ARS - 2005

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Proof for an Algorithm to Solve the Lane-Emden Equation of index m, (m?N)
(Proceedings of the Annual Research Symposium 2005-Faculty of Graduate Studies, University of Kelaniya, 2005) Dharmawardane, P.M.N.; Piyadasa, R A D; Wickramasuriya, S B P
The solution of the Lane-Emden equation is very important to understand the interior stellar structure, and is of great importance in Mathematics since the equation of index grater than one represents one class of non-linear differential equations. The complete solution of the differential equation can be expressed as an infinite Taylor series of even powers under the boundary conditions to be imposed at the center of the star. Department of Mathematics of University of Kelaniya has found an algorithm [I] which can be used to obtain successive coefficients of the Taylor series and in this paper the proof of this algorithm will be given. The Lane – Emden equation of index m [II] has the following form. 0 2 2 2 + + = m y dx dy dx x d y (1) where m is a parameter. The boundary conditions are y(0) = 1, 0 1 )0( = = x dx dy y = 0. Lane- Emden equation is unchanged when –x is substituted for x, the Taylor’s expansion contains only even powers of x and the derivatives of odd order evaluated at x = 0 are all zero. ∑ ∞ =0 ! )0( n n n n y x = + + + + ... = 6! )0( 4! )0( 2! )0( )0( 6 6 4 4 2 2 y x y x y x y ∑ ∞ =0 2 2 2( )! )0( n n n n y x 71 By using Leibniz’s formula, and the boundary conditions of (1) we can obtain the following recurrence relation ( )n m n y n n y       + + + = − 3 1 2 Here n n n dx d y y = (0) and ( ) ).0( ( ) n n m n m dx d y y = Taylor’s expansion ∑ ∞ =0 ! )0( n n n n y x about x = 0 will produce the solution. But computational difficulties arise in evaluating (y m )n . Therefore we use the following algorithm. ( ) r r s s s r r m n m N(S ,S , ,S )y y y S !S ! S ! n! y C ... ... ... 1 2 1 2 1 2 = ∑ , where ( , ,........., ) N S1 S2 Sr is the number of possible arrangements of S S Sr , ,..., 1 2 such that 1 2 1 1 S + S + ...+ Sr = n , Sr ≥ Sr− ≥ ... ≥ S . The summation is over all the distinct partitions of n. The proof of this algorithm is presented in this paper. The Proof of the Algorithm It can be shown that 0 yn )0( = for odd n. Now ( ) r n r s s s m y C(S , S ,..., S ) y y ...y 2 ∑ 1 2 1 2 = Here ( , ,..., ) C S1 S2 Sr is the coefficient of r s s s y y ...y 1 2 . If ( ) n ( ) ( ) ( ) m n m y y y y 2 1 2 2 = ( ... ) is labeling each y in y m and y DD D y D y r r S s = ( ... ) = Now consider the term 1 2 . .... r S S S y y y in ( ) n m y 2 . ( ) ( ( ) ) 1 1 S 1 S y = y can be obtained in 1 2 S nC ways ( ) ( ( ) ) 2 2 S 2 S y = y can be obtained in 2 2 1 S n S C − ways . . . 72 ( ) ( ( ) ) r r S r S y = y can be obtained in r r S n S S S 1 2 1C 2 ... − − − − − ways. Therefore 1 2 . ... r S S S y y y reduces to ( ) ! !... ! 2 ! S1 S2 Sr n According to the term 1 2 . ... r S S S y y y [= ( ) ( ) ( ) r S S r S ( y ) ( y ) ...( y ) 1 2 1 2 ], S S Sr , ,..., 1 2 can be changed among themselves in N ways, where N is the number of possible arrangement of S S Sr , ,..., 1 2 and ... . Sr ≥ Sr−1 ≥ ≥ S1 Therefore r C S S S C m ( 1 , 2 ,..., r )= ( ) ! !.... ! 2 ! S1 S2 Sr n N. Hence ( ) ( ) ( , ,... ) . ! !... ! 2 ! 1 2 ... 1 2 2 S1 S2 Sr r r r m n m N S S S y y y S S S n y = ∑ C Now we replace 2n by n, to get ( ) S S Sr r r r m n m N S S S y y y S S S n y C 1 2 ... 1 2 1 2 ( , ,... ) ! !... ! ! = ∑ , where 1 2 . , ,..., r S S S y y y denote , , , 2 4 6 y y y and so on, ( , ,... ) N S1 S2 Sr denotes the number of possible arrangement of S S Sr , ,..., 1 2 , S1 + S2 + ...+ Sr = n and ... . Sr ≥ Sr−1 ≥ ≥ S1 Though the proof applies to positive integers m, the solution obtained by use of the algorithm holds true for fractional values also.
