Bluetooth Inquiry Time Characterization and Selection

The Bluetooth discovery process requires use of the inquiry substate which not only consumes significant power, but prevents normal data traffic flow and simultaneously acts as a potential noise source for neighboring networks. Therefore, the inquiry substate dwell time should be limited to discovering an acceptable number of neighboring devices. Although an estimate of the probability density function of the time to discover scanning devices is straightforward, the complex temporal and spectral interactions between two devices make precise inquiry time characterization difficult. We characterize these interactions and derive detailed analytical expressions for the probability distribution of the inquiry time for a Bluetooth-enabled device that follows v1.1 of the Bluetooth specification and uses the default 11.25 ms inquiry scan window that opens every 1.28 s. Subsequently, we show a single inquirer will locate 99 percent of all scanning devices within transmission range in 5.12 seconds rather than the 10.24 s recommended in the specification. Using specification v1.2, we show that the inquiry time can be reduced to 3.84 seconds and 1.28 seconds using the standard and interlaced inquiry scan modes, respectively. Substantial inquiry time reduction results in reduced power requirements and increased throughput by increasing data traffic and reducing interference with neighboring piconets. Our results are validated via comparison with existing simulation models and measurement studies. The models used to derive the distribution also lend themselves to characterizing the discovery time with variations in the discovery process.     

Involvement of double-stranded RNA-activated protein kinase in the synergistic activation of nuclear factor-kappaB by tumor necrosis factor-alpha and gamma-interferon in preneuronal cells

Tumor necrosis factor-alpha (TNF-alpha) and gamma-interferon (IFN-gamma) cooperate during a variety of biological responses and ultimately synergistically enhance the expression of genes involved in immune and inflammatory responses. Recently, we demonstrated that IFN-gamma can significantly potentiate TNF-alpha-induced nuclear factor (NF)-kappaB nuclear translocation in neuronal derived and endothelial cell lines. The mechanism by which these two cytokines exert their synergistic effect on NF-kappaB involves the de novo degradation of the NF-kappaB inhibitor, IkappaBbeta. The double-stranded RNA-dependent kinase PKR is IFN-inducible and has been implicated in the activation of NF-kappaB; therefore, we examined the possibility that PKR may play a role in the synergistic activation of NF-kappaB during TNF-alpha/IFN-gamma cotreatment. The PKR inhibitor 2-aminopurine (2-AP) inhibited TNF-alpha/IFN-gamma-induced NF-kappaB nuclear translocation in neuronal derived cells but not in endothelial cells. The induced degradation of IkappaBbeta, which is normally observed upon TNF-alpha/IFN-gamma cotreatment, was blocked completely by 2-AP in neuronal derived cells. Also, 2-AP treatment or overexpression of a catalytically inactive PKR inhibited the TNF-alpha/IFN-gamma-induced synergistic activation of kappaB-dependent gene expression. Our results suggest that the signal generated by IFN-gamma during TNF-alpha/IFN-gamma cotreatment may require PKR to elicit enhanced NF-kappaB activity, and this signal may affect the stability of the IkappaBbeta protein.     

Consumer Perception of Cultured Yellow Perch (Perca flavescens) and Its Market Competitors

ABSTRACT:  Aquaculturists are concerned with performance of cultured yellow perch against its wild-caught market competitors. In this study, consumer perception of cultured yellow perch was compared to that of wild-caught walleye, ocean perch, and zander. In 2 experiments, species were ranked for preference, rated for liking, and rated for degree of difference from a reference (cultured perch). Results were analyzed using Friedman's analysis of ranks, analysis of variance, and method of maximum likelihood. In Experiment 1 ( n = 50), there was no significant difference in preference or liking, and all wild-caught species were significantly different from the reference. In Experiment 2 ( n = 68), the species were trimmed to the same thickness for a more fair comparison of these species. Cultured yellow perch was equally preferred to all species but was rated significantly higher than walleye in overall liking. In addition, ocean perch and walleye were found to be significantly different from cultured perch, while zander was not.     

Distribution load flow methods for shipboard power systems

With the recent initiatives to modernize large ship power systems, ship builders are integrating technologies with the aim of an all-electric energy system. New control strategies utilizing distribution automation and network reconfiguration provide greater flexibility, reliability, and quality of service. These automated controls require efficient and accurate load flow solutions. A critique of classical and distribution power-flow methods is conducted for shipboard distribution automation. Three classical radial-network power-flow methods are reviewed. A modification of the forward-backward sweep method is presented, which enhances the computation time and solution convergence. Comparative tests are conducted on a new benchmark test system of a ship's distribution network. The results demonstrate that the modified forward-backward sweep method succeeds in being the fastest method with good convergence on networks with low X/R ratios.     

