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A comparative assessment of knowledge of dental students on management of traumatic dental injuries, with and without access to the visual dental trauma guide
(University of Peradeniya, 2019-09-12) Senarath, N. H.; Wimalarathna, A. A. A. K.; Herath, E. M. U. C. K.; Fonseka, M. C. N.; Andersson, L.
Traumatic dental injuries (TDI) are a common finding which presents at 4.5% global incidence rate. These injuries significantly affect the quality of life of an individual due to the prominence of orofacial region in social and functional aspects of a life. Emergency management bears a critical value in the prognosis of traumatized tissues. Therefore, the general practitioners are expected to intervene appropriately. During the undergraduate practice the students are given lectures and demonstrations on TDI. However, having access to Visual Dental Trauma Guide (VDTG) as a tool to assist in making evidence- based decisions in the clinic is expected to be more effective. The objective was to evaluate the effect of using VDTG for diagnosis and treatment planning for TDI by dental undergraduates. Final year students in the test group were given access to the VDTG, during their clinical appointment, while the control group was not. Their knowledge was evaluated and compared using a multiple-choice questionnaire and OSCEs. The students with access to the VDTG were observed to be more knowledgeable in providing correct answers to three out of the seven OSCE questions. Evaluation based on the MCQs did not present a significant difference (p=0.913). However, Use of VDTG showed statistically significant difference in the overall knowledge of the test group based on their answers (p=0.028). In the test group 91.3% scored more than 50% for the MCQ paper while it was 95.7% in the control group. In the overall evaluation, 8.6% in the test group scored above 50% while it was 2.1% in the control group. Total mean value of the test group was 38.18 compared to 33.23 in the control group. Use of DTG is a valuable tool for better diagnosis and treatment of patients subjected to TDI. However, lectures and demonstrations have provided sound knowledge to the students.
A comparative study on ED-Cds and CBD-Cds thin films
(University of Peradeniya, Sri Lanka, 2016-11-05) Abeykoon, M.R.M.B.; Kumarage, W.G.C.; Dassanayake, B.S.
Among various deposition methods of CdS, chemical bath deposition (CBD) and electrochemical deposition (ED) standout due its simplicity, low cost along with uniformity of the fabricated samples. In this work CdS thin films are fabricated using CBD (CBD-CdS) and ED (ED-CdS) methods and compared using XRD, SEM, UV-visible spectroscopy and photoelectrochemical cell (PEC) measurements. All samples were deposited on thoroughly cleaned fluorine doped tin oxide (FTO) glasses. CBD-CdS was fabricated using, 0.001 M CdSO₄, 0.002 M CS(NH₂)₂ and 1.1 ml of NH₄OH at a bath temperature of 80 °C for one hour. ED-CdS was deposited by three electrode cathodic electrodeposition in an aqueous solution of 0.05 M CdCl₂, 0.05 M Na₂S₂O₃ at -600 mV against the Ag/AgCl electrode, at a bath temperature of 60 °C and a pH between1-2. All fabricated films were air annealed at 200 °C for 1 hour. The XRD analysis shows that the fabricated ED-CdS and CBD-CdS are predominantly hexagonal. The SEM images of the ED-CdS samples indicate that the surfaces of the fabricated films containing spherical features with various sizes. ED-CdS indicate more uniform coagulates compared to that of CBD-CdS. Hence, it is expected that the electrochemical deposition gives better packing, higher uniformity and better contact with the FTO, resulting in higher ISC for ED-CdS. The flat band potential value calculated form the Mott-Schottky plot was found to be -683 mV vs. Ag/AgCl for the ED-CdS and -533 mV vs. Ag/AgCl for the CBD-CdS, suggesting the existence of different electron affinity levels of CdS depending on the deposition method. The average transmittance of fabricated CBD-CdS and ED-CdS films were found to be 75% and 51% respectively. It can be concluded that the opto-electrical properties of CdS thin films are dependent on deposition method and ED-CdS show superior electrical properties compared to CBD-CdS.
A complete pipeline of free bioinformatics tools for de novo transcriptome assembly and SSR primer design
(University of Peradeniya, 2019-09-12) Naranpanawa, D. N. U.; Chandrasekara, C. H. W. M. R. B.; Bandaranayake, P. C. G.; Bandaranayake, A. U.
