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Navigating uncertainty: a phenomenological exploration of the lived experiences of internally displaced women and older adults in Nigeria
Full text linkIn the latest assessment conducted during Round 43 of the Displacement Tracking Matrix (DTM) by the International Organization for Migration (IOM), it was determined that Nigeria has approximately 2,375,661 IDPs. Among them, 24% are women, 19% are men, 31% are girls, and 26% are boys. The assessment further reveals that over 960,000 IDPs are residing in camp-like settings, while more than 1.4 million are living in host communities (DTM of IOM, 2023).
This research employs a phenomenological approach situated within the interpretivist paradigm to explore the lived experiences of women displaced by conflict and natural disasters. Through semi-structured in-depth interviews (n=32) and focus group discussions (n=4) involving 61 internally displaced women and older adults in four host communities in Abuja, Northcentral Nigeria, the study aims to unravel the complex layers of how displaced individuals cope, survive, and aspire for a better future. The investigation delves into their community roles, identities, and the psychosocial support they receive.
Utilising a thematic analysis enriched by theoretical frameworks encompassing concepts of structural violence, intersectionality, urban and feminist geographies, social determinants of health, and basic needs approaches, the study interprets the collected data. It examines human agency and coping mechanisms in informal settlements, discussing durable solutions to enhance the quality of life for displaced individuals. The findings portray a distressing scenario of living in precarious conditions, marked by gender-based violence against women and their families, intensified by insecurity, suffering, and the relentless struggle for survival. Despite mirroring the experiences of internally displaced women globally, the weakened socio-political system in Nigeria and inadequate governmental support compounds their plight.
However, the research refrains from portraying these internally displaced women and older adults as helpless victims, emphasising their strength and agency as architects of their new lives. The study highlights their commitment and determined efforts to ensure the survival of their families and communities, shedding light on their negotiation processes with both human and supernatural forces. Their cultural, religious, and spiritual knowledge emerges as a powerful tool for coping, providing a framework for interpreting and overcoming everyday challenges.
Effective solutions, however, demand renewed political will to address widespread poverty, social inequities, and gender inequality. This necessitates creating an enabling environment with proper infrastructure for economic growth, equal educational and economic opportunities for both genders, and a cultural shift towards recognising and appreciating the contributions of men and women in family, community, and nation-building
Fibroblast subsets dictate the stromal set-point in the synovium to influence the outcome of joint inflammation
No full textFibroblast subsets cause inflammation and damage. While their diversity and pathogenicity in arthritis are understood, little is known about how this fibroblast landscape is remodelled during the course of arthritis. This thesis explored the role of fibroblast population in joint inflammation.
I performed a temporal analysis of fibroblasts at the single cell resolution in spontaneously resolving models of inflammatory arthritis. During inflammatory phases, I identified an enrichment in Wnt signalling in synovial fibroblasts. In particular, WNT5A was associated with disease chronicity. Local administration of rWnt5a protein in mice undergoing inflammatory arthritis, lead to worsened disease severity through recruitment of pro-inflammatory macrophages and dendritic cells. In contrast, inhibition of Wnt signalling in mice with inflammation arthritis lead to
reduced joint swelling and leukocyte infiltration.
I also analysed fibroblasts during the resolving phase of arthritis, and identified a distinct subset of fibroblasts that exhibit a myofibroblast-like phenotype with a gene expression program linked to tissue repair. These fibroblasts express DKK3 (a member of the Dickkopf WNT Signalling Pathway Inhibitors with indeterminate biological function) and LRRC15 (a collagen binding protein), and show cross-talk with regulatory macrophages mediated by the TGF-β signalling pathway. In mice we observed that only these specific regulatory fibroblasts enhanced chromatin
accessibility, gene expression, and protein expression of DKK3 during resolution. Direct administration of rDKK3 reduced joint swelling and inflammation in mice, potentially by mediating polarisation of regulatory T Cells.
