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Title: Assessing the Impact of Understanding Nature of Scientific Knowledge and Understanding Nature of Scientific Inquiry on Learning about Evolution in High School Students
Creator: Jimenez Pavez, Juan Paulo
Date: 2022
Description: Nature of Scientific Knowledge (NOSK) and Nature of Scientific Inquiry (NOSI) are important components of scientific literacy and important...
Show moreNature of Scientific Knowledge (NOSK) and Nature of Scientific Inquiry (NOSI) are important components of scientific literacy and important educational objectives in science education. Recent literature theorizes that understanding both NOSK and NOSI increases students' understanding of science content knowledge. However, this assumption has yet to be tested empirically. Much research has been done on developing informed views of NOSK and NOSI for students in kindergarten through twelfth grade, but research on the effect of understanding NOSK and NOSI on facilitating science learning in high school appears limited.The main purpose of this study was to empirically test the assumption that understanding NOSK and NOSI improves science student content learning, in particular learning about evolution. This study also aimed to determine which NOSK and NOSI aspects are most useful in such an endeavor. Using a quasi-experimental, nonequivalent control group design, a sample of 453 9th grade high school students from 12 classes in a large Chilean city were randomly assigned to intervention and control groups via classroom clusters (Intervention groups = 6, Control groups = 6). Students in the intervention groups were given a special online explicit and reflective five-week NOSK/NOSI Unit, followed by an online five-week Evolution Content Unit, as a treatment. Those in the control groups received only the online five-week Evolution Content Unit. To measure understanding of NOSK, understanding of NOSI, and understanding about evolution, students answered three valid and reliable instruments: The Views of Nature of Science (VNOS D+), the Views about Scientific Inquiry (VASI), and a multiple-choice Evolution Content Test. The students' answers to the VNOS D+ and VASI questionnaires were scored as naive, mixed, or informed according to the level of understanding for each aspect, and the answers to the evolution content test were scored as correct or incorrect. The results of this study showed that the NOSK/NOSI Unit was effective in improving understanding of NOSK and NOSI aspects in the intervention groups. The results also showed that the Evolution Content Unit was effective in improving understanding about evolution in both groups. However, students in the intervention groups outperformed their peers in the control groups by scoring higher on the Evolution Content Test. Further analysis revealed that students with informed views of NOSK and NOSI achieved better scores on the Evolution Content Test than students with naive views, supporting the argument that understanding NOSK and NOSI facilitates learning about evolution. In addition, all aspects except for the difference between Theories and Laws (NOSK) had a significant positive impact on learning about evolution. Taken together, the findings of this dissertation support the assumption that understanding NOSK and NOSI improves learning about evolution. Furthermore, most NOSK and NOSI aspects seem to foster understanding about evolution. These are new insights, especially about the importance of understanding NOSI for learning about evolution. Some limitations for this study include the remote context in which the study took place and the potential bias in the qualitative analysis of the VNOS D+ and VASI questionnaires.
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Title: ELECTROACTIVE COLLOIDAL MATERIALS DERIVED FROM POLYOXOMETALTES
Creator: Swenson, Lasalle
Date: 2018, 2018-05
Description: Polyoxometalates (POMs) are transition metal-oxide clusters formed by the early transition metals V, Mo, and W. As a subclass of metal oxides,...
Show morePolyoxometalates (POMs) are transition metal-oxide clusters formed by the early transition metals V, Mo, and W. As a subclass of metal oxides, POMs have a number of prototypical physical and chemical properties: solubility; thermal and solvent stability; Brønsted acidity; chemical and photochemical redox activity; photo- and electrochromism; and magnetic properties. POMs have been applied to a variety of technical areas, including catalysis, photocatalysis, biomedicine, and magnetism. As discreet molecular units having well-defined chemical properties, POMs are attractive building blocks for new materials whose properties could be rationalized in terms of their constituents at the molecular level. Towards that end, we have synthesized and characterized a series of new extended structure materials containing the organofunctionalized polyoxocationic species, [NaVIV 6O6{(OCH2CH2)2N(CH2CH2OH)}6]+ (NaV6 +). Three of the new materials are classified as POM ionic crystals and contain NaV6 + and Keggin polyoxoanions [(PW12O40)3-, (SiW12O40)4- or (SiMo12O40)4-] as molecular constituents: [NaVIV 6O6{(OCH2CH2)2N(CH2CH2OH)}6]3(PW12O40)·12H2O G1, [NaVIV 6O6{(OCH2CH2)2N(CH2CH2OH)}6]4(SiW12O40)·20H2O G2, and [NaVIV 6O6{(OCH2CH2)2N(CH2CH2OH)}6]3(HSiMo12O40)·13H2O G3. The final two materials (hereafter C1 and C2) are obtained as redistributable colloids derived from NaV6 + and the mixed-addenda Keggin structure polyoxoanion (PVW11O40)4- (VW11 4-). C1 contains the single polyoxocation constituent NaV6 +, while C2 contains both NaV6 + and VW11 4-. We have characterized the materials using PXRD, FTIR and UV-vis spectroscopy, TGA, SEM/EDX, elemental analysis, and cyclic voltammetry. G1, G2, and G3 are nanocrystalline and composite in nature, containing intact oxometallic cores of their respective polyoxoanion and polyoxocation building block units. Intercluster Coulombic interactions are the driving force of composite formation. These are the first materials derived from Coulombic interactions of polyoxoanions with covalently organo-functionalized polyoxocations. Cl and C2 are colloidal in nature and obtained in the form of micrometer-scale monoliths. They are the first POM-derived colloidal materials that are readily synthesized, isolated, and redistributed in practical quantities. The monoliths are insoluble in a variety of organic media including lower aliphatic alcohols. They readily form thin-films (δ < 100 um) by solvent casting. Owing to their extended nature, redistributable and isolable properties, the materials C1 and C2 may considered a new form of POM heterogenation. We use cyclic voltammetry (CV) to show that the constituents of the new materials are electrochemically addressable; a finding which opens the door to possible applications in sensing, energy storage and (electro-)chemical catalysis. With an eye towards technological applications, we demonstrate the systematic deposition of C2 onto indium tin oxide (ITO) using electrophoretic deposition, and show (CV) that we can access the electrochemical redox centers of its constituents following deposition. These materials demonstrate the activity of NaV6 + as a soft-chemical constituent partner to similar scale POM counter-anions, suggesting further synthetic investigations using this unique species. Owing to the redox properties of their constituents, the new materials present hybrid surfaces that may be considered intriguing prospective (multifunctional) heterogeneous oxidation catalysts. The electroactive nature of the materials also suggests prospective applications in energy storage and conversion, for example, as the active components of ion-insertion type capacitors and batteries. Electrocatalysis and sensing are also prospective application areas. The extended, as opposed to molecular, structure of the materials, suggests possible advantages when forming polymeric composites with conducting and nonconducting polymers, such as: an increased resistance to leeching, the emergence of favourable polymeric film mechanical properties, and the emergence of favorable electron and counterion tranport properties.
