• The effect of synthetic cannabinoids and their combination with TGF-β3 on wound healing of cell cultured human bone cell monolayers and 3D models. The role of synthetic cannabinoid HU308 and HU308/TGF-β3 combinations on cellular adhesion, proliferation, wound healing, nitric oxide, MMP-2 and ECM protein regulation of MG-63 osteoblast monolayers and 3D models

      Youseffi, Mansour; Denyer, Morgan C.T.; Genedy, Mohamed A. (University of BradfordDivision of Medical Engineering, School of Engineering, Design and Technology, 2014-05-07)
      Despite the ongoing political debate regarding the legality of medical marijuana, clinical investigations of the therapeutic use of cannabinoids are now more prevalent than at any time in history. Cannabinoids have been shown to have analgesic, anti-spasmodic, anticonvulsant, anti-tremor, anti-psychotic, anti-inflammatory, anti-oxidant, anti-emetic and appetite-stimulant properties. There are mainly two well-known cannabinoid receptors, CB1 and CB2, located in the central (CB1) and peripheral (CB2) nervous systems as well as the immune system. More recently, endocannabinoids (ligands) and their receptors have also been found in the skeleton which appear as the main body system and physiologically regulated by CB2. This study aimed to examine the effect of both CB1 and CB2 receptor stimulation on wound closure response of MG-63 osteoblast bone cell monolayers using different treatments with cannabinoid such as Winn55,212-2, URB602 and HU308. Also, cell adhesion, cell proliferation and cell length was investigated. The study also aimed to examine the effect of HU308 treatments in combination with TGF-β3 (transforming growth factor beta -3) on wound healing, cell adhesion and extracellular matrix up regulation (collagen type I, fibronectin and protien S-100A6) as well as other biological factors such as secretion of matrix metalloproteinase (MMP-2) and nitric oxide (NO). Finally, this study investigated HU308/TGF-β3 combination treatment on the regulation of extracellular matrix (collagen type I, fibronectin and protien S-100A6) in a 3D multilayer system of MG-63 osteoblast bone cells. Wound healing assays of MG-63 monolayers revealed accelerated wound repair as well as increased cell proliferation mainly regulated through CB2 receptors, and that treatments with HU308 and HU308/TGF-β3 achieved minimum closure timings compared with control groups (P<0.05). Our finding suggested that proliferation rate with 500nM HU308 was significantly higher than control and TGF-β3/HU308 combination groups (P<0.05). Interestingly, percentage of wound remained open after 15 hours for combination groups was 17.6%±1.32 whereas treatment with 500nM HU308 had 20%±2.25 indicating that the combination groups took the lead throughout wound healing. It was also observed that bridge formation in all treatment groups was taking place between 15 to 20 hour periods whereas within control treatments bridge formation started to take place after 25 hours. Cell surface attachment was examined via the trypsinization assay in which the time taken to trypsinize cells from the surface provided a means of assessing the strength of attachment. The results indicated that higher concentrations of HU308 (2μM), induced significant force of cell attachment compared with control and concentrations of 500nM and 1μM (P<0.05). However, groups treated with TGF-β3 and combination HU308/TGF-β3 indicated reduced cell surface attachment compared with control groups, indicating enhanced cell migration. Immunofluorescence staining as well as Elisa based semi-quantification technique indicated that both collagen type I and fibronectin were unregulated using higher concentrations of HU308 with decreased cell proliferation compared to lower concentrations. Nevertheless, protein S-100A6 was up-regulated in treatments with HU308, TGF-β3 and their combination HU308/TGF-β3 (P<0.05), indicating the positive role of these treatments in promoting cell differentiation. MMP-2 levels in the current study were also shown to be concentration-dependent, i.e. higher concentrations of HU308 significantly reduced MMP-2 secretion leading to decreased cell migration, while HU308/TGF-β3 combination treatment increased MMP-2 levels, indicating an increase in cell migration. The current study also examined levels of nitric oxide synthesis in relation to different treatments with HU308, TGF-β3 and HU308/TGF-β3 combination. It was found that nitric oxide up-regulation influences rate of MG-63 osteoblast wound healing in a concentration dependent manner. Lastly, UpCell culture dishes proved to have efficacy in obtaining a multilayer model of MG-63 osteoblast system in-vitro through changes in cell morphology. It was also found that treatments with HU308, TGF-β3 and HU308/TGF-β3 combination influenced collagen type I, fibronecton and protein S-100A6 secretion. These findings supported the earlier Elisa based semi-quantification results obtained for monolayer cultures.
    • The effect of synthetic cannabinoids on wound healing of chondrocytes monolayers and pseudo 3D cartilage tissue. Effect of different concentrations of synthetic cannabinoids WIN55, 212-2, URB602 and HU-308 with and without their antagonists on wound healing of chondrocyte monolayers and pseudo 3D cartilage tissue.

