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Fundamental Formulae For Wave-Energy Conversion, J Falnes, A Kurniawan Mar 2015

Fundamental Formulae For Wave-Energy Conversion, J Falnes, A Kurniawan

School of Biological and Marine Sciences

The time-average wave power that is absorbed from an incident wave by means of a wave-energy conversion (WEC) unit, or by an array of WEC units—i.e. oscillating immersed bodies and/or oscillating water columns (OWCs)—may be mathematically expressed in terms of the WEC units' complex oscillation amplitudes, or in terms of the generated outgoing (diffracted plus radiated) waves, or alternatively, in terms of the radiated waves alone. Following recent controversy, the corresponding three optional expressions are derived, compared and discussed in this paper. They all provide the correct time-average absorbed power. However, only the first-mentioned expression is applicable to quantify the …

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Creep Cavitation Bands Control Porosity And Fluid Flow In Lower Crustal Shear Zones, L Menegon, F Fusseis, H Stunitz, X Xiao Mar 2015

Creep Cavitation Bands Control Porosity And Fluid Flow In Lower Crustal Shear Zones, L Menegon, F Fusseis, H Stunitz, X Xiao

School of Geography, Earth and Environmental Sciences

Shear zones channelize fluid flow in Earth’s crust. However, little is known about deep crustal fluid migration and how fluids are channelized and distributed in a deforming lower crustal shear zone. This study investigates the deformation mechanisms, fluid-rock interaction, and development of porosity in a monzonite ultramylonite from Lofoten, northern Norway. The rock was deformed and transformed into an ultramylonite under lower crustal conditions (temperature = 700–730 °C, pressure = 0.65–0.8 GPa). The ultramylonite consists of feldspathic layers and domains of amphibole + quartz + calcite, which result from hydration reactions of magmatic clinopyroxene. The average grain size in both …

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Rf Transport Electromagnetic Properties Of Cvd Graphene From Dc To 110 Mhz, Sa Awan, G Pan, Lma Taan, B Li, N Jamil Feb 2015

Rf Transport Electromagnetic Properties Of Cvd Graphene From Dc To 110 Mhz, Sa Awan, G Pan, Lma Taan, B Li, N Jamil

School of Engineering, Computing and Mathematics

No abstract provided.

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Metagenomics Reveals Planktonic Bacterial Community Shifts Across A Natural Co2 Gradient In The Mediterranean Sea., Ashvini Chauhan, Ashish Pathak, Riccardo Rodolfo-Metalpa, Marco Milazzo, Stefan J. Green, Jason M. Hall-Spencer Feb 2015

Metagenomics Reveals Planktonic Bacterial Community Shifts Across A Natural Co2 Gradient In The Mediterranean Sea., Ashvini Chauhan, Ashish Pathak, Riccardo Rodolfo-Metalpa, Marco Milazzo, Stefan J. Green, Jason M. Hall-Spencer

School of Biological and Marine Sciences

Bacterial communities at a CO2 vent (pH 6.7) were compared with those at control (pH 8.0) and transition sites (pH 7.6) using 16S rRNA metagenomics. Firmicutes and unclassified bacteria dominated across all sites, Proteobacteria, especially Gammaproteobacteria, declined, and Epsilonproteobacteria increased in the vent with an increase in Bacteroidetes at both the vent and transition sites.

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The Pervasive Role Of Biological Cohesion In Bedform Development., Jonathan Malarkey, Jaco H. Baas, Julie A. Hope, Rebecca J. Aspden, Daniel R. Parsons, Jeff Peakall, David M. Paterson, Robert J. Schindler, Leiping Ye, Ian D. Lichtman, Sarah J. Bass, Alan G. Davies, Andrew J. Manning, Peter D. Thorne Feb 2015

The Pervasive Role Of Biological Cohesion In Bedform Development., Jonathan Malarkey, Jaco H. Baas, Julie A. Hope, Rebecca J. Aspden, Daniel R. Parsons, Jeff Peakall, David M. Paterson, Robert J. Schindler, Leiping Ye, Ian D. Lichtman, Sarah J. Bass, Alan G. Davies, Andrew J. Manning, Peter D. Thorne

