Chaos communications-principles, schemes, and system analysis

This paper provides a comprehensive overview of chaotic communication methods and schemes with emphasis on digital schemes. Starting from general demands for communications, the general communication system structure is introduced. From this basic viewpoint, different classical and chaotic modulation and demodulation methods are treated and classified. For the performance analysis and comparison, a discrete-time statistical calculus is developed and applied to chaotic signal processing schemes. Discrete-time baseband models are developed, which are suitable for a statistical performance analysis. Analysis results for various example systems are provided and compared. New decoder structures are proposed and included in the comparative studies     

Effects of temperature elevation and entrainment on heterotrophic uptake of [U-C]glutamic acid

The effect of temperature elevation and station passage on the heterotrophic uptake of glutamate in condenser cooling water was investigated at three Ontario Hydro generating stations. Glutamate uptake increased approx. 1.9 times with a 10°C rise in lakewater temperature providing the total (discharge) temperature did not exceed 30°C. Above 30°C inhibition of bacterioplankton activity was observed. Mechanical stress encountered during station passage resulted in a reduction of heterotrophic activity of approx. 57%. Temperature elevation and mechanical stress experienced during the once-through cooling process could be expected to result in a net increase in heterotrophic productivity, largely in peripheral areas of the effluent thermal plume and contiguous waters.     

Sex differences in fear of spiders.

Tested 60 female and 48 male undergraduates who scored high on a scale item measuring fear of spiders. In the presence of a live spider, women reported more subjective unpleasantness and tension than men and had higher heart rates. Women also displayed greater reluctance to be close to the spider. Analysis indicated that these differences were due to a sex-linked difference in fear. Results are discussed in terms of the origin and definition of different types of fears. (11 ref) (PsycINFO Database Record (c) 2010 APA, all rights reserved)     

Untersuchungen zur Polymerisation der Fettsäuren I. Einfluß der Reaktionsbedingungen auf den Verlauf des Polymerisationsprozesses

Investigations of the Polymerization of Fatty Acids I. An Influence of Reaction Conditions on the Course of Polymerization Process In the presented paper some technological conditions of the polymerization of rapeseed-oil fatty acids were studied. The temperature, water content and pressure had determinating influence on polymerization velocity when the bentonite type of catalyst was used. With respect to yield of dimeric fatty acids water content of 1 - 2 wt. % and pressure 0.4 - 0.6 MPa are the most favourable values. With temperature above 160 °C an increasing decarboxylation of fatty acids has taken place.     

Acetat- und Formiatgehalte im Splintholz der Kiefer

Ohne Zusammenfassung     

New polymer syntheses: 10. Syntheses of high molecular weight poly(4-hydroxybenzoate)s by bulk condensations of 4-hydroxybenzoic acids

The condensation of 4-hydroxybenzoic acid by means of various carboxylic acid anhydrides, acid chlorides and diphenylcarbonate has been investigated. All condensations were conducted in ‘one-pot procedures’. The average degrees of polymerization ($\text{DP}$) were determined by means of ¹H nuclear magnetic resonance (n.m.r.) spectroscopic end-group analyses. The bulk condensation of 4-hydroxybenzoic acid by means of acetic anhydride at temperatures between 320° and 350°C was found to be the simplest and least expensive procedure. Yields between 97 and 99% and $\text{DP}$ up to 300 were obtained in this way. Bulk condensations of purified acetoxybenzoic acid or condensations of 4-hydroxybenzoic acid with acetic anhydride in an inert solvent gave similar yields and $\text{DP}$. Also, the bulk condensations of 3,5-dimethyl-4-hydroxybenzoic acid, 3-methoxy-4-hydroxybenzoic acid, 3-chloro-4-hydroxybenzoic acid, 3,5-dichloro-4-hydroxybenzoic acid and 3,5-dibromo-4-hydroxybenzoic acid by means of acetic anhydride gave yields above 90%. However, the $\text{DP}$'s varied greatly with the nature of the substituents. ‘One-pot procedures’ using a variety of phosphorus derivatives as condensing reagents did not yield pure polyesters. The differential scanning calorimetry (d.s.c.) curves of the substituted poly(4-hydroxybenzoate)s do not show any endotherm, although X-ray diffraction measurements indicate a high degree of crystallinity. The thermogravimetric analyses demonstrate that the thermal stability depends largely on the synthetic procedure.     

Robust relative stability of time-invariant and time-varyinglattice filters

We consider the relative stability of time-invariant and time-varying unnormalized lattice filters. First, we consider a set of lattice filters whose reflection parameters α_i obey |α_i|⩽δ_i and provide necessary and sufficient conditions on the δ_i that guarantee that each time-invariant lattice in the set has poles inside a circle of prescribed radius 1/ρ<1, i.e., is relatively stable with degree of stability ln ρ. We also show that the relative stability of the whole family is equivalent to the relative stability of a single filter obtained by fixing each α_i to δ_i and can be checked with only the real poles of this filter. Counterexamples are given to show that a number of properties that hold for stability of LTI Lattices do not apply to relative stability verification. Second, we give a diagonal Lyapunov matrix that is useful in checking the above pole condition. Finally, we consider the time-varying problem where the reflection coefficients vary in a region where the frozen transfer functions have poles with magnitude less than 1/ρ and provide bounds on their rate of variations that ensure that the zero input state solution of the time-varying lattice decays exponentially at a rate faster than 1/ρ₁>1/ρ     

Fluoxetine in depressed alcoholics. A double-blind, placebo-controlled trial

BACKGROUND: The selective serotonergic medication fluoxetine has demonstrated efficacy in the treatment of major depression and has suggested efficacy in the treatment of alcoholism. However, no completed trials with any selective serotonergic medication have been reported in patients who display both major depression and alcoholism, despite previous observations that both depression and alcoholism are associated with low serotonergic functioning. METHODS: Fifty-one patients diagnosed as having comorbid major depressive disorder and alcohol dependence were randomized to receive fluoxetine (n = 25) or placebo (n = 26) in a 12-week, double-blind, parallel-group trial. Weekly ratings of depression and alcohol consumption were obtained throughout the 12-week course of the study. RESULTS: The improvement in depressive symptoms during the medication trial was significantly greater in the fluoxetine group than in the placebo group. Total alcohol consumption during the trial was significantly lower in the fluoxetine group than in the placebo group. CONCLUSIONS: Fluoxetine is effective in reducing the depressive symptoms and the alcohol consumption of patients with comorbid major depressive disorder and alcohol dependence. It is unknown whether these results generalize to the treatment of less depressed and less suicidal alcoholics.