Browsing Student Projects and Publications by Title
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- ItemOpen Access3D-printed microfluidic device for the analysis of intestinal tissue ex vivo(Colorado State University. Libraries, 2017) McLean, Ian, author; Schwerdtfeger, Luke, author; Wilson, Jessie, author; Henry, Charles, author; Tobet, Stuart, authorCurrently, most in vitro experimental models of the intestine rely upon cell lines, and consequently, lack the diverse representation of cells present in vivo. Slices of intestine, removed from living organisms, offer a better representation of in vivo physiology. However, current techniques for maintaining intestinal tissue in vitro are not capable of recapitulating the in vivo environment. This project utilizes 3D printing and microfluidic principles to design a device that delivers differential flows of media across the two surfaces of intestinal tissue. The device will enable the investigation of complex biological questions that previous models have been unable to address.
- ItemOpen AccessAccess Solar: venture proposal(Colorado State University. Libraries, 2018) Arnold, Addison, author; Figliolo, Luciana, author; Redburn, Melody, author; Sepp-Peterson, Aurora, authorCommunity solar expands solar energy access by providing homeowners, renters, and businesses equal access to the economic and environmental benefits of solar energy. However, within the industry customer acquisition is a financial and operational challenge for project developers. Access Solar’s services address this by providing a turnkey solution to customer acquisition for developers. Our company streamlines the acquisition process and reaches customers through property management groups, community organizations, and electronic media marking. The market is expected to expand, with capacity experiencing a 44-fold increase from current levels by 2030. Access Solar projects sustained growth, profitability, and positive cash flow.
- ItemOpen AccessActivation of muscle spindle afferents increases force fluctuations in the knee extensor muscles(Colorado State University. Libraries, 2005) Coellen, Eric T, author; Cuaresma, Lindsay S., author; Intlekofer, Karlie A., author; Tracy, Brian L., authorThe purpose of this project was to examine the effect of acute tendon vibration on fluctuations in force during contractions of the knee extensor muscles in young healthy subjects.
- ItemOpen AccessAirborne radar observations of rainband structure in Hurricane Ophelia (2005)(Colorado State University. Libraries, 2017) Razin, Naufal, author; Bell, Michael M., authorOne of the mechanisms proposed for the spin-up of the tropical cyclone (TC) mean tangential (swirling) circulation is the convergence of absolute angular momentum above the boundary layer in the outer-core region, which results in the broadening of the TC wind field. Mid-level inflow associated with TC rainband stratiform precipitation may be instrumental in spinning up the broader circulation and may be important in the development of secondary eyewalls. This analysis shows the concurrent presence of an elevated tangential wind maximum and a distinct mid-level inflow in the stratiform region, consistent with the proposed mechanism for TC intensity change.
- ItemOpen AccessAnalysis of the maintenance work order data in educational institutions(Colorado State University. Libraries, 2018) Besiktepe Karaman, Deniz, author; Ozbek, Mehmet E., author; Atadero, Rebecca A., authorAs a part of facilities management (FM), building maintenance activities occupy a significant role in reaching the goal of delivering an acceptable level of performance while minimizing costs and failures. For institutional organizations, an effective FM approach is required to ensure their buildings function properly. Historical work order data may potentially include a substantial value for assessing the condition of building systems by helping to identify common maintenance activities. This study conducts a preliminary analysis of historical work order data collected from six educational institutions in the State of Colorado and Connecticut in the United States between 2008 and 2018.
- ItemOpen AccessApplication of shape memory polymers in wettability transition on superomniphobic surfaces(Colorado State University. Libraries, 2017) Wang, Wei, author; Salazar, Joshua, author; Vahabi, Hamed, author; Joshi-Imre, Alexandra, author; Voit, Walter E., author; Kota, Arun K., authorSuperomniphobic surfaces are extremely repellent to virtually all liquids. Prior work have emphasized the importance of low solid surface energy and re-entrant texture (i.e., convex or overhang texture) in the design of superomniphobic surfaces. While superomniphobic surfaces with a wide variety of textures have been reported in literature, to the best of our knowledge, there are no reports of superomniphobic surfaces with metamorphic textures (i.e., textures that transform their morphology in response to an external stimulus). In this work, we present the first-ever metamorphic superomniphobic (MorphS) surfaces fabricated with a thermo-responsive shape memory polymer.
