CREATING A SOLID FOUNDATION FOR CREDIBLE U.S. EXTENDED DETERRENCE ON THE KOREAN PENINSULA

While the United States has reduced the overall number of nuclear warheads supporting U.S. extended deterrence in East Asia, North Korea has been developing additional nuclear weapons and missiles to maintain a stronger security posture against the United States. Therefore, South Korea, which is protected by the U.S. nuclear umbrella, is getting more skeptical of the credibility of the U.S. nuclear policy in regard to South Korea. Meanwhile, a well-organized North Atlantic Treaty Organization (NATO) Nuclear Planning Group (NPG) has assured allies of the credibility of the U.S. extended deterrence policy in Europe. This study demonstrates that South Korea could enhance its assurance of U.S. commitment to extended deterrence by adopting the NATO NPG as a model of a nuclear consultative body. Enhancing South Korea-U.S. nuclear policy coordination as presented in this thesis would bolster extended deterrence of North Korea's threats and enhance South Korea's assurance of U.S. extended deterrence.Captain, Republic of Korea ArmyApproved for public release. Distribution is unlimited

大腸菌のL-アラニン排出輸送体AlaEの機能解析

Tohoku University米山裕課

Characteristics of Antibiotic Resistance and Tolerance of Environmentally Endemic <i>Pseudomonas aeruginosa</i>

Antibiotic-resistant bacteria remain a serious public health threat. In order to determine the percentage of antibiotic-resistant and -tolerant Pseudomonas aeruginosa cells present and to provide a more detailed infection risk of bacteria present in the environment, an isolation method using a combination of 41 °C culture and specific primers was established to evaluate P. aeruginosa in the environment. The 50 strains were randomly selected among 110 isolated from the river. The results of antibiotic susceptibility evaluation showed that only 4% of environmental strains were classified as antibiotic-resistant, while 35.7% of clinical strains isolated in the same area were antibiotic-resistant, indicating a clear difference between environmental and clinical strains. However, the percentage of antibiotic-tolerance, an indicator of potential resistance risk for strains that have not become resistant, was 78.8% for clinical strains and 90% for environmental strains, suggesting that P. aeruginosa, a known cause of nosocomial infections, has a high rate of antibiotic-tolerance even in environmentally derived strains. It suggested that the rate of antibiotic-tolerance is not elicited by the presence or absence of antimicrobial exposure. The combination of established isolation and risk analysis methods presented in this study should provide accurate and efficient information on the risk level of P. aeruginosa in various regions and samples