149 research outputs found
Development of a scalable generic platform for adaptive optics real time control
The main objective of the present project is to explore the viability of an
adaptive optics control system based exclusively on Field Programmable Gate
Arrays (FPGAs), making strong use of their parallel processing capability. In
an Adaptive Optics (AO) system, the generation of the Deformable Mirror (DM)
control voltages from the Wavefront Sensor (WFS) measurements is usually
through the multiplication of the wavefront slopes with a predetermined
reconstructor matrix. The ability to access several hundred hard multipliers
and memories concurrently in an FPGA allows performance far beyond that of a
modern CPU or GPU for tasks with a well defined structure such as Adaptive
Optics control. The target of the current project is to generate a signal for a
real time wavefront correction, from the signals coming from a Wavefront
Sensor, wherein the system would be flexible to accommodate all the current
Wavefront Sensing techniques and also the different methods which are used for
wavefront compensation. The system should also accommodate for different data
transmission protocols (like Ethernet, USB, IEEE 1394 etc.) for transmitting
data to and from the FPGA device, thus providing a more flexible platform for
Adaptive Optics control. Preliminary simulation results for the formulation of
the platform, and a design of a fully scalable slope computer is presented.Comment: Paper presented as part of SPIE ICOP 2015 Conference Proceeding
UNICS - An Unified Instrument Control System for Small/Medium Sized Astronomical Observatories
Although the astronomy community is witnessing an era of large telescopes,
smaller and medium sized telescopes still maintain their utility being larger
in numbers. In order to obtain better scientific outputs it is necessary to
incorporate modern and advanced technologies to the back-end instruments and to
their interfaces with the telescopes through various control processes. However
often tight financial constraints on the smaller and medium size observatories
limit the scope and utility of these systems. Most of the time for every new
development on the telescope the back-end control systems are required to be
built from scratch leading to high costs and efforts. Therefore a simple, low
cost control system for small and medium size observatory needs to be developed
to minimize the cost and efforts while going for the expansion of the
observatory. Here we report on the development of a modern, multipurpose
instrument control system UNICS (Unified Instrument Control System) to
integrate the controls of various instruments and devices mounted on the
telescope. UNICS consists of an embedded hardware unit called Common Control
Unit (CCU) and Linux based data acquisition and User Interface. The Hardware of
the CCU is built around the Atmel make ATmega 128 micro-controller and is
designed with a back-plane, Master Slave architecture. The Graphical User
Interface (GUI) has been developed based on QT and the back end application
software is based on C/C++. UNICS provides feedback mechanisms which give the
operator a good visibility and a quick-look display of the status and modes of
instruments. UNICS is being used for regular science observations since March
2008 on 2m, f/10 IUCAA Telescope located at Girawali, Pune India.Comment: Submitted to PASP, 10 Pages, 5 figure
Involvement of CYP347W1 in neurotoxin 3-nitropropionic acid based chemical defense in mustard leaf beetle Phaedon cochleariae
A common theme in extracellular fluids of beetles: extracellular superoxide dismutases crucial for balancing ROS in response to microbial challenge
Extracellular Cu/Zn superoxide dismutases (SODs) are critical for balancing the level of reactive oxygen species in the extracellular matrix of eukaryotes. In the present study we have detected constitutive SOD activity in the haemolymph and defensive secretions of different leaf beetle species. Exemplarily, we have chosen the mustard leaf beetle, Phaedon cochleariae, as representative model organism to investigate the role of extracellular SODs in antimicrobial defence. Qualitative and quantitative proteome analyses resulted in the identification of two extracellular Cu/Zn SODs in the haemolymph and one in the defensive secretions of juvenile P. cochleariae. Furthermore, quantitative expression studies indicated fat body tissue and defensive glands as the main synthesis sites of these SODs. Silencing of the two SODs revealed one of them, PcSOD3.1, as the only relevant enzyme facilitating SOD activity in haemolymph and defensive secretions in vivo. Upon challenge with the entomopathogenic fungus, Metarhizium anisopliae, PcSOD3.1-deficient larvae exhibited a significantly higher mortality compared to other SOD-silenced groups. Hence, our results serve as a basis for further research on SOD regulated host-pathogen interactions. In defensive secretions PcSOD3.1-silencing affected neither deterrent production nor activity against fungal growth. Instead, we propose another antifungal mechanism based on MRJP/yellow proteins in the defensive exudates
High-efficiency Autonomous Laser Adaptive Optics
As new large-scale astronomical surveys greatly increase the number of
objects targeted and discoveries made, the requirement for efficient follow-up
observations is crucial. Adaptive optics imaging, which compensates for the
image-blurring effects of Earth's turbulent atmosphere, is essential for these
surveys, but the scarcity, complexity and high demand of current systems limits
their availability for following up large numbers of targets. To address this
need, we have engineered and implemented Robo-AO, a fully autonomous laser
adaptive optics and imaging system that routinely images over 200 objects per
night with an acuity 10 times sharper at visible wavelengths than typically
possible from the ground. By greatly improving the angular resolution,
sensitivity, and efficiency of 1-3 m class telescopes, we have eliminated a
major obstacle in the follow-up of the discoveries from current and future
large astronomical surveys.Comment: Published in ApJL. 6 pages, 4 figures, and 1 tabl
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