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When Work Supports Don't Support Work: A Case for Parental Health Coverage in Mississippi
One of the biggest challenges facing Mississippians is the limited public health care provisions for parents. Medicaid is restrictively low with eligibility levels at 46 percent of the Federal Poverty Level. Outside of Medicaid, Mississippi has no state health insurance program for parents. Moreover, the continual decline of employer-sponsored health insurance and the prohibitive costs of private health insurance have led many Mississippians to forego health coverage altogether. This situation has negative consequences not only for the health of parents, but for their family's economic security and well-being. This brief uses results from the Family Resource Simulator to analyze Mississippi's work support policies. It also identifies gaps in parental health insurance coverage and recommends policy reforms that could expand coverage among Mississippi's working parents
On the mechanism of Dehydroquinate synthase : a thesis presented to Massey University in partial fulfilment of the requirements for the degree of Master of Science in Chemistry
The aim of this thesis is to investigate the influence of fluorine substitution on the second reaction of the shikimate pathway catalysed by the enzyme 3-dehydroquinate synthase. The shikimate pathway is an essential pathway that is required for the synthesis of aromatic compounds in bacteria, microbial eukaryotes and plants. The enzyme, 3-dehydroquinate synthase, catalyses the second step of the shikimate pathway, the conversion of 3-deoxy-D-arabino-heptulosonate-7-phosphate (DAHP) into 3-dehydroquinate (DHQ).
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It has been reported that when (3S)-3-fluoro DAHP (where fluorine occupies the C3 axial position) is treated with the enzyme 3-dehydroquinate synthase, two products, the expected (6S)-6-fluorodehydroquinate (5) and its C1 epimer, (6S)-6-fluoro-1-epideydroquinate (6) are formed in a ratio of 2 : 1.
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The C1 epimer of 3-dehydroquinate was reported to be formed from the natural substrate DAHP in a solution reaction, but not in the enzyme catalysed reaction. Therefore, it has been suggested that fluorine substitution at the axial position on C3 stabilises the fluoroenolpyranose intermediate allowing the intermediate to dissociate from the enzyme and cyclise to complete the formation of (6S)-6-fluoro-1-epideydroquinate free in solution. The results reported in this thesis are from an investigation carried out to understand further the influence of fluorine orientation on the stereochemical outcome of the products in the dehydroquinate synthase reaction. (3S)-3-Fluoro DAHP was synthesised in large amounts using both chemical and enzymatic synthesis. This was achieved by treating the isomers of 3-fluoro phosphoenolpyruvate and D-erythrose 4-phosphate with DAHP synthase, the first enzyme of the shikimate pathway. The erythrose 4-phosphate was prepared by lead tetraacetate oxidation of D-glucose 6-phosphate. The isomers of 3-fluoro phosphoenolpyruvate were prepared from 3-bromo, 3-fluoropyruvic acid by the Perkow reaction. Then (3S)-3-3-fluoro DAHP was purified by anion exchange chromatography. The chemical synthesis of erythrose 4-phosphate and the isomers of 3-fluoro phosphoenolpyruvate and the enzymatic synthesis of (3S)-3- fluoro DAHP and its purification are discussed in Chapter Two. A recombinant Escherichia coli strain (pJB 14) was used to over-express the enzyme dehydroquinate synthase, and partial purification of the enzyme was achieved by anion exchange chromatography. Chapter Three describes the production and purification of the enzyme 3-dehydroquinate synthase. Purified (3S)-3-fluoru DAHP was treated with the E. coli enzyme 3-dehydroquinate synthase. Formation of both (6S)-6-fluorodehydroquinate and its C1 epimer was observed. The reaction was followed at different pH and temperature values. The ratio of products produced in the enzyme-catalysed reaction was monitored by
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F NMR spectroscopy. No significant change in the ratios was observed with the different conditions employed. The results from these experiments are discussed in Chapter Four. Our results are consistent with the hypothesis that the fluoroenolpyranose intermediate is released to the solution, where it cyclises without the constraint of an enzymatic template. To test this hypothesis unequivocally, further investigations are required and these are discussed in Future Directions.
[NB: Mathematical/chemical formulae or equations have been omitted from the abstract due to website limitations. Please read the full text PDF file for a complete abstract.
Effect of Environmental Exposures on the Aramid Fibre Kevlar
The effects of exposure of Kevlar 49 fibres to thermal, ultrasonic and chemical environments have been analysed. Both the tensile strength and the tensile modulus deteriorate with thermal exposures . However, the former is more sensitive than the latter. The prominent crystal structural changes induced by thermal exposures are reduction in crystallinity, molecular misalignment about the fibre axis, increase in the inter layer distance, changes in crystallite size and/or microstrain. Thermally induced macro changes include introduction of surface holes,
partial hollowness near the core, localised thinning, material loss in the vicinity of surface impurities etc . The structural changes could be satisfactorily correlated with the corresponding changes in tensile properties . All the thermally induced effects are controlled by two parameters, viz ., the temperature (T) and the duration of the cumulative exposure to T, te,,,,,(T). The T-tcam(T) effect leads to the observation of isothermal decomposition of Kevlar over a range of temperatures which include T's, far below the reported decomposition temperature of 500/550 °C. A hitherto unknown direct correlation between X-ray diffraction peak positions and the tensile strength has also been identified . Exposure to ultrasonic waves introduces axial compression, evinced by the formation of kink bands, fibrillation and macro buckling . The unit cell of axially compressed fibres manifests an anisotropic deformation. The process of moisture uptake by Kevlar 49 fibres is controlled by the relative humidity (RH) of
ambient atmosphere . The saturation moisture content is, however, determined by structural characteristics such as the degree of crystallinity, molecular alignment etc . The uptake of common organic solvents by Kevlar is dependent on the molar volume of the former
Women in Aerospace in India: Aerowoman
The main objective of the seminar was to bring together the Indian women in the field of aerospace and identify their scientific and technical contributions. In this context, the seminar was perhaps the first of its kind held in India. It was also aptly conducted in the x2018;Womenx2019;s Empowerment Year x2013; 2001x2019; declared by the Govt. of India.13
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