Physical Sciences and Mathematics Commons^™

Comparison Of Canopy Temperature-Based Water Stress Indices Formaize, Kendall C. Dejonge, Saleh Taghvaeian, Thomas J. Trout, Lousie H. Thomas

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Infrared thermal radiometers (IRTs) are an affordable tool for researchers to monitor canopy tempera-ture. In this maize experiment, six treatments of regulated deficit irrigation levels were evaluated. Themain objective was to evaluate these six treatments in terms of six indices (three previously proposedand three introduced in this study) used to quantify water stress. Three are point-in-time indices whereone daily reading is assumed representative of the day (Crop Water Stress Index – CWSI, Degrees AboveNon-Stressed – DANS, Degrees Above Canopy Threshold – DACT) and three integrate the cumulativeimpact of water stress over time (Time Temperature Threshold – TTT, Integrated Degrees Above …

Identifying And Evaluating A Suitable Index For Agricultural Drought Monitoring In The Texas High Plains, Jerry E. Moorhead, Prasanna H. Gowda, Vijay P. Singh, Dana O. Porter, Thomas H. Marek, Terry A. Howell, B A. Stewart

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Drought is a complex and highly destructive natural phenomenon that affects portions of the United States almost every year, and severe water deficiencies can often become catastrophic for agricultural production. Evapotranspiration (ET) by crops is an important component in the agricultural water budget; thus, it is advantageous to include ET in agricultural drought monitoring. The main objectives of this study were to (1) conduct a literature review of drought indices with a focus to identify a simple but simultaneously adequate drought index for monitoring agricultural drought in a semiarid region and (2) using the identified drought index method, develop and …

The Effect Of Mineral-Ion Interactions On Soil Hydraulic Conductivity, Maya C. Buelow, Kerri Steenwerth, Sanjai J. Parikh

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

The reuse of winery wastewater (WW) could provide an alternative water source for vineyard irrigation.The shift of many wineries and other food processing industries to K+-based cleaners requires studies onthe effects of K+on soil hydraulic conductivity (HC). Depending on clay content and mineral composition,K+additions can affect the HC either positively or negatively. Soil mineralogy was anticipated to exhibita strong influence on HC responses and, therefore, soils of contrasting mineralogy were evaluated forchanges in soil HC resulting from applications of solutions elevated in Na+and K+. To examine the impactof mineral-ion relationships on HC, soils dominant in montmorillonite, vermiculite, or kaolinite from …

Fitness Costs Of Resistance To Cry3bb1 Maize By Western Corn Rootworm, A M. Hoffmann, B W. French, R L. Hellmich, N Lauter, A J. Gassmann

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Crops producing toxins derived from the bacterium Bacillus thuringiensis (Bt) are widely planted to manage insect pests including western corn rootworm, Diabrotica virgifera virgifera LeConte (Coleoptera: Chrysomelidae), which is a significant pest of maize in the United States and Europe. However, the widespread use of Bt maize places intense selection pressure on pest populations to evolve resistance, and field-evolved resistance to Bt maize by western corn rootworm has been documented in the United States. In conjunction with non-Bt refuges, fitness costs of Bt resistance can delay resistance evolution. Fitness costs arise in the absence of Bt toxin when individuals with …

Clonal Integration In Ludwigia Hexapetala Under Different Light Regimes, Rachael Glover, Rebecca E. Drenovsky, Caryn J. Futrell, Brenda J. Grewell

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Physiological integration among ramets of invasive plant species may support their colonization and spread in novel aquatic environments where growth-limiting resources are spatially heterogeneous. Under contrasting light conditions, we investigated how clonal integration influences growth, biomass allocation and morphology of Ludwigia hexapetala, an emergent floating-leaved macrophyte that is highly invasive in a range of wetland habitat types. In aquatic mesocosms, stolons of offspring ramets were either connected or severed from parent plants, with the pairs exposed to homogenous or heterogeneous combinations of sun or 85% shade. Morphological traits of all ramets were strongly influenced by light environment, and low light …

Development And Evaluation Of Bankfull Hydraulic Geometry Relationships For The Physiographic Regions Of The United States, Katrin Bieger, Hendrik Rathjens, Peter M. Allen, Jeffrey G. Arnold