- ItemOpen AccessThe art of love: arts engagement as a form of relational maintenance(Colorado State University. Libraries, 2018) Griggs, Anna, authorIn previous research, pro-social relational maintenance interactions have been found to lead to more satisfying relationships (Canary & Stafford, 2004). These relational maintenance behaviors may be especially important among strained relationships, like those between a caretaker and a person receiving care, where caregiver burden can drain the relationship of its joy and satisfaction (Small, et.al, 2003). Using the lens of relational maintenance and satisfaction, this project seeks to discover how community arts engagement programming may play a role in relationship maintenance between couples where one individual has been diagnosed with Alzheimer's disease or dementia and the other serves as their primary care partner. This research puts relational maintenance, arts engagement, and caretaker responsibilities in conversation with one another to more fully realize the therapeutic and relationship-building potential of arts engagement. To do this, observational data was analyzed using Canary and Stafford's (2004) relational maintenance typology as the guiding theoretical framework. Data was collected through video-recorded observations at a four-week arts engagement workshop in partnership with the Museum of Art in Fort Collins. During these workshops, participants and their care partner were involved in mask-making classes designed to promote connection and cognitive stimulation. A total of 12 hours of data were examined for evidence of strategic relational maintenance behaviors used by both the participant and the care partner diagnosed with Alzheimer's disease or dementia. Through the thematic coding of the videos, I identified the extent that participants use strategic forms of relational maintenance behaviors (such as positivity, openness, shared tasks, assurances, and close networks) in their relationships and how the art classes influenced feelings of connection and closeness. This research serves as a small subset of a larger, university-wide grant funded project focus on healthy aging. Ultimately, I hope to discover the extent to which arts engagement can help or play a role in maintaining relationships. If a connection can be made between arts engagement and positive relational maintenance, an argument may be built that arts engagement's positive effects on both health and communication may be more expansive that currently highlighted in literature.
- ItemOpen AccessAsante Sana Energy(Colorado State University. Libraries, 2017) Herman, Keni, authorOur business's goal is to improve conditions in unelectrified rural communities in the Lake Bunyonyi region of Uganda through better access to affordable electricity using a DC solar microgrid. The microgrid has a hub of a solar panels with wires running to 30-50 homes and businesses. Based on research conducted over six weeks in Uganda, we have concluded an average willingness to pay of 20,000 Ugandan Shillings ($5.55 USD) for a month of service. We plan first to complete a pilot project and then to expand. Our ultimate mission is to create a large scale impact for Uganda.
- ItemOpen AccessAssessing genetic diversity and phenotypic plasticity in Cirsium arvense: evaluation with greenhouse trials and ISSR(Colorado State University. Libraries, 2004) Gaines, Todd A., author; Brown, Cynthia S., author; Hufbauer, Ruth A., authorInvasive plant species cause damage to ecosystems and economic loss to land managers. One particularly invasive plant species is Canada thistle (Cirsium arvense). This plant is very difficult to control and is a successful invader in many diverse ecosystems, including cropping systems and non-cultivated lands. If C. arvense is successful because it has adapted genetically to new environments, then these differences may be quantified using experimental observations. The objective of this project is to quantify genetic diversity and site-specific genetic differentiation based on phenotypic responses in common garden trials. Canada thistle specimens from crop and non-crop habitats in two different biogeographic regions of Colorado were used. A second objective is to correlate data from genetic markers with phenotypic data to further quantify genetic diversity in specimens from crop and non-crop habitats in three different regions of Colorado. The greenhouse experiments compared the phenotypic responses of the collected plants to variations in soil fertility and water stress. Leaf tissue DNA collected from the sites was amplified with the inter-simple sequence repeat (ISSR) method and the resulting banding patterns were analyzed for genetic variation. Data from the greenhouse trials indicate a greater response to treatments only in Larimer County non-crop populations. Data from genetic analyses indicate a high level of diversity in the sampled genomes. These data are consistent with the invasive characteristics of C. arvense but indicate that Colorado populations have not genetically differentiated within the sampled ecosystems. More study is warranted to further investigate this question.
