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Deployment and Validation of Low-Cost Wireless Sensors for Real-Time Lifeline Conditions Assessment
No full textThe Pacific Northwest is at risk for significant seismic and tsunami events, which are capable of severely damaging lifeline transportation infrastructure, particularly bridges. As the bridges in the United States age and begin to show signs of fatigue, the risk for severe damage increases. Proper monitoring and inspection of bridges is becoming increasingly important as bridges age, especially with the high likelihood of a significant seismic event. Structural health monitoring systems can be used to evaluate the condition of bridges throughout the area, and to quickly determine the state of lifeline bridges after a disaster. With technology advancing rapidly and making widespread monitoring possible, there exists a gap between the monitoring systems and the interpretation and presentation of recorded data. A framework needs to be developed to relay useful information to bridge owners and decision makers based on sensor readings. Numerical models of eight prototype bridges typical to the region were developed using the OpenSees FEA package. The numerical models were subject to a suite of ground motions to simulate the demands anticipated in the Pacific Northwest. The damage state of the bridges were compared to metrics that were measurable by using wireless bridge sensors. Recommendations were developed to permit wireless sensor data to be related to bridge performance.Pacific Northwest Transportation Consortium
Oregon State Universit
Reversibly Reconfigurable Plasmonic Nanomaterials
No full textThesis (Ph.D.)--University of Washington, 2017-12University of Washington Abstract Reversibly Reconfigurable Plasmonic Nanomaterials Soumyadyuti Samai Chair of the Supervisory Committee: Professor David S. Ginger Department of Chemistry Plasmonic nanoparticles have been extensively investigated in various fields, ranging from biosensing to nanophotonics, due to their characteristic optical features arising from localized surface plasmon resonance. A number of efforts have been made to tailor the optical properties of the nanoparticles by controlling their shape, size and chemical compositions that have advanced their applications in catalysis, molecular diagnostics, therapeutics, and designing electronic devices. Optical signatures of plasmonic nanoparticle assemblies depend on the near field coupling between the plasmon modes of the constituent particles that can be modulated by the distance and orientation between the particles. While the first-generation of plasmonic nanomaterials attempts to control the distance and directionality of the interparticle coupling by employing chemical reagents, recent developments to introduce stimulus-responsivity in the nanomaterials provide us opportunities to control the functional and optical properties of the such materials with external reagents such as light, heat, pH, electric field etc. These emerging plasmonic nanomaterials allow reversible reconfiguration of the structure that can be manipulated remotely, in a reagent-free manner, allowing reusability of the materials in all the applications. Such reconfigurable nanomaterials are obtained by combining the plasmonic nanoparticles with stimulus-sensitive materials. In this dissertation, I explore the use of photo-responsive DNA and thermo-responsive polymer poly(N-isopropylacrylamide) (PNIPAM) hydrogels, to construct reconfigurable assembly of plasmonic nanoparticles and characterize the reversible change in their optical properties in response to external stimuli. DNA has been a powerful material in nanotechnology for engineering 3D plasmonic structures, plasmon rulers and chiral nanophotonic elements. Not only the length and structural conformations of the DNA allow a precise tuning of interparticle distance and geometry of the nanostructures, but also it matches with the decay length of the near-field plasmon coupling. Recent advents of the azobenzene-phosphoramidite chemistry have facilitated the design of photo-responsive nanomaterials assembly, where the structural reconfiguration and the optical properties are controlled by the reversible trans-to-cis azobenzene photoisomerization. Such nanomaterials have found potential applications in low-cost, remote plasmonic biosensing, and optically active nanodevices. The functionality of such optically reconfigurable nanomaterials is extremely sensitive to efficiency of azobenzene photoisomerization in the DNA sequences. So, in chapter 3, we study the trans-to-cis photoisomerization of azobenzene-modified DNAs by measuring the photoisomerization quantum yields in different DNA sequences at various temperatures. Notably we provide the first report that the quantum yields of photoisomerization of azobenzene incorporated to a DNA phosphate backbone is temperature-sensitive and the temperature-dependent behavior is related to the host DNA