Associated HI absorption in the z=3.4 radio galaxy B2 0902+343 observed with the GMRT

We have made observations of the associated HI absorption of a high redshift radio galaxy 0902+34 at z=3.395 with the Giant Meterwave Radio Telescope in the $323\pm1$ MHz band. We find a narrow absorption line with a flux density of 11.5 mJy at a redshift of 3.397 consistent with that observed by Uson et al. (1991), Briggs et al. (1993) and de Bruyn (1996).A weak broad absorption feature reported by de Bruyn (1996) has not been detected in our observations. We also place an upper limit of 4 mJy (2 $\sigma$) on emission line strength at the position where Uson et al. (1991) claimed to have found a narrow emission line.Comment: To appear in Journal of Astronomy and Astrophysic

Uloga istodobne primjene antioksidanata u sprječavanju oksidacijskih oštećenja uzrokovanih supkroničnom izloženošću štakora arsenu

In this experiment thirty rats were exposed to 0 (Gr. I, healthy controls) or 10 ppm arsenic (sodium arsenite) through drinking water ad lib for eight weeks after dividing them into five groups of six rats each. Rats in Gr. III, IV and V were administered a daily oral dose of cysteine, methionine or ascorbic acid 25 mg/kg body mass respectively, while those in Gr. II served as the treated control. At the end of the experimental period oxidative stress indices viz. lipid peroxides level (LPO), superoxide dismutase (SOD) and catalase (CAT) activities were estimated in blood, liver and kidneys from sacrificed rats. Arsenic exposure resulted in a significant (P0.05) effects on the body mass of rats of different groups over time. It is concluded from the present study that prophylactic co-administration of cysteine, methionine and ascorbic acid could provide tissue specific protection from oxidative injury during sub-chronic exposure to arsenicU istraživanju su štakori bili izloženi natrijevom arsenitu (10 ppm arsena) primijenjenom u vodi za piće tijekom 8 tjedana nakon čega su bili podijeljeni u 5 skupina po 6 štakora. Štakorima u skupinama 3, 4 i 5 oralnim je putem dnevno davan cistein, metionin ili askorbinska kiselina u količini od 25 mg/kg tjelesne mase. Štakori 2. skupine poslužili su kao kontrola. Na kraju pokusa određeni su pokazatelji oksidativnog stresa i to razina lipidnog peroksida, superoksidne dismutaze i katalaze u krvi, jetri i bubrezima. Izloženost arsenu očitovala se značajnim (P0,05) na tjelesnu masu štakora različitih skupina. Zaključeno je da istodobna profilaktička primjena cisteina, metionina ili askorbinske kiseline pruža specifičnu zaštitu tkiva od oksidacijskih oštećenja uzrokovanih supkroničnim izlaganjem arsenu

Uloga istodobne primjene antioksidanata u sprječavanju oksidacijskih oštećenja uzrokovanih supkroničnom izloženošću štakora arsenu

In this experiment thirty rats were exposed to 0 (Gr. I, healthy controls) or 10 ppm arsenic (sodium arsenite) through drinking water ad lib for eight weeks after dividing them into five groups of six rats each. Rats in Gr. III, IV and V were administered a daily oral dose of cysteine, methionine or ascorbic acid 25 mg/kg body mass respectively, while those in Gr. II served as the treated control. At the end of the experimental period oxidative stress indices viz. lipid peroxides level (LPO), superoxide dismutase (SOD) and catalase (CAT) activities were estimated in blood, liver and kidneys from sacrificed rats. Arsenic exposure resulted in a significant (P0.05) effects on the body mass of rats of different groups over time. It is concluded from the present study that prophylactic co-administration of cysteine, methionine and ascorbic acid could provide tissue specific protection from oxidative injury during sub-chronic exposure to arsenicU istraživanju su štakori bili izloženi natrijevom arsenitu (10 ppm arsena) primijenjenom u vodi za piće tijekom 8 tjedana nakon čega su bili podijeljeni u 5 skupina po 6 štakora. Štakorima u skupinama 3, 4 i 5 oralnim je putem dnevno davan cistein, metionin ili askorbinska kiselina u količini od 25 mg/kg tjelesne mase. Štakori 2. skupine poslužili su kao kontrola. Na kraju pokusa određeni su pokazatelji oksidativnog stresa i to razina lipidnog peroksida, superoksidne dismutaze i katalaze u krvi, jetri i bubrezima. Izloženost arsenu očitovala se značajnim (P0,05) na tjelesnu masu štakora različitih skupina. Zaključeno je da istodobna profilaktička primjena cisteina, metionina ili askorbinske kiseline pruža specifičnu zaštitu tkiva od oksidacijskih oštećenja uzrokovanih supkroničnim izlaganjem arsenu

A Comparative Study of Markov Network Structure Learning Methods Over Data Streams

