Nicolas Slonimsky's Role in the Musical Modernism of the Early Twentieth Century

The musical modernism movement of the early twentieth century began with much resistance, but blossomed into a period of inspired experimentation and development. Nicolas Slonimsky played an active role in the midst of this era. He was a composer, pianist, conductor, and writer. Examining the more personal aspects of his relationships with figures that were hallmark examples of this movement reveals Slonimsky's widespread influence. The most significant relationships that are focused on in this thesis include Charles Ives, Henry Cowell, Edgard Varèse, and Léon Theremin. To these men, Slonimsky offered great support, trusted advice, and recommendations to publishers, and he wrote beneficial articles regarding their music. He collaborated with them on their work, encouraged them, and pushed them to new heights. Nicolas Slonimsky was a champion of many musicians during his lifetime, promoting and supporting them, even at his own expense. Slonimsky made significant contributions to the developments of modern music during its growth in the twentieth century

Exploring the relative efficacy of motion artefact correction techniques for EEG data acquired during simultaneous fMRI

Simultaneous EEG-fMRI allows multi-parametric characterisation of brain function, in principle enabling a more complete understanding of brain responses; unfortunately the hostile MRI environment severely reduces EEG data quality. Simply eliminating data segments containing gross motion artefacts [MAs] (generated by movement of the EEG system and head in the MRI scanner’s static magnetic field) was previously believed sufficient. However recently the importance of removal of all MAs has been highlighted and new methods developed.A systematic comparison of the ability to remove MAs and retain underlying neuronal activity using different methods of MA detection and post-processing algorithms is needed to guide the neuroscience community. Using a head phantom, we recorded MAs while simultaneously monitoring the motion using three different approaches: Reference Layer Artefact Subtraction (RLAS), Moire Phase Tracker (MPT) markers, and Wire Loop Motion Sensors (WLMS). These EEG recordings were combined with EEG responses to simple visual tasks acquired on a subject outside the MRI environment. MAs were then corrected using the motion information collected with each of the methods combined with different analysis pipelines.All tested methods retained the neuronal signal. However, often the MA was not removed sufficiently to allow accurate detection of the underlying neuronal signal. We show that the MA is best corrected using the RLAS combined with post-processing using a multi-channel, recursive least squares (M-RLS) algorithm. This method needs to be developed further to enable practical utility; thus, WLMS combined with M-RLS currently provides the best compromise between EEG data quality and practicalities of motion detection

The effect of dewatering on the combustion behaviour of Loy Yang coal in a drop tube furnace

The Mechanical Thermal Expression (MTE) process is an efficient means of removing water from low-rank coal, however the effect of dewatering on the combustion properties of lignite is largely unknown. This work examines the burnout performance of both dewatered lignite and untreated lignite in a drop tube furnace. The results show that combustion of the MTE-processed lignite is approximately 20% slower under conditions relevant to pulverised-fuel flames. This is apparently due to the reduction in pore volume which occurs during coal dewatering by the MTE process.T. R. Ballantyne, P. J. Ashman and P. J. Mullinge

The agglomeration behaviour of lochiel coal during fluidised bed gasification

Fluidised bed gasification (FBG) is a promising process for utilising high-sodium and highsulphur coals, but agglomeration and defluidisation are potential problems. Experiments have been conducted to investigate these phenomena, to assist in elucidating the mechanisms at play and to develop operating solutions. It was found that agglomeration and defluidisation of Lochiel coal occur, within the 4-hour timeframe of these experiments, only when bed temperature exceeds 850°C and the air/fuel ratio is above 2.5. Agglomerates are composed mainly of silicate material, in combination with Na, Ca, Mg, Al and Fe in varying amounts. It is surmised that non-crystalline phases in agglomerates are sodium disilicate, with inclusions of Ca, Fe, Mg and Al that are expected to lower the mixture melting point, causing FBG operating problems when the total inorganic content of the bed rises above approximately 88wt% and with temperatures exceeding 850°C. It is expected that defluidisation can be avoided if operation is maintained outside of these conditions.D. P. McCullough, P. J. Mullinger and P. J. Ashma

