329 research outputs found
The People's Poet transformed: Geoff Goodfellow in conversation with Garry Costello
No full textAn Author event presented by The Friends of the University of Adelaide Library and held in the Ira Raymond Room, Barr Smith Library, 16 May 2019Legendary performance poet and short prose writer Geoff Goodfellow has performed his poetry at schools, jails, colleges, universities, construction sites, factories, rock concerts and literary festivals, across Australia and in Canada, the United States, Cuba, China, Europe and the United Kingdom
Modelling and finite time stability analysis of psoriasis pathogenesis
No full textA new systems model of psoriasis is presented and analysed from the perspective of control theory.
Cytokines are treated as actuators to the plant model that govern the cell population under the reasonable
assumption that cytokine dynamics are faster than the cell population dynamics. The analysis of various
equilibria is undertaken based on singular perturbation theory. Finite time stability and stabilisation
has been studied in various engineering applications where the principal paradigm uses non-Lipschitz
functions of the states. A comprehensive study of the finite time stability properties of the proposed
psoriasis dynamics is carried out. It is demonstrated that the dynamics are finite time convergent to
certain equilibrium points rather than asymptotically or exponentially convergent. This feature of finite
time convergence motivates the development of a modified version of the Michaelis-Menten function,
frequently used in biology. This framework is used to model cytokines as fast finite time actuators.This work was supported by EPSRC via research grants EP/J018295/1 and EP/J018392/1. Marc
Goodfellow gratefully acknowledges the financial support of the EPSRC via grant EP/N014391/1
The contribution of Marc Goodfellow was generously supported by a Wellcome Trust Institutional
Strategic Support Award (WT105618MA)
Past and future impact of glacial erosion in Forsmark and Uppland : final report
No full textThe following report constitutes a final report of a comprehensive study on denudation and glacial
erosion conducted at Forsmark and in the surrounding Uppland province, Sweden, between 2015 and
2019. The aim was to quantify the amount of past denudation at the Forsmark site and the broader
Uppland region, with special focus on glacial erosion, by employing a range of methodologies. The
methods included geomorphological mapping and analysis of the bedrock surface and Quaternary
deposits, cosmogenic exposure dating, bedrock fracture mapping, and shallow bedrock stress modelling.
The results were also used together with results from a long-term climate modelling study to
quantify the potential amount of glacial erosion at Forsmark over the coming one million years.
The study was initiated by Jens-Ove Näslund (SKB) and it was jointly designed by Jens-Ove Näslund,
Adrian Hall (Stockholm University), Karin Ebert (Södertörn University), Bradley Goodfellow
(Stockholm University, SGU), Clas Hättestrand (Stockholm University), Jakob Heyman (University
of Gothenburg) and Arjen Stroeven (Stockholm University). Adrian Hall coordinated the scientific
work within the study, and also conducted the studies on long-term burial and erosion history
(Chapter 2) and glacial erosion (Chapter 4). Karin Ebert developed the digital elevation models of
the unconformity and derived the glacial erosion estimates derived from summit erosion surfaces.
Bradley Goodfellow contributed across the project and conducted the study of topographic stress
perturbation, with mathematical modelling by Seulgi Moon (University of California, Los Angeles)
(Chapter 3). Clas Hättestrand developed geomorphological maps of the unconformity and of glacial
bedforms. Maarten Krabbendam (British Geological Survey) contributed to Chapter 2 on the longterm
burial and erosion history and to Chapter 4 on glacial erosion and mapped landforms associated
with glacial ripping in Uppland. Sample site selection and cosmogenic nuclide sample collection was
carried out by Jakob Heyman, Bradley Goodfellow, Arjen Stroeven, Marc Caffee and Adrian Hall.
Jakob Heyman conducted the modelling of cosmogenic nuclide erosion and burial histories. Bradley
Goodfellow was involved in cosmogenic nuclide sample preparation at Purdue University. Reporting
and interpretation of cosmogenic nuclide results in Chapter 5 was done by Jakob Heyman, Arjen
Stroeven and Bradley Goodfellow. All authors contributed to the final revision of the report.
