Ethnic disparaties in the prevalence of overweight and obesity among women and children in high income countries : the case for Aftican migrant women and children

PhD ThesisExcess body weight in women of child-bearing age can have severe consequences for maternal and child health, including reduced fertility, pregnancy complications, an increased risk of child obesity and increased susceptibility to non-communicable diseases. Black women and children in high-income countries (HICs) have a disproportionately higher prevalence of overweight and obesity compared to other ethnic groups. However, there is a lack of evidence on the weight status of African migrant women and children living in HICs, and on these women’s weight perceptions and perceived risks of overweight and obesity. In the first phase of this thesis, I used systematic review, meta-analysis and framework synthesis methods to explore the weight status of African migrant women and children living in HICs, and the dietary and physical activity (PA) behaviours of African migrant women. Metaanalyses results showed that African migrant women had higher body mass index (BMI) (weighted mean difference (WMD)=1.95 Kg/m2, 95%CI 1.16–2.75) and higher odds of overweight (OR=2.45, 95%CI 1.65–3.63), obesity (OR=2.09, 95%CI 1.41–3.12) and combined overweight/obesity (OR=2.09, 95%CI 1.41–3.12) compared to non-African women from HICs. Children of African migrant women also had higher mean birthweights (WMD=48.71g, 95%CI 4.19g–93.24g), higher odds of overweight (OR=1.50, 95%CI 1.00– 2.24), obesity (OR=2.28, 95%CI 1.37–3.78), combined overweight/obesity (OR=2.08, 95%CI 1.40–3.11) and macrosomia (OR=1.83, 95%CI 1.77–1.89), and lower odds of low birthweight (OR=1.06, 95%CI 0.56–2.02) compared to children of non-African women. Risks of overweight and obesity were higher for women and children from North Africa, while data were lacking for sub-Saharan Africa. African migrant women had bicultural dietary patterns, inadequate intakes of iron, folate, and calcium, excessive sodium intakes, and reduced PA levels. There were data gaps on potential confounders that may influence maternal and child weight status, associations between maternal characteristics and child weight outcomes, and weight-related behaviours of pregnant African migrant women. In the second phase, I explored the weight perceptions of African migrant women living in the UK, their perceived risks of overweight and obesity to themselves and their children, and the sociocultural and migration-related influences of these. Interviews conducted with 23 African migrant women from Nigeria, Ghana and Cameroon were analysed through thematic analysis. Key themes identified were: ‘we are not at risk’, ‘bigger is better’, acculturation, ‘a child cannot be too fat’ and infant feeding as a balancing act. The women’s perceptions were influenced by their understandings and lay interpretations of body weight terms, which differed from mainstream knowledge. Perceived risk factors for obesity included: diet, genetics, childbearing and living the ‘easy life’ in the UK. PA was mostly interpreted as sport or exercise and was not an intrinsic part of their culture. Post-migration changes in weight perceptions included increased knowledge of healthy weight-related behaviours, awareness of unhealthy cultural practices and preference for smaller body sizes (for themselves but not their children). Pregnancy was associated with heightened weight-awareness, while preconception weight was believed to have no influence on women’s health or pregnancy. Midwives and relatives were useful information sources for pregnancy weight, and challenges with weight management in pregnancy included families encouraging weight gain; food cravings; unhealthy food in the UK and unfamiliar dietary advice from midwives. Women tended to disregard weight-related advice from health care providers, while valuing advice from friends and family. This thesis identifies African migrant women and children as high-risk groups for overweight and obesity, and highlights the role of migration and socio-cultural influences on their weight status, behaviours and perceptions. There is a need for culturally-tailored interventions to support weight management in this population, especially taking into account their multicultural identities. Further research and interventions addressing the risk factors and areas of need identified could help prevent further increases in obesity, and contribute towards narrowing the inequality gaps in health outcomes among migrant populations in HICs

Determinants of the gut microbiota development in piglets and its relationship to performance

