3 resultados para foreign material exclusion

em Aston University Research Archive


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The aim of this study was to systematically investigate the factors considered to be responsible for anchorage-dependent cell behaviour to determine which, if any, of these factors exerts greater influence. An efficient means of doing so is the in vitro fibroblast cell culture model. The interaction of fibroblasts with novel substrata gives information about how a biological system reacts to a foreign material. The may ultimately lead to the development of improved biomaterials. This interdisciplinary study combines the elements of surface characterisation and biological testing to determine the nature of the biomaterial/host interface. Polarity and surface charge were found to have an important influence on fibroblast adhesion to hydrogel polymers, by virtue of their water-structuring effects. The same factors were found to affect cell adhesion on undegraded PHB-HV copolymers and their blends with polysaccharides. On degraded PHB-HV copolymers, the degradation process itself played the greatest role in influencing cell response. Increasing surface charge and mechanical instability in these polymers inhibited cell adhesion. Based on the observations of hydrogels and PHB-copolymers a novel material, gel-spun PHB was designed for use as a wound scaffold. In vitro tests using human and mammalian fibroblasts accentuated the importance of polarity and surface charge in determining cellular response. The overall view of cellular behaviour on a broad spectrum of materials highlighted the effects that polarity and surface charge have on water-structuring, and how this affects interfacial conversion. In degradable systems, mechanical stability also plays an inportant role in determining anchorage-dependent cell behaviour.

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T cells are required for an effective adaptive immune response. The principal function of T cells is to promote efficient removal of foreign material by identifying and mounting a specific response to nonself. A decline in T cell function in aging is thought to contribute to reduced response to infection and vaccination and an increase in autoimmunity. This may in part be due to the age-related decrease in naïve CD4+ T cells and increase in antigen-experienced CD4+ T cells, loss of redox homeostasis, and impaired metabolic switching. Switching between subsets is triggered by the integration of extracellular signals sensed through surface receptors and the activation of discrete intracellular metabolic pathways. This article explores how metabolic programming and loss of redox homeostasis during aging may contribute to age-associated changes in T cell phenotype and function. © 2014 Elsevier Inc.

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The past decade has seen a drive to give all pupils the opportunity to study a Modern Foreign Language (MFL) in schools in England, making the teaching and learning of foreign languages part of the primary school curriculum. The Languages for All: Languages for Life (DfES, 2002) policy was introduced through the National Languages Strategy with an objective to increase the nation’s language capability. Raising the educational standard for all pupils is another government initiative with a strong emphasis on inclusion. As the Languages for All policy stresses the importance and benefits of language learning, and inclusion suggests equality and provision for all, this study examines the inclusion of all key stage 2 pupils in foreign language learning and describes perceptions and experiences of pupils, particularly those identified as having special educational needs (SEN) in their performances and negotiations in learning French. As a small scale, qualitative and ethnographically informed, this research is based on participant observation and semi-structured interviews with pupils, teachers of French, teaching assistants and parents. This study draws upon Nussbaum’s capabilities approach and Bourdieu’s concepts as theoretical foundations to analyse the ‘inclusive’ French classroom. As the capabilities approach takes people as ends not means, and goes beyond a focus on resources, it lends itself to critical thinking on issues around inclusion in education. In this context, this researcher investigates the experiences of pupils who struggle with foreign language learning because of their abilities or disabilities, and frames the discussion around the capabilities approach. The study also focuses on motivation and identity in foreign language learning, and draws upon Bourdieu’s concepts of capital, habitus and field to analyse how the participants make sense of and respond to their own circumstances in relation to their performances in the language learning process. This research thus considers Bourdieu’s concepts for a deeper understanding of issues of inequality in learning French and takes up Nussbaum’s insight that pupils may differ in what learning French means to them, and it is not how they differ, but the difference between their capability to choose and achieve what they value that should matter. The findings indicate that although, initially, the French classroom appears ‘inclusive’ due to the provision and practices of inclusion, a closer look shows it to be exclusionary. In addition, responses from the participants on the usefulness and benefits of foreign language learning are contradictory to the objectives of the Languages for All policy, illustrating the complexity of the ‘inclusive’ MFL classroom. This research concludes that structural and interpersonal practices of inclusion contribute to the disguising of exclusion in a classroom deemed ‘inclusive’. Implications are that an understanding and consideration of other aspect of life such as well-being, interests, needs and values should form a necessary part of the language policy.