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2021

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Full-Text Articles in Bioresource and Agricultural Engineering

Computational Prediction Of Mutagenesis In Glycine Max Rubisco Activase Monomer For Increased Thermal Stability, Catherine B. Emanuel, Hamza Haq '21, Vasanth Ramesh '21, Jaden Wang '21, Angela Ahrendt, Sarah Stainbrook Jun 2021

Computational Prediction Of Mutagenesis In Glycine Max Rubisco Activase Monomer For Increased Thermal Stability, Catherine B. Emanuel, Hamza Haq '21, Vasanth Ramesh '21, Jaden Wang '21, Angela Ahrendt, Sarah Stainbrook

Student Publications & Research

No abstract provided.


Modeling Vadose Zone Hydrology [Lecture Notes], Derek M. Heeren, Dean E. Eisenhauer Jun 2021

Modeling Vadose Zone Hydrology [Lecture Notes], Derek M. Heeren, Dean E. Eisenhauer

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Modeling Vadose Zone Hydrology is a graduate-level course offered biennially in the Department of Biological Systems Engineering. Topics included hydraulic properties of porous media, application of Darcy's Law in variably saturated media, hydrologic and transport processes in the vadose zone, and solution of steady and unsteady flow problems using numerical techniques. A graphical approach for characterizing vertical one-dimensional problems with energy head profiles was emphasized. Common one-dimensional flow and transport problems were solved analytically. The course was taught using a combination of lecture notes and PowerPoint presentations. The lecture notes from 2021, captured using the Microsoft Whiteboard app with a …


Uavs For Vegetation Monitoring: Overview And Recent Scientific Contributions, Ana I. De Castro, Yeyin Shi, Joe Mari Maja, Jose M. Peña May 2021

Uavs For Vegetation Monitoring: Overview And Recent Scientific Contributions, Ana I. De Castro, Yeyin Shi, Joe Mari Maja, Jose M. Peña

Department of Agricultural and Biological Systems Engineering: Faculty Publications

This paper reviewed a set of twenty-one original and innovative papers included in a special issue on UAVs for vegetation monitoring, which proposed new methods and techniques applied to diverse agricultural and forestry scenarios. Three general categories were considered: (1) sensors and vegetation indices used, (2) technological goals pursued, and (3) agroforestry applications. Some investigations focused on issues related to UAV flight operations, spatial resolution requirements, and computation and data analytics, while others studied the ability of UAVs for characterizing relevant vegetation features (mainly canopy cover and crop height) or for detecting different plant/crop stressors, such as nutrient content/deficiencies, water …


Early Detection Of Encroaching Woody Juniperus Virginiana And Its Classification In Multi-Species Forest Using Uas Imagery And Semantic Segmentation Algorithms, Lin Wang, Yuzhen Zhou, Qiao Hu, Zhenghong Tang, Yufeng Ge, Adam Smith, Tala Awada, Yeyin Shi May 2021

Early Detection Of Encroaching Woody Juniperus Virginiana And Its Classification In Multi-Species Forest Using Uas Imagery And Semantic Segmentation Algorithms, Lin Wang, Yuzhen Zhou, Qiao Hu, Zhenghong Tang, Yufeng Ge, Adam Smith, Tala Awada, Yeyin Shi

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Woody plant encroachment into grasslands ecosystems causes significantly ecological destruction and economic losses. Effective and efficient management largely benefits from accurate and timely detection of encroaching species at an early development stage. Recent advances in unmanned aircraft systems (UAS) enabled easier access to ultra-high spatial resolution images at a centimeter level, together with the latest machine learning based image segmentation algorithms, making it possible to detect small-sized individuals of target species at early development stage and identify them when mixed with other species. However, few studies have investigated the optimal practical spatial resolution of early encroaching species detection. Hence, we …


