Statistical models for biphasic dose-response relationships (hormesis) in toxicological studies

The dose-response phenomenon characterized by low dose stimulation and high dose toxicity has been reawakened after a long period of marginalization. This phenomenon termed hormesis is induced by biological, physical and chemical agents and occurs in all groups of living things including whole plants and animals, microorganisms, cells and tissues. Hormesis has attracted increased interest among toxicologists from diverse disciplines, resulting to emergence of new scientific tools for its study. Statistical models have been developed and used to characterize hormesis dose-response relationships. Some of these models include the classical Brain-Cousens model, the Cedergreen-Ritz-Streibig model and their reparameterizations. Other hormesis models are the bilogistic models, their modifications or extensions and the hormesis models used in allelopathy such as An-Johnson-Lovett model. These models are used to describe either U-shaped or inverted U-shaped dose-response relationships and to compute hormesis quantities. This review explored the applications of these models in toxicological studies with emphasis to their strengths and weaknesses

Crude oil hydrocarbon degradation efficiency of indigenous bacterial strains isolated from contaminated sites in Nigeria

The crude oil degradation potential of bacterial isolates from three contaminated sites in Nigeria were investigated. Seven bacterial isolates namely Pseudomonas aeruginosa strain W15, Pseudomonas aeruginosa strain N3R, Serratia marcescens strain N4, Providencia vermicola strain W8, Serratia marcescens strain W13, Pseudomonas aeruginosa strain W11 and Pseudomonas protegens strain P7 were isolated and identified using molecular methods. Isolates N4, N3 and W13 showed higher % total petroleum hydrocarbon (TPH) degradation of 79.26%, 78.96% and 78.69% respectively than W15, P7, W8 and W11 with % TPH degradation of 68.96%, 62.14%, 59.75% and 59.00% respectively. W13 showed the fastest degradation rate with 78.72% within the first 14 days of incubation; however, after the 14th day, there was no progressive change in % TPH. W11 showed degradation of wider range of hydrocarbon components originally in the crude oil as well as the complete degradation of most intermediates formed. The isolates showed good degradation potentials for bioremediation applications

The Effectiveness of Fiscal Policy on Economic Stabilization in Nigeria

The effectiveness of fiscal policy in Nigeria over the years has been a matter of great controversy. Thus, this study investigated the effectiveness of Nigeria’s fiscal policy on economic stabilization over the periods 1983–2015. The Auto Regressive Distributed Lag Error-correction model (ARDL-ECM) was employed to take care of short-run dynamics. The fiscal policy variables considered in the study include government expenditure, taxes, government borrowing. Economic stabilization was mirrored with GDP and unemployment level. Over all, the results indicate that both government expenditure and government borrowing has a negative significant impact on unemployment. It reveals an increase in unemployment as government expenditure and government borrowing (public debt) increases. In addition, the outcome supports key conclusion that jointly, government expenditure, government borrowing and taxes have significant positive impacts on gross domestic project (GDP). Consequent upon the findings of the study, we recommend that fiscal policy should be designed in such a way that government expenditure resources are spent on projects that enhance the earning capacity of the low income people and goods required mostly by poor households like education and medical facilities. In addition, there should be re-allocation of capital expenditure so as to enhance employment opportunities for unemployed people. Also, fiscal indiscipline on the part of the government should be curbed while a good, transparent and accountable expenditure system should be put in place. Keywords: Economic Stabilization, ARDL, Fiscal Policy, ECM, Economic Growt

Review of core stability exercise versus conventional exercise in the management of chronic low back pain

Exercise has been proven to be effective in the management of chronic low back pain. Over the years, core stability exercise (CSE) has gained popularity however there is lack of consensus on the best exercise treatment. Aims: To review the effectiveness of core stability exercises or conventional exercises in the management of chronic low back pain (CLBP). Methods: This study is a systematic review of randomized clinical trials which examined studies regarding core stability and conventional exercise by using Google scholar, Medline, PEDro and Cochrane from 2010 to 2021. The Methodological quality was evaluated using the PEDro scale. The included studies randomized participants into two different exercise groups. Results: From the 58 potentially relevant trials, a total of 14 trials were included in the current analysis. The data indicated that core stability exercise was better than conventional exercise for short term pain relief. Ten studies included self reported back specific functional status, and compared to conventional exercise, core stability exercise resulted in significant improvement in function. Conclusion: Compared to conventional exercise, core stability exercise is more effective in pain reduction and improved physical function in individuals with CLBP in the short term however, only two trials carried out follow-up assessments post intervention. Keywords: Core stability exercise; conventional exercise; chronic low back pain

Finite Element Analysis of Continuous Plates Using a High-Performance Programming Language (MATLAB)

This paper uses MATLAB, a finite element software program to compare the results of several finite analysis methods for continuous plates and check the degree of correlation with the exact values obtained by Timoshenko (1959) and Cheung (1996). The results showed little or no significant difference between plates in finite elements. Two different finite Numerical techniques are used. The Finite Strip and Exact methods and their results are compared to the results from the MATLAB program. Finite element analysis (FEA) workflow using MATLAB includes generation of meshes, geometry creation, defining physics of load, initial conditions and boundary problems, calculation, and results from visualization. FEA is a very general approach for solving Equations in science and engineering. This work offers solutions to the increasing errors associated with several other numerical methods when solving any equations of plates (сontinuous). It makes it easier to calculate and design larger structures through geometry discretization of plates and plains into more minor elements

Prediction of the Phytochemical Properties of Luffa Cylindrica Seed Oil Using Artificial Neural Network

