Following the trail: understanding information flow in the emergency department

A hospital emergency department (ED) is a complex cognitive work system. ED providers routinely create, process and share various kinds of information in their work. They may constantly transform information using technological artifacts such as an electronic patient information system. The functionality in the technology, however, limits their tasks and activities. So, they create their own artifacts (such as handwritten notes on a post-it note), to share and process information. The goal of the paper is to illustrate how health providers in EDs create, process, transform and share information to achieve work goals. We present the information trail model in the ED to illustrate various facets of information creation activity and generate insights for health information technology design.     

Measuring Software Screen Complexity: Relating Eye Tracking,Emotional Valence,and Subjective Ratings

Enterprise software pages, routinely used to conduct a variety of business-relevant tasks, must be clear and nonconfusing to experienced end users. A study was conducted to consider the impact of several page design factors (background gradient, font, and font size) on perceived ratings of page clarity, completion time, emotional valence (EV) from video, and several eye-tracking parameters. Twenty professional managers each completed 25 tasks on enterprise web pages designed with specific combinations of these factors. Highly rated pages had Tahoma and Larger fonts, compared to Calibri and Smaller fonts. The Gradient background did not influence ratings but did increase the search area and completion time. Although EV was not a sensitive measure across tasks, it was influenced by font differences in the first few seconds of page presentation. Overall, the use of background gradient was not supported, but both Tahoma and Larger fonts were supported for these enterprise pages.     

A description of phase inversion behaviour in agitated liquid-liquid dispersions under the influence of the Marangoni effect

The influence of the Marangoni effect on phase inversion behaviour is examined by integrating a microscopic study of the drop coalescence process, in which thin film drainage in the presence of insoluble surfactant occurs, into a macroscopic phase inversion model which has been developed previously using a Monte Carlo technique. This is achieved via an immobility factor, obtained from a comparison of the film drainage times for surfactant-laden systems and surfactant-free systems as a function of the drop approach velocity, surface Péclet number, initial surfactant concentration and the Hamaker constant, which is then used to modify the coalescence probability in the phase inversion model. On the one hand, the results indicate that the Marangoni effect removes any influence that the viscosity ratio has on phase inversion due to immobilisation of the interface, thus shielding the flow in the film from the effects of the flow in the dispersed phase; the point at which phase inversion occurs therefore tends towards equivolume holdups with the addition of surfactant. On the other hand, when comparisons are made with pure systems in which surfactant is absent, the system is seen to be either stabilised or de-stabilised from inversion depending on the viscosity ratio of the system. This is attributed to the influence of surfactant on the dispersion morphologies on either side of the inversion (i.e. water-in-oil dispersions and oil-in-water dispersions) and depends on the dispersed phase holdup; the Marangoni effect is felt stronger when the dispersed phase holdup is low.     

Effects of dietary oils and methyl ethyl ketone peroxide onin vivo lipid peroxidation and antioxidants in rat heart and liver

Weanling male Sprague-Dawley rats were fed diets for four weeks which differed in their content of n−6 (corn oil; CO) and n−3 fatty acids (fish oil; FO), but were similar in their content of saturated and monounsaturated fatty acids and vitamin E. At the end of the four-week feeding period, each dietary group was subdivided into two groups. One group received a single placebo injection of α-tocopherol-stripped corn oil (TSCO); the other group received a single injection of the free radical generator, methyl ethyl ketone peroxide (MEKP), in TSCO. Twenty-four hours after injection, the effect of dietary oil and MEKP treatment on endogenous lipid peroxide (LPO) production (measured as methylene blue formed by the “Determiner LPO” assay), glutathione (GSH) and vitamin E content, and fatty acid composition of phosphatidylcholine and phosphatidylethanolamine in heart and liver from unfasted animals were measured. FO-fed rats had significantly heavier hearts and livers, increased levels of n−3 fatty acids in membrane phospholipids, and higher liver LPO levels than CO-fed rats. MEKP treatment resulted in significantly lower body weights and liver GSH levels. The data indicate that dietary n−3 fatty acids increase lipid peroxidation in liver somewhat more than in heart. The study also demonstrates that the effect of induced oxidative stress due to a single dose of MEKP on lipid peroxide formation and antioxidant status in tissues from unfasted animals was independent of the dietary oils.     

Isomerization Dynamics of Dicyanine A in n-Alcoholic Solution

The radiationless relaxation of dicyanine A molecules in n-alcohols methanol to butanol has been studied by picosecond fluorescence spectroscopy and time-resolved nonlinear spectroscopy. The fluorescence decay rates have been measured as a function of viscosity, temperature, and fluorescence wavelength. It is shown that the wavelength dependence can be explained by coexistence of two ground-state conformers. The intrinsic activation barrier for the nonradiative decay from the excited surface is very small, much less than 1 kcal/mol. In a particular solvent the time constants of the nonradiative relaxation show a linear dependence on the variation of viscosity. The experimental data are discussed in relation to the BFO theory (Bagchi, B.; Fleming, G.R.; Oxtoby, D.W. J. Chem. Phys. 1983, 78: 7375).     

