Open Research Oklahoma (Oklahoma State Univ.)
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Budgets: Their use in farm management
No full textThe Oklahoma Cooperative Extension Service periodically issues revisions to its publications. The most current edition is made available. For access to an earlier edition, if available for this title, please contact the Oklahoma State University Library Archives by email at [email protected] or by phone at 405-744-6311
Use of burned grasslands by migrating birds and the effects of prescribed fire on earthworm prey abundance
No full textFire is a critical ecological disturbance in grasslands worldwide, including in the U.S. Great Plains, where fire was once widespread. Each spring, millions of birds, including many declining grassland species, migrate through this region. Despite the importance of high-quality stopover sites for avian populations, little is known about how migrating birds interact with fire, including their potential use of recently burned areas as migratory stopover locations and how burning affects prey resources. We investigated how the entire community of migrating grassland birds responds to fire and how fire affects earthworms with context to prey availability for birds. We quantified the response of migrating birds to fire using bird survey data collected during spring migration in Osage County, Oklahoma, USA, in a region managed intensively with prescribed fire. We evaluated the influence of time-since-fire on abundance of all passage migrants combined, as well as on densities of 7 bird species on two temporal scales: years-since-fire, and days-since-fire at recently burned sites. Additionally, we investigated a potential mechanistic link between fire and prey availability for one fire-associated bird, the American Golden-Plover, by measuring post-fire dynamics of the earthworm community concurrent with spring migration. We examined how near-surface earthworm abundance varied with respect to days-since-fire at recently burned sites, as well as earthworm species composition at these sites. Migrating birds overall were most abundant in recently burned grasslands, and 6 of 7 species analyzed had highest densities in sites burned in the same season. Three species of birds, including American Golden-Plover, occurred in highest densities immediately (<10-14 days) after fire. Earthworms were most abundant near the soil surface in this same temporal window (<10-14 days since fire). Earthworm species composition consisted primarily of native earthworms, but with some non-native presence. Further research into resources used by birds in recently burned areas is needed to provide full mechanistic understanding of the links between fire and habitat use in this system. We conclude that fire is an essential but overlooked component of the stopover ecology of migrating birds in the Great Plains, potentially providing important prey resources for several species of grassland birds
Influence of divergent resistance training on maximal strength, muscle hypertrophy, motor unit behavior, and muscular endurance
No full textIntroduction: It is well known that increases in strength following resistance training are due to neural and muscle hypertrophy adaptations. However, it is unknown if divergent focused resistance training results in differing adaptations in motor unit behavior to modulate submaximal force when muscle hypertrophy occurs or is attenuated. Additionally, little is known if divergent resistance training can influence motor unit behavior during an absolute muscular endurance task to failure. Methods: Two distinct experiments were conducted to expand on the literature regarding the influence of divergent resistance training on maximal strength, motor unit behavior, muscle hypertrophy, and absolute muscular endurance. The first study investigated the effects of 6 weeks of combined high- and low-load resistance training to high-load only training on maximal strength, muscle hypertrophy, and motor unit recruitment and firing rate patterns during a moderate- and high-intensity muscle actions. The second study examined the influence of divergent training from study one on absolute muscular endurance and motor unit behavior of the vastus lateralis during repetitive muscle actions at task failure. Conclusion: For project one, six weeks of divergent focused resistance-training resulted in similar increases in maximal strength, but different relative change in muscle hypertrophy and motor unit recruitment and firing rate patterns of the vastus lateralis to modulate submaximal moderate- and high-intensity torques. For project two, absolute muscular endurance improved for the combined high- and low-load training group only; however, similar MU recruitment and firing rate patterns were observed for both groups following training. Therefore, neither short-term training intervention altered motor control strategies at task failure
Story of dinosaurs
