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

Civil and Environmental Engineering Commons™

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

University of Nebraska - Lincoln

Discipline
Keyword
Publication Year
Publication
Publication Type
File Type

Articles 1171 - 1200 of 2277

Full-Text Articles in Civil and Environmental Engineering

Concomitant Uptake Of Antimicrobials And Salmonella In Soil And Into Lettuce Following Wastewater Irrigation, J. Brett Sallach, Yuping Zhang, Laurie Hodges, Daniel D. Snow, Xu Li, Shannon L. Bartelt-Hunt Feb 2015

Concomitant Uptake Of Antimicrobials And Salmonella In Soil And Into Lettuce Following Wastewater Irrigation, J. Brett Sallach, Yuping Zhang, Laurie Hodges, Daniel D. Snow, Xu Li, Shannon L. Bartelt-Hunt

Department of Civil and Environmental Engineering: Faculty Publications

The use of wastewater for irrigation may introduce antimicrobials and human pathogens into the food supply through vegetative uptake. The objective of this study was to investigate the uptake of three antimicrobials and Salmonella in two lettuce cultivars. After repeated subirrigation with synthetic wastewater, lettuce leaves and soil were collected at three sequential harvests. The internalization frequency of Salmonella in lettuce was low. A soil horizon-influenced Salmonella concentration gradient was determined with concentrations in bottom soil 2 log CFU/g higher than in top soil. Lincomycin and sulfamethoxazole were recovered from lettuce leaves at concentrations as high as 822 ng/g and …


2015 Nebraska Groundwater Quality Monitoring Report Jan 2015

2015 Nebraska Groundwater Quality Monitoring Report

Nebraska Department of Environmental Quality: Reports

The 2001 Nebraska Legislature passed LB329 (Neb. Rev. Stat. §46-1304) which, in part, directed the Nebraska Department of Environmental Quality (NDEQ) to report on groundwater quality monitoring in Nebraska. Reports have been issued annually since December 2001. The text of the statute applicable to this report follows: “The Department of Environmental Quality shall prepare a report outlining the extent of ground water quality monitoring conducted by natural resources districts during the preceding calendar year. The department shall analyze the data collected for the purpose of determining whether or not ground water quality is degrading or improving and shall present the …


Feasibility Analysis Of Phase Transition Signals Based On E-Bike Rider Behavior, Sheng Dong, Jibiao Zhou, Li Zhao, Keshuang Tang, Renfa Yang Jan 2015

Feasibility Analysis Of Phase Transition Signals Based On E-Bike Rider Behavior, Sheng Dong, Jibiao Zhou, Li Zhao, Keshuang Tang, Renfa Yang

Mid-America Transportation Center: Final Reports and Technical Briefs

This article evaluates the feasibility of two scenarios of phase transition signals, that is, the flashing green together with red–yellow light and the green countdown together with red countdown, at signalized intersections in terms of e-bike rider behavior. An evaluation framework is first proposed. During the phase transition, the stop-go and start-up behavioral parameters are collected at four intersections in Shanghai, China. Sensitivity analysis is then performed to identify the most significant factors that influence the occurrence of traffic conflicts during the phase transition. Based on the above analysis results, case studies were finally done to look into safety performance …


Eight Principles Of Uncertainty For Life Cycle Assessment Of Biofuel Systems, Adam J. Liska Jan 2015

Eight Principles Of Uncertainty For Life Cycle Assessment Of Biofuel Systems, Adam J. Liska

Adam Liska Papers

New environmental regulations in the USA and Europe require a reduction of greenhouse gas (GHG) emissions from transportation fuels as a component of climate change mitigation policy. The US Energy Independence and Security Act of 2007 (EISA) requires GHG emission reductions from the life cycles of biofuels compared to gasoline, by 20% for ethanol from maize grain (maize-ethanol), 60% for cellulosic ethanol, and 50% for other advanced biofuels. To determine these reductions, the US Environmental Protection Agency (EPA) employs life cycle assessment (LCA) methods which were not used previously in national environmental regulations. These regulations, entitled the “Renewable Fuel Standard …