The study includes several additional important contributions. Marc Caffee (Purdue University) was
responsible for all cosmogenic isotope laboratory analyses and guided and participated in the discussions
of interpretation of results (Chapter 5). Stephen Martel (University of Hawaii) and Taylor
Perron (Massachusetts Institute of Technology) were involved in the fracture mapping and modelling
(Chapter 3). Mikis van Boeckel (Stockholm University) produced many of the figures in the report
from digital elevation model data from the Swedish mapping, cadastral and land registration authority
(Lantmäteriet) and SGU.
In connection to the present study, two additional studies have been performed employing similar
methods (e.g. geomorphological analysis and cosmogenic exposure dating) for studying the sub-
Cambrian unconformity in the Trollhättan area in south-western Sweden. The two associated studies
will be published in separate reports (Goodfellow et al. 2019, Hall et al. 2019a).
The results will be used, together with other published scientific information, for constructing future
scenarios of climate and climate-related processes in SKB’s work on assessing long-term safety of
nuclear waste repositories in Sweden. The safety assessments performed for the planned repository
for spent nuclear fuel in Forsmark, Sweden, cover a total time span of one million years. Since this
time span covers the timescales relevant for glacial cycles, the effect of future glacial erosion needs
to be analysed in the safety assessments. In this context, the present study provides important results
on the potential amount of glacial erosion that may be expected in the topographical, geological, and
glaciological setting of the Forsmark site. A separate study models changes in climate over the next
1 million years and has been published ahead of this report (Lord et al. 2019)
Knowledge co-production and behavioural change: collaborative approaches for promoting sustainable mobility
No full textThis is the author accepted manuscript of a chapter published by Goodfellow Publishers in Low Carbon Mobility Transitions, edited by Debbie Hopkins, James Higham.The final version is available from Goodfellow Publishers via the link in this record.Published 2016. ISBN: 978-1-910158-64-7 hbk; 978-1-910158-65-4 eBook.Behavioural change has become regarded as a key tool for policy makers to promote behavioural change that can reduce carbon emissions from personal travel. Recommended changes in travel behaviours range from travel mode shifts (from car to bicycle and walking), through amending established habits (car sharing rather than sole car occupancy) to more radical alternatives, such as reducing short haul flying and replacing such flights with rail travel. Yet academic research has suggested that promoting low carbon travel behaviours, in particular those associated with leisure and tourism practices, is particularly challenging because of the highly valued and conspicuous nature of the consumption involved. Accordingly, traditional top-down approaches to developing behavioural change campaigns have largely been ineffectual in this field and this chapter explores innovative ways to understand and develop behavioural change campaigns that are driven from the bottom upwards. In doing so, we draw on emergent literature from management studies and social marketing to explore how ideas of service dominant logic can be used to engage consumers in developing each stage of a behavioural change campaign. Using data and insights from research conducted in the south-east of the UK, we outline and evaluate the process for co-producing knowledge about low carbon travel and climate change. By focusing on two key segments of traditionally frequent flyers (young professionals and ‘empty nesters’) we illustrate how behavioural change campaign creation can be an engaging, lively and productive process of knowledge and experience sharing. The chapter ends by considering the role that co-production and co-creation can have in developing strategies for low carbon mobility and, more broadly, the ways in which publics understand and react to anthropogenic climate change
Self-organised transients in a neural mass model of epileptogenic tissue dynamics
No full textStimulation of human epileptic tissue can induce rhythmic, self-terminating responses on the EEG or ECoG. These responses play a potentially important role in localising tissue involved in the generation of seizure activity, yet the underlying mechanisms are unknown. However, in vitro evidence suggests that self-terminating oscillations in nervous tissue are underpinned by non-trivial spatio-temporal dynamics in an excitable medium. In this study, we investigate this hypothesis in spatial extensions to a neural mass model for epileptiform dynamics. We demonstrate that spatial extensions to this model in one and two dimensions display propagating travelling waves but also more complex transient dynamics in response to local perturbations. The neural mass formulation with local excitatory and inhibitory circuits, allows the direct incorporation of spatially distributed, functional heterogeneities into the model. We show that such heterogeneities can lead to prolonged reverberating responses to a single pulse perturbation, depending upon the location at which the stimulus is delivered. This leads to the hypothesis that prolonged rhythmic responses to local stimulation in epileptogenic tissue result from repeated self-excitation of regions of tissue with diminished inhibitory capabilities. Combined with previous models of the dynamics of focal seizures this macroscopic framework is a first step towards an explicit spatial formulation of the concept of the epileptogenic zone. Ultimately, an improved understanding of the pathophysiologic mechanisms of the epileptogenic zone will help to improve diagnostic and therapeutic measures for treating epilepsy
A computational biomarker of idiopathic generalized epilepsy from resting state EEG
