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Title: MODE SPECTRA OF NATURAL DISTURBANCES IN A CIRCULAR JET AND THE EFFECT OF ACOUSTIC FORCING
Creator: Raman, G, Rice, Ej, Reshotko, E
Date: 1994-10
Publisher: SPRINGER VERLAG
Description: A modal spectrum technique was used to study coherent instability modes (both axisymmetric and azimuthal) triggered by naturally occurring...
Show moreA modal spectrum technique was used to study coherent instability modes (both axisymmetric and azimuthal) triggered by naturally occurring disturbances in a circular jet. This technique was applied to a high Reynolds number (400,000) jet for both untripped (transitional) and tripped (turbulent) nozzle exit boundary layers, with both cases having a core turbulence level of 0.15%. The region up to the end of the potential core was dominated by the axisymmetric mode, with the azimuthal modes dominating further downstream. The growth of the azimuthal modes was observed closer to the nozzle exit for the jet with a transitional boundary layer. Whether for locally parallel flow or slowly diverging flow, even at low levels of acoustic forcing, the inviscid linear theory is seen to be inadequate for predicting the amplitude of the forced mode. In contrast, the energy integral approach reasonably predicts the evolution of the forced mode.
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Title: THE MOLECULAR MECHANISM OF BAXΔ2-MEDIATED CELL DEATH AND ITS TISSUE DISTRIBUTION IN COLON CANCER
Creator: Zhang, Honghong
Date: 2014, 2014-07
Description: Bax is a pro-death tumor suppressor in the Bcl-2 family, and is frequently mutated in microsatellite instable tumors, especially Hereditary...
Show moreBax is a pro-death tumor suppressor in the Bcl-2 family, and is frequently mutated in microsatellite instable tumors, especially Hereditary Non-Polyposis Colorectal Cancer (HNPCC). The loss of apoptotic Bax contributes to tumor development and chemoresistance. We recently uncovered that the combination of a Bax microsatellite mutation with a specific alternative splicing generated a unique Bax isoform (BaxΔ2) in Bax-negative cells. Similar to the prototype Baxα, BaxΔ2 is a potent pro-apoptotic molecule. However, the pro-apoptotic mechanism, therapeutic implication, and tumor tissue distribution of BaxΔ2 protein remain elusive. In this thesis research, we isolated and analyzed isogenic sub-cell lines that represent different Bax microsatellite statuses from colorectal cancer cells. We found that the colon cancer cells harboring Bax microsatellite G7/G7 alleles produced low levels of endogenous BaxΔ2 transcripts and proteins. BaxΔ2-positive cells were selectively sensitive to a subgroup of chemotherapeutics in comparison with BaxΔ2-negative cells. Different from other Bax isoforms, which mostly act through targeting mitochondria, BaxΔ2 recruited caspase-8 into the aggregates for activation, and consequently induced cell death independent of the mitochondrial pathway. Furthermore, the distribution of BaxΔ2 protein was mostly found in well-differentiated epithelial cells in primary colon tumor tissues or in primary squamous buccal cells, which contain Bax G7 mutation. However, not all cells harboring the Bax G7 mutation had a detectable level of BaxΔ2 proteins. These data suggest that, similar to Baxα, BaxΔ2 protein is pro-apoptotic, but not toxic to normal cells; expression of BaxΔ2 protein restores apoptotic program in Bax negative cells via a non-classical signaling pathway. Importantly, BaxΔ2 may provide a selective chemotherapeutic advantage for certain Bax-negative colon tumors.
Ph.D. in Biology, July 2014
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Title: Center for Chemical Dependency Recovery: Center for Chemical Dependency Recovery
Creator: Rymarz, Anna
Date: 4/29/2011, 2011-05
Description: The recovery center is a place of spiritual and physical healing for patients suffering from substance abuse. Through medical treatment,...
Show moreThe recovery center is a place of spiritual and physical healing for patients suffering from substance abuse. Through medical treatment, education and encouragement, the center will strive to mitigate the discomforts associated with detoxification and rehabilitation.Nature has been proven to: help hospital patients heal faster, reduce stress and improve mood. Therefore, the building’s wonderful views, vast amounts of daylight, healing gardens, use of natural materials, and easy access to a large park, were all design schemes to create the most therapeutic environment.
