Mountain Scholar

Mountain Scholar is an open access repository service that collects, preserves, and provides access to digitized library collections and other scholarly and creative works from Colorado State University and the University Press of Colorado. It also serves as a dark archive for the Open Textbook Library.

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Colorado State University, Fort Collins 27489
Explore the Colorado State University community’s scholarly output as well as items from the University at large and the CSU Libraries.
Open Textbook Library Archive 25
A limited number of titles are available here. To see all OTL titles, please visit the Open Textbook Library at https://open.umn.edu/opentextbooks. Only Open Textbook Library staff have access to all OTL Archive titles held in Mountain Scholar.
University Press of Colorado 1067
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Recent Submissions

Access status: Open Access ,
Measurement of CP parameters in B- → Dπ+π-π0K- and study of the X(3872) in B → J/ψπ+π-K with the BABAR detector
(2006) Winklmeier, Frank, author; Toki, Walter H., advisor; Hulpke, Alexander, committee member; Harton, John, committee member; Wilson, Robert J., committee member
This dissertation presents two analyses performed on data collected with the BABAR detector at the SLAC PEP-II e+e- asymmetric-energy B Factory. First, a Dalitz analysis is shown that performs the first measurement of CP violation parameters in the decay B- → Dπ+π-π0K- using the decay rate asymmetry and D0 - D-0 interference. The results can be used to further constrain the value of the CKM angle γ. The second analysis studies the properties of the X(3872) in neutral and charged B → J/ψπ+π-K decays. Measurements of the branching ratio and mass are presented as well as the search for additional resonances at higher masses.
Access status: Open Access ,
Autoinducer-2-based quorum sensing of foodborne pathogenic bacteria under food related conditions
(2006) Yoon, Yohan, author; Sofos, John, advisor; Kendall, Patricia, advisor; Ellis, Robert P., committee member; Scanga, John, committee member
The objective of these studies was to evaluate potential involvement of autoinducer (AI)-2-based quorum sensing (quorum sensing: cell density dependent cell-to-cell signaling) of foodborne pathogenic bacteria in food environments. Under the conditions of these studies, AI-2 activity of Salmonella and Escherichia coli O157:H7 was not associated with rate of bacterial growth. Production of AI-2 was increased in the presence of glucose (0.5%), and AI-2 activity of E. coli O157:H7 was not very high in beef purge containing high levels of natural flora. Salmonella and E. coli O157:H7 did not form more (P≥0.05) biofilm on food contact surfaces in the presence of AI-2 activity compared to absence of AI-2 activity, suggesting that AI-2-based quorum sensing may not be involved in biofilm formation by Salmonella and E. coli O157:H7 on food contact surfaces. AI-2-like activity increased (P<0.05) in fresh beef samples inoculated with E. coli O157:H7, containing lower levels of natural flora, and stored at higher temperature (25°C) and under aerobic conditions. Under heat (55°C) and acid stress (pH 3.0 or 3.5), surviving cell counts of Salmonella were not different (P≥0.05) in the presence and absence of AI-2 activity, indicating that AI-2-based quorum sensing of Salmonella may not be involved in heat and acid stress response. Surviving cell counts of E. coli O157:H7 were higher (P<0.05) in the presence than in the absence of AI-2 activity under both heat (52 or 55°C) and acid (pH 3.0) stress, indicating that AI-2-based quorum sensing of E. coli O157:H7 may be partially involved in mechanisms of heat and acid resistance. The results of these studies may be potentially helpful in developing novel approaches for improving food safety, while research on quorum sensing should be continued with the goal of finding targets for pathogen control in foods.
Access status: Open Access ,
The influence of ultraviolet-B radiation on benthic communities in Rocky Mountain streams with different metal exposure histories
(2006) Zuellig, Robert E., author; Clements, Will, advisor; Kondratieff, Boris C., committee member; Tate, Cathy M., committee member; Fausch, Kurt D., committee member
Increased levels of atmospheric CO2 and associated global climate changes over the next 100 years are expected to have significant impacts on riparian vegetation, biogeochemical cycles and hydrologic processes in the Rocky Mountain region. While considerable research has been devoted to understanding these direct impacts of global warming, much less is known about the interactions between climate change and other forms of anthropogenic disturbance. Contamination from historic mining operations is common in many streams in Colorado and is recognized as a major environmental problem. Pollution from historic mining operations coupled with physicochemical characteristics of Rocky Mountain streams (e.g. shallow, low dissolved organic carbon, high elevation) that increase exposure of benthic communities to UVB (280 to 320 nm) provide an opportunity to examine how UVB interacts with metals contamination to structure benthic communities. I integrated a series of UVB addition experiments conducted in stream microcosms with a large-scale UVB removal experiment to test the hypothesis that the influence of UVB is greater on benthic communities from metal-polluted streams compared to reference streams. Fully understanding the influence UVB radiation in aquatic systems requires estimates of UVB dose. Although radiometric equipment is available for quantifying UVB dose, it is expensive and often impractical for continuous use at remote sites. I applied polysulfone (PSF) dosimetry to measure UVB at the water surface in conjunction with estimates of UVB attenuation and stream depth measurements to determine UVB dose to benthic communities in 12 Colorado Rocky Mountain streams over a 60-day period. Average cumulative UVB intensity near the water surface ranged between 12 J/cm2 to 66 J/cm2, while the average amount of UVB reaching the streambed ranged between 25 -71% of UVB measured at the water surface. Nearly 80% of the variation in the amount of UVB reaching the streambed was explained by dissolved organic carbon concentration (DOC). These results indicate that some benthic communities in high elevation Rocky Mountain streams are subject to levels of UVB that are over 70% of surface measurements. Microcosm experiments involved short-term exposure (7-10d) of natural benthic macroinvertebrate communities collected from reference and metal-contaminated sites to lamp-generated UVB. In all cases measures of abundance decreased in UVB-treated streams compared to controls. However, effects of UVB addition on the total abundance of mayflies, Heptageniidae, and Baetis bicaudatus was significantly greater in communities from metal-polluted sites compared to those from reference sites. The field experiment involved removing UVB for 60 days from portions of the streambed at 12 separate 1st - 4th order stream sites along a Zn gradient. Median Zn concentrations at these sites ranged from 5 and 530 μg/L. Results of the field experiment indicated that the removal of UVB significantly increased total abundance and the abundance of grazers, mayflies, caddisflies, Orthocladiinae midges, and the mayfly Baetis bicaudatus compared to controls. Although grazer abundance was significantly greater in UVB removal treatments, no treatment differences were found in algal biomass or Heptageniidae abundance. The metals gradient may have masked the chlorophyll a and Heptageniidae response to UVB removal, as these endpoints are influenced by metal concentration. Alternatively, increased grazing under the UVB removal treatments may have limited algae accrual. As with the microcosm experiments, effects of UVB removal were generally greater at metal-polluted sites than reference sites. This research incorporated the first large-scale field experiment to investigate the direct influence of UVB on benthic communities. Results from both laboratory and field experiments demonstrated that benthic communities in Rocky Mountain streams were negatively influenced by UVB radiation. Benthic response in both laboratory and field experiments was comparable to other studies, but our results demonstrate that benthic communities in Colorado Rocky Mountain streams are negatively influenced by UVB radiation and that communities subjected to long-term metal exposure are more sensitive to UVB than reference communities. As a consequence, the effects of increased UVB radiation reaching the earth's surface may be more severe than previously considered in systems receiving multiple stressors.
Access status: Open Access ,
Global estimate and control of model, numerical, and parameter error
(2006) Sandelin, Jeffrey David, author; Estep, Donald, advisor; Ojima, Dennis, committee member; Tavener, Simon J., committee member; Liu, James, committee member
Ordinary differential equations (ODEs) are used extensively in the modeling of natural phenomena in nearly all scientific and engineering fields. In this thesis, we derive a posteriori error estimates based on adjoint analysis for global error estimation of numerical solutions of ODEs and design and implement various global error control mechanisms. Solution methods are based on continuous and discontinuous Galerkin finite element methods. We take a global approach to error estimation and control by treating the time dependent equations in a manner similar to elliptic problems and solving the equations for the entire time period, then applying a posteriori error estimates based on duality, the adjoint problem, the generalized Green's function, and variational analysis. We develop and explore new approaches to adaptive error control based on probability and weighted zones. These methods are implemented and compared to classic error control based on "Equidistribution of Error" using a variety of test problems. Finally, we provide analysis that shows that modeling error cannot be ignored.
Access status: Open Access ,
Agent-based movement models and landscape connectivity
(2006) Tracey, Jeff Alfred, author; Crooks, Kevin R., advisor; Breidt, F. Jay, committee member; Noon, Barry R., committee member; Theobald, David, committee member
Human-caused changes in landscapes typically result in the loss, degradation, and fragmentation of animal habitats. One consequence of habitat fragmentation is changes in functional landscape connectivity, which, for animals, refers to their ability to move through a landscape among areas of suitable habitat. Our ability to anticipate the consequences of human-caused landscape change on connectivity depends in part on how well we are able to incorporate both animal movement behavior and landscape structure into predictive models for connectivity. In my dissertation research, I have explored various approaches to modeling animal movement and how to use such models to evaluate functional connectivity. Four chapters are presented. The first chapter presents a simple model for studying animal movement response to a single type of landscape feature. We demonstrate the model using data from a red diamond rattlesnake. The second chapter describes an approach for modeling movement and using individual-based movement models to evaluate functional connectivity. Model formulation, computer implementation, and application to connectivity evaluation are described and illustrated using a case study for puma in southern California. The third chapter presents a distance-weighted anisotropic detector model for perception that can be used in agent-based movement modeling. Modeling results suggest that increased anisotropy in the detection space leads to increased directional persistence and decreased use of the most suitable transition habitat. The fourth chapter describes a general approach to agent-based movement modeling and illustrates how to parameterize and evaluate these models using radio-tracking data. Forty-one models for three different puma were fit to data, and model selection was performed using AICc. The best models produced patterns that were consistent with observed data at the move level, but the patterns of nightly net displacement predicted by the best models were not consistent with the observed patterns at this scale; however, this nightly net displacement pattern may be produced by extending the current models to use spatial and temporal covariates. This work improves our ability to model individual-based movement and use such models to study functional landscape connectivity.