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    ItemOpen Access
    Limnochemistry, diversity of plankton and ichthyofauna of some rivers of the Dooars region, West Bengal
    (University of North Bengal, 2022) Sarkar Tapan; Pal Joydeb
    The present study, entitled “Limnochemistry, diversity of plankton and ichthyofauna of some rivers of the Dooars region, West Bengal”, was conducted for a period of two years from March 2014 to February 2016. Three rivers, such as the Teesta, Jaldhaka, and Torsa, and two sites for each river, were selected for study. The study was conducted in three sections, such as physico-chemical parameters of river water, plankton diversity, and ichthyofaunal diversity. Temperature, pH, TS, TDS, TSS, DO, free CO2, chloride, TA, and TH were determined by standard methods. The Pearson’s correlation coefficient matrix, two-way ANOVA among seasons and sites, and one-way ANOVA between the two years were calculated using SPSS 16.0 and PAST 3.0 software. PCA was done by PAST 3.0 software. The air temperature, water temperature, depth of water, pH, dissolved oxygen, electrical conductivity, total dissolved solid, total suspended solid, total solid, total alkalinity, total hardness and chloride showed seasonal variation in the three investigated rivers. The water temperature, pH, TDS, TSS, TS, total alkalinity, total hardness, and chloride did not show any significant differences among the six sites of the three investigated rivers, but the depth of water, DO, and FC showed significant differences among the six sites. Water temperature is the most important parameter that controls other physico-chemical parameters of water. The pH, electrical conductivity, DO, TA, and TH of the three investigated rivers are within the optimum range, making them suitable for fish and other organisms. The DO and FC of the three investigated rivers indicate the good quality of water. Total alkalinity and total hardness indicate that the water of the three investigated rivers is soft in nature. The PCA concentrates variances of the original data of physico-chemical parameters into two principal components (PC1 and PC2) in the case of rivers Jaldhaka and Torsa and three principal components (PC1, PC2 and PC3) in the case of the river Teesta. PC1 represents more physical and less chemical, while PC2 represents more chemical and less physical. WT, TDS, TH, and TA are the most influential factors. A total of 24, 26, and 25 genera of phytoplankton belonging to five groups were recorded during the study period from the rivers Teesta, Jaldhaka, and Torsa, respectively. A total of 28 genera of phytoplankton were recorded from the three investigated rivers. Chlorophyceae was the most dominant group in all the three rivers. Phytoplankton density, numbers of phytoplankton genera, Shannon-Wiener diversity index, and Margalef’s species richness index are positively correlated with pH, TDS, conductivity, dissolved oxygen, total alkalinity, total hardness, and chloride but negatively correlated with air temperature, water temperature, depth of water, TSS, and free CO2. Similar relations have been suggested by PCA. A total of 17, 16, and 16 genera of zooplankton were obtained from the rivers Teesta, Jaldhaka, and Torsa, made up of protozoa, rotifera, cladocera, and copepoda. A total of 18 genera of zooplankton were recorded from the three investigated rivers. The density, number of genera, Shanon diversity index, and Margalef’s richness index of phytoplankton and zooplankton also showed seasonal variation in the three investigated rivers. The density and number of phytoplankton and zooplankton genera, Shannon-Wiener diversity index, and Margalef’s species richness index are positively correlated with pH, TDS, conductivity, dissolved oxygen, total alkalinity, total hardness, and chloride but inversely correlated with air temperature, water temperature, depth of water, TSS, free CO2. Similar relations have been suggested by PCA. The density, number of genera, diversity index, and Margalef’s species richness index of phytoplankton and zooplankton are positively influenced by PC2, meaning affected by the chemical properties of water such as DO, TDS, TA, TH, and CL. The number of genera, diversity index, and Margalef’s species richness index of phytoplankton and zooplankton are negatively influenced by PC1. They are also negatively affected by the physical properties of water such as water temperature, TSS, TS, and free carbon dioxide. PCA biplots confirmed that phytoplankton and zooplankton density and/or number were the most influential factors which influenced the diversity indices. A total of 147 fish species of ichthyoauna with remarkable variations in Teesta (140 species), Jaldhaka (119 species) and Torsa (131 species) were recorded. A total of 147 species belonging to 11 orders and 31 families were recorded over the study period from the three rivers. Out of 147 recorded species, 1 is Critically Endangered (0.68%), 20 (13.60%) are Endangered (EN) and 42 (28.57%) are Vulnerable (VU) (according