Showing 551 - 600 of 5840 Items
The impact of temperature on the sea star oscillatory gait This record is embargoed.
- Embargo End Date: 2025-05-14
Date: 2020-01-01
Creator: Emma Victoria Bertke
Access: Embargoed
Conifer forest photosynthetic seasonality: exploring the effect of winter severity and the efficacy of different remote sensing methodologies This record is embargoed.
- Embargo End Date: 2026-05-20
Date: 2021-01-01
Creator: Anneka Florence Williams
Access: Embargoed
Bowdoin College Catalogue (1957-1958)
Date: 1958-01-01
Access: Open access
- Bowdoin College Bulletin no. 326
Coordination of distinct but interacting rhythmic motor programs by a modulatory projection neuron using different co-transmitters in different ganglia
Date: 2013-05-01
Creator: Molly A. Kwiatkowski, Emily R. Gabranski, Kristen E. Huber, M. Christine Chapline, Andrew E., Christie, Patsy S. Dickinson
Access: Open access
- While many neurons are known to contain multiple neurotransmitters, the specific roles played by each co-transmitter within a neuron are often poorly understood. Here, we investigated the roles of the co-transmitters of the pyloric suppressor (PS) neurons, which are located in the stomatogastric nervous system (STNS) of the lobster Homarus americanus. The PS neurons are known to contain histamine; using RT-PCR, we identified a second co-transmitter as the FMRFamide-like peptide crustacean myosuppressin (Crust-MS). The modulatory effects of Crust-MS application on the gastric mill and pyloric patterns, generated in the stomatogastric ganglion (STG), closely resembled those recorded following extracellular PS neuron stimulation. To determine whether histamine plays a role in mediating the effects of the PS neurons in the STG, we bath-applied histamine receptor antagonists to the ganglion. In the presence of the antagonists, the histamine response was blocked, but Crust-MS application and PS stimulation continued to modulate the gastric and pyloric patterns, suggesting that PS effects in the STG are mediated largely by Crust-MS. PS neuron stimulation also excited the oesophageal rhythm, produced in the commissural ganglia (CoGs) of the STNS. Application of histamine, but not Crust-MS, to the CoGs mimicked this effect. Histamine receptor antagonists blocked the ability of both histamine and PS stimulation to excite the oesophageal rhythm, providing strong evidence that the PS neurons use histamine in the CoGs to exert their effects. Overall, our data suggest that the PS neurons differentially utilize their co-transmitters in spatially distinct locations to coordinate the activity of three independent networks. © 2013. Published by The Company of Biologists Ltd.
Bowdoin College Catalogue (1966-1967)
Date: 1967-01-01
Access: Open access
- Bowdoin College Bulletin no. 362
A hydrophobic, carboxy-proximal region of a light-harvesting chlorophyll a/b protein is necessary for stable integration into thylakoid membranes.
Date: 1989-01-01
Creator: B. D. Kohorn, E. M. Tobin
Access: Open access
- Proteins synthesized as soluble precursors in the cytoplasm of eukaryotic cells often cross organellar membrane barriers and then insert into lipid bilayers. One such polypeptide, the light-harvesting chlorophyll a/b-binding protein (LHCP), must also associate with pigment molecules and be assembled into the photosystem II light-harvesting complex in the chloroplast thylakoid membrane. A study of the import of mutant LHCPs into isolated chloroplasts has shown that a putative alpha-helical membrane-spanning domain near the carboxy terminus (helix 3) is essential for the stable insertion of LHCP in the thylakoid. Protease digestion experiments are consistent with the carboxy terminus of the protein being in the lumen. This report also shows that helix 3, when fused to a soluble protein, can target it to the thylakoids of isolated, intact chloroplasts. Although helix 3 is required for the insertion of LHCP and mutant derivatives into the thylakoid, the full insertion of helix 3 itself requires additionally the presence of other regions of LHCP. Thus, LHCP targeting and integration into thylakoid membranes requires a complex interaction involving a number of different domains of the LHCP polypeptide.
A Men’s College with Women: Masculinity, Sexist Laughter, and Stories of Solidarity during Bowdoin College’s Transition to Coeducation, 1969-1975 Access to this record is restricted to members of the Bowdoin community. Log in here to view.
