• A macroeconometric model for Algeria. A medium term macroeconometric model for Algeria 1963-1984, a policy simulation approach to Algerian development problems.

      Wilson, P.R.D.; Bowers, D.; Laabas, Belkacem (University of BradfordDepartment of Social and Economic Studies, 2011-08-26)
      This thesis is concerned with the development and use of a macroeconometric model for the Algerian economy between 1963 and 1984. The model was built because of a systematic lack of applied econometric studies pertaining to Algeria at both the macroeconomic and microeconomic level. It is hoped that the model will fill a gap in this area and will contribute to the much neglected field of applied econometric research with regard to Algeria. This lack of applied econometric studies for Algeria meant that the modelling exercise described here has had to rely on an extensive specification search based on evidence relating to Algeria's economic structure and policy, economic theory, and the experience of Less Developed Countries in the area of macroeconomic model-building. The lack of data was a major constraint in this area and part of this study consisted of collecting and compiling a large database. After the country's independence in 1962, Algerian macroeconomic policy aimed to create a strong industrial system and to satisfy the population's basic needs. It relied on heavy industrialisation to modernise the economy, oil revenues to finance development, and central planning as the major tool of macroeconomic regulation. The accumulation rate was high and the growth record was generally good. However high unemployment and inflation, considerable disequilibrium, low productivity, a vulnerable balance of payments and unsustainable external debt are the major macroeconomic problems that policy-makers have had to face. The model's equations were first estimated using the OLS method and were subjected to stringent statistical tests. The degree of test significance and parameter correspondence to a priori views on the economy was good. when the model was constructed, it was estimated using a 2SLS principal component method. The OLD results were found to be reasonably feasible. The equations were collected into a system of 63 equations and solved using dynamic simulation technique. The model was solved successfully and its tracking of historical data was reasonably good. Further tests were carried out to study its dynamic features. Having constructed the model, it was then used extensively to perform simulation analysis. The experiments ranged from those concerning the goverment's current expenditure to its monetary policy. In all, nine simulation exercises were carried out. These were revealing on the workings of the Algerian economy. The model was further used in scenario analysis. First the model was used to develop an ex ante forecast employing a linear trend model for the exogenous variables. The forecast database was used to generate multipliers. The policy analysis was constructed to coincide with the implementation of the Second Five Year Plan (1985-1989). The feasibility of the plan was examined by varying the price of oil according to three hypotheses. The aim of this test was to develop a realistic framework for applied macroeconomic analysis.
    • Madness and narrative understanding: A comparison of two female firsthand narratives of madness in the pre and post enlightenment periods.

      Burkitt, Ian; Thomas, Phil; Torn, Alison (University of BradfordSchool of Health Studies, 2009-08-24)
      This study uses a narrative analytic approach to explore the similarities and differences between pre-Enlightenment and post-Enlightenment firsthand accounts of madness in order to answer the question; what is the relationship between madness, narrative, understanding, identity and recovery? Drawing on the work of Foucault, the research traces the historical and cultural development of conceptualisations of reason and unreason, the rise of psychiatry and the marginalisation of the voice of madness. I argue that this marginalisation is continued in narrative research where the focus is on the stories of the physically ill, rather than madness. The narrative method provides a means of giving space to these marginalised voices and it is Bakhtin¿s constructs of dialogicism, polyphony, unfinalizability and the chronotope that provide the tools for the narrative analysis of two female English writers; Margery Kempe and Mary Barnes. The analysis highlights three critical issues in relation to firsthand narratives of madness. First, the blurred boundaries between madness and mysticism and the role of metaphor in understanding distressing experiences. Second, the complex, multi-dimensional nature of subjective timespace that challenges the linear assumptions underlying both narrative and recovery, which, I argue, demands a radical reconceptualisation of both constructs. Third, the liminal social positioning within the analysed accounts is closely related to Bakhtin¿s notion of unfinalizability, a form of being that enables the search for meaning and the transformation of the self. Insights can be gained from this research that may place stories and understanding central in contemporary healthcare.
    • Making a Difference? European Union’s Response to Conflict and Mass Atrocities in the Democratic Republic of Congo (1994-2009)

