Modulation of alpha power at encoding and retrieval tracks the precision of visual short-term memory.

Our ability to hold information in mind is strictly limited. We sought to understand the relationship between oscillatory brain activity and the allocation of resources within visual short-term memory (VSTM). Participants attempted to remember target arrows embedded among distracters and used a continuous method of responding to report their memory for a cued target item. Trial-to-trial variability in the absolute circular accuracy with which participants could report the target was predicted by event-related alpha synchronization during initial processing of the memoranda and by alpha desynchronization during the retrieval of those items from VSTM. Using a model-based approach, we were also able to explore further which parameters of VSTM-guided behavior were most influenced by alpha band changes. Alpha synchronization during item processing enhanced the precision with which an item could be retained without affecting the likelihood of an item being represented per se (as indexed by the guessing rate). Importantly, our data outline a neural mechanism that mirrors the precision with which items are retained; the greater the alpha power enhancement during encoding, the greater the precision with which that item can be retained.

[Conditions that influence bacterial luminescence in the presence of blood serum].

Conditions that influence the luminescence of natural and recombinant luminescent bacteria in the presence of blood serum were studied. In general, blood serum quenched the luminescence of the marine Photobacterium phosphoreum and the recombinant Escherichia coli strains harboring the luminescent system genes of Photobacterium leiognathi, but enhanced the luminescence of the soil bacterium Photorhabdus luminescens Zm1 and the recombinant E. coli strain harboring the lux operon of P. luminescens Zm1. The quenching effect of blood serum increased with its concentration and the time and temperature of incubation. The components of blood serum that determine the degree and specificity of its action on bacterial luminescence were identified.

[Determination of the bactericidal activity of blood serum by recombinant luminescence strains of Escherichia coli].

It has been experimentally proven as possible to use recombinant strains of Escherichia coli carrying the genes of luminescence of natural fluorescent bacteria in evaluating the bactericidal activity of blood serum (BABS). The shaping fluorescence inhibition was shown to be in proportion to the developing bactericidal effect in respect to the luminescent strains of Escherichia coli, which depended on a used concentration of blood serum and time of contact. The list of E. coli recombinant strains, which fit in most of all with the evaluation of BABS, was drawn. The values of the bactericidal activity of blood serum determined by the routine bacteriological and nephelometric methods were demonstrated to coincide with those determined by the worked-out bio-luminescent method.

[Space-time water monitoring system at the Iriklinsk hydroelectric power station]. / Sistema prostranstvenno-vremennogo monitoringa biotoksichnosti vody na Iriklinskoi GRES.

The Microbiosensor B 17677 F test system was applied to make a space-time monitoring of the biotoxicity of water used for production and everyday purposes at the Iriklinsk hydroelectric power station (IHEPS) and to identify the leading causes determining the biotoxicity of tested samples. There were seasonal variations in the biotoxicity with the maximum in spring and with minimum in winter and spring and a relationship of the spring rise in the biotoxicity to water pH changes. There was also an association of the certain values of the biotoxicity of industrial water with the concentration of petroleum products that are major pollutants at the IHEPS. The datum points that characterize the maximum level of technogenic exposure were identified.

Vigilance states and body temperature during the circadian cycle in fed and fasted pigeons (Columba livia).

Fasting induces nocturnal hypothermia in pigeons. Slow-wave sleep (SWS) and paradoxical sleep (PS) are associated with reduced heat production in pigeons. The possibility that fasting-induced nocturnal hypothermia is related to increased SWS and PS was examined by comparing body temperature (Tb) and vigilance states when pigeons were fed and fasted. The results showed that when Tb is decreasing near the beginning of the dark phase, the percentage of total recording time (%TRT) spent in SWS and PS was elevated in fasting due to increased frequency of episodes and increased duration of PS episodes. When Tb was low during the middle segment of the dark phase, SWS was elevated in fasting due to increased episode duration. However, fasting did not alter PS, which increased in %TRT across the segment due to increased episode frequency. When Tb was rising during the final hours of dark, SWS remained elevated in fasting and %TRT in SWS and PS was relatively high. SWS and PS may promote the fasting pigeon's entry into, and maintenance of, nocturnal hypothermia.