Digital Commons Network^™

Effects Of Elevated Temperature On 8-Ohdg Expression In The American Oyster (Crassostrea Virginica): Induction Of Oxidative Stress Biomarkers, Cellular Apoptosis, Dna Damage And Γh2ax Signaling Pathways, Md Faizur Rahman, Mohammad Maruf Billah, Richard Kline, Md Saydur Rahman

School of Earth, Environmental, & Marine Sciences Faculty Publications

Global temperature is increasing due to anthropogenic activities and the effects of elevated temperature on DNA lesions are not well documented in marine organisms. The American oyster (Crassostrea virginica, an edible and commercially important marine mollusk) is an ideal shellfish species to study oxidative DNA lesions during heat stress. In this study, we examined the effects of elevated temperatures (24, 28, and 32 °C for one-week exposure) on heat shock protein-70 (HSP70, a biomarker of heat stress), 8-hydroxy-2’-deoxyguanosine (8-OHdG, a biomarker of pro-mutagenic DNA lesion), double-stranded DNA (dsDNA), γ-histone family member X (γH2AX, a molecular biomarker of DNA damage), …

The Spatial And Temporal Distribution Of Large Rock Blocks And Control On Landscape Evolution In The Ozarks, Chelsea Moran

Graduate Theses and Dissertations

Geologists often use landscape form to infer landscape processes through time. While climate and tectonics shape geomorphic form, the potential range of spatial or temporal scales that can shape any specific landscape can render landscape process-form based hypotheses too general for consideration. Contributions by mathematical modeling have helped bridge the gap between inferring processes from form, notably in how sediment transport dynamics shape hillslopes. However, few models encapsulate the movement of large rock blocks ( >2 meters across) and their potential impact as hillslope sediment transport disruptors. The Upper Buffalo River watershed (BRW) in the Ozarks of northern Arkansas has …

Geospatial Analysis Of Weathering And Recession On Architectural Limestone At The 1891 Powerhouse/Icehouse In Eureka Springs, Arkansas, Stuart Bruce Wright

Graduate Theses and Dissertations

The objective of this study of the architectural limestone of the 1891 Powerhouse/Icehouse in Eureka Springs, Arkansas was to analyze the environmental factors that influenced the deterioration and surface recession of this historical stone structure. The focus of this research was to examine and establish a baseline study that may assist in future monitoring and documentation of this historic limestone structure on stone weathering. A replicable methodology was specifically created toward this baseline research in hopes that it represented a solid baseline study. Observations and data analyses revealed the relationship between the architectural limestone building structure and the dominating recession …

Constraining Silicate Weathering During The Middle Eocene Climatic Optimum (Meco) Using Radiolarian Ge/Si, Olivia R. Laub

All Graduate Theses and Dissertations, Fall 2023 to Present

Silicate weathering has long been considered a fundamental component of the earth system and has been cited as one of, if not the primary stabilizing feedback for climate. However, recent work has shown that the role of silicate weathering in the climate system is more complicated and dynamic than previously assumed. In this study I examine the role of weathering in the enigmatic warming event, the Middle Eocene Climatic Optimum (MECO) that occurred approximately 40 Ma. This event works as a good case study as there are multiple features of the MECO that differentiate it from other warming events that …

Tropical Atlantic Temperature And Hydrologic Shifts During The Paleocene-Eocene Thermal Maximum, Chels Howard

All Graduate Theses and Dissertations, Fall 2023 to Present

The Paleocene-Eocene Thermal Maximum (PETM) is a geologic climate event that is studied heavily due to the similarities to anthropogenic climate change. This event occurred approximately 56 million years ago (Ma) and is characterized by a rapid release of carbon into the atmosphere, which resulted in an increase in temperature and a change in global climate events such as changes in patterns of evaporation and precipitation. We see this effect occurring in modern anthropogenic climate change due to the burning of fossil fuels releasing carbon dioxide (CO₂) into the atmosphere. In this study I use elemental data of …

Reducing Inputs And Adding Value To Turfgrass Systems Through Clover Inclusion And Plant Growth-Promoting Rhizobacteria Applications, Paige E. Boyle

All Graduate Theses and Dissertations, Fall 2023 to Present

Recently, the US has seen an expansion in the amount of turfgrass land cover (lawns, parks, roadsides, sports fields, and golf courses), as well as an interest in reducing fertilizer, water, and pesticide use in these grass systems. To help maintain quality and function while reducing resource inputs, two promising approaches have emerged: planting clover into lawns and applying plant growth-promoting rhizobacteria.

