Journals National University of Science and Technology (NUST)
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Inhibitory and stimulative effects of Lantana camara L. leaves on Lycopersicum esculentus and Lactuca sativa seedlings
Get PDFThe study was carried out to determine the allelopathic effects of these mulches on germination and early growth of Lycopersicumesculentus and Lactuca sativa which are common vegetables in Zimbabwe. Laboratory and greenhouse experiments wereconducted. A laboratory experiment with six treatments: 0, 1, 2, 3, 4 and 5 % aqueous concentration of Lantana camara leafextracts was set up in the laboratory and was replicated three times and repeated twice over time. A greenhouse experiment inwhich L. camara dry matter was incorporated into the soil with 0, 1, 10, 20, 30, 40 and 50 grammes per pot of dry leaf biomassreplicated three times and repeated twice over time ws also set up. The results indicated that Lantana leaf extracts significantlyreduced (P<0.05) the germination, radicle length and plumule length of tomatoes but not for plumule length for lettuce. The level ofinhibition was positively correlated to the concentration of the Lantana extracts on both vegetables. However, in the greenhouse,biomass of both vegetables was not affected by increase in Lantana concentration up to 40 g/pot. In this study, inhibitory effects ofLantana were observed in the laboratory but not in the green house where ground leaf biomass was mixed with red clay soil with aclay content of 33.5 %. The dry matter of lettuce increased with increase in L camara up to 30 g/pot and then decreased. Fortomatoes, it increased up to 40g/pot and then decreased raising the possibility of using reduced lantana camara rates to stimulatedry matter accumulation for both tomatoes and lettuce
Credit scoring using machine learning algorithims
Get PDFCredit risk mitigation is an area of renewed interest due to the 2007-2008 financial crises and thus masses of data are collected by the financial institutions. This has left the risk analysts with a daunting task of adequately determining the credit worthiness of an individual. In the search for highly efficient credit scoring models, financial institutions can adopt sophisticated machine learningtechniques. We employ the AUROC approach to make a comparative analysis of machine learning methods of classification by performing 10-fold cross validation for model selection on the German Credit data set from the UCI database. The results show that Lasso regression provides the best estimation for default with an AUROC of 0.8048 followed by the Random Forest model with 0.7869 AUROC. The widely used logit model performed better than the Support Vector Machine (Linear) with 0.7678 and 0.7581 AUROC respectively. Moreover, by the Kolmogorov-Smirnov test, we proved that the other machine learning techniques outperform the widely used logit model in how well the model is able to classify “good” class from “bad” class
Manufacturing information and database systems adoption and usage trends in Zimbabwe’s industries
Get PDF In the modern day’s global environment, data and information has become a central productive and strategic asset, and the success of the organization depends on its ability to gather, produce, maintain and disseminate this information for its benefit and those in its value chain. The article details the results from a study concerning different types of software packages used by Zimbabwe’s manufacturing and engineering firms. The participants were categorized into six industries as, Academic, Power Generation, Manufacturing Chemicals, Manufacturing Engineering, Mining and Transportation. The study revealed that 97% of the companies under investigation had a software package installed for their operations. The “big five” software packages in use in Zimbabwe are SYSPRO, SAGE, SAP, ELLIPSE, Navision and SCADA DELTA V. In the manufacturing sector SYSPRO has the largest market share of 86%. ELLIPSE is largely used in the mining sectors. Companies spend approximately 20 000 as initial investment on the software and nearly 2 000 annually on license fees. More than 50% of the software users are satisfied with the performance of their software packages. 
Pest resistance management strategies: A mini review of the case of cotton (Gossypium hirsutum) in Zimbabwe
Get PDFCotton is an important cash crop for the Zimbabwe’s smallholder sector but it is attacked by numerous pests that need to be managed. The economic method of cotton pest control is- integrated pest management that reduces the risk of resistance development to pests. This involves rotation of bollworm insecticides within the season, closed season for pink bollworm control, acaricide rotation scheme for sustainable red spider mite control. The land reform programme brought new farmers in the industry and new players in the agrochemical industry who are not aware of the integrated pest resistance management that delayresistance development in the cotton industry. This has been caused by shortage of chemicals in the market and collapse of some of the institutions which used to be custodians of the resistance management programme
Proximate and antioxidant activity analyses of six indigenous Nigerian vegetables
Get PDFSix commonly consumed indigenous vegetables in Nigeria, Ocimum gratissimum, Talinum triangulare, Telfairia occidentalis,Amaranthus hybridus, Vernonia amygdalina, and Basella alba were analysed for their proximate composition and antioxidantproperties. The antioxidant properties were measured qualitatively and quantitatively by DPPH. The ash contents of thevegetables ranged from 3.99±0.01 to 11.5±1.40%, while the crude fibre content was between 5.35±0.04 and 10.20±0.1% basedon dry weight. B. alba had the highest moisture content (92.55±0.07%), but the lowest ash and crude fibre contents.All thevegetable extracts exhibited antioxidant activities in terms of free radical scavenging abilities and the activities were concentrationdependent. O. gratissimum and V. amygdalina exhibited antioxidant activities that were comparable to the reference antioxidantcompound, ascorbic acid. The vegetables contained different quantities of phenolic compounds, which seemed significantlycontributing to differences in their antioxidant activities. The IC50 value of A. hybridus, O. gratissimum, V. amygdalina, B. albaand T. occidentalis were 0.20, 1.23, 10.52, 44.65 and 76.90 µg/mL respectively. All the vegetables displayed high antioxidantability except T. trianguleae with IC50 502.81 µg/mL. Our results showed that all the vegetables are suitable sources of antioxidantcompounds and could be health promoting. 