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.
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
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.
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.
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).
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
'One Man's Rubbish, another Man's Treasure': the Fundamental Problems Associated with Archaeological Ceramic Analysis
(Proceedings of the Annual Research Symposium 2005-Faculty of Graduate Studies, University of Kelaniya, 2005) Gunawardhana, Prishanta
The purpose of this paper is to give an introduction into archaeological pottery analysis. This paper will begin by discussing the origins of pottery. The earliest ceramic objects found are fired clay figurines from Dolni Vestonice in Czechoslovakia, which date to 26,000 years ago (Vandiver et al 1989). It was during the early Holocene, when societies became more sedentary, that pottery began to become a common tool. The earliest pottery found in Sri Lanka is from the Proto-historic period (Bandaranayake 1992). Pottery is one of the most important artifacts to the archaeologist. It has the benefits that it is durable, found on most sites and often in large quantities. Another benefit is that pottery is easily broken, because of this it regularly features in the archaeological record, providing researchers with large quantities of information; it also means that it is frequently replaced, allowing styles to develop. This leads to the further use of pottery as a dating method. Because of the development of styles over time, we can chart as it becomes popular and then falls out of fashion, and then use this to propose a chronology. Social status can also be suggested at, based on certain indicators of wealth and their presence or absence, such as artifact types, the amount of labour required for production, and the scarcity and cost of resources used in the production(Sinopoli 1991). This paper will finish by addressing the problems associated with pottery analysis. One is the movement of artifacts, during deposition and also the movement of the sherds over time. Also there a huge backlog of unsorted pottery developing, partly due to poor practice, but also due to lack of pottery specialists, which means large quantities of data is left unutilized. Another significant problem is the lack of adequate storage facilities, whereby new pottery cannot be stored and old pottery cannot be accessed.
SOCIO - ECONOMIC EFFECTS OF THE TOURIST INDUSTRY: A case study of three selected tourist destinations in the Nagombo coastal belt
(Proceedings of the Annual Research Symposium 2005-Faculty of Graduate Studies, University of Kelaniya, 2005) Fernando, W.V.N.
Tourism in Sri Lanka, as a major source of income and employment has developed gradually since the late 1960s and has become a priority sector of the economy today. In spite of its positive effects, tourism has also some adverse social and cultural impacts. The present paper deals with such adverse social and economical impacts on the communities living in Negombo area of the Western coast, where tourism related activities are more intense. Case studies have been conducted in Palangatura, Eththukala and Kudapaduwa GN divisions of Negombo DS division and, field survey techniques such as structured interviews administrating questionnaires and field observations were conducted covering different segments of the society in the area. At the field survey there were three types of questionnaires administrated on different respondent that is Householders, Hotels and Shopkeepers. In each case the sample size was 30. The study revealed that some social and cultural changes have taken place subsequent to the adoption of tourist related activities by the traditional fishing communities. Both direct and indirect employment opportunities have been generated in the tourist sector, leading to multiplier effects in associated areas. The economy and lifestyle of the people have also undergone many parallel changes like child abuse and other illicit activities. The dropout rates of school children have also increased due to the harmful environmental impacts of commercialization. The findings of the study provide a sound basis for formulating favorable policies for developing tourism sector in the area.
Tsunami: Affected Archaeological Heritage Sites in the Western Province,Sri Lanka
(Proceedings of the Annual Research Symposium 2005-Faculty of Graduate Studies, University of Kelaniya, 2005) Gunawardhana, Prishanta; Katugampola, Mangala
Sri Lanka’s archaeological heritage goes back from the Historical period right back to the Protohistoric and Prehistoric periods (Deraniyagala, 1996, Silva, 1990). This archaeological heritage includes a variety of outstanding monuments, buildings and sites. Significantly, some of them are now declared as World Heritage sites. It is evident that Tsunami has devastated much of the coastal belt in Sri Lanka that hit and destroyed the people lives and their property. More than 30,000 people have been killed and nearly 900,000 have been made homeless. The UNESCO World heritage site of Galle was not seriously affected. However, the Maritime archaeological museum located within this environment has been subjected to some damage due to flooding in the area. It is almost certain that some of the cultural heritage sites and the cultural landscape of the costal belt has also been greatly damaged or destroyed. The damage is extensive and the sites need to be conserved within the framework of archaeological principles. This paper is intended to discuss the damage to the cultural heritage in the Colombo, Gampaha and Kalutara districts of the Western Province of Sri Lanka. We have identified twenty eight sites which have been affected by the tsunami disaster in these three districts (Gunawardhana and Katugampola, 2005). In this paper, we will also describe the scale of the damages to the archeological heritage sites in the Western Province.