Exploration Of The Sludge Biodiesel Pathway, Zachary Christman May 2021

Exploration Of The Sludge Biodiesel Pathway, Zachary Christman

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

Wastewater sludge is an overlooked source of fat, oil, and grease (FOG) that could be converted into biodiesel. The United States produces about 8 million tons of sludge per year. The disposal cost for this amount of sludge is about 2 billion US dollars. The widespread availability and low cost of sludge compared to other biodiesel raw materials make it an economical choice for a renewable fuel. Using sludge as a raw material can produce 25 to 30 mg per gram of fatty acid methyl ester (FAME); the main component of biodiesel. Sludge biodiesel has the potential of transforming a …


Assessment And Improvement Of Performance Of Septic Systems In Cold Climates (Year 1), Stu Geza, Todd Menkhaus, Lianping Li, Galen Hoogestraat May 2021

Assessment And Improvement Of Performance Of Septic Systems In Cold Climates (Year 1), Stu Geza, Todd Menkhaus, Lianping Li, Galen Hoogestraat

SDWRI Publications and Reports

Onsite septic systems are used for wastewater treatment for households not connected to sewers. There is a concern about surface and groundwater pollution when effectiveness becomes limited due to soil texture, soil temperature, neighborhood density, and distance to water resources. The goal of this study was to assess treatment performance of local soils and selected treatment media. Lab-scale column experiments were conducted using wastewater from Wastewater Reclamation Facility in Rapid City. The experiments were conducted inside and outside the lab to evaluate the effect of temperature. The columns outside the lab were subject to seasonal variation in temperature. Moisture content, …


Economic And Ecosystem Impacts Of Gm Maize In South Africa, Kristiina Ala-Kokko May 2021

Economic And Ecosystem Impacts Of Gm Maize In South Africa, Kristiina Ala-Kokko

Graduate Theses and Dissertations

White maize in South Africa is the only staple crop produced on a widespread commercial basis for direct human consumption using genetically modified (GM) cultivars. Using a combined economic and environmental approach, we estimate the total welfare benefits attributable to GM white maize in South Africa for 2001-2018 are $694.7 million. Food security benefits attributable to GM white maize in South Africa also manifest through an average of 4.6 million additional white maize rations annually. To achieve these additional annual rations using conventional hybrid maize, the additional land required would range from 1,088 hectares in 2001 to 217,788 hectares in …


Light Intensity Control For Plc-Based Hydroponic Demonstration System, Christian Hitt May 2021

Light Intensity Control For Plc-Based Hydroponic Demonstration System, Christian Hitt

Biological and Agricultural Engineering Undergraduate Honors Theses

In order to demonstrate a skill set obtained through the University of Arkansas Biological Engineering, a group of students and I developed a hydroponic system where plants could be grown in a chamber. System parameters such as air quality, irrigation, and lighting were controlled by a Programmable Logic Computer (PLC) and an array of sensors and actuators. Each student focused on a certain aspect of this system, mine being the lighting. Developing this system involved researching the relationship between light intensity and plant growth, designing a system to suspend the lights above the growth chamber, and develop a system to …


Control System For Variable-Orifice Mechatronic Spray Nozzle For Regulation Of Application Rate And Droplet Size Spectra, Rodney Rohrer May 2021

Control System For Variable-Orifice Mechatronic Spray Nozzle For Regulation Of Application Rate And Droplet Size Spectra, Rodney Rohrer

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Traditional fixed-orifice spray nozzles are selected for flow rate and droplet spectra required for a given pesticide application. Although limited variation in flow can be achieved by adjusting system pressure, this can adversely affect spray quality. Other nozzle configurations, such as Pulse Width Modulated (PWM) nozzles or passive variable-orifice designs, are intended to maintain consistent droplet size and spray pattern as flow rate is changed but those too have limitations.