White clover and grass mixtures have been studied for their ability to cut down on fertilizer usage and provide a uniform, dark green lawn, but other clover types have not been as widely studied and may provide similar …

Ecology And Management Of Dyer's Woad (Isatis Tinctoria) In Northern Utah, Erin Marie Hettinger

All Graduate Theses and Dissertations, Fall 2023 to Present

Dyer’s woad (Isatis tinctoria L.) is a non-native forb that continues to threaten natural areas throughout Northern Utah and much of the Intermountain West. Once introduced, dyer’s woad can become extremely invasive, decreasing forage quality, and displacing native species. While dyer’s woad is found throughout much of Northern Utah, its range in other states remains limited. If promptly managed, control success in these areas will be much higher and populations may be kept at bay before ecological damage becomes severe.

This project tested the ability of dyer’s woad seedlings to compete with common rangeland grasslands at varied densities as …

Enhancing Our Understanding Of Ancient Oceans Through The Investigation Of Molybdenum Behavior Under Sulfidic Conditions, Rachel Faye Phillips

Open Access Theses & Dissertations

The most abundant trace metal in the ocean today, molybdenum (Mo), exhibits distinct behavior in oxygenated water, where it remains predominantly dissolved, compared to euxinic (i.e., oxygen-free and sulfidic) water, in which it is sequestered into the sediment. This dissimilar behavior allows us to use Mo concentrations and isotopic compositions in sediment to reconstruct marine oxygenation conditions throughout geologic history. However, Mo sequestration mechanisms under euxinic conditions remain unresolved, which limits the accuracy and precision of reconstructions made using Mo signatures in the rock record. For my doctoral research, I experimentally investigated abiotic and biotic Mo sequestration mechanisms under various …

Quantifying The Role Of Water Quality On Nitrogen Cycling In A Trophic Estuary, Kayla Gonzalez-Boy

Symposium of Student Scholars

Jobos Bay Estuary is an intertidal, tropical estuary located in southern Puerto Rico. The estuary covers about 12 km² and has a variety of habitats, such as seagrass beds, mangroves, mud flats, and coral reefs, which play important roles in sediment trapping and water quality maintenance. Seagrasses also serve as nursery and feeding grounds and provide shelter for macrofauna. Currently, the role of seagrasses and water quality on nitrogen (N) cycling in trophic estuaries is not well constrained. Understanding variations in sediment-based effects on N cycling rates and transformations, and how they are associated with water quality, is an …

Water Chemistry And Pigment Composition Of 13 Lakes And Ponds In Maritime Antarctica, Korhan Özkan

Turkish Journal of Earth Sciences

The Antarctic Peninsula has been rapidly warming, resulting in changes to the abundance and surface cover of terrestrial aquatic ecosystems, as well as their ecosystem structure and function. Therefore, comparative studies of aquatic ecosystems across large latitudinal gradients can be useful in better understanding these changes and making more reliable predictions regarding the consequences of climate change. During Turkish Antarctic Expeditions in 2018 and 2019, samples were collected from 10 lakes and 3 ponds across Maritime Antarctica (north-western coasts of the Antarctic Peninsula). These lakes and ponds were located on Ardley, Robert, Livingstone, Galindez, and Horseshoe islands, covering a latitudinal …

Geochemistry Of The Lake Sediments On Robert Island, South Shetland Islands, Antarctica: Implications For Weathering Processes In Polar Areas, Merve Özyurt, Yilmaz Demi̇r, Korhan Özkan, Rai̇f Kandemi̇r

