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1
Chis, Mihaela-Ana. "Mesure du tenseur de susceptibilité non linéaire d'ordre trois par traitement d'images." Angers, 1996. http://www.theses.fr/1996ANGE0005.
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Nous proposons une nouvelle technique de mesure très simple dite technique d'imagerie linéaires d'ordre trois. L'objet optique choisi détermine une configuration expérimentale Zernike non linéaire, dans un système d'imagerie (4f) afin de mesurer les susceptibilités non équivalentes à un couplage de deux ondes dans un milieu non linéaire. La mesure de la distribution spatiale de l'intensité lumineuse des impulsions laser picosecondes à l'aide d'une caméra CCD, améliore la précision et simplifie les mesures. Le principe de mesure est base sur la comparaison entre le profil d'intensité dans une image expérimentale et celui d'une image simulée. Afin de valider la méthode proposée, des mesures de susceptibilité ont été effectuées sur des matériaux de référence. Un bon accord est obtenu avec des précédentes mesures effectuées par différents auteurs. La méthode s'avère très intéressante par sa simplicité et par ses applications.
2
Evans, Gareth. "RIG-I-like receptors (RLRs) : viral sensors that recognize Coxsackieviruses." Thesis, Cardiff University, 2012. http://orca.cf.ac.uk/42650/.
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The innate immune system is a vital part of the body's defences against viral pathogens. RIG-I and MDA5 belong to the retinoic acid inducible gene-I (RIG-I)-like receptors (RLRs) family and function as cytoplasmic PRRs that are involved in the elimination of actively replicating RNA viruses. Their location and their differential responses to RNA viruses emphasises the complexity of the innate detection system. RIG-I and MDA5 contribute to antiviral signalling in different ways depending on the virus involved. Coxsackieviruses are positive sense, single-stranded RNA viruses belonging to the Enterovirus genus of the Picornaviridae family. They cause many serious diseases, including viral myocarditis (which can lead on to dilated cardiomyopathy), aseptic meningitis, and pancreatitis. In order to identify which RLR recognises these viruses and which RNA species triggers RLR activation during Coxsackievirus infection, viral ssRNA and replicative intermediates of Coxsackievirus RNA as well as synthetic dsRNA were used in this study. The results revealed that MDA5 recognises not the genomic ssRNA but the dsRNA generated by the replication of these viruses. Confocal microscopy provided unique evidence between the relationship of viral dsRNA and MDA5 while cytokine assays using HEK-MDA5 cells showed a strong immune response to Coxsackievirus and the dsRNA intermediates. This shows very strong evidence that MDA5 is a key sensor of the dsRNA intermediate of Coxsackieviruses. As RIG-Is role in Coxsackie recognition still needs to be verified Huh7 and Huh7.5.1 cells were used and showed no difference in immune response in the absence of RIG-I to Coxsackievirus infection, as well as the isolated ssRNA, suggesting that the VPg group present on the RNA blocks recognition. Furthermore immunoprecipitation experiments showed that in response to Coxsackievirus stimulation, RLRs homodimerise as well as heterodimerise with LGP2, potentially upregulating their activity as a possible mechanism for viral detection. The data presented here show a much clearer role for RLRs in Coxsackievirus infection, while opening new questions as to MDA5s role in the diseases caused by Coxsackieviruses, as well as the specifics behind dimerisation of the RLRs
3
Edozien, Leroy Chuma. "Protecting self-determination in healthcare : a comparative study of the consent model and a novel property model." Thesis, University of Glasgow, 2013. http://theses.gla.ac.uk/4265/.
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It is generally accepted in legal and bioethical discourse that the patient has a right to self-determination. The competent patient should be in a position to make informed decisions about his/her care. In practice, this is often not the case. Paternalism, the approach to medical practice that left decision-making in the hands of the doctor, is waning and it is increasingly recognised in both the legal and medical arenas that there are values other than medical factors which determine the choices that patients make. Unfortunately, these developments have not resulted in huge advances for patient self-determination. This is largely because the mechanism by which the law purports to protect self-determination – the consent model – has fundamental flaws that constrain its effectiveness. In the last three decades, various attempts have been made to reconceptualise consent on order to make it fit for purpose, but these have achieved only limited success. This thesis starts with the premise that it is often more productive to consider what an alternative model has to offer, than to persist with amelioration of a model that is fundamentally flawed. The limitations of the consent model are discussed and a novel model, the property model, is advocated. The theoretical underpinnings of this model and its structure are presented. Essentially, the patient’s bodily integrity is protected from unauthorised invasion, and his/her legitimate expectation to be provided with the relevant information and opportunity to enable him/her make an informed decision regarding treatment is taken to be a proprietary right. It is argued that the property model potentially overcomes the limitations of the consent model, including the obstacle caused by the requirement to prove causation in consent cases. The property model provides a means by which the patient’s right to self-determination can be recognised as a distinct legal right. The model does not create new rights, only seeking to afford stronger protection of an existing right. No constitutional, professional, or other conflict is generated by applying property analysis to patient self-determination. The model fits with the rights-based approach that the courts have evolved in UK consent cases, and is consistent with modern medical professionalism.
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Dickerson, Andrew P. "Industrial conflict in Britain." Thesis, University of Warwick, 1992. http://wrap.warwick.ac.uk/4265/.
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The economic analysis of conflict in Britain has previously concentrated on examining aggregate strike frequency. The thesis recognises the limitations of this approach and argues for the investigation of a broader definition of conflict and at a more disaggregated level. While weakly encompassing previous theoretical work, the principal objective is to establish the patterns and trends pertaining to wider set of measures of conflict in post-war Britain. The empirical investigation of these disaggregated dimensions of conflict and their inter-relationships appears to have previously received only very limited attention. Following a critique of the extant theoretical and empirical literature, the first substantive chapter examines the traditional aggregate- econometric models of strike frequency. These are shown to be unsatisfactory in a number of ways. The chapter then turns to the central issue of the procyclicality of strikes. It is shown that while the total number of strikes is only very loosely related to the cycle, strikes arising over the level of remuneration bear a much closer correspondence with the level of economic activity and this finding accords with many of the theoretical models that have been proposed for strike. activity. The chapter concludes with an examination of a cyclical-political model of strikes within which the impact of the recent reforms in labour legislation is also investigated. One of the central arguments of the thesis is that the emphasis on strike frequency is inappropriate. This is most clearly illustrated by the fact that while strike frequency fell by almost one quarter between 1980 and 1984, the incidence of strikes at the establishment level actually increased by 45%. An examination of the determinants of the incidence of conflict activity forms the basis of the second substantive chapter of the thesis. As a subsidiary theme, the complementary nature of strike and non-strike action is also explored. The next chapter investigates the ceteris paribus differences in strike probabilities between the public and private sectors. While the levels of strike incidence and frequency appear to be much higher in the public sector, much of the divergence is found to be a consequence of differences in the characteristics of the two sectors. Additionally, when weighted by employment and/or union coverage, strike frequency is found to be lower in the public sector and, moreover, each of these strikes tends to be shorter and involve fewer workers. The final substantive chapter looks at the impact of strikes on industry output and efficiency. The structure of the model is novel in that a production frontier is estimated without having recourse to an explicit functional form for the inefficiency component. This is due to the availability of a panel of data in which the fixed effects can be viewed as capturing both the inefficiency term as well as the industry fixed effect. A second stage estimation is then used to identify each industry's level of efficiency. While strikes do not appear to reduce output in aggregate, there is some evidence to suggest that those industries which incur a large number of short strikes do have their output significantly disrupted. This loss of output also serves to make these industries less efficient in general. Thus a major conclusion is that a disaggregated approach is necessary in order that the multi-dimensional nature of conflict and the sectoral diversity in the incidence of industrial action can be investigated in a satisfactory manner. Any new theories of conflict will need to encompass the empirical findings of the thesis.
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Dyde, Richard Thomas. "Illusions of visual orientation : comparisons between perceptual and visuo-motor tasks." Thesis, Durham University, 2001. http://etheses.dur.ac.uk/4265/.
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The Milner and Goodale (1995) model of dual cortical visual systems suggests that, in the primate cortex, separate neural substrates dominate the tasks of visual perception and visuo-motor control. This model derives from a number of independent sources of evidence: anatomical, physiological and behavioural. Neuropsychological evidence in humans suggests that visual perception and visuo-motor control can be selectively impaired through damage to the ventral and dorsal visual streams respectively. Evidence has emerged that in the healthy human visual cortex, differentiable effects of visual illusions can be found between the two measures of perception and visuo- motor control. This evidence has been cited to support the Milner and Goodale (1995) model. The series of studies reported in this dissertation used a similar, but methodologically revised application of the illusion paradigm in the novel domain of orientation. Using two types of visual illusions, the simultaneous tilt illusion (STI) and the rod-and-frame illusion (RFI), a series of studies found patterns of association, dissociation and interaction that strongly support the Mihier and Goodale model. The critical issue, in terms of predicting the pattern of effects across perception and visuo-motor control tasks, was found to be the siting of the causal mechanisms underlying the illusion employed.