Ph.D. in Chemistry, May 2018
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Title: LENGTH DEPENDENT ACTIVATION IN MANDUCA SEXTA SKINNED FLIGHT MUSCLE
Creator: Wu, Yihong
Date: 2018, 2018-05
Description: The synchronous dorsolongitudinal muscle (DLM1) of the hawk moth, Manduca sexta has a number of characteristics similar to vertebrate cardiac...
Show moreThe synchronous dorsolongitudinal muscle (DLM1) of the hawk moth, Manduca sexta has a number of characteristics similar to vertebrate cardiac muscle. These muscles constitute a large proportion of the body weight and produce most of the force to depress the wings during flight. Crossbridges, consisting of myosin heads, form between the thin and thick filaments of the muscle fiber, and it is myosin head movement that causes muscle shortening and generates force. But the cycle cannot start without calcium bound to the troponin-tropomyosin complex, which expose the myosin binding sites on actin. It has been shown that cardiac muscle, as well as other muscles, exhibit myofilament length dependent activation where larger forces would be generated for a given calcium concentration at longer the sarcomere length (SL). The main goal in this thesis is to study the relationship of force-pCa of the DLM1 fibers as a function of sarcomere length. To establish these relationships, a series of calcium concentration solutions were prepared (pCa 4-8). The force was recorded as a function of the pCa at three different SL values. One aim of the thesis is to optimize the procedure for activation of the muscle fibers. Two different experimental protocols were used and their results were compared. The force-pCa relationships were plotted and fit to the Hill equation to analyze the cooperativity. The SL giving the highest force was 3.2 μm and the force-pCa relationship showed a sigmoidal shape with pCa50 of 6.01and the Hill coefficient was 19.6. Two protocols that were tried did not yield significantly different results, but no clear trends indicating myofilament length dependent activation were seen in these experiments in Manduca sexta flight muscle. However, protocol 2 showed a clearer demonstration of the cooperativity of the force-pCa relationships. The protocols used have better calcium binding to troponin-C (TnC) and larger Fmax than previous work in Irving lab. Future studies would be adding more data points with protocol 2 and analyzing if the trend changes.
M.S. in Molecular Biochemistry and Biophysics, May 2018
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Title: SYNTHESIS AND REACTIVITY OF ORGANOMETALLIC VAPOR PRECURSORS IN DEPOSITING THIN FILM MATERIALS
Creator: Zhang, He
Date: 2018, 2018-05
Description: Developing novel vapor precursors for vapor depositions such as atomic layer deposition (ALD) is critical for enabling new thin film materials...
Show moreDeveloping novel vapor precursors for vapor depositions such as atomic layer deposition (ALD) is critical for enabling new thin film materials and advanced processes. 2D materials such as transition metal dichalcogenides (TMDs) are promising materials for TFETs and diffusion barriers due to their narrow, direct band gap, and atomic thickness. In the potential electronic applications of TMDs materials, low-temperature, non-corrosive process is desired and even required to avoid thermal budget to the devices and sensitive components. Besides novel organometallic precursors, understanding the surface reaction mechanism is also necessary to achieve well-controlled material growth and obtain crystalline materials at lower temperature. In this dissertation, two novel synthetic methods to obtain crystalline TMDs materials such as tungsten disulfide (WS2) were developed, utilized metal hydride compound to synthesize at room temperature and heteroleptic compound to illustrate reaction mechanism. Reaction mechanism on the surface to produce metals chalcogenides including oxidation state changes and ligand behaviors during the nucleation using organometallic precursor on surfaces were investigated and observed with synchrotron X-ray absorption spectroscopy (XAS). Conventional tellurium sources have very limited reactivity towards tungsten. To overcome the low reactivities between W and Te sources, redox potential of organometallic Te and W precursors was utilized and achieved low-temperature synthesis of tungsten ditelluride (WTe2). Novel heteroleptic precursors design was also extended to Zr and Hf precursors. Heteroleptic Zr and Hf precursors were synthesized with high volatility and thermals stability. The heteroleptic precursors also showed high reactivity toward proton sources and selectivity between ligands. Metal chalcogenides deposition would be preferred with oxygen-free precursors. Organometallic precursors are typically more reactive than simple metal carbonyls or metal halides, and those organometallic precursors with a clear proton-transfer mechanism can allow ligands to be removed easily and obtain materials with high purity. Currently, tungsten precursors to synthesis TMDs material are commonly limited in metal carbonyls and metal chlorides, and the sulfurizations were performed at high temperature. By using more reactive organometallic precursors, the reaction between tungsten and chalcogenide sources can be initiated at lower temperature, highly reactive metal hydride and redox potential of metal complex were also utilized to boost reactivity. Well-designed ligands structures were employed to chemically enhance the crystallinity through the selectivity between ligands. Heteroleptic precursors are typically expected to have a better self-limiting control in synthesis, due to the different type of ligands could selectively react in each step. These enhanced precursor chemistries and understanding mechanism lead to better control of the synthesis of materials.
