Roles of GALACTURONOSYLTRANSFERASES in Arabidopsis development

Plant cells are encapsulated by cell walls that provide critical surface protection and cellular structure. Cell walls are dynamically regulated during plant development through the activity of cell wall modifying enzymes. However, how cell wall composition is modulated in roots to influence organogenesis is not well understood. In Arabidopsis, the pectin synthesis enzyme GALACTURONOSYLTRANSFERASE10 (GAUT10) has been shown to be required for both root elongation and cell division in primary roots, leading to a short root phenotype in the absence of GAUT10. GAUT proteins can form complexes and may work in concert with one another to influence cell wall composition. Gene expression mining indicates that GAUT3, GAUT10 and GAUT11 are all enriched in root stem cell populations. Through bimolecular fluorescence complementation (BiFC) assays, it appears that GAUT10 can interact with GAUT3 and GAUT11 in the Golgi apparatus. To test the overlapping function of these GAUT proteins during root development, mutant combinations of these four GAUT genes have been made. Phenotypic analysis of combinatorial gaut seedlings indicate that GAUT3, GAUT10, and GAUT11 have non-redundant and epistatic interactions. Specifically, gaut11-3 roots are longer compared to wild-type (WT) and loss of gaut3 and gaut11 can suppress the short root phenotype of gaut10. These results provide new insight into the shared and unique roles of evolutionarily conserved GAUT family members during Arabidopsis vegetative development

A practical framework for automatic underground utility mapping

Over the years, accidental strikes related to underground utilities have caused significant economic disadvantages, and unfortunately, this problem is still prevalent in today’s practice. Despite ongoing efforts by subsurface utility engineering organizations to mitigate such accidents, annual reports indicate an increasing trend in these incidents. Of the major causes of these accidental strikes is the inaccuracy in locating buried utilities. Thus, addressing this issue is critical. This research thesis focuses on enhancing the reliability and accuracy of utility maps used by excavators through the integration of artificial intelligence and probabilistic methods. By leveraging these advanced techniques, we present a novel, cost-effective, and efficient approach for rapid mapping of utility infrastructure. This method offers a breakthrough in non-intrusive utility mapping, setting a new standard for precision and speed in identifying underground utility

Treatment response to cancer therapies with multimodal imaging technologies

The hallmarks of cancer are now understood to include the altered metabolic and immunogenic properties of cancer and the tumor microenvironment it produces. While this remodeled landscape gives cancer cells the ability to rapidly proliferate while avoiding immune surveillance, but it also provides druggable targets that have revolutionized the treatment approaches to cancer. Despite the benefits of inhibitors of metabolic signaling and immune checkpoint blockage, resistance to these treatments is common, and the use of these therapies requires a personalized approach to medicine. Conventional assays and imaging methods have limitations when it comes to cost, speed, and sensitivity. The need for a methodology that can overcome these limitations has prompted the application of Raman spectroscopy (RS) to monitor cancer. This dissertation consists of multiple works that have addressed treatment response in multiple models and therapeutic modalities, as well as applying the techniques beyond cancer. Treatment of colorectal cancer in vitro has been assessed by metabolic profiling with RS. Treatments studied include platinum-based chemotherapy, anti-EGFR inhibiting antibody, and small molecule inhibitors of EGFR-initiated metabolic signaling pathways. Multivariate analysis methods and mass spectroscopy have been coupled with RS in these studies to better differentiate between treatment groups and validate RS-derived metabolic profiles. Ex vivo studies of cancer patient serum has allowed for differentiation against inflammatory non-cancer phenotypes and understanding of the interplay between metabolism and inflammatory immune response. An ex vivo study of gestational diabetes mellitus patients has allowed for the diagnosis of the condition in the first trimester. An in vivo imaging study using multimodal surface-enhanced Raman spectroscopy (SERS) nanoprobes has also been conducted in this work to track immune cell recruitment in immune checkpoint blockade treatment models. The ongoing study has shown multiplexed imaging for immune cells in the tumor

Innovative strategies to improve the hydration development, dimensional stability, and durability of ultra-high performance concrete

