26 resultados para Class analysis

em Aston University Research Archive


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This thesis examines the teachers' and the pupils' relations in the schooling of black boys. The study using the methodology of participant observation focusses on one school (Kilby) in an area of black population in an English city. The thesis’s intentions are two fold: firstly, in order to examine these relations, two major aspects of their interaction are addressed, that of the absence of teachers from conventional 'race-relations' research, and, the identification and examination of the anti-school pupils' sub-cultures. Two substantive questions are asked: what is the response of the teachers to the schooling of black pupils? and, what is the meaning of the pupils' resistance to schooling? Secondly, in attempting to answer these questions and offer a critique of the dominant 'race-relations' culturalist explanation of black youth's response to schooling, a theoretical framework has been developed which takes account of both the 'economic' and the 'sociological' perspectives. Methodology allowed and pointed to the importance of examining the teachers' ideologies and practices as well as those of the black boys. It is argued that a class analysis of the racially structured British society is more adequate than the conventional ethnic approach in explaining the black boys' location within Kilby School. Hence, it is posited that the major problem in the schooling of black youth is not that of their culture but of racism, which pervasively structures the social reality at Kilby school. Racism is mediated both through the existing institutional framework that discriminates against working-class youth and through the operation of race specific mechanisms, such as the process of racist stereotyping. It is thus further argued that the Kilby school teachers are of central causal significance to the - problems that the boys encounter. Furthermore, it is in response to these racist ideologies and practices that both West Indian and Asian pupils develop specific forms of collective resistance, which are seen to be linked to the wider black community, as legitimate strategies of survival.

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Antigenic peptide is presented to a T-cell receptor (TCR) through the formation of a stable complex with a major histocompatibility complex (MHC) molecule. Various predictive algorithms have been developed to estimate a peptide's capacity to form a stable complex with a given MHC class II allele, a technique integral to the strategy of vaccine design. These have previously incorporated such computational techniques as quantitative matrices and neural networks. A novel predictive technique is described, which uses molecular modeling of predetermined crystal structures to estimate the stability of an MHC class II-peptide complex. The structures are remodeled, energy minimized, and annealed before the energetic interaction is calculated.

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The accurate in silico identification of T-cell epitopes is a critical step in the development of peptide-based vaccines, reagents, and diagnostics. It has a direct impact on the success of subsequent experimental work. Epitopes arise as a consequence of complex proteolytic processing within the cell. Prior to being recognized by T cells, an epitope is presented on the cell surface as a complex with a major histocompatibility complex (MHC) protein. A prerequisite therefore for T-cell recognition is that an epitope is also a good MHC binder. Thus, T-cell epitope prediction overlaps strongly with the prediction of MHC binding. In the present study, we compare discriminant analysis and multiple linear regression as algorithmic engines for the definition of quantitative matrices for binding affinity prediction. We apply these methods to peptides which bind the well-studied human MHC allele HLA-A*0201. A matrix which results from combining results of the two methods proved powerfully predictive under cross-validation. The new matrix was also tested on an external set of 160 binders to HLA-A*0201; it was able to recognize 135 (84%) of them.

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A set of 38 epitopes and 183 non-epitopes, which bind to alleles of the HLA-A3 supertype, was subjected to a combination of comparative molecular similarity indices analysis (CoMSIA) and soft independent modeling of class analogy (SIMCA). During the process of T cell recognition, T cell receptors (TCR) interact with the central section of the bound nonamer peptide; thus only positions 4−8 were considered in the study. The derived model distinguished 82% of the epitopes and 73% of the non-epitopes after cross-validation in five groups. The overall preference from the model is for polar amino acids with high electron density and the ability to form hydrogen bonds. These so-called “aggressive” amino acids are flanked by small-sized residues, which enable such residues to protrude from the binding cleft and take an active role in TCR-mediated T cell recognition. Combinations of “aggressive” and “passive” amino acids in the middle part of epitopes constitute a putative TCR binding motif

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T cell receptor (TCR) recognition of peptide-MHC class I (pMHC) complexes is a crucial event in the adaptive immune response to pathogens. Peptide epitopes often display a strong dominance hierarchy, resulting in focusing of the response on a limited number of the most dominant epitopes. Such T cell responses may be additionally restricted by particular MHC alleles in preference to others. We have studied this poorly understood phenomenon using Theileria parva, a protozoan parasite that causes an often fatal lymphoproliferative disease in cattle. Despite its antigenic complexity, CD8+ T cell responses induced by infection with the parasite show profound immunodominance, as exemplified by the Tp1(214-224) epitope presented by the common and functionally important MHC class I allele N*01301. We present a high-resolution crystal structure of this pMHC complex, demonstrating that the peptide is presented in a distinctive raised conformation. Functional studies using CD8+ T cell clones show that this impacts significantly on TCR recognition. The unconventional structure is generated by a hydrophobic ridge within the MHC peptide binding groove, found in a set of cattle MHC alleles. Extremely rare in all other species, this feature is seen in a small group of mouse MHC class I molecules. The data generated in this analysis contribute to our understanding of the structural basis for T cell-dependent immune responses, providing insight into what determines a highly immunogenic p-MHC complex, and hence can be of value in prediction of antigenic epitopes and vaccine design.

