92 research outputs found
Unknown Epistle to Tsar’ Fedor Ivanovich from Constantinople
No full textThe paper is about a little known epistle which is kept in the unique handwritten miscellanea of
the first part of 17th century. This epistle is addressed by unknown monk from Constantinople to orthodox
tsar’. It contains wordy praises on tsar’ and his favors to different countries. The author asks to send a sermon
about faith and two printed books into Rech’ Pospolitaya. The epistle should be brought to Moscow by
Danila Ivanovich Isleniev, a Russian ambassador in Constantinople. So the epistle was a covering letter for
unknown sermon.
Data comparison and studying of archive documents let us to suppose that the epistle was addressed to
Moscow tsar’ Fedor Ivanovich and was written in 1595–1596 before the Brest’s Union (1596). The author
of the epistle was an orthodox monk, native of Rech’ Pospolitaya who was going to live in one of the Athos’
hermitages later. Probably the epistle was written by Isaakiy Boriskovich, a follower of Meletios Pigas, the
Patriarch of Alexandria. Isaakiy Boriskovich departed from Constantinople before Brest’s Union. He visited
Athos but later his life was completely connected with struggle of Orthodox believers against the Union in
the Kyiv Metropolia. It is unknown what was the sermon about faith he asked to send to orthodox believers
in Kyiv Metropolia. We can suppose that it was one of numerous sermons and epistles of orthodox Greek
hierarchs (probably of Meletios Pigas).
The epistle addressed to tsar’ Fedor Ivanovich is published in addition to the research.The research was supported by the Russian Foundation for Basic Research, project № 18-512-18006 Болг_а
«Migration of the texts in cultural area of the Slavia Orthodoxa»
Nikolai Evreinov and Edith Craig as Mediums of Modernist Sensibility
No full textNikolai Evreinov (1870-1953) was a Russian playwright, director, and theorist of the theatre who played a leading part in the modernist movement of Russian theatre. Evreinov's 1911 monodrama The Theatre of the Soul (V kulisakh dushi) was staged by the Crooked Mirror theatre in St Petersburg in 1912. It was also performed in London (1915) and Rome (1929), and inspired Man Ray to create his aerograph The Theatre of the Soul (1917). In this article Alexandra Smith links Evreinov's play to Russian modernist thought shaped by the atmosphere of crisis associated with the Russo-Japanese War and the first Russian Revolution. It demonstrates that Edith Craig's production of Evreinov's play suggests that the philosophy of theatricalization of everyday life might enable modern subjects to overcome the fragmentation of modern society. Craig's use of the montage-like techniques of Evreinov's play prefigures cinematographic experiments of the 1920s and Marinetti's notion of synthetic theatre. Alexandra Smith is a Reader in Russian Studies at the University of Edinburgh and is the author of The Song of the Mockingbird: Pushkin in the Works of Marina Tsvetaeva (1994) and Montaging Pushkin: Pushkin and Visions of Modernity in Russian Twentieth-Century Poetry (2006), as well as numerous articles on Russian literature and culture.</p
GAF-CaMP3–sfGFP, An Enhanced Version of the Near-Infrared Genetically Encoded Positive Phytochrome-Based Calcium Indicator for the Visualization of Neuronal Activity
No full textThe first generation of near-infrared, genetically encoded calcium indicators (NIR-GECIs) was developed from bacterial phytochrome-based fluorescent proteins that utilize biliverdin (BV) as the chromophore moiety. However, NIR-GECIs have some main drawbacks such as either an inverted response to calcium ions (in the case of NIR-GECO1) or a limited dynamic range and a lack of data about their application in neurons (in the case of GAF-CaMP2–superfolder green fluorescent protein (sfGFP)). Here, we developed an enhanced version of the GAF-CaMP2–sfGFP indicator, named GAF-CaMP3–sfGFP. The GAF-CaMP3–sfGFP demonstrated spectral characteristics, molecular brightness, and a calcium affinity similar to the respective characteristics for its progenitor, but a 2.9-fold larger DF/F response to calcium ions. As compared to GAF-CaMP2–sfGFP, in cultured HeLa cells, GAF-CaMP3–sfGFP had similar brightness but a 1.9-fold larger DF/F response to the elevation of calcium ions levels. Finally, we successfully utilized the GAF-CaMP3–sfGFP for the monitoring of the spontaneous and stimulated activity of neuronal cultures and compared its performance with the R-GECO1 indicator using two-color confocal imaging. In the cultured neurons, GAF-CaMP3–sfGFP showed a linear DF/F response in the range of 0–20 APs and in this range demonstrated a 1.4-fold larger DF/F response but a 1.3- and 2.4-fold slower rise and decay kinetics, respectively, as compared to the same parameters for the R-GECO1 indicator
A sensitive soma-localized red fluorescent calcium indicator for in vivo imaging of neuronal populations at single-cell resolution.
