Showing 5651 - 5660 of 5831 Items
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.

Date: 2020-01-01
Creator: Luca Ostertag-Hill
Access: Access restricted to the Bowdoin Community
Date: 1944-01-01
Access: Open access
- Bowdoin College Bulletin no. 269
Date: 1936-01-01
Access: Open access
- Bowdoin College Bulletin no. 228
Date: 1945-01-01
Access: Open access
- Bowdoin College Bulletin no. 273
Date: 1993-01-01
Creator: A. Bean, J. Gronberg, R. Kutschke, S. Menary, R. J., Morrison, H. Nelson, J. Richman, H. Tajima, D. Schmidt, D. Sperka, M. Witherell, M. Procario, S. Yang, M. Daoudi, W. T. Ford, D. R. Johnson, K. Lingel, M. Lohner, P. Rankin, J. G. Smith, J. P. Alexander, C. Bebek, K. Berkelman, D. Besson, T. E. Browder, D. G. Cassel, D. M. Coffman, P. S. Drell, R. Ehrlich, R. S. Galik, M. Garcia-Sciveres
Access: Open access
- A search for the lepton mumber violating decay of the τ lepton to the γμ final state has been performed with the CLEO II detector at the Cornell e+e- storage ring CESR. In a data sample that corresponds to an integrated luminosity of 1.55 fb-1, we observe no candidates in the signal region. We thus determine an upper limit of B(τ-→γμ-)<4. 2×10-6 at 90% confidence level. © 1993 The American Physical Society.
Date: 2020-01-01
Creator: Diego Rafael Grossmann
Access: Open access
- The Colombo-Venezuelan Border Through the Lens of the Colombian Press examines the dominant Colombian press coverage of crises of sovereignty at the Colombo-Venezuelan border, Venezuelan migration, and the February 2019 attempt to introduce humanitarian aid into Venezuela, as seen in El Espectador and El Tiempo’s coverage from the period of August 2018-November 2019. Through theories of nations and power, this thesis reveals the divergent editorial lines and dominant narratives within each newspaper’s construction of the relation between the Colombian and Venezuelan nations, states, and their people. The study details how both newspapers construct different “truths” through divergent constructions of similar events in a manner coherent with the ideological affinities and conceptions of Colombian national identity held by their respective audiences and editorial leadership, constrained further by economic factors. The thesis is split into three main chapters. Chapter 1 addresses the construction of Colombian nationhood rooted in militarism and the presentation of the Colombian state as a protector in El Tiempo’s coverage concerning binational tensions at the border. Chapter 2 traces the coverage regarding Venezuelan migration to Colombia within El Espectador, detailing the conception of national identity rooted in liberal-democratic values that the newspaper constructs and appeals to. Chapter 3 considers both newspaper’s coverage of the attempt to introduce humanitarian aid into Venezuela in 2019. Ultimately, this thesis argues that the discursive actor––and construction––of Venezuela permits the “imagining” of the Colombian nation, a project framed through a discussion of the Colombian conflict and official commitments to multiculturalism by the Colombian state.
Date: 1948-01-01
Access: Open access
- Bowdoin College Bulletin no. 287
Date: 1950-01-01
Access: Open access
- Bowdoin College Bulletin no. 295