Together, the findings implicate Wnt signalling as a major driver of fibroblast-mediated inflammation and suggest that targeting the Wnt pathway could be a therapeutically relevant approach to rheumatoid arthritis, particularly in patients who do not respond to conventional treatments. We discovered regulatory fibroblasts that suppress inflammation and promote tissue repair by activating DKK3 signalling. These fibroblasts are activated during the resolution phase of inflammatory arthritis through cross-talk with MerTK+ macrophages. DKK3 secretion by these fibroblasts transforms the stromal landscape towards pro-repair phenotypes that control inflammation
The role of Neutrophils in oral Biofilm formation
No full textBiofilms are complex multicellular communities embedded in an extracellular polymeric substance (EPS). EPS contains extracellular DNA (eDNA), which contributes to its stability and complexity. There are many types of in vivo biofilms; the periodontal biofilm is one example. Bacterial biofilms are a leading cause of periodontitis, but host inflammatory responses against these are essential factors contributing to periodontal disease occurrence and severity. The primary protective leukocyte type against oral pathogens is neutrophil. This innate immune cell constantly surveils the periodontal tissues and migrates into the gingival crevice. Neutrophils express a variety of antimicrobial mechanisms in response to proinflammatory signals, including degranulation, phagocytosis, and the production of weblike extracellular DNA referred to as neutrophil extracellular traps (NETs). NET production is closely related to reactive oxygen species (ROS) production. An imbalance in neutrophil antimicrobial responses in the oral cavity is thought to contribute to periodontitis. This thesis describes the interactions of neutrophils with representative bacteria of early colonisers of periodontal biofilms, namely the streptococci S. oralis, S. mitis, and S. intermedius in single and mixed species scenarios. It also assesses several in vitro models for biofilm formation and evaluates neutrophil retention in these. Furthermore, the dynamics of neutrophils and the periodontal pathogenic strain A. actinomycetemcomitans were analysed and compared to the streptococcal species. The evaluated biofilm growing methods included two dynamic models (flow cell and flow chamber) and one static model (multiwell plate) for biofilm development..
Optimization of the matched irrigation to obturation with hydraulic cement sealers strategy
No full textTricalcium silicate sealer materials are vastly used in root canal obturation, mainly due to the calcium hydroxide release which is responsible for their biological and antimicrobial activity. The current study discusses the importance of selecting appropriate irrigation protocols for dentine preparation during root canal treatment for the choice of sealer and improve the adhesion and sealing ability of sealers with dentine. The study investigated the effect of different irrigation techniques, including continuous chelation, on dentine microstructure and aimed to choose the best irrigation protocol for endodontic treatment using Hydraulic calcium silicate cement (HCSC) sealers for obturation. The research also explored changes in the antimicrobial properties of HCSC sealers on interaction with dentine after irrigation with different chemical solutions using a split tooth model. Sterilisation of sample materials were also checked during the project.
Irrigating solutions can cause structural and chemical alterations of root dentin, affecting the mechanical and chemical adhesion of sealers to dentin and the antimicrobial properties of both dentin and sealer. Sodium hypochlorite (NaOCl), most widely used irrigant, being antimicrobial, eliminates the microbial load but can cause detrimental effects on the collagen. The most employed calcium chelator, Ethylenediaminetetraacetic acid (EDTA) can dissolve the inorganic debris and clear the smear layer produced by instrumentation but reduces the root dentine microhardness due to demineralization of the hydroxyapatite components of dentin. Hydraulic calcium silicate sealers interact with dentin more chemically and do not benefit from the property of calcium chelation and smear layer removal. The study used BioRoot RCS, TotalFill BC, and AH Plus jet as the test materials, and NaOCl, EDTA & Hydroxy ethylidene Di phosphonic Acid (HEDP) as the irrigation solutions. The results showed that in comparison to EDTA, irrigation with
HEDP resulted in a larger mineral concentration zone at the interface for hydraulic cements with less erosion of dentine. Furthermore, continuous chelation with HEDP improved the antimicrobial properties of the HCSC sealers without erosion of dentine making it the best irrigation protocol for endodontic treatment using tricalcium silicate sealers for obturation. Another finding of this project highlighted that hydraulic cement sealers are impacted by sterilization processes used prior to biological testing.
