60 results on '"Saha GK"'
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2. A Prospective Comparison of Octyl-2-Cyanoacrylate and Suture in Facial Wounds.
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Saxena A, Dubey M, Saha GK, Tiwari D, Tyagi S, and Singh RA
- Abstract
The study aimed to evaluate the efficacy of octyl-2-cyanoacrylate as well as sutures as a wound closure material. Whether octyl-2-cyanoacrylate can be used as an alternative to suture in the closure of facial wounds. Out of total of 19 wounds, 11 wounds were closed with sutures and tissue adhesive both, out of rest 8 wounds, 4 wounds were closed using sutures alone and in 4 wounds, closure was done with tissue adhesive alone. Therefore, a total of 15 facial wounds were divided into two groups: Group-I Cases in whom 3-0 Black silk suture was used for closure of the wound and Group-II Cases in whom Dermabond (Octyl-2-Cyanoacrylate) was used for closure of the wound. Results showed that Octyl-2-cyanoacrylate offered the benefit of decreased procedure time with less pain, no need for its removal, and better cosmetic outcome compared to sutures., Competing Interests: There are no conflicts of interest., (Copyright: © 2023 Journal of Pharmacy and Bioallied Sciences.)
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- 2023
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3. A deep learning-based novel approach to generate continuous daily stream nitrate concentration for nitrate data-sparse watersheds.
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Saha GK, Rahmani F, Shen C, Li L, and Cibin R
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High-frequency stream nitrate concentration provides critical insights into nutrient dynamics and can help to improve the effectiveness of management decisions to maintain a sustainable ecosystem. However, nitrate monitoring is conventionally conducted through lab analysis using in situ water samples and is typically at coarse temporal resolution. In the last decade, many agencies started collecting high-frequency (5-60 min intervals) nitrate data using optical sensors. The hypothesis of the study is that the data-driven models can learn the trend and temporal variability in nitrate concentration from high-frequency sensor-based nitrate data in the region and generate continuous nitrate data for unavailable data periods and data-limited locations. A Long Short-Term Memory (LSTM) model-based framework was developed to estimate continuous daily stream nitrate for dozens of gauge locations in Iowa, USA. The promising results supported the hypothesis; the LSTM model demonstrated median test-period Nash-Sutcliffe efficiency (NSE) = 0.75 and RMSE = 1.53 mg/L for estimating continuous daily nitrate concentration in 42 sites, which are unprecedented performance levels. Twenty-one sites (50 % of all sites) and thirty-four sites (76 % of all sites) demonstrated NSE > 0.75 and 0.50, respectively. The average nitrate concentration of neighboring sites was identified as a crucial determinant of continuous daily nitrate concentration. Seasonal model performance evaluation showed that the model performed effectively in the summer and fall seasons. About 26 sites showed correlations >0.60 between estimated nitrate concentration and discharge. The concentration-discharge (c-Q) relationship analysis showed that the study watersheds had four dominant nitrate transport patterns from landscapes to streams with increasing discharge, including the flushing pattern being the most dominant one. Stream nitrate estimation impedes due to data inadequacy. The modeling framework can be used to generate temporally continuous nitrate at nitrate data-limited regions with a nearby sensor-based nitrate gauge. Watershed planners and policymakers could utilize the continuous nitrate data to gain more information on the regional nitrate status and design conservation practices accordingly., Competing Interests: Declaration of competing interest The authors declare that they have no known competing financial interests or personal relationships that could have appeared to influence the work reported in this paper., (Copyright © 2023 Elsevier B.V. All rights reserved.)
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- 2023
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4. Evaluating water quality benefits of manureshed management in the Susquehanna River Basin.
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Saha A, Saha GK, Cibin R, Spiegal S, Kleinman PJA, Veith TL, White CM, Drohan PJ, and Tsegaye T
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- Animals, Manure, Soil, Phosphorus analysis, Nitrogen analysis, Livestock, Agriculture, Water Quality, Rivers
- Abstract
Manureshed management guides the sustainable use of manure resources by matching areas of crop demand (nutrient sinks) with areas generating livestock manure (nutrient sources). A better understanding of the impacts of manureshed management on water quality within sensitive watersheds is needed. We quantified the potential water quality benefits of manureshed-oriented management through scenario-based analyses in the Susquehanna River Basin (SRB) using the Soil and Water Assessment Tool. Five manureshed management scenarios were developed and compared with a baseline "business-as-usual" scenario. The baseline assumes manure is less transportable, which means some locations have manure application in excess of crop demand. The "watershed nutrient balance" scenarios assume excess manure from surplus locations is transportable and that manure is applied around the SRB based on crop nutrient demand. The "watershed nutrient balance avoiding runoff prone areas" scenarios assume manure is transportable but not applied in vulnerable landscapes of the SRB. Each scenario was evaluated under two application rates considering crop nitrogen demand (N-based) and phosphorus demand (P-based). Phosphorus-based manureshed management was more effective in water quality improvements than N-based management. Phosphorus-based nutrient balance scenarios simulated 3 and 25% reduction in total N (TN) and total P (TP), respectively, from the baseline scenario at the watershed outlet. The N- and P-based scenarios avoiding runoff prone areas simulated 3 and 6% reduction in TN loss and 4 and 25.2% reduction in TP loss, respectively, from the baseline. Overall, the manureshed management scenarios were more effective in improving the quality of local streams in livestock-intensive regions than at the watershed outlet., (© 2022 The Authors. Journal of Environmental Quality © 2022 American Society of Agronomy, Crop Science Society of America, and Soil Science Society of America.)
- Published
- 2023
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5. Macroinvertebrates as engineers for bioturbation in freshwater ecosystem.
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Chakraborty A, Saha GK, and Aditya G
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- Ecosystem, Fresh Water, Geologic Sediments chemistry, Water, Environmental Pollutants, Metals, Heavy
- Abstract
Bioturbation is recognized as a deterministic process that sustains the physicochemical properties of the freshwater ecosystem. Irrigation, ventilation, and particle reworking activities made by biotic components on sediment beds influence the flow of nutrients and transport of particles in the sediment-water interface. Thus, the biogenic disturbances in sediment are acknowledged as pivotal mechanism nutrient cycling in the aquatic system. The macroinvertebrates of diverse taxonomic identity qualify as potent bioturbators due to their abundance and activities in the freshwater. Of particular relevance are the bioturbation activities by the sediment-dwelling biota, which introduce changes in both sediment and water profile. Multiple outcomes of the macroinvertebrate-mediated bioturbation are recognized in the form of modified sediment architecture, changed redox potential in the sediment-water interface, and elicited nutrient fluxes. The physical movement and physiological activities of benthic macroinvertebrates influence organic deposition in sediment and remobilize sediment-bound pollutants and heavy metals, as well as community composition of microbes. As ecosystem engineers, the benthic macroinvertebrates execute multiple functional roles through bioturbation that facilitate maintaining the freshwater as self-sustaining and self-stabilizing system. The likely consequences of bioturbation on the freshwater ecosystems facilitated by various macroinvertebrates - the ecosystem engineers. Among the macroinvertebrates, varied species of molluscs, insects, and annelids are the key facilitators for the movement of the nutrients and shaping of the sediment of the freshwater ecosystem., (© 2022. The Author(s), under exclusive licence to Springer-Verlag GmbH Germany, part of Springer Nature.)
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- 2022
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6. Influence of habitat complexity on the prey mortality in IGP system involving insect predators (Heteroptera) and prey (Diptera): Implications in biological control.
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Brahma S, Sharma D, Banerjee S, Saha GK, and Aditya G
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- Animals, Ecosystem, Food Chain, Larva physiology, Predatory Behavior physiology, Culicidae, Heteroptera
- Abstract
Intraguild predation (IGP) is common in the freshwater insect communities, involving a top predator, intraguild prey (IG prey) and a shared prey. Influence of the habitat complexity on the prey-predator interactions is well established through several studies. In the present instance, the IGP involving the heteropteran predators and the dipteran prey were assessed in the background of the habitat complexity. The three predators Diplonychus rusticus, Ranatra filiformis, and Laccotrephes griseus, one intraguild prey Anisops bouvieri and two dipteran prey Culex quinquefasciatus and Chironomus sp. were used in different relative density against the complex habitat conditions to deduce the impact on the mortality on the prey. In comparison to the open conditions, the presence of the macrophytes and pebbles reduced the mortality of the shared prey under intraguild system as well as single predator system. The mortality of the shared prey was however dependent on the density of the predator and prey. Considering the shared prey mortality, predation on mosquito larvae was always higher in single predator system than chironomid larvae irrespective of identity and density of predators. However, for both the shared prey, complexity of habitat reduced the prey vulnerability in comparison to the simple habitat condition. Higher observed prey consumption depicts the higher risk to predation of shared prey, though the values varied with habitat conditions. Mortality of IG prey (A. bouvieri) in IGP system followed the opposite trend of the shared prey. The lower mortality in simple habitat and higher mortality in complex habitat conditions was observed for the IG prey, irrespective of shared prey and predator density. In IGP system, the shared prey mortality was influenced by the habitat conditions, with more complex habitat reducing the vulnerability of the shared prey and increased mortality of the IG prey. This implies that the regulation of the mosquitoes, in the IGP system will be impeded by the habitat conditions, with the heteropteran predators as the top predator., Competing Interests: The authors have declared that no competing interests exist.
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- 2022
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7. Spread and Endemicity of Cholera in India: Factors Beyond the Numbers.
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Saha GK and Ganguly NK
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- Cholera transmission, Cholera Vaccines, Disease Outbreaks, Humans, India epidemiology, Population Surveillance, Public Health, Cholera epidemiology, Cholera prevention & control, Endemic Diseases, Vaccination
- Abstract
Cholera outbreaks currently account for 1.3 to 4.0 million cases and cause between 21 000 and 143 000 deaths worldwide. Cholera is preventable by proper sanitization and immunization; however, in many developing nations such as India, cholera disease is endemic. The surveillance system in India does not adequately capture the actual number of cases. As a result, it is important to utilize limited public health resources correctly in India and other developing counties more effectively to reach vulnerable communities. In this study, we analyze how studies make sense of cholera transmission and spread in India from 1996 to 2015. Furthermore, we analyze how a more sensitive surveillance system can contribute to cholera eradication by giving rise to outbreak preparedness., (© The Author(s) 2021. Published by Oxford University Press for the Infectious Diseases Society of America.)
