Weeds cause significant yield loss in sweetpotato. Post-emergent herbicides cause damage to sweetpotato plant, which necessitates development of herbicide tolerant sweetpotato. An optimal tissue culture system is a prerequisite for in vitro screening of herbicide tolerant sweetpotato. Three Louisiana cultivars, Beauregard, Orleans, and LA 07-146, were tested to develop an efficient callus induction and plant regeneration system. 2, 4-D @ 0.23 µM was ideal for Beauregard and Orleans callus induction and 0.45 µM 2, 4-D for callus induction in LA 07-146. Phytohormone-free media was found suitable for regeneration. Plants were regenerated from callus tissues that survived in vitro with 2 µM, 6 µM, 8 µM and 10 µM of halosulfuron methyl (active ingredient of herbicide Sandea®). The culture conditions identified through this study have applicability to wide use in somaclonal selection in sweetpotato. Adventitious root emergence from original cuttings of sweetpotato marks the initial phase of storage root development. A better understanding of the mechanism of adventitious rooting in sweetpotato will be of immense importance to strategize breeding efforts to maximizing its marketable yield. In the present study, role of ethylene in adventitious rooting was investigated by application of 3.8 ppm of 1-mcp to two sweetpotato cultivars, Beauregard and Evangeline, known to have contrasting adventitious rooting in response to 1-mcp. Sequencing of suppression subtractive hybridization libraries from both cultivars indicated that genes involved in the cell wall and sugar biosynthesis pathway were differentially expressed by exogenous application of 1-mcp. Two component response regulator, fructose bisphosphate aldolase and arabinogalactan, were present in both cultivars. However, their expression pattern varied at different time points between Beauregard and Evangeline. Genes coding for ascorbate oxidase and oxysterol-binding protein were upregulated in Beauregard whereas two-component response regulator was upregulated in both Beauregard and Evangeline. Except for a slight upregulation of fructose-bisphosphate aldolase in Beauregard and arabinogalactan in Evangeline at 12 h time point, both genes showed downregulation in both cultivars at all other time points. Most of the differentially expressed genes were shown to be involved in ethylene signaling. This study confirmed previous results that ethylene is involved in adventitious rooting in sweetpotato.

The soil organic carbon (SOC) pool is an important component of the global carbon budget. Agricultural systems in particular have been identified as an area in which SOC may be increased appreciably when managed for carbon sequestration. In the southern climate region of the United States, potential rates of carbon sequestration in soils are largely unquantified. The aim of this study was to quantify SOC and its spatial variability under two long-term residue management systems, burn and no-burn, for sugarcane (Saccharum Spp. Hyb.). Soil cores to a depth of 1 m were collected using a Giddings probe. Thirty soil cores per treatment were collected along a transect with 1.8-m spacing. Parameters measured were SOC, soil nitrogen, bulk density, gravimetric water content, CEC, and pH. Comparisons between treatments were conducted using paired t-tests. Geostatistical analyses were used to investigate 2-D vertical and lateral spatial trends. In a subsequent sampling, soil cores were collected from depths up to 2.7 m, and SOC, soil nitrogen, and gravimetric water content were measured. Differences in SOC between the two treatments were significant (t = 2.35, p = 0.019) and indicated that the no-burn treatment contained more SOC than the burn treatment. Variogram models indicated that the no-burn treatment (range = 10.19 m) had higher spatial variability than the burn treatment (range = 18.95 m), and kriging illustrated that the burn treatment had a SOC content that was more evenly distributed with depth. Some 70 % of SOC was in the 20-100 cm soil depth, and the greatest differences between the treatments occurred at depths below 60 cm. Estimated carbon sequestration was 0.56 Mg/ha/yr. A major finding from this study is that soil carbon sequestration in the burn and no-burn managements was consistent with other studies in the region; however, significant quantities of SOC may be present at depths below the typical 20-cm sampling depth, and ignoring deeply distributed carbon may result in the underestimation of carbon sequestration.

