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Title: PREDICTORS OF FUNCTIONAL SOCIAL SUPPORT FOR ADULTS WITH BRAIN INJURY
Creator: Batchos, Elisabeth
Date: 2017, 2017-07
Description: Extensive research has demonstrated social support is a protective factor in the recovery process for people with disabilities. Following...
Show moreExtensive research has demonstrated social support is a protective factor in the recovery process for people with disabilities. Following acquired brain injury (ABI), individuals’ social networks dwindle, support declines, and isolation increases; thus, social support is a critical variable in combating these issues during the rehabilitation process. This study draws on the tri-dimensional model of social support to examine predictors of functional support for adults with ABI. Specifically, this study examines the impact of problem solving characteristics and structural (e.g., network composition) and appraisal (e.g., network helpfulness) support variables on two types of perceived functional support outcomes: emotional and instrumental support. Participants included 170 adults with ABI from across the United States who completed an online survey about their social and community experiences. Separate hierarchical regression analyses were used to examine predictors of two dependent variables: perceived emotional and instrumental support. Four variable sets were entered: (1) demographic and injury characteristics; (2) problem solving variables (approach-avoidance style, problem solving confidence); (3) structural support variables (number of roles in informal and formal networks, Internet use); and (4) appraisal support variables (perceived helpfulness of informal and formal networks). Together these variables accounted for 44% of the variance in emotional support outcomes (R² = .44, p < .001) and 34% of the variance in instrumental support outcomes (R² = .34, p < .001). Both analyses showed a similar pattern of predictors—namely, problem solving confidence and quality and quantity of informal network ties. However, Internet use was a significant predictor only of instrumental support while helpfulness of one’s formal network only predicted emotional support. Findings from this study highlight the common and unique variables that promote different types of functional support. Psychosocial functioning is often a meaningful goal for long-term recovery from ABI, and these findings can be used to target the development of psychosocial interventions designed to increase emotional and instrumental support. Such interventions would address a gap in many current rehabilitation programs by focusing on strategies designed to increase specific types of social support. Further, interventions to enhance social support promote a valuable rehabilitation construct, as social support has repeatedly been associated with improved outcomes in other aspects of health and wellness for people with ABI.
Ph.D. in Psychology, July 2017
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Title: PROFESSIONAL DEVELOPMENT AND TEACHER IMPACTS: THE NSF GK-12 EXPERIENCE
Creator: Camasta, Susan Fullett
Date: 2012-05-21, 2012-07
Description: Professional development is a central piece in the continuing education of teachers. The purpose of this study was to examine professional...
Show moreProfessional development is a central piece in the continuing education of teachers. The purpose of this study was to examine professional development for teachers, in particular, the impact of one program that has the potential to positively influence educators as their careers evolve. Twenty-seven teachers who served as participants in the National Science Foundation (NSF) Graduate STEM (science, technology, engineering and mathematics) Fellows in K-12 Education Program (GK-12) volunteered to be interviewed about their experiences as teacher partners with graduate student Fellows who were considered experts in their content area and research methods. The teachers taught 1st through 12th grades in 22 different schools, and represented nine GK-12 programs in six states. The data collected in this qualitative study indicate enduring impacts on teachers and those included: affective impacts, as well as impacts on their practice, their colleagues and their professional involvement. In addition, Fellow and student impacts were reported. The teacher reports indicate that the design and goals of the GK-12 program—which is meant to impact graduate student Fellows, teachers and students—are consistent with the literature on best-practice professional development including facilitating teacher change. Thus, this program can serve as a model for designing effective professional development. A limitation of this study is that most of the data collected were from teacher reports.
Ph.D. in Science Education, July 2012
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Title: SCREENING AND COMPARING GENES OF INTEREST IN MICROBIAL SPECIES USING WHOLE GENOME SEQUENCING
Creator: Butler, Robert Raymond Iii
Date: 2016, 2016-12
Description: This study utilized the latest advances in whole genome sequencing, assembly and annotation to develop high quality curated genomes, which...
