Learning environmental concepts in primary school for sustainable development

This paper explores environmental education research in primary school. The longitudinal study started in 2003, with 29 children nine years of age, in a city in southern Sweden. The teacher works with projects in science and technology to stimulate the pupils’ interest and participation in environmental education. Semi-structured interviews with the young pupils have been carried out. In order to analyse the classroom communication between the teacher and the children and also among the children, videotaped sequences from the lessons are collected, in which the Socratic dialogue is practiced. Stimulated recall as a method is also used to find out the teacher’s reactions during the lessons. In order to catch environmental details as well as a holistic perspective, the Earth’s system model is used in the analysis, e.g. the lithosphere, the atmosphere and the hydrosphere as well as the biosphere and the technosphere. It was observed that the children are able to argue about possibilities to change different daily routines in different ways, which reduce disturbances to the environment. Some pupils can see the connection between the increasing greenhouse effect and pollution from the cars. Others can see relations between increasing temperature and melting polar caps. In stimulated recall the teacher points out possible connections in the Earth system and in environmental learning. This material is one part of an ongoing longitudinal doctoral study and the videotaped sequences have been caught from year 2003 to 2006. The interviews with the children have been taped every spring from year 2003 to 2006

Via overexpression in the yeast Pichia pastoris to enhanced enantioselectivity : a new chapter in the application of pig liver esterase

Lipases and Esterases can be used as efficient biocatalysts for the preparation of a wide variety of optically pure compounds. Whereas a range of lipases - especially of microbial origin - are commercially available, only a few esterases can be obtained for the kinetic resolution of racemates or desymmetrization. In the majority of publications, pig liver esterase (PLE) is used, which is isolated from pig liver by extraction. Although it could be demonstrated, that this preparation can convert a broad range of compounds at partially very high stereoselectivity, its application is encountered with a number of disadvantages.Lipasen und Esterasen lassen sich als effiziente Biokatalysatoren zur Darstellung einer Vielzahl optisch aktiver Verbindungen einsetzen. Während jedoch eine ganze Reihe von Lipasen - insbesondere mikrobiellen Ursprungs - kommerziell erhältlich sind, gibt es nur sehr wenige Esterasen, die für den Einsatz in einer Racematspaltung bzw. Asymmetrisierung zur Verfügung stehen. In der Mehrzahl der Publikationen wird Schweineleberesterase (PLE, pig liver esterase) verwendet, die durch Extraktion aus Schweineleber gewonnen wird. Obwohl gezeigt werden konnte, dass mit dieser Präparation eine Vielzahl von Verbindungen mit teilweise sehr hoher Stereoselektivität umgesetzt werden können, ist dessen Verwendung doch mit einer Reihe von Nachteilen verbunden

Cloning and sequencing of the Bet v 1-homologous allergen Fra a 1 in strawberry (Fragaria ananassa) shows the presence of an intron and little variability in amino acid sequence

The Fra a I allergen in strawberry (Fragaria ananassa) is homologous to the major birch pollen allergen Bet v 1, which has numerous isoforms differing in terms of amino acid sequence and immunological impact. To map the extent of sequence differences in the Fra a I allergen, PCR cloning and sequencing was applied. Several genomic sequences of Fra a 1, with a length of either 584, 591 or 594 nucleotides, were obtained from three different strawberry varieties. All contained one intron, with the length of either 10 1 or 110 nucleotides. By sequencing 30 different clones, eight different DNA sequences were obtained, giving in total five potential Fra a I protein isoforms, with high sequence similarity (> 97% sequence identity) and only seven positions of amino acid variability, which were largely confirmed by mass spectrometry of expressed proteins. We conclude that the sequence variability in the strawberry allergen Fra a I is small, within and between strawberry varieties, and that multiple spots, previously detected in 2DE, are presumably due to differences in post-translational modification rather than differences in amino acid sequence. The most abundant Fra a I isoform sequence, recombinantly expressed in Escherichia coli after removal of the intron, was recognized by IgE from strawberry allergic patients. It cross-reacted with antibodies to Bet v I and the homologous apple allergen Mal d 1 (61 and 78% sequence identity, respectively), and will be used in further analyses of variation in Fra a 1-expression. (c) 2006 Elsevier Ltd. All rights reserved

An Investigation of the Interaction of Co-Solvent with Substrates in the Pig Liver Esterase-Catalyzed Hydrolysis of Malonate Esters

Previously, we have reported the effect of several co-solvents, including ethanol, on the enantioselective outcome of pig liver esterase (PLE) hydrolysis reactions. The greatest improvements were observed in those substrates that contained an atom capable of forming a hydrogen bond in the sidechain portion of the molecule. To further explore the interaction between substrate and ethanol, a second series of substrates were synthesized, in which the hydrogen bonding atoms of the side chain were modified, and subjected to PLE hydrolysis. Substrates containing atoms capable of forming hydrogen bonds showed the largest equilibrium constants. However, a large equilibrium constant did not always produce significant changes in enantioselectivity as hypothesized. Finally, molecular modeling experiments were performed to obtain a better understanding of the interactions. These experiments revealed that there are substrate–enzyme interactions that can be influenced by the addition of ethanol