GNAO1 encephalopathy is an orphan genetic disease associated with early infantile epilepsy, impaired motor control, and severe developmental delay. The disorder is caused by mutations in the GNAO1 gene, leading to dysfunction of the encoded protein Gao1. There is no cure for this disease, and symptomatic therapy is ineffective. Phenotypic heterogeneity highlights the need for a personalized approach for treating patients with a specific clinical variant of GNAO1 and requires the study of the disease mechanism in animal and cell models. Towards this aim, we developed an approach for modeling GNAO1 encephalopathy and testing gene therapy drugs in primary neurons derived from healthy mice. We optimized the delivery of transgenes to Gαo1-expressing neurons using recombinant adeno-associated viruses (rAAV). We assessed the tropism of five neurotropic AAV serotypes (1, 2, 6, 9, DJ) for Gαo1-positive neurons from the whole mouse brain. The DJ serotype showed the highest potential as a reporter delivery vehicle, infecting up to 66% of Gαo1-expressing cells without overt cytotoxicity. We demonstrated that AAV-DJ also provides efficient delivery and expression of genetic constructs encoding normal and mutant Gαo1, as well as short hairpin RNA (shRNA) to suppress endogenous Gnao1 in murine neurons. Our results will further simplify the study of the pathological mechanism for clinical variants of GNAO1, as well as optimize the testing of gene therapy approaches for GNAO1 encephalopathy in cell models.
The work is devoted to the study of the characteristics of the PING-M hard x-ray polarimeter using its physical model (PING-P FM). The PING-M instrument is developed jointly by the Moscow Engineering Physical Iinstitute and the Ioffe Institute for the mission “Interhelioprobe”. The operation of the device is based on Compton scattering. The degree and direction of linear polarization are determined by measuring the asymmetry of the scattered radiation field. The device uses active scatterers that register the Compton recoil electron. A useful event is the case when two impulses in the detector-scatterer and in the detector-receiver of scattered radiation coincide. The physical model represents the detector part of the polarimeter. It contains three scatterers and six receivers of scattered radiation – a total of 18 pairs of detectors oriented at different azimuthal angles. As a result of the experiments, the dependences of counting rates in pairs of detectors on the positional angle of the polarization plane of the incident radiation were measured. The modulation depth of this dependence determines the sensitivity of the device to the polarization degree. The sensitivity of the device is estimated.
The paper presents the results of processing of data on the soft X-ray solar radiation obtained by the PINGVIN-M instrument aboard the KORONAS-FOTON spacecraft in July 2009. The high sensitivity of the device, combined with effective compensation for the magnetospheric background over most of the orbit, made it possible to study in detail the evolution of X-ray radiation from the active region and its X-ray bursts-from microflares to class-C bursts. The analyzed data refer to the period of deep minimum solar activity, during which there was only one active region emitting in the soft X-ray range on the solar disk. This made it possible to study the characteristics of soft X-ray radiation in this region without additional background with a device that records radiation from the entire solar disk, which significantly increases the reliability of the estimates of the parameters of the time and energy spectra of X-ray radiation derived from experimental data.
The paper describes the physical model of the PING-P polarimetry unit of the PING-M X-ray polarimeter. The polarimeter is developed jointly by the Ioffe Institute and the Institute of Astrophysics of the Moscow Engineering Physics Institute for the Interhelioprobe mission. The model (PING-P-FM), made by the Ioffe Institute, represents the detector part of the polarimeter. The polarization degree is determined by the measurement of the asymmetry of the scattered radiation field. The device uses active scatterers based on paraterphenyl crystals for detecting the events of Compton scattering. A useful signal is the coincidence of pulses from one of the active scatterers (detector-scatterer) and one detector-receiver of scattered radiation. The polarimetry unit contains 3 detector-scatterers and 6 detector-receivers, thus resulting in 18 measurement channels. The requirements for instrument symmetry and stability of the measuring channels are high. The paper presents the results of an experimental study of the parameters of the measuring channels of the PING-P-FM model and their calibrations at different X-ray energies using Cd-109, Am-241, and Ba-133 isotope sources.
The time history of the temperature and the emission measure of the solar flare plasma have been studied relying upon the experimental data on the soft X-rays recorded by the IRIS spectrometer on June 29, 2002 (F1) and March 27, 2003 (F2). F1 was a thermal flare and was not accompanied by hard X-rays. This data analysis revealed that at least two sequential energy-release processes occurred during the F1 event. The F2 event took place behind the limb, so only the top part of the flare loop being the soft X-ray source was recorded by the satellite-based spectrometer. From this data analysis it appeared that fast plasma heating occurred in the initial stage of F2 and then the flare region expanded and the emission measure of flare plasma increased.
Architecture and operational concept description of the PING-P unit are presented. In-flight calibration and stabilization procedures are listed. Data and technology characteristics are presented. Two key functional modes, the “Patrol” and the “Burst”, are described. Spectral data: single detector spectra, double coincidence spectra, calibration spectra, automatic calibration LED amplitude spectra. A burst detection system which is aimed to detect bursts in a pseudo-stationary flux. In-flight control procedure is described. Raw data acquisition, processing and storing techniques implemented in the PING-P unit are considered. Also a prompt data processing procedure and data transmission protocols are reviewed.
