Charge Stripe in an Antiferromagnet: 1d Band of Composite Excitations

With the help of analytical and numerical studies of the $t$-$J_z$ model we argue that the charge stripe in an antiferromagnetic insulator should be understood as a system of holon-spin-polaron excitations condensed at the self-induced antiphase domain wall. The structure of such a charge excitation is studied in detail with numerical and analytical results for various quantities being in a very close agreement. An analytical picture of these excitations occupying an effective 1D stripe band is also in a very good accord with numerical data. The emerging concept advocates the primary role of the kinetic energy in favoring the stripe as a ground state. A comparative analysis suggests the effect of pairing and collective meandering on the energetics of the stripe formation to be secondary.Comment: 5 pages, 3 figures, proceedings of SCES'01 conference, Ann Arbor, 2001, to be published in Physica

Embedding realistic surveys in simulations through volume remapping

Connecting cosmological simulations to real-world observational programs is often complicated by a mismatch in geometry: while surveys often cover highly irregular cosmological volumes, simulations are customarily performed in a periodic cube. We describe a technique to remap this cube into elongated box-like shapes that are more useful for many applications. The remappings are one-to-one, volume-preserving, keep local structures intact, and involve minimal computational overhead.Comment: 4 pages, 4 figures. Companion material at http://mwhite.berkeley.edu/BoxRemap

How Autonomy Can Legitimate Beneficial Coercion

Respect for autonomy and beneficence are frequently regarded as the two essential principles of medical ethics, and the potential for these two principles to come into conflict is often emphasised as a fundamental problem. On the one hand, we have the value of beneficence, the driving force of medicine, which demands that medical professionals act to protect or promote the wellbeing of patients or research subjects. On the other, we have a principle of respect for autonomy, which demands that we respect the self-regarding decisions of individuals. As well as routinely coming into opposition with the demands of beneficence in medicine, the principle of respect for autonomy in medical ethics is often seen as providing protection against beneficial coercion (i.e. paternalism) in medicine. However, these two values are not as straightforwardly opposed as they may appear on the surface. In fact, the way that we understand autonomy can lead us to implicitly sanction a great deal of paternalistic action, or can smuggle in paternalistic elements under the guise of respect for autonomy. This paper is dedicated to outlining three ways in which the principle of respect for autonomy, depending on how we understand the concept of autonomy, can sanction or smuggle in paternalistic elements. As the specific relationship between respect for autonomy and beneficence will depend on how we conceive of autonomy, I begin by outlining two dominant conceptions of autonomy, both of which have great influence in medical ethics. I then turn to the three ways in which how we understand or employ autonomy can increase or support paternalism: firstly, when we equate respect for autonomy with respect for persons; secondly, when our judgements about what qualifies as an autonomous action contain intersubjective elements; and thirdly, when we expect autonomy to play an instrumental role, that is, when we expect people, when they are acting autonomously, to act in a way that promotes or protects their own wellbeing. I then provide a proposal for how we might work to avoid this. I will suggest that it may be impossible to fully separate paternalistic elements out from judgements about autonomy. Instead, we are better off looking at why we are motivated to use judgements about autonomy as a means of restricting the actions of patients or research subjects. I will argue that this is a result of discomfort about speaking directly about our beneficent motivations in medical ethics. Perhaps we can reduce the incentive to smuggle in these beneficent motivations under the guise of autonomy by talking directly about beneficent motivations in medicine. This will also force us to recognise paternalistic motivations in medicine when they appear, and to justify paternalism where it occurs

Teaching Queer Cinema With Independent Media

In lieu of an abstract, this is the article\u27s introductory paragraph: One of the most exciting dimensions of teaching film (and popular culture) is learning what students already know and then generating an informed and critical epistemology from the familiar. Teaching LGBT (lesbian, gay, bisexual, and transgender) representation in film and media presents rich opportunities to build on student familiarity — with such mainstream breakthroughs as Ang Lee’s Brokeback Mountain (2006) and Queer Eye for the Straight Guy (2003-07) — and to formalize the knowledge and challenge the assumptions that students have about LGBT history, lives, and struggles for representation. With the commercial success of gay-themed work and the acceptance of such out celebrities as Ellen Degeneres, the recent past is a teachable moment of both social transformation and market logic, and students of diverse backgrounds have illuminating perspectives on and important stakes in making sense of it. By focusing on film and media by and about LGBT producers, teachers can connect questions of political and aesthetic representation and expose students to independent media sources