Open Access. Powered by Scholars. Published by Universities.®

Physical Sciences and Mathematics Commons™

Open Access. Powered by Scholars. Published by Universities.®

2016

Discipline
Institution
Keyword
Publication
Publication Type
File Type

Articles 541 - 570 of 10866

Full-Text Articles in Physical Sciences and Mathematics

Food And Energy For All, Bradley Stevens, Stephen Rybczynski, Deborah Herrington Dec 2016

Food And Energy For All, Bradley Stevens, Stephen Rybczynski, Deborah Herrington

Peer Reviewed Articles

When asked what plants need for photosynthesis, many students can correctly recall the reaction equation and state that plants require CO2, H2O, and light. Many students, however, do not understand that these reactants are the raw materials plants use to make sugars and instead believe that they are food for plants. Moreover, when questioned further, students often voice the idea that plants get their food from the soil (Kestler 2014). This is consistent with findings that fewer than half of current middle and high school students have a correct understanding of the process of photosynthesis (AAAS 2015). We developed this …


Inequalities Of Hardy-Littlewood-Polya Type For Functions Of Operators And Their Applications, Vladyslav Babenko, Yuliya Babenko, Nadiia Kriachko Dec 2016

Inequalities Of Hardy-Littlewood-Polya Type For Functions Of Operators And Their Applications, Vladyslav Babenko, Yuliya Babenko, Nadiia Kriachko

Faculty Articles

In this paper, we derive a generalized multiplicative Hardy-Littlewood-Polya type inequality, as well as several related additive inequalities, for functions of operators in Hilbert spaces. In addition, we find the modulus of continuity of a function of an operator on a class of elements defined with the help of another function of the operator. We then apply the results to solve the following problems: (i) the problem of approximating a function of an unbounded self-adjoint operator by bounded operators, (ii) the problem of best approximation of a certain class of elements from a Hilbert space by another class, and (iii) …


Land Use And Land Cover Based Habitat Analyses Of Invasive Species Along The Lower Tonawanda Creek Applying Unmanned Helicopter Remote Sensing, Chenliuli Jiang Dec 2016

Land Use And Land Cover Based Habitat Analyses Of Invasive Species Along The Lower Tonawanda Creek Applying Unmanned Helicopter Remote Sensing, Chenliuli Jiang

Great Lakes Center Masters Theses

Trapa natans (water chestnut) is an exotic annual aquatic plant, which is native to Eurasian and African continents. It is an invasive species in North America and has already caused serious environmental problems because of its strong capability of adaption and propagation. The objectives of this research were to survey and map water chestnut in the lower Tonawanda Creek (Erie Canal) applying unmanned aerial vehicle (UAV), evaluate the current management of controlling and removing water chestnut, and analyze how land use and land cover (LULC), as well as habitat conditions, influence the growth of water chestnut. The UAV was not …


Preliminary Investigation Of Walking Motion Using A Combination Of Image And Signal Processing, Bradley Schneider, Tanvi Banerjee Dec 2016

Preliminary Investigation Of Walking Motion Using A Combination Of Image And Signal Processing, Bradley Schneider, Tanvi Banerjee

Kno.e.sis Publications

We present the results of analyzing gait motion in first-person video taken from a commercially available wearable camera embedded in a pair of glasses. The video is analyzed with three different computer vision methods to extract motion vectors from different gait sequences from four individuals for comparison against a manually annotated ground truth dataset. Using a combination of signal processing and computer vision techniques, gait features are extracted to identify the walking pace of the individual wearing the camera as well as validated using the ground truth dataset. Our preliminary results indicate that the extraction of activity from the video …


Quiescent‐Explosive Transitions During Dome‐Forming Volcanic Eruptions: Using Seismicity To Probe The Volcanic Processes Leading To The 29 July 2008 Vulcanian Explosion Of Soufrière Hills Volcano, Montserrat, Mel Rodgers, Patrick J. Smith, Tamsin A. Mather, David M. Pyle Dec 2016

Quiescent‐Explosive Transitions During Dome‐Forming Volcanic Eruptions: Using Seismicity To Probe The Volcanic Processes Leading To The 29 July 2008 Vulcanian Explosion Of Soufrière Hills Volcano, Montserrat, Mel Rodgers, Patrick J. Smith, Tamsin A. Mather, David M. Pyle

