13506 research outputs found
Sort by
Art and Creativity for HIV/AIDS Awareness, Prevention, and Empowerment of Young People in Uganda
Get PDFArt, youth engagement and informality in the context of HIV prevention have been generally ignored by most researchers and stakeholders within the HIV programming and policy arenas, thus silencing the plight of urban youth infected with and affected by HIV/AIDS. In response, this thesis draws on the case of peri-urban settings of Kampala, Uganda to bring geographies of applied sculpture, HIV/AIDS prevention, and youth empowerment into dialogue, informed by the notions of art having the capacity to move beyond the spaces of galleries into an expanded field, and thus, beyond the visual and into the social spheres. In liaison with local NGOs (The Uganda AIDS Support Organisation - TASO, National Guidance and Empowerment Network for People Living with HIV/AIDS - NGEN+ and Lungujja Community based Health care Organisation – LUCOHECO, it adopts a mixed methodological approach, including applied art and participatory techniques - observation, video, storytelling, and interviews, to understand the lived experiences of young people (15-24 years) in marginalized spaces in Kampala. The thesis first examines the general context of using ethnography and applied social sculpture to explore every day experiences by facilitating the engagement of young people in open communication about the epidemic. This is intended to enable them to act in confronting stigma, taboos, and their precarious existence, while raising their awareness about HIV/AIDS. The thesis then explores the everyday precarious existence of young people in informal settings in Kampala. It proceeds to examine how workshops with these young people allowed collective engagement which, in turn, influenced the creation of artworks envisioned to act as communication tools for raising awareness of HIV/AIDS with the potential for livelihood benefits. Finally, the thesis examines young people’s active involvement in participatory workshops for HIV/AIDS prevention, providing ethnographic evidence regarding the artmaking process, the conversations that ensued as they worked, and the creation of applied objects/forms that enabled them to build their confidence to freely express about the precarities affecting their lives, countering taboos, and encouraging them to change their behaviours and practices while potentially acting as change agents in their own communities. It highlights the significance of stimulating open conversations about HIV/AIDS - as a starting point towards confronting stigma and other aspects of precarity, while advocating for the incorporation of the approach into practice by public health experts, policymakers, and development practitioners. The thesis shows the strengths of applied sculpture as an approach that has potential for making sense of ordinary everyday experiences, finding meaning and crafting clarity of young people’s lived experiences in the context of HIV/AIDS. It concludes that applied sculpture is potentially an important tool in tackling HIV/AIDS and its attendant problems by engendering and facilitating open conversations and social economic development through an engagement with the voices and agency of young people in Uganda and beyond
One-Loop Analytic Results for the Higgs Boson Plus Four Partons and Searches for Supersymmetry
Get PDFIn this thesis we present compact analytic expressions for the production of the Higgs boson plus two jets at one-loop mediated by both a scalar and a fermion. The results are derived using generalised unitarity methods and retain the full mass dependence of the mediating particle. We use the relationship between the fermion and scalar theories to simplify the algebra in the fermion theory; many of the required integral coefficients are identical and for those that differ, the difference is of a lower rank than the scalar result.
We use these calculations to study the production of the Higgs boson plus two jets in the Minimal Supersymmetric Standard Model, assuming stop squarks are the dominant mediator. This is a potential channel for an indirect search for stop squarks, in particular we focus on the region where the lightest stop squark mass is similar to that of the top quark. However, although the 1-jet process shows improved discrimination over the inclusive process, we find there is no benefit gained from the 2-jet process
The Relationship Between Self-complexity and Leadership Behaviors: A Dual Mediation Model
No full textThe importance of self-complexity on leadership has been discussed by several theoretical studies. The present research draws upon Linville’s (1985, 1987) social cognitive perspective of self-complexity, which is defined as a function of two things: the number of aspects that one uses to cognitively organize knowledge about the self, and the degree of relatedness of these aspects” (Linville, 1985, p. 97), to serve as one of the limited empirical studies that examine its associations with leadership behaviors. To assess self-complexity, I develop a measurement that focuses on capturing the structure of the self at the role level and adopt the pairwise comparison method to enrich our understanding of self-complexity. In addition, I also draw upon self-control and goal shielding theories to examine the psychological factors such as time and centrality in self-complexity.
