Showing 2091 - 2100 of 5708 Items
"We are your wives, sisters, daughters, mothers and friends:" United States' Women's Stories from the Public to the Archive Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2019-01-01
Creator: Sadie LoGerfo-Olsen
Access: Access restricted to the Bowdoin Community
Urban Modernity and Turbulent Water: Toward a Transnational History of Expansion in Northern Japan, 1866-1882 Access to this record is restricted to members of the Bowdoin community. Log in here to view.
Date: 2018-05-01
Creator: Ethan Barkalow
Access: Access restricted to the Bowdoin Community
Reflections questionnaire response by Luv Kataria on March 31, 2021
Date: 2021-01-01
Creator: Luv Kataria
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. The author is from the class of 2024.
Long-term trends in tropical fish larvae of the Hawaiian Islands revealed by DNA barcoding
Date: 2014-08-01
Creator: Jack Mitchell
Access: Open access
- DNA Barcoding is the identification of organisms through the use of a standardized portion of the genome, a concept first suggested by Hebert, et al (2003) and since developed to include standard databases and many campaigns internationally to identify and barcode all species in the world. Because DNA barcoding uses molecular data, rather than morphology, to identify organisms, it allows for the identification of organisms that are morphologically similar or have been processed to the point of unrecognizability. Barcoding has the potential to streamline and enhance conservation efforts drastically. Its "quick and easy" identification process allows better fisheries management, market regulation to ensure vendors are selling what they say they're selling (no more horsemeat burgers or dolphin sushi), and greater enforcement of regulations against the killing and selling of endangered animal products (Minhos et al., 2013). In my work this summer, I've been using DNA barcoding to examine the dynamics of a community of larval fish off the coast of Oahu through a seven-year longitudinal barcoding study. Fish larvae are very hard to identify morphologically because they lack obvious identifying characteristics. For this reason, barcoding is essential for accurately understanding the community structure of such fish. In my work, I analyze a set of sequences from the 5-prime region of the mitochondrial gene cytochrome oxidase subunit 1, widely used as a barcode in the animal kingdom, gathered from fish larvae collected off the coast of Oahu by the University of Hawaii Manoa Biology 301L class. The sampling consisted of a series of oblique plankton tows taken at three depths (5m, 25m, and 50m) between January and April every year from 2007 to 2013. During this period, a total of 833 fish larvae were sampled and sequenced. Using the Barcode of Life Data Systems (BOLD Systems) Identification Engine, I was able to identify 78% of all specimens to family-level or better, representing about 25% of the 202 families of shore fishes known to occur in Hawaiian coastal waters. The data stratification consisted of 7 years, each with three depths and 56 family groups, a 21 by 56 data matrix. In order to see the patterns of the matrix, I used Principal Components Analysis, a form of ordination, which distills multidimensional data to a form that is more easily visualized. This ordination revealed that 2009 and 2011 had highly anomalous community structure in which there were large increases in abundance (greater than three (3) Standard Deviations from the mean) of 12 family groups in each year, indicating concerted change in the structure of ichythoplankton in those years, though the families may be represented by a low number of specimens in the sample. Because these families had little to no representation in other years, we are able to rule out the possibility of results being skewed by a couple of families that showed up in our nets by chance that don't reflect the actual community structure. In these years, the highly anomalous families did not overlap, indicating that the factors causing the anomalies were non-identical. In 2009 there were eight families that deviated from the mean by over four (4) Standard Deviations, and in 2011 there were ten. Though the biggest groups of deviant families in both years were reef fish and mesopelagic fish, tropical habitat ranged from shallow water benthic (sea-bed) fish such as Ophichthidae, to bathypelagic (deep sea) fish such as the anglerfish family Ceratiidae. In my last few weeks working on this project I am exploring what environmental factors may have had a hand in such anomalies. El Niño cycles may have had a hand, as there was a weak La Niña (slightly cooler waters) anomaly leading into 2009, and a very strong La Niña (drastically cooler waters) anomaly leading into 2011 ("Cold and Warm Episodes by Season," 2014). The differences in community structure I detected had different signs, that is the co-variance of fish families was different for each of these years. This suggests that water temperature itself may not be causing these ecological patterns. A more likely hypothesis links the effects of El Niño/La Niña on oceanographic circulation throughout the Pacific and even near-shore in the Hawaiian Islands. These changes can drive differences in the delivery of larvae to the islands, as well as advection away from the islands. Further research in the remainder of the summer will attempt to gather more information on what may have caused the community structure anomalies. Final Report of research funded by Mary Lou Zeeman’s NSF grant - Computational Sustainability (NSF-CCF-0832788).