PhD ThesisThe role of the microbiota in host health and metabolic phenotype is of increasing interest, with perturbations to the microbiota in early life influencing long term health conditions. The aim of this thesis was to establish factors affecting the neonatal piglet microbiota development and to identify microbiota markers associated with superior piglet growth. Longitudinal analysis revealed that, whilst piglet age was the main determinant of microbiota development over the first 8 weeks of life, differences in faecal microbiota richness and genera abundance were associated with piglet birthweight. The abundance of several identified genera was higher in piglets with superior growth rates during early life. The sow is an important source of microbiota seeding to neonatal piglets. Sow faecal microbiota changed significantly during the periparturient period and differed between parities, with primiparous sows exhibiting a lower microbiota diversity than multiparous sows. Early life piglet microbiota community composition was more like the maternal areolar skin microbiota immediately after birth but became increasingly similar to the maternal faecal microbiota with time. In a reciprocal cross-fostering model between primiparous and multiparous sows, a litter specific neonatal piglet microbiota existed for the first three days of life, with siblings separated by cross-fostering retaining a more similar microbiota composition than non-siblings in the same litter. Non-fostered primiparous progeny had lower neonatal microbiota diversity and pre-weaning growth, whilst cross-fostered piglets developed a more diverse neonatal microbiota. Administration during the neonatal period of an autogenous Enterococcus faecium strain, previously associated with superior piglet growth was unsuccessful in improving pre- or postweaning performance, but reduced diarrhoea occurrence. In conclusion, early life microbiota markers associated with birthweight and growth have been identified. Sow microbiota sources, sow parity and standard management practices, such as cross-fostering influence piglet microbiota development. Exploiting this knowledge could help to design management strategies aimed at improving piglet performance through microbiota manipulation.Institute for Agri-Food Research and Innovation, a joint venture between Newcastle University and Fera Science Lt

A child-centred approach in human heritable genome editing

Ph. D. Thesis.The core feature of human heritable genome editing (“HGE”) is that any modification made on the germ cells (sperms or eggs) or early human embryos is likely to be passed down to subsequent generations. This feature makes the use of this technology highly controversial. Thus, there is a need to adopt a suitable approach to consider future children who are going to live the consequences of this technology. Taking a child-centred perspective, this thesis explores two main concerns: first, whether, and to what extent, the act of HGE is ethically acceptable; and second, how should HGE be regulated if it is deemed ethically acceptable for reproductive use. More specifically, it examines how a child-centred approach should be adopted in answering these questions. This thesis first examines four child-related arguments commonly raised in the existing HGE debate, including the non-identity problem, the open future argument, the purported right to non-modified genomes, and the proposed long-term follow up system for the resulting children. It argues that the existing arguments and proposal have failed to appropriately consider (future) children’s interests mainly because there is (1) a lack of solid theoretical framework to justify the recommendation commonly made for a health-related use of HGE, and (2) a lack of detailed analysis on an important but often overlooked concept in the HGE debate, that is the concept of “identity”. In order to fill these gaps, this thesis explores the capability approach and argues that Jennifer Ruger’s health capability paradigm provides a good philosophical framework in understanding why “health capabilities” can justify and more importantly, also limit the health-related use of the technology. Additionally, this thesis analyses the concepts of “identity” and argues for a multi-faceted understanding of “identity” with narrative identity to be given the greatest weight in the ethico-legal considerations of HGE

Developing English as a Foreign Language students’ critical thinking during the process of collaborative writing

Integrated PhDBased on a premise that critical thinking (CT) can be taught and assessed (Mason, 2008; Mehta and Al-Mahrooqi, 2015), this study examined the Critical Thinking (CT) application of English as Foreign Language (EFL) students. It focused, in particular, on the impact of mutual interaction with CT instruction during Collaborative Writing (CW) activities. In order to promote EFL university students’ understanding and application of CT, a collaborative learning environment and explicit teaching of CT were encouraged in EFL classes (Todd and Hudson, 2007; Jones, 2008; Lin, 2014). Within the CT instruction environment, this study integrated CW practices with CT pedagogy to encourage negotiation and collaborative interaction and to stimulate EFL students’ CT (Lowry et al., 2004; Storch, 2013; Storch, 2016). An eight-week CW intervention integrated with CT instruction was conducted for 24 EFL students in a Chinese university. Here, a mixed methods approach was employed, including pre- and post- tests of student argumentative writing and CT, classroom observation of peer interaction and CT application, and semi-structured interviews to investigate participant attitudes to CW and CT. In addition to examining writing and CT test outcomes after the intervention, this study observed interactions to explore participants’ CT development during the CW process. In this regard, the dyadic interaction patterns proposed by Storch (2002; 2013) and the taxonomy of language functions adapted from Li and Kim (2016) were used to establish a comprehensive analytical framework. The findings demonstrated that participants gradually developed a collaborative interaction pattern with high levels of mutuality and equality in task contribution. Through this, they produced more CT-related language functions, such as arguing and justifying, at the end of the eight-week intervention. Results from pre- and post- tests and participant interview responses also suggested that embedding CT into the CW process could improve participants’ CT. As such, these findings contribute to an understanding of EFL student CT and learning processes within EFL teaching, and it can help to inform the design of EFL classes

