THE CONCURRENT VALIDITY OF MOCK EXAMINATIONS CONDUCTED BY A NIGERIAN PRIVATE SECONDARY SCHOOL

Achieving test validity is an essential concern in test development, particularly when a test is used for an important purpose. Conducting mock examinations for students in the terminal classes of Senior Secondary Schools (SS3) is fast becoming the norm in Nigeria as various school managements are persuaded that such examinations do not only ascertain the level of readiness of their student for the summative and matriculation examination conducted by independent examination bodies, but also enhances their capacity for the impending external examinations. It is against the backdrop of the perceived significance of mock examinations this study sought to ascertain the concurrent validity of the Mock examinations, conducted by a Nigerian private secondary school, with Nigeria’s Joint Admission Matriculation Board Unified Tertiary Matriculation Examination [JAMB-UTME]. The ex-post facto research design was used. The data collected was subjected to Pearson product moment correlation coefficient. The results showed that that the Mock examination developed by the Nigerian Private Secondary School had a concurrent validity index of 0.50 (@ p<0.01 and N=150) with the more standardized JAMB UTME in the 2012/13 session and a concurrent validity index of 0.59 (@ p<0.01 and N=150) during the 2013/14 session.Recommendations to enhance the quality of Mock examination were made

Long term effects of formaldehyde preservation on subsequent bone maceration procedures: a comparative study between cold and hot water maceration

This study was conducted to compare the effectiveness of cold and hot water maceration techniques for the development of bone specimens from cadavers. Three already dissected bodies of both sexes (two males and a female) obtained from the Department of Anatomy, Bowen University, Iwo, Osun State, Nigeria were used. The male bodies were labelled as A and B and the female as C. Before maceration, the heights of the bodies were taken to be 165 cm, 170 cm and 160 cm for A, B and C respectively. The bodies were preserved in formalin for 4 years before being used. Hot water maceration involves cooking bones in water. Bodies A and C were used in this method. While cold water maceration is simply by soaking the body in water until all the remaining flesh was removed. Hot water maceration showed changes in color of the bones, shrinkage of the bones, oily substances were seen on the surface of the chloroform during degreasing and the bones were very soft after bleaching but got harder after drying with sunlight. Cold water maceration on the other hand kept the bones white and maintained their integrity though it required a lot of time. Small bones had their flesh removed quickly in few weeks, while larger and longer bones took months. We conclude that cold water maceration done properly, results in cleaner bones and better morphological outcomes than hot water method though it requires much time.KEYWORDS: Maceration, Formaldehyde, Comparative, Bones, Hot water, Cold wate

Abundances of Nitrates and Coliform with Regards to Water Quality. In Some Parts of lbadan, Southwest, Nigeria.

Water pollution has been reported throughout the world and Nigeria is not an exception. A very wide range of pollutants have been recognized, including Nitrogen species and bacteria. Nitrate (NO.) is the main form of Nitrogen which occurs in water and is becoming increasingly widespread because of agriculture activities, the disposal of sewage and wastes. This study thus focused on the assessment of the water samples in Ibadan, .Southwest, Nigeria based on these two pollutants (NO,) and. Colform) and possibility of natural denitrification in the study area. The surface and groundwater in Ibadan h:w e been polluted by municipal, industrial wastewater, agricultural activities among others. 1 he nitrate and coliform concentrations at thirty sampling points with in Tbadan ranged from 5.89 to 250mg/l and 74-IOOOcfu/ lOOmg/1 respectively. The concentration of nitrate and califom1 exceeded the WHO limit of I Omg/1 and Ocfu/ lOOmg!r'in 93% and 1OQ% of the sampled locations respectively. High nitrate and califom1 ·levels were observed in water from wells from the undeveloped part of the smdv area. The decrease in nitrate concentration viz a viz an increase in both HCO,- and pH along the groundwater flow direction confirmed the possibility of nitrate removal or natural denitrification in the study area

Partial Purification and Kinetic Properties of Polygalacturonase from Solanum macrocarpum L. Fruit

