Clustering of Spontaneous Recurrent Seizures in a Mouse Model of Extended Hippocampal Kindling

Acute repetitive seizures or seizure clusters are common in epileptic patients. Seizure clusters are associated with a high risk of developing status epilepticus and increased morbidity and mortality. Seizure clusters are also recognizable in spontaneous recurrent seizures (SRS) that occur in animal models of epilepsy. The electrical kindling of a limbic structure is a commonly used model of temporal lobe epilepsy. Although classic kindling over the course of a few weeks does not generally induce SRS, extended kindling over the course of a few months can induce SRS in several animal species. SRS in kindled cats often occur in clusters, but the existence of seizure clusters in rodent models of extended kindling remains to be demonstrated. We explored the existence of seizure clusters in mice following extended hippocampal kindling. Adult male mice (C57BL/6) experienced twice daily hippocampal stimulations and underwent continuous 24-hour electroencephalogram (EEG)-video monitoring after ≥80 stimulations. SRS events were recognized by EEG discharges and associated motor seizures. Seizure clusters, defined as ≥4 seizures per cluster and intra-cluster inter-seizure intervals ≤ 120 min, were observed in 19 of the 20 kindled mice. Individual mice showed variable seizure clusters in terms of cluster incidence and circadian-like expression patterns. For clusters consisting of 4–7 seizures and intra-seizure intervals ≤ 20 min, no consistent changes in inter-seizure intervals, EEG discharge duration, or motor seizure severity scores were observed approaching cluster termination. These results suggested that seizure clustering represents a prominent feature of SRS in hippocampal kindled mice. We speculate that, despite experimental limitations and confounding factors, systemic homeostatic mechanisms that have yet to be explored may play an important role in governing the occurrence and termination of seizure clusters.

Dynamic Water-Level Regulation at Run-of-River Hydropower Plants to Increase Efficiency and Generation

In times of the energy transition and the intensified expansion of renewable energy systems, this article presents an optimization approach for run-of-river power, i.e., dynamic water-level regulation. Its basic idea is to use river sections influenced by backwater more evenly via the operating regime of a hydropower plant. In contrast to conventional dam and weir water level management, the head of the reservoir is not shifted toward the weir while the discharge rate increases but is kept in position by temporarily raising the water level. This generates a greater head for higher discharge rates of an operating regime. As can be shown using an example, this has a direct effect on the performance and, in interaction with the discharge duration curve, on the annual work of the plant. The dynamic water-level regulation, thus, represents an environmentally compatible, energy-efficient optimization for run-of-river hydropower plants.

Performance Analysis of VRLA Battery for DC Load at Telecommunication Base Station

The high level of power outage in Sukabumi-Cianjur area has influenced the operations of telecommunication industry in the vicinity. This has shortened the battery life at the Base Station (BTS). This study aims to analyze the performance of a (new) VRLA battery against a DC load (BTS) to support the continuity of BTS operation in case of a power outage. The research method used is a (new) battery charge-discharge procedure. Parameters are analyzed by determining the on-site battery discharge duration, the pressure at the battery terminals between cells during backup, and the capacity of the rectifier module to support fast charging. To support fast charging, the rectifier with the formula N+1 and C-rate is 10% and C15 is 15% of the battery capacity. The internal impedance value is 3.4 mΩ and the battery terminal pressure (torque) is 9-11 N/m. The battery performance analysis of the four BTS shows that two of them managed to do a backup, while the other two did not provide good performance.

Flood hazard on the Upper Angara river

The article provides the results of studies on flooding in the rivers of the northern Baikal on the example of the Upper Angara river basin. Some information about the situation with floods and mudflows in the dynamics since 1933 is highlighted. Spatial and temporal patterns of maximum levels, water discharge, duration of high levels, intensity of the water rise have been studied using standard methods of processing hydrological information to assess risks and hazard. On the basis of long-term observation series, expedition surveys we considered classification geohydrological characteristics of floods by genesis of their formation, recurrence of extreme levels, intensity and depth of floodplain inundation. The areas of possible flooding and waterlogging have been determined on the basis of large-scale maps using GIS technologies using ArcGIS. Settlements and infrastructure facilities located in hazardous areas have been identified. Engineering measures to mitigate flood risks in the Upper Angara river have been proposed.

