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Supplementation of Oral Probiotics to Freshly Weaned Lambs When Transitioning to a High Concentrate Diet in Conjunction with Parasite Resiliency to Copper Wire Boluses
No full textRumen health is vital to post weaning health and performance in all ruminant species. Sheep are fed high concentrate diets to improve growth rate, however, these high concentrate diets can lead to acidosis, or even mortality, if not fed correctly. Acidosis is caused by the increased consumption of grain and a drop in pH. The hypothesis that administering a probiotic supplement to lambs prior to and during the feeding period would improve the post-weaning gain as well as decrease mortality. For this study, 93 finewool lambs (n=93; females, n=45, males, n=48) were weaned at approximately 90 days of age and had an average body weight (BW) of 24.7 Kg. Each lamb was assigned randomly to one of the three treatment groups: Control (CON), Treatment 1 (TRT 1), and Treatment 2 (TRT 2). Lambs assigned to TRT 1 and TRT 2 received an oral dose of probiotics (ProBios, Menomonie, WI), which contained four lactic acid producing bacteria: Enterococcus faecium, Lactobacillus acidophilus, Lactobacillus casei, and Lactobacillus plantarum. Lambs in CON received 0g of Probios (n=31, females, n=15; males, n=16), lambs in TRT 1 were administered 10g of Probios on Day 0 (n=31, females, n=15; males, n=16), and lambs in TRT 2 were administered 10g of Probios on Day 0 and Day 7 (n=31, females, n=15; males, n=16). Lambs were housed in groups of three in a fully covered barn with automatic waters. Lambs were sorted into groups by treatment, sex, and initial weight. Lambs were limit fed for 12 days with hay to aid in transition to the high concentrate diet; after the 12 days, they were then fed ad libitum. For six weeks, body weight (BW) and FAMANCHA (FAM) scores were collected. Blood was also collected for the first four weeks and fecal egg counts (FEC) were collected on weeks 1, 4, 5, and 6. There was no interaction between treatment group and weight gain, however, female lambs were statistically lighter when compared to male lambs. Female lambs had a lower FAM score when compared to males.
An additional study of Copper Oxide Wire Particle Boluses (COPWs) was conducted to determine the effectiveness when compared to regularly used anthelmintics. Lambs received an oral drench of Valbazen, Cydectin, and Prohibit (n=44) or a COWP Bolus (n=41). After week one lambs who received oral anthelmintics had a statistically lower FEC when compared to lambs who received COPWs. There was not a significant difference between COPWs and dewormer by Week 2
Systematic Uncertainty Quantification of MCNP Predicted Nuclide Concentrations in Fuel Burnup Simulations
No full textMonte Carlo N-Particle transport code (MCNP) is often used to simulate nuclear fuel burnup and depletion because it is efficient in solving the radiation transport equation for complex geometries. MCNP simulates fuel burnup and estimates the concentrations of actinides and fission products generated in the fuel, which are useful in nuclear forensics as well as safeguards monitoring. During fuel burnup simulations, the uncertainties in the predicted nuclide concentrations due to the uncertainty in the nuclear data used by MCNP are not propagated and predicted. The nuclide concentration is calculated through CINDER 90 isotope generation and depletion module in MCNP. The CINDER90 module uses the neutron reaction rates and flux values computed by MCNP for each burnup time step. The reaction rates can be broken down into three terms: neutron flux, number density of the target isotope that is transmuting, and microscopic neutron interaction cross section. The number density and neutron flux are provided by MCNP; however, the microscopic cross sections are not directly provided by MCNP in the output and will contain systematic uncertainty in varying degrees depending on the microscopic cross section of the target isotope of interest. Systematic uncertainty is not propagated through each MCNP burnup time step. Propagating the effects of systematic uncertainty using a Backward Euler numerical scheme allows for the reporting of the systematic relative error in the predicted nuclide concentrations, which the study undertaken in this thesis. This Backward Euler methodology was executed through python scripting and a program was developed to output the systematic relative error for user desired isotopes of interest utilizing on the results of MCNP fuel burn up simulation. It was concluded that the Backward Euler methodology and the Bateman equations successfully replicated the MCNP estimated concentrations given the appropriate one group cross sections. Additionally, it was determined that for select isotopes of interest the systematic uncertainty for the associated concentration can be estimated
Hardware Approaches for Enabling Multi-Channel Multinuclear MRI/MRS
No full textThis dissertation addresses the challenges faced in exploring X-nuclear possibilities in magnetic resonance imaging and spectroscopy. While proton-based studies are common, the interest in other X-nuclei has grown rapidly. However, limited support from existing MR systems and the challenges in designing multinuclear RF coils hinder these studies. This dissertation proposes a multinuclear RF coil setup and implements two system modification approaches to overcome these challenges.
