Essays on anticompetitive effects of vertical contracts

The first half of this thesis focuses on the effect of conditional rebates by an incumbent when the firm’s product is a must stock for the buyer. It is inspired by the Intel case. The first essay analyses the baseline model and shows that although the incumbent can exclude the entrant by conditional rebate, the incumbent does not use the rebate to exclude the entrant, because just selling the must stock units with a high price is more profitable. Moreover, the model shows the limitation of the model in the sense that the incumbent has an ability to set incredibly high price to capture all the surplus of the market. Developing the main insight of the baseline model in the first essay, the second essay analyses four extended models to analyse the anticompetitive effects of conditional rebate and other pricing behaviours. The first extended model considers the case where the incumbent’s good is not literally ‘must stock’, but just has superiority over the competitors’ products. The results suggest that we can overestimate the exclusionary effect of conditional rebates when we erroneously assume a quite strong must stock property. The second, third and fourth extended models show that the incumbent can have an incentive to exclude a more efficient competitor in the following situations; 1) there is uncertainty about the must stock proportion, 2) there is uncertainty about demand size or 3) the must stock property is vulnerable in the sense that it becomes weaker if entry happens. The second half of this thesis develops a framework to analyse the competition through platforms that help consumers to get awareness of the sellers. It is motivated by the hotel booking platform cases. An informative advertising model is adapted to model platform investment. The third essay analyses the case where there are a monopoly platform and a monopoly seller and the effect of a narrow price parity clause on competition. The result shows that the introduction of the price parity clause increases the platform’s investment, which has a positive effect on the consumer surplus through giving more opportunity for consumers to become aware of the product. On the other hand, it also has a negative effect on consumer surplus by raising the direct sales price. In some situations, the net effect on consumer welfare can be negative. The fourth essay considers the case where there are duopoly platforms and duopoly sellers and analyses the effect of wide price parity clauses on competition. The results show that wide price parity clauses have a more straightforward effect on competition in the sense that the clauses make it possible for the platforms to avoid competition through undercutting commissions and so set their commissions at the collusive level. The analysis in this chapter shows that without wide price parity clauses the platforms try to undercut each other’s commissions, but the clauses eliminate the possibility of undercutting by the other platform. The result also shows that the introduction of the price parity clause increases the platform’s investment

Probe walking : development of novel probes for DNA fingerprinting

Thesis--University of Tsukuba, D.M.S.(A), no. 786, 1990. 3. 23Offprint. Originally published in: Human genetics, v. 83, pp. 223-226, 1989Joint authors: Shogo Misawa and Shintaroh UedaIncludes supplementary treatise

A Train-the-Trainers (TtT) Program for Engineers for Hosting Multiparty International Clinical Teleconferences

Background: International clinical teleconferencing connecting hospitals contributes to the standardisation of medical care. Introduction: The perception that participating in international teleconferences is easy while hosting and coordinating them is difficult has limited the expansion of these kinds of programmes. We evaluated the effectiveness of a Train-the-Trainer (TtT) programme on hosting international multiparty teleconferences targeted at hospital engineers. Methods: From 2015 to 2017, 20 engineers and physicians from 17 institutions in 10 countries participated in Kyushu University Hospital’s TtT programme. Hands-on training and hosting a Training Report Conference (TRC) were conducted. The impact of the programme was assessed using questionnaires about the participants’ confidence, perception of barriers, and teleconference activity before and one year after the training period. Results: The mean training period was 16.7 days (median, 19 days). Twelve TRCs were hosted by trainees connecting 56 institutions in 11 countries. All participants gave positive evaluations of the overall programme, 19 (95%) "very good" and 1 (5%) "good", and the trainers 9 (90%) "very good" and 1 (10%) "good"). Following the TtT programme, the mean number of trainee-hosted events increased significantly (0.8 to 1.3, p<0.001), and more respondents (12/17, 71%) reported barriers to hosting a programme than participating in one (5/17, 29%, p<0.001). Trainee confidence in both hosting and participating in international teleconferences was significantly higher after TtT. Conclusion: There are more barriers to hosting than participating in international clinical teleconferences. This TtT programmes for engineers could contribute to more active hosting engagement

