C.E. Mokobia

Bio: C.E. Mokobia is an academic researcher from Delta State University, Abraka. The author has contributed to research in topics: Thermoluminescence & Delta. The author has an hindex of 7, co-authored 17 publications receiving 179 citations.

The effect of gamma irradiation on the germination and growth of certain Nigerian agricultural crops

Abstract: Gamma irradiation has been found to be very useful both for sterilisation in medicine and the preservation of food and cereals in nutrition and agriculture. This investigation was carried out to determine the effect of gamma irradiation on the subsequent germination and growth of irradiated seeds. Thirty seeds each of maize, okra and groundnut were irradiated to varying doses of 150, 300, 500, 700, 900, 1000 Gy using the 60Co gamma cell irradiator facility at the Centre for Energy Research and Development, Obafemi Awolowo University, Ile-Ife. These, as well as the controls (unirradiated seeds), were planted on the same day in an already prepared area of farmland during the rainy season to ensure a constant moisture flow. The times of germination and subsequent growth were monitored. Results show that maize, okra and groundnut seeds needed for planting can be safely stored using gamma irradiation. However, the study reveals that the number of germinated seeds and the growth rate for the crops decrease with increase in the radiation dose the seeds were exposed to. Third-degree polynomial equations were derived which describe the percentage germination of the crops at various levels of exposure. A chart of percentage germination of seeds versus exposure dose is also presented as a quick guide to farmers, policy makers and agricultural institutions.

Natural radioactivity associated with bituminous coal mining in Nigeria

Abstract: Gamma spectroscopic method was used to determine the natural radioactivity associated with the mining of Nigerian bituminous coal for the purpose of determining the radiological implications of coal mining in the country. The activity concentrations of the radionuclides detected range from 0.20±0.002 to 48.42±5.32 Bq kg −1 . The overall natural radionuclide contribution to the radioactivity of the environment was found to be 404.16±23.44 Bq kg −1 . Of this, coal waste (tailing) alone contributed 49.5% representing the largest contribution. Coal contributed just 5.5%. A comparison of the concentrations obtained in this work for coal with those from other parts of the world indicates that the radioactivity content of the Nigerian bituminous coal is not significantly different. The outdoor and indoor exposure rates in air 1 m above the ground are estimated to be (6.31±1.20)×10 −8 and (7.57±1.20) ×10 −8 Gy h −1 , respectively, for the mining environment. These values compare very well with the global values reported by UNSCEAR: 5×10 −8 and 6×10 −8 Gy h −1 , respectively. The resulting annual effective dose equivalent estimated is (4.49±0.74)×10 −4 Sv yr −1 . This also compares favourably with the global value −4×10 −4 Sv yr −1 , reported by UNSCEAR.

Natural radionuclides in borehole water in Port Harcourt, Rivers State, Nigeria

Abstract: Water samples from boreholes collected from 29 locations in two local government areas in Port Harcourt, Rivers State, Nigeria have been analysed for their natural radioactivity content using a well-calibrated, shielded and highly efficient NaI(Tl) detector based gamma ray with a view to provide baseline data on the radioactivity level in the area, as well as an estimate of the resulting dose on the inhabitants. The radionuclides observed with reliable regularity belonged to the decay series chain headed by (238)U and (232)Th as well as the non-series (40)K. The mean specific activity concentrations of these, are 3.51 +/- 1.22, 2.04 +/- 0.29 and 23.03 +/- 4.37 Bq l(-1), respectively. The respective corresponding estimated mean annual effective dose are 0.36 +/- 0.12, 0.51 +/- 0.07 and 0.05 +/- 0.01, respectively mSv y(-1). These results are relatively high but are still below the recommended limit of 1 mSv y(-1) due to borehole water only. This study is the first in the area and can usefully be associated with similar surveys in other matrices in the area. Meanwhile, the radionuclides detected in the water samples do not seem to pose any radiological consequence on the sample population.

Effect of gamma radiation on morphological, biochemical, and physiological aspects of plants and plant products

Abstract: Research on the basic interaction of radiation with biological systems has contributed to human society through various applications in medicine, agriculture, pharmaceuticals and in other technolog...

