Testing for equality of means with equal and unequal variances

In this paper, we are interested in comparing the conventional t –test with the proposed t – test for testing equality of means with unequal and equal variances. Here, we proposed harmonic mean of variances as an alternative to the pooled sample variance when there is heterogeneity of variances. Two sets of secondary data were obtained from Agricultural Development Project (KWADP) and the Ministry of Agriculture in Ilorin, Kwara State to demonstrate the two test statistics used and the results show that the proposed t – test statistic is found to be appropriate than the conventional t – test statistic when we have unequal variances but the conventional t – test perform better when we have equal variances.

Neurological behaviour of albino rats treated separately and in combination with Cannabis sativa L. and Cannabis indica L.

There has been an increasing rate of cannabis consumption globally, especially among the youths. This study therefore evaluated the neurological behaviours and some brain marker hormones and enzymes of cannabis administered rats. Twenty six albino rats were divided into four groups based on oral cannabis administration (control, Cannabis sativa, Cannabis indica and the combination of the two). At the end of seven days, open field test was conducted on the rats. Also, brain neuro-chemicals, activities of antioxidant enzymes and lipid peroxidation were evaluated using spectrophotometry. The results of the Open-Field Test showed an appreciable increase in the level of ambulation (line crossing), grooming, urination and stretched attend posture in the rats administered with Cannabis indica, Cannabis sativa and the combination when compared with the control. Norepinephrine was significantly lower (p < 0.05) in the rat groups administered with the combination of Cannabis indica and Cannabis sativa. The control group however had the lowest dopamine level. Superoxide dismutase (SOD) was significantly lower (p < 0.05) in the rats administered the combination of both Cannabis indica and Cannabis sativa. The brain level of reduced glutathione (GSH) was significantly higher in the rats administered with Cannabis indica. Malondialdehyde (MDA) was significantly higher in the rats administered with Cannabis sativa than the other rat groups. Histopathological evaluation of the brain also revealed various damages in the brain cells of rats administered with cannabis compared to the normal brain structure of the control rats. It is thus said that consumption of C. sativa or C. indica alone produced mild effect on the brain cells and physiology in rats. However, combination of C. sativa and C. indica produced a severe synergistic effect on the neurological function of the exposed rat.

Ground magnetic survey for the investigation of magnetic minerals at Iboro Village, Abeokuta, south-western Nigeria

The geological map of the old western region of Nigeria indicates the presence of iron ore deposit at Iboro village Ogun state (7.9983o - 7.99933o N, 3.5790o - 3.5890o E). Hence a ground magnetic survey was carried out at a location at Iboro village so as to delineate the subsurface magnetic anomalies and to know whether the anomalies favour accumulation of magnetic minerals. The survey was carried out using high resolution proton precession magnetometer model G-856X. Eight traverses were run at 5m separations and earth magnetic intensity values were measured at 10m intervals along each traverse; the acquired data were corrected for drift. The residual anomalies obtained by removal of regional gradient from observed data using trend analysis were presented as profiles and maps. The treated data were qualitatively and quantitatively interpreted and the results gave values for the total ground magnetic anomalies that varied between a minimum and maximum peak values of about -33.0 and 30.6nT respectively. Depth to the basement rock was estimated using Peter’s half slope method which gave a maximum depth of about 13m. The contour maps and the total relative graphs present the subsurface picture of the geological structure that is assumed to harbour the metallic minerals through the action of the field towards the concentration of anomalies. It was suspected that the overburden was relatively thin in the study area and the minerals were at a shallow depth.

Synthesis of Co (ii) and Zn (ii) complexes of modified and unmodified cashew nut (Anacardium occidentals L.) shell liquid extract

Cashew nut shell liquid (CNSL) extract obtained using soxhlet extraction method with acetone as solvent has been used in the synthesis of Co (II) and Zn (II) metal complexes. The CNSL gave a molecular peak ion of 298g/mol-1 on a GC-MS, an indication that cardanol was more prominent than anacardic acid in the obtained extract. Physicochemical parameters such as saponification value (50.30 mgKOH/g), moisture content (5.10), iodine value (241.00 mgKOH/g), ash content (1.30) and pH (6.31) were equally obtained. The metal complexes of Co (II) and Zn (II) prepared with unmodified (UMCNSL) and aniline modified CNSL (AMCNSL) were characterized using UV-visible, FTIR, melting point and electrical conductivity. Some characteristic FTIR bands were observed for AMCNSL, UMCNCL, AMCNSL-ZnCl2.H2O (1612cm-1) and AMCNSL-CoCl2.6H2O (1612cm-1). The presence of C=N were confirmed in the metal complex of AMCNSL-ZnCl.H2O and AMCNSL-CoCl.6H2O but were not present in the UMCNSL-ZnCl.H2O and UMCNSL-CoCl.6H2O.