Self-reported chemical sensitivity and wartime chemical exposures in Gulf War veterans with and without decreased global health ratings

BACKGROUND: The appetite-suppressant drug fenfluramine, usually given in combination with phentermine, has been reported to be associated with cardiac valvular regurgitation. Concern has been raised that the d-enantiomer of fenfluramine, dexfenfluramine, may also cause this problem. We were able to study the question by modifying an ongoing trial comparing dexfenfluramine with regular dexfenfluramine and placebo. METHODS: We modified our randomized, double-blind, placebo-controlled study of dexfenfluramine to include echocardiographic examinations of 1072 overweight patients within a median of one month after the discontinuation of treatment. The patients (approximately 80 percent of whom were women) had been randomly assigned to receive dexfenfluramine (366 patients), investigational sustained-release dexfenfluramine (352 patients), or placebo (354 patients). The average duration of treatment was 71 to 72 days in each of the three groups. Echocardiograms were assessed in a blinded fashion. RESULTS: When all degrees of valvular regurgitation were considered and when the two dexfenfluramine groups were combined, there was a higher prevalence of any degree of aortic regurgitation (17.0 percent vs. 11.8 percent, P=0.03) and any degree of mitral regurgitation (61.4 percent vs. 54.4 percent, P=0.01) in the active-treatment groups than in the placebo group. These differences were primarily due to a higher prevalence of physiologic, trace, or mild regurgitation. Analyses that used the criteria of the Food and Drug Administration for aortic regurgitation of mild or greater severity and mitral regurgitation of moderate or greater severity found no statistically significant difference among the groups (P=0.14 to 0.75). These analyses showed that aortic regurgitation of mild or greater severity occurred in 5.0 percent of the patients in the dexfenfluramine group, 5.8 percent of those in the sustained-release dexfenfluramine group, 5.4 percent of those in the two active-treatment groups combined, and 3.6 percent of those in the placebo group. Mitral regurgitation of moderate or greater severity occurred in 1.7, 1.8, 1.8, and 1.2 percent, respectively. Aortic regurgitation of mild or greater severity, mitral regurgitation of moderate or greater severity, or both occurred in 6.5 percent, 7.3 percent, 6.9 percent, and 4.5 percent, respectively. CONCLUSIONS: The increased prevalence of aortic and mitral regurgitation in patients treated with dexfenfluramine was small, and the degree of regurgitation was usually classified as physiologic, trace, or mild. However, the duration of therapy was short, and whether therapy of longer duration would yield the same or different results is not known.     

Hydrolytic treatment of cottonseed hulls

Conclusion 1. Alkaline solutions under the conditions of these experiments extracted from 7 to 50 percent of the lignin, depending upon the conditions of temperature and pressure. 2. Steam under pressure had little effect upon the composition of cottonseed hulls. 3. Dilute acids hydrolyzed more or less of the pentosans, depending upon temperature and pressure. 4. During both the steam and acid treatments there was a slight increase in the apparent lignin content. Food Research Division Contribution No. 430.     

Comparison of nipple projection with the modified double-opposing tab and star flaps

This study compared nipple projection after nipple reconstruction (following breast mound reconstruction) with either the modified double-opposing tab flap or the star flap. Areolar reconstruction and pigmentation of the nipple were achieved with tattooing. Nipple projection for 153 nipples was measured at least 6 months after the reconstruction, when projection was believed to have become stable. Mean follow-up was 2.27 years. In the 106 nipples reconstructed with modified double-opposing tab flaps, the mean projection was 2.4292 mm, while in the 47 nipples reconstructed with star flaps, the mean projection was 1.9681 mm (p = 0.021). We conclude that although both methods are effective, the modified double-opposing tab flap has slightly more projection after approximately 2 years. It is not known, however, whether this is because of reduced flap atrophy or longer initial projection by the modified double-opposing tab flap; further studies are ongoing.     

Proteins of the penicillin biosynthesis pathway

Two sequential steps are common to the biosynthesis of all penicillin-derived antibiotics: the reaction of three L-amino acids to give L-delta-(alpha-aminoadipoyl)-L-cysteinyl-D-valine, and the oxidation of this tripeptide to give isopenicillin N. Recent studies on the peptide synthetase and oxidase enzymes responsible for these steps have implications for the mechanisms and structures of related enzymes involved in a range of metabolic processes.