SOME NEW ADJUSTED RIDGE ESTIMATORS OF LINEAR REGRESSION MODEL

The ridge estimator for handling multicollinearity problem in linear regression model requires the use the biasing parameter. In this paper, some new adjusted ridge parameters which do not require the biasing parameter are proposed. The performances of the proposed Adjusted Ridge Estimators are compared with a recently proposed Adjusted Ridge Estimator, Generalized Ridge Regression Estimator (GRRE), Ordinary Ridge Regression Estimator (ORRE) and Ordinary Least Square estimator (OLSE) via Monte Carlo study by counting the number of times each estimator has smallest Mean Square Error (MSE) in ten thousand (10,000) replications. The proposed Adjusted Ridge Estimator is most efficient especially when multicollinearity is severe and the error variance is high

MECHANICAL BEHAVIOUR OF MORINGA OLEIFERA SEEDS UNDER COMPRESSION LOADING

Mechanical properties of Moringa oleifera of relevance to seed handling were determined. The properties determined were force, deformation, stress and energy at various compression loadings (peak, break, and yield), including the young modulus. The peak value occurs at force of 76N, strain of 41 for undehusked while for dehusked, the peak value for force is 96N and for strain is 64 respectively. The linear relationship at the peak, break and yield point was observed to be y = 0.253x + 48.72; y = -0.004x + 59.68 and y = -0.076x + 25.40 respectively. The results shows that the force correlation was positively weak (0.1842) at peak point and negatively weak (-0.0375 and -0.0918) at break and yield point respectively. The dehusked Moringa seeds possessed a relatively higher average force and stress than the undehusked seed at peak and break point, and otherwise at yield point, the inverse was the case of its energy properties. The young modulus of the undehusked seeds was however greater than the dehusked seeds and the elasticity for dehusked seed was also observed to be higher than undehusked moringa seed. Linear relationships that could be used at various compression loadings were established for both the undehusked and dehusked Moringa seeds

The effect of first line anti-retroviral drugs on the menstrual cycle of HIV positive patients

Background: The quality of life and life expectancy of individuals living with HIV has improved significantly. This improvement is largely due to the use of Highly Active Anti-Retroviral Therapy (HAART). The effect of prolonged usage of this therapy on the menstrual function of the females within the reproductive age range is poorly understood. Methodology: A cross-sectional comparative study that involved women within the reproductive age range of 15-45 years. The women were grouped into A, B and C categories. Group A had HIV positive women already on Anti-Retroviral (ARV) therapy. Group B were HIV positive women naïve to anti-retroviral drugs at the time of recruitment. Group C comprised of HIV negative women within the reproductive age range not being managed for infertility. Results: The mean age of the participants across the study groups were respectively 32 years, 33.4 years and 37.58 years. The average weight among participants in the study was 66.38 kg, with a range of 53-94 kg. The average duration of use of ARVs was 81.12 months (6.7 years). The mean CD4 values across the study population who were HIV positive were 725 and the average viral load was 20 copies per ml. The commonest menstrual abnormality was oligomenorrhea, occurring in close to 25% of respondent who were HIV positive and on ARVs. Menstrual abnormality was more in the HIV positive women receiving anti-retroviral drugs than in the other two cohorts. (p=0.007). Conclusion: Long term usage of some first line highly active anti-retroviral therapy is associated with increased menstrual abnormality