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Abstract: Allometric bark biomass models for Cinnamomum tamala (one of the important commercial non-timber forest product tree species) have been developed using bark biomass and tree dimension data with thirty destructively sampled trees from the natural population in the mid-hill of Nepal. Diameter at breast height (D) alone and both D and total height (H) as independent variables and bark biomass (W) as dependent variable were used for modelling. The models were evaluated on the basis of numerical fit statistics, graphical appearance and biological logic. Among eighteen different models tested, the model of the form: W = DH/(b 1 + b 2 DH) accounted for the largest proportion of bark biomass variations ( = 0.92; RMSE = 3.67 kg) for individual C. tamala tree, and showed relatively better graphical appearance and biological logic. Reliability of the model would be higher when it is applied to various sizes of C. tamala trees growing in the site and stand conditions similar to the basis of this study. Further work on re-calibration and validation of proposed model with data from a larger geographic area, wider range of tree sizes, site and stand conditions is recommended. [Copyright &y& Elsevier]

The 17 amino acid peptide nociceptin has been implicated in pain modulation in the central nervous system. The effects of bath applied nociceptin, and some analogues of nociceptin, upon spontaneous lumbar dorsal root activity have been investigated in an isolated preparation of rat spinal cord. Nociceptin was found to reversibly depress spontaneous dorsal root activity at concentrations of 1.0 μM and 10.0 μM (IC50 2.0 μM), whereas acetyl-nociceptin at concentrations up to 10 μM had no detectable effect. Omission of the last four amino acids (nociceptin 1–13), increased the potency of the effect upon dorsal root activity by approximately 100-fold (IC50 30 nM), but activity was lost when only the first seven amino acids of the nociceptin molecule (nociceptin 1–7) were tested. [Copyright &y& Elsevier]

Absolute stereochemistry of dihydroarteannuin B 5 obtained by the reduction of arteannuin B 3 with Ni2B, NaBH4 or CdCl2–Mg–MeOH–H2O has been established by 2D NMR and single crystal X-ray diffraction studies. Some experiments aimed at the synthesis of dihydrodeoxyarteannuin B [C-4, 5 double bond isomer of 11] are also discussed. [Copyright &y& Elsevier]