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Moghimi, Farzad. "Spectrum sensing and throughput maximization in cognitive radio networks." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/42653.
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In cognitive radio (CR) systems, reliable spectrum sensing techniques are required in order to avoid interference to the primary users (PUs) of the spectrum. In this dissertation two spectrum sensing techniques are developed, and sensing time and power allocation are optimized in multi-input multi-output (MIMO) CR systems.
The motivation of the first proposed spectrum sensing technique is that, in practice, CRs also have to cope with various types of non-Gaussian noise such as man-made impulsive noise, and co-channel interference. However, most of the existing literature on spectrum sensing only considers impairment by additive white Gaussian noise (AWGN). To address this issue, we propose an Lp-norm detector which has tunable parameters that can be adjusted for the underlying type of noise. We also propose an adaptive algorithm for optimization of the Lp-norm parameters which does not require any a priori knowledge of the noise statistics. The motivation for the second proposed spectrum sensing technique is that the signals transmitted by PUs often also contain known pilot symbols for synchronization and channel estimation purposes. Coherent correlation based spectrum sensing techniques can exploit these known symbols but waste the energy contained in the data symbols. Hence, while considering AWGN impairment, we propose a hybrid coherent/energy detection scheme which exploits both the pilot and the data symbols transmitted by the PU. Since the complexity of the globally optimal hybrid detection metric is very high, we develop a simple locally optimal hybrid metric, which turns out to be a linear combination of an energy detection metric and a correlation metric.
While the proposed methods improve the accuracy of spectrum sensing, there exists a tradeoff between sensing time and transmission time for CR networks. In this thesis, we investigate this issue for conventional energy detection in MIMO CR networks. Specifically, we optimize the sensing threshold, sensing time, and transmit power of both single-band and multi-band MIMO CR systems for maximization of the opportunistic throughput under transmit power, probability of false alarm, and probability of detection constraints. We also develop efficient iterative algorithms for solving these non-convex optimization problems based on the concept of alternating optimization.
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Falk, Carl Francis. "Is there cultural variability in implicit self-esteem?" Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/42655.
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Cultural psychology research has cast doubt upon the assumption that self-enhancement motivations are universal – the majority of empirical research finding that those from East Asian cultural backgrounds self-enhance less than those from Western cultural backgrounds. However, measures of implicit self-esteem (ISE) – automatic and unconscious global self evaluations – do not often yield cultural differences. By using a diverse range of approaches, this dissertation seeks to shed light on the question of whether variability exists in implicit self-esteem across individuals from East Asian and Western cultural backgrounds. In Study 1, two different ISE measures provided divergent results regarding possible cultural variability in implicit self-esteem. In search for a valid measure of ISE, Study 2 simultaneously tested the convergent and predictive validity and cultural variation of popular and new ISE and explicit self-esteem measures. Since no single ISE measure in Study 2 was found to have adequate validity, Study 3 attempted to boost the validity of ISE measures. This was done based on the argument that ISE is better defined as a context-dependent/domain specific construct rather than a global self-evaluation, yet did not yield evidence in favour of the validity of any ISE measure. Supplementary analyses for Study 2 and the final two studies took an alternative approach to the problem of this dissertation and found cultural variability in phenomena theoretically connected to implicit self-esteem. In particular, cultural variability was evident in the theoretical correlates of implicit self-esteem from Study 2. Study 4 found evidence that cultural variability in the tendency to value an object after one owns the object (i.e., the endowment effect) is likely due in part to cultural variability in feelings about the self. Study 5 provided evidence that cultural variability exists in the tendency to display in-group favouritism after being arbitrarily assigned to a group (i.e., the minimal group effect), and that this cultural variability is explained in part by self-esteem. Taken together, these studies provide converging evidence that 1) implicit self-esteem measures are currently not a viable option for assessment of cultural variability, and 2) cultural variability in implicit self-esteem is likely.
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Taillefer, Rachel Elise. "Therapy-related hepatic mitochondrial dysfunction in patients co-infected with human immunodeficiency virus and hepatitis C virus and in HepG2 cells." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/42652.
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Background: Co-infection with HIV and hepatitis C virus (HCV) worsens liver disease and decreases highly active antiretroviral therapy (HAART) tolerability. HAART usually includes two nucleoside reverse transcriptase inhibitors (NRTIs) and a protease inhibitor (PI) or a non-NRTI (NNRTI). NRTIs, particularly D-NRTIs, can induce mitochondrial DNA (mtDNA) depletion, deletions or mutations and lead to mitochondrial dysfunction. Multi-drug resistance protein-1 (MDR1) transports drugs across cellular membranes and may modulate toxicity. This project investigated HAART-related mitochondrial toxicity in liver tissue from HIV/HCV co-infected individuals and in human hepatic (HepG2) cells.
Hypotheses:
1) Patients ON-HAART will have altered pathology scores, mtDNA quantity/deletions and mt-mRNA/MDR1-mRNA levels compared to patients OFF-HAART, and these will be influenced by type of HAART.
2) Treatment with the d-NRTI didanosine (ddI) and the PI saquinavir (SAQ) will alter HepG2 cell viability, population doubling time (PDT) and mtDNA content.
Methods: Double-liver biopsies were collected from HIV/HCV co-infected individuals. One sample was used to score pathology, the other to extract DNA and RNA. mtDNA quantity, mt-mRNA and MDR1-mRNA levels were investigated by quantitative-PCR and mtDNA deletion by long-template PCR. Measurements were compared between individuals ON- versus OFF-HAART, on D-NRTI versus other NRTIs and on PI versus NNRTI.
HepG2 cells were exposed to ddI and SAQ. Cell viability, PDT and mtDNA content were investigated.
Results: Individuals ON-HAART (N=34) were similar in age, gender and HCV genotype to those OFF-HAART (N=18), and the groups did not differ significantly in pathology score, mtDNA quantity/deletions or mt-mRNA/MDR1-mRNA levels. The same was true for individuals on D-NRTI (N=6) versus other NRTIs (N=28) and on PI (N=17) versus NNRTI (N=8), except that individuals on PI were older (p=0.044) with higher mt-mRNA levels (p=0.015).
Treatment of HepG2 cells with ddI lowered mtDNA content while SAQ decreased PDT. Addition of a second drug (SAQ or ddI) exacerbated these effects. ddI transiently decreased viability.
Conclusions: The lack of differences between the ON- and OFF-HAART groups supports previous observations that HAART is not associated with increased hepatic mitochondrial toxicity although the cell culture findings suggest complementary toxicity upon co-exposure to ddI/SAQ.
This study may inform management of HIV/HCV co-infected individuals.
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Sedgwick, James Burnham. "The trial within : negotiating justice at the International Military Tribunal for the Far East, 1946-1948." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/42658.
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This dissertation explores the inner-workings of the International Military Tribunal for the Far East (IMTFE). Commonly known as the Tokyo trial, Tokyo tribunal, or Tokyo IMT, the IMTFE brought Japan’s wartime leadership to justice for aggression, crimes against humanity, and war crimes committed during World War II. Using rare sources in three languages from public and private collections in eight countries, this dissertation presents a multi-perspective experiential history of the IMTFE in operation. By placing the court in a distinct international moment that produced the United Nations, the Nuremberg trial, the Genocide Convention, and the Universal Declaration of Human Rights, among other outgrowths of global community, this work explores the IMTFE as both a groundbreaking judicial undertaking and a pioneering multilateral institution. Other scholars use overly reductive and judgmental constructs based on outside-looking-in perspectives to assess the court’s legal or moral legitimacy without appreciating or detailing its nuance and complexity. This dissertation prefers an inside-out view to explain the trial, not judge it. It describes the IMTFE as a collective endeavour and experience behind the scenes. Chapters review the personal, emotional, administrative, logistical, legal, political, and global dimensions of internationalism in action. Justice emerged as a contested encounter inside an involute web of intimate and external factors; transitional and transnational forces. Outside pressures – including postwar idealism, decolonisation, and the Cold War – meshed with and filtered through the intrinsic elements of ‘being international’ on the ground: social interaction, personal responses, and professional engagement. This ‘trial within’ influenced every aspect of IMTFE processes and outcomes, and the complexity of its internal dynamics best explains enduring criticism and memory of the court as a political trial or manifestation of victors’ justice. Although a unique historical moment, the IMTFE reveals basic, foundational truths about the essence of all international organisations and other modes of ambitious global governance. Ultimately, this dissertation uses the IMTFE to reinterpret modern internationalism as a complex, messy, and negotiated encounter rather than a staid set of promises and ideals: a process and experience that ultimately – inevitably – compromised principles for politics, and form for function.
