Ragnhild Löfgren

Tumour necrosis factor‐α potentiates CR3‐induced respiratory burst by activating p38 MAP kinase in human neutrophils

CR3 and FcγRs are the main receptors involved in the phagocytic process leading to engulfment and killing of microbes by production of reactive oxygen intermediates (ROI) and degranulation. Various inflammatory mediators, such as tumour necrosis factor‐α (TNF‐α) and lipopolysaccharide (LPS), are known to prime neutrophils leading to increased bactericidal responses, but the underlying mechanism of priming has only been partially elucidated. The purpose of this study was to investigate how TNF‐α primes neutrophils for subsequent stimuli via either CR3 or FcγR. The receptors were specifically activated with pansorbins (protein‐A‐positive Staphylococcus aureus) coated with anti‐CR3, anti‐FcγRIIa, or anti‐FcγRIIIb monoclonal antibody. Activation of neutrophils with these particles resulted in ROI production as measured by chemiluminescence. Anti‐CR3 pansorbins induced the most prominent ROI production in neutrophils. TNF‐α potentiated the CR3‐mediated respiratory burst but had little effect on that mediated by FcγRs. The priming effect of TNF‐α on CR3‐mediated ROI production is associated with an increased activation of p38 MAPK as well as tyrosine phosphorylation of p72syk. Pretreatment of neutrophils with the inhibitors for p38 MAPK and p72syk markedly suppressed the respiratory burst induced by CR3. Furthermore, TNF‐α induced about a three‐fold increase in the expression of CR3 in neutrophils, an effect which is blocked by the p38 MAPK inhibitor. Taken together, these results showed that TNF‐α potentiates the CR3‐mediated respiratory burst in neutrophils not only by triggering a p38 MAPK‐dependent up‐regulation of CD11b/CD18 but also by modulating the signalling pathways.

CR3, FcγRIIA and FcγRIIIB induce activation of the respiratory burst in human neutrophils: the role of intracellular Ca2+, phospholipase D and tyrosine phosphorylation

Human neutrophils express two different types of phagocytic receptors, complement receptors (CR) and Fc receptors. In order to characterize the different signaling properties of each receptor we ha ...

Swedish students' experiences of national testing in science: A narrative approach

ABSTRACT In Sweden, the policy of national testing was expanded in 2013 by introducing national tests in science in the sixth grade. The aim of this study is to contribute knowledge about the enactment of this policy of national testing by investigating students’ experiences of taking the tests. Students were interviewed about their experiences of taking national tests, and a narrative analysis was conducted. More specifically, the students’ stories were analysed in terms of identity performances taking shape in relation to a testing discourse. The analysis shows a variety of aspects that the students themselves stress as important when taking the tests; such as the lack of time provided, difficulties regarding the actual tests, processes in the classroom context, and the importance of the test results for their grades. Several of the identity performances in the students’ stories refer to a testing discourse stressing that teachers focus on testing procedures rather than caring for the students when the policy of national testing is enacted. The results also emphasize the difficulties in understanding the test questions as well as discrepancies in science content between what is taught in school and what is being tested.

Gains and Losses: Metaphors in Chemistry Classrooms

This chapter reports on findings from classroom communication in secondary chemistry teaching and learning. The data was analyzed qualitatively regarding the use of metaphors and analogies in relation to atoms and ion formation, with an intention to shed light on students’ scientific understanding as well as on their enculturation into the disciplinary discourse. Theoretically we draw on social semiotics, which allows analyses of language use in its widest sense, comprised of verbal language, images, action, gestures, and more. In our data, we identified common disciplinary metaphors in science, as well as metaphors connected to everyday life. Through the analyses based on systemic functional linguistics (SFL), we also identified anthropomorphic metaphors, with particles, atoms, and ions being humanized with intentions and feelings. Linguistic choices signaling metaphoric language were mainly noted in relation to quite obvious metaphors whereas no such signals or explanations were noted in connection to anthropomorphic metaphors. The study has implications for the design of classroom practices, including the use of discussions to enhance a more reflective use and understanding of the gains and losses around metaphors.

Pupils’ enactments of a policy for equivalence: Stories about different conditions when preparing for national tests

This article revolves around the educational policy introduced in Swedish schools that has extended national testing to younger pupils. The policy is intended to support equal assessment and grading. With the exception of short-term preparations for the tests focused on here, the testing routines are regulated by the state. The paper aims to examine how the policy of national testing in grade six is enacted in different school contexts from a pupil’s point of view, and how this affects equivalence in school. A narrative analysis was conducted of pupils’ (n = 150) stories about preparing for national tests in 11 schools. Three forms of enactments were distinguished according to how responsibility for test preparations was allocated in each school. In some schools, teachers invited the pupils systematically to the translation process. In other schools, pupils were given most of the responsibility for preparation and were left alone as actors vis-a-vis the policy. Finally, in schools that applied ad hoc preparations, the pupils’ position as actors became less secure and more multifaceted. This variety regarding the pupils’ test preparations in school stress that the different enactments of this policy of national testing have implications for the interpretation of equivalence in school.

Grades in the eyes of our parents: a narrative approach to educational resilience in pupils’ stories of getting their first grades

ABSTRACT This paper investigates educational resilience from the pupil’s perspective through an analysis of how Swedish pupils in grade six position themselves in relation to their parents’ expectations and the school’s grading practice. The term ‘resilience’ refers to pupils’ own views of their potential to learn and succeed in school in a social context, where parents are important as normative actors. Data consists of group interviews with pupils at three schools. By using a narrative analysis, a perspective is adopted that considers the multiple meanings involved when pupils position themselves in their stories about grades and parents. The analysis illustrates how a situated understanding of pupils’ senses of resilience makes family expectations, and the importance of pleasing yourself and others and of adapting to grading systems, important aspects to pupils’ own views of their potential to learn and succeed at school. Home and school stand out as different arenas based on the norm of success, but with different ideas about how to deal with schoolwork and grades. A conclusion is that changes in the Swedish grading system might result in a gap regarding knowledge about grades at home and school and double pressure on pupils to achieve good grades.

Engagerande samtal i det naturvetenskapliga klassrummet [Inquiry based dialouge in science classroom]

This study focuses on classroom communication within an inquiry-based science education (IBSE) program, called NTA (Naturvetenskap och Teknik for Alla). The overall aim of the study is to highlight the ways in which productive and engaging conversations are conducted in the classroom. We have analysed the work within the unit ”The Chemistry of food” and the theme testing of fat in food in grade five and six in a Swedish and a Danish science classroom. We have used video cameras and mp3-players to follow the classroom interaction. Our findings indicate that the classroom communication was focused on everyday science content and that the introduction and the summary of the theme were very important for the pupils’ possibilities to productive disciplinary engagement.