Show moreThis study utilized the latest advances in whole genome sequencing, assembly and annotation to develop high quality curated genomes, which were compared to related organisms with differential traits to identify or characterize the trait-associated genes. Additionally, we were able to infer potential origins of these traits, and present gene targets for further study. Here we examined two biological phenomena: the desulfurization capability of a Paenibacillus species, and the exceptionally high spore heat resistance of Clostridium sporogenes PA 3679. Microorganisms with the capability to desulfurize petroleum are in high demand with escalating restrictions currently placed on fuel purity. Thermophilic desulfurizers are particularly valuable in high temperature industrial applications. A culture containing Paenibacillus naphthalenovorans 32O-Y and Paenibacillus sp. 32O-W was isolated by repeated passage of a soil sample at up to 55°C in medium containing dibenzothiophene (DBT) as sulfur source. Only 32O-Y metabolized DBT, apparently via the 4S pathway, however 32O-W enhanced DBT metabolism by 32O-Y in a mixed culture. Genome sequencing identified desulfurization gene homologs in the strains consistent with their desulfurization properties, with 32O-W lacking homologs for two necessary components of the 4S pathway. Both 32O-Y alone and the 32O-Y/32O-W mixed culture may be useful in development of an improved thermophilic petroleum biodesulfurization process. Clostridium sporogenes PA 3679 is a nonpathogenic, nontoxic model organism for proteolytic Clostridium botulinum used in the validation of conventional thermal food processes due to its ability to produce highly heat-resistant endospores. Because of its public safety importance, the uncertain taxonomic classification and genetic diversity of PA 3679 are concerns. Therefore, isolates of C. sporogenes PA 3679 were obtained from various sources and characterized using pulsed-field gel electrophoresis (PFGE) and whole-genome sequencing. The phylogenetic relatedness and genetic variability were assessed based on 16S rRNA sequence and whole-genome single nucleotide polymorphism (SNP) analysis. All C. sporogenes PA 3679 isolates were categorized into two clades. Clade I C. sporogenes isolates were genetically distinct from clade II isolates, and thermal destruction studies revealed that clade I isolates were more sensitive to high temperature than clade II isolates; clade II demonstrating the typical phenotype of PA 3679. A pan-genomic analysis of clade I and clade II isolates identified genes associated with PA 3679’s exceptional heat resistance. The most significant difference was the acquisition of a second spoVA operon, spoVA2, whose products are responsible for dipicolinic acid transport into the spore core during sporulation. The small acid-soluble spore protein ssp4 potentially plays a role in spore heat resistance, though further exploration is needed. spoVA2 was also found in some C. botulinum species clustering phylogenetically with PA 3679. Most other C. sporogenes examined both lack the spoVA2 locus and are phylogenetically distant within the group I Clostridia, adding to the understanding that C. sporogenes are dispersed C. botulinum strains lacking toxin genes. C. sporogenes strains are thus a very eclectic group, and few strains possess the characteristic heat resistance of PA 3679. Analysis from both Paenibacillus and Clostridium models revealed some interesting insights into genomic analysis that extrapolate to other projects. Each of the four generations of sequencing technology has remained a necessary component of genomics. The delineating factors for which sequencing tool to use depends heavily on the application they are being used for. New software for assembly and annotation are developed and released daily, and the challenge has become deciding which tools are actually an improvement over existing methodology. In order to best facilitate the large amount of genomic data in need of analysis, pipelines that are consistent and comprehensive are of higher value. Our studies identified many useful tools for future comparative analysis, and explored some novel ways to represent data in a visually appealing manner. As these tools and new ones continue to be developed, the value of genomics will increase with the new insights it provides.
Ph.D. in Biology, December 2016
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Title: SEISMIC COLLAPSE EVALUATION OF NON-DUCTILE CONCENTRICALLY BRACED FRAMES
Creator: Wen, Rou
Date: 2012-11-21, 2012-12
Description: More attentions have been paid on the Non-Ductile Concentrically Braced Frames (ND-CBFs) in low and moderate seismicity regions recently due...
Show moreMore attentions have been paid on the Non-Ductile Concentrically Braced Frames (ND-CBFs) in low and moderate seismicity regions recently due to their low ductility detailing requirements for design and construction. In this work, seismic collapse performances of two ND-CBFs are studied. One 3-story and one 9-story ND-CBF using small response modification coefficients (R=3) are designed firstly. Nonlinear finite element technologies are used to study the behaviors of local components. Practical analytical models for brace/gusset-plate assemblies and steel gravity frames are developed based on finite element simulations and engineering judgment. Three 2D structural models having increased local modeling complexity are developed for each braced frame. Nonlinear static pushover analyses on 3-story frames are conducted to get basic understandings of the damage evolution patterns and the interactions between main brittle braced frames and the steel gravity frames. Nonlinear dynamic analyses references the concepts of Incremental Dynamic Analysis are followed to investigate the seismic collapse responses of studied frames. The seismic assessments referenced the evaluation methods in FEMA P695 for ductile seismic load resisting frames through incremental dynamic analysis are carried out. Studied results show that Non-Ductile Concentrically Braced Frames would have little chance to prevent building collapse under severe ground motions. However, it seems that such buildings at least with low-to-moderate heights would have high probability of collapse prevention for up to moderate ground motions with conventional gravity framing systems used in modern steel buildings.
PH.D in Civil Engineering, December 2012
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Title: A NUMERICAL AND ANALYTICAL STUDY OF THE GROWTH OF SECOND PHASE PARTICLES USING A SHARP INTERFACE APPROACH
Creator: Barua, Amlan K.
Date: 2012-08-15, 2012-12
Description: Two phase alloys are quite important in materials science and metallurgy. Some common examples include nickel-aluminum system, iron-carbon...
