Geochemistry and Petrography of Pyroxenites from Mettupalaiyam Ultramafic Complex, Tamil Nadu

The Mettupalaiyam ultramafic complex (MUC) in Tamil Nadu is a major lithological association consisting mostly of Pyroxenites, Peridotite, Gabbro, Anorthosite gabbro in a predominantly gneissic grantite-granite terrain. Pyroxenite occurs as thin lenses and bands, at times attaining moderate thickness. Major, Trace and rear earth element geochemistry and petrography of  pyroxenites collected from well exposed outcrops near Thenkalmalai areas of this complex are presented in this paper and their Petrogenetic significance is discussed.The geochemical signatures of the pyroxenites show a significant variation in major and trace element concentration. The pyroxenites show SiO2 composition ranging from 49.6-55.5%, Al2O3 from 6-13.6%, MgO from 3.6-14.3%, CaO from 8.4-15.5% and TiO2 from 0.24-1.7%. Bulk composition/whole rock analyses indicate that the magma type is tholeiitic but trending towards a calc-alkaline. The pyroxenites are poor in incompatible and high field strength (HFS) elements like Rb, Sr, Hf, and Ta. Total rare earth element (∑REE) content varies in a limited range and exhibits limited REE fractionation in both LREE and HREE. The pyroxenite sample shows Negative Eu-anomalies with slight enrichment of HREE. Primitive mantle normalized multi-element spider grams suggest that the melt parental to these pyroxenites was derived from a mantle source enriched in several trace trace elements

GREEN BIOSYNTHESIS OF MAGNETIC IRON OXIDE NANOPARTICLES OF VITEX NEGUNDO AQUEOUS EXTRACT

Objective: The green synthesis of magnetic iron oxide nanoparticles is a convenient, economical, rapid and eco-friendly method compared to physical and chemical synthesis methods.Methods: In the present study iron oxide nanoparticles synthesized by Vitex negundo leaves extract.Results: The formation of iron oxide nanoparticles was confirmed by the colour change and further characterized by UV-Visible Spectroscopy and XRD. The morphology and the size of nanoparticles were analyzed by SEM and HR-TEM analysis.Conclusion: On the basis of this research work, green synthesized iron oxide nanoparticles can be a good source for alternative therapy for human diseases

CARICA PAPAYA MEDIATED GREEN SYNTHESIZED SILVER NANOPARTICLES

Objective: The present study was designed to biosynthesize NPs from leaves to study the reducing Ag+ions and stabilizing the particles and confirm AgNP synthesis by using various spectroscopy and microscopic methods.Methods: Bio-inspired AgNPs were rapidly synthesized at room temperature using fresh aqueous leaf extract of Carica papaya. A green and low-cost synthesis was effective in the formation of stable crystalline NPs in the solution. Amine, alkene and alkyl halides groups present in the Carica papaya leaf extract functioned as reducing as well as a stabilizing agent to produce shape controlled AgNPs.Results: SPR confirmed the formation of AgNPs in UV-Visible spectra at 445.7 nm. The XRD result also showed the presence of elemental Ag+as a crystalline nature. Study the functional groups responsible for the bio reduction of Ag+. HE-TEM and FE-SEM with EDX image showed spherical crystalline AgNPs.Conclusion: Hence, the plant-based bio AgNPs could be used in biomedical applications

Field characteristics and geochemistry of pyroxenite and gabbro from Odhimalai and Thenkalmalai hillocks of Bhavani ultramafic complex- South India

The present study includes documentation of detailed geological field characteristics, petrography and geochemistry of mafic and ultramafic rocks associated with Odhimalai and Thenkalmalai hills of Bhavani complex. The lithologies well exposed in these two hillocks including Dunite, Pyroxenite, Gabbro, displaying layered arrangement comprising (from basement upwards) dunite, peridotite, pyroxenite and anorthosite-gabbro.The geochemical signatures of the gabbro and pyroxenites show a significant variation in major and trace element concentration. The pyroxenites show SiO2 composition ranging from 49.6-55.5%, Al2O3 from 6-13.6%, MgO from 3.6-14.3%, CaO from 8.4-15.5% and TiO2 from 0.24-1.7% while average composition of SiO2, Al2O3, MgO, CaO and TiO2 in gabbro varies (in %) from 49.9-58, 9.4-13, 7.4-13.1, 9-13.4 and 0.26-0.54 respectively.ÂÂ