Turkish Journal of Earth Sciences

The preliminary results of geochemical analyses of the surface sediments from 4 lakes on Robert Island, South Shetland, Antarctica, are presented herein. The samples were collected during the Turkish Antarctic Expedition (TAE-II) in 2018. Sediment samples were obtained from the littoral zone (approximately 20 cm) of 4 different lakes exposed on the glacier-free land area on Robert Island. The lake sediments predominantly consist of fine-grained sand, clay, and silt particles. These particles include Fe-shale and graywacke geochemical characteristics. Their plagioclase index of alteration, chemical index of weathering, chemical index of alteration, and other weathering index values, suggest that the studied …

Effect Of Different Pre-Growth Temperatures On The Survival Kinetics Of Salmonella Enterica And Listeria Monocytogenes In Fresh-Cut Salad During Refrigerated Storage, Avninder Kaur, Veerachandra K. Yemmireddy

School of Earth, Environmental, & Marine Sciences Faculty Publications

The effect of the pre-growth temperature of bacterial cultures on their subsequent survival kinetics in fresh-cut produce during refrigerated storage was investigated in this study. Three-strain cocktails of Listeria monocytogenes and Salmonella enterica, cultured at different growth temperatures (4, 21, and 37 °C) were inoculated on fresh-cut mixed salad and on individual produce in the mixed salad. The inoculated samples were stored at 4 °C and 80 ± 2% relative humidity (RH) for up to 72 h and the growth, survival, or death kinetics were determined at regular intervals. The results indicate that depending upon the type of pathogen …

Emerging Sensing, Imaging, And Computational Technologies To Scale Nano-To Macroscale Rhizosphere Dynamics – Review And Research Perspectives, Amir H. Ahkami, Odeta Qafoku, Tiina Roose, Quanbing Mou, Yi Lu, Zoe G. Cardon, Yuxin Wu, Chunwei Chou, Joshua B. Fisher, Tamas Varga, Pubudu Handakumbura, Jayde A. Aufrecht, Arunima Bhattacharjee, James J. Moran

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

The soil region influenced by plant roots, i.e., the rhizosphere, is one of the most complex biological habitats on Earth and significantly impacts global carbon flow and transformation. Understanding the structure and function of the rhizosphere is critically important for maintaining sustainable plant ecosystem services, designing engineered ecosystems for long-term soil carbon storage, and mitigating the effects of climate change. However, studying the biological and ecological processes and interactions in the rhizosphere requires advanced integrated technologies capable of decoding such a complex system at different scales. Here, we review how emerging approaches in sensing, imaging, and computational modeling …

Understanding Marsh Elevation And Accretion Processes And Vulnerability To Rising Sea Levels Across Climatic And Geomorphic Gradients In California, Usa, Karen M. Thorne, Mckenna L. Bristow, Lyndsay L. Rankin, Katya E. Kovalenko, Justine A. Neville, Chase M. Freeman, Glenn R. Guntenspergen

State & Federal Reports and Publications

Tidal marshes build elevations by below- and aboveground organic and mineral soil processes. Marsh elevation and accre- tion data can be used to determine if marshes are keeping pace with sea-level rise. Using a network of 54 deep rod surface elevation tables with paired feldspar marker horizon plots, we tracked elevation and accretion trends across 16 marshes in California, USA. All sites had overall positive gains across years that included severe drought conditions and extreme rain events. Marsh elevation relative to tidal datum (z*) was the key predictor for elevation and accretion rates, with higher change rates at lower z* …

Tidal Bed Stress Asymmetry And Sediment Transport In Estuaries, Austin Scott Hudson

Dissertations and Theses

Rivers and estuaries provide numerous ecological, economic, and cultural resources. The value of these resources is greatly influenced by sediment transport processes, which can be affected by human activities and climate variability. A key driver of sediment transport in tidal rivers and estuaries is tidal asymmetry of velocity and bed stress, which can manifest from both non-linear tidal interactions and linear interactions among astronomical tidal constituents.

