Predictors of Attention-Deficit/Hyperactivity Disorder Symptom Trajectories During Late Childhood and Early Adolescence Using the Adolescent Brain Cognitive Development (ABCD) Dataset

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Description
Attention-Deficit/Hyperactivity Disorder (ADHD) impacts 7% of children and is associated with serious impairment throughout the lifespan. Though considered a chronic, stable condition, symptoms fluctuate substantially during adolescence, and symptom trajectory is linked to adult outcomes. A small number of studies

Attention-Deficit/Hyperactivity Disorder (ADHD) impacts 7% of children and is associated with serious impairment throughout the lifespan. Though considered a chronic, stable condition, symptoms fluctuate substantially during adolescence, and symptom trajectory is linked to adult outcomes. A small number of studies have examined symptom trajectory during adolescence, but these have predominately examined demographic predictors. As a neurodevelopmental disorder, ADHD is theorized to arise from deficits in executive functions (EFs). Extant literature identifies three major components of EF- working memory, behavioral inhibition, and set shifting- as interrelated constructs underlying ADHD symptom expression. This study aimed to 1.) identify trajectories of ADHD symptoms, 2.) examine demographic predictors of trajectories, and 3.) examine whether EF predicts symptom trajectory using five timepoints from the Adolescent Brain Cognitive Development study, a large-scale, representative, population-based sample from the United States. 1,605 participants meeting criteria for ADHD included in analyses. ADHD symptoms were measured by parent report on the widely used Achenbach Child Behavior Checklist. Growth Mixture Modeling was used to model trajectories of ADHD symptoms. However, poor entropy indicated trajectories were not clearly differentiated and predictors could not be examined. Therefore, exploratory regression was conducted to examine predictors of ADHD symptom change from baseline to 3-year follow-up. Male sex, medication use, greater than high school parental education, and better EF all predicted increasing ADHD symptoms. Findings must be interpreted with caution due to their exploratory nature and poor validity of the measure used for ADHD symptoms, which was found to have sensitivity of only 22.58%. Given the strong theoretical and empirical link between ADHD symptoms and EF, additional research on the connection between EF and disorder trajectory with more robust measures of EF is warranted.
Date Created
2024
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Design, Characterization, and In Vivo Applications of a Novel, Concentric, Hybrid micro-ECoG Array

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Description
Neurological disorders are the leading cause of physical and cognitive declineglobally and affect nearly 15% of the current worldwide population. These disorders include, but are not limited to, epilepsy, Alzheimer’s disease, Parkinson’s disease, and multiple sclerosis. With the aging population, an increase

Neurological disorders are the leading cause of physical and cognitive declineglobally and affect nearly 15% of the current worldwide population. These disorders include, but are not limited to, epilepsy, Alzheimer’s disease, Parkinson’s disease, and multiple sclerosis. With the aging population, an increase in the prevalence of neurodegenerative disorders is expected. Electrophysiological monitoring of neural signals has been the gold standard for clinicians in diagnosing and treating neurological disorders. However, advances in detection and stimulation techniques have paved the way for relevant information not seen by standard procedures to be captured and used in patient treatment. Amongst these advances have been improved analysis of higher frequency activity and the increased concentration of alternative biomarkers, specifically pH change, during states of increased neural activity. The design and fabrication of devices with the ability to reliably interface with the brain on multiple scales and modalities has been a significant challenge. This dissertation introduces a novel, concentric, multi-scale micro-ECoG array for neural applications specifically designed for seizure detection in epileptic patients. This work investigates simultaneous detection and recording of adjacent neural tissue using electrodes of different sizes during neural events. Signal fidelity from electrodes of different sizes during in vivo experimentation are explored and analyzed to highlight the advantages and disadvantages of using varying electrode sizes. Furthermore, the novel multi-scale array was modified to perform multi-analyte detection experiments of pH change and electrophysiological activity on the cortical surface during epileptic events. This device highlights the ability to accurately monitor relevant information from multiple electrode sizes and concurrently monitor multiple biomarkers during clinical periods in one procedure that typically requires multiple surgeries.
Date Created
2024
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Bite Force in American Monkfish

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Description
This study examined bite force generation in American monkfish (Lophius americanus) and how it scaled with size, focusing in particular on the roles of the quadratomandibularis (QM) muscle and mechanical advantage in jaw closure in this species. Considering the feeding

