317 research outputs found

    Karyotype of a Nigerian population of Hyperopisus bebe (Osteoglossiformes: Mormyridae) revealed another evolutionary lineage in the monospecific genus: Hyperopisus

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    This study provides data on the gross chromosome morphology, including centromeric and silver nitrate banding of a Nigerian population of Hyperopisus bebe, sampled from Asejire Reservoir, Osun River basin. The chromosomes of the fish samples were extracted using the Giemsa staining technique, and the centromeric and silver nitrate bandings were analyzed based on standard cytogenetic methods. The H. bebe population had a chromosome number of 2n = 40 and a karyotype formula of 2n = 40 (24m+6sm+10st/a), FN = 70. C-bands were restricted to the centromeric regions, suggesting that Robertsonian events are the major mechanism in the karyotype evolution in the population. Currently, H. bebe represents the only species in the genus Hyperopisus. The karyomorph data from this study suggest that the fish sample belongs to another species. However, other systematic approaches are needed to establish its taxonomic status

    First Report on the Karyotype of the Freshwater Weakly Electric Fish; Marcusenius brucii (Osteoglossiformes: Mormyridae) in Asejire Reservoir, Osun River Basin, Nigeria

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    The weakly electric fishes of the family Mormyridae are one of the dominant fish groups in Africa; they are represented in all the major freshwater bodies in the tropical regions of the continent, except the Southernmost Cape Provinces, the Sahara and the Northernmost Maghreb. The Mormyridae boasts 225 species in 22 genera, making it the most speciose Osteoglossiformes family. Such great diversity requires many systematics approaches for good comprehension; to this end, cytogenetics provides valuable data for a better definition of this diversity. However, cytogenetics data on mormyrids are still scarce, thus limiting its usefulness in the biodiversity study of the group. In this study, the chromosome composition of a mormyrid species, Marcusenius brucii, was investigated to reveal its chromosome number and standard karyotype for the first time; to enhance the understanding of the karyotype organization of the group. The fish was sourced from a local fisherman in Asejire Reservoir, Osun River Basin, Nigeria. Metaphase chromosomes were prepared from the fish kidney after in vivo injection with 0.05% colchicine solution. Slide preparation and karyotyping followed conventional cytogenetics techniques. The study showed that M. brucii karyotype consists of a diploid number of 2n = 50 dominated by two-armed chromosomes. While the chromosome number is in harmony with the general chromosome number in the order Osteoglossiformes and the hypothetical diploid number for the family Mormyridae, it differed mainly in its possession of bi-armed elements. The phylogeny of Marcusenius is yet to be resolved; this, coupled with the limited karyotyped individuals in the genus, makes the karyotype evolution of the genus difficult to infer. This scenario will improve as the cytogenetics knowledge of the genus increases. Keywords: Cytogenetics, chromosomes elephantfishes, karyotype, mormyrids, Osteoglossiformes DOI: 10.7176/JNSR/13-18-03 Publication date:October 31st 202

    Karyotype of the Mormyrid Baby Whale Fish (Osteoglossiformes: Mormyridae): Brienomyrus Brachyistius in Oluwa River, Nigeria

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    The mormyrid fishes of the order Osteoglossiformes are abundant in the freshwaters of tropical Africa; the enormous species diversity of the group requires many systematics tools to comprehend this diversity better. Cytogenetics data can complement other systematics procedures to accomplish the above-stated objective, but information on many mormyrids' karyotypes is unavailable. In this study, Brienomyrus brachyistius from the Oluwa River was studied to enhance the understanding of the karyotype organization in the Mormyridae. Metaphase chromosomes were processed from the fish kidney following a conventional cytogenetic procedure; the fish was subjected to an intra-peritoneal colchicine injection at the rate of 1ml per 100g of fish mass. Hypotonic treatment was in 0.56% KCl solution, and cells fixation and washes were in 3: 1 methanol: acetic acid. The slides were stained with Giemsa solution, while the constitutive heterochromatin was revealed from the previous Giemsa stained slide using the C-banding sequential method. Capturing of metaphase images was done with an Olympus BX50 microscope. The karyotype of 2n = 50 (50sta) obtained in the species was the first mormyrid karyotype composed of 2n = 50 acrocentrics, supporting the proposed ancestral karyotype for the Mormyridae. Keywords: Cytogenetics, chromosomes, Osteoglossiformes, karyotype, Mormyrids, elephantfish DOI: 10.7176/JBAH/12-20-04 Publication date:October 31st 2022

