Showing 411 - 420 of 681 Items
Is Prompt Engineering Effective Enough? Why ChatGPT’s Bias Needs More Than a Quick Band-Aid Fix
Date: 2025-01-01
Creator: Hamda Abdirahman Hussein, Fatima K Kunjo
Access: Open access
Multi-scale effects of environmental stress on Pinus ponderosa Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2025-01-01
Creator: Cara Sydney Nova Fields
Access: Access restricted to the Bowdoin Community
Shining a light on antimicrobial peptide pore formation: Developing a method to study alamethicin pore dynamics with polarized ATR-FTIR Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2025-01-01
Creator: Rhys Edwards
Access: Access restricted to the Bowdoin Community
QE1 vs. Abenomics: A Channel-Based Comparison of Japan’s Quantitative Easing Attempts
Date: 2025-01-01
Creator: Sujan Garapati
Access: Open access
- Since 2001, Japan has experienced two extended quantitative easing (QE) periods that aimed to address its low growth and deflationary environment. This paper investigates the transmission channels of the country’s QE policies during both periods: QE1 and Abenomics. Investigating three primary QE channels, signaling, inflation, and safety, the analysis identifies a signaling channel with different characteristics during both periods, no inflation channel, and a safety channel with different strengths during both periods. During QE1, event dates signaled low yields on short- and medium-term bonds but not on long-term bonds, suggesting a weak signaling channel. In contrast, under Abenomics, the signaling channel was strong for long-term bonds, reflecting a credible commitment to sustained low interest rates. Event dates in both periods were associated with deflation, so the evidence does not support the presence of an inflation channel. Across both periods, a significant safety channel was present. Investors paid a premium for safe assets that decreased yields as the BOJ purchased bonds, especially during Abenomics. The findings suggest that Abenomics was more successful at decreasing interest rates than QE1. Overall, this paper reveals that QE can effectively lower yields through signaling and safety effects but fails to raise inflation expectations in Japan.
Developing an Exogenous Expression System
for the Purification and Isolation of srGAP1 Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2025-01-01
Creator: Philip Spyrou
Access: Access restricted to the Bowdoin Community
Investigating the role of calcium-activated potassium channels in the stabilization of mammalian spinal locomotor activity Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2025-01-01
Creator: Aeri Ko
Access: Access restricted to the Bowdoin Community
Writing Into Openness: Coincidence, the Ethics of Narration, and Patience in the Work of W.G. Sebald
Date: 2025-01-01
Creator: Miles Berry
Access: Open access
Cell Adhesion in Arabidopsis thaliana Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2019-05-01
Creator: Natasha Ann Belsky
Access: Access restricted to the Bowdoin Community
Effects of Alkalinity and Ocean Acidification on Clam Shell Development in Phippsburg, ME
Date: 2014-08-01
Creator: Bailey Moritz
Access: Open access
- With increased CO2 in the atmosphere from the burning of fossil fuels, more is absorbed into the surface ocean, causing a reaction that leads to lower pH. This process is known as ocean acidification, which has raised global concern. Over the past decade, the clam flat near Head Beach in Phippsburg has been reduced to approximately a sixth of its former productive area. The town of Phippsburg allots money every spring to seed the clam flat with juvenile soft-shell clams (Mya arenaria) in order to support the local clamming economy, but the clams are no longer growing in much of the mud flat. A possible explanation for this loss is acidification. In order to understand if ocean acidification is the cause, I collected water samples from the mud to test for alkalinity along a transect of 5 sites spanning productive and non-productive areas of the flat. Alkalinity is a measurement of the waters ability to buffer pH changes. Lower alkalinity could mean that clams would have more difficulty forming their calcium carbonate shells due to dissolution in low pH waters. Combined with the pH measurements gathered by my peer, Lloyd Anderson ‘16, we were able to calculate aragonite saturation state. Water with a saturation state below 1 is capable of dissolving calcium carbonate (aragonite) shells. A large portion of this research project was figuring out the best methodology to use for collecting data on the clam flat. The tested water needs to represent that which the clams are actually using while they are embedded in the mud. Additionally, juvenile clams only live in the upper centimeter or so of sediment. We followed methodologies used in past studies in Maine (Green et al 2013). Three pore water samples from each site were extracted and brought back to the lab to be filtered on 7 separate days throughout July. We began sampling 2 hours prior to low tide. I determined alkalinity using an automated titration system. Average alkalinity ranged from 2200-2500 μeq/kg. The results indicated that there was not a significant difference or pattern in alkalinity or saturation state between productive and unproductive areas of the clam flat (Fig. 1). Error bars in the figure represent variability at each site over the entire study period, while analytical reproducibility was ± 9.04 μeq/L. Large changes were observed merely from one day to another. Coastal ecosystems are complex and variations such as time of day, temperature, or productivity may have influences on the porewater characteristics (Duarte 2013). While ocean acidification does not appear to be the primary driving force behind the clams’ decline at this location, the saturation state was consistently quite low ( Final Report of research funded by the Rusack Coastal Studies Fellowship.