      Pankhurst, Donna T.; Bizimana Kayinamura, Ladislas (University of BradfordDepartment of Peace Studies, 2013)
      This dissertation scrutinises two related claims that were particularly heightened in 2009 as the European Union (EU) was celebrating the first tenth anniversary of its European Security and Defence Policy (ESDP), the implementing arm of its Common Foreign and Security Policy (CFSP). First, the two policy frameworks allegedly embodied sufficient added value for bettering EU intervention for human protection purposes in third places. Second, the ESDP supposedly enabled the EU to make a difference in its response to two bloody wars that broke out in the Democratic Republic of Congo (DR Congo) successively in 1996 and 1998. This thesis argues that the alleged added value and difference have been overstated at best. While various studies have taken a similar position, they have important shortcomings for at least four reasons: lack of a comprehensive account of the CFSP motives, capacities, and response; exclusive focus on civil and military operations; focus on the post-Second Congo War period; and a lack of conceptual clarity regarding two key terms – ‘conflict resolution’ and ‘peacebuilding’. This thesis goes beyond generalisation and undertakes a forensic examination of the CFSP statements, decisions, and actions precisely through the lens of Conflict Resolution (CR): a specific subject area of study with its own normative, theoretical, and practical advantages and shortcomings; and with a more comprehensive and indeed seminal conceptualisation of peacebuilding. The outcome is a far more nuanced assessment of failure and success of the EU’s peace endeavours in this context than can be obtained through a broad-brush approach to analysis
    • Management capacity development to support business growth. A Grounded Theory Study in German SMEs

      Niemann, Eva; Harding, Nancy H.; Stiles, P.; Treutler, Alexandra (University of BradfordSchool of Management, 2014)
      Understanding how small and medium-sized enterprises (SMEs) support their growth strategies through the development of management capacity (MC) is of fundamental importance, particularly given the central role SMEs play in the economies of their respective countries, and the fact that there is a lack of research and useful theories in this specific field. The objective of this study is to develop a framework for MC development (MCD) in growth-oriented SMEs. This study builds on grounded theory by conducting 14 interviews with key informants: 12 founders/CEOs and 2 top managers of German SMEs (and former SMEs). Data analysis was performed by using the qualitative data analysis software ATLAS.ti. The major findings of the study are that, contrary to previous SME HR research, most companies in this study had formal processes for HR practices in place, and there was clear evidence of certain forms of strategic plans, the pursuit of strategic objectives and the taking of strategic decisions manifested itself. In addition, most participants considered their organisation to have an alignment between growth strategy and MCD strategy. However, implementing it into business practice was perceived as extremely challenging. This study thus contributes to the field of SHRM literature by showing how MC is instantiated in SMEs. Furthermore, there is, arguably, a valuable practical application of the research study as it provides growth-oriented SMEs with a clear and logical framework from which to develop MC pro-actively as a major facet of their growth strategy.
    • Managing Next Generation Networks (NGNs) based on the Service-Oriented Architechture (SOA). Design, Development and testing of a message-based Network Management platform for the integration of heterogeneous management systems.

      Hu, Yim Fun; Lei, Pouwan; Kotsopoulos, Konstantinos (University of BradfordSchool of Engineering Design and Technology, 2011-12-06)
      Next Generation Networks (NGNs) aim to provide a unified network infrastructure to offer multimedia data and telecommunication services through IP convergence. NGNs utilize multiple broadband, QoS-enabled transport technologies, creating a converged packet-switched network infrastructure, where service-related functions are separated from the transport functions. This requires significant changes in the way how networks are managed to handle the complexity and heterogeneity of NGNs. This thesis proposes a Service Oriented Architecture (SOA) based management framework that integrates heterogeneous management systems in a loose coupling manner. The key benefit of the proposed management architecture is the reduction of the complexity through service and data integration. A network management middleware layer that merges low level management functionality with higher level management operations to resolve the problem of heterogeneity was proposed. A prototype was implemented using Web Services and a testbed was developed using trouble ticket systems as the management application to demonstrate the functionality of the proposed framework. Test results show the correcting functioning of the system. It also concludes that the proposed framework fulfils the principles behind the SOA philosophy.
    • Mapping biosphere strontium isotope ratios across major lithological boundaries. A systematic investigation of the major influences on geographic variation in the 87Sr/86Sr composition of bioavailable strontium above the Cretaceous and Jurassic rocks of England.