Ph.D. in Chemistry, May 2018
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Title: THE CHOLESTEROL LOWERING EFFECTS OF STRAWBERRY: A RANDOMIZED CONTROLLED TRIAL ESTABLISHING STRAWBERRYS' ROLE IN CARDIOVASCULAR HEALTH
Creator: Huang, Leailin
Date: 2018, 2018-05
Description: Cardiovascular diseases (CVD) represent the principal cause of morbidity and mortality worldwide. Recent studies suggest fruit and vegetable...
Show moreCardiovascular diseases (CVD) represent the principal cause of morbidity and mortality worldwide. Recent studies suggest fruit and vegetable consumption, especially berries, such as strawberry, is associated with lower risk of developing CVD. However, clinical trials demonstrating the specific risk factors affected by strawberry intake are not conclusive at present. Therefore, the objectives of this study were to assess strawberry intake on lipid and lipoprotein profile, endothelial function and blood pressure in individuals with moderate hypercholesterolemia. Thirty-four subjects (n=34) contributed to this analysis. This study was a randomized, double-blinded, placebo-controlled, cross-over, 12 week intervention design. Subjects were randomized to 1 of 2 study sequences in a 1:1 ratio. Sequence 1 was strawberry beverage, followed by 4 week wash out and crossover to placebo beverage. Sequence 2 was placebo beverage, followed by 4 week wash out and crossover to strawberry beverage. Subjects incorporated the strawberry or placebo beverage into their diet regularly (twice per day). Beverages were made from freeze-dried strawberries or a sensory and energy matched placebo powder. Strawberry containing beverages contained the equivalent of ~1.75 servings of fresh strawberries/beverage. Blood collection, anthropometrics, blood pressure and flow-mediated vasodilation (FMD) of the brachial artery were measured at baseline (week 0) and week 4, week 8 and week 12. Study findings showed that strawberry supplementation had overall treatment effects on increasing %FMD and decreasing systolic blood pressure compared to placebo (p=0.0096 and p=0.048, respectively). The 4 weeks strawberry supplementation did not significantly change anthropometric measures, lipid profile, glucose, insulin, and hs-CRP compared to placebo (p>0.05, all). Thus, strawberries may improve endothelial function and blood pressure, independent of other metabolic alterations, and may be considered an important fruit to include in a heart healthy diet in overweight or obese subjects with moderate hypercholesterolemia.
M.S. in Food Safety and Technology, May 2018
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Title: CAREGIVERS OF TRANSITION-AGE YOUTH WITH INTELLECTUAL AND DEVELOPMENTAL DISABILITIES: THE ROLE OF SELF-COMPASSION BETWEEN STIGMA AND PSYCHOLOGICAL ADJUSTMENT
Creator: Ivins-lukse, Melissa Nicole
Date: 2018, 2018-05
Description: Family caregivers of youth with intellectual and developmental disabilities (IDDs) often serve as life long caregivers for their family...
Show moreFamily caregivers of youth with intellectual and developmental disabilities (IDDs) often serve as life long caregivers for their family members. Little is known about the experiences of these caregivers during their youths’ transitional phase between adolescence and adulthood, particularly with regard to their experiences of selfcompassion, courtesy stigma, and wellbeing. As courtesy stigma (stigma experienced as a result of a person’s connection to a stigmatized individual) is associated with a variety of negative outcomes for caregivers, it is essential to identify protective factors to buffer caregivers from these effects. The present study surveyed 130 family caregivers of transition age youth with IDDs and tested positive aspects (“self-kindness”) and negative aspects (“self-coldness”) of self-compassion as potential mediators between courtesy stigma and caregiver psychosocial outcomes. Self-coldness partially mediated the relationship between courtesy stigma and caregiver life satisfaction (effect = -.13, CI = -.28 to -.03), while self-kindness did not. Both self-kindness (effect = .10, CI = .02 to .21) and self-coldness (effect = .17, CI = .07 to .30) partially mediated the relationship between courtesy stigma and caregiver depressive symptoms. Overall self-compassion (positive and negative aspects combined) was tested as a moderator of the relationships between courtesy stigma and caregiver psychosocial outcomes; no significant interactions were observed. Findings suggest self-compassion offers some protective effects from courtesy stigma for caregivers. Future research should seek to explore potential differences in these relationships according to caregiver gender or care recipient diagnostic group.
M.S. in Psychology, May 2018
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Title: ADAPTIVE QUADRATURE WITH A GENERAL ERROR CRITERION
Creator: Lu, Jiazhen
Date: 2018, 2018-05
Description: Numerical algorithms are required when the solutions to mathematical problems cannot be expressed analytically. Adaptive algorithms expend the...
Show moreNumerical algorithms are required when the solutions to mathematical problems cannot be expressed analytically. Adaptive algorithms expend the right amount of computational e↵ort to meet the error tolerance–easy problems require less e↵ort and hard problems require more e↵ort. Here we introduce a new globally adaptive trapezoidal rule algorithm satisfies a general error criterion, which includes both absolute and relative error tolerances. Then we derive the computational cost of the new algorithm and the complexity of this problem.
