Showing papers by "University of Nigeria, Nsukka published in 1999"

Role of hydrophobic components of soil organic matter in soil aggregate stability

Abstract: Little is known about the effects of the individual components of organic matter (OM) on aggregate stability (AS) We hypothesized that AS of a Typic Haplustalf from which native OM was either removed or retained would be affected by incubation periods and application rates of a hydrophilic polysaccharide gum (G) and a hydrophobic stearic acid (S) with or without pretreatment with a hydrophobic humic acid (HA) Removal of OM reduced AS of unmodified soil by 40 and 20% after soil incubation for 7 and 40 d, respectively In both soil samples, AS was best at the highest rate of G (50 g kg 1 ) Its effect was better on Soil A (where OM was removed) than Soil B (where OM was retained) but diminished rapidly during 40 d At this rate, G increased AS by 750% in Soil A and by 335% in Soil B compared with no addition With S, aggregate stability increased more with time in Soil B than in Soil A Its maximum effect was also at the highest application rate (50 g kg -1 ), where AS increased 100% on Soil A and 131% on Soil B At the highest rate (02 g kg -1 ), HA increased AS by 73% on Soil B and 27% on Soil A The effect of HA alone did not vary with time Soil pretreatment with HA before addition of G reduced significantly both the state of aggregation and AS of both soils The reverse occurred when HA was applied before S After 40 d, S+HA increased AS in Soil B by 34%, whereas G and G+HA decreased AS by 14 and 4%, respectively We found that soil AS was improved and maintained with time more by hydrophobic than by hydrophilic components of organic matter Long-lasting aggregate stability of soils can be thus achieved by addition of hydrophobic humic material with hydrophobic organic wastes

Jaw fractures in Enugu, Nigeria, 1985-95.

Abstract: A retrospective analysis of 900 patients with jaw fractures of the facial bones during the period January 1985 - December 1995 indicated that 747(83%) resulted from road traffic accidents, 75(8.4%) from interpersonal violence, 39(4.3%) from accidents during sporting events, and 36(4%) from occupational accidents, while the causes of 3(0.3%) were not stated. The left side of the face was affected more often than the right. The mandible was twice as likely to be fractured as the zygomaticomaxillary complex. The symphysis-body-angle and the condylar region were the most common sites of fracture of the mandible, while the zygoma was the area most often affected in the middle third of the face. Most maxillofacial fractures occurred in the age group 21-30 years, and the lowest among those over 60. Three times as many men were affected as women. We conclude that there is high incidence of fractures of the facial bones caused by traffic accidents in our environment and, in all age groups, men were more likely to be affected than women.

Relationship of percolation stability of soil aggregates to land use, selected properties, structural indices and simulated rainfall erosion

Abstract: Simple tests of structural stability are needed for evaluating the ease with which soils slake and erode when in contact with water. In a laboratory study, we related the percolation stability (PS) of 22 Nigerian soils to land use, soil properties, structural stability indices and simulated rainfall erosion. All measurements were carried out with the 1–2 mm diameter air-dry aggregates. Land use influenced PS more than the type of soil. Forest soils, bush fallows, mulched, minimally tilled plots and pasture lands had rapid PS (>250 ml/10 min) values, whereas mulched conventionally tilled plots, bare fallows and continuously cultivated plots from where residues were removed by burning had relatively slow to moderate PS values (34–241 ml/10 min). The single most important soil property that correlated positively with PS is organic matter (OM) ( r = 0.55 * ) followed by total Fe + Al ( r = 0.52 * ). The significant inverse relationship ( r = −0.49 * ) between log (PS) and log (pH/OM) indicates a decrease in PS of these acidic, low-OM soils with increasing pH levels. The percent water-stable aggregate (WSA) >0.20 mm diameter, aggregated clay index (AC) and clay dispersion ratio (CDR) correlated weakly with PS. Conversely, the sealing index (SI) (i.e. the ratio of saturated hydraulic conductivity of an uncrusted to that of a crusted soil) had a strong, inverse relationship with PS ( r = −0.97 *** ). These relationships indicate that PS measures the slakability (and not dispersibility) of soils. The relationship between PS and erosion ( E ) was an exponential decay form, E = 102 e −0.0043PS ( r 2 = 0.98) and showed that high interrill erosion rates would be expected on soils with PS

Strategies for music education in Africa: towards a meaningful progression from tradition to modern

Abstract: There are three stage of music education in traditional Africa. The first stage inducts a new born baby into feeling the sensations of musical pulse and sound as a sympathetic participant till the ...