School of Geosciences Faculty and Staff Publications

The July 2008 vulcanian explosion at Soufrière Hills Volcano (SHV), Montserrat, was preceded by one of the largest seismic swarms observed since the start of the eruption. We analyze the spectral and waveform properties of the earthquakes in this swarm and compare these observations to models of subsurface volcanic processes. We observe an initial volcano‐tectonic (VT) swarm, followed by a large low‐frequency (LF) swarm. We observe that the spectral content of LF events changes over time to carry more energy at lower frequencies. This shift to a lower frequency spectral content is concurrent with an increase in LF event rates. …


What’S Scale Got To Do With It? Models For Urban Tree Canopy, Dexter H. Locke, Shawn M. Landry, J. M. Grove, Rinku R. Chowdhury Dec 2016

What’S Scale Got To Do With It? Models For Urban Tree Canopy, Dexter H. Locke, Shawn M. Landry, J. M. Grove, Rinku R. Chowdhury

School of Geosciences Faculty and Staff Publications

The uneven provisioning of ecosystem services has important policy implications; yet the spatial heterogeneity of tree canopy remains understudied. Private residential lands are important to the future of Philadelphia’s urban forest because a majority of the existing and possible tree canopy is located on residential land uses. This article examines the spatial distribution of tree canopy in Philadelphia, PA and its social correlates. How are existing tree canopy and opportunities for additional tree canopy distributed across the city of Philadelphia and with respect to three explanations: (i) population density, (ii) the social stratification luxury effect, and 3) lifestyle characteristics of …


Greenland Subglacial Drainage Evolution Regulated By Weakly Connected Regions Of The Bed, Matthew J. Hoffman, Lauren C. Andrews, Stephen F. Price, Ginny A. Catania, Thomas A. Neumann, Martin P. Lüthi, Jason Gulley, Claudia Ryser, Robert L. Hawley, Blaine Morriss Dec 2016

Greenland Subglacial Drainage Evolution Regulated By Weakly Connected Regions Of The Bed, Matthew J. Hoffman, Lauren C. Andrews, Stephen F. Price, Ginny A. Catania, Thomas A. Neumann, Martin P. Lüthi, Jason Gulley, Claudia Ryser, Robert L. Hawley, Blaine Morriss

School of Geosciences Faculty and Staff Publications

Penetration of surface meltwater to the bed of the Greenland Ice Sheet each summer causes an initial increase in ice speed due to elevated basal water pressure, followed by slowdown in late summer that continues into fall and winter. While this seasonal pattern is commonly explained by an evolution of the subglacial drainage system from an inefficient distributed to efficient channelized configuration, mounting evidence indicates that subglacial channels are unable to explain important aspects of hydrodynamic coupling in late summer and fall. Here we use numerical models of subglacial drainage and ice flow to show that limited, gradual leakage of …


Precursor Motion To Iceberg Calving At Jakobshavn Isbræ, Greenland, Observed With Terrestrial Radar Interferometry, Surui Xie, Timothy H. Dixon, Denis Voytenko, David M. Holland, Tiantian Zheng Dec 2016

Precursor Motion To Iceberg Calving At Jakobshavn Isbræ, Greenland, Observed With Terrestrial Radar Interferometry, Surui Xie, Timothy H. Dixon, Denis Voytenko, David M. Holland, Tiantian Zheng

School of Geosciences Faculty and Staff Publications

Time-varying elevations near the calving front of Jakobshavn Isbræ, Greenland were observed with a terrestrial radar interferometer (TRI) in June 2015. An ice block with surface dimensions of 1370 m × 290 m calved on 10 June. TRI-generated time series show that ice elevation near the calving front began to increase 65 h prior to the event, and can be fit with a simple block rotation model. We hypothesize that subsurface melting at the base of the floating terminus breaks the gravity-buoyancy equilibrium, leading to slow subsidence and rotation of the block, and its eventual failure.


