Identifying solutions to increase participation in physical activity interventions within a socio-economically disadvantaged community: a qualitative study

Background: There is an urgent need to increase population levels of physical activity, particularly amongst those who are socio-economically disadvantaged. Multiple factors influence physical activity behaviour but the generalisability of current evidence to such ‘hard-to-reach’ population subgroups is limited by difficulties in recruiting them into studies. Also, rigorous qualitative studies of lay perceptions and perceptions of community leaders about public health efforts to increase physical activity are sparse. We sought to explore, within a socio-economically disadvantaged community, residents’ and community leaders’ perceptions of physical activity (PA) interventions and issues regarding their implementation, in order to improve understanding of needs, expectations, and social/environmental factors relevant to future interventions.

Methods: Within an ongoing regeneration project (Connswater Community Greenway), in a socio-economically disadvantaged community in Belfast, we collaborated with a Community Development Agency to purposively sample leaders from public- and voluntary-sector community groups and residents. Individual semi-structured interviews were conducted with 12 leaders. Residents (n=113), of both genders and a range of ages (14 to 86 years) participated in focus groups (n=14) in local facilities. Interviews and focus groups were recorded, transcribed verbatim and analysed using a thematic framework.

Results: Three main themes were identified: awareness of PA interventions; factors contributing to intervention effectiveness; and barriers to participation in PA interventions. Participants reported awareness only of interventions in which they were involved directly, highlighting a need for better communications, both inter- and intra-sectoral, and with residents. Meaningful engagement of residents in planning/organisation, tailoring to local context, supporting volunteers, providing relevant resources and an ‘exit strategy’ were perceived as important factors related to intervention effectiveness. Negative attitudes such as apathy, disappointing experiences, information with no perceived personal relevance and limited access to facilities were barriers to people participating in interventions.

Conclusions: These findings illustrate the complexity of influences on a community’s participation in PA interventions and support a social-ecological approach to promoting PA. They highlight the need for cross-sector working, effective information exchange, involving residents in bottom-up planning and providing adequate financial and social support. An in-depth understanding of a target population’s perspectives is of key importance in translating PA behaviour change theories into practice.

Enhancing the Efficiency of Slit-Coupling to Surface-Plasmon Polariton via Dispersion Engineering

We describe a simple method for enhancing the efficiency of coupling from a free-space transverse-magnetic (TM) plane-wave mode into a surface-plasmon-polariton (SPP) mode. The coupling structure consists a metal film with a dielectric-filled slit and a planar, dielectric layer on the slit-exit side of the metal film. By varying the dielectric layer thickness, the wavevector of the SPP mode on the metal surface can be tuned to match the wavevector magnitude of the modes emanating from the slit exit, enabling high-efficiency radiation coupling into the SPP mode at the slit exit. An optimal dielectric layer thickness of approximately 100 nm yields a visible-frequency SPP coupling efficiency approximately 4 times greater than the SPP coupling efficiency without the dielectric layer. Commensurate coupling enhancement is observed spanning the free-space wavelength range 400 nm < or = lambda(0) < or = 700 nm. We map the dependence of the SPP coupling efficiency on the slit width, the dielectric-layer thickness, and the incident wavelength to fully characterize this SPP coupling methodology

A RAG System for the Management Forensic and Archaeological Searches of Burial Grounds

Burial grounds are commonly surveyed and searched by both police/humanitarian search teams and archaeologists.
One aspect of an efficient search is to establish areas free of recent internments to allow the concentration of assets in suspect
terrain. While 100% surety in locating remains can never be achieved, the deployment of a red, amber green (RAG) system for
assessment has proven invaluable to our surveys. The RAG system is based on a desktop study (including burial ground
records), visual inspection (mounding, collapses) and use of geophysics (in this case, ground penetrating radar or GPR) for a
multi-proxy assessment that provides search authorities an assessment of the state of inhumations and a level of legal backup
for decisions they make on excavation or not (‘exit strategy’). The system is flexible and will be built upon as research
continues.

