Showing 4501 - 4550 of 5840 Items
Bowdoin College Catalogue (1969-1970)
Date: 1970-01-01
Access: Open access
- Bowdoin College Bulletin no. 374
Bowdoin College Catalogue (1965-1966)
Date: 1966-01-01
Access: Open access
- Bowdoin College Bulletin no. 358
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.
Bowdoin College Catalogue (1913-1914)
Date: 1914-01-01
Access: Open access
- Bowdoin College Bulletin no. 50
Application of the Landau-Zener Model and Fermi's Golden Rule to Estimate Triplet Quantum Yield for Organic Molecules Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2014-05-01
Creator: Nathan D Ricke
Access: Access restricted to the Bowdoin Community
Nontranscribed spacer sequences promote in vitro transcription of Drosophila ribosomal DNA
Date: 1982-11-11
Creator: Bruce D. Kohorn, Peter M.m. Rae
Access: Open access
- Tandem repeats of ribosomal RNA transcription units in Drosophila melanogaster are separated by a nontranscribed spacer that is comprised in part of serial repeats of a 0.24 kb sequence. DNA sequence analysis shows that such repeats are imperfect copies of a region that includes the site of in vivo rRNA transcription initiation (ca. -240 to +30). Subclones of the rDNA spacer that are copies of the sequence extending from -34 through the initiation site support detectable in vitro transcription in a mixture involving a Drosophila cell-free extract, but accurate in vitro transcription is considerably enhanced when a nontranscribed spacer template includes a copy of the sequence extending upstream of -34. From a comparison of the sequence and transcription template-effectiveness of various rDNA subclones, we infer that a major promoter of RNA polymerase I activity lies between -150 and -30 in the rDNA nontranscribed spacer. The nontranscribed spacer copies of the initiation region are less effective templates for transcription than is the region of in vivo initiation and there are differences between spacer repeates and the authentic sequence downstream of -240 that may account for this. © 1982 IRL Press Limited.
Balancing Survival and Extinction in Nonautonomous Competitive Lotka-Volterra Systems
Date: 1995-06-01
Creator: F. Montes de Oca, M. L. Zeeman
Access: Open access
- We generalise and unify some recent results about extinction in nth-order nonautonomous competitive Lotka-Volterra systems. For each r ≤ n, we show that if the coefficients are continuous, bounded by strictly positive constants, and satisfy certain inequalities, then any solution with strictly positive initial values has the property that n - r of its components vanish, whilst the remaining r components asymptotically approach a canonical solution of an r-dimensional restricted system. In other words, r of the species being modeled survive whilst the remaining n - r are driven to extinction. © 1995 Academic Press, Inc.
Bowdoin College - Medical School of Maine Catalogue (1915-1916)
Date: 1916-01-01
Access: Open access
- Bowdoin College Bulletin no. 61
Rehab, Restitution, or Reform? Drug Policy, Race, and Swing Voters in Ohio Politics, 1983-2015 Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2020-01-01
Creator: Grace Louise Cawdrey
Access: Access restricted to the Bowdoin Community
Metabolic Inhibitors Induce Species-Specific Defects in Bacterial Glycosylation Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2020-01-01
Creator: Ilana R. Olin
Access: Access restricted to the Bowdoin Community
Free limits of Thompson's group F
Date: 2011-12-01
Creator: Azer Akhmedov, Melanie Stein, Jennifer Taback
Access: Open access
- We produce a sequence of markings Sk of Thompson's group F within the space Gn of all marked n-generator groups so that the sequence (F, Sk) converges to the free group on n generators, for n ≥ 3. In addition, we give presentations for the limits of some other natural (convergent) sequences of markings to consider on F within G3, including (F, {x0, x1, xn}) and (F, {x0, x1, x0n}) © 2011 Springer Science+Business Media B.V.
Examination of tooth-specific cis-regulation of the dlx2b gene during zebrafish development This record is embargoed.
- Embargo End Date: 2025-05-14
Date: 2020-01-01
Creator: Yujin Moon
Access: Embargoed
Dead end words in lamplighter groups and other wreath products
Date: 2005-09-22
Creator: Sean Cleary, Jennifer Taback
Access: Open access
- We explore the geometry of the Cayley graphs of the lamplighter groups and a wide range of wreath products. We show that these groups have dead end elements of arbitrary depth with respect to their natural generating sets. An element w in a group G with finite generating set X is a dead end element if no geodesic ray from the identity to w in the Cayley graph Γ(G, X) can be extended past w. Additionally, we describe some non-convex behaviour of paths between elements in these Cayley graphs and seesaw words, which are potential obstructions to these graphs satisfying the k-fellow traveller property. © The Author 2005. Published by Oxford University Press. All rights reserved.