Decline In Methylmercury In Museum-Preserved Bivalves From San Francisco Bay, California, Allison C. Luengen, Heather M. Foslund, Ben K. Greenfield Dec 2016

Decline In Methylmercury In Museum-Preserved Bivalves From San Francisco Bay, California, Allison C. Luengen, Heather M. Foslund, Ben K. Greenfield

SIUE Faculty Research, Scholarship, and Creative Activity

There are ongoing efforts to manage mercury and nutrient pollution in San Francisco Bay (California, USA), but historical data on biological responses are limited. We used bivalves preserved in formalin or ethanol from museum collections to investigate long-term trends in methylmercury (MeHg) concentrations and carbon and ni- trogen isotopic signatures. In the southern reach of the estuary, South Bay, MeHg in the Asian date mussel (Musculista senhousia) significantly declined over the study duration (1970 to 2012). Mean MeHg concentrations were highest (218 ng/g dry weight, dw) in 1975 and declined 3.8-fold (to 57 ng/g dw) by 2012. This …


Gastrointestinal Health As A Stimulus For Native American Attraction To Medicinal Asteraceae And Further Implications For Human Evolution, Christopher David Stiegler Dec 2016

Gastrointestinal Health As A Stimulus For Native American Attraction To Medicinal Asteraceae And Further Implications For Human Evolution, Christopher David Stiegler

Graduate Theses and Dissertations

The Asteraceae, or the daisy family, is the largest family of flowering plants in the world, and its ethnobotanical, medical, and economic value is readily apparent cross-culturally. The aim of this thesis is to examine why constituent genera of the Aster family have remained such an integral part of human medicinal plant knowledge, and thereby to reveal any potential physiological, biological, or evolutionary mechanisms underlining human patterns of use regarding the Asteraceae. The present study focuses specifically on Native American plant knowledge made available by the expansive database in the works Daniel Moerman (Moerman 2003). Frequencies of plant use and …


Stratigraphy And Depositional Environment Of The Middle Atoka Formation, Central Arkoma Basin, Western Arkansas, Yueyang Wang Dec 2016

Stratigraphy And Depositional Environment Of The Middle Atoka Formation, Central Arkoma Basin, Western Arkansas, Yueyang Wang

Graduate Theses and Dissertations

Wire line logs are widely used in analysis of the subsurface stratigraphy of the middle Atoka Formation, Central Arkoma Basin, Western Arkansas. SP log, Gamma ray log, resistivity log and conductivity log provide valuable information to construct cross sections.

The middle Atoka formation is composed of a succession of shale and sandstone alternations with thickness reaching approximately 3000 feet in the study area. It contains several sandstone units which include Morris, Tackett, Areci, Bynum, Casey and Dunn”A” separated by shale intervals. The purpose of this study is to identify these units and predict sequence stratigraphy and depositional environment by constructing …


Effects Of Mars Regolith Analogs, Uvc Radiation, Temperature, Pressure, And Ph On The Growth And Survivability Of Methanogenic Archaea And Stable Carbon Isotope Fractionation: Implications For Surface And Subsurface Life On Mars, Navita Sinha Dec 2016

Effects Of Mars Regolith Analogs, Uvc Radiation, Temperature, Pressure, And Ph On The Growth And Survivability Of Methanogenic Archaea And Stable Carbon Isotope Fractionation: Implications For Surface And Subsurface Life On Mars, Navita Sinha

Graduate Theses and Dissertations

Mars is one of the suitable bodies in our solar system that can accommodate extraterrestrial life. The detection of plumes of methane in the Martian atmosphere, geochemical evidence, indication of flow of intermittent liquid water on the Martian surface, and geomorphologies of Mars have bolstered the plausibility of finding extant or evidence of extinct life on its surface and/or subsurface. However, contemporary Mars has been considered as an inhospitable planet for several reasons, such as low atmospheric surface pressure, low surface temperature, and intense DNA damaging radiation. Despite the hostile conditions of Mars, a few strains of methanogenic archaea have …


Temporal Co2 Variations And The Influence Of Bat Colonies In Speleogenesis: Continuous Co2 Monitoring In War Eagle Cavern, Arkansas, Ginny Sue Holcomb Dec 2016

