3 resultados para IGBTs in parallel
em Glasgow Theses Service
Resumo:
Background: Community participation has become an integral part of many areas of public policy over the last two decades. For a variety of reasons, ranging from concerns about social cohesion and unrest to perceived failings in public services, governments in the UK and elsewhere have turned to communities as both a site of intervention and a potential solution. In contemporary policy, the shift to community is exemplified by the UK Government’s Big Society/Localism agenda and the Scottish Government’s emphasis on Community Empowerment. Through such policies, communities have been increasingly encouraged to help themselves in various ways, to work with public agencies in reshaping services, and to become more engaged in the democratic process. These developments have led some theorists to argue that responsibilities are being shifted from the state onto communities, representing a new form of 'government through community' (Rose, 1996; Imrie and Raco, 2003). Despite this policy development, there is surprisingly little evidence which demonstrates the outcomes of the different forms of community participation. This study attempts to address this gap in two ways. Firstly, it explores the ways in which community participation policy in Scotland and England are playing out in practice. And secondly, it assesses the outcomes of different forms of community participation taking place within these broad policy contexts. Methodology: The study employs an innovative combination of the two main theory-based evaluation methodologies, Theories of Change (ToC) and Realist Evaluation (RE), building on ideas generated by earlier applications of each approach (Blamey and Mackenzie, 2007). ToC methodology is used to analyse the national policy frameworks and the general approach of community organisations in six case studies, three in Scotland and three in England. The local evidence from the community organisations’ theories of change is then used to analyse and critique the assumptions which underlie the Localism and Community Empowerment policies. Alongside this, across the six case studies, a RE approach is utilised to examine the specific mechanisms which operate to deliver outcomes from community participation processes, and to explore the contextual factors which influence their operation. Given the innovative methodological approach, the study also engages in some focused reflection on the practicality and usefulness of combining ToC and RE approaches. Findings: The case studies provide significant evidence of the outcomes that community organisations can deliver through directly providing services or facilities, and through influencing public services. Important contextual factors in both countries include particular strengths within communities and positive relationships with at least part of the local state, although this often exists in parallel with elements of conflict. Notably this evidence suggests that the idea of responsibilisation needs to be examined in a more nuanced fashion, incorporating issues of risk and power, as well the active agency of communities and the local state. Thus communities may sometimes willingly take on responsibility in return for power, although this may also engender significant risk, with the balance between these three elements being significantly mediated by local government. The evidence also highlights the impacts of austerity on community participation, with cuts to local government budgets in particular increasing the degree of risk and responsibility for communities and reducing opportunities for power. Furthermore, the case studies demonstrate the importance of inequalities within and between communities, operating through a socio-economic gradient in community capacity. This has the potential to make community participation policy regressive as more affluent communities are more able to take advantage of additional powers and local authorities have less resource to support the capacity of more disadvantaged communities. For Localism in particular, the findings suggest that some of the ‘new community rights’ may provide opportunities for communities to gain power and generate positive social outcomes. However, the English case studies also highlight the substantial risks involved and the extent to which such opportunities are being undermined by austerity. The case studies suggest that cuts to local government budgets have the potential to undermine some aspects of Localism almost entirely, and that the very limited interest in inequalities means that Localism may be both ‘empowering the powerful’ (Hastings and Matthews, 2014) and further disempowering the powerless. For Community Empowerment, the study demonstrates the ways in which community organisations can gain power and deliver positive social outcomes within the broad policy framework. However, whilst Community Empowerment is ostensibly less regressive, there are still significant challenges to be addressed. In particular, the case studies highlight significant constraints on the notion that communities can ‘choose their own level of empowerment’, and the assumption of partnership working between communities and the local state needs to take into account the evidence of very mixed relationships in practice. Most importantly, whilst austerity has had more limited impacts on local government in Scotland so far, the projected cuts in this area may leave Community Empowerment vulnerable to the dangers of regressive impact highlighted for Localism. Methodologically, the study shows that ToC and RE can be practically applied together and that there may be significant benefits of the combination. ToC offers a productive framework for policy analysis and combining this with data derived from local ToCs provides a powerful lens through which to examine and critique the aims and assumptions of national policy. ToC models also provide a useful framework within which to identify specific causal mechanisms, using RE methodology and, again, the data from local ToC work can enable significant learning about ‘what works for whom in what circumstances’ (Pawson and Tilley, 1997).
