Partial Purification and Characterisation of Carboxymethyl Cellulase from Bacillus sp. Isolated from Sugar Cane Baggase (SCB) Dump Site

Carboxymethylcellulase (CMCase) was extracted from Bacillus sp. isolated from sugar cane baggase dump site. The enzyme was partially purified using ammonium sulphate precipitation and Sephadex G-200 gel and characterized at various pH and temperature values. The optimum pH of the purified enzyme was pH 6.5 and its temperature optimum was 50oC. The Michaelis-Menten constants, Km and Vmax, of the enzyme using carboxy-ethyl cellulose as substrate were found to be 5 and 0.89 μmol/min respectively.Key words: Agricultural residues; carbon sources, nitrogen sources; pH activity; temperature activit

The War on Terror and the Crisis of Postcoloniality in Africa

Back in the early 1990s when a section of the American foreign policy think tank and the intelligentsia were euphorically forecasting scenarios for the consolidation of western victory in the Cold War, James Woolsey, then head of the US Central Intelligence Agency forewarned that the widely celebrated victory and transition to the post-Cold War era was akin to the West, having slain the dragon (of Soviet threat), now living in a jungle full of poisonous snakes (Woolsey 1993). There can hardly be a better metaphoric representation of the post-9/11 projection of American power in the postcolonial world, especially in Africa. This article argues that the US-led war on terror tends to reinforce the crisis of postcoloniality in Africa by deliberately producing metaphors, images, discourses, doctrines and policies aimed at magnifying and mainstreaming terrorism scares on the turbulent politico-economic landscape of Africa, as a means to justify imperial governance and supervision. It is a project that ideologically feeds into influential transhistorical discourses and portrayal of Africa as a timespace of infantilism, requiring endless western propping and chaperoning. Evidently, African political regimes serve as satellite collaborators in the enterprise in a trajectory that the author captures within the discursive framework of postcoloniality

Natural resource rent and stakeholder politics in Africa: towards a new conceptualisation

YesThis paper critically revisits the debate on natural resource rent, curse and conflict, interrogating some of the key assumptions that have become received knowledge in extant discourses. The paper demonstrates how orthodox theories’ preoccupation with issues of resource rent and resource curse tend to be marred by slants of ahistoricity and state-centricity. Adopting a stakeholder approach to the issues of resource rent and conflict in Africa, the author argues that natural resource rents produce and attract a multiplicity of competitive stakeholders, both domestic and external, in the resource-rich states. The competition and jostling of stakeholders for access to, and appropriation of, rentier resources is too often an antagonistic process in many emerging economies that has consequences and implications for violent conflict. The paper attempts a new conceptual explanation of how natural resource rents dialectically generate stakes, stakeholders and political conflict. The paper concludes by proposing the need for the more conflict-prone African rentier states to transition to a more functional state model, the transformative state

Natural resource rent and stakeholder politics in Africa: towards a new conceptualisation

YesThis paper critically revisits the debate on natural resource rent, curse and conflict, interrogating some of the key assumptions that have become received knowledge in extant discourses. The paper demonstrates how orthodox theories’ preoccupation with issues of resource rent and resource curse tend to be marred by slants of ahistoricity and state-centricity. Adopting a stakeholder approach to the issues of resource rent and conflict in Africa, the author argues that natural resource rents produce and attract a multiplicity of competitive stakeholders, both domestic and external, in the resource-rich states. The competition and jostling of stakeholders for access to, and appropriation of, rentier resources is too often an antagonistic process in many emerging economies that has consequences and implications for violent conflict. The paper attempts a new conceptual explanation of how natural resource rents dialectically generate stakes, stakeholders and political conflict. The paper concludes by proposing the need for the more conflict-prone African rentier states to transition to a more functional state model, the transformative state

A revisit of oral and maxillofacial mortality from orofacial infections in a resource limited setting: Is there a need for a change in management protocol?

Background: Orofacial infections are communicable infections usually of odontogenic origin, they often present as rapidly spreading infection involving the fascial spaces of the head and neck. When they are not promptly and adequately intercepted, they may result in fatal outcomes. The common pathway to mortality in these patients is often airway compromise. The advent of antibiotics and improvement in quality of health care has been said to improve the success rate in the management of orofacial infections, however the findings from our setting showed that the mortality from orofacial infections have remained high.Objective: To report mortalities from patients managed for orofacial infections in our center, review our treatment protocol and ascertain the necessity for a change in management protocolDesign: A retrospective study Setting: Maxillofacial surgery department of Aminu Kano Teaching Hospital (AKTH) Kano, Kano state Nigeria.Subjects: All patients who died in our facility over a one hundred and thirty eight-month period (January 2005 – June 2016) following management of orofacial infectionsResults: A total of 115 (76 males, 39 females) maxillofacial admissions were recorded on account of orofacial infection during the period under review; of these 26 mortalities were recorded (22.6%). Male subjects constituted 19 cases while female subjects were 7 in number. The demised patients’ ages ranged from 19 years to 73 years with a mean age of 34.0 ± 12.0 years.Conclusion: Orofacial infections are potentially lethal; they constitute one of the commonest causes of mortality in maxillofacial surgery facilities. A standard care of early intervention, aggressive medical and surgical therapy has consistently provided the best results

