160 research outputs found

    The Historical Development of Early Korean Immigration To Hawaii And Its Legal Structure

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    The Joseon dynasty opened its doors to the United States of America in 1882 and gradually to other western countries giving up its isolation policy. One of the dramatic results of this policy change was that Emperor Gojong granted permission to allow Korean emigration to Hawaii in 1902. The first group of 102 Korean immigrants, including 21 wives and 26 children under the age of 18, arrived at Honolulu Harbor on January 13, 1903. Approximately 7,400 Korean laborers immigrated to Hawaii in the next two and one half years until immigration ended in August 1905. The purpose of this paper is to review the legal structures that supported Korean immigration to Hawaii from 1903 to 1910, when the Daehan Empire lost its sovereign power. This article first reviews the socio-economic and legal conditions leading to importation of Chinese and Japanese laborers to the Kingdom of Hawaii prior to the arrival of Koreans. Then, Korea's diplomatic and legal arrangements for the immigration of Korean laborers are examined. American legal policies and structuresfor Korean immigrants are also reviewed

    Strain-shear coupling in bilayer MoS2

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    Layered materials such as graphite and transition metal dichalcogenides have extremely anisotropic mechanical properties owing to orders of magnitude difference between in-plane and out-of-plane interatomic interaction strengths. Although effects of mechanical perturbations on either intra- or inter-layer interactions have been extensively investigated, mutual correlations between them have rarely been addressed. Here we show that layered materials have an inevitable coupling between in-plane uniaxial strain and interlayer shear. Because of this, the uniaxial in-plane strain induces an anomalous splitting of the degenerate interlayer shear phonon modes such that the split shear mode along the tensile strain is not softened but hardened contrary to the case of intralayer phonon modes. We confirm the effect by measuring Raman shifts of shear modes of bilayer MoS2 under strain. Moreover, by analyzing the splitting, we obtain an unexplored off-diagonal elastic constant, demonstrating that Raman spectroscopy can determine almost all mechanical constants of layered materials.Comment: 36 pages, 10 figure

    Changes in activity and isozyme patterns of peroxidase and chitinase in kiwifruit pollen

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    In this study, changes in activity and isozyme patterns of peroxidase (POD) and chitinase in kiwifruit (Actinidia chinensis) pollen were investigated under different storage conditions. Although residual activity was detected in heat-treated pollen, changes in POD activity were observed due to difference in storage conditions as revealed by preliminary studies in which pollen germination varied with different storage conditions. POD activity of kiwifruit pollen increased as proportions of viable pollen increased, indicating a positive correlation (R2=0.993) between pollen viability and POD activity. There was a detectable difference in the relative activity of POD enzyme between heat-treated and viable pollen. Decoloration of Congo Red was observed in germination medium which fresh pollen was cultured. The activity of individual chitinase isozymes present in kiwifruit pollen differed depending on storage conditions, which had a direct impact on pollen vigor. Although direct evidence showing that chitinase isozymes are implicated in pollen vigor is still uncertain, distinction of isozymes may facilitate more precise identification of viable pollen which possesses germination potential from non-viable pollen. Taken together, these results suggest that monitoring the activity of POD and chitinase can be an attractive alternative to evaluate pollen vigor in kiwifruit

    Characteristics of blood tests in patients with acute cerebral infarction who developed symptomatic intracranial hemorrhage after intravenous administration of recombinant tissue plasminogen activator

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    Objective Patients suspected as having acute ischemic stroke usually undergo blood tests, including coagulation-related indexes, because thrombocytopenia and coagulopathy are contraindications for recombinant tissue plasminogen activator (rtPA) administration. We aimed to identify blood test indexes associated with symptomatic intracranial hemorrhage (sICH) in patients with acute ischemic stroke who received intravenous rtPA. Methods This retrospective observational study included patients diagnosed with acute ischemic stroke who were treated with intravenous rtPA at the emergency department of a tertiary hospital in Seoul between February 2008 and January 2018. Blood test indexes were compared between the sICH and non-sICH groups. Logistic regression and receiver-operating characteristic curve analyses were performed. Results In this study, 375 patients were finally included. Of 375 patients, 42 (11.2%) showed new intracranial hemorrhage on follow-up brain computed tomography, of whom 14 (3.73%) had sICH. Platelet count, aspartate aminotransferase and lactate dehydrogenase levels were significantly different between the sICH and non-sICH groups, and platelet count showed statistical significance in the regression analysis. Significantly lower platelet counts were observed in the sICH group than in the non-sICH group (174,500 vs. 228,000/mm3, P=0.020). The best cutoff platelet count was 195,000/mm3, and patients with platelet counts of <195,000/mm3 had a 5.4- times higher risk of developing sICH than those with platelet counts of ≥195,000/mm3. Conclusion Platelet count was the only independent parameter associated with sICH among the blood test indexes. Mild thrombocytopenia may increase the risk of sICH after intravenous administration of rtPA

