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Showing papers by "Rivers State University of Science and Technology published in 1999"


Journal ArticleDOI
TL;DR: The Delta red colobus occupies an exceptionally low lying habitat of marsh forest, and its range lies within an area that had been independently identified as a centre of primate endemism, so it may have survived climatic vicissitudes of the Pleistocene in a Delta refuge.
Abstract: A distinctive and geographically isolated population of red colobus monkey Procolobus badius has been discovered in the Niger Delta within what was previously believed to be a discontinuity in the distribution of the species some 1200 km across. This Delta red colobus represents a new subspecies, P. b. epieni, most closely resembling the taxon on Bioko (P. b. pennantii) in such features as black hands and feet, and lack of orange-brown tones on head and neck, but differing in having whitish arms and hair whorls above the ears. It is less similar to subspecies on the mainland to the west or east (P. b. waldroni in Ghana and P. b. preussi in Cameroon, respectively), implying a complex zoogeographical history for the species. The Delta red colobus occupies an exceptionally low lying habitat of marsh forest, and its range lies within an area that had been independently identified as a centre of primate endemism, so it may have survived climatic vicissitudes of the Pleistocene in a Delta refuge. As it is confined to an area of about 1500 km2, it is now vulnerable to increasing human pressures.

61 citations


Journal ArticleDOI
TL;DR: The general diet composition of the two species was similar (78.2% of overlap), and even the habitats where these two species were found were similar, which suggest that O. tetraspis and V. niloticus could be potential competitors in the freshwater ecosystems of the Nigerian rainforest.
Abstract: Aspects of coexistence between the dwarf crocodile Osteolaemus tetraspis and the Nile monitor lizard Varanus niloticus were studied in swamp rain forests of south-eastern Nigeria, central Africa. Crocodiles were significantly smaller than monitor lizards. There was no significant sexual size dimorphism in the examined sample of Varanus, whereas the female size exceeded the male size in Osteolaemus. The food niche breadth was narrower in young than in adults of both species, and V. niloticus showed a narrower niche breadth than O. tetraspis. Crabs constituted the main prey type category for both species, whereas vertebrates were more rarely preyed upon. The diet composition of males and females was similar in V. niloticus, but it was different in O. tetraspis. The general diet composition of the two species was similar (78.2% of overlap), and even the habitats where these two species were found were similar. These interspecific similarities suggest that O. tetraspis and V. niloticus could be potential competitors in the freshwater ecosystems of the Nigerian rainforest. However, it is suggested that the main prey type for these species (crabs) is not limited in the environment, which may minimize interspecific competition. Interference competition can also occur between these species, as suggested by one case of direct predation of the one species (V. niloticus) towards the other species (O. tetraspis). A case of cannibalism was observed in V. niloticus. This could indicate that intraspecific competition can be important for regulating the dynamics of monitor populations in the rainforests of south-eastern Nigeria.

54 citations


Journal ArticleDOI
TL;DR: In this article, the impoundment of 49 dams in the Niger catchment area with a combined reservoir capacity of 36 million m3 has a direct impact on the Niger Delta, resulting from the reduction in flow and sediment delivered to the coast.
Abstract: The Niger Delta has a fragile coastline in which the river hydraulic forces are in dynamic equilibrium with coastal processes. The impoundment of 49 dams in the Niger catchment area with a combined reservoir capacity of 36 million m3 has a direct impact on the Niger Delta, resulting from the reduction in flow and sediment delivered to the coast. The delta has experienced shifts in the ecological equilibrium manifested as adjustments to the coastline geometry, lower flood water levels and upstream migration of tidal influences. Although the effects of upstream dams are cumulative, the large capacity dams have the most immediate impact. The construction of the dams results in a sudden drop in water level which is followed by a gradual recovery. Data from the Niger Delta suggests that although some rivers recover part of their flow, levels are still below those which existed prior to the construction of the Kainji Dam.