The research used an artificial neural network (ANN) to examine optimum extraction conditions and phytochemical contents of Luffa cylindrica seed oil. The oil yield was predicted using an artificial neural network. The performance of the ANN and response surface methodology models was compared. The optimum extraction yielded 7.567% oil yield, 185.676 mg/l phenol, and 45.087 mg/l terpineol at 75.57 °C extraction temperature, 5.77 h extraction time, and 10.68 g/mol n-hexane concentration, respectively. These data show that the oil output is poor but has a significant phenol and terpenoid content that may be employed in pharmaceutical sectors. The FT-IR analysis of Luffa cylindrica seed oil revealed a high level of unsaturated hydrocarbons and esters, making the oil appropriate for using in the paint industry and creating cosmetics

Structural and spectroscopic characterisation of a heme peroxidase from sorghum

A cationic class III peroxidase from Sorghum bicolor was purified to homogeneity. The enzyme contains a high-spin heme, as evidenced by UV-visible spectroscopy and EPR. Steady state oxidation of guaiacol was demonstrated and the enzyme was shown to have higher activity in the presence of calcium ions. A Fe(III)/Fe(II) reduction potential of -266 mV vs NHE was determined. Stopped-flow experiments with H2O2 showed formation of a typical peroxidase Compound I species, which converts to Compound II in the presence of calcium. A crystal structure of the enzyme is reported, the first for a sorghum peroxidase. The structure reveals an active site that is analogous to those for other class I heme peroxidase, and a substrate binding site (assigned as arising from binding of indole-3-acetic acid) at the γ-heme edge. Metal binding sites are observed in the structure on the distal (assigned as a Na(+) ion) and proximal (assigned as a Ca(2+)) sides of the heme, which is consistent with the Ca(2+)-dependence of the steady state and pre-steady state kinetics. It is probably the case that the structural integrity (and, thus, the catalytic activity) of the sorghum enzyme is dependent on metal ion incorporation at these positions

Do Capital Market Returns Actually Predict the Standard of Living of A Nation:Evidence from Nigeria

The study tried to resolve the disagreement in many quarters that the returns of the capital market do not predict or relate to the standard of living of a reporting nation. The position of the researchers in this study was taken by using Nigeria Stock Exchange data and world bank website from 1985 to 2021 and analyzed with Error Correction Mechanism, among others. The result of the cointegration test showed that long run relationship exists between the dependent variable-standard of living proxied by Per capita Gross Domestic Product and independent variables, All-Share Index, Value of Transactions and Volume of Transactions. Further analyses revealed that All Share Index significantly relate to standard of living, while other variables insignificantly impact standard of living in Nigeria. However, the Granger causality test showed that the Per Capita Gross Domestic Product granger causes the Value of Transaction in the Capital Market; implying that Standard of living in Nigeria that determines the Value of Transactions in the Capital Market and not the other way round. It is also observed that Per Capita Gross Domestic Product (standard of living indicator) is not autoregressive or does not reinforce itself; which statistically is confirmed evidence showing that standard of living in the past cannot predict future standard of living in Nigeria. It is on these premises that the researchers recommend among others that policies should be put in place to enhance the growth of the capital market which will ultimately impact on the standard of living of Nigerians. Keywords: Standard of living, Capital market, ECM, Nigeria DOI: 10.7176/RJFA/13-12-07 Publication date:June 30th 202

Electricity generation potential of poultry droppings wastewater in microbial fuel cell using rice husk charcoal electrodes

Abstract Background Poultry droppings from poultry farms and rice husks obtained from rice milling process are generally considered as wastes and discarded in Nigeria. Although many studies have shown that microbial fuel cells (MFCs) can generate electricity from organic wastes, little or no study have examined MFCs for generating electricity from poultry droppings and rice husk as electrode material. Findings Laboratory-scale double-chamber MFCs were inoculated with concentrations of poultry droppings wastewater and supplied with rice husk charcoal as anode and cathode electrodes for electricity generation. Power outputs and dissolved organic carbon (DOC) removal efficiencies were compared between MFCs using rice husk charcoal (RHCE) as electrode and those using carbon cloth (CCE) as electrodes. The RHCE-MFC 2 containing 477 mg L−1 dissolved organic carbon produced a volumetric power density of 6.9 ± 3.1 W m−3 which was higher than the control and the CCE-MFCs by a factor of 2 and achieved at DOC removal efficiencies of 40 ± 1.2%. Conclusions The results suggest that poultry droppings wastewater is a feasible feedstock for generating electricity in MFCs. The findings also suggest that rice husk charcoal is a potentially useful electrode material in MFCs

Heterosis and combining ability in cucumber (Cucumis sativus L.)

The objective of this work was to evaluate four parental lines of cucumber which included: ‘Zeina’ (Zna), ‘Beit Alpha’ (BA), ‘Straight 8’ (Strght 8) and ‘Calypso’ (Capso) and six F1s generated by diallel cross, using randomized complete block design with three replications to study heterosis and combining ability for yield and yield component traits. Estimated heterosis showed that cross ‘Zna × Capso’ had the highest Better Parent (BP) heterosis in total fruit yield/ha while ‘BA × Capso’ had the highest Mid Parent (MP) heterosis in the same trait. Significant general (GCA) and specific (SCA) combining ability variances were obtained in all the traits implying that both the additive and non-additive gene effects operated in the genetic expression of the traits. Relative magnitude of GCA and SCA variances indicated preponderance of additive gene action for all the traits. ‘Beit Alpha’ and ‘Straight 8’ are best general combiners while ‘BA × Capso’ and ‘Capso × Strght 8’ were the best specific combiners for total fruit yield. Keywords: Cucumber, Hybrid vigour, Half diallel crosses, GCA, SC