Showing 1611 - 1620 of 2039 Items
James Bowdoin III: Pursuing Style in the Age of Independence
Date: 2008-01-01
Creator: Vernon Scott
Access: Open access
- Catalog of an exhibition held at the Bowdoin College Museum of Art from Sept. 9, 2008, through June 7, 2009. Essay by V. Scott Dimond
Landscape in Maine 1820-1970: A Sesquicentennial Exhibition
Date: 1970-01-01
Creator: James Morton
Access: Open access
- Catalog of an exhibition held at the Colby College Art Museum, April 4-May 10; the Bowdoin College Museum of Art, May 21-June 28; and the Carnegie Gallery, University of Maine, Orono, July 8-August 30. Sponsored by the Maine Federation of Women's Clubs.
Interview with Emma Johnson (Class of 2014), Chelsea Shaffer (Class of 2014), and Hannah Tennent (Class of 2014) with Emma Kellogg
Date: 2019-06-01
Creator: Emma Johnson
Chelsea Shaffer
Hannah Tennent
Access: Open access
- Emma Johnson (Class of 2014), Chelsea Shaffer (Class of 2014), and Hannah Tennent (Class of 2014) describe their memories of meeting one another as first year roommates in Coleman Hall. Johnson, Shaffer, and Tennent discuss their on-campus jobs as well as various extracurricular activities, including the Generous Enthusiasts, the Judicial Board, and the Outing Club, respectively. The three reminisce about some of their most impactful courses in departments like Anthropology, Earth and Oceanographic Science, and Visual Arts. They reflect on cultural conversations happening on campus during their tenure and mention hazing, the Social House system, and discussions of diversity. Additionally, the group comments on the life lessons they learned at Bowdoin and what the College means to them as alumni.
The Bowdoin Orient
- The Bowdoin Orient, Bowdoin’s student newspaper, began publication in 1871 and is the nation’s oldest continuously published college weekly. It provides news and information relevant to the Bowdoin community, especially concerning student social life, and maintains a tradition of editorial independence from the College and its administration.
The effects of nitric oxide on the modulation of the cardiac system of the American lobster, Homarus americanus, via a peptide (GYSDRNLRFamide)
Date: 2014-08-01
Creator: Sophie Janes
Access: Open access
- The central pattern generator (CPG) is a neural network that controls the rhythmic patterned outputs, which generate locomotion as needed. The lobster provides a good model to study CPGs because it has a relatively simple CPG. The lobster CPG, or cardiac ganglion accommodates for a range of activities and changes in the environment (Cooke, 2002).The small lobster CG is made up of nine neurons that control the neurogenic heart. The lobster CG is located on the inner dorsal wall of the heart and forms long neurites that branch onto the heart muscle. The CG, through an intrinsic mechanism, generates patterned and rhythmic bursts to the heart (Cooke 2002).The H. americanus CG sends information to the heart muscle to regulate the heart beat. The patterned bursts from the CG need to be adjusted in response to changing demands, for example, activity level or blood volume. Two general mechanisms, intrinsic feedback and extrinsic neuromodulation, have been identified to facilitate this adjustment. Through an intrinsic feedback mechanism, the muscle sends information back to the CG via a positive pathway and a negative pathway. In the positive pathway, stretch-sensitive dendrites of cardiac neurons increase the frequency of heart contractions when stretched (Cooke 2002). In the negative pathway, nitric oxide (NO), produced by the cardiac muscle, slows the frequency (Mahadevan et al. 2004). The interplay between the negative and positive feedback pathways regulates the output of the CG. An extrinsic mechanism has also been identified to regulate the CG output. Chemical neuromodulators that are released either locally or as hormones signal to the heart or CG to modulate ganglion activity. The intrinsic and extrinsic mechanisms affect the contraction amplitude and frequency of the heart.Within this simple invertebrate organism, a complex layering of control exists. Studies of the effects of various extrinsic modulators suggest that these modulators may alter how the feedback pathways operate. I examined what effect the neuromodulator GYSDRNLRFamide (GYS), a peptide found in the lobster nervous system, has on the balance between the positive and negative pathways (Ma et al., 2008). Recent experiments have demonstrated that when GYS was applied at high concentrations in the whole heart, the frequency decreased. This suggests that GYS may play a role in the intrinsic feedback pathways, and likely enhances the negative pathway.I looked at if nitric oxide altered the modulation of the heartbeat frequency when enhanced by the extrinsic modulator, GYS. Based on previous experiments, I hypothesized that GYS allows the NO, or negative pathway to predominate. In order to test my hypothesis, I examined the effects of GYS when I removed nitric oxide, which allows the negative pathway to exist. I compared the characteristics of the heartbeat when saline was run through the heart to when GYS was run through the heart. I also compared the characteristics of the heartbeat when the NO inhibitor, L-NA, was applied to when GYS was applied in the presence of L-NA. I finally compared the changes in frequency between these two comparisons. I found a significant difference between the change in frequency of the heart perfused with GYS in saline as opposed to perfused with GYS in L-NA. GYS had a greater negative effect without L-NA. These results demonstrate that NO is likely the cause of the observed decrease in frequency. Final Report of research funded by the Doherty Coastal Studies Research Fellowship.