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Pages
- Title
- THE CONTEXTUAL-SCENARIO FRAMEWORK FOR REPRESENTING SUBJECTIVE EXPERIENCE
- Creator
- Swanson, Eric
- Date
- 2013, 2013-05
- Description
-
No abstract
PH.D in Design, May 2013
- Title
- Efficiency test of a four cylinder four cycle twenty horse power automobile gasoline engine
- Creator
- Smith, C. U.
- Date
- 2009, 1907
- Publisher
- Armour Institute of Technology
- Description
-
http://www.archive.org/details/efficiencytestof00smit
Thesis (B.S.)--Armour Institute of Technology; Bibliography: leaf 41
- Title
- ELECTROCHEMICAL CONTINUOUS AND AB INITIO DFT MODELING OF ELECTRODE REACTIONS IN PEM FUEL CELLS, AND LI-ION AND MAGNESIUM BATTERIES
- Creator
- Ramanathan, Mayandi
- Date
- 2013, 2013-07
- Description
-
Electrochemical energy conversion and storage systems are set to play a major role in the scheme of providing clean and renewable energy to...
Show moreElectrochemical energy conversion and storage systems are set to play a major role in the scheme of providing clean and renewable energy to the growing energy demands, both in the nearby and long-term future. PEM fuel cells are the widely tested energy conversion devices with hydrogen as fuel and air as oxidant. Li-ion batteries are commercialized for short and medium range energy demands. But for fulfilling the long range energy demands, research in some new technologies such as Li-air, Magnesium and Sodium batteries are in progress. Magnesium batteries have huge potential to be a high energy density battery suitable for long range electric vehicles and electrical grid energy storage. In PEM fuel cells, Oxygen reduction reaction is the performance limiting factor due to the sluggish reaction kinetics and expensive, but relatively stable Pt catalyst. In the present study, combined DFT modeling and experimental annealing procedure is being employed to improve the ORR activity of Pd by alloying with transition metal elements such as Ni, Cu and Fe. In Li-ion battery, LiFePO4 is the widely commercialized cathode material, but it suffers its limitation of possessing poor electronic conductivity, which affects the cell performance at high discharge rates. A simple isothermal, one-dimensional John Newman Li-ion battery model is being employed to study the effects of changes in LiFePO4, carbon and binder composition towards changes in electrode porosity, electrical conductivity and cell capacity. With the help of modeling results, an optimum composition zone is located for optimizing the high rate performance. In Magnesium batteries, a modified isothermal, one-dimensional John Newman battery model was employed to study the characteristics of the Mg intercalation reactions, predict the performance of the Bi anode electrode and also understand the underlying phenomena and properties that dictate the characteristics of the Mg intercalation in Bi electrode.
PH.D in Chemical Engineering, July 2013
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- Title
- PHOTOCONDUCTIVE SWITCH IMPLEMENTED WITH GALLIUM ARSENIDE ON SILICON NITRIDE FOR COPLANAR WAVEGUIDE BASED TERAHERTZ SPECTROMETER
- Creator
- Fu, Xiaohuan
- Date
- 2015, 2015-12
- Description
-
Over the years, pulsed terahertz (THz) time domain spectroscopy has attracted a lot of interest since it can not only measure the intensity of...
Show moreOver the years, pulsed terahertz (THz) time domain spectroscopy has attracted a lot of interest since it can not only measure the intensity of the transient electric eld but also determine the amplitude and phase of the spectral components that make up the pulse. This provides a convenient method to obtain the molecular network information of chemical or biological samples. Signi cant e orts have been directed towards free space spectroscopy in which THz pulses travel in free space between photoconductive transceivers. Due to di raction limit, the resolution is insu cient for many applications and it results in extreme power requirements or low power densities of the probe pulse. To overcome this issue, we propose a planar THz spectrometer which uses the same photoconductive excitation and detection mechanism as free space spectroscopy, but the excited THz pulses are directly coupled into lithographically de ned coplanar transmission lines. To reduce the power loss in the substrate, a thin lm with lower permittivity is employed to replace the conventional silicon substrate at the location where the coplanar waveguide is fabricated. To obtain high sensitivity, sample can be directly placed on the coplanar waveguide for tight coupling of the eld. Conceptual design and EM simulations have been completed and a variety of experimental studies have been carried out at Argonne National Laboratory to understand the fundamentals of coplanar waveguide. The fabrication of the coplanar waveguide prototype have been conducted at Northern Illinois University. The challenge of building a photoconductive switch with LTG-GaAs on Si3N4 was encountered and an innovative wafer bonding technique was discovered. Several wafer treatments prior to and after wafer bonding have been demonstrated to improve the bonding strength and reduce the defects. A standard pump-probe optics setup has been built at DePaul University and the photoconductive switch have been tested with femtosecond laser. The results con rmed that the photoconductive switches are functioning as design and the device system is ready for THz spectroscopy application. The historical overview of THz spectroscopy research and fundamentals of coplanar waveguide and photoconductive switches are presented in Chapter 1-3, followed by EM simulation, conceptual design in Chapter 4. The details of microfabrication process and the testing results are discussed in Chapter 5 and 6. The project is summarized in Chapter 7.
