Phase transitions and bubble nucleations for a phi^6 model in curved spacetime

Condsidering a massive self-interacting phi ^6 scalar field coupled arbitrarily to a (2+1) dimensional Bianchi type-I spacetime, we evaluate the one-loop effective potential. It is found that phi ^6 potential can be regularized in (2+1) dimensional curved spacetime. A finite expression for the energy-momentum tensor is obtained for this model. Evaluating the finite temperature effective potential, the temperature dependence of phase transitions is studied. The crucial dependence of the phase transitions on the spacetime curvature and on the coupling to gravity are also verified. We also discuss the nucleation of bubbles in a phi ^6 model. It is found that there exists an exact solution for the damped motion of the bubble in the thin wall regime.Comment: 15 pages, 6 figure

Fishing the marine food web along the Indian coast

The annual mean trophic level (TrL) of marine fish landings along the Indian coast consisting of 53 exploited species/groups was estimated for the period 1950–2002. The landings as well as TrL increased along the northwest (NW) and southwest (SW) coasts. However, increase in the landings was associated with decrease in mean TrL along the east coast, particularly along the southeast (SE) coast at the rate of 0.04 per decade. The increasing trend of the FIB index ceased in the last 5–10 years along three coasts. A backward-bending signature in the landings versus TrL plot for the SE coast in the last 6 years indicates fisheries-induced changes in the ecosystem owing to low productivity of the coastal waters and high density of fishing craft. The landings of most of the large predators increased along the Indian coast, but higher removals appear to have helped proliferation of their prey, the mid-level carnivores. Fishing the food web has been influenced by environmental fluctuations, advanced fishing technologies, and market-driven, deliberate fishing on low-trophic level (TL) invertebrates such as the penaeid prawns

Scaffold-based lung tumor culture on porous PLGA microparticle substrates

Scaffold-based cancer cell culture techniques have been gaining prominence especially in the last two decades. These techniques can potentially overcome some of the limitations of current three-dimensional cell culture methods, such as uneven cell distribution, inadequate nutrient diffusion, and uncontrollable size of cell aggregates. Porous scaffolds can provide a convenient support for cell attachment, proliferation and migration, and also allows diffusion of oxygen, nutrients and waste. In this paper, a comparative study was done on porous poly (lactic-co-glycolic acid) (PLGA) microparticles prepared using three porogens—gelatin, sodium bicarbonate (SBC) or novel poly N-isopropylacrylamide [PNIPAAm] particles, as substrates for lung cancer cell culture. These fibronectin-coated, stable particles (19–42 μm) supported A549 cell attachment at an optimal cell seeding density of 250,000 cells/ mg of particles. PLGA-SBC porous particles had comparatively larger, more interconnected pores, and favored greater cell proliferation up to 9 days than their counterparts. This indicates that pore diameters and interconnectivity have direct implications on scaffold-based cell culture compared to substrates with minimally interconnected pores (PLGA-gelatin) or pores of uniform sizes (PLGA-PMPs). Therefore, PLGA-SBC-based tumor models were chosen for preliminary drug screening studies. The greater drug resistance observed in the lung cancer cells grown on porous particles compared to conventional cell monolayers agrees with previous literature, and indicates that the PLGA-SBC porous microparticle substrates are promising for in vitro tumor or tissue development

Status of marine fish stock assessment in India and development of a sustainability index

India has a coastline of 8129 km. Landings by commercial fishing vessels takes place at 1332 centres during day and night by 58,911 mechanized craft, 75,591 motorized (with outboard engine) and 104,270 traditional craft (CMFRI, 2006). Marine fisheries are an important source of food, employment and foreign exchange. About one million people work directly in this sector, producing 3 million tonnes annually valued at about 3 billion US $at production level (CMFRI, 2007). India earns 1.6 billion US$ by exporting fish and fishery products. India is among the top ten fish producing countries of the world, contributing 3.5% to the total world marine fish production. Concerned about the status of marine fish stocks in the Indian EEZ, the country has put in place appropriate institutional mechanisms to monitor and forecast fishery yields for the last 25 year

Interferon-inducible guanylate-binding proteins at the interface of cell-autonomous immunity and inflammasome activation

