On the Anisotropic Nature of MRI-Driven Turbulence in Astrophysical Disks

The magnetorotational instability is thought to play an important role in enabling accretion in sufficiently ionized astrophysical disks. The rate at which MRI-driven turbulence transports angular momentum is related to both the strength of the amplitudes of the fluctuations on various scales and the degree of anisotropy of the underlying turbulence. This has motivated several studies of the distribution of turbulent power in spectral space. In this paper, we investigate the anisotropic nature of MRI-driven turbulence using a pseudo-spectral code and introduce novel ways to robustly characterize the underlying turbulence. We show that the general flow properties vary in a quasi-periodic way on timescales comparable to 10 inverse angular frequencies motivating the temporal analysis of its anisotropy. We introduce a 3D tensor invariant analysis to quantify and classify the evolution of the anisotropic turbulent flow. This analysis shows a continuous high level of anisotropy, with brief sporadic transitions towards two- and three-component isotropic turbulent flow. This temporal-dependent anisotropy renders standard shell-average, especially when used simultaneously with long temporal averages, inadequate for characterizing MRI-driven turbulence. We propose an alternative way to extract spectral information from the turbulent magnetized flow, whose anisotropic character depends strongly on time. This consists of stacking 1D Fourier spectra along three orthogonal directions that exhibit maximum anisotropy in Fourier space. The resulting averaged spectra show that the power along each of the three independent directions differs by several orders of magnitude over most scales, except the largest ones. Our results suggest that a first-principles theory to describe fully developed MRI-driven turbulence will likely have to consider the anisotropic nature of the flow at a fundamental level.Comment: 13 pages, 13 figures, submitted to Ap

Development of taxane resistance in a panel of human lung cancer cell lines

Using a selection process designed to reflect clinically relevant conditions, a panel of taxane-selected variants were developed to study further the mechanisms of resistance in lung cancer. Unlike continuous or pulse exposure to high concentrations of chemotherapeutic drugs which yield high resistance and often cross resistance, most variants developed here displayed low level resistance to the selecting drug with slight cross-resistance. Pulsing with taxol resulted in more highly resistant clones (up to 51.4-fold). Analysis of taxol and taxotere in the four major lung cancer cell types showed the taxanes to be more effective against NSCLC (with the exception of SKMES-taxane selected variants) than against the SCLC. Comparison of taxol and taxotere shows that taxol induces higher levels of resistance than taxotere. Further, in taxotere-selected cell lines, the cells are more resistant to taxol than taxotere, suggesting that taxotere may be a superior taxane from a clinical view. Taxol treatment resulted in increased cross-resistance to 5-FU in all classes of lung cancer except DMS-53. The high levels of Pgp in the DMS-53 and selected variant suggests this mechanism is not related to Pgp expression. Analysis of the Pgp and MRP-1 status by combination inhibitory assays and Western blotting showed no consistent relationship between expression of the membrane pumps Pgp or MRP-1 and resistance. However, where high level resistance was seen, the parent cell line expressed Pgp or MRP-1 and was accompanied by increased levels in the variants. Overall we found that the clinically relevant models used here are useful for investigating mechanisms of taxane resistance

Blanco White y los «Desdichados españoles»

José María Blanco White used his social connections in London for the benefit of less fortunate compatriots, afrancesados as well as liberales, by obtaining subsistence grants for them from the Royal Literary Fund, a charity founded for the relief of writers in need, of which his close friend James Christie was Registrar.José María Blanco White empleó sus contactos sociales en Londres en beneficio de sus compatriotas menos afortunados, tanto afrancesados como liberales, obteniendo subsidios para ellos del Royal Literary Fund, institución caritativa fundada para el socorro de escritores necesitados, de la cual su íntimo amigo James Christie era Secretario