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The security and reliability of a class of public-key cryptosystems against attacks by unauthorized parties, who had acquired partial knowledge of one or more of the private key components and/or of the message, were discussed. The standard statistical mechanical methods of dealing with diluted spin systems with replica symmetric considerations were analyzed. The dynamical transition which defined decryption success in practical situation was studied. The phase diagrams which showed the dynamical threshold as a function of the partial acquired knowledge of the private key were also presented.

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Comparative research on inter-municipal cooperation in eight European countries shows that there is a great variety of institutional arrangements for cooperation across the different countries. Also, these arrangements tend to change over time in terms of the scope of cooperation among partners, their composition and the degree of organizational integration. This article describes and analyzes the variety of and shifts in institutional arrangements for a specific class of inter-municipal cooperation arrangements: those that are set up to provide for the joint delivery of public services. It is argued that specific arrangements are typically the outcomes of interaction between national institutional contexts,?environmental factors and local preferences.

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1. Pearson's correlation coefficient only tests whether the data fit a linear model. With large numbers of observations, quite small values of r become significant and the X variable may only account for a minute proportion of the variance in Y. Hence, the value of r squared should always be calculated and included in a discussion of the significance of r. 2. The use of r assumes that a bivariate normal distribution is present and this assumption should be examined prior to the study. If Pearson's r is not appropriate, then a non-parametric correlation coefficient such as Spearman's rs may be used. 3. A significant correlation should not be interpreted as indicating causation especially in observational studies in which there is a high probability that the two variables are correlated because of their mutual correlations with other variables. 4. In studies of measurement error, there are problems in using r as a test of reliability and the ‘intra-class correlation coefficient’ should be used as an alternative. A correlation test provides only limited information as to the relationship between two variables. Fitting a regression line to the data using the method known as ‘least square’ provides much more information and the methods of regression and their application in optometry will be discussed in the next article.

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A novel biosensing system based on a micromachined rectangular silicon membrane is proposed and investigated in this paper. A distributive sensing scheme is designed to monitor the dynamics of the sensing structure. An artificial neural network is used to process the measured data and to identify cell presence and density. Without specifying any particular bio-application, the investigation is mainly concentrated on the performance testing of this kind of biosensor as a general biosensing platform. The biosensing experiments on the microfabricated membranes involve seeding different cell densities onto the sensing surface of membrane, and measuring the corresponding dynamics information of each tested silicon membrane in the form of a series of frequency response functions (FRFs). All of those experiments are carried out in cell culture medium to simulate a practical working environment. The EA.hy 926 endothelial cell lines are chosen in this paper for the bio-experiments. The EA.hy 926 endothelial cell lines represent a particular class of biological particles that have irregular shapes, non-uniform density and uncertain growth behaviour, which are difficult to monitor using the traditional biosensors. The final predicted results reveal that the methodology of a neural-network based algorithm to perform the feature identification of cells from distributive sensory measurement has great potential in biosensing applications.

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This thesis examines the British Bus and Tram Industry from 1889 to 1988. The first determinant of the pattern of industrial relations is the development of the labour-process. The labour process changes with the introduction of new technology (electrified trams and mechanised buses), the concentration and centralisation of ownership, the decline of competition, changing market position, municipal and state regulation, ownership and control. The tram industry, as a consequence of electrification, is almost wholly municipally owned and the history of the labour process from horse-trams to the decline of the industry is examined. The bus industry has a less unified structure and is examined by sector; London, Municipal, and Territorial/Provincial. The small independent sector is largely ignored. The labour process is examined from the horse-bus to the present day. The development of resistance in the labour process is discussed both as a theoretical problematic (the `Braverman Debate') and through the process of unionisation, the centralisation and bureaucratisation of the unions, the development of national bargaining structures (National Joint Industrial Council and the National Council for the Omnibus Industry), and the development of resistance to those processes. This resistance takes either a syndicalist form, or under Communist Party leadership the form of rank and file movements, or simply unofficial organisations of branch officials. The process of centralisation of the unions, bureaucratisation and the institutionalisation of bargaining and the relationship between this process and the role of the Unions in the Labour Party is examined. Neo-corporatism, that is the increasing integration of the leadership of the main Union, the T.G.W.U.with the Labour Party and with the State is discussed. In theoretical terms, this thesis considers the debate around the notion of `labour process', the relationship between labour process and labour politics and between labour process and labour history. These relationships are placed within a discussion of class consciousness.