No full textThis is the author accepted manuscript. This is an open access article. The final version is available from Wiley via the DOI in this record.Epilepsy is one of the commonest serious neurological conditions. It is characterized by the tendency to have recurrent seizures, which arise against a backdrop of apparently normal brain activity. At present, clinical diagnosis relies on: (i) case history, which can be unreliable; (ii) observing transient abnormal activity during electroencephalography (EEG), which may not be present during clinical evaluation; (iii) if diagnostic uncertainty occurs, undertaking prolonged monitoring in an attempt to observe EEG abnormalities, which is costly. Herein, we describe the discovery and validation of an epilepsy biomarker based on computational analysis of a short segment of resting-state (inter-ictal) EEG. Our method utilizes a computer model of dynamic networks, where the network is inferred from the extent of synchrony between EEG channels (functional networks) and the normalized power spectrum of the clinical data. We optimize model parameters using a leave-one-out classification on a dataset comprising 30 people with idiopathic generalized epilepsy (IGE) and 38 normal controls. Applying this scheme to all 68 subjects we find 100% specificity at 56.7% sensitivity, and 100% sensitivity at 65.8% specificity. We believe this biomarker could readily provide additional support to the diagnostic processHelmut Schmidt, Mark P. Richardson and John R. Terry received financial support from Epilepsy
Research UK (via Grant A1002). Marc Goodfellow, Mark P. Richardson and John R. Terry
received financial support from the Medical Research Council (via Programme Grant
MR/K013998/1) and the EPSRC (via Centre Grant EP/N014391/1). John R. Terry further
acknowledges the generous support of the Wellcome Trust Institutional Strategic Support Award
(WT105618MA). Mark P. Richardson is part-funded by the National Institute of Health Research
(NIHR) Biomedical Research Centre at the South London and Maudsley NHS Foundation Trust
Evaluating resective surgery targets in epilepsy patients: a comparison of quantitative EEG methods.
No full textThis is the author accepted manuscript. The final version is available from Elsevier via the DOI in this record.BACKGROUND: Quantitative analysis of intracranial EEG is a promising tool to assist clinicians in the planning of resective brain surgery in patients suffering from pharmacoresistant epilepsies. Quantifying the accuracy of such tools, however, is nontrivial as a ground truth to verify predictions about hypothetical resections is missing. NEW METHOD: As one possibility to address this, we use customized hypotheses tests to examine the agreement of the methods on a common set of patients. One method uses machine learning techniques to enable the predictive modeling of EEG time series. The other estimates nonlinear interrelation between EEG channels. Both methods were independently shown to distinguish patients with excellent post-surgical outcome (Engel class I) from those without improvement (Engel class IV) when assessing the electrodes associated with the tissue that was actually resected during brain surgery. Using the AND and OR conjunction of both methods we evaluate the performance gain that can be expected when combining them. RESULTS: Both methods' assessments correlate strongly positively with the similarity between a hypothetical resection and the corresponding actual resection in class I patients. Moreover, the Spearman rank correlation between the methods' patient rankings is significantly positive. COMPARISON WITH EXISTING METHOD(S): To our best knowledge, this is the first study comparing surgery target assessments from fundamentally differing techniques. CONCLUSIONS: Although conceptually completely independent, there is a relation between the predictions obtained from both methods. Their broad consensus supports their application in clinical practice to provide physicians additional information in the process of presurgical evaluation.This work was supported by the Swiss National Science Foundation (SNF) (Project No: SNF 32003B
155950). M.G. gratefully acknowledges the financial support of the EPSRC via grant EP/N014391/1. The contribution of M.G. was generously supported by a Wellcome Trust Institutional Strategic Support Award (WT105618MA)
Intermittent spike-wave dynamics in a heterogeneous, spatially extended neural mass model
No full textGeneralised epileptic seizures are frequently accompanied by sudden, reversible transitions from low amplitude, irregular background activity to high amplitude, regular spike-wave discharges (SWD) in the EEG. The underlying mechanisms responsible for SWD generation and for the apparently spontaneous transitions to SWD and back again are still not fully understood. Specifically, the role of spatial cortico-cortical interactions in ictogenesis is not well studied. We present a macroscopic, neural mass model of a cortical column which includes two distinct time scales of inhibition. This model can produce both an oscillatory background and a pathological SWD rhythm. We demonstrate that coupling two of these cortical columns can lead to a bistability between out-of-phase, low amplitude background dynamics and in-phase, high amplitude SWD activity. Stimuli can cause state-dependent transitions from background into SWD. In an extended local area of cortex, spatial heterogeneities in a model parameter can lead to spontaneous reversible transitions from a desynchronised background to synchronous SWD due to intermittency. The deterministic model is therefore capable of producing absence seizure-like events without any time dependent adjustment of model parameters. The emergence of such mechanisms due to spatial coupling demonstrates the importance of spatial interactions in modelling ictal dynamics, and in the study of ictogenesis
Standing waves as an explanation for generic stationary correlation patterns in noninvasive EEG of focal onset seizures.
