Structuralism about mathematical objects and structuralist accounts of physical computation both face indeterminacy objections. For the former, the problem arises for cases such as the complex roots i and \, for which a automorphism can be defined, thus establishing the structural identity of these importantly distinct mathematical objects. In the case of the latter, the problem arises for logical duals such as AND and OR, which have invertible structural profiles :369–400, 2001). This makes their physical implementations indeterminate, in the sense (...) that their structural profiles alone cannot establish whether a given physical component is an AND-gate or an OR-gate. Doherty has recently shown both problems to be analogous, and has argued that computational structuralism is threatened with the absurd conclusion that computational digits might be indiscernible, such that, if structural properties are all that we have to go on, the binary digit 0 must be treated as identical to the binary digit 1. However, we think that a solution to the indiscernibility problem for mathematical structuralists, drawing on the work of David Hilbert, can be adapted for the analogous problem in the computational case, thereby rescuing the structuralist approach to physical computation. (shrink)

In this paper, we discuss the macroscopic quantum behavior of simple superconducting circuits. Starting from a Lagrangian for electromagnetic field with broken gauge symmetry, we construct a quantum circuit model for a superconducting weak link (SQUID) ring, together with the appropriate canonical commutation relations. We demonstrate that this model can be used to describe macroscopic excitations of the superconducting condensate and the localized charge states found in some ultrasmall-capacitance weak-link devices.

The statistical properties of a single quantum object and an ensemble of independent such objects are considered in detail for two-level systems. Computer simulations of dynamic zero-point quantum fluctuations for a single quantum object are reported and compared with analytic solutions for the ensemble case.

We propose a new approach to describe quantum mechanics as a manifestation of non-Euclidean geometry. In particular, we construct a new geometrical space that we shall call Qwist. A Qwist space has a extra scalar degree of freedom that ultimately will be identified with quantum effects. The geometrical properties of Qwist allow us to formulate a geometrical version of the uncertainty principle. This relativistic uncertainty relation unifies the position-momentum and time-energy uncertainty principles in a unique relation that recover both of (...) them in the non-relativistic limit. (shrink)

Some factors affecting marital distances have been studied in two Outer Hebridean islands, Harris (843 marriages) and Barra (444 marriages), over the period 1855-1990. In each island marital distances fell before 1900, but then rose to their greatest values after the 1950s. Fishermen generally married at the shortest distances and men in land-based occupations at the longest. The depression in the fishing industry during the 1880s and early 1890s was associated with reductions in marital distances, especially among fishermen. In the (...) different regions of Harris, marital distances were least in the south-east, where settlement was most dense, and greatest in the south-west where it was most sparse. (shrink)

Body integrity identity disorder is a very rare condition in which people experience long-standing anguish because there is a mismatch between their bodies and their internal image of how their bodies should be. Most typically, these people are deeply distressed by the presence of what they openly acknowledge as a perfectly normal leg. Some with the condition request that their limb be amputated. 1 We and others have argued that such requests should be acceded to in carefully selected patients.1–4 Consistent (...) with this view, a group at the University of Sydney is developing a programme to better understand and treat BIID and to offer amputation if appropriate. In a recent paper, Patrone argues that such amputations should be prohibited.5 He suggests that authors supporting amputation in BIID depend on analogies with more familiar conditions and then claim that the ‘the desires, choices and requests of BIID patients should be held to exactly the same standards and treated with exactly the same respect as the desires, choices and requests of any more conventional patient’.5 He believes that these analogies are invalid and that therefore the arguments for amputation are invalid.Patrone concentrates a great deal upon whether a decision to have a particular medical intervention is to be regarded as ‘rational’. Unfortunately, he makes no attempt to define what he …. (shrink)

Substrate cycles are ubiquitous structures of the cellular metabolism (e.g. Krebs cycle, fatty acids -oxydation cycles, etc... ). Moiety-conserved cycles (e.g. adenine nucleotides and NADH/NAD, etc...) are also important.The role played by such cycles in the metabolism and its regulation is not clearly understood so far. However, it was shown that these cycles can generate multistationarity (bistability), irreversible transitions, enhancement of sensitivity, temporal oscillations and chaotic motions (Hervagault & Canu, 1987; Hervagault & Cimino, 1989; Reich & Sel'kov, 1981; Ricard & (...) Soulié, 1982). Fig. 1: Scheme of the open binary substrate cycle under study. The substrate S is converted into P with a net rate v2. Substrate P is converted in turn into S with a net rate v3. Step v2 is inhibited by excess of the substrate, S. In addition, the cycle operates under open conditions, that is zero-order input of S at rates \ga0(v1) and first order outputs of S and P at rates \gaS and \gaP(v4), respectively. (shrink)

Through discourse with international groups of physicians, we conducted a cross-cultural analysis of the types of ethical dilemmas physicians face. Qualitative analysis was used to categorise the dilemmas into seven themes, which we compared among the physicians by country of practice. These themes were a-theoretically-driven and grounded heavily within the text. We then subjected the dilemmas to an analysis of moral intensity, which represents an important theoretical perspective of ethical decision making. These constructs represent salient determinants of ethical behaviour and (...) our cross-cultural sample afforded us the opportunity to consider both the pragmatic aspects of culture, as they are perceived by physicians, as well as the theory-driven concept of moral intensity. By examining both culture and moral intensity, we hope to better elucidate the complexities of ethical decision-making determinants among physicians in their daily practice. Doing so may potentially have practical implications for ethics training of medical students and foreign physicians. (shrink)