Determining the efficacy of a usage-based language intervention in the early years : a non-randomised pilot stud

PhD ThesisIntroduction Language skills are crucial for positive social, emotional, academic and economic outcomes across the lifespan. Whilst most children acquire language relatively easily, a number of children experience difficulties. Early intervention can mitigate the risks associated with poor language skills, and the importance of evidence-based intervention is widely recognised by Speech and Language Therapists. Despite this, there are few robustly evaluated language interventions for young children. Building Early Sentences Therapy (BEST) is a complex language intervention designed to support children to understand and produce two, three and four clause-element sentences (McKean et al., 2013). This thesis presents a non-randomised quasi-experimental study of BEST with sign, BEST without sign and Treatment as Usual with four key goals: 1) to evaluate the efficacy of BEST, 2) to assess the use of sign as an ‘active ingredient’, 3) determine the effect sizes from goals 1 and 2, and 4) to inform further evaluation. Methods Schools were assigned to three treatment arms matched with respect to classroom oral language environment and socioeconomic status. Participants were 3;5-4;5-year-old children with expressive, receptive or mixed language difficulties below the 16th centile. The intervention was 16 sessions of BEST with or BEST without sign. The TAU group received their usual classroom provision. Children’s outcomes on production, comprehension, content and morphology on targeted and non targeted language structures were measured. Results Visual trends showed improvement for children receiving BEST. There was evidence for the efficacy of BEST compared to TAU for Production, Content and Morphology outcomes. There was also evidence that BEST with Sign improved outcomes further for Production and Sentence Morphology outcomes. Content Analysis of teacher feedback led to the generation of recommendations for future studies evaluating BEST. Discussion Children receiving BEST make progress with production, content and morphology outcomes. The role of sign in further supporting progress is positively indicated. A further trial of BEST is warranted

Professionals working with children and families who have had adverse childhood experiences

D. Ed. App. Psy. ThesisUK professional networks and services have begun accommodating into their practices what is known about Adverse Childhood Experiences (ACEs). Including international research efforts, there is growing interest and awareness regarding their health and social impact. However, debate continues regarding the potentially reductionist and deterministic nature of the ACEs model, causing concern given growing public attention. A systematic literature review was conducted exploring education- and community-based interventions aiming to mitigate ACEs’ impact. The best available evidence was collated, synthesising eight empirical papers of varying research design and context. Papers were critically analysed, and results synthesised using their assessed quality and strength of findings. The findings mirror the depth and complexity of the ACEs model. Themes and differences across intervention content and impact are identified and discussed. Implications for the interpretation and use of the model are discussed, especially within education and connected services. Arising from this literature exploration, an action research project took place in a primary school. Collaborating with a staff working party, this explored the way in which Continuing Professional Development (CPD) about ACEs could be facilitated in school. Group data were analysed using an abbreviated constructionist grounded theory approach and findings are situated alongside Hope Theory. Further discussion focuses on the links between the two pieces of research and the personal decisions made regarding their significance. Ontological and theoretical underpinnings are explored, along with the impact of the complex positioning of the researcher when using an action research process and engaging in constructionist grounded theory analysis. Attention is also given to ethical issues

Fundamental Understanding of Turbulent Combustion in Droplet-Laden Mixtures Using Direct Numerical Simulations

