Não Consta Resumo na Publicação / Abstracts Not Available

Honey bee population decline has been attributed to a variety of causes including infestation of hives with Varroa destructor mites. Fluvalinate has been extensively used in the United States to combat these mites for nearly 30 years, despite its high toxicity to honey bees. The objectives of the current research project were to investigate the extent of fluvalinate contamination in commercially available wax and to define exposure pathways from the contaminated wax and fluvalinate-impregnated strips to larval and adult honey bees. All of the commercial wax tested in the current study contained elevated fluvalinate concentrations, ranging from 170 to 1040 ng/g wet weight, indicating a need for regulation of the sources of wax being rendered for resale. Based on the negative logarithm of the partition coefficient between wax and pollen (-0.54) and the fact that all of the tested wax samples contained elevated concentrations of fluvalinate, it is evident that fluvalinate has the potential to actively transfer from the contaminated wax into bee hive matrices. This point was confirmed by adding fluvalinate-dosed wax, fluvalinate-impregnated strips, or a combination of the two to 10-frame hives. Larvae and adult bees from those hives were checked for fluvalinate exposure using gas chromatography-mass spectrometry analysis. Larvae had detectable concentrations of fluvalinate in all three treatments. Bioaccumulation in adult bees was significantly affected by the interaction between treatment type and application time. In other words, residues were comparable from hives that only had fluvalinate-dosed wax to those that were actively being treated with impregnated strips, strongly suggesting that transfer of fluvalinate from wax into adult bees was an important exposure route. In conclusion, exposure of fluvalinate from contaminated wax and treatment strips to larvae and adult honey bees is an important factor that needs to be considered when applying miticides and evaluating risk in honey bee hives.

No description available.

We wanted to develop rapid and cost-effective drought tolerance screening methods for mass amounts of germplasm. In 2009 and 2010, we evaluated sixty-two maize inbred lines and their hybrid testcross progeny using seedling stress response and epicuticular wax accumulation as predictors of drought tolerance. The seedling screening method measured germination, survival and recovery percentages after a series of drought cycles in a greenhouse environment. Eight inbred lines had significantly (P < 0.05) lower germination than the mean estimate, but hybrid testcrosses were not significantly different. The second-to-last day of survival cycle and the second day of recovery cycle best explained genotypic differences for inbred lines and hybrid testcrosses respectively. One inbred line performed well as both an inbred line and hybrid testcross, but poor correlation over the sample set (R2 = 0.0097) was observed. Flag leaves taken at flowering from plants under full and limited irrigation regimes were sampled for epicuticular wax. Extracted wax weight for genotypes was compared as a percentage of leaf weight (percent wxlfwt) and leaf area (percent wxwta). Eleven genotypes had above average percent wxlfwt as both inbred lines and hybrid testcrosses. Thirteen genotypes had above average percent wxwta as either inbred lines or hybrid testcrosses. Irrigation treatment was not significant (P > 0.05). Heritability of percent wxlfwt was 0.17 (inbred lines) and 0.58 (hybrid testcrosses). Heritability of percent wxwta was 0.41 (inbred lines) and 0.59 (hybrid testcrosses). Correlations (R2) for percent wxlfwt and percent wxwta were 0.19 and 0.03, respectively. Heritability of grams of grain per ear and total grain yield was highest in hybrid testcrosses, with no correlation between inbreds and hybrids. The developed seedling screening method easily allowed visible drought tolerance observations in inbred lines and hybrid testcrosses but does not seem heritable in our germplasm. Epicuticular wax weight is not an ideal primary trait to evaluate for drought tolerance, but may be a good candidate to observe as a secondary trait in relation to grain yield production in hybrids. Results from this research best supports breeder selection of hybrid germplasm using seedling drought tolerance in conjunction with epicuticular wax.

In wheat, cooler canopies have been associated with yield under high temperature stress. The objectives of this study were, i) to understand the role of leaf cuticular waxes as physiological adaptive mechanisms during reproductive stage high temperature stress ii) define quantitative trait loci (QTL) regulating leaf cuticular waxes and determine its link with the QTL for reproductive stage heat tolerance iii) define stable QTL associated with leaf cuticular waxes and yield stability across environments. For the first objective, thirteen wheat cultivars were subjected to a 2-day heat treatment at 38 degrees C at 10 days after pollination (DAP). Leaf cuticular waxes, canopy temperature depression and stomatal conductance were estimated during high temperature stress. At maturity the percent reduction in yield components in each cultivar was calculated. The wheat cultivars 'Kauz' and 'Halberd' had significantly high leaf cuticular wax content of 2.91mg/dm^-2 and 2.36mg/dm^-2 respectively and cooler canopies. Leaf cuticular waxes were significantly correlated with leaf temperature depression and reduction in yield components. A set of 121 recombinant inbred lines (RIL) population derived from the cross of heat tolerant wheat cultivar 'Halberd' and heat susceptible wheat cultivar 'Karl 92' was utilized for QTL mapping. The RIL population received a 2-day short-term high temperature stress at 38°C at 10DAP in 2008 and a long-term high temperature stress at 38 degrees C from 10DAP until maturity in 2009 in the greenhouse. The RIL population was also planted in College Station, Texas in 2009 and 2010 and in Uvalde, Texas in 2010. Leaf cuticular wax was estimated at 10DAP and leaf/spike temperatures were recorded during grain filling. Yield components were estimated after harvest. Heat susceptibility indexes for main spike yield components were estimated in the greenhouse. Overall ten significant QTL were identified for leaf cuticular waxes each explaining 8-19 percent of the variation respectively. Stable QTL for leaf cuticular waxes were located on chromosome 5A and 1B and co-localized with QTL for leaf/spike temperature depression and HSI for kernel weight and single kernel weight of main spike. Another QTL on chromosome 1B contributed by Karl92 was found in the greenhouse and field environments and co-localized with a previously identified QTL on 1B for spike non-glaucousness. The results suggest that leaf cuticular waxes may reduce leaf temperatures and improve adaptation during high temperature stress.

