Flavonoids are plant secondary metabolites that have significant biochemical and physiological roles. Biosynthesis of these compounds involves several modifications, most predominantly glucosylation, which is catalyzed by glucosyltransferases (GTs). A signature amino acid sequence, the PSPG box, is used to identify putative clones and has been shown to be involved in UDP-glucose binding. Site-directed mutagenesis is used to answer questions regarding the structure and function of this family of enzymes, particularly what allows some GTs to be more selective towards some substrates than others. The grapefruit (Citrus paradisi) flavonol-3-O-glucosyltransferase (CpF3GT) is specific for flavonol substrates and will not glucosylate anthocyanidins. Comparison of the CpF3GT sequence with that of Vitis vinifera GT, which glucosylates both flavonols and anthocyanidins, provided the basis for the amino acid substitution of proline 145, alanine 374, and alanine 375 in CpF3GT to threonine, aspartate, and glycine, respectively, to test the affect on GT’s affinity for flavonoid substrates.

Intentional forgetting is a phenomenon that has been studied by memory researchers since 1968 (Bjork, LaBerge, & Legrand, 1968), however a formal model to explain directed forgetting has not yet been developed. In this paper, I will review the literature on directed forgetting and discuss the results six experiments used assess directed forgetting in highly controlled manner. The striking findings are a.) that directed forgetting phenomena are observed for both free recall and recognition memory when the list method is utilized, b.) that almost the entire effect in free recall is the result of the ability to initially recall the item from the first serial position, and c.) that the costs and benefits are separately affected by an increase in the retention interval. After extensive model analyses, no simple rehearsal or context based model was identified that can handle the full data set. Here I describe a Retrieving Effectively from Memory model (REM; Shiffrin & Steyvers, 1997) that does account for the full range of findings by blurring the traditional distinctions between these classical approached to directed forgetting phenomena.

Sepsis is the leading cause of death among hospitalized patients in the United States, is responsible for more than 200,000 deaths annually, and has as high as a 50% mortality rate. Sepsis requires prompt identification so that early goal-directed therapy can be instituted to lead to better outcomes. The purpose of this quality improvement project was to determine if implementing an evidence-based identification and intervention program, Project Code Sepsis, in the emergency department can increase the number of patients who receive antibiotics within the first hour of triage and decrease the length of hospital stay. Specifically, the primary project goals were: (a) to administer initial antibiotic treatments within 1 hour of triage to more than 75% of patients, and (b) to reduce length of hospital stay to an average of less than 7 days. The project was developed from the Donabedian Healthcare Quality Triad and guided by the Six Sigma DMAIC method. A total of 306 patients were included in this project conducted from May to October 2015. The sepsis-screening tool was fully implemented during August when more than 75% of patients received their initial antibiotic within one hour of triage time. However, this accomplishment was not sustained during the next two months. Interestingly, August was also the month with the highest length of hospital stay (7.49 days) among sepsis patients. This quality improvement project did not show that the provision of antibiotic therapy within the first hour of triage time decreases the length of hospital stay among sepsis patients. Multiple factors including administration of intravenous fluids and vasopressors for hypotension, nurse and physician experiences, patient acuity, and local sepsis bacteria profile should be considered together in future studies and quality improvement projects.

Chemistry is on the verge of a new era where the attention of chemists has shifted from covalent bonds to noncovalent interactions and their use as a predictable way to guide reactions pathways and product formation. Nature synthesizes elegant molecules under mild conditions and the designed syntheses have been demonstrated to be largely dependent on recognition, self-assembly and templating effects between molecular building blocks. Although covalent synthesis in fluidic medium via supramolecular control has been achieved with limited success, organic solid state has been of particular interest since it avoids solvent effects, and is able to provide unique materials with remarkable stereoselectivity under environment-friendly conditions. Although reactions in solids have resulted in a number of remarkable discoveries in chemistry and materials science, solid-state synthesis is generally not considered as a mainstream synthetic medium and solid-state reactions are seldom appreciated as an efficient way to access molecular targets. Owing to the limited number of solid-state reactions and the uncontrollable nature of crystal packing, solid state has not been utilized readily as a primary synthetic medium. In this context, reactions conducted in multicomponent molecular assemblies or co-crystals have been attracting much attraction in recent years as a general way of controlling the reactivity of molecules in solid state. A molecular component in the multicomponent molecular solid, acting as a linear template, has been shown to preorganize molecules in a modular way via intermolecular interactions and engineer their physical and/or chemical properties. The [2+2]photodimerization of olefins is a successful demonstration how templated solid state synthesis can efficiently synthesize complex targets that are synthetically challenging via conventional routes. In this dissertation, the generality and synthetic applicability of the templated synthetic approach in solid state will be described. How supramolecular interactions in molecular co-crystals precisely guide covalent bond formation in order to construct complex molecular targets will be demonstrated. Finally, co-crystallization will be shown as a general way to control optical properties in crystals.

