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Modeling the "Make-or-Buy" Logistics Decision: An Empirical Analysis of the Logistic Decision Drivers for Suppliers and Manufacturers in Vendor Managed Inventory Relationships
Managing the movement of components and products from suppliers to customers and ultimately to end-users is undergoing rapid changes. Supply chain management has increasingly gained attention as companies have sought to reduce costs and improve service performance in a quest for gaining an advantage on the competition. digital.library.unt.edu/ark:/67531/metadc278404/
Modeling the Relationship Between Golden Algae Blooms in Lake Texoma, Usa, Versus Nearby Land Use and Other Physical Variables
Pyrmnesium parvum, commonly known as golden algae, is an algal species that under certain circumstances releases toxins which can lead to fish kills and the death of other economically and ecologically important organisms. One of the major objectives of the study was to investigate whether a relationship exists between land use and Prymnesium parvum abundance in littoral sites of Lake Texoma, USA. Another objective was to investigate whether a relationship exists between other physical variables and counts of P. parvum. Lastly, developing a valid model that predicts P. parvum abundance was an objective of the study. Through stepwise regression, a small but highly significant amount of the variation in P. parvum counts was found to be explained by wetlands, soil erodibility and lake elevation. The developed model provides insight for potential golden algae management plans, such as maintaining wetlands and teaching land owners the relationship between soil erosivity and golden algae blooms. digital.library.unt.edu/ark:/67531/metadc149683/
Modeling the role of blogging in librarianship
This phenomenological study examines the motivations and experiences of librarians who author professionally-focused Weblogs. I constructed a model of librarianship based on Wilson and Buckland. The results show a close fit between librarian bloggers and the ideals of the field as expressed by two primary library and information science philosophers. A Web survey generated 239 responses to demographic and open-ended questions. Using the results of the survey, I analyzed demographic data and performed a phenomenological analysis of the open-ended questions. A list of category responses was generated from each set of answers via the coding of descriptive words and phrases. Results indicated the motivations of librarian bloggers are based around themes of sharing, participation in community, and enhanced professional development. Respondents reported feeling more connected to the profession and to colleagues across the world because of blogging. Respondents perceived the librarian blogosphere as a community with both positive aspects - feedback, discussion, and support - and negative aspects - insular voices, divides between technologists and librarians, and generational rifts. Respondents also reported an increased ability to keep current, improved writing skills, and opportunities to speak and contribute to professional journals. digital.library.unt.edu/ark:/67531/metadc3915/
Modeling Transition Metal Catalysts for Small Molecule Activation and Functionalization
There is a high demand for the development of processes for the conversion of ubiquitous molecules into industrially useful commodities. Transition metal catalysts are often utilized for the activation and functionalization of small organic molecules due to their diverse nature and proven utility with a myriad of chemical transformations. The functionalization of methane (CH4) and dinitrogen (N2) to methanol (CH3OH) and ammonia (NH3) respectively is of particular interest; however, both methane and dinitrogen are essentially inert due to the inherit strength of their bonds. In this dissertation a series of computational studies is performed to better understand the fundamental chemistry behind the functionalization of methane and the activation of dinitrogen in a homogeneous environment. A catalytic cycle is proposed for the oxy-functionalization of methane to methanol. The cycle consists of two key steps: (1) C-H activation across a metal-alkoxide bond (M-OR), and (2) regeneration of the M-OR species through an oxy-insertion step utilizing external oxidants. The C-H activation step has been extensively studied; however, the latter step is not as well understood with limited examples. For this work, we focus on the oxy-insertion step starting with a class of compounds known to do C-H activation (i.e., Pt(II) systems). Computational studies have been carried out in an attempt to guide experimental collaborators to promising new systems. Thus, the majority of this dissertation is an attempt to extend transition metal mediated C-O bond forming reactions to complexes known to perform C-H activation chemistry. The last chapter involves a computational study of the homogeneous cleavage of N2 utilizing iron-?-diketiminate fragments. This reaction has been studied experimentally, however, the reactive intermediates were not isolated and the mechanism of this reaction was unknown. Density functional theory (DFT) calculations are carried out to elucidate the mechanism of the reductive cleavage of N2 via the sequential addition of iron- ?-diketiminate fragments to N2 to form a bis-nitride (N3-) intermediate. The role of potassium promoters on the dinitrogen and bis-nitride species is also investigated. digital.library.unt.edu/ark:/67531/metadc271814/
Modeling Transition Metal Chemistry for Catalytic Functionalization of Molecules
The diversity of transition metal complexes allows for a wide range of chemical processes to be mediated by the metal, from catalysis to surface chemistry. Investigations into the structure and electronic configuration of transition metal complexes allow for tuning of desired species by modifications to the ligands and/or metals to achieve more efficient thermodynamics and kinetics for the process of interest. Transition metals, often used in catalysts for a number of important processes, require detailed descriptions of intermediates, transition states and products to fully characterize a reaction mechanism(s) in order to design more active and efficient catalysts. Computational investigations into inorganic catalysts are explored with the aim of understanding the activity of each species and how modifications of supporting ligands, co-ligands and metals vary the interaction along the reaction pathway. Reported results give important insight into the development of the most active complexes in addition to determining the least active complexes to aid experimental development. This report first investigates the mechanisms of two unique transfer reactions: 1) formation of low coordinate nickel-nitrene ((P~P)Ni=NR; P~P = 1,2-bis(dihydrophosphino)-ethane or 1,2-bis(difluoromethylphosphino)-ethane) complexes as catalysts for nitrogen atom transfer and 2) oxidation of a triphosphorus niobium complex, [(η2-P3SnPh3)Nb(OMe)3], for the transfer of the phosphorus synthon, Ph3SnP3. These reactions have utility in the synthesis of nitrogen and phosphorus containing molecules, respectively, and the results presented provide mechanistic insight into the synthesis of the organometallic intermediates. Additionally, a computational approach towards rational catalyst design was performed on the ruthenium based hydroarylation catalyst TpRu(CO)(Ph) [Tp = hydrido-tris(pyrazolyl)borate]. Targeted modifications at the Tp, metal and co-ligand (CO) sites were studied in order to tune the electronics and sterics of the catalyst. Modifications, through computational methods, provided a more cost- and time-efficient way to study the impact of modifications, which provided direct input into attractive synthetic targets. The research described heir in highlights the use of computational chemistry methodologies, specifically DFT, in collaboration with experimental results, for the accurate description of reaction geometries and factors influencing the thermodynamics and kinetics of the systems. Valuable insight is gained by treating inorganic complexes with theoretical methods and additionally provides a fast, cheap way to predict and understand the chemistry of such complex systems. digital.library.unt.edu/ark:/67531/metadc84255/
Modeling utilization of planned information technology
Implementations of information technology solutions to address specific information problems are only successful when the technology is utilized. The antecedents of technology use involve user, system, task and organization characteristics as well as externalities which can affect all of these entities. However, measurement of the interaction effects between these entities can act as a proxy for individual attribute values. A model is proposed which based upon evaluation of these interaction effects can predict technology utilization. This model was tested with systems being implemented at a pediatric health care facility. Results from this study provide insight into the relationship between the antecedents of technology utilization. Specifically, task time provided significant direct causal effects on utilization. Indirect causal effects were identified in task value and perceived utility constructs. Perceived utility, along with organizational support also provided direct causal effects on user satisfaction. Task value also impacted user satisfaction in an indirect fashion. Also, results provide a predictive model and taxonomy of variables which can be applied to predict or manipulate the likelihood of utilization for planned technology. digital.library.unt.edu/ark:/67531/metadc2496/
Modeling wild type and mutant glutathione synthetase.
