Absorption effect in the calculation of a second-order nonlinear coefficient from the data of a maker fringe experiment

The effect of light absorption by sample in the analysis of Makerfringe data for estimating a second-order nonlinear coefficient hasbeen studied experimentally. Two theories, one by Jerphagnon andKurtz that neglects the absorption effect and one by Herman and Haydenthat takes into account the absorption effect, were compared with theexperimental results. It was found that Jerphagnon and Kurtz'sformula was unable to predict correctly not only the magnitude but alsothe incident angle dependence or the sample thickness dependence of thesecond harmonic signal generated by the sample with strong absorption, whereas the theory by Herman and Hayden was able to make thosepredictions fairly well. It was also found that the error in theestimated nonlinear coefficient when one uses Jerphagnon and Kurtz'sformula could be as large as 2-4 times the true value, depending onsample thickness.     

Odor discrimination using neural decoding of the main olfactory bulb in rats

This paper presents a novel method for inferring the odor based on neural activities observed from rats' main olfactory bulbs. Multichannel extracellular single unit recordings were done by microwire electrodes (tungsten, 50 μm, 32 channels) implanted in the mitral/tufted cell layers of the main olfactory bulb of anesthetized rats to obtain neural responses to various odors. Neural response as a key feature was measured by subtraction of neural firing rate before stimulus from after. For odor inference, we have developed a decoding method based on the maximum likelihood estimation. The results have shown that the average decoding accuracy is about 100.0%, 96.0%, 84.0%, and 100.0% with four rats, respectively.     

Effect of length on the fundamental resonance frequency of arterial models having radial dilatation

The pressure wave moving along an elastic artery filled with blood was examined as a moving Windkessel having a natural oscillation angular frequency nu 0 and a damping coefficient b. The radial directional motion for an element of the wall segment and the adherent fluid was considered. This equation was solved with conditions at both ends of an artery of length L. An external impulse force was applied at one end and a static pressure Po at the other. Analytic solution allowed only certain oscillation modes of resonance frequencies fn, where fn2 = a + cnL-2 with [formula: see text] and V infinity is the high frequency phase velocity. The relationship between f0 and L was examined experimentally for tubes constructed of latex, rubber, or dissected aorta. The effect of raising the static pressure P0 or increasing the tension in the tube was consistent with the prediction. The hypertension that accompanies an augmentation in arterial wall and the association between the heart rate and the mean blood pressure were discussed.     

Rice hull smoke extract inactivates Salmonella Typhimurium in laboratory media and protects infected mice against mortality

A previously characterized rice hull smoke extract (RHSE) was tested for bactericidal activity against Salmonella Typhimurium using the disc-diffusion method. The minimum inhibitory concentration (MIC) value of RHSE was 0.822% (v/v). The in vivo antibacterial activity of RHSE (1.0%, v/v) was also examined in a Salmonella-infected Balb/c mouse model. Mice infected with a sublethal dose of the pathogens were administered intraperitoneally a 1.0% solution of RHSE at four 12-h intervals during the 48-h experimental period. The results showed that RHSE inhibited bacterial growth by 59.4%, 51.4%, 39.6%, and 28.3% compared to 78.7%, 64.6%, 59.2%, and 43.2% inhibition with the medicinal antibiotic vancomycin (20 mg/mL). By contrast, 4 consecutive administrations at 12-h intervals elicited the most effective antibacterial effect of 75.0% and 85.5% growth reduction of the bacteria by RHSE and vancomycin, respectively. The combination of RHSE and vancomycin acted synergistically against the pathogen. The inclusion of RHSE (1.0% v/w) as part of a standard mouse diet fed for 2 wk decreased mortality of 10 mice infected with lethal doses of the Salmonella. Photomicrographs of histological changes in liver tissues show that RHSE also protected the liver against Salmonella-induced pathological necrosis lesions. These beneficial results suggest that the RHSE has the potential to complement wood-derived smokes as antimicrobial flavor formulations for application to human foods and animal feeds. PRACTICAL APPLICATION: The new antimicrobial and anti-inflammatory rice hull derived liquid smoke has the potential to complement widely used wood-derived liquid smokes as an antimicrobial flavor and health-promoting formulation for application to foods.     

Hypocholesterolaemic effect of yoghurt containing Bifidobacterium pseudocatenulatum G4 or Bifidobacterium longum BB536

The effect of a yoghurt supplement containing Bifidobacterium pseudocatenulatum G4 or Bifidobacterium longum BB536 on plasma lipids, lipid peroxidation and the faecal excretion of bile acids was examined in rats fed a cholesterol-enriched diet. After 8 weeks, the rats in the positive control (PC) group who were fed the cholesterol-enriched diet showed significant increases in plasma total cholesterol (TC), low-density lipoprotein (LDL) cholesterol, and malondialdehyde (MDA). However, groups fed a cholesterol-enriched diet supplemented with yoghurt containing B. pseudocatenulatum G4 or B. longum BB536 had significantly lower plasma TC, LDL-C, very-low-density lipoprotein (VLDL) cholesterol, and MDA than had the PC group after 8 weeks of treatment. In addition, faecal excretion of bile acids was markedly increased in the rats fed the yoghurt containing B. pseudocatenulatum G4 or B. longum BB536 as compared to the PC and NC groups.     

