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Evaluation of Screening Techniques for Woody Plant Herbicide DevelopmentBlair, Mitchell 24 May 2004 (has links)
Woody plant herbicide screening techniques were evaluated in an attempt to expedite the screening process and decrease amounts of herbicide active ingredient required. Rapid greenhouse screening of woody plant seedlings was performed in less than six months while rapid seed screening was performed in less than twenty days. A traditional field screen, requiring ten months, was performed for comparison purposes. Leaf area – biomass ratios were also examined for their influence on herbicide efficacy. Linear regressions were performed using traditional field screen data as the dependent variable and rapid screening technique data as the independent data.
Rapid screens using triclopyr produced more statistically significant regressions compared to those involving imazapyr. Significant regressions were produced that could predict field response of several species using both herbicides and either rapid screening technique. This indicated that rapid screening techniques could determine herbicide efficacy and/or species spectrum of control in much less time with much less herbicide. Rapid seed screens could estimate species spectrum within five days after treatment. The rapid greenhouse screen and rapid seed screen techniques can provide woody plant herbicide developers initial efficacy and spectrum of control data in a cost- and time- effective manner.
Testing showed that as woody plants mature from seedling to sapling, there is a decrease in the leaf area — total aboveground biomass ratio. The decrease in this ratio consistently decreased efficacy of both imazapyr and triclopyr at the lower active ingredient rates. Seedlings with the higher leaf area – biomass ratio had, on the average, higher efficacy response rates to herbicide treatments. / Master of Science
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An investigation of some electrochemical characteristics of enzyme based disposable biosensors and other relevant electrodesZhou, Dao Min January 1994 (has links)
No description available.
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Interaction design for electronic product design using virtual simulationsSharp, Jonathan Anthony January 1997 (has links)
No description available.
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Identification, quantification and assessment of oestrogenic chemicals in domestic sewage-treatment work effluentsRoutledge, Edwin John January 1997 (has links)
No description available.
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The genetics of susceptibility to leprosyMeisner, Sarah January 1999 (has links)
No description available.
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Scam KingKopchick, Laura A. (Laura Ann) 05 1900 (has links)
"Scam King" is a full-length feature screenplay and follows standard script format. The idea behind "Scam King" came originally from the James Joyce short story "Two Gallants" in Dubliners. "Scam King" is, however, not an adaption of Joyce's story, but rather was inspired by the gaps in his story pertaining to the characters' way of life on the street.
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The Virtue Screen: An 18th Century Biombo at Virginia HouseCarrera, Jacqueline 01 January 2006 (has links)
An eighteenth century Mexican folding screen or biombo is located at Virginia House in Richmond, Virginia. A similar three-paneled screen is also located at this site. Upon seeing the similarities between each screen I concluded that the seven panels were at one point a part of one folding screen. The top sections of these folding screens show emblems that depict images of virtues and vices. The source of the emblems on the Virtue Screen is Otto Van Veen's Homtii Emblemata. The text on the screen is taken from a Spanish translation of the Horatii Emblemata entitled the Theatro Moral de toda la Philosophia de los Antiguos y Modernos. This thesis will examine each emblem in a panel-by-panel discussion as well as the iconography found throughout the screen. It will also provide a brief history of the folding screen with its origins in Asia and a comparison of similar screens that have been discovered in the Western Hemisphere.
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Genetic and molecular investigations of Drosophila Notch signalingShalaby, Nevine January 2009 (has links)
Thesis advisor: Marc A. T. Muskavitch / Notch signaling is an evolutionarily conserved developmental pathway regulated by two classes of transmembrane proteins: the Notch receptors and the Delta/Serrate/LAG-2 (DSL) ligands. Notch and DSL ligands mediate cell-cell communication that results in a downstream signaling cascade that affects many aspects of metazoan development. Additional regulatory mechanisms that affect Notch signaling are being discovered continuously, and recent findings highlight the importance of endocytosis, ubiquitylation and subcellular trafficking as essential requirements for proper signaling. In order to obtain further insights into the regulation of Notch signaling, I took a two-fold approach, combining genetic and molecular techniques in <italic>Drosophila</italic>. First, I took part in a large-scale transposon-based screen in the developing <italic>Drosophila</italic> eye to identify additional genes involved in the pathway. We screened 10,447 transposon lines from the Exelixis collection for modifiers of cell fate alterations caused by overexpression of Delta, and we identified 170 distinct modifier lines that may affect up to 274 genes. I further analyzed a previously uncharacterized gene, which we have named <italic>Amun</italic>, and showed that it localizes to the nucleus and contains a putative DNA glycosylase domain. Further analyses of Amun reveal that altered levels of Amun function interfere with cell fate specification during eye and sensory organ development. Second, to investigate structural requirements for ubiquitylation of Delta, I analyzed four individual lysine residues in the Delta intracellular domain, and assessed their necessity for Delta signaling activity. I find that a conserved residue, DeltaK742, is essential for Notch signaling in the <italic>Drosophila</italic> imaginal wing disc and is apparently required for ubiquitylation of Delta by the E3 ubiquitin ligase, Mind bomb1 (one of two E3 ubiquitin ligases required for Delta signaling activity). Taken together, the findings from this thesis research contribute to the advancement of our understanding of different aspects of Notch signaling and Notch-mediated development. / Thesis (PhD) — Boston College, 2009. / Submitted to: Boston College. Graduate School of Arts and Sciences. / Discipline: Biology.
