Open Access. Powered by Scholars. Published by Universities.®
- Institution
-
- University of Kentucky (9522)
- University of Nebraska - Lincoln (1408)
- University of South Florida (620)
- Utah State University (606)
- University of Texas Rio Grande Valley (436)
-
- Old Dominion University (339)
- University of Arkansas, Fayetteville (293)
- Department of Primary Industries and Regional Development, Western Australia (266)
- Western Kentucky University (174)
- University of Nevada, Las Vegas (142)
- Portland State University (140)
- Boise State University (129)
- University of New Hampshire (128)
- Montclair State University (125)
- University of South Carolina (110)
- City University of New York (CUNY) (107)
- TÜBİTAK (107)
- Louisiana State University (105)
- Western Michigan University (98)
- South Dakota State University (93)
- University of Dar es Salaam (86)
- Missouri University of Science and Technology (84)
- University of Colorado Law School (84)
- The University of Southern Mississippi (78)
- University of North Dakota (74)
- Wright State University (71)
- University of Texas at El Paso (68)
- Chapman University (62)
- Universitas Padjadjaran (61)
- China Coal Technology and Engineering Group (CCTEG) (60)
- Keyword
-
- Grazing (393)
- Nitrogen (272)
- Climate change (237)
- Alfalfa (203)
- Soil (187)
-
- Grassland (174)
- Biodiversity (167)
- Sheep (167)
- Forage (164)
- Phosphorus (164)
- Western Australia (164)
- Pasture (159)
- Cattle (156)
- Water quality (154)
- Digestibility (146)
- Yield (141)
- Forage quality (137)
- Silage (137)
- Sustainability (126)
- Remote sensing (122)
- Legumes (120)
- Nutritive value (120)
- Groundwater (119)
- Hydrology (118)
- Geology (115)
- Stocking rate (115)
- Trifolium repens (113)
- Intake (112)
- Management (112)
- Drought (109)
- Publication Year
- Publication
-
- IGC Proceedings (1977-2023) (9261)
- United States Geological Survey: Staff Publications (519)
- School of Earth, Environmental, & Marine Sciences Faculty Publications (371)
- International Journal of Speleology (339)
- Memorandum (315)
-
- Theses and Dissertations (247)
- Faculty Publications (214)
- Department of Earth and Atmospheric Sciences: Faculty Publications (184)
- OES Faculty Publications (158)
- Electronic Theses and Dissertations (147)
- Graduate Theses and Dissertations (146)
- All Graduate Theses and Dissertations, Spring 1920 to Summer 2023 (121)
- School of Natural Resources: Dissertations, Theses, and Student Research (118)
- Bulletin of the University of Nebraska State Museum (1924–2023) (112)
- USF Tampa Graduate Theses and Dissertations (110)
- Masters Theses (109)
- Turkish Journal of Earth Sciences (107)
- School of Geosciences Faculty and Staff Publications (98)
- Tanzania Journal of Science (86)
- Department of Earth and Environmental Studies Faculty Scholarship and Creative Works (83)
- Geosciences Faculty Publications and Presentations (79)
- OES Theses and Dissertations (77)
- United States Geological Survey: Publications (69)
- Open Access Theses & Dissertations (65)
- Master's Theses (64)
- Masters Theses & Specialist Projects (64)
- Journal of the Arkansas Academy of Science (63)
- United States Environmental Protection Agency: Publications (63)
- Jurnal Kultivasi (61)
- Coal Geology & Exploration (60)
- Publication Type
- File Type
Articles 12391 - 12420 of 17799
Full-Text Articles in Entire DC Network
Indoor Radon Concentration Levels And Annual Effective Doses For Residence Of Houses Near Uranium Deposit In Bahi District, Dodoma, Tanzania, Najat K. Mohammed, Erasto Focus
Indoor Radon Concentration Levels And Annual Effective Doses For Residence Of Houses Near Uranium Deposit In Bahi District, Dodoma, Tanzania, Najat K. Mohammed, Erasto Focus
Tanzania Journal of Science
