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Human Immunodeficiency Virus (HIV) infection is a global public health priority. An effective HIV-1 vaccine strategy must overcome the enormous genetic diversity generated by the virus while inducing potent, long lasting immune responses. In this thesis, virus-specific cellular immune responses directed towards HIV conserved regions were evaluated using a validated IFN-γ enzyme-linked immunospot (ELISpot) assay and two sets of peptide panels based upon HIV-1 vaccine candidates. One panel was based on the 14 of the most highly conserved (HIVconsv – 806 amino acids) regions of the HIV-1 proteome and was designed to provide extensive coverage of subtypes A, B, C and D. The second panel represents Gag, Reverse Transcriptase (RT), Integrase (INT), Nef and Envelope sequences derived from a consensus subtype A reference (GRIN/Env). The purpose of this study was to examine the extent of T cell responses to HIV-1 epitopes elicited at different stages of HIV-1 infection and in vaccinees. Individuals infected with HIV-1 subtypes (A, B, C and D) from the UK, Rwanda, Uganda, and Zambia representing a wide range of genetic backgrounds were tested using a HIVconsv peptide matrix and GRIN pools. CD8 responses were identified across Gag, RT and INT and there was no apparent subtype specific bias in terms of recognition of both peptide panels (HIVconsv and GRIN/Env). GRIN appeared to be more antigenic because GRIN incorporated both conserved and variable epitopes compared to HIVconsv panel that only comprised conserved peptide sequences. Furthermore, there was no association between IFN-γ T cell responses and control of viraemia in early infection between viraemic controllers (VC) and viraemic progressors (VP). However, VC appeared to be slightly more polyfunctional than VP. Viral inhibition assay (VIA) employed to assess the vaccine specific responses demonstrated that conserved regions of the HIV-1 proteome could result in an increased ability to inhibit a panel of HIV-1 isolates in vitro. Although detection of a CD8+ T cell response against a particular epitope does not necessarily translate to protection, the conserved nature of HIV-1 epitopes suggests that these domains are immunogenic and might be important for viral function. Thus, these data support the inclusion of conserved sequences in any future vaccine candidate.

Group work is defined as an instructional strategy to encourage social interaction among pupils. Pupils are more likely to work in groups to perform their daily based learning activities in most of primary classrooms in England. Pupils sit around the table and apparently work in groups. However, putting pupils in groups does not always guarantee that they interact and communicate with one other to fulfil the theoretical expectations advocated in constructivists’ theories of learning. There can be various factors related to pupils and their context which can affect their interactions to make group work successful in any classroom. This study was aimed to explore the nature of pupils’ interaction and their perceptions of working with others during their routinely organised group work in a state primary school in England. The primarily focus of the study was to analyse the nature of pupils’ interactions under various grouping structures organised by the class teacher, to explore pupils’ perceptions about group work while identifying various contextual, social and cultural factors which can influence pupils’ interactions and their perceptions of group work. In this small- scale qualitative study, I used naturalistic participant observation to observe pupils’ interactions during their routinely organised group work in one primary classroom. I also used informal conversational interviews to explore pupils’ perceptions about their experiences of working with others in groups. Both the class and support teachers of the observed class were also involved in the research to gain their perspectives on the organisation of group work. The qualitative data gathered in form of pupils’ conversations, actions, verbal and non-verbal interactions and dialogues was analysed by using first thematic and later on through discourse analytical approaches. The findings of my research are drawn on the ecological model of Bronfenbrenner which revealed that the pupils adopt dynamic, situational, cooperative and non-cooperative interactions towards their peers during their group work. They participated in task-related discussions and remained cooperative by showing positive social attitudes of helping and encouraging others. They showed non- cooperative interactions by being competitive and showed mistrust towards their peers. The pupils also exhibited gender biased attitudes which influenced their decisions of being cooperative or non- cooperative towards a particular peer. The use of ecological model helped me to illicit that pupils were influenced from their immediate and wider contexts while interacting with their peers. In the immediate setting of the classroom, pupils were dependent on the group structure, teaching instructions and learning tasks to work as a group or as an individual. Similarly, pupils were dependent on and were influenced by their wider contexts (i.e. interpretations of the national curriculum guidance, pupils’ socio-cultural backgrounds and community influences) to adopt competitive and gender biased interactions. In the light of these findings, I suggest that the success of social interactions among pupils is dependent on the context which is interwoven by various internal organisational, social, educational as well as cultural layers. These influences coming from the internal and external contextual layers cannot be ignored in any educational research aiming to investigate classroom practices or pupils’ learning experiences inside the state primary schools.