- Restriction End Date: 2025-06-01
Date: 2020-01-01
Creator: Emma D. Kellogg
Access: Access restricted to the Bowdoin Community
Nonlinear excitations in magnetic lattices with long-range interactions
Date: 2019-06-24
Creator: Miguel Molerón, C. Chong, Alejandro J. Martínez, Mason A. Porter, P. G., Kevrekidis, Chiara Daraio
Access: Open access
- We study - experimentally, theoretically, and numerically - nonlinear excitations in lattices of magnets with long-range interactions. We examine breather solutions, which are spatially localized and periodic in time, in a chain with algebraically-decaying interactions. It was established two decades ago (Flach 1998 Phys. Rev. E 58 R4116) that lattices with long-range interactions can have breather solutions in which the spatial decay of the tails has a crossover from exponential to algebraic decay. In this article, we revisit this problem in the setting of a chain of repelling magnets with a mass defect and verify, both numerically and experimentally, the existence of breathers with such a crossover.
Sign changes of Fourier coefficients of Hilbert modular forms
Date: 2014-01-01
Creator: Jaban Meher, Naomi Tanabe
Access: Open access
- Sign changes of Fourier coefficients of various modular forms have been studied. In this paper, we analyze some sign change properties of Fourier coefficients of Hilbert modular forms, under the assumption that all the coefficients are real. The quantitative results on the number of sign changes in short intervals are also discussed. © 2014 Elsevier Inc.
Dendrites of Cardiac Ganglion Regulate Heartbeat of American Lobster, Homarus americanus, Through Stretch Feedback
Date: 2014-05-01
Creator: Mara R Chin-Purcell
Access: Open access
- Central pattern generators are neuronal networks that produce reliable rhythmic motor output. A simple pattern generator, known as the cardiac ganglion (CG), controls the heart of the American lobster, Homarus americanus. Previous studies have suggested that stretch feedback relays information to the cardiac ganglion about the degree of filling in the heart, and that this feedback is mediated by stretch-sensitive dendrites extending from CG neurons. I sought to determine the mechanisms behind this stretch feedback pathway. One hundred second extension pyramids were applied to each heart while amplitude and frequency of contractions were recorded; 87% of hearts responded to stretch with a significant increase in frequency of contractions. To ascertain the role of dendrites in this feedback pathway, the accessible branches along the trunk of the CG were severed, de-afferenting the CG. In de-afferented hearts, stretch sensitivity was significantly less than in intact hearts, suggesting that the dendrites extending from the CG are essential for carrying stretch feedback information. To separate the effects of active and passive forces of heart contraction on stretch sensitivity, the CG was de-efferented by severing the motor nerves that induce muscle contraction. Hearts with only anterolateral nerves cut or with all four efferents cut were significantly less stretch sensitive than controls. These results indicate that the CG is sensitive to active stretch of each contraction. Hearts with reduced stretch feedback had more irregular frequency of contractions, indicating that a role of stretch feedback in the cardiac system may be to maintain a regular heart rate.
Combinatorial and metric properties of Thompson's group t
Date: 2009-02-01
Creator: José Burillo, Sean Cleary, Melanie Stein, Jennifer Taback
Access: Open access
- We discuss metric and combinatorial properties of Thompson's group T, including normal forms for elements and unique tree pair diagram representatives. We relate these properties to those of Thompson's group F when possible, and highlight combinatorial differences between the two groups. We define a set of unique normal forms for elements of T arising from minimal factorizations of elements into natural pieces. We show that the number of carets in a reduced representative of an element of T estimates the word length, that F is undistorted in T, and we describe how to recognize torsion elements in T. © 2008 American Mathematical Society Reverts to public domain 28 years from publication.
