Showing papers by "Rivers State University of Science and Technology published in 2002"

Domestication of Irvingia gabonensis: 2. The selection of multiple traits for potential cultivars from Cameroon and Nigeria

Abstract: Ten fruit and kernel traits were assessed in 24 fruits of each of 152Irvingia gabonensis trees in three distinct populations in west and central Africa [2 populations of non-planted trees in Cameroon: Nko'ovos II (21 trees) and Elig-Nkouma (31 trees) and 1 population of planted trees in Nigeria: Ugwuaji (100 trees)]. Strong relationships were found between fruit weight and other fruit traits (e.g. flesh weight[r2 = 0.99: P < 0.001],fruit length [r2 = 0.74–0.83:P < 0.001], fruit width[r2 = 0.77–0.88: P< 0.001]). In contrast, relationships between kernel weight and other kernel/nut traits (e.g. shell weight and nut weight) were found to be weak[r2 = 0.009–0.37, P =0.058–0.001], with the exception of nut weight at Nko'ovos II(r2 = 0.65, P < 0.001).Relations hips between fruit and kernel traits (fruit massv. kernel mass, fruit mass v. shell mass, flesh mass v. kernel mass, nut massv. fruit mass and flesh depth v.kernel mass) were found to be very weak. This indicates that domestication through the selection and vegetative propagation of multiple-trait superior phenotypes is unlikely to be able to combine good fruit characteristics and good kernel characteristics within cultivars. Consequently, domestication activities should independently focus on ideotypes representing: 'fresh fruit' traits, and 'kernel' traits, that combine high values of the different fruit and kernel characteristics respectively. Evidence from this study indicates that selection of the three trees closest to the fruit ideotype per village as the mother plants for vegetative propagation and cultivar development, should give village level gains of 1.3 – 2-fold in fruit mass, and up to 1.5-fold in taste. Similarly for the kernel ideotype, selection of the three trees with the best fit would give potential gains in kernel mass of 1.4 – 1.6-fold.

Domestication of dacryodes edulis in west and central africa: characterisation of genetic variation

Abstract: New initiatives in agroforestry are seeking to integrate trees with marketable products into farming systems. This is being done in order to provide marketable timber and non-timber forest products from farms that will enhance rural livelihoods by generating cash for subsistence farmers. Dacryodes edulis (Safou) is one of the candidate tree species in West and Central Africa for domestication, which has commercial potential in local, regional or even international markets. This paper describes: (i) the characterisation of tree-to-tree variation in fruit traits and the opportunities for selecting D. edulis cultivars based on the intraspecific variation found in local populations in Cameroon and Nigeria, (ii) the identification of multi-trait ideotypes for potential cultivar development, (iii) the organoleptic attributes which are important traits for selection, and (iv) an assessment of the relationships between fruit mass and market prices in fruit samples from three markets, at the peak of season, in Cameroon.

Nutrient cycling practices and changes in soil properties in the crop-livestock farming systems of western Niger Republic of West Africa

Abstract: Pearl millet [Pennisetum glaucum R. (Br.) L.] is grown in West Africa on sandy, acid soils deficient in plant nutrients. In the mixed farming systems of western Niger, livestock graze millet stover by day and deposit dung and urine directly on cropland during overnight kraaling. Kraaling of livestock is perhaps the most important pathway to recycle nutrients and sustain soil fertility. Three tillage practices (immediate tillage, late tillage and no till) four amendment types (dung-plus-urine, dung alone, millet stover and millet stover ashes), and three fertilizer N rates (0, 15 and 30 kg N ha−1) were factorially combined and arranged in a split plot design. Average millet grain yield in immediate till plots was 30% higher than in no-till plots and was 13% greater in plots amended with dung-plus-urine than in plots that received manure alone. The highest pH (5.8) and lowest bulk density 1.46 g/cm3 of surface soil were measured in plots amended with dung-plus-urine. Under the less nomadic livestock management system, where animals are mostly stall-fed, technology is needed to capture and transfer nutrients in animal urine to farmers' fields for cropping.

