Development of a screening method for drought tolerance in cotton seedlings

The key to an efficient screening method is the ability to screen large amounts of plant material in the shortest time possible. Unfortunately, due to the complexity of drought tolerance, a quick and effective screen for this trait has yet to be established. The research reported herein was designed to evaluate a screening method for drought tolerance in cotton (Gossypium hirsutum L.) seedlings. Twenty-one converted race stocks (CRS) and two cultivars were evaluated for seedling drought tolerance on an individual plant basis. CRS are day-sensitive primitive lines derived from various wild race stocks that were converted to day neutrality for use in temperate region plant improvement programs (McCarty et al., 1993). Genotypes were evaluated October - November 2004 and February - March 2005 under greenhouse conditions at the Norman E. Borlaug Center for Southern Crop Improvement, College Station, TX. Seedlings were subjected to three sequential cycles of drought at 15 days after planting (DAP). Drought cycles consisted of withholding water until the moisture content of "indicator" cone-tainers, containing Deltapine 491 (DP 491), had an average volumetric water content of 0.07. Plants were then watered to field capacity and percent survival was recorded after 48 hours. Genotypes differed in their percent survival following three consecutive drought cycles. Drought cycles 2 and 3 did not contribute to the separation of genotypes. DP 491 was the most tolerant genotype evaluated. None of the CRS were more or less tolerant than Acala 1517-99. CRS M-9044-0165 was the most stable genotype across the two experiments

MEASURES OF PHYSICAL FUNCTION AS RISK FACTORS FOR DIABETES MELLITUS AND INSULIN RESISTANCE AMONG HIV-UNINFECTED AND HIV-INFECTED MEN

Physical activity is an accepted intervention for the prevention of diabetes mellitus (DM) and insulin resistance (IR) in the general population. Few studies in HIV-infected persons assessed the role of physical function or physical activity as a contributing factor to glucose disorders. The relationship between self-reported and performance-based measures of physical function in HIV-infected individuals has not been assessed. This dissertation examined associations between self-reported and performance-based measures of physical function, DM, and IR in HIV-uninfected and HIV-infected men.Data from 658 men from the Pitt Men¡¦s Study were analyzed to assess the contribution of self-reported physical function to prevalent DM and IR. Physical function score (AOR 1.5 per 25 unit decrease, p=0.02) was significantly associated with diabetes, but not IR, after adjustment for covariates. Data from 1790 men from the Multicenter AIDS Cohort Study (MACS) were used to assess physical function as a risk factor for incident DM and IR. Cumulative DM incidence was highest among HIV-uninfected and HIV-infected men with low physical function. Low physical function was a risk factor for incident DM in HIV-uninfected men using more stringent (HR 1.31; 95% CI 1.02-1.66) and less stringent (HR 1.29; 95% CI 1.11-1.50) diabetes definitions adjusting for BMI, family history of diabetes and race. Among HIV-infected men, physical function was a risk factor for incident DM using the less stringent diabetes definition. To assess the relationship between self-reported and performance-based measures of physical function, DM and IR, a cross-sectional study of 2079 men from the MACS was conducted. Self-reported physical function and performance-based measures correlated weakly. (HIV-uninfected: ƒâ=0.12-0.23, p<0.01; HIV-infected ƒâ=0.16-0.24, p<0.01). Self-reported physical function had a stronger association with DM and IR than performance-based measures in HIV-uninfected but not HIV-infected men.There are important public health implications of this dissertation. Low physical function is a risk factor for DM in two cohorts of HIV uninfected and HIV-infected men; therefore interventions to increase physical function may decrease DM risk while simultaneously reducing the risk of further disability and chronic sequelae among HIV-infected individuals already diagnosed with diabetes. This is essential given the national burden of HIV infection and DM

Evaluation of chlorophyll fluorescence as a tool for the identification of drought tolerance in upland cotton