School of Geography, Earth and Environmental Sciences

Sediment fluxes in aquatic environments are crucially dependent on bedform dynamics. However, sediment-flux predictions rely almost completely on clean-sand studies, despite most environments being composed of mixtures of non-cohesive sands, physically cohesive muds and biologically cohesive extracellular polymeric substances (EPS) generated by microorganisms. EPS associated with surficial biofilms are known to stabilize sediment and increase erosion thresholds. Here we present experimental data showing that the pervasive distribution of low levels of EPS throughout the sediment, rather than the high surficial levels of EPS in biofilms, is the key control on bedform dynamics. The development time for bedforms increases by up …

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The Value Of The Follow-Through Derives From Motor Learning Depending On Future Actions., Ian S. Howard, Daniel M. Wolpert, David W. Franklin Feb 2015

The Value Of The Follow-Through Derives From Motor Learning Depending On Future Actions., Ian S. Howard, Daniel M. Wolpert, David W. Franklin

School of Engineering, Computing and Mathematics

In ball sports, we are taught to follow through, despite the inability of events after contact or release to influence the outcome [1, 2]. Here we show that the specific motor memory active at any given moment critically depends on the movement that will be made in the near future. We demonstrate that associating a different follow-through movement with two motor skills that normally interfere [3-7] allows them to be learned simultaneously, suggesting that distinct future actions activate separate motor memories. This implies that when learning a skill, a variable follow-through would activate multiple motor memories across practice, whereas a …

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An Exposure-Effect Approach For Evaluating Ecosystem-Wide Risks From Human Activities, Am Knights, Gj Piet, Rh Jongbloed, Et Al Feb 2015

An Exposure-Effect Approach For Evaluating Ecosystem-Wide Risks From Human Activities, Am Knights, Gj Piet, Rh Jongbloed, Et Al

School of Biological and Marine Sciences

Ecosystem-based management (EBM) is promoted as the solution for sustainable use. An ecosystem-wide assessment methodology is therefore required. In this paper, we present an approach to assess the risk to ecosystem components from human activities common to marine and coastal ecosystems. We build on: (i) a linkage framework that describes how human activities can impact the ecosystem through pressures, and (ii) a qualitative expert judgement assessment of impact chains describing the exposure and sensitivity of ecological components to those activities. Using case study examples applied at European regional sea scale, we evaluate the risk of an adverse ecological impact from …

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Copper-Induced Intra-Specific Oxidative Damage And Antioxidant Responses In Strains Of The Brown Alga Ectocarpus Siliculosus With Different Pollution Histories, Ca Sáez, F Roncarati, A Moenne, Aj Moody, Mt Brown Feb 2015

Copper-Induced Intra-Specific Oxidative Damage And Antioxidant Responses In Strains Of The Brown Alga Ectocarpus Siliculosus With Different Pollution Histories, Ca Sáez, F Roncarati, A Moenne, Aj Moody, Mt Brown

School of Biological and Marine Sciences

Inter- and intra-specific variation in metal resistance has been observed in the ecologically and economically important marine brown macroalgae (Phaeophyceae), but the mechanisms of cellular tolerance are not well elucidated. To investigate inter-population responses of brown seaweeds to copper (Cu) pollution, the extent of oxidative damage and antioxidant responses were compared in three strains of the filamentous brown seaweed Ectocarpus siliculosus, the model organism for the algal class Phaeophyceae that diverged from other major eukaryotic groups over a billion year ago. Strains isolated from locations with different pollution histories (i.e. LIA, from a pristine site in Scotland; REP and Es524 …

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Understanding The Gender And Ethnicity Attainment Gap In Uk Higher Education, Dre Cotton, M Joyner, R George, Pa Cotton Jan 2015

Understanding The Gender And Ethnicity Attainment Gap In Uk Higher Education, Dre Cotton, M Joyner, R George, Pa Cotton

