Showing 2501 - 2550 of 5831 Items

Who benefits? How interest-convergence shapes benefit-sharing and indigenous rights to sustainable livelihoods in Russia

Date: 2020-11-01

Creator: Maria S. Tysiachniouk, Laura A. Henry, Svetlana A. Tulaeva, Leah S. Horowitz

Access: Open access

The paper examines interactions of oil companies and reindeer herders in the tundra of the Russian Arctic. We focus on governance arrangements that have an impact on the sustainability of oil production and reindeer herding. We analyze a shift in benefit-sharing arrangements between oil companies and Indigenous Nenets reindeer herders in Nenets Autonomous Okrug (NAO), Russia, as an evolution of the herders’ rights, defined as the intertwined co-production of legal processes, ideologies, and power relations. Semi-structured interviews, participant observation, and document analysis demonstrate that in NAO, benefit-sharing shifted from paternalism (dependent on herders’ negotiation skills) to company-centered social responsibility (formalized compensation rules). This shift was enabled by the adoption of a formal methodology for calculating income lost due to extractive projects and facilitated by the regional government’s efforts to develop reindeer-herding. While laws per se did not change, herders’ ability to access compensation and markets increased. This paper shows that even when ideologies of indigeneity are not influential, the use of existing laws and convergence of the government’s and Indigenous groups’ economic interests may shift legal processes and power relations toward greater rights for Indigenous groups.


Bowdoin College Catalogue (1881-1882)

Date: 1882-01-01

Access: Open access



Private forest governance, public policy impacts: The Forest Stewardship Council in Russia and Brazil

Date: 2017-11-16

Creator: Lisa Mc Intosh Sundstrom, Laura A. Henry

Access: Open access

Under what conditions do private forest governance standards influence state policy and behavior to become more oriented toward sustainability? We argue that governance schemes targeting firms may indirectly shape state behavior, even when designed to bypass state regulation. Through an examination of the Forest Stewardship Council (FSC) in Russia and Brazil, we find that the FSC has influenced domestic rhetoric, laws, and enforcement practices. FSC has had a more disruptive and consequential impact on Russia's domestic forest governance; in Brazil, earlier transnational environmental campaigns had already begun to shift domestic institutions toward sustainability. Based on interview data and textual analysis of FSC and government documents, we identify the mechanisms of indirect FSC influence on states-professionalization, civil society mobilization, firm lobbying, and international market pressure, and argue that they are likely to be activated under conditions of poor and decentralized governance, overlapping and competing regulations and high foreign market demand for exports.


Report of the President, Bowdoin College 1992-1993

Date: 1993-01-01

Access: Open access



Context-specific effects of vasotocin on social approach in the male common goldfish, Carassius auratus

Date: 2019-05-01

Creator: Katharine Torrey

Access: Open access

The peptide vasotocin (VT) and its mammalian homologue, vasopressin (VP), produce effects on social behavior that are highly species- and context-specific. We recently sequenced two genes for V1a-like receptors (VTR) in the goldfish brain, one that encodes for a fully-functioning canonical receptor and one that encodes for a non-functional truncated receptor. The current study is an investigation of whether social context may alter expression of these receptor types and thus, potentially, behavioral responses to VT. We used western blotting and immunohistochemistry with custom anti-VTR antibodies to characterize the distribution of VTR throughout the forebrain and the hindbrain. Western blot results showed bands close to the predicted sizes for truncated and canonical VTR constructs, suggesting that both genes are translated into protein in the brain, but the presence of additional bands suggested potential nonspecific binding. Immunohistochemistry data revealed VTR signal throughout the brain in regions associated with social behavior. We additionally examined whether visual and olfactory context alters behavioral responsiveness to VT, potentially by altering the expression of one or both receptors. Behavioral tests suggested that VT inhibits approach to males, but its effect on response to females in reproductive contexts is still undetermined, likely due to interference from a stress response during testing. Further characterization of VTR throughout the brain will clarify how social context might alter VT signaling through context-dependent modulation of its receptors. Additionally, future work should examine the behavioral consequences of such modulation by further studying whether VT’s effect on social approach behavior depends on context.


Wave mixing in coupled phononic crystals via a variable stiffness mechanism

Date: 2016-10-01

Creator: Gil Yong Lee, Christopher Chong, Panayotis G. Kevrekidis, Jinkyu Yang

Access: Open access

We investigate wave mixing effects in a phononic crystal that couples the wave dynamics of two channels – primary and control ones – via a variable stiffness mechanism. We demonstrate analytically and numerically that the wave transmission in the primary channel can be manipulated by the control channel's signal. We show that the application of control waves allows the selection of a specific mode through the primary channel. We also demonstrate that the mixing of two wave modes is possible whereby a modulation effect is observed. A detailed study of the design parameters is also carried out to optimize the switching capabilities of the proposed system. Finally, we verify that the system can fulfill both switching and amplification functionalities, potentially enabling the realization of an acoustic transistor.


