Crown-Stump Diameter Model for Parkia biglobosa Benth. Species in Makurdi, Benue State, Nigeria

The crown of tree is the centre of physiological activity which gives an indication of the potential photosynthetic capacity on a tree. Though, its measurement remains a challenge in forest inventory task. The ability to predict crown diameter from stump diameter provides an effective technique of obtaining its estimate. This helps in detecting the excessive tree felling than actual requirements and wildlife suitability.The main objective of this study was to develop and test crown diameter prediction models for silvicultural management of naturally grown Parkia biglobosa within the University of Agriculture, Makurdi. Nine 100 m x 100 m temporary sample plots were established using simple random sampling method. Crown diameter and stump diameter were measured in all living P. biglobosa trees with stump diameter ≥10.0 cm. Least square method was used to convert the counted stumps into harvested crown dimension. Three linear and three non-linear models using stump diameter as the exploratory variable were developed and evaluated using the adjusted coefficient of determination (Adj.R2), standard error of estimate (SEE), prediction error sum of squares (PRESS) and Akaike information criterion (AIC). The crown-stump diameter relationship was best described by the double logarithmic function with .The result showed that Crown diameter estimation was feasible even when the only information available is stump diameter.The resulting equation was tested for validation with independent data obtained from additional plots and was found to be desirable for estimating the crown diameter for Parkia biglobosa in Makurdi, Benue State, Nigeria

Pd(II) complexes with N-substituted pyrazoles as ligands. The influence of the R group [OMe versus NMe2] of [1-{R(CH2)2}-3,5-Ph2(C3HN2)] on their cytotoxic activity on breast cancer cell lines

The study of the reactivity of the novel pyrazole derivative [1-{MeOe(CH2)2e}-3,5-Ph2e(C3HN2)] (1) with Na2[PdCl4] or Pd(OAc)2 under different experimental conditions has allowed us to isolate and characterize the trans-isomers of [Pd{[1-{MeOe(CH2)2e}-3,5-Ph2e(C3HN2)]}2(X)2] [X ¼ Cl (2) or OAc (3)] and the di-m-ligand bridged cyclopalladated complexes [Pd{k2,C,N[1-{MeOe(CH2)2e}-3-(C6H4),5-Ph- (C3HN2)]}(m-X)]2 [X ¼ OAc (4) or Cl (5)]. Further treatment of compounds 4 or 5 with PPh3 in CH2Cl2 produced the bridge splitting and the formation of [Pd{k2,C,N[1-{MeOe(CH2)2e}-3-(C6H4),5-Ph- (C3HN2)]}X(PPh3)] [X ¼ OAc (6) or Cl (7)]. The cytotoxic assessment of the free ligand (1) and the Pd(II) complexes on the two breast cancer cell lines MCF7 and MDA-MB231 reveals that: a) compound 1 is less active than its analogue [1-{Me2Ne(CH2)2e}-3,5-Ph2e(C3HN2)] (Ic) and b) palladacycles 4e7 showed a remarkable cytotoxic activity in the MDA-MB231 cell line (with IC50 values in the range 9.1e14.4 mM)