Assessment of fertility status of soils used for cassava production in Owerri, Area of Imo State, Nigeria

The fertility status of soils used for cassava production in Owerri area of Imo State Nigeria was assessed. Composite samples were collected from ten different sites at 0-15 cm and 15 -30 cm depth. Soil samples were prepared and analyzed in the laboratory using standard methods. Data generated were statistically analyzed using the co-efficient of variation and standard deviation. Results showed that the soils varied from sandy loam to sandy clay loam and strongly acidic (mean pH. 5.68). Apart from base saturation which is high. 77.93 g/kg (0-15cm) 79.18 g/kg (15- 30 cm) other parameters were low in organic matter (OM) 1.05% (0-15 cm), 1.21% (15.30 cm), total nitrogen (N) 0.09 % (0.15 cm), 0.11 % (15-30 cm), exchangeable potassium (k), 0.19 cmoI/kg (0-15cm), 0-23 cmol/kg (15-30 cm), available phosphorus (p) 12.95 mg/kg (0-15 cm), 17.46 mg/kg (15-30 cm) Calcium (ca) 2.49 cmol/kg (0-15cm), 3.31 cmol.kg (15-30 cm), Magnesium (mg) 1.39 cmol/kg (0-15 cm), 2.10 cmol/kg), Sodium (Na) 0.13 cmol/kg (0-15 cm), 0.16 cmol/kg (15-30 cm). The result indicates that the fertility status of the study area is low and requires intensive fertility restoration programme for soil health improvement. To boast high crop yields, and productivity of cassava in the study area, a combination of organic and inorganic fertilizers are recommended.Keywords: soils, fertility status, soil productivity, cassava yields, Owerr

Assessment of fertility status of soils under land use types in Egbema Area, Imo State, Nigeria

The study was conducted to investigate fertility status under four different land use types (oil palm plantation, pineapple orchard, cassava cultivated land and fallow land use system) in Umuekem, Ohaji/Egbema of Imo State, Nigeria. Composite samples were collected from various depths (10-15cm, 15-30cm, 30-45cm) across these land use patterns and analyzed in the laboratory using the standard procedure. Data generated were subjected to statistical analysis. Results obtained showed significant differences (p ≥ 0.05) in silt-clay ratio, bulk density, total porosity, water holding capacity, soil pH, organic carbon, available phosphorus, TN and ECEC across the four land use types studied. The soils were predominantly loamy sand surface and sandy clay loam in the subsoil exception of pineapple orchard with sandy loam topsoil over sandy clay loam subsoil. The silt clay ratio (SCR) showed ranges of 0.10-0.30, 0.10-0.36, 0.07 – 0.30, and 0.06- 0.20 in land use types of oil palm plantation, pineapple orchard, cassava cultivated land and fallow land respectively. The bulk density ranged of (1.61 – 1.77 g/cm3) for oil palm, (1.34 – 1.58 g/cm3) for pineapple (1.42 – 1.49 g/cm3) cassava and (1.45 – 1.48 g/cm3) in forest land use system. The soils of the four land use types were generally acidic. The mean values of soil pH (H20) were oil palm plantation (5.11), pineapple orchard (5.03), cassava cultivated land (5.35) and fallow land (5.40). The soil pH recorded low variation in all the land use types. The organic carbon and total nitrogen recorded high variation (>52.57% < 85.67%, >79.19 < 95.77) in all the different land use types. Calcium-magnesium ratio (Ca: Mg) recorded high variation (37.36%) in forest land use system, low variation (18.77%) in pineapple orchard and moderate in cassava (27.51%) and oil palm plantation (28.23). The low Ca: Mg ratio inhibits uptake and causes Ca deficiency thereby resulting in low fertility status of the soil. C: P recorded high variation (≥ 53.77% ≤ 77.73%) in all the studied land use types. O.C correlated positively and highly significant with available phosphorus, ECEC and T.N. The findings also indicated that bulk density correlated positively with ECEC and percentage base saturation. It is recommended that land use approach should be adopted for effective and sustainable management of the soil fertility. Keywords: Fertility status, Soils, Land use type

