Key aspects of an effective surgical curriculum for medical students

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The Indigenous Aliens: The Case of the Igbo in Nigeria, 1953 – 2013

There exist commendable great strides in the studies of the Igbo especially since the end of the Nigerian Biafran  War in 1970.  In spite of this plethora of literature on Igbo studies, there exist yet vistas awaiting historical interrogation and or re-interpretations.  Since the end of the ill-fated Biafran experiment, Ndigbo have continued to be seen and treated as indigenous-foreigners in Nigeria especially in some parts of the North.  This brings about the relative deprevation theory where the Igbo successes in business and other endeavours are believed to be occasioned by deprivation suffered by their host community.  The relative deprivation theory has engendered dispossessionist tendency in the psyche of some individuals who forment ethno-religious crises in order to appropriate immovable investments of Ndigbo outside Igboland.   In other words, this feeling of deprivation has characterized the relationship between Ndigbo and their host community; a development which is everything but cordial.  The paper avers that the experiences of Ndigbo in the larger Nigerian society especially in the North have remained more or less the same with those of the pre-war years.  It also affirms that the vicious and unprovoked attacks on the Igbo and their property are but a subtle way of continued persecution of those regarded as indigenous aliens in their fatherland. Keywords: Indigenous Aliens, Deprivation, Citizenship, Domination and Aggressio

Comparative Toxicity Assessmentof Aqueous and Ethanolic Bark Extracts of Mahogany: Khaya grandifoliolaon Mangrove Periwinkle; Pachymelania aurita

The acute toxicities of extracts of Bark of Mahogany (Khaya grandifoliola) in aqueous and ethanolic solutions were evaluated against the edible periwinkle (Pachymelania aurita) in laboratory bioassays. From the derived toxicity indices, the aqueous extract (96h LC50 = 17.4ml/L, 3.48g/L) was found to be 24.2 times less toxic than the ethanolic extracts (96h LC50 = 0.24ml/L, 0.144g/L). ANOVA showed significant differences in the response of Pachymelania aurita to different concentrations of exposure to extracts at 48hr, 72hr and 96hr respectively. Symptoms of toxicosis observed in the test organisms were immobility and eventually death. Keywords: Toxicity, Pachymelania aurita, Khaya grandifoliola, Edible periwinkle, Lagos lagoon. DOI: 10.7176/JBAH/10-7-02 Publication date: April 30th 202

Geophysical Investigation of Some Flood Prone Areas in Ota, Southwestern Nigeria

Thirteen shallow vertical electrical resistivity soundings using Schlumberger array were conducted within the study area. The aim of the study was to investigate the nature of the subsurface in some flood prone areas within the study area by determining the lithology and the corresponding inverse model resistivities at the depths investigated and hence the cause of flooding in the area during the wet season. The resistivity sounding data were collected along seven traverses using a Campus Tigre terrameter. The observed data were interpreted quantitatively using curve matching and computer assisted iteration method. The results of the inversion show a lithology that comprises of the top soil and a paralic sequence of sand and lateritic clay at the depth investigated with varied resistivity and thickness. The flooding is thought to be due to the shallow lateritic clay layer at an average depth of 5.2 m with thickness ranging from 14.5m to 31.8m at the various points of investigation and the shallow depth of the water tabl

