Nucleotide Dynamics During Flossing of Polycation-DNA-Polycation through a Nanopore using Molecular Dynamics

The full potential of solid state nanopores is yet to be realized for genome sequencing. Due to its robustness it can handle strong voltage amplitude and frequency. The effect of strong alternating voltage on the dynamics of nucleotides during translocation has been explored. We proposed a setup consisting of single stranded DNA covalently linked with symmetric polycations at both ends fashioned after the proposal of Kasianowicz. Such a setup allows for repeated back and forth motion of the DNA along the nanopore (1.45 nm diameter and 1.53 nm thick) by simply switching the voltage polarity if the polycation tail is sufficiently long (greater than or equal to 10) and the applied voltage is below 0.72 volts, but the average residence time of the nucleotides are too small to be of any practical use (6-30 ns). When alternating voltage of higher frequency is applied, it enhances the average residence time of the nucleotides by an order of magnitude to approximately 0.1 microseconds relative to direct voltage but the individual trajectories are too stochastic. Since, we are able to collect repeated read on the dynamics of individual nucleotides, we obtained the most probable time of appearance of a nucleotide within the nanopore. With such construct we were able to get almost linear dependence of most probable time versus nucleotide index, after gaussian fitting.

NGC 4993, the shell galaxy host of GW170817: constraints on the recent galactic merger

Context. NGC 4993 is the shell galaxy host of the GRB170817A short gamma-ray burst and the GW170817 gravitational-wave event produced during a binary-neutron-star coalescence. Aims. The galaxy shows signs, including the stellar shells, that it has recently accreted a smaller, late-type galaxy. The accreted galaxy might be the original host of the binary neutron star. Methods. We measured the positions of the stellar shells of NGC 4993 in an HST/ACS archival image and use the shell positions to constrain the time of the galactic merger. Results. According to the analytical model of the evolution of the shell structure in the expected gravitational potential of NGC 4993, the galactic merger happened at least 200 Myr ago, with a probable time roughly around 400 Myr, and the estimates higher than 600 Myr being improbable. This constitutes the lower limit on the age of the binary neutron star, because the host galaxy was probably quenched even before the galactic merger, and the merger has likely shut down the star formation in the accreted galaxy. We roughly estimate the probability that the binary neutron star originates in the accreted galaxy to be around 30%.

Afrighid drachm from the nearest environments of the Novgorod townsite (a new view 40 years afterwards)

The present authors reconsider the already published in 1981 Afrighid drachm of the last quarter of the 8th century AD found during the deepening of the riverbed near the Novgorod townsite. A new investigation has resulted in a more exact attribution of the coin. The examination of the metal of the find, its state of preservation and the circulation of the eastern monetary silver in the Ilmen-Volkhov region have allowed us to conclude on the most probable time of its occurrence in the territory under consideration.

The Shakespearean Inside

The Shakespearean Inside is a study of all soliloquies and solo asides in Shakespeare’s complete plays. The first step in the research process was the creation of the Shakespearean Inside Database (SID), where these speeches were annotated according to variables of genuine literary interest such as act, dramatic subgenre, probable time of composition, dramatic speech acts, selected figures of speech and character attributes such as gender or class. Such comprehensive and detailed data makes it possible to generalise dependably about Shakespeare’s authorial habits, and by extension, to identify situations where the author departs in interesting ways from his authorial habits. The Shakespearean Inside uses these broad patterns and significant exceptions as a backdrop for fresh interpretations of various Shakespeare plays, from early works such as The Taming of the Shrew and Two Gentlemen of Verona to mature tragedies like Hamlet and late plays such as The Tempest and The Two Noble Kinsmen.

Assessment of a new "DS-EIA-HIV-AB-TERM" assay to determine the probable time of infection with human immunodeficiency virus-1 (HIV-1)

The epidemiological situation for HIV infection in Russia remains to be extremely stringent, which requires a search for new, more efficient and cost-effective solutions aimed at countering the epidemic. The inclusion of laboratory studies with the use of a test system for the determination of the remoteness of HIV infection in routine surveillance practices will permit to determine the frequency of occurrence of early cases of infections among newly diagnosed HIV-positive persons. The analysis of this criterion at the population level will help to objectively evaluate the effectiveness of prevention, control activities carried out in a particular area. The increase of objectivity in the determination of the time elapsed from the moment of infection of HIV-1 with the use of the test system DSEIA-HIV-Ab-TERM provides the opportunity to use the obtained results in the epidemiological investigation for the purpose of more accurate and complete identification of contact persons. The determination of the probable period of infection may also be required in the solving the question on the prescription of antiretroviral therapy as a complementary study in the monitoring of HIV drug resistance. The aim of this work was to determine the effectiveness of the new test system DS-EIAHIV-Ab-TERM for the determination of the likely timing of HIV-1 infection. There were studied serum samples (plasma) of blood of HIV-infected persons with epidemiologically established time of infection (n = 281) and samples of commercial seroconversion panels. Results of the performed study showed that the probability of a correct detection of the remoteness of HIV-1 infection for samples from individuals with the most probable time of the established fact of infection was 95%, for samples of commercial seroconversion panels - 100%. The data demonstrated the high efficacy of the test system DS-“EIAHIV-Ab-TERM” in the determination of the most probable timing of infection with human immunodeficiency virus type 1, that in combination with the speed and simplicity of the procedure allows to recommend it for use in the laboratory practice.

Ephrem the Syrian’s hymn On the Crucifixion 4

This article offers a translation of the hymn De Crucifixione 4 by Ephrem, the Syrian theologian, which forms part of his cycle of hymns for the celebration of Easter. The symbolic interpretation of particularly the tearing of the temple veil in this hymn – together with the cosmic signs which occurred at the death of Jesus – is investigated. An attempt is made to correlate Ephrem’s fierce anti-Jewish polemics with the intentions of the authors of the Synoptic Gospels and with Ephrem’s circumstances at the probable time of composition of the hymn.

The Self-Portrait by Alexander Brullov

Is devoted to watercolour self­portrait of the Russian architect and graphic artist. The author attributes this work basing on archival documents and suggests the probable time and place of its creation.