During the past few decades, next-generation sequencing technologies have grown exponentially in terms of throughput, speed and reduction of sequencing cost. This has revolutionized the field of genomics, allowing the production of vast datasets. However, methods and software requirements for analyzing this data to interpret correct biological meaning are not experiencing the same growth rate. One such limitation is the unaffordable price of commercially available bioinformatics software. Hence, only a small fraction of genomes and transcriptomes have been completely assembled and annotated. Lack of reference genomes for comparative assembly lead to computationally more challenging de novo assembly. In addition, obtaining an assembly is a complex process that require many steps by using several complex tools. Due to this, beginners in bioinformatics might find analysis procedures too complicated and time-consuming with the associated learning-curve. Therefore, in order to aid novice biologists in assembling sequence data, and to bridge the bottleneck in computational biology and bioinformatics, we present a complete pipeline of freely available bioinformatics software for de novo transcriptome assembly. This pipeline was developed by combining several individual software through user-friendly shell scripts. To test the pipeline, we used Illumina HiSeq paired-end RNA-seq reads from four oil-producing Santalum album (sandalwood) tree samples from a published study. The raw data were first filtered for low quality reads, trimmed for adapters and normalized. Assembly was performed with Trinity de novo assembler. The quality of the assembly was tested with BUSCO, Bowtie2 and TransRate, and indicated to be high quality. In order to further validate the accuracy of the assembly, we used the assembled transcriptome to identify gene-specific Simple Sequence Repeat (SSR) markers. Primers were designed for eight S. album oil biosynthetic genes and two control genes, which were validated in the laboratory with respective samples. All primers amplified successfully, confirming the designed workflow. Furthermore, five SSR markers polymorphic among tested sandalwood accessions are potential markers to be utilized in sandalwood breeding programs. To the best of our knowledge, this is the first attempt of developing a user-friendly, validated assembly pipeline with free bioinformatics software and tools, provided with detailed documentation.
A critical evaluation of the ownership and responsibilities of early childhood care, development and education in Sri Lanka
(University of Peradeniya, 2019-09-12) Abesooriya, L.
Early Childhood Care and Development and Education are considered crucial for human development (UNICEF, 2007 cited in Gallardo, 2009). The dearth of research in Early Childhood Care and Development (ECCD) and education indicate that less attention is paid to its advancement in Sri Lanka. Furthermore, the child related studies conducted in Sri Lanka are limited. This paper presents a critical evaluation of the policies related to the ownership and responsibilities of ECCD and education in Sri Lanka. A qualitative research design was used for this study. Interviews were done with responsible informants at the Children’s Secretariat and Provincial Councils. Furthermore, documents related to ECCD and education were analysed using thematic analysis in order to discover the emerging themes related to the policies of ECCD and education. The findings showed that there is no single designated authority who is responsible in maintaining the early childhood care and education in Sri Lanka. Furthermore, it was noted that the responsibility of ECCD and education constantly shifts from one authority to another. In addition, the contradictions in the policies regarding the responsibilities and ownership was noted. Hence, the requirement for stern and stable policies to establish authorities to maintain and also to share the responsibilities regarding the early childhood development and care and education is highlighted in the present study.
A deep learning approach to increase the accuracy of predicting protein- compound interactions
(University of Peradeniya, 2019-09-12) Gunathilake, P. M. P. C.; Roshan, W. M. P. G. D. M.; Jayarathna, P. D. C. R.
In drug repositioning and discovery, a system-level identification of drug-target direct interactions is important. However, even today a wide range of drug compounds and protein targets makes it challenging and expensive to identify the interactions between them. For protein-compound interaction prediction, traditional similarity-based computational models were used and they rarely utilize the hidden features from currently available large-scale unlabelled compound and protein data. They often limit their usage on relatively small-scale datasets. This work proposes a new schema for predicting the protein compound interaction and binding score using deep learning approach. Most accurate features from a large set of proteins and compounds were selected and converted into a form of numerical values as the input data. The known interactions between selected compound and protein pairs were taken in binary form as the target dataset. The numerical input dataset and the binary target dataset were used to train a deep neural network model under a supervised learning process. The neural network was optimized and trained with different activation functions and optimization algorithms. The trained neural network model was then used to predict the protein-compound interactions. Also, the second approach was made to predict the protein-compound binding score. The same set of protein-compound pairs were selected as the input of the neural network model. A multiple levels of numerical values representing the binding score between each protein- compound pair in the input dataset was taken as the target instead of the binary target in the interaction prediction method. Then the neural network model was optimized and trained to predict the binding score for a protein-compound pair. The cross validated accuracy for protein-compound binding score prediction neural network was 99.6% and for the protein-compound interaction prediction neural network it was 77.32%.
A high throughput molecular marker assay for bacterial leaf blight resistance gene Xa21 in rice
(University of Peradeniya, 2019-09-12) Nanayakkara, N. H. L. D. L. D.; Edirisingha, I. K.; Dissanayake, D. M. L. N. K.; Weerasinghe, W. D. P.; Suriyagoda, L. D. B.; Herath4, H. M. V. G.; Perera, S. A. C. N.; Jayatilake, D. V.
