Browsing by Author "Anderson, Brooke, committee member"
Now showing 1 - 13 of 13
Results Per Page
Sort Options
Item Open Access Analysis of 3D facial anthropometric measurements for respirator fit outcomes(Colorado State University. Libraries, 2023) Hobbs-Murphy, Kayna, author; Rosecrance, John, advisor; Brazile, Bill, committee member; Anderson, Brooke, committee member; Morris, Kristen, committee member; Hess, Ann, committee memberAnthropometry is central to the development of efficacious products and environments (i.e., personal protective equipment, clothing, sunglasses, chairs, interior spaces, etc.) used by humans. Three-dimensional (3D) scanning is increasingly common for collecting anthropometric data, as it is faster and less intrusive than traditional manual methods. Additionally, 3D anthropometric methods used to derive facial dimensions provide greater contextual application in the development of respirators and facemasks. More than 2,000 3D facial scans were analyzed to assess measurement reliability and the dimensions of 27 facial features. This research represents the largest sample of 3D facial anthropometrics assessed to date. The three specific aims of the research included: 1) to assess the intra- and inter-rater reliability of 3D facial measurement methods, 2) to compare the 3D facial anthropometric summary statistics from the present study to relevant summary statistics from manual facial measurements found in the literature, and 3) to assess the presence of differences in 3D facial anthropometrics related to respirator fit, based on demographic factors of gender, race/ethnicity, and age. Post hoc analyses were completed to quantify 3D facial measurement differences between demographic groups (within the larger demographic categories of gender, race/ethnicity, and age group). The most notable results of this research include a) high reliability in 3D measurement data collection methods, b) differences in measurement data summary statistics between 3D and manual methods, and c) significant differences in facial measurements between demographic categories of gender (Male and Female/Other), race/ethnicity (White, Black, LatinX, Asian, and Other), and age (18-34, 35-54, and 55-72).Item Open Access Assessing the impact of stratospheric aerosol injection on convective weather environments in the United States(Colorado State University. Libraries, 2023) Glade, Ivy, author; Hurrell, James W., advisor; Rasmussen, Kristen L., committee member; Anderson, Brooke, committee memberContinued climate warming, together with the overall development and implementation of climate mitigation and adaptation approaches, has prompted increasing research into the potential of proposed solar climate intervention (SCI) methods, such as stratospheric aerosol injection (SAI). SAI would reflect a small amount of incoming solar radiation away from the Earth to reduce warming due to increasing greenhouse gas concentrations. Research into the possible risks and benefits of SAI relative to the risks from climate change is emerging. There is not yet, however, an adequate understanding of how SAI might impact human and natural systems. To date, little or no research has been done to examine how SAI might impact environmental conditions critical to the formation of severe convective weather over the United States (U.S.), for instance. We use parallel ensembles of Earth system model simulations of future climate change, with and without hypothetical SAI deployment, to examine possible future changes in thermodynamic and kinematic parameters critical to the formation of severe weather during convectively active seasons over the U.S. Southeast and Midwest. We find that simulated forced changes in thermodynamic parameters are significantly reduced under SAI relative to a no-SAI world, while simulated changes in kinematic parameters are more difficult to distinguish. We also find that unforced internal climate variability may significantly modulate the projected forced climate changes over large regions of the U.S.Item Open Access Causality and clustering in complex settings(Colorado State University. Libraries, 2023) Gibbs, Connor P., author; Keller, Kayleigh, advisor; Fosdick, Bailey, advisor; Koslovsky, Matthew, committee member; Kaplan, Andee, committee member; Anderson, Brooke, committee memberCausality and clustering are at the forefront of many problems in statistics. In this dissertation, we present new methods and approaches for drawing causal inference with temporally dependent units and clustering nodes in heterogeneous networks. To begin, we investigate the causal effect of a timeout at stopping an opposing team's run in the National Basketball Association (NBA). After formalizing the notion of a run in the NBA and in light of the temporal dependence among runs, we define the units under study with careful consideration of the stable unit-treatment-value assumption