Elements that Influence the Implementation of Crisis Preparedness Measures by Meeting Planners

The purpose of this study was to analyse the adoption of crisis preparedness measures by meeting planners. The study sought to determine how the adoption of crisis preparedness measures relates to meeting planner characteristics and identify the elements that influence their adoption (or lack of adoption) of these measures. A survey of professional meeting planners identified significant differences in the frequency of use of some key core crisis preparedness measures. Additionally, 10 categories of elements influencing the adoption of or failure to adopt crisis preparedness measures were identified. The findings of this study should be of interest to meeting organizers and professionals who want to make their meetings more crisis prepared rather than crisis prone.     

Salacia mulbarica leaf extract mediated synthesis of silver nanoparticles for antibacterial and ct‐DNA damage via releasing of reactive oxygen species

In this examination, we researched the advantages of DNA fragmentation and metallic nanoparticles well‐appointed with biomolecules. A novel interpretation of DNA damage by Silver Nano‐Clusters (AgNCs) which were developed by the utilization of green synthesis method was demonstrated. The green synthesis of AgNCs was accomplished by utilizing the leaf extract of Salacia mulbarica (SM). The preparation of SM‐AgNCs was developed by estimating surface plasmon resonance peak around 449 nm by using a UV–Visible spectrophotometer. The effect of phytochemicals in SM leaf extract on the development of stable SM‐AgNCs was confirmed by FTIR spectroscopy. The size of the fabricated SM‐AgNCs was estimated by dynamic light scattering and zeta‐sizer analysis and the morphology of the SM‐AgNCs was examined by transmission electron microscopy. The presence of clusters of Ag particles in the prepared SM‐AgNCs was recognized by energy dispersion X‐ray analysis. The results show that saponins, phytosterols, and phenolic compounds present in plant extract may play a great part in developing the SM‐AgNCs in their specialized particles. The succeeded SM‐AgNCs shows incredible anti‐bacterial action towards Escherichia coli and Bacillus subtilis. In‐light of the antibacterial study, these SM‐AgNCs were analyzed with calf thymus‐DNA and found significant damage to the strand of thymus‐DNA.Inspec keywords: visible spectra, surface plasmon resonance, transmission electron microscopy, DNA, nanofabrication, particle size, X‐ray chemical analysis, ultraviolet spectra, molecular biophysics, nanomedicine, microorganisms, nanoparticles, silver, X‐ray diffraction, antibacterial activity, Fourier transform infrared spectra, biomedical materialsOther keywords: stable SM‐AgNCs, silver nanoparticles, ct‐DNA damage, metallic nanoparticles, silver nanoclusters, Salacia mulbarica leaf extract, reactive oxygen species, DNA fragmentation, surface plasmon resonance, UV‐Visible spectrophotometer, Fourier transform infrared spectroscopy, dynamic light scattering, Zeta‐sizer analysis, transmission electron microscopy, energy dispersive X‐ray analysis, saponins, phytosterols, phenolic compounds, plant extract, Escherichia coli, Bacillus subtilis, Ag     

von Neumann stability analysis of first-order accurate discretization schemes for one-dimensional (1D) and two-dimensional (2D) fluid flow equations