Regarding the method for studying the dentine sealer interface this study also concluded that when employing hydraulic cements, scanning electron microscopy and confocal laser scanning microscopy are not acceptable methods for studying the interface, Fourier-transform infrared spectroscopy can be used instead
Racialised geographies, white saviours and urban frontiers: examining the growth and establishment of English "no excuses" schools with critical race theory.
No full text“No excuses” schooling is a recent US policy import that has become established in England. Promoted by policymakers for its promise of greater academic achievement and closing racial achievement gaps, “no excuses” is characterised by conspicuously high academic standards and strict behaviour codes. However, critics challenge “no excuses”’ for its narrow view of educational purpose and harmful outcomes such as its association with disproportionate racial discipline and exclusion rates.
This study uses Critical Race Theory (CRT) to explore the growth and establishment of “no excuses” in England and its relationship to race. It adopts a mixed-methods design that deploys the complementary tools of QuantCrit, Critical Discourse Analysis (CDA) and Critical Policy Analysis (CPA). First, I examine school census data for 74 eligible sample “no excuses” schools using QuantCrit principles. Then, with CDA and CPA, I analyse qualitative texts from the DfE’s website that reference “no excuses”.
After comparing the 74 sample “no excuses” schools with their Local Authority and regional counterparts, I find a geographically racialised pattern reinforced through the DfE’s frequent references to ‘urban’ discourses in their website texts. Using Critical Policy Analysis principles, I argue that the DfE’s ostensibly colour-evasive ‘urban’ and ‘poverty’ discourses rhetoric might function as dog whistles to the White hegemonic alliance identified by Allen, and that this is reinforced by the DfE’s rendering of “no excuses” policymakers and policy actors as tough but benevolent White saviours.
Finally, using an interdisciplinary geographical lens, I argue that “no excuses” functions as part of a racial imagining of the urban as a missionary frontier; “no excuses”’ strong geographical orientation serves Whiteness by spatially constituting a racialised policy problem for its crusading, quasi-religious “no excuses” solution
Investigating the electrochemistry of critical metals on carbon black by Nano-impact techniques
No full textOur transition towards net zero emissions has necessitated the increased demand for critical metals such as manganese, nickel and ruthenium for use in batteries and other renewable technologies. The finite nature of these metals, coupled with the negative environmental and social impact of primary extraction methods, has led to the growing need for sustainable recovery techniques from secondary sources. Inefficiencies in primary extraction and metal recovery from secondary sources leads to the generation low-concentration metal waste streams. However, current recovery methods such as chemical precipitation, absorption and ion exchange are not suited to such low concentrations, often requiring costly pre-concentration steps. On the other hand, electrochemical methods, appear more well-suited due to their higher selectivity and energy efficiency. In particular, nano-impact electrochemistry has recently emerged as a promising recovery method for low-concentration solutions with the added advantage of higher rate of mass transport to the nanoparticles. This thesis explores the use of nano-impact electrochemistry as a potential method for recovering manganese, ruthenium and nickel from low-concentration solutions (0.5 – 1 mM) using inexpensive carbon black nanoparticle cores. Firstly, the electroreduction and electrooxidation of Mn(II) from 0.5 mM manganese sulfate and 20 mM potassium sulfate was investigated. Reductive impacts were observed in the presence of 5 pM carbon black and the deposition product was confirmed to be Mn(0) via scanning electron microscopy/ energy dispersive x-ray spectroscopy (SEM/EDX). Oxidative impacts were also observed in the presence in 5 pM carbon black and the deposition product was confirmed to be MnO2 and various other intermediate products via SEM/EDX and X-ray photoelectron spectroscopy (XPS).