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$Central exclusive production and the Durham diffractive program$

Title: Central exclusive production and the Durham diffractive program, Proceedings of the XLIII International Symposium on Multiparticle Dynamics
Creator: Harland-lang, L. A., Khoze, V. A., Ryskin, M. G.
Date: 2013-09-15, 2013-09-15
Publisher: IIT Press
Description: Recent results in central exclusive production within the Durham model are presented. A wide range of processes are considered, and their...
Show moreRecent results in central exclusive production within the Durham model are presented. A wide range of processes are considered, and their theoretical and phenomenological interest is discussed.
Sponsorship: IIT College of Science, High Energy Physics Division of Argonne National Laboratory
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Title: DEVELOPMENT OF COMPUTER-AIDED DIAGNOSIS METHODS IN MAMMOGRAPHY
Creator: Wang, Juan
Date: 2015, 2015-12
Description: Computer-aided diagnosis (CAD) is developed as a diagnostic aid to provide a “second opinion” in diagnosis of breast cancer in early stage....
Show moreComputer-aided diagnosis (CAD) is developed as a diagnostic aid to provide a “second opinion” in diagnosis of breast cancer in early stage. Clustered microcalcifications (MCs) can be an important early sign of breast cancer. The goal of this work is to develop automatic CAD methods in mammography for breast cancer. Its contribution consists of both development of machine learning algorithms and study of related issues in detection and diagnosis of breast cancer with clustered MCs. First, a bi-thresholding scheme is proposed for reduction of false-positives (FPs) associated with linear structures in MC detection. An unified classifier with dummy variable modeling is further developed to reduce the FPs caused by both linear structures and MC-like noise patterns. It is demonstrated that both of the proposed algorithms can reduce FPs in MC detection, and thus, improve the detection accuracy significantly. Second, a spatial density modeling approach is investigated to quantify the spatial distribution of the MCs in a cluster when the MC detection is inaccurate. A spatial density function (SDF) is defined such that the extracted features are more robust to the presence of FPs and false-negatives (FNs) in MC detection. The results show that the features extracted from the SDF can achieve better class separation while being robust to the variations in MC detection when compared with those extracted from a traditional region-based method. Third, a retrieval-boosted approach is studied to discriminate between the benign and malignant MC lesions. A retrieval strategy is proposed to boost the classification performance by taking into account the similarity both in image features and in pathology. An adaptive Adaboost classifier, which can be adapted to the retrieved cases at a low computational cost, is applied to demonstrate the benefit of the retrieval strategy. The results show that the retrieval-boosted approach can signifishow that the features extracted from the SDF can achieve better class separation while being robust to the variations in MC detection when compared with those extracted from a traditional region-based method. Third, a retrieval-boosted approach is studied to discriminate between the benign and malignant MC lesions. A retrieval strategy is proposed to boost the classification performance by taking into account the similarity both in image features and in pathology. An adaptive Adaboost classifier, which can be adapted to the retrieved cases at a low computational cost, is applied to demonstrate the benefit of the retrieval strategy. The results show that the retrieval-boosted approach can significantly outperform its baseline classifier and that inclusion of pathology information in the retrieval can further improve the classification accuracy. Fourth, the perceptual similarity of MC lesions by radiologists is studied. The issues investigated include the degree of variability in the similarity ratings, the impact of this variability on agreement between readers in retrieval of similar lesions, and the factors contributing to the readers’ similarity ratings. The results indicate that perceptually similar lesions could be of diagnostic value in diagnosis for clustered MCs. Fifth, the feasibility of modeling the perceptual similarity of MC lesions is investigated. A support vector regression (SVR) is applied to model the perceptual similarity of clustered MCs, and a feature saliency analysis derived from SVR is used to determine the most relevant image features among a large set of candidate features. The results demonstrate that the relevant features are consistent in radiologists’ similarity ratings among different MC lesions, indicating that the perceptual similarity of MC lesions by radiologists can be effectively modeled. Finally, whether retrieval of similar images can effectively assist radiologists in diagnosis of clustered MCs is investigated. A retrieval system for relevant images is designed by considering both perceptually similar image features and the likelihood of malignancy of the lesion under consideration. An observer study is conducted to evaluate the diagnostic value of the proposed retrieval system. The results indicate that the proposed retrieval system has the potential to improve the reader’s ability in diagnosis of breast cancer with clustered MCs.
