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Development and Utilization of Molecular Markers to Study Genetic Diversity of Smooth Cordgrass and Cold Tolerance in SugarcaneBernaola Alvarado, Lina 27 April 2012 (has links)
Smooth cordgrass (Spartina alterniflora Loisel) and sugarcane (Saccharum spp. hybrids) are both grasses that belong to the family Poaceae and have significant impact on Louisiana environment and economy. Coastal Louisiana accounts to ~80% of the national wetland loss through natural and human interventions; (re)vegetation is considered an important component of coastal restoration efforts. Smooth cordgrass, a warm season marsh grass, is used as an ecosystem engineer to stabilize and restore Louisiana coastal marshes. In this study, genetic diversity was determined among 13 elite smooth cordgrass accessions of Louisiana through 276 polymorphic markers generated by 23 SSR and 32 RAPD primers. AMOVA results showed that sufficient variation existed among smooth cordgrass accessions for further exploitation in breeding program. A few genetic markers unique to specific smooth cordgrass accession(s) were also developed. Sugarcane, the number one row crop in Louisiana, is sensitive to cold; so cold tolerance is desirable to expand its cultivation in more northern environments. Cold tolerance alleles of Saccharum spontaneum can be exploited to develop sugarcane clones tolerant to low temperatures. To this end, forty differentially expressed genes (DEGs; 29 up-regulated and 11 down-regulated) were identified in a cold-tolerant clone Ho02-144 and a cold-sensitive clone L79-1002 under cold stress, using annealing control primer system. Reverse-transcription PCR (RT-PCR) analysis of the cold-responsive DEGs revealed distinctive expression profiles in the tolerant and sensitive clone. Mining of the cold-responsive DEGs yielded 12 sequences with simple sequence repeats (SSRs), which were used to design eSSR primers. Genotyping of 48 Louisiana sugarcane clones and 16 ancestral parents with these eSSRs generated 170 polymorphic markers that could classify cultivated sugarcane clones from their ancestral S. spontaneum clones at 0.23 similarity coefficient. The cold responsive genes will be useful for breeding cold tolerant sugarcane either through genetic engineering or selection through the use of gene-based markers.
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Application of Genetic and Statistical Tools for Improvement of Louisiana RiceSilva Garcia, James 03 July 2012 (has links)
Breeding for grain quality traits and resistance to sheath blight (SB), a disease caused by Rhizoctonia solani Kuhn, are important objectives for the rice (Oryza sativa L.) industry. Grain quality traits and SB resistance play an important role in the economic prosperity of commercial rice markets. The objectives of our research were to: (1) Explore performance and stability for SB resistance among doubled-haploid (DH) lines of the SB2 mapping population using GGE biplots (2) Exploit whole genome sequences of 13 inbred lines to identify non-synonymous SNPs (nsSNPs) and candidate genes for SB resistance.
Genotype-by-environment interaction for SB analysis was performed using heritability-adjusted GGE (HA-GGE) biplot. DH lines were evaluated for two years in Louisiana and Arkansas; a single mega-environment was identified consisting of the four year-location combinations. HA-GGE biplot analyses identified 11 high and stable DH lines; five susceptible DH lines were also identified with greater stability than the susceptible parent used to develop the SB2 population. Material identified in this study represents a potential source of SB resistance for cultivar development.
Two filtering strategies were developed to identify nsSNPs between two groups of known resistant and susceptible lines. More than 200 genes with selected nsSNPs were assigned to 42 categories based on family/gene ontology. Individual alleles of 24 nsSNPs were evaluated by PCR whose presence/absence corresponded to known resistant/susceptible phenotypes of nine additional lines. Resistant alleles were detected in two accessions of O. nivara that suggests sources for resistance occur in additional Oryza sp. Results from this study provide a foundation for future marker-assisted breeding of rice for SB resistance.
