University of Maryland, Baltimore County
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AND THE HAND OF THE LORD WAS WITH THEM: THE EFFECTS OF PLANTERS' SOCIOECONOMIC STATUS ON THE CAPITAL TRIALS OF ENSLAVED AFRICANS IN COLONIAL MARYLAND, 1726-1775
No full textDuring the Maryland's colonial period, African slaves were tried in county courts, courts of oyer and terminer and gaol delivery, and the provincial court in essentially the same manner as free and indentured Europeans. They were also pardoned from capital sentences at approximately the same rate as free Europeans. Since the laws were crafted by wealthy slave owners and slaves represented a substantial financial investment, I predicted that the slaves of the wealthiest, elite planters would be more likely to be pardoned for capital offenses than the slaves of non-elite planters. Statistical analysis showed this prediction to be false. Elite-owned slaves were no more likely than non-elite-owned slaves to be pardoned , and in fact were tried disproportionately to their numbers. Financial interests of owners did not appear to be an significant factor in gaining pardons for enslaved Africans. This encourages further research into why enslaved Africans were pardoned with relative frequency in a legal system designed to oppress them
Parents of Children with Food Allergy: Gender Differences in Perceived Burden, Food Allergy Severity, Psychological Distress, and Dyadic Adjustment
No full textAlthough fathers are important influences on child development, fathers are understudied in the child chronic illness literature. The limited available research presents mixed findings regarding differences in mothers' and fathers' perceptions of their child's illness. Parenting children with food allergies has been shown to negatively impact mothers, but few studies of parent adjustment to pediatric food allergy have incorporated both mothers and fathers. This study compared fathers' and mothers' perceptions of the impact and severity of their child's food allergy, their levels of involvement in illness-related care, psychological distress and dyadic adjustment. Ninety-two parents of children with food allergy (46 mother-father pairs) rated the severity of their child's food allergies and completed the Food Allergy Impact Scale, State Trait Anxiety Inventory, and Dyadic Adjustment Scale. They also reported the frequency with which they engaged in different illness-related care activities, including attending food allergy appointments, preparing meals, and planning food purchases. Mothers reported more burden than fathers for meal preparation, family social activities, and stress and free time. Mothers also reported significantly greater involvement in illness-related care. Fathers who reported more frequent appointment attendance perceived meal preparation as significantly more burdensome than fathers who were less involved. Mothers and fathers did not differ in perceived illness severity, psychological distress, or dyadic adjustment. These results suggest that fathers who are less involved may be buffered from experiencing the burden of their child's illness. Differences in involvement rather than other gender differences may explain discrepancies in mothers' and fathers' illness perceptions
African Colonization and Unionism in the South, 1817-1862
No full textIn late December of 1816, prominent citizens within the state of Virginia in conjunction with the United States government established the American Colonization Society. The initial goal of the society was to raise funds for the free black population within the United States so that they could emigrate to West Africa. This thesis demonstrates how colonization rhetoric functioned as a moderate vantage point through the polarizing debate between abolitionists from the North and proslavery politicians from the South in antebellum America. Proponents justified the program as benevolent by promoting opportunities in West Africa including commerce and the gospel of Christianity. Liberia gained independence in 1847. Passage of the Fugitive Slave Act of 1850 led to the resurgence of colonization rhetoric. Colonization proponents became Unionists in the Border South throughout the secession crisis. These Southern Unionists adhered to the notion that a confederacy would ultimately fail. Reverend Robert J. Breckenridge embodied a patriotic spirit for decades prior to the Civil War as a minister in Maryland and Kentucky. He fully supported the sovereignty of the Constitution but advocated antislavery measures such as gradual emancipation with colonization. Robert J. Breckenridge and other prominent whites did not offer allegiance to the Union with slaveholders' rights in jeopardy; yet, Southerners advanced antislavery rhetoric in terms of emancipation with colonization as a gradual process. Lincoln balancing politics on colonization and emancipation in the Civil War needed support from the Border State Unionists. In addition to this paper, a website was created encompassing three lesson plans for eighth graders so they could explore the role of moderates from the Border South. Educators in the past usually emphasize Northern and Southern aggression in terms of abolitionists versus slaveholders. Students will now examine colonization efforts between 1817-1862 and the role of Southern Unionists in the first two years of the Civil War as significant elements in American History
On Developing a System Analysis Model for Trace Gas Detection using Pulsed Laser and QEPAS
