The Virtual Runner Learning Game

A learning game has been developed which allows learners to study and learn about the significance of three important variables in human physiology (lactate, glycogen, and hydration) and their influence on sports performance during running. The player can control the speed of the runner, and as a consequence the resulting physiological processes are simulated in real-time. The performance degradation of the runner due to these processes requires that different strategies for pacing the running speed are applied by the player, depending on the total length of the run. The game has been positively evaluated in a real learning context of academic physiology teaching

The stars of the galactic center

We consider the origin of the so-called S stars orbiting the supermassive black hole at the very center of the Galaxy. These are usually assumed to be massive main-sequence stars. We argue instead that they are the remnants of low-to-intermediate mass red giants which have been scattered on to near-radial orbits and tidally stripped as they approach the central black hole. Such stars retain only low-mass envelopes and thus have high effective temperatures. Our picture simultaneously explains why S stars have tightly-bound orbits, and the observed depletion of red giants in the very center of the Galaxy.Comment: 9 pages, 1 figure, ApJ Letters, in pres

Axion-like-particle decay in strong electromagnetic backgrounds

The decay of a massive pseudoscalar, scalar and U(1) boson into an electron-positron pair in the presence of strong electromagnetic backgrounds is calculated. Of particular interest is the constant-crossed-field limit, relevant for experiments that aim to measure high-energy axion-like-particle conversion into electron-positron pairs in a magnetic field. The total probability depends on the quantum nonlinearity parameter - a product of field and lightfront momentum invariants. Depending on the seed particle mass, different decay regimes are identified. In the below-threshold case, we find the probability depends on a non-perturbative tunnelling exponent depending on the quantum parameter and the particle mass. In the above-threshold case, we find that when the quantum parameter is varied linearly, the probability oscillates nonlinearly around the spontaneous decay probability. A strong-field limit is identified in which the threshold is found to disappear. In modelling the fall-off of a quasi-constant-crossed magnetic field, we calculate probabilities beyond the constant limit and investigate when the decay probability can be regarded as locally constant.Comment: 22 pages, 7 figure

Qubit Channels Can Require More Than Two Inputs to Achieve Capacity

We give examples of qubit channels that require three input states in order to achieve the Holevo capacity.Comment: RevTex, 5 page, 4 figures

Maximization of capacity and p-norms for some product channels

It is conjectured that the Holevo capacity of a product channel \Omega \otimes \Phi is achieved when product states are used as input. Amosov, Holevo and Werner have also conjectured that the maximal p-norm of a product channel is achieved with product input states. In this paper we establish both of these conjectures in the case that \Omega is arbitrary and \Phi is a CQ or QC channel (as defined by Holevo). We also establish the Amosov, Holevo and Werner conjecture when \Omega is arbitrary and either \Phi is a qubit channel and p=2, or \Phi is a unital qubit channel and p is integer. Our proofs involve a new conjecture for the norm of an output state of the half-noisy channel I \otimes \Phi, when \Phi is a qubit channel. We show that this conjecture in some cases also implies additivity of the Holevo capacity

Evidence for a planetary mass third body orbiting the binary star KIC 5095269

In this paper, we report the evidence for a planetary mass body orbiting the close binary star KIC 5095269. This detection arose from a search for eclipse timing variations among the more than 2,000 eclipsing binaries observed by Kepler. Light curve and periodic eclipse time variations have been analysed using Systemic and a custom Binary Eclipse Timings code based on the Transit Analysis Package which indicates a $7.70\pm0.08M_{Jup}$ object orbiting every $237.7\pm0.1d$ around a $1.2M_\odot$ primary and $0.51M_\odot$ secondary in an 18.6d orbit. A dynamical integration over $10^7$ years suggests a stable orbital configuration. Radial velocity observations are recommended to confirm the properties of the binary star components and the planetary mass of the companion.Comment: 8 pages, 7 figures, Accepted for publication in MNRA

The experiences of patients and carers in the daily management of care at the end of life

Background Home is the preferred location for most people with an advanced disease and at the end of life. A variety of care professionals work in community settings to provide support to this population. Patients and their spouses, who also care for them (spouse-carers), are rarely accompanied by these sources of support at all times, and have to manage independently between their contact with care professionals. Aim To explore how patients and spouse-carers manage their involvement with care professionals in the community setting. Method Interpretive phenomenology informs the design of the research, whereby 16 interviews were conducted with the patients and spouse-carers. Interviews were recorded and transcribed verbatim. Data were analysed using phenomenological techniques including template analysis. Findings Patients and spouse-carers were interdependent and both parties played a role in co-ordinating care and managing relationships with professional care providers. The patients and spouse-carers actively made choices about how to manage their situation, and develop and modify managing strategies based on their experiences. Conclusions When daily management is effective and care professionals acknowledge the dyadic nature of the patient and spouse-carer relationship, people have confidence in living with advanced disease