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A large literature has established that the International Monetary Fund (IMF) is heavily politicized. We argue that this politicization has important consequences for international reserve accumulation and financial crises. The IMF generates moral hazard asymmetrically, reducing the expected costs of risky lending and policies for states that are politically influential vis-à-vis the institution. Using a panel data set covering 1980 to 2010, we show that proxies for political influence over the IMF are associated with outcomes indicative of moral hazard: lower international reserves and more frequent financial crises. We support our causal claims by applying the synthetic control method to Taiwan, which was expelled from the IMF in 1980. Consistent with our predictions, Taiwan's expulsion led to a sharp increase in precautionary international reserves and exceptionally conservative financial policies.
Macrosomia, not only is closely associated with short-term, birth-related problems, but also has long-term consequences for the offspring. We investigated the expression of long non-coding RNAs (lncRNAs) and messenger RNAs (mRNAs) in the placenta of macrosomia births using a microarray profile. The data showed that 2929 lncRNAs and 4574 mRNAs were upregulated in the placenta of macrosomia births compared with the normal birth weight group (fold change ⩾2.0, P<0.05), and 2127 lncRNAs and 2511 mRNAs were downregulated (fold change ⩾2.0, P<0.05). To detect the function of the differentially expressed lncRNAs and their possible relationship with the differentially expressed mRNAs, we also performed gene ontology analysis and pathway analysis. The results demonstrated that the PI3K-AKT signalling pathway, the mitogen-activated protein kinase (MAPK) signalling pathway, the focal adhesion pathway, the B cell receptor signalling pathway, and the protein processing in endoplasmic reticulum and lysosome pathway were significantly differentially expressed in the macrosomia placenta. Four lncRNAs were randomly chosen from the differentially expressed lncRNAs to validate the microarray data by quantitative polymerase chain reaction (qPCR). The qPCR results were consistent with the microarray data. In conclusion, lncRNAs were significantly differentially expressed in the placenta of macrosomia patients, and may contribute to the pathogenesis of macrosomia.
Generally, pylon-mounted external stores significantly affect the aerodynamic characteristics of the aircraft due to their flexibility. Therefore, many investigations upon the dynamic and aeroelastic characteristics of an aircraft wing with external stores have been done over the last few decades Recently, a study was carried out regarding the aeroelastic effects on wings by the engine placement For severe operation conditions, classical linear theory with a small amount of amplitude vibration may not be an appropriate analysis. Nonlinear vibration analysis will be required, especially when the amplitude of the vibration is larger than the wing thickness. Chia performed static, dynamic, and post-buckling analyses of various isotropic and composite plates for that purpose. Dumir and Bhaskar derived finite element formulations to analyse the nonlinear vibration of beams and plates. Moreover, the variational-asymptotic plate formulation and the accompanying equations for the global analysis for the plates have been studied. That approach accounted every possible geometrical non-linearity associated with large displacement and small strain.
After an outbreak of pandemic influenza A/H1N1 (pH1N1) virus, we had previously reported the emergence of a recombinant canine influenza virus (CIV) between the pH1N1 virus and the classic H3N2 CIV. Our ongoing routine surveillance isolated another reassortant H3N2 CIV carrying the matrix gene of the pH1N1 virus from 2012. The infection dynamics of this H3N2 CIV variant (CIV/H3N2mv) were investigated in dogs and ferrets via experimental infection and transmission. The CIV/H3N2mv-infected dogs and ferrets produced typical symptoms of respiratory disease, virus shedding, seroconversion, and direct-contact transmissions. Although indirect exposure was not presented for ferrets, CIV/H3N2mv presented higher viral replication in MDCK cells and more efficient transmission was observed in ferrets compared to classic CIV H3N2. This study demonstrates the effect of reassortment of the M gene of pH1N1 in CIV H3N2.
Equine influenza virus (EIV) causes a highly contagious respiratory disease in equids, with confirmed outbreaks in Europe, America, North Africa, and Asia. Although China, Mongolia, and Japan have reported equine influenza outbreaks, Korea has not. Since 2011, we have conducted a routine surveillance programme to detect EIV at domestic stud farms, and isolated H3N8 EIV from horses showing respiratory disease symptoms. Here, we characterized the genetic and biological properties of this novel Korean H3N8 EIV isolate. This H3N8 EIV isolate belongs to the Florida sublineage clade 1 of the American H3N8 EIV lineage, and surprisingly, possessed a non-structural protein (NS) gene segment, where 23 bases of the NS1-encoding region were naturally truncated. Our preliminary biological data indicated that this truncation did not affect virus replication; its effect on biological and immunological properties of the virus will require further study.