sequence and its melting temperature. This result is unique in the sense that this behavior is distinct from the photoisomerization of free azobenzene in solution, which is independent of temperature. We also examined the effect of DNA sequences on the cis-to-trans reverse thermal isomerization of azobenzene. Our results indicate that the reverse thermal isomerization process is not affected by the DNA sequences and follows first order kinetics with an Arrhenius activation energy similar to that of the free azobenzene in solution. These findings provide effective design principles for engineering more efficient photo-reconfigurable plasmonic nanomaterials using azobenzene-modified DNAs. Next, in chapter 4 we demonstrate the assembly of photoswitchable gold nanoparticle dimers using an azobenzene-modified hairpin DNA linker and optically characterize their optical reconfiguration upon reversible photoisomerization of azobenzene. The trans-to-cis azobenzene photoconversion upon UV light exposure leads to the unzipping of the hairpin DNA that increases the separation between the two nanoparticles. Blue light illumination reforms the hairpin structure and restores the closed form of the dimer. The light-induced reconfiguration of the interparticle distances is reflected in the reversible plasmonic shift of the dimer scattering spectra measured by single particle dark field spectroscopy over multiple cycles of UV and blue light exposure. Our results significantly contribute to the fundamental understanding of the dynamical optical and structural properties of the DNA-linked gold nanoparticle dimers and lay the ground work for using them as building blocks in the future plasmonic nanomaterials. Finally, in chapter 5, we assemble and characterize novel reconfigurable hybrid nanocomposite materials that combines the optical properties of plate-like anisotropic silver nanoprisms with thermally responsive PNIPAM microgels. We find that these composites exhibit large thermochromic shifts upon the reversible volume-phase transition of PNIPAM that results in an easily observed color switching of the solution with temperature cycling. We also show that both the nanoprism size and loading density on the microgel can be used to independently tailor the thermo-responsive optical properties of the composites in the visible and NIR region of the spectra. The hybrid microgels exhibit a strong, reversible change and high contrast in NIR scattering intensity, achieved by the thermally reversible modulation of the interparticle distance and near-field plasmonic coupling upon swelling-deswelling of the PNIPAM microgels. These results create opportunities to use the novel plasmonic materials in designing thermochromic sensors, NIR labels for imaging and smart materials for nanophotonics applications
Effect of Time Measurement Error on Assessing Treatments with Time Dependent Effect
No full textThesis (Master's)--University of Washington, 2017-08In the emergency medicine setting, it is often difficult to accurately record the time of injury without measurement error. If the treatment effect varies depending on the time from injury to treatment initiation, this type of measurement error may affect our analysis of the treatment effect. A Phase III trial for Tranexamic acid (TXA) in trauma patients with significant hemorrhage, CRASH-2, suggested a significant association between the time from injury to treatment initiation and treatment effect in that the benefit of TXA treatment reduces as the time to treatment initiation gets longer. TXA is a drug used to prevent fibrinolysis and reduce surgical blood loss for patients with major trauma, with traumatic brain injury (TBI) or after surgery. In this work, I study the effect measurement error might have on a combined analysis of two ongoing clinical trials of TXA in TBI. One of these trials is a Phase II clinical trial conducted by the Resuscitation Outcomes Consortium (ROC) in the United States and Canada. It is a double blind, randomized placebo controlled clinical trial evaluating the efficacy of two dosing regimens of TXA in patients with TBI in a pre-hospital setting. The trial plans to enroll about 1,000 patients. The second trial, CRASH-3, is a Phase III double blind, randomized, placebo controlled multi-national trial of TXA in patients with TBI. This trial plans to enroll about 13,000 patients. For the purpose of this study, I define a time dependent effect as a treatment effect that varies as times from injury to treatment initiation vary. Any observed treatment effect may be smaller or larger than the true effect due to time measurement error and the time to treatment initiation may be underestimated or overestimated. For treatments with potential time dependent effect like TXA, I investigate in this study whether and how much their estimated treatment effect may be affected by measurement error using simulations. I use logistic regression to fit models of interest with and without measurement error, with