PhD ThesisThe flame propagation in droplet-laden mixtures is of considerable importance in automotive engines, gas turbines, and accidental explosions. Despite the practical importance of turbulent combustion of droplet-laden mixtures, it remains one of the most challenging topics in thermo-fluid mechanics due to the involvement of complex interactions of evaporation, heat and mass transfer, fluid dynamics, and combustion thermochemistry. Thorough knowledge of these interactions, which occur over a wide range of scales, is necessary for fundamental understanding and modelling of turbulent spray flames. In this thesis, three dimensional compressible Direct Numerical Simulations (DNS) of spherically expanding and V-shaped flames propagating in droplet mists are considered for a fundamental physical understanding of the flame structure and flame speed statistics in turbulent spray flames. Simulations with modified single-step Arrhenius type chemical mechanism have been conducted for a range of different droplet diameters, overall equivalence ratios, and turbulence intensities. The influence of liquid droplets has been investigated by comparing the statistics for spray flames to those for the corresponding gaseous premixed spherically expanding flames with statistically similar initial turbulent flow conditions. It has been found that flame-droplet interaction promotes dropletinduced flame wrinkling for laminar flame kernels, and this strengthens with increasing overall equivalence ratio and droplet diameter. However, the effects of droplet-induced flame wrinkling cannot be readily distinguished from flame wrinkling due to fluid motion for turbulent spherically expanding spray flames. The combustion has been found to take place predominantly under fuel-lean mode in comparison to the overall equivalence ratio for all droplet sizes and this tendency strengthens with increasing droplet diameter due to slow evaporation of large droplets. Furthermore, increasing turbulence intensities enhances the availability of fuel-lean mixture. The statistics of the Surface Density Function (SDF = magnitude of the reaction progress variable gradient) and the strain rates, which affect the behaviour of SDF have been analysed for spherically expanding spray flames. Flame thickening has been observed for large droplets and at high turbulence intensities due to the predominance of fuel-lean combustion. Droplet size and turbulence intensity significantly affect the behaviour of scalar gradients and the infinitesimal distance between non-material surfaces. The flame propagation behaviour in droplet-laden mixtures has been analysed in terms of the statistics of density-weighted dis- placement and consumption speeds. Flame topologies associated with flame self-interaction events have been discussed along with the small-scale scalar geometries of flame isosurfaces. The presence of droplets, turbulence intensity and droplet diameter have been found to considerably alter the distributions of flame topologies. Additionally, flame-droplet interactions have been investigated in detail based on the source terms associated with two-phase coupling arising from droplet evaporation in various gaseous carrier phase transport equations and the modelling implications of the statistical behaviour of flame-droplet interactions have been addressed. Furthermore, hypothetical inertialess droplet motion is considered to identify the influence of droplet inertia on the combustion characteristics and the evolution of the flame surface area. The number density of droplets within the flame is greater for the inertial droplet cases than the corresponding inertialess droplet cases and this leads to higher availability of obtaining stoichiometric mixture in the flame. Finally, a comparison between the spherically expanding and V-shaped spray flames reveals that flame curvature, density-weighted displacement speed, and consumption speed varies considerably with droplet diameter in the case of spherically expanding spray flame cases, whereas the effects of droplet diameter are relatively weaker in V-flames. Simulations of V-shaped flames propagating in droplet mists for different mean inflow velocities indicate that reacting mixture composition significantly varies with the mean inflow velocity which also plays an important role in determining the flame structure and burning rate statistics

Assessment and correction of endogeneity problems in discrete choice models

PhD ThesisThe term endogeneity is used when there is a correlation between one or more observed explanatory variables (independent variables) and the error term of an econometric model. Endogeneity is considered a practically inevitable phenomenon in econometric modelling, as there are many potential causes behind it: omitted variables, measurement or specification errors, simultaneous estimation and self-selection. The problem is that it may give rise to inconsistent parameter estimates, and if its effects are not considered when estimating a model, the analyst may come to wrong forecasts and conclusions. Correcting for endogeneity has been widely addressed in the linear models (LM) literature, but LM have a limited scope in certain areas. This is particularly the case in planning and social evaluation of transport projects, where Discrete Choice Models (DCM), which are highly non-linear, play a fundamental role. Unfortunately, DCM are not often corrected for endogeneity, so a gap has been identified in the state of knowledge that this thesis intends to close. Thus, the general aim of this Ph.D. dissertation is to develop a set of guidelines that allow for the assessment and correction of endogeneity problems in DCM. We establish conclusions of a theoretical, empirical and methodological nature. In the first instance, it is desired to determine adequate instrumental variables for endogeneity correction in transport modelling and measure the impact of this correction on strategic modal split models. We can reduce the errors associated with the estimation of DCM, improve its forecasting capabilities, and achieve consistent parameters resulting in corrected estimates of model valuation measures, such as the subjective value of time (SVT). Furthermore, we formulate an empirical methodology, supported by Monte Carlo simulation, to predict using DCM corrected for endogeneity with a new and more adequate version of the CF method. We also define guidelines to clarify under what conditions discrete indicators work (or not) when DCM are corrected for endogeneity using the MIS method. Finally, we structure a methodology to detect weak DCM instruments based on what has been proposed for linear model

