Showing papers by "University of Nigeria, Nsukka published in 2001"

Treatment of childhood fevers and other illnesses in three rural Nigerian communities.

Abstract: The seeking of health care for childhood illnesses was studied in three rural Nigerian communities of approximately 10000 population each. The aim was to provide a baseline understanding of illness behavior on which to build a program for the promotion of prepackaged chloroquine and cotrimoxazole for early and appropriate treatment of childhood fevers at the community level. A total of 3117 parents of children who had been ill during the 2 weeks prior to interview responded to questions about the nature of the illness and the actions taken. Local illness terms were elicited and the most prevalent recent illnesses were hot body (43.9%) malaria (known as iba) (17.7%) and cough (7.4%). The most common form of first-line treatment was drugs from a patent medicine vendor or drug hawker (49.6%). Only 3.6% did nothing. Most who sought care (77.5%) were satisfied with their first line of action and did not seek further treatment. The average cost of an illness episode was

Carbohydrates in water-stable aggregates and particle size fractions of forested and cultivated soils in two contrasting tropical ecosystems

Abstract: Information on changes in storage and loss of soil organic carbon (SOC) when tropical forests are converted to cropland is needed for evaluating soil structural degradation and for selecting appropriate sustainable soil management practices. We evaluated changes in SOC storage of organic carbon and acid-hydrolyzable carbohydrates content of aggregated classes and particle size fractions of adjacent forested and cultivated soils in eight agroecosystems from Ethiopian highlands and Nigerian lowlands. In all agroecosystems, SOC content was two to four times higher in the forested than the cultivated soils. Higher SOC content was found in Ethiopian (20.2–47.3 g.kg−1) than Nigerian (12.0–24.0 g.kg−1) forested soils. The magnitude of reduction in SOC and total carbohydrates with cultivation was soil-specific, being generally higher in the sandy than the clayey soils. The smaller aggregate classes (< 1.00 mm) and the sand-sized particles (2000–63 µm) of the forested soils were preferentially enriched in carbohydrates relative to larger aggregates (4.75–1.00 mm). Carbohydrates were more concentrated in the clay-size fraction of the forested than in that of the cultivated soils. Cultivation reduced aggregate stability, increased the proportions of the smaller size aggregates and their associated carbohydrates relative to the forested soils. The susceptibility of the cultivated soils to loss in structural stability reflected this initial aggregation which was greater in the more stable clayey than the fragile sandy soils. The aggregate stability of either the forested or the cultivated soil could not be accounted for by the levels of OC or total carbohydrates in the soil.

Compliance to correct dose of chloroquine in uncomplicated malaria correlates with improvement in the condition of rural Nigerian children

Abstract: Non-compliance to correct dosing is thought to be one of the main causes of treatment failure of chloroquine in the home management of childhood malaria. There are few studies of compliance to drugs used for tropical diseases. In order to study compliance in the rural setting, chloroquine syrup was packaged with a novel pictorial insert for compliance to correct dosing. Compliance was assessed in a field trial in September 1996–December 1997, involving 632 children with uncomplicated malaria in Udi local government area in Nigeria. Written informed consent was obtained from mothers/guardians before children were enrolled in the study. There were 3 arms to the trial: control villages (group I) received chloroquine syrup without further intervention, group II received a pictorial insert with chloroquine syrup, and group III received chloroquine syrup, the pictorial insert and verbal instructions. Each group was made up of 3 health centres. Compliance was assessed by volumetric measurement of the chloroquine syrup left in 30-mL bottles and by questionnaires administered to mothers/helpers of the children. Control villages recorded full compliance for 36·5 ± 4·4% of the children, group II for 51·9 ± 7·9% and group III for 73·3 ± 4·2%. There was a significant correlation (P

Iterative solution of nonlinear equations involving set-valued uniformly accretive operators

Abstract: Let E be a real normed linear space and let A : E ↦ 2 E be a uniformly continuous and uniformly quasi-accretive multivalued map with nonempty closed values such that the range of ( I – A ) is bounded and the inclusion f ϵ Ax has a solution x * ϵ E . It is proved that Ishikawa and Mann type iteration processes converge strongly to x *. Further, if T : E ↦ 2 E is a uniformly continuous and uniformly hemicontractive set-valued map with bounded range and a fixed point x * ϵ E , it is proved that both the Mann and Ishikawa type iteration processes converge strongly to x *. The strong convergence of these iteration processes with errors is also proved.

