• The effect of eicosapentaenoic acid on brain and platelet produced bioactive lipid mediators. The effect of eicosapentaenoic acid, docosapentaenoic acid and other polyunsaturated fatty acids on the eicosanoids and endocannabinoids produced by rat brain and human platelets using electrospray ionisation tandem mass spectrometry-based analysis.

      Nicolaou, Anna; Blagden, Nicholas; Mir, Adnan A. (University of BradfordBradford School of Pharmacy, 2010-04-01)
      Eicosapentaenoic acid (EPA) is a polyunsaturated fatty acid (PUFA) with neuroprotective and cardioprotective properties. It is thought that some of the actions of EPA may be attributed to its elongated metabolite, the PUFA docosapentaenoic acid (DPA). Docosahexaenoic acid (DHA) and arachidonic acid (AA) are bioactive PUFA ubiquitously expressed in neural tissues. EPA and AA can be converted by cyclooxygenase (COX) to prostanoids and by lipoxygenase (LOX) to hydroxy fatty acids. PUFA can also be converted to ethanolamides in the brain. These mediators are involved in physiological and pathological processes in many bodily systems. The purpose of this study was to examine the production of eicosanoids, hydroxy fatty acids and fatty acid ethanolamides in young and aged rat brain following EPA or DPA enriched diets. The effects of specific PUFA on human platelet eicosanoid production were also investigated as these mediators play a role in adhesion and aggregation. Liquid chromatography coupled to tandem mass spectrometry (LC/ESI-MS/MS) assays were developed and used to measure lipid mediators in rat brain and human platelets. Ageing in rat brain was accompanied with several changes in the prostanoid and hydroxy fatty acid profiles. Supplementing the diet with EPA or DPA at a daily dose of 200 mg/kg for 8 weeks prevented these changes and decreased levels of PGE2. DPA changed the profile of hydroxy fatty acids synthesised in the brain tissue of young animals. This study has shown that levels of eicosapentaenoylethanolamide (EPA-EA) increase in the brain as a result of ageing and that this is accompanied by an increase in levels of anandamide. Feeding aged animals EPA or DPA further increased the levels of EPA-EA but prevented any change in the level of anandamide. Niacin is used to treat hypercholesterolaemia although it is associated with an unpleasant PGD2 mediated skin flush. This exploratory study has shown that human platelets treated with niacin did not show any changes in their prostanoid and hydroxy fatty acid profiles. Platelets treated with EPA showed increased production of TXB3 and 12-HEPE. Niacin augmented the effects of EPA on human platelet mediator synthesis. Overall, this study has demonstrated that EPA can change brain and platelet lipid mediator synthesis and has provided evidence that could explain some of the neuroprotective and cardioprotective actions of this PUFA.
    • The effect of monolingualism, bilingualism and trilingualism on executive functioning in young and older adults

      Lesk, Valerie E.; Guðmundsdóttir, Margrét Dögg (University of BradfordDivision of Psychology Faculty of Social Sciences, 2015)
      Bilinguals have been posited to have, compared to monolinguals, enhanced cognitive control, consequently exhibiting greater cognitive reserve, which is thought to subsequently delay the onset of clinical expression of dementia. Based on recent evidence suggesting that the more languages one manages the greater cognitive reserve, and that trilinguals undergo greater exercise in language control than bilinguals, this thesis investigated the effects of trilingualism and ageing on cognitive control, in young adults to older adults. As the thesis investigated the novel field of trilingualism and cognitive control, task complexity, the age of second and third language acquisition, language use, and physical and cognitive activity were also, importantly, assessed, as these are possible influencing factors in test performance. The participants completed several cognitive tasks; namely the Simon task, the Inhibition of return task, the Stroop task (inhibition) and the N-back task (working memory). The novel discovery of a trilingual (and bilingual) disadvantage was observed, which could explain some previous inconsistent findings in the bilingualism literature, where trilingualism may influence bilinguals’ test performance, as trilinguals and multilinguals are often mixed in with the bilingual group. Furthermore, the results suggest that second language acquisition and language use does not consistently predict performance in trilinguals (and bilinguals), nor does cognitive activity, although physical activity may modulate language group differences. Importantly, the results from this novel investigation of the effects of trilingualism and ageing on cognitive control suggest that trilingualism (and bilingualism) can, in some cases, be detrimental to cognitive control.
    • Effect of nanoparticles on human cells from healthy individuals and patients with respiratory diseases.

