IRSPAS 2018

Permanent URI for this collectionhttp://repository.kln.ac.lk/handle/123456789/19084

Browse

Now showing 1 - 20 of 183

Time series modeling of red onion production in Jaffna, Sri Lanka
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Mirojan, U.; Varathan, N.; Arumairajan, S.
Onion is one of the most important commercial vegetable crops grown in Sri Lanka. Observing fluctuation of onion production is essential in the market economy. The level of the production and the fluctuation not only has a significant influence on farmers and consumers, but also a reasonable effect on the safe running of the onion in market. In this study, the annual production of red onion in Jaffna is modeled by using Box – Jenkins time series approach. The Onion production in Jaffna is cultivated in two seasons, Maha season: from September to March, Yala season: from April to August. The annual seasonal red onion production data was obtained from the office of the Deputy Provincial Director of Agriculture (Extension) during the period of 1987 to 2016. The main objective of this study is to find the suitable Auto Regressive Integrated Moving Average (ARIMA) model for the annual production of Red onion in Jaffna. Further, three statistical criteria such as Akaike’s information criteria, Bayesian information criteria, mean squared error were carried out in order to select the best ARIMA model. Through the modeling, it was identified that ARIMA (1,1,0) is the best fitting model to the given data. Moreover, the model validation has been done using the actual figures. Further, the identified best model can be used to predict the red onion production of Jaffna in near future.
Identification and evaluation of current socio-economic conditions for improvement of water supply and sanitation in rural areas in tropical regions;A study from Sri Lanka
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Bellanthudawa, B. K. A.; Wijesinghe, L.; Darshana, W. D.; Jayasooriya, J. M. S. N.; Sundarapperuma, S. R. Y. S. S. B.; Kumara, S. D. K. S.; Nawalage, N. M. S. K.; Samaradiwakara, T. C. B.
Empowering the water supply and sanitation is a concern in Sri Lanka.Thus, present study was carried out on Anhettigama area in Deraniyagala Divisional Secretariat Division (DSD) in Kegalle District to identify the socio-economic status in the study area for implementing a water supply and sanitation improvement project and identify crucial issues to implement water supply. A semi-structured questionnaire survey was conducted for households (n=50) for assessing the social-demographic and economic background of the community through random sampling technique in project impact area. Data analysis was conducted using Microsoft Excel 2013 software to compare the responses in graphical presentations. Majority (92%) indicated that their livelihood pattern as mixed economic. 86% of the families were headed by males whereas 14% families were headed by females in the project area. Project impact area was composed of 83% Sinhalese and 17% Tamil families. In terms of water consumption patterns, 34% of houses used existing “Suhada” water supply scheme and 66% fulfilled their water requirement from private protected and unprotected wells located within their premises. Surface well water usage was 32%, which was not safe unless subjected to disinfection before drinking. 72% of the respondents mentioned that water was insufficient during dry seasons, which may reduce the water quality as well. Majority of the respondents (92%) mentioned that they were not satisfied with their present water supply scheme. Since current drinking water has not undergone any treatment method, 96% people used domestic purification methods such as artificial filtering and boiling. About 84.9% of the households had proper sanitation facilities while 9.2% of the people did not have toilets. Out of these 84.9%, 50% accounted for water sealed toilets with cistern and 34.9% accounted for water sealed toilets without cistern. Since the current water supply was insufficient, 97% people were willing to pay a monthly water bill. 16% of households received the government food subsidy of Samurdhi given for households living below the official poverty line with regards to economy. 35% of the people were involved in professions in the private sector, 26% in agriculture, 12% were government employees while unemployed population was 5%. In conclusion, there is a necessity and high demand for pipe borne water, sanitation and economic development. Incorporation of a water supply and sanitation improvement project is a sustainable solution.
Study on subsoil profile analysis at Lamae district municipality ground, Chumphon city, Thailand by atomic absorption spectroscopy for forensic application
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Moorthy, T. N.
Soil is an important physical evidence used in crime investigation. It is a trace evidence found in shoes, shirts, head hairs, vehicle tyres, transferred from the crime site. Soil is a mixture of multi-minerals, plant materials, animal matters and tiny man-made materials like paint chips, glass pieces, concrete materials, oil stains and many more. Soil is composed of small particles and these particles vary in size, shape and chemical composition. Three types of soil particles are known viz. sand, silt and clay. Soil texture is determined by the relative amounts of sand, silt and clay in the soil. The combination of soil mixture makes it distinct and thus vary from one site to another. Even the color of soil vary from one place to another since color is an indicator of the chemical and physical characteristics of soils. The metal ion concentration plays a vital role for soil comparison. Similar to top soils, subsoil samples also show variation in density, pH and metal ion concentration. Comparison of soil trace is an important component to identify and link the primary and secondary crime scenes. Therefore, forensic scientists are interested in subsoil analysis for forensic application. The objective of this research was to analyse the subsoil profiles. Three soil samples each (500 g) were collected at three different points in the same ground, viz. top soil, soil at the depth of 15 cm, and 30 cm from a total of 9 soil samples from Lamae district municipality ground, Chumphon town, Southern Thailand and preserved. The color of the soil was noted by using Munsell color chart and pH of the soil samples were identified using pH paper. Atomic Absorption Spectroscopy (AAS) was used to determine the metal ions concentration of potassium, sodium, calcium, iron, lead, copper, chromium and cadmium from soil samples collected from different points and depths. Soil samples in point S1 showed that potassium metal ion concentration at 5.72 mg/kg in top soil sample, 11. 64 mg/kg in 15 cm subsoil and 7.23 mg/kg in 30 cm subsoil and show sub profile variation at the same point. Similar variations were observed in other metal ion concentrations. The results show that no two soil samples are same and all soil samples varied both physically and chemically. Hence, it is concluded that this method of soil analysis can be used for forensic application.