China's open-door policy to the West has created a great demand for Chinese speakers of English. But the existing formal language institutions are far from enough to meet such a great need. Consequently, large numbers of people will have to learn English by themselves, self-directed to different extents, depending on the facilities available to them. There are also large numbers of potential selfdirected learners who do not yet know where to start and how to tackle the task. Self-directed learning, either of English or of other subjects, has always played an important role in China as an alternative form of education. There have been many successful self-directed learners who have made remarkable contributions to the country in different fields. However, self-directed learning of English on a large scale is still a relatively new phenomenon. Some proper guidance and the learners' awareness of the likely difficult areas will make the learning both more effective and more efficient. This study will attempt to examine the gradual change from teacher-centred teaching and learning to learner-centred teaching and learning and the development of self-directed learning. Then the study will try to provide information on some of the self-directed learning programmes of interest to Chinese learners. Afterwards, the study will examine the basic needs and characteristics of Chinese self-directed learners. The greater part of this study will be devoted to the likely areas of difficulty of self-directed learners in China and some possible ways to solve them. The last part will deal with study skills in self-directed learning and use of resources available.

Among the genetic mutations involved in carcinogenesis, TP53 mutation is a frequent event in many types of cancer. P53 is a transcription factor that regulates activities such as cell cycle arrest, apoptosis, DNA repair and angiogenesis. The majority of TP53 mutations are missense mutations that accumulate in cancer and are often retained in distant metastases. The effects of the mutant p53 proteins include loss of function, dominant-negative effects over wild-type (WT) p53 and possible acquisition of new properties (gain-of-function). However, some of these properties may differ from one mutant p53 protein to another. These differences could have implications for the in vivo behaviour of tumours carrying particular mutations and hence patient prognosis. The aim of this project was to investigate the phenotypic variation between cells transformed with different p53 mutants. This was achieved by constructing a range of TP53 mutants (R175H, G245S, R248W, R248Q, R273H, R282W) using PCR-based mega-primer site directed mutagenesis. These mutants were cloned into a mammalian bi-cistronic expression vector (designed for the co-expression of WT and mutant TP53 from a single plasmid) to allow transient expression in NCI-H358 cells (p53 null). Regard to the method for PCR site directed mutagenesis, the main technical difficulty with conventional methods was the insufficiency of the mutant TP53 product yield (75%). This thesis has modified these methods by carrying over the start template to a second round of PCR and increasing the MgCl2 concentration. This modified PCR-based site directed mutagenesis method has demonstrated an increased mutant TP53 product yield (100%). The tetracycline expression system is the most widely used for conditional inducible systems in mammalian cells, although high background expression has been a main problem. The ecdysone inducible system potentially allows for the study of the conditional expression of the exogenous reporter gene even though it may be cell lethal or alter the phenotype during the selection of transfectants. This system relies on two independent transfections of two plasmids namely pVgRXR and pIND. However, disruption of the regulatory element within the plasmid during stable integration can result in silence or high background expression of the exogenous reporter gene. A previous study reported a transient luciferase reporter assay to screen the cell line stably transfected with pVgRXR plasmid. However, there is no suitable method to screen the subsequent pIND transfection. This thesis has demonstrated a real time RT-PCR strategy to screen for the background expression problem associated with the ecdysone expression system. However, due to the project’s time limitations, a transient expression system rather than a stable expression system was used. The metastasis related cellular activity of WT/mutant TP53 transfected NCI-H358 cells was examined using a range of in vitro functional assays including a proliferation assay, a p21 promoter binding activity assay, a colony formation assay, and a migration assay. To extend the study, this thesis also employed real-time RT-PCR to examine the mRNA expression level of three metastatic related genes, VEGF, HER-2, and E-cadherin, in the WT/mutant TP53 transfected NCI-H358 cells. The results showed that different WT/mutant TP53 transfected cell linse could contribute to markedly different cellular activity. Among these mutants, R175H produced the highest cellular proliferation activity, the strongest dominant-negative activity over the WT on the p21 promoter binding activity and apoptosis activity, and the greatest effect on cellular migration. Furthermore, the real-time PCR results showed that the WT p53 inhibited transcription of key metastasis-related genes such as VEGF and HER-2. Considered with recent literature, this led me to postulate a feedback amplification cycle involving defective p53 and HER-2 mRNA expression. In conclusion, cancer cells with the R175H mutant could contribute to aggressive tumours. This conclusion, based on the in vitro data, is consistent with some clinical observations and animal model experiments. In the past few years it has become apparent that epigenetic changes also play a vitally important role in the cancer developmental process. Recent studies have reported the p53 protein can contribute in methylation which is one of the processes involved in epigenetic modification. This thesis employed a very new PCR-based AMP technique to examine the change of the global genome methylation pattern as a result of knocked-out p53 protein. The results showed defective p53 protein expression may associate with the global genome methylation pattern changes. However, it is important to note that antibiotic reagents, which were used for stable transfectant selection, could also contribute to the global genome methylation changes. In conclusion, this thesis has successfully developed two new methods. One allows the generation of a genetic mutant construct using PCR-based site directed mutagenesis while the other screens the tightly regulated ecdysone reporter system. In terms of effect of p53 in in vitro cell activity, this thesis has postulated that the R175H mutation is associated with much more aggressive metastatic cellular activity. Finally, this thesis also reported that loss of p53 expression could also result in changes in the global genome methylation pattern.