Is thermoregulation really unimportant for tropical reptiles? Comparative study of four sympatric snake species from Africa

Abstract: Most of the studies concerning the thermal and reproductive relationships of snakes have been conducted in temperate regions, whereas very few data are available for African tropical species. In the present study, aspects of the comparative thermal and reproductive ecology of four sympatric freshwater snakes from tropical Africa (the colubrids Natriciteres fuliginoides, N. variegata, Afronatrix anoscopus, and Grayia smythii) are studied with emphasis on exploring whether their thermal ecology relations with reproduction biology may indicate a substantial influence of thermoregulation on their life-history traits (as shown in several studies from temperate-zone reptiles), or whether thermoregulatory biology is less important in tropical reptiles (as suggested in some recent experimental studies). The present study showed that, with minor species-specific differences, thermoregulation certainly has some relevance for the activity and life-history attributes of the studied species, as (i) the females tended to show body temperatures inversely related to their size (snout‐vent length), and (ii) gravid specimens tended to maintain higher body temperatures than non-gravid specimens. However, other sets of our data (e.g., the high and constant Tb exhibited during night-time) strongly indicate that these four species of tropical water snakes can maintain high and stable Tb with little overt thermoregulatory behaviour. As is the rule in most of the other snake species studied to date, the maternal size of the females strongly influenced the number of eggs produced, and testifies that reproductive biology models linking reproductive performance to thermal ecology, highlighted in other snakes from temperate and cool regions, may well apply at least to some extent also to these Afrotropical species. © 2002 Editions scientifiques et medicales Elsevier SAS. All rights reserved.

An investigation into the composition, complexity and functioning of snake communities in the mangroves of south‐eastern Nigeria

Abstract: The structure of the snake community was studied between 1996 and 2000 on a transect in the mangrove ecological zone of southern Nigeria, West Africa. In three major habitats, both taxonomical diversity and frequency of observations in relation to sampling effort were investigated. In general terms, the complexity of the snake community appeared less than in other habitats of the same geographic region (i.e. swamp forest and forest–plantation mosaics). In fact, only eighteen species were recorded, whereas 43 species are known to inhabit neighbouring habitats. A Principal Component Analysis allowed arrangement of the various species into two main groups in relation to the habitats of capture: (1) a group of species of rainforest biota (i.e. Toxicodryas blandingii, Thelotornis kirtlandii, Thrasops flavigularis, Rhamnophis aethiopissa, Gastropyxis smaragdina, Grayia smythii, Pseudohaje goldii, Python sebae), and (2) a group of species that, at least in Niger Delta, are typically linked to altered habitats, including derived savannas, plantations and suburbia (i.e. Psammophis cf. phillipsi, Philothamnus cf. nitidus, Hapsidophrys lineatus, Crotaphopeltis hotamboeia, Boaedon lineatus, Naja nigricollis, Python regius). The community structure in terms of food habits and body sizes appeared similar to those of other snake assemblages from different habitats of southern Nigeria. The conservation implications of our results are also discussed. Resume On a etudie entre 1996 et 2000 la structure de la communaute des serpents dans un transect de la zone ecologique de mangroves du sud du Nigeria, en Afrique de l'Ouest. On a etudie, dans trois habitats importants, la diversite taxonomique et la frequence des observations par rapport a l'importance des echantillonnages. En termes generaux, la communaute des serpents y semblait moins complexe que dans d'autres habitats de la meme region geographique (c.-a-d. la foret marecageuse et une mosaique de plantations forestieres). En fait, on n'a rapporte que 18 especes, alors qu'on sait que 43 especes vivent dans les habitats voisins. Une Analyse du Composant Principal a permis de ranger les differentes especes en deux groupes principaux, lies aux habitats ou se sont faites les captures : (1) un groupe avec les especes des biotes de foret pluviale (Toxicodryas blandingii, Thelotornis kirtlandii, Thrasops flavigularis, Rhamnophis aethiopissa, Gastropyxis smaragdina, Grayia smythii, Pseudohaje goldii, Python sebae) et (2) un groupe d'especes qui, au moins dans le delta du Niger, sont typiquement liees a des habitats degrades, y compris des savanes derivees, des plantations et des faubourgs urbains (Psammophis phillipsi, Philothamnus cf. nitidus, Hapsidophrys lineatus, Crotaphopeltis hotamboeia, Boaedon lineatus, Naja nigricollis, Python regius). La structure de la communaute, en ce qui concerne les habitudes alimentaires et la taille corporelle, etait semblable a celle des autres groupes de serpents dans differents habitats du sud du Nigeria. On discute de l'implication de nos resultats pour la conservation.

