Summary form only given. In the past, we have produced stable z-pinch implosions with an outer Ne shell imploding on an inner Ar (Ne-on-Ar) gas puff load. Using a similar mass density profile to the ...Ne-on-Ar experiments, we observed that Ar-on-Ne implosions were not stable. In this paper, we present the investigations of the Ne-on-Ar and Ar-on-Ne implosion dynamics with various mass density profiles. The experiments are conducted on the 1-MA, 200-ns COBRA generator. A triple-nozzle is used to produce z-pinch loads with concentric outer and inner annular gas puffs and a center gas puff. Z-pinch loads such as Ne-on-Ar and Ar-on-Ne with or without a center gas jet will be tested. In the experiments, we will use Planar Laser Induced Fluorescence (PLIF) to determine the initial gas puff mass density profile, and a three-frame Laser Shearing Interferometer (LSI) for imploding plasma density profiles. Two four-frame gated XUV cameras capture the implosion plasma structure. A multi-channel, filtered pinhole x-ray camera images the pinch plasma. The Ar and Ne x-ray spectra will be recorded by a spherical crystal x-ray spectrometer. Two spatially resolved UV and visible light spectrometers are used to measure the emission line profiles. The measurements will be compared with the predictions from a 2D multi-material radiation MHD model.
In critically ill patients with aortic stenosis and left ventricular dysfunction, vasodilator therapy has been considered to be contraindicated because of concern that it could cause hypotension. In ...this study, nitroprusside was administered to 25 such patients under carefully monitored conditions and, contrary to traditional teaching, was found to cause substantial improvement in the cardiac index and other hemodynamic variables.
Improvements in critically ill patients with vasodilator therapy.
Aortic stenosis is one of the most common types of valvular heart disease worldwide. Concomitant left ventricular dysfunction is often present, typically a result of the aortic stenosis itself or of coexisting coronary artery disease. Congestive heart failure and left ventricular dysfunction in the setting of severe aortic stenosis are associated with a high mortality rate. Although Ross and Braunwald noted a median survival of 1.5 to 2.0 years in patients with severe aortic stenosis and symptomatic congestive heart failure,
1
more recent studies have indicated that patients with severe aortic stenosis and abnormal left ventricular function on echocardiography survive a . . .
The receptor-mediated adhesion of cells to ligand-coated surfaces is important in many physiological and biotechnological processes. Previously, we measured the detachment of antibody-coated spheres ...from counter-antibody- and protein A-coated substrates using a radial-flow detachment assay and were able to relate mechanical adhesion strength to chemical binding affinity (Kuo and Lauffenburger, Biophys. J. 65:2191–2200 (1993)). In this paper, we use "adhesive dynamics" to simulate the detachment of antibody-coated hard spheres from a ligand-coated substrate. We modeled the antibody-ligand (either counter-antibody or protein A) bonds as adhesive springs. In the simulation as in the experiments, beads attach to the substrate under static conditions. Flow is then initiated, and detachment is measured by the significant displacement of previously bound particles. The model can simulate the effects of many parameters on cell detachment, including hydrodynamic stresses, receptor number, ligand density, reaction rates between receptor and ligand, and stiffness and reactive compliance of the adhesive springs. The simulations are compared with experimental detachment data, thus relating measured bead adhesion strength to molecular properties of the adhesion molecules. The simulations accurately recreated the logarithmic dependence of adhesion strength on affinity of receptor-ligand recognition, which was seen in experiments and predicted by analytic theory. In addition, we find the value of the reactive compliance, the parameter which relates the strain of a bond to its rate of breakage, that gives the best match between theory and experiment to be 0.01. Finally, we analyzed the effect of varying either the forward or reverse rate constants as different ways to achieve the same affinity, and showed that adhesion strength depends uniquely on the equilibrium affinity, not on the kinetics of binding. Given that attachment is independent of affinity, detachment and attachment are distinct adhesive phenomena.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
Many constructed wetlands adequately treat BOD5, TSS, and bacteria. However, a review of nitrogen (N) data from 52 constructed and natural wetlands in the North American data base confirmed that N ...removal was variable. Nitrification and denitrification require aerobic and anaerobic conditions. This paper presents case histories of systems that use alternating shallow and deep water zones to create both environments. Regression analysis of N removal and N loadings in 18 shallow-deep water systems suggested that NH4+ loading (kg N/ha/day) could be used to predict effluent NH4+ values. Combinations of shallow water-emergent vegetation and deep water-submergent vegetation with low NH4+ (and TKN) loading rates can produce very low levels of discharged NH4+.
In this essay, I explore the work of two scholars-Ian Morris and Leslie Kurke-and one of their claims: that the archaic Greek symposium served as the site for an anti-polis ideology. I first examine ...the conceptual underpinnings that guide their understanding of the operation of ideology. I then look closely at the arguments and evidence provided by Morris and Kurke. I argue that their respective conclusions about the symposium are not sustained even by their own evidence but rest on a set of problematic assumptions about the operation of ideology that they have imported into their analysis.