- ItemOpen AccessAssessing maize crop water stress using an aerodynamic temperature approach(Colorado State University. Libraries, 2019) Costa Filho, Edson, author; Chavez, Jose L., authorThis study evaluates two methods for determining maize crop water stress index (CWSI) using a surface energy balance coupled with an aerodynamic temperature approach. Data were collected on an irrigated maize field, at a research farm located near Greeley, Colorado, USA, in 2018. The irrigation treatment was subsurface drip. Weather data were measured on-site at 3.3 m above ground level. Remote sensed red (RED) and Near infrared (NIR) surface reflectance data were obtained on-site through radiometry measurements done twice a week. Nadir surface temperature was measured using infrared thermometers kept at 1 m above canopy height. Aerodynamic temperature models developed by Chavez et al. (2005) and Costa-Filho (2019) were used to independently estimate CWSI based on the surface energy balance approach. Independent CWSI from measured surface heat fluxes were used as reference for model performance assessment. Results indicated that estimated CWSI based on Costa-Filho (2019) model had mean bias error (MBE) of -0.01 and root mean square error (RMSE) of 0.08, while model from Chavez et al. (2005) resulted on MBE of -0.24 and RMSE of 0.27. Both models underestimated CWSI values due to negative values of MBE, but Costa-Filho (2019) model improved CWSI estimation by reducing the magnitude of RMSE in 30 % when compared to CWSI estimated using Chavez et al. (2005) aerodynamic model. Therefore, research results indicate that there is evidence that the CWSI approach based on Costa-Filho (2019) model for aerodynamic temperature seems to improve estimation of maize CWSI for semi-arid conditions.
- ItemOpen AccessAssessing the efficacy of treatments for digital dermatitis in organic dairy systems(Colorado State University. Libraries, 2017) Paudyal, Sushil, author; Pinedo, Pablo, authorDigital dermatitis is a major cause of lameness in dairy cows causing pain in the limbs leading to reduced animal welfare and significant economic loss. With strict antibiotic regulations and increasing organic dairies, the clinically validated non-antibiotic treatment options are of great value. The objective of the study was to evaluate the efficacy of treatment of digital dermatitis using different combinations of copper sulfate, iodine, and honey. Cows with M1 and M2 DD lesion score were identified and enrolled in the hoof-trimming chute. Cows were randomized to be treated with one of the three treatment options: Copper sulfate and Iodine (CS-I), Honey and Iodine (HO-I) and Control (CON). All 70 cows were followed up on D3, D12 and D28 and a subsample of 45 cows were followed until d120 to evaluate lesion size, lesion stage, lameness score and pain response. Tissue samples were collected on D3, D28 and D120 to investigate dynamics of microbial metagenomics. The data were analyzed in SAS using PROC MIXED and PROC GENMOD with repeated measures. The results show that 43% of the lesions were found on the left feet and 57% on the right feet. The early erosive form of lesions changes into papillomatous mature form as the lesion progresses irrespective of treatment application. The lesion size differed among treatment groups and the effect varied with different follow-up days (P< 0.05). The lesion decreased for both CS-I and HO-I group till day 12 after which the HO-I group had an increase in lesion size. In contrast to this CON group had a slower decrease in lesion size. The pain response was decreased for CS-I and less for HO-I groups. The odds of pain and the odds of getting a lame cow decreases as the time progresses. Thus, non-antibiotic treatment options are effective in controlling pain and decreasing lesion size up to 12 days. Also, clinical assessment of animals and evaluation of lesions suggest CS-I combination is superior to HO-I and CON group.