In X-nuclear studies, the use of double-tuned or multi-tuned RF coils is crucial for examining multiple nuclei without adjusting the setup. This work introduces a three-frequency volume transmit and array receive RF coil setup. The volume transmit coils include a 1H birdcage coil and a double-tuned 2H and 23Na saddle coil, designed to operate individually. A broadband decoupled four-channel receive array is inserted, allowing simultaneous signal reception from all three nuclei. This setup is evaluated through parallel imaging at 1H, 2H, and 23Na frequencies, offering a potential solution for triple-tuned X-nuclear RF coils.
Expanding MR scanners to multinuclear array receiving capability is also explored. This dissertation presents a hardware phase correction solution for receive-only frequency translation, addressing phase incoherence caused by different frequencies between transmit and receive. The proposed hardware utilizes passive phase detectors, a direct digital synthesizer (DDS), and an Arduino microcontroller to automatically correct the received signal phase during the scan and eliminates the need for storing individual echoes or FIDs and performing retrospective phase correction.
Furthermore, the dissertation introduces a cost-effective multinuclear add-on system for traditional MR scanners, enabling simultaneous multinuclear experiments. This system includes multiple transmit and receive mixing channels and a four-channel flexible Local Oscillator (LO) source. By interfacing with the spectrometer, the scanner can transmit and receive at different frequencies simultaneously, reducing experiment time. The results demonstrate simultaneous multinuclear transmit and receive capabilities with 2H and 23Na gradient echo images and interleaved transmit and simultaneous receive ability for 1H, 2H, and 23Na FIDs, showing comparable signal-to-noise ratio performance as the single-frequency operation
Development of an Active Barium Vapor Notch Filter for Ultraviolet Scattering Based Diagnostics
No full textAtomic and molecular filters are proven tools in laser-based diagnostics. Their use as notch filters has greatly expanded the usefulness of scattering phenomena in both ground testing and remote sensing applications. However, current filtering technology limits researchers to the use of the frequency doubled Nd:YAG signal (532 nm) or more rare and complicated lasers such as Ti:Sapphire and Dye lasers. The visible spectrum presents eye safety issues and lacks the molecular scattering signal strength found in the UV. This work aims to develop a vapor filter functioning at the near UV wavelength of the Nd:YAG third harmonic (355 nm). The frequency required for this filter, which utilizes an excited state transition in atomic barium vapor, falls between the ozone absorption region and the retinal hazard region, provides a stronger backscattered signal than visible light, and can be easily attained with the robust and commonly used high-power Nd:YAG laser. These benefits have significant implications for atmospheric measurements, including the aerosol profiling technique of High Spectral Resolution Lidar (HSRL). Through a combined theoretical and experimental effort, a barium vapor filter has been fabricated and characterized for a variety of filter conditions. The results for low vapor pressures of barium are particularly notable and represent the first reported measurements of the absorption feature of interest in the absence of a neutral buffer gas. The addition of a weak argon buffer gas reduced spatial diffusion, resulting in a more stable and deep absorption feature, capable of implementation in scattering based diagnostics. The AURa (Aggie Ultraviolet Rayleigh) Lidar facility has been developed to serve as a testbed for this and other lidar techniques. Aerosol backscatter and extinction results using the novel filter, which mark the first HSRL measurements at 355 nm with a vapor-based filter, will be presented alongside a discussion of the measurement errors and suggested improvements to this system. Finally, a few other applications of the novel filtering approach will be examined
Non-Intrusive Wearable Accelerometry for Early Detection and Monitoring of Chronic Diseases and Mental Health Issues
No full textChronic diseases and mental health issues account for a majority of deaths worldwide. Neuropsychiatric illnesses are a considerable component of this global health burden. Therefore, there is a need for early detection and continuous monitoring of neuropsychiatric illnesses, such as stress, Parkinson's disease, bipolar disorder, and hypoglycemia in patients with diabetes. Traditional monitoring methods, such as medical history, physical examinations, and laboratory tests, have several challenges due to their invasive nature, cost, and continuous monitoring issues.
