Temporal Processing Deficits in Children with Dyslexia and Developmental Coordination Disorder

This thesis set out to examine whether temporal processing deficits were evident in both children with developmental dyslexia and children with developmental coordination disorder (DCD), and if there were, whether there were similar patterns of deficits in both conditions which suggest evidence of a possible underlying cognitive deficit common to both conditions, as suggested by some researchers (for example, Kaplan, Wilson, Dewey, and Crawford, 1998, and Nicolson, 2000). A pilot study was carried out to investigate the feasibility of initial tasks that may be used in main studies. The findings from this study suggested automatisation and temporal processing may be areas to explore further. Consequently, Study One began by investigating the performance of children with dyslexia, DCD and typically developing children on a rapid naming task. The duration of their articulations and non-articulations was measured and the results indicated that the children with dyslexia showed longer and more variable non-articulation durations than the other two groups; the children with DCD had significantly longer articulation durations than the other two groups. Main Study Two investigated whether there were temporal production deficits in the two special needs groups relative to controls. The findings here suggested a subtle auditory deficit in children with dyslexia, however the children with DCD did not differ significantly from the typically developing group. Main Study Three investigated temporal perception, using a temporal generalisation task. This study found no significant differences between the groups on their performance on the task, but intergroup correlations suggested that the ability to carry out temporal generalisations was associated with different abilities in each group. Finally, Main Study Four looked at temporal order judgements (TOJs) across several modalities by using different types of stimuli: phonological stimuli, tones, shapes, and letters. Here, the children with dyslexia were significantly less accurate than the other two groups in making TOJs with phonological stimuli, but the children with DCD were not significantly different from the controls. All children performed least accurately on the tone condition suggesting that the nature of this condition is generally difficult. The results do not support the hypothesis that there is a general temporal processing deficit in children with dyslexia or children with DCD or that this may be a common deficit between the two conditions. However, the findings were in line with the idea that children with dyslexia have a phonological and / or speech perception deficit, and further work with children who have DCD needs to be conducted to study the heterogeneity of this condition at the cognitive level

Coral Disease and the Environment in the Pacific Ocean

Coral diseases are a major threat to coral reef health and functioning worldwide. Little is known about how coral disease prevalence relates to multiple interacting changes in host densities, abiotic stressors, and levels of human impact. In particular, almost nothing is known about coral disease dynamics under changing abiotic conditions in the absence of direct anthropogenic stressors. Understanding how disease dynamics change relative to shifts in environmental conditions is crucial for the successful management and future survival of coral reefs. With the use of existing and novel field data and statistical modeling I examined the associations (abiotic and biotic) of multiple coral disease states across a variety of spatial scales encompassing a wide range of environmental conditions. Biomedical techniques were then used to relate these environmental associations to potential disease etiology. Study sites included areas with high levels of anthropogenic impact (e.g. Oahu, main Hawaiian Islands); to extremely remote quasi-pristine reefs removed from direct human influence (e.g. Palmyra Atoll National Wildlife Refuge). Over small spatial scales (100s m) at a marine reserve in the main Hawaiian Islands I modelled the spatial patterns of four coral diseases (Porites growth anomalies, Porites tissue loss, Porites trematodiasis and Montipora white syndrome). While Porites tissue loss and Montipora white syndrome were positively associated with poor environmental conditions (poor water quality, low coral cover), Porites growth anomalies and Porites trematodiasis were more prevalent in areas considered to be of superior quality (clearer water, increased host abundance, higher numbers of fish). At Palmyra Atoll, fatal tissue loss diseases were largely absent and although coral growth anomalies were present their prevalence was extremely low. Patterns of growth anomaly prevalence at Palmyra were positively associated with host abundance across four coral genera (Acropora, Astreopora, Montipora and Porites) and generally negatively associated with algal cover. Growth anomalies, although progressive and detrimental to the hosts, were most prevalent in the "healthiest" regions (the highest coral cover regions) of Palmyra. I hypothesised that differences seen in the types and prevalence of coral diseases between heavily populated parts of Hawaii and remote uninhabited locations such as Palmyra Atoll, could be a result of differing levels of either direct (e.g. pollution) or indirect (e.g. pollution leading to loss of key hosts) human stressors, in addition to natural changes in the environment. To begin disentangling the confounding effects of natural variability and human stressors on coral disease prevalence patterns I modelled two diseases (Acropora and Porites growth anomalies) across hundreds of sites throughout the Indo-Pacific Ocean (1000s km). Predictors included host densities, human population numbers, frequency of sea surface temperature anomalies, and input of ultra-violet radiation. Porites growth anomaly prevalence was positively associated with human population density (and to a lesser extent host density), while the prevalence of Acropora growth anomalies was strongly host density dependent. The positive association between the prevalence of Porites growth anomalies and human density suggests the presence and prevalence of the disease are related, directly or indirectly, to some environmental co-factor associated with increased human density at regional spatial scales. Although this association has been widely posited, this is one of the first wide scale studies unambiguously linking a coral disease with human population size. In summary, the types of coral diseases observed, their prevalence, and spatial patterns of distribution within reef systems are the result of multiple abiotic and biotic factors and stressors interacting, in some cases synergistically. Statistical modelling, in conjunction with biomedical techniques and field observations, proved essential to the understanding of coral disease ecology within single reefs and atolls to patterns across entire oceans

The New Dual Antiplatelet Therapy Agents And Their Role in Acute Coronary Syndrome

