Understanding Economic Dynamics Behind Growth-Inequality Relationships

In this paper, a Dynamic General Equilibrium (DGE) model of growth-inequality relationships, with missing credit markets, knowledge spillover and self-employed agents, is calibrated to New Zealand data. The model explains how two distinct policy shocks involving redistribution and immigration imply, subsequently, two completely opposite outcomes. Agents' inability to borrow aggravates a negative macroeconomic effect of heterogeneity on growth. Redistribution mitigates that effect but creates microeconomic disincentives on saving and work-effort. Consequently, immigration shocks that perturb variance of efficiency induce a negative growth-inequality relationship, while redistribution shocks, in New Zealand's case, produce larger fluctuations in incentives than in macro benefits, implying a positive growth-inequality relationship.Heterogeneous agents, externality, income inequality, growth, progressive redistribution.

Bounding the mass of graviton in a dynamic regime with binary pulsars

In Einstein's general relativity, gravity is mediated by a massless spin-2 metric field, and its extension to include a mass for the graviton has profound implication for gravitation and cosmology. In 2002, Finn and Sutton used the gravitational-wave (GW) back-reaction in binary pulsars, and provided the first bound on the mass of graviton. Here we provide an improved analysis using 9 well-timed binary pulsars with a phenomenological treatment. First, individual mass bounds from each pulsar are obtained in the frequentist approach with the help of an ordering principle. The best upper limit on the graviton mass, $m_{g}<3.5\times10^{-20} \, {\rm eV}/c^{2}$ (90% C.L.), comes from the Hulse-Taylor pulsar PSR B1913+16. Then, we combine individual pulsars using the Bayesian theorem, and get $m_{g}<5.2\times10^{-21} \, {\rm eV}/c^{2}$ (90% C.L.) with a uniform prior for $\ln m_g$. This limit improves the Finn-Sutton limit by a factor of more than 10. Though it is not as tight as those from GWs and the Solar System, it provides an independent and complementary bound from a dynamic regime.Comment: 8 pages, 2 figures; accepted by PR

Research on Australian E-Retailers: Srtategic Issues, Success Factors, and Challenges

The emergence of the Internet has revolutionized retailing industry. However, the technology stock slump worldwide last year has made financing much more difficult for many e-tailer. As more well-established traditional retailers roll out their own online divisions and branches, online market, or marketplace, becomes increasingly competitive. How can Australian e-tailers successfully survive in this new competitive environment? This paper attempts to integrate research on Australian e-tailers and empirically explore, using a case study approach, some strategic issues in managing e-tailers. Research so far on Australian e-tailers has shown that Australian e-tailers have used state-of-the-art Internet technology in designing their Web site and have offered a big range of products to their online customers. They also perform reasonably well in customer services. The most difficult challenge facing them is fulfillment because of its geographic isolation and low population density. Australian government is actively involved in tackling those issues concerned by consumers, such as privacy and security, by legislation and promoting \u27best practice model\u27. The findings from a case study of an Australian e-tailer helps us understand several strategic issues in managing pure e-tailers. To survive, e-tailers need to carefully select product offerings, streamline business processes, minimize marketing budget and HR costs, improve fulfillment efficiency, and adopt a long -term growth strateg