M.S. in Applied Mathematics, May 2018
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Title: GROWTH, SURVIVAL, AND INACTIVATION OF LISTERIA MONOCYTOGENES IN HUMMUS
Creator: Mhetras, Tanvi
Date: 2018, 2018-05
Description: Listeria monocytogenes is widely spread in the environment and is the causative agent of listeriosis. L. monocytogenes can contaminate ready...
Show moreListeria monocytogenes is widely spread in the environment and is the causative agent of listeriosis. L. monocytogenes can contaminate ready-to-eat (RTE) foods such as dairy products, salad dips, sandwiches, and seafood. In recent years, various recalls of hummus products have been reported to be associated with L. monocytogenes. This study aimed to 1) assess survival of L. monocytogenes on individual dry ingredients (chickpeas and sesame seeds), 2) examine survival of the pathogen in individual wet ingredients (mashed chickpeas and tahini) of hummus; 3) to evaluate L. monocytogenes survival in complete hummus dips; and 4) to determine L. monocytogenes inactivation in hummus dip using high pressure processing (HPP). Dry hummus ingredients (chickpeas and sesame seeds) were inoculated with a cocktail of four L. monocytogenes strains and stored at relative humidity (RH) levels of 25, 45, and 75% RH at 25 C for 28 d. When inoculated at 10 log CFU/g, L. monocytogenes populations decreased significantly (P<0.05) on sesame seeds and chickpeas in the first 24 h. The pathogen was more resistant to survival on sesame seeds at each of the RH levels than on chickpeas. The lowest D-value observed for L. monocytogenes was 9.90 d on chickpeas at 45% RH, while the highest value was 35.87 d on sesame seeds at 75% RH. When inoculated onto wet ingredients of hummus (mashed chickpeas and tahini), hummus dip, and hummus made using contaminated tahini or mashed chickpeas at 2 log CFU/g, L. monocytogenes was capable of survival in tahini during 28 d storage at 10 C. In mashed chickpeas, however, the pathogen increased significantly by approximately 4 log CFU/g after 7 d and had a growth rate of 2.21±1.34 log CFU/g/d. In hummus dip, L. monocytogenes had a significantly lower growth rate (0.11±0.01 log CFU/g/d) than in the mashed chickpeas. In hummus made using contaminated mashed chickpeas, the L. monocytogenes population significantly increased by 1.16 log CFU/g after 14 d. In hummus made using contaminated tahini, L. monocytogenes was capable of surviving, but did not grow. Hummus dip was treated with HPP at 350 MPa with holding times of 60,120,180 and 240 s. The D-value for L. monocytogenes was determined to be 98.2 seconds. The results from this study will aid in determining how L. monocytogenes survives in Refrigerated RTE hummus and its individual dry and wet ingredients. The study will also help in assessing the use of HPP for inactivation of L. monocytogenes in contaminated hummus.
M.S. in Food Safety and Technology, May 2018
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Title: ELASTIC ELEMENTS IN THE SARCOMERES OF STRIATED MUSCLE
Creator: Ma, Weikang
Date: 2016, 2016-07
Description: The flight muscle of the Hawkmoth, Manduca sexta, is an emerging model system for structure and function studies. M. sexta flight muscle shows...
Show moreThe flight muscle of the Hawkmoth, Manduca sexta, is an emerging model system for structure and function studies. M. sexta flight muscle shows several interesting properties such as its length tension curve is similar with cardiac muscle, but the detailed protein compositions of M. sexta flight muscle is not known. Here we identified proteins that might be responsible for the elastic properties of M. sexta flight muscle. 1% vertical SDS-agarose gel electrophoresis combined with western blot analysis was used to separate and identify high molecular weight proteins in M. sexta flight muscle. Two projectin isoforms as well as two kettin isoforms were found in M. sexta flight muscle. In addition, two high molecular weight proteins were seen in agarose gels which turned out to be Sallimus (Sls) proteins isoforms based on the sallimus (sls) gene map. The localization and orientation of projectin and Sallimus proteins were determined by immuno-localization using confocal microscopy. The thin and thick filament lengths were also determined, and shown to be consistent with the length tension curve data. Knowledge of myofilament compliance is critical in interpreting cross bridges kinetics interpretation and modeling. Here we used small angle X-ray diffraction to study thick filament compliance in intact mouse soleus muscle. The thick filament compliance was estimated by plotting the spacing changes of myosin based meridional reflections against tension generated by the muscle during contraction. A non-linear relationship of thick filament compliance was seen for the first time. Nebulin is a giant thin filament protein and has been proposed to play significant roles in muscle physiology, but the underlying mechanisms are largely unknown. A conditional nebulin gene knockout mouse model was used here to study any structural and functional changes caused by nebulin deficiency using small angle X-ray diffraction. The thin filament compliance was estimated, and the results showed that the thin filament compliance in nebulin deficient muscle was larger than muscle from control animals, whereas no difference was seen in thick filament compliance between knockout and control muscles. The inter-filament spacing was larger in knock out muscle than in control muscle, and less force was generated by each cross bridge. The larger interfilament spacing and less force per cross bridge might explain the muscle weakness seen in both the knock out mouse model, as well as in nemaline myopathy patients. Other structural changes caused by nebulin deficiency was also characterized by small angle X-ray diffraction.
Ph.D. in Molecular Biochemistry and Biophysics, July 2016
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Title: SUSTAINABLE URBAN DESIGN WITHIN CONTEMPORARY URBAN POLICY: A COMPARATIVE STUDY BETWEEN CHICAGO AND TAIPEI
Creator: Cheng, Chien-ke
Date: 2013, 2013-05
Description: This research and methodology develop a set of statistical measurements to evaluate sustainability – in terms of desired high urban density,...
