Distribution of Rare and Noteworthy Zingibers in Mudumalai Tiger Reserve

Abstrac

Assembly and Use of Permanent Secondary Standards for Calibration of Infrared Spectrophotometer for Determination of Isotopic Purity of Nuclear Grade Heavy Water

861-863Infrared (IR) spectrophotometer like any other instrument fur quantitative or qualitative measurement of a property of a sample requires calibration or standardisation with respect to a set of samples of known values of the parameter. For heavy water application, standards made out of nuclear grade heavy water are to be used. Since heavy water is hygroscopic in nature, standards tend to get degraded with time and thus shelf-life of heavy water standards is limited. Therefore, a permanent set of secondary standards assembled using wire mesh or glass plate of known transmittance is found as a better alternative for analysing heavy water, especially on routine basis. The paper describes this methodology

An extraordinary transmission analogue for enhancing microwave antenna performance

The theory of diffraction limit proposed by H.A Bethe limits the total power transfer through a subwavelength hole. Researchers all over the world have gone through different techniques for boosting the transmission through subwavelength holes resulting in the Extraordinary Transmission (EOT) behavior. We examine computationally and experimentally the concept of EOT nature in the microwave range for enhancing radiation performance of a stacked dipole antenna working in the S band. It is shown that the front to back ratio of the antenna is considerably enhanced without affecting the impedance matching performance of the design. The computational analysis based on Finite Difference Time Domain (FDTD) method reveals that the excitation of Fabry-Perot resonant modes on the slots is responsible for performance enhancement

Exploration of Natural Product Repository by Combined Genomics and Metabolomics Profiling of Mangrove-Derived <i>Streptomyces murinus</i> THV12 Strain

Streptomyces, one of the largest genera belonging to the phylum Actinobacteria, contribute to more than 60% of the clinically relevant antibiotics. The present study outlined the genomics and the metabolomics of a mangrove-derived Streptomyces murinus THV12 strain. The Illumina Hiseq 2500 platform-based whole-genome sequencing of the Streptomyces strain generated a consensus sequence of 8,363,247 bp with 107 contigs and 7345 protein-coding genes, which shared significant homology with genes from Streptomyces murinus. The detection of secondary metabolite biosynthetic gene clusters (smBGCs) in the genome performed using the pipeline antiSMASH v6.1.1 revealed that the strain harbored 47 secondary metabolite clusters, which represented 17.9% of the 8.3 Mb genome. The smBGCs belonged to the metabolite categories: PKS, NRPS, ectoine, lassopeptides, lantipeptides, melanin, siderophores, terpenes and other putative products. The strain showed broad-spectrum antimicrobial activity with a inhibition zone of 30 mm against Gram-positive bacteria and Candida albicans. The secondary metabolite profiling of the crude extracts from the fermentation broth of THV12 was performed with the HPLC system coupled with an Orbitrap Exploris120 high-resolution mass spectrometer. As revealed by in silico analysis, compounds such as actinomycin D, pentamycin, desferrioxamine E and cinnabaramide A were detected with MS/MS analysis. Apart from this, compounds belonging to different chemical scaffolds, such as cyclic and linear peptides, bacterial alkaloids, linear polyketides and terpenoids, were also present in the fermentation broth of the strain when cultivated under the OSMAC (One Strain Many Compounds) approach. Thus, the combined strategy of genome mining and metabolomics of the mangrove-derived strain aided in exploring the chemical diversity of BGCs and new chemical entities, which can contribute to drug leads