ARS - 2005

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A family of solutions representing an accelerating Universe
(Proceedings of the Annual Research Symposium 2005-Faculty of Graduate Studies, University of Kelaniya, 2005) Rahubedda, U.S.; de Silva, Nalin
U.S. Rahubedda, Department of Physics, Nalin de Silva
A kinetic study on slow natural degradation of polycyclic aromatic hydrocarbons in Bolgoda Lake waters and a technique for rapid destruction of them in the aquatic environment
(Proceedings of the Annual Research Symposium 2005-Faculty of Graduate Studies, University of Kelaniya, 2005) Pathiratne, K.A.S.; de Silva, O.C.P.
Polycyclic aromatic hydrocarbons (PAHs) are unique environmental contaminants that exhibit strong toxic, carcinogenic and mutagenic properties. They are generated through incomplete combustion of organic matter such as fossil fuels (petrol, diesel, and natural gasses, etc.), wood and many other organic compounds used in variety of industrial and domestic processes. Once formed, they are adsorbed on to particulate matter and deposited on ground and in water bodies through continuous atmospheric fallouts. During rainy seasons, PAHs deposited on ground surfaces are washed into water bodies through surface runoff. A recent study revealed that water and sediment in Bolgoda lake to contain PAHs above safe levels. Further, the levels observed during dry seasons were found to increase after heavy rains, followed by gradual degradation during dry periods. As a part of the present investigation, the kinetics of degradations of four selected PAHs; naphthalene, phenanthrene, pyrene and chrysene (2, 3, 4 and 5 member ring compounds) found in Bolgoda lake were carried out. Four different environmental matrices given below (a) to (d): (a) Bolgoda lake water exposed continuously to incandescent radiation of a 60 W tungsten lamp at room temperature. (b) Bolgoda lake water kept in dark at room temperature. (c) Deionized water with pH and electrical conductivity (EC) adjusted to those of Bolgoda lake water, exposed continuously to incandescent radiation of 60 W tungsten lamp at room temperature (d). Deionized water with pH and EC adjusted to those of Bolgoda lake water, kept in dark at room temperature. These four different media could represent unique environmental components found in Bolgoda lake that could be responsible for degradations of PAHS in the Bolgoda lake. The results indicate that pseudo first order rate constants corresponding to degradations of all four PAHs in the four different media at room temperature decrease in the order a > b > c > d. Also, in all four media the order of the pseudo first order rate constants for degradations of the four PAHs found to vary as chrysene > naphthalene > pyrene > phenanthrene. As the other part of the investigation, the suitability of a modified Fenton based oxidation process to enhance the rate of degradation of PAHs in aquatic environment was investigated. The effect of initial concentration of H2 O2 & Fe2+ ions, pH of the solution and the presence of triton X-100, a surfactant which could bring non polar PAHs and polar Fenton reagents in close proximity to facilitate degradation reaction were examined for 3,4 and 5 member ring compounds: phenanthrene, pyrene and benzo(a)pyrene found in local aquatic environments. Pseudo first order rate constants for degradations of all three PAHs found to increase with increasing initial H2 O2 concentrations and initial Fe2+ concentration in aqueous media. High degradation rates were observed for concentration ratios, [H2 O2 ]:[Fe2+] in the range of ~50 to ~100. Decrease of pH of solutions, also increased the rates of degradation of all three PAHs. Presence of Triton X-100 at low levels, (1% v/v in the solution) found to increase the degradation rates of all three PAHs. Under all conditions studied, the pseudo first order rate constants for degradation of Benzo(a)pyrene were found to be the largest among the three PAHs .
A Metric Represents a Sphere of Constant Density Comprising Electrically counterpoised Dust (ECD)
(Proceedings of the Annual Research Symposium 2005-Faculty of Graduate Studies, University of Kelaniya, 2005) Wickramasuriya, S B P; Wimaladharma, N A S N
The metric which represents a sphere of electrically counterpoised dust (ECD) with constant density π ρ 4 1 = is ( ) ( ) ( ) ( ) ( )  ( ) + Ω < < ∞      − +       + = = − + Ω ≤ ≤ dR R d a R R B A R B A dt ds R dR R d R a R dt ds 2 2 2 2 2 2 2 2 2 2 2 2 2 2 θ 0 θ where θ(R) is the Emden function satisfying the Emden equation with n=3, a is the coordinate radius, R is the radial coordinate , A and B are constants given by ( ) ( ) B a ( ) a A a a a θ θ θ = − = + 2 a is a constant whose value is restricted, 0 < a < b
A preliminary investigation on proteins produced by iron resistant and iron sensitive rice varieties
(Proceedings of the Annual Research Symposium 2005-Faculty of Graduate Studies, University of Kelaniya, 2005) Attanayake, K.P.R.N.; Sirisena, D.M.
