Attention and modality specific interference as determinants of short-term verbal and visual retention.

Conducted 2 experiments with a total of 210 undergraduates to investigate short-term retention of verbal and visual information as a function of interpolated activities, varying along the dimensions of attention and modality specific interference. Results show that retention losses due to competing attention demands were comparable in verbal and visual coding conditions, regardless of the modality of the interpolated activity. In addition, retention losses were larger when the same modality was involved in processing the memory and interpolated tasks. Results demonstrate a clear separation of short-term losses due to (a) attention diversion, and (b) modality specific interference, with attention diversion accounting for a larger part of total retention losses. It is proposed that the maintenance of information for short intervals relies on the availability of central attentional processes, with modality specific coding processes determining the most appropriate coding mode for a given stimulus situation. (French summary) (31 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Quality control of beer using high-resolution nuclear magnetic resonance spectroscopy and multivariate analysis

High-resolution nuclear magnetic resonance (NMR) spectroscopy is introduced for the quality control and authenticity assessment of beer in official food control. Measurements were performed using a 400-MHz NMR spectrometer using flow injection technology for automatic sample changing. Only degassing and addition of buffer (pH 5.6 in D₂O for locking and 0.1% TSP for referencing) is required to prepare the beer samples. Differences in the spectral profiles of beers varying in type and origin were studied by principal component analysis (PCA), considering the spectrum to be a characteristic fingerprint. For the first time, the high throughput of a Flow-Injection NMR system allowed a comprehensive database of beer spectra for PCA classification to be established efficiently. Beers made with barley malt could be distinguished from those made with wheat malt. Clustering of beers from the same brewing sites was observed, as well as significant discrimination of beers with deteriorated quality. Using the partial least squares (PLS) method to correlate NMR spectra with results from reference methods, models for calculating the original gravity, ethanol and lactic acid were established. The results obtained suggest that NMR is a useful tool in the quality control of beer samples, since quantitative determination of essential compounds as well as chemometric classification are simultaneously possible. Compared to conventional methods, ¹H NMR spectroscopy is faster and requires simpler sample preparation.     

Discrete event simulation for exploring strategies: an urban water management case

This paper presents a model structure aimed at offering an overview of the various elements of a strategy and exploring their multidimensional effects through time in an efficient way. It treats a strategy as a set of discrete events planned to achieve a certain strategic goal and develops a new form of causal networks as an interfacing component between decision makers and environment models, e.g., life cycle inventory and material flow models. The causal network receives a strategic plan as input in a discrete manner and then outputs the updated parameter sets to the subsequent environmental models. Accordingly, the potential dynamic evolution of environmental systems caused by various strategies can be stepwise simulated. It enables a way to incorporate discontinuous change in models for environmental strategy analysis, and enhances the interpretability and extendibility of a complex model by its cellular constructs. It is exemplified using an urban water management case in Kunming, a major city in Southwest China. By utilizing the presented method, the case study modeled the cross-scale interdependencies of the urban drainage system and regional water balance systems, and evaluated the effectiveness of various strategies for improving the situation of Dianchi Lake.     

Exploring temporal variations of oxygen saturation constants of nitrifying bacteria

Activated sludge models (ASM) are generally accepted as state-of-the-art in modeling wastewater treatment plants. In this paper, we assess the temporal variability of an ASM parameter-the oxygen half-saturation constant of autotrophic bacteria (K(O),(AUT)). A series of respirometric experiments is performed for conventional activated sludge and sludge from a membrane bioreactor. K(O) values are estimated for both ammonium-oxidizing and nitrite-oxidizing bacteria. For parameter estimation, the Monod kinetic model structure is extended by a sensor model. Still remaining systematic deviations between data and model are considered by a thorough residual analysis: (1) uncertainty estimates of K(O) are corrected to reflect model structure deficiencies and (2) the inter-experimental cross-correlation of residuals is taken into account to assess temporal changes. We conclude that K(O),(AUT) is a time variable parameter and should be considered accordingly.     

Porous cordierite-based ceramics processed by starch consolidation casting – Microstructure and high-temperature mechanical behavior

Porous cordierite-based ceramics with different microstructural features and mechanical behavior were formed by starch consolidation casting (SCC) using native potato and corn starches and sintered at 1275, 1300 and 1330 °C. The composition and microstructure of the ceramic materials were investigated via quantitative phase analysis using X-ray diffraction (with Rietveld refinement), the Archimedes method, mercury porosimetry, scanning electron microscopy and optical microscopy with stereology-based image analysis. The mechanical behavior of samples was evaluated by diametral compression tests at room temperature, 1000 and 1100 °C. The type of starch used and the sintering temperatures were the main factors determining the characteristics of the developed porous microstructures. Materials prepared with corn starch achieved the lowest porosity and the lowest values of mean chord length, mean pore distance and pore throat size. Because of these features, these materials thus presented, in general, higher values of apparent Young's modulus, elastic limit and mechanical strength than those prepared with potato starch. Despite the presence of a silicate glassy phase, both porous materials, mainly those prepared with corn starch, still enhanced the basic mechanical properties at high temperature, in particular, the mechanical strength and the apparent Young's modulus due to the special combination of the porous microstructure features.     

Compression behavior of pulp fiber networks

The forced compression behavior of random 3D and 2D pulp fiber networks is investigated. Existing theories are found to describe well the evolution of packing stress with fiber volume fraction for the pulp networks. It was moreover found that the packing behavior of an initially random 3D network of pulp fibers does not go through a transition to a 2D network packing behavior as it is compressed. Rather, the fibers exhibit localized collapse at contact points, a result of the hollow nature of the pulp fibers. The implications of this phenomena on the overall packing response was further examined by means of compression tests performed on a series of representative tubes of varying wall thickness. This analysis allowed determining the pressure range within which localized fiber buckling takes place.     

Detection of open or closed porosity in low-κ dielectrics by solvent diffusion

The presence of open porosity in a porous interlayer dielectric (ILD) can seriously degrade the ultimate performance and reliability of a device. A simple method for detecting the open porosity in ILDs would facilitate the design of materials with pore morphologies compatible with the required specifications of a particular device. The measurement of effective diffusion coefficients in a low-κ ILD over a range of porosities is shown to permit the detection of open porosity. An example illustrating the simplicity of this method is presented using toluene solvent in a well-characterized porous organosilicate material. The result using this method is consistent with available data in the literature.     

Diabetes research in South Carolina: past, present, and future

Medical investigators in South Carolina have been on the "cutting edge" of diabetes research for a number of decades. Despite this fact, our state ranks second in the nation in diabetes prevalence, and diabetes complications are more severe here than anywhere else. It is from the efforts of these investigators that our hope for a brighter future comes. Through a concerted effort toward prevention, improvements in care, and investigation of the pathophysiology of diabetes and its complications, researchers may reduce the substantial burden of diabetes in our state and throughout the world.