Temporal Co2 Variations And The Influence Of Bat Colonies In Speleogenesis: Continuous Co2 Monitoring In War Eagle Cavern, Arkansas, Ginny Sue Holcomb

Graduate Theses and Dissertations

Dissolved concentrations of CO2 in a karst aquifer are a major control on calcite dissolutional processes, as CO2 combines chemically with water to form carbonic acid. As increasing amounts of CO2 are added to the system, greater resultant water aggressivity generates greater rates of dissolution. Spatial and temporal variations in carbon flux through the system may occur over a range of time scales, and high-resolution data collection is needed to truly understand and characterize such variability. Continuous CO2 monitoring in War Eagle Cavern, Arkansas, will suggest a number of influential parameters with varying degrees of importance throughout an annual cycle. …


Monte Carlo Methods In Bayesian Inference: Theory, Methods And Applications, Huarui Zhang Dec 2016

Monte Carlo Methods In Bayesian Inference: Theory, Methods And Applications, Huarui Zhang

Graduate Theses and Dissertations

Monte Carlo methods are becoming more and more popular in statistics due to the fast development of efficient computing technologies. One of the major beneficiaries of this advent is the field of Bayesian inference. The aim of this thesis is two-fold: (i) to explain the theory justifying the validity of the simulation-based schemes in a Bayesian setting (why they should work) and (ii) to apply them in several different types of data analysis that a statistician has to routinely encounter. In Chapter 1, I introduce key concepts in Bayesian statistics. Then we discuss Monte Carlo Simulation methods in detail. Our …


Fabrication Of Infrared Photodetectors Utilizing Lead Selenide Nanocrystals, Justin Anthony Hill Dec 2016

Fabrication Of Infrared Photodetectors Utilizing Lead Selenide Nanocrystals, Justin Anthony Hill

Graduate Theses and Dissertations

Colloidal lead selenide and lead selenide / lead sulfide core/shell nanocrystals were grown using a wet chemical synthesis procedure. Absorbance and photoluminescence measurements were made to verify the quality of the produced nanocrystals. Absorbance spectra were measured at room temperature, while photoluminescence spectra were measured at 77 K. Organic ligands were exchanged for shorter ligands in order to increase the conductivity of the nanocrystals. Absorption and PL spectra for both core and core/shell nanocrystals were compared. Interdigital photodetector devices with varying channel widths were fabricated by depositing gold onto a glass substrate. Lead selenide nanocrystals were deposited onto these metallic …


Discord And Global Discord In Systems Of Coupled Quantum Dots In Driven Cavities With Dissipation, And A Method For The Calculation Of Global Discord, Willa Danielle Rawlinson Dec 2016

Discord And Global Discord In Systems Of Coupled Quantum Dots In Driven Cavities With Dissipation, And A Method For The Calculation Of Global Discord, Willa Danielle Rawlinson

Graduate Theses and Dissertations

In the field of quantum information, which is subdivided into quantum computing and quantum cryptography, quantum correlations are essential for a performance or security boost not achievable with classical means. Various quantum correlation measures exist for evaluating a state’s potential to be a qubit (quantum bit). Entanglement, or nonseparability of quantum states, is the older, better known class of measures. However, for a mixed state, quantum entanglement is an incomplete measure of quantumness. Quantum discord, and its multibody extension global discord, encompass all quantum correlations. We study systems of coupled quantum dots using these measures.

We study the discord of …


A Study Of Short-Season Winter Cover Crops For Organic High Tunnel Production Systems, Luke Riley Freeman Dec 2016

A Study Of Short-Season Winter Cover Crops For Organic High Tunnel Production Systems, Luke Riley Freeman

Graduate Theses and Dissertations

This two-year study investigated short-season winter cover crops to improve soil quality and growth of subsequent vegetable crops in an organic high tunnel production system. Five winter cover crop treatments including a nontreated control, Austrian winter peas (Pisum arvense), bell beans (Vicia faba), mustard (Brassica juncea cv. Kodiak), and Daikon radish (Raphanus sativus var. longipinnatus) were grown in a high tunnel in a randomized complete block design from mid-November to mid-March, mowed and incorporated into the soil, and followed by a succession of vegetable crops including tomato (Lycopersicon lycopersicum, cv. ‘Plum Dandy’) and broccoli (Brassica oleracea var. italica, cv. ‘Bay …


