Physiological and molecular responses to water-stress in local Saudi wheat cultivars

PhD ThesisThe kingdom of Saudi Arabia (KSA) is among the top countries in terms of agriculture in desert areas, the country uses highly developed agricultural technologies to grow different crops under challenging environmental conditions. The global climate change and the consequent increase in temperature and drought especially in the arid and semi-arid regions made the situation even more challenging. This work aimed at determining the physiological and molecular mechanisms underpinning drought-tolerance in wheat using six local Saudi wheat cultivars. Understanding the phycological responses and gene regulations under water stress could contribute to improving wheat cultivation in Saudi Arabia. My thesis was divided into four main experimental chapters, each chapter describes one experiment. The first experiment was to assess drought tolerance in a collection of six known wheat Cultivar grown in different regions of the KSA by comparing their growth and yield under well-watered conditions and water-stress conditions. Shoot weight and length, Root weight and length, Root: shoot ratio, RWC, proline content, soluble sugar content and protein content in addition to yield were used as selection criteria for drought resistance. The results allowed to group the studied wheats into two groups, drought resistant (193 Najran (Cv2) and 357 Sama (Cv3) ) and drought sensitive (181 Jizan (Cv1), 377 Rafha (Cv4), 562 Ma’ayah (Cv5) and 981 Najd (Cv6)). In the second experiment, RNA sequencing was performed in leaf samples harvested from water control and PEG-treated plants of one drought resistant 193 Najran (Cv2) and one drought sensitive cultivar (377 Rafha (Cv4)) at the vegetative, flowering and grain filling stage. Transcriptomic analysis aimed at finding differentially expressed genes and associated metabolic pathways in the two Saudi wheat cultivars under water stress at the three growth stages. This yielded 24.2 GB of sequence data. At least 40 million reads of 85 bp each were obtained per sample, Although genes from different pathways changed expression under water-stress, the increase in expression of genes associated with Photosynthesis, Amino acid metabolism and Secondary metabolism such as phenylpropanoid biosynthesis seemed to be the most important. The third experiment investigated the drought induced changes in the proteome in drought resistant 193 Najran (Cv2) and drought sensitive cultivar (377 Rafha (Cv4)) at the vegetative, flowering and grain filling stage, Proteomics analysis showed tangible changes in protein levels indicated a general regulation trend of plant defence under water stress, such as Stress/defence/detoxification proteins, Photosynthesis proteins, Carbohydrate metabolism proteins and Amino acid metabolism proteins. In a fourth experiment, based on the results of the transcriptomics and proteomics results together with the literature, the expression of four drought related genes The four genes included Dehydrin gene (DHn3), Bidirectional sugar transporter (Sweet), Phenylalanine ammonia-lyase (Pal5) and Serine hydroxy methyl transferase (Shmt) found to be various regulation in the six wheat cultivars based on their response to water stress. using qRT-PCR. The qRT-PCR analysis confirmed increased expression levels of these genes known to be up-regulated under water stress. From this work, I could conclude the following: 1. There is a big difference in the speed of response to water-stress between wheat Cultivars, this difference is associated with variation in transcript and protein expression levels at three growth stages. 2. The vulnerability of wheat plants to water stress is higher at the flowering stage compared to the vegetative and grain filling stages. Attempts to improve drought tolerance in wheat should be targeted to this growth stage. 3. The phenylpropanoid metabolic pathway plays a key role in resistance to water-stress in wheat and might be a target for improving drought resistance in this crop