    Incidence of bovine cysticercosis in kano state, northwestern, Nigeria

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    The incidence of infection due to Cysticercus bovis in Kano abattoir located in Fagge local government area (LGA) of Kano state, Nigeria was studied. Out of the 11,804 cattle which were examined, 315 (2.67%) were found to be infected. The tongue, cardiac and masseter muscles were the main predilection sites of the cysts. The relative occurrence of the cysts in the organs of infected catteles showed tongue (76%), heart (66%) and masseter (63%) had the highest rate of infestation. There was no significant difference (p>0.05) in the distribution of the cysticerci in the organs of cattle slaughtered at the abattoir. The results also show 205 (0.37%) and 304 (0.55%) head and heart condemnations respectively. This information is considered useful for government authorities to direct control strategies as well as for farmers to take measures tailored to local situations

    Effects of Bioavailability and Accumulation of Single Metal and Mixture Metal on Toxicity to the Mite, Oppia nitens

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    Canada has some of the largest metal deposits in the world and the Canadian mining industry is one the largest employers of labour in Canada. Consequently, mining and smelting operations in Canada are one of the sources of metal level increase in the environment. Metals pollute the terrestrial environment because of fall-out from the mining industry. Soils are major sinks for metals in the terrestrial environment. It is therefore important that metal risk assessment should clearly reflect the metal contamination in the soils. The main objectives of this thesis were to generate more realistic metal toxicity data using a native Canadian invertebrate species that will help improve metal risk assessment in Canada. Firstly, toxicity of common metals (Cu, Pb, Zn, Co, Ni) found in contaminated sites in Canada was assessed on an oribatid mite, Oppia nitens which is abundant in Canadian soils. The metal toxicities were assessed as singles and as mixtures in five different soils. The metal mixture ratios were fixed such that it reflected ratios of metals found in contaminated sites. The patterns of sensitivity of the mite to metals by soils differed between single metals and metal mixtures. Nickel, which had not been tested with Oppia nitens before, was found to be the most toxic metal to the mite and zinc was less toxic. Concentration addition was protective of 53% of metal mixture toxicity due to antagonistic and concentration addition. Bioavailable metals existed as metals bound to fulvic acid. After determining the toxicity of the metals in the five soils, the multigenerational effect of one of the metals on soil mites was investigated in the most sensitive soil to single metal contamination. Continuous and pulse zinc exposure effect on O. nitens populations was assessed in three generations of the mites. Using critical-effect levels (EC50s), pulse exposed mites seemed to be tolerant and the continuous exposed mites were sensitive. However, the instantaneous population growth rate showed that both pulse and continuous exposures were more sensitive than their parents. The major finding from this study was that persistence of metals in soils can cause multigenerational adverse effects on continuously exposed mites in the soil. The last chapter of this thesis investigated the direct effect of soil habitat quality as a site-specific feature on organisms and how it influenced their response to metal contamination. For this test, forty-seven (47) soils were ranked according to their habitat qualities from one to three (high to low), using standard soil invertebrate species (Folsomia candida, Enchytraeus crypticus) fitness and plant (Elymus lanceolatus) productivity as metrics to choose habitat qualities. From the ranked 47 soils, eighteen (18) soils comprising six soils making each habitat quality was chosen in a duplicated experiment. The soils were spiked with increasing concentrations of Zn and the Zn toxicokinetics, toxicodynamics, survival and reproduction of mites were assessed. The mites in the soils of high habitat quality were less stressed than mites in the low habitat quality soils despite being exposed to the same amount of bioavailable metals. The key findings from this study were that soil habitat quality has a direct influence on how its inhabitants cope with metal stress. Therefore, habitat qualities of soils can be considered as a site-specific feature in remediation of contaminated sites