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Glutathione syntethase (GS) is an enzyme that belongs to the ATP-grasp superfamily and catalyzes the second step in the biosynthesis of glutathione. GS has been purified and sequenced from a variety of biological sources; still, its exact mechanism is not fully understood. Four highly conserved residues were identified in the binding site of human GS. Additionally, the G-loop residues that close the active site during catalysis were found to be conserved. Since these residues are important for catalysis, their function was studied computationally by site-directed mutagenesis. Starting from the reported crystal structure of human GS, different conformations for the wild type and mutants were obtained using molecular dynamics technique. The key interactions between residues and ligands were detected and found to be essential for enzyme activity. digital.library.unt.edu/ark:/67531/metadc5556/
Models to Combat Email Spam Botnets and Unwanted Phone Calls
With the amount of email spam received these days it is hard to imagine that spammers act individually. Nowadays, most of the spam emails have been sent from a collection of compromised machines controlled by some spammers. These compromised computers are often called bots, using which the spammers can send massive volume of spam within a short period of time. The motivation of this work is to understand and analyze the behavior of spammers through a large collection of spam mails. My research examined a the data set collected over a 2.5-year period and developed an algorithm which would give the botnet features and then classify them into various groups. Principal component analysis was used to study the association patterns of group of spammers and the individual behavior of a spammer in a given domain. This is based on the features which capture maximum variance of information we have clustered. Presence information is a growing tool towards more efficient communication and providing new services and features within a business setting and much more. The main contribution in my thesis is to propose the willingness estimator that can estimate the callee's willingness without his/her involvement, the model estimates willingness level based on call history. Finally, the accuracy of the proposed willingness estimator is validated with the actual call logs. digital.library.unt.edu/ark:/67531/metadc6095/
Moderators of the sociocultural internalization-body dissatisfaction relationship among female undergraduates.
The sociocultural model of eating pathology is an empirically-supported model explaining eating disorder etiology. The model poses that body dissatisfaction and subsequent eating pathology stems from the unrealistic standards formulated by Westernized society. Although the model has strong empirical support, variables within the model do not account for 100% of the variance in disordered eating. Thus, the current researcher attempted to explore potential moderating factors in the sociocultural model of eating disorders that may help to explain variance currently unaccounted for. In particular, the researcher focused on the relationship between sociocultural internalization and body dissatisfaction, given that this relationship has not been previously explored within the literature. Based on theoretical support, the researcher chose several potential variables to test, including perfectionism, neuroticism, body surveillance, and shame. Primary analyses tested each variable for moderating effects using hierarchical moderated regression, but no significant findings were shown. Results of post hoc analyses showed all variables had significant mediating effects, with the exception of self-oriented perfectionism. The discussion section addresses consistency with previous research, limitations of the present study, treatment implications and guidelines for future research. digital.library.unt.edu/ark:/67531/metadc12147/
Modern Api Design and Physical Computing Techniques in Just Intonation Performance Practice
approached previously by both Harry Partch and Ben Johnston, and proposes the decoupling of interface and sound production as a way forward. The design and implementation of a software instrument and a hardware prototype are described, both using a simple API for variable tuning instruments. The hardware prototype uses physical computing techniques to control the tuning of a string with a servo motor, while the software instrument exists entirely in a web browser. Finally, potential algorithms for clients of the API are presented, and the effectiveness of the hardware prototype is evaluated by measuring its pitch accuracy. digital.library.unt.edu/ark:/67531/metadc271901/
Modern Chinese Piano Composition and Its Role in Western Classical Music: A Study of Huang An-lun's Piano Concerto No. 2 in C minor, Op. 57
China's role in Western music is ever-expanding. Echoing the growth of classical music in China is the importance of Chinese musicians in the global music world. However, it is easy to forget that Western classical music is a foreign import to China, one that has been resisted for most of its history. The intent of this study is to evaluate the role of Chinese music in the Western classical world. This includes Western education, Western repertoire, and also a historical exploration into the mutual influence of the two styles. One Chinese composition in particular, Huang An-lun's Piano Concerto No. 2 in C minor, Op. 57, is selected to analyze the Western and Chinese elements present in the work. This analysis will shed light on the relationship of the two styles and how they amalgamate in modern Chinese music. Although Western classical music today has a strong foothold in China, Chinese contributions to piano literature are largely unknown to the West. China possesses one of the richest musical histories in the world, one which until the twentieth century has largely remained unaffected by Western elements. Its musical heritage extends over thousands of years, deeply rooted in tradition and nationalism. Over the last century, Chinese composition began to incorporate Western musical ideas while still holding on to its own heritage and traditions. This synthesis of Western and Chinese musical elements created a new compositional sound founded on Chinese roots. Huang An-lun, one of China's most prominent living composers, embodies this style in his compositions. Chinese composition is no longer something that is exotic or alien to Western music. Instead, it integrates many Western ideas while still being founded in Chinese heritage, creating a new style that has much to offer the Western classical world. digital.library.unt.edu/ark:/67531/metadc5494/