A novel bioassay for the evaluation of plant water status was developed by Burke (2007). The research reported herein was designed to evaluate this new protocol as a tool for use in cotton breeding programs for the identification of drought tolerant genotypes. Twenty genotypes were selected to represent diverse germplasm pools for a two-year field evaluation. Replicated tests were performed in Lubbock, TX and College Station, TX in 2005, 2006, and 2007. Dryland and irrigated treatments were administered in a split plot arrangement of a randomized complete block design. Fluorescence measurements were taken at mid-bloom and late bloom growth stages of growth. Source leaf tissue was harvested at predawn and subjected to high temperature incubation with fluorescence measurements subsequently taken hourly for five hours. Drought stressed plants had not mobilized their carbohydrate reserves from their source leaves overnight and thus maintained cell viability and therefore higher chlorophyll fluorescence values throughout the incubation with the opposite being true for nonstressed plants. Fiber lint yield and fiber properties were measured at the conclusion of the 2005 season in College Station and the 2006 season in College Station and Lubbock for comparison with the fluorescence data. Five genotypes, ‘Acala 1517-99’, ‘Deltapine 491’ (PVP no. 200100159), ‘Tamcot CAMD-E’, ‘Tamcot 22’ and TAM 89E-51, an unreleased breeding line, were selected based on field evaluation results in a preliminary study in 2005 to be included in a diallel analysis to determine the heritability of fluorescence measurements. Genotype x treatment effects complicated the classification of genotypic responses to drought. Few and inconsistent correlations were found among fluorescence values and lint yield or fiber properties. The diallel analysis did not identify general combining ability or specific combining ability effects for chlorophyll fluorescence measurements. Thus this procedure provides little potential in selecting plants for drought tolerance when plants are grown under field culture. Selection among Tamcot 22 and TAM 89E-51 plants for high and low genotypes according to fluorescence values did not yield progeny different from unselected Tamcot 22 and TAM 89E-51

Development of a screening method for drought tolerance in cotton seedlings

The key to an efficient screening method is the ability to screen large amounts of plant material in the shortest time possible. Unfortunately, due to the complexity of drought tolerance, a quick and effective screen for this trait has yet to be established. The research reported herein was designed to evaluate a screening method for drought tolerance in cotton (Gossypium hirsutum L.) seedlings. Twenty-one converted race stocks (CRS) and two cultivars were evaluated for seedling drought tolerance on an individual plant basis. CRS are day-sensitive primitive lines derived from various wild race stocks that were converted to day neutrality for use in temperate region plant improvement programs (McCarty et al., 1993). Genotypes were evaluated October - November 2004 and February - March 2005 under greenhouse conditions at the Norman E. Borlaug Center for Southern Crop Improvement, College Station, TX. Seedlings were subjected to three sequential cycles of drought at 15 days after planting (DAP). Drought cycles consisted of withholding water until the moisture content of "indicator" cone-tainers, containing Deltapine 491 (DP 491), had an average volumetric water content of 0.07. Plants were then watered to field capacity and percent survival was recorded after 48 hours. Genotypes differed in their percent survival following three consecutive drought cycles. Drought cycles 2 and 3 did not contribute to the separation of genotypes. DP 491 was the most tolerant genotype evaluated. None of the CRS were more or less tolerant than Acala 1517-99. CRS M-9044-0165 was the most stable genotype across the two experiments

Senior Recital: Jon Klausman, trumpet

This recital is presented in partial fulfillment of requirements for the degree Bachelor of Music in Performance. Mr. Klausman studies trumpet with Douglas Lindsey and Michael Tiscione.https://digitalcommons.kennesaw.edu/musicprograms/1939/thumbnail.jp

Senior Recital: Travis Longenberger, tenor trombone

This recital is presented in partial fulfillment of requirements for the degree Bachelor of Music in Performance. Mr. Longenberger studies trombone with Thomas Gibson.https://digitalcommons.kennesaw.edu/musicprograms/2092/thumbnail.jp

Structural Characterisation of Printable Noble Metal/Poly(Vinyl-­Alcohol) Nanocomposites for Optical Applications