      Youseffi, Mansour; Denyer, Morgan C.T.; Abdeldayem, Ali I.A. (University of BradfordDivision of Medical Engineering, School of Engineering, Design and Technology, 2014-05-07)
      Studies have been conducted to highlight the anti-inflammatory and immunosuppressive properties of cannabinoids and also their potentials for cartilage repair and regeneration. Various wound healing techniques can be used to investigate the mechanisms of chondrocyte repair in monolayers or three dimensional tissue constructs. The effect of different concentrations of the synthetic cannabinoids WIN55, 212-2 (WIN-2), URB602 and HU-308 with and without their antagonists on the wound healing of chondrocyte monolayers was investigated using a simple scratch assay model. The three cannabinoids were found to increase wound healing of chondrocyte monolayers, but at different rates. WIN55, 212-2 at a concentration of 1μM had the highest effect of increasing both migration and proliferation of chondrocytes cultured in a chondrogenic media, which increased the rate of wound closure. It was also found that treating the cells with 2μM of any of the cannabinoids lead to a decrease in cell proliferation and the rate of wound closure. These findings were further investigated, by studying the effect of WIN-2 on nitric oxide (NO) and matrix metalloproteinase-2 (MMP-2) expressed by wounded chondrocyte monolayers. Moreover, expression of collagen type-I, collagen type-II, fibronectin and S100 proteins were detected using immunofluorescence and verified quantitatively using ELISA based techniques, following treatment with 1μM and 2μM of WIN-2, for both 2D monolayers and 3D sheets. Treating chondrocytes with 1μM of WIN-2 significantly increased collagen type-II, fibronectin and S100, and significantly reduced collagen type-I compared to control groups in monolayers and chondrocyte cell sheets. On the other hand, both concentrations of WIN-2 significantly reduced the expression of the inflammation markers NO, and MMP-2, in a dose dependent manner. These findings highlight the potential use of the synthetic cannabinoid for improving the rate of wound closure as well as acting as an antiinflammatory agent, which could be used to enhance tissue engineering protocols aimed at cartilage repair.
    • Effect of the Muslim Headscarf on Face Perception. A series of psychological experiments looking at how the Muslim headscarf influences the perception of (South Asian) faces.

      Keeble, David R.T.; Bryant, Eleanor J.; Horrocks, Christine; Toseeb, Mohammed U. (University of BradfordBradford School of Optometry and Vision Science, 2013-04-05)
      The Muslim headscarf conceals the hair and other external features of a face. For this reason it may have implications for the recognition of such faces. The experiments reported in this thesis aimed to investigate anecdotal reports, which suggested that headscarf wearing females are more difficult to recognise. This was done by employing a series of experiments which involved a yes/no recognition task. The stimuli that were used were images of South Asian females who were photographed wearing a Muslim headscarf (HS), with their own hair visible (H), and a third set of stimuli were produced in which their external features were cropped (CR). Most importantly, participants either took part in the condition in which the state of the external features remained the same between the learning and test stage (Same) or the condition in which they were switched between the two stages (Switch). In one experiment participants completed a Social Contact Questionnaire. Surprisingly, in the Same condition, there was no difference in the recognition rates of faces that were presented with hair, with headscarf, or cropped faces. However, participants in the Switch condition performed significantly worse than those in the Same condition. It was also found that there was no difference in the % of fixations to the external features between the Same and Switch condition, which implied that the drop in performance between the two conditions was not mediated by eye-movements. These results suggest that the internal and external features of a face are processed interactively and, although the external features were not fixated on, a manipulation to them caused a drop in performance. This was confirmed in a separate experiment in which participants were unable to ignore the external features when they were asked to judge the similarity of the internal features of pairs of faces. Pairs of headscarf faces were rated as being more similar compared to pairs of faces with hair. Finally, for one group of participants it was found that contact with headscarf-wearing females was positively correlated with the recognition of headscarf-wearing faces. It was concluded that the headscarf per se did not impair face recognition and that there is enough information in the internal features of a face for optimal recognition, however, performance was disrupted when the presence or absence of the headscarf was manipulated.
    • Effect of vehicle type on highway traffic flow: Effects of vehicle type on speed, delay and capacity characteristics of highway traffic flow in the United Kingdom and Saudi Arabia determined by an examination of traffic data.

      Salter, R.J.; Alkaim, Al-Akhdar (University of BradfordPostgraduate School of Studies in Civil and Structural Engineering, 2009-10-22)
      The t h e s i s c o n s i d e r s t h e e f f e c t s of v e h i c l e type on highway t r a f f i c flow. The e f f e c t s of v e h i c l e type on t h e c a p a c i t y of t r a f f i c s i g n a l approaches are examined by t h e experimental d e t e r m i n a t i o n of passenger c a r u n i t s a t i n t e r s e c t i o n s i n London and West Yorkshire and i n a d d i t i o n s a t u r a t i o n flows and lost t i m e s a r e examined. . Vehicle type e f f e c t s a t roundabout e n t r i e s a r e i n v e s t i g a t e d and t h e r e s u l t s of f i e l d o b s e r v a t i o n s r e p o r t e d . Details a r e given of t h e gap acceptance of varying v e h i c l e t y p e s , t h e e f f e c t of v e h i c l e type on delay and comparisons a r e made with e x i s t i n g recommendat i o n s f o r t h e c a p a c i t y design of roundabout e n t r i e s . Observations of t r a f f i c flow on a r u r a l motorway a r e used to demonstrate t h e e f f e c t of v e h i c l e type on speed and observed v a l u e s a r e f i t t e d t o a normal d i s t r i b u t i o n . Overtaking behaviour is a l s o examined and conclusions drawn of t h e r e l a t i v e e f f e c t on c a p a c i t y of v e h i c l e t y p e . A review is given of t h e e f f e c t s of v e h i c l e type on t h e design and o p e r a t i o n of t h e highway system in Saudi Arabia.
    • The Effect of Wall Jet Flow on Local Scour Hole