      Batt, Catherine M.; Heron, Carl P.; Cotton, David E.; Montgomery, Janet; Evans, J.A.; Ander, L.; Warham, Joseph O. (University of BradfordDivision of Archaeological, Geographical and Environmental Sciences (AGES), 2013-02-06)
      Strontium isotope analysis has provided archaeologists with an unprecedented opportunity to study the mobility of humans and animals in the past. However, a lack of systematic environmental baseline data has seriously restricted the full potential of the analytical technique; there is little biosphere data available against which to compare measured skeletal data. This thesis examines the extent to which geographic variation in biosphere 87Sr/86Sr composition can be spatially resolved within the lowland terrain of England, in a geographically and geologically coherent study area. Systematically collected samples of vegetation, stream water and surface soils, including new and archived material have been used. The potential of these sample media to provide reliable estimates of the 87Sr/86Sr composition of bioavailable strontium are evaluated under both high-density and low-density sampling regimes, and against new analyses of local archaeological material. Areas lying south of the Anglian glacial limit, display a pattern of geographic 87Sr/86Sr biosphere variation (0.7080¿0.7105) controlled by solid geology, as demonstrated by high-density biosphere mapping. Data collected at a wider geographic scale, including above superficial deposits, indicate the dominant influence of re-worked local rocks on the biosphere. These methods have enabled a reclassification of the archaeologically important Cretaceous Chalk domain. Analysis of rainwater and other indicators of atmospheric deposition show that, in this setting, local biosphere variation is not significantly perturbed by atmospheric inputs. Time-related data from archaeological cattle and sheep/goat tooth enamel suggest that the modern biosphere data can be used to understand livestock management regimes and that these are more powerful than using an average value from the enamel. A more complete understanding of possible patterns of mobility in a group of humans has been achieved through analysis of material from Winchester and comparison with the Chalk biosphere domain.
    • Masculinities and the Paedophile: Discursive Strategies in Irish Newspapers.

      Featherstone, Brigid M.; Cowburn, I. Malcolm; Galvin, Miriam (University of BradfordDepartment of Social Sciences and Humanities, 2010-03-03)
      This study examines the ways in which men who relate sexually to children, identified in the press as paedophiles, are represented in four leading newspapers in the Republic of Ireland in the period from 2003-2005. Utilising a qualitative research methodology namely critical discourse analysis, a social constructionist approach and informed by post-structural perspectives, this research examines the ways in which the masculinities of the man represented as `the paedophile¿ are constructed. This research demonstrates how the normative is reinforced through the delegitimation of the masculinities of these men. The discursive regimes and cultural scenarios drawn upon in representations of `the paedophile¿ reflect degrees of deviation from hegemonic masculinity in an always already `deviant¿ group of men. Inactive heterosexuality and homosexuality are not hegemonic masculine practices, and the masculinity of supposedly, celibate clergymen and homosexual men is discursively subordinated. A consideration of the material dimensions of these discourses, illustrates how the media representation of men who relate sexually to children, confirms the normative contours of society and strategically excludes hegemonic masculinity and the wider society from association with adult male sexual interaction with children.
    • Mathematical modelling of applied heat transfer in temperature sensitive packaging systems. Design, development and validation of a heat transfer model using lumped system approach that predicts the performance of cold chain packaging systems under dynamically changing environmental thermal conditions.

      Roskoss, Alex; Lakhanpal, Chetan (University of BradfordSchool of Engineering Design and Technology, 2013-12-20)
      Development of temperature controlled packaging (TCP) systems involves a significant lead-time and cost as a result of the large number of tests that are carried out to understand system performance in different internal and external conditions. This MPhil project aims at solving this problem through the development of a transient spreadsheet based model using lumped system approach that predicts the performance of packaging systems under a wide range of internal configurations and dynamically changing environmental thermal conditions. Experimental tests are conducted with the aim of validating the predictive model. Testing includes monitoring system temperature in a wide range of internal configurations and external thermal environments. A good comparison is seen between experimental and model predicted results; increasing the mass of the chilled phase change material (PCM) in a system reduces the damping in product performance thereby reducing the product fluctuations or amplitude of the product performance curve. Results show that the thermal mathematical model predicts duration to failure within an accuracy of +/- 15% for all conditions considered.
    • The meaning of Being as a nurse involved in the work of death investigation. A North American view and its implications to practice in England.