The aim of this thesis was to optimise a method for the unequivocal identification of aluminium (Al) in human brain tissue. The second aim was to devise a protocol that was simple to implement and as such could be carried out without the need for sophisticated and expensive instrumentation. The presence of Al in brain tissue is linked to a number of neurodegenerative diseases and is the cause of dialysis encephalopathy. Therefore, it is of paramount importance to be able to both measure and locate Al in complex milieu such as human brain tissues. Multiple methods have been proposed for the identification of Al in biota including human tissues. However, there have been limitations within these methods such as specificity, selectivity and limits of detection. Herein, transversely heated graphite atomic absorption spectrometry (TH GFAAS) and fluorescence microscopy were used to measure and locate Al within brain tissues of donors who died with a diagnosis of familial Alzheimer’s disease (fAD) or autism. A fluorimetric method was optimised using surrogate human tissues so as not to use actual human brain tissue for method development. The results identified lumogallion as a selective and specific fluorophore for the identification of Al. The complex of lumogallion with Al produced characteristic orange fluorescence, which was specific to Al and for which there were no interferences from other metals which could be present in tissue, e.g. calcium, magnesium, iron. Congo red was used to identify the presence of amyloid, which was confirmed as being in a  sheet confirmation by the presence of apple-green birefringence. Lumogallion was used successfully and unequivocally to demonstrate the presence and location of Al within all four main lobes of brain tissue donated by individuals with a diagnosis of fAD. The combination of TH GFAAS and fluorescence microscopy was used to provide the first evidence of Al in the brains of individuals with fAD and these results should be considered in the light of the suggested role of Al in all forms of Alzheimer’s disease.

Introduction Oral delivery of proteins faces numerous challenges due to their enzymatic susceptibility and instability in the gastrointestinal tract. In recent years, the polyelectrolyte complexes have been explored for their ability to complex protein and protect them against chemical and enzymatic degradation. However, most of the conventional binary polyelectrolyte complexes (PECs) are formed by polycations which are associated with toxicity and non-specific bio-interactions. The aim of this thesis was to prepare a series of ternary polyelectrolyte complexes (APECs) by introduction of a polyanion in the binary complexes to alleviate the aforementioned limitations. Method Eight non-insulin loaded ternary complexes (NIL APECs) were spontaneously formed upon mixing a polycation [polyallylamine (PAH), palmitoyl grafted-PAH (Pa2.5), dimethylamino-1-naphthalenesulfonyl grafted-PAH (Da10) or quaternised palmitoyl-PAH (QPa2.5)] with a polyanion [dextran sulphate (DS) or polyacrylic acid (PAA)] at 2:1 ratio, in the presence of ZnSO4 (4μM). A model protein i.e., insulin was added to a polycation, prior to addition of a polyanion and ZnSO4 to form eight insulin loaded (IL) APECs. PECs were used as a control to compare APECs. The complexes were characterised by dynamic light scattering (DLS) and transmission electron microscope (TEM). In vitro stability of the complexes was investigated at pH (1.2-7.4), temperature (25˚C, 37˚C and 45˚C) and ionic strength (NaCl-68mM, 103mM and 145mM). Insulin complexation efficiency was assessed by using bovine insulin ELISA assay kit. The in vitro cytotoxicity was investigated on CaCo2 and J774 cells by MTT (3-4,5 dimethyl thialzol2,5 diphenyl tetrazolium bromide) assay. All complexes were evaluated for their haemocompatibility by using haemolysis assay, oxidative stress by reactive oxygen species (ROS) assay and immunotoxicity by in vitro and in vivo cytokine generation assay. The potential of the uptake of complexes across CaCo2 cells was determined by flow cytometry and fluorescent microscopy. The underlying mechanism of transport of complexes was determined by TEER measurement, assessment of FITC-Dextran and insulin transport across CaCo2 cells. 