52 research outputs found

    The differences between Cis-and Trans-Gene inactivation caused by heterochromatin in Drosophila

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    Position-effect variegation (PEV) is the epigenetic disruption of gene expression near the de novo-formed euchromatin-heterochromatin border. Heterochromatic cis-inactivation may be accompanied by the trans-inactivation of genes on a normal homologous chromosome in trans-heterozygous combination with a PEV-inducing rearrangement. We characterize a new genetic system, inversion In(2)A4, demonstrating cis-acting PEV as well as trans-inactivation of the reporter transgenes on the homologous nonrearranged chromosome. The cis-effect of heterochromatin in the inversion results not only in repression but also in activation of genes, and it varies at different developmental stages. While cis-actions affect only a few juxtaposed genes, trans-inactivation is observed in a 500-kb region and demonstrates а nonuniform pattern of repression with intermingled regions where no transgene repression occurs. There is no repression around the histone gene cluster and in some other euchromatic sites. trans-Inactivation is accompanied by dragging of euchromatic regions into the heterochromatic compartment, but the histone gene cluster, located in the middle of the trans-inactivated region, was shown to be evicted from the heterochromatin. We demonstrate that trans-inactivation is followed by de novo HP1a accumulation in the affected transgene; trans-inactivation is specifically favored by the chromatin remodeler SAYP and prevented by Argonaute AGO2

    Effects of antioxidant bienzyme conjugate in rats with endotoxin shock model after different regime of administration

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    Cardiovascular injuries have been going along with oxidative stress as usually. The antioxidant enzymes (as superoxide dismutase /SOD/ and catalase /CAT/) are significant potential agents for therapeutic aim but they demanded the improvement of their biopharmaceutical properties. For this goal the bienzyme covalent conjugate was obtained by binding SOD with CAT via endothelial glycocalyx glycosaminoglycan – chondroitin sulfate (SOD-CHS-CAT). The SOD-CHS-CAT conjugate had prophylaxis and preventive actions after intravenous administration of hydrogen peroxide in rabbits and rats. It should be noted the oxidative stress accompanies for development of endotoxin shock. There is the model of septic shock of animals due to administration of bacterial lypopolysaccharide (LPS, from Salmonella enterica serotype Typhimurium) them as provoking infectious agent. The therapeutic effect of bienzyme SOD-CHS-CAT conjugate has special research interest associated with activity of conjugate after preventive and medicative administration (i.e. before and after LPS administration, respectively). The effect of bienzyme conjugate administered in medicative regime had increased the survival of rats for endotoxin shock. It was the expressive efficacy of medicinal employment of SOD-CHS-CAT conjugate. The obtained results have been grounded the need of experimental evaluation in respect to efficacy of per oral prophylaxis administration of SOD-CHS-CAT conjugate on the endotoxin model injury in rats induced by LPS bolus. The intravenous bolus administration of LPS in rats has been induced the endotoxin shock development with arterial pressure (AP) decrease, heart rate (HR) increase, impairment of condition even before the lethal termination. The AP decrease was restored faster in experimental group; the alterations of HR were similar in both groups. The survival index (73 % in experimental and 63 % in control groups) for twenty-four hours was similar. Higher survival index (95 % in experimental and 75 % in control groups, for five hours) was marked in experimental group emphasizing the action celerity of SOD-CHS-CAT conjugate in vivo. The SOD-CHS-CAT conjugate was active during cytokine phase of endotoxin injury and distant damage stages. Moreover, the level of NO in lever, lung, kidney, heart was enhanced during endotoxin shock progress and there were not significant alterations of NO level after bienzyme conjugate administration intravenously. The changes of urea and creatinine in blood samples have been evidenced the protective action of bienzyme conjugate in respect to kidney function. Diversity of other index alterations have been hampered the forming agreed conclusions about state of other organs. Taken together these date indicated (on the base of survival increase of rats with SOD-CHS-CAT conjugate for endotoxin shock) the other protective effects of this conjugate (besides NO preservation) and importance of its action mechanism investigation on animal model with continuous development of injury and involvement of other vasoactive agents (NO-independent progress of therapeutic effect). This research was supported in part by RFBR grant 15-04-03584 and Ministry of Health Care of Russian Federation

    Increasing Human Performance by Sharing Cognitive Load Using Brain-to-Brain Interface

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    Brain-computer interfaces (BCIs) attract a lot of attention because of their ability to improve the brain's efficiency in performing complex tasks using a computer. Furthermore, BCIs can increase human's performance not only due to human-machine interactions, but also thanks to an optimal distribution of cognitive load among all members of a group working on a common task, i.e., due to human-human interaction. The latter is of particular importance when sustained attention and alertness are required. In every day practice, this is a common occurrence, for example, among office workers, pilots of a military or a civil aircraft, power plant operators, etc. Their routinely work includes continuous monitoring of instrument readings and implies a heavy cognitive load due to processing large amounts of visual information. In this paper, we propose a brain-to-brain interface (BBI) which estimates brain states of every participant and distributes a cognitive load among all members of the group accomplishing together a common task. The BBI allows sharing the whole workload between all participants depending on their current cognitive performance estimated from their electrical brain activity. We show that the team efficiency can be increased due to redistribution of the work between participants so that the most difficult workload falls on the operator who exhibits maximum performance. Finally, we demonstrate that the human-to-human interaction is more efficient in the presence of a certain delay determined by brain rhythms. The obtained results are promising for the development of a new generation of communication systems based on neurophysiological brain activity of interacting people. Such BBIs will distribute a common task between all group members according to their individual physical conditions

    From Novel Technology to Novel Applications: Comment on “An Integrated Brain-Machine Interface Platform With Thousands of Channels” by Elon Musk and Neuralink

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    The first attempts to translate neuronal activity into commands to control external devices were made in monkeys yet in 1960s [1]. After that, during 1960-1970, the biological feedback was realized in monkeys, to provide voluntary control of the firing rate of cortical neurons [2,3]. The term “brain-computer interface” appeared only in earlier 1970s [4]. The brain-computer interface is usually referred to as a “brain-machine interface” in invasive studies. Nowadays, the brain-computer interface and brain-machine interface research and applications are considered one of the most exciting interdisciplinary areas of science and technology

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    Neuronal pathway and signal modulation for motor communication

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    The knowledge of the mechanisms of motor imagery (MI) is very important for the development of braincomputer interfaces. Depending on neurophysiological cortical activity, MI can be divided into two categories: visual imagery (VI) and kinesthetic imagery (KI). Our magnetoencephalography (MEG) experiments with ten untrained subjects provided evidences that inhibitory control plays a dominant role in KI. We found that communication between inferior parietal cortex and frontal cortex is realised in the mu-frequency range. We also pinpointed three gamma frequencies to be used for motor command communication. The use of artificial intelligence allowed us to classify MI of left and right hands with maximal classification accuracy using the brain activity encoded in the identified gamma frequencies which were then proposed to be used for communication of specifics. Mu-activity was identified as the carrier of gamma-activity between these areas by means of phase-amplitude coupling similar to the modern day radio wave transmission
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