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Working alone, working together: exploring craft learning in open access community making spaces
This research uses ethnographic methods to examine the experience of learning craft skills in artist-led and community-led craft spaces, with the home setting used as a counterpoint. I spent six months engaging in informal craft learning alongside others in a ceramics workshop and a printmaking workshop, and embroidering at home, in order to understand embodied and situated aspects of learning craft skills in shared spaces as an inexperienced maker. I find that the processes of making, and learning making, are iterative and messy, with the research process reflecting this messiness. The analogue making space can be conceptualised as a ‘permission space’ that extends the notion of Oldenburg’s (1999) third place through drawing attention to aspects of potential and constraint for the amateur maker. In relation to this I draw out the temporary, liminal nature of such spaces, through focus on commodified aspects of the experience, and in finding that this is a space in which to be otherwise (Woodyer, 2012). I show how improvisation is a key aspect of developing both skills and creative voice, and that the journey towards enskilment is not linear, or even necessary, in such spaces.
The application of theories of play to the journey towards enskilment extends the work of Brown, Greig, and Ferraro (2017) and Patchett & Mann (2017). Through its focus on autotelic aspects of informal creative activity, this research offers a counterpoint to the current significant cultural and societal emphasis placed on the value of instrumental aspects of everyday creativity; this research also offers potential for future investigation into the relationship between autotelic creative practice and strategic learning in informal craft learning contexts
Natural polyhydroxyalkanoates-based composite materials for bone tissue engineering applications
Bone tumour removal and traumas with large defects are the main catastrophic events impeding complete bone healing. Autologous and allogenic bone grafting, and biologically inert metallic devices have limitations such as non-availability of autogenous bone, risk of infectious disease transmission, surgical removal, and bacterial infections. In the last decades, bone tissue engineering (BTE) emerged as a promising field to overcome those limitations by using a variety of biomaterials such as natural and synthetic polymers, ceramic, metals, carbon-based materials, and composite materials, to develop artificial implants with suitable biocompatibility, mechanical properties, and bioactivity to act as a support structure and enhance bone regeneration. However, further improvements are needed in order to provide physicians with implants displaying higher levels of biocompatibility, mechanical properties closer to the bone tissue’s ones, and suitable rate of biodegradation in vivo allowing enough time for tissue regeneration to occur before losing mechanical stability due to degradation. In this study, the development of innovative composite materials for BTE applications has been explored, using a natural polymer from the family of polyhydroxyalkanoates (PHAs), called poly(3-hydroxybutyrate) [P(3HB)], and a set of different organic and inorganic fillers as reinforcing and bioactive agents. PHAs are a family of natural and sustainable polymers produced through a bacteria-driven fermentation process using renewable carbon sources. They have been widely proved to be highly biocompatible and able to biodegrade in vivo without any toxic by-products. Among them, P(3HB) has been selected as suitable candidate for bone tissue engineering due to its stiffness. However, PHAs do not possess the required osteoinduction and
osteconduction capacity to enhance bone formation. Therefore, a borosilicate-based bioactive glasses doped with zinc oxide (BS-Zn) and a set of carbon-based materials have been selected as fillers to provide bioactivity to the composite materials. Firstly, a large-scale production of P(3HB) has been optimised and performed, and the polymer extensively characterised to confirm its suitability for the study. Subsequently, solvent casting technique was exploited to develop P(3HB)/BS-Zn scaffolds with different high concentrations
(% v/v) of filler, resulting in improved mechanical properties, high level of biocompatibility, and enhanced mineralisation and osteogenic activity of human primary osteoblast cells compared to the neat polymer and positive control. Moreover, the antibacterial efficacy due to the presence of ZnO in the bioglass network has been demonstrated against E. coli and S. aureus pathogen bacteria strains, revealing the potential of the composites to prevent bacterial infections post-implantation of the scaffolds. The same processing approach was used to create P(3HB)/carbon-based material (CBMs) composite scaffolds, and their mechanical and thermal properties as well as the interaction and distribution of fillers and polymeric matrix was evaluated. Starbon, Activated Carbon, and
Inkjet were selected as innovative carbon materials obtained from different natural and synthetic sources. The study proved the enhanced osteoconductive capacity of the composite materials in vitro. In particular, P(3HB)/Inkjet and P(3HB)/Starbon demonstrated the highest level of biocompatibility and mineralisation as well as the most homogeneous distribution of the filler within the polymer network. Therefore, the two composites were selected to proceed with further evaluation of their potential by developing 3D constructs exploiting a melt extrusion-based 3D printing process. After a preliminary investigation, P(3HB)/Inkjet showed the best performances in terms of interconnected porosity and filler dispersion in the 3D structure. Therefore, the bone regeneration capacity of the composite was evaluated using human primary osteoblast cells, resulting in improved cell adhesion and proliferation, as well as osteogenic activity and calcium deposit as sign of mineralisation compared to neat P(3HB) and positive control. In conclusion, this study achieved the successful development of innovative promising composite scaffolds suitable to act as bone substitutes and strengthen the potential of BTE to help bone healing in the clinic
Non-linear Cross-lingual Mappings for Low-resource Speech Recognition
Multilingual speech recognition systems usually benefit low-resource languages but suffer degradation in the performance of several languages compared with their monolingual counterparts. With an objective to improve speech recognition performance for a target language, closer languages are chosen to build a multilingual system. The number of shared phonemes among them is usually taken into account to estimate the languages' closeness. However, various close languages such as English, German, Dutch and many others with significant phonemes overlap yield higher error rates from multilingual speech recognition systems when compared with their monolingual speech recognition systems. Limited attention has been paid towards investigating the performance trends of multilingual speech recognition systems and their relation with acoustic-phonetic similarities across the languages.