and without interaction term and compare power, (for some model comparisons) bias and Type I error rates. I first investigated the effect of measurement error under the setting resembling the ROC TXA trial, and then under other more general settings. Finally, I also investigated the potential effect of measurement error for the dataset combining the simulated CRASH-3 data and simulated ROC TXA data using meta-analysis. The results were consistent with our expectation that the measurement error could reduce power for detecting treatment and interaction effect and increase estimation bias for treatment effect at time zero and interaction term and this impact of measurement error was only associated with the strength of absolute measurement error. However, if our assumptions are appropriate, an average 0.5 hour absolute measurement error in the ROC TXA trial does not meaningfully impact our analysis results and an average 1 hour absolute measurement error in the meta-analysis (combining simulated CRASH-3 and ROC TXA data) can still generate a power above 80% to detect both treatment and interaction effect
Landmark: Participatory Experiences in Commemorative Places
No full textThesis (Master's)--University of Washington, 2017-08This thesis focuses on visitor engagement at public monuments and memorials. Using the Statue of Liberty replica at Alki Beach in Seattle, Washington as the venue for the case study, this work explores how the visitor experience in commemorative spaces could become hands-on. The research findings provide insights for understanding what drives visitors to participate with interactive outdoor exhibits and activities
Computational Design of Hyperstable, De Novo Miniproteins Targeting PD-1
No full textThesis (Ph.D.)--University of Washington, 2017-12Computational protein design has recently advanced to a new era with the de novo design of stable proteins targeting native protein ligands. In this dissertation, I will present the first de novo protein binder with an all beta interface targeting the T cell receptor, programmed cell death protein 1 (PD-1). Expressed on activated T cells, PD-1 inhibits T cell function and proliferation to prevent an excessive immune response. Tumor cells often take advantage of this pathway by over-expressing one of the ligands of PD-1, PD-L1 or PD-L2, to evade immune destruction. Additionally, impairment of the PD-1 pathway through a variety of mechanisms can lead to autoimmunity. Using a combination of computational design and experimental approaches, we have developed a de novo miniprotein that specifically binds PD-1 at the ligand interface. This protein binds murine PD-1 at a Kd of approximately 1 µM on yeast. The apo crystal structure shows that the binder folds as designed with a backbone RMSD of 1.3 Å to the design model. The 4.5 kDa protein proved to be very stable by chemical denaturation in GuHCl likely due to its three disulfide bonds. Over the years, I have identified several other binders using the canonical method of yeast surface display that ultimately had to be abandoned because of their inability to be produced as soluble proteins. I hypothesize this results from the use of the highly expressed native yeast protein Aga2p for display of the protein-of-interest (POI) on the cell surface. Here, I present a new method that replaces the Aga2p fusion with a minimal tag for covalent capture of the secreted protein and takes advantage of the natural yeast quality control pathways to discriminate between misfolded and well-folded proteins. This novel secretion capture system is a powerful tool for the screening, optimization, and production of well-expressed, functional proteins. Improved high-throughput methods for screening and optimizing stable, functional proteins enable generation of de novo binders that are more readily amenable to a variety of applications. The small, hyperstable PD-1 binding domain presented here has potential use in a variety of cancer and autoimmune therapy platforms
Translating grand challenges from concept to community: The “Communities in Action” experience
No full text© 2017 by the Society for Social Work and Research
https://www.journals.uchicago.edu/doi/abs/10.1086/690561This article provides an example of how one social work school created a community partnership to translate grand challenges from concept to concrete local projects to meet Grand Challenges for Social Work goals. The Grand Challenge to Ensure Healthy Development for All Youth proposes that we have made sufficient scientific advances towithin a decadereduce the incidence and prevalence of behavioral health problems among children, adolescents, and young adults by 20%, and to reduce the incidence of racial and socioeconomic disparities in behavioral health problems by 20%. In 2014, faculty and students from the University of Washington School of Social Work began working with a broad coalition of community-based agencies, governmental partners, and funding agencies to tackle this grand challenge at the community level. The coalition adopted Communities That Care, a tested model for developing prevention infrastructure in communities by building the capacity of community coalitions to assess and prioritize local need, match need to evidence-based prevention programs, and support quality implementation with sufficient reach to change behavioral health problems at the community level. The collaboration chose the name Communities in Action for this effort. This article illustrates how Communities in Action exemplifies grand challenges implementation and highlights lessons learned that can be applied to other grand challenges efforts
