Radar signal categorization using a neural network

Neural networks were used to analyze a complex simulated radar environment which contains noisy radar pulses generated by many different emitters. The neural network used is an energy minimizing network (the BSB model) which forms energy minima - attractors in the network dynamical system - based on learned input data. The system first determines how many emitters are present (the deinterleaving problem). Pulses from individual simulated emitters give rise to separate stable attractors in the network. Once individual emitters are characterized, it is possible to make tentative identifications of them based on their observed parameters. As a test of this idea, a neural network was used to form a small data base that potentially could make emitter identifications

Stochastic modeling and financial viability of mollusk aquaculture

Compared to finfish and crustaceans, limited attention has been given to the economic modeling and production risk analysis of mollusk aquaculture. Given mollusk aquaculture's sensitivity to environmental factors, understanding production risk and its relationship to production technology and location is critical to firm viability. We modeled production as a function of random elements and performed stochastic risk analysis utilizing Monte Carlo simulation in conjunction with sensitivity analysis and scenario comparison. We applied these methods to compare different equipment systems and production strategies. This paper provides a framework for shellfish risk research that can be applied to various regions and species.publishedVersio

The Conductus of W1: an investigation into their history and rhythm

The manuscript ‘W1’, otherwise known as the St Andrews Music Book, contains 197 folios of music from the 13th century. This music was transmitted to St Andrews from the cathedral of Notre-Dame, Paris, which was the centre of European religious music making during the 12th and 13th centuries. The history of W1 is a fiercely debated topic, and this thesis will tackle some of the recent claims made regarding its dating, as well as dealing with some of the issues surrounding the conductus, a certain style of the Notre-Dame polyphonic chant repertoire, which inhabits a unique place in the repertoire of this time. Not evidently liturgical, but not secular, its role in the medieval church is highly debated, and its interpretation under the supposed ‘universal’ approach of Notre-Dame modal rhythm is ripe for enquiry. This rhythmical theory has been deduced from the interpretation of medieval theorists’ writings, however these writers were not clear and concise in terms of modern expectations. We find ourselves with a body of theoretical treatises written after several of the major manuscript sources were already created, posing a question for modern interpreters: should we apply these theoretical writings to a time before they were created, and were these practices in fact in use before the systemisation represented by the treatises occurred? Whilst much work has been done in applying modal rhythm to music which could predate the codification of modal rhythm, remarkably few editions present the music of this time without rhythmical biases. As this thesis will show, notions of rhythm were far more based around performative interpretations by the musicians, that than by abstract theoretical readings of notation. The rhythmically-undefined editions of this music that are found at the end of this thesis are an attempt to return this repertoire’s rhythm to its previous interpretational and performative aspect. This was found in the early years of Notre-Dame polyphony, where the notation was primarily meant only as a guide to the music’s shape. The intended use of these scores is a method more akin to a notational pitch guide than a fully metrically-conceived score, allowing for performances closer to the rhythmic freedom that the early Notre-Dame musicians had within this repertoire

Reading visually embodied meaning from the brain: Visually grounded computational models decode visual-object mental imagery induced by written text

Embodiment theory predicts that mental imagery of object words recruits neural circuits involved in object perception. The degree of visual imagery present in routine thought and how it is encoded in the brain is largely unknown. We test whether fMRI activity patterns elicited by participants reading objects' names include embodied visual-object representations, and whether we can decode the representations using novel computational image-based semantic models. We first apply the image models in conjunction with text-based semantic models to test predictions of visual-specificity of semantic representations in different brain regions. Representational similarity analysis confirms that fMRI structure within ventral-temporal and lateral-occipital regions correlates most strongly with the image models and conversely text models correlate better with posterior-parietal/lateral-temporal/inferior-frontal regions. We use an unsupervised decoding algorithm that exploits commonalities in representational similarity structure found within both image model and brain data sets to classify embodied visual representations with high accuracy (8/10) and then extend it to exploit model combinations to robustly decode different brain regions in parallel. By capturing latent visual-semantic structure our models provide a route into analyzing neural representations derived from past perceptual experience rather than stimulus-driven brain activity. Our results also verify the benefit of combining multimodal data to model human-like semantic representations

Genetic and hypoxic alterations of the microRNA-210-ISCU1/2 axis promote iron-sulfur deficiency and pulmonary hypertension

Iron–sulfur (Fe‐S) clusters are essential for mitochondrial metabolism, but their regulation in pulmonary hypertension (PH) remains enigmatic. We demonstrate that alterations of the miR‐210‐ISCU1/2 axis cause Fe‐S deficiencies in vivo and promote PH. In pulmonary vascular cells and particularly endothelium, hypoxic induction of miR‐210 and repression of the miR‐210 targets ISCU1/2 down‐regulated Fe‐S levels. In mouse and human vascular and endothelial tissue affected by PH, miR‐210 was elevated accompanied by decreased ISCU1/2 and Fe‐S integrity. In mice, miR‐210 repressed ISCU1/2 and promoted PH. Mice deficient in miR‐210, via genetic/pharmacologic means or via an endothelial‐specific manner, displayed increased ISCU1/2 and were resistant to Fe‐S‐dependent pathophenotypes and PH. Similar to hypoxia or miR‐210 overexpression, ISCU1/2 knockdown also promoted PH. Finally, cardiopulmonary exercise testing of a woman with homozygous ISCU mutations revealed exercise‐induced pulmonary vascular dysfunction. Thus, driven by acquired (hypoxia) or genetic causes, the miR‐210‐ISCU1/2 regulatory axis is a pathogenic lynchpin causing Fe‐S deficiency and PH. These findings carry broad translational implications for defining the metabolic origins of PH and potentially other metabolic diseases sharing similar underpinnings.National Institutes of Health (U.S.) (U54‐CA151884)National Institutes of Health (U.S.) (R01‐DE016516‐06)National Institutes of Health (U.S.) (EB000244

Quantification and qualification by in-situ FTIR of species formed on supported-cobalt catalysts during the Fischer-Tropsch reaction

We thanks the University of Aberdeen for a studentship (to A. McNab).Peer reviewedPostprintPostprin