Show moreTwo phase alloys are quite important in materials science and metallurgy. Some common examples include nickel-aluminum system, iron-carbon system etc. The most important macroscopic properties of these alloys depend on size, orientation and concentration of the second-phase precipitates. It is necessary to understand the details of formation, growth and equilibrium conditions of these micro-structures for better material production. In this dissertation we investigate the growth of the precipitates within the matrix using a sharp interface approach. We consider the effects of elastic fields on the evolution of the precipitates. The elastic fields can either be applied at the far field or can simply arise as a result of crystallographic difference between matrix and precipitate phase. The precipitates exhibit complicated morphology because of the Mullins-Sekerka instability. Our investigation is based on both analytical and numerical techniques. We use linear analysis to understand the qualitative behavior of the problem, at least for short time. To simulate the long time dynamics of the problem and to understand the effects of nonlinearity, we use highly accurate boundary integral methods. Our main contribution in this thesis is threefold. First, starting from linear analysis, we focus on the conditions under which stable growth, in presence of elastic field, is possible for a single precipitate. Finding such conditions are important in material production and simple conditions like constant material flux and constant elastic fields produce precipitates with complicated shapes. Second, we propose a space-time rescaling of the original boundary integral equations of the problem. The rescaling enables us to accurately simulate very long time behavior of the system comprising of multiple precipitates growing under different mass flux and elasticity. It also helps us to understand the long time interaction of precipitates. Third, we xiii implement an adaptive treecode to reduce the computational complexity of the iterative solver from O(N2) to O(N logN) where N is the dimension of the discrete problem. The efficiency of the treecode is demonstrated by performing simulations. Also a parallelization strategy for the treecode is discussed. The speed-up from the parallelization is demonstrated using moderate number of cores. xiv
PH.D in Applied Mathematics, December 2012
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Title: DEVELOPING MATHEMATICAL KNOWLEDGE FOR TEACHING: DOCUMENTING PRESERVICE ELEMENTARY TEACHERS' EXPERIENCES
Creator: Kwiatkowski-egizio, Erica
Date: 2013, 2013-07
Description: The two research questions that guided this study were: (1) How do preservice teachers develop mathematical knowledge for teaching during a...
Show moreThe two research questions that guided this study were: (1) How do preservice teachers develop mathematical knowledge for teaching during a coordinated math methods course and field experience? and (2) What types of portfolio tasks lend themselves to documenting mathematical knowledge in teaching? Six, female, elementary (K-8) teacher candidates who were co-enrolled in Math Methods, K-9, and Field Experience II, during the 15-week, fall 2012 semester at Lewis University were the participants in this study. The six teacher candidates all completed their field experiences in the same K-8 school, St. Joseph, in Lockport, Illinois. Three of the teacher candidates had elementary placements (grades K, 1, and 4) and three of the teacher candidates had middle school placements (5, 6, and 7). Each of the teacher candidates completed pretest and post-test DTAMS assessments. All candidates taught three mathematics lessons, which were videotaped and observed by the researcher. After each lesson was taught, a debriefing interview on the strengths, improvements, and next steps was conducted. Math Methods class sessions and Field Experience II seminars were recorded. Finally, each teacher candidate submitted a Math Teaching Portfolio. Results illustrated the growth of mathematical knowledge for teaching that occurred for each participant. In addition, results indicated which portfolio tasks are best for documenting mathematical knowledge for teaching. Implications for the field of mathematics education, future research, and teacher preparation programs are also discussed.
PH.D in Mathematics Education, July 2013
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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: RECURRENT PREGNANCY LOSS: PSYCHOLOGICAL SEQUELAE AND COPING
Creator: Grathouse, Heidi Richelle
Date: 2016, 2016-05
Description: Recurrent pregnancy loss has received little attention in the research literature despite being recognized as a source of distress. This study...
Show moreRecurrent pregnancy loss has received little attention in the research literature despite being recognized as a source of distress. This study examined 126 participants who were either in a recurrent pregnancy loss group (as defined by the ASRM guidelines of 2 or more miscarriages occurring within the first trimester of pregnancy) or a nonpregnancy loss community group. This study tested the hypothesis that depression and anxiety symptoms, as measured by the IDAS would be different for the group of persons that had experienced RPL as compared to the community sample. It was expected that individuals who had experienced RPL would have significantly higher levels of depression and anxiety than the community group. This hypothesis was based upon the finding that elevated anxiety and depressive symptoms are common, and major depressive disorder has been reported at a rate of 10-50% following a miscarriage (Conway & Russell, 2000; LaRoche, et al. 1984). The findings failed to support this hypothesis. The second hypothesis stated that coping styles, as measured by the COPE, would be related to levels of distress as measured by the IDAS. Specifically, active-emotion-focused coping and avoidant coping would be related strongly to negative affect, consistent with research by Folkman and Lazarus (1986), in which it was shown that depressed individuals used relatively less problem-focused coping than non-depressed individuals. Results from this study partially supported this hypothesis and the previous findings.