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

Bankfull hydraulic geometry relationships are used to estimate channel dimensions for streamflow simulation models, which require channel geometry data as input parameters. Often, one nationwide curve is used across the entire United States (U.S.) (e.g., in Soil and Water Assessment Tool), even though studies have shown that the use of regional curves can improve the reliability of predictions considerably. In this study, regional regression equations predicting bankfull width, depth, and cross-sectional area as a function of drainage area are developed for the Physiographic Divisions and Provinces of the U.S. and compared to a nationwide equation. Results show that the regional …

Effects Of Refuges On The Evolution Of Resistance To Transgenic Corn By The Western Corn Rootworm, Diabrotica Virgifera Virgifera Leconte, Jennifer Deitloff, Mike W. Dunbar, David A. Ingber, Bruce E. Hibbard, Aaron J. Gassmann

United States Department of Agriculture-Agricultural Research Service / University of Nebraska-Lincoln: Faculty Publications

BACKGROUND: Diabrotica virgifera virgifera LeConte is a major pest of corn and causes over a billion dollars of economic loss annually through yield reductions and management costs. Corn producing toxins derived from Bacillus thuringiensis (Bt) has been developed to help manageD. v. virgifera.However, previous studies have demonstrated the ability of this species to evolve resistance to Bt toxins in both laboratory and field settings.

RESULTS: We used an experimental evolution approach to test the refuge strategies for delaying resistance of D. v. virgifera to corn producing Bt toxin Cry34/35Ab1. In the absence of refuges, D. v. virgifera developed resistance to …

Life And Liesegang: Outcrop-Scale Microbially Induced Diagenetic Structures And Geochemical Self-Organization Phenomena Produced By Oxidation Of Reduced Iron, Richard M. Kettler, David B. Loope, Karrie A. Weber, Paul B. Niles

Department of Earth and Atmospheric Sciences: Faculty Publications

The Kanab Wonderstone is sandstone (Shinarump Member, Chinle Formation) that is cemented and stained with iron oxide. The iron-oxide cementation and staining in these rocks have been considered examples of the Liesegang phenomenon, but we will show that they comprise a microbially induced structure. The spacing of bands of iron-oxide stain follow the Jablczynski spacing law (wherein the spacing between bands of iron-oxide stain increases as one traverses a series of bands) characteristic of Liesegang. Bands of iron-oxide cement exhibit more variable spacing and exhibit a weak but significant correlation between band thickness and distance between bands of cement. The …

Effect Of Cold Wave On Winter Visibility Over Eastern China, Wenjun Qu, Jun Wang, Xiaoye Zhang, Zhifeng Yang, Shanhong Gao

Department of Earth and Atmospheric Sciences: Faculty Publications

Considerable concern has been raised on the severe wintertime haze episodes over eastern China (ECN) where visibility (Vis) decline in winter is identified from 1973 to 2012 (-0.68 km per 10 years or -26% in 40 years). Based upon the analysis of daily Vis and weather records, cold wave (CW) originating from high latitudes is found to increase Vis by 2.7 km on average because of its relatively stronger wind and drier, cleaner air mass compared with the typical, stable midlatitude air over ECN in winter. However, the lessening frequency of CW occurrence and cold air activity in recent years …

Clique Topology Reveals Intrinsic Geometric Structure In Neural Correlations, Chad Giusti, Eva Pastalkova, Carina Curto, Vladimir Itskov

Department of Mathematics: Faculty Publications

Detecting meaningful structure in neural activity and connectivity data is challenging in the presence of hidden nonlinearities, where traditional eigenvalue-based methods may be misleading. We introduce a novel approach to matrix analysis, called clique topology, that extracts features of the data invariant under nonlinear monotone transformations. These features can be used to detect both random and geometric structure, and depend only on the relative ordering of matrix entries. We then analyzed the activity of pyramidal neurons in rat hippocampus, recorded while the animal was exploring a 2D environment, and confirmed that our method is able to detect geometric organization using …

Toric Varieties, Monoid Schemes And Cdh Descent, Guillermo Cortiñas, C. Haesemeyer, Mark E. Walker, Charles Weibel

Department of Mathematics: Faculty Publications

We give conditions for the Mayer–Vietoris property to hold for the algebraic K-theory of blow-up squares of toric varieties and schemes, using the theory of monoid schemes. These conditions are used to relate algebraic K-theory to topological cyclic homology in characteristic p. To achieve our goals, we develop many notions for monoid schemes based on classical algebraic geometry, such as separated and proper maps and resolution of singularities.

