Showing 21 - 24 of 24 Items
Using metabolic oligosaccharide engineering to induce immune-mediated cell killing of bacterial pathogens Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2020-01-01
Creator: Brendan H. Pulsifer
Access: Access restricted to the Bowdoin Community
Living Upstream: Kennebec River Influence on Nutrient Regimes and Phytoplankton Communities in Harpswell Sound
Date: 2020-01-01
Creator: Siena Brook Ballance
Access: Open access
- Phytoplankton underpin marine trophic systems and biogeochemical cycles. Estuarine and coastal phytoplankton account for 40-50% of global ocean primary productivity and carbon flux making it critical to identify sources of variability. This project focuses on the Kennebec River and Harpswell Sound, a downstream, but hydrologically connected coastal estuary, as a case study of temperate river influence on estuarine nutrient regimes and phytoplankton communities. Phytoplankton pigments and nutrients were analyzed from water samples collected monthly at 8 main-stem rivers stations (2011-2013) and weekly in Harpswell Sound (2008-2017) during ice-free months. Spatial bedrock and land use impacts on river nutrients were investigated at sub-watershed scales using GIS. Spatial analysis reveals a 10-fold increase in measured phytoplankton biomass across the Kennebec River’s saltwater boundary, which demonstrates ocean-driven phytoplankton variability in the lower river. The biomass pattern is accompanied by a transition in phytoplankton community structure with respect to which groups co-occur (diatoms, chlorophytes, and cryptophytes) and which are unique (dinoflagellates in Harpswell). Upstream, the timing of each community depends on land-use proximity and seasonal discharge. In Harpswell Sound, the nutrient regime and phytoplankton community structure vary systematically: first diatoms strip silicate, then dinoflagellates utilize nitrate, followed by chlorophytes and cryptophytes that utilize available phosphate. These findings reveal, for the first time, patterns in phytoplankton communities and nutrient dynamics across the fresh to salt water interface. Ultimately the Kennebec River phytoplankton communities and nutrient regimes are distinct, and the river is only a source of silicate to Harpswell Sound.
Isolation of Cell Adhesion Mutations in Arabidopsis thaliana Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2020-01-01
Creator: Frances DeCamp Hobart Zorensky
Access: Access restricted to the Bowdoin Community
Bacterial Coat of Armor: Probing how Glycan Biosynthesis in Helicobacter pylori Modulates Host Immune Recognition Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2022-01-01
Creator: Francis Jacob Kassama
Access: Access restricted to the Bowdoin Community