Wearable technology offers a promising alternative to the traditional methods. Accelerometers, in particular, can provide a non-intrusive, cost-effective, and easy-to-integrate solution suitable for large-scale use. Acceleration data can be combined with machine learning models to provide insights into chronic diseases and mental health issues. Despite the benefits of accelerometer sensors, the use of acceleration data alone has remained unexplored, or it has been used with other physiological data such as heart rate in current literature.
In this dissertation, I study the potential of wearable accelerometer data to detect chronic diseases and mental disorders. In Chapter 1, I review the existing literature that used acceleration data to identify chronic diseases and mental disorders. In Chapter 2, I use wrist-worn acceleration data to detect hypoglycemia in individuals with type 1 diabetes. In Chapter 3, I examine the potential of acceleration data to detect stress in college students. In Chapters 4 and 5, I further extend my findings to stress detection using deep learning models, such as convolutional neural networks (CNNs) and Long Short-Term Memory (LSTM), in two populations: PTSD patients and Intensive Care Unit (ICU) nurses.
My first research (Chapter 2) shows the potential of wearable accelerometers in detecting hand tremors associated with hypoglycemia in diabetic patients. The ensemble of random forest, support vector machines, and K-nearest neighbor models achieved a precision of 81.5% and a recall of 78.6% for hypoglycemia detection. Furthermore, the proposed models for stress detection in college students (Chapter 3) achieved an accuracy of 72.45% for the general population and 78.11% for students with similar movement behaviors. In the PTSD study (Chapter 4), adding power spectral density to raw acceleration data significantly improved the accuracy of hyperarousal detection to 78.45%. Finally, the stress detection models in ICU nurses (Chapter 5) achieved an accuracy of 68.91% using a hybrid CNN-LSTM model.
