The generation and damping of propagating MHD kink waves in the solar atmosphere

The source of the non-thermal energy required for the heating of the upper solar atmosphere to temperatures in excess of a million degrees and the acceleration of the solar wind to hundreds of kilometers per second is still unclear. One such mechanism for providing the required energy flux is incompressible torsional Alfven and kink magnetohydrodynamic (MHD) waves, which are magnetically dominated waves supported by the Sun's pervasive and complex magnetic field. In particular, propagating MHD kink waves have recently been observed to be ubiquitous throughout the solar atmosphere, but, until now, critical details of the transport of the kink wave energy throughout the Sun's atmosphere were lacking. Here, the ubiquity of the waves is exploited for statistical studies in the highly dynamic solar chromosphere. This large-scale investigation allows for the determination of the chromospheric kink wave velocity power spectra, a missing link necessary for determining the energy transport between the photosphere and corona. Crucially, the power spectra contain evidence for horizontal photospheric motions being an important mechanism for kink wave generation in the quiescent Sun. In addition, a comparison with measured coronal power spectra is provided for the first time, revealing frequency-dependent transmission profiles, suggesting that there is enhanced damping of kink waves in the lower corona

Baptismal exegesis in abator's historia apostolica

The aim of this thesis is to examine the Historla Apostolica (AD 544) not as an example of 'biblical epic' nor as a literary paraphrase but as a commentary on The Acts of the Apostles, and in particular to signal Arator's concern to explain the text in terms of its baptismal significance. The opening chapter reviews previous approaches to the H.A. and is followed by a survey of Arator's interpretation and interpolation of baptismal material, showing both how those episodes In Acts which deal specifically with baptism are given extended exegetical attention, and how baptismal significance is frequently divined in passages which have no obvious baptismal connection. The central chapters examine in detail the episodes of the poem which are of most baptismal importance. Two deal with Arator's exegesis of explicitly baptismal situations: Simon Magus' failure to receive the Spirit is presented as being prefigured in the failure of the raven to return to the ark, a parallel also drawn by Augustine; the Ethiopian eunuch is presented in accordance with the Ethiopian’ exegesis first formulated by Orlgen. Four more chapters examine episodes which Arator deems of implicit baptismal significance: the ascension is interpreted In terms of the baptism and ascent' of the individual; the healing of the paralytic Is explained as the baptismal healing of the wounds of circumcision; Paul's speech at Antloch becomes an exposition of the typological significance of the crossing of the Red Sea; the name Aquila prompts a digression on the baptismal Implications of the rejuvenation of the eagle. The aim is not to discover indisputable sources for all of Arator's ideas, but rather to place the H.A. in its exegetical context, and to trace the development and popularity of baptismal symbolism in the first six centuries AD

A statistical study of transverse oscillations in a quiescent prominence

The launch of the Hinode satellite has allowed for seeing-free observations at high-resolution and high-cadence making it well suited to study the dynamics of quiescent prominences. In recent years it has become clear that quiescent prominences support small-amplitude transverse oscillations, however, sample sizes are usually too small for general conclusions to be drawn. We remedy this by providing a statistical study of transverse oscillations in vertical prominence threads. Over a 4 hr period of observations it was possible to measure the properties of 3436 waves, finding periods from 50 to 6000 s with typical velocity amplitudes ranging between 0.2 and 23 km s–1. The large number of observed waves allows the determination of the frequency dependence of the wave properties and derivation of the velocity power spectrum for the transverse waves. For frequencies less than 7 mHz, the frequency dependence of the velocity power is consistent with the velocity power spectra generated from observations of the horizontal motions of magnetic elements in the photosphere, suggesting that the prominence transverse waves are driven by photospheric motions. However, at higher frequencies the two distributions significantly diverge, with relatively more power found at higher frequencies in the prominence oscillations. These results highlight that waves over a large frequency range are ubiquitous in prominences, and that a significant amount of the wave energy is found at higher frequency

Providing weight management via the workplace

Purpose Assess the feasibility and benefits of providing weight management support via the workplace. Design Quasi-experimental design using non-random assignment to a 12 week Slimming World (SW) weight management programme, either within the workplace or at a regular community group. Weight was recorded weekly and a 39-item questionnaire focussed on mental and emotional health, self-esteem, dietary habits and physical activity habits administered at baseline, 12 weeks, 6 and 12 months. Findings 243 participants enrolled (workplace n=129, community n=114) with 138 completers (defined as those weighing-in at baseline and attending at least once within the last 4 weeks; workplace n=76, community n=62. Completers reported a mean weight change of -4.9kg ± 3.4 or -5.7% ± 3.8. Mental and emotional health scores increased (P<0.05) from baseline to 12 weeks. Self-worth scores increased (P<0.05) from baseline to 12 weeks, 6 months and 12 months. Healthy dietary habit scores increased and unhealthy dietary habit scores decreased (P<0.05) from baseline to 12 weeks, 6 months and 12 months. Healthy physical activity habit scores improved (P<0.05) from baseline to 12 weeks and 6 months. There were no significant differences between groups. Research limitations Participant demographic was predominantly female (94%) aged 42.3 years, with only 13 men participating. Practical implications The results support the use of a 12 week SW weight management programme as a credible option for employers wanting to support employees to achieve weight loss and improve psycho-social health outcomes which could lead to improvements in quality of life and work performance Originality/value Provides evidence for the delivery of weight management support via the workplace