EFFECT OF TILLAGE METHODS ON SOIL PHYSICAL AND STRENGTH PROPERTIES UNDER AMARANTHUS HYBRIDUS PRODUCTION IN A SANDY-LOAM ENVIRONMENT

Amaranthus hybridus (African Spinach) production is a common vegetable in many southwestern parts of Nigeria. Many farmers grow it for its high source of protein and vitamins under different soil conditions without taking into consideration the tillage method that best gives the highest yield. A field study was conducted on a sandy loam soil in the National Centre for Agricultural Mechanization, Ilorin. Nigeria during the raining season of 2017 to investigate the effect of tillage methods on soil physical properties, penetration resistance and shear strength under Amaranthus hybridus production. The experiment was a completely randomized design with three replications. Tillage methods were disc plough (DP), disc harrow (DH), combination of disc plough and disc harrowing (DPH) and zero tillage (ZT). Soil physical parameters investigated during the growth stages of the crop were soil bulk density, soil moisture content, penetration resistance, shear stress and total porosity. Average bulk density for DP, DPH, DH and ZT were 1.33, 1.30, 1.25 and 1.50 g/cm3 respectively. Shear stress increased with depth in all the plots. Maximum values at the 14-21 cm depth were 132, 104, 166 and 16 mPa for DP, DPH, DH and ZT respectively. The average penetration resistance on the DP, DPH, DH and ZT at the 14-21cm depth were 84.3, 82, 178 and 97 kPa respectively. Amaranthus hybridus yield was highest on the DPH plots with an average weight of 10 stands weighing 108g.  Disc ploughed + harrowing was the best tillage practice considering the soil physical properties, penetration resistance and shear stress of the plots for the optimum yield of Amaranthus hybridus on the sandy loam field

Adaptive Load Frequency Control of Nigerian Hydrothermal System Using Unsupervised and Supervised Learning Neural Networks

This work presents a novel load frequency control design approach for a two-area power system that relies on unsupervised and supervised learning neural network structure. Central to this approach is the prediction of the load disturbance of each area at every minute interval that is uniquely assigned to a cluster via unsupervised learning process. The controller feedback gains corresponding to each cluster center are determined using modal control technique. Thereafter, supervised learning neural network (SLNN) is employed to learn the mapping between each cluster center and its feedback gains. A real time load disturbance in either or both areas activates the appropriate SLNN to generate the corresponding feedback gains. The effectiveness of the control framework is evaluated on the Nigerian hydrothermal system. Several far-reaching simulation results obtained from the test system are presented and discussed to highlight the advantages of the proposed approach

Utilisation of alicyclic compounds by soil bacteria

Alicyclic compounds are recalcitrant hydrocarbons, they are a major component of crude oil and their fraction in the oil may be as high as 37%. They are used as industrial chemicals and are obtained via extraction from petroleum or by synthesis. A number of alicyclic compounds are, in addition to the petrogenic source, continually synthesized biologically as constituents of plants and microorganisms. Despite the wide occurrence of these compounds in nature, very little works had been carried out on their utilization by microorganisms. Species of Pseudomonas, Acinetobacter, Arthrobacter and Nocardia able to utilize cyclohexanone as sole carbon source were isolated from soil by enrichment technique. The isolates also grew on cyclohexanol, succinic and acetic acids as sole carbon sources. DNA profiles of the organisms did not reveal the presence of any plasmid. Growth in acriflavin-supplemented broth did not result in loss of ability to utilize the compounds. The genetic control of alicyclic metabolism in these organisms appeared to be chromosomal in nature. [Nature and Science. 2006;4(3):65-68]

Dependencia de la viscosidad de cizalladura en la concentración depseudo plasticidad (oxido de polietileno - xantano) colisión de polímero

Introduction: Its necessary to bear in mind that we life in theword increase industrialization, therefore we make many modifications to material to getting on best characterizations. The aim ofthis research is to Prepare new Pseudo Plasticity Polymer Collide.Materials and Methods: In the present paper effects of xanthancellulose gum (X) on rheological properties of polyethylene oxidepolymer (PEO, 3000 Daltons) included different type of viscosityhas been investigated by using the following parameters: (Spindle:no.1, Speed: 60 rpm and Temperature: RT), different sort of viscosity is computed for a PEO that dissolved in distilled cold waterwith completely different various concentrations (0.1, 0.2 to 0.8)%g/mL once and before adding (0.25 and 0.5) g X for every concentration. Results and Discussion: The results show that all properties of density, shear viscosity, relative viscosity, specific viscosity,reduced viscosity, intrinsic viscosity, viscosity average mass and theeffective molecular radius have been enhanced after the addition ofxanthan. Conclusions: Addition of xanthan are often applied asthicker mixture in coating, oil drilling and pumping of fluids attributable related pseudo physical propert

Detection of trypanosomes in small ruminants and pigs in western Kenya: important reservoirs in the epidemiology of sleeping sickness?