Distribution and movement of sludge-derived trace metals in selected Nigerian soils.

Abstract: Use of metal-rich sewage sludge as soil fertilizer may result in trace- metal contamination of soils. This study was conducted to evaluate the effects of long-term sludge application on trace-metal (Zn, Cu, Pb, and Ni) distribution and potential bioavailability in Nigerian soils under a tropical wet-dry climate. Total metal analyses, sequential chemical fractionation, and DTPA extractions were carried out on samples of control and sludge-amended pedons in Nigeria (a Rhodic Kandiustult and two Rhodic Kandiustalfs from Nigeria, respectively). The sewage sludge applied to the soils contained higher levels of Zn and Cu than Pb and Ni. The control pedon contained low levels of all four metals. Soil enrichment factors (EF) were calculated for each metal in the sludge-amended pedons. Compared with the control soil, the sludge-amended pedons showed elevated levels of Zn and Cu, reflecting the trace-metal composition of the sewage sludge. Zinc and Cu in the sludge-amended soils were strongly enriched at all depths in the profile, indicating that they had moved below the zone of sludge application. The sequential extraction and DTPA analyses indicated that the sludge-amended soils contained more readily extractable and bioavailable metal ions than the unamended soil.

Hypothetical and actual willingness to pay for insecticide-treated nets in five Nigerian communities

Abstract: OBJECTIVES To determine the hypothetical and actual willingness of households to pay (WTP) for insecticide-treated nets (ITNs), and compare these in areas with and without previous exposure to free ITNs. METHODOLOGY The contingent valuation method was used to determine the willingness of the heads of 1908 randomly selected households from five communities in south-east Nigeria to pay for two sizes of ITNs. Two communities previously had free access to ITNs. Validity was assessed using multiple regression analyses, and by offering ITNs for sale to 200 randomly selected people drawn from the original sample. The data was collected between March and September 1998. FINDINGS Most respondents were willing to pay for ITNs: Mbano (93.26%), Ugwogo (97.69%), Orba (83.24%), Alor-uno (95.37%), and Ibagwa-ani (87.34%). In multivariate analyses, WTP was significantly associated with the number of people living in a household, sex of the respondent, average yearly expenditure on gifts and the type of savings scheme (P < 0.05). Some of the residences were also statistically significant in the two models used, and those with prior exposure to free ITNs were negatively related to WTP. Seventy-six percent of those who were hypothetically willing to pay actually purchased them, and the WTP technique correctly predicted the choices of 80% of the respondents. CONCLUSION There was good evidence that stated WTP could be translated into actual WTP. However, peoples' perception of affordability of the nets and its link to their WTP needs further exploration. The WTP technique is a potentially valid tool for market research in healthcare, as it was able to predict the direction of actual WTP for the ITNs. The hypothetical WTP amounts could be used as guide to know either the optimal price to charge for the ITNs or the level of subsidy to introduce.

Evidence for Free Precession in the Pulsar B1642-03

Abstract: We present an analysis of the timing data of the pulsar B1642-03, collected over a span of 30 years between 1969 and 1999. During this interval, the timing residuals exhibit cyclical changes with amplitude varying from 15 to 80 ms and spacing of maxima varying from 3 to 7 yr. Interpretation of these observed cyclical changes in terms of free precession suggests a wobble angle of about 08.