Breakthrough: Work by Contemporary Chinese Women Artists
Date: 2013-01-01
Creator: Sarah Montross, Shu-Chin Tsui
Access: Open access
- "This brochure accompanies an exhibition of the same name at the Bowdoin College Museum of Art, Brunswick, Maine, from September 27 through December 22, 2013"--Back of cover flap
Bowdoin College - Medical School of Maine Catalogue (1909-1910)
Date: 1910-01-01
Access: Open access
- Bowdoin College Bulletin no. 25
Bowdoin College Catalogue (1925-1926)
Date: 1926-01-01
Access: Open access
- Bowdoin College Bulletin no. 149
Bowdoin College Catalogue (1923-1924)
Date: 1924-01-01
Access: Open access
- Bowdoin College Bulletin no. 131
Bowdoin College Catalogue (1950-1951)
Date: 1951-01-01
Access: Open access
- Bowdoin College Bulletin no. 299
Bowdoin College Catalogue (1960-1961)
Date: 1961-01-01
Access: Open access
- Bowdoin College Bulletin no. 338
Bowdoin College Catalogue (1974-1975)
Date: 1975-01-01
Access: Open access
- Bowdoin College Bulletin no. 394
High Resolution Molecular Analysis of the Hedgehog Pathway in Tooth Development This record is embargoed.
- Embargo End Date: 2026-05-20
Date: 2021-01-01
Creator: Claire Christine Havig
Access: Embargoed
Bowdoin College Catalogue (1956-1957)
Date: 1957-01-01
Access: Open access
- Bowdoin College Bulletin no. 322
Bowdoin College Catalogue (1955-1956)
Date: 1956-01-01
Access: Open access
- Bowdoin College Bulletin no. 318
Motives Underlying China’s Foreign Aid Allocation Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2021-01-01
Creator: Cecilia Markmann
Access: Access restricted to the Bowdoin Community
Bowdoin College Catalogue (1971-1972)
Date: 1972-01-01
Access: Open access
- Bowdoin College Bulletin no. 382
It’s #PrisonAbolition Until the Bad Guys Show Up: Conflicting Discourses on Twitter about Carceral Networks in 2020
Date: 2021-01-01
Creator: Tam Phan
Access: Open access
- “Twitter Revolutions” in Iran, Tunisia, Egypt, and Moldova illustrate social media’s capacity to mobilize citizens in uprooting systems of injustice. As non-democratic regimes, these “Twitter Revolutions” offer insight into how Twitter’s microblogging, hashtags, and global user connections help broker relations between activists hoping to challenge the government. However, this thesis focuses on the democratic regime of the US and how Twitter plays a role in aiding the prison abolition movement in their effort to dismantle carceral networks that inflict racial and political violence on Black, Brown, Indigenous, and People of Color. The thesis outlines how, under the US’ classification as a democracy, the US utilizes infrastructural power to coerce American citizens into accepting carceral networks of violence as essential institutions to maintain civil society. The following sections explain the abolitionist movement’s history of attempting to dismantle the discrete formal and informal institutions of political violence, and includes the complicating development of liberal-progressive reformism that attempts to co-opt the goals of the abolition movement. The thesis focuses on the Twitter hashtag #PrisonAbolition in 2020 to explore how American Twitter users perceive the US carceral state and the prison abolition movement. The research concludes that #PrisonAbolition does not currently possess the capacity to evolve into the social mobilization seen in the “Twitter Revolutions” of non-democratic regimes because the US’ infrastructural power effectively engrained into the minds of Americans that prisons protect civil society. However, the tweets still show a promising development as American Twitter users become more engaged in abolitionist conversations.
Predicting Anionic Pharmaceutical Sorption to Soils Using Probe Compounds Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2022-01-01
Creator: Francesca Ann Cawley
Access: Access restricted to the Bowdoin Community
The Photocatalytic Degradation of Ibuprofen and Three Beta-Blockers using BiOCl: An Investigation into the Mechanisms Responsible for Photocatalytic Activity Access to this record is restricted to members of the Bowdoin community. Log in here to view.
- Restriction End Date: 2027-06-01
Date: 2022-01-01
Creator: Jeffrey Charles Price
Access: Access restricted to the Bowdoin Community
Urban Pastures: A Computational Approach to Identify the Barriers of Segregation
Date: 2022-01-01
Creator: Noah Gans
Access: Open access
- Urban Sociology is concerned with identifying the relationship between the built environment and the organization of residents. In recent years, computational methods have offered new techniques to measure segregation, including using road networks to measure marginalized communities' institutional and social isolation. This paper contributes to existing computational and urban inequality scholarship by exploring how the ease of mobility along city roads determines community barriers in Atlanta, GA. I use graph partitioning to separate Atlanta’s road network into isolated chunks of intersections and residential roads, which I call urban pastures. Urban pastures are social communities contained to residential road networks because movement outside of a pasture requires the need to use larger roads. Urban pastures fences citizens into homogenous communities. The urban pastures of atlanta have little (
Bowdoin College Catalogues, Course Guides, and Academic Handbooks
The Bowdoin College Catalogue is the official publication that describes entrance and degree requirements, course offerings, scholarships, student awards and prizes, and sanctioned student organizations. The Catalogue, which also lists the names of faculty and College officers and, until the late 1960s, the names and residences of students, is an essential resource for researching the curricular history of the College and biographies of Bowdoin students and faculty. For those years when the Medical School of Maine was administered by Bowdoin College (1820-1921), the Bowdoin College Catalogue was typically published jointly with that of the medical school.
