Uppbygging orðaforða pólskra tvítyngdra barna í leikskóla og á yngri stigum grunnskóla á Íslandi

Ritgerðin er lokaverkefni til B.A. prófs í íslensku sem öðru máli. Ritgerðin fjallar um uppbyggingu orðaforða og hvaða aðferðir ég nota til að kenna pólskumælandi börnum íslensku. Ritgerðin inniheldur fimm kafla. Í inngangi kemur fram kveikjan að verkefninu og mikilvægi orðaforðakennslu tvítyngdra barna. Þá er tekin fyrir skilgreining á móðurmáli, orðaforða og grunnorðaforða. Í aðferðafræðikafla er farið yfir nokkrar kennsluaðferðir. Síðan er tekið dæmi af pólskum nemanda í fimmta bekk sem ég kenni og hvaða kennsluaðferðir hafa reynst okkur vel. Að lokum eru umræður og lokaorð

Structure–function relationships of two paralogous single-stranded DNA-binding proteins from Streptomyces coelicolor : implication of SsbB in chromosome segregation during sporulation

The linear chromosome of Streptomyces coelicolor contains two paralogous ssb genes, ssbA and ssbB. Following mutational analysis, we concluded that ssbA is essential, whereas ssbB plays a key role in chromosome segregation during sporulation. In the ssbB mutant, 0% of spores lacked DNA. The two ssb genes were expressed differently; in minimal medium, gene expression was prolonged for both genes and significantly upregulated for ssbB. The ssbA gene is transcribed as part of a polycistronic mRNA from two initiation sites, 163 bp and 75 bp upstream of the rpsF translational start codon. The sbB gene is transcribed as a monocistronic mRNA, from an unusual promoter region, 73 bp upstream of the AUG codon. Distinctive DNA-binding affinities of single-stranded DNA-binding proteins monitored by tryptophan fluorescent quenching and electrophoretic mobility shift were observed. The crystal structure of SsbB at 1.7A ° resolution revealed a common OB-fold, lack of the clamp-like structure conserved in SsbA and previously unpublished S-S bridges between the A/B and C/D subunits. This is the first report of the determination of paralogous singlestranded DNA-binding protein structures from the same organism. Phylogenetic analysis revealed frequent duplication of ssb genes in Actinobacteria, whereas their strong retention suggests that they are involved in important cellular functions

Structure–function relationships of two paralogous single-stranded DNA-binding proteins from Streptomyces coelicolor : implication of SsbB in chromosome segregation during sporulation

The linear chromosome of Streptomyces coelicolor contains two paralogous ssb genes, ssbA and ssbB. Following mutational analysis, we concluded that ssbA is essential, whereas ssbB plays a key role in chromosome segregation during sporulation. In the ssbB mutant, 0% of spores lacked DNA. The two ssb genes were expressed differently; in minimal medium, gene expression was prolonged for both genes and significantly upregulated for ssbB. The ssbA gene is transcribed as part of a polycistronic mRNA from two initiation sites, 163 bp and 75 bp upstream of the rpsF translational start codon. The sbB gene is transcribed as a monocistronic mRNA, from an unusual promoter region, 73 bp upstream of the AUG codon. Distinctive DNA-binding affinities of single-stranded DNA-binding proteins monitored by tryptophan fluorescent quenching and electrophoretic mobility shift were observed. The crystal structure of SsbB at 1.7A ° resolution revealed a common OB-fold, lack of the clamp-like structure conserved in SsbA and previously unpublished S-S bridges between the A/B and C/D subunits. This is the first report of the determination of paralogous singlestranded DNA-binding protein structures from the same organism. Phylogenetic analysis revealed frequent duplication of ssb genes in Actinobacteria, whereas their strong retention suggests that they are involved in important cellular functions

Cell division and DNA segregation in Streptomyces: how to build a septum in the middle of nowhere?

Microbial Biotechnolog

Streptomyces morphogenetics: dissecting differentiation in a filamentous bacterium.

During the life cycle of the filamentous bacteria Streptomyces, morphological differentiation is closely integrated with fundamental growth and cell-cycle processes, as well as with truly complex multicellular behaviour that involves hormone-like extracellular signalling and coordination with an extraordinarily diverse secondary metabolism. Not only are the bacterial cytoskeleton and the machineries for cell-wall assembly, cell division and chromosome segregation reorganized during sporulation, but the developmental programme of these fascinating organisms also has many unusual elements, including the formation of a sporulating aerial mycelium and the production of a surfactant peptide and a hydrophobic sheath that allow cells to escape from the surface tension of the growth medium