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Full-Text Articles in Life Sciences
Determination Of Tobacco Alkaloid Enantiomers Using Reversed Phase Uplc/Ms/Ms, Huihua Ji, Ying Wu, Franklin Fannin, Lowell P. Bush
Determination Of Tobacco Alkaloid Enantiomers Using Reversed Phase Uplc/Ms/Ms, Huihua Ji, Ying Wu, Franklin Fannin, Lowell P. Bush
Kentucky Tobacco Research and Development Center Faculty Publications
Nʹ-Nitrosonornicotine (NNN), a carcinogenic tobacco-specific Nʹ-nitrosamine (TSNA), is on the FDA list of harmful and potentially harmful constituents (HPHCs). Nornicotine, a product of the demethylation of nicotine, is the immediate alkaloid precursor for NNN formation. Nicotine, nornicotine and NNN are optically active. The accumulation of the isomers of nicotine, nornicotine, and NNN impacts their biological activity. In this paper, we report the determination of tobacco alkaloid enantiomers (including nicotine, nornicotine, anabasine, and anatabine) in samples of different tobacco lines using a reversed phase ultra-performance liquid chromatography-tandem mass spectrometer (UPLC/MS/MS) method. Current method demonstates excellent detection capability for all alkaloid enantiomers, …
Quantifying Plant Soluble Protein And Digestible Carbohydrate Content, Using Corn (Zea Mays) As An Exemplar, Carrie A. Deans, Gregory A. Sword, Paul A. Lenhart, Eric Burkness, William D. Hutchison, Spencer T. Behmer
Quantifying Plant Soluble Protein And Digestible Carbohydrate Content, Using Corn (Zea Mays) As An Exemplar, Carrie A. Deans, Gregory A. Sword, Paul A. Lenhart, Eric Burkness, William D. Hutchison, Spencer T. Behmer
Entomology Faculty Publications
Elemental data are commonly used to infer plant quality as a resource to herbivores. However, the ubiquity of carbon in biomolecules, the presence of nitrogen-containing plant defensive compounds, and variation in species-specific correlations between nitrogen and plant protein content all limit the accuracy of these inferences. Additionally, research focused on plant and/or herbivore physiology require a level of accuracy that is not achieved using generalized correlations. The methods presented here offer researchers a clear and rapid protocol for directly measuring plant soluble proteins and digestible carbohydrates, the two plant macronutrients most closely tied to animal physiological performance. The protocols combine …
Assessing Intra-Event Phosphorus Dynamics In Drainage Water Using Phosphate Stable Oxygen Isotopes, William Ford Iii, Mark R. Williams, Megan B. Young, Kevin W. King, Eric Fischer
Assessing Intra-Event Phosphorus Dynamics In Drainage Water Using Phosphate Stable Oxygen Isotopes, William Ford Iii, Mark R. Williams, Megan B. Young, Kevin W. King, Eric Fischer
Biosystems and Agricultural Engineering Faculty Publications
Quantifying fluxes and pathways of dissolved reactive phosphorus (DRP) in tile-drained landscapes has been hampered by a lack of measurements that are sensitive to P fate and transport processes. One potential tool to help understand these dynamics is the oxygen isotope signature of phosphate (δ18OPO4); however, its potential benefits and limitations are not well understood for intra-event dynamics at the field scale. The objectives of this study were to quantify intra-event variability of δ18OPO4 signatures in tile drainage water and assess the efficacy of δ18OPO4 to elucidate mechanisms and flow …
Organic Solvent Exposure And Depressive Symptoms Among Licensed Pesticide Applicators In The Agricultural Health Study, Miriam Siegel, Sarah E. Starks, Wayne T. Sanderson, Freya Kamel, Jane A. Hoppin, Fred Gerr
Organic Solvent Exposure And Depressive Symptoms Among Licensed Pesticide Applicators In The Agricultural Health Study, Miriam Siegel, Sarah E. Starks, Wayne T. Sanderson, Freya Kamel, Jane A. Hoppin, Fred Gerr
Epidemiology and Environmental Health Faculty Publications
Purpose
Although organic solvents are often used in agricultural operations, neurotoxic effects of solvent exposure have not been extensively studied among farmers. The current analysis examined associations between questionnaire-based metrics of organic solvent exposure and depressive symptoms among farmers.
Methods
Results from 692 male Agricultural Health Study participants were analyzed. Solvent type and exposure duration were assessed by questionnaire. An “ever-use” variable and years of use categories were constructed for exposure to gasoline, paint/lacquer thinner, petroleum distillates, and any solvent. Depressive symptoms were ascertained with the Center for Epidemiologic Studies Depression Scale (CES-D); scores were analyzed separately as continuous (0–60) …
Potential For Crop Residue To Restrict Herbicide Movement In Surface From Water Corn And Soybean Fields, William W. Witt
Potential For Crop Residue To Restrict Herbicide Movement In Surface From Water Corn And Soybean Fields, William W. Witt
KWRRI Research Reports
As no-tillage and other conservation tillage practices continue to increase, it is important to have knowledge of herbicide adsorption on crop residue with regard to the potential for the herbicide to be removed from the residue and move with runoff water from the field into nearby surface waters. Previous research had compared herbicide adsorption to various residues, but it was difficult to make comparisons among these studies because the residues were from different crops or the amount of residue decomposition was different. The amount of "weathering" or "aging" of the residue at the time of herbicide treatment could alter the …
Use Of Riparian Vegetated Filter Strips To Reduce Nitrate And Fecal Contamination In Surface Water, Mark S. Coyne, Robert L. Blevins, Rebecca A. Gilfillen
Use Of Riparian Vegetated Filter Strips To Reduce Nitrate And Fecal Contamination In Surface Water, Mark S. Coyne, Robert L. Blevins, Rebecca A. Gilfillen
KWRRI Research Reports
This research assessed fecal bacteria trapping in surface runoff by grass filters and their potential to enhance NO3- removal via denitrification. Grass filter strips 9.0 m long trapped over 99% of the soil in surface runoff in 1992. Fecal coliform removal was less than 75%. In 1993, 9.0 and 4.5 m grass filter strips trapped 99 and 95% of the sediment, respectively. Fecal coliform trapping efficiency was 90% in 9.0 m grass filters and 75% in 4.5 m filters. Fecal streptococci trapping efficiency was 77% in 9.0 m grass filters and only 56% in 4.5 m filters. Fecal …