Abstract-Markov network is a widely used graphical representation of data in applications such as natural language and computational biology. This undirected graph consists of nodes and edges as attributes and its dependencies respectively. One major challenge in a learning task involving Markov network is to learn its structure, i.e. attribute dependencies, from data. This has been the subject of various studies in the recent past, which uses heuristics to estimate dependencies from data. In this paper, we highlight the challenges of Markov network structure learning, and review existing methods addressing these challenges. In particular, we study the scalability of these heuristics over streaming data where data instances are assumed to occur continuously. Furthermore, we propose a new heuristic based on clustering of features, consisting of attribute dependencies, that can seamlessly update the model structure as new data arrive in a stream. This clustering technique effectively reduces search space and uses fewer number of features to generate a single model. Weight learning and inference is performed at the end of each data chunk consisting of data instances arriving within a fixed time frame. We empirically evaluate the proposed heuristic by comparing the CMLL score, on various datasets (both streaming and non-streaming), with other state-of-the-art methods

Kinetics of the Oxidation of Hydrogen Sulfide by Atmospheric Oxygen in an Aqueous Medium

Hydrogen sulfide is an important acid rain precursor and this led us to investigate the kinetics of its oxidation in aqueous phase by atmospheric oxygen. The kinetics was followed by measuring the depletion of oxygen in a reactor. The reaction was studied under pseudo order conditions with [H2S] in excess. The kinetics followed the rate law: -d[O2]/dt = k[S][O2]t (A) Where [S] represents the total concentration of hydrogen sulfide, [O2]t is the concentration of oxygen at time t and k is the second order rate constant. The equilibria (B - C) govern the dissolution of H2S; the sulfide ion in water forms different species: H2S K1 HS- + H+ (B) HS- K2 S2- + H+ (C) Where K1 and K2 are first and second dissociation constants of H2S. Although, H2S is present as undissociated H2S, HS- and S2- ions, nature of [H+ ] dependence of reaction rate required only HS- to be reactive and dominant. The rate law (A) on including [H+ ] dependence became Equation (D). -d[O2]/dt = k1K1[H+ ][S][O2]t / ([H+ ] 2 + K1[H+ ] + K1K2) (D) Our results indicate anthropogenic VOCs such as acetanilide, benzene, ethanol, aniline, toluene, benzamide, o-xylene, m-xylene, p-xylene and anisole to have no significant effect on the reaction rate and any observed small effect is within the uncertainty of the rate measurements

Physical properties of large cardamom cultivated in north eastern Himalayan region of Sikkim, India

The large cardamom is one of the most important spice crops grown in Himalayan region of Sikkim, India.  The capsules of the harvested large cardamom are dried before consumption.  The paper presents the physical properties of  freshly harvested and dried large cardamom capsules.  The geometrical mean diameter, sphericity, bulk density and mean values of angle of repose of the freshly harvested large cardamom capsules were observed to be 18.53±1.73 mm, 0.76, 332.21±14.24 kg m-3 and 28.74±4.04°, respectively.  Whereas for dried large cardamom capsules the values were found to be 11.113±0.92 mm, 0.56, 393.109±9.622 kg m-3 and 29.84±2.93°, respectively.  The peak static coefficient of friction of freshly harvested large cardamom over mild steel, plywood and plastic film surfaces were 0.386, 0.463 and 0.359, respectively.  However, for dried large cardamom capsules, the observed values were 0.436, 0.394 and 0.155, respectively.   Keywords: large cardamom, spice crop, physical propertie

On the origin of the various types of radio emission in GRS 1915+105

We investigate the association between the radio ``plateau'' states and the large superluminal flares in GRS 1915+105 and propose a qualitative scenario to explain this association. We identify several candidate superluminal flare events from available monitoring data on this source and analyze the contemporaneous RXTE pointed observations. We detect a strong correlation between the average X-ray flux during the ``plateau'' state and the total energy emitted in radio during the subsequent radio flare. We find that the sequence of events is similar for all large radio flares with a fast rise and exponential decay morphology. Based on these results, we propose a qualitative scenario in which the separating ejecta during the superluminal flares are observed due to the interaction of the matter blob ejected during the X-ray soft dips, with the steady jet already established during the ``plateau'' state. This picture can explain all types of radio emission observed from this source in terms of its X-ray emission characteristics.Comment: Corrected typo in the author names, contents unchanged, accepted in Ap

Evidence for Synchrotron Bubbles from GRS 1915+105

We present GMRT observations of the Galactic microquasar GRS 1915+105 at 1.28 GHz for 8 days from 2001 June 18 to July 1. We have seen several isolated radio flares of varying magnitudes (20 - 50 mJy) and durations (6 - 35 min) and we model them as due to adiabatically expanding synchrotron emitting clouds (synchrotron bubbles) ejected from the accretion disk. By applying this model, we provide a new method to estimate the electron power-law index p, hence the spectral index, from single frequency radio observations. This method does not require correction for the optical depth time delay effects which may be important in the case of optically thick radio emission. Using our estimated value of p and simultaneous multiwavelength data from literature, we have calculated the time of ejection of the synchrotron plasma and the time delays at different observed frequencies. Our estimates are in good agreement with the observed time delays.Comment: Accepted for publication in A&A Letter