K.P.R.N. Attanayake and D.M. Sirisena
A Study on Recent Political Efforts to Solve the Ethnic Conflict of Sri Lanka
(Proceedings of the Annual Research Symposium 2005-Faculty of Graduate Studies, University of Kelaniya, 2005) Bandara, H.G.D.S.V.
The ethnic conflict has taken a special place among the challenges faced by Sri Lanka at present. Since independence, almost every government took various strategic steps to solve the ethnic conflict in this country. However none of these efforts were strong enough in solving the conflict. In this study special attention has been paid to political efforts, which were taken in recent times i.e. from 1983 to 1993, to solve the ethnic conflict in Sri Lanka. The base for this study is the transformation of the ethnic conflict into an internal war as a consequence of the internal incidents, which occurred in 1983. Also taken into consideration is the international community’s attention in this regard and the opportunities gained by India to act as a mediator in solving the ethnic conflict in Sri Lanka. Apart from these, factors such as an approach that is different from previous efforts in solving the ethnic conflict can be identified the change of political power of the country in 1994 has bee taken into consideration and special attention has been paid to the decade from 1983 to 1993. The aims of this study were to study the political efforts, which were taken from 1983 to 1993 to solve the ethic conflict and to examine the factors, which made those efforts unsuccessful. Also intended is to form a pre-assumption on the base on which a future solution should be built up. This study is primarily based on secondary sources. Attention was paid to various standpoints borne by various groups on the political efforts taken to solve the ethnic problem when analyzing the research question. There were various reasons behind the unsuccessful results of the political efforts taken from 1983 to 1993. A major reason for this was the shortcomings of India’s role as a mediator, in solving the ethnic conflict of Sri Lanka. Also responsible were the lack of commitment of the central government of Sri Lanka in solving this conflict and the fact that there was no stable and uniform idea regarding the solution within the government itself. Apart from these the lack of agreement among the Tamil groups regarding, which arose solutions and also the nonflexible manner of the Tamil groups, were also to had been blamed. Also responsible were the protests arisen from the Southern parts of the island regarding the solutions, the lack of awareness among the masses on the political solutions and the lack of transparency of the process of building up a solution. Not only these but also the fact that these solutions were not strong enough to solve the ethnic conflict and their various weaknesses were also responsible for the unsuccessful results of these political efforts.
An Expert System Approach to Strategic Decision Making in Cricket
(Proceedings of the Annual Research Symposium 2005-Faculty of Graduate Studies, University of Kelaniya, 2005) Liyanage, S.R.; de Silva, C.H.
Sidath R. Liyanage and Chandima H. de Silva
An Interpretation into the Ambiguous Jina-patisatariya in the Inscriptions of the middle Anuradhapura Period
(Proceedings of Annual Research Symposium, Faculty of Graduate Studies, University of Kelaniya, 2005) Manatunga, Anura
An ambiguous word, Jinapatisatariya or its variants have occurred in a series of similar inscriptions found from Buddhist monasteries in the middle Anuradhapura period, i.e circa 2nd - 5th centuries A.C. All these inscriptions have been certainly referred to a grant or grants made to Buddhist monasteries for a particular purpose, but this purpose has not been properly identified in spite of some possible interpretations on it. D.M. de Z. Wickramasinghe has interpreted this word as having the meaning of ‘repairing of dilapidated buildings’ and understood the grants as made for that purpose. Gaiger believed that it was a ritual associated with the Buddha’s ‘Pati Dhatu’, the belt or a piece of cloth belonging to the cheevara of the Lord Buddha. Paranavitana interpreted Jinapatisatariya as the ‘spreading of deer skins’ in Buddhists monasteries, which he believed as a sacred ritual performed in these monasteries. In spite of the previous interpretations, the present study shows that the meaning of the Jinapatisatariya is the performance of the Vinayakamma known as ‘ Patisãraniyakamma’ by the Buddhist Sanga in Uposathagaras in the monasteries. ‘Jina’ in this case can be a derivation of Cinna ( Cinna-Jinna-Jina) which means ‘performed’, ‘practiced’, ‘accomplished’, ‘done’ and so on. Patisaraniyakamma referred to in the Vinaya literature can be easily identified with Patisaraniya or Patisaraniyakamma in the inscriptions. This Vinayakamma was a kind of action taken against a monk who attempted to cause a damage or a loss to a householder. The guilty monk had to make presents to the Sanga before he is interrogated for his offence by the body of Sanga. This shows why such grants were needed for this performance. It may well be ceremoniously performed in the monasteries in Anuradhapura and elsewhere in ancient Sri Lanka where these inscriptions are found.
