Foraging patterns and kleptoparasitism among three sympatric cormorants (Phalacrocorax spp.) from the Delhi region, North India

Cormorants, described as ‘foot-propelled pursuit divers’, constitute an important component of aquatic food webs and exhibit unique foraging behaviour patterns, which can be properly understood through a comparative study. Since, after a foraging dive they surface to ingest the prey, the intensity of kleptoparasitic attacks on the surface can have a major impact upon the net energetic gain for each individual. Inspite of the fact that cormorants and their habitats are severely threatened in India, their foraging behaviour has not been adequately studied. Such considerations prompted us to undertake field studies on three sympatric cormorants (Phalacrocorax spp.) at 60 different sites in the Delhi region of North India, during 2004–2007. By means of video photography, some key foraging parameters including group size, prey size and patterns of kleptoparasitic attacks were quantified. Along a loose body size gradient, we observed significant differences among the three species with respect to not only their preference for wetland size but also prey size. The frequency of a kleptoparasitic attacks depended upon the group size and foraging behaviour of each species. It was observed that several foraging bouts were abruptly terminated due to human disturbances, mostly at sites lying outside the protected areas. This observation points towards the need to conserve small waterbodies in the countryside, currently threatened by pollution and urbanization, for the benefit of a variety of waterbirds including cormorants.     

Marker-trait association analysis for gall midge (Orseolia oryzae) resistance in a diverse rice population

Damage caused by insect herbivores, notably Asian rice gall midge, Orseolia oryzae is more prevalent in the rice-growing belts of India's southern and north-eastern states. As a prelude to resistant cultivar development, the identification of genomic regions for resistance in the source population is crucial. In the present investigation, 202 rice genotypes were phenotyped and assayed with genomic markers reported for gall midge resistance. Positive skewness and platykurtic distribution of response scores suggested the inheritance of gall midge resistance in the study population. The marker gm3del3 contributed the most genetic variation, followed by RM28574 and marker RM22709 explained minimal variation. A marker-trait association analysis with a single marker-trait linear regression approach was performed to discover gall midge resistant genomic region/genes. The marker RM17480 on chromosome 4 reported to be linked with gm3 gene was found significantly associated with the gall midge resistance genomic region with allelic effects in a negative direction favouring resistance reaction. The allelic effects of significantly associated markers were correlated significantly with the phenotypic variation of gall midge damage scores. Genes identified in the vicinity of this marker contribute to stress response reactions in rice plants. The 200 bp allele of the marker was associated with susceptibility, while the 250 bp allele was associated with resistance expression. This allelic association with trait variation suggests the importance of associated marker for utilisation in marker-assisted selection programmes to incorporate resistance alleles into elite rice genotypes.     

Theoretical,in Vitro Antiproliferative,and in Silico Molecular Docking and Pharmacokinetics Studies of Heteroleptic Nickel(II) and Copper(II) Complexes of Thiosemicarbazone-Based Ligands and Pefloxacin

Twelve new heteroleptic nickel(II) and copper(II) complexes of the type [M(L^1–6)(Pfx)₂] ( 1 – 12 ), where L^1–6=2-benzylidenehydrazinecarbothioamide (L¹), 2-benzylidene-N-methylhydrazinecarbothioamide (L²), 2-benzylidene-N-phenylhydrazinecarbothioamide (L³), 2-(4-methylbenzylidene)hydrazinecarbothioamide (L⁴), 2-(4-methylbenzylidene)-N-methylhydrazinecarbothioamide (L⁵) and 2-(4-methylbenzylidene)-N-phenylhydrazinecarbothioamide (L⁶), Pfx=pefloxacin and M=Ni(II) or Cu(II) have been synthesised, and their structures were confirmed by different spectral techniques. The spectral data and density functional theory (DFT) calculations supported the bonding of pefloxacin drug molecule via one of the carboxylate oxygen atoms and the pyridone oxygen atom, and the thiosemicarbazone ligand via the imine nitrogen and the thione sulfur atoms with the metal(II) ion, forming distorted octahedral geometry. In vitro antiproliferative activity of the synthesized complexes was evaluated against three human breast cancer (T47D, estrogen negative (MDA-MB-231) and estrogen positive (MCF-7)) as well as non-tumorigenic human breast epithelial (MCF-10a) cell lines, which showed the higher activity for the copper(II) complexes. The interaction of the synthesized complexes with an oncogenic protein H-ras (121 p) was explored by in silico molecular docking studies. Further, in silico pharmacokinetics and ADMET parameters were also analysed to predict the drug-likeness as well as non-toxic and non-carcinogenic behavior, and safe oral administration of the complexes.     

In vitro antioxidant and antidiabetic activities of zinc oxide nanoparticles synthesized using different plant extracts

Phytofabricated green synthesis of zinc oxide (ZnO) nanoparticles using different plant extracts of Azadirachta indica, Hibiscus rosa-sinensis, Murraya koenigii, Moringa oleifera, and Tamarindus indica for biological applications has been reported. ZnO nanoparticles were also synthesized by chemical method to compare the efficiency of the green synthesized nanoparticles. FT-IR spectra confirmed the functional groups involved in the green synthesis of ZnO nanoparticles and the powder XRD patterns of the ZnO nanoparticles revealed pure wurtzite structure with preferred orientation at (100) reflection plane. SEM and TEM analysis revealed the spherical shape of the synthesized ZnO nanoparticles with the particle size between 54 and 27 nm. The antioxidant activity was evaluated by five different free radical scavenging assays. The present study also intends to screen α-amylase and α-glucosidase activity of ZnO nanoparticles synthesized using natural sources, which may minimize the toxicity and side effects of the inhibitors used to control diabetes. The ZnO nanoparticles synthesized using T. indica extract displayed remarkable antioxidant and antidiabetic activities.