Show moreThis research and methodology develop a set of statistical measurements to evaluate sustainability – in terms of desired high urban density, walkability for community amenity and convenience for everyday life – at the level of urban design for the cities of Chicago, USA and Taipei, Taiwan. The method, based upon GIS (Geographical Information System) technology, is used at this spatial level and for this type of academic study for the first time. The research analyzes and compares the percentage of each city’s population living within the “Quarter Mile Radius Sphere of Influence” (QMSI) for three classes of community amenities: parks, public elementary schools, and subway stations. The new and unique statistical data obtained in this thesis show a great disparity between the two cities. 1. Chicago has 31.98% of its population living within the QMSI of public elementary schools. Taipei has 49.64% of its population living within the QMSI of public elementary schools. 2. For subway stations, Chicago has only 8.09% of its population living in the QMSI, while Taipei has 25.99%. 3. For urban parks, Chicago has 44.06% of its population living in the QMSI, while Taipei has 88.80%. Further, based upon comparison, this research also discovers that the “sweet spot” areas – intersection of the QMSIs of all three community amenities – are mostly distributed along subway lines. With this indication, the research visualizes and supports the objective of improved public transit and walkability as key factors for sustainability in urban design in this case. The research also demonstrates the usefulness of GIS April 16, 2013 p.0B-xi PDD TF 0 20130416-13.doc xi technology’s new application in urban design studies for the future. The research shows that this new method has applicability for academic studies in other urban contexts, and for future international urban design and planning.
PH.D in Architecture, May 2013
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Title: ON THE LIST COLORING PROBLEM AND ITS EQUITABLE VARIANTS
Creator: Mudrock, Jeffrey Allen
Date: 2018, 2018-05
Description: In this thesis we study list coloring which was introduced independently by Vizing and Erd˝os, Rubin, and Taylor in the 1970’s. Suppose we...
Show moreIn this thesis we study list coloring which was introduced independently by Vizing and Erd˝os, Rubin, and Taylor in the 1970’s. Suppose we associate a list assignment L with a graph G which assigns a list, L(v), of colors to each v 2 V (G). A proper L-coloring of G, f, is a proper coloring such that f(v) 2 L(v) for each v 2 V (G). The list chromatic number of G, "`(G), is the minimum k such that G has a proper L-coloring whenever L is a list assignment satisfying |L(v)| ' k for each v 2 V (G). A graph G is said to be chromatic-choosable if "`(G) = "(G). The list chromatic number of the Cartesian product of graphs is not well understood. The best result is by Borowiecki, Jendrol, Kr´al, and Miˇskuf (2006) who proved that the list chromatic number of the Cartesian product of two graphs can be bounded in terms of the list chromatic number and the coloring number of the factors. In Chapter 2, we use the Alon-Tarsi Theorem and an extension of it discovered by Schauz in 2010 to find improved bounds on the list chromatic number and paint number (i.e. online list chromatic number) of the Cartesian product of an odd cycle or complete graph with a traceable graph. We also identify certain Cartesian products as chromatic-choosable. In Chapter 3, we generalize the notion of strong critical graphs, introduced by Stiebitz, Tuza, and Voigt in 2008, to strong k-chromatic-choosable graphs, and we show that it gives a strictly larger family of graphs that includes odd cycles, cliques, the join of a clique and any strongly chromatic-choosable graph, and many more families of graphs. We prove sharp bounds on the list chromatic number of certain Cartesian products where one factor is a strong k-chromatic-choosable graph satisfying an edge bound. Our proofs rely on the notion of unique-choosability as a sufficient condition for list colorability and the list color function which is a list analogue of the chromatic polynomial.In Chapter 4, we study a list analogue of equitable coloring introduced by Kostochka, Pelsmajer, and West in 2003. A graph G is said to be equitably kchoosable if it has a proper L-coloring that uses no color more than d|V (G)|/ke times whenever |L(v)| = k for each v 2 V (G). Generalizing a conjecture of Fu (1994) on total equitable coloring, we conjecture that for any simple graph G, its total graph, T(G), is equitably k-choosable whenever k ' max{"`(T(G)),"(G) + 2}. We prove this conjecture for all graphs satisfying "(G)  2 while also studying the related question of the equitable choosability of powers of paths and cycles. In Chapter 5, we introduce a new list analogue of equitable coloring: proportional choosability. For this new notion, the number of times a color is used must be proportional to the number of lists in which the color appears. Proportional kchoosability implies both equitable k-choosability and equitable k-colorability. Also,the graph property of being proportionally k-choosable is monotone, and if a graph is proportionally k-choosable, it must be proportionally (k +1)-choosable. We study the proportional choosability of graphs with small order and disconnected graphs, and we completely characterize proportionally 2-choosable graphs.
Ph.D. in Applied Mathematics, May 2018
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Title: SURVIVAL OF LISTERIA MONOCYTOGENES AND ESCHERICHIA COLI O157:H7 DURING AGING OF GOUDA CHEESE MADE USING UNPASTEURIZED MILK
Creator: Natarajan, Vidya
Date: 2018, 2018-05
Description: The FDA code of federal regulations states that cheeses made using unpasteurized milk must be aged for a period of at least 60 days to...