The purpose of this study was to analyze the expression of the placenta-specific microRNA miR-517a in maternal serum and in placental tissue from low birth weight newborns and try to detect the effects of miR-517a expression on invasion potential of trophoblasts. Placental tissue and maternal serum were collected from both low birth weight newborns (n = 10) and normal birth weight newborns (n = 20). Expression of miR-517a was assessed in placenta and serum samples by real-time qRT-PCR. In addition, human trophoblast HTR8/SVneo cells were transfected with a miR-517a 2′-O-methyl oligonucleotide or a negative control RNA, and invasion was measured using transwell migration assays. Expression of miR-517a was significantly increased in placentas from low birth weight newborns (61.79 ± 23.06) in comparison with those of normal birth weight newborns (5.01 ± 1.97; P < 0.05). The expression of miR-517a was also increased in maternal serum isolated from the low birth weight newborn (25.78 ± 8.69) compared with the normal birth weight newborn (3.21 ± 1.07; P < 0.05). Overexpression of miR-517a significantly inhibited invasion of HTR8/SVneo cells (P < 0.05). These data indicate that miR-517a overexpression could potentially lead to low birth weight, likely through the inhibition of trophoblast invasion.
The Ultra-Fast Flash Observatory (UFFO), which will be launched onboard theLomonosov spacecraft, contains two crucial instruments: UFFO BurstAlert & Trigger Telescope (UBAT) for detection and localization of Gamma-Ray Bursts(GRBs) and the fast-response Slewing Mirror Telescope (SMT) designed for the observationof the prompt optical/UV counterparts. Here we discuss the in-space calibrations of theUBAT detector and SMT telescope. After the launch, the observations of the standard X-raysources such as pulsar in Crab nebula will provide data for necessary calibrations ofUBAT. Several standard stars will be used for the photometric calibration of SMT. Thecelestial X-ray sources, e.g. X-ray binaries with bright optical sourcesin their close angular vicinity will serve for the cross-calibration of UBAT and SMT.
The Ultra-Fast Flash Observatory (UFFO) Pathfinder for Gamma-Ray Bursts (GRBs) consistsof two telescopes. The UFFO Burst Alert & Trigger Telescope (UBAT) handles thedetection and localization of GRBs, and the Slewing Mirror Telescope (SMT) conducts themeasurement of the UV/optical afterglow. UBAT is equipped with an X-ray detector, analogand digital signal readout electronics that detects X-rays from GRBs and determines thelocation. SMT is equipped with a stepping motor and the associated electronics to rotatethe slewing mirror targeting the GRBs identified by UBAT. First the slewing mirror pointsto a GRB, then SMT obtains the optical image of the GRB using the intensified CCD and itsreadout electronics. The UFFO Data Acquisition system (UDAQ) is responsible for theoverall function and operation of the observatory and the communication with the satellitemain processor. In this paper we present the design and implementation of the electronicsof UBAT and SMT as well as the architecture and implementation of UDAQ.
The UFFO (Ultra-Fast Flash Observatory) is a GRB detector on board the Lomonosovsatellite, to be launched in 2013. The GRB trigger is provided by an X-ray detector,called UBAT (UFFO Burst Alarm & Trigger Telescope), which detects X-rays from the GRBand then triggers to determine the direction of the GRB and then alerts the Slewing MirrorTelescope (SMT) to turn in the direction of the GRB and record the optical photon fluxes.This report details the calibration of the two components: the MAPMTs and the YSO crystalsand simulations of the UBAT. The results shows that this design can observe a GRB within afield of view of ±35° and can trigger in a time scale as short as 0.2 – 1.0 safter the appearance of a GRB X-ray spike.
The Ultra-Fast Flash Observatory (UFFO) is a space observatory for optical follow-ups ofgamma ray bursts (GRBs), aiming to explore the first 60 seconds of GRBs optical emission.UFFO is utilized to catch early optical emissions from GRBs within few sec after triggerusing a Gimbal mirror which redirects the optical path rather than slewing entirespacecraft. We have developed a 15 cm two-axis Gimbal mirror stage for the UFFO-Pathfinderwhich is going to be on board the Lomonosov satellite which is to be launched in 2013. Thestage is designed for fast and accurate motion with given budgets of 3 kg of mass and 3Watt of power. By employing stepping motors, the slewing mirror can rotate faster than 15deg/sec so that objects in the UFFO coverage (60 deg × 60 deg) can be targeted in~1 sec. The obtained targeting resolution is better 2 arcmin using a close-loopcontrol with high precision rotary encoder. In this presentation, we will discuss detailsof design, manufacturing, space qualification tests, as well as performance tests.
