588 research outputs found

    Distribution of mosquito larvae in rice field habitats: A spatial scale analysis in semi-field condition

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    The distribution of the mosquito larvae in the breeding habitats varies at the spatial scale depending on the availability of the resources and the predators. This proposition was assessed through the observation of the spatial distribution of Culex larvae (Culex tritaeniorhynchus) in artificially constructed rice field habitats. Using a binomial generalized linear model with logit link, the disparity in the abundance of the larvae was evaluated to justify the effects of light (light vs shade), vertical (surface vs bottom), and horizontal (wall vs center) distribution as explanatory variables. Under light availability, the spatial occupancy of the mosquito larvae was higher in the center than in the walls of the mesocosms. However, the larval orientation was higher on the surface than at the bottom of the mesocosms in all instances. In comparison to open spaces, the larval aggregation was higher in the presence of the floating vegetations like Azolla and Lemna, indicating that the habitat heterogeneity of the mesocosms influenced the distribution of the mosquito larvae in the available spaces. A reduction in the larval aggregation pattern in the spaces was observed in the presence of the predator (Anisops sp.) reflecting the possible evasion tactics of the mosquito larvae. The observations suggest that the mosquito larvae may utilize the vegetation in the rice field habitats quite effectively and occupy empty spaces of predators. The results may be considered as a prototype of the prospective localization of the mosquito larvae in the rice fields and help to frame the strategies of spraying the biopesticides to achieve optimal efficacy in mosquito regulation

    Vulnerability of the mosquito larvae to the guppies (Poecilia reticulata) in the presence of alternative preys

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    Background & objectives: The predatory potential of the larvivorous fishes can be affected by the presence of alternative preys. In the present study the predation pattern of the sewage dwelling Poecilia reticulata (Peters 1872) on the larvae of Culex quinquefasciatus Say 1823 (Diptera: Culicidae) was evaluated in the presence of alternative preys. Methods: The predation of Cx. quinquefasciatus larvae by different size groups of P. reticulata fishes was evaluated. In addition to this, the niche breadth (N) and diet breadth (B) were measured following Manly’s selectivity index (Si) as an indicator of variation of such predation pattern in the presence of alternative prey types, like chironomid larvae and tubificid worms.Results: The consumption of IV instar Cx. quinquefasciatus larvae by individual P. reticulata ranged between 65 and 84 in a 3 h feeding period and varied with the size of fish (F2, 33 = 34.91; p<0.001). The selectivity coefficient revealed a significantly low preference for the Cx. quinquefasciatus larvae (0.16, CL: 0.05 – 0.27; p< 0.05) compared to the chironomid larvae and tubificid worms, when all the three prey types were present. The niche breadth (N) and diet breadth (B) ranged from 0.77 to 0.92 and 0.69 to 0.93, respectively. The total consumption of all the prey types varied with the predator density, but the selectivity index for the mosquito larvae was significantly low in all the instances.Interpretation & conclusion: P. reticulata can consume a good number of mosquito larvae, with the consumption rate varying with the body size. P. reticulata fishes exhibit low preference for mosquito larvae as prey in the presence of alternative controphic preys like chironomid larvae and tubificid worms. Though establishment and sustenance of P. reticulata in new habitats will be favoured by the presence of alternative preys, but vulnerability of mosquito larvae may be reduced with availability of multiple preys in natural conditions

    Correspondence of butterfly and host plant diversity: Foundation for habitat restoration and conservation

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    At a spatial scale, the diversity of butterflies varies with numerous factors including the availability of the host plant species. In parity with this proposition, the correspondence of diversity of butterfly and plant in the background&nbsp;of the urban–rural gradient was evaluated using Kolkata, India, as a model study area. The results reveal significant positive correlation between the diversity of butterflies and the plants, with the different values for&nbsp;the suburban, rural, and urban areas. Identification of the butterfly loads for the plants in the respective areas can be useful in enhancing the conservation of the butterflies through enhanced plantation of the concerned plant species. Alternatively, the disclosure of the generalist and specialist pattern of the plant species preference by the butterflies may be useful in enhancing the population of the respective species in the concerned&nbsp;areas. The conservation strategy for butterfly species may be refined through the use of both or any one of the&nbsp;quantitative assessment of the butterfly–plant links in the urban–rural gradient in Kolkata, India, and similar&nbsp;places in the world

    Community structure of Coleoptera in Bethuadahari Wildlife Sanctuary, West Bengal, India

