Decoherence of a single-ion qubit immersed in a spin-polarized atomic bath

We report on the immersion of a spin-qubit encoded in a single trapped ion into a spin-polarized neutral atom environment, which possesses both continuous (motional) and discrete (spin) degrees of freedom. The environment offers the possibility of a precise microscopic description, which allows us to understand dynamics and decoherence from first principles. We observe the spin dynamics of the qubit and measure the decoherence times (T1 and T2), which are determined by the spin-exchange interaction as well as by an unexpectedly strong spin-nonconserving coupling mechanism

Myocardium wall thickness transducer and measuring method

A miniature transducer for measuring changes of thickness of the myocardium is described. The device is easily implantable without traumatizing the subject, without affecting the normal muscle behavior, and is removable and implantable at a different muscle location. Operating features of the device are described

Catheter tip force transducer for cardiovascular research

A force transducer for measuring dynamic force activity within the heart of a subject essentially consists of a U-shaped beam of low elastic compliance material. Two lines extend from the beams's legs and a long coil spring is attached to the beam. A strain gauge is coupled to one of the beam's legs to sense deflections thereof. The beam with the tines and most of the spring are surrounded by a flexible tube, defining a catheter, which is insertable into a subject's heart through an appropriate artery. The tines are extractable from the catheter for implantation into the myocardium by pushing on the end of the spring which extends beyond the external end of the catheter

Semantic modelling of user interests based on cross-folksonomy analysis

The continued increase in Web usage, in particular participation in folksonomies, reveals a trend towards a more dynamic and interactive Web where individuals can organise and share resources. Tagging has emerged as the de-facto standard for the organisation of such resources, providing a versatile and reactive knowledge management mechanism that users find easy to use and understand. It is common nowadays for users to have multiple profiles in various folksonomies, thus distributing their tagging activities. In this paper, we present a method for the automatic consolidation of user profiles across two popular social networking sites, and subsequent semantic modelling of their interests utilising Wikipedia as a multi-domain model. We evaluate how much can be learned from such sites, and in which domains the knowledge acquired is focussed. Results show that far richer interest profiles can be generated for users when multiple tag-clouds are combine

The Starburst in the Central Kiloparsec of Markarian 231

We present VLBA observations at 0.33 and 0.61 GHz, and VLA observations between 5 and 22 GHz, of subkiloparsec scale radio emission from Mrk 231. In addition to jet components clearly associated with the AGN, we also find a smooth extended component of size 100 - 1000 pc most probably related to the purported massive star forming disk in Mrk 231. The diffuse radio emission from the disk is found to have a steep spectrum at high frequencies, characteristic of optically thin synchrotron emission. The required relativistic particle density in the disk can be produced by a star formation rate of 220 Msolar/yr in the central kiloparsec. At low frequencies the disk is absorbed, most likely by ionized gas with an emission measure of 8 x 10^5 pc cm-6. We have also identified 4 candidate radio supernovae that, if confirmed, represent direct evidence for ongoing star formation in the central kiloparsec.Comment: in press at ApJ for v. 519 July 1999, 14 page LaTeX document includes 6 postscript figure

Navigating the city: dialectics of everyday urbanism

How might we conceptualise and research everyday urbanism? By examining the making of everyday life in a low-income neighbourhood in Uganda, we argue that a dialectics of everyday urbanism is a useful approach for understanding urban poverty. This dialectical approach examines how marginalised urban dwellers navigate the city in the relative absence of formal infrastructure systems, service provision and state welfare, and in turn exceed those limitations through forging connections, capacities and opportunities. We reveal the ‘social infrastructures’ that people put together to sustain life, as well as the limits of and placed on these infrastructures, from the legacies of structural adjustment to ongoing forms of demolition and disinvestment. We identify a set of practices that operate alongside social infrastructure – ‘coordination’, ‘consolidation’ and ‘speculation’ – important in the composition of everyday urban life. In doing so, we reflect on how we might research the dialectics of everyday urbanism, and here a ‘follow-along participant observation’ (FAPO) methodology has significant potential. Our arguments emerge from research with residents in Kampala, but open out questions for how we conceive and research everyday life and urban infrastructure more generally