Regarding leadership behaviors, I studied two often-seen leadership behaviors in the current research. For positive leadership behavior, I study servant leadership, which refers to “an (1) other-oriented approach to leadership (2) manifested through one-on-one prioritizing of follower individual needs and interests, (3) and outward reorienting of their concern for self towards concern for others within the organization and larger community” (Eva, Robin, Sendjaya, Van Dierendonck, & Liden, 2019, p.114). For the negative leadership behavior, I study abusive supervision, which is defined as “subordinates’ perceptions of the extent to which supervisors engage in the sustained display of hostile verbal and nonverbal behaviors, excluding physical contact” (Tepper, 2000, p.178).
To study the associations between self-complexity and leadership behaviors, I employ two different perspectives: Self-control and cognitive theories. From the self-control perspective, I adopt self-control and conservation of resource theories to examine the indirect associations between self-complexity and leadership behaviors via ego depletion, which is defined as “a state in which the self does not have all the resources it has normally” (Baumeister & Vohs, 2007, p.116). From the cognitive perspective, I employ cognitive theories to examine the indirect associations between self-complexity and leadership behaviors via cognitive flexibility, which is defined as “the ability of individuals to restructure knowledge in multiple different ways depending on changing situational demands” (Gino & Ariely, 2012, p.446).
Four studies were conducted in the current research. The results in Study 1 (U.K. sample, N = 179) showed that the number of self-aspects and the degree of overlap among self-aspects were negatively associated with ego depletion and were positively associated with cognitive flexibility. Moreover, ego-depleted leaders were found to be more likely to behave abusively toward their followers, whereas cognitively flexible leaders were found to be less likely to abuse their followers. Regarding the psychological factors, results in Study 1 showed that the relationship between the interaction of a high number of self-aspects and a high degree of overlap among self-aspects and ego depletion was weaker when the time was short rather than high. The results in Study 2 (Taiwan sample, N = 332) also showed that the degree of overlap among self-aspects was negatively associated with ego depletion and positively associated with cognitive flexibility. Nevertheless, the number of self-aspects was not found to be negatively associated with ego depletion nor positively associated with cognitive flexibility. Study 2 also showed similar findings regarding leadership behaviors; ego depletion was positively associated with abusive supervision, and cognitive flexibility was negatively associated with abusive supervision.
Study 3 specifically focused on testing the differences between the traditional pen and paper trait sorting task (N = 98) and the newly introduced method of measuring self-complexity (N = 110) and on examining the positive leadership behavior (i.e., servant leadership) in the current research model. The results in Study 3 showed that both methods had similar findings to Studies 1 and 2. However, the newly introduced method that measures the structure of the self at the role level seems to be a better approach than Linville’s free-response format in predicting ego depletion and cognitive flexibility. In addition, ego-depleted leaders were not found to be less likely to display servant leadership in the workplace, and cognitively flexible leaders were found to be more likely to display servant leadership behaviors in the workplace. The results in Study 4 (N = 144 leaders and N = 450 followers) showed that the number of self-aspects and the degree of overlap among self-aspects were negatively associated with ego depletion and were positively associated with cognitive flexibility. Moreover, ego-depleted leaders were more likely to be perceived as abusive supervisors, and cognitively flexible leaders were less likely to be perceived as abusive supervisors and more likely to be perceived as servant leadership by their followers
From Romance into Reality: Influences of Medieval Romance Literature on the Architecture and Design of Later Medieval English Castles and Elite Landscapes
Get PDFThis PhD provides an original reassessment of the extent to which medieval Romance literature influenced late medieval English castles, and their landscape, architecture, structuration and design. Drawing a perspective from buildings archaeology, this research brings together multiple avenues of research within medieval studies,
including medieval literature, chivalry, socio-political history and castle studies, in order to argue that Romance literature definitely did impact the medieval ´elite secular built environment, which, in previous studies, has remained mostly speculative or inconclusive. This Romantic influence is identified in broad, generalized architectural trends, as well as within unique features at individual sites. This research also addresses personal aspirations and self-associations underlying and motivating these Romantic influences within their socio-political and geographical contexts. The first four chapters of this thesis explore topical themes of castle studies, medieval Romance literature and contemporary chivalric values to provide necessary background information and highlight the interrelated nature of these disparate aspects of medieval culture. Building upon the information from these foundation