      Lucas, Jeff; Rutty, Jane Elizabeth (University of BradfordSchool of Health Studies, 2012-01-11)
      This research study explored the meaning of ¿Being¿ (i.e. Heidegger¿s four philosophical concepts of Being-in the-world, fore-structures, time and space) as a nurse involved in the work of death investigation in the USA. The objectives were to: reveal the hidden meaning of Being; transfer the findings into an English context by examining what nurses could offer beyond their current role boundaries in an area not currently practised to the extent that nurses make to other medical specialities; and finally put forward developments that would need to take place to ensure such proposals were successful in making an effective difference to health care. In the USA there are two systems of death investigation, the Coronial and Medical Examiner system. The Coroner is an elected county or state position with varied educational and professional requirements. Some Coroner positions have been filled by registered nurses as they have put themselves forward successfully for election. In contrast, the Medical Examiner is an appointed county or state position who must be a licensed physician and a qualified pathologist or forensic pathologist in most cases. Within the Medical Examiner systems death investigators may also be appointed of which some have been filled by registered nurses. It was under the interpretive paradigm that a Heideggerian hermeneutic study was undertaken. Snowball sampling was instigated to reach a hidden population and collect qualitative data by means of unstructured interviews, non-participant observations, interrogation of historical records and the keeping of a personal reflective diary. The seven phase analysis process underpinned by the hermeneutic circle was developed to enable a synopsis of the shared meaning of Being to be revealed through the presentation of paradigm cases that encompass stories and themes. Of the 22 nurses found to be working as either death investigators or Coroners in the USA who fulfilled the inclusion criteria, 17 nurses from 11 States in the USA consented to take part. Fore-structures concerning age (average 37), gender (82% were women) and professional experience (majority came from an adult nursing background with emergency department or critical care experience) are discussed. Overall participants were interviewed for a total of 78 hours in 11 States, five of which were also observed in practice for a total of 142 hours in 3 States, giving a total of 220 hours of interview and observational data. The interpretive analysis revealed the three major paradigms of: the authentic and inauthentic reality of Being (the death investigator nurse in action); the everydayness and averageness of Being (community outreach) and the publicness of Being (mass fatality care). This study reveals knowledge concerning the meaning of Being as a nurse involved in the work of death investigation in the USA. Aspects of this illuminated landscape have propositioned for the advancement of nursing clinical practice to replace and further develop the current coroner¿s officer and soon to be implemented medical examiner officer role in England and Wales. Hence recommendations are made for practice development and further research in England.
    • Measurement properties of respondent-defined rating-scales. An investigation of individual characteristics and respondent choices.

      Reynolds, Nina L.; Wallace, James; Chami-Castaldi, Elisa (University of BradfordSchool of Management, 2012-05-24)
      It is critical for researchers to be confident of the quality of survey data. Problems with data quality often relate to measurement method design, through choices made by researchers in their creation of standardised measurement instruments. This is known to affect the way respondents interpret and respond to these instruments, and can result in substantial measurement error. Current methods for removing measurement error are post-hoc and have been shown to be problematic. This research proposes that innovations can be made through the creation of measurement methods that take respondents¿ individual cognitions into consideration, to reduce measurement error in survey data. Specifically, the aim of the study was to develop and test a measurement instrument capable of having respondents individualise their own rating-scales. A mixed methodology was employed. The qualitative phase provided insights that led to the development of the Individualised Rating-Scale Procedure (IRSP). This electronic measurement method was then tested in a large multi-group experimental study, where its measurement properties were compared to those of Likert-Type Rating-Scales (LTRSs). The survey included pre-validated psychometric constructs which provided a baseline for comparing the methods, as well as to explore whether certain individual characteristics are linked to respondent choices. Structural equation modelling was used to analyse the survey data. Whilst no strong associations were found between individual characteristics and respondent choices, the results demonstrated that the IRSP is reliable and valid. This study has produced a dynamic measurement instrument that accommodates individual-level differences, not addressed by typical fixed rating-scales.
    • Measuring service excellence in banking industry using an integrated approach. An empirical study in the Saudi context.

      Zairi, Mohamed; Al-Rayes, Raed N. (University of BradfordSchool of Management, 2009-10-22)
      The research sought to investigate the Critical Excellence Factors (CEFs) that drive Excellence in banking industry. Moreover, it examines whether customers perceive the service of an excellent bank differently from a less-excellent bank. Three hypotheses were formed then tested through case study and survey strategy (triangulation), within the Saudi banking industry context. The study combines the EFQM excellence model as an internal assessment tool (case studies), with the SERVQUAL gap model for external assessment (questionnaires). Analysing and contrasting the two sets of results allowed the study to achieve its main objective. Based on the empirical work, the study identifies several CEFs that must be carefully considered when driving excellence in banking. These factors were proposed in a generic integrated model for driving Excellence in Banking.
    • Mechanical behaviour and fracture toughness of unfilled and short fibre filled polypropylene both drawn and undrawn. Experimental investigation the effect of fibre content and draw ratio on the mechanical properties of unfilled and short glass fibre filled polypropylene