Effluent quality and wastes from petroleum drilling operations in the Niger Delta, Nigeria

Abstract: The research assessed the development of petroleum drilling activities and its associated waste discharges in the Niger Delta environment of Nigeria. Field visits were made to 18 wells in which petroleum drilling operation was in progress. Of this number, wastes samples were randomly collected from ten wells for data collation and laboratory analysis. Results show that petroleum drilling waste types in Nigeria include cuttings, mud/chemical, oil spills, cement slurry/dust, condemned pipes, filters, and machinery parts and even noise. Pretreatment of waste in hardly undertaken by the oil prospective companies before discharge into the surrounding environment. Total dissolved solid and oil/grease values as high as 3700mg l–1 and 1100 parts per million, respectively, were tested as effluent discharges around some of the wells studied. It was recommended that the Nigerian Government constitute a powerful environment monitoring body whose responsibility will be to ensure that the various multi‐national oil companies comply with petroleum laws and statutes of the country.

Yield and disease resistance of plantain (Musa spp., AAB group) somaclones in Nigeria

Abstract: This study examined the potential of somaclonal variation for the improvement of plantain. Approximately 500 somaclones each of ‘Agbagba’ (False Horn plantain) and ‘Bise Egome’ (French plantain) were field evaluated for their agronomic performance and response to the black Sigatoka disease. The micropropagated populations were independently generated from a number of suckers from each accession. Significant differences between micropropagated accessions and crop cycles were observed. Differences between plants derived from suckers of the same accession were also expressed, indicating the chimerical nature of variation in the traits studied. None of the plants of the micropropagated populations from ‘Bise Egome’ exhibited significantly better disease tolerance and agronomic performance than the source accession. However,one somaclonal variant of ‘Agbagba’ (‘AO 2B2-2’) expressed lower susceptibility to the black Sigatoka disease. Compared to ‘Agbagba’, ‘AO 2B2-2’ had a higher bunch weight, more fruits per bunch with higher average weight, greater average length, and greater average girth. These data clearly show that, in contrast to previous reports, it is possible to recover superior somaclonal mutants in Musa.

Chemical composition and nutritional attributes of selected newly developed lines of soybean (Glycine max (L) Merr)

Abstract: The chemical composition and nutritional properties of raw, autoclaved and boiled samples of three promising advanced breeding lines of soybean (TGx 923 − 2EN, TGx 1019 − 2EN and TGx 1497 − 1D), part of a larger collection evaluated in agronomic field trials in Nigeria, were investigated. Protein quality was evaluated using weanling albino rats fed diets which were formulated to supply 10% protein using soybean samples, with casein as a control. Raw seeds contained 35.6–42.4% crude protein, 8.9–9.8 mg iron per 100 g, 8.62–18.21 mg trypsin inhibitor g−1 and 2.25–6.15 mg phytic acid g−1 seed flour. TGx 923 − 2EN possessed higher crude protein contents and lower amounts of trypsin inhibitor, polyphenol and phytic acid compared with TGx 1019 − 2EN or TGx 1497 − 1D. Boiling proved more effective than autoclaving for reducing the levels of antinutrients and improving the protein quality of the beans, as shown by the higher values for weight gain, protein efficiency ratio (PER), net protein ratio (NPR) and true digestibility (TD) of boiled samples. There were no significant (p > 0.05) differences between the values obtained for PER, NPR and TD of diets containing boiled samples of TGx 923 − 2EN and casein, indicating the nutritional superiority of this soybean line compared with TGx 1019 − 2EN and TGx 1497 − 1D. © 2002 Society of Chemical Industry

Is sexual size dimorphism in relative head size correlated with intersexual dietary divergence in West African forest cobras, Naja melanoleuca?

Abstract: Sex-biased differences in dietary habits of snakes are often linked to pronounced sexual size dimorphism in absolute body size or in relative head size We studied the food habits of free-ranging forest cobras (Naja melanoleuca) in southern Nigeria to find whether any intersexual dietary divergence is present in this species, and measured both museum vouchers and freeranging specimens to find whether any intersexual divergence in relative head size is present We demonstrated that: (1) head sizes increases more rapidly with SVL in females than in males, with a result that, at the same body length, the females tended to have significantly larger heads; (2) males and females were nearly identical in dietary habits, both if we consider prey size or prey type; (3) both sexes tended to prey upon relatively little sized preys It is concluded that traditional evolutionary scenarios for explaining sexual dimorphism and food niche divergence are hardly valid in this case, and we need to look for entirely different hypotheses (eg linked to the sexual preference of males for females with larger heads)