Perampanel Reduces Hyperthermia-Induced Seizures in Dravet Syndrome Mouse Model

Treatment options for Dravet syndrome are limited. The aim of this study was to evaluate the antiepileptic effect of the AMPA receptor antagonist perampanel (PER) on a mouse model of Dravet syndrome (Scn1aE1099X/+). We report here that the PER (2 mg/kg) treatment inhibited the spontaneous recurrent seizures and attenuated epileptic activity in Scn1aE1099X/+ mice. In the hyperthermia-induced seizure experiment, PER clearly increased temperature tolerance and significantly ameliorated seizure frequency and discharge duration. PER also demonstrated antiepileptic effects in a cross-over study and a synergistic effect for attenuating heat-induced seizure when given in combination with stiripentol or valproic acid. The results showed that PER effectively decreased the occurrence of spontaneous recurrent seizures and showed significant therapeutic potential for hyperthermia-induced seizures with regard to both susceptibility and severity in a Dravet syndrome mouse model. Potential therapeutic effects of PER for treatment of Dravet syndrome were demonstrated.

INFLUENCE OF THE CAPACITANCE OF THE CAPACITOR OF THE DISCHARGE CIRCUIT OF SEMI-CONDUCTOR ELECTRIC DISCHARGE INSTALLATIONS ON THEIR OUTPUT CURRENTS OF LIMITED DURATION

Based on the analysis of transient processes of oscillatory and aperiodic discharges of the storage capacitor of the electric discharge installation to the load, it is proved that an increase in its capacity always causes an increase in the value of the discharge current corresponding to a fixed duration of the discharge, less than the duration of reaching the maximum value of the discharge current. For the capacities of the discharge capacitor varied over a wide range, the change in the value of the discharge current in the load during its forced interruption at a certain time was studied. Based on this study, we proposed a method for increasing the rate of rising of impulse currents in the load, which consists in choosing a discharge capacitor with a larger capacity compared with a capacity sufficient to implement the desired technological mode, and forced interrupting the current in the load at a certain point in time, which corresponds to a certain fixed duration discharge (less than the duration of reaching the maximum value of the discharge current when the capacitor capacity is sufficient to implement the required technological mode). The forced limitation of the discharge duration is carried out by a fully controlled semiconductor switch. This method can be used as the basis for the production of spark erosion nano-sized powders of metals and alloys. Ref. 15, fig. 3, table .

REGULATION OF OUTPUT DYNAMIC CHARACTERISTICS OF ELECTRIC DISCHARGE INSTALLATIONS WITH RESERVOIR CAPACITORS

The paper reveals the dependences of the output dynamic characteristics of semiconductor electric discharge installations (EDIs) with reservoir capacitors on the features of the change in the value of their capacitance. In particular, it is substantiated that for any fixed discharge duration less than the duration of reaching the maximum discharge current, an increase in the capacitance of such storage devices causes an increase in the value of the final discharge current both at aperiodic and oscillatory discharges in the linear resistance of the technological load. The change in the value of the discharge current in the load in the case of forced interruption of this current at a certain moment of time is investigated. Based on the obtained regularities, the authors of the work proposed to use the capacitance of the EDI's capacitor, which is larger than capacitance required to implement the maximum value of the discharge current in the load. Using a capacitor with a larger capacity and a fully controlled semiconductor switch in the discharge circuit of the EDI, it is possible to obtain the required maximum current value at a shorter duration of the discharge process. Thus, it is possible to regulate the main dynamic parameters of pulse currents in the load – the rate of their rise and/or their duration by changing the value of the capacitance of the discharge capacitor EDI. This approach is expedient for increasing the productivity of EDIs, focused on the production of dispersed spark powders of metals and alloys. References 15, figures 3.

Effect of Spark Discharge Duration and Timing on the Combustion Initiation in a Lean Burn SI Engine

Meeting the increasingly stringent emission and fuel efficiency standards is the primary objective of the automotive research. Lean/diluted combustion is a promising avenue to realize high-efficiency combustion and reduce emissions in SI engines. Under the diluted conditions, the flame propagation speed is reduced because of the reduced charge reactivity. Enhancing the in-cylinder charge motion and turbulence, and thereby increasing the flame speed, is a possible way to harness the combustion process in SI engines. However, the charge motion can have a significant effect on the spark ignition process because of the reduced discharge duration and frequent restrikes. A longer discharge duration can aid in the formation of the self-sustained flame kernel and subsequent stable ignition. Therefore, an empirical study is undertaken to investigate the effect of the discharge duration and ignition timing on the ignition and early combustion in a port fueled SI engine, operated under lean conditions. The discharge duration is modulated from 1 ms to 8 ms through a continuous discharge strategy. The discharge current and voltage measurements are recorded during the engine operation to characterize the discharge process. The in-cylinder charge is diluted using fresh air to achieve lean combustion. The in-cylinder pressure measurement and heat release analysis are used to investigate the ignition and combustion characteristics of the engine. Preliminary results indicate that while the discharge duration has a marginal effect on the ignition delay, cyclic variations are notably impacted.