Diarrhea in young children associated with Escherichia coli non-O157 organisms that produce Shiga-like toxin

The aim of this study was to evaluate the way in which short-term protection declines and is eventually lost in preconditioning and to determine the efficacy of a second preconditioning at various reperfusion intervals. Male rabbits were divided into six groups. Forty-five minutes (sustained) ischemia followed by 120 minutes reperfusion was applied 60, 65, 70, 75, and 80 minutes after a 5 minute preconditioning (groups A, B, C, D, and E) and in a control group (F) after no preconditioning. The infarct to risk ratio (I/R) was 38.3 +/- 3.5% in group A, 46.0 +/- 7.8% in B, 61.6 +/- 9.7% in C, 68.1 +/- 4.2% in D, 64.5 +/- 7.8% in E, and 61.0 +/- 7.7% in F. Group A had a smaller I/R compared with groups C, D, E, and F (p < 0.05). In another series, groups G, H, and I were exposed to two 5-minute preconditioning stimuli, separated, respectively, by 45, 60, and 75 minutes of reperfusion; 10 minutes after the last preconditioning, the animals were exposed to 45-minutes ischemia and 120 minutes reperfusion. Groups A and D (with the smaller and higher I/R ratio) were also incorporated into this protocol in order to compare the effect of the additional preconditioning with the single one. The I/R ratio was 25.4 +/- 8.5% in group G, 22.8 +/- 7.0% in group H, and 14.7 +/- 4.0% in group I (p = NS). Group D showed a higher I/R compared with groups G, A, and H (p < 0.01), and group I had a smaller I/R compared with groups A (p < 0.01) and D (p < 0.001). Cardioprotection after a first preconditioning declines gradually and is eventually lost. An additional preconditioning is always effective, and the longer the interval from the first preconditioning, the more potent is the effect.     

Evaluating design metrics on large-scale software

Design-quality metrics that are being developed for predicting the potential quality and complexity of the system being developed are discussed. The goal of the metrics is to provide timely design information that can guide a developer in producing a higher quality product. The metrics were tested on projects developed in a university setting with client partners in industry. To further validate the metrics, they were applied to professionally developed systems to test their predictive qualities. The results of applying two design metrics and a composite metric to data from a large-scale industrial project are presented     

Achieving synergy in collaborative education

Professional software engineering continues to face problems that involve large-scale (complex) software systems development. Such efforts typically require team collaboration over months, possibly years. Once implemented, the system must be maintained for sometimes decades. This development and maintenance life cycle requires not only technical knowledge and skills in software development, but also the knowledge and skills associated with software process. We believe the traditional computer science curriculum fails to consider this spectrum of needs. We also believe, however, that software engineering must use certain elements of the core knowledge and skills taught by computer scientists as its foundation. We describe lessons learned from the 10-year collaboration between Monmouth University and the Software Engineering Center of the US Army's CECOM (Communications Electronics Command). The center recruits electrical engineering and computer science graduates from academic institutions in the geographic regions surrounding its various installations to be part of its intern program; Monmouth University, in turn, incorporates the demands of the intern program in its Master of Science in software engineering curriculum     

Point of utilization power quality study results

A wide variety of electromagnetic phenomena occurring on AC power lines has been held responsible for literally billions of dollars per year in lost revenue. Information related to actual probability of occurrence of these power line deviations is presently limited. This paper describes the results of four years of point of utilization power quality monitoring at 112 North American locations. A quantity of 1057 site months of data collected between 1990 and 1994 was used in this assessment. The data indicate that the numbers of events occurring at typical locations may range from almost none, to thousands per month. The analysis results characterize several aspects of power quality related to the occurrence of low RMS events, high RMS events, transient events, and power interruptions (outages)     

Introducing computer tools into a first course in electricalengineering

At a school where engineering students have immediate access to a personal computer, it is important that they become familiar with that tool early in their studies. In introductory engineering courses it is also important that the students learn to perceive the computer as a tool and not as an end in itself. Achieving these goals requires a careful integration of computer usage into such courses by the instructors. In this paper we examine this issue in the context of a first course in electrical engineering that has been taught at the US Naval Academy, and we present specific examples of assignments we have used in our effort to accomplish these goals     

Data management and analysis for high-throughput DNA sequencingprojects

The rapid advances in molecular biology have begun to shift many of the bottlenecks in genome research from the laboratory to the data analysis facility. The pace at which this has occurred creates a situation in which software development always has to catch up with the flow of data. Since such large-scale processes were not anticipated, the analysis infrastructure has not been fully established. Furthermore, most systems that have been built were designed by the biologists who collected the data. More recently, computer scientists, mathematicians, and engineers have taken an interest in this problem. This has had a positive effect, since it has created a tight synergy between the informatics and the biology. Several principles affected the design of the system developed at TIGR. Each of the sample preparation, sequencing, and analysis steps had to be managed, scheduled, and tracked. This information had to be made readily available to those who needed it for carrying out their tasks. Different skill levels of the users had to be taken into account. The degree of human intervention at each step had to be evaluated and built into the design. A mixed processing environment of Macintosh and Unix platforms had to be integrated. Most importantly, the system had to save time, reduce error, and ensure uniformity of the analysis and quality of the results. In the authors' experience, the tools they have built work well because of their early decisions as to which systems to use for development. The authors settled on a robust relational database management system (Sybase) and a portable development environment (C, C++)     

Study of Desorption and Adsorption During Grain Aeration

One requirement in designing and operating and operating system is to minimize the moisture change in stored grain. Moisture transfer during the aeration process is generally believed to be caused by the partial pressure difference between water in grain and water in air (P₃-P₄). A mathematical model was developed for rough rice, which predicts the partial pressure difference under various grain and ambient conditions. Observations of moisture change over 10 aeration tests confirmed the good correlation between sorption phenomena and partial pressure differences. Studies indicated that air relative humidity, air temperature, grain temperature and grain moisture are significant factors influencing the partial pressure differences and, thus, affecting     

Structured genetic algorithm for robust H∞ controlsystems design

A structured genetic algorithm (SGA) approach is developed for robust controller design based on the concept of an H^∞ loop-shaping technique and the method of inequalities. Such an SGA is capable of simultaneously searching the orders and coefficients of the precompensator and postcompensator for the weighted plant. It is, therefore, not necessary to predefine the order of compensators as in usual practice. A multiple objective ranking approach is also incorporated so that the design criteria of extreme plants can be easily achieved. The effectiveness of such a technique is illustrated by a high-purity distillation column design example