We reconstruct the energy distribution of electrons accelerated in the April 15, 2002 solar flare on the basis of the data from the IRIS X-ray spectrometer onboard the CORONAS-F satellite. We obtain the solution to the integral equations describing the transformation of the spectrum of X-ray photons during the recording and reconstruction of the spectrum of accelerated electrons in the bremsstrahlung source using the random search method and the Tikhonov regularization method. In this event, we detected a singularity in the electron spectrum associated with the existence of a local minimum in the energy range 40–60 keV, which cannot be detected by a direct method.
The PING-M experiment is designed to investigate solar X-ray activity. The instrument includes a hard X-ray polarimeter (PING-P), a hard X-ray spectrometer (HXRS) and a soft X-ray spectrometer (SXRS). PING-P has the energy range of 20-150 keV and an effective area of about 2.5 cm(2). It uses three organic scintillation detectors as active scatterers, which work in coincidence with six absorber detectors, based on CSI(T1) scintillator. This technique allows us to considerably improve the polarimeter sensitivity. HXRS has the energy range of 20-600 keV and an effective area of about 15 cm2. It is based on a fast inorganic scintillator (LaBr3(Ce) or CeBr3) with a relatively high energy resolution of 3.5-4.5% at 662 keV. The SXRS energy range is 1.5-25 keV, and its aperture is empty set0.1 mm, which provides the registration of solar flares in the range from C1 to X20 class of GOES scale. It is based on a SDD semiconductor detector with an energy resolution better than 200 eV at 5.9 keV line. The experiment will be performed onboard the Russian interplanetary mission Interhelioprobe which is planned for launch after 2025. The instrument will allow us to investigate angular and energy distributions of accelerated electrons, plasma heating processes, etc. Stereoscopic polarimetry and spectrometric observations will be possible if a similar instrument is installed onboard a near Earth satellite, or the second probe of the Interhelioprobe mission. (C) 2016 COSPAR. Published by Elsevier Ltd. All rights reserved.
The Interhelioprobe mission aims to investigate the inner heliosphere and the Sun from close distances (up to 0.3 AU) and from out of the ecliptic plane (up to 30°). In this paper we present the relevance of the mission and its main scientific objectives, describe the scientific payload, ballistic scenario and orbits of the spacecraft. Possibilities of scientific cooperation with other solar and heliospheric space missions are also mentioned.
The research program underlying the IRIS experiment (Russian acronym for Investigation of Solar X-Ray Emission) encompasses investigation of the characteristics of X-ray emission from solar flares and of their precursors in the 2–200-keV range, which would form a basis for development of physical models describing the process of buildup and explosive release of energy in a solar flare, as well as accumulation of experimental data to serve in devising techniques for forecasting the solar flare activity
A technique for reconstructing energy spectra of electrons accelerated in solar flares is suggested that is based on the rigorous solution of the inverse problem considering their X-ray bremsstrahlung. Model calculations are made for various spectra, and it is proved that this technique makes it possible to find the electron energy distribution in real flare events. The energy distribution of high-energy electrons accelerated in the solar flare observed on July 26, 2002, is reconstructed. It is shown that the hard X-ray spectrum of the flare may result from the bremsstrahlung of three groups of high-energy electrons.
Приведены основные характеристики прибора ПИНГВИН-М, запущенного на орбиту в составе космического аппарата КОРОНАС-ФОТОН 30 января 2009 г. Прибор состоит из блока детекторов ПИНГВИН-МД (ПМД) и блока электроники ПИНГВИН-МЭ (ПМЭ). Цель эксперимента измерение степени линейной поляризации рентгеновского излучения солнечных вспышек в энергетическом диапазоне 20150 кэВ и энергетических спектров рентгеновского излучения солнечных вспышек в диапазоне энергий 2500 кэВ. В статье дается описание прибора, процедуры калибровки, полетной настройки и краткое описание первых результатов измерений.
The PINGVIN-M polarimeter was launched into orbit on January 31, 2009, as a part of the equipment of the KORONAS-FOTON Satellite. We discuss the results from recording solar flares using the PINGVIN-M polarimeter in the year 2009. We also consider the statistical characteristics of the recorded B- and C-class solar flares in terms of time, plasma temperature, and volume of emission.
The main characteristics of the PENGUIN-M instrument are given. The instrument has been operating aboard the CORONAS-PHOTON spacecraft (SC) launched into orbit on January 30, 2009. The instrument includes the PENGUIN-MD detector unit (PMD) and the PENGUIN-ME electronic unit (PMD). The purpose of the experiment is to measure the degree of linear polarization of X-ray radiation from solar flares in the energy range of 20–150 keV and to obtain energy spectra of X-ray radiation from solar flares in the energy range of 2–500 keV. The paper describes the instrument, calibration procedure, and in-flight adjustment, and contains the first results of measurements.