Next, the electroreduction and electrooxidation of ruthenium from 1 mM ruthenium(III) chloride and 10 mM hydrochloric acid and 10 mM potassium chloride was studied. Impact electrochemistry was conducted and in the presence of 25 pM carbon black, reductive and oxidative impacts were recorded for the two respective processes. A long-term upscaled impact experiment for the reductive process yielded Ru-modified carbon black which were characterised via SEM/EDX, XPS and thermogravimetric analysis (TGA). Under partially-optimised conditions, >90% of ruthenium was recovered in ca. 8 hours. Finally, the electroreduction of nickel was studied from two electrolytes: 0.5 mM nickel(II) sulfate or nickel(II) chloride with the corresponding ammonium electrolyte. Reductive impacts were observed in the presence of 20 pM carbon black for both electrolytes. Upscaled long-term impact experiments were conducted and low-level nickel deposits were confirmed via SEM/EDX and inductively coupled plasmon/ mass spectrometry (ICP-MS)
Investigating the influence of substrate stiffness and cardiovascular ageing: structural, functional and metabolic responses using induced Pluripotent stem cell-derived Cardiomyocytes
No full textBackground
Cardiovascular ageing is characterised by fibrosis and increased stiffening of the extracellular matrix (ECM) due to excessive deposition of ECM proteins. The structural remodelling of the ECM can largely impact cardiomyocyte (CMs) behaviour and function. Induced pluripotent stem cell derived cardiomyocytes (iPSC-CMs) have been widely used in cardiac research to model cardiovascular diseases. Current experiments utilise tissue culture plastics, which are far stiffer than the natural environment of CMs, thus are not representative of physiological conditions.
Modelling cardiac ageing by recapitulating the stiffness of the healthy and fi- brotic myocardium using biomaterials can provide insight into mechanisms and pathways altered by ageing, ultimately contributing to the development of novel therapeutic strategies. Furthermore, cardiac diseases that display accelerated ageing phenotypes, such as Alström Syndrome (AS), can also be studied to enhance our understanding of cardiac ageing disease mechanisms and pathways.
Aims: This work attempts to develop a representative model of the healthy and ageing myocardium, by mimicking stiffnesses using biomaterial hydrogels (Chapter 3). Characterise the effect of ECM stiffnesses on the structure of iPSC- CMs (Chapter 4). Characterise the effect of ECM stiffnesses on iPSC-CM metabolic function (Chapter 5). Assess whether AS is a model of accelerated ageing using Phenoage(Chapter 6). Investigate the cardiac role of ALMS1 in AS using ALMS1 knockout (KO) iPSC-CMs to assess changes in structure, senescence, metabolism and calcium (Ca2+) handling dynamics (Chapter 7).
Methods: Polydimethylsiloxane (PDMS) hydrogels of 20kPa (healthy) and 130kPa (fibrotic) stiffnesses were developed. Ventricular iPSC-CMs were differentiated and plated onto PDMS hydrogels of stiffnesses and plastic/glass. Transcriptional, structural and functional profiles of iPSC-CMs on stiffnesses were investigated using methods such as Quantitative polymerase chain reaction (qPCR), Western blotting and Ca2+ optical mapping. Metabolic function of iPSC-CMs wasassessed using several techniques, including isotope labelled mass spectrometry.
Phenoage, a measure of biological ageing, was compared to chronological age for a cohort of patients with AS. Retrospective analysis of cardiovascular changes over time in AS patients using echocardiography were also assessed. ALMS1 KO iPSC-CMs were assessed for molecular, functional and metabolic changes compared to wildtype iPSC-CMs.
Results: iPSC-CMs cultured on 20kPa PDMS mimicking the healthy myocardium exhibit greater structural alignment, expression of cardiac markers and altered Ca2+ handling dynamics, indicative of CM maturity. iPSC-CMs cultured on plastic substrates exhibit a preference to glycolytic metabolism, increased lactic acid production and signs of a disease profile compared to iPSC-CMs cultured on softer PDMS substrates.
