50 research outputs found

    Formation of Binary & Ternary Chelates of Calmagite with Lanthanides in Presence of Some Amino Polycarboxylic Acids

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    172-173The formation constants of 1:1 and 1:2 binary Ln(III)-calmagite (CLM) and 1:1:1 ternary [Ln(III)-CLM-A] chelates [where Ln(III)=La, Pr, Nd, Gd, Dy and Y; A= iminodiacetic acid (IMDA), hydroxyethyliminodiacetic acid (HIMDA) and nitrilotriacetic acid (NTA)] have been determined pH-metrically in 50% (v/v) aq. methanol medium at 30Β°C and I= 0.1 M (NaClO4). The ligand calmagite coordinates as a secondary ligand in presence of IMDA, HIMDA and NTA with all the metal ions. The order of formation constants of binary as well as ternary chelates is found to be: La Y

    Formation constants of binary & ternary chelates of Ln(III) with maltol & kojic acid in presence of amino carboxylic acids

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    174-175The formation constants of binary and ternary systems involving 3-hydroxy-2-methyl-4-pyrone (HMP) (maltol) and 5-hydroxy-2-hydroxymethyl-4-pyrone (HOMP) (kojic acid), with lanthanide metal ions [La(III), Pr(II), Nd(III), Gd(III), Dy(III) and Y(III)] in the presence of iminodiacetic acid (IMDA), hydroxyethyliminodiacetic acid (HIMDA) and nitrilotriacetic acid (NTA) have been determined in aqueous medium at 30Β°C and ΞΌ = 0.1 M (NaClO4). The order of stabilities of ternary systems is: HMP > HOMP and IMDA > HIMDA > NTA. These are explained in the light of the basi-cities of the Iigands and charge neutralisation

    Caste and identity processes among British Sikhs in the Midlands

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    This article examines the role of caste in the lives and identities of a small sample of young Sikhs in the English Midlands, using social psychological theory. In many academic writings, there is an implicit representation of caste as a negative aspect of South Asian culture and religion, and of caste identification as a means of oppressing vulnerable outgroups. Twenty-three young Sikhs were interviewed, and the qualitative data were analysed using Identity Process Theory. The following themes are discussed: (i) Caste as a Dormant Social Category, (ii) Anchoring the Caste Ingroup to Positive Social Representations, and (iii) Caste as an Inherent or Constructed Aspect of Identity? It is argued that neither caste nor caste-based prejudice appear to be prominent in the lives and identities of our interviewees but that, because caste is an important symbolic aspect of identity which can acquire salient in particular contexts, some Sikhs may wish to maintain this identity though endogamy. What is understood as caste-based prejudice can be better understood in terms of the downward comparison principle in social psychology. The implications for caste legislation are discussed

    Tissue-Specific Transcriptomics of the Exotic Invasive Insect Pest Emerald Ash Borer (Agrilus planipennis)

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    BACKGROUND: The insect midgut and fat body represent major tissue interfaces that deal with several important physiological functions including digestion, detoxification and immune response. The emerald ash borer (Agrilus planipennis), is an exotic invasive insect pest that has killed millions of ash trees (Fraxinus spp.) primarily in the Midwestern United States and Ontario, Canada. However, despite its high impact status little knowledge exists for A. planipennis at the molecular level. METHODOLOGY AND PRINCIPAL FINDINGS: Newer-generation Roche-454 pyrosequencing was used to obtain 126,185 reads for the midgut and 240,848 reads for the fat body, which were assembled into 25,173 and 37,661 high quality expressed sequence tags (ESTs) for the midgut and the fat body of A. planipennis larvae, respectively. Among these ESTs, 36% of the midgut and 38% of the fat body sequences showed similarity to proteins in the GenBank nr database. A high number of the midgut sequences contained chitin-binding peritrophin (248)and trypsin (98) domains; while the fat body sequences showed high occurrence of cytochrome P450s (85) and protein kinase (123) domains. Further, the midgut transcriptome of A. planipennis revealed putative microbial transcripts encoding for cell-wall degrading enzymes such as polygalacturonases and endoglucanases. A significant number of SNPs (137 in midgut and 347 in fat body) and microsatellite loci (317 in midgut and 571 in fat body) were predicted in the A. planipennis transcripts. An initial assessment of cytochrome P450s belonging to various CYP clades revealed distinct expression patterns at the tissue level. CONCLUSIONS AND SIGNIFICANCE: To our knowledge this study is one of the first to illuminate tissue-specific gene expression in an invasive insect of high ecological and economic consequence. These findings will lay the foundation for future gene expression and functional studies in A. planipennis