Associations Between Mode of Birth and Neuropsychological Development in Children Aged 4 Years: Results from a Birth Cohort Study
Date: 2021-12-01
Creator: Lea Takács, Samuel P. Putnam, Catherine Monk, Hannah G. Dahlen, Charlene, Thornton, František Bartoš, Anastasia Topalidou, Lilian L. Peters
Access: Open access
- The aim of this prospective longitudinal study was to examine the association between Cesarean section (CS) and child development and behavior. The sample consisted of 256 children who were born at term without serious perinatal pathologies. Their development and behavior was assessed at the age of four using Ages and Stages Questionnaire (ASQ-3), Children’s Behavior Questionnaire and Strength and Difficulties Questionnaire. Multivariate linear regression analyses were conducted to assess the association between CS and child outcomes. CS was associated with better scores in the Problem Solving domain of the ASQ in the whole sample. After stratifying by child sex, the positive association between CS and the Problem Solving domain was significant in boys, while no association was found in girls. Girls were rated less optimally in the Gross Motor domain of the ASQ when born via CS. Mode of birth was not associated with behavioral outcomes.
Evolution of pathogenicity and sexual reproduction in eight Candida genomes
Date: 2009-06-04
Creator: Geraldine Butler, Matthew D. Rasmussen, Michael F. Lin, Manuel A.S. Santos, Sharadha, Sakthikumar, Carol A. Munro, Esther Rheinbay, Manfred Grabherr, Anja Forche, Jennifer L. Reedy, Ino Agrafioti, Martha B. Arnaud, Steven Bates, Alistair J.P. Brown, Sascha Brunke, Maria C. Costanzo, David A. Fitzpatrick, Piet W.J. De Groot, David Harris, Lois L. Hoyer, Bernhard Hube, Frans M. Klis, Chinnappa Kodira, Nicola Lennard, Mary E. Logue, Ronny Martin, Aaron M. Neiman, Elissavet Nikolaou, Michael A. Quail, Janet Quinn, Maria C. Santos
Access: Open access
- Candida species are the most common cause of opportunistic fungal infection worldwide. Here we report the genome sequences of six Candida species and compare these and related pathogens and non-pathogens. There are significant expansions of cell wall, secreted and transporter gene families in pathogenic species, suggesting adaptations associated with virulence. Large genomic tracts are homozygous in three diploid species, possibly resulting from recent recombination events. Surprisingly, key components of the mating and meiosis pathways are missing from several species. These include major differences at the mating-type loci (MTL); Lodderomyces elongisporus lacks MTL, and components of the a1/α2 cell identity determinant were lost in other species, raising questions about how mating and cell types are controlled. Analysis of the CUG leucine-to-serine genetic-code change reveals that 99% of ancestral CUG codons were erased and new ones arose elsewhere. Lastly, we revise the Candida albicans gene catalogue, identifying many new genes. © 2009 Macmillan Publishers Limited. All rights reserved.
Social support buffers the effects of maternal prenatal stress on infants' unpredictability
Date: 2021-06-01
Creator: Lea Takács, Jiří Štipl, Maria Gartstein, Samuel P. Putnam, Catherine, Monk
Access: Open access
- Objective: Exposure to stress in pregnancy has been shown to affect fetal development with short- and long-term physiological and behavioral consequences for the offspring. Although social support is known to lower perceived stress, no prior study has investigated the buffering role of social support in the context of prenatal stress effects on infant temperament. The aim of this study was to examine interactive effects of prenatal stress and social support on several dimensions of infant temperament at 9 months postpartum. Study design: A total of 272 mothers completed the Perceived Stress Scale and the Perceived Social Support Scale in the 3rd trimester of pregnancy. Infant temperament was assessed by mothers at 9 months postpartum using the Infant Characteristics Questionnaire. Linear regression models were performed to assess the effects of perceived stress, social support, and their interaction on infant temperament. Results: Prenatal stress interacted with social support, such that prenatal stress increased infant unpredictability when social support was below -0.5 SD. Conclusions: Prenatal stress was found to be a risk factor for infant temperamental unpredictability when combined with low social support perceived by the mother during pregnancy. Support of others, not previously examined in this context, can reduce the impact of prenatal stress.
Eikonal methods applied to gravitational scattering amplitudes
Date: 2011-01-01
Creator: Stephen G. Naculicha, Howard J. Schnitzerb
Access: Open access
- We apply factorization and eikonal methods from gauge theories to scattering amplitudes in gravity. We hypothesize that these amplitudes factor into an IR-divergent soft function and an IR-finite hard function, with the former given by the expectation value of a product of gravitational Wilson line operators. Using this approach, we show that the IR-divergent part of the n-graviton scattering amplitude is given by the exponential of the one-loop IR divergence, as originally discovered byWeinberg, with no additional subleading IR-divergent contributions in dimensional regularization. © SISSA 2011.