      Hussain, Khalid; Tait, Simon J.; Ghoma, Mohamed I. (University of BradfordSchool of Engineering Design and Technology, 2013-02-06)
      This thesis reports on investigations carried out to study of the effect of horizontal wall jets on rough, fixed and mobile beds in open channel flow. Experimental tests were carried out, using fixed and mobile sediment beds. Computer simulation models for the flow within the jet and resulting sediment transport were developed and their results analysed in this study. In the experimental phase, tests were carried out with both fixed and mobile sediment beds. The shape of the water surface, numerous point velocity measurements and measurements of the evolving scour hole shape were made. Detailed descriptions of the turbulent flow field over a fixed rough bed and for scour holes at equilibrium were obtained for a range of initial jet conditions. Fully turbulent, multiphase flow was modelled using the Fluent Computational Fluid Dynamics software. This was used to analyze the flow caused by a jet in a rectangle open-channel with a rough bed, and also the flow pattern in a channel with a local scour hole. The volume of fluid (VOF) multiphase method and K- model was used to model the fluid flow in both cases. The model predictions of velocity and shear stress were compared against experimental observations. The experimental data was used to develop new empirical relationships to describe the pattern of boundary shear stress caused by a wall jet over fixed beds and in equilibrium scour holes. These relationships were linked with existing bed-load transport rate models in order to predict the temporal evolution of scour holes. An analytical model describing the relationship between the wall jet flow and the development of a local scour hole shape was reported and its predictions compared with experimental data.
    • The effect of water policy implementation at the local community in Zambia: Examining the role of national and local institutions concerning Zambezi

      Anand, Prathivadi B.; Analoui, Farhad; Kabeya, Patrice K. (University of BradfordBradford Centre for International Development (BCID), Faculty of Social Sciences., 2014)
      To capture the ‘real world’ experience of institutions and policy within the Zambezi rural basin, the study highlights differences in perceptions of the policy and institutions of the water sector between those involved in management of the water sector and those using water for their livelihoods. The study is situated within the qualitative paradigm; its unit of analysis is the participants (members of households, policy makers and members of the Village Water Committee). The study has applied a grounded theory methodology (semi-structured interviews). Forty participants were interviewed in the Zambezi rural basin. The research highlights that, the National Water Supply and Sanitation Council as a national regulatory institution has not yet fully provided support in terms of regulatory framework that would enable the rural water sector to sustain the demand of the Zambezi rural basin of Zambia. Despite this, the National Water Supply and Sanitation Council have made some key progress in developing the suitable guidelines within the regulatory framework significant in the management of water sector. The study indicates that institutions such as the Village Water Committee are considered to be crucial for strengthening the water sector in the Zambezi rural basin if given a suitable legal status for its operational water activities. Furthermore, water supply and demand disparity among households in the Zambezi rural basin remains a challenge to be addressed. The study further highlights policy and institutions in terms of their effects on the quality of water and health status of households remain a major concern for the citizens.
    • Effective people performance strategies : critical ingredients for business success in Barbados and Eastern Caribbean business enterprises.

      Ostell, Alistair; Richards, Hartley B. (University of BradfordSchool of Management, 2010-05-14)
      Today, the effective management of people is assuming prominence as a source of sustained business performance improvement. The rationale for this trend is that other significant aspects of business, such as marketing, new technology, market niche, trademarks and brand image have generally been mastered. Therefore, business enterprises are being encouraged in seeking to gain comparative advantage by reliance on their human resources because this aspect of business is arguably more difficult to imitate or understand than the more conventional resources. As a result, there is an awakening of the need to introduce management practices that will concentrate on the added value which a highly motivated work force may provide to the organisation. The idea of added value from a highly motivated work force assumes even greater significance when the main business hinges almost entirely on the attitudes and approaches of people. This concept applies most forcibly to Barbados and the Organisation of Eastern Caribbean States (BOECS), the region covered by this study. This research therefore, explores the idea of gaining comparative advantage through appropriate people management methods and follows the trend in the developed and more industrialised nations of the world in an effort to determine whether there is a useful model of effective management practices which may be replicated in the BOECS and thus lead to improved business performance in the micro states which constitute this ii region. However, this study is mindful of the limitations of the research methodology which a vast number of contributors to this intriguing topic have employed. Nevertheless, this exploratory attempt examines the issue in the light of its possible positive effect on a previously uncharted area, viz., Barbados and the Eastern Caribbean (BOECS) as far as it relates to scholarly treaties on Human Resource Management. The idea is that even in the absence of clear unequivocal empirical evidence about its benefits, it may be useful to pursue the strategic approach to Human Resource Management including expansion of employee involvement, for it own sake.
    • The Effectiveness of Pharmacist Interventions in Improving Asthma Control and Quality of Life in Patients with Difficult Asthma

