Fisher’s Linear Discriminant Classifier And Rank Transformation Approach To Discriminant Analysis

Discriminant analysis is a multivariate statistical technique used primarily for obtaining a linear function of p variables which maximizes the distance between centroids or midpoints of multivariate distributions of k groups. Linear discriminant analysis was performed using the fisher’s technique which was also derived. Test for differences in the means for the two groups and their variance covariance matrices were discussed. A major shortcoming of the fisher’s linear discriminant analysis is that if normality assumption does not hold, the optimal property is lost. This paper compared Fisher’s linear discriminant analysis and the rank transformation approach. This was illustrated by performing discriminant analysis on the data and discriminant analysis on the ranks.  If the population is not normal, the effectiveness of this method is enhanced by using the ranks of the original data rather than the data themselves. The results obtained indicate that the two methods perform equally well but the rank transformation is a better alternative to the Fisher’s discriminant  technique  for distributions of small samples and non-normal data. Keywords Fisher’s Linear Discriminant Analysis, Rank transformation, Classification, Apparent Error Rate

Effects of urban wastes on the quality of Asata River in Enugu, south eastern Nigeria

Water samples from nine sample stations in Asata River Enugu, were analysed to determine the effects of urban wastes on the quality of the river water. Stations A- F were located in more urbanized areas of the city, while G-I were in less urbanized areas. Results of laboratory analysis show higher values of parameters( pH, turbidity, colour, conductivity, suspended solids, total dissolved solids, dissolved oxygen and biochemical oxygen demand and faecal coliform) at stations A- F than at G-I. Results of physico-chemical parameters showed values within safe limits. However, all samples failed to meet bacteriological standards. A strong degree of association was found to exist between sampling station distance from waste dump and dissolved oxygen (r = 0.88) and with total suspended solids (r= - 0.73). The study indicates that the river water quality was much lower in higher density, more urbanized areas of Enugu urban where waste generation and management is a growing problem. The study identifies the need for the development of a sustainable municipal waste management strategy that will encourage source reduction, reuse and recycling of solid wastes. The strategy will lead to the enhancement of the ecological integrity of Asata River and its tributaries

Lipase Production by Some Aquatic Phycomycetes in Maiduguri a Semi-Arid Area of Nigeria

Studies on the abilities of three species of aquatic phycomycetes isolated from the semi arid zone of Nigeria in Maiduguri, Borno State to produce lipase was carried out. The isolates included Allomyces anomalus, Allomyces arbuscular and Brevilegnia diclina. These three test aquatic phycomycetes were isolated using baiting technique with hemp seeds and pure cultures maintained on malt extract agar for lipase production. Plate assay and culture broth assay methods using mineral salts medium with tween 80 in conjunction with Olive oil and Mustard seed oil as lipase inducers were used in assessing the abilities of the isolates in producing lipase. The three isolates of aquatic phycomycetes showed via the plate assay method abilities to produce lipase with evidence of halo formation around colonies without stains and separately with intensification of halo formation with methyl red and sudan III indicators. Allomyces anomalus recorded the highest growth and halo diameter followed by Allomyces arbuscular and least by Brevilegnia diclina. Lipase level was not detectable using the culture broth method. Lipase production by aquatic phycomycetes have not been encountered from available literature, hence this preliminary result needs to be optimised fully to exploit new opportunities of lipase production from these group of aquatic fungi

Chemotaxonomic Significance and Environmental Implications of the Phytochemical Constituents of four Mussaenda L. (Rubiaceae) taxa in Nigeria

This work investigated the phytoconstituents of some Mussaenda taxa (Rubiaceae) collected from Nsukka (Derived Savanna) and Uyo (Tropical Rainforest) ecological zones of Nigeria to establish their contribution as possible taxonomic and environmental monitoring markers. Fresh leaf samples used in this study were collected from plants of the same age, air-dried, and made into powder for further use. Histochemical and phytochemical tests were carried out by following the standard procedures. Results of the comparative phytochemical screening revealed the presence of flavonoids, alkaloids, glycosides, phenols, hydrogen cyanide, reducing sugars, soluble carbohydrates, saponins, steroids, terpenoids, and tannins in varying proportions. Results of the phytochemical constitute analysis revealed the presence of the cystoliths from the M. elegans (MEL) and M. erythrophylla (MER) which were absent in Mussaenda “ Doña Aurora” (MDA) and Mussaenda “Doña Luz”(MDL). Further, the presence of the Raphides was unique to MEL while Gum and mucilage were reported only in MDA. Quantitatively, MEL had the highest value of terpenoids (650.88 mg/100g) while MDA had the highest values of phenols (899.27 mg/100g), alkaloids (311.01 mg/100g), reducing sugars (967.35 mg/100g), steroids (2.89 mg/100g), soluble carbohydrates (27.68 mg/100g) and tannins (393.16 mg/100g), and MDL was richest in glucosides (339.64 mg/100g), flavonoids (69.34 mg/100g) and hydrogen cyanides (1.34 mg/100g). The cluster analysis based on obtained phytochemical data revealed three (3) distinct clusters with MEL in cluster 1; MDA and MDL in cluster 2 while cluster 3 had MER.  The evolutionary closeness of the two infraspecific and exotic species (MDA and MDL) were confirmed and their taxonomic relationship with the indigenous infrageneric taxa (MEL and MER) was established. The results also highlight the opportunity of employing plant metabolomics in ecological studies and environmental monitoring.&nbsp

