Analysing pedagogical change: Physics teachers' responses to a new curriculum.

This paper describes teachers' attempts to implement the 1994 New Zealand physics curriculum in the first year of its introduction to secondary schools in 1998. Analysis of interviews with 10 physics teachers and the three curriculum writers led to the identification of a number of barriers to changes in pedagogical practices. The barriers identified aligned with factors that had been identified by other researchers as important influences on teachers undergoing change. It is argued that a sociocultural perspective suggests that there were three main reasons why significant pedagogical change was not occasioned by the curriculum document. Firstly, there was very limited knowledge about why changes were being implemented. Secondly, there was little social and system support for the curriculum change. Finally, teachers had no time to focus on and reflect on the change

Role of IL-10 in the Immune Response to Staphylococcus aureus Nasal Carriage

Staphylococcus aureus is a human pathogen with the potential to cause life-threatening diseases, but it can also be found as a commensal in up to 50% of the population. Its main reservoir is located in the nostrils, where macrophages are the principal mucosal APC and elicit a predominantly IL-10 response. Induction of IL-10 requires phosohoinositide 3-kinase activity, upon stimulation with S. aureus ligands through toll-like receptor 2 binding. It is hypothesized that IL-10 production by macrophages in the nasal mucosa allows S. aureus to persist in this niche as a commensal. To test this hypothesis, a cohort of S. aureus nasal carriers and non-carriers was developed and cytokine responses were compared between these groups. The data suggest that carriers may be producing more IL-10 than non-carriers, while TNF-α production remained unchanged, in response to heat-killed S. aureus. This differential IL-10 production could be a key factor behind S. aureus commensalism

From the drawing board into schools: An analysis of the development and implementation of a new physics curriculum in New Zealand secondary schools

This thesis explored the introduction of a new physics curriculum in New Zealand secondary schools. It was part of a nationwide overhaul of the whole school curriculum from primary to secondary schools, initiated in the early 1990s. The study of curriculum change is inextricably woven with teacher change, as the teacher is seen as central to any real change in curricula in the classroom. Some theories of teacher change are reviewed here and synthesised into a list of criteria relevant to bringing about effective change in teachers and their practices. A sociocultural perspective emerged as being a useful theoretical approach in analysing and explaining these processes of curriculum change and teacher change because it takes a holistic approach that deals with 'people, places and things' and the discourses involved therein. In particular, Wenger's sociocultural theory was used to study the introduction of a new senior physics curriculum. His terms 'reification' and 'participation' were seen to apply to this research: the curriculum document was taken to be a reified communication artifact, and 'participation' is involved in every stage of its development and implementation. In the context of this theorising, data was procured from in-depth interviews with the three curriculum writers and ten physics teachers in and around a provincial city in New Zealand. The teachers were interviewed three times over a period of three years: before, during and after the first year of implementation; namely 1996 to 1998. The interviews showed that most of these ten physics teachers did not undergo any significant change in their teaching because of the introduction of 'Physics in the New Zealand Curriculum'. The reasons or barriers identified, such as lack of guidelines and clarity, and contentment with their own existing practice, were aligned with factors that have been identified by other researchers as important influences on teachers undergoing change, such as clarity of change and need for change. Three key elements were identified from these issues emerging from the data as necessary conditions or resources for teacher change: knowledge, support and time. In the present study, there was very limited knowledge held by the teachers about 'what', 'how' and 'why' changes were being implemented. Secondly, there was little social and system support for the curriculum change. Finally, teachers had little time to focus on and reflect on the change. A model of curriculum change, incorporating Wenger's notions of 'reification' and 'participation', but extended to include 'dereification' emerged from the data. 'Dereification' highlighted an important stage whereby the curriculum document as an artifact, needed to be incorporated into the plane of lived experiences of teachers. The introduction of the term 'dereification' supported the development of this model of curriculum change incorporating teacher change whereby the model outlined processes of reification and dereification involved in a mandated curriculum change. The model of curriculum change developed here also contained a screen that symbolises the lack of intersubjective linkage between teachers and the designers of the new curriculum. There was no follow-up teachers' guide, not enough explanation of the curriculum document, no direct communication between the writers and the teachers, and insufficient professional development for the teachers using it. The research findings led to three propositions: the curriculum document as a key artifact was not sufficient to effect a curriculum change; the lack of transparency of the curriculum document development was a constraint on teachers' commitment to the curriculum change; and the lack of support for teachers in their dereification of the curriculum document impacted negatively on curriculum change. The key elements of knowledge, support and time identified as crucial for teachers to effect any real change in their practice are critical at different points in the model of curriculum change. It is suggested that using such an interplay between the factors underlying teacher change and the sociocultural analysis of curriculum change, might enable more pro-active intervention at the various stages of the process of a curriculum change to effect a real change