Ph.D. in Electrical Engineering, December 2015
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Title: Quantitative Tools for Stochastic Dynamical Systems: Invariant Structures and Escape Probabilities
Creator: Kan, Xingye
Date: 2012-07-16, 2012-07
Description: Three types of quantitative structures, stochastic inertial manifolds, random invariant foliations, and escape probabilities, are investigated...
Show moreThree types of quantitative structures, stochastic inertial manifolds, random invariant foliations, and escape probabilities, are investigated to study stochastic dynamical systems. Invariant structures for stochastic dynamical systems are reviewed and detailed techniques for their simulation, approximation and construction are presented with several illustrative examples. First, a numerical approach for the simulation of inertial manifolds of stochastic evolutionary equations with multiplicative noise is presented and illustrated. After splitting the stochastic evolutionary equations into a backward and a forward part, a numerical scheme is devised for solving this backward-forward stochastic system, and an ensemble of graphs representing the inertial manifold is consequently obtained. This numerical approach is tested in two illustrative examples: one is for a stochastic differential equation and the other is for a stochastic partial differential equation. Second, invariant foliations for dynamical systems with small white noisy perturbation are approximated via asymptotic analysis. In other words, random invariant foliations are represented as a perturbation of the corresponding deterministic invariant foliations, with deviation errors estimated. The escape probability is a deterministic concept making methods of partial differential equations theory attainable to stochastic dynamics. Finally, the escape probability p(x) for dynamical systems driven by non-Gaussian L´evy motions, especially symmetric α-stable L´evy motions, is considered and characterized. More precisely, it is represented as the solution of the Balayage-Dirichlet problem of a certain partial differential-integral equation. This issue has been investigated previously for dynamical systems driven by Wiener process. Differences between escape probabilities for dynamical systems driven by Gaussian and non-Gaussian noises are highlighted.
Ph.D. in Applied Mathematics, July 2012
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Title: EVALUATION OF FLIP-FLOP JET NOZZLES FOR USE AS PRACTICAL EXCITATION DEVICES
Creator: Raman, G, Rice, Ej, Cornelius, Dm
Date: 1994-09
Publisher: ASME-AMER SOC MECHANICAL ENG
Description: This paper describes the flowfield characteristics of the flip-flop jet nozzle and the potential for using this nozzle as a practical...
Show moreThis paper describes the flowfield characteristics of the flip-flop jet nozzle and the potential for using this nozzle as a practical excitation device. It appears from the existing body of published information that there is a lack of data on the parameters affecting the operation of such nozzles and on the mechanism of operation of these nozzles. An attempt is made in the present work to study the important parameters affecting the operation and performance of a flip-flop jet nozzle. Measurements were carried out to systematically assess the effect of varying the nozzle pressure ratio (NPR) as well as the length and volume of the feedback tube on the frequency of oscillation of this device. Flow visualization was used to obtain a better understanding of the jet flowfield and of the processes occurring within the feedback tube. The frequency of oscillation of the flip-flop jet depended significantly on the feedback tube length and volume as well as on the nozzle pressure ratio. In contrast, the coherent velocity perturbation levels did not depend on the above-mentioned parameters. The data presented in this paper would be useful for modeling such flip-flop excitation devices that are potentially useful for controlling practical shear flows.
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Title: POWER PROFILING, ANALYSIS, LEARNING, AND MANAGEMENT FOR HIGH-PERFORMANCE COMPUTING
Creator: Wallace, Sean
Date: 2017, 2017-05
Description: As the field of supercomputing continues its relentless push towards greater speeds and higher levels of parallelism the power consumption of...
