The properties of high-current high-pressure discharges

The properties of high-current high-pressure gas discharges (I = 60 kA, p = 1 atm, τ_1/2 = 1.6 ms, r ～ 10 cm) just before the end of the discharge are investigated experimentally. It is shown that the anomalously high rate of gas cooling after the current is switched off is related to the turbulent hydrodynamic processes induced by the Rayleigh-Taylor instability at the discharge boundary in the stage of volume radiative cooling of the discharge channel. The turbulent thermal conductivity is estimated using experimental data on the recovery of the electric strength of the discharge gap.     

Formation of the dysentery epidemic process in three small towns]

Data are presented concerning the epidemiological analysis of Sonnei dysentery outbreaks in three towns connected by common nutrition and water supply. The epidemic processes in these populated localites were strongly interrelated. Possibilities of the effect of the water factor on the extent of Sonnei dysentery incidence were studied as well. The results of studies led to the conclusion on the presence of numerous action forms of the water factor which should be taken into consideration in carrying out prophylactic and antiepidemic measures in Sonnei dysentery.     

The epidemiology of rotavirus gastroenteritis

The materials, comprehensively characterizing the water outbreaks of gastroenteritis with its etiology established and its clinico-epidemiological interpretation made, are presented. Along with other data, the water nature of the outbreak was verified by the detection of rotavirus antigen, made in the enzyme immunoassay, not only in patients, but also in water samples from the surface water source and from sewage. To isolate the infective agent from environmental objects, bentonite, a mineral sorbent, has been used for the first time. The authors believe that the water route plays the main (primary) role in the spread of rotavirus gastroenteritis and the adult population is the main reservoir of this infection. The fact the disease is registered mainly among younger age groups of the child population reflects only the maximum manifestation of rotavirus infection among these age groups.     

Robustness of a Neural Network Model for Differencing

A neural network, originally proposed as a model for nuclei in the auditory brainstem, uses gradients of cell thresholds to reliably compute the difference of inputs over wide input ranges. The encoding of difference is linear even though the individual components of the network are finite, saturating, nonlinear devices highly dependent on input level. Theorems are proven that explain the linear dependence of network output on difference and that show the robustness of the network to perturbations of the threshold gradients. There is some evidence that the network exists in the neural tissue of the auditory brainstem.