Synthesis of benzofuran based 1,3,5-substituted pyrazole derivatives: As a new class of potent antioxidants and antimicrobials-A novel accost to amend biocompatibility

In search for a new antioxidant and antimicrobial agent with improved potency, we synthesized a series of benzofuran based 1,3,5-substituted pyrazole analogues (5a-l) in five step reaction. Initially, o-alkyl derivative of salicyaldehyde readily furnish corresponding 2-acetyl benzofuran 2 in good yield, on treatment with 1,8-diaza bicyclo5.4.0]undec-7-ene (DBU) in the presence of molecular sieves. Further, aldol condensation with vanillin, Claisen-Schmidt condensation reaction with hydrazine hydrate followed by coupling of substituted anilines afforded target compounds. The structures of newly synthesized compounds were confirmed by IR, H-1 NMR, C-13 NMR, mass, elemental analysis and further screened for their antioxidant and antimicrobial activities. Among the tested compounds 5d and 5f exhibited good antioxidant property with 50% inhibitory concentration higher than that of reference while compounds 5h and 5l exhibited good antimicrobial activity at concentration 1.0 and 0.5 mg/mL compared with standard, streptomycin and fluconazole respectively. (C) 2012 Elsevier Ltd. All rights reserved.

A new species of Raorchestes (Amphibia: Anura: Rhacophoridae) from mid-elevation evergreen forests of the southern Western Ghats, India

A new species of the shrub frog genus Raorchestes Biju, Souche, Dubois, Dutta and Bossuyt is described as Raorchestes kakachi sp. nov. from Agastyamalai hill region in the southern Western Ghats, India. The small sized Raorchestes (male: 24.7–25.8 mm, n = 3 and female: 24.3–34.1 mm, n = 3) is distinguished from all other known congeners by the following suite of characters. Snout oval in dorsal view; tympanum indistinct; head wider than long; moderate webbing in feet; colour on dorsum varying from ivory to brown, blotches of dark brown on flanks, brown mottling on throat reducing towards vent; inner and outer surface of thigh, inner surface of shank and inner surface of tarsus with a distinct dark brown horizontal band which extends upto first three toes on upper surface. A detailed description, advertisement call features, ecology, natural history notes and comparison with closely related species are provided for the new species.

Phospholipid Mediated Activation of Calcium Dependent Protein Kinase 1 (CaCDPK1) from Chickpea: A New Paradigm of Regulation

Phospholipids, the major structural components of membranes, can also have functions in regulating signaling pathways in plants under biotic and abiotic stress. The effects of adding phospholipids on the activity of stress-induced calcium dependent protein kinase (CaCDPK1) from chickpea are reported here. Both autophosphorylation as well as phosphorylation of the added substrate were enhanced specifically by phosphatidylcholine and to a lesser extent by phosphatidic acid, but not by phosphatidylethanolamine. Diacylgylerol, the neutral lipid known to activate mammalian PKC, stimulated CaCDPK1 but at higher concentrations. Increase in V-max of the enzyme activity by these phospholipids significantly decreased the K-m indicating that phospholipids enhance the affinity towards its substrate. In the absence of calcium, addition of phospholipids had no effect on the negligible activity of the enzyme. Intrinsic fluorescence intensity of the CaCDPK1 protein was quenched on adding PA and PC. Higher binding affinity was found with PC (K-1/2 = 114 nM) compared to PA (K-1/2 = 335 nM). We also found that the concentration of PA increased in chickpea plants under salt stress. The stimulation by PA and PC suggests regulation of CaCDPK1 by these phospholipids during stress response.

