Theses and Dissertations
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PublicationWomen's participation in the informal sector of Uzbekistan( 1997)Newly independent Uzbekistan is encountering increasingly complex challenges since 1991. As with many former Soviet republics, Uzbekistan has faced the loss of security, markets, resources and structure, making the transition to a market economy exceedingly difficult. The resultant pressures on individuals and families are evident. The role of Uzbek women in society has also changed significantly with the political and religious changes of the country. During Communist influence, Uzbek women saw their role as caretakers of the home transformed into one of active membership in the socialist economy. Despite the transformations of her participation in society, the Uzbek woman has remained the spiritual leader of the family, ultimately responsible for the safety and welfare of her children. It is in this capacity that she has established a long and stable history in the informal sector of the economy where she often has turned in an attempt to increase resources available to her household. Women's participation in the informal sector of the economy is evident since independence, despite the return to Uzbek and Islamic traditions. This economic activity by women, has been an incremental method of adaptation for Uzbek families who face economic hardship due to independence. This paper focuses on women's participation in the informal sector of the economy of Uzbekistan, against the backdrop of the changes that have recently taken place in the country, and in consideration of the future possibilities. A better understanding of the changing economic role for women can aid in drawing a clear picture of the impact of a changing economy on the society, and can add insight into adaptive strategies adopted by those most affected by the changes.
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PublicationIdentification, characterization and mapping of Ecm1, a locus affecting extracellular matrix production and lesion size in Cochliobolus heterostrophus( 1997)A mutant of Cochliobolus heterostrophus lacking the outer layer of extracellular matrix around its germ tubes and hyphae was obtained by mutagenizing protoplasts. The mutant not only lacks the outer matrix, but also produces much smaller lesions on corn leaves than non-mutant strains; the area of mutant lesions averages 0.6 mm² compared to 5.8 mm² for non-mutant lesions. Genetic analysis demonstrated that the failure to produce the outer matrix co-segregates with the reduced lesion size, indicating that the two traits are controlled by the same locus, designated Ecml (extracellular matrix deficient). The mutant retains normal growth on media and normal abilities to germinate, form appressoria, and penetrate corn leaves. This indicates that the outer matrix is not necessary for infection prior to entrance of the fungus into the leaf It also indicates that the pathogenicity defect in this mutant is manifested after penetration. To facilitate future tests of whether the pathogenicity defect is caused by the lack of the outer matrix, Ecml was mapped. Seven markers linked to Ecm1 were found by analysis of amplified fragment length polymorphisms (AFLP). Ecm1 maps to chromosome 4; the closest markers to Ecm1 are 5 cM distant, estimated to represent about 115 kb.
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PublicationAdaptive resonance neural networks and their applications in cell formation problem( 1997)Several ART models and modifications have been applied to CF problem and each has its advantages and disadvantages. How these models perform need to be studied and compared. Furthermore, some modifications claimed that they remedy the problems associated with the original proposed ART-1 model. There is a need to further scrutinize these modifications for the following reasons: (1) some variations did not provide sufficient experimental evidences; (2) they were tested in different environment and with different data sets and (3) the comparisons of these modifications could help select the appropriate models for specific CF problems and uncover new ideas to improve the ART paradigm. The purpose of this thesis is to provide answers to the above questions by evaluating different version of ART nets; (2) compare some existing ART-I approaches to CF problem and discuss the advantages and disadvantages of each method; (3) propose a new modification to ART-1 net aimed at solving CF problem; and (4) probe into the ART architectures to explore potential topics for further study and refinements.
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PublicationDNA typing by capillary electrophoresis( 1997)We demonstrate a genetic typing method based on capillary electrophoresis/laserinduced fluorescence (CE-LIF). VNTR polymorphism in the human D1S80 locus was studied. A poled allelic ladder, which contains the 27 most common human alleles, was used as the absolute standard. Extracted genomic DNA from an individual was amplified by polymerase chain reaction (PCR). Typing can be accomplished by co-injection of the PCR product and the D1S80 ladder and then running CE. Separation by a polymer solution of poly(ethylene oxide) in uncoated fused -silica capillaries allows high-resolution, repeated runs in the same capillary. Sensitive detection with monimal sample preparation is possible by using ethidium bromide as the intercalating dye. Statistical analysis of the data indicates a high level of confidence in matching the bands despite variations in the injection process or the CE system. Future adaptation to a multiplecapillary array system should allow high-speed, high-throughput operation.
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PublicationAn economic analysis of a biosolids and biomass system( 1997)Production of municipal waste (biosolids) is a fact of life. There are several ways to dispose of or use biosolids, including to forest and crop lands. An alley cropping agroforestry system which is associated with the Ames, Iowa Water Pollution Control Facility, and utilizes biosolids as crop-enhancing nutrient source, and is evaluated in terms of its economic feasibility. This agroforestry system consists of fast - growing hybrid poplar and perennial grasses (switchgrass or reed canarygrass) or hybrid poplar and a corn/soybean rotation. To assess the economic feasibility of land application ofbiosolids to the agroforestry system, twelve models consisting of different tree/crop combination (hybrid poplar/reed canarygrass, hybrid poplar/switchgrass, hybrid poplar/soybean following com) at four different rotation lengths (7 - 10 years) are evaluated. Annual equivalent value (AEV) decision criteria are applied to each model. Opportunity cost associated land is assumed to be $0/ac/yr. Biosolids are assumed to replace 80 percent of the fertilizer needed by woody biomass, herbaceous biomass, and the annual row crops. Almost all of the models have positive AEVs at both discount rates 5% and 7%. Sensitivity analyses test the effect of yield, price of biomass and crops, and land rent on the AEV s of selected models. The land application of biosolids to an agroforestry system is promising. It is profitable based on certain assumptions. Moreover, it reduces the environmental impact of biosolids disposal to a certain degree, and uses the waste as a fertilizer that has value to an agroforestry system.