Showing 131 - 140 of 5709 Items
Civil Society under the Law ‘On Foreign Agents’: NGO Strategies and Network Transformation
Date: 2018-04-21
Creator: Maria Tysiachniouk, Svetlana Tulaeva, Laura A. Henry
Access: Open access
- This essay analyses how the ‘foreign agent’ law has been interpreted and implemented by the Russian authorities and examines diverse NGO survival strategies in response to the ‘foreign agent’ label. The foreign agent law has disrupted and transformed resource mobilisation strategies and transnational NGO networks. Based on qualitative research on environmental NGOs, we offer a typology of NGO responses to the foreign agent law, providing examples to show how the organisations attempt to ensure their survival.
Mechanisms underlying variable responses to isoforms of the neuropeptide C-type allatostatin (AST-C) in the cardiac neuromuscular system of the American lobster, Homarus americanus
Date: 2019-01-01
Creator: Evalyn Mackenzie
Access: Open access
- Central Pattern Generators (CPGs) are neural networks that produce steady, rhythmic patterned outputs that activate particular muscles and consequently create recurrent rhythmic movements. The cardiac ganglion (CG) of the American lobster (Homarus americanus) is a useful model system for the study of CPGs. Neuropeptides modulate cardiac contractions driven by the CG in H. americanus and accordingly elicit a range of effects. Post-translational modifications such as amidation can impact function of a peptide neuromodulator. C-type allatostatins (AST-Cs) are a group of neuropeptides that modulate the cardiac neuromuscular system of H. americanus. The objective of this study was to determine what structural aspects of the peptides were responsible for the similarity in responses elicited by AST-C I and AST-C III and the difference in responses evoked by AST-C II in comparison. AST-C I and AST-C III are not C-terminally amidated, whereas AST-C II is C-terminally amidated. We first hypothesized that amidated AST-C peptides would evoke similar responses to one another in contraction amplitude and frequency. Our second hypothesis was that exchanging the amino acids alanine and tyrosine at a specific location in AST-C II and AST-C III would affect the conformation of the peptide, and consequently impact peptide binding and elicit different effects. In contrast to our predictions, we did not see similar responses evoked by all amidated or all non-amidated peptides among lobsters. In support of our second hypothesis, there was a significant difference in percent change in contraction amplitude elicited among AST-C II Y, AST-C II and AST-C III.
Ernest Haskell (1876-1925): A Retrospective Exhibition: A Portfolio of Selected Work
Date: 1976-01-01
Creator: Ruth Fine, Russell J. Moore
Access: Open access
- "Composition and printing by The Anthoensen Press, Portland, Maine."
Bowdoin College - Medical School of Maine Catalogue (1878-1879)
Date: 1879-01-01
Access: Open access
Two modes of transvection at the eyes absent gene of Drosophila demonstrate plasticity in transcriptional regulatory interactions in cis and in trans
Date: 2019-01-01
Creator: Katherine Tian, Rachel E. Henderson, Reyna Parker, Alexia Brown, Justine E., Johnson, Jack R. Bateman
Access: Open access
- For many genes, proper gene expression requires coordinated and dynamic interactions between multiple regulatory elements, each of which can either promote or silence transcription. In Drosophila, the complexity of the regulatory landscape is further complicated by the tight physical pairing of homologous chromosomes, which can permit regulatory elements to interact in trans, a phenomenon known as transvection. To better understand how gene expression can be programmed through cis- and trans-regulatory interactions, we analyzed transvection effects for a collection of alleles of the eyes absent (eya) gene. We find that trans-activation of a promoter by the eya eye-specific enhancers is broadly supported in many allelic backgrounds, and that the availability of an enhancer to act in trans can be predicted based on the molecular lesion of an eya allele. Furthermore, by manipulating promoter availability in cis and in trans, we demonstrate that the eye-specific enhancers of eya show plasticity in their promoter preference between two different transcriptional start sites, which depends on promoter competition between the two potential targets. Finally, we show that certain alleles of eya demonstrate pairing-sensitive silencing resulting from trans-interactions between Polycomb Response Elements (PREs), and genetic and genomic data support a general role for PcG proteins in mediating transcriptional silencing at eya. Overall, our data highlight how eya gene regulation relies upon a complex but plastic interplay between multiple enhancers, promoters, and PREs.