48 citations


Journal ArticleDOI
TL;DR: In this paper, the taxonomic composition and abundance of two communities of snakes were studied in two different areas of southern Nigeria, one derived savanna area and one derived rainforest area.
Abstract: The taxonomic composition and the abundance of two communities of snakes were studied in two different areas of southern Nigeria. One community was studied in a derived savanna area (environs of Ejule, 06°54′N, 07°23′E), and one community was studied in a moist rainforest area (environs of Eket, 04°50′N, 07°59′E). Both the specific diversity and the mean frequency of observation of snakes were significantly higher in the forest area than in the savanna area, and the dominance index was higher in the savanna than in the forest site. However, most of the species were found in only one of the two areas, depending on their habitat requirements (e.g. Gastropyxis smaragdina, Dispholidus typus, Thelotornis kirtlandii, Dendroaspis jamesoni, Bitis nasicornis, Causus maculatus, etc). The forest community housed a significant number of arboreal and semiaquatic taxa, but in both sites most of the species were terrestrial. The commonest species in the forest area was an oviparous, semiaquatic, batracophagous natricine snake (Afronatrix anoscopus), whereas the commonest species in the savanna area was an oviparous terrestrial lacertophagous psammophine snake (Psammophis phillipsi). Some conservation implications of our biodiversity analyses are presented. It is suggested that the moist rainforest represents a critically endangered habitat, and should deserve special attention by the international scientific community. Oil industry activity is especially dangerous for snake communities, especially in the southernmost regions of Nigeria.

46 citations


Journal ArticleDOI
TL;DR: Alchornea decomposed slowly and therefore could be used to improve Chromolaena mulch, thus contributing to the build up of soil organic N and providing both short- and long-term nutrient release.
Abstract: Four shrub/tree species, Alchornea cordifolia, Pennisetum purpureum, Chromolaena odorata, and Calliandra calothyrsus were evaluated for their potential contribution to soil fertility restoration after two years fallow. Standing biomass, root distribution, nutrient content in the biomass, decomposition and nutrient release patterns, and association with mycorrhizae were the evaluation parameters. Alchornea and Pennisetum produced thehighest above-ground biomass, 66 t and 54 t/ha respectively. Pennisetum had more than 19 t/ha of root, 92% of which was in the 20 cm top soil. Alchornea had 74% of it roots in this soil layer, mostly as coarse roots while Calliandra had a deeper root system. Alchornea fallow accumulated more N and Ca, and Pennisetum fallow, more K than others, and mycorrhizae were mostly associated with Alchornea roots. The ranking of the different species for the decomposition rate was: Chromolaena > Pennisetum > Calliandra = Alchornea. Also release of nutrients during decomposition followed the order K > N > Ca. Alchornea and Pennisetum could be recommended as green manure species especially when high quantities of material are needed for weed or erosion control. Calliandra and Chromolaena, because of the flush of nutrient during early mass, loss can be used as mulch when the crop demand of nutrient is high. Alchornea decomposed slowly and therefore could be used to improve Chromolaena mulch, thus contributing to the build up of soil organic N and providing both short- and long-term nutrient release.

34 citations


Journal ArticleDOI
TL;DR: Protein concentrates had comparatively better fat absorption properties than the flour samples, hence protein concentrates may prove to have useful applications in ground meat formulations.
Abstract: In vitro protein digestibility, chemical composition and selected functional properties of flours and protein concentrates prepared from raw, fermented and germinated fluted pumpkin (Telfairia occidentalis Hook) seeds were studied. Protein concentrates prepared by an alkaline extraction process had increased crude protein contents (61.5-70.8%) compared to flour samples (46.4-52.7%). The yields of protein concentrates ranged from 24.5% to 29.4% while values for protein recoveries varied between 64.8% and 65.2%. Protein concentrates also had increased foam volume and decreased foam stability (100% decrease over a 2 h period), compared to flour samples. Fermentation and germination were observed to significantly (p < 0.05) lower polyphenol and phytic acid contents, but increased protein digestibility of fluted pumpkin seed flours and concentrates. Both raw flour and concentrate were significantly (p < 0.05) higher in water absorption capacity than germinated or fermented flours and concentrates. Protein concentrates had comparatively better fat absorption properties than the flour samples. Hence protein concentrates may prove to have useful applications in ground meat formulations.

