Land cover and land use analysis in coastal Bangladesh

Land cover and land use (LCLU) analysis is a central determinant of the current and future relationship between people and local ecosystem services. It provides the spatial basis for the integrated analysis of the study area. Historical change (1989–2010) is identified using classification techniques based on available satellite imagery supported by other data. Nine categories of LULC are identified; water, Bagda (brackish shrimp farming), Galda (freshwater prawn farming), agriculture (non-waterlogged), agriculture (waterlogged), wetlands and mudflats, mangrove, rural settlements and major urban areas. The analysis shows an increase in aquaculture (mainly replacing rice fields), with agriculture becoming more intermixed with settlements. Future LULC scenarios are determined based on stakeholder narratives

Replisome speed determines the efficiency of the Tus-Ter replication termination barrier

In all domains of life, DNA synthesis occurs bidirectionally from replication origins. Despite variable rates of replication fork progression, fork convergence often occurs at specific sites1. Escherichia coli sets a \u27replication fork trap\u27 that allows the first arriving fork to enter but not to leave the terminus region2, 3, 4, 5. The trap is set by oppositely oriented Tus-bound Ter sites that block forks on approach from only one direction3, 4, 5, 6, 7. However, the efficiency of fork blockage by Tus-Ter does not exceed 50% in vivo despite its apparent ability to almost permanently arrest replication forks in vitro8, 9. Here we use data from single-molecule DNA replication assays and structural studies to show that both polarity and fork-arrest efficiency are determined by a competition between rates of Tus displacement and rearrangement of Tus-Ter interactions that leads to blockage of slower moving replisomes by two distinct mechanisms. To our knowledge this is the first example where intrinsic differences in rates of individual replisomes have different biological outcomes