    THE CONSTRUCT, INTRODUCTION AND SITUATE OF RUDIMENTARY NUMBER SKILLS FOR CHILDREN IN NUMERACY LEARNING OUTCOMES

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    The competence and positive disposition development toward mathematic subject has been observed an uphill task to learners across educational endeavors despite its need in life at home, paid work, participation in community and civic life. The Nigerian Education Policy (2013) made numeracy an important aspect of the specific objectives of primary education in Nigeria. However, the teaching-learning processes lithely attend to specification(s) of utilities. In Nigeria, most schools lack instructional materials; the available were mainly ready-made - majorly imported. Information and communication technology has greatly improved teaching and learning yet, observations revealed domination of foreign tongued instructional materials – uneconomical, alien, distractive and inadequate. This study constructs and investigates the effect of a locally produced, customized numeracy package, the Rudimentary Number Skills for Children (RuNS-K) on academic achievement of pupils in computer mediated environment with a view to improve pupils’ performance in numeracy. Pre-test, post-test, quasi experimental research design was adopted. The population consist lower primary school pupils in southwest Nigeria. Multi stage sampling technique was employed to select study sample. One senatorial district, one of the five major cities in the district, three of the eighty-four public primary schools having functional computer laboratories were purposively sampled. An intact class in each school was randomly assigned into two experimental (ICT-integrated Learning Cycle and ICT-integrated Learners-self-controlled) and a comparison groups. Study instruments include the Rudimentary Number Skill for Children (RuNS-K) and the Test of Numeracy Achievement (TNA). The study found localized, customized packages needful for numeracy improvement. It also found significant improvement in numeracy performance in learners in ICT-integrated Learners-self-controlled (ICT- LSC) situation. The study further revealed customized ICT- LSC learning strategy as best influence for retention in pupils. It concludes that, interventions with customized, ICT-integrated learners-self-controlled situation improve learners’ cognition both in performance and retention. Study recommends localized, improvised educational materials development and usage as aid to improving teaching-learning process and the entire education system in Nigeria

    Photovoltaic Generating System Parameter Sizing for Building

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    Small to medium sized battery storage required to address the intermittency challenge of the energy of solar radiation could be achieved by appropriate sizing of the photovoltaic system parameters like photovoltaic module (PVM) number and battery capacity. This paper presents the results of evaluation of the optimum parameter values in sizing of stand-alone photovoltaic (PV) system that satisfies building energy demand, with almost zero Loss of Power Supply Probability (LPSP). A time step simulation of system performance based on energy balance for various combinations of PV numbers and battery capacities was employed. (Three seasons of operation were considered; rainy, hot and hot/dry). The rainy season result indicating high storage capacity requirement of about (2500-Ah), is of highest cost compared to other seasons. Stand-alone photovoltaic system size that will assuage the intermittency challenge; mitigate peak demand costs and provide near zero LPSP was determined. Keywords: loss of power supply probability, photovoltaic, energy demand, parameter sizing, stand-alon

    Effective Teaching Practice Supervison: A Predictor of Teacher Trainees' Performance in Pedagogy