Nephrotoxic Contaminants In Drinking Water And Urine, And Chronic Kidney Disease In Rural Sri Lanka, Tewodros Rango, Marc Jeuland, Herath Manthrithilake, Peter G. Mccornick Jan 2015

Nephrotoxic Contaminants In Drinking Water And Urine, And Chronic Kidney Disease In Rural Sri Lanka, Tewodros Rango, Marc Jeuland, Herath Manthrithilake, Peter G. Mccornick

Daugherty Water for Food Global Institute: Faculty Publications

Chronic kidney disease of unknown (“u”) cause (CKDu) is a growing public health concern in Sri Lanka. Prior research has hypothesized a link with drinking water quality, but rigorous studies are lacking. This study assesses the relationship between nephrotoxic elements (namely arsenic (As), cadmium (Cd), lead (Pb), and uranium (U)) in drinking water, and urine samples collected from individuals with and/or without CKDu in endemic areas, and from individuals without CKDu in nonendemic areas. All water samples—from a variety of source types (i.e., shallow and deep wells, springs, piped, and surface water)—contained extremely low concentrations of nephrotoxic elements, and all …


Demonstration Of A Daily High-Resolution (375-M) Alexi Evapotranspiration Product For The Nena Region, Christopher Hain, Martha C. Anderson, Mitch Schull, Christopher M.U. Neale Jan 2015

Demonstration Of A Daily High-Resolution (375-M) Alexi Evapotranspiration Product For The Nena Region, Christopher Hain, Martha C. Anderson, Mitch Schull, Christopher M.U. Neale

Daugherty Water for Food Global Institute: Faculty Publications

While the current constellation of geostationary sensors provides near-global coverage (60N to 60S) – it requires merging data from 7 satellites [resolving time differences; view angles; atmospheric correction]. Polar orbiting sensors such as MODIS and VIIRS provide daily global coverage of LST at higher resolutions than GEO sensors but at only two times per day.


Assessment Of Village Chicken Production Systems In Kambata Tambaro And Wolaita Zones, Snnpr, Ethiopia, Aman Getiso, Fitsum Tessema, Mesfin Mekonnen, Addisu Jimma, Bereket Zeleke Jan 2015

Assessment Of Village Chicken Production Systems In Kambata Tambaro And Wolaita Zones, Snnpr, Ethiopia, Aman Getiso, Fitsum Tessema, Mesfin Mekonnen, Addisu Jimma, Bereket Zeleke

Daugherty Water for Food Global Institute: Faculty Publications

The study was conducted in four woredas (Damot Gale,Of a, Angacha and Hadero Tunto) the first two of them found in Wolaita zone and two of them in Kambata Tambaro Zone of SNNPR, Ethiopia respectively. A cross-sectional survey was conducted in the study areas to assess village chicken production systems, productive and reproductive performance of village chicken and identifying constraints to village chicken production. Stratified random sampling technique was used to select 240 farming households and administer a pre-tested and structured questionnaire. The results showed that the mean age of interviewed farmers was 37.8±9.3 years; average family size & chicken …


Yield Gap Analysis Of Field Crops: Methods And Case Studies, V. O. Sadras, Kenneth Cassman, Patricio Grassini, W. G.M. Bastiaanssen, A. G. Laborte, A. E. Milne, G. Sileshi, P. Steduto Jan 2015

Yield Gap Analysis Of Field Crops: Methods And Case Studies, V. O. Sadras, Kenneth Cassman, Patricio Grassini, W. G.M. Bastiaanssen, A. G. Laborte, A. E. Milne, G. Sileshi, P. Steduto

