A precursory ULF signature for the Chi-Chi earthquake in Taiwan

ULF emission data at Lunping (epicentral distance, 120 km) have been analysed for the Chi-Chi earthquake (with magnitude 7.6 and depth of 11 km) in Taiwan which occurred on 21 September 1999. Simple intensity analyses have not yielded any significant results but we have found, based on the analysis of polarization (the ratio of vertical magnetic field component <i>Z</i> to the horizontal component <i>G</i>), that the polarization (<i>Z</i>/<i>G</i>) showed a significant enhancement for two months before the earthquake. This kind of temporal evolution of polarization seems to be very similar to previous results, so that it is highly likely that this phenomenon may be associated with the Chi-Chi earthquake. Also, the comparison of the results of polarization analyses, by changing the signal threshold, has given us an approximate intensity of the seismogenic emission of the order of the monthly mean value

Successful cessation of transmitting healthcare-associated infections due to Burkholderia cepacia complex in a neonatal intensive care unit in a Japanese children's hospital

<p>Abstract</p> <p>Background</p> <p><it>Burkholderia cepacia </it>strains have been known to possess the capability to cause serious infections especially in neonatal intensive care units (NICUs), and their multi-drug resistances become a severe threat in hospital settings. The aim of this investigation was to evaluate the <it>B. cepacia </it>complex infections in the NICU in Nagano Children's Hospital, Azumino 399-8288, Japan, and to report the intervention leading to the successful cessation of the outbreak.</p> <p>Methodology</p> <p>The incidence of isolation and antimicrobial susceptibilities of nosocomial <it>Burkholderia cepacia </it>complex strains during a four-year period were retrospectively examined by clinical microbiological records, and by pulsed-field gel electrophoresis analyses along with the bacteriological verification of disinfectant device itself and procedures for its maintenance routinely used in the NICU.</p> <p>Results</p> <p>During the period surveyed between 2007 and 2009, only an isolate per respective year of <it>B. cepacia </it>complex was recovered from each neonate in the NICU. However, in 2010, the successive 6 <it>B. cepacia </it>complex isolates were recovered from different hospitalized neonates. Among them, an isolate was originated from peripheral blood of a neonate, apparently giving rise to systemic infection. In addition, the hospitalized neonate with bacteremia due to <it>B. cepacia </it>complex also exhibited positive cultures from repeated catheterized urine samples together with tracheal aspirate secretions. However other 5 isolates were considered as the transients or contaminants having little to do with infections. Moreover, the 5 isolates between July and October in 2010 revealed completely the same electrophoresis patterns by means of pulsed-field gel electrophoresis analyses, strongly indicating that they were infected through the same medical practices, or by transmission of the same contaminant.</p> <p>Conclusions</p> <p>A small outbreak due to <it>B. cepacia </it>complex was brought about in the NICU in 2010, which appeared to be associated with the same genomovar of <it>B. cepacia </it>complex. The source or the rout of infection was unknown in spite of the repeated epidemiological investigation. It is noteworthy that no outbreak due to <it>B. cepacia </it>complex was noted in the NICU after extensive surveillance intervention.</p

Development of scanning x-ray fluorescence microscope with spatial resolution of 30 nm using Kirkpatrick-Baez mirror optics

We developed a high-spatial-resolution scanning x-ray fluorescence microscope (SXFM) using Kirkpatrick-Baez mirrors. As a result of two-dimensional focusing tests at BL29XUL of SPring-8, the full width at half maximum of the focused beam was achieved to be 50×30 nm2 (V×H) under the best focusing conditions. The measured beam profiles were in good agreement with simulated results. Moreover, beam size was controllable within the wide range of 30-1400 nm by changing the virtual source size, although photon flux and size were in a trade-off relationship. To demonstrate SXFM performance, a fine test chart fabricated using focused ion beam system was observed to determine the best spatial resolution. The element distribution inside a logo mark of SPring-8 in the test chart, which has a minimum linewidth of approximately 50-60 nm, was visualized with a spatial resolution better than 30 nm using the smallest focused x-ray beam. © 2006 American Institute of Physics.S. Matsuyama, H. Mimura, et al. "Development of scanning x-ray fluorescence microscope with spatial resolution of 30nm using Kirkpatrick-Baez mirror optics", Review of Scientific Instruments 77(10), 103102 (2006) https://doi.org/10.1063/1.2358699

Local Inhomogeneity Effects on Nucleation Process in a High External Bias

Quantum nucleation processes in the presence of local moderate inhomogeneities are studied theoretically at high biases. The quantum nucleation rate Gamma is calculated for one-dimensional systems in a form Gamma = A e^(-B/hbar) by using the `bounce' method. The bias-dependence of the exponent B is shown to be changed by inhomogeneities. This change is explained by the reduction of the effective spatial dimension of the system. By studying the system-size dependence of the prefactor A, the condition for the appearance of inhomogeneity effects is evaluated. Nucleation rates in thermal activation regimes are also calculated, and compared with quantum tunneling regimes. For higher-dimensional systems, it is shown that the local approximation of inhomogeneity does not hold, and that spatial profiles of inhomogeneity become important.Comment: 10 pages, 6 figure