Very low-frequency heart rate variability wave amplitude and sympathetic stimulation--characterization and modeling

The purpose of this study was to assess the relationship between very low-frequency heart rate variability (LFHR) wave amplitude and the degree of sympathetic stimulation. We developed a computerized system for the controlled increase of heart rate (HR) by isoproterenol (ISP), with which we obtained a series of stabilized HR levels in conscious freely moving rats. We found that LFHR amplitude rises gradually as a function of the average HR for each level until it reaches a point where additional increases in average HR are associated with gradual decrease in LFHR amplitude. We successfully built and fitted a model of LFHR amplitude to the experimental results. The fact that our model fits the experimental data well may suggest a possible relationship between our LFHR amplitude findings and the basic physiologic properties of the HR-ISP system inherent in our model.     

A reinforcement learning approach to autonomous decision-making in smart electricity markets

The vision of a Smart Electric Grid relies critically on substantial advances in intelligent decentralized control mechanisms. We propose a novel class of autonomous broker agents for retail electricity trading that can operate in a wide range of Smart Electricity Markets, and that are capable of deriving long-term, profit-maximizing policies. Our brokers use Reinforcement Learning with function approximation, they can accommodate arbitrary economic signals from their environments, and they learn efficiently over the large state spaces resulting from these signals. We show how feature selection and regularization can be leveraged to automatically optimize brokers for particular market conditions, and demonstrate the performance of our design in extensive experiments using real-world energy market data.     

Correlation of clinical characteristics and small bowel histopathology in celiac disease

The reversible hearing loss in the nonoperated ear noted by patients after ear surgery remains unexplained. This study proposes that this hearing loss is caused by drill noise conducted to the nonoperated ear by vibrations of the intact skull. This noise exposure results in dysfunction of the outer hair cells, which may produce a temporary hearing loss. Estimations of outer hair cell function in the nonoperated ear were made by recording the change in amplitude of the distortion-product otoacoustic emissions before and during ear surgery. Reversible drill-related outer hair cell dysfunction was seen in 2 of 12 cases. The changes in outer hair cell function and their clinical implications are discussed.     

Conversion of halophilic algae into extractable oil. 2. Pyrolysis of proteins

The pyrolysis reactions with different solvents and reagents on different proteins, e.g., albumin, soyaprotein, lysozyme and algae-protein, show that there are no significant differences between the behaviour of proteins under those conditions. The reactions yield rather low conversions in the presence of water in spite of the existence of carbonates and catalysts, e.g. nickel sulphate. The presence of benzene improves the yield and the presence of a mixture of K-Mg-Mn salts is beneficial for such a reaction. The nitrogen content of liquid oil decreases in the presence of carbonates and other catalysts. The maximum amount of protein converted into liquid oil was 27% by weight for algae-proteins containing 5.7 wt% nitrogen. The existence of impurities does not affect the yield which is similar to the one obtained from pure proteinic compounds. The behaviour of the proteins under different temperatures and in various reaction mixtures is very similar to that found with algae.     

Evidence for 1La, 1Lb Dual State Emission in 1-naphthol and 1-methoxynaphthalene Fluorescence in Liquid Solutions

The steady-state fluorescence spectra of 1-methoxynaphthalene and 1-naphthol were measured in pure organic solvents and in binary mixtures of water and several organic solvents. The 1-isomers exhibited a much larger fluorescence Stokes-shift than the corresponding 2-isomers. The emission spectra of 1-methoxynaphthalene and 1-naphthol in pure nonpolar organic solvents exhibited roughly the same structured spectral features, while the fluorescence spectra in water and formamide exhibited much broader red-shifted and less structured spectral features. In accord with previous observations, we attribute these spectral changes to two emitting states, ¹L_b and ¹L_a, whose relative fluorescence intensities are sensitive to solvent polarity. Our analysis of the fluorescence spectra of 1-naphthol and 1-methoxynaphthalene by Pekarian functions have demonstrated that the ¹L_a state becomes the dominant emitting state in polar solvents. In addition, the ¹L_a state was found to be further stabilized in hydrogen-bond-donating solvents. In contrast to previous suggestions, the onset of the excited-state proton transfer reaction from 1-naphthol occurred at higher solvent polarities than those required for the establishment of a dominantly ¹L_a emitting state.     

A New Two-Three-Phase Voltage-Controlled Oscillator

The initial aim of the work has been the development of an inexpensive quadrature oscillator which can operate as a rapidly responding voltage-controlled oscillator (VCO) in two phases. Such rapid operation in quadrature is needed in association with quickly operating phase-locked loops for frequency synthesizers and similar applications. Other applications, where the relatively large speed is not essential, but where the phase shifts between various outputs should be precise, are mentioned in concluding this section. The electronic realization is made relatively cheap by proposing a replacement of the instantaneous amplitude measuring operation of square and sum (x2 + y2) (associated in the process of amplitude stabilization) by an operation of three-phase rectification. This leads to the construction of a versatile instrument which generates three-phase signals as well as two-phase signals (the two-phase signals are both sinewaves in quadrature and also square waves in quadrature). All these waveforms are capable of participating in the system performance as a VCO at a relatively large rate of frequency changes. A reversal in the order of phases when the frequency-control voltage crosses zero is also exhibited. This is needed in applications in industrial and power electronics. Our main aim now is to use the instrument in association with a precisely stabilized quickly responding cyclo-converter. Other possible applications of the instrument are in the field of precise measurements (for example, in the detection of signals by lock-in amplification there exists a frequent need for quadrature operation) and in telecommunication.     

Graded-index silver chlorobromide fibers for the mid-infrared

We have developed and characterized graded-index optical fibers for the mid-IR spectral range, based on silver chlorobromide (AgClBr) crystals. A preform was fabricated by inserting a cylindrical rod made of AgCl(0.1)Br(0.9) into a tube made of AgCl(0.9)Br(0.1). The preform was heated in an oven, causing diffusion of Cl into the outer layer of the rod, thus reducing its index of refraction. The rod was removed from the tube and was then extruded through a die to form a graded-index fiber. Such a fiber was analyzed, investigated, and compared with a step-index fiber made of AgClBr. The attenuation of a 0.9-mm-diameter graded-index fiber was found to be 2.4 dB/m, and the attenuation of a 1.2-mm-diameter graded-index fiber was 4 dB/m at 10.6 microm.