Event style preferences in medical education and research meetings in Japan

Purpose: With the spread of COVID-19, medical education and research events have either been cancelled or shifted to online or hybrid mode. However, there are no accurate records containing the exact number of these events in new modes. This study explores trends in event modes of medical education and research in Japan using registered event data from a web service. Methods: We collected event data from January 2019 to December 2021. Text mining was used to extract and classify data into categories such as on-site and online events. Then, the annual and monthly numbers of categories were counted. Results: The total number of events in March 2020 was drastically reduced, but it recovered in November 2021 to a level equivalent to that of the peak month in 2019. The majority of the events were online by December 2020, increasing in number from March 2020. Hybrid events that integrate on-site and online modes later outnumbered online events and accounted for approximately 20% of the total in June, October, and November 2021. Conclusions: The online and hybrid modes ensured the continuation of medical education and research events during the pandemic. Though online events may reduce after COVID-19, the hybrid mode could become a popular mode that offers diversity

La5Ti2Cu1-xAgxS5O7 photocathodes operating at positive potentials during photoelectrochemical hydrogen evolution under irradiation of up to 710 nm

A photoelectrochemical (PEC) cell based on a series-connected photocathode and photoanode made of particulate semiconductors is a potentially scalable and inexpensive device for renewable solar hydrogen production via PEC water splitting without any external power supply. The realisation of such PEC devices hinges on the development of photoelectrodes that operate at a small applied voltage. In this study, solid solutions of La5Ti2CuS5O7 (LTC) and La5Ti2AgS5O7 (LTA) were synthesised, and their physical, optical, and PEC properties in the water splitting reaction were discussed. LTC and LTA formed a La5Ti2Cu1-xAgxS5O7 solid solution (LTC(1-x)A(x)) over the whole compositional range. The indirect bandgap energy of LTC(1-x)A(x) changed nonlinearly with respect to composition, attaining its minimum value (ca. 1.8 eV) at a composition of x approximate to 0.16. Photoelectrodes of Al-doped LTC(1-x)A(x) solid solution powder fabricated using the particle transfer method exhibited a photocathodic response regardless of the Ag content. 1% Al-LTC(0.9)A(0.1) photocathodes exhibited the best PEC properties in the hydrogen evolution reaction and yielded a hypothetical half-cell solar-to-hydrogen energy conversion efficiency of 0.25% at +0.6 V vs. RHE, three times higher than the previously reported 1% Sc-LTC. In addition, 1% Al-LTC(0.9)A(0.1) photocathodes were fairly stable at + 0.7 V vs. RHE without any protective modifications. Owing to the positive operational electrode potential of 1% Al-LTC(0.9)A(0.1), unassisted PEC water splitting was accomplished using series-connected photoelectrodes made of 1% Al-LTC(0.9)A(0.1) and BaTaO2N, particulate semiconductors with absorption edge wavelengths of 710 and 660 nm, respectively, at a Faradaic efficiency of unity and a solar-to-hydrogen energy conversion efficiency of approximately 0.1%.ArticleEnergy & Environmental Science.8(11):3354-3362(2015)journal articl

