Showing 1641 - 1650 of 2125 Items
Genetic Analysis of Cellular Adhesion in Arabidopsis thaliana
Date: 2021-01-01
Creator: Andrew Close Bolender
Access: Open access
- Plant cell adhesion is mediated by the extracellular matrix (ECM) or cell wall and plays an important role in plant morphogenesis and development. The amount, modification, and cleavage of pectin in the cell wall are major contributors to the adhesive properties of the ECM. To gain a more complete picture of plant cell adhesion processes, Arabidopsis thaliana seedlings were previously mutagenized and screened for hypocotyl adhesion defects. Genomic sequencing of one plant exhibiting an adhesion defect, isolate 242, showed that two mutations, one in cellulose synthase (CesA1) and another in a sugar transporter, are candidates for the causative mutation. This thesis reports that CesA1 is necessary for proper plant cell adhesion, while the sugar transporter encoded at At4g32390 is not. Dark grown seedlings homozygous for mutations in CesA1 stain in ruthenium red, indicating atypical adhesion, while those homozygous for null mutations in At4g32390 do not. Previous study of another adhesion mutant revealed ELMO1, a Golgi protein necessary for plant cell adhesion, and four additional homologs ELMO2-5 in the A. thaliana genome. Two of these homologs, ELMO2 and ELMO3, fused to GFP, colocalized with mCherry-MEM1 markers in the Golgi, but not mCherry-NLM12 ER markers, indicating that ELMO2 and ELMO3 are also Golgi proteins.
Word Embedding Driven Concept Detection in Philosophical Corpora
Date: 2020-01-01
Creator: Dylan Hayton-Ruffner
Access: Open access
- During the course of research, scholars often explore large textual databases for segments of text relevant to their conceptual analyses. This study proposes, develops and evaluates two algorithms for automated concept detection in theoretical corpora: ACS and WMD retrieval. Both novel algorithms are compared to key word retrieval, using a test set from the Digital Ricoeur corpus tagged by scholarly experts. WMD retrieval outperforms key word search on the concept detection task. Thus, WMD retrieval is a promising tool for concept detection and information retrieval systems focused on theoretical corpora.
"I Deny Your Authority to Try My Conscience:" Conscription and Conscientious Objectors In Britain During the Great War
Date: 2019-05-01
Creator: Albert William Wetter
Access: Open access
- During the Great War, the Military Service Act was introduced on January 27, 1916 and redefined British citizenship. Moreover, some men objected to the state’s military service mandate, adamant that compliance violated their conscience. This thesis investigates how the introduction of conscription reshaped British society, dismantled the “sacred principle” of volunteerism, and replaced it with conscription, resulting in political and popular debates, which altered the individual’s relationship with the state. British society transformed from a polity defined by the tenets of Liberalism and a free-will social contract to a society where citizenship was correlated to duty to the state. Building off Lois Bibbings’ research on conscientious objectors, this thesis nuances the analysis with the case studies of David Blelloch and Norman Gaudie. Framed by two theories—Benedict Anderson’s imagined community and Barbara Rosenwein’s emotional community—these case studies demonstrate how conscientious objectors exposed the incongruence of the British imagined and emotional community, and the redefinition of citizenship. By weaving these theories into the British Great War tapestry, this thesis contends that the British nation was imagined differently before the war than it was after the war because of the introduction of conscription. Drawing from parliamentary debate transcripts, newspaper articles, and archival material from the Imperial War Museum in London, and the Liddle Personal Collection at the University of Leeds, Blelloch’s and Gaudie’s respective case studies ultimately bait the question: “What does it mean to be British?”
Interview with Noma Petroff by Marina Henke
Date: 2019-11-09
Creator: Noma Petroff
Access: Open access
- Noma Petroff shares her time working at Bowdoin, as secretary of the Senior Center (1975-1979), secretary of Afro-American Studies (1979-1985), secretary Women’s Studies (1990), and academic coordinator of Theater and Dance (1991-2016). She discusses her path to Bowdoin, and specifically her path to working in Russworm, coming from working at the University of Michigan in Ann Arbor and even leaving Bowdoin for several years to work on a Pennsylvanian farm. She recounts how she tried to serve as an ally to students of color on campus. Petroff describes the dynamic environment of Russworm during the early eighties, including the work she put into starting the center’s library. She shares stories from various work-study students who worked with her, including two students who fell in love after separately working under her. Petroff describes the transformations to the African American Studies department over her many years at the college, including highlights of working under both Randy Stakeman and Lynn Bolles.
Interview with George Khaldun (Class of 1973) by Marcus Williams
Date: 2019-11-09
Creator: George Khaldun
Access: Open access
- George Khaldun ’73 came to Bowdoin from New York at the suggestion of a mentor, the director of a library where Kahldun had worked part-time in high school. He shares that he was at first apprehensive of moving to Maine but decided to apply since it would provide a change of pace from the inner city. He discusses his political affiliation as a Black Panther and the comradery he felt in finding others at Bowdoin who shared his revolutionary beliefs. Kahldun found these men in the Afro-American Society, where he could connect with black people from across the country. He says this community helped hone his political beliefs but also adjust to the rigors of Bowdoin academics. Kahldun admits to struggling during his first year, after finding support in the Society, he was able to succeed in school.
Interview with Steve London (Class of 1964) by Marcus Williams
Date: 2019-11-09
Creator: Steve London
Access: Open access
- Steve London '64 describes his family's long connection to Bowdoin, spanning three generations. He shares his father's experience at the College as a Jewish student in the 1930s who found most allegiance with the several black students on campus at the time. Speaking of his own time as a student, London describes how the civil rights movement greatly influenced his experience as an undergraduate. His time at Bowdoin and engagement with racial activism led him to later work with the Southern Christian Leadership Conference for two years shortly after graduating from Bowdoin. London outlines the ways that activism and understanding the role of identity and inequity were a central part to his time at the College, and his path afterwards.