Correlation between selected morphological and biochemical parameters in a hybrid tea population with the blister blight disease
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Weerasooriya, C.R.; Kottawaarachchi, J.D.; Ranathunga, M.A.B.; Amarakoon, A.M.T.
Tea is produced from the plant species Camellia sinensis. Blister blight is a major leaf disease caused by the fungus Exobasidium vexans in tea resulting in significant yield losses, debilitation and death of tea bushes . Copper and systemic fungicides are currently used to control the disease resulting in high costs and potential residues in tea. In addition, there is a possibility of developing fungi resistance in tea plants to fungicides. Therefore, developing cultivars with resistance towards Blister blight is considered as the most suitable approach to control the disease. In the present study, the correlation between morphological and biochemical parameters was investigated with Blister blight disease with an aim to develop resistant cultivars. Twenty (20) tea samples including 18 accessions produced by crossing two parent cultivars: TRI 2043 (highly resistant to Blister blight) and TRI 3055 (highly susceptible to Blister blight) and the two parent cultivar samples were used in this study. The morphological analysis was carried out with reference to the guidelines given in the descriptors for tea by the International Plant Genetic Resources Institute (IPGRI) in 1997 and the descriptor list of the International Union for the Protection of New Varieties of Plants (UPOV) for tea (2008). Biochemical parameters were analysed following spectrophotometric methods and HPLC methods. Total anthocyanin, caffeine, polyphenol, gallic acid, epigallocatechin, catechin, epicatechin, epigallocatechin gallate and epicatechin gallate contents were determined. Results obtained for morphological and biochemical parameters were statistically analysed using the Minitab software under two categories; calculating the correlation between morphological and biochemical parameters and plotting a dendrogram for morphological and biochemical parameters separately. The Pearson correlation method was used to calculate the correlation between parameters. From the morphological parameters, a positive relationship was observed in the number of average pubescence on young leaf with the Blister blight resistance. Total anthocyanin content showed a positive relationship and epicatechin showed a low negative relationship with the Blister blight resistance. Accession 26 showed a very high total anthocyanin content (0.123 ± 0.065%), a moderate epicatechin content (0.792 ± 0.168%) and a high resistance to Blister blight disease, indicating its potential to be developed as a resistant cultivar. The experiment was duplicated, and the same results were obtained both times. Based on the results, it can be concluded that anthocyanin content can be suggested as a biochemical marker in tea crop improvement programs.
Survey on cyber security measures and their applicability in digital business ecosystem
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Subashini, K. K. P.; Fernando, S.
This paper evaluates the cyber security, attributes and culture which are critical for today business transactions. World is moving to sustainable digital business transformation. Therefore, we need to think the key important attributes of the digital maturity and modern organization culture as it definitely creates a delightful customer experience. Changes in cyber security definitely requires a new type of process and skills. Particularly, the software development process based on the security framework. Adaptive skills and innovation processors are key to the next phase of cyber security. Therefore, the main objective of this research is to suggest more suitable and proper approach to capitalize the cyber security for digital business ecosystem. As entry criteria for the main objective, a survey has been conducted to measure the effectiveness of the factors, which have been identified based on literature review on cyber security. The conclusion is derived based on the collected data. The research started with a literature survey to identify the factors that affect the security in global business ecosystem. A structured questionnaire was used as the research instrument to collect data from projects in IT companies in Sri Lanka. To gather data, 30 IT professionals were interviewed from 5 different companies. Survey participants were selected by using random sampling technique. According to the result shown in the survey 80% of the IT professionals are ready to capitalize the cyber security and receive information and upgrade their products.70% of the response indicate that, they are using security as nonfunctional requirement. 100% of professionals aware about the importance on cyber security. The results of the study shows that 90% of the clients are expecting security feature in their products. 40% of clients are not aware on the level of security they need. The cost for security enhancement is very high and due to this, 60% of clients are not willing to pay high amount of money for security establishment. Therefore they are satisfied with the low cost security tools or open source tools. The most highlighted barrier is that it discourages IT professionals using the commercialized security tool due to the fear to embrace new tool or process and lack of knowledge. The high cost of the tools and no define process to develop secure applications are the other main issues to be addressed in order to enhance cyber security in the global business ecosystem. Results have shown that the younger generation is willing to adopt and interested in the new technology. It also found that there is a gap in security expectations and software development process.
