University of Maryland, Baltimore County
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In Great Danger of Perishing Through Poverty: Community and Public Relief in Somerset County, Maryland, 1666-1742
No full textThis thesis explores the poor relief system in Somerset County, Maryland, between 1666 and 1742. By utilizing public relief petitions to the court, I attempt to place Somerset's poor into the larger context of poverty in colonial Maryland and early America. I examine how community and public relief created a loose and makeshift system of monetary or material aid that supported some of the poor when necessary. This thesis reveals that private family relief in the 1700s grew as a means to assist the poor in conjunction with community and public relief. I assert that an exploration of Somerset's public relief petitions may shed light on the importance of community relief in early America. In this thesis, it is evident that free blacks and those of mixed race occasionally received public relief. Additionally, I contend that, in the 1700s, the court started to give permanent tax relief to individuals who demonstrated remarkable need and permanent tax subsidies on slaves for slaveholders depending on the severity of slaves' conditions. This thesis reveals that the court began boarding the poor with householders as a way to transfer the obligation of relief to residents, often with compensation. Furthermore, I show that poor men and women sought business licenses for informal taverns and inns as a means to supplement their meager incomes. Finally, I argue that, primarily because of the growing native-born population, aid among family members, or private family relief, became a growing feature of Somerset's poor relief system
Text and Ontology Driven Clinical Decision Support System
No full textVast amounts of information are present in unstructured format in physicians' notes. Text processing techniques can be used to extract clinically relevant entities from such data. The extracted entities can then be mapped to concepts from medical ontologies to generate a structured Knowledge Base (KB) of patient facts. Clinical Rules written over this KB could then be used to develop systems that can help with a variety of clinical tasks such as decision support alerts in diagnostic process. We propose a generic text and ontology driven information extraction framework. In the first phase, preprocessing techniques such as section tagging, dependency parsing, gazetteer lists are used filter clinical terms from the raw data. The clinical records are parsed using Clinical Text Analysis and Knowledge Extraction System, to extract prior medical history, medications, observations, laboratory results etc. For every concept we consider its polarity, section in which the concept occurs, the associated numerical value, synonyms etc. In the second phase, a domain specific medical ontology is used to establish relation between the extracted clinical terms. The output of this phase is a KB that stores medical facts about the patient. In the final phase, an OWL reasoner and clinical rules are used to infer additional facts about patient and generate a richer KB which can then be queried for a variety of clinical tasks. To demonstrate a proof of concept, we use discharge summaries from the cardiovascular domain to determine the TIMI Risk Score and San Francisco Syncope score for a patient
The Evolution of Carotenoid Coloration and Pigmentation in the New World Blackbirds
No full textPlumage color evolution in birds has been the focus of theoretical and empirical research on sexual selection since Darwin. Many of the yellow, orange, and red hues seen in bird plumage are the result of carotenoid pigmentation. While a great number of recent studies have examined the functions of carotenoid-based plumage coloration in a single species, few have examined the evolutionary history of this trait in a comparative phylogenetic context. Using the New World blackbirds as a model clade, I focus on two questions that a comparative phylogenetic approach can uniquely address. First, what is the history of evolutionary change in carotenoid color that led to the colors seen in extant blackbird taxa? Second, by what proximate mechanisms have carotenoid pigments evolved? In Chapter 1, I present an ancestral state reconstruction of carotenoid-based plumage coloration across the Icterid phylogeny, based on reflectance measurements of museum skins. My results show robust evidence that red coloration was gained repeatedly from a yellow common ancestor. In Chapter 2, I used pigment biochemistry of meadowlark (Sturnella) and Cacique (Cacicus) feathers to test whether independent gains of red coloration are the result of parallel or convergent metabolic mechanisms. Meadowlarks have evolved red coloration using a different set of carotenoids than caciques, but the caciques have evolved the same set of carotenoids twice. This suggests that red coloration evolved by convergent evolution among different blackbird clades, but evolved by parallel evolution within the caciques. Lastly, in Chapter 3 I examine the relationship between color and carotenoid pigmentation in orioles, a blackbird clade in which orange has been gained at least twice independently from a yellow common ancestor. I found red-producing keto-carotenoids only in orange species and never in yellow species. This result is a striking contrast to our expectation for a continuous gradient of a carotenoid pigment concentration. These results suggest that repeated gains of C4-oxygenation ability best explain evolutionary changes in orange coloration in orioles. To summarize, I showed using phylogenetic comparative methods that blackbirds have repeatedly evolved towards redder carotenoid coloration. Using HPLC biochemistry, I showed that each of these gains of orange and red coloration is likely the result of a gain of C4-oxygenation ability. The prevalence of gains of orange and red coloration suggests that there may be a directional bias towards evolving longer-wavelength carotenoid plumage. The research presented in these chapters provides the phylogenetic framework necessary for future studies to examine the functional causes underlying the repeated evolution of carotenoid-based coloration