Treatment of Brewery Waste Water in a Fluidized Bed Digester

This study examined anaerobic fluidized- bed reactor performance employed to treat brewery waste water in terms of treatment efficiency on COD and BOD5 reduction under different hydraulic retention time (HRT). It employed a fluidized-bed digester, with liquid volumetric flow rate of 1.7 x 10-6m3/s, superficial velocity of 0.0012 m/s and 0.00026m/s which achieved the velocity  required to fluidize 20g activated carbon bed of height 0.03m with 0.384 voidage. The pressure drop across the fluidized-bed was calculated to be 1.848 N/m2. The COD and BOD5 concentration reduction efficiencies were monitored .The results obtained indicate that as HRT increases, the concentration of COD and BOD5 initially at 7137.67 COD mg/l and 2177 BOD5 mg/l decreased to final concentration of 1845.92 mg COD/l and 154.17 mg BOD5/l respectively at10h. The COD and BOD5 reduction efficiencies were observed to be 74.1% and 92.9% at the 10h HRT. The experimental data obtained for COD reduction in this work was used for determination of kinetic parameters from modified mixed-flow equation based on Michaelis-Menten’s kinetics and the correlation coefficient was  0.944 .The maximum substrate utilization rate, rmax and the Michaelis-Menten’s constant, KM, were determined to be 301.5 mg COD/l. h and 1345 mg COD/l respectively. Correction factor (F) of 1.1 when applied to the data will fitted simple mixed flow Michaelis Menten kinetic model well. The deviation from typical Michaelis Menten kinetic model can be attributed to acclimatization time required for effective digestion, flow dynamics in the reactor and existence of multi-organism media which would have promoted other side reactions. Organisms identified from the anaerobic digester include clostridium spp, peptococcus anaerobus, bfidobacteriums spp, desulphoribrio spp, corynebacterium spp, lacto. Keywords: Anaerobic decomposition; Brewery wastewater; Fluidized-bed reactor; Modified Michaelis-Menten’s kinetics

Potency and Implications of Bacteria Growth, H2S and FeS Production in Microbially Induced Corrosion of Oil Pipelines using Selected Biocides

In this study, the potency and implications of bacteria growth, H2S and FeS production in microbially induced corrosion of oil pipelines were done using 5 biocides. Hydrogenase test was carried out and used to detect the presence of micro-organism that causes corrosion in the pipeline samples. The biocides were then compared to ascertain how efficiently they can curb the proliferation of bacteria in experimental set-up filled with a bacterial cultured agar using anaerobic medium. Generally, it was found that there use led to reduction in bacteria growth, less and less of iron sulfide and hydrogen sulfide as the concentration and duration of experimentation increases. Specifically, it was found that while cow urine and biaguanide terminate their iron sulfide production after 5th and 6th week, respectively, others continue throughout the 13 week experimentation period. Similarly, cow urine and biaguanide terminate their hydrogen sulfide production after 3rd and 5th, respectively, others continued throughout. Altogether, 10 exponential trendline equations were formulated for iron sulfide and hydrogen sulfide production. R2 goodness-of-fit statistical technique was employed in the analysis for future predictions from the model and the values obtained in each case is close to 1 which indicates a good measure that future outcomes are very likely to be predicted well by the developed equations. Keywords: Biocides, Microbial Corrosion, Hydrogen Sulphide, Iron Sulphide, Bacteria Growt

Rainfall intensity-duration-frequency analysis for Southeastern Nigeria

Inadequate hydrologic data and the need for proper planning of water resources development have forced engineers to analyze available data more critically.  This is particularly so in developing countries.  The Intensity-Duration-Frequency (IDF) relationship is one of the most commonly used basis for water resources planning and development.  This study analyzed rainfall data and characteristics for locations in seven states of Southeastern Nigeria.  IDF curves were developed for these locations using two methods (Graphical and Statistical) and the results were compared.  The locations are Onitsha in Anambra State, Enugu in Enugu State, Abakiliki in Ebonyi State, Umuahia in Abia State, Owerri in Imo State, Port Harcourt in Rivers State and Uyo in Akwa Ibom State.  Break-point, short duration, rainfall data are not generally available in the historical records at the locations.  Generalized accumulated rainfall patterns developed by USDA Soil Conservation Service were matched with rainfall data for the locations of study, and the advanced pattern had the best fit with the observed characteristics and was used to break down recorded daily totals into shorter duration rainfall data.  The method of annual maxima series was used to select data sets for the rainfall analysis.  In the statistical method, the Type I extreme-value distribution (Gumbel) was applied to the annual maximum series for each of the seven stations to estimate the relevant parameters of the IDF model.  The non-parametric Kolmogorov-Smirnov test and the χ2 test were used to confirm the appropriateness of the fitted distributions for the locations.  IDF data developed from the graphical and statistical methods applied were very close for the lower return periods of two to ten years, but differed for higher return periods of 50 to 100 years.  However, the difference is not significant at 5% level.  The data developed by either of the methods will facilitate planning and design for water resources development in Southeastern Nigeria.Keywords: rainfall, intensity, water resources, hydrologic data Citation: Okonkwo G. I., and C. C. Mbajiorgu.  Rainfall intensity-duration-frequency analysis for Southeastern Nigeria.  Agric Eng Int: CIGR Journal, 2010, 12(1): 22-30