Frequency of tail autotomy in the African Olive Grass Snake, Psammophis ‘phillipsii’ from three habitats in southern Nigeria

Abstract: Extracted from text ... Short communication Frequency of tail autotomy in the African Olive Grass Snake, Psammophis 'phillipsii' from three habitats in southern Nigeria GODFREY C. AKANI1, LUCA LUISELLI2, 3, SUNDAY M. WARIBOKO1, LINDA UDE2 AND FRANCESCO M. ANGELICI2 1Department of Biological Sciences, Rivers State University of Science and Technology, P.M.B. 5080, Port Harcourt (Rivers State), Nigeria 2F.I.Z.V. (Ecology) and Centre of Environmental Studies "Demetra", Via Olona 7, I-00198 Rome, Italy 3lucamlu@tin.it Key words.- Psammophis phillipsii, rainforest, habitat variation, predation, tail autotomy, Nigeria. 143 African Journal of Herpetology, 2002 51(2): 143-146. Tail autotomy is an unambiguous antipredatory adaptation that occurs in a wide variety of ..

A cytogenetic study of bilateral sexual polyploidization in cassava (Manihot esculenta Crantz)

Abstract: Microsporogenesis and megasporogenesis were cytogenetically and histologically analysed in three cassava clones:‘Rayong 1′,‘Rayong 60′,‘M. mga’ and two hybrid lines,‘OMR 3641-1’ and ‘OMR 3641-1’ to elucidate the evolution of sexual polyploids in cassava. At telophase II, formation of 17-21 micronuclei per pollen cell plate was observed in 16 out of 351 cell plates in ‘M. mga’. Micronuclei were observed at low (0.3-2.3%) frequencies, at the sporad stage in all clones. Monads, dyads, triads and tetrads, which are established sources of high ploidy levels were observed at low (2.6%) and high (22.2%) frequencies. Megasporogenesis in ‘Rayong 1’ and ‘Rayong 60’ showed a lack of second meiotic divisions after a successful first division that resulted in partly unreduced embryo sacs with 2n eggs, suggesting another unrecognized and, as yet, unreported source of sexual polyploid formation in cassava. Meiotic abnormalities during microsporogenesis and megasporogenesis are implicated as being responsible for the formation of mixoploids (triploids and tetraploids) in cassava breeding programmes. A cytogenetic mechanism resulting in bilateral sexual polyploids through different gametic fertilization pathways in cassava is suggested and its role in breeding is briefly discussed.

Domestic waste levels and an assessment of their current management strategies in Yenogoa Metropolis

Abstract: The quantities and types of domestic solid wastes were determined for the purposes of planning and effective management of wastes in the Yenagoa metropolis. The current status of waste management in the metropolis was also assessed to identify the problems and prospects for effective waste management. The study shows that with a per capita daily waste production of 0. 189±0.039 kg, an average of about 28, 350 kg of waste are produced daily in Yenagoa metropolis. About 83% of the wastes produced were food wastes made up mainly of yam and plantain peelings. As regards current status of waste management, the study observed that, there was no equipment available for the management of domestic solid waste and no final dumping site for sanitary disposal of wastes was available. The major problems militating against the effective management of wastes were the lack of awareness on the part of the citizenry of the importance of proper waste disposal; the non-availability of collection points and the lack of political will of the relevant ity to meet the demands of proper waste management. Keywords: Domestic waste levels, management, Yenagoa [Global Jnl Environ Sci Vol.1(1) 2002: 15-20]

Microorganisms associated with palm weevil larvae (rhynchophorus phoenicis)

Abstract: Fresh as well as fried Palm weevil (Rhynehophorus Phoenicis) lervae collected from port Harcourt metropolis in River State, Nigeria were analysed for associated microrganisms. These were found to belong to four bacterial genera-Bacillus, Staphyioeoceus, Serratia and Enterobacter. However, Spp of Bacillus and Staphyiocoecus which were predominant and most actwely involved organisms probably due to unhygenic handling, could be toxic and health hazord.