Genetic variability of spiralling whitefly Aleurodicus disperses Russell on Citrus aurantifolia Christm and Ocimum gratissimum L.

The spiralling whitefly, Aleurodicus dispersus Russell (Hemiptera: Aleyrodidae), has a wide range of anatomy, physiology, behaviour, and ecology depending on the host plant. This research looked at the genetic variations between A. dispersus populations on two separate host plants (Citrus aurantifolia and Ocimum gratissimum). The existence of host-related genetic variation in A. dispersus populations was determined using Rapid Amplification of Polymorphic DNA (RAPD) markers. Our findings revealed that the A. dispersus populations on the two host plants had a considerable amount of genetic divergence. The spiralling whiteflies on the adaxial part of Citrus aurantifolia were genetically distinct from those on the abaxial part of the same plants. Various population genetic parameters such as heterozygosity, Nei's genetic gap, and fixation indices (FST) revealed that spiralling whitefly populations vary genetically, which may be attributable to spiralling whitefly populations originating from multiple sources. These findings also have consequences for the invasive pest's quarantine safety strategy.

Investigation of the Kerr effect on polarised light

A constructed Kerr cell with brass electrodes and liquid nitrobenzene was used for studying the Kerr effect on polarised light. Laser light was plane polarised and passed through an energised Kerr cell. The plane polarised light after travelling a path length equal to the cell electrode length in a birefringent medium, suffered optical retardance before passing through an analyser which then transmitted light of certain intensity to a photodiode. Data used were generated from experiments and theoretical considerations using Kerr’s law and Malus’ law. With crossed Polaroids, the Kerr cell behaved as an electro-optic shutter and the maximum light intensity transmitted rose steadily with increased phase difference to about 0.82. With parallel Polaroids, the maximum light intensity transmitted was higher and found to be 0.89 at zero phase difference. This value indicates a large phase delay and decreased to a non-zero value. At maximum electric field intensity, a ‘climbing’ of the nitrobenzene on the Kerr cell walls and electrodes was observed with more nitrobenzene attracted to the anode. The effect suspected to be of electrostatic origin may have been driven by the predominant ions in the nitrobenzene. Furthermore, the higher level of the nitrobenzene meniscus at the anode probably suggests that while the cathode injected carriers of negative charge into the liquid the injection of carriers from the anode was weaker. For better results, attention should be given to Polaroid quality, the purity of the liquid nitrobenzene and the length of the electrodes used.

Inverse Akash distribution and its applications

A new one-parameter distribution named inverse Akash distribution, for modelling lifetime data, has been introduced. Important statistical properties of the proposed distribution such as the density function, hazard rate function, survival function, stochastic ordering, entropy measure, stress-strength reliability and the maximum likelihood estimation of the parameter of the distribution have been discussed. Two real data sets were employed in illustrating the usefulness of the new distribution. Comparatively, the inverse Akash distribution provided better fits to the data than each of the inverse exponential distribution and inverse Lindley distribution.

Haematological and histopathological examinations of African mud catfish (Clarias gariepinus) exposed to petroleum wastewater

