Bronchoalveolar lavage. Quantitation of intraalveolar fluid?

A precise calculation of the amount of intraalveolar fluid is the basis of a quantitative analysis of intraalveolar compounds. Different approaches have been made to cover this important problem. Here, we report a comparative study with five markers: 99mTc-DTPA, 51Cr-EDTA, inulin, urea, and methylene blue in animal experiments as well as in human experiments. The marker substances were added to the lavage fluid, and the "dilution" of the markers, i.e., the alveolar fluid, was calculated. The results showed that in animals with healthy lungs the tracer methods are able to calculate amounts of intraalveolar fluid that are comparable to morphologic findings. In animals as well as in humans, methylene blue and inulin were shown to be useless in determining alveolar fluid volume compared with the tracer methods. In humans, the calculations with the urea method and with Tc-DTPA were in the same magnitude, but there was no individual correlation. We conclude that, at present, the methods to quantitate alveolar fluid volume lack precision and add nothing to a deeper understanding of alveolar biology.     

Meshfree method for fluctuating hydrodynamics

In the current study a meshfree Lagrangian particle method for the Landau–Lifshitz Navier–Stokes (LLNS) equations is developed. The LLNS equations incorporate thermal fluctuation into macroscopic hydrodynamics by the addition of white noise fluxes whose magnitudes are set by a fluctuation–dissipation theorem. The study focuses on capturing the correct variance and correlations computed at equilibrium flows, which are compared with available theoretical values. Moreover, a numerical test for the random walk of standing shock wave has been considered for capturing the shock location.     

Integration of virtual and real environments for engineering service-oriented manufacturing systems

Engineering frameworks are currently required to support the easy, low-cost, modular and integrated development of manufacturing systems addressing the emergent requirements of re-configurability, responsiveness and robustness. This paper discusses the integration of 2D/3D digital software tools with Petri net based service-oriented frameworks to allow the design, configuration, analysis, validation, simulation, monitoring and control of manufacturing systems in a virtual environment and its posterior smooth migration into the real ??physical?? environment. An experimental case study was implemented to validate the proposed concepts, using the Continuum platform to design, compose, analyze, validate and simulate the Petri nets based service-oriented manufacturing control system, and the Delmia Automation^TM software suite to support the rapid prototyping and the easy simulation of the designed control solution. The experimental results prove several aspects of the proposed approach, notably the smooth migration between the design and the operation phases, one of the main objectives of the work.     

Implementing molecular dynamics on hybrid high performance computers – Particle–particle particle-mesh

The use of accelerators such as graphics processing units (GPUs) has become popular in scientific computing applications due to their low cost, impressive floating-point capabilities, high memory bandwidth, and low electrical power requirements. Hybrid high-performance computers, machines with nodes containing more than one type of floating-point processor (e.g. CPU and GPU), are now becoming more prevalent due to these advantages. In this paper, we present a continuation of previous work implementing algorithms for using accelerators into the LAMMPS molecular dynamics software for distributed memory parallel hybrid machines. In our previous work, we focused on acceleration for short-range models with an approach intended to harness the processing power of both the accelerator and (multi-core) CPUs. To augment the existing implementations, we present an efficient implementation of long-range electrostatic force calculation for molecular dynamics. Specifically, we present an implementation of the particle–particle particle-mesh method based on the work by Harvey and De Fabritiis. We present benchmark results on the Keeneland InfiniBand GPU cluster. We provide a performance comparison of the same kernels compiled with both CUDA and OpenCL. We discuss limitations to parallel efficiency and future directions for improving performance on hybrid or heterogeneous computers.     

How to detect a counterfeit coin: Adaptive versus non-adaptive solutions

In an old weighing puzzle, there are n?3 coins that are identical in appearance. All the coins except one have the same weight, and that counterfeit one is a little bit lighter or heavier than the others, though it is not known in which direction. What is the smallest number of weighings needed to identify the counterfeit coin and to determine its type, using balance scales without measuring weights? This question was fully answered in 1946 by Dyson [The Mathematical Gazette 30 (1946) 231-234]. For values of n that are divisible by three, Dyson's scheme is non-adaptive and hence its later weighings do not depend on the outcomes of its earlier weighings. For values of n that are not divisible by three, however, Dyson's scheme is adaptive. In this note, we show that for all values n?3 there exists an optimal weighing scheme that is non-adaptive.     

Hydrogen oxidation on gold electrode in sulphuric acid solution

The aim of this work is to study the electrochemical oxidation of Hydrogen on gold electrodes in sulphuric acid solution and to compare the results with those obtained in a similar study in perchloric acid solution. In both electrolytes, the reaction is irreversible because the atomic H, which appears as reaction intermediate, diffuses inside of the metal. The reactive is introduced in two ways: by electrolysis at a cathodic potential during different times and by saturating the solution with the gaseous reactive. During the cathodic electrolysis the different crystalline planes of the surface reconstruct and this feature has an influence on the reaction kinetics. The catalytic influence of the incipient hydrous gold oxide on the H electrooxidation is also shown. The presence of sulphate and perchlorate ions leads to unlike voltamperometric profiles in the double layer charging potential region. A gold compound is formed during the metal treatment and an attempt has been done to identify it with FTIR.     

The Flexible Rare Event Sampling Harness System (FRESHS)

We present the software package FRESHS (http://www.freshs.org) for parallel simulation of rare events using sampling techniques from the ‘splitting’ family of methods. Initially, Forward Flux Sampling (FFS) and Stochastic Process Rare Event Sampling (SPRES) have been implemented. These two methods together make rare event sampling available for both quasi-static and full non-equilibrium regimes. Our framework provides a plugin system for software implementing the underlying physics of the system of interest. At present, example plugins exist for our framework to steer the popular MD packages GROMACS, LAMMPS and ESPResSo, but due to the simple interface of our plugin system, it is also easy to attach other simulation software or self-written code. Use of our framework does not require recompilation of the simulation program. The modular structure allows the flexible implementation of further sampling methods or physics engines and creates a basis for objective comparison of different sampling algorithms.     

Using organizational influence processes to overcome IS implementation barriers: lessons from a longitudinal case study of SPI implementation

A fundamental tenet of the information systems (IS) discipline holds that: (a) a lack of formal power and influence over the organization targeted for change, (b) weak support from top management, and (c) organizational memories of prior failures are barriers to implementation success. Our research, informed by organization influence, compellingly illustrates that such conditions do not necessarily doom a project to failure. In this paper, we present an analysis of how an IS implementation team designed and enacted a coordinated strategy of organizational influence to achieve implementation success despite these barriers. Our empirical analysis also found that technology implementation and change is largely an organizational influence process (OIP), and thus technical-rational approaches alone are inadequate for achieving success. Our findings offer managers important insights into how they can design and enact OIPs to effectively manage IS implementation. Further, we show how the theory of organizational influence can enhance understanding of IS implementation dynamics and advance the development of a theory of effective IS change agentry.