A variable-orifice nozzle modified by Luck (2012) can span multiple droplet spectra and offers independent control of flow and droplet size; however, an advanced control system must be developed to …


Sensor-Based Nitrogen Management On Non-Irrigated Corn Based Systems In Nebraska, Samantha L. Teten May 2021

Sensor-Based Nitrogen Management On Non-Irrigated Corn Based Systems In Nebraska, Samantha L. Teten

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Optimizing nitrogen (N) fertilizer applications in corn to reduce environmental impacts while maintaining producer profitability remains a challenge due to spatial and temporal variability in crop yield potential and soil N dynamics. In response to these challenges, active crop canopy sensors and imagery systems have been studied to test the performance of vegetative index-based N management, but adoption has been low. There is also a lack of field-scale research evaluating this technology in water-limiting environments.

The evaluation of two sensor-based N management techniques was completed at nine non-irrigated sites in Eastern Nebraska. The first sensor-based N management technique evaluated an …


Estimating Irrigation In Rice Fields With A Water Balance Approach, Kristen Trinh May 2021

Estimating Irrigation In Rice Fields With A Water Balance Approach, Kristen Trinh

Biological and Agricultural Engineering Undergraduate Honors Theses

Global food production must increase to meet the demand associated with increased population growth, so irrigation water use will continue to rise. Therefore, it is important to monitor water usage particularly when an irrigation flowmeter is unavailable. A field water balance was created for a selection of rice fields in East-central Arkansas under observation in 2018 and 2019. From those, irrigation inputs are deduced from the water balance alone. First, each field had sensors that collected water table level (WTL) data. Next, other water inputs and outputs such as precipitation and evapotranspiration (ET) were collected from two modeled sources. The …


Design Of Control Logic And The Human-Machine Interface For A Demonstration Plant Growth Chamber Implemented On A Programmable Logic Controller, Rachael Koehler May 2021

Design Of Control Logic And The Human-Machine Interface For A Demonstration Plant Growth Chamber Implemented On A Programmable Logic Controller, Rachael Koehler

Biological and Agricultural Engineering Undergraduate Honors Theses

This honors thesis covers the planning, development, and implementation of system controls and human-machine interface (HMI) for a demonstration plant growth chamber. The work is a continuation of an ongoing project to be used as an educational and recruiting tool manifesting the skills acquired from the Biological and Agricultural Engineering Department at the University of Arkansas’ College of Engineering. This work includes emergency controls, overall design interface, and controls for both the aeration and lighting subsystems of the growth chamber. Overall design interface controls established included development of two user modes, Administrator and Visitor. The Administrator user will have full …


When It Rains, It Pours: A Case Study Of Spatio-Temporal Variations In High-Intensity Precipitation Events In Arkansas, Deanna Mantooth-Hendrix May 2021

When It Rains, It Pours: A Case Study Of Spatio-Temporal Variations In High-Intensity Precipitation Events In Arkansas, Deanna Mantooth-Hendrix

Graduate Theses and Dissertations

Climate change is having an impact on weather systems and ecosystems worldwide. Glaciers are receding, oceans are acidifying, hurricanes are stronger, and extreme precipitation is increasing in frequency. Even with the wealth of data and knowledge about the threat of climate change, some places are slow to adapt because they think that the impact to their ecosystem will not be severe. The goal of this project was to determine if climate change is having an impact on extreme precipitation in the top urban areas of Arkansas. The major concern with an increase in extreme events in urban areas is flooding. …


Challenges And Opportunities In Precision Irrigation Decision-Support Systems For Center Pivots, Jingwen Zhang, Kaiyu Guan, Bin Peng, Chongya Jiang, Wang Zhou, Yi Yang, Ming Pan, Trenton Franz, Derek M. Heeren, Daran R. Rudnick, Olufemi P. Abimbola, Hyungsuk Kimm, Kelly Caylor, Stephen Good, Madhu Khanna, John Gates, Yaping Cai Apr 2021

Challenges And Opportunities In Precision Irrigation Decision-Support Systems For Center Pivots, Jingwen Zhang, Kaiyu Guan, Bin Peng, Chongya Jiang, Wang Zhou, Yi Yang, Ming Pan, Trenton Franz, Derek M. Heeren, Daran R. Rudnick, Olufemi P. Abimbola, Hyungsuk Kimm, Kelly Caylor, Stephen Good, Madhu Khanna, John Gates, Yaping Cai