Remote Medical Education in Indonesia: Analysis of 10 Years of Activities

Introduction: With ongoing development of technology, and especially amid the current COVID-19 pandemic, there is rapidly increasing need for remote communications, including in the field of medical education. This study aimed to evaluate our telemedicine activities between Japan and Indonesia. Methods: We retrospectively analysed the data acquired for the period 2010–2019 inclusive, looking at number of programmes, content, participating sites, and videoconferencing systems. We also digitally sent questionnaires to attendees to request their evaluation of image quality and programmes. Results: There were a total 135 programmes, with 29 participating institutions in Indonesia. The number of programmes increased rapidly in 2017, following a rapid increase of participating sites in 2016. Programmes included endoscopy (50 programmes, 37%), neurology (25, 19%), and dentistry (12, 9%). Between 5 and 10 sites connected with 81 programmes (60% of all), and more than 10 sites with 33 (24%). The most commonly used videoconferencing system was Vidyo (108, 80%), followed by Zoom (15, 11%). Participating institutions were located among 19 cities on the five major islands. Image quality received a favourable evaluation from 98% (504/516) of questionnaire respondents, with 100% (400/400) holding a favourable view of the programmes. Conclusion: Remote medical education expanded in Indonesia in the 10 years under review. This expansion is expected to continue to foster more specialists and it is anticipated to improve medical care nationwide

Cardiac magnetic resonance imaging-based myocardial strain study for evaluation of cardiotoxicity in breast cancer patients treated with trastuzumab: A pilot study to evaluate the feasibility of the method

Background: Trastuzumab, used to treat breast cancer overexpressing human epidermal growth factor receptor 2, may be cardiotoxic. Cardiac magnetic resonance (CMR) imaging with myocardial strain studies has been used to evaluate subclinical biventricular myocardial changes, however, its clinical utility during chemotherapy has not been evaluated. Methods: The clinical outcomes, CMR and cardiac biomarkers of 9 women aged 62.3 ± 12.6 years with early or locally advanced breast cancer were evaluated at baseline, and at 3, 6 and 12 months after the initiation of trastuzumab. Results: None of the patients developed heart failure or elevated serum cardiac biomarkers. Global left ventricular (LV) peak systolic longitudinal and circumferential strains were significantly decreased at 6 months (longitudinal strains, –21.1 ± 1.7% [baseline] vs. –19.5 ± 1.0% [6 months], p = 0.039, and circumferential strains, –23.4 ± 1.8% [baseline] vs. –21.6 ± 2.5% [6 months], p = 0.036). These changes were analogous to those observed in the LV ejection fraction. Right ventricular (RV) free wall peak systolic circumferential strains were decreased at 6 months (–20.9% ± 2.4% [baseline] vs. –19.1% ± 2.3% [6 months], p = 0.049), whereas RV longitudinal strains and ejection fraction remained unchanged. The LV longitudinal strain was the most reproducible of the 4 peak strain parameters. Conclusions: The LV longitudinal and circumferential strains measured by CMR decreased during trastuzumab therapy, although their predictive value for later heart failure or association with RV parameters was not determined. These techniques may be a useful means of diagnosing and monitoring trastuzumab-related cardiotoxicity

Massively parallel single-cell genomics of microbiomes in rice paddies

世界初のイネ根圏微生物叢の網羅的1細胞ゲノム解析に成功 --コメ生産現場が抱える問題のデータベース化に向けて--. 京都大学プレスリリース. 2022-11-09.Plant growth-promoting microbes (PGPMs) have attracted increasing attention because they may be useful in increasing crop yield in a low-input and sustainable manner to ensure food security. Previous studies have attempted to understand the principles underlying the rhizosphere ecology and interactions between plants and PGPMs using ribosomal RNA sequencing, metagenomic sequencing, and genome-resolved metagenomics; however, these approaches do not provide comprehensive genomic information for individual species and do not facilitate detailed analyses of plant–microbe interactions. In the present study, we developed a pipeline to analyze the genomic diversity of the rice rhizosphere microbiome at single-cell resolution. We isolated microbial cells from paddy soil and determined their genomic sequences by using massively parallel whole-genome amplification in microfluidic-generated gel capsules. We successfully obtained 3, 237 single-amplified genomes in a single experiment, and these genomic sequences provided insights into microbial functions in the paddy ecosystem. Our approach offers a promising platform for gaining novel insights into the roles of microbes in the rice rhizomicrobiome and to develop microbial technologies for improved and sustainable rice production