Molecular markers are used as tools for precise and efficient screening of desirable genotypes in modern day plant breeding. One of the attractive attributes of a molecular marker is its compatibility to high throughput screening. The Xa21 gene is a major resistance gene against bacterial leaf blight (BLB) caused by Xanthomonas oryzae pv. oryzae. The closely-linked sequence-tagged site marker pTA248 has been frequently used for the screening of Xa21, however, compared to a flanking or intergenic marker, a linked-marker may have low reliability and effectiveness in marker-assisted selection (MAS). In the current study, a diagnostic intragenic marker ABUOP0001 was developed for MAS of Xa21, which flanks over a 19-bp insertion/deletion on the ectodomain of the Xa21. The marker amplifies a 200-bp and a 181-bp amplicon from the rice lines IRBB 62 and IRBB 7, known-to-carry the resistance and susceptible alleles for Xa21, respectively. The marker ABUOP0001 is compatible for high-throughput screening with high resolution melting technology, where the genotypic scoring could be effectively carried out based on the normalized melt curves. Further, the marker ABUOP0001 was successfully assayed as a single-tube multiplexed PCR with another molecular marker assaying for the BLB resistance gene Xa4. The products of the two markers can be effectively binned together to facilitate the detection of the presence of resistance and/or susceptible alleles in a single PCR reaction. The marker ABUOP0001 performed equally or better than the linked-marker pTA248 in detecting BLB resistant phenotypes in a field trial involving 63 rice accessions. Therefore, the marker ABUOP0001 can be recommended as a diagnostic intragenic marker for marker-assisted high throughput screening of Xa21 in rice.
A multispectral imaging system for industrial applications
(University of Peradeniya, Sri Lanka, 2019-09-12) Prabhath, G. W. K.; Bandara, W. G. C.; Dissanayake, D. W. S. C. B.; Herath, H. M. V. R.; Godaliyadda, G. M. R. I.; Ekanayake, M. P. B.; Fernando, M. A. R. M.
Multi-spectral imaging (MSI) is a technique for obtaining spectral information of an object. MSI has rapidly evolved as a non-destructive and non-invasive analytical method in many industrial applications. Multispectral images are rich in information compared to the standard RGB images because they have the capability of acquiring spectral information beyond the RGB bands. Therefore, multispectral images can be used to classify object properties more accurately than an RGB image. However, commercially available multi-spectral cameras with high spectral resolution are very expensive and the implementation of such imaging system is not affordable for medium scale enterprises. In the first part of this research, we were designed an MSI system that can be customized for use in many industrial applications. The developed MSI system can capture multispectral images from near ultraviolet (N-UV) to near infrared (NIR) region of the electromagnetic spectrum with a spectral resolution of nine spectral bands (405 nm - 960 nm). The light emitted by the light emitting diodes reaches the object which is placed inside a dark chamber through an integrating hemisphere. The multi-spectral images of the object were captured using a monochrome camera with a resolution of 1.3M Pixels and saved for each flash. In the second part of this research, MSI system was used to estimate the leakage current through algae aided insulators used in high voltage (HV) transmission lines. The leakage current flows in HV transmission lines are mainly due to the algae contaminated insulators. Inspection of HV insulator conditions are done as visual inspection tasks. However, this process is expensive, time consuming and required skilled workers. The results show that use of MSI system for the condition assessment of HV insulators remotely. Additionally, a hybrid machine learning algorithm was developed based on principal component analysis (PCA) and multivariate statistical methods to estimate the leakage currents through algae aided ceramic plates.
A novel molecular marker for gel-based biotyping of fall armyworm (Spodoptera frugiperda)
(University of Peradeniya, 2019-09-12) Nanayakkara, N. H. L. D. L. D.; Denipitiyage, S. D.; Jayatilake, D. V.; Kodithuwakku, S. P.
The fall armyworm (FAW), Spodoptera frugipera is a Noctuid lepidopteran pest with a polyphagous feeding habit. The larval stage of FAW feeds on a wide range of crops, including major cereals and vegetables causing significant yield losses globally. The genetic complexities and their migration patterns have resulted two morphologically indistinguishable FAW subpopulations, named “rice strain” (R-FAW) and “corn strain” (C-FAW). Previously, sequence-based analysis, restriction enzyme-based profiles, and dominant marker assays targeting the mitochondrial cytochrome oxidase 1 (CO1) gene have been used to differentiate the biotypes. In the current study, we developed a gel- based co-dominant temperature-switch PCR (TSP) marker, targeting a single nucleotide polymorphism (SNP) for direct biotyping of FAW. To design the marker, reference CO1 gene sequences of R-FAW (Genbank accession: U72977) and C-FAW (Genbank accession: U72974) were retrieved from the NCBI repository. A 746 bp length sequence of the CO1 gene was aligned using ClustalW feature in Geneious v.7.1.3. The TSP marker was designed using the Primer3 platform on Geneious, with a pair of locus- specific primers defining the region of interest, and a pair of nested locus-specific primers targeting a SNP within the resulted amplicon. A sample each of R-FAW and a C-FAW biotypes (confirmed as the respective biotypes through direct DNA sequencing of the COI region and comparing with the FAW reference sequences) collected from Ridimaliyadda amplified the expected 341-bp amplicon, and a 204-bp amplicon, respectively, for the TSP marker assay. Thus, the newly developed TSP marker, named ABUOP0002 can be recommended as a gel-based molecular marker for the identification of FAW rice and corn biotypes. This marker can be used as a low-cost molecular tool to efficiently diagnose FAW biotypes without DNA sequencing especially in a resource- limited setting.