- Published
- 2021
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8. Association of HLA-DQ and IL13 gene variants with challenge-proven shrimp allergy in West Bengal, India.
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Laha A, Ghosh A, Moitra S, Biswas H, Saha NC, Bhattacharya S, Saha GK, and Podder S
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- Administration, Oral, Adult, Aged, Animals, Case-Control Studies, Female, Follow-Up Studies, Genetic Predisposition to Disease, Genome-Wide Association Study, Genotype, Haplotypes, Humans, Immunoglobulin E immunology, India epidemiology, Male, Middle Aged, Prognosis, Shellfish Hypersensitivity epidemiology, Shellfish Hypersensitivity genetics, Young Adult, HLA-DQ Antigens genetics, Immunoglobulin E blood, Interleukin-13 genetics, Penaeidae immunology, Polymorphism, Single Nucleotide, Shellfish Hypersensitivity immunology
- Abstract
Little is known about genetic factors and mechanisms underlying shrimp allergy. Genome-wide association studies identified HLA class-II and IL13 genes as highly plausible candidates for shrimp allergy. The present study was designed to investigate potential associations of HLA-DQ rs9275596, IL13 rs20541, and IL13 rs1800925 polymorphisms with challenge-proven shrimp allergy using the data from 532 people of West Bengal, India; selected on basis of positive skin prick test, elevated specific IgE and medical history. Risk genotypes, i.e., HLA-DQ rs9275596 CC, IL13 rs20541 AA, and IL13 rs1800925 TT, were found to be significantly associated with challenge positive shrimp allergy (P = 0.04, 0.01, and 0.03, respectively). Distribution of genotypes for HLA-DQ and IL13 polymorphisms in allergic and control subjects showed significant difference between younger (20-40 years) and older (> 40 years) age group (P = 0.006). Risk genotypes significantly associated with elevated shrimp-specific IgE. IL13 TA haplotype significantly associated with shrimp allergy and elevated specific IgE (P = 0.02). Synergistic effect of IL13 TA haplotype-HLA-DQ rs9275596 CC genotype interaction significantly elevated specific IgE (P = 0.03). The present study suggests that HLA-DQ and IL13 polymorphisms pose major risk for shrimp allergic patients in West Bengal, India and thus could be helpful for early target-specific therapeutic intervention in near future.
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- 2020
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9. Phytochemical analysis of mite-infested tea leaves of Darjeeling Hills, India.
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Banerjee P, Islam MM, Laha A, Biswas H, Saha NC, Saha GK, Sarkar D, Bhattacharya S, and Podder S
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- Animals, India, Phytochemicals, Plant Leaves, Tea, Mites
- Abstract
Introduction: Darjeeling tea of India is one of the most famous beverages globally. However, a large amount of tea crop is damaged every year by the attack of mites., Objectives: The study aimed to determine the changes in different pigments and biochemical components of tea leaves due to mite infestation., Materials and Methods: We used UV-visible and Fourier-transform infrared (FTIR) spectroscopy simultaneously to understand the damages in pigment contents of the leaves of tea (Camellia sinensis (L.) Kuntze) due to attack of phytophagus mite, Oligonychus coffeae Nietner. Furthermore, chemical analysis of infested tea leaves was also performed to compare the nutrients of the plants, namely total phenol, protein and soluble sugar., Results: The UV-visible study reveals severe reduction of the pigments such as chlorophyll (Chl), carotenoids and xanthophylls in the tea leaf due to mite infestation. The findings of the FTIR study, also shows variation in different physiochemical components in the leaf Chl. The sugar and protein content of the infested leaves have been reduced compared to uninfested ones. Results in the case of tea leaves plucked during first (March) and third (November) flushes show similar trends., Conclusion: The increase in phenolic and alcoholic components and decrease in Chl contents may affect the quality of Darjeeling tea. The extent of damages done by the pests measured here could aid the pest management in tea gardens., (© 2019 John Wiley & Sons, Ltd.)
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- 2020
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10. Past, Present and Future: Combining habitat suitability and future landcover simulation for long-term conservation management of Indian rhino.
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Mukherjee T, Sharma LK, Saha GK, Thakur M, and Chandra K
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- Animals, Ecosystem, Forests, Grassland, India, Logistic Models, Nepal, Neural Networks, Computer, Conservation of Natural Resources methods, Perissodactyla growth & development
- Abstract
The Indian rhino (Rhinoceros unicornis) is susceptible to habitat change and fragmentation due to illegal logging, rapid urbanization and non-forest use and therefore were confined in to isolated areas throughout its distribution. The present study was conducted in Gorumara landscape which is composed of two protected areas (PAs) viz., Gorumara National Park (GNP) and Chapramari Wildlife Sanctuary. Both PAs were separated by a territorial forest range (Bridge Area), which is between both the PAs and under high anthropogenic disturbance. The study was designed to understand the impacts of landcover change on habitat suitability of R. unicornis in a multi-temporal scenario from 1998 to 2018 using ensemble approach and also to simulate the future habitat suitability for 2028. Our result suggests a significant increase in woodland cover inside the PAs, whereas the grassland cover has increased outside the PA in territorial range. We found a strong positive association of R. unicornis with grasslands. The Comparison of the future suitability model of 2028 with that of 2018 indicates a substantial increase in rhino suitable area by 13% in the territorial forest. Hence, bringing the territorial forest into the PA network, will be a crucial step to increase the fodder availability and better connectivity for the long term survival of the species.
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- 2020
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11. Assessment of Hymenoptera and Non-Hymenoptera Insect Bite and Sting Allergy Among Patients of Tropical Region of West Bengal, India.
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Laha A, Sarkar T, Dey D, Mondal P, Bhattacharya S, Moitra S, Saha GK, and Podder S
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- Adolescent, Adult, Age Factors, Animals, Child, Female, Humans, Hypersensitivity etiology, Incidence, India epidemiology, Male, Middle Aged, Sex Factors, Young Adult, Allergens adverse effects, Diptera, Grasshoppers, Hymenoptera, Hypersensitivity epidemiology, Insect Bites and Stings complications, Periplaneta
- Abstract
West Bengal, India, is inhabited by abundance and variety of insects that triggers sensitization in some humans to inhalant allergens and/or insect stings/venoms. Lack of research on this topic prevented accurate diagnosis and proper follow-up treatments to patients suffering from insect-induced allergies. The aim of our study was to identify the allergy-causing insects and evaluate resulting sensitization among a study population in West Bengal, India. The skin prick test (SPT) evaluated sensitivity of 450 patients who sought treatment at the Allergy and Asthma Research Center from July 2017 to June 2018. Eight insect allergens were tested: Common Black Ant (Lasius niger, Linnaeus 1758), Fire Ant (Solenopsis invicta, Buren 1972), Honey Bee (Apis cerana indica, Fabricius 1798), Common Wasp (Vespula vulgaris, Linnaeus 1758), Mosquito (Aedes aegypti, Linnaeus in Hasselquist 1762), American Cockroach (Periplaneta americana, Linnaeus 1758), House Fly (Musca domestica, Linnaeus 1758), and Grasshopper (Gesonula punctifrons, Stal 1861). From a total of 450 patients evaluated, 370 patients had positive SPT reaction from at least one of the 8 insect allergens tested. Sensitivity to some Hymenoptera insects (common black ant, 87.62%; fire ant, 84.59%; and honey bee, 67.02%) was found in higher proportion than non-Hymenoptera group (mosquito, 66.67%; American cockroach, 33.33%; house fly, 10.41%; and grasshopper, 5.14%). There was significant difference in sensitivity among child, adolescent, and adult (P < 0.001). While female patients showed more sensitivity than males to SPT, the difference was statistically insignificant. In regards to occupation, farmers and bee keepers were most sensitive of field workers sensitive to Hymenoptera-derived allergens., (© The Author(s) 2019. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2020
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12. Changing landscape configuration demands ecological planning: Retrospect and prospect for megaherbivores of North Bengal.
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Mukherjee T, Sharma LK, Thakur M, Saha GK, and Chandra K
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- Animals, Cattle, Elephants, Environmental Monitoring, India, Conservation of Natural Resources methods, Grassland, Herbivory, Parks, Recreational
- Abstract
The Gorumara National Park (GNP) is an important conservation area located in the northern region of West Bengal State, India, as it provides habitat for three megaherbivores: Indian One-horned rhinoceros (Rhinoceros unicornis), Asian elephants (Elephas maximus) and Gaurs (Bos gaurus). It harbours one of the last population of the one-horned rhino. In the present study, landscape change and configuration were investigated by comparing three Landsat images, from 1998, 2008 and 2018. The images were classified into six different landcover classes following standard methodology. The present study also involves evaluation of landscape and anthropogenic predictors influence on the megaherbivores of GNP, followed by future landcover simulation for the year 2028. The result shows a significant decrease in the grassland cover from 18.87 km2 to 8.27 km2 from 1998 to 2018, whereas the woodland cover has increased from 50.14 km2 to 62.09 km2 between 1998 and 2018. The landscape configuration indices such as Number of Patches (NP), Patch Density (PD), Interspersion and Juxtaposition (IJI), Aggregation Index (AI) and Mean Shape Index (SHAPE AM) indicated that the landscapes has lost complexity in the spatial placement of patches of different Land Use and Land Cover (LULC) classes. Also, the landscape over the three decades has become uniform in terms of diversity of patches, because of earlier plantation activities by the forest managers. Result also indicated that grassland, along with its class metrics are the top predictors contributing 43.6% in explaining the spatial distribution of megaherbivores in GNP. Results from the simulated landcover of 2028 suggest a possible decline in overall grassland by 6.23% and a subsequent upsurge in woodland by 6.09% from 2018. The present result will be useful in guiding the forest management in developing habitat improvement strategies for the long- term viability of megaherbivore populations of rhino, gaur and elephant in the GNP., Competing Interests: The authors have declared that no competing interests exist.
- Published
- 2019
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13. Investigation of house dust mite induced allergy using logistic regression in West Bengal, India.
