ABSTRACT
This study was conducted to examine the impact of changes in annual mean temperature, annual mean precipitation, carbon footprint, ecological footprint, and area harvested on cereal crop production in East Africa. The study was conducted in a panel cointegration framework using annual time series from 1980 to 2018 for five East African countries i.e., Ethiopia, Kenya, Rwanda, Tanzania, and Uganda. Unit root tests were performed using LLC, IPS, ADF-Fisher, and PP-Fisher tests, while panel co-integration tests were performed using Pedroni residual, Kao residual, and Johansen Fisher panel co-integration tests. Long-run coefficients were estimated using the Pooled Mean Group/Autoregressive Distributed Lag, Panel Fully-modified OLS, and Panel Dynamic OLS models. Empirical findings from the three models revealed that increases in annual mean temperature have adverse effects on cereal crop production, while increases in annual mean precipitation, carbon footprint, ecological footprint, and area harvested have positive effects on cereal crop production in East Africa. Based on these findings, it can be suggested that prioritization of climate change adaptation strategies in the region such as the development of drought and heat-resistant crop varieties, changing in planting dates, and investment in irrigation technologies to boost cereal crops productivity could play a role in minimizing the adverse effects of changes in climate factors.

ABSTRACT
The objective of this seminar is to present the levels of metals in commercially available imported and Ethiopian rice. The levels of thirteen metals (Ca, Mg, K, Na, Fe, Mn, Zn, Cu, Co, Ni, Cr, Cd and Pb) were determined in six varieties of raw rice collected from Addis Ababa supermarket, Fogera town and Amahara Regional Agricultural Research Institute and in one selected cooked rice by flame atomic absorption spectrometry after digesting the powdered rice samples with HNO3, HClO4 and H2O2 mixture. The levels of metals found in the imported and Ethiopian rice, respectively, were in the ranges (mg/kg): Ca 75.8- 630, 205-427; Mg 90.6-150, 99.5-2250; K 1680-2150, 1100-3020; Na 70.6-78.6, 26.7-80.9; Fe 48.9-117, 41.3-113; Mn 4.1-15.5, 3.7-16.6; Zn 16.4-25.7, 15.6-140; Cu 2.7-4.9, 3.3-15; Co 12.6- 14.6, 8.8-10.4; Ni 2.5-75.1, 41.5-69.7; Cr 2.2-3.12, 2.32-4.82; Cd Comparison between levels of metals in the imported and Ethiopian rice showed significant differences for most of the metals. The results indicated that Ethiopian rice is comparatively rich in essential metals than imported one. A statistical analysis of variance (ANOVA) at 95% confidence level for metal determination indicated significant difference between the means of each variety of samples. Comparison between levels of metals in cooked and raw rice showed that the difference in the level is not significant.

ABSTRACT
This work's main objective was to evaluate the effect of certain strains of arbuscular mycorrhizal fungi on acid phosphatase activity during growth. The treatments applied were, control, Glomus intraradices, Acaulospora tuberculata, Gigaspora margarita, Glomus sp., and the mixture of these four AMF strains. Their effect on the growth of vitroplants was evaluated on days 60, 120, and 180 after inoculation. Mycorrhizal status following treatments and acid phosphatase activity were assessed. The minitubers obtained were subjected to a preservation and germination test. The results showed that the maximum growth peak of X. sagittifolium plants was obtained on day 120 for all treatments. The mixture of the four strains of AMF had more influence on the growth parameters with values of 18.40±0.54 Cm and 42.34±16.67 Cm2, respectively for the average number of roots and leaf area. Mycorrhization did not significantly influence the mean number of leaves and mean plant height. Mycorrhizal structures were observed in all mycorrhizal treatments applied. The frequency of mycorrhization was very high in plants inoculated with Glomus sp. The evaluation of the phosphatase activity shows a significant activity at the level of the leaves with a peak of activity in the plants inoculated with Glomus sp. (47.72±0.07 µM/min/g of FW). Compared to the control, the number of minitubers produced was two to three times higher. The best tuberization percentage (80%) was obtained in plants inoculated with a mixture of AMF strains. The temperature of 7~10°C allowed the preservation of 50% of the germination capacity of the minitubers after two months. Based on the obtained results, it was concluded that fertilization with AMF is beneficial for the stimulation of minitubers production.