Daugherty Water for Food Global Institute: Faculty Publications

The challenges of global agriculture have been analysed exhaustively and the need has been established for sustainable improvement in agricultural production aimed at food security in a context of increasing pressure on natural resources. Whereas the importance of R&D investment in agriculture is increasingly recognised, better allocation of limited funding is essential to improve food production. In this context, the common and often large gap between actual and attainable yield is a critical target. Realistic solutions are required to close yield gaps in both small and large scale cropping systems worldwide; to make progress in this direction, we need (1) …


2015 Nebraska Water Monitoring Programs Report, Marty Link, Ryan Chapman Jan 2015

2015 Nebraska Water Monitoring Programs Report, Marty Link, Ryan Chapman

Nebraska Department of Environmental Quality: Reports

The Nebraska Department of Environmental Quality (NDEQ) is charged with monitoring, assessing, and to the extent possible, managing the state’s water resources. The purpose of this work is to protect and maintain high quality water and encourage or execute activities to improve poor water quality. Monitoring is done on nearly 17,000 miles of flowing rivers and streams, more than 134,000 acres of surface water in lakes and reservoirs, as well as the vast storage of groundwater in Nebraska’s aquifers.


Voc Emissions From Beef Feedlot Pen Surfaces As Affected By Within-Pen Location, Moisture And Temperature, Bryan L. Woodbury, John E. Gilley, David B. Parker, David B. Marx, Roger A. Eigenberg Jan 2015

Voc Emissions From Beef Feedlot Pen Surfaces As Affected By Within-Pen Location, Moisture And Temperature, Bryan L. Woodbury, John E. Gilley, David B. Parker, David B. Marx, Roger A. Eigenberg

Department of Statistics: Faculty Publications

A laboratory study was conducted to evaluate the effects of pen location, moisture, and temperature on emissions of volatile organic compounds (VOC) from surface materials obtained from feedlot pens where beef cattle were fed a diet containing 30% wet distillers grain plus solubles. Surface materials were collected from the feed trough (bunk), drainage, and raised areas (mounds) within three feedlot pens. The surface materials were mixed with water to represent dry, wet, or saturated conditions and then incubated at temperatures of 5, 15, 25 and 35 C. A wind tunnel and gas chromatograph-mass spectrometer were used to collect and quantify …


Attachment Of A Combination Bridge Rail To Concrete Parapet Utilizing Epoxy Adhesive Anchors, Robert W. Bielenberg, John D. Reid, Scott K. Rosenbaugh, Austin J. Haase, Ronald K. Faller Jan 2015

Attachment Of A Combination Bridge Rail To Concrete Parapet Utilizing Epoxy Adhesive Anchors, Robert W. Bielenberg, John D. Reid, Scott K. Rosenbaugh, Austin J. Haase, Ronald K. Faller

Mid-America Transportation Center: Final Reports and Technical Briefs

The Iowa Department of Transportation (IaDOT) was interested in investigating the use of epoxy adhesive anchorages

for the attachment of posts used in the BR27C combination bridge rail system. Alternative anchorage concepts were developed using a modified version of the ACI 318-11 procedures for embedded anchor design. Four design concepts were developed for review by IaDOT, including: (1) a four-bolt square anchorage, (2) a four-bolt spread anchorage, (3) a two- bolt centered anchorage, and (4) a two-bolt offset anchorage. IaDOT representatives selected the four-bolt spread anchorage and the two-bolt offset anchorage as the preferred designs for evaluation. In addition to …