In this study, an analytical framework is developed to examine and describe the dynamics of bed stress asymmetry in semidiurnal, diurnal, and mixed-tide estuaries (Chapter 1). While tidal velocity asymmetry has been previously analyzed, …

The Seasonal Origins And Ages Of Water Provisioning Streams And Trees In A Tropical Montane Cloud Forest, Emily Burt, Gregory R. Goldsmith, Roxanne M. Cruz-De Hoyos, Adan Julian Ccahuana Quispe, A. Joshua West

Biology, Chemistry, and Environmental Sciences Faculty Articles and Research

Determining the sources of water provisioning streams, soils, and vegetation can provide important insights into the water that sustains critical ecosystem functions now and how those functions may be expected to respond given projected changes in the global hydrologic cycle. We developed multi-year time series of water isotope ratios (δ¹⁸O and δ²H) based on twice-monthly collections of precipitation, lysimeter, and tree branch xylem waters from a seasonally dry tropical montane cloud forest in the southeastern Andes mountains of Peru. We then used this information to determine indices of the seasonal origins, the young water fractions …

Ortho-Fluoro Or Ortho Effect? Oxidative Addition Of Zerovalent Nickel Into The C–Cn Bond Of Substituted Benzonitriles, Tülay Ateşin, William D. Jones, Abdurrahman C. Atesin

School of Earth, Environmental, & Marine Sciences Faculty Publications

A recent study of the oxidative addition of zerovalent Ni to the C–CN bond of F-substituted benzonitriles showed significantly increased stabilization of the C–CN oxidative addition products with o-F groups (−6.6 kcal/mol per o-F) compared to m-F groups (−1.8 kcal/mol per m-F). To answer the question of whether this is an o-F effect or an ortho effect, in this study the effect of CF3 and CH3 groups on the oxidative addition of the [Ni(dmpe)] fragment [dmpe = 1,2-bis(dimethylphosphino)ethane] to the C–CN bond of benzonitriles has been studied. A density functional theory study of the reaction …

Brachiaria Spp. (Syn. Urochloa Spp.) Cv. Mulato Ii (Convert Hd364) Mass Production Under Continuous Grazing In The Water/Dry Transition Period, A. L. A. Castro, A. C. Prado, M. C. Silva Júnior, M. S. Soares, M. V. Teixeira

IGC Proceedings (1977-2023)

In the transition period between the rainy and dry seasons there is decreased water, temperature and luminosity, reducing forage production and quality. Because of this variability in forage mass production, it is essential to quantify forage mass for use in planning and decision making about pastures management. The objective was to evaluate Brachiaria spp. (Syn. Urochloa spp.) cv. Mulato II (Convert HD364) growth, biomass production managed under continuous grazing with steers fed with protein supplement feed in-trough and on-ground during the seasonal transition period. The experiment was carried out in the Beef Cattle Sector of Jatai Federal University …

Production And Persistence Of Self-Regenerating Annual Clovers In The Pacific Northwest, Ian Silvernail, Serkan Ates

IGC Proceedings (1977-2023)

Self-regenerating annual legumes are commonly included in dryland pastures to increase the production of high-quality forages to meet the nutritional demands of growing and lactating animals. Balansa clover (Trifolium michelianum Savi), not as widely evaluated as subterranean clover (Trifolium subterraneum L.), has shown promise in Western Oregon. However, there is a paucity of information on the productivity and persistence of annual clover cultivars that have various flowering times. This study investigates the biomass production and persistence of early, mid and late flowering subterranean clover and balansa clover cultivars in Corvallis, Oregon. Averaged across the cultivars, the total annual …

Current Red Clover Breeding Research, Heathcliffe Riday

IGC Proceedings (1977-2023)

Red clover remains a globally important forage legume grown mostly in humid temperate climates on approximately 4 million ha. In the past 25 years global red clover seed production has stabilized around 10 million kg yr^-1, although there is evidence that seed production is increasing globally at around 0.34 million kg yr^-1 since the early 2000s. Globally many red clover programs exist targeting specific global regions with a focus on improving persistence, biomass yield, seed yield, and a few other minor traits. Breeding programs are increasing persistence by selecting for specific disease resistances, specific agricultural conditions such …