- ItemOpen AccessAssessing the variability of snow surfaces(Colorado State University. Libraries, 2016) Thomas, Eric, author; Fassnacht, Steven, authorVariability in snow surface roughness is rarely incorporated into climate or hydrological models, yet it has the potential to have a large impact on both latent and sensible heat for a snow dominated system. We looked at the spatial variability of snow surface roughness using the data collected by the NASA Cold Land Processes Experiment (CLPX) during the winters of 2002 and 2003 for nine 1 km2 study sites across northern Colorado. Black boards were placed perpendicularly into the snow to create a contrast so that pictures could be taken of the surface. The surfaces digitally extracted and the surfaces were detrended to remove random data acquisition biases. The datasets for each board within a study site were then assigned a value based on variability in the surface, standard deviation and categorized based on location. These roughness metrics were then analyzed geospatially to understand their spatial variability and the driving processes.
- ItemOpen AccessAn assessment of numerical weather prediction models in forecasting atmospheric rivers(Colorado State University. Libraries, 2017) Nardi, Kyle M., author; Barnes, Elizabeth A., authorAtmospheric rivers (ARs), narrow corridors of high atmospheric water vapor transport, influence large regions of the West Coast of North America, from southern California to British Columbia and Alaska. Regardless of location, areas influenced by landfalling ARs face various threats and disruptions from excessive rainfall and associated runoff. Therefore, improving forecasts of AR occurrence and characteristics is of great importance to those responsible for protecting life and property. When providing the public with outlooks and warnings related to ARs, forecasters must confront the challenge of assessing the output of different numerical weather prediction (NWP) models. Specifically, forecasters must understand how performance varies across different time scales, geographical regions, and individual models. Prior work, such as Wick et al. (2013), has examined the forecast skill of several NWP models at different lead times, yet as models are continuously updated, a fresh perspective on AR forecast performance is desired. This study aims to assess how different weather forecast models perform at varying lead times and for distinct regions of the West Coast of North America. Re-forecasts from several operational NWP models, obtained from the International S2S Project Database, are run out to approximately 60 days. An atmospheric river detection algorithm is applied to the model output in order to quantify how the models handle such features. The study examines atmospheric river re-forecasts for the West Coast of North America as well as three non-overlapping sub-regions along the coast. The first sub-region extends from southern California to the Oregon border. The second sub-region covers the Pacific Northwest from southern Oregon to the northern extent of Vancouver Island. The third and final sub-region consists of the coasts of British Columbia and southeastern Alaska. Together, these regions represent a large fraction of the AR landfall locations for western North America. Model performance is studied through the lens of AR occurrence, intensity, and location. Results indicate variations in re-forecast skill as a function of lead time, geographic region, and model used. A desired near-term outcome of this work is an increased awareness of both the utility and limitations of NWP models in the prediction of atmospheric river events at short, medium, and long-range leads. A desired long-term outcome is the use of these results as a bridge to understanding what gives rise to the differing characters of atmospheric rivers over the northeast Pacific and how models can improve their depictions of such features.
- ItemOpen AccessAssociations between motor cortex inhibition & gait variability(Colorado State University. Libraries, 2017) Swanson, Clayton W., author; Fling, Brett W., authorMotor cortex inhibition is significantly associated with complex bimanual control of the upper extremities. It remains unclear whether this same relationship exists for the lower extremities. We utilized transcranial magnetic stimulation to assess motor cortex inhibition and wireless, inertial sensors to quantify gait variables to assess how cortical inhibition contributes to the control of gait in healthy, young adults. Gait cycle duration variability was significantly correlated to right motor cortex inhibition. The results of this study indicate that motor cortex inhibition may be associated with complex components of gait in a similar fashion to its association with bimanual control.
