Utilization of Immunoblotting in Studies of Epitope Targeting in Monoclonal Antibodies to Melioidosis Agent Antigen 200 kDa

Objective of the research was to use immunoblotting for studies of epitope targeting in monoclonal antibodies to 200 kDa Burkholderia pseudomallei antigen, which are synthesized by hybridomas-producers from the two collections in the laboratory of immunodiagnostics and biotechnology at the premises of Volgograd Research Anti-Plague Institute. Employed were 8 typical strains of melioidosis agent with the complete antigenic structure. Antigen preparations were separated by means of denaturating vertical electrophoresis in 12 % polyacrylamide gel with 0.1 % sodium dodecylsulfate. During the process of cell-replication, 12 hybridomas-producers were given preparative amounts of monoclonal antibodies to 200 kDa Burkholderia pseudomallei glycoprotein. Following that, immunoperoxidase conjugates were manufactured. Epitope targeting of monoclonal antibodies was evaluated using immunoblotting. With the help of vertical electrophoresis identified was the presence of several mandatory major components contained in the antigen complexes of the salt-water and formamid B. pseudomallei extracts . Differential staining substantiated glycoprotein origin of certain antigen components. Immunoblotting with the stated above antigen preparations revealed epitope targeting of a number of monoclonal antibodies to 200 kDa antigen of melioidosis agent; demonstrated were the differences in their specific interaction with biopolymers which form part of the antigen specter. Those differences were characteristic of hybridomas-producers belonging to different collections, as well as of particular strains of B. pseudomallei

Influence of geometrical parameters on transmitting thermal radiation through silver halide fibers

In this study, we experimentally determined the influence of fibers’ geometrical parameters on the performance of fiber-optic temperature control system based on silver halide fibers at the temperatures of 295–395 K. It was revealed that the fiber diameter can affect thermal radiation transmission in the case of mismatching light beam diameters between system's optical elements and it should be taken into consideration when such systems are developed. A fiber length reduction leads to a linear increase in transmission values. We also assessed transmission losses for the fibers bent at various radii and derived some empirical equations for calibration curves. The revealed dependencies can be very useful for designing fiber-optic systems intended for remote temperature measurements and control of heating-power facilities’ thermal regimes. © 2020 The AuthorsRussian Science Foundation, RSF: 18-73-10063This work was supported by the Russian Science Foundation under grant No. 18-73-10063

A strategy to characterize the LISA-Pathfinder cold gas thruster system

The cold gas micro-propulsion system that will be used during the LISA-Pathfinder mission will be one of the most important component used to ensure the "free-fall" of the enclosed test masses. In this paper we present a possible strategy to characterize the effective direction and amplitude gain of each of the 6 thrusters of this system

Free-flight experiments in LISA Pathfinder

The LISA Pathfinder mission will demonstrate the technology of drag-free test masses for use as inertial references in future space-based gravitational wave detectors. To accomplish this, the Pathfinder spacecraft will perform drag-free flight about a test mass while measuring the acceleration of this primary test mass relative to a second reference test mass. Because the reference test mass is contained within the same spacecraft, it is necessary to apply forces on it to maintain its position and attitude relative to the spacecraft. These forces are a potential source of acceleration noise in the LISA Pathfinder system that are not present in the full LISA configuration. While LISA Pathfinder has been designed to meet it's primary mission requirements in the presence of this noise, recent estimates suggest that the on-orbit performance may be limited by this `suspension noise'. The drift-mode or free-flight experiments provide an opportunity to mitigate this noise source and further characterize the underlying disturbances that are of interest to the designers of LISA-like instruments. This article provides a high-level overview of these experiments and the methods under development to analyze the resulting data.Comment: 13 pages, 5 figures. Accepted to Journal Of Physics, Conference Series. Presented at 10th International LISA Symposium, May 2014, Gainesville, FL, US

In-flight thermal experiments for LISA pathfinder: simulating temperature noise at the inertial sensors