      Blenkinsopp, Alison; Morgan, Julie D.; Silcock, Jonathan; Clifton, I.J.; Capstick, Toby G.D. (University of BradfordSchool of Pharmacy, Faculty of Life Sciences, 2014)
      Despite national guidelines, the management of difficult asthma remains suboptimal, and there may be opportunities for pharmacists to improve asthma outcomes. This six-month prospective, randomised, open study investigated the effects of pharmaceutical care across primary and secondary care on difficult asthma. Fifty-two patients attending a hospital difficult asthma clinic were randomised (1:1) to receive usual medical care (UC), or pharmacist interventions (PI) comprising asthma review, education, and medicines optimisation from a hospital advanced clinical pharmacist, plus follow-up targeted Medicines Use Review (t-MUR) from community pharmacists. Forty-seven patients completed the study. More interventions were performed in the PI group at baseline (total 79 vs. 34, p<0.001), but only six patients received a t-MUR. At six-months, PI were non-inferior to UC for all outcomes. The primary outcome measure was Juniper’s Asthma Control Questionnaire score and reduced (improved) from a median (IQ) score of 2.86 (2.25, 3.25) and 3.00 (1.96, 3.71) in the PI and UC groups respectively to 2.57 (1.75, 3.67) and 2.29 (1.50, 3.50). At baseline, 58.8%, 46.9% and 17.6% of patients had optimal inhaler technique using Accuhalers, Turbohalers or pMDIs; education improved technique but this was not maintained at six-months. Adherence rates <80% were observed in 57.5% of patients at baseline, and was improved in the PI group at six-months (10/20 PI vs. 3/21 UC had adherence rates of 80-120%, p=0.020). This study demonstrates that the management of difficult asthma by specialist pharmacists is as effective as usual medical care. Future research should investigate whether pharmacist-led follow-up produces further improvements.
    • The Effects of Binocular Vision Impairment on Adaptive Gait. The effects of binocular vision impairment due to monocular refractive blur on adaptive gait involving negotiation of a raised surface.

      Elliott, David B.; Buckley, John G.; Vale, Anna (University of BradfordDepartment of Optometry, 2011-07-06)
      Impairment of stereoacuity is common in the elderly population and is found to be a risk factor for falls. The purpose of these experiments was to extend knowledge regarding impairment of binocular vision and adaptive gait. Firstly using a 3D motion analysis system to measure how impairment of stereopsis affected adaptive gait during a negotiation of a step, secondly by determining which clinical stereotest was the most reliable for measuring stereoacuity in elderly subjects and finally investigating how manipulating the perceived height of a step in both binocular and monocular conditions affected negotiation of a step. In conditions of impaired stereopsis induced by acutely presented monocular blur, both young and elderly subjects adopted a safety strategy of increasing toe clearance of the step edge, even at low levels of monocular blur (+0.50DS) and the effect was greater when the dominant eye was blurred. The same adaptation was not found for individuals with chronic monocular blur, where vertical toe clearance did not change but variability of toe clearance increased compared to full binocular correction. Findings indicate stereopsis is important for accurately judging the height of a step, and offers support to epidemiological findings that impaired stereoacuity is a risk for falls. Poor agreement was found between clinical stereotests. The Frisby test was found to have the best repeatability. Finally, a visual illusion that caused a step to be perceived as taller led to increased toe elevation. This demonstrates a potential way of increasing toe clearance when stepping up and hence increase safety on stairs.
    • The effects of individual, organizational and environmental factors on the adoptions of e-commerce by SMEs in the Netherlands. An examination of factors influencing managerial beliefs, attitudes and the use of an e-commerce system using the technology acceptance model.

      Not named; Castricum, Marc C. (University of BradfordSchool of Management, 2015-06-04)
      Since the 1990s the use of the Internet and electronic commerce (e-commerce) has exploded, yet few SMEs seem to benefit from its potential. The lack of personal involvement and low level of use are an indication that managers still have not committed themselves to e-commerce. Consequently they are not reaping the full benefits first hand. The objectives of the study are to identify key factors and relationships likely to influence e-commerce use by SME managers in the Netherlands and to investigate whether relevant and significant factors can be combined in a new model to predict how SME managers will use new technology. To achieve these objectives, a well-established model of IT usage behaviour, the Technology Acceptance Model (TAM), was used. Building upon TAM, a theoretical research model was developed to investigate a large number of external variables that are possible antecedents of managerial beliefs, attitudes, and the use of IT. E-commerce systems were chosen as the IT tool under review. A cross-sectional field survey was conducted to investigate the theoretical research model. The results are based on the analysis of questionnaire data from 114 managers from Dutch SMEs. Using Structural Equation Modelling (SEM) the results show significant support for external variables, mostly of an individual nature, in the categories of demographics, managerial and IT knowledge, individual characteristics, and company characteristics. Contrary to expectations, two categories - social factors and environmental characteristics - had few or no variables with a significant relationship. This study further presents empirical evidence to suggest a limited number of antecedents under managerial control influencing beliefs, attitudes, and use. A better understanding of the various factors that may impede or increase effective utilization of IT can facilitate the design of organizational or managerial interventions that address these issues. Building on the core TAM model a new model, the e-Tam Model, has been developed based on the results of the theoretical research model. In this model, it is hypothesized that IT usage is directly and indirectly influenced by seven external variables divided into three categories: demographics, personality, and company characteristics. Using the e-Tam Model, effective and increased use of managerial IT tools can be promoted. This will enable managers to have a better use of e-commerce systems leading in turn to better margins and opportunities.
    • The effects of lime on the decomposition of buried human remains. A field and laboratory based study for forensic and archaeological application.