Modelling ecosystem services in terrestrial systems

Date: 2010-07-22

Creator: Erik J. Nelson, Gretchen C. Daily

Access: Open access

Over the past few decades, a multi-disciplinary research community has documented the goods and services provided by ecosystems in specific sites scattered across the world. This research community has now begun to focus on creating methods and tools for mapping and valuing the ecosystem services produced on any landscape in the world. We describe some of these methods and tools and how they calculate and express ecosystem service provision and value on landscapes. We also describe methods for predicting landscape change. These predictions can be used by multi-ecosystem service models to assess potential changes and trade-offs in ecosystem service provision and values into the future. © 2010 Faculty of 1000 Ltd.


A tale of two exponentiations in N = 8 supergravity at subleading level

Date: 2020-03-01

Creator: Paolo Di Vecchia, Stephen G. Naculich, Rodolfo Russo, Gabriele Veneziano, Chris D., White

Access: Open access

High-energy massless gravitational scattering in N = 8 supergravity was recently analyzed at leading level in the deflection angle, uncovering an interesting connection between exponentiation of infrared divergences in momentum space and the eikonal exponentiation in impact parameter space. Here we extend that analysis to the first non trivial sub-leading level in the deflection angle which, for massless external particles, implies going to two loops, i.e. to third post-Minkowskian (3PM) order. As in the case of the leading eikonal, we see that the factorisation of the momentum space amplitude into the exponential of the one-loop result times a finite remainder hides some basic simplicity of the impact parameter formulation. For the conservative part of the process, the explicit outcome is infrared (IR) finite, shows no logarithmic enhancement, and agrees with an old claim in pure Einstein gravity, while the dissipative part is IR divergent and should be regularized, as usual, by including soft gravitational bremsstrahlung. Finally, using recent three-loop results, we test the expectation that eikonal formulation accounts for the exponentiation of the lower-loop results in the momentum space amplitude. This passes a number of highly non-trivial tests, but appears to fail for the dissipative part of the process at all loop orders and sufficiently subleading order in ϵ, hinting at some lack of commutativity of the relevant infrared limits for each exponentiation.


Stress alters rates and types of loss of heterozygosity in candida albicans

Date: 2011-01-01

Creator: A. Forche, D. Abbey, T. Pisithkul, M. A. Weinzierl, T., Ringstrom, D. Bruck, K. Petersen, J. Berman

Access: Open access

Genetic diversity is often generated during adaptation to stress, and in eukaryotes some of this diversity is thought to arise via recombination and reassortment of alleles during meiosis. Candida albicans, the most prevalent pathogen of humans, has no known meiotic cycle, and yet it is a heterozygous diploid that undergoes mitotic recombination during somatic growth. It has been shown that clinical isolates as well as strains passaged once through a mammalian host undergo increased levels of recombination. Here, we tested the hypothesis that stress conditions increase rates of mitotic recombination in C. albicans, which is measured as loss of heterozygosity (LOH) at specific loci. We show that LOH rates are elevated during in vitro exposure to oxidative stress, heat stress, and antifungal drugs. In addition, an increase in stress severity correlated well with increased LOH rates. LOH events can arise through local recombination, through homozygosis of longer tracts of chromosome arms, or by whole-chromosome homozygosis. Chromosome arm homozygosis was most prevalent in cultures grown under conventional lab conditions. Importantly, exposure to different stress conditions affected the levels of different types of LOH events, with oxidative stress causing increased recombination, while fluconazole and high temperature caused increases in events involving whole chromosomes. Thus, C. albicans generates increased amounts and different types of genetic diversity in response to a range of stress conditions, a process that we term "stress-induced LOH" that arises either by elevating rates of recombination and/or by increasing rates of chromosome missegregation. IMPORTANCE Stress-induced mutagenesis fuels the evolution of bacterial pathogens and is mainly driven by genetic changes via mitotic recombination. Little is known about this process in other organisms. Candida albicans, an opportunistic fungal pathogen, causes infections that require adaptation to different host environmental niches. We measured the rates of LOH and the types of LOH events that appeared in the absence and in the presence of physiologically relevant stresses and found that stress causes a significant increase in the rates of LOH and that this increase is proportional to the degree of stress. Furthermore, the types of LOH events that arose differed in a stress-dependent manner, indicating that eukaryotic cells generate increased genetic diversity in response to a range of stress conditions. We propose that this "stress-induced LOH" facilitates the rapid adaptation of C. albicans, which does not undergo meiosis, to changing environments within the host. © 2011 Forche et al.


