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 Collection: UNT Theses and Dissertations
Temporally Correct Algorithms for Transaction Concurrency Control in Distributed Databases

Temporally Correct Algorithms for Transaction Concurrency Control in Distributed Databases

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Date: May 2001
Creator: Tuck, Terry W.
Description: Many activities are comprised of temporally dependent events that must be executed in a specific chronological order. Supportive software applications must preserve these temporal dependencies. Whenever the processing of this type of an application includes transactions submitted to a database that is shared with other such applications, the transaction concurrency control mechanisms within the database must also preserve the temporal dependencies. A basis for preserving temporal dependencies is established by using (within the applications and databases) real-time timestamps to identify and order events and transactions. The use of optimistic approaches to transaction concurrency control can be undesirable in such situations, as they allow incorrect results for database read operations. Although the incorrectness is detected prior to transaction committal and the corresponding transaction(s) restarted, the impact on the application or entity that submitted the transaction can be too costly. Three transaction concurrency control algorithms are proposed in this dissertation. These algorithms are based on timestamp ordering, and are designed to preserve temporal dependencies existing among data-dependent transactions. The algorithms produce execution schedules that are equivalent to temporally ordered serial schedules, where the temporal order is established by the transactions' start times. The algorithms provide this equivalence while supporting currency to the ...
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Teen ages: Youth market romance in Hollywood teen films of the 1980s and 1990s

Teen ages: Youth market romance in Hollywood teen films of the 1980s and 1990s

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Date: May 2001
Creator: Murphy, Caryn E.
Description: This thesis examines the differences between teen romantic comedy films marketed to Generation X teenagers in the 1980s and Generation Y teenagers in the 1990s, focusing on the presentation of gender roles, consumptive behavior, and family. The 1980s films are discussed within the social context of the Reagan era and the conservatism of the New Right. The 1990s films are examined as continuing a conservative sensibility, but they additionally posit consumption as instrumental to achieving an idealized romance. Romantic comedy is traditionally a conservative genre, but these films illustrate female liberation through consumption. The source of difference between the cycles of teen romantic comedy is attributed to the media's attempt to position Generation Y teenagers as ideal consumers.
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Distribution and Probable Sources of Nitrate in the Seymour Aquifer, North Central Texas, USA

Distribution and Probable Sources of Nitrate in the Seymour Aquifer, North Central Texas, USA

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Date: May 2001
Creator: Hillin, Clifford K.
Description: This study utilized GIS and statistical methods to map the spatial variability of nitrate and related groundwater constituents in 30 counties above the Seymour Aquifer, analyze temporal patterns of nitrate pollution, identify probable sources of pollution, and recommend water development strategies to minimize exposure to nitrate and reduce future aquifer contamination. Nitrate concentrations in excess of 44 mg/L (US EPA limit) were commonly observed in the Seymour Aquifer region, especially in the central agricultural belt. Data indicated that this is an ongoing problem in the Seymour Aquifer and that agricultural activity and rural septic systems are the likely sources of the nitrate. Inconclusive results emphasized the need for a more comprehensive spatial and temporal water quality monitoring.
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Evaluation of MPLS Enabled Networks

Evaluation of MPLS Enabled Networks

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Date: May 2003
Creator: Ratnakaram, Archith
Description: Recent developments in the Internet have inspired a wide range of business and consumer applications. The deployment of multimedia-based services has driven the demand for increased and guaranteed bandwidth requirements over the network. The diverse requirements of the wide range of users demand differentiated classes of service and quality assurance. The new technology of Multi-protocol label switching (MPLS) has emerged as a high performance and reliable option to address these challenges apart from the additional features that were not addressed before. This problem in lieu of thesis describes how the new paradigm of MPLS is advantageous over the conventional architecture. The motivation for this paradigm is discussed in the first part, followed by a detailed description of this new architecture. The information flow, the underlying protocols and the MPLS extensions to some of the traditional protocols are then discussed followed by the description of the simulation. The simulation results are used to show the advantages of the proposed technology.
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Carbon nanotube/microwave interactions and applications to hydrogen fuel cells.

Carbon nanotube/microwave interactions and applications to hydrogen fuel cells.

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Date: May 2004
Creator: Imholt, Timothy James
Description: One of the leading problems that will be carried into the 21st century is that of alternative fuels to get our planet away from the consumption of fossil fuels. There has been a growing interest in the use of nanotechnology to somehow aid in this progression. There are several unanswered questions in how to do this. It is known that carbon nanotubes will store hydrogen but it is unclear how to increase that storage capacity and how to remove this hydrogen fuel once stored. This document offers some answers to these questions. It is possible to implant more hydrogen in a nanotube sample using a technique of ion implantation at energy levels ~50keV and below. This, accompanied with the rapid removal of that stored hydrogen through the application of a microwave field, proves to be one promising avenue to solve these two unanswered questions.
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Expression of G-protein Coupled Receptors in Young and Mature Thrombocytes and Knockdown of Gpr18 in Zebrafish

Expression of G-protein Coupled Receptors in Young and Mature Thrombocytes and Knockdown of Gpr18 in Zebrafish

