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A normalized difference vegetation index (NDVI) sensor can be used for nondestructively assessing the nitrogen (N) status of crops. When deployed as a mobile ground-based sensor for variable-rate cropping applications, its readings can be influenced by the irregular or sparse canopy coverages of the ground surface. The soil and ground stubble backgrounds that are periodically exposed within the sensor’s view will generate erroneous readings. The objective of this research was to develop an algorithm that improves an NDVI-based instrumentation system’s ability to discriminate between cotton plant biomass and the ground surface, thereby providing a more accurate N status for the crop. The research focused on N concentration assessment as a measure of N status; hence, eliminating the exposed soil background became essential. Algorithms were developed to correct the errors resulting from irregular cotton populations. A statistical analysis of field data taken using manipulated crop populations highlighted two effective algorithms.

Cardiovascular disease (CVD) is a leading cause of mortality in developed countries and is a frequent comorbidity of numerous metabolic and inflammatory diseases that demands more effective therapies. Dyslipidemias are a classical risk factor for CVD, but emerging alternative functions of lipoproteins have implicated them in novel narratives for the pathophysiology of many diseases that warrant further study. Our lab has identified functional, intercellular gene regulatory networks mediated by extracellular transport of microRNAs (miRNA) by lipoproteins. Here, we quantified the landscape of small RNAs (sRNA) on human and animal lipoproteins and discovered that most lipoprotein-sRNAs are derived from microorganisms of multiple kingdoms, primarily bacteria. Based on these observations, our over-arching hypothesis is that lipoprotein-sRNA signatures are shaped by the interface of host tissues with resident, environmental and dietary microbiota, and likely participate in unique gene regulation networks that contribute to complex (patho)physiological traits. To investigate this hypothesis, we developed a sRNA-sequencing analysis pipeline that identifies and quantifies both host and non-host sRNAs. Using this bioinformatic tool, we identified and validated a number of lipoprotein-sRNAs derived from bacteria that are similar in size to miRNAs with identical seed regions, termed Doppelganger (Dopl)-miRNAs. We hypothesized that mucosal immunity contributes to non-host sRNAs on lipoproteins, as mucosal linings are a primary interface between host tissues and microorganisms. To this end, we investigated the lipoprotein-sRNAs of mice lacking the polymeric immunoglobulin receptor (pIgR -/- ), which is devoid of polymeric IgA and IgM at mucosal linings and models human respiratory and intestinal diseases. We report a global increase in lipoprotein-miRNAs juxtaposed with a profound decrease in bacterial sRNA and Dopl-miRNAs from specific taxa. This work unfurls novel links between microbiota, mucosal immunity, and lipoprotein-sRNA gene networks and emphasizes the potential for novel nucleic-acid based therapeutics.

Chronic kidney disease (CKD) subjects have an increased risk of developing cardiovascular disease, namely atherosclerosis. Endothelial dysfunction and inflammation are linked to the development of these diseases and recent work has identified a number of microRNAs (miRNAs) involved in these pathologies. As such, endothelial miRNAs are potential novel therapeutic targets to prevent and treat atherosclerosis. This study identified elevated aortic endothelial miR-92a-3p and miR-489-3p levels in a mouse model of CKD-associated atherosclerosis, Apoe -/- mice with 5/6 nephrectomy. A combinatorial miRNA inhibition strategy resulted in the loss of both miR-92a-3p and miR-489-3p in the endothelium and significantly reduced the atherosclerotic lesion area by 33%. Total RNA sequencing of the aortic endothelium identified many altered genetic pathways and metabolic processes in response to in vivo miRNA loss-of-function, including inflammation, phospholipid metabolism, and protein degradation pathways. Results suggest that the reduction in atherosclerosis levels were not likely to be linked to alterations in plasma cholesterol levels or kidney function since these physiological parameters were not improved upon miRNA inhibition. Nevertheless, novel miRNA targets were identified to be significantly elevated in the aortic endothelium that may reduce inflammation leading to the improved physiological phenotype. Fam220a , a negative regulator of signal transducer and activator of transcription 3 (STAT3) phosphorylation, mRNA levels were significantly reduced in CKD-atherogenic mice compared to controls, but miRNA inhibition in vivo blocked the Fam220a repression. Moreover, gene reporter (luciferase) assays with site-directed mutagenesis confirmed FAM220A as a direct target of miR-92a-3p. Furthermore, FAM220A mRNA levels were repressed in human coronary artery endothelial cells (HCAEC) with miR-92a-3p over-expression, which resulted in increased phosphorylation of STAT3. Collectively, these results suggest that endothelial miR-92a-3p and miR-489-3p are novel therapeutic targets to treat CKD-associated atherosclerosis.

Cutting-propagated ‘Alice’ oakleaf hydrangea (Hydrangea quercifolia Bartr.) often produces a few vigorous branches with apical dominance, thus suppressing growth of other branches. As a result, the maturing canopy is sparse and develops asymmetrically, rendering plants unappealing to customers. For this reason, growers prune or apply plant growth regulators (PGRs) to encourage more branching, thereby producing a more desirable product. Propagation through tissue culture may provide another option to increase branching as an outcome of habituation. Habituation occurs when plant cultures continue to respond to a hormone that is no longer being supplied and, in turn, frequently leads to more branching. We evaluated oakleaf hydrangea growth as affected by propagation technique [tissue-cultured (TC) and cutting-propagated (CUT)] and PGR (cyclanilide and benzyladenine) application during container production. Nontreated TC plants had more branches longer than 15.2 cm (6 in) compared to nontreated CUT plants in 2008, although not in 2010. In both years, single applications of cyclanilide did not affect total branch number but two applications increased total branch number compared to nontreated plants, averaged over propagation technique. Plants treated with benzyladenine had similar or fewer total branches compared with nontreated, hand-pruned, and cyclanilide-treated plants (one or two treatments). Propagation technique did not consistently influence response to PGRs.

In this work, new composite electrodes were developed and characterized for possible use in energy storage devices such as electrochemical capacitors (ECC). The electrodes were assembled using nanographite and, poly(3,4- ethylenedioxithiophene) (PEDOT) doped by polystyrenesulfonic acid (PSS), sodium dodecylsulfate (SDS), and dodecylbenzene sulfonic acid (DBSA). The electrodes presented conductivity in the order of X10-1 S cm-1 , which allowed the electrochemical deposition of PEDOT in aqueous medium. The composite electrodes were evaluated by cyclic voltammetry, impedance spectroscopy, galvanodynamic technique, and electron microscopy. The evaluation of the composite electrodes indicated improvements both in material properties and processability. For comparison purposes, a second set of composite electrodes was prepared. In this case, the chemically synthesized PEDOT was deposited by spray coating technique. The results from this comparison indicates that, is feasible to develop composite capacitors, by using the materials proposed in this thesis, due to the improvement of the electrochemical properties.