Given the superior mechanical and durability properties of ultra-high performance concrete (UHPC), it has become a material of choice among engineers and researchers. However, UHPC has its own limitations, originating mostly from its high cement content, which can hinder a wide application of UHPC, due to high cost, negative environmental impact, and low dimensional stability. To address these issues, multiple approaches can be taken; One of which is reducing the cement content with supplementary cementitious materials (SCMs) and the other is increasing the degree of hydration (DOH) of cement particles through internal curing. SCMs can be employed to replace a portion of the Portland cement used in the UHPC mixtures. SCMs can be obtained from various origins, ranging from pozzolanic to non-pozzolanic materials, influencing the short- and long-term properties of UHPC. Pozzolanic materials can be broadly divided into artificial and natural pozzolans. Therefore, the abundance of potential SCM alternatives highlights the significance of investigating their effects on UHPC. This is expected to provide an in-depth understanding of their performance, leading to the proper selection of SCMs, depending on application-specific requirements. In order to achieve this goal, three SCMs have been considered in the current study. The SCMs of choice include silica fume, natural zeolite, and limestone, which represent artificial pozzolans, natural pozzolans, and non-pozzolanic SCMs, respectively. In the first stage, the effects of the internal curing capability of natural zeolite on the hydration development of UHPC is investigated. Given that silica fume is the most common SCM currently used in UHPC mix design, it is considered as the base SCM, which is gradually replaced with natural zeolite in 25% increments. Regardless of the binder combination, the cement content is maintained similar among all mixtures. In order to evaluate the hydration development of the mixtures, several macro-scale tests, i.e., free water and temperature measurements, as well as compressive strength, in addition to multiple micro-scale experiments, i.e., scanning electron microscopy (SEM), thermogravimetry analysis (TGA), and X-ray diffractometry (XRD), were carried out. These investigations determined that zeolite particles are capable of internally curing the surrounding unhydrated cement particles through water desorption over time. Furthermore, when used together, silica fume and zeolite particles were found to demonstrate a synergistic effect, which results in a further enhancement of the degree of hydration of the cement particles. As determined in the first stage, natural zeolite particles were able to enhance the hydration degree of cement particles, therefore, the second stage was devised to investigate the impacts of hydration modification on the dimensional stability and durability properties of UHPC mixtures. For this purpose, the autogenous deformation of the mixtures was recorded to document the dimensional stability of the developed UHPC mixtures, along with abrasion, capillary water absorption, and rapid chloride migration test (RCMT), as indicators of their durability properties. It was found that the addition of zeolite particles increases the dimensional stability of the UHPC mixtures. Moreover, although silica fume showed a superiority over zeolite in durability parameters, the mixtures containing equal amounts of silica fume and zeolite outperformed the other mixtures. The third and fourth stages of this holistic investigation is to compare the effect of different SCMs with the control mixture that does not contain any SCMs. In addition to the control mixture, four other mixture were developed, which contained silica fume, silica fume and zeolite, zeolite, and limestone. A similar experimental program to that pursued in the first and second stages was completed on the developed mixtures and their hydration development, dimensional stability, and durability properties were compared. It was observed that, although the control mixture gained the highest compressive strength, the mixtures made with SCMs can demonstrate a better performance in dimensional stability and durability properties. The other approach to increasing the hydration of cement particles in UHPC is internal curing. Internal curing is possible by providing water to cement particles using materials that can store water before or during mixing and return water back to the mixture after hardening. Internal curing can be performed using different types of materials such as porous aggregates, porous cement replacements, and superabsorbent polymers (SAPs). SAPs can be produced in different types and sizes and also can be used in different dosages which results in varying effects on cementitious mixtures. To identify these effects on UHPC, multiple mixtures with two SAP types (i.e., anionic and cationic), two size ranges, and two dosages of SAP are prepared as the fifth and sixth stages of the current investigation. A similar testing matrix to the first and second stages was employed to evaluate the effect of SAP characteristics on hydration kinetics, durability, and dimensional stability of UHPC. For this purpose, a base mixture made with silica fume was considered and SAP type, size, and dosage was used as the varying parameter. It was observed that introduction of SAPs to the UHPC mixture increased the DOH of cement particles and promoted the dimensional stability of the mixtures, however, it had a negative effect on the compressive strength and durability of the mixtures. Finally, it was concluded that once SCMs and SAPs are incorporated in a UHPC mixture, they can alter many of its properties. The findings of this dissertation can be utilized to select the most proper SCMs and SAPs based on each project’s needs

