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- Berggren, Johannes
(författare)
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An important part of the whole : The role of metaphors in the teaching and learning of mathematics
- 2022
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Licentiatavhandling (övrigt vetenskapligt/konstnärligt)abstract
- This study aims to investigate the role of metaphor in the teaching and learning of mathematics. Two different studies help to fulfil this aim.The first study involves a configurative literature review of empirical mathematics education research where two interpretations of the metaphor concept are applied: conceptual metaphor and extraneous metaphor, with the purpose of distinguishing patterns in metaphor concept use. The analysis found explicit, vague, or absent theoretical definitions of the metaphor concept as well as several metaphor examples, and generated three categories of concept use: 1) Conceptual metaphor, 2) Extraneous metaphor, and 3) Potentially conceptual/extraneous. The review stresses the need for a theoretical and empirical distinction between different types of metaphors, to sharpen the analytical tools available to researchers and, by extension, to more clearly highlight the specific function of metaphor in teachers’ classroom work.The second study examines the presence of three conceptual metaphors as the basis for rational numbers as fractions in Swedish textbooks for years 1–3 and which aspects of fractions are distinguished in the student responses required in these books. The results are related to process-object theory (Sfard, 1991), intending to discern the different degrees of reification of the mathematical objects that hypothetically have the opportunity to develop with the help of these metaphors. The results show, in three of the book series, an abundance of labelling exercises related to the metaphor Arithmetic is object construction, mainly with images of geometric shapes. One book series reversely introduces fractions with The measuring stick metaphor and Arithmetic is motion along a path, with representations of number lines in focus. All in all, there is a significant variation between the textbooks, which could have consequences for instruction.This thesis shows the importance of theoretically distinguishing conceptual metaphor from extraneous metaphor, and of understanding their different roles in a teaching and learning context. The thesis also shows how the conceptual metaphors underlying the mathematical concepts describe different aspects of these concepts and that several conceptual metaphors need to be taken into account, together with a consideration of different degrees of reification of the mathematical objects. In addition, the thesis shows that metaphors, as they are understood in Conceptual metaphor theory, point to similar conceptual and discursive processes that can be found in Sfard’s (1991, 2008) more established theories on mathematical conceptualisation.
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| 2. |
- Kapp, Sebastian, et al.
(författare)
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Competitive adsorption of monoclonal antibodies and nonionic surfactants at solid hydrophobic surfaces
- 2015
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Ingår i: Journal of Pharmaceutical Sciences. - : John Wiley & Sons. - 0022-3549 .- 1520-6017. ; 104:2, s. 593-601
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Tidskriftsartikel (refereegranskat)abstract
- Two monoclonal antibodies from the IgG subclasses one and two were compared in their adsorption behavior with hydrophobic surfaces upon dilution to 10 mg/mL with 0.9% NaCl. These conditions simulate handling of the compounds at hospital pharmacies and surfaces encountered after preparation, such as infusion bags and i.v. lines. Total internal reflection fluorescence and quartz crystal microbalance with dissipation monitoring were used to follow and quantify this. Furthermore, the influence of the nonionic surfactant polysorbate 80 (PS80) on the adsorption process of these two antibodies was investigated. Despite belonging to two different IgG subclasses, both antibodies displayed comparable adsorption behavior. Both antibodies readily adsorbed in the absence of PS80, whereas adsorption was reduced in the presence of 30 mg/L surfactant. The sequence of exposure of the surfactant and protein to the surface was found to have a major influence on the extent of protein adsorption. Although only a fraction of adsorbed protein could be removed by rinsing with 30 mg/L surfactant solution, adsorption was entirely prevented when surfaces were pre-exposed to PS80
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| 3. |
- Schneider, Edith, et al.
(författare)
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MicroRNA-708 is a novel regulator of the Hoxa9 program in myeloid cells.
- 2020
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Ingår i: Leukemia. - : Springer Science and Business Media LLC. - 1476-5551 .- 0887-6924. ; 34, s. 1253-1265
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Tidskriftsartikel (refereegranskat)abstract
- MicroRNAs (miRNAs) are commonly deregulated in acute myeloid leukemia (AML), affecting critical genes not only through direct targeting, but also through modulation of downstream effectors. Homeobox (Hox) genes balance self-renewal, proliferation, cell death, and differentiation in many tissues and aberrant Hox gene expression can create a predisposition to leukemogenesis in hematopoietic cells. However, possible linkages between the regulatory pathways of Hox genes and miRNAs are not yet fully resolved. We identified miR-708 to be upregulated in Hoxa9/Meis1 AML inducing cell lines as well as in AML patients. We further showed Meis1 directly targeting miR-708 and modulating its expression through epigenetic transcriptional regulation. CRISPR/Cas9 mediated knockout of miR-708 in Hoxa9/Meis1 cells delayed disease onset in vivo, demonstrating for the first time a pro-leukemic contribution of miR-708 in this context. Overexpression of miR-708 however strongly impeded Hoxa9 mediated transformation and homing capacity in vivo through modulation of adhesion factors and induction of myeloid differentiation. Taken together, we reveal miR-708, a putative tumor suppressor miRNA and direct target of Meis1, as a potent antagonist of the Hoxa9 phenotype but an effector of transformation in Hoxa9/Meis1. This unexpected finding highlights the yet unexplored role of miRNAs as indirect regulators of the Hox program during normal and aberrant hematopoiesis.
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