A preliminary study on impacts of Bambusa bambos spread in intermediate zone forests in Moragahakanda, Sri Lanka
(University of Peradeniya, Sri Lanka, 2016-11-05) Millangoda, M.G.U.A.; Madawala, H.M.S.P.
Bambusa bambos is native to Sri Lanka though it is a known invasive species elsewhere in the tropics. Some parts of the intermediate zone forests in Moragahakanda area (located in the Matale district) have been heavily invaded by B. bambos. The present study was carried out to identify some ecological impacts of this invasive spread in these forest ecosystems by comparing an invaded (INV) and an un-invaded (UNI) forest patch, located about 2 km apart from each other. The vegetation less than 1 m in height (hereafter will be known as ground vegetation) was enumerated using ten, randomly placed 1 m2 quadrats. Seedling richness, density, diversity and evenness values were calculated. Surface litter was quantified. Soil samples were analyzed for some basic soil parameters including pH, conductivity, moisture content, microbial biomass carbon, total nitrogen and phosphorus. The results were analyzed using Minitab 16.0 version. The ground vegetation in INV forests showed higher density and species richness compared to UNI forests. The Shannon-Wiener Diversity index (H') also showed a higher value in INV (2.77) than in UNI forests (2.03). The Pielou’s Evenness index also recorded a higher value at INV (0.82) compared to UNI (0.60). The abundance of tree saplings and seedlings was also higher in INV than in UNI forests. Species composition showed notable differences between INV and UNI forest patches, with only two species in common. Though the surface litter was dominated by Bambusa litter (≈ 86%) in INV forests, the total litter content did not differ significantly between the two forest patches. Soil analysis revealed significantly higher N, P and moisture contents in INV sites than in UNI. Microbial biomass C too showed higher values in invaded forests, though not significantly. The preliminary results suggest that Bambusa spread has changed the composition of the ground vegetation with a possibility of altering the standing vegetation over time. Bambusa spread seems to enhance the soil fertility status perhaps through higher litter turnover and its quality. The preliminary results suggest that the Bambusa spread has the potential to alter these intermediate zone forests unless measures are taken to control its spread.
A preliminary taxonomic survey of leafy liverworts from some selected localities of Sri Lanka
(University of Peradeniya, Sri Lanka, 2016-11-05) Samarakkody, S.P.; Ruklani, N.C.S.; Rubasinghe, S.C.K.
Bryophytes with a dominant haploid generation and a dependent sporophyte in their life cycle are the first group of plants that successfully colonized the terrestrial habitats. Bryophytes include three distinct groups based on the morphological heterogeneity of the gametophyte and these are currently included in three distinct phyla; Marchantiophyta (liverworts), Bryophyta (mosses) and Anthocerotophyta (hornworts). Sri Lankan leafy liverworts are very poorly researched with only a very few collections done by past foreign scientists. There are no proper taxonomic studies conducted on this group. Based on the most recent, revised checklist of Sri Lankan liverworts and hornworts, there are 25 families, 64 genera and 286 species of leafy liverworts. Therefore the objective of the present study was to carry out a preliminary taxonomic survey of the leafy liverworts present in Sri Lanka to initiate further taxonomic and systematic studies on this important plant group. Fresh specimens of leafy liverworts were collected from some selected localities including Dothalugala, Loolcondera, Hakgala, Sinharaja Forest Reserve, Trincomalee, Anuradhapura, Dambulla, Kantale, and Hortain Plains. The collected specimens were thoroughly surveyed for their macro and micro morphological and anatomical characteristics. Using the available keys, monographs and other taxonomic literature, the collected specimens were identified to generic and/or to species level. Taxonomic descriptions, illustrations and taxonomic keys were prepared for all the species identified. The present study identified a total of 14 families, 26 genera and 46 species of leafy liverworts with 3 new records in Sri Lanka; Heteroscyphus planus (Mitt.) Schiffn. (Lophocoleaceae), Drepanolejeunea tricornua Herzog. (Lejeuneaceae) and Cereatolejeunea cornuta (Lindenb.) Steph. (Lejeuneaceae). Leafy liverworts are highly diverse in their leaf arrangement, leaf lobe and lobules, under-leaves and also by various anatomical characters. Majority of the leafy liverworts encountered during the present study were epiphyllous and epiphytic. Identification of the taxa of leafy liverworts and explorations of their habitat diversity will emphasize the importance of conservation of these plants. Further field explorations should be carried out throughout the country to collect samples of leafy liverworts for detailed morphological and molecular studies.
