Digital Commons Network^™

Elevated Temperature And Browning Increase Dietary Methylmercury, But Decrease Essential Fatty Acids At The Base Of Lake Food Webs, Pianpian Wu, Martin J. Kainz, Fernando Valdés, Siwen Zheng, Katharina Winter, Rui Wang, Brian Branfireun, Celia Y. Chen, Kevin Bishop

Dartmouth Scholarship

Climate change scenarios predict increases in temperature and organic matter supply from land to water, which affect trophic transfer of nutrients and contaminants in aquatic food webs. How essential nutrients, such as polyunsaturated fatty acids (PUFA), and potentially toxic contaminants, such as methylmercury (MeHg), at the base of aquatic food webs will be affected under climate change scenarios, remains unclear. The objective of this outdoor mesocosm study was to examine how increased water temperature and terrestrially-derived dissolved organic matter supply (tDOM; i.e., lake browning), and the interaction of both, will influence MeHg and PUFA in organisms at the base of …

Quantifying Planarian Behavior As An Introduction To Object Tracking And Signal Processing, Nicole C. Stowell, T. Goel, Vir Shetty , '22, Jocelyne Noveral, Eva-Maria S. Collins

Biology Faculty Works

Answers to mechanistic questions about biological phenomena require fluency in a variety of molecular biology techniques and physical concepts. Here, we present an interdisciplinary approach to introducing undergraduate students to an important problem in the areas of animal behavior and neuroscience—the neuronal control of animal behavior. In this lab module, students explore planarian behavior by quantitative image and data analysis with freely available software and low-cost resources. Planarians are ∼1–2-cm-long aquatic free-living flatworms famous for their regeneration abilities. They are inexpensive and easy to maintain, handle, and perturb, and their fairly large size allows for image acquisition with a webcam, …

Effects Of Nitrogen Management And Cultivar On Strawberry Production Under Disease Pressure, Kamille A. Garcia-Brucher

Master's Theses

Effects of nitrogen management and cultivar on strawberry production under disease pressure

Kamille Garcia-Brucher

California strawberry growers face increasing regulatory pressures to manage nitrogen (N) applications in their production system. Standard practice in the California strawberry industry is to apply a synthetic pre-plant controlled release fertilizer (CRF) to ensure the crop has sufficient N during winter establishment. Some research from the UC Cooperative Extension suggests this practice is not efficient at delivering N to the crop since most of the N is released from CRF before strawberry crop N uptake is significant. Another concern for California strawberry growers is loss …

Practical Wisdom As An Adaptive Algorithm For Leadership: Integrating Eastern And Western Perspectives To Navigate Complexity And Uncertainty, Mai P. Trinh, Elizabeth A. Castillo

Management Faculty Publications

In this paper, we integrate Eastern and Western perspectives of practical wisdom to answer the question, how can practical wisdom transfer across cultural boundaries in a world of increasing interconnection? We describe key properties of practical wisdom in early Western and Eastern schools of thoughts and explain how the concept of practical wisdom in ancient philosophy aligns with modern-day complex system science. We identify seven qualities of complex adaptive systems as a universal pattern that underlies both Eastern and Western perspectives. From these qualities, we develop an integrated conceptual framework of practical wisdom as factors both internal and external to …

Developing Design And Analysis Framework For Hybrid Mechanical-Digital Control Of Soft Robots: From Mechanics-Based Motion Sequencing To Physical Reservoir Computing, Priyanka B. Bhovad

All Dissertations

The recent advances in the field of soft robotics have made autonomous soft robots working in unstructured dynamic environments a close reality. These soft robots can potentially collaborate with humans without causing any harm, they can handle fragile objects safely, perform delicate surgeries inside body, etc. In our research we focus on origami based compliant mechanisms, that can be used as soft robotic skeleton. Origami mechanisms are inherently compliant, lightweight, compact, and possess unique mechanical properties such as– multi-stability, nonlinear dynamics, etc. Researchers have shown that multi-stable mechanisms have applications in motion-sequencing applications. Additionally, the nonlinear dynamic properties of origami …

A Critical Analysis Of The Discourse Of Culturally Responsive Curriculum Within South Carolina’S Secondary U.S. History And Constitution Standards, James L. Goude