Dehydration and Rehydration Characterization of Yam (Dioscorea Rotundata) Tuber Slices Dehydrated Using a Refractance Windowtm Dryer
Get PDFThe effect of slice thickness on the dehydration and rehydration characteristics of yam was studied in a Refractance Window TM (RW) type dryer constructed from a laboratory water bath. Yam slices 1.5, 3.0 and 4.5 mm thick were dried in a laboratory scale RW dryer where the water in the bath was maintained at temperature of 80 °C. The initial moisture content of the yam samples was 69% on a wet basis (wb). The drying process was carried out until the final moisture content of the product was below 10% (wb). The experimental data indicate that the drying time decreases rapidly as the yam slices decrease; the 1.5 mm, 3.0 mm and 4.5 mm thick yam slices, dried to below 10% within 40 minutes, 80 minutes and 120 minutes respectively. The experimental data indicated that the drying kinetics for the yam slices fitted the Haghi and Ghanadzadeh thin-layer drying model with a regression coefficient exceeding 99.9 % for the 1.5, 3.0 and 4.5 mm thick slices. The rehydration ratio increased to a steady value of about 1.91 when soaked in water for about 180 minutes
Design of a Support Vector Machine Aided Real Time Health Information Text Extraction System
Get PDFThe exponential growth of available information sources has greatly affected the access to useable health information. As a consequence, medically biased information has become difficult to use for decision making. In this paper, we consider these consequences and present an enhanced method for accessing health information in real time. The approach involves the use of the vapnik Support Vector Machine process for text classification. The proposed method was frameworked on php/mysql for web user. Experimental setup shows that the method outperforms the baseline in the Precision, Recall and F1 measures. An extension using the Gaussian kernel is recommended in the pape
Development of Computer Aided Design Software for Piston Movement
Get PDFPiston is a component that plays vital roles in internal combustion engines such as in reciprocating engines, rotating pumps and so on. It is found in the cylinder of an engine block. The computations involved in piston movement in the cylinder of an engine are complicated and rigorous because of all the parameters involved. In order to obtain the required details, a computer aided design (CAD) software package is importantly needed not only to expose and do the intricate engineering analysis but also to show high accuracy of the developed software during simulation. The software was designed using Microsoft Visual Studio package because it supports and has built in languages such as C/C++ (visual C++), VB.Net (visual basic.Net) and C# (visual C#). However, the programming language used in the development of this software was Microsoft C#. The CAD developed for the piston movement was tested to be highly accurate, faster and convenient. This makes the CAD software developed viable to be used in monitoring piston movement
Some Robust Liu Estimators
Get PDFIn a classical linear regression model, Liu and Robust Estimators were developed to deal with the problem of multicollinearity and outliers respectively. This paper proposes some robust Liu estimators (RLEs) to jointly address the problem of multicollinearity and outliers and illustrates the proposed estimators with real life data sets. Based on the performances of these estimators using the Mean Square Error criterion, results show that the Robust Liu Estimators perform better than the ordinary least square (OLS), Liu estimator and Robust estimators when data sets suffer both problems. Furthermore, it is observed that the M Robust Liu Estimator (MRLE) is most efficient when outliers are in the y-direction; and when outliers are in the x or both y and x direction, the LTS Robust Liu Estimator (LTSRLE) is most efficien
Morphological Evaluation of the Effects of Ethanolic Leaf- Extract of Newbouldia Laevis (P. Beauv.) on Streptozotocin-Induced Gonadotoxicity in Adult Male Wistar Rats
Get PDFThe study was designed to assess the effects of Newbouldia laevis on diabetes-induced testicular damage. Forty-two Wistar rats (200 - 250 g) were categorized into six groups- control, saline, diabetic, pre-diabetic, post-diabetic and extract only, each comprising of seven rats per group, to assess the effects of ethanolic leaf extract of Newbouldia laevis on streptozotocin-induced testicular damage. The control group and others received feed mash and water ad libitum, the saline group had saline intraperitoneally. Diabetes was induced in the treatment groups following overnight fasting, through intraperitoneal (i.p.) single dose of streptozotocin (55 mg/kg). The pre-diabetic extract treated group received 100 mg/kg of extract in the first twelve weeks before they were induced with diabetes. The diabetic group was induced with diabetes on the twelfth week but without extract treatment. The post-diabetic group was induced on the eighth week and had twelve weeks of extract at 100 mg/kg body weight post-induction. The extract-only treated group received only the 100mg/kg of ethanolic leaf extract of Newbouldia laevis only for twelve weeks. All the groups were sacrificed at the end of the twenty-fourth week. The effects of these treatments on the hormonal profile, testicular and epididymal cytoarchitecture of the Wistar rats were assessed. There were significant (p<0.05) changes in oestrogen, luteinizing hormone, prolactin, testosterone values and oestrogen-testosterone ratio mainly in the diabetic and post-diabetic groups but insignificant (p>0.05) follicle-stimulating hormone and progesterone values compared to control. The sections of the testes and epididymis from the diabetic group had various cytoarchitectural lesions, inflamed testicular interstitium, luminal depletion of spermatozoa and arrested spermatogenesis. The post-diabetic group suffered less severe lesions. The pre-diabetic group had testicular lumen containing matured spermatozoa from normal spermatogenesis. The findings of this investigation confirm protective effects of ethanolic leaf-extract of Newbouldia laevis on streptozotocin-induced gonadotoxicity in male Wistar rats