Interview with Mark Richter (Class of 2014) by Marina Henke
Date: 2019-11-10
Creator: Mark Richter
Access: Open access
- Mark Richter ('14) shares his experience as an Africana Studies student who grew up in Brunswick, Maine. He tells of his path to the Africana Studies department, as largely influenced by his classes with Professor Brian Purnell, including his course on the popular television show, 'The Wire.’ Richter describes how his academic work at Bowdoin provided him with a certain language to explore and discuss topics that he had not had the verbage for before. He recounts certain classes in the department which allowed for conversations surrounding race and identity that may not have happened normally on campus. Finally, Richter offers insight into how his major at Bowdoin has prepared him for work at the Harvard Graduate School of Education, and given him tools as a white male to understand privilege and inequity.
GEM-PSO: Particle Swarm Optimization Guided by Enhanced Memory
Date: 2019-05-01
Creator: Kevin Fakai Chen
Access: Open access
- Particle Swarm Optimization (PSO) is a widely-used nature-inspired optimization technique in which a swarm of virtual particles work together with limited communication to find a global minimum or optimum. PSO has has been successfully applied to a wide variety of practical problems, such as optimization in engineering fields, hybridization with other nature-inspired algorithms, or even general optimization problems. However, PSO suffers from a phenomenon known as premature convergence, in which the algorithm's particles all converge on a local optimum instead of the global optimum, and cannot improve their solution any further. We seek to improve upon the standard Particle Swarm PSO algorithm by fixing this premature convergence behavior. We do so by storing and exploiting increased information in the form of past bests, which we deem enhanced memory. We introduce three types of modifications to each new algorithm (which we call a GEM-PSO: Particle Swarm Optimization, Guided by Enhanced Memory, because our modifications all deal with enhancing the memory of each particle). These are procedures for saving a found best, for removing a best from memory when a new one is to be added, and for selecting one (or more) bests to be used from those saved in memory. By using different combinations of these modifications, we can create many different variants of GEM-PSO that have a wide variety of behaviors and qualities. We analyze the performance of GEM-PSO, discuss the impact of PSO's parameters on the algorithms' performances, isolate different modifications in order to closely study their impact on the performance of any given GEM-PSO variant, and finally look at how multiple modifications perform. Finally, we draw conclusions about the efficacy and potential of GEM-PSO variants, and provide ideas for further exploration in this area of study. Many GEM-PSO variants are able to consistently outperform standard PSO on specific functions, and GEM-PSO variants can be shown to be promising, with both general and specific use cases.
Placemaking and Community-Building among Lesbian, Bisexual, and Queer (LBQ) Women and Non-Binary People during the Covid-19 Pandemic
Date: 2021-01-01
Creator: Gabby Unipan
Access: Open access
- This paper draws on data collected through in-depth interviews with multi-generational participants recruited from various online sites to explore the place-making strategies among lesbian, bisexual, and queer (LBQ) women and trans- and gender-non-conforming people (tgncp) during the Covid-19 pandemic. Historically denied public space, placemaking in immaterial space (i.e., digital spaces) has been essential to the production and maintenance of communities for LBQ women and tgncp. Because these populations rely on non-traditional placemaking strategies that are not always instantiated in material space, sociologists often overlook their efforts to create place for themselves. This paper corrects this omission by exploring how communities create place through the deployment of subcultural capital onto immaterial space. Introducing four main strategies of community placemaking, material-constant communities, material-transient communities, immaterial-constant communities, and immaterial-transient communities, this article expands sociological conceptions of space to accommodate the placemaking strategies of marginalized communities who might lack the economic and political resources to foster communities in material spaces. Beyond the investigation of lesbian-queer placemaking, this research contributes to the growing sociological literature exploring the multifaceted, fluid, contested, and ephemeral nature of place and placemaking in the context of increasing Internet use.
Promises Unfulfilled: Integration and Segregation in Metropolitan Philadelphia Public Schools, 1954-2009
Date: 2021-01-01
Creator: Nina Nayiri McKay
Access: Open access
- Even though Brown v. Board of Education outlawed segregation in public schools in 1954, many American children still attend schools that are racially and, increasingly, socioeconomically segregated. Philadelphia, a northern city that did not have an explicit policy of segregating children on the basis of race when Brown was decided, nevertheless still has entrenched residential segregation that replicates in public schools. The metropolitan area became a segregated space in the years around World War II, when housing discrimination, employment discrimination, lending discrimination, suburbanization, and urban renewal started the years-long trajectory of growing white suburbs surrounding an increasingly non-white and under-resourced urban core. These patterns had profound implications for school segregation, which city organizers began trying to fight shortly after Brown v. Board. However, the first court case to take on segregation in Philadelphia schools—Chisholm v. The Board of Education—was largely unsuccessful, with overburdened NAACP and ally lawyers struggling to meet the judge’s expectations of concrete proof of an intent to segregate on the School District of Philadelphia’s part. In the early 1960s, though, the state’s Human Relations Commission obtained a legislative mandate to take on school desegregation. It won its first integration victory in the Pennsylvania port city of Chester before moving to Philadelphia, where it pushed for school integration from 1968 to 2009. The city’s political and ideological battles over those decades reflect national trends around the rise of conservatism and neoliberalism in suburban politics and school reform, limiting the possibilities for change.