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Irrigation is critical to sustain agricultural productivity in dry or semi-dry environments, and center pivots, due to their versatility and ruggedness, are the most widely used irrigation systems. To effectively use center pivot irrigation systems, producers require tools to support their decision-making on when and how much water to irrigate. However, currently producers make these decisions primarily based on experience and/or limited information of weather. Ineffective use of irrigation systems can lead to overuse of water resources, compromise crop productivity, and directly reduce producers’ economic return as well as bring negative impacts on environmental sustainability. In this paper, we surveyed …


Preclinical Development Of Single Walled Carbon Nanotube-Based Optical Biosensors, Eric M. Hofferber Apr 2021

Preclinical Development Of Single Walled Carbon Nanotube-Based Optical Biosensors, Eric M. Hofferber

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

High resolution, long-term monitoring of key biological analytes would improve patient outcomes by providing earlier detection of disease states and improved efficacy of treatment. One class of biosensors that have gained much attention in recent years are optical biosensors. Optical probes are attractive biosensors due to their noninvasive nature of detection, as certain light can pass through tissue, water, and blood. Single walled carbon nanotubes (SWNT) are a specific type of optical biosensor that fluoresce in the near infrared range of the electromagnetic spectrum and offer unparalleled spatial and temporal resolution. SWNT have been applied as biosensors in vitro, …


Detecting Recent Crop Phenology Dynamics In Corn And Soybean Cropping Systems Of Kentucky, Yanjun Yang, Bo Tao, Liang Liang, Yawen Huang, Christopher J. Matocha, Chad D. Lee, Michael Sama, Bassil El Masri, Wei Ren Apr 2021

Detecting Recent Crop Phenology Dynamics In Corn And Soybean Cropping Systems Of Kentucky, Yanjun Yang, Bo Tao, Liang Liang, Yawen Huang, Christopher J. Matocha, Chad D. Lee, Michael Sama, Bassil El Masri, Wei Ren

Geography Faculty Publications

Accurate phenological information is essential for monitoring crop development, predicting crop yield, and enhancing resilience to cope with climate change. This study employed a curve-change-based dynamic threshold approach on NDVI (Normalized Differential Vegetation Index) time series to detect the planting and harvesting dates for corn and soybean in Kentucky, a typical climatic transition zone, from 2000 to 2018. We compared satellite-based estimates with ground observations and performed trend analyses of crop phenological stages over the study period to analyze their relationships with climate change and crop yields. Our results showed that corn and soybean planting dates were delayed by 0.01 …


Evaluating Evapotranspiration Values In Rwanda Using The Fao-56 Pm, Turc, And Hargreaves-Samani Equations, Elizabeth Uwase Apr 2021

Evaluating Evapotranspiration Values In Rwanda Using The Fao-56 Pm, Turc, And Hargreaves-Samani Equations, Elizabeth Uwase

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Evapotranspiration (ET) is an important component of the hydrologic cycle and involves exchange of water between the surrounding water bodies, soil, crop surfaces, and the atmosphere. Therefore, this research was aimed at determining ET and its trend across Rwanda using climatic data measured at five sites. Equations were used to calculate ET using extra-terrestrial radiations, solar radiations, evapotranspiration using the FAO-56 guidelines - Turc method (1961) and Hargreaves-Samani (HS) method (1983). The obtained data from the weather stations were analyzed using the two methods and graphs were plotted for visualization. The average monthly reference evapotranspiration for both equations ranges from …


Comparison Of Three Commercial Automatic Boom Height Systems For Agricultural Sprayers, Travis A. Burgers, John D. Gaard, Brian J. Hyronimus Apr 2021

Comparison Of Three Commercial Automatic Boom Height Systems For Agricultural Sprayers, Travis A. Burgers, John D. Gaard, Brian J. Hyronimus

