Semi-Parametric Non-Proportional Hazard Model With Time Varying Covariate

The application of survival analysis has extended the importance of statistical methods for time to event data that incorporate time dependent covariates. The Cox proportional hazards model is one such method that is widely used. An extension of the Cox model with time-dependent covariates was adopted when proportionality assumption are violated. The purpose of this study is to validate the model assumption when hazard rate varies with time. This approach is applied to model data on duration of infertility subject to time varying covariate. Validity is assessed by a set of simulation experiments and results indicate that a non proportional hazard model performs well in the phase of violated assumptions of the Cox proportional hazards

Extended Cox Modelling of Survival Data with Guarantee Time

Proportional Hazard regression model for censored survival data often specifies that covariates have a proportional fixed effect on the hazard function of the lifetime distribution of a subject. A modification of the proportional hazards model of Cox (1972) to accommodate the non-proportional effect on hazard with a time-varying covariate and the introduction of guarantee time into the Weibull distributed baseline hazard function. Simulations were conducted to investigate properties of the models. Our approach had shown to have the best asymptotic properties in a simulation study with mean, Absolute Bias (AB) and Mean Square Error (MSE) of the parameter estimates for the models (under different levels of censoring and sample sizes) using simulated data

BIOCHEMICAL CHANGES IN STREPTOZOTOCIN-INDUCED DIABETIC RATS AFTER TREATMENT WITH ETHANOLIC LEAF EXTRACT OF Croton Zambesicus (Müll. Arg.)

Objective: This study was designed to evaluate the effect of ethanolic leaf extract of C. zambesicus on total protein (TP), albumin (ALB), globulin (GLO), lactate dehydrogenase (LDH) and glucose-6-phosphate dehydrogenase (G6PDH) in streptozotocin (STZ) induced diabetic rats. Methods: Seventy adult male wistar rats were divided into seven groups (n=10). Group A, control rats; Group B, untreated diabetic rats; Group C, diabetic rats in which C. zambesicus therapy started 2 weeks prior to induction of diabetes; Group D, diabetic rats administered orally with C. zambesicus leafextract for 2 weeks after the initial four weeks of diabetic induction; Group E, diabetic rats administered orally with C. zambesicus leaf extract for 4 weeks after the initial four weeks of diabetic induction; Group F, normal rats administered orally with C. zambesicus leaf extract for four weeks; Group G, diabetic rats administered with glimepiride (2 mg/kg/day) for four weeks after the initial four weeks of diabetic induction. At the end of the experimental period, the animals were weighed and sacrificed. Serum was obtained for TP, ALB, LDH and G6PDH analysis using respective diagnostic kits. Results: The results showed an improvement in protein metaboloites (TP, ALB, GLO) whiles the LDH and G6PDH in the extract and glimepiride treated groups were restored near normal level when compared with normal control (group A). Conclusion: In conclusion, this study showed that C. zambesicus leaf extract exerts positive effects on serum levels of TP, ALB, GLO, LDH and G6PDH in diabetic rats. Thus, ethanolic leaf extract of Croton zambesicus can be adopted in the management of diabetes mellitus

QUALITY OF WORK-LIFE AND ORGANIZATIONAL COMMITMENT AMONG ACADEMICS IN TERTIARY EDUCATION

This study investigates the relationship between quality of work-life and organizational commitment in the academic environment. Dimensions of quality work- life examined include career advancement, job security, pay benefit and employee participation in decision-making. The study adopted the survey method with data collected from a sample of two hundred and ninety-three (293) randomly selected respondents in a private-mission owned university in Nigeria. Results of data analysis indicate a negative relationship between career advancement, job security and organizational commitment. However, positive relationship was found to exist between employee participation, job satisfaction and organizational commitment. The study suggests the imperative for tertiary education institutional managers to prioritize specific dimensions of employee quality of work-life as an integral antecedent to the achievement of organizational objectives. This holds promise to attaining global standard

2k Factorial Experiments on Factors that Influence the Recovery of Gold during the Upgrade of Ilesha-Itagunmodi Gold Ore through Froth Flotation

A low-grade gold ore from Ilesha-Itagunmodi, south western Nigeria was panned, dried and ball-milled before sieving into fractions. The morphological, mineralogical and chemical composition was studied by optical micro-scopy (Reflected and Transmission), X-ray diffraction (XRD) and Energy Dispersive X-ray fluorescence (XRF), respectively. The sieved fractions were subjected to chemical analysis (AAS). The +106 μm sieve had the highest concentration of the mineral and was then selected for the upgrade through froth flotation using standard rea-gents. In this paper a report on a 2k factorial experiment that provides an understanding of the impact of opera-tional variables on the quantity of gold mineral obtained from the ore during froth flotation is presented. Analy-sis results showed that Ilesha-Itagunmodi gold ore is non-refractory with fine grain particles, amenable to froth flotation and contained about 20 other associated minerals, gold had a concentration of about 0.0024%. A com-bination of P-Xanthate and amine glycol collectors at a pH of 9.2 only produced a considerable increase in gold yield. This translated to about 87.13% increase in recovery of gold from the ore. Analysis of variance (ANOVA) was carried out and the model equation obtained was subsequently optimised to obtain a model equation that could be used in predicting the recoverable quantity of gold, indicating that F11,1-values for Collector concentra-tion, Frother concentration, pH and Conditioning time were 156.86, 6.96, 43.81, and 56.77 respectively. A model with an F value of 88.41 was obtained which indicated that the model was significant. The model equation obtained was subsequently optimised to be able to predict the recoverable quantity of gold. A “Pred R-Squared” value of 0.9365 (93.65%) was also obtained and is in reasonable agreement with the “Adj R-Squared” value of 0.9534 (95.34%). It was established that Ilesha placer gold ore is amenable to froth flotation using standard reagents

