Department of Biological Sciences
Permanent URI for this collectionhttp://localhost:4000/handle/20.500.12092/1953
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Item Antimicrobial acitivity of extracts from Tephrosiavogelii Hook F.(Jomo Kenyatta University of Agriculture & Technology (JKUAT), Kenya, 2006) Wanga, B. N.; Akenga, T.; Imbuga, M.; Gitonga, L.; Olubayo, F.; Namungu, P.The dichloromethane extracts of the root and leaf of Tephrosia vogelii Hook F. (Family: Papilionaceae) grown in Kenya, were subjected to antimicrobial assays against Staphylococcus aureus, Escherichia coli and Fusarium phoseolida. The minimum inhibition concentrations (MIC) ranged between 0.25 to 6.4 μg/ml for all the microorganisms tested. The crude root and leaf extracts were also toxic to the brine shrimps, organisms used as indicators of toxicity (LC50: 0.960; 0.958μg/ml,respectively). Chromatographic separation led to the identification of (6aß, 12aß, 5'ß)-6a, 12a, 4',5'-tetra hydro-2,3-dimethoxy 5'-ß- isopropenyl–furano (3',2': 8,9)-6H-rotoxen-12-one, (rotenone) in 9.75% yield, (roots), and 11.75% (leaves). Characterisation was achieved by use of spectroscopic techniques and comparison with rotenone standard and literature data. Novel HPLC conditions for purification of rotenoids were established. The MIC of rotenone against the tested microbes was found to be 5.2 and 1.0 μg/ml for Staphylococcus aureus and Escherichia coli respectively, while the LC50 against the brine shrimps was found to be 3.20 μg/ml. The findings indicate that the extracts of T. vogelii contain metabolites that have antimicrobial activity comparable to other medicinal plants.Item Influence of work environment on organizational performance in government ministries in Kenya(strategic Journals, 2015-10-16) Gitonga, L.; Gachunga, H.Work environment has both positive and negative effects on the psychological and welfare of employees. The Kenyan government acknowledges that over the years there has been poor performance in the public sector, thus hindering service delivery which affect the realization of sustainable economic growth. The general objective of the study was to establish the influence of work environment on organizational performance in government ministries in Kenya. The target population was drawn from 6 government ministries based on the performance contracting reports of 2012. The total population was 7913 and the sample size was 367 according to (Krecie and morgan 1970) table. Stratified random sampling technique was employed in selecting the sample. The study adopted descriptive research design and primary data was collected using a questionnaire in the selected government ministries. A pilot study was done to test the validity and reliability of the instrument for data collection. Data was analysed by SPSS version 21. The study employed quantitative analysis techniques and correlated and generated findings showing that the variables were significantly and positively influenced organizational performance in government ministries in Kenya. Psychosocial environment was the most significant factor and had a positive significant relationship at 5% level of significance. The study recommends that there is need to ensure effective policies to enhance organizational performance in government ministries in Kenya as established in the study.