A randomized clinical trial comparing the efficacy of decoctions of Rathkaralheba (Cyathullaprostrata) and Hathavariya (Asparagus racemosus) in the treatment of Sraviarshas (bleeding piles)
(University of Peradeniya, Sri Lanka, 2016-11-05) Dissanayake, D.P.A.; Sivaganesh, S.; Tissera, M.H.A.
In Sri Lanka, Ayurvedic physicians mostly recommend Rathkaralheba (Cyathulaprostrata) decoction as a common treatment for Sraviarshas and they tend to prescribe Hathavariya (Asparagus racemosus) mostly for bleeding disorders other than Sraviarshas. This study was planned to compare the effectiveness of these two medicinal plants in the treatment for Sraviarshas. One hundred patients with bleeding piles were randomly allocated into two groups. Patients of Group R were given Rathkaralheba decoction and Group H was given tuber of Hathavariya decoction while both groups were given thriphala tablets and a sitz bath according to Ayurvedic phenomenon. The duration of the treatment was two weeks. Eight clinical parameters relating to bleeding piles were monitored. Wilcoxon signed-rank test was used to compare bleeding and pain before and after treatment. In Group R, after treatment scores of bleeding frequency (Z= -5.976, p< 0.001), bleeding volume (Z= - 5.993, p<0.001), pain frequency (Z= -4.456, p< 0.001) and pain severity (Z= -4.462, p< 0.001) were significantly lower than before treatment scores. In group H, after treatment scores of bleeding frequency (Z= -5.789, p< 0.001), bleeding volume (Z= - 5.725, p<0.001), pain frequency (Z= -3.830, p< 0.001) and pain severity (Z= -3.872, p< 0.001) were significantly lower than before treatment scores. The Mann-Whitney test for comparison of two groups showed no significant differences between scores of after treatment in Group R and Group H in bleeding frequency (Z= -0.826, p=0.409), bleeding volume (Z= -0.871, p=0.384), pain frequency (Z= -0.370, p=0.712) and pain severity (Z= -0.663, p=0.508) With the results, it can be concluded that both treatment regimens are effective in reducing the symptoms of bleeding and pain of Sraviarshas and there was no significant difference of the effect of the two plants. Rathkaralheba and Hathavariya can be used similarly for the treatment of Sraviarshas.
A rare case of stomach perforation inside the thoracic cavity due to a congenital diaphragmatic hernia in an adult
(University of Peradeniya, 2016-11-05) Ranaweera, R.K.M.D.C.D.; Gamage, S.M.K.; Edirisinghe, E.M.D.B.; Wasala, W.M.A.K.O.; Udayakumara, E.A.D.
Congenital diaphragmatic hernia (CDH) is a defect that occurs due to abnormal development of the diaphragm, with herniation of the abdominal contents into the chest. We present an extremely rare case of perforation of stomach which has herniated through the diaphragm in an adult, causing pleural effusion and an empyema thorax. A 40 year old male presented with a three day history of left side chest pain and dyspeptic symptoms. His heart rate was 124 beats per minute, blood pressure was 110/70 mmHg and the respiratory rate was 28 breaths per minute. Air entry was low on the left side. The abdomen was tense but not tender. Urine output was less than 1ml/Kg/hr. A chest X-ray revealed a left side hydro-pneumothorax and so a tube thoracostomy was performed. Following the procedure the patient had intestinal contents draining through the tube. Urgent non-contrast computerized tomography (NCCT) of the thorax was performed. It revealed intestinal contents inside the left hemithorax with pleural effusion. The left lung has collapsed due to a massive pneumothorax with mediastinal shift. An urgent left thoracotomy was performed. The stomach, part of the omentum and spleen were herniated through postero- lateral (foramen of Bochdalek’s) diaphragmatic defect. A perforation of 1.5 cm was found on the anterior surface of the stomach with gross contamination of the left hemithorax. The lower lobe of the left lung has collapsed. The pleural cavity was washed thoroughly. Perforation was repaired with 2/0 PGA interrupted suturing. A midline laparotomy was performed on lateral position. A congenital defect of the diaphragm was identified and repaired with 2 Nylon interrupted. A thoracotomy was closed with chest drain in situ. The peritoneal cavity was washed and closed over a drain in supine position. A post-operative chest X-ray revealed fully expanded left lung with the left hemi diaphragm located in the normal position. He developed empyema of the thorax and had full thickness burst of the upper abdomen which was managed accordingly. The patient recovered and was discharged from the ward after 14 days of hospital stay. Although congenital diaphragmatic herniae are seen among children, presentation in adults is rare. Perforation of viscera in such a case is even a rare occurrence where a high degree of suspicion is required to identify and manage the condition. Standard thoracotomy with laparotomy on lateral position gives optimum exposure for surgery for such cases.