This work was conducted under the aegis of the Engineering and Physical Sciences Research Council (EPSRC) of the United Kingdom (EP/I004173/1). Amin Abdolvand is an EPSRC Career Acceleration Fellow at the University of Dundee.In order to enable exploitation of noble metal/poly(vinyl-alcohol) nanocomposites for device fabrication, solutions of poly(vinyl-alcohol) suitable for piezo-driven inkjet printing techniques are identified and discussed in terms of their material properties. The printable poly(vinyl-alcohol) medium is then exploited as a host material through the formation of silver or gold nanoparticles in order to create nanocomposites that exhibit a surface plasmon resonance behaviour associated with the small metallic inclusions. To mitigate some of the material redistribution effects associated with the drying of printed droplets containing finely divided materials, the metallic nanoparticles are formed after the printing and drying process is completed, by way of an in-situ reduction of an appropriate metal salt by the poly(vinyl-alcohol)-host matrix itself, which takes place at modest temperatures compatible with most substrate materials. An obvious application for such nanocomposites is in optical elements whereby the surface plasmon resonance associated with the metal is the functional aspect of devices such as sensors or active optical elements. High Resolution Transmission Electron Microscopy was used to examine the dimensions, distribution, morphology and crystal structure of the silver and gold nanoparticles in detail allowing discussion of their suitability for these applications and what further optimisation may be necessary to adequately control their formation.Publisher PDFPeer reviewe

Cathodic Corrosion: A Quick, Clean, and Versatile Method for the Synthesis of Metallic Nanoparticles**

A simple and effective method for the synthesis of nanoparticles is reported based on extreme cathodic polarization of a metal, formation of cation-stabilized metal anions, and their agglomeration (see picture). The improved catalytic activity of these nanoparticles in the oxidation of carbon monoxide as well as methanol is shown using platinum.<br/

Statins in unconventional secretion of insulin-degrading enzyme and degradation of the amyloid-β peptide.

Population-based studies demonstrated that statins might decrease the risk of developing Alzheimer's disease (AD). Statins inhibit the 3-hydroxy-3-methyl-glutaryl-coenzyme-A reductase and thereby de novo synthesis of cholesterol. Cell culture and animal studies indicated that cholesterol affects the proteolytic processing of the amyloid precursor protein and the generation of amyloid-β (Aβ). Recently, we have demonstrated that statins can also stimulate the degradation of Aβ. The statin-induced clearance of Aβ could be attributed to increased release of the insulin-degrading enzyme (IDE) via an exosome-related unconventional secretory pathway. Interestingly, this statin-induced secretion of exosome-associated IDE was independent of cellular cholesterol concentrations, but rather caused by impairment of isoprenoid biosynthesis and protein prenylation. We further identified a new hexapeptide sequence in the C-terminal region of IDE, named the SlyX motif that is critically involved in IDE secretion. Taken these findings together, the increased clearance of Aβ by stimulated secretion of IDE might contribute to the protective effects of statins against AD

A survey of diamagnetic probes for copper(2+) binding to the prion protein. H-1 NMR solution structure of the palladium(2+) bound single octarepeat

The prion protein (PrPC) is a copper binding cell surface glycoprotein which when misfolded causes transmissible spongiform encephalopathies. The cooperative binding of Cu2+ to an unstructured octarepeat sequence within PrPC causes profound folding of this region. The use of NMR to determine the solution structure of the octarepeat region of PrP with Cu2+ bound has been hampered by the paramagnetic nature of the Cu2+ ions. Using NMR we have investigated the binding of candidate diamagnetic replacement ions, to the octarepeat region of PrP. We show that Pd2+ forms diamagnetic complexes with the peptides HGGG, HGGGW and QPHGGGWGQ with 1 : 1 stoichiometry The H-1 NMR spectra indicate that these peptides are in slow-exchange between free and bound Pd2+ on the chemical-shift time-scale. We demonstrate that the Pd-peptide complex forms slowly with a time taken to reach half-maximal signal of 3 hours. Other candidate metal ions, Ni2+, Pt2+ and Au3+, were investigated but only the Pd2+ complexes gave resolvable H-1 NMR spectra. We have determined the solution structure of the QPHGGGWGQ-Pd 1 : 1 complex using 71 NOE distance restraints. A backbone RMSD of 0.30 angstrom was observed over residues 3 to 7 in the final ensemble. The co-ordinating ligands consist of the histidine imidazole side chain N epsilon, the amide N of the second and third glycines with possibly H2O as the fourth ligand. The co-ordination geometry differs markedly from that of the HGGGW-Cu crystal structure. This survey of potential replacement metal ions to Cu2+ provides insight into the metal specificity and co-ordination chemistry of the metal bound octarepeats