Spherical nematics with a threefold valence

We present a theoretical study of the energetics of thin nematic shells with two charge one-half defects and one charge-one defect. We determine the optimal arrangement: the defects are located on a great circle at the vertices of an isosceles triangle with angles of 66 degrees at the charge one-half defects and a distinct angle of 48 degrees, consistent with experimental findings. We also analyse thermal fluctuations around this ground state and estimate the energy as a function of thickness. We find that the energy of the three-defect shell is close to the energy of other known configurations having two charge-one and four charge one-half defects. This finding, together with the large energy barriers separating one configuration from the others, explains their observation in experiments as well as their long-time stability.Comment: 8 pages, 7 figure

Mesenchymal Stem Cells: Biological Characteristics and Potential Clinical Applications for Haematopoietic Stem Cell Transplantation

Mesenchymal stem cells (MSCs) are multipotent cells that can be expanded and manipulated ex vivo. These cells demonstrated three biological characteristics that qualify them for the use in cellular therapy: (1) potential of differentiation, (2) secretion of trophic factors and (3) immunoregulatory properties. The bone marrow (BM) has been considered as the traditional source of MSCs and much knowledge for potential clinical applications has been obtained from studies using MSCs derived from adult bone marrow. MSCs need to be expanded in vitro for the purpose of cell therapy. However, sometimes, the culture expansion could generate cytogenetic and molecular alterations. Accumulation of these alterations during many passages of culture could lead to malignant cell transformation. So, it is important to perform a rigorous control using different methods to test the safety and efficacy of MSCs for cell therapies. BM-MSCs have potential clinical applications in haematopoietic stem cell transplantation (HSCT) as an adjuvant cellular therapy. This chapter reviews the advances in the study of MSCs and the potential clinical applications of MSCs in haematopoietic stem cell transplantation (HSCT). We also describe the importance of statistical methods to aid the analysis of the efficacy and safety for the clinical use of MSCs for HSCT

La diplomacia pública americana: lecciones para una comunicación internacional

Las estrategias que proponen los EEUU para la reactivación de la diplomacia pública son seguidas con atención por el resto de los actores internacionales y determinan sus relaciones y la forma de presentarse ante una audiencia global. En cierta medida, configuran las prácticas de la comunicación política internacional. El caso de la “guerra de las ideas”, desarrollada de forma paralela a la “guerra contra el terror” posterior al 11/S, resulta de particular interés. El artículo describe las diversas estrategias que incluyen la campaña y propone vías de evaluación de su eficacia