Patients with AS displayed a higher Phenoage compared to their chronolog- ical age, indicating AS serves as a model of accelerated ageing. Furthermore, ALMS1 KO iPSC-CMs displayed altered Ca2+ handling dynamics, changes in cellular bioenergetics and increased senescence, providing insight into the molecular changes occurring in AS.
Conclusions: The work supports the idea that ageing and stiffness of the ECM affects structure, function and metabolism of iPSC-CMs. The pathological metabolic phenotype of iPSC-CMs cultured on traditional cell culture plastics indicates that plastic may not serve as an effective control condition for experiments. iPSC-CM culture on softer substrates provides data of greater physiological relevance and is representative of a healthy myocardium, thus highlighting the importance of substrate stiffness and the impact the environment can have on iPSC-CM behaviour. This research demonstrates softer physiological substrates serve as an effective model for healthier and mature iPSC-CM cultures and should be used in research involving iPSC-CMs to accurately reflect cardiac environments. Novel findings also display AS as a disease model of accelerated ageing. The research further highlights the benefits of physiological model development and the use of iPSC-CMs to model cardiovascular diseases, allowing investigation into molecular mechanisms of diseases
The impact of two language learning methodologies: technology enhanced language learning and paper-based learning: an individual differences approach to effective learning and teaching
Full text linkAbstract
The present study has two areas of interest: Technology Enhanced Language Learning (TELL) and Individual Differences (IDs). Research on TELL has reported the positive impact of technology on L2 learning (e.g., Bester & Brand, 2013; Qiao & Zhao, 2023). Most studies targeted adult L2 learners, leaving the effects of TELL at younger ages understudied (e.g., only a fifth of studies has been conducted at secondary educational levels, cf., Chang & Hung, 2019). The present study aimed to examine this under-researched population and determine whether technology is conducive to young teenagers’ L2 learning. A variety of language structures (e.g., vocabulary, tenses, and word order in English), language skills (e.g., listening and speaking skills), and factors integral to learning (e.g., in-class attention and motivation in the lesson) were considered. Research on IDs has made contradictory claims about the impact of IDs on language learning. While many studies corroborated their relationship (e.g., Chrysochoou et
al., 2013; Schmidt, 2012), many others disputed the importance of such an effect (e.g., Felser & Roberts, 2007). To address this longstanding controversy, the relationship between IDs and language learning was explored, specifically with respect to the teaching methodology. Due to
the intricate relationship of IDs with various SLA factors, such attempts are scarce in the literature (Chen et al., 2021; Dewaele, 2012).
A 6-month classroom intervention study was conducted at a Lower Secondary School in Greece with L1 speakers of Greek aged 11-13 who were learning English as a Foreign Language (EFL). A control group (30 students) was taught in the traditional way using textbooks and paper-based materials, and an intervention group (35 students) was taught with digital resources (e.g., online games and videos, websites, Virtual and Augmented Reality, mobile phones) and paper-based teaching materials. Tests assessing the participants’ L2 knowledge were conducted before and after the intervention to assess any difference in linguistic improvement between the two groups. Tests measuring their individual differences
were also administered. Questionnaires on their motivation and attention in class were completed at the end of the intervention and in each lesson, respectively.
The results showed that technology improves learners’ vocabulary and speaking skills and contributes to their in-class attention and motivation. The other language learning dimensions – tenses, word order, and listening – equally improve in both teaching methodologies. Furthermore, the teaching methodology was found to modulate the relationship of IDs with language learning. The findings revealed that attentional capacities hinder word order acquisition in traditional paper-based classes and impede vocabulary acquisition in TELL classes. Conscientiousness contributed to L2 learners' in-class attention regardless of the teaching methodology. However, the results showed that L2 learners need to be academically
motivated to stay attentive in a traditional lesson. Additionally, they need to show conscientiousness traits to stay motivated in a traditionally taught class.
