Qualitative Study of Anisotropic Cosmological Models with Dark Sector Coupling

In this paper, we study the dynamical evolution of LRS Bianchi type I cosmological model with coupling of dark sector. We investigate the phase-plane analysis when dark energy is modelled as exponential quintessence, and is coupled to dark energy matter via linear coupling between both dark components. The evolution of cosmological solutions is studied by using dynamical systems techniques. Stability and viability issues for three different physically viable linear coupling between both dark components are presented and discussed in detail.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Qualitative aspects of Rastall gravity with barotropic fluid

We investigate the dynamical evolution of homogeneous and isotropic flat-FRW universe filled with a barotropic fluid satisfying linear equation of state in Rastall gravity. Using dynamical system approach, we find the fixed points of the system and study their stability. We further explore the thermodynamic aspects at the apparent horizon by investigating the validity of generalized second law of thermodynamics with equilibrium description.The accepted manuscript in pdf format is listed with the files at the bottom of this page. The presentation of the authors' names and (or) special characters in the title of the manuscript may differ slightly between what is listed on this page and what is listed in the pdf file of the accepted manuscript; that in the pdf file of the accepted manuscript is what was submitted by the author

Isolation and characterization of meta-toluic acid degrading marine bacterium

322-325The analysis of the sea water samples using sequential enrichment technique revealed a report of marine bacterium capable of degrading meta toluic acid a component of crude oil. An attempt to characterize the isolated culture using biochemical tests indicated the culture as a Gram- negative aerobic rod that was highly motile exhibiting biodegrading ability and was identified as Pseudomonas spp. strain GUI13. Further, a comparative analysis of the biochemical characters with the archae type terrestrial soil bacterium indicated that the isolate required marked amounts of Sodium chloride (NaCl) in the medium to retain its viability. Substrate constant (Ks) of strain GUI13 with respect to meta toluic acid was found to be eight times lower when compared to that of a terrestrial bacterium. A similar ratio was observed in case of Michaelis constants (Km) for the key degradative enzyme, Catechol 2,3 dioxygenase, emphasizing the distinguishing feature of the marine bacteria that helps it to carry on the process of bio transformations at very low concentrations of carbon, a unique condition that exists in the sea

A randomized controlled study comparing intrathecal hyperbaric bupivacaine-fentanyl mixture and isobaric bupivacaine-fentanyl mixture in common urological procedures

Background and Aims: Bupivacaine is available in isobaric and hyperbaric forms for intrathecal use and opioids are used as additives to modify their effects. The aim of this study was to compare the efficacy and haemodynamic effect of intrathecal isobaric bupivacaine-fentanyl mixture and hyperbaric bupivacaine-fentanyl mixture in common urological procedures. Methods: One hundred American Society of Anesthesiologists physical status 1 and 2 patients undergoing urological procedures were randomized into two groups. Group 1 received 3 ml of 0.5% isobaric bupivacaine with 25 μg fentanyl while Group 2 received 3 ml of 0.5% hyperbaric bupivacaine with 25 μg fentanyl. The parameters measured include heart rate, blood pressure, respiratory rate, onset and duration of motor and sensory blockade. Student's unpaired t-test and the χ2 test were used to analyse the results, using the SPSS version 11.5 software. Results: The haemodynamic stability was better with isobaric bupivacaine fentanyl mixture (Group 1) than with hyperbaric bupivacaine fentanyl mixture (Group 2).The mean onset time in Group 1 for both sensory block (4 min) and motor block (5 min) was longer compared with Group 2. The duration of sensory block (127.8 ± 38.64 min) and motor block (170.4 ± 27.8 min) was less with isobaric bupivacaine group compared with hyperbaric bupivacaine group (sensory blockade 185.4 ± 16.08 min and motor blockade 201.6 ± 14.28 min). Seventy percent of patients in Group 2 had maximum sensory block level of T6whereas it was 53% in Group 1. More patients in Group 1 required sedation compared to Group 2. Conclusion: Isobaric bupivacaine fentanyl mixture was found to provide adequate anaesthesia with minimal incidence of haemodynamic instability