Bioactive potential of selected actinobacterial strains against Mycobacterium tuberculosis and other clinical pathogens

1307-1311Marine actinobacteria produces diverse array of metabolites with novel chemical structures with potential bioactivities. Exploring the understudied ecosystems may increase the chance of getting novel actinobacteria and new metabolites.The present study explores the bioactive potential of actinobacteria isolated from the marine ecosystem of Andaman and Nicobar Islands, Bay of Bengal, against Mycobacterium tuberculosis and other clinical pathogens. The crude extracts from 15 marine actinobacterial strains were produced through agar surface fermentation using YEME agar and extracted using ethyl acetate. The crude extracts were tested against the standard strain M. tuberculosis H37Rv, clinical drug sensitive M. tuberculosis, and MDR M. tuberculosis strains by luciferase reporter phage (LRP) assay at 500 µg/ml concentration. The anti-microbial activity against other clinical pathogens, namely, Staphylococcus aureus, Escherichia coli, Salmonella paratyphi, Klebsiellapneumoniae, Pseudomonas aeruginosa, Candida albicans, and Cryptococcusneoformans and non-tubercular mycobacteria, M. smegmatis was studied by agar plug method. Among the 15 extracts that were tested for anti-tubercular activity, the crude ethyl acetate extract of the 14 actinobacterial strains showed anti-tubercular activity against at least one of the three M. tuberculosis strains. Exceptionally, the ethyl acetate extract of strain SACC 168 inhibited all three M. tuberculosis strains tested. In anti-microbial screening, the crude extracts of eight strains showed anti-microbial activity including six strains, which were active against the non-tuberculous mycobacteria. Further purification and characterization of the active molecule from the potential extracts will pave way for the potential natural product candidate for tuberculosis and other microbial infections

Infestation of rhizocepalan barnacle in the Blue swimmer crab

The parasitic rhizocephalan barnacle, Sacculina spp. were observed in the live Blue swimmer crab, Portunus pelagicus while collecting broodstock for crab seed production. Rhizocephalans have been reported from different aquatic habitat like the deep ocean to pelagic, intertidal, brackish water habitat and a few species occur in freshwater also

Larviculture and seed production of the silver pompano, Trachinotus blochii (Lacepede, 1801) for the first time in India

Larviculture and seed production protocols for the silver pompano Trachinotus blochii, which is one of the promising finfish species for brackishwater and marine aquaculture was developed based on six trials for the first time in India. The newly hatched larvae were stocked at a density of 20 larvae l-1 in 2 t FRP tanks with 1.5 t of seawater. Green water technique was employed during larviculture upto the weaning period. Enriched S-type rotifers were fed at a density of 10-12 nos. ml-1 until 3 day post hatch (dph) and the enriched L-type rotifers were given at a density of 6-8 nos. ml-1 from 7 dph and thereafter with enriched Artemia at a density of 3-5 nos. ml-1. Weaning started from 15 dph and by 20-25 dph metamorphosis was completed. The survival on completion of metamorphosis ranged from 10-15% and the specific growth rate in terms of length (mm) was 8% per day. The larval morphology and growth pattern are also described

Impact of increase in temperature and light intensity on development and metamorphosis of hatchery reared silver pompano Trachinotus blochii (Lacepede, 1801) larvae

The largehead ribbonfish, Trichiurus lepturus Linnaeus, 1758 forms a major fishery along north-west coast of India comprising the two coastal states of Gujarat and Maharashtra. Diet composition was analysed for five years (2010-2014) to understand shifts if any in the prey items. Seasonal changes in the prey items were studied for three years (2012-2014) to explore the temporal dynamics of prey availability in the ecosystem and in largehead ribbonfish guts. Feeding indices viz., Stomach fullness index (SFI), empty stomach ratio (ESR), gastrosomatic index (GaSI) and relative gut length (RLG) explained the feeding behaviour, seasonal dynamics and ontogenetic shifts in prey items. The Vacuity Index (VI) was estimated as 37.56%, indicating that T. lepturus is a carnivore and relatively edacious. Diet of T. lepturus comprised of fishes (47.16%), crustaceans (45.22%), molluscs (4.33%) and miscellaneous items (3.28%). Acetes sp. was the most dominant prey item during the study period. Feeding intensity was found to be high during the post-monsoon months which coincided with the period of gonadal maturation of the fish. Significant variations (p<0.05) were seen in the feeding indices during different months, different sizes and between sexes due to the availability of prey items, physiological changes and ontogenetic shifts. A detailed knowledge on diet composition, temporal dynamics in diet patterns and feeding indices can reveal the trophic interaction of prey-predator, resource abundance and fluctuations which are important inputs in ecology-based fishery management models/tools