The Characterization of Carbon Nanotube Infused Glass Fibers by Single Filament Fragmentation Test Methods
No full textSingle filament fragmentation tests were completed for individual glass fibers with varying surface treatments and carbon nanostructure infusions. Fiber fragmentation was analyzed by embedding a single filament into a standard tensile interface, which provided shear stress transfer between a conventional epoxy resin system and the constituent filament. Established single filament fragmentation techniques were used to characterize fiber and interface properties. A novel method of comparing fibers is introduced by correlating bundle tow test results to fiber fragmentation critical length data to qualitatively relate fiber performance. Photoelastic birefringent stress fringes were processed at select fiber fragmentation locations to further characterize the fiber-resin, or fiber-carbon nanostructure-resin, interface. Overall, the performance matrix qualitative comparison method, coupled with stress fringe analysis, proved to be an effective means of qualitatively evaluating fiber and processing parameters, and efficiently identifies the most fruitful path forward for optimized fiber development
SUPPORTING CITIZEN SCIENCE AND BIODIVERSITY INFORMATICS ON THE SEMANTIC WEB
No full textA question faced by semantic web developers is how much and what form of explicit semantics to encode in domain ontologies. A typical answer to this question is that it depends on the use case. This suggests the question Can we create ontologies that support multiple use cases, in situations where those use cases have conflicting ontology-design requirements? We present an approach to building ontologies by layer, and results that suggest that, at least in the domains of citizen science and biodiversity informatics, the answer to that question is yes. The layers that we develop correspond to patterns in the RDF graph. This contrasts with typical approaches to modular ontology development, where the layers are domain based. The three primary motivations for this approach are i) preserving computational tractability; ii) enabling easy coupling and decoupling with foundational ontologies and iii) maintaining cognitive tractability. This third motivation is still under-studied in semantic web development; we consider it in relation to reducing the ease with which ontology users can publish data that accidentally implies things that they do not mean. This is important always, but becomes especially so in citizen science, where users will naturally bring intuitive semantics to the terms that they encounter. We describe case studies that involved deploying our approach in the context of citizen science events, and which provided opportunities to assess its capabilities and limitations. We also describe subsequent work aimed at addressing these limitations, and, by applying newly defined layers over the underlying data, show that we are able to improve the competency of our knowledge base. More generally, we show that appropriately combining triple-pattern-based layers allows us to support a wide variety of use cases with varied (and occasionally conflicting) requirements. In addition to our approach to semantic layering, contributions include a better understanding of how to fuse social and semantic computing to support citizen science, and, specifically, a collection of semantic layers for representing biodiversity information in RDF, demonstrated to support a variety of citizen science use cases, with a focus on those that involve invasive species. Unlike other proposed semanticizations of the Darwin Core standard for representing biodiversity occurrence data, these layers involve minimal modification to the current Darwin Core vocabulary, and make maximal use of the Darwin Core namespace. Therefore, they significantly simplify the transitioning of current practices onto the semantic web
High Power Mid-Infrared Quantum Cascade Laser Array For Standoff Photoacoustic Chemical Detection
No full textQuantum cascade lasers (QCLs) are compact, portable, powerful semiconductor laser sources with emission wavelengths from mid-infrared (mid-IR) to terahertz (THz) regions of the electromagnetic spectrum. Mid-IR (i.e. wavelengths from 3 to 20 ?m) QCLs are of great importance in a wide range of applications such as trace gas sensing, environmental monitoring, free space communication, medical diagnosis and so on. High power QCLs are particularly important to applications such as infrared counter measure (IRCM) and standoff chemical detections. In such applications, the system performances critically depend on the amount of power a QCL can produce. This dissertation includes two major studies: the first part of the dissertation includes design, fabrication and characterization of high power mid-IR QCL arrays; the second part involves standoff chemical detection using QCLs as laser sources and photoacoustic effect as sensing technologies. In the first part of the dissertation, we design, fabricate and characterize multi-emitter QCL arrays consisting of multiple narrow laser stripes. Simulation results indicate that the proposed multi-emitter laser arrays present much better thermal performance than a broad area laser device, while having the same thermal management ability as a single narrow stripe device. We have successfully fabricated edge emitting and surface emitting QCL arrays with 5 and 16 emitters. Experimental results show that, with the same laser cavity length, a QCL array with 5 emitters produces over 3 times more power than a single emitter laser device. QCL array with 16 emitters generates about 4 W output peak power at wavelength ~7.9 ?m. We have also fabricated surface emitting QCL arrays and demonstrated single mode emission. The second part of the dissertation involves using high power mid-IR QCLs to perform standoff chemical detections based on photoacoustic sensing technologies. Photoacoustic effect is a light-matter interaction effect that involves generation of acoustic waves when a medium absorbs electromagnetic energy from light. It has been known as a sensitive spectroscopic technique for chemical sensing. Standoff photoacoustic chemical detection with distance more than 41 feet using quantum cascade laser operated at relatively low power, less than 40 mW, is demonstrated. A theoretical model is developed for pulsed laser photoacoustic effect in open-air environment. The standoff photoacoustic signal can be calibrated as a function of different parameters such as laser pulse energy, gas vapor concentration and detection distance. The results yield good agreements with theoretical model. Standoff detection of solid phase explosive chemicals has also been demonstrated by the use of an ultra-sensitive microphone and acoustic reflector. More than 8 feet detection distance is obtained for standoff photoacoustic sensing of explosives