Ph.D. in Psychology, May 2016
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Title: DESIGN OF MODERN HIGH NB-CONTENT ,-,' NI-BASE SUPERALLOYS
Creator: Antonov, Stoichko
Date: 2017, 2017-07
Description: Superalloy design can prove to be a very complex and challenging task, as certain elemental additions can significantly improve properties...
Show moreSuperalloy design can prove to be a very complex and challenging task, as certain elemental additions can significantly improve properties when added in high contents, however, exceeding their solubility limits can promote the formation of undesired phases at grain boundaries as well as grain interiors, and can quickly deteriorate the high temperature structural integrity and stability of the alloy, resulting in a catastrophic failure. Precipitate phases, such as " and ⌘, appear similar and are often mistaken for one another, leading to the need for a better fundamental understanding of their formation, required for developing innovative new classes of Ni-base superalloys. The morphology, formation, and composition of precipitate phases in a number of experimental alloys spanning a broad range of compositions were explored and compositional relationships were developed to facilitate the design of !-!0-("/⌘) Ni-base superalloys. The e↵ect of increasing Nb alloying additions on the formation and long term phase stability of topologically close packed (TCP) phases was studied. Elevated levels of Nb can result in increased matrix supersaturation and promote the precipitation of ⌘-Ni6AlNb along the grain boundaries in powder processed, polycrystalline Ni-base superalloys, while reduced Nb levels favored the precipitation of blocky Cr and Mo rich $ phase precipitates along the grain boundary. Evaluation of the thermodynamic stability of these two phases using Thermo-Calc showed that while $ phase predictions are fairly accurate, predictions of the ⌘ phase are limited. In addition, atom probe tomography (APT) was used to quantitatively assess grain boundary phase compositions and local segregation along the grain boundary before and after a 1000 hour thermal exposure at 800 "C. The complex network of $ phase precipitates that formed upon the thermal exposure and the characteristic interfacial segregation profiles were studied. In addition, elemental boron was observed to segregate to the grain boundary and phase interfaces, but did not form borides, due to the relatively low concentration of B atoms, resulting from a higher B concentration in the matrix. APT studies were also performed on MC carbides of the alloys and the formation kinetics and morphological differences between NbC and Hf doped NbC were explained using density functional theory (DFT) calculations of the formation energies of different facets of the MC carbide. Detailed electron microscopy and APT techniques were then used to systematically quantify the chemical and morphological instabilities that occur during aging of polycrystalline !-!0 Ni-base superalloys containing elevated levels of refractory alloying additions. The morphological changes and splitting phenomenon associated with the secondary !0 precipitates were related to the discrete chemical compositions of the secondary and tertiary !0 along with the phase compositions of the ! matrix and the ! precipitates that form within the secondary !0 particles. Compositional phase inhomogeneities led to the precipitation of finely dispersed tertiary !0 particles within the ! matrix and secondary ! particles within the secondary !0 precipitates, which, along with surface grooving of the secondary !0 particles, contributed to the inverse coarsening or splitting of the precipitates during aging. As recent studies have shown that polycrystalline Ni-base superalloys containing elevated levels of Nb additions exhibit superior properties at elevated temperatures when compared to existing commercial Ni-base superalloys, understanding of elemental partitioning to each phase is essential and was studied via APT. Compositions of the constituent phases were measured in four high Nb-content !-!0 Ni-base superalloys and the results were compared to thermodynamic database models from Thermo-Calc. Results were also used to predict the solid solution strength behavior of the four alloys. The di↵erences in phase composition predictions from thermodynamic models resulted in dissimilarities between the generated strength behavior curves and those from the experimental work. Finally, creep behavior of high Nb-content !-!0 Ni-Based superalloys was related to the formation of secondary phases mainly at grain boundaries. As secondary phases form, their brittle nature leads to crack formation, which can propagate under the tensile load and lead to premature failure of the alloy.
Ph.D. in Materials Science and Engineering, July 2017
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Title: THE ROLE OF MOLECULAR MOTORS IN THE MECHANICS OF ACTIVE GELS AND THE EFFECTS OF INERTIA, HYDRODYNAMIC INTERACTION AND COMPRESSIBILITY IN PASSIVE MICRORHEOLOGY
Creator: Uribe, Andres Cordoba
Date: 2014, 2014-07
Description: The mechanical properties of soft biological materials are essential to their physiological function and cannot easily be duplicated by...