All Dissertations

This research study explored the presence of implicit racial bias in South Carolina curriculum policy within its content standards for U.S. history and the Constitution. Curriculum policy discourse flows through the statewide public school system from the legislature, through district offices, and into classrooms. That discourse guides classroom teachers on what the state legislated as essential knowledge of U.S. history. Teachers make instructional choices based on state and district guidance documents that may affect the performance of Black students on South Carolina’s U.S. History and Constitution End-of-Course Exam (USHC-EOC). This study describes the educational policy discourse from macro-documents, meso- documents …

The Causal Effects Of Growing Up In A Two-Parent Household: Evidence From The Psid On Schooling, Earnings, And Labor Force Participation, Bob Shihao Wen

All Dissertations

The children who grew up in a two-parent household earn more than the other children reared in non-intact parental families. The causal effects of growing up in a two-parent household can be identified using two specification strategies. First, I include the parental household income and educational attainment in the model, along with the child’s demographic characteristics (age, gender, race, and state of residence), to disentangle the childhood family structure effect from the other parental influence. Second, I use the average state divorce rate over the child’s first 16 years of childhood and the childhood years of exposure to the no-fault …

Impact Of Interventions On Student Performance Among Eighth Graders In Algebra 1, Tiffany Osborne

All Dissertations

Educational leaders and practitioners face challenges in South Carolina schools, but through improvement science processes (Bryk, Gomez, Grunow, & LeMahieu, 2015), they can collectively develop solutions which directly address those issues. In this Participatory Action Research (PAR) study, I partnered with participants in ongoing Plan-Do-Study-Act (PDSA) cycles (Bryk, et al., 2015) to improve student outcomes. I triangulated multiple data points and corroborated findings with students’ own perceptions to provide evidence that students can achieve in eighth grade Algebra 1 when given the opportunity to enroll in the course and when afforded appropriate ongoing academic interventions that foster conceptual understanding, self-efficacy, …

Influencing The Inflammatory Response Through Multi-Scale Geometry, Antibiotic Release, And Fluid Management In A Textile-Based Biomaterial Wound Dressing, Elizabeth Gianino

All Dissertations

The total population of diagnosed and undiagnosed diabetes mellitus in the United states is expected to rise by 54% between the years of 2015 and 2030 contributing to $200 billion in health care expense. The exponential rise in common diabetic wounds, such as diabetic foot ulcers, puts a large population at risk for complications such as infection, amputation, and even death. Peripheral neuropathy leading to late diagnoses, patient non-compliance, and lack of holistic treatment options all contribute to complications with the incidence of new ulcer formation after treatment reaching 50%. This work explores the design, development, and in vitro evaluation …

Towards Understanding Protein Immobilization Rules Through Site-Specific Covalent Immobilization Of T4 Lysozyme, Maxwell Hilbert

All Dissertations

Soluble enzymes have the unique ability to assist the conversion of complex substrates in fewer steps compared to conventional chemical synthesis; however, when immobilized to a surface, the insoluble enzyme's activity and stability can suffer in its new environment. To improve upon future immobilized enzyme efficacy, a fundamental understanding of the interactions across the enzyme, linker, and surface during covalent, site-specific immobilization that can be detrimental to its activity is required. More specifically, using a well-characterized and model enzyme, T4 lysozyme (T4L), 28 different cysteine attachment points' effects on site-specifically immobilized activity are examined. Different combinations of heterobifunctional amine-to-sulfhydryl crosslinkers …

Time-Lapse Observation Of Sarcomeric Addition In Hypertrophic Models Based On A Tissue Like Cardiomyocyte Culture, Ailin Wei

All Dissertations

Cardiac hypertrophy is the response of the heart to increased mechanical stress exerted on the heart. In a hypertrophic heart, the muscles elongate or/and thicken with cardiomyocytes growing sizes. It is assumed that cardiomyocytes elongate by adding sarcomeres in series; the cardiomyocytes thicken with the addition of sarcomeres in the parallel position.

In this study, a tissue-like culture model was achieved with step-like ICDs. Uniaxial static stretch has been applied to our unique culture model for studying mechanical-load-induced cardiac hypertrophy. Hypertrophic responses of these cardiomyocytes have been confirmed on transcriptional and translational levels in our tissue-like model. The two-photon excitation …

Ecological Outcomes Of Movement Behavior In Brown Pelicans From The South Atlantic Bight, Bradley Wilkinson