Modern Problems and Practices of Management as Revealed in Selected Contemporary American Novels
This study is an examination of the hypothesis that selected contemporary American novels offer vivid illustrations of modern problems and practices of management as seen in business and industry. Too often, university management courses treat management processes as isolated cases in limited and static settings. Novelists, on the other hand, treat these same processes in a broader context and often deal quite subtly and perceptively with everything from the mammoth corporation to the single proprietorship. Students proposing to become businessmen, therefore, should benefit from this novelistic perspective so frequently overlooked. digital.library.unt.edu/ark:/67531/metadc164538/
Modes of Resolving Motor Conflict Situations, Certain Personality Variables, and Scholastic Achievement
This was a study of modes of resolving experimentally induced motor conflict situations, certain personality variables, and scholastic achievement of a group of college students. digital.library.unt.edu/ark:/67531/metadc164211/
Modest Musorgsky's Early Songs: Uncommon Lyricisms Within a Simple Framework
Modest Musorgsky is considered a composer of masterful vocal, symphonic, and piano works. His songs and song cycles distinguish themselves as evocative of the broad spectrum of Russian experience. However, Musorgsky's early songs have not received as much attention as his larger works, such as Boris Godunov or Pictures at an Exhibition. Musorgsky's early songs, from 1857-1867, show the composer's affinity for lyrical expression, be it brightly melodious, impassioned, or within a comical or satirical vein. He portrays Russian life through a mixture of different genres such as the Russian romance, the ballad, the operatic aria, and also vaudeville. This study focuses on Musorgsky's choice of texts, his penning of several of them, and the way he incorporates them within each song. digital.library.unt.edu/ark:/67531/metadc177206/
Modification of Disruptive Talking, Employing the Opportunity to Work as a Reinforcing Stimulus
The purpose of this study was to test the effectiveness of "work" as a reinforcing stimulus in a behavior modification program designed to eliminate disruptive talking. A response-cost procedure was established whereby the reinforcement was made contingent upon the behavior of eight students with learning disabilities. digital.library.unt.edu/ark:/67531/metadc131653/
Modification of Graphene Properties: Electron Induced Reversible Hydrogenation, Oxidative Etching and Layer-by-layer Thinning
In this dissertation, I present the mechanism of graphene hydrogenation via three different electron sources: scanning electron microscopy, e-beam irradiation and H2 and He plasma irradiation. in each case, hydrogenation occurs due to electron impact fragmentation of adsorbed water vapor from the sample preparation process. in the proposed model, secondary and backscattered electrons generated from incident electron interactions with the underlying silicon substrate are responsible for the dissociation of water vapor. Chemisorbed H species from the dissociation are responsible for converting graphene into hydrogenated graphene, graphane. These results may lead to higher quality graphane films having a larger band gap than currently reported. in addition, the dissertation presents a novel and scalable method of controllably removing single atomic planes from multi-layer graphene using electron irradiation from an intense He plasma under a positive sample bias. As the electronic properties or multi-layer graphene are highly dependent on the number of layers, n, reducing n in certain regions has many benefits. for example, a mask in conjunction with this thinning method could be used for device applications. digital.library.unt.edu/ark:/67531/metadc115101/
Modification of Transsexualism: A Behavior Modification Program for Conditioning Masculine Behaviors in an Effeminate Boy
Operant conditioning techniques were used to condition male-typical behaviors in an eight-year-old effeminate boy who had been described as transsexual. A probe of toys and activities was administered, which showed a trend toward his choosing feminine toys and activities. The two phases consisted of positive reinforcement of behavior associated with masculinity. digital.library.unt.edu/ark:/67531/metadc131511/
Modifications of epoxy resins for improved mechanical and tribological performances and their effects on curing kinetics.
A commercial epoxy, diglycidyl ether of bisphenol-A, was modified by two different routes. One was the addition of silica to produce epoxy composites. Three different silane coupling agents, glycidyloxypropyl trimethoxy silane (GPS), -methacryloxypropyl trimethoxy silane (MAMS) and 3-mercaptopropyltriethoxy silane (MPS), were used as silica-surface modifiers. The effects of silica content, together with the effects of chemical surface treatment of silica, were studied. The results indicate that epoxy composites with silica exhibit mechanical and tribological properties as well as curing kinetics different than the pure epoxy. The optimum silica content for improved mechanical and tribological properties (low friction coefficient and wear rate) was different for each type of silane coupling agent. An unequivocal correlation between good mechanical and improved tribological properties was not found. Activation energy of overall reactions was affected by the addition of silica modified with MAMS and MPS, but not with GPS. The second route was modification by fluorination. A new fluoro-epoxy oligomer was synthesized and incorporated into a commercial epoxy by a conventional blending method. The oligomer functioned as a catalyst in the curing of epoxy and polyamine. Thermal stability of the blends decreased slightly at a high oligomer content. Higher wear resistance, lower friction coefficient and higher toughness were found with increasing oligomer content; thus in this case there was a correlation between good mechanical and improved tribological properties. The results indicated that increasing toughness and formation of a transfer film contribute to improved tribological performances. digital.library.unt.edu/ark:/67531/metadc6123/
Modified epoxy coatings on mild steel: A study of tribology and surface energy.