Exploring persistent throat symptoms

M.D. ThesisBackground Patients commonly present with a range of persistent throat symptoms. There is still much research to be done to understand how the individual symptoms relate to each other. An improved understanding of any symptom relationships could aid in identifying groups of patients for particular treatments. An opportunity to explore throat symptoms in detail was provided by a clinical trial to assess the effectiveness of stomach acid lowering medication on patients’ throat and voice complaints. The aim was to identify a clinically meaningful classification of patients’ symptoms. Methods Baseline data for all patients entering the Trial of Proton Pump Inhibitors in Throat Symptoms (TOPPITS) was provided by the Newcastle University Clinical Trials Unit. Data included: demographics, three separate symptom questionnaires and a scoring assessment of throat appearances. The relationships between patient demographics, symptom scores and throat appearances were explored with scatter plots and pairwise correlation. Exploratory factor analysis (EFA) of the combined symptom questionnaires was conducted. Cluster analysis of patients using the factors generated by the EFA was then performed. Results Data for 344 patients analysed. The distributions of the questionnaire scores were comparable with published literature. The total scores from the three questionnaires were positively related with each other. No relationship was observed between the throat appearances and any of the three symptom questionnaires in this population. The EFA led to a seven factor model comprising factors of: voice, cough, gastrointestinal symptoms, airway symptoms and dysphagia, throat clearing, life events, and lump in the throat sensation. Cluster analysis failed to identify clinically meaningful groups of patients. Conclusions The TOPPITS baseline data confirmed that patients recruited to the trial reflect the wider population of patients presenting with persistent throat symptoms. No evidence of an association between throat appearances and patient reported symptoms was found in this study. Dimension reduction offered a simplified classification of symptoms, but clusters of patients based on this classification could not be identified. These results imply that individual throat symptoms cannot be used to define patient groups and that the term “persistent throat symptoms” to encompass all symptoms is appropriate to use in clinical practice

Sharing Economy Platforms: A study of Social Exchange, Reciprocity and Commitment