15 Results NIL QPa2.5 APECs (except IL QPa2.5-DS) exhibited larger hydrodynamic sizes (228-468nm) than all other APECs, due to the presence of bulky quaternary ammonium moieties. QPa2.5 APECs exhibited lower insulin association efficiency (≤40%) than other APECs (≥55%) due to a competition between the polyanion and insulin for QPa2.5 leading to reduced association of insulin in the complexes. DS based APECs generally offered higher insulin association efficiency (≥75%) than PAA based APECs (≤55%) due to higher molecular weight (6-10kDa) of DS. In comparison to other complexes, Pa2.5 PECs and APECs were more stable at varying temperature, ionic strength and pH due to the presence of long palmitoyl alkyl chain (C16) which reduced the chain flexibility and provided stronger hydrophobic association. The cytotoxicity of polycations on CaCo2 and J774 cells is rated as PAH>Da10=Pa2.5>QPa2.5. The introduction of PAA in Pa2.5 and Da10 brought most significant improvement in IC50 i.e., 14 fold and 16 fold respectively on CaCo2 cells; 9.3 fold and 3.73 fold respectively on J774 cells. In comparison to other complexes, Da10 (8mgml-1) induced higher haemolytic activity (~37%) due to a higher hydrophobic load of 10 percent mole grafting of dansyl pendants. The entire range of APECs displayed ≤12% ROS generation by the CaCo2 cells. The degree of in vitro TNFα production (QPa2.5≥Da10≥Pa2.5=PAH) and in vitro IL-6 generation (QPa2.5≥Pa2.5=PAH≥Da10) by J774 cells established an inverse relationship of cytotoxicity with the cytokine generation. Similar to MTT data, the introduction of PAA in APECs brought more significant reduction in in vitro cytokine secretion than DS based APECs. Pa2.5-PAA brought the most significant reduction in both in vitro and in vivo cytokine generation. All the formulations were able to significantly reduce original TEER, however did not demonstrate appreciable paracellular permeation of a hydrophilic macromolecular tracer of paracellular transport i.e., FITC Dextran. The uptake study revealed internalisation of APECs predominantly by a transcellular route. Transcellular uptake of IL QPa2.5 (≤73%), IL QPa2.5-DS (67%) was higher than their NIL counterparts, whereas the uptake of NIL Pa2.5 (≤89%), NIL Pa2.5-PAA (42%) was higher than their IL counterparts. Conclusion In essence, amphiphilic APECs have shown polyanion dependent ability to reduce polycation associated toxicity and they are able to facilitate transcellular uptake of insulin across CaCo2 cells.

The dissertation aims to explore the supply and demand side determinant of child labour at macro, meso and micro level. At macro level it explores the effect of globalization (defined as openness to trade and inflow of foreign direct investment) and credit market imperfections on child labour. At meso level it explores the effect of labour market conditions on child labour. As the above two levels of analysis are mainly concerned with the demand for child labour, the micro level analysis explores the supply side determinant of child labour. At micro level this dissertation explores the effect of intrahousehold distribution of power on child related outcome. Specifically it explores the effect of mother’s decision making power on her child’s labour and schooling. The macro level analysis is based on cross country regression framework while meso and micro level analysis is based on the data from Pakistan. At macro level, this dissertation points out that trade openness and FDI inflow raise the standard of living in an economy thereby reducing child labour incidence. As the channel through which trade could affect child labour is by increasing income of the poor, credit market imperfection shows insignificant effect. At meso level, this dissertation points out that high adult wages in an area increase demand for child labour while presence of adult unemployed proportion in an area reduces demand for child labour. However, presence of unemployed adult in a house increases supply of child labour. Exports, on one hand, reduce supply of child labour by affecting the income of poor at macro level while on the other hand at meso level, subcontracting of production process to small informal sector increases demand for child labour. The informal sector being unprotected by law employs a high proportion of child labour. At micro level mother’s decision making power significantly decreases child labour supply and increases child schooling. The effect is significant in case of girls but not in case of boys. This study also shows that whether children work for generating income or as family helpers, mothers are equally concerned for their welfare. Their decision making power significantly reduces labour among children.

