Application of Split Desktop Image Analysis and Kuz-Ram Empirical Model for Evaluation of Blast Fragmentation Efficiency in a Typical Granite Quarry

Evaluation of fragmentation efficiency is an integral aspect of blasting operation. This study therefore assesses the efficiency of fragmentation size at Eminent granite quarry, Ibadan, Nigeria using Split Desktop software and Kuz-Ram empirical model. Five muckpiles of blasted rocks with the same blast design were analysed. The muckpile images were captured using smart high precision digital camera and uploaded into computer for Split Desktop analysis. The results of the fragment size distribution obtained from Kuz-Ram vary slightly with that of the Split Desktop but follow similar trend. The average values of F80 and F90 from the Split Desktop image analysis were 90.96 cm and 98.24 cm respectively. The Kuz-Ram model values for F80 and F90 were 88.52 cm and 92.95 cm respectively. The results of the Split Desktop were compared to the results obtained from the Kuz-Ram experiential model. The findings showed that the results obtained from Kuz-Ram empirical model were in conformity with the results from the Split Desktop software based on empirical relationship. Hence, the model is good for preliminary evaluation of blast design.   Keywords: Blasting, Particle Size Distribution, Split Desktop Software, Muckpile, Fragmentation Indicato

Development of a Stope Stability Prediction Model Using Ensemble Learning Techniques - A Case Study

The consequences of collapsed stopes can be dire in the mining industry. This can lead to the revocation of a mining license in most jurisdictions, especially when the harm costs lives. Therefore, as a mine planning and technical services engineer, it is imperative to estimate the stability status of stopes. This study has attempted to produce a stope stability prediction model adopted from stability graph using ensemble learning techniques. This study was conducted using 472 case histories from 120 stopes of AngloGold Ashanti Ghana, Obuasi Mine. Random Forest, Gradient Boosting, Bootstrap Aggregating and Adaptive Boosting classification algorithms were used to produce the models. A comparative analysis was done using six classification performance metrics namely Accuracy, Precision, Sensitivity, F1-score, Specificity and Mathews Correlation Coefficient (MCC) to determine which ensemble learning technique performed best in predicting the stability of a stope. The Bootstrap Aggregating model obtained the highest MCC score of 96.84% while the Adaptive Boosting model obtained the lowest score. The Specificity scores in decreasing order of performance were 98.95%, 97.89%, 96.32% and 95.26% for Bootstrap Aggregating, Gradient Boosting, Random Forest and Adaptive Boosting respectively. The results showed equal Accuracy, Precision, F1-score and Sensitivity score of 97.89% for the Bootstrap Aggregating model while the same observation was made for Adaptive Boosting, Gradient Boosting and Random Forest with 90.53%, 92.63% and 95.79% scores respectively. At a 95% confidence interval using Wilson Score Interval, the results showed that the Bootstrap Aggregating model produced the minimal error and hence was selected as the alternative stope design tool for predicting the stability status of stopes.   Keywords: Stope Stability, Ensemble Learning Techniques, Stability Graph, Machine Learnin

A patient-initiated DMARD selfmonitoring service for people with rheumatoid or psoriatic arthritis on methotrexate: a randomised controlled trial

Objective: To determine the effectiveness of a patient-initiated DMARD self-monitoring service for people with rheumatoid (RA) or psoriatic arthritis (PsA) on methotrexate. Methods: A two-arm, single centre, randomised controlled trial assessing superiority in relation to healthcare utilisation, clinical and psychosocial outcomes. Participants were 100 adults with either RA or PsA on a stable dose of methotrexate, randomly assigned to usual care or the patient-initiated service. Intervention participants were trained how to understand and interpret their blood tests and use this information to initiate care from their clinical nurse specialist (CNS). The primary outcome was the number of outpatient visits to the CNS during the trial period. Differences between groups were analysed using Poisson regression models. Secondary outcomes were collected at baseline and after the 3rd and 6th blood tests. Disease activity was measured using either the DAS28 or PsARC, pain and fatigue using a visual numeric scale and the HAQII, HADS and SF12 were completed to assess disability, mood and quality of life, respectively. Differences between groups over time on secondary outcomes were analysed using multi-level models. Results: The patient-initiated DMARD self-monitoring service was associated with 54.55% fewer visits to the CNS (p<0.0001), 6.80% fewer visits to the rheumatologist (p=0.23) and 38.80% fewer visits to the GP (p=0.07), compared with control participants. There was no association between trial arm and any of the clinical or psychosocial outcomes. Conclusions: The results suggest that a patient-initiated service that incorporates patients self-monitoring DMARD therapy can lead to significant reductions in healthcare utilisation, whilst maintaining clinical and psychosocial well-being

HPLC quantification of phenolic content and assessment of methanolic extract of Antiaris africana for toxicological study