The Ultra-Fast Flash Observatory (UFFO) is a space mission to detect the early moments of an explosion from Gamma-ray bursts (GRBs), thus enhancing our understanding of the GRB mechanism. It consists of the UFFO Burst & Trigger telescope (UBAT) for the recognition of GRB positions using hard X-ray from GRBs. It also contains the Slewing Mirror Telescope (SMT) for the fast detection of UV-optical photons from GRBs. It is designed to begin the UV-optical observations in less than a few seconds after the trigger. The UBAT is based on a coded-mask X-ray camera with a wide field of view (FOV) and is composed of the coded mask, a hopper and a detector module. The SMT has a fast rotatable mirror which allows a fast UV-optical detection after the trigger. The telescope is a modified Ritchey-Chrétien telescope with the aperture size of 10 cm diameter, and an image intensifier readout by CCD. The UFFO pathfinder is scheduled to launch into orbit on 2012 June by the Lomonosov spacecraft. It is a scaled-down version of UFFO in order to make the first systematic study of early UV/optical light curves, including the rise phase of GRBs. We expect UBAT to trigger ~44 GRBs/yr and expect SMT to detect ~10 GRBs/yr.
Surveillance is an important component of influenza control. This report describes the establishment and first results of the Korean Influenza Surveillance Scheme (KISS), an integrated clinical and laboratory surveillance network involving 622 public health centres (PHCs) and private clinics. Sentinel physicians reported cases of influenza-like illness (ILI) weekly and forwarded specimens for virus isolation and characterization. Influenza activity during the opening 2000–2001 season was milder and delayed compared with previous years. The ILI consultation rate corresponded well with the number of influenza virus isolates, both peaking in week 10 of 2001. Influenza A(H3N2) was the dominant isolate. The peak ILI consultation rate was higher in private clinics than in PHCs (5·04 vs 1·79 cases/1000 visits). An evaluation questionnaire generated potential enhancements to the scheme. KISS appears to represent the pattern of influenza activity accurately and will have a valuable role in monitoring and preventing epidemics in Korea.
We formulate a global equilibrium model to describe the growth of 1-d nanostructures in the VLS process by including also the chemical tension in addition to the physical tensions. The chemical tension derives from the Gibbs free energy release due to the growth of a crystal layer. The system global equilibrium is attained via the balance of the static physical tensions and the dynamic chemical tension, which allows the system to reach the minimum Gibbs free energy state. The model predicts, and provides conditions for the growth of nanowires of all sizes exceeding a lower thermodynamic limit. The model also predicts the conditions distinguishing the growth of nanaohillocks from nanowires.
It is well known that Au indiffusion in Si is dominated by the Kick-Out mechanism governed by Si self-interstitials, with negligible contribution from the Frank-Turnbull mechanism governed by vacancies. In this paper we present modeling and simulation results to show that the Frank-Turnbull mechanism actually dominates Au outdiffusion in Si.
Cyst fluid (CF) of Taenia solium metacestode (TsM) is an important source of serodiagnostic antigens. We have investigated the molecular characteristics of the 120 kDa protein complex in TsM CF purified by fast performance liquid chromatography. The structure of the purified protein was characterized by a variety of proteomic analyses. The protein was found to consist of 2 major components of 42–46 and 22–28 kDa, and shared 3 subunits of 14, 16 and 18 kDa. The 42–46 kDa component was determined to contain 3 additional subunits of 22, 28 and 38 kDa. These 6 subunits were shown to originate from either the 14 or 18 kDa precursor. We assessed the antibody reactivity of the native protein, its individual subunits and the recombinant 14 and 18 kDa proteins, and found that the 120 kDa protein, particularly 14 and 18 kDa subunits revealed high reliability for differentiation of active and mixed stage NC from chronic NC. The subunits of the 120 kDa protein complex identified herein represent some of the low-molecular weight glycoproteins which have been described in several previous studies. Recognizing and understanding the structural and immunological relationship of these proteins will facilitate the development of new serodiagnostic assays.
