Environmental inventory and the distribution of inorganic nutrients in a tropical estuary of the south-west coast of India

Dissolved nutrients (PO sub(4)-P, NO sub(3)-N, NO sub(2)-N and SiO sub(4)-Si) estimated in the surface and bottom waters of five selected stations of the Paravur Lake, Kerala, India, during February 1987 to January 1988 revealed distinct seasonal variations. Rainfall and land drainage play significant roles in the nutrient economy, particularly NO sub(3)-N and SiO sub(4)-Si, of this water body. Abnormally high values of PO sub(4)-P indicated extremely polluted condition at the wetting zone of the lake during the premonsoon season. SiO sub(4)-Si showed significant negative relationship with salinity.

Effect of sublethal concentration of artificial seawater on oxygen uptake and opercular frequency in an Indian major carp, Labeo rohita (Ham.)

The present study reports the effect of artificial seawater on oxygen uptake and opercular frequency in an Indian major carp, Labeo rohita. Whereas a control fish of 7.34 g average body weight consumed 1.538 ml O sub(2.) hˉ¹, the 24h and 96h exposed fish of the same body weight consumed 1.07 4 and 0.897 ml O sub(2.) hˉ¹, respectively. The oxygen uptake per unit body weight under controlled condition was 0.219 ml. gˉ¹. hˉ¹, whereas in 24h and 96h exposed fish, it was 0.152 and 0.124 ml. gˉ¹, hˉ¹, respectively. The change in opercular movement in 24h exposed fish was 7.67% higher, whereas in 96h exposed fish, it was 22.43% higher as compared to the control one. All changes are highly significant (p<0.001).

Glycine uptake regulates hippocampal network activity via glycine receptor-mediated tonic inhibition

Functional glycine receptors (GlyRs) are enriched in the hippocampus, but their role in hippocampal function remains unclear. Since the concentration of ambient glycine is determined by the presence of powerful glycine transporter (GlyT), we blocked the r

An investigation of the kinetics of CO2 uptake by a synthetic calcium based sorbent

This study examines the kinetics of carbonation by CO2 at temperatures of ca. 750 °C of a synthetic sorbent composed of 15 wt% mayenite (Ca12Al14O33) and CaO, designated HA-85-850, and draws comparisons with the carbonation of a calcined limestone. In-situ XRD has verified the inertness of mayenite, which neither interacts with the active CaO nor does it significantly alter the CaO carbonation–calcination equilibrium. An overlapping grain model was developed to predict the rate and extent of carbonation of HA-85-850 and limestone. In the model, the initial microstructure of the sorbent was defined by a discretised grain size distribution, assuming spherical grains. The initial input to the model – the size distribution of grains – was a fitted parameter, which was in good agreement with measurements made with mercury porosimetry and by the analysis of SEM images of sectioned particles. It was found that the randomly overlapping spherical grain assumption offered great simplicity to the model, despite its approximation to the actual porous structure within a particle. The model was able to predict the performance of the materials well and, particularly, was able to account for changes in rate and extent of reaction as the structure evolved after various numbers of cycles of calcination and carbonation.

An investigation of the kinetics of CO 2 uptake by a synthetic calcium based sorbent

This study examines the kinetics of carbonation by CO 2 at temperatures of ca. 750°C of a synthetic sorbent composed of 15wt% mayenite (Ca 12Al 14O 33) and CaO, designated HA-85-850, and draws comparisons with the carbonation of a calcined limestone. In-situ XRD has verified the inertness of mayenite, which neither interacts with the active CaO nor does it significantly alter the CaO carbonation-calcination equilibrium. An overlapping grain model was developed to predict the rate and extent of carbonation of HA-85-850 and limestone. In the model, the initial microstructure of the sorbent was defined by a discretised grain size distribution, assuming spherical grains. The initial input to the model - the size distribution of grains - was a fitted parameter, which was in good agreement with measurements made with mercury porosimetry and by the analysis of SEM images of sectioned particles. It was found that the randomly overlapping spherical grain assumption offered great simplicity to the model, despite its approximation to the actual porous structure within a particle. The model was able to predict the performance of the materials well and, particularly, was able to account for changes in rate and extent of reaction as the structure evolved after various numbers of cycles of calcination and carbonation. © 2011 Elsevier Ltd.