Cadmium and arsenic levels in edible fishes, Oreochromis niloticus (Nile tilapia) and Ompok bimaculatus (Pena walaya) from Padaviya reservoir of North Central Province, Sri Lanka
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Weerasekara, K.A.W.S.; Pathiratne, A.; Kithsiri, H.M.P.
Oreochromis niloticus (Nile tilapia) and Ompok bimaculatus (Pena walaya) are two edible fish species captured in the reservoirs in the North Central province. Objective of this study was to assess the cadmium and arsenic levels in muscle, liver and kidney tissues of O. niloticus and O. bimaculatus inhabiting the Padaviya reservoir to assess association of metal/metalloid levels in tissues with body weights, and total lengths of the fishes. The body weight (180-300g; 110-225g) and the total length (19.0-24.1cm; 24.0-34.0cm) of Nile Tilapia (n=30), and Pena walaya (n=30) respectively were recorded during three sampling events in 2018. The tissues were analyzed for cadmium and arsenic levels using Inductively Coupled Plasma Mass Spectrometry. Cadmium and arsenic contents of the muscle tissues were below the limit of detection (LOD) (<0.05 mg/kg wet weight) except cadmium in the muscle tissues of five Nile tilapia (0.05-0.10 mg/kg). Cadmium contents in the liver tissues of both Nile tilapia and Pena walaya, ranged from <0.05 to 0.14 mg/kg (wet weight) where cadmium levels of 67-70% of the fishes were below the LOD. Arsenic levels in liver tissues of Nile tilapia and Pena walaya were <0.05–0.10 mg/kg and <0.05–0.06 mg/kg respectively where arsenic levels in 83% of Nile tilapia and 97% of Pena walaya were below the LOD. Cadmium content in the kidney tissues of Nile tilapia and Pena walaya were <0.05-0.90 mg/kg and <0.05-0.40 mg/kg respectively where cadmium levels in 30% and 33% fishes were below the LOD. Arsenic was detected only in kidney tissues of 10% Nile tilapia (<0.050.46 mg/kg). Cadmium contents in liver tissues of Nile tilapia positively correlated (p <0.05) with the total length. No other significant associations were found between the metal/metalloid content in the tissues and the body size of the fishes. Results revealed that the cadmium and arsenic contents in the edible muscle tissues of most of these fishes were within the safe limits specified by the regulatory authorities for human consumption. Bioaccumulation pattern of cadmium in the tissues of both fishes followed the order: muscle < liver < kidney, showing greater cadmium bioaccumulative capacity in the kidney tissues. Periodic monitoring of metal/metalloid levels in edible fishes in Padaviya reservoir is recommended considering human safety. The data generated in this study can serve as baseline information for future monitoring and human health risk assessment programmes.
Factors associated with child abuse incidents in Chilaw police enforce division: case study
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Siriwardana, L. W. M. S.; Tissera, J. H. D. S. P.
Child abuse has become a major social issue across the world. Globally, millions of children suffer from maltreatment, exploitation and abuse. To avert children from such situations, it is important to identify respective causes. This research targeted Chilaw division, where a considerable fraction of child population suffers from numerous disciplines of abuses. The study was limited to sub areas of Chilaw police enforce division. The main objective of the study was to find out factors associated aforementioned categories. The response variable was taken as respective type of child abuse incident. Three categories of abuses were found as 159 rape cases, 77 cruelty and sexual abuses along with 60 kidnappings. Some of the explanatory variables were age of the victim, gender, whether the child was schooling, incident locations, relationship with abuser, age and occupation of abuser, guardianship of the child, occupation of parents and consent of the child. Data for the study was obtained through a questionnaire utilizing police records in respective areas. All recorded incidents (296) were included in the analysis. Initially the study majored on descriptive analysis to visualize the relationships between the variables. Then univariate analysis was carried out using Pearson’s chi squared test and Kruskal Wallis test for categorical data to identify the association between response variable and explanatory variables and extended to obtain the variables that are statistically significant. Type of child abuse incidents were modelled using Multinomial Logistic Regression (MLR). Likelihood ratio statistic was used to differentiate between the significant variable or the model. Akaike Information Criterion was used for model comparison. In order to assess the goodness of fit of the final model, likelihood ratio statistic deviance was used. Majority of the victims were abused in their own homes. The most vulnerable age group for raping was 15-18. Out of 70% of rape cases, the abuser was the boyfriend of the victim. It is interesting to see that most of these females were abused with their consent. The children of other age groups were not victims of raping prominently. Using the MLR model, stated variables were found to be the significant factors associated with type of child abuse incidents; age of victim, place of the incident, area of the incident, age of abuser, relationship with abuser, occupation of parents and consent of the child.
Chemical and functional properties of selected traditional rice ( Oryza sativa ) varieties
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Bhagy, K. A. D. L.; Ekanayake, S.