Happiness and life satisfaction in Rwanda

This study investigated predictors of happiness and life satisfaction in Rwanda. Data from the World Values Survey and gathered from 3 030 Rwandese (age ranging 16 to 90 years, mean age = 34.2, SD = 12.7; females = 50.5%) were pooled for the analysis. For the comparison, international World Values Survey data were utilised. A fixed effects multilevel regression model was used to predict happiness and life satisfaction from gender, health, socio-economic, and some subjective measures. Males had greater self-rated happiness and life satisfaction scores than females. State of health and sense of freedom of choice predicted both happiness and life satisfaction. Valuing of friends, weekly religious attendance, and national pride positively predicted happiness, whereas household’s financial satisfaction, full-time employment, high-income group, being a student, and sense of trust predicted life satisfaction. This study suggests that health status, household’s financial satisfaction and emancipative values could maximise subjective well-being in Rwanda

Investigation of dielectric constant variations for Malaysians soil species towards its natural background dose

The correlation of natural background gamma radiation and real part of the complex relative permittivity (dielectric constant) for various species Malaysian soils was investigated in this research. The sampling sites were chosen randomly according to soils groups that consist of sedentary, alluvial and miscellaneous soil which covered the area of Batu Pahat, Kluang and Johor Bahru, Johor state of Malaysia. There are 11 types of Malaysian soil species that have been studied; namely Peat, Linau-Sedu, Selangor-Kangkong, Kranji, Telemong- Akob-Local Alluvium, Holyrood-Lunas, Batu Anam-Melaka- Tavy, Harimau Tampoi, Kulai- Yong Peng, Rengam-Jerangau, and Steepland soils. In-situ exposure rates of each soil species were measured by using portable gamma survey meter and ex-situ analysis of real part of relative permittivity was performed by using DAK (Dielectric Assessment Kit assist by network analyser). Results revealed that the highest and the lowest background dose rate were 94 ±26.28 μR hr-1 and 7 ±0.67 μR hr-1 contributed by Rengam Jerangau and Peat soil species respectively. Meanwhile, dielectric constant measurement, it was performed in the range of frequency between 100 MHz to 3 GHz. The measurements of each soils species dielectric constant are in the range of 1 to 3. At the lower frequencies in the range of 100 MHz to 600 MHz, it was observed that the dielectric constant for each soil species fluctuated and inconsistent. But it remained consistent in plateau form of signal at higher frequency at range above 600 MHz. From the comparison of dielectric properties of each soil at above 600 MHz of frequency, it was found that Rengam-Jerangau soil species give the highest reading and followed by Selangor-Kangkong species. The average dielectric measurement for both Selangor-Kangkong and Rengam-Jerangau soil species are 2.34 and 2.35 respectively. Meanwhile, peat soil species exhibits the lowest dielectric measurement of 1.83. It can be clearly seen that the pattern of dielectric measurement for every soil at the frequency above 600 MHz demonstrated a specific distribution which can be classified into two main regions which are higher and lower between the ranges of 1.83 to 2.35. Pearson correlation analysis between the frequency of 100 MHz and 2.6 GHz with respect to exposure rate for every soil species was r = 0.38 and r = 0.51, respectively. This indicates that there was no strong correlation between both parameter, natural background dose and soils dielectric for each soils sample. This factor could be contributed by major and minor elements contained in each soils sample species, especially Ferum, Fe and Silica, Si

The enhancement of heavy metal removal from polluted river water treatment by integrated carbon-aluminium electrodes using electrochemical method