Thermal Diagnostics experiments to be carried out on board LISA Pathfinder (LPF) will yield a detailed characterisation of how temperature fluctuations affect the LTP (LISA Technology Package) instrument performance, a crucial information for future space based gravitational wave detectors as the proposed eLISA. Amongst them, the study of temperature gradient fluctuations around the test masses of the Inertial Sensors will provide as well information regarding the contribution of the Brownian noise, which is expected to limit the LTP sensitivity at frequencies close to 1 mHz during some LTP experiments. In this paper we report on how these kind of Thermal Diagnostics experiments were simulated in the last LPF Simulation Campaign (November, 2013) involving all the LPF Data Analysis team and using an end-to-end simulator of the whole spacecraft. Such simulation campaign was conducted under the framework of the preparation for LPF operations

The LISA pathfinder mission

ISA Pathfinder (LPF), the second of the European Space Agency's Small Missions for Advanced Research in Technology (SMART), is a dedicated technology validation mission for future spaceborne gravitational wave detectors, such as the proposed eLISA mission. LISA Pathfinder, and its scientific payload - the LISA Technology Package - will test, in flight, the critical technologies required for low frequency gravitational wave detection: it will put two test masses in a near-perfect gravitational free-fall and control and measure their motion with unprecedented accuracy. This is achieved through technology comprising inertial sensors, high precision laser metrology, drag-free control and an ultra-precise micro-Newton propulsion system. LISA Pathfinder is due to be launched in mid-2015, with first results on the performance of the system being available 6 months thereafter. The paper introduces the LISA Pathfinder mission, followed by an explanation of the physical principles of measurement concept and associated hardware. We then provide a detailed discussion of the LISA Technology Package, including both the inertial sensor and interferometric readout. As we approach the launch of the LISA Pathfinder, the focus of the development is shifting towards the science operations and data analysis - this is described in the final section of the paper

A noise simulator for eLISA: migrating LISA pathfinder knowledge to the eLISA mission

We present a new technical simulator for the eLISA mission, based on state space modeling techniques and developed in MATLAB. This simulator computes the coordinate and velocity over time of each body involved in the constellation, i.e. the spacecraft and its test masses, taking into account the different disturbances and actuations. This allows studying the contribution of instrumental noises and system imperfections on the residual acceleration applied on the TMs, the latter reflecting the performance of the achieved free-fall along the sensitive axis. A preliminary version of the results is presented

State space modelling and data analysis exercises in LISA Pathfinder

LISA Pathfinder is a mission planned by the European Space Agency to test the key technologies that will allow the detection of gravitational waves in space. The instrument on-board, the LISA Technology package, will undergo an exhaustive campaign of calibrations and noise characterisation campaigns in order to fully describe the noise model. Data analysis plays an important role in the mission and for that reason the data analysis team has been developing a toolbox which contains all the functionalities required during operations. In this contribution we give an overview of recent activities, focusing on the improvements in the modelling of the instrument and in the data analysis campaigns performed both with real and simulated data.Comment: Plenary talk presented at the 9th International LISA Symposium, 21-25 May 2012, Pari

Disentangling the magnetic force noise contribution in LISA pathfinder

Magnetically-induced forces on the inertial masses on-board LISA Pathfinder are expected to be one of the dominant contributions to the mission noise budget, accounting for up to 40%. The origin of this disturbance is the coupling of the residual magnetization and susceptibility of the test masses with the environmental magnetic field. In order to fully understand this important part of the noise model, a set of coils and magnetometers are integrated as a part of the diagnostics subsystem. During operations a sequence of magnetic excitations will be applied to precisely determine the coupling of the magnetic environment to the test mass displacement using the on-board magnetometers. Since no direct measurement of the magnetic field in the test mass position will be available, an extrapolation of the magnetic measurements to the test mass position will be carried out as a part of the data analysis activities. In this paper we show the first results on the magnetic experiments during an end- to-end LISA Pathfinder simulation, and we describe the methods under development to map the magnetic field on-board