The objective of this study was to determine the levels of indoor radon concentration in houses in Bahi District situated in the neighbourhood of uranium deposit. The study aimed also to assess the annual effective dose due to indoor radon exposure to individuals residing in the houses as a step to control the radon exposure in Tanzania. Two villages were involved in this study; Bahi Makulu, which is within the proximity of Uranium deposit and Bahi Sokoni, which is about 7 km from the deposit. The Indoor radon concentration levels were detected using Alpha Guard radon monitor and the obtained …
Assessment Of Indoor Radon-222 Concentrations In The Vicinity Of Manyoni Uranium Deposit, Singida, Germana W Mlay, Ismael N Makundi
Assessment Of Indoor Radon-222 Concentrations In The Vicinity Of Manyoni Uranium Deposit, Singida, Germana W Mlay, Ismael N Makundi
Tanzania Journal of Science
This study aimed to assess indoor radon concentrations in the vicinity of the Manyoni Uranium Deposit in Singida. The concentrations were measured for two months in 32 houses in the vicinity of Manyoni Uranium Deposit and 9 houses at Manyoni town using a portable radon gas monitor (Alpha –GUARDTM). The radon concentrations ranged from 27±3 to 518±28 Bq/m3with the overall mean of 166±12 Bq/m3 which is above recommended values of 100 Bq/m3 and 148 Bq/m3 set by WHO (World Health Organization) and EPA (Environmental Protection Agency's), respectively. The overall mean of indoor radon concentrations from each village were Kipondoda (169±13 …
Petrographic And Stratigraphic Analysis Along The Lower Cretaceous Strata, In Kimble County Texas, Austin C. Wilkerson
Petrographic And Stratigraphic Analysis Along The Lower Cretaceous Strata, In Kimble County Texas, Austin C. Wilkerson
Student Publications
The upper Trinity Group is predominantly a carbonate system with minor clastic couplets that were deposited during the Middle Cretaceous in the south Llano Uplift region. The upper Trinity Group was deposited on a southward dipping platform in the Kimble County area. Stratigraphic units of the upper Trinity Group are the Hensel Formation, determined to be supratidal claystones, the Glen Rose Formation, which are mudstones that were deposited in a carbonate lagoon, and the Walnut and Fort Terrett formations, which are wackestones to packstones interpreted to have been deposited on a shallow carbonate shelf.
Nine stratigraphic sections were measured along …
Cyanobacteria Reduce Quagga Mussel (Dreissena Rostriformis Bugensis) Spawning And Fertilization Success, Anna G. Boegehold, Nicholas S. Johnson, Jeffrey L. Ram, Donna R. Kashian
Cyanobacteria Reduce Quagga Mussel (Dreissena Rostriformis Bugensis) Spawning And Fertilization Success, Anna G. Boegehold, Nicholas S. Johnson, Jeffrey L. Ram, Donna R. Kashian
Environmental Science and Geology Faculty Research Publications
Quagga mussels (Dreissena rostriformis bugensis) are highly fecund broadcast spawners invasive to freshwaters of North America and western Europe. We hypothesized that environmental cues from phytoplankton can trigger gamete release in quagga mussels. Nutritious algae may stimulate dreissenid spawning, but less palatable food, such as bloom-forming cyanobacteria, could be a hindrance. The objective of our study was to test whether exposure to cyanobacteria can inhibit quagga mussel spawning and fertilization. We assessed spawning in the presence of serotonin, a known spawning inducer, where adult quagga mussels placed in individual vials were exposed to 13 cyanobacteria cultures and purified algal toxin …
Quantifying Factors That Influence Road Deicer Retention And Export In A Multi-Landuse Upstate New York Watershed, David Joseph Saba
Quantifying Factors That Influence Road Deicer Retention And Export In A Multi-Landuse Upstate New York Watershed, David Joseph Saba
Graduate Dissertations and Theses
Chloride contamination of streams and groundwater has become a prevalent issue throughout urbanizing areas in the last half century, particularly in northern latitudes where deicing salts are applied to roadways. This study determined how deicer impacted runoff disperses through sub-urban and urban areas on seasonal and multi-year scales. Chloride concentration changes were then modelled under varying pollutant loading scenarios through an integrated catchment model (INCA-Cl).
