Clay minerals from the tidal flat sediments along the coast of Youngjong Island, west of mainland Korea, were studied to ascertain their potential as an indicator of sea-level fluctuation. Semi-quantitative analysis of their clay-size fractions by XRD shows that the vertical distribution of clay minerals can be separated into four clay mineral assemblage units. Based on the relative contents of chlorite, four sedimentary units are distinguishable, and the abundance of chlorite is inversely related to that of smectite. The kaolinite content is constant, and so it is clear that chlorite originating from the Han River was transformed to smectite by pedogenesis during regression periods. Therefore, the relative contents of clay minerals from the unconsolidated materials in the tidal flat of Youngjong Island canbe used as indicators of transgression and regression in accordance with the sea-level fluctuation.

An attempt has been made to examine the nature of 3-minute umbral oscillations in order to identify their origin. For this purpose we have calculated, on the basis of Musielak and Rosner (1987), the fast-mode energy spectra generated in a typical sunspot convection zone (Yun 1968). The computed energy spectrum is fed into the lower boundary of the sub-photospheric resonant cavity to examine the characteristics of the wave propagation through the SS umbral atmosphere (Avrett 1981). The upward velocity spectra computed at various heights are presented and their behaviour compared with observations.

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.

We consider the dynamics of actively entraining turbulent density currents on a conical sloping surface in a rotating fluid. A theoretical plume model is developed to describe both axisymmetric flow and single-stream currents of finite angular extent. An analytical solution is derived for flow dominated by the initial buoyancy flux and with a constant entrainment ratio, which serves as an attractor for solutions with alternative initial conditions where the initial fluxes of mass and momentum are non-negligible. The solutions indicate that the downslope propagation of the current halts at a critical level where there is purely azimuthal flow, and the boundary layer approximation breaks down. Observations from a set of laboratory experiments are consistent with the dynamics predicted by the model, with the flow approaching a critical level. Interpretation in terms of the theory yields an entrainment coefficient $E\propto 1/\Omega $ where the rotation rate is $\Omega $ . We also derive a corresponding theory for density currents from a line source of buoyancy on a planar slope. Our theoretical models provide a framework for designing and interpreting laboratory studies of turbulent entrainment in rotating dense flows on slopes and understanding their implications in geophysical flows.

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.

A tournamentTn consists of a finite set of nodes1, 2, …, n such that each pair of distinct nodes i and j is joined by exactly one of the arcsij or ji. If the arc ij is in Tn we say that i beats j or j loses to i and write i→j. If each node of a subtournament A beats each node of a subtournament B we write A→B and let A + B denote the tournament determined by the nodes of A and B.

Cryptosporidium parvum is an intracellular protozoan parasite that causes cryptosporidiosis in mammals including humans. In the current study, the gene encoding the cysteine protease of C. parvum (cryptopain-1) was identified and the biochemical properties of the recombinant enzyme were characterized. Cryptopain-1 shared common structural properties with cathepsin L-like papain family enzymes, but lacked a typical signal peptide sequence and contained a possible transmembrane domain near the amino terminus and a unique insert in the front of the mature domain. The recombinant cryptopain-1 expressed in Escherichia coli and refolded to the active form showed typical biochemical properties of cathepsin L-like enzymes. The folding determinant of cryptopain-1 was characterized through multiple constructs with or without different lengths of the pro-domain of the enzyme expressed in E. coli and assessment of their refolding abilities. All constructs, except one that did not contain the full-length mature domain, successfully refolded into the active enzymes, suggesting that cryptopain-1 did not require the pro-domain for folding. Western blot analysis showed that cryptopain-1 was expressed in the sporozoites and the enzyme preferentially degraded proteins, including collagen and fibronectin, but not globular proteins. This suggested a probable role for cryptopain-1 in host cell invasion and/or egression by the parasite.

Summary

Background and objective: Since reports have shown that outpatient preoperative evaluation increases the quality of care and cost-effectiveness, an increasing number of patients are being evaluated purely on an outpatient basis. To improve cost-effectiveness, it would be appealing if those patients who are healthy and ready for surgery without additional testing could be easily distinguished from those who require more extensive evaluation. This paper examines whether published studies provide sufficient data to determine how detailed preoperative history taking and physical examination need to be in order to assess the health of surgical patients and to meet the objective of easy and early distinction.

