986 research outputs found
COMPLEMENTARY GENERALIZED TRANSMUTED POISSON LOMAX DISTRIBUTION WITH ITS DERIVED PROPERTIES AND APPLICATION
There has been a renewed interest in developing more flexible statistical distributions in recent decades. A major milestone in the methods for generating statistical distributions is undoubtedly the system of differential equation approach. There is a recent renewed interest in generating skewed distributions. In this research, a new four parameter lifetime distribution which extends the Lomax distribution is introduced by compounding the Lomax distribution with the complementary generalized transmuted Poisson family of distributions. The probability density function and cumulative distribution function as well as some basic statistical properties of the new distribution, such as moments, reliability function, hazard function, quantile function, residual life function, entropy and the order statistics were derived. Some plots of the distribution shows that it is a positively skewed distribution. The maximum likelihood estimation method is used to estimate the parameters of the new distribution. A simulation study to assess the performance of the parameters of the newly developed distribution was provided with an application to real life data to assess its potentiality. The result shows that the proposed distribution provides better fit than some generalizations of the Lomax . Keywords: Lifetime distribution, maximum likelihood estimation, Lomax distribution, hazard   function, order statistics
World Capitalist System and Globalization: Reconsiderations for Achieving Sustainable Development in Nigeria
Capitalism with its accompanied liberal ideology has been very successful in expanding its tentacles to and overthrowing other social and economic systems in several parts of the world. The resulting consequence of this historical process is that of globalization which is characterized by increasing homogeneity and interdependence of the various countries of the world on one another. While globalization has been recurrent and become a focus for scholarly discourse, Nigeria right from the time of her independence has remained at a disadvantage position in terms of economic, political, technological and cultural development. Historical events showed that the âsupposed giant of Africaâ as a peripheral country, has been dancing to the music of the more developed nations, thus experiencing disguised dependency even as an independent republic. However, if the country is serious about achieving its sustainable development goals, it must learn to dictate its own tune and look inwards for the restructuration of its social, economic and political systems in line with her area of strength, as well as addressing her weaknesses. Thus, this paper attempts to describe the current world capitalist system in the light of World-Systems Theory, discuss globalization and then examine key areas Nigeria must look into for the emancipation of its people from the shackles of underdevelopment and dependency. In conclusion, it is recommended that true Federalism and Nationalism should be the watchword and practice of both political leaders and Nigerian citizens in order to achieve grassroots development and national progress. Keywords: World Capitalist System, Globalization, Sustainable Development, Federalism, Nationalis
Nigerian Science Teachersâ Perceptions of Effective Science Teaching and their Classroom Teaching Practices in Junior Secondary Schools in Lagos State, Nigeria
This study explores science teachersâ perceptions of effective science teaching and their classroom teaching practices. The study was carried out from a population of junior secondary schools in Lagos State, Nigeria. A purposive sample of 78 basic science teachers selected from 61 junior secondary schools from three Education Districts of the state was used for the study. A research instrument tagged effective teaching characteristics questionnaire (ETCQ) was used to elicit information from the teachers. The questionnaire has a test-retest reliability coefficient of 0.83. Data collected were analyzed using frequency counts and simple percentage. The findings indicated that the science curriculum used in schools was overloaded with content to be memorized by learners for examination purposes and that most science teachers engaged students mostly in explanation and demonstration, whole class discussion and note copying. The findings further showed that effective science teaching is characterized by student-centered activities associated with students being attentive, reading notes, doing homework, asking and responding to questions and engaging in regular hands-on practical inquiry-based activity and carrying out their own observations among others. Finally, recommendations for improving science teaching for junior secondary schools in Lagos State were proffered. Keywords: Effective teaching, teacher-centered, perceptions, practical work, teaching resource
