Essays on international trade and economics of conflict

Doctor of PhilosophyDepartment of EconomicsYang-Ming ChangThe first chapter is motivated by the recent territorial disputes, in South China Sea and the Middle East, over external territories rich in natural resources. The objective of the study is to understand why political disputes over external territories sustain or persist despite that the countries engaged in conflict are trading partners. This chapter presents a game theoretical model to analyze the impact of bilateral trade on the economic and political behavior of the two contending countries. The analytical results suggest that greater trade openness (by lowering trade cost) reduces conflict intensity when the contending countries are symmetric in their national endowments. This finding is consistent with the liberal peace hypothesis that trade reduces conflict. For the case where there are differences in national resource endowments, the analysis shows that the overall conflict may increase despite greater trade openness. This chapter has policy implications on the role of bilateral trade and size of an economy for conflict resolution. The second chapter considers trade regionalism and the endogeneity of security policy. Using a sequential-move game, this chapter is the first to characterize the endogeneity of security and trade policies in a three-country framework with two adversaries and a neutral third party. It has been shown that an FTA between two adversaries (i.e., “dancing with the enemy” in trade regionalism) has the strongest pacifying effect, followed by worldwide free trade. Second, the pacifying effect of worldwide free trade is stronger than that of the protectionist regime. Third, relative to all other regimes, an FTA between one of the adversaries and a neutral third party is conflict-aggravating. Furthermore, this chapter compares conflict intensities when instead there is a customs union (CU) and identify differences in implications between CU and FTA for interstate conflicts. The third chapter investigates the scenario of two enemy countries that do not engage in trade. The objective is to analyze what would be their optimal arming allocations for national defense when a politically neutral third party forms a free trade agreement (FTA) with only one of the adversaries (Single FTA), as compared to the case when the third party forms an FTA with each of them (Multiple FTAs). The major finding is that an FTA between a neutral third country and each of the adversary countries (despite that they do not trade) has a pacifying effect since the overall conflict intensity decreases. However, an FTA between the third country and only one of the adversaries is conflict-aggravating as the overall conflict intensity increases

Smart Contract-based Consensus Building for Collaborative Medical Decision-Making

Medical decision-making is moving away from the traditional one-off dyadic encounter between the patient and physician, and transitioning towards a more inclusive, shared decision-making process that also considers the inputs from other stakeholders. This ensures that a patient's decision is not only based on a medical opinion, but also includes other considerations such as impact on family members, legal and financial implications, and experiences of patients in similar situations. However, given the sensitive nature of health data and decisions, there are several challenges associated with safeguarding the privacy, security and consent of all contributors and assuring the integrity of the process. We propose a collaborative medical decision-making platform that uses a consensus building mechanism implemented using Blockchain-based Smart Contracts to address some of the above challenges, thereby giving the participants confidence that both the decision-making process and the outcome(s) can be trusted. We also present a proof-of-concept implementation using the private Ethereum Blockchain to demonstrate practicability

Precision health in behaviour change interventions: A scoping review

Precision health seeks to optimise behavioural interventions by delivering personalised support to those in need, when and where they need it. Conceptualised a decade ago, progress toward this vision of personally relevant and effective population-wide interventions continues to evolve. This scoping review aimed to map the state of precision health behaviour change intervention research. This review included studies from a broader precision health review. Six databases were searched for studies published between January 2010 and June 2020, using the terms ‘precision health’ or its synonyms, and including an intervention targeting modifiable health behaviour(s) that was evaluated experimentally. Thirty-one studies were included, 12 being RCTs (39 %), and 17 with weak study design (55 %). Most interventions targeted physical activity (27/31, 87 %) and/or diet (24/31, 77 %), with 74% (23/31) targeting two to four health behaviours. Interventions were personalised via human interaction in 55 % (17/31) and digitally in 35 % (11/31). Data used for personalising interventions was largely self-reported, by survey or diary (14/31, 45 %), or digitally (14/31, 45 %). Data was mostly behavioural or lifestyle (20/31, 65 %), and physiologic, biochemical or clinical (15/31, 48 %), with no studies utilising genetic/genomic data. This review demonstrated that precision health behaviour change interventions remain dependent on human-led, low-tech personalisation, and have not fully considered the interaction between behaviour and the social and environmental contexts of individuals. Further research is needed to understand the relationship between personalisation and intervention effectiveness, working toward the development of sophisticated and scalable behaviour change interventions that have tangible public health impact

A lipidomic screen of hyperglycemia-treated HRECs links 12/15-Lipoxygenase to microvascular dysfunction during diabetic retinopathy via NADPH oxidase