This study analyses the stories of young people, both male and female, from rural and economically weak backgrounds. Participants in the present study come from the province of Sindh, Pakistan, and Sindhi is their first language. The data consist of the narratives of their lives. They deal with their attitudes and behaviours, actions and struggles, hurdles and hardships, expectations and desires. The participants talked about their family, home, village, surroundings, socio-economic problems, etc. My participants struggled to make ends meet economically and worked hard to improve their social position and that of their families. This study tries to interpret the observations of the interviews in terms of the theories and categories of Pierre Bourdieu (cultural, social, and symbolic capital; habitus, field, symbolic violence, practice, etc) and treats them as evidence of these theories. Symbolic Interactionism was used to interpret small-world lives of one-to-one interaction of individuals with individuals and artefacts and their roles. Narrative Analysis was applied to stories taken from two interviews. I investigated how young people from poor rural backgrounds progressed towards a better standard of living. The socio-economic position of my participants in the social structures of their native villages hindered or facilitated their progress towards their goals. By interacting with people and artefacts in their environment, my participants managed to improve their standing in wider society. By getting an education, they found a way to cope with their day-to-day problems. But they were hindered in these attempts by the restrictions inherent in the existing social structures. This study found that my participants had to overcome obstacles which were so great that many other people from the same background never succeeded in doing so. This study is an attempt to look at their lives and the world at large through their eyes.

We are motivated by the problem of computing multicast routing structures in wireless ad-hoc networks modelled by special classes of graphs including unit disk graphs, quasi-unit disk graphs and (λ + 1)-claw-free graphs. Multicast communication can be established by a tree known as Steiner tree. Wireless ad-hoc networks must operate using limited resources, therefore, the suitability of nodes for inclusion in a Steiner tree can vary widely between different nodes. We model this by assuming that each node of the network is assigned a weight that represents the cost of including it in the Steiner tree. Our goal is to compute a Steiner tree with minimum total node weight. However, in scenarios where nodes and links are not reliable, a tree has the drawback that it can be disconnected by the failure of even a single link or node in the network. Therefore, we also consider various fault-tolerant routing structures called 2-edge-connected Steiner subgraphs, k-edge-connected Steiner subgraphs, 2-vertex-connected Steiner subgraphs, and 2-edge-connected group Steiner subgraphs. The problems we consider are NP-hard, so we are interested in algorithms that compute provably good approximate solutions in polynomial time. We present a generalization of Steiner subgraph problems referred to as the node-weighted δ-Steiner subgraph problem, where δ represents connectivity requirements. We present an algorithm with approximation ratio 0.5dρ for the node-weighted δ-Steiner subgraph problem, where d is the bounded maximum degree of the solution subgraph, and ρ is the approximation ratio of the edge-weighted version of the δ-Steiner subgraph problem. We then shown how to construct solution subgraphs of bounded maximum degree d in several graph classes for our problem variants. As a result, we obtain algorithms for the problems we consider, on graph classes that admit subgraphs of small degree, whose approximation ratios are better than the best known ratios for the same problems on general graphs.