This study examined bite force generation in American monkfish (Lophius americanus) and how it scaled with size, focusing in particular on the roles of the quadratomandibularis (QM) muscle and mechanical advantage in jaw closure in this species. Considering the feeding strategy of other anglerfishes, it was hypothesized that monkfish would trend towards force optimization rather than speed optimization in terms of the jaw closing system. The data revealed that bite force has a slightly positive allometric scaling relationship with size, while mechanical advantage was constant throughout growth. Maximum theoretical bite force ranged from 8 N to 87 N, with total lengths ranging from 17 cm to 51 cm. When comparing the bite force of the American monkfish to that of 10 other fish species, small monkfish exhibit a bite comparable to similarly sized species. However, larger monkfish were estimated to have a stronger bite than organisms of similar size.
Date Created
2024
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Innovate to Eradicate: Advancing Public Health Through Novel Vector Control and Surveillance Strategies

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Description
Vector control plays an important role in the prevention and control of mosquito-borne diseases (MBDs). As there are no (prophylactic) drugs and/or vaccines available for many arboviral diseases (such as zika, chikungunya, Saint Louis encephalitis, Ross River virus), the frontline

Vector control plays an important role in the prevention and control of mosquito-borne diseases (MBDs). As there are no (prophylactic) drugs and/or vaccines available for many arboviral diseases (such as zika, chikungunya, Saint Louis encephalitis, Ross River virus), the frontline approach to prevent or reduce disease morbidity and mortality is through the reduction of the mosquito vector population size and/or reducing vector-human contact using insecticides. Frontline tools in malaria (an MBD caused by a parasite) control and elimination have been drugs (targeting the malaria parasite) and insecticides (targeting the vectors) through indoor residual spraying (IRS) (spraying the internal walls and sometimes the roofs of dwellings with residual insecticides to kill adult mosquito vectors), and long-lasting insecticidal nets (LLINs), while arboviral vectors are frequently targeted using outdoor fogging and space spraying (indoor or outdoor spraying of insecticides to kill adult mosquito vectors). Integrative and novel vector control efforts are urgently needed since the aforementioned tools may not be as effective against those mosquito species that are resistant to insecticides and/or have a different (or changed) behavior allowing them to avoid existing tools. In Chapters 2 and 3, I investigate mosquito vector surveillance in Arizona by (i) discussing the species composition and public health implications of the State’s mosquito fauna, and (ii) comparing the effectiveness of 4 different carbon dioxide (CO2) sources in attracting different mosquito species on the Arizona State University Tempe Campus. In Chapters 4 and 5, I investigate a novel vector control tool by (i) completing a literature review on using electric fields (EFs) to control insects, and (ii) presenting novel data on using Insulated Conductor Wires (ICWs) to generate EFs that prevent host-seeking female Aedes aegypti from entering spaces. In Chapter 6, I discuss the non-target effects of chemical malaria control on other arthropods, including other biological and mechanical infectious disease vectors. Overall, this dissertation highlights the important role that the development of novel surveillance and vector control tools could play in improved mosquito control, which ultimately will reduce disease morbidity and mortality.
Date Created
2024
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Longitudinal Mediated Relations Between Screen Time and School Adjustment Through Executive Function Difficulties

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Description
As screen time (ST) constitutes an integral part of the daily lives of young children today, parents, educators, and researchers have started to explore the associations of ST with children’s cognitive, behavioral, and social outcomes. The majority of existing studies

As screen time (ST) constitutes an integral part of the daily lives of young children today, parents, educators, and researchers have started to explore the associations of ST with children’s cognitive, behavioral, and social outcomes. The majority of existing studies have primarily focused on the duration of ST in relation to these outcomes despite the importance of other aspects such as content and type of device in the context of an evolving digital landscape marked by high mobility, ubiquity, and diversity. Addressing this gap, the current study aimed to explore the intricate relations between multiple aspects of ST (i.e., duration and content), executive function (EF) difficulties, and school adjustment in school-aged children, with a particular focus on the mediating role of EF difficulties linking the relations between ST and school adjustment. The current study employed data from the Panel Study on Korean Children, tracking 1,484 South Korean children from third to fourth grade. The duration of ST was measured by the average daily hours spent on smart devices and computers. Parent reports of the levels of engagement in recreational and educational ST and EF difficulties were assessed on Likert scales. School adjustment was reported on by teachers. The results from a half-longitudinal mediation model demonstrated that more frequent engagement in educational ST was related to fewer EF difficulties, which was in turn associated with better school adjustment. The current findings suggest that multiple approaches are needed to effectively guide children’s ST use in their everyday lives and interventions that target EF might be an effective way to promote children's behavioral and social adjustment in school settings.
Date Created
2024
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category FIVE

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Description
In an attempt to summarize two years worth of work in one hundred and fiftywords... This reflection oriented document categorizes my project, “category FIVE”, into chapters of development and actualization. Accounting for the collaborative nature of the project, I advise

