156 research outputs found
Three Essays on the Effectiveness of Foreign Aid
Throughout three essays, this dissertation investigates three important aspects of the effectiveness of foreign aid: whether and how foreign aid is effective. Chapter 1 explains the background of the study on foreign aid. This introduction chapter also summarizes my arguments and the empirical strategies of each essay. Chapter 2 analyzes when foreign aid helps the recipient countries’ economic growth. In specific, this chapter argues that the political leaders’ survival strategy determines how to spend the aid, and it makes the difference in the aid effectiveness to achieve economic growth. Using a panel dataset for the 82 aid recipient countries between 1960 and 2010, this study finds that foreign aid is more likely to lead to economic growth in the case of a large winning coalition. In Chapter 3, I examine how foreign aid reduces political violence in recipient countries. Based on the findings of Chapter 2, I further argue that aid recipients experience less political violence due to its contribution to economic growth. Utilizing a moderated mediation model, I find that the recipient country achieves positive economic growth in a large winning coalition and consequently experiences fewer civil wars and domestic terrorist attacks. Chapter 4 investigates the effectiveness of foreign aid from the perspective of the donor country. In particular, I argue that foreign aid leads to more export of donor country to the recipient because implementing aid serves as building and enhancing the relationship between donors and recipients. Using Korean bilateral aid and export data to recipient countries between 1965 and 2015, this chapter shows that bilateral aid increases the donor’s export toward recipient countries. The effect becomes more prominent in the long term. Chapter 5 concludes. This concluding chapter emphasizes the main arguments and findings and draws aid policy recommendations
Understanding the perspectives, practices, and expectations of Korean American parents toward the heritage language education of their children
The purpose of this qualitative study, conducted with parents of a Bay Area Korean school, was to explore how Korean American parents perceive, practice, and expect from the heritage language education of their children. The parents shared their experiences as Korean immigrants in raising their children in two languages. First, a survey was distributed and collected to apprehend the demographics of 24 Korean American parents in a West Coast metropolitan area who sent their children to a Korean heritage language school on weekends. Then one-on-one in-depth interviews were conducted with seven of these parents. Seven themes emerged from the data: 1) the importance of the parental role in heritage language education, 2) maintaining the Korean language and ethnic identity, 3) limited exposure to the Korean language, 4) positive feelings towards the Korean culture and language, 5) no strict family language policy, 6) no high expectations for heritage language learning, and 7) diminishing the Korean language use with the start of schooling. Even though the parents regarded heritage language maintenance as important for their children and viewed their parental role was significant, they did not impose a strict family language policy. The underlying reason for this discrepancy in their perceptions, expectations, and practices could be the wish for their children to learn the Korean language someday primarily in order to maintain their Korean identity
Water vapor in high-mass star-forming regions and PDRs:Tracing the dynamics and chemistry with Herschel/HIFI
Massive stars play a major role in the interstellar energy budget and the shaping of the galactic environment. The water molecule is thought to be a sensitive tracer of physical conditions in star-forming regions because of its large abundance variations between hot and cold regions. Herschel/HIFI allows us to observe the multiple rotational transitions of H2O including the ground-state levels, and its isotopologues toward high-mass star-forming regions in different evolutionary stages. Photodissociation regions (PDRs) are also targeted to investigate the distribution of water and its chemistry. We present line profiles and maps of H2O using data from two programs “Water In Star-forming regions with Herschel” and “Herschel observations of EXtra-Ordinary Sources”. We estimate turbulent and expansion velocities, and abundance of water in the inner and outer envelopes using the 1D radiative transfer code. We find H2O abundances of ~10-8–10-9 for the outer envelope and ~10-4–10-5 for the inner envelope, and expansion and turbulent velocities range from 1.0 km s-1 to 2.5 km s-1. The Herschel/HIFI mapping observations of H2O toward the Orion Bar show that H2O emission peaks between the shielded dense gas and the radicals position, in agreement with the theoretical and the observational PDR structure. The derived H2O abundance is ~10-7 and peaks at the depth of AV ~8 mag from the ionization front. Together with the low ortho-to-para ratio of H2O (~1) presented by Choi et al. (2014), our results show that the chemistry of water in the Orion Bar is dominated by photodesorption
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The Spitzer C2D Survey of Nearby Dense Cores: Jet and Molecular Outflow Associated With A Young Stellar Object in Core A of L1251
A long infrared jet has been discovered by the Spitzer c2d Legacy Program in core A of L1251. It is associated with a very embedded Class 0 object with an accretion luminosity of about 0.9 L(circle dot) derived by radiative transfer model fitting to the observed spectral energy distribution. Comparing the observed Infrared Array Camera colors along the infrared jet with those calculated from a model of an admixture of gas with a power-law temperature distribution indicates that the jet is possibly created by a paraboloidal bow shock propagating into the ambient medium of n(H(2)) = 10(5) cm(-3). In addition, the variation of the power-law index along the jet suggests that the portion of hot gas decreases with distance from the jet engine. The molecular outflow in this region has been mapped for the first time using CO data. From the calculated outflow momentum flux, a very strong lower limit to the average accretion luminosity is 3.6 sin i/cos(3) i L(circle dot), indicative of a decrease in the accretion rate with time.Korean government (MEST) 2009-0062865NRF R01-2007-000-20336-0NASA 1407, 1224608Astronom
Air pollution and hemorrhagic fever with renal syndrome in South Korea: an ecological correlation study