chapters, three case study chapters identify, assess and discuss specific examples of Romanticized medieval architecture that I have classified into three distinct subheadings: that within broad trends of Romanticized chivalric structuration, specific spaces and features in the surrounding castle landscape, and finally, through individualised instances with site-specific features. These case studies are followed by a discussion to contextualize and summarize the Romantic influences within medieval
´elite society and its built environment, as well as the lasting impacts of Romance and chivalry which have continued to shape English national identity
Malaria vector ecology and housing in The Gambia
Get PDFMalaria is a major health challenge in low- and middle-income countries in the Global South, especially in sub-Saharan Africa. In the last 50 years the combined distribution and appropriate use of insecticide-treated nets, insecticide residual spraying and mass drug administration campaigns dramatically reduced malaria cases globally. This reduction, however, has stopped and even reversed in some places. In the last decade, this concern has led to the exploration of innovative solutions for vector control and to the return of strategies like house modification, which were popular before the widespread use of insecticides that took place after World War 2.
In this thesis, I explored how several specific house-based modificacions can reduce mosquito house entry, and possibly malaria infection rates, through a series of experiments conducted in two rural villages in The Gambia. Experiments conducted in Wellingara assessed the effect on mosquito hut entry and indoor temperature of raising an experimental hut above the ground and the effect of closing the ground floor in an elevated hut using four experimental huts. Studies in Wali Kunda explored how indoor temperature was affected by different roof colours and the effect on mosquito house entry and indoor temperature of passive and active ventilation in two experimental houses. Finally, a qualitative study assessed the routines that took place in the domestic space and how it relates to risk of malaria infection and vector control programmes
Monitoring the UK’s terrestrial mammals using camera traps: from the field to the classroom
Get PDFAcross the world, biodiversity is being lost at an unprecedented rate, heavily driven by
anthropogenic activities. In order to understand ecosystem changes, and to conserve or
manage species effectively, ecological monitoring on large spatial and temporal scales is
needed. For some taxa, this is relatively straightforward. However, due to the nocturnal and
elusive nature of many species, monitoring of terrestrial mammals can be challenging. In this
thesis, I explore how camera traps and citizen science can be used to improve terrestrial
mammal monitoring efforts in the UK. Firstly, I use the camera trap distance sampling method
to calculate densities of a range of mammal species in North-East England, UK. The density
estimates produced were similar to previously published estimates, and estimates for some
species are amongst the most precise produced to date. Secondly, I evaluate spatial bias in
MammalWeb, a camera trap citizen science dataset, by comparing subsets of data from
MammalWeb to data from my systematic camera trapping survey. Habitat bias in the
MammalWeb dataset impacted the species captured and measures of occupancy and habitat
at a regional-level. I show that by sub-setting analysis to habitat level, the impact of spatial
bias can be reduced; however, expanding spatial coverage of the MammalWeb project would
be valuable in the future. In the second part of the thesis, I focus on a study engaging primary
schools in camera trapping to monitor wildlife in their school grounds. I show that school
pupils benefitted from participating in this project by gaining knowledge of UK mammal
species and increasing their connection to nature. Schools also contributed valuable data to
the MammalWeb project by uploading footage from a range of habitats, including some
currently under-represented in the MammalWeb database. Teachers were very positive
about the project, although some noted challenges to engaging long-term; there were also
differences in longevity of engagement, depending on whether schools took part in a pupil
workshop or teacher training. The findings presented throughout this thesis will help drive
forward how MammalWeb and other projects with similar objectives can use camera trapping
and citizen science approaches to maximise benefits in the areas of both ecological
monitoring and engagement. More generally, my results highlight the potential of citizen
science and camera trapping for improving large-scale mammal monitoring and ultimately,
for tackling the challenges we face in managing widespread biodiversity loss
Joint Design of Wireless Fronthaul and Access Links in Massive MIMO CRANs
Get PDFCloud radio access network (CRAN) has emerged as a promising mobile network architecture for the current 5th generation (5G) and beyond networks. This thesis focuses on novel architectures and optimization approaches for CRAN systems with massive multiple-input multiple-output (MIMO) enabled in the wireless fronthaul link. In particular, we propose a joint design of wireless fronthaul and access links for CRANs and aim to maximize the network spectral efficiency (SE) and energy efficiency (EE).