Probing the Scope of Self Defense in International Law

The concept of self defense is one field of international law that has generated, and continues to generate, much controversy. The controversy is not as to the legality of self defense, but rather springs from a proper identification of the circumstances under which it applies. Thus, the International Court of Justice and other tribunals have received criticisms from states and academics for a perceived misapplication of the principle of self defense. The interpretation of the concept, like other important concepts in international law, has not been free from political considerations. Does this situation imply that the boundaries of self defense are as yet to be determined or cannot be determined? This work is set to delineate the scope of self defense in international law. It examines the various aspects of self defense and exposes the myriads of controversies surrounding this concept that could make or mar the efforts at international peace and security. This work will argue that the doctrine of anticipatory self defense cannot be inferred from a reading of Article 51 of the United Nations Charter. The article is divided into five parts. The first part traces the origin of the doctrine of self defense from the period pre-dating the twentieth century up to the League of Nations and moves to the era of the United Nations Charter. It also highlights the concept of just and unjust war. Part two gives attention to the general rule which prohibits the use of force by states. This rule is found in the provision of Article 2(4) of the Charter of the United Nations. It explains the problems that arise from the variegated interpretations given to some of the words used in that provision. Part three discusses the two regimes of self defense: customary international law and the UN Charter. It attempts to show the relationship between them and explains the various situations in which claims to the right of self defense may be raised. The principle of anticipatory self defense, which is a current problem arising from the nuances ascribed to the doctrine of self defense, forms the core of part four. This part also delves into the debate between advocates of a restricted interpretation of Article 51 of the UN Charter, on the one hand, and proponents of its liberal interpretation, on the other hand - a debate that has consumed too much space in the literature of international law. Part four terminates with some discussion on the preemptive doctrine, a relatively new, but controversial aspect of the doctrine of self defense. Part five is devoted to collective self defense. It explores some of the findings of the International Court of Justice in the Nicaragua case as they relate to collective self defense. A conclusion follows. The article finds that Article 51 of the Charter of the United Nations is limited to situations of armed attacks and does not admit of an exercise of the right of self defense to ward off an imminent or future attack. It also concludes that the Caroline incident does not offer a clear, incontestable ground upon which to found the right to anticipatory self defense in international law and that even though some states have invoked it under customary international law, there is no sufficient indication that that regime of law recognizes anticipatory self defense

The Place of Treaties in International Investment

This paper is divided into seven parts. Part 1 traces the history of foreign investment treaties and provides the factors that led to the emergence of the current investment regime. Part 2 discusses the significance of treaties in the vexed question of whether or not there is a hierarchy of international law sources. Part 3 examines treaty-making in the current international investment regime – visiting the argument about whether or not the provisions of investment treaties have ripened into customary international law, highlighting the dominance of bilateral investment treaties over multilateral investment treaties, offering explanation for the near absence of multilateral investment treaties in the current investment treaty regime, and noting the legitimacy problem that arises from inconsistent decisions of arbitral tribunals. The general bindingness of treaties under international law is explored in Part 4, while Part 5 considers the exceptions to the rule that treaties are binding on the parties. Part 6 focuses on the benefits and criticisms of Investment Treaties. This paper concludes that international investment treaties have brought some much-needed certainty to the terms regulating the investment relations between the foreign investor and the host State. Cite as: 19 Annl. Survey Int\u27l. Comp. L. 155 (2013)

Electrochemical determination of gallic acid in food matrices using novel materials.