Rice is the single most important cereal consumed by Sri Lankans with a 114 kg per-capita consumption per year. Due to the current increase in the interest on consuming traditional rice varieties due to health benefits, information regarding chemical and the functional properties in terms of nutrients and the ability of the rice flour to be incorporated in food production led to this study where we determined the chemical composition, water solubility index (WSI) and water absorbability index (WAI) of five different raw and cooked traditional rice varieties named Kaluheenati, Suwadel, Mavee, Masuran, and Gonabaru. Rice was cooked as per home cooking. Raw and cooked flour were obtained after drying and milling. All the analyses were carried out according to standard methods (n=6). Significances were analyzed at 95% confidence interval. Among the analyzed traditional rice varieties, digestible starch (DS) content was prominent and ranged between 71-79% in raw and 77-84% in cooked rice. Mavee contained the highest DS content (83.7%) after cooking which had significantly increased from raw rice (70.7%). Crude fat and crude protein of cooked rice ranged between 4-6% and 5-10% while in raw rice the values were 45% and 6-9% respectively. Fat content of Masuran (6%) and Suwadel (4.6%) were significantly high in cooked and raw rice respectively. According to the results, majority of studied raw or cooked traditional rice are a good source of protein with Suwadel (9.5%) and Mavee (9.2%) having significantly high protein contents among the tested cooked varieties. WSI of all raw (2-5%) and cooked rice (4-9%) were low. However, the WAI ranged between 98-146% in raw rice and 192-236% of cooked rice. Highest WAI were found in Suwadel (236%) followed by Mavee (228%) both of which contained high protein. Cooking has increased the DS content, protein and WAI of rice flour when compared to raw rice flour.
Joint probability distribution of daily maximum and minimum temperature data: A copula based approach
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Abraj, M.; Hewaarachchi, A. P.
The analysis of extreme daily temperature is crucial for crop production, public health development, weather predictions and decision making processes. This study examines the joint distribution of daily maximum (Tmax) and daily minimum (Tmin) temperature. For this study, daily Tmax and Tmin temperature data, measured at the Hambantota Meteorological station from January 2012 to December 2017 are used. To test the correlation, Kendall’s tau rank correlation test is used and a significant correlation (p-value < 0.05) is observed between daily Tmax and Tmin. Copula method is then used to model the dependence between Tmax and Tmin. Five candidates of univariate distributions are employed to model Tmax and Tmin separately. The parameters are estimated using the maximum likelihood method, consequently the best fitted distributions are identified based on Akaike Information Criterion (AIC) and Bayesian Information Criterion (BIC). It is identified that Normal distribution (µ=31, 𝜎=1.5) is the best fitted univariate distribution for daily Tmax and Weibull distribution (Shape=23.3, Scale=25.6) is the best fitted univariate distribution for daily Tmin. The best fitted univariate distributions are then used to fit Frank, Clayton, Gaussian, and Gumbel Copulas. The best fitted Copula is identified based on the minimum values of AIC and BIC. To validate the best fitted Copula model, cross validation Copula Information Criterion is used. It is determined that Gaussian Copula is the best to model the dependence between daily Tmax and Tmin in Hambantota.
Effect of dehydration temperature, time and blanching methods on the sensory properties of an herbal tea developed from Moringa oleifera leaves
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Wickramasinghe, W.Y H.,; Wickramasinghe, I.; Ariyasinghe, H. A. E. N.; Wijesekara, I.
Moringa oleifera is a highly nutritious plant which can be used as a good source of nutrition and leaves have been found to contain high amounts of vitamins, minerals, proteins and fiber. The main objective of this study is to explore the use of Moringa oleifera leaves, to produce an herbal tea with acceptable sensory properties, by using different dehydration temperatures, time and blanching methods which can be used in the Sri Lankan market. According to AOAC procedures the initial moisture content (%) of fresh leaves was found to be 78.17 ± 1.57 (dry basis). Six sets of samples were prepared where temperature and time combinations were; 600C 4 h 30 min, 650C 3 h, 550C 6 h for unblanched samples and; 600C 5 h 30 min, 650C 4 h and 550C 6 h for the steam blanched samples. The gross yields of the dried leaves to its initial weights were 22.86%, 20.88%, 23.62%, 19.18%, 15.21% and 14.97% respectively. The moisture content of the dried leaves ranged from 2.09±0.17 to 5.36±0.06. The colour values L*, a*, b* ranged from 16.83 ± 3.02 to 30.2 ± 3.32, -1.93 ± 0.46 to - 6.41 ± 0.79 and 5.1 ± 1.29 to 15.49 ± 1.29 respectively. These samples were given to a trained panel of tea tasters for the sensory evaluation and sample 5 (steam blanched, 650C 4 h) was selected as the sample with the best sensory attributes. These samples were evaluated using a 5-point hedonic scale, by a semi-trained panel of 35 assessors and data were analyzed using the MINITAB statistical package using Friedman test. According to the statistical analysis, sample 5 showed the highest score. The brew of unblanched leaves was giving harsh unpleasant characters whereas the steam blanched samples were giving a pleasant taste.
Isolation and identification of thermophilic bacteria and cyanobacteria from Maha Oya hot springs in Sri Lanka
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Medhavi, P.I.H.R.; Samarasinghe, D.G.S.N.; Herath, H.