Nebraska Water Center Annual Report 2015, Nebraska Water Center Jan 2015

Nebraska Water Center Annual Report 2015, Nebraska Water Center

Nebraska Water Center: Administrative Materials

Contents

Foreword 4

The Nebraska Water Center: Leadership in Research, Education and Communication 6

Director’s Letter 8

For More Than 50 years: The Nebraska Water Center 10

Helping Build the Future 11

Nebraska Water Center Advisory Board 14

Water Resources Advisory Panel: A key to success 15

Information for Our Clients and the Public 16

Primary Goals 18

USGS 104b Projects 20

Dvorak, Ray Aim at Improving Water Quality for Small Communities 20

October Retreat at UNK 24

Public Water Lectures 25

2015 Special Seminars 26

2015 Water Symposium and Water Law Conference 28

Water Tour Visits Republican River Basin …


Flow, Spray Pattern, And Droplet Spectra Characteristics Of An Electronically Actuated Variable-Orifice Nozzle, Joe D. Luck, Santosh Pitla, M. P. Sama, S. A. Shearer Jan 2015

Flow, Spray Pattern, And Droplet Spectra Characteristics Of An Electronically Actuated Variable-Orifice Nozzle, Joe D. Luck, Santosh Pitla, M. P. Sama, S. A. Shearer

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The purpose of this study was to develop and evaluate the flow rate, spray pattern, and droplet spectra characteristics of an actively controlled variable-orifice nozzle at constant carrier pressures. A commercially available variable- orifice nozzle (VariTarget) was modified to allow for direct electromechanical control of the metering stem. The modified system was tested at five carrier pressures ranging from 138 to 414 kPa and five metering stem (and thus orifice) positions. The metering stem position range was chosen because it provided a linear response in flow rate at each carrier pressure. Flow rate testing indicated a turndown ratio of 2.4:1 …


Accounting For The Short Term Substitution Effects Of Walking And Cycling In Sustainable Transportation, Daniel P. Piatkowski, Kevin J. Krizek, Susan L. Handy Jan 2015

Accounting For The Short Term Substitution Effects Of Walking And Cycling In Sustainable Transportation, Daniel P. Piatkowski, Kevin J. Krizek, Susan L. Handy

Community and Regional Planning Program: Faculty Scholarly and Creative Activity

The environmental benefits of bicycling and walking depend on the degree to which their use substitutes for car driving. Assuming that every walking and bicycling trip replaces a driving trip is likely to produce overestimates of the potential for such modes to reduce vehicle travel and city-scale greenhouse gas emissions. Measuring this ‘‘substitution effect’’ is not straightforward. There are many dimensions of the substitution effect, including trip type, substituting mode, extent, time horizon, and activity patterns. Previously used approaches to measure substitution include indirect inference and direct questioning. This study piloted an intercept survey using the direct questioning approach at …


Control System Development And Response Analysis Of An Electronically Actuated Variable-Orifice Nozzle For Agricultural Pesticide Applications, Joe D. Luck, S. A. Shearer, M. P. Sama, Santosh Pitla Jan 2015

Control System Development And Response Analysis Of An Electronically Actuated Variable-Orifice Nozzle For Agricultural Pesticide Applications, Joe D. Luck, S. A. Shearer, M. P. Sama, Santosh Pitla

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The goal of this research project was to further the development of an electromechanically controlled variable-orifice nozzle by creating an electronic control system and then evaluating that system based on step and ramp inputs. The control system was developed in a programming environment that combined an electronic data acquisition system and actuator with pressure and flow sensors. A proportional, variable-gain (based on system pressure) control system was developed to adjust nozzle flow rates to meet target application rates. The constraints were to achieve settling time of less than 1.0 s, overshoot of less than 10% of maximum flow (or minimum …


An Investigation Into Bacterial Contamination In An Urban Nebraska Stream Using Microbial Source Tracking, Allison R. Speicher Jan 2015

An Investigation Into Bacterial Contamination In An Urban Nebraska Stream Using Microbial Source Tracking, Allison R. Speicher

Department of Civil and Environmental Engineering: Dissertations, Theses, and Student Research

High levels of fecal bacteria in surface waters are a public health concern due to the enteric illnesses caused by primary contact with these waters. Shortcomings in the current fecal indicator bacteria (FIB) monitoring approach and the ubiquity of pathogen-impaired water bodies has led to the development of microbial source tracking (MST), a molecular tool that can identify potential fecal contamination sources. In this study we use a bacterial community based approach examining the V4 region of the 16S rRNA gene to elucidate sources of fecal bacteria in Antelope Creek, an urban creek in Lincoln Nebraska.

