Showing 1301 - 1350 of 5831 Items
Sex- and age-specific susceptibility of parvalbumin neurons to DNA methylation in a model of early life adversity This record is embargoed.
- Embargo End Date: 2025-05-19
Date: 2022-01-01
Creator: Alissa Chen
Access: Embargoed
Religious Negotiation and Identity Formation: Reading Material Religion in Oaxaca’s “Guelaguetza Oficial”
Date: 2023-01-01
Creator: Rene Sebastian Cisneros
Access: Open access
- The Oaxacan Guelaguetza Oficial is a folk-dance festival in the state of Oaxaca, Mexico which takes place on the last two Mondays of July each year. This state-sponsored celebration of Oaxacan identity is intertwined within histories of Indigenous religious belief and Catholic everyday practice. The Guelaguetza Oficial can be traced back to late 19thcentury celebrations venerating the Virgen del Carmen Alto. Oaxaqueños today predominantly practice an Indigenous-Catholic tradition whose rituals, festive scripts, pantheon of popular saints, and immanent understandings of heavenly power over earthly events can be traced back to negotiations between Indigenous forms of popular belief and institutionalized Catholic practice. Through historical and present-day religious tensions between existing modes of Indigenous religious belief and institutionalized Oaxacan Catholic practice, this thesis asserts that while Indigeneity often represented an obstacle to different structures of power in Mexican history, hegemonic institutions eventually came to accept the lasting presence of Indigenous identity and religious life to varying degrees within Mexican society and culture. This resulting reading of Guelaguetza demonstrates how religion is fundamentally implicated in the history of public festival and popular culture in Oaxaca. Furthermore, this thesis argues that Indigenous-Catholicism has not lost its prominence in public space in Oaxaca despite the reforms of post-1910 Oaxacan state and Mexican national politics and the effects of globalized neoliberal economies in the late 20th and early 21st centuries.
Timing the Paleozoic Oxygenation of the Deep Ocean Using Thallium Isotopes This record is embargoed.
- Embargo End Date: 2028-05-17
Date: 2023-01-01
Creator: Jean Nikolas R. Clemente
Access: Embargoed
Sensitivity Analysis of Basins of Attraction for Nelder-Mead
Date: 2022-01-01
Creator: Sonia K. Shah
Access: Open access
- The Nelder-Mead optimization method is a numerical method used to find the minimum of an objective function in a multidimensional space. In this paper, we use this method to study functions - specifically functions with three-dimensional graphs - and create images of the basin of attraction of the function. Three different methods are used to create these images named the systematic point method, randomized centroid method, and systemized centroid method. This paper applies these methods to different functions. The first function has two minima with an equivalent function value. The second function has one global minimum and one local minimum. The last function studied has several minima of different function values. The systematic point method is a reliable method in particular scenarios but is extremely sensitive to changes in the initial simplex. The randomized centroid method was not found to be useful as the basin of attraction images are difficult to understand. This made it particularly troublesome to know when the method was working effectively and when it was not. The systemized centroid method appears to be the most precise and effective method at creating the basin of attraction in most cases. This method rarely fails to find a minimum and is particularly adept at finding global minima more effectively compared to local minima. It is important to remember that these conclusions are simply based off the results of the methods and functions studied and that more effective methods may exist.
"In Loving Virtue": Staging the Virgin Body in Early Modern Drama
Date: 2022-01-01
Creator: Miranda Viederman
Access: Open access
- The aim of this Honors project is to investigate representations of female virginity in Renaissance English dramatic works. I view the period as one in which the womb became the site of a unique renewal of cultural anxieties surrounding the stability of the patriarchy and the inaccessibility of female sexual desire. I am most interested in virginity as a “bodily narrative” dependent on the construction and maintenance of performance. I analyze representations of virginity in female characters from four works of drama originating in the Jacobean period of the English Renaissance, during and after the end of the reign of Elizabeth I, the Virgin Queen. Across four chapters, I examine the characters of Isabella from Shakespeare’s Measure for Measure (1604), Beatrice-Joanna from Thomas Middleton’s The Changeling (1622), the Jailer’s Daughter from Shakespeare and Fletcher’s The Two Noble Kinsmen (1634), and Helen from Shakespeare’s All’s Well That Ends Well (c. 1602-1605). To establish a framework for my readings, I situate each work in its contemporary cultural context, drawing upon Catholic and Protestant religious doctrines, period medical texts, and popular culture. I intend to explore the complex, often contradictory nature of the forms of virginity the plays depict. Still, I hope by uncovering the opportunities these four characters are provided by their virginity, that I can widen the confines of the category.