Community composition of benthic insects of the Heen Ganga tributaries in the Knuckles region
(Proceedings of the Annual Research Symposium 2005-Faculty of Graduate Studies, University of Kelaniya, 2005) Weerasinghe, W M D; Silva, E I L; Dias, R.K.S.
Heen Ganga is a major tributary of river Mahaweli which drains through the Knuckles forest region in Sri Lanka. The community composition of benthic insects in four tributaries of Heen Ganga was investigated from June to September 2004 and in April 2005. Two of the tributaries were situated closer to the human settlements and the other two were relatively less disturbed. Another tributary in Galmal Oya was selected which is located at higher altitudes and with minimum disturbances, for the comparison. Two replicate samples were taken from each site using the Surber sampler (25 cm x 25 cm metal frame) while lifting the stones and manually stirring the bottom substrate demarcated by the frame for five minutes. Larvae and adult insects in the samples were sorted and examined under a stereo – microscope at suitable magnifications and the specimens were preserved in 70% alcohol and identified to the furthest possible taxonomic levels Insects belonging to seven orders were observed in the overall collection and Diptera (larvae only, 30 %), Coleoptera (larvae & adults , 28%), Ephemeroptera (larvae only , 21%) and Trichoptera (larvae only , 18%) dominated the orders, Odonata (larvae only, 1.8%), Plecoptera (larvae only, 1.06%) and Hemiptera (larvae only, 0.23%) observed at the Heen Ganga study sites. Also, among the six families of dipterans observed chironomids apparently dominated the other families, Tipulidae, Ceratopogonidae, Simuliidae, Athericidae and Psychodidae. Members of six families of Coleopterans, Psephenidae, Elmidae, Scirtidae, Gyrinidae , Lampyridae and Hydrophilidae and six families of ephemeropterans, Baetidae, Leptophlebiidae, Ephemeridae, Ephemerilidae , Caenidae & Prosopistomatidae were also identified. Trichopterans belonging to three suborders and eleven families, namely Glossosomatidae, Hydroptilidae , Dipseudopsidae, Ecnomidae , Hydropsychidae, Goeridae ,Calamoceratidae, Lepidostomatidae, Leptoceridae, Sericostomatidae and Helicopsychidae were observed while the members of Goeridae and Glossosomatidae were apparently dominant among them. At the Galmal Oya study site, coleopterans (33%) and dipterans (30%) were dominant while the trichopteran (26%) and ephemeropterans (8%) were observed in lower proportions. In addition, Hemiptera (1.6%) Plecoptera (1.2%) and Odonata (0.33%) were also observed. The values of diversity indices for morphospecies of common five orders indicated that there was not much difference between the diversity of benthic insect community in Heen Ganga tributaries (H’= - å pi ln pi =3.3) and the Galmal Oya study site. (H’=3.6).
Dietary fibre content of some rice varieties under raw and parboiled conditions
(Proceedings of the Annual Research Symposium 2005-Faculty of Graduate Studies, University of Kelaniya, 2005) Adikari, A.C.; Wimalasena, S.
There is a growing demand on foods rich in dietary fibre due to their beneficial health effects. Rice is the staple food for over 50% of the world population including Sri Lanka. This study reports the content of total dietary fibre (TDF), insoluble dietary fibre (IDF) and soluble dietary fibre (SDF) in two varieties of raw rice (RW)(BG 300 and BG 352), and two varieties of parboiled rice (PB)(BG 300 and BG 352) under two levels of bran removal (10% and 7%) obtained from the Institute of Post Harvest Technology, Anuradhapura. IDF was calculated by subtracting the protein and ash content from the weight of the residue obtained after hydrolyzing the sample of rice with Tetramyl enzyme, pepsin enzyme solution and pancreatin solution. The SDF was determined by subtracting the protein and ash content from the residue obtained by incubating the filterate from enzyme hydrolysis with ethanol. Protein content was determined by the Kjeldhal method and the ash content by heating in a muffle furnace at 550 0 C. It was observed that percentage of TDF, SDF and IDF ranged from 56.7% - 44.7%, 16.6 - 12.5% and 40.1 - 30.1% respectively in RW while in PB the values ranged from 63.6 -45.4%, 17.3 -10.8%, 46.2 - 34.61% respectively. For raw rice the highest TDF, SDF and IDF were obtained for BG 300 (10%) while in parboiled rice the highest value was obtained for BG 352 (10%). In all samples except for BG 352 (RW) TDF, SDF and IDF increased with increase in percentage of bran . Parboiled rice had a higher TDF and IDF than raw rice. Except in BG 352 (7%) in other varieties the percentage of SDF was higher in par boiled rice than raw rice. Percentages in parenthesis refer to the percentages of bran removed from rice. Financial assistance from ADB is acknowledged.