Index de la chronique de jurisprudence. Liste des titres

A utilização de plantas para fitorremediação do solo requer que a concentração do poluente esteja dentro dos limites de tolerância da planta para que o tratamento seja eficaz. O rebrotamento e crescimento da herbácea aquática Echinochloa polystachya em solo de várzea contaminado por petróleo de Urucu foram estudados por meio do plantio de propágulos em frascos com 2 L de solo contaminado pela mistura de 7 dosagens de petróleo, distribuídas entre 0 e 0,46 L m-2. O experimento foi realizado em Casa de Vegetação e as plantas foram monitoradas durante 70 dias. Em resposta ao aumento da dosagem do petróleo, houve diminuição da biomassa aérea, da proporção de biomassa aérea viva/aérea total, do comprimento da folha e do número de folhas. A interação entre dosagem e tempo de exposição levou à diminuição do número de folhas, comprimento da folha, altura de inserção da primeira folha e aumento do número de folhas com comprometimento fitossanitário. A utilização de E. polystachya para fitorremediação pode estar limitada a solos com baixas dosagens de petróleo de Urucu.The use of plants for the phytoremediation of contaminated soils requires that the concentrations of the pollutant lay within the limits of tolerance of the plant in order to ensure the efficacy of the treatment. The vegetative propagation and growth of the aquatic herbaceous plant Echinochloa polystachya were studied by planting parts of stems in 2 L of várzea soils previously contaminated by crude oil from Urucu, in 7 different dosages of oil ranging from 0 to 0.46 L m-2. The experiment took place in a green house and the plants were monitored during a 70 days period. Increasing the oil concentration lead to the decrease of the above-ground biomass, the ratio alive aerial biomass/total aerial biomass, leaf length and number of leaves. The interaction between dosage and time of exposition contributed for a reduction in the number and length of leaves, height of insertion of the first leaf, and increase of the number of unhealthy leaves. The use of E. polystachya for phytoremediation may be limited to soils with lower concentrations of crude oil from Urucu

Les externalitats de l'agricultura periurbana : el cas de l'Horta de Lleida

L'agricultura periurbana, a través de la funció econòmica, social i mediambiental que porta a terme, desenvolupa un nombre elevat d'externalitats positives i negatives. Atès que es tracta de falles del mercat, l'estudi s'ha centrat en l'àmbit de l'Horta de Lleida, on, a través de l'avaluació participativa d'un grup d'experts, s'han detectat trenta-una externalitats generades per aquest espai agrari periurbà. La funció mediambiental és la que genera el benefici social més gran entre la població de l'entorn, sense que aquest benefici suposi un retorn al titular de l'explotació agrària. D'altra banda, una de cada cinc externalitats de l'Horta lleidatana és negativa i genera costos socials que no internalitza el mercat.Through its economic, social and environmental functions, peri-urban agriculture results in a large number of positive and negative externalities. As these are market failures, this study focuses on the suburban agricultural area of Horta de Lleida where thirty-one externalities have been identified by means of a participatory assessment process with a group of experts. The environmental function produces the greatest social benefit to the surrounding population, although there is no benefit for landowners. Moreover, one in five externalities of Horta de Lleida is negative and results in social costs that are not internalised in the market.La agricultura periurbana, a través de la función económica, social y medioambiental que lleva a cabo, desarrolla un número elevado de externalidades positivas y negativas. Dado que se trata de fallos del mercado, el estudio se ha centrado en el ámbito de la Horta de Lleida, donde, a través de la evaluación participativa de un grupo de expertos, se han detectado treinta y una externalidades generadas por este espacio agrario periurbano. La función medioambiental es la que genera el mayor beneficio social entre la población del entorno, sin que este beneficio suponga un retorno al titular de la explotación agraria. Por otra parte, una de cada cinco externalidades de la Horta leridana es negativa y genera costes sociales que no internaliza el mercado.L'étude de recherche montre que l'agriculture périurbaine, grâce à ses fonctions économique, sociale et environnementale, développe un nombre élevé d'externalités positives et négatives. Compte tenu du fait qu'il s'agit de défaillances du marché, l'étude est principalement axée autour de la région de l'Horta de Lleida où, à partir de l'évaluation participative d'un groupe d'experts, ont été identifiées trente et une externalités générées par cet espace agraire périurbain. La fonction environnementale est celle qui génère le plus grand bénéfice social pour la population des alentours, sans que cet avantage implique un gain économique pour le propriétaire de l'exploitation agricole. En outre, une externalité sur cinq dans l'Horta de Lleida est négative et génère des coûts sociaux qui ne sont pas internalisés par le marché