Regarding downlink transmission in massive MIMO CRANs, the precoding designs of the access link are optimized by accounting for both perfect instantaneous channel state information (CSI) and stochastic CSI of the access link separately. The system design adopts a decompress-and-forward (DCF) scheme at the remote radio heads (RRHs), with optimization of the multivariate compression covariance noise. Constrained by the maximum power budgets set for the central unit (CU) and RRHs, we aim to maximize the network sum-rate and minimize the total transmit power for all user equipments (UEs). Moreover, we present a separate optimization design and compare its performance, feasibility, and computational efficiency with the proposed joint design. Considering the uplink transmission, we utilize a compress-and-forward (CF) scheme at the RRHs. Assuming that perfect CSI is available at the CU, our objective is to optimize the precoding matrix of the access link while adopting conventional precoding methods for the fronthaul link. This thesis also proposes an unmanned aerial vehicle (UAV)-enabled CRAN architecture with a massive MIMO CU as a supplement system to the terrestrial communication networks. The locations of UAVs are optimized along with compression noise, precoding matrices, and transmit power. To tackle the non-convex optimization problems described above, we employ efficient iterative algorithms and conduct a thorough exploration of practical simulations, yielding promising results that outperform benchmark schemes.
In summary, this thesis explores future wireless CRAN architectures, leveraging promising technologies including massive MIMO and UAV-enabled communications. Furthermore, this work presents comprehensive optimization designs aimed at further enhancing the network efficiency
Investigating Pattern Triggered Immunity in Arabidopsis thaliana Upon Botrytis cinerea Infection and the Role of SUMOylation in This Signalling Pathway
Get PDFFungal disease in agriculture poses a significant risk to global food security. The development of crops that are resistant to fungal infection is central to addressing this challenge. Botrytis cinerea is a pathogenic fungus that causes grey mould disease in over 200 crop species, causing mass economic and agricultural losses. During B. cinerea infection in Arabidopsis thaliana, chitin from the fungal cell wall is sensed by a transmembrane protein called CERK1. CERK1 transduces a signal to the rest of the cell to initiate pattern triggered immunity (PTI) defences against the invading fungal pathogen. SUMOylation is a type of post-translational modification that is involved in many types of stress response and has been shown to also play a role in immunity during fungal infection. The goal of this research project was to gain a deeper understanding of plant PTI and to shed light on the potential role of SUMOylation in this signalling pathway during B. cinerea infection. After discovering that CERK1 constructs that were to be used in this project contained unintended mutations, CERK1 was re-cloned and SUMO-site mutations were re-inserted. Using the new CERK1 wild type (CERK1WT) and the CERK1 double SUMO-site mutant (CERK12KR) constructs in co-immunoprecipitation assays with SUMO1, it was determined that both CERK1WT and CERK12KR are SUMOylated upon chitin elicitation. Using fungal spore infection assays, it was confirmed that CERK1 is an essential protein for plant immunity upon B. cinerea infection due to greater lesion development in the CERK1 knockout transgenic line than in wild type plants. It remains unclear whether SUMOylation of CERK1 is essential for initiating an immune response to B. cinerea infection, and this is a recommended route for further investigation into this research
Try a little tenderness: Investigating the evolution of empathy through comparing consolation and reassurance in our closest relatives, bonobos (Pan paniscus) and chimpanzees (Pan troglodytes)