Show moreAs the field of supercomputing continues its relentless push towards greater speeds and higher levels of parallelism the power consumption of these large scale systems is steadily transitioning from a burden to a serious problem. While the machines are highly scaleable, the buildings, power supplies, etc. are not. Even the most power efficient systems today consume one to two megawatts per peata op/s. Multiplying that by 1,000 to reach the next generation of supercomputer (i.e., exascale) and the power necessary just to turn the machine on is simply impractical. Thus, power has become a primary design constraint for future supercomputing system designs. As such, it has become a matter of paramount importance to understand exactly how current generation systems utilize power and what implications this has on future systems. As the saying goes, you can't manage what you don't measure. This work addresses several large hurdles in fully understanding the power consumption of current systems and making actionable decisions based on this understanding. First, by leveraging environmental data collected from runs of real leadership class applications we analyze power consumption and temperature as it pertains to scale on a production IBM Blue Gene/Q supercomputer. Then, through development of a new power monitoring library, MonEQ, we quantitatively studied how power is consumed in major portions of the system (e.g., CPU, memory, etc.) through profiling of microbenchmarks. Expanding on this, we then studied how scale and network topology affect power consumption for several well-known benchmarks. Wanting to increase the effectiveness of our power monitoring library, we extended it to work with many of the most common classes of hardware available in today's HPC landscape. In doing so, we provided an in-depth analysis of what data is obtainable, what the process of obtaining it is like, and how data from different systems compares. Next, utilizing the knowledge gained from these experiences, we developed a new scheduling approach which utilizing power data can effectively keep a production system's power consumption under a user-specified power cap without modification to the applications running on the system. Finally, we extend this scheduling approach to be applicable to more than just one objective. In doing so, the scheduler can now optimize on multiple criteria instead of simply considering system utilization.
Ph.D. in Computer Science, May 2017
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Title: SEISMIC DESIGN STUDY OF STEEL PLATE SHEAR WALL
Creator: Moshiri, Ali
Date: 2012-04-20, 2012-05
Description: plate shear walls are an innovative lateral load-resisting system capable of effectively and economically bracing a building against both wind...
Show moreplate shear walls are an innovative lateral load-resisting system capable of effectively and economically bracing a building against both wind and earthquake forces. The system consists of infill steel plates connected to boundary beams and columns over the full height of the framed bay. Beam-to-column connections can be rigid or shear connections and the infill plates can be either stiffened or unstiffened, depending on the design philosophy of the infill plates. The view of some structural designers is to use heavy stiffeners to reinforce and increase the buckling capacity of shear walls, whereas, if the walls are left unstiffened and allowed to buckle, their energy absorption will increase significantly due to the post-buckling capacity. Performance of 9-story SPSW with moment resisting beam to column connections was studied under quasi-static loading condition and 10 earthquake records recorded in Los Angeles by developing a nonlinear dynamic explicit finite element models in ABAQUS. All the models were validated with experimental results. Effect of stiffness of boundary elements (VBE and HBE) and plate thickness on general behavior of the structure were also investigated. In design of SPSWs, vertical boundary elements play a major role in increasing the capacity of the system. In high seismic zones there is always a chance of plastic hinge formation in the boundary elements specially columns in any intermediate floor. It is recommended that SPSWs not be used for medium to high rise buildings in high seismic regions until the lack of capacity design requirements for this type of SPSW is rectified.
Ph.D. in Structural Engineering, May 2012
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Title: Widget Applications to Enhance the Tru2Way Consumer Experience (sequence unknown), IPRO 312 - Deliverables: IPRO 312 Final Report F09
Creator: Alsharief, Yagoob, Aulfata, Muluken, Curtis, Christopher, Dhewaju, Anusuya, Mooney, Kevin, Mutyaba, Kevin, Ndoping, Marco, Onaissi, Samah, Peterson, Naomi, Siwek, Steven, Wallace, Sean, Yi, Won-jae
Date: 2009-12
Description: The IPRO teams objectives are to provide Comcast with feedback from an outside perspective, allowing them to see where their Tru2Way system...
Show moreThe IPRO teams objectives are to provide Comcast with feedback from an outside perspective, allowing them to see where their Tru2Way system needs additional attention or support.