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    We focused on the coleopteran species assemblage in a tropical deciduous forest in the Bethuadahari Wildlife Sanctuary, West Bengal, India. During a 2-year survey, we collected 56 species belonging to 13 families of Coleoptera, in varying relative abundance. Among the species, 15 belong to the family Chrysomelidae, nine to the Staphyllinidae, and four to the Coccinellidae. Our results substantiate the importance of the Bethuadahari Wildlife Sanctuary for the conservation of coleopteran insects

    Knowledge-based Analogical Reasoning in Neuro-symbolic Latent Spaces

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    Analogical Reasoning problems challenge both connectionist and symbolic AI systems as these entail a combination of background knowledge, reasoning and pattern recognition. While symbolic systems ingest explicit domain knowledge and perform deductive reasoning, they are sensitive to noise and require inputs be mapped to preset symbolic features. Connectionist systems on the other hand can directly ingest rich input spaces such as images, text or speech and recognize pattern even with noisy inputs. However, connectionist models struggle to include explicit domain knowledge for deductive reasoning. In this paper, we propose a framework that combines the pattern recognition abilities of neural networks with symbolic reasoning and background knowledge for solving a class of Analogical Reasoning problems where the set of attributes and possible relations across them are known apriori. We take inspiration from the 'neural algorithmic reasoning' approach [DeepMind 2020] and use problem-specific background knowledge by (i) learning a distributed representation based on a symbolic model of the problem (ii) training neural-network transformations reflective of the relations involved in the problem and finally (iii) training a neural network encoder from images to the distributed representation in (i). These three elements enable us to perform search-based reasoning using neural networks as elementary functions manipulating distributed representations. We test this on visual analogy problems in RAVENs Progressive Matrices, and achieve accuracy competitive with human performance and, in certain cases, superior to initial end-to-end neural-network based approaches. While recent neural models trained at scale yield SOTA, our novel neuro-symbolic reasoning approach is a promising direction for this problem, and is arguably more general, especially for problems where domain knowledge is available.Comment: 13 pages, 4 figures, Accepted at 16th International Workshop on Neural-Symbolic Learning and Reasoning as part of the 2nd International Joint Conference on Learning & Reasoning (IJCLR 2022

    Myxoid liposarcoma presenting like a cystic neck swelling

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    Soft tissue sarcomas are rare and unusual neoplasm’s, accounting for approximately 1% of adult human cancers and 15% of pediatric malignancies. Most liposarcomas occur in deep soft tissues of the extremities and retroperitoneum; only a very small percentage (as low as 2%) occurs in the head and neck. Here we present a case of a 48yr old male with a painless mass in the neck clinically presenting as a cystic swelling. The CT neck was suggestive of cystic lesion in the neck representing benign cystic lesion. The swelling was excised and sent for histopathology which was suggestive of myxoid liposarcoma. The patient was planned for wide excision of the edges and scar and adjuvant chemo and radio therapy

    A randomized prospective study to compare the efficacy and safety of budesonide plus formoterol and tiotropium plus formoterol in patients having mild to moderate chronic obstructive pulmonary disease

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    Background: Chronic obstructive pulmonary disease (COPD) is a leading respiratory illness affecting the quality of lives around the world. The present study aims to compare the efficacy and safety of combination of inhaled corticosteroid (ICS) and long acting β2 agonist (LABA) with long acting β2 agonist and long acting muscarinic antagonist (LAMA) in treatment of mild to moderate COPD in a tertiary care hospital.Methods: Total 132 patients with COPD were recruited on the basis of inclusion and exclusion criteria for 8 weeks study from outpatient clinic. A complete pulmonary examination including spirometry examination was done to rule out severe and very severe forms of COPD. Spirometry was performed at the time of recruitment for evaluation of forced expiratory volume in one second (FEV1) and measurement of SpO2 at the time of recruitment at 2 weeks and 8 weeks. Appropriate statistical methods were used to compare the qualitative and quantitative primary and secondary efficacy end points, p value <0.05 was considered significant.Results: On analysis, there was a significant difference (p<0.05) was observed in FEV1 and SpO2 from baseline in ICS plus LABA group (n=66). A similarly significant difference (p<0.05) was observed in LABA and LAMA group (n=66). On comparison between ICS plus LABA and LABA plus LAMA no significant difference in FEV1 and SpO2 was observed between the two groups.  More adverse drug reactions were observed in ICS plus LABA group than LAMA plus LABA group.Conclusions: Combination of ICS and LABA combination is as effective as combination of LABA and LAMA in patients having mild to moderate COPD. However, LABA and LAMA combination is preferable because it is associated with fewer side effects
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