Gasification of Victorian lignite in a laboratory scale fluidised bed gasifier

Posted with permission of the Organising Committee, 5th Asia Pacific Conference on Combustion, The University of Adelaide, ASPACC05.A 200-mm diameter, laboratory-scale atmospheric-pressure fluidised-bed reactor was designed and constructed by the Cooperative Research Centre (CRC) for Clean Power from Lignite. The purpose of this facility is to obt ain experimental data for the air/steam gasification of Australian lignite in order to validate the Centre’s mathematical model of a bubbling fluidised bed gasifier. An air-dried mixture of low-ash Victorian lignite has been used in air-steam and air-only gasification tests. The product syngas composition demonstrated successful gasification of coal with carbon monoxide and hydrogen concentrations each in the range 16-20 vol%. More carbon monoxide was measured in the syngas during coal gasification with air only. The gas composition of major species was observed to be relatively constant within the freeboard of the gasifier

Detecting gamma frequency neural activity using simultaneous multiband EEG-fMRI

The authors thank the Birmingham-Nottingham Strategic Collaboration Fund for funding this research.Synopsis (≤ 100 words): We establish a methodology for optimal combination of simultaneous EEG recording with sparse multiband fMRI that preserves high resolution, whole brain fMRI coverage with broad-band EEG signal measurement uncorrupted by MR gradient artefacts. We demonstrate the ability of this approach to record gamma frequency (>50Hz) EEG signals, that are usually obscured during continuous fMRI data acquisition. In a novel application to a motor task we observe a positive correlation between gamma and BOLD responses, supporting and extending previous findings concerning the coupling between neural and haemodynamic measures of brain activity.PostprintPostprintPeer reviewe

Reference layer artefact subtraction (RLAS): a novel method of minimizing EEG artefacts during simultaneous fMRI

Large artefacts compromise EEG data quality during simultaneous fMRI. These artefact voltages pose heavy demands on the bandwidth and dynamic range of EEG amplifiers and mean that even small fractional variations in the artefact voltages give rise to significant residual artefacts after average artefact subtraction. Any intrinsic reduction in the magnitude of the artefacts would be highly advantageous, allowing data with a higher bandwidth to be acquired without amplifier saturation, as well as reducing the residual artefacts that can easily swamp signals from brain activity measured using current methods. Since these problems currently limit the utility of simultaneous EEG–fMRI, new approaches for reducing the magnitude and variability of the artefacts are required. One such approach is the use of an EEG cap that incorporates electrodes embedded in a reference layer that has similar conductivity to tissue and is electrically isolated from the scalp. With this arrangement, the artefact voltages produced on the reference layer leads by time-varying field gradients, cardiac pulsation and subject movement are similar to those induced in the scalp leads, but neuronal signals are not detected in the reference layer. Taking the difference of the voltages in the reference and scalp channels will therefore reduce the artefacts, without affecting sensitivity to neuronal signals. Here, we test this approach by using a simple experimental realisation of the reference layer to investigate the artefacts induced on the leads attached to the reference layer and scalp and to evaluate the degree of artefact attenuation that can be achieved via reference layer artefact subtraction (RLAS). Through a series of experiments on phantoms and human subjects, we show that RLAS significantly reduces the gradient (GA), pulse (PA) and motion (MA) artefacts, while allowing accurate recording of neuronal signals. The results indicate that RLAS generally outperforms AAS when motion is present in the removal of the GA and PA, while the combination of AAS and RLAS always produces higher artefact attenuation than AAS. Additionally, we demonstrate that RLAS greatly attenuates the unpredictable and highly variable MAs that are very hard to remove using post-processing methods

Giving Voice to a Nation: Choral Music and Russian Identity in St. Petersburg, 1861-1913