Gallic acid (GA), as an endogenous polyphenol, has shown many different important properties that have influenced its use in the food and pharmaceutical industry. These properties include its antioxidant, anti-cancer, anti-tumor, anti-HIV and anti-ulcerogenic activities. The most commonly used GA determination techniques have been the spectrophotometric and chromatographic techniques. However, these techniques have shown some drawbacks; they are expensive, labour intensive, time-consuming and are not suitable for in-situ measurements. Electrochemical methods using cyclic voltammetry (CV) and differential pulse voltammetry (DPV) at inert glassy carbon electrode (GCE) or carbon paste electrodes (CPE) have also been used in the determination of GA. However, despite their easy application and fast result generation, their sensitivity and selectivity have been relatively inadequate for the analysis of GA found in beverages and pharmaceutical products. The aim of this study is therefore to investigate and develop novel nanomaterials-based electrochemical sensors for determination and analysis of GA that is fast, sensitive, cost-effective and selective. In this study, the detection of GA in red and white wines was achieved using CV, through the development of carbon-based working electrodes modified with graphene oxide nanoparticles and other metal oxide nanoparticles. The synthesised metal oxide nanoparticles were characterised using scanning electron microscopy (SEM), energy-dispersive X-ray spectroscopy, Fourier transform infrared spectroscopy and Zetasizer (for particle size analysis). Meanwhile, characterisation of the developed electrodes was carried out using CV, DPV and electrochemical impedance spectroscopy. The electrochemical effects of the electrodes were analysed. This thesis presents the results of a novel graphene oxide nanocolloids-SiO2 nanoparticles combination used for the electrochemical determination of GA. The results show enhanced peak currents, with high sensitivity and selectivity. The anodic peak current was enhanced from 241 µA (for the bare GCE) to 411 µA (for the modified GCE) - with a limit of detection (LOD) of 2.09 x 10-6 mol L-1, within a concentration range of 6.25 x 10-6 to 1.0 x 10-3 mol L-1. The thesis also proposes that there is a synergistic effect between SiO2 nanoparticles and graphene oxide nanocolloids in the determination of GA. Synthesised amorphous zirconium oxide nanoparticles were used for the modification of a carbon paste electrode and used for the determination of GA. The electrode modification enhanced the electrochemical activity of GA, with increased sensitivity and selectivity. The modified electrode produced an enhanced anodic peak from 260 µA (for the bare electrode) to 451 µA (for the modified electrode) - with an LOD of 1.24 x 10-7 mol L-1, within a range of 1 x 10-6 to 1.0 x 1 x 10-3 mol L-1. The thesis additionally makes a novel proposal for the interaction and effect of the amorphous zirconia nanoparticles on the graphite in the CPE. Zinc oxide nanoparticles and cobalt oxide nanoparticles were also used individually for the modification of carbon paste electrodes. The modified electrodes showed an enhanced effect on GA oxidation. This enhanced effect was an increase in anodic peak current from 261 µA to 414 µA, when the CPE was modified. The LOD produced by the ZnO nanoparticles-modified CPE was 1.86 x 10-7 mol L-1, within a concentration range of 1 x 10-3 to 5 x 10-2 mmol L-1. Meanwhile, the effect of scan rate and the effect of pH show that the electrodes were more effective in acidic pH, and that the GA-electrode interaction was an adsorption-controlled process. Cobalt oxide nanoparticles were also synthesised, characterised and used for the modification of CPE. The modified electrode produced an enhanced anodic peak current from 302 µA (for the bare CPE) to 404 µA (for the modified electrode). The LOD of the modified electrode was studied and found to be 1.52 x 10-6 mol L-1, at a concentration range of 1 x 10-4 to 1 x 10-3 mol L-1. The modified electrodes were successfully used for the determination of GA in real samples of red and white wine. Based on the electrochemical activities of the different electrodes made, the Zirconium dioxide nanoparticles-modified carbon paste electrode seems to have produced the best results. The zirconium dioxide-modified CPE showed increased sensitivity and better limit of detection for GA