A biomarker of n−3 compliance in patients taking fish oil for rheumatoid arthritis

Dietary fish oil supplements have been shown to have benefits in rheumatoid arthritis (RA), other inflammatory diseases, and in cardiovascular disease. As with any medical advice, variability will exist with regard to adherence and consequent biochemical or pharmacophysiologic effects. The aim was to explore the utility of plasma phospholipid EPA as a measure of n−3 PUFA intake and response to standardized therapeutic advice given in an outpatient or office practice setting, to increase dietary n−3 PUFA, including a fish oil supplement. Patients with early RA were given verbal and written advice to alter their dietary n−3 PUFA intake, including ingestion of 20 mL of bottled fish oil on juice daily. The advice included instructions to increase n−3 PUFA and to avoid foods rich in n−6 PUFA. Every 3 mon, blood samples were obtained for analysis of plasma phospholipid FA. Plasma phospholipid EPA was used as the primary index of n−3 PUFA intake. A diverse response was seen, with about one-third of patients achieving a substantial elevation of plasma phospholipid EPA over the 12-mon study period. A third had little change, with the remainder achieving intermediate levels. Data obtained longitudinally from individual patients indicated that substantial elevations of EPA (>5% total plasma phospholipid FA) could be maintained for more than 3 yr. Plasma phospholipid EPA is a convenient measure of adherence to advice to take a dietary n−3 PUFA-rich fish oil supplement. This measure may prove a useful adjunct to intention to treat analyses in determining the effect of dietary fish oil supplements on long-term outcomes in arthritis and other chronic inflammatory diseases. It may also provide a guide to the effectiveness of therapeutic and preventive messages designed to increase n−3 PUFA intake.     

Effect of fish oil on the fatty acid composition of human milk and maternal and infant erythrocytes

To examine the effect of fish oil supplementation on the fatty acid (FA) composition of human milk and maternal and infant erythrocytes, five lactating women were supplemented with 6 g of fish oil daily for 21d. Usual maternal diets contained 1,147 mg of total n−3 FA, with 120 mg from very long-chain (>C₁₈) n−3 FA. Supplementation increased dietary levels to 3,092 mg of total n−3 FA and 2,006 mg of very long-chain n−3 FA. Milk samples were collected daily, prior to fish oil ingestion, and at 4-h intervals on days 1, 7, 14 and 21. Milk n−3 FA content increased within 8 h and reached steady state levels within one week. The n−6 fatty acid content decreased. Erythrocyte eicosapentaenoic acid content increased from 0.24% to 1.4% (P<0.01) in mothers and from 0.11% to 0.70% (P<0.05) in infants. Docosapentaenoic acid increased from 1.4% to 2.2% (P<0.05) in mothers and from 0.30% to 0.78% (P<0.01) in infants. There was no significant change in docosahexaenoic acid or n−6 fatty acid content. Maternal platelet aggregation responses were variable. No differences in milk or plasma tocopherol levels were noted. Based on a paper presented at the Symposium on Milk Lipids held at the AOCS Annual Meeting, Baltimore, MD, April 1990.     

The lipids of the oriental hornet,Vespa orientalis F.

Analysis of the hornet’s hemolymph revealed the presence of C₁₆ and C₁₈ fatty acids (70%), which were accompanied by minor quantities (ranging from 0.1% to 0.6%) of the following acids: C_10∶0, C_11∶0, C_12∶0, C_13∶0, C_14∶0, C_15∶0, C_16∶0, and C_17∶0. The hemolymph of the queen larvae contained more C_18∶1 than the hemolymph of the worker larvae, and the percentage of C_16∶1 was higher in the fat body and the midgut than in the hemolymph. The significance of these results is discussed.     

Mechanical analysis of hollow fiber membrane integrity in water reuse applications

In order to gain insight into membrane fiber failure (i.e., loss of integrity), properties of five hollow fiber membranes and four hollow fiber modules were evaluated. Specifically, membrane material, membrane symmetry, fiber modulus of elasticity, fiber diameter and thickness, module potting technique, module flow pattern (inside-out or outside-in), and coliform breakthrough were investigated. The approach combined evaluation of the above properties with mathematical modeling of structure-fluid interactions to comprehensively evaluate the properties most important for maintaining hollow fiber membrane integrity. Tensile strength testing revealed that the strongest fiber was an asymmetric polyacrylonitrile membrane fiber. The weakest fiber was a symmetric polyethylene membrane fiber. Pilot plant testing on the four membrane modules revealed that membrane symmetry may be a more important factor than potting technique for hollow fiber integrity. Results from the SEM and tensile testing were used as input to a finite element analysis model used to evaluate time-dependent structure-fluid interactions. It was found that additional stresses at the juncture of the potting material and the hollow fiber membranes exist. These stresses likely lead to the formation of fractures.     

Barium Metaplumbate Ceramic Electrodes for Ceramic Capacitors

A novel approach to reduce electrode costs in ceramic capacitors is presented. Barium metaplumbate (BaPbO₃) was fired onto sintered commercial (Ba, Sr)TiO₃ disk capacitors as external electrodes. Samples were compared to disk capacitors of the same composition with electrodes made of sputtered gold and air-dried silver. The ceramic electrode led to substantial changes in the insulation resistance and dc breakdown strengths, but other properties remained the same. The feasibility of using BaPbO₃ electrodes strongly depends on chemical reactions between the electrode and dielectric.