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Peng, Jiang Hong. "A study of softwood torrefaction and densification for the production of high quality wood pellets." Thesis, University of British Columbia, 2012. http://hdl.handle.net/2429/42654.
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British Columbia (BC) has become a major producer and exporter of wood pellets in the world. But the low energy density, the low water resistivity, the short shelf life, and the transportation cost impede the market development. Torrefaction, a thermal treatment without air or oxygen at 200-300°C, may provide a solution.
The present study developed the torrefaction kinetics of BC softwood residues in a thermogravimetric analyzer (TGA), studied the effect of the torrefaction reaction conditions on the properties of torrefied sawdust in a bench-scale fixed bed reactor and a bench-scale fluidized bed reactor, and identified the suitable conditions for making durable torrefied pellets in a press machine using torrefied samples. The weight loss of BC softwood residues significantly depended on the torrefaction temperature, the residence time, the particle size, and the oxygen concentration in the carrier gas. The weight loss could be approximately estimated from the weight loss of the chemical compositions. A two-component and one-step first order reaction kinetic model gave a good agreement with data over short residence time on the weight loss range of 0 to 40% at the temperature of 260-300°C.
The heating value of torrefied pellets had a close relationship with the weight loss, increasing with increasing the severity of torrefaction. The torrefied samples were more difficult to be compressed into strong pellets under the same conditions as used for making the control (regular, untreated, conventional) pellets. More energy was needed for compacting torrefied samples into torrefied pellets. Increasing the die temperature and adding moisture into torrefied samples could improve the quality of torrefied pellets. The moisture content and density of torrefied pellets were lower than control pellets. Considering the quality of torrefied pellets, the optimal torrefaction conditions appeared to correspond to a weight loss of about 30%, which gave a 20% increase in pellet heating value and good hydrophobicity. The suitable densification conditions corresponded to a die temperature of 230°C, or over 110°C for torrefied samples conditioned to 10% moisture content.
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Kelso, Eric W. "Improving the efficiency of aviation retention bonuses through the use of market mechanisms." Thesis, Monterey, California: Naval Postgraduate School, 2014. http://hdl.handle.net/10945/42658.
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Approved for public release; distribution is unlimitedAviation Career Continuation Pay (ACCP), the retention bonus for Naval Aviators, has historically failed to meet stated retention goals. For fiscal year 2013 Naval Personnel Command reported that ACCP exceeded retention goals in some communities by more than 60%, while simultaneously falling over 60% short of retention objectives in others. We analyze the potential for using auction mechanisms to improve upon these results by controlling cost, quantity, and quality of aviators retained. Using survey data to estimate aviators’ quality and willingness to stay in active duty naval aviation, we compare the results of ACCP against three mechanisms, 1) uniform-price auction, 2) Quality Adjusted Discount (QUAD) auction, and 3) Combinatorial Retention Auction Mechanism (CRAM). We find that by implementing a uniform-price auction naval aviation can exactly meet 100% of its retention objectives, while reducing costs in some communities by more than $2,200,000. Additionally, while we find no significant correlation between officer quality and retention costs, we demonstrate the potential for QUAD auctions to improve upon these results by further reducing retention costs and improving the overall quality of retained aviators. Lastly, our implementation of CRAMs reveals the potential to reduce individual retention costs nearly 20% through the use of non-monetary incentives.
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Joseph, Jeremy C. "Time impact of Expanded Process Control Procedures (EPCP)." Thesis, Monterey, California. Naval Postgraduate School, 2014. http://hdl.handle.net/10945/42652.
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Approved for public release; distribution is unlimitedThe United States Navy (USN) surface ships must receive maintenance and modernization in order to attain their expected lifetimes and the level of readiness that the Navy requires. A program called Enhanced Process Control Procedures (EPCP) aims to decrease the number and frequency of critical systems failures occurring during the maintenance availability. This research aims to identify the costs and benefits of the program, determine other factors that cause critical systems downtime and maintenance availability extensions, and provide recommendations to improve the EPCP program. The costs of the program are the increased time required to complete the work, greater funding requirements, decreased flexibility, and possible impact on the technicians. Analysis of EPCPs over an 18-month period between 2012 and 2014 revealed that the total time to develop, review, and correct the EPCP documentation averaged 28 days, with a standard deviation of 26 days. The 75% confidence value for the total administrative time required of an EPCP was almost 36 days. The author recommends using this time duration when planning a maintenance availability. The benefits of the program are a larger degree of accountability, lower probability of human error, and greater communication and coordination. The review of EPCPs suggest that the efficiency of the EPCP program could be improved by increasing the number of reused EPCPs, decreasing the number of EPCP errors, involving subject-matter experts in EPCP documentation, and decreasing the EPCP administrative temporal impact. Additionally, the author recommends the USN utilize an improved record keeping system to minimize delays in maintenance availabilities.
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Juriga, Jacob T. "Terrain aided navigation for REMUS autonomous underwater vehicle." Thesis, Monterey, California: Naval Postgraduate School, 2014. http://hdl.handle.net/10945/42654.
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Approved for public release; distribution is unlimitedThis research investigates the ability to create an undersea bathymetry map and navigate relative to the map. This is known as terrain aided navigation (TAN). In our particular case, the goal was for an autonomous underwater vehicle (AUV) to reduce positional uncertainty through the use of downward-looking swath sonar and employing TAN techniques. This is considered important for undersea operations where positioning systems such as GPS are either not available or difficult to put in place. There are several challenges associated with TAN that are presented: The image processing necessary to extract altitude data from the sonar image, the initial building of the bathymetry map, incorporating a system and measurement model that takes into consideration AUV motion and sensor uncertainty and near-optimal, real-time estimation algorithms. The thesis presents a methodology coupled with analysis on datasets collected from joint Naval Postgraduate School/National Aeronautical Space Administration experimentation conducted at the Aquarius undersea habitat near Key Largo, Florida. .
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Kemper, Brennan J. "Maximizing weapon system availability with a multi-echelon supply network." Thesis, Monterey, California: Naval Postgraduate School, 2014. http://hdl.handle.net/10945/42659.
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Approved for public release; distribution is unlimitedWeapon systems are comprised of parts that are subject to random failures. When a part fails, it must be replaced by an operable part that is provided by a supply network that supports the system. Supply networks consist of many locations where spare parts are held, known as echelons. Examples include depots, fulfillment centers, and customers. When many identical weapon systems operate in parallel and rely on a multi-echelon supply network for replacement parts, decision makers must choose where and how to invest their resources into the purchase of spare parts. This thesis uses stochastic optimization to leverage those decisions in order to maximize the expected number of time periods a set of weapon systems are available for use. Specifically, we develop a model that determines the optimal stock levels of spare parts to store at each echelon of the supply network. The formulation integrates part failure uncertainty, transit times, and monetary constraints. Model outputs also provide decision makers with a clear estimate of marginal availability gains for each dollar invested in purchasing spare parts.
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Jaffer, Navin. "Cyber security vulnerabilities during long term evolution power-saving discontinuous reception protocol." Thesis, Monterey, California: Naval Postgraduate School, 2014. http://hdl.handle.net/10945/42650.
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Approved for public release; distribution is unlimitedLong Term Evolution (LTE) is a wireless access communications network that consists of base stations called eNodeBs (eNBs), which allow connectivity between the mobile device or user equipment (UE) and the core network. To save battery power, the UE can turn off its radio transceiver circuitry, based on various parameters exchanged during the attach procedure with its serving eNB, using a protocol called discontinuous reception (DRX). During the DRX period, the UE is still connected to the network and its receiver is turned on periodically to determine if the eNB has sent any packets to it. This thesis develops the concepts of using simulation to demonstrate if a denial of service attack during the long DRX period, as hypothesized by some researchers, can be realized. Requirements for experimentation were identified and current simulation tools were evaluated as potential candidates. The tools applied were the LTE standards, the open source ns-3 network simulator and analysis of actual LTE packet traces. Follow-on studies will be required in order to address issues due to the incompleteness of the ns-3 LTE model and the incompatibility of the file format for LTE traces with that required by the Wireshark network protocol analyzer. Essentially, neither tool contains the DRX algorithm.
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Johnson, Paul R. "Trusted insiders are committing fraud and embezzlement within organizations: is there a connection to addiction, as the motivating factor for their illegal activities?" Thesis, Monterey, California: Naval Postgraduate School, 2014. http://hdl.handle.net/10945/42651.