Ph.D. in Electrical Engineering, December 2015
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- Title
- REVISITING THE URBAN BLOCK IN THE LIGHT OF CLIMATE CHANGE A CASE STUDY OF BUDAPEST
- Creator
- Gal, Csilla Viktoria
- Date
- 2014, 2014-07
- Description
-
Since the beginning of the twentieth century, the urban block configuration of free-standing buildings has been deemed superior to other built...
Show moreSince the beginning of the twentieth century, the urban block configuration of free-standing buildings has been deemed superior to other built forms, as it provided the necessities of modern healthy living: sunlight and fresh air. In light of climate change, the dissertation aims to reevaluate these long held beliefs and to reintroduce microclimate as an urban design consideration. The study takes four metropolitan block typologies of Budapest as cases to clarify the microclimate influence of key urban design parameters by means of a numerical simulation study. The effects of built form, orientation, vegetation and facade properties are evaluated for a typical summer day. The cases are assessed on the basis of diurnal potential air and mean radiant temperatures within the urban canopy layer. Numerical modeling is performed by ENVI-met and analysis is conducted with MATLAB. The findings indicate that built form and vegetation are key factors governing the microclimate. During the day, intraurban cool island develops between dense configurations and in tree-shaded urban canopies. Orientation is decisive in configurations with large open spaces, where east-west alignment corresponds with peak radiant and air temperatures. Apart from albedo, facade properties have little effect on the microclimate. The rise of air temperature with facade albedo is the outcome of canopy floor heating, resulting from the increased ratio of reflected shortwave radiation. A short-term field experiment was conducted in Budapest to complement the numerical simulation study and to evaluate ENVI-met. The measurement campaign utilized six air temperature and humidity loggers. Additionally, wind speed, air temperature and humidity were recorded at the pedestrian level during an anticyclonic period. In courtyards, thermal stratification developed by day with cool island intensities up to 7 C. In the case of open configurations, neither cool island, nor stratification was observed. The comparison of measured and predicted air temperatures revealed the strengths and weaknesses of the numerical model. In general, predicted temperatures had a decreased diurnal range with maximum values systematically underestimated. ENVI-met also failed to reproduce the thermal stratification in courtyards. Despite these shortcomings, the predicted trends and the relative microclimate differences between the configurations agreed with observations reasonably well.
Ph.D. in Architecture, July 2014
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- Title
- THE ASSOCIATIONS AMONG EMOTIONAL EATING, GENDER, BMI, AND RUMINATION
- Creator
- Gabelman, Rachel Beth
- Date
- 2017, 2017-07
- Description
-
The purpose of this study was to gain a better understanding of the roles of gender, body mass index (BMI), and rumination in the relation of...
Show moreThe purpose of this study was to gain a better understanding of the roles of gender, body mass index (BMI), and rumination in the relation of negative affect (NA) and emotional eating (EE). The following associations were proposed: (1) NA is positively associated with EE, (2) rumination both moderates and (3) mediates the association between NA and EE, (4) gender moderates the association between NA and emotional eating, and (5) EE mediates the association between NA and BMI. Participants consisted of average, overweight, and obese, males (n = 140) and females (n = 152) from both community and university settings. Participants completed self-report questionnaires, including the Binge Eating Questionnaire, Positive and Negative Affect Scale, Dutch Eating Behavior Questionnaire, and Ruminative Response Questionnaire. Results agreed with previous findings that NA positively correlated NA was positively associated with EE. Results indicated that rumination moderated the association between NA and EE; however rather than greater rumination strengthening this association, it led to a weaker association between NA and EE. Rumination mediated the association between NA and EE, and EE mediated the association between NA and BMI. Lastly, gender did not moderate the association between NA and EE. Results indicate the importance of rumination in those with a tendency to emotionally eat. They also point to the impact of EE on BMI, and suggest further studies should examine whether an association exists between EE and weight gain. In addition, results indicate similarities between men and women in regard to emotionally eating in response to NA.
Ph.D. in Psychology, July 2017
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- Title
- NUMERICAL MODELING AND ANALYSIS OF CAVITATION IN WATER AND LASER-INDUCED PLASMA AMPLIFICATION FOR MICROMACHINING APPLICATIONS
- Creator
- Dabir-moghaddam, Navid
- Date
- 2017, 2017-05
- Description
-
Machining processes are needed in many industrial areas. Laser-based machining often has the advantages such as high spatial resolution, no...