Six in-stream conductivity/stage/temperature sondes, recording at 15-minute intervals, were installed within the small (~9.6 km2) Fuler Hollow Creek multi-landuse watershed in Broome County NY and monitored over a 1-year period. Weekly grab samples were taken …
Petrographic And Stratigraphic Analysis Along The Lower Cretaceous Strata, In Kimble County Texas, Austin C. Wilkerson
Petrographic And Stratigraphic Analysis Along The Lower Cretaceous Strata, In Kimble County Texas, Austin C. Wilkerson
Electronic Theses and Dissertations
The upper Trinity Group is predominantly a carbonate system with minor clastic couplets that were deposited during the Middle Cretaceous in the south Llano Uplift region. The upper Trinity Group was deposited on a southward dipping platform in the Kimble County area. Stratigraphic units of the upper Trinity Group are the Hensel Formation, determined to be supratidal claystones, the Glen Rose Formation, which are mudstones that were deposited in a carbonate lagoon, and the Walnut and Fort Terrett formations, which are wackestones to packstones interpreted to have been deposited on a shallow carbonate shelf.
Nine stratigraphic sections were measured along …
New Geochemical And Isotopic Approaches To Shallow Crust Landform Evolution, David Decker
New Geochemical And Isotopic Approaches To Shallow Crust Landform Evolution, David Decker
Earth and Planetary Sciences ETDs
Many researchers have studied the Guadalupe Mountains in detail and starting with King (1948), many of them have speculated about the timing of the uplift of the Guadalupe block. There are several competing hypotheses including Laramide, Basin and Range, and Rio Grande Rifting uplift scenarios. Using uranium-lead dating of scalenohedral spar found in small vug caves throughout the study area, I have dated the episodes of spar formation to two major phases, 36 to 33 Ma and 30 to 27 Ma. These two episodes of spar formation are in good agreement with the time frame of the ignimbrite flare up …
Analysis Of Surface Soil Lead Contamination In Urban Neighborhoods Of Davenport, Ia, Joseph Teresi
Analysis Of Surface Soil Lead Contamination In Urban Neighborhoods Of Davenport, Ia, Joseph Teresi
Geology: Student Scholarship & Creative Works
Davenport, IA, is a typical Midwestern city with a population of ~102,600 residents and is characterized by aging infrastructure and housing stock. Consequently, alarmingly high rates of child lead poisoning—as a result of deteriorating lead paint—constitute a major public health concern in some urban neighborhoods. Augustana College’s Upper Mississippi Center is an organization that helps urban and rural communities solve sustainability challenges by mobilizing the college’s resources. In conjunction with their Sustainable Working Landscapes Initiative (SWLI), a research team conducted free home lead screenings in vulnerable Davenport neighborhoods to better understand the severity of the problem. Via appointment, 27 homes …
Adam J. Liska: Curriculum Vitae, Adam Liska
Adam J. Liska: Curriculum Vitae, Adam Liska
Adam Liska Papers
Associate Professor, George Dempster Smith Chair of Industrial Ecology, Departments of Biological Systems Engineering and Agronomy & Horticulture, University of Nebraska-Lincoln 236 L.W. Chase Hall, Lincoln, NE 68583-0726, Ph: (402) 472-8744, e-mail: [email protected]
Ph.D. 2003 Biology (magna cum laude), Max Planck Institute of Molecular Cell Biology & Genetics, Technische Universität Dresden, Dresden, Germany
Correlation Between Agricultural Land Cover And Groundwater Nitrate Contamination In Big Bat Cave, Kentucky., Brandt T. Coleman
Correlation Between Agricultural Land Cover And Groundwater Nitrate Contamination In Big Bat Cave, Kentucky., Brandt T. Coleman
College of Arts & Sciences Senior Theses
No abstract provided.