      Caton-Rose, Philip D.; Alkoles, Omar M.S. (University of BradfordSchool of Engineering, Design and Technology, 2013-03-12)
      The goal of this research is to investigate the combined effects of glass fibre reinforcement and molecular orientation in polypropylene-short glass fibre composites. Specimens have been fabricated using the injection moulding process and drawn using a small die drawing rig. The effects of die drawing on the fibre composites are complex, with the drawing process orienting both the polymer molecules and the glass fibres. This may be accompanied by the creation of voids in the polymer matrix and their destruction in the compressive stress field thus restoring the interfacial contact area between fibre and matrix. Unfilled and short glass fibre filled polypropylene specimens, with fibre content 7% wt, 13%wt, 27%wt, and 55%wt, were injection moulded prior to the die drawing process. An experimental program of die drawing within an oven at elevated temperature was conducted for polypropylene filled to various levels and at different strain rates. The specimens drew to draw ratios in the range ¿=1.41 to ¿=5.6. Mechanical characterization of the test materials has been conducted by examining the tensile stress strain and fracture behaviour under uniaxial conditions. The influence of glass fibre content and drawing conditions (draw ratio) on the fracture toughness and crack propagation was investigated using the double edge notched fracture test. The notch lengths ranged from 1.5 to 2.5 mm for 10 mm wide specimens. The critical stress intensity factor increased as the fibre content increased up to a limiting filler level. The fracture toughness of both unfilled and fibre filled polypropylene were found to be highly dependent on draw ratio. The results were analysed to find out the optimal draw ratio and fibre content that yielded the maximum modulus, strength and fracture toughness. Data showed that, at a given draw ratio, modulus, strength and fracture toughness increased with increasing fibre content to a maximum and then decreased. The optimum material was obtained at a draw ratio of 2.5 and filler loading 13wt%.
    • Mechanical behaviour of fibre reinforced unsaturated clay. This investigation is to determine the improvement in the mechanical behaviour of unsaturated clayey soil after inclusion of carpet fibre waste

      Mohamed, Mostafa H.A.; Saad, Suleiman S.E. (University of BradfordFaculty of Engineering and Informatics, 2016)
      To acquire deeper understanding and insights into the mechanical behaviour of fibre reinforced saturated/unsaturated cohesive soils, a programme of work was designed and included. 1) Conducting standard Consolidation Undrained (CU) tests to investigate mechanical behaviour of non-reinforced fully saturated soil. 2) Studying the strength of fibre reinforced clay though unconfined compression tests. 3) Testing the behaviour of unsaturated reinforced soil in unsaturated triaxial tests. 4) Determining the soil-water characteristic curves (SWCC) on soil sample with different fibre content. The investigation was undertaken on a clay of low plasticity index. Samples tested with addition of 1, 3 and 5 % fibre content and different values of matric suction of 50, 100 and 200 kPa, one of the challenges that were encountered in this research are how to prepare homogenous samples. A method for prepared compacted fibre reinforced soils with improved fibre distribution and density profile has been proposed and examined. The test results indicated that waste carpet fibres increase the shear strength of unsaturated clay soils. It was also found that relative increase in strength is also a function of applied suction. An increase in waste carpet fibres was found to reduce the hysteresis of soil. A data analysis conducted on the results of unsaturated tests as a function of fibre content and matric suction. The behaviour modelled was shown to be a perfect fit with the experimental data.
    • The mechanics of valve cooling in internal-combustion engines. Investigation into the effect of VSI on the heat flow from valves towards the cooling jacket.