Liquid Biopsy Targeting Monocarboxylate Transporter 1 on the Surface Membrane of Tumor-Derived Extracellular Vesicles from Synovial Sarcoma

Simple Summary Synovial sarcoma (SS) is associated with a high risk of recurrence and poor prognosis, and no biomarker useful in monitoring tumor burden exists. We identified monocarboxylate transporter 1 (MCT1) expressed in extracellular vesicles (EVs) derived from synovial sarcoma as a potential such marker. Circulating levels of MCT1(+)CD9(+) EVs were significantly correlated with tumor volume in a SS mouse model. Serum levels of MCT1(+)CD9(+) EVs reflected tumor burden and treatment response in SS patients. Patients with MCT1 expression on the plasma membrane have significantly worse overall survival than those with nuclear expression. Silencing of MCT1 reduced the malignant phenotype including cellular viability, migration, and invasion of SS cells. MCT1 may thus be a promising novel target for liquid biopsies and a novel therapeutic target. The lack of noninvasive biomarkers that can be used for tumor monitoring is a major problem for soft-tissue sarcomas. Here we describe a sensitive analytical technique for tumor monitoring by detecting circulating extracellular vesicles (EVs) of patients with synovial sarcoma (SS). The proteomic analysis of purified EVs from SYO-1, HS-SY-II, and YaFuSS identified 199 common proteins. DAVID GO analysis identified monocarboxylate transporter 1 (MCT1) as a surface marker of SS-derived EVs, which was also highly expressed in SS patient-derived EVs compared with healthy individuals. MCT1(+)CD9(+) EVs were also detected from SS-bearing mice and their expression levels were significantly correlated with tumor volume (p = 0.003). Furthermore, serum levels of MCT1(+)CD9(+) EVs reflected tumor burden in SS patients. Immunohistochemistry revealed that MCT1 was positive in 96.7% of SS specimens and its expression on the cytoplasm/plasma membrane was significantly associated with worse overall survival (p = 0.002). Silencing of MCT1 reduced the cellular viability, and migration and invasion capability of SS cells. This work describes a new liquid biopsy technique to sensitively monitor SS using circulating MCT1(+)CD9(+) EVs and indicates the therapeutic potential of MCT1 in SS

A Novel RNA Synthesis Inhibitor, STK160830, Has Negligible DNA-Intercalating Activity for Triggering A p53 Response, and Can Inhibit p53-Dependent Apoptosis

RNA synthesis inhibitors and protein synthesis inhibitors are useful for investigating whether biological events with unknown mechanisms require transcription or translation; however, the dependence of RNA synthesis has been difficult to verify because many RNA synthesis inhibitors cause adverse events that trigger a p53 response. In this study, we screened a library containing 9600 core compounds and obtained STK160830 that shows anti-apoptotic effects in irradiated wild-type-p53-bearing human T-cell leukemia MOLT-4 cells and murine thymocytes. In many of the p53-impaired cells and p53-knockdown cells tested, STK160830 did not show a remarkable anti-apoptotic effect, suggesting that the anti-apoptotic activity is p53-dependent. In the expression analysis of p53, p53-target gene products, and reference proteins by immunoblotting, STK160830 down-regulated the expression of many of the proteins examined, and the downregulation correlated strongly with its inhibitory effect on cell death. mRNA expression analyses by qPCR and nascent RNA capture kit revealed that STK160830 showed a decreased mRNA expression, which was similar to that induced by the RNA synthesis inhibitor actinomycin D but differed to some extent. Furthermore, unlike other RNA synthesis inhibitors such as actinomycin D, p53 accumulation by STK160830 alone was negligible, and a DNA melting-curve analysis showed very weak DNA-intercalating activity, indicating that STK160830 is a useful inhibitor for RNA synthesis without triggering p53-mediated damage responses