We hypothesized that sediment …


Cable-To-Post Attachments For A Non-Proprietary High-Tension Cable Barrier – Phase Ii, Scott K. Rosenbaugh, Robert W. Bielenberg, Brandt M. Humphrey, Ronald K. Faller, John D. Reid, Karla A. Lechtenberg Jan 2015

Cable-To-Post Attachments For A Non-Proprietary High-Tension Cable Barrier – Phase Ii, Scott K. Rosenbaugh, Robert W. Bielenberg, Brandt M. Humphrey, Ronald K. Faller, John D. Reid, Karla A. Lechtenberg

Mid-America Transportation Center: Final Reports and Technical Briefs

The research objectives reported herein were based on further development of cable-to-post attachment hardware for use in the non-proprietary high-tension cable barrier system. Specifically, this project aimed to develop and evaluate alternative attachment designs for the bolted, tabbed bracket and evaluate the use of a larger diameter, keeper rod for use in the top cable attachment.

From a group of over 25 alternative attachment concepts, two tabbed bracket designs were selected for evaluation through dynamic component testing: 1) the lateral shear plate attachment and 2) the drop-in shear plate attachment. The drop-in shear plate concept did not perform as intended, …


Detection, Occurrence And Fate Of Emerging Contaminants In Agricultural Environments, Daniel D. Snow, David A. Cassada, Shannon L. Bartelt-Hunt, Xu Li, Matteo D'Alessio, Rachel Levine, Yun Zhang, J. Brett Sallach Jan 2015

Detection, Occurrence And Fate Of Emerging Contaminants In Agricultural Environments, Daniel D. Snow, David A. Cassada, Shannon L. Bartelt-Hunt, Xu Li, Matteo D'Alessio, Rachel Levine, Yun Zhang, J. Brett Sallach

Nebraska Water Center: Faculty Publications

A total of 43 papers published in 2014 were reviewed ranging from detailed descriptions of analytical methods, to fate and occurrence studies, to measuring and predicting biological effects for a wide variety of emerging contaminants likely to occur in agricultural environments. New methods and studies on veterinary pharmaceuticals, natural and synthetics steroids, and antibiotic resistance genes in agricultural environments continue to expand our knowledge base on the occurrence and potential impacts of these compounds. This review is divided into the following sections: Introduction, Analytical Methods, Occurrence and Fate, Antibiotic Resistance Genes, and Risk Assessment.


Using Simulated Virtual Interactivity In Construction Education, Saeed Rokooei, James D. Goedert Jan 2015

Using Simulated Virtual Interactivity In Construction Education, Saeed Rokooei, James D. Goedert

Department of Construction Engineering and Management: Faculty Publications

This paper briefly illustrates the design procedure, implementation and findings of a three year research project. Virtual Interactive Construction Education (VICE) is a project-based pedagogical model that uses a simulated environment to alter traditional subject-based lectures into virtual project-based interactive learning methods in construction education. For this purpose, the context of construction engineering and management curricula were aggregated into six construction project prototypes. VICE-Bridge is the first of these six prototypes that exposes players to experiential problem solving activities toward achieving a goal situation (construct the bridge) from an initial situation (start of construction). It was designed for students with …


Evaluation Of Sixteen Reference Evapotranspiration Methods Under Sahelian Conditions In The Senegal River Valley, Koffi Djaman, Alpha B. Balde, Abdoulaye Sow, Bertrand Muller, Suat Irmak, Mamadou K. N'Diaye, Baboucarr Manneh, Yonnelle D. Moukoumbi, Koichi Futakuchi, Kazuki Saito Jan 2015