Levels of DNA polymorphism vary with mating system in the nematode genus Caenorhabditis

Date: 2002-01-01

Creator: Andrew Graustein, John M. Caspar, James R. Walters, Michael F. Palopoli

Access: Open access

Self-fertilizing species often harbor less genetic variation than cross-fertilizing species, and at least four different models have been proposed to explain this trend. To investigate further the relationship between mating system and genetic variation, levels of DNA sequence polymorphism were compared among three closely related species in the genus Caenorhabditis: two self-fertilizing species, Caenorhabditis elegans and C. briggsae, and one cross-fertilizing species, C. remanei. As expected, estimates of silent site nucleotide diversity were lower in the two self-fertilizing species. For the mitochondrial genome, diversity in the selfing species averaged 42% of diversity in C. remanei. Interestingly, the reduction in genetic variation was much greater for the nuclear than for the mitochondrial genome. For two nuclear genes, diversity in the selfing species averaged 6 and 13% of diversity in C. remanei. We argue that either population bottlenecks or the repeated action of natural selection, coupled with high levels of selfing, are likely to explain the observed reductions in species-wide genetic diversity.


A database and synthesis of northern peatland soil properties and Holocene carbon and nitrogen accumulation

Date: 2014-09-01

Creator: Julie Loisel, Zicheng Yu, David W. Beilman, Philip Camill, Jukka, Alm, Matthew J. Amesbury, David Anderson, Sofia Andersson, Christopher Bochicchio, Keith Barber, Lisa R. Belyea, Joan Bunbury, Frank M. Chambers, Daniel J. Charman, François De Vleeschouwer, Barbara Fiałkiewicz-Kozieł

Access: Open access

Here, we present results from the most comprehensive compilation of Holocene peat soil properties with associated carbon and nitrogen accumulation rates for northern peatlands. Our database consists of 268 peat cores from 215 sites located north of 45°N. It encompasses regions within which peat carbon data have only recently become available, such as the West Siberia Lowlands, the Hudson Bay Lowlands, Kamchatka in Far East Russia, and the Tibetan Plateau. For all northern peatlands, carbon content in organic matter was estimated at 42 ± 3% (standard deviation) for Sphagnum peat, 51 ± 2% for non-Sphagnum peat, and at 49 ± 2% overall. Dry bulk density averaged 0.12 ± 0.07 g/cm3, organic matter bulk density averaged 0.11 ± 0.05 g/cm3, and total carbon content in peat averaged 47 ± 6%. In general, large differences were found between Sphagnum and non-Sphagnum peat types in terms of peat properties. Time-weighted peat carbon accumulation rates averaged 23 ± 2 (standard error of mean) g C/m2/yr during the Holocene on the basis of 151 peat cores from 127 sites, with the highest rates of carbon accumulation (25–28 g C/m2/yr) recorded during the early Holocene when the climate was warmer than the present. Furthermore, we estimate the northern peatland carbon and nitrogen pools at 436 and 10 gigatons, respectively. The database is publicly available at https://peatlands.lehigh.edu.


Report of the President, Bowdoin College 1915-1916

Date: 1916-01-01

Access: Open access



Genotypic evolution of azole resistance mechanisms in sequential Candida albicans isolates

Date: 2007-10-01

Creator: Alix Coste, Anna Selmecki, Anja Forche, Dorothée Diogo, Marie Elisabeth, Bougnoux, Christophe D'Enfert, Judith Berman, Dominique Sanglard