Retinal hyperpermeability and subsequent macular edema is a cardinal feature of early diabetic retinopathy (DR). Here, we investigated the role of bioactive lipid metabolites, in particular 12/15-lipoxygenase (LOX)-derived metabolites, in this process. LC/MS lipidomic screen of human retinal endothelial cells (HRECs) demonstrated that 15-HETE was the only significantly increased metabolite (2.4 ± 0.4-fold, P = 0.0004) by high glucose (30 mM) treatment. In the presence of arachidonic acid, additional eicosanoids generated by 12/15-LOX, including 12- and 11-HETEs, were significantly increased. Fluorescein angiography and retinal albumin leakage showed a significant decrease in retinal hyperpermeability in streptozotocin-induced diabetic mice lacking 12/15-LOX compared with diabetic WT mice. Our previous studies demonstrated the potential role of NADPH oxidase in mediating the permeability effect of 12- and 15-HETEs, therefore we tested the impact of intraocular injection of 12-HETE in mice lacking the catalytic subunit of NADPH oxidase (NOX2). The permeability effect of 12-HETE was significantly reduced in NOX2−/− mice compared with the WT mice. In vitro experiments also showed that 15-HETE induced HREC migration and tube formation in a NOX-dependent manner. Taken together our data suggest that 12/15-LOX is implicated in DR via a NOX-dependent mechanism.National Institutes of Health Grant 5R01EY023315 and National Priorities Research Program Grant 4-1046-3-284 from the Qatar National Research Fund (a member of Qatar Foundation). This study was also supported in part by the National Center for Research Resources, National Institutes of Health Grant S10RR027926

The Inflammatory Response and Cardiac Repair After Myocardial Infarction

One of the most important therapeutic targets of current cardiology practice is to determine optimal strategies for the minimization of myocardial necrosis and optimization of cardiac repair following an acute myocardial infarction. Myocardial necrosis after acute myocardial infarction induces complement activation and free radical generation, triggering a cytokine cascade initiated by tumor necrosis factor-alpha (TNF-α) release. When reperfusion of the infarcted area is initiated, intense inflammation follows. Chemokines, cytokines and the complement system play an important role in recruiting neutrophils in the ischemic and reperfused myocardium. Cytokines promote adhesive interactions between leukocytes and endothelial cells, resulting in transmigration of inflammatory cells into the site of injury. The recruited neutrophils have potent cytotoxic effects through the release of proteolytic enzymes, and they interact with adhesion molecules on cardiomyocytes. In spite of the potential injury, reperfusion enhances cardiac repair; this may be related to the inflammatory response. Monocyte chemoattractant protein (MCP)-1 is upregulated in reperfused myocardium and can induce monocyte recruitment in the infarcted area. Monocyte subsets play a role in phagocytosis of dead cardiomyocytes and in granulation tissue formation. In addition, the transforming growth factor (TGF)-β plays a crucial role in cardiac repair by suppressing inflammation. Resolution of inflammatory infiltration, containment of inflammation and the reparative response affecting the infarcted area are essential for optimal infarct healing. Here, we review the current literature on the inflammatory response and cardiac repair after myocardial infarction

Mitochondrial reactive oxygen species promote production of proinflammatory cytokines and are elevated in TNFR1-associated periodic syndrome (TRAPS)

ROS generated by mitochondrial respiration are needed for optimal proinflammatory cytokine production in healthy cells, and are elevated in cells from patients with an autoinflammatory disorder

The Role of Antioxidation and Immunomodulation in Postnatal Multipotent Stem Cell-Mediated Cardiac Repair

Oxidative stress and inflammation play major roles in the pathogenesis of coronary heart disease including myocardial infarction (MI). The pathological progression following MI is very complex and involves a number of cell populations including cells localized within the heart, as well as cells recruited from the circulation and other tissues that participate in inflammatory and reparative processes. These cells, with their secretory factors, have pleiotropic effects that depend on the stage of inflammation and regeneration. Excessive inflammation leads to enlargement of the infarction site, pathological remodeling and eventually, heart dysfunction. Stem cell therapy represents a unique and innovative approach to ameliorate oxidative stress and inflammation caused by ischemic heart disease. Consequently, it is crucial to understand the crosstalk between stem cells and other cells involved in post-MI cardiac tissue repair, especially immune cells, in order to harness the beneficial effects of the immune response following MI and further improve stem cell-mediated cardiac regeneration. This paper reviews the recent findings on the role of antioxidation and immunomodulation in postnatal multipotent stem cell-mediated cardiac repair following ischemic heart disease, particularly acute MI and focuses specifically on mesenchymal, muscle and blood-vessel-derived stem cells due to their antioxidant and immunomodulatory properties