Probing the Scope of Self Defense in International Law

The concept of self defense is one field of international law that has generated, and continues to generate, much controversy. The controversy is not as to the legality of self defense, but rather springs from a proper identification of the circumstances under which it applies. Thus, the International Court of Justice and other tribunals have received criticisms from states and academics for a perceived misapplication of the principle of self defense. The interpretation of the concept, like other important concepts in international law, has not been free from political considerations. Does this situation imply that the boundaries of self defense are as yet to be determined or cannot be determined? This work is set to delineate the scope of self defense in international law. It examines the various aspects of self defense and exposes the myriads of controversies surrounding this concept that could make or mar the efforts at international peace and security. This work will argue that the doctrine of anticipatory self defense cannot be inferred from a reading of Article 51 of the United Nations Charter. The article is divided into five parts. The first part traces the origin of the doctrine of self defense from the period pre-dating the twentieth century up to the League of Nations and moves to the era of the United Nations Charter. It also highlights the concept of just and unjust war. Part two gives attention to the general rule which prohibits the use of force by states. This rule is found in the provision of Article 2(4) of the Charter of the United Nations. It explains the problems that arise from the variegated interpretations given to some of the words used in that provision. Part three discusses the two regimes of self defense: customary international law and the UN Charter. It attempts to show the relationship between them and explains the various situations in which claims to the right of self defense may be raised. The principle of anticipatory self defense, which is a current problem arising from the nuances ascribed to the doctrine of self defense, forms the core of part four. This part also delves into the debate between advocates of a restricted interpretation of Article 51 of the UN Charter, on the one hand, and proponents of its liberal interpretation, on the other hand - a debate that has consumed too much space in the literature of international law. Part four terminates with some discussion on the preemptive doctrine, a relatively new, but controversial aspect of the doctrine of self defense. Part five is devoted to collective self defense. It explores some of the findings of the International Court of Justice in the Nicaragua case as they relate to collective self defense. A conclusion follows. The article finds that Article 51 of the Charter of the United Nations is limited to situations of armed attacks and does not admit of an exercise of the right of self defense to ward off an imminent or future attack. It also concludes that the Caroline incident does not offer a clear, incontestable ground upon which to found the right to anticipatory self defense in international law and that even though some states have invoked it under customary international law, there is no sufficient indication that that regime of law recognizes anticipatory self defense

Culture-dependent characterization of hydrocarbon utilizing bacteria in selected crude oil-impacted sites in Bodo, Ogoniland, Nigeria

This investigation was carried out to characterize microbial communities in selected crude oil polluted sites in Bodo community, Gokana Local Government Area of Rivers State, Nigeria. Total heterotrophic bacterial counts ranged from 0.7 to 1.37x107 cfu/g and 0.2 to 5.9x106 cfu/ml while counts of hydrocarbon utilizing bacteria ranged from 0.1 to 8.0 x 106 and 0.2 to 7.5 x 105 cfu/ml for soil, sediment and water, respectively. Physiochemical parameters of all samples were determined. The ranges obtained were temperature 31-33°C, pH 7.5-8.2, conductivity 1134 - 7680 μs/cm, total nitrogen 792.4 - 886.3 mg/kg, nitrate 36.55 - 42.70 mg/kg, total organic carbon 2.06 - 2.18%, total petroleum hydrocarbon 1007 - 1104 mg/kg, vanadium 0.001 - 0.007 mg/kg, iron 3.772 - 4.889 mg/kg, chromium 52.40 - 66.20 mg/kg, nickel 40.02 - 41.62 mg/kg, lead 17.30 - 19.40 mg/kg and zinc 35.10 - 39.50 mg/kg for soil and sediments while water had total nitrogen 868 mg/l, nitrate 40.6 mg/l, total organic carbon 3.1 mg/l, total petroleum hydrocarbon 768 mg/l, nickel 39.2 mg/l, lead 17.3 mg/l and turbidity 250 NTU. Bacteria isolates characterized belonged to these genera Bacillus, Proteus, Pseudomonas, Flavobacterium, Corynebacterium, Serratia, Micrococcus, Klebsiella, Enterobacter and Azotobacter. The findings reveal that there is a high population of active indigenous hydrocarbon utilizing bacteria which can be monitored and enhanced to bring about bioremediation in the study area.Key words: Hydrocarbon pollution, soil, water, sediments, hydrocarbon utilizing bacteria, Bodo, Ogoniland

The Effect of Flagella Stiffness on the Locomotion of a Multi-Flagellated Robot at Low Reynolds Environment