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Visible Near-infrared Diffuse Reflectance Spectroscopy and Portable X-ray Fluorescence Spectroscopy for Rapid Compost AnalysisMcWhirt, Amanda Lynne 28 June 2012 (has links)
Quantitative and qualitative evaluation of compost is necessary in order to provide consumers with basic knowledge about the products composition, and to protect public health and the environment by preventing the spread of contaminated material. Current methods for analysis of basic compost properties give accurate results but are time consuming and require numerous laboratory procedures. This study evaluated the use of visible near-infrared diffuse reflectance spectroscopy (VisNIR DRS) for organic matter (OM) determination and field portable X-ray fluorescence (PXRF) spectroscopy for determination of elemental composition of composted materials. These technologies were evaluated as alternatives to standard laboratory methods for their use in rapid in situ analysis. Thirty-six compost samples from a wide range of feedstocks were gathered and tested with VisNIR DRS and PXRF. For VisNIR DRS, the influence of sample moisture on scanning results was evaluated and the use of raw reflectance, first-derivatives, and second-derivatives of the reflectance spectra were compared. Partial least squares regression (PLS) and principal component regression (PCR) were used to build regression models of VisNIR DRS scans and lab measured OM. For PXRF, the influences of sample moisture, particle size, inter-elemental interactions, and OM on PXRF scanning results were investigated. Results from the VisNIR DRS study produced a promising r2 value of 0.82 and residual prediction deviation (RPD) value of 1.72 for the ovendried first-derivative PLS model. Results indicate that VisNIR DRS shows great promise as a technique for analysis of OM content of dried compost samples, however further investigation with a larger sample set is necessary before VisNIR DRS can replace laboratory methods. Results of PXRF for elemental analysis were most promising for dried samples and for determining the elements Ca, Cr, Cu, Fe, K, Mn, P, and Zn. Arsenic detection was found to be greatly limited due to the influence of elevated Pb concentrations in the samples. Additionally, sample moisture, particle size, and
OM were found to have varying influences on PXRF scan results for different elements. Compost elemental screening and definitive quantification of certain elements via PXRF is recommended by this study.
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Sugarcane Growth, Sucrose Content, and Yield Response to the Ripeners Glyphosate and Trinexapac-ethylOrgeron, Albert Joseph 11 November 2012 (has links)
Under Louisiana climatic conditions, production of sugarcane (Saccharum spp.) is limited to a maximum growth period of nine months. To increase sucrose concentration in the crop, ripener is applied prior to harvest. The chemical ripeners, glyphosate and trinexapac-ethyl were applied to the sugarcane cultivars HoCP 96-540, L 99-226, L 99-233, HoCP 00-950, and L 01-283 eight weeks prior to harvest. When glyphosate was applied at 210 g ae/ha, TRS for the cultivars was increased 10 to 28% compared with the nontreated. Increases in TRS with glyphosate were greatest for HoCP 96-540 and L 99-226 and least for HoCP 00-950 and L 01-283. Trinexapac-ethyl at 350 g ai/ha increased TRS for the cultivars 7 to 10% and increases were greatest for L 99-233 and least for HoCP 00-950. Sugarcane yield averaged across cultivars was reduced 9% with glyphosate and 7% for trinexapac-ethyl at 350 g/ha. An increase in sugar yield per hectare, a function of TRS and sugarcane yield, was observed only when glyphosate was applied to HoCP 96-540 (16% increase) and when trinexapac-ethyl at 300 g ai/ha was applied to L 01-283 (13% increase). In a second study where eight cultivars were harvested six weeks after glyphosate application, TRS for HoCP 96-540 was increased an average of 10% compared with the nontreated and sugarcane yield was decreased 17%; sugar yield was not affected.
In another study, sugarcane yield, TRS, and sugar yield were not affected by nitrogen rates of 67, 112, and 157 kg/ha. Six weeks after application of glyphosate at 210 g/ha TRS averaged across N rates was 11% greater than the nontreated and 9% greater than when trinexapac-ethyl was applied at 350 g/ha. TRS following trinexapac-ethyl was equivalent to the nontreated. Sugarcane yield and sugar yield were not affected by ripener application. In a separate study TRS and sugar yield were not affected when glyphosate or trinexapac-ethyl was applied in 75 and 150 L/ha spray volume or when none or 0.25% v/v surfactant was added to the spray solution. Averaged across spray volume and surfactant treatments, TRS was as much as 8% greater for glyphosate compared with trinexapac-ethyl.