Pectin activation of MAP kinase and gene expression is WAK2 dependent
Date: 2009-12-01
Creator: Bruce D. Kohorn, Susan Johansen, Akira Shishido, Tanya Todorova, Rhysly, Martinez, Elita Defeo, Pablo Obregon
Access: Open access
- The angiosperm extracellular matrix, or cell wall, is composed of a complex array of cellulose, hemicelluose, pectins and proteins, the modification and regulated synthesis of which are essential for cell growth and division. The wall associated kinases (WAKs) are receptor-like proteins that have an extracellular domain that bind pectins, the more flexible portion of the extracellular matrix, and are required for cell expansion as they have a role in regulating cellular solute concentrations. We show here that both recombinant WAK1 and WAK2 bind pectin in vitro. In protoplasts pectins activate, in a WAK2-dependent fashion, the transcription of vacuolar invertase, and a wak2 mutant alters the normal pectin regulation of mitogen-activated protein kinases. Microarray analysis shows that WAK2 is required for the pectin activation of numerous genes in protoplasts, many of which are involved in cell wall biogenesis. Thus, WAK2 plays a major role in signaling a diverse array of cellular events in response to pectin in the extracellular matrix. © 2009 Blackwell Publishing Ltd.
Photographs: John McKee
Date: 1973-01-01
Access: Open access
- "Catalogue published in conjunction with an exhibition held at the Bowdoin College Museum of Art, April 6-May 27, 1984"--T.p. verso
Winslows: Pilgrims, Patrons, and Portraits
Date: 1974-01-01
Access: Open access
- Catalogue from a joint exhibition at Bowdoin College Museum of Art and the Museum of Fine Arts, Boston. Includes biographical references.
All Maine Biennial '79
Date: 1979-01-01
Access: Open access
- "Exhibition dates: July 27-September 16, 1979." "Supported by the Maine State Commission on the Arts and the Humanities."
Replacement of histidines of light harvesting chlorophyll a/b binding protein II disrupts chlorophyll-Protein complex assembly
Date: 1990-01-01
Creator: Bruce D. Kohorn
Access: Open access
- Eukaryotic light harvesting proteins (LHCPs) bind pigments and assemble into complexes (LHCs) that channel light energy into photosynthetic reaction centers. The structures of several prokaryotic LHCPs are known and histidines are important for the binding of the associated pigments. It has been difficult to predict how the eukaryotic LHCPs associate with pigments as the structure of the major LHCP of photosystem II is not yet known. While each LHCPII binds approximately 13 chlorophylls the protein contains only three histidines, one in each putative transmembrane helix. Experiments that use isolated pea (Pisum sativum L.) chloroplasts and mutant LHCPII synthesized in vitro show that the substitution of either an alanine or an arginine for each histidine residue inhibits some aspect of LHCII assembly. The histidine of the first membrane helix, but not the second or third, may be involved in the transport across the chloroplast envelope. No histidine alone is essential for the insertion of LHCP into thylakoid membranes, yet arginine substitutions are more inhibitory than those of alanine. The histidine replacements have their most pronounced effect on the assembly of LHCP into LHCII.
Calculating the Local Biotic Exchange Ratio of O2 and CO2 at Harvard Forest: Using Flux Measurements to Improve Past Estimates 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: Diana Katalina Grandas
Access: Access restricted to the Bowdoin Community
Breathers and other time-periodic solutions in an array of cantilevers decorated with magnetsy
Date: 2019-01-01
Creator: Christopher Chong, Andre Foehr, Efstathios G. Charalampidis, Panayotis G. Kevrekidis, Chiara, Daraio
Access: Open access
- In this article, the existence, stability and bifurcation structure of time-periodic solutions (including ones that also have the property of spatial localization, i.e., breathers) are studied in an array of cantilevers that have magnetic tips. The repelling magnetic tips are responsible for the intersite nonlinearity of the system, whereas the cantilevers are responsible for the onsite (potentially nonlinear) force. The relevant model is of the mixed Fermi-Pasta-Ulam-Tsingou and Klein-Gordon type with both damping and driving. In the case of base excitation, we provide experimental results to validate the model. In particular, we identify regions of bistability in the model and in the experiment, which agree with minimal tuning of the system parameters. We carry out additional numerical explorations in order to contrast the base excitation problem with the boundary excitation problem and the problem with a single mass defect. We find that the base excitation problem is more stable than the boundary excitation problem and that breathers are possible in the defect system. The effect of an onsite nonlinearity is also considered, where it is shown that bistability is possible for both softening and hardening cubic nonlinearities.