Managing Vegetation In Grassland Habitats To Enhance Livestock Or Wildlife Objectives, B. B. Sleugh, S. Flynn, W. Hatler, C. Hart, S. Ingram, Joao B. Cason, D. Ovalle

IGC Proceedings (1977-2023)

Sustainably stewarding grassland systems involves applying various practices to manipulate forage interactions with other plants, the environment, and grazing animals to meet resource manager objectives. These interactions can result in invasion or encroachment and increased abundance of weeds which hinder attainment of management objectives. Weeds influence the structure and function of pasture ecosystems whether forages are grown in improved pastures, rangeland, or grassland communities. They degrade pasture quality and reduce livestock performance by interfering with forage establishment, yield, and quality by competing for resources. Weeds reduce the feed value of forage, decrease pasture carrying capacity, and can be toxic or …

Forage Allowance And Daily Gain Relationships On Rye-Ryegrass Pastures At Different Stocking Rates With Continuous And Rotational Stocking, F. M. Rouquette Jr., K. D. Norman, C. R. Long, E. Van Santen

IGC Proceedings (1977-2023)

‘Maton’ cereal rye (Secale cereale L.) and ‘TAM-90’ annual ryegrass (Lolium multiflorum Lam.) are used for winter annual pastures to background stocker cattle in the southeastern US. Rye and ryegrass were sod-seeded into bermudagrass [Cynodon dactylon (L.) Pers.] pastures and fixed-stocked at different rates under continuous and 8-paddock rotation methods during each of 7 years to: 1) compare stocking methods for daily gain per animal (ADG) and gain/ha; and 2) quantify relationships of ADG with forage mass and forage allowance. Each of 3 levels of stocking rate, 4.9, 6.4, and 8.6 hd/ha, significantly affected ADG at 1.24, …

Characteristics Of Lactic Acid Bacteria Strains Isolated From Tibetan Plateau And Their Effects On Silage Quality Of Italian Ryegrass (Lolium Multiflorum Lam.) At Low Temperature, Siran Wang, Mudasir Nazar, Niaz Ali Kaka

IGC Proceedings (1977-2023)

Temperature is an important factor affecting ensilage. In cold regions, low temperature could be an adverse environmental factor during ensiling. However, little research has focused on improving silage quality at low temperatures. This study aimed to examine two lactic acid bacteria (LAB) strains (LCG9 and TG1) isolated from the Tibetan Plateau, and evaluate their effects on the silage quality of Italian ryegrass (Lolium multiflorum Lam.) at three temperatures (10° C, 15° C and 25° C). The isolated strains and one commercial inoculant (G, Lactobacillus plantarum MTD-1) were evaluated by morphological, physiological and biochemical tests. Strains G, LCG9, TG1 and …

It Takes More Than Calcium To Neutralize Soil Acidity, Edwin L. Ritchey, Christopher D. Teutsch, John H. Grove

IGC Proceedings (1977-2023)

Proper pH management is the foundation to a good soil fertility program. Soil pH influences nutrient availability and root growth and function. Just because an agricultural product contains calcium does not mean that it will change soil pH. The effectiveness of three calcium products in raising soil pH was compared to an untreated check in acid soils. A field trial was conducted at 16 locations across Kentucky and a laboratory incubation study was conducted at the University of Kentucky Research and Education Center. The same application rates were used for the three products, whether in field trials or laboratory incubations. …

A Novel Tractor Operated Grass Seed Harvester Developed In India, Chandra Shekhar Sahay, D. S. Thorat, P. S. Pathak

IGC Proceedings (1977-2023)

The demand of green and dry fodder in India is estimated to increase to 1170 and 650 m tonne whereas availability is expected to be at 411.3 and 488 m tonne in 2025, respectively, depicting deficit of about 64.9% green fodder and 24.9% dry fodder (Vision 2030, ICAR - IGFRI, Jhansi, 2011). In forages, availability of quality seed is only 25-30% in cultivated fodder and less than 10 % in range grasses and legumes (Vision 2050, IGFRI). Prices paid for grass seeds of native species vary from Rs.5,000 to 6,500 per kg for clean, un-haired seeds due to excessive use …