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Mondal P, Dey D, Chandra Saha N, Moitra S, Saha GK, Bhattacharya S, and Podder S
- Abstract
Background: The diagnosis of house dust mite (HDM) allergy based on Skin prick test (SPT) is not accurate, especially in lower risk cases. Our aim is to develop and validate a predictive model to diagnose the HDM allergic symptoms (urticaria, allergic rhinitis, asthma)., Methods: A forward-step logistic regression model was developed using a data set of 537 patients of West Bengal, India consisting of clinical variables (SPT based on 6 allergens of house dust and house dust mites, total IgE) and demographic characteristics (age, sex, house conditions). The output probability was estimated from the allergic symptoms shown by the patients. We finally prospectively validated a data set of 600 patients., Results: The gradual inclusion of the variables increased the correlation between observed and predicted probabilities (correlation coefficient (r
2 ) = 0.97). The model development using group-1 showed an accuracy rate of 99%, sensitivity and specificity of 99.7% and 88.6% respectively and the area under the receiver operating characteristics (ROC) curve (AUC) of 99%. The corresponding numbers for the validation of our model with group-2 were 87%, 95.6% and 66% and 86% respectively. The model predicted the probability of symptoms better than SPTs in combination (accuracy rate 0.76-0.80), especially in lower risk cases (probability< 0.8) that are highly difficult to diagnose., Conclusion: This is perhaps the first attempt to model the outcome of HDM allergy in terms of symptoms, which could open up an alternative but highly efficient way for accurate diagnosis of HDM allergy enhancing the efficiency of immunotherapy., (© 2019 The Authors. Published by Elsevier Inc. on behalf of World Allergy Organization.)- Published
- 2019
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14. A review of house dust mite allergy in India.
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Dey D, Saha GK, and Podder S
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- Animals, Humans, India, Antigens, Dermatophagoides immunology, Pyroglyphidae immunology
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House dust mites (HDMs) are extensively reported as potent allergens worldwide with India being in the top row. HDM sensitization is hugely reported from India and has led to the concern of implementing proper guidelines for treatment of the sufferers. Climatic conditions and a rapid shift of life style toward a more indoor and urbanised pattern are denoted as the probable causes of increased HDM exposure and sensitization. On the contrary, the varying rate of HDM allergy from similar climate and urbanised areas throughout the world suggest the influence of genetic predisposition. At present, in India, avoidance of HDM exposure is recommended as the baseline defence. Allergen immunotherapy (AIT) guidelines are proposed in India to maintain uniformity in the diagnosis techniques and management strategies throughout the country. Considering the genetic susceptibility toward allergic diseases, the concept of 'personalised medicine' is preferred over the 'mass targeted treatment'. From the Indian perspective, the present problem is Dermatophagoides pteronyssinus and D. farinae allergens are not well characterised at the molecular level. As a consequence, India is still reliant on less standardised allergen extracts. The proper identification, purification, and molecular characterization of HDM allergens can combat this problem. In this review, we aimed to portray a complete account of HDM allergy in India with respect to prevalence, probable triggers, diagnosis and therapy. We have attempted to present the current ambiguities along with the likely deciphering that would pave the way to solve HDM allergy-related queries in India.
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- 2019
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15. Evaluation of Sensitivity Toward Storage Mites and House Dust Mites Among Nasobronchial Allergic Patients of Kolkata, India.
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Mondal P, Dey D, Sarkar T, Laha A, Moitra S, Bhattacharyya S, Saha NC, Saha GK, and Podder S
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- Adolescent, Adult, Animals, Female, Humans, Immunoglobulin E blood, India epidemiology, Male, Respiratory Hypersensitivity blood, Respiratory Hypersensitivity epidemiology, Young Adult, Acaridae immunology, Pyroglyphidae immunology, Respiratory Hypersensitivity etiology
- Abstract
House dust mites (HDMs) are the major constituents of house dust (HD). HD and HDM sensitization is well documented worldwide. Storage mite (SM) sensitization is presently lacking from India. The present study evaluated the sensitization of both HDM and SM among 372 allergic rhinitis patients reported to the Allergy and Asthma Research Center of Kolkata metropolitan, India. HD samples were collected from the patients' home and analyzed for the major constituent mites. HD and six constituent mites Dermatophagoides pteronyssinus (DP), Dermatophagoides farina Hughes (Acari: Pyroglyphidae) (DF), Blomia tropicalis (BT), Acarus siro Linnaeus (Acari: Acaridae) (AS), Lepidoglyphus destructor (LD), and Tyrophagus putrescentiae (Schrank) (Acari: Acaridae) (TP) are tested for the allergenic potential through Skin Prick Test (SPT). Three SMs, namely AS, LD, and TP, were newly included in the mite SPT extract for the first time in Kolkata. In total, 330 patients showed significant positive SPT toward any one allergen tested. HD was the major elicitor exhibiting 92.42% response. Individuals of age group 15-40 were the worst sufferers. DF showed the highest sensitization (87.87%) among the dust mites. The SMs also contributed significantly to prove their sensitizing potential. SPT rates for AS, LD, and TP were 33, 25, and 18%, respectively. SPT grades and total Immunoglobulin E (IgE) were positively correlated for each of the allergens. Most of the patients were multi-sensitized (95%) and represented markedly high total IgE levels (>500 IU/ml). Three SMs proved to be significant allergens for the studied population. The sensitization toward these SMs is first time reported from India and can be recommended for inclusion of routine SPT for better outcome in the future., (© The Author(s) 2018. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2019
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16. Can India lead the way in neglected diseases innovation?
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Thomas Z, Saha GK, Gopakumar KM, and Ganguly NK
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- Diffusion of Innovation, Drug Approval legislation & jurisprudence, Drug Development legislation & jurisprudence, Health Policy, Humans, India, Translational Research, Biomedical, Biomedical Research economics, Neglected Diseases diagnosis, Neglected Diseases drug therapy
- Abstract
Competing Interests: Competing interests: We have read and understood BMJ policy on declaration of interests and have no relevant interests to declare.
- Published
- 2019
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17. Sensitization to Common Aeroallergens in the Atopic Population of West Bengal, India: An Investigation by Skin Prick Test.
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Dey D, Mondal P, Laha A, Sarkar T, Moitra S, Bhattacharyya S, Saha GK, and Podder S
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- Adolescent, Adult, Animals, Child, Child, Preschool, Environmental Exposure, Female, Humans, Hypersensitivity, Immediate diagnosis, India epidemiology, Male, Population Surveillance, Skin Tests, Young Adult, Aerosols, Allergens immunology, Hypersensitivity, Immediate epidemiology, Hypersensitivity, Immediate immunology, Immunization
- Abstract
Background: Aeroallergen sensitization is increasing worldwide. The optimal management of allergic disease requires the identification of the allergic sensitivities of the patient. Complete data of offending aeroallergens are scant from West Bengal, India. Hence, we employed a retrospective analysis of an atopic population of West Bengal to investigate the rate of sensitivity toward common aeroallergens including pollens, molds and house dust mites., Objectives: The aim of the present study was to evaluate the profile of skin prick test (SPT) reactivity of an atopic population of eastern India., Methods: The prevalence aeroallergen sensitization was investigated by SPT along with a questionnaire survey of patients who visited the Allergy and Asthma Research Center of West Bengal, India, from June 2016 to May 2018. Patients were categorized according to the demographic (age, gender) and clinical aspects. Statistical tests were applied to differentiate between age and gender of the sufferers., Results: 524 out of 605 patients exhibited a positive SPT response toward one or more aeroallergens tested. One-way ANOVA following Tukey's post hoc test reveals the age group of 15-40 years was more sensitized than that of < 15 years and no male-female discrimination was found using the paired t test. House dust mites, namely Dermatophagoides pteronyssinus and Dermatophagoides farinae, elicited most significant SPT results (80.34 and 84.92%, respectively) followed by Cocos (73.28%) and Azaridacta (57.25%) pollen. The most sensitive mold was Alternaria alternata (26.9%). Allergic rhinitis, bronchial asthma and atopic dermatitis were recorded as the common symptoms. Other influencing factors were family history, nature and season/time of onset and house conditions., Conclusion: Following the increasing trend, house dust mite sensitization still held the dominance like in any other Indian population reported earlier. This study would pave the way to construct a standard and minimal SPT panel for the atopic patients of eastern India., (© 2018 S. Karger AG, Basel.)
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- 2019
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18. One generic synonym and one new species of Phlaeothripidae from India (Thysanoptera).
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Tyagi K, Singha D, Saha GK, and Kumar V
- Abstract
Haplothripsshivendraii Tyagi & Kumar, sp. n. is described from Rajasthan state of India. The monobasic Austro-oriental genus Dyothrips Kudô is formally synonymised with Haplothrips .
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- 2018
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19. Sensory organs of forensically important fly Ophyra capensis (Wiedemann, 1818) (Diptera: Muscidae): A scanning electron microscopic study.
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Hore G, Saha GK, and Banerjee D
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- Animals, Female, Flagella ultrastructure, Male, Sense Organs ultrastructure, Microscopy, Electron, Scanning methods, Muscidae ultrastructure, Sensilla ultrastructure
- Abstract
Dipterans, especially the sarcosaprophagous communities are of substantial importance from medical, veterinary and forensic entomological perspectives. Muscids are generally seen to colonize carcasses at advanced stages of decomposition when the initial dominance of calliphorids and sarcophagids subsides. Ophyra capensis (Wiedemann, 1818), a muscid fly with a relatively wide distribution range is considered of decent forensic relevance as it has been reported not only from cadavers placed outdoors but also from graves and exhumed corpses. The prime objective of the present study is to analyse and interpret the ultrastructural morphology of three sensory organs, namely, the ocellar region, compound eye and antenna of adult male and female Ophyra capensis with the help of scanning electron microscopy, so as to facilitate accurate morphological identification of the species in forensic entomological investigations. SEM analysis of the ocellar region revealed that it was larger in size in females and covered with microtrichia. Ultrastructural analysis of the compound eye indicated that the antero-frontally located ommatidia were larger in size in comparison to the rest of the facets, along with notable sexual dimorphism regarding the size of the ommatidia. The ultrastructure of the antenna displayed the presence of five types of sensilla, two types of chaetic sensilla on the scape and pedicel; trichoid sensilla and two types of basiconic sensilla on the flagellum along with numerous microtrichia. Both types of basiconic sensilla displayed a multiporous surface indicating their characteristic olfactory function. The morphological characteristics of these sensilla along with their probable functions are discussed in greater details., (Copyright © 2018 Elsevier B.V. All rights reserved.)