Show moreMachining processes are needed in many industrial areas. Laser-based machining often has the advantages such as high spatial resolution, no mechanical tool wear, etc., and has current and potential applications in many areas. The objective of this research work is to conduct physics-based modeling studies to help the understanding of some physical processes relevant to two novel laser-based machining processes: (i) the Ultrasound-assisted water-confined laser micromachining (UWLM) process (proposed by Prof. Benxin Wu), and (ii) the Dual-pulse laser ablation and plasma amplification (LAPA) process for drilling microholes with variable diameters at different depths (proposed by Prof. Yung C. Shin). The models are developed by numerically solving the relevant governing equations, and are tested by comparing with related experimental measurements when available. The specific topics that have been studied include: (i) Bubble evolution close to a solid boundary; (ii) Ultrasound propagation and cavitation in water; (iii) Laser amplification of pre-existing plasma in a microhole and plasma interaction with the hole sidewall.
Ph.D. in Mechanical and Aerospace Engineering, May 2017
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- Title
- EFFICIENCY OF PATENT CONTRACTS
- Creator
- Liang, Shao-huai
- Date
- 2014, 2014-05
- Description
-
This thesis attempts to analyze the incentive compatible (IC) region for the royalty contract in an innovation context. It also describes the...
Show moreThis thesis attempts to analyze the incentive compatible (IC) region for the royalty contract in an innovation context. It also describes the contracts that induce the licensee and the patentee to obtain the maximum pro t when using this licensing contract. We analyze the IC region for cost-reducing innovations " and royalty ratios in two situations: the non-drastic innovation and the drastic innovation. We also nd when licensing occurs, there is an e ciency loss. However, the IC region can limit the e ciency loss. Then, we extend our results to a two-stage game in order to check whether the royalty contract is still a good contract for both the licensee and the patentee from a pro t perspective. In stage two, when the size of innovation is smaller than the size of innovation in stage one, royalty contracts are inferior to other contracts. However, when the size of innovation in stage two is greater than that in stage one, the royalty contract is an improvement over other contracts.
PH.D in Management Science, May 2014
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- Title
- ESSAYS ON DISTRIBUTIONALLY ROBUST PORTFOLIO OPTIMIZATION
- Creator
- Ousawat, Thitapon
- Date
- 2013, 2013-07
- Description
-
Interest in distributionally robust optimization has been increasing recently. In this dissertation, we review recent developments in the...
Show moreInterest in distributionally robust optimization has been increasing recently. In this dissertation, we review recent developments in the literature in this eld and propose a model for distributionally robust mean-risk portfolio optimization. The model optimizes a risk-averse objective function with the worst-case return as reward and worse-case conditional Value-at-Risk as the risk measure. The model considers ambiguity in the distribution of data used to estimate the asset returns in the optimization model by creating an ambiguity set using -divergence measures which measure the distance between vectors. A numerical example is shown using the Kullback-Leibler divergence measure as the -divergence measure. A model for distributionally robust portfolio optimization with transaction costs is used to compare the performance of a distributionally robust mean-CVaR portfolio with the nominal as well as equally-weighted portfolio. The result shows that, under certain conditions, the distributionally robust model performs better than both the nominal and equally-weighted portfolio.
PH.D in Management Science, July 2013
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- Title
- EFFECTS OF DIFFERENT WRITTEN DISCLOSURE INTERVENTIONS AND THE MECHANISMS OF ACTION RESPONSIBLE FOR REDUCING MALADAPTIVE RUMINATION AMONG BROODERS
- Creator
- Coyle, Cynthia Weinstein
- Date
- 2013, 2013-07
- Description
-
Brooding is a maladaptive form of rumination associated with negative bias, emotion dysregulation, ineffective problem solving, and depression...