ABSTRACT
Traditionally, topographic maps are usually employed for drainage analysis. However, channel network extraction and watershed delineation from topographic maps require time and expertise in cartography. The application of Geometrics (Remote Sensing (RS) and Geographic Information Systems (GIS) and land topographic information) is necessary for drainage network delineation. In the present study, the main objective is to delineate the drainage network and basin area of the wadi Haseeb watershed from the Digital Elevation Model (DEM) using the HEC-GeoHMS tool. The DEM of 10 m resolution is processed to define the primary natural flow routes and catchment. The hydrological analysis is performed for fill, flow direction, flow accumulation, stream definition, and finally, catchment delineation using the HEC-GeoHMS tool. Results show that the watershed was divided into four sub-basins (W240 - W270 - W410 - W420), the length of the catchment is 40 km, the watershed area was approximately 170 ha and the watershed slope was 0.9.

ABSTRACT
Aim: To investigate the cardiotoxic effect of aqueous extract of D. guineense stem bark in Wistar rats. Materials and Methods: Wistar rats (n = 35) weighing 160 to 180 g were randomly assigned to seven groups (5 rats per group). One group served as control, while rats in the remaining groups received varied doses of extract (200 - 5000 mg/kg body weight, bwt) for 28 days. Indices of cardiac function were measured. Results: Percentage increases in body weights of rats treated with aqueous extract of D. guineense stem bark were significantly reduced, relative to the control group (p < 0.05), but there were no significant differences in the relative heart weights among the groups (p > 0.05). Treatment with the extract did not elicit any significant differences in the activities of lactate dehydrogenase (LDH), creatine kinase (CK) and aspartate aminotransferase (AST) as well as cardiac malondialdehyde (MDA) level among the groups (p > 0.05). In all instances, the basal activities of the measured indices of cardiac function were not significantly different from the values after treatment (p > 0.05). Moreover, the extract did not significantly alter the normal architecture of rat heart. Conclusion: Aqueous extract of D. guineense stem bark is not toxic to the heart and could be included in herbal medicine for the treatment of diseases.

ABSTRACT
The issue of "illegal" artisanal gold mining is a concern for the state of Côte d'Ivoire. To resolve this phenomenon, measures ranging from awareness-raising to the creation of repression brigades have been taken. Despite these actions, the practice remains. This paper aims to analyse the factors that explain the persistence of 'illegal' artisanal mining in rural Côte d'Ivoire, based on a case study of the sub-prefecture of Hiré, an area where the practice of 'illegal' artisanal mining is developing asymmetrically to that of legal exploitation. The study is essentially qualitative. For data collection, interviews were conducted with different groups of actors who participate in the production system in artisanal mining. The results of the study show that the persistence of artisanal mining is the result of a social innovation that has emerged territorially by establishing itself while leading to a social transformation.

ABSTRACT
Okra (Abelmoschus esculentus) is one of the main plants of high nutritional importance cultivated in Cameroon. However, its production is compromised by many constraints including the presence of insect pests, which are responsible for losses in the farms. The present study was carried out on the campus of the University of Yaoundé I. Its objective was to evaluate the insecticidal potential of Jatropha curcas seed extracts on the insect pests of okra. Two varieties of okra (Clemson and Hire) were used. Five treatments (T0: control, T +: Lamida gold 90EC insecticide, T-EAQ: treatment with the aqueous extract of J. curcas seeds, T-EAC: treatment with acetone extract of J. curcas seeds, T-E EAE: treatment with ethyl acetate extract of J. curcas seeds) were used in a completely randomized block design with three repetitions. Growth parameters, the number of insects, severity of phyllophages and fruit yield were evaluated. The results showed that a treatment and varietal effect was observed statistically significant on all growth parameters. The pests identified were: Aphis gossypii, Cheilomenes sp, Dydercus spp., Nisotra spp., Podagrica spp., Zonocerus variegatus. Aqueous and organic extracts of Jatropha curcas seeds were effective as Lamida gold insecticide against phyllophages in compared to the control. The best yield was obtained in T-EAQ treatment (9945.45), followed by T+ (8917.31), T-EAE (6712.9) and T-EAC (6149.9) compared to control T0 (4791.3). Variety V2, although having a susceptibility to insect attack, presented the highest yield (7158.9 kg/ha) compared to (6503.78kg/ha) for V1. Aqueous and organic extracts of J. curcas seeds appear to be a promising avenue in the integrated control of okra pests. Therefore, they can be valorized.