39 resultados para in-depth analysis
em Aston University Research Archive
Resumo:
The thesis investigates the properties of two trends or time series which formed a:part of the Co-Citation bibliometric model "X~Ray Crystallography and Protein Determination in 1978, 1980 and 1982". This model was one of several created for the 1983 ABRC Science Policy Study which aimed to test the utility of bibliometric models in a national science policy context. The outcome of the validation part of that study proved to be especially favourable concerning the utility of trend data, which purport to model the development of speciality areas in science over time. This assessment could have important implications for the use of such data in policy formulation. However one possible problem with the Science Policy Study's conclusions was that insufficient time was available in the study for an in-depth analysis of the data. The thesis aims to continue the validation begun in the ABRC study by providing a detailed.examination of the characteristics of the data contained in the Trends numbered 11 and 44 in the model. A novel methodology for the analysis of the properties of the trends with respect to their literature content is presented. This is followed by an assessment based on questionnaire and interview data, of the ability of Trend 44 to realistically model the historical development of the field of mobile genetic elements research over time, with respect to its scientific content and the activities of its community of researchers. The results of these various analyses are then used to evaluate the strenghts and weaknesses of a trend or time series approach to the modelling of the activities of scientifiic fields. A critical evaluation of the origins of the discovered strengths and weaknesses.in the assumptions underlying the techniques used to generate trends from co-citation data is provided. Possible improvements. to the modelling techniques are discussed.
Resumo:
OBJECTIVES: To understand older adults' experiences of moving into extra care housing which offers enrichment activities alongside social and healthcare support. DESIGN: A longitudinal study was conducted which adopted a phenomenological approach to data generation and analysis. METHODS: Semi-structured interviews were conducted in the first 18 months of living in extra care housing. Interpretative phenomenological analysis was used because its commitment to idiography enabled an in-depth analysis of the subjective lived experience of moving into extra care housing. Themes generated inductively were examined against an existential-phenomenological theory of well-being. RESULTS: Learning to live in an extra care community showed negotiating new relationships was not straightforward; maintaining friendships outside the community became more difficult as capacity declined. In springboard for opportunity/confinement, living in extra care provided new opportunities for social engagement and a restored sense of self. Over time horizons began to shrink as incapacities grew. Seeking care illustrated reticence to seek care, due to embarrassment and a sense of duty to one's partner. Becoming aged presented an ontological challenge. Nevertheless, some showed a readiness for death, a sense of homecoming. CONCLUSIONS: An authentic later life was possible but residents required emotional and social support to live through the transition and challenges of becoming aged. Enhancement activities boosted residents' quality of life but the range of activities could be extended to cater better for quieter, smaller scale events within the community; volunteer activity facilitators could be used here. Peer mentoring may help build new relationships and opportunities for interactive stimulation. Acknowledging the importance of feeling-empathic imagination-in caregiving may help staff and residents relate better to each other, thus helping individuals to become ontologically secure and live well to the end.
Resumo:
Purpose. To use anterior segment optical coherence tomography (AS-OCT) to analyze ciliary muscle morphology and changes with accommodation and axial ametropia. Methods. Fifty prepresbyopic volunteers, aged 19 to 34 years were recruited. High-resolution images were acquired of nasal and temporal ciliary muscles in the relaxed state and at stimulus vergence levels of -4 and -8 D. Objective accommodative responses and axial lengths were also recorded. Two-way, mixed-factor analyses of variance (ANOVAs) were used to assess the changes in ciliary muscle parameters with accommodation and determine whether these changes are dependent on the nasal–temporal aspect or axial length, whereas linear regression analysis was used to analyze the relationship between axial length and ciliary muscle length. Results. The ciliary muscle was longer (r = 0.34, P = 0.02), but not significantly thicker (F = 2.84, P = 0.06), in eyes with greater axial length. With accommodation, the ciliary muscle showed a contractile shortening (F = 42.9. P < 0.001), particularly anteriorly (F = 177.2, P < 0.001), and a thickening of the anterior portion (F= 46.2, P < 0.001). The ciliary muscle was thicker (F = 17.8, P < 0.001) and showed a greater contractile response on the temporal side. Conclusions. The accommodative changes observed support an anterior, as well as centripetal, contractile shift of ciliary muscle mass.
Resumo:
Background Adjuvants enhance or modify an immune response that is made to an antigen. An antagonist of the chemokine CCR4 receptor can display adjuvant-like properties by diminishing the ability of CD4+CD25+ regulatory T cells (Tregs) to down-regulate immune responses. Methodology Here, we have used protein modelling to create a plausible chemokine receptor model with the aim of using virtual screening to identify potential small molecule chemokine antagonists. A combination of homology modelling and molecular docking was used to create a model of the CCR4 receptor in order to investigate potential lead compounds that display antagonistic properties. Three-dimensional structure-based virtual screening of the CCR4 receptor identified 116 small molecules that were calculated to have a high affinity for the receptor; these were tested experimentally for CCR4 antagonism. Fifteen of these small molecules were shown to inhibit specifically CCR4-mediated cell migration, including that of CCR4+ Tregs. Significance Our CCR4 antagonists act as adjuvants augmenting human T cell proliferation in an in vitro immune response model and compound SP50 increases T cell and antibody responses in vivo when combined with vaccine antigens of Mycobacterium tuberculosis and Plasmodium yoelii in mice.