Mechanical Engineering Faculty Publications

Automatic boom height systems reduce the variability of agricultural sprayer boom height. Consistent boom height is important for three key reasons: to reduce uneven spray dispersion if the boom is too low, to reduce spray droplet drift if the boom is too high, and to reduce damage to the boom or crop if the boom is too low. No data is available comparing commercial boom height systems. Three leading North American automatic boom height systems were compared: John Deere BoomTrac Pro (System A), Raven AutoBoom® XRT (System B), and Norac UC5TM Passive Roll (System C) on a John Deere R4045 …


Water News, Spring 2021, Department Of Agriculture And Biosystems Engineering Apr 2021

Water News, Spring 2021, Department Of Agriculture And Biosystems Engineering

SDWRI Water News

Contents:
North Central Region tackle harmful algal blooms
Algae pull nutrients from swine facility manure, air
Study examines woodchip quality in bioreactors
Nonprofit joins battle to mitigate Lake Mitchell algal blooms


Field Evaluation Of Non-Contact Flow Measurement Device - Pid, Jack Evans, Stuart Styles Mar 2021

Field Evaluation Of Non-Contact Flow Measurement Device - Pid, Jack Evans, Stuart Styles

BioResource and Agricultural Engineering

The Irrigation Training and Research Center (ITRC) has analyzed the data from several non-contact volumetric flow meter models under various conditions. This testing was done with support from technical services contracts with the California Department of Water Resources (DWR) and the United States Bureau of Reclamation (USBR).


Field Evaluation Of Non-Contact Flow Measurement Devices - Gcid, Jack Evans, Stuart Styles Mar 2021

Field Evaluation Of Non-Contact Flow Measurement Devices - Gcid, Jack Evans, Stuart Styles

BioResource and Agricultural Engineering

The Irrigation Training and Research Center (ITRC) has analyzed the data from several non-contact volumetric flow meter models under various conditions. This testing was done with support from technical services contracts with the California Department of Water Resources (DWR) and the United States Bureau of Reclamation (USBR).


Utilizing Digital Image Processing And Two‑Source Energy Balance Model For The Estimation Of Evapotranspiration Of Dry Edible Beans In Western Nebraska, Wei‑Zhen Liang, Isabella Possignolo, Xin Qiao, Kendall Dejonge, Suat Irkmak, Derek M. Heeren, Daran Rudnick Mar 2021

Utilizing Digital Image Processing And Two‑Source Energy Balance Model For The Estimation Of Evapotranspiration Of Dry Edible Beans In Western Nebraska, Wei‑Zhen Liang, Isabella Possignolo, Xin Qiao, Kendall Dejonge, Suat Irkmak, Derek M. Heeren, Daran Rudnick

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Having an accurate yet simple method to estimate crop evapotranspiration ( ETC) is a vital component of reliable irrigation scheduling. In this study, two versions of the two-source energy balance (TSEB) model: the TSEB model with the Priestley–Taylor equation (TSEB-PT) and the Penman–Monteith equation (TSEB-PM), were used to estimate ETC of dry edible beans in western Nebraska. Compared with previous studies, this study is unique in that a Visual Basic software—Crop Canopy Image Analyzer (CCIA) was developed to process digitally captured RGB canopy images to obtain necessary canopy cover (CC) parameters for the TSEB models such as …


Unconventional Agriculture: An Exploration Of Hydroponics And Aquaponics And Their Role As A Solution To Food Scarcity, Kai Meacham Mar 2021

Unconventional Agriculture: An Exploration Of Hydroponics And Aquaponics And Their Role As A Solution To Food Scarcity, Kai Meacham

Honors Program: Senior Projects (Public)

Unconventional agriculture includes methods of farming that are defined by unique farming practices and a focus on sustainability. Unconventional agriculture can take many forms, including hydroponic systems and aquaponic systems. These two systems are unique in the sense that they are soilless methods of growing plants. Both of these systems require careful monitoring because they do not have soil to act as a buffer and help maintain normal levels. Though these two systems are very similar they have some key differences in how they function, which ultimately leads to differing advantages and disadvantages of both systems. Additionally, these systems have …