Moderately elevated corticosterone levels increase mate choosiness in female Cope’s gray treefrogs without impacting sexual proceptivity or preferences

Female mate choice and its effects on sexual selection have largely been considered with regard to sex steroids; however, an increasing body of literature suggests that glucocorticoids have important effects on female mate choice behavior. Females must balance current reproductive efforts against survival and future reproductive efforts, thereby incurring substantial tradeoffs while breeding. Glucocorticoid levels are elevated during the breeding season and are also produced in response to environmental stressors. To test the hypothesis that elevated glucocorticoids degrade female mate choice by interrupting the energetic demands required for reproduction, I assessed the impact of elevated corticosterone (CORT) on aspects of female mate choice in wild gray tree frogs (Hyla chrysoscelis). Those aspects consisted of proceptivity, preference for high pulse number, and choosiness. Female frogs were collected in amplexus and tested using two-choice phonotaxis assays. A thirty-minute rest period shortened approach latencies and injection per se appeared to weaken one measure of preference for high pulse number calls. However, elevated CORT levels did not impact either proceptivity or species-typical preferences, providing evidence that seasonal breeders are buffered against high concentrations of CORT that might jeopardize reproductive investment. On the other hand, a medium CORT dose significantly increased choosiness in females, though this effect was not seen with either higher or lower CORT doses. This suggests that CORT modulates energetic tradeoffs in a non-linear dose response fashion

Flattening the World of Legal Services? The Ethical and Liability Minefields of Offshoring Legal and Law-Related Services

This article examines offshore outsourcing of legal and law-related services as the newest twist in the international market for legal services. We consider the impact of offshore outsourcing on the profession generally and analyze the ethical issues raised by offshore outsourcing, both as it exists today and as the practice may develop in the future. The article begins by situating offshore outsourcing in the framework of relationships created in the context of delivery of legal services. This framework is used, in turn, to construct a structure of analysis for the ethical implications of offshore outsourcing. Lawyers who outsource to offshore providers must conduct an investigation to ensure that the referral is appropriate. We also consider the potential reputation and economic benefits and disadvantages to law firms and legal departments in outsourcing offshore. We find that offshore outsourcing creates new opportunities for non-U.S. lawyers without putting them on equal footing with lawyers trained and licensed in the U.S. Instead, as with many aspects of globalization, offshore outsourcing emphasizes the divisions already present in the legal profession

Control of the finite size corrections in exact diagonalization studies

We study the possibility of controlling the finite size corrections in exact diagonalization studies quantitatively. We consider the one- and two dimensional Hubbard model. We show that the finite-size corrections can be be reduced systematically by a grand-canonical integration over boundary conditions. We find, in general, an improvement of one order of magnitude with respect to studies with periodic boundary conditions only. We present results for ground-state properties of the 2D Hubbard model and an evaluation of the specific heat for the 1D and 2D Hubbard model.Comment: Phys. Rev. B (Brief Report), in pres

Flattening the World of Legal Services? The Ethical and Liability Minefields of Offshoring Legal and Law-Related Services

This article examines offshore outsourcing of legal and law-related services as the newest twist in the international market for legal services. We consider the impact of offshore outsourcing on the profession generally and analyze the ethical issues raised by offshore outsourcing, both as it exists today and as the practice may develop in the future. The article begins by situating offshore outsourcing in the framework of relationships created in the context of delivery of legal services. This framework is used, in turn, to construct a structure of analysis for the ethical implications of offshore outsourcing. Lawyers who outsource to offshore providers must conduct an investigation to ensure that the referral is appropriate. We also consider the potential reputation and economic benefits and disadvantages to law firms and legal departments in outsourcing offshore. We find that offshore outsourcing creates new opportunities for non-U.S. lawyers without putting them on equal footing with lawyers trained and licensed in the U.S. Instead, as with many aspects of globalization, offshore outsourcing emphasizes the divisions already present in the legal profession