A copper/zinc superoxide dismutase (Cu/ZnSOD) gene and a manganese superoxide dismutase (MnSOD) gene of the human parasite Clonorchis sinensis have been cloned and their gene products functionally characterized. Genes Cu/ZnSOD and MnSOD encode proteins of 16 kDa and 25·4 kDa, respectively. The deduced amino acid sequences of the two genes contained highly conserved residues required for activity and secondary structure formation of Cu/ZnSOD and MnSOD, respectively, and show up to 73·7% and 75·4% identities with their counterparts in other animals. The genomic DNA sequence analysis of Cu/ZnSOD gene revealed this as an intronless gene. Inhibitor studies with purified recombinant Cu/ZnSOD and MnSOD, both of which were functionally expressed in Escherichia coli, confirmed that they are copper/zinc and manganese-containing SOD, respectively. Immunoblots showed that both C. sinensis Cu/ZnSOD and MnSOD should be antigenic for humans, and both, especially the C. sinensis MnSOD, exhibit extensive cross-reactions with sera of patients infected by other trematodes or cestodes. RT-PCR and SOD activity staining of parasite lysates indicate that there are no significant differences in mRNA level or SOD activity for both species of SOD, indicating cytosolic Cu/ZnSOD and MnSOD might play a comparatively important role in the C. sinensis antioxidant system.
A separated turbulent boundary layer over a flat plate was investigated by direct numerical simulation of the incompressible Navier–Stokes equations. A suction-blowing velocity distribution was prescribed along the upper boundary of the computational domain to create an adverse-to-favourable pressure gradient that produces a closed separation bubble. The Reynolds number based on inlet free-stream velocity and momentum thickness is 300. Neither instantaneous detachment nor reattachment points are fixed in space but fluctuate significantly. The mean detachment and reattachment locations determined by three different definitions, i.e. (i) location of 50% forward flow fraction, (ii) mean dividing streamline (ψ=0), (iii) location of zero wall-shear stress (τw=0), are in good agreement. Instantaneous vorticity contours show that the turbulent structures emanating upstream of separation move upwards into the shear layer in the detachment region and then turn around the bubble. The locations of the maximum turbulence intensities as well as Reynolds shear stress occur in the middle of the shear layer. In the detached flow region, Reynolds shear stresses and their gradients are large away from the wall and thus the largest pressure fluctuations are in the middle of the shear layer. Iso-surfaces of negative pressure fluctuations which correspond to the core region of the vortices show that large-scale structures grow in the shear layer and agglomerate. They then impinge on the wall and subsequently convect downstream. The characteristic Strouhal number St=fδ*in/U0 associated with this motion ranges from 0.0025 to 0.01. The kinetic energy budget in the detachment region is very similar to that of a plane mixing layer.
Space–time correlations and frequency spectra of wall-pressure fluctuations, obtained from direct numerical simulation, are examined to reveal the effects of pressure gradient and separation on the characteristics of wall-pressure fluctuations. In the attached boundary layer subjected to adverse pressure gradient, contours of constant two-point spatial correlation of wall-pressure fluctuations are more elongated in the spanwise direction. Convection velocities of wall-pressure fluctuations as a function of spatial and temporal separations are reduced by the adverse pressure gradient. In the separated turbulent boundary layer, wall-pressure fluctuations are reduced inside the separation bubble, and enhanced downstream of the reattachment region where maximum Reynolds stresses occur. Inside the separation bubble, the frequency spectra of wall-pressure fluctuations normalized by the local maximum Reynolds shear stress correlate well compared to those normalized by free-stream dynamic pressure, indicating that local Reynolds shear stress has more direct influence on the wall-pressure spectra. Contour plots of two-point correlation of wall-pressure fluctuations are highly elongated in the spanwise direction inside the separation bubble, implying the presence of large two-dimensional roller-type structures. The convection velocity determined from the space–time correlation of wall-pressure fluctuations is as low as 0.33U0 (U0 is the maximum inlet velocity) in the separated zone, and increases downstream of reattachment.
This work extends the study of the structure of wall-bounded flows using the topological properties of eddying motions as developed by Chong et al. (1990), Soria et al. (1992, 1994), and as recently extended by Blackburn et al. (1996) and Chacin et al. (1996). In these works, regions of flow which are focal in nature are identified by being enclosed by an isosurface of a positive small value of the discriminant of the velocity gradient tensor. These regions resemble the attached vortex loops suggested first by Theodorsen (1955). Such loops are incorporated in the attached-eddy model versions of Perry & Chong (1982), Perry et al. (1986), and Perry & Marusic (1995), which are extensions of a model first formulated by Townsend (1976). The direct numerical simulation (DNS) data of wall-bounded flows studied here are from the zero-pressure-gradient flow of Spalart (1988) and the boundary layer with separation and reattachment of Na & Moin (1996). The flow structures are examined from the viewpoint of the attached eddy hypothesis.