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Understanding Phosphorus Dynamics of Two Alluvial Soils Grown with Corn at Different Phosphorus RatesDalen, Marilyn Sebial 19 November 2012 (has links)
There is little information documented on the influence of soil properties on P availability of Louisiana alluvial soils thus this pot experiment was conducted in 2011 to: 1) evaluate the effect of P fertilizer rate on growth and development of corn grown on Perry clay and Commerce sl soils, 2) relate soil test P values using Mehlich-3 and Bray-2 procedures with yield, total biomass, and P uptake of corn, and 3) identify the soil properties that influence P partitioning into functional fractions of two alluvial soils. Different P fertilizer rates (0, 34, 67, 101 and 134 kg P2O5 ha-1) were applied, replicated four times and arranged in a randomized complete block design. After 30 days, corn was planted and grown until maturity. Mehlich-3 extractable-P, Bray-2, total-P and Pi fractions (labile-P, Al-P, Fe-P, reductant-P, and Ca-P) of soil samples collected at 30 DAP and at harvest were quantified.
The Bray-2 P values were about six times higher than Mehlich-3 P values for Commerce sl while for Perry clay, the amounts of P extracted by these two procedures were very similar (1:1 ratio). Both Bray-2 and Mehlich-3 extractable-P of both soils increased with increasing P rate. Commerce sl and Perry clay soils tested low to medium for Mehlich-3 extractable-P but responded differently with the application of P fertilizer. Grain yield of corn grown on Perry clay significantly responded to P rate but not in Commerce sl which was testing very high for Bray-2 extractable-P. The applied P fertilizer was transformed into Ca-P for Commerce sl while Perry cl transformed into Fe- and reductant-P. Overall, the labile- and Al-P at 30 DAP increased with increasing P rate. With time across P rates, both soils showed build-up of less readily-available reductant-P. For total-P, residual-P and total-Pi components, Commerce sl and Perry clay differed significantly (P<0.05) at both 30 DAP and harvest; while total-P and residual-P of both soils were not affected. Refinement of soil test P prediction should be pursued such that P fertilizer recommendations will not be based solely on P soil test.
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Effects of Seeding Rates of Perennial Ryegrass (Lolium perenne L.) on Sediment Loading and Nutrient Transport via Surface RunoffAnderson, Jason Robert 28 November 2012 (has links)
Sediment loading and nutrient losses from construction sites through surface runoff can have detrimental effects on nearby water bodies. Often cool-season grasses such as perennial ryegrass (Lolium perenne L.) are established for temporary coverage until environmental conditions are suitable for warm-season grass establishment. The purpose of this research was to 1) determine if higher seeding rates accelerate establishment thus reducing sediment loading and 2) determine if watering-in fertilizer applications reduces nutrient losses through surface runoff. In the first experiment trays were seeded at 0, 195, 390, or 585 kg ha-1 with 30-min rainfall simulations performed at 16.3 L per minute at 14, 28 and 42 days after seeding (DAS). Increasing seeding rates reduced total sediment loading 48% to 67% and 86% of sediment eroded from bare soil over the 42-day establishment period. Sediment losses were highest during the initial rainfall simulation at 88, 93, 83, and 62% of total sediment lost from 195, 390, or 585 kg ha-1 and bare soil controls, respectively. In the second experiment, established perennial ryegrass was fertilized at 50 kg N ha-1 with grass swards not irrigated or irrigated at 1.25 cm 48 hours prior to rainfall simulation. Thirty-minute rainfall simulations were performed 2 and 7 days after fertilization (DAF). Non-irrigated fertilizer treatments resulted in the highest TKN losses of 12.3 kg N ha-1, moderate dissolved N losses at 3.1 mg N ha-1, and highest TP losses of 2.4 P ha-1 2 DAF compared to 7.0 kg TKN ha-1, 5.2 kg DN ha-1, and 2.0 kg TP ha-1 for irrigated fertilizer treatments. At 7 DAF, iIrrigated fertilizer treatments resulted in higher dissolved N losses of 3.1 kg N ha-1 compared to 0.1 kg N ha-1 for non-irrigated treatments but similar TKN and TP losses of 0.8 kg N ha-1 and 0.4 kg P ha-1 compared to 0.9 kg N ha-1 and 0.2 kg P ha-1 lost from non-irrigated treatments. The two experiments showed increasing perennial ryegrass seeding rates during establishment can significantly reduce sediment losses; while irrigating post N fertilization of established swards may not reduce N losses during surface runoff.
