Tkachenko modes in rotating neutron stars: the effect of compressibility and implications for pulsar timing noise

Long wavelength oscillations (Tkachenko waves) of the triangular lattice of quantized vortices in superfluid neutron stars have been suggested as one of the possible explanations for the timing noise observed in many radio pulsars, in particular for the 100-1000 day variations in the spin of PSR B1828-11. Most studies to date have, however, been based on the hydrodynamics developed for superfluid Helium. In this paper we extend the formulation to a two fluid neutron and proton system, relevant for neutron star interiors and include the effect of chemical coupling, compressibility and mutual friction between the components. In particular we find that chemical coupling and compressibility can have a drastic effect on the mode structure. However, for the slower pulsars rotating at 1-10 Hz (such as PSR 1828-11), most choices of parameters in the equation of state lead to Tkachenko oscillations with frequencies in the correct range to explain the timing noise. We also investigate the case of more rapidly rotating pulsars (above 100 Hz) for which we find that there is a vast portion of parameter space in which there are no Tkachenko modes, but only modified sound waves at much higher frequencies

'cultivated, / Wild, exotic': Nationalism and Internationalism in the Poetry of Shirley Geok-lin Lim

Born in multicultural Malacca during British rule, educated there and later in Kuala Lumpur and Boston, a long-time resident of the USA and a visiting professor to many countries, Shirley Geok-lin Lim seems a transnational writer par excellence. Yet much of her later work involves looking back to Malacca, “at a loss here, / Loosening my grip on yesterday,” afraid of losing “[s]hades of father and mother.” She is the author of poems, short stories, novels and a memoir, as well as literary and social criticism. The memoir, Among the White Moon Faces, is subtitled, “An Asian-American Memoir of Homelands,” and the plural noun is notable. Concentrating on her poetry, this paper charts her shifting sense of identity as Malaccan, Malaysian, American and as a woman of Chinese heritage whose language is English, through “[s]peech which is sufficient enterprise,” even though in these late poems she can feel “unmoored” and sense “the gravity / of the unmade I.

Evangelical Christians in Canadian National Television News, 1994–2004: A Frame Analysis

Recent surveys have shown that most evangelical Christians in Canada believe that the news media treat them unfairly. This study empirically tested the validity of the evangelicals’ charge against the media by examining the frames used in the nightly, national news reports of Global, CBC and CTV television networks. An analysis of all reports featuring evangelicals showed that neutral and positive frames, together, were almost equal in strength and number to negative frames used; this resulted in an overall rating of “balanced” for the coverage. While overall the coverage was balanced, the frequency and exclusivity of certain negative frames elevated their saliency considerably. For example, the “evangelicals as intolerant” frame alone appeared in one quarter of all reports. Regarding topic of the news reports, evangelicals most often received coverage for involvement in politics followed closely by involvement in criminal or immoral actions. Implications of these results are discussed