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    The quality of teachers prepared for basic education in Africa and othercontinents of the world is a consequence of the knowledge of contentacquired and the pedagogy. Effective teaching practice supervision coulddetermine the level of teacher trainees� performance in the art of teaching. The study investigated the differences in performance of teacher trainees who embarked on continuous Teaching Practice and Supervision � TP & S (of twelve weeks) and those of non-continuous teaching practice and supervision ï¿½ TP & S (of six weeks in two installments). It equally examined whether there was a relationship or not in the performance of teacher trainees when they are team supervised and when they are not teamed supervised in pedagogy. Five hundred (500) teacher trainees were randomly selected assamples from two (2) colleges of education owned by Lagos StateGovernment of Nigeria. They are Adeniran Ogunsanya College of Education (AOCOED), Ijanikin and Michael Otedola College of Primary Education (MOCPED), Noforija-Epe. Their final assessment scores at the end of 2008/2009 teaching practice exercise were utilized. Using independent t-test statistic, it was found that those who embarked on continuous TP & S were able to perform significantly better than those who embarked on noncontinuous TP & S. However, using Pearson Moment Correlation Analysis (r), there was a significant relationship in the performance of teacher trainees when they were team supervised and when they were not team supervised at all. It was suggested among others that if teacher trainees should go on continuous TP & S, they would be more skilled and thus develop competence and dexterity in pedagogy since practice makes perfection. Team supervision of pedagogy was also suggested so as to curb subjectivity and biases, even as teachers are prepared for basic education.&nbsp

    Residential Indoor Radon Assessment in the Vicinity of some Dumpsites in Lagos, Nigeria

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    Dumpsites in Nigeria are generally open and significantly elevate the pollution and contamination level of the total environment.  Indoor radon was measured with CR-39 detectors in some buildings in the vicinity of dumpsites in Lagos, Nigeria. Eight (8) dumpsites (4 dormant and 4 active dumpsites) were chosen for this study. Detectors were exposed in 50 houses randomly selected within 0 and 100m away from the dumpsites. The detectors were exposed for 3 months. They were then retrieved and etched in a 6M NaOH solution in a water-bath at a temperature of 90o C for 3 hours. Tracks were counted using a semi-automatic system with a DCE camera mounted on a microscope and connected to a PC. Radon concentration ranged from 24.00±4.86 to 656.00±131.20 Bqm-3 in the active dumpsites.Mean concentrations were 120.3±24.0, 257±51.4, 179.8±33.6, and 131.5±19.4, respectively in Oke-Odo, MRF, Olusosun, and Solus-3. In the dormant sites, concentration ranged from 16±3.2 to 931±186.3 Bqm-3 having means of 194.17±38.80, 206.75±41.33, 223.25±44.69, and 334±66.85Bqm-3 , respectively in Oke-Afa, Solus-1, Solus-2, and Solus-4. The annual effective dose and cancer risk in the active and dormant dumpsites were (3.60 mSv, 8.97 per million person-yearly) and (4.53 mSv, 12.47 per million person-yearly), respectively. This study revealed some high value of radon concentrations in some houses close to the dormant dumpsites than in the active dumpsites. This is unsafe and can cause severe health issues in the long term. Keywords: Radon, dumpsites, Olusosun, CR-39, buildings, Lagos state, SOLU

    Conversational Strategies in Ola Rotimi’s The gods Are Not to Blame

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    This paper examined the conversational features used by characters through talk in Ola Rotimi’s The gods Are not to Blame. Several studies have been carried out on Ola Rotimi’s works but this study was motivated by the scanty scholarly studies on the conversational strategies used in the text. In order to bring out the features of conversation in the text, the text was critically read, and salient conversational features were identified. The features were interpreted according to the messages they expressed in the text. The findings revealed that conversational features such as monologue, turn taking, turn allocation, speech overlap, error and repair mechanism, adjacency pairs, and insertion sequence were used to generate different effects in the text. The study concludes that the conversational features employed by the author create orderliness and regulate participants’ talk in the interaction towards actualising the thematic goals of the text. Thus, the study indicates that conversation analysis gives a deeper and better understanding of human utterances as portrayed through the characters in the text, thereby increasing the readers understanding of the text
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