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BFBNIB, INZLJ, NMLJ, NUK, PNG, SAZU, UL, UM, UPUK, ZRSKP
The pulsed holmium:YAG laser (lambda = 2.12 microm, tau(p) = 250 micros) has been investigated as a method for inducing localized coagulation for medical procedures, yet the dynamics of this process ...are not well understood. In this study, photocoagulation of albumen (egg white) was analysed experimentally and results compared with optical-thermal simulations to investigate a rate process approach to thermal damage and the role of heat conduction and dynamic changes in absorption. The coagulation threshold was determined using probit analysis, and coagulum dynamics were documented with fast flash photography. The nonlinear computational model, which included a Beer's law optical component, a finite difference heat transfer component and an Arrhenius equation-based damage calculation, was verified against data from the literature. Moderate discrepancies between simulation results and our experimental data probably resulted from the use of a laser beam with an irregular spatial profile. This profile produced a lower than expected coagulation threshold and an irregular damage distribution within a millisecond after laser onset. After 1 ms, heat conduction led to smoothing of the coagulum. Simulations indicated that dynamic changes in absorption led to a reduction in surface temperatures. The Arrhenius equation was shown to be effective for simulating transient albumen coagulation during pulsed holmium:YAG laser irradiation. Greater understanding of pulsed laser-tissue interactions may lead to improved treatment outcome and optimization of laser parameters for a variety of medical procedures.
Objectives: Proton pump inhibitors (PPI) used to suppress acid secretion in the stomach are among the most widely prescribed medications. There is emerging evidence of proton secretion elsewhere in ...the aerodigestive tract, and acidic microenvironments are integral to oral flora such as Lactobacillus. The hypothesis of this study is that the growth rate and morphology of oral Lactobacillus strains are effected by PPIs.
Methods: Nineteen different strains of Lactobacilli were inoculated in microtiter plates at pH of 4.5 to 6.5 and exposed to twofold dilutions of pantoprazole at a range of 2.5 mg/mL to 2.5 μg/mL. Bacterial growth was monitored, and the minimum inhibitory concentration (MIC) of the drug was determined for the strains most sensitive to pantoprazole.
Results: In the unexposed (control) group, nine Lactobacilli strains were affected by pH changes from 6.5 to 4.5. In the group exposed to pantoprazole, 9 of the 19 Lactobacilli strains were found to have an MIC below 625 μg/mL, with L. plantarum 14917 being the most sensitive (MIC = 20 μg/mL). In some strains, such as L. s. salivarius 11741, Gram‐staining revealed conformational changes in the bacteria when grown in the presence of pantoprazole.
Conclusion: Growth rates and morphology of oral Lactobacillus are affected by the pH of the environment. Pantoprazole at supraphysiologic doses further affects growth rates and conformation in some strains.
Significance: The balance of oral flora and upper digestive tract homeostasis may be affected by unexpected targets of PPI pharmacotherapy, with possible unanticipated consequences.
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BFBNIB, FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Frequency distributions of soil property values are largely unknown, yet they are important to studies of soil variability. Our objectives in this paper were to (i) evaluate the distributional ...normality of soil properties within and among upland geomorphic surfaces, and (ii) interpret these distributions in terms of pedogenic factors and processes. Sixty soil properties were measured from 257 pedons along point transects in a 40‐ha upland Missouri pasture. Five of the 60 tested variables approximated normality. About three‐quarters of the distributions were asymmetric (skewed), and over four‐fifths were misshapen (kurtotic). Partitioning the samples by geomorphic surface (ridge, shoulder and backslope) improved the normalities, symmetries and shapes of many, but not all, distributions. A priori assumptions of normality are not warranted for most soil properties. Care should be taken when applying statistical tests that are sensitive to departures from normality. However, asymmetric or misshapen distributions provide meaningful information. Extended tails in skewed distributions represent outliers or inclusions in soil survey map units. These distributions result from variation in depositional environments or the asymmetric effects of pedogenic or hydrologic processes. Kurtotic distributions may indicate the presence within the sample of subpopulations with differing means or variances. Distributions provide important clues to understanding spatial variability.
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FZAB, GIS, IJS, KILJ, NLZOH, NUK, OILJ, SBCE, SBMB, UL, UM, UPUK
Neutrophils rely on rapid changes in morphology to ward off invaders. Time-resolved dynamics of spreading human neutrophils after activation by the chemoattractant fMLF (formyl methionyl leucyl ...phenylalanine) was observed by RICM (reflection interference contrast microscopy). An image-processing algorithm was developed to identify the changes in the overall cell shape and the zones of close contact with the substrate. We show that in the case of neutrophils, cell spreading immediately after exposure of fMLF is anisotropic and directional. The dependence of spreading area,
A, of the cell as a function of time,
t, shows several distinct regimes, each of which can be fitted as power laws (
A ∼
t
b). The different spreading regimes correspond to distinct values of the exponent
b and are related to the adhesion state of the cell. Treatment with cytochalasin-B eliminated the anisotropy in the spreading.
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GEOZS, IJS, IMTLJ, KILJ, KISLJ, NLZOH, NUK, OILJ, PNG, SAZU, SBCE, SBJE, UILJ, UL, UM, UPCLJ, UPUK, ZAGLJ, ZRSKP
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