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Date: May 2013
Creator: Potbhare, Vrinda Nikhil
Description: In this study, a novel method based on biotinylated antibodies and streptavidin coated magnetic beads was used to separate the thrombocyte subpopulations from zebrafish whole blood. DiI-C18, a lipophilic dye, labels only young thrombocytes when used at low concentrations. Commercially available biotinylated anti-Cy3 antibody was used to label the chromophore of DiI-C18 on the young thrombocytes and streptavidin coated magnetic beads were added subsequently, to separate young thrombocytes. The remaining blood cells were probed with custom-made biotinylated anti-GPIIb antibody and streptavidin magnetic beads to separate them from other cells. Further, thrombocytes are equivalents of mammalian platelets. Platelets play a crucial role in thrombus formation. The G-protein coupled receptors (GPCRs) present on the platelet surface are involved during platelet activation and aggregation processes. So, thrombocytes were studied for the presence of GPCRs. The GPCR mRNA transcripts expressed in the young and mature thrombocytes were subjected to densitometry analysis and pixel intensities of the bands were compared using one way ANOVA. This analysis did not show significant differences between the young and mature GPCR mRNA transcripts but identified a novel GPCR, GPR18 that was not reported in platelets earlier. To study the function of this GPCR, it was knocked down using GPR18 ...
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Interspecimen Study of Bone to Relate Macromechanical, Nanomechanical and Compositional Changes Across the Femoral Cortex of Bone

Interspecimen Study of Bone to Relate Macromechanical, Nanomechanical and Compositional Changes Across the Femoral Cortex of Bone

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Date: May 2013
Creator: Nar, Mangesh
Description: Mechanics of bone is widely studied and researched, mainly for the study of fracture. This has been done mostly on a macro scale. In this work hierarchical nature of bone has been explored to investigate bone mechanics in more detail. Flexural test were done to classify the bones according to their strength and deflection. Raman spectroscopy analysis was done to map the mineralization, collagen crosslinking changes across the thickness of the bone. Nanoindentation was done to map indentation hardness and indentation modulus across femoral cortex of the bone. The results indicate that the composition of the bone changes across the thickness of the femoral cortex. The hypothesis is confirmed as increase in mineralization, carbonate to phosphate ratio and collagen crosslinking shows the effect as increased indentation hardness and modulus and decreased deflection.
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Investigating Postpartum Depression in Southern Rural Egypt and Effects of Sertraline on Fsh and Lh Gene Expression on Fathead Minnows Using Rt-pcr

Investigating Postpartum Depression in Southern Rural Egypt and Effects of Sertraline on Fsh and Lh Gene Expression on Fathead Minnows Using Rt-pcr

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Date: May 2013
Creator: Mohamed, Hagar Abdo
Description: Postpartum depression (PPD) is a major health problem that affects many women worldwide. In Egypt, PPD is neglected despite the expected high prevalence rate among women during the transition period after the Egyptian revolution. This research investigated the prevalence, risk factors, and interventions of postpartum depression in southern rural Egypt. Interviews were conducted with 57 participants recruited from public and private hospitals. Questionnaires and the Arabic version of the Edinburgh Postnatal Depression Scale were administered. The prevalence of PPD is 73.7%. PPD is associated with low income and age at childbirth. Most participants regarded screening mothers after childbirth for PPD as effective; in comparison to, antidepressants that were regarded by most participants as ineffective. Women in southern rural Egypt prefer high number of pregnancies, so investigating the influence of sertraline, an antidepressant medication, on female hormones becomes important. In this research, fathead minnows were exposed to 3 and 10 ppb sertraline for 7 days. Real-time Polymerase Chain Reaction was used to detect the change in gene expression of the Follicle-stimulating hormone (FSH) and luteinizing hormone (LH). Results showed that a down regulation at the 10 ppb was evident on the LH and to a lesser extent on FSH. Our results ...
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My Crown Is in My Heart, Not on My Head: Heart Burial in England, France, and the Holy Roman Empire From Medieval Times to the Present

My Crown Is in My Heart, Not on My Head: Heart Burial in England, France, and the Holy Roman Empire From Medieval Times to the Present

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Date: May 2013
Creator: Duch, Anna M.
Description: Heart burial is a funerary practice that has been performed since the early medieval period. However, relatively little scholarship has been published on it in English. Heart burial began as a pragmatic way to preserve a body, but it became a meaningful tradition in Western Europe during the medieval and early modern periods. In an anthropological context, the ritual served the needs of elites and the societies they governed. Elites used heart burial not only to preserve their bodies, but to express devotion, stabilize the social order and advocate legitimacy, and even gain heaven. Heart burial assisted in the elite Christian, his or her family, and society pass through the liminal period of death. Over the centuries, heart burial evolved to remain relevant. The practice is extant to the present day, though the motivations behind it are very different from those of the medieval and early modern periods.
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Warrior Women in Early Modern Literature

Warrior Women in Early Modern Literature

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Date: May 2013
Creator: Oxendine, Jessica Grace
Description: Fantasies about warrior women circulated in many forms of writing in early modern England: travel narratives such as Sir Walter Ralegh's The Discoverie of Guiana (1595) portray Amazon encounters in the New World; poems like Edmund Spenser's The Faerie Queene (1596) depict women's skill with a spear; and the plays of Shakespeare, John Fletcher, and others stage the adventurous feats of women on the battlefield. In this dissertation, I analyze the social anxieties that emerge when warrior women threaten gender hierarchies in the patriarchal society of early modern England. The battlefield has traditionally been a site for men to prove their masculinity against other men, so when male characters find themselves submitting to a sword-wielding woman, they are forced to reimagine their own masculine identities as they become the objects acted upon by women. In their experience of subjectivity, these literary warrior women often allude to the historical Queen Elizabeth I, whose reign destabilized ideas about gender and power in the period. Negative evaluations of warrior women often indicate anxiety about Elizabeth as an Amazon-like queen. Thus, portrayals of warrior women often end with a celebration of patriarchal dominance once the male characters have successfully contained the threat of the ...
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