Physical Methods for Seed Invigoration: Advantages and Challenges in Seed Technology.

Abstract: In the context of seed technology, the use of physical methods for increasing plant production offers advantages over conventional treatments based on chemical substances. The effects of physical invigoration treatments in seeds can be now addressed at multiple levels, ranging from morpho-structural aspects to changes in gene expression and protein or metabolite accumulation. Among the physical methods available, "magneto-priming" and irradiation with microwaves (MWs) or ionizing radiations (IRs) are the most promising pre-sowing seed treatments. "Magneto-priming" is based on the application of magnetic fields and described as an eco-friendly, cheap, non-invasive technique with proved beneficial effects on seed germination, vigor and crop yield. IRs, as γ-rays and X-rays, have been widely regarded as a powerful tool in agricultural sciences and food technology. Gamma-rays delivered at low dose have showed to enhance germination percentage and seedling establishment, acting as an actual 'priming' treatment. Different biological effects have been observed in seeds subjected to MWs and X-rays but knowledge about their impact as seed invigoration agent or stimulatory effects on germination need to be further extended. Ultraviolet (UV) radiations, namely UV-A and UV-C have shown to stimulate positive impacts on seed health, germination, and seedling vigor. For all mentioned physical treatments, extensive fundamental and applied research is still needed to define the optimal dose, exposition time, genotype- and environment-dependent irradiation conditions. Electron paramagnetic resonance has an enormous potential in seed technology not fully explored to monitor seed invigoration treatments and/or identifying the best suitable irradiation dose or time-point to stop the treatment. The present manuscript describes the use of physical methods for seed invigoration, while providing a critical discussion on the constraints and advantages. The future perspectives related to the use of these approaches to address the need of seed technologists, producers and trade markers will be also highlighted.

Effects of gamma radiation on germination and physiological aspects of wheat (triticum aestivum l.) seedlings

Abstract: This investigation was carried out to determine the effects of gamma radiation on germination and physiological characteristics of wheat seedlings. Two wheat genotypes (Roshan and T-65-58-8) were irradiated with 100, 200, 300 and 400 Gy. The results showed that MGT (Mean Germination Time), root and shoot length, and seedling dry weight decreased with increasing radiation doses but final germination percentage was not significantly affected by radiation doses. Biochemical differences based on proline content revealed that seedling irradiated at 100 Gy contained highest amount of proline (1.71 mg/g FW), whereas only 0.92 mg/g FW of proline was detected in nonirradiated seedlings. The highest amount of total chlorophyll content was obtained in seedlings irradiated at 100 Gy. Furthermore, the concentration of chlorophyll a was higher than chlorophyll b in both irradiated and non-irradiated seedlings. Chlorophyll and proline contents, and root and shoot dry weights in cv. Roshan were higher than those in T-65-58-8 mutant. These results show that the up-regulation of some physiological characteristics and seedling growth of wheat following gamma radiation treatment may be used for aboitic control such as drought and salt stress.

Turning a blind eye: the mobilization of radiology services in resource-poor regions

Abstract: While primary care, obstetrical, and surgical services have started to expand in the world's poorest regions, there is only sparse literature on the essential support systems that are required to make these operations function. Diagnostic imaging is critical to effective rural healthcare delivery, yet it has been severely neglected by the academic, public, and private sectors. Currently, a large portion of the world's population lacks access to any form of diagnostic imaging. In this paper we argue that two primary imaging modalities--diagnostic ultrasound and X-Ray--are ideal for rural healthcare services and should be scaled-up in a rapid and standardized manner. Such machines, if designed for resource-poor settings, should a) be robust in harsh environmental conditions, b) function reliably in environments with unstable electricity, c) minimize radiation dangers to staff and patients, d) be operable by non-specialist providers, and e) produce high-quality images required for accurate diagnosis. Few manufacturers are producing ultrasound and X-Ray machines that meet the specifications needed for rural healthcare delivery in resource-poor regions. A coordinated effort is required to create demand sufficient for manufacturers to produce the desired machines and to ensure that the programs operating them are safe, effective, and financially feasible.