#IVFgotyou: Instagram IVF Influencers as Social (Media) Support Systems
Date: 2023-01-01
Creator: Susu Gharib
Access: Open access
- This paper details the ways in which IVF and infertility influencers on Instagram use their platforms to resist the silence surrounding reproductive difficulties. The analysis draws upon a thematic analysis of posts tagged with IVF-related hashtags and a semi-structured ethnographic interview with one influencer. Through these methods, I found that influencers build intimate publics through their platforms by sharing their journeys, interacting with followers, and reciprocal support. Within the context of the intimate publics, influencers are able to connect with others who understand their experiences, allowing them to break through the silence they may feel in their offline social groups.
Differential modulation of the Homarus americanus cardiac neuromuscular system across cell types and among neuropeptide isoforms Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2020-01-01
Creator: Emily R Oleisky
Access: Access restricted to the Bowdoin Community
From local to global behavior in competitive Lotka-Volterra systems
Date: 2003-01-01
Creator: E. C. Zeeman, M. L. Zeeman
Access: Open access
- In this paper we exploit the linear, quadratic, monotone and geometric structures of competitive Lotka-Volterra systems of arbitrary dimension to give geometric, algebraic and computational hypotheses for ruling out nontrivial recurrence. We thus deduce the global dynamics of a system from its local dynamics. The geometric hypotheses rely on the introduction of a split Liapunov function. We show that if a system has a fixed point p ∈ int R+n and the carrying simplex of the system lies to one side of its tangent hyperplane at p, then there is no nontrivial recurrence, and the global dynamics are known. We translate the geometric hypotheses into algebraic hypotheses in terms of the definiteness of a certain quadratic function on the tangent hyperplane. Finally, we derive a computational algorithm for checking the algebraic hypotheses, and we compare this algorithm with the classical Volterra-Liapunov stability theorem for Lotka-Volterra systems.
Protein Transition: Alternative Proteins and Policy Pathways to a More Sustainable Diet in the United States This record is embargoed.
- Embargo End Date: 2025-05-14
Date: 2020-01-01
Creator: Anna Barnes
Access: Embargoed
Analysis of adhesion mutants in Arabidopsis thaliana This record is embargoed.