School of Biological and Marine Sciences

In recent years the success rates of different groups of students in higher education (HE), have come under considerable scrutiny, with gender and ethnicity identified as key attributes predicting differential achievement of ‘good degrees’. A review of previous studies highlights the need for research which looks beyond ‘the deficit model’ to explain the attainment gap. This research used a mixed-methods approach to explore the academic and social experiences of students, as well as lecturers’ views on student achievement, in one UK University. Findings suggest that there are significant differences in motivation and confidence speaking English for different ethnic groups in …

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Bicyclic Naphthenic Acids In Oil Sands Process Water: Identification By Comprehensive Multidimensional Gas Chromatography-Mass Spectrometry., Michael J. Wilde, Charles E. West, Alan G. Scarlett, David Jones, Richard A. Frank, L. Mark Hewitt, Steven J. Rowland Jan 2015

Bicyclic Naphthenic Acids In Oil Sands Process Water: Identification By Comprehensive Multidimensional Gas Chromatography-Mass Spectrometry., Michael J. Wilde, Charles E. West, Alan G. Scarlett, David Jones, Richard A. Frank, L. Mark Hewitt, Steven J. Rowland

School of Geography, Earth and Environmental Sciences

Although bicyclic acids have been reported to be the major naphthenic acids in oil sands process-affected water (OSPW) and a well-accepted screening assay indicated that some bicyclics were the most acutely toxic acids tested, none have yet been identified. Here we show by comprehensive multidimensional gas chromatography-mass spectrometry (GC×GC-MS), that >100 C8-15 bicyclic acids are typically present in OSPW. Synthesis or purchase allowed us to establish the GC×GC retention times of methyl esters of numerous of these and the mass spectra and published spectra of some additional types, allowed us to identify bicyclo[2.2.1]heptane, bicyclo[3.2.1]octane, bicyclo[4.3.0]nonane, bicyclo[3.3.1]nonane and bicyclo[4.4.0]decane acids in …

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Spatial Navigation In Autism Spectrum Disorders: A Critical Review, Alastair D. Smith Jan 2015

Spatial Navigation In Autism Spectrum Disorders: A Critical Review, Alastair D. Smith

School of Psychology

No abstract provided.

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Developmental Telomere Attrition Predicts Impulsive Decision-Making In Adult Starlings, M Bateson, Bo Brilot, R Gillespie, P Monaghan, D Nettle Jan 2015

Developmental Telomere Attrition Predicts Impulsive Decision-Making In Adult Starlings, M Bateson, Bo Brilot, R Gillespie, P Monaghan, D Nettle

School of Biological and Marine Sciences

Animals in a poor biological state face reduced life expectancy, and as a consequence should make decisions that prioritize immediate survival and reproduction over long-term benefits. We tested the prediction that if, as has been suggested, developmental telomere attrition is a biomarker of state and future life expectancy, then individuals who have undergone greater developmental telomere attrition should display greater choice impulsivity as adults. We measured impulsive decision-making in a cohort of European starlings (Sturnus vulgaris) in which we had previously manipulated developmental telomere attrition by cross-fostering sibling chicks into broods of different sizes. We show that as predicted by …

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Linkages Between Reach-Scale Physical Habitat And Invertebrate Assemblages In Upland Streams, Victoria S. Milner, Nigel J. Willby, David J. Gilvear, Charles Perfect Jan 2015

Linkages Between Reach-Scale Physical Habitat And Invertebrate Assemblages In Upland Streams, Victoria S. Milner, Nigel J. Willby, David J. Gilvear, Charles Perfect

School of Geography, Earth and Environmental Sciences

Determining the influence of physical habitat on biological structure in minimally disturbed settings is important if the effects of alterations to physical habitat are to be understood. This study tested whether reach-scale differences in physical habitat influence macroinvertebrate community composition at 24 sites in the Cairngorm Mountains, Scotland. Stream reaches were classified into channel types based on a geomorphic typology (i.e. step-pool, bedrock, plane-bed and pool-riffle). PERMANOVA indicated an overall significant relationship between the geomorphic typology and macroinvertebrate species-level composition, and among all combinations of channel types (such as steppool and pool-riffle, step-pool and bedrock). Most channel types were dominated …