A Gis Approach To Modeling Groundwater Levels In The Mississippi River Valley Alluvial Aquifer, Josef Orion Lilly Dec 2016

A Gis Approach To Modeling Groundwater Levels In The Mississippi River Valley Alluvial Aquifer, Josef Orion Lilly

Graduate Theses and Dissertations

Groundwater depletion, a subject of growing concern for a significant portion of Arkansas, may lead to future economic challenges for the Arkansas Delta region. The Mississippi River Valley Alluvial Aquifer is the uppermost aquifer and features the largest groundwater capacity in the Mississippi Embayment Aquifer System. The Mississippi River Valley Alluvial Aquifer, commonly referred to as the “alluvial aquifer”, spans 53,000〖 km〗^2 underlying portions of Arkansas, Kentucky, Louisiana, Mississippi, Missouri, Illinois, and Tennessee. As the alluvial aquifer trends southward for approximately 250 miles alongside the Mississippi River, its geographical extent ranges from 50 to 125 miles wide. There is a …


Liming Characteristics Of A High-Calcium, Dry Flue Gas Desulfurization By-Product And Its Effects On Runoff Water Quality, Jason Richard Burgess-Conforti Dec 2016

Liming Characteristics Of A High-Calcium, Dry Flue Gas Desulfurization By-Product And Its Effects On Runoff Water Quality, Jason Richard Burgess-Conforti

Graduate Theses and Dissertations

In 2013, only 37% of the 32 million Mg of flue gas desulfurization (FGD) by-products generated in the United States were reused beneficially. If FGD by-products could be used as a beneficial soil amendment, millions of megagrams may be diverted away from surface impoundments and landfills. The purpose of this research was to identify the liming characteristics of a high-Ca dry FGD (DFGD) by-product in comparison to a Class-C fly ash (FA) and reagent-grade CaCO3, and to evaluate the effects of land application to a managed grassland on runoff, plant, and soil quality. Liming characteristics were determined by measuring the …


Interactive Physics And Characteristics Of Photons And Photoelectrons In Hyperbranched Zinc Oxide Nanostructures, Garrett Edward Torix Dec 2016

Interactive Physics And Characteristics Of Photons And Photoelectrons In Hyperbranched Zinc Oxide Nanostructures, Garrett Edward Torix

Graduate Theses and Dissertations

As is commonly known, the world is full of technological wonders, where a multitude of electronic devices and instruments continuously help push the boundaries of scientific knowledge and discovery. These new devices and instruments of science must be utilized at peak efficiency in order to benefit humanity with the most advanced scientific knowledge. In order to attain this level of efficiency, the materials which make up these electronics, or possibly more important, the fundamental characteristics of these materials, must be fully understood. The following research attempted to uncover the properties and characteristics of a selected family of materials. Herein, zinc …


Synthesis, Characterization, And Fabrication Of All Inorganic Quantum Dot Leds, Haider Baqer Salman Dec 2016

Synthesis, Characterization, And Fabrication Of All Inorganic Quantum Dot Leds, Haider Baqer Salman

Graduate Theses and Dissertations

Quantum Dot LEDs with all inorganic materials are investigated in this thesis. The research was motivated by the potential disruptive technology of core shell quantum dots in lighting and display applications. These devices consisted of three main layers: hole transport layer (HTL), electron transport layer (ETL), and emissive layer where the emission of photons occurs. The latter part was formed of CdSe / ZnS core-shell quantum dots, which were synthesized following hot injection method. The ETL and the HTL were formed of zinc oxide nanocrystals and nickel oxide, respectively. Motivated by the low cost synthesis and deposition, NiO and ZnO …


Modeling The 3-Dimensional Structure Of D(Cgcgaattcgcg) And Its 8-Oxo-Da5 Adduct With 1h Nmr Noesy Refinements, Christopher Miles Reynolds Dec 2016

Modeling The 3-Dimensional Structure Of D(Cgcgaattcgcg) And Its 8-Oxo-Da5 Adduct With 1h Nmr Noesy Refinements, Christopher Miles Reynolds