- Embargo End Date: 2025-05-14
Date: 2020-01-01
Creator: Bridgid Elizabeth Greed
Access: Embargoed
Bowdoin College - Medical School of Maine Catalogue (1918-1919)
Date: 1919-01-01
Access: Open access
- Bowdoin College Bulletin no. 83
Bowdoin College Catalogue (1918-1919, 2nd and 3rd terms)
Date: 1919-01-01
Access: Open access
- Bowdoin College Bulletin no. 86
Bowdoin College - Medical School of Maine Catalogue (1917-1918)
Date: 1918-01-01
Access: Open access
- Bowdoin College Bulletin no. 75
Computational Investigation of the Ground States and Luminescent Excited States of Ruthenium(II) and Platinum(II) Photoactive Complexes: Insights into the Design of New Ruthenium(II)-Based Molecular Photocatalysts and Enhanced Understanding of Metal-Metal Bonded Exciplexes Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2020-01-01
Creator: Thomas Regan
Access: Access restricted to the Bowdoin Community
Bowdoin College Catalogue (1926-1927)
Date: 1927-01-01
Access: Open access
- Bowdoin College Bulletin no. 161
Genetic Population Structure and Accuracy of Morphological Assessment in Alosa aestivalis (Blueback Herring) and A. pseudoharengus (Alewife)
Date: 2017-12-01
Creator: Christopher Kan, John Lichter, Vladimir Douhovnikoff
Access: Open access
- Alosa aestivalis and A. pseudoharengus are herring congeners that are important forage species for piscivorous fish and birds. We measured population structure metrics for these species using microsatellite markers. The Southern Gulf of Maine study area allowed the assessment of these species at an inter- and intra-watershed level. We found no detectable population structure within or among watershed for either species which agrees with other recent research. Our results support regional-scale (e.g., Gulf of Maine) plans for management for A. aestivalis and A. pseudoharengus. We found that 5.4% of our samples were hybrids. Our study adds to a growing body of evidence that hybridization and introgression should be management concerns for these species, and precautions should be taken to preserve species barriers. An error rate of morphological identification was calculated by comparing morphological identifications against genetic classifications. We found an overall identification error rate of 16%, which differed significantly from zero (P = 0.008). Managers should also take note of the uncertainty in morphological identifications and adjust stock models and policies accordingly.
Salix exigua clonal growth and population dynamics in relation to disturbance regime variation
Date: 2005-01-01
Creator: Vladimir Douhovnikoff, Joe R. McBride, Richard S. Dodd
Access: Open access
- Willows are important riparian colonizers. However, the predominant models of early riparian colonization, which emphasize seedling recruitment, are inadequate to explain the success of these species in light of the extremely low rates of seedling survival observed. We used molecular fingerprinting markers (AFLPs) to identify and characterize Salix exigua clones on six sites, ranging in size from 850 to 1150 m2, located on two rivers. Clones as large as 325 m2 were detected, and an average of six clones per site occupied 75% of the vegetated area. Building on Mahoney and Rood's recruitment box model, we propose a model whereby prolific clonal growth allows for long-term colonization of riparian zones, and the balance between the relative importance of seedling regeneration and clonal growth varies based upon disturbance regime. A reduction in disturbance regime resulted in greater clonal growth and reduced genotypic variation. It is probable that, with an extended reduction in disturbance, the Salix exigua component would be represented by fewer, larger clones and would eventually decline significantly when these clones are replaced by taller and more shade tolerant species. © 2005 by the Ecological Society of America.
Bowdoin College Catalogue (1938-1939)
Date: 1939-01-01
Access: Open access
- Bowdoin College Bulletin no. 244
Salton Collection : Renaissance & Baroque Medals & Plaquettes
Date: 1965-01-01
Access: Open access
- "The present collection ... belongs to Mr. and Mrs. Mark Salton of New York." "One thousand five hundred copies of this catalogue have been printed ... Composiiton by the Anthoensen Press, Portland, Maine. Photography by John McKee. Design by Leonard Baskin. January MCMLXX"--Colophon A revised edition of this catalogue published in 1969 is also available.
Bowdoin College Catalogue (1905-1906)
Date: 1906-01-01
Access: Open access
- Bowdoin College Bulletin no. 5
Sign Under the Domino Robinson-Schensted Maps
Date: 2014-01-01
Creator: Thomas Pietraho
Access: Open access
- We generalize a formula obtained independently by Reifegerste and Sjöstrand for the sign of a permutation under the classical Robinson-Schensted map to a family of domino Robinson-Schensted algorithms. © 2014 Springer Basel.