Diversity and community composition of the ground and lower canopy foraging worker ants in the Gilimale forest
(Proceedings of the Annual Research Symposium 2005-Faculty of Graduate Studies, University of Kelaniya, 2005) Dias, R.K.S.; Perera, K A M
Ants are a very important group of insects in the forests of Sri Lanka and their microhabitats vary from ground to the canopy. Worker ants on the ground and lower canopy of two sites in the Gilimale forest were sampled by several methods in April, June and August 2004. Worker ants were sampled along a 100 m transect in each site by the baited traps (honey and canned fish), manual collection, soil and litter sieving (Time unit method) and Winkler extraction. Branch clipping, beating and, five honey baited traps hanged at a height of 15 - 20 feet were used to sample ants on three Symplocos bractealis (Wal Bombu) and three Schumacheria castaneifolia (Kekiriwara) trees in April. Fifteen honey baited traps were hung on three of the each tree species in June. In August, five traps baited with honey, canned fish, desiccated coconut, ground peanut or paddy seeds (variety BG 11)) were hung on the same trees. Pitfall traps and baits on trees were set to collect ants that forage at dusk and the night. Worker ants were identified with the assistance of Bolton (1994) and the reference collection at the Department of Zoology, University of Kelaniya. Worker ants belonging to nine subfamilies and thirty five taxa (H = Ópi logpi = 2.56), Aenictus sp. (0.26%), Aneuretus simoni Emery (2.5%), Amblyopone sp. (0.15%), Anochetus (0.1%), Aphaenogaster sp. (25%), Calyptomyrmex sp. (0.3%), Camponotus sp. (4.7%), Cataulacus sp. (0.05%), Crematogaster sp. (9.4%), Cryptopone sp. (0.26%), Dolichoderus sp. (0.56%), Hypoponera sp. (0.1%), Leptanilla sp. (0.26%), Leptomyrmex sp. (1%), Leptogenys sp. (0.7%), Lophomyrmex sp. (0.26%), Meranoplus bicolor (0.77%), Monomorium sp. (1.1%), Myrmicaria sp. (10.4%), Odontomachus simillimus Smith (0.15%), Oligomyrmex sp. (13.4%), Paratrechina sp. (2.%), Pheidole sp. (4.5%), Pheidologeton sp. (8.4%), Polyrhachis sp. (1.2%), Ponera sp. (0.36%), Solenopsis sp. 1 (0.26%), Strumigenys sp. (0.05%), Tapinoma melanocephalum Forel (0.3%), Tapinoma indicum Forel (0.2%), Technomyrmex albipes Emery (2%), Technomyrmex bicolor Emery (2%), Tetramorium sp.1 (4.3%), Tetramorium bicarinatum Mayr (3.2%) and Tetraponera allaborans (0.05%) were recorded from the ground samples. Ten taxa (H = 1.73) of worker ants that belonging to Dolichoderinae, Formicinae and Myrmicinae, Aphaenogaster sp. (8%), Camponotus sp. (17%), Cataulacus sp. (1%), Crematogaster sp. (5%), Leptomyrmex sp. (1%), Myrmicaria sp. (1%), Polyrhachis sp. (8%), Solenopsis sp. 2 (12%), Technomyrmex albipes Emery (43%) and Tetramorium sp. 2 (4%) were identified from the lower canopy. Solenopsis sp. 2 and Tetramorium sp. 2 were observed only on the trees. Worker ants belonging to five subfamilies and fifteen morphospecies were observed in the night traps. Species Richness values recorded from both ground and the canopy in April, June and August were not significantly different (Chi-square, p > 0.05) and reached 24, 25 and 24, respectively. Presence or absence of some taxa and the proportional abundance of dominant taxa varied on the three occasions. Leptomyrmex sp. forages on the ground as well as on trees and is a new record from Sri Lanka.
Effect of application of three phosphate fertilizer sources on long term availability of different phosphorus fractions in lateritic soils in the intermediate zone of sri lanka
(Proceedings of the Annual Research Symposium 2005-Faculty of Graduate Studies, University of Kelaniya, 2005) Duminda, D.M.S.; Pathiratne, K.A.S.; Somasiri, L.L.W.