In the 2010-2011 academic year, the Catalogue became primarily an online publication available via the College website; a pared down print version was also produced in parallel with the online Catalogue. From 2015-2019, the Academic Handbook: Policies and Procedures and Course Guide were published in place of the Catalogue. Starting in 2019, the College Catalogue and Academic Handbook was published online. The current version is available on the College website.
Metabolic Glycan Labeling in Bacteria Using Rare Azido L-sugars Access to this record is restricted to members of the Bowdoin community. Log in here to view.
- Restriction End Date: 2027-06-01
Date: 2022-01-01
Creator: Phuong Luong
Access: Access restricted to the Bowdoin Community
Re-envisioning the Tropics: Nick Joaquin's Philippine Gothic
Date: 2022-01-01
Creator: Ella Marie Jaman
Access: Open access
- This paper examines selected stories from Filipino author, Nick Joaquin, through a gothic lens. Drawing from recent development in Gothic studies, I work within a tropical gothic and postcolonial gothic framework to suggest a localized "Philippine gothic" represented within Nick Joaquin's work. Stories examined include the novel "The Woman Who Had Two Navels," as well as the short stories "Summer Solstice, Mass of St. Sylvestre," and "The Order of Melkizedek."
Role of the Dopamine Subtype 1 Receptor (D1R) Modulation of the Ih Current in Rhythmic Spinal Mammalian Motor Networks Access to this record is restricted to members of the Bowdoin community. Log in here to view.
- Restriction End Date: 2025-06-01
Date: 2022-01-01
Creator: Grace Soeun Lee
Access: Access restricted to the Bowdoin Community
Enhancer usage variation assessed via chromatin-conformation within and among three species of Drosophila This record is embargoed.
- Embargo End Date: 2027-05-19
Date: 2022-01-01
Creator: Maia B. Granoski
Access: Embargoed
The Current Hunt for Nitric Oxide's Effects on the Homarus americanus Cardiac Ganglion
Date: 2022-01-01
Creator: Joanna Lin
Access: Open access
- The crustacean heartbeat is produced and modulated by the cardiac ganglion (CG), a central pattern generator. In the American lobster, Homarus americanus, the CG consists of 4 small premotor cells (SCs) that electrically and chemically synapse onto 5 large motor cells (LCs). Rhythmic driver potentials in the SCs generate bursting in the LCs, which elicit downstream cardiac muscle contractions that are essential for physiological functions. Endogenous neuromodulators mediate changes in the CG to meet homeostatic demands caused by environmental stressors. Nitric oxide (NO), a gaseous neuromodulator, inhibits the lobster CG. Heart contractions release NO, which directly decreases the CG burst frequency and indirectly decreases the heartbeat amplitude, to mediate negative feedback. I investigated NO’s inhibitory effects on the CG to further understand the mechanisms underlying intrinsic feedback. Using extracellular recordings, I examined NO modulation of the SCs and LCs when coupled in the intact circuit and when firing independently in the ligatured preparation. Using two-electrode voltage clamp, I additionally analyzed the modulation of channel kinetics. Based on previous studies, I hypothesized that NO decreases the burst frequency of the LCs and SCs by modulating conductance properties of the voltage-gated A-type potassium current (IA). My data showed that NO decreased the burst frequency in the LCs and the burst duration in the SCs in a state-dependent manner. Furthermore, NO increased the IA inactivation time constant to decrease the LCs’ burst frequency. Thus, NO mediated inhibitory effects on cardiac output by differentially targeting both cell types and altering the IA current kinetics.