The physical and chemical responses of a degraded sandy clay loam soil to cover crops in southern Nigeria

Abstract: The physical and chemical responses of a degraded sandy clay loam Ultisol to two leguminous and four grass cover crops in southern Nigeria were studied after five years to assess the rejuvenative effects of the covers. There were relative increases of 26% and 112% in soil organic carbon and phosphorus levels and also appreciable improvements in the CEC and Ca levels under vegetative covers compared with the initial conditions. The improvements were more pronounced with legume covers than with grass covers. Furthermore, the vegetative covers improved mean organic carbon level by 28% and appreciably improved mean CEC, Ca, and Mg levels over the values for the bare soils. The percentage of water-stable aggregates >1.0 mm was significantly reduced under bare fallow ( $${\bar x}$$ = 27.7%) compared with soils under vegetative cover $${\bar x}$$ = 79.3%). The correlation between water-stable aggregates > 1.0 mm and exchangeable aluminum was negative and significant (r = −0.705°) at p = 0.05. There were highly significant treatment effects (P = 0.01) for penetrometer resistance, pore size distribution, water infiltration, water retention and saturated hydraulic conductivity. Grass and legume fallows which protect the soil and guarantee regular additions of organic materials are ecologically sound and socially acceptable components of sustainable agricultural production. Indications, however, are that this degraded tropical Ultisol would require a period exceeding five years under vegetative covers for restoration of its fertility to acceptable productive status.

Plasma aspartate aminotransferase activity in the catfish Clarias albopunctatus exposed to sublethal zinc and mercury.

Abstract: Aspartate aminotransferase (ASAT), like alanine aminotransferase, is a key enzyme in the protein to carbohydrate metabolism. It has wide distribution in both mammalian and fish tissues (Eze 1983; Gaudet et al., 1975). The enzyme may leak into the plasma following reservoir tissue damage or dysfunction. Hence, the assay has become an indispensable tool in the clinical determination of the pathological conditions of the reservoir tissues and organs (LaDue et al. 1954). The aquatic ecosystem remained the major recipient of industrial wastes like metallic irons, industrial solvents and contaminated run-off from the land without regard to the health of the aquatic ecosystem. Today, as result of increasing urbanization, expanding industrial and mining activities as well as modern agricultural enterprises, heavy metals in aquatic ecosystem are found in excess of natural load.

Studies on the antidiarrhoeal properties of pentaclethra macrophylla leaf extracts.

Abstract: The aqueous (WE) and ethanol (EE) leaf extracts of Pentaclethra macrophylla were tested for antidiarrhoeal activity using experimental animal models. The i.p. LD50 values were established to be 770 mg/kg and 280 mg/kg for the aqueous (WE) and ethanol (EE) extracts, respectively. Antidiarrhoeal potential of the extracts was evidenced by a significant reduction in faecal output and protection from castor oil-induced diarrhoea in rats treated with the extracts. In addition the extracts significantly (p < 0.05) decreased propulsive movement of gastrointestinal contents in mice. On isolated tissue preparations, the extracts significantly reduced in a non-specific manner contractions evoked by acetylcholine, nicotine and histamine. The extracts inhibited the growth of common pathogenic microorganisms. The antispasmodic as well as the antimicrobial effects of the extracts may explain the rationale for the use of the plant in traditional medicine as a popular antidiarrhoeal recipe. Copyright © 1999 John Wiley & Sons, Ltd.