Development of a New Generation of Vectors for Gene Expression, Gene Replacement, and Protein-Protein Interaction Studies in Mycobacteria

Escherichia coli-mycobacterium shuttle vectors are important tools for gene expression and gene replacement in mycobacteria. However, most of the currently available vectors are limited in their use because of the lack of extended multiple cloning sites (MCSs) and convenience of appending an epitope tag(s) to the cloned open reading frames (ORFs). Here we report a new series of vectors that allow for the constitutive and regulatable expression of proteins, appended with peptide tag sequences at their N and C termini, respectively. The applicability of these vectors is demonstrated by the constitutive and induced expression of the Mycobacterium tuberculosis pknK gene, coding for protein kinase K, a serine-threonine protein kinase. Furthermore, a suicide plasmid with expanded MCS for creating gene replacements, a plasmid for chromosomal integrations at the commonly used L5 attB site, and a hypoxia-responsive vector, for expression of a gene(s) under hypoxic conditions that mimic latency, have also been created. Additionally, we have created a vector for the coexpression of two proteins controlled by two independent promoters, with each protein being in fusion with a different tag. The shuttle vectors developed in the present study are excellent tools for the analysis of gene function in mycobacteria and are a valuable addition to the existing repertoire of vectors for mycobacterial research.

A finite-rate-of-innovation signal sampling perspective of the source-filter model of speech production

We consider the speech production mechanism and the asso- ciated linear source-filter model. For voiced speech sounds in particular, the source/glottal excitation is modeled as a stream of impulses and the filter as a cascade of second-order resonators. We show that the process of sampling speech signals can be modeled as filtering a stream of Dirac impulses (a model for the excitation) with a kernel function (the vocal tract response),and then sampling uniformly. We show that the problem of esti- mating the excitation is equivalent to the problem of recovering a stream of Dirac impulses from samples of a filtered version. We present associated algorithms based on the annihilating filter and also make a comparison with the classical linear prediction technique, which is well known in speech analysis. Results on synthesized as well as natural speech data are presented.

A new species of Duttaphrynus (Anura : Bufonidae) from Northeast India

A new species of montane toad Duttaphrynus is described from Nagaland state of Northeast India. The new species is diagnosable based on following combination of characters: absence of preorbital, postorbital and orbitotympanic ridges, elongated and broad parotid gland, first finger longer than second and presence of a mid-dorsal line. The tympanum is hidden under a skin fold (in male) or absent (in female). The species is compared with its congers from India and Indo-China. We propose to consider Duttaphrynus wokhaensis as junior synonym of Duttaphrynus melanostictus.

A multichannel sampling method for 2-D finite-rate-of-innovation signals

We address the problem of sampling and reconstruction of two-dimensional (2-D) finite-rate-of-innovation (FRI) signals. We propose a three-channel sampling method for efficiently solving the problem. We consider the sampling of a stream of 2-D Dirac impulses and a sum of 2-D unit-step functions. We propose a 2-D causal exponential function as the sampling kernel. By causality in 2-D, we mean that the function has its support restricted to the first quadrant. The advantage of using a multichannel sampling method with causal exponential sampling kernel is that standard annihilating filter or root-finding algorithms are not required. Further, the proposed method has inexpensive hardware implementation and is numerically stable as the number of Dirac impulses increases.

The first teresomatan caecilian (Amphibia: Gymnophiona) from the Eastern Ghats of India-a new species of Gegeneophis Peters, 1880

A new species of caecilian amphibian, Gegeneophis orientalis sp. nov., is described based on a series of nine specimens from high elevation (ca. 1,200 m) habitats in the Eastern Ghats in the states of Andhra Pradesh and Odisha, India. This species differs from all other congeners in having only bicuspid teeth in the outer as well as inner rows. The new species is the first caecilian reported from the state of Odisha, the first teresomatan caecilian from the Eastern Ghats, and is the only Indian indotyphlid known from outside the Western Ghats region.

Two new species of Brachystelma Sims (Apocynaceae: Asclepiadoideae-Ceropegieae) from the Western Ghats of India

Two new species of Brachystelma: B. mahajanii Kambale & S. R. Yadav from Ebbanad, Nilgiri District, Tamil Nadu and B. vartakii Kambale & S. R. Yadav from Periya, Kasargod District, Kerala are described and illustrated.