    Combining Next-Generation Sequencing Strategies for Rapid Molecular Resource Development from an Invasive Aphid Species, Aphis glycines

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    Aphids are one of the most important insect taxa in terms of ecology, evolutionary biology, genetics and genomics, and interactions with endosymbionts. Additionally, many aphids are serious pest species of agricultural and horticultural plants. Recent genetic and genomic research has expanded molecular resources for many aphid species, including the whole genome sequencing of the pea aphid, Acrythosiphon pisum. However, the invasive soybean aphid, Aphis glycines, lacks in any significant molecular resources.Two next-generation sequencing technologies (Roche-454 and Illumina GA-II) were used in a combined approach to develop both transcriptomic and genomic resources, including expressed genes and molecular markers. Over 278 million bp were sequenced among the two methods, resulting in 19,293 transcripts and 56,688 genomic sequences. From this data set, 635 SNPs and 1,382 microsatellite markers were identified. For each sequencing method, different soybean aphid biotypes were used which revealed potential biotype specific markers. In addition, we uncovered 39,822 bp of sequence that were related to the obligatory endosymbiont, Buchnera aphidicola, as well as sequences that suggest the presence of Hamiltonella defensa, a facultative endosymbiont.Molecular resources for an invasive, non-model aphid species were generated. Additionally, the power of next-generation sequencing to uncover endosymbionts was demonstrated. The resources presented here will complement ongoing molecular studies within the Aphididae, including the pea aphid whole genome, lead to better understanding of aphid adaptation and evolution, and help provide novel targets for soybean aphid control

    Transcriptomics of the Bed Bug (Cimex lectularius)

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    BACKGROUND: Bed bugs (Cimex lectularius) are blood-feeding insects poised to become one of the major pests in households throughout the United States. Resistance of C. lectularius to insecticides/pesticides is one factor thought to be involved in its sudden resurgence. Despite its high-impact status, scant knowledge exists at the genomic level for C. lectularius. Hence, we subjected the C. lectularius transcriptome to 454 pyrosequencing in order to identify potential genes involved in pesticide resistance. METHODOLOGY AND PRINCIPAL FINDINGS: Using 454 pyrosequencing, we obtained a total of 216,419 reads with 79,596,412 bp, which were assembled into 35,646 expressed sequence tags (3902 contigs and 31744 singletons). Nearly 85.9% of the C. lectularius sequences showed similarity to insect sequences, but 44.8% of the deduced proteins of C. lectularius did not show similarity with sequences in the GenBank non-redundant database. KEGG analysis revealed putative members of several detoxification pathways involved in pesticide resistance. Lamprin domains, Protein Kinase domains, Protein Tyrosine Kinase domains and cytochrome P450 domains were among the top Pfam domains predicted for the C. lectularius sequences. An initial assessment of putative defense genes, including a cytochrome P450 and a glutathione-S-transferase (GST), revealed high transcript levels for the cytochrome P450 (CYP9) in pesticide-exposed versus pesticide-susceptible C. lectularius populations. A significant number of single nucleotide polymorphisms (296) and microsatellite loci (370) were predicted in the C. lectularius sequences. Furthermore, 59 putative sequences of Wolbachia were retrieved from the database. CONCLUSIONS: To our knowledge this is the first study to elucidate the genetic makeup of C. lectularius. This pyrosequencing effort provides clues to the identification of potential detoxification genes involved in pesticide resistance of C. lectularius and lays the foundation for future functional genomics studies

    Equilibrium studies on mixed ligand complexes of lanthanides with some schiff bases and polycarboxylic acids

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    192-194Equilibrium studies have been done on the mixed ligand complexes of Ln(III) with ligands L and A where L = N-(salicylidene)-1H-2-benzimidazolylmethylamine (SBMA), N-(3-chlorosalicylidene)-1H-2-benzimidazolylmethylamine(SBMA), N-(3-methoxysalicylidene)1H-2-benzimidazolylmethylamine (MeO-SBMA); A = iminodiacetic acid (IMDA), hydroxyethyliminodiacetic acid (HIMDA), nitrilotriacetic acid (NTA) and Ln(III) = Pr(III), Nd(III), Dy(III), Gd(III), Y(III). Formation constants of binary 1:1:1 (ML), 1:2 (ML2) and ternary 1:1:1 (MAL) complexes have been determined potentiometrically at 30Β°C in 60% (v/v) aqueous methanol at I = 0.1Β M (NaClO4). In these systems, the ligand L acts as a secondary ligand in the presence of A
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