Guanylate-binding proteins (GBPs) are essential components of cell-autonomous immunity. In response to IFN signaling, GBPs are expressed in the cytoplasm of immune and nonimmune cells, where they unleash their antimicrobial activity toward intracellular bacteria, viruses, and parasites. Recent studies have revealed that GBPs are essential for mediating activation of the caspase-1 inflammasome in response to the gram-negative bacteria Salmonella enterica serovar Typhimurium, Francisella novicida, Chlamydia muridarum, Chlamydia trachomatis, Legionella pneumophila, Vibrio cholerae, Enterobacter cloacae, and Citrobacter koseri. During infection with vacuolar-restricted gram-negative bacteria, GBPs disrupt the vacuolar membrane to ensure liberation of LPS for cytoplasmic detection by caspase-11 and the noncanonical NLRP3 inflammasome. In response to certain cytosolic bacteria, GBPs liberate microbial DNA for activation of the DNA-sensing AIM2 inflammasome. GBPs also promote the recruitment of antimicrobial proteins, including NADPH oxidase subunits and autophagy-associated proteins to the Mycobacteriumcontaining vacuole to mediate intracellular bacterial killing. Here, we provide an overview on the emerging relationship between GBPs and activation of the inflammasome in innate immunity to microbial pathogens.This work was supported by the U.S. National Institutes of Health (NIH) National Institute of Allergy and Infectious Diseases Grants AI101935, AI124346; NIH National Institute of Arthritis and Musculoskeletal and Skin Diseases Grant AR056296; and NIH National Cancer Institute Grant CA163507 (to T.D.K.); the American Lebanese Syrian Associated Charities (to T.D.K.); and the R.G. Menzies Early Career Fellowship from the National Health and Medical Research Council of Australia (to S.M.M.

Fishery, biology and dynamics of dogtooth tuna, Gymnosarda unicolor (Rüppell, 1838) exploited from Indian seas

Dogtooth tuna, Gymnosarda unicolor (Rüppell, 1838) (Fig. 1) is a pelagic tuna preferring waters of temperature between 21 and 26 oC. It is one of the principal species exploited by hook and line (recreational as well as commercial fishery) operated in the oceanic region. Meat of dogtooth tuna is white and so it has great demand and fetch high price (IUCN, 2011). However, occasional ciguatera fish poisoning in humans has been reported on consumption of dogtooth tuna. It is exported in fresh and frozen state and is used for the production of sashimi, canned tuna, and pouch products. Most of the world landings of dogtooth tuna during 1963 -2006 was from the Indian Ocean. Small scale tuna long lines for the species operating in the Indian Ocean belong to Taiwan, Srilanka, Maldives, Japan or Pakista

Indian tuna fishery - production trend during yesteryears and scope for the future

Fishery for tuna and tuna like fishes in the country has been in vogue from time immemorial and presently involves fishery by coastal based fleets of varying specifications with different craft-gear combinations and longline fishery by large oceanic fishing vessels. The former undertakes short duration fishing trips and exploit mainly surface tunas in the outer shelf and adjacent oceanic waters. The tuna landings though nominal during 1950-2005, registered a continuous increase over the years from a minimum of 848 t (1951) to 46,334 t (2000). With the introduction of targeted fishing for oceanic tunas during 2005-‘06, the landings improved and reached the maximum of 129,801 t in 2008. The fishery was supported by nine species, five coastal/neritic species and four oceanic species. Coastal tunas formed 57% of the tuna catch during 2006-’10 and was represented by the little tuna (Euthynnus affinis), frigate tuna (Auxis thazard), bullet tuna (Auxis rochei), longtail tuna (Thunnus tonggol) and bonito (Sarda orientalis). The oceanic species, which formed 43% of tuna catch, were yellowfin tuna (Thunnus albacares), skipjack tuna (Katsuwonus pelamis), dogtooth tuna (Gymnosarda unicolor) and bigeye tuna (Thunnus obesus). Information collected from different sources suggested that longliners operating in Indian EEZ and adjacent international waters caught around 87,000 t of tuna annually during 2006-'10. Catch was supported by three species dominated by yellowfin tuna and small proportion of big-eye and dogtooth tuna. Since fishery by coastal based units restricted to small areas and share of the catch by longliners from EEZ are not clearly known, systematic assessment of tuna stock in Indian EEZ is very difficult. However, the evaluation of the fishery scenario indicated only limited scope for improving tuna production from certain areas of coastal waters; whereas enormous scope remain for increasing tuna production from the oceanic waters of EEZ. However, since tunas being straddling resources shared by several nations, exploitation at one area will influence the fishery in other areas

Massive Charged Scalar Quasinormal Modes of Reissner-N\"ordstrom Black Hole Surrounded by Quintessence

We evaluate the complex frequencies of the normal modes for the massive charged scalar field perturbations around a Reissner-N\"ordstrom black hole surrounded by a static and spherically symmetric quintessence using third order WKB approximation approach. Due to the presence of quintessence, quasinormal frequencies damp more slowly. We studied the variation of quasinormal frequencies with charge of the black bole, mass and charge of perturbating scalar field and the quintessential state parameter.Comment: 9 pages, 9 figures and one tabl

Fishery, biology and stock structure of skipjack tuna, Katsuwonus pelamis (Linnaeus, 1758) exploited from Indian waters

Global catches of skipjack tuna have been steadily increasing since 1951, reaching a peak in 2009 at 25, 99,681 t (Fig.1). Most of the catches were reported from the fishing areas 71, 51, 61 and 34 (FA0, 2011). Globally skipjack tuna is caught at the surface, mostly with purse seines and pole and lines and to a small extent by gillnets, troll lines and longlines. Gears like purse-seine and very long gillnets enabled few nations to augment their production, whereas traditional pole and line nations suffered heavily