Thermally-driven Neutron Star Glitches

We examine the thermal and dynamical response of a neutron star to a sudden perturbation of the inner crust temperature. During the star's evolution, starquakes and other processes may deposit \gap 10^{42} ergs, causing significant internal heating and increased frictional coupling between the crust and the more rapidly rotating neutron superfluid the star is expected to contain. Through numerical simulation we study the propagation of the thermal wave created by the energy deposition, the induced motion of the interior superfluid, and the resulting spin evolution of the crust. We find that energy depositions of $\sim 10^{40}$ ergs produce gradual spin-ups above the timing noise level, while larger energy depositions produce sudden spin jumps resembling pulsar glitches. For a star with a temperature in the observed range of the Vela pulsar, an energy deposition of $\sim 10^{42}$ ergs produces a large spin-up taking place over minutes, similar to the Vela ``Christmas'' glitch. Comparable energy deposition in a younger and hotter ``Crab-like'' star produces a smaller spin-up taking place over $\sim 1$ day, similar to that seen during the partially time-resolved Crab glitch of 1989.Comment: 21 pages plus 17 figures, uuencode compressed Postscript. Accepted for publication in the Astrophysical Journa

Difficulties in the privatisation and reorganisation of the agricultural enterprises in Russia

Presently Russia is experiencing the complicated process of transforming the economic system of central planning into a socially oriented market economy. Of great importance for the success of this process is the institutional reshaping of the agricultural sector, particularly the privatisation of land and assets. In this paper the procedure and the problems of privatising Russian agriculture are extensively discussed against the background of the unfavourable development of the Russian agricultural sector. -- G E R M A N V E R S I O N: Gegenwärtig durchläuft Rußland einen komplizierten Prozeß der Transformation des zentral geplanten Wirtschaftssystems in eine soziale Marktwirtschaft. Von großer Bedeutung für den Erfolg dieses Prozesses ist der institutionelle Wandel des landwirtschaftlichen Sektors, insbesondere die Privatisierung von Land und sonstigem Vermögen. Vor dem Hintergrund der ungünstigen Entwicklung der russischen Landwirtschaft werden in dieser Arbeit die Vorgehensweise und die Probleme der russischen Landwirtschaft ausführlich diskutiert.

Convex regions in the plane and their domes

We make a detailed study of the relation of a euclidean convex region $\Omega \subset \mathbb C$ to $\mathrm{Dome} (\Omega)$. The dome is the relative boundary, in the upper halfspace model of hyperbolic space, of the hyperbolic convex hull of the complement of $\Omega$. The first result is to prove that the nearest point retraction $r: \Omega \to \mathrm{Dome} (\Omega)$ is 2-quasiconformal. The second is to establish precise estimates of the distortion of $r$ near $\partial \Omega$

A Case of Pernicious Anaemia

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The inevitability of unconditionally deleterious substitutions during adaptation

Studies on the genetics of adaptation typically neglect the possibility that a deleterious mutation might fix. Nonetheless, here we show that, in many regimes, the first substitution is most often deleterious, even when fitness is expected to increase in the long term. In particular, we prove that this phenomenon occurs under weak mutation for any house-of-cards model with an equilibrium distribution. We find that the same qualitative results hold under Fisher's geometric model. We also provide a simple intuition for the surprising prevalence of unconditionally deleterious substitutions during early adaptation. Importantly, the phenomenon we describe occurs on fitness landscapes without any local maxima and is therefore distinct from "valley-crossing". Our results imply that the common practice of ignoring deleterious substitutions leads to qualitatively incorrect predictions in many regimes. Our results also have implications for the substitution process at equilibrium and for the response to a sudden decrease in population size.Comment: Corrected typos and minor errors in Supporting Informatio

Medical and educational problems of the brain-injured child

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Translating National History for Children: A Case Study of Adventures of Huckleberry Finn

Mark Twain's classic novel Adventures of Huckleberry Finn is arguably about the history of the United States in terms of slavery and race relations. How, then, can this be translated to another language and culture, especially one with a very diferent background in regard to minorities? And in particular, how can this be translated for children, who have less knowledge about history and slavery than adult readers? In this article, I analyse how Twain's novel has been translated to Swedish. I study 15 translations. Surprisingly, I ind that instead of retaining Twain's even-handed portrayal of the two races and his acceptance of a wide variety of types of Americans, Swedish translators tend to emphasise the foreignness, otherness, and lack of education of the black characters. In other words, although the American setting is kept, the translators nevertheless give Swedish readers a very diferent understanding of the United States and slavery than that which Twain strove to give his American readers. his may relect the diferences in immigration and cultural makeup in Sweden versus in America, but it radically changes the book as well as child readers' understanding of what makes a nation