Spectroscopic characterization of protein-wrapped single-wall carbon nanotubes and quantification of their cellular uptake in multiple cell generations

We study the spectral characteristics of bovine serum albumin (BSA) protein conjugated single-wall carbon nanotubes (SWNTs), and quantify their uptake by macrophages. The binding of BSA onto the SWNT surface is found to change the protein structure and to increase the doping of the nanotubes. The G-band Raman intensity follows a well-defined power law for SWNT concentrations of up to 33 μg ml-1 in aqueous solutions. Subsequently, in vitro experiments demonstrate that incubation of BSA-SWNT complexes with macrophages affects neither the cellular growth nor the cellular viability over multiple cell generations. Using wide spot Raman spectroscopy as a fast, non-destructive method for statistical quantification, we observe that macrophages effectively uptake BSA-SWNT complexes, with the average number of nanotubes internalized per cell remaining relatively constant over consecutive cell generations. The number of internalized SWNTs is found to be ∼30 × 106 SWNTs/cell for a 60 mm-2 seeding density and ∼100 × 10 6 SWNTs/cell for a 200 mm-2 seeding density. Our results show that BSA-functionalized SWNTs are an efficient molecular transport system with low cytotoxicity maintained over multiple cell generations. © 2013 IOP Publishing Ltd.

Water, salt water, and alkaline solution uptake in epoxy thin films

As a means of characterizing the diffusion parameters of fiber reinforced polymer (FRP) composites within a relatively short time frame, the potential use of short term tests on epoxy films to predict the long-term behavior is investigated. Reference is made to the literature to assess the effectiveness of Fickian and anomalous diffusion models to describe solution uptake in epoxies. The influence of differing exposure conditions on the diffusion in epoxies, in particular the effect of solution type and temperature, are explored. Experimental results, where the solution uptake in desiccated (D) or undesiccated (U) thin films of a commercially available epoxy matrix subjected to water (W), salt water (SW), or alkali concrete pore solution (CPS) at either 20 or 60°C, are also presented. It was found that the type of solution did not significantly influence the diffusion behavior at 20°C and that the mass uptake profile was anomalous. Exposure to 60°C accelerated the initial diffusion behavior and appeared to raise the level of saturation. In spite of the accelerated approach, conclusive values of uptake at saturation remained elusive even at an exposure period of 5 years. This finding questions the viability of using short-term thin film results to predict the long-term mechanical performance of FRP materials. © 2013 Wiley Periodicals, Inc.

Allelopathic interactions between the Potamogeton spp and toxic cyanobacteria (Microcystis aeruginosa)

This study aimed to investigate the allelopathic activities between 3 Potamogeton spp. (Potamogeton maackianus, Potamogeton malaianus and Potamogeton pectinatus) and the toxic cyanobacteria (Microcystis aeruginosa). All Potamogeton spp inhibited the growth of M. aeruginosa in both coexistence and exudates experiments. Inhibition of M. aeruginosa growth by plant exudates depended strongly on the biomass of P malaianus. Initial pH (6.5-9.8) did not influence the inhibitory effects of P. malaianus exudates. However, the M. aeruginosa inhibited the net photosynthesis and respiration of all three pondweed test spp.. The decreases in photosynthesis and respiration were probably caused by the toxic compounds released by M. aeruginosa, rather than its shading effects. The M. aeruginosa also decreased the nutrients (phosphorus and nitrogen) uptake rates of macrophytes. The absorption rates of phosphorus and nitrogen and net photosynthesis were decreased sharply. These results will help to restore submerged plants in eutrophic waters.

Molecular cloning and expression characterization of ApoC-I in the orange-spotted grouper

Endogenous yolk nutrients are crucial for embryo and larval development in fish, but developmental behavior of the genes that control yolk utilization remains unknown. Apolipoproteins have been shown to play important roles in lipid transport and uptake through the circulation system. In this study, EcApoC-I, the first cloned ApoC-I in teleosts, has been screened from pituitary cDNA library of female orange-spotted grouper (Epinephelus coioides), and the deduced amino acid sequence shows 43.5% identity to one zebrafish (Danio rerio) hypothetical protein similar to ApoC-I, and 21.2%, 21.7%, 22.5%, 20%, and 22.5% identities to Apo C-I of human (Homo sapiens), house mouse (Mus musculus), common tree shrew (Tupaia glis), dog (Canis lupus familiaris) and hamadryas baboon (Papio hamadryas), respectively. Although the sequence identity is low, amphipathic alpha-helices with the potential to bind to lipid were predicted to exist in the EcApoC-I. RT-PCR analysis revealed that it was first transcribed in gastrula embryos and maintained a relatively stable expression level during the following embryogenesis. During embryonic and early larval development, a very high level of EcApoC-I expression was in the yolk syncytial layer, indicating that it plays a significant role in yolk degradation and transfers nutrition to the embryo and early larva. By the day 7 after hatching, EcApoC-I transcripts were observed in brain. In adult, EcApoC-I mRNA was detected abundantly in brain and gonad. In transitional gonads, the EcApoC-I expression is restricted to the germ cells. The data suggested that EcApoC-I might play an important role in brain and gonad morphogenesis and growth.