A late, infrared flash from the afterglow of GRB 050319

We report the detection of a bright, near-infrared flash from the afterglow of GRB 050319, 6.15 hours after the burst. The IR flash faded rapidly from J=13.12 mag. to J > 15.5 mag. in about 4 minutes. There are no reported simultaneous observations at other wavelengths making it an unique event. We study the implications of its late timing in the context of current theoretical models for GRB afterglows.Comment: Accepted in ApJ (Letters

University small satellite program-ANUSAT

Indian Space Research Organization (ISRO) over the last 3 decades has steadily progressed towards establishment of space system for communication, Earth observation and disaster warning for national development. Also, the launchers for placing both Earth observation and communication satellites have been developed. While these efforts are being sustained on a continuous basis, ISRO initiated Small Satellite Program few years ago for demonstration of new technologies that can be adopted to operational mission as well as Small Satellite Earth Observation program to complement the existing earth observation mission. Also realizing the importance of steady flow of engineers and scientists in Space Technology, ISRO has been pursuing to promote development of micro-satellite at Indian universities that will provide hands-on experience to the university students in Space Technology and also developing new technologies for the future. Anna University at Chennai, India, has taken up the first micro-satellite program within the university environment. The micro-satellite development will be carried out at Aerospace Research Centre in Anna University with review and funding support from ISRO. The project will be implemented through involvement of students, researchers and faculty staff. The satellite is a simple spinning satellite carrying store and forward payload being the first mission and weighs less than 50 kg. The Project has commenced in January 2002. The preliminary design review of the satellite has been completed in December 2002. The micro-satellite is scheduled for launch in 2005 as an auxiliary payload in ISRO's launcher PSLV (Polar Satellite Launch Vehicle)

Removal of turbidity from washing machine discharge using Strychnos potatorum seeds: Parameter optimization and mechanism prediction

In this research an attempt has been made to utilize the Strychnos potatorum seed powder as an environmentally friendly coagulant for the removal of turbidity from washing machine discharge. The performance of this system was also compared with synthetic water. Experimental studies were conducted for the maximum removal of turbidity from washing machine discharge and synthetic turbid water which were varied from 50 to 145 NTU. The effect of operating parameters such as initial turbidity, S. potatorum dosage and pH of the solution was optimized for the maximum removal of turbidity. It was seen that the percentage removal of turbidity lay was between 68-89% and 65-84% for synthetic turbid water and washing machine discharge sample respectively, at an ideal pH of 6-7. The experimental values were compared with the Langmuir and Freundlich isotherm models to understand the extent of influence of the sorption of the particles onto the S. potatorum seed powder. Better results with respect to concordance of experimental data were observed with Langmuir isotherm model, indicating a monolayer sorption of particles onto the S. potatorum seed powder. It was observed from the isotherm study that the sorption may also be influenced in the removal of turbidity to some extent from the washing machine discharge and synthetic water. The prepared material can be effectively utilized for the removal of turbidity from the water

Multiscale Autoregressive Identification of Neuroelectrophysiological Systems

Electrical signals between connected neural nuclei are difficult to model because of the complexity and high number of paths within the brain. Simple parametric models are therefore often used. A multiscale version of the autoregressive with exogenous input (MS-ARX) model has recently been developed which allows selection of the optimal amount of filtering and decimation depending on the signal-to-noise ratio and degree of predictability. In this paper, we apply the MS-ARX model to cortical electroencephalograms and subthalamic local field potentials simultaneously recorded from anesthetized rodent brains. We demonstrate that the MS-ARX model produces better predictions than traditional ARX modeling. We also adapt the MS-ARX results to show differences in internuclei predictability between normal rats and rats with 6OHDA-induced parkinsonism, indicating that this method may have broad applicability to other neuroelectrophysiological studies

Evaluation of a Cold Staining Method for Acid-Fast Bacilli in Sputum

Comparison between the Ziehl-Neelscn staining method for acid-fast bacilli, applied with and without heating, was carried out in a controlled investigation using smears prepared from 306 sputum samples collected prior to treatment from suspected cases of pulmonary tuberculosis. Smear and culture positively were graded and the colour intensity of bacilli recorded. Results showed that the chance corrected agreement (Kappa) between Z-N and cold methods was only 78%. The sensitivity of the Z-N and cold methods were 84% and 77% respectively when compared with culture results. Assuming 10% smear positivity among symptomatics reporting to Peripheral Health Institutions (PHIs), the positive predictive value of the cold method was very low(53%). When compared to culture, the positive predictive value is 71% for the Z-N method and 57% for the cold method for a symptomatic population with 15% culture positivity. In the absence of heating. penetration of the stain was significantly reduced and consequently the number of bacilli detected was less. The inability to take the stain without heating was seen in smears from all grades of culture positive samples: thus even heavy positives were missed by the cold method. The evaluation of the cold method against the standard Z-N method highlights its limitations and demonstrates that it is not as reliable as the standard Z-N method

A case of valproate induced non-hepatic hyperammonemic encephalopathy

Sodium valproate is a broad spectrum anticonvulsant. Valproate induced hyperammonemic encephalopathy with normal liver function is a serious, but less common entity