Get PDFEmpathy—the ability to share, understand, and respond to the emotions and states of others—is often considered a cornerstone of the human experience. As our closest living relatives, bonobos (Pan paniscus) and chimpanzees (Pan troglodytes) are often used as models for the evolution of human behaviour, and comparative research often seeks to identify interspecific variation. However, comparisons often consist of single groups of small captive populations, and recent investigations have indicated substantial within-species differences in bonobo and chimpanzee cognitive and emotional behaviour. In this thesis, to contribute to the investigation of empathy’s evolution, I provide the first comprehensive systematic comparison of sanctuary-living groups of bonobos and chimpanzees regarding their use of reassuring body contact during two periods of social tension: post-conflict consolation and pre-feeding affiliation. Using a combination of naturalistic observations and an experimental method, I show the Pan apes share similar tendencies to engage in consolation and pre-feeding reassurance, including the use of genital contacts during social tension. Instead, considerable variation lies at the individual, dyadic, and group levels. Two bonobo communities varied in consolatory tendencies, and whilst younger individuals offered consolation more than older individuals, young male chimpanzees consoled more than other chimpanzees. Results also indicate that contact affiliation around feeding is associated with reduced conflict and promotes an individual’s access to a competitive feeding zone. Furthermore, contact affiliation between socially central sex pairings in each species—bonobo females, and chimpanzee males—were associated with group-level social tolerance, indicating that reinforced affiliative bonds between dominant individuals in both species promotes more crowded, peaceful feeding. My findings support considering individual variation and multiple groups of diverse populations when making species-level comparisons in ethology. A bottom-up approach assessing species- and group-specific abilities could reveal the ancient ancestry of empathy, and what factors promote or inhibit its emergence
The impact of changing intestinal amino acid transporter expression and luminal nutrient content on healthy ageing
Get PDFThanks to improved sanitation and advances in healthcare, humans are living for longer than ever before, however, the number of years an individual remains healthy has not improved, putting a strain on health services. Improving the health of this elderly population is therefore of great importance.
Unintentional weight loss, along with metabolic and body-composition changes, are common characteristics of ageing and frailty, associated with significant adverse health outcomes, increased mortality and progressive disability. While these changes may be partially explained by dietary changes and the metabolic cost of immune activation and inflammation that occur with age, other factors must contribute.
The intestine has been shown to be a key organ in the progression of ageing, undergoing many changes which directly impact mortality and morbidity. Nutrient absorption is a key role of the intestine which has not been studied in the context of ageing. Given the age-related intestinal changes which may impact its function, from an increased bacterial load to dysplasia and loss of intestinal barrier integrity, it is likely that nutrient absorption is a contributing factor to this unintentional weight loss.
This thesis aims to uncover whether changes to intestinal nutrient dynamics impact ageing phenotypes, using Drosophila as a model. Here I developed an assay to understand changes in the intestinal nutrient profile with age, showing increased luminal/faecal concentrations of amino acids upon advancing age and microbial association. This assay has the potential to be more widely applied to answer other biological questions. My data also links changes in the expression of intestinal amino acid transporters to age-related decline, through interaction with several key age- related pathways. Knockdown of the cationic amino acid transporter Slimfast, which has been shown to act as a nutrient sensor through interaction with mTORC1, extended lifespan and was unexpectedly found to link the JNK and JAK-STAT pathways. Modulation of the glutamate transporter, Eaat1, was also shown to impact lifespan, and stem-cell expression of Eaat1 was found to be important for their division. This opens a new avenue for ageing research, to understand the biology of ageing, and gain a better understanding of how targeted dietary interventions may improve the outcomes of ageing
Data sources:
Access Repository Dashboard
Do you manage Open Research Online? Become a CORE Member to access insider analytics, issue reports and manage access to outputs from your repository in the CORE Repository Dashboard! 👇