Show moreThe mechanical properties of soft biological materials are essential to their physiological function and cannot easily be duplicated by synthetic materials. The study of the mechanical properties of biological materials has lead to the development of new rheological characterization techniques. In the technique called passive microbead rheology, the positional autocorrelation function of a micron-sized bead embedded in a viscoelastic fluid is used to infer the dynamic modulus of the fluid. Single particle microrheology is limited to fluids were the microstructure is much smaller than the size of the probe bead. To overcome this limitation in two-bead microrheology the cross-correlated thermal motion of pairs of tracer particles is used to determine the dynamic modulus. Here we present a time-domain data analysis methodology and generalized Brownian dynamics simulations to examine the effects of inertia, hydrodynamic interaction, compressibility and non-conservative forces in passive microrheology. A type of biological material that has proven specially challenging to characterize are active gels. They are formed by semiflexible polymer filaments driven by motor proteins that convert chemical energy from the hydrolysis of adenosine triphosphate (ATP) to mechanical work and motion. Active gels perform essential functions in living tissue. Here we introduce a single-chain mean-field model to describe the mechanical properties of active gels. We model the semiflexible filaments as bead-spring chains and the molecular motors are accounted for by using a mean-field approach. The level of description of the model includes the end-toend length and attachment state of the filaments, and the motor-generated forces, as stochastic state variables which evolve according to a proposed differential Chapman- Kolmogorov equation. The model allows accounting for physics that are not available in models that have been postulated on coarser levels of description. Moreover it allows the prediction of observables at time scales that will be too difficult to achieve in multi-chain simulations.
Ph.D. in Chemical Engineering, July 2014
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Title: THE EFFECTS OF ORGANIZATIONAL REPUTATION AND COMMUNITY DEMOGRAPHICS ON APPLICANT POOL COMPOSITION AND ETHNIC GROUP TEST SCORE DIFFERENCES IN PUBLIC SAFETY SELECTION
Creator: Anderson, Rebecca C.
Date: 2017, 2017-05
Description: Efforts to increase minority hiring rely on having a large pool of qualified minority candidates. The current study examined the effects of...
Show moreEfforts to increase minority hiring rely on having a large pool of qualified minority candidates. The current study examined the effects of police department reputation (as reflected in news stories), workforce demographics, and community demographics (i.e., the proportion and segregation of minorities in the community) on minority representation among applicants to police jobs, as well as adverse impact on a police selection test. Only negative department reputation predicted test score, although it was not related to adverse impact. However, the size of group differences did vary significantly across police departments. Implications for future research and for practice are discussed.
Ph.D. in Psychology, May 2017
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Title: MEMBRANE-DRUG INTERACTION MECHANISMS OF PEPTOID-BASED ANTIMICROBIAL AGENTS
Creator: Andreev, Konstantin
Date: 2017, 2017-05
Description: Nature is a major source of inspiration for drug design. Bacteria are developing resistance towards conventional antibiotics. Utilizing...
Show moreNature is a major source of inspiration for drug design. Bacteria are developing resistance towards conventional antibiotics. Utilizing antimicrobial peptides (AMPs) – an essential component of innate immune system, as therapeutic agents, may be a viable alternative. Unfortunately, there are a number of serious hurdles on the way towards clinical application of AMPs, including their low bioavailability, costly manufacturing process and toxicity against host cells. To address this issues, current research is focused on the design of synthetic compounds mimicking natural peptides, among which oligo(Nsubstituted glycines), or peptoids, have shown great promise. Antimicrobial drug efficacy is defined by how it interacts with the membrane of invading pathogen. The physicochemical characteristics of peptoid molecule play a crucial role in these interactions, yet their detailed structure-activity relationships remain obscure. Herein, we have demonstrated that conformational flexibility, cationic charge or hydrophobicity, are critical for oligomeric peptoids to permeate bacterial cell membranes. The outer surface of membrane was modeled by Langmuir monolayers of desired lipid composition and subjected to the constant-pressure insertion assays, epifluorescence microscopy (EFM), synchrotron X-ray reflectivity (XR) and grazing incident-angle X-ray diffraction (GIXD). Our results shed light on the critical details in peptoid mode of action. We believe this will aid in the rational design and of novel anti-infective drugs. Additionally, we have applied our experimental system to model the processes occurring at the air-water interface in lungs. Alveoli are coated by a complex lipidprotein mixture referred to as pulmonary surfactant. This facilitates respiration and prevents alveolar collapse. Patients with respiratory distress receive surfactant replacement therapy that often has the serious drawbacks. X-ray scattering data shows that the structural organization of adsorbed films correlates with surfactant delivery methods onto the respiratory surface. We anticipate that our findings will contribute to the development of novel clinical approaches for treating respiratory diseases.
Ph.D. in Biology, May 2017
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Title: THE PEDAGOGY OF INGENUITY IN SCIENCE: AN EXPLORATION OF CREATIVE THINKING IN THE SECONDARY SCIENCE CLASSROOM
Creator: Antink, Allison
Date: 2012-07-17, 2012-07
Description: The importance of creative thinking in science cannot be overstated. Creativity is integral to the development of knowledge about the natural...