- ItemOpen AccessATM and CHK-1 activity in young versus senescent human fibroblasts(Colorado State University. Libraries, 2006) Axelrad, Jessica D., author; Ray, Andrew F., authorATM and CHK1 are two different DNA repair proteins. As such, they are an important factor in preventing tumors caused by multiple damages and subsequent mutations in the DNA strands. As people get older they have an increased chance of getting cancer because their cells have had more opportunities to mutate. We hypothesized that it is also possible a person's chance of getting cancer increases with age because the DNA repair proteins, such as ATM and CHK1, become less efficient with age. Protein activity was evaluated by first damaging cellular DNA in young, middle aged, and senescent human fibroblasts, by exposing them to gamma radiation. A Western blot analysis was then performed to determine the concentration of phosphorylated (or activated) ATM and CHK1 proteins in these different aged cells. The data showed that the ATM proteins become more phosphorylated the more radiation the cells are exposed to (as expected), but that, especially in the 10-G cells, the young and middle aged cells have a higher concentration of activated ATM than the old cells. There is a similar pattern with the CHK1 protein blot. The activated protein concentration increases with an increased dose of radiation, but while the 10-G young and middle aged cells have a significant CHK1 concentration, the near senescent cells do not. This decrease in DNA repair protein activation contributes to a person's increased likelihood of cancer. Not only have the older cells undergone more opportunities for a genetic mutation to occur, but the ability of the cell to repair DNA damage appears to be compromised. Future studies will include DNA repair assays.
- ItemOpen AccessAutomated market trends detection with machine learning(Colorado State University. Libraries, 2019) Nguyen, Hieu, authorThe goal of the project is to create an automated process for detecting growing technologies in the IT sphere using open data. The process consists of 3 main steps. First, online media texts are collected. A model is trained to output a list of topics that appears on the media and are relevant our hi-tech interests. Second, Google search volume time-series for each relevant topic is retrieved. These time-series indicate the topic popularity over time.Third, a machine learning model is trained to automatically recognize whether a Google search volume time-series has consistent growth pattern. This process eventually provides a list of topics whose popularity grows consistently over time. The main contribution of this work lies in the vastly reduced amount of time spent on market research that an analyst normally needs. This process can also be used to search for trends in different industries other than hi-tech.
- ItemOpen AccessAutomated versus manual refractive error measurements in domestic cats(Colorado State University. Libraries, 2017) Cleymaet, Allison, author; Harb, Elise, author; Hess, Ann, author; Freeman, Kate, authorPURPOSE. To compare the results of streak retinoscopy (SR) vs. the Welch Allyn SureSight™ autorefractor (WASS) in normal cats and determine the appropriate WASS setting (WASSadult vs. WASSpediatric) for use in the domestic cat. PROCEDURE/DESCRIPTION. Refractive error was determined in 30 young adult domestic short haired cats (60 eyes) with normal, non-cyclopleged eyes via SR. In 28 cats (56 eyes), refractive error was also determined via WASSadult. In 8 cats (16 eyes), refractive error was also determined via WASSpediatric. Refractive error was determined by both WASSadult and WASSpediatric in 6 cats (12 eyes). Agreement between methods was evaluated with Bland-Altman analysis. Mixed modeling was used to test for difference between methods. RESULTS/OUTCOMES. Mean ± SD SR spherical equivalent (SE) was +1.05 ± 0.97 diopters (D) (n=60 eyes). Mean WASS SEadult was +0.60 ± 1.15 D (n=56 eyes), and mean WASS SEpediatric was +2.75 ± 0.98 D (n=16 eyes). The difference between methods was statistically significant for WASSadult vs. SR (p ≤ 0.001, n=56 eyes), WASSpediatric vs. SR (p = 0.01, n=16 eyes), and WASS_adult vs. WASSpediatric (p ≤ 0.001, n=12 eyes). The 95% limits of agreement for WASSadult vs. SR was (-1.80 D, +0.99 D), WASSpediatric vs. SR was (-0.75 D, +3.55 D), and WASSpediatric vs. WASSadult was (-4.75 D, +0.21 D). IMPLICATION/FUTURE DIRECTION. While there was a significant difference between methods, the level of agreement between SR and WASSadult for measurement of refractive error in the adult domestic cat is reasonable. For WASS, adult setting is recommended for clinical use. Supported in part by the Center for Companion Animal Studies at Colorado State University. None.