Background and Objective: Polygalacturonase [Poly (1, 4-"-D-galacturonide) glucanohydrolase, E.C 3.2.1.15] is a subclass of pectinase that hydrolyzes the glycosidic linkages between galacturonic acid residues in polygalacturonans. Solanum macrocarpum ripening prompts pectinase production. The objective of this study was to examine the kinetic properties of polygalacturonase from Solanum macrocarpum L. fruit. Methodology: The enzyme was partially purified by ammonium sulphate precipitation and gel filtration. Protein content, polygalacturonase activity and kinetic parameters were determined. Results: The protein content and polygalacturonase activity of the fruit juice extracts were 0.63±0.02 mg mLG1 and 45.96±6.31 U mgG1 protein, respectively. A 1.7 and 108.3 fold increase in enzyme activity was achieved by ammonium sulphate precipitation and gel filtration, respectively. The enzyme had a Vmax of 76.92 unit mgG1 protein and Km of 0.92 mg mLG1. The pH profile of the enzyme showed three activity peaks at 3.0, 5.5 and 7.0. The enzyme was most active at pH 3.0 and showed optimal activity at 30EC. Rapid release of product was observed within the first 20 min of enzyme incubation. The Zn2+, Ca2+, Mn2+, Pb2+, Fe2+, Cu2+ and EDTA exhibited inhibitory effect on polygalacturonase activity whereas Mg2+ had stimulatory effect on the enzyme. Conclusion: It was concluded that the fruit of Solanum macrocarpum is a rich source of polygalacturonase. The enzyme is favourably comparable with that of a fungi source and could be further exploited for commercial production of the enzym

Physicochemical assessment and bacteriological studies of hand-dug wells of major markets in south western, Nigeria

Rapid population in developing nations has imposed stress on groundwater resources, thus the need to assess physicochemical and bacteriological impact of microbes on hand-dug wells along some major markets in Ibadan Southwestern Nigeria. Water samples from hand-dug wells were measured sequentially, and total dissolved solute (TDS), pH, electrical conductivity (EC), salinity, and temperature were measured in situ. Water samples were analyzed at a Microbiology Laboratory. Most probable techniques used for micro-organism analysis were in three stages: presumptive test used for confirmation of Escherichia coli, confirmed test for total viable bacteria count (TVBC), and complete test to reconfirm the presence of coliform. Presumptive test showed high rate of E. coli in most of the hand-dug wells with (37.5 %). Confirmed test revealed Staphylococcus aureus to be 25 %, followed by Proteus vulgaris (14.6 %), Bacillus species (12.5 %), Pseudomonas aeruginosa (8.3 %), and Klebsiella spp. (2.1 %) respectively. Total viable bacteria counts are 500 to 192,000. Physicochemical results (total dissolved solute (TDS), pH, electrical conductivity (EC), salinity, temperature) when compared with WHO (2006) and SON (2007) revealed all the parameters to be within the permissible limits except pH (5.8 to 9.56), and high values of the parameters were caused by organic matter. High E. coli in the study area revealed influence of human and animal fecal that coul

Microanatomical effects of ethanolic extract of Cola nitida on the stomach mucosa of adult wistar rats

The study investigated the microanatomical effects of the extracts of Cola nitida on the stomach mucosa of adult male Wistar rats. Twenty adult male wistar rats were randomly divided into four equal groups of A, B, C and D (n=5). Animals in experimental groups B, C and D were given 600mg/kg body weight of crude extract of Cola nitida each by oral intubation for five, seven and nine consecutive days respectively, while group A (control) received equivalent volume of distilled water. Twenty four hrs after the last administration, the animals were sacrificed; tissues were harvested and fixed in 10% formol saline for histological analysis. The study revealed necrotized surface epithelium, degenerated gastric mucosa, and loss of glandular elements in the stomachs of experimental groups’ vis-à-vis the control group. These observations were days-dependent; as those groups which received the extract for higher number of days were seen to be adversely affected. In conclusion, Cola nitida at 600mg/kg body weight can cause gastric lesion in animals. This lesion may be pronounced if the administration continued for days. Cola nitida should, therefore, be taken with caution to avoid gastric complications.Keyword: Cola nitida, necrotized, degenerated, stomach mucosa, microanatomy, glandular element