The Property of the Nation : Democracy and the Memory of George Washington, 1799-1865

This dissertation explores how Americans personally experienced George Washington’s legacy in the nineteenth century through visits to his estate and tomb at Mount Vernon. By the 1820s many Americans had conflicting memories of the American Revolution and its most iconic figure, George Washington. As America grew more divided, so too did the memory of Washington. On multiple occasions, government factions and organizations attempted to claim his remains for political reasons. At the same time, Americans and foreign travelers journeyed to Mount Vernon to experience his tomb and forge a deeper personal connection with the man. These visitors collected objects such as sticks, stones, and flowers from his gravesite, mementoes that not only represented their visits but also served as a reminder of a nostalgic American past. African slaves, free blacks, and European gardeners greeted these visitors as the first historical interpreters of Washington history. These individuals not only shared anecdotes but they also wove themselves into the narrative to profit from their affiliation with Washington. The history of Washington’s tomb therefore illuminates the origins of an American celebrity culture, one that elevated Washington in significance and also ultimately transformed him into a democratic figure

Virtually Standing Up or Standing By? Correlates of Enacting Social Control Online

Research has consistently established the robustness of the bystander effect, or the tendency of individuals to not intervene on behalf of others in emergency situations. This study examines the bystander effect in an online setting, focusing on factors that lead individuals to intervene, and therefore enact informal social control, on behalf of others who are being targeted by hate material. To address this question, we use an online survey (N=647) of youth and young adults recruited from a demographically balanced sample of Americans. Results demonstrate that the enactment of social control is positively affected by the existence of strong offline and online social bonds, collective efficacy, prior victimization, self-esteem, and an aversion for the hate material in question. Additionally, the amount of time that individuals spend online affects their likelihood of intervention. These findings provide important insights into the processes that underlie informal social control and begin to bridge the gap in knowledge between social control in the physical and virtual realms

Information marginalization among young adult gay and bisexual men seeking mental healthcare

Research Aims. Gay and bisexual men are underserved in mental health care with disparities in meeting mental healthcare needs compared to straight men. This study seeks to understand the mental health information behaviours and practices of young adult gay and bisexual men. Significance. By examining how information marginalization occurs within this context, we can explore ways that socio-technical processes place young adult gay and bisexual men in information margins. Methods, results, and discussion. Semi-structured interviews were conducted with 6 individuals to understand their experiences searching for mental health care. There are similarities to what we already know about information marginalization, including lack of access to information, lack of trustworthy information sources, information being withheld, overload and satisficing, income inequality, and diversity. However, there are also differences such as the way satisficing occurs, secrecy, homophily, and the need to build trust with the provider. Recommendations. Information systems must increase the visibility of relevant information to young gay and bisexual men. Conclusions. This study begins to highlight the similarities and differences within this unique population to the theory of information marginalization and demonstrates its potential transferability.Peer Reviewe

Compton Scattering in Ultra-Strong Magnetic Fields: Numerical and Analytical Behavior in the Relativistic Regime

This paper explores the effects of strong magnetic fields on the Compton scattering of relativistic electrons. Recent studies of upscattering and energy loss by relativistic electrons that have used the non-relativistic, magnetic Thomson cross section for resonant scattering or the Klein-Nishina cross section for non-resonant scattering do not account for the relativistic quantum effects of strong fields ($> 4 \times 10^{12}$ G). We have derived a simplified expression for the exact QED scattering cross section for the broadly-applicable case where relativistic electrons move along the magnetic field. To facilitate applications to astrophysical models, we have also developed compact approximate expressions for both the differential and total polarization-dependent cross sections, with the latter representing well the exact total QED cross section even at the high fields believed to be present in environments near the stellar surfaces of Soft Gamma-Ray Repeaters and Anomalous X-Ray Pulsars. We find that strong magnetic fields significantly lower the Compton scattering cross section below and at the resonance, when the incident photon energy exceeds $m_ec^2$ in the electron rest frame. The cross section is strongly dependent on the polarization of the final scattered photon. Below the cyclotron fundamental, mostly photons of perpendicular polarization are produced in scatterings, a situation that also arises above this resonance for sub-critical fields. However, an interesting discovery is that for super-critical fields, a preponderance of photons of parallel polarization results from scatterings above the cyclotron fundamental. This characteristic is both a relativistic and magnetic effect not present in the Thomson or Klein-Nishina limits.Comment: AASTeX format, 31 pages included 7 embedded figures, accepted for publication in The Astrophysical Journa

