Knockdown resistance (kdr)-like mutations in the voltage-gated sodium channel of a malaria vector Anopheles stephensi and PCR assays for their detection

<p>Abstract</p> <p>Background</p> <p>Knockdown resistance (<it>kdr</it>) in insects, resulting from mutation(s) in the voltage-gated sodium channel (vgsc) gene is one of the mechanisms of resistance against DDT and pyrethroid-group of insecticides. The most common mutation(s) associated with knockdown resistance in insects, including anophelines, has been reported to be present at residue Leu1014 in the IIS6 transmembrane segment of the vgsc gene. This study reports the presence of two alternative <it>kdr</it>-like mutations, L1014S and L1014F, at this residue in a major malaria vector <it>Anopheles stephensi </it>and describes new PCR assays for their detection.</p> <p>Methods</p> <p>Part of the vgsc (IIS4-S5 linker-to-IIS6 transmembrane segment) of <it>An. stephensi </it>collected from Alwar (Rajasthan, India) was PCR-amplified from genomic DNA, sequenced and analysed for the presence of deduced amino acid substitution(s).</p> <p>Results</p> <p>Analysis of DNA sequences revealed the presence of two alternative non-synonymous point mutations at L1014 residue in the IIS6 transmembrane segment of vgsc, i.e., T>C mutation on the second position and A>T mutation on the third position of the codon, leading to Leu (TTA)-to-Ser (TCA) and -Phe (TTT) amino acid substitutions, respectively. Polymerase chain reaction (PCR) assays were developed for identification of each of these two point mutations. Genotyping of <it>An. stephensi </it>mosquitoes from Alwar by PCR assays revealed the presence of both mutations, with a high frequency of L1014S. The PCR assays developed for detection of the <it>kdr </it>mutations were specific as confirmed by DNA sequencing of PCR-genotyped samples.</p> <p>Conclusions</p> <p>Two alternative <it>kdr-</it>like mutations, L1014S and L1014F, were detected in <it>An. stephensi </it>with a high allelic frequency of L1014S. The occurrence of L1014S is being reported for the first time in <it>An. stephensi</it>. Two specific PCR assays were developed for detection of two <it>kdr</it>-like mutations in <it>An. stephensi</it>.</p

Homotopy Perturbation Method for Solving System of Generalized Abel’s Integral Equations

In this paper, a user friendly algorithm based on the homotopy perturbation method (HPM) is proposed to solve a system of generalized Abel’s integral equations. The stability of the solution under the influence of noise in the input data is analyzed. It is observed that the approximate solutions converge to the exact solutions. Illustrative numerical examples are given to demonstrate the efficiency and simplicity of the proposed method in solving such types of systems of Abel’s integral equations

Variations in palpal ornamentation of Anopheles fluviatilis species T and U (Diptera: Culicidae) and their taxonomic consequence

64-68Anopheles fluviatilis sensu lato James is a highly efficient malaria vector in Indian subcontinent and Iran which is comprised of at least four sibling species provisionally designated as species S, T, U and V. An important morphological characteristic for differentiation of this species complex from other closely related anopheline species complex, the Minimus Complex, is the ratio of length of subapical pale band to dark band intervening apical and subapical pale bands on the maxillary palps of female mosquito. Here, we report variation in the subapical pale band in An. fluviatilis, especially in species U, to the extent that palps of some specimens resemble members of Minimus Complex, inferring that palpal ornamentation may not be reliable characteristics for identification of An. fluviatilis. Taxonomic consequence of such variation is discussed

Genetic evidence for malaria vectors of the Anopheles sundaicus complex in Sri Lanka with morphological characteristics attributed to Anopheles subpictus species B