Investigating the Effects of Climatic Change and Fire Dynamics on Peatland Carbon Accumulation in Coastal Labrador, Canada
Date: 2014-08-01
Creator: Anna Hall
Access: Open access
- High-latitude peatlands store a large stock of carbon in accumulated belowground biomass, estimated at 500 ± 100 Gt C (Yu 2012). For comparison, the atmospheric C pool is estimated at about 775 Gt (IPCC 2007) making the peatland carbon pool a potentially significant player in the global carbon cycle. Peatland carbon storage is controlled by a balance between plant productivity and decomposition, with plant matter produced during the summer months accumulating from year to year rather than fully decomposing. Peatlands are sensitive to changes in climatic regime and have the potential to shift from a net sink of atmospheric C to a net source of C with future disturbance by climate warming (Yu 2012).There are two major predictions as to how climate change could affect peatland C accumulation. Warmer temperatures could cause faster decomposition of plant biomass and lead to C release to the atmosphere and a positive feedback effect on climate change (Schuur et al. 2008). If this is the case, current warming trends suggest that peatlands could release up to 100 Gt C to the atmosphere by the year 2100 (Davidson and Janssens 2006). Alternatively, warmer summer temperatures and a longer growing season could lead to faster peat production and therefore CO2 drawdown from the atmosphere, somewhat mitigating the effects of climate change (Schuur et al. 2008). A detailed study of past C accumulation rates over a known historical warm period gives insight into how peatlands may respond to future climate warming. This project focuses on C accumulation in peatlands in Labrador, Canada, over the past 8,000 years. Because Canadian peatlands store approximately 150 Gt C, approximately 1/3 of the global peatland carbon pool, it is important to understand how the dynamics of these peatlands could be affected by present and future climate warming (Tarnocai 2006). However, the majority of research has focused on central Canada, leaving significant knowledge gaps surrounding coastal Eastern Canada (vanBellen et al. 2012). Particular emphasis in this study was given to the Holocene Thermal Maximum (HTM) which occurred from 4-6 thousand years ago in Labrador, when summer temperatures were 0.5 – 1°C warmer than at present (Kerwin et al. 2004). This study also attempts to determine the effect of fires on rates of C storage in these peatlands. Lightning-ignited peat fires have the potential to consume stored biomass and release significant CO2 to the atmosphere (Tarnocai 2006). Six peat cores (out of a total of 14 collected in Labrador in 2013) were used for this study. Throughout the following year, calibrated radiocarbon dates, bulk density, and percent carbon were used to calculate carbon accumulation rates. This summer, areal charcoal concentration (a measure of macroscopic charcoal used as a proxy for fire severity) was used to determine the influence of fires in this region. From 8,000 years ago to the present, rates of C accumulation averaged 23.1 ± 6.7 gC m-2 yr-1. Accumulation rates were highest during the HTM, averaging 29.6 ± 2.4 g C m-2 yr-1. Samples containing macroscopic charcoal had an average concentration of 0.62 mm2 cm-3 with a maximum concentration found of 3.51 mm2 cm-3. These consistently low charcoal concentrations indicate that fire was neither common nor severe in Labrador peatlands. While Kuhry (1994) and Payette et al. (2012) found that fires in Canada occurred twice as frequently during the HTM than at present, no trends in fire severity were found in these cores, and there was no evidence that fires had a significant influence on C accumulation. Therefore, the C accumulation trend we see in Labrador is not controlled by fire and is likely either a direct result of temperature variation or of vegetational and hydrological shifts caused by changes in climate. This work supports a growing body of evidence from high latitude peatlands suggesting that future warming conditions could lead to increased soil C sequestration. Final Report of research funded by the Freedman Coastal Studies Fellowship.