In an attempt to summarize two years worth of work in one hundred and fiftywords... This reflection oriented document categorizes my project, “category FIVE”, into chapters of development and actualization. Accounting for the collaborative nature of the project, I advise that this specific document is only half of what the entire work saw through the eyes of Isabella Lepp. Beginning with background information, moving into making the work, and ending with production and reflection of the work, this document follows a mostly chronological timeline in telling the process of making, “category FIVE”, an immersive dance experience. Enjoy.
Date Created
2024
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The Intergenerational Transmission of Depressive and Anxiety Problems: Bidirectional Associations, Racial/Ethnic Differences, and the Mediating Role of Family Processes

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Description
Depression and anxiety are among the most prevalent psychiatric disorders for adults and adolescents and can be intergenerationally transmitted from parents to their children. Moreover, depressive and anxiety disorders often develop during adolescence. Additionally, family environment and the parent-child relationshi

Depression and anxiety are among the most prevalent psychiatric disorders for adults and adolescents and can be intergenerationally transmitted from parents to their children. Moreover, depressive and anxiety disorders often develop during adolescence. Additionally, family environment and the parent-child relationship are significant predictors of mental health among adolescents. Yet, few studies have considered how adolescent depression and anxiety problems may influence the family environment and mental health of parents. Moreover, even fewer studies have examined how depressive and anxious intergenerational pathways may vary by racial/ethnic status. As such, bidirectional effects of parent and adolescent depressive and anxiety problems were investigated using data from the Adolescent Brain and Cognitive Development (ABCD) study at Time 1 (T1)(Mage = 9.92, n=11,861), Time 2 (T2), and Time 3 (T3). Each follow-up was approximately one-year apart. Multiple path analysis models were used to examined bidirectional associations between parent and adolescent A) depressive problems B) anxiety problems and C) depressive and anxiety problems from T1 to T3 and how family conflict and adolescent-reported parental acceptance at T2 mediated these associations. Measurement invariance testing and multigroup analyses were conducted across non-Hispanic White, Hispanic, and non-Hispanic Black participants to examine if depressive and anxious pathways or measurement differed by racial-ethnic status. Findings revealed that both adolescent and parent depression problems at T1 predicted increases in depression at T3. Greater adolescent or parent anxiety problems at T1 predicted increases in adolescent and parent anxiety problems at T3. Greater family conflict and lower perceived parental acceptance at T2 predicted increases in adolescent depressive problems but did not predict adolescent anxiety problems over time. Parental depressive and anxiety problems at T1 did not predict adolescent-reported parental acceptance at T2 but did predict greater family conflict. Measurement noninvariance was found for family conflict and adolescent depressive problems. Multigroup analyses revealed that the association between both depressive and anxiety problems from T1 to T3 was weaker among Black adolescents compared to White and Hispanic adolescents. In summary, this research contributes valuable insights into the measurement of and relationship between parent and adolescent mental health, family dynamics, and adolescent perceived parental acceptance.
Date Created
2024
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A Project-Based Learning Curriculum for Spanish Heritage Language Learners: Implications for Written and Oral Development

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Description
The field of Heritage Language has experienced a great deal of advancement in the past few decades. Much research effort has been dedicated to analyzing and understanding different aspects of heritage language speakers, but less work has been done in

The field of Heritage Language has experienced a great deal of advancement in the past few decades. Much research effort has been dedicated to analyzing and understanding different aspects of heritage language speakers, but less work has been done in the topic of pedagogical approaches. The few recent studies on pedagogical approaches have focused on the “how” of instruction of grammatical points in the heritage language classroom but dedicated less research efforts to an overall and comprehensive approach to classroom teaching and learning at the higher education level. Heritage language learners require teaching methodologies that differ from those used with second language students given their unique characteristics and needs. Having a curriculum and class materials that align to the needs of the students is essential in aiding the development and maintenance of the heritage language of the students. This study explores whether the implementation of a Project-Based Learning (PBL) curriculum can result in measurable gains in the development of written and oral skills in intermediate Spanish heritage language students, when compared to a control group that follows a traditional non-project-based methodology. Fluency, complexity, and accuracy in the written and oral samples were analyzed through a variety of indicators. The data collection consisted of a pre, and post writing and oral sample obtained at the beginning and end of the semester. The results showed that the students in the PBL curriculum achieved greater gains in their written skills when compared to the control group but had no effect on oral skills. The PBL group made significant gains in written fluency and complexity, and moderate gains in accuracy. The control group showed moderate gains in written fluency and complexity, and no improvement in accuracy. Neither group achieved statistically significant gains in oral fluency, complexity, or accuracy after one semester of instruction. The results offer implications for the impact that a PBL curriculum can have on heritage language learner’s linguistic development.
Date Created
2024
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Challenges in Modulation Doping of MoO3 on Hydrogen Terminated Diamond with HfO2 Interfacial Layer