      Wilson, Andrew S.; Janaway, Robert C.; Schotsmans, Eline M.J. (University of BradfordDepartment of Archaeological Sciences, School of Life Sciences., 2014-05-02)
      The inclusion of lime in burials is observed in historical and archaeological records, in contemporary mass graves and forensic cases. Clearly there are controversies within the literature and there is a general misconception of the effects of lime on decomposition. Recent casework in Belgium and the UK involving the search for human remains buried with lime, have demonstrated the need for a more detailed understanding of the effect of different types of lime on cadaver decomposition and its micro-environment. Field and laboratory experiments using pigs as human body analogues were undertaken to obtain a better understanding of the taphonomic processes that govern lime burials. The changes observed in the experiments were related back to archaeological parallels in which white residues have been found. The combined results of these studies demonstrate that despite conflicting evidence in the literature, hydrated lime and quicklime both delay the initial stages of the decay process but do not arrest it completely. The end result is ultimately the same: skeletonisation. Furthermore this study stresses the importance of the specific microenvironment in taphonomic research and highlights the need for chemical analysis of white residues when encountered in a burial. Not all white powder is lime. White residue could be identified as calcium carbonate, building material, body decomposition products, minerals or degraded lead. This study has implications for the investigation of clandestine burials and for a better understanding of archaeological plaster burials. Knowledge of the effects of lime on decomposition processes also have bearing on practices involving the disposal of animal carcasses and potentially the management of mass graves and mass disasters by humanitarian organisation and DVI teams.
    • Effects of Rear Bumper Beam Deletion on the Perception of Steering Performance of Commercial Vehicles

      Day, Andrew J.; Hussain, Khalid; Banks, Alan J. (University of BradfordFaculty of Engineering and Informatics Bradford Programme of Engineering Quality Improvement, 2015)
      In order to remain competitive in the marketplace, all motor vehicle manufacturers face difficult decisions with regard to balancing cost vs. feature. That is to say that the manufacturer must balance the cost of the product to the customer to remain competitive whilst offering appropriate technology and standard features required by that customer. All motor manufacturers are therefore under pressure to keep costs of nonfeature items to a minimum. One of the cost reductions items prevalent on most vehicles is the deletion of the structural member that attaches the rear bumper, known as the bumper beam (RBB), which is researched in this Thesis. This generates average vehicle savings of $20 and, as this is invisible to the customer, should enable the manufacturers to realise a significant saving or allow this revenue to be spent on additional feature without loss of vehicle function. However, in nearly all cases, deletion of the rear bumper beam has the effect of degrading the steering responses of the vehicle by 1 to 1½ rating points (out of 10), which is contrary to the premise of cost reductions; which is to ensure that vehicle function is unaffected. Initial analysis of vehicles with deleted rear bumper beams cannot show an objective measurable difference in any vehicle behaviours with or without the beam fitted, and hence CAE studies using ADAMS models cannot verify the effects of the bumper beam. It was necessary to employ unconventional modelling and testing methods such as rigid body, flexible body model techniques as well as experimental studies included driving robots and expert driver appraisals. The research demonstrated that vehicle modelling methods currently used, cannot establish or predict the complete vehicle ride and handling status. A total vehicle model approach should be used without separating the body CAE model and vehicle dynamics ADAMS model into separate entities. Furthermore, it was concluded that the determination to the effects of body hysteresis rather than pure stiffness is of crucial importance and that the steering attribute could be maintained with the deletion of the RBB analytically.
    • The effects of TGF-β on the behaviour of a keratinocyte cell line: implications in wound repair

