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Evaluation of specificity of a walnut antiserum and detection of English walnut (Juglans regia) in food with ELISA and Real-Time PCRFernandez Ramirez, Juliana Esmeralda January 2009 (has links)
<p>Nuts of all kinds are common ingredients in food. For nut allergy sufferers the frequent use of nuts cause problems and "hidden" nuts in food products may elicit allergic reaction when such foods are consumed. Methods for detecting and quantifying walnut (and other nuts) with high sensitivity and specificity are therefore very important.</p><p>The objective of this project was to verify the specificity of a rabbit antiserum against walnut with immunodiffusion and to determine the size of the dominant walnut antigens with Western blotting. In addition, a commercial sandwich ELISA for walnut quantification was validated and compared with a qualitative real-time PCR.</p><p>The rabbit antiserum proved to be less specific but after absorption with cross-reacting nuts and seeds it showed high specificity. The ELISA kit reacted, except for walnut, with pecan and slightly with other nuts and seeds tested. The PCR showed an absolute specificity to walnut. As low levels as 2.5mg walnut/kg can be quantified with the ELISA. This is 8 to 100 fold less than with the PCR method. It is therefore concluded that the ELISA kit is more sensitive than the PCR method but the PCR method is more specific than the ELISA kit.</p>
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Evaluation of specificity of a walnut antiserum and detection of English walnut (Juglans regia) in food with ELISA and Real-Time PCRFernandez Ramirez, Juliana Esmeralda January 2009 (has links)
Nuts of all kinds are common ingredients in food. For nut allergy sufferers the frequent use of nuts cause problems and "hidden" nuts in food products may elicit allergic reaction when such foods are consumed. Methods for detecting and quantifying walnut (and other nuts) with high sensitivity and specificity are therefore very important. The objective of this project was to verify the specificity of a rabbit antiserum against walnut with immunodiffusion and to determine the size of the dominant walnut antigens with Western blotting. In addition, a commercial sandwich ELISA for walnut quantification was validated and compared with a qualitative real-time PCR. The rabbit antiserum proved to be less specific but after absorption with cross-reacting nuts and seeds it showed high specificity. The ELISA kit reacted, except for walnut, with pecan and slightly with other nuts and seeds tested. The PCR showed an absolute specificity to walnut. As low levels as 2.5mg walnut/kg can be quantified with the ELISA. This is 8 to 100 fold less than with the PCR method. It is therefore concluded that the ELISA kit is more sensitive than the PCR method but the PCR method is more specific than the ELISA kit.
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Mechanics of Light Weight Proppants: A Discrete ApproachKulkarni, Mandar 2012 May 1900 (has links)
Proppants are a specific application of granular materials used in oil/gas well stimulation. Employment of hard and soft particle mixtures is one of the many approaches availed by the industry to improve fracture resistance and the stability of the granular pack in the hydraulic fracture. Current industrial practices of proppant characterization involve long term and expensive conductivity tests. However, the mechanics governing the proppant pack response, in particular the effects due to material, shape and size of particles on the pack porosity, stiffness and particle fragmentation are not understood clearly.
The present research embodies analytical and experimental approach to model hard (ceramic) and soft (walnut shell and/or pure aluminum) proppant mixtures by taking into account polydispersity in size, shape and material type of individual particles. The hydraulic fracture condition is represented through confined compression and flowback loads. The particle interactions clearly illustrate changes in pore space as a function of pressure, mixture composition and friction. Single particle compression tests on individual particles are carried out to obtain mechanical properties which are incorporated into the finite element models and are further correlated with the compression/crush response of the mixture. The proppant pack stiffness and particle fragmentation depends strongly on the mixture composition as illustrated in the models and experiments. The flowback models demonstrated that the formation of a stable arch is essential to pack stability. Additional variables that enhance flowback resistance are identified as: addition of softer particles to a pack, softer rock surfaces and higher inter-particle friction. The computational studies also led to the discovery of better, and more efficient pack compositions such as - short and thin pure Al needles/ceramic and the pistachio shells/ceramic mixtures. These analytical results have generated great interest and are engaged in the design of experiments to formulate future proppant pack mixtures at Baker Hughes Pressure Pumping, Tomball, TX.