- Published
- 2018
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20. Sensitivity to House Dust Mites Allergens with Atopic Asthma and Its Relationship with CD14 C(-159T) Polymorphism in Patients of West Bengal, India.
- Author
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Ghosh A, Dutta S, Podder S, Mondal P, Laha A, Saha NC, Moitra S, and Saha GK
- Subjects
- Adolescent, Adult, Aged, Aged, 80 and over, Asthma parasitology, Child, Child, Preschool, Female, Humans, Hypersensitivity, Immediate parasitology, India epidemiology, Infant, Infant, Newborn, Male, Middle Aged, Young Adult, Antigens, Dermatophagoides immunology, Asthma epidemiology, Hypersensitivity, Immediate epidemiology, Lipopolysaccharide Receptors immunology
- Abstract
India is the home to around 15-20 million asthmatics, and asthma prevalence is increasing in Indian metropolitan area, including Kolkata, West Bengal. Complex interactions of genetic and environmental factors are involved in asthma. Genome-wide search for susceptible loci regulating IgE response (atopy) have identified a candidate gene CD14 which is most important in the context of allergic responses of respiratory system. This study was aimed to investigate the role of house dust and house dust mites in development of bronchial asthma and to explore the possible association of candidate gene CD14 with disease manifestation among Kolkata patient population. Skin-prick test was done among 950 asthmatic patients against 8 aeroallergens, including house dust and house dust mites and total serum IgE and allergen-specific IgE were measured. Polymerase chain reaction-restriction fragment length polymorphism was done in patients and nonasthmatic control (n = 255 in each) to characterize a functional polymorphism, C(-159)T, of CD14, a positional candidate gene for allergy. We identified house dust as the most common aeroallergen sensitizer among atopic patients in Kolkata followed by Dermatophagoides pteronyssinus and Dermatophagoides farinae Hughes (Acari: Pyroglyphidae) mites. Patient's sera contain significantly higher IgE level than that of control. Allergen-specific IgE antibody test revealed that 76.36% patients had specific IgE antibody against D. pteronyssinus mite. There was a significant difference in the distribution of alleles and genotypes for CD14 polymorphism with an increase in disease severity. So, in Kolkata, house dust mite is a common aeroallergen and D. pteronyssinus is predominant among mites. The present study revealed that bronchial asthma has a genetic background., (© The Author(s) 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.)
- Published
- 2018
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21. Offal dumping sites influence the relative abundance and roosting site selection of Black Kites (Milvus migrans govinda) in urban landscape: a study from Kolkata metropolis, India.
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Mazumdar S, Ghose D, and Saha GK
- Subjects
- Animals, Ecosystem, India, Meat, Abattoirs, Environmental Monitoring, Falconiformes
- Abstract
Although Black Kites (Milvus migrans govinda) serve as major scavenging raptor in most of the urban areas, scientific studies on this important ecosystem service provider are almost non-existent in Indian context. The present study was carried out in a metropolis in eastern India to find out the factors influencing relative abundance and roosting site selection of Black Kites. Separate generalized linear models (GLMs) were performed considering encounter rate and roosting Black Kite abundance as response variables. The study conclusively indicated that encounter rates of Black Kites were significantly influenced by the presence of garbage dumps in its vicinity. Numbers of Black Kites were also higher in the roosting sites situated closer to garbage dumps and open spaces. In addition, expected counts of Black Kites significantly increased in roosting sites situated away from buildings and water bodies. However, built-up area and tree cover around the roosting sites had no influence on the abundance of Black Kites therein. With rapid urbanization and changing offal disposal patterns, our findings would be useful to ensure continued availability of food and roosting sites of Black Kites in urban areas.
- Published
- 2017
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22. Role of offending out-door aero-allergen and CD14 C(-159)T polymorphism in development and severity of asthma in a Kolkata patient population.
- Author
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Dutta S, Mondal P, Saha NC, Moitra S, Podder S, Ghosh A, and Saha GK
- Subjects
- Adolescent, Asthma blood, Biomarkers blood, Case-Control Studies, Child, Female, Genetic Predisposition to Disease, Humans, Hypersensitivity, Immediate, Immunoglobulin E blood, Male, Polymorphism, Single Nucleotide, Skin Tests, Young Adult, Allergens immunology, Asthma genetics, Asthma immunology, Immunoglobulin E immunology, Lipopolysaccharide Receptors genetics, Polymorphism, Genetic, Promoter Regions, Genetic genetics, Promoter Regions, Genetic immunology
- Abstract
Objective: Present study involved identification of offending out-door aero-allergens and associated genetic pathway in nasso-bronchial asthma among Kolkata population., Methods: Skin-prick test was done among 950 asthmatic patients against 11 common aero-allergens and total serum IgE concentration was measured. PCR-RFLP was done in patients and non-asthmatic control (n=220 in each) to characterize functional polymorphism, C(-159)T, of CD14, a positional candidate gene for allergy. Association of genetic polymorphisms was made with clinico-pathological conditions., Results: We identified Cocos nucifera as the most common aero-allergen sensitizer among atopic patients in Kolkata. Patients with childhood-onset asthma were significantly more sensitive towards aero-allergens and had significantly higher serum IgE level than those of adult-onset (p< 0.0001). No significant difference was found in distribution of SNP genotypes of CD14 among case and control (p=0.178). However among patients, frequency of C allele is significantly higher in childhood-onset group than that of adult-onset and concordantly in former CC genotype was associated with significant higher level of serum IgE than CT and TT., Conclusion: In Kolkata, pollen is a common out-door aero-allergen and Cocos nucifera is predominant among pollens. Childhood-onset and adult-onset of asthma showed significant difference in allergen sensitivity as well as genetic background with respect to CD14 polymorphism.
- Published
- 2017
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23. Altitudinal variation and bio-climatic variables influencing the potential distribution of Culicoides orientalis Macfie, 1932, suspected vector of Bluetongue virus across the North Eastern Himalayan belt of Sikkim.
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Mukhopadhyay E, Hazra S, Saha GK, and Banerjee D
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- Animals, Bluetongue transmission, Bluetongue virus, Geography, Sikkim, Altitude, Ceratopogonidae, Insect Vectors, Rain, Temperature
- Abstract
Culicoides orientalis was first recorded from Sikkim, in the year 1963, but no evidence based disease outbreak were available. In the last 50 years, 260 Bluetongue disease outbreaks caused by Culicoides species have been evidenced from India. Moreover, in recent years with increase of average temperature worldwide and increase in longevity of arthropod vectors like Culicoides along with a geographical range shift to new suitable warmer regions has increased the potentiality of vector borne disease outbreak throughout the world. The Himalayan range of Sikkim in India is a biodiversity hotspot and is extremely sensitive to such global climate changes. An attempt has been made to evaluate the altitude, climate and environmental data on selected study sites of Sikkim for a period of two years (2014-2015) for discerning potential distribution of C.orientalis in this region. The altitude, temperature, precipitation and potential distribution range maps of C. orientalis showed the areas of highest species abundance within the altitudinal range of 550-1830m, with some species extending its range up to 3750m, with average precipitation of 2010-2590mm and mean temperature of 11-18°C. The Maximum Entropy Modelling (MaxEnt) and the Jackknife test of the MaxEnt model further revealed that the major contributing factors governing C. orientalis distribution are annual precipitation (78.8%), followed by precipitation of driest quarter (8.3%) and mean temperature of the warmest quarter (3.3%). Accuracy of the study was evaluated by the area under the curve (AUC=0.860). The Biplot on F
1 -F2 axes (N=16, α=0.05) in the PCA showed the linear depiction of all the variables considered in our study, major contributors were annual precipitation, precipitation of driest quarter and mean temperature of warmest quarter being the primary factors governing species distribution, as analogous to results of the MaxEnt model. This study would help in developing strategies for monitoring and managing surveillance programmes to control the chances of disease spread to livestock animals and also validate the predictions on the eventual spread of the vector midges to higher altitudes of Sikkim., (Copyright © 2017 Elsevier B.V. All rights reserved.)- Published
- 2017
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24. Assessment of fine-scale resource selection and spatially explicit habitat suitability modelling for a re-introduced tiger ( Panthera tigris ) population in central India.
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Sarkar MS, Krishnamurthy R, Johnson JA, Sen S, and Saha GK
- Abstract
Background: Large carnivores influence ecosystem functions at various scales. Thus, their local extinction is not only a species-specific conservation concern, but also reflects on the overall habitat quality and ecosystem value. Species-habitat relationships at fine scale reflect the individuals' ability to procure resources and negotiate intraspecific competition. Such fine scale habitat choices are more pronounced in large carnivores such as tiger ( Panthera tigris ), which exhibits competitive exclusion in habitat and mate selection strategies. Although landscape level policies and conservation strategies are increasingly promoted for tiger conservation, specific management interventions require knowledge of the habitat correlates at fine scale., Methods: We studied nine radio-collared individuals of a successfully reintroduced tiger population in Panna Tiger Reserve, central India, focussing on the species-habitat relationship at fine scales. With 16 eco-geographical variables, we performed Manly's selection ratio and K-select analyses to define population-level and individual-level variation in resource selection, respectively. We analysed the data obtained during the exploratory period of six tigers and during the settled period of eight tigers separately, and compared the consequent results. We further used the settled period characteristics to model and map habitat suitability based on the Mahalanobis D
2 method and the Boyce index., Results: There was a clear difference in habitat selection by tigers between the exploratory and the settled period. During the exploratory period, tigers selected dense canopy and bamboo forests, but also spent time near villages and relocated village sites. However, settled tigers predominantly selected bamboo forests in complex terrain, riverine forests and teak-mixed forest, and totally avoided human settlements and agriculture areas. There were individual variations in habitat selection between exploratory and settled periods. Based on threshold limits of habitat selection by the Boyce Index, we established that 83% of core and 47% of buffer areas are now suitable habitats for tiger in this reserve., Discussion: Tiger management often focuses on large-scale measures, but this study for the first time highlights the behaviour and fine-scale individual-specific habitat selection strategies. Such knowledge is vital for management of critical tiger habitats and specifically for the success of reintroduction programs. Our spatially explicit habitat suitability map provides a baseline for conservation planning and optimizing carrying capacity of the tiger population in this reserve., Competing Interests: The authors declare there are no competing interests.- Published
- 2017
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25. Scanning electron microscopic studies on antenna of Hemipyrellia ligurriens (Wiedemann, 1830) (Diptera: Calliphoridae)-A blow fly species of forensic importance.