Regional Stratigraphy And Distribution Of The Coastal Group, St. Elizabeth Parish, Southwestern Jamaica, Brett M. Kenning
Regional Stratigraphy And Distribution Of The Coastal Group, St. Elizabeth Parish, Southwestern Jamaica, Brett M. Kenning
Graduate Theses/Dissertations
This contribution examines the characteristics and ages of sedimentary units in the Coastal Group located along the southwestern Jamaica coast between Great Pedro Bluff and Fort Charles Bay in southwestern St. Elizabeth Parish. The coastline is characterized by laterally discontinuous low cliff exposures, separated by modern beach deposits and tectonically raised shore platforms composed of the White Limestone Group (mid-Eocene to mid-Miocene) and coral rudstone to floatstone and calcareous sandstone of the Coastal Group (late Pleistocene). Electron-Spin Resonance spectroscopy conducted on corals collected from a coral rudstone to floatstone facies yielded an estimated age of 120 ka. The coral facies …
Benefits And Obstacles To Installing Wind And Solar Energy Systems On University Campuses: A Texas Study, Andrew G. Lafavers
Benefits And Obstacles To Installing Wind And Solar Energy Systems On University Campuses: A Texas Study, Andrew G. Lafavers
Earth & Environmental Sciences Dissertations - Archive
There is much known about renewable energy including solar and wind. However, there is little information available regarding the use of wind and solar energy on college and university campuses. As educators and shapers of the next generation of society, colleges and universities can be important leaders in the transitioning to renewable energy, and in educating their students about renewable energy. In addition, college and university campuses are in an economic downfall now, with the high costs of education and decreased state funding. Institutions of higher education must find ways to save money and decrease costs; utility bills could potentially …
Comparison Of Cultivation Methods Impact On Playability Of Agrostis Stolonifera Greens, K. Dickson, J. Sorochan, Gregg Munshaw, A. Thomas
Comparison Of Cultivation Methods Impact On Playability Of Agrostis Stolonifera Greens, K. Dickson, J. Sorochan, Gregg Munshaw, A. Thomas
Plant and Soil Sciences Faculty Publications
Creeping bentrgrass putting greens require intense management due to stoloniferous growth (thatch accumulation) and excessive wear and traffic by equipment and golfers. Increases in thatch and soil compaction are often managed with cultivation practices, which lead to downtime for golfers. Field research was conducted in Knoxville, TN, and Elizabethtown, KY, to compare new and traditional cultivation methods for their impact on playability on creeping bentgrass putting greens. Treatments included air injection, dry sand injection, solid tine cultivation topdressed with sand, hollow tine cultivation topdressed with sand, and non-treated control. Treatments were arranged in a randomized complete block design replicated three …
Characterization Of Metamorphic Zones In The Tennessee Blue Ridge Using Gis And Digital Imaging Processing, Hayley Beitel
Characterization Of Metamorphic Zones In The Tennessee Blue Ridge Using Gis And Digital Imaging Processing, Hayley Beitel
Honors Theses
The origin of metamorphic zones of the Blue Ridge is attributed to metamorphic events that affected sedimentary rocks of debated age, leading the topic to be controversial and continuously studied. The present study seeks to refine the metamorphic isograds of the Tennessee Blue Ridge based on Barrovian index minerals in pelitic rocks and the texture patterns these pelitic rocks present. Methods used in the present study are supported by conventional petrography, powder X-ray diffraction, and by GIS and digital image processing. Metamorphic isograds in the Blue Ridge have been determined mainly by identification of index minerals using a polarizing petrographic …
Spatial Analysis Of Air Particulate Pollution Distributions And Its Relation To Real Property Value In Beijing, China, Yingyu Zhang
Spatial Analysis Of Air Particulate Pollution Distributions And Its Relation To Real Property Value In Beijing, China, Yingyu Zhang
Great Lakes Center Masters Theses
Air particulate pollution contributes the major air pollution in Beijing, China. In this research, concentrations of air particulate pollutants were measured at a total of twenty-three field locations in the urban districts of Beijing applying a laser particle counter in June and December 2015. Geographic Information System (GIS) was utilized to study the two and three-dimensional spatial distributions of air particulate pollution (PM0.5, PM1.0, PM2.5, PM5.0, PM10). Geostatistical or spatial statistical models were applied to interpolate the spatial distributions of air particulate pollution and real property values in the study area. Geographically Weighted Regression (GWR) was applied to analyze the …