In conclusion, this Ph.D. research shows the potential of wearable accelerometer data in detecting and monitoring chronic diseases and mental health disorders. The methodologies proposed in this dissertation can be deployed on wearable devices like smartwatches and provide interventions for managing chronic diseases and mental disorders
Electric Powertrain Models for Small UAS Conceptual Design
No full textSmall, battery powered unmanned aerial systems (SUAS) have become indispensable tools for researchers, civilians, and warfighters. However, conceptual designers do not have rigorous tools to design and analyze their electric powertrains which consist of brushless DC motors; therefore, lid-state motor controllers, and lithium polymer batteries. Literature models to analyze the components��� efficiencies rely on detailed information that a vehicle designer cannot practically acquire at the early design stage, such as empirical test data. Therefore, engineers must rely on inaccurate constant powertrain efficiency assumptions which lead to subpar designs. Moreover, existing models ignore the influence of a component���s thermal dynamics on size and performance; therefore, these models could lead to designs that are significantly over or undersized depending on the thermal conditions in which the existing models��� underlying data was collected. Consequently, the resulting designs can overheat or add too much weight penalty in the final vehicle. We have developed a set of efficiency, thermal, and sizing models to address this literature gap in the design and analysis of electric powertrains. We validated these models using wind tunnel tests, motor teardowns, and flight tests. Individually, the models can predict a motor���s efficiency, heat transfer, mass, and electrical constants given high-level inputs which a user can easily find at the conceptual design stage. The models capture the coupled dynamics of a motor���s size, performance, and thermal response. The nuanced results enable users to size the optimal motor for a desired application and given thermal conditions. We also developed efficiency models for the motor controller and battery which rely on fewer inputs than similar literature models, and we validated them with parametric experimental tests. Finally, we developed an instrumentation system that measured and recorded a quadcopter���s propeller torque, propeller speed, and electrical power during flight. We used the flight data to validate an integrated powertrain model that combined the motor, motor controller, and battery efficiency models. The integrated model predicted the vehicle���s battery discharge within 5% of flight data for a six-minute flight. The integrated model enables a user to evaluate different powertrain configurations for an entire mission using readily available inputs
Three Essays on Climate Change Impacts on the U.S. Livestock Sector
No full textThis dissertation contains three essays and their contents are summarized as follows. The first essay contains a literature review regarding climate and climate change related decision possibilities as they impact livestock productivity and decisions. We covered impacts, emissions, adaptation possibilities and mitigation alternatives. We pointed out research gaps on non-ruminant animals and on settings involving developing countries.
The second essay reports on an application of econometric models to explore how climate affects livestock performance. We investigated climate impacts on the productive and reproductive performance for US cattle, hogs and chickens, using temperature humidity index (THI) as a proxy of heat stress. Our results show that climate factors play an important role in livestock productivity. Future climate projections reveal a decrease in all major livestock yield metrics, with the projected changes in yield showing geographical variations across the country.
The third essay reports on an analysis of implications of omitting or including livestock impacts within an agricultural-sector-based climate change impact appraisal. Previous agricultural sector studies have largely ignored impacts on livestock just concentrating on crops. By integrating the livestock impact projections from the second essay, we find introducing livestock impacts causes a 2.5B (22.1%) decline under RCP 4.5
Influence of Microstructural Components on Hydrogen Embrittlement in Alloy 718: Insights from Friction Stir Processing and Additive Manufacturing
No full textHydrogen can cause severe embrittlement of high-strength metal alloys. Nickel alloy 718, a high-strength and corrosion-resistant alloy widely used in the aerospace and oil & gas industries, is highly susceptible to hydrogen embrittlement (HE). The premise of this work is to explore thermomechanical processing to obtain unique fine-grained microstructures in alloy 718. By employing electrochemical hydrogen charging, it aims to advance the understanding of the role secondary phases and grain boundaries (GBs) play in HE behavior. The overarching goal is to identify and propose strategies for the design of HE-resistant alloys.
Firstly, the effect of grain size and precipitates on HE susceptibility is investigated. Under tensile loading, the friction-stir processed and aged (FSP-A) condition with refined grains and precipitates showed substantially reduced HE susceptibility with 12.6% loss of ductility due to hydrogen as measured by reduction in area compared to the coarse grained peak-aged (PA) condition, which lost 29.9%. However, the FSP (with fine grains) and solution-treated (ST, with coarse grains) conditions prior to being aged display similar susceptibility to HE, despite higher hydrogen uptake in the former. The finding that microstructures with refined grains absorb more hydrogen yet have similar or reduced HE susceptibility, demonstrates their HE resistant character.
Secondly, the role of GB character distribution on HE susceptibility in fine-grained alloy 718 was evaluated. Three FSP cases, processed at rotational speeds of 200, 250, and 300 rpm, respectively, with a constant feed rate of 50 mm/min, produced 57%, 65%, and 53% high angle GBs (HAGBs), respectively. Tensile test results show that a high fraction of HAGBs in the microstructure can be correlated to higher HE susceptibility.