Show moreThe importance of creative thinking in science cannot be overstated. Creativity is integral to the development of knowledge about the natural world and the knowledge, skills and abilities that support it are in need of greater understanding. The Next Generation Science Standards (2012) include practices that implicitly emphasize the creative thinking in science that students should develop by the 12th grade. These science practices were utilized in a framework to explore a group of secondary science classrooms in order to investigate potential relationships between classroom variables and student creative thinking in science. A measure of scientific creative thinking (Hu & Adey, 2002) was used with 284 student participants from 21 different classes, six different schools and from seven different teachers. Students’ performance on a pre to post-administration of the measure was compared against case studies that were developed of each classroom to determine trends. Those case studies were developed across one semester using 2-3 observations per class per semester and the collection and analysis of teachers’ labs and other instructional materials. The outcomes of a pre to post-administration of the measure, when coupled with the case studies, suggested three distinct trends in relationships between classroom variables and students’ scientific creative thinking. These trends: originality in the use of scientific tools, originality and variety in the development of scientific questions, and the role of context in the development of original, engineering-type design tasks are discussed in the context of research on creative thinking in science and in the science practices in the Next Generation Science Standards (NRC, 2012).
Ph.D. in Science Education, July 2012
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Title: An Integrated Cell Culture-PCR Assay for the Detection of Viable Coxiella Burnetii Nine Mile Phase II RSA 439 in Fluid Dairy Products
Creator: Kukreja, Ankush
Date: 2011-12, 2011-12
Description: Coxiella burnetii, an obligate intracellular bacterium, has been used as the reference organism for defining milk pasteurization conditions....
Show moreCoxiella burnetii, an obligate intracellular bacterium, has been used as the reference organism for defining milk pasteurization conditions. With renewed interest in minimizing processing times and temperatures, and in ensuring product safety, development of an Integrated Cell Culture-PCR (ICC-PCR) assay may be useful for evaluating C. burnetii inactivation in fluid dairy products. The purpose of this research was to develop an ICC-PCR assay to determine viability and detection limit of C. burnetii and characterize inhibiting effects contributed by various milk formulations. Coxiella burnetii was inoculated on Vero cell culture with PBS and whole milk, incubated for 48 hours to allow infection, and then incubated for 11 days to allow propagation. The propagated C. burnetii mix was subjected to freeze-thaw followed by DNA extraction with Autogen Blood & Tissue DNA Extraction Kit using Quickgene Mini80. Extracted DNA was amplified using TaqMan-MGB based qPCR targeting published primers for the IS1111a transposase gene to verify C. burnetii growth/infectivity. For detection limit determination, serial dilutions of C. burnetii in RPMI were mixed separately in whole milk, cream, chocolate milk and eggnog. The mix was overlaid on sub-confluent Vero cell monolayers, subjected to freeze-thaw followed by DNA extraction using Autogen Blood & Tissue DNA Extraction Kit and PCR. Uninoculated wells were evaluated for dairy sample background signal, and inhibition was evaluated by comparison to purified DNA. Duplicate trials using 6 replicates per sample were performed.
M.S. in Food Safety & Technology, December 2011
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Title: COMMUNICATION, LEADERSHIP, AND VIRTUAL TEAMS
Creator: Robinson, Joy D.
Date: 2014, 2014-05
Description: A self-managing virtual (SMV) team is a configuration that permits team leaders to manage and administer their team with limited supervisory...
Show moreA self-managing virtual (SMV) team is a configuration that permits team leaders to manage and administer their team with limited supervisory oversight. These teams are widespread in software and engineering environments where resources may be scattered globally (Yukl, 2009). Research into SMV team leadership is, however, in its early stages. Scholars have yet to confirm that traditional leadership theories operate in this theater. Additionally, the slate of leader roles that describe leadership and how these leaders affect success is not well understood. Research into emergent leadership provides limited insight into virtual teams, but current research fails to examine how emergent leaders manifest in the presence of an appointed leader. This study examines the relationship between emergent leadership and team success using the Behavioral Complexity Leadership theory or Leaderplex. In the experiment, two virtual teams attempted a series of interdependent, complex tasks across a series of weeks. This analysis confirmed that leader roles could adequately describe leadership in virtual teams. SMV leaders focused specifically on the Monitor role with the remaining roles left distributed among the membership. The appointed leader condition did not suppress leader roles, however, in this study the appointed leader negatively affected team performance. Lastly, two perspectives (Perception and Practice) showed little correlation between leader roles. The study, conducted using the synthetic milieu of a popular MMO --World of Warcraft, served to push the envelope of permissible social science research environments.
PH.D in Technical Communication, May 2014
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Title: A COUPLED LAGRANGIAN-EULERIAN MULTIPHASE MODEL FOR SIMULATION OF WIND TURBINES PERFORMANCE UNDER RAINY CONDITIONS
Creator: Cohan, Aiden C.
Date: 2016, 2016-05
Description: Wind Turbines power output is constantly influenced by their environmental conditions, including raining and icing. Therefore, understanding...
