Growth and development of cellular slime mould Dictyostelium discoideum treated with DDT

The effects of dichlorodiphenyl trichloroethane (DDT) on the growth, phagocytic activity, ultrastructure and developmental stages of a well known species of the cellular slime mould, Dictyostelium discoideum were studied. DDT, at doses of 60 ppm and above, inhibited growth of the vegetative cells and this was also evident from the colony blots which were smaller in size. A dose-dependent inhibition occurred in the phagocytic activity and macromolecular syntheses of DDT-treated cells. The cytomorphology of growing Dictyostelium cells, as revealed under light and electron microscopes, was profoundly affected by DDT treatment. Further, a considerable delay occurred in the various morphogenetic events in the slime mould cells exposed to DDT.     

Imperatives for attracting investment and technology in the Indian mining sector

In India, the mineral resource inventory and the production of a large number of important minerals have registered significant increases during the last few decades. Yet the country continues to be a net importer of many high value and scarce minerals and metals, like gold, diamond, and several base metals. Exploration and development of the resources of these minerals are technology- and capital-intensive. To bring technology and capital through foreign direct investment (FDI) into the Indian mineral sector, it is imperative to lay stress on: accurate resource estimation and categorization, as well as realistic projection of the true values; rationalization of legislative measures based on R&D studies and reorganization of the implementation machinery; conducive tax structure; notification of acts and rules applicable to offshore mineral resources; time-frames for granting licences and leases; encouragement to labor productivity by rationalizing labor laws; reforms in the monetary system to increase market competitiveness of Indian minerals; and judicial reforms. FDI in the Indian mineral sector is important to firm up the knowledge-base of mineral resources and their optimum exploitation.     

An application of 3D gasdynamic modeling for the prediction of overpressures in vented enclosures

A three-dimensional gasdynamic model with constant burning rate is applied for the prediction of the maximum pressure rise from gaseous combustion in vented enclosures. A series of calculations for an enclosure with aspect ratio close to unity are presented. Both cases with and without obstacles in the enclosure are considered. Results of calculations are compared with a simple 0D solution for spherical vessels. It is shown that, in cases without obstacles, the 0D solution for the maximum reduced overpressures is close to the predictions of the detailed modeling. In cases with obstacles, the detailed simulation gives significantly higher overpressures than those from the 0D model. However, in all the cases the reduced pressures are correlated well with the maximum flame surface area.     

Mercuric chloride effects on adult rat oval cells-induced apoptosis

In the present investigation, the toxicity of mercuric chloride (HgCl₂) was evaluated in adult oval cells isolated from rat utilizing the 2-acetylaminofluorene/partial hepatectomy technique. Isolated oval cells were incubated with 5 μM of HgCl₂ for 8 hr to elucidate in vitro cytotoxic responses. Recently, autophagic cell death was found in rat hepatocytes in vitro within 30 min of incubation with 5 μM of mercury (Hg) which triggered apoptosis and necroptosis in a time-dependent manner. Nuclear degradation occurred within 30 min of incubation and progressed with time until 8 hr. Apoptosis evidenced by activation of caspase-dependent pathway between 30 min to 8 hr of incubation was mediated via interchange of death domain signaling pathways. Receptor-interacting protein played a positive role to modulate the death domain receptors in the scenario of apoptotic death of oval cells until 6 hr. Autophagic marker proteins ATG12 and LC3B exerted a significant role in triggering apoptosis in 5 μM Hg-treated oval cells. No apparent expression of apoptosis-inducing-factor (AIF) and HMGB1 indicated absence of caspase-independent apoptosis and necrosis in the rat oval cells between 30 min and 8 hr. Thus a low concentration of Hg modulates programmed cell death in adult rat oval cells by altering expression of proteins involved in the molecular mechanisms of cellular functions.     

Persistence of metaflumizone on cabbage (Brassica oleracea Linne) and soil, and its risk assessment

Metaflumizone is a novel sodium channel blocker insecticide of semicarbazone class. It provides good to excellent control of most of the economically important lepidopterous pests and certain pests in the orders Coleoptera, Hemiptera, Hymenoptera, Diptera, Isoptera, and Siphonaptera. Although metaflumizone has been marketed globally for several years and got registered in India in the year 2009, specifically for the control of DBM on cabbage, to our knowledge, no food safety aspects of metaflumizone residue on cabbage have ever been reported in the literature in India or elsewhere. The present study was undertaken to evaluate the persistence of metaflumizone on cabbage and soil, vis-a-vis its risk assessment, following two spray applications of metaflumizone 220 SC (Verismo®), each at recommended and double dose of 200 and 400 g?a.i.?ha^?1 respectively. Initial residue deposits of metaflumizone on cabbage were 0.46 and 0.51 mg?kg^?1 at recommended and 0.76 and 0.85 mg?kg^?1 at double the recommended dose following the first spray and second spray application. The residues persisted beyond 5 days from both the treatments and dissipated with the half-life ranging from 1.7–2.1 days. Initial deposits of metaflumizone on soil ranged from 0.23–0.37 mg?kg^?1 and degraded with a half life ranging from 4.0–4.8 days. No degradation product of metaflumizone was detected in cabbage and soil at any point of time. Soil samples collected from the treated field after 7 days were free from any residue of metaflumizone or its metabolites. A pre-harvest waiting period of 3 days after application was suggested based on calculation of theoretical maximum daily intake.