An evaluation of the Student Achievement in Reading program in Iowa

This dissertation explores the role of Adult Education and Literacy (AEL) programs in Iowa’s community colleges, focusing on adult learners with intermediate-level reading skills. It addresses three key areas: the demographic composition of Iowa’s intermediate-reader AEL students, the impact of STAR-certified reading classes on reading proficiency, and the relationship between labor force status and reading achievement. The findings show that Iowa’s AEL population is diverse. Participation in STAR-certified classes had a significant but small positive effect on reading scores. However, no relationship was found between labor force status and reading skills at enrollment. The study underscores the economic importance of adult literacy, linking improved reading skills to employability and community growth. By adopting targeted, responsive teaching methods and refining program design, AEL services can better support adult learners in achieving their educational and career goals. It also calls for further research into factors influencing student retention and engagement. This dissertation highlights AEL programs' potential to address academic and workforce needs, contributing to the success of adult learners and broader state and local economies

Pop star fans’ group travel intention: The role of involvement, group identity, and co-creative behaviors - a case of black pink fans’ perspectives

In the realm of popular culture tourism, this study investigates the group travel intentions of pop star fans, with a focus on the influence of psychological involvement, group identity, and co-creative behaviors. Despite the tendency of fans to travel in groups, limited research has explored the dynamics of their group travel behaviors. To address this gap, the study examines how fans’ psychological and social factors, particularly their level of involvement, group identity, and participation in co-creative behaviors, influence group travel intentions. Grounded in social identity theory, this research proposes a conceptual model and tests hypotheses through a quantitative research approach, the study involved an online survey with 613 Black Pink fans, employing a closed-ended questionnaire with 5-point Likert scales. Using Structural Equation Modeling (SEM) via Mplus, an invariance test and independence sample t-test, was conducted to compare the measurement model's parameters and mean differences between two groups: fans and non-fans. The results demonstrate that psychological involvement has a significant impact on group identity, which in turn fosters co- creative behaviors, specifically participation behaviors and citizenship behaviors. However, only citizenship behavior significantly influences group travel intentions. These findings underscore the pivotal role of citizenship behaviors in shaping fans' group travel intentions and highlight the importance of understanding fans' unique psychological characteristics and behaviors within the context of group travel. Moreover, the study emphasizes the role of fan clubs and influencers in motivating fans’ travel decisions and promoting group travel to pop culture-featured destinations. This study makes a theoretical contribution by suggesting that fans' shared group identity and value co-creation behaviors, particularly citizenship behaviors, may shape their collective travel intentions. This approach contributes to the existing literature by suggesting that group-based interactions may have an important role to play in driving fan tourism behaviors within the context of pop culture tourism. In terms of practical implications, these findings suggest that tourism practitioners may consider enhancing fan experiences by designing group travel packages that focus on emotional and cultural connections, such as collaborative pre-travel planning or themed events. Furthermore, fostering citizenship behaviors among fans, like community involvement activities, could potentially strengthen group identity and deepen their connection to the destination. Keywords: Pop culture tourism, fan psychological involvement, group identity, value co- creation, group travel intention