Characterisation and structural biology of protein arginine methyltransferases

PhD ThesisPost-translational and epigenetic modifications of proteins and nucleic acids are known to play major roles in influencing cell fate. Enzymes that catalyse modifications such as phosphorylation, acetylation and methylation have been identified as promising drug targets. Protein methyltransferase 2 (PRMT2) and Coactivator-associated arginine methyltransferase 1 (CARM1) belong to the class of Type 1 PRMTs which catalyse the asymmetric dimethylation of substrate arginine residues. CARM1 has been shown to be overexpressed in different cancer types including breast and prostate cancer. PRMT2 has been identified as a potential target for oncology with reported links to androgen receptor signalling, NF-κB signalling and induction of apoptosis. However, selective chemical probes that could be used as tools for target validation and which could potentially be a starting point for drug discovery are still missing. The work presented here aims to identify selective CARM1 and PRMT2 inhibitors that target the cofactor- and substrate-binding sites. Crystal structures of mouse PRMT2 in the apo-state and in complex with Sinefungin are presented. Crystal structures of the catalytic domain of CARM1 in complex with the cofactor S-adenosyl Lhomocysteine (SAH) and different small molecule inhibitors were also determined. Surface plasmon resonance was used to characterise inhibitor binding to CARM1 and identify structure-activity relationships. To further map the CARM1 active site, ligand soaks of CARM1 with a library of small fragments called FragLites were performed. These small fragments can more readily find potential binding pockets than larger more drug-like inhibitors. A direct and label-free mass spectrometry-based assay was developed to measure CARM1 activity and its inhibition. Together these findings can be used to further develop inhibitors that target the PRMT family. These inhibitors will be useful tools to investigate the biology of PRMT2 and CARM1 and to understand their biological role in cancer

Investigation into Non-Aqueous Aluminium-ion Battery Electrolyte and Cathode Materials for Enhanced Power and Capacity

PhD ThesisEnergy storage is one of the most important resources in today’s society. Developing this resource to be more efficient and sustainable is one of the biggest challenges to overcome. For decades, lithium has been at the forefront of energy storage, powering our technology from mobile phones to electric vehicles. The dwindling amount of available lithium left in the world signals that it’s time for the next battery material. Aluminium is not only substantially more abundant across the world, making it cheaper with a lower carbon footprint, but due to its trivalency it possesses a larger capacity than monovalent lithium which could result in smaller, higher capacity and more affordable batteries. This work investigated different electrolyte compositions of aluminium-ion batteries (AIB), a eutectic melt of 1-ethyl-3-methylimidazolium chloride with AlCl3 and its impact on electrochemical stability, anode and cathode performance, and battery coulombic efficiency, degradation, and capacity. The anodic limit of the electrolyte increased with increasing AlCl3 content due to formation of Al2Cl7 - species. Electrolyte degradation studies revealed electrolyte oxidation produces chlorine gas which was detected as HCl. Several carbon-based and metal oxide cathode materials were investigated for AIBs. Cathode potential, mechanism of reaction, coulombic efficiency, specific capacity, and degradation rates were recorded. Charged and discharged cathode material characterisations were carried out using XRD, STM, and Raman spectroscopic techniques. The dominant two mechanisms were found to be chloroaluminate intercalation or electro-adsorption. Cell tests were performed to study the interplay between the Al metal anode, cathodes, and varying electrolyte compositions on charge/discharge. Battery performance was assessed using key performance indicators: specific capacity, specific energy, and coulombic efficiency. Carbonbased materials displayed the greatest performance with graphite giving a specific capacity of 295 mAhg-1 with an energy density of 500 Whkg-1 . A hybrid lithium-aluminium cell using an NMC 811 positive electrode resulted in a capacity of 58 mAhg-1