The application of three different phosphorous (P) fertilizer sources, viz., Eppawela rock phosphate (ERP), Imported rock phosphate (IRP) and Triple super phosphate (TSP) on the long term availability of several different P fractions in Lateritic soils in the intermediate zone of Sri Lanka was investigated. Each P fertilizer was treated at three different levels: 25, 50 and 100 g / palm/ 6 months in triplicate over a period of 11 years to all 6 coconut trees grown in each of the 30 experimental plots. Three experimental plots with 6 coconut trees in each with no fertilizer application were used as controls. After 11 years of fertilizer applications, soils were sampled 90 cm away from the base of coconut palm at 2 depths; (0-25) cm and (25-50) cm from randomly selected three plants from each of the plot. Soils of each treatment, sampled in triplicate, for each of the two depths were composited separately. Different P fractions, viz., saloid bound P ( Sa-P), aluminum bound P (Al-P), iron bound P (Fe-P), occluded P (Occ-P) and calcium bound P (Ca-P) were determined in each composited soil. The results showed that, in the soil depth of (0-25) cm, the ability of different fertilizers in producing plant available P; Sa-P and Al-P vary in the order of TSP>> IRP>ERP. Further, it was found that, the availability of Sa-P and Al-P in the TSP treated soil increased with increasing level of TSP application to the soil. The concentration of different P fractions in the TSP treated were in the order of Sa-P>Al-P>Occ-P>Fe-P>Ca-P. The increasing level of IRP and ERP applications did not increase the Sa-P and Al-P concentrations in the soil. The trend of the availability of different P fractions in the soil depth of (25-50 cm) was the same for all three of fertilizer sources at all three levels applications. However, the concentrations of soil P fractions found in this depth was smaller than the amounts found in the (0-25) cm depth.
An Empirical Study of the Relationship between Organizational Stress and Emotional Intelligence on Organizational Commitment: With Reference to Bank Branch Managers in the Western Province of Sri Lanka
(University of Kelaniya, 2005) Jayaweera, A.T.
Bank managers are a profession, which is of immense importance to the nation’s economic growth and prosperity. The contribution of banking organizations towards the progress of a country is vital. As a matter of fact, the contribution of banking organizations heavily depends on commitment made by bank managers towards 1achieving organizational goals. This empirical study attempts to establish a relationship of organizational stress and emotional Intelligence on Organizational Commitment of bank managers in the Western province of Sri Lanka. A conceptual model was formulated for the relationship of organizational stress, Emotional Intelligence (Independent variables) with Organizational Commitment (Dependent variable). The study was conducted among the sample of 150 managers randomly selected from fifteen public sector bank branch premises and fifteen private sector bank branch premises operating in the Western province of Sri Lanka. Data were collected through a structured questionnaire and were analyzed using the software SPSS version 10.0. The results of the correlation analysis indicated that Organizational Stress was negatively and significantly correlated with Organizational Commitment. Emotional Intelligence was positively and significantly correlated with Organizational Commitment. The results of the multiple regression analysis revealed that Organizational Stress and Emotional Intelligence are the strong predictors of the Organizational Commitment. On the whole, two independent variables were accounted for 55.9% of the variance in the organizational commitment of bank managers. Organizational Stress and Emotional Intelligence were found to be the critical factors to be focused for improving the organizational commitment of bank branch managers in the Western province of Sri Lanka.
Employability of Human Resource Management (HRM) Graduates in Sri Lanka
(University of Kelaniya, 2005) Senaratne, C.
This study examined the impact of three factors namely skills, personality, and influences on the employability of HRM graduates passed out from the Sri Lankan state universities. Data was collected from the HRM graduates passed out from the University of Kelaniya and the University of Sri Jayewardenepura, which are the premier universities in producing HRM graduates in Sri Lanka. And the data collection was based on a structured questionnaire supplemented by interviews and the study was conducted among 116 graduates. The selected sample was categorized into two groups: employed and unemployed HRM graduates. A conceptual model was formulated for the study. Employability (Dependent variable0 was measured on nominal scale and skills, Personality, and Influences (Independent Variables) were measured on ordinal scales. The ordinal data was converted into nominal data for finding out the relationship between dependent and independent variables. On-parametric statistics such as Chisquare test and Mann-Whitney test were used to analyze the data in order to identify the difference in skills, personality, and influence levels of both employed and unemployed graduates. Findings suggest that there is no significant difference in terms of Skills and Personality among the employed and unemployed graduates of HRM in Sri Lanka.The influence level found to be significantly different among the unemployed and unemployed graduates. Employed graduates used high level of influence and unemployed graduates used moderate level of influence. The results of the study indicate that HRM graduates have obtained employments largely on the base of influences made through various sources like family, school, university, political activities, and memberships of associations.
Identification and characterization of dieback syndrome in Camelliasinensis (TRI 2025)
(University of Kelaniya, 2005) Ranasinghe, C.P.; Balasuriya, A.; Jayaratne, D.L.