간세포암 환자에서 항바이러스 요법이 cccDNA에 직접 영향 없이 HBx를 하향 조절하여 MSL2 레벨을 저하시키는 기전에 대한 연구

학위논문(박사)--서울대학교 대학원 :의과대학 의학과,2019. 8. 서경석.배경 B형 간염바이러스(HBV)의 감염은 세계적인 건강 문제로서 만성 B형 간염은 간세포암의 주요 원인이기도 하다. B형 간염 바이러스의 covalently closed circular DNA (cccDNA) 는 B형 간염 복제에 필요한 주 형으로서 HBV 복제에 직접 참여하지는 않지만, 간세포 핵 내에서 안정 적인 폴을 유지한다. HBV-encoded X protein (HBx)는 종양 발생 기능을 지니고 있는 주요한 oncoprotein으로서 Male Specific Lethal 2 (MSL2)와 같은 E3 ubiquitin ligase에 의하여 특이적으로 조정되어 HBx의 활성을 상 향 조절하는 ubiquitination화 되어 전사과정, 세포 증식 및 종양의 성장을 촉진하는 역할을 한다. 이 연구에서는 종양 및 종양 주변 간 조직에서 cccDNA, MSL2 mRNA 및 HBx mRNA양을 비교하였고 또한 HBx 양성인 환자와 HBx 음성인 환자에서 cccDNA및 MSL2 mRNA양의 차이를 비교 하는 것을 목표로 하였다. 또한 항바이러스 치료요법이 이러한 지표에 미치는 영향을 관찰 하였다. 방법 간 절제 수술을 받은 B형 간염을 동반한 간세포암 환자 50명을 대상 으로 Real-time PCR 분석법을 통해 간 내 cccDNA, MSL2 mRNA 및 HBx mRNA의 발현 양상을 비교 하였다. 결과 본 연구에 총 50명의 환자가 포함되었다 (49명의 HBsAg 양성, 1명은 항바이러스 치료 후 혈청 전환 되였음). 수술 전 31명은 항바이러스 치 료를 받았고 19명은 치료받지 못했다. 간 내 cccDNA양을 비교하여 볼 때 종양 조직에서 종양 주변조직에 비하여 유의하게 높았다 (44.68 ± 65.14 vs. 11.47 ± 23.03; p = 0.001). 이러한 종양 조직과 종양 주변조직 에서의 cccDNA 수준은 특히 HBeAg 양성 군 (90.07 ± 93.94 vs. 10.05 ±10.48; p = 0.008), 수술 후 종양 재발 군 (p = 0.002)과 종양 크기가 3cm 미만인 군 (p = 0.003)에서 현저하게 차이가 있었다. 더욱이 수술 전 간 경변증 환자의 경우 cccDNA와 MSL2 mRNA양은 종양 조직에서 종양 주 변조직에 비하여 유의미하게 높았다 (p < 0.001, p = 0.023). 항바이러스 치료를 받은 환자 종양 조직과 종양 주변조직에서의 HBx mRNA양은 치 료 받지 않는 군에 비하여 유의미하게 낮았다 (p = 0.026, p = 0.035). HBx 양성 그룹의 cccDNA와 MSL2 mRNA 수준은 종양 주변조직에서 보 다 종양 조직에서 유의하게 높았다 (p = 0.026, 0.013). 또한 MSL2 mRNA 수준은 HBx 음성 종양 조직보다 HBx 양성 종양 조직에서 유의 하게 높았다 (p = 0.002). 그러나 HBx 양성 종양 조직과 HBx 음성 종양 조직 사이에는 cccDNA 수준의 차이가 없었다 (p = 0.609). 결론 cccDNA는 HBV 관련 간세포암 조직에서 높게 관찰되며 항바이러스 치료를 통하여 만성 B형간염에 의한 HCC 형성과정에서 HBx의 형성을 억제함으로서 cccDNA와 MSL2의 간세포암 형성 과정에서의 영향을 조 절할 수 있을 것이다.Introduction Hepatitis B virus (HBV) infection is a global health problem and chronic hepatitis B is the leading cause of hepatocellular carcinoma. The covalently closed circular DNA (cccDNA) is an intermediate in the life cycle of HBV virus. HBV-encoded X protein (HBx), a key viral oncoprotein, can be specifically modified by E3 ubiquitin ligase, such as Male Specific Lethal 2 (MSL2), a process called ubiquitination that up-regulates HBx activity to promote transcription, cell proliferation and tumor growth. This study aimed to compare the cccDNA, MSL2 mRNA, and HBx mRNA levels in tumor and peri-tumor tissues, and to compare differences in cccDNA and MSL2 mRNA levels between HBx-positive and HBx-negative patients. Moreover, we clarified the impact of antiviral therapy on these indicators. Methods The levels of intrahepatic cccDNA, MSL2 mRNA and HBx mRNA in 50 patients with HBV-related HCC who had undergone liver surgery were compared. Real-Time PCR assay was performed to quantify these indicators. Results A total of 50 patients were included in this study (49 HBsAg positive and 1 showing seroconversion after antivirus treatment). Before surgery, 31 of them had undergone antiviral treatment and 19 had not. Intrahepatic cccDNA levels ware significantly higher in the tumor tissues than in peri-tumor tissues (44.68 ± 65.14 vs. 11.47 ± 23.03; p = 0.001). The cccDNA level in the tumor and peri-tumor tissues was significantly different, especially in the HBeAg positive group (90.07 ± 93.94 vs. 10.05 ± 10.48; p = 0.008), tumor recurrence group (p = 0.002) and tumor size less than 3cm group (p = 0.003). Moreover, in patients with preoperative cirrhosis, levels of cccDNA and MSL2 mRNA were significantly higher in tumor tissue than in peri-tumor tissue (p < 0.001 and p = 0.023). The levels of HBx mRNA in tumor and peri-tumor tissues were significantly lower in the antiviral treated group than in untreated group (p = 0.026 and p = 0.035). The levels of cccDNA and MSL2 mRNA in the HBx positive group were significantly higher in tumor tissues than in peri-tumor tissues (p = 0.026 and 0.013). Moreover, MSL2 mRNA levels were significantly higher in HBx-positive tumor tissues than in HBx-negative tumor tissues (p = 0.002). However, there was no difference in cccDNA levels between HBx-positive tumor tissues and HBx-negative tumor tissues (p = 0.609). Conclusion cccDNA level was higher in tumor tissue and antiviral therapy can modulate hepatocarcinogenesis by reducing levels of HBx to inhibit the tumorigenic effect of MSL2 and cccDNA.Abstract .......................................................................................................................... i Contents ......................................................................................................................... iii Legends of Table and Figures............................................................................................ iv 1. Introduction ................................................................................................................ 1 2. Methods ..................................................................................................................... 2 3. Results ........................................................................................................................ 5 4. Discussion.................................................................................................................... 7 Reference ........................................................................................................................11 국문 초록.......................................................................................................................... 22 감사의 글.......................................................................................................................... 24Docto

Strategic Implementation of E-Procurement: A Case Study of an Australian Firm

The rapid development of Internet technology has made inter-organisation connectivity much easier and cheaper than ever before, hereby providing an opportunity for companies, both large and small, to realise the true value of the Internet. Despite the huge investment and complexity of implementing eprocurement, there is little empirical research to provide managerial guidelines for developing effective procurement strategies and for successfully implementing e-procurement. This paper attempts to fill this gap by reporting an Australian case study on the adoption of e-procurement. The findings offer detailed, varied and practical strategic insights into organisational redesign, critical factors, and challenges. The implications are also offered