    Electrically Robust Single-Crystalline WTe2 Nanobelts for Nanoscale Electrical Interconnects

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    As the elements of integrated circuits are downsized to the nanoscale, the current Cu-based interconnects are facing limitations due to increased resistivity and decreased current-carrying capacity because of scaling. Here, the bottom-up synthesis of single-crystalline WTe2 nanobelts and low- and high-field electrical characterization of nanoscale interconnect test structures in various ambient conditions are reported. Unlike exfoliated flakes obtained by the top-down approach, the bottom-up growth mode of WTe2 nanobelts allows systemic characterization of the electrical properties of WTe2 single crystals as a function of channel dimensions. Using a 1D heat transport model and a power law, it is determined that the breakdown of WTe2 devices under vacuum and with AlOx capping layer follows an ideal pattern for Joule heating, far from edge scattering. High-field electrical measurements and self-heating modeling demonstrate that the WTe2 nanobelts have a breakdown current density approaching approximate to 100 MA cm(-2), remarkably higher than those of conventional metals and other transition-metal chalcogenides, and sustain the highest electrical power per channel length (approximate to 16.4 W cm(-1)) among the interconnect candidates. The results suggest superior robustness of WTe2 against high-bias sweep and its possible applicability in future nanoelectronics

    Comparison of the antibody responses to Plasmodium vivax and Plasmodium falciparum antigens in residents of Mandalay, Myanmar

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    <p>Abstract</p> <p>Background</p> <p>The aim of this study was to investigate the profile of antibodies against several antigens of <it>Plasmodium vivax </it>and <it>Plasmodium falciparum </it>in Mandalay, Myanmar.</p> <p>Methods</p> <p>Malaria parasites were identified by microscopic examination. To test the antibodies against <it>P. vivax </it>and <it>P. falciparum </it>in sera, an indirect immunofluorescence antibody test (IFAT) was performed using asexual blood parasite antigens. An enzyme-linked immunosorbent assay (ELISA) was performed with circumsporozoite protein (CSP), Pvs25 and Pvs28 recombinant proteins of transmission-blocking vaccine candidates for <it>P. vivax</it>, and liver stage specific antigen-1 and -3 (PfLSA-1, PfLSA-3) for <it>P. falciparum</it>.</p> <p>Results</p> <p>Fourteen patients among 112 were found to be infected with <it>P. vivax </it>and 26 with <it>P. falciparum </it>by thick smear examination. Twenty-three patients were found to be infected with <it>P. vivax</it>, 19 with <it>P. falciparum </it>and five with both by thin smear examination. Blood samples were divided into two groups: Group I consisted of patients who were positive for infection by microscopic examination, and Group II consisted of those who showed symptoms, but were negative in microscopic examination. In <it>P. falciparum</it>, IgG against the blood stage antigen in Group I (80.8%) was higher than in Group II (70.0%). In <it>P. vivax</it>, IgG against the blood stage antigen in Group I (53.8%) was higher than in Group II (41.7%). However, the positivity rate of the PvCSP VK210 subtype in Group II (40.0%) was higher than in Group I (23.1%). Similarly for the PvCSP VK247 subtype, Group II (21.7%) was higher than that for Group I (9.6%). A similar pattern was observed in the ELISA using Pvs25 and Pvs28: positive rates of Group II were higher than those for Group I. However, those differences were not shown significant in statistics.</p> <p>Conclusions</p> <p>The positive rates for blood stage antigens of <it>P. falciparum </it>were higher in Group I than in Group II, but the positive rates for antigens of other stages (PfLSA-1 and -3) showed opposite results. Similar to <it>P. falciparum</it>, the positive rate of pre-blood stage (CSP VK210 and 247 subtype) and post-blood stage (Pvs25 and 28) antigens of <it>P. vivax </it>were higher in Group II than in Group I. Therefore, sero-diagnosis is not helpful to discriminate between malaria patients and symptomatic individuals during the epidemic season in Myanmar.</p

