13 research outputs found

    GIS Based Approach to Determine the Changes of Water Hyacinth (Eichhornia crassipes) Cover and Relation with Lesser Whistling Teal (Dendrocygna javanica) Assemblage at Santragachi Wetland, West Bengal

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    The present investigation is conducted to study the year wise (2011 to 2018) changes of water hyacinth (Eichhornia crassipes) cover at Santragachi Lake a Wetland under National Wetland Conservation Programme of India. Further the relationship between water hyacinth cover and the most abundant migratory waterbirds of Satragachi, Lesser Whistling Teal (LWT; Dendrocygna javanica) is assessed because this bird species is fully depended on water hyacinth mat for their roosting. The study comprises of eight satellite images procured from Google earth (2011 to 2018) to explore this relationship. A marked decline in the number of LWT at Santragachi wetland is observed in the year of 2017 and 2018. It is very interesting fact that from 2017-2018, the water hyacinth mat of this wetland is almost cleared before winter and the result of cluster analysis supports this fact. Significant positive correlation is also observed within LWT number and water hyacinth cover area (r = 0.7481 at p< 0.05) along with the total perimeter (r = 0.8648 at p< 0.05) of the water hyacinth islands at Santragachi wetland. However, open water area is also needed for diving, swimming, food searching for the LWT and other waterbirds. Therefore, more study is needed to optimize the clearing operations, focused on optimizing the shape and size of water hyacinth islands for proper management of the waterbirds habitat

    Sensitive and fluorescent Schiff base chemosensor for pico molar level fluoride detection: In vitro study and mimic of logic gate function

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    Modification of the side arm of two newly synthesized organic chemosensor acts as a ‘key’ for opening the ‘lock’ at pico molar level fluoride (F−) sensing by fluorescence ‘turn on’ phenomenon in different environmental water samples (drinking water) collected from rural parts of several districts of West Bengal, India. Intracellular fluoride detection in Candida albicans and pollens of Techoma stans, incubated in pico molar (10−12 M) fluoride contaminated hand pump water collected from Bankura, West Bengal has been successful under fluorescence microscope. The interesting fluorescence spectral responses mimics several different logic operations (XOR, OR, AND, NOT and NOR) with ‘Write-Read-Erase-Read’ option

    Community Structure of Migratory Waterbirds at Two Important Wintering Sites in a Sub-Himalayan Forest Tract in West Bengal, India

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    The waterbird community structures of two sub-Himalayan wetlands (Nararthali and Rasomati) situated in forested areas were compared during the wintering period. These wetlands had similar geophysical features but were subject to different conservation efforts. Sixty species of waterbirds, including four globally threatened species, were recorded during the study. Nararthali was found to be more densely inhabited (116.05±22.69 ind./ha) by birds than Rasomati (76.55±26.47 ind./ha). Density increased by 44.6% at Nararthali and by 59% at Rasomati over the years of the study, from 2008 to 2015. Winter visitors increased considerably at Nararthali (66.2%), while a 71.1% decrease at Rasomati clearly indicated degradation of habitat quality at that site during the later years. Luxuriant growth of Eichhornia crassipes, siltation, poor maintenance and unregulated tourist activities were the key factors leading to the rapid degradation of Rasomati. Nararthali, on the other hand, a well-managed wetland habitat, showed an increasing trend in bird densities. Therefore, poor habitat management and rapid habitat alterations were observed to be the main reasons for depletion of bird density in the wetlands of eastern sub-Himalayan forest regions

    Spatial variations in zooplankton diversity in waters contaminated with composite effluents

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    Zooplankton species are cosmopolitan in their clean freshwater habitat and are also found in industrial and municipal wastewaters. The present study records for the first time the aspects of zooplankton diversity in relation to physico-chemical environment of five selected sites of the East Calcutta wetlands, a Ramsar site of Kolkata city, India, heavily contaminated by industrial and municipal wastewaters. The study revealed the occurrence of 22 species of zooplankton, among these 3 species of Cladocera, 2 species of Copepoda, 15 species of Rotifera, and 2 species of Ostracoda were recorded. The copepod Mesocyclops leuckarti was found in all the five sites, rotifers Asplanchna brightwelli, Brachionus angularis, B. calyciflorus and Cladocera Ceriodaphnia cornuta were found in four sites; Moina micrura and Diaphanosoma sarsi were found at three sites. Site wise variation in dominance, diversity, evenness and richness were calculated. Site 1, a fish-pond that stabilized composite wastewater, showed the maximum species richness having 17 species, while Site 2, SWF wastewater carrying canal, showed only 4 species. The calculated Jack 1 values of Sites 1 to 5 were 21.78, 3.77, 18.63, 12.5 and 16.95 respectively. Shannon-Wiener species diversity index (H/) values were almost similar for all the three relatively less polluted sites viz, Site 1 (1.959), Site 4 (2.010), Site 5 (2.047). However, at highly polluted sites viz., 2 and 3, H/ value of 1.336 and 0.984 respectively, were calculated. Simpson’s Dominance index (Dsimp) value was highest at Site 3 (0.618) indicating maximum dominance, whereas at Site 5 dominance was lowest (0.1680) and diversity was highest. We discuss the role of zooplankton in the amelioration of wastewater