Graduate Theses/Dissertations

Since the characterization of the oligomer d(CGCGAATTCGCG) has been published by Dickerson et al., computational studies have been carried out to produce an accurate 3D model. These models are important for visualizing how certain DNA repair enzymes, such as the glycosylases, recognize sites of damage by signatures of local 3D distortion. Using 1H NOESY-generated internuclear distances to replicate the model of this oligomer and a derivative with an 8-oxo-dA5 lesion, we propose characteristics of helical distortion that DNA glycosylases might use for identifying this form of damage. In addition, this method of comparison can be used to study the repair …


The Relationship Between Lead In Groundwater And Elementary School Students' Academic Performance In Missouri, Lynnette Xiangling Li Dec 2016

The Relationship Between Lead In Groundwater And Elementary School Students' Academic Performance In Missouri, Lynnette Xiangling Li

Graduate Theses/Dissertations

Lead exposure can come from various sources, e.g., lead mines, industrial areas, and lead based paint. Missouri has more than 4,128 lead mines. Lead is a neurotoxin. The objectives of the study were to investigate i) the spatial relationship between lead mines and lead distribution in groundwater, ii) the statistical impact of lead in groundwater on students' Missouri Assessment Program (MAP) scores, and iii) the geographic variations of lead's impact on students' MAP scores. Geographic Information Science spatial analysis tools were used to analyze the concentration of lead in groundwater within school districts in Missouri. Regression analysis was utilized to …


Examining Denitrification In Agricultural Ditch Sediments Vegetated With Rice Cutgrass (Leersia Oryzoides): Modeling Seasonal Variation Across Increasing Levels Of Nitrate Loading And Model Application To Pre-Existing Datasets, Shannon Lee Speir Dec 2016

Examining Denitrification In Agricultural Ditch Sediments Vegetated With Rice Cutgrass (Leersia Oryzoides): Modeling Seasonal Variation Across Increasing Levels Of Nitrate Loading And Model Application To Pre-Existing Datasets, Shannon Lee Speir

Graduate Theses and Dissertations

Nitrogen (N) derived from fertilizer application in agricultural systems may contribute to significant environmental impacts, including eutrophication of fresh and coastal waters. Rice cutgrass (Leersia oryzoides) can significantly enhance denitrification potential in agricultural ditch sediments, but relationships with known drivers are not well understood. To address this, I examined effects of nitrate (NO3-) availability on dinitrogen gas (N2) and NO3- fluxes seasonally in Chapter 2. Denitrification rates were measured as N2 flux from intact vegetated sediment cores using Membrane Inlet Mass Spectrometry (MIMS). Michaelis-Menten models were developed from observations to mathematically describe N2 fluxes across the spring, summer, and fall …


Inter-Relationships Linking Probability Of Becoming A Case Of Nicotine Dependence With Frequency Of Tobacco Cigarette Smoking, Olga A. Vsevolozhskaya, James C. Anthony Dec 2016

Inter-Relationships Linking Probability Of Becoming A Case Of Nicotine Dependence With Frequency Of Tobacco Cigarette Smoking, Olga A. Vsevolozhskaya, James C. Anthony

Biostatistics Faculty Publications

INTRODUCTION: Once smoking starts, some tobacco cigarette smokers (TCS) can make very rapid transitions into tobacco dependence syndromes (TCD). With adjustment for smoking frequency, we posit female excess risk for this rapid-onset TCD. In a novel application of functional analysis for tobacco research, we estimate four Hill function parameters and plot TCD risk against a gradient of smoking frequency, as observed quite soon after smoking onset.

METHODS: In aggregate, the National Surveys of Drug Use and Health, 2004-2013, identified 1546 newly incident TCS in cross-sectional research, each with standardized TCD assessment.