to CAMP-NBFGR). But according to IUCN conservation status, 2 (1.36%) species are Endangered (EN) and 1 (0.68%) species is Vulnerable (VU). Out of 147 recorded species, 1 (0.68%) is Critically Endangered, 12 (8.16%) species are Endangered (EN), 23 (15.6%) species are Vulnerable (VU) and 33 (22.45%) species are near threatened (NT) (according to Barman). Of the total of fish species, only 10.20% (15 species) are endemic fish species recorded from the three rivers. Two endemic fish species are found only in North Bengal. CPUE, number of ichthyofauna genera, Shanon diversity index, and Margalef’s species richness index of ichthyofauna showed seasonal variation in the three investigated rivers. CPUE, density, Shannon-Wiener diversity index, and Margalef’s species richness index exhibited significant and positive correlation with air temperature, water temperature, depth of water, TSS, TS, and free carbon dioxide but a significant and negative correlation with TDS, dissolved oxygen, conductivity, total alkalinity, total hardness, and chloride. Similar relations have been suggested by PCA. CPUE, NF, and DVF are influenced by PC1, meaning more physical parameters such as water temperature and depth of water, but negatively influenced by DO, TDS, TA, TH, and CL. PCA biplots revealed that CPUE and the number of fish genera were the most influential factors that influenced diversity indices. Use of fine mesh size nets for fishing; river bed as an agricultural field; disposal of municipal waste; river embankment; presence of invasive fish species; mining of sand, gravel, and boulders from riverbed flood etc. are all threats to fish diversity.
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    ItemOpen Access
    Studies on antioxidant, antimicrobial and antidiabetic activities of some ethnomedicinal plants collected from Darjeeling Himalayan region, West Bengal
    (University of North Bengal, 2023) Das Vaskar; Ghosh Shilpi
    Since the dawn of human civilization, plants and plant-derived natural remedies have been a vital part of traditional healing. With advances in development of synthetic drug, their usage has dominated over natural products. However, with several examples of synthetic drug side effects in recent decades, there has been a huge increase in the hunt for natural and safer pharmaceuticals. Plants derived phytochemicals or bioactive substances are safer and more cost-effective resource for drug development. The rate of development of numerous devastating oxidative stress-related disorders such as cancer, diabetes, atherosclerosis, arthritis, Alzheimer's disease, and other neurological disorders has grown as people's lifestyles have changed. Plant phytochemicals have been described as effective free radical scavengers or quenchers, making them a rich source of natural antioxidants. Herbal medications have been utilized for antibacterial, antiviral, antiinflammatory, anti-rheumatid, antiallergic and other purposes. The use of ethnomedicinal herbs in traditional medicine dates back over 2000 years; and many more beneficial therapeutic metabolites are expected to be discovered during later years. Despite being abundantly available and offering economic, ecological and therapeutic values, ethnic plants have received very little attention. The aim of this study was to screen and quantify different phytochemicals present in specific ethnomedicinal plants of Darjeeling district, West Bengal, Pin 734101, in light of the importance of natural products and their application as pharmaceuticals. The plant extracts were investigated for antioxidant, antimicrobial, and antidiabetic activities. Further, the cone extract of Thuja orientalis was fractionated by column chromatography for the isolation of active compound followed by characterization of the compound as Octacosanol. The antidiabetic potential of the compound was evaluated in streptozotocin (STZ) induced rat model. A systematic review of the literature has been assembled to provide the details of previous studies on the several bioactive substances found in plants and their antioxidant, antimicrobial and antidiabetic potential. For present investigation Thuja orientalis (THU), Tupistra nutans (TUP), Astilbe rivularis (AST), Calamus erectus (CAL), Zanthoxylum oxyphyllum (ZAN) and Artemisia vulgaris (ART) were collected from various locations of Darjeeling district. The plant materials were shed dried, powdered and extracted with various solvents. With the different solvents utilized, a difference in extraction yield was noticed. The yield percent was least with hot water and ethanol, while methanolic extracts produced the highest percentage of yield and therefore used for further studies. The plant methanolic extracts were examined qualitatively and quantitatively for the presence of phytochemicals. Among various secondary metabolites phenol, flavonoid, tannin, carbohydrate and reducing sugar were found to be present in all the extracts. The quantitative analysis showed THU cones having the highest quantity of phenol, flavonoid, tannin