Determinants of Health and Nutritional Status of Rural Nigerian Women

Abstract: This study was undertaken to determine the effects of socioeconomic and cultural factors on the health and nutritional status of 300 women of childbearing age in two rural farming communities in Enugu State, Nigeria. The women were engaged in farming, trading, and teaching. A cross-sectional survey was conducted using both qualitative and quantitative data-collection methods. The study involved focus-group discussions (FGDs), interviews using a questionnaire, measurement of food/nutrient intake, assessment of activity patterns, anthropometry, and observations of clinical signs of malnutrition. The better-educated women had higher incomes than those with little or no education. Poor education was mainly attributed to lack of monetary support by parents (34%), marriage while in school (27%), and sex discrimination (21%). The teachers had significantly (p < 0.05) better health status, health and nutrition knowledge, food habits, nutrient intake, and self-concept, and adhered less to detrimental cultural practices. However, none of the women met their iron, riboflavin and niacin requirements. More cases of chronic energy deficiency were observed among the farmers (16%) and traders (13%) than among the teachers (5%). Generally, the women worked long hours with reported working hours (6-7 hours) being lower than the observed working hours (11 hours) for the traders and teachers. Income had a significant (p < 0.05) positive correlation with all nutritional variables, except vitamin C, age-at-marriage (r = 0.719), and nutrition knowledge (r = 0.601). Age-at-marriage had a positive correlation with body mass index (BMI) and all nutritional variables but was significant (p < 0.05) for protein (r = 0.362), calcium (r = 0.358), iron (r = 0.362), riboflavin (r = 0.364), and vitamin C (r = 0.476). Workload was negatively correlated with protein intake (r = 0.346; p < 0.05). Meal frequencies for more than 70% of the farmers and petty traders and 42% of the teachers were dependent on the availability of food in the household. Food taboos had no effect on their nutrient intake, since only 5-11% of women adhered to taboos. Although most women gave their children and husbands preference in food distribution, not much difference was found in the amount of food consumed by these women. The ratio of wife's portion to husband's was 1:1.4 for the farmers, 1:1.3 for the traders, and 1:1.2 for the teachers. FGDs revealed that sex discrimination in education prevailed where resources were limited. The results of the study suggest that the basic determinants of health and nutritional status of women are socioeconomic and cultural, education having a mediating or modifying influence on cultural practices.

Knowledge, attitude and practice of family planning amongst women in a high density low income urban of Enugu, Nigeria.

Abstract: A total of 334 Nigerian, non-pregnant women, living in a high density, low-income urban area of Enugu, Nigeria, were interviewed on knowledge, attitude and practice of family planning. About 97.6% were found literate. Knowledge and approval of family planning was high, 81.7% and 86.2% respectively, but the practice of family planning was low, as only 20% of the women were on a family planning method. The commonest methods for both ever use and current use were safe period/Billings, condom, IUCD and injectables. The commonest source of family planning information was health workers, while the commonest single reason for non-practice of a method was rejection by the husband. It is concluded that despite their high level of education/literacy, with the attendant high knowledge and approval rate of family planning, the socio-cultural influence of men on their wives is a major stumbling block to the use of modern family planning in this part of Nigeria. Policy makers should, therefore, increase male involvement in family planning programs. (Afr J Reprod Health 2001; 5[2]: 83-89) RESUME Connaissance, attitude et pratique du planning familial chez les femmes du centre urbain d'Enugu de haute densite et d'une population des gens economiquement faibles. 334 femmes nigerianes qui n'etaient pas enceintes et qui vivaient dans un centre urbain economiquement faible ont ete interviewees sur la connaissance, l'attitude et la pratique du planning familial. Il s'est trouve qu a peu pres 97,6% etaient lettrees. La connaissance et l'approbation du planning familial etaient elevees, 81,7% et 86,2% respectivement, mais la pratique du planning familial etait faible,puisqu'il n'y avait que 20% des femmes qui pratiquaient le planning familial. Les methodes des plus communes jamais utilisees ou qu'elles utilisent a l'heure actuelle etaient la periode sans danger/methode Billings, les preservatifs, DIU et les injectables. Les membres du personnel de sante constituaient la source la plus importante du renseignement sur le planning familial alors que la raison la plus commune qui explique la non pratique d'une methode quelconque etait que le mari ne l'approuvait pas. L'etude conclut en affirmant que malgre leur haut niveau de scolarisation/alphabetisation, la haute connaissance et le taux d'approbation du planning familial, l'influence socio-culturelle des hommes sur leurs femmes demeure un obstacle majeur a l'utilisation du planning familial moderne dans cette region du Nigeria. Les decideurs doivent, en consequence, redoubler le role que jouent les hommes dans les programmes de planning familial. (Rev Afr Sante Reprod 2001; 5[2]: 83-89) KEY WORDS : Family planning, socio-cultural factors, Enugu, Nigeria