The objective of this research is to estimate cross-lingual acoustic-phonetic similarities and their impact on multilingual speech recognition systems. To that end, a novel data-driven approach is proposed to analyse the output from several monolingual acoustic models given a target language speech signal. This technique measures the similarities between posterior distributions from various monolingual acoustic models given a target language speech signal. Neural networks-based `mapping models' are trained that transform the distributions from hybrid DNN-HMM acoustic models of different languages into a directly comparable form. The analysis shows that the `closeness' among the languages can not be truly estimated by the size of the shared phonemes set. Entropy analysis of the proposed mapping models exhibits that a language with lesser overlap can be more amenable to cross-lingual transfer, and hence more beneficial in the multilingual setup.
The proposed mapping models are then exploited to improve low-resource speech recognition. A novel approach of hybrid DNN-HMM acoustic model fusion is proposed in a multilingual setup. Posterior distributions from different monolingual acoustic models, given a target language speech signal, are fused. Mapping models are trained for source-target language pairs to transform posteriors
from a source acoustic model to the target language. These models require limited data as compared to the acoustic model training. Multilingual model fusion yields a relative average gain of 4.56% and 3.77% for selected languages from the Babel data set when compared with multilingual and monolingual baselines respectively. Cross-lingual model fusion shows that comparable results can be achieved without using posteriors from the language-dependent ASR system.
Substantial phonemes overlap across the languages and the relatively smaller size of the universal phoneme set is expected to make the mapping task less challenging compared with mapping models for end-to-end ASR systems where tokens are usually graphemes or sub-word units.
Furthermore, end-to-end speech recognition systems have been dominated over hybrid DNN-HMM models. So, the concept of learnable cross-lingual mappings is extended for end-to-end speech recognition to study if mappings could be learnt for end-to-end speech recognition systems. Mapping models are also employed to transliterate the source languages to the target language without using parallel data. Finally, the source audio and its transliteration are used for data augmentation to retrain the target language ASR system. The retrained speech recognition system with data augmentation results in a relative gain of up to 5% over the baseline monolingual speech recognition system for the selected languages from the Babel data set.
Student-teacher learning or knowledge distillation has been previously used to address data scarcity issues for the training of speech recognition systems. However, a limitation of knowledge distillation training is that the student model classes must be a proper or improper subset of the teacher model classes. It prevents distillation from even acoustically similar languages if the character sets are not the same. In this work, the aforementioned limitation is addressed by proposing a novel multilingual knowledge distillation approach that exploits the earlier proposed mapping models. A pre-trained mapping model is used to map posteriors from a teacher language ASR system to the student language ASR system. These mapped posteriors are used as soft labels for knowledge distillation. Various teacher ensemble schemes are experimented with to train an ASR system for low-resource languages. A model trained with MUST learning reduces relative character error rate up to 9.5% in comparison with a baseline monolingual ASR
Designing for Perspective Challenging Experiences in Games
Digital games are seen to be highly appropriate vehicles for supporting reflection. Researchers and game designers have concentrated on creating reflective games, in particular, games that facilitate transformative reflection. However, before a person’s perspective can be transformed, it must first be challenged. Research around how perspective challenges are experienced by players, and what explicitly prompts reflective breakdowns is scarce. Therefore, this thesis aims to understand: (1) how games challenge players’ perspectives, (2) what kinds of experiences that entails, and (3) how to support game developers to design perspective challenges.