and total carbohydrate whereas ART leaf exhibited all these phytochemicals in least quantity. The plant extracts showed different degrees of antioxidant activities as measured by DPPH radical, H2O2, NO and ABTS scavenging assays. AST rhizome exhibited maximum antioxidant activity in assay based on DPPH, NO and ABTS assay, whereas THU cone showed highest activity with H2O2. The antibacterial potential of the plant extracts was tested against two gram positive (Bacillus amyloliquefaciens and Bacillus subtilis) and two gram negative (Flexibacter sp. and Aeromonas liquefaciens) bacteria. While comparing antibacterial effect of various plant extracts, the THU cone exhibited highest antibacterial activity against Bacillus amyloliquefaciens, Bacillus subtilis and Aeromonas liquefaciens whereas AST rhizome showed highest activity against Flexibacter sp. The plant extracts were effective in limiting the growth of tested fungi, namely, Aspergillus niger, Rhizopus stolonifer, and Fusarium oxysporum, as measured by radial growth bioassay. The extracts of THU cone and THU leaf effectively suppressed radial growth of all of the fungi examined, but TUP flower and CAL fruit extracts only partially inhibited the radial growth. Depending upon phytochemical constituents, antioxidant and antimicrobial activity, THU cone was found to exhibit the highest possible avenue for profiting from their use in pharmaceuticals. Hence THU cone was used for isolation and purification of bioactive molecule followed by its characterization by UV, IR and NMR spectroscopy and LC-ESI-MS analysis. The active compound in THU cone was characterized as Octacosanol with molecular formula C28H56O and molecular weight of 408. Octacosanol was found to inhibit the in vitro α-amylase activity, and its inhibitory effect was about two fold lesser than that of the positive control acarbose. In an in vivo antidiabetic assay on streptozotocin-induced diabetic rats, Octacosanol was found to be effective in restoring various blood parameters that had been altered by the induction of diabetes. Variable parameters evaluated was change in body weights, fasting blood sugar level, cholesterol, triglycerides and HDL cholesterol content, SGPT and SGOT activities and serum urea and creatinine level. Higher concentration of compound revealed higher reduction in the tested blood parameters than the lower concentration used in the study. Treatment with Octacosanol significantly improved and restored the histological structure of both liver and pancreas in STZ-induced diabetes rat. The molecule Octacosanol has potential application in pharmaceuticals due to its hypoglycemic, antimicrobial and antioxidant effects
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    Effectiveness of digital marketing in attracting tourists in national parks of West Bengal : An empirical study
    (University of North Bengal, 2023) Saha, Mukesh; Bhattacharya, Debasis
    Tourist Satisfaction is one of the crucial aspects of any National park operator inviting mass tourists to their destinations. This study explores the website dimensions of National parks and tour operator websites and examines their effects on Tourists Satisfaction. For this study, the data has been collected from tourists who visited the National park through National park websites or tour operator websites. Convenience sampling has been used to select the places, and a total of 445 responses (369 are from tourists who visited through the National Park website and 76 are from tourists who visited through the tour operator website) have been collected using the snowball sampling method. The study considers demographic parameters such as age, gender, academic qualification, and income to analyse the demographic profile of the National park visitors. The study found that young adults (age groups between 26 and 40) are more inclined towards visiting National parks compared to other age groups. The study findings revealed that males are very keen to visit National parks compared to their female counterparts. Likewise, the study shows that National park visitors are well educated and have knowledge of the Internet and online booking. The National Park visitors fall under the upper middle-class income groups. Multiple regression analysis has been employed to examine the effects of the Website Usefulness (WU), Tangibility (TA), Website Friendliness (WF), and Reliability (REL). Design Quality (DQ) Information Quality (IQ) on Tourists Satisfaction(TS). The scale developed for the study has been adopted from previous literature and modified as per the needs of the study. The scales developed have been tested for reliability and validity, which are prerequisites for any scientific study. The reliability has been studied by employing Cronbach's alpha, which is a widely accepted measure for the reliability coefficient. This study reveals that the reliability values are quite acceptable in the sense that they are higher than the threshold level. To test the content and construct validity, a factor analysis