Field Evaluation Of Non-Contact Flow Measurement Device - Bcid, Jack Evans, Stuart Styles Mar 2021

Field Evaluation Of Non-Contact Flow Measurement Device - Bcid, Jack Evans, Stuart Styles

BioResource and Agricultural Engineering

The Irrigation Training and Research Center (ITRC) is currently testing several non-contact volumetric flow meter models under their technical services contracts with the California Department of Water Resources (DWR) and the United States Bureau of Reclamation (USBR). In April 2020, a Sommer RQ-30A non-contact flow meter was installed at Banta Carbona Irrigation Districts (BCID) Main Canal approximately 180 ft downstream of the discharge from Pumping Plant 1. The meter was mounted at midspan along a footbridge that crosses the throat of an ITRC designed subcritical contraction structure (see Figure 1). An existing SonTek Acoustic Doppler Flow Meter (ADFM) was installed …


Comparative Study Of Human Pluripotent Stem Cell-Derived Endothelial Cells In Hydrogel-Based Culture Systems, Zhanqi Wang, Fuxing Zuo, Qing Liu, Xuesheng Wu, Qian Du, Yuguo Lei, Zhangmin Wu, Haishuang Lin Mar 2021

Comparative Study Of Human Pluripotent Stem Cell-Derived Endothelial Cells In Hydrogel-Based Culture Systems, Zhanqi Wang, Fuxing Zuo, Qing Liu, Xuesheng Wu, Qian Du, Yuguo Lei, Zhangmin Wu, Haishuang Lin

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Human pluripotent stem cell (hPSC)-derived endothelial cells (ECs) are promising cell sources for drug discovery, tissue engineering, and studying or treating vascular diseases. However, hPSC-ECs derived from different culture methods display different phenotypes. Herein, we made a detailed comparative study of hPSC-ECs from three different culture systems (e.g., 2D, 3D PNIPAAm-PEG hydrogel, and 3D alginate hydrogel cultures) based on our previous reports. We expanded hPSCs and differentiated them into ECs in three culture systems. Both 3D hydrogel systems could mimic an in vivo physiologically relevant microenvironment to protect cells from shear force and prevent cell agglomeration, leading to a high …


Development Of An Internet Of Things (Iot) Enabled Novel Wireless Multi Sensor Network For Infield Crop Monitoring, Nipuna Chamara Mar 2021

Development Of An Internet Of Things (Iot) Enabled Novel Wireless Multi Sensor Network For Infield Crop Monitoring, Nipuna Chamara

Department of Agricultural and Biological Systems Engineering: Dissertations, Theses, and Student Research

Multispectral imaging systems on satellite, aerial, and ground platforms are used commonly to monitor in-field crops in precision agriculture by farmers and researchers. Limited spatial and temporal resolution and weather dependence of the data collection are two main disadvantages of these methods. In-field sensor networks can continuously monitor environmental and plant physiological parameters by leveraging low-power computation and long-range communication technologies. We built and tested a novel sensor network equipped with soil moisture, multispectral and RGB imaging sensors in an experimental soybean field at Eastern Nebraska Research and Extension Center, NE, USA. 10 down-looking and 1 up-looking sensor node were …


Biodegradable Cellulose Film Prepared From Banana Pseudo-Stem Using An Ionic Liquid For Mango Preservation, Binling Ai, Lili Zheng, Wenqi Li, Xiaoyan Zheng, Yang Yang, Dao Xiao, Jian Shi, Zhanwu Sheng Feb 2021

Biodegradable Cellulose Film Prepared From Banana Pseudo-Stem Using An Ionic Liquid For Mango Preservation, Binling Ai, Lili Zheng, Wenqi Li, Xiaoyan Zheng, Yang Yang, Dao Xiao, Jian Shi, Zhanwu Sheng

