Showing 481 - 490 of 583 Items
Diatom blooms in Harpswell Sound: seasonality, succession, and origin
Date: 2023-01-01
Creator: Charlie Francis O'Brien
Access: Open access
- Harpswell Sound (HS) is an inlet in northeastern Casco Bay that exerts control on Gulf of Maine ecosystem health, yet its complex phytoplankton community dynamics have not been characterized with sufficiently detailed analyses. In this research, high-resolution automated microscopy and current velocity observations were used to test the seasonality, ecological succession, bloom origin location, and potential toxicity of populations in HS between 2020 and 2022. Winter months could exhibit slow accumulation of diatom biovolume. Cold, salty surface water has net outflow in winter as nutrients from depth are replenished during net upwelling conditions, and populations could be exported from the inlet at the surface. Extreme current velocity variability in spring due to the Kennebec River plume in HS destabilizes spatially uniform populations. Warm, low-salinity surface water with net inflow in summer (net downwelling which retains populations at the head of the sound) corresponds with temporally separate dinoflagellate and diatom blooms. Large, multi-peaked spring and fall diatom blooms are recurrent, contrasting small, short-lived blooms in summer. A successional pattern from diatoms to dinoflagellates is confirmed for summer but refuted for other seasons. The hypothesis that diatom succession during all blooms in HS is characterized by large centric cells preceding small cells or pennate cells was explored but no clear pattern in decreasing cell size was observed. Observed tidal effects on biovolume concentration could mask that blooms develop at coherent times but spatially separated. A diverse community of toxic phytoplankton, including dinoflagellates and Pseudonitzschia, are observed throughout the year.
Eroding the Bedrock: The Future of Public Administration Without Chevron Deference
Date: 2024-01-01
Creator: Rose Keller
Access: Open access
- When Congress passes a bill, it produces words on a page. Who decides what those words mean? Historically, the onus of a statute’s interpretation has rested with the federal agencies charged with its implementation. The Chevron doctrine, a two-step standard that affords federal agencies significant latitude in interpreting their own enabling legislation, has been the applicable deference regime in statutory interpretation cases since 1984. Contrary to this tradition, recent Supreme Court jurisprudence has reasserted the primacy of the judiciary in statutory interpretation cases, often ignoring Chevron entirely. In 2023, the Court granted certiorari to Loper Bright Enterprises v. Raimondo, a case that explicitly asked the Court to consider overruling Chevron vs. NRDC, a foundational case in the field of administrative law. This thesis explores the implications of eroding deference to federal agencies through a case study of the Food and Drug Administration and two of its responsibilities. Ultimately, there are potentially negative consequences to limiting agency jurisdiction via eviscerating judicial deference that counsel a more discerning approach.
Blockholders and Their Effect on Project Value: An Empirical Approach of Understanding Ownership Concentration and Firm Value Using an Event Study Framework
Date: 2017-05-01
Creator: Xuanming Guo
Access: Open access
- This study uses an event study framework to find the relationship between ownership concentration and project value. I find that project value first increases with ownership concentration when block size, the percentage ownership of the largest blockholder, is smaller than 10%, then declines with ownership concentration when block size gets larger, and finally rises again when block size exceeds 30%. However, my research only suggests an ambiguous relationship between ownership concentration and firm value. Additionally, ownership concentration seems to affect both the timing of market responses and the market’s interpretation of large investment projects.

A Neighbor’s Impact: The Influence of Emotional Valence on Visual Word Processing Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2014-05-01
Creator: Marissa C Rosenthal
Access: Access restricted to the Bowdoin Community

The Power of In-Person Digital Repatriation: Returning Historic Photographs to West Greenland Communities This record is embargoed.
- Embargo End Date: 2029-05-15
Date: 2024-01-01
Creator: Agnes Macy
Access: Embargoed
Activation of Hydrogen by Sterically Modulated Coinage Metal Catalysts via Mutual Quenching of Hard/Soft Acid/Base Mismatches
Date: 2024-01-01
Creator: Zach Leibowitz
Access: Open access
- To mitigate the devastating environmental impacts of climate change in the coming decades, it is imperative that we replace the use of fossil fuels with renewable energy sources such as wind, solar, and hydroelectric. As these renewable energy sources are inherently intermittent, there exists a need for sustainable mechanisms to store renewable energy for later use. While the direct use of dihydrogen (H2) as a combustible fuel would allow for energy storage without the harmful release of carbon dioxide (CO2) upon combustion, the practicality of H2 as a synthetic fuel is limited by its low volumetric energy density. Combining sustainable H2 production (e.g. electrolysis using energy from renewable sources) with subsequent carbon fixation (e.g. the hydrogenation of CO2) represents a promising pathway to the sustainable production of high-density synthetic fuels. We hypothesize that such a process could be catalyzed by an IPr**-supported catalyst containing a hard/soft acid/base (HSAB) mismatch, with a polarizable coinage metal acting as a soft acid. As such, the aim of our project is the construction of a catalogue of IPr**-supported copper, silver, and gold catalysts that we anticipate will facilitate the heterolysis of dihydrogen and subsequent hydrogenation of CO2. In the present paper, we report the synthesis and characterization of an IPr**-silver complex which will serve as a precursor to many of our proposed HSAB mismatch catalysts and discuss next steps as we construct our catalogue of catalysts.
Looking Ahead With the World in Their Hands: The Postsecondary Aspirations of East Island Youth
Date: 2016-05-01
Creator: Abby E Roy
Access: Open access

Modeling Strategic Behavior in the U.S. Senate Using Ideal Points with Social Interactions Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2017-05-01
Creator: Tucker Gordon
Access: Access restricted to the Bowdoin Community

Hunter-Gatherers: The Survival of the Foraging Practice In Modern States Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2015-05-01
Creator: Tristan C Van Kote
Access: Access restricted to the Bowdoin Community
*dhéĝhōm,*héshr, and *wek (earth, blood, and speech): an archaeological, genetic, and linguistic exploration of Indo-European origins
Date: 2017-05-01
Creator: Lara Bluhm
Access: Open access
- This project investigates strategies for learning about prehistoric languages that have left no written records. It focuses upon the origins and expansion of the Indo-European language family (the world’s largest by total speaking population, today including most of the languages between Iceland and India) and its associated speakers, who likely emerged during the Neolithic from someplace in eastern Europe or western Asia. There are two primary hypotheses regarding the origins of these languages and the so-called Indo-Europeans themselves. In one, it is argued that they arose via the expansion of agriculture out of Anatolia and into Europe, c. 5000 BC. The other, and leading, hypothesis suggests instead that the languages spread through migrations of highly mobile pastoralists outward from the Black Sea steppes at the end of the Neolithic, c. 3000 BC. This project will explore the developing interface between archaeology, genetics, and linguistics in prehistoric resarch. There are three main chapters: (1) some background and historical context about Indo-European studies; (2) an examination of methodological interaction among archaeology, linguistics, and genetics; and (3) a survey of various archaeological, genetic, and linguistic data as they pertain to the Indo-Europeans and the above two hypotheses of their origins.