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Tohoku University徳山豪課

Exploring the Association Between Patient Waiting Time, No-Shows and Overbooking Strategy to Improve Efficiency in Health Care

Many primary care clinics are using overbooking as a strategy to mitigate the negative impacts on operations and performance caused by patient nonattendance of appointments, also known as “no-shows”. However, overbooking tends to increase patient waiting time and worker overtime. It is also acknowledged that patient waiting time is associated with no-show behavior, yet there is a lack of observational study to quantify the relationship. The overall goal of this research is to explore the relationships between patient waiting time, no-show behavior and overbooking strategy in terms of clinic performance. Arena® simulation software is used to create a discrete-event simulation model that represents daily processes of a standard primary care clinic. The model is used to test the three variables by varying (1) the amount increase in no-show probability by tolerance group, (2) waiting time tolerance threshold, and (3) overbooking strategy. We observe from the results that the three features (waiting time, no-show behavior and overbooking strategy) are interrelated because higher no-show probability leads to higher number of no-shows, which suggests overbooking more patients, and eventually leads to longer waiting time, resulting in an increase in the patient’s no show probability. However, as limited by the size of the clinic case, we were not able to see a clear cut-off of average waiting tolerance for making overbooking decisions that are not only based on the prediction of patient no-shows, but also consider the impact on patient waiting time and its association with no-show behavior. Nevertheless, by having the waiting time as one of the constraint variables, we were able to see the trade-off of choosing a certain overbooking decision and its impact on no-shows. To fully understand the impact of the relationship between the three variables, we recommend that more observational studies should be conducted as pertaining to the desired clinic environment

The Disciplinary Effect of Subordinated Debt on Bank Risk Taking

x, 99 p.Using data for publicly listed commercial banks and bank holding companies around the world, I investigate the market discipline effect of subordinated debt on banking firm risk taking in the period 2002-2008. In addition, I examine whether this effect depends on national bank regulations and legal and institutional conditions. I provide evidence that subordinated debt has a mitigating effect on banking firm risk taking. Further, the results suggest a threshold level of national bank regulations and economic development above which subordinated debt mitigates risk taking. Overall, the evidence supports the efficacy of proposals calling for increased use of subordinated debt in banking firms.Committee in charge: Wayne Mikkelson, Chairperson; Ekkehart Boehmer, Member; Diane Del Guercio, Member; Wesley Wilson, Outside Membe

Revisiting the Role of Similarity and Dissimilarity in Best Counter Argument Retrieval

This paper studies the task of best counter-argument retrieval given an input argument. Following the definition that the best counter-argument addresses the same aspects as the input argument while having the opposite stance, we aim to develop an efficient and effective model for scoring counter-arguments based on similarity and dissimilarity metrics. We first conduct an experimental study on the effectiveness of available scoring methods, including traditional Learning-To-Rank (LTR) and recent neural scoring models. We then propose Bipolar-encoder, a novel BERT-based model to learn an optimal representation for simultaneous similarity and dissimilarity. Experimental results show that our proposed method can achieve the accuracy@1 of 49.04\%, which significantly outperforms other baselines by a large margin. When combined with an appropriate caching technique, Bipolar-encoder is comparably efficient at prediction time

Chemical and biological properties of a wall-enzyme activating factor from plants

Xyloglucan endotransglucosylase activity (XET), one of the two main activities of wall xyloglucan endotransglucosylase/hydrolase proteins (XTHs), is of interest because it is responsible for cutting and re-joining xyloglucan of the hemicellulose-cellulose microfibril network in the plant cell wall. XET activity causes transient matrix cleavage without hydrolysis, thus providing a molecular mechanism for controlled, turgor-driven wall expansion. XET activity can be involved in both wall-loosening, thus facilitating cell expansion, and wall-tightening, thus suppressing cell expansion depending on the molecular size, location and age of the participating xyloglucan chains. I have studied the existence of an ‘XET activating factor’ (XAF) in the cold-water-extractable polymers of cauliflower florets. Remaining water-soluble on boiling but losing activity upon proteinase K- and trypsin-digestions implied a heavily glycosylated glycoprotein. XAF was extracted from a wide range of plants and organs. XAF solubilised Arabidopsis cell-wall XTHs, increasing their XET activity on soluble xyloglucan up to 120-fold, tested by a novel method developed in my project. XAF had effects similar to those of 15 mM Ca2+ and 100 mM Na+ in this respect, although it was only weakly ionic. Interestingly, XAF had the unique ability to solubilise XET activity but no other tested wall enzymes from Arabidopsis cell walls, suggesting a specific interaction of XAF to XTH proteins. XAF was successfully purified by the use of several methods, developed in this project. These included cation-exchange column chromatography followed by anion-exchange column chromatography, resulting in two main XAF-activity fractions; or a native- PAGE electro-elution, resulting in three main fractions. Purified XAF contained a major amount of glucose, arabinose, galactose and uronic acid residues. Both boiled cauliflower preparation (BCP) and partially purified XAF were positive with AGP antibodies but the purification of AGP from BCP by the use of Yariv reagent did not enrich XAF activity. Mass-spectrometry analyses of the purified XAF fractions showed some candidates for XAF, including fasciclin-like arabinogalactan-protein 7 (FLA7), stress-responsive protein (LTI65, LTI140) and early nodulin-like protein 14 (ENODL14). Homozygous Arabidopsis mutants (confirmed by genotyping) defective in these genes were used to determine XAF as well as its biological role on plant cell growth. Although there was no phenotype observed, several organs of the mutant plants had significant increases or decreases in XAF activity compared to that of wild type plants. This is the first work that suggests a role of fla7, enodl14 and lti65 in the solubilisation, and thus activation, of Arabidopsis XET