      Rosala, George F.; Wright, Steve; Abdel-Fattah, Yahia (University of BradfordSchool of Engineering Design and Technology, 2010-06-14)
      Controlling the temperature of the exhaust valves is paramount for proper functioning of engines and for the long lifespan of valve train components. The majority of the heat outflow from the valve takes place along the valve-seat-cylinder head-coolant thermal path which is significantly influenced by the thermal contact resistance (TCR) present at the valve/seat and seat/head interfaces. A test rig facility and experimental procedure were successfully developed to assess the effect of the valve/seat and seat/head interfaces on heat outflow from the valve, in particular the effects of the valve/seat interface geometry, seat insert assembly method, i.e. press or shrink fit, and seat insert metallic coating on the operating temperature of the valve. The results of tests have shown that the degree of the valve-seat geometric conformity is more significant than the thermal conductivity of the insert: for low conforming assemblies, the mean valve head temperature recorded during tests on copper-infiltrated insert seats was higher than that recorded during tests on noninfiltrated seats of higher conformance. The effect of the insert-cylinder head assembly method, i.e. shrink-fitted versus press-fitted inserts, has proved negligible: results have shown insignificant valve head temperature variations, for both tin-coated and uncoated inserts. On the other hand, coating the seat inserts with a layer of tin (20-22¿m) reduced the mean valve head temperature by approximately 15°C as measured during tests on uncoated seats. The analysis of the valve/seat and seat/head interfaces has indicated that the surface asperities of the softer metal in contact would undergo plastic deformation. Suitable thermal contact conductance (TCC) models, available in the public domain, were used to evaluate the conductance for the valve/seat and seat/cylinder head interfaces. Finally, a FE thermal model of the test rig has been developed with a view to assess the quality of the calculated TCC values for the valve/seat and seat/head interfaces. The results of the thermal analysis have shown that predicted temperatures at chosen control points agree with those measured during tests on thermometric seats with an acceptable level of accuracy, proving the effectiveness of the used TCC models.
    • Mechanisms and consequences of DNA damage, response and apoptosis in spermatozoa.

      Anderson, Diana; Gdula, Michal R.; Laubenthal, Julian (University of BradfordGenetic and Reproductive Toxicology Laboratory, Division of Biomedical Sciences, School of Life Sciences., 2012-01-12)
      DNA damage in spermatozoa is a crucial contributor to spontaneous abortion, severe genetic disease in the offspring and infertility. The chromatin of spermatozoa is highly compacted, transcriptionally and translationally silent, hence lacking DNA damage response (DDR). DDR foci follow within seconds after a DNA double strand break (DSB) and correlate to an abortive topoisomerase-IIb activity during spermiogenesis. When comparing the DSB frequencies at the two most fragile genomic loci (fragile sites FRA3B, FRA16D) in human and murine spermatozoa with lymphocytes, significantly increased DSB levels were detected in spermatozoa in both species. This corroborates that spermatozoa are more prone to DSBs than somatic cells. When comparing the DSB frequencies at FRA3B/FRA16D in spermatozoa of smokers with non-smokers, two-fold increases were found, probably caused by cigarette smoke components triggering abortive topoisomerase-II¿ activity. The phosphorylated DDR proteins H2AX and ATM were identified in human spermatozoa and murine spermatids using multicolour immunostaining with laser-scanning confocal microscopy (LSCM) and Western blots. Based on significantly increased DDR foci in spermatozoa of smoking men, but lacking DDR foci in response to in vitro challenge with H2O2, an abortive topoisomerase-IIb activity is the likely cause of DDR foci in spermatozoa. As DDR foci are susceptible to cigarette smoke, they can potentially be used as a novel biomarker. When comparing paternal spermatozoa, and lymphocytes as well as maternal and cord lymphocytes from 39 families for DSBs (via high-throughput LSCM pH2AX detection) and DNA fragmentation (Comet assay), significant increases were found in newborns of mothers exposed to environmental tobacco smoke and smoking fathers. When challenging lymphocytes and spermatozoa to different genotoxicants, significantly increased DNA damage in newborns compared to adults was found. This confirms an exceptional vulnerability in newborns, believed to cause increased susceptibly to disease in later life, including cancer.
    • Mechanisms of epigenetic regulation in epidermal keratinocytes during skin development. Role of p63 transcription factor in the establishment of lineage-specific gene expression programs in keratinocytes via regulation of nuclear envelope-associated genes and Polycomb chromatin remodelling factors.