A review: fractionation methods of starch components (Amylose and Amylopectin) for industrial applications
(University of Peradeniya, Sri Lanka, 2019-09-12) Amaraweera, A. P. S. M.; Manipura, W. M. J. A. S. B.; Manamperi, W. A.; Gunathilake, C. A.
Starch is a natural polymer that can be used in industrial applications to prepare biodegradable artifacts. But these have many drawbacks such as high water absorption, low mechanical strength, and lesser durability. Properties of starch (chemical and physical) and that of the resultant applications are much dependent on the amylose to amylopectin ratio. Recent research studies have focused on fractionation of starch components and modifying the compositions of amylose and amylopectin for specific applications. Formulation of polymer blends with starch and various additives (cross linkers, plasticizers etc.) have led to significant improvements of properties in industrial applications such as plastics and composite material. This review mainly focuses on the recent developments in fractionation of starch using chemical, physical, and enzymatic methods. Of these, the physical and chemical fractionation methods are widely used, whereas enzymatic methods are used for highly specific applications. The main challenges of starch fractionation include high solubility and susceptibility to structural degradation. Recent studies have made significant progress in investigating various solvent mixtures and other process variables in order to overcome these challenges.
A robust technique to transform time series with missing data into a zero mean series
(University of Peradeniya, Sri Lanka, 2016-11-05) Adikaram, K.K.L.B.; Jayantha, P.A.
In the process of knowledge mining, feature scaling plays a crucial role. For feature scaling, there are two widely used methods in many machine learning algorithms, namely, mean normalization and standardization. In both these methods, mean is zero and consider only the dependent variable (y); no involvement of independent variable (x). Thus, regardless of the original regression, those approaches treat all the data as y = c series. However, when some data points are missing or removed (as outliers), the said approaches destroy the original regression. In this research, a novel standardization method to standardize data based on linear regression (y = mx + c) was introduced. The proposed transformation was given by ʸⁿᵉʷ ⁼ ʸᵀ ⁻ ᵡ ˣ ʸᵀ / ᵡᵀ+ c where ʸᵀ = ʸ ⁻ ʸᵣ, ᵡᵀ = ᵡ ⁻ ᵡᵣ, (ᵡᵣ,ʸᵣ) is any selected reference point, and c is any constant. The speciality of the proposed method is that the transformation used both independent and dependent variables. Thus, no influences form missing or removed data. When there were no noise or outliers, the new method transformed data into a y = c series even with multiple missing values. When c = 0, results showed that the transformation produces a zero mean series from any data set even with noise, outliers and missing values.
A stochastic approach to model traffic in a road network
(University of Peradeniya, Sri Lanka, 2016-11-05) Thalagoda, G.K.; Abeysundara, S.P.
Traffic congestion in the urban areas has become an unremitting problem faced by city planners. This phenomenon could result in adverse situations such as excessive fuel consumption, escalation in vehicle operating costs, time waste etc. Thus, it emphasizes the need for an efficient solution for the traffic scenario. Traffic scenarios have been extensively studied under diverse methodologies to predict when and where the traffic would appear. Stochastic methods such as Marko chains and Monte Carlo simulation produced fruitful results and are proven to be highly effective in terms of predictions along a segment of highway, freeway etc. However, a major drawback of these methods is the lack of feasibility when applied to the road networks in its entirety, due to the high complexity. This study attempted to introduce a new concept based on Markov models to overcome these drawbacks by mainly focusing on striking a balance between the route capacity and total surface area of vehicles of different vehicle types (motorcycles, cars, three-wheelers, buses and heavy vehicles). A road system with multiple junctions and lanes was considered and represented in matrix form. A separate matrix was assigned to each vehicle type to record the counts of each vehicle type that enters a road segment within short intervals of time. Thereafter, the total surface area of vehicles occupying each road segment was expressed as a proportion of road capacity. By repeating these steps several times on a given day, the traffic state transition for the given segment was estimated. Given the state of traffic for a road segment, these transition matrices can be used to identify the converging traffic state in the future. A road network with 7 junctions having 10 connecting two-way road segments was considered for the simulation study. For each vehicle type, the flow of traffic was assumed to follow a Poisson distribution with varying rates. Results showed that the proposed method worked as expected for different initial conditions of the traffic flow. Future studies would extend the proposed method by considering other criteria such as vehicles parked on either sides of the roadway, vehicle speed and weather conditions.
A stringent eco-labeling scheme to rule out greenwashing from Sri Lanka: suggestions for a legal framework
(University of Peradeniya, 2016-11-05) Karunawardhana, U.