Effects of moisture barrier and initial moisture content on the storage life of some horticultural produce in evaporative coolant

Shelf-life of five horticultural produce were studied. These include three leafy vegetables: Telfairia occidentalis, Celosia argentea and Amaranthus cruentus and two fruit vegetables: Lycopersicum esculentum and Abelmuschus esculentus. The layout plan of the experiment was a 3x2 factorial in a completely randomized design and each treatment replicated three times. The two factors examined were moisture barrier at three levels namely: thick lining, thin lining and non-lining. The other factor included initial moisture content of the produce, namely, turgid and partially wilted. Partial wilting of the produce was achieved by exposing freshly harvested materials at ambient temperature to dry for 45 min. During this period, about 20% of the moisture content was lost. Eighteen (18) vegetable baskets which work on the principle of evaporative cooling system were used. Each type of produce was stored at a time inside the vegetable basket. Some quantity of each produce were kept on the laboratory benches to serve as controls. Data recorded includes length of storage of produce, severity of disease infection, visual quality, disease incidence, ambient temperature and relative humidity of the storage baskets. The result indicates that there was a significantly higher relative humidity (P< 0.05) in the lined baskets than in the non-lined baskets. Consequently, the shelf-life of produce in lined basket was prolonged. Turgid produce had better quality retention and stored much longer than partially wilted produce. Generally, the evaporative coolant baskets provided an average temperature of 3°C lower than the ambient condition. The shelf-life of leaf vegetables T. occidentalis, C. argentea and A. cruentus was extended appreciably for 78 days compared to the controls.Keywords: Evaporative coolant, moisture barrier, shelf-life of horticultural produce

Time-Scale Domain Characterization of Time-Varying Ultrawideband Infostation Channel

The time-scale domain geometrical-based method for the characterization of the time varying ultrawideband (UWB) channel typical of an infostation channel is presented. Compared to methods that use Doppler shift as a measure of time-variation in the channel this model provides a more reliable measure of frequency dispersion caused by terminal mobility in the UWB infostation channel. Particularly, it offers carrier frequency independent method of computing wideband channel responses and parameters which are important for ultrawideband systems. Results show that the frequency dispersion of the channel depends on the frequency and not on the choice of bandwidth. And time dispersion depends on bandwidth and not on the frequency. It is also shown that for time-varying UWB, frame length defined over the coherence time obtained with reference to the carrier frequency results in an error margin which can be reduced by using the coherence time defined with respect to the maximum frequency in a given frequency band. And the estimation of the frequency offset using the time-scale domain (wideband) model presented here (especially in the case of multiband UWB frequency synchronization) is more accurate than using frequency offset estimate obtained from narrowband models

Performing arts and change management in syncretized African performances: a study of “Odiiche Dance”

African performances and tradition form important parts of literature in Africa. In fact, even in this 21st century, which is characterized by audio and digital recordings, the bulk of African performances are still not recorded. African performance, as generally known, is dependent on the performer(s) and audience. The audience, until recently, played an active role in traditional African performances. This was at a time when the performer(s) and the audience held the same belief and cultural system. In whichever way the performance manifested itself; in dance, music, drama, oral poetry recitals or folktales, the performers and the audience mostly merged as one and saw the performance as a communal activity and, therefore, did all there was to ensure its success. But recent developments, beginning with Euro-Christian advent, have served to distraught a once active audience into a modern passive one. The advent of the foreigners who introduced beliefs and cultural systems new to the African, has served to disrupt the African performance which had always been the main form of entertainment, education and moral edification. Sad to say, as a result of this, African performances in its original rendition, have now metamorphosed into western classical performances. This trend cannot be reversed easily; however, it can be adapted to boost active participation in African performances. This paper examines those beliefs and cultural systems which have shattered the very foundations of African performances. The researchers therefore evaluated and analyzed these challenges through interview, case study and content analysis approaches of the qualitative research method. Most importantly, the paper focuses on the blending of both the European and African cultures for a positive change. It concludes that despite the changing nature of the performances, African performances still retains its taste and her audiences are still alive, hence, with the case study of the “Odiiche Dance”. It is also the recommendation of the researchers that African-centered courses be taught throughout the educational levels in such a way as to refute the thinking that only the uncivilized persons participate in African traditional performances