Detection limits of organic compounds achievable with intense, short-pulse lasers

Many organic molecules have strong absorption bands which can be accessed by ultraviolet short pulse lasers to produce efficient ionization. This resonant multiphoton ionization scheme has already been exploited as an ionization source in time-of-flight mass spectrometers used for environmental trace analysis. In the present work we quantify the ultimate potential of this technique by measuring absolute ion yields produced from the interaction of 267 nm femtosecond laser pulses with the organic molecules indole and toluene, and gases Xe, N2 and O2. Using multiphoton ionization cross sections extracted from these results, we show that the laser pulse parameters required for real-time detection of aromatic molecules at concentrations of one part per trillion in air and a limit of detection of a few attomoles are achievable with presently available commercial laser systems. The potential applications for the analysis of human breath, blood and tissue samples are discussed

Search for optimal distance spectrum convolutional codes

In order to communicate reliably and to reduce the required transmitter power, NASA uses coded communication systems on most of their deep space satellites and probes (e.g. Pioneer, Voyager, Galileo, and the TDRSS network). These communication systems use binary convolutional codes. Better codes make the system more reliable and require less transmitter power. However, there are no good construction techniques for convolutional codes. Thus, to find good convolutional codes requires an exhaustive search over the ensemble of all possible codes. In this paper, an efficient convolutional code search algorithm was implemented on an IBM RS6000 Model 580. The combination of algorithm efficiency and computational power enabled us to find, for the first time, the optimal rate 1/2, memory 14, convolutional code

Maternal infection and risk of intrapartum death: a population based observational study in South Asia.

BACKGROUND: Approximately 1.2 million stillbirths occur in the intrapartum period, and a further 717,000 annual neonatal deaths are caused by intrapartum events, most of which occur in resource poor settings. We aim to test the 'double-hit' hypothesis that maternal infection in the perinatal period predisposes to neurodevelopmental sequelae from an intrapartum asphyxia insult, increasing the likelihood of an early neonatal death compared with asphyxia alone. This is an observational study of singleton newborn infants with signs of intrapartum asphyxia that uses data from three previously conducted cluster randomized controlled trials taking place in rural Bangladesh and India. METHODS: From a population of 81,778 births in 54 community clusters in rural Bangladesh and India, we applied mixed effects logistic regression to data on 3890 singleton infants who had signs of intrapartum asphyxia, of whom 769 (20%) died in the early neonatal period. Poor infant condition at five minutes post-delivery was our proxy measure of intrapartum asphyxia. We had data for two markers of maternal infection: fever up to three days prior to labour, and prolonged rupture of membranes (PROM). Cause-specific verbal autopsy data were used to validate our findings using previously mentioned mixed effect logistic regression methods and the outcome of a neonatal death due to intrapartum asphyxia. RESULTS: Signs of maternal infection as indicated by PROM, combined with intrapartum asphyxia, increased the risk of an early neonatal death relative to intrapartum asphyxia alone (adjusted odds ratio (AOR) 1.28, 95% CI 1.03 - 1.59). Results from cause-specific verbal autopsy data verified our findings where there was a significantly increased odds of a early neonatal death due to intrapartum asphyxia in newborns exposed to both PROM and intrapartum asphyxia (AOR: 1.52, 95% CI 1.15 - 2.02). CONCLUSIONS: Our data support the double-hit hypothesis for signs of maternal infection as indicated by PROM. Interventions for pregnant women with signs of infection, to prevent early neonatal deaths and disability due to asphyxia, should be investigated further in resource-poor populations where the chances of maternal infection are high