No full textThis thesis presents the development of a system analysis model for a QEPAS (Quartz Enhanced Photo Acoustic Spectroscopy)-based trace gas detection system with pulsed-laser input and sample-mean test-statistic output. For this QEPAS-based system, the input laser signal is pulsed, and its beam is centered between the tines of a quartz tuning fork placed in a gas cell. If the trace gas is present, it absorbs the energy from the beam, resulting in the generation of an acoustic pressure wave P(r, t). This pressure wave strikes the fork tines causing them to vibrate at resonant frequency. These vibrations result in the flow of current within the tines, due to the piezoelectric effect. On obtaining the current flow signal waveform in the fork, and using statistical signal processing of multiple samples of this waveform, the trace gas can be detected and its concentration estimated. This analysis model will allow one to assess the performance of such a system for various parameter values that define a given system. The project involves the generation and assessment of solutions of differential equations for the pulsed-laser generated acoustic pressure wave, the resulting tuning-fork tines vibration, and the tuning fork generated current. This work is a different, but related, approach to that of N. Petra, et al., that considered a QEPAS-based system with a continuous-wave wavelength-sinusoidal-modulated laser signal [1]
The Power of Portunhol: Bolivian Paulistano Culture in Sao Paulo, Brazil
No full textThe occurrence of Portunhol in transnational Bolivian paulistano culture stems from the linguistic need to shift from one's home culture language of Spanish to that of the host culture language of Portuguese. Through historical background data and theoretical context of existing research on Bolivian immigration to Brazil, I developed a case study on the use of Portunhol by the non-government organization (NGO) Centro do Apoio ao Imigrante (CAMI). CAMI primarily serves transnational Bolivians working in the paulistano garment industry, who traditionally lack documentation on both federal (visa) and state (work) levels. Recently, partially due to Amnesty Law n� 5.655/2009, immigrant documentation legitimacy is on the rise. I attribute this change to the use of Portunhol between CAMI and the population they serve. I use Bourdieu's theory of symbolic capital to define Portunhol as social capital acting as an integration tool for CAMI and Bolivians who regularly use the language
Fatigue and Fatigue Crack Growth Processes in Hard Tissues: The Importance of Age and Surface Integrity
No full textWith the progressive increase in partially and fully dentate seniors, fracture has become an increasingly common form of restored tooth failure. Dentin undergoes progressive changes in microstructure with patient age, and studies are now suggesting that there is a reduction in fatigue strength and fatigue crack growth resistance of this tissue. This dissertation explores aging of dentin, the influence of flaws that are introduced during restorative processes on the fatigue properties of dentin, and proposes models for characterizing the damage initiation and growth process during fatigue of dentin. Results from this investigation show that the fatigue crack growth properties (Paris Law parameters (C, m) and DeltaKth) of human dentin undergo the most significant changes at a patient age of 42 years. Based on the fatigue crack growth responses, three age groups were established including young (age ≤ 33), aged (34 ≤ age ≤ 49) and old (50 ≤ age) patients for further analysis. There were significant differences in the initiation and growth behavior between the tissues of patients from the three age groups. With regards to the influence of restorative processes, there was no influence on the quasi-static responses of dentin. However, the endurance limit of dentin treated with the dental burs (28 MPa) and abrasive air jet (35 MPa) were approximately 36% and 20% lower than that of the control (44 MPa), respectively. Both cutting processes caused a significant reduction (p≤0.0001) in fatigue strength. An accumulative damage model was developed to characterize fatigue of the control and bur treated dentin as well as provide a model for fatigue life prediction. The damage models were derived as a function of number of loading cycles (N), and ratio of applied stress to ultimate strength (r). The developed models provide estimations for the initial state of damage, the state of damage during the life, as well as the damage accumulation rate for cyclic loading of dentin. Using the experimental findings, a Damage Effect Model (DEM) was also developed to describe the influence of flaws introduced by bur treatment on fatigue of dentin. The DEM showed that the damage caused by bur treatment is uniform and independent of tubule orientation. Using the developed DEM for dentin with 0� tubule orientation, material constants of bur treated dentin with 90� orientation were estimated and used in predicting fatigue for controlled experimental conditions involving a notched fatigue approach. Overall, the results of this study provide fundamental knowledge concerning the influence of aging and cutting processes on the fatigue properties of dentin. These findings are of substantial importance to the field of restorative dentistry, and potentially establish the need for treating senior patients with an approach that is unique from that of younger patients. The damage models developed in this investigation are the first that have been developed for hard tissues, and provide a foundation for future research aimed at modeling fatigue processes in hard tissues including bone and dentin
