Showing papers by "Sandip Mukhopadhyay published in 2016"
TL;DR: In this article, a biogeochemical cycling of CH4 was studied in Sundarbans mangrove system during June 2010 to December 2012, where the sediment was CH4 supersaturated with mean production potential of 3547 and 48.88 µmol m−3 d−1, respectively in case of intertidal (0-25 cm depth) and sub-tidal sediments (first 5 cm depth).
Abstract: . Biogeochemical cycling of CH4 was studied in Sundarbans mangrove system during June 2010 to December 2012. The sediment was CH4 supersaturated with mean production potential of 3547 and 48.88 µmol m−3 d−1, respectively in case of intertidal (0–25 cm depth) and sub-tidal sediments (first 5 cm depth). This induces significant CH4 out-flux from sediment to estuary via advective and diffusive transports. Mean advective (from intertidal sediment) and diffusive (from sub-tidal sediment) CH4 fluxes were 159.52 μmol m−2 d−1 and 8.45 μmol m−2 d−1, respectively. Intertidal sediment CH4 emission rate was about 4 times higher than surface layer CH4 oxidation rate; indicating petite methanotrophic activity in mangrove sediment. Mean CH4 concentration in estuarine surface and bottom waters were 69.90 and 56.17 nM, respectively. CH4 oxidation in estuarine water column being 14 times higher than water–atmosphere exchange is considered as principal CH4 removal mechanism in this estuary. Mean CH4 mixing ratio over the mangrove forest atmosphere was 2.013 ppmv. The ecosystem acts a source of CH4 to the upper atmosphere having mean biosphere–atmosphere exchange flux of 0.086 mg m−2 d−1. Mean CH4 photo-oxidation rate in the mangrove forest atmosphere was 3.25 × 10-9 mg cm−3 d−1 and is considered as principal CH4 removal mechanism in the forest atmosphere. Finally, a box model presenting CH4 biogeochemistry in Sundarbans biosphere reserve has been drafted and was used to demonstrate CH4 budget in this ecosystem.
3 citations
TL;DR: The species and varieties of Tabernaemontana have distinct total chromosome length, volume and nuclear DNA contents, and karyotype analysis showed differences in chromosome types and number of chromosome in each type.
Abstract: Tabernaemontana coronaria, a common garden plant in tropical countries, has been used as a traditional medicine. The beneficial properties of T. coronaria are antioxidant and anti-inflammatory. The active biocompounds including the alkaloids in the leaf extract enhance the cholinergic activity in both central and peripheral nervous system. A detailed analysis of morphological and cytological characters was carried out on three varieties and populations of T. coronaria and one population of T. dichotoma. Morphological characters like inter-node length, petiole length, leaf area and leaf index differed in species and varieties which may serve as identifying characters. Somatic chromosome analysis revealed 2n = 22 chromosomes in T. dichotoma, T. coronaria var. variegata, T. coronaria var. Dwarf, T. coronaria and 2n = 3X = 33 chromosomes in T. coronaria var. Flore-pleno with 2n = 3X = 33 being triploid. The species and varieties of Tabernaemontana have distinct total chromosome length, volume and nuclear DNA contents. Karyotype analysis showed differences in chromosome types and number of chromosome in each type. A conspicuous variation in chromosome characteristics was observed at intra specific and intra varietal level.
1 citations