The first study involved participants reporting perspective challenging moments within games (N = 101). The results indicate that players identified perspective challenging moments in a wide variety of games, found them be enjoyable, thought provoking, and left a lasting impression. The second investigation utilised micro phenomenological interviews and systematic self-observation diaries to capture players’ lived experience (N = 16). The resulting ’Model of Perspective Challenging Experiences’ captures two types of perspective challenges: (1) endo-game (within the game) and (2) exo-game (outside the game). The model was applied towards reducing mental health stigma in two resources: (1) the ’Designing Games to Challenge the Stigma Around Mental Health’ white paper, and (2) the ’Challenging Perspectives on Mental Health’ (CPMH) Toolkit. The final study evaluated acceptability of the CPMH toolkit by observing game developers
using it in practice (N = 20). A content analysis confirmed that the CPMH toolkit successfully facilitated conversations and game ideation about perspective challenging experiences, where participants attested to the toolkit’s acceptability.
The thesis has four main contributions: (1) a definition for what a perspective challenge is, (2) evidence that perspective challenging experiences has two kinds of triggers: endo-game and exogame, (3) a model of perspective challenging experiences, and (4) two translational resources to support designing perspective challenging experiences
Learning to Lead: Induction and professional development needs of novice school principals in Sri Lanka
If the school leaders and leadership are crucially important, it is a deep concern how they professionally develop to perform their roles (Crow et al, 2008) and what their professional development (PD) needs are. This emphasises the need for well-designed PD training for school leaders to develop the required PD skills and facilitate their PD needs. In line with this idea, this thesis examines the PD needs of novice principals with reference to the Sri Lankan context. This study analyses how the PD needs of novice principals were addressed through two training programmes offered by the Ministry of Education in collaboration with the National Institute of Education, Sri Lanka. Among the two trainings, induction training has been offered for more than 20 years without any policy-level initiatives at the initial leadership role of the novice principals. In contrast, the Basic Principals Programme (BPP), a continuing PD training programme for novice principals who are serving leaders, was introduced by the National Competency Framework for School Leadership and Management (NCFSLM) and is a new policy initiative with international support.
As the study focuses on understanding the lived experience of study participants, the study was conducted as a phenomenological study as it provides the opportunity to understand and describe the subjective experiences and perspectives of stakeholders on the PD needs and offered training programmes. Data collected through qualitative interviews were corroborated with documentary analysis, and the data were analysed and presented thematically, for better understanding of subjective information of the novice principals towards PD needs and received training.
The key finding of this study is that the PD needs of the novice principals were person-centred, to begin with, and focused on developing themselves as leaders and enhancing leadership skills to lead others. In contrast, as serving leaders, they identified the development of their leadership competencies as a requirement to lead others effectively. In other words, there was a shift from focusing on self-centred human capital to extending relationships as social capital. The novice principals’ PD needs were embedded within four underlying concepts: a) leader and leadership development; b) soft skills and hard skills, c) intrapersonal and interpersonal skills, and d) human capital and social capital, which are complex and interconnected.
The findings also illustrated that the induction training focused on developing the self of a novice as a leader with a range of soft skills rather than hard skills. The soft skill development included intra and inter-personal skills that helped them to effectively navigate various challenges in their initial leadership roles. In contrast, continuing PD training (BPP) aims to develop competencies in facilitating the PD needs of serving leaders. These are task-oriented and centred around specific skills. Thus, data does not support the idea that BPP facilitated serving leaders to meet their PD needs. The delays in offering the programmes due to the impact of COVID-19, influenced by administrative circumstances, were identified as reasons for the failure to address the PD needs of novice principals.
The thesis concludes by presenting a set of recommendations for national-level policymakers. These recommendations include conducting a needs survey before initiating training programmes, standardising the offered training according to the NCFSLM, and implementing measures to ensure quality and consistency. This involves ongoing training and updates for administrative offices and trainers
Modelling of Alternative Divertor Power Exhaust
Controlled nuclear fusion on Earth is one of the most powerful technological dreams devised by humanity. The prospect of an artificial star on our planet could offer reliable, clean, and widely accessible energy for all, using the most common element in the universe as fuel. Despite all its prospects, an economic fusion power plant has not yet been developed, due to the enormity and complexity of the challenges in the way of such a feat. In tokamaks, where a high temperature plasma is confined using strong magnetic fields, one of the most pressing issues is that of plasma exhaust. As these fusion devices become more powerful and better confined, the peak heat and particle loads on surrounding surfaces is enough to erode and damage even the strongest materials.
The focus of this thesis is the study of alternative divertors, one proposed solution to the tokamak exhaust challenge. By modelling edge plasmas under different shapes, conditions, and magnetic and physical geometries, this work furthers the understanding of how these different geometric features can influence divertor performance. The process of detachment, characterised by significant power and pressure loss in an edge plasma, is a key focal point for this modelling work.