Access: Open access

TAC1 (for transcriptional activator of CDR genes) is critical for the upregulation of the ABC transporters CDR1 and CDR2, which mediate azole resistance in Candida albicans. While a wild-type TAC1 allele drives high expression of CDR1/2 in response to inducers, we showed previously that TAC1 can be hyperactive by a gain-of-function (GOF) point mutation responsible for constitutive high expression of CDR1/2. High azole resistance levels are achieved when C. albicans carries hyperactive alleles only as a consequence of loss of heterozygosity (LOH) at the TAC1 locus on chromosome 5 (Chr 5), which is linked to the mating-type-like (MTL) locus. Both are located on the Chr 5 left arm along with ERG11 (target of azoles). In this work, five groups of related isolates containing azole-susceptible and -resistant strains were analyzed for the TAC1 and ERG11 alleles and for Chr 5 alterations. While recovered ERG11 alleles contained known mutations, 17 new TAC1 alleles were isolated, including 7 hyperactive alleles with five separate new GOF mutations. Single-nucleotide- polymorphism analysis of Chr 5 revealed that azole-resistant strains acquired TAC1 hyperactive alleles and, in most cases, ERG11 mutant alleles by LOH events not systematically including the MTL locus. TAC1 LOH resulted from mitotic recombination of the left arm of Chr 5, gene conversion within the TAC1 locus, or the loss and reduplication of the entire Chr 5. In one case, two independent TAC1 hyperactive alleles were acquired. Comparative genome hybridization and karyotype analysis revealed the presence of isochromosome 5L [i(5L)] in two azole-resistant strains. i(5L) leads to increased copy numbers of azole resistance genes present on the left arm of Chr 5, among them TAC1 and ERG11. Our work shows that azole resistance was due not only to the presence of specific mutations in azole resistance genes (at least ERG11 and TAC1) but also to their increase in copy number by LOH and to the addition of extra Chr 5 copies. With the combination of these different modifications, sophisticated genotypes were obtained. The development of azole resistance in C. albicans is therefore a powerful instrument for generating genetic diversity. Copyright © 2007, American Society for Microbiology. All Rights Reserved.


Multiproxy lake sediment records at the northern and southern boundaries of the Aspen Parkland region of Manitoba, Canada

Date: 2009-09-01

Creator: Rebecca Teed, Charles Umbanhower, Philip Camill

Access: Open access

Aspen parkland in central Canada may change substantially with increased warming and aridity as prairies replace forests, fire return intervals decrease and lake levels decline. We examined the relationships among vegetation, climate, fire and lake-ecosystem properties using lake sediment cores from the current northern and southern boundaries of the aspen parkland in southwestern Manitoba. We analyzed pollen, charcoal, sediment magnetics, biogenic silica, phosphorus, grain size and LOI, and dated the cores using Pb and C (AMS, calibrated). The Jones Lake record, from the southern edge of the parkland, began considerably earlier (~11 000 cal. BP) than the Mallard Pond record at the northern edge (~8600 cal. BP). These sites were characterized as prairie communities with low fire severity and relatively low lake productivity during the warm, dry period from 9000 to 6000 cal. BP. Beginning around 6500 cal. BP at Jones Lake and 3400 cal. BP at Mallard Pond, conditions appeared to get wetter as indicated by arboreal pollen percentage increases from ~30% to 40-60%, concurrent with a rise in charcoal and proxies for lake productivity (biogenic silica and percent organic phosphorus). Similar to previous studies along the prairie-forest border, we found that charcoal increased during warmer, wetter periods with increased forest cover and fuel loading rather than during warmer, drier periods of prairie dominance. Our results underscore the importance of regional changes in moisture, and its effects on lake levels and forest biomass, as a dominant control of the aspen parkland dynamics. © The Author(s), 2009. 210 14


Flow around phoronids: Consequnces of a neighbor to suspension feeders

Date: 1990-01-01

Creator: Amy S. Johnson

Access: Open access

This article is in Free Access Publication and may be downloaded using the “Download Full Text PDF” link at right. © 1990, by the Association for the Sciences of Limnology and Oceanography, Inc.


Vital Statistics: American Folk Drawing and Watercolors from a Private Collection

Date: 1986-01-01

Creator: Philip M. Isaacson

Access: Open access

Catalog of an exhibition held at the Bowdoin College Museum of Art from Sept. 11 to Nov. 9, 1986


Miniature of Long Day with The Office: An Analysis of College Student Demand for Streaming Video on Netflix
Long Day with The Office: An Analysis of College Student Demand for Streaming Video on Netflix
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      Date: 2020-01-01

      Creator: Summers Askew

      Access: Access restricted to the Bowdoin Community



        Répresentations de la banlieue dans le cinéma français contemporain

        Date: 2020-01-01

        Creator: Yaw Owusu Sekyere

        Access: Open access

        Inhabitants of the poor French banlieues are rejected and isolated from the larger French society, who refuse to acknowledge their marginalization. As a result, the cycle continues where no political change is made. The French film genre, cinéma de banlieue, seeks to explain the perspectives of the underrepresented and marginalized groups within France. This honors project analyzes the representations of the banlieue through the films of La Haine (Mathieu Kassovitz), Wesh wesh qu’est-ce qui se passe ? (Rabah Ameur-Zaïmeche), Bande de filles (Céline Sciamma), Divines (Houda Benyamina), and Banlieusards (Kery James & Leïla Sy). These films focus on the themes of drugs, policial relations, the confinement of the banlieue, and the discrimination and stigmatisation that inhabitants of the poor banlieues face, all of which revolve around the idea of entrapment. This work intends to see if these representations of the banlieue, specifically on the periphery of Paris, perpetuate stereotypes, or propose a more complex dynamic.