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An Experimental Demonstration That Early-Life Competitive Disadvantage Accelerates Telomere Loss, D Nettle, P Monaghan, R Gillespie, Et Al Jan 2015

An Experimental Demonstration That Early-Life Competitive Disadvantage Accelerates Telomere Loss, D Nettle, P Monaghan, R Gillespie, Et Al

School of Biological and Marine Sciences

Adverse experiences in early life can exert powerful delayed effects on adult survival and health. Telomere attrition is a potentially important mechanism in such effects. One source of early-life adversity is the stress caused by competitive disadvantage. Although previous avian experiments suggest that competitive disadvantage may accelerate telomere attrition, they do not clearly isolate the effects of competitive disadvantage from other sources of variation. Here, we present data from an experiment in European starlings (Sturnus vulgaris) that used cross-fostering to expose siblings to divergent early experience. Birds were assigned either to competitive advantage (being larger than their brood competitors) or …

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Unsettling Sustainability: The Poetics Of Discomfort, Mandy Bloomfield Jan 2015

Unsettling Sustainability: The Poetics Of Discomfort, Mandy Bloomfield

School of Law, Humanities and Social Sciences

No abstract provided.

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Height, Crime And Colonial History, Hamish Maxwell-Stewart, Matthew Cracknell, Kris Inwood Jan 2015

Height, Crime And Colonial History, Hamish Maxwell-Stewart, Matthew Cracknell, Kris Inwood

SOLON Law, Crime and History (previously SOLON Crimes and Misdemeanours: Deviance and the Law in Historical Perspective)

Since the 1970s historians interested in the impact of changing social and economic conditions on health outcomes have studied record collections that contain information about adult stature. Fluctuations in mean height by year of birth are potentially informative because they should reflect conditions encountered in utero and during the early years of life. Yet, like all historical records, surviving height series are not necessarily representative of the population as a whole. They are also subject to factors that might change over time. This article uses Tasmania nineteenth century criminal record series to explore these issues in greater depth. It is …

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The Role Of Lysophosphatidylcholine Acyltransferase (Lpcat) 3 In Macrophage Inflammatory Responses, Confidence Obianuju Okorie Jan 2015

The Role Of Lysophosphatidylcholine Acyltransferase (Lpcat) 3 In Macrophage Inflammatory Responses, Confidence Obianuju Okorie

School of Biomedical Sciences Theses

Sepsis is the systemic response to infection and is characterised by the presence of Severe Inflammatory Response Syndrome (SIRS) in addition to a documented or presumed infection. It is an important reason for admission into the Intensive Care Unit (ICU), the leading cause of death in non-coronary ICU’s and one of the most common causes of death among hospitalized patients. It affects 18 million people worldwide each year with over 7.3 million fatalities. Molecules such as endotoxin, the Lipopolysaccharide (LPS) present in the outer membrane of Gram-negative bacteria, are key factors in the pathogenesis of sepsis. The activation of macrophages …

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Effect Of Mesoscale Variability Of Water Masses On Acoustic Wave Propagation In A Shallow Sea, Feng Chen Jan 2015

Effect Of Mesoscale Variability Of Water Masses On Acoustic Wave Propagation In A Shallow Sea, Feng Chen