Atmospheric DMSO degradation in the gas phase: Cl-DMSO reaction. Temperature dependence and products

The reactions of Cl atoms and ClO radicals with CH3-SOCH3 (DMSO) have been studied using the discharge flow method with direct detection of DMSO, CO, and products by mass spectrometry. The absolute rate constant at room temperature measured for reaction 1, (CH3)2SO + Cl --> products, was k(1) = (1.7 +/- 0.3) x 10(-11) cm3 molecule(-1) s(-1). For reaction 2, (CH3)2SO + ClO --> products, only an upper limit could be established, k(2) < or = 6 x 10(-14) cm3 molecule(-1) s(-1) Reaction 1 has been found to proceed through adduct formation and further decomposition involving the cleavage of the C-S bound. The pressure effect on the Cl-DMSO reaction from 0.5 to 3 Torr was negligible, and the temperature dependence in the range 273-335 K was also very slight. The results obtained are related to previous studies of sulfur compounds, and the atmospheric implications are also discussed in relation to the homogeneous sinks of DMSO. Tropospheric lifetimes of DMSO based on average Cl and ClO concentrations and the measured rate constants have been calculated showing that the contribution of reaction 1 must be of minor relevance in the marine boundary layer. Reaction 2 is so slow that it does not play any role within the atmospheric sulfur chemistry.     

Benefits of two mitigation strategies for container vessels: cleaner engines and cleaner fuels

Emissions from ocean-going vessels (OGVs) are a significant health concern for people near port communities. This paper reports the emission benefits for two mitigation strategies, cleaner engines and cleaner fuels, for a 2010 container vessel. In-use emissions were measured following International Organization for Standardization (ISO) protocols. The overall in-use nitrogen oxide (NO(x)) emission factor was 16.1 ± 0.1 gkW(-1) h(-1), lower than the Tier 1 certification (17 gkW(-1) h(-1)) and significantly lower than the benchmark value of 18.7 gkW(-1) h(-1) commonly used for estimating emission inventories. The in-use particulate matter (PM(2.5)) emission was 1.42 ± 0.04 gkW(-1) h(-1) for heavy fuel oil (HFO) containing 2.51 wt % sulfur. Unimodal (～30 nm) and bimodal (～35 nm; ～75 nm) particle number size distributions (NSDs) were observed when the vessel operated on marine gas oil (MGO) and HFO, respectively. First-time emission measurements during fuel switching (required 24 nautical miles from coastline) showed that concentrations of sulfur dioxide (SO(2)) and particle NSD took ～55 min to reach steady-state when switching from MGO to HFO and ～84 min in the opposite direction. Therefore, if OGVs commence fuel change at the regulated boundary, then vessels can travel up to 90% of the distance to the port before steady-state values are re-established. The transient behavior follows a classic, nonlinear mixing function driven by the amount of fuel in day tank and the fuel consumption rate. Hence, to achieve the maximum benefits from a fuel change regulation, fuel switch boundary should be further increased to provide the intended benefits for the people living near the ports.     

Polybrominated diphenyl ethers in watershed soils of the Pearl River Delta, China: occurrence, inventory, and fate

Soils play an important role in the distribution and biogeochemical cycling of polybrominated diphenyl ethers (PBDEs) as they are a major reservoir and sink for PBDEs due to their large sorption capacity. In this study, concentrations, compositional profiles, mass inventories, and fate of sigma9PBDEs (28, 47, 66, 100, 99, 154, 153, 138, 183) and BDE 209 were investigated in 33 surface soils, six profile soils, and three point-source polluted soils (close to e-waste dismantling sites) from the Pearl River Delta (PRD), China. The concentrations of sigma9PBDEs and BDE 209 in the surface soils ranged from 0.13 to 3.81 ng/g with an average of 1.02 ng/g and from 2.38 to 66.6 ng/g with an average of 13.8 ng/g, respectively, and ranged from 1.93 to 19.5 ng/g and from 25.7 to 102 ng/g, respectively, in the point-source contaminated soils. The PBDE compositional patterns in the surface soils indicated deca-BDE, penta-BDE, and octa-BDE products as the main sources, but those in the point-source samples suggested deca-BDE and octa-BDE technical mixtures as the dominant sources. The mass inventories of PBDEs in soils of the PRD were estimated at 3.98 and 44.4 t for sigma9PBDEs and BDE 209, respectively. The average loading of PBDEs in the soils was comparable to that in the sediments of the Pearl River Estuary, suggesting that soil erosion and surface runoff are an important mode to transport PBDEs from terrestrial sources to oceans in the PRD. Individual BDE congeners, sigma9PBDEs, and PBDE 209, were significantly correlated with total organic carbon (TOC), and a good regression (except for BDE 47) between the logarithms of TOC-normalized BDE average concentrations and their log K(ow) was also obtained, indicating that sorption of PBDEs on soil organic matter governed their spatial distribution, transportation, and fate in the soils. Predicted aqueous and gaseous concentrations of PBDEs were derived from the soil-water and soil-air partitioning models, respectively, and good agreements were obtained between the predicted and previously reported values. BDE 47 and/or 28 did not appear to follow the same trend for these models, an indication that an portion of them was likely the biodegradation byproducts in soils.     

Preparation of tea catechins using polyamide

An adsorption separation method using Polyamide-6 (PA) as an adsorbent was developed to separate catechins from green tea extract. The adsorption capacity of total catechins for PA was 193.128 mg g⁻¹ with an adsorption selectivity coefficient K_A^B of total catechins over caffeine 21.717, which was better than macroporous resin model HPD 600. The Langmuir model and the pseudo-second order mode were primely fitted to describe its equilibrium data and adsorption kinetics, respectively. PA column separation by two-step elution using water and 80% (v/v) aqueous ethanol was established to prepare catechins complex which contained 670.808 mg g⁻¹ total catechins and 1.828 mg g⁻¹ caffeine. It is considered that PA was a promising adsorbent for selective isolation of catechins.