These findings suggest that a) although recent research highlights the effectiveness of TELL, an engaging technology-free L2 environment is still effective, and b) the teaching methodology, language learning, and learners’ IDs are intertwined and influence each other. This study contributes to the limited number of TELL studies on younger ages and establishes a framework for exploring the modulating role of the teaching methodology on the IDs-language relationship. Teaching recommendations based on the findings are provided to highlight the research impact of the study
Novel Aspects of 3D N= 2 Chern–Simons–Matter theories
Full text linkIn this thesis, we explore new results we recently obtained about the infrared physics of 3d N= 2 SQCD with a unitary gauge group, in particular in the presence of a non-zero Fayet–Iliopoulos (FI) parameter and with generic values of the Chern–Simons levels. We study the 3d gauged linear sigma model (GLSM) (also known as 3d A-model) approach to the computation of the 3d N = 2 twisted chiral ring of half-BPS lines. We analyse the moduli space of supersymmetric vacua in the theory, and we study its dependence on the Chern–Simons levels and the sign of the FI parameter. For particular values of the Chern–Simons levels, the twisted chiral ring has a neat interpretation in terms of the quantum K-theory (QK) of the complex Grassmannian variety. We propose a new set of linedefectsofthe3dgaugetheory,dubbedGrothendiecklines,whichrepresentequivariant Schubert classes in the QK ring. In particular, we show that the double Grothendieck polynomials, which represent the equivariant Chern characters of the Schubert classes, arise physically as Witten indices of certain quiver supersymmetric quantum mechanics. We also explain two distinct ways to compute K-theoretic enumerative invariants using the 3d GLSM approach. Moreover, we study infrared dualities associated with these 3d SQCDs. We use our techniques and analysis to test these dualities and, for some cases, we give a geometric interpretation for these dualities
Modelling thermodynamic and kinetic reactions between ceramic oxides and ti-alloy melt
Full text linkCasting titanium alloys presents significant challenges due to the high reactivity of
titanium in its molten state. This reactivity renders ceramic mould oxides highly
susceptible to chemical reactions, leading to premature mould failure and contamination
of the liquid metal by ceramic inclusions. Developing robust oxide systems
is therefore crucial to mitigating mould degradation and ensuring the homogeneity,
precision and geometric accuracy of the final cast. While numerous experimental
studies have examined the behaviour of oxides in contact with liquid titanium alloys,
there is limited understanding of how to select and design new oxide systems. Furthermore,
modelling efforts in this field remain scarce, often constrained by the lack
of reliable thermodynamic data, insufficient insight into metal-mould interactions
and an over reliance on simplified binary system models. This study introduces a
combined thermodynamic and kinetic framework to analyse metal-mould reactions.
CALPHAD-based thermodynamic data was used to evaluate the interactions between
titanium and mould oxides, providing inputs for a kinetic model based on
the Frozen Gradient Approximation (FGA). The FGA was extended to incorporate
multi-component and multi-phase interactions, enabling a more comprehensive analysis
of oxide behaviour. The results demonstrate that all mould oxides dissolve to
some extent and none studied remain completely stable in contact with the TiAl alloy.
However, several strategies were identified to minimize reaction rates and
improve oxide stability. Among these, multi-phase oxide systems, such as Al2O3-
Mullite and YAG-YAP demonstrated enhanced stability when combined, compared
to their performance as individual oxides. This is attributed to the potential of multiphase
oxides with shared ions to serve as more durable mould materials. Notably,
Al2O3-Mullite proved effective in suppressing alpha-case formation, further enhancing
oxide stability in titanium casting applications. In existing literature, Y2O3 is
widely regarded as the most stable oxide for titanium casting, with CaO typically
ranked as the second most stable. However, the sequential oxide selection method
employed in this study reveals additional oxides and oxide combinations with stability
levels that fall between those of yttria and calcia. These include, systems
such as YAM, CaYAlO4 and YAM-YAP. These demonstrate significant potential as
alternative mould materials, offering intermediate stability
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