Effect of Chronic Alcohol Consumption on Phosphatidylcholine Hydroperoxide Content of Rat Liver and Brain

Purpose: To investigate the correlation between alcohol-induced oxidative stress and tissue phosphatidylcholine hydroperoxide (PC-OOH) content of rat liver and brain.Methods: Ten Wistar rats were divided into two groups: one group was given 20 % ethanol (5 g/kg) and the other the same volume of normal saline, orally once a day for 6 weeks. Catalase activity, malondialdehyde (MDA) content, total antioxidant capacity (TAC) and PC-OOH content of liver and brain were determined.Results: The ethanol-treated group had lower catalase activity and total antioxidant capacity. MDA level in the liver was 0.33 ± 0.07 μM/mg protein which is significantly (p < 0.05) higher than that of the control group (0.17 ± 0.06 μM/mg protein), but in brain, there was no significant difference. PC-OOH level in the ethanol-treated group was 46.91 ± 12.87 pmol/mg in liver and 71.97 ± 26.12 pmol/mg protein in brain while PC-OOH level of control group was 21.40 ± 10.71 pmol/mg protein in liver and that in brain was 25.29 ± 5.67 pmol/mg protein pmol. Thus, PC-OOH levels in both liver and brain were significantly (p < 0.05) higher than that of control group. PC-OOH content in the liver and brain correlated significantly (p < 0.05) with catalase activity and total antioxidant capacity (TAC).Conclusion: The study demonstrates that PC-OOH content in liver and brain tissues may be a marker for alcohol-induced oxidative stress.Keywords: Alcohol Toxicity, Oxidative Stress, Phosphatidylcholine Hydroperoxide, Liver, Brain, Biomarke

Farmer-Managed Natural Regeneration Enhances Rural Livelihoods in Dryland West Africa

Declining agricultural productivity, land clearance and climate change are compounding the vulnerability of already marginal rural populations in West Africa. 'Farmer-Managed Natural Regeneration' (FMNR) is an approach to arable land restoration and reforestation that seeks to reconcile sustained food production, conservation of soils and protection of biodiversity. It involves selecting and protecting the most vigorous stems regrowing from live stumps of felled trees, pruning off all other stems, and pollarding the chosen stems to grow into straight trunks. Despite widespread enthusiasm and application of FMNR by environmental management and development projects, to date, no research has provided a measure of the aggregate livelihood impact of community adoption of FMNR. This paper places FMNR in the context of other agroforestry initiatives, then seeks to quantify the value of livelihood outcomes of FMNR. We review published and unpublished evidence about the impacts of FMNR, and present a new case study that addresses gaps in the evidence base. The case study focuses on a FMNR project in the district of Talensi in the semi-arid Upper East Region in Ghana. The case study employs a Social Return on Investment (SROI) analysis, which identifies proxy financial values for non-economic as well as economic benefits. The results demonstrate income and agricultural benefits, but also show that asset creation, increased consumption of wild resources, health improvements and psycho-social benefits created more value in FMNR-adopting households during the period of the study than increases in income and agricultural yields

Three-Dimensional Evolution of the Parker Instability under a Uniform Gravity

Using an isothermal MHD code, we have performed three-dimensional, high-resolution simulations of the Parker instability. The initial equilibrium system is composed of exponentially-decreasing isothermal gas and magnetic field (along the azimuthal direction) under a uniform gravity. The evolution of the instability can be divided into three phases: linear, nonlinear, and relaxed. During the linear phase, the perturbations grow exponentially with a preferred scale along the azimuthal direction but with smallest possible scale along the radial direction, as predicted from linear analyses. During the nonlinear phase, the growth of the instability is saturated and flow motion becomes chaotic. Magnetic reconnection occurs, which allows gas to cross field lines. This, in turn, results in the redistribution of gas and magnetic field. The system approaches a new equilibrium in the relaxed phase, which is different from the one seen in two-dimensional works. The structures formed during the evolution are sheet-like or filamentary, whose shortest dimension is radial. Their maximum density enhancement factor relative to the initial value is less than 2. Since the radial dimension is too small and the density enhancement is too low, it is difficult to regard the Parker instability alone as a viable mechanism for the formation of giant molecular clouds.Comment: 8 pages of text, 4 figures (figure 2 in degraded gif format), to appear in The Astrophysical Journal Letters, original quality figures available via anonymous ftp at ftp://ftp.msi.umn.edu/pub/users/twj/parker3d.uu or ftp://canopus.chungnam.ac.kr/ryu/parker3d.u

Towards identifying flame patterns in multiple, late injection schemes on a single cylinder optical diesel engine