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Approved for public release; distribution is unlimitedExtensive studies and research have been conducted on insider threats, the possible causes, predictive models and best practices for prevention, early detection, and mitigation of the threats of insider attacks to a wide range of critical infrastructure, government agencies, and the private sector. Current research shows a great deal of attention directed at the cyber threats toward organizations. In contrast, relatively little research has been conducted on the insider threat with regard to financial fraud and embezzlement to organizations. Left undetected, insiders can cause irreparable and devastating consequences to private and public sector organizations, which compromise the integrity of the overall financial system. Recent criminal cases have revealed a disturbing trend linking many of the trusted insiders convicted of conducting fraud or embezzlement within the victim organizations to an addiction to gambling or prescription drugs. Also alarming is the frequency of trusted insiders conducting fraud within government agencies to support their addiction. This paper studies research on insider threats, and suggests that addiction is a contributing factor to the motives of the insiders’ criminal behaviors. Research also suggests that accurate reporting by law enforcement agencies is not occurring in police reports on motives or causes of the reasons insiders are committing their crimes.
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Jurgensen, Sean M. "The rotated speeded-up robust features algorithm (R-SURF)." Thesis, Monterey, California: Naval Postgraduate School, 2014. http://hdl.handle.net/10945/42653.
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Approved for public release; distribution is unlimitedIncludes supplemental materials
Weaknesses in the Fast Hessian detector utilized by the speeded-up robust features (SURF) algorithm are examined in this research. We evaluate the SURF algorithm to identify possible areas for improvement in the performance. A proposed alternative to the SURF detector is proposed called rotated SURF (R-SURF). This method utilizes filters that are rotated 45 degrees counter-clockwise, and this modification is tested with standard detector testing methods against the regular SURF detector. Performance testing shows that the R-SURF outperforms the regular SURF detector when subject to image blurring, illumination changes and compression. Based on the testing results, the R-SURF detector outperforms regular SURF slightly when subjected to affine (viewpoint) changes. For image scale and rotation transformations, R-SURF outperforms for very small transformation values, but the regular SURF algorithm performs better for larger variations. The application of this research in the larger recognition process is also discussed.
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Kator-Mubarez, Amina. "The youth bulge and higher education in Afghanistan: challenges and the way forward." Thesis, Monterey, California: Naval Postgraduate School, 2014. http://hdl.handle.net/10945/42655.
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Approved for public release; distribution is unlimitedThe Afghan government is preparing to deal with the world’s largest youth bulge, a demographic event that threatens to destabilize the country if the Afghan government and U.S. aid agencies do not disarm the grievances of Afghan youth, especially at the university level. This thesis examines higher education in Afghanistan from the 1930s onward and describes how various regimes affected educational policy while in power. Also examined is how Afghan youth have historically been a source of instability if their grievances are not addressed. Despite tremendous efforts by the Afghan government and U.S. aid organizations to improve higher education after the Taliban era, implementing effective policies continues to problematic. This thesis answers the questions of why the Afghan government and U.S. aid agencies have had such a difficult time in implementing effective policies to address the youth bulge and challenges to higher education in the country. Evidence is provided to show that poor infrastructure, outdated curricula, unqualified instructors, corruption, religious activism, insecurity, high levels of unemployment, and underemployment are detrimental to national stability, as Afghan youth flock abroad in pursuit of better opportunities or join the insurgency out of desperation.
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Kaushish, Vidur. "Force limited vibration testing and subsequent redesign of the Naval Postgraduate School CubeSat launcher." Thesis, Monterey, California: Naval Postgraduate School, 2014. http://hdl.handle.net/10945/42656.
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Approved for public release; distribution is unlimitedThe Naval Postgraduate School CubeSat Launcher (NPSCuL) is a five-sided structure capable of carrying up to 24 CubeSats to orbit. The vibration test environment for CubeSats flying on NPSCuL on the Atlas-V is extremely harsh, partly due to the input vibration environment from the launch vehicle itself, and partly due to amplification from the NPSCuL structure. This thesis documents the implementation of a relatively new technology, Force Limited Vibration Testing (FLVT), and the design of a stiffer structure to reduce the vibration environment for NPSCuL payloads. Most acceleration-controlled vibration tests result in significant over-test. FLVT limits shaker forces, producing more realistic tests and potentially provides relief to payloads. Additionally, increasing the stiffness of NPSCuL using an isogrid design, aimed to increase its first-fundamental frequency, could result in less displacement at higher frequencies for a given amount of input energy, possibly improving the payload vibration environment. It was found that FLVT was very successful in reducing vibration environments for NPSCuL payloads. Although redesigning NPSCuL using an isogrid design achieved the goal of increasing system stiffness, it did not reduce the vibration environment. None the less, lessons learned from the redesign process will be valuable for continuing vibration environment reduction efforts.
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Keller, Anthony, Hong Choe, and Victor Diaz. "Sensemaking of narratives: informing the capabilities development process." Thesis, Monterey, California: Naval Postgraduate School, 2014. http://hdl.handle.net/10945/42657.
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Approved for public release; distribution is unlimitedThis capstone project determines whether sensemaking of soldier narratives can inform the Department of Defense‘s (DOD) capability development process (CDP). Sensemaking is the process of creating awareness and understanding in situations of high complexity or uncertainty. The authors gathered service member narratives concerning their use of fielded equipment, which created metadata for both quantitative and qualitative research and analysis. This capstone compares results from sensemaking of narratives with results from the Warfighter Technology Tradespace Methodology (WTTM), a system designed for the rapid fielding of equipment for small forward operating bases (FOBs) and combat outposts (COPs). The capstone finds that 1) soldier narratives inform the fielding process by providing an additional layer of meaning and context, and 2) soldier narratives do not replace current feedback mechanisms; rather, they play a complementary role. This capstone finds that narratives as a feedback mechanism can be applied during operational testing of newly developed or fielded equipment for the DOD‘s CDP.
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Linna, Jan-Roger. "Contribution of oil layer mechanism to the hydrocarbon emissions from spark-ignition engines." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/42654.
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Klayman, Klaus. "Design of the configuration and diagnostic units of the MAP chip." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/42652.
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Huang, Shih-Ying. "Structural analysis from system configurations for modeling and design of multi-energy domain dynamic systems." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/42659.
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Rykels, Sharon D. (Sharon Dwynelle). "Adapting communication structures for globally-networked manufacturing organizations." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/42656.
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Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1997, and Thesis (M.S.)--Massachusetts Institute of Technology, Sloan School of Management, 1997.Includes bibliographical references (p. 59-61).
by Sharon D. Rykels.
M.S.
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Krska, Shane William 1970. "Cyclization and cyclopolymerization of silicon-containing dienes ; Functionalization of carbosilane dendrimers." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/42651.
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Palucki, Brenda Lynn. "Synthesis of heterocyclic compounds via intramolecular [4+2] cycloadditions of conjugated enynes." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/42655.
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Muir, Stephen H. "Semiconductor fabrication capacity gains through optimal allocation of product loadings and equipment sharing across process technologies." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/42657.
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Thesis (M.S.)--Massachusetts Institute of Technology, Dept. of Electrical Engineering and Computer Science, 1997, and Thesis (M.S.)--Massachusetts Institute of Technology, Sloan School of Management, 1997.Includes bibliographical references (p. 101-102).
by Stephen H. Muir.
M.S.
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Kidd, La Creis R. "Estimation of exposure to two potent heterocyclic aromatic amines in various human populations and their role in colorectal cancer." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/42653.
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Chew, Cheewee P. "Shape optimization using a matrix-free Newton method." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/42650.
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Yaliraki, Sophia Nicolas. "Theoretical studies of electronic and nonlinear optical properties conjugated polymers." Thesis, Massachusetts Institute of Technology, 1997. http://hdl.handle.net/1721.1/42658.
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Skibinsky, Anna. "Modeling liquid-liquid phase transitions and quasicrystal formation." Thesis, Boston University, 2003. https://hdl.handle.net/2144/42658.
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Thesis (Ph. D.)--Boston University, 2003.In this thesis, studies which concern two different subjects related to phase transitions in fluids and crystalline solids are presented. Condensed matter formation, structure, and phase transitions are modeled using molecular dynamics simulations of simple discontinuous potentials with attractive and repulsive interactions. Novel phase diagrams are proposed for quasicrystals, crystals, and liquids. In the first part of the thesis, the formation of a quasicrystal in a two dimensional monodisperse system is investigated using molecular dynamics simulations of hard sphere particles interacting via a two-dimensional square-well potential. It is found that for certain values of the square-well parameters more than one stable crystalline phase can form. By quenching the liquid phase at a very low temperature, an amorphous phase is obtained. When this the amorphous phase is heated, a quasicrystalline structure with five-fold symmetry forms. From estimations of the Helmholtz potentials of the stable crystalline phases and of the quasicrystal, it is concluded that within a specific temperature range, the observed quasicrystal phase can be the stable phase. The second part of the thesis concerns a study of the liquid-liquid phase transition for a single-component system in three dimensions, interacting via an isotropic potential with a repulsive soft-core shoulder at short distance and an attractive well at an intermediate distance. The potential is similar to potentials used to describe [TRUNCATED}
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Casterlow, Samantha Alexandra. "Characterization and Pharmacokinetics of Rifampicin Laden Carboxymethylcellulose Acetate Butyrate Particles." Thesis, Virginia Tech, 2012. http://hdl.handle.net/10919/42659.