Resumo:
Previous studies have suggested separate channels for the detection of first-order luminance (LM) and second-order modulations of the local amplitude (AM) of a texture (Schofield and Georgeson, 1999 Vision Research 39 2697 - 2716; Georgeson and Schofield, 2002 Spatial Vision 16 59). It has also been shown that LM and AM mixtures with different phase relationships are easily separated in identification tasks, and (informally) appear very different with the in-phase compound (LM + AM), producing the most realistic depth percept. We investigated the role of these LM and AM components in depth perception. Stimuli consisted of a noise texture background with thin bars formed as local increments or decrements in luminance and/or noise amplitude. These stimuli appear as embossed surfaces with wide and narrow regions. When luminance and amplitude changes have the same sign and magnitude (LM + AM) the overall modulation is consistent with multiplicative shading, but this is not so when the two modulations have opposite sign (LM - AM). Keeping the AM modulation depth fixed at a suprathreshold level, we determined the amount of luminance contrast required for observers to correctly indicate the width (narrow or wide) of raised regions in the display. Performance (compared to the LM-only case) was facilitated by the presence of AM, but, unexpectedly, performance for LM - AM was even better than for LM + AM. Further tests suggested that this improvement in performance is not due to an increase in the detectability of luminance in the compound stimuli. Thus, contrary to previous findings, these results suggest the possibility of interaction between first-order and second-order mechanisms in depth perception.
Resumo:
The aim of this paper is to provide an overview and an analysis of recent developments and changes in the implementation of sustainability practices by food retailers. It also aims to explore whether the sustainability measurement criteria and indicators identified in the literature can be applied in practice. A literature review identified the current trends, developments and the proposed sustainability objectives, criteria and indicators. Via case study research, we collected empirical data from four retailers. This involved both qualitative and quantitative data drawn from questionnaires and in-depth interviews with logistics directors from four retailers' distribution centres. The empirical data collected from the interviews indicate similarities in some of the characteristics of distribution centres, as well as differences. However, it was difficult to make cross-company comparisons due to the absence of benchmarks or assessments of the relative importance of each sustainability criterion and indicator. This research focused only on two sustainability objectives. Further research on other sustainability objectives is therefore required. Lessons learnt from the four case studies can be taken into consideration when developing future sustainability performance rating scales. The paper provides an in-depth analysis of sustainability in the food chain, with emphasis on food retailing. Its value lies in presenting an attempt to test in practice how a number of sustainability objectives, criteria and indicators are applied in logistics-related processes, identifying the gaps and reporting the potential difficulties.
Resumo:
This study is concerned with the analysis of tear proteins, paying particular attention to the state of the tears (e.g. non-stimulated, reflex, closed), created during sampling, and to assess their interactions with hydrogel contact lenses. The work has involved the use of a variety of biochemical and immunological analytical techniques for the measurement of proteins, (a), in tears, (b), on the contact lens, and (c), in the eluate of extracted lenses. Although a diverse range of tear components may contribute to contact lens spoilation, proteins were of particular interest in this study because of their theoretical potential for producing immunological reactions. Although normal host proteins in their natural state are generally not treated as dangerous or non-self, those which undergo denaturation or suffer a conformational change may provoke an excessive and unnecessary immune response. A novel on-lens cell based assay has been developed and exploited in order to study the role of the ubiquitous cell adhesion glycoprotein, vitronectin, in tears and contact lens wear under various parameters. Vitronectin, whose levels are known to increase in the closed eye environment and shown here to increase during contact lens wear, is an important immunoregulatory protein and may be a prominent marker of inflammatory activity. Immunodiffusion assays were developed and optimised for use in tear analysis, and in a series of subsequent studies used for example in the measurement of albumin, lactoferrin, IgA and IgG. The immunodiffusion assays were then applied in the estimation of the closed eye environment; an environment which has been described as sustaining a state of sub-clinical inflammation. The role and presence of a lesser understood and investigated protein, kininogen, was also estimated, in particular, in relation to contact lens wear. Difficulties arise when attempting to extract proteins from the contact lens in order to examine the individual nature of the proteins involved. These problems were partly alleviated with the use of the on-lens cell assay and a UV spectrophotometry assay, which can analyse the lens surface and bulk respectively, the latter yielding only total protein values. Various lens extraction methods were investigated to remove protein from the lens and the most efficient was employed in the analysis of lens extracts. Counter immunoelectrophoresis, an immunodiffusion assay, was then applied to the analysis of albumin, lactoferrin, IgA and IgG in the resultant eluates.