Show moreBrooding is a maladaptive form of rumination associated with negative bias, emotion dysregulation, ineffective problem solving, and depression (Nolen-Hoeksema, 1991; Treynor, Gonzalez, & Nolen-Hoeksema, 2003). Some data indicate that writing interventions reduce brooding (Gortner, Rude & Pennebaker, 2006). What is less known are the mechanisms whereby writing counteracts brooding. The primary aim of this study was: (1) to examine the effects of writing conditions on functioning in brooders and (2) to provide empirical support for the mechanisms of action for how writing reduces brooding. Those who wrote from specific instructions were hypothesized to increase their cognitive appraisal, emotion regulation, and problem-solving abilities, thereby reducing brooding more than those writing from expressive writing and control group instructions. Writing also was hypothesized to reduce brooding through these mechanisms. Gaining a greater understanding of which writing techniques were most effective in reducing brooding and of how brooding is reduced is important for rumination research and therapeutic practice. Eighty-eight adults recruited from a mid-western university and the general population were divided into two experimental conditions (Expressive Writing (EW) and Self-Regulation/Problem-Solving (SR/PS) and one control group. A 3 X 2 MANOVA was conducted to determine whether improvements after the writing intervention were (a) greater in the EW and SR/PS conditions than in the control condition and (b) greater in the SR/PS condition than in the EW condition. A 3 X 2 MANOVA also was conducted to determine whether there were reductions in negative cognitive word use over time. Participants completed a survey of their subjective experience at the end of the study. ix Contrary to predictions, none of the hypotheses were supported. Improvements were not greater in either experimental group compared to the control group or in the SR/PS condition compared to the EW on any of the outcome variables. Only the use of anger words was significantly reduced over time. Given there were no significant reductions in brooding and no relationship between the predictor and outcome variables, a mediation analyses was not conducted. In contrast, subjective reports indicated that participants in the experimental conditions perceived the study to have greater meaning and felt happier after the study compared to the control group. Participants also reported improved emotion regulation, cognitive processing and problem-solving abilities. The findings suggest considering of an individual’s perception of treatment benefits when determining effectiveness.
PH.D in Psychology, July 2013
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- Title
- MULTI-DISCIPLINARY PERFORMANCE-BASED FORM GENERATION PROCESS: DEVELOPING AN OPTIMIZATION APPROACH FOR LONG SPAN ROOFS
- Creator
- Nicknam, Mahsa
- Date
- 2013, 2013-05
- Description
-
This research is intended to incorporate multiple performances into the architectural form generation process of long span roofs. To this end,...
Show moreThis research is intended to incorporate multiple performances into the architectural form generation process of long span roofs. To this end, it proposes a multidisciplinary performance-based form generation process (MPGP) using Genetic Algorithm (GA) for the exploration of form based on performance criteria. This process leads us to a new integrated design approach in architecture. Conceptual design decisions have the greatest impact on building performance. However in conventional linear approaches, energy and structural issues are typically dealt with after these program, massing, and enclosure decisions are well articulated. This locks in life-cycle performance, and leads to costly redesigns when results fail to satisfy requirements. Research has shown how successful buildings emerge from the rapid and systematic generation and multidisciplinary analysis of many alternatives. However, until recently Architecture, Engineering and Construction (AEC) design teams were constrained by tools and schedule and only be able to generate a few alternatives, and analyze these from just a few perspectives. The rapid emergence of parametric and generative design, building simulation, and design space exploration and optimization tools now make it possible for a design team to construct and analyze far larger design spaces more quickly, and better understand the importance of design variables on the overall building performance. The proposed process, moves beyond the current form generation approaches by using the dynamic potential possibilities of simulation tools in which form generation is based on their performance feedback. The simultaneous integration of multiple xvi performances at the early stage of design minimizes the need to move back and forth later on the design development phase, therefore reducing the overall design circle. MPGP uses the potential of parametric algorithm to generate the form and uses an optimization algorithm, Genetic Algorithms (GAs), as a search algorithm to explore the proper design satisfying required performances. This method will demonstrate how a flexible 3D model can be parametrically altered toward targeted solutions with the help of near real-time feedback generated by performance-based analysis tools within an optimization framework. Hence, in this approach, design is considered to be a process of a repeated loop of generation, evaluation, and modification until the targeted objectives are satisfied. The integration of generative tools and performance analytical tools in the early stage of design provides great opportunities for the designers to enhance the design space and select the proper design among different design solutions based on their preferences. As a result, designers develop architectural forms based on informed decisions by observing the impact of the varying parameters on the structural and energy efficiency performances. Consequently, this process will greatly benefit engineering by achieving a more collaborative and information-based design environment. Increasing the number of efficient design alternatives, dealing with different levels of complexity in the architectural design process, promoting multi-disciplinary collaboration, and improving overall design understanding are the main benefits of the proposed process.
PH.D in Architecture, May 2013
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- Title
- XAFS STUDIES OF RADIATION DAMAGE IN NUCLEAR MATERIALS
- Creator
- Olive, Daniel Thomas
- Date
- 2012-11-13, 2012-12
- Description
-
The growing demand for nuclear energy places a high importance on the development of new materials capable of withstanding higher temperatures...