Are Conservation Organizations Configured For Effective Adaptation To Global Change?, Paul R. Armsworth, Eric R. Larson, Stephen T. Jackson, Dov F. Sax, Paul Simonin, Bernd Blossey, Nancy Green, Mary L. Klein, Liza Lester, Taylor H. Ricketts, Michael C. Runge, M. Rebecca Shaw

Rubenstein School of Environment and Natural Resources Faculty Publications

© The Ecological Society of America. Conservation organizations must adapt to respond to the ecological impacts of global change. Numerous changes to conservation actions (eg facilitated ecological transitions, managed relocations, or increased corridor development) have been recommended, but some institutional restructuring within organizations may also be needed. Here we discuss the capacity of conservation organizations to adapt to changing environmental conditions, focusing primarily on public agencies and nonprofits active in land protection and management in the US. After first reviewing how these organizations anticipate and detect impacts affecting target species and ecosystems, we then discuss whether they are sufficiently flexible …

A Framework To Assess The Health Of Rocky Reefs Linking Geomorphology, Community Assemblage, And Fish Biomass, Octavio Aburto-Oropeza, Exequiel Ezcurra, Jerry Moxley, Alexandra Sánchez-Rodríguez, Ismael Mascareñas-Osorio, Carlos Sánchez-Ortiz, Brad Erisman, Taylor Ricketts

Rubenstein School of Environment and Natural Resources Faculty Publications

The recovery of historic community assemblages on reefs is a primary objective for the management of marine ecosystems. Working under the overall hypothesis that, as fishing pressure increases, the abundance in upper trophic levels decreases followed by intermediate levels, we develop an index that characterizes the comparative health of rocky reefs. Using underwater visual transects to sample rocky reefs in the Gulf of California, Mexico, we sampled 147 reefs across 1200 km to test this reef health index (IRH). Five-indicators described 88% of the variation among the reefs along this fishing-intensity gradient: the biomass of piscivores and carnivores were positively …

Social Entrepreneurship And Social Business: Retrospective And Prospective Research, Edgard Barki, Graziella Comini, Ann Cunliffe, Stuart Hart, Sudhanshu Rai

Grossman School of Business Faculty Publications

Social Entrepreneurship and Social Business (SE/SB), inclusive business, businesses with social impact and a higher purpose are becoming increasingly important both in academia and the business world (Sassmannshausen & Volkmann, 2013). Since the influential article by Dees (1998), many different perspectives about social entrepreneurship and social business have been discussed in academia. On the management side, these types of businesses have also proliferated in the last decades. Yunus with his work leading Grameen Bank has inspired many other entrepreneurs and organizations to create a new kind of business more embedded with a social purpose. The main purpose of the Social …

Set Lister, Cyril Casapao

Honors Projects

No abstract provided.

Gentrified Sustainability: Inequitable Development And Seattle’S Skewed Riskscape, Troy D. Abel, Jonah White

College of the Environment on the Peninsulas Publications

This paper examines the tensions of sustainable development in Seattle, Washington, a commonly recognised urban environmental leader. Drawing on the perspective of sustainability as a conflicted process, this research expected a negative relationship between gentrification and environmental justice when affluent residents outcompete less affluent ones for neighbourhoods with fewer environmental hazards. The methods combine geographic cluster analysis and longitudinal air toxic emission comparisons to analyse socioeconomic changes in Seattle Census block-groups between 1990, 2000, and 2009 coupled with measures of relative potential risk and pollution volume. The property and development conflicts embedded within sustainability lead to pollution exposure risk and …

Quantum And Post-Newtonian Effects In The Anomalistic Period And The Mean Motion Of Celestial Bodies, Ioannis Haranas, Omiros Ragos, Ioannis Gkigkitzis, Ilias S. Kotsireas

Physics and Computer Science Faculty Publications

We study the motion of a secondary celestial body under the influence of the corrected gravitational force of a primary. We study the effect of quantum and relativistic corrections to the gravitational potential of a primary body acting on the orbiting body. More specifically, two equations are derived to approximate the perigee/perihelion/periastron time rate of change and its total variation over one revolution (i.e., the difference between the anomalistic period and the Keplerian period) under the influence of the quantum as well as post-Newtonian accelerations. Numerical results have been obtained for the artificial Earth satellite Molnya, Mercury, and, finally, the …

The Critical Importance Of Large Expanses Of Continuous Forest For Bird Conservation, Robert A. Askins

Biology Faculty Publications

No abstract provided.