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Novel electrochemical methods for acidity monitoring : theory, design and applicationGao, Xiangming January 2019 (has links)
This thesis reports the design and development of novel voltammetric pH sensors for buffered, low-buffered and unbuffered media. pH sensors in stagnant and hydrodynamic environments were designed and developed for performing measurements using square wave voltammetry. Chapter 1 introduces the motivation of this project, the current development of electrochemical sensors, and the basic theory and techniques of electrochemistry concerned within the thesis. The existing development of carbon-based electrochemical sensors and the application of screen-printing technology in sensor fabrication are highlighted. Chapter 2 introduces the screen-printing technology and the fundamental methods of numerical simulation. In addition, reagents, equipment and software packages used in the thesis are listed in this chapter. In Chapter 3, a novel design of quinone derivative-based pH probes is presented for the application in stagnant weakly buffered media (< 1mM), based on previous studies of quinone compounds in buffered media. The results from the weakly buffered system is consistent with the results in buffered systems. To further extend the application of this design in unbuffered media, a numerical model of a pH-sensitive redox particle immobilised on an electrode was developed, which predicted that the accumulation of hydrogen ions near the electrode is the possible limiting factor for the performance of this design in unbuffered media. To develop a pH-monitoring technology for unbuffered media, Chapter 4 reports on the design, fabrication and testing of different electropolymerised-phenol derivative modified electrodes, which overcome the limitation of hydrogen ions accumulation. The results revealed that 2-(methylthio)phenol graphite resin electrodes have high accuracy (ca. 1% error) in unbuffered media, benchmarked by a commercial glass pH meter. This is the first detailed study on the v application of the economical and scalable technology in pH sensing in unbuffered environment. Chapter 5 presents a unique design of electrochemical pH sensors, free from the need to use a glass reference electrode. This design integrates a pH indicator and an internal reference electrode. Different designs of ferrocene screen-printed electrodes were tested as the internal reference electrode. The nafion-coated ferrocene screen-printed electrode showed stable peak potential in a wide pH range (pH 1 - 12) with good durability (stable in 500+ cycles of test). It was then cross connected with an alizarin electrode, forming the pH sensor free from a glass reference electrode. Chapter 6 describes novel designs of hydrodynamic pH sensors. The design of a microfluidic pH sensor modified by poly-sodium salicylate was firstly demonstrated. The sensor showed a Nernstian response in a wide pH range and, in hydrodynamic conditions, provided improved accuracy in unbuffered media compared to the stagnant state. For more convenient measurements, a novel rocking disc electrode was studied for pH sensing, modified with alizarin and poly-salicylic acid as pH indicators. The electrodes modified by both chemicals showed a Nernstian response in buffered media and the highest accuracy in unbuffered media was reached at 50 rpm.
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Effect of Genetic Background Combined with Excessive Media Screen Time on Markers of Cardiovascular Risk in United States Youth Aged Newborn to 20 YearsMoroni, Maria 01 January 2016 (has links)
Time with media screens (television, computers, videogames, cell phones, and tablets) is the primary activity of youth, second only to sleeping, and represents a major risk factor for cardiovascular diseases (CVD). Additionally, the populations with highest rates of screen time are also those most at risk of CVD from genetic predisposition (i.e., Blacks, Hispanics). The purpose of this descriptive, correlational study, based on cross-sectional analysis of archived data from the 2009 - 2010 NHANES for United States youth, newborn to 20 years old, was to determine whether the combination of media screen time with genetic background is a better predictor of CVD than either factor alone. The theoretical framework was the social ecological theory of disease distribution. The relationship between media screen time, genetic background, and CVD risk factor was determined using binary logistic regression. Results of this study indicated that the relationship between ethnicity, gender, and type/duration of exposure to media screen is important to predict the CVD risk factors C-reactive protein (CRP), triglycerides, and diastolic blood pressure. Interventions that limit exposure total screen time will reduce the risk of increased blood pressure among all races. However, culturally relevant intervention should be designed specifically for non-Hispanic Blacks, other Hispanics, and other race. These ethnicities have the highest propensity to increase in blood pressure, CRP, and triglycerides and also spend the largest amount of time in front of the media screen. Results from this study may help to promote policies and initiatives to limit screen time that are culturally relevant and more focused.
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