Many parallel programming languages allow programmers to describe parallelism by using constructs such as fork/join. When executed, such programs can be modeled as directed graphs, with nodes representing a computation and edges representing the sequence and dependency. However, because it does not coerce regularity in the computation, the general model is not amenable to efficient execution of the resulting program. Therefore, a more restrictive model called Series-Parallel DAG (Directed Acyclic Graph) has been proposed and adopted by several major parallel languages. As reported by the Cilk developers, many parallel computations can be easily expressed in the series-parallel model, and there are provably efficient scheduling algorithms for the SP DAGs. Nevertheless, it remains open how much inherent parallelism will be lost when conforming to the model, because expressing a computation in the series-parallel model may also induce performance losses. We will show that any general DAG can be converted into an SP DAG without violating the original precedence relations; moreover, the conversion can be carried out in essentially linear time and space, and the resulting DAG exhibits little loss in the parallelism. Since the resulting SP DAG can then be executed with high efficiency, it implies that the languages based on SP DAGs are not as restrictive as they were thought to be. / Singapore-MIT Alliance (SMA)

New literacies in reading research demand for the study of comprehension skills using multiple modalities, through a more complex, multi-platform view of reading. Taking into account the robust roll of technology in our daily lives, research suggests that educators need activities to connect students' lack of reading skills with their growing multimodal literacy. During the post-reading phase of a directed reading activity (DRA), students were engaged in digital storytelling, where they created digital videos and slideshows based on information text read during DRA. Previous studies highlighting the use of digital storytelling have been limited to narrative formats and the influence that participation in this activity has on self-esteem and identity. This activity has been widely recommended for improving writing among teachers and in teaching journals, but it has not been empirically studied in the classroom as a comprehension activity. The theoretical framework that supported this study was Vygotsky's Cultural Historical Activity Theory (CHAT). The researcher used the CHAT framework and Burke's Pentad of Analysis (1969) to study the nature of student interactions. Research questions for this study were answered through both quantitative and qualitative methods. The questions being asked by the researcher were: 1.What were the effects of participation in directed reading activity (DRA) modified to include digital storytelling in the post-reading phase of DRA on 6th graders' comprehension of information text? 2. Did the interactions observed during participation in directed reading activity modified to include digital storytelling reflect the principles promoted by Cultural-Historical Activity Theory? Eighty sixth-grade students were randomly assigned to their digital storytelling groups. The subjects participated in whole-class DRA on two information texts, with the treatment group creating digital stories based on the texts. Cloze scores indicated that there was no significant difference in comprehension due to the treatment. However, there was ample evidence to support the claim that participation in digital storytelling instantiates the principles of CHAT. Overall, digital storytelling does show promise as a multimodal instructional activity, and the discussion expands to several implications and recommendations of future research on this instructional activity.