      Botchkarev, Vladimir A.; Fessing, Michael Y.; Rapisarda, Valentina
      During tissues development multipotent progenitor cells establish tissue-specific gene expression programmes, leading to differentiation into specialized cell types. It has been previously shown that the transcription factor p63, a master regulator of skin development, controls the expression of adhesion molecules and essential cytoskeleton components. It has also been shown that p63 plays an important role in establishing distinct three-dimensional conformations in the Epidermal Differentiation Complex (EDC) locus (Fessing et al., 2011). Here we show that in p63-null mice about 32% of keratinocytes showed altered nuclear morphology. Alterations in the nuclear shape were accompanied by decreased expression of nuclear lamins (Lamin A/C and Lamin B1), proteins of the LINC complex (Sun-1, nesprin-2/3) and Plectin. Plectin links components of the nuclear envelope (nesprin-3) with cytoskeleton and ChIP-qPCR assay with adult epidermal keratinocytes showed p63 binding to the consensus binding sequences on Plectin 1c, Sun-1 and Nesprin-3 promoters. As a possible consequence of the altered expression of nuclear lamins and nuclear envelope-associated proteins, changes in heterochromatin distribution as well as decrease of the expression of several polycomb proteins (Ezh2, Ring1B, Cbx4) has been observed in p63-null keratinocytes. Moreover, recent data in our lab have showed that p63 directly regulates Cbx4, a component of the polycomb PRC1 complex. Here we show that mice lacking Cbx4 displayed a skin phenotype, which partially resembles the one observed in p63-null mice with reduced epidermal thickness and keratinocyte proliferation. All together these data demonstrate that p63-regulated gene expression program in epidermal keratinocytes includes not only genes encoding adhesion molecules, cytoskeleton proteins (cytokeratins) and chromatin remodelling factors (Satb1, Brg1), but also polycomb proteins and components of the nuclear envelope, suggesting the existence of a functional link between cytoskeleton, nuclear architecture and three dimensional nuclear organization. Other proteins important for proper epidermal development and stratification, are cytokeratins. Here, we show that keratin genes play an essential role in spatial organization of other lineage-specific genes in keratinocytes during epidermal development. In fact, ablation of keratin type II locus from chromosome 15 in epidermal keratinocytes led to changes in the genomic organization with increased distance between the Loricrin gene located on chromosome 3 as well as between Satb1 gene located on chromosome 17 and keratin type II locus, resulting in a more peripheral localization of these genes in the nucleus. As a possible consequence of their peripheral localization, reduced expression of Loricrin and Satb1 has also been observed in keratins type II-deficient mice. These findings together with recent circularized chromosome conformation capture (4C) data, strongly suggest that keratin 5, Loricrin and Satb1 are part of the same interactome, which is required for the proper expression of these genes and proper epidermal development and epidermal barrier formation. Taken together these data suggest that higher order chromatin remodelling and spatial organization of genes in the nucleus are important for the establishment of lineage-specific differentiation programs in epidermal progenitor cells. These data provide an important background for further analyses of nuclear architecture in the alterations of epidermal differentiation, seen in pathological conditions, such as psoriasis and epithelial skin cancers.
    • Mechanisms responsible for homocysteine mediated damage to human endothelial cells : the role of oxidative stress in atherogenesis.

      Graham, Anne M.; Parkin, Susan M.; Alkhoury, Kenan (University of BradfordSchool of Life Sciences, 2010-05-14)
      Homocysteine (Hcy) has been identified as a primary risk factor for atherosclerosis as it induces endothelial cell (EC) activation/dysfunction and thus potentially initiating atherosclerotic plaque formation. There is accumulating evidence indicating a key role for oxidative stress in mediating Hcy atherogenic effects. The aim of this study was to evaluate the effects of chronic treatment with Hcy on EC activation and to explore the role of oxidative stress in these effects. Human umbilical vein endothelial cells (HUVEC) were cultured and treated chronically with DL-Hcy for 5-9 days. An in vitro flow system was also used to characterize the different types of interactions between DL-Hcy-treated HUVEC and neutrophils under physiological flow conditions. EC activation was studied by characterizing the activation of the JNK pathway and the up-regulation of different cell adhesion molecules (CAM) and cytokines, using different techniques including western blot, immunohistochemical staining, enzyme-linked immunosorbent assay and polymerase chain reaction. The role of oxidative stress was investigated by measuring the production of ROS and evaluating the efficiency of antioxidants. Furthermore, the role of nitric oxide and nitric oxide synthase in modulating Hcy effects was investigated. Chronic treatment with DL-Hcy did not kill the EC however, it inhibited cell proliferation. Furthermore, this treatment induced EC activation/dysfunction which was characterized by sustained activation of the JNK pathway, which in turn mediated up-regulation of E-selectin, ICAM-1 and to lesser extent P-selectin. Furthermore, DL-Hcy induced production of IL-8 protein. These CAM and chemokines collectively mediated different interactions between DL-Hcy-treated HUVEC and neutrophils under flow conditions including tethering, rolling, adherence and transmigration. DL-Hcy was also shown to induce significant ROS generation which mediated activation of the JNK pathway. Antioxidants restored DL-Hcy-induced interactions under flow to the basal level. DL-Hcy was shown to induce eNOS uncoupling which mediated, at least in part, the DL-Hcy-induced ROS production. Furthermore, short term treatment with NO inhibited DL-Hcy-induced HUVEC:neutrophil interactions in a cGMP-independent manner. In summary, this research showed that DL-Hcy has several proatherogenic effects, mediated at least in part by the JNK pathway, and induces EC activation/dysfunction priming for atherosclerosis initiation. The data supports that oxidative stress mediates the majority of Hcy atherosclerotic effects. Antioxidants tested, JNK inhibitors and NO showed promising results in reversing all DL-Hcy effects and restoring EC normal status. ¿
    • Mechanistic approaches towards understanding particle formation in biopharmaceutical formations. The role of sufactant type and level on protein conformational stability, as assessed by calorimetry, and on protein size stability as assessed by dynamic light scattering, micro flow imaging and HIAC

