An algorithm used for ventricular fibrillation detection without interrupting chest compression

Ventricular fibrillation (VF) is the primary arrhythmic event in the majority of patients suffering from sudden cardiac arrest. Attention has been focused on this particular rhythm since it is recognized that prompt therapy, especially electrical defibrillation, may lead to a successful outcome. However, current versions of automated external defibrillators (AEDs) mandate repetitive interruptions of chest compression for rhythm analyses since artifacts produced by chest compression during cardiopulmonary resuscitation (CPR) preclude reliable electrocardiographic (ECG) rhythm analysis. Yet, repetitive interruptions in chest compression are detrimental to the success of defibrillation. The capability for rhythm analysis without requiring "hands-off" intervals will allow for more effective resuscitation. In this paper, a novel continuous-wavelet-transformation-based morphology consistency evaluation algorithm was developed for the detection of disorganized VF from organized sinus rhythm (SR) without interrupting the ongoing chest compression. The performance of this method was evaluated on both uncorrupted and corrupted ECG signals recorded from AEDs obtained from out-of-hospital victims of cardiac arrest. A total of 232 patients and 31,092 episodes of either VF or SR were accessed, in which 8195 episodes were corrupted by artifacts produced by chest compressions. We also compared the performance of this method with three other established algorithms, including VF filter, spectrum analysis, and complexity measurement. Even though there was a modest decrease in specificity and accuracy when chest compression artifact was present, the performance of this method was still superior to other reported methods for VF detection during uninterrupted CPR.     

Cray/Blitz—1984 chess champion

The chess program “Cray Blitz” is the current World Computer Chess Champion and North American Computer Chess Champion (ACM). The program has also played in human chess tournaments and is a chess master. At speed chess, where its ability to perform very accurate analysis is particularly important, it has maintained a performance rating of over 2600 for the past two years. This indicates that at speed chess, the program is one of the top players, electronic or human, in the world. It is currently running on a Cray XMP-48 computer system and has been designed around the parallelism that the XMP architecture provides.     

Noninvasive Determination of Central Blood Pressure by Impedance Plethysmography

A new algorithm based on impedance plethysmography provides reliable determinations, on an experimental basis, of arterial blood pressure. Signals over the brachial artery are picked up by four Velcro-type electrodes attached to the skinward side of a regular blood pressure cuff. Mathematical formulas are used to define those impedance pulses that correspond to systolic, diastolic, and mean arterial blood pressure values. The envelope of the impedance pulses recorded during cuff deflation can be defined by linear regressions, function of just one normalized independent variable, which is the ratio between the amplitude of the pulse with maximum amplitude and of the amplitude of the pulses with constant amplitude. These linear regressions are assumed to be universally applicable, the influence of individual anatomic variations having been eliminated by the use of a normalized variable. The results of this study prove that the variable pulse amplitude obtained during a cuff deflation is a quantifiable reaction of the circulatory system to arterial constriction.     

In vitro study of intestinal lipolysis using pH-stat and gas chromatography

Developing healthy products requires in-depth knowledge of digestion. This study focuses on lipid digestion in relation to emulsion properties typically followed by pH-stat. Although this is a fast and easy method to follow the overall digestion, it provides no details on lipid digestion products. Thus, the aims of the present study were to use gas chromatography (GC) to determine all products present during lipolysis, i.e. monoglycerides (MG), diglycerides (DG) and triglycerides (TG), and to compare this method with the pH-stat method for free fatty acids (FFA). Fine, medium and coarse emulsions stabilized with two different emulsifiers (whey protein isolate (WPI) or gum arabic) were digested under in vitro intestinal conditions. Although the amount of FFA increased for both methods for WPI stabilized emulsions, the amount of FFA was 2-3 times higher when determined by GC compared with pH-stat. GC analysis showed decreasing amounts of MG and DG with increasing droplet size for both emulsions. Molar ratios of FFA/DG and MG/DG were twofold higher for WPI than for gum arabic stabilized emulsions. This indicates that the total production of lipolytic products (i.e. FFA + MG + DG) depends on the droplet size and the emulsifier but their proportions only depend on the emulsifier. Although pH-stat provides a fast measure of FFA release, it is influenced by the emulsifier type at the oil-water interface and therefore care should be taken when interpreting pH-stat results. We suggest combining this method with GC for accurate FFA determination and further evaluation of all lipolytic products.     

Modeling the thermal inactivation kinetics of heat-resistant Salmonella Enteritidis and Oranienburg in 10 percent salted liquid egg yolk

There is no suitable model for predicting thermal inactivation kinetics of Salmonella spp. for many types of liquid egg products, including salted liquid egg yolk, for use in updating U.S. Department of Agriculture (USDA) pasteurization guidelines. This is because, in part, of the variations in Salmonella strains and the changes in the processing of liquid egg products over the past 40 years. The objectives of the present study were to determine the thermal inactivation kinetics and to create a general thermal inactivation kinetics model that can be used for estimating log reductions of salmonellae in 10% salted liquid egg yolk for temperatures between 62.2 and 69°C. This model can be used by processors to help ensure adequate pasteurization. This was accomplished by studying the inactivation kinetics of a three-strain composite of heat-resistant Salmonella serovars Enteritidis and Oranienburg, inoculated into commercially processed 10% salted liquid egg yolk. The survival curves were convex, with asymptotic D-values. From these curves, a general model was developed to predict log reductions for given times at specified temperatures. For example, at a temperature of 67.3°C (153.1°F) for 3.5 min, our model predicts a 5-log reduction would be obtained, whereas with the current USDA minimum required pasteurization regimen (63.33°C [146°F] for 3.5 min), our model predicts that a reduction of only 2.7 log would be obtained. The results of this study provide information that can be used by processors to aid in producing safe, pasteurized egg yolk products, and for satisfying USDA pasteurization performance standards and developing industry guidance.     

Volatile flavour components of malt extract

The Likens-Nickerson concurrent steam distillation-solvent extraction apparatus was used to obtain an essence from malt extract. The essence was submitted to combined gas chromatography-mass spectrometry (g.c.-m.s.), to examination by sulphurspecific and nitrogen-specific detectors, and to sensory evaluation of the components eluted from gas chromatographic capillary columns. Some 33 compounds were identified by direct examination by g.c.-m.s., another 14 by trapping and re-injection, which provides an efficient method of concentration, and a further six, which had not been previously identified due to interference from the solvent peak, by the use of charcoal adsorption traps. Results indicate that several compounds need to be combined to simulate malt flavour. The odour contributions of several components are discussed.     

Conditioned taste aversions and neophobia in rats with hippocampal lesions.

In Exp I extensive hippocampal lesions retarded, but did not prohibit, the conditioning of a strong taste aversion to physiological saline (the CS) in 16 male Holtzman albino rats when illness (the UCS) was induced by apomorphine injection 15 min following ingestion of the saline. In Exp II hippocampal lesions reduced the aversiveness of novelty in a drinking fluid for 21 thirsty Ss. It is suggested that the mild impairment of taste aversion learning in Ss with hippocampal lesions was not the result of destruction of mnemonic mechanisms that serve to span the long CS-UCS interval but rather that the reduced intensity of the aversion resulted from a lesion-altered neophobic disposition that weakened the saliency of the novel flavor CS. (51 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)