pertinent to the Rubin causal model. After introducing a novel, interpretable outcome based on the score difference, we conclude that while comebacks frequently occur after a run, it is slightly disadvantageous to call a timeout during a run by the opposing team. Further, we demonstrate that the magnitude of this effect varies by franchise, lending clarity to an oft-debated topic among sports' fans. Following, we represent the known relationships among and between genetic variants and phenotypic abnormalities as a heterogeneous network and introduce a novel analytic pipeline to identify clusters containing undiscovered gene to phenotype relations (ICCUR) from the network. ICCUR identifies, scores, and ranks small heterogeneous clusters according to their potential for future discovery in a large temporal biological network. We train an ensemble model of boosted regression trees to predict clusters' potential for future discovery using observable cluster features, and show the resulting clusters contain significantly more undiscovered gene to phenotype relations than expected by chance. To demonstrate its use as a diagnostic aid, we apply the results of the ICCUR pipeline to real, undiagnosed patients with rare diseases, identifying clusters containing patients' co-occurring yet otherwise unconnected genotypic and phenotypic information, some connections which have since been validated by human curation. Motivated by ICCUR and its application, we introduce a novel method called ECoHeN (pronounced "eco-hen") to extract communities from heterogeneous networks in a statistically meaningful way. Using a heterogeneous configuration model as a reference distribution, ECoHeN identifies communities that are significantly more densely connected than expected given the node types and connectivity of its membership without imposing constraints on the type composition of the extracted communities. The ECoHeN algorithm identifies communities one at a time through a dynamic set of iterative updating rules and is guaranteed to converge. To our knowledge this is the first discovery method that distinguishes and identifies both homogeneous and heterogeneous, possibly overlapping, community structure in a network. We demonstrate the performance of ECoHeN through simulation and in application to a political blogs network to identify collections of blogs which reference one another more than expected considering the ideology of its' members. Along with small partisan communities, we demonstrate ECoHeN's ability to identify a large, bipartisan community undetectable by canonical community detection methods and denser than modern, competing methods.Item Open Access Investigating the impact of forced and internal climate variability on future convective storm environments in subtropical South America: a large ensemble approach(Colorado State University. Libraries, 2023) Chakraborty, Anindita, author; Rasmussen, Kristen, advisor; Hurrell, James, advisor; Anderson, Brooke, committee memberSubtropical South America (SSA) has some of the most intense deep convection in the world. Large hail and frequent lightning are just two of the hazards that profoundly affect people, agriculture, and infrastructure in this region. Therefore, it is important to understand the future convective storm environments over SSA associated with climate change and how these large-scale environmental changes are likely to change high-impact weather events in the future. Previous studies have used convection-permitting regional models and radar data to examine convective storm environments in the current climate across different regions of South America. Here, we use a large ensemble of Earth system model simulations to quantify anthropogenically-driven future changes in large-scale convective environments, as well as how those forced changes might be modified by unforced, internal climate variability. Specifically, we examine changes in different thermodynamic parameters of relevance to severe weather events over SSA in austral spring and summer (September-February). We use daily data from a 50-member ensemble from 1870-2100 performed with version two of the Community Earth System Model (CESM2). Results indicate that no forced changes in convective environments are evident until very late in the 20th century. However, increases in convective available potential energy and atmospheric stability, as well as an increase in lower tropospheric vertical wind shear, became apparent around 1990, and these trends are projected to continue throughout the rest of this century. The implication is that future large-scale environments may be favorable for less frequent, but perhaps more intense and severe convective modes and their associated hazards. Results also demonstrate that anthropogenic changes are likely to be significantly modified, regionally, by internal climate variability.Item Embargo Linking mosquito midgut