<p>Abstract</p> <p>Background</p> <p><it>Anopheles subpictus sensu lato</it>, a widespread malaria vector in Asia, is reportedly composed of four sibling species A - D. Mosquitoes morphologically identified as belonging to the Subpictus complex were collected from different locations near the east coast of Sri Lanka, and specific ribosomal DNA sequences determined to validate their taxonomic status.</p> <p>Methods</p> <p><it>Anopheles subpictus s.l</it>. larvae and blood-fed adults were collected from different locations in the Eastern province and their sibling species status was determined based on published morphological characteristics. DNA sequences of the D3 domain of 28 S ribosomal DNA (rDNA) and the internal transcribed spacer -2 (ITS-2) of mosquitoes morphologically identified as <it>An. subpictus </it>sibling species A, B, C and D were determined.</p> <p>Results</p> <p>Phylogenetic analysis based on D3 domain of rDNA resulted in two clades: one clade with mosquitoes identified as <it>An. subpictus </it>species A, C, D and some mosquitoes identified as species B, and another clade with a majority of mosquitoes identified as species B with D3 sequences that were identical to <it>Anopheles sundaicus </it>cytotype D. Analysis of ITS-2 sequences confirmed a close relationship between a majority of mosquitoes identified as <it>An. subpictus </it>B with members of the <it>An. sundaicus </it>complex and others identified as <it>An. subpictus </it>B with <it>An. subpictus s.l</it>.</p> <p>Conclusions</p> <p>The study suggests that published morphological characteristics are not specific enough to identify some members of the Subpictus complex, particularly species B. The sequences of the ITS-2 and D3 domain of rDNA suggest that a majority that were identified morphologically as <it>An. subpictus </it>species B in the east coast of Sri Lanka, and some identified elsewhere in SE Asia as <it>An. subpictus s.l</it>., are in fact members of the Sundaicus complex based on genetic similarity to <it>An. sundaicus s.l</it>. In view of the well-known ability of <it>An. sundaicus s.l</it>. to breed in brackish and fresh water and its proven ability to transmit malaria in coastal areas of many Southeast Asian countries, the present findings have significant implications for malaria control in Sri Lanka and neighbouring countries.</p

Legal Framework for Implementation of Trans-fat Regulations in India

Background: The widespread consumption of trans-fats across the world represents a worrying scenario, as it is directly responsible for coronary heart disease and related mortality. Recognizing its dangers, the WHO has set an agenda to eliminate trans-fats by 2023. In India, the Food Safety And Standards Authority ensures safe and wholesome food consumption. In light of the WHO’s standards for the elimination of trans-fats, the FSSAI recently notified limits of trans-fatty acids to not more than 3% in all fats and oils by January 2021 and 2% by January 2022, as well as a limitation on all food products in which edible oils and fats are ingredients to not contain trans-fatty acids of more than 2% mass of total oils/fats in the product by January 2022. Objective: Given the need to eliminate the consumption of trans-fats, it is necessary to assess the implementation of trans-fat regulations in India in order to determine the current status of enforcement and suggest measures for improvement. Methods: Empirical research was conducted through a questionnaire to analyze India’s current status and difficulties in enforcing trans-fat regulations. Results: Although all states have included compliance of trans-fat regulation in the agenda of the State Surveillance Plan but are facing some implementation challenges such as lack of lab infrastructure, lack of trained manpower, unsupportive FBOs, insufficient budget, lack of testing kits, and excluding proprietary food from compliance with trans-fat regulations. Further, all states have felt the need to develop a guideline/manual to facilitate enforcement of the trans-fat regulations. In light of this, the article has critically analyzed the Legal framework for implementing Trans-fat Regulations in India to identify specific implementation challenges due to scattered regulations and recommend suggestive measures for developing the guidelines/manual to facilitate effective implementation of the said regulation

Hindi Generation from Interlingua

This paper reports our work on generating Hindi sentences from an interlingua representation called Universal Networking Language (UNL). UNL represents knowledge in semantic net like graphs which contain disambiguated words, binary semantic relations, and speech act like attributes associated with the words. Assisted by a semantically rich lexicon, a priority-matrix of syntax plan, and elaborate morphology synthesis rules, we produce fluent Hindi sentences which also meet the adequacy requirement with respect to the reference sentences, and the faithfulness requirement with respect to the semantic graphs. The system has been tested on agricultural corpora, and the system generated sentences were scored by a team of evaluators. The BLEU scores against the reference sentences have been computed. The results show that our system is able to generate slightly flawed but easy to understand sentences that convey most of the meaning. We observe strong correlation between the fluency scores and the BLEU scores, as well as between fluency and the adequacy scores. Since fluency evaluation does not require reference translation, this correlation facilitates large scale evaluation of our system without translating large number of UNL sentences. This system is a step towards machine translation involving Hindi as the target language. Our approach is also adoptable to the generation of other languages, in particular Indian languages