Sponsorship: Comcast
Deliverables for IPRO 312: Widget Applications to Enhance the Tru2Way Consumer Experience for the fall 2009 semester
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Title: Protecting the Artists' Social Construct in a Mutually Beneficial Developer Environment: DSheen_ProtectingArtistsSocialConstruct_Presentation
Creator: Sheen, Daniel
Date: 2011, 2011-05
Description: This project is a mixed-use high rise which will incorporate the program of the newly constructed high rise buildings of retail, hotel, and...
Show moreThis project is a mixed-use high rise which will incorporate the program of the newly constructed high rise buildings of retail, hotel, and condominiums with the program of the existing Powerhouse Arts District, art gallery, auction house, art work spaces, and artist lofts. In order for this combination of program to occur and to retain developer interest in this high rise tower, relationships between the program were investigated. Typical “inefficient” or unleasable spaces in a traditional high rise were used as opportunities to incorporate these art district programs into the site. Artist lofts were design on the perimeter of the mechanical floors to take advantage of double height spaces as well as privacy. Art galleries, and an auction house was incorporated on the lower service level in order to take advantage of loading/unloading access. Art work spaces were designed around program which required column free spacing and a sunken art plaza was designed to add additional frontage to different retail and art programs located below grade. The design of both the high rise and its program intends to restore the deteriorating identity of the Powerhouse Arts District in Jersey City, NJ.
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Title: Laboratory Notebook 10
Creator: Sadler, George
Date: 2010-03-04T19:33:56Z
Description: This laboratory notebook is entitled "Acrylamide vs. Hunter "L" Value.

Title: New Urban Living in a Closed City
Creator: Witzman, Brad
Date: 2010-05-01, 2010-05-01
Description: This project is investigating the change in urban dwelling typologies when an impassable perimeter is placed around a city for future social...
Show moreThis project is investigating the change in urban dwelling typologies when an impassable perimeter is placed around a city for future social and environmental reasons. I will work in two phases first establishing how the city might change and then designing a living unit which addresses the needs of those transplanted and fits into this new closed city.
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Title: POLARIZATION INDUCED BY A TERAHERTZ ELECTRIC FIELD ON A CONDUCTIVE PARTICLE
Creator: Shen, Tao
Date: 2013, 2013-05
Description: Interactions of an electromagnetic wave with an object of dimensions small compared to the wavelength can often be accounted for by...
Show moreInteractions of an electromagnetic wave with an object of dimensions small compared to the wavelength can often be accounted for by considering the dipole moments, which are effective in explaining the scattering characteristics in the frequency range referred to as the Rayleigh region. Dielectric functions derived from polarization processes due to molecular orientation or bound charge displacements have been employed over the years to account for the scattering properties of particles. In the presence of mobile charges, bulk conductivity may be incorporated with a complex dielectric function to explain the peak in absorption near the plasma frequency exhibited by metallic particles in the optical region. With the current interest in nanostructures, an investigation of the electromagnetic properties of a conductive particle with attention given to space-charge effects would appear timely. This can be accomplished by coupling the transport equations of the charge carriers to the Maxwell’s equations. Results of computations performed for elementary structures such as plates and particles revealed the screening of the internal field while dispersion and absorptions effects are shown by the complex dipole moments. To gain insight into the nature of charge-wave interactions, results based on quasi-static formulation for the electric field will be compared with those based on full-wave analysis, with special attention given to the charge and current distributions within the structure. By consideration of the physical process of charge carrier motion and lattice polarization, the equivalent circuit model for a conductive nanoparticle in the terahertz frequency range is developed. All circuit elements are of electrical nature and can be directly expressed in terms of material parameters. The equivalent circuit can serve as the basis of analysis for composite structures and aggregates of which the conductive nanoparticle is a constituent.
PH.D in Electrical Engineering, May 2013
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Title: COMPUTATIONAL MODELS OF TRANSPARENT WATER STORAGE ENVELOPES FOR ENERGY EFFICIENT COMMERCIAL BUILDINGS
Creator: Liu, Xiangfeng
Date: 2012-04-25, 2012-05
Description: Transparent Water Storage Envelopes (TWSEs) are climatic adaptive fenestration systems. The major part of the system is an array of modular...