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Hore G, Maity A, Naskar A, Ansar W, Ghosh S, Saha GK, and Banerjee D
- Subjects
- Animals, Entomology, Female, Forensic Sciences, Male, Microscopy, Electron, Scanning, Sensilla ultrastructure, Diptera anatomy & histology
- Abstract
Blow flies (Diptera: Calliphoridae) are one of the foremost organisms amongst forensic insects to colonize corpses shortly after death, thus are of immense importance in the domain of forensic entomology. The blow fly Hemipyrellia ligurriens (Wiedemann, 1830) (Diptera: Calliphoridae) is considered as a forensically important fly species globally and is also known for its medical and veterinary importance. In the present study, we report for the first time scanning electron microscopic studies on the morphology of sensilla of antenna of adult male and female of H. ligurriens is with profound importance in better understanding of the insect morphology from forensic entomological perspective, and also could aid in proper identification of the species from other calliphorid flies. The structural peculiarities observed in the (i) antenna of H. ligurriens with three segments- scape, pedicel and flagellum with dorso-laterally placed arista (ii) densely covered microtrichia and most abundant trichoid sensilla identified on the antenna (iii) observation of only one type of sensilla, chaetic sensilla (ChI) on the scape (iv) two types of chaetic sensilla (ChI and ChII) and styloconic sensilla on the pedicel (v) the flagellum with three types of sensilla- trichoid, basiconic and coeloconic sensilla (vi) Basiconic sensilla with multiporous surfaces with characteristic olfactory function. Moderate sexual dimorphism in the width of the flagellum, the females with wider flagella than the males, bear significance to the fact that they bear more multi-porous sensilla than the males, thus suffice their need to detect oviposition sites. Significant difference was observed in the length and width of coeloconic sensilla between the two sexes, the females showed bigger coeloconic sensilla, suggesting their function in oviposition site detection and successful colonization in corpses., (Copyright © 2017 Elsevier B.V. All rights reserved.)
- Published
- 2017
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26. Reversion of BDNF, Akt and CREB in Hippocampus of Chronic Unpredictable Stress Induced Rats: Effects of Phytochemical, Bacopa Monnieri .
- Author
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Hazra S, Kumar S, Saha GK, and Mondal AC
- Abstract
Objective: The aims of the present study were to explore the behavioural effects and to understand the possible mode of action of Bacopa monnieri extract (BME) on chronic unpredictable stress (CUS) induced depressive model and the biochemical alterations such as brain derived neurotrophic factor (BDNF), Akt, cyclic-AMP response element binding (CREB) protein level in the hippocampus of rats., Methods: We examined the effects of chronic administration of BME on CUS exposed rats for 28 days. Behavioural changes were assessed by sucrose consumption and open field test to assess the effect of BME on CUS-induced depression. The mechanisms underlying antidepressant like action of BME was further evaluated by measuring levels of BDNF, Akt, and CREB in the hippocampus of rat brain and compared with the standard tricyclic antidepressant drug imipramine (20 mg/kg body weight)., Results: Exposure to CUS for 28 days produced depression-like behavior in rats, as indicated by significant decreases in sucrose consumption, locomotor activity including decreased BDNF, Akt and CREB levels in the hippocampus. Daily administration of BME at a dose of (80 mg/kg body weight) significantly reverses the behavioral alteration and restored the normal level of BDNF, total and phospho-Akt, total and phospho CREB in the hippocampus of CUS induced rats as compared to vehicle treated control rats., Conclusion: These findings suggest that BME ameliorates CUS induced behavioural depression in rats and that can be used as a potent therapeutic agent in treating depressive like behavior.
- Published
- 2017
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27. An annotated checklist of Culicoides Latreille, 1809 (Insecta: Ceratopogonidae: Diptera) with incorporation of a vector species list from India.
- Author
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Mukhopadhyay E, Mazumdar A, Joardar SN, Saha GK, and Banerjee D
- Subjects
- Animal Distribution, Animals, Female, India, Insect Vectors classification, Ceratopogonidae classification, Checklist
- Abstract
Culicoides Latreille, 1809 (Insecta : Diptera : Ceratopogonidae) are small nematocerous biological vectors of a wide range of pathogens of veterinary and medical importance. They are distributed worldwide but prefer warm, damp, and muddy areas. Female midges require blood for egg maturation. Studies on taxonomy, proper identification keys, and distribution patterns of these flies across different geographical regions of India of these flies are limited. This article provides an updated checklist of Culicoides spp. from India collected from various scattered publications, along with their synonyms and details on their subgenera, geographical distribution, and type locality. A compiled list of different Culicoides vectors from India has also been included separately in this article, along with the type of the diseases spread., (© 2016 The Society for Vector Ecology.)
- Published
- 2016
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28. Metrocoris Mayr (Insecta: Hemiptera: Gerridae) of India with descriptions of five new species.
- Author
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Basu S, Polhemus DA, Subramanian KA, Saha GK, and Venkatesan T
- Subjects
- Animals, Female, Heteroptera growth & development, India, Male, Nymph anatomy & histology, Species Specificity, Heteroptera anatomy & histology, Heteroptera classification
- Abstract
The Metrocoris fauna of India is reviewed and five new species are described from India: M. murtiensis Basu, Polhemus and Subramanian sp. nov. belonging to the nigrofasciatus species group, M. dinendrai Basu, Polhemus and Subramanian sp. nov. and M. darjeelingensis Basu, Polhemus and Subramanian sp. nov. of the compar species group, M. deceptor Basu, Polhemus and Subramanian sp. nov. (previously treated as M. quynhi Tran & Zettel in Basu et al., 2015) of the anderseni species group, and M. lavitra Basu, Polhemus, Subramanian and Saha sp. nov., which does not fit well into any currently established species group. The new species proposed are compared to all other known species, and a key to all the species of Indian Metrocoris is provided, accompanied by a table for comparison of key morphological characters, and a map and table of distributional details.
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- 2016
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29. Pupal productivity & nutrient reserves of Aedes mosquitoes breeding in sewage drains & other habitats of Kolkata, India: Implications for habitat expansion & vector management.
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Banerjee S, Mohan S, Saha N, Mohanty SP, Saha GK, and Aditya G
- Subjects
- Aedes growth & development, Animals, Breeding, Dengue transmission, Ecosystem, Female, Humans, India, Larva virology, Mosquito Control, Pupa virology, Sewage virology, Aedes virology, Dengue virology, Dengue Virus, Insect Vectors virology
- Abstract
Background & Objectives: The quality of breeding sites is reflected through the pupal productivity and the life history traits of Aedes mosquitoes. Using nutrient reserves and pupal productivity of Aedes as indicators, the larval habitats including sewage drains were characterized to highlight the habitat expansion and vector management., Methods: The pupae and adults collected from the containers and sewage drains were characterized in terms of biomass and nutrient reserves and the data were subjected to three way factorial ANOVA. Discriminant function analyses were performed to highlight the differences among the habitats for sustenance of Aedes mosquitoes., Results: Survey of larval habitats from the study area revealed significant differences (P<0.05) in the pupal productivity of Aedes among the habitats and months. Despite sewage drains being comparatively less utilized for breeding, the pupae were of higher biomass with corresponding adults having longer wings in contrast to other habitats. The nutrient reserve of the adults emerging from pupae of sewage drains was significantly higher (P<0.05), compared to other habitats, as reflected through the discriminant function analysis., Interpretation & Conclusions: The present results showed that for both Ae. aegypti and Ae. albopictus, sewage drains were equally congenial habitat as were plastic, porcelain and earthen habitats. Availability of Aedes immature in sewage drains poses increased risk of dengue, and thus vector control programme should consider inclusion of sewage drains as breeding habitat of dengue vector mosquitoes.
- Published
- 2015
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30. Household Wastes as Larval Habitats of Dengue Vectors: Comparison between Urban and Rural Areas of Kolkata, India.
- Author
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Banerjee S, Aditya G, and Saha GK
- Subjects
- Aedes virology, Animals, Dengue prevention & control, India, Insect Vectors virology, Larva, Mosquito Control, Dengue Virus physiology, Ecosystem, Insect Vectors physiology, Waste Products
- Abstract
Porcelain and plastic materials constitute bulk of household wastes. Owing to resistibility and slow degradability that accounts for higher residence time, these materials qualify as potential hazardous wastes. Retention of water permits these wastes to form a congenial biotope for the breeding of different vector mosquitoes. Thus porcelain and plastic wastes pose a risk from public health viewpoint. This proposition was validated through the study on the porcelain and plastic household wastes as larval habitats of Dengue vectors (Aedes spp.) in rural and urban areas around Kolkata, India. The wastes were characterized in terms of larval productivity, seasonal variation and a comparison between urban and rural areas was made using data of two subsequent years. The number of wastes positive as larval habitats and their productivity of Aedes spp. varied among the types of household wastes with reference to months and location. Multivariate analysis revealed significant differences in the larval productivity of the household wastes based on the materials, season, and urban-rural context. Results of Discriminant Analysis indicated differences in abundance of Ae. aegypti and Ae. albopictus for the urban and rural areas. The porcelain and plastic wastes were more productive in urban areas compared to the rural areas, indicating a possible difference in the household waste generation. A link between household wastes with Aedes productivity is expected to increase the risk of dengue epidemics if waste generation is continued without appropriate measures to limit addition to the environment. Perhaps, alternative strategies and replacement of materials with low persistence time can reduce this problem of waste and mosquito production.
- Published
- 2015
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31. Intraguild Predation in Heteroptera: Effects of Density and Predator Identity on Dipteran Prey.
