Simulating Bed-Load Transport in a Complex Gravel-Bed River

An existing two-dimensional mobile-bed hydrodynamic model has been modified to simulate bed-load transport in a complex gravel-bed river. We investigated the sensitivity of predicted bed load to control parameters, and compared model predictions of flow depth, shear stress, and gravel transport with field measurements made from the river. The predictions are based on concurrent field data of flow discharge, water level, and sediment for model input. The model takes into account multiple-fraction transport rates, and continuously updates the river bed and surface grain-size distribution. The model predictions are in reasonable agreement with field measurements.     

Relationship between plasma phospholipid transfer protein activity and HDL subclasses among patients with low HDL and cardiovascular disease

NK lysin is a 9-kDa polypeptide that was originally isolated from porcine intestinal tissue based on its antibacterial activity. It is produced by cytolytic lymphocytes and is cytolytic against a number of different types of tumor cells. Here we report the binding of NK lysin to lipopolysaccharide (LPS) and its anti-LPS activity. NK lysin binds to matrix-coated LPS from Escherichia coli, Pseudomonas aeruginosa, and different strains of Salmonella enterica. Lipid A and polymyxin B inhibited the binding, demonstrating a preferential interaction of NK lysin with the lipid part of LPS. Chromium-labeled lymphoma cells were lysed by NK lysin, and LPS dose-dependently inhibited the cytolysis at equimolar amounts. In the same manner, NK lysin inhibited certain LPS-stimulated effects on mouse bone marrow cells as well as LPS binding to mouse granulocytes. These results suggest that NK lysin may be a another natural LPS-binding protein from lymphocytes that may participate in the endogenous defense response associated with elevated concentrations of LPS.     

Thought-induced attitude change: The effects of schema structure and commitment.

Conducted 4 studies with 218 undergraduates in an attempt to integrate hypotheses about the effects of thought and schema complexity on attitude polarization proposed by P. W. Linville (see record 1982-25791-001) and the 2nd author and C. Leone (see record 1978-09847-001). Linville's work showed that more extreme attitudes were associated with simpler cognitive schemas for construing the attitude object. The 2nd author and Leone demonstrated that thought with a complex schema resulted in greater attitude polarization than thought with a simple schema. Study 1 validated the present author's schema complexity manipulation. Study 2 tested and found support for the hypothesis that 1 moderating variable was motivational: The 2nd author and Leone's effect was obtained in the presence of commitment to an initial evaluation, and there was a tendency toward the Linville effect in the absence of commitment to an initial evaluation. Study 3 tested and found support for the hypothesis that another moderating variable was structural: The Linville effect was obtained when there was little correlation among the dimensions of the cognitive schema, and the 2nd author and Leone's effect was obtained when there was substantial correlation among the dimensions; thought tended to increase the correlation among dimensions. Study 4 tested and found support for the hypothesis that commitment affects cognitive structures in a way that could account for its moderating effect on attitude polarization. (23 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Cytokines in human breast milk

Out of the total number at 200 suspected cases of otomycoses consisting of 40 malnourished and 160 apparently healthy children examined in this study between the months of July and August in Edo State, 64 Cases (32%) were identified to be of fungal aetiology on the basis of positive culture and careful microscopic examination. The state at protein energy malnourishment was deterwined using physicians' comments in their case files. The fungal agents isolated were Aspergillus niger 28 (43.8%); A. fumigatus 4 (25%); Fusarium solari 4 (6.3%); Candida albicans 8 (12.5%); and Hendersonula teruloidea types torn B 5 (6.3%). Of these isolates, A. niger having an solation rate of (43.8%) was found to be the most predominant fungal species associated with otomycosis.     

Influence of Sodium Caseinate on the Dissolution Rate of Hydrochlorothiazide and Chlorothiazide

The solubility and dissolution characteristics of drug-casein systems were investigated and their solid state properties examined. Systems of varying drug-sodium caseinate weight fraction were prepared by physical mixing and freeze drying. Enhancements in the intrinsic dissolution rates were obtained for freeze dried systems of both drugs. The relative enhancement for 50/50 systems in phosphate buffer pH 7.4 was 5 fold and 1.5 fold for chlorothiazide and hydrochlorothiazide respectively. A 35 fold increase was observed for the chlorothiazide system in water, The release of both drugs from mechanically mixed systems in phosphate buffer approximated to a non interacting model, while release from hydrochlorothiazide systems in 0.1N HC1 showed a tendency towards matrix controlled release. Thus the magnitude of the effect is dependant on the nature of the drug, the content of carrier, the method of preparation and the dissolution medium.     

Fabrication and characterisation of D-fibres with a range of accurately controlled core/flat distances

The fabrication and evaluation of D-fibres, whose optical properties are compatible with standard single-mode fibre designs, is reported. The high tolerances achieved in the process of drawing a tapered preform are shown to be necessary for predicting the transverse coupling behaviour of the fibres.     

Regioselectivity of nitroglycerin denitration by flavoprotein nitroester reductases purified from two Pseudomonas species

Two species of Pseudomonas capable of utilizing nitroglycerin (NG) as a sole nitrogen source were isolated from NG-contaminated soil and identified as Pseudomonas putida II-B and P. fluorescens I-C. While 9 of 13 laboratory bacterial strains that presumably had no previous exposure to NG could degrade low concentrations of NG (0.44 mM), the natural isolates tolerated concentrations of NG that were toxic to the lab strains (1.76 mM and higher). Whole-cell studies revealed that the two natural isolates produced different mixtures of the isomers of dinitroglycerol (DNG) and mononitroglycerol (MNG). A monomeric, flavin mononucleotide-containing NG reductase was purified from each natural isolate. These enzymes catalyzed the NADPH-dependent denitration of NG, yielding nitrite. Apparent kinetic constants were determined for both reductases. The P. putida enzyme had a Km for NG of 52 +/- 4 microM, a Km for NADPH of 28 +/- 2 microM, and a Vmax of 124 +/- 6 microM x min(-1), while the P. fluorescens enzyme had a Km for NG of 110 +/- 10 microM, a Km for NADPH of 5 +/- 1 microM, and a Vmax of 110 +/- 11 microM x min(-1). Anaerobic titration experiments confirmed the stoichiometry of NADPH consumption, changes in flavin oxidation state, and multiple steps of nitrite removal from NG. The products formed during time-dependent denitration reactions were consistent with a single enzyme being responsible for the in vivo product distributions. Simulation of the product formation kinetics by numerical integration showed that the P. putida enzyme produced an approximately 2-fold molar excess of 1,2-DNG relative to 1,3-DNG. This result could be fortuitous or could possibly be consistent with a random removal of the first nitro group from either the terminal (C-1 and C-3) positions or middle (C-2) position. However, during the denitration of 1,2-DNG, a 1.3-fold selectivity for the C-1 nitro group was determined. Comparable simulations of the product distributions from the P. fluorescens enzyme showed that NG was denitrated with a 4.6-fold selectivity for the C-2 position. Furthermore, a 2.4-fold selectivity for removal of the nitro group from the C-2 position of 1,2-DNG was also determined. The MNG isomers were not effectively denitrated by either purified enzyme, which suggests a reason why NG could not be used as a sole carbon source by the isolated organisms.