Measuring critical thinking skills and dispositions in undergraduate students

This thesis investigates critical thinking with a particular focus on measurement in undergraduate students. A higher education context was chosen because many regard critical thinking development as a primary goal for third level education. Nine studies, both cross-sectional and longitudinal in design, were conducted with undergraduate psychology students (N=387), using the California Critical Thinking Disposition Inventory (CCTDI) and the California Critical Thinking Skills Test (CCTST). Studies 1-3 revealed psychometric weaknesses in the CCTDI and revised the scale with factor analysis and reliability analysis to form the CCTDI United Kingdom revision (CCTDI-UK). Study 4 investigated convergent validity and showed significant inter-correlation between the sub-scales of the CCTDI-UK, and significant correlations with the Openness scale of the NEO Personality Inventory (NEO PI-R). The study also provided evidence for improvement in scores on three of the six sub-scales in the CCTDI-UK (Truth-Seeking, Inquisitiveness, Open-Mindedness) during the course of an undergraduate degree. Study 5 explored a two factor structure for critical thinking dispositions. Study 6 used reliability analysis to revise the CCTST to produce the CCTST-UK. Study 7 showed that the CCTST-UK had a moderate correlation with degree attainment and a slightly higher correlation with a test of non-verbal intelligence (Raven’s Advanced Progressive Matrices short form); in addition, the study showed that scores on the CCTST-UK improved during the course of the degree. Studies 8 and 9 investigated the potential of critical thinking for predicting degree attainment. A-levels predicted approximately 10% of the variance of degree attainment while entry level scores on the CCTST-UK predicted an additional 5%. Exit level scores on the CCTST-UK and the Inquisitive sub-scale of the CCTDI-UK were found to be predictors of degree attainment The main conclusions of the thesis were that these tests had significant potential for predicting degree attainment and that they measured a substantial proportion of the theoretical constructs identified by the major authors in critical thinking.

Young people exiting homelessness: An exploration of process, meaning and definition

In the past decade in particular, research attention has shifted from an almost exclusive focus on routes or pathways into homelessness towards the investigation of exits from homelessness. As well as demonstrating the multiple paths possible for young people who become homeless, recent research, and longitudinal studies in particular, has contributed to a more nuanced understanding of the complexity of the homeless pathways of young people. Nonetheless, knowledge and understanding of the nature of homeless exits, and of the mechanisms that facilitate the transition out of homelessness, is far from complete. This paper explores the processes surrounding the exit routes taken by young people out of homelessness and the meanings attached by them to these housing transitions based on selected findings from an ongoing qualitative longitudinal study of homeless youth in Dublin, Ireland. More broadly, the paper considers the utility of distinguishing between the types of routes that young people take out of homelessness, with particular attention to the notions of ‘independent’ and ‘dependent’ exits. The paper aims to further the discussion and debate on the conceptualisation of homeless exits and also discusses a number of policy implications arising from the study's findings.

An Evaluation of Vaneless Diffuser Modelling Methods as a Means of Improving the Off-Design Performance Prediction of Centrifugal Compressors

An evaluation of existing 1-D vaneless diffuser design tools in the context of improving the off-design performance prediction of automotive turbocharger centrifugal compressors is described. A combination of extensive gas stand test data and single passage CFD simulations have been employed in order to permit evaluation of the different methods, allowing conclusions about the relative benefits and deficiencies of each of the different approaches to be determined. The vaneless diffuser itself has been isolated from the incumbent limitations in the accuracy of 1-D impeller modelling tools through development of a method to fully specify impeller exit conditions (in terms of mean quantities) using only standard test stand data with additional interstage static pressure measurements at the entrance to the diffuser. This method allowed a direct comparison between the test data and 1-D methods through sharing common inputs, thus achieving the aim of diffuser isolation.

