A sub-determinant approach for pseudo-orbit expansions of spectral determinants in quantum maps and quantum graphs

We study implications of unitarity for pseudo-orbit expansions of the spectral determinants of quantum maps and quantum graphs. In particular, we advocate to group pseudo-orbits into sub-determinants. We show explicitly that the cancellation of long orbits is elegantly described on this level and that unitarity can be built in using a simple sub-determinant identity which has a non-trivial interpretation in terms of pseudo-orbits. This identity yields much more detailed relations between pseudo orbits of different length than known previously. We reformulate Newton identities and the spectral density in terms of sub-determinant expansions and point out the implications of the sub-determinant identity for these expressions. We analyse furthermore the effect of the identity on spectral correlation functions such as the auto-correlation and parametric cross correlation functions of the spectral determinant and the spectral form factor.Comment: 25 pages, one figur

Rhythm Quest: Creating a Music Video Game

This project was the creation of a music-centric video game named Rhythm Quest. Rhythm Quest is a combination of two very distinct video game genres, in a way that has not yet been done in the mainstream, particularly taking inspiration from the rhythm game Rhythm Heaven and the turn-based roleplaying-game (RPG) Paper Mario. It was a joint project between the computer science and music divisions, and involved the creation of all assets necessary to create a video game, including sprite creation, software development, writing, music, and sound effects. The game’s tutorial, as well as the battle system, is complete

The Secret Santa Problem Continues

We explore the Secret Santa gift exchange problem. A group of n people draws names at random, giving a gift to the person drawn. First, we examine the probabilities of gift exchanges under various scenarios when everyone draws names at once, similar to Montmort\u27s matching problem. We then consider the probabilities of certain gift exchanges when people take turns drawing names and develop a strategy to maximize the likelihood of receiving a gift from the most generous participant

Effect of plyometric training on swimming block start performance in adolescents

This study aimed to identify the effect of plyometric training (PT), when added to habitual training (HT) regimes, on swim start performance. After the completion of a baseline competitive swim start, 22 adolescent swimmers were randomly assigned to either a PT (n = 11, age: 13.1 ± 1.4 yr, mass: 50.6 ± 12.3 kg, stature: 162.9 ± 11.9 cm) or an HT group (n = 11, age: 12.6 ± 1.9 yr, mass: 43.3 ± 11.6 kg, stature: 157.6 ± 11.9 cm). Over an 8-week preseason period, the HT group continued with their normal training program, whereas the PT group added 2 additional 1-hour plyometric-specific sessions, incorporating prescribed exercises relating to the swimming block start (SBS). After completion of the training intervention, post-training swim start performance was reassessed. For both baseline and post-trials, swim performance was recorded using videography (50Hz Canon MVX460) in the sagital plane of motion. Through the use of Silicon Coach Pro analysis package, data revealed significantly greater change between baseline and post-trials for PT when compared with the HT group for swim performance time to 5.5 m (−0.59 s vs. −0.21 s; p < 0.01) and velocity of take-off to contact (0.19 ms−1 vs. −0.07 ms−1; p < 0.01). Considering the practical importance of a successful swim start to overall performance outcome, the current study has found that inclusion of suitable and safely implemented PT to adolescent performers, in addition to HT routines, can have a positive impact on swim start performance

Using questionnaires through an existing administrative system: a new approach to health interview surveys

This paper reviews recent developments in the field of health interview procedures, and their contribution to decentralized health planning. Their importance is reflected in the growing awareness that the perception of health problems by the beneficiaries is an important element in the success or failure of a primary health care (PHC) strategy for disease control and health improvement. The ‘indirect' health interview procedure represents a methodological evolution of the traditional interview approach, by the fact that questionnaires are not administered directly by the investigators or their field staff to the chosen key informants. They are distributed through an existing administrative system and self-administered by the recipients. This reduces the costs of such surveys, and allows large areas to be screened rapidly. The paper describes ongoing research designed to test this approach in seven African countries. Methodological problems and limitations, the most important of which is that it is not appropriate for individual diagnosis, are also discussed. This approach is best used as a screening strategy to identify high risk communities, on which health resources can then be concentrate

Generalized relation between electromechanical responses at fixed voltage and fixed electric field

We present a general relation between the electromechanical couplings of infinitesimal strain and electric field to arbitrary order, measured at fixed voltage and at fixed electric field. We show that the improper response at fixed field can be written as the strain derivative of the $n^{\text{th}}$ order susceptibility tensor, and the proper response at fixed voltage drop can be written as the response at fixed field plus corrections for dilations and 90$^{\circ}$ rotations induced by strain. Our theory correctly reproduces the proper piezoelectric response and we go beyond with the electrostrictive response. We present first-principles calculations of the improper electrostrictive response at fixed field, and illustrate how the correction is used to obtain the proper response at fixed voltage. This distinction is of high importance given the recent interest in giant electrostrictors exhibiting electromechanical responses as large as the piezoelectric ones.Comment: Accepted versio

Determination and optimization of mode matching into optical cavities by heterodyne detection

We report on a novel high-sensitivity method to characterize and improve mode matching into optical cavities. This method is based on heterodyne detection of cylindrical transverse cavity modes. A specially designed annular-segmented photodiode is used to measure the amplitude of nonresonant modes reflected by the cavity. Our measurements allow us to optimize cavity mode matching to nearly 99.98% and will play an important diagnostic role in gravitational-wave detectors

The importance of group factors in the delivery of group-based parenting programmes : a process evaluation of Mellow Babies

Author contributions JT: Conceptualization, Formal Analysis, Investigation, Methodology, Writing – original draft. PW: Conceptualization, Funding acquisition, Methodology, Supervision, Writing – review & editing. DW: Conceptualization, Methodology, Supervision, Writing – review & editing. LT: Conceptualization, Formal Analysis, Funding acquisition, Methodology, Supervision, Writing – review & editing.Peer reviewe