is employed to examine the factor structure. The KMO values suggest that the fit of the model is adequate, as revealed by the Chi-Square value, which is significant beyond p<0.000. The constuct validity is established by the fact that the dimensions emerged quite distinct and there is no overlap among the various dimensions. The study's findings from data collected from tourists visiting the National Park website revealed that the Website Usefulness (WU). Tangibility (TA), Website Friendliness (WF). Reliability (REL), Design Quality (DQ) affect Tourists' Satisfaction (TS). The study has observed that the Website Usefulness (WU) of the National park website has a more substantial influence on Tourists' Satisfaction (due to the highest beta coefficient β = 0.377) followed by the other dimensions such as Tangibility (TA), Website Friendliness (WF), Reliability (REL), and Design Quality (DQ), based on their respective beta coefficients [(β=0.212, β=0.094, β=0.086, β=0.082)] on Tourist's Satisfaction (TS). However, Information Quality (IQ) does not influence the tourists satisfaction. Whereas findings of data collected from tourists visiting tour operators websites revealed that the Website Friendliness (WF), Website Usefulness (WU), Reliability (REL) affects Tourists Satisfaction (TS). The study has observed that the Website Friendliness (WF) has the greatest beta value (β = 0.334). compared to the other website aspects. Thus, the study revealed that the Website Friendliness (WF) aspect of National park websites has a more significant impact on Tourists Satisfaction (TS). The effects of National park website aspects including Website Usefulness (WU) and Reliability (REL) on Tourists Satisfaction are also found to be significant, with respective beta coefficients of 0.329, and 0.204. However, Tangibility (TA), Design Quality (DQ), and Information Quality (IQ) does not influence the Tourists Satisfaction. The findings of this study will help National park operators and tour operators understand the various dimensions of a National park website and tour operator's website. Moreover, the study's results will allow them to strategically focus on the relative importance of National park website and tour operator's website dimensions to satisfy tourists. The website media content providers will be able to know the various factors influencing tourists satisfaction, and they will develop their content so that it influences tourists satisfaction. Also, the findings of the study will enable operators of National parks and Tour operators to strategically concentrate on the relative significance of website dimensions to please tourists. This study provides a model for accessing tourists satisfaction based on the website dimensions of National parks and tour operators. However, this study has some limitations. The study considers only the West Bengal State National Park website and only seven website dimensions for the National Park and tour operator. Therefore, the study can be extended by an upcoming researcher by incorporating other National Park websites across the nation. In addition, other website dimensions of National Parks and tour operators can be accommodated to extend this research. The study findings will help National park managers understand the impact of various website dimensions on tourist satisfaction. In addition, this study provides useful information to tour operators to make their tourists satisfied. Key Words: Tourists Satisfaction (TS), Website Usefulness (WU), Tangibility (TA), Website Friendliness (WF), Reliability (REL), Design Quality (DQ), and Information Quality (IQ)
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    ItemOpen Access
    Women Legislators of West Bengal: A Study of Political Leadership Since 1990s
    (University of North Bengal, 2022-01) Roy, Aloka; Chakraborty, Ranjita
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    Enquiry into the causes and consequences of rural urban migration in West Bengal with special reference to Coochbehar District
    (University of North Bengal, 2022-11) Majumdar, Sujit; Bagchi, Kanak Kanti
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    Trends and patterns of agricultural hand use in Maldah district, West Bengal
    (University of North Bengal, 2022-11) Mandal, Tapash; Saha, Snehasish
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    Effects of terrain characteristics on land use land cover in sanka river basin (West Bengal and Jharkhand)
    (University of North Bengal, 2021) Biswas, Baidurya; Saha, Snehasish
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    Bank erosion and associated problems in upper mahananda basin in Darjeeling district, West Bengal
    (University of North Bengal, 2021) Sarkar, Pompi,; Mandal, D.K.
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    Search for molecular diversity of metallo-B-lactamase genes in eubacterial isolates of Karala and Mahananda rivers of West Bengal
    (University of North Bengal, 2021) Ranjan, Vivek Kumar; Chakraborty, Ranadhir