Midazolam-induced amnesia reduces memory for details and affects the ERP correlates of recollection and familiarity
Date: 2012-02-01
Creator: Erika Nyhus, Tim Curran
Access: Open access
- Dual process models suggest that recognition memory is supported by familiarity and recollection processes. Previous research administering amnesic drugs and measuring ERPs during recognition memory have provided evidence for separable neural correlates of familiarity and recollection. This study examined the effect of midazolam-induced amnesia on memory for details and the proposed ERP correlates of recognition. Midazolam or saline was administered while subjects studied oriented pictures of common objects. ERPs were recorded during a recognition test 1 day later. Subjects' discrimination of old and new pictures as well as orientation discrimination was worse when they were given midazolam instead of saline. As predicted, the parietal old/new effect was decreased with the administration of midazolam. However, weaker effects on FN400 old/new effects were also observed. These results provide converging pharmacological and electrophysiological evidence that midazolam primarily affects recollection as indexed by parietal ERP old/new effects and memory for orientation, while also exerting some weaker effects on familiarity as indexed by FN400 old/new effects. © 2011 Massachusetts Institute of Technology.
Neural inhibition enables selection during language processing
Date: 2010-09-21
Creator: Hannah R. Snyder, Natalie Hutchison, Erika Nyhus, Tim Curran, Marie T., Banich, Randall C. O'Reilly, Yuko Munakata
Access: Open access
- Whether grocery shopping or choosing words to express a thought, selecting between options can be challenging, especially for people with anxiety. We investigate the neural mechanisms supporting selection during language processing and its breakdown in anxiety. Our neural network simulations demonstrate a critical role for competitive, inhibitory dynamics supported by GABAergic interneurons. As predicted by our model, we find that anxiety (associated with reduced neural inhibition) impairs selection among options and associated prefrontal cortical activity, even in a simple, nonaffective verb-generation task, and the GABA agonist midazolam (which increases neural inhibition) improves selection, whereas retrieval from semantic memory is unaffected when selection demands are low. Neural inhibition is key to choosing our words.
BEING CAYLEY AUTOMATIC IS CLOSED under TAKING WREATH PRODUCT with VIRTUALLY CYCLIC GROUPS
Date: 2021-12-13
Creator: Dmitry Berdinsky, Murray Elder, Jennifer Taback
Access: Open access
- We extend work of Berdinsky and Khoussainov ['Cayley automatic representations of wreath products', International Journal of Foundations of Computer Science 27(2) (2016), 147-159] to show that being Cayley automatic is closed under taking the restricted wreath product with a virtually infinite cyclic group. This adds to the list of known examples of Cayley automatic groups.
The Soviet and American Wars in Afghanistan: Applying Clausewitzian Concepts to Modern Military Failure
Date: 2020-01-01
Creator: Artur Kalandarov
Access: Open access
- This paper evaluates the validity of three concepts from Carl von Clausewitz’s On War as they relate to contemporary military conflict. Utilizing the Soviet and American Wars in Afghanistan as case studies, the paper also offers a model for comparative conflict analysis by expanding upon Clausewitz’s culminating point concept. It argues that – despite limitations to Clausewitz’s theory of war – his concepts of culminating points in military operations, mass and concentration, and changing war aims provide useful insights into counterinsurgency military failures. Chapter One identifies the Soviet and American culminating points. Concluding that the concept of a culminating point is not applicable to the means and objectives of insurgents, it expands upon Clausewitzian theory by presenting an effectual substitute: the Counterinsurgent Acceptance Point. This is the author’s idea, and it is defined as the moment at which the counterinsurgents first publicly call for negotiations with the enemy. As the first public acknowledgment that the insurgents have denied the counterinsurgents a strictly military resolution to the conflict, it marks a crucial shift in the political framework of the war and is a fitting antithesis to the culminating point. Chapters Two and Three show how an inadequate troop presence and unclear war aims harmed Soviet and American efforts in Afghanistan. The development of insurgencies in both wars are studied to pinpoint when both country’s leaderships failed to adopt a Clausewitzian view of war, despite calls to do so by General Colin Powell in 2001 and Marshal Nikolai Ogarkov in 1979.
