Trends in nitrate-nitrogen, nitrite-nitrogen and phosphorus concentration in Ebonyi river, Nigeria

A baseline study of the limnological integrity of Ebonyi River, a tropical lotic system in south-eastern Nigeria was conducted between September 2006 and February 2008 to assess its potential in enhancing fisheries production for the benefit of the rural poor, who depend on the resources of the river for survival. The parameters measured were nitrate-nitrogen, nitrite-nitrogen and phosphate-phosphorus. Results show that nitrate varied between 40.43mg/L in September 2006 and 1.73mg/L in December 2007, Showing significant difference (P<0.01) among months. The values recorded for nitrites varied between 0.2mg/L in September 2006 and 0.4mg/L in February 2008, showing significant (P<0.01) variation among months. Values recorded for phosphorus was highest (0.05mg/L) in the month of October 2006 while the least mean value (0.32mg/L) was recorded in the month of May 2007 and showed significant (p<0.01) variation in monthly means. It was concluded that the values of the measured parameters falls within tolerable range for enhanced fisheries development in the area. KEYWORDS: Limnology, Tropical, River, Monthly, Mean, Variation

Transformation empirique des tables numeriques de Galton en tables des probits

Comparison between Galton equation and preston normal logarithms models allowed an empirical reconstitution of probits tables.

Synthesis and stereochemical assignments of diastereomeric Ni(II) complexes of glycine Schiff base with (R)-2-(N-{2-[N-alkyl-N-(1-phenylethyl)-amino]acetyl}amino) benzophenone; a case of configurationally stable stereogenic nitrogen

A family of chiral ligands derived from alpha-phenylethylamine and 2-aminobenzophenone were prepared by alkylation of the nitrogen atom. Upon reaction with glycine and a Ni(II) salt, these ligands were transformed into diastereomeric complexes, as a result of the configurational stability of the stereogenic nitrogen atom. Different diastereomeric ratios were observed depending on the substituent R introduced in the starting ligand, and stereochemical assignments were based on X-ray analysis, along with NMR studies and optical rotation measurements.

Religion, emotions and social transformation along migratory processes. The cases of African church leaders in Spain and South Africa

221 p.