The disease has been reported in the tea cultivar TRI 2025, grown in the upcountry since 1989 (Nethaniel, 1999). Preliminary observations from different locations where the disease has already been reported showed pathological affiliations instead of a physiological disorder or agronomical reasons. During the eight months under investigation in the Nuwara Eliya Estate, the affected area expandedby 129.75 m2. A distinctive increase in the rate of spread was observed during dry seasons. Asignificant relationship between the spread of the disease and climatic stress was found. The rate ofspread of the disease was higher with low relative humidity and rainfall. The expansion of the patch followed the direction of the wind with an indication of an airborne disease. Phylloplane microflora of TRI 2025 between healthy and diseased plants, the soils, which they are grown, collected from diseased and healthy areas found to have no significant difference. However, Pantoea agglomerans (Beijerinck) (Gavini et al., 1989), a Gram negative rod was solely and repeatedly isolated on nutrient agar, from the xylem sap of diseased plants. The sap of visually healthy plants, of the same cultivar upon prolonged incubation developed few colonies of the same bacterium. The bacterium was also isolated from dew collected from leaves of the diseased plants. The isolate was confirmed by the International Mycological Institute (IMI) in the United Kingdom (Offord, 2003). Four experimental sets of plants used to demonstrate Koch’s postulates, using mature tea bushes (Nuwara Eliya and St. Coomb’s), young plants and tomato seedlings. None of the sets met with conclusive results. Stem section analysis of the cultivar showed a significant xylem blocking in diseased plants, which increased in numbers with the severity of symptoms. P. agglomerans (Beijerinck) (Gavini et al., 1989), produce high-molecular-weight extra-cellular polysaccharides (Balows et al., 1992) and some strains are ice-nucleae active causing frost damage (Pajand,2005). Under the evidences the dieback in TRI 2025 can be classified as a stress driven relationship between a stressed plant and an opportunist.
If therapeutic formalin treatment for gill fluke infestation is to be successful in goldfish, gill lamellae should not have reached the stage of telangiectasis
(Proceedings of the Annual Research Symposium 2005-Faculty of Graduate Studies, University of Kelaniya, 2005) Hettiarachchi, M.
Dactylogyrus sp. (a monogenean gill fluke) is one of the most common disease causing agent found in gills of goldfish, Carassius auratus reared in mud ponds. Several aquaria owners have reported that when the goldfish, infested with gill flukes were treated with the recommended therapeutic dosage of formalin (200 mgl-1 for 15 to 30 minutes), mortality of fish increased drastically; therefore, the present study was carried out to find out the possible reason for poor results of the treatment. Three slightly different stages of severity in breathing difficulty of gill fluke infested goldfish (5.5±1.5 cm SL) were identified using the behaviour exhibited by the fish. These three stages were confirmed with wet mounts under the microscope by the presence of gills covered with thick mucus (stage I) and the gills with different degree of hyperplasia (stage II) and gills under telangiectasis (dilation of groups of small blood vessels in the secondary lamellae; stage III). The fish in each different stage of breathing difficulty/gross appearance of gills were treated separately (3 replicates from each stage) with the recommended dosage of formalin; apparently healthy fish reared in cement tank were used as control and were subjected to the same treatment. During the treatment period each fish that reached the terminal stage of life was euthansiated and wet mounts of gills were observed under the microscope. Ninety eight percent of goldfish that reached the terminal stage of fish during the treatment had gill lamellae under telangiectasis before the treatment. Fish that had gills with thick mucus and hyperplasia of gill lamellae before the treatment could tolerate the treatment. It seems that the therapeutic dosage of formalin recommended for killing monogenean gill flukes is also toxic for fish if the gill lamellae have reached the stage of telangiectasis due to the presence of the parasite. Therefore it is essential to identify gill fluke infestations at an early stage, if the therapeutic treatment with formalin is to be successful in protecting goldfish while controlling the flukes.
INDIGENOUS AND EXOGENOUS FACTORS INFLUENCING IMPORT DEMAND
(Proceedings of the Annual Research Symposium 2005-Faculty of Graduate Studies, University of Kelaniya, 2005) Bandara, R.A.S.P.
Import demand of Sri Lanka will be determined by number of factors closely related to the international trade, international market, household income and price level of the imports etc. The problem of this study is to study how internal and external factors influence in determining the import demand of Sri Lanka. Import demand function that is based on the small country assumption was tested with the help of multiply regression analysis, with the objectives of identifying the influence of domestic income and price competitiveness and quantifying the factors affecting import demand, The model showed factors affecting the demand for imports and it also considers the influence of domestic income and price competitiveness. The price competitiveness variable showed the response of imports to changes in relative prices. The coefficient of relative price variable implied a negative relation ship showing that when the relative price of imported goods rises, there is a tendency to reallocate expenditure towards domestic goods. Test results show that there is a positive relationship between real income and import demand, as higher real income increases the capacity to import. Import price adjusted to the GDP deflator has negative relationship with Import Demand. Third variable of the model, net foreign assets had a positive impact on import demand. For the test, net foreign assets were divided by import price to identify the import capacity. The fourth variable, domestic credit shows negative relationship on import demand though it could have positive relationship according to the theory
Induction of pollutant responsive biomarkers, ethoxyresorufin–Odeethylase, glutathione S-transferase and biliary fluorescent aromatic compounds in tilapia inhabiting Bolgoda North Lake, Sri Lanka.