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Optimizing denitrification at Austin’s Walnut Creek Wastewater Treatment PlantHughes, Mark Patrick, 1986- 20 December 2010 (has links)
In natural waters, high concentrations of ammonia are toxic to fish, and the oxidation of ammonia to nitrate (NO₃-) consumes large quantities of dissolved oxygen. The influent to municipal wastewater treatment plants in the United States typically contains approximately 40 mg/L of ammonia nitrogen (NH₃₋ N). Almost all of this ammonia must be removed in a wastewater treatment process before the effluent is discharged to the natural environment. This dramatic decrease is accomplished by the aerobic biological process of nitrification, in which ammonia is oxidized to nitrate Biological denitrification is an anoxic biological process in which nitrate (NO₃-) is reduced to nitrogen gas (N₂). Denitrification can increase the alkalinity in activated sludge aeration basins and decrease the concentration of filamentous organisms. The staff at the City of Austin Water Utility decided to implement a denitrification system at Walnut Creek Wastewater Treatment Plant to control filamentous organisms and increase the alkalinity within the aeration basins. The denitrification configuration that the staff implemented was unconventional because no structural changes were made to the aeration basins to encourage denitrification. However, the system functioned well and allowed operators to turn off one of the two air blowers, which saves the plant a significant amount of energy. The current operation has occasional problems, where the alkalinity in the aeration basin decreases or the effluent ammonia increases. When the alkalinity decreases to the point where the pH drops to near 6.0, operators are forced to add chemicals to increase the alkalinity. When the effluent ammonia increases to near the permitted concentration (2.0 mg NH₃-N/L),operators are forced to turn back on the second blower which eliminates the anoxic zone. These problems occur most often during the winter, when the wastewater is the coldest. The wastewater temperature at Walnut Creek varies from a high of 30°C during the summer to a low of 18°C during the winter. The goal of this research was the identification of ways to make the operation more robust which would prevent the need for chemical addition and minimize the use of the second blower. Laboratory-scale reactors were operated to assess possible improvements that could be made to the operation and configuration of the denitrification system at Walnut Creek. The data observed in the laboratory scale experiments showed that the population of denitrifying bacteria limits denitrification and is especially important during the winter. Increasing the solids retention time to 20 days appeared to be the best way to increase the population of denitrifying bacteria and improve denitrification. Improvements can also be made by increasing the volume of the anoxic zone. Increasing the volume of wastewater and biomass recycled will most likely not benefit denitrification until other improvements have been made. Recommendations to the City of Austin Water Utility include the following: 1) increase the solids retention time at Walnut Creek, 2) Increase the volume of the anoxic zone, 3) Separate the anoxic zone from the aerobic section of each aeration basin, 4) During the winter, operate the flow equalization basins to reduce the dissolved oxygen entering the anoxic zone, 5) Continually mix some of the effluent from the aeration basins with the primary effluent in the flow equalization basins. / text
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Late Cenozoic stratigraphy and structure of a part of the Walnut Grove Basin, Yavapai County, ArizonaHook, Donald Lewis, 1932- January 1956 (has links)
No description available.
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Juglans regia L : genetic variation and provenance performanceHemery, Gabriel E. January 2000 (has links)
A range-wide collection of Juglans regia seeds was undertaken in autumn 1997 from 12 countries, including 25 provenances and 375 half-sib progenies. 2200 seedlings were produced using innovative nursery techniques. The seedlings were planted in three provenance trials in southern England in 1999, the largest of which acted as a combined provenance/progeny trial. After one growing season, survival was 98.9 %, mean height growth 35 cm, and mean stem diameter increment 5 mm. Provenance differences for both height and stem diameter increment were highly significant (p<0.001). There were no significant genotype × environment interactions. Flushing assessments revealed few significant differences between provenances and flushing was complete by early April. Family heritability for tree height was 0.19 at one site and, with combined selection, genetic gain was estimated at 8 %. The effects of three types of treeshelter and a stumping treatment on walnut establishment were tested over three growing seasons. Treeshelters were found beneficial to height increment. However, 120 cm tall shelters promoted early flushing, and consequent risk of increased frost damage, and caused more stem die-back than 75 cm shelters. Stumping promoted rapid early height increment but gave no longer-term benefit. The crown (cd) and stem (dbh) diameter at breast height relationship of open growing trees in Britain was assessed and was highly significant (r2 = 0.96, p<0.001). The regression equation (cd = 2.71 + 17.6dbh) permitted the estimation of suitable planting densities for the provenance trials and the calculation of a thinning regime. Isozyme analysis of the 375 genotypes identified 20 loci in 15 enzyme systems with seed embryo extracts. Using young leaf extracts, the polymorphic locus Pgm-1 indicated low expected heterozygosity of 0.06 both within populations and at the species level. FST and GST estimates, both 0.05, indicated high uniformity among populations. Genetic distance estimates did not identify significant clustering consistent with geographic origin.
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Ratlarda diyeter ceviz alımının hipokampüs NMDA reseptör subünit konsantrasyonları üzerine etkisi /Hiçyılmaz, Hicran. Vural, Hüseyin. January 2007 (has links) (PDF)
Tez (Tıpta Uzmanlık) - Süleyman Demirel Üniversitesi, Tıp Fakültesi, Biyokimya Anabilim Dalı, 2007. / Bibliyografya var.
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Root-to-shoot communication in response to drought : a comparison of four central hardwood tree species /Loewenstein, Nancy J., January 1996 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 1996. / Typescript. Vita. Includes bibliographical references (leaves 185-200). Also available on the Internet.
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Root-to-shoot communication in response to drought a comparison of four central hardwood tree species /Loewenstein, Nancy J., January 1996 (has links)
Thesis (Ph. D.)--University of Missouri-Columbia, 1996. / Typescript. Vita. Includes bibliographical references (leaves 185-200). Also available on the Internet.
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Hydrological processes inferred from water table fluctuations, Walnut Creek, IowaSchilling, Keith Edwin. Zhang, You-Kuan. January 2009 (has links)
Thesis supervisor: You-Kuan Zhang. Includes bibliographic references (p. 158-172).
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