Hypervalent iodine mediated synthesis of 3-substituted-s- triazolo[3,4-a]phthalazines

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Response of nitrogen and sulphur levels on productivity and profitability of QPM hybrid (Zea mays) under dryland condition of Eastern Uttar Pradesh

A field experiments was conducted during, 2009-2010 and 2010-2011 at Varanasi , under dryland condition to assess the growth, yield, quality, nutrient content and economics of QPM hybrids (Zea mays L.) under different nitrogen and sulphur levels. Twenty four treatment combination arranged in split plot design replicated three times with four nitrogen levels control, 50 kg N/ha, 100 kg N/ha and 150 kg N/ha in main plot treatments, two QPM hybrids Shaktiman-2 and Shaktiman-4 and three sulphur levels 15 kg S/ha, 30 kg S/ha and 45 kg S/ha as sub-plot treatments. Significant differences were observed among the treatments for all the parameters studied. Dry matter accumulation (g/plant), cob diameter (cm), test weight, protein content (%), protein yield (q/ha), N, P2O5, K2O and S content in plant was increased significantly as a result of nitrogen and sulphur levels. Application of 150 kg N/ha recorded significantly higher grain yield 43.94% and 43.43% over 0 kg N/ha in 1st and 2nd years, respectively. The highest net return (65.76% and 64.07%) and B: C ratio (39.08% and 38.72%) was recorded under 150 kg N/ha in 1st and 2nd years, respectively over 0 kg N/ha. QPM hybrid, Shaktiman-4 proved significantly higher growth, yield attributes, quality, net return and B: C ratio compared to Shaktiman-2. Shaktiman-4 recorded 3.55% and 2.62% higher grain yield over Shaktiman-2 in 1st and 2nd years, respectively. Application of 45 kg S/ha obtained 10.77% and 10.25% highest grain yield during 1st and 2nd years, respectively over 15 kg S/ha. The highest net return (12.56% and 11.69%) and B: C ratio (3.15% and 3.52%) was recorded under 45 kg S/ha in 1st and 2nd years, respectively over 15 kg S/ha

Recognition of fold- and function-specific sites in the ligand-binding domain of the thyroid hormone receptor-like family

Background: The thyroid hormone receptor-like (THR-like) family is the largest transcription factors family belonging to the nuclear receptor superfamily, which directly binds to DNA and regulates the gene expression and thereby controls various metabolic processes in a ligand-dependent manner. The THR-like family contains receptors THRs, RARs, VDR, PPARs, RORs, Rev-erbs, CAR, PXR, LXRs, and others. THR-like receptors are involved in many aspects of human health, including development, metabolism and homeostasis. Therefore, it is considered an important therapeutic target for various diseases such as osteoporosis, rickets, diabetes, etc. Methods: In this study, we have performed an extensive sequence and structure analysis of the ligand-binding domain (LBD) of the THR-like family spanning multiple taxa. We have use different computational tools (information-theoretic measures; relative entropy) to predict the key residues responsible for fold and functional specificity in the LBD of the THR-like family. The MSA of THR-like LBDs was further used as input in conservation studies and phylogenetic clustering studies. Results: Phylogenetic analysis of the LBD domain of THR-like proteins resulted in the clustering of eight subfamilies based on their sequence homology. The conservation analysis by relative entropy (RE) revealed that structurally important residues are conserved throughout the LBDs in the THR-like family. The multi-harmony conservation analysis further predicted specificity in determining residues in LBDs of THR-like subfamilies. Finally, fold and functional specificity determining residues (residues critical for ligand, DBD and coregulators binding) were mapped on the three-dimensional structure of thyroid hormone receptor protein. We then compiled a list of natural mutations in THR-like LBDs and mapped them along with fold and function-specific mutations. Some of the mutations were found to have a link with severe diseases like hypothyroidism, rickets, obesity, lipodystrophy, epilepsy, etc. Conclusion: Our study identifies fold and function-specific residues in THR-like LBDs. We believe that this study will be useful in exploring the role of these residues in the binding of different drugs, ligands, and protein-protein interaction among partner proteins. So this study might be helpful in the rational design of either ligands or receptors