This project examines the cultural practices surrounding choral singing and composition in St. Petersburg between 1861 and 1913, when boundaries of social classes realigned. Because people from a range of social classes experienced choral music, this repertoire and its practices played a vital role in the construction of identity during the second half of the nineteenth century. Despite the central socio-cultural role played by this repertoire, it has yet to be investigated as a source of cultural significance. This study contributes to three major areas of scholarship. First of all, advancing knowledge about lesser-known musical figures, unfamiliar choral repertoire, and the reception of choral music from late nineteenth-century Russia informs not only our portrayal of the choral scene in Russia, but also the international landscape of choral music. Secondly, by investigating musical networks thus far overlooked as participants in the construction of the musical scene in St. Petersburg, this document provides evidence about the people active in music making, both professional and amateur. Lastly, these observations expand on the current, still limited definition of Russian nationalism during the nineteenth century, as well as complement the importance of music as a social and ethnic identifier. Investigating choral institutions based in St. Petersburg between 1861 and 1913 as settings of identity negotiation reveals the complexity of defining Russianness within the fluctuating social classes and, likewise, how choral music shaped the emerging concepts of nation, state, and culture

Simultaneous EEG and fMRI at high fields

The work described in this thesis involves an investigation of the implementation and application of simultaneous EEG and fMRI. The two techniques arc complementary, with EEG providing excellent temporal resolution and fMRI having good spatial resolution. Combined EEG/fMRI thus forms a powerful tool for neuroscience studies. In initial work, methods for improving the removal of the gradient and pulse artefacts, which are induced in EEG traces recorded during concurrent MRI, have been developed. Subsequently, the effects of the EEG hardware on MR images were investigated. This involved acquiring a series of scans to identify the sources of B0- and B1 inhomogeneities and the extent to which these affect EPI data. The adverse effects on data quality of combining EEG and fMRI increase with field strength. Consequently, EEG-fMRI at 7T is particularly challenging, although a number of advantages make its implementation desirable. Safety tests were performed which showed the presence of the EEG system caused a negligible increase in RF heating effects during scanning at 7T. After elimination of a number of noise sources, the first simultaneous EEG-fMRI experiments at 7T using commercially available equipment were performed. Concurrent EEG/fMRI at 3T was then used to investigate the correlation between the BOLD (blood oxygenation level dependent) response measured during visual stimulation and both the preceding alpha power and the strength of the driven, electrical response. In considering the correlation of the range of variation of the alpha power and BOLD response, a trend emerged which allowed tentative conclusions to be drawn. Variation of the BOLD and driven response with the frequency of visual stimulation relative to a subject's individual alpha frequency (IAF) was also investigated. A significant increase in the driven response, accompanied by a decrease in the BOLD response was observed in visual cortex when it was driven at the IAF

Post-stimulus fMRI and EEG responses: evidence for a neuronal origin hypothesised to be inhibitory

Post-stimulus undershoots, negative responses following cessation of stimulation, are widely observed in functional magnetic resonance (fMRI) blood oxygenation level dependent (BOLD) data. However, the debate surrounding whether the origin of this response phase is neuronal or vascular, and whether it provides functionally relevant information, that is additional to what is contained in primary response, means that undershoots are widely overlooked. We simultaneously recorded electroencephalography (EEG), BOLD and cerebral blood-flow (CBF) [obtained from arterial spin labelled (ASL) fMRI] fMRI responses to hemifield checkerboard stimulation to test the potential neural origin of the fMRI post-stimulus undershoot. The post-stimulus BOLD and CBF signal amplitudes in both contralateral and ipsilateral visual cortex depended on the post-stimulus power of the 8-13 Hz (alpha) EEG neuronal activity, such that trials with highest EEG power showed largest fMRI undershoots in contralateral visual cortex. This correlation in post-stimulus EEG-fMRI responses was not predicted by the primary response amplitude. In the contralateral visual cortex we observed a decrease in both cerebral rate of oxygen metabolism (CMRO2) and CBF during the post-stimulus phase. In addition, the coupling ratio (n) between CMRO2 and CBF was significantly lower during the positive contralateral primary response phase compared with the post-stimulus phase and we propose that this reflects an altered balance of excitatory and inhibitory neuronal activity. Together our data provide strong evidence that the post-stimulus phase of the BOLD response has a neural origin which reflects, at least partially, an uncoupling of the neuronal responses driving the primary and post-stimulus responses, explaining the uncoupling of the signals measured in the two response phases. We suggest our results are consistent with inhibitory processes driving the post-stimulus EEG and fMRI responses. We therefore propose that new methods are required to model the post-stimulus and primary responses independently, enabling separate investigation of response phases in cognitive function and neurological disease