Instability in a non-ohmic/ohmic fluid interface under a perpendicular electric field and unipolar injection

We set the equations for the linear electrohydrodynamic instability of an interface between two fluids, subjected to a perpendicular field and a unipolar charge injection. One of the fluids is modeled as being in non-ohmic regime (insulating), whereas the other is ohmic. A new interfacial instability mechanism is described, which may account for the Rose-window instability. The equations are analytically solved in the limit of long wavelength and neglecting the fluid motion. We show that this limit applies well to the case of an air-ohmic liquid interface. The applicability to a liquid-liquid interface is also analyzed

EPIDEMIOLOGICAL, CLINICAL AND LABORATORY PECULIARITIES OF AN EPIDEMIC OF ACUTE VIRAL HEPATITIS DURING 1990-1991 IN THE REGION OF VARNA

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AN ATTEMPT AT NOSOLOGICAL AND ETIOLOGICAL DIARRHEA SYNDROME DECODING IN PATIENTS WITH PRESUMED ENTERAL INFECTION

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Проепілептогенний ефект наночастинок срібла на моделі пентиленететразол-індукованого кіндлінгу

On the model of pentylenetetrazol (PTZ)-induced kindling in Wistar rats the net reduction of ED50 dosage of PTZ, which was able to induce clonic seizures in 50% of experimental animals caused by silver nanoparticles was established. This effect was more pronounced in postponed period of kindling and was followed by intensification of electrographic epileptiform manifestations. Silver argentum nanoparticles influence on chronic seizure activity was determined in conditions of chronic experiment. Authors concluded that argentum nanoparticles are responsible for seizure activity enhancening.На моделі пентиленететразол (ПТЗ)-індукованого кіндлінгу у щурів лінії Вістар показано зниження середньоефективної дози ПТЗ, що викликає клонічні судоми у 50 % щурів під впливом системного застосування наночастинок срібла. Даний ефект був більш вираженим у віддаленому періоді кіндлінгу й супроводжувався посиленням електрографічних епілептиформних проявів. За умов хронічного експерименту проводили досліди із визначення впливу наночастинок срібла на вираженість хронічної судомної активності. Автори висловлюють думку, що підсилення інтенсивності судомної активності відбувається завдяки придатності наночастинок срібла

Evaluation of bottom-up and top-down strategies for aggregated forecasts: state space models and arima applications

Abstract. In this research, we consider monthly series from the M4 competition to study the relative performance of top-down and bottom-up strategies by means of implementing forecast automation of state space and ARIMA models. For the bottomup strategy, the forecast for each series is developed individually and then these are combined to produce a cumulative forecast of the aggregated series. For the top-down strategy, the series or components values are first combined and then a single forecast is determined for the aggregated series. Based on our implementation, state space models showed a higher forecast performance when a top-down strategy is applied. ARIMA models had a higher forecast performance for the bottom-up strategy. For state space models the top-down strategy reduced the overall error significantly. ARIMA models showed to be more accurate when forecasts are first determined individually. As part of the development we also proposed an approach to improve the forecasting procedure of aggregation strategies

How Does Investors' Legal Protection Affect Productivity and Growth?

This paper analyzes the implications of investors' legal protection on aggregate productivity and growth. We have two main results. First, that better investors' legal protection can mitigate agency problems between investors and innovators and therefore expand the range of high-tech projects that can be financed by non-bank investors. Second, investors' legal protection shifts investment resources from less productive (medium-tech) to highly productive (high-tech) projects and therefore enhances economic growth. These results stem from two forces. On one hand, private investors' moral hazard problems (in which entrepreneurs shift investors' resources to their own benefit), and on the other hand innovators' risk of project termination by banks due to wrong signals about projects' probability of success. Our results are consistent with recent empirical studies that show a high correlation between legal investors' protection and the structure of the financial system as well as the economic performance at industry and macroeconomic levels