The dynamics of everyday activities such as catching or kicking a ball, lifting a cup, crossing a road, or driving a vehicle require the ability to perceive and adjust to circumstances and environments. For interception or object avoidance, effective perception action coupling emerges from one's ability to optimally interpret meaningful visual information relative to self constraints and abilities. With increasing age, there is clear improvement in timing of one's behaviour to coincide with the visual information one perceives (Bard, Fleury, Carriere & Bellec, 1981). It was unclear how adults and children couple perceived information to their own constraints to successfully intercept when faced with increasingly complex tasks (i.e. faster moving objects, and travelling smaller approach angles to the object)-. Recent research in adults depicted the bearing angle (BA) as a key optic variable that allows one to reach the right place at the right time when intercepting a moving object, by maintaining a constant bearing angle (CBA). The present thesis adapted the study of this strategy in order to evaluate its use in a manual interceptive task. It examined the influence of extrinsic factors on the adherence to this strategy in synchronised movement control patterns. In effect the present work aimed td-address the issue of how perception action coupling influences the strategy and movement control (posture and timing) of adults and typically developing children when intercepting a moving object. . The findings of this thesis suggest that on approach for interception the CBA strategy is largely adhered to in adults and older children and not in younger children. This strategy breaks down on reaching, and the wrist compensates for movement requirements relative to ball velocity and approach angle. Larger deviations occurred when the angle of approach was small and for faster balls. Younger children were unable to adhere to the CBA strategy on approach, requiring more information from slower balls and smaller angles of approach, failing to effectively couple walking velocity to ball velocity. However there were signs of a compensatory strategy emerging. Greater postural adjustments were made by all three participant groups when there was less deviation from the CBA strategy and when intercepting faster balls. Adults and older children showed proximodistal control, making greater adjustments in the trunk during reaching. Younger children tended to make less adjustment at the trunk and controlled their reaching behaviour by making more distal adjustments. All participants were able to compensate successfully in their adaptations of posture and use of the CBA strategy, according to their age, ability and experience, to achieve the desired goal of interception. Improvement with age suggests that compliance to theCBA strategy may be attributed to enhanced coincidence anticipation behaviour.

Over the last twenty years there has been growing evidence of a distinct Islamic identity emerging from within the Western world, an identity that has been portrayed as incompatible with Western ideals. This thesis is based on a small-scale qualitative study of the reality of this identity, as experienced by twenty-three South Asian Muslims living in the south of England, and the impact on notions of citizenship and the rights and obligations this infers. The thesis contrasts Western notions of citizenship with Islamic thinking. It recognises that although there are points of convergence between the two, a fundamental difference remains. It is argued, where Western notions of citizenship give priority to individual sovereignty, Islamic notions place sovereignty in God and as such define citizenship as the relationship of the individual not to the state, but to God via the state. The thesis explores how this Islamic ideal is made relevant by South Asian Muslims living in Britain. Theoretically the thesis explores the way in which Muslim identity is universal, group centred and individual. It is argued that, despite differences, as humans we do share some universally shared values that give us a 'cornman human identity'. However these shared values are culturally embedded and experienced through distinct (albeit complex) 'cultural communities'. It is argued that just because people have, in certain circumstances, a group identity, it should not necessarily lead to the conclusion that everyone in that group will experience that identity in the same way. As such identity is simultaneously individual. Results of the research suggest that for South Asian Muslims of Britain assimilation is impossible and largely undesirable. However, they suggest that this does not mean that most Muslims do not want to be an 'integrated' aspect of British life. However integration does not mean 'being the same as'. There is a strong recognition that Muslims are different and there is to a large extent a desire for this difference to be maintained. Final analysis, of the data generated, indicates that there are four ideal typical strategies employed by British Muslims in making sense of their faith in the British context. These are identified as: That of 'Lapsed'/ambivalent Muslims where Islam is deemed important in that is provides a 'moral code' by which to live life but is, in the main, relegated to the private sphere. That of Selective Muslims where being a Muslim is of importance but for whom Islam does not impact on their lives in any substantive way. That of 'Traditional' Muslims where being a Muslim is very important but of equal importance is the ethno-cultural similarities they have with other Muslims. That of Engaged Muslims where there is an active engagement with Islam and a conscientious effort to implement Islam in all aspects of life Three levels of engagement with British society are also identified (although it must be recognised engagement with Islam does not necessarily lead to (dis)engagement with citizenship/the public sphere): engagement, partial engagement and disengagement. The thesis recognises that a multiculturalist paradigm has encouraged difference to be seen as static and unchanging, rather then fluid and dynamic as it is in reality. In this context Muslims' desire to keep to their faith (even if it is variously expressed), and retain (certain) social differences can be misunderstood as an unwillingness to 'integrate'. An ethnic notion of citizenship has made it hard for Muslims to be equal citizens contributing to their sense of being an 'outsider'. This thesis argues for a more inclusive definition of citizenship that understands that citizens will have multiple loyalties and responsibilities. Essentialist notions of Islam have perpetuated the misconception of Muslims as different with no commonalties with majority society. This is at the expense of historically rooted social and economic deprivation, and continuing (albeit not as obvious) prejudice and discrimination that many Muslim communities experience.