(Proceedings of the Annual Research Symposium 2005-Faculty of Graduate Studies, University of Kelaniya, 2005) Chandrasekera, L.W.H.U.; Pathiratne, A.; Pathiratne, K.A.S.
The presence of organic contaminants in aquatic systems poses a serious threat to environmental health. Biomarkers are sub-lethal biological measures of the response to and effect of pollutants in living organisms. Use of biomarkers has been identified as a powerful and cost-effective approach to obtain information on the state of the environment and the effect of pollutants on living biological resources. This study presents results of a part of the research project which focuses on evaluation of the use of biomarkers in food fish tilapia as tools in monitoring pollution in inland waterbodies in Sri Lanka. In the present study, activities of two enzyme biomarkers, ethoxyresorufin-O-deethylase (EROD) & glutathione S-transferase (GST) and biliary fluorescent aromatic compounds (FACs) in Nile tilapia (Oreochromis niloticus) collected from Bolgoda North Lake were evaluated in comparison to the baseline levels of the control fish in order to assess the biomarker responses in this fish. The results revealed that EROD and GST activities of tilapia inhabiting Bolgoda North Lake were significantly elevated several folds in comparison to the baseline levels. Liver somatic index and microsomal and cytosolic protein levels in the gill and liver tissues of fish collected from the lake were also elevated significantly compared to the controls. Induction of EROD and GST enzymes indicate the exposure of fish residing in the lake to organic contaminants such as polycyclic aromatic hydrocarbons (PAH) and polychlorinated biphenyls (PCB). Analysis of biliary FACs in the fish showed recent uptake of naphthalene, pyrene and benzo(a)pyrene type PAHs. Occurrence of PAHs in the colloids and sediments of Bolgoda North Lake has been confirmed by chemical analysis. Results suggest that EROD and GST in liver and gill tissues and FACs in bile in this fish are promising biomarkers of organic contaminations especially PAHs in the aquatic environments.
Is systemic Vibriosis a predisposing factor for white spot disease in shrimp, Penaeus monodon in grow-out ponds?
(Proceedings of the Annual Research Symposium 2005-Faculty of Graduate Studies, University of Kelaniya, 2005) Hettiarachchi, M.; Hettiarachchi, D.C.
Results of preliminary observations carried out and recorded by some grow out farm managers indicated that the cultured shrimp stocks predisposed to vibriosis are easily susceptible to white spot viral disease. Therefore the present study was carried out in May, 2005 when most of the shrimp grow out ponds at Arachchikattuwa area were affected with white spot disease to see whether there is any relationship between systemic vibriosis and white spot disease. A farm with 5 earthen ponds at Arachchikattuwa area was selected and a commercially available probiotic was used to suppress the Vibrio populations in 3 ponds; other 2 ponds did not receive the probiotic . Weekly random samples of shrimp were observed from each pond and haemolymph was inoculated on TCBS agar and cephalothorax of these shrimp were preserved in Davison Afa for histological preparations. Shrimp in each pond were observed for gross clinical signs of white spot disease. Heamolymph samples obtained from the shrimp of the 2 ponds that did not receive the probiotic treatment gradually increased and reached 480 ± 73 cfu/ml of haemolymph and such shrimp had multifocal melanized and/ or non-melanized haemocytic nodules with septic centers which is the principal diagnostic feature of systemic vibriosis. The stocks of shrimp in these 2 ponds exhibited gross clinical signs of white spot disease within 10-12 days (from the date they had Vibro count of 480±73 cfu/ml of haemolymph) and emergency harvest was carried out. In contrast, haemolymph of shrimp was free of Vibrio in the ponds that received the probiotic treatment and the shrimp did not develop systemic vibriosis and farm manager could complete the normal production cycle. Results of the present study suggest that systemic vibriosis is a predisposing factor for the occurrence of white spot disease in shrimp, P.monodon in grow out ponds.