Show moreThe growing demand for nuclear energy places a high importance on the development of new materials capable of withstanding higher temperatures and harsher irradiation conditions than those used in existing reactors. By supporting the development of next generation reactors it also becomes possible to close the nuclear fuel cycle, greatly reducing the amount of waste sent for disposal in deep geologic repositories, where its interaction with the environment is also a matter of interest. In this thesis, X-ray absorption fine structure (XAFS) spectroscopy is used to investigate the local atomic structure of systems of interest to nuclear energy. First, two XAFS studies on environmental materials are presented. Granular activated carbon (GAC) was treated with iron to improve its water remediation properties, specifically with respect to arsenic. XAFS was used to determine the nature of iron coating on the GAC surface, and the method of arsenic bonding to the treated surface. Next, a neodymium precipitate from solubility studies carried out for the Waste Isolation Pilot Plant (WIPP) was analyzed. Neodymium was used as an analog for plutonium in brine solutions. XAFS fitting indicated that the neodymium substituted for calcium in a gypsum lattice, providing information useful for future geochemical modeling. XAFS was also used to study radiation damage in materials. A candidate material for advanced reactor structural materials, modified 9Cr–1Mo, was irradiated to 1, 4, and 10 displacements per atom (dpa). XAFS analyses were performed on the Fe, Mo, and Nb K-edges. Irradiation caused a reduction in coordination for all three elements, but the exact behavior was element specific. Damage around Fe atoms was linear with dose, while damage around xxii Mo atoms saturated at or before 1 dpa. XAFS was shown to provide a useful atomic level description of radiation damage for a complex alloy system. Finally, zirconium carbide and zirconium nitride, candidate materials for advanced fuel claddings were studied at the Zr K-edge. Samples irradiated to 1 dpa retained overall crystallinity, as indicated by transmission electron microscopy (TEM) images but were found to have an increase in dislocation loops compared to their non-irradiated counterparts. XAFS analysis was able to determine the size of the undefected regions, making it a valuable complement to other analysis techniques. xxiii
PH.D in Physics, December 2012
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- Title
- PRE-CLINICAL IN VIVO AND IN VITRO ASSESSMENT OF HEMOSTATIC EFFECTS OF CONTINUOUS-FLOW VENTRICULAR ASSIST DEVICES
- Creator
- Crandall, Daniel
- Date
- 2011-07, 2011-07
- Description
-
Heart failure results in significant morbidity and mortality for those afflicted. The current gold standard treatment is allogenic heart...
Show moreHeart failure results in significant morbidity and mortality for those afflicted. The current gold standard treatment is allogenic heart transplantation, however insufficient supply of donor organs limits the effectiveness of this treatment to ideal candidates. This has led to interest in mechanical circulatory support. The most recent generation of devices are smaller, continuous-flow devices with increased durability compared to their predecessors. However, these new devices exhibit increased rates of hemostatic events – both thromboembolic and hemorrhagic. This thesis details an in vivo evaluation of hemostatic parameters in a bovine animal model to evaluate the effect of the ventricular assist device (VAD), and compares these results to what has been seen clinically. Most importantly this thesis has found that bovines do not experience pathophysiologic degradation of high molecular weight Von Willebrand Factor (VWF) as a result of VAD placement, whereas this complication is well documented in humans. This is due to a decreased sensitivity to shear stress induced cleavage of VWF in bovines when compared to humans, as demonstrated in this thesis. Due to the inability to replicate clinical conditions with the bovine animal model, this thesis develops an alternative methodology using an in vitro flow loop using the same human donor blood on all pumps tested. This methodology eliminates the need for interspecies extrapolation; allows for more direct comparisons by eliminating donor variation; and is both cheaper and faster than animal models. This methodology could provide an invaluable option for evaluating hemostatic effects of various pump design parameters.
Ph.D. in Biomedical Engineering, July 2011
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- Title
- THE IMPACT OF THE JOINT POSTURE ON FINGER NEUROMECHANICS
- Creator
- Qiu, Dan
- Date
- 2014, 2014-05
- Description
-
This dissertation presents a series of studies investigating the neuromechanical properties of the index finger with special emphasis on how...