A commercial epoxy was modified by adding fluorinated poly (aryl ether ketone) and in turn metal micro powders (Ni, Al, Zn, and Ag) and coated on mild steel. Two curing agents were used; triethylenetetramine (curing temperatures: 30 oC and 70 oC) and hexamethylenediamine (curing temperature: 80 oC). Variation in tribological properties (dynamic friction and wear) and surface energies with varying metal powders and curing agents was evaluated. When cured at 30 oC, friction and wear decreased significantly due to phase separation reaction being favored but increased when cured at 70 oC and 80 oC due to cross linking reaction being favored. There was a significant decrease in surface energies with the addition of modifiers. digital.library.unt.edu/ark:/67531/metadc12119/
The Modified Human Need Survey of Human Needs
This study was designed to test the hypothesis that desire is inversely proportional to satisfaction in the motivational category of a given person. The present study represents an attempt to devise an objectively scored test which will objectively and empirically determine the level of motivation of a given subject. digital.library.unt.edu/ark:/67531/metadc131431/
Modulation of the Coelomic Fluid Protein Profile in the Earthworm, Lumbricus Terrestris, After Exposure to Copper as Copper Sulfate
Proteomic techniques were used to analyze the protein profile of earthworm, Lumbricus terrestris, coelomic fluid collected by either whole body dissection method or the coelomic cavity puncture method. Data demonstrated that collection of coelomic fluid using the coelomic cavity puncture method protocol resulted in a 32% reduction, 377 +/- 4.5 vs 253+/- 19.9 (p=0.0007), in the number of individual proteins. It was determined that the coelomic cavity puncture method yielded a "cleaner" preparation, one less contaminated with extraneous proteins from intestinal tissue, gut contents, and body wall materials. This protocol was used in all later studies. The same proteomic techniques were used to evaluate the effects that exposure to Cu (1.0 μg/cm2) as CuSO4 had on the earthworm coelomic fluid profile. Comparison of protein profile from exposed earthworms demonstrated a significant reduction in the number of proteins expressed (184 ± 2.64 vs 253 ±19.9 p=0.0192) when compared to control organisms. Cu exposure also resulted in a modulation of the protein profile with treated earthworms expressing 47 new proteins that were not identified in unexposed worm coelomic fluid. Additionally, 116 proteins found in coelomic fluid collected from normal worms were absent in Cu exposed organisms. Finally, 137 proteins were conserved or found in both control and exposed organisms; however of these proteins, 24 were up-regulated, 105 were down-regulated, and 8 were unchanged as a result of Cu exposure. digital.library.unt.edu/ark:/67531/metadc28428/
Moisture Relations of the Soils of Denton County
In this research, study was made of representative soils of denton County (Texas) with the aim of correlating various soil-moisture factors through experimental analyses. Two accepted hypotheses of soil-moisture relations have been substantiated by experiment with Denton County soils. digital.library.unt.edu/ark:/67531/metadc29834/
Molecular and biochemical characterization of phospholipase D in cotton (Gossypium hirsutum L) seedlings.
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N-Acylethanolamines (NAEs) are enriched in seed-derived tissues and are believed to be formed from the membrane phospholipid, N-acylphosphatidylethanolamine (NAPE) via the action of phospholipase D (PLD). In an effort to identify a functional NAPE-PLD in cotton seeds and seedlings, we have screened a cotton seedling cDNA (cotyledon mRNA from 48 h dark grown seedlings) library with a 1.2 kb tobacco partial cDNA fragment encoding the middle third of a putative PLDβ/γ (genbank accession, AF195614) isoform. Six plaques were isolated from the Uni-ZAP lambda library, excised as pBluescript SK(-) phagemids and subjected to nucleotide sequence analysis. Alignment of derived sequences with Arabidopsis PLD family members indicated that the cDNAs represent six different PLD gene products -three putative PLD β isoforms and three putative PLD δ isoforms. The PLD β isoforms, designated Ghpldβ1a, GHpldβ1b and a truncated Ghpldβ1b isoform. Both the full-length PLD β proteins contained characteristic HKxxxxD catalytic domains, a PC-binding domain, a PIP2-binding domain and a C2 domain. In addition both cotton PLD β isoforms had a N-terminal "SPQY" rich domain which appeared to be unique to these PLDs. The three PLD δ isoforms, designated Ghpldδ1a, Ghpldδ1b and Ghpldδ1b-2 encode full-length PLDδ proteins, and like the above PLDs, contained the characteristic catalytic and regulatory domains. The expression of Ghpldδ1b showed hydrolytic and transphosphatidylation activity toward radiolabelled phosphatidylcholine (PC) but it appears Ghpldδ1b does not utilize NAPE as a substrate to produce NAEs nor does it seem to be suppressed by NAEs. digital.library.unt.edu/ark:/67531/metadc4732/
Molecular and Functional Characterization of Medicago Truncatula Npf17 Gene
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Legumes are unique among plants for their ability to fix atmospheric nitrogen with the help of soil bacteria rhizobia. Medicago truncatula is used as a model legume to study different aspects of symbiotic nitrogen fixation. M. truncatula, in association with its symbiotic partner Sinorhizobium meliloti, fix atmospheric nitrogen into ammonia, which the plant uses for amino acid biosynthesis and the bacteria get reduced photosynthate in return. M. truncatula NPF1.7 previously called MtNIP/LATD is required for symbiotic nitrogen fixing root nodule development and for normal root architecture. Mutations in MtNPF1.7 have defects in these processes. MtNPF1.7 encodes a member of the NPF family of transporters. Experimental results showing that MtNPF1.7 functioning as a high-affinity nitrate transporter are its expression restoring chlorate susceptibility to the Arabidopsis chl1-5 mutant and high nitrate transport in Xenopus laevis oocyte system. However, the weakest Mtnip-3 mutant allele also displays high-affinity nitrate transport in X. laevis oocytes and chlorate susceptibility to the Atchl1-5 mutant, suggesting that MtNPF1.7 might have another biochemical function. Experimental evidence shows that MtNPF1.7 also functions in hormone signaling. Constitutive expression of MtNPF1.7 in several species including M. truncatula results in plants with a robust growth phenotype. Using a synthetic auxin reporter, the presence of higher auxin in both the Mtnip-1 mutant and in M. truncatula plants constitutively expressing MtNPF1.7 was observed. Previous experiments showed MtNPF1.7 expression is hormone regulated and the MtNPF1.7 promoter is active in root and nodule meristems and in the vasculature. Two potential binding sites for an auxin response factors (ARFs) were found in the MtNPF1.7 promoter. Chromatin immunoprecipitation-qRT-PCR confirmed MtARF1 binding these sites. Mutating the MtARF1 binding sites increases MtNPF1.7 expression, suggesting a mechanism for auxin repression of MtNPF1.7. Consistent with these results, constitutive expression of an ARF in wild-type plants partially phenocopies Mtnip-1 mutants’ phenotypes. digital.library.unt.edu/ark:/67531/metadc407747/