The pharmacological effects of an aqueous extract from Acacia nilotica seeds.

Abstract: An aqueous extract of the seed of Acacia nilotica was investigated for its pharmacological profile. On the isolated guinea-pig ileum, the extract displayed sustained dose-related contractile activity. The contractions which were reduced by hexamethonium, promethazine or atropine were completely abolished by nifedipine. The intravenous (i.v.) administration of the extract (11, 22, 44, 55 microg/kg) to anaesthetized cats produced a dose-related significant elevation of blood pressure. The mechanisms of the spasmogenic and vasoconstrictor actions of the extract have not been determined, however, the results suggest the involvement of calcium.

Proximate composition and some functional properties of extrusion cooked soybean and sweet potato blends

Abstract: Mixtures of sweet potato flour and soy flour were made in a pilot mixer. They were moisturized with 18, 25, and 30% water and extruded in a single screw extruder at 80 rpm, using a die of 6mm. Extrusion temperature was maintained at 100 ± 3°C. Effects of adding soy flour into sweet potato flour, as well as variation in feed moisture on the composition and some functional properties of the extrudates were investigated. Increase in sweet potato content increased carbohydrate values. Protein increased with increase in soy flour. Feed moisture did not significantly ( p ≤ 0.05) affect extrudate composition. Increase in sweet potato content and feed moisture increased expansion ratio. Bulk density decreased with decrease in feed moisture, but increased with increase in soy flour. Starch content increased as sweet potato content increased. Degree of gelatinization increased with sweet potato content. Lower feed moisture enhanced gelatinization. Water absorption index (WAI) increased as sweet potato content increased. Feed moisture had a slight effect on WAI and water solubility index (WSI). Amylose increased with increase in sweet potato content. Increase in soy flour led to an increase in yellowness (b*) of extrudates.

Iterative solutions of nonlinear accretive operator equations in arbitrary Banach spaces

Abstract: Suppose E is an arbitrary real Banach space and K is a nonempty closed convex and bounded subset of E. Suppose T : K —>• K is a uniformly continuous strong pseudocontraction. It is proved that the Mann and the Ishikawa iteration methods converge strongly to the unique fixed point of T. Furthermore, our results also hold for the slightly more general class of strictly hemicontractive maps. Related results deal with the iterative approximation of solutions of accretive operator equations in arbitrary real Banach spaces. MIRAMARE TRIESTE April 1996 Permanent address: Department of Mathematics, University of Nigeria, Nsukka, Nigeria.

Soil water relations of a Nigerian typic haplustult amended with fresh and burnt rice-mill wastes

Abstract: The soils in the Abakaliki agro-ecological region of southeastern Nigeria are plagued with characteristics that impede optimal soil water conditions. Four rates (12.5, 25.0, 37.5 and 50.0 Mg ha −1 ) of fresh (FW) and burnt (BW) rice-mill wastes were incorporated in a typic haplustult planted with maize ( Zea mays L.) to improve the immediate and long-term water conditions of the soil. Results showed that significant changes in bulk density and total porosity occurred at the application rates of 25.0 and 50.0 Mg ha −1 in the FW and BW amendments, respectively. At an application rate of 50.0 Mg ha −1 , the permanent wilting point water content (18.0%) in the FW amendment was significantly higher than the BW amendment. Similarly, the FW amendment at the same application rate resulted in the infiltration rates (i) of 2250 and 2181 mm h −1 in the first and second seasons, respectively. These figures are significant improvements relative to the BW amendments and the control. Percent organic carbon (OC), dry aggregate size >0.5 mm and water stable aggregates (WSA) > 0.5 mm accounted for 43% and 77%, respectively of the improved infiltration. Sorptivity and A parameter of Philip's equation increased significantly with increasing rate of the FW amendment. Appropriate moisture conservation techniques are required to accelerate the rate of decomposition of the FW amendment in order to enhance its contribution to soil water retention.

In vitro adsorption of ciprofloxacin on activated charcoal and Talc.