Background: Prasugrel and ticagrelor are two novel antiplatelet agents, which have been subject to large randomized trials to compare their efficacy with clopidogrel for patients with acute coronary syndrome (ACS).Aim: To conduct a systematic review of prasugrel and ticagrelor as alternative therapy to clopidogrel in patients who present with ACS undergoing PCI.Methods: The articles cited in this paper were searched on PubMed, MEDLINE, and Plymouth University’s Metalib database. The search terms used included “dual antiplatelet therapy”, “prasugrel”, “ticagrelor”, and “clopidogrel resistance”. Discussion: The main indications for the use of prasugrel based on current understanding are patients presenting with acute STEMI referred for primary PCI, ACS patients with DM, or those who have a high risk of stent thrombosis. Ticagrelor, on the other hand, may provide optimal benefit for patients with NSTEMI treated with conservative or invasive therapy, those with previous TIA or stroke, advanced age, or small body surface. Conclusion: Prasugrel and ticagrelor have been shown to be adequate P2Y12 antiplatelet therapy alternatives to clopidogrel in the management of patients with ACS. While prasugrel and ticagrelor have both been shown to clinically improve platelet inhibition and significantly reduce the incidence of stent thrombosis compared with clopidogrel therapy, both increase the risk of a significant bleeding incident. Both ticagrelor and prasugrel have been shown to be appropriate and effective treatment alternatives for ACS patients who display clopidogrel treatment resistance or failure

Using pressure recovery at a depleted gas field to understand saline aquifer connectivity

A key uncertainty facing Carbon dioxide Capture and Storage (CCS) in saline aquifers is long term injectivity, which is primarily a function of the connected aquifer pore-volume within which formation brine can be displaced as the CO2 is injected. Protracted injection testing to interrogate and prove the far-field connected pore-volume would increase the lead-in times for commissioning of storage sites and would significantly increase appraisal costs. Here we use natural gas production and subsequent reservoir recharge legacy data from the Esmond gas field in the UK sector of the southern North Sea to gain an understanding of the dynamic behaviour of the Bunter Sandstone, a major saline aquifer. Results suggest that Esmond has a connected pore volume of 1.83x1010 m3, suitable for injecting CO2 at a rate of up to 2 million tonnes per year for at least 55 years. 3D seismic data suggest that Esmond reservoir properties are likely to be replicated across the wider Bunter Sandstone aquifer, notably around the Endurance structure which was, until recently, proposed for a full-chain CCS project

Cross-international boundary effects of CO2 injection

The Bunter Sandstone Formation in the Southern North Sea is a regional saline aquifer that extends across the median line between UK and Netherlands territorial waters. Numerical simulations of CO2 injection into a brine-saturated structural closure located in the UK sector have modelled the temporal development of an injection-induced pressure footprint, together with the potential role of faults in brine migration and pressure dissipation in the aquifer. The modelled pressure footprint extends into the Netherlands Sector and if the faults are considered migration pathways, brine expulsion rates of the order of 50 m3/day/km2 could be expected along the fault zones. This is equivalent to just over 105 Ml, during a 50 year injection period, of which approximately 40% is expelled along a fault beneath Netherlands territorial waters. The simulations have shown that brine displacement will facilitate CO2 injection into the Bunter Sandstone by alleviating pressure build-up, but an understanding of potential brine migration pathways, rates and environmental impacts must be demonstrated to regulators prior to injection

Introduction and spread of non-native parasites with Silurus glanis L. (Teleostei: Siluridae) in UK fisheries

Despite growing concern of the ecological risks posed by the European catfish Siluris glanis L. in freshwater fisheries, little information exists on the parasite fauna of this silurid catfish in Britain. Parasitological examinations of released S. glanis from four still-water fisheries in England revealed the presence of Thaparocleidus vistulensis (Siwak, 1932) and Ergasilus sieboldi (Nordmann, 1832), both non-native parasites, the latter known to be an important fish pathogen. This represents the first record of T. vistulensis from British freshwater fish. The human-assisted movement of S. glanis between UK recreational still-water fisheries provides a clear avenue for the introduction and spread of non-native parasites

Automated, high accuracy classification of Parkinsonian disorders: a pattern recognition approach

Progressive supranuclear palsy (PSP), multiple system atrophy (MSA) and idiopathic Parkinson’s disease (IPD) can be clinically indistinguishable, especially in the early stages, despite distinct patterns of molecular pathology. Structural neuroimaging holds promise for providing objective biomarkers for discriminating these diseases at the single subject level but all studies to date have reported incomplete separation of disease groups. In this study, we employed multi-class pattern recognition to assess the value of anatomical patterns derived from a widely available structural neuroimaging sequence for automated classification of these disorders. To achieve this, 17 patients with PSP, 14 with IPD and 19 with MSA were scanned using structural MRI along with 19 healthy controls (HCs). An advanced probabilistic pattern recognition approach was employed to evaluate the diagnostic value of several pre-defined anatomical patterns for discriminating the disorders, including: (i) a subcortical motor network; (ii) each of its component regions and (iii) the whole brain. All disease groups could be discriminated simultaneously with high accuracy using the subcortical motor network. The region providing the most accurate predictions overall was the midbrain/brainstem, which discriminated all disease groups from one another and from HCs. The subcortical network also produced more accurate predictions than the whole brain and all of its constituent regions. PSP was accurately predicted from the midbrain/brainstem, cerebellum and all basal ganglia compartments; MSA from the midbrain/brainstem and cerebellum and IPD from the midbrain/brainstem only. This study demonstrates that automated analysis of structural MRI can accurately predict diagnosis in individual patients with Parkinsonian disorders, and identifies distinct patterns of regional atrophy particularly useful for this process