    Propyl Gallate Inhibits Adipogenesis by Stimulating Extracellular Signal-Related Kinases in Human Adipose Tissue-Derived Mesenchymal Stem Cells

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    Propyl gallate (PG) used as an additive in various foods has antioxidant and anti-inflammatory effects. Although the functional roles of PG in various cell types are well characterized, it is unknown whether PG has effect on stem cell differentiation. In this study, we demonstrated that PG could inhibit adipogenic differentiation in human adipose tissue-derived mesenchymal stem cells (hAMSCs) by decreasing the accumulation of intracellular lipid droplets. In addition, PG significantly reduced the expression of adipocyte-specific markers including peroxisome proliferator-activated receptor-gamma (PPAR-gamma), CCAAT enhancer binding protein-alpha (C/EBP-alpha), lipoprotein lipase (LPL), and adipocyte fatty acid-binding protein 2 (aP2). PG inhibited adipogenesis in hAMSCs through extracellular regulated kinase (ERK) pathway. Decreased adipogenesis following PG treatment was recovered in response to ERK blocking. Taken together, these results suggest a novel effect of PG on adipocyte differentiation in hAMSCs, supporting a negative role of ERK1/2 pathway in adipogenic differentiationclose

    The genome sequence of Xanthomonas oryzae pathovar oryzae KACC10331, the bacterial blight pathogen of rice

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    The nucleotide sequence was determined for the genome of Xanthomonas oryzae pathovar oryzae (Xoo) KACC10331, a bacterium that causes bacterial blight in rice (Oryza sativa L.). The genome is comprised of a single, 4 941 439 bp, circular chromosome that is G + C rich (63.7%). The genome includes 4637 open reading frames (ORFs) of which 3340 (72.0%) could be assigned putative function. Orthologs for 80% of the predicted Xoo genes were found in the previously reported X.axonopodis pv. citri (Xac) and X.campestris pv. campestris (Xcc) genomes, but 245 genes apparently specific to Xoo were identified. Xoo genes likely to be associated with pathogenesis include eight with similarity to Xanthomonas avirulence (avr) genes, a set of hypersensitive reaction and pathogenicity (hrp) genes, genes for exopolysaccharide production, and genes encoding extracellular plant cell wall-degrading enzymes. The presence of these genes provides insights into the interactions of this pathogen with its gramineous host

    Haloperidol regulates the phosphorylation level of the MEK-ERK-p90RSK signal pathway via protein phosphatase 2A in the rat frontal cortex

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    Haloperidol, a classical antipsychotic drug, affects the extracellular signal-regulated kinase (ERK) pathway in the brain. However, findings are inconsistent and the mechanism by which haloperidol regulates ERK is poorly understood. Therefore, we examined the ERK pathway and the related protein phosphatase 2A (PP2A) in detail after haloperidol administration. Haloperidol (0.5 and 1 mg/kg) induced biphasic changes in the phosphorylation level of mitogen-activated protein kinase kinase (MEK), ERK, and p90 ribosomal S6 kinase (p90RSK) without changing Raf-1 phosphorylation. Fifteen minutes after haloperidol administration, MEK-ERK-p90RSK phosphorylation increased, whilst PP2A activity decreased. At 60 min, the reverse was observed and the binding of PP2A to MEK and ERK increased. Higher dosages of haloperidol (2 and 4 mg/kg), affected neither MEK-ERK-p90RSK phosphorylation nor PP2A activity. Accordingly, PP2A regulates acute dose- and time-dependent changes in MEK-ERK-p90RSK phosphorylation after haloperidol treatment. These findings suggest the involvement of a dephosphorylating mechanism in the acute action of haloperidol
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