Evaluation Of Sixteen Reference Evapotranspiration Methods Under Sahelian Conditions In The Senegal River Valley, Koffi Djaman, Alpha B. Balde, Abdoulaye Sow, Bertrand Muller, Suat Irmak, Mamadou K. N'Diaye, Baboucarr Manneh, Yonnelle D. Moukoumbi, Koichi Futakuchi, Kazuki Saito

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Study region: Reference evapotranspiration (ETo) plays a key role in irrigation sys-tems design, water management under irrigated and rainfed production. Underthe sahelian conditions in the Senegal River Valley that receives less than 300 mmannual rainfall, rice crop water use should be estimated for the sustainability of theresource. Study focus: However the Penman–Monteith (PM) equation is revealed the mostaccurate one; it necessitates several climatic parameters that are not always avail-able mostly in the developing countries. The objective of this study was to evaluatethe performance of 16 ETo equations against the ASCE-PM equation under thesahelian conditions at Ndiaye and Fanaye …


Uncertainty Analysis Of An Irrigation Scheduling Model For Water Management In Crop Production, S. Mun, G. F. Sassenrath, Amy M. Schmidt, N. Lee, M. C. Wadsworth, B. Rice, Jason Q, Corbitt, J. M. Schneider, M. L. Tagert, J. Pote, R. Prabhu Jan 2015

Uncertainty Analysis Of An Irrigation Scheduling Model For Water Management In Crop Production, S. Mun, G. F. Sassenrath, Amy M. Schmidt, N. Lee, M. C. Wadsworth, B. Rice, Jason Q, Corbitt, J. M. Schneider, M. L. Tagert, J. Pote, R. Prabhu

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Irrigation scheduling tools are critical to allow producers to effectively manage water resources for crop production. To be useful, these tools need to be accurate, complete, and relatively reliable. The current work presents an uncertainty analysis and its results for the Mississippi Irrigation Scheduling Tool (MIST) model, showing the margin of error (uncertainty) of the resulting irrigation advice arising solely from the propagation of measurement uncertainty through the MIST calculations. The final relative uncertainty in the water balance value from MIST was shown to be around 9% of that value, which is in the normal range of the margin of …


Development Of A Turbidity Prediction Methodology For Runoff-Erosion Models, Sagar Neupane, Jason R. Vogel, Daniel E. Storm, Bill J. Barfield, Aaron R. Mittelstet Jan 2015

Development Of A Turbidity Prediction Methodology For Runoff-Erosion Models, Sagar Neupane, Jason R. Vogel, Daniel E. Storm, Bill J. Barfield, Aaron R. Mittelstet

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Surface water bodies can be impaired by turbidity and excessive sediment loading due to urban development, construction activities, and agricultural practices. Turbidity has been considered as a proxy for evaluating water quality, aquatic habitat, and aesthetic impairments in surface waters. The US Environment Protection Agency (USEPA) has listed turbidity and sediment as major pollutants for construction site effluent. Recently proposed USEPA regulations for construction site runoff led to increased interest in methods to predict turbidity in runoff based on parameters that are more commonly predicted in runoff- erosion models. In this study, a turbidity prediction methodology that can be easily …


Robust Estimates Of Soil Moisture And Latent Heat Flux Coupling Strength Obtained From Triple Collocation, Wade T. Crow, Fangni Lei, Christopher R. Hain, Martha C. Anderson, Russell L. Scott, David P. Billesbach, Timothy Arkebauer Jan 2015

Robust Estimates Of Soil Moisture And Latent Heat Flux Coupling Strength Obtained From Triple Collocation, Wade T. Crow, Fangni Lei, Christopher R. Hain, Martha C. Anderson, Russell L. Scott, David P. Billesbach, Timothy Arkebauer