Hot springs are a rich source of thermophilic microorganisms such as bacteria, cyanobacteria and archaea. Though, there are several hot springs recorded in Sri Lanka, a comprehensive community analysis of thermophilic microorganisms in these springs is inadequate. Therefore, the present study was conducted to isolate and identify the thermophilic bacterial and cyanobacterial diversity in Maha Oya hot springs. Water samples were collected from the surface and the bottom of the seven wells of Maha Oya hot water springs, which showed temperatures ranging from 42 to 59.80C and pH ranging from 6.89-7.63. Water samples treated with Lugol’s iodine as well as microbial mats growing on water surface and attached to the surface of wells, were observed under a light microscope to determine the presence of cyanobacteria. Thermophilic bacteria were isolated by inoculating a dilution series (100, 10-2 and 10-4) of water samples separately into nutrient agar medium and incubating at 550C for 48 hours. Water and microbial mat samples were inoculated into cyano-specific BG11 and BG110 media and incubated at 550C and 12:12 hours dark:light cycle to isolate culturable thermophilic cyanobacteria. Based on morphological (colony morphology, Gram staining, endospore staining and motility test) and biochemical (oxidase activity, catalase activity, H2S production, citrate utilization, glucose fermentation) characteristics, the isolated bacteria were identified as Bacillus thermoamylovorans, Meiothermus sp. and Bacillus schlegelii which have been previously reported as thermophiles. Morphological identification of both uncultured and cultured cyanobacteria revealed the presence of eight different cyanobacterial genera. The most abundant genus was Oscillatoria . Additionally, Calothrix, Synechococcus, Gloeocapsa, Gloeothece, Cylindrospermopsis, Lyngbya and Pseudanabaena were observed. The isolation and identification of these thermophiles could be useful in mass scale production of thermostable enzymes and other bioactive compounds with biotechnological and industrial applications.
Mobile solution for color blindness - An application of image processing
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Thanusanth, B.; Jeewanie, J. A.
Color blindness is a deficiency of color vision which mostly appear as a genetic problem. Due to presence of color blindness, human eye becomes unable to differentiate colors from other colors. People who suffer from the color blindness fully or partially have trouble in differentiating certain colors, but the severity of the color deficiency is varying. Sometimes damage of an eye or disorder of eye and brain are also cause to color blindness. The people suffers from color blindness wear suitable spectacles to overcome the deficiency. There are some scientific studies currently going on to address this problem. They can be classified as computer aided solutions and non-computer aided solutions. On the non-computer aided side, there is just one technique used: colored filters. These filters come in different forms such as Lenses, Glasses, etc. In the Computer aided side, there are different tools available such as Ishihara Test, Farnsworth Lantern Test. In the modern world, people always carry many smart solutions with their mobile phones in their hands and many services available to them with a single touch. For example, weather information, train time table, alerts about important meetings etc. By following a design science research methodology, this research is to study the techniques for color blindness and, implement an algorithm to detect the color ranges using Convolution matrix. The main artifacts are algorithm and mobile application. The results are twofold. On one hand, the proposed solution is very useful for those who don’t like to wear spectacles or if they forget to bring the spectacles every time. On the other hand, there are some people who are still not aware about their color blindness. For them, the mobile application can be used to identify their color blindness. Images are captured using the camera of the mobile phone and they are matched with the RGB range for colorblindness. Basically image processing techniques are used to implement the solution. The Convolution Matrix class is used to sharpening the image when mapping. This mobile application has facilities to check the different colorblindness and also a test for colorblindness. The proposed solution is validated with a sample of 25 users.
Isolation of Salmonella spp. and Shigella spp. from ground and surface water in the lower part of the Kelani river basin: evaluation of resistance against selected antibiotics
(2018) Abinaiyan, I.; Mahagamage, M.G.Y.L.; Manage, P.M.
In recent years, greater attention has been paid by national and international agencies on microbial contamination of ground and surface water sources. Antibiotics are commonly used to treat emerging infectious diseases due to anthropological activities. Improper application of antibiotics both in human and animal therapy has become the main cause of antibiotic resistance. The Kelani River Basin (KRB) is the home to more than 25% of the Sri Lankan population and it provides about 80% of the drinking water to Greater Colombo. Thus, evaluation of the microbiological status along with antibiotic resistance is important to safeguard consumers within the KRB. Therefore, twenty ground and twenty surface water samples were collected from a lower part of KRB for the study during March 2018. Water temperature, Dissolved Oxygen (DO), pH and conductivity were measured at the site itself using standard meters and N-NO3−, N-NO2−, N-NH3, Total Phosphate (TP), COD and Total Hardness (TH) were measured by following standard spectrophotometric and titrimetric methods. Total Coliform (TC) and Fecal Coliform (FC) counts were obtained from membrane filtration methods where Salmonella spp. and Shigella spp. were isolated and identified according to the WHO standard protocol. Antibiotic resistance of the isolated Salmonella spp. and Shigella spp. were obtained using Antibiotic Susceptibility Test (AST) following Agar Disk Diffusion Method (ADDM) for some selected antibiotics by commercially available AST disk. Resistant strains were subjected to Broth Microdilution Assay (BMA) to find Minimum Inhibition Concentration (MIC). All the tested general water quality parameters were within the SLSI drinking water standard except pH and COD. It was found that; out of 40 samples, 39 were contaminated with TC and FC and 39 samples exceeded the bacteriological standards given by SLSI drinking water standards. Salmonella spp. and Shigella spp. were recorded in a groundwater sample located in Pattipola where poor sanitation practices were observed. Another sampling location in Kanampella, Shigella spp. was recorded. AST results of the study revealed that the Salmonella spp. and Shigella spp. were resistant to 10 µg/disk of Amoxicillin (AMX) and Ampicillin (AMP). The BMA indicates that MICs of the isolated strains against AMX and AMP were up to 70 µg/mL. Accordingly, treatment, awareness and strategic management plan is a must to safeguard both ground and surface water consumers in the lower part of the KRB.