School of Biological and Marine Sciences Theses

Anthropogenic noise in the sea is now classed as a pollutant alongside chemical pollution and marine litter in accordance with the Marine Strategy Framework Directive. Noise from shipping is a major contributor to the ambient noise levels in the ocean, particularly at low (<300Hz) frequencies. The properties of sound propagation in shallow waters are highly influenced by the marine physical environment. Ocean modelling plays an important role in underwater noise studies since it can provide high resolution water column parameters over large geographic areas. This study investigates the noise patterns and their temporal variations in the Celtic Sea by using a coupled ocean model (POLCOMS) and an acoustic model (HARCAM). A method to predict noise exposure experienced by marine animals is then developed, following an application for diving seals. The ocean model is applied in the Celtic Sea to provide high-resolution 3D hourly temperature and salinity fields for the acoustic model. The model is validated against in-situ and satellite observations, giving high skills to simulate the water column structures. Sensitivity studies of modelled results to different atmospheric forcing are carried out in order to improve the accuracy of the model. The results show that the modelled sea surface temperature, stratification and water column structures are highly sensitive to the choice of surface forcing, especially in the summer time. The increase in resolution of surface forcing does not necessarily lead to more accurate results. The tidally frontal position is, however, insensitive to the forcing. The variability of noise propagation is studied using the coupled model, demonstrating high dependence on oceanographic conditions, geographic location of sound source and its depth. In summer, when the source of sound is on the inshore side of the bottom front, the sound energy is mostly concentrated in the near-bottom layer. In winter, the sound from the same source is distributed more evenly in the vertical. When the source is on the seaward side of the front, the sound level from a shallow source is nearly uniform in the vertical and the transmission loss is significantly greater (~16dB at 40km distance) in summer than in winter. In contrast, sound energy from a deep source is trapped in the bottom cold water, leading to a much lower transmission loss (~20dB) in summer than in winter. Note that ~10dB fluctuation of sound energy is found during the deterioration of the thermocline in late autumn. Shallow sources (e.g. ships) are sensitive to the surface heat flux as it changes significantly the vertical temperature gradient, while tides play an important role in determining the TL variability of deeper sources (e.g. pile driving) since they cause adjustments of positions of subsurface fronts. The seasonal noise patterns radiated by a large cargo ship are modelled by relating the AIS ship track data and the coupled model, showing a clear influence of the seasonal thermocline and associated bottom fronts on shipping noise distribution. The noise propagates much further (tens of kilometres) in winter than in summer. The predicted shipping noise exposure perceived by grey seals shows strong step changes in the sound level during their descent/ascent through the water column. Since grey seals tend to be benthic foragers, a hypothesis that the step change in sound exposure may have negative impacts on their foraging behaviour is proposed for biological specialists.

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The Effect Of Dietary Probiotics On Nile Tilapia, Oreochromis Niloticus, Health And Growth Performance, Benedict Standen Jan 2015

The Effect Of Dietary Probiotics On Nile Tilapia, Oreochromis Niloticus, Health And Growth Performance, Benedict Standen

School of Biological and Marine Sciences Theses

Three investigations were conducted in order to investigate the effect of dietary probiotics on tilapia (Oreochromis niloticus) growth performance, intestinal morphology, intestinal microbiology and immunity. The first experiment demonstrated that Bacillus subtilis, Lactobacillus reuteri and Pediococcus acidilactici supplemented individually and as a mixed probiotic (in addition to Enterococcus faecium; AquaStar® Growout) were capable of modulating intestinal microbial populations as determined by culture dependent methods and DGGE. Furthermore, high-throughput sequencing reported that >99% of 16S rRNA reads in the mixed probiotic group belonged to the probiotic genera, predominantly assigned to Enterococcus (52.50%) and Bacillus (45.94%). Tilapia in the mixed probiotic group …

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Adverse Childhood Experience And Asthma Onset: A Systematic Review, Daniel Exley, Alyson Norman, Michael Hyland Jan 2015

Adverse Childhood Experience And Asthma Onset: A Systematic Review, Daniel Exley, Alyson Norman, Michael Hyland

School of Psychology

Adverse childhood experiences such as abuse and neglect are associated with subsequent immune dysregulation. Some studies show an association between adverse childhood experiences and asthma onset, although significant disparity in results exists in the published literature.We aimed to review available studies employing a prospective design that investigates associations between adverse childhood experience and asthma. A search protocol was developed and studies were drawn from four electronic journal databases. Studies were selected in accordance with pre-set inclusion criteria and relevant data were extracted.12 studies, assessing data from a total of 31 524 individuals, were identified that investigate the impact of a …