Democracy Promotion in U.S. Counterinsurgency: Tracing Post-War Security Sector Reconstruction in El Salvador and Iraq
Date: 2020-01-01
Creator: Emma Redington Lawry
Access: Open access
- Throughout the 21st century, certain facets of the democratic peace theory have informed American foreign policy, as policymakers credit democracy promotion with long-term stability and peace. In contrast, many political scientists have documented the often destabilizing and violent effects of democratization, particularly in underdeveloped states. How can we reconcile these tensions, and in what ways do they affect American foreign policy abroad? Under the lens of just war theory, or the doctrine of military ethics detailing the conditions under which it is morally acceptable to go to war, wage war and restore peace after war, this paper seeks to examine security sector reconstruction in post-counterinsurgency eras. In doing so, my analysis documents the effects of electoral processes on security and underscores the many difficulties of post-war rebuilding processes. In understanding these difficulties, I attempt to extract crucial lessons from the “best case” scenario of El Salvador and the “worst case” scenario of Iraq, both of which illuminate the fundamental tension between democratization and stability.
Bowdoin College Catalogue (1907-1908)
Date: 1908-01-01
Access: Open access
- Bowdoin College Bulletin no. 14
Bounding right-arm rotation distances
Date: 2007-03-01
Creator: Sean Cleary, Jennifer Taback
Access: Open access
- Rotation distance measures the difference in shape between binary trees of the same size by counting the minimum number of rotations needed to transform one tree to the other. We describe several types of rotation distance where restrictions are put on the locations where rotations are permitted, and provide upper bounds on distances between trees with a fixed number of nodes with respect to several families of these restrictions. These bounds are sharp in a certain asymptotic sense and are obtained by relating each restricted rotation distance to the word length of elements of Thompson's group F with respect to different generating sets, including both finite and infinite generating sets. © World Scientific Publishing Company.
A Gift Of Knowing: The Art Of Dorothea Rockburne
Date: 2015-01-01
Access: Open access
- Published for the exhibition A Gift of Knowing: The Art of Dorothea Rockburne at the Bowdoin College Museum of Art from March 14 through April 26, 2015, supported by the Elizabeth B. G. Hamlin Fund and the Shapell Family Art Fund. Design by Wilcox Design, Cambridge, Massachusetts Copyright© 2015 Bowdoin College
Bowdoin College Catalogue (1919-1920)
Date: 1920-01-01
Access: Open access
- Bowdoin College Bulletin no. 98
Directed interactions during episodic memory 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: Rhianna J Patel
Access: Access restricted to the Bowdoin Community
Simplified insertion of transgenes onto balancer chromosomes via recombinase-mediated cassette exchange
Date: 2012-05-01
Creator: Florence F. Sun, Justine E. Johnson, Martin P. Zeidler, Jack R. Bateman
Access: Open access
- Balancer chromosomes are critical tools for Drosophila genetics. Many useful transgenes are inserted onto balancers using a random and inefficient process. Here we describe balancer chromosomes that can be directly targeted with transgenes of interest via recombinase-mediated cassette exchange (RMCE). ©2012 Sun et al.
