Methodological developments in data fusion for lake water reflectance from satellite sensors

Fusing satellite-sensed reflectance data from different sources is of interest to monitor lake water quality, and the satellite sensors have possibly different spatial, temporal and spectral supports. The nonparametric statistical downscaling (NSD) model is an existing state-of-the-art fusion model which can account for a change of spatial and temporal support between two remote sensors [Wilkie et al., 2019]. However, the NSD model is computationally demanding for large datasets and does not allow multivariate responses with an additional spectral dimension. Thus, the aim of this thesis is to improve the computational efficiency of the NSD model and then extend this model to provide an approach that is suitable for a multivariate response to enable the fuse of reflectance data with different spectral and temporal supports from two sensors. The NSD model assumes that the discrete data at each location within a lake from each data source are observations of smooth functions over time and that the coefficients of these smooth functions are modelled as spatially correlated via a covariance matrix. In this thesis, a novel approach proposes using a Gaussian predictive process to approximate the spatial varying coefficients in the NSD model, which requires the inversion of a matrix with smaller dimensions in the Gibbs sampling process and hence reduces the computational time for the parameter estimation. The predictive performance and computational efficiency of the proposed nonparametric statistical downscaling model with Gaussian predictive process (NSD-GPP) are compared to the NSD model through simulation and using satellite reflectance data from Lake Garda. It was found that the NSD-GPP model achieves a similar predictive performance as the NSD model using less computational time. To enable data fusion from the two sensors with a multivariate wavelength dimension, a novel method using the two-dimensional B-spline basis functions was developed where the basis functions were used to represent the reflectance over both time and wavelength at each location, and a different precision parameter was used for each wavelength. Lake Garda is used as an example of interest here, and methods are general for any lake of interest in principle. Overall, it is found that the proposed multivariate NSD-GPP model could be used to make predictions for the unobserved wavelengths and time points within the observed range. It may be beneficial to provide reflectance data at higher temporal and wavelength frequencies, and this model could in principle be extended to consider similar challenges in space

Using external stimuli to design responsive supramolecular systems with predictable properties

Supramolecular gels formed by the self-assembly of peptide-based LMWG are a class of soft materials that have attracted significant interest for a vast range of applications. Due to the non-covalent nature of the interactions underpinning the gel networks, these materials can exhibit stimuli-responsive behaviour to external triggers. By introducing this aspect in their design, a wide variety of new materials can be accessed with pre-determined properties with a high level of temporal and spatial control. In this Thesis, we describe how to harness external stimuli to induce predictable and reversible changes in supramolecular systems, achieving materials with desirable properties for different potential applications. First, we show a dipeptide-based LMWG system undergoing pre-programmable gel-to-sol-to-gel transitions obtained by means of a pH cycle. We investigate the effect of mechanical stimuli applied during rheological measurements on the properties of these evolving materials, highlighting how varying parameters of strain and frequency can be used to obtain a wide range of gels with different properties starting from the same material. Building on these results, we then design a new system undergoing gel-to-sol-to-gel transitions capable of aligning under unidirectional shear in the solution phase. Using a novel combined technique of rheology, polarised light imaging and SAXS, we show the potential of this system to prepare gels with aligned domains using mechanical stimuli. We further highlight the versatility of this approach by inducing alignment using a magnetic field. We then describe the use of a non-invasive light trigger to design a multicomponent system based on a LMWG and a photoacid molecule capable of switching pH under irradiation. We show how this approach yields a light-responsive system that reproducibly changes viscosity under irradiation. Using a variety of combined in situ techniques (rheology, NMR and SAXS), we elucidate the way these changes occur on a variety of length scales. We finally show how this stimuli-responsive system can be used to stop flow at specific locations using light and discuss potential applications. Finally, we focus on the design of peptide-based gels for applications in drug storage and release by taking advantage of their unique response to mechanical stimulus. By using rheology, SAXS and release tests we show how gel mechanical properties, network morphology and choice of trigger can affect the ability of these systems to store and successfully release a cargo molecule. Based on this, we then establish a novel method to release biologics using a simple mechanical stimulus. Lastly, we test the stability of these systems under various real-world conditions for future applications in drug delivery

Musical reuse in the Notre Dame repertory: historiography and new computational directions