The Independent and Interactive Roles of Spatial Variation and Dispersal on Zooplankton Metacommunity Structure
No full textIn recent years, there has been a growing desire among natural resource mangers to maintain and promote biodiversity in the built environment. Though some management practices are implemented extensively in developed landscapes, their ecological implications are not currently known. The goal of this study was to determine the effects of both dispersal and spatial variation in habitat conditions on biodiversity in urban zooplankton metacommunities. A five-week mesocosm experiment was performed in which human management and elevated zooplankton dispersal rates were manipulated in a series of four-pond metacommunities. Results indicate that dispersal had a significant negative effect on species turnover between communities but did not significantly affect local richness. It was also demonstrated that dispersal and the interaction of the dispersal and management treatments could significantly affect zooplankton density. These results highlight the importance of understanding the complex effects of dispersal and human management regimes on maintaining biodiversity in urban environments
MULTICAST ROUTING WITH BYZANTINE ROBUSTNESS
No full textNetwork problems arise when nodes behave in arbitrary ways such as sending malformed messages, sending incorrect messages or not forwarding messages at all to other nodes in the network. These faults are called Byzantine failures. In a real network, these faults can be a result of hardware failure, cyber-attacks or network congestion. Due to the serious problems these faults can cause, it becomes important to make the network robust against them, so that the network continues to operate properly or degrades in an acceptable way in the presence of such faults. In this thesis, we propose methods that include multiple node disjoint path calculations and robust flooding to find byzantine-free multicast trees. By finding such trees, we can guarantee the delivery of the messages from a source to a particular multicast group
Factors Associated with Successful Conditional Release for Individuals Found Not Criminally Responsible (NCR) in the State of Maryland
No full textFor the majority of individuals found guilty but not criminally responsible (NCR), inpatient hospitalization is no longer the final step in treatment and rehabilitation, but is instead a stepping stone on the way to community reintegration. In order to facilitate the transition to community reintegration, individuals found NCR are placed in a community monitoring or aftercare program, similar to probation or parole. In Maryland, this program, known as conditional release, is operated by the Community Forensic Aftercare Program (CFAP) with a typical conditional period being set for 5 years. Because conditional release is now the expected outcome, it is important to examine predictors of successful community reintegration for individuals found NCR. The present study examined 179 participants found NCR in Maryland through the first 5 years of their conditional release plan, with a primary goal of determining which variables are associated with success on the plan (i.e., absence of hospital warrant and/or criminal re-offense). Both static variables (i.e., those measured at one time-point and generally non-malleable by external providers), as well as dynamic variables (i.e. those measured at multiple time-points and generally open to influence by external providers) were examined in the prediction of successful conditional release. Results revealed that, of the static predictors, prior criminal history (i.e., 1 or more previous charges) and race (i.e., racial minority status) were significant predictors of failure on conditional release and that, of the dynamic predictors, absence of structured daily activity and less than weekly treatment significantly predicted conditional release failure. Findings from the present study suggest that it is not only static variables within the individual, such as demographic factors, that may predict success on conditional release, but also dynamic predictors, such as treatment frequency and participation in activity that may predict conditional release success. These findings contribute to the literature, by suggesting that the structure of the conditional release plan, which is influenced by the treatment providers and CFAP monitors, may play a significant role in helping individuals found NCR to successfully integrate into the community
A Model of Contextual Factors and their Effects in the Interruptive Notification User Experience
No full textInterruptive notifications in a desktop environment are an important service that knowledge workers rely on for maintaining awareness of information and services outside their current focus. Research to date has focused primarily on empirical laboratory-based testing, which is very specific and out of context of a realistic user environment, and broad ethnographic research, which is not specific enough for meaningful notification system design guidelines. This dissertation aims to address the gap between existing laboratory-based and ethnographic research by conducting a series of studies that explored the notification user experience in a both broad and deep way. The results of this research contribute the following: A catalog of significant contextual factors that affect the notification user experience; a series of models that describe how factors in the notification system context influence the overall user experience; a set of design guidelines, derived from this research but generalized to be applicable to any interruptive notification system