An Ode to the Birth Justice Movement Birthing, Battling, Being: Black Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2020-01-01
Creator: Eskedar Girmash
Access: Access restricted to the Bowdoin Community
Investigating enhancer regulation through chromatin conformation in Drosophila Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2020-01-01
Creator: Hannah D. Konkel
Access: Access restricted to the Bowdoin Community
Interview with Paul Brountas (1) by Mike Hastings
Date: 2009-02-20
Creator: Paul P. Brountas
Access: Audio recording permanently restricted
- Biographical NotePaul Peter Brountas was born on March 19, 1932, in Bangor, Maine. He and George Mitchell were classmates at Bowdoin College, where he was graduated with a bachelor’s degree in 1954; he took bachelor’s and master’s degrees from the University of Oxford in 1956 and his law degree from Harvard Law School in 1960. That same year, he joined Hale and Dorr, the predecessor of WilmerHale. He became a partner in 1968 and served as senior counsel to the firm from 2003 until his retirement in 2005. In 1987 and 1988, he served as national chairman of the Committee to Elect Michael S. Dukakis President of the United States, and in 1968 he served as a campaign aide to Senator Edmund Muskie during the Humphrey-Muskie presidential campaign. SummaryInterview includes discussion of: growing up in Bangor, Maine, influenced by Greek ethnicity; attending Bowdoin College in the early 1950s. Remainder of interview permanently restricted.
Maximal stomatal conductance to water and plasticity in stomatal traits differ between native and invasive introduced lineages of Phragmites australis in North America
Date: 2016-01-27
Creator: V. Douhovnikoff, S. H. Taylor, E. L.G. Hazelton, C. M. Smith, J., O'Brien
Access: Open access
- The fitness costs of reproduction by clonal growth can include a limited ability to adapt to environmental and temporal heterogeneity. Paradoxically, some facultatively clonal species are not only able to survive, but colonize, thrive and expand in heterogeneous environments. This is likely due to the capacity for acclimation (sensu stricto) that compensates for the fitness costs and complements the ecological advantages of clonality. Introduced Phragmites australis demonstrates great phenotypic plasticity in response to temperature, nutrient availability, geographic gradient, water depths, habitat fertility, atmospheric CO2, interspecific competition and intraspecific competition for light. However, no in situ comparative subspecies studies have explored the difference in plasticity between the non-invasive native lineage and the highly invasive introduced lineage. Clonality of the native and introduced lineages makes it possible to control for genetic variation, making P. australis a unique system for the comparative study of plasticity. Using previously identified clonal genotypes, we investigated differences in their phenotypic plasticity through measurements of the lengths and densities of stomata on both the abaxial (lower) and adaxial (upper) surfaces of leaves, and synthesized these measurements to estimate impacts on maximum stomatal conductance to water (gwmax). Results demonstrated that at three marsh sites, invasive lineages have consistently greater gwmax than their native congeners, as a result of greater stomatal densities and smaller stomata. Our analysis also suggests that phenotypic plasticity, determined as within-genotype variation in gwmax, of the invasive lineage is similar to, or exceeds, that shown by the native lineage.
Applying IsoTaG to understand Helicobacter pylori’s glycoprotein biosynthesis Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2021-01-01
Creator: Chiamaka Doris Okoye
Access: Access restricted to the Bowdoin Community
Can AFLP genome scans detect small islands of differentiation? The case of shell sculpture variation in the periwinkle Echinolittorina hawaiiensis
Date: 2011-08-01
Creator: Kimberly A. Tice, D. B. Carlon
Access: Open access
- Genome scans have identified candidate regions of the genome undergoing selection in a wide variety of organisms, yet have rarely been applied to broadly dispersing marine organisms experiencing divergent selection pressures, where high recombination rates can reduce the extent of linkage disequilibrium (LD) and the ability to detect genomic regions under selection. The broadly dispersing periwinkle Echinolittorina hawaiiensis exhibits a heritable shell sculpture polymorphism that is correlated with environmental variation. To elucidate the genetic basis of phenotypic variation, a genome scan using over 1000 AFLP loci was conducted on smooth and sculptured snails from divergent habitats at four replicate sites. Approximately 5% of loci were identified as outliers with Dfdist, whereas no outliers were identified by BayeScan. Closer examination of the Dfdist outliers supported the conclusion that these loci were false positives. These results highlight the importance of controlling for Type I error using multiple outlier detection approaches, multitest corrections and replicate population comparisons. Assuming shell phenotypes have a genetic basis, our failure to detect outliers suggests that the life history of the target species needs to be considered when designing a genome scan. © 2011 The Authors. Journal of Evolutionary Biology © 2011 European Society For Evolutionary Biology.
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.
