The focus of this dissertation is twofold : First, it examines whether Korean exhibits island effects, as the status of islands in Korean and typologically related wh- in-situ languages has been unclear. Second, it explores whether Korean-English bilinguals display native-like island effects in their two languages. While most accounts of island effects claim that the input is not directly involved and that islands stem from basic properties of grammar/processing that are available to all humans, another line of accounts claims that islands actually can be learned from the input. These different approaches to the learnability issue on islands would then predict different outcomes for bilinguals. Under the accounts claiming that islands are not learned but available to all speakers regardless of one's learning environments, we might expect native-like island effects in bilinguals regardless of their learning environment. On the other hand, if input plays an important role in having island effects, as the second position argues, then bilinguals might be expected to show non-native-like and/or various types of island effects. Four acceptability experiments on island effects in Korean (involving a whether-island and an adjunct island) in native and Korean-English bilinguals (i.e. heritage speakers of Korean) revealed the presence of a whether-island but the absence of an adjunct island in Korean in both native and heritage speakers of Korean. Another five acceptability experiments on island effects in English (a whether-island, a wh-island, and three types of adjunct islands) showed that Korean-English bilinguals, grouped according to their AoA (i.e. Heritage: AoA 0-5, Early: AoA 6-10, and Late: AoA 11-14), displayed adjunct island effects but either had weaker whether/wh-island effects than native speakers or lacked these effects altogether. Their island effect sizes, measured by DD scores, indicated that islands get weaker with increasing AoA. There was also found a positive correlation between AoA and length effects in bilinguals, suggesting a difficulty with long-distance dependencies as AoA increases. These results are discussed in light of the cross-linguistic similarities and differences in islands, and the role of input in island effects

The current research explores the role of two different motives underlying volunteering (or defecting) in a simple economic game. We find in Study 1 that in a symmetric Volunteer’s Dilemma (VoD) the willingness to volunteer is reduced more strongly by an increase in the payoff for unilateral defection (suggesting more greed) than by an increase in the payoff for mutual defection (suggesting less fear). In Study 2, we replicate this finding when only the participants’ own payoffs are varied, but not when only the other player’s payoffs are varied. These findings are inconsistent with standard (i.e., Nash) game-theoretic predictions and Schelling’s focal-point hypothesis. Instead, the empirical patterns suggest that participants approach the VoD using egocentric decision heuristics.

Microaggressions are unintentional or thoughtless behaviors that convey negative messages to members of minoritygroups. Due to the attributional ambiguity of microaggressions, people often differ in their judgments about how morally badacts of microaggression are. To account for this individual variation, we explored the potential influence of heavy social mediause on individuals’ moral judgments of microaggressive behaviors. We hypothesized that, because of the relative acceptance ofstrong blame expressions on social media, heavy Facebook users would endorse intense moral criticism of microaggressions.Participants read about several agents who committed microaggressions and judged the appropriateness of moral criticism(pretested to vary in degrees from “disapprove of,” “chastise,” “chew out,” to “lash out at”) that a friend directed towards theoffender. Consistent with our hypothesis, we found a strong correlation (r = .47) between increasing degrees of Facebook useand increasing acceptance of harsher moral criticism for microaggressions.

Extracellular vesicles (EVs) have emerged as vehicles that mediate diverse cell-cell communication. However, in-depth understanding of these vesicles is hampered by a lack of a reliable isolation method to separate different types of EVs with high levels of integrity and purity. Here, we developed a nanoporous and ultra-thin membrane structure (NUTS) that warrants the size-based isolation of EVs without cake formation, minimizing the sample loss during the filtration process. By utilizing the micro-electro-mechanical systems (MEMS) technique, we could also control the pore size in nanoscale. We validated the performance of this membrane to separate EVs according to their size range.

Exercise is among the most effective interventions for age-associated mobility decline and metabolic dysregulation. Although long-term endurance exercise promotes insulin sensitivity and expands respiratory capacity, genetic components and pathways mediating the metabolic benefits of exercise have remained elusive. Here, we show that Sestrins, a family of evolutionarily conserved exercise-inducible proteins, are critical mediators of exercise benefits. In both fly and mouse models, genetic ablation of Sestrins prevents organisms from acquiring metabolic benefits of exercise and improving their endurance through training. Conversely, Sestrin upregulation mimics both molecular and physiological effects of exercise, suggesting that it could be a major effector of exercise metabolism. Among the various targets modulated by Sestrin in response to exercise, AKT and PGC1α are critical for the Sestrin effects in extending endurance. These results indicate that Sestrin is a key integrating factor that drives the benefits of chronic exercise to metabolism and physical endurance.