Show moreThis dissertation presents a series of studies investigating the neuromechanical properties of the index finger with special emphasis on how these properties varied with finger posture. A cadaver study was performed to measure the mapping relationship between tendon force and the resulting fingertip force. A strong linear relationship between magnitude of the tendon force and magnitude of the produced fingertip force was confirmed, up to the force levels examined. The finger posture, however, strongly influenced both fingertip force direction and magnitude. Two fundamental hypotheses of finger biomechanical modeling were then tested in further cadaveric studies. The preliminary results supported the assumption of linear superposition of the contributions of individual tendon forces to the overall fingertip force, at least for two muscles up to the force levels tested. It is also confirmed that the index finger force was almost exclusively produced by the muscles of the index finger, with relatively minor contributions from the other compartments of flexor digitorum superficialis (FDS), flexor digitorum profundus (FDP), or extensor digitorum communis (EDC). An in-vivo human subject study was performed to examine muscle activation patterns during isometric fingertip force production across task directions and finger postures. It was shown that significant changes in muscle excitation patterns occurred, especially with variations in interphalangeal (IP) posture. These changes involved fundamental variation in the underlying pattern rather than just scaling of a given activation pattern. An anatomically correct force-based computer model of the index finger was built to study the roles of different structures and characteristics in finger task performance. The model was validated with the cadaver study result to display its reliability in predicting fingertip xiii force and dynamic movement for given tendon forces. The model was then employed to estimate some hard-to-measure variables including joint contact force and joint passive torque components. The simulation of tendon injuries with the model, including Boutonniere deformation and mallet finger, was able to predict the abnormal finger joint movements under these patho-mechanical conditions. The model simulation also suggested that fingertip force capacity was largely maintained after selected tendon pulley excision surgeries.
PH.D in Biomedical Engineering, May 2014
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- Title
- MOLECULAR MECHANISMS OF ESTROGEN RECEPTOR BETA ACTION IN COLORECTAL CARCINOGENESIS
- Creator
- Vaz Saleiro, Diana Nora
- Date
- 2013, 2013-07
- Description
-
Colorectal cancer (CRC) is a major public health problem in the world population, which emphasizes the need to study novel molecular targets...
Show moreColorectal cancer (CRC) is a major public health problem in the world population, which emphasizes the need to study novel molecular targets in order to develop alternative chemopreventive and chemotherapeutic strategies against it. Estrogens have been shown to exert a protective role against CRC and its actions seem to be mediated by estrogen receptor β (ERβ). However, further studies are required to elucidate the role of ERβ in the colon. To achieve this goal, we evaluated the effects of ERβ deficiency in sporadic CRC and colitis-associated CRC (CAC) by using two in vivo models. In addition, we stably transfected RKO colon cancer cells to overexpress ERβ and identify novel molecules regulated by ERβ signaling in vitro. In the sporadic CRC in vivo model, azoxymethane (AOM)-treated ERβ knockout (βERKO) mice showed a significantly higher incidence and multiplicity of colonic preneoplastic lesions compared to AOM-treated ERα knockout and wild-type (WT) mice. These results were associated with a loss of normal colonic crypt organization and a decrease in apoptosis rates suggesting that ERβ is the ER subtype with a protective role against sporadic CRC progression. Confirming this hypothesis, we observed that AOM-treated βERKO mice presented a significantly higher incidence of adenomas than WT mice. By real time-polymerase chain reaction and immunohistochemistry analyses, ERβ-deficient adenomas were shown to be more proliferative and less differentiated than adenomas in WT mice. Furthermore, in the CAC in vivo model, βERKO mice developed more severe clinical colitis compared to WT mice, as evidenced by significantly higher disease activity index, weight to length ratio of the colons, inflammation score, and grade of dysplasia. ERβ-deficient tumors were characterized by a significant increase in pro-inflammatory xv molecules, suggesting that ERβ might exert anti-inflammatory effects in CAC. Moreover, in vitro results revealed a novel molecular mechanism by which ERβ might drive differentiation of goblet cells in the colonic epithelium. Altogether these findings highlight the importance of ERβ in protection against colorectal carcinogenesis and provide a clinical and translational potential to use ERβ selective agonists in order to prevent and/or treat CRC.
PH.D in Biology, July 2013
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- Title
- RESPONSE STYLE AS A MODERATOR BETWEEN COMBAT EXPOSURE AND PTSD SYMPTOMATOLOGY
- Creator
- Walton, Jessica
- Date
- 2011-11, 2011-12
- Description
-
Throughout the literature, combat exposure has been consistently linked to PTSD symptomatology among combat veterans. However, the wayan...
Show moreThroughout the literature, combat exposure has been consistently linked to PTSD symptomatology among combat veterans. However, the wayan individual responds to clinical interactions, also known as their response style, has received little or no attention as a potential moderating variable between combat exposure and PTSD symptomatology. Much of the research in the area of response style has utilized the MMPVMMPI-2 validity scores as a means to detect over-reporting among combat veterans. However, at present, few studies have examined responses on both the MMPI-2 validity scales and the SIRS as they relate to the detection of over-reporting on other measures (i.e., PCL-M and CES). The current study seeks to examine whether the response style on selected MMPI2 F-family validity scales and the SIRS among a sample of Vietnam combat veterans moderates the relationship between combat exposure and PTSD symptom endorsement. Individuals' combat exposure and current PTSD symptomatology were assessed through the use of self-report measures. In addition, participant's response style was assessed through the use of both the MMPI-2 and the Structured Interview of Reported Symptoms (SIRS). The results of the study demonstrated that response style did not moderate the relationship between combat exposure and PTSD symptomatology. However, results did reveal that individual's responses on the SIRS were directly related to PTSD symptom endorsement.