The work investigates the effect of various post-injection strategies on the flame patterns in a Ricardo Hydra optical single cylinder light duty diesel engine, operated in a partially premixed combustion mode (PPC), under low load (IMEP: ca. 2.3 bar) low speed (1200 rpm) conditions. The effect of postinjection fuel amount (12 and 24% of the total fuel quantity per cycle) and post-injection timing (0, 5, 10 deg aTDC) are investigated via pressure trace analysis and optical measurements. Flame propagation is captured by means of high speed flame natural luminosity imaging and of CH* , C2 * and OH* line-of-sight chemiluminescence measurements. Results indicate that post-injections suppress mixture reactivity but enhances oxidation, and that a larger amount of fuel and/or later post injection, leads to higher levels of natural luminosity, indicating possible higher soot-out emissions, while post injection close to the main combustion event appears to have a beneficial effect on the soot oxidation processes

Effect of quasicrystalline phase on the deformation behavior of Zr62Al9.5Ni9.5Cu14Nb5 bulk metallic glass

Quasicrystalline phase with different volume fraction were formed by isothermally annealing the as-castZr(62)Al(9.5)Ni(9.5)Cu(14)Nb(5) bulk metallic glass at 723 K for different times. The effects of quasicrystals on the deformation behavior of the materials were studied by nanoindentation and compression test. It revealed that the alloys with homogeneous amorphous structure exhibit pronounced flow serrations during the nanoindentation loading, while no obvious flow serration is observed for the sample with quasicrystals more than 10 vol.%. However, further compression tests confirm that the no-serrated flows are formed due to different reasons. For annealed samples containing quasicrystals less than 35 vol.%, continuous plastic deformation occurs due to propagation of multiple shear bands. While the disappearance of serrated flow cannot be explained by the generation of multiple shear bands for samples containing quasicrystals more than 35 vol.%, which will fracture with a totally different fracture mode, namely, dimple fracture mode under loading instead of shear fracture mode. (c) 2005 Published by Elsevier B.V

Strange form factors in the context of SAMPLE, HAPPEX, and A4 experiments

The strange properties of the nucleon are investigated within the framework of the SU(3) chiral quark-soliton model assuming isospin symmetry and applying the symmetry conserving SU(3) quantization. We present the form factors $G^0_{E,M}(Q^2)$, $G^Z_M(Q^2)$ and the electric and magnetic strange form factors $G^s_{E,M}(Q^2)$ incorporating pion and kaon asymptotics. The results show a fairly good agreement with the recent experimental data from the SAMPLE and HAPPEX collaborations. We also present predictions for future measurements including the A4 experiment at MAMI (Mainz).Comment: 10 pages with four figures. RevTeX4 is used. Few lines are changed. Accepted for publication in Phys.Rev.

A Comparative Study of the Parker Instability under Three Models of the Galactic Gravity

To examine how non-uniform nature of the Galactic gravity might affect length and time scales of the Parker instability, we took three models of gravity, uniform, linear and realistic ones. To make comparisons of the three gravity models on a common basis, we first fixed the ratio of magnetic pressure to gas pressure at $\alpha$ = 0.25, that of cosmic-ray pressure at $\beta$ = 0.4, and the rms velocity of interstellar clouds at $a_s$ = 6.4 km s$^{-1}$, and then adjusted parameters of the gravity models in such a way that the resulting density scale heights for the three models may all have the same value of 160 pc. Performing linear stability analyses onto equilibrium states under the three models with the typical ISM conditions, we calculate the maximum growth rate and corresponding length scale for each of the gravity models. Under the uniform gravity the Parker instability has the growth time of 1.2$\times10^{8}$ years and the length scale of 1.6 kpc for symmetric mode. Under the realistic gravity it grows in 1.8$\times10^{7}$ years for both symmetric and antisymmetric modes, and develops density condensations at intervals of 400 pc for the symmetric mode and 200 pc for the antisymmetric one. A simple change of the gravity model has thus reduced the growth time by almost an order of magnitude and its length scale by factors of four to eight. These results suggest that an onset of the Parker instability in the ISM may not necessarily be confined to the regions of high $\alpha$ and $\beta$.Comment: Accepted for publication in ApJ, using aaspp4.sty, 18 text pages with 9 figure

Controlled selective growth of ZnO nanorod and microrod arrays on Si substrates by a wet chemical method

The use of a wet chemical method to selectively grow ZnO microrod and nanorod arrays on Si substrates is described. To control the size and position of the ZnO microrods and nanorods, polymethylmethacrylate (PMMA) submicron patterns were prepared on the Si substrates with an intermediate ZnO layer using e-beam lithography. Selective growth of the ZnO structures was achieved by the absence of ZnO nucleation sites on the PMMA mask, resulting in position-controlled growth of ZnO structures only on patterned holes where the ZnO layer was exposed. In addition, the diameters of the ZnO microrods were determined by the patterned hole size, and the diameters as small as 250 nm were obtained when a hole diameter of 250 nm was employed. The structural and optical characteristics of the ZnO microrods were further investigated using x-ray diffraction, transmission electron microscopy, and photoluminescence spectroscopy. (c) 2006 American Institute of Physics.open11107109sciescopu