Theory guided synthesis of commodity chemicals from biomass-derived molecules

Increasing greenhouse gas emissions and decreasing fossil fuel reservoirs provides primary motivation for strategizing alternative pathways to synthesize commodity chemicals. The abundance of biomass and wind energy in the midwestern region of the United States provides good platform to synthesize biomass-derived commodity chemicals through electrochemical route. Transition metals remain benchmark materials for hydrogenation of biomass-derived organic molecules (e.g., cis,cis-muconic acid (ccMA), and furfural) to commodity and specialty chemicals (e.g., adipic acid (AA), trans-3-hexenedioic acid (t3HDA), levulinic acid (LA), and methyl furan). Albeit high selectivity and appreciable conversion for synthesizing commodity chemicals, a relatively low overpotential of hydrogen evolution reaction on transition metals remain a key bottleneck towards achieving appreciable faradaic efficiency. In this dissertation, the density functional theory (DFT)-based calculations combined with experiments are used to understand different mechanisms to synthesize commodity or novel chemicals including AA, LA, t3HDA, and trans-2-hexenedioic acid (t2HDA) under different reaction conditions. The effect of different reaction parameters including pH, cell potential, and subsurface hydrogen on different reaction chemistries are also studied. Overall, the mechanistic insights provided in this work could guide future efforts for designing efficient materials for synthesizing commodity chemicals from biomass-derived molecules

Impact of ultrasonication and high-pressure homogenization on the structure and characteristics of emulsion-templated oleogels stabilized by low-density lipoprotein/pectin complexes

This study focused on developing high-quality oleogels based on pectin (PE) and egg yolk low-density lipoprotein (LDL) using the emulsion-template approach. The properties of PE/LDL-stabilized emulsions structured using ultrasonication (US) and high-pressure homogenization (HPH), and their corresponding oleogels were compared. The particle size, apparent viscosity, microstructure, contact angle, and storage stability of emulsions fabricated by US and HPH were investigated. Additionally, the morphology, rheological and textural properties, and thermal behavior of US- and HPH-based oleogels were analyzed. The results showed that US-fabricated emulsions exhibited smaller particle size (1.88μm), lower viscosity, smaller contact angle (10.4°), and enhanced storage stability compared to HPH-treated emulsions. The US treatment improved interactions between PE and LDL, resulting in more uniform and denser crystalline networks, which effectively entrapped more oil to form stable oleogels. The US-based oleogels at a 1:1 LDL and PE ratio displayed a stronger solid-like structure with higher strength (G′ > 1000 Pa) and reduced oil loss (6.81%) compared to HPH-based oleogels. Furthermore, the US significantly enhanced the textural and thermal properties of oleogels over HPH. These findings highlight the US as a superior technique for constructing PE/LDL-based oleogels with enhanced functional properties, offering a promising method for various food applications.This is a manuscript of an article published as Abou-Elsoud, Mahmoud, Mohamed Salama, Shuze Ren, Haoyang Sun, Xi Huang, Dong Uk Ahn, and Zhaoxia Cai. "Impact of ultrasonication and high-pressure homogenization on the structure and characteristics of emulsion-templated oleogels stabilized by low-density lipoprotein/pectin complexes." Food Hydrocolloids 162 (2025): 110985. doi:10.1016/j.foodhyd.2024.110985

Quantitative proteomics reveals extensive lysine ubiquitination and transcription factor stability states in Arabidopsis

Protein activity, abundance, and stability can be regulated by post-translational modification including ubiquitination. Ubiquitination is conserved among eukaryotes and plays a central role in modulating cellular function; yet, we lack comprehensive catalogs of proteins that are modified by ubiquitin in plants. In this study, we describe an antibody-based approach to enrich ubiquitinated peptides coupled with isobaric labeling to enable quantification of up to 18-multiplexed samples. This approach identified 17,940 ubiquitinated lysine sites arising from 6,453 proteins from Arabidopsis (Arabidopsis thaliana) primary roots, seedlings, and rosette leaves. Gene ontology analysis indicated that ubiquitinated proteins are associated with numerous biological processes including hormone signaling, plant defense, protein homeostasis, and metabolism. We determined ubiquitinated lysine residues that directly regulate the stability of three transcription factors, CRYPTOCHROME-INTERACTING BASIC-HELIX-LOOP-HELIX 1 (CIB1), CIB1 LIKE PROTEIN 2 (CIL2), and SENSITIVE TO PROTON RHIZOTOXICITY1 (STOP1) using in vivo degradation assays. Furthermore, codon mutation of CIB1 to create a K166R conversion to prevent ubiquitination, via CRISPR/Cas9-derived adenosine base editing, led to an early flowering phenotype and increased expression of FLOWERING LOCUS T (FT). These comprehensive site-level ubiquitinome profiles provide a wealth of data for future functional studies related to modulation of biological processes mediated by this post-translational modification in plants.This article is published as Gaoyuan Song, Christian Montes, Damilola Olatunji, Shikha Malik, Chonghui Ji, Natalie M Clark, Yunting Pu, Dior R Kelley, Justin W Walley, Quantitative proteomics reveals extensive lysine ubiquitination and transcription factor stability states in Arabidopsis, The Plant Cell, Volume 37, Issue 1, January 2025, koae310, https://doi.org/10.1093/plcell/koae310