- Author
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Brahma S, Sharma D, Kundu M, Saha N, Saha GK, and Aditya G
- Subjects
- Animals, Culicidae, Larva, Population Density, Heteroptera physiology, Predatory Behavior
- Abstract
In tropical freshwaters, different species of water bugs (Heteroptera) constitute a guild sharing similar prey resources including chironomid and mosquito larvae. Assuming possibilities of intraguild predation (IGP) among the constituent members, an attempt was made to evaluate the effects of prey and predator density on the mortality of mosquito and chironomid larvae (shared prey), using Laccotrephes griseus Guérin-Méneville (Hemiptera: Nepidae) and Ranatra filiformis Fabricius (Hemiptera: Nepidae) as IG predators and Anisops bouvieri Kirkaldy (Hemiptera: Notonectidae) as IG prey. The predation on mosquito and chironomid larvae varied with the density and combinations of the predators. When present as conspecific IG predators, L. griseus exhibited greater effect on the prey mortality than R. filiformis. The effects on shared prey suggest that the two predators are not substitutable in terms of the effect on the shared prey mortality. The mortality of A. bouvieri (IG prey) at low shared prey density was significantly different (p < 0.05) from high shared prey density. In view of predatory effect of the heteropteran predators on the dipteran larvae, the results suggest possible interference by the presence of A. bouvieri as an intermediate predator. It seems that the presence of heteropteran predators including A. bouvieri as IG prey may benefit the dipteran prey under situations when the density is low in tropical waters. The intensity of the predatory effect may differ based on the species composition at IG predator level. For mosquito biological control, the interactions between the predators may not be substitutable and are independent in their effects.
- Published
- 2015
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32. A new species of Aulacogenia Stål (Hemiptera: Heteroptera: Reduviidae: Stenopodainae) from India.
- Author
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Mukherjee P, Cai W, and Saha GK
- Subjects
- Animal Distribution, Animal Structures anatomy & histology, Animal Structures growth & development, Animals, Body Size, Ecosystem, Female, India, Male, Organ Size, Reduviidae anatomy & histology, Reduviidae growth & development, Reduviidae classification
- Abstract
A new stenopodaine reduviid, Aulacogenia darjeelingensis sp. nov. belonging to the "corniculata species group" from India is described and illustrated. A key to the Indian species of the genus Aulacogenia Stål is provided.
- Published
- 2015
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33. ASSESSMENT OF PUPAL PRODUCTIVITY OF AEDES AND CO-OCCURRING MOSQUITOES IN KOLKATA, INDIA.
- Author
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Mohan S, Banerjee S, Mohanty SP, Saha GK, and Aditya G
- Subjects
- Animals, Anopheles physiology, Culex physiology, Dengue transmission, Ecosystem, Female, India, Male, Pupa, Aedes physiology, Insect Vectors physiology, Mosquito Control
- Abstract
Monitoring of dengue vectors provide baseline information about the abundance and subsequent management strategy. An appraisal of mosquito abundance using dengue vectors as focal species was made in respect to Kolkata, India as geographical area. The data on immature abundance in the container larval habitats viz, earthen, porcelain and plastic materials were subjected to three-way factorial ANOVA, using months, habitats and species as variables. Similar tests were done on pupal weight and wing length. It was observed that Anopheles subpictus, Culex quinquefasciatus coexist with Ae. aegypti and Ae. albopictus in different container habitats, that varied with months and habitats. Ae. aegypti and Ae. albopictus were found in higher proportions in porcelain and plastic containers. In earthen containers a stable ratio of three mosquitoes was observed. Sex specific variations in pupal weight and wing length were noted in both species of Ae. aegypti and Ae. albopictus. The wing length of adult Aedes mosquitoes showed correspondence with pupal weight suggesting the use of pupal weight can be used as indicator of prospective adult body size. Although less known as container breeding, presence of An. subpictus and Cx. quinquefascistus along with Aedes indicates that availability of waste containers in environment increases risks of dengue and other mosquito borne diseases. The present habitat-based study calls for a strict vector management strategy to reduce the sources of ovipostion in various container habitats to minimize the mosquito vectors and thus potential risk of dengue and other mosquito borne diseases.
- Published
- 2014
34. Chironomid midges as allergens: evidence from two species from West Bengal, Kolkata, India.
- Author
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Nandi S, Aditya G, Chowdhury I, Das A, and Saha GK
- Subjects
- Analysis of Variance, Animals, Humans, Immunoglobulin E immunology, India, Skin immunology, Species Specificity, Statistics, Nonparametric, Allergens immunology, Chironomidae immunology, Hypersensitivity immunology
- Abstract
Background & Objectives: Arthropods of different taxonomic identity including chironomid midges are known to induce allergic response in humans. The present study was done to access two common chironomid species Chironomus circumdatus and Polypedilum nubifer for their sensitizing potential as an allergen in atopic patients and controls., Methods: Following preparation of allergenic extracts of the two chironomid species separately, 198 atopic patients attending an allergy clinic and 50 age matched controls were tested along with a routine panel of allergens to assess sensitization., Results: The skin prick test (SPT) results revealed that 189 of the 198 patients (95.4%) demonstrated sensitization to both the chironomid species. Higher levels of total IgE was observed in atopic subjects than in the control group., Interpretation & Conclusions: The results suggest that the chironomid midges Chironomus circumdatus and Polypedilum nubifer can elicit sensitization in humans. A potential risk for allergic reactions by susceptible individuals exists due to these chironomid species, owing to their abundance and chances of contact with human beings. Further studies may be initiated to characterize the nature of the allergens and to assess their clinical relevance.
- Published
- 2014
35. A new genus, Neoschidium (Hemiptera: Reduviidae: Emesinae), with a redescription of the type genus, Neoschidium phasma (Distant) [Ghilianella phasma Distant and Schidium phasma (Distant)], recorded for the first time from India.
- Author
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Mukherjee P, Ambrose DP, Saha GK, and Bal A
- Subjects
- Animals, Ecosystem, India, Male, Reduviidae anatomy & histology, Biodiversity, Reduviidae classification
- Abstract
A new genus, Neoschidium was erected with the type genus, Neoschidium phasma (Distant). It was earlier described under Ghilianella Spinola 1850 as G. phasma Distant and later under Schidium Bergroth 1916 as Schidium phasma (Distant) by Bergroth (1916). Because it exhibits characters not only of Ghilianella and Schidium but also intermediate specific characters that are not found in both the genera, the type genus Neoschidium phasma (Distant) is redescribed with additional taxonomic details, morphometrics, and illustrations. It is also recorded for the first time from India.
- Published
- 2014
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36. Prey preferences of aquatic insects: potential implications for the regulation of wetland mosquitoes.
- Author
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Saha N, Aditya G, and Saha GK
- Subjects
- Animals, Anura physiology, Food Chain, India, Larva, Population Density, Wetlands, Culicidae physiology, Fishes physiology, Food Preferences, Insecta physiology, Mosquito Control, Predatory Behavior
- Abstract
Wetlands are potential sites for mosquito breeding and are thus important in the context of public health. The use of chemical and microbial controls is constrained in wetlands in view of their potential impact on the diverse biota. Biological control using generalist aquatic insects can be effective, provided a preference for mosquito larvae is exhibited. The mosquito prey preferences of water bugs and larvae of odonate species were evaluated using chironomid larvae, fish fingerlings and tadpoles as alternative prey. Manly's selectivity (αi ) values with 95% confidence intervals (CIs) were estimated to judge prey preference patterns. Multivariate analysis of variance (manova) and standardized canonical coefficients were used to test the effects of density on prey selectivity. The αi values indicated a significant preference (P < 0.05) in all of the insect predators tested for mosquito larvae over the alternative prey as a density-dependent function. On a comparative scale, chironomid larvae had the highest impact as alternative prey. In a multiple-prey experiment, predators showed a similar pattern of preference for mosquito larvae over alternative prey, reflecting a significant (P < 0.05) niche overlap. The results suggest that, in a laboratory setting, these insect predators can effectively reduce mosquito density in the presence of multiple alternative prey., (© 2013 The Royal Entomological Society.)
- Published
- 2014
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37. Pupal productivity of dengue vectors in Kolkata, India: implications for vector management.
- Author
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Banerjee S, Aditya G, and Saha GK
- Subjects
- Animals, Culicidae genetics, Dengue genetics, Dengue virology, Dengue Virus pathogenicity, Female, Humans, India, Larva virology, Male, Mosquito Control, Pupa virology, Species Specificity, Culicidae virology, Dengue transmission, Dengue Virus isolation & purification, Insect Vectors genetics
- Abstract
Background & Objectives: Entomological surveillance of the dengue vectors using pupal productivity as indicators can be helpful in effective management. On this basis, an assessment was made on the relative importance of the larval habitats of Aedes mosquitoes in Kolkata, an endemic zone for dengue in West Bengal, India., Methods: Monthly collection of larvae and pupae of Aedes from larval habitats categorized as earthen, plastic and porcelain containers and tyres, was carried out from selected sites. Pupal weight was recorded and degree of sexual dimorphism was calculated. The data on pupal weight, sexual dimorphism and immature density were used for regression analysis., Results: The number of positive sites for each type of larval habitats varied with months and mosquito species. Based on mean density per month, the plastic containers were the most productive habitats and the tyres were least productive for both Aedes species. The pupal weight of both Ae. aegypti and Ae. albopictus varied with the relative density and type of larval habitats. Significant differences in pupal productivity, positive sites and the proportion of pupae were observed in the habitats. Species-specific differences in the degree of dimorphism were noted with the females being larger in size than males, irrespective of the habitats., Interpretation & Conclusions: Pupal productivity of Aedes mosquitoes in Kolkata differed in terms of the type of the larval habitats with the immature density affecting the body size of the adults. This habitat-based study is a pioneer effort considering Kolkata and calls for a management plan for source reduction of these habitats to minimize Aedes mosquitoes and thus potential risk of dengue.
- Published
- 2013
38. Apoptogenic effects of Tricholoma giganteum on Ehrlich's ascites carcinoma cell.
- Author
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Chatterjee S, Biswas G, Chandra S, Saha GK, and Acharya K
- Subjects
- Animals, Carcinoma, Ehrlich Tumor pathology, Cell Line, Tumor, Male, Mice, Treatment Outcome, Apoptosis drug effects, Carcinoma, Ehrlich Tumor drug therapy, Carcinoma, Ehrlich Tumor physiopathology, Cell Extracts therapeutic use, Tricholoma chemistry
- Abstract
This study explored the efficacy of Fa fraction of Tricholoma giganteum against Ehrlich's ascites carcinoma (EAC). Mechanisms of apoptogenic effect of the fraction were delineated. The flow cytometric analysis of EAC cells, showed an increase in number of cells in sub-G(0)/G(1) population and reduction in the G(2)/M phase due to the treatment thus suggesting apoptosis. The induction of apoptosis has also been confirmed by nuclear staining that demonstrated distinctive morphological features of apoptosis. Our data also revealed an increase in the expression of pro-apoptotic protein p53 in EAC and induced factors contributing to apoptosis. Pro-apoptotic gene Bax was up-regulated during p53-mediated apoptosis. No significant change in the expression of anti-apoptotic protein Bcl-2 was observed ensuing in decrease of the Bcl-2/Bax ratio. p53-mediated growth arrest involves p21 as a major effecter, which interestingly showed moderate elevation. All these observations indicate that Fa fraction of T. giganteum induces apoptogenic signal in EAC.
