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- Redfors, Andreas, 1961-, et al.
(författare)
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The role of mathematics in the teaching and learning of physics
- 2014. - Part 2
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Ingår i: Ebook proceedings of the ESERA 2013 conference. - Nicosia, Cyprus : European Science Education Research Association. - 9789963700776 ; , s. 376-383
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Konferensbidrag (refereegranskat)abstract
- This paper discusses the role of mathematics in physics teaching andlearning. The intention and strength of science is to describe what happens in the realworld by organizing explanations through theories and theoretical models. It has beenwidely suggested that learning in science is influenced by views about the nature ofscientific knowledge. Furthermore, mathematics is an inherent part of theories andmakes powerful predictions of natural phenomena possible. Ability to use mathematicsto argue and prove results is central in physics. Students have been found tostruggle with physics problems where they need to relate mathematically formulatedtheoretical models to the real world. This project has explored the role of mathematicsfor physics teaching and learning in upper-secondary school through investigations ofrelations made during physics lessons (lectures, problem solving and lab-work)between The real world – Theoretical models – Mathematics. A preliminary analysisindicate that there are some connections made by students and teacher betweentheories and the real world, but the bulk of the discussion in the classroom is concerningthe relation between theoretical models and mathematics, which is in linewith earlier research on problem solving. The preliminary results reported on hereindicate that this also holds true for all the investigated organisational forms lectures,problem solving in groups and lab-work. A finalized and extended analysis will bepublished elsewhere.
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| 4. |
- Redfors, Andreas, et al.
(författare)
-
The role of mathematics in the teaching and learning of physics
- 2014
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Konferensbidrag (övrigt vetenskapligt/konstnärligt)abstract
- This paper discusses the role of mathematics in physics teaching andlearning. The intention and strength of science is to describe what happens in the realworld by organizing explanations through theories and theoretical models. It has beenwidely suggested that learning in science is influenced by views about the nature ofscientific knowledge. Furthermore, mathematics is an inherent part of theories andmakes powerful predictions of natural phenomena possible. Ability to use mathematicsto argue and prove results is central in physics. Students have been found tostruggle with physics problems where they need to relate mathematically formulatedtheoretical models to the real world. This project has explored the role of mathematicsfor physics teaching and learning in upper-secondary school through investigations ofrelations made during physics lessons (lectures, problem solving and lab-work)between The real world – Theoretical models – Mathematics. A preliminary analysisindicate that there are some connections made by students and teacher betweentheories and the real world, but the bulk of the discussion in the classroom is concerningthe relation between theoretical models and mathematics, which is in linewith earlier research on problem solving. The preliminary results reported on hereindicate that this also holds true for all the investigated organisational forms lectures,problem solving in groups and lab-work. A finalized and extended analysis will bepublished elsewhere.
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- Andersson, Markus, 1981, et al.
(författare)
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Vinylimidazole copolymers: coordination chemistry, solubility, and cross-linking as function of Cu2+ and Zn2+ complexation
- 2011
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Ingår i: Colloid and Polymer Science. - : Springer Science and Business Media LLC. - 0303-402X .- 1435-1536. ; 289:12, s. 1361-1372
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Tidskriftsartikel (refereegranskat)abstract
- P(1-VIm-co-MMA) copolymers with 4 or 44 wt.% 1-VIm (abbreviated PVM-4 and PVM-44) where polymerized from 1-VIm (1-vinylimidazole) and methylmethacrylate with azobisisobutyronitrile as initiator and reacted with either Cu(2+) or Zn(2+). The resulting coordinated polymer complexes were studied using ICP-AES, CP/MAS (13)C NMR, conductivity measurements, vibrational spectroscopy (mid-FTIR and far-FTIR), DSC, and EPR. It was established by ICP-AES, CP/MAS (13)C NMR, conductivity, mid-FTIR and EPR measurements that the transition metal ions in the complexes were exclusively coordinated by the imidazole ligand. The coordination geometry is square planar with regard to Cu(II) complexes. The strong interaction between the polymeric imidazole ligand and the transition metal ion cross-links the system, resulting in augmentation of T (g) (the glass transition temperature), especially for copolymers with high relative amount of 1-VIm. The effect of changing metal ion is more complicated and depends on both the strength of the coordinate interaction as well as the coordination number. The solubility of the coordinate polymer complex in conventional solvents is low due to the coordinate cross-links. However, the coordinate polymer complexes are soluble in strongly coordinating solvents such as acetonitrile and dimethylsulfoxide.
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- Farkas, Daniel, et al.
(författare)
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Cloning, expression and purification of the luminal domain of spinach photosystem 1 subunit PsaF functional in binding to plastocyanin and with a disulfide bridge required for folding
- 2011
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Ingår i: Protein Expression and Purification. - San Diego : Academic Press. - 1046-5928 .- 1096-0279. ; 78:2, s. 156-166
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Tidskriftsartikel (refereegranskat)abstract
- The photosystem 1 subunit PsaF is involved in the docking of the electron-donor proteins plastocyanin and cytochrome c6 in eukaryotic photosynthetic organisms. Here we report the expression, purification and basic characterization of the luminal domain of spinach PsaF, encompassing amino-acid residues 1-79. The recombinant protein was expressed in Escherichia coli BL21 (DE3) using a pET32 Xa/LIC thioredoxin fusion system. The thioredoxin fusion protein contained a His6 tag and was removed and separated from PsaF through proteolytic digestion by factor Xa followed by immobilized metal affinity chromatography. Further purification with size-exclusion chromatography resulted in a final yield of approximately 6 mg PsaF from one liter growth medium. The correct identity after the factor Xa treatment of PsaF was verified by FT-ICR mass spectrometry which also showed that the purified protein contains an intact disulfide bridge between Cys residues 6 and 38. Secondary structure and folding was further explored using far-UV CD spectroscopy indicating a α-helical content in agreement with the 3.3 Å-resolution crystal structure of photosystem I Ref. [5] and a helix-coil transition temperature of 29 °C. Thermofluorescence studies showed that the disulfide bridge is necessary to keep the overall fold of the protein and that hydrophobic regions become exposed at 50-65 °C depending on the ionic strength. The described expression and purification procedure can be used for isotopic labeling of the protein and 15N-HSQC NMR studies indicated a slow or intermediate exchange between different conformations of the prepared protein and that it belongs to the molten-globule structural family. Finally, by using a carboxyl- and amine-reactive zero-length crosslinker, we have shown that the recombinant protein binds to plastocyanin by a specific, native-like, electrostatic interaction, hence, confirming its functionality.
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