Etiology of dermatophytoses amongst children in northeastern Nigeria

Abstract: A survey of dermatophytoses was carried out amongst primary school children in Borno State, Nigeria, during February 1997 to January 1998. A total of 2,193 children aged 4-16 years were screened. Out of these, 154 (7.0%) were proved to be mycologically positive by microscopy, culture or both. Incidence was significantly higher (P <0.05) in young children aged 7-11 years (8.1%) and 4-6 years (6.9%) than in older children aged 12-16 years (3.6%). There was a significant difference in the incidence of dermatophytoses amongst children in urban and rural areas (P <0.05). Tinea capitis was the predominant clinical type followed by tinea corporis. Trichophyton schoenleinii was the most prevalent etiological agent (28.1%), followed by T. verrucosum (20.2%) and Microsporum gallinae (18.4%). Other species recovered included T. mentagrophytes (16.7%), T. tonsurans (10.5%), T. yaoundei (4.4%) and M. gypseum (1.8%).

Maternal mortality at the University of Nigeria Teaching Hospital, Enugu, before and after Kenya.

Abstract: A comparative retrospective analysis of maternal deaths at the University of Nigeria Teaching Hospital, Enugu, Nigeria, was carried out for two ten-year periods ? 1976-1985 and 1991-2000 ? in order to evaluate the effect of Safe Motherhood Initiative on maternal mortality in the hospital. Variables for the two periods were compared by means of the t-test at 95% confidence level. Maternal mortality ratio was significantly higher in Period II than in Period I (1406 versus 270 per 100,000; p = 0.00). The leading causes of maternal death were uterine rupture for Period I and septicaemia for Period II. Although from the first to the second ten-year period there was a significant decrease in the number of midwives, physicians and nurse anaesthetists, there was more than a proportionate decrease in the number of deliveries. There was also increase in the incidence of anaemia due to diminished standards of living and in the mean decision-intervention interval (1.5 ± 0.5 versus 5.8 ± 1.2 hours; p = 0.000) as a result of worker dissatisfaction and changes in hospital policies. We conclude that since the launching of the Safe Motherhood Initiative, MMR at the University of Nigeria Teaching Hospital, Enugu, Nigeria, has increased five-fold as a result of institutional delays and a deterioration in the living standards of Nigerians, both consequences of a depressed economy. To halt this trend, we recommend that the living standard of all Nigerians should be improved. Furthermore, healthcare personnel should be motivated through enhanced salaries and provision of working materials including efficient mobile telephone services. (Afr J Reprod Health 2001; 5[2]: 90-97) RESUME Mortalite matrenelle au Centre Hospitalier Universitaire a Enugu, Nigeria: Avant et apres le Kenya. Une analyse retrospective comparee des deces maternels au Centre Hospitalier Universitaire a Enugu au Nigeria a ete faite au cours de deux periodes de dix ans chacune, 1976-1985 et 1991-2000. Le but de l'analyse etait d'evaluer l'effet de la Safe Motherhood Initiative sur la mortalite maternelle dans l'hopital. Des variables pour les deux periodes ont ete comprares a l'aide du test de t a un niveau de confiance de 95%. Le rapport de mortalite maternelle etait, de maniere significative, plus eleve dans la periode II que dans la Periode I (1406 par opposition a 270 par 100,000, p = 0,00). Les causes principales du deces maternel etaient la rupture de l'uterine pour la Periode I et la septicemie pour la Periode II. Bien que depuis la premiere jusqu'a la deuxieme periode de dix ans il y ait une baisse significative dans le nombre de sages-femmes, de medecins et d'infirmieres anesthesistes, il y avait plus qu'une baisse proportionnelle dans le nombre d'accouchements. Il y avait egalement une augmentation de l'incidence d'anemie a cause du niveau de vie baisse et dans l'espace de la moyenne decision-intervention (1,5 ± 0,5 par opposition a 5,8 ± 1,2 heures; p = 0,000) a cause du mecontentement chez les salaries et des changements dans la politique de l'hopital. Nous concluons que depuis qu'on a lance la Safe Motherhood Initiative, le taux de mortalite maternelle a augmente cinq fois au Centre Hospitalier Universitaire a Enugu, Nigeria, a cause des delais institutionnels et a cause de la deterioration du niveau de vie des Nigerians, deux consequences d'une economie en declin. Pour mettre fin a cette tendance, nous recommandons que le niveau de vie de tous les Nigerians soit ameliore. En plus, les membres du personnel du service de sante doivent etre motives a travers les salaires augmente et en mettant a la disposition des membres du personnel tous les materiels du travail y compris les services du telephone portable. (Rev Afr Sante Reprod 2001; 5[2]: 90-97 ) KEY WORDS : Increasing, maternal mortality ratio, Enugu, Nigeria, Kenya