      Anderson, Diana; Thorning, Paul; Osman, Ilham F. (University of BradfordBiomedical Sciences, 2011-04-08)
      Ever increasing applications of nanomaterials (materials with one or more dimension less than 100 nm) has raised awareness of their potential genotoxicity. They have unique physico¿chemical properties and so could have unpredictable effects. Zinc oxide (ZnO) and titanium dioxide (TiO2) are widely used in a number of commercial products. There are published studies indicating that some forms of these compounds may be photo-clastogenic in mammalian cells. What has not been investigated before is the effect of nanoparticles from these compounds in human germ cells. Thus the present study has examined their effects in the presence and absence of UV light in human sperm and compared responses to those obtained with human lymphocytes using the Comet assay to measure DNA damage. The effect of nanoparticles (40-70nm range) was studied in human sperm and lymphocytes in the dark, after pre-irradiation with UV and simultaneous irradiation with UV. The studies do provide some evidence that there are photo-genotoxic events in sperm and lymphocytes in the absence of overt toxicity. The cytotoxic and genotoxic potentials of ZnO and TiO2 as well as their effect on phosphotyrosine expression, were examined in the human epithelial cervical carcinoma cells (Hela cells). This was done to try and determine the underlying molecular events resulting from their exposure to ZnO and TiO2 nanoparticles occurring at the same time as DNA is damaged. Concentration- and time-dependent cytotoxicity, and an increase in DNA and cytogenetic damage with increasing nanoparticle concentrations were reported in this study. Mainly for zinc oxide, genotoxicity was clearly associated with an increase in tyrosine phosphorylation. Nanotechnology has raced ahead of nanotoxicology and little is known of the effects of nanoparticles in human systems, let alone in diseased individuals. Therefore, the effects of TiO2 nanoparticles in peripheral blood lymphocytes from patients with respiratory diseases (lung cancer, chronic obstructive pulmonary disease (COPD) and asthma) were compared with those in healthy individuals using genotoxic endpoints to determine whether there are any differences in sensitivity to nano-chemical insult between the patient and control groups. The results have shown concentration dependent genotoxic effects of TiO2 in both respiratory patient and control groups in the Comet assay and an increasing pattern of cytogenetic damage measured in the micronucleus assay without being statistically significant except when compared with the untreated controls of healthy individuals. Furthermore, modulation of ras p21 expression was investigated. Regardless of TiO2 treatment, only lung cancer and COPD patients expressed measurable ras p21 levels that showed modulation as the result of nanoparticle treatment. Results have suggested that both ZnO and TiO2 nanoparticles can be genotoxic over a range of concentrations without either photoa-ctivation or being cytotoxic.
    • The Effect of oestrogen in a series of models related to schizophrenia and Alzheimer¿s disease. A preclinical investigation into the effect of oestrogen on memory, executive function on and anxiety in response to pharmacological insult and in a model of natural forgetting.

      Neill, Joanna C.; Marshall, Kay M.; Cook, Samantha (University of BradfordSchool of Pharmacy, 2013-03-05)
      Alzheimer¿s disease is associated with aging and is characterised by a progressive cognitive decline. Its onset in women coincides with the abrupt depletion of ovarian steroids prompting the investigation of utilising oestrogen replacement therapy as restoration or a preventative measure. Gonadal steroids have also recently been implicated in other disease states, particularly schizophrenia. In addition to the cognitive decline, sufferers of Alzheimer¿s disease and schizophrenia display anxiety related behaviour which gonadal steroids have also been shown to ameliorate. In this thesis several paradigms were used to investigate the effects of oestradiol benzoate (EB) on cognition and anxiety, utilising the NMDA receptor antagonist PCP, the muscarinic receptor antagonist scopolamine and the dopamine releasing agent amphetamine to induce a cognitive deficit in rats by different pharmacological mechanisms. The thesis also investigated the effects of EB on a delay dependent cognitive deficit model of forgetfulness in natural aging. Results showed that subchronic PCP dosing failed to induce a significant deficit in the novel object recognition task. Locomotor activity tests demonstrated that the PCP treated rats were sensitised to the treatment suggesting that the PCP dosing regimen was successful. There was no significant effect of oestrogen in the reversal learning model or in the plus maze task designed to explore EB¿s effects on anxiety. However, in the latter task there was a trend towards an anxiogenic effect of EB. Results from the delay dependent model of forgetfulness in natural aging demonstrated that EB could enhance recognition memory, but not spatial memory. The results are discussed in the context of the role of gonadal steroids especially oestrogen in combating the cognitive decline seen in schizophrenia, neurodegenerative disease and natural aging.
    • The effect of oxidative stress in lymphocytes from patients with inflammatory bowel disease and various cancer states compared with healthy control individuals.

