Showing 161 - 170 of 583 Items

Mechanisms underlying variable responses to the neuropeptide C-type allatostatin (AST-C) across isoforms and among individuals in the American lobster, Homarus americanus

Date: 2020-01-01

Creator: Audrey J. Muscato

Access: Open access

Central pattern generators (CPGs) produce patterned outputs independent of sensory input. The cardiac neuromuscular system of the American lobster (Homarus americanus) is driven by a CPG called the cardiac ganglion (CG), which is composed of nine neurons, making it a model system of study. Modulation of CPGs allows for functional flexibility. One neuropeptide family that modulates the CG is C-type allatostatin (AST-C I-III). Previous research has shown variation in the responses of the CG across the three isoforms and among individuals. First, we investigated why AST-C I and III elicit responses that are more similar to each other than they are to the responses elicited by AST-C II. We hypothesized that an amino acid difference in the conserved sequence was responsible for the observed variation in responses. We synthesized isoforms of AST-C that replaced the endogenous amino acid and recorded responses to these isoforms. The identity of one particular amino acid in the conserved sequence seems to be responsible for variations in responses in frequency. Next, we focused on variation among individuals in their responses to AST-C I and III. We hypothesized that the mechanism behind this individual variation is differential expression of AST-C receptors and/or their downstream targets. We recorded physiological responses of the cardiac system to AST-C and then sequenced CG RNA from the same lobsters. Differential expression of one of the AST-C receptors and a number of downstream factors is correlated with physiological response. These findings inspire further experimentation investigating molt cycle as the underlying cause.


Alongside Despair: Signs of Life on the River des Peres

Date: 2020-01-01

Creator: Marina Henke

Access: Open access

This River des Peres is a partially enclosed river which runs through St. Louis, Missouri. Used since prior to the city’s founding, the des Peres has gone through two considerable engineering projects: one in 1901 in light of the World’s Fair, and one in 1923, which encapsulated more than half of the river and placed nearly five miles of it underground. Presently, the des Peres constitutes the backbone of the sanitary and sewer system of St. Louis city and county. Ultimately, the river offers a broad meditation on what it means to live around and in a “natural” waterway that is simultaneously not natural at all. Themes of St. Louis are equally reflected in the river: of environmental racism, of Midwestern decline, and of urban decay and renewal. Additionally, those who interact with the river prove a broad cast of characters. Through using a selection of interviews with locals, alongside an engagement with the work of contemporary poet Donald Finkel, this piece of creative nonfiction explores the multiplicity, and ultimately the value, of distorted natural spaces.


Miniature of Non-genomic effects of steroids on teleost fish olfaction: behavioral and anatomical approaches
Non-genomic effects of steroids on teleost fish olfaction: behavioral and anatomical approaches
Access to this record is restricted to members of the Bowdoin community. Log in here to view.

      Date: 2020-01-01

      Creator: Leah B Kratochvil

      Access: Access restricted to the Bowdoin Community



        Miniature of Wnt Signaling is Dispensable to Formation of the First Tooth in <i>D. Rerio</i>
        Wnt Signaling is Dispensable to Formation of the First Tooth in D. Rerio
        This record is embargoed.
          • Embargo End Date: 2025-05-14

          Date: 2020-01-01

          Creator: Zachary C. LeBlanc

          Access: Embargoed



            Miniature of Tapping at the Windows: A Collection
            Tapping at the Windows: A Collection
            This record is embargoed.
              • Embargo End Date: 2025-05-14