The impact of employer - employee relationship and practice of effective goal setting on employee performance: A study on millennial employees in small and medium scale IT organisations in Sri Lanka
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Wickramasena, R. D. G. K.; Tharaka, V. K.
This research study has been conducted to investigate the effect of two human resource management (HRM) practices on employee performance. Goal setting and maintaining robust relationship with the employees are considered to be two important factors for any organisation to achieve desired level of performance. Information Technology (IT) industry is a booming industry in Sri Lanka, and the majority of the employees who are working in Sri Lankan IT organisations are millennials. There are many studies conducted on the factors that affect the employee performance and the impact of each factor on the organisational performance. But there are no sufficient studies conducted to explore the impact of the practice of effective goal setting and employer-employee relationship on employee performance. Hence, this research investigates the effect of the practice of effective goal setting and employer-employee relationship on employee performance, in small and medium scale IT organisations in Sri Lanka. Since the higher proportion of IT workforce in Sri Lanka belongs to millennial category, this study provides thorough information for the industry, in order to achieve optimal level of employee performance. The primary data on employee performance, practice of effective goal setting and employer-employee relationship were collected through questionnaires. Out of a population of 90,000 employees, 300 employees who met the criteria have been chosen as the sample. The data analysis method used is Structural Equation Modelling (SEM) method. This study examines that there is a positive and significant influence collectively and individually of the practice of effective goal setting and employer- employee relationship on employee performance. Apart from these results, it further elaborates on the extent of the influence that practice of effective goal setting and employer-employee relationship portrays on employee performance and how the management should focus on these factors.
Effect of feeding herbal enriched Artemia on the growth performance and stress resistance of guppy fry (Poecilia reticulata)
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Sandamali, L.; Kumudu, R.; Sajani, R.M.
Artemia is one of the commonly used live-feed in hatchery production in aquaculture industry. The nutrient composition of Artemia can be enhanced by bioencapsulation using various sources. The present study was conducted to evaluate the growth performance and stress resistance of guppy fry (Poecilia reticulata) fed on Artemia enriched with different herbal ingredients ie: green kankung (Ipomoea aquatica) or carrot (Daucus carota). Herbal ingredients were mixed with oil to make the enrichment solution and ІІ instar stage of Artemia (36 hr after hatching) was used for the enrichment. Two days old guppy fry was fed with unenriched Artemia (UE), Artemia enriched with carrot juice (CJ) or Artemia enriched with kankung powder (KP) for 21 days and the growth, survival and stress resistance of fry were evaluated. These comparisons were tested using one-way ANOVA. After a feeding trial of 21 days, the total length was significantly higher in fry in CJ treatment (14.59 ± 0.84 mm) followed by fry in KP treatment (13.83 ± 0.16 mm) and fry in UE treatment (12.14 ± 0.83 mm). Fry fed on CJ and KP enriched Artemia showed higher mean final weight (0.0279 ± 0.0048 g, 0.0263 ± 0.0012 g) and % Specific Growth Rate (SGR) (6.98 ± 0.063, 6.39 ± 0.99) respectively compared to the fry fed on unenriched Artemia (0.0167 ± 0.009 g, 4.64 ± 0.064 g). Fry in all treatments showed 100% survival rate by the end of the experiment period (21 days) and were subjected to stress resistance test. Cumulative Mortality Index (CMI) for salinity stress test was significantly different in the three treatments. Highest CMI (960) value, therefore lower salinity resistance was observed in the fry fed with KP enriched Artemia, and the lowest CMI (0) value and the highest salinity resistance was observed in fry in CJ treatment group. Further fry in CJ (CMI 400) and KP (CMI 320) treatments showed higher thermal resistance compared to fry in UE treatment (CMI 720). The present study reveals that Artemia enrichment using carrot juice can be used to enhance growth and stress resistance of guppy fry in aquarium condition.
Optimal parameter values for Respondent-Driven Sampling
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Kularathna, N. J.; Ramanayake, K. P. A.