Reducing the environmental impact of surgery on a global scale: systematic review and co-prioritization with healthcare workers in 132 countries

Abstract Background Healthcare cannot achieve net-zero carbon without addressing operating theatres. The aim of this study was to prioritize feasible interventions to reduce the environmental impact of operating theatres. Methods This study adopted a four-phase Delphi consensus co-prioritization methodology. In phase 1, a systematic review of published interventions and global consultation of perioperative healthcare professionals were used to longlist interventions. In phase 2, iterative thematic analysis consolidated comparable interventions into a shortlist. In phase 3, the shortlist was co-prioritized based on patient and clinician views on acceptability, feasibility, and safety. In phase 4, ranked lists of interventions were presented by their relevance to high-income countries and low–middle-income countries. Results In phase 1, 43 interventions were identified, which had low uptake in practice according to 3042 professionals globally. In phase 2, a shortlist of 15 intervention domains was generated. In phase 3, interventions were deemed acceptable for more than 90 per cent of patients except for reducing general anaesthesia (84 per cent) and re-sterilization of ‘single-use’ consumables (86 per cent). In phase 4, the top three shortlisted interventions for high-income countries were: introducing recycling; reducing use of anaesthetic gases; and appropriate clinical waste processing. In phase 4, the top three shortlisted interventions for low–middle-income countries were: introducing reusable surgical devices; reducing use of consumables; and reducing the use of general anaesthesia. Conclusion This is a step toward environmentally sustainable operating environments with actionable interventions applicable to both high– and low–middle–income countries

Design of a Multiepitope Vaccine against Chicken Anemia Virus Disease

Chicken anemia virus (CAV) causes severe clinical and sub-clinical infection in poultry globally and thus leads to economic losses. The drawbacks of the commercially available vaccines against CAV disease signal the need for a novel, safe, and effective vaccine design. In this study, a multiepitope vaccine (MEV) consisting of T-cell and B-cell epitopes from CAV viral proteins (VP1 and VP2) was computationally constructed with the help of linkers and adjuvant. The 3D model of the MEV construct was refined and validated by different online bioinformatics tools. Molecular docking showed stable interaction of the MEV construct with TLR3, and this was confirmed by Molecular Dynamics Simulation. Codon optimization and in silico cloning of the vaccine in pET-28a (+) vector also showed its potential expression in the E. coli K12 system. The immune simulation also indicated the ability of this vaccine to induce an effective immune response against this virus. Although the vaccine in this study was computationally constructed and still requires further in vivo study to confirm its effectiveness, this study marks a very important step towards designing a potential vaccine against CAV disease

Retracted: Supracondylar Osteochondroma in a Black South African Population

This journal has been retracted by the Editor.Osteochondroma is a condition characterized by a benign outgrowth of bone  on the surface of another bone. The present study reports the presence of  osteochondroma in the supracondylar region of the right femur of a Black  South African during a routine osteological study. The diameter of the   exostosis measured 15.7 mm at the tip and 26.3 mm at the base. The exostosis is about 30.8 mm from the base of the epicondyle. It is 24.8 mm in length. Gross examination suggests a feature of osteochondroma.Keywords: Femur, Osteochondroma, South Africa, tumo

Tomato (Lycopersicon esculentum) prevents lead-induced testicular toxicity

Background: Lead, an example of heavy metals, has, for decades, being known for its adverse effects on various body organs and systems such that their functions are compromised. Aim: In the present study, the ability of lead to adversely affect the male reproductive system was investigated and tomato ( Lycopersicon esculentum : Source of antioxidants) paste (TP) was administered orally to prevent the adverse effects of Pb. Materials and Methods: Fifteen Sprague Dawley rats, randomised into three groups (n = 5), were used for this study. Animals in Group A served as the control and were drinking distilled water. Animals in Groups B and C were drinking 1% Pb (II) acetate (LA). Group C animals were, in addition to drinking LA, treated with 1.5 ml of TP/day. All treatments were for 8 weeks. Statistical Analysis Used: A Mann-Whitney U -test was used to analyse the results obtained. Results: The obtained results showed that Pb caused a significant reduction in the testicular weight, sperm count, life-death ratio, sperm motility, normal sperm morphology, and plasma and tissue superoxide dismutase and catalase activity, but a significant increase in plasma and tissue malondialdehyde concentration. But, Pb did not cause any significant change in the serum testosterone level. TP, however, significantly reduced these adverse effects of Pb. Conclusion: These findings lead to the conclusion that TP significantly lowered the adverse effects of Pb exposure on the kidney as well as Pb-induced oxidative stress