Time series model building with Fourier autoregressive model
This paper presents time series model building using Fourier autoregressive models. This model is capable of modelling and forecasting time series data that exhibit periodic and seasonal movements. From the implementation of the model, FAR(1), FAR(2) and FAR(3) models were chosen based on the periodic autocorrelation function (PeACF) and periodic partial autocorrelation function. The coefficients of the tentative modelwere estimated using a discrete Fourier transform estimation method. The FAR(1) model was chosen as the optimal model based on the smallest value of periodic Akaike and Bayesian information criteria, and the residuals of the fitted models were diagnosed to be white noise using the periodic residual autocorrelation function. The out-sample forecasts were obtained for the Nigerian monthly rainfall series from January 2018 to December 2019 using the FAR(1) and SARIMA(1,1,1)x(1,1,1)ââ models. The results exhibited a continuous periodic and seasonal movement but the periodic movement in the forecasted rainfall series was better with FAR(1) because its values showed a close reflection of the original series. The values of the forecast evaluation for both models showed that the forecast was consistent and accurate but the FAR(1) model forecast was more accurate since its forecast evaluation values were relatively lower. Hence, the Fourier autoregressive model is adequate and suitable for modelling and forecasting periodicity and seasonality in Nigerian rainfall time series data and any part of the world with rainfall series that are mostly characterised with periodic variation
Phytochemical studies, in vitro antioxidant and antiproliferative of the stem bark of Boswellia dalzielii hutch
This work aims to evaluate the total phenolic and flavonoid contents, and antioxidant and Antiproliferative activities of the stem bark of Boswellia dalzielii. Hundred gram (100 g) of methanolic extract was re-dissolved in 70% methanol and partitioned exhaustively with different solvent hexane and ethyl acetate in a separating funnel; and this method gave three fractions, hexane fraction, ethyl acetate fraction and aqueous extract. The ethyl acetate fraction was subjected to Accelerated Gradient Chromatographic due to its higher activity over the hexane fraction and four sub-fractions were obtained. Standard methods were used to determine flavonoid and phenolic contents of the methanolic, aqueous, ethyl acetate and hexane fractions and their sub-fractions. Standard methods were used to determine flavonoid and phenolic contents of the methanolic, aqueous, ethyl acetate and hexane extracts and their sub-fractions. The antioxidant property of the extracts was determined using DPPH radical scavenging and FRAP assay. Growth inhibitory activity was carried out on the crude extracts and sub-fractions using Sorghum bicolor seeds. The phenolic content was found to be highest in sub-fraction C (481.20 ± 10.13 mg GAE/g) and flavonoid contents were found to be highest in methanolic extract (142.17 ± 4.82 mg RE/g). Boswellia dalzielii stem bark exhibited antioxidant capacity; and the highest antioxidant activities were recorded from aqueous extract with the IC50 1.58 and methanol extract IC50 1.99 using DPPH. FRAP assay exhibited antioxidant capacity with EC50 1.00 for aqueous extract and sub-fraction D EC50 1.25. The antiproliferative, sub-fractions C and D at 125 ”g/ml gave the highest percentage of inhibition (90%) followed by sub-fraction B (50%) at 250 ”g/ml. These results further showed that the stem bark of Boswellia dalzielii has antioxidant activities and antiproliferative activity on the seeds of Sorghum bicolor; and therefore possess likely an anticancer component which needs further anticancer screening
Ethnobotanical and in vitro cytotoxicity studies of Moringa oleifera, Andrographis paniculata and Asystasia vogeliana extracts