BACKGROUND: Trypanosomosis is a major impediment to livestock farming in sub-Saharan Africa and limits the full potential of agricultural development in the 36 countries where it is endemic. In man, sleeping sickness is fatal if untreated and causes severe morbidity. This study was undertaken in western Kenya, an area that is endemic for both human and livestock trypanosomosis. While trypanosomosis in livestock is present at high levels of endemicity, sleeping sickness occurs at low levels over long periods, interspersed with epidemics, underscoring the complexity of the disease epidemiology. In this study, we sought to investigate the prevalence of trypanosomes in small ruminants and pigs, and the potential of these livestock as reservoirs of potentially human-infective trypanosomes. The study was undertaken in 5 villages, to address two key questions: i) are small ruminants and pigs important in the transmission dynamics of trypanosomosis? and ii), do they harbour potentially human infective trypanosomes? Answers to these questions are important in developing strategies for the control of both livestock and human trypanosomosis. RESULTS: Eighty-six animals, representing 21.3% of the 402 sampled in the 5 villages, were detected as positive by PCR using a panel of primers that identify trypanosomes to the level of the species and sub-species. These were categorised as 23 (5.7%) infections of T. vivax, 22 (5.5%) of T. simiae, 21 (5.2%) of the T. congolense clade and 20 (5.0%) of T. brucei ssp. The sheep was more susceptible to trypanosome infection as compared to goats and pigs. The 20 T. brucei positive samples were evaluated by PCR for the presence of the Serum Resistance Associated (SRA) gene, which has been linked to human infectivity in T. b. rhodesiense. Three samples (one pig, one sheep and one goat) were found to have the SRA gene. These results suggest that sheep, goats and pigs, which are kept alongside cattle, may harbour human-infective trypanosomes. CONCLUSION: We conclude that all livestock kept in this T. b. rhodesiense endemic area acquire natural infections of trypanosomes, and are therefore important in the transmission cycle. Sheep, goats and pigs harbour trypanosomes that are potentially infective to man. Hence, the control of trypanosomosis in these livestock is essential to the success of any strategy to control the disease in man and livestock

Anatomical features of renal artery in a black Kenyan population: Correlation with markers of atherosclerosis

Knowledge of anatomical features of the renal artery is important in prediction,  management and control of atherosclerotic renal artery stenosis. These features show population variations but data from black African populations are scarce. The aim of this study was therefore to describe the anatomical features of the renal artery in a black Kenyan population. Six hundred and ten (610) single renal arteries from 305 adult black Kenyans [206 males, 99 females; age range 22 – 79 years] were studied by dissection at Department of Human Anatomy, University of Nairobi, Kenya. Specimens with macroscopic features of stenosis and dilatation were excluded. The implantation angle, length and branching pattern were studied. These features were correlated with intima-media thickness and luminal diameter. The  latter were determined by micrometry on Eosin/hematoxylin stained 5 micron  sections obtained from the proximal segment of the renal artery. Data was analysed by SPSS version 16.0. Student’s t-test, was used to test for statistical significance at 95% confidence interval where P value of < 0.05 was taken as significant. The results are presented in a bar graph, tables and macrographs. The mean  implantation angle was 940±150 (range 580-1250). In 26.7% cases, the angle was more than 1000. Mean length was 34±1.4 mm with 21.6 % of arteries measuring ≤ 20 mm. Variant branching pattern was present in 40.5 % of cases. It comprised trifurcation (33 %), quadrifurcation (6.6 %) and pentafurcation (0.8 %). Higher implantation angle, short arteries and variant branching were associated with  statistically significant higher intima - media thickness and luminal diameter. These results suggest that higher implantation angle, shorter length and variant branching pattern constitute geometric risk factors for renal artery atherosclerosis.  Ultrasound screening for individuals with suboptimal geometric features for renal artery atherosclerosis is recommended.Keywords: anatomical risk factors, atherosclerosis, renal arter

Clinical profile of paediatric sickle cell disease at a reference hospital in North–eastern Nigeria