and virus population biology at the molecular and cellular level(Colorado State University. Libraries, 2024) Fitzmeyer, Emily Anne, author; Ebel, Gregory D., advisor; Stenglein, Mark, committee member; Kading, Rebekah, committee member; Anderson, Brooke, committee memberVector competence (VC) refers to the efficiency of pathogen transmission by vectors. Each step in infection of a mosquito vector constitutes a barrier to transmission that may impose bottlenecks on virus populations. West Nile virus (WNV) is maintained by multiple mosquito species with varying VC. However, the extent that bottlenecks and VC are linked is poorly understood. Similarly, quantitative analyses of mosquito-imposed bottlenecks on virus populations are limited. We used molecularly barcoded WNV to quantify tissue-associated population bottlenecks in three variably competent WNV vectors. Our results confirm strong population bottlenecks during mosquito infection that are capable of dramatically reshaping virus population structure in a nonselective manner. In addition, we found that mosquitoes with differing VC uniquely shape WNV population structure: highly competent vectors are more likely to contribute to the maintenance of rare viral genotypes. These findings have important implications for arbovirus emergence and evolution. The mosquito midgut functions as a key interface between virus and vector. However, studies of midgut physiology and associated virus infection dynamics are scarce, and in Culex tarsalis - the primary vector of West Nile virus (WNV) in the contiguous United States - nonexistent. We performed single-cell RNA sequencing on dissociated, WNV-infected Cx. tarsalis midguts. We identified populations of distinct midgut cell-types consistent with existing descriptions of insect midgut physiology and found that all midgut cell populations were permissive to WNV infection. However, we observed high levels of viral RNA suggesting enhanced replication in enteroendocrine cells and cells enriched for mitochondrial genes. In addition, we found no significant upregulation of mosquito immune genes associated with WNV infection at the whole-midgut level, rather, a significant positive correlation between immune gene expression and WNV viral RNA load at the individual cell level. These findings illuminate the midgut infection dynamics of WNV, providing insight into cell-type specific enhancement of, and immune response to, WNV infection in a primary vector.Item Open Access Occupational injuries among craft brewery workers in Colorado(Colorado State University. Libraries, 2021) Brents, Colleen, author; Rosecrance, John, advisor; Brazile, William, committee member; Anderson, Brooke, committee member; Gibbons, Alyssa, committee member; Biegert, Jeff, committee memberWorkers at craft breweries in the U.S. are an understudied occupational cohort in a rapidly growing industry. Between 2015 and 2019, the number of craft breweries in Colorado grew 120% (Brewers Association, 2020). At the start of 2020, Colorado had more than 420 craft breweries with more than 9,100 workers. California is the only state with more craft breweries than Colorado. In the U.S., 8,000 craft breweries employed 161,000 workers (Brewers Association, 2020). As craft brewery workers produce beer through manufacturing processes, they are exposed to numerous occupational hazards that have been associated with injuries. These hazards include awkward body postures, lifting/carrying heavy loads, highly repetitive activities, sharp edges on materials and equipment, hot surfaces, and high levels of noise. According to national injury surveillance data, occupational injury rates are higher among brewery workers compared to all industries including private, state, and local government. Unfortunately, the national injury surveillance data do not differentiate between large and craft breweries. Craft breweries are substantially smaller than large industrialized breweries. An analysis of national injury data that includes all sizes of breweries may lead to erroneous perceptions of injuries affecting craft brewery workers. To date, no published studies have specifically outlined occupational hazards and injuries associated with craft brewing tasks. To effectively improve safety among craft brewery workers, it is critical that researchers and industry stakeholders have a better understanding of the occupational exposures related to injuries specific to craft brewery workers. The purpose of the present study was to characterize injuries specific to craft brewery workers and to identify their contributing factors in order to inform practitioners tasked with directing intervention resources. Researchers used data from workers' compensation to analyze injuries among Colorado craft brewery workers from 2013 to 2018. Researchers then analyzed accident narratives using the revised agent-host-environment epidemiologic model to better