No full textThis resource will explore the validity of arguments and/or conclusions in dinosaur research through evaluating the scientific evidence. Students using this resource will read, experiment, and evaluate scientific literature surrounding dinosaurs. Students will have the opportunity to work with others to evaluate the plausibility of the dinosaur concepts and theories, and engage in hands-on experiments to add additional information to their interpretations. Students will learn to participate in evaluation mechanisms to assess critical thinking and science literacy
"Buzz" on virtual fencing: Livestock behavior in response to audio cues and electronic stimulation
No full textBefore the introduction of widescale ranching and European settlement in the new world, bison would graze freely across the landscape without manmade barriers like fencing. Today, ranching depends on stable fencing systems to ensure effective grazing management. Fences keep cows from overgrazing in a sensitive area or keep them in an area that needs to be grazed. However, traditional fencing systems can be very expensive and require a lot of labor to maintain and move. Further, in some parts of the US, fences can impede large-scale migrations of native ungulates like pronghorn (Antilocapra americana). The introduction of virtual fencing systems would help to eliminate some of the problems that come with traditional fencing systems. However, when you lack a physical boundary, it is unclear whether cows will stay within target areas. Virtual fencing uses GPS-enabled collars on cattle to understand their movement and grazing habits, but this technology also functions as a deterrent for crossing over virtual boundaries, using aural cues followed by electric stimulation. In this way, they function much like perimeter collars for dogs. For this study, we will use GPS data from cattle collars as well as information about sound triggers and electrical stimulation to determine 1) how long it takes individual cows to respond to aural cues alone, 2) how much variation there is among individual cows in sensitivity to aural cues and 3) overall effectiveness of aural vs. electrical stimulation. Information on cattle behavior will allow ranchers to identify individuals that are less receptive to virtual fencing, removing these from herds. Further, this research will allow us to understand lags in responsiveness to aural vs. electric cues, and how wide these digital boundaries must be to be effective
Spatiotemporal features of microsporogenesis in the cycad species Macrozamia communis
No full textPlant Biology, Ecology and Evolutio
Subnational democracy and journalist repression: Increased violence against journalists in democratic Mexico
No full textExisting theories of democracy and repression expect higher repression in unconsolidated democracies like Mexico. This project examines whether executive constraint, executive competition, or both, or neither matters in reducing journalist repression. I theorize that increased political competition at the local level created an open environment for journalists in Mexico, and that opening made journalists more active in covering critical news. As this critical media role also challenges the authority, and the local authorities are still not constrained sufficiently, local-level governments use repression against threatening journalists. The study expects that increasing competitiveness should have a large and positive relationship with journalist repression at low levels of executive constraint. Conversely, when the executive constraint is high, the effect of competition on repression should be smaller. By employing a comparative case study of the Mexican states, the study partially finds support for the theory. The findings show that most killings are concentrated in high executive constraint and high competition, and more competition leads to more killings given the same amount of constraints. No killings in low constraints, regardless of competitiveness. Finally, No killing in the low constraint states, and all the killings in the high competition. Competition does appear to be a driver of journalist repression, while constraints in the form of divided government do not appear to restrain repression. This surprising result may be partially explained by the high level of organized crime in some Mexican states, as additional data analyzed here suggests. The study also seems to support the “More Murder in the Middle” (e.g., Fein, 1995) hypothesis. I also studied four case studies to complement the major findings. Protection not being assigned or withdrawn before the killing, questionable practice of investigation, or cases being buried implies the state government’s involvement in the killings and that executive constraints are not enough to protect journalists. The study suggests that executive constraints matter more than the executive competition in reducing violence against journalists in newly democratized countries. The study also suggests that political competition without sufficient constraints in higher but unconsolidated democracies is dangerous for the safety of journalists
Protein complex from human milk enhances the activity of antibiotics and drugs against Mycobacterium tuberculosis.