        The state of cell wall pectin monitored by wall associated kinases: A model

        Date: 2015-07-03

        Creator: Bruce D. Kohorn

        Access: Open access

        The Wall Associated Kinases (WAKs) bind to both cross-linked polymers of pectin in the plant cell wall, but have a higher affinity for smaller fragmented pectins that are generated upon pathogen attack or wounding. WAKs are required for cell expansion during normal seedling development and this involves pectin binding and a signal transduction pathway involving MPK3 and invertase induction. Alternatively WAKs bind pathogen generated pectin fragments to activate a distinct MPK6 dependent stress response. Evidence is provided for a model for how newly generated pectin fragments compete for longer pectins to alter the WAK dependent responses.


        The Issue Focus of Online and Television Advertising in the 2016 Presidential Campaign

        Date: 2020-01-01

        Creator: Michael M. Franz, Erika Franklin Fowler, Travis Ridout, Meredith Yiran Wang

        Access: Open access

        Theories of campaign issue emphasis were developed in a pre-digital era. How well do these theories explain spending in the current era, when digital media allow for targeting of specific types of voters? In this research, we compare how the 2016 campaigns, both primary and general election, deployed television advertising with how they deployed online advertising. We suggest that, because online messages are targeted to specific viewer profiles much more than television messages, television ads should be more likely to discuss highly salient issues and valance issues than online ads. To test these ideas, we rely upon data from the Wesleyan Media Project, which tracked all televised political ads that aired in 2016, and our coding of data from Pathmatics, a company that tracks online advertising. We find, contrary to our expectations, that the predictors of issue discussion online and on television are largely similar.


        Selection of Candida albicans trisomy during oropharyngeal infection results in a commensal-like phenotype

        Date: 2019-05-01

        Creator: Anja Forche, Norma V. Solis, Marc Swidergall, Robert Thomas, Alison, Guyer, Annette Beach, Gareth A. Cromie, Giang T. Le, Emily Lowell, Norman Pavelka, Judith Berman, Aimeé M. Dudley, Anna Selmecki, Scott G. Filler

        Access: Open access

        When the fungus Candida albicans proliferates in the oropharyngeal cavity during experimental oropharyngeal candidiasis (OPC), it undergoes large-scale genome changes at a much higher frequency than when it grows in vitro. Previously, we identified a specific whole chromosome amplification, trisomy of Chr6 (Chr6x3), that was highly overrepresented among strains recovered from the tongues of mice with OPC. To determine the functional significance of this trisomy, we assessed the virulence of two Chr6 trisomic strains and a Chr5 trisomic strain in the mouse model of OPC. We also analyzed the expression of virulence-associated traits in vitro. All three trisomic strains exhibited characteristics of a commensal during OPC in mice. They achieved the same oral fungal burden as the diploid progenitor strain but caused significantly less weight loss and elicited a significantly lower inflammatory host response. In vitro, all three trisomic strains had reduced capacity to adhere to and invade oral epithelial cells and increased susceptibility to neutrophil killing. Whole genome sequencing of pre- and post-infection isolates found that the trisomies were usually maintained. Most post-infection isolates also contained de novo point mutations, but these were not conserved. While in vitro growth assays did not reveal phenotypes specific to de novo point mutations, they did reveal novel phenotypes specific to each lineage. These data reveal that during OPC, clones that are trisomic for Chr5 or Chr6 are selected and they facilitate a commensal-like phenotype.


        Mutation of an Arabidopsis Golgi membrane protein ELMO1 reduces cell adhesion

        Date: 2021-05-01

        Creator: Bruce D. Kohorn, Frances D.H. Zorensky, Jacob Dexter-Meldrum, Salem Chabout, Gregory, Mouille, Susan Kohorn

        Access: Open access

        Plant growth, morphogenesis and development involve cellular adhesion, a process dependent on the composition and structure of the extracellular matrix or cell wall. Pectin in the cell wall is thought to play an essential role in adhesion, and its modification and cleavage are suggested to be highly regulated so as to change adhesive properties. To increase our understanding of plant cell adhesion, a population of ethyl methanesulfonate-mutagenized Arabidopsis were screened for hypocotyl adhesion defects using the pectin binding dye Ruthenium Red that penetrates defective but not wild-type (WT) hypocotyl cell walls. Genomic sequencing was used to identify a mutant allele of ELMO1 which encodes a 20 kDa Golgi membrane protein that has no predicted enzymatic domains. ELMO1 colocalizes with several Golgi markers and elmo1-/- plants can be rescued by an ELMO1-GFP fusion. elmo1-/- exhibits reduced mannose content relative to WT but no other cell wall changes and can be rescued to WT phenotype by mutants in ESMERALDA1, which also suppresses other adhesion mutants. elmo1 describes a previously unidentified role for the ELMO1 protein in plant cell adhesion.