Private Packet Filtering Searching for Sensitive Indicators without Revealing the Indicators in Collaborative Environments
No full textPrivate Packet Filtering (PPF) is a new capability that preserves the confidentiality of sensitive attack indicators, and retrieves network packets that match those indicators without revealing specific indicators or the matching packets. The capability is achieved through the introduction of a high-level language, a conjunction operator that expands the breadth of the language, a simulation of the document detection and recovery rates of the output buffer, and through a description of applicable system facets. Fundamentally, PPF adapts the private stream search system defined by Ostrovsky and Skeith which uses the (partial) homomorphic property of the Paillier cryptosystem. PPF is intended for use in a collaborative environment involving a cyber defender and a partner: The defender has access to a set of sensitive indicators, and is willing to share some of those indicators with the partner. The partner has access to network data, and is willing to share that data. Neither is willing to provide full access. Using the language, the defender creates an encrypted form of the sensitive indicators, and passes the encrypted indicators to the partner. The partner then uses the encrypted indicators to filter packets, and returns an encrypted packet capture file. The partner does not decrypt the indicators and cannot identify which packets matched. The defender decrypts, reassembles the matching packets, gains situational awareness, and notifies the partner of any packets that matched an attack indicator. In this sense, the defender reveals only the matched indicator and retains control of all other indicators. PPF allows both parties to gain situational awareness of malicious activity, and to retain control without exposing every indicator or all network data. Ostrovsky and Skeith introduced the notion of private stream searching in 2005. Their private search system is clever, uses a list of encrypted ones and zeroes to select matching documents, and an output buffer to accumulate non-matching documents as a summation of plaintext zeroes. This buffer optimizes the communication cost of the search and assures that non-matching documents are not transmitted back to client performing the performing search. Using our PPF language, a cyber defender gains access to the underlying private stream search system without significant knowledge of the system or the complexity of its cryptographic methods. The language thus provides a standard representation of a private query for packet filtering that resolves data organization issues and encourages the development of inter-operable implementations. A high level language for private stream searching has not been previously presented
Multiple Objective Task Scheduling for Scalable High Performance Computing
No full textIndividual processor frequencies have reached an upper physical and practical limit. Processor designs now involve adding multiple processing elements to a single chip to enable increased performance. It is expected that all future processor designs will have multiple cores with a focus on reducing frequencies and adding more individual processing elements (cores) while having to balance power consumption, reliability and maintain high performance. Due to the increased complexity as well as increased heterogeneity of parallel architectures, petascale and future exascale systems, with the number of processors on the order of 108-109, must incorporate more intelligent software tools that help manage parallel execution for the user. I show that by managing the parallel execution environment at runtime, we can measure performance tradeoffs for a particular application or application domain for a set of common HPC architectures. In this dissertation I provide a performance analysis of two common graph algorithms for finding a minimum spanning tree and evaluate the multicore performance of a common high performance computing (HPC) benchmark on multicore processors. I developed a novel autonomic execution model and adaptive runtime system (ARRIA) Adaptive Runtime Resource for Intensive Applications. ARRIA is designed with the intent of improving application programmability, scalability and performance while freeing the programmer from explicit message passing and thread management. Experiments are conducted that evaluate ARRIA's capabilities on data intensive applications, those where the majority of execution time is spent reading and writing either to local or remote memory locations. In my approach, I focus on developing task schedules that satisfy multiple objectives for clusters of compute nodes during runtime. This approach is novel in that it can control application performance and satisfy constraints which are solved using multi objective optimization techniques as the program runs. The development and implementation of the ARRIA runtime system and subsequent optimization criteria likely provide reasonable models for the exascale computing era. The results of this dissertation demonstrate, experimentally, that for high performance computing systems, a dynamic, task based, parallel programming environment and scheduler that provide lower total workload runtimes than state of the art static schedules
