Showing 471 - 480 of 583 Items
Examining the Predictive Value of Anxiety, Depression, and Suicidal Ideation Screening in Determining Psychosis Risk This record is embargoed.
- Embargo End Date: 2028-05-16
Date: 2023-01-01
Creator: Tara M. D. Mullen
Access: Embargoed
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.
The role of modulation on the pyloric neurons and the neuromuscular junction in a pattern generator-effector system
Date: 2023-01-01
Creator: Jackie Seddon
Access: Open access
- Neuromodulation, the process of altering the electrical outputs of a neuron or neural circuit, allows an organism to control its physiological processes to meet the needs of both its internal and external environments. Previous work shows that the pyloric pattern of the kelp crab (Pugettia producta) stomatogastric nervous system (STNS) neurons responded to fewer neuromodulators than the Jonah crab (Cancer borealis). Since the kelp crab diet primarily eats kelp, it is possible that the movements of the foregut that control digestion may require less flexibility in functional output compared to an opportunistic feeder. To determine whether a reduced flexibility is correlated with diet, this study compared the modulatory responses in Pugettia to two other species of majoid crabs: Chionoecetes opilio and Libinia emarginata, which are both opportunistic feeders. Pooled data for this study found that Libinia and Chionoecetes responded to all twelve modulators tested. When considering the effect of modulators on stomatogastric ganglion (STG) motor outputs, we must consider whether these modulators also alter the excitatory junction potentials (EJPs) at the neuromuscular junction (NMJ), and whether there are differences in responses across species. To test this, the dorsal gastric nerve (dgn) was stimulated while recording intracellularly from the muscle fibers of the associated gm4 muscles. The NMJ of the gm4 in Cancer borealis did not appear to be broadly modulated, as only RPCH and CabTRP showed increases in amplitude, and RPCH decreased facilitation at 5 Hz.
The influence of Toll 7 on the neuroplasticity of auditory neurons in the Mediterranean field cricket (Gryllus bimaculatus) This record is embargoed.
- Embargo End Date: 2028-05-16
Date: 2023-01-01
Creator: Brooke Asherman
Access: Embargoed
Characterization of Spaetzle-Toll Ligand-Receptor Pairs in Gryllus bimaculatus Access to this record is restricted to members of the Bowdoin community. Log in here to view.
- Restriction End Date: 2028-06-01
Date: 2023-01-01
Creator: Tabarak Al Musawi
Access: Access restricted to the Bowdoin Community
New Institutional Economics: Political Institutions and Divergent Development in Costa Rica and Honduras
Date: 2022-01-01
Creator: Maynor Alberto Loaisiga Bojorge
Access: Open access
- For most of their histories, Costa Rica and Honduras were primarily agricultural societies with little economic diversification. However, around 1990, after the implementation of Washington Consensus reforms, the economies of both nations began to diverge. Costa Rica’s economy rapidly expanded for the following 30 years, while Honduras remained stagnant. Through a New Institutional Economics approach, I argue that institutional differences between Costa Rica and Honduras are responsible for the impressive economic growth Costa Rica has been able to achieve in the past few decades. Specifically, early political developments in Costa Rica have deeply imbedded relatively egalitarian values into the population, helping shape formal and informal inclusive political institutions. Meanwhile, Honduras experienced the development of extractive political institutions, as political and economic power was heavily concentrated in the hands of a select few. These political institutions were crucial during the implementation stages of Washington Consensus reforms, as strong and inclusive political institutions attracted Foreign Direct Investment that helped propel the Costa Rican economy and materialize its position as an outlier in the region. In contrast, lack of institutional guarantees discouraged foreign investors from investing money into the Honduran economy. Through a deep dive into the political histories of both nations, from European discovery to modernity, I conclude that the political institutions of these Central American nations have determined their economic growth paths.
Surface Soil Stocks: Peat Development and Soil Carbon Storage on South Baffin Island, Nunavut, Canada This record is embargoed.
- Embargo End Date: 2028-05-18
Date: 2023-01-01
Creator: Ana Gunther
Access: Embargoed
Narration, Nation et Nationalisme dans les récits d’enfance de Mouloud Feraoun et Mohammed Dib
Date: 2022-01-01
Creator: Reed Foehl
Access: Open access
- During the mid-20th century, a new form of Algerian literature emerged, thematically detached yet linguistically tied to France. Novelists aligned with this littérature algérienne de langue française used their narrative power to expose the atrocities of the colonial period, while emphasizing the rising nationalist spirit throughout the country. A peculiar aspect of this national literature is the presence of a child protagonist. Many of Algeria’s most prominent authors centered their first novels on a young boy. This leads to my central question: does the récit d’enfance (childhood narrative) possess certain qualities that lend it useful for representing ubiquitous suffering, as well as an imminent national awakening. My research focuses on two Algerian novelists, Mouloud Feraoun and Mohammed Dib, who employ the récit d’enfance for different aims. In this paper, I first define the récit d’enfance and show how Feraoun and Dib implement this literary style. Secondly, I argue that Mohammed Dib’s trilogy is distinctly political. Employing the critical theories of Frantz Fanon and Benedict Anderson, I contend that Dib’s trilogy, published between 1952-1957, is a littérature de combat (combat literature). Although Feraoun’s publication of Le Fils du Pauvre in 1950 inaugurated Franco-Algerian literature, his work is more reflective than political. Comparing Feraoun and Dib’s early work, allows me to expose the disparate narratives arising in the decade prior to Algerian independence. Their portrayal of colonial oppression, as well as the courage and ambition of an exploited people, remains useful when studying models of colonial and post-colonial nationalism and nation-state.
Testing conservation of an mRNA transport pathway in yeast Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2021-01-01
Creator: Kyu Young "Kevin" Chi
Access: Access restricted to the Bowdoin Community
The Role of ELMO5 in Arabidopsis thaliana Cell Adhesion
Date: 2022-01-01
Creator: Isabel Kristina Ball
Access: Open access
- Plant cell growth and development relies on proper cellular adhesion. As the extracellular matrix serves as the area of connection between two cells, its synthesis and maintenance are essential for cellular adhesion. The middle lamella region, the layer of the extracellular matrix between two adjacent cell walls, is diffuse with the polysaccharide pectin due to its delivery by Golgi vesicles early during cell division. A Ruthenium Red screen for cellular adhesion mutants identified the family of 5 ELMO proteins that are critical for proper cellular adhesion. To further our understanding of plant cellular adhesion and pathways of pectin synthesis and modification, this work investigates ELMO5. Plants homozygous for a T-DNA insertion in ELMO5 and a new deletion mutant allele generated using CRSPR do not have a cellular adhesion phenotype, suggesting it is either not critical for cellular adhesion or is redundant with another gene. Redundancy within the ELMO family is identified through the analysis of double mutants of elmo5 and each of the other four elmo genes. Both elmo1-/- elmo5-/-and elmo4-/- elmo5-/-mutants have a visibly worse cellular adhesion defect phenotype, suggesting partial redundancy through the ELMO family. The mutants are also rescued by growth on agar, pointing to the importance of turgor pressure and osmotic potential in modulating cellular adhesion. Both ELMO4 and ELMO5 were found to localize to the Golgi using a GFP fusion, consistent with a role for ELMOs as scaffold for pectin biosynthesis.