Serve Or Skip: The Power Of Rejection In Online Bottleneck Matching, Barbara M. Anthony, Christine Chung

Computer Science Faculty Publications

We consider the online matching problem, where n server-vertices lie in a metric space and n request-vertices that arrive over time each must immediately be permanently assigned to a server-vertex.We focus on the egalitarian bottleneck objective, where the goal is to minimize the maximum distance between any request and its server. It has been demonstrated that while there are effective algorithms for the utilitarian objective (minimizing total cost) in the resource augmentation setting where the offline adversary has half the resources, these are not effective for the egalitarian objective. Thus, we propose a new Serve-or-Skip bicriteria analysis model, where the …

The Health Risks Of Chemicals In Personal Care Products And Their Fate In The Environment, Lisa Paulsen

Chemistry Honors Papers

Personal care products are everyday consumer products used to cleanse, enhance, or alter the appearance of the body, including, but not limited to, shampoos, body washes, lotions, and cosmetics. The regulations and safety information surrounding personal care products are severely lacking. The laws regulating the environmental fate of these chemicals and the harmful effects they can have on environmental ecosystems or organisms that are exposed to them are even more limited. However, studies have shown that the chemicals can have a dizzying array of health risks, including diseases on the rise in human populations such as diabetes, obesity, autism, ADHD, …

Characterization Of Increased Persistence And Intensity Of Precipitation In The Northeastern United States, Justin Guilbert, Alan K. Betts, Donna M. Rizzo, Brian Beckage, Arne Bomblies

College of Engineering and Mathematical Sciences Faculty Publications

We present evidence of increasing persistence in daily precipitation in the northeastern United States that suggests that global circulation changes are affecting regional precipitation patterns. Meteorological data from 222 stations in 10 northeastern states are analyzed using Markov chain parameter estimates to demonstrate that a significant mode of precipitation variability is the persistence of precipitation events. We find that the largest region‐wide trend in wet persistence (i.e., the probability of precipitation in 1 day and given precipitation in the preceding day) occurs in June (+0.9% probability per decade over all stations). We also find that the study region is experiencing …

Acoustic Streaming, Fluid Mixing, And Particle Transport By A Gaussian Ultrasound Beam In A Cylindrical Container, Jeffrey S. Marshall, Junru Wu

College of Engineering and Mathematical Sciences Faculty Publications

A computational study is reported of the acoustic streaming flow field generated by a Gaussian ultrasound beam propagating normally toward the end wall of a cylindrical container. Particular focus is given to examining the effectiveness of the acoustic streaming flow for fluid mixing within the container, for deposition of particles in suspension onto the bottom surface, and for particle suspension from the bottom surface back into the flow field. The flow field is assumed to be axisymmetric with the ultrasound transducer oriented parallel to the cylinder axis and normal to the bottom surface of the container, which we refer to …

A Protocol For Eliciting Nonmaterial Values Through A Cultural Ecosystem Services Frame, Rachelle K. Gould, Sarah C. Klain, Nicole M. Ardoin, Terre Satterfield, Ulalia Woodside, Neil Hannahs, Gretchen C. Daily, Kai M. Chan

Rubenstein School of Environment and Natural Resources Faculty Publications

Conservation Biology published by Wiley Periodicals, Inc. on behalf of Society for Conservation Biology. Stakeholders' nonmaterial desires, needs, and values often critically influence the success of conservation projects. These considerations are challenging to articulate and characterize, resulting in their limited uptake in management and policy. We devised an interview protocol designed to enhance understanding of cultural ecosystem services (CES). The protocol begins with discussion of ecosystem-related activities (e.g., recreation, hunting) and management and then addresses CES, prompting for values encompassing concepts identified in the Millennium Ecosystem Assessment (2005) and explored in other CES research. We piloted the protocol in Hawaii …

Master's Project: Assessing Unpaved Road Runoff In The Mad River Watershed Of Central Vermont, Catherine Webster

Rubenstein School Masters Project Publications

Over half of the local town roads in Vermont are unpaved (VBB, 2009). In the Mad River Watershed of central Vermont, 58% of the roads are unpaved. These compacted surfaces, despite their lack of tar, provide hundreds of miles of impermeable surfaces that extend the stream network, and transport runoff and pollutants to our water bodies. In this project, 12 sites within the Mad River watershed were monitored with the goal of evaluating the amount of runoff that is generated on the road surface itself as compared to flow that enters roadside ditches via groundwater seeps and overland flow from …

Reductions Of Wheat Yield And Yield Components And Nitrogen Loss Following Frozen Soil Nitrogen Applications, Carrie Ann Knott, Edwin L. Ritchey, Lloyd W. Murdock