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Transport and Adsorption-Desorption of Heavy Metals in Different SoilsElbana, Tamer A. 26 April 2013 (has links)
Understanding the reactivity and mobility of heavy metals in soils is indispensable for assessing their potential risk to the environment. In this study, column transport and batch kinetic experiments were performed to assess the sorption-desorption and mobility of Cd, Cu, Pb, and Sn in alkaline and acidic soils. Furthermore, sequential extractions were accomplished to examine their behavior in soils. Also, the competitive reactivity of Sn and Pb in two acidic soils was quantified. Additionally, the effect of introducing Cd and Cu after a Pb pulse in calcareous soil was presented. Modeling of these heavy metals retention and transport was carried out using different models; multireaction and transport model, CXTFIT model, kinetic ion exchange formulation, and second-order two-site model. The results revealed that: 1) the studied heavy metals exhibited strong nonlinear and kinetic retention behavior; 2) Cd was nearly immobile in alkaline soil with 2.8% CaCO3, whereas 20 and 30% of the applied Cd was mobile in the acidic soil and the subsurface layer of the alkaline soil with 1.2% CaCO3, respectively; 3) for a short Cu pulse, the recoveries were <1 and 11% for alkaline and acidic soils, respectively, whereas, for the long Cu pulse, the recoveries ranged from 27 to 85% for the studied soils; 4) tin was highly sorbed in acidic soils where more than 99% of applied Sn was retained in the acidic soils columns; 5) the presence of Sn in solution reduced Pb retention in soils since the Pb recovery in the effluent solution ranged from 37.4 to 96.4%; and 6) the multireaction approach was capable of describing heavy metals retention and transport in soil columns.
Moreover, a field study of the spatial distributions and the accumulation of Pb, Cd, Cu, and Ni among soil depth as consequence of irrigation with domestic wastewater were studied. The results of this research showed that Pb, Cu, and Ni had high affinity for retention in the surface soil layer whereas Cd results showed homogeneous distribution within soil depth. The impact of time scale effect on accumulation and spatial distribution of heavy metals indicated the urgent need for remediation and rational management.
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Soil Organic Carbon Determination for Louisiana Soils via Portable X-Ray Fluorescence SpectroscopyNuss, Sara Kathryn 12 September 2013 (has links)
As scientists work to investigate the mechanisms underlying the depletion of carbon from terrestrial ecosystems, there has been an urgent call for the development of test methods that offer reduced analysis times for soil organic carbon (SOC) determinations. Traditional laboratory techniques can be time-consuming and costly, making high-volume sample analyses problematic. Portable x-ray fluorescence spectroscopy (PXRF) provides quantitative, multi-elemental data for soil samples in as little as 60 seconds; and, unlike other spectroscopic methods, differences in elemental concentrations between field-moist and oven-dry samples are considered to be negligible when soil moisture contents are less than 20%, by weight. This study aims to evaluate the performance of various SOC prediction models, constructed from PXRF elemental data from 300 soil samples collected from alluvium and loess parent materials found in Louisiana, USA. Elemental data, in addition to pH and depth measurements, were used in the construction of prediction models using multiple linear regression (MLR) analysis and principal components analysis (PCA) statistical techniques. Previous research indicates that the use of a stability index may enhance SOC prediction modeling capabilities. Therefore, models utilized relative elemental abundances on the basis on Zr and Ti concentrations, and performances were compared to those resulting from models developed from Raw PXRF data. Results show that models constructed using field-moist PXRF elemental data provide excellent SOC prediction capabilities (R > 0.90) for both alluvium and loess datasets. Optimal performances resulted from the use of Ti as a stability index for field-moist datasets, producing accurate SOC predictions for both wet and dry validation sub-datasets. Findings indicate that PXRF elemental analysis, conducted under field conditions, provide for accurate SOC content determinations via MLR modeling of Louisiana alluvium and loess soil types examined in this study.
