145 research outputs found

    Financial Restraints in the South Korean Miracle

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    We provide novel empirical evidence on the effects of financial restraints on South Korean financial development. The evidence is linked to a simple model of the Korean banking system that encapsulates its cartelised nature, which predicts a positive association between financial development and (i) the degree of state control over the banking system, (ii) mild repression of lending rates. The model also predicts that in the presence of lending rate controls, increases in the level of the administered deposit rate are unlikely to influence financial deepening. We test the model empirically by constructing individual and summary measures of financial restraints. Our empirical findings are consistent with our theoretical predictions but contrast sharply with the predictions of earlier literature that postulates that interest rate ceilings and other financial restraints constitute sources of ‘financial repression’.Financial deepening; financial restraints

    Emerging applications of high temperature superconductors for space communications

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    Proposed space missions require longevity of communications system components, high input power levels, and high speed digital logic devices. The complexity of these missions calls for a high data bandwidth capacity. Incorporation of high temperature superconducting (HTS) thin films into some of these communications system components may provide a means of meeting these requirements. Space applications of superconducting technology has previously been limited by the requirement of cooling to near liquid helium temperatures. Development of HTS materials with transition temperatures above 77 K along with the natural cooling ability of space suggest that space applications may lead the way in the applications of high temperature superconductivity. In order for HTS materials to be incorporated into microwave and millimeter wave devices, the material properties such as electrical conductivity, current density, surface resistivity and others as a function of temperature and frequency must be well characterized and understood. The millimeter wave conductivity and surface resistivity were well characterized, and at 77 K are better than copper. Basic microwave circuits such as ring resonators were used to determine transmission line losses. Higher Q values than those of gold resonator circuits were observed below the transition temperature. Several key HTS circuits including filters, oscillators, phase shifters and phased array antenna feeds are feasible in the near future. For technology to improve further, good quality, large area films must be reproducibly grown on low dielectric constant, low loss microwave substrates

    Measurements of complex permittivity of microwave substrates in the 20 to 300 K temperature range from 26.5 to 40.0 GHz

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    A knowledge of the dielectric properties of microwave substrates at low temperatures is useful in the design of superconducting microwave circuits. Results are reported for a study of the complex permittivity of sapphire (Al2O3), magnesium oxide (MgO), silicon oxide (SiO2), lanthanum aluminate (LaAlO3), and zirconium oxide (ZrO2), in the 20 to 300 Kelvin temperature range, at frequencies from 26.5 to 40.0 GHz. The values of the real and imaginary parts of the complex permittivity were obtained from the scattering parameters, which were measured using a HP-8510 automatic network analyzer. For these measurements, the samples were mounted on the cold head of a helium gas closed cycle refrigerator, in a specially designed vacuum chamber. An arrangement of wave guides, with mica windows, was used to connect the cooling system to the network analyzer. A decrease in the value of the real part of the complex permittivity of these substrates, with decreasing temperature, was observed. For MgO and Al2O3, the decrease from room temperature to 20 K was of 7 and 15 percent, respectively. For LaAlO3, it decreased by 14 percent, for ZrO2 by 15 percent, and for SiO2 by 2 percent, in the above mentioned temperature range

    NASA Space applications of high-temperature superconductors

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    The application of superconducting technology in space has been limited by the requirement of cooling to near liquid helium temperatures. The only means of obtaining these temperatures has been with cryogenic fluids which severely limit mission lifetime. The development of materials with superconducting transition temperatures above 77 K has made superconducting technology more attractive and feasible for employment in aerospace systems. Here, potential applications of high temperature superconducting technology in cryocoolers, remote sensing, communications, and power systems are discussed

    Use of Inhaled Iloprost in an Infant With Bronchopulmonary Dysplasia and Pulmonary Artery Hypertension

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    Pulmonary artery hypertension is a common cardiovascular complication in preterm infants with bronchopulmonary dysplasia which is associated with increased morbidity and mortality. Inhaled iloprost is used as a therapeutic option in pulmonary hypertension, especially in adults. There have been but a few reports on the use of iloprost for neonates and infants. We report the case of a 5 month-old-male infant who received neonatal intensive care for 4 months due to respiratory distress syndrome and prematurity, during which he developed bronchopulmonary dysplasia. Echocardiography showed severe pulmonary hypertension. The initial treatment included respiratory support with high frequency oscillatory ventilation (HFOV); however, his clinical condition did not improve. Inhaled iloprost with sildenafil, an oral phosphodiesterase-5 inhibitor, was thus used. With the administration of iloprost and sildenafil, his condition improved and he was weaned from oxygen. Our clinical experience suggests that iloprost is a promising therapy for pulmonary hypertension, especially when inhaled nitric oxide is unavailable

    The association of anti-CCP antibodies with disease activity in rheumatoid arthritis

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    Antibodies to citrullinated proteins have been described in patients with rheumatoid arthritis (RA) and these appear to be the most specific markers of the disease. Our objective was to determine the frequency of antibodies to cyclic citrullinated peptides (CCPs) in patients with RA and the association of anti-CCP antibodies with disease activity, radiological erosions and HLA DR genotype. Forty patients with RA and 38 patients with fibromyalgia were included in this study. Serum samples were collected from both patient groups with RA and fibromyalgia. Anti-CCP was measured by the corresponding enzyme-linked immunosorbent assay. Additionally, erythrocyte sedimentation rate (ESR), C-reactive protein (CRP), rheumatoid factor (RF), disease activity score (DAS), visual analog scala (VAS), HLA genotype and radiographic information were determined in patients with RA. The rate of sensitivity and specificity of anti-CCP reactivity for the diagnosis RA were measured (sensitivity 50%, specificity100%). There is no significant difference between anti-CCP (+) and anti-CCP (−) RA patients for DAS28, VAS, ESR, CRP, disease duration, HLA genotype, and radiological assessment of hand. However, there was a significant difference between anti-CCP (+) and anti-CCP (−) RA patients for RF and the radiological assessment of left and right wrists (respectively, P < 0.05, P = 0.04, P = 0.01). There was no significant correlation between anti-CCP antibody and ESR, CRP, VAS, DAS 28 or radiological assessment. A small but significant correlation was found between RF and anti-CCP antibody (P = 0.02, r = 0.35)

    Control of the induction of type I interferon by Peste des petits ruminants virus.

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    Peste des petits ruminants virus (PPRV) is a morbillivirus that produces clinical disease in goats and sheep. We have studied the induction of interferon-β (IFN-β) following infection of cultured cells with wild-type and vaccine strains of PPRV, and the effects of such infection with PPRV on the induction of IFN-β through both MDA-5 and RIG-I mediated pathways. Using both reporter assays and direct measurement of IFN-β mRNA, we have found that PPRV infection induces IFN-β only weakly and transiently, and the virus can actively block the induction of IFN-β. We have also generated mutant PPRV that lack expression of either of the viral accessory proteins (V&C) to characterize the role of these proteins in IFN-β induction during virus infection. Both PPRV_ΔV and PPRV_ΔC were defective in growth in cell culture, although in different ways. While the PPRV V protein bound to MDA-5 and, to a lesser extent, RIG-I, and over-expression of the V protein inhibited both IFN-β induction pathways, PPRV lacking V protein expression can still block IFN-β induction. In contrast, PPRV C bound to neither MDA-5 nor RIG-I, but PPRV lacking C protein expression lost the ability to block both MDA-5 and RIG-I mediated activation of IFN-β. These results shed new light on the inhibition of the induction of IFN-β by PPRV
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