Show moreWind Turbines power output is constantly influenced by their environmental conditions, including raining and icing. Therefore, understanding the effect of rain is necessary to enhance the efficiency of the wind turbines used in regions with considerable number of rainy days and below freezing temperatures. We developed a multiphase computational fluid dynamics (CFD) model to estimate the effect of rain by simulating the actual physical process of rain droplets forming a water layer over the blades by coupling the conventional Lagrangian Discrete Phase Model (DPM) and the Eulerian Volume of Fluid (VOF) models. We first applied our model to the National Renewable Energy Laboratories (NREL) S809 airfoil used in the blade profile of horizontal-axis wind turbines (HAWT) and studied the effect of rain at different rainfall rates in addition to the effect of surface tension and surface property of the airfoil. Our simulations showed that surface tension has a dominant effect on the performance of the airfoil and should not be neglected under simulated rainy conditions. It also was observed that, under rainy conditions, an airfoil with non-wetting surface has an inferior performance (lower lift and higher drag coefficient) compared to an airfoil with wetting surface due to the added roughness caused by water on the non-wetting surface, which is in line with experimental observations. We also observed that, at low rainfall rates, the performance of the airfoil is highly sensitive to the rainfall rate. However, if the rainfall rate is high enough to immerse most of the airfoil surface under water, a further increase in the rainfall rate does not have a substantial effect on the performance of the airfoil. We also investigated the effect of rain at different angles of attack for two rainfall rates. We started by running single phase cases and observed that our results agreed well with experimental data. We then ran multiphase cases and observed that, lift coefficient increases with angle of attack even past the stall angle compared to the single phase case. However, this favorable increase in lift is accompanied by an increase in the drag coefficient which is greater at larger angles of attack. Finally, we simulated the performance of an actual 3D wind turbine (NREL phase VI horizontal axis wind turbine) for single phase cases at various wind speeds, in addition to, a multiphase case (under rainy conditions) using our multiphase model. Our single phase results compared well with experimental data. We had to use a simplified version of our multiphase model for the multiphase 3D simulation in order to make it computationally affordable. We observed that rain can reduced the performance of the NREL phase VI wind turbine by about 5% at a wind speed of 7.02 m/s and a rainfall rate of 40 mm/hr. Even though we used our multiphase model to simulate water layer formation from rain droplets, the physical concepts used in developing the model are very general and are not limited to this specific problem. Our model can be used to simulate any problem that involves particles hitting a surface and forming a liquid phase. For example, it can be used to model spray painting of a surface as the spray droplets form a paint layer on the surface.
Ph.D. in Mechanical, Materials and Aerospace Engineering, May 2016
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Title: CABLE ACTUATED FINGER EXOSKELETON DEVELOPMENT AND EXAMINATION OF INDEX FINGER AND THUMB COUPLING
Creator: Jones, Christopher L.
Date: 2014, 2014-05
Description: Finger-thumb coordination is crucial to interacting with our environment. This coordination remains incompletely understood, even in...
Show moreFinger-thumb coordination is crucial to interacting with our environment. This coordination remains incompletely understood, even in neurologically intact individuals, and is difficult to study with current interface devices. Knowledge of finger-thumb relationships during dynamic movement facilitate identification of key impairment mechanisms following stroke and thus, help to guide rehabilitation strategies. Accordingly, a high-bandwidth, biocompatible finger exoskeleton is developed and implemented in a pilot study to investigate coupling between the finger and thumb during pinching movements. Performance of the Cable Actuated Finger Exoskeleton (CAFE) is analyzed in the lab and during interaction with human subjects, both neurologically intact and survivors of stroke. The exoskeleton is found to perform exceedingly well, exceeding nearly all design requirements lending to the continued use of the CAFE a research platform for human motor control of the hand. During experimental trials, participants move through index finger and thumb palmar pinching movements while the CAFE delivers perturbations during the closing and opening phases of movement. Two experiments are conducted, delivering reflexinducing or joint-locking perturbations to the index finger. Muscle EMG and thumb tip trajectory are recorded during movement and variations in these parameters immediately following perturbation demonstrate the effect of coupling of the index finger and thumb. Reflexive coupling is evidenced in both healthy and post-stroke individuals by heteronymous reflexes in the unstretched muscles of the thumb. Similarly, kinematic changes are apparent in thumb movement following impedance perturbations of the index finger in both populations. Coupling is observed to vary with phase of movement in x xiii intact participants, but not following stroke, suggesting a loss of modulation following stroke. Most notably: in survivors of stroke impedance perturbations to the index finger during the opening phase of movement results in dramatically increased thumb opening.
PH.D in Biomedical Engineering, May 2014
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Title: STRUCTURE-PROPERTY RELATIONSHIPS IN ANION EXCHANGE MEMBRANES FOR ELECTROCHEMICAL ENERGY CONVERSION AND STORAGE
Creator: Arges, Christopher George
Date: 2013, 2013-12
Description: Polymer electrolyte membrane (PEM) fuel cells are promising candidates for powering automotive vehicles, but their advancement has been...