Introduction: The microbiota of apical periodontitis (AP) is extremely diverse. During root canal treatment, the gloves worn by dentists were found to be heavily contaminated with nosocomial pathogens transferred from the patients' saliva or skin, affecting the clinical outcome. Furthermore, it has been found that bacteraemia occurs following root canal treatment. Therefore, root canal infection and its treatment can be an enfolded primary infective focus for the dissemination of microbes via periapical vasculature, and their subsequent seeding in another organ. Apart from driving transient bacteraemia, oral-systemic interactions and their consequent outcomes could also be due to chronic systemic inflammation because of circulating active inflammatory markers. Studies have suggested a relationship between chronic AP and the risk of developing cardiovascular diseases (CVDs). Therefore, the challenge is to find that confirmatory link between contaminated gloves, nosocomial endodontic infections, and adverse systemic conditions. Aims: The aims of this longitudinal study are to: • Assess the effect of apical periodontitis on serum and salivary levels of inflammatory markers. • Assess the effect of root canal retreatment and periapical surgery on the levels of inflammatory markers at 3-, 6-, and 12-months post-treatment. • Correlate the levels of inflammatory markers with the pre-operative size of the radiolucency, treatment outcome, and levels of metabolic syndrome factors. • Characterise salivary, gloves, endodontic microbiota, and bacteraemia profile and investigate any association between nosocomial endodontic infections and bacteraemia. Materials and methods: 115 participants were recruited (65 with AP, 50 controls). Saliva, gloves, blood, and intracanal samples were collected from recruited patients while blood and saliva samples were collected from healthy controls. Patients were reviewed after 3-, 6-, and 12-months following treatment. Serum and saliva samples were analysed using Multiplex microbead immunoassay and ELISA for identifying the levels of interleukin (IL) - 1b, IL-6, IL-8, tumor necrosis factor (TNF) -a, matrix metalloprotease (MMP) -2, MMP-8, MMP-9, high sensitive C-reactive protein (hs-CRP), fibroblast growth factor (FGF)-23, vascular cell adhesion molecule (VCAM)-1, intercellular adhesion molecule (ICAM)-1, E-selectin, pentraxin 3, asymmetric dimethylarginine (ADMA), and complement (C3) and comparing these levels with those of healthy controls. Markers were further analysed at review appointments and correlated with metabolic syndrome factors, as well as with the size of radiolucencies and treatment outcome. Bacterial DNA extraction was undertaken from collected samples, and highthroughput sequencing of the 16S rRNA gene (V1-V2 hypervariable region) was performed using the Illumina MiSeq 300 platform according to manufacturers' protocol. Results: The presence of AP was seen to have caused an increase in the serum levels of IL-1b, hs-CRP, FGF-23, and ADMA and salivary hs-CRP at baseline. However, the successful treatment of AP resulted in reduction on the levels of FGF-23, pentraxin 3, TNF-a, ADMA, and VCAM-1, hence reducing the systemic burden of AP. Furthermore, the most abundant ASV from intracanal samples including Prevotella, Streptococcus, Staphylococcus and Actinomyces were also recovered from pre-operative blood samples, indicating bacteraemia associated with root canal infections. Finally, the nosocomial endodontic pathogens, Staphylococcus and Cutibacterium, were abundant in gloves, intracanal and blood samples. Conclusion: 1. AP increased the levels of inflammatory markers before the treatment. 2. Successful root canal treatment helps in reducing the levels of inflammatory markers. 3. The microbiome of saliva, blood, gloves, and intracanal are diverse, however, common microbial taxa were identified between these different sources. 4. Nosocomial pathogens were identified from gloves and inside the canal before obturation and in post-operative blood samples, suggesting bacteraemia. 5. AP and root canal treatment can cause bacteraemia.