The heavy metal removal enhancement from polluted river water was investigated using two types of electrodes consist of integrated carbon-aluminium and a conventional aluminium plate electrode at laboratory-scale experiments. In the integrated electrode systems, the aluminium electrode surface was coated with carbon using mixed slurry containing carbon black, polyvinyl acetate and methanol. The electrochemical treatment was conducted on the parameter condition of 90V applied voltage, 3cm of electrode distance and 60 minutes of electrolysis operational time. Surface of both electrodes was investigated for pre and post electrolysis treatment by using SEM-EDX analytical technique. Comparison between both of the electrode configuration exhibits that more metals were accumulated on carbon integrated electrode surfaces for both anode and cathode, and more heavy metals were detected on the cathode. The atomic percentage of metals distributed on the cathode conventional electrode surface consist of Al (94.62%), Zn (1.19%), Mn (0.73%), Fe (2.81%) and Cu (0.64%), while on the anode contained O (12.08%), Al (87.63%) and Zn (0.29%). Meanwhile, cathode surface of integrated electrode was accumulated with more metals; O (75.40%), Al (21.06%), Zn (0.45%), Mn (0.22), Fe (0.29%), Cu (0.84%), Pb (0.47%), Na (0.94%), Cr (0.08%), Ni (0.02%) and Ag (0.22%), while on anode contain Al (3.48%), Fe (0.49 %), C (95.77%), and Pb (0.26%). According to this experiment, it was found that integrated carbon-aluminium electrodes have a great potential to accumulate more heavy metal species from polluted water compare to the conventional aluminium electrode. Here, heavy metal accumulation process obviously very significant on the cathode surface

Risk assessment of human exposure to radionuclides and heavy metals in oil-based mud samples used for drilling operation

This study investigates heavy metals and naturally occurring radionuclide materials (NORM) possible presence and pollution rates in oil-based drilling fluids system used to drill an oil and gas well. It also estimates the health risks of the drilling crew due to their exposure to these substances. Measurements from Atomic Absorption Spectrometry (AAS) revealed that, the concentrations of the metals present in the drilling mud samples varied significantly and decreased in the order of Zn > Al > Ni > Pb > Cr > Cu > As > Hg > Cd. Generally, amongst all the heavy metals considered, mud sample C had the highest heavy metal concentration when compared to samples A and B, respectively. When compared with the recommended maximum allowable limits, Cd and Ni were found to be higher than the International Reference Standard by factors of Cd (3 mg/kg) and Ni (50 mg/kg). The cancer risk obtained from this present study are 1.1 × 10−3 and 7.7 × 10−3 for the drilling crew, which is slightly above the acceptable risk range considered by the environmental and regulatory agencies. The concentrations of radioactive substances as obtained from analysis, show that K-40 is the dominant radionuclide in the samples with the highest value slightly twice the standard reference value. The concentrations of Ra-226 and Th-232 activity in the mud samples were found to be lower when compared with the International Reference Level. Also, the Xray diffraction analysis helped to identify 16 very important/useful minerals in the three mud samples under consideration. The higher elemental concentrations of potassium and aluminum silicate found in sample C can be credited to the elevated heavy metalcontent found in the mud samples. Significantly, these exposure risks found in this present study indicate that the potential health risks due to radiological activities may not pose short – but long-term risks to the drillers

Risk assessment of human exposure to radionuclides and heavy metals in oil-based mud samples used for drilling operation

This study investigates heavy metals and naturally occurring radionuclide materials (NORM) possible presence and pollution rates in oil-based drilling fluids system used to drill an oil and gas well. It also estimates the health risks of the drilling crew due to their exposure to these substances. Measurements from Atomic Absorption Spectrometry (AAS) revealed that, the concentrations of the metals present in the drilling mud samples varied significantly and decreased in the order of Zn > Al > Ni > Pb > Cr > Cu > As > Hg > Cd. Generally, amongst all the heavy metals considered, mud sample C had the highest heavy metal concentration when compared to samples A and B, respectively. When compared with the recommended maximum allowable limits, Cd and Ni were found to be higher than the International Reference Standard by factors of Cd (3 mg/kg) and Ni (50 mg/kg). The cancer risk obtained from this present study are 1.1 × 10−3 and 7.7 × 10−3 for the drilling crew, which is slightly above the acceptable risk range considered by the environmental and regulatory agencies. The concentrations of radioactive substances as obtained from analysis, show that K-40 is the dominant radionuclide in the samples with the highest value slightly twice the standard reference value. The concentrations of Ra-226 and Th-232 activity in the mud samples were found to be lower when compared with the International Reference Level. Also, the Xray diffraction analysis helped to identify 16 very important/useful minerals in the three mud samples under consideration. The higher elemental concentrations of potassium and aluminum silicate found in sample C can be credited to the elevated heavy metalcontent found in the mud samples. Significantly, these exposure risks found in this present study indicate that the potential health risks due to radiological activities may not pose short – but long-term risks to the drillers