No full textRecent advancements in genetically encoded calcium indicators, particularly those based on green fluorescent proteins, have optimized their performance for monitoring neuronal activities in a variety of model organisms. However, progress in developing red-shifted GECIs, despite their advantages over green indicators, has been slower, resulting in fewer options for end users. In this study, we explored topological inversion and soma-targeting strategies, which are complementary to conventional mutagenesis, to re-engineer a red genetically encoded calcium indicator, FRCaMP, for enhanced in vivo performance. The resulting sensors, FRCaMPi and soma-targeted FRCaMPi (SomaFRCaMPi), exhibit up to 2-fold higher dynamic range and peak ΔF/F0 per single AP compared to widely used jRGECO1a in neurons both in culture and in vivo. Compared to jRGECO1a and FRCaMPi, SomaFRCaMPi reduces erroneous correlation of neuronal activity in the brains of mice and zebrafish by two- to 4-fold due to diminished neuropil contamination without compromising the signal-to-noise ratio. Under wide-field imaging in primary somatosensory and visual cortices in mice with high labeling density (80-90%), SomaFRCaMPi exhibits up to 40% higher SNR and decreased artifactual correlation across neurons. Altogether, SomaFRCaMPi improves the accuracy and scale of neuronal activity imaging at single-neuron resolution in densely labeled brain tissues due to a 2-3-fold enhanced automated neuronal segmentation, 50% higher fraction of responsive cells, up to 2-fold higher SNR compared to jRGECO1a. Our findings highlight the potential of SomaFRCaMPi, comparable to the most sensitive soma-targeted GCaMP, for precise spatial recording of neuronal populations using popular imaging modalities in model organisms such as zebrafish and mice
NeMeHg, genetically encoded indicator for mercury ions based on mNeonGreen green fluorescent protein and merP protein from Shigella flexneri
No full textThe detection of mercury ions is an important task in both environmental monitoring and cell biology research. However, existing genetically encoded sensors for mercury ions have certain limitations, such as negative fluorescence response, narrow dynamic range, or the need for cofactor supplementation. To address these limitations, we have developed novel sensors by fusing a circularly permutated version of the mNeonGreen green fluorescent protein with the merP mercury-binding protein from Gram-negative bacteria Shigella flexneri. The developed NeMeHg and iNeMeHg sensors responded to mercury ions with positive and negative fluorescence changes, respectively. We characterized their properties in vitro. Using the developed biosensors, we were able to successfully visualize changes in mercury ion concentration in mammalian cultured cells
Advances in Engineering and Application of Optogenetic Indicators for Neuroscience
No full textOur ability to investigate the brain is limited by available technologies that can record biological processes in vivo with suitable spatiotemporal resolution. Advances in optogenetics now enable optical recording and perturbation of central physiological processes within the intact brains of model organisms. By monitoring key signaling molecules noninvasively, we can better appreciate how information is processed and integrated within intact circuits. In this review, we describe recent efforts engineering genetically-encoded fluorescence indicators to monitor neuronal activity. We summarize recent advances of sensors for calcium, potassium, voltage, and select neurotransmitters, focusing on their molecular design, properties, and current limitations. We also highlight impressive applications of these sensors in neuroscience research. We adopt the view that advances in sensor engineering will yield enduring insights on systems neuroscience. Neuroscientists are eager to adopt suitable tools for imaging neural activity in vivo, making this a golden age for engineering optogenetic indicators. Keywords: optogenetic tools; neuroscience; calcium sensor; voltage sensor; neurotransmitter
Nasledie «Sidora Karpovicha» v sovremennoj pesennoj kul'ture
No full textThe article analyzes the transformation of the Russian folk song “Dear
Sir Sidor Karpovich”, studied by V. N. Toporov in 1979. This text was a
prison game depicting a funeral rite and having a function of initiation,
but re cently it has become a popular song and lost its minor mood. At the
same time, the protagonist (Sidor Karpovich) loses his name and becomes
a secondary character. The main role is taken by his wife, Lyubka, called
by the epithet “gray dove”. The plot of the song is based on twists and turns of her life after the death of her husband. Analyzing the image of the dove in poetry and, in particular, in prison lyrics, as well as looking at possible influences of other popular songs, the author proposes possible reasons for such a transformation
Near-Infrared Genetically Encoded Positive Calcium Indicator Based on GAF-FP Bacterial Phytochrome
No full textA variety of genetically encoded calcium indicators are currently available for visualization of calcium dynamics in cultured cells and in vivo. Only one of them, called NIR-GECO1, exhibits fluorescence in the near-infrared region of the spectrum. NIR-GECO1 is engineered based on the near-infrared fluorescent protein mIFP derived from bacterial phytochromes. However, NIR-GECO1 has an inverted response to calcium ions and its excitation spectrum is not optimal for the commonly used 640 nm lasers. Using small near-infrared bacterial phytochrome GAF-FP and calmodulin/M13-peptide pair, we developed a near-infrared calcium indicator called GAF-CaMP2. In vitro, GAF-CaMP2 showed a positive response of 78% and high affinity (Kd of 466 nM) to the calcium ions. It had excitation and emission maxima at 642 and 674 nm, respectively. GAF-CaMP2 had a 2.0-fold lower brightness, 5.5-fold faster maturation and lower pH stability compared to GAF-FP in vitro. GAF-CaMP2 showed 2.9-fold higher photostability than smURFP protein. The GAF-CaMP2 fusion with sfGFP demonstrated a ratiometric response with a dynamic range of 169% when expressed in the cytosol of mammalian cells in culture. Finally, we successfully applied the ratiometric version of GAF-CaMP2 for the simultaneous visualization of calcium transients in three organelles of mammalian cells using four-color fluorescence microscopy
Advances in Engineering and Application of Optogenetic Indicators for Neuroscience
No full textOur ability to investigate the brain is limited by available technologies that can record biological processes in vivo with suitable spatiotemporal resolution. Advances in optogenetics now enable optical recording and perturbation of central physiological processes within the intact brains of model organisms. By monitoring key signaling molecules noninvasively, we can better appreciate how information is processed and integrated within intact circuits. In this review, we describe recent efforts engineering genetically-encoded fluorescence indicators to monitor neuronal activity. We summarize recent advances of sensors for calcium, potassium, voltage, and select neurotransmitters, focusing on their molecular design, properties, and current limitations. We also highlight impressive applications of these sensors in neuroscience research. We adopt the view that advances in sensor engineering will yield enduring insights on systems neuroscience. Neuroscientists are eager to adopt suitable tools for imaging neural activity in vivo, making this a golden age for engineering optogenetic indicators
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