Making Round Bale Silage – Lessons Learned From An On-Farm Survey Of Baleage In Kentucky, Jimmy C. Henning, Jeff Lehmkuhler, Brandon Sears, Corinne Belton, L. Berg, Don Sorrell, April Wilhoit

IGC Proceedings (1977-2023)

The ability to make silage in round bale packages allows producers to avoid rain damage and produce high quality stored forage. The proliferation of bale wrappers (both individual and inline types) has made this technology more available to producers. Although the process for making baleage is well documented, producers have experienced poor fermentation and in some cases botulism toxicity from baleage. The parameters of good silage are well known and include pH below 5.0 and lactic acid concentrations above 3% on a DM basis. However, tests of farmer- produced baleage reveals that often these target values are not achieved. To …

Yellotas: A Unique Yellow Serradella Cultivar With Potential For Permanent Pasture Environments, G. Martin, Rowan W. Smith, E. J. Hall, Matthew Newell, R. Haling, R. C. Hayes

IGC Proceedings (1977-2023)

Yellow serradella (Ornithopus compressus L.) has been identified as a priority self-regenerating annual legume species for permanent pasture environments in south-eastern Australia. However, most yellow serradella genotypes exhibit high levels of hard seed and slow rates of hard seed breakdown, which reduces regeneration density in the years following the year of sowing . One cultivar, Yellotas, exhibits a much faster rate of hard seed breakdown and has been identified as one of only a handful of cultivars of that species with promising persistence in permanent pasture environments. In addition, this cultivar is substantially easier to de-hull than other cultivars …

Growth Components And Yield Of Brachiaria Ruziziensis (Congo Grass) And Centrosema Pascuorum (Centro) Mixtures As Influenced By Mixture Ratios, Phosphorus Levels And Stage Of Harvest, I. Sani, J. T. Amodu, R. J. Tanko, M. R. Hassan, N. Adamu

IGC Proceedings (1977-2023)

This study was conducted during the 2017 and 2018 rainy season at the Crop Production Research farm, Abubakar Tafawa Balewa University, Bauchi to determine the effects of plant mixture ratios in Brachiaria ruziziensis and Centrosema pascuorum (100% Sole B. ruziziensis, 75% B.R: 25% C.P, 50% B.R: 50% C.P, 25% B.R: 75% C.P and 100% Sole C. pascuorum) and phosphorus fertilizer (SSP) levels (0, 100 and 150kg/ha). The experiment was in a split-plot design with 5x3 factorial arrangement in which the mixture ratios constituted the main plots while phosphorus (SSP) levels constituted the sub treatments. Number of plants per …

A Solution To Weed Control In Grassland Containing White Clover, E. Bardsley, T. Schulz, R. Bentley, V. Van Damme, D. Gurney, N. Blanchier, B. B. Sleugh

IGC Proceedings (1977-2023)

Productive grass with white clover can lead to advantages both in forage quantity and quality, economics and in meeting wider expectations detailed in recent EU and UK policy. The ability to achieve this agronomic success is currently difficult due to a lack of options for broad spectrum weed control that also allow establishment or preservation of a white clover population. The aim of this paper is to demonstrate that 3730XL, developed by Corteva Agriscience, is a solution to this critical success factor. Data is presented from 16 efficacy trials (10 from established grassland and 5 from newly sown) where white …

Climate Change And Legume Performance In Grassland Agroecosystems, Lynn E. Sollenberger, M. M. Kohmann

IGC Proceedings (1977-2023)

We reviewed the literature to assess the effect of climate change factors on forage legumes. Whether growing in monoculture or mixtures with grasses, exposing legumes to elevated CO₂ (eCO₂) generally leads to sustained increases in forage accumulation (FA) and N fixation, but elevated temperature (eT) in conjunction with eCO₂ usually reduces magnitude of these responses. In legumes, nodules represent large C sinks, precluding photosynthetic acclimation to eCO₂ observed in non-N fixing plants. Greater N fixation in legume-grass mixtures exposed to eCO₂ is due to greater percentage of legume N derived from symbiotic fixation and …