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Tuberculosis, caused by Mycobacterium tuberculosis (MTB), is a common and potentially lethal infectious human disease. Rifampicin is a front line anti-tuberculosis drug usually prescribed in combination with isoniazid, pyrazinamide and streptomycin for a period of six to seven months. When given orally for the treatment of MTB, rifampicin exhibits low bioavailability. Recent attempts to increase bioavailability and decrease dosage of anti-tuberculosis drugs have focused on creating polymer coated rifampicin nanoparticles. The research effort presented in this thesis evaluates the formation, characterization and relative bioavailability of rifampicin loaded carboxymethylcellulose acetate butyrate (CMCAB) particles using two different formulation techniques. Multi inlet vortex mixer (MIVM) and manual spray drying techniques were used to form the rifampicin containing CMCAB particles. Characterization studies and analyses of particles revealed differences in particle sizes, shapes and drug loading between the different particle formulation techniques. In vivo pharmacokinetic studies in BALB/c mice indicate that a single dose of rifampicin laden CMCAB spray dried particle formulations are able to improve pharmacokinetic parameters including relative bioavailability of rifampicin compared to that of the free drug form at the same concentration.Master of Science
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Law, Mary Kate. "Assessing Forgiveness: Development of a Brief, Broadly Applicable Self-report Measure." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/42653.
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Forgiveness is a construct that has captured the interest of researchers and practitioners across various fields, from philosophy to biology; however, defining and measuring forgiveness has been a challenge because of its complex nature. By drawing on relationships discovered in past studies, reviewing definitions across disciplines, and noting weaknesses in current forgiveness measures, the task of developing a broadly applicable forgiveness measure with strong theoretical and psychometric roots resulted in the creation of the General Measure of Forgiveness (GMF).
The GMF is a brief, Likert response questionnaire that is appropriate for both relationship and non-relationship transgressions; heretofore, there has not been an established measure for non-relationship trangressions. This study was an initial investigation into the psychometric properties of the GMF. In an online design, college participants (n=343) were administered the GMF along with an established interpersonal measure of forgiveness, the Enright Forgiveness Inventory (EFI: Enright & Rique, 2004), and other measures of theoretically related and unrelated constructs. For the forgiveness measures, participants completed the GMF and EFI (order counterbalanced) in response to the same self-generated relationship transgression, then completed the GMF in response to a self-generated non-relationship transgression.
Results supported the internal consistency of the GMF (Cronbachâ s alphas of .93 for both relationship and non-relationship forgiveness) and an exploratory factor analysis identified a primary factor accounting for about 30% of the total item variance. Convergent and discriminant validity analyses resulted in largely predicted relationships (e.g., r = .81 for GMFrelationship and EFI; r = .78 for GMFnon-relationship and a single-item assessment of forgiveness; r = -.26 for GMFrelationship and anger and aggression).
These results are encouraging as use of the GMF could open new areas of research in non-relationship forgiveness and enhance research and application of relationship forgiveness. Specifically, the GMF holds promise for improving research by providing a brief, non-proprietary, and broadly applicable measure of forgiveness. Broadly, the study suggests that a general measure of forgiveness is feasible.Master of Science
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Whisman, Derek K. "A Devil of a Coincidence: Study on Milton and Gower." Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/42655.
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The seventeenth-century epic poem Paradise Lost is one of the most widely studied texts in all of literary history. The work, written by John Milton, depicts Satanâ s fall from Heaven and subsequent deeds on Earth and in Hell. One of the more remarkable and, often, most overlooked scenes in the story involves the distinctive personification of Sin and Death. Milton depicts Sin as the daughter of Satan, with no mention of a mother, born through a process of spontaneous generation. Satan then becomes so captivated by his daughterâ s wickedness that he forces himself upon her, causing Sin to bear a son, Death. This illustration is striking, especially given that it also appears in the opening pages of the fourteenth-century Mirour de l'Omme (c. 1376) by John Gower. In both Milton and Gowerâ s poems, Satan, Sin, and Death are personified as having this familial, incestuous relationship which ultimately creates the worldâ s evils. Their depictions are not merely reminiscent of one another, but rather, often match up in nearly identical fashions. John S. P. Tatlock was the among the first to notice these similarities, but was also quick to express his hesitance to say with any sort of assurance that Milton had read Gower: â Since only one manuscript of the Mirour is known, and that was never published until seven years ago [1899], the chance is infinitesimal that Milton ever heard of the poem. But that his and Gowerâ s sources are ultimately the same seems to me highly probable.â Yet to date, no studies have been conducted to determine which shared sources could possibly lead Milton and Gower to construct such similar personifications of Sin and Death. Indeed, John Fisher notes that currently â the influence of the Mirour upon Paradise Lost remains an open question.â It is upon this open question that I now attempt to help fill this century-old void in literary researchMaster of Arts
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Cooper, Michele. "Mathematical Modeling of Vascular Tumor Growth and Development." Thesis, Virginia Tech, 2010. http://hdl.handle.net/10919/42656.
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Mathematical modeling of cancer is of significant interest due to its potential to aid in our understanding of the disease, including investigation into which factors are most important in the progression of cancer. With this knowledge and model different paths of treatment can be examined; (e.g. simulation of different treatment techniques followed by the more costly venture of testing on animal models). Significant work has been done in the field of cancer modeling with models ranging from the more broad systems, avascular tumor models, to smaller systems, models of angiogenic pathways. A preliminary model of a vascularized tumor has been developed; the model is based on fundamental principles of mechanics and will serve as the framework for a more detailed model in the future. The current model is a system of nonlinear partial differential equations (PDEs) separated into two basic sub-models, avascular and angiogenesis. The avascular sub-model is primarily based of Fickian diffusion of nutrients into the tumor. While the angiogenesis sub-model is based on the diffusion and chemotaxis of active sprout tips into the tumor. These two portions of the models allow the effects of microvessels on nutrient concentration within the tumor, as well as the effect of the tumor in driving angiogenesis, to be examined. The results of the model have been compared to experimental measurements of tumor growth over time in animal models, and have been found to be in good agreement with a correlation coefficient of (r2=0.98).Master of Science
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Williams, Carl David. "Personal Projects and Alcohol Use: An Integrative Social Cognitive Approach." Thesis, Virginia Tech, 1999. http://hdl.handle.net/10919/42652.
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Despite the potential for unwanted consequences, college students continue to drink at high rates. Greater than 80% of college students drink alcohol and about 40% engage in occasions of heavy episodic drinking. Heavy episodic drinking among college students is associated with increased instances of verbal confrontations, physical fights, unprotected sex, vandalism, and driving while under the influence.
From a dynamic ecological perspective, goals represent a context in which drinking and all other endeavors occur, as well as a third social cognitive variable worthy of investigation in alcohol studies. As a technology for studying goal constructs, personal projects (Little, 1983; 1987; 1998) are embodiments of desired attainments an individual is trying to actualize. The present study examined the ability of goal constructs (i.e., personal project attributes)to explain drinking variance, both in combination and beyond known social cognitive determinants of alcohol use.
In a cross-sectional sample of 104 male and 96 female college students, results indicated that alcohol self-efficacy was the strongest predictor of alcohol consumption (b = -.38; p < .01), followed by goal involvement (b = -.23; p < .01) and negative drinking expectancies (b = -.12; p < .05). Positive drinking expectancies (b = -.42; p < .01) and goal efficacy (b = .15; p < .05) were significant determinants of alcohol efficacy. The complete model explained 33% of the variance in drinking, as measured by a 90-day timeline follow-back. The unique and indirect contributions of goal involvement are major findings of the study, indicating the viability of a dynamic ecological approach within the SCT framework.Master of Science
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Geers, Allison Renee. "Inhabiting Structure: An Elementary School Campus." Thesis, Virginia Tech, 2012. http://hdl.handle.net/10919/42651.
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Trefren, Jennie Lee. "The Emergence of the Wyoming Core Area Strategy: "The Sage Grouse Rebellion"." Thesis, Virginia Tech, 2012. http://hdl.handle.net/10919/42650.