Show moreTransparent Water Storage Envelopes (TWSEs) are climatic adaptive fenestration systems. The major part of the system is an array of modular transparent water containers which are integrated into frames of curtain walls, and serve as both façade and auxiliary water tanks for a commercial building. The concept originates from the idea of combing transparency with dynamic benefits of thermal mass in summer, as well as passive solar heating in winter. Optical and thermal characteristics of TWSEs, including their energy performance, have been studied systematically via numerical approaches. Two numerical procedures covered in the thesis: one is based on the simplified synchronized onedimensional nodal thermal model, and the other is based on the more complex and accurate synchronized CFD model. In each numerical procedure, a triple-step simulation methodology and the correlated computational models of TWSEs are employed. Based on the calculation and simulation results, it can be definitely concluded that TWSEs are energy efficient fenestration systems. They can outperform conventional glazing as long as being designed elaborately with the consideration of the unique physical characteristics, applied under suitable climatic conditions, and operated with appropriate energy efficiency measures. Furthermore, the innovative technical paradigm of TWSEs and the numerical approach developed for energy simulation of TWSEs demonstrate great potential to be implemented in engineering practice for energy efficient commercial buildings.
Ph.D. in Architecture, May 2012
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Title: VERIFICATION OF LARGE-SCALE ON-CHIP POWER GRIDS
Creator: Xiong, Xuanxing
Date: 2013, 2013-05
Description: As technology scaling continues, the performance and reliability of integrated circuits become increasingly susceptible to power supply noises...
Show moreAs technology scaling continues, the performance and reliability of integrated circuits become increasingly susceptible to power supply noises, such as IR drops and Ldi/dt noises in the on-chip power grids. Reduced supply voltage levels in the grid can increase the gate delay, leading to timing violations and logic failures. In order to ensure a reliable chip design, it is critical to verify that the power grid is robust, i.e., the power supply noises are acceptable for all possible runtime situations. Hence, power grid verification has become an indispensable step in modern design flow of integrated circuits. Nowadays, it is common practice to verify power grids by simulation. Typically, an equivalent RC/RLC circuit model of the grid is extracted from the layout, and designers perform simulations to evaluate the power supply noises based on the current waveforms drawn by the circuit. As power grid simulation can only be performed after the circuit design is done, vectorless power grid verification has been introduced to enable early power grid verification with incomplete current specifications, so that the power grid design can be better tuned and optimized at early design stages, thus reducing the design time. Due to the increasing complexity of modern chips, power grid verification has become very challenging. The broad goal of this dissertation is to explore efficient algorithms for verifying large-scale on-chip power grids. Specifically, we study parallel power grid transient simulation, vectorless steady-state verification and vectorless transient verification. Parallel forward and back substitution algorithms are designed for efficient transient simulation; a set of novel algorithms are developed to incrementally improve the runtime efficiency of vectorless steady-state verification; and an efficient approach is proposed for vectorless transient verification with novel constraint setting.
PH.D in Electrical Engineering, May 2013
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Title: DEVELOPMENT OF PHASED TWIN FLIP-FLOP JETS
Creator: Raman, G, Rice, Ej
Date: 1994-07
Publisher: ASME-AMER SOC MECHANICAL ENG
Description: The flip-flop nozzle is a device that can produce an oscillating jet flow without any moving parts. There is now a renewed interest in such...
Show moreThe flip-flop nozzle is a device that can produce an oscillating jet flow without any moving parts. There is now a renewed interest in such nozzles due to their potential for use as excitation devices in practical applications. An experiment aimed at developing twin flip-flop jets that operate at prescribed frequencies and phase differences was performed. The phasing was achieved using two different nozzle interconnection schemes. In one configuration the two jets flapped in-phase and in another they flapped out-of-phase with respect to each other. In either configuration the frequencies of oscillation of both jets were equal. When one of the jets was run at a constant high velocity and the velocity of the second jet was increased gradually, the higher velocity jet determined the frequency of oscillation of both jets. The two flip-flop jet configurations described in this paper could be used to excite a primary jet flow in either an anti-symmetric (sinuous) or a symmetric (varicose) mode.