As present day consumersare remarkably inclined to make their purchasing decisions based on the product’s impact on the environment, labeling goods and services according to ecological criteria has become a popular practice around the world. Hence, among manifold policies formulated in furtherance of sustainable development, eco-labeling or green labeling has seized much attention. However, an eco-label which merely green-washes a product could mislead consumers who intend to minimize the adverse environmental impacts by purchasing environmentally preferable alternatives, even at a high price.Specially, the absence of a nationally accredited eco-labeling scheme could trigger a tendency of using self-claimed eco- labels as a marketing trick to lure the environmentally conscious consumers to the greenwashed products. Therefore, in order to protect the consumers who are inclined to make their choices more on ecological grounds than on price signals, introducing a well-regulated eco-labeling scheme is of utmost importance. This qualitative research is basically aimed at understanding the concept of eco- labeling and its positive outcomes. Moreover, it highlights the dearth of a legal framework on eco-labeling in Sri Lanka and the significance of introducing a nationally accredited eco- labeling scheme which operates there under. Further, based on a comparative study on Germany, India, European Union and Singapore which have respectively brought up nationally/regionally accredited eco-labels such as Blue Angel, Eco-mark, and EU-Flower, suggestions for a legal framework are brought up in order to indicate reliable information on the environmental impact of a product to the consumer. Thus, the propensity towards greenwashing can be ruled out of Sri Lanka and foster its sustainable development.
A study of startup motives and entrepreneurship tendency among small business operators
(University of Peradeniya, 2019-09-12) Kahathuduwa, K.K.P.N.; Kodithuwakku, K.A.S.S.; Jayaweera, V.W.
A person’s propensity to engage in entrepreneurship has a relationship with his/her level of entrepreneurial tendency, and a person’s motivation to start-up business may defer from opportunity to necessity. This research primarily aims to assess start-up motives and entrepreneurial tendencies (ET) of small business operators in rural Sri Lanka. Data were collected using a structured questionnaire from a sample of 100 respondents. The motivation type of the business operator was decided using a list of structured questions and ET was calculated using the General Enterprising Tendency Test (GET) (Caird, 1991). The hypotheses were tested using Pairwise comparisons and Kruskal Wallis Test. Findings revealed that men were more opportunity driven whereas women were more necessity driven. However, both men and women were found to be motivated to fulfill personal needs. Furthermore, younger people are more opportunity driven compared to older people, and the respondents with a high level of formal education are more necessity driven. People owning older businesses are more opportunity-driven, also with higher ET scores whereas older people were more necessity driven and showed a lower level of ET scores. All in all, men demonstrated higher ET scores compared to women. Findings also revealed that the higher the level of formal education, the lower the ET scores. Even though some researchers argue that the personality traits (i.e. the construct of ET) of a given person are constant over the time, the findings of this research reveal that there are significant differences of the ET of groups of people belonging to different demographic and business characteristics. Furthermore, the ET also changed with the type of start-up motives, and vice versa. However, the findings also revealed that the influence of the type of startup motivation on ET is more significant than the influence of ET on the type of startup motives.
A study on prevalence of ischemic heart diseases among hypertensive patients participating at a hypertension clinic, teaching hospital, Peradeniya
(University of Peradeniya, 2019-09-12) Rathnayake, B. M. C.; Illeperuma, R. P.; Ralapanawa, U,; Jayalath, T. A.; Gunarathna, N. S.
Ischemic heart disease (IHD) is a leading cause of mortality in Sri Lanka. Potential risk factors remain unclear. Among the modifiable risk factors, hypertension is a critical offender. This study is aimed at assessing the risks for IHD among hypertensive patients. A descriptive cross-sectional study was carried out over 6 months, on 150 patients from the hypertension clinic of Teaching Hospital, Peradeniya. An interviewer administered questionnaire along with Rose Angina Questionnaire (RAQ) were used to collect data on potential risk factors of IHDs while 12 –lead ECG recordings were analyzed for ST segment alterations that mimic myocardial ischemic changes. Majority of participants were female (n= 93, 62%). The mean age of the sample was 61.5 ± 10.33 years and the average systolic, diastolic and mean arterial pressures were 146 ± 23.27Hgmm, 85 ± 12.08Hgmm and 104 ± 14.31Hgmm respectively. The association between the ST segment deviations that mimic IHDs and presence of stage I or II hypertension (n=52, 42%) was statistically significant (p<0.05, df=1). Both the responses to RAQ and ST segment analysis were positive among 34 (23%) with Odds Ratio of 1.35 (95% CI, 0.707 – 2.578), representing the high risk group for IHDs. Positive family history of IHDs (n=28, 19%) brings 1.838 (95% CI, 0.742 – 4.551) fold risk as evidenced by positive RAQ and ST segment deviations. The hypertensive individuals with diabetes (n=7, 7%) exhibited a 2.444 risk (95% CI, 0.648 – 9.224) while having both diabetes and hypercholesterolemia (n=18, 18%) indicated a 2.424 fold risk of developing IHDs, than those without such Non Communicable Diseases (NCDs). The conventional risk factors such as positive family history and the presence of concurrent NCDs were emphasized as risks for IHDs among hypertensive patients.