Fragility functions for performance-based ground failure due to soil liquefaction
No full textPresented at the PBDIII conference in Vancouver, BC in July 2017.The severity of liquefaction manifested at the ground surface is a pragmatic proxy of damage potential for various infrastructure assets, making it particularly useful for hazard mapping, land-use planning, and preliminary site-assessment. Towards this end, the recent Canterbury, New Zealand, earthquakes, in conjunction with others, have resulted in liquefaction case-history data of unprecedented quantity and quality, presenting a unique opportunity to rigorously develop fragility-functions for liquefaction-induced ground failure. Accordingly, this study analyzes nearly 10,000 liquefaction case studies from 23 global earthquakes to develop fragility functions for use in performance-based frameworks. The proposed functions express the probability of exceeding specific severities of liquefaction surface manifestation as a function of three different liquefaction damage measures (LDMs), wherein four alternative liquefaction-triggering models are used. These functions have the same functional form, such that end-users can easily select the model coefficients for the particular damage state, triggering model, and LDM of their choosing. It should be noted that these functions are not to be used to predict lateral spreading, which requires LDMs other than those assessed herein. Lastly, the proposed functions are preliminary and subject to further development. In this regard, several thrusts of ongoing investigation are discussed
Evanescent Event : Using the Olympic City as a catalyst for change in post-industrial cities
No full textThesis (Master's)--University of Washington, 2017How can we become a progressive culture when we can not bear the thought of tearing our buildings down? Is our desire for permanence our greatest weakness? The architecture industry is slowly coming to terms with the future of buildings being designated ten or fifteen year buildings. What does this mean to the modern designer? At what point does a building lose its purpose? As we lose land area due to population growth, climate change, and other factors, the solution to a lack of land could be understanding how to properly demolish existing structures. If structures are built to be broken down, the process is more palatable and affordable, while offering its pieces as new material for use. This concept becomes preservation through memory, spatial cues, and academic rather than physical histories. Within these pages is a glance at a counterpoint to monumental buildings, and a proposal for the re-integration of sites and materials into the fabric from where they came. As a pinnacle of unused monuments, Olympic Stadiums and their associated villages are the structures of focus; have they not lost their purpose after three months of hosting Olympic and paralympic games? Olympic stadiums and their surrounding infrastructure systems seem to be just as expensive to maintain, and while their price tags are normally paid off by investors and developers, it is just as often that the burden falls onto local taxpayers, who could be facing the bill for up to thirty years, as was the case after the 1976 Olympics in Montreal. This thesis uses a site to study a proposal for a series of temporary homes; places it can inhabit without leveling local communities, exploiting taxpayers, or be a burden on local industries. As is the nature of temporary installments which are meant to be re-absorbed, the methods used for implementing a large-scale, responsive, miniature city are different depending on location. With Detroit as an initial study, event programs such as the Olympics are meant to be used as catalysts, inspiring community redevelopment, large-scale overhauls of city planning, gifts to the city in exchange for temporary land use, and the eventual dissolution of architecture into the landscape
Cattle-associated risk factors for human tuberculosis in rural livestock keeping communities, Uganda