Respondent Driven Sampling (RDS) is a new link tracing sampling technique which is used to collect data from hard to reach or hidden populations such as sex workers, HIV infected people, homeless people, etc. In RDS, individuals recruit other individuals through their social networks. The major benefit of RDS among other link tracing methods is that it achieves a probabilistic sample with known selection probabilities. Deciding on the number of seeds, coupons and waves are crucial prior to implementing a RDS study. However, since there are no universally accepted values for these parameters in RDS, they need to be determined based on the study. This research focused on finding optimal number of seeds, coupons and waves that give the highest level of accuracy for RDS estimates when all the parameters are free to change simultaneously. A publicly available partial dataset from Project 90, Colorado Spring study was used as the population. The simulation study used the most frequently used sets of values for the number of seeds, coupons and waves based on literature. As a result, 125 combinations of seeds, coupons and waves were formed and for each such combination, 1000 resamples were drawn from the population. The successive sampling estimator was used in this study to estimate the population parameters as it has been shown that it substantively outperforms all other estimators in RDS. The simulation results revealed that the estimated values converge to the true parameter value as the number of seeds and the number of waves increase and when the number of coupons decrease (up to 2). Once the sample size and the number of seeds have been determined, the proposed simulation process can be used to find the optimal number of coupons which gives the highest accuracy for any considered population characteristic.
Screening of selected invasive plant extracts for antifungal activity against Colletotrichum gloeosporioides
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Karunarathna, T.C.M.F.; Damunupola, J.W.; Bandara, B. M. R.
High-quality ornamental plant products are needed for export-scale floriculture. A major barrier to provide high quality products is the wide prevalence of plant pathogenic diseases. Colletotrichum gloeosporioides causes diseases in several species of ornamental plants. Use of chemical fungicides can cause undesirable non-target effects and fungal resistance. The invasive plants that threat natural ecosystems, may serve as an inexpensive source for developing antifungal products that are devoid of the problems associated with synthetic fungicides. We examined the antifungal activity of 36 extracts (6 plants x 2 plant parts x 3 extract solvents) of 6 invasive plants, Mikania micrantha, Tithonia diversifolia, Lantana camara, Clusia rosea, Chromolaena odorata and Clidemia hirta against the pathogenic fungus C. gloeosporioides that was isolated from Dracaena reflexa leaf spots. PCR and sequencing for molecular characterization of the fungus was done at Genetech, Colombo. All the invasive plants were collected from the Central Province, Sri Lanka. Plants were washed, air-dried and powdered. Each powder was sequentially extracted into n-hexane, dichloromethane (DCM) and methanol at room temperature (RT) for 30 min using an ultrasonicator (40 kHz). Removal of solvents on a rotary evaporator gave the respective plant extracts. Each plant extract (2 mg/disc) was screened for antifungal activity against C . gloeosporioides using disc diffusion method by incubating for 3-5 days at RT . Standard fungicides mancozeb and propineb (50 µg/disc) served as positive controls. All assays were carried out in triplicate and repeated thrice in completely randomized design. The areas of inhibition were measured and analyzed using one-way ANOVA with Minitab 16 . The extracts of M . micrantha, T . diversifolia, C . odorata, L . camara and C . hirta showed varying degrees of antifungal activity against C . gloeosporioides while the extracts of C . rosea were inactive. The DCM leaf extract of M . micrantha (3.42 ± 0.34 cm2) and the DCM root extract of T . diversifolia (2.26 ± 0.24 cm2) displayed the highest area of inhibition; while mancozeb and propineb were 2.17 ± 0.14 and 1.29 ± 0.06 cm2, respectively. M . micrantha leaves and T . diversifolia roots could be potential sources for developing plant-based fungicides to be used in floriculture industry.
Investigation of some water quality parameters in the ground water of East and Central regions of Valigamam Zone in Jaffna Peninsula
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Navaranjan, S.; Prabagar, S.; Rajapaksha, H. G. N.; Prabagar, J.
Jaffna peninsula relies on ground water for their entire domestic and agricultural needs due to less rainfall and not any other fresh water resources. In recent years many complaints have been received indicating that ground water is unsuitable for human consumption. Increased levels of certain ions such as calcium, nitrate in water deteriorate the quality of water and can cause serious health issues such as kidney diseases and blue baby syndrome. Thirty two water samples from domestic and agriculture wells were collected randomly from East and Central regions of Valigamam zone in Jaffna peninsula. The water quality parameters such as total dissolved solids, alkalinity, potassium, phosphate, sulfate, nitrate, calcium and magnesium were evaluated from December 2017 to March 2018. Phosphate, nitrate and sulfate were determined by multiparameter photometer using powder pillows, calcium and magnesium were determined by titration methods, total dissolved solids were determined by multiparameter and potassium by flame photometer. The results obtained were compared with the Sri Lankan standards for potable water – SLS 614:2013. It was found that about 62.5% of samples exceeded the standards (500 mg/L) in total dissolved solids. Alkalinity content of all the samples exceeded the Sri Lankan standards (400 mg/L). Sulfate content was higher in 12.5% samples compared to standard (250 mg/L). Manipay, Kopay and Inuvil areas showed high concentration in most of the ions compared to standards. These are the areas where agriculture was practiced throughout the year. High amount of calcium in ground water was observed in areas such as Kopay and Urumpirai. Calcium ions in water samples varied from 63.2 to 246.4 mg/L which shows an increase by about four fold within 16 years compared to studies in 2001. Elevated levels of nitrate content were found in Inuvil, Uduvil and some places in Kopay. A survey conducted among the farmers has shown that application of fertilizers in those areas were high. The nitrate content varied from 2.7 to 199.5 mg/L. 37.5% samples showed higher content of nitrate than the permissible level (50 mg/L) making them unsuitable for drinking purposes. The pH values of the water samples were within the range of 6.8 to 10.39 indicating slight alkalinity. The phosphate level varies from 0.18 to 3 mg/L in Kopay and 0.12 to 2.4 mg/L in Kondavil area. Compared to a study in 2013, the phosphate levels have increased in the study areas by three folds. The present study suggests that water quality of groundwater in Valigamam zone has increased in the levels of nitrate, phosphates, sulfate and calcium. Agriculture practices impact on the water quality parameters and use of fertilizers in agriculture should be minimized in Valigamam area.