- Published
- 2013
- Full Text
- View/download PDF
39. Household disposables as breeding habitats of dengue vectors: linking wastes and public health.
- Author
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Banerjee S, Aditya G, and Saha GK
- Subjects
- Animals, Cities, Cluster Analysis, Dengue transmission, Ecosystem, Humans, Larva, Population Density, Reproduction, Aedes, Household Products, Insect Vectors, Waste Products
- Abstract
An assessment of the household wastes as larval habitats of the dengue vectors was made considering Kolkata, India, as geographical area. Wastes of four major categories, namely, earthen, porcelain, plastic and coconut shells were monitored for positive with immature of either Aedes aegypti or Aedes albopictus. Twenty six types of wastes with varying size and shape, resembling containers, were identified that hosted mosquito immature. The number of waste containers positive for Aedes immature varied significantly (P<0.05) with respect to location, type and month. The relative density of Aedes immature in the waste containers varied significantly (P<0.05) with the types and months. The significant interaction between the month, waste container types and density of Aedes immature suggest that the household wastes are important contributors to the maintenance of the population of Aedes mosquito in the city. Based on the relative density of mosquito immature in the wastes, cluster analysis allowed segregation and classification of the wastes and their importance as mosquito larval habitats. Apparently, the containers that are most frequently disposed off contributed largely to the sustenance of Aedes mosquito population in the city. This calls for a strict legislation towards disposal as well as enhanced management of the household wastes. A link between the wastes disposed and subsequent conversion to the mosquito larval habitats cautions for continuance of Aedes population and possibility of dengue epidemics if the existing management practices are not improved., (Copyright © 2012 Elsevier Ltd. All rights reserved.)
- Published
- 2013
- Full Text
- View/download PDF
40. Overview of the species of Aphelocheirus (Hemiptera: Heteroptera: Aphelocheiridae) of India, with description of a new species from West Bengal.
- Author
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Basu S, Subramanian KA, and Saha GK
- Subjects
- Animal Distribution, Animals, Heteroptera physiology, Species Specificity, Heteroptera anatomy & histology, Heteroptera classification
- Abstract
An overview and a key to the species of Aphelocheirus of India are given. Aphelocheirus (Aphelocheirus) thirumalaii sp. nov. from Gorumara National Park of Jalpaiguri district, West Bengal, is described. With this new species, eight other species of benthic water bugs (Aphelocheiridae) are reported from India. A distribution map of all known Indian species is also provided.
- Published
- 2013
- Full Text
- View/download PDF
41. An assessment of macroinvertebrate assemblages in mosquito larval habitats--space and diversity relationship.
- Author
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Banerjee S, Aditya G, Saha N, and Saha GK
- Subjects
- Animals, Food Chain, Pest Control, Biological, Biodiversity, Culicidae growth & development, Ecosystem, Environmental Monitoring, Invertebrates classification
- Abstract
The aquatic bodies designated as mosquito larval habitats are diverse in size and species composition. The macroinvertebrate predators in these habitats are elements that influence the abundance of mosquito species, providing a basis for biological control. Assessment of species assemblage in these habitats will indicate the possible variations in the resource exploitation and trophic interactions and, therefore, can help to frame biological control strategies more appropriately. In the present study, the species composition is being investigated in five different mosquito larval habitats at a spatial scale. A random sample of 80 each of the habitats, grouped as either small or large, was analyzed in respect to the macroinvertebrate species assemblage. The species composition in the habitats was noted to be an increasing function of habitat size (species number = 1.653 + 0.819 habitat size) and, thus, the diversity. The relative abundance of the mosquito immatures varied with the habitat, and the number of useful predator taxa was higher in the larger habitats. In the smaller habitats-plastic and earthen structures and sewage drains, the relative and absolute number of mosquito immatures per sampling unit were significantly higher than the pond and rice field habitats. This was evident in the cluster analysis where the smaller habitats were more related than the larger habitats. The principal component analysis on the species diversity yielded four and six components, respectively, for the smaller and larger habitats for explaining the observed variance of species abundance. The species composition in the habitats was consistent with the earlier findings and support that the abundance of coexisting macroinvertebrate species regulates the relative load of mosquito immatures in the habitats. The findings of this study may be further tested to deduce the relative importance of the habitats in terms of the productivity of mosquito immatures at a temporal scale.
- Published
- 2010
- Full Text
- View/download PDF
42. Incrimination of Blomia tropicalis as a Potent Allergen in House Dust and Its Role in Allergic Asthma in Kolkata Metropolis, India.
- Author
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Podder S, Gupta SK, and Saha GK
- Abstract
Background: The increasing trend in allergic diseases has become obvious in the present day, especially in developing countries like India, because of many factors such as change in ambient air quality, increased air pollution, metamorphic change in living habits and lifestyle, and climate.1 Mites present in house dust represent a major source of allergens, resulting in different allergic manifestations all over the world, and hypersensitivity to these dust mites may play a pivotal role in pathogenesis of several allergic complaints including bronchial asthma. The present study evaluated the sensitization toward house dust and house dust mites among patients residing in Kolkata metropolis, India, who are suffering from allergic asthma., Methods: The skin prick test was performed on a total of 1079 patients (585 males and 494 females) between the age group 5-50 years and 50 healthy controls using a variety of 16 common aero-allergenic extracts including 4 allergens of interest, viz. Dermatophagoides pteronyssinus, Dermatophagoides farinae, and Blomia tropicalis and total house dust allergens. Total serum IgE level was measured by using the EIA technique and specific IgE levels against aforesaid allergens were detected with the Pharmacia ImmunoCAP 100 System. The influence of age and sex, if any, on allergen sensitivity was also investigated. All statistical analyses were performed using SPSS 10.0 for Windows and Zar.2, Results: THE RESPONSES AMONG PATIENTS WITH ASTHMA TO HOUSE DUST AND HOUSE DUST MITE ALLERGEN TESTS WERE AS FOLLOWS: house dust (96.22%), D. pteronyssinus (75.06%), B. tropicalis (72%), and D. farinae (63.72%). The frequency of positive skin response was found to be independent of age and sex. The total serum IgE levels in patients varied between 7.3 and 4040 IU/ml (mean 369 ± 26.51 IU/ml). Specific IgE antibody test proved that 83% patients showed sensitivity toward at least 1 of the allergens tested., Discussion: The results indicate that patients are highly sensitive to house dust and 3 other allergenic mites, namely, D. pteronyssinus, D. farinae, and B. tropicalis, as evidenced by the skin prick test, quantification of total serum IgE, and detection of allergen-specific IgE antibodies among patients of Kolkata. Although mites belonging to the genus Dermatophagoides have already been incriminated as a major source of allergen in house dust in India, this is the first time the role of B. tropicalis mites causing allergic asthma has been reported from an Indian population. Thus, the importance of B. tropicalis mite as an aetiopathological agent in causing various allergic manifestations among the Kolkata population should not be undermined and the allergen should be included in routine allergy testing.
- Published
- 2010
- Full Text
- View/download PDF
43. Immatures of Aedes aegypti in Darjeeling Himalayas--expanding geographical limits in India.
- Author
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Aditya G, Pramanik MK, and Saha GK
- Subjects
- Animals, Climate, Geography, India, Population Density, Aedes physiology, Demography
- Published
- 2009
44. Predatory efficiency of the sewage drain inhabiting larvae of Toxorhynchites splendens Wiedemann on Culex quinquefasciatus Say and Armigeres subalbatus (Coquillett) larvae.
- Author
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Aditya G, Bhattacharyya S, Kundu N, Kar PK, and Saha GK
- Subjects
- Animals, Larva, Pupa, Culex physiology, Culicidae physiology, Insect Vectors, Mosquito Control, Predatory Behavior, Sewage
- Abstract
The rate of predation by stage IV instar Toxorhynchites splendens larvae on the equivalent instar stage larvae of Culex quinquefasciatus and Armigeres subalbatus, co-occurring in sewage drains, were noted for a period of three consecutive days in the laboratory using different prey densities and combinations. The rate of predation varied by age of the predator, density of prey, and prey type. The number of Ar. subalbatus larvae consumed by a single Tx. splendens larva ranged between 0.50 +/- 0.71 and 16.40 +/- 2.01; while for Cx. quinquefasciatus larvae, the number consumed ranged from 0.20 +/- 0.42 to 20.40 +/- 1.43 per day. The pupation rates of the prey species varied in respect to control, with a minimum of 0.20 +/- 0.42 pupa/day to a maximum of 12.20 +/- 2.30 pupa/day in the presence of Tx. splendens. The values for the controls were 1.00 +/- 0.87 and 14.44 +/- 2.83 pupa/day, respectively. Irrespective of prey densities and combinations, a single Tx. splendens fourth instar larvae was found to consume on average 10.07 larvae on the first day 16.57 larvae on the second day and 4.38 larvae on the third day, killing a total of 17.70 to 45.10 larvae, in three days. In the presence of Tx. splendens, the cumulative pupation, irrespective of prey, remained between 12.20 and 45.10, and differed significantly from control where the values were between 13.90 and 54.70. The results indicate that Tx. splendens can significantly reduce immature numbers and lower the rate of pupation of Cx. quinquefasciatus and Ar. subalbatus. Tx. splendens may be a potential biological resource in the control of mosquitoes inhabiting sewage drains.
- Published
- 2007
45. Predatory activity of Rhantus sikkimensis and larvae of Toxorhynchites splendens on mosquito larvae in Darjeeling, India.