Nitrous Oxide Emissions From Rice Production On A Silt-Loam Soil In Arkansas, Casey Rector
Nitrous Oxide Emissions From Rice Production On A Silt-Loam Soil In Arkansas, Casey Rector
Graduate Theses and Dissertations
Rice (Oryza sativa L.) is a common crop grown in Arkansas under flooded-soil conditions. The saturated to nearly saturated soil makes rice production an ideal environment for the production of potent greenhouse gases, such as nitrous oxide (N2O). The objectives of this study were to i) evaluate the impact of water management practice (full-season-flood and intermittent-flood) and cultivar (pure-line and hybrid) on N2O fluxes, season-long N2O emissions, and global warming potential (GWP; 2016) and ii) evaluate the impact of tillage practice [conventional tillage and no-tillage (NT)] and type of urea fertilizer [ N-(n-butyl) thiosphosphoric triamide (NBPT)-coated and non-coated urea] on …
Applications Of Reservoir Limnology Theory And Steady-State Modeling To Eutrophication Management In Beaver Lake, Arkansas, Matthew Rich
Applications Of Reservoir Limnology Theory And Steady-State Modeling To Eutrophication Management In Beaver Lake, Arkansas, Matthew Rich
Graduate Theses and Dissertations
Reservoir limnology theory predicts that phytoplankton biomass (PB) is greatest in riverine-transition zones and least in lacustrine zones leading to an inverse pattern in water clarity. These theoretical patterns were utilized to create a statistical model of chlorophyll-a (Chl-a), an indicator of PB, and Secchi transparency (ST), an indicator of Chl-a, in Beaver Lake, Arkansas, a 12,800-ha reservoir, in order to hindcast historical conditions. Sampling for Chl-a, ST, and photic depth occurred semimonthly at 12 locations along a 78-km transect from the river inflow to the dam during the 2015 growing season. The ratio of Chl-a and ST measured at …
Prospecting For Coal Bed Uranium In Kansas Through The Use Of Arcgis And Uranium Proxies, Logan Howell
Prospecting For Coal Bed Uranium In Kansas Through The Use Of Arcgis And Uranium Proxies, Logan Howell
Master's Theses or Doctor of Nursing Practice
The potential implications for the discovery of coal bed uranium in Kansas not only have a significant scientific and human health interest impact, but also a possible future economic one as well. This study sought to look for coal bed uranium within the Cretaceous Dakota Formation located in north-central of Kansas. This study utilized the two coal bed uranium proxies of historic subbituminous coal production and radon, and ArcGIS to produce a field-site selection map. This map was used to pick counties within Kansas to collect samples from. Once samples were collected, they were scanned for radiation using all available …
Potential For Developing Run-Of-River Systems In Eastern Kentucky : A Gis Approach To Site Suitability., Thomas Jeffords
Potential For Developing Run-Of-River Systems In Eastern Kentucky : A Gis Approach To Site Suitability., Thomas Jeffords
Electronic Theses and Dissertations
Coal has a questionable future with the potential exhaustion of available coal. Alternate sources of energy production should be considered, such as hydropower dams, or the more environmentally friendly, Run of River (RoR) hydropower system. This study seeks to answer the question: What is the potential for RoR hydroelectric systems in Eastern Kentucky counties with significant decreases in coal production and employment? I hypothesize that GIS will identify suitable sites within Pike County for RoR systems. Site suitability for Eastern Kentucky was assessed and determined that Pike County did not have a suitable physical environment for RoR systems. The power …
Nebraska Wetland Condition Assessment: Intensification Of The National Wetland Condition Assessment Throughout Nebraska, Cody Dreier
School of Natural Resources: Dissertations, Theses, and Student Research
Even though wetlands provide a habitat for many plants and animals and numerous services for humans, they were not always treated as areas of value. Less than half of the United States’ pre-colonial wetlands have survived to the present day. Seeing a need to understand the remaining wetlands more fully, the Environmental Protection Agency developed the National Wetland Condition Assessment to monitor target wetlands throughout the country every five years.