Resumo:
Biotechnology is one of a series of new `generic technologies' that have been identified by western governments as possessing stategic economic opportunities. In this thesis I examine the characteristics of the technology and the government policies that have been developed to both promote and exploit the underpinning scientific research for biotechnology. The approach I have taken involves an in-depth analysis of the role of university-industry research relations in the development of biotechnology. To this end I carried out a detailed survey of biotechnology companies in the UK on the nature of their interactions and objectives. Through individual case studies of the SERC and DTI club mechanisms in biotechnology, I provide a contemporary appraisal of the development of new mechanisms involving co-ordination and cooperation between industry, government and academia, established to couple state funded science and national economic development. The public policy implications of the club funding systems for science in the UK are examined.
Resumo:
The principal theme of this thesis is the in vivo examination of ocular morphological changes during phakic accommodation, with particular attention paid to the ciliary muscle and crystalline lens. The investigations detailed involved the application of high-resolution imaging techniques to facilitate the acquisition of new data to assist in the clarification of aspects of the accommodative system that were poorly understood. A clinical evaluation of the newly available Grand Seiko Auto Ref/ Keratometer WAM-5500 optometer was undertaken to assess its value in the field of accommodation research. The device was found to be accurate and repeatable compared to subjective refraction, and has the added advantage of allowing dynamic data collection at a frequency of around 5 Hz. All of the subsequent investigations applied the WAM-5500 for determination of refractive error and objective accommodative responses. Anterior segment optical coherence tomography (AS-OCT) based studies examined the morphology and contractile response of youthful and ageing ciliary muscle. Nasal versus temporal asymmetry was identified, with the temporal aspect being both thicker and demonstrating a greater contractile response. The ciliary muscle was longer in terms of both its anterior (r = 0.49, P <0.001) and overall length (r = 0.45, P = 0.02) characteristics, in myopes. The myopic ciliary muscle does not appear to be merely stretched during axial elongation, as no significant relationship between thickness and refractive error was identified. The main contractile responses observed were a thickening of the anterior region and a shortening of the muscle, particularly anteriorly. Similar patterns of response were observed in subjects aged up to 70 years, supporting a lensocentric theory of presbyopia development. Following the discovery of nasal/ temporal asymmetry in ciliary muscle morphology and response, an investigation was conducted to explore whether the regional variations in muscle contractility impacted on lens stability during accommodation. A bespoke programme was developed to analyse AS-OCT images and determine whether lens tilt and decentration varied between the relaxed and accommodated states. No significant accommodative difference in these parameters was identified, implying that any changes in lens stability with accommodation are very slight, as a possible consequence of vitreous support. Novel three-dimensional magnetic resonance imaging (MRI) and analysis techniques were used to investigate changes in lens morphology and ocular conformation during accommodation. An accommodative reduction in lens equatorial diameter provides further evidence to support the Helmholtzian mechanism of accommodation, whilst the observed increase in lens volume challenges the widespread assertion that this structure is incompressible due to its high water content. Wholeeye MRI indicated that the volume of the vitreous chamber remains constant during accommodation. No significant changes in ocular conformation were detected using MRI. The investigations detailed provide further insight into the mechanisms of accommodation and presbyopia, and represent a platform for future work in this field.
Resumo:
Predictive models of peptide-Major Histocompatibility Complex (MHC) binding affinity are important components of modern computational immunovaccinology. Here, we describe the development and deployment of a reliable peptide-binding prediction method for a previously poorly-characterized human MHC class I allele, HLA-Cw*0102.
Resumo:
In the general introduction of the road-accident phenomenon inside and outside Iran, the results of previous research-works and international conferences and seminars on road-safety have been reviewed. Also a sample-road between Tehran and Mashad has been investigated as a case-study. Examining the road-accident data and iriformation,first: the information presented in road-accident report-forms in developed countries is discussed and, second: the procedures for road-accident data collection in Iran are investigated in detail. The data supplied by Iran Road-Police Central Statistics Office, is analysed, different rates are computed, due comparisons with other nations are made, and the results are discussed. Also such analysis and comparisons are presented for different provinces of Iran. It is concluded that each province with its own natural, geographical, social and economical characteristics possesses its own reasons for the quality and quantity of road-accidents and therefore must receive its own appropriate remedial solutions. The question~ of "what is the cost of road-accidents", "why and how evaluate the cost", "what is the appropriate way of approach to such evaluation" are all discussed and then "the cost of road-accidents in Iran" based on two different approaches: "Gross National Output"and "court award" is computed. It is concluded that this cost is about 1.5 per cent of the country's national product. In Appendix 3 an impressive example is given of the trend of costs and benefits that can be attributed to investment in road-safety measures.