No full textCerebral electrical activity is highly nonstationary because the brain reacts to ever changing external stimuli and continuously monitors internal control circuits. However, a large amount of energy is spent to maintain remarkably stationary activity patterns and functional inter-relations between different brain regions. Here we examine linear EEG correlations in the peri-ictal transition of focal onset seizures, which are typically understood to be manifestations of dramatically changing inter-relations. Contrary to expectations we find stable correlation patterns with a high similarity across different patients and different frequency bands. This skeleton of spatial correlations may be interpreted as a signature of standing waves of electrical brain activity constituting a dynamical ground state. Such a state could promote the formation of spatiotemporal neuronal assemblies and may be important for the integration of information stemming from different local circuits of the functional brain network
Isolation and characterization of mine-dwelling actinomycetes as potential producers of novel bioactive secondary metabolites
No full textEs ist allgemein bekannt, dass gegen zunehmend multiresistente Problemkeime neue Antibiotika dringend benötigt werden. Erfreulicherweise sind in der jüngsten Zeit aus Mikroorganismen isolierte Naturstoffe wieder verstärkt in den Mittelpunkt der Bemühungen um neue Antibiotika gerückt. Allerdings sind auch hier die Erfolgsmeldungen selten geworden. Dies vor allem, weil es mit den herkömmlichen Screening-Methoden kaum mehr gelingt, neuartige potente Organismen zu isolieren.
Einer der vorgeschlagenen Wege zur Erhöhung der Ausbeute ist die gezielte Suche an bisher kaum beachteten Habitaten. Die vorliegende Arbeit beschäftigt sich deshalb mit der mikrobiologischen Untersuchung der Feengrotten, einem ehemaligen Alaunschieferbergwerk, dessen Ökologie durch die herrschenden sauren Bedingungen und hohe Konzentrationen an gelösten Schwermetallen gekennzeichnet ist. Besonderes Augenmerk galt dabei den dort heimischen Actinomyceten, da Vertreter dieser Organismengruppe unbestreitbar zu den wichtigsten Quellen bioaktiver Naturstoffe gehören. Aus insgesamt 32 Proben wurden 86 zur Ordnung Actinomycetales gehörende Stämme isoliert, die unter anderem den Gattungen Amycolatopsis, Catenulispora, Kitasatospora, Kribbella, Pseudonocardia und Streptomyces zugeordnet werden konnten. Aufwendige polyphasiche Studien an den Isolaten führten schließlich zur formalen Beschreibung zweier neuer Arten, Amycolatopsis saalfeldensis sp. nov. und Kribbella aluminosa sp. nov.. Molekulartaxonomische Untersuchungen zeigten darüber hinaus, dass einige der aus den Feengrotten isolierten Stämme völlig neue phylogenetische Linien innerhalb der Klasse Actinobacteria bildeten. So konnte der Stamm HKI 501T einer neuen Gattung und Art, Fodinicola feengrottensis gen. nov., sp. nov. zugeordnet werden. Zahlreiche der Feengrotten-Isolate wiesen zudem hochwirksame biologische Aktivitäten gegen verbreitete Pathogene auf. Es bleibt zu testen, ob die zugrundeliegenden Wirkmechanismen neuartig sind oder nicht
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