Amino Acid and Protein Dispersibility Index (PDI) of Mixtures of Extruded Soy and Sweet Potato Flours

Abstract: Selected samples of defatted soy flour, sweet potato flour, and their blends were extruded in an Almex-150 single screw extruder. Effects of extrusion cooking were verified with respect to amino acid profile and protein dispersibility indices of the samples. Amino acid contents of soy flour as well as that of sweet potato flour were more drastically reduced by extrusion than those of their mixtures. Protein dispersibility indices of the samples increased with increase in sweet potato proportion in the blends.

Purification and some properties of a novel raw starch-digesting amylase from Aspergillus carbonarius

Abstract: A medium was developed to obtain the maximum yield of raw starch-digesting amylase from Aspergillus carbonarius (Bainier) Thom IMI 366159 in submerged culture with raw starch as the sole carbon source. The amylase was purified to apparent homogeneity by sucrose concentration and ion exchange chromatography on S- and Q-Sepharose (fast flow) columns. SDS-PAGE revealed two migrating protein bands corresponding to relative molecular masses of 31.6 and 32 KDa. The enzyme was optimally active at pH 6.0–7.0 and 40 °C, was uninfluenced across a relatively broad pH range of 3.0–9.0 and retained over 85% activity between 30 and 80 °C after 20 min incubation. The enzyme was strongly activated by Co2+ and only slightly by Fe2+, while Ca2+, Hg2+, EDTA and N-bromosuccinamide elicited significant repression of the enzyme activity. The enzyme hydrolysed amylopectin (Km 0.194 mg ml −1), glycogen (Km 0.215 mg ml −1), pullulan (Km 0.238 mg ml −1), amylose (Km 0.256 mg ml −1) and raw potato starch (Km 0.260 mg ml −1), forming predominantly maltose and relatively smaller amounts of glucose. © 2000 Society of Chemical Industry

Searching for a better willingness to pay elicitation method in rural Nigeria: the binary question with follow-up method versus the bidding game technique.

Abstract: Objectives: To compare the theoretical validity and predictive validity of the binary with follow-up questions technique and the bidding game, using hypothetical and actual WTP for insecticide-treated nets (ITNs) in Nigeria. Methods: Each elicitation method was applied in one of two rural communities in Enugu state, Nigeria. A pre-tested interviewer-administered questionnaire was administered to household heads or representatives of households. WTP was elicited in each after presenting the scenario and showing a sample of the ITNs to the respondents. Then, within an interval of 1–2 months, the nets were sold to the respondents to compare hypothetical and actual WTP. Findings: Consistent slightly higher mean and median WTP amounts were elicited from Mbano where the bidding game was used. The WTP technique was able to predict WTP responses correctly in 75% and 85% of cases in Orba and Mbano, respectively. Chi-square analysis did not show any statistical difference in values from both communities (p>0.05). Conclusion: Though the two techniques yielded similar results, the thrust should be the development of a WTP elicitation method that best mimics the bargaining process in normal market situations in rural Nigeria. Such an indigenous technique will help improve the predictive validity of the contingent valuation method. Copyright © 2001 John Wiley & Sons, Ltd.