PhD ThesisA sharing economy is a socio-economic ecosystem enabling collaborative use of resources through online platforms. It is different from other economic forms of relations in that the exchange of resource may be free or for any other form of compensation. Growing transactions through sharing economy platforms reflects a change in individuals’ values and preferences in the consumption of resources. The use of platforms has implications in terms of redefining the behaviour of people and their interactions with each other. Also, it brings a social impact through providing people with access to resources that otherwise would not be affordable and redistributing underused ones. Given the assumed importance of the sharing economy in contributing to collective benefits, it is imperative to examine the drivers motivating the use of sharing economy platforms, the perceived outcomes of use behaviour and users’ commitment to platforms. This will make it possible to understand how to fuel the interest of users and will contribute to the development of the crowd-based economy. The literature on the sharing economy provides a limited view of the drivers which make people participate in sharing economy transactions. It lacks an overarching approach in examining the psychological and social factors that may facilitate or inhibit social exchange through platforms. When it comes to the impacts of the sharing economy on individuals, the literature has a speculative nature, lacking empirical evidence about the users' perspective on the outcomes of relations in terms of their social benefits and wellbeing. In addition, reciprocity in relations between the members of platforms has remained untouched by empirical scrutiny. While the literature has debated the importance of reciprocity norms in sharing economy relations, the determinants and outcomes of perceived reciprocity in the sharing economy have been left unexplored. Given the above, this thesis used a Social Exchange Theory framework for examining the drivers of participation in the sharing economy by exploring the effects of social capital factors and social values. Also, the research aimed to examine the contribution of the sharing economy to the perceived wellbeing of and social inclusion by users. To shed light on the determinants of perceived reciprocity, the thesis adopted the Equity Theory perceptive. That enabled us to examine the effect of social factors (social identity and social comparison), justice perception and individual personality traits on the formation of reciprocity perception. As far as the outcomes of perceived reciprocity are concerned, the research hypothesised the effect of perceived reciprocity on relationship commitment and coping mechanisms that people employ after comparing the outcomes against the contributions that they have made to exchange relations. To enrich the understanding of the potential variance in the relationships between the determinants of perceived reciprocity, perceived reciprocity and behavioural outcomes, the thesis aimed to test the moderating role of situational and personal factors (i.e. the value of exchange, social influence, response efficacy and self-efficacy). The research adopted a cross-sectional research design to collect data. To examine the proposed relationships, two surveys were conducted. The data were collected from the users of sharing economy platforms in the United States, who had access to the surveys through a URL. The questionnaires were designed in such a way as to provide detailed guidelines on completing the survey. It collected the demographic profile of the respondents and measured the constructs of the proposed research model, by preserving the anonymity of respondents. As a result of the first survey, 487 responses were collected. The final sample for the second survey consisted of 398 responses. A structural equation modelling approach was used to test the research model. The findings indicated that the use of the sharing economy was conditioned by the positive effect of egoistic belief, reciprocity norm, social value, and the negative effect of identification. The results made it possible to conclude that participation in the sharing economy is motivated by the need to create an image that would help people perform particular roles in the community. It was important for users that the exchange would be reciprocated either immediately or in future transactions and that the exchange satisfied personal selfish needs. The strong relationships between use behaviour, social inclusion and wellbeing, moderated by age, use frequency and use intensity, were confirmed. The analysis of the effects of the determinants on perceived reciprocity confirmed the importance of social identity, ingroup comparison, procedural justice and predisposition towards outcome maximisation. The effect of perceived reciprocity on relationship commitment and coping mechanisms (i.e. emotion-focused and problem-focused) moderated by individual and situational factors (the value of exchange, social influence, response efficacy and self-efficacy) was also supported. The results of the research contribute to the literature on the sharing economy. This research broadens the understanding of the social and psychological underpinnings of sharing economy practices. The results provide evidence about the role of community-oriented motives, which have long been debated in the literature. The adoption of the overarching social capital framework provided new insight into the nature of collaborative relations, which goes against the common and established representation of the sharing economy. In addition, the thesis provides empirical evidence about the effect of the sharing economy on social inclusion and subjective well-being, which had been speculated about before. The results contribute to the literature by explaining the determinants of perceived reciprocity in the sharing economy context, which have been under-researched previously. The examination of social factors and justice perception reconciles social and rational perspectives, while the effect of reciprocity on relationship commitment through coping behaviour sheds new light on the application of equity theory. From a practice perspective, the results provide insight into the psychological patterns of the sharing economy users, which might help regulate relations and increase collaborations. The strong relationship between use behaviour, social inclusion and subjective well-being equip policy-makers with evidence that can be set against the discussions on potential socio-economic disruptions incurred by the sharing economy. The thesis also offers implications for practice by informing practitioners about ways to ensure the loyalty of the users of sharing economy platforms

Fluorescent Nanomaterials from Biomass: Synthesis and Applications

Ph. D. Thesis.Energy crisis, environmental deterioration and dwindling fossil resources are the rising global concerns. As a result, utilising biomass waste as a green and renewable resource into valueadded materials is highly appealing for the sustainable world. Among various materials explored, carbon and its derivatives attract much more attention due to their intriguing properties and broad range of applications. This work focused on the conversion of biomass into activated carbon (AC) and its further development into fluorescent carbon nanomaterials for the energy and sensing applications. ‘Spent tea’ was selected as a food waste feedstock. A systematic study was carried out to produce char by pyrolysis and activate it using chemical activation. Consequently, a series of ACs with varying levels of porosity and surface areas (10 to >2000 m2 g -1 ) were produced. These ACs were employed as an alternate electrode material to study the effect of porosity on the charge transfer in vanadium redox flow battery. A thorough investigation on the further transformation of char into fluorescent nanomaterials lead to the production of graphene quantum dots (GQDs). An upgraded approach was adopted for the purification of these GQDs. The results showed that GQDs possessed 3-5 layered graphene structure with a size range of 2-20 nm and band gap varying from 2.67 to 2.95 eV. Under the premise of acquiring high yield, the activation and synthesis steps were combined into a single-step microwave treatment and GQDs were synthesised with a high yield of ~84%. Finally, the intensified and green synthesis of GQDs was accomplished under the direct hydrothermal carbonisation of biomass waste. The as-prepared GQDs were applied to design a selective and sensitive sensor for Fe3+ ions with a detection limit of as low as 2.5 x 10–6 M. The present work highlights the significance of preparing high-value nanomaterials from little value biomass waste.EPSR