Economic-based projections of future land use in the conterminous United States under alternative policy scenarios
Date: 2012-04-01
Creator: V. C. Radeloff, E. Nelson, A. J. Plantinga, D. J. Lewis, D., Helmers, J. J. Lawler, J. C. Withey, F. Beaudry, S. Martinuzzi
Access: Open access
- Land-use change significantly contributes to biodiversity loss, invasive species spread, changes in biogeochemical cycles, and the loss of ecosystem services. Planning for a sustainable future requires a thorough understanding of expected land use at the fine spatial scales relevant for modeling many ecological processes and at dimensions appropriate for regional or national-level policy making. Our goal was to construct and parameterize an econometric model of land-use change to project future land use to the year 2051 at a fine spatial scale across the conterminous United States under several alternative land-use policy scenarios. We parameterized the econometric model of land-use change with the National Resource Inventory (NRI) 1992 and 1997 land-use data for 844 000 sample points. Land-use transitions were estimated for five land-use classes (cropland, pasture, range, forest, and urban). We predicted land-use change under four scenarios: business-as-usual, afforestation, removal of agricultural subsidies, and increased urban rents. Our results for the business-as-usual scenario showed widespread changes in land use, affecting 36% of the land area of the conterminous United States, with large increases in urban land (79%) and forest (7%), and declines in cropland (\-16%) and pasture (\-13%). Areas with particularly high rates of land-use change included the larger Chicago area, parts of the Pacific Northwest, and the Central Valley of California. However, while land-use change was substantial, differences in results among the four scenarios were relatively minor. The only scenario that was markedly different was the afforestation scenario, which resulted in an increase of forest area that was twice as high as the business-as-usual scenario. Land-use policies can affect trends, but only so much. The basic economic and demographic factors shaping land-use changes in the United States are powerful, and even fairly dramatic policy changes, showed only moderate deviations from the business-as-usual scenario. Given the magnitude of predicted land-use change, any attempts to identify a sustainable future or to predict the effects of climate change will have to take likely land-use changes into account. Econometric models that can simulate land-use change for broad areas with fine resolution are necessary to predict trends in ecosystem service provision and biodiversity persistence. © 2012 by the Ecological Society of America.
Recent Work of David Driskell: Paintings and Prints
Date: 1973-01-01
Access: Open access
- Exhibition held August 17-September 20, 1973 in The Boyd Art Gallery, Bowdoin College Museum of Art, Brunswick, Maine.
Reflections questionnaire response by Anonymous on April 1, 2021
Date: 2021-01-01
Creator: Anonymous
Access: Open access
- This is a response to the Documenting Bowdoin & COVID-19 Reflections Questionnaire. The questionnaire was created in March 2021 by staff of Bowdoin's George J. Mitchell Department of Special Collections & Archives. Author is class of 2024.
Treasures from Near Eastern Looms
Date: 1981-01-01
Creator: Ernest H. Roberts
Access: Open access
- The exhibition and catalogue held at Bowdoin College Museum of Art, Brunswick, Me., Sept. 11, 1981 to Nov. 22, 1981 and The Textile Museum, Washington, D.C., Dec. 11, 1981 to Feb. 6, 1982 Photographs by Robert H. Stillwell.
Next-to-soft corrections to high energy scattering in QCD and gravity
Date: 2017-01-01
Creator: A. Luna, S. Melville, S. G. Naculich, C. D. White
Access: Open access
- We examine the Regge (high energy) limit of 4-point scattering in both QCD and gravity, using recently developed techniques to systematically compute all corrections up to next-to-leading power in the exchanged momentum i.e. beyond the eikonal approximation. We consider the situation of two scalar particles of arbitrary mass, thus generalising previous calculations in the literature. In QCD, our calculation describes power-suppressed corrections to the Reggeisation of the gluon. In gravity, we confirm a previous conjecture that next-to-soft corrections correspond to two independent deflection angles for the incoming particles. Our calculations in QCD and gravity are consistent with the well-known double copy relating amplitudes in the two theories.