No full textMycobacterium tuberculosis, the causative agent of human tuberculosis (TB), has surpassed HIV/AIDS as the leading cause of death from a single infectious agent. The increasing occurrence of drug-resistant strains has become a major challenge for health care systems and, in some cases, has rendered TB untreatable. However, the development of new TB drugs has been plagued with high failure rates and costs. Alternative strategies to increase the efficacy of current TB treatment regimens include host-directed therapies or agents that make M. tuberculosis more susceptible to existing TB drugs. In this study, we show that HAMLET, an α-lactalbumin-oleic acid complex derived from human milk, has bactericidal activity against M. tuberculosis HAMLET consists of a micellar oleic acid core surrounded by a shell of partially denatured α-lactalbumin molecules and unloads oleic acid into cells upon contact with lipid membranes. At sublethal concentrations, HAMLET potentiated a remarkably broad array of TB drugs and antibiotics against M. tuberculosis For example, the minimal inhibitory concentrations of rifampin, bedaquiline, delamanid, and clarithromycin were decreased by 8- to 16-fold. HAMLET also killed M. tuberculosis and enhanced the efficacy of TB drugs inside macrophages, a natural habitat of M. tuberculosis Previous studies showed that HAMLET is stable after oral delivery in mice and nontoxic in humans and that it is possible to package hydrophobic compounds in the oleic acid core of HAMLET to increase their solubility and metabolic stability. The potential of HAMLET and other liprotides as drug delivery and sensitization agents in TB chemotherapy is discussed here.Microbiology and Molecular Genetic
ArchivesSpace and covid-19 – radically altering plans for a telecommute environment: how one large academic library is implementing ArchivesSpace
No full textCovid-19 has radically changed most special collections work environments. The initial nine-month plan to begin implementing ArchivesSpace at the University of Oklahoma (OU) – completed just prior to receiving stay-at-home orders – had to be immediately altered to accommodate the new telecommute environment. We went from having an extended planning period, to a plan-as-you-go model. This has obviously been a challenging shift, but has had a number of positive benefits. While always aiming towards the same goals of providing better, standardized access to information about our collections, we’ve been able to provide meaningful work for special collections staff that have found themselves away from the collections that normally fill their days. We have also been able to onboard a number of other library staff members whose day-to-day work was limited by an inability to be “in the office.” Thanks to the number of people now dedicated to this project, our timeline for near-complete implementation of ArchivesSpace has been drastically shortened: from a process that might have taken 2-3 years, to one we hope to complete before January 2021. Other benefits will be discussed, as well as tools we have used for remote project planning, data clean-up, and ingest of legacy finding aids.Librar
Green and sustainable synthesis of silver nanowires using batch and millifluidic processes and their applications in conductive inks
No full textThis dissertation focuses on the solution-based synthesis of one-dimensional (1D) silver nanostructures (mainly silver nanowires) using green, sustainable, and cost-efficient materials and processes, and application of 1D silver nanostructures in conductive inks formation for printed circuit boards (PCBs) application. Conventional chemical and physical processes used for the synthesis of metallic nanostructures, in general, suffer from hazardous waste production, usage of unsustainable reagents, high energy consumption, and high production cost. However, recent research proves that plant-based products such as polyphenols can serve as proper alternatives (as the reducing/capping/stabilizing agents) to produce nanostructures with different sizes and morphologies, if the process parameters are controlled properly. In such processes, hazardous waste production can be significantly limited if not eliminated, and energy consumption can be minimized. This research firstly investigates the synthesis of silver nanostructures with different sizes and morphologies by sustainable and environmentally-friendly—aka. “green”—reagents (reducing/capping agents), and discusses possibilities for the green synthesis of 1D silver nanostructures, such as silver nanowires (AgNWs). Afterward, a novel procedure for the synthesis of AgNWs, with moderate yield (~50%), using tannic acid in a batch process is introduced. Then, the effect of different parameters such as pH, silver precursor/reducing agent concentration ratio, light, and stirring rate on the yield of silver nanowires, and the size and morphology of silver nanostructures, was investigated. The synthesis procedure is then tried in a continuous millifluidic reactor to increase the yield of silver nanowires by ~32%. The millifluidic process can improve mass and heat transfer, thanks to its miniaturized environment, and a more consistent control over the size and morphology of nanostructures. The silver nanowires synthesized using tannic acid were then used for conductive ink preparation. The rheological behavior of the conductive ink was investigated, which provides valuable information about the flow of the ink and its behavior during screen printing and direct writing. It was demonstrated that the direct writing method can be a simple and efficient procedure to print silver nanowire-based conductive ink. The environmentally-friendly, sustainable, and inexpensive synthesis of AgNWs, and the direct-write printing process, can significantly reduce the production cost of silver nanowire-based PCBs