Innovative techniques for deployment of microservices in cloud-edge environment

PhD ThesisThe evolution of microservice architecture allows complex applications to be structured into independent modular components (microservices) making them easier to develop and manage. Complemented with containers, microservices can be deployed across any cloud and edge environment. Although containerized microservices are getting popular in industry, less research is available specially in the area of performance characterization and optimized deployment of microservices. Depending on the application type (e.g. web, streaming) and the provided functionalities (e.g. ltering, encryption/decryption, storage), microservices are heterogeneous with speci c functional and Quality of Service (QoS) requirements. Further, cloud and edge environments are also complex with a huge number of cloud providers and edge devices along with their host con gurations. Due to these complexities, nding a suitable deployment solution for microservices becomes challenging. To handle the deployment of microservices in cloud and edge environments, this thesis presents multilateral research towards microservice performance characterization, run-time evaluation and system orchestration. Considering a variety of applications, numerous algorithms and policies have been proposed, implemented and prototyped. The main contributions of this thesis are given below: Characterizes the performance of containerized microservices considering various types of interference in the cloud environment. Proposes and models an orchestrator, SDBO for benchmarking simple webapplication microservices in a multi-cloud environment. SDBO is validated using an e-commerce test web-application. Proposes and models an advanced orchestrator, GeoBench for the deployment of complex web-application microservices in a multi-cloud environment. GeoBench is validated using a geo-distributed test web-application. - i - Proposes and models a run-time deployment framework for distributed streaming application microservices in a hybrid cloud-edge environment. The model is validated using a real-world healthcare analytics use case for human activity recognition.

Chitosan-Bioglass and chitosan-apatite-wollastonite composites for bone tissue engineering

PhD ThesisSynthetic inorganic-organic composites are of interest for bone tissue engineering as an alternative to natural grafts since they resemble the structure of the natural bone and degrade over time, enabling the new bone to grow. In this study, two types of composite materials- chitosan hydrogels with Bioglass 45S5 (BG) particles, and BG and apatite-wollastonite (AW) scaffolds coated with the chitosan hydrogel- have been investigated. Ceramics have been used for high mechanical strength, while chitosan was added to increase flexibility of the composites. Genipin was used as a low toxicity cross-linker, in order to improve stability of the chitosan hydrogels. The aim of this PhD research was to assess the properties of the chitosan- BG and AW composites and aid their advancement to in vitro and in vivo studies. The composites were analysed using scanning electron microscopy (SEM), FTIR spectroscopy, fluorescence intensity (FI) measurement and compression test. The BG-hydrogels and the hydrogel coated BG and AW scaffolds were immersed in the simulated body fluid (SBF) for up to 2 weeks and their structure and mechanical properties were examined. Results showed that BG addition to the chitosan hydrogels improved the mechanical properties both before and after immersion in SBF, but affected the FI measurement. Before coating both BG and AW scaffolds had a porous structure (pores 100-300 μm), while the treatment before SEM imaging affected the porosity of the coated scaffolds. Some apatite deposition was observed on the uncoated BG scaffolds after immersion in SBF for 2 weeks. AW scaffolds were mechanically stronger than BG scaffolds, independent of the coating or testing conditions (before or after SBF), with compressive stress up to 5.68 MPa for AW scaffolds compared to 1.20 MPa for BG scaffolds, reaching the lower limit of the cancellous bone. However, the coating did not improve the mechanical properties of the scaffolds. Nevertheless, after immersion in SBF (for up to 2 weeks), hydrogel coated BG scaffolds had higher compressive stress (~ 0.95 MPa) than uncoated BG scaffolds (~ 0.65 MPa).NUORS and CEA

Branding Central America for an International market : practitioner networks in the region’s film production