Ethnobotanical and in vitro cytotoxicity studies were carried out on three different multi- purpose medicinal plants; Moringa oleifera (Lam) (Moringaceae), Andrographis paniculata (Burm. f) and Asystasia vogeliana (Benth) (Acanthaceae). The ethnobotanical information was collected by one to one interview and discussions using semi-structured questionnaires with indigenous people from selected locations in Nigeria. Plant samples collected were identified and authenticated in Forestry Research Institute of Nigeria (FRIN), Ibadan, Oyo State. Each of these three plant samples was extracted in 95% ethanol using a soxhlet extraction apparatus and concentrated to dryness at 45 °C. M. oleifera showed the highest incidence of occurrence (17.5%), fidelity level (74.9%) and multi-purpose usage. The ethnobotanical study revealed the medicinal relevance of the three plants in the treatment of myriads of diseases and ailments including malaria, fever, high blood pressure, cancer, diabetes among others in local herbal medicine. The in vitro cytotoxicity activities of ethanol extracts of the three plant species were screened in two cancer cell lines (BGC-823 and HeLa cells) using the sulphorhodamine B (SRB) assay. Cytotoxicity assay on the two cell lines BGC-823 and HeLa cells revealed that only the ethanolic extract of A. paniculata exhibited some level (moderate) cytotoxicity activity with IC50 values of 24.7 and 23.1 Όg/ml respectively. M. oleifera and A. vogeliana did not show any significant activity on the cell lines. The study highlights the importance of ethnobotanical information in finding cost effective, potent and safe herbs for people and screening of the plant species for their activities against cancer cell lines. Further studies on the isolation and characterization of bioactive compounds responsible for cytotoxic effects of A. paniculata is recommended
Nasal Carriage of Staphylococcus aureus and Associated Risk Factors among Students in a Nigerian University
Nasal carriage of Staphylococcus aureus has been associated with subsequent infection and transmission within the hospital and
community settings. This study was carried out to evaluate the carriage rates of S. aureus in a University student population and
describe risk factors associated with the carriage. Two-hundred and seventy-seven nasal samples were obtained from healthy volunteer
students and screened for S. aureus by standard microbiological techniques. Antibiotic susceptibility testing was conducted on
the bacterial isolates by the disk diffusion technique. A questionnaire was conducted with each student to acquire demographic and
risk factor information. One hundred and fifty-seven (56.7%) isolates were identified as S. aureus. Antibiotic resistance was highest
for cloxacillin (91%), ceftazidime (71%), cotrimoxazole (23%), erythromycin (20%) and oxacillin (16%). Risk factors such as hospitalization
in the past 12 months, recent skin infection and participation in sports were significantly associated with carrier status.
High resistance to certain antibiotics observed in this study shows that nasal colonization could serve as a reservoir of antibiotic
resistant strains within the community
Effect of Common Salt on the Engineering Properties of Expansive Soil
This paper investigated the effect of common salt on some geotechnical properties of expansive soil for highway pavement (subgrade) works. In this study, engineering properties including; Natural water content, Atterberg limits, specific gravity, compaction, free swell index, unconfined compressive strength, soaked and unsoaked California bearing ratio were determined in the laboratory and their behavior on stabilizing with various percentages of sodium chloride (0, 0.5, 1.0, 1.5. 2.0 and 2.5) investigated. From the study, plastic limit, liquid limit, plasticity index, linear shrinkage, specific gravity, free swell index and optimum water content values of the stabilized soil reduced, while the maximum dry density, California bearing ratio and unconfined compressive strength values increased. The highest reduction percentages of 60.42 % (131 to 51.85 %), 42.86 % (50.00 to 28.57 %), 71.26 % (81.00 to 23.28 %), 66.64 % (15.11 to 5.04 %), 83.43 % (115.00 to 19.05 %), and 28.57 % (28.00 to 20.00 %) in liquid limit, plastic limit, plasticity index, linear shrinkage, free swell index and optimum water content respectively; and maximum percentage increase of 11.38 % (1.67 to 1.86 g/m3 ,on maximum dry density), 31.78 % (29.20 to 38.48 %, on unsoaked CBR), 257.67 % (4.3 to 15.38 %, on soaked CBR), and 26.98 % ( 67.86 to 86.17 kN/m2 on unconfined compressive strength) were obtained on treatment of the soil with 1.5 % common salt by weight. Treatment of the soil with common salt has thus reduced its swelling potential and increased the strength
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