understand the relationship between the reported injury claim and the contributing factors to the agent, host, environment, and vehicle. Informal interviews with subject matter experts supplemented the workers' compensation analysis. Due to restrictions caused by the COVID-19 Pandemic, qualitative data were collected through virtual informal interviews with subject matter experts. Researchers developed a series of injury process models to highlight the relationship between injury characteristics and contributing factors that resulted in an injury nature. These models included information on how an injury nature was the result of an injury event when energy was transferred from the environment or vehicle to the injured workers' anatomical region. Researchers analyzed 570 claims. Results of the present study indicated that new workers experience occupational injuries, as more than 60% of claimants had less than two years of tenure at the time of injury. Among claims that incurred costs, the median total claim cost was $680 and the mean total claim cost was $2,100. Claims associated with sprains/strains incurred the highest costs per claim and the highest cumulative cost. Sprains/strains and contusions were the most frequent injury natures. The low back, hands, and fingers were the most frequently injured body parts. By analyzing accident narratives, researchers determined that injuries in craft breweries were typically associated with claimants either carrying items or performing cleaning tasks. The majority of injuries occurred in the packaging hall area of the craft brewery. Subject matter experts described how the packaging hall typically had the highest number of workers and the greatest proportion of new workers compared to other regions of the craft brewery. Contusions, lacerations, and burns affected the hands/fingers whereas sprains/strains predominately affected the low back. Sprains/strains and contusions both typically occurred in the packaging area of the craft brewery while the claimant carried an item. Lacerations typically occurred in the packaging area or kitchen. Burns typically occurred in the brewery or kitchen. Both burns and lacerations occurred while the worker performed maintenance work, cleaning activities, or food preparation tasks. Findings from this study (including the injury process models) can help guide practitioners tasked with developing interventions to reduce injuries and improve the quality of work life among craft brewery workers.Item Open Access Occupational physical activity in sedentary and active workers(Colorado State University. Libraries, 2017) Thompson, Janalee, author; Rosecrance, John, advisor; Anderson, Brooke, committee member; Crain, Tori, committee memberWith the increasing use of technology in the workplace, many jobs are becoming more sedentary. The purpose of this study was to establish a quantitative baseline measure of occupational physical activity (OPA) in active and sedentary workers. Two activity trackers (Fitbit Charge HR™ and Hexoskin) were used to assess activity measures (step count, heart rate and energy expenditure) among workers during their work shift. The first objective of the study was to assess the agreement between two types of accelerometer-based activity trackers as measures of OPA. The second objective of this study was to assess differences in measures of OPA among workers in physically active and sedentary work environments. There was a statistically significant difference in measures of total step counts between the two devices. When comparing active and sedentary workers there were also statistically significant differences in measures of step counts, mean percent heart rate increase, maximum heart rate range and energy expenditure. Conclusion: The Fitbit Charge HR™ and Hexoskin had significant differences in measures of step counts and heart rate. When comparing active and sedentary workers, there were significant differences in measures of step counts, mean heart rate, maximum heart rate range required by job, and energy expenditure. The results of the present study provide quantitative evidence that active workers require greater physiologic demands than sedentary workers.Item Open Access Public health considerations for a potential Lyme disease vaccine in the United States: cost of illness, vaccine acceptability, and net costs of a vaccination program(Colorado State University. Libraries, 2021) Hook, Sarah A., author; Peel, Jennifer, advisor; Anderson, Brooke, committee member; Bayham, Jude, committee member; Magzamen, Sheryl, committee memberTo view the abstract, please see the full text of the document.Item Open Access Reference values of the distal sensory median and ulnar nerves among newly hired workers(Colorado State University. Libraries, 2021) Hischke, Molly, author; Rosecrance, John, advisor; Neophytou, Andreas, committee member; Anderson, Brooke, committee