Mud-packing frog: A novel breeding behaviour and parental care in a stream dwelling new species of Nyctibatrachus (Amphibia, Anura, Nyctibatrachidae)

Reproductive modes are diverse and unique in anurans. Selective pressures of evolution, ecology and environment are attributed to such diverse reproductive modes. Globally forty different reproductive modes in anurans have been described to date. The genus Nyctibatrachus has been recently revised and belongs to an ancient lineage of frog families in the Western Ghats of India. Species of this genus are known to exhibit mountain associated clade endemism and novel breeding behaviours. The purpose of this study is to present unique reproductive behaviour, oviposition and parental care in a new species Nyctibatrachus kumbara sp. nov. which is described in the paper. Nyctibatrachus kumbara sp. nov. is a medium sized stream dwelling frog. It is distinct from the congeners based on a suite of morphological characters and substantially divergent in DNA sequences of the mitochondrial 16S rRNA gene. Males exhibit parental care by mud packing the egg clutch. Such parental care has so far not been described from any other frog species worldwide. Besides this, we emphasize that three co-occurring congeneric species of Nyctibatrachus, namely N. jog, N. kempholeyensis and Nyctibatrachus kumbara sp. nov. from the study site differ in breeding behaviour, which could represent a case of reproductive character displacement. These three species are distinct in their size, call pattern, reproductive behaviour, maximum number of eggs in a clutch, oviposition and parental care, which was evident from the statistical analysis. The study throws light on the reproductive behaviour of Nyctibatrachus kumbara sp. nov. and associated species to understand the evolution and adaptation of reproductive modes of anurans in general, and Nyctibatrachus in particular from the Western Ghats.

Lineage delimitation and description of nine new species of bush frogs (Anura: Raorchestes, Rhacophoridae) from the Western Ghats Escarpment

Bush frogs of the genus Raorchestes are distributed mainly in the Western Ghats Escarpment of Peninsular India. The inventory of species in this genus is incomplete and there is ambiguity in the systematic status of species recognized by morphological criteria. To address the dual problem of taxon sampling and systematic uncertainty in bush frogs, we used a large-scale spatial sampling design, explicitly incorporating the geographic and ecological heterogeneity of the Western Ghats. We then used a hierarchical multi-criteria approach by combining mitochondrial phylogeny, genetic distance, geographic range, morphology and advertisement call to delimit bush frog lineages. Our analyses revealed the existence of a large number of new lineages with varying levels of genetic divergence. Here, we provide diagnoses and descriptions for nine lineages that exhibit divergence across multiple axes. The discovery of new lineages that exhibit high divergence across wide ranges of elevation and across the major massifs highlights the large gaps in historical sampling. These discoveries underscore the significance of addressing inadequate knowledge of species distribution, namely the ``Wallacean shortfall'', in addressing the problem of taxon sampling and unknown diversity in tropical hotspots. A biogeographically informed sampling and analytical approach was critical in detecting and delineating lineages in a consistent manner across the genus. Through increased taxon sampling, we were also able to discern a number of well-supported sub-clades that were either unresolved or absent in earlier phylogenetic reconstructions and identify a number of shallow divergent lineages which require further examination for assessment of their taxonomic status.

