. Grant, Spanish Colonialism and the Ten Years' War in Cuba

This article examines the attitudes of leading policymakers in the United States toward the Spanish empire in Cuba during the Ten Years? War (1868-78). It suggests that while many in the US objected to Spanish imperial practices, concerns about trade alongside ideological predispositions regarding non-intervention and race led the administration of Ulysses S. Grant, under the direction of Secretary of State Hamilton Fish, to develop a series of policies that in effect supported colonialism in Cuba while attempting to ensure that the US would benefit from any change in rule there. The article argues that despite an apparent desire for the US to remain neutral during the conflict, the Grant administration in fact formulated its responses based on a narrow conception of Spanish colonial control that demonstrated an increasing sense of moral superiority over both colonizer and colonized

Magnetic reconnection in flux-tubes undergoing spinning footpoint motions

Aims. Photospheric motions acting on the coronal magnetic field have the potential to build up huge amounts of magnetic energy. The energy may be released through magnetic reconnection, and so a detailed understanding of the 3D process is crucial if its implications for coronal heating are to be fully addressed. Methods. A 3D MHD experiment is described in which misaligned magnetic flux tubes are subjected to simple spinning boundary motions. Results. The resulting shear between adjacent flux systems generates a twisted central separator current sheet that extends vertically throughout the domain. Current density is amplified to a sufficient extent that reconnection begins, and occurs everywhere along the separator current sheet, while the separatrix current sheets that exist in the early stages of the experiment are found to be unimportant in the systems dynamical evolution. In 2D cross-sections, the reconnection process exhibits many similarities to the regime of flux pile-up reconnection

Development of novel layered nanoparticles for more efficient cancer treatment.

Cancer is the second-most leading cause of death in the United States, with 1.66 million new cases expected to be diagnosed and over 580,000 Americans expected to die of cancer in 2013 alone. (American Cancer Society 2013) Current treatments result in damage to the healthy tissues and incomplete resections of solid tumors, but by harnessing nanotechnology, more effective treatments can be constructed. Gold nanoshells present a promising option for targeted cancer therapy. The anatomy of tumors causes the “enhanced permeability and retention” effect, which means that nano-scale particles will extravasate from the bloodstream and accumulate in the tumors. However, small nanoparticles must still diffuse from the tumor vasculature into the tumor tissue. Due to impaired vascularization, the particles are unable to reach into the entire tumor region. The purpose of our project is to create a “two-layer” nanoshell coated with alkanethiol and phosphatidlycholine and a “three-layer” nanoshell that coats the “two-layer” system with a layer of high-density lipoprotein. It is proposed that these coatings will allow for better penetration of solid tumors compared to the standard nanoshells modified with poly(ethylene glycol) (PEG). In addition to the nanoshells, citrate-gold nanoparticles were investigated as a control. Size, zeta potential, and morphology were optimized, and the penetration of the particles into solid tumors was investigated using dark-field microscopy. It was discovered that the “two-layer” nanoshells exhibited significantly more uptake into the solid tumors compared to PEGylated nanoshells, and should be further investigated as a platform for targeted cancer therapies

Scaling law for the heating of solar coronal loops

We report preliminary results from a series of numerical simulations of the reduced magnetohydrodynamic equations, used to describe the dynamics of magnetic loops in active regions of the solar corona. A stationary velocity field is applied at the photospheric boundaries to imitate the driving action of granule motions. A turbulent stationary regime is reached, characterized by a broadband power spectrum $E_k\simeq k^{-3/2}$ and heating rate levels compatible with the heating requirements of active region loops. A dimensional analysis of the equations indicates that their solutions are determined by two dimensionless parameters: the Reynolds number and the ratio between the Alfven time and the photospheric turnover time. From a series of simulations for different values of this ratio, we determine how the heating rate scales with the physical parameters of the problem, which might be useful for an observational test of this model.Comment: 12 pages, 4 figures. Astrophysical Journal Letters (in press

Towards Large-scale Inconsistency Measurement

We investigate the problem of inconsistency measurement on large knowledge bases by considering stream-based inconsistency measurement, i.e., we investigate inconsistency measures that cannot consider a knowledge base as a whole but process it within a stream. For that, we present, first, a novel inconsistency measure that is apt to be applied to the streaming case and, second, stream-based approximations for the new and some existing inconsistency measures. We conduct an extensive empirical analysis on the behavior of these inconsistency measures on large knowledge bases, in terms of runtime, accuracy, and scalability. We conclude that for two of these measures, the approximation of the new inconsistency measure and an approximation of the contension inconsistency measure, large-scale inconsistency measurement is feasible.Comment: International Workshop on Reactive Concepts in Knowledge Representation (ReactKnow 2014), co-located with the 21st European Conference on Artificial Intelligence (ECAI 2014). Proceedings of the International Workshop on Reactive Concepts in Knowledge Representation (ReactKnow 2014), pages 63-70, technical report, ISSN 1430-3701, Leipzig University, 2014. http://nbn-resolving.de/urn:nbn:de:bsz:15-qucosa-15056

High-Lundquist Number Scaling in Three-Dimensional Simulations of Parker's Model of Coronal Heating

Parker's model is one of the most discussed mechanisms for coronal heating and has generated much debate. We have recently obtained new scaling results in a two-dimensional (2D) version of this problem suggesting that the heating rate becomes independent of resistivity in a statistical steady state [Ng and Bhattacharjee, Astrophys. J., 675, 899 (2008)]. Our numerical work has now been extended to 3D by means of large-scale numerical simulations. Random photospheric footpoint motion is applied for a time much longer than the correlation time of the motion to obtain converged average coronal heating rates. Simulations are done for different values of the Lundquist number to determine scaling. In the high-Lundquist number limit, the coronal heating rate obtained so far is consistent with a trend that is independent of the Lundquist number, as predicted by previous analysis as well as 2D simulations. In the same limit the average magnetic energy built up by the random footpoint motion tends to have a much weaker dependence on the Lundquist number than that in the 2D simulations, due to the formation of strong current layers and subsequent disruption when the equilibrium becomes unstable. We will present scaling analysis showing that when the dissipation time is comparable or larger than the correlation time of the random footpoint motion, the heating rate tends to become independent of Lundquist number, and that the magnetic energy production is also reduced significantly.Comment: Accepted for publication in Astrophysical Journa