      Denyer, Morgan C.T.; Youseffi, Mansour; Berends, Rebecca F. (University of BradfordSchool of Life Sciences, 2012-02-29)
      TGF-β isoforms are important signalling molecules in wound repair in the skin. Transforming growth factor β3 (TGF-β3) has been implicated in scarless healing. In both animal and human models the application of exogenous TGF-β3 causes a reduction in the inflammatory response and improves the architecture of the neodermis. Research into the influence of TGF-β on scarring has tended to focus on fibroblasts. However, keratinocytes play a major role in scarring both indirectly, as a result of their influence over the behaviour of fibroblasts and also by directly influencing wound contraction. Thus, experiments were carried out to investigate the influence of TGF-β3 on the behaviours of a keratinocyte cell line (HaCaT). Incubation with TGF-β3 increased cell spreading and appeared to reduce cell-surface contacts indicated by both SPR imaging and a detachment assay. TGF-β3 also caused a decreased cell alignment response to microcontact printed protein patterns, in part due to the deposition of laminin which is associated with the TGF-β induced cell migration. There is evidence that TGF-β isoforms differentially influence the outcome of wound healing. Similar to the results produce following addition of exogenous TGF-β3, the neutralisation of TGF-β1 and 2 has been shown to reduce scar formation in the adult wounds. During reepithelialisation keratinocytes experience a dynamic environment. Both extracellular matrix proteins and growth factors influence the progression of wound repair which includes both cell migration and proliferation. Few studies have examined collective cell behaviour in response to TGF-β isoforms and ECM coated substrates. Thus both wound closure and cell proliferation assays were conducted for different ECM proteins fibronectin, laminin and collagen type I and for TGF-β1, 2 and 3. Rates of wound closure were significantly reduced on laminin coated substrates while cell proliferation rates were increased. TGF-β2 and 3 induced significant increases in wound closure rates. This appeared to correspond with an increase in the number of cells independently migrating out from the wound margins. Only TGF-β3 caused a significant decrease in cell proliferation over a 4 day period. Laminin332 deposition is central to the reepithelialisation process and is known to be induced in response to TGF-β. Thus experiments were carried out to investigate HaCaT cell laminin332 deposition in response to TGF-β1, 2 and 3. Both an immunofluorescence staining technique and an ELISA based semi-quantification method was used. Following 4 day incubation all TGF-β isoforms significantly increased laminin332 deposition; however TGF-β2 and 3 caused the most significant increases. Integrin receptors enable cell-matrix interactions during wound repair. TGF-β is known to influence the expression of integrin subunits. Thus, experiments were carried out to compare the influence of each TGF-β isoform on the expression of subunits α3, α2, α5, β1 and β4. All TGF-β isoforms significantly increased all subunit expression. TGF-β3 caused the most significant increase in β4 and both TGF-β2 and 3 caused the most significant increase in α2. While there were differences in cell responses to each isoforms, TGF-β3 did not stand out from the other two isoforms. Interestingly, TGF-β2 shared more similarities with TGF-β3 than it did with TGF-β1, in its role in enhancing wound closure and LN332 deposition. These comparative studies have shown that differences exist in the way TGF-β isoforms influence HaCaT cell behaviour, namely migration, laminin deposition and integrin expression.
    • Efficiency measurement. A methodological comparison of parametric and non-parametric approaches.

      Wallace, James; Ward, Damian; Zheng, Wanyu (University of BradfordSchool of Management, 2015-06-24)
      The thesis examines technical efficiency using frontier efficiency estimation techniques from parametric and non-parametric approaches. Five different frontier efficiency estimation techniques are considered which are SFA, DFA, DEA-CCR, DEA-BCC and DEA-RAM. These techniques are then used on an artificially generated panel dataset using a two-input two-output production function framework based on characteristics of German life-insurers. The key contribution of the thesis is firstly, a study that uses simulated panel dataset to estimate frontier efficiency techniques and secondly, a research framework that compares multiple frontier efficiency techniques across parametric and non-parametric approaches in the context of simulated panel data. The findings suggest that, as opposed to previous studies, parametric and non-parametric approaches can both generate comparable technical efficiency scores with simulated data. Moreover, techniques from parametric approaches, i.e. SFA and DFA are consistent with each other whereas the same applies to non-parametric approaches, i.e. DEA models. The research study also discusses some important theoretical and methodological implication of the findings and suggests some ways whereby future research can enable to overcome some of the restrictions associated with current approaches.
    • Efficiency of soil aquifer treatment in the removal of wastewater contaminants and endocrine disruptors. A study on the removal of triclocarban and estrogens and the effect of chemical oxygen demand and hydraulic loading rates on the reduction of organics and nutrients in the unsaturated and saturated zones of the aquifer.

      Tizaoui, Chedly; Mohamed, Mostafa H.A.; Essandoh, Helen M.K. (University of BradfordSchool of Engineering, Design and Technology, 2013-11-22)
      This study was carried out to evaluate the performance of Soil Aquifer Treatment (SAT) under different loading regimes, using wastewater of much higher strength than usually encountered in SAT systems, and also to investigate the removal of the endocrine disruptors triclocarban (TCC), estrone (E1), 17¿-estradiol (E2) and 17¿- ethinylestradiol (EE2). SAT was simulated in the laboratory using a series of soil columns under saturated and unsaturated conditions. Investigation of the removal of Chemical Oxygen Demand (COD), Biochemical Oxygen Demand (BOD), Dissolved Organic Carbon (DOC), nitrogen and phosphate in a 2 meter long saturated soil column under a combination of constant hydraulic loading rates (HLRs) and variable COD concentrations as well as variable HLR under constant COD showed that at fixed HLR, a decrease in the influent concentrations of DOC, BOD, total nitrogen and phosphate improved their removal efficiencies. It was found that COD mass loading applied as low COD wastewater infiltrated over short residence times would provide better effluent quality than the same mass applied as a COD with higher concentration at long residence times. On the other hand relatively high concentrations coupled with long residence time gave better removal efficiency for organic nitrogen. Phosphate removal though poor under all experimental conditions, was better at low HLRs. In 1 meter saturated and unsaturated soil columns, E2 was the most easily removed estrogen, while EE2 was the least removed. Reducing the thickness of the unsaturated zone had a negative impact on removal efficiencies of the estrogens whereas increased DOC improved the removal in the saturated columns. Better removal efficiencies were also obtained at lower HLRs and in the presence of silt and clay. Sorption and biodegradation were found to be responsible for TCC removal in a 300 mm long saturated soil column, the latter mechanism however being unsustainable. TCC removal efficiency was dependent on the applied concentration and decreased over time and increased with column depth. Within the duration of the experimental run, TCC negatively impacted on treatment performance, possibly due to its antibacterial property, as evidenced by a reduction in COD removals in the column. COD in the 2 meter column under saturated conditions was modelled successfully with the advection dispersion equation with coupled Monod kinetics. Empirical models were also developed for the removal of TCC and EE2 under saturated and unsaturated conditions respectively. The empirical models predicted the TCC and EE2 removal profiles well. There is however the need for validation of the models developed
    • Efficient Processing of Corneal Confocal Microscopy Images. Development of a computer system for the pre-processing, feature extraction, classification, enhancement and registration of a sequence of corneal images.