In literature, the von Neumann stability analysis of simplified model equations, such as the wave equation, is typically used to determine stability conditions for the non-linear partial differential fluid flow equations (Navier–Stokes and Euler). However, practical experience suggests that such simplistic stability conditions are grossly inadequate for computations involving the system of coupled flow equations. The goal of this paper is to determine stability conditions for the full system of fluid flow equations – the Euler equations are examined, as any conditions derived for the Euler equations will apply to the Navier–Stokes (NS) equations in the limit of convection-dominated flows. A von Neumann stability analysis is conducted for the one-dimensional (1D) and two-dimensional (2D) Euler equations. The system of equations is discretized on a staggered grid using finite-difference discretization techniques; the use of a staggered grid allows equivalence to finite-volume discretization. By combining the different discretization techniques, ten solution schemes are formulated – eight solution schemes are considered for the 1D Euler equations, and two schemes for the 2D Euler equations. For each scheme, error amplification matrices are determined from the stability analysis, stable and unstable regimes are identified, and practical stability limits are predicted in terms of the maximum-allowable CFL (Courant–Friedrichs–Lewy) number as a function of Mach number. The predictions are verified for selected schemes using the Riemann problem at incompressible and compressible Mach numbers. Very good agreement is obtained between the analytically predicted and the “experimentally” observed CFL values. The successfully tested stability limits are presented in graphical form, which offer a viable alternative to complicated mathematical expressions often reported in published literature, and should benefit everyday CFD (Computational Fluid Dynamics) users. The stability regions are used to discuss the effect of time integration (explicit vs. implicit), density bias in continuity equation and momentum convection term linearization on stability. A comparison of the predicted stability limits for 1D and 2D Euler equations with commonly-used stability conditions arising from the wave equation shows that the stability thresholds for the Euler equations lie well below those predicted by the wave equation analysis; in addition, the 2D Euler stability limits are more restrictive as compared to 1D Euler limits. Since the present analysis accounts for the full system of fluid flow (Euler) equations, the derived stability conditions can be used by CFD practitioners to estimate a timestep or CFL number to guide the stability of their computations.     

Depletion of intracellular Ca2+ stores, phosphorylation of eIF2alpha, and sustained inhibition of translation initiation mediate the anticancer effects of clotrimazole

Regulation of translation initiation plays a critical role in the control of cell growth and division in eukaryotic cells. Translation of many growth regulatory proteins including cyclins depends critically on translation initiation factors because their mRNAs are translated inefficiently. We report that clotrimazole, a potent antiproliferative agent both in vitro and in vivo, inhibits cell growth by interfering with translation initiation. In particular, clotrimazole causes a sustained depletion of intracellular Ca2+ stores, which results in activation of PKR, phosphorylation of eIF2alpha, and thereby in inhibition of protein synthesis at the level of translation initiation. Consequently, clotrimazole preferentially decreases the expression of the growth promoting proteins cyclin A, E and D1, resulting in inhibition of cyclin-dependent kinase activity and blockage of cell cycle in G1.     

Biodistribution of liposomes of terbutaline sulfate in guinea pigs

A series of liposomes was prepared with various lipid (egg phosphatidyl choline [egg PC], phosphatidyl glycerol [PG], dipalmitoyl phosphatidylcholine [DPPC], distearoyl phosphatidyl choline [DSPC], dipalmitoyl phosphatidyl glycerol [DPPG], phosphatidyl ethanolamine [PE], cholesterol [CH], and stearylamine [SA]) compositions, such as egg PC:PG:CH (55:5:40), DPPC:PG:CH (55:5:40), DSPC:DSPG:CH (55:5:40) egg PC:SA:CH (55:5:40), DSPE:DSPG:CH (55:5:40) in molar ratio. Liposomal formulations were administered to guinea pigs intravenously; 3 hr after the treatment, serum samples and various organs (e.g., liver, spleen, lung) were removed and analyzed for drug concentration by a high-performance liquid chromatographic (HPLC) method. Based on the above study, a liposomal preparation with better lung specificity was selected, and the time profile of these liposomes was determined in guinea pigs. Three hours postadministration, a significant difference in blood levels was observed between free terbutaline sulfate and the various liposomal formulations. Localization of the drug in the lungs increased considerably when encapsulated drug was used, and the highest percentage localization was observed with DSPC:DSPG:CH (55:5:40) liposomes. The percentage recovery of the drug in the lungs with egg PC:CH:SA (55:40:5) liposomes did not change significantly when compared with egg PC:CH:PG (55:40:5) liposomes. To establish the time course of disposition of the liposomes, DSPC:SPG:CH (55:5:40) liposomes were selected. Terminal half-life t_1/2 of the drug in blood with free drug solution was about 12 hr, whereas with liposomes, a twofold increase in t_1/2 was observed. The disposition data indicated that the clearance of the drug was delayed by 1.5 times when incorporated into liposomes.