All Dissertations

Vagile organisms are expected to display movement behaviors that respond to a wide variety of both intrinsic and extrinsic factors. Identifying drivers of movement is fundamental to understanding the ecology of species, as well as implementing effective conservation measures. Technological advancements have allowed for the collection of fine-scale positional data at rapid temporal scales, which can be a powerful tool for assessing the movement behavior of tracked species and for understanding the potential fitness implications resulting from variations in animal space use. The goal of this dissertation was to identify important drivers of movement behavior and to describe the ecological …

Understanding And Modulating Amyloid Aggregation, Yanting Xing

All Dissertations

Amyloids are the products of protein misfolding into fibril-like structures, which take place in human tissues and organs, including the human brain, heart, liver, and pancreas. As the deposition of amyloid fibrils usually leads to the dysfunction or death of cells, the formation of amyloid is associated with more than 20 human diseases, such as Alzheimer’s, Parkinson’s, and type 2 diabetes. Understanding how soluble peptides to form amyloid fibrils and how to modulate those amyloid aggregation are central to the design of rational therapeutic strategies against those diseases. Increasing experiments suggest that amyloid peptides can undergo liquid-liquid phase separation (LLPS) …

Exploring The Role Of Ampk In Nutrient Sensing And Signaling In The Human Parasite Trypanosoma Brucei, Jessica Jones

All Dissertations

African trypanosomes are protozoan parasites that cause the diseases African sleeping sickness and nagana, in humans and cattle respectively. These parasites have complex life cycles with infection of a mammalian host, ~5mM glucose, following transmission by an insect vector, essentially zero glucose. With these pathogens being exposed to rapidly changing glucose abundance in a host-dependent manner, the ability to sense and rapidly respond to changes in the availability of the hexose are critical. First, I provide a review of glucose metabolism in Trypanosoma brucei. Then, we explore the role of the catalytic α subunit of AMPK, a eukaryotic master …

Capillary Driven Transport In Soft Solids, Saiful Islam Tamim

All Dissertations

Soft solids, such as polymeric gels, are elastic materials that can be significantly deformed by capillary forces which act at the interface. The coupling between elasticity and capillarity is known as elastocapillarity and is useful to wide ranging applications, from drop pinchoff of bioinks for 3-D printing tissue scaffolds, to generating droplet patterns on microfluidic devices. In this dissertation, we develop mathematical models of elastocapillary driven motions in soft solids. The focus is on understanding the relevant physics in such complex phenomena, while also recovering the limiting cases of classical fluid mechanics and solid mechanics theories.

This dissertation investigates two …

Identification Of Biomarker Systems Of Autism Spectrum Disorder And Uterine Cancer, Allison Hickman

All Dissertations

Complex diseases and disorders pose a challenge to scientists due to their variable and often inconsistent genetic and environmental underpinnings across affected individuals. Because of this variability, large condition-specific datasets and corresponding analytical tools and approaches are being curated as resources to investigate potential genetic trends in complex diseases and disorders. In this Dissertation, I used DNA- and RNA-based resources to discover polygenic biosignatures associated with Autism Spectrum Disorder (ASD) or uterine cancer. To explore the intersection of small-effect common DNA variants and regulation in ASD, I discovered and analyzed trends in allelic associations at eQTLs within ASD-affected individuals. Association …

Development Of Solution Blow Spun Nanofibers As Electrical And Whole Cell Biosensing Interfaces, Craig Levar Miller

All Dissertations

Infectious pathogens place a huge burden on the US economy with more than $120 billion spent annually for direct and indirect costs for the treatment of infectious diseases. Rapid detection schemes continue to evolve in order to meet the demand of early diagnosis. In chronic wound infections, bacterial load is capable of impeding the healing process. Additionally, bacterial virulence production works coherently with bacterial load to produce toxins and molecules that prolongs the healing cycle. This work examines the use of nonwoven polymeric conductive and non-conductive nanofiber mats as synthetic biosensor scaffolds, drug delivery and biosensor interface constructs. A custom-made …

Interventions To Increase Prospective Teacher Candidates' Praxis Ii Content Exam Scores, Takara Hart

All Dissertations

Teacher shortages are a pervasive issue in South Carolina’s public schools. Some prospective teacher candidates have shown obstacles in meeting the minimum required Praxis II Content exam score. The purpose of this qualitative phenomenological study was to explore and develop specific Praxis II Content exam interventions to improve scores for six prospective teacher candidates in South Carolina. All participants were trying to meet the licensure exam requirement for various alternative certification programs. Malcolm Knowles’ Andragogy Adult Learning Theory guided the study as a theoretical framework, and Lev Vygotsky’s Socio-Cultural Constructivism provided the conceptual frame. Descriptive coding and analysis, using Dedoose …