By developing and extending reduced models, and comparing them to hundreds of 2D simulations of alternative divertors, good agreement is found in terms of the predicted impacts of divertor features on detachment. These models are also compared with experiment, where certain broad predictions and ideas from reduced modelling seem present in experimental data. The agreement is not perfect, and when it comes to the movement of so-called detachment fronts, the location of these fronts is much more stable in 2D simulations and experiment than the reduced modelling. Notwithstanding, this work provides first of a kind verification of a reduced physics framework to understand the control of divertor detachment
Improving inhibitor and glycerol tolerance of Cupriavidus necator H16 via adaptive laboratory evolution (ALE)
Applying bio-orthogonal chemistry and fluorescence microscopy to probe spatio-temporal dynamics in the bacterial outer membrane
Exploring the influence of resilience on midwives’ and student midwives' career-related decisions: A Constructivist Grounded Theory Study
A national shortage of midwives, coupled with the increasing complexity of maternal health issues
and the rising age of childbearing women, has resulted in the role of the midwife being an
increasingly challenging one. Many midwives experience emotional distress, low morale, and job
dissatisfaction and are making the decision to leave the profession as a result. Recruiting and
retaining resilient individuals who can survive and thrive in complex and demanding working
environments in the NHS has been widely suggested as a key strategy for improving retention in
the midwifery profession. However, limited evidence exists on the influence of resilience on
midwives’ career experiences, choices, and trajectories, particularly during the early phases of
stress and job dissatisfaction.
This thesis presents a Grounded theory (GT) study which explored the influence of resilience on
midwives’ and student midwives’ career-related decisions. Thirty-six participants from the North
of England took part in individual semi-structured interviews. Data were collected and analysed
following Charmaz’s (2014) Constructivist Grounded theory approach and constant comparative
methods.
The substantive Grounded theory (GT), ‘Time to change’ was developed comprising four core
concepts: ‘Fitting in’, ‘Being valued,’ ‘Feeling in control’ and ‘Getting the balance right’. Central to
the theory was the importance of confidence, experience, and perceived support on fluctuating
levels of resilience, and midwives’ subsequent ability to make career related decisions including
changes in role, work-life balance, and the decision to remain in the profession.
Findings from the study indicate that participants perceived resilience, alongside a number of
other influences, had a significant role to play in midwives’ and student midwives’ career related decisions.
The findings provide novel insight into the influence of resilience in midwifery
that has relevance for the profession and the potential to inform midwifery policy, practice, and education for the future
THE ORGANISATION OF CONFINED WATER IN SELF-ASSEMBLED LIPID NANOSTRUCTURES
Phospholipid-based liposomes are abundantly studied in biomembrane research and used in numerous medical and biotechnological applications. When dispersed in water, lipids hydrate to form a variety of complex nanostructures. Despite our knowledge of membrane nanostructure and its mechanical properties under various environmental conditions, there is still a lack of understanding on interfacial lipid-water interactions. In this work, we have investigated the nature of the confined water layer for variety of lipids, focusing on the phosphatidylcholine (PC) phosphatidylethanolamine (PE) species. The majority of the studies are conducted in the fluid lamellar phase of multilamellar vesicles with and without the inclusion of ions dissolved in the water phase. Additionally, a binary lipid mixture in the inverse hexagonal (HII) phase was also investigated. We are proposing a new model for describing three different water regions, which have been characterised, using a combination of Small Angle X-ray Scattering (SAXS) and volumetric data. The three regions concern (i) ‘the headgroup water’, (ii) ‘perturbed water’ near the membrane interface and (iii) a core layer of ‘free water’ (unperturbed water). The behaviour of all three layers is discussed as a function of temperature, influences of chain saturation, headgroup type and as a function of ion concentration, influenced by mono- and divalent ions. Under temperature, the overall water layer and perturbed water layer thickness increase, whilst the free water layer displays the opposite trend for PCs and, remarkably, in PEs the free water layer is completely absent. This behaviour in PEs is different when in the inverse hexagonal phase, where a free water region develops and remains relatively unchanged as the micelle packing frustration is alleviated. Most interestingly, the mechanical behaviour of the inverse hexagonal phase is different orientated towards the corners and flat sides of the Wigner Seitz cell. Understandably, the disorder is relatively enhanced within the hexagon’s corners (decompression zones), concurrently with the amount of perturbed waters in this region. The influence of ions onto the lamellar phase water layers is heavily dependent on ion valency and also on a specific ions kosmotropic or chaotropic potential. The trend of the cationic Hofmeister series is reflected in the perturbed water layer, increasing from Mg2+, Na+ to K+