A theoretical analysis of securing LTE backhaul network using host identity protocol
(University of Peradeniya, Sri Lanka, 2016-11-05) Weliwita, C.S.; Karunarathne, S.N.; Sandirigama, M.
Long Term Evolution (LTE) is expected to provide end-to-end security with many other promising features. However, with unencrypted transmission in the backhaul network (network segment from evolved node B (eNB/eNodeB) to core network), end-to-end security guarantee is violated. Unlike in legacy standards, security standards for LTE do not specify backhaul security implementation and expects service providers to adapt backhaul security. Third Generation Partnership Project (3GPP) has recommended but not mandated implementing Internet Protocol Security (IPsec) with Internet Key Exchange v2 (IKEv2). Nevertheless, most vendors do not implement IPsec for on various reasons like implementation and maintenance cost, overhead, and lack of experience in security implementation. To assure end-to-end security, backhaul needs to be protected. In order to implement backhaul security, we proposed a new backhaul architecture using Host Identity Protocol (HIP) (HIP-LTE backhaul). HIP is capable of authenticating end nodes in the base exchange process and transmit Internet Protocol (IP) packets using Encapsulated Security Payload (ESP) transport mode by providing encryption and adding integrity protection as ESP – Bounded End to End Transmission (ESP-BEET) mode packets. A Security Gateway (SeGW) is used at the core network and backhaul network interface to work as one end node to reduce overload in HIP processing at core network nodes. eNBs and SeGW are the only nodes needed to implement HIP. We evaluated security of HIP-LTE backhaul network using analytical model based on ISO security architecture. In the study, we identified security mechanisms available and derived security services in HIP-LTE backhaul. Then we performed a compliance evaluation with 3GPP security requirements for LTE backhaul and found that all the security requirements are fulfilled by new architecture with additional security measures as resilience to DoS, MitM, Replay and flooding attacks. Thus HIP-LTE backhaul is capable of providing security in the backhaul segment without direct IPsec implementation. This reduces the operator effort to implement security in backhaul with less cost. HIP-LTE backhaul network can be used as an alternative in securing LTE backhaul networks.
Abundance and status of migratory water birds on Mandaitivu and adjacent areas in Jaffna, Sri Lanka
(University of Peradeniya, Sri Lanka, 2016-11-05) Rajkumar, P.; Wijesundara, C.S.
Migratory water birds are regularly present in the Jaffna peninsula from September to April. Previous studies on the status of migratory bird species in Jaffna are virtually lacking, mostly due to the insecurity of the area for three decades. As some of these species are rare and endangered, proper scientific studies are essential for their conservation. The objective of the present study was to evaluate the status of migratory water bird species on Mandaitivu and adjacent areas (i.e. Allaipiddy and Mankumban) in Jaffna. The study was carried out during three consecutive migratory seasons (September 2013 - April 2014; September 2014 - April 2015; September 2015 - April 2016). We used point counts for assessing abundance of birds. Each counting station was separated from the next by at least 250 m, to prevent double- counting. Binoculars (8 × 40) and a spotting scope (25 × 50) were used to observe birds. Peak counting hours were from 0630-1000 h and 1530-1800 h. Each count lasted for about 20 minutes. Each site was visited multiple times throughout the study period to allow for replication. Thirty two migratory water bird species in seven families were recorded from Mandaitivu, including one very rare and 10 uncommon/rare winter migrants. It is significant that the Greater Flamingo (Phoenicopterus roseus), an uncommon winter migrant, had the highest individual count (612) of any migratory bird species on Mandaitivu. From Allaipiddy, 21 migratory water bird species in five families, including one very rare and five uncommon/rare winter migrants, were recorded. The Bar-tailed Godwit (Limosa lapponica), a rare winter migrant, had the highest count of any migratory bird (1053) in the area. Eighteen migratory waterbird species in five families, including one very rare and four uncommon/rare winter migrants, were recorded from Mankumban. The Eurasian Wigeon (Anas penelope) and Brown-headed Gull (Chroicocephalus brunnicephalus) had the highest individual counts (4399 and 2102 respectively) of any migratory bird species in Mankumban. Of these, the Wigeon has been recorded very rarely until a few decades ago. Of the three sites, Mandaitivu showed the highest migratory water bird diversity with a Shannon Index of 2.48, while Mankumban ranked second with a Shannon Index of 1.25. Allaipiddy showed the lowest diversity (Shannon Index 0.971). Given the very high relative abundance of rare or uncommon migratory water bird species, we recommend that the wetlands in these areas be declared as internationally important waterfowl habitats.

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