      Ipson, Stanley S.; Qahwaji, Rami S.R.; Ghanchi, Faruque; Elbita, Abdulhakim M. (University of BradfordCentre for Visual Computing, School of Engineering and Informatics, 2014-10-17)
      Corneal diseases are one of the major causes of visual impairment and blindness worldwide. Used for diagnoses, a laser confocal microscope provides a sequence of images, at incremental depths, of the various corneal layers and structures. From these, ophthalmologists can extract clinical information on the state of health of a patient’s cornea. However, many factors impede ophthalmologists in forming diagnoses starting with the large number and variable quality of the individual images (blurring, non-uniform illumination within images, variable illumination between images and noise), and there are also difficulties posed for automatic processing caused by eye movements in both lateral and axial directions during the scanning process. Aiding ophthalmologists working with long sequences of corneal image requires the development of new algorithms which enhance, correctly order and register the corneal images within a sequence. The novel algorithms devised for this purpose and presented in this thesis are divided into four main categories. The first is enhancement to reduce the problems within individual images. The second is automatic image classification to identify which part of the cornea each image belongs to, when they may not be in the correct sequence. The third is automatic reordering of the images to place the images in the right sequence. The fourth is automatic registration of the images with each other. A flexible application called CORNEASYS has been developed and implemented using MATLAB and the C language to provide and run all the algorithms and methods presented in this thesis. CORNEASYS offers users a collection of all the proposed approaches and algorithms in this thesis in one platform package. CORNEASYS also provides a facility to help the research team and Ophthalmologists, who are in discussions to determine future system requirements which meet clinicians’ needs.
    • Electrical and magnetic properties of organic semiconductors: Electrical conductivity and electron spin resonance studies of semiconducting, organic, charge transfer salts.

      Shields, L.; Ahmad, Muhammad M. (University of BradfordPostgraduate School of Studies in Chemistry., 2009-09-24)
      Charge transfer salts of Tetracyanoquinodimethane (TCNQ) were synthesised and their electrical and magnetic properties were investigated. These salts show unusual electrical and magnetic behaviour in contrast to conventional organic compounds. These salts have crystal structures which in general consist of TCNQ radical ions stacked in chains, isolated from each other by the diamagnetic cations. They are thus regarded as "one-dimensional" electrical and magnetic systems. The ESR spectra of these salts are attributed to triplet excitons showing that the spin-spin and electronelectron correlation effects are important. In the ESR spectra (Chapter III) of some TCNQ salts dipolar splitting is observed confirming the spin-spin interaction. These triplet excitons are regarded as bound electron-hole pairs. The experimentally determined dipolar splitting tensors are presented in Chapter III and the intensity data in Chapter IV. A large number of fine structure lines are observed in the ESR spectra of Pyridinium-TCNQ and 4-Aminopyridinium-TCNQ apart from regular triplet exciton lines (Chapter III). These lines are attributed to the trapping of excitons on an extended formula finit (TCNQ2 )n. In Chapter IV the temperature dependent magnetic susceptibilities are discussed in terms of Heisenberg antiferromagnetism and Pauli paramagnetism. In Chapter V temperature dependent behaviour of electrical conductivity is discussed in terms of an exciton band model, the lattice structure of the salts and one-dimensional lattice consisting of defects giving rise to high and low conducting segments. Low temperature electrical and magnetic phases are discussed (Chapters IV and VII) in terms of a band and hopping mechanisms.In Chapter VI self consistent field calculations are made with reference to the tight binding one electron band theory using simplified Roothaan equations considering CNDO approximations. Theoretical results are related to experimental band gaps, spinspin interactions and charge alteration.
    • Electronic Customer Knowledge Management Systems: a multimodal interaction approach : an empirical investigation into the role of the multimodal interaction metaphors to improve usability of Electronic Customer Knowledge Management Systems (ECKMS) and increase the user's trust, knowledge and acceptance.