Ph.D. in Psychology, December 2011
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- Title
- CONTROLLED RELEASE OF VANCOMYCIN FROM A THERMORESPONSIVE HYDROGEL SYSTEM FOR THE PROPHYLACTIC TREATMENT OF POST-OPERATIVE ACUTE ENDOPHTHALMITIS
- Creator
- Dosmar, Emily
- Date
- 2017, 2017-05
- Description
-
Current clinical treatment for preventing the post-operative endophthalmitis include a bolus injection of the antibiotic, vancoymin (VAN),...
Show moreCurrent clinical treatment for preventing the post-operative endophthalmitis include a bolus injection of the antibiotic, vancoymin (VAN), during surgery followed by a 1-2-week period of patient administered, topically applied antibiotics. Due to poor patient compliance, drug loss due to poor drug residence time for topically applied drops, and limitations of drug injection sites, there is a clinical need for a subconjunctival, sustained release drug delivery system. While a controlled drug delivery system is beneficial by eliminating patient drug administration and improving drug delivery, the challenges of initial burst (IB), drug release kinetics, and drug distribution must be addressed in order to design an optimal system to address this need. The primary goal of this study was to develop a drug delivery system (DDS) capable of delivering VAN for 10-14 days and replacing both the bolus VAN injection and the topical eye drops. We hypothesized that controlled and extended release of VAN will perform equally or better than bolus VAN administration and eye drops. To accomplish this goal, three specific aims were performed: 1) Development of an injectable drug delivery system to release bioactive VAN for at least 10 days; 2) Validation of the efficacy of the developed DDS; and 3) Development of a compartmental model analysis model used to predict the loading dose required to achieve therapeutic drug concentration in the vitreous.
Ph.D. in Biomedical Engineering, May 2017
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- Title
- NEW BEAMFORMING AND SPACE-TIME CODING SCHEMES FOR MIMO WIRELESS SYSTEMS
- Creator
- Tavassoli, Farhad
- Date
- 2013, 2013-05
- Description
-
Space-time coding and Beamforming are two main techniques utilized in multiple-input multiple-output (MIMO) wireless systems to increase...
Show moreSpace-time coding and Beamforming are two main techniques utilized in multiple-input multiple-output (MIMO) wireless systems to increase channel capacity. In this work, we present new beamforming algorithms and space-time codes for MIMO wireless systems to reduce the complexity and enhance the performance. We present a new framework to obtain beamforming algorithms for code division multiple access (CDMA) and orthogonal frequency division multiplexing (OFDM) systems based on principal component analysis (PCA) approach. Four different PCA objective functions are used as examples to illustrate how to obtain new beamforming algorithms based on the proposed framework. Since two of the objective functions result in the same algorithm, three different beamforming algorithms are obtained for CDMA and OFDM systems. We show that the new algorithms offer a desirable performance while they have considerably lower computational complexity than the optimum algorithms. It is demonstrated that the proposed algorithms also have a fast convergence rate. We also propose new space-time codes for both coherent and non-coherent wireless systems which can provide lower symbol error rates than existing codes in the same class. For the coherent case, we propose a new quasi-orthogonal code to provide a full-rate full-diversity transmission. Unlike the other codes in the literature, the proposed code does not require the transmitted symbols to be chosen from two different constellations. Choosing all symbols from only one constellation reduces the required storage memory to half of that needed in other methods. It also avoids decreasing the minimum distance between the symbols and hence, avoids degrading the coding gain. For the non-coherent case, a new constellation design for differential unitary space-time modulation is proposed. We generate xi a set of unitary matrices from the multiplication of a simple unitary matrix with entries of 1 by diagonal matrices made from quaternary alphabets. Then, the proposed constellation is formed from the product of the optimum matrix chosen from this set and the optimized diagonal matrix first used for the cyclic codes. We show that the proposed constellation yields a larger diversity product as well as a lower union bound for pairwise error probability with the same or lower complexity compared to other existing constellations.
PH.D in Electrical Engineering, May 2013
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- Title
- NEW DIRECTIONS IN POST-EARTHQUAKE FIRE HAZARD ANALYSIS WITH APPLICATIONS TO MIDWESTERN UNITED STATES
- Creator
- Farshadmanesh, Pegah
- Date
- 2017, 2017-05
- Description
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Post-earthquake fire ignition (PEFI) can lead to severe structural damage following an earthquake. Estimating the risk of such ignitions in...