Role of a Putative Alkylhydroperoxidase Rv2159c in the Oxidative Stress Response and Virulence of Mycobacterium tuberculosis

Mycobacterium tuberculosis, which causes tuberculosis, is one of the leading infectious agents worldwide with a high rate of mortality. Following aerosol inhalation, M. tuberculosis primarily infects the alveolar macrophages, which results in a host immune response that gradually activates various antimicrobial mechanisms, including the production of reactive oxygen species (ROS), within the phagocytes to neutralize the bacteria. OxyR is the master regulator of oxidative stress response in several bacterial species. However, due to the absence of a functional oxyR locus in M. tuberculosis, the peroxidase stress is controlled by alkylhydroperoxidases. M. tuberculosis expresses alkylhydroperoxide reductase to counteract the toxic effects of ROS. In the current study, we report the functional characterization of an orthologue of alkylhydroperoxidase family member, Rv2159c, a conserved protein with putative peroxidase activity, during stress response and virulence of M. tuberculosis. We generated a gene knockout mutant of M. tuberculosis Rv2159c (MtbΔ2159) by specialized transduction. The MtbΔ2159 was sensitive to oxidative stress and exposure to toxic transition metals. In a human monocyte (THP-1) cell infection model, MtbΔ2159 showed reduced uptake and intracellular survival and increased expression of pro-inflammatory molecules, including IL-1β, IP-10, and MIP-1α, compared to the wild type M. tuberculosis and Rv2159c-complemented MtbΔ2159 strains. Similarly, in a guinea pig model of pulmonary infection, MtbΔ2159 displayed growth attenuation in the lungs, compared to the wild type M. tuberculosis and Rv2159c-complemented MtbΔ2159 strains. Our study suggests that Rv2159c has a significant role in maintaining the cellular homeostasis during stress and virulence of M. tuberculosis

FLYWCH1, a novel suppressor of nuclear b-catenin, regulates migration and morphology in colorectal cancer

© 2018 American Association for Cancer Research. Wnt/b-catenin signaling plays a critical role during development of both normal and malignant colorectal cancer tissues. Phosphorylation of b-catenin protein alters its trafficking and function. Such conventional allosteric regulation usually involves a highly specialized set of molecular interactions, which may specifically turn on a particular cell phenotype. This study identifies a novel transcription modulator with an FLYWCH/Zn-finger DNA-binding domain, called "FLYWCH1." Using a modified yeast-2-hybrid based Ras-Recruitment system, it is demonstrated that FLYWCH1 directly binds to unphosphorylated (nuclear) b-catenin efficiently suppressing the transcriptional activity of Wnt/ b-catenin signaling that cannot be rescued by TCF4. FLYWCH1 rearranges the transcriptional activity of b-catenin/TCF4 to selectively block the expression of specific downstream genes associated with colorectal cancer cell migration and morphology, including ZEB1, EPHA4, and E-cadherin. Accordingly, overexpression of FLYWCH1 reduces cell motility and increases cell attachment. The expression of FLYWCH1 negatively correlates with the expression level of ZEB1 and EPHA4 in normal versus primary and metastatic colorectal cancer tissues in patients. Thus, FLYWCH1 antagonizes b-catenin/TCF4 signaling during cell polarity/migration in colorectal cancer. Implications: This study uncovers a new molecular mechanism by which FLYWCH1 with a possible tumor suppressive role represses b-catenin-induced ZEB1 and increases cadherin-mediated cell attachment preventing colorectal cancer metastasis