Methods: A MEDLINE search was conducted from 1991 to 2000 with respect to preoperative patient history and physical examination. Altogether, 213 articles were found, of which 29 were selected. Additionally, 38 cross-references, 7 articles on additional testing and 4 recently published papers were used.

Results: It is questionable to what extent an extensive history is relevant for anaesthesia and long-term prognosis. With respect to physical examination, it seems unreasonable to diagnose valvular heart disease based on cardiac auscultation only, and it is unclear which method should be used to predict the difficulty of endotracheal intubation. The benefits of routine testing for all surgical patients before operation are extremely limited and are not advocated.

Conclusions: The amount of detail of preoperative patient history and the value of physical examination to obtain a reasonable estimate of perioperative risk remains unclear. Although not evidence based, a thorough history taking and physical examination of all patients before surgery seems important until more evidence-based guidelines become available. Diagnostic and prognostic prediction studies may provide this necessary evidence.

Transmission electron microscopy (TEM) was utilized to investigate microstructures of heteroepitaxial SiC/Si films, grown from single-source precursors such as tetramethylsilane [TMS, Si(CH3)4], hexamethyldisilane [HMDS, Si2(CH3)6], and 1,3-disilabutane [1,3-DSB, H3SiCH2SiH2CH3]. In the case of TMS/H2 and HMDS/H2 samples, SiC/Si films grown at relatively high precursor concentration and/or low temperatures showed columnar grains with a high degree of epitaxial relationship with the Si substrate. Higher quality films with larger grains were observed in the case of high temperature and/or low precursor concentration samples, although a high density of interfacial voids was observed. Samples grown from pure 1,3-DSB at a low pressure showed high quality single crystalline films with few interfacial voids. It was suggested that the microstructural behavior of these films closely resembles that of the SiC films formed during the carbonization of Si surfaces by the pyrolysis of hydrocarbons, in which the nucleation rate of the film at the initial stage plays a key role. The improvement achieved during the 1,3-DSB growth is proposed to be due to the low growth pressure and the 1 : 1 ratio of Si and C associated with this precursor.

A novel methodology has been developed for the preparation of amorphous semiconductor samples for use in transmission extended x-ray absorption fine structure (EXAFS) measurements. Epitaxial heterostructures were fabricated by metal organic chemical vapour deposition (group III-Vs) or molecular beam epitaxy (group IVs). An epitaxial layer of ∼2 μm thickness was separated from the underlying substrate by selective chemical etching of an intermediate sacrificial layer. Ion implantation was utilised to amorphise the epitaxial layer either before or after selective chemical etching. The resulting samples were both stoichiometric and homogeneous in contrast to those produced by conventional techniques. The fabrication of amorphous GaAs, InP, In0.53Ga0.47As and SixGe1-x samples is described. Furthermore, EXAFS measurements comparing both fluorescence and transmission detection, and crystalline and amorphised GaAs, are shown.

The fabrication and characterization of polyaniline (PANI) derivatives deposited on ITO coated glass is investigated as possible hole injection layers for MEH-PPV based polymer light emitting diode (PLED) devices. This involved multilayer ordering by the alternate polyelectrolyte adsorption of polyaniline and sulfonated poyaniline with an oppositely charged polyelectrolyte from solution. A combination of spectroscopic and microscopic techniques was utilized to determine the layer ordering, film structure, morphology, and homogeneity. The deposition process generally showed a linear behavior for all pairs as shown by ellipsometry and UV-vis spectroscopy. However, surface plasmon spectroscopy (SPS) and AFM revealed that thicker films are accompanied by increased surface roughness regardless of concentration. Comparison in performance was made between bare ITO and PANI or SPANI coated devices. Initial investigations of PLED performance showed significant improvements in lifetime and efficiency compared to bare ITO.

To lower the temperature of oxide-passivation processing the high- purity ozone (more than 98 mole %) was used instead of usual thermal oxidation. Initial oxide formation on a Si(111) surface with high-purity ozone is investigated by X-ray photoelectron spectroscopy (XPS). From the comparison of the suboxides formed with ozone and oxygen exposures, it is clear that ozone forms less suboxide than oxygen. The oxidation with ozone also proceeds on the hydrogen passivated surface which oxygen molecules do not oxidize.