Show morePost-earthquake fire ignition (PEFI) can lead to severe structural damage following an earthquake. Estimating the risk of such ignitions in buildings and identifying methods to abate it are essential steps in an overall effort to mitigate the impact of post-earthquake fires in urban areas. While several models have been developed for areas with available historical PEFI data, such as the Western United States, no such models have been developed for areas with little or no data specific for post-earthquake fires. Examples of such areas are seismic regions in the Midwestern United States. The lack of PEFI data for these areas is due to the fact that at the time of several significant earthquakes in the early nineteenth century, most earthquake-stricken communities where rural. With the growth of urban areas in the region, a need exists for a methodology that can be effectively used in estimating PEFI risks when no or little historical data is available. In this research, it was found that models for PEFI risk estimation may indeed be developed using available data on ignitions for normal conditions as a basis and then using some type of a modification factor to account for the significance of future earthquakes. This modification factor depends on the characteristics of the region in terms of seismic activities and the type and distribution of buildings and their potential in promoting ignitions. The term “normal condition ignition” (NCI) refers to an ignition that occurs due to everyday activities and routine operations in a building. In a residential building, such activities include, for example, operating heating units and burners, cooking, and mechanical malfunction of appliances. In this research, it was found that four factors specifically affect PEFI risk and can be used to develop models for risk estimation. These are (1) spatial characteristics such as geographic concentration of particular building types; (2) ignitability characteristics, such as the sources of ignitions in a particular building type, (3) earthquake characteristics (such as the peak ground acceleration); and (4) temporal characteristics, such as the time of the earthquake and seasonality. Accordingly, models for estimating the risk of post-earthquake fire ignition occurrence are developed. These models are tested, and the model parameters calibrated, using information in areas for which both the NCI and PEFI data are available (such as in the Western United States). To illustrate the applicability of the models developed and proposed in this study, St. Louis City is considered. This constitutes a major urban area vulnerable to potential future seismic activities because of proximity to the New Madrid Fault Zone. Using the NCI data for this area, PEFI risk values are estimated based on probable future seismic activities in the region. The results are presented in terms of estimated annual risk of post-earthquake fires for the area specifically for residential buildings (such as single or multifamily dwellings). The study further discusses the significance of PEFI models, their limitations and also provides suggestions for the future continuation of the research.
Ph.D. in Civil Engineering, May 2017
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- Title
- MODERATED MEDIATION OF LEADER'S TRAITS AND EFFECTIVENESS: THE ROLE OF STRESS
- Creator
- Fearing, Benjamin K.
- Date
- 2015, 2015-12
- Description
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The current study examined the relationship between individual differences and leadership effectiveness for 196 leaders informed by prominent...
Show moreThe current study examined the relationship between individual differences and leadership effectiveness for 196 leaders informed by prominent multi-trait models which included the distal traits of cognitive ability and the broad personality traits of extraversion, conscientiousness, neuroticism, and independence and the proximal traits of leadership self-efficacy (LSE) and motivation to lead (MTL). The study also quantified situational moderators in terms of a leader’s role ambiguity and situational constraints. The results supported a significant relationship between affective-identify MTL and leadership effectiveness with LSE as a proximal antecedent to MTL. Results also showed that (a) LSE had an indirect effect on leadership effectiveness through affectiveidentify MTL, (b) role ambiguity moderated the relationship between LSE and affectiveidentity MTL, and (c) the personality trait of independence had an indirect effect on leadership effectiveness through LSE and affective-identity MTL. However, hypotheses related to cognitive resource theory were not supported such that there was not a significant moderating effect of job stress on the relationship between cognitive ability, managerial training, and leadership experience with leadership effectiveness.The current study examined the relationship between individual differences and leadership effectiveness for 196 leaders informed by prominent multi-trait models which included the distal traits of cognitive ability and the broad personality traits of extraversion, conscientiousness, neuroticism, and independence and the proximal traits of leadership self-efficacy (LSE) and motivation to lead (MTL). The study also quantified situational moderators in terms of a leader’s role ambiguity and situational constraints. The results supported a significant relationship between affective-identify MTL and leadership effectiveness with LSE as a proximal antecedent to MTL. Results also showed that (a) LSE had an indirect effect on leadership effectiveness through affectiveidentify MTL, (b) role ambiguity moderated the relationship between LSE and affectiveidentity MTL, and (c) the personality trait of independence had an indirect effect on leadership effectiveness through LSE and affective-identity MTL. However, hypotheses related to cognitive resource theory were not supported such that there was not a significant moderating effect of job stress on the relationship between cognitive ability, managerial training, and leadership experience with leadership effectiveness.
Ph.D. in Psychology, December 2015
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