A Real Time Image Processing Subsystem: GEZGIN

In this study, a real-time image processing subsystem, GEZGIN, which is currently being developed for BILSAT-1, a 100kg class micro-satellite, is presented. BILSAT-1 is being constructed in accordance with a technology transfer agreement between TÜBITAK-BILTEN (Turkey) and SSTL (UK) and planned to be placed into a 650 km sunsynchronous orbit in Summer 2003. GEZGIN is one of the two Turkish R&D payloads to be hosted on BILSAT-1. One of the missions of BILSAT-1 is constructing a Digital Elevation Model of Turkey using both multi-spectral and panchromatic imagers. Due to limited down-link bandwidth and on-board storage capacity, employment of a realtime image compression scheme is highly advantageous for the mission. GEZGIN has evolved as an implementation to achieve image compression tasks that would lead to an efficient utilization of both the down-link and on-board storage. The image processing on GEZGIN includes capturing of 4-band multi-spectral images of size 2048x2048 8- bit pixels, compressing them simultaneously with the new industry standard JPEG2000 algorithm and forwarding the compressed multi-spectral image to Solid State Data Recorders (SSDR) of BILSAT-1 for storage and down-link transmission. The mission definition together with orbital parameters impose a 6.5 seconds constraint on real-time image compression. GEZGIN meets this constraint by exploiting the parallelism among image processing units and assigning compute intensive tasks to dedicated hardware. The proposed hardware also allows for full reconfigurability of all processing units

A real time, low latency, hardware implementation of the 2-D discrete wavelet transformation for streaming image applications

In this paper, we present a 2-D Discrete Wavelet Transformation (DWT) hardware for applications where row-based raw image data is streamed in at high bandwidths and local buffering of the entire image is not feasible. The latency that is introduced as the images stream through the DWT filter and the amount of locally stored image data is a function of the image and tile size. For an n(1) x n(2) size image processed using (n(1)/k(1)) x (n(2)/k(2)) sized tiles the latency is equal to the time elapsed to accumulate a (1/k(1)) portion of one image. In addition, a (2/k(1)) portion of each image is buffered locally. The proposed hardware has been implemented on an FPGA and is part of a JPEG2000 compression system designed as a payload for a Low Earth Orbit (LEO) micro-satellite, which will be launched in August 2003

A real time, low latency, FPGA implementation of the 2-D discrete wavelet transformation for streaming image applications

In this paper, we present an architecture and a hardware implementation of the 2-D Discrete Wavelet Transformation (DWT) for applications where row-based raw image data is streamed in at high bandwidths and local buffering of the entire image is not feasible. The architecture is especially suited for multi-spectral imager systems, such as on board an imaging satellite, however can be used in any application where time to next image constraints require real-time processing of multiple images. The latency that is introduced as the images stream through the DWT filter and the amount of locally stored image data is a function of the image and tile size. For an n(1) x n(2) size image processed using (n(1)/k(1)) x (n(2)/k(2)) sized tiles the latency is equal to the time elapsed to accumulate a (1/k(1)) portion of one image. In addition, a (2/k(1)) portion of each image is buffered locally. The proposed hardware has been implemented on an FPGA and is part of a JPEG2000 compression system designed as a payload for a Low Earth Orbit (LEO) micro-satellite, which will be launched in August 2003

The effect of propofol and thiopentone on impairment by reactive oxygen species of endothelium-dependent relaxation in rat aortic rings

The effect in isolated rat aorta of propofol, thiopentone, midazolam, etomidate and fentanyl on the impairment of endothelium-dependent relaxation by reactive oxygen species is reported. Aortic rings were exposed to reactive oxygen species by the electrolysis of the bathing physiological buffer, and endothelium-dependent relaxation in response to acetylcholine was inhibited. This inhibition was countered by incubation before electrolysis with propofol (2 x 10(-5) and 6 x 10(-5) M) or thiopentone (10(-5)-10(-4) M), but not with midazolam (3 x 10(-4) M), etomidate (3 x 10(-4) M) or fentanyl (3 x 10(-5) M). We suggest that the protective effect of propofol and thiopentone against the loss of endothelium-dependent relaxation caused by reactive oxygen species may be because of their antioxidant and free radical scavenging properties, which could be clinically relevant during surgical procedures in which ischaemia is unavoidable

Pathology teach and tell: Central nervous system atypical teratoid/rhabdoid tumor

Atypical teratoid/rhabdoid tumor (AT/RT) is extremely malignant, highly aggressive primitive central nervous systemneoplasm of infancy with very poor prognosis. Histologically, AT/RT is defined as a polymorphous neoplasm often featuring rhabdoid, PNET, mesenchymal, and epithelial components. We report the clinical history, radioligical, and pathological findings in a child affected bycentral nervous system AT/RT