Show moreThe FDA code of federal regulations states that cheeses made using unpasteurized milk must be aged for a period of at least 60 days to minimize the inherent risks associated with unpasteurized milk. However, there have been several foodborne outbreaks associated with 60-day aged semi-soft cheeses made using unpasteurized milk, specifically Gouda cheese. In this study, Gouda cheese was manufactured using unpasteurized milk artificially-inoculated with Listeria monocytogenes (1 or 3 log CFU/mL) and Escherichia coli O157:H7 (1 log CFU/mL). The Gouda cheese was pressed, brined, waxed, and aged at 10°C for 90 (for the 1 log CFU/mL) or 150 (for the 3 log CFU/mL) days. Samples were assessed during cheese manufacture and aging for survival of the pathogen as well as for the population dynamics of the native microflora including Enterobacteriaceae, yeast and mold, lactic acid bacteria, and mesophilic bacteria. In addition, cheese samples during aging were also analyzed for property characteristics including salt and moisture content, fat in solid content, pH, and water activity. Results determined that the population levels of both pathogens significantly increased during manufacture. During aging of the Gouda cheese, E. coli O157:H7 was capable of survival only until 49 days and was henceforth not detected via enrichment. For L. monocytogenes, pathogen populations were 2.07±0.12 log and 1.26±0.00 log CFU/g at 60 and 90 days of aging, respectively, for the 1 log CFU/mL initial inoculation level. Compared to day 60 (2.31±0.92 log CFU/g) of aging, the population of L. monocytogenes for the Gouda cheese made with the 3 log CFU/mL initial inoculation level was significantly higher (p<0.05) on both 90 and 150 d of aging (4.62±0.25 and 6.00±0.72 log CFU/g, respectively). During aging, the populations of lactic acid and mesophilic bacterial were significantly higher than other microflora categories. The population of yeast and mold displayed an increasing trend in population, whereas Enterobacteriaceae populations were highly unsteady. Increases in lactic acid bacterial populations were accompanied by decreases in pH and pathogen populations. These results indicate that the characteristics of Gouda cheese and the native microflora population may play a pivotal role in survival and growth of pathogens. Overall, this study suggests that the current 60-day aging regulation, while sufficient to control E. coli O157:H7, may not be suitable to control the risk of L. monocytogenes in Gouda cheese.The population of yeast and mold displayed an increasing trend in population, whereas Enterobacteriaceae populations were highly unsteady. Increases in lactic acid bacterial populations were accompanied by decreases in pH and pathogen populations. These results indicate that the characteristics of Gouda cheese and the native microflora population may play a pivotal role in survival and growth of pathogens. Overall, this study suggests that the current 60-day aging regulation, while sufficient to control E. coli O157:H7, may not be suitable to control the risk of L. monocytogenes in Gouda cheese.
M.S.in Food Safety and Technology, May 2018
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Title: INITIAL VALIDATION OF AN OBSERVATIONAL MEASURE OF TEMPERAMENT IN PRESCHOOL-AGED CHILDREN
Creator: Plumb, Nora
Date: 2018, 2018-05
Description: Literature has shown that temperament predicts a range of childhood outcomes, including social competence, academic performance, and empathic...
Show moreLiterature has shown that temperament predicts a range of childhood outcomes, including social competence, academic performance, and empathic responsiveness. Temperament also has been consistently shown to be a risk factor for psychopathology (e.g., externalizing disorders, conduct problems, anxiety, and depression). Although there is general agreement on the definition of temperament, there are still aspects of this construct that are disputed (e.g., the specific traits involved and the degree to which they are stable across development). Moreover, researchers also have developed different strategies to assess this construct, specifically parent-report and direct observation, both of which have their limitations. Despite these limitations, very few measures temperament measures utilize ecologically valid observations in naturalistic settings. The purpose of this study was threefold. The first aim was to examine the construct validity of a newly-developed behavioral observation measure of temperament through confirmatory factor analysis (CFA). The second aim was to determine if the measure was invariant across age and gender. Finally, the third aim was to assess the measures’ convergent and predictive validity. This measure was administered to 796 children across three ages (i.e.,ages 4, 5, and 6). Results from the CFAs revealed that a four-factor structure was the best fit to the data at age 4, therefore supporting configural invariance across gender for that age group. Invariance testing also showed that the measure demonstrated metric, but not scalar, invariance across gender at age 4. Finally, this study found evidence for both convergent and predictive validity for this measure. Directions for future research are also discussed.
M.S. in Psychology, May 2018
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Title: IDENTIFICATION OF SURROGATE MICROORGANISMS AND USE OF PERACETIC ACID IN EXTENDED SHELF LIFE REFRIGERATED HIGH-ACID JUICE AND BEVERAGE PROCESSING
Creator: Stachler, Donna
Date: 2018, 2018-05
Description: The present study aim is to identify a surrogate microorganism that could be used in validation studies for Extended Shelf Life (ESL) chilled...
Show moreThe present study aim is to identify a surrogate microorganism that could be used in validation studies for Extended Shelf Life (ESL) chilled juice beverages with Peracetic Acid (PAA) in the processing system. Historically, Bacillus atrophaeus has been the primary surrogate, especially for aseptic systems with PAA; nevertheless this organism may be overly conservative for ESL processing that doesn’t have as high thermal temperature or PAA concentration. A baseline study was conducted to determine PAA resistance for B. atrophaeus spores. After being heat shocked at 82°C (179.6°F) for 13 minutes, 106 colony forming units per milliliters (CFU/mL) spores were spot inoculated and dried on stainless steel coupons. Then submerged in 200 ppm and 500 ppm VigorOx LS-15® PAA concentration, in two minute increments up to ten minute exposure time, at 50°C (122°F). The PAA reaction was halted and remaining spores were plated on Dextrose Tryptone Agar supplemented with yeast extract (DTA+ye), then incubated at 30°C (86°F) for 24 h. B. atrophaeus is PAA resistant and at least three log CFU/mL reduction was achieved for both concentrations at ten min exposure time. The next phase of the study was the selection of 15 different Bacillus species to conduct similar PAA resistance testing (with exposure time reduced to two and four minutes and additional 100 ppm of PAA) in an effort to evaluate which had the largest potential to be studied further. The three selected were B. pumilus, B. licheniformis (A) and B. licheniformis (B), due to high PAA resistance and similarity to B. atrophaeus inactivation. The three microorganisms were then studied against spoilage microorganisms (Aspergillus niger and Saccharomyces cerevisiae) and pathogenic microorganisms (Listeria monocytogenes, Salmonella species, and Escherichia coli O157:H7) at 200 ppm and 500 ppm PAA concentration. It was concluded that B. licheniformis (B) was the best overall surrogate with half log CFU/mL reduction at one minute and 200 ppm, as it was more resistant to PAA than A. niger and Salmonella. At 500 ppm PAA concentration B. atrophaeus continues to be best surrogate. Further studies, including testing to verify the behavior of B. licheniformis, as a surrogate, are recommended.
