Taxonomic notes on the paper wasps of the genus Ropalidia in the Indian subcontinent (Hymenoptera: Vespidae)

The taxonomy of Ropalidia wasps in the Indian subcontinent is revised, recognizing 26 species in the subcontinent. Their diagnostic characteristics are summarized in a key to species. New synonymies proposed in the present study are: R. bicolorata shiva Das and Gupta, 1989 under R. bicolorata van der Vecht, 1962; R. colorata sordida van der Vecht, 1941 under R. colorata van der Vecht, 1941; R. rodialipa Lambert and Narendran, 2005 and R. anupama Lambert and Narendran, 2005, both under R. cyathiformis Fabricius, 1804; R. jacobsoni flavoscutellata Das and Gupta, 1989, and R. bangalorica Lambert and Narendran, 2005, both under R. jacobsoni du Buysson, 1908; R. travancorica Lambert and Narendran, 2005, under R. marginata Lepeletier, 1836; R. sridharani Lambert and Narendran, 2005, under R. rufocollaris Cameron, 1900; Ropalidia rufoplagiata nursei van der Vecht, 1941 under R. rufoplagiata Cameron, 1905; Icaria lugubris Smith, 1858, under R. sumatrae Weber, 1801; and a revised synonymy is Icaria pendula Smith, 1857, under R. variegata Smith, 1852. The new replacement name Ropalidia kasaragodensis Lambert and Narendran is proposed for R. indica Lambert and Narendran, 2005, non van der Vecht, 1941.     

Quantum-chemical studies on thermodynamic feasibility of 1-methyl-2,4,5-trinitroimidazole processes

1-Methyl-2,4,5-trinitro imidazole (MTNI) is a well-known melt cast explosive possessing good thermal stability and impact insensitivity. MTNI has been synthesized from multi-step nitration followed by methylation of imidazole exhibiting low yield. It is desirable to screen the process thermodynamically for evaluating feasibility of the process. In the present investigations, B3LYP method in combination with 3-21G** basis set has been chosen to evaluate the enthalpy of formation for reaction species by designing reasonable isodesmic reactions. Thermodynamic feasibility of the processes has been worked out assuming free energies of reactions as derived from standard enthalpy and entropy of the reaction species. All possible synthesis routes for the target molecule, MTNI has been conceptualized from different precursors/intermediates viz. imidazole, 2-nitroimidazole, 4-nitroimidazole, 1-methyl imidazole and 2,4,5-triiodoimidazole. Various nitrating agents have been employed and their effect studied for deciding the feasibility of the reaction. It has been found that reaction entropy and enthalpy are favorable on usage of NO₂BF₄ as nitrating agent. The charge on nitro group (?Q_NO2) has been used for better understanding of the reactivity of substrates/intermediates. Overall, the study helped in screening several possible routes for MTNI synthesis and identified the thermodynamically feasible process by using NO₂BF₄ as nitrating agent.     

Fungitoxicity of some higher plants againstRhizoctonia solani

Summary Leaves ofChenopodium ambrosioides exhibited strong fungitoxicity against the mycelial growth ofRhizoctonia solani causing damping off diseases of some seedlings. Minimum inhibitory concentration of the fungitoxic constituent isolated in form of essential oil, was found to be 1000 ppm at which it was fungicidal in nature. It exhibited broad range of antifungal activity and did not show any phytotoxicity on the germination and seedling growth ofPhaseolus aureus.     

Stimulation of immune suppressive CD34+ cells from normal bone marrow by Lewis lung carcinoma tumors

 Progressive growth of metastatic Lewis lung carcinoma (LLC-LN7) tumors is associated with increased levels of bone-marrow-derived CD34⁺ cells having natural suppressor (NS) activity toward T cells. The present studies determined whether tumor-derived products are responsible for this induction of NS activity. Culturing normal bone marrow cells with LLC-LN7-conditioned medium (LLC-CM) or with recombinant granulocyte/macrophage-colony-stimulating factor (GM-CSF) resulted in the appearance of NS activity. The development of NS activity coincided with a prominent increase in the levels of CD34⁺ cells. That the CD34⁺ cells were responsible for the NS activity of the bone marrow cultures containing LLC-CM was shown by the loss of NS activity when CD34⁺ cells were depleted. The stimulation of CD34⁺ NS cells by LLC-CM was attributed to tumor production of GM-CSF, since neutralization of GM-CSF within the LLC-CM reduced its capacity to increase CD34⁺ cell levels. Studies also showed that the induction of CD34⁺ NS cells by LLC-CM and GM-CSF could be overcome by including in the cultures an inducer of myeloid differentiation, 1α,25-dihydroxyvitamin D₃ [1,25(OH)₂D₃]. These results demonstrate that the mechanism by which the LLC-LN7 tumors stimulate increased levels of CD34⁺ NS cells from normal bone marrow is by their production of GM-CSF and that this can be blocked with the myeloid differentiation inducer 1,25(OH)₂D₃. Received: 8 December 1997 / Accepted: 27 February 1998     

Unilateral naris occlusion and the rat accessory olfactory bulb

Blocking airflow through half of the nasal cavity during early life results in a 25% reduction in the size of the ipsilateral main olfactory bulb. The present study indicates that the size of the accessory bulb is relatively unaffected by the procedure.