- ItemOpen AccessBarriers and norms regarding kidney transplantation on the Pine Ridge Indian Reservation(Colorado State University. Libraries, 2017) Reedy, Julia E., authorAmerican Indian populations in the United States have, in recent years, been plagued by a diabetes epidemic of catastrophic proportions. On the Pine Ridge Indian Reservation, located in southwest South Dakota, discrimination, extreme poverty, rampant unemployment, limited access to healthy foods, and other factors have led the Oglala Lakota population to have the highest rates of End-stage renal disease (ESRD). Despite high rates of ESRD, American Indian populations have the lowest rates of kidney transplantation. This research explores the political economic barriers and cultural norms surrounding kidney transplantation as a treatment option for ESRD on the Pine Ridge Reservation.
- ItemOpen AccessBehind the screens: the women behind Disney films(Colorado State University. Libraries, 2018) Selinske, Kimberly, authorWomen have been part of the Disney company since its inception in 1923, and have always played integral roles in the creation and success of Disney films. This research argues that women need to be reincorporated into the larger Disney history, not simply for inclusivity, but to demonstrate the progressive hiring history of Disney and the astounding impacts women had on the success of Disney films. This research juxtaposes the women behind the screens with the women they created on the screen.
- ItemOpen AccessBimanual control differs between force increment and force decrement(Colorado State University. Libraries, 2018) Alam, Tasnuva, author; Patel, Prakruti, author; Lodha, Neha, authorBackground: Everyday bimanual activities require increasing and decreasing forces to manipulate objects, for example, buttoning a shirt or tying a shoelace. Optimal coordination of increasing and decreasing bimanual forces is quintessential to achieve the overall goal of the bimanual task. However, little is known about differences in force control in bimanual force increment and decrement. Purpose: The purpose of our study was to 1) investigate whether bimanual task performance and force coordination differ in force increment versus force decrement and 2) identify the contribution of force coordination in bimanual task performance while increasing and decreasing forces. Methods: Seventeen right-handed young adults (24.10±3.09 years) performed following tasks involving isometric index finger flexion: 1) maximum voluntary contractions and 2) visually guided force tracking involving gradual force increment and force decrement. Each task was performed in unimanual with the right hand only i.e., control condition and bimanual with both hands together i.e., experimental condition. The force tracking task involved controlled force increment and decrement while tracking a trapezoid trajectory as accurately as possible. We quantified task performance with accuracy and variability of the total force in increment and decrement phases. We measured force coordination of the two forces by computing the time-series cross-correlation coefficient and amplitude of coherence in 0-1Hz. Results: We found reduced accuracy and increased the variability of the total force in force decrement compared with force increment. Further, the peak correlation and coherence amplitude was greater during force decrement than force increment. Finally, the peak correlation coefficient and coherence in 0.5-1Hz predicted total force accuracy and variability across the two phases. Conclusions: We provide evidence that performance (force accuracy and steadiness) in bimanual force decrement is reduced compared with force increment, highlighting that force release is more challenging than force generation in bimanual tasks. Overall, improved bimanual task performance is contributed by reduced coordination of two forces indicating that reduced constraint between the hands facilitates error compensation. However, the implicit strategy is to produce highly coordinated forces while executing controlled force release, impacting the task performance. Clinical implications: Considering the significance of increasing and decreasing forces to manipulate objects, our study provides insight into the fundamental differences in bimanual task performance and force coordination during dynamic force manipulation requiring increasing and decreasing forces. These findings can form the basis to understand how aging and neurological conditions impact bimanual function. Future endeavors should be targeted to evaluate more deep understanding of upper limb motor control and invent protocols for the rehabilitation.