Enabling Dna-Informed Breeding For Disease Resistance In Peach, Wanfang Fu

All Dissertations

DNA-informed breeding is becoming conventional for Rosaceae crops. The advancement of genomic tools and their application in breeding has potential to accelerate the breeding cycle and increase breeding efficiency. The objective of this dissertation was to explore the application of whole genome markers to identify marker-trait associations and potential candidate genes associated with peach disease resistance traits and evaluate the feasibility of applying genomic prediction models in breeding for disease resistance in peach. Two economically important diseases, brown rot and bacterial spot, were explored.

Genome wide association studies (GWAS) were first applied in detecting regions in the peach genome associated …

El Leñador, December 2021, El Leñador Staff

El Leñador Newspaper

El Leñador is an English and Spanish newspaper produced by Humboldt State University students. Our staff cover and provide news to Latinx and other diverse communities on campus and in Humboldt County. We are committed to providing relevant news and expanding the representations and stories told about people of color and other marginalized groups. Our work helps create more social, political and cultural diversity in local media.

El Leñador es un periodico en español y inglés producido por estudiantes de la Universidad Estatal de Humboldt. Nuestro personal cubre y provee noticias a la comunidad Latinx y otras comunidades diversas en …

Contrast-Enhanced Ultrasound Of Muscle Perfusion May Indicate Patient Response To Left Ventricular Assist Device Therapy., Lauren J. Delaney, Kathleen Fitzgerald, Maria Stanczak, Priscilla Machado, John W..C. Entwistle, Flemming Forsberg, Gordon R. Reeves

Department of Radiology Faculty Papers

PURPOSE: Left ventricular assist device (LVAD) support is associated with peripheral vascular abnormalities beyond those associated with heart failure (HF). These abnormalities are associated with persistent functional impairments that adversely impact quality of life (QoL). Methods for measuring peripheral vascular function in this population are needed.

METHODS: This pilot study investigated the use of contrast-enhanced ultrasound (CEUS) using standardized protocols to estimate changes in peripheral (quadriceps) muscle perfusion among patients with HF (INTERMACS profile 3) undergoing LVAD implantation (n = 7). Patients were then stratified by those who did ("responders", n = 4) and did not ("nonresponders", n = 3) …

Effects Of Localized Oxygen Production By Electrolysis On The First-Generation Glucose Sensor Response, Nandita Halder

Graduate Theses and Dissertations

Glucose sensors are very important for detecting blood glucose both in vitro and in vivo. First-generation glucose biosensors were based on the glucose oxidase (GOx) enzyme using molecular oxygen as the electron acceptor and therefore oxygen dependent. Unfortunately for in-vivo work, oxygen in the body is variable and limited. Alternative approaches to overcome the oxygen dependency came with their own limitations. The widely used and commercially available ex-vivo glucose test strip uses a mediator in place of oxygen to free it from oxygen dependency. The mediator-based technology, in most cases cannot be transferred to in vivo applications due to the …

Substance Use And Psychological Distress Correlates Of Sleep Quality Among College Students, Juanybeth Morales Ortega

Graduate Theses and Dissertations

Poor sleep quality in college students is a major problem associated with adverse health outcomes, cognitive performance, substance use, and psychological distress. Our study explored how substance use and psychological distress are associated with the sleep quality of college students. We analyzed secondary data collected in 2019 using a cross-sectional survey design. Measures included participants’ demographic characteristics, sleep quality using the Pittsburg Sleep Quality Index (PSQI), drug use, depression using the Patient Health Questionnaire-9 (PHQ-9), and suicidality. After excluding participants with missing information for sleep quality, a total of 555 students remained for the analysis. Our bivariate analysis found that …

Comparing Organic And Conventional Yield Responses To Climate Variations, Joost Wilken Meyer

Graduate Theses and Dissertations

This thesis compares the responses of organic yields and conventional yields towards climate variations. To achieve this objective, weather variables such as growing season weather conditions (average temperature, precipitation, cloud cover, relative humidity, drought index), weather anomalies, the occurrence of severe or extreme droughts and excessive rainfalls, are combined with 23 data sets gathered from previous studies that compare organic and conventional yields from the same location and time periods. To narrow the scope, the thesis focuses on soybean, maize, and wheat production in Europe and North America. Study-level fixed-effects models are used to control for any time-invariant factors such …

Multifunctional Programmable Self-Assembled Nanoparticles In Nanomedicine, Yoshie Sakamaki

Graduate Theses and Dissertations

Developing methodologies to control the architecture of nanoparticles (NPs) at the atomic level prevents their inhomogeneity and leads to a variety of expected functions. Rationally designed nanoparticles can either be programmed or crystallized structures into pre-determined structures achieving tunable particle pore size and physiochemistry. In this dissertation, two broad classes of multifunctional nanoparticles are developed, metal-organic frameworks and DNA-NP aggregates.