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INTEGRATION OF TRANSPORTATION AND EMERGENCY SERVICES: IDENTIFYING CRITICAL INTERFACES, OBSTACLES, AND OPPORTUNITIESShepherd, Kristen E. 25 April 2005 (has links)
INTEGRATION OF TRANSPORTATION AND EMERGENCY SERVICES:
IDENTIFYING CRITICAL INTERFACES, OBSTACLES,
AND OPPORTUNITIES
KRISTEN E. SHEPHERD
Dissertation under the direction of Professor Mark D. Abkowitz
Transportation and emergency services professionals interact in many situations, ranging from routine traffic accidents to large-scale events. Coordination between these groups is essential for effective and efficient response to various types of incidents. The term emergency transportation operations (ETO) represents all actions taken in regards to any incident occurring on the transportation infrastructure or requiring use of the transportation infrastructure, in order to protect health and safety.
The purpose of this research was three-fold: (1) determine if a need for improvement in ETO exists, the importance of interagency coordination in realizing such improvement, and the associated benefits and challenges of enhancing coordination; (2) determine the impact of organizational factors on coordination and to identify the institutional, operational, technological, and financial factors that impact ETO coordination; and (3) identify short term initiatives that could improve coordination, as well as explore the potential for change agents based on organizational design theory that would result in long term ETO improvement.
The findings from this research support the hypothesis that improvements in ETO are needed, and better coordination between transportation and emergency services is necessary. This research also concluded that institutional, operational, technological, and financial changes are necessary to improve ETO.
In the short-term, the most important and feasible initiatives to improve coordination are (1) including more transportation topics in training for emergency response personnel and vice versa, perhaps through new interagency training programs; (2) increasing participation in multi-agency operations planning for all types of hazards; and (3) improving interoperability of communication and other information technologies.
Greater coordination between these groups will only occur if organizational changes are made that induce ETO organizations to work together, sharing a common vision and objectives for success. Potential organizational design changes to improve coordination include implementing the functional design with horizontal linkages organizational structure, including such devices as shared information systems, task forces, full-time integrators, and teams. Furthermore, the Keiretsu model for multi-organizational relationships may offer added ETO coordination.
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Creation of a System for Assessing and Communicating the Risks Associated with Terrestrial Chemical SpillsBryant, Derek Lloyd 18 April 2006 (has links)
Adequately preparing for and responding to potential terrestrial (land-based) chemical spills are critical to the protection of human health and ecology. In this research, an environmental risk management system is developed to support analysis and facilitate decision-making for terrestrial chemical spill planning and response. This system is designed to serve a variety of stakeholders, including managers and policy-makers, who would benefit from generating screening level environmental risk assessments without requiring a technical background or collection of detailed environmental and chemical data. Areas of potential application include transportation routing, industrial zoning, environmental regulatory compliance and enforcement, spill response, and security planning.
The system leverages geographic information systems (GIS) technology to assess and delineate the immediate threat to human and environmental receptors from terrestrial chemical spills. It characterizes a spilled chemicals ability to immediately impact human health, groundwater, surface water, and soil resources, and incorporates these four receptors into an overall measure of terrestrial chemical risk. The methodology driving this characterization is a risk index model, which is supported by a comprehensive database containing information on chemical properties and environmental resources. This model differs from previous environmental risk indices in that it: 1) accounts for attributes of the local environment and contaminant in question, 2) requires almost no data input or scientific knowledge from the user, 3) creates an easy-to-understand visual output that supports the decision process, and 4) has the potential for transferability to sites throughout the United States.
In establishing proof of concept, the system is applied to a case study of a representative area in the United States. The potential terrestrial spill of several different chemicals is considered across all areas of Geauga County in the State of Ohio. Utilizing the system, risk assessment results are generated and visually displayed. The implications of these results are discussed in terms of how they impact decisions involving transportation routing, industrial zoning, environmental regulatory compliance and enforcement, spill response, and security planning.
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