Tag Archives: Activity

Natural Radioactivity in Drinking Water Sources in Kargi Area, Marsabit – Kenya (Published)

Kargi is located between latitudes 2.476944 and 2.520833 N and longitudes 37.542778 and 37.601944 E covering an area of approximately 31.26 km2.  Health facilities in the area have reported a number of cancer disease cases and deaths annually thus prompting for the study. 14 number water samples were collected in Kargi, Marsabit with the aim of assessing the area’s environmental radioactivity together with radiological health hazard. Radionuclides are considered as radiation exposure source which has been recorded to have damaging health effects for such populations living in high back-ground radiation areas. Natural radioactivity concentrations owing to 40K, 232Th and 226Ra radionuclides were measured by using gamma ray spectrometry employing a high purity germanium (HPGe) type detector at University of Nairobi’s Nuclear Science & Technology Institute, INST. To assess the natural radioactivity’s radiological hazard, absorbed dose rate, radium equivalent together with effective dose have been computed and results compared with internationally accepted values. The mean values for activities for 40K ranged from -0.88 to 81.22 Bql-1 (mean: 52.68±25.07 Bql-1), 232Th ranged from -2.00 to 7.99 Bql-1(mean: 2.20±2.74 Bql-1) and 226Ra ranged from -0.25 to 7.84 Bql-1(mean: 3.55±3.04 Bql-1). Mean 232Th and 40K values were 2 times and 5 times higher than the limit values respectively, hence the area can be categorized a high back-ground radiation area, HBRA. The mean values with their standard deviations for calculated and measured dose rates below and above surface (1 m from the ground) were 5.37±2.93 and 77.76±27.82 nGyh-1 respectively. The computed radium equivalent values of all 14 samples were lower than accepted limit of 370 Bqkg-1 (Lu Xinwei et al., 2006). The mean elemental ratio for Th/U was lower than 3, an indication of thorium depletion or enrichment in the area. Investigated waters in this area are acceptable for life-long human consumption since their values of annual effective doses proved lower than the world-wide values.

Keywords: Activity, gamma-ray spectrometry, kargi-marsabit, lifetime cancer risk, nuclear science

Evaluation of Analgesic Property of Desmodium Velutinum (P.Beauv.) Dc (Papilionaceae) (Published)

Desmodium velutinum (family Papilionaceae) is used in Nigeria and Lokoja in particular for the treatment of abdominal pain among others. The LD50 was evaluated along with analgesic properties. The analgesic effects of the methanol extract of D. velutinum were investigated at three dose levels (100, 200, 300) mg/kg on the experimental models of pain in mice. The result of LD50 was greater than 3000mg/kg showing D. velutinum extract is relatively safe for human consumption. The anti-nociceptive activity was evaluated using the hot-plate and abdominal constriction tests. The extracts produced significant (P<0.05) inhibition of thermal nociception induced by hot plate. On chemical nociception induced by intra-peritoneal acetic acid, the extracts significantly (P<0.05) decreased the number of writhing episodes and the  time spent before jumping off the hot-plate in a dose independent manner. These results suggest that the extract of D.velutinum may act by inhibiting the mediators of pain. These findings may justify the use of the plant in traditional medicine in the management of pain and related diseases in Nigeria.

Keywords: Activity, Anlgesic, Desmodium Velutinum, Evaluation, Papilionaceae

A Study on the Diel Activity of Myriapods (Diplopoda, Chilopoda) In Natural and Anthropogenically Influenced Habitats (Published)

The present paper provides the results of a study on the diel activity of millipedes and centipedes from two different in terms of anthropogenic impact sites located in northeastern Bulgaria. The presumed differences in the diel activity of myriapods were tested using various statistical methods: the criterion of Kolmogorov, 2 criterion of uniformity, Pearson’s normalized correlation coefficients, and the multivariate regression analysis. . The results show that the diel surface activity of the established species depends on the degree of illumination (number of hours in a day), the air and the soil temperature. However, the activity was not affected by relative humidity, active seasons, and the degree of anthropogenic impact. The diurnal activity conducted in urban and natural habitats confirmed the nocturnal nature of the established species, which are most active in the time interval from 10:00 pm to 4:00 am. This activity is likely to have endogenous nature and it is controlled by internal physiological factors, but its duration may vary according to the changes in the environmental conditions.

Keywords: Activity, Bulgaria, Circadian Rhythms, Rural, Urban