The Abilities of Four Species of Nigerian Aquatic Phycomycetes to Utilize Petroleum and Petroleum Products as Sole Carbon Sources

Studies were carried out on the abilities of four aquatic phycomycetes species isolated from crude oil polluted marine , brackish and fresh water environments in Nigeria to utilize refined Petroleum and Petroleum products as sole sources of carbon. The said species of fungi included Brevilegnia indica, Protoachyla paradoxa, Saprolegnia bhargavi and Thraustotheca clavata. They were grown on fungal culture media which contained mineral salts solution, refined petroleum, kerosene and diesel as sole sources of carbon and agar as a solidifying agent. Two concentrations of each of the resulting oil agar media were used vis 1% and 2%. The resultant medium was then used to culture each of the test fungi in triplicates. The resultant culture plates were then incubated at 25 OC and left for daily observation. The test fungi that grew on each medium were observed for their abilities to emulsify the refined petroleum or its products (diesel and kerosene). Control experiments were also set up using Malt Extract Agar medium. Brevilegnia indica grew on 1% petroleum and diesel growth media but did not grow on kerosene medium. Protoachyla paradoxa grew minimally on diesel medium at 1% and 2% compositions. Saprolegnia bhargavi did not grow on the petroleum agar medium or petroleum products media. Thraustotheca clavata grew minimally on the kerosene medium at both 1% and 2% compositions. The four test fungi emulsified the diesel agar medium at both 1% and 2% compositions. Brevilegnia indica emulsified only petrol at 1% while Non of the isolates emulsified the kerosene medium at both 1% and 2% compositions. Oil globules were also observed in the vegetative hyphae of the test fungi which grew on the experimental culture media. This means that such fungi either degraded or accumulated the petrol or petroleum products in their systems

Productive performance of broiler birds fed Tetrapleura tetraptera fruit meal containing diets

Abstract. A forty-two day feeding trial was conducted to evaluate the effect of diets containing Tetrapleura tetraptera fruit meal on the productive performance of broilers on feed intake, body weight, carcass and organ characteristics. Tetrapleura tetraptera fruit was processed and incorporated in the diets at 0%, 1.0%, 1.5% and 2.0% dietary levels, represented as T1, T2, T3 and T4, respectively, for both starter (7-28 days of age) and finisher phase (28-49 days of age). One hundred and twenty unsexed abor acre broiler birds were brooded for seven days and thereafter 30 birds were randomly allotted to four treatments in a completely randomized design (CRD) and each treatment was replicated three times with 10 birds per replicate. The data collected showed significant (p&lt;0.05) differences for feed intake, body weight changes and feed conversion ratio for both starter and finisher broilers. Live weight, dressed weight and dressing percentage were significantly better for T1 across the treatments (p&lt;0.05). Wing, drumstick breast muscle and thigh cuts were significantly improved at the treatment groups (p&lt;0.05). The gizzard, heart, and spleen were significantly (p&lt;0.05) higher at T1. Liver also differed significantly (p&lt;0.05) with T4 having the highest weight over other treatments. It could therefore be concluded that T2 produced the best body weight and should be recommended for enhanced broiler production.</jats:p

Lipase Production by Some Aquatic Phycomycetes in Maiduguri a Semi-Arid Area of Nigeria

Studies on the abilities of three species of aquatic phycomycetes isolated from the semi arid zone of Nigeria in Maiduguri, Borno State to produce lipase was carried out. The isolates included Allomyces anomalus, Allomyces arbuscular and Brevilegnia diclina. These three test aquatic phycomycetes were isolated using baiting technique with hemp seeds and pure cultures maintained on malt extract agar for lipase production. Plate assay and culture broth assay methods using mineral salts medium with tween 80 in conjunction with Olive oil and Mustard seed oil as lipase inducers were used in assessing the abilities of the isolates in producing lipase. The three isolates of aquatic phycomycetes showed via the plate assay method abilities to produce lipase with evidence of halo formation around colonies without stains and separately with intensification of halo formation with methyl red and sudan III indicators. Allomyces anomalus recorded the highest growth and halo diameter followed by Allomyces arbuscular and least by Brevilegnia diclina. Lipase level was not detectable using the culture broth method. Lipase production by aquatic phycomycetes have not been encountered from available literature, hence this preliminary result needs to be optimised fully to exploit new opportunities of lipase production from these group of aquatic fungi.</jats:p

Microbial quality of two man-made lakes in Lokpa Abia State, Nigeria

The microbial quality of two man-made lakes that serve as sources of water to a rural community was investigated