Molecular and Kinetic Characterization of the Aspartate Transcarbamoylase Dihydroorotase Complex in Pseudomonas putida
Aerobic Gram negative bacteria such as Pseudomonas putida were reported to possess class A ATCases and to have a M.W. of 360 kD. The nucleotide sequence of the P. putida pyrBC was determined to answer this question once and for all. The expected regulatory gene was not found. It is shown that the P. putida pyrB gene is overlapped by pyrC by 4 bp. The P.putida pyrB is 1005 bp (335 aa) in length and the pyrC is 1275 bp (425 aa) long. Both of these genes complement E. coli mutants with their respective genotypes. Another finding borne out from the sequence is an effector binding site at the N-terminus of pyrB of P. putIda. The binding site shows that effectors compete with carbamoylphosphate for the active site. In this dissertation, it is shown that the ATCase of P.putida is a trimer of M.W. of 109 kD (3 x 36.4 kD) and that the gene encoding pyrB is overlapped by the pyrC gene which encodes DHOase. It is also shown that the pyrBC encoded enzymes copurify as a dodecameric complex with a M.W. of 484 kD. digital.library.unt.edu/ark:/67531/metadc277575/
Molecular Basis of Plant Defense Against Aphids: Role of the Arabidopsis Thaliana PAD4 and MPL1 Genes
Myzus persicae (Sülzer), commonly known as green peach aphid (GPA), utilizes its slender stylet to penetrate the plant tissues intercellularly and consume copious amounts of photoassimilates present in the phloem sap causing extensive damage to host plants. The compatible interaction between GPA and Arabidopsis thaliana enabled us to characterize plant response to aphid infestation. Upon GPA infestation, Arabidopsis PAD4 (PHYTOALEXIN DEFICIENT4) gene modulates premature leaf senescence, which is involved in the programmed degradation of cellular components and the export of nutrients out of the senescing leaf. Senescence mechanism is utilized by plants to limit aphid growth. In addition, PAD4 provides antixenosis (deters insect settling and feeding) and antibiosis (impair aphid fecundity) against GPA and adversely impact sieve element availability to GPA. Basal expression of PAD4 contributes to antibiosis, and the GPA-induced expression of PAD4 contributes to antixenosis. Mutation in the Arabidopsis stearoyl-ACP desaturase encoding SSI2 (suppressor of SALICYLIC ACID [SA] insensitivity2) gene that results in an accelerated cell death phenotype and dwarfing, also conferred heightened antibiosis to GPA. Results of this study indicate that PAD4 is required for the ssi2-mediated enhanced antibiosis to GPA. The PAD4 protein contains conserved Ser, Asp and His residues that form the catalytic triad of many α/β fold acyl hydrolases. Arabidopsis plants expressing mutant versions of PAD4 [PAD4(S118A) and PAD4(D178A)] supported higher numbers of GPA as compared to wild type (WT) plants in no-choice tests. Furthermore, Electrical Penetration Graph (EPG) studies revealed that S118 residue in PAD4 is essential to limit GPA feeding from the sieve elements. However, the ability to deter insect settling in choice tests was not impacted by the PAD4(S118A) and PAD4(D178A) mutations, thus suggesting that PAD4s involvement in deterring insect settling and in antibiosis are determined by separate regions of PAD4. The MPL1 (MYZUS PERSICAE INDUCED LIPASE1) gene is another critical component of Arabidopsis defense against GPA. Like PAD4, MPL1 expression is induced in response to GPA infestation. However, MPL1 is required only for antibiosis and is not essential for antixenosis against GPA. EPG analysis suggests that the mpl1 mutant allele does not impact aphid feeding behavior. Since, MPL1 exhibits lipase activity, and ssi2 petiole exudates contain elevated levels of antibiosis, we propose that antibiosis to GPA requires a lipid(s), or a product thereof. digital.library.unt.edu/ark:/67531/metadc84242/
Molecular cloning and analysis of the genes for cotton palmitoyl-acyl carrier protein thioesterase (PATE) and Δ-12 fatty acid desaturase (FAD2-3) and construction of sense and anti-sense PATE plasmid vectors for altering oilseed composition of transgenic cotton plants.
A cotton PATE cDNA clone has a 1.7-kb insert with an coding region for 410 amino acids, lacking codons for the three N-terminal amino acids. The predicted amino acid sequence of the PATE preprotein has a characteristic stromal-targeting domain and a 63% identity to the Arabidopsis FatB1 thioesterase sequence. A cotton genomic clone containing a 17.4-kb DNA segment was found to encompass a palmitoyl-ACP thioesterase (FatB1) gene. The gene spans 3.6 kb with six exons and five introns. The six exons are identical in nucleotide sequence to the open reading frame of the corresponding cDNA, and would encode a preprotein of 413 amino acids. The preprotein is identified as a FatB thioesterase from its deduced amino acid sequence similarity to those of other FatB thioesterase preproteins. A 5'-flanking region of 914 bp was sequenced, with the potential promoter/enhancer elements including basic helix-loop-helix elements (E box). Alkaline blot hybridization of cotton genomic DNA suggests the presence at least two FatB1 thioesterase genes in cotton. Four plasmid constructs for both constitutive and seed-specific anti-sense RNA suppression and gene-transgene co- suppression of PATE gene expression were successfully generated. Two overlapping cotton genomic clones were found to encompass a Δ-12 fatty acid desaturase (FAD2-3) gene. The continuous FAD2-3 coding region is 1,155 bp and would encode a protein of 384 amino acids. The FAD2-3 gene has one large intron of 2,967 bp entirely within its 5'-untranslated region. Several potential promoter/enhancer elements, including several light responsive motifs occur in the 5'-flanking region. Yeast cells transformed with a plasmid construct containing the cotton FAD2-3 coding region accumulate an appreciable amount of linoleic acid (18:2), not normally present in wild-type yeast cells, indicating that the gene encodes a functional FAD2 enzyme. digital.library.unt.edu/ark:/67531/metadc3123/
Molecular Dimensions
This study attempts to calculate the areas of the cross section and diameter of the CH3 group, COOH group, the length of the carbon chain, and the longtiudinal distance between carbon atoms for each of the three acids. It also attempts to develop a method of measuring the effective diameter of molecules of gases. Equations for these terms as given by MacDougall and experiments were performed and the data applied to the equation. digital.library.unt.edu/ark:/67531/metadc29924/
Molecular Dynamics Simulations of the Structures of Europium Containing Silicate and Cerium Containing Aluminophosphate Glasses
