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Full-Text Articles in Life Sciences

Classifying Reflectance Targets Under Ambient Light Conditions Using Passive Spectral Measurements, Ali Hamidisepehr, Michael P. Sama, Joseph S. Dvorak, Ole O. Wendroth, Michael D. Montross Sep 2020

Classifying Reflectance Targets Under Ambient Light Conditions Using Passive Spectral Measurements, Ali Hamidisepehr, Michael P. Sama, Joseph S. Dvorak, Ole O. Wendroth, Michael D. Montross

Biosystems and Agricultural Engineering Faculty Publications

Collecting remotely sensed spectral data under varying ambient light conditions is challenging. The objective of this study was to test the ability to classify grayscale targets observed by portable spectrometers under varying ambient light conditions. Two sets of spectrometers covering ultraviolet (UV), visible (VIS), and near−infrared (NIR) wavelengths were instrumented using an embedded computer. One set was uncalibrated and used to measure the raw intensity of light reflected from a target. The other set was calibrated and used to measure downwelling irradiance. Three ambient−light compensation methods that successively built upon each other were investigated. The default method used a variable …


Simulated Biological Fluid Exposure Changes Nanoceria’S Surface Properties But Not Its Biological Response, Robert A. Yokel, Matthew L. Hancock, Benjamin Cherian, Alexandra J. Brooks, Marsha L. Ensor, Hemendra J. Vekaria, Patrick G. Sullivan, Eric A. Grulke Nov 2019

Simulated Biological Fluid Exposure Changes Nanoceria’S Surface Properties But Not Its Biological Response, Robert A. Yokel, Matthew L. Hancock, Benjamin Cherian, Alexandra J. Brooks, Marsha L. Ensor, Hemendra J. Vekaria, Patrick G. Sullivan, Eric A. Grulke

Pharmaceutical Sciences Faculty Publications

Nanoscale cerium dioxide (nanoceria) has industrial applications, capitalizing on its catalytic, abrasive, and energy storage properties. It auto-catalytically cycles between Ce3+ and Ce4+, giving it pro-and anti-oxidative properties. The latter mediates beneficial effects in models of diseases that have oxidative stress/inflammation components. Engineered nanoparticles become coated after body fluid exposure, creating a corona, which can greatly influence their fate and effects. Very little has been reported about nanoceria surface changes and biological effects after pulmonary or gastrointestinal fluid exposure. The study objective was to address the hypothesis that simulated biological fluid (SBF) exposure changes nanoceria’s surface properties …


A Method For Reflectance Index Wavelength Selection From Moisture-Controlled Soil And Crop Residue Samples, Ali Hamidisepehr, Michael P. Sama, Aaron P. Turner, Ole O. Wendroth Jan 2017

A Method For Reflectance Index Wavelength Selection From Moisture-Controlled Soil And Crop Residue Samples, Ali Hamidisepehr, Michael P. Sama, Aaron P. Turner, Ole O. Wendroth

Biosystems and Agricultural Engineering Faculty Publications

Reflectance indices are a method for reducing the dimensionality of spectral measurements used to quantify material properties. Choosing the optimal wavelengths for developing an index based on a given material and property of interest is made difficult by the large number of wavelengths typically available to choose from and the lack of homogeneity when remotely sensing agricultural materials. This study aimed to determine the feasibility of using a low-cost method for sensing the moisture content of background materials in traditional crop remote sensing. Moisture-controlled soil and wheat stalk residue samples were measured at varying heights using a reflectance probe connected …


Monitoring Yogurt Culture Fermentation And Predicting Fermentation Endpoint With Fluorescence Spectroscopy, Timothey P. Mains, Frederick Alan Payne, Michael P. Sama Jan 2016

Monitoring Yogurt Culture Fermentation And Predicting Fermentation Endpoint With Fluorescence Spectroscopy, Timothey P. Mains, Frederick Alan Payne, Michael P. Sama

Biosystems and Agricultural Engineering Faculty Publications

Determination of the endpoint of yogurt culture fermentation is a process parameter that could benefit from automation. The feasibility of using a fluorescence sensor technology based on 280 nm excitation and 350 nm emission to predict the endpoint of yogurt culture fermentation was investigated and compared with the endpoint prediction from a near-infrared (880 nm) light backscatter sensor. Yogurt cultures with three levels of milk solids (8%, 10%, and 12%) and three temperatures (40°C, 43°C, and 46°C) were tested with three replications in a 3 x 3 factorial design (n = 27). Prediction models were developed for each optical measurement …


Rat Brain Pro-Oxidant Effects Of Peripherally Administered 5 Nm Ceria 30 Days After Exposure, Sarita S. Hardas, Rukhsana Sultana, Govind Warrier, Mo Dan, Rebecca L. Florence, Peng Wu, Eric A. Grulke, Michael T. Tseng, Jason M. Unrine, Uschi M. Graham, Robert A. Yokel, D. Allan Butterfield Oct 2012

Rat Brain Pro-Oxidant Effects Of Peripherally Administered 5 Nm Ceria 30 Days After Exposure, Sarita S. Hardas, Rukhsana Sultana, Govind Warrier, Mo Dan, Rebecca L. Florence, Peng Wu, Eric A. Grulke, Michael T. Tseng, Jason M. Unrine, Uschi M. Graham, Robert A. Yokel, D. Allan Butterfield

Chemistry Faculty Publications

The objective of this study was to determine the residual pro-or anti-oxidant effects in rat brain 30 days after systemic administration of a 5 nm citrate-stabilized ceria dispersion. A ∼4% aqueous ceria dispersion was iv-infused (0 or 85 mg/kg) into rats which were terminated 30 days later. Ceria concentration, localization, and chemical speciation in the brain was assessed by inductively coupled plasma mass spectrometry (ICP-MS), light and electron microscopy (EM), and electron energy loss spectroscopy (EELS), respectively. Pro- or anti-oxidant effects were evaluated by measuring levels of protein carbonyls (PC), 3-nitrotyrosine (3NT), and protein-bound-4-hydroxy-2-trans-nonenal (HNE) in the hippocampus, cortex, and …