New insights of superoxide dismutase inhibition of pyrogallol autoxidation

Autoxidation of pyrogallol in alkaline medium is characterized by increases in oxygen consumption, absorbance at 440 nm, and absorbance at 600 nm. The primary products are H2O2 by reduction of O-2 and pyrogallol-ortho-quinone by oxidation of pyrogallol. About 20 % of the consumed oxygen was used for ring opening leading to the bicyclic product, purpurogallin-quinone (PPQ). The absorbance peak at 440 nm representing the quinone end-products increased throughout at a constant rate. Prolonged incubation of pyrogallol in alkali yielded a product with ESR signal. In contrast the absorbance peak at 600 nm increased to a maximum and then declined after oxygen consumption ceased. This represents quinhydrone charge-transfer complexes as similar peak instantly appeared on mixing pyrogallol with benzoquinones, and these were ESR-silent. Superoxide dismutase inhibition of pyrogallol autoxidation spared the substrates, pyrogallol, and oxygen, indicating that an early step is the target. The SOD concentration-dependent extent of decrease in the autoxidation rate remained the same regardless of higher control rates at pyrogallol concentrations above 0.2 mM. This gave the clue that SOD is catalyzing a reaction that annuls the forward electron transfer step that produces superoxide and pyrogallol-semiquinone, both oxygen radicals. By dismutating these oxygen radicals, an action it is known for, SOD can reverse autoxidation, echoing the reported proposal of superoxide:semiquinone oxidoreductase activity for SOD. The following insights emerged out of these studies. The end-product of pyrogallol autoxidation is PPQ, and not purpurogallin. The quinone products instantly form quinhydrone complexes. These decompose into undefined humic acid-like complexes as late products after cessation of oxygen consumption. SOD catalyzes reversal of autoxidation manifesting as its inhibition. SOD saves catechols from autoxidation and extends their bioavailability.

A new class of high strength high temperature Cobalt based gamma-gamma ` Co-Mo-Al alloys stabilized with Ta addition

The present paper reports a new class of Co based superalloys that has gamma-gamma' microstructure and exhibits much lower density compared to other commercially available Co superalloys including Co-Al-W based alloys. The basic composition is Co-10Al-5Mo (at%) with addition of 2 at% Ta for stabilization of gamma' phase. The gamma-gamma' microstructure evolves through solutionising and aging treatment. Using first principles calculations, we observe that Ta plays a crucial role in stabilizing gamma' phase. By addition of Ta in the basic stoichiometric composition Co-3(Al, Mo), the enthalpy of formation (Delta H-f) of L1(2) structure (gamma' phase) becomes more negative in comparison to DO19 structure. The All of the L12 structure becomes further more negative by the occupancy of Ni and Ti atoms in the lattice suggesting an increase in the stability of the gamma' precipitates. Among large number of alloys studied experimentally, the paper presents results of detailed investigations on Co-10Al-5Mo-2Ta, Co-30Ni-10Al-5Mo-2Ta and Co-30Ni-10Al-5Mo-2Ta-2Ti. To evaluate the role alloying elements, atom probe tomography investigations were carried out to obtain partition coefficients for the constituent elements. The results show strong partitioning of Ni, Al, Ta and Ti in ordered gamma' precipitates. 2015 Acta Materialia Inc. Published by Elsevier Ltd. All rights reserved.

Na2.44Mn1.79(SO4)(3): a new member of the alluaudite family of insertion compounds for sodium ion batteries

Sodium-ion batteries have been extensively pursued as economic alternatives to lithium-ion batteries. Investigating the polyanion chemistry, alluaudite structured Na2Fe2II(SO4)(3) has been recently discovered as a 3.8 V positive electrode material (Barpanda et al., Nature Commun., 5: 4358, 2014). Registering the highest ever Fe-III/Fe-II redox potential (vs. Na/Na+) and formidable energy density, it has opened up a new polyanion family for sodium batteries. Exploring the alluaudite family, here we report isotypical Na2+2xMn2-xII(SO4)(3) (x = 0.22) as a novel high-voltage cathode material for the first time. Following low-temperature (ca. 350 degrees C) solid-state synthesis, the structure of this new alluaudite compound has been solved adopting a monoclinic framework (s.g. C2/c) showing antiferromagnetic ordering at 3.4 K. Synergising experimental and ab initio DFT investigation, Na2+2xMn2-xII(SO4)(3) has been found to be a potential high-voltage (ca. 4.4 V) cathode material for sodium batteries.