Analysis of Socioeconomic and Environmental Impacts of Waste Stabilization Pond and Unrestricted Wastewater Irrigation: Interface with Maintenance

Abstract: The effluent from the waste stabilization ponds (WSPs) of the University of Nigeria, Nsukka Campus, is used for irrigation by poor rural farmers. There has been fear that the poorly maintained WSPs and the reuse practices are contributing to environmental degradation and health hazards. In this study the environmental and socioeconomic impacts of the WSPs and reuse were evaluated based on data collected from questionnaires and the literature. The engineering and agricultural properties of soil in the irrigated and nonirrigated areas were compared. Comparison of the health status of the farmers and nonfarmers, of consumers of crops irrigated with wastewater and nonconsumers was performed using Student's t test and the z-score test. The occurrences of diarrhea, typhoid fever, and malaria among the various groups were used as indices. Analyses show that the health status of the farmers and consumers is poorer than those of nonfarmers and nonconsumers at the 5% level of significance. Vegetable cultivation using WSP effluent is a means of sustenance to the farmers and provides an affordable means of satisfying their nutritional deficiencies. However, the poorly maintained WSPs create odor and mosquito nuisances, trap and destroy livestock, and flood nearby compounds with waste debris. At both 1% and 5% levels of significance, communities around the ponds (<300 m) suffer malaria more frequently than those who live far away (?300 m). Cost–benefit analysis argues in favor of improvement of WSP management and irrigation reuse of wastewater. Dredging of the ponds, training workers and farmers, and adopting appropriate maintenance and monitoring strategies will greatly enhance the socioeconomic status of the urban poor farmers.

Structural stability and carbohydrate contents of an ultisol under different management systems

Abstract: An understanding of the dynamics of soil carbohydrate pools is necessary for assessing the impact of organic residue management in organic matter build up and structural stability in tropical ecosystems. The objectives of this study were to evaluate temporal changes in aggregate stability and cold water-soluble, hot water-soluble and acid-soluble carbohydrate fractions of a sandy soil under different organic residue management practices. The soil is an Nkpologu sandy clay loam (fine-loamy, kaolinitic, isohyperthermic, typic kandiustult) at Nsukka in southeastern Nigeria. In July 1995, it was incorporated with complete fertiliser (N:P:K = 12:12:17 at 480 kg/ha) (F); rice mill wastes (RW, 10 t/ha); RW+F; poultry manure (PM, 10 t/ha) and RW (5 t / ha )+ PM (5 t / ha ) up to the 0–20 cm depth. A control, tilled up to the 0–20 cm depth, was also included. Surface soil samples (0–20 cm), collected at 3, 6 and 12 months after residue applications were used to measure changes in aggregate stability by mean weight diameter (MWD), total OC and carbohydrate pools. In all treatments MWD increased whereas the concentrations of acid-soluble, hot water-soluble and cold water-soluble carbohydrates decreased with sampling time. Also irrespective of the type of amendment, the carbohydrate concentrations at each sampling period varied in the order, acid - soluble > hot water - soluble > cold water - soluble . Aggregate stability correlated very poorly with all the carbohydrate fractions and OC. The correlation coefficient values were rather low and did not mean much in the physical interpretation of these results. This shows that these carbohydrate pools were not very effective in stabilizing the soil aggregates.

Otomycosis in Nigeria: treatment with mercurochrome.

Abstract: Seventy-two mycologically proven cases of otomycosis (38 males, 34 females) aged 8-80 years were investigated. Aspergillus niger was the commonest aetiological agent (43.1%) followed by Candida spp. (22.2%), A. flavus (19.4%) and A. fumigatus (15.3%). Three topical drugs, namely mercurochrome, clotrimazole and locacorten-vioform, were evaluated for otomycosis therapy in separate groups of 24 patients each. Mercurochrome was found to be the most efficacious in terms of healing, relief from symptoms of the disease and production of negative fungal cultures. Mercurochrome is recommended as a safe and economical drug for the topical treatment of otomycosis in developing countries like Nigeria.