              Date: 2020-01-01

              Creator: Samuel Milligan

              Access: Embargoed



                Performing Sor Juana: Reimagining a Mexican Literary Figure in the 21st Century

                Date: 2020-01-01

                Creator: Uriel López-Serrano

                Access: Open access

                Sor Juana Inés de la Cruz (c. 1648-1695) was a Mexican nun, poet, playwright, and scholar from the colonial era. She has become an icon for various global, social, and political movements. This project looks at four dramatic works created by Sorjuanistas who reimagine Sor Juana’s story for contemporary audiences living in the United States. The works included in this essay are Estela Portillo-Trambley’s Sor Juana (1986), Karen Zacarías’s The Sins of Sor Juana (2001), and Alicia Gaspar de Alba’s “Interview with Sor Juana Inés de la Cruz” (1998/2014) and her newest work, Juana: An Opera in Two Acts (2019), libretto by Carla Lucero. In addition to reimagining Sor Juana’s story, these dramatic works expose the sexism, racism, and xenophobia perpetuated by U.S institutions of power that discriminate against Latin@ and Chican@ individuals. By shedding light on the social injustices that existed during the colonial era, an embodied Sor Juana teaches audiences how to resist and mobilize against such oppressive powers. Sor Juana’s narrative on stage is necessary because she is a role model for Latin@s/Chican@s. Sorjuanistas remind us that the body can be used to retell the narratives of the silenced individuals who are victims of oppression. By developing heritage performances, Sorjuanistas challenge histories that silence and overlook social injustices. Witnessing Sor Juana on stage triggers emotional responses to the past which allow historical actors to obtain intellectual, emotional, and political agency in an effort to affirm and remember particular contemporary and future commitments to fighting social injustices.


                Miniature of An Analysis of Hezbollah’s Media Platforms, Focusing on Themes, Narratives and Strategy
                An Analysis of Hezbollah’s Media Platforms, Focusing on Themes, Narratives and Strategy
                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: Nichole Irving

                  Access: Access restricted to the Bowdoin Community



                    Miniature of Noninvasive Memory Modulation Via Targeted Theta TACS Entrainment of the Frontoparietal Network
                    Noninvasive Memory Modulation Via Targeted Theta TACS Entrainment of the Frontoparietal Network
                    Access to this record is restricted to members of the Bowdoin community. Log in here to view.
                    • Restriction End Date: 2026-06-01

                      Date: 2021-01-01

                      Creator: Brandon S Lee

                      Access: Access restricted to the Bowdoin Community



                        Down in arms: Marine climate stress inhibits growth and calcification of regenerating Asterias forbesi (Echinodermata: Asteroidea) arms

                        Date: 2021-01-01

                        Creator: Hannah L. Randazzo

                        Access: Open access

                        Anthropogenic CO2 is changing the pCO2, temperature, and carbonate chemistry of seawater. These processes are termed ocean acidification (OA) and ocean warming. Previous studies suggest two opposing hypotheses for the way in which marine climate stress will influence echinoderm calcification, metabolic efficiency, and reproduction: either an additive or synergistic effect. Sea stars have a regenerative capacity, which may be particularly affected while rebuilding calcium carbonate arm structures, leading to changes in arm growth and calcification. In this study, Asterias forbesi were exposed to ocean water of either ambient, high temperature, high pCO2, or high temperature and high pCO2 for 60 days, and the regeneration length of the amputated arm was measured weekly. Ocean acidification conditions (pCO2 ~1180 μatm) had a negative impact on regenerated arm length, and an increase in temperature of +4°C above ambient conditions (Fall, Southern Gulf of Maine) had a positive effect on regenerated arm length, but the additive effects of these two factors resulted in smaller regenerated arms compared to ambient conditions. Sea stars regenerating under high pCO2 exhibited a lower proportion of calcified mass, which could be the result of a more energetically demanding calcification process associated with marine climate stress. These results indicate that A. forbesi calcification is sensitive to increasing pCO2, and that climate change will have an overall net negative effect on sea star arm regeneration. Such effects could translate into lower predation rates by a key consumer in the temperate rocky intertidal of North America.


                        Miniature of Identification and characterization of genes involved in <i>Helicobacter pylori</i> lipopolysaccharide and glycoprotein biosynthesis
                        Identification and characterization of genes involved in Helicobacter pylori lipopolysaccharide and glycoprotein biosynthesis
                        Access to this record is restricted to members of the Bowdoin community. Log in here to view.

                            Date: 2021-01-01

                            Creator: Andrew James Mulholland

                            Access: Access restricted to the Bowdoin Community