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Mitochondrial Involvement In Pancreatic Beta Cell Glucolipotoxicity, Jonathan Barlow Jan 2015

Mitochondrial Involvement In Pancreatic Beta Cell Glucolipotoxicity, Jonathan Barlow

School of Biomedical Sciences Theses

High circulating glucose and non-esterified free fatty acid (NEFA) levels can cause pancreatic β-cell failure. The molecular mechanisms of this β-cell glucolipotoxicity are yet to be established conclusively. In this thesis by exploring mitochondrial energy metabolism in INS-1E insulinoma cells and isolated pancreatic islets, a role of mitochondria in pancreatic β-cell glucolipotoxicity is uncovered. It is reported that prolonged palmitate exposure at high glucose attenuates glucose-stimulated mitochondrial respiration which is coupled to ADP phosphorylation. These mitochondrial defects coincide with an increased level of mitochondrial reactive oxygen species (ROS), impaired glucose-stimulated insulin secretion (GSIS) and decreased cell viability. Palmitoleate, on the …

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Foraminifera Of The Fal Estuary (Cornwall), Including Taxa Associated With Maerl Beds, Mb Hart, K Cartwright, B Fisk, Cw Smart, C Consolaro, Jm Hall-Spencer Jan 2015

Foraminifera Of The Fal Estuary (Cornwall), Including Taxa Associated With Maerl Beds, Mb Hart, K Cartwright, B Fisk, Cw Smart, C Consolaro, Jm Hall-Spencer

School of Geography, Earth and Environmental Sciences

No abstract provided.

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The Common Agricultural Policy: An Adequate Means Of Supporting Biodiversity And Ecosystem Services Within The European Union?, Annie Martyn Jan 2015

The Common Agricultural Policy: An Adequate Means Of Supporting Biodiversity And Ecosystem Services Within The European Union?, Annie Martyn

The Plymouth Law and Criminal Justice Review

This research presents a critical analysis of the 2013 Common Agricultural Policy (CAP) reforms and their ability to support the European Union in reaching its target of halting biodiversity loss by 2020 and to preserve and restore ecosystem services. In light of the link between agriculture and its negative effects on the environment, the role of the CAP will be examined. In particular, this paper will focus on the tension between the ambition set out in the Policy to provide sufficient economic support to farmers and the EU-wide focus to prevent further environmental damage caused by agriculture, and whether, in …

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Europeanization, Environmental Policy And The Uk, Analyzing Perspectives Of Offshore Wind Farms And Planning Procedures, Samantha Loveridge Jan 2015

Europeanization, Environmental Policy And The Uk, Analyzing Perspectives Of Offshore Wind Farms And Planning Procedures, Samantha Loveridge

The Plymouth Law and Criminal Justice Review

Sustainable development is an important principle for improving human life and ensuring the wellbeing of the planet. It posits a desirable future for human societies in which living conditions and resource-use meet human needs, without undermining the sustainability of natural systems and the environment, so that future generations may also have their needs met. It ties together concerns for the capacity of natural systems and challenges faced by humanity which concentrates on a balance between social, economic and environmental variables in relation to current and future existence. To accomplish a successful balance of these variables a transition is required which …

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High Times: An Ethnography Of Young Adult Drug Use, Ben Coombe Jan 2015

High Times: An Ethnography Of Young Adult Drug Use, Ben Coombe

The Plymouth Law and Criminal Justice Review

This research explores the phenomenon of 'legal highs' or Novel Psychoactive Substances (NPS), directing substantial focus towards the exploration of user attraction. Whilst legal high research is expanding, the topic of legal highs still remains a relatively under-researched topic. In particular, research concerning the user is in short supply, as policy makers remain detached from the importance of understanding the attraction for users (Winstock and Ramsey, 2010). Therefore, this paper attempts to capitalise in the expansion of this knowledge and discover what reasons users attribute for the use of these psychoactive substances. A comprehensive review of the current literature has …