      Forbes, Robert T.; Hulse, W.L.; Vaidilaite-Pretorius, Agita (University of BradfordFaculty of Life Sciences, 2013)
      Control and analysis of protein aggregation is an increasing challenge to biopharmaceutical research and development. Therefore it is important to understand the interactions, causes and analysis of particles in order to control protein aggregation to enable successful biopharmaceutical formulations. This work investigates the role of different non-ionic surfactants on protein conformational stability, as assessed by HSDSC, and on protein size stability as assessed by Dynamic Light Scattering (DLS), HIAC and MFI. BSA and IgG2 were used as model proteins. Thermal unfolding experiments indicated a very weak surfactant-immunoglobulin IgG2 interaction, compared to much stronger interactions for the BSA surfactant systems. The DLS results showed that BSA and IgG2 with different surfactants and concentration produced different levels of particle size growth. The heat treatment and aging of samples in the presence of Tween 20, Tween 80, Brij 35 and Pluronic F-68 surfactants led to an increase in the populations of larger particles for BSA samples, whereas IgG2 systems did not notably aggregate under storage conditions MFI was shown to be more sensitive than HIAC technique for measuring sub-visible particles in protein surfactant systems. Heat treatment and storage stress showed a significant effect on BSA and IgG2 protein sub-visible particle size stability. This work has demonstrated that both proteins with different Tween 20, Tween 80, Brij 35 and Pluronic F-68 concentrations, have different level of conformational and size stability. Also aging samples and heating stress bears the potential to generate particles, but this depends on surfactant type. Poor predictive correlations between the analytical methods were determined.
    • Mechanistic Insights into the Stabilisation of Biopharmaceuticals using Glycine Derivatives. The Effect of Glycine Derivatives on the Crystallisation, Physical Properties and Behaviour of Commonly used Excipients to Stabilise Antigens, Adjuvants and Proteins in the Solid State

      Isreb, Mohammad; Bright, Andrew G. (University of BradfordSchool of Pharmacy, Faculty of Life Sciences, 2015)
      This dissertation has focused on studying the effect of four glycine derivatives on the solid state properties of mannitol, glycine, and sucrose when freeze dried into blended mixtures. The primary goal was to assess their value for use in the stabilisation of vaccines in the solid state, by examining key physical and chemical characteristics, which have been documented to be beneficial to the stabilisation of biopharmaceutical formulations. The novel excipients; dimethyl glycine, and trimethyl glycine, were shown to retard the crystallisation and increase the overall glass transition temperature, of mannitol, when freeze dried as evidenced by DSC and Powder X-ray diffraction. Mannitol’s glass transition temperature increased from 100C to 12.650C and 13.610C when mixed with methyl-glycine and dimethyl glycine respectively. The glycine derivatives did not show the same effect on sucrose which remained amorphous regardless of the concentration of the other excipient. The different behaviour with the sucrose system was thought to be due to relatively high glass transition temperature of sucrose. Conversely glycine remained highly crystalline due it’s relatively low glass transition temperature. The novel excipient formulations were also assessed for their effect on the aggregation of the adjuvant aluminium hydroxide when freeze dried by Dynamic Light Scattering (DLS).The formulations containing the glycine derivatives all caused a decrease in the aggregation size of the adjuvant from ~26 μm, to 185 nm in the presence of methyl glycine. The effects of lysozyme and viral antigen on the adjuvants were also examined showing that the addition of the virus did not affect the size of the aggregates formed, however lysozyme showed significant decreases in the aggregates formed. Examination of the freezing method were also made showing that faster freezing rates produced smaller aggregates of the adjuvant. When investigating the rate at which the excipients lost water during secondary drying there was evidence of the formation of hydrates of glycine, trimethyl glycine, and mannitol has shown that the glycine derivatives have attributes which would be beneficial in stabilising vaccines in the solid state when freeze dried.