Background: Sickle cell disorders (SCD) are the commonest inherited haemoglobin (Hb) disorders. Globally, about 300,000 babies are born annually with these conditions. The clinical profiles of SCD have been described in many parts of the world. These however have not been adequately investigated in some parts of Nigeria. This study evaluated the clinical features, Hb phenotype and complications of children with SCD being managed at a Paediatric haematology clinic in Northern Nigeria. Methods: A prospective observational study of steady state SCD patients aged 2 – 16 years, was conducted from January, 2019  -October, 2020. Historical and examination findings were documented. Analysis of data was done with the Statistical Package for Social Sciences (SPSS) version 20.0. Results: One hundred children were studied. Mean age was 6.97 ± 3.63 years. Male: female ratio was 1.6:1.Mean weight and mean height were lower than reference standards (t= -1.20, p= 0.14), (t= - 0.66, p= 0.27) respectively. Mean age at diagnosis was 13.24 ±14.83 months, and at first presentation was 13.86 ±17.51 months, 58.5% of subjects were adequately vaccinated for age, while 92% had a Hb phenotype of SS. Acute chest syndrome occurred more frequently in children aged 9-12 years (χ2= 11.59, P ˂ 0.001), and in those with severe bacterial infections (χ2= 7.41, p= 0.006). Conclusion: The complications of Paediatric SCD in this part of North-Eastern Nigeria mirrors those in other parts of the country. Socio-economic class, Hb phenotype and vaccination status had no influence on the development of complications

ranching pattern of the left anterior descending coronary artery in a black Kenyan Population

Branching pattern of the left anterior descending coronary artery is important in explaining variations in occurrence of coronary atherosclerosis, informing management strategies for coronary heart disease and interventional cardiology. Data on African populations are, however, scarce. Since coronary heart disease is increasing in Africa, the aim of this study was to describe branching pattern of the left anterior descending coronary artery in an indigenous Kenyan population. Two hundred and eight hearts obtained during autopsy were dissected at the Department of Human Anatomy, University of Nairobi, Kenya. The entire left anterior descending coronary artery was exposed. Number of branches, pattern of termination and level of bifurcation were determined. Images of representative patterns were taken using a high resolution digital camera. Data are presented in macrographs and tables. The number of septal and diagonal branches varied between 1 and 3. Termination occurred in the posterior interventricular sulcus in 68.8% and at the apex in 23% cases. Most common mode of terminal branching was bifurcation (76.9%) followed by trifurcation (11.3%), quadrifurcation (3.4%) and pentafurcation (1.5%). Bifurcation occurred in the distal segment in 48.8% and in the proximal segment in 15% of cases. The left anterior descending coronary artery displays high variability in number of septal and diagonal branches, level of termination, mode of terminal branching and level of terminal bifurcation. These patterns may constitute risk factors for atherosclerosis and should also be acknowledged during cardiac procedures. Pre – operative ultrasound evaluation is recommended to minimize inadvertent iatrogenic injury.Keywords: Left anterior descending, branching, termination, atherosclerosi

Analysis of auto-purification response of the Apies River, Gauteng, South Africa, to treated wastewater effluent

The assimilative capacity of water bodies is an important factor in the integrated management of  surface water resources. The current study examined the auto-recovery processes of the Apies River from wastewater discharged into it from a municipal wastewater treatment facility, using a series of equations, including the modified Streeter-Phelps equation. Field data obtained include dissolved oxygen (DO), temperature, stream velocity, depth, and width. Water samples were also obtained at 10 sampling stations for the determination of biochemical oxygen demand (BOD) using standard methods. It was observed that the DO and BOD level (5.59 mg/L and 8.5 mg/L respectively) of the effluent from the wastewater treatment facility indicated better water quality than the Apies River background DO level (5.42 mg/L) and BOD level (13 mg/L). Also, at 270 m downstream of the effluent discharge point, another effluent stream (Skinnerspruit) adversely impacted on the Apies River with DO and BOD levels of 6.5 mg/L and 9.0 mg/L, respectively, compared to the Apies River background values of 6.81 mg/L and 8.0 mg/L, respectively. The stream, however, recovered well from both the background and imposed pollution sources as it had a computed positive auto-recovery factor of 1.74. Furthermore, the measured DO deficit was plotted against predicted DO deficit. The plot revealed a close match between the measured and predicted DO deficit, indicating that the model could be used for predicting DO deficit along other segments of the river. To further improve on the natural  auto-recovery processes of the Apies River, it was recommended that flow along the Skinnerspruit should be enhanced by clearing the observed aquatic plants growing within the channel. Also,  suspected pollution activities taking place further upstream on the Apies River should be investigated and appropriately addressed.Keywords: de-oxygenation; re-aeration; auto-purification; dissolved oxygen; biochemical oxygen  demand; strea