Microorganisms such as algae and bacteria move in a viscous environment with extremely low Reynolds ($Re$), where the viscous drag dominates the inertial forces. They have adapted to this environment by developing specialized features such as whole-body deformations and flexible structures such as flagella (with various shapes, sizes, and numbers) that break the symmetry during the motion. In this study, we hypothesize that the changes in the flexibility of the flagella during a cycle of movement impact locomotion dynamics of flagellated locomotion. To test our hypothesis, we developed an autonomous, self-propelled robot with four flexible, multi-segmented flagella actuated together by a single DC motor. The stiffness of the flagella during the locomotion is controlled via a cable-driven mechanism attached to the center of the robot. Experimental assessments of the robot's swimming demonstrate that increasing the flexibility of the flagella during recovery stroke and reducing the flexibility during power stroke improves the swimming performance of the robot. Our results give insight into how these microorganisms manipulate their biological features to propel themselves in low viscous media and are of great interest to biomedical and research applications

Prevalence and perceived health effect of alcohol use among male undergraduate students in Owerri, South-East Nigeria: a descriptive cross-sectional study

<p>Abstract</p> <p>Background</p> <p>Alcohol use during adolescence and young adulthood remains a prominent public health problem. Despite growing problems of global alcohol abuse, accurate information on the prevalence and pattern of use in Nigeria remain sparse. This study examines the prevalence and perceived health effects of alcohol use among undergraduate students in Owerri, Nigeria.</p> <p>Method</p> <p>The prevalence and perceived health effects of alcohol was estimated for 482 male undergraduates of four higher institutions in Owerri, South-East Nigeria between October 2008 and March 2009. Information was obtained using a semi-structured, self-administered questionnaire.</p> <p>Result</p> <p>The mean age of the students was 24.7 years. Majority of the respondents confirmed they were current users of alcohol given a prevalence of 78.4%, with twenty-seven percent of them being heavy drinkers (≥4 drinks per day). Reasons given by respondents for alcohol drinking include: makes them feel high (24.4%); makes them belong to the group of "most happening guys" on campus (6.6%); makes them feel relaxed (52.6%) while (16.4%) drinks it because their best friends do. Perceived health impacts of alcohol use among current users include: it enhances pleasure during moment of sex (51.1%), causes drowsiness and weakness (63.8%), may precipitate defective memory and impaired perception (64.3%) and serves as risk factor for most chronic diseases (68.5%).</p> <p>Conclusion</p> <p>High prevalence of alcohol use was established among study groups. Evaluation of full-scale community-level intervention, including community mobilisation and media advocacy aimed at supporting changes in policies on drinking, access and sales of alcohol to young people, could be helpful in reducing the trend.</p

Characterization of hydrocarbon utilizing bacteria in tropical marine sediments

Hydrocarbon utilizing bacteria present in Nembe waterside sediments, a marine habitat in Port Harcourt, Nigeria, were characterized using standard culture dependent techniques. The sediment samples were collected along the navigational route with an Eckman sediment grab (Wild Life Supply Co., NY). The samples had meant total heterotrophic bacterial count of 6.6 × 107cfu g-1 and hydrocarbon utilizing bacteria of 8.22 × 102 cfu g-1. The hydrocarbon utilizing bacteria isolated and identified belonged to the following genera; Bacillus, Nocardia, Staphylococcus, Pseudomonas, Flavobacterium, Escherichia, Acinetobacter and Enterobacter. Bacillus spp. were the most isolated followed by Pseudomonas spp. Gas chromatographic analysis of the sediment sample showed a total petroleum hydrocarbon concentration of 102.02 mg kg-1 and presence of higher chain hydrocarbons like C14, C16, C18 and C28. Species of the bacteria isolated are known hydrocarbon  degraders and it is assumed that the genera identified from the sediment may have the catabolic capability to use petroleumhydrocarbons as source of carbon. Thus the marine sediments of the Niger Delta, Nigeria may habour important genera of bacteria that may have beneficial applications in petroleum microbiology