Affective Life and Cultural Economy: Payday Loans and the Everyday Space-Times of Credit-Debt in the UK

Analysing the affective geographies of digitally mediated payday loans in the UK, this paper advocates and exemplifies an approach to cultural economy that focuses on how economic worlds are affectively animated and lived. Supplementing the two versions of ‘culture’ that cultural economy approaches have to date been organised around – culture as signifying system, or culture as assembled effect ‐ we propose a cultural economy of everyday space‐times which is attuned to the affective composition of forms of living. Drawing on empirical work with forty users of digitally mediated payday loans, we employ this approach to trace how their loans become part of three intersecting forms of living: relief, as a pressing concern is deferred to the immediate future; separation, as private spaces are created within ordinary life and obligations are felt as individual responsibilities; and pressure, as demands to pay intensify the sense that debt is spiralling out of control and already ongoing precarity cannot be sustained. In conclusion, we pose further questions for a cultural economy approach orientated to the analysis of forms of living

A Comparison of Biofeedback and Occlusal Adjustment on Bruxism

Peer Reviewedhttps://deepblue.lib.umich.edu/bitstream/2027.42/141944/1/jper0367.pd

Minimal supporting subtrees for the free energy of polymers on disordered trees

We consider a model of directed polymers on a regular tree with a disorder given by independent, identically distributed weights attached to the vertices. For suitable weight distributions this model undergoes a phase transition with respect to its localization behaviour. We show that, for high temperatures, the free energy is supported by a random tree of positive exponential growth rate, which is strictly smaller than that of the full tree. The growth rate of the minimal supporting subtree is decreasing to zero as the temperature decreases to the critical value. At the critical value and all lower temperatures, a single polymer suffices to support the free energy. Our proofs rely on elegant martingale methods adapted from the theory of branching random walks.Comment: 22 pages, 3 figures, to be published in the special issue of JMP, 'Statistical Mechanics on Random Structures

Information capacity in the weak-signal approximation

We derive an approximate expression for mutual information in a broad class of discrete-time stationary channels with continuous input, under the constraint of vanishing input amplitude or power. The approximation describes the input by its covariance matrix, while the channel properties are described by the Fisher information matrix. This separation of input and channel properties allows us to analyze the optimality conditions in a convenient way. We show that input correlations in memoryless channels do not affect channel capacity since their effect decreases fast with vanishing input amplitude or power. On the other hand, for channels with memory, properly matching the input covariances to the dependence structure of the noise may lead to almost noiseless information transfer, even for intermediate values of the noise correlations. Since many model systems described in mathematical neuroscience and biophysics operate in the high noise regime and weak-signal conditions, we believe, that the described results are of potential interest also to researchers in these areas.Comment: 11 pages, 4 figures; accepted for publication in Physical Review

An extension of Wiener integration with the use of operator theory

With the use of tensor product of Hilbert space, and a diagonalization procedure from operator theory, we derive an approximation formula for a general class of stochastic integrals. Further we establish a generalized Fourier expansion for these stochastic integrals. In our extension, we circumvent some of the limitations of the more widely used stochastic integral due to Wiener and Ito, i.e., stochastic integration with respect to Brownian motion. Finally we discuss the connection between the two approaches, as well as a priori estimates and applications.Comment: 13 page

The mass of the neutron star in Vela X-1 and tidally induced non-radial oscillations in GP Vel