Edward Churton y Hugh James Rose: dos hispanófilos victorianos

For some curiosos impertinentes of the Victorian era Spain offered a means of escape and self-discovery. Edward Churton, an Archdeacon and theologian, was a hispanist a distancia who fell in love with Spanish poetry and, in his remote Yorkshire rectory, wrote the first scholarly study of Góngora to be published in England. By contrast, Hugh James Rose, no intellectual, lived «among the Spanish people» (the title of one of his two books), first at Linares and later at Cadiz and Madrid, learning lessons in the art of living. His wide-ranging and sympathetic observations are of value to social historians.Para algunos «curiosos impertinentes» de la era victoriana, España proporcionó un medio de escape y de autodescubrimiento. Edward Churton, archidiácono y teólogo, fue un hispanista a distancia que se enamoró de la poesía española y, desde su remota rectoría en Yorkshire, escribió el primer estudio académico sobre Góngora que se publicó en Inglaterra. Por el contrario, Hugh James Rose no fue un intelectual, sino que vivió «entre el pueblo español» (el título de uno de sus dos libros), primero en Linares y después en Cádiz y Madrid, tomando lecciones del arte de vivir. Sus observaciones, empáticas y de amplios intereses, poseen valor para los historiadores sociales

Piracy

(MIWS/05 - Maritime Irregular Warfare Studies, book 5) Piracy, by Dr. Martin Murphy, examines the security challenges created by piracy around the Horn of Africa. Murphy examines the linkages between piracy and weak states, in addition to considering the threat piracy poses to shipping and global trade. In particular, he argues that Somali pirates have proved to be masters of adaptation, both strategically and tactically, as they exploit the chaos within Somalia and in the international maritime order. Moreover, Somali piracy cannot be seen in isolation from the wider geostrategic issues of free movement and safe passage to trade between Europe and Asia, and the shipment of oil from the Arabian Gulf to the rest of the world.https://digital-commons.usnwc.edu/ciwag-case-studies/1003/thumbnail.jp

Sound and Vision: Marketing Recorded Music in the Age of Radio

In the early 1930s, the popularity of radio and the economic austerity of the Great Depression threatened to make the phonograph record obsolete. However, by the time the United States entered World War II in 1941, records were returning to popularity. This return coincided with the first instances of the appearance of unique cover artwork on record albums. This thesis explores the cultural and industrial factors that converged in the late 1930s to make album artwork viable in ways that it would not have been earlier. This thesis also investigates how RCA Victor and Columbia, two record companies that had been acquired by national radio broadcasters, found increasingly visual ways to market records to potential audiences through magazine advertising, catalogs, and album artwork itself. An investigation of this historical moment provides insights that are relevant to contemporary concerns about the future of the recording industry

Suppression of Piracy and Maritime Terrorism

On 12 October 2000, two men from an organization aligned with al-Qa‘ida loaded a rigid raider (a small boat with glass-reinforced-plastic hull) withexplosives and drove it into the side of the guided-missile destroyer USS Cole (DDG 67). Seventeen sailors lost their lives. This was a seminal event. It epitomized small war versus “big” war and the threat that small-war tactics could present to “big war” fleets. It was also an echo of the U.S. Navy’s past. As the initial alarm faded, the Navy’s response became largely inward looking and defensive, limited for the most part to the implementation of more robust force-protection measures

Pirates, Ports, and Coasts in Asia: Historical and Contemporary Perspectives

These two books from the Institute of Southeast Asian Studies Press share one single characteristic—a long delay between authorship and publication. This has no appreciable effect on Kleinen and Osseweijer’s edited collection, based on a 2005 confer- ence, but it ill serves Carolin Liss. She evidently completed her book in 2006. Since then, however, vari- ous maritime-security initiatives in the region whose births she observed, including the various Malacca Strait patrols and the ReCAAP information exchange, have matured. It would have been interesting to have her views on the decline in major incidents that gathered pace starting in 2005—as to the degree to which they contributed to this decline, and what caused the recent modest uptick in numbers

Brown Waters of Africa: Portuguese Riverine Warfare, 1961–1974

Counterinsurgency warfare is what used to be called “colonial warfare.” Although the association might make some people uncomfortable—Americans perhaps more than most, given their aversion to colonialism—much of the strategic intent and many of the tactics, techniques, and procedures of modern counterinsurgency derive directly from the colonial wars and police actions of the past