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The Geomorphological Development Of Ephemeral And Relict River Valley Systems In The North Part Of The Iraqi Western Desert, Waleed Hamed Jan 2015

The Geomorphological Development Of Ephemeral And Relict River Valley Systems In The North Part Of The Iraqi Western Desert, Waleed Hamed

School of Geography, Earth and Environmental Sciences Theses

This research project provides a geomorphological and geological analysis of ephemeral and relict river valley systems in the north part of the Iraqi Western Desert. The area surveyed covers approximately 30 000 km2 and is one of the remotest and least studied parts of the Arabian Peninsula. Part of the reason for the lack of research in this area in recent years has been the ongoing security problems and all fieldwork undertaken for this thesis was carried out with the support of armed guards and police. In addition much of the work on the geology and geomorphology of the region …

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Advanced Applications Of Cardiac Computed Tomography For The Difficult-To-Image Patient, Benjamin James Clayton Jan 2015

Advanced Applications Of Cardiac Computed Tomography For The Difficult-To-Image Patient, Benjamin James Clayton

Peninsula Medical School Theses

Throughout the development of computed tomographic (CT) imaging the challenges of capturing the heart, with its perpetual, vigorous motion, and in particular the tiny detail within the coronary arteries, has driven technological progress. Today, CT is a widely used and rapidly growing modality for the investigation of coronary artery disease, as well as other cardiac pathology. However, limitations remain and particular patient groups present a significant challenge to the CT operator. This thesis adds new knowledge to the assessment of these difficult-to-image patients. It considers patients with artefact from coronary artery calcification or stents, examining the remarkable diagnostic performance of …

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An Electrophysiological Investigation Of Reward Prediction Errors In The Human Brain, Thomas Sambrook Jan 2015

An Electrophysiological Investigation Of Reward Prediction Errors In The Human Brain, Thomas Sambrook

School of Psychology Theses

Reward prediction errors are quantitative signed terms that express the difference between the value of an obtained outcome and the expected value that was placed on it prior to its receipt. Positive reward prediction errors constitute reward, negative reward prediction errors constitute punishment. Reward prediction errors have been shown to be powerful drivers of reinforcement learning in formal models and there is thus a strong reason to believe they are used in the brain. Isolating such neural signals stands to help elucidate how reinforcement learning is implemented in the brain, and may ultimately shed light on individual differences, psychopathologies of …

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Cognitive Processes In Craving: From The Laboratory To The Real World., Jessica Skorka-Brown Jan 2015

Cognitive Processes In Craving: From The Laboratory To The Real World., Jessica Skorka-Brown

School of Psychology Theses

Elaborated Intrusion (EI) Theory posits that craving involves mental imagery in the same sensory modalities as the craved substance or activity. Visual imagery predominates, therefore craving should selectively interfere with performance on visual task, and conversely visual tasks should interfere with craving. This thesis reports tests of this prediction, both in the laboratory and real-world settings, to provide a basis for designing practical tasks for interfering with cravings in a natural environment. Contrary to predictions, experiments 1 and 2 showed no effect of craving on visual or verbal task performance. There were, however, effects of task performance on craving in …

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Factors Associated With Stiff Knee Gait In Cerebral Palsy, Eleanor Frances Compton Jan 2015

Factors Associated With Stiff Knee Gait In Cerebral Palsy, Eleanor Frances Compton

Other Faculty of Health Theses

Stiff knee gait (SKG) is one of a few classified walking patterns which people with cerebral palsy (pwCP) can present with. The characteristic for SKG is delayed and/or reduced peak knee flexion during swing phase, which can reduce walking ability and result in functional restrictions. Through the use of both clinical and laboratory based measures this cross-sectional study aimed to identify the factors associated with SKG, suggest possible treatment options and propose potential directions for future research. The impact of five variables on knee flexion amplitude during the swing phase of gait was assessed. Data was gathered from a group …

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