Rare earth ion doped glasses find applications in optical and photonic devices such as optical windows, laser, and optical amplifiers, and as model systems for immobilization of nuclear waste. Macroscopic properties of these materials, such as luminescence efficiency and phase stability, depend strongly on the atomic structure of these glasses. In this thesis, I have studied the atomic level structure of rare earth doped silicate and aluminophosphate glasses by using molecular dynamics simulations. Extensive comparisons with experimental diffraction and NMR data were made to validate the structure models. Insights on the local environments of rare earth ions and their clustering behaviors and their dependence on glass compositions have been obtained. In this thesis, MD simulations have been used to investigate the structure of Eu2O3-doped silica and sodium silicate glasses to understand the glass composition effect on the rare earth ions local environment and their clustering behaviors in the glass matrix, for compositions with low rare earth oxide concentration (~1mol%). It was found that Eu–O distances and coordination numbers were different in silica (2.19-2.22 Å and 4.6-4.8) from those in sodium silicate (2.32 Å and 5.8). High tendencies of Eu clustering and short Eu-Eu distances in the range 3.40-3.90 Å were observed in pure silica glasses as compared to those of silicate glasses with much better dispersed Eu3+ ions and lower probability to form clusters. The results show Eu3+ clustering behavior dependence on the system size and suggest for low doping levels, over 12,000 atoms to obtain statistical meaningful results on the local environment and clustering for rigid silica-based glasses. The structures of four cerium aluminophosphate glasses have also been studied using MD simulations for systems of about 13,000 atoms to investigate aluminum and cerium ion environment and their distribution. P5+ and Al3+ local structures were found stable while those of Ce3+ and Ce4+ ions, through their coordination numbers and bond lengths, are glass composition-dependence. Cerium clusters were found in the high cerium glasses.P5+ coordination numbers around cerium revealed the preference of phosphorus ions in the second coordination shell. Total structure factors from MD simulations and experimental diffraction results show a general agreement from comparison for all the cerium aluminophosphate glasses and with compositional changes up to 25 Å-1. Aluminum enters the phosphate glass network mainly as AlO4 and AlO5 polyhedra only connected through corner sharing to PO4 tetrahedra identified by Q11(1 AlOx), Q12(2 AlOx), Q21(1 AlOx), and Q22(2 AlOx) species. digital.library.unt.edu/ark:/67531/metadc149624/
Molecular Modeling Study of Oxidative Degradation of Polyperfluoroethers Catalyzed by Iron Fluoride Surfaces : An Extended Hückel Theory Approach
Extended Hückel methods are known to be a useful tool in understanding surface phenomena. Important quantities about atoms and chemical bonds can be obtained from this computationally simple method, although caution must be exercised in interpreting the results. Application of Extended Hückel calculations to large metal clusters reveals the role of d orbitals in solids. Basic ideas of constructing model compounds have been developed. Several model systems for surface chemisorption processes are constructed in order to understand the surface catalyzed oxidative degradation of polyperfluoroethers. The activation of oxygen molecules can be explained. The Lewis acid character of the iron fluoride surface can be predicted. Based on these results, mechanisms of the degradation processes are discussed. digital.library.unt.edu/ark:/67531/metadc278315/
Molecular Structure Analyses of Asymmetric Hydrocarbon Liquid Compounds in the Gas Phase Using Chirped-pulse Fourier Transform Microwave Spectroscopy: Acyl Chlorides and Perfluorinated Acyl Chlorides
Examinations of the effects of (a.) alkyl carbon chain length and (b.) perfluorination of acyl chlorides; propionyl chloride, butyryl chloride, valeroyl chloride, and perfluorinated acyl chlorides; perfluoropropionyl chloride and perfluorobutyryl chloride, are reported and compared using CP-FTMW spectroscopy. All of these molecules are already published in various journals except for valeroyl chloride. The chapters are organized by molecule alkyl chain length and include some background theory. Conformational stability, internal rotation, helicity, and ionic character of the C-Cl bond via the nuclear electric quadrupole coupling constant (χzz) are analyzed. Results show syn, syn-anti/syn-gauche, and syn-anti-anti/syn-gauche-anti stable conformations. Internal rotation was only seen in propionyl chloride. Helicity was not observed. (χzz) was observed to be inert to alkyl chain length, ~ 60 MHz and ~ 65 MHz for the nonfluorinated and fluorinated acyl chlorides. Partial fluorination and varying functional groups are recommended. digital.library.unt.edu/ark:/67531/metadc103374/
Molecular systematics of Baird's pocket gopher (Geomys breviceps)
Baird's pocket gopher (Geomys breviceps) is found in eastern Texas, eastern Oklahoma, central and western Arkansas, and western Louisiana. The cytochrome-b gene was sequenced and analyzed for 16 pocket gophers from throughout the range of the species. Similar phylogenetic trees were obtained using maximum-parsimony, maximum-likelihood, neighbor-joining, and Bayesian analyses. Two major clades were formed with northern individuals belonging to clade I and southern individuals belonging to clade II. G. b. sagittalis was paraphyletic in relation to G. b. breviceps in all analyses. Based on inconsistencies between the taxonomic classification and systematic relationships within Baird's pocket gopher, a taxonomic restructuring appears warranted. digital.library.unt.edu/ark:/67531/metadc30438/
Moments: a Diary
In my preface I have tried to show what a diary is, why they might be of interest to others, why I think they are valid and should be considered as such. I have defended my diary as being worthy material for a thesis, or myself as worthy of being called a writer. (Traditionally, writing in a diary doesn't qualify one as being a writer, even though you might write millions of pages and spend your entire lives doing it.) Edited selections of my diary make up the body of the thesis. These selections are divided into four main sections which suggested themselves during editing. To summarize the diary as a whole, I would say it's about human relationships. digital.library.unt.edu/ark:/67531/metadc279155/
Monaural and Binaural Speech Reception Thresholds in Normal Children and Those at Risk for Central Auditory Processing Disorders
Children with central auditory processing disorders (CAPD) have a normal pure-tone audiogram, however, they have difficulty understanding speech in the presence of background noise. The present study examined binaural hearing in normal children and those with possible CAPD. Each subject was administered the SCAN or SCAN-A, screening tests for CAPD, to determine whether they were at risk for CAPD. Participants were then subjected to several monaural and binaural speech tasks, in quiet and noise. Spondee words were utilized in each task, under headphone and soundfield conditions. digital.library.unt.edu/ark:/67531/metadc277814/
Money in Four of the Early Novels of Henry James
The purpose of the study at hand is to follow up the suggestions in Winters's observations and Booth's thesis, and to examine both the extent and the nature of money and other financial considerations as these matters appear in the four most important novels of James's early period. digital.library.unt.edu/ark:/67531/metadc130759/
"Money Only Pays for It" and other stories.