Resumo:
Dengue fever is one of the most important mosquito-borne diseases worldwide and is caused by infection with dengue virus (DENV). The disease is endemic in tropical and sub-tropical regions and has increased remarkably in the last few decades. At present, there is no antiviral or approved vaccine against the virus. Treatment of dengue patients is usually supportive, through oral or intravenous rehydration, or by blood transfusion for more severe dengue cases. Infection of DENV in humans and mosquitoes involves a complex interplay between the virus and host factors. This results in regulation of numerous intracellular processes, such as signal transduction and gene transcription which leads to progression of disease. To understand the mechanisms underlying the disease, the study of virus and host factors is therefore essential and could lead to the identification of human proteins modulating an essential step in the virus life cycle. Knowledge of these human proteins could lead to the discovery of potential new drug targets and disease control strategies in the future. Recent advances of high throughput screening technologies have provided researchers with molecular tools to carry out investigations on a large scale. Several studies have focused on determination of the host factors during DENV infection in human and mosquito cells. For instance, a genome-wide RNA interference (RNAi) screen has identified host factors that potentially play an important role in both DENV and West Nile virus replication (Krishnan et al. 2008). In the present study, a high-throughput yeast two-hybrid screen has been utilised in order to identify human factors interacting with DENV non-structural proteins. From the screen, 94 potential human interactors were identified. These include proteins involved in immune signalling regulation, potassium voltage-gated channels, transcriptional regulators, protein transporters and endoplasmic reticulum-associated proteins. Validation of fifteen of these human interactions revealed twelve of them strongly interacted with DENV proteins. Two proteins of particular interest were selected for further investigations of functional biological systems at the molecular level. These proteins, including a nuclear-associated protein BANP and a voltage-gated potassium channel Kv1.3, both have been identified through interaction with the DENV NS2A. BANP is known to be involved in NF-kB immune signalling pathway, whereas, Kv1.3 is known to play an important role in regulating passive flow of potassium ions upon changes in the cell transmembrane potential. This study also initiated a construction of an Aedes aegypti cDNA library for use with DENV proteins in Y2H screen. However, several issues were encountered during the study which made the library unsuitable for protein interaction analysis. In parallel, innate immune signalling was also optimised for downstream analysis. Overall, the work presented in this thesis, in particular the Y2H screen provides a number of human factors potentially targeted by DENV during infection. Nonetheless, more work is required to be done in order to validate these proteins and determine their functional properties, as well as testing them with infectious DENV to establish a biological significance. In the long term, data from this study will be useful for investigating potential human factors for development of antiviral strategies against dengue.
Resumo:
Vertebrate genomes are organised into a variety of nuclear environments and chromatin states that have profound effects on the regulation of gene transcription. This variation presents a major challenge to the expression of transgenes for experimental research, genetic therapies and the production of biopharmaceuticals. The majority of transgenes succumb to transcriptional silencing by their chromosomal environment when they are randomly integrated into the genome, a phenomenon known as chromosomal position effect (CPE). It is not always feasible to target transgene integration to transcriptionally permissive “safe harbour” loci that favour transgene expression, so there remains an unmet need to identify gene regulatory elements that can be added to transgenes which protect them against CPE. Dominant regulatory elements (DREs) with chromatin barrier (or boundary) activity have been shown to protect transgenes from CPE. The HS4 element from the chicken beta-globin locus and the A2UCOE element from a human housekeeping gene locus have been shown to function as DRE barriers in a wide variety of cell types and species. Despite rapid advances in the profiling of transcription factor binding, chromatin states and chromosomal looping interactions, progress towards functionally validating the many candidate barrier elements in vertebrates has been very slow. This is largely due to the lack of a tractable and efficient assay for chromatin barrier activity. In this study, I have developed the RGBarrier assay system to test the chromatin barrier activity of candidate DREs at pre-defined isogenic loci in human cells. The RGBarrier assay consists in a Flp-based RMCE reaction for the integration of an expression construct, carrying candidate DREs, in a pre-characterised chromosomal location. The RGBarrier system involves the tracking of red, green and blue fluorescent proteins by flow cytometry to monitor on-target versus off-target integration and transgene expression. The analysis of the reporter (GFP) expression for several weeks gives a measure of the protective ability of each candidate elements from chromosomal silencing. This assay can be scaled up to test tens of new putative barrier elements in the same chromosomal context in parallel. The defined chromosomal contexts of the RGBarrier assays will allow for detailed mechanistic studies of chromosomal silencing and DRE barrier element action. Understanding these mechanisms will be of paramount importance for the design of specific solutions for overcoming chromosomal silencing in specific transgenic applications.