CAN TRUST BE LEARNED IN HETEROGENEOUS ENVIRONMETNS? AN INTEGRATIVE MODEL OF POLITICAL AND SOCIAL LEARNING THROUGH DEMOCRACY

While the virtues of social capital in democracies are widely recognized, previous studies have repeatedly shown that social capital is in short supply in heterogeneous communities with ethnic minorities. Against the view that levels of social capital are culturally predetermined, I argue that it is possible to generate social capital by carefully formulating political institutions. Drawing from theories of institutional management of ethnic conflict and theories of institutional learning, I construct an integrated theory of social capital which hypothesizes that citizens learn to trust one another based on their experiences with political institutions during an extended period of democratic rule. To test this integrated model of social capital, I use a probit analysis to examine how democratic longevity in different institutional settings (e.g., majoritarian vs. consensus) influences social capital. To overcome the endogeneity problem that exists between social capital and democratic longevity, I adopt an instrumental variables approach, drawing on theories in international relations. My analysis of World Values Survey data yields three main conclusions concerning the institutional arrangements that foster social capital. First, I find that democratic longevity fosters higher levels of trust in countries with consensus institutions containing powersharing arrangements through cabinets, executive-legislative balances, party systems, and electoral systemspresumably because cooperation among different groups enhances social capital. Second, a longer period of democratic rule in highly federal institutions undermines trust, as the devolution of powers through territorial units is thought to fragment the political system and society. Finally, consistent with the theoretical expectations, I find that these two conclusions hold only among ethnic minorities. Among ethnic majorities, the effect of democratic longevity disappears once we purge the endogenous component (i.e., the effect of social capital on democratic longevity), using an instrumental variables approach. Case studies of the Baltic States, the Canadian province of Quebec, and Malaysia corroborated the findings from the statistical analyses. By uncovering a mechanism through which social capital can be generated in multiethnic states, this study makes an important contribution to the literature

Black Lives Matter and the Effects of a Social Media User\u27s Connection to Differing Ethnic and Racial Backgrounds

Millions of citizens, including a large number of whites, joined the Black Lives Matter (BLM) movement in the summer of 2020. An important factor that mobilized them toward BLM was the rise of social media. Recognizing the critical importance of social media, the present research explores the link between social media use and citizens’ behavior on the BLM movement in the United States. The focus of the analysis is on the issue of diversity. Because diversity on social networks can expose individuals to more diverse views, one can hypothesize that a higher number of one’s friends and followers being from different racial and ethnic backgrounds can lead to higher levels of activism in the BLM movement. In order to test the hypotheses, we conducted a survey in the United States specifically tailored for this study. A statistical analysis on the survey data reveals that diversity in one\u27s social networks on social media significantly enhances his or her likelihood of participation in the BLM protest. Yet, the significant effect disappears when the samples are limited to white respondents; it is clearly non-white respondents who are driving the significant result of diversity of social networks. This study makes an important contribution to the literature of social movements by dissecting the mechanism through which social media shapes citizens’ relations with BLM. Findings from this study generate critical implications that are essential in understanding dynamics of social movements in modern society

Formation of Galactic Center Magnetic Loops

A survey for the molecular clouds in the Galaxy with NANTEN mm telescope has discovered molecular loops in the Galactic center region. The loops show monotonic gradients of the line of sight velocity along the loops and the large velocity dispersions towards their foot points. It is suggested that these loops are explained in terms of the buoyant rise of magnetic loops due to the Parker instability. We have carried out global three-dimensional magneto-hydrodynamic simulations of the gas disk in the Galactic center. The gravitational potential is approximated by the axisymmetric potential proposed by Miyamoto & Nagai (1975). At the initial state, we assume a warm (~ 10^4 K) gas torus threaded by azimuthal magnetic fields. Self-gravity and radiative cooling of the gas are ignored. We found that buoyantly rising magnetic loops are formed above the differentially rotating, magnetically turbulent disk. By analyzing the results of global MHD simulations, we have identified individual loops, about 180 in the upper half of the disk, and studied their statistical properties such as their length, width, height, and velocity distributions along the loops. Typical length and height of a loop are 1kpc and 200pc, respectively. The line of sight velocity changes linearly along a loop and shows large dispersions around the foot-points. Numerical results indicate that loops emerge preferentially from the region where magnetic pressure is large. We argue that these properties are consistent with those of the molecular loops discovered by NANTEN.Comment: 16pages, 10figures. Accepted for publication in PASJ. Replace to higher resolution versio

Hepatitis C Virus-Related Lymphomagenesis in a Mouse Model

B cell non-Hodgkin lymphoma is a typical extrahepatic manifestation frequently associated with hepatitis C virus (HCV) infection. The mechanism by which HCV infection leads to lymphoproliferative disorder remains unclear. Our group established HCV transgenic mice that expressed the full HCV genome in B cells (RzCD19Cre mice). We observed a 25.0% incidence of diffuse large B cell non-Hodgkin lymphomas (22.2% in male and 29.6% in female mice) within 600 days of birth. Interestingly, RzCD19Cre mice with substantially elevated serum-soluble interleukin-2 receptor α-subunit (sIL-2Rα) levels (>1000 pg/mL) developed B cell lymphomas. Another mouse model of lymphoproliferative disorder was established by persistent expression of HCV structural proteins through disruption of interferon regulatory factor-1 (irf-1_/_/CN2 mice). Irf-1_/_/CN2 mice showed extremely high incidences of lymphomas and lymphoproliferative disorders. Moreover, these mice showed increased levels of interleukin (IL)-2, IL-10, and Bcl-2 as well as increased Bcl-2 expression, which promoted oncogenic transformation of lymphocytes