The theory of regulation: A review article

Abstract: This paper examines the various theoretical issues in regulation with a view to enhancing understanding of the regulation arena. Special emphasis has been placed on the banking industry. The paper shows how regulation serves different purposes for different interest groups on different occasions. It further argues that because of the ever shifting concept of ‘public good’, shifting individual and group interest and, perhaps the entwinement of individual and public good, neither the capture theory or the public good theory has yet fully explained the rationale for regulation. A clear understanding of the theoretical issues involved in regulation is therefore important if the forces that drive regulation are to be appreciated fully.

Marketing of banking services in Nigeria

Abstract: This paper (which was originally presented at the 2001 World Services Congress in Hong Kong, 19–21 September) traces the origins of marketing in Nigerian banking and shows how different economic, social and political environments have influenced the marketing of financial services in Nigeria. It argues that the future of the banking market in Nigeria will, in the main, depend on the ongoing integration of the country into the global market. With the return of the international banks, multinational and foreign companies and missions are likely to favour such banks for their banking transactions. The implication of this is that banks with little or no foreign ownership structures will gradually be forced to concentrate on the indigenous market. Unless the government can put its house in order quickly and ensure a stable macroeconomic environment for economic development, it is likely that market forces will cause several of these indigenous banks to merge their activities or be absorbed by the big international banks.

Residence Time Distribution in a Single-Screw Extruder Processing Soy-Sweet Potato Mixtures

Abstract: The influence of feed composition, screw rotation speed and die diameter on residence time distribution of soy-sweet potato samples containing 180 g/kg water and extruded in a single-screw extruder, was measured using congo red as a tracer. Mean residence and plug flow times respectively decreased with starch content. Increase in screw speed enhanced break through time, while a decrease in screw speed enhanced mean residence time. Die diameter had an effect on plug flow time only. The dispersion number, a reciprocal of the Peclet number, was used to describe the extent of axial mixing in the extruder. The value of dispersion number varied from 0.024 to 0.060.

Extrusion cooking of blends of soy flour and sweet potato flour on specific mechanical energy (sme), extrudate temperature and torque

Abstract: Defatted soy flour and sweet potato flour containing 18% moisture were mixed in a pilot mixer, and extruded in an Almex-Bettenfeld single-screw extruder operated at varying rotational speed and die diameter. A central composite, rotatable nearly orthogonal design, which required 23 experiments for three factors (feed composition (fc), screw speed (ss) and die diameter (dd)) was developed and used for the generation of response surfaces. Effects of the extrusion variables on specific mechanical energy (SME), extrudate temperature (ET), and torque (T) were evaluated using response surface analysis. Results showed that product temperature increased with increases in die diameter, screw speed and feed composition. However, the effect of die diameter was greater than those of screw speed and feed composition. Decrease in die diameter with increase in sweet potato content increased torque. Screw speed exhibited a linear effect on torque. Cette etude examine le procede d'extrusion d'un melange de farine de soja et de pomme de terre douce dans un extrudeur a simple vis. Les effets des variables d'extrusion sur l'energie mecanique specifique, la temperature du produit et le couple moteur sont evalues par analyse des surfaces de reponses. La composition du produit a un effet plus important que le diametre de la matrice sur l'energie mecanique specifique. La temperature du produit augmente avec le diametre, la vitesse de la vis et la composition du produit.

Comparison of the protein nutritional value of food blends based on sorghum, bambara groundnut and sweet potatoes

Abstract: The protein quality of four blends based on sprouted sorghum, bambara groundnuts and fermented sweet potatoes had been evaluated by rat feeding experiments; casein served as a reference protein. The test proteins were incorporated to make up 1.6% total nitrogen. There was an inverse relationship between % nitrogen disgestibility and the proportion of sorghum protein in the blend; being highest (89.7%) in the diets based on sorghum:bambara groundnut:sweet potatoes with protein ratios of 52:46:2. This blend proved to be optimum when the biological value (93.6%) and the net protein utilization (84%) were used as protein indices. The findings imply that foods with good protein quality could be formulated from a blend of sorghum-bambara groundnut and sweet potatoes, provided appropriate processing and blending are taken into consideration.