Abstract: The in vitro adsorption of ciprofloxacin, a broad-spectrum antimicrobial with actions against a wide variety of microorganisms on activated charcoal (AC) and talc (TC), was investigated at various pH values that simulate the pH of most regions of the gastrointestinal tract. The results of the study indicate that AC and TC adsorbed ciprofloxacin effectively. Adsorption depended on the quantity of the adsorbents used, and for AC adsorption was complete within 2 hours and for TC it was complete within 1 hour with 0.5 g of either of the adsorbents. AC exhibited higher adsorptive capacity for ciprofloxacin than TC. Overall, AC and TC could be used as effective antidotes in poisoning resulting from ciprofloxacin.

Studies on anti-ulcer properties of Cissampelos mucronata leaf extract.

Abstract: The methanolic extract of the leaves of C. mucronata was screened for anti-ulcer properties using animal models. On isolated guinea pig ileum the extract inhibited contractions evoked by acetylcholine, histamine and serotonin. The extract remarkably decreased the propulsive movement of gastrointestinal content. The extract exhibited significant anti-ulcer activity protecting rats from indomethacin, histamine and stress-induced ulcers. It inhibited the growth of both Gram-positive and Gram-negative microorganisms. The oral LD50 value of the extract in mice was estimated to be 8.5 +/- 0.35 g/kg. The results revealed that the plant C. mucronata has potential medicinal value as an anti-ulcer agent.

Foreign banks, Africans, and credit in colonial Nigeria, c. 1890‐1912

Abstract: S ince the mid-1970s very little research has been done on the subject of colonial banks in British West Africa.2 Until then, however, the subject had received enormous attention from researchers,3 whose work has in no small way contributed to our understanding of the origins and practices of these foreign banks. In particular, it is now widely accepted, for instance, that foreign banks in colonial West Africa lent much less to Africans (individually and corporately) than they did to the Europeans and that most of the credit received by Africans was obtained from nonbank sources. There is also fairly widespread agreement as to the reasons for the unhelpful attitude of the foreign banks. These include the lack of unambiguous title to assets that might otherwise have been used as collateral, the relatively high cost of handling large numbers of individually small transactions, and the high rate of bad debts experienced with African transactions. Perhaps the most contentious reason for the unhelpful attitude of the colonial banks is racial prejudice.4 To these factors already established in the literature, this article adds evidence of change and contingency. Specifically, it shows that foreign banks' policies on lending to Africans varied according to the particular interests of their shareholders. Using correspondence and testimonies given to commissions of inquiry, the article shows that the first British bank to establish itself in colonial Nigeria, the African Banking Corporation (later to become the Bank of British West Africa (BBWA)), was keen to lend to Africans as well as Europeans. It was challenged by a later entrant, Anglo African Bank (later to become the Bank of Nigeria), which was founded by interests closely linked to a powerful combine of British merchant houses. It will be shown that these British trading interests saw their new bank as a means to help preserve barter trade5 and their monopolistic position in the export-import trade, a position which, as they perceived it, required that Africans be denied access to

Late presentation of orofacial tumours

Abstract: One hundred and twenty-eight cases of tumours involving the oral and the maxillofacial region and the oropharynx were reviewed. The objective was to highlight the late presentation of orofacial tumours in Nigeria. Patients who presented with squamous cell carcinoma, ameloblastoma, Burkitt's lymphoma, fibrous dysplasia and pleomorphic adenoma between January 1993 and December 1997 were selected. The socio-economic class of each patient was noted. Ignorance and poverty were the main reasons for the late presentation of 120 patients who belonged to the lower social class. Four middle-class patients and four upper class ones gave marital problems and a sense of despair as reasons for the delay in seeking treatment. Difficulties in their management are attributed to the advanced stage of the tumours and the high rate of patients' default. There is the need to emphasize not only the necessity for early presentation but also the establishment of adequate facilities in this country, and other developing countries, for effective treatment of these tumours.