Crucial to the accuracy of determining the performance of each of the vaneless diffuser configurations was the ability to quantify the presence and extent of the spanwise aerodynamic blockage present at the diffuser inlet section. A method to evaluate this critical parameter using CFD data is described herein, along with a correlation for blockage related to a new diffuser inlet flow parameter ⚡, equal to the quotient of the local flow coefficient and impeller tip speed Mach number. The resulting correlation permitted the variation of blockage with operating condition to be captured.

Maternal Risk Anxiety in Belfast: Claims, Evaluations, Responses

This paper considers the social logic of maternal anxiety about risks posed to children in segregated, post-conflict neighbourhoods. Focusing on qualitative research with mothers in Belfast’s impoverished and divided inner city, the paper draws on the interactionist perspective in the sociology of emotions to explore the ways in which maternal anxiety drives claims for recognition of good mothering, through orientations to these neighbourhoods. Drawing on Hirschman’s model of exit, loyalty and voice types of situated action, the paper examines the relationship between maternal risk anxiety and evaluations of neighbourhood safety. In arguing that emotions are important aspects of claims for social recognition, the paper demonstrates that anxiety provokes efforts to claim status, in this context through the explicit affirmation of non-sectarian mothering.

Sequential treatment with flavopiridol synergistically enhances pyrrolo-1,5-benzoxazepine-induced apoptosis in human chronic myeloid leukaemia cells including those resistant to imatinib treatment

The Bcr-Abl kinase inhibitor, imatinib mesylate, is the front line treatment for chronic myeloid leukaemia (CML), but the emergence of imatinib resistance has led to the search for alternative drug treatments and the examination of combination therapies to overcome imatinib resistance. The pro-apoptotic PBOX compounds are a recently developed novel series of microtubule targeting agents (MTAs) that depolymerise tubulin. Recent data demonstrating enhanced MTA-induced tumour cell apoptosis upon combination with the cyclin dependent kinase (CDK)-1 inhibitor flavopiridol prompted us to examine whether this compound could similarly enhance the effect of the PBOX compounds. We thus characterised the apoptotic and cell cycle events associated with combination therapy of the PBOX compounds and flavopiridol and results showed a sequence dependent, synergistic enhancement of apoptosis in CML cells including those expressing the imatinib-resistant T315I mutant. Flavopiridol reduced the number of polyploid cells formed in response to PBOX treatment but only to a small extent, suggesting that inhibition of endoreplication was unlikely to play a major role in the mechanism by which flavopiridol synergistically enhanced PBOX-induced apoptosis. The addition of flavopiridol following PBOX-6 treatment did however result in an accelerated exit from the G2/M transition accompanied by an enhanced downregulation and deactivation of the CDK1/cyclin B1 complex and an enhanced degradation of the inhibitor of apoptosis protein (IAP) survivin. In conclusion, results from this study highlight the potential of these novel series of PBOX compounds, alone or in sequential combination with flavopiridol, as an effective therapy against CML.

TAP Reactor Development and Application in the Kinetic Characterization of Catalysts for Heterogeneously Catalyzed Gas Phase Reactions

This manuscript describes the application and further development of the TAP technique in kinetic characterization of heterogeneous catalysis. The major application of TAP systems is to study mechanisms, kinetics and transport phenomena in heterogeneous catalysis, all of which is made possible by the sub-millisecond time resolution. Furthermore, the kinetic information obtained can be used to gain an insight into the mechanism occurring over the catalyst system. This is advantageous as heterogeneous catalysts with an improved efficiency can be developed as a result. TAP kinetic studies are carried out at low pressure (~1x10-7 mbar) and TAP pulses are sufficiently small (1013-1015 molecules) so as to maintain this low pressure. The use of a small number of molecules in comparison to the total number of active sites means the state of the catalyst remains relatively unchanged. The use of the low intensity pulses also makes the pressure gradient negligible and so allows the TAP reactor system to operate in the Knudsen Diffusion regime, where gas-gas reactions are eliminated. Hence only gas-catalyst reactions are investigated and, by the use of moment analysis of observed exit flow, rate constants of elementary steps of the reaction can be obtained.