Bowdoin College Catalogue (1912-1913)
Date: 1913-01-01
Access: Open access
- Bowdoin College Bulletin no. 44
A note on convexity properties of Thompson's group F
Date: 2012-01-01
Creator: Matthew Horak, Melanie Stein, Jennifer Taback
Access: Open access
- We prove that Thompson's group F is not minimally almost convex with respect to any generating set which is a subset of the standard infinite generating set for F and which contains x1. We use this to show that F is not almost convex with respect to any generating set which is a subset of the standard infinite generating set, generalizing results in [4]. © Gruyter 2012.
The role of behavioral diversity in determining the extent to which the cardiac ganglion is modulated in three species of crab
Date: 2020-01-01
Creator: Grace Bukowski-Thall
Access: Open access
- Central pattern generators (CPGs) are neural networks that generate the rhythmic outputs that control behaviors such as locomotion, respiration, and chewing. The stomatogastric nervous system (STNS), which contains the CPGs that control foregut movement, and the cardiac ganglion (CG), which is a CPG that controls heartbeat, are two commonly studied systems in decapod crustaceans. Neuromodulators are locally or hormonally released neuropeptides and amines that change the output patterns of CPGs like the STNS and CG to allow behavioral flexibility. We have hypothesized that neuromodulation provides a substrate for the evolution of behavioral flexibility, and as a result, systems exhibiting more behavioral flexibility are modulated to a greater degree. To examine this hypothesis, we evaluated the extent to which the STNS and the CG are modulated in the majoid crab species Chionoecetes opilio, Libinia emarginata, and Pugettia producta. C. opilio and L. emarginata are opportunistic feeders, whereas P. producta has a highly specialized kelp diet. We predicted that opportunistic feeding crabs that chew and process a wide variety of food types would exhibit greater STNS neuromodulatory capacity than those with a specialized diet. The STNS of L. emarginata and C. opilio responded to the seven endogenous neuromodulators oxotremorine, dopamine, CabTrp Ia, CCAP, myosuppressin, proctolin, and RPCH, whereas the STNS of P. producta only responded to proctolin, oxotremorine, myosuppressin, RPCH (25% of the time), variably to dopamine, and not at all to CabTrp and CCAP. Because P. producta, L. emarginata, and C. opilio all belong to the Majoidea superfamily, their primary distinctions are their feeding habits. For this reason, we further predicted that there would be no relationship between diet and modulatory capacity in the cardiac ganglion (CG) of the neurogenic heart. This would suggest that a lack of STNS modulatory capacity in P. producta relative to L. emarginata and C. opilio is specific to evolved foregut function. Whole-heart recordings from P. producta indicated that, unlike the STNS, the CG responds to CabTrp and CCAP. P. producta hearts also responded to oxotremorine and inconsistently to dopamine and proctolin. The CG of C. opilio was modulated by CabTrp, CCAP, dopamine, proctolin, myosuppressin, and oxotremorine, but not RPCH. The CG of L. emarginata responded to CCAP, and inconsistently to CabTrp, dopamine, and proctolin, but not to myosuppressin, RPCH, and surprisingly oxotremorine. Although cardiac responses were not identical between species, opportunistic and specialist feeders responded more similarly to the modulators tested in the heart than in the STNS. Notably, P. producta responded to each modulator in a similar manner to C. opilio and/or L. emarginata. However, L. emarginata’s surprising lack of cardiac response to oxotremorine suggests that phylogenetic closeness may not control for differences in CG and STNS function between species. Nevertheless, sample sizes of all three species were quite small, and individual differences lead to inconsistencies in the data. As a result, sample size must be enlarged to draw firm conclusions.
An Arabidopsis cell wall-associated kinase required for invertase activity and cell growth
Date: 2006-04-01
Creator: Bruce D. Kohorn, Masaru Kobayashi, Sue Johansen, Jeff Riese, Li Fen, Huang, Karen Koch, Sarita Fu, Anjali Dotson, Nicole Byers
Access: Open access
- The wall-associated kinases (WAK), a family of five proteins that contain extracellular domains that can be linked to pectin molecules of the cell wall, span the plasma membrane and have a cytoplasmic serine/threonine kinase domain. Previous work has shown that a reduction in WAK protein levels leads to a loss of cell expansion, indicating that these receptor-like proteins have a role in cell shape formation. Here it is shown that a single wak2 mutation exhibits a dependence on sugars and salts for seedling growth. This mutation also reduces the expression and activity of vacuolar invertase, often a key factor in turgor and expansion. WAKs may thus provide a molecular mechanism linking cell wall sensing (via pectin attachment) to regulation of solute metabolism, which in turn is known to be involved in turgor maintenance in growing cells. © 2006 The Authors.