        A new data set for estimating organic carbon storage to 3 m depth in soils of the northern circumpolar permafrost region

        Date: 2013-12-23

        Creator: G. Hugelius, J. G. Bockheim, P. Camill, B. Elberling, G., Grosse, J. W. Harden, K. Johnson, T. Jorgenson, C. D. Koven, P. Kuhry, G. Michaelson, U. Mishra, J. Palmtag, J. O'Donnell, L. Schirrmeister, E. A.G. Schuur

        Access: Open access

        High-latitude terrestrial ecosystems are key components in the global carbon cycle. The Northern Circumpolar Soil Carbon Database (NCSCD) was developed to quantify stocks of soil organic carbon (SOC) in the northern circumpolar permafrost region (a total area of 18.7 × 106 km2). The NCSCD is a geographical information system (GIS) data set that has been constructed using harmonized regional soil classification maps together with pedon data from the northern permafrost region. Previously, the NCSCD has been used to calculate SOC storage to the reference depths 0–30 cm and 0–100 cm (based on 1778 pedons). It has been shown that soils of the northern circumpolar permafrost region also contain significant quantities of SOC in the 100–300 cm depth range, but there has been no circumpolar compilation of pedon data to quantify this deeper SOC pool and there are no spatially distributed estimates of SOC storage below 100 cm depth in this region. Here we describe the synthesis of an updated pedon data set for SOC storage (kg C m−2) in deep soils of the northern circumpolar permafrost regions, with separate data sets for the 100–200 cm (524 pedons) and 200–300 cm (356 pedons) depth ranges. These pedons have been grouped into the North American and Eurasian sectors and the mean SOC storage for different soil taxa (subdivided into Gelisols including the sub-orders Histels, Turbels, Orthels, permafrost-free Histosols, and permafrost-free mineral soil orders) has been added to the updated NCSCDv2. The updated version of the data set is freely available online in different file formats and spatial resolutions that enable spatially explicit applications in GIS mapping and terrestrial ecosystem models. While this newly compiled data set adds to our knowledge of SOC in the 100–300 cm depth range, it also reveals that large uncertainties remain. Identified data gaps include spatial coverage of deep (> 100 cm) pedons in many regions as well as the spatial extent of areas with thin soils overlying bedrock and the quantity and distribution of massive ground ice.©Author(s) 2013.


        Sponsorship, Disclosure, and Donors: Limiting the Impact of Outside Group Ads

        Date: 2015-03-25

        Creator: Travis N. Ridout, Michael M. Franz, Erika Franklin Fowler

        Access: Open access

        This research examines how an attack ad’s sponsorship conditions its effectiveness. We use data from a survey experiment that exposed participants to a fictional campaign ad. Treatments varied the ad’s sponsor (candidate vs. group), the group’s donor base (small donor vs. large donors), and the format of the donor disclosure (news reports vs. disclaimers in the ads). We find that ads sponsored by unknown groups are more effective than candidate-sponsored ads, but disclosure of donors reduces the influence of group advertising, leveling the playing field such that candidate- and group-sponsored attacks become equally effective. Increased disclosure does not, however, advantage small-donor groups over large-donor groups.


        Collecting for a College: Gifts from David P. Becker

        Date: 1995-01-01

        Creator: Marjorie B. Cohen

        Access: Open access

        Catalog of an exhibition held at the Bowdoin College Museum of Art Apr. 20-June 4, 1995.


        Miniature of Characterization of negative phonotactic behavior in the adult cricket, <i>Gryllus bimaculatus</i>
        Characterization of negative phonotactic behavior in the adult cricket, Gryllus bimaculatus
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            Date: 2020-01-01

            Creator: Julianne Scholes

            Access: Access restricted to the Bowdoin Community



              MAO-A phenotype effects response sensitivity and the parietal old/new effect during recognition memory