member; Gerr, Fredric, committee member; Reiser, Raoul F., II, committee memberCarpal tunnel syndrome (CTS) is the most common entrapment neuropathy in the upper extremity and more common among workers in industrial occupations than in the general population (Atroshi et al., 1999; Mattioli et al., 2009; Palmer, Harris, & Coggon, 2007). Because of the high prevalence of CTS in certain industries, some employers have implemented post-offer pre-placement screening programs using nerve conduction studies (NCS) to identify those at higher risk of developing CTS. NCS are commonly used to identify the median neuropathy characteristic of CTS by assessing the nerve conduction speed of the median nerve. There have been a number of retrospective and prospective cohort studies that have examined the relationship between NCS indicating median neuropathy among workers and the subsequent development of CTS (Werner et al., 2001; Franzblau et al., 2004; Gell et al., 2005; Silverstein et al., 2010; Dale et al., 2014). These studies have indicated that workers with NCS indicating median neuropathy across the carpal tunnel who were initially asymptomatic for CTS, eventually developed CTS at a statistically significant greater rate than workers with normal nerve studies. Some employers have used NCS to identify workers at higher risk of developing CTS and placing them into low hand-intensive work tasks to reduce the high prevalence of work-related CTS. To identify workers at higher risk, their NCS results are often compared to population-based reference values. However, many of these published reference values are limited by their small samples sizes and unsuitable statistical methodologies (Dillingham et al., 2016). Further, some researchers have questioned whether population-based reference values are representative of working populations, especially those in industries with a high prevalence of abnormal NCS (Dale, Gardner, Buckner-petty, Strickland, & Evanoff, 2016; Salerno et al., 1998). The purpose of this dissertation research was to (1) establish reference values for NCS outcomes of the distal upper extremity from a large sample (N=17,630) of newly hired manufacturing workers using novel statistical methods more appropriate for nerve conduction data, (2) investigate comorbid conditions associated with nerve conduction outcomes, and (3) determine the sensitivity and specificity of CTS symptoms for identifying workers with median mononeuropathy.Item Open Access Respiratory morbidity in susceptible populations: the role of joint exposure to multiple environmental chemicals and pollutants(Colorado State University. Libraries, 2019) Benka-Coker, Wande, author; Magzamen, Sheryl, advisor; Peel, Jennifer, committee member; Wilson, Ander, committee member; Anderson, Brooke, committee memberExposure to ambient pollution from environmental chemicals and pollutants has been associated with a range of adverse respiratory outcomes; susceptible populations are disproportionately affected. Children with asthma are particularly at risk for adverse respiratory effects of environmental agents. The recent increase in US and worldwide pediatric asthma prevalence has encouraged new lines of inquiry focusing on environmental factors, rather than genetic factors, as the main etiologic agent in asthma-related morbidity; the complex relationship between individuals and their environment requires improved characterization and quantification.Item Open Access Studying the impact of air pollution and pesticide mixtures on respiratory health in Fresno and Tulare counties of central California(Colorado State University. Libraries, 2022) Hughes, Matthew Lawrence, author; Magzamen, Sheryl, advisor; Anderson, Brooke, committee member; Schaeffer, Joshua, committee member; Bosco-Lauth, Angela, committee memberResidents of California's Central Valley are exposed to some of the worst air quality in the United States, as well as high levels of pesticides owing to the region's large agricultural economy. There is ample evidence that exposure to air pollution is associated with adverse respiratory health outcomes, and some evidence from occupational and community-based studies that exposure to pesticides has negative impacts on respiratory health as well. Epidemiologic research on air pollution and pesticides often considers these exposures one at a time in relation to health outcomes, but humans are exposed to pollutants simultaneously in mixtures. In this study we used multiple linear regression models to look at linear relationships of three criteria air pollutants and biomarkers of organophosphates (dialkyl-phosphates or DAPs) with urinary leukotriene E4 (LTE4), a biomarker of respiratory inflammation, in participants in four Central California communities (n=80). We then used Bayesian Kernel Machine Regression models to study these criteria air pollutants and DAPs as a mixture and determine if this mixture had a relationship