392 research outputs found

    The Empirical Investigation of The Kemp-Jones Model: The Case of OECD Countries

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    This paper analyzes the impact of different production technologies on relative prices of various goods and through them on the pattern of trade in these goods. Perfect capital mobility and differences in technology across countries are assumed, consistent with the Kemp-Jones model. This allows one to focus on labor costs, rather than on both labor and capital costs. The sector-specific unit labor costs for each country (relative to those of other sectors within each country) determine the comparative advantage or disadvantage of each country in trade. These sector- and country-specific relative unit labor costs can be broken down into two components, (i) relative wage rates and (ii) relative labor requirements per unit of output. The latter can be further decomposed into two sub-components, (iii) relative capital requirements per unit of labor and (iv) relative rates of technical progress. The decomposition into these two sub-components is carried out by an econometric estimation of the translog production function for each of 10 traded good sectors (2-digit classification of International Sectoral Data Base, 1970-92) in 14 OECD countries, using 3SLS estimation method. The decomposition of country- and sector-specific unit labor costs results in various empirical findings; two of which are as follows. First, the Ricardian model claims that the relative labor requirements are the key determinant of comparative advantage. The empirical evidence could only confirm this claim for the 1970s. Second, one of the main sources of the poor performance of the Heckscher-Ohlin theorem is widely agreed to be in cross-country differences in relative labor requirements. The decomposition of relative labor requirements into two sub-components indicates that such differences are highly correlated with cross-country differences in relative rates of technical progress in the light industries, but with cross-country differences in relative capital requirements in the heavy industries.

    Sulfonamides identified as plant immune-priming compounds in high-throughput chemical screening increase disease resistance in Arabidopsis thaliana

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    Plant activators are agrochemicals that protect crops from diseases by activating the plant immune system. To isolate lead compounds for use as practical plant activators, we screened two different chemical libraries composed of various bioactive substances by using an established screening procedure that can selectively identify immune-priming compounds. We identified and characterized a group of sulfonamide compounds – sulfameter, sulfamethoxypyridazine, sulfabenzamide, and sulfachloropyridazine – among the various isolated candidate molecules. These sulfonamide compounds enhanced the avirulent Pseudomonas-induced cell death of Arabidopsis suspension cell cultures and increased disease resistance in Arabidopsis plants against both avirulent and virulent strains of the bacterium. These compounds did not prevent the growth of pathogenic bacteria in minimal liquid media at 200 μM. They also did not induce the expression of defense-related genes in Arabidopsis seedlings, at least not at 24 and 48 h after treatment, suggesting that they do not act as salicylic acid analogs. In addition, although sulfonamides are known to be folate biosynthesis inhibitors, the application of folate did not restore the potentiation effects of the sulfonamides on pathogen-induced cell death. Our data suggest that sulfonamides potentiate Arabidopsis disease resistance by their novel chemical properties

    Myristic Acid, A Side Chain of Phorbol Myristate Acetate (PMA), Can Activate Human Polymorphonuclear Leukocytes to Produce Oxygen Radicals More Potently than PMA

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    Myristic acid (MyA), which is a saturated fatty acid (C14:0) and a side chain of phorbol 12-myristate 13-acetate (PMA), was examined if MyA stimulates human polymorphonuclear leukocytes (PMNs) to release oxygen radicals comparable to PMA by applying electron paramagnetic resonance (EPR)-spin-trapping method. When MyA was added to isolated human PMNs, spin adducts of 5,5-dimethyl-1-pyrroline-N-oxide (DMPO)-OH and DMPO-OOH were time-dependently observed. The amounts of these spin adducts were larger than those of PMNs stimulated by PMA. These results clearly show that MyA is more potent agent to prime human PMNs than PMA, in a point of view of not only O2·− but also ·OH production. This fact calls attention that too much intake of MyA that is known to be contained vegetable oils can lead to crippling effect through uncontrolled production of reactive oxygen species

    Device Failure in Bicuspid Aortic Stenosis Following Transcatheter Aortic Valve Implantation

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    Recent studies showed the favorable outcomes of transcatheter aortic valve implantation (TAVI) in patients with bicuspid aortic valve (BAV) stenosis. However, data on the rela-tion between BAV morphology and optimal transcatheter heart valve (THV) selection are limited. This study sought to evaluate the determinants of device performance in patients with BAV who underwent TAVI. Consecutive patients with BAV who under-went TAVI with the SAPIEN 3 from multicenters were evaluated. Outcomes were the incidence and predictors of device failure. Device failure was defined as peak aortic velocity > 3.0 m/s, mean pressure gradient > 20 mm Hg, moderate or severe paravalvular leakage and/or procedure mortality. A total of 187 patients with BAV were identified, aged 77 years, and 38.0% were women. A total of 37 patients (19.8%) were treated with 23-mm valve, 58 (31.0%) with 26-mm valve, and 92 (49.2%) with 29-mm valve. Predis -charge echocardiogram demonstrated 37 patients (19.8%) with device failure. BAV with excessive leaflet calcification plus calcified raphe (EC-BAV) (OR 16.7, 95% CI 1.99 to 39.6) and smaller THV (OR 4.41, 95% CI 1.43 to 13.6) were independently associated with increased risk of device failure. In addition, 4.0%, 5.1%, and 11.1% of device fail-ures were observed in patients without EC-BAV who underwent TAVI with 23-, 26-and 29-mm THV (p = 0.47), respectively, and 91.7%, 31.6% and 23.2% in those with EC-BAV, respectively (p < 0.001). In conclusion, EC-BAV morphology was the major deter-minant of a device failure after TAVI. Moreover, TAVI in patients with EC-BAV requir-ing small SAPIEN 3 could be challenging. Further data on device and treatment selection in patients with BAV are still warranted. (C) 2022 The Author(s). Published by Elsevier Inc.Peer reviewe