              Date: 2018-02-13

              Creator: Robert S. Ross, Andrew Smolen, Tim Curran, Erika Nyhus

              Access: Open access

              A critical problem for developing personalized treatment plans for cognitive disruptions is the lack of understanding how individual differences influence cognition. Recognition memory is one cognitive ability that varies from person to person and that variation may be related to different genetic phenotypes. One gene that may impact recognition memory is the monoamine oxidase A gene (MAO-A), which influences the transcription rate of MAO-A. Examination of how MAO-A phenotypes impact behavioral and event-related potentials (ERPs) correlates of recognition memory may help explain individual differences in recognition memory performance. Therefore, the current study uses electroencephalography (EEG) in combination with genetic phenotyping of the MAO-A gene to determine how well-characterized ERP components of recognition memory, the early frontal old/new effect, left parietal old/new effect, late frontal old/new effect, and the late posterior negativity (LPN) are impacted by MAO-A phenotype during item and source memory. Our results show that individuals with the MAO-A phenotype leading to increased transcription have lower response sensitivity during both item and source memory. Additionally, during item memory the left parietal old/new effect is not present due to increased ERP amplitude for correct rejections. The results suggest that MAO-A phenotype changes EEG correlates of recognition memory and influences how well individuals differentiate between old and new items.


              Statement by James Tierney collected by Heather Westleigh on November 19, 2014

              Date: 2014-11-19

              Creator: James Tierney

              Access: Audio recording permanently restricted



              Semantic and perceptual effects on recognition memory: Evidence from ERP

              Date: 2009-08-04

              Creator: Erika Nyhus, Tim Curran

              Access: Open access

              The present experiments examined how semantic vs. perceptual encoding and perceptual match affect the processes involved in recognition memory. Experiment 1 examined the effects of encoding task and perceptual match between study and test fonts on recognition discrimination for words. Font fan was used to determine the effect of distinctiveness on perceptual match. The semantic encoding task and perceptual match for distinctive items led to better recognition memory. Event-related brain potentials (ERPs) recorded from the human scalp during recognition memory experiments have revealed differences between old (studied) and new (not studied) items that are thought to reflect the activity of memory-related brain processes. In Experiment 2, the semantic encoding task and perceptual match for distinctive words led to better recognition memory by acting on both familiarity and recollection processes, as purportedly indexed by the FN400 and parietal old/new effects. Combined these results suggest that the semantic encoding task and perceptual match for distinctive items aid recognition memory by acting on both familiarity and recollection processes. © 2009 Elsevier B.V. All rights reserved.


              Rapid phenotypic and genotypic diversification after exposure to the oral host niche in candida albicans

              Date: 2018-07-01

              Creator: Anja Forche, Gareth Cromie, Aleeza C. Gerstein, Norma V. Solis, Tippapha, Pisithkul, Waracharee Srifa, Eric Jeffery, Darren Abbey, Scott G. Filler, Aimée M. Dudley, Judith Berman

              Access: Open access

              In vitro studies suggest that stress may generate random standing variation and that different cellular and ploidy states may evolve more rapidly under stress. Yet this idea has not been tested with pathogenic fungi growing within their host niche in vivo. Here, we analyzed the generation of both genotypic and phenotypic diversity during exposure of Candida albicans to the mouse oral cavity. Ploidy, aneuploidy, loss of heterozygosity (LOH), and recombination were determined using flow cytometry and double digest restriction site-associated DNA sequencing. Colony phenotypic changes in size and filamentous growth were evident without selection and were enriched among colonies selected for LOH of the GAL1 marker. Aneuploidy and LOH occurred on all chromosomes (Chrs), with aneuploidy more frequent for smaller Chrs and whole Chr LOH more frequent for larger Chrs. Large genome shifts in ploidy to haploidy often maintained one or more heterozygous disomic Chrs, consistent with random Chr missegregation events. Most isolates displayed several different types of genomic changes, suggesting that the oral environment rapidly generates diversity de novo. In sharp contrast, following in vitro propagation, isolates were not enriched for multiple LOH events, except in those that underwent haploidization and/or had high levels of Chr loss. The frequency of events was overall 100 times higher for C. albicans populations following in vivo passage compared with in vitro. These hyper-diverse in vivo isolates likely provide C. albicans with the ability to adapt rapidly to the diversity of stress environments it encounters inside the host.


              Bowdoin College Catalogue (1899-1900)

              Date: 1900-01-01

              Access: Open access



              Language of the Print: A Selection from the Donald H. Karshan Collection

              Date: 1968-01-01

              Creator: Richard V. West

              Access: Open access

              Exhibition organized by Bowdoin College Museum of Art. "Participating museums: Addison Gallery of American Art, Andover, Massachusetts [and other museums] ... 1968-1969."


