Engineering Commons^™

Synthesis Of Thiol-Acrylate Hydrogels For 3d Cell Culture And Microfluidic Applications, Anowar Hossain Khan

LSU Doctoral Dissertations

Globally cell culture is an $18.98 billion industry as of 2020, with an 11.6 percent annual growth rate. Drug discovery has an estimated worth of $69.8 billion in 2020 and is predicted to grow to $110.4 billion by 2025. Three-dimensional (3D) cell culture of cancer cells is one of the rapidly growing felids since it better recapitulates in vivo conditions compared to two-dimensional (2D) models. However, it is challenging to grow 3D tumor spheroids outside the body, and some of the existing technology can generate these spheroids outside the human body but poorly mimic in vivo tumor models. Therefore, there …

The Age-Dependent Characterization Of The Er-Alpha Positive Breast Cancer Tumor Microenvironment, Katie Marie Hamel

LSU Doctoral Dissertations

In disease states such as cancer, endocrine and paracrine signals from adipose tissue contribute to cancer progression and drug resistance. Young individuals diagnosed with estrogen receptor-alpha positive (ER-a+) breast cancer have an observed increase in resistance to endocrine therapies. This suggests that an alternative estrogen signaling pathway is active within these tumors. Despite this, the effects of stromal age on the endocrine response in breast cancer is not well known. Here, we review and highlight the involvement of the stromal age in both tumorigenesis and physiological wound healing. To identify specific differences between young and aged ER-a+ breast tumors, RNA …

Zein And Lignin-Based Nanoparticles As Delivery Systems: Pesticide Release And Nanoparticle Health Impact On Soybean Plants, Fallon Polette Salinas Gonzalez

LSU Doctoral Dissertations

This research examined the effect of biodegradable, polymeric, lignin-based nanoparticles (LNPs, 113.8±3.4, negatively charged) and zein nanoparticles (ZNP, 141.6±3.9, positively charged) on soybean plant health. The LNPs were synthesized from lignin, covalently linked to poly(lactic-co-glycolic) acid by emulsion evaporation. ZNPs were synthesized by nanoprecipitation. Soybeans grown hydroponically were treated with three concentrations (0.02, 0.2, and 2 mg/ml) of NPs at 28 days after germination. The effect of ZNPs and LNPs on plant health was determined through analysis of root and stem length, chlorophyll concentration, dry biomass of roots and stem, as well as carbon, nitrogen, and micronutrient absorption after 1, …

Neuromotor Control Of The Hand During Smartphone Manipulation, Prasanna Kumar Acharya

LSU Doctoral Dissertations

The primary focus of this dissertation was to understand the motor control strategy used by our neuromuscular system for the multi-layered motor tasks involved during smartphone manipulation. To understand this control strategy, we recorded the kinematics and multi-muscle activation pattern of the right limb during smartphone manipulation, including grasping with/out tapping, movement conditions (MCOND), and arm heights.

In the first study (chapter 2), we examined the neuromuscular control strategy of the upper limb during grasping with/out tapping executed with a smartphone by evaluating muscle-activation patterns of the upper limb during different movement conditions (MCOND). There was a change in muscle …

Metabolic Network Analysis Of Filamentous Cyanobacteria, Daniel Alexis Norena-Caro

LSU Doctoral Dissertations

Cyanobacteria were the first organisms to use oxygenic photosynthesis, converting CO₂ into useful organic chemicals. However, the chemical industry has historically relied on fossil raw materials to produce organic precursors, which has contributed to global warming. Thus, cyanobacteria have emerged as sustainable stakeholders for biotechnological production. The filamentous cyanobacterium Anabaena sp. UTEX 2576 can metabolize multiple sources of Nitrogen and was studied as a platform for biotechnological production of high-value chemicals (i.e., pigments, antioxidants, vitamins and secondary metabolites). From a Chemical engineering perspective, the biomass generation in this organism was thoroughly studied by interpreting the cell as a microbial …

Physical And Biological Factors Controlling The Fate Of Nitrate In A Louisiana Coastal Deltaic Floodplain, Alexandra Christensen

LSU Doctoral Dissertations

The Mississippi River Delta is threatened by a growing pressure to support large human populations in the United States both with food production, navigation systems, and urban development in the Mississippi River Basin. Nitrate-nitrogen load in the Mississippi River, up to 100 Tg N yr^-1 from agricultural and urban runoff, leads to phytoplankton blooms and hypoxia across the Louisiana continental shelf, creating dead zones of low dissolved oxygen threatening a significant commercial fishery. Along the coast and river corridors, floodplain ecosystems have the capacity to retain and remove nitrate. This dissertation explores the role of productive, actively growing coastal …

Direct Quantification Of Deubiquitinating Enzyme Activity In Single Intact Cells, Nora Safabakhsh

LSU Doctoral Dissertations

Challenges in drug efficacy occur during the treatment of most types of cancer due to the heterogeneity of the tumor microenvironment. This has led to the development of personalized medicine. Due to the clinical success of the proteasome inhibitors Bortezomib and Carfilzomib in treatment of multiple myeloma, interest has shifted towards molecularly-targeted chemotherapeutics for ubiquitin-proteasome system (UPS). Deubiquitinating enzymes (DUBs) are an essential part of this pathway which have been found to promote Bortezomib resistance in multiple myeloma patients. Unfortunately, there is a lack of specific, high throughput biochemical assays to characterize DUB activity in patient samples before and after …

A Study Of Scalability And Cost-Effectiveness Of Large-Scale Scientific Applications Over Heterogeneous Computing Environment, Arghya K. Das

LSU Doctoral Dissertations

Recent advances in large-scale experimental facilities ushered in an era of data-driven science. These large-scale data increase the opportunity to answer many fundamental questions in basic science. However, these data pose new challenges to the scientific community in terms of their optimal processing and transfer. Consequently, scientists are in dire need of robust high performance computing (HPC) solutions that can scale with terabytes of data.

In this thesis, I address the challenges in three major aspects of scientific big data processing as follows: 1) Developing scalable software and algorithms for data- and compute-intensive scientific applications. 2) Proposing new cluster architectures …

The Tensile Root Strength Of Emergent Coastal Macrophytes, Lauris Olivia Hollis

LSU Doctoral Dissertations

Spartina patens is a dominant emergent macrophyte in fresh, intermediate, and brackish marshes along the Atlantic and Gulf coasts of United States where its biomechanical properties are a key component of wetland health and resilience. Its root biomass and tensile root strength are essential for anchorage, erosion protection, and are important determinants of soil strength. Nutrients and the herbicide atrazine are suspected of negatively impacting this wetland plant and others. The objectives of this study were to: 1) ascertain the tensile root strength of five emergent coastal macrophytes in coastal estuaries, and 2) test the effects of nutrient addition, atrazine …

Rice Hull Bioreactor For Recirculating Aquaculture, Marlon A. Greensword

LSU Doctoral Dissertations

The engineering of floating media biofilters has been optimized over the years. The backwashing process has made them more energy and water efficient. Likewise, moving bed bioreactors (MBBR) are gaining interest and popularity because they are relatively affordable to build. Yet, developing countries’ aquaculture production remains largely excluded from the advances made in recirculating aquaculture systems (RAS). This discrepancy is partially driven by the high costs of media such plastic beads and Kaldnes (KMT) media, commonly used in MBBR.

This dissertation evaluates the usability and profitability of rice hulls (RH), an abundant by-product in many developing nations, as a sinking …