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The thesis provides an analysis of an occupation in the process of making itself a profession. The solicitors' profession in Birmingham underwent a great many changes during the 19th century against a background of industrialisation and urbanisation. The solicitors' conception of their status and role, in the face of these challenges, had implications for successful strategies of professionalisation. The increased prestige and power of the profession, and especially its elite, are examined in their social context rather than in terms of a technical process, or educational and organisational change. The thesis argues that -the profession's social relationships and broad concerns were significant in establishing solicitors as "professional men". In particular these are related to the profession's efforts to gain control of markets for legal services and increase social status. In the course of achieving these aims a concept of profession and a self-image were articulated by solicitors in order to persuade society and the state of the legitimacy of their claims. The concept of the gentlemanly professional was of critical importance in this instance. The successful creation of a provincial professional "community" by the end of the 19th century rested principally on a social and moral conception of professionalism rather than one which stressed specialised training and knowledge, professional organisations and credentials.

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The state of the art in productivity measurement and analysis shows a gap between simple methods having little relevance in practice and sophisticated mathematical theory which is unwieldy for strategic and tactical planning purposes, -particularly at company level. An extension is made in this thesis to the method of productivity measurement and analysis based on the concept of added value, appropriate to those companies in which the materials, bought-in parts and services change substantially and a number of plants and inter-related units are involved in providing components for final assembly. Reviews and comparisons of productivity measurement dealing with alternative indices and their problems have been made and appropriate solutions put forward to productivity analysis in general and the added value method in particular. Based on this concept and method, three kinds of computerised models two of them deterministic, called sensitivity analysis and deterministic appraisal, and the third one, stochastic, called risk simulation, have been developed to cope with the planning of productivity and productivity growth with reference to the changes in their component variables, ranging from a single value 'to• a class interval of values of a productivity distribution. The models are designed to be flexible and can be adjusted according to the available computer capacity expected accuracy and 'presentation of the output. The stochastic model is based on the assumption of statistical independence between individual variables and the existence of normality in their probability distributions. The component variables have been forecasted using polynomials of degree four. This model is tested by comparisons of its behaviour with that of mathematical model using real historical data from British Leyland, and the results were satisfactory within acceptable levels of accuracy. Modifications to the model and its statistical treatment have been made as required. The results of applying these measurements and planning models to the British motor vehicle manufacturing companies are presented and discussed.

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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.

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Objective: To determine the efficacy of cholinesterase inhibitors (ChEIs) in improving the behavioral and psychological symptoms of dementia (BPSD) in patients with Alzheimer’s disease (AD). Data sources: We searched MEDLINE, Cochrane Registry, and the Cumulative Index to Nursing and Allied Health Literature (CINAHL) from 1966 to 2007. We limited our search to English Language, full text, published articles and human studies. Data extraction: We included randomized, double-blind, placebo-controlled trials evaluating the efficacy of donepezil, rivastigmine, or galantamine in managing BPSD displayed by AD patients. Using the United States Preventive Services Task Force (USPSTF) guidelines, we critically appraised all studies and included only those with an attrition rate of less than 40%, concealed measurement of the outcomes, and intention to treat analysis of the collected data. All data were imputed into pre-defined evidence based tables and were pooled using the Review Manager 4.2.1 software for data synthesis. Results: We found 12 studies that met our inclusion criteria but only nine of them provided sufficient data for the meta-analysis. Among patients with mild to severe AD and in comparison to placebo, ChEIs as a class had a beneficial effects on reducing BPSD with a standard mean difference (SMD) of -0.10 (95% confidence interval [CI]; -0.18, -0.01) and a weighted mean difference (WMD) of -1.38 neuropsychiatry inventory point (95% CI; -2.30, -0.46). In studies with mild AD patients, the WMD was -1.92 (95% CI; -3.18, -0.66); and in studies with severe AD patients, the WMD was -0.06 (95% CI; -2.12, +0.57). Conclusion: Cholinesterase inhibitors lead to a statistical significant reduction in BPSD among patients with AD, yet the clinical relevance of this effect remains unclear.