Creep deformation of viscoelastic lumbar tissue and its implications in biomechanical modeling of the lumbar spine

This dissertation expands our knowledge of the “creep” deformation of the viscoelastic lumbar tissues through in vivo human experiments and biomechanical modeling. The specific goals of this dissertation were 1) to examine the effects of trunk flexion angle and stress-recovery (work-rest) schedule on the creep deformation response of viscoelastic lumbar tissues and 2) to explore the impact of creep of viscoelastic lumbar tissues on the biomechanical loading of the lumbar spine. Three preliminary studies were conducted to lay the foundation of this dissertation and two main studies (an empirical study and a modeling study) were conducted to achieve these goals. Preliminary Study I explored the effect of a 12-minute submaximal trunk flexion on lumbar spinal creep. The subject-specific angle was set to be ten degrees less than the trunk flexion angle inducing flexion-relaxation of lumbar extensor muscles. The trunk flexion-extension motions were performed every three minutes to capture the peak lumbar flexion angle and lumbar flexion angle (EMG-off angle) at which flexion-relaxation of lumbar extensors occurred. Results revealed that the 12 minutes of these postures led to significant increases in peak lumbar flexion angle (1.3°) and EMG-off angle (2.9°), denoting the lumbar spinal creep. The results suggest that passive tissue deformation should be considered in submaximal trunk flexion, where the extensor muscles are significantly involved in resisting the external moment. Preliminary Study II examined cumulative creep deformation of viscoelastic lumbar tissues as a function of work-rest schedule: a) three minutes of maximal trunk flexion followed by twelve minutes of upright standing (3:12)—sequence repeated three times, and b) one minute of maximal trunk flexion followed by four minutes of upright standing (1:4)—sequence repeated nine times. The lumbar flexion angle was continuously captured to quantify lumbar spinal creep during maximal trunk flexion. Results revealed that the change in lumbar flexion angle was significantly greater in the Long (3:12) condition (Δ3.5°) than in the Short (1:3) condition (Δ1.6°). The results demonstrated that the cumulative creep deformation of the lumbar spine can vary with work-rest schedules even when total work and rest times are constant, supporting multidimensional physiological responses of creep in the viscoelastic tissues of the lumbar spine. Preliminary Study III quantified the time-dependent changes in individual tissue forces/moments at the L4/L5 level during sustained submaximal trunk flexion. A muscle fatigue-modified EMG-assisted biomechanical model with passive tissue components was employed. The kinematic and EMG data collected in Preliminary Study I were used as input variables. Results revealed that sustained trunk postures resulted in a time-dependent increase in the proportion of passive lumbar tissues in resisting the external moment (54.9% to 65.7%)—ultimately leading to increases in the compression force (1480.8 N to 1720.8 N) and anterior-posterior shear force (770.0 N to 889.4 N). These indicate that the passive tissues with shorter moment arms should bear greater amounts of the net internal extensor moment as lumbar flexion gradually increases at the constant external moment. The results demonstrated that the time-dependent approach to EMG-assisted modeling with passive tissue components can improve the accuracy in the estimation of spinal loading by considering the transfers of load from active to passive tissues. This study also suggests that creep should be considered to more accurately estimate spinal loading as a function of time. Main Study I aimed to explore the interaction between trunk flexion posture and work-rest schedule on lumbar spinal creep. On four different days sixteen participants performed a 30-minute protocol that consisted of 12 minutes of trunk flexion and 18 minutes of upright standing. Two trunk flexion postures (Max [maximum lumbar flexion], SubMax [ten degrees less than flexion-relaxation]) and two work-rest schedules (Long (3:6), Short (1:2)) were considered. Trunk flexion-extension motions were performed before and after the 30-minute protocol to capture the changes in peak lumbar flexion angles and changes in EMG-off angles for L3 and L4 paraspinals. Results revealed that ΔL3 EMG-off angle was significantly smaller in the SubMax/Long condition (0.1°) compared to the other conditions (1.8° on average), denoting a significant interaction effect. The Δpeak lumbar flexion angle and ΔL4 EMG-off angle were greater in the Short (1:2) (1.8°) than in the Long (3:6) condition (1.0°), which is contrary to the results of the Preliminary Study II. The major difference between the two studies is the work-rest ratio (1:2 for this dissertation and 1:4 for the Preliminary Study II). These results suggest that a potential interaction between work-rest schedule and work-rest ratio should be explored to find the optimal work-rest strategy to minimize the cumulative creep response of viscoelastic lumbar tissue. Further analysis of lumbar flexibility showed significant interactions between flexibility and trunk flexion posture (p < 0.05 for EMG-off angles) and flexibility and work-rest schedule (p < 0.05 for all measures) on the cumulative lumbar spinal creep. The low flexible group had significantly greater ΔL3 EMG-off and ΔL4 EMG-off in the Max posture (2.1° on average) than in the SubMax posture (0.8°), while the high flexible group was not affected by postures. In addition, the low flexible group was not affected by work-rest schedules, while the high flexible group experienced greater creep responses in the Short (1:2) condition (2.5° on average) than in the Long (3:6) condition (0.6°). These results indicate that lumbar flexibility can play a significant role in lumbar spinal creep. Collectively, the results of this study suggest that the cumulative creep response of the viscoelastic tissues of the lumbar spine can be affected by trunk flexion angle, work-rest schedule, work-rest ratio, and lumbar flexibility. Main Study II explored the impact of creep on the quality of internal moment predictions from a biomechanical model of the lumbar spine during sagittally symmetric exertions. Comparison of two different biomechanical models was of primary interest: a) EMG-assisted model with passive tissue components (No-Creep) and b) EMG-assisted model with stiffness-modified passive tissue components (Creep). The Creep model modified the stiffness of each ligament as a function of creep through in vitro data. The kinematic/EMG data, collected during a single trunk flexion motion immediately after 30-minute work-rest schedules under Max conditions in Main Study I, were used as input variables in the biomechanical models. Results revealed a significant difference in mean absolute error between Creep and No-Creep models beyond trunk flexion angle eliciting flexion-relaxation of erector spinae muscles (21.8 Nm vs. 40.3 Nm). Further analysis of spinal loads of an L4/L5 disc at full trunk flexion showed that the Creep model led to 784.7 N (31.7%) and 280.6 N (21.6%) reductions of compression and shear forces of the L4/L5 disc than the No-Creep model. These results indicate that the modulation of the loss of force-producing capability of passive tissues under creep conditions led to more accurate prediction of net internal moment and spinal loads at near full flexion postures. In conclusion, the creep deformation of viscoelastic lumbar tissues as a function of trunk flexion angle and stress-recovery schedule and its implications in lumbar biomechanical modeling were explored. The results of the empirical studies suggest that the cumulative creep response of the viscoelastic lumbar tissues can be influenced by trunk flexion angle, work-rest schedule, work-rest ratio, and lumbar flexibility, supporting a multidimensional physiological response to creep. The results of the modeling studies suggest the importance of a time-dependent approach to consider load transfer between lumbar tissues and an in vitro data-driven approach to modify passive stiffness in a lumbar biomechanical modeling technique to provide more precision prediction of the internal extensor moment and spinal loading