The presence of a blockage in a pipeline will alter the fluid dynamics of a flowing system in terms of the heat, mass and velocity characteristics. The analysis of the fluid dynamics is based on balances taken on the overall system to qualitatively and quantitatively assess the effects of the blockage. Pioneer work in the area of mass and momentum effects of blockages led to the development of blockage type curves useful in characterizing blockages from limited information. This work is an extension of previous work and is based on the application of a simplistic energy balance approach to characterize blockages in pipelines. The resulting heat models for the case of both a partially and fully-blocked flowline correctly predict the effect of wax deposition. Dimensionless temperature-based blockage maps developed here can be used in modeling unique cases where only two of the three necessary conditions are given. The heat model matches results from commercial software within a limited range of restricted flow conditions.

Apolipophorin-III (apoLp-III) is known to influence the haemocyte-mediated induction of antimicrobial peptides in Galleria mellonella and yeast phagocytosis, bind to Gram-negative and Gram positive bacteria and limit the activation of the haemocytes and the prophenoloxidase system by bacterial surface antigens. The effects of apoLp-III on haemocyte adhesion to glass slides and to bacteria were herein examined. ApoLp-III bound to haemocytes limiting the adhesion of both granular cells and plasmatocytes to glass and the contact of the plasmatocytes with Bacillus subtilis. The percentage of granular cells with bacteria was increased by the protein. However, the total number of bacteria adhering to haemocytes in vitro declined in the presence of apoLp-III. Bacterial removal from the haemolymph in vivo by the haemocytes was slowed by the protein. / The adhesion of both the granular cells and plasmatocytes to slides was decreased by inhibiting protein tyrosine kinase and increased by inhibiting protein kinase A (PKA) and protein kinase C (PKC) activity. The latter was confirmed with haemocytes inhibited by the general PKC inhibitor H-7 using phorbol-3-myfstate (PMA) which, by activating PKC, diminished the adhesion of both haemocyte types. Limiting the formation of PKC activation by diacylglycerides which is produced by phosholipase C (PLC), using PLC inhibitor also increased haemocyte attachment. Although binding of B. subtilis to haemocytes decreased PKC activity, the effect of apoLp-III on PKC was inconclusive.

La caracterització funcional de dos gens en la peridermis, la &#969; hidroxilasa d'àcids grassos CYP86A33 -candidata per la funcionalització del carboni &#969;-terminal dels monòmers alifàtics de la suberina- i la ketoacyl-CoA sintasa StKCS6 -candidata per elongar àcids grassos o derivats llargs de suberina i ceres- es realitza per silenciament per RNA d'interferència en patata. La deficiència de CYP86A33 comporta una gran reducció dels monòmers principals de la suberina, l'àcid gras &#969;-hidroxilat i l'&#945;,&#969;-diàcid C18:1, juntament amb una reducció total de la quantitat de suberina del 60%. Aquesta deficiència altera l'estructura lamel·lar típica de la suberina, així com també la funció barrera de la peridermis. La deficiència en StKCS6 comporta que els monòmers de la suberina de 28 carbonis o més llargs es redueixin i que els de 26 carbonis o més curts s'incrementin. Aquesta deficiència suggereix que la llargada dels compostos alifàtics pot contribuir a les propietats impermeabilitzants de la peridermis. / The functional characterization of two genes in the periderm, the &#969;-hydroxylase CYP86A33 -candidate for the functionalization of the &#969;-terminal carbon of suberin aliphatic compounds- and the putative ketoacyl-CoA synthase StKCS6 -candidate for the elongation of VLCFA and derivatives of suberin and waxes of periderm- is performed by RNA interference-mediated silencing in potato The CYP86A33 deficiency leads to a great reduction of the main suberin monomers, the C18:1 &#969;-hydroxyacid and &#945;,&#969;-diacid, together with an overall decrease of the suberin total amount by 60%. The deficiency in these &#969;-oxidized fatty acids alters the typical suberin lamellar structure as well as the periderm water barrier function.StKCS6 deficiency leads to a decrease of suberin and wax compounds with chain-length C28 and higher and an increase of those with chain-length C26 and lower. This deficiency suggests that the aliphatics chain-length can contribute to the sealing properties of periderm.

Thesis (Ph.D.). / Written for the Dept. of Natural Resource Sciences. Title from title page of PDF (viewed 2009/06/11). Includes bibliographical references.

Submitted in fulfillment of the requirements for the Master's of Technology: Chemistry, M L Sultan Technikon, 1999. / Saturated long chain hydrocarbons, such as paraffin waxes, have a large variety of applications. These applications may, however, be restricted by certain properties of the wax such as brittleness and in compounding. Cross-linking of the long chains in waxes may provide improved physical properties and hence a wider application of these waxes / M