Show morePolymer electrolyte membrane (PEM) fuel cells are promising candidates for powering automotive vehicles, but their advancement has been hindered by the costs associated with their platinum-based electrocatalysts. One strategy to resolve this problem is to replace the conventional acidic PEM with an alkaline anion exchange membrane (AEM) because fuel cells operated in alkaline media do not require platinum group metal catalysts. A significant challenge to realizing this concept is to design and implement an AEM that is chemically robust under alkaline conditions and that facilitates high ionic conductivity. This dissertation presents a scientific approach to address the aforementioned problems through investigation of alternative cations, beyond quaternary trimethylammonium, to understand what chemical features influence ion conductivity and alkaline stability. It was postulated that selecting cations with larger free base conjugate pKA values (i.e., greater basicity) would yield improved AEM alkaline stability and ionic conductivity. The pKA value accounts for the steric hindrance, inductive, and resonance features of an organic cation and these features influence a cation’s interaction with hydroxide. Udel® polysulfone (PSF) and poly(2,6-dimethyl 1,4-phenylene) oxide (PPO) were selected as the model polymer backbones because they can be tailored with different cation groups. The types of cations assessed were of the quaternary ammonium and phosphonium types and 1-methylimidazolium. The prepared AEMs demonstrated a direct correlation between the cation’s free base conjugate pKA and anion conductivity for most cations assessed. Alkaline stability was assessed through multi-dimensional NMR to determine the degradation products in AEMs. NMR confirmed that the cation groups x xxii degraded through fundamentally different degradation mechanisms dependent upon their chemical make-up. Because the degradation mechanisms were different, the rate of degradation of the cation groups did not demonstrate a correlation to the cation’s free base conjugate pKA. If the cations did proceed through the same degradation mechanism, then a correlation was observed. Additionally, it was discovered that the cation groups in PSF and PPO triggered polymer backbone degradation in alkaline despite the resiliency of both these pristine polymers in alkaline solutions. The AEMs prepared were successfully demonstrated in several electrochemical energy storage and conversion technologies (including alkaline fuel cell, alkaline water electrolyzer, and the all-vanadium redox flow battery).
PH.D in Chemical Engineering, December 2013
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Title: ASSESSMENT METHODS AND TOOLS FOR ARCHITECTURAL CURRICULA
Creator: Marriott, Christine A.
Date: 2012-03-26, 2012-05
Description: This research explores the process of assessment within the arena of architectural education by questioning traditional assessment practices...
Show moreThis research explores the process of assessment within the arena of architectural education by questioning traditional assessment practices and probing into the conditions that necessitate change. As architectural educators we have opened our studios to digital technologies for the purposes of design and representation, but how do we measure and judge new approaches to design process now that the tools students are using to solve problems have changed? New tools are available that allow us to examine the design process, but now that there are these new tools, how do we exploit them without completely uprooting our traditional assessment practices? Researchers have learned a great deal about how we learn, but how can this new understanding help to improve the learning that occurs in the architectural design studio? These are the questions that this research has investigated, and with an understanding of the conditions that surround architectural education, a model for assessment has been proposed. That model integrates the technology used for design and representation with the available tools of technology for the purpose of assessment and a growing body of knowledge about the way that we learn. This model is specific to the study of architecture and the teaching and learning of design process.
Ph.D. in Architecture, May 2012
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Title: CUSTODIAL GRANDPARENTING IN YOUNG GRANDMOTHERS: EXPLORING THE STRESS PROCESS MODEL AND FORMS OF ADAPTIVE COPING
Creator: Coleman, Michelle Leoma
Date: 2012-10-17, 2012-12
Description: Custodial grandparents, adults who are caring for their grandchildren on a full-time basis, are becoming more prevalent in the United States....
Show moreCustodial grandparents, adults who are caring for their grandchildren on a full-time basis, are becoming more prevalent in the United States. Although literature examining the occurrence and impact of these families is common in the gerontology field, only recently has this issue been called to attention in young to middle-aged caregivers (early custodial grandparents). Early grandparents, aged 30-45 years, constitute only a small portion of the custodial grandparents; however, they have been suggested to be at the greatest risk for the negative outcomes associated with providing custodial care. Research has indicated, however, that coping strategies may effectively buffer against potential negative outcomes. Little research has been conducted to examine the utilization and benefit of employing specific coping strategies in young custodial grandparents. The current study explored the stress process model and forms of adaptive coping in community sample of 95 young custodial grandmothers (<45 years) raising their grandchildren. The utilization and effectiveness of various forms of coping on caregiving grandparent depression, well-being, and health status were examined. Coping was explored as a potential moderator in a modified stress process model. In addition, the role of subjective social support as a mediator of grandparent stress and subsequent ratings of depression, well-being, and health were evaluated. Results demonstrated that young custodial grandmothers experienced parenting stress levels equivalent to their older counterparts, however, neither stress nor negative appraisals of caregiving led to negative outcomes. Subjective Social Support did not mediate the relationship between stress and caregiver outcomes. Additionally, study results indicated that caregiver appraisals were x not significant mediators of stress and outcomes. Findings provided evidence for the buffering effect of both emotion-focused and problem-focused coping.
PH.D in Psychology, December 2012
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