              Colonial & Federal Portraits at Bowdoin College

              Date: 1966-01-01

              Creator: Marvin S. Sadik

              Access: Open access

              "Set in type at the Anthoensen Press ... designed by Leonard Baskin"--Colophon


              Modernism at Bowdoin: American Paintings from 1900 to 1940

              Date: 2011-01-01

              Creator: Joachim Homann

              Access: Open access

              The catalog of the exhibition includes works drawn from the collection of the Bowdoin College Museum of Art and selected paintings on loan from the Yale University Art Gallery. Exhibition held in the Boyd Gallery, Jan. 12-June 26, 2011.


              Miniature of Characterization of an <i>Arabidopsis thaliana </i>Adhesion Mutant
              Characterization of an Arabidopsis thaliana Adhesion Mutant
              This record is embargoed.
                • Embargo End Date: 2025-05-14

                Date: 2020-01-01

                Creator: Jacob Dexter-Meldrum

                Access: Embargoed



                  Bowdoin College Catalogue (1903-1904)

                  Date: 1904-01-01

                  Access: Open access



                  Requirement for the induced expression of a cell wall associated receptor kinase for survival during the pathogen response

                  Date: 1998-04-01

                  Creator: Zheng Hui He, Deze He, Bruce D. Kohorn

                  Access: Open access

                  Pathogen infection of angiosperms must rely on some interaction between the extracellular matrix (ECM) and the invading agent, and may be accompanied by signaling between the ECM and cytoplasm. An Arabidopsis cell wall associated receptor kinase (Wak1) has an amino-terminal domain that is tightly associated with the ECM, spans the plasma membrane and has a cytoplasmic protein kinase domain. Wak1 expression is induced when Arabidopsis plants are infected with pathogen, or when the pathogen response is stimulated either by exogenous salicylate (SA) or its analog 2,2-dichloroisonicotinic acid (INA). This Wak1 induction requires the positive regulator NPR1/NIM1. Thus Wak1 is a pathogen-related (PR) protein. Expression of an antisense and a dominant negative allele of Wak1 shows that induced expression of Wak1 is needed for a plant to survive if stimulated by INA. Ectopic expression of the entire Wak1, or the kinase domain alone, can provide resistance to otherwise lethal SA levels. These experiments suggest that Wak1 expression and other PR proteins are protecting plants from detrimental effects incurred during the pathogen response. These results provide a direct link between a protein kinase that could mediate signals from the ECM, to the events that are precipitated by a pathogen infection.


                  Report of the President, Bowdoin College 1925-1926

                  Date: 1926-01-01

                  Access: Open access




                  Report of the President, Bowdoin College 1935-1936

                  Date: 1936-01-01

                  Access: Open access



                  Random subgroups of Thompson's group F

                  Date: 2010-01-13

                  Creator: Sean Cleary, Murray Elder, Andrew Rechnitzer, Jennifer Taback

                  Access: Open access

                  We consider random subgroups of Thompson's group F with respect to two natural stratifications of the set of all k-generator subgroups. We find that the isomorphism classes of subgroups which occur with positive density are not the same for the two stratifications. We give the first known examples of persistent subgroups, whose isomorphism classes occur with positive density within the set of k-generator subgroups, for all sufficiently large k. Additionally, Thompson's group provides the first example of a group without a generic isomorphism class of subgroup. Elements of F are represented uniquely by reduced pairs of finite rooted binary trees. We compute the asymptotic growth rate and a generating function for the number of reduced pairs of trees, which we show is D-finite (short for differentiably finite) and not algebraic. We then use the asymptotic growth to prove our density results. © European Mathematical Society.


                  Leonard Baskin

                  Date: 1962-01-01

                  Access: Open access

                  This catalogue issued in lieu of Bulletin vol. II, no. 1 "Designed by Leonard Baskin. Set in type at the Stinehour Press and printed at the Meriden Gravure Company"--Colophon


                  Bowdoin Orient, v. 54, no. 17

                  Date: 1924-11-19

                  Access: Open access



                  Bowdoin Orient, v. 54, no. 18

                  Date: 1924-12-03

                  Access: Open access



                  Bowdoin Orient, v. 54, no. 30

                  Date: 1925-03-25

                  Access: Open access

                  The Occident


                  Bowdoin Orient, v. 54, no. 22

                  Date: 1925-01-21

                  Access: Open access



                  Bowdoin Orient, v. 32, no. 9

                  Date: 1902-07-10

                  Access: Open access

                  Anniversary Issue


                  Bowdoin Orient, v. 32, no. 23

                  Date: 1903-01-29

                  Access: Open access

                  Text


                  Bowdoin Orient, v. 34, no. 21

                  Date: 1905-01-13

                  Access: Open access

                  Text


                  Bowdoin Orient, v. 34, no. 10

                  Date: 1904-10-07

                  Access: Open access

                  Text