“I felt so untrustworthy of my ability to get pregnant”: Women’s Embodied Uncertainties and Decisions to Become Pregnant
Date: 2020-01-01
Creator: Theodora K. Hurley
Access: Open access
- This paper identifies “embodied uncertainties”—possibilities of aging and infertility lodged within the body—as informing women’s conceptualizations of their reproductive bodies and their decisions about and approaches to getting pregnant. Using data from semi-structured interviews with a small sample of highly educated, professional, white women who had given birth within 18 months prior, this paper argues that (bio)medicalized risk discourses and neoliberal logics of responsible choice-making lodge uncertainty and the possibility of failure within women’s reproductive bodies. As they attempt to reconcile childbearing with professional and financial constraints, women may identify their bodies as laden with embodied uncertainties and may subsequently adopt strategies for becoming pregnant that seek to mitigate those embodied uncertainties, such as by trying to conceive before feeling completely ready for a pregnancy. Ultimately, (bio)medicalization and neoliberalism have transformed reproductive aging and infertility into individualized concerns and foreclosed recognition of the institutional failures that create conflicts of aging, careers, and childbearing in women’s lives.
Spatially variable syn- and post-orogenic exhumation of the Appalachian Mountains from apatite and zircon (U-Th)/He thermochronology
Date: 2020-01-01
Creator: Luke Coughtry Basler
Access: Open access
- We present zircon and apatite (U-Th)/He (ZHe, closure temperature = 150-200ºC; AHe, closure temperature = 45-80ºC) results from two study regions in the Appalachians Mountains to investigate the timing, rates, and spatial trends of exhumation during Alleghanian orogenesis, Atlantic rifting, and post-rift passive margin conditions. Within West Virginia and Virginia, 10 ZHe dates along an across-orogen transect display an eastward younging trend, from ~425 million years (Ma) in the western Appalachian Plateau province, to ~250-300 Ma in the central Valley-Ridge fold-thrust belt, and 163 ± 29 Ma in the eastern Piedmont. Inverse thermal modeling of ZHe data using external geologic constraints indicates: (1) Pre-depositional cooling signatures within Pennsylvanian Appalachian Plateau rocks, suggesting provenance from recycled Taconic or Acadian basin strata, (2) Rapid Alleghanian (250-300 Ma) cooling in the Valley and Ridge province, indicating syn-orogenic uplift and exhumation, followed by a protracted period of stable syn-rift thermal conditions from ~250-150 Ma, and (3) Rapid rift-induced cooling in the Piedmont province, likely caused by rift-flank uplift and the post-rift lessening of the geothermal gradient. Within the Northern Appalachians of Vermont, four metamorphic samples yield averaged AHe dates of 100-120 Ma. Inverse thermal modeling indicates stable thermal conditions from 90 Ma to the present, limiting cooling driven by the recently recognized Northern Appalachian lithospheric thermal anomaly to < 20ºC. Modeling also indicates steady mid-Cretaceous (120-90 Ma) cooling (70 to 30ºC) coeval with passage over the Great Meteor Hotspot, although cooling rates are slower than would be expected during hotspot-induced thermal doming.
Bowdoin College - Medical School of Maine Catalogue (1914-1915)
Date: 1915-01-01
Access: Open access
- Bowdoin College Bulletin no. 55
Bowdoin College Catalogue (1927-1928)
Date: 1928-01-01
Access: Open access
- Bowdoin College Bulletin no. 169