This study is an intensification of the National Wetland Condition Assessment for Nebraska wetlands that allowed us to sample more areas of the state and gather additional information. During the …
Investigating Mechanisms Of Hydraulic Conductivity Transience In Sandy Streambeds, Wilhelm Fraundorfer
Investigating Mechanisms Of Hydraulic Conductivity Transience In Sandy Streambeds, Wilhelm Fraundorfer
School of Natural Resources: Dissertations, Theses, and Student Research
Streambed hydraulic conductivity (K) is known to be spatially and temporally heterogeneous, but few attempts to understand the controls on temporal variability have been made. This study documents temporal K transience and demonstrates how hydraulic, geophysical, and sedimentological methods can be combined to understand the processes that give rise to changes in streambed K. Falling head permeameter tests and slug tests were conducted to determine vertical K (Kv) and K (slug test K), respectively. These tests were repeated three times over a twelve-week period on the same grid at a depth of 0.5 …
Chemical And Statistical Analysis Of Karst Groundwater Basin Signatures - Springfield, Mo, Benjamin E. Lockwood
Chemical And Statistical Analysis Of Karst Groundwater Basin Signatures - Springfield, Mo, Benjamin E. Lockwood
Graduate Theses/Dissertations
Springfield, MO is located on the Springfield Plateau physiographic province. The Springfield plateau contains a number of Mississippian aged units and is mainly capped by the Burlington-Keokuk Formation. The Burlington-Keokuk is a highly fossiliferous limestone with nodular and interbedded chert. Beneath the Burlington-Keokuk lies the Elsey, Reeds Spring, and Pierson Formations respectively which comprise the Springfield Plateau aquifer hydrostratigraphic unit. Within the Springfield Plateau aquifer, a well-developed karst system includes springs, sinkholes, and caves. The Springfield Plateau aquifer is the predominant source for springs and seeps in the Springfield area. The purpose of this study was to understand the differences …
Geochemical Dynamics And Nitrous Oxide Release From The Hyporheic Zone Of Streams, Annika Marie Quick
Geochemical Dynamics And Nitrous Oxide Release From The Hyporheic Zone Of Streams, Annika Marie Quick
Boise State University Theses and Dissertations
The hyporheic zones of streams and rivers, consisting of the sediments beneath and immediately adjacent to the stream channel, are an important site of geochemical processing. Due to the difficulty of measuring these geochemical processes in the hyporheic zone in situ with meaningful spatial and temporal resolution, we conducted multiple column and large-scale flume experiments to model 1D and 2D hyporheic flow paths and observed important geochemical reactions, including the production and consumption of nitrous oxide (N2O). N2O is a significant greenhouse gas, but the controls on its emissions from streams are poorly constrained. We describe …
Understanding The Late Mesoproterozoic Earth System From The Oldest Strata In Grand Canyon: C-Isotope Stratigraphy And Facies Analysis Of The 1254 Ma Bass Formation, Grand Canyon Supergroup, Az., Usa, Erin C. Lathrop
All Graduate Theses and Dissertations, Spring 1920 to Summer 2023
Rocks provide insight into ancient times before complex animals existed. The oldest sedimentary rocks in Grand Canyon (the Bass Formation) allow us to glimpse into what things might have been like over a billion years ago. These rocks record the time known as the Mesoproterozoic Era (1.6 to 1.0 billion years ago), otherwise known as the ‘boring billion’. These rocks are thought to be the right age to indicate the end of an oddly stable world when continents were quiet and life was calm, yet they predate younger rocks that record extreme events. The Bass Formation, some of the only …
Spatial And Temporal Trends In Diet For Pinfish (Lagodon Rhomboides) From Turtle Grass (Thalassia Testudinum) Beds With Contrasting Environmental Regimes In The Lower Laguna Madre, Texas, Maximiliano Barbosa
Spatial And Temporal Trends In Diet For Pinfish (Lagodon Rhomboides) From Turtle Grass (Thalassia Testudinum) Beds With Contrasting Environmental Regimes In The Lower Laguna Madre, Texas, Maximiliano Barbosa
Theses and Dissertations
Seagrass meadows in far South Texas are dominated by turtle grass (Thalassia testudinum), and juvenile pinfish (Lagodon rhomboides) are abundant grazers of seagrass epifauna. As they grow, pinfish exhibit an ontogenetic dietary shift and begin consuming increasing amounts of plant material. In this study, contrasting environmental regimes in two seagrass meadows were examined to identify how they might affect pinfish diets, diet shifts, and growth across the growing season. The eastern site was sheltered from prevailing southeasterly winds by a barrier island, while the western site was shallower and subjected to higher wind energy and turbidity. …
Postcranial Morphology And The Locomotor Adaptations Of Extant And Extinct Crocodylomorphs And Lepidosaurs, Laura Rooney
Postcranial Morphology And The Locomotor Adaptations Of Extant And Extinct Crocodylomorphs And Lepidosaurs, Laura Rooney
Electronic Theses and Dissertations
I have collected a series of linear measurements of the postcranial skeletons of 43 extant crocodylian and lepidosaur taxa to determine if those engaging in similar locomotor behavior display similar morphology despite phylogenetic differences. Stepwise discriminant function analyses reveal reptile locomotor mode can be accurately predicted (over 80% correct) based on morphology. Semi-aquatic taxa are distinguished by a longer ischium relative to pubis length, a longer scapula relative to humerus length, and a broader acetabulum than terrestrial and arboreal taxa. Arboreal taxa display a more elongate, gracile humerus and a smaller acetabulum. This morphometric data can potentially be used to …
Outbreak And Extinction Dynamics In Stochastic Populations, Garrett T. Nieddu
Outbreak And Extinction Dynamics In Stochastic Populations, Garrett T. Nieddu
Theses, Dissertations and Culminating Projects
Each piece of work herein examines nonlinear population dynamics using methods from deterministic dynamical systems, stochastic processes and statistical mechanics. This dissertation is the compilation of three independent – but related – pieces of work: the first investigates an isolated population that is capable of maintaining multiple carrying capacities; the second project examines a stochastic Ebola model with a zoonotic disease reservoir; and the third looks at a basic disease-invasion model to characterize outbreak vulnerability and the connectedness of supposedly separate populations.