M.S. in Food Processing Engineering, May 2018
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Title: Adoption and Implementation of Diabetes Electronic Support Center at Mount Sinai Hospital, Summer 2011, IPRO 345: IPRO project plan
Creator: Kos, Carolyn, Valio, Nicole, Michael, Hazel, Chinzorig, Unubold, Johnson, Kendra
Date: 2011-06-17, 2011-07
Description: The purpose of IPRO 345 is to improve and mobilize the data and remote health care system for Mount Sinai Hospital. Specifically, this project...
Show moreThe purpose of IPRO 345 is to improve and mobilize the data and remote health care system for Mount Sinai Hospital. Specifically, this project aims to create a data support to aid diabetic patients within 500 meters of the hospital in order to decrease cost of operation and time and increase the quality of care. We will develop the groundwork for future IPRO 345 teams that will eventually implement the new data collection program.
Sponsorship: SolarWindUSA
Design+Prototype+Test an Integrated Roof-Top Photovoltaic Solar System Design, Summer 2011, IPRO 345
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Title: Adoption and Implementation of Diabetes Electronic Support Center at Mount Sinai Hospital, Summer 2011, IPRO 345: Midterm powerpoint
Creator: Kos, Carolyn, Valio, Nicole, Michael, Hazel, Chinzorig, Unubold, Johnson, Kendra
Date: 2011-06-17, 2011-07
Description: The purpose of IPRO 345 is to improve and mobilize the data and remote health care system for Mount Sinai Hospital. Specifically, this project...
Show moreThe purpose of IPRO 345 is to improve and mobilize the data and remote health care system for Mount Sinai Hospital. Specifically, this project aims to create a data support to aid diabetic patients within 500 meters of the hospital in order to decrease cost of operation and time and increase the quality of care. We will develop the groundwork for future IPRO 345 teams that will eventually implement the new data collection program.
Sponsorship: SolarWindUSA
Design+Prototype+Test an Integrated Roof-Top Photovoltaic Solar System Design, Summer 2011, IPRO 345
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Title: Adoption and Implementation of Diabetes Electronic Support Center at Mount Sinai Hospital, Summer 2011, IPRO 345: ipro 345 ethics
Creator: Kos, Carolyn, Valio, Nicole, Michael, Hazel, Chinzorig, Unubold, Johnson, Kendra
Date: 2011-06-17, 2011-07
Description: The purpose of IPRO 345 is to improve and mobilize the data and remote health care system for Mount Sinai Hospital. Specifically, this project...
Show moreThe purpose of IPRO 345 is to improve and mobilize the data and remote health care system for Mount Sinai Hospital. Specifically, this project aims to create a data support to aid diabetic patients within 500 meters of the hospital in order to decrease cost of operation and time and increase the quality of care. We will develop the groundwork for future IPRO 345 teams that will eventually implement the new data collection program.
Sponsorship: SolarWindUSA
Design+Prototype+Test an Integrated Roof-Top Photovoltaic Solar System Design, Summer 2011, IPRO 345
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Title: Beam Line Design for Fully Staged Two Beam Acceleration at the Argonne Wakefield Accelerator Facility
Creator: Neveu, Nicole
Date: 2018
Description: Two beam acceleration (TBA) is a candidate for future high energy physics machines and FEL user facilities. This is a scheme in which an...
Show moreTwo beam acceleration (TBA) is a candidate for future high energy physics machines and FEL user facilities. This is a scheme in which an electron accelerator uses a ``drive'' beam to transport and supply the RF power needed for acceleration on a secondary and independent 'witness' accelerator. This technology is attractive for its potential to improve the efficiency and simplicity of large scale machines. At the Argonne Wakefield Accelerator Facility (AWA), research into this potential accelerator scheme is ongoing. Completed experiments include a simplified staging set up, where high-charge, 65 MeV drive bunch trains were injected from the RF photoinjector into decelerating structures to generate a few hundred MW's of RF power. This RF power was transferred through an RF waveguide to accelerating structures that were used to accelerate the witness beam. Staging refers to the sequential acceleration (energy gain) in two or more structures on the witness beam line. The main limitation in past experiments was difficulty achieving 100\% transmission in the second stage which resulted in lower power generation. AWA plans to demonstrate fully staged TBA, which requires a separate beam line for each decelerating/accelerating pair. In this thesis, design specifications and initial hardware tests needed for a new, independent beam line for TBA was done. Simulations of the drive line were done using the code OPAL. Since OPAL was new to the AWA group, a benchmark comparison with ASTRA and GPT was done to validate initial results. Then two optimization algorithms were investigated and used to optimize the drive line at 40 nC. Comparison of results between the two algorithms were done, with no major discrepancies found. Then large scale and parallel optimizations were done for the optics configuration in the fully staged TBA beam line design. A kicker was designed and incorporated into the drive beam line to accomplish a modular design so that each accelerating structure can be independently powered by a separate drive beam. Experimental measurements of the kicker indicate the angle increases linearly with the supplied voltage, and the angle achieved meets the design requirements for fully staged TBA. Optics optimization was done to minimize the beam size at the center of the decelerating structures to ensure good charge transmission. The resulting design will be the basis for proof of principle experiments that will take place at the AWA facility.