      Anderson, Diana; Najafzadeh, Mojgan (University of BradfordSchool of Life Sciences, Biomedical Sciences, 2012-01-11)
      In the present investigation peripheral blood lymphocytes from patients with inflammatory bowel disease (IBD) and different cancer states were treated with various agents and compared with lymphocytes from healthy control individuals (HCI) treated in the same way and measured in the Comet assay. For inflammatory bowel disease, patient¿s responses in IBD patients treated with H2O2 were higher than in HCI and crohn¿s patients (CD) were found to have higher responses than Ulcerative colitis (UC) patients. The responses for all IBD and HCI were all reduced in the presence of chaga mushroom extract which behaved in an antioxidant manner. A second group of IBD patients were treated with the heterocyclic amine (food mutagen), IQ and H2O2 and responses were reduced in the presence of the flavonoids, quercetin and epicatechin and compared with HCI similarity treated. In all cells responses were reduced with flavonoids and again CD had higher responses than the UC patients and IBD patients higher than HCI. The responses with CD and UC were that confirmed in two independent studies with IBD, one with chaga mushroom extract and the other with flavonoids. Peripheral lymphocytes from malignant melanoma and suspected melanoma patients and colon cancer and polyposis patients were compared to the lymphocytes from HCI and treated with UVA. There were differential sensitivities when measured in the micronucleus and Comet assays. The cancer patients had higher responses than those in the precancerous states and they in turn were higher than responses in HCI. In all the studies, untreated baseline DNA damage values were also higher in IBD and cancer patients and pre-cancerous patients than HCIs. This would suggest that baseline frequencies of different diseases compared to controls could be an important biomarker in the diagnosis of pre-cancers and early stage cancers. Also peripheral lymphocytes are a useful surrogate for cancers and pre-cancerous disease states since, blood is present in all organs and tissues and DNA is basically the same in all cells.
    • The Effect of PEG-Insulin and Insulin Hexamer Assembly on Stability in Solution and Dry Powders. Hexamer Assembly of PEGylated-Insulin and Insulin Studied by Multi-Angle Light Scattering to Rationally Choose the pH and Zinc Content for Analytical Methods and Formulations of Dry Powders.

      Forbes, Robert T.; Kuo, Mei-Chang; Bueche, Blaine (University of BradfordThe School of Pharmacy, 2013-11-20)
      The objective of this research is to further define the relationship between the charge state of insulin, and the self assembly properties of insulin and PEGylated insulin in solution. Polyethylene glycol (PEG) chains were covalently attached to insulin in order to evaluate their impact on insulin¿s systemic duration of action after pulmonary dosing. This thesis will focus on the assembly properties of the PEG-insulin and insulin, and also demonstrate how the charge state, which was modified by the covalent attachment of PEG, relates to different modes of behavior by anion and cation exchange chromatography. In addition, explain how modifying the assembly state extends to improving formulation properties of spray-dried insulin powders. This thesis is an investigation into the relationship of insulin¿s charge state controlled by pH and how the charge state affects the self assembly of insulin, especially when the zinc ion is removed. Ionic interaction is one of the major forces affecting insulin assembly. The theory that a change in the charge state of insulin could modulate the ionic interaction and reduce hexamer formation at alkaline conditions was investigated. Experiments were designed to measure the level of hexamer with light scattering, and the amount of hexamer was then correlated with the pH and zinc content of the solutions. The importance of the charge state of the monomer and its behavior extends to chromatography and purification modes as well. Specifically, the purification of various species of PEGylated insulin presents a challenge. By varying mobile phase pH which induces the charge to insulin, an ion exchange method demonstrated very high resolution and controllable interaction between the ion exchange media and the insulin derivatives. A highly accurate method for determining molecular weight and thus the average associated state of insulin in solution has been developed using the MALS (Multi-Angle Light Scattering). Insulin concentration, pH, and metal ion concentrations, were in pharmaceutically relevant ranges. The MALS method was developed to evaluate how the parameters above affect the self-assembly properties of insulin, and use the assembly properties to improve formulations of insulin or PEGylated insulin. To use the light scattering technique the dn/dc (change in refractive index with change in concentration) is required. During the method development, the dn/dc of insulin was measured at 690 nm, and a value of 0.185 mL/g based on theory was confirmed. A novel approach for preparing insulin powders with improved chemical stability, based on maintaining the dissociation of hexamers in solution during the spray drying process was developed. The mode presented here is to remove the zinc ions from solution, increase the pH from 6.6 to 7.8, and maintain a low concentration of insulin approximately 2 to 15 mg/mL. Each of these factors alone decreases the hexamer population in solution, but by combining all three factors, hexamers are driven to very low levels of equilibrium. The increased stability of the powders is predominately related to the decrease in covalent insulin dimer (CID). The data presented correlates a reduced hexamer population in the solution with lower levels of CID¿s in the dry powder compared to controls. The CID formation rate was reduced by 40% compared to a control.
    • Effect of post-harvest treatment on ripening and quality of tomato fruit using ozone. Application of different ozone doses as controlled atmosphere storage for delay ripening and maintaining the quality of tomatoes and effect of ozone on antioxidant and sugar compounds at different stages of tomato fruit ripening.

