Central University of Kerala

About: Central University of Kerala is a education organization based out in Kāsaragod, India. It is known for research contribution in the topics: Population & Catalysis. The organization has 556 authors who have published 881 publications receiving 7474 citations.

Effect of CoFe 2 O 4 weight fraction on multiferroic and magnetoelectric properties of (1 − x )Ba 0.85 Ca 0.15 Zr 0.1 Ti 0.9 O 3 − x CoFe 2 O 4 particulate composites

Abstract: Different compositions of the composite lead-free multiferroic magnetoelectric systems are fabricated by employing piezoelectric Ba0.85Ca0.15Zr0.1Ti0.9O3 (BCZT) and magnetostrictive CoFe2O4 (CFO) by varying the CFO weight fraction. The magnetic, dielectric, ferroelectric and magnetoelectric (ME) properties of the system are analyzed and found to be varying with the ferrite concentration. Even though the composite systems exhibit high magnetocapacitance (MC) properties (~ 35%), the possible stray contributions from magnetoresistance and magnetostriction make it unreliable for the quantitative determination of ME coupling coefficient (MECC). Therefore, a dynamic method is chosen for the measurement of magnetoelectric coupling. All the compositions have shown fairly good ME coupling. It is found that the ME coupling increases with ferrite fraction and the highest ME coupling of 14.8 mV/(cm Oe) is observed for 0.6BCZT–0.4CFO composite. It is also observed that the ME voltage increases linearly with the ac modulating field with a voltage generation of 1.25 V/cm (for x = 0.4) for a small ac modulating field of 100 Oe. This high sensitivity and linear response of ME coupling to the ac magnetic fields offer the possibility of employing these particulate composites for a wide range of applications from magnetic field sensors to energy harvesters.

Nesting tree characteristics of heronry birds of urban ecosystems in peninsular India: implications for habitat management.

Abstract: Wetland ecosystems, particularly the mangrove forest, are the primary wild habitat of heronry birds. However, urban ecosystems have become a favorite breeding habitat of these birds. To provide inputs into the habitat management for conservation of these birds, we investigated the quantitative and qualitative characteristics of nesting trees of heronry birds in the urban environment of the North Kerala region of peninsular India. Census on nesting trees was done in 3 major microhabitats of the urban ecosystem: avenues of national highways and towns, nonresidential plots, and residential areas apart from the mangrove islets in the peri-urban locality. The study found that 174 trees of 22 species hosted 1,928 heronry bird nests in the urban habitats; mangrove forests, although plentiful in the study area, hosted only about 20% of the total nests encountered in the study. Rain trees Samanea saman (43.7%) were the most available nesting tree. The greatest number of nests and nesting trees were encountered on the roads of urban areas, followed by nonresidential areas and residential areas. The differences in the observed frequencies of nesting trees in 3 microhabitats and in 3 types of roads (national highways > state highways > small pocket road) were significant. Canopy spread, girth size, and quality of the trees predicted the tree selection of the heronry birds in urban environments. Therefore, we recommend proper management and notification of the identified nesting trees as protected sites for the conservation of herorny birds.

Inhibition of Microbial Quorum Sensing Mediated Virulence Factors by Pestalotiopsis sydowiana.

Abstract: Quorum sensing (QS)-mediated infections cause severe diseases in human beings. The control of infectious diseases by inhibiting QS using antipathogenic drugs is a promising approach as antibiotics are proving inefficient in treating these diseases. Marine fungal (Pestalotiopsis sydowiana PPR) extract was found to possess effective antipathogenic characteristics. The minimum inhibitory concentration (MIC) of the fungal extract against test pathogen Pseudomonas aeruginosa PAO1 was 1,000 μg/ml. Sub-MIC concentrations (250 and 500 μg/ml) of fungal extract reduced QS-regulated virulence phenotypes such as the production of pyocyanin, chitinase, protease, elastase, and staphylolytic activity in P. aeruginosa PAO1 by 84.15%, 73.15%, 67.37%, 62.37%, and 33.65%, respectively. Moreover, it also reduced the production of exopolysaccharides (74.99%), rhamnolipids (68.01%), and alginate (54.98%), and inhibited the biofilm formation of the bacteria by 90.54%. In silico analysis revealed that the metabolite of P. sydowiana PPR binds to the bacterial QS receptor proteins (LasR and RhlR) similar to their respective natural signaling molecules. Cyclo(-Leu-Pro) (CLP) and 4-Hydroxyphenylacetamide (4-HPA) were identified as potent bioactive compounds among the metabolites of P. sydowiana PPR using in silico approaches. The MIC values of CLP and 4-HPA against P. aeruginosa PAO1 were determined as 250 and 125 μg/ml, respectively. All the antivirulence assays were conducted at sub-MIC concentrations of CLP (125 μg/ml) and 4-HPA (62.5 μg/ml), which resulted in marked reduction in all the investigated virulence factors. This was further supported by gene expression studies. The findings suggest that the metabolites of P. sydowiana PPR can be employed as promising QS inhibitors that target pathogenic bacteria.

The Applications of TDZ in Medicinal Plant Tissue Culture

Abstract: Thidiazuron (TDZ; N-phenyl-1, 2, 3-thidiazole-5ylurea) is a cytokinin-like compound routinely used for in vitro culture studies including shoot proliferation and regeneration in various plants. Recently, there is an increased use of TDZ in in vitro propagation of plants including medicinal and horticultural crops. TDZ was found to be more effective in micropropagation, multiple shoot induction, somatic embryogenesis, callus induction, and shoot organogenesis as compared to other cytokinins. In some systems the synergistic effect of TDZ with other cytokinin/auxin was found more effective than using alone. The optimum concentration of TDZ may vary based on the plant species, explants, and duration of exposure. In this review we have described the recent trends in the use of TDZ for micropropagation of some medicinal plants. The medicinal plants described in this chapter include Picrorhiza kurroa, Aronia melanocarpa, Scutellaria ocmulgee, Salvia miltiorrhiza, Aphyllorchis montana, Gentiana decumbens, Aconitum balfourii, Pelargonium sidoides, Withania somnifera, Curculigo latifolia, Hedychium coronarium, Mentha arvensis, Clitoria ternatea, Saussurea involucrata, Jatropha curcas, Medicago sativa, Crocus sativus, Zingiber officinale, Cannabis sativa, Arnebia euchroma, and Azadirachta indica.