The study was aimed at evaluating the toxicological and antioxidant activities of Antiaris africana Engl. (family Moraceae), that is used in Nigeria and other West Africa countries as a panacea for the treatment of several ailments. The methanolic extract of A. africana (MEA) obtained was analysed for antioxidant activities in vitro and screened for various phytochemicals present. Phenolic and flavonoid contents were determined followed with high performance liquid chromatography -diode-array detection (HPLC-DAD) fingerprinting of phenolic content. Furthermore, the sub-acute toxicity of MEA was determined via oral administration of varying doses for 14 consecutive days (0, 50, 100, 200 and 400 mg/kg) in rats. After oral administration for 14 consecutive days in male rats, the toxicity effect was assayed by determining aspartate aminotransferase (AST) and alanine aminotransferase (ALT) for hepatic function; urea and creatinine for renal function; creatinine kinase (CK) for cardiac function; and lipid profile. HPLC results showed that the major phenolics present are quercetin, rutin, caffeic acid, garlic acid and quercetin. MEA was able to scavenge diphenyl picryl hydrazyl, hydroxyl and nitric oxide radicals and prevent lipid peroxidation induced by ferrous sulphate at all concentration tested. The toxicology investigation showed that at low doses, A. africana is non-toxic, while at high doses; it is moderately toxic to the animals. In conclusion, A. Africana is generally non-toxic; however, care must be taken in administration at higher doses.Keywords: Toxicology, HPLC, phytochemicals, Antiaris african

Evaluation of physical characteristics of chevon as affected by post-mortem carcass dressing and freezing preservation

This study was conducted to investigate the effects of post-mortem dressing methods and freezing preservation on the physical characteristics of chevon. Twenty-seven Red-Sokoto male goats between 10 and 12 months of age weighing 18–20 kg were purchased, stabilized and slaughtered. The carcasses were randomly allotted to three post-mortem dressing procedures (scalding, skinning and singeing) and meat from thigh cuts was frozen for 0, 7, 14 and 21 days. Meat samples were excised each day after thawing for physical analysis and data collected were subjected to analysis of variance (ANOVA) in a completely randomized design experiment with 3x4 factorial arrangement. The significant means were separated with the Duncan multiple range test at p&lt;0.05. The results showed that the post-mortem dressing methods and freezing affected Red-Sokoto chevon significantly with the singeing method exerting the highest detrimental effects on physical attributes of meat with the exception of color, yield and pH, while the skinning method exerted the least detrimental effects. Also, cold, cooking and drip losses as well as thermal shortening, cold shortening and pH values increased between the 14th and 21st day, while color, yield, water holding capacity, texture and shear force values decreased across the three treatments during freezing periods. The effects were more significant in singed and scalded meat than in skinned chevon. It was recommended, therefore, that skinning method be encouraged if meat from Red-sokoto male goats is to be frozen and the period of freezing be limited to 14 days for wholesome meat

Antioxidant and antiulcer potential of aqueous leaf extract of Kigelia africana against ethanol-induced ulcer in rats

Ethnobotanical claims regarding Kigelia africana reported antiulcer properties as part of its medicinal application. In this work, aqueous leaf extract from K. africana was investigated for its phytochemical constituents and antiulcer potential against ethanol-induced ulcer in rats. The participation of oxidative stress on ethanol-induced ulcer and the potential protective antioxidant activity of K. africana extracts were investigated by determining vitamin C and thiobarbituric acid reactive species (TBARS) contents in the gastric mucosa of rats. The HPLC analysis showed the presence of gallic acid, chlorogenic acid, caffeic acid and also the flavonoids rutin, quercetin and kaempferol in the aqueous plant extract. Oral treatment with K. africana extract (1.75; 3.5; 7 and 14mg/kg) one hour after ulcer induction with ethanol decreased in a dose dependent manner the ulcer index. Ethanol increased significantly stomachal TBARS levels and decreased vitamin C content when compared to the control animals. K. africana blunted the ethanol-induced oxidative stress and restored vitamin C content to the control levels. The present results indicate that the aqueous leaf extract from K. africana possesses antiulcer potential. The presence of flavonoids in plant extract suggests that its antiulcerogenic potential is associated with antioxidant activity. Of particular therapeutic potential, K. africana was effective against ethanol even after the induction of ulcer, indicating that it can have protective and curative effects against gastric lesion

Correlation between serum uric acid levels and outcomes of pre-eclampsia in Abakaliki, South-east, Nigeria

Background: Pre-eclampsia is a leading cause of fetomaternal and perinatal morbidity and mortality. The role of serum uric acid (SUA) in determining the complications of preeclampsia has been controversial. This study compared mean SUA levels between severe pre-eclamptics and normotensive women at term and ascertained its correlation with outcomes of preeclampsia; as well as determined if there is a threshold value of SUA level beyond which fetomaternal complications occur.Methods: A case-controlled study where 80 severe pre-eclamptics at term and 80 normotensive women matched for gestational age were recruited. Blood samples were collected from them for assay of SUA levels and they were followed till delivery. The fetomaternal outcomes and the corresponding SUA levels at diagnosis were documented and variables statistically analyzed. A receiver operating characteristic curve was used to determine the cut-off value of SUA beyond which adverse fetomateral complications are likely to occur in pre-eclampsia.Results: The mean SUA level in severe pre-eclamptics (0.283±0.09 mmol/l) was not significantly higher than that of normotensive women (0.263±0.09 mmol/l, p=0.13). There was a weak positive correlation between the SUA levels and fetomaternal outcomes [maternal (r=0.102, p=0.236) and fetal (r=0.096, p=0.226)]. The study was unable to identify the threshold SUA level at which adverse fetomaternal outcomes occur as the values of SUA were closely related.Conclusions: SUA levels of pre-eclamptics and normotensive women did not show significant difference and correlated weakly with fetomaternal outcomes and are therefore poor predictor of fetomaternal outcomes in pre-eclampsia