This thesis includes a novel of eight short stories and a critical preface. The preface begins with a section placing the stories in their literary historical context in regards to masculinity theory. It goes on to discuss the craft of fictionalizing autobiographical stories. Finally, the preface talks about the choice of a first person narrator. Each of the stories should stand alone, though they follow the narrator's life for a number of years. Todd Welles is the narrator of all the stories, with the exception of a few. In the stories where Todd does not do all of the narration, he is interrupted by the narration of his "friend," Percy 2 Hard Welles, III. digital.library.unt.edu/ark:/67531/metadc4619/
Monitoring and Increasing Goal Related Instruction and Engagement in Groups of Children with Autism
A high rate of instructional engagement is important to maximize progress in early intensive behavioral interventions (EIBI). Teachers responsible for eliciting instructional engagement may need additional support to maintain high rates of engagement. Literature suggests that goal setting and feedback is effective in increasing performance. the purpose of this study was to evaluate whether goal setting and group feedback would increase engagement in instructional activities related to the children’s goals. Results indicate that goal setting and group feedback was successful in increasing engagement in instructional activities. the results are discussed in the context of engagement, staff performance, group contingencies and performance feedback. digital.library.unt.edu/ark:/67531/metadc115148/
Monitoring or moral hazard? Evidence from real activities manipulation by venture-backed companies.
Prior literature suggests two competing theories regarding the role of venture capitalists (VCs) in their portfolio companies. The VC monitoring hypothesis argues that VCs effectively resolve the managerial agency problem through close monitoring and restraining managers' earnings management behavior. The VC moral hazard hypothesis argues that VCs aggravate the private benefits agency problem by exerting influence over managers to artificially inflate exit stock price through earnings management. Using a sample of IPO firms between 1987 and 2002, after controlling for the magnitude of accruals manipulation (AM), I compare the magnitude of real activities manipulation (RM) between venture-backed and non-venture-backed companies. I find that relative to non-venture-backed companies, venture-backed companies show significantly less RM in the first post-IPO fiscal year. The results are robust after controlling for the VC selection endogeneity. The finding supports the VC monitoring hypothesis that VCs restrain managers' RM behavior. Furthermore, I document that venture-backed companies exhibit a significant difference from non-venture-backed companies only in the first post-IPO fiscal year. The difference between the two groups in either the IPO year or the second post-IPO fiscal year is not significant, or at best, is weak. This finding is consistent with the argument that VCs tighten their control during the lockup expiration period when insiders such as managers or founders have strong incentives to inflate earnings. By the end of the second post-IPO fiscal year when VCs exit the portfolio companies, their impact on portfolio companies' RM decreases dramatically which makes the difference between the two groups less significant. In addition, using a sample of venture-backed IPOs from 1987 to 2002, I find that companies backed by high-reputation VCs show significantly less RM than those backed by low-reputation VCs in the first post-IPO fiscal year. The results are robust to alternative VC reputation proxies. This finding is consistent with the argument that high-reputation VCs have more incentives to preserve reputation and better ability to monitor managers than low-reputation VCs. digital.library.unt.edu/ark:/67531/metadc12154/
The Monomythic Pattern in Three Novels by D. H. Lawrence
Sons and Lovers, The Rainbow, and Women in Love present sequentially in fictional version Lawrence's own personal journey into self-discovery in the form of a creation myth of sensual love which repeats the archetypal patterns of some of the great mythologies. It is the purpose of the following pages to show how these three novels reveal the major archetypal patterns of mythology as suggested by Joseph Campbell in his study, The Hero with A Thousand Faces. digital.library.unt.edu/ark:/67531/metadc131004/
Monopolies and Wastes in the Steel Industry
The general problem involved in this study is one of resource utilization. The specific approach of this study shall take the form of an inquiry into the relation between monopoly and waste. digital.library.unt.edu/ark:/67531/metadc83369/
The Monstrance: A Collection of Poems
These poems deconstruct Mary Shelley's monster from a spiritually Chthonian, critically post-structuralist creative stance. But the process here is not simple disruption of the original discourse; this poetry cycle transforms the monster's traditional body, using what pieces are left from reception/vivisection to reconstruct, through gradual accretion, new authority for each new form, each new appendage. digital.library.unt.edu/ark:/67531/metadc277686/
Monte Carlo Calculations of Reflected Intensities for Real Spherical Atmospheres
To calculate the emergent radiation field, a realistic atmospheric model and algorithm must be developed. The radiation field may be characterized by the emergent intensities of scattered light. This is possible only if the algorithm determines these intensities as dependent upon atmospheric and angular parameters. digital.library.unt.edu/ark:/67531/metadc131064/
Monte Carlo simulation and experimental studies of the production of neutron-rich medical isotopes using a particle accelerator.