Self-Serving Attributions in Teachers' Explanations of Students' Performance in a National Oral Essay Competition

Abstract: The purpose of the study was to determine the influence of self-serving and ingroup-outgroup biases on teachers' attributions and evaluation of students' performances. The participants were 51 senior secondary school students whose performances in an oral essay competition were evaluated by a panel of 5 judges. After the competition, the teachers were asked to make attributions of their students' performances in the competition. The findings revealed that the teachers of the successful students attributed the success to internal factors while the teachers of the unsuccessful students attributed the students' failures to external factors. It was concluded that self-serving and ingroup-outgroup biases influenced the teachers' attributions and judgment of their students' performances.

Evaluating the Characteristics of the Meander Belt Soils of the Niger Delta, Southeastern Nigeria

Abstract: The morphological, physical, chemical and pedological properties of eight pedons representative of the four physiographic units in the Meander Belt of the Niger Delta were studied. The soils were classified and the constraints to their agricultural and engineering uses evaluated. The soils were generally poorly drained, having an Aquic moisture regime, mottles and Fe and Mn concretions. They belong to the Entisol and Inceptisol USDA soil taxonomy orders. Soil textures were generally clayey, except for the pedons of the levee crest with sandy loam textures. Bulk density, particle density and total porosity were generally low. Total nitrogen and available phosphorus were also low. The cation exchange capacity (CEC) and base saturation were high. Organic matter was low to moderate. Total elements of the clay were generally high. The soils have poor physical conditions. The high clay content, and the presence of 2:1 lattice clay minerals could account for the deterioration of the major east-west interstate road linking southeast and southwest Nigeria that passes through the area. Optimum use of the soils for agriculture would depend on good land evaluation and efficient soil water management.

Marketing strategies of hospital service organizations in Nigeria: a study of selected privately owned hospitals in Port Harcourt.

Abstract: This study was centered on the identification of the marketing strategies of hospitals and the factors that militate against their effective adoption and implementation. A total of 80 hospitals in Port Harcourt responded to a structured questionnaire administered on them. It was found, among other things, that many hospital organizations apply marketing strategies, and that hospitals that adopt effective marketing strategies perform better than those that do not. Some of the factors militating against the effective adoption and implementation of marketing strategies include lack of planning, lack of top management support, and non-utilization of all the promotional mix elements.

Range-extension of black-fronted duiker (Cephalophus nigrifrons Gray 1871, Artiodactyla Bovidae): first records from Nigeria

Abstract: The black-fronted duiker (Cephalophus nigrifrons) was previously known only from Central Africa. A geographically isolated population has now been found in a small area of the Niger Delta, 500 km from its previously known distribution. It is locally common in the marsh forest zone but has become extinct in some districts. The Nigerian population is indistinguishable from the nominate subspecies C. n. nigrifrons. Its discovery adds to the list of endemic taxa and isolated populations of otherwise widespread species restricted to southern Nigeria. This faunal element may have survived adverse environmental perturbations in a refuge focused on the Niger Delta during the high-latitude glaciations.

Manufacturing of emery cloth (sand paper)from local raw materials

Abstract: This paper identifies surface finishing (grinding) as a major engineering process in production industries and that emery cloth otherwise know as ";sand paper"; is used for this purpose. The grinding process is discussed in details. The materials and their sources requires for the production of the emery cloth are discussed and also the physical properties of the materials are considered. The paper discusses the manufacturing stages of the cloth. Three main stages were identified — sand preparation, backing paper preparation and the emery cloth production. Finally the require quality control processes were considered, a detailed cost analysis was carried out and conclusions were drawn. Keywords: Emery Cloth, materials production, cost [Global Jnl Engineering Res. Vol.1(1) 2002: 31-38]

Financial statistics for public health dispensary decisions in Nigeria: insights on standard presentation typologies.

Abstract: Public health dispensaries in Nigeria in recent times have demonstrated the poise to boost corporate productivity in the new millennium and to drive the nation closer to concretising the lofty goal of health-for-all. This is very pronounced considering the face-lift giving to the physical environment, increase in the recruitment and development of professionals, and upward review of financial subventions. However, there is little or no emphasis on basic statistical appreciation/application which enhances the decision making ability of corporate executives. This study used the responses from 120 senior public health officials in Nigeria and analyzed them with chi-square statistical technique. The results established low statistical aptitude, inadequate statistical training programmes, little/no emphasis on statistical literacy compared to computer literacy, amongst others. Consequently, it was recommended that these lapses be promptly addressed to enhance official executive performance in the establishments. Basic statistical data presentation typologies have been articulated in this study to serve as first-aid instructions to the target group, as they represent the contributions of eminent scholars in this area of intellectualism.