with respiratory health in this population. We also studied these relationships at two different times of the year (January and June) to study whether and how this relationship between an air pollution-pesticide mixture and the respiratory health outcome changed seasonally. Our multiple linear regression models revealed that dimethyl-phosphates had a statistically significant association with respiratory health in January, which suggests that LTE4 can be used as a biomarker for respiratory inflammation in populations with low asthma prevalence. The results of our BKMR analysis were not statistically significant but did suggest interactions between the exposures in our air pollution-pesticide mixture. Despite a small sample size, this study adds to the limited research on environmental mixtures, and the effects of pesticide exposure on respiratory health.Item Open Access Surveillance affecting infection control in a veterinary teaching hospital(Colorado State University. Libraries, 2017) Ouyang, Ben, author; Morley, Paul, advisor; Schissler, Jennifer, advisor; Anderson, Brooke, committee member; Burgess, Brandy, committee member; Weese, Scott, committee memberHealthcare-associated infections (HCAI) are poorly understood in veterinary medicine. Methicillin-resistant Staphylococcus pseudintermedius (MRSP) is an increasingly reported pathogen of dogs. Consequently, there are increasing concerns regarding treatment difficulties and propagation of antibiotic resistance. The first study seeks to estimate the burden of MRSP carriage among dogs presenting to the Colorado State University Veterinary Teaching Hospital (CSU-VTH). This study enrolled 243 canine patients across 3 different hospital services upon admission to the VTH and 155 canine patients across 3 different hospital services that received paired samples at two different time points. The 3 hospital services were Community Practice (healthy patients), Dermatology (patients with skin disease) and Surgical Oncology (patients with a higher risk of acquiring an infection during visit). The estimated prevalence of MRSP carriage at enrollment and follow-up was 4%. For enrollment samples, no patients enrolled through Community Practice carried MRSP, while 8% of Dermatology patients and 3% of Surgical Oncology patients were MRSP carriers. For paired samples, carriage persistence was only seen for patients enrolled through Dermatology. Results of this study showed that the prevalence of MRSP carriers among dogs presenting to the CSU-VTH falls within ranges previously published. MRSP colonization was seen most commonly among dogs with skin disease and least commonly among healthy dogs. The second study focuses on surveillance for HCAIs via patient temperatures stored in the electronic medical record (EMR) system of a VTH. Little work has been done in veterinary medicine on surveillance of HCAIs in a VTH. The EMR system contains patient temperature data for each visit. This study explores the association between fevers after admission and known risk factors for HCAIs (e.g. duration of stay in the hospital, critical care involvement). This study included all medical records corresponding to canine visits from the period of January 1, 2012 to June 30, 2015. After selecting for visits of ≥ 1 night and removing missing data, 6,254 unique canine visits remained. Visits were classified into type of case (Medicine, Surgery, Oncology, Other) and whether critical care (ECC) was involved). Length of stay was determined based on admission and discharge date. A visit that produced a fever after admission was a visit where the animal had a normal rectal temperature (≤102.5°F) upon admission and subsequently produced a fever (>102.5°F) after admission. The cumulative incidence of fevers after admission was calculated. Odds ratios (OR) between fevers after admission and case type and ECC involvement and duration of stay in the hospital were calculated via multivariable logistic regression. The estimated cumulative incidence of fevers after admission was 9%. Results of multivariable regression showed that a negative association existed between Medicine-type cases, Oncology-type cases and long duration of hospitalization (>2 days). This study shows that fevers after admission are associated with known risk factors for HCAIs and may be useful in a syndromic approach to HCAI surveillance. This study did not explore the association between HCAI and fevers after admission.Item Open Access Using the dog as a model to investigate environmental and genetic risk factors for mature, antigen-driven lymphoproliferative disorders(Colorado State University. Libraries, 2017) Labadie, Julia, author; Magzamen, Sheryl, advisor; Avery, Anne, advisor; Anderson, Brooke, committee member; Feigelson, Heather, committee member; Morley, Paul, committee member; Page, Rodney, committee memberTo view the abstract, please see the full text of the document.