    Limnochemical Factors Influencing the Seasonal Population Density,Secondary Production, and Calcium-to-Tissue Ratio in the Freshwater Limpet Septaria lineata (Archaeogastropoda: Neritidae)

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    The distribution, secondary production, and calcium:tissue (Ca:tissue) ratio in relation to limno-chemical factors were studied in a freshwater limpet ( Septaria lineata) population from the west bank of the River Hooghly, West Bengal, India, for 2 successive years. Total hardness, chloride, pH, and phosphate were shown to be significant in Pearson’s correlations in influencing the abundance of the limpet population. Annual production for the 2 successive years was 10.3 gm2gm^{-2} and 9.5 gm2gm^{-2},respectively.The annual turnover ratios, the ratios of annual production (P) and annual standing crop (B), ‘P/B’, were calculated to be 2.06 and 1.67, while annual turnover times were 177 days and 219 days, respectively. The ratio of whole animal shell calcium content to tissue dry weight (shell Ca:tissue ratio)changed with age and size class, but these changes were largely restricted to early growth and did not significantly affect individuals over a particular size class (shell height 40-49 mm). Total hardness and chloride were the most important limnochemical factors influencing the shell Ca:tissue ratio

    Global association between thermophilicity and vancomycin susceptibility in bacteria

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    Exploration of the aquatic microbiota of several circum-neutral (6.0-8.5 pH) mid-temperature (55-85 OC) springs revealed rich diversities of phylogenetic relatives of mesophilic bacteria, which surpassed the diversity of the truly-thermophilic taxa. To gain insight into the potentially-thermophilic adaptations of the phylogenetic relatives of Gram-negative mesophilic bacteria detected in culture-independent investigations we attempted pure-culture isolation by supplementing the enrichment media with 50 µg ml-1 vancomycin. Surprisingly, this Gram-positive-specific antibiotic eliminated the entire culturable-diversity of chemoorganotrophic and sulfur-chemolithotrophic bacteria present in the tested hot water inocula. Moreover, it also killed all the Gram-negative hot-spring isolates that were obtained in vancomycin-free media. Concurrent literature search for the description of Gram-negative thermophilic bacteria revealed that at least 16 of them were reportedly vancomycin-susceptible. While these data suggested that vancomycin-susceptibility could be a global trait of thermophilic bacteria (irrespective of their taxonomy, biogeography and Gram-character), MALDI Mass Spectroscopy of the peptidoglycans of a few Gram-negative thermophilic bacteria revealed that tandem alanines were present in the fourth and fifth positions of their muropeptide precursors (MPPs). Subsequent phylogenetic analyses revealed a close affinity between the D-alanine-D-alanine ligases (Ddl) of taxonomically-diverse Gram-negative thermophiles and the thermostable Ddl protein of Thermotoga maritima, which is well-known for its high specificity for alanine over other amino acids. The Ddl tree further illustrated a divergence between the homologs of Gram-negative thermophiles and mesophiles, which broadly coincided with vancomycin-susceptibility and vancomycin-resistance respectively. It was thus hypothesized that thermophilic Ddls have been evolutionarily selected to favor a D-ala-D-ala bonding. However, preference for D-ala-D-ala-terminated MPPs does not guarantee vancomycin susceptibility of thermophilic bacteria as the large and relatively-hydrophilic vancomycin molecule has to cross the outer membrane before it can inhibit peptidoglycan biosynthesis. Literature shows that many mesophilic Gram-negative bacteria also have D-ala-D-ala-terminated MPPs, but they still remain resistant to vancomycin due to the relative impermeability of their membranes. But the global vancomycin-susceptibility phenotype of thermophilic bacteria itself testifies that the drug crosses the membrane in all these cases. As a corollary, it seems quite likely that the outer membranes of thermophilic bacteria have some yet-unknown characteristic feature(s) that invariably ensures the entry of vancomycin

    Abstracts of 1st International Conference on Machine Intelligence and System Sciences

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    This book contains the abstracts of the papers presented at the International Conference on Machine Intelligence and System Sciences (MISS-2021) Organized by the Techno College of Engineering, Agartala, Tripura, India &amp; Tongmyong University, Busan, South Korea, held on 1–2 November 2021. This conference was intended to enable researchers to build connections between different digital technologies based on Machine Intelligence, Image Processing, and the Internet of Things (IoT). Conference Title: 1st International Conference on Machine Intelligence and System SciencesConference Acronym: MISS-2021Conference Date: 1–2 November 2021Conference Location: Techno College of Engineering Agartala, Tripura(w), IndiaConference Organizer: Techno College of Engineering, Agartala, Tripura, India &amp; Tongmyong University, Busan, South Korea
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