In this manuscript, two attempts to further the TAP technique are reported. Firstly, the work undertaken at QUB to attempt to control the number of molecules of condensable reagents that can be pulsed during a TAP pulse experiment is disclosed. Secondly, a collaborative project with SAI Ltd Manchester is discussed in a separate chapter, where technical details and validation of a customised time of flight mass spectrometer (ToF MS) for the QUB TAP-1 system are reported. A collaborative project with Cardiff Catalysis Institute focusing on the study of CO oxidation over hopcalite catalysts is also reported. The analysis of the experimental results has provided an insight into the possible mechanism of the oxidation of CO over these catalysts. A correction function has also been derived which accounts for the adsorption of reactant molecules over inert materials that are used for the reactor packing in TAP experiments. This function was then applied to the selective reduction of O2 in a H2 rich ethene feed, so that more accurate TAP moment based analysis could be conducted.

Stochastic analysis of seepage under water-retaining structures

This paper investigated the problem of confined flow under dams and water retaining structuresusing stochastic modelling. The approach advocated in the study combined a finite elementsmethod based on the equation governing the dynamics of incompressible fluid flow through aporous medium with a random field generator that generates random hydraulic conductivity basedon lognormal probability distribution. The resulting model was then used to analyse confined flowunder a hydraulic structure. Cases for a structure provided with cutoff wall and when the wall didnot exist were both tested. Various statistical parameters that reflected different degrees ofheterogeneity were examined and the changes in the mean seepage flow, the mean uplift forceand the mean exit gradient observed under the structure were analysed. Results reveal that underheterogeneous conditions, the reduction made by the sheetpile in the uplift force and exit hydraulicgradient may be underestimated when deterministic solutions are used.

Single nucleotide polymorphisms in the APCS gene influence geographic atrophy secondary to VEGF inhibition therapy in neovascular macular degeneration.

Introduction: Age-related macular degeneration (AMD) is a leading cause of vision loss in the elderly mostly due to the development of neovascular AMD (nAMD) or geographic atrophy (GA). Intravitreal injections of anti-vascular endothelial growth factor (VEGF) agents are an effective therapeutic option for nAMD. Following anti-VEGF treatments, increased atrophy of the retinal pigment epithelium (RPE) and choriocapillaries that resembles GA has been reported. We sought to evaluate the underlying genetic influences that may contribute to this process. Methods: We selected 68 single nucleotide polymorphisms (SNPs) from genes previously identified as susceptibility factors in AMD, along with 43 SNPs from genes encoding the VEGF protein and its cognate receptors as this pathway is targeted by treatment. We enrolled 467 consecutive patients (Feb 2009 to October 2011) with nAMD who received anti-VEGF therapy. The acutely presenting eye was designated as the study eye and retinal tomograms graded for macular atrophy at study exit. Statistical analysis was performed using PLINK to identify SNPs with a P value < 0.01. Logistic regression models with macular atrophy as dependent variable were fitted with age, gender, smoking status, common genetic risk factors and the identified SNPs as explanatory variables. Results: Grading for macular atrophy was available in 304 study eyes and 70% (214) were classified as showing macular atrophy. In the unadjusted analysis we observed significant associations between macular atrophy and two independent SNPs in the APCS gene: rs6695377: odds ratio (OR) = 1.98; 95% confidence intervals (CI): 1.23, 3.19; P = 0.004; rs1446965: OR = 2.49, CI: 1.29, 4.82; P = 0.006 and these associations remained significant after adjustment for covariates. Conclusions: VEGF is a mitogen and growth factor for choroidal blood vessels and the RPE and its inhibition could lead to atrophy of these key tissues. Anti-VEGF treatment can interfere with ocular vascular maintenance and may be associated with RPE and choroidal atrophy. As such, these medications, which block the effects of VEGF, may influence the development of GA. The top associated SNPs are found in the APCS gene, a highly conserved glycoprotein that encodes Serum amyloid P (SAP) which opsonizes apoptotic cells. SAP can bind to and activate complement components via binding to C1q, a mechanism by which SAP may remove cellular debris, affecting regulation of the three complement pathways.