The 2013 Report Card for the Nations Infrastructure, published by the American Society of Civil Engineers, estimates that more than 10% of the over 607,000 bridges in the United States are structurally deficient. Engendering a further sense of urgency for addressing bridge integrity is the impact of projected climate change and associated weather events. The most recent assessment report published by the IPCC concludes that the frequency of heavy precipitation events is increasing along with a concomitant increase in severe flooding. Several software applications are available that perform flood modeling and, in some instances, damage analysis resulting from the flood. Of the software identified, FEMAs HAZUS-MH, or Hazus, offers a balance between affordability, simplicity and accuracy. Hazus does demonstrate limitations when modeling floods in sub-county areas but at the county-level scale, predicted floods approximate observed floods. Using the US DOTs HEC-18 guide for bridge scour, a methodology was developed for estimating the monetary damage of bridge scour from a future flood event using flood parameters supplied by Hazus and other readily available resources. Results of the methodology indicated predicted and observed damage values did not exhibit a statistically significant difference (p=0.22, tá=0.05). Additionally, a Pearsons correlation coefficient of approximately 0.94 was observed. A demonstration of the methodology application was performed in which several bridges in Little Rock, Arkansas were assessed for adaptation planning prioritization.

No description available.

The effect of cultivar, curing, storage, tissue type, and cooking method on the ascorbic acid (AA), thiamin, riboflavin, and vitamin B6 content of sweetpotato was determined. A simplified and sensitive reverse-phase high performance liquid chromatography (HPLC) methodology was developed for the simultaneous determination of thiamin and riboflavin in sweetpotato. Curing of sweetpotatoes did not significantly change the content of AA, thiamin, and vitamin B6, but resulted in a decrease in riboflavin content. Thiamin and riboflavin contents were mostly stable after curing. However, compared to at harvest, storage for 6 months resulted in a decrease in AA content in cultivars 07-146, Covington, and Beauregard; and a gradual increase in vitamin B6 content in 07-146, Orleans, and Covington. Although 07-146 contained higher vitamin B6 content, no cultivar was superior or inferior for all the vitamins throughout 6 months of storage. Exposure of sweetpotatoes to chilling injury temperatures of 1 °C and 6 °C for 2 or 4 weeks did not result in consistent changes in AA, thiamin, and riboflavin. However, transfer of the low temperature-stored roots to 14 °C for an additional 7 days generally resulted in AA decreases and stable thiamin and riboflavin contents. Water-soluble vitamin concentration differed between tissue types. Leaf tissue contained no detectable amounts of thiamin, but contained the highest concentrations of AA, riboflavin, and vitamin B6. Cooking methods, including microwaving, boiling, and baking resulted in lower AA compared with raw tissue, but in little differences in thiamin, riboflavin, and vitamin B6. The overall results of this research suggest that while AA is detrimentally affected during commonly used sweetpotato cooking methods, and during typical storage conditions, thiamin, riboflavin, and vitamin B6 contents remain mostly stable. Additionally, they confirm previous reports indicating vegetative tissues can be a good source of AA and multiple B vitamins in human diets.

Thesis (MA) -- AUT University, 2007. / Includes bibliographical references. Also held in print (xiii, 109 leaves : col. ill. ; 30 cm.) in City Campus Theses Collection (T 333.720993 NEW)

Thesis (M. Sc.)--University of Hong Kong, 2000. / Includes bibliographical references (leaves 73-78).

Thesis (Ph.D.)--Portland State University, 2008. / Includes bibliographical references.

Thesis (M.Hous.Man.)--University of Hong Kong, 2009. / Includes bibliographical references (p. 131-136).

Stakeholders increasingly have a heightened expectation of organisational commitment to good environmental and societal practice. Proponents of the link between environmental and financial performance have argued that pollution reduction provides future cost savings by increasing efficiency, reducing compliance costs, and minimising future liabilities. Environmental management systems such as BS EN ISO 14001:1996 or the Eco-Management and Audit Scheme (EMAS) do not require organisations to comment on overall environmental performance. BS EN ISO 14001: 1996 simply advocates that the organisation should have viewed each particular function of the business process and applied a self- formulated quantitative/qualitative analysis to the function in question, providing no incentive to add a level of independently verifiable transparency to the analysis process. This thesis investigates whether it is possible to develop an environmental management system that is capable of delivering a quantitative social/economic statement based on the pollutant aspects/effects of the organisation. A model for quantitative pollution management (QPM) is developed, and a scoring mechanism is defined which enables an indicator of pollution performance to be derived. This indicator reviews the organisation as a whole system, as well as commenting on its constituent parts. The indicator is based upon evaluation of five areas, those of management /leadership, inputs, controls, activities, and outputs. The model is tested in industry by an audit of a manufacturing organisation in South Wales, and a numeric QPM indicator is derived. The numeric QPM indicator is subsequently considered by means of a qualitative interpretation of the quantitative indicator score. The qualitative interpretation is then considered against the impression of the organisation gained by the author during the conduct of the audit. Potential future work in relation to QPM is considered, and the possible application of the concepts of fuzzy logic to QPM is given.