Background : The effects of air pollution on the respiratory and cardiovascular systems, and the resulting impacts on public health, have been widely studied. However, little is known about the effect of air pollution on the occurrence of hemorrhagic fever with renal syndrome (HFRS), a rodent-borne infectious disease. In this study, we evaluated the correlation between air pollution and HFRS incidence from 2001 to 2010, and estimated the significance of the correlation under the effect of climate variables. Methods : We obtained data regarding HFRS, particulate matter smaller than 10 μm (PM10) as an index of air pollution, and climate variables including temperature, humidity, and precipitation from the national database of South Korea. Poisson regression models were established to predict the number of HFRS cases using air pollution and climate variables with different time lags. We then compared the ability of the climate model and the combined climate and air pollution model to predict the occurrence of HFRS. Results : The correlations between PM10 and HFRS were significant in univariate analyses, although the direction of the correlations changed according to the time lags. In multivariate analyses of adjusted climate variables, the effects of PM10 with time lags were different. However, PM10 without time lags was selected in the final model for predicting HFRS cases. The model that combined climate and PM10 data was a better predictor of HFRS cases than the model that used only climate data, for both the study period and the year 2011. Conclusions : This is the first report to document an association between HFRS and PM10 level.This work was supported by a grant from the Korean Healthcare Technology R&D Project, Ministry for Health, Welfare & Family Affairs, Republic of Korea (A084001).Peer Reviewe
Mid- CO Line Observations of Protostellar Outflows in the Orion Molecular Clouds
Ten protostellar outflows in the Orion molecular clouds were mapped in the
CO/CO and CO
lines. The maps of these mid- CO lines have an angular resolution of about
10 and a typical field size of about 100. Physical parameters of the
molecular outflows were derived, including mass transfer rates, kinetic
luminosities, and outflow forces. The outflow sample was expanded by
re-analyzing archival data of nearby low-luminosity protostars, to cover a wide
range of bolometric luminosities. Outflow parameters derived from other
transitions of CO were compared. The mid- () and
low- () CO line wings trace essentially the same outflow
component. By contrast, the high- (up to )
line-emission luminosity of CO shows little correlation with the kinetic
luminosity from the line, which suggests that they trace
distinct components. The low/mid- CO line wings trace long-term outflow
behaviors while the high- CO lines are sensitive to short-term activities.
The correlations between the outflow parameters and protostellar properties are
presented, which shows that the strengths of molecular outflows increase with
bolometric luminosity and envelope mass.Comment: 31 pages, 16 figures, Accepted for publication in ApJ
The relationship between hormone replacement therapy and periodontal disease in postmenopausal women: a cross-sectional study the Korea National Health and Nutrition Examination Survey from 2007 to 2012
Background
The purpose of this study was to investigate the relationship between hormone replacement therapy (HRT) and periodontal disease in postmenopausal women using data from the 4th and 5th Korea National Health and Nutrition Examination Survey (KNHANES).
Methods
The study included data from 5,482 postmenopausal women aged 45–74 years in the 2007–2012 KNHANES. The use of female HRT for at least one month was reclassified as HRT+/HRT-. The Community Periodontal Index of Treatment Needs (CPITN) was used to assess periodontal status. Propensity score matching (PSM) was used to control selection bias, and factors affecting education, family income, and age of menopause were used as covariates in PSM. A chi-square test was used to confirm the bivariate relationship between the variables. Binary logistic regression analysis was used to adjust for confounders (age, education, family income, body mass index, age of menopause, alcohol, smoking, dental clinic visits in the past one year, use of oral care products and frequency of tooth brushing per day).
Results
After adjusting for all covariates, HRT was associated with periodontal disease (OR: 0.79; 95% CI: 0.66–0.94). In particular, the relationship between HRT and periodontal disease was more evident in those with menopause under 45 years of age disease (OR: 0.55; 95% CI: 0.35–0.87).
Conclusions
The results of this study supported that it is important that hormone therapy be actively considered in the policy towards postmenopausal women. Especially, health programs such as hormone replacement therapy, non-smoking, and use of oral care products are needed for women who undergo premature menopause
Efficacy and Tolerability of GCSB-5 for Hand Osteoarthritis: A Randomized, Controlled Trial
AbstractPurposeThe aim of this study was to investigate the efficacy and tolerability of GCSB-5, a mixture of 6 purified herbal extracts, in treating hand osteoarthritis (OA).MethodsA randomized, double-blind, placebo-controlled trial enrolled 220 patients with hand OA who had baseline a visual analog scale joint pain score of >30 of 100 mm at 3 hospitals between September 2013 and November 2014. After randomization, patients were allocated to receive oral GCSB-5 600 mg or placebo, bid for 12 weeks. The primary end point was the change in the Australian/Canadian OA Hand Index (AUSCAN)-defined pain score at 4 weeks relative to baseline. Secondary end points included the frequency Outcome Measures in Rheumatology–OA Research Society International (OMERACT-OARSI)-defined response at 4, 8, 12, and 16 weeks after randomization.FindingsThe allocated treatment was received by 109 and 106 patients in the GCSB-5 and placebo groups, respectively. At 4 weeks, the median (interquartile range) change in AUSCAN pain score relative to baseline was significantly greater in the GCSB-5 group than in the placebo group (–9.0 [–23.8 to –0.4] vs –2.2 [–16.7 to 6.0]; P = 0.014), with sustained improvement at 8, 12, and 16 weeks (P = 0.039). The GCSB-5 group also had a significantly greater OMERACT-OARSI–defined response rate than did the placebo group at 4 weeks (44.0% vs 30.2%), 8 weeks (51.4% vs 35.9%), 12 weeks (56.9% vs 40.6%), and 16 weeks (50.5% vs 37.7%) (P = 0.0074). The 2 treatments exhibited comparable safety profiles.ImplicationsGCSB-5 was associated with improved symptoms of hand OA, with good tolerability, in these patients. GCSB-5 may be a well-tolerated alternative of, or addition to, the treatment of hand OA. ClinicalTrials.gov identifier: NCT01910116
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