Extent and mechanism of phase separation during the extrusion of calcium phosphate pastes

The aim of this study was to increase understanding of the mechanism and dominant drivers influencing phase separation during ram extrusion of calcium phosphate (CaP) paste for orthopaedic applications. The liquid content of extrudate was determined, and the flow of liquid and powder phases within the syringe barrel during extrusion were observed, subject to various extrusion parameters. Increasing the initial liquid-to-powder mass ratio, LPR, (0.4-0.45), plunger rate (5-20 mm/min), and tapering the barrel exit (45°-90°) significantly reduced the extent of phase separation. Phase separation values ranged from (6.22 ± 0.69 to 18.94 ± 0.69 %). However altering needle geometry had no significant effect on phase separation. From powder tracing and liquid content determination, static zones of powder and a non-uniform liquid distribution was observed within the barrel. Measurements of extrudate and paste LPR within the barrel indicated that extrudate LPR remained constant during extrusion, while LPR of paste within the barrel decreased steadily. These observations indicate the mechanism of phase separation was located within the syringe barrel. Therefore phase separation can be attributed to either; (1) the liquid being forced downstream by an increase in pore pressure as a result of powder consolidation due to the pressure exerted by the plunger or (2) the liquid being drawn from paste within the barrel, due to suction, driven by dilation of the solids matrix at the barrel exit. Differentiating between these two mechanisms is difficult; however results obtained suggest that suction is the dominant phase separation mechanism occurring during extrusion of CaP paste.

Evolution and Enabling Capabilities of Spatially Resolved Techniques for the Characterization of Heterogeneously Catalyzed Reactions

The development and optimization of catalysts and catalytic processes requires knowledge of reaction kinetics and mechanisms. In traditional catalyst kinetic characterization, the gas composition is known at the inlet, and the exit flow is measured to determine changes in concentration. As such, the progression of the chemistry within the catalyst is not known. Technological advances in electromagnetic and physical probes have made visualizing the evolution of the chemistry within catalyst samples a reality, as part of a methodology commonly known as spatial resolution. Herein, we discuss and evaluate the development of spatially resolved techniques, including the evolutions and achievements of this growing area of catalytic research. The impact of such techniques is discussed in terms of the invasiveness of physical probes on catalytic systems, as well as how experimentally obtained spatial profiles can be used in conjunction with kinetic modelling. Furthermore, some aims and aspirations for further evolution of spatially resolved techniques are considered.

Kinetics of the photocatalysed oxidation of NO in the ISO 22197 reactor

The photocatalytic reactor described in the NOx removal ISO 22197-1:2007 is used to study the kinetics of the process, using a film of P25 TiO2 which has either been conventionally pre-irradiated in a stream of air, or unconventionally in a stream of NO (1 ppmv). In the former case it is shown that the system does not achieve steady state exit levels of NO, probably due to the gradual accumulation of HNO3 on the surface of the photocatalyst. The NO-preconditioned TiO2 film demonstrated excellent steady-state levels when monitored as a function of NO concentration, [NO] and UV irradiance, ρ. However, in this case the photocatalytic reaction under study is NOT NOx removal, but the conversion of NO to NO2. It is shown that the kinetics of this steady state process fit very well to a kinetic expression based on a disrupted adsorption reaction mechanism, which has also been used by others to fit their observed (non-steady state) kinetics for NOx removal on conventionally-(air) preconditioned films of P25. The appropriateness of this model for either system is questioned, since in both systems the kinetics appear to have a significant mass transport element. These findings suggest that mass transport and non-steady-state kinetics are likely to be significant features for most active photocatalytic samples, where the %NO conversion is >7%, and so limits the usefulness of the NOx removal ISO 22197-1:2007.