RESULTS: Hill function estimates contradict our apparently over-simplistic hypothesis. …


Pushback: Critical Data Designers And Pollution Politics, Kim Fortun, Lindsay Poirier, Alli Morgan, Brandon Costelloe-Kuehn, Mike Fortun Dec 2016

Pushback: Critical Data Designers And Pollution Politics, Kim Fortun, Lindsay Poirier, Alli Morgan, Brandon Costelloe-Kuehn, Mike Fortun

Statistical and Data Sciences: Faculty Publications

In this paper, we describe how critical data designers have created projects that ‘push back’ against the eclipse of environmental problems by dominant orders: the pioneering pollution database Scorecard, released by the US NGO Environmental Defense Fund in 1997; the US Environmental Protection Agency’s EnviroAtlas that brings together numerous data sets and provides tools for valuing ecosystem services; and the Houston Clean Air Network’s maps of real-time ozone levels in Houston. Drawing on ethnographic observations and interviews, we analyse how critical data designers turn scientific data and findings into claims and visualisations that are meaningful in contemporary political terms. The …


Complex Vegetation Dynamics At The Fire–Grazing–Drought Nexus, Christine H. Bielski Dec 2016

Complex Vegetation Dynamics At The Fire–Grazing–Drought Nexus, Christine H. Bielski

Department of Agronomy and Horticulture: Dissertations, Theses, and Student Research

The discipline of ecology long ago moved away from viewing systems as static entities where disturbance processes, environmental stochasticity, and spatiotemporal variability play minor roles in determining ecosystem structure and function. Ecological theory continue to develop frameworks and statistical techniques capable of describing the inherent complexity in natural systems. However, in dealing with the complexity in nature, many applied disciplines have yet to adopt such frameworks or statistical techniques. The objective of this study was bridge the gap between ecological theory and application by using complex systems theory to describe grassland vegetation dynamics at the fire-grazing-drought nexus. Chapters 2 and …


Early Miocene Quantitative Calcareous Nannofossil Biostratigraphy From The Tropical Atlantic, Waheed A. Albasrawi Dec 2016

Early Miocene Quantitative Calcareous Nannofossil Biostratigraphy From The Tropical Atlantic, Waheed A. Albasrawi

Department of Earth and Atmospheric Sciences: Dissertations, Theses, and Student Research

Quantitative analysis for the Lower Miocene of Ocean Drilling Program Hole 959A from the West African margin was performed to document all the calcareous nannofossil biostratigraphic events present. Combined with data from previous investigations of the Lower Miocene from the tropical Atlantic, this research identifies and tests the viability of markers used in current zonation scheme, identifies alternative markers for age boundaries, and examine statistically the most probable order of event in the Lower Miocene using the Ranking and Scaling method (RASC).

The examination of Hole 959A was performed on a 112 samples. Seven additional sites that collectively span the …


Exploration Of Student Biodiversity Knowledge And Decision-Making For A Wildlife Conservation Socioscientific Issue, Ashley R. Alred Dec 2016

Exploration Of Student Biodiversity Knowledge And Decision-Making For A Wildlife Conservation Socioscientific Issue, Ashley R. Alred

School of Natural Resources: Dissertations, Theses, and Student Research

Global biodiversity, a foundation for ecosystem function, is diminishing at a rate unprecedented in the last 50 years. Biodiversity loss and ecosystem services deterioration is linked to increased food insecurity, reduced water quality and availability, decreased energy security, higher economic losses and human suffering (Millennium Ecosystem Assessment, 2005). Consequently, educators should invest in supporting students in their development of ecological understanding and formal decision-making skills so they are equipped with meaningful tools they can use as scientifically literate citizens. To contribute to that mission, this study seeks to explore student 1) comprehension and explanation of biodiversity concepts and 2) decision-making …


College And University Sustainability Officers’ Experiences With Green Office Programs: A Qualitative Investigation, Logan Lamb Dec 2016

College And University Sustainability Officers’ Experiences With Green Office Programs: A Qualitative Investigation, Logan Lamb

School of Natural Resources: Dissertations, Theses, and Student Research

The number of sustainability programs in higher education continues to increase. Green office programs have become a cornerstone of sustainability programming on college and university campuses across the country. This exploratory qualitative study involves college and university sustainability officers and investigates their experiences changing behaviors through green office programs. The goal of this study was to provide insight into green office programs. Two side-by-side studies were conducted to provide a detailed analysis of green office programs at both small and large institutions of higher education. Eleven major themes emerged from the study. Six themes emerged from the qualitative analysis of …