Each of these three chapters explore the interplay between interconnected systems, without explicitly modeling the elements that are …
Soil Properties That Influence The Occurrence Of Hydrogen Sulfide Toxicity In Rice Fields, Julia Marie Fryer
Soil Properties That Influence The Occurrence Of Hydrogen Sulfide Toxicity In Rice Fields, Julia Marie Fryer
Graduate Theses and Dissertations
Rice (Oryza sativa L.) producers face many challenges throughout each growing season. Hydrogen sulfide (H2S) toxicity is a physiological disorder where sulfate (SO42-) is excessively reduced to the toxic gas, H2S. This can reduce yield and, in severe cases, result in crop death. The main research objectives were to: i) understand chemical and physical characteristics in soils prone to H2S toxicity, ii) determine influential soil characteristics on the incidence of H2S toxicity, iii) determine ammonium sulfate ((NH4)2SO4) fertilizer additions influence on H2S toxicity, and iv) predict when and where H2S will occur. Three greenhouse experiments were conducted using Arkansas field …
Extraction Of Metazoan Meiofauna From Muddy Deep-Sea Samples: Operator And Taxon Effects On Efficiency, Melissa Rohal, David Thistle, Erin E. Easton
Extraction Of Metazoan Meiofauna From Muddy Deep-Sea Samples: Operator And Taxon Effects On Efficiency, Melissa Rohal, David Thistle, Erin E. Easton
School of Earth, Environmental, & Marine Sciences Faculty Publications
Deep-sea metazoan meiofaunal specimens are usually extracted from muddy samples by centrifugation in a fluid in which meiofauna tend to float and sediment particles tend to sink. Although the procedure is in common use, its efficiency has seldom been examined. The study reported here showed that well-trained operators extracted metazoan meiofauna with efficiencies that were different enough to be a concern in quantitative studies. Therefore, samples should be assigned to operators in a stratified-random manner. In the course of these studies, both operators also extracted individuals of the common nematode family Desmoscolecidae significantly less efficiently than other nematode families, a …
Advancing The Understanding Of Environmental Transformations, Bioavailability And Effects Of Nanomaterials, An International Us Environmental Protection Agency—Uk Environmental Nanoscience Initiative Joint Program, Mitch M. Lasat, Kian Fan Chung, Jamie Lead, Steve Mcgrath, Richard J. Owen, Sophie Rocks, Jason M. Unrine, Junfeng Zhang
Advancing The Understanding Of Environmental Transformations, Bioavailability And Effects Of Nanomaterials, An International Us Environmental Protection Agency—Uk Environmental Nanoscience Initiative Joint Program, Mitch M. Lasat, Kian Fan Chung, Jamie Lead, Steve Mcgrath, Richard J. Owen, Sophie Rocks, Jason M. Unrine, Junfeng Zhang
Plant and Soil Sciences Faculty Publications
Nanotechnology has significant economic, health, and environmental benefits, including renewable energy and innovative environmental solutions. Manufactured nanoparticles have been incorporated into new materials and products because of their novel or enhanced properties. These very same properties also have prompted concerns about the potential environmental and human health hazard and risk posed by the manufactured nanomaterials. Appropriate risk management responses require the development of models capable of predicting the environmental and human health effects of the nanomaterials. Development of predictive models has been hampered by a lack of information concerning the environmental fate, behavior and effects of manufactured nanoparticles. The United …