No full textThesis (Master's)--University of Washington, 2017-06Tuberculosis (TB) is a leading infectious cause of human death worldwide. TB can also infect cattle, resulting in productivity losses, trade barriers, and zoonotic transmission via milk, meat, or direct contact. While the majority of TB cases are non-zoonotic, an unknown proportion are acquired from cattle; in Africa, this proportion is estimated to be 0.4% to 10%. We conducted a cross-sectional study in rural communities in southeastern and northwestern Uganda between 2014 and 2016 to evaluate the association between tuberculosis skin test (TST) positivity in humans and cattle-associated risk factors. Human and cattle skin testing was performed in communities followed by a survey of household practices. TST data are available on 493 humans, 250 men and 243 women; 184 individuals in total—111 men and 73 women—tested positive. Separate log binomial models were fit to estimate relative risks (RR) for herd TST positivity stratified on gender and for raw milk consumption, using generalized estimating equations. Having at least one TST positive bovid in the household’s herd was significantly associated with decreased risk of TB among men (PR 0.61, 95% CI 0.47, 0.79) but was not significantly associated with TB among women (PR 1.26, 95% CI 0.80, 1.97). This was contrary our a priori hypothesis of higher effect of exposure among men—the primary caretakers of cattle—than women. This apparent protective effect may be the result of residual confounding by socioeconomic status: wealthier individuals may be less likely to be TB positive, but more likely to have TST positive herds by virtue of larger herd sizes, ability to purchase new and possibly infected stock, and propensity to keep more TB-susceptible European breeds. For raw milk consumption, effect estimates were close to one and not statistically significant; adjustment for confounders or pathways mediated by exposure to non-zoonotic TB did not change the size or magnitude of effect estimates. The importance of cattle-associated risk factors for human TB burden may be setting-specific, as suggested by the lack of consensus reached by prior research. In settings where bovine TB prevalence is low, such as Uganda, cattle-associated zoonotic transmission may be rare
Statistical Angles on the Lattice QCD Signal-to-Noise Problem
No full textThesis (Ph.D.)--University of Washington, 2017-08The theory of quantum chromodynamics (QCD) encodes the strong interactions that bind quarks and gluons into nucleons and that bind nucleons into nuclei. Predictive control of QCD would allow nuclear structure and reactions as well as properties of supernovae and neutron stars to be theoretically studied from first principles. Lattice QCD (LQCD) can represent generic QCD predictions in terms of well-defined path integrals, but the sign and signal-to-noise problems have obstructed LQCD calculations of large nuclei and nuclear matter in practice. This thesis presents a statistical study of LQCD correlation functions, with a particular focus on characterizing the structure of the noise associated with quantum fluctuations. The signal-to-noise problem in baryon correlation functions is demonstrated to arise from a sign problem associated with Monte Carlo sampling of complex correlation functions. Properties of circular statistics are used to understand the emergence of a large time noise region where standard energy measurements are unreliable. Power-law tails associated with stable distributions and Levy flights are found to play a central role in the time evolution of baryon correlation functions. Building on these observations, a new statistical analysis technique called phase reweighting is introduced that allow energy levels to be extracted from large-time correlation functions with time-independent signal-to-noise ratios. Phase reweighting effectively includes dynamical refinement of source magnitudes but introduces a bias associated with the phase. This bias can be removed by performing an extrapolation, but at the expense of re-introducing a signal-to-noise problem. Lattice QCD calculations of the ρ+ and nucleon masses and of the ΞΞ(1S0) binding energy show consistency between standard results obtained using smaller-time correlation functions and phase-reweighted results using large-time correlation functions inaccessible to standard statistical analysis methods. A detailed study of the statistics and phase reweighting of isovector meson correlation functions demonstrates that phase reweighting can be used to predict ground-state energies of correlation functions that are too noisy to be analyzed by other methods. The relative precision of phase reweighting compared to standard methods is expected to be increased on lattices with larger time directions than those considered in this thesis, and these preliminary studies suggest phase reweighting of noisy nuclear correlation functions should be investigated on larger lattices. The results of this thesis suggest that phase reweighting may be applicable more broadly to real but non-positive correlation functions in quantum Monte Carlo simulations of particle, nuclear, and condensed matter physics systems as well as to complex correlation functions describing multi-baryon systems in LQCD