Effects of petroleum refinery wastewater on Clarias gariepinus juvenile were investigated. Commercially obtained C. gariepinus fingerlings were acclimatized in a plastic tank (100 L capacity) of de-chlorinated tap water at 25±2°C for 14 days and fed with commercial feed pellet at 2% body weight of the fingerlings. Bioassay tests were carried out in four transparent plastics tank with nominal concentrations of 100 ml, 200 ml, 300 ml of the wastewater added to 40L of de-chlorinated tap water and only de-chlorinated tap water as control. Each tank contains twenty fish samples, while the assay was replicated three times concurrently. Following standard procedures, behavioural response, growth changes, haematological and histopathological tests were carried out on the samples. Significant reduction in the weight was observed in the fingerlings cultured with the wastewaters, while no significant difference occurred in the control fish. Highest values of Packed Cell Volume (PCV) (22), Haemoglobin (HB) (7.0), Red Blood Cell (RBC) (1.62) and endocochlear potential (EP) (5) were recorded for the control fish than exposed fish. On the other hand, Haptoglobin (HP), Mean Corpuscular Volume (MCV) and Mean Corpuscular Haemoglobin (MCH) were higher in the blood of exposed fish than in control. Histopathologically, exposed fishes showed no visible lesion in gills except from the thickening of the lamellae as the concentration of wastewater increases, indicating an increase in tissue disintegration. Similarly, gross tissue disintegration was observed in those fish exposed to 200ml wastewater as evidenced by the presence of large open spaces (hepatocytes) in the liver.

Ethnobotanical survey and proposed recipes of potential wound-healing plants in parts of south west Nigeria

Ethnobotanical survey of medicinal plants remains a veritable source of information leading to discovery of new lead compounds of pharmaceutical importance thus, the need for continual search for medicinal plants via ethnobotanical surveys in Nigeria. Structured questionnaires were administered amongst traditional healers. A few other anecdotal claims about efficacy of herbs from people who at one time or the other have used the plants for wound healing were also sampled. The result of an ethnobotanical survey of plants used in the treatment of wound in Ijebu North Local Government area of Ogun State and Ibadan North Local Government area of Oyo state of Nigeria are reported. A total of 71 species of plants covering 43 families were identified; representing 51 recipes. Carica papaya Linn, Elaeis guineensis Jacq, Chromolaena odorata Meull. Arg, Gladiolus psittacinus Hook.f., Vetivera kotschyana (Benth.) Stapf, Securidaca longipedunculata Fresen and Euphorbia laterifolia Linn were prominent among the recipes. Among all the families identified in the recipes, Euphorbiaceae was most mentioned (7.0%) followed by Compositeae, Fabacceae, Malvaceae and Meliaceae families (4.0%), Amaryllidaceae, Annonaceae, Arecaceae, Asphodeloideae, Asteraceae, Cucurbitaceae, Leguminosae, Musaceae, Poaceae, Rubiaceae, Rutaceae, Solanaceae, Sterculiaceae, Zingiberaceae followed closely (3.0%) while Acanthaceae, Amaranthaceae, Anacardiaceae and others had 1.0%. Out of the recipes, 51.9% are either leaves only or in combination with other parts, while 21.5% are stem bark, 7.6% are seeds and 3.8% are roots, bulbs and fruits respectively. These plants could be investigated for potential leads for wound healing in animal subjects.

Multi-drug resistant Aeromonas species in Annelida: An evidence of pathogen harbouring leech in recreation water nexus of Oghara Nigeria environs

Aeromonas infections have shown diverse complications in management due to the multiple antibiotic resistance observed amongst its members. The origin and habitat of its resistance development yet remain vague. The present study depicts Leech and its infested recreational water as a reservoir of multidrug-resistant Aeromonas hydrophila. Skin swabs of recreational water bathers before (Bb)/after bathing (Ab) (250 each) and 250 leeches (Hirudomedicinalis) were collected from recreational water sites. Standard Microbiological and Molecular biology methods were applied for isolation and characterization. Two hundred and forty-five (98%)Bb specimen, showed a negative growth oforganisms, 84% (210) of the Ab specimen harboured presumptive Aeromonas species, while 100% (250) Leeches specimen harboured Aeromonas species. The Polymerase Chain Reaction (PCR) of 16SrRNA gene detection confirmed all (465/100%) isolates as Aeromonas species while 13.6% (63) were further delineated as Aeromonas hydrophila. The antibiogram showed 45(97.82%) resistance to the β-lactam antibiotic and other antibiotic groups. The PCR detection of resistant markers, virulent and plasmid profile of isolates reveals conjugative plasmid mediation, lip (123/97.6%), act (104/82%), hhly (93/73%) genes and BlaampC gene, BlaTEM, gene and BlaSHV gene. Observation of pathogens with similar multiple antibiotic-resistant gene-profile both in the bathers'skin swab and gut of leeches indicates origin/habitat, association and suggests the gut of leeches as breeding habitat for the pathogen. This is an emerging public health concern that associates specifically the environment and human superficial infections.