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Description
Diamond transistors are promising as high-power and high-frequency devices having higher efficiencies than conventional transistors. Diamond possesses superior electronic properties, such as a high bandgap (5.47 eV), high breakdown voltage (>10 MV cm−1 ), high electron and hole mobilities [4500

Diamond transistors are promising as high-power and high-frequency devices having higher efficiencies than conventional transistors. Diamond possesses superior electronic properties, such as a high bandgap (5.47 eV), high breakdown voltage (>10 MV cm−1 ), high electron and hole mobilities [4500 and 3800 cm2 V−1 · s−1, respectively], high electron and hole saturation velocities (1.5 × 107 and 1.05 × 107 cm s−1, respectively), and high thermal conductivity [22 W cm−1 · K−1], compared to conventional semiconductors. Reportedly, the diamond field-effect transistors (FETs) have shown transition frequencies (fT) of 45 and 70 GHz, maximum oscillation frequency (fmax) of 120 GHz, and radiofrequency (RF) power densities of 2.1 and 3.8 W mm−1 at 1 GHz. A two-dimensional-hole-gas (2DHG) surface channel forms on H-diamond by transfer doping from adsorbates/dielectrics in contact with H-diamond surface. However, prior studies indicate that charge transfer at the dielectric/ H-diamond interface could result in relatively low mobility attributed to interface scattering from the transferred negative charge to acceptor region. H-terminated diamond exhibits a negative electron affinity (NEA) of -1.1 to -1.3 eV, which is crucial to enable charge transfer doping. To overcome these limitations modulation doping, that is, selective doping, that leads to spatial separation of the MoO3 acceptor layer from the hole channel on H-diamond has been proposed. Molybdenum oxide (MoO3) was used as dielectric as it has electron affinity of 5.9eV and could align its conduction band minimum (CBM) below the valence band maximum (VBM) of H-terminated diamond. The band alignment provides the driving potential for charge transfer. Hafnium oxide (HfO2) was used as interfacial layer since it is a high-k oxide insulator (∼25), having large Eg (5.6 eV), high critical breakdown field, and high thermal stability. This study presents photoemission measurements of the electronic band alignments of the MoO3/HfO2/H-diamond layer structure to gain insight into the driving potential for the negative charge transfer and the location of the negative charges near the interface, in the HfO2 layer or in the MoO3 layer. The diamond hole concentration, mobility, and sheet resistance were characterized for MoO3/HfO2/H-Diamond with HfO2 layers of 0, 2 and 4 nm thickness.
Date Created
2024
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DNA-templated Chemical Synthesis of Proteins and Polypeptides

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Description
Proteins are among the important macromolecules in living systems, with diverse biological functions and properties that make them greatly interesting to study in both structure and function. The chemical synthesis of proteins allows researchers to incorporate a wide variety of

Proteins are among the important macromolecules in living systems, with diverse biological functions and properties that make them greatly interesting to study in both structure and function. The chemical synthesis of proteins allows researchers to incorporate a wide variety of post-translation modifications that can diversify protein functions. It also allows the incorporation of many noncanonical amino acids that enable the study of protein structure and function, as well as the control of their activity in living cells. The work presented in this dissertation focuses on two DNA-templated chemical synthesis approaches for the synthesis of proteins: i) DNA-templated native chemical ligation (NCL), and ii) DNA-templated click chemistry. NCL and its extended version has been used as a powerful tool to obtain proteins; however, it still struggles to make longer proteins due to aggregation and poor yield. To address these issues, a DNA-templated approach is being developed where two peptide fragments are brought into proximity by an oligonucleotide to facilitate the NCL reaction. The sequential ligation of the peptide fragments will result in full-length proteins with increased yield and improved solubility. This research involves synthesis of small molecule auxiliaries, thioester peptides, DNA-peptide conjugates, and ligation of peptides through NCL. This method has the potential to be applied to synthesize large hydrophobic proteins. A DNA-templated click chemistry method was also reported where duplex DNA was utilized as a template for enhancing the copper click reaction between peptide fragments into functional mini-proteins. As a proof of principle, peptide fragments were synthesized with click functional groups and conjugated with distinct DNA handles through a disulfide exchange bioconjugation reaction. The DNA-peptide conjugates were assembled with the template to bring the two peptides into proximity and enhance the effective molarities of the functional groups. The peptides were coupled efficiently using a copper click reaction. The designed DNA-templated method is being implemented to synthesize a designed mini-protein (called LCB1), which can bind tightly to the spike protein of SARS-CoV-2 and inhibit its interaction with the human angiotensin-converting enzyme 2 (ACE2) receptor. This method allows researchers to introduce multiple non-natural amino acids in the protein and has the potential to extend to larger proteins, synthetic polymers, and DNA-peptide biomaterials.
Date Created
2024
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