We report new radial velocity observations of GP Vel/HD77581, the optical companion to the eclipsing X-ray pulsar Vela X-1. Using data spanning more than two complete orbits of the system, we detect evidence for tidally induced non-radial oscillations on the surface of GP Vel, apparent as peaks in the power spectrum of the residuals to the radial velocity curve fit. By removing the effect of these oscillations (to first order) and binning the radial velocities, we have determined the semi-amplitude of the radial velocity curve of GP Vel to be K_o=22.6+/-1.5 km/s. Given the accurately measured semi-amplitude of the pulsar's orbit, the mass ratio of the system is 0.081+/-0.005. We are able to set upper and lower limits on the masses of the component stars as follows. Assuming GP Vel fills its Roche lobe then the inclination angle of the system, i=70.1+/-2.6 deg. In this case we obtain the masses of the two stars as M_x=2.27 +/-0.17 M_sun for the neutron star and M_o=27.9+/-1.3 M_sun for GP Vel. Conversely, assuming the inclination angle is i=90 deg, the ratio of the radius of GP Vel to the radius of its Roche lobe is beta=0.89+/-0.03 and the masses of the two stars are M_x=1.88+/-0.13 M_sun and M_o=23.1+/-0.2 M_sun. A range of solutions between these two sets of limits is also possible, corresponding to other combinations of i and beta. In addition, we note that if the zero phase of the radial velocity curve is allowed as a free parameter, rather than constrained by the X-ray ephemeris, a significantly improved fit is obtained with an amplitude of 21.2+/-0.7 km/s and a phase shift of 0.033+/-0.007 in true anomaly. The apparent shift in the zero phase of the radial velocity curve may indicate the presence of an additional radial velocity component at the orbital period.Comment: Accepted for publication in Astronomy & Astrophysic

A Classical Bound on Quantum Entropy

A classical upper bound for quantum entropy is identified and illustrated, $0\leq S_q \leq \ln (e \sigma^2 / 2\hbar)$, involving the variance $\sigma^2$ in phase space of the classical limit distribution of a given system. A fortiori, this further bounds the corresponding information-theoretical generalizations of the quantum entropy proposed by Renyi.Comment: Latex2e, 7 pages, publication versio

Epistemic roles of materiality within a collaborative invention project at a secondary school

In this study, we examined maker‐centred learning from an epistemic perspective, highlighting the agentic role of material engagement and artefacts in learning and creativity. The use of physical materials plays a crucial role in maker activities where the socio‐epistemic aspects of knowledge creation entangle with the designing and making of physical artefacts. By taking a case study perspective, we analysed video data from nine design sessions involving a team of students (aged 13 to 14) developing an invention. First, we analysed knowledge that was built during the process. Our analysis revealed how design ideas evolved from preliminary to final stages and, together with the expressed design problems and conversations preceding the ideas, formed an epistemic object pursued by the team. Next, we included non‐human agencies into the analysis to understand the role of materials in the process. Features of materials and human design intentions both constrained and enabled idea improvement and knowledge creation, intermixing meanings and materials. Material making invited the students to not only rely on human rationalisation, but also to think together with the materials.In this study, we examined maker-centred learning from an epistemic perspective, highlighting the agentic role of material engagement and artefacts in learning and creativity. The use of physical materials plays a crucial role in maker activities where the socio-epistemic aspects of knowledge creation entangle with the designing and making of physical artefacts. By taking a case study perspective, we analysed video data from nine design sessions involving a team of students (aged 13 to 14) developing an invention. First, we analysed knowledge that was built during the process. Our analysis revealed how design ideas evolved from preliminary to final stages and, together with the expressed design problems and conversations preceding the ideas, formed an epistemic object pursued by the team. Next, we included non-human agencies into the analysis to understand the role of materials in the process. Features of materials and human design intentions both constrained and enabled idea improvement and knowledge creation, intermixing meanings and materials. Material making invited the students to not only rely on human rationalisation, but also to think together with the materials.Peer reviewe

On the origin of ambiguity in efficient communication

This article studies the emergence of ambiguity in communication through the concept of logical irreversibility and within the framework of Shannon's information theory. This leads us to a precise and general expression of the intuition behind Zipf's vocabulary balance in terms of a symmetry equation between the complexities of the coding and the decoding processes that imposes an unavoidable amount of logical uncertainty in natural communication. Accordingly, the emergence of irreversible computations is required if the complexities of the coding and the decoding processes are balanced in a symmetric scenario, which means that the emergence of ambiguous codes is a necessary condition for natural communication to succeed.Comment: 28 pages, 2 figure