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Browsing by Author "Anderson, G. Brooke, committee member"

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    Data-driven models for subseasonal cyclogenesis forecasts in the east Pacific and north Atlantic
    (Colorado State University. Libraries, 2024) Carlo Frontera, Zaibeth, author; Barnes, Elizabeth A., advisor; Maloney, Eric, advisor; Anderson, G. Brooke, committee member
    Tropical cyclones (TCs) are hazardous and financially burdensome meteorological events. Previous studies have revealed that longer timescale phenomena, including the El Niño Southern Oscillation (ENSO), the Madden-Julian Oscillation (MJO), and African Easterly Waves, influence TC development by modifying large-scale environmental conditions such as vertical wind shear, mid-level moisture, and sea surface temperatures. Statistical models have been developed to forecast TCs in the Atlantic and Pacific basins by incorporating information about ENSO and the MJO. Expanding on this work, we employ logistic regression (LR) and neural network (NN) models with an extended set of variables to predict cyclogenesis on subseasonal timescales for the east Pacific and Atlantic regions. These models utilize ENSO and MJO indices, along with other local environmental information, and demonstrate enhanced forecasting skill relative to models that only use TC climatology. Overall, the NN model shows superior performance compared to the LR model, retaining skill out to three weeks leadtime for the east Pacific, and out to four weeks for the Atlantic basin. The predictive capabilities of the model are demonstrated for the years 1983 and 2021. To gain insights into the decision-making process of the NN models, an AI explainability technique is employed to understand which features are considered important in making the predictions. For both basins, the addition of ENSO and MJO information prove to be essential for the superior forecast skill of the NN model.
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    Mapping the metabolic protein interactome that supports energy conservation at the limits of life
    (Colorado State University. Libraries, 2024) Williams, Seré Anne, author; Santangelo, Thomas, advisor; Hansen, Jeffrey C., committee member; Pilon, Marinus, committee member; Anderson, G. Brooke, committee member; Snow, Christopher, committee member
    Distinct metabolic strategies yield energetic gains from a wide variety of substrates, yet only three overarching methods of energy conservation have been defined: substrate level phosphorylation, the generation of a charged membrane, and electron bifurcation. The dominant theme of known energy conservation mechanisms suggests that energy is conserved through the selective movement and management of electrons, thus essentially all life relies on redox (reduction and oxidation) reactions. Small molecule redox cofactors (such as NAD(P)+) and proteinaceous electron carriers (such as ferredoxins) are employed as electron carriers throughout the biosphere. Proteinaceous electron carriers offer the potential for selective protein-protein interactions to bridge reductive flow from catabolic reactions to the membrane, providing a "proteinaceous electron highway" for efficient electron shuttling. Specific redox protein partnerships have been shown to adapt to changing physiological conditions, suggesting that proteinaceous electron flux is tunable and provides a level of selectivity not possible with small molecule electron transport. While electron flux through a tunable and regulated system of protein interactions can offer exceptional energy conservation strategies, large gaps remain in our knowledge of how electron flux is regulated in vivo. Identification of bona fide in vivo protein assemblies – and how such assemblies dictate the totality of electron flow and thus cellular metabolism – is an important milestone to understand the regulation imposed on metabolism, energy-production, and energy conservation. Resolving the dynamic nature of nanoscale interactions in living systems is arguably the current frontier of molecular biology, and combinatorial methods – which layer multiple in vitro and in vivo techniques with large data analysis – have come to the forefront. This dissertation addresses energy conservation strategies of in vivo protein associations in a model, genetically accessible, hyperthermophilic archaeon (Thermococcus kodakarensis) by mapping the metabolic protein interactome using affinity purification mass spectrometry (AP-MS) and generating engineered strains where fusion proteins selectively redirect electron flux in vivo. Twenty-five proteins involved in distinct metabolic functions were tagged to reveal that each tagged-protein interacts with ~ thirty proteins on average. These interactions connected disparate functions suggesting catabolic and anabolic activities may occur in concert -- in temporal and spatial proximity in vivo. The AP-MS method also refined our understanding of previously determined stable complexes suggesting that protein complexes in vivo likely adapt to redox conditions. Engineered strains linking a proteinaceous electron donor to a proposed electron acceptor were viable and impacted electron flux in vivo. Fusion strains linking a ferredoxin to the hydrogen-generating respiratory system increased hydrogen gas output ~8% on average with one strain showing a ~45% increase over wild type. Fusion strains impacting lipid saturation were shown to inhibit saturation, and future studies aim to determine if electrons can be redirected from the vast reductant sink of lipids to the generation of hydrogen gas, a valuable biofuel.
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    ItemOpen Access
    The effects of a brief mindfulness induction on maternal autonomic activity
    (Colorado State University. Libraries, 2020) Wendt, Kathleen Ellen, author; Coatsworth, J. Douglas, advisor; Lucas-Thompson, Rachel G., committee member; Anderson, G. Brooke, committee member
    Brief mindfulness activities are often included in preventive interventions for parents, but researchers do not know the type and combination of mindfulness components that beget the strongest effects on self-regulation. Focused attention meditation is associated with improved attention and self-regulation, but applications of such in interpersonal stressors are scarce. Using a randomized micro-trial design, the present study tested the effects of a brief mindfulness induction (focused attention meditation) on maternal autonomic processes, specifically change in respiratory sinus arrhythmia and tonic skin conductance level compared to resting state, during a goal-oriented task with her child (n = 40 mothers). Mothers were randomly assigned to listen to either a focused attention meditation or a control educational podcast before participating in an adapted Parent-Child Challenge Task (Lunkenheimer et al., 2017) with their 4.5-6.5-year-old children. A repeated measures linear mixed-effects model with basic covariance structure indicated an interaction effect between time and treatment for change in parasympathetic activity, such that mothers in the experimental group, on average, expressed relatively higher parasympathetic activation immediately following the induction period, compared to mothers in the control group. There were no statistically significant effects related to change in sympathetic activity. These results suggest a brief mindfulness induction can promote maternal parasympathetic processes during and immediately after the meditation. Beyond confirming pilot protocol viability, this work contributes to our understanding of the real-time, intra-individual effects of brief mindfulness inductions in interpersonal contexts.