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This research sought to explain the emergence of the Wyoming Core Area Strategy (WCAS), a state-based Greater Sage Grouse conservation plan. It presents a theoretical framework that is
based on and adds nuance to the Advocacy Coalition Framework (ACF). The hypothesis this
study explored was: if a subsystemâ s jurisdiction is threatened by a hierarchically superior subsystemâ s policy outputs and this jurisdiction is necessary to meet the threatened subsystemâ s
goals, then policy change may occur as a result of a strategy by the agents in the threatened
subsystem. The data used to examine the hypothesis included expert interviews, historical
documents, and interviews from media sources (secondary source interviews). The hypothesis
was supported; the WCAS emerged because the Endangered Species Act listing outputs within
the Species Conservation Policy Subsystem threatened the Wyoming Land Use Policy (WLUP)
Subsystemâ s jurisdiction, which was necessary to meet the WLUP Subsystemâ s economic and lifestyle goals; the Governor of Wyoming drove the development and enactment of the WCAS as a strategy to retain jurisdiction. The research demonstrated that in order to fully account for the WCASâ s emergence, a less mechanistic view of the framework, one that accounts for the ability
of agents in a subsystem to act strategically, was needed. The research also demonstrated that the Greater Sage Grouse conservation benefited from the ESA listing process despite its warranted
but precluded listing status. The time frame the research explored was 2002 through March 2012.Master of Arts
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Zheng, Hanguang. "Processing and Properties of Die-attachment on Copper Surface by Low-temperature Sintering of Nanosilver Paste." Thesis, Virginia Tech, 2012. http://hdl.handle.net/10919/42658.
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As the first level interconnection in electronic packages, chip attachment plays a key role in the total packaging process. Sintered nanosilver paste may be used as a lead-free alternative to solder for die-attachment at sintering temperature below 300 °C without applying any pressure. Typically, the substrate, such as direct bond copper (DBC) substrates, has surface metallization such as silver or gold to protect the copper surface from oxidation during the sintering process. This study focused on developing techniques for die-attachment on pure copper surface by low-temperature sintering of nanosilver paste. One of the difficulties lies in the need for oxygen to burn off the organics in the paste during sintering. However, the copper surface would oxidize, preventing the formation of a strong bond between sintered silver and copper substrate.
Two approaches were investigated to develop a feasible technique for attachment. The first approach was to reduce air pressure as a means of varying the oxygen partial pressure and the second approach was to introduce inert gas to control the sintering atmosphere. For the first method, die-shear tests showed that increasing the oxygen partial pressure (PO2) from 0.04 atm to 0.14 atm caused the bonding strength to increase but eventually decline at higher partial pressure. Scanning electron microscopy (SEM) imaging and energy dispersive spectroscopy (EDS) analysis showed that there was insufficient oxygen for complete organics burnout at low PO2 condition, while the copper surface was heavily oxidized at high PO2 levels, thus preventing strong bonding. A maximum bonding strength of about average 8 MPa was attained at about PO2 = 0.08 atm. With the second method, the die-shear strength showed a significant increase to about 24 MPa by adjusting the oxygen exposure temperature and time during sintering.
The processing conditions necessary for bonding large-area chips (6 mm à 6 mm) directly on pure copper surface by sintering nanosilver paste was also investigated. A double-print process with an applied sintering pressure of less than 5 MPa was developed. Die-shear test of the attached chips showed an average bonding strength of over 40 MPa at applied pressure of 3 MPa and over 77 MPa under 12 MPa sintering pressure. SEM imaging of the failure surface showed a much denser microstructure of sintered silver layer when pressure was applied. X-ray imaging showed a bond layer almost free of voids. Because the samples were sintered in air, the DBC surface showed some oxidation. Wirebondability test of the oxidized surface was performed with 250 μm-diameter aluminum wires wedge-bonded at different locations on the oxidized surface. Pull test results of the bonded wires showed a minimum pull-strength of 400 gram-force, exceeding the minimum of 100-gf required by the IPC-TM-650 test standard.Master of Science
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Nash, Whitney Laine. "Long-Term Effects of Rock Type, Weathering and Amendments on Southwest Virginia Mine Soils." Thesis, Virginia Tech, 2012. http://hdl.handle.net/10919/42657.
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This study measured the effects of spoil type and amendments on Appalachian mine soil properties over time. The Controlled Overburden Placement Experiment was installed in 1982 in two parts, the Rock Mix (RM) Experiment compares mixes of sandstone (SS) and siltstone (SiS) spoils while the Surface Amendment (SA) Experiment compares a fertilized control (CON), sawdust (SD at 112 Mg ha-1), topsoil (TSâ 15 cm), and biosolids (BS) at 22, 56, 112 & 224 Mg ha-1. Both experiments were sampled in 2008 and compared with historical data. After 26 years, all RM treatments had higher silt+clay and decreased sand. Mine soil pH and electrical conductance (EC) were lower in high SS spoils and overall pH was lower and EC higher in surface layers. Fe-oxides increased over time and adversely affected extractable P. Exchangeable cations and total N increased in all treatments. Annual C-sequestration rates were 0.51 Mg ha-1 for 1:1 SS:SiS and 0.32 Mg ha-1 for SiS. In the SA experiment, extractable P and exchangeable cations increased over time in organically amended plots. The CON and TS sequestered C at 0.54 Mg ha-1 and 0.87 Mg ha-1 annually while higher BS and SD treatments lost C, but mobilized significant C into their subsoils. In the SA, an apparent C retention maximum of 30-35 Mg ha-1 was noted. Overall, rock type and amendment effects were still evident after 26 years and the long-term benefits of organic amendments were reflected in sustained higher C, exchangeable cations, total N and P levels.Master of Science
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Stine, Melanie Brooke. "Vegetation and Soil Patterns at a Mountain Wetland Ecotone." Thesis, Virginia Tech, 2009. http://hdl.handle.net/10919/42654.
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This study analyzes tree, soil, and microtopographic patterns present within the Cranberry Glades, a bog wetland complex located in the mountains of West Virginia. The Cranberry Glades are comprised of four open bog meadows, which provide unique habitat to several rare and endangered plant species. However, these meadows are filling in with trees and alder. This research is a study on the factors that may be involved in the processes and patterns influencing tree encroachment into the bog meadows across the open meadow â bog forest ecotone. To determine the patterns of infilling and the potential relationships among the trees, microtopography, and soil conditions, I collected and analyzed data on each of these factors within nine belt transects located across the ecotone. I gathered tree data on the following: location within transect, species, diameter at breast height or diameter at ground level, height class, associated microtopography, and growing conditions on 1,389 trees. Soil samples were gathered across the ecotone and analyzed for percent moisture, pH, and various nutrients and metals. I assessed historical aerial photographs to gain a temporal history on the patterns of infilling. The results indicate that trees decrease in density across the ecotone towards the peatland interior, and that trees are likely to be growing on hummock features and within tree islands. Soil properties resulted in mixed conclusions. The aerial photograph assessment revealed that trees and alders have been steadily encroaching into the open peatlands for at least the past 52 years. The finding of this research lend to increased knowledge on southern peatlands, wetland succession, and the Cranberry Glades Botanical Area.Master of Science
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Ada, Tchoukou Julie Ynes. "Legal Development and the Democratization of Human Rights in Post-modern Africa: A Case for the Legal Regulation of Cultural Violence Against Girls." Thesis, Université d'Ottawa / University of Ottawa, 2021. http://hdl.handle.net/10393/42652.
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The problem of cultural violence against girls in Nigeria has been discussed at length. A number of scholars have conducted empirical studies, others developed theories and tools to be used in measuring and monitoring improvement on eliminating specific cultural practices. This scholarship is vitally important. They launch feminist and other anthropological works into an arena of anti-violence work which without a doubt have a significant impact and far-reaching repercussions for girls who experience violence in Nigeria. Yet, despite the systemic change over the past years, the problem of violence against girls in Africa, more specifically Nigeria, is still persistent within cultural communities. Building on the important foundational works of these authors, my dissertation analyses this problem from a different perspective. This thesis identifies several governance gaps within the Nigerian legal framework that needs to be addressed before existing legal mechanisms can adequately address the problem of violence against girls. To ensure a proper examination of the different dimensions and changing patterns of cultural violence against girls, the dissertation focuses on the practice of child marriages within Muslim communities in Northern Nigeria. The complexity of the issues addressed in this dissertation required a variety of theoretical tools to unpack the different fields of inquiry. The dissertation uses a critical legal studies and feminist framework in studying the problem of cultural violence against girls in Nigeria. It also uses textuality, a method of inquiry within Dorothy Smith’s feminist socio-legal methodology, to investigate the text-based organization of social policy in Nigeria to ultimately reveal a legal and political system used as an instrument for consolidating power and legitimizing anti-women principles as traditional values. Using these tools, the thesis analyzed the complexity of the problem of cultural violence through a focus on co-existing institutional frameworks, that is, formal and informal legal structures and the roles they play in shaping the experiences of girls within cultural communities.
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Yiran, Li. "Black Titanium Dioxide: Synthesis, Characterization and Applications." Thesis, Université d'Ottawa / University of Ottawa, 2021. http://hdl.handle.net/10393/42653.
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The exploration and application of nanomaterials have been attracting researchers’ attention in recent decades. Nanocatalysts, as one of the very important classes of nanomaterials, have been developed for several generations. Nanotechnology makes light be possibly utilized in catalysis rather than only heat and allows multifunctional parts to be assembled in one catalyst. The TiO2 (as the representative of hetero-photocatalyst) and iron-based magnetic catalysts (as multifunctional catalyst) will be discussed in detail in this thesis.