RNA metabolism includes all the processes required for RNA synthesis, maturation, and degradation in living cells. Ribonucleases (RNases) are involved in RNA maturation and degradation, two essential processes in gene expression and regulation in both prokaryotes and eukaryotes. Oligoribonuclease (Orn) has an important role in eliminating small oligonucleotides (nano-RNA), the last step in mRNA degradation. In E. coli, Orn is the only essential exoribonuclease. The enzyme has been shown to form a stable dimer, both in solution and in the crystalline form. Analysis of the three-dimensional structure of Orn allowed us to hypothesize that dimerization is essential for enzyme catalysis. In order to test the hypothesis, I analyzed a number of deletion and point mutants of Orn and determined that tryptophan 143 is essential for dimerization. A W143A mutant is unable to dimerize and has very little activity, similar to that of an active site mutant (D162A). The atomic structure of the W143A mutant, solved at a resolution of 1.9 Å, showed that although the overall three-dimensional fold is similar to that of the wild-type protein, minor differences exist that could account for the monomeric behavior in solution. A flexible Arg174 is repositioned into the cavity created by the missing Trp143. In this new orientation Arg174 protrudes into a hydrophobic pocket in the dimerization interface and is proposed to produce sufficient unfavorable interactions to keep the monomers apart in solution. All these data suggest that dimerization of Orn is essential for its activity. The human homolog of Orn, also known as small fragment nuclease (Sfn), has been shown to degrade short single-stranded RNA, the last step in mRNA decay. In order to determine the mechanism of action of Sfn and its role in the cell, we solved the crystal structure of a truncated form of Sfn at a resolution of 2.6 Å. This mutant form of Sfn lacks the C-terminal 21 amino acids (Sfn-∆C21) yet is as efficient as full length Sfn on model substrates. Interestingly, Sfn is not as active as E. coli Orn in in vitro assays. Analysis of the atomic structure revealed that the active site cleft in Sfn is narrower than the corresponding active site in E. coli. We propose a model for how this narrower cleft may explain the lower in vitro activity. Bacillus subtilis does not have an Orn homolog and until recently, the enzyme responsible for nano-RNA degradation in this organism was unknown. YtqI (also termed nrnA or nanoRNase), a protein unrelated to E. coli Orn, was recently shown to be responsible for the digestion of oligonucleotides in B. subtilis. In order to better understand the mechanism of action of YtqI, I solved its crystal structure at a resolution of 2.0 Å. The nuclease has a RecJ-like fold with two globular domains connected via a flexible linker that forms a central groove. On one side of the groove, the larger N-terminal domain harbors the putative active site, while on the opposite side, the C-terminal domain includes a putative RNA binding domain. The structure of YtqI provides insights into how this enzyme binds and digests oligoribonucleotides. The studies described here provide a better understanding of the mechanism of action for several exoribonucleases that act on nano-RNA oligonucleotides - Oligoribonuclease from E. coli, its close homolog in humans (Small fragment nuclease), as well as a functional homolog in Bacillus (YtqI). This work is relevant to understanding RNA metabolism, which is an essential process for survival of both eukaryotic and prokaryotic organisms.

With the number of people living longer and with more chronic problems, it is important that health educators examine who they are educating as well as the methods and circumstances of the education. The purpose of this study was to identify the relationship between self-directedness and health promotion in the elderly. A convenience sample of 108 elders who use Senior Centers in rural East Tennessee comprised the study group. The sample was asked to complete the Self-Directed Learning Readiness Scale, the Health Promoting Lifestyle Profile II, and a demographic information survey at a regular meeting of a Senior Center. A positive relationship (r=.394; p<.005) was found between self-directedness as a measure of intrinsic motivation with participation in health promoting behaviors. Demographic information was used to describe the sample and was also used to determine if there was a relationship between any of the demographic items and health promotion practices or self-directed learning readiness. Participation in religious/spiritual activities was significant for both self-directed learning readiness and health promotion practices. Pender’s Revised Health Promotion Model and the Personal Responsibility Orientation Model provided an excellent basis for this study. The study confirmed the need for personal motivation in the elderly to accomplish increased participation in health promotion practices. Both self-directed learning readiness and health promoting behaviors were reviewed for consideration of previous research in the area, and theoretical perspectives. The key implication for practice is that health educators need to understand the motivation of their client prior to educating them regarding an aspect of health promotion. Recommendations for research include more qualitative studies. Almost all the studies available at present are quantitative and the reason for participation needs further investigation. Qualitative studies would enhance the information regarding the reasons for participation in health promotion.