Effects of 6-O-Methylglucose-Containing Lipopolysaccharides on the Activity of Fatty Acid Elongation Systems in Mycobacterium Smeamatis

Among four species of 6-O-methylglucose-containing lipopolysaccharides (MGLP)1,2) of Mycobacterium smegmatis, MGLP-I, which lacks succinyl residues, and MGLP-II, which contains one mol of succinyl residue per mol of MGLP, inhibited the activity of the acyl carrier protein (ACP)-dependent fatty acid elongation system (FAS-II)3) prepared from the same bacilli by ammonium sulfate precipitations and gel filtration of Sephacryl S-200. When the molar ratio of palmitoyl-CoA to MGLP-II was 1:1, the FAS-II activity was reduced to about 70% of the normal value. When it was 1:3, the activity was about 30%. MGLP-I, on the other hand, inhibited the activity of partially purified palmitoyl-CoA -ACP transacylase, which is one of enzymes of FAS-II. In addition, it also inhibited the activity of the acetyl-CoA-dependent fatty acid elongation system (FES-I)4) when the concentration of decanoyl-CoA used as the optimum primer was lower than its 2 Km value and the activity of the malonyl-CoA-dependent fatty acid elongation system (FES-II)5) when the concentration of stearoyl-CoA used as optimum primer was lower than 50μ-M (the standard concentration of the original assay). The physiological role of these lipopolysaccharides on the mycobacterial lipid metabolism was discussed

An Analysis Of Bottleneck Technology By Using Experiments And CAE -Example Of The Automotive Transaxle Oil Seal Leakage-

This research aims to clarify the technological mechanism by using experiment and CAE (Computer Aided Engineering). Concretely, we take up the automotive transaxle oil seal leakage. To clarify an unknown mechanism, the dynamic behavior on the surface of the seal lip in the drive shaft high-speed rotation was observed with the visualization device. The authors thus achieved the desired results

X-ray Measurements of the Particle Acceleration Properties at Inward Shocks in Cassiopeia A

We present new evidence that the bright non-thermal X-ray emission features in the interior of the Cassiopeia A supernova remnant (SNR) are caused by inward moving shocks based on Chandra and NuSTAR observations. Several bright inward-moving filaments were identified using monitoring data taken by Chandra in 2000-2014. These inward-moving shock locations are nearly coincident with hard X-ray (15-40 keV) hot spots seen by NuSTAR. From proper motion measurements, the transverse velocities were estimated to be in the range $\sim$2,100-3,800 km s$^{-1}$ for a distance of 3.4 kpc. The shock velocities in the frame of the expanding ejecta reach values of $\sim$5,100-8,700 km s$^{-1}$, slightly higher than the typical speed of the forward shock. Additionally, we find flux variations (both increasing and decreasing) on timescales of a few years in some of the inward-moving shock filaments. The rapid variability timescales are consistent with an amplified magnetic field of $B \sim$ 0.5-1 mG. The high speed and low photon cut-off energy of the inward-moving shocks are shown to imply a particle diffusion coefficient that departs from the Bohm regime ($k_0 = D_0/D_{\rm 0,Bohm} \sim$ 3-8) for the few simple physical configurations we consider in this study. The maximum electron energy at these shocks is estimated to be $\sim$8-11 TeV, smaller than the values of $\sim$15-34 TeV inferred for the forward shock. Cassiopeia A is dynamically too young for its reverse shock to appear to be moving inward in the observer frame. We propose instead that the inward-moving shocks are a consequence of the forward shock encountering a density jump of $\gtrsim$ 5-8 in the surrounding material.Comment: 16 pages, 8 figures, accepted for publication in Ap

Suzaku Observation of Group of Galaxies NGC 507: Temperature and Metal Distributions in the Intra-cluster Medium

Temperature and abundance distributions of the intra-cluster medium (ICM) in the NGC 507 group of galaxies were studied with Suzaku. Observed concentric annular spectra were well-represented by a two temperature model for ICM, and we found steeper abundance gradients for Mg, Si, S, and Fe compared with O in the central region. Abundance ratios of alpha-elements to iron were found to be similar to those in other groups and poor clusters. We calculated metal mass-to-light ratios for Fe, O and Mg (IMLR, OMLR, MMLR) for NGC 507, and values for different systems were compared. Hotter and richer systems tend to show higher values of IMLR, OMLR, and MMLR. OMLR and MMLR were measured to an outer region for the first time with Suzaku, while IMLR was consistent with that with ASCA. We also looked into 2-dimensional map of the hardness ratio, but found no significant deviation from the circular symmetry.Comment: 12 pages, 10 figures, accepted for publication in PAS

Eisenhart Lift of 22--Dimensional Mechanics

The Eisenhart lift is a variant of geometrization of classical mechanics with $d$ degrees of freedom in which the equations of motion are embedded into the geodesic equations of a Brinkmann-type metric defined on $(d+2)$-dimensional spacetime of Lorentzian signature. In this work, the Eisenhart lift of $2$-dimensional mechanics on curved background is studied. The corresponding $4$-dimensional metric is governed by two scalar functions which are just the conformal factor and the potential of the original dynamical system. We derive a conformal symmetry and a corresponding quadratic integral, associated with the Eisenhart lift. The energy--momentum tensor is constructed which, along with the metric, provides a solution to the Einstein equations. Uplifts of $2$-dimensional superintegrable models are discussed with a particular emphasis on the issue of hidden symmetries. It is shown that for the $2$-dimensional Darboux--Koenigs metrics, only type I can result in Eisenhart lifts which satisfy the weak energy condition. However, some physically viable metrics with hidden symmetries are presented.Comment: 20 page

Transmission electron microscopy study on FeSi₂ nanoparticles synthesized by electron-beam evaporation

We have synthesized epitaxially grown iron disilicide (FeSi₂) nanoparticles using an electron-beam evaporation technique and characterized them by transmission electron microscopy (TEM). An Fe film was deposited on a Si(100) substrate, followed by thermal annealing at 1073 K for 2 h. It was found that epitaxially grown nanoparticles with an average size of ∼ 10 nm were formed just beneath the Si surface, suggesting that the deposited Fe atoms diffuse into the substrate. Every single phase of nanoparticles was examined in detail by TEM observation, nanobeam electron diffraction, and energy-dispersive x-ray spectroscopy. Plan-view and cross-sectional TEM observations revealed that these nanoparticles consist of α-, α-, and γ-FeSi ₂. It was found that the morphology of nanoparticles is closely related to the phases. The α and β phases consist of angled hemisphere and asymmetric triangle-shaped nanoparticles, respectively, while the γ phase consists of hemispherical or columnar-shaped nanoparticles. These particle morphologies are discussed with respect to the lattice mismatches between the particles and the matrix. © 2006 American Institute of Physics.Jong Han Won, Kazuhisa Sato, Manabu Ishimaru, and Yoshihiko Hirotsu, "Transmission electron microscopy study on FeSi₂ nanoparticles synthesized by electron-beam evaporation", Journal of Applied Physics 100, 014307 (2006) https://doi.org/10.1063/1.2209751