Improvement of conversion efficiency of atom-molecule Bose-Einstein condensate

We investigate the stimulated Raman adiabatic passage in two-color photoassociation for a atom-molecule Bose-Einstein condensate. By applying two time-varying Guassian laser pulses that fulfill generalized two-photon resonance condition, we obtain highly efficient atom-molecule conversion. The efficiency depends on the free-bound detuning and the delay time between the two pulses. By adjusting the parameters optimally, we achieve 92% conversion efficiency.Comment: 4 pages, 4 figures. To be appeared in J. Korean Phys. Society (JKPS

Storage of spin squeezing in a two-component Bose-Einstein condensate

Efficient control of spin squeezing in a two-component Bose-Einstein Condensate is studied by rapidly turning-off the external field at a time that maximal spin squeezing appears. We show that strong reduction of spin fluctuation can be maintained in a nearly fixed direction for a long time. We explain the underlying physics unambiguously, and present analytical expressions of the maximal-squeezing time.Comment: 10 pages, 5 figures. This version is slightly different from the one published in Phys. Rev. Let

Spin squeezing and maximal-squeezing time

Spin squeezing of a nonlinear interaction model with Josephson-like coupling is studied to obtain time scale of maximal squeezing. Based upon two exactly solvable cases for two and three particles, we find that the maximal-squeezing time depends on the level spacing between the ground state and its next neighbor eigenstate.Comment: 7 pages, 5 figures, 1 table. Resubmitted to Phys. Rev.

Private transfers and emerging welfare states in East Asia: Comparative perspectives

Empirical studies on income distribution and poverty have indicated that the public transfer system has been successful in terms of poverty and inequality reduction in welfare states. However, very little attention has been paid to private transfers in this analysis. Recently, while there has been an increasing interest in the unique features of East Asian welfare states/regimes, many scholars have begun to have an interest in the role of the family in their welfare mix. This article aims to widen the scope of comparative income studies, firstly by analyzing 12 Western welfare states and two newly emerging East Asian welfare states, i.e. South Korea and Taiwan, and secondly, by comparing the poverty and inequality reduction effects of private transfers with those of public transfers. The Luxemburg Income Study dataset is used for the analysis. The empirical results indicate that private transfers are much more effective than public transfers in terms of income inequality and poverty reduction effects in both South Korea and Taiwan, in contrast to western counterparts including three Southern European countries. Finally, based on the results, we propose further research questions

Feminisation of poverty in 12 welfare states: Strengthening cross-regime variations?

The feminisation of poverty is said to have become a common feature in the majority of advanced welfare states, but it is equally true that there has been significant variation in the feminisation of poverty from one country to another. While the concept of the feminisation of poverty remains controversial, there have been very few attempts to reveal a detailed picture from a comparative perspective. Considering this background, this study aims to illustrate the feminisation of poverty in 12 welfare states (Liberal - Australia, Canada, UK, US; Conservative - Austria, France, Germany, Italy; Nordic - Denmark, Finland, Norway, Sweden) between the 1980s and the 2000s and to analyse whether or not there has been any convergence or divergence between these welfare states. This study will evaluate the scope and depth of the feminisation of poverty by conducting analyses not only in terms of different sex, but in terms of different population groups. Further, the changing role of welfare states will be assessed via an analysis of the antipoverty role of public transfers in each country. The Luxemburg Income Study dataset will be used for empirical analysis. This paper will argue that while the feminisation of poverty has been slowed down and even reversed in certain cases, cross-national differences have been increasingly visible. The results of this study also show that the welfare regime framework can prove to be a useful tool for understanding the similarities and the differences in the feminisation of poverty across different Western welfare state regimes

Epigenetic Regulation of Hepatitis B Virus Replication

Hepatitis B virus (HBV) is the most important cause of chronic viral hepatitis worldwide. The genome of HBV is 3.2 kb partially double-stranded DNA, which is translocated to the nuclei of infected hepatocytes and converted to complete double-stranded DNA, aka covalently closed circular DNA (cccDNA). Typical course of chronic HBV infection results in inactive carrier state with clearance of viral particles in the bloodstream. However, the cccDNA can be detected in the hepatocytes from inactive carriers by sensitive methods. It has been increasingly known that epigenetic mechanisms contribute to the control of HBV replication in the inactive stage of HBV infection. Histone modification and DNA methylation have been identified in the HBV cccDNA, leading to modification of transcriptional activity. The understanding of epigenetic control of transcription will shed light on the development of new therapeutic strategy against HBV cccDNA