    Epidemiological Study of Japanese Encephalitis Virus in Vientiane, Lao PDR, in 1990s

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    Phylogenetic analysis of Japanese encephalitis virus (JEV) was conducted using core-premembrane and envelope gene sequence data of two strains from Vientiane, Lao People’s Democratic Republic, in 1993 and five from Okinawa, Japan, in 2002 and 2003, and previously published strains. The two Vientiane strains designated as LaVS56 and LaVS145 belonged to genotype 1 (G1) and the same subcluster of G1 as Australian strain in 2000, Thai strains in 1982–1985 and 2004-2005, and Vietnamese strain in 2005, but were distinct from the subcluster of recently distributing G1 strains widely in Asia including Okinawan strains and recent Lao strain in 2009. These clusters with own distinct distributions indicated involvements of different mechanisms and routes of spreading viruses and clarified that Australian G1 strain is from Southeast Asia, not from East Asia. Both Vientiane strains were antigenically close to P19-Br (G1, isolate, Thailand), but distinct from Nakayama (G3, prototype strain, Japan), Beijing-1 (G3, laboratory strain, China), and JaGAr#01 (G3, laboratory strain, Japan), demonstrated by cross-neutralization tests using polyclonal antisera. These results together with seroepidemiologic study conducted in Vientiane strongly suggest that diversified JEV cocirculated there in early 1990s

    Impact of Mild Paravalvular Regurgitation on Long- Term Clinical Outcomes After Transcatheter Aortic Valve Implantation

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    The impact of mild paravalvular regurgitation (PVR) after transcatheter aortic valve implantation (TAVI) remains controversial. We evaluated the impact of mild PVR after TAVI on long-term clinical outcomes. We included patients who underwent TAVI for severe symptomatic aortic stenosis between December 2008 and June 2019 at 2 interna-tional centers and compared all-cause death between the group with mild PVR (group 1) and the group with none or trace PVR (group 2). PVR was categorized using a 3-class grading scheme, and patients with PVR >= moderate and those who were lost to follow-up were excluded. This retrospective analysis included 1,404 patients (mean age 81.7 +/- 6.5 years, 58.0% women). Three hundred fifty eight patients (25.5%) were classified into group 1 and 1,046 patients (74.5%) into group 2. At baseline, group 1 was older and had a lower body mass index, worse co-morbidities, and more severe aortic stenosis. To account for these differences, propensity score matching was performed, resulting in 332 matched pairs. Within these matched groups, during a mean follow-up of 3.2 years, group 1 had a significantly lower survival rate at 5 years (group 1: 62.0% vs group 2: 68.0%, log-rank p = 0.029, hazard ratio: 1.41 [95% confidence interval: 1.04 to 1.91]). In the matched cohort, patients with mild PVR had a significant 1.4-fold increased risk of mortality at 5 years after TAVI compared with those with none or trace PVR. Further studies with more patients are needed to evaluate the impact of longer-term outcomes.(c) 2022 The Author(s). Published by Elsevier Inc. This is an open access article under the CC BY license (http://creativecommons.org/licenses/by/4.0/) (Am J Cardiol 2023;191:14-22)Peer reviewe

    Coordinated elevation of membrane type 1-matrix metalloproteinase and matrix metalloproteinase-2 expression in rat uterus during postpartum involution

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    BACKGROUND: The changes occurring in the rodent uterus after parturition can be used as a model of extensive tissue remodeling. As the uterus returns to its prepregnancy state, the involuting uterus undergoes a rapid reduction in size primarily due to the degradation of the extracellular matrix, particularly collagen. Membrane type-I matrix metalloproteinase (MT1-MMP) is one of the major proteinases that degrades collagen and is the most abundant MMP form in the uterus. Matrix metalloproteinase-2(MMP-2) can degrade type I collagen, although its main function is to degrade type IV collagen found in the basement membrane. To understand the expression patterns of matrix metalloproteinases (MMPs) in the rat uterus, we analyzed their activities in postpartum uterine involution. METHODS: We performed gelatin zymography, northern blot analysis and immunohistochemistry to compare the expression levels of MT1-MMP, MMP-2, matrix metalloproteinase-9 (MMP-9) and the tissue inhibitors of MMPs-1 and 2 (TIMP-1 and TIMP-2) in the rat uterus 18 h, 36 h and 5 days after parturition with their expression levels during pregnancy (day 20). RESULTS: We found that both MT1-MMP and MMP-2 localized mainly in the cytoplasm of uterine interstitial cells. The expression levels of MT1-MMP and MMP-2 mRNAs and the catalytic activities of the expressed proteins significantly increased 18 h and 36 h after parturition, but at postpartum day 5, their mRNA expression levels and catalytic activities decreased markedly. The expression levels of MMP-9 increased 18 h and 36 h after parturition as determined by gelatin zymography including the expression levels of TIMP-1 and TIMP-2. CONCLUSION: These expression patterns indicate that MT1-MMP, MMP-2, MMP-9, TIMP-1 and TIMP-2 may play key roles in uterine postpartum involution and subsequent functional regenerative processes
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