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The developments of nuclear medicine lead to an increasing demand for the production of radioisotopes with suitable nuclear and chemical properties. Furthermore, from the literature it is evident that the production of radioisotopes using charged-particle accelerators instead of nuclear reactors is gaining increasing popularity. The main advantages of producing medical isotopes with accelerators are carrier free radionuclides of short lived isotopes, improved handling, reduction of the radioactive waste, and lower cost of isotope fabrication. Proton-rich isotopes are the result of nuclear interactions between enriched stable isotopes and energetic protons. An interesting observation is that during the production of proton-rich isotopes, fast and intermediately fast neutrons from nuclear reactions such as (p,xn) are also produced as a by-product in the nuclear reactions. This observation suggests that it is perhaps possible to use these neutrons to activate secondary targets for the production of neutron-rich isotopes. The study of secondary radioisotope production with fast neutrons from (p,xn) reactions using a particle accelerator is the main goal of the research in this thesis. digital.library.unt.edu/ark:/67531/metadc3077/
The Moore-Smith Limit
It is the purpose of this thesis to indicate in more detail how various limits defined in analysis, as well as other concepts not ordinarily defined as limits, may be obtained as special cases of the Moore-Smith limit. digital.library.unt.edu/ark:/67531/metadc107833/
The Moral Judgments of Jane Austen
It is the purpose of this thesis to examine the relevance of Jane Austen's moral and social judgments for the twentieth century, in terms of insight into human nature and human relationships and of a realistic and penetrating treatment of the moral and social problems most vital to moiety in the 1960's. digital.library.unt.edu/ark:/67531/metadc131032/
The Moral Philosophy of James Boswell
It is the purpose of the author to outline briefly some of the intellectual ideas relating to the nature of man, his conception of religion, his social manners and customs, and to reveal, through the "Hypochondriack" essays, that James Boswell was a peculiarly eighteenth-century figure in certain aspects of his moral philosophy. digital.library.unt.edu/ark:/67531/metadc83431/
The Moral Philosophy of Samuel Johnson
The purpose of the author is to give a resume of Johnson's England and by examining The Rambler and Boswell's Life of Johnson, to determine what the Doctor thought concerning the prevailing conditions, social practices, and ideas of his time. digital.library.unt.edu/ark:/67531/metadc83584/
Moral Training for Nature's Egotists: Mentoring Relationships in George Eliot's Fiction
George Eliot's fiction is filled with mentoring relationships which generally consist of a wise male mentor and a foolish, egotistic female mentee. The mentoring narratives relate the conversion of the mentee from narcissism to selfless devotion to the community. By retaining the Christian value of self-abnegation and the Christian tendency to devalue nature, Eliot, nominally a secular humanist who abandoned Christianity, reveals herself still to be a covert Christian. In Chapter 1 I introduce the moral mentoring theme and provide background material. Chapter 2 consists of an examination of Felix Holt, which clearly displays Eliot's crucial dichotomy: the moral is superior to the natural. In Chapter 3 I present a Freudian analysis of Gwendolen Harleth, the mentee most fully developed. In Chapter 4 I examine two early mentees, who differ from later mentees primarily in that they are not egotists and can be treated with sympathy. Chapter 5 covers three gender-modified relationships. These relationships show contrasting views of nature: in the Dinah Morris-Hetty Sorrel narrative, like most of the others, Eliot privileges the transcendence of nature. The other two, Mary Garth-Fred Vincy and Dolly Winthrop-Silas Marner, are exceptions as Eliot portrays in them a Wordsworthian reconciliation with nature. In Chapter 6 I focus on Maggie Tulliver, a mentee with three failed mentors and two antimentors. Maggie chooses regression over growth as symbolized by her drowning death in her brother's arms. In Chapter 7 I examine Middlemarch, whose lack of a successful standard mentoring relationship contributes to its dark vision. Chapter 8 contains a reading of Romola which interprets Romola, the only mentee whose story takes place outside nineteenth-century England, as a feminist fantasy for Eliot. Chapter 9 concludes the discussion, focusing primarily on the question why the mentoring theme was so compelling for George Eliot. In the Appendix I examine the relationships in Eliot's life in which she herself was a mentee or a mentor. digital.library.unt.edu/ark:/67531/metadc2868/
Morale in the Western Confederacy, 1864-1865: Home Front and Battlefield
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This dissertation is a study of morale in the western Confederacy from early 1864 until the Civil War's end in spring 1865. It examines when and why Confederate morale, military and civilian, changed in three important western states, Mississippi, Alabama, and Tennessee. Focusing on that time frame allows a thorough examination of the sources, increases the opportunity to produce representative results, and permits an assessment of the lingering question of when and why most Confederates recognized, or admitted, defeat. Most western Confederate men and women struggled for their ultimate goal of southern independence until Federal armies crushed those aspirations on the battlefield. Until the destruction of the Army of Tennessee at Franklin and Nashville, most western Confederates still hoped for victory and believed it at least possible. Until the end they drew inspiration from battlefield developments, but also from their families, communities, comrades in arms, the sacrifices already endured, simple hatred for northerners, and frequently from anxiety for what a Federal victory might mean to their lives. Wartime diaries and letters of western Confederates serve as the principal sources. The dissertation relies on what those men and women wrote about during the war - military, political, social, or otherwise - and evaluates morale throughout the period in question by following primarily a chronological approach that allows the reader to glimpse the story as it developed. digital.library.unt.edu/ark:/67531/metadc5231/
Morality and Mortality: the Role of Values in the Adoption of Laws Governing the Involuntary Removal of Life Sustaining Medical Treatment in Us States
Disputes between patients and providers regarding life-sustaining medical treatment (LSMT) are universal across all U.S. states, yet policies regarding these disputes differ significantly. This dissertation determines that all 50 states have advance directive laws that protect a patient’s right to refuse LSMT even when a healthcare provider objects, yet only some states have policies that protect the patient’s right to choose to continue LSMT when a healthcare provider objects (a dispute known as medical futility). Some states have pro-patient laws that protect the patient’s right to make the final decision, while other states have enacted pro-provider medical futility policies that explicitly grant the provider authority to remove LSMT against the patient’s wishes. Finally, in one state, the law delegates the final decision to a third-party: institutional healthcare ethics committees. This dissertation studies the innovation and adoption of these 17 state medical futility policies, examining the theory that values determine both whether the state adopts a medical futility policy as well as what type of medical futility policy a state will adopt- as the policy actors that represent these values: policy entrepreneurs and interest groups. A comparative case study of successful third-party policy adoption in Texas contrasted against a failed effort in Idaho could not affirm the necessity of policy entrepreneurs for policy adoption but did affirm the necessity of interest group consensus and the role of values. Furthermore, quantitative analysis failed to offer statistically-significant evidence of value indicators, but did suggest that government ideology and political party affiliation may potentially become indicators of the type of medical futility policy that states choose to adopt. digital.library.unt.edu/ark:/67531/metadc149554/