Showing 3291 - 3300 of 5714 Items
Walter K. Gutman Collection
Date: 1966-01-01
Access: Open access
- Exhibition catalogue from Bowdoin College Museum of Art. Includes and essay by Walter Gutman.
Human protein Sam68 relocalization and interaction with poliovirus RNA polymerase in infected cells
Date: 1996-03-19
Creator: A. E. Mcbride, A. Schlegel, K. Kirkegaard
Access: Open access
- A HeLa cDNA expression library was screened for human polypeptides that interacted with the poliovirus RNA-dependent RNA polymerase, 3D, using the two-hybrid system in the yeast Saccharomyces cerevisiae. Sam68 (Src- associated in mitosis, 68 kDa) emerged as the human cDNA that, when fused to a transcriptional activation domain, gave the strongest 3D interaction signal with a LexA-3D hybrid protein. 3D polymerase and Sam68 coimmunoprecipitated from infected human cell lysates with antibodies that recognized either protein. Upon poliovirus infection. Sam68 relocalized from the nucleus to the cytoplasm, where poliovirus replication occurs. Sam68 was isolated from infected cell lysates with an antibody that recognizes poliovirus protein 2C, suggesting that it is found on poliovirus-induced membranes upon which viral RNA synthesis occurs. These data, in combination with the known RNA- and protein-binding properties of Sam68, make Sam68 a strong candidate for a host protein with a functional role in poliovirus replication.
Virtual Communities Don’t Exist: Avoiding Digital Dualism in Studying Collaboration
Date: 2013-04-12
Creator: PJ Rey, Nathan Jurgenson
Access: Open access
- Effective collaboration in communities requires information sharing. Though digital media may have certain affordances that encourage us to communicate differently than in the past, the communities these media facilitate are no less real than communities bound together by voice or text. In this paper, we argue that idea of “virtual communities” is misleading. Communities and collaboration occur not in some virtual world or a new, cyber, space, but instead they are part of one reality influenced simultaneously by materiality and the various flows of information—digital included. In light of this argument, we implore researchers to take serious the influence of digitality, and, specific to this conference, those looking primarily at digitality to take seriously the materiality, bodies, history, and politics not separate from but deeply interpenetrating the digital. The changes in community organization brought about by digital media should not be thought of or called “virtual” (e.g., “virtual teams” as opposed to real ones), but instead part of one augmented community. Presented at the Collaborative Organizations & Social Media Conference at Bowdoin College on April 12, 2013.
As Maine Goes
Date: 1966-01-01
Access: Open access
- Catalogue of an exhibition held at the Bowdoin College Museum of Art.
Projected land-use change impacts on ecosystem services in the United States
Date: 2014-05-20
Creator: Joshua J. Lawler, David J. Lewis, Erik Nelson, Andrew J. Plantinga, Stephen, Polasky, John C. Withey, David P. Helmers, Sebastián Martinuzzi, Derric Penningtonh
Access: Open access
- Providing food, timber, energy, housing, and other goods and services, while maintaining ecosystem functions and biodiversity that underpin their sustainable supply, is one of the great challenges of our time. Understanding the drivers of land-use change and how policies can alter land-use change will be critical to meeting this challenge. Here we project land-use change in the contiguous United States to 2051 under two plausible baseline trajectories of economic conditions to illustrate how differences in underlying market forces can have large impacts on land-use with cascading effects on ecosystem services and wildlife habitat. We project a large increase in croplands (28.2 million ha) under a scenario with high crop demand mirroring conditions starting in 2007, compared with a loss of cropland (11.2 million ha) mirroring conditions in the 1990s. Projected land-use changes result in increases in carbon storage, timber production, food production from increased yields, and >10% decreases in habitat for 25% of modeled species. We also analyze policy alternatives designed to encourage forest cover and natural landscapes and reduce urban expansion. Although these policy scenarios modify baseline land-use patterns, they do not reverse powerful underlying trends. Policy interventions need to be aggressive to significantly alter underlying land-use change trends and shift the trajectory of ecosystem service provision.
Gendered Subjectivity in Refugee Resettlement Processes: From Somalia to Lewiston, ME
Date: 2018-01-01
Creator: Elena Gleed
Access: Open access
- Refugee Resettlement to the United States is a globalized and transnational process of making home. After Somali state collapse in 1991, more than a million displaced people fled to refugee camps across the Kenyan border. Today, over 12,000 Somali people now live in Lewiston, ME, an old mill town located along the Androscoggin River. As refugees are resettled by the United Nations High Commissioner for Refugees they enter a system created over fifty years ago in response to World War II. Using post-colonial and feminist scholarship, this project analyses the “female refugee” subject as she appears in the official discourse of resettlement processes. I trace the historical emergence of this subjectivity from an individual and work-based neoliberal American ethos to non-governmental organizations run by Somali women in Lewiston. Drawing from document analysis and ethnographic interviews, this paper explores the how Somali women are made to be “new American workers” in a process that combines western liberal feminism with ideas of integration and cultural orientation to the United States.
Using 'big data' to explain visits to lakes in 17 US states
Date: 2020-07-01
Creator: Erik Nelson, Maggie Rogers, Spencer Wood, Jesse Chung, Bonnie, Keeler
Access: Open access
- We use large dataset on US lakes from 17 states to estimate the relationship between summertime visits to lakes as proxied by social media use and the lakes' water quality, amenities, and surrounding landscape features and socioeconomic conditions. Prior to estimating these relationships we worked on 1) selecting a parsimonious set of explanatory variables from a roster of more than 100 lake attributes and 2) accounting for the non-random pattern of missing water quality data. These steps 1) improved the interpretability of the estimated visit models and 2) widened our estimated models' scope of statistical inference. We used Machine Learning techniques to select parsimonious sets of explanatory variables and multiple imputation to estimate water quality at lakes missing this data. We found the following relationships between summertime visits to lake and their attributes across the 17-state region. First, we estimated that every additional meter of average summer-time Secchi depth between 1995 and 2014 was associated with at least 7.0% more summer-time visits to a lake between 2005 to 2014, all else equal. Second, we consistently found that lake amenities, such as beaches, boat launches, and public toilets, were more powerful predictors of visits than water quality. Third, we also found that visits to a lake were strongly influenced by the lake's accessibility and its distance to nearby lakes and the amenities the nearby lakes offered. Finally, our results highlight the biased results that "big data"-based research on recreation can generate if non-random missing observation patterns in the data are not corrected.
Contingent planning under uncertainty via stochastic satisfiability
Date: 2003-07-01
Creator: Stephen M. Majercik, Michael L. Littman
Access: Open access
- We describe a new planning technique that efficiently solves probabilistic propositional contingent planning problems by converting them into instances of stochastic satisfiability (SSAT) and solving these problems instead. We make fundamental contributions in two areas: the solution of SSAT problems and the solution of stochastic planning problems. This is the first work extending the planning-as-satisfiability paradigm to stochastic domains. Our planner, ZANDER, can solve arbitrary, goal-oriented, finite-horizon partially observable Markov decision processes (POMDPs). An empirical study comparing ZANDER to seven other leading planners shows that its performance is competitive on a range of problems. © 2003 Elsevier Science B.V. All rights reserved.