Plant and Soil Sciences Research Report

Most wheat producers in Kentucky apply nitrogen (N) as a split application. The first N increment is applied when wheat plants begin actively growing (green-up) in late winter, which is typically in mid- February between growth stages Feekes 2 to 3. The second N increment typically occurs in March when wheat is between Feekes 5 to 6. Many producers in Kentucky, especially Western Kentucky, have become accustomed to beginning first N applications in late January when the ground is frozen and the wheat is still dormant. This practice allows them to apply N to large acreages of wheat while avoiding …

Quality Of Water From Tile Drains In Fields Treated With Poultry Litter In Mclean County, Kentucky, E. Glynn Beck, Lisa Y. Blue, David A. Atwood

Information Circular--KGS

Poultry litter (a mixture of feed, manure, and bedding material) is commonly used as a soil amendment to row-crop fields in western Kentucky. Because of feed additives, litter typically has elevated concentrations of contaminants, including metals and anions. These metals and anions can accumulate in the soil and therefore could be transported to surface water through drainage tiles. In order to assess water quality in tile drains, a pilot study was conducted in 2008 in McLean County, Kentucky, in which 10 tile drains and six drainage ditches were sampled for total metals and anions. Seven of the tile-drained fields were …

An Optical Sprayer Nozzle Flow Rate Sensor, Joseph S. Dvorak, Luke E. Bryant

Biosystems and Agricultural Engineering Faculty Publications

Ensuring proper flow rates from each nozzle on an agricultural sprayer has become even more important as advances continue to be made in precision application technology. In this article, we describe the structure and testing of a sensor technology based on optical cross-correlation to determine the flow rate of individual sprayer nozzles. An advantage of this technology is that it does not require that impellers or other components be placed in the flow, which could cause plugging. The only moving part in the entire system is a solenoid used to inject a tracer dye. The objective of this study was …

Assessing The Relative Mobility Of Submarine Landslides From Deposit Morphology And Physical Properties: An Example From Kumano Basin, Nankai Trough, Offshore Japan, Zachary T. Moore

Theses and Dissertations--Earth and Environmental Sciences

A prominent landslide deposit in the Slope Basin seaward of the Megasplay Fault in the Nankai Trough was emplaced by a high-mobility landslide based on analysis of physical properties and seismic geomorphology. Slide acceleration is a critical variable that determines amplitude of slide-generated tsunami but is many times a variable with large uncertainty. In recent controlled laboratory experiments, the ratio of the shear stress to yield strength (defined as the Flow Factor) controls a wide spectrum of mass movement styles from slow, retrogressive failure to rapid, liquefied flows. Here, we apply this laboratory Flow Factor approach to a natural landslide …

Finding Mars Paleopoles From Magnetization Edge Effects To Determine The History Of Mars’ Core Dynamo, Melissa Lynn Ditty

Theses and Dissertations--Earth and Environmental Sciences

This is a new method of determining magnetization strength, direction, and paleopole location from magnetic anomalies across edges of the equatorial band of magnetic sources on Mars. Different assumed locations of paleopoles result in different inducing field directions in the vicinity of an edge. Thus, with different paleopoles, the resulting magnetic fields from the edges of magnetic sources are different, and correlate differently with the observed fields. Best correlating observed and computed magnetic edge effect fields yield the potential paleopoles. The total gradient (TG) of the z-component magnetic field was used to identify the edges of magnetization boundaries. Three edge …

Bedrock Geologic Mapping And Structural Analysis Of The Western Half Of The Petersham Quadrangle, Central Massachusetts: Further Tests Of The Model For Middle To Late Paleozoic Ductile Transpression, Vertical Extrusion, And Lateral Escape In The Northern Appalachians, Lucas P. Rohrer

Theses and Dissertations--Earth and Environmental Sciences

Bedrock mapping, structural analysis, and geochronology reveal the distribution of lithologies and timing of metamorphism and deformation in the western half of the Petersham 7.5’ quadrangle, western Massachusetts. Underlying lithologies are: (from west to east) the Ordovician Monson granitic orthogneiss, Silurian Rangeley migmatitic paragneiss, and Late Devonian (357 Ma) Hardwick tonalitic orthogneiss. Their tightly folded contacts strike north to south. The 361 Ma, unfoliated, strike-parallel Nichewaug quartz-diorite (10-100 m wide) intrusion spans the map area within the Rangeley. Evidence for vertical and lateral extrusion/escape of the Monson orthogneiss, as observed in the Palmer MA area, is absent. Instead, petrofabrics (foliations …