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Land surface models (LSMs) are often applied to predict the one-way coupling strength between surface soil moisture (SM) and latent heat (LH) flux. However, the ability of LSMs to accurately represent such coupling has not been adequately established. Likewise, the estimation of SM/LH coupling strength using ground-based observational data is potentially compromised by the impact of independent SM and LH measurements errors. Here we apply a new statistical technique to acquire estimates of one-way SM/LH coupling strength which are nonbiased in the presence of random error using a triple collocation approach based on leveraging the simultaneous availability of independent SM …


Using Swat To Simulate Crop Yields And Salinity Levels In The North Fork River Basin, Usa, Aaron R. Mittelstet, Daniel E. Storm, Art L. Stoecker Jan 2015

Using Swat To Simulate Crop Yields And Salinity Levels In The North Fork River Basin, Usa, Aaron R. Mittelstet, Daniel E. Storm, Art L. Stoecker

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Crop yields and salinity levels in the North Fork of the Red River (North Fork River) basin, located in southwestern Oklahoma and the Texas Panhandle, were analyzed based on the diverse climate in the region. Saline irrigation water is a major problem in the basin. The Elm Fork Creek flows through salt deposits, making the creek and its receiving stream, the North Fork River, too saline to use for irrigation. This greatly reduces the number of hectares that can be utilized for agricultural crops within the basin. A baseline SWAT model was setup, calibrated and validated to simulate streamflow and …


Identifying Intracellular Pdna Losses From A Model Of Nonviral Gene Delivery, Timothy Michael Martin, Beata Joanna Wysocki, Tadeusz Antoni Wysocki, Angela K. Pannier Jan 2015

Identifying Intracellular Pdna Losses From A Model Of Nonviral Gene Delivery, Timothy Michael Martin, Beata Joanna Wysocki, Tadeusz Antoni Wysocki, Angela K. Pannier

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Nonviral gene delivery systems are a type of nanocommunication system that transmit plasmid packets (i.e., pDNA packets) that are programmed at the nanoscale to biological systems at the microscopic cellular level. This engineered nanocommunication system suffers large pDNA losses during transmission of the genetically encoded information, preventing its use in biotechnological and medical applications. The pDNA losses largely remain uncharacterized, and the ramifications of reducing pDNA loss from newly designed gene delivery systems remain difficult to predict. Here, the pDNA losses during primary and secondary transmission chains were identified utilizing a MATLAB model employing queuing theory simulating delivery of pEGFPLuc …


Narrow Grass Hedges Reduce Tylosin And Associated Antimicrobial Resistance Genes In Agricultural Runoff, Bhavneet Soni, Shannon L. Bartelt-Hunt, Daniel D. Snow, John E. Gilley, Bryan Woodbury, David B. Marx, Xu Li Jan 2015

Narrow Grass Hedges Reduce Tylosin And Associated Antimicrobial Resistance Genes In Agricultural Runoff, Bhavneet Soni, Shannon L. Bartelt-Hunt, Daniel D. Snow, John E. Gilley, Bryan Woodbury, David B. Marx, Xu Li

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Agricultural runoff from areas receiving livestock manure can potentially contaminate surface water with antimicrobials and antimicrobial resistance genes (ARGs). The objective of this study was to investigate the effectiveness of narrow grass hedges (NGHs) on reducing the transport of antimicrobials and ARGs in runoff after land application of swine manure slurry. Plot-scale rainfall simulation tests were conducted on 0.75 m by 4.0 m plots designed to test three treatment factors: manure amendment (control plots receiving no manure vs. amended plots receiving manure based on 3 times N requirement), NGH (plots with a NGH vs. plots without a NGH), and rainfall …


Surface Energy Balance, Evapotranspiration, And Surface Coefficients During Non-Growing Season In A Maize-Soybean Cropping System, Lameck O. Odhiambo, Suat Irmak Jan 2015

Surface Energy Balance, Evapotranspiration, And Surface Coefficients During Non-Growing Season In A Maize-Soybean Cropping System, Lameck O. Odhiambo, Suat Irmak