Strengthening Small and Medium Sized Towns in Regional Development in Sri Lanka A Case Study of the Sabaragamuwa Province
(Proceedings of the Annual Research Symposium 2005-Faculty of Graduate Studies, University of Kelaniya, 2005) Uduporuwa, R J M
Urban-based development approach has become more popular in recent decades in manycountries as one of the most effective approaches that search solutions to the problem ofregional imbalances. In this regard, many countries have paid attention to promote a regional economy based on the economy of small and medium sized towns which have a potential for development in economically backward regions since they believe that urban growth as one of the key forces which bring innovations and socio-economic changes. In this context, the present study has made an attempt to realize the urban system and the nature of urban-rural relations of the Sabaragamuwa Province of Sri Lanka. Two towns in the Sabaragamuwa Province namely Mawanella and Rambukkana were selected for this purpose. According to the results of the study presently Sabaragamuwa Province has the lowest level of urbanization among all other provinces (except northern and eastern provinces) of Sri Lanka and is experiencing a very slow growth of the urban population as a whole. It has only 12 urban centres out of 99 Service centres. All the urban centres of the province are medium and small towns according to the national urban system and are basically administrative and service oriented towns rather than manufacturing or industrial centres. It is also found that people prefer to interact more with the medium and large towns that offer a wide range of goods and ,services rather than the small towns in terms of rural-urban relationship of the Sabaragamuwa Province. Although there are intensified economic linkages between both towns and the hinterland in obtaining lower order goods and services and selling their agricultural products, a higher percentage of people interact with the other regional capitals which are located around the selected towns in terms of obtaining higher order goods and services than the urban centres in the Sabaragamuwa Province since they offer much greater opportunities. Other linkages such as physical, technical, social and population movement also are higher in the medium sized towns. At the same time, this study revealed that these towns transfer the agricultural resources of the province to the Colombo Metropolitan Area as raw materials without contributing to the regional growth. All these factors have contributed to keep the Sabaragamuwa Province at the lowest level of urbanization among other provinces 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.
The effects of application of three different phosphate fertilizer sources on the short term availability of some phosphorus fractions in the lateritic soils of 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 present study investigates, the application of three phosphorous (P) fertilizer sources; Imported Rock Phosphate (IRP), Eppawela Rock Phosphate (ERP) and Triple Super Phosphate (TSP) on the short term availability of different P fractions in the lateritic soils in the intermediate zone of Sri Lanka. The available different P fractions in pots with and without Ruzi grass (Brachiaria ruziziensis L.) as an indicator plant was determined after six months from the date of application of the fertilizers. Each P fertilizer, was treated in triplicate at three different levels, viz., 15, 30, 60 mg P2 O5 /100g soil, separately into pots with and without Ruzi grass. The control with and without Ruzi grass was also carried out in triplicate without fertilizers. The soil moisture content in all the pots was maintained at 60% of field capacity. Phosphorus concentration and total dry matter content of grass were determined bimonthly over six month period. The soils were analyzed for the concentrations of different P fractions, viz., saloid bound P (Sa–P), aluminium bound P (Al–P), iron bound P (Fe– P), occluded P (Occ–P) and calcium bound P (Ca–P). The results revealed that, (i) Ruzi grass utilize more Sa-P and Al-P fractions than Occ-P, Fe-P and Ca-P fractions. (ii) The P uptake by Ruzi grass was low for both IRP and ERP applications compared to TSP application. (iii) Both ERP and IRP fertilizers did not show any significant increase in P uptake with increasing level of their application. Unlike ERP and IRP, the TSP applications showed a linear increase of P uptake by Ruzi grass with increasing the level of P treatment. The overall results indicated that, for short term application TSP is superior to IRP and ERP, though IRP was found to be slightly better than ERP in providing available P.
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.
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.
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 .
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.
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.
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 .