33 citations


Journal ArticleDOI
TL;DR: Proximate analyses for moisture, protein and fat of the cotyledons showed an increase in all three constituent at each of the three fermentation temperatures, and total available carbohydrate was 55%, 59% and 62% of the original value at 30, 37 and 45 °C, respectively.
Abstract: Bambara groundnut (Vigna subterranea) was fermented to produce a dawadawa-type product using a starter culture of Bacillus licheniformis isolated from naturally fermenting bambara groundnut beans. Fermentation was carried out at 30 and 37 °C for four days and at 45 °C for two days. The pH of the substrate decreased after 24 hours and then rose at 30 and 37 °C but remained constant at 45 °C after the initial drop. Total titratable acidity of the fermenting beans mimicked the pH values. Proximate analyses for moisture, protein and fat of the cotyledons showed an increase in all three constituent at each of the three fermentation temperatures. At the end of fermentation, total available carbohydrate was 55%, 59% and 62% of the original value at 30, 37 and 45 °C, respectively. Fermentation of bambara groundnut at 45 °C for two days is recommended as the ideal fermentation temperature and time.

27 citations


Journal ArticleDOI
TL;DR: Germination significantly increased the crude protein, nitrogen solubility and in vitro protein digestibility but decreased the fat, phytic acid and polyphenol contents of the seeds.
Abstract: The effect of 7 days of germination on levels of nitrogenous and other nutrition related parameters, protein fractions and in vitro protein digestibility of fluted pumpkin (Telfairia occidentalis) seed was studied. The non-protein nitrogen gradually increased and the protein nitrogen content decreased during germination. Albumin and globulin fractions were found to be the major seed proteins of fluted pumpkin seeds, constituting about 58.6% of the total protein of the ungerminated (raw) seeds. The protein fractions, albumin and glutelin, were observed to increase by 61.5% and 57.0%, respectively, while a 54.6% decrease was noted in the prolamine fraction. The globulin fraction increased at the beginning of germination but decreased at the end. Germination significantly (p ≤ 0.05) increased the crude protein, nitrogen solubility and in vitro protein digestibility but decreased the fat, phytic acid and polyphenol contents of the seeds.

26 citations


Journal ArticleDOI
TL;DR: Sensory evaluation showed that bambara groundnut tempes rated similar in taste and texture and higher in color and flavor than soybean tempe, and would be an acceptable food product in the diet as a good protein supplement.
Abstract: Bambara groundnut, an indigenous African legume, was subjected to fermentation by three strains of Rhizopus. One strain B. arrhizus could not ferment the substrate. Mycelial penetration and binding was good when strains NRRL 2710 ( R. oligosporus) and NRRL 1477 ( R. stolonifer) were used. Fermentation by both strains resulted in increases of pH, moisture, protein and fat while total carbohydrate decreased by 50%. Sensory evaluation showed that bambara groundnut tempes rated similar (p>0.5) in taste and texture and higher (p<0.05) in color and flavor than soybean tempe. Bambara groundnut would be an acceptable food product in the diet as a good protein supplement.

16 citations


Journal ArticleDOI
TL;DR: Chicken droppings offered the lowest Relative Protection (RP) values to most pepper varieties in 1995 and 1996 and NPK chemical fertilizer offered the highest percentage RP values in1995 and wood ash offering the highest RP in 1996 to most Pepper varieties.
Abstract: Experiments were conducted in 1995 and 1996 to determine the effects of different sources of nutrients on the infestation of fruits of five pepper varieties by Atherigona orientalis (Schiner). Different sources of nutrients — chicken droppings, plant residues (compost manure), wood ash and NPK (chemical fertilizer) — were used in the planting of each of the five pepper varieties [Nsukka yellow, Atarugu, and Sweet pepper, all of Capsicum annum; Bird’s eye chilli and Local medium red (Ogoni pepper) both of C. frutescens]. In 1995 plantings, pepper plots of Nsukka yellow and Atarugu varieties that received chicken droppings as source of nutrients suffered the highest percentage fruit damage of 90.7 % and 80.8 %, respectively. Pepper plots of Nsukka yellow, Atarugu, Sweet pepper and Local medium red grown in 1996 and treated with chicken droppings suffered the highest percentage fruit damage of 93.7 %, 56.6 % and 52.2 %, respectively. Plots of the Bird’s eye chilli variety received minimal or no fruit damage in all. Pepper fruits in the control plots also did not undergo A. orientalis attack. Chicken droppings offered the lowest Relative Protection (RP) values to most pepper varieties in 1995 and 1996. NPK chemical fertilizer offered the highest percentage RP values in 1995 and wood ash offered the highest RP in 1996 to most pepper varieties. Also, wood ash in both 1995 and 1996 offered a relatively high percentage RP to most pepper varieties. Compost manure offered a moderate percentage RP in both years.