Metal-organic frameworks are a novel class of highly porous crystalline materials built from organic linkers and metal cluster-based secondary building units. However, applications in bioremediation have not been developed very well especially in applications regarding drug delivery systems (DDS). The …

Crispr Gene Editing Drivers, Barriers And Prospects: A Comparative Study Among Plant Scientists Globally, Adriaan Johannes De Lange

Graduate Theses and Dissertations

The introduction of CRISPR gene editing into food crops has potential to contribute to food security and sustainable food production globally. To date, most scientific studies have focused on consumer perception of CRISPR gene edited foods or the potential benefits and risks of the CRISPR technology and none have focused on the perceptions of plant scientists concerning CRISPR gene editing. This study aimed to explore the investments, functions, barriers, benefits for specific crops and beneficiaries of CRISPR gene editing according to plant scientists, by distributing an online survey in which 1,040 plant scientists active across six continents and in both …

Does Self-Reference In Concept Mapping Influence Transfer?, Daniel A. Parker

Graduate Theses and Dissertations

Concept maps are a popular learning activity that have successfully demonstrated student learning outcomes. Research suggests that concept mapping has a positive effect on recognition, recall, and transfer. Likewise, researchers in cognitive psychology have shown the value of referencing oneself with a concept. Known as the self-reference effect, learners who connect their experiences or traits with new knowledge are more likely to remember that knowledge than if they used other mnemonic devices. Previous research suggests that integrating self-reference in concept mapping may improve recall. However, to date, no study has investigated the influence of this combination on higher order learning …

Investigation Of Iron-Nickel Films Based Catalysts: Controlling Hydrogen Evolution Reaction (Her) Through An Electrode-Electrolyte Engineering Approach, Sergio Ivan Perez Bakovic

Graduate Theses and Dissertations

Electrochemical energy conversion technologies need to be economically viable in order to be adopted. Earth-abundant transition metals (i.e., Fe, Co, and Ni) have attracted attention due to their high availability, low cost, and catalytic characteristics that are in many cases found in and exploited by nature. Herein, we synthesize FexNi100-xOy electrocatalyst films and study how the electrocatalyst-electrolyte interactions alter the hydrogen evolution reaction (HER).In this work, FexNi100-xOy films were synthesized to study the composition, chemical state, and morphology. Characterization results provided a well-established electrocatalyst film platform to then proceed with electrochemical evaluations. The effects of the electrode composition and electrochemically …

Catalytic Activity Of Molybdenum-Dioxo Complexes, Randy Tran

Graduate Theses and Dissertations

This dissertation details the development of rationally designed dioxomolybdenum catalyst active for deoxydehydration (DODH), the net reduction of diols and polyols into alkenes and dienes. Catalyst design involved variations on dioxomolybdenum(VI) supported by a dianionic meridional pincer ligand. Rational substrate scope was explored using aliphatic diols, aromatic diols, and biomass derived diols. Various reductants were tested for ability to catalyze the reaction. The substrate specific mechanism of DODH was explored utilizing NMR and in-situ infrared spectroscopy and important rate constants and rate determining steps were found to aid in the optimization of ideal reaction conditions. Catalytic activity was observed to …

Parenting The Gifted: Caregivers’ Perspectives Of Challenges And Their Confidence To Support Their Exceptional Children, Kristi A. Mascher

Graduate Theses and Dissertations

This phenomenological study uses Bandura’s theory of self-efficacy (1977) to examine the lived experiences of eight parents of gifted children and how their experiences, both positive and negative, shape their perception of their confidence and may contribute to building future supports for gifted parents and caregivers. Qualitative data, collected through semi-structured interviews and analyzed with an interpretive/hermeneutic lens, provides seven major themes derived from the voices of parents with children of varying ages and exceptionalities. In addition, this study concludes with a discussion surrounding the additional challenges associated with parenting the exceptional, frameworks for gifted parent support systems, as well …