Of the many questions that we may wish to ask of the repertory of twelfth- and thirteenth-century music commonly known as Notre Dame polyphony, issues surrounding musical reuse and borrowing suffuse nearly every aspect. Questions of chronologies, locations, composers, purposes, processes, orality, performance, transmission, as well as all manner of other unknowns in the repertory, can be well argued and evidenced by the presence (or not) of musical reuse and borrowing. The freedom with which fragments, and sometimes even entire settings of music, circulated throughout thirteenth-century musical culture appears to defy our typical notions of chronology, composition, and even deterministic process. Musicological scholarship from the 19th century to the present day places the clausula at the centre of this whirlwind of borrowings and musical–textual allusions, the enigmatic form by which the contemporary music theorist Anonymous IV contended that the modernisation of the repertory had taken place. Modern study has identified many so-called substitute clausulae in the fragments of polyphonic settings transmitted in certain fascicles of the central manuscript sources, and it is largely by these substitute clausulae that the later genre of the motet was created. However, relating substitute clausulae back to their source organa and forward to motet has proven difficult, due to the music of the Notre Dame repertory refusing to yield in all cases to the simple and causal chronology that this implies. More recent work in particular is considering how musical reuse in the Notre Dame repertory may be conceived beyond the static and one-to-one substitutions of clausulae. These are often thought of as different phenomena: processes such as indirect concordances and melodic formulae are considered entirely separate from clausula substitution. At the same time, musical reuse has been treated with a particularly restrictive historical focus, and the clausula has been given centre stage as the main vehicle for musical reuse, catalogued and analysed as tightly interwoven with motet, and minimising other forms of musical reuse in the process. However, when we try to uncover what authors actually mean when they are discussing aspects of musical reuse such as the clausula, we find their definitions inexact and conflicting. This dissertation therefore tackles the issue of musical reuse in the Notre Dame repertory afresh, placing the notation of the manuscript sources at the centre of the study and considering how the broader issue of reuse can be studied holistically in the twenty-first century, beyond limiting categorical descriptors and arbitrary criteria. By creating new methodological tools around the complex and ambiguous notation of thirteenth century polyphony, I investigate how new digital methods can be harnessed to extract patterns of musical reuse further than via simple verbatim substitution. The operation and interpretation of thirteenth century notation poses new and unique challenges for representation in the computer which have not yet been satisfactorily solved. I therefore develop novel encoding, optical music recognition, and analysis methodologies to approach these problems from new angles, centred around a specially created online database for the browsing, editing, and analysis of thirteenth-century polyphony. Using the novel tools that I present as part of this study, I extract new and previously undetected patterns of musical reuse within the repertory that fall outside of our typical perceptions of independent reuse phenomena, pointing the way towards a wider and more nuanced concept of musical reuse as a dispersed network of common musical culture in the twelfth and thirteenth centuries. This is a concept that does not necessarily rely on causality or linear process, and hence may resolve the underlying issues (chronology, composition, and deterministic process) that musical reuse represents

Divine glorification and human happiness in Christian teleology

Introduction: pages 4-8

Sampling designs for the spatiotemporal modelling of groundwater quality monitoring data