      Rigas, Dimitrios I.; Alotaibi, Mutlaq B.G. (University of BradfordInformatics Research Institute, 2010-05-14)
      There has been an increasing demand for commercial organisations to foster real-time interaction with customers, because harnessing customer competencies has been shown to be a major contributor towards various benefits, such as growth, innovation and competition. This may drive organisations to embrace the development of multimodal interaction and complement Electronic Customer Knowledge Management Systems (E-CKMS) with metaphors of audio-visual nature. Although the implementation of E-CKMS encounters several challenges, such as lack of trust and information overload, few empirical studies were devoted to assess the role of audio-visual metaphors, and investigate whether these technologies can be put into practice. Therefore, this thesis describes a comparative evaluation study carried out to examine the implication of incorporating multimodal metaphors into E-CKMS interfaces on not only usability of E-CKMS, but also the user¿s trust, knowledge and acceptance. An experimental E-CKMS platform was implemented with three different modes of interaction: Visual-only E-CKMS (VCKMS) with text and graphics, Multimodal E-CKMS (MCKMS) with speech, earcons and auditory icons and Avatar-enhanced multimodal E-CKMS (ACKMS). The three platforms were evaluated by three independent groups of twenty participants each (total=60) who carried out eight common tasks of increasing complexity and design based on three different styles. Another dependent group of forty-eight participants (n=48) was instructed to interact with the systems under similar usability conditions by performing six common tasks of two styles, and fill a questionnaire devised to measure the aspects of user acceptance. The results therein revealed that ACKMS was more usable and acceptable than both MCKMS and VCKMS, whereas MCKMS was more usable than VCKMS, but less acceptable. Inferential Statistics indicated that these results were statistically significant.
    • Electronic Multi-agency Collaboration. A Model for Sharing Children¿s Personal Information Among Organisations.

      Gilligan, Philip A.; Cullen, Andrea J.; Louws, Margie (University of BradfordSchool of Computing, Informatics and Media, 2013-11-21)
      The sharing of personal information among health and social service organisations is a complex issue and problematic process in present-day England. Organisations which provide services to children face enormous challenges on many fronts. Internal ways of working, evolving best practice, data protection applications, government mandates and new government agencies, rapid changes in technology, and increasing costs are but a few of the challenges with which organisations must contend in order to provide services to children while keeping in step with change. This thesis is an exploration into the process of sharing personal information in the context of public sector reforms. Because there is an increasing emphasis of multi-agency collaboration, this thesis examines the information sharing processes both within and among organisations, particularly those providing services to children. From the broad principles which comprise a socio-technical approach of information sharing, distinct critical factors for successful information sharing and best practices are identified. These critical success factors are then used to evaluate the emerging national database, ContactPoint, highlighting particular areas of concern. In addition, data protection and related issues in the information sharing process are addressed. It is argued that one of the main factors which would support effective information sharing is to add a timeline to the life of a dataset containing personal information, after which the shared information would dissolve. Therefore, this thesis introduces Dynamic Multi-Agency Collaboration (DMAC), a theoretical model of effective information sharing using a limited-life dataset. The limited life of the DMAC dataset gives more control to information providers, encouraging effective information sharing within the parameters of the Data Protection Act 1998.
    • An electrophysiological study of chromatic processing in the human visual system. Using visual evoked potentials and electroretinograms to study cortical and retinal contributions to human trichromatic vision.

      McKeefry, Declan J.; Challa, Naveen K. (University of BradfordBradford School of Optometry and Vision Science, 2012-01-24)
      The work in this thesis is concerned with examining the retinal and cortical contributions to human trichromatic colour vision. Chromatic processing at the cortex level was examined using visual evoked potentials (VEPs). These responses were elicited by chromatic spot stimuli, which were manipulated in order to selectively activate the chromatic processing system. Chromatic processing at the retinal level was examined using the electroretinograms (ERGs) for which cone isolating stimuli were used to assess the nature of L and M cone inputs to cone-opponent mechanisms. The results from the VEP experiments suggest VEP morphology is dependent upon 1) chromatic and or luminance contrast content of the stimulus, 2) stimulus size, and 3) extent to which the chromatic stimulus activates either the L/M or S/(L+M) opponent mechanism. The experiments indicate that chromatic stimulation is indexed by large N1 component and small offset responses. Optimal stimulus size for chromatic isolation is 2-4 ° along L/M axes and 6° along S/(L+M) axis. From the ERG experiments, It has been shown that the low (12Hz) and high (30Hz) temporal frequency flickering stimuli can isolate the chromatic and luminance processing mechanisms in the retina. For low temporal frequency ERGs, the L:M ratio was close to unity and L/M phase difference was close to 180°. For high temporal frequency ERGs, the L:M ratio was more than unity and L/M phase difference was close to 90°. In addition to this, the variation in L:M ratio across the retinal eccentricity was also examined. These results suggest, for the chromatic processing, L:M ratio is close to unity independent of retinal eccentricity and individuals. For the luminance processing, L:M ratio is more than unity and depends upon the region of the retina being stimulated. These findings indicate the maintenance of cone selective input for the chromatic processing across the human retina.