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Surface energy balance components, including actual evapotranspiration (ET), were measured in a reducedtill maize-soybean field in south central Nebraska during three consecutive non-growing seasons (2006/2007, 2007/2008, and 2008/2009). The relative fractions of the energy balance components were compared across the non-growing seasons, and surface coefficients (Kc) were determined as a ratio of measured ET to estimated alfalfa (ETr) and grass (ETo) reference ET (ETref). The non-growing season following a maize crop had 25% to 35% more field surface covered with crop residue as compared to the non-growing seasons following soybean crops. Net …


Temporal Endogenous Gene Expression Profiles In Response To Lipid-Mediated Transfection, Timothy M. Martin, Sarah A. Plautz, Angela K. Pannier Jan 2015

Temporal Endogenous Gene Expression Profiles In Response To Lipid-Mediated Transfection, Timothy M. Martin, Sarah A. Plautz, Angela K. Pannier

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Background — Design of efficient nonviral gene delivery systems is limited as a result of the rudimentary understanding of the specific molecules and processes that facilitate DNA transfer.

Methods — Lipoplexes formed with Lipofectamine 2000 (LF2000) and plasmid-encoding green fluorescent protein (GFP) were delivered to the HEK 293T cell line. After treating cells with lipoplexes, HG-U133 Affymetrix microarrays were used to identify endogenous genes differentially expressed between treated and untreated cells (2 h exposure) or between flow-separated transfected cells (GFP+) and treated, untransfected cells (GFP–) at 8, 16 and 24 h after lipoplex treatment. Cell priming studies were conducted using …


Temporal Endogenous Gene Expression Profiles In Response To Polymer-Mediated Transfection And Profile Comparison To Lipid-Mediated Transfection, Timothy M. Martin, Sarah A. Plautz, Angela K. Pannier Jan 2015

Temporal Endogenous Gene Expression Profiles In Response To Polymer-Mediated Transfection And Profile Comparison To Lipid-Mediated Transfection, Timothy M. Martin, Sarah A. Plautz, Angela K. Pannier

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Background Design of efficient nonviral gene delivery systems is limited by the rudimentary understanding of specific molecules that facilitate transfection.

Methods Polyplexes using 25-kDa polyethylenimine (PEI) and plasmid encoding green fluorescent protein (GFP) were delivered to HEK 293T cells. After treating cells with polyplexes, microarrays were used to identify endogenous genes differentially expressed between treated and untreated cells (2 h of exposure) or between flow-separated transfected cells (GFP+) and treated, untransfected cells (GFP–) at 8, 16 and 24 h after lipoplex treatment. Cell priming studies were conducted using pharmacologic agents to alter endogenous levels of the identified differentially expressed genes …


Vulnerability Of Crops And Native Grasses To Summer Drying In The U.S. Southern Great Plains, Naama Raz-Yaseef, Dave P. Billesbach, Marc L. Fischer, Sebastien C. Biraud, Stacey A. Gunter, James A. Bradford, Margaret S. Torn Jan 2015

Vulnerability Of Crops And Native Grasses To Summer Drying In The U.S. Southern Great Plains, Naama Raz-Yaseef, Dave P. Billesbach, Marc L. Fischer, Sebastien C. Biraud, Stacey A. Gunter, James A. Bradford, Margaret S. Torn

Department of Agricultural and Biological Systems Engineering: Faculty Publications

The Southern Great Plains are characterized by a fine-scale mixture of different land-cover types, predominantly winter-wheat and grazed pasture, with relatively small areas of other crops, native prairie, and switchgrass. Recent droughts and predictions of increased drought in the Southern Great Plains, especially during the summer months, raise concern for these ecosystems. We measured ecosystem carbon and water fluxes with eddy-covariance systems over cultivated cropland for 10 years, and over lightly grazed prairie and new switchgrass fields for 2 years each. Growing-season precipitation showed the strongest control over net carbon uptake for all ecosystems, but with a variable effect: grasses …