Applying appropriate sampling designs in the long-term monitoring of groundwater quality networks is crucial in ensuring that accurate inferences are made about the spatio-temporal distribution of the concentrations of constituents of potential concern (CoPC). Furthermore, the sampling of groundwater monitoring wells and the subsequent analysis of samples induces costs, safety hazards and unintended environmental consequences. Therefore, an optimal sampling design should aim to minimise sample sizes, whilst maximising the value of the information obtained. The problem of finding optimal locations for wells to extend or establish a network has received a lot of attention in the literature. In contrast, fewer approaches have been proposed for optimal sample selection within existing networks, especially in a spatio-temporal context, and the application of these approaches in practice is limited. Current sampling practices often rely on expert judgment and prescriptions by regulatory bodies, which results in datasets that are not well-suited for statistical analysis. Despite its statistical advantages such as generalisability and reducing bias, probability sampling is seldom applied in long-term groundwater quality monitoring. The primary aims of this thesis were to assess common characteristics of long-term groundwater quality data and the use of spatio-temporal models, explore the optimisation of sampling designs through reducing network size, and propose approaches based on probability sampling to support the spatio-temporal modelling of CoPC concentrations. To compare different approaches to the spatio-temporal modelling of CoPC concentrations via generalised additive models (GAMs) and to assess common characteristics of long-term ground water quality monitoring data, a comparative study is presented. The study uses synthetic and case study data to evaluate differences in estimating spatio-temporal CoPC concentration surfaces via GAMs with separate and joint smooth terms for space and time. The results highlight the importance of model specification and sampling patterns for obtaining reliable estimates of CoPC concentrations. In practice, the identification of wells that provide redundant information with respect to the estimation of CoPC concentrations can often be omitted from sampling designs to reduce strain on resources, whilst ensuring that conclusions about spatial and temporal trends are not affected. The demand for a tool to facilitate well redundancy analysis was identified through feedback shared by the users of the groundwater quality modelling software GWSDAT1. In this thesis, a computationally efficient, data-driven approach is proposed for ranking monitoring wells based on their influence on spatio-temporal CoPC concentration models. The approach is based on influential observation diagnostics and is shown to provide rankings similar to a computationally more demanding, cross-validation (CV) based method, through a case study and a simulation study using synthetic groundwater quality data. The approach has also been implemented in GWSDAT. Thus, omitting redundant wells can be an effective approach for the optimisation of groundwater monitoring networks, but it does not make suggestions on specific sample selection. The generation of spatio-temporal sampling designs, optimised to support the estimation of CoPC concentrations, can help further improve the sustainability of long-term monitoring. In this thesis, it is shown through a literature review that probability sampling designs that aim to draw a spatially and temporally balanced, i.e. evenly spread samples, result in a more precise estimation of CoPC concentration surfaces than simple random designs. Furthermore, it is proposed that by tuning the inclusion probabilities of sample units in balanced designs based on historic data to track the spatial evolution of CoPC concentrations through time, a more precise characterisation of the CoPC plume can be achieved. An original, data-driven methodology is developed for tuning sample inclusion probabilities to be proportional to future predicted distances between the wells and the boundaries of the CoPC plume. Higher probability for selection is given to wells that are predicted to be closer to the plume at a given time. The proposed methodology is shown to provide advantages in characterising plumes given a sufficiently large sample size, using a case study and a simulation study of synthetic CoPC concentration data. An approach is also proposed for the application of spatio-temporally balanced sampling designs in evaluating the sufficiency of historic sampling intensity. By comparing the CoPC concentration estimates of models using all available historic data and increasingly smaller subsamples selected via balanced designs, it can be assessed whether the monitoring network has been over or undersampled. This information can then be used to adjust future sampling intensity accordingly. Finally, consideration is given to the trade-off between high spatial and temporal sampling intensity, given a fixed sample size and monitoring period. In practice, it can be logistically advantageous to perform sampling less frequently, but obtain more samples during each campaign. This results in a spatially high, but temporally low resolution data set. Through a simulation study of synthetic CoPC plume data, it is shown that high spatial resolution data is advantageous when estimating the overall concentration surface, but high temporal resolution data can provide benefits in estimating plume characteristics

“Out of sight, out of mind”: International labour migration and fair employment in the Scottish fishing industry

This thesis explores regulative, economic and social dynamics surrounding the employment of migrant fishers working in the Scottish fishing industry. It draws on a qualitative empirical study, comprising primarily of semi-structured interviews (n=37) with fishers, recruiters, representatives of fisheries associations and relevant labour and fisheries NGOs, members of fishing communities, and (former) officials working in related fields. Conceptually, the research is situated between historical and new materialist approaches to geographies of the sea which capture how the work of (migrant) fishers is materially, economically and socially characterized by themes of precarity and instability. The thesis draws on and contributes to literatures on labour geographies (Anderson 2010, Lewis et al, 2015), migration and bordering (El-Enany, 2020), maritime geographies (Steinberg and Peters, 2015; 2019; Campling and Colás, 2021), and emerging literatures on blue justice (Mills, 2015; Bennet et al, 2020). Through three empirical chapters this thesis discusses policies, enforcements and ideals related to the employment of migrant fishers working in Scotland. Characterizing the industry’s reliance on the oversea workforce as a spatial fix (Harvey, 1982), it analyses the UK immigration regime following the vote for Brexit in relation to the mode of employment in Scottish marine fisheries, arguing that the frequently changing immigration regulations increase precarity among domestic fishers and hyper-precarity among migrant fishers. It then problematises the process of enforcement of labour and immigration regulations at sea, arguing that the conceptualisation of oceanic spaces – in our geographical imaginations, in policy and discursive abstractions, and in individual and collective lived realities – as an unstable and ever-changing place works to both enable and obfuscate the precarious labour practices that take place at sea. It subsequently analyses how practices of regulation and enforcement are negotiated through individual and collective moral geographies. Finally, it calls for a multiscalar approach, drawing on Massey (2004) to argue that the scales of justice in fisheries are inter-connected; and showing that what happens within the porous boundaries of Scottish fisheries is both a product and a part of the practices reproduced in global fisheries

A critical metaphysics of economy (oikonomia): dramatizing G. Deleuze’s reading of Plato, Stoics, Spinoza and Byzantines

Abstract not currently available

Anglo American relations

No abstract available

Communication-efficient decentralized federated learning

Abstract not currently available

Magnetoelectric antennas for wireless power and data transfer at microwave frequencies in medical devices

Abstract not currently available