- Author
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Aditya G, Ash A, and Saha GK
- Subjects
- Animals, India, Larva physiology, Population Density, Time Factors, Coleoptera physiology, Culicidae physiology, Predatory Behavior physiology
- Abstract
Background and Objectives: Predation potential of the dytiscid beetle, Rhantus sikkimensis Regimbart 1899 and the larvae of Toxorhynchites splendens Wiedemann 1819 occurring along with the larval stages of the mosquitoes in the annual lentic water bodies of Darjeeling was evaluated using the larvae of Culex quinquefasciatus Say 1823 as preys, in the laboratory under simulated natural conditions., Methods: Field collected R. sikkimensis and larvae of Tx. splendens were offered IV instar larvae of Cx. quinquefasciatus to observe the rate of predation, at varying prey and predator densities. Based on the data obtained on the predation for a period of three consecutive days, two indices of predation, predatory impact (PI) and clearance rate (CR) values were estimated, and compared between the predator species., Results: The rate of predation of IV instar Cx. quinquefasciatus larvae by R. sikkimensis ranged between 21.56 and 86.89 larvae per day, depending on the prey and predator densities. The PI value remained between 18.67 and 35.33 larvae/day depending on prey densities, while the CR ranged between 2.21 and 2.23 larvae litres/day/predator. Compared to these, the Tx. splendens larvae consumed the prey larvae at the rate of 0.67 to 34.22 larvae per day, depending on the prey and predator densities. The PI value ranged between 7.67 and 11.33 larvae/day, and the CR value ranged between 1.41 and 1.76 larvae litres/day/predator. The rate of predation, CR values and PI values of R. sikkimensis and Tx. splendens varied significantly., Interpretation and Conclusion: Both the predators R. sikkimensis and larvae of Tx. splendens can consume a good number of mosquito larvae, though the rate of consumption between the two predators vary owing to the difference in the life history traits and features. It can be assumed that these predators play an important role in larval population regulation of mosquitoes and thereby impart an effect on species composition and interactions in the aquatic insect communities of Darjeeling Hills, India.
- Published
- 2006
46. Larval habitats and species composition of mosquitoes in Darjeeling Himalayas, India.
- Author
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Aditya G, Pramanik MK, and Saha GK
- Subjects
- Animals, Attitude, Data Collection, Demography, India, Larva physiology, Biodiversity, Culicidae physiology, Environment
- Abstract
Background & Objectives: A preliminary survey of larval mosquito habitats and temporal variation in mosquito diversity in the hill town of Darjeeling, India was made during 2003, for a qualitative and quantitative assessment of mosquito distribution., Methods: The possible larval habitats of mosquitoes were surveyed and the species diversity in the sites positive for mosquito larvae was noted. Bi-weekly sampling from a particular habitat was carried out to reveal the temporal variation in mosquito species., Results: A good number of lentic aquatic habitats were found to be hosting mosquito immatures, though difference in the physical and biological features of these habitats was prominent. Altogether, immatures of six mosquito species, belonging to four genera--Aedes, Armigeres, Culex and Toxorhynchites were noted with significant difference in temporal variation in their relative and absolute numbers. A positive correlation (r = + 0.707) was found between population of the prey mosquito immatures and the population of immatures of Tx. splendens. The species diversity index (H') for the mosquitoes remained between 0.87 and 1.53. The evenness components ranged between 54.03 and 95.03% and differed significantly., Interpretation & Conclusion: In the present study, the aquatic bodies could be categorised into six types depending on the size and structural complexity that may account for the observed variation in the species composition of the larval habitats. In addition to this, other factors like temperature, rainfall and other related climatic attributes may be responsible for the observed species variation, which needs to be confirmed through further studies.
- Published
- 2006
47. Frequency-dependent prey-selection of predacious water bugs on Armigeres subalbatus immatures.
- Author
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Aditya G, Bhattacharyya S, Kundu N, and Saha GK
- Subjects
- Animals, India, Larva, Population Density, Regression Analysis, Culicidae, Heteroptera physiology, Models, Biological, Predatory Behavior physiology
- Abstract
Background & Objectives: The predatory behaviour with reference to the frequency-dependent prey-selection of the water bugs Sphaerodema annulatum Fabricius and S. rusticum Fabricius was studied in the laboratory using the IV instar larvae and pupae of Armigeres subalbatus as prey to ascertain their efficacy as predator of mosquito immatures., Methods: Field collected adult morphs of the water bugs were allowed to predate on larvae and pupae provided in different ratios and densities as per the model of Greenwood and Elton' for a fixed time period. The data obtained on their predation rate were analysed with respect to the model parameters, lnV--the frequency independent component and b--the frequency dependent component of selection., Results: It was found that the prey-selection was dependent on the relative numbers of prey available, favouring apostatic selection. The b values and lnV values for S. annulatum were 0.54 +/- 0.01 and 0.92 +/- 1.04 respectively whereas the corresponding values for S. rusticum were 0.71 +/- 0.03 and 0.17 +/- 1.57 respectively., Interpretation & Conclusion: The selection of preys by the water bugs was dependent on the relative number of the prey forms and thus they are expected to predate on the form more abundant in a heterogeneous prey population and adversely affect the adult emergence.
- Published
- 2005
48. Predatory efficiency of the water bug Sphaerodema annulatum on mosquito larvae (Culex quinquefasciatus) and its effect on the adult emergence.
- Author
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Aditya G, Bhattacharyya S, Kundu N, Saha GK, and Raut SK
- Subjects
- Animals, Fresh Water, India, Larva physiology, Population Dynamics, Reproduction physiology, Culex physiology, Ecosystem, Heteroptera physiology, Mosquito Control methods, Predatory Behavior physiology
- Abstract
The daily number of IV instar larva of Culex quinquefasciatus killed, rate of pupation and adult emergence was noted in presence of the predatory water bug Sphaerodema annulatum for a period of seven consecutive days, experimentally, in the laboratory. The rate of IV instar larva killed by the water bugs on an average was 65.17 per day. The rate of pupation ranged between 7.6 and 48 in control while in presence of water bugs it ranged between 6 and 35. The rate of adult emergence in control experiments varied between 1.4 and 4.8 per day, which was reduced to only 0.4-28.8 per day in case of the water bugs. The results clearly indicate that the water bugs on its way of predation reduces the rate of pupation and adult emergence of Cx. quinquefasciatus significantly which calls for an extensive field trials.
- Published
- 2004
- Full Text
- View/download PDF
49. Disregulated expression of the Th2 cytokine gene in patients with intraoral squamous cell carcinoma.
- Author
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Agarwal A, Rani M, Saha GK, Valarmathi TM, Bahadur S, Mohanti BK, and Das SN
- Subjects
- Adult, Aged, Carcinoma, Squamous Cell immunology, Carcinoma, Squamous Cell pathology, Female, Gene Expression Regulation, Neoplastic, Humans, Male, Middle Aged, Mouth Neoplasms immunology, Mouth Neoplasms pathology, RNA, Messenger analysis, Reverse Transcriptase Polymerase Chain Reaction, Th1 Cells physiology, Carcinoma, Squamous Cell genetics, Cytokines genetics, Mouth Neoplasms genetics, T-Lymphocyte Subsets physiology, Th2 Cells physiology
- Abstract
It has been seen that advanced stage oral squamous cell carcinoma is associated with impaired T-cell function and higher antibody response. In order to find out if such immune disregulation is associated with alteration of T-helper (Th) type CD4+ T-cell phenotype leading to altered cytokine production, we studied the Th-like cytokine profile in 35 oral squamous cell carcinoma patients and 21 normal controls. Concomitant expression of both Th1 and Th2 cytokine genes was studied by reverse transcription and Polymerase Chain Reaction (PCR) based amplification (RT-PCR) of mRNA extracted from freshly isolated peripheral blood mononuclear cells (PBMC) using specific primers for Interferon (IFN)-gamma, Interleukin (IL)-2, IL-4 and IL-10. Almost 63% of oral cancer patients showed polarization of a Th-like cytokine response as compared to 33% of the normal controls while 66.6% of normal controls showed a predominantly non-polarized Th0 response. Expression of IFN-gamma and IL-2 genes was more commonly seen in the early stage of the disease (p < 0.02) whereas majority of advanced stage tumours was associated with enhanced expression of IL-4 and IL-10 but not IFN-gamma and IL-2 genes. Patients with lymphnode metastases and poorly differentiated tumours expressed IL-4 and IL-10 more frequently with concomitant suppression of IFN-gamma and IL-2 genes. It seems therefore, that the development of oral squamous cell carcinoma leads to polarization of cytokine gene expression that is skewed towards the Th1-like response in the early stage. However, increasing tumour load and lymphnode invasion suppresses Th1 cytokine genes, thus skewing it toward a Th2-like cytokine response.
- Published
- 2003
- Full Text
- View/download PDF
50. Incidence and prognostic significance of right bundle branch block complicating acute myocardial infarction.
- Author
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Islam MN, Ali MA, Saha GK, Islam MF, Islam KQ, and Rahman MS
- Subjects
- Adult, Aged, Female, Hospital Mortality, Humans, Male, Middle Aged, Myocardial Infarction drug therapy, Myocardial Infarction mortality, Prognosis, Prospective Studies, Thrombolytic Therapy, Bundle-Branch Block complications, Myocardial Infarction complications
- Abstract
The incidence and hospital courseofacute myocardial infarction wereobserved among randomly selected 560 patients. The mean age of the patients was 53 +/- 6.67 years with male-female ratio 2.6:1. The incidence of right bundle branch block (RBBB) was 15% (84 out of 560 patients). New RBBB, old RBBB and RBBB of indeterminate age were observed in 33 (39.25%), 23 (27.40%) and 28 (33.25%) cases respectively. RBBB was isolated in 50 (60%) cases and bi-fascicular in remaining 34 (40%) cases. The rate of use of thrombolytic was greater in RBBB group than non-RBBB group (52% vs 30.67%, P < 0.05). The complications were more frequently observed in patients with RBBB: in-hospital mortality, 27.40% vs 10.90% (P < 0.01); use of temporary pacemaker, 15% vs 9% (P < 0.05); and heart failure, 50% vs 35% (P < 0.05). In sub-group analysis, in-hospital mortality rate was higher among bi-fascicular group than isolated RBBB group (P < 0.05). Thus it appeared from the results that the incidence of RBBB is relatively common i.e. 15% over all (84 out of 560) and 5.90% new (33 out of 560) and despite greater use of thrombolytics, some specific in-hospital complications were significantly higher in patients with RBBB than without, RBBB.
- Published
- 2002
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