The first chapter will introduce the background of catalysts and nanomaterials. TiO2, especially black TiO2, will be mainly discussed in the aspects of properties, synthesis, and applications. Another part of the chapter will talk about the separation-friendly catalyst – magnetic heterogenous catalysts’ synthesis and applications.
Chapter 2 focuses on the synthetic route we used and the characterization of black TiO2 catalysts and magnetic catalysts. Both anatase and rutile black TiO2 catalysts were successfully prepared originally from Degussa P25 using the ethanol reduction method. The re-whitening treatment was also examined on both black TiO2 catalysts. All catalysts were characterized and compared by diffuse reflectance (DR), powder X-ray diffraction (XRD), and X-ray photoelectron spectroscope (XPS). Tauc plot results show that black TiO2 has smaller band gap than white TiO2. XPS revealed the existence of surface -OH species and Ti3+ in black TiO2. Furthermore, these two characterization techniques and XRD all proved that the blackening and re-whitening treatment does not change the crystalline phase of the catalysts, and the blackening treatment is reversible. For magnetic catalysts, we synthesized magnetic Fe2O3, Fe2O3@TiO2, copper/iron oxide magnetic TiO2, and black magnetic catalysts. Other than diffuse reflectance spectroscopy, Raman spectroscopy, scanning electron microscopy, and energy-dispersive X-ray elemental mapping analysis were used for determining the light-absorption properties, composition, and morphology of all synthesized magnetic catalysts. In addition, the magnetic separation was also achieved by simply applying an external magnetic field.
Chapter 3 will discuss and compare the decarboxylation reaction activities of pristine, black, and re-whited TiO2 catalysts. The reactions were carried under the UV, blue, red, green, and white light irradiation. Unfortunately, the reaction was found only working under UV-light irradiation. The best solvent was dioxane which may be due to the proton affinity of the oxygen atom in dioxane molecule, which facilitates the deprotonation of the carboxylic acid. The optimal catalyst amount was found as 10 mg per 5 mL reaction mixture, and the kinetic study shows that the reaction is a pseudo-first order reaction. It is a pity that the performance of black TiO2 catalysts is worse than the pristine and re-whitened TiO2.
Chapter 4 will talk about the sol-gel synthesized magnetic catalysts. These catalysts were used for aldehyde-alkyne-amine (A3) coupling reaction. The reaction was tested by light irradiating or traditional heating, but only heating can make the reaction proceed. Results also show that the coupling reaction requires copper to finish. The best solvent was found as toluene and the optimal reaction time is 6 hours at 120 ̊C. Sadly, the reactivity of copper/iron oxide magnetic TiO2 decreases a lot after three reaction cycles because of the copper leaching problem.
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Pan, Wen. "The Morphological and Molecular Basis of Hypoxic Chemotransduction and Transmission in Neuroepithelial Cells of Zebrafish (Danio rerio)." Thesis, Université d'Ottawa / University of Ottawa, 2021. http://hdl.handle.net/10393/42656.
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O2 is essential to many animals. Vertebrate species rely on specialized chemoreceptive cells to “sense” O2 changes in order to make appropriate physiological adjustments to maintain homeostasis. Aquatic vertebrates are especially prone to fluctuations in environmental O2 availability and have adapted respiratory and cardiovascular responses to cope with hypoxia, a condition characterized by a low level of O2. In teleost fish, such as zebrafish (Danio rerio), neuroepithelial cells (NECs) present in the gill epithelium are the putative O2 chemoreceptors that mediate hypoxic signals to facilitate such responses. NECs contain the neurotransmitter serotonin (5-HT) and exhibit extensive neural innervation. They are sensitive to hypoxia, as isolated NECs undergo membrane depolarization and vesicular recycling when exposed to acute hypoxia. Other neurotransmitters, such as dopamine (DA), acetylcholine (ACh) and adenosine triphosphate (ATP), have also been suggested to regulate the ventilatory responses to hypoxia. However, the presence of these neurotransmitters or targeted receptors in gills are not well explored. In my PhD studies, I identified cellular and molecular components involved in chemotransduction and transmission for hypoxic signals in NECs of zebrafish through various experimental approaches. First, using the existing transgenic zebrafish line, ETvmat2:GFP, I established a method to reliably identify gill NECs. I showed that these cells could be distinguished based on their high expressions of the reporter gene GFP in vitro, in situ and in cytometric analyses. GFP-labeled NECs also displayed increases in cell size and population in response to chronic hypoxia. Second, using immunohistochemistry and confocal microscopy, I localized cholinergic cells and dopaminergic cells, sources of DA and ACh secretion respectively, in the gills. These cells present distinct populations from serotonergic NECs. In addition, I found purinergic P2X3 receptors, targets of ATP, to be present in gill NECs and other iv neurons. These findings offered different avenues in which hypoxic signals could be regulated. Lastly, using the single cell RNA sequencing approach, I determined the transcriptomic profile of NECs. NECs showed high expressions of G protein regulators, similar to those found in the mammalian O2 chemoreceptors, and they expressed high levels of genes likely to be involved in O2 signal transduction and transmission. Within the gill cell atlas generated using the single cell sequencing data, I localized a number of 5-HT, ACh and DA receptors in various gill cell populations, providing evidence for the 5-HT fast synaptic excitatory neurotransmission, paracrine and endocrine regulation of the signal. The studies overall provide compelling evidence to support a role for NECs as the primary O2 chemoreceptor in zebrafish, and further our understanding of signal modulation in the hypoxic response.
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Lim, Sean. "The Relationship Between Metabolic Circumstance and Epigenetic Acetylation in Myoblast Fate and Function." Thesis, Université d'Ottawa / University of Ottawa, 2021. http://hdl.handle.net/10393/42659.
Full textAbstract:
Muscle tissue is grown and maintained by muscle stem cells termed satellite cells. Activated satellite cells become myoblasts, which must proliferate then differentiate into functional muscle. This process, known as myogenesis, is controlled by a cascade of epigenetic regulatory events. One facet of this regulation is histone acetylation, which can be influenced by the availability of metabolites within a cell. In this study, the ability of glucose, pyruvate, or glutamine to change histone acetylation levels in cultured myoblasts was investigated. Changing concentrations of glucose or pyruvate had no effect but decreasing the availability of glutamine in cell culture from 2mM to 0.2mM resulted in proliferating myoblasts accruing a hyperacetylated histone phenotype. However, when the same concentration of glutamine was used on differentiating myoblasts the hyperacetylated phenotype was lost and no change to differentiation was observed. This study demonstrates the potentials and limitations of altering epigenetic acetylation with metabolic circumstance. -- Le développement du tissu musculaire est soutenu par les cellules souches musculaires, communément appelées cellules satellites. Les cellules satellites activées se transforment en myoblastes qui doivent ensuite proliférer et se différencier en muscle fonctionnel. Ce processus, connu comme myogenèse, est contrôlé par une cascade de régulation épigénétique. Un aspect de ce processus est l’acétylation d’histones, qui peut être influencée par la disponibilité de métabolites dans la cellule. Dans cette étude de cas, la capacité du glucose, pyruvate, ou glutamine à changer les niveaux d’acétylation d’histones a été examinée. Le changement des concentrations de glucose ou de pyruvate n’a généré aucun effet, mais la diminution de la disponibilité de la glutamine dans la culture cellulaire de 2mM à 0.2mM a eu pour résultat une prolifération de myoblastes présentant un phénotype d’histones hyper-acétylées. Pourtant, quand la même concentration de glutamine a été utilisée pour différencier les myoblastes, le phénotype hyper-acétylé n’a pas été observé et aucun changement de différenciation n’a pu être détecté. Cette étude démontre le potentiel et les limites des modifications de l’acétylation épigénétique selon les circonstances métaboliques.
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Sommerfelt, Knut Magnus. "Offshore Wind Power in the North Sea : Grid Integration of 1000 MW Offshore Wind Power into the Norwegian Power System." Thesis, Norges teknisk-naturvitenskapelige universitet, Institutt for elkraftteknikk, 2008. http://urn.kb.se/resolve?urn=urn:nbn:no:ntnu:diva-12868.