      Karodia, Nazira; Tizaoui, Chedly; Shalluf, Milad A. (University of BradfordSchool of Engineering, Design and Technology, 2010-10-15)
      Tomatoes are widely produced and consumed due to their nutritional content and versatility. However, the tomato is a soft fruit liable to damage and flavour deterioration. Hence, the main challenge for the tomato producing industry is to prevent the high loss incurred during harvest, handling and transportation of the crops. The objective of this study was to investigate the overall nutritional implication of controlled storage of tomatoes using ozone on the ripening process and the basic nutritional components of tomatoes. This investigation was also designed to focus on the effect of different ozone doses on the basic components and properties (carotenoids, ascorbic acid, total antioxidant activity and soluble sugars content) of the quality and dynamic maturity of tomatoes. Green tomatoes (Rio Grande) were treated in glass chambers with ozone enriched air [(air + 2, 7 and 21 mg O3/g tomato) and control (air only)] under humidity and temperature of 90-95% and 14-17 oC respectively. Tomatoes were sampled after 14 days of ozone treatment in the storage chamber and analyzed for different quality parameters (appearance, weight loss, Total Soluble Solids (TSS), titratable acidity, total ascorbic acid and carotene) of the ripening. The variety Elegance tomatoes were selected and the fruits were graded by colour and subjected to treatment with ozone (in doses 0 (clean air), 0.25, 0.50, and1.00 mg O3/g tomatoes) during storage for 6 days under the same humidity and temperature conditions. The fruits were analysed for carotenoids, ascorbic acid content, total antioxidant activity and soluble sugars.Analysis of the fruits clearly showed that ozone significantly delayed the development of colour on the surface, particularly in the low doses, and caused black spots on the surface of the tomatoes, particularly in higher ozone doses. Ozone did not affect the ascorbic acid and titratable acidity content. However ozone did reduce the Total Soluble Solids (TSS) by about 10% at the lowest ozone dose. A high inhibition of accumulation of carotenoids, particularly at low dose, of the tomatoes (Rio Grande) was also observed. Tomatoes (Elegance) under ozone treatments contained higher ß-carotene than those under the control treatment and lycopene content increased during storage in the red stage of tomato fruits. Ascorbic acid (AsA), dehydroascorbic acid (DHA) and the total of AsA and DHA concentrations, and ratios of redox (ASA/ (ASA + DHA) and DHA/AsA in pericarp and pulp of tomatoes tissue, did not show clear differences between the different treatments. The concentrations of the glucose and fructose increased in the tomatoes which were subjected to ozone treatments. Results from this study show that controlled atmosphere storage of tomatoes using ozone is a viable technique which warrants further study.
    • The effect of prostaglandins in myometrial tissue; a functional and lipidomic study. The influence of the hormonal milieu on the functional response to prostaglandins and ex vivo lipid biosynthesis in myometrial tissues.

      Marshall, Kay M.; Sabar, Uzmah Jabeen (University of BradfordBradford School of Pharmacy, 2013-11-21)
      Prostaglandins are integral mediators in reproductive processes but their exact role in uterine function is still not clear. In addition, ethical restraints have limited the availability of human tissue to investigate uterine prostanoid receptor populations. The aim of this thesis was to characterise the prostanoid receptors on the human and rat myometrium in order to evaluate the potential of the rat as an animal model of human uterine function and disease. For functional analysis of myometrial prostanoid receptors the immersion technique was utilised. LC-ESI-MS/MS was also used to measure the ex vivo myometrial release of prostanoid metabolites. The results show that both the rat and human uterus displays cyclical changes in uterine motility, with myogenicity greatest in the follicular and oestrus stages. The data also indicate that whilst the human uterus is responsive to EP3, EP2, TP, FP and IP receptor agonists, a functional population of only EP3, EP2 and FP receptors is present on the rat uterus, although the TP receptor appears to be upregulated at gestation and post-partum. The results also show that myometrial prostanoid release in the human uterus is cyclically regulated, with the greatest amount of prostaglandins being released during the late follicular stage. In conclusion, although similarities do exist with regard to the ovarian regulation of uterine motility in both the rat and human uterus, the differences in the apparent functional prostaglandin receptor populations between the two species suggest further work is required before the rat can be used as a model of human uterine function.
    • 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.