11 citations


Journal ArticleDOI
TL;DR: The biodegradation of Bonny light crude petroleum by bacteria in batch culture was enhanced by the addition to culture media, of 0.2 mg of urea and soya bean lecithin per 100 ml of crude oil, sediment and water mixture as mentioned in this paper.
Abstract: The biodegradation of Bonny light crude petroleum by bacteria in batch culture was enhanced by the addition to culture media, of 0.2 mg of urea and soya bean lecithin per 100 ml of crude oil, sediment and water mixture. Biodegradation was found to be purely an aerobic process. There was a direct relationship between hydrocarbon content and proportion (%) of total heterotrophic count that was capable of growing on crude petroleum as sole carbon and energy source. Resume On a ameliore la biodegradation de petrole leger brut Bonny par des bacteries en culture par lots en ajoutant au milieu de culture 0,2 mg d’uree et de lecithine de soja par 100 ml de melange de petrole brut, de sediment et d’eau. On a decouvert que la biodegradation etait un processus purement aerobique. Il y avait une relation directe entre le contenu en hydrocarbure et la proportion (en %) du compte total d’organismes heterotrophiques qui etaient capables de se developper avec du petrole brut pour unique source de carbone et d’energie.


Journal ArticleDOI
TL;DR: Soil pH was positively and significantly correlated with the roots initial C‐to‐N ratio and negatively correlated with their initial N content and at 24 weeks of incubation, the pH of all treatments reverted to initial value.
Abstract: A laboratory experiment was carried out to assess nitrogen (N) mineralization of roots of four woody agroforestry species (Dactyladenia barteri, Senna siamea, Gliricidiasepium, and Leucaena leucocephala) and maize (Zea mays). Addition of Gliricidia and Leucaena roots with high N contents and low carbon (C)‐to‐N ratio (≤14.0) resulted in net N mineralization, while the addition of maize roots with low N and high C‐to‐N ratio (40.3) immobilized N. Addition of Dactyladenia and Senna roots with intermediate N content and C‐to‐N ratio immobilized N to a lesser extent. Nitrogen mineralization was negatively and significantly correlated with C‐to‐N ratio of the added roots. Addition of roots of the five species also differentially affected soil pH during the first 12 weeks of incubation. Soil pH was positively and significantly correlated with the roots initial C‐to‐N ratio and negatively correlated with their initial N content. At 24 weeks of incubation, the pH of all treatments reverted to initial value.

Journal ArticleDOI
TL;DR: The occurrence of Staphylococcus aureus, Bacillus sp.
Abstract: A survey of microbial flora of partially processed periwinkles (Tympanotonus fuscatus) sold in six markets in Port Harcourt was undertaken for twelve weeks. Results show that all samples of periwinkles were contaminated with Staphylococcus aureus, Bacillus sp., Escherichia coil, Staphepidermidis sp., Micrococcus sp., Pseudomonas sp., and Klebsiella sp. Staphylococcus aureus was the most predominant 24.9% while Klebsilella sp. was the least 5.80%. The occurrence of Staphylococcus aureus, Bacillus sp., and Escherichia coil is indicative of a high pathogenicity and health hazard in consuming periwinkles. The need to critically re-examine our public health standards in the markets is advocated. Journal of Aquatic Sciences Volume 14, April 1999, pp. 51-54 KEY WORDS: Microbial flora, periwinkles flesh, Port Harcourt, Markets.