When is Change Possible? Presidential Power as Shaped by Political Context, Constitutional Tools, and Legislative Skills
Date: 2021-01-01
Creator: Ryan Telingator
Access: Open access
- Many Americans believe that the president is an omnipotent figure who can achieve any political or policy objective if they try hard enough. On the contrary, the presidency was intentionally crafted by the Framers of the Constitution to have limited legislative powers to mitigate the risk of despotism. Thus, this paper seeks to answer the question, when is change possible?, to try to bridge the gap between popular belief and Constitutional powers. Three questions guide this research: 1) What conditions are conducive for change? 2) What Constitutional tools help a president facilitate change? And 3) What skills can a president bring to office to help create change? This thesis seeks to answer these questions by reviewing the existing literature on political context, tools, and legislative skills. Case study analyses of the Lyndon Johnson and Ronald Reagan presidencies are then presented to assess their legislative successes and failures, and the factors behind them. Finally, the thesis concludes by evaluating President Joseph Biden’s first 100 days in office and uses the theory and findings from the cases to predict Biden’s ability to affect change. This research reveals that the political context is the most important factor in determining the possibility of change – successful change relies on open policy windows, resilient ideological commitments, and a mandate to stimulate congressional action. Within the constraints of the case studies, Constitutional tools were not important. Legislative skills helped to pass legislation, however, they were not potent enough to overcome a bad political context.
Characterizing the exhumation path of the first ultrahigh-pressure terrane in North America Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2015-05-01
Creator: Zachary FM Burton
Access: Access restricted to the Bowdoin Community
An AGN as a Counterpart for Neutrino Event IceCube-220303A
Date: 2024-01-01
Creator: Nur Schettino
Access: Open access
- Cosmic rays have been detected for over a century. While some sources have been confirmed, they cannot explain the high energy of the particles (> 10^15 eV), so it remains unclear where and how they are accelerated to extreme energies. The study of astrophysical high-energy neutrinos may help solve the puzzle. These neutrinos are produced by cosmic rays interacting with other charged particles or photons. Moreover, while cosmic rays do not reveal their sources of origin because they can be deflected by magnetic fields, cosmic neutrinos detected by the IceCube Observatory can be traced back to their sources of origin. We will consider an active galactic nucleus (AGN) as a candidate source for a high-energy neutrino.This thesis examines the AGN WISEA J175051.31+105645.3 as a potential source for IceCube-220303A, a high-energy neutrino with a 78% probability of being astrophysical in origin. Using follow-up NuSTAR and Swift/XRT observations, WISEA J175051.31+105645.3 was the only viable source we found in IceCube-220303A’s uncertainty region. We used follow-up X-ray data to construct a multi-wavelength spectral energy distribution (SED) through which we calculated the AGN’s neutrino energy flux. This calculation yields the number of neutrinos we would expect to detect from the AGN in a given time period. We used this number to calculate the probability that IceCube-220303A was emitted by WISEA J175051.31+105645.3. Finding a statistically significant link between IceCube-220303A and WISEA J175051.31+105645.3 may help us better understand what processes can accelerate particles like cosmic rays to extreme energies and learn more about AGN.
Modulation of the stretch feedback pathway in the cardiac neuromuscular system of the American lobster, Homarus americanus
Date: 2024-01-01
Creator: Karin van Hassel
Access: Open access
- The cardiac ganglion (CG) is a central pattern generator, a neural network that, when activated, produces patterned motor outputs such as breathing and walking. The CG induces the heart contractions of the American lobster, Homarus americanus, making the lobster heart neurogenic. In the American lobster, the CG is made up of nine neurons: four premotor pacemaker neurons that send signals to five motor neurons, causing bursts of action potentials from the motor neurons. These bursts cause cardiac muscle contractions that vary in strength based on the burst duration, frequency, and pattern. The activity of the CG is modulated by feedback pathways and neuromodulators, allowing for flexibility in the CG’s motor output and appropriate responses to changes in the animal’s environment. Two feedback pathways modulate the CG motor output, the excitatory cardiac muscle stretch and inhibitory nitric oxide feedback pathways. Despite our knowledge of the modulation of the CG by feedback pathways and neuromodulators separately, little is known about how neuromodulators influence the sensory feedback response to cardiac muscle stretch. I found one neuromodulator to modulate each phase of the stretch response differently, one neuromodulator to generally not affect the stretch response, and three neuromodulators to suppress the stretch response. These results suggest neuromodulators can act to produce flexibility in a CPG’s motor output, allowing the system to respond appropriately to changes in an organism’s environment, and allow for variation in CPG responses to different stimuli.