Isolation of a plasmid harbouring cellulolytic bacterial strain from decomposing rice straw
(Proceedings of the Annual Research Symposium 2005-Faculty of Graduate Studies, University of Kelaniya, 2005) Weerakoon, D M N; Sirisena, D M
Although rice straw can be utilized as an organic fertilizer most of the farmers are compelled to discard this valuable source of nutrients without any use because of its slow rate of decomposition which obstructs the subsequent operations in the field. Organisms with high cellulolytic activity can be employed to mitigate this problem by accelerating the rate of decomposition of rice straw. Although both fungi and bacteria are capable of synthesizing cellulase enzymes, less work on such bacteria has been reported compared to that of fungi. In this study six cellulolytic bacterial strains associated with partially decomposed rice straw were isolated, identified and their cellulolytic activity was compared. Two isolates identified as Pseudomonas sp. and Acinetobacter sp. showed high level of endo-1,4-ß glucanase (carboxymethylcellulase) activity. Amount of glucose released by saccharification of cellulose was also high with these two strains. The susceptibility of these two strains to antimicrobial agents was tested with various antibiotics at different concentrations. The Acinetobacter sp tolerates high level of ampicillin i.e.100 µg /ml and Pseudomonas sp was susceptible to all tested antibiotics. The strain with antibiotic resistance, presumed to carry plasmids was examined for the presence of plasmid by plasmid DNA isolation and subsequent gel electrophoresis. This Acinetobacter sp carries a plasmid that generate eight (8) fragments when digested with Hind III .The plasmid DNA digested with Pst I produces a smear on the gel suggesting the presence of many Pst I sites. There is a dearth of information on presence of plasmids in cellulolytic bacteria. The Acinetobacter strain isolated in this study is useful to investigate whether the cellulolytic function is encoded by a plasmid gene.
Labour Market Distortions in Sri Lanka: Have they reduced under liberalised economic policies?
(University of Kelaniya, 2005) Patabendige, A.J.
Studies such as Gupta (1989), Agarwala I 1983), and Little (1982), highlight that capital-Iabour ratios (technologies) are in fact sensitive to the relative cost of labour and capital. In this background, if the factor markets are distorted in favour of selecting capital intensive technologies, labour demand or the growth of employment is impeded. Agarwala’s (1983) study on ‘Price Distortion and Growth’ of 31 developing countries confirmed that as in the case of most of the developing countries Sri Lanka’s labour market was also highly distorted during the controlled era of the 1960s and the1970. Thus, those who highly emphasise labour market distortions promote exceedingly the case for economic reforms and labour market deregulation for developing countries to enhance their labour market ‘flexibility’ to bring about a positive effect on economic growth and speeding up of employment creation. Hence, in a background of implementing economic reforms with some changes in labour practices for more than two decades from 1 977 i n Sri Lanka, it requires to determine how far the cost of labour market distortions has decreased during the economic reform period. However, a debate over the cost of labour market distortions even after the economic reforms has emerged. Some are of the opinion that although the economy moved towards a free market following the 1977 economic policy changes the Sri Lankan labour market has not been reformed to be matched with the requirements of the open economy and remained distorted, imposing a higher labour cost to investors while others believe that Sri Lankan labour is more cheaper than most of the countries in the region. Meanwhile, starting from 2002, four key Acts on labour regulations such as the Factory Ordinance of 1942 (FO), the Termination of Employment of Workmen Act of 1971 (TEWA), The Industrial Dispute Act (IDA) of 1950 were amended with a view to increasing the labour market flexibility. In this setting, this paper aims at assessing how far Sri Lanka’s labour market distortions have reduced under the reform period mainly by comparing the Sri Lankan labour market regulations and behaviour with those of the neighbouring and some of the fast developing East Asian countries depending on the data availability for the period after 1977. This comparison is made on 1) minimum wage levels, 2) employment security legislations, 3) holidays and leave, 4) maternity benefits, and 5) industrial relations.Evidence gathered shows that contrary to the conventional wisdom the minimum wage regulations in Sri Lanka do not have a large positive impact on increasing employers’ costs of labour. But quite the opposite impact on the costs of labour could be seen arising from the regulations related to the employment security, contributions to social security programmes, and the private sector and the public sector holiday and leave. These regulations have a consider ably high positive effect on increasing employers’ non-wage labour costs in Sri Lanka. Also, 13 new major labour regulations relating to various aspects of working life have been enacted after 1977 and the cost of social security has increased during the reform period. Moreover, it has been found that more than anything else the highly deteriorated industrial relations system has damaged labour market flexibility in Sri Lanka and thereby imposed a huge cost to employers without showing any improvement of labour relations from the controlled era to be consistent with open economic policy regime. Consequently, the paper concludes that more than the other countries in the region the costs of labour market distortions in Sri Lanka have significantly increased during the reform period after 19771 resulting in a considerable retardation in the labour market demand .