Biosystems and Agricultural Engineering Faculty Publications

The excessive use and disposal of plastic packaging materials have drawn increasing concerns from the society because of the detrimental effect on environment and ecosystems. As the most widely used fruit packing material, polyethylene (PE) film is not suitable for long-term preservation of some tropical fruits, such as mangos, due to its inferior gas permeability. Cellulose based film can be made from renewable resources and is biodegradable and environmental-friendly, which makes it a promising alternative to PE as a packaging material. In this study, cellulose film synthesized from delignified banana stem fibers via an ionic liquid 1-Allyl-3-methylimidazolium chloride ([AMIm][Cl]) were …


Determination Of Vadose Zone And Saturated Zone Nitrate Lag Times Using Long-Term Groundwater Monitoring Data And Statistical Machine Learning, Martin J. Wells, Troy E. Gilmore, Natalie Nelson, John K. Bohlke Feb 2021

Determination Of Vadose Zone And Saturated Zone Nitrate Lag Times Using Long-Term Groundwater Monitoring Data And Statistical Machine Learning, Martin J. Wells, Troy E. Gilmore, Natalie Nelson, John K. Bohlke

Department of Agricultural and Biological Systems Engineering: Faculty Publications

In this study, we explored the use of statistical machine learning and long-term groundwater nitrate monitoring data to estimate vadose zone and saturated zone lag times in an irrigated alluvial agricultural setting. Unlike most previous statistical machine learning studies that sought to predict groundwater nitrate concentrations within aquifers, the focus of this study was to leverage available groundwater nitrate concentrations and other environmental variables to determine mean regional vertical velocities (transport rates) of water and solutes in the vadose zone and saturated zone (3.50 and 3.75 m yr−1 , respectively). The statistical machine learning results are consistent with two primary …


Role Of Nadþ In Regulating Cellular And Metabolic Signaling Pathways, Sara Amjad, Sabah Nisar, Ajaz A. Bhat, Ab Rauf Shah, Michael P. Frenneaux, Khalid Fakhro, Mohammad Haris, Ravinder Reddy, Zoltan Patay, Joseph Baur, Puneet Bagga Feb 2021

Role Of Nadþ In Regulating Cellular And Metabolic Signaling Pathways, Sara Amjad, Sabah Nisar, Ajaz A. Bhat, Ab Rauf Shah, Michael P. Frenneaux, Khalid Fakhro, Mohammad Haris, Ravinder Reddy, Zoltan Patay, Joseph Baur, Puneet Bagga

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Background: Nicotinamide adenine dinucleotide (NAD+), a critical coenzyme present in every living cell, is involved in a myriad of metabolic processes associated with cellular bioenergetics. For this reason, NAD+ is often studied in the context of aging, cancer, and neurodegenerative and metabolic disorders.

Scope of review: Cellular NAD+ depletion is associated with compromised adaptive cellular stress responses, impaired neuronal plasticity, impaired DNA repair, and cellular senescence. Increasing evidence has shown the efficacy of boosting NAD+ levels using NAD+ precursors in various diseases. This review provides a comprehensive understanding into the role of NAD+ …


Historical Contingency In Microbial Resilience To Hydrologic Perturbations, Hyun-Seob Song, James C. Stegen, Emily B. Graham, Timothy D. Scheibe Feb 2021

Historical Contingency In Microbial Resilience To Hydrologic Perturbations, Hyun-Seob Song, James C. Stegen, Emily B. Graham, Timothy D. Scheibe

Department of Agricultural and Biological Systems Engineering: Faculty Publications

Development of reliable biogeochemical models requires a mechanistic consideration of microbial interactions with hydrology. Microbial response to and its recovery after hydrologic perturbations (i.e., resilience) is a critical component to understand in this regard, but generally difficult to predict because the impacts of future events can be dependent on the history of perturbations (i.e., historical contingency). Fundamental issues underlying this phenomenon include how microbial resilience to hydrologic perturbations is influenced by historical contingency and how their relationships vary depending on the characteristics of microbial functions. To answer these questions, we considered a simple microbial community composed of two species that …