PhD ThesisThis dissertation studies Central American Cinema’s (CAC) role in the creation of meaning and belonging in the 24 winners – fiction, documentary, long- and shortformat productions – in the category ‘Best Central American Film’ at the Ícaro Film Festival between 2009 and 2014. This is the first festival to use Central America as its organising logic for validating and distributing films, which in fact bear varying degrees of affiliation to the region. This deployment of CAC is closer to a marketing strategy for targeting global audiences than a useful taxonomy for understanding the region's filmmaking. My methodology uses Actor-Network Theory to track those instances where ‘Central America’ participates in the interactions and translations involved in a movie’s end-toend production process. The resulting map presents each film as a heterogeneous network of affects, hardly bound to notions of the isthmus's territoriality or its cultural imaginaries. Instead, these exchanges perform a field – in the sense that Bourdieu gives this term. Cinema’s production, reproduction and validation within this field rely on cultural and economic capitals of a global and deterritorialized character. In this relational perspective, cinema is thought of as existing on a symbol-commodity continuum since, within this field, films interconnect local, non-territorial, for-profit and non-commercial possibilities. I argue that these motion pictures perform the extraction of value through exoticization, matching Beller’s notion of the cinematic mode of production and its promotion of capitalism. Such actions coexist with sincere intentions of self-representation or militancy with regards to subaltern concerns. However, CAC is a label that obscures the diversity of these films' interactions by imposing the historical, economic and symbolic preconceptions of the isthmus upon them. Such strategy depends on, and nurtures, a revived colonial perspective, reproducing structural/societal inequalities and asymmetries. The main beneficiaries are individuals with easy access to worldwide exchanges and transnational mobility.Universidad Estatal a Distancia, Costa Ric

A Monte Carlo simulation study of the factors influencing the performance of flood early warning systems

PhD ThesisIn recent decades, flood early warning systems (FEWSs) have been widely used as complementary non-structural mitigation measures in order to improve the population resilience to floods. FEWS research focusses mainly on flood forecasting techniques or social aspects of warning response, and end-to-end modelling frameworks that represent the entire FEWS forecast-decisionresponse/impact chain are rarely developed. A generic Monte Carlo simulation framework has been developed that represents an end-to-end FEWS in a versatile way, allowing factors influencing FEWS performance to be explored which cannot be analysed easily based on limited realworld data. The framework has been applied to a simulated generic fluvial case, where factors influencing FEWS performance in terms of reliability and economic effectiveness are explored. A new reliability performance measure based on inundation maps has been proposed. The framework has also been used to explore factors controlling the performance of a simulated FEWS representing an urban polder in Nanjing, China, with performance metrics based on waterlogging and pumping costs. For the generic fluvial case, the main results show that: i) the correlation between forecasts and observed values controls reliability; ii) probabilistic forecasts based on optimising a probabilistic threshold are robust to forecast biases in the mean and variance, iii) a FEWS based on uncertain forecasts is characterised by an optimal lead time that represents a balance between an adequate time to act in response and a reasonably good forecast; iv) the performance of the proactive action is the most important factor influencing the economic effectiveness of a FEWS. For the simulated flood-prone polder system case study, the results show that probabilistic forecasts of storm rainfall and runoff volume can considerably enhance the waterlogging and pumping metrics. The results of this research can be used to improve the performance of fluvial FEWSs, and to design FEWSs for polder systems.Ph.D. scholarship from the Secretary for Higher Education, Science, Technology and Innovation (SENESCYT) of the Government of Ecuador

Integrating life cycle assessment with genetic selection to reduce the environmental impacts of pig production

PhD ThesisSusPig project, funded through the Horizon 2020 ERA-NET scheme and through DEFR

Influences on foundation programme doctor’s choice of career specialty. Paediatrics as an exemplar case.

M. D. Thesis.No AbstractNewcastle upon Tyne Hospitals NHS Foundation Trus