Finally, microstructures and properties of alloy 718 produced by selective laser melting (SLM) and subjected to heat treatments (HTs) were investigated. The as-printed material contained 4.7��0.8% volume fraction of the Laves phase, which is reduced to 0.2��0.1% after HT at 1150��C for 2 h. Tailored produced mechanical properties meeting API A6CRA requirements. HE behavior of SLM alloy 718 was similar to wrought alloy 718, with as-printed and aged conditions exhibiting higher HE susceptibility than solutionized conditions, likely by similar HE mechanisms
Mechanisms of Circadian Clock Control of Rhythmic Translation in Neurospora crassa
No full textThe circadian clock in Neurospora crassa regulates daily rhythms in the phosphorylation and daytime inactivation of the conserved translation initiation factor eIF2��. Clock control of eIF2�� activity is responsible for the rhythmic translation of ~15% of mRNAs. Cycling phosphorylated eIF2�� levels require rhythmic activation of the eIF2�� kinase CPC-3 (the homolog of yeast and mammalian GCN2). However, how the clock controls the activity of CPC-3 is not known, and this information is critical to determine the mechanisms underlying rhythmic protein synthesis. To be activated, CPC-3 forms a complex with GCN1, which helps to bring uncharged tRNAs to the tRNA binding domain on CPC-3. In Saccharomyces cerevisiae, activation of GCN2 under stress conditions requires direct interaction of GCN1 and GCN2 with ribosomes. Furthermore, CPC-3 and GCN1 levels are clock-controlled in N. crassa. Based on these data, I hypothesized that N. crassa CPC-3 and GCN1 rhythmically interact with the ribosome, and that this interaction is necessary for rhythmic CPC-3 activity and eIF2��-controlled translation initiation. To test this hypothesis, the interaction of CPC-3 and GCN1 with ribosomes was examined in WT and the clock mutant ��frq. Ribosomes were pelleted from cultures grown in constant dark (DD) and harvested every 4 hours in a circadian time course. I found that CPC-3 and GCN1 interact with monosomes and polysomes, and that the interaction is clock-regulated with peak levels during the subjective day. We showed previously that rhythms in uncharged tRNA levels, and rhythms in CPC-3 activity are abolished in a valyl tRNA synthetase temperature sensitive mutant (un-3ts). The rhythmic interaction of CPC-3 and GCN1 with ribosomes was abolished in the un-3ts mutant, suggesting that rhythmic levels of uncharged tRNA drives the rhythmic interaction of CPC-3 and GCN1 with ribosomes. I found that disrupting the interaction between GCN1 and uncharged tRNA in the absence of GCN20, affects rhythmic CPC-3 activity. Taken together, these data support that clock regulation of rhythms in uncharged tRNA levels and rhythms in the interaction between CPC-3 and GCN1 with ribosomes are necessary for rhythmic CPC-3 activity that leads to rhythms in the translation of target mRNAs
Generational Ethnography in Post-1974 Cyprus: Island Narratives and Shifting (Im)Mobility Through Nation-Making, Belonging, Identity, and Border Realities
No full textThe 1974 conflict and the troubles of the 1960s in Cyprus hold a unique position from an anthropological forced migration studies perspective. The Coup D���etat and the following Turkish intervention in 1974 was the tipping point of the inter-ethnic conflict in Cyprus, which led to thousands of Cypriots becoming refugees through the division of the island. Through extended interviews, this study looks at both Greek and Turkish Cypriot perceptions of the events before the 1974 conflict and the 1974 conflict, casting light on forced migration within the conflict. This study discusses how forced migration and ethnic cleansing divided the once-intermixed ethnic community. Additionally, this study looks at the transgenerational understanding of the ethnic, political, and geographical national divide of Cyprus through the dispersed communities. An understanding of the complex structure of the Cypriots from this study hopes to expedite the solutions to the issues of the current climate of the island