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Title: Orthotics and Prosthetics in Latin America (sequence unknown), IPRO 309 - Deliverables: IPRO 309 Brochure F09
Creator: Ashley, Trevor, Claxton, Matt, Conover, Stephen, Gotanco, Francis, Mathai, Alexander, Nizich, Adam, Park, Yong, Quikr, Kerry, Ray, Monmayuri, Vasquez, Raul
Date: 2009-12
Description: The overall goal of our IPRO team is to create a program for delivering orthotics and prosthetics that is sustainable. This will be...
Show moreThe overall goal of our IPRO team is to create a program for delivering orthotics and prosthetics that is sustainable. This will be accomplished by improving the quality of the product by increasing availability of funding, improving cost effectiveness of prosthetics, and promoting awareness of treatment available.
Deliverables for IPRO 309: Orthotics and Prosthetics in Latin America for the fall 2009 semester.
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Title: An adaptive robust M-estimator for nonparametric nonlinear system identification
Creator: Wu, X. C., Cinar, A.
Date: 1996-08
Publisher: BUTTERWORTH-HEINEMANN LTD
Description: An adaptive robust M-estimator for nonparametric nonlinear system identification is proposed. This M-estimator is optimal over a broad class...
Show moreAn adaptive robust M-estimator for nonparametric nonlinear system identification is proposed. This M-estimator is optimal over a broad class of distributions in the sense of maximum likelihood estimation. The error distributions are described by the generalized exponential distribution family. It combines nonparametric regression techniques to form a powerful procedure for nonlinear system identification. The adaptive procedure's excellent performance characteristics are illustrated in a Monte Carlo study by comparing the results with previous methods.
Endnote format citation
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Title: EXPLORING THE SHEAR-AND-TIME DEPENDENT DEGRADATION OF VON WILLEBRAND FACTOR UNDER VENTRICULAR ASSIST DEVICE-RELATED FLOW CONDITIONS
Creator: Yang, Shuo
Date: 2015, 2015-12
Description: Abnormalities in VWF can cause impaired blood coagulation which results in higher bleeding tendency in patients with this disorder. Alteration...
Show moreAbnormalities in VWF can cause impaired blood coagulation which results in higher bleeding tendency in patients with this disorder. Alteration in VWF is characteristic in ventricular assist devices (VADs) implanted subjects with failing hearts. The nature of the abnormalities produced and the conditions which produce such abnormalities are not fully understood. The studies in this thesis investigate quantitatively the effects of VADs and VAD-related flow conditions on VWF degradation. This thesis consists of three studies: 1) an in vitro VAD loop study in which was investigated the degradation effects of three VADs either under preclinical development (VAD I) or being commercially available (VAD II & III); 2) a viscometer shear study in which was investigated a variety of factors under the controlled condition of a modified Couette viscometer, namely, shear stress, exposure time, pulsatile frequency and protease function, with respect to VWF degradation 3) a tubular shear study in which was investigated the relative degradation effects of shear stress versus exposure time under more VAD-related shear stresses (10 - 100 times higher than physiological levels) and exposure times of miliseconds. In the VAD flow loop, significant VWF degradation induced by VADs wee observed with an approximately 95% loss of high molecular weight VWF by 60 minutes. In the viscometer and the tubular studies, the factors studied enhanced VWF degradation in the following manner: increased shear stress above physiological levels, prolonged exposure time and higher pulsatile shear frequency were associated with greater degradation; shear stress was a more dominant factor than exposure time with respect to the degradation; and a various shear stress regions demonstrated maximal degradation effects. In addition, calcium-dependent protease function was a necessity for VWF degradation at all shear stress levels investigated. The studies also revealed that the unfolding of VWF to expose the cleavage sites appeared to take more time under shear than the refolding to re-cover those sites under static conditions. Critical shear regions may be important for unfolding and degrading VWF multimers of various sizes.
Ph.D. in Biomedical Engineering, December 2015
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