Full textAbstract:
Norway has great potential for offshore wind power, but the depths just outside the coast probably make floating wind turbines necessary. In order to use todays technology for offshore wind turbines with foundations on the seabed, water depths cannot be much larger than 60 meters. It is possible to install the wind turbines at such depths, but the distance to these areas make AC cable transmission difficult because of the reactive power production in the cables. VSC HVDC is a technology well suited for offshore wind power, and HVDC Light is now commercially available for rating up to 1174 MW. Theory for VSC HVDC in systems in general is given first in the thesis. The case for this thesis is grid integration of a 1000 MW offshore wind farm into the Norwegian power system.PSS/E was used in simulations of grid integration of the offshore wind power. Two possible connection points in the south of Norway were found based on load flow simulations; Feda and Kårstø. Only a load flow situation with peak load and production in the isolated Norwegian power system was provided. Different load flow situations for the two connection points were established in order to investigate the dynamic response at the connection points for situations with lower load and production.A case with two sets of 100 km AC cables was used for the dynamic simulations as well as a HVDC Light link with a 600 km cable. SVCs were added at the connection point for the case with AC cable connection in order to fulfil the requirement for capacitive and inductive power factor at the connection point to the grid for wind power. No such compensation of reactive power is necessary for HVDC Light, as the converter can adjust the power factor. The voltage at the connection points is 300 kV. Dynamic simulations were done based on the fault ride through requirement from the Norwegian TSO Statnett for power plants connected to voltage level higher than 200 kV.Different disturbances were done in the power system onshore close to the two connection points. The simulations done with AC cables and SVCs for reactive power compensation showed that the power system was not able to return to a stable operating point in all the simulations. With HVDC Light on the other side, simulations showed that the voltage at the connection points recovered to the pre fault value in all the simulations. The voltage recovery was within the voltage profile defined in the fault ride through requirement, and the wind turbines had to stay connected.The wind farm was modelled as one equivalent generator offshore, and a standard PSS/E induction generator model was used. For the case with HVDC Light, the voltage offshore was practically unaffected by the disturbances onshore. The energy produced during the fault was stored as rotational kinetic energy in the wind turbine in order to avoid the DC voltage to increase drastically. This is an approximation done in this thesis. Wind projects planned with HVDC Light will have a DC chopper. A fault onshore will not affect the wind farm, as the power produced during the fault is dissipated in the DC resistance.
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Moon, Merchant Vickie V. "A longitudinal trend study of a university-based teacher induction program: observable behaviors of urban teachers and their perceptions of program components five years after participation." Texas A&M University, 2005. http://hdl.handle.net/1969.1/4265.
Full textAbstract:
This longitudinal trend study (Gall, Borg & Gall, 1996) examined the
effectiveness of a one-semester university-based teacher induction program as compared
to a two-semester university-based teacher induction program based on the observation
scores of classroom teaching behaviors urban novice teachers exhibited during the first
year of teaching. These scores were further analyzed in relation to the socio-economic
level of the school and the grade level taught. Additionally, the study explored the past
participantsâ perceptions of the teacher induction program components of a one-semester
program and a two-semester program during their fifth year of teaching. Their
perceptions were also examined in relation to the socio-economic level of the school and
the grade level taught.
The study examined the observation scores of classroom teaching behaviors of 145
urban novice teachers participating in either a one-semester or two-semester universitybased
teacher induction program. The urban novice teachers demonstrated growth over time as measured by the first and final observation scores of classroom teaching
behaviors. However, the length of the university-based teacher induction program did
not affect the observation scores of classroom teaching behaviors. Further, neither the
socio-economic level of the school nor the grade level taught affected the observation
scores of classroom teaching behaviors.
Although the three components of the university-based teacher induction program
received high means, 82 past participants of a one-semester or a two-semester teacher
induction program responding to the Teacher Induction Program Participant Survey
(TIPPS) recognized formative observation as the most effective component. Peer
support and professional development were perceived second and third respectively. No
statistical significant differences of the one-semester or two-semester past participantsâÂÂ
perceptions of peer support, professional development or formative observation were
found related to the socio-economic level of the school or the grade level taught.
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Villegas, González Mario Jesús Jr. "Valor de las exploraciones neurotológicas en el diagnóstico, localización y seguimiento de los neurinomas del acústico." Doctoral thesis, Universitat Autònoma de Barcelona, 2004. http://hdl.handle.net/10803/4265.
Full textAbstract:
El neurinoma del acústico (NA) es una neoplasia benigna que se origina de la rama vestibular del VIII par craneal en el conducto auditivo interno (CAI) y en el ángulo pontocerebeloso (APC). Constituye el 8 al 9% de las tumoraciones intracraneales y el 80 al 90% de las tumoraciones del APC. Los estudios epidemiológicos demuestran que la incidencia clínica anual de NA varía de entre el 0.7 a 1 por cada 100,000 habitantes. El crecimiento de estas tumoraciones es impredecible por lo que el tratamiento quirúrgico es requerido en la mayoría de los casos. Los reportes de la literatura señalan la importancia de diagnosticar a las tumoraciones tempranamente, debido a la relación existente entre el menor tamaño tumoral y una mejor evolución postoperatoria.Consideramos que el desarrollo de los NA en el trayecto del VIII par craneal (desde el fondo del CAI hasta el APC) estará relacionado con los síntomas de presentación y los síntomas al momento del diagnóstico, y que estas tumoraciones producirán alteraciones específicas durante la realización de las exploraciones neurotológicas que harán sospechar al clínico de la existencia del NA, con lo cual se podrá realizar un diagnóstico temprano de la tumoración.
Para estudiar las características de los NA en diferentes estadios incluimos a 133 pacientes, los cuales fueron divididos en tres grupos en relación al tamaño de los neurinomas del acústico confirmados a través de la resonancia magnética nuclear (RMN):
- Grupo I: Tumores intracanaliculares puros
- Grupo II: Tumores < a 2.5 cm en APC o tamaño mediano en APC
- Grupo III: Tumores > a 2.5 cm en APC o tamaño grande en APC
Todos los pacientes fueron sometidos a las siguientes exploraciones neurotológicas:
- Audiometría tonal y vocal
- Potenciales evocados auditivos de tronco cerebral
- Videonistagmografía y pruebas calóricas
- Electroneuronografía facial
En esta tesis estudiamos los síntomas que refirieron los pacientes durante su evolución hasta el momento del diagnóstico según el grupo tumoral y realizamos una revisión bibliográfica de cada síntoma en su relación con los NA. Así mismo, estudiamos las bases fisiológicas y anatómicas en las que las exploraciones neurotológicas están fundadas para determinar la relación existente entre las alteraciones encontradas durante la realización de los estudios y los diferentes grupos tumorales, con el fin de diagnosticar a los NA en una fase más temprana, con la consiguiente reducción de la morbilidad, la preservación del nervio facial y la conservación de la audición útil.
Acoustic neuromas (AN) are benign tumors that arise form the vestibular bundle of the eighth cranial nerve in the internal auditory canal (IAC) and cerebellopontine angle (CPA). Represent eight to nine percent of intracranial tumors and account for 80% to 90% of tumors of the CPA. The epidemiologic studies show a yearly clinical incidence of diagnosed acoustic neuroma 0,7 to 1 per 100,000 habitants. The growth great of these tumors are unpredictable, thus surgical resection is required in most cases of AN. The literature shows the importance of make an early diagnosis due the relation between the smaller tumor size and the better postoperative evolution.
We have considered that the developed of the AN in the eighth cranial nerve (from fundus of the IAC to CPA) is related with the evolution of the symptoms, and these tumors will produce specifics alterations in the neurotologic explorations that could be suspect the existence of AN, made possible an early diagnosis of the tumor.
For the study of the characteristics of the AN tumor in different stages, we included 133 patients. These patients were divided in three groups according to the size of the tumor in the magnetic resonance imaging (MRI):
- Grupo I: intracanalicular tumors (exclusively)
- Grupo II: Tumor < 2.5 cm in CPA o medium size in CPA
- Grupo III: Tumor > 2.5 cm in CPAC o large size in CPA
All patients underwent thorough neurotologic evaluation, wich included:
- Pure-tone audiometry and speech audiometry
- Auditory brainstem response
- Videonystagmography
- Facial electroneuronography
- Magnetic resonance imaging (MRI)
The aim of this thesis is to study the symptoms referred by the patients during their evolution until the diagnosis of AN could be done and make a bibliographic revision of each symptom and its relation with the tumor. Likewise, we study the anatomical and physiological basis of the neurotologic explorations to determine the relationship among the pathological findings discovered during the realization of the procedure and the tumoral gorup, with the aim of an early detection of the AN tumor, in order to reduce morbidity with the preservation of the facial nerve and conservation of the serviceable hearing.
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Jayatilake, Dimanthi. "A novel quantitative trait loci for fusarium head blight resistance in wheat chromosome 7A." Thesis, Manhattan, Kan. : Kansas State University, 2010. http://hdl.handle.net/2097/4265.
Full text
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Krakenberg, Jasmin. "Gothic art and German modernism Max Beckmann and "Transzendente objektivitat" /." Diss., Columbia, Mo. : University of Missouri-Columbia, 2005. http://hdl.handle.net/10355/4265.
Full textAbstract:
Thesis (M.A.)--University of Missouri-Columbia, 2005.The entire dissertation/thesis text is included in the research.pdf file; the official abstract appears in the short.pdf file (which also appears in the research.pdf); a non-technical general description, or public abstract, appears in the public.pdf file. Title from title screen of research.pdf file viewed on (December 13, 2006) Includes bibliographical references.