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Title: LOW DIMENSIONAL SIGNAL SETS FOR RADAR APPLICATIONS
Creator: Alphonse Joseph Rajkumar, Sebastian Anand
Date: 2018
Description: In this dissertation we present a view in which the radar signals as the elements of a high dimensional signal set. The dimension is equal to...
Show moreIn this dissertation we present a view in which the radar signals as the elements of a high dimensional signal set. The dimension is equal to the number of discrete samples (M) of the signal. Because the radar signals should satisfy certain conditions for good performance, most lie in much smaller subsets or subspaces. By developing appropriate lower dimensional signal spaces that approximate these areas where the radar signals live, we can realize potential advantage because of the greater parametric simplicity. In this dissertation we apply this low dimensional signal concept in radar signal processing. In particular we focus on radar signal design and radar signal estimation. Signal design comes under radar measures and signal estimation comes under radar countermeasures.In signal design problem one searches for the signal element that has smaller sidelobes and also satisfies certain constraints such as bandwidth occupancy, AC mainlobe width, etc. The sidelobe levels are quantified by Peak Sidelobe Ratio (PSLR) and Integrated Sidelobe Ratio (ISLR). We use linear combination of these two metrics as the cost function to determine the quality of the designed signal. There is a lot of effort in designing parameterized signal sets including our proposed Asymmetric Time Exponentiated Frequency Modulated (ATEFM) signal and Odd Polynomial FrequencySignal (OPFS). Our contribution is to demonstrate that the best signal elements from these low dimensional signal sets (LDSS) mostly outperform the best signal elements that are randomly chosen from the radar signal subset with dimensionality M. Since searching the best signal element from the LDSS requires less computational resources it is prudent to search for the best signal elements from the low dimensional signal sets.In signal estimation problem we try to estimate the signal transmitted by a noncooperating radar which is intercepted by multiple passive sensors. The intercepted signals often have low SNR and there could be only few intercepted signals available for signal estimation. Predominantly used method for estimating the radar signals is Principal Component Analysis (PCA). When the SNR is low (< 0 dB) we need large number of intercepted signals to get an accurate estimates from PCA method. Our contribution is to demonstrate that by limiting the search for the best signal estimate within the low dimensional signal sets one can get more accurate estimates of the unknown transmitted signal at low SNRs with smaller number of sensors compared to PCA.
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Title: Structural Studies of Degradation Mechanism of Lithium Rich Manganese, Nickel, and Iron Based Cathodes
Creator: Aryal, Shankar
Date: 2018
Description: Layered oxide compounds are superior with respect to discharge voltage and discharge specific capacity compared to other families of cathodes....
Show moreLayered oxide compounds are superior with respect to discharge voltage and discharge specific capacity compared to other families of cathodes. Therefore, LiCoO2 and LiMnxNiyCozO2, are the most commonly used cathodes since the commercialization of lithium ion battery. Recently, Li rich Ni, Mn, and Co oxide composite cathodes have been introduced with some improvements. As Co is toxic and expensive, attempts have been made to replace Co with cheap and environmentally friendly Fe. This dissertation reports that comparable discharge specific capacity and discharge voltage can be achieved by replacing Co with Fe and optimizing the composition of Mn, Ni, and Fe. However, the capacity and voltage fading on cycling are still remaining challenges. Structural change on electrochemical cycling is the main reason behind this fading. X-ray absorption spectroscopy (XAS), the specific element probe technique to study local structure and X-ray diffraction (XRD) to study the crystallographic phase information are utilized to understand the degradation/aging mechanism. A series of Li rich Mn, Ni, and Fe oxide composite cathode materials Li1.2Mn(0.30+x)Ni(0.40-x)Fe0.10O2 for x = 0, 0.05, 0.10, 0.15, 0.20 and 0.25 were prepared using a sol-gel synthesis method. Rhombohedral and monoclinic crystal phases are found in Li rich Mn, Ni, and Fe composite oxide materials, but pure rhombohedral phase cannot be obtained without excess Li in the stoichiometric LiMO2 form. The pure monoclinic phase Li2MnO3 is also synthesized to confirm its presence in the composite oxide cathodes. Particle size and surface morphology are studied with scanning electron microscopy. The composite cathodes are cycled to over 100 cycles at 0.3C, for C = 250 mAhg-1 rate. XAS before and after 100 electrochemical cycles of Li rich Mn-Ni-Fe based cathodes is reported for the first time. The determination of fractional contents of monoclinic and rhombohedral phases in the composite oxide cathodes is not possible by powder XRD analysis, however, Li2MnO3 content decreases on decreasing Mn content and on increasing Ni content. The composition with higher Ni content has a higher degree of cation mixing. The synergistic effect of rhombohedral and monoclinic phases in Li rich Mn, Ni, and Fe based cathode is critical for stable electrochemical performance. The Li1.2Mn0.50Ni0.20Fe0.10O2 cathode showed the most stable cyclability performance (194 mAhg-1 first discharge capacity with 94 % capacity retention after 100 cycles at 0.3C rate) however, Li1.2Mn0.40Ni0.30Fe0.10O2 (220 mAhg-1 first discharge capacity with 57 % capacity retention) and Li1.2Mn0.55Ni0.15Fe0.10O2 (241 mAhg-1 first discharge capacity with 68 % capacity retention) cathodes showed higher 1st discharge capacity but poor cyclability under the same charge/discharge cycling.The XAS at Mn K-edge is used to explain the mechanism of Li2MnO3 activation for the improved electrochemical performance of Li rich Mn, Ni, and Fe oxide composite cathode, however Li2MnO3 contributed differently in different compositions. Synchrotron XRD and XAS measurements probed the lattice size expansion, which decreases the chemical potential of Li ions in the cathode on cycling leading to lower discharge voltage after cycling.
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