A review of type Ia supernova spectra

SN 2011fe was the nearest and best-observed type Ia supernova in a generation, and brought previous incomplete datasets into sharp contrast with the detailed new data. In retrospect, documenting spectroscopic behaviors of type Ia supernovae has been more often limited by sparse and incomplete temporal sampling than by consequences of signal-to-noise ratios, telluric features, or small sample sizes. As a result, type Ia supernovae have been primarily studied insofar as parameters discretized by relative epochs and incomplete temporal snapshots near maximum light. Here we discuss a necessary next step toward consistently modeling and directly measuring spectroscopic observables of type Ia supernova spectra. In addition, we analyze current spectroscopic data in the parameter space defined by empirical metrics, which will be relevant even after progenitors are observed and detailed models are refined.Comment: 58 pages, 15 figures, 6 tables, accepted for publication in Ap&SS as an invited revie

Data Catalog Series for Space Science and Applications Flight Missions

The main purpose of the data catalog series is to provide descriptive references to data generated by space science flight missions. The data sets described include all of the actual holdings of the Space Science Data Center (NSSDC), all data sets for which direct contact information is available, and some data collections held and serviced by foreign investigators, NASA and other U.S. government agencies. This volume contains narrative descriptions of data sets from geostationary and high altitude scientific spacecraft and investigations. The following spacecraft series are included: Mariner, Pioneer, Pioneer Venus, Venera, Viking, Voyager, and Helios. Separate indexes to the planetary and interplanetary missions are also provided

Study on the changes in the levels of membrane-bound ATPases activity and some mineral status in λ cyhalothrin-induced hepatotoxicity in fresh water tilapia (Oreochromis Mossambicus)

An attempt has been made to determine the deleterious effects of λ cyhalothrin- induced in fresh water tilapia (Oreochromis mossambicus) with respect to changes in the activities of membrane-bound ATPases (Na<sup>+</sup>/K<sup>+</sup>, Mg<sup>+</sup> and Ca<sup>2+</sup> ATPase) and mineral status (sodium, potassium and calcium) in the liver. Significant (p<0.05) decline in the activities of membrane-bound ATPases and mineral status was observed in λ cyhalothrin-intoxicated fishes as compared to controls. A concomitant (P<0.05) elevation in the level of lipid peroxidation in liver was also observed. The results of the present investigation have indicated that the toxic effect of λ cyhalothrin-induced in fresh water tilapia (Oreochromis mossambicus) might be ascribable to its membrane destabilizing property or peroxidative action. Histopathological studies also proved its toxic potential in terms of the damage induced at organ level.Key words: Histopathology, liver, λ cyhalothrin, membrane-bound ATPases, mineral status, Oreochromis Mossambicus

Studies on the hepatic antioxidant defense system in λ cyhalothrin-induced oxidative stress in fresh water tilapia (Oreochromis mossambicus)

The present study was undertaken to determine the effects of λ cyhalothrin-induced oxidative stress in fresh water tilapia (Oreochromis mossambicus) with respect to changes in the levels of lipid peroxidation [LPO], reduced glutathione [GSH], glutathione-dependent antioxidant enzymes (glutathione peroxidase [GPX] and glutathione-S-transferase [GST]) and antiperoxidative enzymes (catalase [CAT] and superoxide dismutase [SOD]). Significant (P<0.05) elevation in the level of lipid peroxidation was observed in λ cyhalothrin-intoxicated fishes as compared to controls. A concomitant (P<0.05) decline in hepatic antioxidant status was also observed. The results of the present investigation have indicated that the tissue antioxidant defense system is operating at a lower rate despite increased λ cyhalothrin-induced oxidative stress.Key words: Antioxidant status, λ cyhalothrin, lipid peroxidation, Oreochromis mossambicus, oxidative stress, synthetic pyrethroid

New determination of abundances and stellar parameters for a set of weak G-band stars

Weak G-band (wGb) stars are very peculiar red giants almost devoided of carbon and often mildly enriched in lithium. Despite their very puzzling abundance patterns, very few detailed spectroscopic studies existed up to a few years ago, preventing any clear understanding of the wGb phenomenon. We recently proposed the first consistent analysis of published data for 28 wGb stars and identified them as descendants of early A-type to late B-type stars, without being able to conclude on their evolutionary status or the origin of their peculiar abundance pattern. We used newly obtained high-resolution and high SNR spectra for 19 wGb stars in the southern and northern hemisphere to homogeneously derive their fundamental parameters, metallicities, as well as the spectroscopic abundances for Li, C, N, O, Na, Sr, and Ba. We also computed dedicated stellar evolution models that we used to determine the masses and to investigate the evolutionary status and chemical history of the stars in our sample. We confirm that the wGb stars are stars in the mass range 3.2 to 4.2 M$_\odot$. We suggest that a large fraction could be mildly evolved stars on the SGB currently undergoing the 1st DUP, while a smaller number of stars are more probably in the core He burning phase at the clump. After analysing their abundance pattern, we confirm their strong N enrichment anti-correlated with large C depletion, characteristic of material fully processed through the CNO cycle to an extent not known in other evolved intermediate-mass stars. However, we demonstrate here that such a pattern is very unlikely due to self-enrichment. In the light of the current observational constraints, no solid self-consistent pollution scenario can be presented either, leaving the wGb puzzle largely unsolved.Comment: 19 pages , 14 figures, accepted for publication in Astronomy & Astrophysic

Continuous Spinal Anaesthesia- A need for a re-emergence?

Continuous spinal anaesthesia is the technique of producing and maintaining spinal anaesthesia with small doses of local anaesthetic injected intermittently into the subarachnoid space through a catheter. As the injection is intermittently given than continuous, intermittent or fractionated spinal anaesthesia is a more appropriate word than the routinely used continuous spinal anaesthesia. The history starts from 1906 when it was administered first by Dean. There are numerous surgical and obstetric indications for the use of the same apart from chronic pain. The equipment and technique are cumbersome in many instances. The detailed advantages outweigh complications. Still there is a thought block among anaesthesiologists regarding its use. With the resurgence of regional anaesthesia worldwide, the technique may have a re-emergence to be more commonly used in the coming years

Open Access Increases Citation Rate

PLoS Biology has published a research article that investigates a bibliometric rather than a biological question: do open-access articles have a citation advantage