Comparing the performance of randomization tests and classical non-parametric tests
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Hapuarachchi, H. T. S.; Magalle, C. H.
In the present world of data, there are plenty of instances where data does not adhere to the parametric assumptions. However, with the development of technology and computational facilities, Randomization Tests have become a popular alternative for these situations. Randomization tests also does not make any distributional assumptions but differ from classical non- parametric tests in many aspects. In this study, Wilcoxon Signed Rank test for both one sample and paired samples, Mann-Whitney test, Kruskal-Wallis test and Friedman test are being compared with respective Randomization Tests. The performance of the tests is compared for various sample sizes where 30 being the maximum sample size since the non-parametric tests are more useful when sample size is less than 30 and different variance conditions as well. The tests are compared for both skewed and symmetrically distributed data. Exponential and Gamma distributed data were generated as skewed data while Uniform and Normal distributed data are generated for symmetric data. The tests are being compared using type 1 error and power. Data were simulated using R software under each case and performed both tests for the same sample of data and obtained their type 1 error and power. Through this study, many cases were identified where randomization tests is more reliable than classical non- parametric tests in terms of type 1 error. For two skewed distributed unbalanced samples with heterogeneous variances, randomization tests are reliable since their type 1 error was around the pre-defined level while Mann-Whitey test is not reliable. Further, it could be found that randomization test is capable of protecting the type 1 error than Kruskal-Wallis test for large samples of non-normal symmetric and exponentially distributed data with heterogeneous variances. There were several situations of Friedman test performing meagerly than randomization test in terms of type 1 error. When considering the power values of the tests, randomization tests show almost equal robustness with classical non-parametric tests in most of the cases. However, for large sample sizes, randomization test has high power than Wilcoxon Signed Rank test (one sample). Moreover, when data are non-normal but symmetrically distributed, randomization test is more powerful than Kruskal-Wallis test according to the type 1 error. For symmetric data, randomization test is more powerful than Friedman test in both heterogeneous and homogenous samples. Hence, it is necessary to apply the two tests carefully as described in this study for more accurate analysis of data.
Optimization of monoplex and multiplex PCR assays to detect meat species and adulteration of meat products in the Sri Lankan market
(Research Symposium on Pure and Applied Sciences, 2018 Faculty of Science, University of Kelaniya, Sri Lanka, 2018) Kothalawala, S. D.; Karaliyadda, S.; Fernando, A. L.; Karaliyadda, M.; De Silva, V.
Meat identification testing, detecting intentional adulteration of meat and detecting meat contamination due to poor processing practices are essential to ensure good quality of meat products. Incidence of meat adulteration, product mislabelling, commercially motivated adulteration and contamination of meat products with undesired or forbidden meat species have been reported in some countries. In Sri Lanka, religious and cultural views are one of the primary determinants of choice of meat consumed. Therefore, the necessity for a rapid, sensitive reliable and reasonably cost effective assay that can determine the quality of meat products is high. Even though this need exists, no such reachable methods are currently available to the Sri Lankan meat producers to determine and certify the quality of their products. PCR based DNA methods are the gold standard in food species identification due to its less time consumption, specificity and sensitivity. The present study optimized monoplex and multiplex PCR assays to detect the meat species and to detect any adulterants or contaminants present in meat products. DNA was isolated by high salt TNES extraction method, from samples of raw meat and processed meat obtained from retail outlets in Colombo. The isolated DNA was amplified using PCR which demonstrated the specificity of the adopted primers to each species of raw meat. Mixtures of meat DNA were then subjected to optimized multiplex PCR; chicken-pork and beef-pork assays to detect each of the types of meat present in the mixture. Processed products of chicken (5) and beef samples (5) were subjected to these optimized multiplexes. The assay was found to be effective in determining the species of meat present in meat products containing chicken, beef and pork, clearly demonstrating species specific bands of 266 bp, 271 bp and 149 bp respectively. These PCR assays are useful in detecting main products and the contamination at the same time with reliable accuracy and specificity which can fulfil the requirement of quality testing of meat products that is important for the consumer, the meat industry and organizations that have an interest in food safety and quality. It is also economical and has wider applicability since many species can be detected with one assay. Compared to other available methods which sometimes fail to be effective when used on highly processed samples, PCR can be applied efficiently. Therefore, it is presented as a suitable assay for identification of meat species and for the detection of adulterants and contaminants in processed meat samples.