Showing 41 - 50 of 5709 Items
Individual differences in EEG correlates of recognition memory due to DAT polymorphisms
Date: 2017-12-01
Creator: Paolo Medrano, Erika Nyhus, Andrew Smolen, Tim Curran, Robert S., Ross
Access: Open access
- Introduction: Although previous research suggests that genetic variation in dopaminergic genes may affect recognition memory, the role dopamine transporter expression may have on the behavioral and EEG correlates of recognition memory has not been well established. Objectives: The study aims to reveal how individual differences in dopaminergic functioning due to genetic variations in the dopamine transporter gene influences behavioral and EEG correlates of recognition memory. Methods: Fifty-eight participants performed an item recognition task. Participants were asked to retrieve 200 previously presented words while brain activity was recorded with EEG. Regions of interest were established in scalp locations associated with recognition memory. Mean ERP amplitudes and event-related spectral perturbations when correctly remembering old items (hits) and recognizing new items (correct rejections) were compared as a function of dopamine transporter group. Results: Participants in the dopamine transporter group that codes for increased dopamine transporter expression (10/10 homozygotes) display slower reaction times compared to participants in the dopamine transporter group associated with the expression of fewer dopamine transporters (9R-carriers). 10/10 homozygotes further displayed differences in ERP and oscillatory activity compared to 9R-carriers. 10/10 homozygotes fail to display the left parietal old/new effect, an ERP signature of recognition memory associated with the amount of information retrieved. 10/10 homozygotes also displayed greater decreases of alpha and beta oscillatory activity during item memory retrieval compared to 9R-carriers. Conclusion: Compared to 9R-carriers, 10/10 homozygotes display slower hit and correct rejection reaction times, an absence of the left parietal old/new effect, and greater decreases in alpha and beta oscillatory activity during recognition memory. These results suggest that dopamine transporter polymorphisms influence recognition memory.
Medieval Sculptor
Date: 1971-01-01
Creator: Brooks W. Stoddard
Access: Open access
- Exhibition catalogue, Bowdoin College Museum of Art.
Atmospheric potential oxygen: New observations and their implications for some atmospheric and oceanic models
Date: 2006-03-01
Creator: Mark Battle, Sara Mikaloff Fletcher, Michael L. Bender, Ralph F. Keeling, Andrew C., Manning, Nicolas Gruber, Pieter P. Tans, Melissa B. Hendricks, David T. Ho, Caroline Simonds, Robert Mika, Bill Paplawsky
Access: Open access
- Measurements of atmospheric O2/N2 ratios and CO2 concentrations can be combined into a tracer known as atmospheric potential oxygen (APO ≈ O2/N2 + CO2) that is conservative with respect to terrestrial biological activity. Consequently, APO reflects primarily ocean biogeochemistry and atmospheric circulation. Building on the work of Stephens et al. (1998), we present a set of APO observations for the years 1996-2003 with unprecedented spatial coverage. Combining data from the Princeton and Scripps air sampling programs, the data set includes new observations collected from ships in the low-latitude Pacific. The data show a smaller interhemispheric APO gradient than was observed in past studies, and different structure within the hemispheres. These differences appear to be due primarily to real changes in the APO field over time. The data also show a significant maximum in APO near the equator. Following the approach of Gruber et al. (2001), we compare these observations with predictions of APO generated from ocean O2 and CO2 flux fields and forward models of atmospheric transport. Our model predictions differ from those of earlier modeling studies, reflecting primarily the choice of atmospheric transport model (TM3 in this study). The model predictions show generally good agreement with the observations, matching the size of the interhemispheric gradient, the approximate amplitude and extent of the equatorial maximum, and the amplitude and phasing of the seasonal APO cycle at most stations. Room for improvement remains. The agreement in the interhemispheric gradient appears to be coincidental; over the last decade, the true APO gradient has evolved to a value that is consistent with our time-independent model. In addition, the equatorial maximum is somewhat more pronounced in the data than the model. This may be due to overly vigorous model transport, or insufficient spatial resolution in the air-sea fluxes used in our modeling effort. Finally, the seasonal cycles predicted by the model of atmospheric transport show evidence of an excessive seasonal rectifier in the Aleutian Islands and smaller problems elsewhere. Copyright 2006 by the American Geophysical Union.
Bowdoin College Catalogue (1906-1907)
Date: 1907-01-01
Access: Open access
- Bowdoin College Bulletin no. 9
Matrix model approach to the N = 2 U (N) gauge theory with matter in the fundamental representation
Date: 2003-01-01
Creator: Stephen G. Naculich, Howard J. Schnitzer, Niclas Wyllard
Access: Open access
- We use matrix model technology to study the N = 2 U (N) gauge theory with Nf massive hypennultiplets in the fundamental representation. We perform a completely perturbative calculation of the periods ai and the prepotential F(a) up to the first instanton level, finding agreement with previous results in the literature. We also derive the Seiberg-Witten curve and differential from the large-M solution of the matrix model. We show that the two cases Nf < N and N ≤ Nf < 2N can be treated simultaneously. © SISSA/ISAS 2003.
Bowdoin College Catalogue (1957-1958)
Date: 1958-01-01
Access: Open access
- Bowdoin College Bulletin no. 326
An Alternative Perspective on Special Purpose Acquisition Companies (SPACs): Underpricing in the “No Target" Phase
Date: 2023-01-01
Creator: Anna G Constantine
Access: Open access
- Special Purpose Acquisition Companies marked a restructuring of the often-fraudulent 1980s blank check company, an entity gathering funds to merge or acquire another business entity. Based on the Special Purpose Acquisition Company structure, “the stock price should be greater than or equal to the pro-rata trust value, discounted from the SPAC’s expiration date, at all times prior to the shareholder vote date.” In this study, I research the “no target” phase of the Special Purpose Acquisition Company’s lifecycle to evaluate whether there is a difference between their trust value and their market capitalization. Based on previous research, we know that there is a discount to trust value prior to 2009; however, I postulate the decoupling of the SPAC merger approval vote and the vote for investors to redeem may eliminate this discount. Using a first difference regression to establish the premium to the average trust value of 1,057 Special Purpose Acquisition Companies traded between 2005 and 2022, we find that both the period before 2010 and after 2010 trades at a negative premium, or discount. Because the decoupling of the merger vote and the redemption vote did not eliminate the negative premium to trust value, I postulate that the structure of SPAC redemptions, modeled as a call option with decaying time value, may be responsible for this mispricing. I also draw opportunities for future research to investigate if the embedding of a call option into the SPAC redemption structure discourages shareholders from desiring merger outcomes early in the SPAC lifecycle.
Determining the influence of proximal Zeste binding sites and promoters on rates of transvection This record is embargoed.
- Embargo End Date: 2026-05-17
Date: 2023-01-01
Creator: Molly Henderson
Access: Embargoed
Metabolic Glycan Labeling in Bacteria Using Rare Azido L-sugars Access to this record is restricted to members of the Bowdoin community. Log in here to view.
- Restriction End Date: 2027-06-01
Date: 2022-01-01
Creator: Phuong Luong
Access: Access restricted to the Bowdoin Community